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Posts Tagged ‘alzheimer’s’


A Tribute to Johannes Everse

Author: Larry H Bernstein, MD, FCAP

 

Johannes Everse was a retired Tenured Professor at Texas Tech University Health Sciences Center in Lubbock, Texas, who dies on June 10, 2013.  He survived the Nazi invasion of Netherlands during World War II, and worked in the pharmaceutical industry after finishing a unique technical education the surpassed any that existed in United States that included an extensive knowledge of analytical instruments and expertise in organic chemical syntheses.  Given a unique opportunity, he applied for and obtained a position as a technician in the Laboratory of Nathan O Kaplan’s Laboratory at the time of Kaplan’s move from John’s Hopkins University to Brandeis University, where Kaplan with Sidney Colowick established the prestigious Methods in Enzymology series, and in a few short years built a worldclass Graduate Department of Biochemistry.  Kaplan was very sharp in selecting graduate students, postdoctoral students, and at administration, but his ability to recognioze potential talent was seen in his recruitment of Francis Stolzenbach and Johannes Everse.  He also gave considerable support to those who he had confidence in.  Consequently, Everse was able to take exams completing a BS degree, and eventually, the PhD degree at the University of California, San Diego, in the 1970s. When Prof. Kaplan was recruited to the UCSD campus by Martin Kamens, he was also installed in the National Academy of Sciences.

I worked with Jo Everse for several years as postdoctoral biochemist and resident-USPHS Fellow in  Pathology on the mechanism of the malate dehydrogenase (MDH) reaction and the regulatory function of the mitochondrial and cytoplasmic MDHs.   These were important formative years in my scientific training, and it was by no accident that I was sent to work in that laboratory by my previous mentor, a pathologist and biochemist who had worked on adenylate kinases, as I had been attracted to that problem as a medical student working on the ontogeny of the lactic dehydrogenases in the embryonic lens.  Jo Everse was responsible for synthesizing the pyridine nucleotide adducts that proved to be critical to understanding the pyridine nucleotide related dehydrogenase reactions.  Jo was undoubtedly a driving force in that laboratory.

It was at that time that my first daughter was born, and she had the opportunity to play with the Everse children, who as adults are both PhD biochemists.  I have been fortunate to live through a dynamic period in the history of scientific discovery, and most amazingly, at a time of decline in funding for science that has not been deterred since the Vietnam War.  You may consider it the cost of hegemony after the treaty that ended WWII and brought us the cold war.

Jo went on to a tenured faculty position at TTUHSS, and his retirement came shortly before his death at 80. While he stayed longer than his superiors wanted, his welcome was not so warm after he criticized the administration of the graduate program.  Unfortunately, he did not have the kind of backing that a colleague at Berkeley, Howard Schachman, Professor of the Graduate School Division of Biochemistry, Biophysics and Structural Biology, enjoyed.  It should not be a surprise how good health, power and money makes a difference in how it plays out.

Schachman was asked to retire in 2002 having a busy, well-funded study, that involved allostery and precisely – in the structure, function, assembly and interactions of biological macromolecules, with particular emphasis on the regulatory enzyme, aspartate transcarbamylase (ATCase).  The studies challenged earlier studies that designated the complex of ATCase with a bisubstrate ligand as the R state of the enzyme. but changes in the conformation were reinterpreted to be the result of the actual binding event rather than the allosteric transition whereby the enzyme is converted from an inactive, taut (T) state to the activated R conformation and they developed methods for understanding the formation of domains and the effect of deletions of helical regions on stability and the folding and assembly pathways.

Jo Everse came out of the depression in Europe (1931 birth), lived through WWII, and he managed to get a unique technical education that took him to Boston.  He became an excellent teacher.  He had a good marriage and father of two children.  He collected Packard automobiles and rebuilt them.  He also played the organ, and he made and maintained an organ for his home.  He lived a good life.

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Larry H Bernstein, MD, FCAP, reporter and curator

htto://pharmaceuticalintelligence.com/2013-12-07/larryhbern/Advances-in-Stem-Cell-Research

The amount of success in stem cell research and recent successes is notable.

