MyD118/CR6/GADD45 in Hematopoietic Homeostasis

描述（由申请人提供）：我们研究的长期目标是 更好地了解调节体内平衡的分子控制， 造血细胞本研究计划针对MyD 118/Gadd 45/CR 6 基因家族，在负生长控制中起作用。MyD 118/Gadd 45/CR 6家族成员也被遗传毒性剂快速诱导， 如终末分化和凋亡细胞因子， 由这些基因编码的基因在负生长控制中起关键作用。 MyD 118敲除小鼠和Gadd 45敲除小鼠的造血组织检查 显示细胞结构增加、存活率提高和细胞增殖增加 未成熟细胞的比例。MyD 118/Gadd 45/CR 6在乳腺癌中的表达失调 骨髓细胞系似乎加速了终末分化程序 及其相关的凋亡。我们的工作假设是MyD 118/Gadd 45/CR 6 在调节造血组织的稳态中发挥作用， 细胞周期和凋亡; MyD 118/Gadd 45/CR 6将改变细胞周期控制和存活，但也将 通过改变不同谱系和阶段的分布来表现 造血细胞的成熟。本研究的具体目的 AIM 1：MyD 118/Gadd 45/CR 6缺失分析。小鼠品系， 对于MyD 118和Gadd 45是无效的，并且杂合CR 6无效小鼠已经被 生成的. MyD 118/Gadd 45/CR 6表达被阻断后， 将在体内和体外评估造血区室， 短期和长期培养，以及对TGFb的应答， 应力MyD 118/Gadd 45/CR 6表达的缺失对细胞增殖能力的影响 与癌基因c-myc、c-myb、E2 F-1或ras协同作用以改变生长和/或 将确定原发性BM的分化。目标2：分析 MyD 118/Gadd 45/CR 6的表达失调。造血细胞系， 已经建立了表达可诱导的去调节的MyD 118/Gadd 45/CR 6， 分析MyD 118/Gadd 45/CR 6在生长和分化中的作用，以及 对压力和TGF β的反应。目标3：分析 MyD 11 S/Gadd 45/CR 6在凋亡途径中的作用，使用无细胞系统。无细胞 系统将有助于破译细胞凋亡，并提供一个辅助途径， 研究分析MyD 118、Gadd 45和CR 6的功能，以及 相互作用的蛋白质，我们可以专注于细胞凋亡，与细胞分离 循环停滞这些调查应有助于更好地了解 参与不同白血病发病机制的遗传事件， 对化疗和放疗的反应，最终帮助诊断， 预后和治疗。

DESCRIPTION (provided by applicant): The long-term goal of our research is to gain a better understanding of the molecular controls regulating homeostasis of hematopoietic cells. This research proposal focuses on the MyD118/Gadd45/CR6 gene family, which plays a role in negative growth control. The MyD 118/Gadd45/CR6 family members are rapidly induced by genotoxic agents, as well as by terminal differentiation and apoptotic cytokines, and the proteins encoded by these genes play pivotal roles in negative growth control. Examination of hematopoietic tissues in both MyD118 null and Gadd45 null mice revealed increased cellularity, enhanced survival and an increase in the proportion of immature cells. Deregulated expression of MyD 118/Gadd45/CR6 in myeloid cell lines appeared to accelerate the terminal differentiation program and its associated apoptosis. Our working hypothesis is that MyD 118/Gadd45/CR6 play a role in regulating homeostasis of hematopoietic tissues by modulating both the cell cycle and apoptosis; alterations in expression of MyD118/Gadd45/CR6 will modify cell cycle controls and survival, but also will manifest itself by changing the distribution of different lineages and stages of maturation of hematopoietic cells. The specific aims of this research proposal are: AIM 1: Analysis of loss of MyD118/Gadd45/CR6. Mouse strains that are null for MyD118 and Gadd45, and heterozygous CR6 null mice have been generated. The consequences of blocked expression of MyD118/Gadd45/CR6 within the hematopoietic compartment will be assessed, in vivo and in vitro, in both short term and long term cultures, as well as in response to TGFb, and to stress. The effect of loss of MyD118/Gadd45/CR6 expression on the ability to cooperate with oncogenes c-myc, c-myb, E2F-1 or ras, to alter growth and/or differentiation of primary BM will be determined. AIM 2: Analysis of deregulated expression of MyD118/Gadd45/CR6. Hematopoietic cell lines that express inducible deregulated MyD118/Gadd45/CR6 have been established to dissect the role of MyD118/Gadd45/CR6 in growth and differentiation, as well as in response to stress and TGFb. AIM 3: Analysis of the role for MyD11S/Gadd45/CR6 in apoptotic pathways, using cell free systems. Cell free systems will facilitate deciphering apoptosis, and provide an adjunct avenue of investigation to analyze the functions of MyD118, Gadd45, and CR6, as well as interacting proteins, where we can focus on apoptosis, segregated from cell cycle arrest. These investigations should contribute to a greater understanding of the genetic events involved in the pathogenesis of different leukemias and the response to chemo- and radiation therapy, ultimately aiding in diagnosis, prognosis and therapy.