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Posts Tagged ‘University of California San Diego’


Reporter: Aviva Lev-Ari, PhD, RN

 

A New Protein Target for Controlling Diabetes

Researchers at the University of California, San Diego School of Medicine have identified a previously unknown biological mechanism involved in the regulation of pancreatic islet beta cells, whose role is to produce and release insulin. The discovery suggests a new therapeutic target for treating dysfunctional beta cells and type 2 diabetes, a disease affecting more than 25 million Americans.

Writing in the April 11, 2013 issue of Cell, Jerrold M. Olefsky, MD, associate dean for scientific affairs and distinguished professor of medicine, and colleagues say a transmembrane binding protein called fractalkine, which typically mediates cell-to-cell adhesion though its receptor, CX3CR1, can also be released from cells to circulate in the blood and stimulate insulin secretion.

“Our discovery of fractalkine’s role in beta cells is novel and has never been talked about in prior literature,” said Olefsky. More importantly, the research highlights fractalkine’s apparently vital role in normal, healthy beta cell function. In mouse models and in cultured human islets, the researchers found administering the protein stimulated insulin secretion and improved glucose tolerance, both key factors in diabetes.  In contrast, fractalkine had no effect in mice or islets when the fractalkine receptor was deleted.

“Whether or not decreased fractalkine or impaired fractalkine signaling are causes of decreased beta cell function in diabetes is unknown,” said Olefsky. “What we do know, without doubt, is that administration of fractalkine improves or restores insulin secretion in all of the mouse models we have examined, as well as in human islet cells.”

Olefsky said fractalkine or a protein analog could prove “a potential treatment to improve insulin secretion in type 2 diabetic patients. It might also improve beta cell function or beta cell health, beyond simply increasing insulin secretion, since fractalkine prevents beta cell apoptosis (cell death) and promotes the beta cell differentiation program.

“If successfully developed, this could be an important new complement to the therapeutic arsenal we use in type 2 diabetes,” Olefsky continued. “It is not likely to ‘cure’ diabetes, but it would certainly do a good job at providing glycemic control.”

Co-authors of this study include Yun Sok Lee, Hidetaka Morinaga, and William Lagakos, UCSD Department of Medicine, Division of Endocrinology and Metabolism; Jane J. Kim and Ayse G. Kayali, UCSD Department of Pediatrics; Susan Taylor and Malik Keshwani, UCSD Department of Pharmacology; Guy Perkins, National Center for Microscopy and Imaging Research at UCSD; Hui Dong, UCSD Department of Medicine, Division of Gastroenterology; and Ian R. Sweet, Department of Medicine, University of Washington.

Funding came, in part, from the National Institutes of Health (grants DK-033651, DK-074868, T32-DK-007494 and DK-063491) and the Eunice Kennedy Shriver National Institute of Child Health and Human Development/NIH (U54-HD-012303-25).

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Arteriogenesis and Cardiac Repair: Two Biomaterials – Injectable Thymosin beta4 and Myocardial Matrix Hydrogel

Curator: Aviva Lev-Ari, PhD, RN

 

Thymosin beta 4 (Tβ4)

is a highly conserved, 43-amino acid acidic peptide (pI 4.6) that was first isolated from bovine thymus tissue over 25 years ago. It is present in most tissues and cell lines and is found in high concentrations in blood platelets, neutrophils, macrophages, and other lymphoid tissues. Tβ4 has numerous physiological functions, the most prominent of which being the regulation of actin polymerization in mammalian nucleated cells and with subsequent effects on actin cytoskeletal organization, necessary for cell motility, organogenesis, and other important cellular events.

Recently,

  • Tβ4 was shown to be expressed in the developing heart and found to stimulate migration of cardiomyocytes and endothelial cells, promote survival of cardiomyocytes (Nature, 2004), and most recently
  • to play an essential role in all key stages of cardiac vessel development: vasculogenesis, angiogenesis, and arteriogenesis (Nature 2006).

These results suggest that Tβ4 may have significant therapeutic potential in humans to protect myocardium and promote cardiomyocyte survival in the acute stages of ischemic heart disease.

RegeneRx Biopharmaceuticals, Inc. is developing Tβ4 for the treatment of patients with acute myocardial infarction (AMI). Such efforts presented will include the formulation, development, and manufacture of a suitable drug product for use in the clinic, the performance of nonclinical pharmacology and toxicology studies, and the implementation of a phase 1 clinical protocol to assess the safety, tolerability, and the pharmacokinetics of Tβ4 in healthy volunteers.

 

SOURCE:
EXPLORATIONS with THYMOSIN beta4 FOR INDUCING ADULT EPICARDIAL PROGENETOR MOBILIZATION AND NEOVASCULARIZATION is presented in
Resident-cell-based Therapy in Human Ischaemic Heart Disease: Evolution in the PROMISE of Thymosin beta4 for Cardiac Repair

https://pharmaceuticalintelligence.com/2012/04/30/93/

Clinical Study Data of Thymosin beta 4 Presented

Published on October 3, 2009 at 5:10 AM

REGENERX BIOPHARMACEUTICALS, INC. (NYSE Amex:RGN) today reported on several clinical studies with Thymosin beta 4 (Tβ4) presented the Second International Symposium on Thymosins in Health and Disease, in Catania, Italy. The following are synopses of the presentations:

Myocardial Development of RGN-352 (Injectable Tβ4 Peptide)

David Crockford, RegeneRx’s vice president for clinical and regulatory affairs presented an overview of the biological properties that support Tβ4’s near term and long term clinical applications. Mr. Crockford noted that special emphasis is being placed on the development of RGN-352 for the systemic (injectable) treatment of patients with ST-elevation myocardial infarction (STEMI) in combination with percutaneous coronary intervention, the current standard of care in most western countries for this common type of heart attack. The goal with RGN-352 is to prevent or repair continued damage to cardiac tissue post-heart attack, when such tissue around the damaged site remains at risk.

