中文摘要：

目的：研究叶瓜参长链碱（long-chain base from the sea cucumber Cucumaria frondosa,Cf-LCB）对3T3-L1前脂肪细胞分化的作用,并探讨其作用机制。方法：以四甲基偶氮唑蓝（methyl thiazolyl tetrazolium,MTT）法检测Cf-LCB对3T3-L1前脂肪细胞增殖活性的影响;采用传统鸡尾酒法诱导3T3-L1前脂肪细胞分化为成熟脂肪细胞,分别采用油红O染色和甘油三酯（triglycerides,TG）含量测定法评价其对3T3-L1前脂肪细胞分化的影响;反转录实时荧光定量聚合酶链式反应（quantity real-time reverse transcript polymerase chain reaction,q RT-PCR）法检测脂肪细胞分化关键基因CCAAT增强子结合蛋白α（CCAAT/enhancer binding protein alpha,C/EBPα）、过氧化物酶体增殖物激活受体γ（peroxisome proliferators-activated receptors gamma,PPARγ）以及WNT/β-catenin通路关键基因WNT10b（wingless-type MMTV integration site family members）、卷曲蛋白1（frizzled protein1,FZ1）、低密度脂蛋白受体相关蛋白6（LDL-receptor-related protein6,LRP6）和β-连环蛋白（β-catenin）的m RNA表达水平;Western blotting法检测WNT/β-catenin通路关键基因LRP6和β-catenin的蛋白表达量。结果：Cf-LCB能显著抑制3T3-L1前脂肪细胞的增殖;抑制3T3-L1细胞脂滴形成以及C/EBPα和PPARγm RNA表达;显著上调WNT/β-catenin通路关键基因FZ1、LRP6和β-catenin m RNA表达,对WNT10b的表达无影响;显著促进LRP6和β-catenin的蛋白表达,提高核内β-catenin含量。结论：Cf-LCB能够显著抑制3T3-L1前脂肪细胞分化,其作用机制与激活WNT/β-catenin通路有关。

英文摘要：

The aim of the present study was to observe the effect of Cf-LCB on the proliferation and differentiation of 3T3-L1 preadipocytes and to investigate the possible underlying mechanism. The effect of Cf-LCB on the proliferation of 3T3-L1 preadipocytes was evaluated by MTT assay. After using differentiation cocktail to differentiate 3T3-L1 preadipocytes, the effect of Cf-LCB on the differentiation of 3T3-L1 preadipocytes was evaluated by oil red O-staining and determining TG content. m RNA expression levels of key genes associated with differentiation and WNT/β-cateninsignal pathway in 3T3-L1 preadipocytes were measured by q RT-PCR. Expression levels of key proteins in WNT/β-catenin signal pathway were measured by Western blotting. Results showed that Cf-LCB significantly inhibited the proliferation of 3T3-L1 preadipocytes, prevented the formation of lipid droplets in mature 3T3-L1 adipocytes and down-regulated C/EBPαand PPARγ. The m RNA expression of FZ1, LRP6 and β-catenin was distinctly enhanced by Cf-LCB, suggesting activation of WNT/β-catenin pathway. The increased protein expressions of key factors in WNT/β-catenin pathway including LRP6, total and nuclear β-catenin further demonstrated that Cf-LCB could markedly suppress the proliferation and differentiation of 3T3-L1 preadipocytes by activating WNT/β-catenin pathway.