Heart Disease

Coding Dimension ID: 
295
Coding Dimension path name: 
Heart Disease

Human Induced Pluripotent Stem Cell-Derived Cardiovascular Progenitor Cells for Cardiac Cell Therapy.

Funding Type: 
New Faculty Physician Scientist
Grant Number: 
RN3-06455
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.

Antibody tools to deplete or isolate teratogenic, cardiac, and blood stem cells from hESCs

Funding Type: 
Tools and Technologies II
Grant Number: 
RT2-02060
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.

Induction of Pluripotent Stem Cell-Derived Pacemaking Cells

Funding Type: 
Basic Biology IV
Grant Number: 
RB4-05764
ICOC Funds Committed: 
$1 334 880
Disease Focus: 
Heart Disease
Stem Cell Use: 
iPS Cell
oldStatus: 
Active
Public Abstract: 
Currently, over 350,000 patients per year with abnormal heart rhythm receive electronic pacemakers to restore their normal heart beat. Electronic pacemakers do not respond to the need for changing heart rate in situations such as exercise and have limited battery life, which can be resolved with biopacemakers. In this proposed project, we will examine methods that improve the generation of pacemaking cells from human induced pluripotent stem cells as candidates for biopacemaker.
Statement of Benefit to California: 
This proposal aims to generate pacemaking cells through facilitated differentiation from human induced pluripotent stem cells that may serve as biopacemakers. Over 350,000 patients a year in the U.S. require the implantation of an electronic pacemaker to restore their heart rhythm, with more than 3 million patients that are dependent on this device. At the cost of $58K per pacemaker implantation, the healthcare burden is greater than $20 billion a year. However, the cost associated with these electronic devices does not end with surgery for implantation. These devices require a battery change every 5 to 10 years that involve another surgical procedure. With California being the most populated state, this can be very costly to the Californians. It also does not give the patients the quality of life by having to endure repeated surgeries. The possibility of biopacemaker that requires no future battery replacements and other advantages such as physiological adaptation to the active state of the patient make biopacemakers a truly desirable alternative to electronic devices. Moreover, one in 20,000 infants or preemies with congenital sinoatrial node dysfunction are also inappropriate candidates to receive electronic pacemakers because they are physically too small and require a proportional increase in the length of pacing leads with their significant growth rate. Therefore, there is a great need for biopacemakers that may overcome the deficiencies of electronic devices.
Progress Report: 
  • This goal of this project is to improve the yield of pacemaking cells from human induced pluripotent stem cells (hiPSCs) that can be used to engineer biopacemaker. We have demonstrated that manipulation of the membrane potential of hiPSCs using small molecules can upregulate genes of the desired cell type progressing to the pacemaking cells at all differentiation stages. In the differentiation stage to mesodermal cells, treated hiPSCs exhibit a membrane potential that is further down the differentiation path than untreated control. This source was this change was examined.
  • We continued our work in improving the yield of pacemaking cells from human induced pluripotent stem cells (hiPSCs) that can be used to engineer biopacemakers. The ion channel isoform responsible for the induced membrane potential changes in hiPSCs and their differentiating cardiac progeny was determined. We focused on optimizing the duration and the timing of membrane potential manipulation in improving the efficiency of pro-pacemaking cardiac progenitor cells and pacemaking cells.

Extracellular Matrix Bioscaffold Augmented with Human Stem Cells for Cardiovascular Repair

