ZMPSTE24, HIV treatment regimens, and atherosclerotic heart disease

 描述（由申请人提供）：我们的多机构团队将研究HIV蛋白酶抑制剂对ZMPSTE 24的抑制作用，以及由此产生的法尼基-前核层蛋白A的积累作为HIV-PI治疗患者中“代谢综合征”和动脉粥样硬化性心血管疾病的机制。该拨款提案是为了回应关于艾滋病患者心脏病机制的“申请请求”（RFA-HL-14-024）而提交的。我们的团队热衷于响应RFA，因为我们在心脏病学、HIV药物、脂质代谢、动脉粥样硬化和核纤层蛋白方面拥有集体专业知识。此外，该RFA为我们提供了一个追求我们自己的目标之一的机会--常用的HIV-PI（例如，阿扎那韦、利托那韦、洛匹那韦）抑制ZMPSTE 24并导致法尼基-前核纤层蛋白A在细胞和组织中的积累。这一发现值得注意，因为与前层蛋白A积累相关的遗传综合征（例如，Hutchinson-Gilford早衰综合征）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。没有任何一个研究小组能够对所有潜在的机制采取后续行动。我们的团队决定专注于深入研究HIV-PI，ZMPSTE 24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，一些绊脚石减缓了对HIV-PIs，ZMPSTE 24抑制和心脏病之间联系的理解。首先，缺乏特异性的前层蛋白A抗体使得难以在动物模型或HIV患者的细胞和组织中进行严格的研究。我们实验室最近开发的一组针对前层蛋白A的单克隆抗体将非常有助于克服这一障碍。其次，前层蛋白A的积累和动脉粥样硬化形成之间的联系知之甚少。动脉壁中对前层蛋白A毒性敏感的细胞以及与动脉粥样硬化发生的联系尚不清楚。为了克服这一障碍，我们已经创建了Zmpste 24的条件性敲除等位基因。第三，HIV-PI抑制ZMPSTE 24的机制尚不清楚。然而，克服这一障碍现在是非常可行的，因为我们的合作者Elisabeth Carpenter博士最近解决了人ZMPSTE 24的结构，单独和与前层蛋白A肽底物复合。我们有三个具体目标。第一个是研究HIV-PI对培养细胞系、小鼠模型以及HIV患者的细胞和组织中的前层蛋白A加工的影响。第二个是确定，与组织特异性Zmpste 24基因敲除小鼠，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Carpenter博士一起研究ZMPSTE 24催化的机制以及HIV-PI如何阻断ZMPSTE 24活性。我们对这三个目标感到兴奋，并准备好了所有的专业知识，试剂，技术和专家合作者来开展我们提出的研究。我们希望我们的研究将对艾滋病患者心脏病的机制产生新的见解。

 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.