Glucagon-like peptide 1 regulates adipogenesis in 3T3-L1 preadipocytes
Glucagon-like peptide 1 regulates adipogenesis in 3T3-L1 preadipocytes
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DOI：
10.3892/ijmm.2013.1350
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发表时间：
2013-06-01
影响因子：
5.4
通讯作者：
Chen, Li
中科院分区：
文献类型：
--
作者：
Yang, Junpeng;Ren, Jianmin;Chen, Li
胰高血糖素样肽1 （Glucagon-like peptide 1, GLP-1）是一种肠道来源的肽，据报道对代谢和降低胰岛素抵抗有深远的影响。前脂肪细胞分化刺激的脂肪细胞增生对脂肪组织胰岛素敏感性有积极影响。然而，GLP-1是否在脂肪形成中起作用尚不清楚。在这项研究中，我们研究了GLP-1对前脂肪细胞分化的影响，并研究了可能参与这种影响的机制。在我们的3T3-L1细胞研究中，我们测试了脂肪细胞分化过程中脂肪细胞特异性标记物和信号通路的水平。此外，油红0染色检测脂质积累。使用Image Pro Plus 5.02软件分析脂滴的大小和数量。我们发现，在313-L1前脂肪细胞分化过程中，GLP-1以剂量依赖性的方式提高了游离脂肪酸结合蛋白4 （aP2）和转录因子过氧化物酶体增殖物激活受体γ (ppar - γ)的蛋白表达水平。RT-PCR结果显示，GLP-1在转录水平上促进了CCAAT/增强子结合蛋白α (C/EBP α)和脂蛋白脂肪酶（LPL）的表达。这些数据表明GLP-1促进前脂肪细胞分化。我们的研究还发现，100 nM GLP-1处理细胞在分化的前24小时内增强了Akt信号的磷酸化。虽然油红0染色显示GLP-1对脂肪堆积没有显著影响，但100 nM GLP-1处理的细胞中小脂肪细胞数量增加。综上所述，这些结果表明GLP-1调控313-L1脂肪形成，Akt信号通路可能参与了这一过程。分化的小脂肪细胞可能对胰岛素抵抗和肥胖有积极作用。
Glucagon-like peptide 1 (GLP-1), a gut-derived peptide, has been reported to have profound effects on metabolism and to reduce insulin resistance. Adipocyte hyperplasia stimulated by preadipocyte differentiation has a positive effect on adipose tissue insulin sensitivity. However, it remains less clear whether GLP-1 plays a role in adipogenesis. In this study, we examined the effect of GLP-1 on preadipocyte differentiation and investigated the mechanisms that may be involved in this effect. In our 3T3-L1 cell study, we tested the levels of adipocyte-specific markers and signaling pathways during preadipocyte differentiation. In addition, Oil Red 0 staining was used to examine lipid accumulation. Image Pro Plus 5.02 was used to analyze the size and number of lipid droplets. We found that GLP-1 elevated the protein expression levels of free fatty acid-binding protein 4 (aP2) and the transcription factor peroxisome proliferator-activated receptor-gamma (PPAR-gamma) in a dose-dependent manner during 313-L1 preadipocyte differentiation. Furthermore, RT-PCR results showed that GLP-1 promoted CCAAT/enhancer-binding protein alpha (C/EBP alpha) and lipoprotein lipase (LPL) expression at the transcriptional level. These data suggest that GLP-1 promotes preadipocyte differentiation. Our study also found that treatment of the cells with 100 nM GLP-1 enhanced the phosphorylation of Akt signaling during the first 24 h of differentiation. Although Oil Red 0 staining showed that GLP-1 had no significant effect on lipid accumulation, there were increased numbers of small adipocytes in the cells treated with 100 nM GLP-1. Taken together, these results indicate that GLP-1 regulates 313-L1 adipogenesis and the Akt signaling pathway may be involved in this process. The differentiated small adipocytes may have a positive effect against insulin resistance and obesity.