Zhuhai Interventional Medical Center, Zhuhai Precision Medical Center, Zhuhai People's Hospital, Zhuhai Hospital Affiliated with Jinan University, Zhuhai, Guangdong 519000, PR China.
Department of General Surgery, Zhuhai Precision Medical Center, Zhuhai People's Hospital, Zhuhai Hospital Affilated with Jinan University, Zhuhai, Guangdong 519000, PR China.
Life Sci. 2020 Feb 1;242:117188. doi: 10.1016/j.lfs.2019.117188. Epub 2019 Dec 19.
Reactive oxygen species (ROS) bidirectionally regulate insulin sensitivity in skeletal muscle. Insulin-induced ROS generation elevates insulin-regulated metabolic effects; however, chronic oxidative stress causes severe insulin resistance in skeletal muscle. Resveratrol (RV), as a natural antioxidant, eliminates intracellular ROS. It's unclear that whether it has different roles in insulin signaling pathway in skeletal muscle.
C57BL/6J mice and C2C12 myotubes were used to assess metabolic regulation effects of RV. Protein activation was detected using Immunofluorescence and Western Blot analysis. ROS were analyzed using confocal microscope and flow cytometry sorting (FACS). Intracellular reducing molecules were detected using an enzymatic method. Glucose uptake was measured using a fluorescent deoxyglucose analog (2-NBDG).
We found that RV attenuated insulin-stimulated AKT phosphorylation via elimination of insulin-induced ROS generation in skeletal muscle, suggesting that RV decreased activation of the insulin-induced AKT signaling. In skeletal muscle of insulin resistance, RV reduced oxidative stress, restored intracellular glutathione (GSH) level, and enhanced insulin-induced AKT activation and glucose absorption. These results suggested that RV ameliorated insulin resistance by change of redox levels in skeletal muscle.
This study revealed bidirectional regulation effects of RV on insulin-stimulated metabolism in skeletal muscle through alternation of intracellular redox homeostasis, which might provide a guidance role for treatment of metabolic diseases.
活性氧（ROS）在骨骼肌中双向调节胰岛素敏感性。胰岛素诱导的 ROS 生成可提高胰岛素调节的代谢效应；然而，慢性氧化应激会导致骨骼肌严重的胰岛素抵抗。白藜芦醇（RV）作为一种天然抗氧化剂，可消除细胞内的 ROS。但尚不清楚其在骨骼肌胰岛素信号通路中是否具有不同的作用。
使用 C57BL/6J 小鼠和 C2C12 肌管来评估 RV 的代谢调节作用。使用免疫荧光和 Western Blot 分析检测蛋白激活情况。使用共聚焦显微镜和流式细胞术分选（FACS）分析 ROS。使用酶法检测细胞内还原分子。使用荧光脱氧葡萄糖类似物（2-NBDG）测量葡萄糖摄取。
我们发现 RV 通过消除骨骼肌中胰岛素诱导的 ROS 生成来减弱胰岛素刺激的 AKT 磷酸化，表明 RV 降低了胰岛素诱导的 AKT 信号的激活。在胰岛素抵抗的骨骼肌中，RV 降低了氧化应激，恢复了细胞内谷胱甘肽（GSH）水平，并增强了胰岛素诱导的 AKT 激活和葡萄糖吸收。这些结果表明，RV 通过改变骨骼肌中的氧化还原水平来改善胰岛素抵抗。
本研究通过改变细胞内氧化还原稳态，揭示了 RV 对骨骼肌中胰岛素刺激代谢的双向调节作用，这可能为代谢性疾病的治疗提供指导作用。
