摘要
目的:观察熊果酸对3T3-L1脂肪细胞胰岛素抵抗模型葡萄糖消耗、摄取及细胞分化的影响,并探讨其作用机制。方法:将3T3-L1前脂肪细胞诱导分化为成熟脂肪细胞,用高糖、高胰岛素联合诱导胰岛素抵抗模型。使用葡萄糖氧化酶法检测3T3-L1细胞葡萄糖消耗量,氚标葡萄糖法检测其葡萄糖摄取量,以评价模型建立情况。用四唑盐(methyl thiazolyl tetrazolium,MTT)比色法检测不同浓度熊果酸对3T3-L1脂肪细胞活力的影响以确定实验药物浓度。加入不同浓度熊果酸分组干预,用氚标葡萄糖法检测脂肪细胞葡萄糖摄取量;用油红O染色法检测3T3-L1脂肪细胞分化情况;用实时荧光定量聚合酶链反应法、蛋白质印迹法分别观察熊果酸对3T3-L1细胞胰岛素抵抗模型细胞分化相关蛋白脂肪细胞脂类结合蛋白、基质金属蛋白酶1和原癌基因Cb1相关蛋白(c-Cbl-associated protein,CAP)表达的影响。结果:在成功建立胰岛素抵抗模型的基础上,使用MTT法检测细胞活力,确定熊果酸的作用浓度在4～20μmol/L。与模型组相比,低、高剂量熊果酸组(10、20μmol/L)及罗格列酮组(5μmol/L)葡萄糖摄取均明显升高(P<0.01);低、高剂量熊果酸组3T3-L1脂肪细胞分化程度低于对照组和罗格列酮组。熊果酸可明显上调3T3-L1细胞胰岛素抵抗模型CAP mRNA及蛋白的表达(P<0.01)。结论:熊果酸改善3T3-LI脂肪细胞胰岛素抵抗模型糖代谢的同时可抑制其分化,这一机制可能与熊果酸上调脂肪细胞CAP的表达有关。
OBJECTIVE： To observe the effects of ursolic acid （UA） on insulin resistance and cell differentiation in 3T3- L1 adipocytes and to explore the mechanisms. METHODS： 3T3-L1 adipocytes were cultured in Dulbecco＇ s modified Eagle＇ s medium （DMEM） supplemented with glucose （25 mmol/L） and insulin （10-6 mol/L） to induce insulin resistance. After culture, glucose consumption of the adipocytes was detected by glucose oxidase method and glucose uptake was detected by using tritium-marked glucose. Drug concentration for following test was determined through detecting the effects of different concentrations of UA on the activity of 3T3-L1 adipocytes with insulin resistance by methyl thiazolyl tetrazolium （MTT） staining. 3T3-L1 adipocytes with insulin resistance were cultured with DMEM, rosiglitazone, and low- and high-dose UA, and then, glucose uptake and differentiation of 3T3-L1 adipocytes were detected. Finally, real-time fluorescence quantitative polymerase chain reaction and Western blot methods were used to detect the effects of UA on expressions of adipocyte lipid binding protein （aP2）, c-Cbl- associated protein （CAP） and matrix metalloproteinase-1 （MMP-1） in 3T3-L] cells with insulin resistance. RESULTS： After dealing with high glucose/hyperinsulin for 24 h, insulin resistance was induced successfully in the 3T3-L1 adipocytes. The concentrations of UA were defined to be 4： to 20 ffmol/L. Compared with the model group, the glucose uptake was significantly increased in the rosiglitazone group and groups treated with low- and high-dose UA （P-~0.01）. The differentiation levels of 3T3-L1 adipocytes in the UA groups were lower than those in the control group and the rosiglitazone group. Effects of UA on the expressions of aP2 and MMP-1 were not obvious, but UA could up-regulate expression of CAP both in mRNA and protein levels （P〈0.01）. CONCLUSION： Low- and high-dose UA can improve the glycometabolism and differentiation of 3T3-L1 adipocytes with insulin resistance b
出处
《中西医结合学报》
CAS
2012年第8期886-893,共8页
Journal of Chinese Integrative Medicine
基金
国家自然科学基金资助项目(No.81073116)
