Heart Disease

Coding Dimension ID: 
295
Coding Dimension path name: 
Heart Disease
Funding Type: 
Early Translational I
Grant Number: 
TR1-01249
Investigator: 
Name: 
Institution: 
Type: 
PI
ICOC Funds Committed: 
$6 762 954
Disease Focus: 
Bone or Cartilage Disease
Stroke
Neurological Disorders
Heart Disease
Neurological Disorders
Skin Disease
Stem Cell Use: 
Adult Stem Cell
oldStatus: 
Active
Public Abstract: 
All adult tissues contain stem cells. Some tissues, like bone marrow and skin, harbor more adult stem cells; other tissues, like muscle, have fewer. When a tissue or organ is injured these stem cells possess a remarkable ability to divide and multiply. In the end, the ability of a tissue to repair itself seems to depend on how many stem cells reside in a particular tissue, and the state of those stem cells. For example, stress, disease, and aging all diminish the capacity of adult stem cells to self-renew and to proliferate, which in turn hinders tissue regeneration. Our strategy is to commandeer the molecular machinery responsible for adult stem cell self-renewal and proliferation and by doing so, stimulate the endogenous program of tissue regeneration. This approach takes advantage of the solution that Nature itself developed for repairing damaged or diseased tissues, and controls adult stem cell proliferation in a localized, highly controlled fashion. This strategy circumvents the immunological, medical, and ethical hurdles that exist when exogenous stem cells are introduced into a human. When utilizing this strategy the goal of reaching clinical trials in human patients within 5 years becomes realistic. Specifically, we will target the growing problem of neurologic, musculoskeletal, cardiovascular, and wound healing diseases by local delivery of a protein that promotes the body’s inherent ability to repair and regenerate tissues. We have evidence that this class of proteins, when delivered locally to an injury site, is able to stimulate adult tissue stem cells to grow and repair/replace the deficient tissue following injury. We have developed technologies to package the protein in a specialized manner that preserves its biological activity but simultaneously restricts its diffusion to unintended regions of the body. For example, when we treat a skeletal injury with this packaged protein we augment the natural ability to heal bone by 350%; and when this protein is delivered to the heart immediately after an infarction cardiac output is improved and complications related to scarring are reduced. This remarkable capacity to augment tissue healing is not limited to bones and the heart: the same powerful effect can be elicited in the brain, and skin injuries. The disease targets of stroke, bone fractures, heart attacks, and skin wounds and ulcers represent an enormous health care burden now, but this burden is expected to skyrocket because our population is quickly aging. Thus, our proposal addresses a present and ongoing challenge to healthcare for the majority of Californians, with a novel therapeutic strategy that mimics the body’s inherent repair mechanisms.
Statement of Benefit to California: 
Californians represent 1 in 7 Americans, and make up the single largest healthcare market in the United States. The diseases and injuries that affect Californians affect the rest of the US, and the world. For example, stroke is the third leading cause of death, with more than 700,000 people affected every year. It is a leading cause of serious long-term disability, with an estimated 5.4 million stroke survivors currently alive today. Symptoms of musculoskeletal disease are the number two most cited reasons for visit to a physician. Musculoskeletal disease is the leading cause of work-related and physical disability in the United States, with arthritis being the leading chronic condition reported by the elderly. In adults over the age of 70, 40% suffer from osteoarthritis of the knee and of these nearly 80% have limitation of movement. By 2030, nearly 67 million US adults will be diagnosed with arthritis. Cardiovascular disease is the leading cause of death, and is a major cause of disability worldwide. The annual socioeconomic burden posed by cardiovascular disease is estimated to exceed $400 billion annually and remains a major cause of health disparities and rising health care costs. Skin wounds from burns, trauma, or surgery, and chronic wounds associated with diabetes or pressure ulcer, exact a staggering toll on our healthcare system: Burns alone affect 1.25M Americans each year, and the economic global burden of these injuries approaches $50B/yr. In California alone, the annual healthcare expenditures for stroke, skeletal repair, heart attacks, and skin wound healing are staggering and exceed 700,000 cases, 3.5M hospital days, and $34B. We have developed a novel, protein-based therapeutic platform to accelerate and enhance tissue regeneration through activation of adult stem cells. This technology takes advantage of a powerful stem cell factor that is essential for the development and repair of most of the body’s tissues. We have generated the first stable, biologically active recombinant Wnt pathway agonist, and showed that this protein has the ability to activate adult stem cells after tissue injury. Thus, our developmental candidate leverages the body’s natural response to injury. We have generated exciting preclinical results in a variety of animals models including stroke, skeletal repair, heart attack, and skin wounding. If successful, this early translational award would have enormous benefits for the citizens of California and beyond.
Progress Report: 
  • In the first year of CIRM funding our objectives were to optimize the activity of the Wnt protein for use in the body and then to test, in a variety of injury models, the effects of this lipid-packaged form of Wnt. We have made considerable progress on both of these fronts. For example, in Roel Nusse and Jill Helms’ groups, we have been able to generate large amounts of the mouse form of Wnt3a protein and package it into liposomal vesicles, which can then be used by all investigators in their studies of injury and repair. Also, Roel Nusse succeeded in generating human Wnt3a protein. This is a major accomplishment since our ultimate goal is to develop this regenerative medicine tool for use in humans. In Jill Helms’ lab we made steady progress in standardizing the activity of the liposomal Wnt3a formulation, and this is critically important for all subsequent studies that will compare the efficacy of this treatment across multiple injury repair scenarios.
  • Each group began testing the effects of liposomal Wnt3a treatment for their particular application. For example, in Theo Palmer’s group, the investigators tested how liposomal Wnt3a affected cells in the brain following a stroke. We previously found that Wnt3A promotes the growth of neural stem cells in a petri dish and we are now trying to determine if delivery of Wnt3A can enhance the activity of endogenous stem cells in the brain and improve the level of recovery following stroke. Research in the first year examined toxicity of a liposome formulation used to deliver Wnt3a and we found it to be well tolerated after injection into the brains of mice. We also find that liposomal Wnt3a can promote the production of new neurons following stroke. The ongoing research involves experiments to determine if these changes in stem cell activity are accompanied by improved neurological function. In Jill Helms’ group, the investigators tested how liposomal Wnt3a affected cells in a bone injury site. We made a significant discovery this year, by demonstrating that liposomal Wnt3a stimulates the proliferation of skeletal progenitor cells and accelerates their differentiation into osteoblasts (published in Science Translational Medicine 2010). We also started testing liposomal Wnt3a for safety and toxicity issues, both of which are important prerequisites for use of liposomal Wnt3a in humans. Following a heart attack (i.e., myocardial infarction) we found that endogenous Wnt signaling peaks between post-infarct day 5-7. We also found that small aggregates of cardiac cells called cardiospheres respond to Wnt in a dose-responsive manner. In skin wounds, we tested the effect of boosting Wnt signaling during skin wound healing. We found that the injection of Wnt liposomes into wounds enhanced the regeneration of hair follicles, which would otherwise not regenerate and make a scar instead. The speed and strength of wound closure are now being measured.
  • In aggregate, our work on this project continues to move forward with a number of great successes, and encouraging data to support our hypothesis that augmenting Wnt signaling following tissue injury will provide beneficial effects.
  • In the second year of CIRM funding our objectives were to optimize packaging of the developmental candidate, Wnt3a protein, and then to continue to test its efficacy to enhance tissue healing. We continue to make considerable progress on the stated objectives. In Roel Nusse’s laboratory, human Wnt3a protein is now being produced using an FDA-approved cell line, and Jill Helms’ lab the protein is effectively packaged into lipid particles that delay degradation of the protein when it is introduced into the body.
  • Each group has continued to test the effects of liposomal Wnt3a treatment for their particular application. In Theo Palmer’s group we have studied how liposomal Wnt3a affects neurogenesis following stroke. We now know that liposomal Wnt3a transiently stimulates neural progenitor cell proliferation. We don’t see any functional improvement after stroke, though, which is our primary objective.
  • In Jill Helms’ group we’ve now shown that liposomal Wnt3a enhances fracture healing and osseointegration of dental and orthopedic implants and now we demonstrate that liposomal Wnt3a also can improve the bone-forming capacity of bone marrow grafts, especially when they are taken from aged animals.
