Sirtuin 3 Inactivation and SOD2 Acetylation in Vascular Dysfunction and Hypertension

项目摘要 血管功能障碍在高血压和心血管疾病中起关键作用 线粒体脱乙酰酶SIRT3，但目前还没有针对线粒体的治疗方法。SIRT3失活诱导 线粒体超氧化物歧化酶(SOD2)抑制和脂肪酸代谢受损导致线粒体 氧化应激和有害脂质过氧化产物的形成，异丙肾上腺素(Isolg)。我们建议一个馈送- SIRT3失活和线粒体等位基因之间的前向循环促进血管功能障碍和高血压。 我们开发了一种新的线粒体靶向的同工酶清除剂mito2HOBA，它可以保护SIRT3的活性并减弱 高血压。在这项提案中，我们将通过定义线粒体等位基因在线粒体中的新作用来推进这项研究 SIRT3失活和血管功能障碍，我们将建立靶向线粒体的治疗潜力 Isolg。我们的总体目标是确定islg介导的SIRT3失活的具体机制并直接测试 利用新的转基因小鼠、新的线粒体靶向靶向线粒体等位基因的治疗潜力 药物，以及来自高血压患者的血管组织。我们将致力于实现以下目标： 目的1.验证内皮细胞SIRT3失活导致可预防的内皮功能障碍的假设 通过靶向线粒体等位基因。为了达到这个目的，我们将研究内皮细胞的病理生理作用。 内皮特异性SIRT3缺失(EcSirt3KO)和野生型SIRT3损伤和线粒体等位基因 雄性和雌性小鼠。我们将确定SIRT3失活和线粒体等位基因在内皮细胞中的作用 炎症、细胞衰老、内皮屏障破坏和松弛受损。 目的2.验证SIRT3失活导致血管功能障碍的假说，并阻断 线粒体等密度脂蛋白改善血管功能。我们将研究平滑肌SIRT3损伤的作用 在SIRT3耗竭(SmcSirt3KO)小鼠中。SOD2-K68乙酰化与代谢的特殊作用 功能障碍将在可用的SOD2去乙酰化模拟SOD2K68R和SIRT3-/-SODK68R小鼠身上进行测试。这个 线粒体等位基因在平滑肌肥大、炎症和主动脉重塑中的作用将被明确。 目的3.在小鼠模型中确定靶向SIRT3失活和线粒体等位基因的治疗潜力 以及来自高血压患者的人体血管组织。我们将测试(A)是否使用新的治疗方法 线粒体靶向等LG清除剂，如mito2HOBA，在高血压发病后增加SIRT3 在小鼠模型中的活性和改善血管功能，以及(B)是否靶向血管中的线粒体等位基因 来自高血压受试者的体外组织减少炎症，提高SIRT3活性和松弛。 我们处于进行这些跨学科研究的理想位置。我们开发了新的SIRT3转基因小鼠 模型和针对线粒体的治疗。我们可以接触到人类血管组织和独特的专业知识 在氧化应激、人类血管研究和高血压方面。我们的数据支持这一新的血管通路 这项工作有可能对新的临床治疗方法的开发产生重大影响。

Project Summary Vascular dysfunction plays a key role in hypertension and cardiovascular disease associated with inactivation of mitochondrial deacetylase Sirt3, but mitochondria-targeted treatments are not available. Sirt3 inactivation induces inhibition of mitochondrial superoxide dismutase (SOD2) and impairs fatty acid metabolism leading to mitochondrial oxidative stress and formation of harmful lipid peroxidation products, isolevuglandins (isoLG). We suggest that a feed- forward cycle between Sirt3 inactivation and mitochondrial isoLG promotes vascular dysfunction and hypertension. We developed new mitochondria-targeted isoLG scavenger, mito2HOBA, which protects Sirt3 activity and attenuates hypertension. In this proposal, we will advance this research by defining the novel role of mitochondrial isoLG in Sirt3 inactivation and vascular dysfunction, and we will establish the therapeutic potential of targeting mitochondrial isoLG. Our overall objective is to define the specific mechanism of isoLG-mediated Sirt3 inactivation and directly test the therapeutic potential of targeting mitochondrial isoLG using new transgenic mice, new mitochondria-targeted drugs, and vascular tissue from patients with essential hypertension. We will pursue the following aims: AIM 1.Test the hypothesis that inactivation of endothelial Sirt3 induces endothelial dysfunction which is prevented by targeting mitochondrial isoLG. In this aim we will examine the pathophysiological role of endothelial Sirt3 impairment and mitochondrial isoLG in endothelium specific Sirt3 depleted (EcSirt3KO) and wild-type male and female mice. We will define the role of Sirt3 inactivation and mitochondrial isoLG in endothelial inflammation, cell senescence, endothelial barrier disruption, and impaired relaxation. AIM 2.Test the hypothesis that inactivation of smooth muscle Sirt3 induces vascular dysfunction, and blocking mitochondrial isoLG improves vascular function. We will study the role of smooth muscle Sirt3 impairment in smooth muscle Sirt3 depleted (SmcSirt3KO) mice. The specific roles of SOD2-K68 acetylation and metabolic dysfunction will be tested in available SOD2-deacetylation mimetic SOD2K68R and Sirt3-/--SODK68R mice. The role of mitochondrial isoLG in smooth muscle hypertrophy, inflammation and aortic remodeling will be defined. AIM 3. Determine the therapeutic potential of targeting Sirt3 inactivation and mitochondrial isoLG in mouse models and human vascular tissue from patients with essential hypertension. We will test (A) if treatment with novel mitochondria-targeted isoLG scavengers, such as mito2HOBA, after onset of hypertension increases Sirt3 activity and improves vascular function in mouse models, and (B) if targeting mitochondrial isoLG in vascular tissues from hypertensive human subjects ex vivo reduces inflammation, improves Sirt3 activity, and relaxation. We are in an ideal position to perform these interdisciplinary studies. We developed new Sirt3 transgenic mouse models and mitochondria-targeted treatments. We have access to human vascular tissue and unique expertise in oxidative stress, human vascular studies and hypertension. Our data support this novel pathway in vascular dysfunction, and this work has the potential to make a major impact on the development of new clinical treatments.