Heart Disease

Coding Dimension ID: 
295
Coding Dimension path name: 
Heart Disease
Funding Type: 
Comprehensive Grant
Grant Number: 
RC1-00151
Investigator: 
Institution: 
Type: 
PI
ICOC Funds Committed: 
$2 618 704
Disease Focus: 
Heart Disease
Stem Cell Use: 
Embryonic Stem Cell
oldStatus: 
Closed
Public Abstract: 
Cardiovascular disease (CVD) affects more than 71 million Americans and 1.7 million Californians. Recently, engineered cardiovascular tissue grafts, or “patches”, including one made from mouse embryonic stem cells (ESC), have shown promising results as a future therapy for CVD. Our overall goal is to extend these recent results to human ESC as follows. Aim 1: Apply mechanical stretch and electrical pacemaker-like stimulation to hESC-derived heart cells in order to make them stronger and beat at the same time. Current methods to turn hESC into heart cells do not result in the organization required to generate enough strength to support a weak heart and to avoid irregular heart beats. We will use specially engineered devices to apply mechanical stretch and electrical pacemaker-like stimulation to hESC-derived heart cells in order to strengthen them and make them beat in unison. Aim 2: Engineer a cardiovascular patch from hESC-derived heart cells in order to make a potential new therapy for heart disease. Recently, heart cells from mouse ESC, supporting structures called scaffolds, and mechanical stretch have successfully been combined to engineer a cardiovascular patch. We will combine the hESC-derived heart cells from Aim 1, scaffolds, and the same stretch and pacemaker-like stimulation as in Aim 1 to engineer a cardiovascular patch. In addition, we will add a specialized substance called VEGF to our patch so that, potentially, a blood supply will form around it after it is implanted on a diseased heart. We believe a blood supply will be necessary to keep our patch healthy, and in turn, this will allow our patch to help a damaged heart pump better. Aim 3: Assess whether our patch can remain healthy and also strengthen the heart of a rat after it has undergone a heart attack. We will first implant our cardiovascular patch in the rat aorta, the main blood vessel that supplies blood to the body, to test whether the patch remains healthy and whether it can contract and beat on its own. We will first use the aortic position because we feel it will allow us to assess the inherent function of the patch, thus facilitating our efforts to improve its design. After testing in the aortic position, we will implant the patch over damaged heart tissue in a rat that has undergone an experimentally created heart attack. Over a period of several weeks, we will use novel imaging techniques, ultrasonography, echocardiography, and electrocardiography to non-invasively test whether the patch remains healthy and whether the patch helps the damaged heart pump better. We believe the above aims will address questions relevant to hESC-based cardiovascular therapies and will provide vital information needed for safe and effective future clinical translation. As we will evaluate both federally and non-federally approved cell lines, and thus unlikely to receive federal funding, we will need to rely on the support provided by CIRM to carry out our objectives.
Statement of Benefit to California: 
Cardiovascular disease (CVD) affects more than 1.7 million Californians and 71 million Americans. The societal and financial impacts are tremendous, with CVD accounting annually for an estimated $8 billion in CA and nearly $400 billion in US health care costs. In the case of chronic illness such as CVD, the state and national health care systems may not be able to meet the needs of patients or control spiraling costs, unless the focus of therapy switches away from maintenance and toward cures. Fortunately, the passage of Proposition 71 in 2004, and the subsequent creation of the California Institute for Regenerative Medicine (CIRM), has created the funding needed to advance human embryonic stem cell (hESC) research that could lead to curative therapies that would benefit both millions of Californians and Americans. Recently, engineered cardiovascular tissue grafts, made from rat neonatal cardiomyocytes (CM) and cardiomyocytes derived from mouse ESC, have shown promising results as a future therapy for CVD. The overall goal of our proposed research is to extend these recent studies to hESC and engineer a hESC-CM based cardiovascular tissue graft as a regenerative therapy for CVD. We believe the objectives of our research will benefit the people and the state of California by addressing questions relevant to hESC-based cardiovascular regenerative therapies and will provide vital information needed for safe and efficacious future clinical translation. Development of cures for diseases such as CVD could potentially improve the California health care system by reducing the long-term health care cost burden on California. In addition, the results of our research may provide an opportunity for California to benefit from royalties, patents, and licensing fees and benefit the California economy by creating projects, jobs, and therapies that will generate millions of dollars in new tax revenues in our state. Finally, stem cell research such as ours could further advance the biotech industry in California, serving as an engine for California’s economic future. We have assembled a multidisciplinary team of experienced investigators to attack the objectives of our proposed research. At the same time, we will train and mentor a new generation of bright students and junior scientists in the areas of hESC biology, regenerative medicine, and technology development. This ensures that an essential knowledge base will be preserved and passed on to both investigators and patients within and beyond California.
Progress Report: 
  • Specific Aim 1: To electromechanically condition hESC-derived cardiomyocytes.
  • Progress: Over the past year, we have designed and constructed a computer controlled integrated stretch system and electrical pacing system for applying mechanical and electrical stimulation. This system was used in conjunction with a stretchable microelectrode array (sMEA) and shown to successfully support, stretch, and pace primary murine cardiomyocytes (CM). We also have developed a strain array device for cell culture that effectively interfaces the desirable properties of high-throughput microscale fluidic devices with macroscale user-friendly features. One challenge we have encountered with our sMEAs is maintaining electrical continuity of electrodes as cells are stretched. As an alternative to traditional electrical stimulation we have created a system that optically induces electrical activity in hESC-CM. We are now able to optically and non-invasively pace cardiomyocytes differentiated from our modified hESC line.
  • Specific Aim 2: To engineer a hESC-CM based cardiovascular tissue graft.
  • Progress: From our first attempt at engineering a cardiovascular tissue graft as we reported in Year 1, we learned that our grafts would require large populatoins of relatively pure hESC-CMs. As a result, we concentrated our efforts over the past year in developing a more efficient differentiation method for producing larger yields and quantities of hESC-CM. Our method produces hESC-CM in a directed manner under feeder-free and serum-free conditions by controlling multiple cardiomyogenic developmental pathways. Also, in a collaborative effort, we are engineering a novel method for sorting cardiomyocytes. In order to promote improved viability of hESC-CM in our tissue grafts, co-transplantation with hESC-derived endothelial cells (hESC-EC), as opposed to VEGF alone, will likely be needed as shown recently by others. Over the past year, we have shown that we can produce hESC-EC and that their survival in the heart is enhanced by activation of acetylcholine receptors that lead to activation of pro-survival and anti-apoptosis pathways. Finally, in order to control spatial orientation of hESC-CM within our tissue grafts, we have demonstrated on-demand micropatterning of matrix proteins for cell localization and stem cell fate determination. We have illustrated the utility of a cantilever-based nano-contact printing technology for cellular patterning, mESC renewal, and mESC fate specification. We are currently extending our results to undifferentiated hESC and hESC-CM.
  • Specific Aim 3: To assess tissue graft viability and function in a small animal model.
  • Progress: Over the past year, we created hESC-CM based tissue grafts in linear form. In order to quantify the loss of cardiac function between healthy and diseased hearts, we have recently developed a novel in vitro hybrid experimental/computational system to measure active force generation in ventricular slices of rodent hearts. Quantification of the loss of cardiac function will guide us in determining the numbers of hESC-CM needed for producing grafts with varying force generating capacity. Finally, as outlined in our original proposal, we will first implant our tissue grafts in rat aortas as a novel test-bed to assess the graft’s inherent function while minimizing the confounding effects of underlying cardiac contractions. Over the past year we have successfully implanted decellularized aortic patches in rat aortas and are currently working on adding hESC-CM and hESC-EC to the patches to assess their viability and function.
  • In summary, in the second year of our project we have made strong progress on all three of our specific aims. Based on our current results, we anticipate we will continue to make significant progress in engineering a robust and functional cardiovascular tissue graft.
  • Specific Aim 1: To electromechanically condition hESC-derived cardiomyocyte(CM).
