Actin and focal adhesion remodeling as therapeutic targets in cardiovascular disease

最近的流行病学研究表明，人的近端主动脉僵硬随着年龄和年龄的增加而增加 是心血管不良的早期和独立的生物标志物，并可能促成其发生。 结果包括肾衰竭、高血压和阿尔茨海默病相关的痴呆症。正常的 近端主动脉的灵活性是保护下游小血管的关键“减震器”。 来自心脏产生的高脉搏压力。我们在已发表的研究中表明， 血管平滑肌细胞(VSMC)调节多达一半的总主动脉僵硬和衰老所致的损失 VSMC细胞骨架的调节会导致主动脉执行这一休克的能力受损 吸收功能。我们实验室的一项重大进展是证明了大脑皮层非肌肉 肌动蛋白细胞骨架及其与局部粘连和细胞外基质的联系是一种特别动态的 也是VSMC细胞骨架的重要组成部分。该计划的广泛目标是测试以下概念 超声靶向、细胞诱骗多肽和小分子抑制剂均可用于探查 并逆转衰老所致的VSMC细胞骨架功能障碍。我们将使用手机 本实验室开发的诱饵多肽和重组蛋白，以及用于比较的小分子 抑制剂，以验证以下假设：老年小鼠的体外主动脉僵硬可以通过以下方法降低 针对VSMC细胞骨架的机制。我们将挖掘蛋白质序列数据库以识别 VSMC特有的序列。针对这些序列的合成诱饵构建将测试概念验证 多肽方法的选择性和有效性。我们将使用生物力学，磁性镊子， 邻近连接分析、肌动蛋白聚合试验和免疫沉淀以确定其作用机制 诱饵的行动。我们将与我们纳米科学中心的泰龙·波特合作，测试这一假说 微泡包装细胞诱饵和超声波介导的释放将允许局部化， 有效诱饵的组织特异性定向递送。我们将测试一种假设，即组织靶向诱饵 可在小鼠体内显著降低PWV，体内慢性治疗可防止3种阴性结果 与增龄引起的主动脉僵硬增加相关：脑血管病变、高血压和肾脏 损坏。因此，我们提出了一种高度创新的研究策略来攻击衰老诱导的大脑 血管肌动蛋白细胞骨架及其与局灶性粘连的联系。这种方法，无论结果如何，都将 回答有关主动脉僵硬及其与年龄的血管功能的关系的主要问题。如果成功， 这种方法有可能预防或逆转一系列与衰老相关的心血管疾病。

Recent epidemiological studies have made clear that human proximal aortic stiffness increases with age and is an early and independent biomarker of, and probable contributor to, subsequent adverse cardiovascular outcomes including kidney failure, hypertension and Alzheimer's Disease-related dementia. The normal flexibility of the proximal aorta functions as a critical “shock absorber” to protect small downstream vessels from the high pulses of pressure generated by the heart. We have shown in published studies that the vascular smooth muscle cell (VSMC) regulates up to half of total aortic stiffness and that aging-induced loss of regulation of the VSMC cytoskeleton leads to impairment of the ability of the aorta to perform this shock absorption function. A major advance from our lab has been the demonstration that the cortical nonmuscle actin cytoskeleton and its linkages to focal adhesions and the extracellular matrix are a particularly dynamic and important part of the VSMC cytoskeleton. The broad goal of this program is to test the concept that ultrasound-targeted, cell permeant decoy peptides and small molecule inhibitors can be used both to probe function and to reverse aging-induced malfunction of the VSMC cytoskeleton. We will use cell permeant decoy peptides and recombinant proteins developed by our lab, and for comparison, small molecule inhibitors, to test the hypothesis that ex vivo stiffness of aortas from aged mice can be decreased by mechanisms targeted to the VSMC cytoskeleton. We will mine protein sequence data bases to identify VSMC-specific sequences. Synthetic decoy constructs targeting these sequences will test a proof of concept for the selectivity and efficacy of the peptide approach. We will use biomechanics, magnetic tweezers, proximity ligation analysis, actin polymerization assays and immunoprecipitation to confirm the mechanism of action of decoys. We will test, in collaboration with Tyrone Porter of our Nanoscience Center, the hypothesis that microbubble-packaging of cell-permeant decoys and ultrasound-mediated release will allow localized, tissue-specific targeted delivery of effective decoys. We will test the hypothesis that tissue-targeted decoys can acutely reduce PWV in vivo in mice and that chronic in vivo treatment can prevent 3 negative outcomes associated with aging-induced increased aortic stiffness: brain vascular lesions, hypertension and renal damage. Hence, we propose a highly innovative research strategy to attack aging-induced alterations in the vascular actin cytoskeleton and its linkage to focal adhesions. This approach, no matter the outcome, will answer major questions about aortic stiffness and its relationship to vascular function with age. If successful, this approach has the potential to prevent or reverse a host of aging-associated cardiovascular disorders.