大鼠骨骼肌挫伤后骨骼肌肌钙蛋白I mRNA的表达变化

Expression of sTnI mRNA in Rat Skeletal Muscle after Contusion

目的应用实时荧光定量PCR技术检测大鼠骨骼肌挫伤后肌钙蛋白I mRNA(sTnI mRNA)表达情况,分析其与挫伤的关系。方法建立大鼠骨骼肌挫伤模型,分别在挫伤后0.5h,1h,6h,12h,18h取材。提取挫伤肌肉中的总RNA,逆转录合成cDNA第一条链,以cDNA作为模板,通过特异性上下游引物荧光定量PCR检测cDNA的拷贝数,选取管家基因核糖体蛋白L32为参比基因,对扩增结果进行相对定量分析。结果大鼠骨骼肌挫伤后0.5h、1h、6h、12h、18h的sTnI mRNA表达量分别为正常组的66.7%、46.6%、31.9%、18.5%和15.3%,呈时序性表达下调趋势。结论大鼠骨骼肌挫伤后0.5h内sTnI mRNA的表达即开始下调,18h内sTnI mRNA的表达有一定的时间规律性,可望作为临床诊断骨骼肌损伤的指标之一。

Objective To investigate the expression of skeletal troponin I mRNA （sTnI mRNA）changes induced by contusion in rat skeletal muscle using Real Time PCR,aimed to provide some help for forensic estimation of wound age. Methods The 36 rats were divided into two groups randomly：contusion group （5 subgroups） and control group, the contusion was performed on the right posterior limb of rat. The samples were extractd respectively at 0.5h, lh,6h, 12h, 18h after contusion. Total RNA were isolated from skeletal muscle of two groups,and reverse transcription polymerase chain reaction was conducted to synthesize the 1-st strand cDNA. With the use of sequence-specific primers,the expression level of sTnI mRNA was studied by Real Time PCR. Results Our results normalized by Ribosomal Protein L32（rpL32） showed that mRNA levels of sTnI were 66.7% ,46.6%,31.9%,18.5% and 15.3% in contusion groups compared to control group respectively at 0.5h,1h, 6h, 12h, 18h,which present down-regulated after contusion within 18hs time-orderly. Conclusion The time-order expression of sTnl mRNA after contusion was potentially indicative for diagnosis of early muscle injury.