Archive for the ‘Chemical Biology and its relations to Metabolic Disease’ Category

Stomach Cancer Subtypes Methylation-based identified by Singapore-Led Team

Posted in Biological Networks, Gene Regulation and Evolution, Biomarkers & Medical Diagnostics, CANCER BIOLOGY & Innovations in Cancer Therapy, Cardiovascular Pharmacogenomics, Cell Biology, Signaling & Cell Circuits, Chemical Biology and its relations to Metabolic Disease, Chemical Genetics, Computational Biology/Systems and Bioinformatics, Genome Biology, Genomic Testing: Methodology for Diagnosis, Health Economics and Outcomes Research, Liver & Digestive Diseases Research, Molecular Genetics & Pharmaceutical, Personalized and Precision Medicine & Genomic Research, Pharmaceutical R&D Investment, Population Health Management, Genetics & Pharmaceutical, Technology Transfer: Biotech and Pharmaceutical, tagged Cancer - General, Cancer Genome Atlas, Conditions and Diseases, DNA methylation on October 17, 2012| 2 Comments »

Reporter: Aviva Lev-Ari, PhD, RN

Word Cloud By Danielle Smolyar

GASTRIC CANCER

Methylation Subtypes and Large-Scale Epigenetic Alterations in Gastric Cancer

+Author Affiliations

¹Cancer and Stem Cell Biology Program, Duke-NUS Graduate Medical School, 8 College Road, Singapore 169857, Singapore.
²NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, 5 Lower Kent Ridge Road, Singapore 119074, Singapore.
³National Cancer Centre Singapore–Van Andel Research Institute Translational Research Laboratory, Department of Medical Sciences, National Cancer Centre, 11 Hospital Drive, Singapore 169610, Singapore.
⁴Laboratory of Cancer Genetics, Van Andel Research Institute, Grand Rapids, MI 49503, USA.
⁵Cellular and Molecular Research, National Cancer Centre, Singapore 169610, Singapore.
⁶Neuroscience and Behavioural Disorders, Duke-NUS Graduate Medical School, Singapore 169857, Singapore.
⁷Singapore-MIT Alliance, National University of Singapore, Singapore 119074, Singapore.
⁸Division of Medical Oncology, National Cancer Centre, Singapore 169610, Singapore.
⁹Cancer Science Institute of Singapore, National University of Singapore, Singapore 119074, Singapore.
¹⁰National Cancer Institute Singapore, National University Hospital, Singapore 119228, Singapore.
¹¹Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC 27710, USA.
¹²Genome Institute of Singapore, 60 Biopolis Street, Genome 02-01, Singapore 138672, Singapore.

+Author Notes

↵* These authors contributed equally to this work.
↵† Present address: LabConnect, LLC, 2910 First Avenue South, Suite 200, Seattle, WA 98134, USA.

↵‡To whom correspondence should be addressed. E-mail: gmstanp@duke-nus.edu.sg

ABSTRACT

Epigenetic alterations are fundamental hallmarks of cancer genomes. We surveyed the landscape of DNA methylation alterations in gastric cancer by analyzing genome-wide CG dinucleotide (CpG) methylation profiles of 240 gastric cancers (203 tumors and 37 cell lines) and 94 matched normal gastric tissues. Cancer-specific epigenetic alterations were observed in 44% of CpGs, comprising both tumor hyper- and hypomethylation. Twenty-five percent of the methylation alterations were significantly associated with changes in tumor gene expression. Whereas most methylation-expression correlations were negative, several positively correlated methylation-expression interactions were also observed, associated with CpG sites exhibiting atypical transcription start site distances and gene body localization. Methylation clustering of the tumors revealed a CpG island methylator phenotype (CIMP) subgroup associated with widespread hypermethylation, young patient age, and adverse patient outcome in a disease stage–independent manner. CIMP cell lines displayed sensitivity to 5-aza-2′-deoxycytidine, a clinically approved demethylating drug. We also identified long-range regions of epigenetic silencing (LRESs) in CIMP tumors. Combined analysis of the methylation, gene expression, and drug treatment data suggests that certain LRESs may silence specific genes within the region, rather than all genes. Finally, we discovered regions of long-range tumor hypomethylation, associated with increased chromosomal instability. Our results provide insights into the epigenetic impact of environmental and biological agents on gastric epithelial cells, which may contribute to cancer.

http://stm.sciencemag.org/content/4/156/156ra140

Sci Transl Med 17 October 2012:
Vol. 4, Issue 156, p. 156ra140
Sci. Transl. Med. DOI: 10.1126/scitranslmed.3004504

Methylation-based Stomach Cancer Subtypes

October 17, 2012

By a GenomeWeb staff reporter

NEW YORK (GenomeWeb News) – A new study in Science Translational Medicine is highlighting the epigenetic subtypes that exist within stomach cancer.

“Our results strongly demonstrate that gastric cancer is not one disease but a conglomerate of multiple diseases, each with a different underlying biology and hallmark features,” senior author Patrick Tan, a cancer researcher with the Duke-National University of Singapore Graduate Medical School, said in a statement.

“If gastric cancer is the result of multiple interacting factors, including both environmental factors and host genetic factors, we need better ways to diagnosis and treat it,” added Tan, who is also affiliated with Singapore’s National Cancer Centre and the Genome Institute of Singapore.

Tan and colleagues based in Singapore and the US did array-based DNA methylation analyses on more than 200 gastric tumors and dozens of gastric cancer lines. Their subsequent analyses of these methylation profiles indicated that stomach cancers have many stretches of sequence with higher or lower levels of methylation compared with nearly 100 matched normal stomach samples.

Within the tumor and cell lines, the analysis revealed subsets of gastric cancer with distinct methylation profiles that appear to be prognostically important.

In particular, a group of tumors known as CIMP (CpG island methylator phenotype) tumors, which show excess methylation at some cytosine and guanine-rich regions of the genome, tended to turn up in younger gastric cancer patients and those with poor outcomes.

On the other hand, results of the study also hint that the pronounced methylation shifts in these CIMP gastric cancers could also render them more vulnerable to demethylating compounds.

“Gastric cancer is a heterogenous disease with individual patients often displaying markedly different responses to the same treatment,” Tan said. “Improving gastric cancer clinical outcomes will require molecular approaches capable of subdividing patients into biologically similar subgroups, and designing subtype-specific therapies for each group.”

Previous genomic studies have started to unravel the range of somatic mutations and other genetic alterations that can contribute to gastric adenocarcinoma, the researchers noted. Less is known about the epigenetic features of the often deadly disease, which is especially common in some Asian populations, though some studies have identified specific genes with unusual epigenetic profiles in gastric cancer.

In an effort to more fully understand the epigenetic features of stomach cancer, Tan and his colleagues used Illumina Infinium arrays to profile cytosine methylation patterns in tumor samples from 203 individuals with gastric cancer, along with matched normal stomach tissue samples for 94 of the patients.

Using a similar strategy, the group also measured genome-wide methylation patterns in 37 stomach cancer cell lines.

When they compared methylation profiles across the samples, the researchers saw that some 44 percent of the CpG sites tested had higher- or lower-than-usual cytosine methylation levels that were specific to the stomach cancer. Around a quarter of these seemed to coincide with either jumps or — more frequently — dips in gene expression in the tumors, they reported.

A subset of the tumors had especially high levels of CpG island methylation, the team found. Follow-up analyses indicated that these tumors — which comprise an apparent CIMP sub-group of the stomach cancer — were more commonly found in young patients and/or those with poor survival outcomes.

Over-represented amongst the genes in highly methylated regions of CIMP tumors were genes implicated in stem cell-related processes, researchers noted, as were sites recognized by the histone regulating Polycomb repressive complex.

“Taken collectively,” they wrote, “these results suggest that CIMP tumors may represent a clinically and biologically distinct sub-group of gastric cancers.”

Moreover, in one of its follow-up experiments the team found that it was possible to curb the proliferation of seven gastric cancer-derived cell lines in the CIMP sub-group using a demethylating drug called 5-aza-2′-deoxycytidine, or 5-Aza-dC — an effect they did not see in 10 non-CIMP cell lines treated with the drug.

Based on findings from their methylation and gene expression profiling in gastric cancer so far, the study authors argued that an improved appreciation of the methylome-based sub-types present in the disease might aid future efforts to improve stomach cancer diagnosis and treatment options.

“[A]dditional work will focus on developing simple diagnostic tests to detect gastric cancer at earlier stages, plus drugs and drug targets that might exhibit high potency against different molecular subtypes of disease,” Tan said in a statement.

Personalized Pancreatic Cancer Treatment Option

Posted in CANCER BIOLOGY & Innovations in Cancer Therapy, Cell Biology, Signaling & Cell Circuits, Chemical Biology and its relations to Metabolic Disease, Chemical Genetics, Disease Biology, Small Molecules in Development of Therapeutic Drugs, Genome Biology, Genomic Testing: Methodology for Diagnosis, Glycobiology: Biopharmaceutical Production, Pharmacodynamics and Pharmacokinetics, Human Immune System in Health and in Disease, Imaging-based Cancer Patient Management, Liver & Digestive Diseases Research, Medical and Population Genetics, Molecular Genetics & Pharmaceutical, Personalized and Precision Medicine & Genomic Research, Pharmaceutical Industry Competitive Intelligence, Pharmaceutical R&D Investment, Population Health Management, Genetics & Pharmaceutical, Reproductive Andrology, Embryology, Genomic Endocrinology, Preimplantation Genetic Diagnosis and Reproductive Genomics, Technology Transfer: Biotech and Pharmaceutical, tagged Cancer - General, Chemotherapy, Clinical trial, Gemcitabine, gene expression, Pancreatic cancer, tumor on October 16, 2012| 6 Comments »

Personalized Pancreatic Cancer Treatment Option

Reporter: Aviva Lev-Ari, PhD, RN

Clovis on Track to Unveil Data on New Personalized Pancreatic Cancer Treatment Option by Year End

October 10, 2012

By Turna Ray

Drug developer Clovis Oncology is planning to report data from a clinical trial later this year that may yield a new treatment option for pancreatic cancer patients who are poor responders to gemcitabine.

Clovis is conducting a study, called LEAP, of 360 chemotherapy-naïve metastatic pancreatic cancer patients who are randomized to receive the current standard of care gemcitabine, or the investigational CO-101, a gemcitabine-lipid conjugate. The study investigators are hypothesizing that unlike gemcitabine, CO-101 won’t depend on the expression levels of the protein cellular transporter hENT1 to enter and destroy tumor cells.

Gemcitabine, currently the first-line standard chemotherapy treatment for metastatic pancreatic cancer patients, requires a transport mechanism to help it enter tumor cells. Previously published data suggest that patients with high hENT1 expression respond well to gemcitabine, while those with low expression — about two-thirds of pancreatic cancer patients — respond poorly to the chemotherapeutic.

LEAP researchers have prospectively collected biopsy samples and have enrolled both high- and low-hENT1 expressers. Study investigators will be blind to the hENT1 expression status of patients until the end of the trial. Clovis is working with Roche subsidiary Ventana Medical Systems to simultaneously develop and validate a companion diagnostic that can gauge low and high hENT1 expression. The primary outcome that study investigators are measuring in LEAP is overall survival in the hENT1-low population.

“The question really is whether the lipid, which facilitates entry into the cell through passive diffusion, is going to be able to deliver gemcitabine as efficiently as when a nucleoside transporter is present,” Clovis CEO Patrick Mahaffy told PGx Reporter. “The answer is we don’t know, but we’ll find out in the study.”

The study may reveal that since CO-101 doesn’t depend on hENT1 to enter tumor cells, all metastatic pancreatic cancer patients, regardless of low or high expression of this protein, derive a level of benefit from the new treatment. Still, Clovis is using a companion test to stratify patients after factoring in reimbursement and cost-effectiveness considerations, which currently are perhaps the biggest barriers to the adoption of personalized treatments.

“Nothing we know suggests that we would be better than gemcitabine … in the hENT1 high population. Given the evolving reimbursement environment and the fact that gemcitabine is generic and is priced as such, pending a successful outcome we anticipate that [CO-101] would be used primarily, if not solely, in the hENT1 low population where we anticipate poor outcomes for gemcitabine,” Mahaffy said. “We anticipate that gemcitabine would continue to be the favored product on price alone even if we were to show equivalence to CO-101 in the hENT1 high population.”

Clovis Oncology will commercialize CO-101 globally. The company is currently setting up commercialization infrastructure in the US for the drug, anticipating a launch as early as next year. Clovis won’t necessarily co-promote CO-101 and the companion test with Ventana. The test developer will be in charge of commercializing the test, and Clovis will market the drug with its sales representatives, who will also be educating oncologists about the need for a companion test.

Ventana will submit its premarket approval application for the hENT1 expression test at the same time that Clovis submits its new drug application for CO-101. The test will be marketed as not just a companion diagnostic to assess whether pancreatic cancer patients have low levels of hENT1 and would therefore respond to CO-101, but Ventana will also be able to market the diagnostic as a tool to determine which high-hENT1 expressing patients should be given gemcitabine.

“The [LEAP] trial will clinically validate the diagnostic both for determining response to both gemcitabine and CO-101,” Mahaffy said.

There are around 120,000 cases of pancreatic cancer each year in the US, EU, and Japan, and around 24 percent of patients survive for one year. Around 80 percent of pancreatic cancer patients receive gemcitabine as monotherapy or in combination with other cytotoxic agents. Based on the low incidence of metastatic pancreatic cancer, Clovis has garnered Orphan Drug status for CO-101 from US and European regulatory authorities.

Although a number of retrospective trials have demonstrated that hENT1 expression levels impact outcomes in pancreatic cancer patients in the metastatic and adjuvant setting, LEAP will be the first prospective validation of this observation. “That’s why this trial is so important to the pancreatic cancer community,” Mahaffy said. “Because not only are we going to learn about CO-101, but we’re going to learn prospectively about the role hENT1 plays in determining the outcome for patients’ treatment with gemcitabine alone.”