  • We’ve also tested the ability of liposomal Wnt3a to improve heart function after a heart attack (i.e., myocardial infarction). Small aggregates of cardiac progenitor cells called cardiospheres proliferate to Wnt3a in a dose-responsive manner, and we see an initial improvement in cardiac function after treatment of cells with liposomal Wnt3a. the long-term improvements, however, are not significant and this remains our ultimate goal. In skin wounds, we tested the effect of boosting Wnt signaling during wound healing. We found that the injection of liposomal Wnt3a into wounds enhanced the regeneration of hair follicles, which would otherwise not regenerate and make a scar instead. The speed of wound closure is also enhanced in regions of the skin where there are hair follicles.
  • In aggregate, our work continues to move forward with a number of critical successes, and encouraging data to support our hypothesis that augmenting Wnt signaling following tissue injury will provide beneficial effects.
  • Every adult tissue harbors stem cells. Some tissues, like bone marrow and skin, have more adult stem cells and other tissues, like muscle or brain, have fewer. When a tissue is injured, these stem cells divide and multiply but only to a limited extent. In the end, the ability of a tissue to repair itself seems to depend on how many stem cells reside in a particular tissue, and the state of those stem cells. For example, stress, disease, and aging all diminish the capacity of adult stem cells to respond to injury, which in turn hinders tissue healing. One of the great unmet challenges for regenerative medicine is to devise ways to increase the numbers of these “endogenous” stem cells, and revive their ability to self-renew and proliferate.
  • The scientific basis for our work rests upon our demonstration that a naturally occurring stem cell growth factor, Wnt3a, can be packaged and delivered in such a way that it is robustly stimulates stem cells within an injured tissue to divide and self-renew. This, in turn, leads to unprecedented tissue healing in a wide array of bone injuries especially in aged animals. As California’s population ages, the cost to treat such skeletal injuries in the elderly will skyrocket. Thus, our work addresses a present and ongoing challenge to healthcare for the majority of Californians and the world, and we do it by mimicking the body’s natural response to injury and repair.
  • To our knowledge, there is no existing technology that displays such effectiveness, or that holds such potential for the stem cell-based treatment of skeletal injuries, as does a L-Wnt3a strategy. Because this approach directly activates the body’s own stem cells, it avoids many of the pitfalls associated with the introduction of foreign stem cells or virally reprogrammed autologous stem cells into the human body. In summary, our data show that L-Wnt3a constitutes a viable therapeutic approach for the treatment of skeletal injuries, especially those in individuals with diminished healing potential.
  • This progress report covers the period between Sep 01 2012through Aug 31 2013, and summarizes the work accomplished under ET funding TR1-01249. Under this award we developed a Wnt protein-based platform for activating a patient’s own stem cells for the purpose of tissue regeneration.
  • At the beginning of our grant period we generated research grade human WNT3A protein in quantities sufficient for all our discovery experiments. We then tested the ability of this WNT protein therapeutic to improve the healing response in animal models of stroke, heart attack, skin wounding, and bone fracture. These experimental models recapitulated some of the most prevalent and debilitating human diseases that collectively, affect millions of Californians.
  • At the end of year 2, we assembled an external review panel to select the promising clinical indication. The scientific advisory board unanimously selected skeletal repair as the leading indication. The WNT protein is notoriously difficult to purify; consequently in year 3 we developed new methods to streamline the purification of WNT proteins, and the packaging of the WNT protein into liposomal vesicles that stabilized the protein for in vivo use.
  • In years 3 and 4 we continued to accrue strong scientific evidence in both large and small animal models that a WNT protein therapeutic accelerates bone regeneration in critical size bony non-unions, in fractures, and in cases of implant osseointegration. In this last year of funding, we clarified and characterized the mechanism of action of the WNT protein, by showing that it activates endogenous stem cells, which in turn leads to faster healing of a range of different skeletal defects.
  • In this last year we also identified a therapeutic dose range for the WNT protein, and developed a route and method of delivery that was simultaneously effective and yet limited the body’s exposure to this potent stem cell factor. We initiated preliminary safety studies to identify potential risks, and compared the effects of WNT treatment with other commercially available bone growth factors. In sum, we succeeded in moving our early translational candidate from exploratory studies to validation, and are now ready to enter into the IND-enabling phase of therapeutic candidate development.
  • This progress report covers the period between Sep 01 2013 through April 30 2014, and summarizes the work accomplished under ET funding TR101249. Under this award we developed a Wnt protein-based platform for activating a patient’s own stem cells for purposes of tissue regeneration.
  • At the beginning of our grant period we generated research grade human WNT3A protein in quantities sufficient for all our discovery experiments. We then tested the ability of this WNT protein therapeutic to improve the healing response in animal models of stroke, heart attack, skin wounding, and bone fracture. These experimental models recapitulated some of the most prevalent and debilitating human diseases that collectively, affect millions of Californians. At the conclusion of Year 2 an external review panel was assembled and charged with the selection of a single lead indication for further development. The scientific advisory board unanimously selected skeletal repair as the lead indication.
  • In year 3 we accrued addition scientific evidence, using both large and small animal models, demonstrating that a WNT protein therapeutic accelerated bone healing. Also, we developed new methods to streamline the purification of WNT proteins, and improved our method of packaging of the WNT protein into liposomal vesicles (e.g., L-WNT3A) for in vivo use.
  • In year 4 we clarified the mechanism of action of L-WNT3A, by demonstrating that it activates endogenous stem cells and therefore leads to accelerated bone healing. We also continued our development studies, by identifying a therapeutic dose range for L-WNT3A, as well as a route and method of delivery that is both effective and safe. We initiated preliminary safety studies to identify potential risks, and compared the effects of L-WNT3A with other, commercially available bone growth factors.
  • In year 5 we initiated two new preclinical studies aimed at demonstrating the disease-modifying activity of L-WNT3A in spinal fusion and osteonecrosis. These two new indications were chosen by a CIRM review panel because they represent an unmet need in California and the nation. We also initiated development of a scalable manufacturing and formulation process for both the WNT3A protein and L-WNT3A formulation. These two milestones were emphasized by the CIRM review panel to represent major challenges to commercialization of L-WNT3A; consequently, accomplishment of these milestones is a critical yardstick by which progress towards an IND filing can be assessed.
  • With regards to objective 1, we employed established animal models of spinal fusion and osteonecrosis to demonstrate the disease-mitigating activity of our Developmental Candidate, autograftWNT.
  • With regards to objective 2, the mechanism of L-WNT3A action has been demonstrated in ex vivo, non-GLP pharmacology studies.
  • With regards to objective 3, we have completed characterization of the non-GLP substance, WNT3A drug product, and the drug product, L-WNT3A. Methods for reproducible and scaleable research grade production of the drug substance WNT3A, and the drug product, L-WNT3A, have been developed (see below for details). A serum free process has been achieved.
Funding Type: 
Tools and Technologies II
Grant Number: 
RT2-02060
Investigator: 
Institution: 
Type: 
PI
ICOC Funds Committed: 
$1 869 487
Disease Focus: 
Blood Disorders
Heart Disease
Liver Disease
Stem Cell Use: 
Embryonic Stem Cell
iPS Cell
oldStatus: 
Active
Public Abstract: 
Purity is as important for cell-based therapies as it is for treatments based on small-molecule drugs or biologics. Pluripotent stem cells possess two properties: they are capable of self regeneration and they can differentiate to all different tissue types (i.e. muscle, brain, heart, etc.). Despite the promise of pluripotent stem cells as a tool for regenerative medicine, these cells cannot be directly transplanted into patients. In their undifferentiated state they harbor the potential to develop into tumors. Thus, tissue-specific stem cells as they exist in the body or as derived from pluripotent cells are the true targets of stem cell-based therapeutic research, and the cell types most likely to be used clinically. Existing protocols for the generation of these target cells involve large scale differentiation cultures of pluripotent cells that often produce a mixture of different cell types, only a small fraction of which may possess therapeutic potential. Furthermore, there remains the real danger that a small number of these cells remains undifferentiated and retains tumor-forming potential. The ideal pluripotent stem cell-based therapeutic would be a pure population of tissue specific stem cells, devoid of impurities such as undifferentiated or aberrantly-differentiated cells. We propose to develop antibody-based tools and protocols to purify therapeutic stem cells from heterogeneous cultures. We offer two general strategies to achieve this goal. The first is to develop antibodies and protocols to identify undifferentiated tumor-forming cells and remove them from cultures. The second strategy is to develop antibodies that can identify and isolate heart stem cells, and blood-forming stem cells capable of engraftment from cultures of pluripotent stem cells. The biological underpinning of our approach is that each cell type can be identified by a signature surface marker expression profile. Antibodies that are specific to cell surface markers can be used to identify and isolate stem cells using flow cytometry. We can detect and isolate rare tissue stem cells by using combinations of antibodies that correspond to the surface marker signature for the given tissue stem cell. We can then functionally characterize the potential of these cells for use in regenerative medicine. Our proposal aims to speed the clinical application of therapies derived from pluripotent cell products by reducing the risk of transplanting the wrong cell type - whether it is a tumor-causing residual pluripotent cell or a cell that is not native to the site of transplant - into patients. Antibodies, which exhibit exquisitely high sensitivity and specificity to target cellular populations, are the cornerstone of our proposal. The antibodies (and other technologies and reagents) identified and generated as a result of our experiments will greatly increase the safety of pluripotent stem cell-derived cellular therapies.
