Heart Disease

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

Building Cardiac Tissue from Stem Cells and Natural Matrices

Funding Type: 
New Faculty II
Grant Number: 
RN2-00921
ICOC Funds Committed: 
$1 706 255
Disease Focus: 
Heart Disease
Stem Cell Use: 
Embryonic Stem Cell
oldStatus: 
Active
Public Abstract: 
Congestive heart failure afflicts 4.8 million people, with 400,000 new cases each year. Myocardial infarction (MI), also known as a "heart attack", leads to a loss of cardiac tissue and impairment of left ventricular function. Because the heart does not contain a significant number of multiplying stem, precursor, or reserve cells, it is unable to effectively heal itself after injury and the heart tissue eventually becomes scar tissue. The subsequent changes in the workload of the heart may, if the scar is large enough, deteriorate further leading to congestive heart failure. Many stem cell strategies are being explored for the regeneration of heart tissue, however; full cardiac tissue repair will only become possible when two critical areas of tissue regeneration are addressed: 1) the generation of a sustainable, purified source of functional cardiac progenitors and 2) employment of cell delivery methods leading to functional integration with host tissue. This proposal will explore both of these 2 critical areas towards the development of a living cardiac patch material that will enable the regeneration of scarred hearts.
Statement of Benefit to California: 
The research proposed in expected to result in new techniques and methodology for the differentiation of stem cell-derived cardiomyocytes and delivery methods optimal for therapeutic repair of scarred heart tissue after a heart attack. The citizens of California could benefit from this research in three ways. The most significant impact would be in the potential potential for new medical therapies to treat a large medical problem. The second benefit is in the potential for these technologies to bring new usiness ventures to the state of California. The third benefit is the stem cell training of the students and postdocs involved in this study.
Progress Report: 
  • The proposed project aims to develop cardiac tissue for enhancing the regeneration of damaged heart. The progress in the first year involved generation of cardiac cells from stem cells, developing fabrication techniques for stem cell differentiation, and exporing cell interactions with various biodegradable materials.
  • Progress towards developing heart tissue for repairing damaged/diseaesed hearts includes stem cell differentiation towards cells that make up heart tissue and blood vessels, optimization of methods for cell expansion and cell-cell integration to generate functional tissues, and preliminary investigations of delivery materials fabrication.
  • We have optimized cardiac cell numbers from embyronic stem cells and generated a cardiac patch for delivery of these cardiac cells into damaged myocardium.
  • The aims for this study are to 1) develop methods for generating highly efficient numbers of cardiovascular cells from stem cells, and then 2) develop methods for packaging the cells into tissue-like implantable materials for repair of dead tissue following a heart attack. The final aim 3) was to examine the repair/restorative ability of the developed product in a damaged animal heart.
  • This year (4th year of the grant) was very productive. We have highly efficient methods for generating both heart (70% purity) and blood vessel cells (90% purity) and have developed a sophisticated design for packaging these into heart tissue-like materials. The animal studies are underway and initial data is promising.
  • The aim of this research proposal was to develop cardiac tissue for heart repair. Aim 1 focused on the generation of cardiac cells from stem cells. Aim 2 looks at biomaterials and patterning for building the complex multicellular integrated tissue. Aim 3 examined the ability of these tissues to repair a damaged heart. During this last year of the grant, we have successfully generate large numbers of cardiac cells from stem cells and have generated "sheets" of these cardiac cells. The animal studies on the cell injections and material injection show some success in the repair of heart tissue, but expect that the fully integrated heart tissue, once implanted, will be superior to cells or material alone.