Dr. Dennis Ruff, vice president and medical director of ICON, and principal investigator, presented the most current results on the Phase I safety study with RGN-352 entitled, “A Randomized, Double-blind, Placebo-controlled, Dose-response Phase I Study of the Safety and Tolerability of the Intravenous Administration of Thymosin Beta 4 and its Pharmacokinetics After Single and Multiple Doses in Healthy Volunteers.” Dr. Ruff discussed key aspects of the study and concluded with, “There were no dose limiting or serious adverse events throughout the dosing period. Synthetic Tβ4 administered intravenously up to 1260 mg, and for up to 14 days, appears to be well tolerated with low incidence of adverse events and no evidence of serious adverse events.”

http://www.news-medical.net/news/20091003/Clinical-study-data-of-Thymosin-beta-4-presented.aspx

RegeneRx Receives Notice of Allowance from Chinese Patent Office for Treatment and Prevention of Heart Disease

RegeneRx Receives Notice of Allowance from Chinese Patent Office for Treatment and Prevention of Heart Disease

February 7, 2013 — Rockville, Md.

RegeneRx Biopharmaceuticals, Inc. (OTC Bulletin Board: RGRX) (“the Company” or “RegeneRx”) today announced that it has received a Notice of Allowance of a Chinese patent application for uses of Thymosin beta 4 (TB4) for treating, preventing, inhibiting or reducing heart tissue deterioration, injury or damage in a subject with heart failure disease. Claims also include uses for restoring heart tissue in those subjects. The patent will expire July 26, 2026.

http://www.regenerx.com/wt/page/pr_1360265259

Active Research on Thymosins in Cardiovascular Disease Reported in 2010 and 2012 Annual Conference on Thymosins, Proceedings by NY Academy of Sciences

Use of the cardioprotectants thymosin β4 and dexrazoxane during congenital heart surgery: proposal for a randomized, double-blind, clinical trial

Neonates and infants undergoing heart surgery with cardioplegic arrest experience both inflammation and myocardial ischemia-reperfusion (IR) injury. These processes provoke myocardial apoptosis and oxygen-free radical formation that result in cardiac injury and dysfunction. Thymosin β4 (Tβ4) is a naturally occurring peptide that has cardioprotective and antiapoptotic effects. Similarly, dexrazoxane provides cardioprotection by reduction of toxic reactive oxygen species (ROS) and suppression of apoptosis. We propose a pilot pharmacokinetic/safety trial of Tβ4 and dexrazoxane in children less than one year of age, followed by a randomized, double-blind, clinical trial of Tβ4 or dexrazoxane versus placebo during congenital heart surgery. We will evaluate postoperative time to resolution of organ failure, development of low cardiac output syndrome, length of cardiac ICU and hospital stays, and echocardiographic indices of cardiac dysfunction. Results could establish the clinical utility of Tβ4 and/or dexrazoxane in ameliorating ischemia-reperfusion injury during congenital heart surgery.[1]

Cardiac repair with thymosin β4 and cardiac reprogramming factors

Heart disease is a leading cause of death in newborns and in adults. We previously reported that the G-actin–sequestering peptide thymosin β4 promotes myocardial survival in hypoxia and promotes neoangiogenesis, resulting in cardiac repair after injury. More recently, we showed that reprogramming of cardiac fibroblasts to cardiomyocyte-like cells in vivo after coronary artery ligation using three cardiac transcription factors (Gata4/Mef2c/Tbx5) offers an alternative approach to regenerate heart muscle. We have combined the delivery of thymosin β4 and the cardiac reprogramming factors to further enhance the degree of cardiac repair and improvement in cardiac function after myocardial infarction. These findings suggest that thymosin β4 and cardiac reprogramming technology may synergistically limit damage to the heart and promote cardiac regeneration through the stimulation of endogenous cells within the heart.[2]

NMR structural studies of thymosin α1 and β-thymosins

Thymosin proteins, originally isolated from fractionation of thymus tissue, represent a class of compounds that we now know are present in numerous other tissues, are unrelated to each other in a genetic sense, and appear to have different functions within the cell. Thymosin α1 (generic drug name thymalfasin; trade name Zadaxin) is derived from a precursor molecule, prothymosin, by proteolytic cleavage, and stimulates the immune system. Although the peptide is natively unstructured in aqueous solution, the helical structure has been observed in the presence of trifluoroethanol or unilamellar vesicles, and these studies are consistent with the presence of a dynamic helical structure whose sides are not completely hydrophilic or hydrophobic. This helical structure may occur in circulation when the peptide comes into contact with membranes. In this report, we discuss the current knowledge of the thymosin α1 structure and similar properties of thymosin β4 and thymosin β9, in different environments.[3]

Thymosin β4 sustained release from poly (lactide-co-glycolide) microspheres: synthesis and implications for treatment of myocardial ischemia

