TRPM8通过cAMP-PKA/UCP4信号调控氧糖剥夺/复糖复氧诱导的神经元凋亡

目的探究TRPM8在氧糖剥夺/复糖复氧诱导神经元PC12细胞凋亡中的分子机制。方法体外建立氧糖剥夺/复糖复氧模 型模拟脊髓缺血再灌注损伤，流式细胞仪检测PC12细胞的凋亡，RT-PCR和western blot检测TRPM8、UCP4和cAMP、p-PKA、 Bax、Bcl-2 的表达变化；向PC12 细胞分别加入AMTB（TRPM8 阻断剂）和转染UCP4 质粒，western blot 检测cAMP、p-PKA、 UCP4、Bax、Bcl-2的表达水平；抑制PKA信号，检测UCP4、Bax、Bcl-2的蛋白表达水平。结果氧糖剥夺/复糖复氧导致脊髓神经 元PC12 细胞发生凋亡，TRPM8 过表达，UCP4 表达下降，抑制cAMP-PKA 信号。抑制TRPM8 表达，则细胞凋亡减少， cAMP-PKA信号被激活，且UCP4的表达有所恢复。抑制TRPM8和cAMP-PKA信号，UCP4的表达减少，细胞凋亡增加。结论 在氧糖剥夺/复糖复氧模型中，PC12细胞TRPM8过表达，且通过cAMP-PKA/UCP4诱导神经元PC12细胞凋亡。

TRPM8 mediates PC-12 neuronal cell apoptosis induced by oxygen-glucose deprivation through cAMP-PKA/UCP4 signaling

Objective To explore the molecular mechanism responsible for apoptosis of PC-12 neuronal cells induced by oxygen-glucose deprivation (OGD). Methods PC12 cells were exposed to OGD for 24 h to simulate ischemia-reperfusion injury. Flow cytometry was employed detect the cell apoptosis, and the expresions of TRPM8, UCP4, cAMP and PKA in the exposed cells were detected with RT-PCR and Western blotting. The changes in the expressions of Bax, Bcl-2, cAMP, PKA and UCP4 proteins were detected in the exposed cells in resposne to inhibition of TRPM8 and cAMP-PKA signal or over-expression of UCP4. Results OGD for 24 induced obvious apoptosis in PC-12 cells and caused TRPM8 over-expression and inhibition of UCP4 and cAMP-PKA signaling. Inhibiting TRPM8 expression reduced the cell apoptosis and up-regulated cAMP, p-PKA and UCP4 in the cells exposed to OGD. In cells exposed to OGD, inhibition of TRPM8 and cAMP-PKA signaling suppressed the expressio of UCP4 and increased the cell apoptosis. Conclusion TRPM8 mediates OGD-induced PC12 cell apoptosis through cAMP-PKA/UCP4 signaling.