Adipose tissue complement factor B promotes adipocyte maturation

• Published in: Biochemical and biophysical research communications 2018-01, Vol.495 (1), p.740-748
• Main Authors: Matsunaga, Hiroaki, Iwashita, Misaki, Shinjo, Takanori, Yamashita, Akiko, Tsuruta, Mitsudai, Nagasaka, Shoichiro, Taniguchi, Ataru, Fukushima, Mitsuo, Watanabe, Naoya, Nishimura, Fusanori
• Format: Article
• Language: English
• Subjects: 3T3-L1 Cells; 60 APPLIED LIFE SCIENCES; Adipocyte maturation; Adipocytes - cytology; Adipocytes - immunology; Adipogenesis - immunology; ADIPOSE TISSUE; Adipose Tissue - cytology; Adipose Tissue - immunology; Animals; Cell Differentiation - immunology; Cell Proliferation; Cells, Cultured; Complement factor B; Complement Factor B - immunology; Immunity, Innate - immunology; INSULIN; Lipid Droplets - immunology; LIPIDS; Male; METABOLIC DISEASES; METABOLISM; Mice; Mice, Transgenic; Obesity
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2017.11.069

It is well-known that the complement system plays an essential role in host immunity. Observational studies have indicated that complement system-related molecules such as complement factor B (CfB) and other components are correlated with obesity and/or insulin resistance parameters. In this study, we investigated the role of adipocyte-derived CfB in adipose tissue metabolism. We investigated the expression level of complement system-related genes in adipocytes. To understand the role of CfB in adipocyte, we performed Cfb overexpression in 3T3-L1 preadipocytes and generated adipocyte-specific Cfb transgenic mice. Cfb expression was markedly enhanced in 3T3-L1 adipocytes co-cultured with macrophages following endotoxin stimulation. In Cfb-overexpressing cells, the expression of adipocyte differentiation/maturation-related genes encoding peroxisome proliferator-activated receptor γ (Pparγ), adipocyte Protein 2 and perilipin was significantly enhanced. Cfb transgenic mice showed a marked increase in the expression of genes encoding Pparγ, perilipin, sterol regulatory element-binding protein 1 c, and Cd36 in the subcutaneous adipose tissue. CfB plays a crucial role in late-phase of adipocyte differentiation and subsequent lipid droplet formation. •Complement factor B protein is abundantly expressed in inflamed adipose tissue.•Serum complement factor B level showed a correlation with the degree of obesity.•Complement factor B promotes adipocyte maturation and lipid droplet formation.