论文部分内容阅读
目的:探讨间歇运动对大鼠骨骼肌细胞增殖和白血病抑制因子(Leukemia inhibitory factor,LIF)及其下游信号分子表征的影响。方法:3月龄雄性SD大鼠,随机分为安静对照组(C)、间歇运动组(CE),每组15只。运动组采用小动物跑台运动,运动方式为先以10 m/min×10 min,再以25 m/min×7 min和15m/min×3 min,依次交替,60 min/d,5 d/周×8周。运动结束后次日,分离切取大鼠腓肠肌组织,称重。组织学方法测定腓肠肌细胞横截面积(cross-section area,CSA);Western blot检测腓肠肌LIF及其受体(Leukemia inhibitory factor receptor,LIFR)、信号转导与转录激活因子(signal transducer and activator of transcription,STAT3)及其磷酸化水平(p-STAT3)和增殖细胞核抗原(proliferating cell nuclear antigen,PCNA)蛋白表达;免疫荧光化学观察分析腓肠肌LIF、LIFR、PCNA和细胞增殖抗原标记物(ki67)表达;RT-q PCR检测腓肠肌LIF/LIFR mRNA水平。结果:与C组比较,CE组大鼠腓肠肌重量和细胞CSA增大(P<0.01),LIF/LIFR基因和蛋白表达均显著增加(P<0.01,P<0.05),STAT3磷酸化水平显著升高(P<0.01),PCNA和ki67蛋白表达显著增加(P<0.01)。结论:8周间歇运动可促进正常大鼠骨骼肌细胞肥大,激活LIF-LIFR-STAT3信号通路,诱导骨骼肌细胞增殖。
Objective: To investigate the effects of intermittent exercise on the proliferation of skeletal muscle cells and the expression of leukemia inhibitory factor (LIF) and its downstream signaling molecules. Methods: Three-month-old male Sprague-Dawley rats were randomly divided into 5 groups: quiet control group (C) and intermittent exercise group (CE). In the exercise group, the running speed of small animals was increased by 10 m / min × 10 min, then by 25 m / min × 7 min and 15 m / min × 3 min, followed by 60 min / d, 5 d / Week × 8 weeks. The next day after exercise, rat gastrocnemius tissue was isolated and weighed. The cross-section area (CSA) of gastrocnemius muscle cells was determined by histological method. The expression of LIF and LIFR, signal transducer and activator of transcription , STAT3, p-STAT3 and proliferating cell nuclear antigen (PCNA) were detected by immunofluorescence staining. Expression of LIF, LIFR, PCNA and ki67 in gastrocnemius muscle were detected by immunofluorescence staining. The mRNA expression of LIF / LIFR in gastrocnemius muscle was detected by RT-q PCR. Results: Compared with group C, the gastrocnemius muscle weight and cell CSA in CE group increased (P <0.01), the gene and protein expression of LIF / LIFR increased significantly (P <0.01, P <0.05) and the phosphorylation level of STAT3 increased significantly (P <0.01), the expression of PCNA and ki67 protein increased significantly (P <0.01). Conclusion: Intermittent exercise for 8 weeks can promote normal rat skeletal muscle cell hypertrophy, activate LIF-LIFR-STAT3 signaling pathway and induce skeletal muscle cell proliferation.