Role of RNA-binding protein HuR in human adipocyte differentiation

Objective To investigate the expressions of RNA-binding protein human antigen R(HuR), fatty acid binding protein type 4(FABP4), fatty acid synthetase(FASN), and lipoprotein lipase(LPL)during the differentiation of human adipocytes, and to explore their possible roles. Methods Human adipose-derived mesenchymal stem cells were induced by adipogenic differentiation, and the adipogenesis of cells was observed by oil red O staining. The expressions of HuR, FABP4, FASN, and LPL mRNA and protein were detected by real-time PCR and Western blotting. After HuR was silenced by siRNA, the change of adipogenesis for human adipose-derived mesenchymal stem cells was observed and the expressions of adipogenic genes were detected. Results The expressions of HuR, FABP4, FASN, and LPL mRNA and protein were significantly increased after human adipose-derived mesenchymal stem cells were induced to differentiate into adipocytes(all P<0.01). After HuR expression was down-regulated by siRNA, the adipogenic level of human adipose-derived mesenchymal stem cells was reduced, with decreased protein levels of FABP4, FASN, and LPL(all P<0.05), which were without changes for their mRNA levels. Conclusion HuR promotes the differentiation of human adipocytes mainly via regulating the changes of FABP4, FASN, and LPL protein levels. (Chin J Endocrinol Metab, 2017, 33: 854-860) Key words: Adipocyte differentiation; RNA binding protein; Human antigen R; Adipocyte fatty acid binding protein; Fatty acid synthase; Lipoprotein lipase