 A sustained release formulation for the therapeutic peptide thymosin β4 (Tβ4) that can be localized to the heart and reduce the concentration and frequency of dose is being explored as a means to improve its delivery in humans. This review contains concepts involved in the delivery of peptides to the heart and the synthesis of polymer microspheres for the sustained release of peptides, including Tβ4. Initial results of poly(lactic-co-glycolic acid) microspheres synthesized with specific tolerances for intramyocardial injection that demonstrate the encapsulation and release of Tβ4 from double-emulsion microspheres are also presented.[4]
Thymosin β4 and cardiac repair
Hypoxic heart disease is a predominant cause of disability and death worldwide. As adult mammals are incapable of cardiac repair after infarction, the discovery of effective methods to achieve myocardial and vascular regeneration is crucial. Efforts to use stem cells to repopulate damaged tissue are currently limited by technical considerations and restricted cell potential. We discovered that the small, secreted peptide thymosin β4 (Tβ4) could be sufficiently used to inhibit myocardial cell death, stimulate vessel growth, and activate endogenous cardiac progenitors by reminding the adult heart on its embryonic program in vivo. The initiation of epicardial thickening accompanied by increase of myocardial and epicardial progenitors with or without infarction indicate that the reactivation process is independent of injury. Our results demonstrate Tβ4 to be the first known molecule able to initiate simultaneous myocardial and vascular regeneration after systemic administration in vivo. Given our findings, the utility of Tβ4 to heal cardiac injury may hold promise and warrant further investigation.[7]
Thymosin β4 facilitates epicardial neovascularization of the injured adult heart
Ischemic heart disease complicated by coronary artery occlusion causes myocardial infarction (MI), which is the major cause of morbidity and mortality in humans (http://www.who.int/cardiovascular_diseases/resources/atlas/en/index.html). After MI the human heart has an impaired capacity to regenerate and, despite the high prevalence of cardiovascular disease worldwide, there is currently only limited insight into how to stimulate repair of the injured adult heart from its component parts. Efficient cardiac regeneration requires the replacement of lost cardiomyocytes, formation of new coronary blood vessels, and appropriate modulation of inflammation to prevent maladaptive remodeling, fibrosis/scarring, and consequent cardiac dysfunction. Here we show that thymosin β4 (Tβ4) promotes new vasculature in both the intact and injured mammalian heart. We demonstrate that limited EPDC-derived endothelial-restricted neovascularization constitutes suboptimal “endogenous repair,” following injury, which is significantly augmented by Tβ4 to increase and stabilize the vascular plexus via collateral vessel growth. As such, we identify Tβ4 as a facilitator of cardiac neovascularization and highlight adult EPDCs as resident progenitors which, when instructed by Tβ4, have the capacity to sustain the myocardium after ischemic damage.[8]
Thymosin β4 enhances repair by organizing connective tissue and preventing the appearance of myofibroblasts
Incisional wounds in rats treated locally with thymosin β4 (Tβ4) healed with minimal scaring and without loss in wound breaking strength. Treated wounds were significantly narrower in width. Polarized light microscopy treated wounds had superior organized collagen fibers, displaying a red birefringence, which is consistent with mature connective tissue. Control incisions had randomly organized collagen fibers, displaying green birefringence that is consistent with immature connective tissue. Immunohistology treated wounds had few myofibroblasts and fibroblasts with α smooth muscle actin (SMA) stained stress fibers. Polyvinyl alcohol sponge implants placed in subcutaneous pockets received either carrier or 100 μg of Tβ4 on days 2, 3, and 4. On day 14, treated implants revealed longer, thicker collagen fiber bundles with intense yellow-red birefringence by polarized light microscopy. In controls, fine, thin collagen fiber bundles were arranged in random arrays with predominantly green birefringence. Controls contained mostly myofibroblasts, while few myofibroblasts appeared in Tβ4 treated implants. Electron microscopy confirmed both cell types and the degree of collagen fiber bundle organization. Our results demonstrate that Tβ4 treated wounds appear to mature earlier and heal with minimal scaring.[9]
Thymosin β4: a key factor for protective effects of eEPCs in acute and chronic ischemia
Acute myocardial infarction is still one of the leading causes of death in the industrial nations. Even after successful revascularization, myocardial ischemia results in a loss of cardiomyocytes and scar formation. Embryonic EPCs (eEPCs), retroinfused into the ischemic region of the pig heart, provided rapid paracrine benefit to acute and chronic ischemia in a PI-3K/Akt-dependent manner. In a model of acute myocardial ischemia, infarct size and loss of regional myocardial function decreased after eEPC application, unless cell pre-treatment with thymosin β4 shRNA was performed. Thymosin ß4 peptide retroinfusion mimicked the eEPC-derived improvement of infarct size and myocardial function. In chronic ischemia (rabbit model), eEPCs retroinfused into the ischemic hindlimb enhanced capillary density, collateral growth, and perfusion. Therapeutic neovascularization was absent when thymosin ß4 shRNA was introduced into eEPCs before application. In conclusion, eEPCs are capable of acute and chronic ischemia protection in a thymosin ß4 dependent manner. [10]
Thymosin β4: a candidate for treatment of stroke?
Neurorestorative therapy is the next frontier in the treatment of stroke. An expanding body of evidence supports the theory that after stroke, certain cellular changes occur that resemble early stages of development. Increased expression of developmental proteins in the area bordering the infarct suggest an active repair or reconditioning response to ischemic injury. Neurorestorative therapy targets parenchymal cells (neurons, oligodendrocytes, astrocyes, and endothelial cells) to enhance endogenous neurogenesis, angiogenesis, axonal sprouting, and synaptogenesis to promote functional recovery. Pharmacological treatments include statins, phosphodiesterase 5 inhibitors, erythropoietin, and nitric oxide donors that have all improved funtional outcome after stroke in the preclinial arena. Thymosin β4 (Tβ4) is expressed in both the developing and adult brain and it has been shown to stimulate vasculogenesis, angiogenesis, and arteriogenesis in the postnatal and adult murine cardiac myocardium. In this manuscript, we describe our rationale and techniques to test our hypothesis that Tβ4 may be a candidate neurorestorative agent. [11]
Prothymosin α as robustness molecule against ischemic stress to brain and retina

