Calcium Signaling in Hematopoiesis

项目摘要 目前对造血干细胞特化（HSC）的分子机制的理解， 诱导多能干细胞（iPS细胞）的产生仍然有限。在本建议中，我们力求理解 钙信号，通过CaMKII，在斑马鱼胚胎HSC规格。压制一个 七个转录活性CaMKII基因，camk2g1，导致ezh2表达增加，功能性 多梳抑制复合物2（PRC2）的酶组分，抑制HSC特化。我们先征求 通过使用基因敲低技术来表征camk2g1在HSC特化中的作用， 药理学抑制剂。然后，我们试图确定如何增加ezh2表达在camk2g1缺陷， 胚胎改变对HSC特化重要的下游信号传导。初步结果显示， ezh2的表达抑制了下游靶基因（tgfbr 2和jag1a）的表达，导致细胞凋亡。 背主动脉腹侧壁的HSC。该提案的结果将为研究 这是从iPS细胞产生所有HSC谱系所必需的钙依赖性信号传导途径。

Project Summary Current understanding of the molecular mechanisms underlying hematopoietic stem cell specification (HSCs) to generate induced pluripotent stem cells (iPS cells) is still limited. In this proposal, we seek to understand the role of calcium signaling, acting through CaMKII, in HSC specification in zebrafish embryos. Suppression of one of the seven transcriptionally active CaMKII genes, camk2g1, leads to increased expression of ezh2, the functional enzymatic component of the polycomb repressive complex 2 (PRC2), inhibiting HSC specification. We first seek to characterize the role of camk2g1 in HSC specification through use of genetic knockdown techniques and pharmacological inhibitors. We then seek to determine how increased expression of ezh2 in camk2g1 deficient embryos alters downstream signaling important for HSC specification. Preliminary results suggest increased ezh2 expression inhibits downstream expression of target genes (tgfbr2 and jag1a) resulting in apoptosis of HSCs in the ventral wall of the dorsal aorta. The results from this proposal will provide novel insight into the calcium-dependent signaling pathways necessary to generate all lineages of HSCs from iPS cells.