葛根调节脂肪细胞糖脂代谢改善胰岛素抵抗的研究

Kudzu root( Ge-Gen) regulates on glucose and lipid metabolism to ameliorating insulin resistance on 3T3-L1 adipocytes

该实验通过检测葛根对胰岛素抵抗(IR)3T3-L1脂肪细胞葡萄糖消耗,甘油三脂(TG)含量及PPARγ,ADPN,GLUT4,LPL,FABP4,FASn表达量的影响来探讨葛根调节糖脂代谢改善脂肪IR的作用机制。先采用3T3-L1前脂细胞诱导分化的成熟脂肪细胞,地塞米松诱导建立IR模型,将脂肪细胞分为正常组,IR模型组,罗格列酮阳性组,低、中、高剂量葛根含药血清组,以葡萄糖氧化酶-过氧化物酶(glucose oxidase-peroxidase,GOD-POD)法检测细胞培养液葡萄糖含量和甘油磷酸氧化酶(glycerol phosphate oxidase,GPO-POD)法测定胞内TG含量,荧光定量q PCR检测PPARγ,ADPN,GLUT4,LPL,FABP4(a P2),FASn基因mRNA水平。结果显示1μmol·L^(-1)地塞米松作用3T3-L1脂肪细胞96 h,与正常组比较,模型组葡萄糖消耗量降低(P<0.01),胞内TG含量增加(P<0.01),由此确认建立IR模型;与IR组比较,葛根含药血清干预IR细胞24 h葡萄糖消耗量上升(P<0.01),胞内TG含量降低(P<0.01),中、高剂量葛根含药血清组升高PPARγ,ADPN和GLUT4表达(P<0.01),PPARγ与后两者基因表达呈现一致性。脂代谢相关基因检测结果显示仅高剂量葛根含药血清显著升高LPL表达(P<0.05);各剂量葛根含药血清下调FABP4表达(P<0.01);中、高剂量的葛根含药血清上调FASn基因表达(P<0.01)。该实验表明葛根提高IR-3T3-L1脂肪细胞对葡萄糖的摄取能力,降低细胞内TG积聚,干预多个重要糖脂代谢基因,推测以PPARγ为中心多靶点调节糖脂代谢改善脂肪IR。

This study aimed to explore the mechanism of Chinese traditional medicine, Kudzu root （Chinese name：Ge-Gen; Latin name： Puerariae Lobatae Radix） how to improving insulin resistance （IR） through the regulation of the glucose and lipid metabolism in the IR-3T3-L1 adipocytes. After the 3T3-L1 mouse preadipocytes were differentiated into mature adipocytes, IR model （ IR-3T3-L1 ） was built with 1 μmol L-l dexamethasone treatment for 96 h. IR adipocytes were treated with different concentrations （5 %, 10% and 15% ） of Ge-Gen containing serum （GG-CS）for 12 h or 24 h, whereas rosiglitazone group as positive control in this study. The glucose contents in cell culture supernatants were detected by glucose oxidase assay and the intracellular triglyceride （TG） contents were meas- ured by glycerol phosphate oxidase assay respectively. The mRNA expression levels of PPART, ADPN, GLUT4, LPL, FABP4 and FASn gene were determined by real-time quantitative PCR （qPCR）. Results showed that IR-3T3-L1 adipocytes significantly increased glucose consumption （P 〈0. 01 ）and decreased TG contents （P 〈0. 01 ） as compared with the normal control group, the glucose con- sumption significantly increased with the treatment of GG-CS （P 〈 0. 01 ） by dose-dependent and time-dependent manners ,whereas the intracellular TG content was sigificantly decreased （P 〈 0. O1 ） by dose-dependent manner, qPCR analysis revealed that 10% and 15% GG-CS significantly up-regnlated the mRNA expression level of PPART, ADPN and GLUT4 （P 〈 0.01 ） with the same dose-dependent manner,whereas the GLUT4 mRNA expression was showed similar expression pattern with the treatment of 10% and 15% GG-CS （P 〈 0. 01 ）. We also detected the mRNA expression levels of several important lipid-metabolizing enzymes such as LPL, FASn and FABP4 by PPART regulation. 15% GG-CS elevated LPL mRNA expression （P 〈 0. 05） ;10% and 15% GG-CS enhanced the FASn mRNA expression （ P 〈 0. 01 ）, whereas 5% , 10% and 15 % GG-CS down-regulated FABP4 mRNA expression （ P 〈 0.01 ）. Together, our re- suits indicated that GG could regulate the glucose and lipid metabolism to ameliorate IR with multi-target manners in 333-L1 adipo- cytes.