Inflammatory Gene Regulation in Diabetic Conditions

描述（由申请人提供）：糖尿病、胰岛素抵抗和代谢综合征与心血管疾病的发生率显著增加相关。炎症细胞因子和趋化因子引发的循环单核细胞异常活化与这种病理有关，但潜在的分子机制尚未完全了解。在之前的资助期内，我们提供了第一个证据，证明糖尿病在体外和体内通过新的核染色质重塑和潜在的表观遗传机制，包括转录因子、共激活因子和染色质组蛋白乙酰化之间的协同作用，导致单核细胞中的炎症基因转录。我们评估了在糖尿病刺激下体外培养的单核细胞，如高糖（HG）和晚期糖基化终产物（AGEs）配体，以及来自糖尿病患者的单核细胞。我们已经取得了很好的进展，完成了我们最初的大部分具体目标，并开始了一些新的研究。这个快速发展和动态的领域开辟了几个新的途径，将在这次更新中进行研究。我们已经发现了糖尿病条件下单核细胞炎症基因表达的令人兴奋的新机制，包括新型染色质因子的参与，以及调节染色质重塑和mRNA稳定性的关键microrna （mIRs）。因此，当前的更新将把我们的研究带到一个新的开拓水平，并通过揭示迄今为止尚未探索的与糖尿病体内和体外单核细胞功能障碍相关的基因调节机制，推动该领域的发展。该假说认为，糖尿病通过转录机制（包括染色质组蛋白修饰和miRs）以及转录后机制（包括mRNA稳定）导致单核细胞/巨噬细胞中炎症基因的表达增加。这将根据公布的和广泛的新初步数据，通过4个具体目标进行评估。目的1和2将确定糖尿病患者在体外培养单核细胞和体内单核细胞中如何通过这些基因启动子染色质的新变化导致炎症基因的转录。目的3将测试两种关键的新微rna （miRs）在糖尿病单核细胞/巨噬细胞中差异调节的功能作用。目的4将研究新的转录后机制，通过RNA结合蛋白和miRs之间的新相互作用，糖尿病刺激增加关键炎症基因mrna的稳定性。我们对转录组、表观基因组、核糖基因组和炎症小体之间的交叉对话进行了最先进和创新的评估，可以为糖尿病和胰岛素抵抗条件下介导单核细胞功能障碍的细胞事件提供新的见解。这些已完成的研究可以大大提高我们对糖尿病血管疾病的认识，并为糖尿病的衰弱性血管并发症发现新的治疗靶点。

DESCRIPTION (provided by applicant): Diabetes, insulin resistance and the metabolic syndrome are associated with significantly accelerated rates of cardiovascular disease. Abnormal activation of circulating monocytes triggered by inflammatory cytokines and chemokines has been implicated in this pathology but the underlying molecular mechanisms are not fully understood. In the previous funding period, we provided the first evidence that diabetic conditions in vitro and in vivo lead to inflammatory gene transcription in monocytes via novel nuclear chromatin remodeling and potential epigenetic mechanisms involving co-operative effects between transcription factors, coactivators and chromatin histone acetylation. We evaluated monocytes cultured in vitro with diabetic stimuli such as high glucose (HG) and ligands of advanced glycation end products (AGEs), as well as monocytes from diabetic patients. We have made excellent progress and completed most of our original Specific Aims and also initiated several new studies. This rapidly moving and dynamic field has opened several new avenues that will be investigated in this renewal. We have uncovered exciting new mechanisms of inflammatory gene expression in monocytes under diabetic conditions including the involvement of novel chromatin factors, and key microRNAs (mIRs) whose targets modulate chromatin remodeling as well as mRNA stability. The current renewal will thus take our studies to a new pioneering level and advance the field by unraveling hitherto unexplored mechanisms of regulation of genes associated with monocyte dysfunction in vitro and in vivo in diabetes. The hypothesis is that diabetic conditions lead to increased expression of inflammatory genes in monocyte /macrophages via transcriptional mechanisms involving chromatin histone modifications and miRs, as well as post-transcriptional mechanisms involving mRNA stabilization. This will be evaluated by 4 Specific Aims based on published and extensive new preliminary data. Aims 1 and 2 will determine how diabetic conditions in vitro in cultured monocytes and in vivo in monocytes from diabetic subjects lead to the transcription of inflammatory genes via novel changes in the chromatin at these gene promoters. Aim 3 will test the functional roles of two key new micro-RNAs (miRs) that are differentially regulated in diabetic monocytes /macrophages. Aim 4 will examine new post-transcriptional mechanisms by which diabetic stimuli increase the stability of key inflammatory gene mRNAs via novel interplay between RNA binding proteins and miRs. Our state-of-the-art and innovative assessments of the cross-talk between the transcriptome, epigenome, ribo-gnome and the inflammasome can provide new insights into cellular events mediating monocyte dysfunction under diabetic and insulin resistant conditions. These completed studies can greatly advance our knowledge of diabetic vascular disease and uncover new therapeutic targets for the debilitating vascular complications of diabetes.