慢性束缚应激诱导脂肪Nox-4表达及其在脂肪炎症发生中的作用

The role of chronic restrain stress induced Nox-4 expression and its significances in adipose inflammation

目的探讨慢性束缚应激诱导脂肪组织NADPH氧化酶4(Nox-4)表达及其在脂肪炎症发生中的作用。方法雄性SPF级20只昆明小鼠随机分2组(每组10只),即束缚应激组和正常对照组。束缚应激小鼠每天在自制式束缚器中限制活动2h,持续14天。采用HE染色、免疫组化、RT-PCR及ELISA等试验方法检测脂肪组织和血液中Nox-4,巨噬细胞表面标志物(CD11b、CD68、F4/80),抗氧化蛋白(Mn-SOD、GSH-Px、Catalase),脂肪细胞因子(脂联素、MCP-1、IL-6、TNF-α)等指标的表达。结果应激小鼠腹股沟脂肪垫白色脂肪组织(WAT)与对照组相比显著缩小。应激组WAT出现大量的单核细胞、中性粒细胞浸润反应和炎症性改变。应激组WAT组织中CD11b阳性细胞的比例及F4/80、CD68的mRNA表达水平显著升高。应激组FFA释放的浓度显著增高,约对照组的2倍(P<0.01)。Nox-4主要表达于脂肪细胞中,应激组Nox-4的mRNA表达和血清浓度显著高于对照组(P<0.01);应激组WAT组织中脂联素的mRNA表达与对照组相比显著降低(P<0.01);应激组WAT组织中MCP-1、IL-6及TNF-α的mRNA表达与对照组相比显著增高(P<0.01)。结论心理应激导致脂肪氧化、抗氧化系统破坏,使得脂肪细胞因子表达异常,进而引起脂肪组织炎症。

Objective To investigate stress induced Nox-4 expression and to explore its role in adipose inflammation. Methods Twenty male Kunming mice were randomly divided into two groups (n=10 each), chronic restraint stress group and control group. Stress mice were restrained in self-made restraint device for 2 hours per day for 14 days. HE staining, immunohistochemistry, RT-PCR, and ELISA were used to analyze the expression of Nox-4, CD11b, antioxidant protein (Mn SOD, GSH-Px, Catalase), adipocytokines (adiponectin, MCP-1, IL-6, TNF-a). Results White adipose tissue (WAT) of stress mice inguinal fat pad significantly shrank compared to control group. HE staining showed that there were a large number of mononuclear cells, neutrophils, eosinophils, and cell infiltration reactions and inflammatory changes in WAT of stress mice. The stress significantly increased CD11b-positive cells and the expression of mF4/80, CD68. The concentration of serum FFA in stress group increased significantly, nearly twice of the control group (P<0.01). Nox-4 positive staining cells in stress WAT were deeper and more abundant. The level of Nox-4 in stress WAT was significantly higher than that of control group(P<0.01). The levels of antioxidant proteins such as Mn-SOD, GSH-Px, and catalase in stress WAT were significantly lower than those of control group (P<0.01). The expression levels of adiponectin in stress WAT were significantly reduced as compared to control group (P<0.01). The levels of MCP-1, IL-6 and TNF-α in stress WAT were significantly higher than those in control group (P<0.01). Conclusion Stress may lead to imbalance of adipose oxidation/antioxidant system and abnormal expression of adipocytokines, which may result in adipose inflammation.