GEN News  Dec 5, 2013
Stem Cell Leaders Call for Human Embryome Project

Just as an international consortium was formed to map and sequence the human genome, now a group of stem cell and regenerative medicine scientists say it’s critical that such an effort be ramped up to do a similar project focused on the human embryome.

This was the key message of a panel discussion, “From Mapping the Genome to Mapping the Embryome: The Urgent Need for an International Initiative,” moderated by Michael West, Ph.D., CEO of Biotime. It took place at the World Stem Cell Summit, which is taking place this week in San Diego.

“It is becoming increasingly clear in regenerative medicine that pluripotent stem cells, embryonic stem cells, and IPs cells will be as fundamentally important to medicine as was DNA. Maybe even bigger because you can genetically engineer these cells,” said Dr. West.

Dr. West and his colleagues adamantly believe that there needs to be a large international effort aimed at mapping the cellular and molecular basis of all human life starting with the fertilized egg and working its way up to the body of the adult. This is what it is termed the embryome.

“The opportunity presented by pluripotent stem cells to manufacture for the first time in the history of medicine all of the cellular components of the human body on an industrial scale is at once both an opportunity and a challenge,” said Dr. West. “The opportunity is to build a new field we call regenerative medicine in which many currently incurable diseases are treated with cells capable of regenerating tissues afflicted with disease. The challenge relates to the complexity of the cell types in the body and our ability to manufacture products with precisely defined compositions for human clinical use.”

Dr. West went on to say that to get these different types of stem cells into the clinic, and approved by the FDA, researchers will fully need to understand all aspects of the biology of these cells. An identification and understanding of any contaminating cells will also be essential to success in this field. The question to ask is “What is in the syringe?”

Unlike recombinant DNA, continued Dr. West, the contaminants in pluripotent stem cells are alive and may make things that are undesirable at the intended point of therapy. For example, you might have a bioreactor full of cells that are making heart muscle to regenerate heart function in a patient. But you have to be careful that your cells are not contaminated with neural crest cells from the head area which could generate a tooth along with the heart muscle.

“These contaminants, if you do not remove them, can lead to years of delay in filing an IND and a runup in costs as you try to identify these cells,” explained Dr. West.

The major problem in identifying them, according to Dr. West, is that no one has ever mapped the molecular markers or even a rudimentary cell ontology tree, i.e., mapped out the tree from the fertilized egg to the cells of the human body.

“If [there were] a detailed map of all the cellular and molecular components of life from the fertilized egg to adulthood, and then databased in a manner to the information in the human genome, medicine would be the true beneficiary,” added Dr. West. “That’s why we have made this call for an international initiative.”

Also, watch our video “A Brief History of Stem Cells” to see a timeline spanning over 60 years of stem cell research.

Mary Ann Liebert Wins Stem Cell Education Award

Mary Ann Liebert, president and CEO of Mary Ann Liebert Inc., and publisher of GEN, was presented with the Stem Cell Education Award by the Genetics Policy Institute. The award was given during a ceremony at dinner which took place at the World Stem Cell Summit, which is being held in San Diego this week.

Liebert was cited for her outstanding “work in educating patients, researchers, and the broader stem cell community, and in raising the standard in medical research journalism.” Among the seventy journals the Liebert company publishes is the peer-reviewed Stem Cells and Development.

In her acceptance speech Liebert told the audience that she was extremely gratified in being so recognized and thanked the entire staff at her company for their dedication in helping to promote excellence in medical publishing.

In his introductory remarks during the award ceremony GEN’s long-time editor in chief John Sterling noted that Mary Ann always encourages her editors and writers “to inform, enlighten when they can, and educate as much as possible.”

Sterling added that while she started her company 33 years ago her vision for her publications remains the same: “to help advance our knowledge of science and medicine in the best ways possible.”

 

Neural Precursors “Cure MS” in Mice

During a session at the this week’s World Stem Cell Summit in San Diego, an international research team described an “astonishing” experiment in which a mouse model of multiple sclerosis was able to virtually totally recover and move normally after being transplanted with human neural precursor cells (hNPC). The scientists were able to show almost full recovery in the mice up to six months later.

The investigators, led by Jeanne Loring, Ph.D., from the Scripps Research Institute, included scientists from the University of California, Irvine and a group from Australia.