Statement of Benefit to California: 
Starting with human embryonic stem cells (hESC), which are capable of generating all cell types in the body, we aim to identify and isolate two tissue-specific stem cells – those that can make the heart and the blood – and remove cells that could cause tumors. Heart disease remains the leading cause of mortality and morbidity in the West. In California, 70,000 people die annually from cardiovascular diseases, and the cost exceeded $48 billion in 2006. Despite major advancement in treatments for patients with heart failure, which is mainly due to cellular loss upon myocardial injury, the mortality rate remains high. Similarly, diseases of the blood-forming system, e.g. leukemias, remain a major health problem in our state. hESC and induced pluripotent stem cells (collectively, pluripotent stem cells, or PSC) could provide an attractive therapeutic option to treat patients with damaged or defective organs. PCS can differentiate into, and may represent a major source of regenerating, cells for these organs. However, the major issues that delay the clinical translation of PSC derivatives include lack of purification technologies for heart- or blood-specific stem cells from PSC cultures and persistence of pluripotent cells that develop into teratomas. We propose to develop reagents that can prospectively identify and isolate heart and blood stem cells, and to test their functional benefit upon engraftment in mice. We will develop reagents to identify and remove residual PSC, which give rise to teratomas. These reagents will enable us to purify patient-specific stem cells, which lack cancer-initiating potential, to replenish defective or damaged tissue. The reagents generated in these studies can be patented forming an intellectual property portfolio shared by the state and the institutions where the research is carried out. The funds generated from the licensing of these technologies will provide revenue for the state, will help increase hiring of faculty and staff (many of whom will bring in other, out-of-state funds to support their research) and could be used to ameliorate the costs of clinical trials – the final step in translation of basic science research to clinical use. Only California businesses are likely to be able to license these reagents and to develop them into diagnostic and therapeutic entities; such businesses are at the heart of the CIRM strategy to enhance the California economy. Most importantly, this research will set the platform for future stem cell-based therapies. Because tissue stem cells are capable of lifelong self-renewal, stem cell therapies have the potential to be a single, curative treatment. Such therapies will address chronic diseases with no cure that cause considerable disability, leading to substantial medical expense. We expect that California hospitals and health care entities will be first in line for trials and therapies. Thus, California will benefit economically and it will help advance novel medical care.
Progress Report: 
  • Our program is focused on improving methods that can be used to purify stem cells so that they can be used safely and effectively for therapy. A significant limitation in translating laboratory discoveries into clinical practice remains our inability to separate specific stem cells that generate one type of desired tissue from a mixture of ‘pluripotent’ stem cells, which generate various types of tissue. An ideal transplant would then consist of only tissue-specific stem cells that retain a robust regenerative potential. Pluripotent cells, on the other hand, pose the risk, when transplanted, of generating normal tissue in the wrong location, abnormal tissue, or cancer. Thus, we have concentrated our efforts to devise strategies to either make pluripotent cells develop into desired tissue-specific stem cells or to separate these desired cells from a mixture of many types of cells.
  • Our approach to separating tissue-specific stem cells from mixed cultures is based on the theory that every type of cell has a very specific set of molecules on its surface that can act as a signature. Once this signature is known, antibodies (molecules that specifically bind to these surface markers) can be used to tag all the cells of a desired type and remove them from a mixed population. To improve stem cell therapy, our aim is to identify the signature markers on: (1) the stem cells that are pluripotent or especially likely to generate tumors; and (2) the tissue-specific stem cells. By then developing antibodies to the pluripotent or tumor-causing cells, we can exclude them from a group of cells to be transplanted. By developing antibodies to the tissue-specific stem cells, we can remove them from a mixture to select them for transplantation. For the second approach, we are particularly interested in targeting stem cells that develop into heart (cardiac) tissue and cells that develop into mature blood cells. As we develop ways to isolate the desired cells, we test them by transplanting them into animals and observing how they grow.
  • Thus, the first goal of our program is to develop tools to isolate pluripotent stem cells, especially those that can generate tumors in transplant recipients. To this end, we tested an antibody aimed at a pluripotent cell marker (stage-specific embryonic antigen-5 [SSEA-5]) that we previously identified. We transplanted into animals a population of stem cells that either had the SSEA-5-expressing cells removed or did not have them removed. The animals that received the transplants lacking the SSEA-5-expressing cells developed smaller and fewer teratomas (tumors consisting of an abnormal mixture of many tissues). Approaching the problem from another angle, we analyzed teratomas in animals that had received stem cell transplants. We found SSEA-5 on a small group of cells we believe to be responsible for generating the entire tumor.
  • The second goal of the program is to develop methods to selectively culture cardiac stem cells or isolate them from mixed cultures. Thus, in the last year we tested procedures for culturing pluripotent stem cells under conditions that cause them to develop into cardiac stem cells. We also tested a combination of four markers that we hypothesized would tag cardiac stem cells for separation. When these cells were grown under the proper conditions, they began to ‘beat’ and had electrical activity similar to that seen in normal heart cells. When we transplanted the cells with the four markers into mice with normal or damaged hearts, they seemed to develop into mature heart cells. However, these (human) cells did not integrate with the native (mouse) heart cells, perhaps because of the species difference. So we varied the approach and transplanted the human heart stem cells into human heart tissue that had been previously implanted in mice. In this case, we found some evidence that the transplanted cells differentiated into mature heart cells and integrated with the surrounding human cells.
  • The third goal of our project is to culture stem cells that give rise only to blood cells and test them for transplantation. In the past year, we developed a new procedure for treating cultures of pluripotent stem cells so that they differentiate into specific stem cells that generate blood cells and blood vessels. We are now working to refine our understanding and methods so that we end up with a culture of differentiated stem cells that generates only blood cells and not vessels.
  • In summary, we have discovered markers and tested combinations of antibodies for these markers that may select unwanted cells for removal or wanted cells for inclusion in stem cell transplants. We have also begun to develop techniques for taking a group of stem cells that can generate many tissue types, and growing them under conditions that cause them to develop into tissue-specific stem cells that can be used safely for transplantation.
  • Our program is focused on improving methods to purify blood-forming and heart-forming stem cells so that they can be used safely and effectively for therapy. Current methods to identify and isolate blood-forming stem cells from bone marrow and blood are efficient. In addition, we found that if blood-forming stem cells are transplanted, they create in the recipient an immune system that will tolerate (i.e., not reject) organs, tissues, or other types of tissue stem cells (e.g. skin, brain, or heart) from the same donor. Many living or recently deceased donors often cannot contribute these stem cells, so we need, in the future, a single biological source of each of the different types of stem cells (e.g., blood and heart) to change the entire field of regenerative medicine. The ultimate reason to fund embryonic stem cell and other pluripotent stem cell research is to create safe banks of predefined pluripotent cells. Protocols to differentiate these cells to the appropriate blood-forming stem cells could then be used to induce tolerance of other tissue stem cells from the same embryonic stem cell line. However, existing protocols to differentiation stem cells often lead to pluripotent cells (cells that generate multiple types of tissue), which pose a risk of generating normal tissue in the wrong location, abnormal tissue, or cancers called teratomas. To address these problems, we have concentrated our efforts to devise strategies to (a) make pluripotent cells develop into desired tissue-specific stem cells, and (b) to separate these desired cells from all other cells, including teratoma-causing cells. In the first funding period of this grant, we succeeded in raising antibodies that identify and eliminate teratoma-causing cells.
