人参二醇组皂苷对再生障碍性贫血小鼠造血组织MAPK/ERK信号通路的诱导作用

摘要

AIM:To observe the effects of panaxadiol saponins(PDS)on up-regulation of MAPK/ERK signal pathway in bone marrow cells and increase in regulatory T(Treg)cells in spleen tissue of aplastic anemia(AA)mice,and to explore the mechanisms.METHODS:For preparation of immune-mediated AA model,BALB/c mice were exposed to sublethal dose(5.0 Gy)of [60Co]-γradiation, followed by transplantation of lymphocytes from DBA /2 donor mice. BALB/c mice(n=60)were randomly divided into 6 groups,including normal mouse group,AA model group,PDS treat-ment groups at low,medium and high doses,and cyclosporine group as positive control.PDS and cyclosporine were given by gavage for 14 d.The peripheral blood cell counts and bone marrow pathological examination were tested.The protein levels of MEK1/2,p-MEK1/2,ERK1/2 and p-ERK1/2 in the bone marrow cells were analyzed by Western blot and im-munohistochemistry experiment.Flow cytometry was used to detect the proportion of Treg cells in spleen tissue of each group.RESULTS:The peripheral blood cell counts were significantly decreased in AA mouse group as compared with nor -mal mouse group(P<0.05).The bone marrow sections showed markedly inhibition status of hematopoiesis and the de -crease in cellularity.In response to PDS treatment,the peripheral blood cell counts and Treg cells in the spleen tissues of AA mouse treated with PDS were significantly increased in a dose-dependent manner(P<0.05).Treatment with PDS at medium and high doses up-regulated the protein levels of MEK1/2,p-MEK1/2,ERK1/2 and p-ERK1/2 in the bone mar-row of AA mice(P<0.05).CONCLUSION:PDS is effective to enhance recovery of hematopoietic function in AA mice. This effect may be related to up-regulating multiple protein kinases of MAPK/ERK signal pathway in the bone marrow cells of AA mice.In addition,PDS has an impact on immune function of AA mice.%目的:观察人参二醇组皂苷(PDS)对免疫介导型再生障碍性贫血(简称再障)小鼠骨髓细胞MAPK/ERK信号通路蛋白激酶及脾脏调节性T细胞的诱导作用,探讨其治疗再障的作用机制.方法:用[60Co]-γ射线5.0 Gy全身照射BALB/c小鼠,后经尾静脉输入DBA/2小鼠的淋巴细胞悬液,制备免疫介导型再障小鼠模型.60只小鼠随机分为6组,即正常组,模型组,PDS低、中、高剂量组,环孢素组.不同浓度药物灌胃治疗14 d测定各组小鼠外周血象,观察骨髓病理切片,Western blot 法及免疫组织化学法测定骨髓细胞MEK1/2、p-MEK1/2、ERK1/2和p-ERK1/2的蛋白水平,流式细胞术检测脾脏调节性T细胞比例.结果:再障小鼠外周血全血细胞减少,骨髓呈抑制状态;PDS治疗能够显著升高再障小鼠外周血象,增加脾脏调节性T细胞比例,呈剂量依赖性(P<0.05).PDS中、高剂量组显著上调骨髓细胞MEK1/2、p-MEK1/2、ERK1/2和p-ERK1/2的蛋白水平(P<0.05).结论:PDS能有效促进造血,上调再障模型小鼠骨髓细胞MAPK/ERK信号通路多种蛋白激酶的表达,可能是PDS促进骨髓造血功能恢复的作用机制之一.另外,PDS对再障模型小鼠的免疫功能有一定的调节作用.