Testing for hENT1 expression status is not widely conducted by doctors in the care of pancreatic patients. “In fact, it’s not even widely known in the broader community setting,” noted Mahaffy, adding that academic oncologists are increasingly aware of the association between hENT1 expression and gemcitabine efficacy. After LEAP concludes and if the trial is successful, Clovis plans to initiate discussions with treatment guideline-setting bodies.

In addition to looking at CO-101 as a first-line metastatic pancreatic cancer treatment in hENT1-low patients, Clovis is also studying the drug-conjugate as a second-line treatment in metastatic pancreatic cancer (Phase II), as well as in non-small cell lung cancer (Phase I).

Personalized NSCLC Drug

In addition to CO-101, Clovis has a number of investigational agents in its pipeline that it is developing in molecularly defined patient subsets. For example, CO-1686 is a selective covalent inhibitor of EGFR mutations that the firm is exploring in patients with NSCLC. Currently Clovis is conducting a dose-finding Phase I/II trial involving CO-1686 in NSCLC patients with T790M mutations. Patients with these “gatekeeper” mutations become resistant to treatment to widely prescribed EGFR-inhibiting NSCLC drugs, Roche/Genentech’s Tarceva and AstraZeneca’s Iressa.

CO-1686 “is a very potent inhibitor of T790M … [mutations in] which occur in 50 percent of lung cancer patients, after treatment with Tarceva,” Mahaffy said. After the dose-finding portion of the Phase I/II trial, Clovis plans to initiate an expansion cohort looking at T790M mutation-positive patients who are resistant to Tarceva. “If we see the kind of results we hope to in that expansion cohort, we would initiate a registration study beginning in 2014 in Tarceva-failed patients with T790M mutations,” he said.

While CO-1686 is an inhibitor of T790M mutations and other activating mutations of EGFR, the drug doesn’t inhibit wild-type EGFR like Tarceva and Iressa do, which can make NSCLC patients prone to serious side effects. “What is interesting about [CO-1686] is it is a very potent inhibitor of activating mutations of EGFR, the same targets that Tarceva or Iressa address, but unlike those drugs, [CO-1686] does not inhibit wild-type EGFR,” Mahaffy said. With CO-1686, “we should see very limited rash and diarrhea side effects associated with Tarceva and Iressa.”

First, Clovis will study CO-1686 as a second-line treatment in NSCLC patients with T790M mutations. Eventually, Clovis plans to study the drug head-to-head against Tarceva in the first-line setting. “Given the activity of our drug in animal models so far, we think we may have the ability to demonstrate superiority in terms of efficacy and from the side effects of Tarceva,” Mahaffy said. “We would hope to demonstrate in addition to a cleaner safety profile, a longer duration of benefit, because we would prevent that primary resistance mechanism in T790M from emerging.”

Roche Molecular Systems has partnered with Clovis to develop a companion diagnostic for CO-1686.

Meanwhile, last year, the European Commission approved the use of Roche/Genentech’s Tarceva as a first-line treatment for NSCLC in patients with EGFR mutations (PGx Reporter 9/7/2012). Last month, UK’s National Institute for Health and Clinical Excellence issued a draft guidance recommending that the country’s National Health Service pay for Tarceva as an option for this patient population. The company is in discussions with the US Food and Drug Administration about launching Tarceva in this population (PGx Reporter 06/08/2011).

Additionally, Boehringer Ingelheim is developing afatinib, a drug intended for advanced NSCLC patients with EGFR mutation-positive tumors (PGx Reporter 6/6/2012). Boehringer is working with Qiagen to advance a companion test for its drug.

An NGS-Based Companion Dx?

Another drug in Clovis’ pipeline is an inhibitor of PARP 1 and PARP 2, called rucaparib, which the company licensed from Pfizer. Rucaparib is currently undergoing Phase I/II trials in breast and ovarian cancer. The company is investigating the efficacy and safety of the drug in patients who lack the ability to repair damaged DNA that cancer cells need to thrive.

Mahaffy highlighted that Clovis is currently continuing a dose-finding Phase I study initiated by Pfizer combining rucaparib with carboplatin, and is conducting a Phase I trial investigating the drug as a monotherapy. This latter study will include an extension cohort of ovarian cancer patients with germline BRCA mutations.

Clovis is among a handful of drug developers, including Abbott and AstraZeneca, that are advancing PARP inhibitors with a personalized medicine strategy, betting that patients with BRCA 1/2 mutations will respond better to this class of drugs than those without these mutations. Previous studies have demonstrated that the PARP 1 enzyme and the BRCA gene work in concert to repair DNA damage, enabling survival of cancer tumors. Patients with BRCA mutations can’t repair DNA damage in this way, so then PARP inhibitors can be more effective in stopping cancer growth.

Abbott and AstraZeneca are using a companion test developed by Myriad Genetics to study their PARP inhibitors in BRCA-mutated patients with these diseases. Myriad markets BRACAnalysis, a test that gauges germline BRCA mutations associated with hereditary breast and ovarian cancer. However, gene alternations other than germline BRCA 1/2 mutations are linked to faulty DNA repair and PARP inhibitor response. For example, Clovis estimates that around 15 percent of women with ovarian cancer harbor germline BRCA 1/2 mutations, but another 8 percent of patients have somatic mutations in BRCA. Meanwhile, germline BRCA 1/2 mutations comprise only 5 percent of breast cancers.

When Pfizer was developing rucaparib, it was working with MDxHealth to explore methylation-specific markers associated with DNA damage repair and response to PARP inhibiters (PGx Reporter 2/2/2011). According to MDxHealth both methylation and mutation testing can characterize BRCA gene activity. The company previously estimated that BRCA methylation appears in about 40 percent to 50 percent of triple-negative breast cancer patients, and in about 10 percent to 30 percent in sporadic breast cancers.

Clovis has an open contract with MDxHealth looking at methylation profiles in breast and ovarian cancer, and will continue to explore this approach, specifically for methylated BRCA in triple-negative breast cancer. Additionally, Clovis is “considering the opportunity to look at both germline and somatic mutations of BRCA, based on a tissue-based assay,” Mahaffy said.

Beyond this, in August, Clovis and Foundation Medicine announced they are working together to investigate other genetic defects related to DNA repair deficiency.

“We went with Foundation Medicine … because it will allow us to reach a broader population,” Mahaffy said. For example, in ovarian cancer, Foundation Medicine’s next-generation sequencing platform could identify other mechanisms of DNA repair deficiencies that could potentially increase the intent-to-treat population for rucaparib from 15 percent of ovarian cancer patients with germline BRCA mutations to as much as 50 percent of the population that has somatic mutations in 28 additional genes that have been described as conferring “BRCA-ness” or as having a BRCA-like effect on DNA repair.

Clovis plans to develop a companion test for rucaparib on Foundation Medicine’s Foundation One targeted NGS platform. However, one challenge for Clovis is that the FDA hasn’t yet elucidated how it plans to regulate NGS-based tests. “Clearly, there is a seismic shift underway, and we may be one of the first to have plans to go forward on a premarket approval path with next-gen sequencing,” Mahaffy said. “But clearly the FDA and everyone else knows this tidal wave is coming.”

Clovis hopes to initiate a registration trial in the second half of next year looking at rucaparib as a maintenance therapy in ovarian cancer patients sensitive to platinum-based chemotherapy who have alterations in BRCA and deficiencies in other DNA repair genes. Foundation Medicine and Clovis have separately initiated discussions with the FDA about getting taking NGS-based tests through regulatory approval, Mahaffy said.

Turna Ray is the editor of GenomeWeb’s Pharmacogenomics Reporter. She covers pharmacogenomics, personalized medicine, and companion diagnostics. E-mail her here or follow her GenomeWeb Twitter account at @PGxReporter.

Why is Dysthymia, a chronic form of Depression, serious, requiring Medical Intervention

Posted in Biological Networks, Gene Regulation and Evolution, Biomarkers & Medical Diagnostics, Cell Biology, Signaling & Cell Circuits, Chemical Biology and its relations to Metabolic Disease, Chemical Genetics, Innovations in Neurophysiology & Neuropsychology, Pain: Etiology, Genetics & Innovations in Treatment, Population Health Management, Genetics & Pharmaceutical, Population Health Management, Nutrition and Phytochemistry, tagged depression, Dysthymia, Johns Hopkins, Major depressive disorder, Mental health, Self-esteem on October 16, 2012| Leave a Comment »

Reporter: Aviva Lev-Ari, PhD, RN

Dysthymia: Often Chronic, Always Serious

Johns Hopkins Health Alert

Dysthymia is a chronic form of depression that is characterized by the presence of a depressed mood for most of the day, for more days than not, over a period of at least two years. Dysthymia may be intermittent and interspersed with periods of feeling normal, but these periods of improvement last for no more than two months.

Dysthymia often goes unnoticed. And because of its chronic nature, the person may come to believe, “I’ve always been this way.” In addition to depressed mood, symptoms of dysthymia include two or more of the following:

poor appetite or overeating
insomnia or hypersomnia (excessive sleeping)
low energy or fatigue
low self-esteem
poor concentration or difficulty making decisions
feelings of hopelessness

It is far better to treat dysthymia than to think of it as a minor condition. Bypassing treatment places people at increased risk for subsequently developing major depression. In fact, about 10 percent of people with dysthymia also have recurrent episodes of major depression, a condition known as double depression.

What causes of dysthymia? Some medical conditions, including neurological disorders (such as multiple sclerosis and stroke), hypothyroidism, fibromyalgia and chronic fatigue syndrome, are associated with dysthymia. Investigators believe that, in these cases, developing dysthymia is not a psychological reaction to being ill but rather is a biological effect of these disorders.

There are many reasons for this connection. It may be that these medical conditions interfere with the action of neurotransmitters, or that medications (such as corticosteroids or beta-blockers) taken for a medical illness may trigger the dysthymia or that both dysthymia and the medical illness are related in some other way, reinforcing each other in a complicated manner.

Dysthymia can also follow severe psychological stress, such as losing a spouse or caring for a chronically ill loved one. Older people who have never had psychiatric disorders are particularly susceptible to developing dysthymia after significant life stresses.

Posted in Depression and Anxiety on October 16, 2012

Medical Disclaimer: This information is not intended to substitute for the advice of a physician. Click here for additional information: Johns Hopkins Health Alerts Disclaimer

http://www.johnshopkinshealthalerts.com/alerts/depression_anxiety/Dysthymia-Symptoms_6339-1.html?ET=johnshopkins:e92813:1366266a:&st=email&s=EDH_121016_001

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Mediterranean Diet is BEST for patients with established Heart Disorders

Posted in Biomarkers & Medical Diagnostics, Cardiovascular Pharmacogenomics, Chemical Biology and its relations to Metabolic Disease, Metabolomics, Nutrigenomics, Nutrition, Origins of Cardiovascular Disease, Personalized and Precision Medicine & Genomic Research, Population Health Management, Nutrition and Phytochemistry, tagged Beth Israel Deaconess Medical Center, Mediterranean, Mediterranean Diet, Monounsaturated fat, Murray Mittleman, Seven Countries Study on October 15, 2012| 1 Comment »

Reporter: Aviva Lev-Ari, PhD, RN

What’s Up with the Mediterranean Diet?

Why Heart Doctors Love It

Most of us have heard about the Mediterranean diet, which has generated interest from both the media and the medical community as the gold standard in healthy eating. But what’s all the fuss about – is this diet really worth all the attention?

The answer is yes, according toMurray Mittleman, MD, DrPH, a physician in the CardioVascular Institute at Beth Israel Deaconess Medical Center, Director of the Master’s in Public Health program at Harvard Medical School, and Director of cardiovascular epidemiological research at BIDMC.

“The Mediterranean diet is a very healthy eating style that has been shown to improve cardiovascular risk factors – even for patients with established heart disorders,” Mittleman says.

What is the Mediterranean Diet?

While most healthy diets include produce, whole grains, and fish, the Mediterranean diet and lifestyle offer subtle differences that may reduce the risk for heart disease, while making it easier to stick to healthy eating habits.

According to the American Heart Association, traditional Mediterranean diets have the following characteristics in common:

High consumption of fruits, vegetables, beans, nuts and grains
Use of olive oil rather than saturated fats like butter, lard, and cottonseed, palm and coconut oils
Low to moderate consumption of dairy, eggs, fish and poultry
Very little red meat
Wine in low-to-moderate amounts

The Diet’s “Discovery”

Originating from the culture and traditional foods found in the area bordering the Mediterranean Sea, this diet first drew the attention of the American scientist Ancel Keys, who was stationed in Italy during World War II. Keys became convinced that middle-aged American men were experiencing heart attacks due to their diets and lifestyles. After conducting studies in the U.S., he began to work with researchers overseas in the first cross-cultural comparison of males and heart attack risk in what is known as the Seven Countries Study.

Starting in 1958, the Seven Countries Study followed 11,579 men, 40 to 59 years of age, in four regions of the world (United States, Northern Europe, Southern Europe and Japan). This study found that men in Southern Europe were far less likely to experience coronary deaths than those in the U.S. and Northern Europe. The study also began to identify the eating pattern known as the Mediterranean diet and its protective benefits.

Since then, “additional research has continued to show the beneficial effects of the diet,” says Mittleman. “The Lyon Diet Heart Study, conducted in the 1990s in France, showed that those who followed the Mediterranean Diet for three years had significantly fewer additional heart attacks and a 76 percent reduction in cardiovascular deaths compared to the control group.”

How Does it Work?

Murray A. Mittleman, MD, DrPH

The Mediterranean diet is a combination of many healthy choices that work together to promote good health, according to Mittleman.

“There is a low intake of refined carbs and very little processed food, which is an important distinction that also lowers fat and salt content,” he explains. “There is more variety in fruit and vegetable consumption, and portions are smaller than those commonly found in the U.S.”

Understanding how and why the Mediterranean diet works involves looking at each of the components that make up this particular style of eating.

Healthy Fats

The Mediterranean diet does not focus on limiting total fat consumption, but it does avoid the use of saturated fats and hydrogenated oils (trans fats), which both contribute to heart disease.

Most of the fat calories in a Mediterranean diet come from “good” or monounsaturated fats, mainly from olive oil and also from nuts.