Following stroke or traumatic damage, neuronal death via both necrosis and apoptosis causes loss of functions, including memory, sensory perception, and motor skills. As necrosis has the nature to expand, while apoptosis stops the cell death cascade in the brain, necrosis is considered to be a promising target for rapid treatment for stroke. We identified the nuclear protein, prothymosin alpha (ProTα) from the conditioned medium of serum-free culture of cortical neurons as a key protein-inhibiting necrosis. In the culture of cortical neurons in the serum-free condition without any supplements, ProTα inhibited the necrosis, but caused apoptosis. In the ischemic brain or retina, ProTα showed a potent inhibition of both necrosis and apoptosis. By use of anti-brain-derived neurotrophic factor or anti-erythropoietin IgG, we found that ProTα inhibits necrosis, but causes apoptosis, which is in turn inhibited by ProTα-induced neurotrophins under the condition of ischemia. From the experiment using anti-ProTα IgG or antisense oligonucleotide for ProTα, it was revealed that ProTα has a pathophysiological role in protecting neurons in stroke.[12]

 
Thymosin β4 and cardiac repair
Hypoxic heart disease is a predominant cause of disability and death worldwide. As adult mammals are incapable of cardiac repair after infarction, the discovery of effective methods to achieve myocardial and vascular regeneration is crucial. Efforts to use stem cells to repopulate damaged tissue are currently limited by technical considerations and restricted cell potential. We discovered that the small, secreted peptide thymosin β4 (Tβ4) could be sufficiently used to inhibit myocardial cell death, stimulate vessel growth, and activate endogenous cardiac progenitors by reminding the adult heart on its embryonic program in vivo. The initiation of epicardial thickening accompanied by increase of myocardial and epicardial progenitors with or without infarction indicate that the reactivation process is independent of injury. Our results demonstrate Tβ4 to be the first known molecule able to initiate simultaneous myocardial and vascular regeneration after systemic administration in vivo. Given our findings, the utility of Tβ4 to heal cardiac injury may hold promise and warrant further investigation.[13]
Thymosin β4 facilitates epicardial neovascularization of the injured adult heart
schemic heart disease complicated by coronary artery occlusion causes myocardial infarction (MI), which is the major cause of morbidity and mortality in humans (http://www.who.int/cardiovascular_diseases/resources/atlas/en/index.html). After MI the human heart has an impaired capacity to regenerate and, despite the high prevalence of cardiovascular disease worldwide, there is currently only limited insight into how to stimulate repair of the injured adult heart from its component parts. Efficient cardiac regeneration requires the replacement of lost cardiomyocytes, formation of new coronary blood vessels, and appropriate modulation of inflammation to prevent maladaptive remodeling, fibrosis/scarring, and consequent cardiac dysfunction. Here we show that thymosin β4 (Tβ4) promotes new vasculature in both the intact and injured mammalian heart. We demonstrate that limited EPDC-derived endothelial-restricted neovascularization constitutes suboptimal “endogenous repair,” following injury, which is significantly augmented by Tβ4 to increase and stabilize the vascular plexus via collateral vessel growth. As such, we identify Tβ4 as a facilitator of cardiac neovascularization and highlight adult EPDCs as resident progenitors which, when instructed by Tβ4, have the capacity to sustain the myocardium after ischemic damage. [14]
Thymosin β4: a key factor for protective effects of eEPCs in acute and chronic ischemia

Acute myocardial infarction is still one of the leading causes of death in the industrial nations. Even after successful revascularization, myocardial ischemia results in a loss of cardiomyocytes and scar formation. Embryonic EPCs (eEPCs), retroinfused into the ischemic region of the pig heart, provided rapid paracrine benefit to acute and chronic ischemia in a PI-3K/Akt-dependent manner. In a model of acute myocardial ischemia, infarct size and loss of regional myocardial function decreased after eEPC application, unless cell pre-treatment with thymosin β4 shRNA was performed. Thymosin ß4 peptide retroinfusion mimicked the eEPC-derived improvement of infarct size and myocardial function. In chronic ischemia (rabbit model), eEPCs retroinfused into the ischemic hindlimb enhanced capillary density, collateral growth, and perfusion. Therapeutic neovascularization was absent when thymosin ß4 shRNA was introduced into eEPCs before application. In conclusion, eEPCs are capable of acute and chronic ischemia protection in a thymosin ß4 dependent manner.[15]

 
Thymosin β4: a candidate for treatment of stroke?
Neurorestorative therapy is the next frontier in the treatment of stroke. An expanding body of evidence supports the theory that after stroke, certain cellular changes occur that resemble early stages of development. Increased expression of developmental proteins in the area bordering the infarct suggest an active repair or reconditioning response to ischemic injury. Neurorestorative therapy targets parenchymal cells (neurons, oligodendrocytes, astrocyes, and endothelial cells) to enhance endogenous neurogenesis, angiogenesis, axonal sprouting, and synaptogenesis to promote functional recovery. Pharmacological treatments include statins, phosphodiesterase 5 inhibitors, erythropoietin, and nitric oxide donors that have all improved funtional outcome after stroke in the preclinial arena. Thymosin β4 (Tβ4) is expressed in both the developing and adult brain and it has been shown to stimulate vasculogenesis, angiogenesis, and arteriogenesis in the postnatal and adult murine cardiac myocardium. In this manuscript, we describe our rationale and techniques to test our hypothesis that Tβ4 may be a candidate neurorestorative agent.[16]
Thymosin β4: structure, function, and biological properties supporting current and future clinical applications

Published studies have described a number of physiological properties and cellular functions of thymosin β4 (Tβ4), the major G-actin-sequestering molecule in mammalian cells. Those activities include the promotion of cell migration, blood vessel formation, cell survival, stem cell differentiation, the modulation of cytokines, chemokines, and specific proteases, the upregulation of matrix molecules and gene expression, and the downregulation of a major nuclear transcription factor. Such properties have provided the scientific rationale for a number of ongoing and planned dermal, corneal, cardiac clinical trials evaluating the tissue protective, regenerative and repair potential of Tβ4, and direction for future clinical applications in the treatment of diseases of the central nervous system, lung inflammatory disease, and sepsis. A special emphasis is placed on the development of Tβ4 in the treatment of patients with ST elevation myocardial infarction in combination with percutaneous coronary intervention.[17]

