ZMPSTE24, HIV treatment regimens, and atherosclerotic heart disease

 描述(由申请者提供)：我们的多机构团队将研究艾滋病毒-蛋白酶抑制剂对ZMPSTE24的抑制以及由此导致的法尼基-前层蛋白A的积累，以此作为HIV-PI治疗患者的“代谢综合征”和动脉粥样硬化性心血管疾病的机制。这项赠款提案是应一份关于艾滋病毒患者心脏病机制的“申请申请”(RFA-HL-14-024)提交的。我们的团队热衷于对这种RFA做出反应，因为我们在心脏病学、艾滋病毒药物、脂代谢、动脉粥样硬化和核板层方面拥有共同的专业知识。此外，这种RFA为我们提供了一个机会来追求我们自己的发现之一--常用的HIV-PI(例如，阿扎那韦、利托那韦、洛比那韦)抑制ZMPSTE24并导致法尼基-前层素A在细胞和组织中积累。这一发现值得注意，因为与Prelamin A积聚相关的遗传综合征(例如，Hutchinson-Gilford早衰症)会导致严重的动脉粥样硬化性心脏病。我们充分认识到，艾滋病毒患者的心脏病是多因素的，并受到几类药物的影响。没有一个单独的研究小组可能对所有可能的机制进行后续研究。我们的团队已经决定集中和更深入地研究HIV-PI、ZMPSTE24活性降低、法尼基-前层蛋白A积累和心脏病之间的联系。在过去的几年里，几个绊脚石减缓了理解HIV-PI、ZMPSTE24抑制和心脏病之间的联系的进展。首先，缺乏特定的前层蛋白A抗体，这使得在动物模型中或在艾滋病毒患者的细胞和组织中进行严格的研究变得困难。我们实验室最近开发的一组抗前层蛋白A的单抗将对克服这一障碍非常有帮助。其次，前层蛋白A积累和动脉粥样硬化形成之间的联系还知之甚少。动脉壁中对Prelamin A毒性敏感的细胞--以及与动脉粥样硬化的联系--尚不清楚。为了克服这一障碍，我们为Zmpste24创造了一个条件基因敲除等位基因。第三，HIV-PI抑制ZMPSTE24的机制尚不清楚。然而，克服这一障碍现在是相当可行的，因为我们的合作者伊丽莎白·卡彭特博士最近解决了人类ZMPSTE24的结构，它单独存在，并与Prelamin A肽底物复合。我们有三个具体目标。第一个是研究HIV-PI对培养的细胞系、小鼠模型以及HIV患者的细胞和组织中前层蛋白A加工的影响。第二个是通过组织特异性Zmpste24基因敲除小鼠，确定前层蛋白A的积累如何影响不同类型的动脉壁细胞，并导致动脉粥样硬化。第三个是与卡彭特博士一起研究ZMPSTE24的催化机制，以及HIV-PI如何阻断ZMPSTE24的活性。我们对这三个目标感到兴奋，并准备好--拥有所有的专业知识、试剂、技术和专家合作者--来开展我们提议的研究。我们期待我们的研究将对HIV患者的心脏病机制产生新的见解。

 DESCRIPTION (provided by applicant): Our multi-institutional team will investigate ZMPSTE24 inhibition by HIV-protease inhibitors and the resulting accumulation of farnesyl-prelamin A as a mechanism for "metabolic syndrome" and atherosclerotic cardiovascular disease in HIV-PI-treated patients. This grant proposal is submitted in response to a "Request for Applications" (RFA-HL-14-024) on mechanisms of heart disease in HIV patients. Our team was enthusiastic about responding to this RFA because we have collective expertise in cardiology, HIV medicine, lipid metabolism, atherogenesis, and nuclear lamins. Also, this RFA provides an opportunity for us to pursue one of our own discoveries-that commonly used HIV-PIs (e.g., atazanavir, ritonavir, lopinavir) inhibit ZMPSTE24 and lead to an accumulation of farnesyl-prelamin A in cells and tissues. This discovery is noteworthy because genetic syndromes associated with an accumulation of prelamin A (e.g., Hutchinson-Gilford progeria syndrome) lead to severe atherosclerotic heart disease. We fully appreciate that heart disease in HIV patients is multifactorial and influenced by several classes of drugs. No single research group could possibly follow-up on all of the potential mechanisms. Our team has decided to focus and to dig deeper into the connection between HIV-PIs, reduced ZMPSTE24 activity, farnesyl-prelamin A accumulation, and heart disease. Over the past few years, several stumbling blocks have slowed progress in understanding the connection between HIV-PIs, ZMPSTE24 inhibition, and heart disease. First, a paucity of specific prelamin A antibodies has made it difficult to perform rigorous research in animal models or with the cells and tissues of HIV patients. Our laboratory's recent development of a panel of monoclonal antibodies against prelamin A will be very helpful in overcoming that obstacle. Second, the link between prelamin A accumulation and atherogenesis is poorly understood. The cells in the arterial wall that are susceptible to prelamin A toxicity-and the link to atherogenesis-are not understood. To overcome that obstacle, we have created a conditional knockout allele for Zmpste24. Third, the mechanisms by which HIV-PIs inhibit ZMPSTE24 are not known. However, overcoming that obstacle is now quite feasible because the structure for human ZMPSTE24, alone and complexed to a prelamin A peptide substrate, was recently solved by our collaborator, Dr. Elisabeth Carpenter. We have three Specific Aims. The first is to investigate the impact of HIV-PIs on prelamin A processing in cultured cell lines, in mouse models, and in the cells and tissues of HIV patients. The second is to determine, with tissue-specific Zmpste24 knockout mice, how prelamin A accumulation affects different cell types of the arterial wall and leads to atherogenesis. The third is to investigate, with Dr. Carpenter, mechanisms for ZMPSTE24 catalysis and how HIV-PIs block ZMPSTE24 activity. We are excited by all three Aims and are poised-with all of the expertise, reagents, techniques, and expert collaborators-to carry out our proposed studies. We expect that our studies will yield fresh insights into mechanisms of heart disease in HIV patients.