  • Progress: Over the past year, we tested, validated, and published an integrated strain and electrical pacing system that we designed and constructed. As mentioned in our previous reports, one challenge we encountered with our electromechanical devices is maintaining electrical continuity of electrodes as cells are stretched. As an alternative to traditional electrical stimulation, with collaborators at Stanford, we have created a system that optically induces electrical activity in hESC-CM by introducing light activated channelrhodopsin-2 (ChR2), a cationic channel, into undifferentiated hESC. In our initial manuscript we have also demonstrated the effects of light stimulation on a whole heart computational model in which we have virtually injected light-responsive hESC-CM in various areas of the simulated heart.
  • Specific Aim 2: To engineer a hESC-CM based cardiovascular tissue graft.
  • Progress: From our first attempt at engineering a cardiovascular tissue graft as we reported in Years 1, 2, and 3 we learned that our grafts would require large populations of relatively pure hESC-CMs. As a result, we’ve continued our efforts in developing a more efficient differentiation method for producing larger yields and quantities of hESC-CM. Our method produces hESC-CM and iPSC-CM in a directed manner under feeder-free, serum-free, and monolayer conditions by controlling TGF-beta/Activin, BMP, Wnt, and FGF pathways. We have used our differentiation protocols to contribute cardiomyocytes to our collaborators, which has resulted in one published manuscript and two submitted publications. Also, with our collaborator at UC Berkeley, we have engineered a novel method for identifying CMs based on their electrical signals and have reported our technology in one accepted manuscript and one under review.
  • Specific Aim 3: To assess tissue graft viability and function in a small animal model.
  • Progress: Over the past two years, we created hESC-CM based tissue grafts in linear and circular forms and our now creating grafts that can be optically controlled (see Aim 1 above). As described in our last progress report, in order to quantify the loss of cardiac function between healthy and diseased hearts, we have reported a novel in vitro hybrid experimental/computational system to measure active force generation in healthy ventricular slices of rodent hearts. Quantification of the loss of cardiac function will guide us in determining the numbers of hESC-CM needed for producing grafts with varying force generating capacity. We have also modeled eccentric and concentric cardiac growth through sarcomerogenesis in order to give us insight into how we might terminally mature our hESC-CM grafts. Finally, we have differentiated hESC into CM for one of our collaborators at Stanford and have performed detailed calcium imaging to show engraftment of hESC-CM with human heart tissue. This has given us great insight into how 3D tissue grafts might integrate with human heart tissue.
  • In summary, in the fourth year of our project we made good progress on all three of our specific aims. Based on our current results, we anticipate we will continue to make significant progress in engineering a robust and functional cardiovascular tissue graft as we originally proposed and we will continue our efforts. Undoubtedly, with the support of the CIRM grant over the past four years, we have made great strides towards creating a 3D tissue graft and believe we will demonstrate functional integration, not only with rodent hearts, but with human tissue, all within the coming year.
Funding Type: 
Comprehensive Grant
Grant Number: 
RC1-00132
Investigator: 
ICOC Funds Committed: 
$3 036 002
Disease Focus: 
Heart Disease
Stem Cell Use: 
Embryonic Stem Cell
oldStatus: 
Closed
Public Abstract: 
Adult heart muscle cells retain negligible proliferative capacity and this underlies the inability of the heart to replace muscle cells that are lost to injury, such as infarct, and underlies progression to heart failure. To date, no stem cell therapiy has produced significant cardiomyocyte replacement. Instead, transplanted cells, if they persist at all, produce endothelial cells or fibroblasts and the ameliorating effects on heart function that have been reported have been achieved by improving contractility, perfusion or other processes that are impaired in the failing heart. This proposal is to develop specific reagents and ultimately drugs to stimulate regeneration. Our approach integrates advances in stem cell biology, high-throughput (HT) biology, informatics and proteomics to identify small molecules, proteins and signal transduction pathways that control heart muscle formation from human embryonic stem cells (hESCs). High throughput assays will be developed and implemented to identify genes, signaling proteins, and small molecules that that control important steps in the differentiation, proliferation, and maturation of cardiac cells. Computer modeling and informatics will be used to identify and validate the signaling pathways that direct these critical processes. The discovery of small molecules and pathways will lead to protocols for 1) efficient directed differentiation of cardiomyogenic precursors from hESCs for research into transplantation and toxicology, 2) biotech reagents to stimulate cardiomyocyte renewal through directed differentiation of hESCs, and 3) cellular targets or lead compounds to develop drugs that stimulate regeneration from endogenous cells.
Statement of Benefit to California: 
This proposal is a multidisciplinary collaboration among stem cell biologists, chemists, and engineers to address a critical problem that limits the widespread use of hESC for cardiology applications. Developing the multidisciplinary technology and overcoming the hurdles to application of hESCs to biotech and clinic will benefit California in many ways, including: Research to discover novel tools to stimulate heart muscle regeneration from hESCs is clinically important. Cardiovascular disease is the single largest cause of death in the U.S. and the assays we will develop and the reagents themselves will be useful tools to direct cardiomyocyte regeneration. This will speed the translation of hESCs to the clinic, specifically by stimulating production of cardiomyocytes and potentially by enhancing their integration and function after engraftment. Heart regeneration from hESCs probably uses similar cellular proteins and signaling pathways as regeneration of cardiomyocytes from other sources, thus, this research might be broadly applicable to heart muscle repair. Regeneration from endogenous cells remains controversial but these tools should be useful reagents to study and hopefully stimulate endogenous repair. Bringing the diverse people together (chemists, cell biologists, and engineers) to address a stem cell problem forges new links in the academic community that should be capable of opening new areas of research. These new areas of research will be a important legacy of the stem cell initiative and promises to invigorate academic research. The technology that we are developing applies the new discipline of chemical biology to stem cell biology, and the merger promises to spin off new areas of investigation and biotech products with the potential to benefit the practice of medicine and the local economy. Lastly, supporting the leading edge technology and the collaboration will build the California infrastructure of high throughput chemical library screening so that it can be focused on other areas of biomedical research, both stem cell and non-stem cell.
Progress Report: 
  • The goal of this project is to identify small molecules that stimulate cardiomyocyte differentiation from stem cells. The strategy is to use embryonic stem ESC)-derived progenitors to screen for compounds and then optimize their chemical properties to generate molecules that can be used as reagents and potentially as lead compounds to develop drugs to stimulate regeneration in patient hearts. During year 2, progress is reported in: 1) optimizing the biological and pharmaceutical properties of 4 chemically diverse compounds discovered in year 1; 2) patent application filed on these compounds; 3) identification of targets and biological mechanism of action of 2 of the 4 compounds; 4) 1 compound has been validated in hESCs; 5) pilot screening completed of a new stem cell screen to discover molecules that act on late stage progenitors similar to cells thought to exist in the adult heart; 5) new assays developed and screened for discovering modulators of the Wnt pathway that enhance cardiomyocyte production. Thus, there are a total of 8 chemically distinct compounds under study and additional assays have been developed that should bring additional compounds into the pipeline during year 3.
  • This progress report covers FY3 of the project to identify and characterize novel small molecule probes of cardiomyocyte differentiation from stem cells. During FY3, we characterized 11 novel chemical entities that promote cardiomyocyte differentiation. The small, drug-like molecules affect distinct steps in cardiomyocyte differentiation – 5 compounds promote formation of uncommitted cardiac progenitors, 2 stimulated committed cardiac precursors, while 2 compounds act later to stimulate differentiation into cardiomyocytes. Thus, these compounds are novel probes of stem cell differentiation. Some of the compounds are characterized to act upon particular cellular target proteins while the targets of other compounds are unknown. Of the latter class, candidate targets have been characterized by biochemical studies; one of which has been confirmed by RNA interference, yielding a new pathway in cardiac cell formation from stem cells. Three of the chemical series have been described in a patent application. Additional primary hits are being characterized.
