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Background The browning of white fat is a hot spot in metabolic disease research. Myostatin (Mstn) inhibits muscle growth, and has correlation with the growth and differentiation of adipocytes, but its effect on the browning of white fat in type 2 diabetes mellitus (T2DM) is still unclear. Objective To examine changes in expression levels of genes related to the browning of white fat following Mstn gene knockout to assess the effect of Mstn on the browning of white fat in a mouse model of T2DM. Methods This study was conducted from January 2019 to January 2020. Thirty-six male, SPF, C57BL/6N mice were selected. The 12 wild-type (WT) mice were equally randomized into WT group and WT+DM group, 12 heterozygous mice with Mstn gene knockout〔Mstn (+/-) 〕 were equally randomized into Mstn (+/-) group and Mstn (+/-) +DM group, 12 homozygous mice with Mstn gene knockout〔Mstn (-/-) 〕 were equally randomized into Mstn (-/-) group and Mstn (-/-) +DM group. The WT group, Mstn (+/-) group, Mstn (-/-) group received a normal diet, and the WT+DM group, Mstn (+/-) +DM group, Mstn (-/-) +DM group received a high-fat diet and a small dose of streptozotocin to construct T2DM models. When the intervention was finished in all groups, weight, body length, white fat and brown fat mass, and serum lipids〔triacylglycerol (TG) , total cholesterol (TC) , low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) measured using automatic biochemical analyzer, and free fatty acid (FFA) measured using ELISA〕 were collected. The Lee's index, white-brown fat ratio and fat mass index were calculated. The morphology of white fat and brown fat cells was observed using HE staining. The relative expression levels of peroxisome proliferator-activated receptor gamma (PPAR-γ) , peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) , uncoupling protein 1 (UCP1) and cluster of differentiation 137 (CD137) protein in white and brown fat were determined by Western-blotting. Results Mstn (-/-) group had lower Lee's index, white-brown fat ratio and levels of serum TG and TC compared with WT group (P |
