Ⅲ型纤连蛋白组件包含蛋白5通过抑制ERK1/2磷酸化抑制C3H10T1/2细胞成脂分化

旨在探究Ⅲ型纤连蛋白组件包含蛋白5（typeⅢ domain-containing protein5，FNDC5）对C3H10T1/2细胞成脂分化的调控作用。利用qRT-PCR和Western 印迹检测FNDC5在C3H10T1/2细胞成脂分化过程中的时序性表达规律；构建慢病毒包被的过表达/干扰FNDC5载体，转染C3H10T1/2细胞，采用qRT-PCR检测成脂分化关键基因的表达情况，油红O染色检测脂滴含量，利用Western 印迹检测细胞外信号调节激酶（extracellularregulatedkinase1/2，ERK1/2）及磷酸化ERK1/2（P-ERK1/2）的表达水平。C3H10T1/2细胞成脂诱导分化8d，Fndc5的表达量明显升高（P＜0.05）；C3H10T1/2细胞中过表达FNDC5，成脂分化关键基因过氧化物酶体增殖物激活受体-γ（peroxisome proliferator--activated receptor-γ,PPARγ）、脂肪酸结合蛋白4（fatty acid binding protein 4,FABP4）和CCAAT增强子结合蛋白α（CCAAT enhancer binding protein alpha,C/EBPα）的表达量显著降低（P＜0.01），CCAAT增强子结合蛋白β（CCAAT enhancer binding protein beta,C/EBPβ）表达量明显降低（P＜0.05），脂滴含量明显减少，P-ERK1/2的含量明显降低（P＜0.05）。C3H10T1/2细胞中干扰FNDC5，成脂分化关键基因PPARγ、C/EBPβ、FABP4和C/EBPα的表达量显著升高（P＜0.01），脂滴含量明显增加，P-ERK1/2的含量明显升高（P＜0.05）。本研究发现，FNDC5可以通过抑制ERK1/2的磷酸化水平，抑制C3H10T1/2细胞的成脂分化，为FNDC5调控脂肪沉积的机制研究提供参考数据。

FNDC5 Regulates the Adipogenic Differentiation of C3H10T1/2 Cells by Inhibiting the Phosphorylation of ERK1/2

The aim of this study was to explore the regulatory mechanism of Type Ⅲ domain-containing protein5 (FNDC5) on adipogenic differentiation in C3H10T1/2 cells. qRT-PCR and Western blot were used to detect the expression of FNDC5 during adipogenic differentiation of C3H10T1/2 cells. The lentivirus-coated overexpression and interference vector of FNDC5 were constructed and transfected into C3H10T1/2 cells. qRT-PCR was used to detect the expression of the key genes of adipogenic differentiation. Oil red O staining was used to detect the formation of lipid droplets; Western blot was used to detect the content of ERK1/2 and ERK1/2 phosphorylated protein (P-ERK1/2). After 8 days of adipogenic differentiation of C3H10T1/2 cells, the expression of Fndc5 increased significantly. After overexpression of FNDC5 in C3H10T1/2 cells, the expression of key genes for adipogenic differentiation, including peroxisome proliferator-activated receptor-γ (PPARγ), CCAAT enhancer binding protein beta (C/EBPβ), fatty acid binding protein 4(FABP4) and CCAAT enhancer binding protein alpha (C/EBPα), all decreased significantly. The content of lipid droplets and P-ERK1/2 also decreased significantly. On the contrary, after interference of FNDC5 in C3H10T1/2 cells, the expression of key genes for adipogenic differentiation, including PPARγ, C/EBPβ, FABP4 and C/EBPα were significantly increased. Meanwhile, the content of lipid droplets and P-ERK1/2 also increased significantly. This study found that FNDC5 can inhibit the adipogenic differentiation of C3H10T1/2 cells by inhibiting the phosphorylation level of ERK1/2, which can provide reference data for the mechanism of FNDC5 in regulating fat deposition.