Xu Guli, Yuan Yexian, Luo Pei, Yang Jinping, Zhou Jingjing, Zhu Canjun, Jiang Qingyan, Shu Gang
Guangdong Laboratory for Lingnan Modern Agriculture and Guangdong Province Key Laboratory of Animal Nutritional Regulation, National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, China.
Front Vet Sci. 2022 Jan 14;8:808863. doi: 10.3389/fvets.2021.808863. eCollection 2021.
Endurance training and explosive strength training, with different contraction protein and energy metabolism adaptation in skeletal muscle, are both beneficial for physical function and quality of life. Our previous study found that chronic succinate feeding enhanced the endurance exercise of mice by inducing skeletal muscle fiber-type transformation. The purpose of this study is to investigate the effect of acute succinate administration on skeletal muscle explosive strength and its potential mechanism. Succinate was injected to mature mice to explore the acute effect of succinate on skeletal muscle explosive strength. And C2C12 cells were used to verify the short-term effect of succinate on oxidative phosphorylation. Then the cells interfered with succinate receptor 1 (SUCNR1) siRNA, and the SUCNR1-GKO mouse model was used for verifying the role of SUCNR1 in succinate-induced muscle metabolism and expression and explosive strength. The results showed that acute injection of succinate remarkably improved the explosive strength in mice and also decreased the ratio of nicotinamide adenine dinucleotide (NADH) to NAD and increased the mitochondrial complex enzyme activity and creatine kinase (CK) activity in skeletal muscle tissue. Similarly, treatment of C2C12 cells with succinate revealed that succinate significantly enhanced oxidative phosphorylation with increased adenosine triphosphate (ATP) content, CK, and the activities of mitochondrial complex I and complex II, but with decreased lactate content, reactive oxygen species (ROS) content, and NADH/NAD ratio. Moreover, the succinate's effects on oxidative phosphorylation were blocked in SUCNR1-KD cells and SUCNR1-KO mice. In addition, succinate-induced explosive strength was also abolished by SUCNR1 knockout. All the results indicate that acute succinate administration increases oxidative phosphorylation and skeletal muscle explosive strength in a SUCNR1-dependent manner.
耐力训练和爆发力训练对身体功能和生活质量都有益处，它们会使骨骼肌产生不同的收缩蛋白和能量代谢适应性变化。我们之前的研究发现，长期喂食琥珀酸可通过诱导骨骼肌纤维类型转变来增强小鼠的耐力运动能力。本研究旨在探讨急性给予琥珀酸对骨骼肌爆发力的影响及其潜在机制。向成年小鼠注射琥珀酸以探究其对骨骼肌爆发力的急性影响。利用C2C12细胞验证琥珀酸对氧化磷酸化的短期作用。然后用琥珀酸受体1（SUCNR1）小干扰RNA干扰细胞，并使用SUCNR1基因敲除（SUCNR1-GKO）小鼠模型来验证SUCNR1在琥珀酸诱导的肌肉代谢、表达及爆发力中的作用。结果显示，急性注射琥珀酸可显著提高小鼠的爆发力，同时降低骨骼肌组织中烟酰胺腺嘌呤二核苷酸（NADH）与NAD的比值，并增加线粒体复合酶活性和肌酸激酶（CK）活性。同样，用琥珀酸处理C2C12细胞发现，琥珀酸可显著增强氧化磷酸化，使三磷酸腺苷（ATP）含量、CK以及线粒体复合物I和复合物II的活性增加，但乳酸含量、活性氧（ROS）含量及NADH/NAD比值降低。此外，在SUCNR1基因敲低（KD）细胞和SUCNR1基因敲除小鼠中，琥珀酸对氧化磷酸化的作用被阻断。另外，SUCNR1基因敲除也消除了琥珀酸诱导的爆发力。所有结果表明，急性给予琥珀酸以SUCNR1依赖的方式增加氧化磷酸化和骨骼肌爆发力。