“Our goal was to demonstrate cell therapy for MS,” Dr. Loring told the audience.

According to Ronald Coleman, a graduate student working with Dr. Loring and who is at UC-Irvine, the team used mice infected with a neurotropic JHM variant of mouse hepatitis virus (JHMV) as a model for MS. They injected hNPCs derived from human pluripotent stem cells (hPSC) into the mice to explore treatment options for the disease.

The results were indeed astonishing, said Dr. Loring. Non-control mice were able to move about in a manner that can be described as consistent and long lasting. T-cell proliferation was reduced and T regulatory cell induction took place. The spinal cords of the mice not only did not undergo further demyelination but actually exhibited remyelination. The control mice dragged their legs around when they tried to move.

“The only problem was that the hNPCs themselves are not directly responsible for the cure. They are not even there when the mice start walking,” explained Dr. Loring. “Those cells are rejected after seven days and we start to see a therapeutic response in three weeks.”

Both Dr. Loring and Coleman believe that the hNPCs are secreting proteins, like cytokines, that do the actual repair work in the CNS of the mice.

“We identified a set of candidate proteins secreted by hNPCs and not by undifferentiated pluripotent stem cells,” continued Dr. Loring, who said the team plans to continue building on this initial research.

 

World Stem Cell Summit: December 4, 2013 Update

GEN is on the scene at the World Stem Cell Summit in San Diego. Here are some highlights from the conference so far:

Bernard Siegel, J.D., founder and co-chair of the World Stem Cell Summit (WSCS) and executive director of Genetics Policy Institute, today welcomed attendees of WSCS 2013, being held December 4–6, in San Diego, CA.

“Stem cell science represents, to those afflicted with chronic disease, a vehicle for modeling disease and therapeutic development,” states Siegel in World Stem Cell Report 2013, a supplement to Stem Cells and Development (2013;22;Suppl1). “The field is a true scientific revolution and reflects the transformative power of hope, a powerful engine for progress.”

“The future is here now,” says Mahendra Rao, M.D., Ph.D., director, NIH Center for Regenerative Medicine, who delivered a plenary keynote and moderated the plenary panel discussion, “How Stem Cells are Transforming Medicine.” Cell therapies have been used to treat people safely and effectively; the technical barriers have been addressed. The challenge now is to reduce the cost of manufacturing. To drive routine adoption of cell therapy it must be cost effective and must demonstrate more than incremental benefit, according to Dr. Rao.

Professor Teruo Okano, Ph.D., Tokyo Women’s Medical University, described his group’s Cell Sheet Tissue Engineering strategy that involves enzymatic membrane disruption during cell harvesting and growth of an autologous cell sheet for transplantation on an “intelligent surface” that reversibly changes properties from hydrophobic to hydrophilic with a reversible in temperature from 37°C to 20°C. Dr. Okano further described the development of an automatic tissue factory and thick tissue evaluation system for fully automated, industrialized GMP cell processing.

Andre Terzic, M.D., Ph.D., Center for Regenerative Medicine, Mayo Clinic, noted during the opening session of the WSCS that “the Mayo Clinic has embraced regenerative medicine as a strategy for the future of medicine,” and he described their blueprint for moving from knowledge to delivery of treatments and procedures. Education is a critical dimension of this process. Another important component, according to Dr. Terzic, is the Regenerative Medicine Biotrust, in which “the patient is the center of the solution” to develop combinations of diagnostics and therapeutics and conduct clinical trials.

Regardless of the outcomes of current or future clinical trials, “I would argue that we have already seen breakthroughs,” said Evan Snyder, Ph.D., Sanford-Burnham Medical Research Institute, as stem cells “have completely changed the way medicine thinks about disease and development.” They have led to new views on plasticity and regeneration and the development of different types of drug targets.

WSCS 2013 is organized by the Genetics Policy Institute (GPI), California Institute for Regenerative Medicine (CIRM), Institute for Integrated Cell-Material Sciences at Kyoto University (iCeMS), Mayo Clinic, Sanford-Burnham Medical Research Institute, and The Scripps Research Institute. Mary Ann Liebert, Inc. publishers and Genetic Engineering & Biotechnology News (GEN) are sponsors of the summit.