Metabolic regulation of cardiac differentiation and maturation

Funding Type: 
Basic Biology V
Grant Number: 
RB5-07356
ICOC Funds Committed: 
$1 124 834
Disease Focus: 
Heart Disease
Stem Cell Use: 
Embryonic Stem Cell
iPS Cell
oldStatus: 
Closed
Public Abstract: 
Cells in the body take up nutrients from their environment and metabolize them in a complex set of biochemical reactions to generate energy and replicate. Control of these processes is particularly important for heart cells, which need large amounts of energy to drive blood flow throughout the body. Not surprisingly, the nutritional requirements of heart cells are very different than those of stem cells. This proposal will investigate the metabolism of pluripotent stem cells and how this changes during differentiation to cardiac cells. We will determine which nutrients are important to make functional heart cells and use this information to optimize growth conditions for producing heart cells for regenerative medicine and basic biology applications. We accomplish this by feeding cells nutrients (sugar, fat) labeled with isotopes. As these labeled molecules are consumed, the isotopes are incorporated into different metabolites which we track using mass spectrometry. This advanced technique will allow us to see how sugars and fat are metabolized inside stem cells and cardiac cells obtained through differentiation. We will also study the electrical activity of these heart cells to ensure that adequate nutrients are provided for the generation of cells with optimal function. Ultimately, this project will lead to new methods for producing functional heart cells for regenerative medicine and may also lead to insights into how cardiac cells malfunction in heart disease.
Statement of Benefit to California: 
Heart disease is one of the leading causes of death in California. As a result, much of the regenerative medicine community in the state and the many Californians suffering from heart failure are interested in obtaining functional heart cells from stem cells. Our work will identify the most important nutrients required to coax stem cell-derived heart cells to behave like true adult heart cells. This information will make more effective cell models for researchers and companies to study how this disease affects heart cell metabolism. Since enzymes are highly targetable with drugs, the basic scientific findings from our work will be of great interest to California biotechnology companies and can stimulate job growth in the state. Our findings will also provide insight into very specific types of genetic heart disease, and this work may lead to additional grants from federal funding sources, bringing about additional revenue and job growth in California. A better understanding of how different nutrients influence heart cell function may provide guidance into new treatment strategies for heart disease. Finally, this work will highlight the importance of diet, nutrition, and healthy heart function, providing useful information relating to public health.

A new paradigm of lineage-specific reprogramming

Funding Type: 
Basic Biology IV
Grant Number: 
RB4-06035
ICOC Funds Committed: 
$1 708 560
Disease Focus: 
Heart Disease
Stem Cell Use: 
Directly Reprogrammed Cell
Cell Line Generation: 
iPS Cell
oldStatus: 
Active
Public Abstract: 
Recently, we devised and reported a new regenerative medicine paradigm that entails temporal/transient overexpression of induced pluripotent stem cell based reprogramming factors in skin cells, leading to the rapid generation of “activated” cells, which can then be directed by specific growth factors and small molecules to “relax” back into various defined and homogenous tissue-specific precursor cell types (including nervous cells, heart cells, blood vessel cells, and pancreas and liver progenitor cells), which can be expanded and further differentiated into mature cells entirely distinct from fibroblasts. In this proposal, combined with small molecules that can functionally replace reprogramming transcription factors as well as substantially improve reprogramming efficiency and kinetics, we aim to further develop and mechanistically characterize chemically defined, non-integrating approaches (e.g., mRNA, miRNA, episomal plasmids and/or small molecule-based) to robustly and efficiently reprogram skin fibroblast cells into expandable heart precursor cells. Specifically, we will: determine if we can use non-integrating methods to destabilize human fibroblasts and facilitate their direct reprogramming into the heart precursor cells; characterize of heart cells generated by the direct programming methods, both in the tissue culture dish and in a mouse model of heart attack; and characterize newly identified reprogramming enhancing small molecules mechanistically.
Statement of Benefit to California: 
This study will develop and mechanistically characterize a new method of generating safe patient specific heart cells that could be useful in treating heart failure which afflicts millions of Californians and accounts for billions of dollars in healthcare spending annually. Additionally, the small molecules discovered in this study could be good candidates for future drug development as well as being broadly useful for other regenerative medicine applications. These advances could also be a platform for new personalized medicine/ cell banking businesses which could bring economic growth in addition to improving the health of Californians.
Progress Report: 
  • During the reporting period, we have made very significant progress toward the following research aims: (1) Using the Oct4-based reprogramming assay system established, we were able to screen for and identify small molecules that can replace the other three genes in the Cell-Activation and Signaling-Directed (CASD) lineage conversion paradigm for reprogramming fibroblasts into cardiac lineage. (2) Using in-depth assays, we have examined the process using lineage-tracing methods and characterized those Oct4/small molecules-reprogrammed cardiac cells in vitro. (3) Most importantly, we were able to identify a baseline condition that appears to reprogram human fibroblasts into cardiac cells using defined conditions.

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.

