miR-1934, downregulated in obesity, protects against low-grade inflammation in adipocytes

It has been previously demonstrated that miR-1934 was specially regulated by adiponectin, an anti-inflammatory adipokine, in adipose tissue (AT) in vivo. Herein we investigated the role of miR1934 in the regulation of inflammatory response. Compared with chow-diet fed mice, miR1934 expression was down-regulated in epididymal AT of high-fat diet-induced obese mice. miR1934 expression was down-regulated as well in omental AT of obese subjects in comparison with lean subjects. The circulating miR-1934 was also lower in obese subjects and its levels were correlated negatively with body mass index (BMI), waist circumference (WC), low-density lipoprotein cholesterol (LDL-c), insulin resistance and high-sensitivity C-reactive protein (hs-CRP). The down-regulation of miR1934 in obesity was mimicked by TNF-α treatment of 3T3-L1 adipocytes. Moreover, overexpression of miR1934 suppressed the TNF-α-induced gene expression of interleukin-6 (IL-6) and monocyte chemotactic protein-1 (MCP-1) in 3T3-L1 adipocytes. De novo formed AT in nude mice transplanted with 3T3-L1 preadipocytes overexpressing miR1934 displayed a reduction in IL-6, TNF-α, IL-1β and an enhancement in IL-10 gene expression when compared with transplant with 3T3-L1 preadipocytes overexpressing miR1934 scrambled control sequence. These results suggest that miR1934 is an important anti-inflammatory factor and may represent a novel mechanism for controlling AT inflammation.