Comprehensive analysis of different in vitro insulin resistance models

Diet-induced obesity (DIO) predisposes individuals to insulin resistance, and adipose tissue has a major role in the disease. Insulin resistance can be induced in cultured adipocytes by a variety of treatments, but what aspects of the in vivo responses are captured by these models remains unknown. We use global RNA sequencing to investigate changes induced by TNF-a, hypoxia, dexamethasone, high insulin, and a combination of TNF-a and hypoxia, comparing the results to the changes in white adipose tissue from DIO mice. We found that different in vitro models capture distinct features of DIO adipose insulin resistance, and a combined treatment of TNF-a and hypoxia is most able to mimic the in vivo changes. Using genome-wide DNase I hypersensitivity followed by sequencing, we further examined the transcriptional regulation of TNF-a-induced insulin resistance, and we found that C/EPBß key regulator of adipose insulin resistance. RNA-seq for 6 insulin resistance conditions and 2 control conditions, Dnase hypersensitivity-seq of 4 conditions and 1 control condition, ChIP-seq on p65 after TNFa treatment.

饮食诱导肥胖（Diet-induced obesity, DIO）会使个体罹患胰岛素抵抗的风险升高，而脂肪组织在该疾病的发生发展中发挥关键作用。多种处理方式可在体外培养的脂肪细胞中诱导胰岛素抵抗，但目前尚不清楚这些体外模型能够复现体内应答的哪些特征。我们采用全局RNA测序（RNA sequencing），探究肿瘤坏死因子-α（Tumor necrosis factor-α, TNF-α）、缺氧、地塞米松、高胰岛素以及TNF-α联合缺氧处理所诱导的基因表达变化，并将上述结果与DIO小鼠白色脂肪组织中的基因表达变化进行对比分析。研究结果显示，不同的体外模型仅能复现DIO脂肪组织胰岛素抵抗的部分特征，其中TNF-α联合缺氧处理最能够模拟体内的基因表达变化。我们进一步通过全基因组DNase I超敏位点测序（DNase I hypersensitivity sequencing）分析了TNF-α诱导的胰岛素抵抗的转录调控机制，鉴定出C/EBPβ是脂肪组织胰岛素抵抗的关键调控因子。本数据集包含6种胰岛素抵抗处理条件与2种对照条件的RNA-seq数据、4种处理条件与1种对照条件的DNase超敏位点测序数据，以及TNF-α处理后p65的染色质免疫沉淀测序（ChIP-seq）数据。