“These plant-based fats don’t raise blood cholesterol levels the way saturated fat does,” says Mittleman. “In fact, monounsaturated fats actually help reduce LDL cholesterol levels when used in place of saturated or trans fats.”

Monounsaturated fats such as olive, canola, sesame, sunflower and corn oils contain alpha-linolenic acid, a type of omega-3 fatty acid from plant sources. Omega-3 fatty acids lower triglycerides, moderate blood pressure, decrease blood clotting and improve the health of your blood vessels.

Light Protein Sources

Fish is frequently on the menu of the Mediterranean diet, and red meat is rarely served. Light in calories, fish is a beneficial substitute for meat-heavy Western cuisine, which is higher in unhealthy saturated fat. In addition, fish such as mackerel, lake trout, herring, sardines, albacore tuna and salmon are rich sources of omega-3 fatty acids.

Other plant-based protein sources, such as beans and nuts, also predominate in this style of eating. These vegetable protein sources are also light on saturated fat, helping to keep cholesterol and blood pressure in check.

Plenty of Produce

A wide variety of fruits and vegetables play an important role in the Mediterranean diet, and include fresh salads, greens sautéed in garlic and olive oil, soups, and vegetarian pasta dishes.

Fruits, such as melon, often serve as dessert, rather than the sweetened, high-fat concoctions that Western-style dining offers. Baked sweets are generally reserved for holidays or special occasions. Fresh produce provides phytonutrients that prevent and repair damage to cells and protect blood vessels. In addition, the added fiber in the diet slows the release of glucose in the blood stream, which is an important way to help prevent or control diabetes.

A Little Wine

Kenneth J. Mukamal, MD, MPH

The Mediterranean diet typically includes a small amount of wine. While red wine has antioxidant properties, the amount, frequency and style of enjoying wine is what makes this an important part of Mediterranean dining, according toDr. Kenneth J. Mukamal, an internist and cardiovascular researcher at BIDMC.

Mukamel served as lead researcher in a BIDMC study that linked the heart benefits of alcohol to the frequency of drinking. The study, which investigated 38,000 men over a 12-year period, was published in the New England Journal of Medicine in January 2003.

“The study confirmed that people who have one drink a day have the lowest rate of heart disease compared with non-drinkers or heavy drinkers,” says Mukamal. “It doesn’t seem to be the type of alcohol that matters; it’s the frequency. Individuals who drink a little bit three to-seven days a week are at lowest risk. There’s also evidence that alcohol consumed with meals — which is typical in the Mediterranean diet — is safest, providing a more gradual increase in blood alcohol levels.”

How much alcohol is appropriate? The American Heart Association recommends up to one drink a day for women and one to two drinks a day for men. Examples of one drink include 4 ounces of wine, 12 ounces of beer, or 1.5 ounces of distilled spirits (80 proof).

Mukamal cautions that for some people, such as those who have or are at risk for breast cancer or hepatitis C, regular consumption of alcohol may not be advisable.

“It’s a complex mixture of potential risks and benefits, so it’s always worth a discussion with your doctor to be sure that drinking small amounts of alcohol is right for your situation,” he says.

Taking the Mediterranean Route

The incidence of heart disease and deaths in Mediterranean countries is lower than in the United States, but such statistics may not be entirely dependent upon diet. The Mediterranean diet is part of a lifestyle in which exercise, such as walking, is frequent. Families and friends gather to enjoy meals and each other’s company. And the pace of living seems less frenetic than elsewhere.

But you don’t have to go to Rome to live as the Romans do. With some planning and attention to diet and lifestyle, you can bring the flavor and health benefits of the Mediterranean into your own life.

The changes aren’t as severe as you might think. Here are some steps that can get you moving in the right direction:

Take a half-hour walk each day.
Use olive oil instead of butter or margarine.
Increase servings of fresh veggies and fruits – aim for at least seven per day.
Eat fish and poultry and minimize or eliminate red meat.
Aim for several meatless meals each week, incorporating legumes as a protein source when possible.
Use fresh herbs and spices to flavor food instead of salt.
Avoid foods that are processed, high in fat, or contain trans or saturated fat.
Have a small glass of wine with dinner, if your doctor agrees.
Invite your family and friends to join you!

“The Mediterranean diet is very sustainable and livable,” says Mittleman. “There’s a lot of variety for your palate and it’s easy to maintain. The heart-health benefits will pay you back for a lifetime.”

Above content provided by the CardioVascular Institute at Beth Israel Deaconess Medical Center. For advice about your medical care, consult your doctor.

Posted October 2012

http://bidmc.org/CentersandDepartments/Departments/CardiovascularInstitute/CVINewsletter/MediterraneanDiet.aspx

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Factors affecting the PK of the nanocarrier

Posted in Biomarkers & Medical Diagnostics, BioSimilars, CANCER BIOLOGY & Innovations in Cancer Therapy, Chemical Biology and its relations to Metabolic Disease, Disease Biology, Small Molecules in Development of Therapeutic Drugs, Human Immune System in Health and in Disease, Nanotechnology for Drug Delivery, Pharmaceutical Industry Competitive Intelligence, Technology Transfer: Biotech and Pharmaceutical, tagged Biology, Cancer - General, carrier, Chemistry, clearance, medicine, nanoparticles, nanotechnology, polymer, research on October 9, 2012| 3 Comments »

Author: Tilda Barliya PhD

Title: Factors affecting the PK of the nanocarrier.

Category: Nanotechnology in drug delivery

A plethora of new products are emerging as potential therapeutic agents. This calls for detailed studies of their unique pharmacologic characteristics and mechanisms of action in humans. This review written by Caron WP et al (Zamboni’s group) provides a major overview of the factors that affect the pharmacokinetics (PK) and pharmacodynamics (PD) of nanoparticle carries in preclinical models and patients (1). I will use this article as the main source as it was so nicely written yet many other references are added within.

The disposition of carrier-mediated agents (CMAs) is dependent on the carrier and not on the parent drug, until the drug is released from the carrier into the system and includes encapsulated (the drug within or bound to the carrier), released (the active drug that gets released from the carrier), and sum total (encapsulated drug plus released drug).

After the drug has been released from its carrier, it is pharmacologically active and subjected to the same routes of metabolism and clearance (CL) as the non-carrier form of the drug (1,2).

In theory, the PK disposition of the drug after it is released from the carrier should be the same as after administration of the small-molecule or standard formulations. Therefore, the pharmacology and PK of CMAs are complex and call for comprehensive analytical studies to assess the disposition of encapsulated and released forms of the drug in plasma and tumor.

Interindividual variability in drug exposure, represented by area under the plasma concentration– time curve (AUC) of the encapsulated drug and several factor can potentially affect it:

Physical characteristics of the CMA (size, charge, surface modification). Figure 1
Host-associated characteristics such as gender and age as well as the host mononuclear phagocyte system (MPS), which is a collective term for the immune cells.

F3.large.jpg (1280×843)

Figure 1 here (=figure 3 in the original paper. ref 1) : Nanoparticle clearance and biocompatibility are dependent on various factors including physical characteristics of the carrier as well as physiologic parameters such as the mononuclear phagocyte system (MPS) (reticuloendothelial system (RES)) recognition and enhanced permeability and retention (EPR) effect. There are qualitative relationships between the independent variables, namely, particle size, particle zeta-potential (surface charge), and solubility, and the dependent variable, namely, biocompatibility. Biocompatibility, or extent of exposure (area under the plasma concentration–time curve), includes the route of uptake and clearance (shown in green as the EPR effect and renal and biliary clearance), cytotoxicity (shown in red, can represent either efficacy or toxicities/ adverse events in anticancer treatment), and MPS/RES recognition (shown in blue).

The effect on the immune cells is divided into two categories: (i) responses to nanoparticles that are specifically modified to stimulate the immune system (e.g., vaccine carriers) and (ii) undesirable interactions and/or side-effects.

Immune cells that participate in nanoparticle uptake are circulating monocytes, platelets, leukocytes, and dendritic cells in the bloodstream (3,4). In addition, nanoparticles can be taken up in tissues by phagocytes, e.g., by Kupffer cells in the liver, by dendritic cells in the lymph nodes, by B cells in the spleen, and by macrophages

Uptake mechanisms may occur through different pathways and can often be facilitated by the adsorption of opsonins to the nanoparticle surface

Physical characteristics:

Particle size: In one study of liposomes, particles that had a hydrodynamic diameter between 100 and 200 nm had a fourfold higher rate of uptake in tumors than particles <50 nm or >300 nm.
Surface modification: Conjugated PEG polymer onto the surface- is known to minimize opsonization and thus subsequent decreased rate of MPS uptake overall plasma exposures of drugs contained within PEGylated liposomes were six fold higher than those contained within non-PEGylated liposomes
Surface charge: Uncharged liposomes have lower CLs than either positively or negatively charged liposomes (probably due to reduced opsonization by MPS. rate of CL from blood was significantly higher for negatively charged particles than for uncharged particles

It can be summarized as for their rate of clearance from highest (left) to lowest (right) as:

positive>negative> neutral

Note: PEGylation can alter the alter this rate significantly for example,

Levchenko et al. showed that the negative charge on liposomes can be shielded with this physical alteration, leading to a significantly reduced rate of liver uptake and consequent prolongation of their presence in circulating blood (5).

Host characteristics

Age: In some cases, age-related effects on the PK of some PEGylated liposomal agents have been reported, where in younger male patients (<60) there was a higher rate of clearance of two different agents (Doxil and CDK602) compared to older patients (>60). In other words, in older age, the CL rate was lower and therefore higher AUC/dose. No relation to age was observed for female patients, in the same study.

Alterations in the PK and PD of CMAs may involve accerelated decline in immune system functioning, specifically the association between aging and the functioning of monocytes (6). In theory, there is a loss of MPS activity or function in elderly patients, and this decreases the CL of CMAs by the MPS, leading to increased drug exposures and toxicity in elderly patients. In terms of efficacy, greater age was inversely proportional to progression-free survival; however, no correlation was found between age and overall survival.

Gender: In similar study to the one presented above, female patients had overall lower CL of DOXIL, IHL-305 and CDK602 compared to male patients of the same age.

The basis for the gender-related differences in the PK and PD of CMAs is unclear. It has been hypothesized that some of the differences may be attributed to the effects of sex hormones such as testosterone and estrogen on immune cell function.

Delivery of CMAs Into Tumor

Major advances in the understanding of tumor biology have led to the discovery of targeted agents that can deliver drugs to the desired site while minimizing exposure in normal tissues, thereby minimizing the associated adverse effects. Whereas conventional drugs encounter numerous obstacles en route to their target, CMAs can take advantage of a tumor’s leaky vasculature to extravasate into tissue, via the enhanced permeability and retention effect (EPR).

Note: The extend of the EPR effect is highly debated since although passive targeting through the EPR effect has been a key concept in delivering CMAs to tumors, it does not ensure uniform delivery to all regions of tumor. Furthermore, not all tumors exhibit an EPR effect, and the permeability of vessels may not be the same across any single tumor.

Active targeting may overcome these limitations. The CMAs can be enabled to bind to specific cells in a tumor by using surface attached ligands that are capable of recognizing and binding to cells of interest.

Antibody-mediated targeting has been the method of choice, other targeting strategies using nucleic acids, carbohydrates, peptides, aptamers, vitamins, and other agents are also being evaluated.

Other major points that can affect the PK disposition

The linearity and nonlinearity of the CLs of a drug (might be associated with the dose like with S-CKD602)(7).
Drug-drug interaction (single agent vs combination)
Body composition (Body surface area, body weight)

There are a multitude of properties of CMAs that differ from those of the active small-molecule drugs they contain. These differences lead to significant variability in the PK and PD of carrier- mediated drugs. It has been shown that physical properties, the MPS, the presence of tumors in the liver, EPRs, drug–drug interactions, age, and gender all contribute in varying degrees to the PK disposition and PD end points of CMAs in patients.

Areas of research that can aid in an understanding of how these agents should be used and how we may predict their actions in patients include pharmacogenomics, cellular function (probing the MPS), more sensitive and accurate analytical PK methods, and identification of the optimal preclinical (animal and in vitro) models.

References:

1. W P Caron, G Song, P Kumar, S Rawal and W C Zamboni.Interpatient PK and PD variability of carrier-mediated anticancer agent. Clinical Pharmacology and Therapeutics 2012 91, 802-812 http://www.nature.com/clpt/journal/vaop/ncurrent/full/clpt201212a.html

2. Zamboni, W.C. Liposomal, nanoparticle, and conjugated formulations of anticancer agents. Clin. Cancer Res. 11, 8230–8234 (2005).

http://clincancerres.aacrjournals.org/content/11/23/8230.long

http://clincancerres.aacrjournals.org/content/11/23/8230.full.pdf+html

3. Dobrovolskaia, M.A., Aggarwal, P., Hall, J.B. & McNeil, S.E. Preclinical studies to understand nanoparticle interaction with the immune system and its potential effects on nanoparticle biodistribution. Mol. Pharm. 5, 487–495 (2008). http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2613572/

4. Dobrovolskaia, M.A. & McNeil, S.E. Immunological properties of engineered nanomaterials. Nat. Nanotechnol. 2, 469–478 (2007). http://www.ncbi.nlm.nih.gov/pubmed/18654343

5. Levchenko, T.S., Rammohan, R., Lukyanov, A.N., Whiteman, K.R. & Torchilin, V.P. Liposome clearance in mice: the effect of a separate and combined presence of surface charge and polymer coating. Int. J. Pharm. 240, 95–102 (2002). http://www.ncbi.nlm.nih.gov/pubmed/12062505

6. Lloberas, J. & Celada, A. Effect of aging on macrophage function. Exp. Gerontol. 37, 1325–1331 (2002). http://www.ncbi.nlm.nih.gov/pubmed/12559402

7. Zamboni, W.C. et al. Pharmacokinetic study of pegylated liposomal CKD-602 (S-CKD602) in patients with advanced malignancies. Clin. Pharmacol. Ther. 86, 519–526 (2009). http://www.nature.com/clpt/journal/v86/n5/abs/clpt2009141a.html

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NO Nutritional remedies for hypertension and atherosclerosis. It’s 12 am: do you know where your electrons are?

