Rno-miR-130b Attenuates Lipid Accumulation Through Promoting Apoptosis and Inhibiting Differentiation in Rat Intramuscular Adipocytes.

Our previous studies have shown that miR-130b can significantly inhibit subcutaneous fat deposition in pigs. This study aims to further investigate its effect on lipid accumulation at early-stage (24 and 48 h) and late-stage (7 d) adipogenic differentiation and to clarify potential mechanisms using primary rat intramuscular preadipocytes (IMAs). Results showed that at 24 h and 48 h, miR-130b overexpression significantly reduced lipid deposition by inhibiting proliferation and inducing apoptosis. Furthermore, miR-130b overexpression significantly inhibited the expression of cell cycle and apoptosis marker genes. Specifically, the mRNA expression of Ccnd1 tended to decrease, while the BCL2 protein level was significantly decreased at 48 h. In contrast, miR-130b inhibition significantly increased the BCL2 protein level. At 7 d, the miR-130b mimic significantly decreased intracellular TG content and tended to decrease Hsd11b1 mRNA expression while significantly promoting Lpl mRNA expression. Additionally, the miR-130b mimic significantly increased the CASP3 protein level and tended to decrease the BCL2 protein level. In conclusion, our data indicated for the first time that miR-130b could reduce lipid deposition in rat IMAs through different mechanisms: at the early stage of differentiation by inhibiting proliferation and promoting apoptosis and at the late stage by inhibiting adipogenic differentiation, promoting lipid hydrolysis, and promoting apoptosis.