The effect of thymosin treatment of venous ulcers

Venous ulcers are responsible for about 70% of the chronic ulcers of the lower limbs. Standard of care includes compression, dressings, debridement of devitalized tissue, and infection control. Thymosin beta 4 (Tβ4), a synthetic copy of the naturally occurring 43 amino-acid peptide, has been found to have wound healing and anti-inflammatory properties, and is thought to exert its therapeutic effect through promotion of keratinocyte and endothelial cell migration, increased collagen deposition, and stimulation of angiogenesis. To assess the safety, tolerability, and efficacy of topically administered Tβ4 in patients with venous stasis ulcers, a double-blind, placebo-controlled, dose-escalation study was conducted in eight European sites (five in Italy and three in Poland) that enrolled and randomized 73 patients. The safety profile of all doses of administered Tβ4 was deemed acceptable and comparable to placebo. Efficacy findings from this Phase 2 study suggest that a Tβ4 dose of 0.03% may have the potential to accelerate wound healing and that complete wound healing can be achieved within 3 months in about 25% of the patients, especially among those whose wounds are small to moderate in size or mild to moderate in severity.[18]

A randomized, placebo-controlled, single and multiple dose study of intravenous thymosin β4 in healthy volunteers

Synthetic thymosin beta 4 (Tβ4) may have a potential use in promoting myocardial cell survival during acute myocardial infarction. Four cohorts, with 10 healthy subjects each, were given a single intravenous dose of placebo or synthetic Tβ4. Cohorts received ascending doses of either 42, 140, 420, or 1260 mg. Following safety review, subjects were given the same dose regimen daily for 14 days. Safety evaluations, incidence of Treatment-Emergent Adverse Events, and pharmacokinetic parameters were evaluated. Adverse events were infrequent, and mild or moderate in intensity. There were no dose limiting toxicities or serious adverse events. Pharmacokinetic profile for single dose showed a dose proportional response, and an increasing half-life with increasing dose. Synthetic Tβ4 given intravenously as a single dose or in multiple daily doses for 14 days over a dose range of 42–1260 mg was well tolerated with no evidence of dose limiting toxicity. Further development for use in cardiac ischemia should be considered.[19]

Safety and Efficacy of an Injectable Extracellular Matrix Hydrogel for Treating Myocardial Infarction

  1. Sonya B. Seif-Naraghi1,*,
  2. Jennifer M. Singelyn1,*,
  3. Michael A. Salvatore2,
  4. Kent G. Osborn1,
  5. Jean J. Wang1,
  6. Unatti Sampat1,
  7. Oi Ling Kwan1,
  8. G. Monet Strachan1,
  9. Jonathan Wong3,
  10. Pamela J. Schup-Magoffin1,
  11. Rebecca L. Braden1,
  12. Kendra Bartels1,
  13. Jessica A. DeQuach2,
  14. Mark Preul4,
  15. Adam M. Kinsey2,
  16. Anthony N. DeMaria1,
  17. Nabil Dib1 and
  18. Karen L. Christman1,

+Author Affiliations

  1. 1University of California, San Diego, La Jolla, CA 92093, USA.
  2. 2Ventrix, Inc., San Diego, CA 92109, USA.
  3. 3Biologics Delivery Systems, Irwindale, CA 91706, USA.
  4. 4Barrow Neurological Institute, Phoenix, AZ 85013, USA.

+Author Notes

  • * These authors contributed equally to this work.
  1. †To whom correspondence should be addressed. E-mail: christman@eng.ucsd.edu

ABSTRACT

New therapies are needed to prevent heart failure after myocardial infarction (MI). As experimental treatment strategies for MI approach translation, safety and efficacy must be established in relevant animal models that mimic the clinical situation. We have developed an injectable hydrogel derived from porcine myocardial extracellular matrix as a scaffold for cardiac repair after MI. We establish the safety and efficacy of this injectable biomaterial in large- and small-animal studies that simulate the clinical setting. Infarcted pigs were treated with percutaneous transendocardial injections of the myocardial matrix hydrogel 2 weeks after MI and evaluated after 3 months. Echocardiography indicated improvement in cardiac function, ventricular volumes, and global wall motion scores. Furthermore, a significantly larger zone of cardiac muscle was found at the endocardium in matrix-injected pigs compared to controls. In rats, we establish the safety of this biomaterial and explore the host response via direct injection into the left ventricular lumen and in an inflammation study, both of which support the biocompatibility of this material. Hemocompatibility studies with human blood indicate that exposure to the material at relevant concentrations does not affect clotting times or platelet activation. This work therefore provides a strong platform to move forward in clinical studies with this cardiac-specific biomaterial that can be delivered by catheter.

  • Copyright © 2013, American Association for the Advancement of Science
Citation: S. B. Seif-Naraghi, J. M. Singelyn, M. A. Salvatore, K. G. Osborn, J. J. Wang, U. Sampat, O. L. Kwan, G. M. Strachan, J. Wong, P. J. Schup-Magoffin, R. L. Braden, K. Bartels, J. A. DeQuach, M. Preul, A. M. Kinsey, A. N. DeMaria, N. Dib, K. L. Christman, Safety and Efficacy of an Injectable Extracellular Matrix Hydrogel for Treating Myocardial Infarction.

RELATED RESOURCES ON SCIENCE SITES

In Science Translational Medicine

REFERENCES OF THYMOSIN IN CARDIOVASCULAR DISEASE

Thymosins in Health and Disease II: 3rd International Symposium on The Emerging Clinical Applications of Tymosin beta 4 in Cardiovascular Disease

Annals of the New York Academy of Sciences, October 2012 Volume 1270 Pages vii-ix, 1–121.