Posted in Cardiovascular Pharmacogenomics, Cell Biology, Signaling & Cell Circuits, Chemical Biology and its relations to Metabolic Disease, Metabolomics, Nitric Oxide in Health and Disease, Nutrigenomics, Nutrition, tagged Atherosclerosis, Citrulline, Hypertension, L-Arg, L-Cit, nitric oxide, Nitric oxide synthase, NO, NOS, Nutritional Supplements on October 7, 2012| 12 Comments »

Author and Reporter: Meg Baker, Ph.D., Registered Patent Agent

The 1998 Noble Prize for medicine was for the discovery that nitric oxide (NO) was the chemical messenger responsible for relaxing vascular tissue and thereby increasing blood flow and reducing blood pressure. Alfred Noble himself had been prescribed nitro-glycerin for heart problems over 100 years before, a compound which is metabolized to NO.

NO, a gas at room temperature, has an exceedingly short half-life in the body. Normally, NO is produced from an amino acid, L-arginine (L-Arg), a normal component of the dietary protein, and molecular oxygen (O2) by the one of the several Nitric Oxide Synthases (EC 1.14.13.39): endothelial (eNOS, NOS III), inducible (iNOS, NOS II), and neural (nNOS, NOS I). In human studies, supplementation with l-arginine improved endothelium-dependent vasodilation.

The reaction of iNOS with L-Arg to produce NO leaves another amino acid, citrulline. Excess L-Arg can also be degraded by arginase (enzyme having two isoforms, I and II) which may be coinduced with iNOS in some cell types.

Citrulline formed as a by-product of the NOS reaction can be recycled to arginine by argininosuccinate synthetase (AS) and argininosuccinate lyase (AL).

Mori (2007) http:// www.ncbi.nlm.nih.gov/ pubmed/ 17513437 found that AS and sometimes AL are coinduced with inducible NOS (iNOS) in various cells. In these cells, NO was synthesized from citrulline (via arginine) as well as from arginine, indicating operation of the citrulline-NO cycle.

Whereas, low concentrations of NO protect cells from apoptosis, excessive NO causes apoptosis. NO causes endoplasmic reticulum (ER) stress, induces a transcription factor, CAAT/enhancer binding protein (C/EBP) homologous protein (CHOP), and leads to apoptosis.

The active site of NOS is formed by a heme-containing substrate-binding cavity, where L-arginine (Arg) and O₂ are converted to L-citrulline and NO. The electrons required for reductive O₂ activation are transferred from NADPH via the NOS-bound flavins (riboflavin, Vitamin B2) FMN and FAD. All NOS isoforms are only active as homodimers.

Generation of NO occurs in two discrete O2-requiring steps, with intermediate formation of N-hydroxy-L-arginine (NHA or NOHLA). NHA formation consumes one molecule of O₂ and two electrons. Conversion of NHA to L-citrulline and NO requires another molecule of O₂ and one more electron (http://en.wikipedia.org/wiki/Nitric_oxide_synthase). The overall stoichiometry, reflecting the three electrons derived from NADPH, that pass through the flavin co-factors and are transferred one by one via the heme iron, is then:

L-arginine + 3/2 NADPH + H⁺ + 2 O₂ = citrulline + nitric oxide + 3/2 NADP⁺

Another factor affecting NOS activity is the availability of essential co-factors such as tetrahydrobiopterin (BH4) (Boeger et al. Cardiovasc Res (2003) 59 (4): 824-833 http://cardiovascres.oxfordjournals.org/content/59/4/824.full, Vasquez-Vivar J., et al . Superoxide generation by endothelial nitric oxide synthase: the influence of cofactors. Proc. Natl. Acad. Sci. USA 1998;95:9220-9225 http://www.pnas.org/content/95/16/9220.full). H₄-biopterin binds in the immediate vicinity of the heme at the dimer interface, interacting with residues from both subunits. When BH4 availability is limiting, electron transfer from NOS flavins becomes “uncoupled” from l-arginine oxidation and the ferrous-dioxygen complex formed as an intermediate in the reaction sequence, dissociates and superoxide(O2−·) is produced.

See Figure 1 in Werner et al. 2003 Exp Biol Med 228: 1291-1302.

RADICALS

The conversion of Arg to NHA and of NHA to L-citrulline and NO both depend on the presence of H₄-biopterin. In the absence of substrate or pterin, NADPH oxidation by NOS is accompanied by formation of O₂⁻ and peroxide (H₂O₂). Uncoupled eNOS is assumed to produce superoxide (O2−·) in addition to or instead of NO (·NO) which will react with itself, with NO, or with -hydroxyl, -sulfhydryl, or or side groups of proteins, lipids, or glycans. Reaction of ·NO produced by eNOS, with O2−· produced by eNOS or by other enzymes, such as NADPH and xanthine oxidases, decreases the amount of ·NO available to stimulate vascular relaxation. At the very low BH4 concentration of 100 nmol/L, recombinant human eNOS activity is fully developed. However, biopterin is formed from the pterin heterocycle also present in folic acid (Vitamin B9,
pteroyl-L-glutamate)
and which is synthesized from GTP. Human GTP cyclohydrolase I (GTPCH), is the rate-limiting enzyme in BH4 synthesis (Crabtree et al. JBC 2008, http://www.jbc.org/content/284/2/1136.full).

In addition to the NOS reaction, which generates a H₃-biopterin radical cation, a neutral H₃-biopterin radical is formed when H₄-biopterin reacts with various radicals and which can be reduced back to H₄-biopterin by ascorbate (Vitamin C). Folate species are also required to synthesize pyrimidines and purines (for DNA synthesis and repair and NADH and NADPH).

Enhancing NO Synthesis

The normal way to increase vascular nitric oxide is through vascular stress, such as exercise. As oxygen demand increases, cardiac output increases and the endothelial lining of the arteries releases nitric oxide into the blood, which, in turn, relaxes and widens the vessel wall, allowing for enhanced blood flow.

Enhancing the presence of L-Arg or the one or more of the NOS enzymes are obviously essential for NO production. However, NOS enzymes are co-valently bound to heme (heme, iron), and flavin co-factors (Vit B2), and require soluble co-factors NADPH (a dinucleotide phosphate, containing niacin, Vitamin B3), and BH4 (from Vit B9).

Foods high in Arginine and Citrulline include melons and cucumber, peanuts, salmon, and soy. Arginine is found in varying degrees (3-15% by weight) in all animal proteins. Blue-fin tuna has 1.8 g of arginine per 100 g so 2 oz. of tuna will provide about 1 g of arginine. Other sources of 1 g of L-Arg: 2.7 oz. of chicken thighs, about 4 oz. of chicken breast, 2 oz. of 75 percent lean hamburger or about 2.5 oz. of pork.

Foods rich in antioxidants and polyphenols will provide protection against free radical assault on proteins and, in particular, act to protect the NOS enzyme and cofactors. Almost all fruit and vegetables such as blueberries, cranberries, carrots, grapefruit, soybeans, apples, and spinach contain high levels of antioxidants. In addition, nuts, tea, seeds, dark chocolate, red wine, and seafood generally contain antioxidants such as resveratrol, ascorbate, and other phytochemicals. Other free radical scavengers, tocopherols (alpha-tocopherol, Vit E) work predominantly in the lipid environment such as in cell membranes, while the sulfur-containing soluble molecule, glutathione (GSH) protects the cytosolic milieu.

Supplements

Both L-Arg or L-citrulline can be purchased over the counter. Dietary L-arginine will be taken up by the intestine and transported directly to the liver by the hepatic artery as are most of the products of digestion. Much of this L-Arg will be used in metabolic steps related to the urea cycle which is co-ordinated with the kidney to rid the body of excess nitrogen and prevent ammonia concentration from building. A small amount will enter the blood stream and be used for NO synthesis.

Proargi-9 Plus® is one product being sold containing mutltigram doses of L-Arg plus L-Citrulline in combination with anti-oxidants and folate. Proargi-9 Plus® is a registered trademark and copyright of Nature’s Sunshine Products, Inc. L-arginine Plus™ is formulation with similar ingredients and stated amounts of L-Arg and L-Citrulline and is not affiliated with the makers of Proargi-9-Plus. Niteworks® is a registered trademark and copyright of Herbalife International, Inc. and is not affiliated with or a sponsor of L-arginine Plus™.

Dr. Joe Prendergast is an endocrinologist using L-Arg therapy who, over 19 years, never had to admit any of his 7200 diabetes patients to the hospital for peripheral artery disease, recommends supplemental L-Arg formulations to his patients. The combination of L-Arg with L-citrulline a longer acting NO forming product. http://www.livingwithoutdisease.com/?route=references/prendergast

Supplements of L-Arg and, in particular, in combination with L-citrulline other B-vitamins and antioxidents may be an effective way to boost vascular NO synthesis for anyone not exercising or eating a balanced diet, having a deficiency in any of the L-Arg recycling enzymes, NOS enzymes, co-factor recycling or synthetic enzymes, or other risk factor. Specific risk factors, such as inherently elevated levels of the natural NOS inhibitor ADMA (asymmetric-dimethyl-L-arginine) are beginning to be uncovered and will be the subject of another post.

Additional References

Nitric Oxide: Biology and Pathobiology, LJ Ignarro Editor, Sep 13, 2000 http://books.google.com/books?id=h5FugARr4bgC&dq=pterin+ring&source=gbs_navlinks_s

Mori, M. Regulation of nitric oxide synthesis and apoptosis by arginase and arginine recycling. J Nutr. 2007 Jun;137(6 Suppl 2):1616S-1620S. http://www.ncbi.nlm.nih.gov/pubmed/17513437

Werner, et al. Tetrahydrobiopterin and Nitric Oxide: Mechanistic and Pharmacological Aspects Exp Biol Med December 2003 vol. 228 no. 11 1291-1302 Werner et al. Exp Biol Med 2003

Davel AP, Wenceslau CF, Akamine EH, Xavier FE, Couto GK, Oliveira HT, Rossoni LV. Endothelial dysfunction in cardiovascular and endocrine-metabolic diseases: an update. Braz J Med Biol Res. 2011 Sep;44(9):920-32. Epub 2011 Aug 19. Davel et al. Braz J Med Biol Res 2011

Rainer H Boeger. Pharmacokinetic and pharmacodynamic properties of oral L-citrulline and L-arginine: impact on nitric oxide metabolism Schwedhelm E, et al. Br J Clin Pharmacol. 2008_65_51-9

Louise Ignarro, UCLA, Nobel Prize Recipient, Author “NO More Heart Disease”

John Cook, Peripheral artery disease study, Author “Cardiovascular Cure”

Other aspects of Nitric Oxide involvement in biological systems in humans are covered in the following posts on this site:

Nitric Oxide in bone metabolism July 16, 2012

Author: Aviral Vatsa PhD, MBBS

http://pharmaceuticalintelligence.com/2012/07/16/nitric-oxide-in-bone-metabolism/?goback=%2Egde_4346921_member_134751669

Nitric Oxide production in Systemic sclerosis July 25, 2012

Curator: Aviral Vatsa, PhD, MBBS

http://pharmaceuticalintelligence.com/2012/07/25/nitric-oxide-production-in-systemic-sclerosis/?goback=%2Egde_4346921_member_138370383

Nitric Oxide Signalling Pathways August 22, 2012 by

Curator/ Author: Aviral Vatsa, PhD, MBBS

http://pharmaceuticalintelligence.com/2012/08/22/nitric-oxide-signalling-pathways/?goback=%2Egde_4346921_member_151245569

Nitric Oxide: a short historic perspective August 5, 2012

Author/Curator: Aviral Vatsa PhD, MBBS

http://pharmaceuticalintelligence.com/2012/08/05/nitric-oxide-a-short-historic-perspective-7/

Nitric Oxide: Chemistry and function August 10, 2012

Curator/Author: Aviral Vatsa PhD, MBBS

http://pharmaceuticalintelligence.com/2012/08/10/nitric-oxide-chemistry-and-function/?goback=%2Egde_4346921_member_145137865

Nitric Oxide and Platelet Aggregation August 16, 2012 by

Author: Dr. Venkat S. Karra, Ph.D.

http://pharmaceuticalintelligence.com/2012/08/16/no-and-platelet-aggregation/?goback=%2Egde_4346921_member_147475405

The rationale and use of inhaled NO in Pulmonary Artery Hypertension and Right Sided Heart Failure August 20, 2012

Author: Larry Bernstein, MD

http://pharmaceuticalintelligence.com/2012/08/20/the-rationale-and-use-of-inhaled-no-in-pulmonary-artery-hypertension-and-right-sided-heart-failure/

Nitric Oxide: The Nobel Prize in Physiology or Medicine 1998 Robert F. Furchgott, Louis J. Ignarro, Ferid Murad August 16, 2012

Reporter: Aviva Lev-Ari, PhD, RN

http://pharmaceuticalintelligence.com/2012/08/16/nitric-oxide-the-nobel-prize-in-physiology-or-medicine-1998-robert-f-furchgott-louis-j-ignarro-ferid-murad/

Coronary Artery Disease – Medical Devices Solutions: From First-In-Man Stent Implantation, via Medical Ethical Dilemmas to Drug Eluting Stents August 13, 2012

Author: Aviva Lev-Ari, PhD, RN

http://pharmaceuticalintelligence.com/2012/08/13/coronary-artery-disease-medical-devices-solutions-from-first-in-man-stent-implantation-via-medical-ethical-dilemmas-to-drug-eluting-stents/

Nano-particles as Synthetic Platelets to Stop Internal Bleeding Resulting from Trauma

August 22, 2012

Reported by: Dr. V. S. Karra, Ph.D.

http://pharmaceuticalintelligence.com/2012/08/22/nano-particles-as-synthetic-platelets-to-stop-internal-bleeding-resulting-from-trauma/

Cardiovascular Disease (CVD) and the Role of agent alternatives in endothelial Nitric Oxide Synthase (eNOS) Activation and Nitric Oxide Production July 19, 2012

