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Targeting peptide Lv and its downstream signaling against ocular neovascularization

靶向肽 Lv 及其下游信号对抗眼部新生血管形成

基本信息

批准号：
10407598
负责人：
GLADYS Y KO
金额：
$ 21.62万
依托单位：
TEXAS A&M UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-06-01 至 2024-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10407598
关键词：
Age related macular degeneration Angiogenic Factor Angiogenic Peptides Animal Model Antibodies Binding Biological Assay Blindness Blood Vessels Blood flow Calcium Cell Proliferation Choroidal Neovascularization Chronic Clinical Data Development Disease Endothelial Cells Endothelial Growth Factors Receptor Endothelium Extravasation Family Future Genetic Goals In Vitro Incidence KDR gene Knock-out Knowledge L-Type Calcium Channels Lasers Lead Mediating Messenger RNA Mission Molecular Mus Muscle Cells Nitric Oxide Nitric Oxide Synthetase Inhibitor Oxygen Pathogenesis Pathologic Pathologic Neovascularization Patients Peptides Pharmacology Photoreceptors Pilot Projects Potassium Channel Prevention Property Recurrence Research Resistance Retina Retinal Detachment Retinal Diseases Role Sequence Homology Signal Transduction Smooth Muscle Testing Therapeutic Treatment Factor United States National Institutes of Health Vascular Diseases Vascular Endothelial Cell Vascular Endothelial Growth Factors Vascular Permeabilities Vasodilation Vasodilator Agents Veins angiogenesis arteriole combat in vivo member migration mouse model mutant neovascular neovascularization novel ocular angiogenesis ocular neovascularization proliferative diabetic retinopathy protein expression resistance mechanism side effect tool

项目摘要

Project Summary Anti-vascular endothelial growth factor (VEGF) therapies are widely used for treating ocular diseases with neovascularization, but nearly 30% of afflicted patients are non-responders to anti-VEGF agents. In addition, repetitive anti-VEGF treatments that are needed to block the recurring neovascularization often lead to unintended side-effects including retinal detachment and even blindness. Thus, searching for VEGF-independent angiogenic factors and unveiling their underlying mechanisms become an imperative clinical need to help combat the recurrence of neovascularization and the resistance to anti-VEGFs in these diseases. Peptide Lv is a newly discovered angiogenic peptide that is upregulated in the retinas of patients with early proliferative diabetic retinopathy (PDR) and of mice subjected to oxygen-induced retinopathy (OIR), featuring ocular pathological neovascularization. Although it has no sequence homology to members of the VEGF family and VEGF receptors (VEGFRs), peptide Lv promotes angiogenesis in vitro and in vivo. An antibody against peptide Lv, anti-Lv, not only dampens VEGF- elicited endothelial cell proliferation, it also effectively blocks pathological neovascularization in mice with OIR, as well as laser-induced choroidal neovascularization. Furthermore, peptide Lv not only cooperatively promotes VEGF-induced angiogenesis, but also elicits VEGF/VEGFR2/nitric oxide-independent vasodilation. Chronic vasodilation of existing vessels causes increased vascular permeability, stimulates angiogenesis, and promotes neovascularization. Vasodilators are associated with a ~70% increased incidence of early age-related macular degeneration (AMD). Thus, peptide Lv might be involved in the pathogenesis of PDR and wet AMD via promoting both VEGF/VEGFR2-dependent and -independent angiogenesis and vasodilation. However, the mechanistic role of peptide Lv in mediating VEGF-independent angiogenesis and vasodilation is completely unknown. Peptide Lv is able to augment the protein expression of intermediate conductance calcium-dependent potassium channels (IKCa) in cultured endothelial cells. Activation of K+ channels in the endothelium, especially IKCa, is important in angiogenesis that can be VEGF/VEGFR2-independent. Opening these K+ channels can also lead to VEGF-independent vasodilation. Herein, the objective is to unveil novel cellular mechanisms of peptide Lv in VEGF/VEGFR2- independent angiogenesis and vasodilation. The central hypothesis is that peptide Lv activates and augments IKCa in retinal endothelial cells that consequently leads to VEGF/VEGFR2-independent angiogenesis and vasodilation, the underlying mechanism of resistance to anti-VEGFs. Two Aims combining in vitro, ex vivo, and in vivo approaches to decipher peptide Lv-IKCa axis in VEGF/VEGFR2-independent angiogenesis and vasodilation will be carried out by using peptide Lv null (peptide Lv-/-), IKCa null (Kcnn4-/-), and vascular endothelial cell-specific knockout of VEGFR2 (VEGFR2iΔEC) mice. Completion of the proposed research will unveil new mechanisms of peptide Lv in VEGF/ VEGFR2-independent angiogenesis and vasodilation, which will have a direct impact on the future development of blocking peptide Lv-downstream targets as a therapeutic tool against ocular pathological neovascularization.

