虎杖苷对3T3-L1前脂肪细胞增殖与分化的影响及其作用机制

Effects of Polydatin on Proliferation and Differentiation of Murine 3T3-L1 Preadipocytes and Its Mechanisms

目的:探讨虎杖苷(polydatin,PD)对于小鼠3T3-L1前脂肪细胞增殖与分化的影响及其作用机制。方法:培养小鼠3T3-L1前脂肪细胞,添加不同剂量虎杖苷分别处理24、48 h,用MTT法检测细胞增殖;在诱导3T3-L1前脂肪细胞分化的过程中添加不同剂量虎杖苷处理48 h,继续培养6 d后油红O染色观察脂肪细胞的分化程度;采用荧光定量PCR技术检测各组过氧化物酶体增殖物激活受体γ(PPARγ)、CCAAT/增强子结合蛋白-α(C/EBPα)、单核细胞趋化因子-1(MCP-1)和瘦素(Leptin)的mRNA表达水平;酶联免疫吸附法(ELISA)分析3T3-L1分化过程中虎杖苷对MCP-1蛋白分泌的影响。结果:PD显著促进3T3-L1前脂肪细胞增殖,并呈现一定的时间、剂量依赖效应。与对照组相比,PD抑制3T3-L1细胞分化;低剂量PD(20μmol·L^(-1))导致脂肪细胞中分化相关基因PPARγmRNA表达水平下降,并且可以抑制3T3-L1前脂肪细胞向脂肪细胞分化过程中炎症相关因子MCP-1的mRNA表达和蛋白分泌。高剂量PD(100μmol·L^(-1))对于PPARγmRNA表达水平影响不明显,不过可以使3T3-L1细胞分化过程中MCP-1的mRNA表达和蛋白分泌水平升高。添加低剂量和高剂量的PD导致成熟脂肪细胞中Leptin mRNA表达水平升高。结论:PD可以促进3T3-L1前脂肪细胞增殖,抑制前脂肪细胞分化,其机制可能是通过抑制PPARγ的表达。在3T3-L1前脂肪细胞分化过程中,PD通过抑制脂肪细胞中炎症相关因子MCP-1的表达及分泌,及增加Leptin基因表达,可能可以通过调控炎症状态影响肥胖。

Objective ： To investigate the effect of polydatin on proliferation and differentiation of murine 3T3 - LI preadipocytes and its mechanisms. Methods ：3T3 -L1 preadipocytes were cultured and treated with polydatin （PD） at different dosages for 24 h or 48 h, and cell proliferation was analyzed by a MTr method. The effects of PD on 3T3 - L1 differentiation were also evaluated at concentrations of 20 μmol/L and 100 μmol/L and oil red O staining was conducted to analyze the degree of differentiation. The qRT - PCR method was used to detect the mRNA expression levels of PPARγ （ peroxisome proliferator - activated receptor gamma）, C/EBPα （ CCAAT/enhancer - binding protein - α）, MCP - 1 （monocyte chemotactic protein 1 ） and Leptin. ELISA （enzyme linked immunosorbent assay） was employed to detect the secretion of MCP - 1. Results ：PD promoted the proliferation of 3T3 - L1 preadipocytes with a time - dose dependent man- ner. PD significantly inhibited the capacity of 3T3 - L1 cells differentiated into mature adipocytes. Administration of low dose of PD （20 μmol/L） downregulated PPAR-γ expressions in differentiated adipocytes. Additionally, mRNA and protein secretion of MCP - 1 were also inhibited by low dose PD during the differention of 3T3 - L1 cells. High dose of PD （100 μmol/L） treatment had no obvious influence on PPARγ mRNA expression, whereas can significantly upregulate mRNA expression and protein secretion of MCP - 1 in mature adipocytes. Moreover, low and high dose of PD significantly increased mRNA levels of Leptin especially in mature adipocytes. Conclusion ： PD can promote the proliferation of 3T3 - L1 preadipocytes, and inhibit the differentiation of 3T3 - L1 by inhibiting the expression of PPARγ. PD can suppress the expression and secretion of MCP - 1 as well as increase Leptin expressing, indicating PD plays an anti - inflammatory role in obesity.