Curator and Research Study Originator: Aviva Lev-Ari, PhD, RN

http://pharmaceuticalintelligence.com/2012/07/19/cardiovascular-disease-cvd-and-the-role-of-agent-alternatives-in-endothelial-nitric-oxide-synthase-enos-activation-and-nitric-oxide-production/

Macrovascular Disease – Therapeutic Potential of cEPCs: Reduction Methods for CV Risk

July 2, 2012

An Investigation of the Potential of circulating Endothelial Progenitor Cells (cEPCs) as a Therapeutic Target for Pharmacological Therapy Design for Cardiovascular Risk Reduction: A New Multimarker Biomarker Discovery

Curator: Aviva Lev-Ari, PhD, RN

http://pharmaceuticalintelligence.com/2012/07/02/macrovascular-disease-therapeutic-potential-of-cepcs-reduction-methods-for-cv-risk/

Bone remodelling in a nutshell June 22, 2012

Author: Aviral Vatsa, Ph.D., MBBS

http://pharmaceuticalintelligence.com/2012/06/22/bone-remodelling-in-a-nutshell/

Targeted delivery of therapeutics to bone and connective tissues: current status and challenges- Part, September

AuthorL Aviral Vatsa, PhD, September 23, 2012

http://pharmaceuticalintelligence.com/2012/09/23/targeted-delivery-of-therapeutics-to-bone-and-connective-tissues-current-status-and-challenges-part-i/

Calcium dependent NOS induction by sex hormones: Estrogen

Curator: S. Saha, PhD, October 3, 2012

http://pharmaceuticalintelligence.com/2012/10/03/calcium-dependent-nos-induction-by-sex-hormones/

Nitric Oxide and Platelet Aggregation,

Author V. Karra, PhD, August 16, 2012

http://pharmaceuticalintelligence.com/2012/08/16/no-and-platelet-aggregation/

Bystolic’s generic Nebivolol – positive effect on circulating Endothelial Progenitor Cells endogenous augmentation

Curator: Aviva Lev-Ari, PhD, July 16, 2012

http://pharmaceuticalintelligence.com/?s=Nebivolol

Endothelin Receptors in Cardiovascular Diseases: The Role of eNOS Stimulation

Author: Aviva Lev-Ari, PhD, 10/4/2012

http://pharmaceuticalintelligence.com/2012/10/04/endothelin-receptors-in-cardiovascular-diseases-the-role-of-enos-stimulation/

Inhibition of ET-1, ETA and ETA-ETB, Induction of NO production, stimulation of eNOS and Treatment Regime with PPAR-gamma agonists (TZD): cEPCs Endogenous Augmentation for Cardiovascular Risk Reduction – A Bibliography

Curator: Aviva Lev-Ari, 10/4/2012.

http://pharmaceuticalintelligence.com/2012/10/04/inhibition-of-et-1-eta-and-eta-etb-induction-of-no-production-and-stimulation-of-enos-and-treatment-regime-with-ppar-gamma-agonists-tzd-cepcs-endogenous-augmentation-for-cardiovascular-risk-reduc/

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Endothelin Receptors in Cardiovascular Diseases: The Role of eNOS Stimulation

Posted in Biological Networks, Gene Regulation and Evolution, Biomarkers & Medical Diagnostics, BioSimilars, Cardiovascular Pharmacogenomics, Cell Biology, Signaling & Cell Circuits, Chemical Biology and its relations to Metabolic Disease, Disease Biology, Small Molecules in Development of Therapeutic Drugs, Frontiers in Cardiology and Cardiovascular Disorders, Health Law & Patient Safety, HTN, Nitric Oxide in Health and Disease, Origins of Cardiovascular Disease, Pharmaceutical Industry Competitive Intelligence, Pharmaceutical R&D Investment, Pharmacotherapy of Cardiovascular Disease, Population Health Management, Genetics & Pharmaceutical, Resident-cell-based, Stem Cells for Regenerative Medicine, Systemic Inflammatory Response Related Disorders, tagged Bare-metal stent, Biotechnology and Pharmaceuticals, BMS, Cardiovascular disease, Circulation Endothelial Progenitor Cells, DES, Drug-eluting stent, Endothelin Receptors, eNOS, nitric oxide, Peroxisome proliferator-activated receptor gamma, Thiazolidinedione on October 4, 2012| 17 Comments »

Endothelin Receptors in Cardiovascular Diseases: The Role of eNOS Stimulation

Author and Curator of an Investigator Initiated Study: Aviva Lev-Ari, PhD, RN

A Three Component Method for Endogenous Augmentation of cEPCs

Macrovascular Disease: The Therapeutic Potential of cEPCs

Observations on Intellectual Property Development For an Unrecognized Future Fast Acting Therapy for Patients at High Risk for Macrovascular events

ElectEagle represents a discovery of a novel “multimarker biomarker” for cardiovascular disease that innovates on four counts.

First, it proposes new therapeutic indications for acceptable drugs.

Second, it defines a specific combination of therapeutic agents, thus, it put forth a proprietary drug combination.

Third, it targets receptor systems that have not been addressed in the context of cEPCs augmentation methods. Chiefly, modulation of the following three-targeted receptor systems: (a) inhibition of ET-1, ET_A and ET_A-ET_B receptors by antagonists (b) induction of eNOS, by agonists and NO stimulation and (c) upregulation of PPAReceptor-gamma by agonists (TZD). While (b) and (c) are implicated as having favorable effects of cEPCs count, each exerting its effect by a different pathway, it is suggested in this project that (a) might be identify to be the more powerful of the three markers. Our method, ElectEagle is the FIRST to postulate the following: (1) time concentration dependence on eNOS reuptake (2) dose concentration dependence on NO production (3) time and dose concentration dependence for ET-1, ET_A and ET_A-ET_B inhibition, and (4) dose concentration dependence on PPAReceptor-gamma. Points First, Second and Third are covered in Part II where a special focus is placed on ET-1, ET_A and ET_A-ET_B receptors.

Fourth, ElectEagle proposes a platform with triple modes of delivery and use of the test, as described in Part III. The triple modes are as follows: (A) an automated platform from a centralized lab with integration to Lab’s information management system. (B) a point-of-care testing device with appropriate display of test results (small benchtop analyzers in PCP office). (C) a device used for home monitoring of analytes (the hand-held device facilitates rapid read of scores and their translation to drug concentration of each of the three therapeutic agents, with computation of the three drug concentrations done by the device. Thus, it offers quicker optimization of treatment. ElectEagle is the FIRST to propose a CVD patient kit, hand-held device, which calculates on demand an adjustable therapeutic regimen as a function of cEPCs count biomarker. In this regard, a similarity to the pump, in management of blood sugar in DM patients, exists. Since there is a high co-morbidity between DM and CVD, our methods, ElectEagle may eventually become a targeted therapy for the DM Type 2 population.

Postulates of Multiple Indications for the Method Presented: Positioning of a Therapeutic Concept for Endogenous Augmentation of cEPCs

Potential Therapeutic Indications for ElectEagle

ElectEagle can become the drug therapy of choice for the following indications:

CAD patients
Endothelial Dysfunction in DM patients with or without Erectile Dysfunction
Atherosclerosis patients: Arteries and or veins
pre-stenting treatment phase
post-stenting treatment phase
if stent is a Bare Metal stent (BMS)
if stent is Drug Eluting stent (DES)
if stent is EPC antibody coated (the ElectEagle method increase cEPCs generation in vitro) so availability of cEPCs is increased
post CABG patients (the ElectEagle enhances healing by endogenous augmentation of cEPCs)
target sub segments of CVD patients on blood thinner drugs (the ElectEagle does not require treatment with antiplatelet agents, it is suitable for all patients on Coumadin. This population have a counter indication for antiplatelet agents which is a follow up treatment after stent implantation for 30 days, with stent-eluting long term regimen of antiplatelet agents, 6 months and in some cases indefinitely (Tung, 2006).
ElectEagle is based on systemic therapeutics (versus the localized stent solution requiring multiple and even overlapping stents)
ElectEagle will be having potential in two contexts

1. Coronary disease

2. Periphery vascular disease

Comparative analysis of endogenous and exogenous cEPCs augmentation methods:

A. endogenous augmentation method properties:

temporal – while drug therapy in use – drug action is interruptible
time concentration on eNOS reuptake
dose concentration on NO production
time and dose concentration manner for ETB inhibition
dose concentration on PPAR-gamma

B. cell-based and other exogenous methods

permanent colonization till apoptosis if no repeated attempts of re-transfer, re-implantation as the protocol usually has several stages

ElectEagle will be resulting in potential delay of stenting implantation. Patients that are target for stenting may benefit form ElectEagle that will facilitate and accelerate healing after the stent is in place. EPC antibody coated stents will work if and only if the patient has more that just low cEPCs, most patient undergoing stenting tend to have low level of cEPC. The ElectEagle method can be coupled with that type of new stents, called Genous, now in clinical trials (HEALING II, III). These stents enhance the body ability in mobilization of cEPCs, only. However, if the initial population of cEPCs is low, an endogenous fast acting cell augmentation method is needed for pretreatment before the PCI procedure with Genous is scheduled.

Mechanism of action (MOA) for ElectEagle‘s component 1

Inhibition of ET-1, ET_A and ET_A-ET_B

Source for vasodilators substances in the endothelium are PGI2 and NO. A potent vasoconstrictor peptide is the endothelin family, first isolated in the aortic endothelial cells.

Endothelins: Biosynthesis, Structure & Clearance

Three isoforms of endothelin (ET) have been identified. ET-1, ET-2 and ET-3. Each isoform is the product of a different gene and is synthesized as a prepro form that is processed to a propeptide and then to the mature peptide. Endothelin-converting enzyme (ECE) converts a prepro into a mature peptide. Each ET is a 21-amino-acid peptide containing two disulfide bridges. ETs are widely distributed in the body. ET-1 is the predominant ET secreted by the vascular endothelium. It is also produced by neurons and astrocytes in CNS and in endometrial, renal mesangial, sertoli, breast epithelial and other cells. ETs are present in the blood in low concentrations, they act locally in a paracrine or autocrine fashion rather than as circulating hormones.

Expression of ET-1 gene is increased by Growth Factors and cytokines, transforming factor-beta (TGF-beta) and interleukin 1 (IL-1), vasoactive substances including angiotensin II and vasopressing and mechanical stress. Expression is inhibited by NO, prostacyclin and ANP (source for vasodilators substances in the endothelium are PGI2 and NO.) Clearance of ETs from the circulation is rapid and involves enzymatic degradation by NEP 24.11 and clearance by the ET_B receptor.

Endothelins: Action

ET exerts many actions on the body. In particular dose-dependent vasoconstriction in most vascular beds. Intravenous administration of ET-1 causes a rapid decease in BP followed by a prolonged increase. The depressor response results PGI2 and NO release from the vascular endothelium. The pressor response is due to direct constriction of vascular smooth muscle. ETs exert direct positive inotropic and chronotropic actions on the heart and are potent coronary vasoconstrictors. ETs actions on other organ is described in (Reid, 2004). ETs interact with several endocrine systems, increase secretion of renin, aldosterone, vasopressin and Atrial natriuretic peptide (ANP.) Action exerted on CNS and PNS, GI system, liver, GU, reproductive system, eye, skeletal and skin. ET-1 is a potent mitogen for vascular smooth muscle cells, cardiac myocytes and glomerular mesangial cells.

ET receptors are present in many tissues and organs, blood vessel wall, cardiac muscle, CNS, lung, kidney, adrenal, spleen, and GI. The signal transduction mechanism triggered by binding of ET-1 to its receptors, ET_A & ET_B includes effects of stimulation of phospholipase C, formation of inositol triphosphate and release of calcium from the ER which results in vasoconstriction. Stimulation of PGI2 and NO synthesis result in decreased intracellular calcium concentration and vasodilation.

Two receptor subtypes, ET_A & ET_Bhave been cloned and sequenced. ET_A receptors have a high affinity for ET-1 and a low affinity for ET-3 and are located on smooth muscle cells, where they mediate vasoconstriction. ET_B receptors have an equal affinity for ET-1 and ET-3 and are located on vascular ECs, where they mediate release of PGI2 and NO. Both receptor types belong to the G protein-coupled seven-transmembrane domain family of receptors.

Inhibitors of Endothelin Synthesis & Action

ETs can be blocked with receptor antagonists and with drugs that block the Endothelin-converting enzyme (ECE), Endothelin-converting enzyme inhibitors (ECEI). Two receptor subtypes, ET_A & ET_Bcan be blocked selectively, or both can be blocked with nonselective ET_A – ET_Bantagonists. Bosentan is a nonselective antagonist, available both intravenously and orally. It blocks the initial transient depressor (ET_B ) and the prolonged pressor (ET_A) responses to intravenous ET. Oral ET antagonists are available for research purposes. The formation of Endothelin-converting enzyme (ECE) can be blocked with Phosphoramidon. The therapeutic potential of ECEI is similar to that of the ET receptor antagonist, Bosentan, an active competitive inhibitor of ET [it has teratogenic and hepatotexic effects].

Physiologic & Pathologic Roles of Endothelin Antagonists

Systemic administration of ET receptor antagonists or ECEI causes vasodilation and decreases arterial pressure in human and in experimental animals. Intra-arterial administration of the drugs also causes slow-onset forearm vasodilation in humans. This is an evidence that the endothelin system participates in the regulation of vascular tone, even under resting conditions (Reid, 2004).

There is evidence that ETs participate in CVD, including hypertension, cardiac hypertrophy, CHF, atherosclerosis, CAD, MI. ETs have been implicated in pulmonary diseases, PA HTN, asthma, renal diseases. Increased ET levels was found in the blood, increased expression of ET mRNA in endothelial or vascular smooth muscle cells and the responses to administration of ET antagonists. ET antagonists have potential for treatment of these diseases. In clinical trials, Bosentanand other nonselective antagonists as well as ET_A selective antagonists produce beneficial effects on hemodynamics and symptoms of CHF, PA HTN and essential HTN (Sütsch et al., 1998), (Haynes, 1996), (Lahav et al., 1999). Currently, it is approved for use in pulmonary hypertension (Benowitz, 2004).

