异甘草素对3T3-L1前脂肪细胞分化的抑制作用

Isoliquiritigenin Inhibits the Differentiation of 3T3-L1 Preadipocytes

目的:考察异甘草素对3T3-L1前脂肪细胞分化的影响,探究其作用机制。方法:采用3T3-L1前脂肪细胞,利用磺酰罗丹明B(sulforhodamine B,SRB)法检测异甘草素对3T3-L1前脂肪细胞增殖的影响,采用传统的鸡尾酒法诱导3T3-L1细胞分化为脂肪细胞,利用油红O染色法检测分化细胞脂滴形成;采用实时荧光定量逆转录聚合酶链式反应方法,检测细胞CCAAT增强子结合蛋白(CCAAT-enhancer-binding proteins,C/EBP)亚型C/EBPα、C/EBPβ、脂肪酸合成酶(fatty acid synthetase,FAS)、脂肪分化相关蛋白adipophilin、过氧化物酶体增殖物激活受体γ(peroxisome proliferators activated receptorγ,PPARγ)、腺苷酸活化蛋白激酶(adenosine monophosphate activated protein kinase,AMPK)的mRNA表达水平,Western blotting法检测AMPK蛋白磷酸化水平。结果:异甘草素可浓度依赖性地抑制3T3-L1细胞增殖,并明显抑制分化细胞内脂滴形成,同时抑制了细胞分化相关基因C/EBPα、C/EBPβ、FAS、adipophilin、PPARγ mRNA的表达,AMPK m RNA的表达未受影响,但异甘草素处理明显上调了AMPK蛋白的磷酸化水平。结论:异甘草素可抑制3T3-L1前脂肪细胞向脂肪细胞分化,其机制可能与活化AMPK信号通路相关。

Objective： To investigate the potential effects and underlying mechanisms of isoliquiritigenin on the differentiation of 3T3-L1 preadipocytes. Methods： The SRB assay was used to evaluate the effects of isoliquiritigenin on the proliferation of 3T3-L1 preadipocytes. The differentiation of 3T3-L1 cells was induced by cocktail reagents. The formation of lipid droplets in the differentiated adipocytes was observed after oil red O staining and quantified by colorimetry. The expression of CCAAT-enhancer-binding proteins（C/EBP）-α and-β, fatty acid synthetase（FAS）, adipophilin, peroxisome proliferators activated receptor γ（PPARγ） and adenosine monophosphate activated protein kinase（AMPK） genes was measured by quantity real-time reverse transcript polymerase chain reaction（q RT-PCR）. The phosphorylation of AMPK protein was detected by Western blotting. Results： Isoliquiritigenin inhibited the proliferation of 3T3-L1 preadipocytes in a concentration-dependent manner. The isoliquiritigenin treatment significantly decreased the formation of lipid droplets in differentiated adipocytes. Furthermore, isoliquiritigenin down-regulated the m RNA expression of C/EBPα, C/EBPβ, FAS, adipophilin, and PPARγ genes. On the other hand, isoliquiritigenin had no obvious effects on the m RNA expression of AMPK gene, but up-regulated the phosphorylation of AMPK. Conclusion： Isoliquiritigenin could inhibit the proliferation and differentiation of 3T3-L1 preadipocytes due to the activation of AMPK signal pathway.