Production of erythrocytes, granulocytes and megakaryocytes by gp130 signalling and related molecular mechanisms.

通过 gp130 信号传导和相关分子机制产生红细胞、粒细胞和巨核细胞。

基本信息

批准号：
07407023
负责人：
NAKAHATA Tatsutoshi
金额：
$ 16.96万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1997
项目状态：
已结题

项目摘要

Eryhropoietin(EPO) is the primary humoral regulator of erythropoiesis and no other factor has previously been reported to support proliferation and terminal maturation of erythroid cells from hemopoietic stem cells. We found that stimulation of gp130 by a combination of recombinant human soluble IL-6 receptor (sIL-6R) and IL-6 can support proliferation, differentiation and terminal maturation of erythroid cells in the absence of EPO from purified human CD34^+ cells in suspensin culture containing stem cell factor (SCF) or flk2/flt3 ligand. The addition of anti-gp130 mAbs but not anti-EPO Ab to the same culture completely abrogated the generation of erythroid cells. These results clearly demonstrate that mature erythroid cells can be emerged from hemopoietic progenitors without EPO in vitro. HML/SE is a GM-CSF-or SCF-dependent cell line established from a children with M7 leukemia. Although HML/SE cells neither proliferate nor in the presense of EPO alone, these cells can proliferate an … More d produce hemoglobin by a combinaation of recombinant human sIL-6R and IL-6. SCF and activation of gp130 activated the human EPO receptor promoter and induced EPO receptor gene expression. Taken together, we speculate that HML/SE cells acquired responsiveness to EPO via the EPO receptor induced by SCF and gp130 signallings. Mutation analysis of putative transcription factor binding sites in the human EPO receptor promoter suggested that Spl, rather than the GATA-1 binding site, contributed to the induction of the hEPOR gene. While it is well documented that hematopoietic stem cells and primitive progenitors require both an early-actimg cytokine and a kineage specific cytokine to differntiate to a certain lineage, related mechanisms are not well understood. Together with the previous reports that human sera contain derectable levels of sIL-6R,IL-6 and SCF,normal erythropoiesis may be regulated physiologically by two different pathways ; the EPO-mediated signalling and a novel mechanism with gp130 in combination with c-KIT signalling. Less

促红细胞生成素 (EPO) 是红细胞生成的主要体液调节剂，之前没有报道过其他因子可以支持造血干细胞的红细胞增殖和终末成熟。我们发现重组人可溶性 IL-6 受体组合可刺激 gp130。 (sIL-6R) 和 IL-6 可在纯化人红细胞缺乏 EPO 的情况下支持增殖、分化和终末成熟含有干细胞因子 (SCF) 或 flk2/flt3 配体的悬浮素培养物中的 CD34^+ 细胞添加抗 gp130 mAb 但不添加抗 EPO Ab 完全消除了红系细胞的生成。 HML/SE 是从体外建立的 GM-CSF 或 SCF 依赖性细胞系，可以从没有 EPO 的造血祖细胞中产生成熟的红系细胞。患有 M7 白血病的儿童虽然 HML/SE 细胞在 EPO 单独存在的情况下也不会增殖，但这些细胞可以通过重组人 sIL-6R 和 IL-6 的组合以及 gp130 的激活来增殖并产生血红蛋白。激活人EPO受体启动子并诱导EPO受体基因表达，我们推测HML/SE细胞通过EPO受体诱导获得对EPO的反应性。通过 SCF 和 gp130 信号传导对人 EPO 受体启动子中假定的转录因子结合位点的突变分析表明，Spl（而不是 GATA-1 结合位点）有助于 hEPOR 基因的诱导，而有充分证据表明造血干。细胞和原始祖细胞需要早期活性细胞因子和运动特异性细胞因子才能分化为某种谱系，但相关机制尚不清楚，加上之前关于人类血清的报道。含有可调节水平的 sIL-6R、IL-6 和 SCF，正常红细胞生成可能通过两种不同的途径进行生理调节；EPO 介导的信号传导以及 gp130 与 c-KIT 信号传导相结合的新机制。