  • For FY4, we will continue characterization of a novel compounds. Particular focus will be on 4 chemical entities that promote later stages of human stem cell cardiomyocyte differentiation and on characterizing and discovering additional candidates that act on late-stage differentiation. In addition, we will develop a new pathway screen for a cellular target involved in specifying cardiomyocyte progenitors that have recently been shown to form new myocytes in vivo. Our new compounds are valuable probes of the underlying mechanism(s) responsible for making cardiac cells from stem cells. Moreover, recent data has shown that endogenous stem cells that reside in the adult heart resemble progenitors in the hESC cultures, so certain of our compounds can be considered as targeting cellular proteins and signaling pathways that might be beneficial to stimulate endogenous regeneration. Towards this goal, we will optimize the drug-like properties of the compounds in anticipation of in vivo testing for regenerative potential.
  • This research led to the discovery of small molecules that promote the formation of heart muscle cells from human pluripotent stem cells. The project used high throughput screening technology and medicinal chemistry, similar to that used in pharmaceutical companies, to discover and optimize the molecules. The cellular processes targeted by the compounds were also investigated, and in several cases this research uncovered novel roles for key cellular proteins and signaling pathways, such as Wnt and TGFb signaling, in stem cell differentiation. The compounds will be useful as reagents for cardiomyocyte preparation from stem cells, and patent applications have been filed.
Funding Type: 
Comprehensive Grant
Grant Number: 
RC1-00124
Investigator: 
ICOC Funds Committed: 
$2 524 617
Disease Focus: 
Heart Disease
Stem Cell Use: 
Embryonic Stem Cell
oldStatus: 
Closed
Public Abstract: 
Cardiovascular disease (CVD) is the leading cause of death in the United States. Over one million Americans will suffer from a new or recurrent heart attacks this year and over 40 percent of those will die suddenly. In addition, about two-thirds of the patients develop congestive heart failure; and in people diagnosed with CHF, sudden cardiac death occurs at 6-9 times the general population rate. Heart transplantation remains the only viable solution for severely injured hearts; however, this treatment is limited by the availability of donor hearts. Therefore, alternative strategies to treat end stage heart failure and blocked blood vessels are needed. The objective of this proposal is to determine whether human embryonic stem (hES) cell can be used for repairing the heart. Our collaborator Advanced Cell Technology (ACT) has recently succeeded in identifying conditions for the reproducible isolation of hES cells which have the characteristics of cells which form blood vessels and heart muscle. This proposal will assess whether the hES cells can form new functional blood vessels and repair injured heart muscle in a rat model of heart attacks. Results from these studies will help develop new therapies for treating patients with heart attacks.
Statement of Benefit to California: 
Cardiovascular disease (CVD) is the leading cause of death in California and the United States. Over one million Americans will suffer from a new or recurrent myocardial infarction this year and over 40 percent of those will die suddenly. In addition, about two-thirds of myocardial infarction patients develop congestive heart failure. The 5-year mortality rate for CHF is about 50%, and in people diagnosed with CHF, sudden cardiac death occurs at 6-9 times the general population rate. Heart transplantation remains the only viable solution for severely injured hearts; however, this treatment is limited by the availability of donor hearts. It is estimated that health care costs for CVD is over 18 billion dollars a year. Additionally, the morbidity associated with CVD cost California and the nation billions of dollars a year. Therefore, alternative strategies to treat end stage heart failure and ischemia are needed. (Source: American Heart Association. Heart Disease and Stroke Facts, 2004, Dallas, TX: AHA 2004; American Heart Association. Heart Disease and Stroke Statistics-2006 Update, Dallas, TX: AHA 2006). The field of regenerative medicine is important to California and the nation. Advances in the technology to find cell based therapies will be revolutionary in their impact on patient care. Human embryonic stem (hES) cells have the potential to become all of the cells in the human body, and their unique properties give researchers the hope that from these primitive cells new therapies can result that may be available in time for the looming health care crisis. This project is focused on a pre-clinical application of a specific hES cell based therapy for myocardial regeneration and an antibody targeting technology to direct stem cells to injured organs. This project will benefit California in several ways including: 1) support for UC trainees, 2) potential of developing important clinical trials in CA based on results from this proposal, and 3) enhancement of the biotechnology industry in CA which would lead to the creation of new jobs in CA and an enhanced tax base.
Progress Report: 
  • Myocardial infarction can lead to death and disability with a 5-year death rate for congestive heart failure of 50%. It is estimated that cardiovascular disease is the leading cause of mortality and morbidity and is predicted to be the leading cause of death worldwide by 2020. Currently, heart transplantation is the only successful treatment for end-stage heart failure; however, the ability to provide this treatment is limited by the availability of donor hearts. Therefore, alternative therapies for both acute and chronic myocardial ischemia need to be developed.
  • Our results demonstrate that human embryonic stem cell (hESC)-derived hemangioblasts can create new blood vessels and improve blood flow in a rodent model of myocardial infarction. We demonstrated that adult stem cells (bone marrow CD34+ cells) can be successfully targeted to injured heart tissue, thus avoiding surgery or invasive catheter based therapies. The antibody technology can be used to target hESC-derived hemangioblasts specifically to injured heart tissue.
  • Further studies are needed to confirm our initial findings, determine whether the new blood vessel formation lead to an increase in heart function and safety studies. Studies are in progress to improve the efficiency and effectiveness of hESC-derived hemangioblasts to create new blood vessels. Additionally, investigations are underway to determine if immunosuppressive drugs will be necessary to increase survival of the hESC-derived hemangioblast. Our initial finding of hES-derived hemangioblasts inducing new blood vessel formation may eventually lead to the development of an unlimited and reliable cell source for renewing blood vessels and treating myocardial infarction.
  • Coronary artery disease (CAD) remains the leading cause of morbidity and mortality worldwide and is predicted to be the leading cause of death by 2020. In the US, it is estimated that cardiovascular disease affects 60 million patients costing the healthcare system approximately $186 billion annually. Approximately two-thirds of patients sustaining a myocardial infarction do not make a complete recovery and often are left with debilitating congestive heart failure. Despite the advances in medical treatment and interventional procedures to reduce mortality in patients with CAD, the number of patients with refractory myocardial ischemia and congestive heart failure is rapidly increasing. For end-stage heart failure, heart transplantation is the only successful treatment. However, the ability to provide this treatment is limited by the availability of donor hearts. Therefore, alternative therapies in the prevention and treatment of end-stage heart failure are needed.
  • Critical to any heart repair strategy is the need to provide vessels to allow for an adequate blood supply to nourish the heart. Our results demonstrate that human embryonic stem cell (hESC)-derived hemangioblasts can create new blood vessels and improve blood flow in a rodent model of myocardial infarction. Studies are in progress to improve the efficiency and effectiveness of hESC-derived hemangioblasts to create new blood vessels. Strategies to improve efficiency and effectiveness include the use of extracellular matrix proteins (components that make up the structural aspect of the heart) to increase the survival of the cells or the use of antibodies to direct and link the cells to the damaged heart muscle. Additionally, to decrease the risk of tumor formation from the hESC-derived hemangioblasts, the hESC-derived hemangioblasts are being cultured to form more mature endothelial cells (cells that mimic the bodies natural cells that produce blood vessels). These cells are being tested to determine whether they can effectively induce blood vessels in the heart. Our initial finding of hES-derived hemangioblasts inducing new blood vessel formation may eventually lead to the development of an unlimited and reliable cell source for renewing blood vessels and treating myocardial infarction.
  • Coronary artery disease (CAD) remains the leading cause of morbidity and mortality worldwide and is predicted to be the leading cause of death by 2020. In the US, it is estimated that cardiovascular disease affects 60 million patients costing the healthcare system approximately $186 billion annually. Approximately two-thirds of patients sustaining a myocardial infarction do not make a complete recovery and often are left with debilitating congestive heart failure. Despite the advances in medical treatment and interventional procedures to reduce mortality in patients with CAD, the number of patients with refractory myocardial ischemia and congestive heart failure is rapidly increasing. For end-stage heart failure, heart transplantation is the only successful treatment. However, the ability to provide this treatment is limited by the availability of donor hearts. Therefore, alternative therapies in the prevention and treatment of end-stage heart failure are needed.