Funding Type: 
Early Translational III
Grant Number: 
TR3-05626
ICOC Funds Committed: 
$4 939 140
Disease Focus: 
Heart Disease
Stem Cell Use: 
Adult Stem Cell
oldStatus: 
Active
Public Abstract: 
An estimated 16.3 million Americans suffer from coronary heart disease. Every 25 seconds, someone has a coronary event and every minute, someone dies from one. Treatment for coronary heart disease has improved greatly in recent years, yet 1 in 6 deaths in the US in 2007 was still caused by this terrible disease. Stem cells have been used as an supplemental form of treatment but they have been most effective for patients treated immediately after their first heart attack. Unfortunately, stem cell therapy for chronic heart disease and heart failure has been less successful. With current delivery methods for stem cells into the heart, most are washed away quickly, whereas our device will hold them in the area that needs repair. With this project we are testing a novel approach to improve the benefits of stem cell therapy for patients suffering from chronic heart disease. By applying a type of bone marrow stem cells known to enhance tissue repair (mesenchymal stem cells) to a biological scaffold, we hope to greatly amplify the beneficial properties of both the stem cells and the biological scaffold. This device will be implanted onto an appropriate preclinical model that have been treated so as to mirror the chronic heart disease seen in humans. We predict that this novel device will heal the damaged heart and improve its function to pave the way for a superior treatment option for the thousands of Americans for whom the unlikely prospect of a heart transplant is currently the only hope.
Statement of Benefit to California: 
Heart disease is the number one cause of death and disability in California and in the US as a whole. An estimated 16.3 million Americans over the age of 20 suffer from coronary heart disease (CHD) with an estimated associated cost of $177.5 billion and CHD accounted for 1 in 6 deaths in the US in 2007. Advances in treatment have decreased early mortality but consequently lead to an increase in the incidences of heart failure (HF). Patients with HF have a 50 percent readmission rate within six months, which is a heavy cost both in terms of quality of life and finances. The high cost of caring for patients with HF results primarily from frequent hospital readmissions for exacerbations. The need for efficient treatment strategies that address the underlying cause, massive loss of functional myocardium, is yet to be met. We believe that present project proposal, development of a combined mesenchymal stem cell and extra cellular matrix scaffold device, will lead to improved standards of care for patients suffering from chronic myocardial infarction who are thus at risk of developing HF. By not only retarding disease progression but by actually restoring cardiac function, we believe that the proposed project will have a tremendous impact on both the cost of care as well as the quality of life for large groups of Californians and patients worldwide for whom the improbable prospect of heart transplantation is the only curative treatment option available.
Progress Report: 
  • Heart disease is a major cause of death and disability in the US, accounting for 1 in every 4 deaths and costing more than 100 billion annually. While significant improvements have been made towards treating and managing heart disease, we are still not able to effectively return the heart to a healthy state and cure the patients. With our project we have set out to develop a novel strategy for not only halting the disease progression but to reverse the devastating effect on the function of the heart. By combining bone marrow mesenchymal stromal cells with a biological scaffold material, we hope to create a patch for the heart that will support and regenerate the diseased tissue to the point where the patient will be relieved of the burden of their disease and have a markedly improve quality of life. We have in the past year made significant advances toward establishing an animal disease model in which we can study novel ways of treating heart disease. We have in the same time isolated and characterized cells that reside in the bone marrow and that have the potential to heal the diseased tissue by improving blood flow, minimize scarring and generally promoting recovery of the heart function. We have studies these cells under when grown under different conditions and found their ability to mediate tissue regeneration to be highly dependent on their local environments. We are currently trying to identify the optimal combination of cells and microenvironment that may achieve maximal regenerative effect in our disease model and ultimately help our patient combat their heart disease.
  • Cardiovascular diseases remain the leading cause of death and disability in the United States. Even with optimal intervention, patients that suffer from an initial coronary event are prone to development of ischemic heart disease (IHD). Current therapies for IHD such medication, percutaneous coronary intervention, anticoagulants, and coronary artery bypass grafting are incapable of rescuing necrotic tissue and recovering normal cardiac function. The only current curative therapy is heart transplantation; however donor organ supply is severely limited and the vast majority of patients die from congestive heart failure while on the transplant waiting list.
  • Cellular therapies are being explored as a potential cure for IHD. In the majority of these trials, cells are injected in suspension into either vasculature or directly into the ischemic myocardium. Clinical outcomes have clearly demonstrated the safety of these cell based therapies. However, clinical improvements have been modest at best, ostensibly due to poor long term donor cells survival and retention.
  • Mesenchymal stem cells (MSCs) are an attractive allogeneic stem cell source for cardiac regenerative therapies. MSCs are considered to be immunoprivileged in that they modulate and evade the host immune microenvironment, thus making them ideal candidates for allogeneic transplantation. MSCs also facilitate regeneration by secreting angiogenic and chemotactic factors that facilitate new blood vessel formation and recruitment of host stem and progenitor cells.
  • Porcine small intestinal submucosa extracellular matrix (SIS-ECM) is a bioscaffold produced from the small intestine of pigs. It has been found to exert a variety of beneficial pro-regenerative functions, hereunder modulating the chemotactic and immune response and releasing large amounts of pro-angiogenic factors. SIS-ECM is ideal in surgical applications as a replacement for synthetic materials in that it facilitates site specific regeneration and resorbs into native tissue without a need for later removal.
  • The overall goal of this project is to generate a MSC seeded SIS-ECM device for the treatment of IHD. The hypothesis is that the combination of MSCs and SIS-ECM will produce a device with regenerative properties that exceed either component alone. We will with this project develop a porcine myocardial infarct (MI) model that mimics the hallmarks of the human disease. We will then test the proposed device in this model and monitor functional improvement as compared to control animals and animals receiving cells or SIS-ECM alone. We will also verify in vitro that human and porcine MSCs are phenotypically and functionally equivalent to confirm that the results obtained in our porcine model are relevant for the human setting with a high probability. Finally, we will explore mechanisms of action in vitro in relevant assay and in vivo in rat myocardial infarct models.
  • Major accomplishments in this reporting period:
  • 1. We successfully established a reproducible porcine chronic MI model (CMI) and an acute myocardial infarct (AMI) model. We tested two routes of delivery, epicardial patch and intramyocardial injection. We also optimized orientation and seeding density of the device as well as telemetry implantation in a non-injury porcine sternotomy model. We conclude that the CMI model is well suited for the upcoming studies where we will transplantation our device as an epicardial patch with the MSC seeded side facing the epicardium and seeded below maximal capacity to be the favored approach.
  • 2. We found that MSCs from human and porcine bone marrow samples can readily be isolated, expanded and banked using identical methodology. We created master cell banks from three donors for each species. We additionally generated working cell banks of eGFP and Luciferase overexpressing MSCs for both species. We furthermore confirmed, again using identical methodology that both human and porcine MSCs are analogous with respect to tri-lineage potential, cells surface marker expression and karyotype. Moreover, these major MSC hallmarks are not altered in response to seeding onto SIS-ECM. Finally, we are completing similar studies for rat MSCs
  • 3. We have confirmed that human and porcine MSCs are analogous in the expression pattern of angiogenic factors. We also found that the migratory effect of culture supernatants from human or porcine MSCs seeded onto plastic or SIS-ECM is comparable. Additionally, we found that secretion levels of inflammatory cytokines and in vitro tube formation from culture supernatant was comparable for human MSCs seeded on plastic or SIS-ECM. We furthermore established an AMI model in both immune competent and immune deficient rats. Using these models we have demonstrated significant disease modifying effects of the rat DC analogue as compared to SIS-ECM or MSCs alone. Finally we found improved cell retention at the site of implant for our human DC in the immune deficient SCID rat AMI model.

