Basic Biology IV
Neural crest is a transient cell population that is ectodermal in origin, but upon delamination from the neural tube acquires a remarkably broad differentiation potential and ability to migrate throughout the body to give rise to craniofacial skeleton and connective tissue, peripheral nervous system, pigment cells, and certain cardiac structures. Aberrant neural crest development is associated with a broad variety of congenital malformations, known as neurocristopathies, which often manifest in deafness and complex craniofacial defects, and which include a large variety of syndromes, as well as non-syndromic manifestations, such as cleft lip and palate, one of the most common congenital defects. Very little is known about molecular mechanisms facilitating remarkable developmental plasticity of the neural crest, in part due to the transient, migratory nature of these cells. Indeed, regulatory events that accompany neural crest formation occur at 3 to 6 weeks of human gestation and are largely inaccessible for studies in an embryonic context. To overcome this limitation we developed a human ESC-based in vitro model, which recapitulates gene expression, migratory potential and differentiation characteristics of the neural crest. Here we propose to use this model to study gene regulatory mechanisms underlying different steps of neural crest formation and their perturbations in disease.
Statement of Benefit to California:
Our research will provide insights into fundamental mechanisms of human development, generate tools for advancement of new stem cell therapies based on directed differentiation of stem cell populations, characterize novel human regulatory sequences that can be utilized in personalized medicine and enhance understanding of genetic basis of common congenital malformations, such as cleft lip/palate. Other tangible and immediate benefits for the community include: - contribution to the training of new workforce in human stem cell technologies - creation of new intellectual property that would benefit local institution and by extension local community. - boosting local economy since we buy our supplies from local vendors whenever possible.
Neural crest (NC) is a very important developmental tissue with ability to generate cells across all germ layers. NC cells are also involved in a variety of diseases referred to as neurocristopathies. This project aims to examine the gene regulatory networks underlying normal and pathological development of human NC cells, with particular emphasis on understanding the role of transcriptional enhancers from a set/family of major NC cell enhancer binding proteins. The role of binding proteins will then subsequently be explored in the pathogenesis of one of the NC disorders known as branchio-oral-facial syndrome (BOFS). Significance and Innovation - Although the binding protein of interest is critical for understanding basic neural crest biology and pathology of the diseased state, it is also involved in non-neural ectoderm and could confound the proposed analysis. - Reviewers felt that a major weakness of this proposal is the lack of functional validation for any novel target identified to be important for NC development. - Contrary to what the proposal suggests, a reviewer pointed out that the gene regulatory networks in NC development and the function of critical components have already been studied extensively. Feasibility and Experimental Design - Although reviewers thought that sorting the desired population for the RNA-seq is straightforward, some were concerned that chip sequencing on FAC sorted cells takes very long to produce the necessary number of cells and would only yield incremental results. - Reviewers felt that the proposal makes assumptions that genes identified from hESC-derived NC cells will have the same or similar functions as has been described in other model systems, which may not be the most relevant to the mammalian system. - Reviewers agreed that the proposal provides no functional validation assays, and although potential binding protein targets will be identified, it is unclear how they will be subsequently analyzed. Principal Investigator (PI) and Research Team - The PI is an outstanding investigator with an excellent record of productivity relevant to this proposal. - Excellent research team with appropriate expertise to conduct the proposed study. Responsiveness to the RFA - The proposed research was viewed as responsive to the RFA.
- This application scored below the initial scientific merit funding line, no programmatic reason to fund the application was proposed, and the GWG voted to place the application in Tier 3, Not Recommended for Funding.
- Ali Brivanlou