Epigenetic regulation of human cardiac differentiation

Funding Type: 
Basic Biology IV
Grant Number: 
RB4-05901
ICOC Funds Committed: 
$1 708 560
Disease Focus: 
Heart Disease
Stem Cell Use: 
Embryonic Stem Cell
iPS Cell
oldStatus: 
Active
Public Abstract: 
Each cell type in our body has its own identity. This identity allows a heart cell to contract repetitively, and a brain cell to conduct nerve impulses. Each cell type gains its identity by turning on or off thousands of genes that together give the cell its identity. Understanding how these sets of genes are regulated together as a cell gains its identity is important to be able to generate new cells in disease. For example, after a heart attack, heart muscle dies, leaving scar tissue and a poorly functioning heart. It would be very useful to be able to make new heart muscle by introducing the right set of instructions into other cells in the heart, and turn them into new heart muscle cells. One way that many genes are turned on or off together is by a cellular mechanism called epigenetic regulation. This global regulation coordinates thousands of genes. We plan to understand the epigenetic regulatory mechanisms that give a human heart muscle cell its identity. Understanding their epigenetic blueprint of cardiac muscle cells will help develop strategies for cardiac regeneration, and for a deeper understanding of how cells in our body acquire their individual identities and function.
Statement of Benefit to California: 
This research will benefit the state of California and its citizens by helping develop new approaches to cardiac regeneration that will be more efficient than current approaches, and amenable to drug-based approaches. In addition, the knowledge acquired in these studies will be important not only for heart disease, but for any other disease where reprogramming to regenerate new cells is desirable. The mechanisms revealed by this research will also lead to new understanding of the basis for congenital heart defects, which affect several thousand Californian children every year, and for which we understand very little.
Progress Report: 
  • We have made considerable progress on this project, which is aimed at understanding how genes are controlled during the conversion of human stem cells into heart cells. We have been able to use advanced techniques that allow us to make millions of human heart cells in a dish from "Induced Pluripotent Stem Cells" (known as iPS cells), which are cells derived from skin cells that have properties of embryonic stem cells. We are now using genome engineering techniques to insert a mutation that is associated with human congenital heart defects. We are now starting to map the chromatin marks that will tell us how heart genes are turned on, while genes belonging to other cell types are kept off. This "blueprint" of a heart cell will help us understand how to make better heart cells to repair injured hearts, and will allow us to model human congenital heart disease in a human experimental system.

Preclinical Development and First-In-Human Testing of [REDACTED] in Advanced Heart Failure

Funding Type: 
Disease Team Therapy Planning I
Grant Number: 
DR2-05434
ICOC Funds Committed: 
$106 239
Disease Focus: 
Heart Disease
oldStatus: 
Closed
Public Abstract: 
This application seeks to bring to the clinic a new treatment for myocardial disease based on human embryonic stem cell (hESC) derived cardiomyocytes. hESC-cardiomyocytes have the unique potential to address the underlying cause of heart disease by repopulating areas of damaged myocardium (heart tissue) with viable cardiac cells. This therapeutic approach represents a potential breakthrough in heart disease treatment, serving one of the most intractable, largest, and most costly unmet clinical needs in the U.S. Currently available heart disease treatments have demonstrated ability to slow progression of the disease, but to date none can restore the key underlying defect in heart failure, a loss of contractile function. Cell therapy approaches have generated excitement for their unique potential to play