Direct Cardiac Reprogramming for Heart Regeneration

Funding Type: 
Early Translational III
Grant Number: 
TR3-05593
ICOC Funds Committed: 
$6 319 110
Disease Focus: 
Heart Disease
Stem Cell Use: 
Directly Reprogrammed Cell
oldStatus: 
Active
Public Abstract: 
Heart disease is a leading cause of mortality. The underlying pathology is typically loss of heart muscle cells that leads to heart failure. Because heart muscle has little or no regenerative capacity after birth, current therapeutic approaches are limited for the over 5 million Americans who suffer from heart failure. Our recent findings regarding direct reprogramming of a type of structural cell of the heart, called fibroblasts, into cardiac muscle-like cells using just three genes offers a novel approach to achieving cardiac regeneration. 50% of cells in the human heart are cardiac fibroblasts, providing a potential source of new heart muscle cells for regenerative therapy. We simulated a heart attack in mice by blocking the coronary artery, and have been able to reprogram existing mouse cardiac fibroblasts in to new muscle by delivering the three genes into the heart. We found a significant reduction in scar size and an improvement in cardiac function that persists after injury. The reprogramming of cells in the intact organ was more complete than in cells in a dish. We now propose to develop the optimal gene therapy approach to introduce cardiac reprogramming genes into the heart, to establish the optimal delivery approach to administer virus encoding cardiac reprogramming factors that results in improvement in cardiac function in a preclinical model of cardiac injury, and to establish the safety profile of in vivo cardiac reprogramming in a preclinical model.
Statement of Benefit to California: 
This research will benefit the state of California and its citizens by helping develop a new therapeutic approach to cardiac regeneration. Heart disease is a leading cause of death in adults and children in California, but there is no current treatment that can promote cardiac regeneration. This proposal will lay the groundwork for a clinical trial that could result in generation of new heart muscle cells from within the heart. If successful, there is potential economic benefit in terms of productive lives saved and in the commercialization of this technology.
Progress Report: 
  • Heart disease is a leading cause of mortality. The underlying pathology is typically loss of heart muscle cells that leads to heart failure. Because heart muscle has little or no regenerative capacity after birth, current therapeutic approaches are limited for the over 5 million Americans who suffer from heart failure. Our recent findings regarding direct reprogramming of a type of structural cell of the heart, called fibroblasts, into cardiac muscle-like cells using just three genes offers a novel approach to achieving cardiac regeneration. 50% of cells in the human heart are cardiac fibroblasts, providing a potential source of new heart muscle cells for regenerative therapy. We simulated a heart attack in mice by blocking the coronary artery, and have been able to reprogram existing mouse cardiac fibroblasts into new muscle by delivering the three genes into the heart. We found a significant reduction in scar size and an improvement in cardiac function that persists after injury. The reprogramming of cells in the intact organ was more complete than in cells in a dish. We now identified a combination of factors that reprogram human and pig cardiac fibroblasts and are optimizing a gene therapy approach to introduce cardiac reprogramming genes into the heart of pigs. In a pig model of cardiac injury, these factors were able to convert non-muscle cells into new muscle in the area of injury. We also found a viral vector that can preferentially infect the fibroblasts compare to the muscle cells. We are now in a position to test for functional improvement in pigs.
  • Heart disease is a leading cause of mortality. The underlying pathology is typically loss of heart muscle cells that leads to heart failure. Because heart muscle has little or no regenerative capacity after birth, current therapeutic approaches are limited for the over 5 million Americans who suffer from heart failure. Our recent findings regarding direct reprogramming of a type of structural cell of the heart, called fibroblasts, into cardiac muscle-like cells using just three genes offers a novel approach to achieving cardiac regeneration. We simulated a heart attack in mice by blocking the coronary artery, and have regenerated damaged hearts by converting existing mouse cardiac fibroblasts into new muscle by delivering the three genes into the heart. We have found that a combination of the three genes used in mice plus two additional factors were sufficient to identified to reprogram human and pig cardiac fibroblasts and are optimizing a gene therapy approach to introduce cardiac reprogramming genes into the heart of pigs. In a pig model of cardiac injury, we identified the optimal combination of factors that was able to convert non-muscle cells into new muscle in the area of injury. We have completed a pilot study of these five factors for functional improvement using MRI to measure cardiac output 3 days after injury and 2 months after treatment with the reprogramming factors. We also found a viral vector that can preferentially infect the fibroblasts compare to the muscle cells and have confirmed this activity. We are now testing for functional improvement in pigs using various viral vectors.

