摘要
Disulfide-bond A oxidoreductase-like protein(DsbA-L)is a molecular chaperone involved in the multimeri-zation of adiponectin.Recent studies have found that DsbA-L is related to metabolic diseases including gestational diabetes mellitus(GDM),and can be regulated by peroxisome proliferator-activated receptorγ(PPARγ)agonists;the specific mechanism,however,is uncertain.Furthermore,the relationship between DsbA-L and the novel adipokine chemerin is also unclear.This article aims to investigate the role of DsbA-L in the improvement of insulin resistance by PPARγagonists in trophoblast cells cultured by the high-glucose simulation of GDM placenta.Immunohistochemistry and western blot were used to detect differences between GDM patients and normal pregnant women in DsbA-L expression in the adipose tissue.The western blot technique was performed to verify the relationship between PPARγagonists and DsbA-L,and to explore changes in key molecules of the insulin signaling pathway,as well as the effect of chemerin on DsbA-L.Results showed that DsbA-L was significantly downregulated in the adipose tissue of GDM patients.Both PPARγagonists and chemerin could upregulate the level of DsbA-L.Silencing DsbA-L affected the function of rosiglitazone to promote the phosphatidylinositol 3-kinase(PI3K)-protein kinase B(PKB)/AKT pathway.Therefore,it is plausible to speculate that DsbA-L is essential in the environment of PPARγagonists for raising insulin sensitivity.Overall,we further clarified the mechanism by which PPARγagonists improve insulin resistance.
目的:在高糖滋养细胞模型中,探讨二硫键A氧化还原酶样蛋白(DsbA-L)在过氧化物酶体增殖物激活受体γ(PPARγ)激动剂改善胰岛素抵抗过程中的作用,以及DsbA-L与趋化素(chemerin)的关系.创新点:发现DsbA-L在PPARγ激动剂改善胰岛素抵抗的过程中起作用,并首次证明chemerin能促进DsbA-L的表达水平.方法:采用免疫组织化学(IHC)和蛋白免疫印迹法(western blot)检测妊娠期糖尿病(GDM)患者与正常对照组孕妇的皮下脂肪组织中DsbA-L的定位和表达差异.在高糖滋养细胞模型中,通过western blot研究PPARγ激动剂和chemerin对DsbA-L蛋白的调节作用,并探究DsbA-L基因沉默对PPARγ激动剂调控胰岛素信号通路分子磷脂酰肌醇3激酶(PI3K)、蛋白激酶B(PKB/AKT)和细胞外信号调节激酶1/2(ERK1/2)蛋白表达的影响.结论:GDM患者的皮下脂肪组织中DsbA-L的水平较对照组低.PPARγ激动剂和chemerin均可增强DsbA-L蛋白的表达.DsbA-L基因沉默影响PPARγ激动剂对胰岛素信号PI3K-AKT通路的上调作用.
基金
Project supported by the National Key Research and Development Program of China(Nos.2016YFC1000405 , 2018YFC1002903)。
