硫化氢抑制葡萄糖调节蛋白78减轻6-OHDA诱导的PC12细胞损伤

Hydrogen sulfide attenuates 6-OHDA-induced injury by inhibition of the GRP78 pathway in PC12 cells

目的：探讨硫化氢（H2S）是否通过改变葡萄糖调节蛋白78（GRP78）的表达参与其对抗6-羟基多巴胺（6-OHDA）诱导PC12细胞损伤的保护作用。方法应用具有神经毒性的6-OHDA损伤PC12细胞为帕金森病细胞模型，以硫氢化钠（NaHS）作为H2S的供体；应用CCK-8比色法检测细胞存活率；DFCH-DA染色检测细胞内活性氧（ROS）的水平；Rh123染色检测细胞线粒体膜电位（MMP）；Western blot检测GRP78的表达。结果200μmol/L的6-OHDA引起PC12细胞的存活率显著降低，ROS生成增加及MMP降低，且诱导了GRP78的高表达。应用25~400μmol/L的NaHS预处理30 min，呈浓度依赖性抑制6-OHDA引起的细胞存活率降低，其中400μmol/L的NaHS作用最明显，此浓度也可以显著减少6-OHDA引起的ROS增多，提高MMP，同时明显抑制6-OHDA诱导的GRP78高表达。结论 H2S具有抗6-OHDA氧化应激损伤的PC12细胞保护作用，抑制内质网应激分子GRP78的表达可能是其机制之一。

Objective To investigate whether hydrogen sulfide （H2S）involved in the protection of PC12 cells against 6-hydroxydopamine（6-OHDA）-induced injury by changing the glucose-regulated protein 78（GRP78）expression. Meth-ods 6-OHDA was used to establish the Parkinson disease model in PC12 cells with dopaminergic neurons characteris-tics.Sodium hydrosulfide（NaHS）was used as a H2S donor.The viability of PC12 cells was measured by CCK-8 assay.The level of reactive oxygen species （ROS）in PC12 cells was measured by DCFH-DA staining.The mitochondrial membrane potential （MMP）was analyzed by rhodamine 123 staining.The expression of GRP78 was evaluated by Western blot. Re-sults 200 μmol/L 6-OHDA induced a decrease in cell viability and overproduction of ROS as well as dissipation of MMP in PC12 cells.6-OHDA induced the upregulation of GRP78 expression.When PC12 cells were treated with NaHS 30 min before 6-OHDA treatment a decrease in viability of PC12 cells induced by 6-OHDA was concentration-depen-dently blocked by NaHS （25-400μmol/L）.Pretreatment with NaHS at 400μmol/L obviously inhibited the dissipation of MMP and overproduction of ROS induced by 200 μmol/L 6-OHDA.Furthermore,NaHS preconditioning obviously di-creased the upregulation of GRP78 expression induced by 6-OHDA. Conclusion H2S protected PC12 cells against 6-OHDA-induced oxidative stress injury and inhibiting the expression of GRP78 may be one of the mechanism under-lying cytoprotection induced by H2S preconditioning.