Trim33 promotes lipid accumulation and expressions of adipocyte-specific genes in bone marrow stromal cells / 医学研究生学报

ABSTRACT

ObjectiveTripartite motif 33 (Trim33) is known to play a very important part in regulating osteoblast differentiation, but its role in adipocyte differentiation is rarely reported. The aim of this study was to investigate the regulatory effect of Trim33 on adipocyte differentiation.MethodsBone marrow stromal cell ST2 cells transfected with the Trim33-pcDNA3.1 plasmid were included in the experimental group and those transfected with the pcDNA3.1 plasmid taken as the control. The cells of both groups were treated with adipogenic medium to induce adipocyte differentiation, followed by determination of the expressions of the adipocyte-specific genes CCAAT enhancer binding protein alpha (C/EBPα), peroxisome proliferator-activated receptor gamma (PPARγ), adipocyte characterizing factor FABP4, and adipocytokines adipsin by oil red O staining, qRT-PCR and Western blotting.ResultsThe expression of Trim33 was significantly upregulated in the experimental group as compared with that in the control (88.51±14.31 vs 1.00±0.31, P<0.01). After 5 days of adipogenesis induction, there were dramatically more lipid droplets in the ST2 cells and the A value was markedly higher in the former than in the latter group (0.69±0.03 vs 0.34±0.03, P<0.01). Compared with the control, the cells in the experimental group exhibited remarkable increases in the relative mRNA expressions of C/EBPα, PPARγ, FABP4 and adipsin as well as the protein expressions of Trim33, PPARγ, C/EBPα and FABP4.ConclusionTrim33 promotes lipid accumulation and upregulates the expressions of adipocyte-specific genes in bone marrow stromal cells.