Inhibitor ameliorates oxidative and proteolytic strees

内皮细胞内皮（EE）功能障碍和氧化基质在内皮和肌肉之间的积聚 是充血性心力衰竭（CHF）的标志。本项目的总体目标是了解 CHF中氧化基质蓄积和EE功能障碍的机制。以前的研究表明， 氧化应激诱导、内皮细胞密度降低、基质激活 金属蛋白酶（MMP）、胶原溶解和金属蛋白酶心脏组织抑制剂的抑制 （CIMP），以瑞士法郎计。该提议的新奇在于，在所有已知的金属蛋白酶组织抑制剂中， TIMP-4（即CIMP）在心脏中高度表达。本提案的目的是测试 中心假设，氧化基质积累和EE功能障碍是由于MMP水平升高 活性和胶原溶解。这些水平与EE一氧化氮和CIMP水平降低有关 在反应活性氧（ROS）的水平增加，在延长的周期， 缺血/再灌注容量超负荷。CIMP水平的增加可保护EE免受氧化损伤， 蛋白水解应激我们将通过以下三个具体目标来检验中心假设： 确定CIMP是否通过增加EE一氧化氮浓度来降低氧化应激。血浆 在慢性容量超负荷中测量左心室一氧化氮、ROS和硝基酪氨酸水平 用和不用CIMP处理的动静脉瘘小鼠。2_确定CIMP蛋白是否转移 抑制胶原蛋白溶解。将通过原位酶谱法测量MMP活性。CIMP活性水平 将通过反向酶谱法测量。总胶原蛋白及其降解片段将通过 使用抗胶原抗体的蛋白质印迹分析。3--确定CIMP是否改善 内皮功能障碍心肌对乙酰胆碱、缓激肽和硝普钠的收缩反应 将在组织肌深中测量心脏环。这些研究将使我们能够确定CIMP是否 改善心脏对一氧化氮供体的反应查明参与控制 氧化和蛋白水解应激将有助于开发预防CHF的策略。

Endocardial endothelial (EE) dysfunction and accumulation of oxidized-matrix between endothelial and muscle are the hallmarks of congestive heart failure (CHF). The overall objective of this project is to understand the mechanism of oxidized-matrix accumulation and EE dysfunction in CHF. Previous studies have suggested an association between induction of oxidative stress, decrease in endothelial cell density, activation of matrix metalloproteinase (MMP), collagenolysis, and repression of cardiac tissue inhibitor of metalloproteinase (CIMP) in CHF. The novelty of this proposal is that among all known tissue inhibitors of metalloproteinase (TIMP), the TIMP-4 (i.e. CIMP) is highly expressed in the heart. The purpose of this proposal is to test a central hypothesis that oxidized-matrix accumulation and EE dysfunction are due to increased levels of MMP activity, and collagenolysis. These levels are associated with decreased levels of EE nitric oxide, and CIMP in response to increased levels of reactive oxygen species (ROS) during protracted cycles of ischemia/reperfusion in volume overload. The increased levels of CIMP protects EE against oxidative and proteolytic stresses. We will test the central hypothesis by the following three specific aims: L To determine whether CIMP decreases oxidative stress by increasing EE nitric oxide concentration. Plasma and left ventricle levels of nitric oxide, ROS, and nitrotyrosine will be measured in chronic volume overload arteriovenous fistula mice treated with and without CIMP. 2_ To determine whether CIMP protein transfer inhibits collagenolysis. MMP activity will be measured by in situ zymography. The levels of CIMP activity will be measured by reverse zymography. Total collagen and its degradation fragments will be measured by Western-blot analysis using anti-collagen antibody. 3-- To determine whether CIMP ameliorates endocardial endothelial dysfunction. Contractile responses to acetylcholine, bradykinin, and nitroprusside in cardiac rings will be measured in a tissue myobath. These studies will enable us to determine whether CIMP improves the hearts response to nitric oxide donors. Identification of major players involved in the control of oxidative and proteolytic stresses will help to develop strategies to prevent CHF.