MiR-540 as a novel adipogenic inhibitor impairs adipogenesis via suppression of PPARγ.

A better understanding of the molecular mechanisms in adipogenesis may provide new insights into adipose tissue-related diseases. Recently, microRNAs (miRNAs) have emerged as a class of epigenetic regulators of stem cell differentiation. In this study, we found that miR-540 was an essential negative regulator of adipogenic differentiation in adipose tissue-derived stromal cells (ADSCs). Lentivirus-mediated overexpression of miR-540 resulted in blockade of the expression of C/EBP-α and PPARγ, the two master transcription factors of adipogenesis, and deficient lipid accumulation, whereas inhibition of miR-540 promoted these processes. Target gene reporter assays showed that miR-540 directly targeted the 3'-untranslated region (3'UTR) of PPARγ, resulting in a decrease of PPARγ protein expression. Collectively, these data suggest that miR-540 represents a new adipogenic inhibitor by, at least in part, targeting PPARγ.