Drug Testing Should Be with Human iPS Cells
Fri, 12/06/2013 – drug discovery & development  (DDD)

Once established such neural stem cells can be used to continuously generate neurons for drug testing and disease modeling. Depicted is an immunofluorescence staining where proteins characteristic of neural stem cells are labeled with fluorescing antibodies (Nestin in green, Dach1 in red). (Source: Jerome Mertens / Uni Bonn)Once established such neural stem cells can be used to continuously generate neurons for drug testing and disease modeling. Depicted is an immunofluorescence staining where proteins characteristic of neural stem cells are labeled with fluorescing antibodies (Nestin in green, Dach1 in red). (Source: Jerome Mertens / Uni Bonn)Why do certain Alzheimer medications work in animal models but not in clinical trials in humans? A research team from the University of Bonn and the biomedical enterprise Life & Brain GmbH has been able to show that results of established test methods with animal models and cell lines used up until now can hardly be translated to the processes in the human brain. Drug testing should therefore be conducted with human nerve cells, conclude the scientists. The results are published by Cell Press in the journal Stem Cell Reports.

In the brains of Alzheimer’s patients, deposits form that consist essentially of beta-amyloid and are harmful to nerve cells. Scientists are therefore searching for pharmaceutical compounds that prevent the formation of these dangerous aggregates. In animal models, certain non-steroidal anti-inflammatory drugs (NSAIDs) were found to a reduced formation of harmful beta-amyloid variants. Yet, in subsequent clinical studies, these NSAIDs failed to elicit any beneficial effects.

“The reasons for these negative results have remained unclear for a long time”, said Oliver Brüstle, director of the Institute for Reconstructive Neurobiology of the University of Bonn and CEO of Life & Brain GmbH. “Remarkably, these compounds were never tested directly on the actual target cells—the human neuron”, added lead author Jerome Mertens of Brüstle’s team, who now works at the Laboratory of Genetics in La Jolla (USA). This is because, so far, living human neurons have been extremely difficult to obtain. However, with the recent advances in stem cell research it has become possible to derive limitless numbers of brain cells from a small skin biopsy or other adult cell types.

Scientists transform skin cells into nerve cells

Now a research team from the Institute for Reconstructive Neurobiology and the Department of Neurology of the Bonn University Medical Center together with colleagues from the Life & Brain GmbH and the University of Leuven (Belgium) has obtained such nerve cells from humans. The researchers used skin cells from two patients with a familial form of Alzheimer’s Disease to produce so-called induced pluripotent stem cells (iPS cells), by reprogramming the body’s cells into a quasi-embryonic stage. They then transformed the resulting iPS cells into nerve cells.

Using these human neurons, the scientists tested several compounds in the group of NSAIDs. As control, the researchers used nerve cells they had obtained from iPS cells of donors who did not have the disease. Both in the nerve cells obtained from the Alzheimer’s patients and in the control cells, the NSAIDs that had previously tested positive in the animal models and cell lines typically used for drug screening had practically no effect: The values for the harmful beta-amyloid variants that form the feared aggregates in the brain remained unaffected when the cells were treated with clinically relevant dosages of these compounds.

Metabolic processes in animal models differ from humans

“In order to predict the efficacy of Alzheimer drugs, such tests have to be performed directly on the affected human nerve cells”, concluded Brüstle’s colleague Philipp Koch, who led the study. Why do NSAIDs decrease the risk of aggregate formation in animal experiments and cell lines but not in human neurons? The scientists explain this with differences in metabolic processes between these different cell types. “The results are simply not transferable”, says Koch.

The scientists now hope that in the future, testing of potential drugs for the treatment of Alzheimer’s disease will be increasingly conducted using neurons obtained from iPS cells of patients. “The development of a single drug takes an average of ten years”, said Brüstle. “By using patient-specific nerve cells as a test system, investments by pharmaceutical companies and the tedious search for urgently needed Alzheimer medications could be greatly streamlined”.

Date: November 6, 2013
Source: University of Bonn

 

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Curated by: Dr. Venkat S. Karra, Ph.D.

A human brain showing frontotemporal lobar deg...

