热预适应延缓运动疲劳的分子机制的初步探究

Preliminary Exploration on the Molecular Mechanism of Thermal Preconditioning for Delaying Exercise Fatigue

目的:为了探究热预适应延缓运动疲劳现象的机制,对成年雄性SD大鼠肌肉组织经热预适应后进行转录组测序,并利用生物信息学方法进行分析,寻找与之相关的基因及信号通路。方法:选取成年雄性SD大鼠,随机分为对照组与热预适应组,对照组室温安静饲养,热预适应组进行热预适应处理,处理条件为每日42℃热处理15 min,每隔30 min重复1次,每日3次且连续处理7天。处理结束后,提取两组大鼠肌肉组织RNA,使用BGISEQ-500平台对基因表达情况进行高通量测序。结果:样品测序片段比对基因组的平均比率为92.53%,比对到基因的平均比率为84.26%。经测序得到的17 951个基因中,已知基因为17 616个,预测的新基因为435个;同时,测序得到的9 825个新转录本中,有8 325个属于已知蛋白编码基因新的可变剪接亚型,435个属于新的蛋白编码基因转录本,剩下的1 065个属于长链非编码RNA。在热预适应后的肌肉组织中,共获得2 267个差异表达基因,其中上调基因1 712个,下调基因555个。结论:高通量转录组测序技术提供了样品中全部转录本信息,获得了在肌肉细胞增殖分化过程中具有重要功能的基因,其中上调基因在肌肉运动疲劳代谢通路中有着重要作用,推测这可能是由于大鼠经热预适应处理后会激活某些基因编码信号通路的因子,并启用这些信号通路延缓疲劳并延长运动时间。

Objective: To explore the mechanism of thermal preconditioning delaying the exercise fatigue, the transcriptome of muscle tissue of adult male SD rats was sequenced before and after thermal preconditioning, and analyzed by bioinformatics methods to find the related genes and signal pathways. Methods: Adult male SD rats were randomly divided into control group and thermal preconditioning group. The control group was fed quietly at room temperature, and the thermal preconditioning group was treated with thermal preconditioning, the condition of thermal preconditioning is to heat treat at 42 ℃ for 15 min every day, repeat every 30 min, three times a day and treat continuously for 7 days. After the treatment, RNA was extracted from the muscle tissue of two groups of rats, and the gene expression was sequenced by BGISEQ-500platform. Results: The average ratio of sequencing fragments to genome was 92.53%, and the average comparison rate of gene sets was 84.26%. Among the 17 951 genes obtained by sequencing, 17 616 were known genes and 435 new genes were predicted. Meanwhile, among the 9 825 new transcripts detected, 8 325 were new alternative splicing subtypes of known proteincoding genes, 435 were transcripts of new protein-coding genes, and the remaining 1 065 were long-chain non-coding RNAs. A total of 2 267 differentially expressed genes were obtained in muscle tissues after thermal preconditioning. of which 1 712 genes were up-regulated and 555genes were down-regulated. Conclusions: High throughput RNA SEQ provides all transcript information in the sample and obtains genes with important functions in the process of muscle cell proliferation and differentiation. Among them, up-regulated genes play an important role in the metabolic pathway of muscle exercise fatigue,It is speculated that this may be due to the fact that after thermal preconditioning, rats will stimulate some factors encoding signal pathways,and enable these signal pathways to delay fatigue and prolong exercise time.