a curative role in myocardial disease through the restoration of lost contractile and/or circulatory function. hESC-cardiomyocytes are unique amongst the cell therapy approaches in that they are a human cardiomyocyte (heart muscle cell) product; replacing damaged myocardium with viable heart cells which can integrate and form fully functional cardiac tissue. This approach has the potential to significantly halt or reverse cardiac functional decline. These benefits can significantly impact patient medication requirements and hospitalizations associated with ongoing cardiac decline, key drivers of the enormous health care costs associated with heart failure. The proposed scope of this project includes activities leading up to and including a regulatory filing with the FDA to initiate clinical testing of hESC-cardiomyocytes for the treatment of heart failure, as well as the enrollment and initial follow-up of a small cohort of patients in a first-in-human trial. The proposed product has completed extensive process development, product characterization, and preclinical (animal model studies) proof-of-concept studies to date. The scope of the proposed research includes: (i) performance of key preclinical safety and efficacy studies to enable entry to clinical testing (ii) manufacture of material for use in preclinical studies, development work, and clinical testing (iii) development and qualification of assays for product characterization, and (iv) preparation for and execution of initial clinical studies.
Statement of Benefit to California: 
The proposed project has the potential to benefit the state of California through 1) providing improved medical outcomes for patients with heart disease, 2) increasing California’s leadership in the emerging field of stem cell research, and 3) preserving and creating high quality, high paying jobs for Californians. Heart disease is one of the most intractable, wide-spread, and fatal diseases in the U.S. More than 5.8 million Americans currently suffer from heart failure; close to 60% of heart failure patients die within 5 years of diagnosis. Although specific statistics are not available for California, they are likely similar to those nationwide, with incidence of more than 10 in 1000 individuals >65 years of age (AHA, 2010). Currently available heart disease therapies have demonstrated the ability to slow disease progression, but to date none can restore the key underlying defect leading to heart failure, a loss of cardiac contractile function. Cell therapy, an approach to regenerate or repair the damaged heart with new cells, addresses this fundamental need, and is considered one of the most important and promising frontiers for the treatment of heart disease. Although multiple other cell therapy products are currently being evaluated for the treatment of heart disease, human embryonic stem cell derived cardiomyocytes have unique potential to address the underlying defect of loss of contractile activity in heart failure, by replacing scarred or damaged heart tissue with new, functional human heart cells to restore cardiac function. California has a history of leadership in biotechnology, and is emerging as a leader in the development of stem cell therapeutics. Cutting edge stem cell research, in many cases funded by CIRM, is already underway in academic research laboratories and biotechnology companies throughout the state. The proposed project has the potential to further increase California’s leadership in the field of stem cell therapeutics through the performance of the first clinical testing of an hESC-derived cardiac cell therapy. The applicant has been located in California since its inception, and currently employs nearly 200 full-time employees at its California headquarters with more than 50% of employees holding an advanced degree. These positions are highly skilled positions, offering competitive salaries and comprehensive benefits. The successful performance of the proposed project would enable significant additional jobs creation as the program progresses through more advanced clinical testing.

