Differential Gene Expression During Adipogenesis in Cultured Bovine Adipocytes

Abstract

Gene expression during adipogenesis was studied using Real time PCR in cultured intramuscular and subcutaneous bovine adipocytes. The study was conducted to understand expression changes in, Fatty acid binding protein 4(FABP4),Fatty acid translocase( CD36), Epithelial membrane protein(EMP3),Phosphoenol pyruvate carboxykinase 2( PEPCK2),Caveolin 1( CAV1) and Phosphatidic acid phosphatase(PPAP2B) during intramuscular (i.m) and subcutaneous(s.c) adipogenesis. The study consisted of 3 biological replicates and the differential gene expression was studied at 12 hr., 48 hr., 72 hr. and 8 days post induction. The gene expression study was done using real time PCR analysis using ribosomal 18s gene to normalize all genes and changes in gene expression was presented as fold change from the expression at control time point i.e. 0 hr. post induction. FABP4, CD36, EMP3 and PEPCK2 showed a similar expression pattern in both adipocytes. However the amount of expression was very low in i.m adipocytes for the genes compared to s.c adipocytes. This can be attributed to lower differentiation of i.m preadipocytes. CAV1 and PPAP2B were differently expressed in the two adipocytes. CAV1 sharply down regulated in i.m adipocytes on 8 days post induction, and PPAP2B showed down regulation in i.m adipocytes from 12 hr. post induction while both the genes were upregulated in s.c adipocytes. From our finding that CAV1 which plays a role in lipid storage and PPAP2B which plays a role in triglyceride synthesis were down regulated in i.m adipocytes but other adipogenic genes are expressed similarly to s.c adipocytes we can conclude that the cause of less accumulation of fat in intramuscular depot might not only due to lesser adipogenesis but also to decreased ability of i.m adipocytes to synthesize and store lipids.