Human Embryonic Stem Cell-Derived Cardiomyocytes for Patients with End Stage Heart Failure

Funding Type: 
Disease Team Therapy Development - Research
Grant Number: 
DR2A-05394
ICOC Funds Committed: 
$19 999 899
Disease Focus: 
Heart Disease
Stem Cell Use: 
Embryonic Stem Cell
oldStatus: 
Active
Public Abstract: 
Patients with end-stage heart failure have a 2-year survival rate of only 50% with conventional medical therapy. This dismal survival rate is actually significantly worse than patients with AIDS, liver cirrhosis, stroke, and other comparable debilitating diseases. Currently available therapies for end stage heart failure include drug and device therapies, as well as heart transplantation. While drug and device therapies have proven effective at reducing symptoms, hospitalizations and deaths due to heart failure, new approaches are clearly required to improve this low survival rate. Organ transplantation is highly effective at increasing patient survival, but is severely limited in its potential for broad-based application by the very low number of hearts that are available for transplantation each year. Stem cell therapy may be a promising strategy for improving heart failure patient outcomes by transplanting cells rather than a whole heart. Several studies have convincingly shown that human embryonic stem cells can be differentiated into heart muscle cells (cardiomyocytes) and that these cells can be used to improve cardiac function following a heart attack. The key objective of this CIRM Disease Team Therapy proposal is to perform the series of activities necessary to obtain FDA approval to initiate clinical testing of human embryonic stem cell-derived cardiomyocytes in end stage heart failure patients.
Statement of Benefit to California: 
Coronary artery disease (CAD) is the number one cause of mortality and morbidity in the US. The American Heart Association has estimated that 5.7 million Americans currently suffer from heart failure, and that another 670,000 patients develop this disease annually. Cardiovascular disease has been estimated to result in an estimated $286 billion in direct and indirect costs in the US annually (NHLBI, 2010). As the most populous state in the nation, California bears a substantial fraction of the social and economic costs of this devastating disease. In recent years, stem cell therapy has emerged as a promising candidate for treating ischemic heart disease. Research by our group and others has demonstrated that human embryonic stem cells (hESCs) can be differentiated to cardiomyocytes using robust, scalable, and cGMP-compliant manufacturing processes, and that hESC-derived cardiomyocytes (hESC-CMs) can improve cardiac function in relevant preclinical animal models. In this proposal, we seek to perform the series of manufacturing, product characterization, nonclinical testing, clinical protocol development, and regulatory activities necessary to enable filing of an IND for hESC-CMs within four years. These IND development activities will be in support of a Phase 1 clinical trial to test hESC-CMs in heart failure patients for the first time. If successful, this program will both pave the way for a promising new therapy to treat Californians with heart failure numbering in the hundreds of thousands, and will further enhance California’s continuing prominence as a leader in the promising field of stem cell research and therapeutics.
Progress Report: 
  • Patients with end-stage heart failure (ESHF), which can result from heart attacks, have a 2-year survival rate of 50% with conventional medical therapy. Unlike cells of other organs, the billions of cardiomyocytes lost due to damage or disease do not regenerate. Recently, implantable mechanical pumps that take over the function of the failing left ventricle (left ventricular assist devices; LVADs) have been used to prolong the lives of heart failure patients. However, these devices carry an increased risk of stroke. The only current bona fide cure for ESHF is heart transplantation, but the shortage of donor organs and the risks associated with life-long use of powerful immunosuppressive drugs limit the number of patients that can be helped.
  • Human embryonic stem cells (hESCs) have the unique properties of being able to grow without limit and to be converted into all the cell types of the body, including cardiomyocytes. Our project seeks to find ways to treat patients by replacing their lost cardiomyocytes with healthy ones derived from hESC. The ultimate goal of this 4 year project is to evaluate the feasibility, safety, and efficacy of this approach in both small and large animal models of heart disease and to use this data to initiate a clinical trial to test the therapy in patients.
  • In our first year, we developed methods for producing essentially unlimited quantities of cardiomyocytes from hESCs using a process that is compatible both with clinical needs and large-scale industrial cell production. We have also developed models of heart disease in both rats and pigs, and have begun transplanting the stem cell-derived cardiomyocytes into the rat model. We have demonstrated that stem cell-derived cardiomyocytes can engraft in this animal model and we are testing their effects on the pumping function of the heart, the growth of replacement blood vessels lost during a heart attack, and the size of the scar that typically forms after injury. In the next several years, we will continue to evaluate the safety and function of these cells and will start to transplant in our large animal model of heart disease, which will enable us to test these cells in a heart with very similar characteristics to humans, delivered in a minimally invasive way that would be ideal for clinical use.

