慢性束缚应激对雄性小鼠下丘脑腹内侧核神经元NADPH氧化酶表达及ROS生成的影响

Effects of chronic restraint stress on NADPH oxidase expression and ROS generation in the hypothalamic ventromedial nucleus in male mice

目的观察慢性束缚应激对小鼠下丘脑腹内侧核(VMH)烟酰胺腺嘌呤二核苷酸磷酸盐(NADPH)氧化酶表达及活性氧(ROS)氧化应激损伤的影响。方法实验分为对照组和慢性束缚应激组,每周记录小鼠24 h摄食量和体重变化,用二氢乙啡啶(DHE)染色法检测VMH ROS的生成,HE染色观察VMH形态学变化,免疫组化检测VMH NOX2、p47phox和RAC1的表达,Western blot法检测下丘脑PKCα、NOX2、p47phox和RAC1的表达。结果与对照组比较,慢性束缚应激能明显降低小鼠24 h摄食量和体重;DHE染色结果显示,慢性束缚应激能明显增加小鼠VMH神经元ROS的生成;HE染色结果显示,慢性束缚应激能明显导致VMH神经元损伤;免疫组化和蛋白印迹结果显示,与对照组比较,慢性束缚应激小鼠VMH神经元PKCα、NOX2、p47phox和RAC1的表达明显增加。结论慢性束缚应激可导致小鼠VMH神经元损伤,其机制可能与增加VMH神经元NADPH氧化酶介导的ROS生成增多有关。

Objective To explore the effects of chronic restraint stress on NADPH oxidase （NOX） expression and the reactive oxygen species （ROS） generation in the hypothalamic ventromedial nucleus （VMH） in male mice. Methods Mice were divided into two groups： control group and chronic restraint stress group （4 weeks）. And the body weight and food intake （24 h） were recorded every week. The ROS generation in VMH was detected by di- hydroethidium （DHE）. The histological changes were investigated by HE staining. The expression of NOX2, p47phox and RAC1 in VMH were examined by immunohistochemistry and immunoblot analysis. The expression of PKCct in VMH was measured by immunoblot analysis. Results Compared with control group, chronic restraint stress significantly decreased the food intake and body weight, and the ROS production was significantly increased in VMH in male mice. Histology results showed that chronic restraint stress significantly induce neuronal damage in VMH. Immunohistochemical and immunoblot analysis showed that, compared with control group, the expression of PKCα, NOX2, p47phox and RAC1 were significantly increased in VMH. Conclusion Chronic restraint stress may induce the VMH neuronal damage in male mice. The mechanisms may be related to NADPH oxidase mediated ROS accumulation and oxidative damage