Disturbed flow-induced TERF2IP post-translational modifications and atherosclerosis.

血流紊乱诱导的 TERF2IP 翻译后修饰和动脉粥样硬化。

• 批准号: 9207134
• 负责人: Jun-Ichi Abe
• 金额: $ 51.09万
• 依托单位: UNIVERSITY OF TX MD ANDERSON CAN CTR
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-02-01 至 2020-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9207134
• 关键词: Aging; Aging-Related Process; Arterial Fatty Streak; Atherosclerosis; Attenuated; Blood Vessels; Cell Aging; Cell physiology; Complex; Cytosol; DNA Damage; DNA Repair; Development; Double Strand Break Repair; Embryo; Endothelial Cells; Functional disorder; Goals; Inflammation; Inflammatory; Inflammatory Response; Knock-out; Knockout Mice; Knowledge; Link; Mediating; Mus; Mutation; Nuclear; Nuclear Export; Pathogenesis; Pathology; Pathway interactions; Phosphorylation; Phosphorylation Site; Phosphotransferases; Play; Post-Translational Protein Processing; Proteins; Regulation; Role; Scheme; Signal Transduction; Study models; TERF2 gene; Telomere Shortening; Testing; Vascular Diseases; endothelial dysfunction; in vitro Model; in vivo; insight; mutant; novel therapeutic intervention; overexpression; prevent; protective effect; public health relevance; response; senescence; telomere

 DESCRIPTION (provided by applicant): Endothelial cell (EC) dysfunction and vasculopathy play a key role in pathogenesis of atherosclerosis (AS). In addition to EC inflammation, senescence (Sen) may play a role in EC dysfunction. Telomere (TL) shortening and dysfunction provokes EC Sen, which is associated with focalized plaque formation. Although it is well known that disturbed flow (d-flow) increases both EC inflammation and Sen, the exact mechanisms by which d-flow uniquely induces these two different EC pathologies and subsequent AS are poorly understood. To answer the question of how d-flow leads to EC inflammation and Sen simultaneously, we developed in vivo and in vitro models for studying signaling induced by d-flow and found unique roles for p90RSK kinase and telomeric repeat-binding factor 2 (TRF2)-interacting protein (TERF2IP) and TRF2 complex in this mechanism. The TERF2IP-TRF2 complex is known to be involved in regulation of double strand break (DSB) repair of DNA at TLs as a component of the shelterin complex and of NF-κB signaling outside in the cytosol. In our preliminary studies, we found that d-flow induced p90RSK activation and up-regulated TERF2IP S205 phosphorylation and K240 SUMOylation in ECs. These TERF2IP posttranslational modifications were mediated by p90RSK activation, and overexpression of a kinase-dead mutant of p90RSK (KD-p90RSK), a TERF2IP S205A phosphorylation mutant, or a TERF2IP K240R SUMOylation mutant inhibited d-flow-induced Sen and DNA damage in ECs. Our central hypothesis is that d-flow-induced EC p90RSK activation, which increases TERF2IP phosphorylation and SUMOylation, elicits TL dysfunction by modifying the function of the TERF2IP-TRF2 complex, leading to EC dysfunction and ultimately to AS. We propose the following 3 aims to identify the mechanisms of TERF2IP-dependent EC dysfunction. Aim 1 will test the hypothesis that TERF2IP phosphorylation causes nuclear export of the TERF2IP-TRF2 complex and subsequent TERF2IP SUMOylation reduces the TL protection activity of the complex. Aim 2 will investigate whether TERF2IP phosphorylation is crucial for up-regulating EC inflammation. In Aim 3, we will determine the role of the p90RSK-TERF2IP module in regulating EC function and AS plaque formation in vivo. Although the possible involvement of EC Sen in AS has been suggested, to our knowledge there has been no study on the role of shelterin complex in AS formation. The new knowledge on the pathways activated by d-flow that alter EC TL function will aid development of new therapeutic strategies for AS, especially by inhibiting p90RSK-mediated TERF2IP post- translational modifications.

 描述（由申请人提供）：内皮细胞（EC）功能障碍和血管病变在动脉粥样硬化（AS）的发病机制中发挥着关键作用除了EC炎症之外，衰老（Sen）也可能在EC端粒（TL）缩短中发挥作用。尽管众所周知，血流紊乱（d-flow）会增加 EC 炎症和 Sen，但其确切机制却与局灶性斑块形成有关。 d-flow 独特地诱导这两种不同的 EC 病理，但对随后的 AS 知之甚少。为了回答 d-flow 如何同时导致 EC 炎症和 Sen 的问题，我们开发了体内和体外模型来研究 d-flow 诱导的信号传导。并发现 p90RSK 激酶和端粒重复结合因子 2 (TRF2) 相互作用蛋白 (TERF2IP) 和 TRF2 复合物在此机制中的独特作用。 TERF2IP-TRF2 复合物是已知的。在我们的初步研究中，我们发现 d-flow 诱导 p90RSK 激活并参与 TL 处 DNA 双链断裂 (DSB) 修复的调节，作为庇护蛋白复合物的组成部分和细胞质外 NF-κB 信号传导。 EC 中 TERF2IP S205 磷酸化和 K240 SUMO 化上调这些 TERF2IP 翻译后修饰是由 p90RSK 激活和过表达介导的。 p90RSK (KD-p90RSK) 的激酶死亡突变体、TERF2IP S205A 磷酸化突变体或 TERF2IP K240R SUMOylation 突变体抑制 EC 中 d-flow 诱导的 Sen 和 DNA 损伤。 p90RSK 激活会增加 TERF2IP 磷酸化和 SUMOylation，从而引发 TL 功能障碍改变 TERF2IP-TRF2 复合物的功能，导致 EC 功能障碍并最终导致 AS。我们提出以下 3 个目标，旨在确定 TERF2IP 依赖​​性 EC 功能障碍的机制。目标 1 将检验 TERF2IP 磷酸化导致核输出的假设。 TERF2IP-TRF2 复合物和随后的 TERF2IP SUMOylation 会降低复合物的 TL 保护活性。目标 2 将研究 TERF2IP 是否会降低该复合物的 TL 保护活性。在目标 3 中，我们将确定 p90RSK-TERF2IP 模块在体内调节 EC 功能和 AS 斑块形成​​中的作用，尽管有人认为 EC Sen 可能参与 AS 中。据我们所知，目前还没有关于庇护蛋白复合物在 AS 形成中的作用的研究，关于 d-flow 激活的改变 EC TL 功能的途径的新知识将有助于开发新的 AS 治疗策略，特别是通过抑制。 p90RSK 介导的 TERF2IP 翻译后修饰。