The number of patients with dementia have been increasing exponentially with the aging of society.  The development of AD research has clarified that the pathogenesis of AD is initiated by amyloidosis with secondary tauopathy and provided a strategy for investigating drugs that may improve or cure AD.

Mild cognitive impairment (MCI) as a prodromal stage of AD and the pathogenesis of Dementia with Lewy bodies (DLB) and Frontotemporal lobar degeneration (FTLD) as a non-AD type dementia have also been elucidated. Currently, a consortium study by the Alzheimer Disease Neuroimaging initiative (ADNI) is being performed to establish global clinical evidence regarding a neuropsychiatric test battery, CSF biomarkers, neuroimaging including MRI, FDG-PET, and amyloid PET to predict progression from MCI to AD and to promote studies of basic therapy for AD [1].

Several new biomarkers such as Aβ oligomer, α-synuclein, and TDP-43 are now under investigation for further determination of their usefulness to detect AD and other non-AD type dementia.

Cerebrospinal Fluid Aβ40, Aβ42, Tau, and Phosphorylated Tau biomarkers have been used for a clinical diagnosis of AD, discrimination from the Vascular dementia (VaD) and non-AD type dementia, exclusion of treatable dementia and MCI, prediction of AD onset and evaluation of the clinical trials of an anti-Aβ antibody, Aβ vaccine therapy, and secretase inhibitors [2–4].

In the current study Schoonenboom et al., [10] conducted a large cohort of patients with different types of dementia to determine how amyloid β 42 (Aβ42), total tau (t-tau), and phosphorylated tau (p-tau) levels behave in CSF.

Aβ is produced mainly in the nerve cells of the brain, and it is secreted about 12 hours later into the CSF, then excreted through the blood-brain barrier 24 hours later into blood (Aβ clearance), and finally degraded in the reticuloendothelial system. Aβ levels are regulated in strict equilibrium among the brain, CSF, and blood [6, 7]. Aβ levels are high while awake and low while a sleep suggesting the presence of a daily change in the CSF Aβ amounts and it is because Aβ amounts in CSF are controlled by orexin and thus collection of CSF by lumbar puncture early in morning in a fasting state is recommended [5].

In AD brains, Aβ42 forms insoluble amyloids and accumulates as insoluble amyloid fibrils in the brain. The reason Aβ42 levels are decreased in the CSF of AD patients is considered to be caused by deterioration of physiologic Aβ clearance into the CSF in AD brains [2, 3]. CSF total tau levels increase slightly with aging. However, CSF tau levels show a 3-fold greater increase in AD patients than in normal controls [8].

It is thought that the rise in CSF total tau is related to degeneration of axons and neurons and to severe destructive disease of the nervous system. Several diseases show slightly increased tau levels such as VaD, multiple sclerosis, AIDS dementia, head injury, and tauopathy. However, CSF tau levels show significant increases in Creutzfeldt-Jakob disease (CJD) and meningoencephalitis [8].

These biomarkers can be measured with an Amyloid ELISA Kit (Wako), which is commercially available and used worldwide. The ELISA kit was developed in Japan by Suzuki et al. and shows extremely high sensitivity and reproducibility [9]. INNOTEST β-AMYLOID1-42 (Innogenetics), for Aβ42 is used widely in Europe and America.

Several assay kits for total tau and phosphorylated tau are also used for the measurement of CSF tau. Currently, total tau is measured using INNOTEST hTau Ag (Innogenetics). There are 3 ELISA systems for measurement of phosphorylated tau that recognize the special phosphorylation sites at Ser199 (Mitsubishi Chemical Corp.), Thr181 (Innogenetics) and Thr231 (Applied NeuroSolutions Inc.), and phosphorylated tau levels are increased in CSF of AD on assays using these kits. Of these 3 kits, INNOTEST PHOSPHO-TAU (181) (Innogenetics) is commercially available and used widely. Recently, INNO-BIA AlzBio3 by Innogenetics has been able to measure Aβ1-42, total tau, and P-tau181P simultaneously in 75 μL of CSF, which is a very small amount of CSF.

