肿瘤坏死因子-α对脂肪细胞脂联素和炎症因子mRNA表达的影响

Effect of Tumor Necrosis Factor-α on Expression of Adiponectin mRNA and Inflammation Cytokines in Adipocytes

目的:探讨肿瘤坏死因子-α(TNF-α)在肥胖-炎症-胰岛素抵抗(IR)-2型糖尿病(T2DM)的病生理过程中的作用。方法:(1)培养前脂肪细胞3T3-L1细胞,并观察其诱导分化成熟过程中过氧化物酶体增殖活化受体-γ(PPAR-γ)mRNA、脂联素(ADPN)mRNA的表达情况。(2)以高浓度(20μg/L)的TNF-α处理分化成熟的脂肪细胞0.5、4、8、24h,提取总RNA,采用实时定量逆转录聚合酶链反应检测ADPN mRNA、PPAR-γmRNA、TNF-αmRNA、白细胞介素(IL)-6mRNA、IL-1βmRNA的表达情况。结果:(1)3T3-L1细胞诱导分化过程中ADPN mRNA的表达呈逐渐上升趋势,诱导后PPAR-γmRNA增加。(2)分化成熟的脂肪细胞中ADPN mRNA表达水平在TNF-α处理0.5、4、8h后随着时间延长逐渐下降,8h时降至最低(P<0.01)。0.5h后PPAR-γmRNA表达水平并未出现明显下降,4、8、24h时均低于对照组(P<0.01),4h时降至最低。TNF-α处理0.5h后TNF-αmRNA表达水平明显上升,并于4h时达峰值,各处理组均高于对照组(P<0.01);0.5h后IL-6mRNA表达水平明显升高,各处理组均高于对照组(P<0.01)。空白组、对照组和各TNF-α处理组IL-1βmRNA的表达差异无统计学意义(P>0.05)。结论:本实验从分子生物学水平证实了TNF-α参与肥胖-炎症-IR-T2DM的过程。

Objective： To investigate the role of tumor necrosis factor（TNF）–α in the pathophysiological course of obesity-inflammation-insulin resistance（IR）-type 2 diabetic mellitus（T2DM）.Methods： Preadipocytes,3T3-L1,was cultured and induced into mature adipocytes.The expressions of adiponectin （ADPN） mRNA,peroxisome proliferator-activated receptors （PPAR）-γ mRNA were observed in the differential course of the adipocytes.The expressions of ADPN mRNA,PPAR-γ mRNA,TNF-α mRNA,interleukin （IL）-6 mRNA and IL-1β mRNA were observed in mature adipocytes which were treated with high concentration（20 μg/L）of the recombinant TNF-α under diverse phase.Results： The levels of ADPN mRNA and PPAR-γ mRNA expression were upregulated gradually within the differential course of 3T3-L1 adipocytes.The results of the gene expression in adipocytes treated by TNF-α were as following： The expressions of ADPN mRNA and PPAR-γ mRNA decreased with time-dependent manner and reached the lowest at 8 h （P 0.01）.The expressions of TNF-αmRNA and IL-6 mRNA increased significantly（P 0.01）.The expression of IL-1β mRNA didn’t show significant change（P 0.05）.Conclusion： The inflammation hypothesis on etiologic mechanism of T2DM was studied at molecular level in this work.TNF-α plays an important role in the course of obesity-inflammation-IR-T2DM.