A Novel Engineered Niche to Explore the Vasculogenic Potential of Embryonic Stem Cells

Funding Type: 
New Faculty I
Grant Number: 
RN1-00566
ICOC Funds Committed: 
$2 108 683
Disease Focus: 
Heart Disease
Stem Cell Use: 
Adult Stem Cell
Embryonic Stem Cell
oldStatus: 
Closed
Public Abstract: 
Cardiovascular diseases account for an estimated $330 billion in health care costs each year, afflict 61.8 million Americans, and will account for more than 1.5 million deaths in the U.S. this year alone. A number of these diseases are characterized by either insufficient blood vessel growth or damage to the existing vessels, resulting in inadequate nutrient and oxygen delivery to the tissues. The most common clinical example of this is a heart attack, or myocardial infarction, typically caused by blockage of a coronary artery. The resulting ischemia (reduced blood flow) induces irreversible damage to the heart, leaving behind a non-functional scar tissue. Efforts to restore blood flow to ischemic tissues have largely focused on the delivery of protein growth factors (called pro-angiogenic molecules) that stimulate new capillary growth. An alternative approach is to deliver an appropriate cell type that can either accelerate the recruitment of host vessels or can differentiate into a functional vasculature directly. While adult stem cells have shown promising potential with respect to the former, the potential of embryonic stem cells (ESCs) with respect to either of these two possibilities remains unclear. Therefore, this proposal seeks to: 1.) Utilize a novel, highly tunable, 3D engineered niche to investigate how changes in multiple instructive signals coordinately govern the differentiation of ESCs into capillary vessels; 2.) Exploit knowledge gained from basic studies using this model system to generate a purified population of ESC-derived endothelial progenitor cells (EPCs) and test their potential to repair ischemia in vivo. Specifically, in Aim 1, we propose to further develop and characterize our artificial engineered niche for fundamental studies on ESC fate decisions. Aim 2 will use this system to test two competing hypotheses, namely that: 1.) ESCs can facilitate capillary morphogenesis in an indirect manner, in much the same way as adult stem cells; or 2.) ESCs can be directed down an endothelial-specific lineage by manipulating one or more instructive signals. Finally, Aim 3 will utilize our engineered niche to generate a purified population of ESC-derived EPCs and then test their ability to enhance perfusion in an animal model. Successful completion of these proposed aims may transform the clinical use of stem cells for cardiovascular disease and other ischemic pathologies by enabling identification of those factors and conditions which promote vessel formation. The versatile artificial engineered niche developed here will also yield a new tool that could enormously benefit efforts to screen the combinatorial effects of promising therapeutic compounds. Completion of the planned studies will greatly facilitate the PI’s long-term goal of developing “instructive” biomaterials and strategies to direct tissue repair.
Statement of Benefit to California: 
Human embryonic stem cells (hESCs) are pluripotent stem cells that can theoretically give rise to every cell type in the human body. Their potential use for the treatment of human diseases has been heralded with great fanfare and even some controversy. However, their therapeutic potential has yet to be realized due to an incomplete fundamental understanding of the factors that govern their differentiation. This proposal describes studies intended to assess the ability of hESCs to develop into blood vessels; in particular, capillary networks that are responsible for the delivery of oxygen and essential nutrients to all tissues in the human body. This focus is motivated by the fact that cardiovascular disease accounts for an estimated $330 billion in health care costs each year, afflicts 61.8 million Americans, and will account for more than 1.5 million deaths in the United States this year alone. It is the number one killer in this country and in California. Since many cardiovascular diseases are characterized by either insufficient blood vessel growth or damage to the existing vessels, a therapy based on hESCs could have enormous benefit to the citizens of California, the United States, and the rest of the world. Therefore, this proposal has two primary goals. First, we seek to develop a novel technology to systematically investigate the influence of multiple instructive signals on the ability of hESCs to differentiate into capillary vessels. Second, we propose to exploit knowledge gained from the basic studies using this technology to generate a purified population of hESCs and test their potential to repair ischemia (lack of blood flow) in an animal model. Successfully achieving these goals will benefit the citizens of California in three significant ways. First, our efforts may help to transform the clinical use of stem cells, not only for cardiovascular disease but other diseases as well, by enabling identification of those factors and conditions which promote hESC differentiation. Second, the versatile technology developed here will yield a powerful new tool that could enormously benefit California’s biotechnology companies in their efforts to screen the combinatorial effects of promising therapeutic compounds. Third, we expect the proposed studies to directly benefit 8-10 researchers in training and indirectly trickle down to hundreds of undergraduate students [REDACTED] enrolled in courses taught by the PI. This final benefit may perhaps have the most significant long-term economic impact by training and inspiring future leaders to pursue research and development positions in California.

