植物雌激素金雀异黄酮通过p38MAPK通路促进骨髓间充质干细胞向成骨细胞分化

目的研究丝裂原激活的蛋白激酶(m itogen-activatedprote in k inases,MAPKs)的亚型p38 MAPK在植物雌激素金雀异黄酮(Gen iste in)促进小鼠骨髓间充质干细胞(bone m ar-row-derived m esenchym al stem cells,BMSCs)向成骨细胞分化过程中的作用。方法BMSCs用无酚红-αMEM(含经活性碳吸附的10%FBS、β-磷酸甘油、维生素C)培养,先用Gen iste in处理细胞,观察BMSCs向成骨细胞分化情况,然后用SB203580(p38 MAPK通路阻断剂)以及PD98059(p44/42MAPK通路阻断剂)阻断相应的通路后,再用Gen iste in处理细胞,观察BMSCs向成骨细胞分化情况,并同时观察上述处理后MAPK通路的变化。测定碱性磷酸酶(ALP)活性和钙(Ca)沉积量反映BMSCs向成骨细胞分化状况,用W esternb lot来检测MAPK通路是否激活。结果Gen iste in(0.01,0.1,1μmol.L-1)剂量依赖性增加小鼠BMSCs细胞内ALP活性和细胞外Ca沉积量,并同时引起p38MAPK通路的激活和p44/42MAPK通路的抑制。SB203580预处理能减弱Gen iste in刺激引起的p38MAPK通路的激活并同时阻止Gen iste in诱导的BMSCs向成骨细胞分化。结论Gen iste in在0.01~1μmol.L-1剂量范围内可通过p38MAPK通路促进小鼠BMSCs向成骨细胞分化。

Phytoestrogen Genistein induces osteoblastic differentiation of mouse bone marrow-derived mesenchymal stem cells through p38 MAPK

Aim To investigate the role of p38 mitogen-activated protein kinases(MAPKs) in genistein-induced osteoblastic differentiation of mouse bone marrow-derived mesenchymal stem cells(BMSCs).Methods Mouse BMSCs cultured in phenol red-free α-MEM containing 10% V/V FBS,were added β-glycerophosphate and ascorbic acid for inducing osteoblastic differentiation,and treated with 0.01~1 μmol·L~(-1) genistein and/or SB203580 and PD98059.The temporal sequence of osteoblastic differentiation in BMSCs cultures was assayed by measuring alkaline phosphatase activity(ALP) and calcium deposition.The MAPK phosphorylation level was detected by Western-blot.Results Genistein(0.01~1 μmol·L~(-1)) showed a dose-dependent effect on osteoblastic differentiation as evidenced by increased alkaline phosphatase(ALP) activity and calcium deposition in mouse BMSCs cultures.Genistein(1 μmol·L~(-1))-induced osteoblastic differentiation of BMSCs was diminished by p38 MAPK inhibitor but not the p44/42 MAPK inhibitor.The effects of Genistein were associated with rapid and sustained activation of p38 MAPK in the BMSCs cultures,which was blocked by SB203580(1 μmol·L~(-1)).In contrast,Genistein treatment resulted in inactivation of p42/44MAPK,which was further attenuated by PD98059(25 μmol·L~(-1)).Conclusion p38 MAPK plays an important role in genistein-induced osteoblastic differentiation of mouse BMSCs cultures.