  • In the past year, we identified surface markers of cells that can only give rise to heart tissue. First we studied the genes that were activated in these cells, further confirming that they would likely give rise to heart tissue. Using antibodies against these surface markers, we purified heart stem cells to a higher concentration than has been achieved by other purification methods. We showed that these heart stem cells can be transplanted such that they integrate into the human heart, but not mouse heart, and participate in strong and correctly timed beating.
  • In the embryo, a group of early stem cells in the developing heart give rise to (a) heart cells; (b) cells lining the inner walls of blood vessels; and (c) muscle cells surrounding blood vessels. We identified cell surface markers that could be used to separate each of these subsets from each other and from their common stem cell parents. Finally, we determined that a specific chemical in the body, fibroblast growth factor, increased the growth of a group of pluripotent stem cells that give rise to more specific stem cells that produce either blood cells or the lining of blood vessels. This chemical also prevented blood-forming stem cells from developing into specific blood cells.
  • In the very early embryo, pluripotent cells separate into three distinct categories called ‘germ layers’: the endoderm, mesoderm, and ectoderm. Each of these germ layers later gives rise to certain organs. Our studies of the precursors of mesoderm (the layer that generates the heart, blood vessels, blood, etc.) led us by exclusion to develop techniques to direct ES cell differentiation towards endoderm (the layer that gives rise to liver, pancreas, intestinal lining, etc.). A graduate student before performed most of this work before he joined in our effort to find ways to make functional blood forming stem cells from ES cells. He had identified a group of proteins that we could use to sequentially direct embryonic stem cells to develop almost exclusively into endoderm, then subsets of digestive tract cells, and finally liver stem cells. These liver stem cells derived from embryonic stem cells integrated into mouse livers and showed signs of normal liver tissue function (e.g., secretion of albumin, a major protein in the blood). Using the guidelines of the protocols that generated these liver stem cells, we have now turned our attention back to our goal of generating from mesoderm the predecessors of blood-forming stem cells, and, ultimately, blood-forming stem cells.
  • In summary, we have continued to discover signals that cause pluripotent stem cells (which can generate many types of tissue) to become tissue-specific stem cells that exclusively develop into only heart, blood cells, blood vessel lining cells, cells that line certain sections of the digestive tract, or liver cells. This work has also involved determining the distinguishing molecules on the surface of various cells that allow them to be isolated and nearly purified. These results bring us closer to being able to purify a desired type of stem cell to be transplanted safely to generate only a single type of tissue.
  • The main focus of our program is to improve methods to generate pure populations of tissue-specific stem cells that form only heart tissue or blood. Such tissue-specific stem cells are necessary for developing safe and effective therapies. If injected into patients with heart damage, heart-forming stem cells might be used to regenerate healthy heart tissue. Blood-forming stem cells are capable of regenerating the blood-forming system after cancer therapy and replacing a defective blood forming-system. We showed that blood-forming stem cells from a given donor induce in the recipient permanent transplant tolerance of all organs, tissues, or other tissue stem cells from the same donor. Therefore, having a single biological source of each of the different types of stem cells (e.g., blood and heart) would revolutionize regenerative medicine.
  • Our projects involve generating tissue-specific stem cells from pluripotent stem cells (PSCs), the latter of which are stem cells that can form all tissues of the body. PSCs (which include embryonic stem cells and induced pluripotent stem cells) can turn into all types of more specialized cells in a process known as “differentiation.” Because PSCs can be grown to very large numbers, differentiating PSCs into tissue-specific stem cells could lead to banks of defined tissue stem cells for transplantation into patients—the ultimate reason to conduct PSC research.
  • However, current methods to differentiate PSCs often generate mixtures of various cell types that are unsafe for injection into patients. Therefore, generating a pure population of a desired cell type from PSC is pivotal for regenerative medicine—purity is a key concern for cell therapy as it is with medications.
  • We have invented technologies to purify desired types of cells from complex cell populations, allowing us to precisely isolate a pure population of tissue-specific stem cells from differentiating PSCs for cell therapy. For instance, in our work on heart-forming cells, we developed labels for cells that progressively give rise to heart cells. We used these labeled cells to clarify the natural, stepwise, differentiation process that leads from PSCs to heart-forming stem cells, and finally to different cells within the heart. Exploiting these technologies to isolate desired cell types, we have completed the first step of turning human PSCs into heart-forming stem cells. In the laboratory, when we transplanted these heart-forming stem cells into a human heart, they integrated with the surrounding tissue and participated in correctly timed beating. In the future we hope to deliver heart-forming stem cells into the damaged heart to regenerate healthy tissue.
  • We have also attempted to turn PSCs into blood-forming stem cells by understanding the complex process of blood formation in the early embryo. As mentioned above, if blood-forming stem cells are transplanted into patients, they create in the recipient an immune system that will tolerate (i.e., not reject) other tissues and types of tissue stem cells (e.g., for skin or heart) from the same donor. Thus, turning PSCs into blood-forming stem cells will provide the basis for all regenerative medicine, whereby the blood-forming stem cells and the needed other tissue stem cells can be generated from the same pluripotent cell line and be transplanted together.
  • In parallel studies to those above, we have turned PSCs into liver-forming stem cells. In the embryo, the liver emerges from a cell type known as endoderm, whereas the blood and heart emerge from a different cell type known as mesoderm. We learned that PSCs could only be steered to form endoderm (and subsequently, liver) by diverting them away from the path that leads to mesoderm. Through this approach, we could turn human PSCs into endoderm cells (at >99% purity) and then into liver-forming stem cells that, when injected into the mouse liver, gave rise to human liver cells. This could be of therapeutic importance for human patients with liver damage.
  • Finally, we have developed methods to deplete PSCs from mixtures of cells differentiated from PSCs, because residual PSCs in these mixtures can form tumors (known as teratomas). These methods should increase the safety of PSC-derived tissue stem cell therapy.
  • In summary, we have developed methods to turn PSCs to tissue-specific stem cells that exclusively develop into only heart, blood cells, or liver cells. This work has involved determining the distinguishing molecules on the surface of various cells that allow them to be isolated and nearly purified. These results bring us closer to being able to purify a desired type of stem cell to be transplanted safely to generate only a single type of tissue.
Funding Type: 
Basic Biology IV
Grant Number: 
RB4-06276
Investigator: 
ICOC Funds Committed: 
$1 582 606
Disease Focus: 
Heart Disease
Pediatrics
Stem Cell Use: 
iPS Cell
Cell Line Generation: 
iPS Cell
oldStatus: 
Active
Public Abstract: 
Most heart conditions leading to sudden death or impaired pumping heart functions in the young people (<35 years old) are the results of genetic mutations inherited from parents. It is very difficult to find curative therapy for these inherited heart diseases due to late diagnosis and lack of understanding in how genetic mutations cause these diseases. Using versatile stem cells derived from patients’ skin cells with genetic mutations in cell-cell junctional proteins, we have made a significant breakthrough and successfully modeled one of these inherited heart diseases within a few months in cell cultures. These disease-specific stem cells can give rise to heart cells, which allow us to discover novel abnormalities in heart energy consumption that causes dysfunction and death of these diseased heart cells. Currently, there is no disease-slowing therapy to these inherited heart diseases except implanting a shocking device to prevent sudden death. We propose here to generate more patient-specific stem cell lines in a dish from skin cells of patients with similar clinical presentations but with different mutations. With these new patient-specific stem cell lines, we will be able to understand more about the malfunctioned networks and elucidate common disease-causing mechanisms as well as to develop better and safer therapies for treating these diseases. We will also test our new therapeutic agents in a mouse model for their efficacy and safety before applying to human patients.