Induction of cardiogenesis in pluripotent cells via chromatin remodeling factors

Funding Type: 
New Faculty II
Grant Number: 
RN2-00903
ICOC Funds Committed: 
$2 847 600
Disease Focus: 
Heart Disease
Stem Cell Use: 
Embryonic Stem Cell
iPS Cell
oldStatus: 
Closed
Public Abstract: 
Heart disease is one of the biggest killers in the civilized world, and as populations age, this trend will increase dramatically. Currently the only way to treat failing hearts is with expensive and relatively ineffective drugs, or by heart transplantation. Ideally, we would like to be able to regenerate sick or dead heart tissue. The best strategy would be to make new heart cells that match the patients' cells (to avoid rejection), and inject them into diseased heart so that they could regenerate the sick heart.Unfortunately, current strategies that are planned to do so are ineffectual. We wish to attempt to generate heart cells from human embryonic stem cells, or skin-derived "induced pluripotent cells" by "reprogramming" the stem cells into heart cells. This would be accomplished by turning on heart genes that normally are off in stem cells and seeing if this turns stem cells into heart cells. If this approach is successful, these newly generated stem cells could be used for regenerative therapies in the future.
Statement of Benefit to California: 
Heart disease is the leading killer of adults in the Western world. Hundreds of thousands of people in the US die of heart failure of sudden cardiac death each year. Largely, this is because inadequate therapies exist for the repair or treatment of the diseased heart. Our goal is to develop a means to efficiently convert pluripotent stem cells, including induced pluripotent cells (iPS cells) into new heart cells that could be used therapeutically to help regenerate healthy heart tissue. The results of our studies will help develop new technology that is likely to contribute to the California biotechnology industry. Our studies will develop technologies that can be used by biotechnology companies and researchers who wish to develop regenerative medicine therapies in a clinical setting. We are working closely with California companies to develop new microscopes, assay devices, and analytical software that could be the basis for new product lines or new businesses. If therapies do come to fruition, we anticipate that California medical centers will be leading the way. The most important contribution of this study will be to improve the health of Californians. Heart disease is a major cause of mortality and morbidity, resulting in billions of dollars in health care costs and lost days at work. Our goal is to contribute research that would ultimately improve the quality of life and increase productivity for millions of people who suffer from heart disease.
Progress Report: 
  • We hypothesized that human embryonic stem cells (hESCs) or induced pluripotent stem cells (iPS cells, which are derived from skin or other adult cells) can be efficiently reprogrammed to become heart cells using a combination of factors that includes proteins that unwind DNA. To test this hypothesis, we proposed three specific aims. For each we have achieved significant progress. In progress toward our first aim, we have been able to enhance cardiac differentiation of mouse iPS cells by 20%, and have devised strategies to increase this success rate. Our second aim was directed at understanding how important the chromatin remodeling factor, Baf60c, was in the induction of heart cells from pluripotent cells. We have made significant progress in this regard, mostly in developing the complex genetic tools required to investigate this important question. The third aim was to understand how Baf60c and its collaborating factors work to enhance heart cell formation. Again, we have had considerable success in early experiments that indicate that we will be able to address these questions fully in the remaining years of the granting period. Overall, our first year of funding has allowed us to move rapidly forward in understanding how to propel a stem cell toward becoming a heart cell; these results will be important to understand how heart cells are made in the body, and how their genesis can be harnessed using the power of stem cells.
  • We have been studying ways to understand how heart cells form from stem cells, and how we could help make the process more efficient, to generate new heart cells for patients with damaged hearts due to heart attacks. We have focused on the finding that cellular machines that unwind DNA from chromosomes, so-called chromatin remodeling factors, are important for turning on heart genes. To date we have been generating the important biological tools required for these studies. These include stem cells in which some of these chromatin genes have been inactivated, as well as DNA constructions that will be inserted into embryonic stem cells to attempt to induce them to become heart cells. In parallel we have been working towards using these factors to transform other types of cells, such as skin cells, into cardiomyocytes; in collaboration with our colleagues we have made significant progress towards this goal, and are now investigating the importance of the chromatin remodeling complexes in this process. Our progress has been excellent, and we are confident that we are making great strides towards regenerative medicine in the context of heart disease.
  • We have been studying ways to understand how heart cells form from stem cells, and how we could help make the process more efficient, to generate new heart cells for patients with damaged hearts due to heart attacks. We have focused on the finding that cellular machines that unwind DNA from chromosomes, so-called chromatin remodeling factors, are important for turning on heart genes. To date we have been generating the important biological tools required for these studies. These include stem cells in which some of these chromatin genes have been inactivated, as well as DNA constructions that will be inserted into embryonic stem cells to attempt to induce them to become heart cells. In parallel we have been working towards using these factors to transform other types of cells, such as skin cells, into cardiomyocytes; in collaboration with our colleagues we have made significant progress towards this goal, and are now investigating the importance of the chromatin remodeling complexes in this process. Our progress has been excellent, and we are confident that we are making great strides towards regenerative medicine in the context of heart disease.
  • In the last year, we have made significant progress on this project, which aims to understand how heart cells can be produced from pluripotent cells. We have been able to understand the gene program that is controlled by a so-called chromatin remodeling protein, a protein that unwinds DNA to allow genes to be turned on. This protein, called Baf60c, turns on many of the genes that give a heart cell its basic functions, like beating. We have also created stem cell -based tools that will allow us in the final year of this project to identify the partner proteins that allow Baf60c to function, and where in our genome Baf60c turns genes on.
  • During the tenure of this award, we have made some exciting discoveries about how genes are regulated during the process of heart cell formation from embryonic stem cells. In particular, we focused our efforts on a group of proteins that regulate other genes using a process called chromatin remodeling. We discovered that one such chromatin remodeling protein is required for genes that are specific to the heart to be turned on in heart cells. We also discovered new proteins that are also important for the formation of the heart. In studying these chromatin remodeling proteins in an embryonic stem cell system, we identified how these proteins turn on the "right" set of genes in the earliest stages of commitment of stem cells to heart cell progenitors. Finally, we identified the nature of the group of proteins that work together as part of chromatin remodeling "complexes", which for the first time tells us how these proteins assemble together to regulate heart genes. These results have paved the way for studies aimed at creating new heart cells, and have opened up some exciting new possibilities to improve this process.

