Basic Biology III
Human embryonic stem cells (hESC) have the potential to differentiate into all of the cell types that make up the body. Therefore, hESCs are promising tools for the treatment of degenerative diseases and for use in regenerative medicine. One highly desirable use of hESCs is to treat cardiovascular disease. Cardiovascular disease is a leading cause of mortality and morbidity in the state and country. Cardiovascular disease is caused by damage to blood vessels and the ability to repair this damage will improve disease outcomes. However, the ability to efficiently differentiate hESCs down cardiovascular lineages to generate large numbers of cells on a therapeutically relevant scale is lacking. The goal of this project is to develop a protocol for the differentiation of hESCs into vascular endothelial cells for the treatment of cardiovascular disease. Initially we will study the expression of vascular precursor cell genes during embryoid body formation from hESCs. Then, using gene transfer technology and regulatable gene expression of transcription factors that induce the vascular cell lineage, we will “tune” treated hESCs to optimize derivation of endothelial cells. We will then use these cells in a pre-clinical mouse model of ischemic heart damage to test their ability to integrate into the damaged tissue and restore circulatory function. Additionally, we will use these cells to study the molecular mechanisms of endothelial cell differentiation. These studies will increase our knowledge of hESC biology, endothelial cell development, and suggest methods for therapeutic use of hESCs.
Statement of Benefit to California:
Cardiovascular disease, including heart disease, heart failure, and stroke, is the number one cause of death in the state of California. Additionally, patients suffering with these conditions have decreased quality of life and represent a significant financial and emotional burden to both their families and the state in general. Novel treatments to block or reverse the progression of cardiovascular disease will benefit the patient physically, the caregiver emotionally, and relieve the financial burden to everybody. Recently, the use of human stem cells has been proposed as a therapeutic treatment for cardiovascular disease. Addition of these cells to injured tissue has the potential to prevent the loss of more tissue and regenerate lost tissue. However, before such treatments become available, the basic biology of these cells must be understood to maximize treatment efficiency and prevent unwanted side effects. We have identified a critical gene in the development of blood vessel precursor cells and propose to use it to optimize the generation of blood vessel cells from human embryonic stem cells. In addition we will carefully examine the molecular events underlying the transition from stem cell to blood vessel precursor. The potential knowledge gained from these studies has implications for controlling blood vessel overgrowth in diseases such as cancer and diabetic retinopathy as well as blood vessel dysfunction in diseases such as cardiovascular disease and peripheral artery disease. These findings will benefit the field of stem cell research and basic developmental biology with future research directions based on these results. In addition to the clinical and scientific applications of these studies, the young scientists being trained in the laboratory will provide the foundation for future research in academia or industry in California. The success of this project will enhance the already stellar reputation of the state of California as a leader in the stem cell field.
Project Synopsis: The goal of this proposal is to develop an efficient procedure for deriving vascular endothelial cells (EC) from human embryonic stem cells (hESC) for research and therapeutic applications. The applicant describes a recently identified transcription factor that mediates endothelial induction in a variety of species from fish to mammals. In the first aim, the expression and regulation of this factor’s human counterpart will be investigated as hESC are differentiated into EC using a standard protocol. In subsequent aims, the applicant will manipulate this factor in an effort to optimize EC derivation. Finally, the ability of the resulting cells to integrate into damaged tissue and restore circulatory function will be evaluated in a preclinical model of cardiac ischemia. Significance and Innovation: - Current methods for deriving EC from hESC are extremely inefficient and therefore impractical for therapeutic application. If successful, the proposed research could represent an important step towards generating sufficient quantities of EC to be useful for regenerative medicine. - Although methods exploited in this application would not lead to clinically useful cell populations due to regulatory challenges surrounding use of integrated gene constructs, the basic insights gained could enable future therapeutic approaches. - The rationale for improving endothelial induction by manipulating the proposed transcription factor is strongly supported by a convincing body of preliminary work. - The general approaches to be used are not particularly innovative but represent a valid path toward new discovery. Feasibility and Experimental Design: - The research plan is relatively straightforward and represents a logical extension of the applicant’s previous work. - Many of the proposed experiments appear entirely feasible. - Proposed work is supported by strong preliminary data. - The feasibility of the in vitro vascular differentiation and ischemia experiments is enhanced by the recruitment of appropriate collaborators. - While proficient with model organisms, the principal investigator has limited direct experience with hESC. - Discussion of potential problems and alternative solutions is minimal. Principal Investigator (PI) and Research Team: - The PI has a strong track record and considerable expertise in functional analysis of transcription factors associated with hematopoietic and vascular lineages in model organisms. - Excellent collaborators have been recruited to provide expertise in vascular differentiation as well as the modeling of cardiac ischemia. - The research environment and facilities are outstanding and conducive to the success of the project. Responsiveness to the RFA: - The proposed studies utilize human stem cells and address fundamental molecular mechanisms related to lineage specification and the determination of cell fate; consequently, proposal is entirely responsive to the RFA.