  • Critical to any heart repair strategy is the need to provide vessels to allow for an adequate blood supply to nourish the heart. Our results demonstrate that human embryonic stem cell (hESC)-derived hemangioblasts can create new blood vessels and improve blood flow in a rodent model of myocardial infarction. Subsequent studies with hESC-derived endothelial progenitor cells decreased MI size and improved LV function in a mouse model of myocardial ischemia. Studies are in progress to improve the efficiency and effectiveness of hESC-derived endothelial progenitor cells to create new blood vessels.
  • Strategies to improve efficiency and effectiveness of stem cell therapy include the use of extracellular matrix proteins (components that make up the structural aspect of the heart) to increase the survival of the cells or the use of antibodies to direct and link the cells to the damaged heart muscle. We have demonstrated that antibodies can direct stem cells to injured myocardial tissue. Continued studies are in progress to perform studies needed for the submission of an IND. The development of peptide-modified scaffolds for the treatment of chronic heart failure has produced initial proof of concept studies that a tissue engineering approach for restoration of an injured heart is possible. Additionally, we have demonstrated that extracellular matrix derived peptides can recruit endogenous cardiac stem cells. Further development of a biopolymer scaffold for the treatment of chronic heart failure is in progress.
  • Coronary artery disease (CAD) remains the leading cause of morbidity and mortality worldwide and is predicted to be the leading cause of death by 2020. In the US, it is estimated that cardiovascular disease affects 60 million patients costing the healthcare system approximately $186 billion annually. Approximately two-thirds of patients sustaining a myocardial infarction do not make a complete recovery and often are left with debilitating congestive heart failure. Despite the advances in medical treatment and interventional procedures to reduce mortality in patients with CAD, the number of patients with refractory myocardial ischemia and congestive heart failure is rapidly increasing. For end-stage heart failure, heart transplantation is the only successful treatment. However, the ability to provide this treatment is limited by the availability of donor hearts. Therefore, alternative therapies in the prevention and treatment of end-stage heart failure are needed.
  • Critical to any heart repair strategy is the need to provide vessels to allow for an adequate blood supply to nourish the heart. Our results demonstrate that human embryonic stem cell (hESC)-derived hemangioblasts can create new blood vessels and improve blood flow in a rodent model of myocardial infarction. Subsequent studies with hESC-derived endothelial progenitor cells decreased MI size and improved LV function in a mouse model of myocardial ischemia. Studies are in progress to improve the efficiency and effectiveness of hESC-derived endothelial progenitor cells to create new blood vessels.
  • Strategies to improve efficiency and effectiveness of stem cell therapy include the use of extracellular matrix proteins (components that make up the structural aspect of the heart) to increase the survival of the cells or the use of antibodies to direct and link the cells to the damaged heart muscle. We have demonstrated that antibodies can direct stem cells to injured myocardial tissue. Continued studies are in progress to perform studies needed for the submission of an IND. The development of peptide-modified scaffolds for the treatment of chronic heart failure has produced initial proof of concept studies that a tissue engineering approach for restoration of an injured heart is possible. Additionally, we have demonstrated that extracellular matrix derived peptides can recruit endogenous cardiac stem cells. Further development of a biopolymer scaffold for the treatment of chronic heart failure is in progress.
Funding Type: 
Comprehensive Grant
Grant Number: 
RC1-00104
Investigator: 
ICOC Funds Committed: 
$2 229 140
Disease Focus: 
Heart Disease
Stem Cell Use: 
Embryonic Stem Cell
oldStatus: 
Closed
Public Abstract: 
Five million people in the U.S. suffer with heart failure, at a cost of $30 billion/year. Heart failure occurs when the heart is damaged and becomes unable to meet the demands placed on it. Unlike some tissues, heart muscle does not regenerate. Human embryonic stem cells grow and divide indefinitely while maintaining the potential to develop into many tissues of the body, including heart muscle. They provide an unprecedented opportunity to both study human heart muscle in culture in the laboratory, and advance cell-based therapy for damaged heart muscle. We have developed methods for identifying and isolating specific types of human embryonic stem cells, stimulating them to become human heart muscle cells, and delivering these into the hearts of mice that have had a heart attack. This research will identify those human embryonic stem cells that are best at repairing damaged heart muscle, thereby treating or avoiding heart failure.
Statement of Benefit to California: 
More than 90,000 people in California suffer with heart failure, at a cost of ~$540 million/year. Heart failure occurs when the heart is damaged and becomes unable to meet the demands placed on it. Unlike some tissues, heart muscle does not regenerate. This research will identify human embryonic stem cells that are able to repair damaged heart muscle, thereby treating or avoiding heart failure. The medical treatments developed as a result of these studies will not only benefit the health of Californians with heart failure, but also should result in significant savings in health care costs. This research will push the field of cardiovascular regenerative medicine forward despite the paucity of federal funds, and better prepare us to utilize these funds when they become available in the future.
Progress Report: 
  • Five million people in the U.S. suffer with heart failure, at a cost of $30 billion/year. Heart failure occurs when the heart is damaged and becomes unable to meet the demands placed on it. Unlike some tissues, heart muscle does not regenerate. Human embryonic stem cells grow and divide indefinitely while maintaining the potential to develop into many tissues of the body, including heart muscle. They provide an unprecedented opportunity to both study human heart muscle in culture in the laboratory, and advance cell-based therapy for damaged heart muscle. During the first year of CIRM support, we have developed methods for identifying and isolating specific types of human embryonic stem cells, and stimulating them to become human heart muscle cells. We are currently working to determine the best methods and timing for delivering these cells into the hearts of mice that have had a heart attack. This research will identify those human embryonic stem cells that are best at repairing damaged heart muscle, thereby treating or avoiding heart failure.
  • Five million people in the U.S. suffer with heart failure, at a cost of $30 billion/year. Heart failure occurs when the heart is damaged and becomes unable to meet the demands placed on it. Unlike some tissues, heart muscle does not regenerate. Human embryonic stem cells grow and divide indefinitely while maintaining the potential to develop into many tissues of the body, including heart muscle. They provide an unprecedented opportunity to both study human heart muscle in culture in the laboratory, and advance cell-based therapy for damaged heart muscle. During this year of CIRM support, we have developed methods for identifying and isolating specific types of human embryonic stem cells, and stimulating them to become human heart muscle cells. We are currently working to determine the best methods and timing for delivering these cells into the hearts of mice that have had a heart attack. This research will identify those human embryonic stem cells that are best at repairing damaged heart muscle, thereby treating or avoiding heart failure.
  • Five million people in the U.S. suffer with heart failure, at a cost of $30 billion/year. Heart failure occurs when the heart is damaged and becomes unable to meet the demands placed on it. Unlike some tissues, heart muscle does not regenerate. Human embryonic stem cells grow and divide indefinitely while maintaining the potential to develop into many tissues of the body, including heart muscle. They provide an unprecedented opportunity to both study human heart muscle in culture in the laboratory, and advance cell-based therapy for damaged heart muscle. During this year of CIRM support, we have developed methods for identifying and isolating specific types of human embryonic stem cells, and stimulating them to become human heart muscle cells. We are currently working to determine the best methods and timing for delivering these cells into the hearts of mice that have had a heart attack. This research will identify those human embryonic stem cells that are best at repairing damaged heart muscle, thereby treating or avoiding heart failure.
