热休克蛋白 90 通过 H₂S 介导对 PC12 细胞化学缺氧损伤的细胞保护作用。
Heat shock protein 90 mediates cytoprotection by H₂S against chemical hypoxia-induced injury in PC12 cells.
机构信息
Department of Physiology, Zhongshan Medical College, China.
出版信息
Clin Exp Pharmacol Physiol. 2011 Jan;38(1):42-9. doi: 10.1111/j.1440-1681.2010.05462.x.
- Increasing evidence indicates that hydrogen sulphide (H₂S) may serve as an important biological cytoprotective agent. Heat shock protein (Hsp) 90 can attenuate stress-induced injury. However, whether Hsp90 mediates the cytoprotective effect of H₂S against chemical hypoxia-induced injury in PC12 cells is not known. 2. In the present study, CoCl₂ (a chemical hypoxia mimetic) was used to treat PC12 cells to create a model of chemical hypoxia. To explore the role of Hsp90 in the cytoprotection afforded by H₂S against chemical hypoxia-induced injury, 2 μmol/L 17-allylaminogeldanamycin (17-AAG), a selective inhibitor of Hsp90, was administered for 30 min prior to preconditioning with 400 μmol/L NaHS, followed by chemical hypoxia. 3. Cobalt chloride reduced cell viability (by 52.7 ± 1.5%), increased PC12 cell apoptosis (by 42.1 ± 1.5%), induced reactive oxygen species (ROS) by 3.79% compared with control and induced the dissipation of mitochondrial membrane potential (MMP) by 2.56% compared with control. 4. Pretreatment of PC12 cells with 100-400 μmol/L sodium hydrosulphide (NaHS), an H₂S donor, for 3 h prior to exposure to 600 μmol/L CoCl₂ provided significant, concentration-dependant protection to PC12 cells against CoCl₂-induced cytotoxicity. Specifically, pretreatment of PC12 cells with 400 μmol/L NaHS decreased apoptosis to 16.77 ± 1.77% and blocked the CoCl₂-induced increase in ROS production and loss of MMP. 5. At 400 μmol/L, NaHS upregulated Hsp90 in a time-dependant manner (over the period 0-180 min). In addition to its effects on Hsp90 expression, NaHS pretreatment of PC12 cells augmented the overexpression of Hsp90 induced by 600 μmol/L CoCl₂ by 1.38-fold (P < 0.01). 6. Treatment of PC12 cells with 2 μmol/L 17-AAG for 30 min prior to NaHS pretreatment blocked the overexpression of Hsp90 induced by NaHS preconditioning, as evidenced by decreased cell viability (by 54.2 + 1.2%; P < 0.01), increased PC12 cell apoptosis (by 36.6 ± 1.2%; P < 0.01) and increasing ROS production. 7. The findings of the present study provide novel evidence that Hsp90 mediates H₂S-induced neuroprotection against chemical hypoxia-induced injury via anti-oxidant and anti-apoptotic effects.
越来越多的证据表明，硫化氢（H₂S）可能作为一种重要的生物细胞保护剂。热休克蛋白（Hsp）90 可以减轻应激诱导的损伤。然而，Hsp90 是否介导 H₂S 对化学缺氧诱导的 PC12 细胞损伤的细胞保护作用尚不清楚。
在本研究中，使用 CoCl₂（一种化学缺氧模拟物）处理 PC12 细胞以创建化学缺氧模型。为了探讨 Hsp90 在 H₂S 对化学缺氧诱导损伤的细胞保护作用中的作用，用 2μmol/L 17- 烯丙基氨基格尔德霉素（17-AAG）预处理 30min，然后用 400μmol/L NaHS 预处理，再进行化学缺氧处理。
氯化钴使细胞活力降低（降低 52.7%±1.5%），使 PC12 细胞凋亡增加（增加 42.1%±1.5%），与对照组相比，活性氧（ROS）增加 3.79%，线粒体膜电位（MMP）耗散增加 2.56%，与对照组相比。
用 100-400μmol/L 硫氢化钠（NaHS）预处理 PC12 细胞 3h，然后暴露于 600μmol/L CoCl₂，可显著提高 PC12 细胞对 CoCl₂诱导的细胞毒性的浓度依赖性保护。具体来说，用 400μmol/L NaHS 预处理 PC12 细胞，可将凋亡降低至 16.77%±1.77%，并阻断 CoCl₂诱导的 ROS 生成增加和 MMP 丢失。
在 400μmol/L 时，NaHS 以时间依赖的方式上调 Hsp90（在 0-180min 期间）。NaHS 预处理 PC12 细胞不仅影响 Hsp90 的表达，还可使 600μmol/L CoCl₂诱导的 Hsp90 过表达增加 1.38 倍（P<0.01）。
用 2μmol/L 17-AAG 预处理 PC12 细胞 30min，然后用 NaHS 预处理，可阻断 NaHS 预处理诱导的 Hsp90 过表达，表现为细胞活力降低（降低 54.2%±1.2%；P<0.01），PC12 细胞凋亡增加（增加 36.6%±1.2%；P<0.01）和 ROS 生成增加。
本研究结果提供了新的证据，表明 Hsp90 通过抗氧化和抗凋亡作用介导 H₂S 诱导的神经保护作用，防止化学缺氧诱导的损伤。
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