Sharma Neeraj K, Varma Vijayalakshmi, Ma Lijun, Hasstedt Sandra J, Das Swapan K
Section on Endocrinology and Metabolism, Department of Internal Medicine Wake Forest School of Medicine, Medical Center Boulevard, NRC Building#E159 Winston-Salem, North Carolina 27157, USA.
Microrna. 2015;4(3):194-204. doi: 10.2174/2211536604666151103121817.
Micro RNAs (miRNAs) are a class of non-coding regulatory RNAs. We performed a transcriptome-wide analysis of subcutaneous adipose tissue and in vitro studies to identify miRNAs and co-regulated target transcripts associated with insulin sensitivity (SI) and obesity in human.
We selected 20 insulin-resistant (IR, SI=2.0±0.7) and 20 insulin-sensitive (IS, SI=7.2±2.3) subjects from a cohort of 117 metabolically characterized non-diabetic Caucasians for comparison.
After global profiling, 3 miRNAs had marginally different expressions between IR and IS subjects. A total of 14 miRNAs were significantly correlated with %fat mass, body mass index (BMI), or SI. The qRT-PCR validated the correlation of miR-148a-3p with BMI (r=-0.70, P=2.73X10(-6)). MiRNA target filtering analysis identified DNA methyltransferase 1 (DNMT1) as one of the target genes of miR-148a-3p. DNMT1 expression in adipose tissue was positively correlated with BMI (r=0.47, p=8.42X10(-7)) and was inversely correlated with miR-148a-3p (r=-0.34). Differentiation of SGBS preadipocytes showed up-regulation of miR-148a-3p and down-regulation of DNMT1 in differentiated adipocytes. After transfecting miR-148a-3p mimics into HeLa-S3 cells, DNMT1 was down-regulated, while transfection of adipose stem cells with miR-148a-3p inhibitor up-regulated DNMT1.
Our results indicate that miR-148a-3pmediated regulation of DNMT1 expression may play a mechanistic role in obesity.
微小RNA（miRNA）是一类非编码调节性RNA。我们对皮下脂肪组织进行了全转录组分析，并开展了体外研究，以鉴定与人类胰岛素敏感性（SI）和肥胖相关的miRNA及其共同调节的靶转录本。
我们从117名经代谢特征分析的非糖尿病白种人队列中选取了20名胰岛素抵抗（IR，SI = 2.0±0.7）和20名胰岛素敏感（IS，SI = 7.2±2.3）的受试者进行比较。
经过全面分析，3种miRNA在IR和IS受试者之间的表达略有差异。共有14种miRNA与体脂百分比、体重指数（BMI）或SI显著相关。qRT-PCR验证了miR-148a-3p与BMI的相关性（r = -0.70，P = 2.73×10^(-6)）。miRNA靶标筛选分析确定DNA甲基转移酶1（DNMT1）是miR-148a-3p的靶基因之一。脂肪组织中DNMT1的表达与BMI呈正相关（r = 0.47，p = 8.42×10^(-7)），与miR-148a-3p呈负相关（r = -0.34）。SGBS前脂肪细胞的分化显示，分化的脂肪细胞中miR-148a-3p上调，DNMT1下调。将miR-148a-3p模拟物转染到HeLa-S3细胞后，DNMT1被下调，而用miR-148a-3p抑制剂转染脂肪干细胞则上调了DNMT1。
我们的结果表明，miR-148a-3p介导的DNMT1表达调控可能在肥胖中发挥机制性作用。
