木犀草苷对3T3-L1前脂肪细胞分化和脂代谢的影响

Effect of Luteoloside on 3T3-L1 Preadipocyte Differentiation and Lipid Metabolism

目的:研究木犀草苷对3T3-L1前脂肪细胞分化和脂代谢的影响及其作用机制。方法:采用3T3-L1前脂肪细胞,利用四甲基偶氮唑蓝法检测不同质量浓度木犀草苷对3T3-L1前脂肪细胞毒性的影响;使用鸡尾酒诱导法诱导细胞分化,用油红O染色观察脂滴形成情况;测定分化后细胞中甘油三酯、总胆固醇的含量以及相关炎症因子如肿瘤坏死因子(tumor necrosis factor,TNF)-α、白细胞介素(interleukin,IL)-6、IL-10、瘦素(leptin,LEP)和脂联素(adiponectin,ADPN)的分泌量;利用Western Blot法检测细胞过氧化物酶体增殖物激活受体(peroxisome proliferators activated receptor,PPAR)γ、CCAAT增强子结合蛋白(CCAAT-enhancer-binding proteins,C/EBP)-α、固醇调节元件结合蛋白1(sterol regulatory element-binding protein 1,SREBP1)、PPARα、解偶联蛋白1(uncoupling protein 1,UCP-1)、肉碱棕榈酰转移酶1(carnitine palmitoyltransferase 1,CPT-1)蛋白的相对表达水平。结果:3T3-L1前脂肪细胞存活率随木犀草苷质量浓度的升高整体呈降低趋势,木犀草苷质量浓度在5~60μg/mL时细胞存活率均在80%以上。木犀草苷处理组可显著抑制3T3-L1前脂肪细胞的分化,减少脂质积累;木犀草苷可下调成脂分化后细胞中总胆固醇、甘油三酯的含量以及炎症因子TNF-α、IL-6和LEP的分泌量,上调IL-10和ADPN的分泌量;木犀草苷能下调PPARγ、C/EBP-α和SREBP1蛋白的相对表达水平,上调PPARα、UCP-1和CPT-1蛋白的相对表达水平。结论:木犀草苷可以抑制3T3-L1前脂肪细胞分化和影响脂代谢,其机制一方面是下调PPARγ、C/EBP-α和SREBP1蛋白表达,抑制脂肪合成;另一方面是激活PPARα上调下游蛋白,促进脂肪消耗;木犀草苷还可能通过调节细胞因子的分泌量,促进细胞脂解,从而改善脂代谢失衡。

Objective:To study the effect and mechanism of luteoloside on the differentiation and lipid metabolism of 3T3-L1 preadipocytes.Methods:The cytotoxicity of different concentrations of luteoloside on 3T3-L1 preadipocyte was detected using methyl thiazolyl tetrazolium(MTT)assay.Cell differentiation was induced by the cocktail method,and lipid droplets were observed by oil red O staining.The contents of triglyceride and total cholesterol in differentiated cells,as well as the secretion of related inflammatory factors such as tumor necrosis factor-α(TNF-α),interleukin(IL)-6,IL-10,leptin(LEP)and Adiponectin(ADPN)were measured.The relative expression levels of peroxisome proliferators activated receptor(PPAR)γ,CCAAT-enhancer-binding proteins(C/EBP)-α,sterol regulatory elementbinding protein 1(SREBP1),PPARα,uncoupling protein 1(UCP-1),and carnitine palmitoyltransferase 1(CPT-1)were analyzed by Western blotting.Results:The survival rate of 3T3-L1 preadipocytes decreased with the increase in luteoloside concentration,being above 80%at luteoloside concentrations of 5–60μg/mL.Treatment with luteoloside significantly inhibited the differentiation of 3T3-L1 preadipocytes and reduced lipid accumulation.Luteoloside downregulated the contents of TC and TG,the secretion of TNF-α,IL-6 and LEP,but up-regulated the secretion of IL-10 and ADPN.Luteoloside down-regulated the protein expression levels of PPARγ,C/EBP-αand SREBP1,but up-regulated those of PPARα,UCP-1 and CPT-1.Conclusion:Luteoloside can suppression the differentiation and lipid metabolism of 3T3-L1 preadipocytes.The mechanism may be that luteoloside down-regulates the protein expression of PPARγ,C/EBP-α,and SREBP1 to inhibit fat synthesis.Furthermore,it activates PPARαto upregulate downstream proteins and promote fat consumption.Luteoloside may also regulate the secretion of cytokines and promote cellular lipolysis,thus improving lipid metabolism imbalance.