Induced Pluripotent Stem Cells for Cardiovascular Diagnostics

Funding Type: 
New Cell Lines
Grant Number: 
RL1-00639
ICOC Funds Committed: 
$1 708 560
Disease Focus: 
Heart Disease
Toxicity
Stem Cell Use: 
iPS Cell
Cell Line Generation: 
iPS Cell
oldStatus: 
Closed
Public Abstract: 
Our objective is to use induced pluripotent stem (iPS) cell technology to produce a cell-based test for long QT syndrome (LQTS), a major form of sudden cardiac death. Nearly 500,000 people in the US die of sudden cardiac death each year. LQTS can be triggered by drug exposure or stresses. Drug-induced LQTS is the single most common reason for drugs to be withdrawn from clinical trials, causing major setbacks to drug discovery efforts and exposing people to dangerous drugs. In most cases, the mechanism of drug-induced LQTS is unknown. However, there are genetic forms of LQTS that should allow us to make iPS cell–derived heart cells that have the key features of LQTS. Despite the critical need, current tests for drug-induced LQTS are far from perfect. As a result, potentially unsafe drugs enter clinical trials, endangering people and wasting millions of dollars in research funds. When drugs causing LQTS such as terfenadine (Seldane) enter the market, millions of people are put at serious risk. Unfortunately it is very difficult to know when a drug will cause LQTS, since most people who develop LQTS have no known genetic risk factors. The standard tests for LQTS use animal models or hamster cells that express human heart genes at high levels. Unfortunately, cardiac physiology in animal models (rabbits and dogs) differs from that in humans, and hamster cells lack many key features of human heart cells. Human embryonic stem cells (hESCs) can be differentiated into heart cells, but we do not know the culture conditions that would make the assay most similar to LQTS in a living person. These problems could be solved if we had a method to grow human heart cells from people with genetic LQTS mutations, so that we know the exact test conditions that would reflect the human disease. This test would be much more accurate than currently available tests and would help enable the development of safer human pharmaceuticals. Our long-term goal is to develop a panel of iPS cell lines that better represent the genetic diversity of the human population. Susceptibility to LQTS varies, and most people who have life-threatening LQTS have no known genetic risk factors. We will characterize iPS cells that have well-defined mutations that have clinically proven responses to drugs that cause LQTS. These iPS cell lines will be used to refine testing conditions. To validate the iPS cell–based test, the results will be directly compared to the responses in people. These studies will provide the foundation for an expanded panel of iPS cell lines from people with other genetic mutations and from people who have no genetically defined risk factor but still have potentially fatal drug-induced LQTS. This growing panel of iPS cell lines should allow for testing drugs for LQTS more effectively and accurately than any current test.
Statement of Benefit to California: 
Heart disease is the leading killer of adults in the Western world. Nearly 500,000 people in the US die of sudden cardiac death each year. Our goal is to develop a cell-based test to screen for drugs that can cause sudden cardiac death. Drug-induced cardiac side effects are the most common reason for withdrawal of drugs from clinical trials, causing major setbacks to drug discovery efforts. Therefore our test we will improve the safety of pharmaceuticals. Our test will also reduce the change that a drug in development will fail during clinical trials, thereby decreasing the financial risk for pharmaceutical companies. The results of our studies will help develop new technology that is likely to contribute to the California biotechnology industry. Our studies will develop multiple lines of iPS cells with unique genetic characteristics. These cell lines could be valuable for biotechnology companies and researchers who are screening for drug compounds. We are working closely with California companies to develop new microscopes, assay devices, and analytical software that could be the basis for new product lines or new businesses. If therapies do come to fruition, we anticipate that California medical centers will be leading the way. The most important contribution of this study will be to improve the health of Californians. Heart disease is a major cause of mortality and morbidity, resulting in billions of dollars in health care costs and lost days at work. Our goal is to contribute research that would ultimately improve the quality of life and increase productivity for millions of people who suffer from heart disease.
Progress Report: 
  • Nearly 500,000 people in the US die of sudden cardiac death each year, and long QT syndrome (LQTS) is a major form of sudden cardiac death. LQTS can be triggered by drug exposure or stresses. Drug-induced LQTS is the single most common reason for drugs to be withdrawn from clinical trials, causing major setbacks to drug discovery efforts and exposing people to dangerous drugs. In most cases, the mechanism of drug-induced LQTS is unknown. However, there are genetic forms of LQTS that should allow us to make iPS cell–derived heart cells that have the key features of LQTS. Our objective is to produce a cell-based test for LQTS with induced pluripotent stem (iPS) cell technology, which allows adult cells to be “reprogrammed” to be stem cell–like cells.
  • Despite the critical need, current tests for drug-induced LQTS are far from perfect. As a result, potentially unsafe drugs enter clinical trials, endangering people and wasting millions of dollars in research funds. When drugs that cause LQTS, such as terfenadine (Seldane), enter the market, millions of people are put at serious risk. Unfortunately, it is very difficult to know when a drug will cause LQTS, since most people who develop LQTS have no known genetic risk factors. The standard tests for LQTS use animal models or hamster cells that express human heart genes at high levels. Unfortunately, cardiac physiology in animal models (rabbits and dogs) differs from that in humans, and hamster cells lack many key features of human heart cells. Human embryonic stem cells (hESCs) can be differentiated into heart cells, but we do not know the culture conditions that would make the assay most similar to LQTS in a living person. These problems could be solved if we had a method to grow human heart cells from people with genetic LQTS mutations, so that we know the exact test conditions that would reflect the human disease. This test would be much more accurate than currently available tests and would help enable the development of safer human pharmaceuticals.
