【摘要】 目的：探究长期抗阻训练通过调控细胞焦亡途径而影响骨骼肌蛋白质代谢的可能机制。方法：30只8月龄SD大鼠分为3组：基础值组（N组，n=10），干预前取材；安静对照组（C组，n=10），正常饮食32周，不运动；抗阻训练组（R组，n=10），进行30%负重（自身体重）、35°坡度、跑速15 m/min的跑台训练，每次训练4组×2个循环，隔天训练一次，共32周。干预后测试大鼠体重、瘦体重、胫骨前肌（TA）湿重；HE染色观察肌纤维形态并计算肌纤维横截面积；Western blot测试肌肉合成相关蛋白哺乳动物雷帕霉素靶蛋白（mTOR）和真核翻译起始因子4E结合蛋白1(4E-BP1)，分解相关蛋白叉头状转录因子O1(FoxO1)、肌肉环状指基因1(MuRF1)、肌肉萎缩盒F基因（Atrogin1）和泛素（Ub）的表达；细胞焦亡PCR芯片筛选TA中的焦亡差异表达基因，q PCR验证芯片结果准确性；WesternBlot测试细胞焦亡关键蛋白核因子-κB(NF-κB)、接头蛋白凋亡相关斑点样蛋白（ASC）、消皮素D(GSDMD)和天冬氨酸蛋白水解酶1(Caspase1/Casp1)的表达。结果：（1）C组大鼠体重显著高于N组，R组显著低于C组；C组瘦体重及其百分含量显著低于N组，R组显著高于C组（P<0.05）。（2）C组肌纤维横截面积较N组显著降低，R组较C组显著增加（P<0.05）。（3）C组磷酸化4E-BP1(p-4E-BP1)蛋白含量和p-4E-BP1/4E-BP1比值显著低于N组，R组p-4EBP1蛋白含量显著高于C组（P<0.05）;C组FoxO1和Ub蛋白含量显著高于N组，R组显著低于C组，C组pFoxO1/FoxO1比值显著低于N组，R组显著高于C组（P<0.05）。（4）焦亡PCR芯片结果显示，R组较C组下调的焦亡基因数目增加。对C/N组上调的差异基因Asc,C/N组上调且在R/C组下调的差异基因核苷酸结合寡聚化结构域样受体家族凋亡抑制蛋白6(Naip6)和R/C组下调的差异基因Casp1进行qPCR验证，与芯片结果一致。（5）C组NF-κB和ASC蛋白含量显著高于N组，R组Caspase1蛋白含量显著低于N组（P<0.05）。结论：长期抗阻训练通过降低骨骼肌蛋白质分解而缓解增龄性肌萎缩的发展，抑制细胞焦亡可能是其机制之一。更多还原

【Abstract】 Objective To explore the possible mechanism of long-time resistance training affecting skeletal muscle protein metabolism by regulating pyroptosis. Methods Thirty Sprague-Dawley rats were randomly divided into a baseline value group(group N),whose samples were collected before the intervention,a control group(group C) and a resistance training group(group R),each of 10. Group R underwent running with 30% weight-bearing on the slope of 35 ° and at the speed of 15 m/min,4 sets× 2 cycles for each training,once every other day,for 32 weeks,while group C did not exercise. After the intervention,the body weight,lean body mass and tibialis anterior(TA) wet weight were measured and hematoxylin-eosin staining was conducted to observe the morphology of muscle fibers,and the fibers’ cross-sectional area(FCSA) was calculated. The expression of muscle synthesis-related proteins mammalian target of rapamycin(mTOR) and eukaryotic translation initiation factor 4E-bingding protein 1(4E-BP1),decomposition-related proteins forkhead transcription factor O1(FoxO1),muscle ring finger 1(MuRF1),muscle atrophy F-box(MAFbx/Atrogin1),and ubiquitin(Ub) were tested by Western blotting. The differentially expressed genes of pyroptosis of TA were screened by PCR array,and the accuracy of the array results were verified by q PCR. The expression of pyroptosis key proteins nuclear factor kappa-B(NF-κB),apoptosis speck-like protein containing a caspase recruitment domain(ASC), Gasdermin D(GSDMD) and Caspase1(Casp1) were tested by Western blotting. Results(1)The body weight of group C was significantly higher than group N,and that of group R was significantly lower than group C. Moreover,the lean body mass and its percentage of group C were significantly lower than group N,and those of group R were significantly higher than group C(P<0.05).(2)The FCSA of group C was significantly lower than group N,and that of group R was significantly higher than group C(P<0.05).(3) The protein content of phospho-4E-BP1(p-4E-BP1) and the ratio of p-4E-BP1/4E-BP1 of group C were significantly lower than group N,and those of group R were significantly higher than group C(P<0.05). The protein content of FoxO1 and Ub of group C were significantly higher than group N,while those of group R were significantly lower than group C. The ratio of p-FoxO1/FoxO1 in group C was significantly lower than N group,and that of group R was significantly higher than group C(P<0.05).(4) The results of pyroptosis PCR array showed that the number of down-regulated pyroptotic genes increased in group R compared with group C. The up-regulated differential gene Asc in group C/N,the differential gene NOD-like receptor family,apoptosis inhibitory protein 6(Naip6) up-regulated in group C/N and down-regulated in group R/C,and the down-regulated differential gene Casp1 in group R/C were verified by qPCR,which were consistent with the array results.(5) The protein contents of NF-κB and ASC in group C were significantly higher than group N,and those of Caspase1 in group R were significantly lower than group N(P<0.05). Conclusion Long-time resistance training can alleviate the development of age-related muscular atrophy by inhibiting the breakdown of skeletal muscle proteins,and inhibiting pyroptosis may be one of its mechanism.更多还原