Vitamins and Minerals
Objectives : Metabolic function of selenoprotein V (SELENOV) remains unknown, although we previously showed a strong correlation of its gene expression with the high-fat diet-induced obesity in pigs. This study was conducted to explore the role and mechanism of SELENOV in body fat metabolism.
Methods : We applied the CRISPR/Cas9 gene-targeting deletion to generate Selenov knockout (KO) mice (C57BL/6J background). Male KO and their wild-type (WT) (8 weeks old, n = 10 per genotype by treatment group) were fed a normal diet (NF, 10% calories coming from fat) or a high-fat diet (HF, 60% calories coming from fat) for 27 weeks. At the end, body weights and composition of mice were recorded, and tissues were collected to assay for gene expression and protein production related to lipid metabolism.
Results : Body weights of the KO mice fed the NF or HF diet were 16-19% higher (P < 0.05) than those of the WT mice. Total fat mass of the KO mice was 54% higher (P < 0.05) than the WT mice fed either diet, whereas total lean mass of the KO mice was 5 and 35% lower (P < 0.05) than that of WT mice fed the NF and HF diets, respectively. Gene expression of key enzymes (Fasn, Acaca, Dgat1, and Lpl) involved in lipogenesis was elevated (P < 0.05) in the white adipose tissue of the KO mice compared with the WT mice. In contrast, differences in gene expression of enzymes related to lipolysis and fatty acid oxidation (Atgl, Hsl, Ces1d, and Cpt1a) between the two genotypes were exactly the opposite (P < 0.05). Consistently, levels of proteins related to lipid accumulation (pACC, ACC, FAS, and LPL) were upregulated (P < 0.05) and proteins related to lipolysis (ATGL, HSL, and pHSL) were down-regulated (P< 0.05) in the KO mice compared with the WT mice.
Conclusions : Knockout of Selenov predisposed the male mice to elevated lipogenesis and attenuated lipolyis, leading to the body fat accumulation. This illustrated role and mechanism of SELENOV helps explain our previously-reported correlation between its gene expression and the high-fat diet-induced obesity in pigs.
Funding Sources : This research was supported in part by a NSFC grant #31320103920.