Statement of Benefit to California: 
Heart conditions leading to sudden death or impaired pumping functions in the young people (<35 years old) frequently are the results of genetic mutations inherited from parents. Currently, there is no disease-slowing therapy to these diseases. It is difficult to find curative therapy for these diseases due to late diagnosis. Many cell culture and animal models of human inherited heart diseases have been established but with significant limitation in their application to invent novel therapy for human patients. Recent progress in cellular reprogramming of skin cells to patient-specific induced pluripotent stem cells (iPSCs) enables modeling human genetic disorders in cell cultures. We have successfully modeled one of the inherited heart diseases within a few months in cell cultures using iPSCs derived from patients’ skin cells with genetic mutations in cell-cell junctional proteins. Heart cells derived from these disease-specific iPSCs enable us to discover novel disease-causing abnormalities and develop new therapeutic strategies. We plan to generate more iPSCs with the same disease to find common pathogenic pathways, identify new therapeutic strategies and conduct preclinical testing in a mouse model of this disease. Successful accomplishment of proposed research will make California the epicenter of heart disease modeling in vitro, which very likely will lead to human clinical trials and benefit its young citizens who have inherited heart diseases.
Progress Report: 
  • Most heart conditions leading to sudden death or impaired cardiac pumping functions in the young people (<35 years old) are the results of genetic mutations inherited from parents. It is very difficult to find curative therapy for these inherited heart diseases due to late diagnosis and lack of understanding in how genetic mutations cause these diseases. One of these inherited heart diseases is named arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). The signature features of sick ARVD/C hearts are progressive heart muscle loss and their replacement by fat and scare tissues, which can lead to lethal irregular heart rhythms and/or heart failure. We have made a significant breakthrough and successfully modeled the sick ARVD/C heart muscles within two months in cell cultures using versatile stem cells derived from ARVD/C patients’ skin cells with genetic mutations in one of the desmosomal (a specific type of cell-cell junctions in hearts) proteins, named plakophilin-2. These disease-specific stem cells can give rise to heart cells, which allow us to discover specific abnormalities in heart energy consumption of ARVD/C heart muscles that causes dysfunction and death of these diseased heart cells. In the Year 1 of this grant support, we have made and characterized additional stem cells lines from ARVD/C patients with different desmosomal mutations. We are in the process to determine if heart muscles derived from these new ARVD/C patient-specific stem cells have common disease-causing mechanisms as we had published. We found two proposed therapeutic agents are ineffective in suppressing ARVD/C disease in culture but we have identified one potential drug that suppressed the loss of ARVD/C heart cells in culture. We also started to establish a known ARVD/C mouse model for future preclinical drug testing.
  • Most heart conditions leading to sudden death or impaired cardiac pumping functions in the young people (<35 years old) are the results of genetic mutations inherited from parents. It is very difficult to find curative therapy for these inherited heart diseases due to late diagnosis and lack of understanding in how genetic mutations cause these diseases. One of these inherited heart diseases is named arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). The signature features of sick ARVD/C hearts are progressive heart muscle loss and their replacement by fat and scare tissues, which can lead to lethal heart rhythms or heart failure. We made significant breakthrough and successfully modeled sick ARVD/C heart muscles in cell cultures using versatile stem cells derived from ARVD/C patients’ skin cells with genetic mutations in desmosomal (a specific type of cell-cell junctions in hearts) proteins, e.g. plakophilin-2 (Pkp2). These disease-specific stem cells can give rise to heart cells, which allow us to discover specific abnormalities in energy consumption of ARVD/C heart muscles that lead to their dysfunction and death. In Year 2, we continued to create and characterize additional stem cells lines from ARVD/C patients with different desmosomal mutations. As we had published previously, we have confirmed that the same metabolic deregulation occurs in heart muscles derived from new ARVD/C patient-specific stem cells with different mutations from Pkp2. We further explored new microRNA-based pathogenic mechanisms and identified new classes of therapeutic agents to suppress ARVD/C pathologies in culture. We also started to establish a known ARVD/C mouse model for future preclinical drug testing.
Funding Type: 
Research Leadership 14
Grant Number: 
LA1_C14-08015
Investigator: 
Type: 
PI
ICOC Funds Committed: 
$6 368 285
Disease Focus: 
Heart Disease
Neurological Disorders
Pediatrics
Stem Cell Use: 
Embryonic Stem Cell
iPS Cell
Directly Reprogrammed Cell
Public Abstract: 
Tissues derived from stem cells can serve multiple purposes to enhance biomedical therapies. Human tissues engineered from stem cells hold tremendous potential to serve as better substrates for the discovery and development of new drugs, accurately model development or disease progression, and one day ultimately be used directly to repair, restore and replace traumatically injured and chronically degenerative organs. However, realizing the full potential of stem cells for regenerative medicine applications will require the ability to produce constructs that not only resemble the structure of real tissues, but also recapitulate appropriate physiological functions. In addition, engineered tissues should behave similarly regardless of the varying source of cells, thus requiring robust, reproducible and scalable methods of biofabrication that can be achieved using a holistic systems engineering approach. The primary objective of this research proposal is to create models of cardiac and neural human tissues from stem cells that can be used for various purposes to improve the quality of human health.
Statement of Benefit to California: 
California has become internationally renowned as home to the world's most cutting-edge stem cell biology and a global leader of clinical translation and commercialization activities for stem cell technologies and therapies. California has become the focus of worldwide attention due in large part to the significant investment made by the citizens of the state to prioritize innovative stem cell research as a critical step in advancing future biomedical therapies that can significantly improve the quality of life for countless numbers of people suffering from traumatic injuries, congenital disorders and chronic degenerative diseases. At this stage, additional investment in integration of novel tissue engineering principles with fundamental stem cell research will enable the development of novel human tissue constructs that can be used to further the translational use of stem cell-derived tissues for regenerative medicine applications. This proposal would enable the recruitment of a leading biomedical engineer with significant tissue engineering experience to collaborate with leading cardiovascular and neural investigators. The expected result will be development of new approaches to engineer transplantable tissues from pluripotent stem cell sources leading to new regenerative therapies as well as an enhanced understanding of mechanisms regulating human tissue development.
Funding Type: 
Early Translational IV
Grant Number: 
TR4-06857
Investigator: 
ICOC Funds Committed: 
$6 361 618
Disease Focus: 
Heart Disease
Stem Cell Use: 
iPS Cell
Cell Line Generation: 
iPS Cell
oldStatus: 
Active
Public Abstract: 
This project uses patient hiPSC-derived cardiomyocytes to develop a safe and effective drug to treat a serious heart health condition. This research and product development will provide a novel method for a human genetic heart disorder characterized by long delay (long Q-T interval) between heart beats caused by mutations in the Na+ channel α subunit. Certain patients are genetically predisposed to a potentially fatal arrhythmogenic response to existing drugs to treat LQT3 since the drugs have off-target effects on other important ion channels in cardiomyocytes. We will use patient-derived hiPSC-cardiomyocytes to develop a safer drug (development candidate, DC) that will retain efficacy against the "leaky" Na+-channel yet minimize off-target effects in particular against the K+ hERG channel that can be responsible for the existing drug’s pro-arrhythmic effect. Since this problem is thought to occur severely in patients with the common KCHN2 variant, K897T (~33% of the white population), removing the off-target liability addresses a serious unmet clinical need. Futher, since we propose to modify an existing drug (i.e., do drug rescue), the path from patient-specific hiPSCs to clinic might be easier than for a completely new chemical entity. Lastly, an appealing aspect is that the hiPSCs were derived from a child to test his therapy, & we aim to produce a better drug for his treatment. Our goal is to complete development of the DC and initiate IND-enabling in vivo studies.
Statement of Benefit to California: 
In the US, an estimated 850,000 adults are hospitalized for arrhythmias each year, making arrhythmias one of the top five causes of healthcare expenditures in the US with a direct cost of more than $40 billion annually for diagnosis, treatment & rehabilitation. The State of California has approximately 12% of the US population which translates to 102,000 individuals hospitalized every year for arrhythmias. Another 30,000 Californians die of sudden arrhythmic death syndrome every year. Arrhythmias are very common in older adults and because the population of California is aging, research to address this issue is important for human health and the State economy. Most serious arrhythmias affect people older than 60. This is because older adults are more likely to have heart disease & other health problems that can lead to arrhythmias. Older adults also tend to be more sensitive to the side effects of medicines, some of which can cause arrhythmias. Some medicines used to treat arrhythmias can even cause arrhythmias as a side effect. In the US, atrial fibrillation (a common type of arrhythmia that can cause problems) affects millions of people & the number is rising. Accordingly, the same problem is present in California. Thus, successful completion of this work will not only provide citizens of California much needed advances in cardiovascular health technology & improvement in health care but an improved heart drug. This will provide high paying jobs & significant tax revenue.
