Anti-atherogenic and anti-inflammatory role of Bone Morphogenic Protein Receptor II

项目摘要 动脉粥样硬化是一种具有多种潜在代谢和身体危险因素的炎症性疾病 包括干扰流（D流）、高胆固醇血症、高血压和糖尿病。然而，机制 这些致动脉粥样硬化的危险因素协同作用，导致动脉粥样硬化的发生和发展 还不清楚最近，我们发现BMP受体II（BMPR 2）作为抗肿瘤的抗肿瘤因子发挥着意想不到的作用。 炎症和抗动脉粥样硬化蛋白。我们发现BMPR 2的表达是 随着人类冠状动脉中动脉粥样硬化的进展而逐渐丧失。我们还发现，多个亲- 致动脉粥样硬化刺激[d-血流、血管紧张素II（Ang II）、高胆固醇血症和TNFα]， 下调内皮细胞BMPR 2的表达，而抗动脉粥样硬化刺激，如稳定血流（s-flow） 上调其在体内和体外的表达。这表明，可能存在一种共同的机制， 哪些促动脉粥样硬化因子下调BMPR 2表达， 恢复其表达可能是预防和治疗动脉粥样硬化的新途径。这 应用程序旨在解决这些问题，以开发一种新的治疗策略，以防止损失 BMPR 2的表达以及研究其诱导内皮细胞增殖的后续机制。 炎症新出现的证据表明，BMPR 2的表达可以通过microRNA调节， 尽管它们在炎症和动脉粥样硬化中的作用尚不清楚。我们基于miRNA的初步研究 从经受d-流动（通过部分颈动脉结扎）或Ang II的小鼠动脉获得的阵列已经鉴定了6个 miRNAs（miR-17、-21、-25、-93、-106和-181）作为潜在的促动脉粥样硬化miRNAs（athero-miRs）， 直接针对BMPR 2。目前抑制miRNAs的方法如抗miRs影响其靶基因 （~数百）不加区别地，潜在地引起期望的和不期望的效果。在这里，我们将使用一本小说 使用“靶点阻断剂”的方法，以避免目前方法的滥杀滥伤作用。我们 最重要的假设是促动脉粥样硬化因子增加了动脉粥样硬化miR的内皮表达， 直接下调BMPR 2，进而引发内皮炎症和动脉粥样硬化。我们进一步 提出BR 2-TSB将保护BMPR 2免受动脉粥样硬化miR的影响，保留其组成性抗-miR-1， 炎症和抗动脉粥样硬化作用，而不影响其他动脉粥样硬化-miR靶点。这一假设将是 使用两种促动脉粥样硬化条件（d-flow和Ang II）在体外（内皮细胞[EC]）和体内进行测试。目的 1将确定动脉粥样硬化miR对体外EC中d-flow和Ang II表达BMPR 2的功能作用 和体内。在目标2中，我们将设计BR 2-TSB以防止BMPR 2通过动脉粥样硬化-miR在EC中下调。 体外和体内。目的3将确定BR 2-TSB在ApoE-/-小鼠动脉粥样硬化中的治疗潜力。 目的4将检验BMPR 2的缺失导致BMPR 2尾部结合蛋白的“释放”的假设， 导致内皮炎症和动脉粥样硬化。

PROJECT SUMMARY Atherosclerosis is an inflammatory disease with multiple underlying metabolic and physical risk factors including disturbed flow (d-flow), hypercholesterolemia, hypertension and diabetes. However, the mechanisms by which these pro-atherogenic risk factors synergize, leading to initiation and progression of atherosclerosis are still unclear. Recently, we found that BMP Receptor II (BMPR2) plays an unexpected role as an anti- inflammatory and anti-atherogenic protein in endothelial cells. We found that BMPR2 expression was progressively lost as atherosclerosis advances in human coronary arteries. We also found that multiple pro- atherogenic stimuli [d-flow, angiotensin II (Ang II), hypercholesterolemia and TNFα], significantly downregulated BMPR2 expression in endothelium, while anti-atherogenic stimuli such as stable flow (s-flow) upregulated its expression in vivo and in vitro. This suggests that there may be a common mechanism by which pro-atherogenic factors downregulate BMPR2 expression and that protecting it from risk factors or restoring its expression could be a novel avenue for prevention and treatment of atherosclerosis. This application is designed to address these questions to develop a novel therapeutic strategy to prevent the loss of BMPR2 expression as well as to investigate the subsequent mechanism by which it induces endothelial inflammation. Emerging evidence demonstrates that BMPR2 expression can be regulated by microRNAs, although their role in inflammation and atherosclerosis is unclear. Our preliminary studies based on miRNA arrays obtained from mouse arteries subjected to d-flow (by partial carotid ligation) or Ang II have identified 6 miRNAs (miR-17, -21, -25, -93, -106 and -181) as potential pro-atherogenic miRNAs (athero-miRs) that could directly target BMPR2. Current methods to inhibit miRNAs such as anti-miRs affect their target genes (~hundreds) indiscriminately, potentially causing both desired and unwanted effects. Here, we will use a novel approach using “target site blockers (TSBs)” to avoid the indiscriminate effects of the current methods. Our overarching hypothesis is that pro-atherogenic factors increase endothelial expression of the athero-miRs that directly downregulate BMPR2, which in turn triggers endothelial inflammation and atherosclerosis. We further propose that BR2-TSBs would protect BMPR2 from the athero-miRs, preserving its constitutive anti- inflammatory and anti-atherogenic role without affecting other athero-miR targets. This hypothesis will be tested using two pro-atherogenic conditions (d-flow and Ang II) in vitro (endothelial cells [ECs]) and in vivo. Aim 1 will determine the functional role of athero-miRs on BMPR2 expression by d-flow and Ang II in ECs in vitro and in vivo. In Aim 2, we will design BR2-TSBs to prevent BMPR2 downregulation by athero-miRs in ECs in vitro and in vivo. Aim 3 will determine the therapeutic potential of BR2-TSBs in atherosclerosis in ApoE-/- mice. Aim 4 will test the hypothesis that loss of BMPR2 leads to “unleashing” of BMPR2 tail-binding proteins, resulting in endothelial inflammation and atherosclerosis.