Allan L. Goldstein, Enrico Garaci, Editors, Thymosins in Cardiovascular Disease, November 2012, Wiley-Blackwell

http://onlinelibrary.wiley.com/doi/10.1111/nyas.2012.1270.issue-1/issuetoc

http://www.wiley.com/WileyCDA/WileyTitle/productCd-1573319104.html?cid=RSS_WILEY2_LIFEMED

1


Use of the cardioprotectants thymosin β4 and dexrazoxane during congenital heart surgery: proposal for a randomized, double-blind, clinical trial (pages 59–65) Daniel Stromberg, Tia Raymond, David Samuel, David Crockford, William Stigall, Steven Leonard, Eric Mendeloff and Andrew Gormley
Article first published online: 10 OCT 2012 | DOI: 10.1111/j.1749-6632.2012.06710.x

2


Cardiac repair with thymosin β4 and cardiac reprogramming factors (pages 66–72) Deepak Srivastava, Masaki Ieda, Jidong Fu and Li Qian
Article first published online: 10 OCT 2012 | DOI: 10.1111/j.1749-6632.2012.06696.x

3 NMR structural studies of thymosin α1 and β-thymosins (pages 73–78) David E. Volk, Cynthia W. Tuthill, Miguel-Angel Elizondo-Riojas and David G. Gorenstein
Article first published online: 10 OCT 2012 | DOI: 10.1111/j.1749-6632.2012.06656.x

4

Thymosin β4 sustained release from poly(lactide-co-glycolide) microspheres: synthesis and implications for treatment of myocardial ischemia (pages 112–119) Jeffrey E. Thatcher, Tré Welch, Robert C. Eberhart, Zoltan A. Schelly and J. Michael DiMaio
Article first published online: 10 OCT 2012 | DOI: 10.1111/j.1749-6632.2012.06681.x

5 Corrigendum for Ann. N.Y. Acad. Sci. 2012. 1254: 57–65 (page 121) Article first published online: 10 OCT 2012 | DOI: 10.1111/j.1749-6632.2012.06793.x
This article corrects:
A bird’s-eye view of cell therapy and tissue engineering for cardiac regeneration
Vol. 1254, Issue 1, 57–65, Article first published online: 30 APR 2012

Thymosins in Health and Disease: 2nd International Symposium,
Annals of the New York Academy of Sciences, May 2010 Volume 1194 Pages ix–xi, 1–230 

http://onlinelibrary.wiley.com/doi/10.1111/nyas.2010.1194.issue-1/issuetoc

6. Preface to Thymosins in Health and Disease (pages ix–xi) Enrico Garaci and Allan L. Goldstein
Article first published online: 3 MAY 2010 | DOI: 10.1111/j.1749-6632.2010.05493.x

7.
Thymosin β4 and cardiac repair (pages 87–96) Santwana Shrivastava, Deepak Srivastava, Eric N. Olson, J. Michael DiMaio and Ildiko Bock-Marquette
Article first published online: 3 MAY 2010 | DOI: 10.1111/j.1749-6632.2010.05468.x

8.
Thymosin β4 facilitates epicardial neovascularization of the injured adult heart (pages 97–104) Nicola Smart, Catherine A. Risebro, James E. Clark, Elisabeth Ehler, Lucile Miquerol, Alex Rossdeutsch, Michael S. Marber and Paul R. Riley
Article first published online: 3 MAY 2010 | DOI: 10.1111/j.1749-6632.2010.05478.x

9.
Thymosin β4 enhances repair by organizing connective tissue and preventing the appearance of myofibroblasts (pages 118–124) H. Paul Ehrlich and Sprague W. Hazard III
Article first published online: 3 MAY 2010 | DOI: 10.1111/j.1749-6632.2010.05483.x

10. Thymosin β4: a key factor for protective effects of eEPCs in acute and chronic ischemia (pages 105–111) Rabea Hinkel, Ildiko Bock-Marquette, Antonis K. Hazopoulos and Christian Kupatt
Article first published online: 3 MAY 2010 | DOI: 10.1111/j.1749-6632.2010.05489.x
Corrected by:
Corrigendum for Ann. N. Y. Acad. Sci. 1194: 105–111
Vol. 1205, Issue 1, 284, Article first published online: 14 SEP 2010

11.

Thymosin β4: a candidate for treatment of stroke? (pages 112–117) Daniel C. Morris, Michael Chopp, Li Zhang and Zheng G. Zhang
Article first published online: 3 MAY 2010 | DOI: 10.1111/j.1749-6632.2010.05469.x

12. Prothymosin α as robustness molecule against ischemic stress to brain and retina (pages 20–26) Hiroshi Ueda, Hayato Matsunaga, Hitoshi Uchida and Mutsumi Ueda
Article first published online: 3 MAY 2010 | DOI: 10.1111/j.1749-6632.2010.05466.x

13.
Thymosin β4 and cardiac repair (pages 87–96) Santwana Shrivastava, Deepak Srivastava, Eric N. Olson, J. Michael DiMaio and Ildiko Bock-Marquette
Article first published online: 3 MAY 2010 | DOI: 10.1111/j.1749-6632.2010.05468.x

14.

Thymosin β4 facilitates epicardial neovascularization of the injured adult heart (pages 97–104) Nicola Smart, Catherine A. Risebro, James E. Clark, Elisabeth Ehler, Lucile Miquerol, Alex Rossdeutsch, Michael S. Marber and Paul R. Riley
Article first published online: 3 MAY 2010 | DOI: 10.1111/j.1749-6632.2010.05478.x

15.

Thymosin β4: a key factor for protective effects of eEPCs in acute and chronic ischemia (pages 105–111) Rabea Hinkel, Ildiko Bock-Marquette, Antonis K. Hazopoulos and Christian Kupatt
Article first published online: 3 MAY 2010 | DOI: 10.1111/j.1749-6632.2010.05489.x
Corrected by:
Corrigendum for Ann. N. Y. Acad. Sci. 1194: 105–111
Vol. 1205, Issue 1, 284, Article first published online: 14 SEP 2010

16.