Funding Type: 
SEED Grant
Grant Number: 
RS1-00326
Investigator: 
Institution: 
Type: 
PI
ICOC Funds Committed: 
$658 125
Disease Focus: 
Heart Disease
Stem Cell Use: 
Embryonic Stem Cell
oldStatus: 
Closed
Public Abstract: 
Magnetic resonance imaging (MRI) has emerged as one of the predominant modalities to evaluate the effects of stem cells in restoring the injured myocardium. However, MRI does not enable assessment of a fundamental issue in cell therapy, survival of the transplanted cells. The transplanted human embryonic cells (hESC) must at the very least survive to restore the injured myocardium. This research proposal will address this specific challenge to image non-invasively both the survival of the transplanted hESC and the resultant restoration of the myocardium through sensitive detection of the molecular events indicating hESC survival and rapid imaging of myocardial function. In order to achieve this dual capability, there are 2 primary considerations: 1) amplification of molecular signals and 2) high spatial and temporal resolution imaging of the myocardium. No single imaging modality will fulfill all needs of non-invasive molecular imaging in the heart. Only an imaging modality that optimizes the 2 technical specifications will provide physiologically relevant meaning of the molecular signal of the transplanted hESC. The molecular signal will be useful if some correlation between hESC survival and functional restoration can be established. In order to address these critical issues, this proposal will describe efforts to implement molecular MRI to image both the survival of transplanted hESC and restoration of cardiac function using mouse model of myocardial infarction. This research proposes an integrated, multidisciplinary approach to converge innovative approaches in MRI and stem cell biology to address a fundamental yet very critical issue in cardiac restoration: survival of hESC following transplantation into the injured myocardium. This proposal combines novel molecular techniques with the high resolution capabilities of MRI. Upon conclusion of this research, an integrated MRI platform will be developed to allow dual evaluation of the survival of transplanted hESC and their effects on myocardial function. Maturation of this imaging technology will ultimately enable accurate assessment of the survival of hESC and restoration of recipient tissue in all human organs.
Statement of Benefit to California: 
Coronary artery disease (CAD) continues to be the leading cause of death in the United States. Recent advances in cardiovascular therapy have improved immediate survival following an acute myocardial infarction (MI). The persistence of high overall mortality of CAD despite improved treatment is due to a shift in the disease process. Studies have demonstrated a critical role of the infarcted myocardium in the development of congestive heart failure (CHF). The incidence of CHF is now reaching epidemic proportions. Today, there is higher number of deaths from patients developing CHF rather than those sustaining acute MI. CHF is the leading cause of hospital admissions resulting in approximately 300,000 deaths annually. There are nearly 5 million Americans who are suffering from this illness with 550,000 new cases reported each year. Over the last several decades, advances in biomedical technology provided significant improvement in morbidity and mortality. However, the average 5-year survival today still remains around a dismal 50%, creating a major public health concern. Heart transplantation is an established treatment for end-stage CHF. Yet, this definitive therapy is limited to only 2000 donor hearts per year. Thus, a strong mandate exists for an alternative therapeutic option. Human embryonic stem cells (hESC) have demonstrated the ability to differentiate into cardiac cells, representing a potential application of cell therapy to restore the injured myocardium. The public health impact of CHF in California is representative of the emerging trend seen across the United States. As the most populous State in the nation, CHF has resulted in equivalent burden to California’s health care cost, morbidity and mortality. The State of California stands to benefit tremendously with accurate MRI-guided monitoring of the therapeutic efficacy of hESC in an effort to advance the treatment for CHF.
Progress Report: 
  • Magnetic resonance imaging (MRI) has emerged as one of the predominant modalities to evaluate the effects of stem cells in restoring the injured heart. However, MRI does not enable assessment of a fundamental issue in cell therapy, survival of the transplanted cells. The transplanted human embryonic cells (hESCs) must at the very least survive to restore the injured heart. In order to address this issue, this research has conducted the fundamental work to develop a reporter gene as outlined in the proposal and developed a reliable system to evaluate the survival of the transplanted hESCs.
  • First, using a commercially available genetic construct, the reporter gene was designed to generate specific cell surface tags as a signal of cell survival. Molecular assays demonstrated proper characteristics of the reporter gene and the construct has been inserted into human embryonic kidney cells to demonstrate proof of concept. MRI signal was generated from these cells and this result has been validated by flow cytometry confirming the expression of cell surface tags by the reporter gene. Second, the metabolic effects of the contrast agent, iron-oxide, used to magnetically activate the antibodies have been evaluated. The results demonstrated that the iron-oxide has no toxic effects to the cell metabolism. Finally, preliminary MRI of the iron-oxide labeled hESC injected directly into the mouse heart was obtained.
  • Based on above results, the molecular signal was further refined to generate optical signal of cell survival as an additional validation tool. Robust molecular signal of hESC survival was generated following transplantation of the reporter gene transduced hESC into the mouse myocardium. During the no cost extenstion period, correlation between hESC survival and functional restoration of the injured heart will be assessed. Using MRI, cell survival and functional restoration of the heart will be imaged non-invasively in order to obtain longitudinal information regarding survival of transplanted hESC and restoration of heart function.
  • Magnetic resonance imaging (MRI) has emerged as one of the predominant modalities to evaluate the effects of stem cells in restoring the injured heart. However, MRI does not assess a fundamental issue in cell therapy, survival of the transplanted cells. The transplanted human embryonic cells (hESCs) must at the very least survive to restore the injured heart. In order to address this issue, this research has conducted the fundamental work to develop a reporter gene as outlined in the proposal and developed a reliable system to evaluate the survival and teratoma formation of the transplanted hESCs.
  • Using a commercially available genetic construct, the reporter gene was designed to generate specific cell surface tags as a signal of cell survival. Molecular assays demonstrated proper characteristics of the reporter gene and the construct has been inserted into human embryonic stem cells. MRI signal was generated from these cells and this result has been validated by flow cytometry confirming the expression of cell surface tags by the reporter gene in viable human embryonic stem cells. The viable cells expressing this reporter gene were transplanted into mouse heart and MRI signal was generated from the heart of a live mouse.
  • Based on the above results, the molecular signal was further refined to generate optical signal of cell survival as an additional validation tool. Robust molecular signal of hESC survival was generated following transplantation of the reporter gene transduced hESC into the mouse myocardium. During the no cost extenstion period, detection of hESC survival, proliferation, and early teratoma formation was studied. These biological properties of the transplanted hESCs were monitored accurately. This information will be used to correlate hESC survival/proliferation/teratoma formation with functional restoration of the injured heart.
Funding Type: 
SEED Grant
Grant Number: 
RS1-00242
Investigator: 
Institution: 
Type: 
PI
ICOC Funds Committed: 
$634 287
Disease Focus: 
Heart Disease
Stem Cell Use: 
Embryonic Stem Cell
oldStatus: 
Closed
Public Abstract: 
Stem cells therapies hold great promise in the treatment of cardiac diseases such as coronary heart disease or congestive heart failure. Thanks to their ability to transform into almost any kind of tissue, engrafted stem cells can potentially replace damaged heart tissues with healthy tissues, effectively restoring the heart’s original functions. While initial studies demonstrated the potential benefits of stem cell injection for repairing heart damage, they told researchers little about exactly how improvements were made to the heart and how the improvement might be enhanced. Also, there is concern that the stem cells could negatively impact some aspects of heart function and lead to disturbances of heart rhythm and future attacks. In light of this, we propose to develop a model to study the detailed interaction of stem cells and healthy heart tissue in the laboratory, where events within the cells and between the cells can be measured accurately and many experiments can be done to increase our understanding, without the use of human subjects. Specifically, we plan to focus on two main goals. The first goal is to develop a platform to better understand the gradual transition that stem cell lines make as they mature into heart cells, process known as differentiation. We will record the electrical activity arising from newly formed heart cells to determine when exactly they form and how the behave in response to electrical stimuli or drugs as they mature. This will tell us more about the behavior of the cells that could be injected into the heart so that we know how they will respond when they merge with the heart and when is the best time to introduce them. The second goal, building on the first one, is to observe how the stem cells make contact with the heart cells, including how they grow together mechanically and how they begin to communicate electrically as a repaired tissue. This will be carried out by growing the stem cells and heart cells separately and then allowing them to grow together, just as they would in the heart. Simultaneous recording of electrical activity at numerous locations in the culture will let us map the activity across the culture and evaluate the communication between heart cells (host) and stem cells (graft). Understanding the microscopic nature of integration of stem cells into healthy tissue will lead to a greater knowledge of what can happen when stem cells are injected into the heart and begin to replace the non-functional tissue and connect to healthy tissue. Insights gained with such model should lead to a better understanding of the repair process and highlight strategies for making stem cell-based therapies safer and more effective. This model will also allow testing and development of chemical or electrical manipulations that would increase the yield and reliability of the differentiation process, paving the way for the ultimate scale-up of stem cell therapies for clinical use.