Molecular Mechanisms Underlying Human Cardiac Cell Junction Maturation and Disease Using Human iPSC

Funding Type: 
Basic Biology III
Grant Number: 
RB3-05103
ICOC Funds Committed: 
$1 341 955
Disease Focus: 
Heart Disease
Pediatrics
Stem Cell Use: 
iPS Cell
Cell Line Generation: 
iPS Cell
Public Abstract: 
Heart disease is the number one cause of death and disability in California and in the United States. Especially devastating is Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC), an inherited form of heart disease associated with a high frequency of arrhythmias and sudden cardiac death in young people, including young athletes, who despite their appearance of health are struck down by this type of heart disease. Even though it is inherited, early detection is hindered because people carrying the genetic code have highly variable clinical symptoms, making ARVC and catastrophic cardiac events very hard to predict and avoid. Evidence suggests that this heart disease is caused by mistakes in the genetic code essential for holding the mechanical integrity of heart muscle cells together or cell junctions. What is missing is an understanding of the basic biology of these heart muscle cell junctions in humans and appropriate human model systems to study their dynamics in heart disease, which is important since other heart diseases also share some of these same heart cell defects. Our goal is to understand the basic biology of how human heart muscle cell junctions mature and what happens in disease, by studying ARVC. Human iPS cells are a unique population of stem cells from our own tissues, such as skin, that have the same genetic information as the rest of our bodies. Thus, hiPS from people who carry the ARVC heart disease mistakes can be used in our laboratory to provide a true human model of that disease. We will generate heart muscle cells from hiPS from normal and ARVC donors that carry mistakes in the genetic code for cell junction components. We have identified new pathways that may be important causes of ARVC, thus we will also use our hiPS lines, to confirm whether these new pathways are truly important in human ARVC disease progression and if our approaches reverse disease progression. Characterization of our hiPS derived heart cells can also be exploited for translational medicine to predict an individual's heart cell response to drug treatment and provides a promising platform to identify new drugs for heart diseases, such as ARVC, which are currently lacking in the field. Recent advances in stem cell biology have highlighted the unique potential of hiPS to be used in the future as a source of cells for cell-based therapies for heart disease. However, prior to clinical application, a detailed understanding of the basic biology and maturation of these hiPS into heart muscle cells is required. Our studies seek to advance our understanding of how cell-cell junctions mature in hiPS and highlight tools that influence the microenvironment of the hiPS in a dish, to accelerate this process. This knowledge can also be exploited in regenerative medicine to achieve proper electromechanical integration of cardiac stem cells when using stem cells for heart repair, to improve longterm successful clinical outcomes of cardiac stem cell therapies.
Statement of Benefit to California: 
Heart disease is the number one cause of death and disability within the United States and the rates are calculated to be even higher for citizens of the State of California when compared to the rest of the nation. These diseases place tremendous financial burdens on the people and communities of California, which highlights an urgency to understand the underlying molecular basis of heart diseases as well as find more effective therapies to alleviate these growing burdens. Our goal is to improve heart health and quality of life of Californians by generating human stem cell models from people with an especially devastating form of genetic heart disease that affects young people and results in sudden cardiac death, to improve our molecular and medical understanding of how cardiac cells go wrong in the early stages of heart disease in humans. We will also test current drugs used to treat heart disease and new candidate pathways, that we have uncovered, to determine if and how they reverse and intervene with these defects. We believe that our model systems have tremendous potential in being used to diagnose, test an individual's heart cell's response to drug treatment, as well as predict severity of symptoms in heart diseases at an early stage, to monitor drug treatment strategies for the heart. We believe our studies also have a direct impact on regenerative medicine as a therapy for Californians suffering from heart disease, since data from our studies can identify ways to improve cardiac stem cell integration into the diseased heart when used for repair, as a way to improve long-term successful clinical outcomes of cardiac stem cell therapies. We also believe that our development of multiple human heart disease stem cells lines with unique genetic characteristics could be of tremendous value to biotechnology companies and academic researchers interested in large scale drug screening strategies to identify more effective compounds to rescue defects and treat Californians with heart disease, as well as provide important economic revenue and resources to California, which is stimulated by the development of businesses interested in developing these therapies further.
Progress Report: 
  • Heart disease is the number one cause of death and disability in California and in the United States. Especially devastating is Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC), an inherited form of heart disease associated with a high frequency of arrhythmias and sudden cardiac death in young people, including young athletes, who despite their appearance of health are struck down by this type of heart disease. Even though it is inherited, early detection is hindered because people carrying the genetic code have highly variable clinical symptoms, making ARVC and catastrophic cardiac events very hard to predict and avoid. Evidence suggests that this heart disease is caused by mistakes in the genetic code essential for holding the mechanical integrity of heart muscle cells together or cell junctions. What is missing is an understanding of the basic biology of these heart muscle cell junctions in humans and appropriate human model systems to study their dynamics in heart disease, which is important since other heart diseases also share some of these same heart cell defects. Our goal is to understand the basic biology of how human heart muscle cell junctions mature and what happens in disease, by studying ARVC. Human iPS cells are a unique population of stem cells from our own tissues, such as skin, that have the same genetic information as the rest of our bodies. Thus, hiPS from people who carry the ARVC heart disease mistakes can be used in our laboratory to provide a true human model of that disease. During the first year of our grant, we have enrolled sufficient numbers of normal and ARVC donors into our study. We have collected skin biopsy tissues from donors as means to generate hiPS cells. Our results show that hiPS cell lines can be efficiently generated from both normal and ARVC donors and we have extensively characterized their profiles, such that we know they are bona fide stem cell lines and can be used as a model system to dissect defects in cardiac cell junction biology between these various different hiPS lines. We have also developed efficient and robust methodologies to generate heart muscle cells from hiPS from normal and ARVC donors that carry mistakes in the genetic code for cell junction components and are now in the midst of characterizing their molecular, genetic, biochemical and functional profiles to identify features in these cells that are unique for ARVC. Through our previous studies, we identified new pathways that may be important causes of ARVC, thus we will also use our hiPS lines, to confirm whether these new pathways are truly important in human ARVC disease progression and if our approaches reverse disease progression. Towards this goal, we have generated novel tools to increase and decrease a component of this pathway in order to test these approaches and have preliminary data to show that these tools are efficient in altering levels of this component in heart muscle cells, which we are now applying towards understanding these pathways in hiPS derived heart muscle cells and reversing defects in heart muscle cells from ARVC hiPS derived lines. Based on our progress, we have met all of the milestones stated in our grant proposal and in some cases, surpassed some milestones. We believe progress over the next year, will allow us to define some of the key cellular defects in ARVC and advance our understanding of how cell-cell junctions mature in hiPS and highlight tools that influence the microenvironment of the hiPS in a dish, to accelerate this process.
  • Overall, we have been able to achieve the milestones proposed for Year 2 of the grant. We have generated a panel of control and ARVC hiPSC lines using integration-free based methods. We provide evidence of our method to generate robust numbers of hiPSC-derived cardiac cells that express desmosomal cell-cell junction proteins. We show ARVC lines that display disease symptom-specific features (adipogenic or arrhythmic), which phenocopy the striking and differential symptoms found in respective individual ARVC-patients as tools to study human ARVC. We also uncover desmosomal defects in hiPSC-derived cardiac muscle cells that underlie the disease features found in ARVC cells. We have also published two reviews in the field of cell-cell junctional remodeling and stem cell approaches that helps to further our understanding of this field in cardiomyocytes, that is relevant to human disease and our research using hiPS.
  • Overall, we have been able to complete the milestones proposed for our grant. We have generated a unique panel of control and ARVC hiPSC lines using integration-free methods. We provide evidence of our method to generate robust numbers of hiPSC derived cardiac cells that express key components of the cardiac muscle cell-cell junction include mechanical junctions and electrical junctions. We show that our ARVC hiPSC lines display disease symptom-specific features (adipogenic and arrhythmic), which phenocopy the striking and differential diagnosis observed in our ARVC donor hearts and provide a platform to study the varying disease features underlying ARVC. We uncover novel and classic molecular and ultrastructural defects underlying the arrhythmogenic defects in our ARVC hiPSC lines that mimic the gradation in disease severity observed in ARVC donor hearts. We exploit conventional ARVC drugs to determine their impact on arrhythmogenic behavior and reversibility of phenotypes in our cells. We have published 4 articles in the field of cell-cell junction remodeling, protein turnover and stem cell approaches that further our understanding of this field in cardiac muscle cells as well as filed a provisional patent application on the use of a novel drug discovery system for fat arrhythmogenic disorders that exploit the genetic diversity and clinical features observed in our ARVC lines.

