Dr. Momoko Yoshimoto
The University of Texas Health Science Center at Houston
McGovern Medical School
Institute of Molecular Medicine
Center for Stem Cell Research and Regenerative Medicine
My lab has two main aims: 1. Elucidating innate B-1a cell development process and its mechanism of self-renewal ability, 2. Understanding the multiple waves of hematopoiesis including the first hematopoietic stem cell (HSC) emergence that occurs in the mouse embryo.
- B-1 cells are innate B cells and develop from fetal liver progenitor cells, not adult bone marrow HSCs, thus have self-renewal ability to maintain themselves for life. We have previously identified the earliest origin of B-1a cells in the extra-embryonic yolk sac at a pre-HSC stage. Our aim is to understand the pathway of B-1a cell development independent of HSCs, and possibly some derived from HSCs. We also examine the molecular mechanisms to maintain B-1a cells in adult life.
- In the mouse embryo, all definitive hematopoietic cells are produced from endothelial cells, called hemogenic endothelial cells. It is critically important to understand the mechanisms that allow temporal and a special emergence of different types of hematopoietic cells (such as B-1 specific progenitors, multipotent progenitors, pre-HSCs, and adult-HSCs) in the extra-embryonic yolk sac or para-aortic region (AGM region). This knowledge would be utilized for the development of stem cell therapy using iPS cells in the future.
Procedures: We dissect embryos at various stages and culture them with stromal cells to evaluate hematopoietic differentiation potentials. We perform transplantation assays and gene expression profiling in each cell population separated by multi-color cell sorting. Various transgenic/knockout mouse models are utilized for the purpose of lineage tracing and lineage-specific gene deletion.