二甲双胍缓解小鼠肌肉衰老的代谢组学研究

A Metabolomic Study of Metformin in Alleviating Muscle Aging in Mice

目的探究二甲双胍缓解小鼠肌肉衰老的机制。方法2月龄雄性BALB/c小鼠随机分成对照组、衰老模型组和二甲双胍组,每组10只。用125 mg·kg^(-1)D-半乳糖(D-galactose,D-gal)皮下注射8周诱导衰老小鼠模型。比色法测定小鼠血清和肌肉上清中过氧化氢酶(catalase,CAT)、谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)、总超氧化物歧化酶(superoxide dismutase,SOD)和丙二醛(malondialdehyde,MDA)的含量。高效液相色谱串联电喷雾质谱(LC-ESI-MS/MS)广靶代谢组学方法研究二甲双胍对衰老小鼠腓肠肌代谢物的影响。结果二甲双胍对衰老小鼠的体质量和采食量没有影响。四肢悬垂试验显示二甲双胍显著增加了衰老小鼠肌肉力量(P<0.01)。二甲双胍显著增加了血清和肌肉上清中的SOD和GSH-Px水平(P<0.01),显著降低了血清和肌肉上清中的MDA含量(P<0.01)。通过代谢组学测定发现,衰老小鼠腓肠肌中5种差异代谢物丙氨酸-异亮氨酸(Ala-Ile)、异亮氨酸-谷氨酸(Ile-Glu)、亮氨酸-脯氨酸-酪氨酸(Leu-Pro-Tyr)、吡啶-3,4-二羧酸(pyridine-3,4-dicarboxylic acid)和15(R)-前列腺素E1[15(R)-prostaglandin E1]在二甲双胍的作用下恢复到与对照组相同的水平。结论二甲双胍可能通过调节肌肉小肽和前列腺素水平、发挥抗氧化和抗炎特性缓解小鼠肌肉衰老。

OBJECTIVE To investigate the mechanism of metformin to alleviate muscle aging in mice.METHODS Two-month-old male BALB/c mice were randomly divided into control group,senescence model group and metformin group,with 10 mice in each group.The aging mouse model was induced by subcutaneous injection of 125 mg·kg^(-1) D-galactose(D-gal)for 8 weeks.The levels of CAT,GSH-Px,SOD and MDA in serum and muscle supernatant were measured colorimetrically.LC-ESI-MS/MS broad-target metabolomics was used to study the effects of metformin on metabolites in the gastrocnemius muscle of aging mice.RESULTS Metformin had no effect on body weight and food intake of aging mice.The limb draping test showed that metformin significantly increased muscle strength in aging mice(P<0.01).Metformin significantly increased SOD and GSH-Px levels in serum and muscle supernatants(P<0.01)and significantly decreased MDA levels in serum and muscle supernatants(P<0.01).Five differential metabolites,Ala-Ile,Ile-Glu and Leu-Pro-Tyr,pyridine-3,4-dicarboxylic acid and 15(R)-prostaglandin E1 were found to be restored to the same levels as controls in the gastrocnemius muscle of aging mice by metabolomic analysis.CONCLUSION Metformin may alleviate muscle aging in mice by modulating muscle small peptide and prostaglandin levels and exerting antioxidant and anti-inflammatory properties.