Feng Yue Ying, Xu Xiao Qin, Ji Chen Bo, Shi Chun Mei, Guo Xi Rong, Fu Jun Fen
Department of Endocrinology, the Children's Hospital of Zhejiang University School of Medicine, Hangzhou, China.
Cell Physiol Biochem. 2014;34(6):1983-97. doi: 10.1159/000366394. Epub 2014 Nov 26.
BACKGROUND/AIM: Emerging evidence suggests that microRNA (miRNA) mediated gene regulation influences the maintenance of metabolic homeostasis, particularly the states of obesity and insulin resistance, thereby providing a potential link between miRNAs and nonalcoholic fatty liver disease (NAFLD).
Sprague-Dawley rats fed a high-fat diet (HFD) were used to establish a rat model of NAFLD. The miRNA expression profile of liver tissues was evaluated using Illumina HiSeq deep sequencing. Selected miRNAs were then validated by real-time PCR at both 4- and 12-week time points. Furthermore, the expression levels of these miRNAs were assessed in HepG2 cells and human hepatocytes treated with free fatty acids (FFAs) and proinflammatory factors (tumour necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6).
Our results showed that consumption of a HFD for 4 weeks caused simple steatosis, which progressed to steatohepatitis at 12 weeks. miRNA deep sequencing analysis identified 44 known up-regulated miRNAs (fold change >1.5) and 12 down-regulated miRNAs (fold change <0.5). Among the abnormally expressed miRNAs, miR-200a, miR-200b, miR-200c, miR-146a, miR-146b and miR-152 were up-regulated both in vitro and vivo. Interestingly, the expression levels of these six miRNAs were increased in HepG2 cells and human hepatocytes after treatment with FFAs and proinflammatory factors.
These findings suggest a critical role for miRNAs in the pathogenesis of NAFLD.
背景/目的：新出现的证据表明，微小RNA（miRNA）介导的基因调控影响代谢稳态的维持，尤其是肥胖和胰岛素抵抗状态，从而在miRNA与非酒精性脂肪性肝病（NAFLD）之间提供了潜在联系。
使用喂食高脂饮食（HFD）的Sprague-Dawley大鼠建立NAFLD大鼠模型。使用Illumina HiSeq深度测序评估肝组织的miRNA表达谱。然后在4周和12周时间点通过实时PCR验证所选的miRNA。此外，在经游离脂肪酸（FFA）和促炎因子（肿瘤坏死因子-α（TNF-α）和白细胞介素-6（IL-6））处理的HepG2细胞和人肝细胞中评估这些miRNA的表达水平。
我们的结果表明，食用4周HFD会导致单纯性脂肪变性，在12周时进展为脂肪性肝炎。miRNA深度测序分析鉴定出44个已知的上调miRNA（倍数变化>1.5）和12个下调miRNA（倍数变化<0.5）。在异常表达的miRNA中，miR-200a、miR-200b、miR-200c、miR-146a、miR-146b和miR-152在体外和体内均上调。有趣的是，在用FFA和促炎因子处理后，HepG2细胞和人肝细胞中这六种miRNA的表达水平升高。
这些发现表明miRNA在NAFLD发病机制中起关键作用。
