高压氧暴露对离体大鼠骨髓间充质干细胞周期和分化的影响

Effects of hyperbaric oxygen on cell cycle and differentiation of rat mesenchymal stem cell in vitro

目的探讨高压氧暴露对大鼠骨髓间充质干细胞（ratmesenchymal stem cells，rMSC）生长周期及定向分化的影响。方法选用健康成年Wistar大鼠，冲洗股骨及胫骨骨髓腔得到rMSC，分离纯化后取3～4代细胞，用0．2、0．3MPa氧气暴露1h，分别立即处理和24h后处理，用流式细胞术测定生长周期；同法经高压氧暴露后用10μm5-氮杂胞苷（5-azacytidine，5-aza）诱导分化，查看向心肌样细胞分化的效果。结果0．3MPa氧气暴露立即处理组S期细胞减少，24h后恢复到正常水平，其余各组细胞生长周期无明显变化。高压氧暴露后，5-aza诱导rMSC向心肌样细胞分化，心肌细胞特异性表面标记心肌钙蛋白T（cardiactroponinT，cTNT）及α-肌动蛋白（α-sarcomericactin）均有阳性表达，但各组间无明显差异。结论0．3MPa高压氧暴露对rMSC细胞周期的影响较0．2MPa暴露明显，但对rMSC分化的影响不显著。

Objective To investigate the influences of hyperbaric oxygen （HBO）on cell cycle and differentiation of rat mesenehymal stem cells （rMSC）. Methods One month male Wistar rats were ehoosed as subjects, rMSCs were separated from femur and cnemis by flushing out with low glucose DMEM. rMSCs of he 3rd and 4th generation were purified and exposed to 0.2 MPa and 0.3 MPa HBO for one hour. A part of them were digested at once and after 24 hours respectively to examined cell cycle by flow eytometry. And the other part of them were induced by 10 μml 5-azaeytidine for two weeks and then the results of differentiation of cardiomyocytes were observed. Results The percentage of cells in the stage of S in the group digested at once after exposed to 0.3 MPa HBO group decreased obviously compared with the other group and retrieved normal level after 24 h, the cell cycles in the other groups weren＇t different. 5-azacytidine could induce rMSCs into cardiomyocytes in every group. Troponin and α-actin which were cadiocyte specificity surface marker were all masculine expresstion in every group, but there was no obviously different among groups. Conclusions Compared with 0.2 MPa HBO exposed group, there is a more significant effect of 0.3 MPa HBO on cell cycle, and under this condition, HBO has a quiet effect on differentiation of rMSC.