紫檀芪改善睡眠限制小鼠运动耐力的作用及其机制

Pterostilbene improves exercise intolerance induced by sleep restriction in mice by activating AMPK/SIRT1 signaling and promoting mitochondrial biosynthesis

目的探讨紫檀芪(pterostilbene,PTE)对睡眠限制(sleep restriction,SR)小鼠运动耐力的改善作用及机制。方法 30只C57BL/6J雄性小鼠,分为对照组(CON)、睡眠限制组(SR)和紫檀芪干预睡眠限制组(SR+PTE)。采用睡眠剥夺仪建立SR模型,限制每日睡眠时间为4 h、持续5 d,PTE于每日8:00灌胃[100 mg/(kg·d)]。检测小鼠体质量;于观察终点进行负重力竭游泳实验,检测血清运动性疲劳生化指标;HE染色观察骨骼肌组织病理学变化。分别采用实时定量PCR和Western blot检测骨骼肌线粒体DNA(mtDNA)含量,线粒体生物合成相关基因的mRNA、蛋白表达,以及腺苷酸活化蛋白激酶[adenosine 5’-monophosphate (AMP)-activated protein kinase,AMPK]和沉默信息调节因子1(silent mating-type information regulation 2 homolog 1,SIRT1)的蛋白表达。结果与CON组相比,SR组和SR+PTE组小鼠体质量均显著下降(P<0.05),但SR组下降幅度更大(P<0.05);SR+PTE组小鼠较SR组力竭游泳时间显著延长(P<0.05),血清LDH、CK水平显著下降(P<0.05);HE染色结果差异无统计学意义。SR+PTE组小鼠骨骼肌组织mtDNA含量及PGC1α、NRF1、ERRα和TFAM等线粒体生物合成相关基因的表达较SR组明显升高(P<0.05)。Western blot检测结果显示:SR+PTE组小鼠p-AMPK和SIRT1表达较SR组明显升高(P<0.05),AMPK表达差异无统计学意义。结论紫檀芪可改善睡眠限制小鼠的运动耐力,其机制可能通过激活AMPK/SIRT1信号通路提高线粒体生物合成能力。

Objective To investigate the effect of pterostilbene(PTE) on exercise intolerance induced by sleep restriction(SR) in mice and explore the underlying mechanism. Methods Thirty male C57BL/6 J mice were randomized into control group, SR group and SR with PTE treatment(SR+PTE) group. The mice in the latter 2 groups were kept awake using a sleep deprivation apparatus with their daily sleep time limited to 4 h for 5 consecutive days. In SR+PTE group, the mice received PTE treatment by gavage at a daily dose of 100 mg/kg(administered at 08:00 am). After the 5-day treatment, body weight changes of the mice were recorded, and a weight-loaded forced swimming test was performed;blood samples were collected for detecting serum levels of biochemical indicators of exercise fatigue. HE staining was used to observe the pathological changes of the skeletal muscle tissue. The mitochondrial DNA(mtDNA) content and the expressions of AMPK, SIRT1 and mitochondrial biogenesis-related genes were determined by real-time PCR and Western blotting. Results Compared with those in the control group, the mice in both SR and SR+PTE groups showed significant weight loss after the treatment(P<0.05), and the decrease was more obvious in SR group(P<0.05). Compared with those in SR group, the mice in SR+PTE group had significantly prolonged exhaustive swimming time and significantly lowered serum levels of LDH and CK(P<0.05). No significant differences were found in skeletal muscle pathologies among the groups. The mtDNA content and expression levels of mitochondrial biosynthesis-related genes including PGC1α, NRF1, ERRα and TFAM were significantly higher in SR+PTE group than in SR group(P<0.05). Western blotting showed that the expression levels of p-AMPK and SIRT1 were significantly higher in SR+PTE group than in SR group(P<0.05), while that of AMPK were comparable between the 2 groups. Conclusion PTE can improve exercise intolerance in mice exposed to SR possibly by activating AMPK/SIRT1 signaling pathway to enhance mitochondrial biogenesis.