  • Our long-term goal is to develop a panel of iPS cell lines that better represent the genetic diversity of the human population. Susceptibility to LQTS varies, and most people who have life-threatening LQTS have no known genetic risk factors. We will characterize iPS cells with well-defined mutations that have clinically proven responses to drugs that cause LQTS. These iPS cell lines will be used to refine testing conditions. To validate the iPS cell–based test, the results will be directly compared to the responses in people. These studies will provide the foundation for an expanded panel of iPS cell lines from people with other genetic mutations and from people who have no genetically defined risk factor but still have potentially fatal drug-induced LQTS. This growing panel of iPS cell lines should allow for testing drugs for LQTS more effectively and accurately than any current test.
  • To meet these goals, we made a series of iPS cells that harbor different LQTS mutations. These iPS cells differentiate into beating cardiomyocytes. We are now evaluating these LQTS cell lines in cellular assays. We are hopeful that our studies will meet or exceed all the aims of our original proposal.
  • Nearly 500,000 people in the US die of sudden cardiac death each year, and long QT syndrome (LQTS) is a major form of sudden cardiac death. LQTS can be triggered by drug exposure or stresses. Drug-induced LQTS is the single most common reason for drugs to be withdrawn from clinical trials, causing major setbacks to drug discovery efforts and exposing people to dangerous drugs. In most cases, the mechanism of drug-induced LQTS is unknown. However, there are genetic forms of LQTS that should allow us to make iPS cell–derived heart cells that have the key features of LQTS. Our objective is to produce a cell-based test for LQTS with induced pluripotent stem (iPS) cell technology, which allows adult cells to be “reprogrammed” to be stem cell–like cells.
  • Despite the critical need, current tests for drug-induced LQTS are far from perfect. As a result, potentially unsafe drugs enter clinical trials, endangering people and wasting millions of dollars in research funds. When drugs that cause LQTS, such as terfenadine (Seldane), enter the market, millions of people are put at serious risk. Unfortunately, it is very difficult to know when a drug will cause LQTS, since most people who develop LQTS have no known genetic risk factors. The standard tests for LQTS use animal models or hamster cells that express human heart genes at high levels. Unfortunately, cardiac physiology in animal models (rabbits and dogs) differs from that in humans, and hamster cells lack many key features of human heart cells. Human embryonic stem cells (hESCs) can be differentiated into heart cells, but we do not know the culture conditions that would make the assay most similar to LQTS in a living person. These problems could be solved if we had a method to grow human heart cells from people with genetic LQTS mutations, so that we know the exact test conditions that would reflect the human disease. This test would be much more accurate than currently available tests and would help enable the development of safer human pharmaceuticals.
  • Our long-term goal is to develop a panel of iPS cell lines that better represent the genetic diversity of the human population. Susceptibility to LQTS varies, and most people who have life-threatening LQTS have no known genetic risk factors. We will characterize iPS cells with well-defined mutations that have clinically proven responses to drugs that cause LQTS. These iPS cell lines will be used to refine testing conditions. To validate the iPS cell–based test, the results will be directly compared to the responses in people. These studies will provide the foundation for an expanded panel of iPS cell lines from people with other genetic mutations and from people who have no genetically defined risk factor but still have potentially fatal drug-induced LQTS. This growing panel of iPS cell lines should allow for testing drugs for LQTS more effectively and accurately than any current test.
  • To meet these goals, we have made a series of iPS cells that harbor different LQTS mutations. These iPS cells differentiate into beating cardiomyocytes. We are now evaluating these LQTS cell lines in cellular assays. We are hopeful that our studies will meet or exceed all the aims of our original proposal.
  • Cardiac arrhythmias are a major cause of morbidity and mortality. Yet we lack appropriate human tissue models to develop new therapies of this deadly disease. Despite the importance of this disease, the current in vitro models utilize overexpressed channels in fibroblasts that do not accurately recapitulate human cardiac myocytes. With our CIRM funding, we greatly improved our in vitro models by using cardiomyocytes derived from human induced pluripotent stem cells (iPS cells) from donors who harbor cardiac arrhythmia mutations. We enrolled a series of research subjects with genetic forms of LQTS. All participants in our study signed a consent form that was approved by the UCSF human subjects committee. We found that iPS cell–derived cardiomyocytes developed disease-related phenotypes in vitro that could be readily demonstrated by electrophysiological techniques. Such measurements enabled the pharmacological characterization of underlying mechanisms of disease and may point to potential novel therapies. The CIRM funding has allowed our laboratory develop new methods for human disease modeling in iPS cell–derived tissues. This project served as a critical catalyst for human disease research that would otherwise be impossible.

Chemical Genetic Approach to Production of hESC-derived Cardiomyocytes

Funding Type: 
Comprehensive Grant
Grant Number: 
RC1-00132
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.

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