Matsunaga Hiroaki, Iwashita Misaki, Shinjo Takanori, Yamashita Akiko, Tsuruta Mitsudai, Nagasaka Shoichiro, Taniguchi Ataru, Fukushima Mitsuo, Watanabe Naoya, Nishimura Fusanori
Section of Periodontology, Kyushu University Faculty of Dental Science, Fukuoka, Japan.
Division of Diabetes, Metabolism and Endocrinology, Showa University Fujigaoka Hospital, Yokohama, Japan.
Biochem Biophys Res Commun. 2018 Jan 1;495(1):740-748. doi: 10.1016/j.bbrc.2017.11.069. Epub 2017 Nov 11.
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.
众所周知，补体系统在宿主免疫中起重要作用。观察性研究表明，补体系统相关分子如补体因子B（CfB）和其他成分与肥胖和/或胰岛素抵抗参数相关。在本研究中，我们调查了脂肪细胞源性CfB在脂肪组织代谢中的作用。
我们研究了脂肪细胞中补体系统相关基因的表达水平。为了解CfB在脂肪细胞中的作用，我们在3T3-L1前脂肪细胞中进行了Cfb过表达，并生成了脂肪细胞特异性Cfb转基因小鼠。
在内毒素刺激后，与巨噬细胞共培养的3T3-L1脂肪细胞中Cfb表达明显增强。在过表达Cfb的细胞中，编码过氧化物酶体增殖物激活受体γ（Pparγ）、脂肪细胞蛋白2和脂滴包被蛋白的脂肪细胞分化/成熟相关基因的表达显著增强。Cfb转基因小鼠皮下脂肪组织中编码Pparγ、脂滴包被蛋白、固醇调节元件结合蛋白1c和Cd36的基因表达明显增加。
CfB在脂肪细胞分化后期及随后的脂滴形成中起关键作用。