项目概要抗血管内皮生长因子（VEGF）疗法广泛用于治疗眼部疾病新生血管形成，但近 30% 的患者对抗 VEGF 药物无反应。此外，阻止复发性新生血管形成所需的重复抗 VEGF 治疗常常会导致意外的后果副作用包括视网膜脱离，甚至失明。因此，寻找不依赖 VEGF 的血管生成因素并揭示其潜在机制成为帮助对抗复发的迫切临床需求这些疾病中新血管形成和抗 VEGF 的抗性。 Lv肽是新发现的早期增殖性糖尿病视网膜病变 (PDR) 患者视网膜中血管生成肽的表达上调以及患有氧诱导视网膜病变（OIR）的小鼠，其特征是眼部病理性新生血管形成。尽管它与 VEGF 家族成员和 VEGF 受体 (VEGFR) 没有序列同源性，但肽 Lv 促进体外和体内血管生成。抗 Lv 肽的抗体，抗 Lv，不仅能抑制 VEGF- 引发内皮细胞增殖，还可以有效阻止 OIR 小鼠的病理性新生血管形成，以及激光诱导脉络膜新生血管形成。此外，肽Lv不仅协同促进 VEGF 诱导血管生成，但也引起 VEGF/VEGFR2/一氧化氮非依赖性血管舒张。慢性的现有血管的血管舒张导致血管通透性增加，刺激血管生成，并促进新血管形成。血管扩张剂与早期年龄相关性黄斑的发病率增加约 70% 相关变性（AMD）。因此，肽Lv可能通过促进PDR和湿性AMD的发病机制参与。 VEGF/VEGFR2 依赖性和非依赖性血管生成和血管舒张。然而，机械作用 Lv 肽在介导不依赖 VEGF 的血管生成和血管舒张方面的作用尚不清楚。肽Lv为能够增强中间电导钙依赖性钾通道 (IKCa) 的蛋白质表达在培养的内皮细胞中。内皮细胞中 K+ 通道的激活，尤其是 IKCa，对于血管生成非常重要这可以是 VEGF/VEGFR2 独立的。打开这些 K+ 通道也可以导致 VEGF 不依赖性血管舒张。本文的目标是揭示肽 Lv 在 VEGF/VEGFR2- 中的新细胞机制独立的血管生成和血管舒张。核心假设是肽 Lv 激活并增强 IKCa 在视网膜内皮细胞中，从而导致 VEGF/VEGFR2 独立的血管生成和血管舒张，抗 VEGF 耐药的潜在机制。结合体外、离体和体内方法的两个目标破译 VEGF/VEGFR2 独立血管生成和血管舒张中的肽 Lv-IKCa 轴将通过使用肽 Lv null (肽 Lv-/-)、IKCa null (Kcnn4-/-) 和血管内皮细胞特异性敲除 VEGFR2 (VEGFR2iΔEC) 小鼠。拟议研究的完成将揭示肽 Lv 在 VEGF/ 中的新机制不依赖VEGFR2的血管生成和血管舒张，这将直接影响未来的发展阻断肽 Lv 下游靶标作为对抗眼部病理性新生血管形成的治疗工具。