p38 MAPK、Caspase-s介导PTH诱导PC12细胞凋亡机制的研究

Parathyroid hormone_(1-34)-induced apoptosis in neuronal rat PC12 cells via p38MAPK,Caspase-s

目的甲状旁腺激素(PTH1-34)对PC12细胞作用和p38MAPK、Caspase-s在PTH1-34对PC12细胞凋亡中作用机制。方法应用CCK-8法测定PTH对PC12细胞生长抑制率,通过细胞形态学、乳酸脱氢酶(LDH)和流式细胞仪方法检测细胞损伤,RT-PCR测定p38 mRNA的表达,通过Western blot检测细胞中p38磷酸化丝裂原活化蛋白激酶(MAPK)及caspase-3蛋白的变化。结果 CCK-8法测定PTH抑制PC12细胞生长;透射电镜可见细胞核呈固缩状、凋亡小体出现等典型的凋亡形态学改变;流式细胞仪可见细胞凋亡率增多;LDH渗出量增多等。PTH1-34可明显上调p38 mRNA的表达,并可明显地促进PC12细胞磷酸化p38MAPK与Caspase-3的蛋白表达。结论 PTH可诱导PC12细胞凋亡,p38MAPK和Caspase-s共同介导参与PTH致PC12细胞凋亡。

Objective To study the effect and mechanism of the neuronal apoptosis induced by p38 MAPK and Caspase-3 after PTH1-34 injury in rat pheochromocytoma( PC 12) cells.Methods Cell viability was analyzed by cell counting kit-8 assay. Apoptosis was measured by using DNA and apoptosis fragmentation agarose gel electrophoresis,Morphological observation and flow cytometry as well as LDH assays. p38 MAPK mRNA expression was determined by RT-PCR. p38 MAPKs and caspase-3 proteins were detected by Western blotting. Results MTT assays indicated that 0.01,0.1,1.0μmol / L PTH1-34 induced apoptosis in PC 12 cells in a time-dependent fashion and a does-dependent fashion. PTH1-34 induced up-expression of p38 MAPK mRNA. It altered the phosphorlation state of mitogen-activated protein of p38 MAPK. PTH1-34 promoted the activation of caspase-3. Conclusion Exogenous PTH1-34 induces apoptosis in rat PC12 cells by a mechanism probably associated with changes in the activation of p38 MAPK and caspase-3.