Gîză D E, Vasilescu C
UMF Carol Davila, Bucureşti.
Chirurgia (Bucur). 2010 Sep-Oct;105(5):625-30.
MicroRNAs are non-coding RNA fragments, well characterized and well preserved along the evolution of the species and whose essential role is to regulate gene expression. MicroRNAs perform its action on messenger RNA ("target"). They induce degradation or repression of target translation with a significant decrease in the quantity and the activity of proteins. MicroRNAs are involved in normal cell function. Abnormal levels of microRNA were found in several pathological contiditions such as cancer, autoimmune diseases, viral infections, sepsis. Sepsis appears as a result of an improper inflammatory response after systemic bacterial infection. It remains a disease with a high incidence and mortality despite the evolution of diagnostic and treatment techniques. Sepsis patients have similar features to those found in the endotoxin tolerance phenomenon. Endotoxin tolerance is a state of hyporesponsivness to endotoxin challenge induced by a prior exposure. Due to its important role in repression of the pro-inflammatory cytokines translation, microRNA can be considered a new mechanism of endotoxin tolerance and a new mechanism involved in sepsis pathogenesis. In sepsis patients abnormal levels of the following types of microRNA were found: miR-146, miR-155, miR150, miR-132. Further studies are carried out to demonstrate the potential role of microRNA as biomarkers in sepsis.
微小RNA是非编码RNA片段，在物种进化过程中特征明确且保存良好，其重要作用是调节基因表达。微小RNA作用于信使RNA（“靶标”）。它们诱导靶标翻译的降解或抑制，导致蛋白质数量和活性显著下降。微小RNA参与正常细胞功能。在多种病理状况下，如癌症、自身免疫性疾病、病毒感染、脓毒症，发现了微小RNA水平异常。脓毒症是全身细菌感染后不适当的炎症反应所致。尽管诊断和治疗技术有所发展，但它仍然是一种发病率和死亡率都很高的疾病。脓毒症患者具有与内毒素耐受现象中发现的特征相似的特点。内毒素耐受是一种因先前暴露而对内毒素刺激反应低下的状态。由于微小RNA在抑制促炎细胞因子翻译方面的重要作用，它可被视为内毒素耐受的一种新机制以及脓毒症发病机制中的一种新机制。在脓毒症患者中发现了以下几种微小RNA水平异常：miR-146、miR-155、miR150、miR-132。正在进行进一步研究以证明微小RNA作为脓毒症生物标志物的潜在作用。