Statement of Benefit to California: 
There is currently no cure for heart damage caused by heart attack, and stem cells offer a very promising solution to this problem that affects millions of Americans. We feel that addressing possible solutions to this pervasive problem is a very constructive and meaningful way to utilize some of the financial resources allocated for stem cell research in California. Within (and outside) the CIRM community, we also have the important goal of making currently unavailable electronic, microfabrication and signal processing technologies available in the form our proposed research platforms. With our planned outreach efforts, we will freely share our methods and equipment, hopefully enhancing the work of many other research groups. By using CIRM funds, we could make such systems available for use with non-registered (as well as registered) cell lines. The outcome of this research stands to impact not only citizens of California, but also the nation and the world. We aim to make considerable progress with research paid for by the citizens of California, demonstrating the degree to which we, as a people, are committed to solving problems in medicine and health care and improving the lives of others. This work will also benefit our State and taxpayers through the training of post-doctoral and graduate students with a clear mindset of leadership, creativity and compassion. Through publication and presentations at local, national and international forums, we hope to disseminate the knowledge gained and encourage further advances.
Progress Report: 
  • The success of cardiac cell grafts for repair of infarcts or congestive heart failure has been moderate to date. While graft cells may survive transplantation, their contribution to conduction and force generation is neither well-defined nor understood. Also, there is concern that the stem cells could negatively impact some aspects of heart function and lead to disturbances of heart rhythm. In light of this, we proposed to develop a model to study the detailed interaction of stem cells and healthy heart tissue in the laboratory, focusing on two main thrusts.
  • The first part of this project had seen the successful development of a platform to better understand the transition that stem cells make as they mature into heart cells, a process known as differentiation. Using arrays of microelectrodes, recording of electrical activity from maturing stem cells was demonstrated. Impact of electrical stimulation on the differentiation process had been probed. Investigation of the interaction between stem cells and heart cells had also been initiated. The second part focused mainly on the latter aspect – functional coupling of stem cells in the heart tissue. New analysis tools for the quantification of the conduction of the electrical activity across a heart tissue were developed. Studies with mixed co-cultures of cardiac cells and fibroblasts revealed a high sensitivity of the conduction properties to the presence of non-conductive cells (fibroblasts), and provide a model for assessing conduction in stem cell grafts of varying homogeneity. Co-cultures of heart cells (host) and stem cells (graft), first grown separately then allowed them to merge, highlighted issues of conduction mismatch at the interface between the host and graft tissue, as well as the dependence of this conduction on the maturity and purity of the grafts used. Most importantly, these studies demonstrated the value of the model developed under this grant for the investigation of electrical coupling and conduction in stem cell grafts, issues that are vital to the safe, effective and successful use of stem cell therapy.
Funding Type: 
SEED Grant
Grant Number: 
RS1-00239-A
Investigator: 
Type: 
PI
ICOC Funds Committed: 
$363 707
Disease Focus: 
Heart Disease
Stem Cell Use: 
Embryonic Stem Cell
Public Abstract: 
Congestive heart failure, the inability of the heart to continue to pump effectively due to damage of its muscle cells, affects approximately 4.8 million Americans and is a leading cause of mortality. Causes of the irreversible damage to the cardiomyocytes that results in congestive heart failure include hypertension, heart attacks, and coronary disease. Because the cadiomyocytes in the adult heart tissue are terminally differentiated and thus cannot regenerate themselves, once they are damaged, they are irreversibly damaged. As a consequence, despite the advances in medical devices and pharmaceuticals, still more than 50% of congestive heart failure patients die within 5 years of initial diagnosis. The goal therefore must be to restore the heart cells’ functions. This is possible by transplanting fetal and neonatal cardiomyocytes which can then integrate into the host tissue. This approach has demonstrated success in improving heart function. However, the limited availability of fetal donors has prevented its adoption as a viable therapeutic approach. Embryonic stem cells can overcome this challenge as they proliferate continuously in vitro and can be furthermore stimulated to differentiate. Embryoid bodies are three-dimensional clusters of heterogenous stem cells, some of which contain cardiac myocytes, which demonstrate characteristic spontaneous contractions. Controlled and efficient differentiation of the stem cells into cardiomyocytes and an effective way to characterize/verify these cells is critical. Ensuring a pure population of cardiac myocytes is essential because otherwise there is a high-likelihood of tumor formation when transplanted. Previous studies have shown that a low percentage of all embryoid bodies spontaneously form cardiomyocytes. Our goal is to therefore develop a self-contained system to grow and controllably differentiate the human embryonic stem cells into cardiomyocytes in high-yields. Few studies have characterized the types of cardiac myocytes in the differentiating human EBs. Our strategy is to use electrical and chemical cues to induce the high-yield differentiation of stem cells into cardiomyocytes and to monitor this process over time both electrically and optically.
Statement of Benefit to California: 
Improvements in differentiating stem cells into homogenous populations of specific cell types are much needed for transplantation therapy in general—and for congestive heart failure patients in particular. The benefits associated with the development of this micro platform have even broader reaching implications beyond biomedical research. After this system is developed, it will serve as a first platform of its kind that can be later commercialized, which would help spur industry growth. To vitalize and enable high-tech/biotech companies to this {REDACTED} area {REDACTED}, engaging industry involvement to this area is necessary. Supporting such activities would furthermore foster the opportunity for student internships with industry and well as afford the students opportunities in entrepreneurship. Our institution is a Hispanic-serving undergraduate institute with almost 50% minority students. Such a proposed system is vital for promoting both the diversity and research culture {REDACTED} and will be leveraged extensively in outreach programs to encourage underrepresented minorities in science education and training. By actively reaching out to specific students who would particularly benefit from our proposed undergraduate internship program, we can attract at-risk students to engage them in research to promote their retention.
Funding Type: 
SEED Grant
Grant Number: 
RS1-00239-B
Investigator: 
Type: 
PI
ICOC Funds Committed: 
$363 707
Disease Focus: 
Heart Disease
Stem Cell Use: 
Embryonic Stem Cell
oldStatus: 
Closed
Public Abstract: 
Congestive heart failure, the inability of the heart to continue to pump effectively due to damage of its muscle cells, affects approximately 4.8 million Americans and is a leading cause of mortality. Causes of the irreversible damage to the cardiomyocytes that results in congestive heart failure include hypertension, heart attacks, and coronary disease. Because the cadiomyocytes in the adult heart tissue are terminally differentiated and thus cannot regenerate themselves, once they are damaged, they are irreversibly damaged. As a consequence, despite the advances in medical devices and pharmaceuticals, still more than 50% of congestive heart failure patients die within 5 years of initial diagnosis. The goal therefore must be to restore the heart cells’ functions. This is possible by transplanting fetal and neonatal cardiomyocytes which can then integrate into the host tissue. This approach has demonstrated success in improving heart function. However, the limited availability of fetal donors has prevented its adoption as a viable therapeutic approach. Embryonic stem cells can overcome this challenge as they proliferate continuously in vitro and can be furthermore stimulated to differentiate. Embryoid bodies are three-dimensional clusters of heterogenous stem cells, some of which contain cardiac myocytes, which demonstrate characteristic spontaneous contractions. Controlled and efficient differentiation of the stem cells into cardiomyocytes and an effective way to characterize/verify these cells is critical. Ensuring a pure population of cardiac myocytes is essential because otherwise there is a high-likelihood of tumor formation when transplanted. Previous studies have shown that a low percentage of all embryoid bodies spontaneously form cardiomyocytes. Our goal is to therefore develop a self-contained system to grow and controllably differentiate the human embryonic stem cells into cardiomyocytes in high-yields. Few studies have characterized the types of cardiac myocytes in the differentiating human EBs. Our strategy is to use electrical and chemical cues to induce the high-yield differentiation of stem cells into cardiomyocytes and to monitor this process over time both electrically and optically.
