SIGNAL TRANSDUCTION THROUGH TH ERYTHROPOIETIN RECEPTOR

描述（申请人的描述）：红细胞生成是一种高度调节的 多能造血祖细胞 细胞分化为红系前体细胞， 促红细胞生成素和其他生长因子的反应。 的存在 促红细胞生成素和c-Kit受体对这一过程的发生至关重要 正常情况下 然而，目前尚不清楚这些受体是否特异性地 “指导”祖细胞沿着特定谱系分化，或 如果他们只是让细胞存活足够长的时间， 沿着微分一个随机规划。 本申请试图解决生理环境中的这个问题， 整个小鼠，利用胚胎干细胞技术， 逆转录病毒感染初级造血祖细胞。 的作用 将通过观察各种细胞因子的表达对细胞凋亡的影响来检查细胞凋亡。 抗凋亡基因如Bcl-2、Bcl-x、CrmA和c-IAP在细胞膜上表达。 除祖细胞外，BaF 3和HCD-57细胞系的分化 来自胎儿肝脏 基于串联质谱的蛋白质 测序方法（MALDI-MS/MS）将用于鉴定信号传导 当EpoR被Epo激活时，与EpoR结合的分子。以来 几种红细胞疾病中的分子/发育缺陷， 真性红细胞增多症和红白血病尚不清楚， 这些研究将导致识别可能有缺陷的分子， 或提供对发育异常的见解 导致骨髓增生 最后，信号的性质 将研究真性红细胞增多症的缺陷。 将确定是否 造血细胞对Epo的高反应性是由改变的 表达模式或突变影响负功能 信号传导调节剂如SH-PTP 1和CIS（细胞因子诱导的SH 2 域）。

DESCRIPTION (Applicant's Description): Erythropoiesis is a highly regulated developmental process during which pluripotent hematopoietic progenitor cells become committed to differentiate into erythroid precursors in response to erythropoietin and other growth factors. The presence of erythropoietin and c-Kit receptors is critical for this process to occur normally. It is not known, however, whether these receptors specifically "instruct" progenitor cells to differentiate along a particular lineage or if they merely allow the cells to survive long enough so they can then differentiate along a stochastic program. This application seeks to address this issue in the physiological setting of the whole mouse, utilizing embryonic stem cell technology as well as the use of retroviruses to infect primary hematopoietic progenitors. The role of apoptosis will be examined by looking at the effect of expression of various a n ti-apoptotic genes such as Bcl-2, Bcl-x, CrmA, and c-IAPs on the differentiation of BaF3 and HCD-57 cell lines in addition to progenitors derived from fetal livers. Tandem mass spectrometry based protein sequencing approaches (MALDI-MS/MS) will be utilized to identify signaling molecules that a s s ociate with the EpoR when it is activated by Epo. Since the m o lecular/developmental defect in several red cell disorders such as polycythemia vera and erythroleukemias is not yet known, it is likely that these studies will lead to identification of molecules that may be defective in these diseases or provide insights into the developmental abnormality that leads to bone marrow hyperplasia. Finally, the nature of the signaling defect in polycythemia vera will be studied. It will be determined if the hyperresponsiveness of hematopoietic cells to Epo results from altered expression patterns or mutations affecting the function of negative modulators of signaling such as SH-PTP1 and CIS (Cytokine Inducible SH2 domain).