miR-130a regulates differential lipid accumulation between intramuscular and subcutaneous adipose tissues of pigs via suppressing PPARG expression.

To investigate the molecular mechanism underlying differential lipid deposition between intramuscular (IM) and subcutaneous (SC) fat tissues of pigs, peroxisome proliferator-activated receptor gamma (PPARG) expression levels were compared in these two types of adipose tissues. The results showed that both mRNA and protein levels of PPARG were significantly higher in SC fat than in IM fat. Correspondingly, the expression levels of miR-128 and miR-130a, which potentially targeting PPARG 3'-untranslated region (3'-UTR), in IM fat were 8.37 and 2.30-fold of those in SC fat respectively. Further dual luciferase activity assay showed that only miR-130a directly targeting PPARG. Moreover, over-expression of miR-130a in preadipocytes significantly inhibited its differentiation by suppressing PPARG expression. In conclusion, tissue variance of miR-130a levels results in the diverse of PPARG, and might be the reason for differential fat deposition between IM and SC fat tissues in pigs. Our study would provide the molecular foundation for IM fat deposition increase and therefore contribute to pork quality improvement.