Mechanisms of Direct Cardiac Reprogramming

Funding Type: 
Basic Biology III
Grant Number: 
RB3-05174
ICOC Funds Committed: 
$1 708 560
Disease Focus: 
Heart Disease
oldStatus: 
Active
Public Abstract: 
Heart disease is a leading cause of adult and childhood mortality. The underlying pathology is typically loss of heart muscle cells that leads to heart failure, or improper development of specialized cardiac muscle cells called cardiomyocytes during embryonic development that leads to congenital heart malformations. Because cardiomyocytes have little or no regenerative capacity after birth, current therapeutic approaches are limited for the over 5 million Americans who suffer from heart failure. Embryonic stem cells possess clear potential for regenerating heart tissue, but efficiency of cardiac differentiation, risk of tumor formation, and issues of cellular rejection must be overcome. Our recent findings regarding direct reprogramming of a type of structural cell of the heart or skin called fibroblasts into cardiomyocyte-like cells using just three genes offer a potential alternative approach to achieving cardiac regeneration. The human heart is composed of muscle cells, blood vessel cells, and fibroblasts, with the fibroblasts comprising over 50% of all cardiac cells. The large population of cardiac fibroblasts that exists within the heart is a potential source of new heart muscle cells for regenerative therapy if it were possible to directly reprogram the resident fibroblasts into muscle cells. We simulated a heart attack in mice by blocking the coronary artery, and have been able to reprogram existing mouse cardiac fibroblasts after this simulated heart attack by delivering three genes into the heart. We found a significant reduction in scar size and an improvement in cardiac function that persists after injury. The reprogramming process starts quickly but is progressive over several weeks; however, how this actually occurs is unknown. Because this finding represents a new approach that could have clinical benefit, we propose to reveal the mechanism by which fibroblast cells become reprogrammed into heart muscle cells, which will be critical to refine the process for therapeutic use. We will do this by analyzing the changes in how the genome is interpreted and expressed at a genome-wide level at different time points during the process of fibroblast to muscle conversion, which represents the fundamental process that leads to reprogramming. The findings from this proposal will reveal approaches to refine and improve human cardiac reprogramming and will aid in translation of this technology for human cardiac regenerative purposes.
Statement of Benefit to California: 
This research will benefit the state of California and its citizens by helping develop a new approach to cardiac regeneration that would have a lower risk of tumor formation and cellular rejection. In addition, the approach could remove some of the hurdles of cell-based therapy including delivery challenges and incorporation challenges. The mechanisms revealed by this research will enable refinement of the method that could potentially then be used to treat the hundreds of thousands of Californians with heart failure.
Progress Report: 
  • Heart disease is a leading cause of adult and childhood mortality. The underlying pathology is typically loss of heart muscle cells that leads to heart failure, or improper development of specialized cardiac muscle cells called cardiomyocytes during embryonic development that leads to congenital heart malformations. Because cardiomyocytes have little or no regenerative capacity after birth, current therapeutic approaches are limited for the over 5 million Americans who suffer from heart failure. Embryonic stem cells possess clear potential for regenerating heart tissue, but efficiency of cardiac differentiation, risk of tumor formation, and issues of cellular rejection must be overcome.
  • Our recent findings regarding direct reprogramming of a type of structural cell of the heart or skin called fibroblasts into cardiac muscle-like cells using just three genes offer a potential route to achieve cardiac regeneration after cardiac injury. The large population of cardiac fibroblasts that exists within the heart is a potential source of new heart muscle cells for regenerative therapy if it were possible to directly reprogram the resident fibroblasts into muscle cells. In the last year, we simulated a heart attack in mice by blocking the coronary artery, and have been able to reprogram existing mouse cardiac fibroblasts after this simulated heart attack by delivering three genes into the heart. We found a significant reduction in scar size and an improvement in cardiac function that persists after injury. The reprogramming process starts quickly but is progressive over several weeks; however, how this actually occurs is unknown. Because this finding represents a new approach that could have clinical benefit, we are investigating the mechanism by which fibroblast cells become reprogrammed into heart muscle cells, which will be critical to refine the process for therapeutic use. During the last year, we have analyzed the changes in how the genome is interpreted and expressed at a genome-wide level at different time points during the process of fibroblast to muscle conversion, which represents the fundamental process that leads to reprogramming. We have also generated many reagents that will allow us to identify how the reprogramming factors interact with DNA to alter the interpretation. These reagents will be used in the coming year to more thoroughly investigate the epigenetic changes that induce changes in interpretation of the DNA, leading to the cardiac muscle phenotype. The findings from this proposal will reveal approaches to refine and improve human cardiac reprogramming and will aid in translation of this technology for human cardiac regenerative purposes.