ElectEagle Project Drug combination Therapy has selected Bosentan or other nonselective ET antagonists as well as ET_A selective antagonists to enhance the effects an eNOS agonist and a PPAR-gamma agonist will have on CVD patient’s propensity to achieve beneficial effects for endogenous augmentation of cEPCs. The impact the ETs have on the body is of a very wide range and of a most important from a physiological point of view, respectively, we did not leave Big ET-1 out of the therapeutic treatment design.

Proposed integration plan for ElectEagle’s Version I with CVD patients current medication regimen for selective medical diagnoses

Blood Pressure Medicine:

Beta blockers, Verapamil (Calan), Reserpine (Hydropes), Clonidine (Catapres), Methyldopa (Aldomet)

Diuretics:

Thiazides, Spironolactone (Aldactone), Hydralazine

Antidepressants:

Prozac, Lithium, MOA’s, Tricyclics

Stomach Medicine:

Tagamet and Zantac, plus other compounds containing Cimetidine and Ranitidine or associated compounds in Anticholesterol Drugs

Antipsychotics:

Chlorpromazine (Thorazine), Pimozide (Orap), Thiothixine (Navane), Thiordazine (Mellaril), Sulpiride, Haloperidol (haldol), Fluphenazine (Modecate, Prolixin)

Heart Medicine:

Clofibrate (Atromid), Gemfibrozil, Diagoxin

Hormones:

Estrogen, Progesterone, Proscar, Casodex, Eulexin, Corticosteroids Gonadotropin releasing antagonists: Zoladex and Lupron

Cytotoxic agents:

Cyclophosphamide, Methotrexate, Roferon Non-steroidal anti-inflammatories

Others

Alprazolam, Amoxapine, Chlordiazepoxide, Sertraline, Paroxetine, Clomipramine, Fluvoxamine, Fluoxetine, Imipramine, Doxepine, Desipramine, Clorprothixine, Bethanidine, Naproxen, Nortriptyline, Thioridazine, Tranylcypromine, Venlafaxine, Citalopram.

INTERACTIONS for Nebivolol

Calcium Antagonists:

Caution should be exercised when administering beta-blockers with calcium antagonists of the verapamil or diltiazem type because of their negative effect on contractility and atrio-ventricular conduction. Exaggeration of these effects can occur particularly in patients with impaired ventricular function and/or SA or AV conduction abnormalities. Neither medicine should therefore be administered intravenously within 48 hours of discontinuing the other.

Anti-arrhythmics:

Caution should be exercised when administering beta-blockers with Class I anti-arrhythmic drugs and amiodarone as their effect on atrial conduction time and their negative inotropic effect may be potentiated. Such interactions can have life threatening consequences.

Clonidine:

Beta-blockers increase the risk of rebound hypertension after sudden withdrawal of chronic clonidine treatment.

Digitalis:

Digitalis glycosides associated with beta-blockers may increase atrio-ventricular conduction times. Nebivolol does not influence the kinetics of digoxin & clinical trials have not shown any evidence of an interaction.

Special note: Digitalisation of patients receiving long term beta-blocker therapy may be necessary if congestive cardiac failure is likely to develop. The combination can be considered despite the potentiation of the negative chronotropic effect of the two medicines. Careful control of dosages and of individual patient’s response (notably pulse rate) is essential in this situation.

Insulin & Oral Antidiabetic drugs:

Glucose levels are unaffected, however symptoms of hypoglycemia may be masked.

Anaesthetics:

Concomitant use of beta-blockers & anaesthetics e.g. ether, cyclopropane & trichloroethylene may attenuate reflex tachycardia & increase the risk of hypotension

Testing ElectEagle’s a-priori postulates presented in Part I

a-priori postulates presented in Part I for Component 1:ET-1, ET_A and ET_A-ET_B inhibition

time and dose concentration dependence for ET_A and ET_A-ET_B inhibition

In the literature we found evidence for dose concentration dependence manner (Reid, 2004).

ET_A and ET_A-ET_B inhibitor	time concentration dependence manner	dose concentration dependencemanner	time and dose	dose
Bosentan		(Reid, 2004)		62.5, 125 mg tablets

a-priori postulates presented in Part I for Component 2: NO, eNOS induction and stimulation

time concentration dependence on eNOS reuptake
dose concentration dependence on NO production

In the literature we found evidence for dose concentration dependence manner

Ach, Histamine, Genistein, ACEI, Fenofibrates, NEBIVOLOL, Calcium channel blocker, Enzyme S-nitrosylation

In the literature we found evidence for time concentration dependence manner:

Ach, BRL37344, a 3-adrenoceptor agonist

In the literature we found evidence for time and dose concentration dependence manner:

Histamine

NO, eNOS AgonistsStimulate phosphorylation of eNOS at serine 1177, 1179, 116 Conversion of L-arginine toL-citrulline	time concentration dependence manner	dose concentration dependencemanner	time and dose	dose (nmol·mg of protein-1) Grovers et al., (2002)
A23187				(5µM)
Acetylcholine	Xu et al., (2002)	Sanchez et al., (2006)		(1µM)
5-Hydroxytryptamine				(1µM)
VEGF (				(20ng/ml)
Bradykinin				(1µM)
Histamine		McDuffie et al., (1999)	McDuffie et al., (2000)	(10µM)
genistein		Liu et al., (2004)		(1µM)
ACEI		Skidgel et al., (2006)
Fenofibrates		Asai et al., (2006)
BRL37344, a 3-adrenoceptor agonist	Pott et al., (2005)
NEBIVOLOLß1-selective adrenergic receptor antagonist with nitric oxide (NO)–mediation for vasodilation		Ritter et al., (2006)
Calcium channel blocker		Church and Fulton, (2006),
Enzyme S-nitrosylation		Erwin et al., (2006)

a-priori postulates presented in Part I for Component 3: PPAR-gamma

dose concentration dependence on PPAReceptor-gamma – confirmed by a study for Rosiglitazone and a study for Ciglitazone

PPAReceptor-gamma agonists	time concentration dependence manner	dose concentration dependencemanner	time and dose	dose
Rosiglitazone		Polikandriotis et al., (2005)		maximum recommended daily dose of 8 mg to 2,000 mg.
Ciglitazone		Polikandriotis et al., (2005)

Development of an Experimental Treatment Protocol for

ElectEagle Version I

Therapeutic Strategy for cEPCs Endogenous Augmentation for measuring the number of circulating Endothelial Progenitor Cells (cEPCs) before and after a newly design treatment with Pharmacological agents

Component 1: Inhibition of ET-1, ET_A and ET_A-ET_B

Bosentan (Tracleer) Oral: 62.5, 125 mg tablets

Component 2: Induction of NO production and stimulation of eNOS

Nebivolol – ß1-selective adrenergic receptor antagonist with nitric oxide (NO)– mediation for vasodilation

A single daily dose of 5 mg was appropriate, with no evident advantage at 10 mg (Van Nueten et al.,1997)

Component 3: Treatment Regime with PPAR-gamma agonists (TZD)

A Substitute for Rosiglitazone, 2-8 mg once daily

The combination drug therapy for endogenous augmentation of cEPCs in CVD patients for achievement of reduction in risk for macrovascular events is recommended to be applied for Clinical Trial Phase One in the following regimen:

Use the following combination of drugs for the following Stages

Bosentan (Tracleer), Oral: 62.5 mg tablets

Nebivolol, Oral: 5mg once daily

A substitute for Rosiglitazone, 8 mg once daily

Stage 1: ET-1 Antagonist Effect on eEPC

1.0 Measurement of the Baseline of number of cEPC

1.1 Administer ET-1 antagonist for 10 days

1.2 Measurement of number of cEPC after 10 days of treatment with ET-1 antagonist

Stage 2: Nitric Oxide Effect on cEPC

2.0 Measurement of number of cEPC obtained in 1.2

2.1 Administer Nitric Oxide Agonist for 10 days

2.2 Measurement of number of cEPC after 10 days of

treatment with Nitric Oxide Agonist

Stage 3: Comparison of ET-1 and NO Effects on cEPC Proliferation

3.0 Comparison of number of cEPC in 1.2 to 2.2

¨ IF number of cEPC in 1.2 > number of cEPC in 2.2

-> continue 1.1 only

[ET-1 antagonist more effective for proliferation of cEPC than NO Agonist]

3.1.1 Measurement of number of cEPC every 10 days

¨ IF number of cEPC in 1.2 < number of cEPC in 2.2

-> continue 2.1 only

[ET-1 antagonist less effective for proliferation of cEPC than NO Agonist]

3.2.1 Measurement of number of cEPC every 10 days

¨ IF number of cEPC in 1.2 = number of cEPC in 2.2

-> continue 1.1 AND 2.1

[ET-1 antagonist equal NO Agonist in effectiveness for proliferation of cEPC]

-> Administer a Combination therapy of ET-1 antagonist and NO Agonist for 10 days

3.3.1 Measurement of number of cEPC every 10 days

Stage 4: ET-1 and/or NO Effect on Cardiovascular (CV) Events

q After 12 months Comparison of CV events in patient population in

Stage 3.1, 3.2, 3.3

Cardiovascular events in patients in 3.1
Cardiovascular events in patients in 3.2
Cardiovascular events in patients in 3.3

Conclusions

Most favorable and unexpected to us was finding in the literature new indications for TDZs as stimulators of eNOS, in addition to the new indication for atherosclerosis besides the classic indication in pharmacology books, being in the reduction of insulin resistance. Reassuring our selection of a substitute for Rosiglitazone.
Most favorable and unexpected to us was finding in the literature new indications for beta blockers as NO stimulant, nebivolol, a case in point, thus, fulfilling two indications in one drug along the direction of the study to identify eNOS agonists.
The following combination of drugs was selected for ElectEagle Version I

Bosentan (Tracleer), Oral: 62.5 mg tablets

Nebivolol, Oral: 5mg once daily

A Substitute for Rosiglitazone, 8 mg once daily

We confirmed time and dose concentrations postulating apriori in most cases. Additional literature searches will benefit the project for the three drugs selected
We have identified Inhibition of ET-1, ET_A and ET_A-ET_Bas one of the agent in the drug combination. The entire literature on cEPCs does not implicate Endothelin with impact on eEPCs while it is known that mechanical stress increase its secretion, this type of stress is implicated with hypertension. To leave out ET-1 from the cEPCs function in CVD risk equates to leaving out Thrombin from the coagulation cascade. ElectEagle Version I corrects that ommission.

REFERENCES

Benowitz, NL., (2004). Antihypertensive Agents. Chapter 11 in Katzung, BG., Basic & Clinical Pharmacology. McGraw-Hill, 9th Edition, pp. 160-183.

Haynes WG, Ferro CJ, O’Kane KP, Somerville D, Lomax CC, Webb DJ, (1996). Systemic endothelin receptor blockade decreases peripheral vascular resistance and blood pressure in humans. Circulation, 15;93(10):1860-70.

N S Kirkby, P W F Hadoke, A J Bagnall, and D J Webb (2008)

The endothelin system as a therapeutic target in cardiovascular disease: great expectations or bleak house? Br J Pharmacol. 2008 March; 153(6): 1105–1119.

Ohkita Mamoru, Masashi Tawa, Kento Kitada and Yasuo Matsumura (2012). Pathophysiological Roles of Endothelin Receptors in Cardiovascular Diseases, J Pharmacol Sci 119, 302 – 313 (2012)

Reid, Ian A., (2004). Vasoactive Peptides. Chapter 17 in Katzung, BG., Basic & Clinical Pharmacology. McGraw-Hill, 9th Edition, pp. 281 – 297, in particular, Endothelins, pp. 290-293.

For a comprehensive Bibliography on the Three Therapeutic Componenets and the pathophysiology of Cardiovascular Disease, follow this link:

Other aspects of Nitric Oxide involvement in biological systems in humans are covered in the following posts on this site:

Nitric Oxide in bone metabolism July 16, 2012

Author: Aviral Vatsa PhD, MBBS

http://pharmaceuticalintelligence.com/2012/07/16/nitric-oxide-in-bone-metabolism/?goback=%2Egde_4346921_member_134751669

Nitric Oxide production in Systemic sclerosis July 25, 2012

Curator: Aviral Vatsa, PhD, MBBS

http://pharmaceuticalintelligence.com/2012/07/25/nitric-oxide-production-in-systemic-sclerosis/?goback=%2Egde_4346921_member_138370383

Nitric Oxide Signalling Pathways August 22, 2012 by

Curator/ Author: Aviral Vatsa, PhD, MBBS

http://pharmaceuticalintelligence.com/2012/08/22/nitric-oxide-signalling-pathways/?goback=%2Egde_4346921_member_151245569

Nitric Oxide: a short historic perspective August 5, 2012

Author/Curator: Aviral Vatsa PhD, MBBS

http://pharmaceuticalintelligence.com/2012/08/05/nitric-oxide-a-short-historic-perspective-7/

Nitric Oxide: Chemistry and function August 10, 2012

Curator/Author: Aviral Vatsa PhD, MBBS

http://pharmaceuticalintelligence.com/2012/08/10/nitric-oxide-chemistry-and-function/?goback=%2Egde_4346921_member_145137865

Nitric Oxide and Platelet Aggregation August 16, 2012 by

Author: Dr. Venkat S. Karra, Ph.D.

http://pharmaceuticalintelligence.com/2012/08/16/no-and-platelet-aggregation/?goback=%2Egde_4346921_member_147475405

The rationale and use of inhaled NO in Pulmonary Artery Hypertension and Right Sided Heart Failure August 20, 2012

Author: Larry Bernstein, MD

http://pharmaceuticalintelligence.com/2012/08/20/the-rationale-and-use-of-inhaled-no-in-pulmonary-artery-hypertension-and-right-sided-heart-failure/

Nitric Oxide: The Nobel Prize in Physiology or Medicine 1998 Robert F. Furchgott, Louis J. Ignarro, Ferid Murad August 16, 2012

Reporter: Aviva Lev-Ari, PhD, RN

http://pharmaceuticalintelligence.com/2012/08/16/nitric-oxide-the-nobel-prize-in-physiology-or-medicine-1998-robert-f-furchgott-louis-j-ignarro-ferid-murad/