Statement of Benefit to California: 
Improvements in differentiating stem cells into homogenous populations of specific cell types are much needed for transplantation therapy in general—and for congestive heart failure patients in particular. The benefits associated with the development of this micro platform have even broader reaching implications beyond biomedical research. After this system is developed, it will serve as a first platform of its kind that can be later commercialized, which would help spur industry growth. To vitalize and enable high-tech/biotech companies to this {REDACTED} area {REDACTED}, engaging industry involvement to this area is necessary. Supporting such activities would furthermore foster the opportunity for student internships with industry and well as afford the students opportunities in entrepreneurship. Our institution is a Hispanic-serving undergraduate institute with almost 50% minority students. Such a proposed system is vital for promoting both the diversity and research culture {REDACTED} and will be leveraged extensively in outreach programs to encourage underrepresented minorities in science education and training. By actively reaching out to specific students who would particularly benefit from our proposed undergraduate internship program, we can attract at-risk students to engage them in research to promote their retention.
Progress Report: 
  • This year, we have made quite some progress in developing the microtechnology platform. We have developed a new way to form and culture human embryonic stem cells into uniform embryoid bodies in a high throughput fashion. Instead of using the laborious ‘hanging drop method’ or the complicated ‘spinning flask method’, we have developed a way for researchers to easily pipette their cells into standard well plates and increase their throughput by almost 1000x. This is achieved by placing inserts with rounded-bottom microwells into standard well plates. Each one of these inserts that can fit into a standard 24 or 96 well plate can have up to 1000 wells and therefore can create 1000 embryoid bodies, all of uniform size. We can even create wells of various sizes such that we can induce embryoid bodies of predefined sizes and numbers of cells. Many recent publications have demonstrated that the initial size of the embryoid bodies affect differentiation. We have observed this as well. Moreover, this new platform allows researchers to perform real-time microscopy of the cells during this whole process.
  • In addition to developing this new chip, we have also electrically stimulated at different stages during differentiation. The different stages of differentiation include: 1) during embryoid body development 2) when transferred to gelatin coated dishes 3) after about a week on gelatin and 4) isolated beating areas. Electrical stimulation was accomplished using a C-PACE voltage pulsing device at a 1 Hz frequency, 4.5 V (2.5 V/cm), and a 1 ms duration. Unfortunately, none of the electrical stimulation yielded any exhibited increased expression of cardiac markers. Future studies will examine pacing of differentiated cardiac cells for synchronization and will employ more markers using a PCR super microarray.
  • We have also worked on custom software development that allows us to automatically identify and track individual cells within the microplatform.
  • There were a number of factors that caused some unexpected delays in scientific progress this year. Most notably, the PI Michelle Khine and her lab moved to a new university. Therefore, this took quite some time to take down and then re-establish the lab at its new location. Now at UC Irvine, she finally has the ideal infrastructure to make progress quickly on this project. This one year extension to finish this project is therefore much needed and greatly appreciated.
  • To uniformly control the differentiation of embryoid bodies (EBs), we have developed a very simple to use culture platform the create homogenous-sized EBs.
  • We have made quite some progress with the EB array culture plate development, described in detail in the last progress report. Since then, we have developed a way to 1) translate to a more transparent material with lower autofluorescence (cyclic olefin copolymer, COC) to be compatible with optical imaging (Figure 1, c) and then 2) mated the microwells to the bottom of 24 well plates for ease of handling. While we have not had success with applying electric fields to induce cardiomyocyte differentiation, we are now working with !) optimizing the EB size to yield the most cardiomyocytes and then 2)perfusing the EBs with soluble factors.
Funding Type: 
SEED Grant
Grant Number: 
RS1-00198
Investigator: 
Type: 
PI
ICOC Funds Committed: 
$609 999
Disease Focus: 
Heart Disease
Stem Cell Use: 
Embryonic Stem Cell
oldStatus: 
Closed
Public Abstract: 
Heart failure is a leading cause of mortality in California and the United States. Currently, there are no “cures” for heart failure.Other life threatening forms of heart disease include dysfunction of cardiac pacemaker cells, necessitating implantation of mechanical pacemakers. Although mechanical pacemakers can be efficacious, there are potential associated problems, including infection, limited battery half-life, and lack of responsiveness to normal biological cues. Our research with human embryonic stem cells will be aimed at developing therapies for heart failure, and cardiac pacemaker dysfunction. In each of these disease settings, one might effect a “cure” by replacing worn out or dysfunctional cardiac cells with new ones. In the case of heart failure, the cells that need to be replaced are heart muscle cells, which do the majority of the work in the heart. In the case of pacemaker dysfunction, the cells that need to be replaced are pacemaker cells, a highly specialized type of heart muscle cell. To replace these cells, we need to find cells that can become heart muscle or cardiac pacemaker cells, understand how to generate fairly large numbers of them, and how to persuade them to become either heart muscle or cardiac pacemaker cells. Potential cardiac progenitor cells may come from a number of different sources, either from patients themselves, or from extrinsic sources. Regardless of the source,we need to define factors which will make the cells multiply and will make them become the cell type that we need for repair. The biology of human heart cells is likely to be distinctive from that of heart cells from other animals. For example, a human heart has to function for multiple decades, unlike hearts of other animals who live in general for shorter periods of time. The size, required function, and rhythm of the human heart are also distinct from that of other animals. For these reasons, for repair of human heart, it is important to study human cardiac progenitors and to define pathways required to grow them and to differentiate them utilizing human cells as a model experimental system. Our proposed research will utilize human embryonic stem cells as a source of cardiac progenitors. As human embryonic stem cells can turn into many different kinds of cells, we will create special lines of human embryonic stem cells that will become fluorescent when they adopt the cardiac progenitor, heart muscle, or pacemaker state. These lines will then be treated with a large number of small molecules to find small molecules which amplify cells the number of fluorescent cells in each of these states. The small molecules activate known biochemical pathways, so we can then use the small molecules themselves, or activate identified pathways to achieve the goal of obtaining sufficient numbers of specific cardiac cell types for cardiac therapy.
Statement of Benefit to California: 
More Californians die each year of cardiovascular disease than from the next four leading causes of death combined. Californians continue to die or be disabled as a direct result of cardiovascular disease. Although advances in medical treatment have improved post-infarct survival, heart failure is an increasingly abundant manifestation of cardiovascular disease. A secondary complication of heart failure, and other cardiac diseases, is cardiac pacemaker dysfunction, a potentially fatal condition which is currently ameliorated by mechanical pacemakers. However, mechanical pacemakers have many associated complications,particularly for pediatric patients. For both heart failure and pacemaker dysfunction, replacement of heart muscle cells or biological pacemaker cells offers the hope of improving upon current medical practice. Our research is aimed toward developing new therapies which will allow for the replacement of these critical cell types in diseased heart.
Progress Report: 
  • In the current reporting period, we have worked on the generation of human embryonic stem cell derived marker cell lines for different steps of cardiomyocyte differentiation. The cell lines are designed to express fluorescent proteins under the control of gene promoters that mark cardiac progenitor cells, cardiomyocytes, or cardiac conduction system cells.
  • We tested several HUES cell lines for this purpose and chose cell lines that can differentiate into cardiomyocytes efficiently but are easy to expand and appear stable over several passages in culture. We generated several BAC transgenic cell lines that specifically express green fluorescent protein in cardiomyocytes. Further cell lines are being generated. The cell lines will be used in high-throughput screens to identify molecules and mechanisms that direct the efficient in vitro differentiation into different cardiac cells.
