内毒素血症大鼠心肌组织miRNA差异表达

摘要

Objective To analyze the differential miRNA expression profile in the myocardium of rats with lipopolysaccharide (LPS)-induced endotoxemia and explore the role of miRNA in endotoxin-induced myocardial injury. Methods Twenty male SD rats received intraperitoneal injection of 10 mg/kg LPS (n=10) or an equivalent amount of saline solution (n=10). At 24 h after LPS injection, the rats were sacrificed to detect myocardial expressions of TLR4, TNF-αand IL-1βusing real-time PCR and for observing myocardial ultrastructures under transmission electron microscopy. The differentially expressed miRNA in the myocardium were detected using a miRNA array, and the common differentially expressed miRNAs were selected for verifying their actual expressions using real-time PCR. Results TLR4, TNF-αand IL-1βwere over-activated in the myocardium of LPS-treated rats, in which mitochondria swelling, structural damaged and cytoplasmic vacuoles were observed. In LPS-challenged rats, miR-194-3p, miR-344a-3p, miR-465-3p, miR-501-5p, miR-3596c, miR-185-3p, and miR-877 were found up-regulated significantly, whereas miR-208b-3p, miR-547-3p, miR-141-3p, miR-28-5p, and miR-3585-5p down-regulated in the myocardium. Conclusion Significant differential expression of the miRNAs occurs in the myocardium of LPS-treated rats, suggesting their involvement in endotoxin-induced myocardial injury.%目的：分析内毒素又称脂多糖（lipopolysaccharide, LPS）血症大鼠心肌组织miRNA表达谱变化，探讨miRNA在内毒素血症心肌损伤中的作用。方法20只雄性SD大鼠随机分为对照组（n=10）和LPS组（n=10）。LPS组腹腔注射LPS 10 mg/kg，对照组腹腔注射等量生理盐水。24 h后颈脱臼处死大鼠，取心肌组织。Real-time PCR检测TLR4、TNF-α、IL-1β表达水平，透射电镜观察其超微结构变化。miRNA芯片筛选心肌组织中差异表达的miRNA，Real-time PCR验证候选miRNA实际表达水平。结果 LPS组大鼠心肌组织TLR4、TNF-α、IL-1β表达明显升高，心肌细胞发生胞质空泡，线粒体水肿、结构破坏等超微结构改变。芯片技术及Real-time PCR证实LPS组大鼠心肌组织中miR-194-3p，miR-344a-3p，miR-465-3p，miR-501-5p，miR-3596c，miR-185-3p，miR-877显著上调，miR-208b-3p，miR-547-3p，miR-141-3p，miR-28-5p，miR-3585-5p显著下调。结论内毒素血症大鼠心肌组织中发现的这些差异表达miRNA可能与其心肌损伤发生有关。