Thymosin β4: a candidate for treatment of stroke? (pages 112–117) Daniel C. Morris, Michael Chopp, Li Zhang and Zheng G. Zhang
Article first published online: 3 MAY 2010 | DOI: 10.1111/j.1749-6632.2010.05469.x

17.Thymosin β4: structure, function, and biological properties supporting current and future clinical applications (pages 179–189) David Crockford, Nabila Turjman, Christian Allan and Janet Angel
Article first published online: 3 MAY 2010 | DOI: 10.1111/j.1749-6632.2010.05492.x

18.

The effect of thymosin treatment of venous ulcers (pages 207–212) G. Guarnera, A. DeRosa and R. Camerini, on behalf of 8 European sites
Article first published online: 3 MAY 2010 | DOI: 10.1111/j.1749-6632.2010.05490.x

19.
A randomized, placebo-controlled, single and multiple dose study of intravenous thymosin β4 in healthy volunteers (pages 223–229) Dennis Ruff, David Crockford, Gino Girardi and Yuxin Zhang
Article first published online: 3 MAY 2010 | DOI: 10.1111/j.1749-6632.2010.05474.x

Other related articles on this Open Access Online Scientific Journal include the following:

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Heart Renewal by pre-existing Cardiomyocytes: Source of New Heart Cell Growth Discovered

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Reporter: Aviva Lev-Ari, PhD, RN

Regulus Therapeutics and UC San Diego to Collaborate on Angiogenic Disease Research Utilizing microRNA Technology

http://www.fiercebiotech.com/press-releases/regulus-therapeutics-and-uc-san-diego-collaborate-angiogenic-disease-resear-0

– UC Discovery Grant award to support collaborative research –

La Jolla, Calif., April 14, 2011 – Regulus Therapeutics Inc., a biopharmaceutical company leading the discovery and development of innovative new medicines targeting microRNAs, today announced it is collaborating with researchers at the University of California, San Diego (UCSD) School of Medicine seeking novel treatments for angiogenic diseases using microRNA therapeutics. The research will combine Regulus’ leading microRNA platform with UCSD’s expertise in animal models of angiogenesis to discover anti-angiogenic microRNA-targeted therapies that could be rapidly translated for treatment of human disease.  The collaborative research program was the recent recipient of a UC Discovery Grant that promotes collaborations between the university’s researchers and industry partners.  Financial terms of the grant were not disclosed.

“We are pleased to collaborate with leading scientific institutes like UCSD and to provide industry support for programs such as the UC Discovery Grant,” said Hubert C. Chen, M.D., Regulus’ vice president of translational medicine. “Regulus continues to demonstrate a leadership position in the field of microRNA therapeutics and is committed to forging partnerships with leading academic and clinical laboratories to advance microRNA biology and therapeutic discovery.  Our network of nearly 30 academic collaborations assists us with the investigation of new microRNAs and supports microRNA discovery efforts that feed the Company’s pipeline.”

Angiogenesis, which is the formation of new blood vessels, is an important event that contributes to the severity of cancer, diabetes, macular degeneration, inflammatory disease and arthritis.  microRNAs have been implicated in regulating biological networks involved in angiogenesis.

“Our research published last year in Nature Medicine demonstrated that microRNA-132 functions as a novel angiogenic switch that turns on angiogenesis in quiescent endothelial cells, and that targeting with an anti-miR-132 decreases blood vessel formation,” said David A. Cheresh, Ph.D., professor of pathology in the UCSD School of Medicine, associate director for translational research at UCSD Moores Cancer Center and principal investigator on the grant. “The objective of our collaborative work with Regulus is to advance these initial discoveries and discover additional microRNAs involved in angiogenic diseases.”

The UC Discovery Grant program promotes collaborations between the university’s researchers and industry partners in the interest of supporting cutting-edge research, strengthening the state’s economy and serving the public good.

About microRNAs

The discovery of microRNA in humans during the last decade is one of the most exciting scientific breakthroughs in recent history. microRNAs are small RNA molecules, typically 20 to 25 nucleotides in length, that do not encode proteins but instead regulate gene expression. More than 700 microRNAs have been identified in the human genome, and over one-third of all human genes are believed to be regulated by microRNAs. A single microRNA can regulate entire networks of genes. As such, these molecules are considered master regulators of the human genome. microRNAs have been shown to play an integral role in numerous biological processes, including the immune response, cell-cycle control, metabolism, viral replication, stem cell differentiation and human development. Most microRNAs are conserved across multiple species, indicating the evolutionary importance of these molecules as modulators of critical biological pathways. Indeed, microRNA expression or function, has been shown to be significantly altered in many disease states, including cancer, heart failure and viral infections. Targeting microRNAs with anti-miRs, antisense oligonucleotide inhibitors of microRNAs, or miR-mimics, double-stranded oligonucleotides to replace microRNA function opens potential for a novel class of therapeutics and offers a unique approach to treating disease by modulating entire biological pathways. To learn more about microRNAs, please visit http://www.regulusrx.com/microrna/microrna-explained.php.

About Regulus Therapeutics Inc.

