Adenylyl Cyclase and Cardiac Interstitium

心脏纤维化是心脏损伤的病理后果，可表现为局限性瘢痕或 更多的弥漫性间质纤维化。导致心脏纤维化的细胞是心脏成纤维细胞，它 在数量上是心脏中最普遍的细胞。心脏成纤维细胞受激素调节，许多 它们通过质膜受体发挥作用，包括那些与异三聚体G蛋白和G蛋白相连的受体- 受管制效应器。一种这样的效应器，腺酰环化酶，催化从 并是这项提案的重点。环磷酸腺苷具有抗纤维化作用，包括抑制 静息状态下的心脏成纤维细胞向促纤维化的肌成纤维细胞转化。这项提案将考验几个 与环状AMP形成能力增加有关的假说，由增强表达产生 腺苷环化酶-6(AC-6)，以改变心脏成纤维细胞的生化和功能活性。研究将会是 使用心脏成纤维细胞的原代培养进行，此外还将使用动物 造成心脏纤维化的模型(大鼠和小鼠的血管紧张素输注)。实验的重点是AC-6 强调其与近端和远端信号组件的分隔以及影响 通过几个表型特征评估，AC-6在纤维化反应中的表达增加。 这些结果应该提供有关心脏靶向治疗的可能性的原则证明数据。 通过基因转移AC-6和潜在的其他AC亚型诱导成纤维细胞。AC-6的目标很可能是 冠状动脉内注射重组病毒载体(项目1)将增加心肌细胞AC-6 在成纤维细胞中表达。项目2的一般假设是AC-6在心脏组织中的表达增加 成纤维细胞将改变纤维化反应，有利于修改心脏重塑以改善心脏 在衰竭的心脏中发挥作用。

Cardiac fibrosis, a pathological consequence of cardiac injury, can be manifest either as localized scar or more diffuse interstitial fibrosis. The cells responsible for cardiac fibrosis are cardiac fibroblasts, which numerically are the most prevalent cells in the heart. Cardiac fibroblasts are regulated by hormones, many of which act via plasma membrane receptors, including ones that are linked to heterotrimeric G proteins and G-protein- regulated effectors. One such effector, adenylyl cyclase, catalyzes the formation of cyclic AMP from ATP and is the focus of this proposal. Cyclic AMP has anti-fibrotic actions that include inhibition of the transformation of "resting" cardiac fibroblasts to pro-fibrogenic myofibroblasts. This proposal will test several hypotheses related to the ability of increased cyclic AMP formation, produced by enhanced expression of adenylyl cyclase-6 (AC-6), to alter biochemical and functional activities of cardiac fibroblasts. Studies will be conducted using primary cultures of cardiac fibroblasts and, in addition, will involve the use of an animal model (angiotensin infusion in rats and mice) that produces cardiac fibrosis. The experiments focus on AC-6 with an emphasis on its compartmentation with proximal and distal signaling components as well as impact of increased AC-6 expression on the fibrotic response, as assessed by several phenotypic characteristics. The results should provide proof-of-principle data regarding the potential for therapeutic targeting of cardiac fibroblasts by gene transfer with AC-6 and potentially other AC isoforms. It is likely that targeting of AC-6 to cardiac myocytes via intracoronary delivery of recombinant viral vectors (Project 1) will increase AC-6 expression in fibroblasts. The general hypothesis of Project 2 is that increased expression of AC-6 in cardiac fibroblasts will alter the fibrotic response and favorably modify cardiac remodeling to improve cardiac function in the failing heart.