Coronary Artery Disease – Medical Devices Solutions: From First-In-Man Stent Implantation, via Medical Ethical Dilemmas to Drug Eluting Stents August 13, 2012

Author: Aviva Lev-Ari, PhD, RN

http://pharmaceuticalintelligence.com/2012/08/13/coronary-artery-disease-medical-devices-solutions-from-first-in-man-stent-implantation-via-medical-ethical-dilemmas-to-drug-eluting-stents/

Nano-particles as Synthetic Platelets to Stop Internal Bleeding Resulting from Trauma

August 22, 2012

Reported by: Dr. V. S. Karra, Ph.D.

http://pharmaceuticalintelligence.com/2012/08/22/nano-particles-as-synthetic-platelets-to-stop-internal-bleeding-resulting-from-trauma/

Cardiovascular Disease (CVD) and the Role of agent alternatives in endothelial Nitric Oxide Synthase (eNOS) Activation and Nitric Oxide Production July 19, 2012

Curator and Research Study Originator: Aviva Lev-Ari, PhD, RN

http://pharmaceuticalintelligence.com/2012/07/19/cardiovascular-disease-cvd-and-the-role-of-agent-alternatives-in-endothelial-nitric-oxide-synthase-enos-activation-and-nitric-oxide-production/

Macrovascular Disease – Therapeutic Potential of cEPCs: Reduction Methods for CV Risk

July 2, 2012

Curator: Aviva Lev-Ari, PhD, RN

http://pharmaceuticalintelligence.com/2012/07/02/macrovascular-disease-therapeutic-potential-of-cepcs-reduction-methods-for-cv-risk/

Bone remodelling in a nutshell June 22, 2012

Author: Aviral Vatsa, Ph.D., MBBS

http://pharmaceuticalintelligence.com/2012/06/22/bone-remodelling-in-a-nutshell/

Targeted delivery of therapeutics to bone and connective tissues: current status and challenges- Part, September

AuthorL Aviral Vatsa, PhD, September 23, 2012

http://pharmaceuticalintelligence.com/2012/09/23/targeted-delivery-of-therapeutics-to-bone-and-connective-tissues-current-status-and-challenges-part-i/

Calcium dependent NOS induction by sex hormones: Estrogen

Curator: S. Saha, PhD, October 3, 2012

http://pharmaceuticalintelligence.com/2012/10/03/calcium-dependent-nos-induction-by-sex-hormones/

Nitric Oxide and Platelet Aggregation,

Author V. Karra, PhD, August 16, 2012

http://pharmaceuticalintelligence.com/2012/08/16/no-and-platelet-aggregation/

Bystolic’s generic Nebivolol – positive effect on circulating Endothelial Progenitor Cells endogenous augmentation

Curator: Aviva Lev-Ari, PhD, July 16, 2012

http://pharmaceuticalintelligence.com/?s=Nebivolol

Endothelin Receptors in Cardiovascular Diseases: The Role of eNOS Stimulation

Author: Aviva Lev-Ari, PhD, 10/4/2012

http://pharmaceuticalintelligence.com/2012/10/04/endothelin-receptors-in-cardiovascular-diseases-the-role-of-enos-stimulation/

Curator: Aviva Lev-Ari, 10/4/2012.

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Author and Reporter: Meg Baker, 10/7/2012.

http://pharmaceuticalintelligence.com/2012/10/07/no-nutritional-remedies-for-hypertension-and-atherosclerosis-its-12-am-do-you-know-where-your-electrons-are/

Drug Information

Component 1: Inhibition of ET-1, ET_A and ET_A-ET_B

Bosentan (Tracleer)

BACKGROUND: Although local inhibition of the generation or actions of endothelin-1 has been shown to cause forearm vasodilatation, the systemic effects of endothelin receptor blockade in healthy humans are unknown. We therefore investigated the cardiovascular effects of a potent peptide endothelin ETA/B receptor antagonist, TAK-044, in healthy men. METHODS AND RESULTS: Two randomized, placebo-controlled, crossover studies were performed. In nine subjects, TAK-044 (10 to 1000 mg IV over a 15-minute period) caused sustained dose-dependent peripheral vasodilatation and hypotension. Four hours after infusion of the highest dose (1000 mg), there were decreases in mean arterial pressure of 18 mm Hg and total peripheral resistance of 665 AU and increases in heart rate of 8 bpm and cardiac index of 0.9 L x min(-1) x m(-2) compared with placebo. TAK-044 caused a rapid, dose-dependent increase in plasma immunoreactive endothelin (from 3.3 to 35.7 pg/mL within 30 minutes after 1000 mg). In a second study in eight subjects, intravenous administration of TAK-044 at doses of 30, 250, and 750 mg also caused peripheral vasodilatation, and all three doses abolished local forearm vasoconstriction to brachial artery infusion of endothelin-1. Brachial artery infusion of TAK-044 caused local forearm vasodilation. CONCLUSIONS: The endothelin ETA/B receptor antagonist TAK-044 decreases peripheral vascular resistance and, to a lesser extent, blood pressure; increases circulating endothelin concentrations; and blocks forearm vasoconstriction to exogenous endothelin-1. These results suggest that endogenous generation of endothelin-1 plays a fundamental physiological role in maintenance of peripheral vascular tone and blood pressure. The vasodilator properties of endothelin receptor antagonists may prove valuable therapeutically (Haynes et al., 1996).

http://www.tracleer-pph.com/

http://www.medicinenet.com/script/main/art.asp?articlekey=44221&pf=3&page=1

GENERIC NAME: BOSENTAN – ORAL (boh-SEN-tan)

BRAND NAME(S): Tracleer

WARNING: This medication may cause serious liver problems. Your doctor should monitor your liver function closely to decrease your risk of liver-related side effects. Tell your doctor immediately if you notice any of these symptoms of liver problems: nausea, vomiting, stomach pain, unusual tiredness, and yellowing eyes or skin. These effects, if they occur, may go away over time (are reversible). This medication must not be used during pregnancy because it can cause fetal harm (e.g., birth defects). See the pregnancy warning information below (in Precautions section).

USES: Bosentan is used to treat a condition of high blood pressure in the lungs (pulmonary arterial hypertension). It works by causing the blood vessels (arteries) in the lungs to relax and expand, thus decreasing the pressure.

HOW TO USE: Before using, review the bosentan Medication Guide for information on the safe use of this medicine. Take this medication by mouth usually twice daily in the morning and evening with or without food; or as directed by your doctor. The dosage is based on your medical condition and response to therapy. Your doctor may recommend to gradually increase your dose over time so your body may better adjust to the effects of this drug. Do not stop taking this medication without consulting your doctor. Some conditions may become worse when the drug is abruptly stopped. Your dose may need to be gradually decreased.

SIDE EFFECTS: Headache, nose/throat irritation, itching, flushing, or stomach upset may occur. If any of these effects persist or worsen, notify your doctor or pharmacist promptly. Tell your doctor immediately if any of these unlikely but serious side effects occur: irregular heartbeat, unusual tiredness and weakness, swelling of the feet or ankles, trouble breathing, dizziness or lightheadedness. If you notice any of the following very serious side effects of liver problems, stop taking bosentan and consult your doctor immediately: vomiting, stomach pain, yellowing eyes or skin. A serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction include: rash, itching, swelling, dizziness, severe trouble breathing. If you notice other effects not listed above, contact your doctor or pharmacist.

PRECAUTIONS: Tell your doctor your medical history, especially of: liver problems, blood disorders (e.g., anemia), any allergies. Caution is advised when using this drug in the elderly because they may be more sensitive to the effects of the drug. This medication must not be used during pregnancy because it may cause fetal harm. If you are pregnant or think you may be pregnant, do not take this medication and consult your doctor immediately. It is recommended that you use two reliable forms of birth control while taking this medicine. It is also recommended to have a pregnancy test done before treatment and every month during treatment with this drug. It is not known whether this drug passes into breast milk. Because of the potential risk to the infant, breast-feeding while using this drug is not recommended.

DRUG INTERACTIONS: This drug is not recommended for use with: cyclosporine, glyburide. Ask your doctor or pharmacist for more details. Tell your doctor of all prescription and nonprescription medication you may use, especially: azole antifungals (e.g., itraconazole, ketoconazole), statins for high cholesterol (e.g., lovastatin, simvastatin), HIV protease inhibitors (e.g., indinavir, ritonavir), tacrolimus. This medication may decrease the effectiveness of combination-type birth control pills. This can result in pregnancy. You may need to use an additional form of reliable birth control while using this medication. Consult your doctor or pharmacist for details. Do not start or stop any medicine without doctor or pharmacist approval.

OVERDOSE: If overdose is suspected, contact your local poison control center or emergency room immediately. US residents can call the US national poison hotline at 1-800-222-1222. Canadian residents should call their local poison control center directly.

NOTES: Do not share this medication with others. Laboratory and/or medical tests (e.g., liver function tests- LFT’s, blood tests) will be performed to monitor your progress and for side effects.

MISSED DOSE: If you miss a dose, use it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.

STORAGE: Store at room temperature between 68 and 77 degrees F (20 and 25 degrees C) away from light and moisture. Brief storage between 59 and 86 degrees F (15 and 30 degrees C) is permitted.

MEDICAL ALERT: Your condition can cause complications in a medical emergency. For enrollment information call MedicAlert at 1-800-854-1166 (USA), or 1-800-668-1507

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Inhibition of ET-1, ETA and ETA-ETB, Induction of NO production, stimulation of eNOS and Treatment Regime with PPAR-gamma agonists (TZD): cEPCs Endogenous Augmentation for Cardiovascular Risk Reduction – A Bibliography

Posted in Bio Instrumentation in Experimental Life Sciences Research, Biomarkers & Medical Diagnostics, BioSimilars, Cell Biology, Signaling & Cell Circuits, Chemical Biology and its relations to Metabolic Disease, Disease Biology, Small Molecules in Development of Therapeutic Drugs, Frontiers in Cardiology and Cardiovascular Disorders, HTN, Nitric Oxide in Health and Disease, Origins of Cardiovascular Disease, Pharmaceutical Industry Competitive Intelligence, Pharmaceutical R&D Investment, Pharmacotherapy of Cardiovascular Disease, Resident-cell-based, Stem Cells for Regenerative Medicine, tagged Cell Biology, Endothelial microparticle, Endothelium, nitric oxide, Nitric oxide synthase on October 4, 2012| 14 Comments »

Curator of an Investigator Initiated Study: Aviva Lev-Ari, PhD, RN

Inhibition of ET-1, ET_A and ET_A-ET_B, Induction of NO production, stimulation of eNOS and Treatment Regime with PPAR-gamma agonists (TZD): cEPCs Endogenous Augmentation for Cardiovascular Risk Reduction – A Bibliography

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Nebivolol is a long-acting, cardioselective beta-blocker currently licensed for the treatment of hypertension.

Nebivolol

http://www.intekom.com/pharm/adcock/nebilet.html – retrieved on 6/20/2006

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Building a Drug-Delivery System(DDS): choice of polymers and drugs

Posted in Biomarkers & Medical Diagnostics, BioSimilars, CANCER BIOLOGY & Innovations in Cancer Therapy, Cell Biology, Signaling & Cell Circuits, Chemical Biology and its relations to Metabolic Disease, Disease Biology, Small Molecules in Development of Therapeutic Drugs, Nanotechnology for Drug Delivery, Pharmaceutical Analytics, Pharmaceutical Industry Competitive Intelligence, Pharmaceutical R&D Investment, tagged Biology, Cancer - General, Proceedings of the National Academy of Sciences of the United States of America on October 4, 2012| 3 Comments »

Author: Tilda Barliya PhD

Title: Building a DSS: choice of polymers and drugs

Category: Nanotechnology and drug delivery

During the last 40 years, controlled drug delivery has become one of the most challenging and rapidly advancing scientific areas. Delivery systems can offer numerous advantages compared to conventional dosage forms. This coalition of polymeric science and pharmaceutical science led to the innovation in the design and development of drug delivery systems (DDS). Some of the challenges of most drug delivery systems include poor bioavailability, in vivo stability, solubility, intestinal absorption, sustained and targeted delivery to site of action, therapeutic effectiveness, side effects and patient compliance as well as plasma fluctuations of drugs which either fall below the minimum effective concentrations or exceed the safe therapeutic concentrations.

The purpose of these polymers in such system is to increase the delivery effectiveness of drugs to pathological cells by protecting them from degradation in the physiological environment, localize the drug to the desired site and be non-toxic. (1,3,4 ).

Grund S and colleagues nicely outlined the history of polymer-based drug delivery system, the types of polymers and drug combinations (1).

Classification:

– Origin (synthetic, natural or both)

– Chemical nature (polyester, polyanhydride etc)

– Backbone stability (biodegradable or not)

– Water solubility (hydrophilic, hydrophobic) and Electrical charges

Although intertwined, delivery systems can be generally grouped as:

– Biodegradable drug delivery systems

– Diffusion controlled drug delivery system

– Responsive drug delivery system (thermo, pH, enzymatic)

These DDS systems among others are differentiated on the basis of the mechanism controlling the release of the drug from the polymers (1,2).

Biodegradable polymers disintegrate into biocompatible compounds when exposed to chemicals (like water), enzymes or microbial which leaves the incorporated drug behind. The drug molecule present in the DDS is released due to the process of erosion. Moreover, the degradation of the polymers involves breakdown of polymers and reduction by the Kreb’s cycle to carbon dioxide and water. Furthermore, biodegradable polymers can be manipulated by the addition of functional/liable groups such as: esters, amine, urea, anhydride, carbonates etc to the backbone. Here are some examples to the most common biodegradable polymers; polyesters, polyacrylic acids, polyanhydride, polyurea etc

Diffusion controlled-polymer systems involve the dispersion of the therapeutic molecule within the polymer shell. The sustained release of the drug from this system is driven by diffusion through the pores or between the polymer chains. Drug: Progestasert (intra-uterine), Nicoderm (transdermal)

Responsive drug delivery systems release the drug in a more controlled manner which can be stimulated by the surrounding such as temperature, solvent, pH and/or concentration. Poly (N-isopropylacrylamide) is a well known example for a thermo-responsive polymer. Poly (ethylene glycol), poly lactic acid etc are known to be used for their thermogelling system. Drug: Atridox.