Progress Report: 
  • The project objective is to design, synthesize and test a sodium-channel inhibitor analog that selectively inhibits the sodium channel and not the potassium channel in patient-derived IPSCs. The strategy is to first work out the approach with wild-type human IPSCs in advance of the patient-derived cells. The status is that the milestones for Year 1 have largely been accomplished. The achievements for this reporting period include nearly locking down the IPSC protocol, developing ultra high throughput kinetic analysis of human cardiomyocytes, developing an enantioselective synthesis of sodium-channel inhibitors and analogs and identifying from a pool of only 49 compounds, a promising sodium-channel inhibitor that provides insight into selective sodium channel inhibition.
Funding Type: 
New Faculty Physician Scientist
Grant Number: 
RN3-06378
Investigator: 
ICOC Funds Committed: 
$2 930 388
Disease Focus: 
Heart Disease
Stem Cell Use: 
Embryonic Stem Cell
oldStatus: 
Active
Public Abstract: 
Because the regenerative capacity of adult heart is limited, any substantial cell loss as a result of a heart attack is mostly irreversible and may lead to progressive heart failure. Human pluripotent stem cells can be differentiated to heart cells, but their properties when transplanted into an injured heart remain unresolved. We propose to perform preclinical evaluation for transplantation of pluripotent stem cell-derived cardiac cells into the injured heart of an appropriate animal model. However, an important issue that has limited the progress to clinical use is their fate upon transplantation; that is whether they are capable of integrating into their new environment or they will function in isolation at their own pace. As an analogy, the performance of a symphony can go into chaos if one member plays in isolation from all surrounding cues. Therefore, it is important to determine if the transplanted cells can beat in harmony with the rest of the heart and if these cells will provide functional benefit to the injured heart. We plan to isolate cardiac cells derived from human pluripotent stem cells, transplant them into the model’s injured heart, determine if they result in improvement of the heart function, and perform detailed electrophysiology studies to determine their integration into the host tissue. The success of the proposed project will set the platform for future clinical trails of stem cell therapy for heart disease.
Statement of Benefit to California: 
Heart disease remains the leading cause of mortality and morbidity in the US with an estimated annual cost of over $300 billion. In California alone, more than 70,000 people die every year from cardiovascular diseases. Despite major advancement in treatments for patients with heart failure, which is mainly due to cellular loss upon myocardial injury, the mortality rate remains high. Human embryonic stem cells (hESC) and induced pluripotent stem cells (iPSC) could provide an attractive therapeutic option to treat patients with damaged heart. We propose to isolate heart cells from hESCs and transplant them in an injured animal model's heart and study their fate. In the process, we will develop reagents that can be highly valuable for future research and clinical studies. The reagents generated in these studies can be patented forming an intellectual property portfolio shared by the state and the institution where the research is carried out. Most importantly, the research that is proposed in this application could lead to future stem cell-based therapies that would restore heart function after a heart attack. We expect that California hospitals and health care entities will be first in line for trials and therapies. Thus, California will benefit economically and it will help advance novel medical care.
Progress Report: 
  • Identification and isolation of pure cardiac cells derived from human pluripotent stem cells has proven to be a difficult task. We have designed a method to genetically engineer human embryonic stem cells (hESCs) to harbor a label that is expressed during sequential maturation of cardiac cells. This will allow us to prospectively isolate cardiac cells at different stages of development for further characterization and transplantation. Using this method, we have screened proteins that are expressed on the surface of cells as markers. Using antibodies against these surface markers allows for isolation of these cells using cell sorting techniques. Thus far, we have identified two surface markers that can be used to isolate early cardiac progenitors. Using these markers, we have enriched for cardiac cells from differentiating hESCs and have characterized their properties in the dish as well as in small animals. We plan to transplant these cells in large animal models and monitor their survival, expansion and their integration into the host myocardium. Molecular imaging techniques are used to track these cells upon transplantation.
Funding Type: 
New Faculty Physician Scientist
Grant Number: 
RN3-06455
Investigator: 
Name: 
Type: 
PI
ICOC Funds Committed: 
$3 004 315
Disease Focus: 
Heart Disease
Stem Cell Use: 
iPS Cell
oldStatus: 
Active
Public Abstract: 
Despite therapeutic advances, cardiovascular disease remains a leading cause of mortality and morbidity in California. Regenerative therapies that restore normal function after a heart attack would have an enormous societal and financial impact. Although very promising, regenerative cardiac cell therapy faces a number of challenges and technological hurdles. Human induced pluripotent stem cells (hiPSC) allow the potential to deliver patient specific, well-defined cardiac progenitor cells (CPC) for regenerative clinical therapies. We propose to translate recent advances in our lab into the development of a novel, well-defined hiPSC-derived CPC therapy. All protocols will be based on clinical-grade, FDA-approvable, animal product-free methods to facilitate preclinical testing in a large animal model. This application will attempt to translate these findings by: -Developing techniques and protocols utilizing human induced pluripotent stem cell-derived cardiac progenitor cells at yields adequate to conduct preclinical large animal studies. -Validation of therapeutic activity will be in small and large animal models of ischemic heart disease by demonstrating effectiveness of hiPSC-derived CPCs in regenerating damaged myocardium post myocardial infarction in small and large animal models. This developmental candidate and techniques described here, if shown to be a feasible alternative to current approaches, would offer a novel approach to the treatment of ischemic heart disease.
Statement of Benefit to California: 
Cardiovascular disease remains the leading cause of morbidity and mortality in California and the US costing the healthcare system greater than 300 billion dollars a year. Although current therapies slow progression of heart disease, there are few options to reverse or repair the damaged heart. The limited ability of the heart to regenerate following a heart attack results in loss of function and heart failure. Human clinical trials testing the efficacy of adult stem cell therapy to restore mechanical function after a heart attack, although promising, have had variable results with modest improvements. The discovery of human induced pluripotent stem cells offers a potentially unlimited renewable source for patient specific cardiac progenitor cells. However, practical application of pluripotent stem cells or their derivatives face a number of challenges and technological hurdles. We have demonstrated that cardiac progenitor cells, which are capable of differentiating into all cardiovascular cell types, are present during normal fetal development and can be isolated from human induced pluripotent stem cells. We propose to translate these findings into a large animal pre-clinical model and eventually to human clinical trials. This could lead to new therapies that would restore heart function after a heart attack preventing heart failure and death. This will have tremendous societal and financial benefits to patients in California and the US in treating heart failure.
Progress Report: 
  • Cardiovascular disease remains to be a major cause of morbidity and mortality in California and the United States. Despite the best medical therapies, none address the issue of irreversible myocardial tissue loss after a heart attack and thus there has been a great interest to develop approaches to induce regeneration. Our lab has focused on harvesting the full potential of patient specific induced pluripotent stem cells (iPSCs) to use to attempt to regenerate the damaged tissue. We believe that these iPSCs can be potentially used in the future to generate sufficient number of cells to be implanted in the damaged heart to regenerate the lost tissue post heart attack. Our lab has studied how these cardiac progenitors evolve in the developing heart and applied our finding to iPSCs to recapitulate the cardiac progenitors to ultimately use in clinical therapies. We have successfully derived these cardiac progenitors from patient derived iPSCs in a clinical grade fashion to ensure that we can apply same protocols in the future to clinical use if we are successful in demonstrating the efficacy of this therapy in our translational large animal studies that we will be conducting.