  • Heart disease is a leading cause of adult and childhood mortality. The underlying pathology is typically loss of heart muscle cells that leads to heart failure, or improper development of specialized cardiac muscle cells called cardiomyocytes during embryonic development that leads to congenital heart malformations. Because cardiomyocytes have little or no regenerative capacity after birth, current therapeutic approaches are limited for the over 5 million Americans who suffer from heart failure. Embryonic stem cells possess clear potential for regenerating heart tissue, but efficiency of cardiac differentiation, risk of tumor formation, and issues of cellular rejection must be overcome.
  • Our recent findings regarding direct reprogramming of a type of structural cell of the heart or skin called fibroblasts into cardiac muscle-like cells using just three genes offer a potential route to achieve cardiac regeneration after cardiac injury. The large population of cardiac fibroblasts that exists within the heart is a potential source of new heart muscle cells for regenerative therapy if it were possible to directly reprogram the resident fibroblasts into muscle cells. We have simulated a heart attack in mice by blocking the coronary artery, and have been able to reprogram existing mouse cardiac fibroblasts after this simulated heart attack by delivering three genes into the heart. We found a significant reduction in scar size and an improvement in cardiac function that persists after injury. The reprogramming process starts quickly but is progressive over several weeks; however, how this actually occurs is unknown. Because this finding represents a new approach that could have clinical benefit, we are investigating the mechanism by which fibroblast cells become reprogrammed into heart muscle cells, which will be critical to refine the process for therapeutic use. During the last year, we have analyzed the changes in how the genome is interpreted and expressed at a genome-wide level at different time points during the process of fibroblast to muscle conversion, which represents the fundamental process that leads to reprogramming. We have mapped the dynamic and sequential changes that are occurring on the DNA during reprogramming of cells. In the coming year, we will be integrating data from studies of epigenetic changes, DNA-binding of reprogramming factors, and the resulting alterations in activation or repression of genes that are responsible for changing a fibroblast into a cardiac muscle cell. The findings from this proposal will reveal approaches to refine and improve human cardiac reprogramming and will aid in translation of this technology for human cardiac regenerative purposes.
  • Heart disease is a leading cause of adult and childhood mortality. The underlying pathology is typically loss of heart muscle cells that leads to heart failure, or improper development of specialized cardiac muscle cells called cardiomyocytes during embryonic development that leads to congenital heart malformations. Because cardiomyocytes have little or no regenerative capacity after birth, current therapeutic approaches are limited for the over 5 million Americans who suffer from heart failure. Embryonic stem cells possess clear potential for regenerating heart tissue, but efficiency of cardiac differentiation, risk of tumor formation, and issues of cellular rejection must be overcome.
  • Our recent findings regarding direct reprogramming of a type of structural cell of the heart or skin called fibroblasts into cardiac muscle-like cells using just three genes offer a potential route to achieve cardiac regeneration after cardiac injury. The large population of cardiac fibroblasts that exists within the heart is a potential source of new heart muscle cells for regenerative therapy if it were possible to directly reprogram the resident fibroblasts into muscle cells. We have simulated a heart attack in mice by blocking the coronary artery, and have been able to reprogram existing mouse cardiac fibroblasts after this simulated heart attack by delivering three genes into the heart. We found a significant reduction in scar size and an improvement in cardiac function that persists after injury. The reprogramming process starts quickly but is progressive over several weeks; however, how this actually occurs is unknown. Because this finding represents a new approach that could have clinical benefit, we are investigating the mechanism by which fibroblast cells become reprogrammed into heart muscle cells, which will be critical to refine the process for therapeutic use. During this project, we have analyzed the changes in how the genome is interpreted and expressed at a genome-wide level at different time points during the process of fibroblast to muscle conversion, which represents the fundamental process that leads to reprogramming. We have mapped the dynamic and sequential changes that are occurring on the DNA during reprogramming of cells. In the last year, we have determined the epigenetic changes occurring and correlated those with DNA-binding of reprogramming factors, and the resulting alterations in activation or repression of genes that are responsible for changing a fibroblast into a cardiac muscle cell. The findings from this proposal are revealing approaches to refine and improve human cardiac reprogramming and will aid in translation of this technology for human cardiac regenerative purposes.

