敲除GPS2基因对小鼠胚胎原始造血的影响

Effects of GPS2 deficiency on murine primitive hematopoiesis

目的明确敲除G蛋白通路抑制因子2(GPS2)基因对小鼠胚胎原始造血的影响。方法分离GPS2敲除小鼠胚胎外周血细胞,利用瑞氏吉姆萨染色观察血细胞形态,流式细胞术分析原始红细胞分化情况;分离敲除小鼠卵黄囊细胞,利用集落形成实验分析造血分化能力,流式细胞术分析造血干细胞的产生。结果GPS2敲除胚胎外周血部分原始红细胞细胞膜皱缩、形态畸形,未成熟原始红细胞(CD71^+Ter119^-)比例明显提高。GPS2敲除与野生型卵黄囊中造血干细胞比例基本相同,产生红系集落形成单位(CFU-E)、红系爆式集落形成单位(BFU-E)、粒细胞巨噬细胞集落形成单位(CFU-GM)及混合集落形成单位(CFU-GEMM)等集落的数量无明显差异。结论敲除GPS2不影响卵黄囊造血干细胞产生及集落形成,但抑制原始红细胞的分化成熟并导致原始红细胞形态畸形。

Objective To investigate the effects of GPS2 deficiency on murine primitive hematopoiesis.Methods Peripheral blood cells were isolated from GPS2 knockout(KO)and wild type(WT)embryos.The morphology of the primitive erythrocytes was examined by Wright-Giemsa stained cytospin preparations and the erythroid differentiation was analyzed by flow cytometry.In addition,the single cell suspensions of yolk sacs were prepared.The hematopoietic differentiation ability of the yolk sacs was examined by colony-forming unit assays and the proportion of hematopoietic stem cells(HSC,CD34^+c-Kit^+CD41^+)in the yolk sacs was determined by flow cytometry.Results Cytospin preparation of peripheral blood revealed that some GPS2 knockout primitive erythrocytes displayed a deformed shape,in contrast to the smooth,round shape of erythrocytes from WT embryos.The proportion of the immature primitive erythrocytes(CD71^+Ter119^-)in GPS2 KO peripheral blood was higher than in WT.GPS2 KO yolk sacs had a similar proportion of HSCs and generated similar numbers of CFU-E,BFU-E,CFU-GM and CFU-GEMM compared to WT yolk sacs.Conclusion GPS2 deficiency inhibits the primitive erythroid differentiation and leads to the deformed shape of primitive erythrocytes.However,knockout of GPS2 has no effect on the proportion of HSC in the yolk sacs and does not affect colony formation ability of the yolk sacs.