Mechanisms of Microvascular Remodeling Progression

微血管重塑进展机制

• 批准号: 9198801
• 负责人: Luis A Martinez-Lemus
• 金额: $ 37.78万
• 依托单位: UNIVERSITY OF MISSOURI-COLUMBIA
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9198801
• 关键词: Actins; Animal Model; Animals; Arteries; Blood Vessels; Caliber; Cardiovascular Diseases; Cardiovascular system; Cause of Death; Cells; Clinical; Cytoskeleton; Data; Development; Disease Management; Ear; Elastin; Event; Excision; Extracellular Matrix; Gelatinase A; Goals; Hypertension; Individual; Intervention; Knowledge; LIM Domain Kinase 1; Lead; Life; MMP14 gene; Matrix Metalloproteinases; Measures; Modification; Molecular; Muscle Cells; Myocardial Infarction; Outcome; Patients; Peptides; Pharmacology; Prevalence; Process; Production; Proteins; Public Health; Publications; Reporting; Research; Resistance; Resistance Process; Rho-associated kinase; Risk; Site; Stimulus; Stress Fibers; Stroke; Structure; Subcellular structure; Techniques; Technology; Testing; Therapeutic; Tissues; United States; Vascular Smooth Muscle; Vascular remodeling; base; cofilin; crosslink; insight; intravital microscopy; normotensive; novel strategies; polymerization; prevent; public health relevance; transglutaminase 2; vasoconstriction

 DESCRIPTION (provided by applicant): Vascular remodeling is an adaptive mechanism for long-term modification of vascular diameter. In hypertension, inward remodeling, that is, the structural reduction of the lumen diameter in resistance vessels, is associated with an increased risk for myocardial infarction and stroke. However, despite its prevalence and clinical importance, the mechanisms that control the inward remodeling process remain largely unknown. Our goal here is to identify mechanisms in the inward remodeling process of the resistance vasculature that may be intervened with novel strategies to prevent, stop or reverse the remodeling process, and consequently diminish the life-threatening cardiovascular events associated with it. Current publications and our own preliminary data indicate that tissue-type transglutaminase (TG2), LIM kinase (LIMK), and matrix metalloproteinase-2 (MMP2) within vascular smooth muscle cells (VSMC) are involved in the remodeling process. Therefore, as we and others have determined that inwardly remodeled resistance vessels have actin cytoskeletal structures that reduce their passive diameters and extracellular matrix (ECM) features characterized by a reduction in the number and size of fenestrae in the internal elastic lamina (IEL): Our hypothesis is that during the early stages of the inward remodeling process in resistance vessels, prolonged vasoconstriction leads to formation of permanent VSMC cytoskeletal structures via the intracellular activity of TG2 and LIM kinase, which in turn stimulate the production of MMP2 and the modification of the ECM, in particular the IEL. We will test our hypothesis in VSMC, isolated resistance arteries and a whole animal model of hypertension. Cells and tissues will come from animals, as well as from normotensive and hypertensive individuals. The expression and activity of the remodeling components tested in our hypotheses will be modulated using pharmacological and molecular means. Experimental outcomes will be measured using traditional and leading-edge techniques in protein and enzymatic activity analyses, as well as, atomic force, multiphoton, and long-term intravital microscopy. Our specific aims will test the hypotheses that: 1) Intracellular TG2 activates RhoA, Rho kinase and LIMK to phosphorylate and inactivate cofilin to favor formation of actin networks and stress-fibers, with TG2 further crosslinking actin structures to make them more persistent; and 2) that LIMK activates MMP14 and leads to expression/secretion of MMP2 from VSMC. Then MMP2 through its elastolytic actions generates elastin peptides that activate VSMC to produce more elastin. This new elastin is incorporated in the IEL and reduces the size and number of fenestrae in the IEL. We expect this study will provide new insights on how cytoskeletal and IEL structures of resistance arteries are modified in hypertension. This knowledge should have a positive impact on strategies for preventing and treating hypertension, and the management of diseases associated with vascular remodeling.

 描述（由申请人提供）：血管重塑是血管直径长期改变的适应性机制，在高血压中，向内重塑，即阻力血管管腔直径的结构性减小，与心肌风险增加相关。然而，尽管其普遍存在且具有临床重要性，但控制向内重塑过程的机制仍然很大程度上未知，我们的目标是确定抵抗脉管系统的向内重塑过程中的机制。可以通过新策略进行干预，以预防、停止或逆转重塑过程，从而减少与之相关的危及生命的心血管事件。 ) 和血管平滑肌细胞 (VSMC) 内的基质金属蛋白酶 2 (MMP2) 参与重塑过程。因此，我们和其他人已经确定，向内重塑的阻力血管具有肌动蛋白细胞骨架结构。减少其被动直径和细胞外基质（ECM）特征，其特征是内弹性层（IEL）中窗孔的数量和尺寸减少：我们的假设是，在阻力血管向内重塑过程的早期阶段，长时间的血管收缩通过 TG2 和 LIM 激酶的细胞内活性导致永久性 VSMC 细胞骨架结构的形成，进而刺激 MMP2 的产生和 ECM（特别是 IEL）的修饰。将在 VSMC 中检验我们的假设，分离的阻力动脉和高血压的整个动物模型将来自动物以及血压正常和高血压个体。我们的假设中测试的重塑成分的表达和活性将受到调节。使用药理学和分子手段。实验结果将使用蛋白质和酶活性分析中的传统和前沿技术以及原子力、多光子和长期活体显微镜进行测试。假设：1) 细胞内 TG2 激活 RhoA、Rho 激酶和 LIMK，使肌动蛋白丝切蛋白磷酸化和失活，从而有利于肌动蛋白网络和应力纤维的形成，TG2 进一步交联肌动蛋白结构，使其更加持久；2) LIMK 激活 MMP14；并导致 VSMC 表达/分泌 MMP2，然后 MMP2 通过其弹力分解作用产生弹性蛋白。这种新的弹性蛋白被纳入 IEL 中，并减少了 IEL 中窗孔的大小和数量，我们预计这项研究将为高血压中阻力动脉的细胞骨架和 IEL 结构的改变提供新的见解。这些知识应该对预防和治疗高血压的策略以及与血管重塑相关的疾病的管理产生积极影响。