Funding Type: 
Basic Biology IV
Grant Number: 
RB4-06035
Investigator: 
Name: 
Type: 
PI
ICOC Funds Committed: 
$1 708 560
Disease Focus: 
Heart Disease
Stem Cell Use: 
Directly Reprogrammed Cell
Cell Line Generation: 
iPS Cell
oldStatus: 
Active
Public Abstract: 
Recently, we devised and reported a new regenerative medicine paradigm that entails temporal/transient overexpression of induced pluripotent stem cell based reprogramming factors in skin cells, leading to the rapid generation of “activated” cells, which can then be directed by specific growth factors and small molecules to “relax” back into various defined and homogenous tissue-specific precursor cell types (including nervous cells, heart cells, blood vessel cells, and pancreas and liver progenitor cells), which can be expanded and further differentiated into mature cells entirely distinct from fibroblasts. In this proposal, combined with small molecules that can functionally replace reprogramming transcription factors as well as substantially improve reprogramming efficiency and kinetics, we aim to further develop and mechanistically characterize chemically defined, non-integrating approaches (e.g., mRNA, miRNA, episomal plasmids and/or small molecule-based) to robustly and efficiently reprogram skin fibroblast cells into expandable heart precursor cells. Specifically, we will: determine if we can use non-integrating methods to destabilize human fibroblasts and facilitate their direct reprogramming into the heart precursor cells; characterize of heart cells generated by the direct programming methods, both in the tissue culture dish and in a mouse model of heart attack; and characterize newly identified reprogramming enhancing small molecules mechanistically.
Statement of Benefit to California: 
This study will develop and mechanistically characterize a new method of generating safe patient specific heart cells that could be useful in treating heart failure which afflicts millions of Californians and accounts for billions of dollars in healthcare spending annually. Additionally, the small molecules discovered in this study could be good candidates for future drug development as well as being broadly useful for other regenerative medicine applications. These advances could also be a platform for new personalized medicine/ cell banking businesses which could bring economic growth in addition to improving the health of Californians.
Progress Report: 
  • During the reporting period, we have made very significant progress toward the following research aims: (1) Using the Oct4-based reprogramming assay system established, we were able to screen for and identify small molecules that can replace the other three genes in the Cell-Activation and Signaling-Directed (CASD) lineage conversion paradigm for reprogramming fibroblasts into cardiac lineage. (2) Using in-depth assays, we have examined the process using lineage-tracing methods and characterized those Oct4/small molecules-reprogrammed cardiac cells in vitro. (3) Most importantly, we were able to identify a baseline condition that appears to reprogram human fibroblasts into cardiac cells using defined conditions.
  • Cardiomyocyte-like cells can be reprogrammed from somatic fibroblasts by combinations of genes in vitro1 and in vivo, providing a new avenue for cardiac regenerative therapy. However, transdifferentiating human cells to generate fully functional cardiomyocytes remains a challenge. Moreover, genetic manipulations with multiple factors used in such conventional strategies pose safety, efficacy, and technical concerns that may limit their clinical potential. In the work funded by CIRM we identified and demonstrated that functional cardiomyocytes can be rapidly and efficiently generated from fibroblasts by a combination of small molecules. These cardiomyocytes express characteristic cardiac markers, have a well-organized sarcomeric structure, contract spontaneously, and respond to pharmacological modulations. They closely resemble cardiomyocytes in their global gene expression profiles, and electrophysiological properties. This novel pharmacological reprogramming approach may have important implications in cardiac regenerative medicine.
Funding Type: 
Basic Biology III
Grant Number: 
RB3-05129
Investigator: 
Name: 
Institution: 
Type: 
PI
ICOC Funds Committed: 
$1 425 600
Disease Focus: 
Heart Disease
Stem Cell Use: 
iPS Cell
Cell Line Generation: 
iPS Cell
oldStatus: 
Active
Public Abstract: 
Familial hypertrophic cardiomyopathy (HCM) is the leading cause of sudden cardiac death in young people, including trained athletes, and is the most common inherited heart defect. Until now, studies in humans with HCM have been limited by a variety of factors, including variable environmental stimuli which may differ between individuals (e.g., diet, exercise, and lifestyle), the relative difficulty in obtaining human cardiac samples, and inadequate methods of maintaining human heart tissue in cell culture systems. Cellular reprogramming methods that enable derivation of human induced pluripotent stem cells (hiPSCs) from adult cells, which can then be differentiated into cardiomyocytes (hiPSC-CMs), are a revolutionary tool for creating disease-specific cell lines that may lead to effective targeted therapies. In this proposal, we will derive hiPSC-CMs from patients with HCM and healthy controls, then perform a battery of functional and molecular tests to determine the presence of cardiomyopathic disease and associated abnormal molecular programs. With these preliminary studies, we believe hiPSC-CMs with HCM phenotype will dramatically enhance the ability to perform future high-throughput drug screens, evaluate gene and cell therapies, and assess novel electrophysiologic interventions for potential new therapies of HCM. Because HCM is not a rare disease but rather the leading cause of inherited heart defects, we believe the findings here should have broad clinical and scientific impact toward understanding the molecular and cellular basis of HCM.
Statement of Benefit to California: 
Familial hypertrophic cardiomyopathy (HCM) is the leading cause of sudden cardiac death in young people and is the most common inherited heart defect. In this study, we will generate hiPSC-derived cardiomyocytes from patients with HCM, then perform a number of functional, molecular, bioinformatic, and imaging analyses to determine the extent and nature of cardiomyopathic disease. We believe hiPSC-CMs with HCM phenotype will dramatically enhance the ability to perform future high-throughput drug screens, evaluate gene and cell therapies, and assess electrophysiologic interventions for potential novel therapies of HCM. The experiments outlined are pertinent and central to the overall mission of CIRM, which seeks to explore the use of stem cell platforms to yield novel mechanistic insights into the molecular and cellular basis of disease. Because HCM is not an orphan disease, but rather the leading cause of sudden cardiac death in young people, we believe the research findings will benefit the state of California and its citizens.
Progress Report: 
  • Familial hypertrophic cardiomyopathy (HCM) is the leading cause of sudden cardiac death in young people, including trained athletes, and is the most common inherited heart defect. In this proposal, we will generate human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) from patients with HCM. The specific aims are as follow:
  • Specific Aim 1: Generate iPSCs from patients with HCM and healthy controls.
  • Specific Aim 2: Determine the extent of disease by performing molecular and functional analyses of hiPSC-CMs.
  • Specific Aim 3: Rescue the molecular and functional phenotypes using zinc finger nuclease (ZFN) technology.
  • Over the past year, we have now derived iPSCs from a 10-patient family cohort with the MYH7 mutation. Established iPSC lines from all subjects were differentiated into cardiomyocyte lineages (iPSC-CMs) using standard 3D EB differentiation protocols. We found hypertrophic iPSC-CMs exhibited features of HCM such as cellular enlargement and multi-nucleation beginning in the sixth week following induction of cardiac differentiation. We also found hypertrophic iPSC-CMs demonstrated other hallmarks of HCM including expression of atrial natriuretic factor (ANF), elevation of β-myosin/α-myosin ratio, calcineurin activation, and nuclear translocation of nuclear factor of activated T-cells (NFAT) as detected by immunostaining. Blockade of calcineurin-NFAT interaction in HCM iPSC-CMs by cyclosporin A (CsA) and FK506 reduced hypertrophy by over 40%. In the absence of inhibition, NFAT-activated mediators of hypertrophy such as GATA4 and MEF2C were found to be significantly upregulated in HCM iPSC-CMs beginning day 40 post-induction of cardiac differentiation, but not prior to this point. Taken together, these results indicate that calcineurin-NFAT signaling plays a central role in the development of the HCM phenotype as caused by the Arg663His mutation.
  • Familial hypertrophic cardiomyopathy (HCM) is the leading cause of sudden cardiac death in young people, including trained athletes, and is the most common
  • inherited heart defect. In this proposal, we will generate and characterize human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) from patients with HCM. The
  • specific aims are as follow:
  • Specific Aim 1: Generate iPSCs from patients with HCM and healthy controls.
  • Specific Aim 2: Determine the extent of disease by performing molecular and functional analyses of hiPSC-CMs.
  • Specific Aim 3: Rescue the molecular and functional phenotypes using zinc finger nuclease (ZFN) technology.
  • Over the past year, we have characterized the pathological phenotypes from iPSCs derived from a 10-patient family cohort with the MYH7 mutation.