Regulus Therapeutics is a biopharmaceutical company leading the discovery and development of innovative new medicines targeting microRNAs. Regulus is using a mature therapeutic platform based on technology that has been developed over 20 years and tested in more than 5,000 humans. In addition, Regulus works with a broad network of academic collaborators and leverages the oligonucleotide drug discovery and development expertise of its founding companies, Alnylam Pharmaceuticals (NASDAQ:ALNY) and Isis Pharmaceuticals (NASDAQ:ISIS). Regulus is advancing microRNA therapeutics towards the clinic in several key areas including hepatitis C infection, immuno-inflammatory diseases, fibrosis, oncology and cardiovascular/metabolic diseases. Regulus’ intellectual property estate contains both the fundamental and core patents in the field and includes over 600 patents and more than 300 pending patent applications pertaining primarily to chemical modifications of oligonucleotides targeting microRNAs for therapeutic applications. In April 2008, Regulus formed a major alliance with GlaxoSmithKline to discover and develop microRNA therapeutics for immuno-inflammatory diseases. In February 2010, Regulus and GlaxoSmithKline entered into a new collaboration to develop and commercialize microRNA therapeutics targeting microRNA-122 for the treatment of hepatitis C infection. In June 2010, Regulus and sanofi-aventis entered into the largest-to-date strategic alliance for the development of microRNA therapeutics. This alliance is focused initially on fibrosis. For more information, please visit http://www.regulusrx.com.

Forward-Looking Statements

This press release includes forward-looking statements regarding the future therapeutic and commercial potential of Regulus’ business plans, technologies and intellectual property related to microRNA therapeutics being discovered and developed by Regulus. Any statement describing Regulus’ goals, expectations, financial or other projections, intentions or beliefs is a forward-looking statement and should be considered an at-risk statement. Such statements are subject to certain risks and uncertainties, particularly those inherent in the process of discovering, developing and commercializing drugs that are safe and effective for use as human therapeutics, and in the endeavor of building a business around such products. Such forward-looking statements also involve assumptions that, if they never materialize or prove correct, could cause the results to differ materially from those expressed or implied by such forward-looking statements. Although these forward-looking statements reflect the good faith judgment of Regulus’ management, these statements are based only on facts and factors currently known by Regulus. As a result, you are cautioned not to rely on these forward-looking statements. These and other risks concerning Regulus’ programs are described in additional detail in each of Alnylam’s and Isis’ annual report on Form 10-K for the year ended December 31, 2010, which are on file with the SEC. Copies of these and other documents are available from either Alnylam or Isis.

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Reporter: Prabodh Kandala, PhD

Researchers at the University of California, San Diego School of Medicine and Moores Cancer Center have identified a new biomarker and therapeutic target for pancreatic cancer, an often-fatal disease for which there is currently no reliable method for early detection or therapeutic intervention.

Pancreatic ductal adenocarcinoma, or PDAC, is the fourth-leading cause of cancer-related death. Newly diagnosed patients have a median survival of less than one year, and a 5-year survival rate of only 3 to 5 percent. Therefore, biomarkers that can identify early onset of PDAC and which could be viable drug targets are desperately needed.

‘”We found that a kinase called PEAK1 is turned on very early in pancreatic cancer,” said first author Jonathan Kelber, PhD, a postdoctoral researcher in the UCSD Department of Pathology and Moores Cancer Center. “This protein was clearly detected in biopsies of malignant tumors from human patients — at the gene and the protein levels — as well as in mouse models.”

PEAK1 is a type of tyrosine kinase — an enzyme, or type of protein, that speeds up chemical reactions and acts as an “on” or “off” switch in many cellular functions. The fact that PEAK1 expression is increased in human PDAC and that its catalytic activity is important for PDAC cell proliferation makes it an important candidate as a biomarker and therapeutic target for small molecule drug discovery.

In addition to showing that levels of PEAK1 are increased during PDAC progression, the scientists found that PEAK1 is necessary for the cancer to grow and metastasize.

“PEAK1 is a critical signaling hub, regulating cell migration and proliferation,” said Kelber. “We found that if you knock it out in PDAC cells, they form significantly smaller tumors in preclinical mouse models and fail to metastasize efficiently.”

The research team, led by principal investigator Richard Klemke, PhD, UCSD professor of pathology, studied a large, on-line data base of gene expression profiles to uncover the presence of PEAK1 in PDAC. These findings were corroborated at the protein level in patient biopsy samples from co-investigator Michael Bouvet, MD, and in mouse models developed by Andrew M. Lowy, MD, both of the UCSD Department of Surgery at Moores Cancer Center.

While many proteins are upregulated in cancers of the pancreas, there has been limited success in identifying candidates that, when inhibited, have potential as clinically approved therapeutics. However, the researchers found that inhibition of PEAK1-dependent signaling sensitized PDAC cells to existing chemotherapies such as Gemitabine, and immunotherapies such as Trastuzumab.

“Survival rates for patients with pancreatic cancer remain low,” said Bouvet. “Therefore, earlier detection and novel treatment strategies are very important if we are going to make any progress against pancreatic cancer. Since current therapies are often ineffective, our hope is that the findings from this research will open up a new line of investigation to bring a PEAK1 inhibitor to the clinic.”

Abstract:

Early biomarkers and effective therapeutic strategies are desperately needed to treat pancreatic ductal adenocarcinoma (PDAC), which has a dismal 5-year patient survival rate. Here, we report that the novel tyrosine kinase PEAK1 is upregulated in human malignancies, including human PDACs and pancreatic intraepithelial neoplasia (PanIN). Oncogenic KRas induced a PEAK1-dependent kinase amplification loop between Src, PEAK1, and ErbB2 to drive PDAC tumor growth and metastasis in vivo. Surprisingly, blockade of ErbB2 expression increased Src-dependent PEAK1 expression, PEAK1-dependent Src activation, and tumor growth in vivo, suggesting a mechanism for the observed resistance of patients with PDACs to therapeutic intervention. Importantly, PEAK1 inactivation sensitized PDAC cells to trastuzumab and gemcitabine therapy. Our findings, therefore, suggest that PEAK1 is a novel biomarker, critical signaling hub, and new therapeutic target in PDACs. Cancer Res; 72(10); 2554–64. ©2012 AACR.

http://cancerres.aacrjournals.org/content/72/10/2554

http://www.sciencedaily.com/releases/2012/05/120515070305.htm

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