Engineering microscale tissue constructs from human pluripotent stem cells

Funding Type: 
Research Leadership 14
Grant Number: 
LA1_C14-08015
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.

Tissue Collection for Accelerating iPSC Research in Cardiovascular Diseases

Funding Type: 
Tissue Collection for Disease Modeling
Grant Number: 
IT1-06596
Investigator: 
ICOC Funds Committed: 
$1 435 371
Disease Focus: 
Heart Disease
oldStatus: 
Active
Public Abstract: 
Heart failure is a very common and chronic condition defined by an inability of the heart to pump blood effectively. Over half of cases of heart failure are caused by a condition called dilated cardiomyopathy, which involves dilation of the heart cavity and weakening of the muscle. Importantly, many cases of this disease do not have a known cause and are called “idiopathic” (i.e., physicians do not know why). Over the past 2 decades, doctors and scientists started realizing the disease can cluster in families, leading them to think there is a genetic cause to the disease. This resulted in discovering multiple genes that cause this disease. Nonetheless, the majority of cases of dilated hearts that cluster in families do not have a known genetic cause. Now scientists can turn blood and skin cells into heart cells by genetically manipulating them and creating engineered stem cells called “induced pluripotent stem cells” or iPSCs. This approach enables the scientists to study what chemical or genetic changes are happening to cause the problem. Also because these cells behave similar to the cells in the heart, scientists can now test new medicines on these cells first before trying them in patients. Here we aim to collect tissue from 800 patients without a known cause for their dilated hearts (and 200 control individuals) to help accelerate our understanding of this debilitating disease and hopefully offer new and better treatments.
Statement of Benefit to California: 
Heart failure is a significant health burden in California with rising hospitalization and death rates in the state. We have a very limited understanding of the disease and so far the existing treatments only slow down the disease and the changes that happen rather than target the root cause. By studying a subgroup of the dilated cardiomyopathy patients who have no identified cause, we can work on identifying genetic causes of the disease, some of the biology happening inside the heart cell, and provide new treatments that can prevent the disease from happening or progressing. Improving the outcome of this debilitating disease and providing new treatments will go a long way to helping a large group of Californians lead healthier and longer lives. There are estimates that the US economy loses $10 billion (not counting medical costs), because heart failure patients are unable to work. Hence new knowledge and developments gained from this research can go a long way to ameliorating that cost. Finally, heart failure is the most common chronic disease patients in California are hospitalized for. This research targets over half of those admissions. If this research is able to cut the hospitalization rate even by 1%, this would translate to millions of dollars in savings to the state. Continuing to invest in innovation will make our state a hotbed for the biotechnology industry, which in turn advances the state’s economic and educational status.
Progress Report: 
  • Heart failure is a leading cause of morbidity and mortality in California and the Western world with a significant economic burden due to the disease. Over half of heart failure cases are due to dilated cardiomyopathy, a disorder of progressive ventricular dilation and decreased contractility. However, after ischemic cardiomyopathy, the majority of familial cases of dilated cardiomyopathy are unknown or "idiopathic", suggesting a polygenic etiology with a complex genetic-environmental interaction. Traditionally, studying this disorder has been impaired by inability to access cardiac tissue and the limitation of mouse models in recapitulating the disorder. Thus, we propose using human induced pluripotent stem cells (iPSCs) to study idiopathic familial dilated cardiomyopathy (IFDC). We propose collecting tissue from individuals identified with the disorder In summary, this proposal represents a unique
  • opportunity to improve our understanding of idiopathic familial dilated cardiomyopathy (which remains largely a mystery), identifying novel genetic causes (rendering many of these patients no longer “idiopathic), and proposing new therapeutic targets.

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