  • We've differentiated all stablished iPSC lines from all subjects into cardiomyocyte using a modified protocol from that published by Palacek in PNAS 2011. This protocol increased the yield of cardiomyocytes significantly to consistently greater than 70% beating cardiomyocytes. We then tested the electrophysiological properties of iPSC-CMs from control and patients with HCM and found that both control and patient iPSC-CM display atrial, ventricular and nodal-like electrical waveforms by whole cell patch clamping. However, by day 30, a large subfraction (~40%) of the HCM iPSC-CM exhibit arrhythmic waveforms including delayed after-depolarizations (DADs) compared with control (~5.1%). In addition we found that treatment of HCM hiPSC-CM with positive inotropic agents (beta-adrenergic agonist - isoproterenal) for 5 days caused an earlier increase in cell size by 1.7 fold as compared to controls and significant increase in irregular calcium transients. Furthermore, we found that HCM iPSC-CMs exhibited frequent arrhythmia due to their increased intracellular calcium level by 30% at baseline. These HCM iPSC-CM also exhibited decreased calcium release by the sarcoplasmic reticulum. These findings emphasize the role of irregular calcium recycling in the pathogenesis of HCM. To confirm that the regulation of myocyte calcium is the key to HCM pathogenesis, we treated several lines from multiple HCM patients with calcium channel blocker (verapamil/diltiazem) and found that this treatment significantly ameliorated all aspects of the HCM phenotype including myocyte hypertrophy, calcium handling abnormalities, and arrhythmia. These finding supports the use of calcium channel blockers in patients with HCM and encourages further clinical studies in HCM patients using these agents.
  • Familial hypertrophic cardiomyopathy (HCM) is the leading cause of sudden cardiac death in young people, including trained athletes, and is the most common
  • inherited heart defect. In this proposal, we will generate human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) from patients with HCM. The
  • specific aims are as follow:
  • Specific Aim 1: Generate iPSCs from patients with HCM and healthy controls.
  • Specific Aim 2: Determine the extent of disease by performing molecular and functional analyses of hiPSC-CMs.
  • Specific Aim 3: Rescue the molecular and functional phenotypes using zinc finger nuclease (ZFN) technology.
  • Over the past year, we have characterized iPSC-CMs from a 10-patient family cohort with the MYH7 mutation using standard 3D EB differentiation protocols.
  • We found normal and hypertrophic iPSC-CMs were predictive as in vitro model for arrhythmia screening using microelectroarrays and single cell patch-clamping
  • analysis. For example, we found that administration of catecholamine drug norepinephrine causes the formation of torsade de point which is a lethan arrhythmia.
  • This recapitulates the phenotype in patients with HCM receiving catecholamine drugs. We also found increase in torsade formation when the iPSC-CMs are treated
  • with hERG blockers that are also known to cause increases in arrhythmia in HCM patients. We believe the use of hiPSC-CM from healthy individuals and patients with
  • genetic heart disease can help predict the potential arrhythmic risk in existing or new drug agents that are undergoing FDA evaluation.
  • We have also generated HCM mutations in lines of normal iPSC to determine whether these mutant lines will exhibit HCM phenotype. This would satisfy the Koch's postulate
  • with regards to the role of the mutant DNA sequence on HCM manifestation. We found, using TALEN and piggyBac transposon technologies that genome edited can be generated
  • to carry R663H mutation in the MYH7 gene and that these genome edited iPSC-CM recapitulated the HCM phenotype associated with the R663H mutation such as sarcomere
  • disassembly and intracellular calcium abnormalities as well as contractile arrhythmias. We have also corrected mutant HCM human iPSC from patients with MYH7 R663H mutation
  • and show that these corrected iPSC-CM exhibit normal sarcomeric phenotype with smaller cell size and reduced calcium transient irregularities.
Funding Type: 
hiPSC Derivation
Grant Number: 
ID1-06557
Investigator: 
Type: 
PI
ICOC Funds Committed: 
$16 000 000
Disease Focus: 
Developmental Disorders
Genetic Disorder
Heart Disease
Infectious Disease
Alzheimer's Disease
Neurological Disorders
Autism
Respiratory Disorders
Vision Loss
Cell Line Generation: 
iPS Cell
oldStatus: 
Active
Public Abstract: 
Induced pluripotent stem cells (iPSCs) have the potential to differentiate to nearly any cells of the body, thereby providing a new paradigm for studying normal and aberrant biological networks in nearly all stages of development. Donor-specific iPSCs and differentiated cells made from them can be used for basic and applied research, for developing better disease models, and for regenerative medicine involving novel cell therapies and tissue engineering platforms. When iPSCs are derived from a disease-carrying donor; the iPSC-derived differentiated cells may show the same disease phenotype as the donor, producing a very valuable cell type as a disease model. To facilitate wider access to large numbers of iPSCs in order to develop cures for polygenic diseases, we will use a an episomal reprogramming system to produce 3 well-characterized iPSC lines from each of 3,000 selected donors. These donors may express traits related to Alzheimer’s disease, autism spectrum disorders, autoimmune diseases, cardiovascular diseases, cerebral palsy, diabetes, or respiratory diseases. The footprint-free iPSCs will be derived from donor peripheral blood or skin biopsies. iPSCs made by this method have been thoroughly tested, routinely grown at large scale, and differentiated to produce cardiomyocytes, neurons, hepatocytes, and endothelial cells. The 9,000 iPSC lines developed in this proposal will be made widely available to stem cell researchers studying these often intractable diseases.
Statement of Benefit to California: 
Induced pluripotent stem cells (iPSCs) offer great promise to the large number of Californians suffering from often intractable polygenic diseases such as Alzheimer’s disease, autism spectrum disorders, autoimmune and cardiovascular diseases, diabetes, and respiratory disease. iPSCs can be generated from numerous adult tissues, including blood or skin, in 4–5 weeks and then differentiated to almost any desired terminal cell type. When iPSCs are derived from a disease-carrying donor, the iPSC-derived differentiated cells may show the same disease phenotype as the donor. In these cases, the cells will be useful for understanding disease biology and for screening drug candidates, and California researchers will benefit from access to a large, genetically diverse iPSC bank. The goal of this project is to reprogram 3,000 tissue samples from patients who have been diagnosed with various complex diseases and from healthy controls. These tissue samples will be used to generate fully characterized, high-quality iPSC lines that will be banked and made readily available to researchers for basic and clinical research. These efforts will ultimately lead to better medicines and/or cellular therapies to treat afflicted Californians. As iPSC research progresses to commercial development and clinical applications, more and more California patients will benefit and a substantial number of new jobs will be created in the state.
Progress Report: 
  • First year progress on grant ID1-06557, " Generation and Characterization of High-Quality, Footprint-Free Human Induced Pluripotent Stem Cell (iPSC) Lines From 3000 Donors to Investigate Multigenic Disease" has met all agreed-upon milestones. In particular, Cellular Dynamics International (CDI) has taken lease to approximately 5000 square feet of lab space at the Buck Institute for Research on Aging in Novato, CA. The majority of this space is located within the new CIRM-funded Stem Cell Research Building at the Buck Institute and was extensively reconfigured to meet the specific needs of this grant. All equipment, including tissue culture safety cabinets and incubators, liquid-handling robotics, and QC instrumentation have been installed and qualified. A total of 16 scientists have been hired and trained (13 in Production and 3 in Quality) and more than 20 Standard Operating Procedures (SOPs) have been developed and approved specifically for this project. These SOPs serve to govern the daily activities of the Production and Quality staff and help ensure consistency and quality throughout the iPSC derivation and characterization process. In addition, a Laboratory Information Management System (LIMS) had to be developed to handle the large amount of data generated by this project and to track all samples from start to finish. The first and most important phase of this LIMS project has been completed; additional functionalities will likely be added to the LIMS during the next year, but completion of phase 1 will allow us to enter full production mode on schedule in the first quarter of year 2. Procedures for the shipping, infectious disease testing, and processing of donor samples were successfully implemented with the seven Tissue Collectors. To date, over 700 samples have been received from these Tissue Collectors and derivation of the first 50 patient-derived iPSC lines has been completed on schedule. These cells have been banked in the Coriell BioRepository, also located at the Buck Institute. The first Distribution Banks will be available for commercial release during year 2.

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