Funding Type: 
SEED Grant
Grant Number: 
RS1-00171
Investigator: 
ICOC Funds Committed: 
$744 639
Disease Focus: 
Heart Disease
Stem Cell Use: 
Embryonic Stem Cell
oldStatus: 
Closed
Public Abstract: 
Optimal cardiac function depends on the properly coordinated cardiac conduction system (CCS). The CCS is a group of specialized cells responsible for generating cardiac rhythm and conducting these signals efficiently to working myocardium. This specialized CCS includes the sinoatrial node, atrioventricular node and His-Purkinje system. These specialized pacemaking /conducting cells have different properties from the surrounding myocytes responsible for the contractile force. Genetic defects or postnatal damage by diseases or aging processes of these cells would result in impaired pulse generation (sinus node dysfunction, SND) or propagation (heart block). Implantation of an electronic cardiac pacemaker is necessary for intolerant bradycardia to restore cardiac rhythm. However, the electronic implantable pacemaker has multiple associated risks (e.g. infections) and requires frequent generator changes due to limited battery life. Sinus node dysfunction is a generalized abnormality of cardiac impulse formation and accounts for >30 percent of permanent pacemaker placements in the US. A perfect therapy to SND will be to repair or replace the defective sinus node by cellular or genetic approaches. Many recent studies have demonstrated, in a proof-of-concept style, of generating a biological pacemaker by implanting various types of progenitor or stem cells into ventricular myocardium to form a pulse-generating focus. However, a perfect biological pacemaker will require good connections with the intrinsic neuronal network for proper physiological responses. Elucidation of the factors controlling the evolution of pacemaker cells and their interaction with the peripheral neuronal precursor cells (neural crest cells, NCCs) will be paramount for creating an adaptive biological pacemaker. The NCCs have been shown to be contiguous with the developing conduction system in embryonic hearts of humans. However, the influence and interaction of the NCCs with the developing cardiac pacemaker cells remains unclear. In addition, there is no simple marker for identifying the pacemaker cells and the electrophysiological (EP) recording is the only physiological method to trace the evolution of cardiac pacemaker cells from human embryonic stem cells (hESCs). We have successfully obtained the EP properties of early hESC-derived cardiomyocytes. We propose here an in vitro co-culture system to study fate of the pacemaker cells evolved from hESCs and to investigate the influence of NCCs on the early, cardiac committed myocytes derived from hESCs. Such a study will provide insight in the development of pacemaker cells and in the mechanisms of early neuro-cardiac interaction. Results from the proposed study may suggest strategies for developing efficient and neuro-coupled cardiac pacemakers from ESCs. These neuro-coupled biological pacemaker cells may one day used clinically to replace the need for implanting an electronic pacemaker for the treatment of intolerant bradycardia.
Statement of Benefit to California: 
Optimal cardiac function depends on the properly coordinated cardiac conduction system. Genetic defects or postnatal damage by diseases or aging processes of these pacemaker cells would result in impaired pulse generation (sinus node dysfunction) or propagation (heart block). The implantation of an electronic cardiac pacemaker is necessary for intolerant bradycardia to restore physiologic cardiac rhythm. However, the electronic implantable pacemaker has multiple associated risks (e.g. infections and thrombosis) and requires frequent generator changes due to limited battery life. Sinus node dysfunction (SND) is a generalized abnormality of cardiac impulse formation and accounts for 30-50 percent of permanent pacemaker placements in the US. A perfect therapy to SND will be to repair or replace the defective sinus node by cellular or genetic approaches. Most of the research work on developing biological pacemakers are performed in Columbia University at New York City, Johns Hopkins University at Baltimore, and Technion-Israel Institute of Technology at Haifa, Israel. All of their approaches produced short-lived and non-responsive biological pacemakers to physiological demands. None of human stem cell-related research in California is devoted to this highly promising field of developing biological pacemakers. The proposed research here will elucidate the factors controlling the evolution of pacemaker cells and their interaction with the peripheral neuronal precursor cells (neural crest cells). Such a study will provide insight in the development of pacemaker cells and in the mechanisms of early neuro-cardiac interaction. These factors then can be used to generate better neuro-coupled biological pacemaker cells in California. These neuro-coupled biological pacemaker cells may one day be used clinically to replace the need for implanting an electronic pacemaker for the treatment of intolerant bradycardia. Creating the neuro-coupled, adaptive biological pacemakers will make California the epicenter of the next generation of pacemaker therapy, and will benefit its citizens who have intolerant cardiac bradycardia.
Progress Report: 
  • Cardiovascular diseases remain the major cause of death in the US. Human Stem and progenitor cell-derived cardiomyocytes (SPC-CMs) hold great promise for myocardial repairs. Recent progress in cellular reprogramming of various somatic cell types into induced pluripotent stem cells opened the door for developing patient-specific, cell-based therapies. However, most SPC-CMs displayed heterogeneous and immature electrophysiological (EP) phenotypes with uncontrollable automaticity. Implanting these electrically immature and inhomogeneous CMs to the hearts would likely be arrhythmogenic and deleterious. Furthermore, as CMs mature, they undergo changes in automaticity and electrical properties. We used human embryonic stem cell-derived CMs (hESC-CMs) as the model system to study the development and maturation of CMs in the embryoid body (EB) environment. Elucidating molecular pathways governing EP maturation of early hESC-CMs in EBs would enable engineered microenvironment to create functional pacemaker cells or electrophysiologically compatible hESC-CMs for cell replacement therapies. We have established antibiotic (Abx)-resistant hESC lines conferred by lentiviral vectors under the control of a cardiac-specific promoter. With simple Abx treatment, we easily isolated >95% pure hESC-CMs at various stages of differentiation from EBs. In the first year of this grant support and using the Abx selection system, we found that hESC-CMs isolated at early stages of differentiation without further contacts with non-cardiomyocytes (non-CMs) depicted arrested electrical maturation. The intracellular Ca2+-mediated automaticity developed very early and contributed to dominant automaticity throughout hESC-CM differentiation regardless of the presence or absence of non-CMs. In contrast, sarcolemmal ion channels evolved later upon further differentiation within EBs and their maturation required the interaction with non-CMs. In the second year, we further developed an add-back co-culture system to enable adding non-CMs back to early isolated hESC-CMs, which rescued the arrest of EP maturation. We also developed techniques to isolate pure subsets of non-CMs, such as neural crest and endothelial cells, from hESC-derived EBs, which exerted influences on maturation of specific subsets of ion channel populations respectively. Therefore, our study showed for the first time that non-CMs exert significant influences on the EP maturation of hESC-CMs during differentiation. Knowledge of this study will allow us to improve functional maturation of primitive hESC-CMs or to create neuro-coupled pacemaker cells before cell transplantation.
  • Cardiovascular diseases remain the major cause of death in the US. Human Stem and progenitor cell-derived cardiomyocytes (SPC-CMs) hold great promise for myocardial repairs. Recent progress in cellular reprogramming of various somatic cell types into induced pluripotent stem cells opened the door for developing patient-specific, cell-based therapies. However, most SPC-CMs displayed heterogeneous and immature electrophysiological (EP) phenotypes with uncontrollable automaticity. Implanting these electrically immature and inhomogeneous CMs to the hearts would likely be arrhythmogenic and deleterious. Furthermore, as CMs mature, they undergo changes in automaticity and electrical properties. We used human embryonic stem cell-derived CMs (hESC-CMs) as the model system to study the development and EP maturation of CMs in the embryoid body (EB) environment. Elucidating molecular pathways governing EP maturation of early hESC-CMs in EBs would enable engineered microenvironment to create functional pacemaker cells or electrophysiologically compatible hESC-CMs for cell replacement therapies. We have established antibiotic (Abx)-resistant hESC lines conferred by lentiviral vectors under the control of a cardiac-specific promoter. With simple Abx treatment, we easily isolated >95% pure hESC-CMs at various stages of differentiation from EBs. In the first year of this grant support and using the Abx selection system, we found that hESC-CMs isolated at early stages of differentiation without further contacts with non-cardiomyocytes (non-CMs) depicted arrested electrical maturation. The intracellular Ca2+-mediated automaticity developed very early and contributed to dominant automaticity throughout hESC-CM differentiation regardless of the presence or absence of non-CMs. In contrast, sarcolemmal ion channels evolved later upon further differentiation within EBs and their maturation required the interaction with non-CMs. In the second year, we further developed an add-back co-culture system to enable adding non-CMs back to early isolated hESC-CMs, which rescued the arrest of EP maturation. In the third no-cost extension year, we further successfully established the cocultures of human neural crest cell (NCC)-derivatives and early-purified hESC-CMs. We found that peripheral neurons derived from human NCCs exerted strong influences on the development of a specific subset of ion channel populations during early hESC-CM differentiation. Therefore, our study showed for the first time that non-CMs, especially neurons derived from NCCs, exert significant influences on the EP maturation of hESC-CMs during differentiation. Knowledge of this study will allow us to improve functional maturation of primitive hESC-CMs or to create neuro-coupled pacemaker cells before cell transplantation.

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