A different way to approach drug delivery system is:

– Temporal controlled

– Distribution controlled

In temporal control DDS, the aim is to deliver the drug a specific time during the treatment and controlled release over extended duration is highly beneficial for drugs that are rapidly metabolized and eliminated from the body after administration (2)

in distribution controlled DDS, the aim is to the deliver the drug to a specific site in the body. This delivery system is highly beneficial when natural distribution encounter body cells and cause major side effects that prohibit further treatment ( i.e chemotherapy) or when natural distribution can’t be facilitated using the regular systemic system (i.e passing the BBB and reaching brain tumors)

The choice of drugs imposed various restrictions on the type of the delivery system employed.

For example, a drug that is to be released over an extended period in a patient’s stomach where the pH is acidic and environmental conditions fluctuate widely will require a controlled release system very different from that of a drug that is to be delivered in a pulsatile manner within the blood system.

It is also very important to understand the fate of the polymer after the drug has been released, such as polymers that naturally excreted from the body (kidneys), removed after the drug release (patch or and insert) or extract through the GI track, are acceptable in medical application.

Four physicochemical properties of polymers can affect the opsonisation process and determine the degree of RES clearance (1):

Charge
Molecular size
Shape
Hydrophobicity/lipophilicity

In summary

Polymer science has become the motor for the development of new drug delivery systems in the past decades and requires an increasingly intensive cooperation between chemists, technologists and biologists.

“Over the years, especially induced by the introduction of micro- and nanosized carriers, they have changed their profile to parenteral drug applications and are now capable of offering advanced, more sophisticated and multifunctional approaches such as stealth effects and drug targeting for medicines. Combination therapy applying multiple types of drugs concurrently with one single drug delivery system will lead to more effective therapeutics and a more convenient application for the patients”

Novel, tailored polymers with more complicated and complex structures and functions may influence many related scientific and regulatory fields. However, several questions regarding regulatory approval of polymer-based carriers are still pending, and the establishment of new guidelines and policies especially adapted to nanosized polymer materials and their unique properties is still in the beginning. New criteria to determine identity, purity, and stability of the materials during manufacturing and storage have to be
defined and confirmed by new validated analytical methods.

References

Grund S, Bauer M and Fischer D. Polymers in drug delivery-State of the art and future trends. Advanced Engineering Materials 2011, 13(3); B61-B87. http://onlinelibrary.wiley.com/doi/10.1002/adem.201080088/abstract
Unrich K.E, Cannizzaro S.N and Langer R.S. Polymeric systems for controlled Drug release. Chem. Rev. 1999, 99; 3181−3198. http://www.qmc.ufsc.br/qmcweb/artigos/dor/bonus/Polymeric%20Systems%20for%20Controlled%20Drug%20Release.pdf
Mody V.V. Introduction ro polymeric drug delivery. Internet journal of medical update 2010; 5(2): 1-2 http://www.akspublication.com/Editorial_Jul2010_.pdf
Muhammad T, Nur Z, Piletska E.V, Yimit O and Piletsky S.A.Rational design of molecularly imprinted polymer: the choice of cross-linker. Analyst. 2012 Jun 7;137(11):2623-8. Epub 2012 Apr 26. http://pubs.rsc.org/en/content/articlelanding/2012/AN/C2AN35228
Torchilin VA. Polymeric Immunomicelles: Carriers of Choice for Targeted Delivery of Water-Insoluble Pharmaceuticals. Drug Delivery Tech 2004: 4(2). http://www.drugdeliverytech.com/ME2/dirmod.asp?sid=&nm=&type=Publishing&mod=Publications%3A%3AArticle&mid=8F3A7027421841978F18BE895F87F791&tier=4&id=5F2B931260F14B7786C80C84E46AEC1
William B. Liechty W.B, David R. Kryscio D.R, Brandon V. Slaughter B.V and Peppas N.A. Polymers for Drug Delivery Systems. Annual Review of Chemical and Biomolecular Engineering 2010 1: 149-173. http://www.annualreviews.org/doi/abs/10.1146/annurev-chembioeng-073009-100847.
Chen Y and Liu L. Modern methods for delivery of drugs across the blood–brain barrier. Adv Drug Deliv Rev 2012: 64(7); 640-665. http://www.sciencedirect.com/science/article/pii/S0169409X11002900.
Kaparissides C, Alexandridou S, Kotti K and Chaitidou S. Recent Advances in Novel Drug Delivery Systems. Journal on nanotechnology online. March 2006. http://www.azonano.com/article.aspx?ArticleID=1538

Key words: polymers, drug delivery system, materials, nanotechnology

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Heart Risks and Hormones (HRT) in Menopause: Contradiction or Clarification?

Posted in Biomarkers & Medical Diagnostics, Bone Disease and Musculoskeletal Disease, CANCER BIOLOGY & Innovations in Cancer Therapy, Cell Biology, Signaling & Cell Circuits, Chemical Biology and its relations to Metabolic Disease, FDA Regulatory Affairs, Health Economics and Outcomes Research, Origins of Cardiovascular Disease, Pharmaceutical R&D Investment, Population Health Management, Genetics & Pharmaceutical, Population Health Management, Nutrition and Phytochemistry, Regulated Clinical Trials: Design, Methods, Components and IRB related issues, Reproductive Biology & Bio Instrumentation, tagged Brigham and Women's Hospital, Estrogen patch, Hormone therapy, North American Menopause Society, Progesterone, WHI on October 3, 2012| Leave a Comment »

Reporter: Aviva Lev-Ari, PhD, RN

Study Counters WHI on Heart Risk of Hormones in Menopause

By Crystal Phend, Senior Staff Writer, MedPage Today

Published: October 03, 2012

Hormone therapy may actually help the heart in some respects for newly menopausal women, a randomized trial showed, although the impact on hard outcomes like stroke and breast cancer still remains to be seen.

Oral estrogen plus progesterone improved lipid levels, while a transdermal patch improved insulin sensitivity in the KEEPS trial, according to researchers led by S. Mitchell Harman, MD, PhD, of the nonprofit Kronos Longevity Research Institute, which sponsored the trial.

Neither combination hormone treatment altered atherosclerosis progression or raised blood pressure, according to a Kronos press release summarizing a report to be presented Wednesday at the North American Menopause Society meeting in Orlando.

“The results provide reassurance for women who are recently menopausal and taking hormone therapy for short-term treatment of menopausal symptoms,” the group concluded in the release.

The need for reassurance stems from results released a decade ago from the Women’s Health Initiative (WHI), which showed an elevated risk of cardiovascular disease, stroke, and thromboembolic events as well as breast cancer with estrogen plus progestin.

Subsequent studies largely affirmed those risks and pointed to others, including ovarian cancer, lung cancer mortality, and probable dementia.

Menopause organizations largely recommended “the lowest dose for the shortest time” but have started backing away from that stance, instead endorsing a more flexible approach based on type and timing of hormone therapy.

Contradiction or Clarification?

The new study didn’t show significant differences in adverse events between women taking oral or transdermal estrogen with progesterone and those on placebo, including:

Breast cancer
Endometrial cancer
Myocardial infarction
Transient ischemic attack
Stroke
Venous thromboembolic disease

“However, the absolute numbers of such events were extremely small in all three treatment groups, making definitive conclusions impossible,” the researchers acknowledged.

Nor is the KEEPS study ever likely to definitively determine safety, because it was too small to assess clinical events, session moderator and presenter JoAnn E. Manson, MD, DrPH, commented in an email to ABC News and MedPage Today.

But that wasn’t the point of the trial, said Manson, who serves as chief of preventive medicine at Brigham and Women’s Hospital in Boston and is outgoing president of the menopause society.

“The KEEPS trial does not challenge the conclusions of WHI about the risks of clinical events with hormone therapy,” she wrote. “KEEPS and WHI were addressing entirely different questions.”

The earlier study tested hormone therapy as it was in clinical use at the time, for cardiovascular prevention based on epidemiologic suggestion of benefit.

The evidence has clearly come down against hormone therapy for that use, Manson noted.

The question that KEEPS is now answering is how perimenopausal women should approach management of menopausal symptoms — if relatively short periods of hormone therapy are safe, noted Sharonne N. Hayes MD, of the Women’s Heart Clinic at the Mayo Clinic in Rochester, Minn.

So it may be enough that these risks weren’t substantially elevated in the trial, several experts contacted by ABC and MedPage Today agreed.

“The safety of HRT in this newly menopausal population is very reassuring and will likely increase usage as well as demand for HRT in women suffering with vasomotor symptoms,” commented neurologist Cynthia L. Harden, MD, of the North Shore-Long Island Jewish Health System in Great Neck, N.Y., who said the KEEPS data adds nuance rather than contradiction.

The results don’t change the post-WHI clinical approach of yearly reassessment targeting discontinuation after a few years of hormone therapy, added Wendy Vitek, MD, an ob/gyn at the University of Rochester Medical Center in Rochester, N.Y.

Different Populations, Different Drugs

There were some differences between the Women’s Health Initiative and the KEEPS trial that may lead to real differences in outcome, though, researchers suggested.

The KEEPS trial included 727 healthy women ages 42 to 58 who were all within 3 years of the onset of menopause at baseline.

The mean age was 52, whereas the vast majority of women in the nine hormone therapy trials done to date, including the WHI, were in their 60s.

KEEPS randomized its newly-menopausal population to double-blind treatment with cyclical micronized progesterone (Prometrium) plus one of the following:

Oral conjugated equine estrogen (Premarin) given at 0.45 mg/day, which was lower than the 0.625 mg/d used in the WHI
Transdermal estradiol (Climara) at 50 µg/day, an option not available in the WHI
Placebo

Even the two different estrogen administration routes showed some differential effects on cardiovascular risk factors, the investigators pointed out.

HDL cholesterol and triglycerides rose while LDL fell with the oral estrogen.

The patch didn’t affect any lipid levels, but it did lower insulin resistance, which the oral form did not.

Neither drug boosted systolic or diastolic blood pressure, unlike the blood pressure increases seen with oral estrogen in the WHI.

Atherosclerosis neither accelerated nor reversed with 48 months of either treatment as monitored by carotid ultrasound, although there was a nonsignificant trend for less coronary artery calcium accumulation compared with placebo, noted Harman, who also practices at the Phoenix VA Medical System.

But that’s not necessarily reassuring with regard to cardiovascular outcomes for this younger group of women, Jacques Rossouw, MBChB, MD, chief of the WHI Branch of the National Heart, Lung and Blood Institute, noted in an email to ABC and MedPage Today.

“Changes in arteries in younger women have little relation to risk of stroke,” he explained. “Estrogen/progestin have [effects] on clotting mechanisms, on inflammation mechanisms. Those are things that trigger acute heart attack or stroke [in younger women]. Perfectly healthy young women can have strokes but have completely normal arteries. ”

Really, “the lack of effect on atherosclerosis reinforces the results of the WHI that hormone therapy is not good preventive therapy for heart disease,” added Lewis H. Kuller, MD, DrPH, of the University of Pittsburgh.

As expected, hormone therapy cut down on hot flashes and night sweats while raising bone density and mood, co-investigator Sanjay Asthana, MD, of the University of Wisconsin in Madison, said in the Kronos press release.

Sexual function also improved compared with placebo, in accord with the reduction in vaginal dryness although not the lack of improvement in sex drive seen in prior studies.

“KEEPS also highlights the need for individualized decision making about hormone therapy, given that oral conjugated equine estrogen and transdermal estradiol may have different profiles of effects, and different women have different symptom profiles and priorities for treatment,” the researchers noted in the press release.

KEEPS Sponsor Biased?

Kronos has long had an openly declared interest in countering the 2002 WHI findings of increased health risks from postmenopausal hormone therapy. In 2007, it issued a series of press releases attacking the WHI conclusions and touting KEEPS — one of which included a synopsis describing the nascent trial as “one of the studies to refute the WHI.”

The money behind Kronos comes from the Aurora Foundation. The latter was established by John Sperling, the billionaire founder of the University of Phoenix and other for-profit education ventures.

About 90% of Kronos’ $5.3 million in funding in 2010, the last year for which public records are available, came from Aurora. The $4.8 million given to Kronos that year was more than half of Aurora’s total giving.

Sperling, who is the foundation’s sole trustee, has a long history of involvement in sometimes controversial biological research involving life extension. He funded a successful, multimillion-dollar effort to clone his girlfriend’s dog in 2007, and later a similar cloning project for house cats.

Previously, he had bankrolled a medical clinic in a Phoenix suburb called the Kronos Group — not related to the Kronos Longevity Research Institute — that offered anti-aging remedies to older patients. It has since morphed into Kronos Optimal Health, which markets relatively conventional health and wellness programs to employers and individuals.

A 2004 article in Wired magazine reported that Sperling had also invested in a group of biotechnology companies seeking to develop anti-aging technologies based on cloning and stem cells.

The study was sponsored by the Kronos Longevity Research Institute with funding from the National Institutes of Health for the ancillary cognitive and affective portion.

The presentation was supported by grant funding from Noven Pharmaceuticals.

This article was developed in collaboration with ABC News.

Primary source: North American Menopause Society
Source reference:
Manson JE, et al “New findings from the Kronos early estrogen prevention study (keeps) Randomized trial” NAMS2012.

Crystal Phend

Staff Writer

Crystal Phend joined MedPage Today in 2006 after roaming conference halls for publications including The Medical Post, Oncology Times, Doctorâ€™s Guide, and the journal IDrugs. When not covering medical meetings, she writes from Silicon Valley, just south of the San Francisco fog.

SOURCE:

http://www.medpagetoday.com/MeetingCoverage/NAMS/35106?utm_source=breaking-news&utm_medium=email&utm_campaign=breaking-news

http://www.medpagetoday.com/OBGYN/HRT/32952

http://www.medpagetoday.com/OBGYN/HRT/31394

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