中文摘要：

目的观察p38丝裂原活化的蛋白激酶（MAPK）在高糖诱导的MC3T3-E1成骨细胞凋亡中的作用，并探讨其对凋亡相关信号分子caspase-3、bax及bcl-2表达的影响。方法构建靶向p38MAPK的shRNA慢病毒载体，将体外培养的MC3T3-El成骨细胞分为正常对照组（A组）、高糖组（B组）、p38MAPK-hRNA慢病毒转染组（c组）、信号转导阻断剂组（D组）和尢关shRNA转染组（E组）。RT-PCR检测细胞p38MAPKmRNA的表达，流式细胞术检测细胞凋亡，Western印迹检测p38MAPK、p-p38MAPK、caspase-3、bax、bcl-2蛋白水平，透射电镜观察细胞超微结构。结果构建靶向p38MAPK的shRNA慢病毒载体，并成功导入MC3T3-E1成骨细胞。与高糖组和无关转染组相比，p38MAPK-shRNA转染能显著抑制高糖诱导的MC3T3-El细胞p38MAPK过度活化，明显减少细胞的凋亡（P〈0．01）；同时，p38MAPK-shRNA转染及p38MAPK阻断剂明显降低MC3T3-E1细胞中p38MAPK、p-p38MAPK、caspase-3及促凋亡基因bax蛋白表达，上调捌亡抑制基因bcl-2，与高糖组和无关转染组相比，差异有统计学意义（P〈0．01，P〈0．05）。结论慢病毒介导p38MAPK靶向RNAT扰可通过抑制p38MAPK信号通路的活化，降低p-p38MAPK、caspase-3、bax表达，上凋bcl-2表达，最终抑制高糖所诱导的MC3T3-E1成骨细胞的凋亡。

英文摘要：

Objective To examine the role of p38MAPK in high glucose-induced apoptosis of osteoblast MC3T3-E1 cell line, and to investigate its effect on the expressions of apoptosis-related molecules including caspase3, bax, and bcl-2. Methods Tlle lentiviral vector containing short hairpin RNA targeting p38MAPK was constructed. The cultured osteoblast MC3T3-E1 cell were divided into 5 groups： normal control group （ A group） , high glucose group（ B group） , p38MAPK-shRNA transfection group （C group ） , signal transduction inhibitor group （D group）, and transfection with negative control siRNA group（ E group）. RT-PCR was used to determine the p38MAPK mRNA expression levels in MC3T3-E1 cells. Flow cytometry （FCM） was employed to detect the cell apoptotic percentage. The protein levels of apoptosis-related molecules p38MAPK, p-p38MAPK, caspasc-3, bax, and bcl-2 were assayed by Western blot. Ultrastructural alternation of MC3T3-E1 cell was observed under transmission electron microscopy （TEM）. Results The lentiviral vector containing short hairp in RNA targeting p38MAPK was successfully constructed and transfected into MC3T3-EI cells. RT-PCR result suggested that the siRNA targeting p38MAPK could effectively reduce the p38MAPK mRNA expression level induced by high glucose in MC3T3-EI cell line. FCM showed siRNA significantly decreased high glucose-induced apoptosis percentage of MC3T3-E1 cells（ P〈 0. 01 ）. Meanwhile, we also found the siRNA significantly attenuated the proteins levels of p38MAPK, p-p38MAPK, caspase-3, and gene bax induced by high glucose in MC3T3-E1 cells, whereas the protein level of gene bcl-2 was enhanced remarkably when compared with high glucose group and negative control siRNA group （P 〈 0.01, P 〈 0. 05）. Conclusion The iRNA targeting p38MAPK suppressed high glucose-induced MC3T3-E1 cell apoptosis via inhibiting the activation of p38MAPK signaling pathway, thereby reducing the expressions levels of p-p38MAPK,caspase-3 and gene bax, and up-regulating the level of