In the current study researchers used the following strategy to collect Baseline CSF and Aβ42, t-tau, and p-tau (at amino acid 181) were measured in CSF by ELISA:

Types of patients with Alzheimer disease (AD) = 512 patients
Types of patients with other types of dementia (OD) = 272 patients
Types of patients with a psychiatric disorder (PSY) = 135 patients
Types of patients with subjective memory complaints (SMC) = 275 patients
Autopsy was obtained in a subgroup of about 17 patients.

The study suggested that CSF Aβ42, t-tau, and p-tau are useful in differential dementia diagnosis, whereas in DLB, FTLD, VaD, and CBD, a substantial group exhibited a CSF AD biomarker profile, which requires more autopsy confirmation in the future.

The study found a correct classification of patients with AD (92%) and patients with OD (66%)  when CSF Aβ42 and p-tau were combined.
Patients with progressive supranuclear palsy had normal CSF biomarker values in 90%.

Patients with Creutzfeldt-Jakob disease demonstrated an extremely high CSF t-tau at a relatively normal CSF p-tau.

CSF AD biomarker profile was seen in

47% of patients with dementia with Lewy bodies (DLB),

38% in corticobasal degeneration (CBD), and

30% in frontotemporal lobar degeneration (FTLD) and vascular dementia (VaD).

PSY and SMC patients had normal CSF biomarkers in 91% and 88%.

Older patients are more likely to have a CSF AD profile.

Concordance between clinical and neuropathologic diagnosis was 85%.

CSF markers reflected neuropathology in 94%.

The study concluded that CSF Aβ42, t-tau, and p-tau are useful in differential dementia diagnosis. However, in DLB, FTLD, VaD, and CBD, a substantial group exhibit a CSF AD biomarker profile, which requires more autopsy confirmation in the future.

References:

1. R. C. Petersen, P. S. Aisen, L. A. Beckett et al., “Alzheimer’s Disease Neuroimaging Initiative (ADNI): clinical characterization,” Neurology, vol. 74, no. 3, pp. 201–209, 2010.

2. M. Shoji and M. Kanai, “Cerebrospinal fluid Aβ40 and Aβ42: natural course and clinical usefulness,” Journal of Alzheimer’s Disease, vol. 3, no. 3, pp. 313–321, 2001.

3. M. Shoji, M. Kanai, E. Matsubara et al., “The levels of cerebrospinal fluid Aβ40 and Aβ42(43) are regulated age-dependently,” Neurobiology of Aging, vol. 22, no. 2, pp. 209–215, 2001.

4. M. Kanai, E. Matsubara, K. Isoe et al., “Longitudinal study of cerebrospinal fluid levels of tau, Aβ1-40, and Aβ1-42(43) in Alzheimer’s disease: a study in Japan,” Annals of Neurology, vol. 44, no. 1, pp. 17–26, 1998.

5. J. E. Kang, M. M. Lim, R. J. Bateman et al., “Amyloid-β dynamics are regulated by orexin and the sleep-wake cycle,” Science, vol. 326, no. 5955, pp. 1005–1007, 2009.

6. M. Shoji, T. E. Golde, J. Ghiso et al., “Production of the Alzheimer amyloid β protein by normal proteolytic processing,” Science, vol. 258, no. 5079, pp. 126–129, 1992.

7. R. J. Bateman, E. R. Siemers, K. G. Mawuenyega et al., “A γ-secretase inhibitor decreases amyloid-β production in the central nervous system,” Annals of Neurology, vol. 66, no. 1, pp. 48–54, 2009.

8. M. Shoji, E. Matsubara, T. Murakami et al., “Cerebrospinal fluid tau in dementia disorders: a large scale multicenter study by a Japanese study group,” Neurobiology of Aging, vol. 23, no. 3, pp. 363–370, 2002.

9. N. Suzuki, T. T. Cheung, X. D. Cai et al., “An increased percentage of long amyloid β protein secreted by familial amyloid β protein precursor (βAPP) mutants,” Science, vol. 264, no. 5163, pp. 1336–1340, 1994.

Source:

10. N.S.M. Schoonenboom et al., Cerebrospinal fluid markers for differential dementia diagnosis in a large memory clinic cohort

For further insight read the following excellent review article by M. Shoji

Biomarkers of Dementia

Special thanks to Wikipedia for excellent relevant pictures and keyword links.

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