神经生长因子对小鼠红系造血的影响及内在机制研究

本研究探讨神经生长因子（NGF）对红系造血的影响及内在机制。采用流式细胞术、祖细胞集落测定、血细胞计数、实时荧光定量PCR及酶联免疫吸附分析法（ELISA），对经大腿肌肉注射NGF一定时间后小鼠骨髓细胞的（BMC）增殖周期、BFU—E、CFU—E集落产率、外周血红细胞相关指标、肾脏EPO水平、骨髓细胞GM—CSF、脾脏EPO受体（EPOR）mRNA的表达及血清中EPO，GM—CSF和IL-1浓度进行检测，并观察培养体系中加入不同浓度的NGF时BFU—E、CFU—E集落产率的变化及与EPO、IL-3的关系。结果表明：注射NGF（7．5μg／kg）持续7天，骨髓细胞中S＋G2／M期细胞比例、CFU-E和BFU—E集落产率、脾EPOR mRNA量显著高于注射生理盐水的对照组。持续13到19天，外周血网织红细胞比例、红细胞数、血红蛋白含量也有升高；在体外CFU—E培养中，无论是否加入EPO，加入的NGF均能剂量依赖性地促进集落的形成，且只加入NGF组的集落产率显著高于只加入EPO组。在BFU—E培养中加入NGF和IL-3时，集落产率显著高于加入EPO和IL-3组。结论：NGF可能通过提高造血细胞对EPO的反应性并可激活造血细胞上与EPO作用后一样的信号通路，进而促进骨髓细胞进入有丝分裂，促进造血干细胞向红系方向分化，促进BFU—E和CFU—E的形成，增加外周血中网织红细胞、红细胞、血红蛋白含量。

Effect of Nerve Growth Factor on Erythropoiesis in Mice and It's Underlying Mechanism

This study was aimed to explore the effect of nerve growth factor (NGF) on erythropoiesis and to elucidate the underlying mechanism.Using flow cytometry,colony forming assay,blood cell counter,fluorescent real-time quantitation PCR,and enzyme-linked immunosorbent assay (ELISA),the changes in the bone marrow cells (BMCs) proliferation cycle,CFU-E and BFU-E counts,the peripheral blood erythroid related parameters,kidney EPO,BMC GM-CSF,spleen EPO receptor (EPOR) mRNA expression,and serum EPO,GM-CSF,and IL-1 concentrations were all determied after NGF was injected intramuscularly into the thigh of mice,meanwhile the change of BFU-E and CFU-E counts and its relationship wim EPO,IL-3 were investigated.The results indicated that the cell proportion in S+G2/M phase,the CFU-E and BFU-E counts of BMCs and the spleen EPOR mRNA expression in injection of NGF (7.5 μg/kg) for 7 clays were significantly higher than that in injection of physiological saline for 13-19 days;red blood cell,hemoglobin,and reticulocyte counts increased as well.In vitro,NGF stimulated a dose-dependent increase of CFU-E colonies formation in the semisolid culture system with or without exogenous EPO:the colony counts in the system wim NGF alone were significantly higher than that in the system with exogenous EPO alone.The BFU-E counts in the system with exogenous NGF and IL-3 were significantly higher than that in the system with exogenous EPO and IL-3.It is concluded that the NGF promotes the responsibility of hematopoietic cells to EPO and activates the same signal transduction pathway as EPO in hematopoietic cells,and then accelerates the BMCs into mitosis,the HSCs differentiating into erythroid cells,and CFU-E and BFU-E formation.