内毒素血症大鼠心肌组织miRNA差异表达

Differential expression of mi RNAs in myocardial tissues of rats with lipopolysaccharide- induced endotoxemia

目的分析内毒素又称脂多糖(lipopolysaccharide,LPS)血症大鼠心肌组织mi RNA表达谱变化,探讨mi RNA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。mi RNA芯片筛选心肌组织中差异表达的mi RNA,Real-time PCR验证候选mi RNA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mi R-194-3p,mi R-344a-3p,mi R-465-3p,mi R-501-5p,mi R-3596c,mi R-185-3p,mi R-877显著上调,mi R-208b-3p,mi R-547-3p,mi R-141-3p,mi R-28-5p,mi R-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mi RNA可能与其心肌损伤发生有关。

Objective To analyze the differential mi RNA expression profile in the myocardium of rats with lipopolysaccharide（LPS）- induced endotoxemia and explore the role of mi RNA 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- α and IL- 1β using real- time PCR and for observing myocardial ultrastructures under transmission electron microscopy. The differentially expressed mi RNA in the myocardium were detected using a mi RNA array, and the common differentially expressed mi RNAs were selected for verifying their actual expressions using real-time PCR. Results TLR4, TNF-α and IL-1β were over-activated in the myocardium of LPS- treated rats, in which mitochondria swelling, structural damaged and cytoplasmic vacuoles were observed. In LPSchallenged rats, mi R- 194- 3p, mi R- 344a- 3p, mi R- 465- 3p, mi R- 501- 5p, mi R- 3596 c, mi R- 185- 3p, and mi R- 877 were found upregulated significantly, whereas mi R-208b-3p, mi R-547-3p, mi R-141-3p, mi R-28-5p, and mi R-3585-5p down-regulated in the myocardium. Conclusion Significant differential expression of the mi RNAs occurs in the myocardium of LPS- treated rats,suggesting their involvement in endotoxin-induced myocardial injury.