Nuclear Mechanisms of VSMC Gene Regulation and Cellular Interactions in Diabetes

描述(申请人提供)：心血管并发症，如高血压和动脉粥样硬化，在糖尿病人群中非常普遍。有证据支持与血管炎症相关的基因在糖尿病血管疾病发病机制中的作用。然而，关于调控血管平滑肌细胞(VSMC)中这些基因的微妙分子机制或关键核因素，或它们在体内的功能相关性，人们知之甚少。最近的研究表明，糖尿病血管并发症在没有进行强化血糖控制的患者中继续发展。基于我们新的支持性数据，我们认为血管细胞中基因调控的新的“表观遗传”染色质重塑机制可能介导了这种“糖尿病记忆”现象。我们的数据还表明，在糖尿病条件下，VSMC在体外或体内通过这些核机制激活的基因可以导致VSMC与内皮下间隙的单核细胞之间的密切相互作用。我们的中心假设是糖尿病刺激，如高糖(HG)和晚期糖基化终末产物(AGEs)，通过体内新的核染色质重塑机制诱导VSMC中的炎性趋化因子和细胞因子。这些因素可诱导血管炎症、VSMC-单核细胞相互作用和表型改变，从而导致心血管疾病的加速发生。 具体目的1是研究糖尿病刺激导致VSMC趋化基因表达的核转录机制。在这里，我们将使用功能增益法和功能损失法确定核转录因子和关键染色质因子之间的核相互作用。具体目的2是评估这些核机制和因子在来源于糖尿病小鼠模型的VSMC和主动脉中的体内相关性。在这里，我们将确定在这些糖尿病细胞中观察到的与高血糖记忆、持续的基因表达和激活的潜在关联。具体目标3和4是为了确定糖尿病和动脉粥样硬化条件对功能的影响，这些染色质的变化通过促进体外和小鼠模型中VSMC和单核细胞之间的异型相互作用而导致血管功能障碍。 我们的初步结果揭示了迄今为止尚未探索的糖尿病刺激作用的新的血管机制。我们在这项提案中最先进的转录本方法可以显著推动该领域的发展，并通过揭开糖尿病持续血管并发症的新因素和机制而产生关键影响。完成的结果可能为开发迫切需要的新的和新的治疗方法提供战略，以降低糖尿病心血管疾病的发病率和死亡率。

DESCRIPTION (provided by applicant): Cardiovascular complications such as hypertension and atherosclerosis are highly prevalent in the diabetic population. Evidence supports a role for genes associated vascular inflammation in the pathogenesis of diabetic vascular disease. However, very little is known about the subtle molecular mechanisms or key nuclear factors involved in regulating these genes in vascular smooth muscle cells (VSMC), or their in vivo functional relevance. Recent studies show that diabetic vascular complications continue to progress in patients who have not had prior intensive glycemic control. Based on our new supportive data, we propose that novel "epigenetic" chromatin remodeling mechanisms of gene regulation in vascular cells may mediate this "diabetic memory" phenomenon. Our data also demonstrate that genes activated in VSMC under diabetic conditions in vitro or vivo via these nuclear mechanisms can lead to close interactions between VSMC and monocytes in the subendothelial space. Our central hypothesis is that diabetic stimuli such as high glucose (HG) and advanced glycation end products (AGEs) induce inflammatory chemokines and cytokines in VSMC via novel in vivo nuclear chromatin remodeling mechanisms. These factors can induce vascular inflammation, VSMC-monocyte interactions and phenotypic changes and thereby lead to accelerated cardiovascular disease. Specific Aim 1 is to examine the nuclear transcriptomic mechanisms by which diabetic stimuli lead to chemotactic gene expression in VSMC. Here we will determine the nuclear interplay between NF-kB transcription factor and key chromatin factors using gain- and loss-of-function approaches. Specific Aim 2 is to evaluate the in vivo relevance of these nuclear mechanisms and factors in VSMC and aortas derived from mouse models of diabetes. Here we will determine the potential association with hyperglycemic memory, sustained gene expression and activation observed in these diabetic cells. Specific Aims 3 and 4 are to determine the functional impact of diabetic and atherosclerotic conditions, and these chromatin changes in leading to vascular dysfunction by promoting heterotypic interactions between VSMC and monocytes in vitro and in the aortas of mouse models. Our preliminary results have uncovered novel hitherto unexplored vascular mechanisms of action of diabetic stimuli. Our state-of-the-art transcriptomic approaches in this proposal could significantly advance the field and make a key impact by unraveling new factors and mechanisms underlying the sustained vascular complications of diabetes. The completed results could provide strategies for the development of sorely needed newer and novel therapies to reduce the morbidity and mortality of diabetic cardiovascular disease.