Smart Polymer Based MK2 Inhibitor to Suppress Vascular Graft Intimal Hyperplasia

基于智能聚合物的 MK2 抑制剂可抑制血管移植物内膜增生

• 批准号: 8179533
• 负责人: Craig Lewis Duvall
• 金额: $ 18.2万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-01 至 2013-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8179533
• 关键词: Advanced Development; Adverse effects; Autologous; Biochemical; Biology; Blood Vessels; Bypass; Cells; Cellular Stress; Clinical; Complement; Complex; Coronary Artery Bypass; Cytoplasm; Data; Deposition; Development; Disease; Disulfides; Drug Delivery Systems; Endosomes; Ensure; Environment; Exposure to; Extracellular Matrix; F-Actin; Free Radicals; Goals; Harvest; Heat Shock Protein 27; Human; Hybrids; Hyperplasia; In Vitro; Intervention; Label; Lead; Lysosomes; MAP Kinase Gene; MAPK14 gene; Measures; Mediating; Mediator of activation protein; Membrane; Mitogen-Activated Protein Kinase Kinases; Mitogens; Modeling; Myocardial Ischemia; Operative Surgical Procedures; Oryctolagus cuniculus; Outcome; Pathway interactions; Peptides; Performance; Pharmacologic Substance; Phenotype; Phosphorylation; Phosphotransferases; Polymers; Positioning Attribute; Process; Production; Proliferating; Sampling; Saphenous Vein; Series; Smooth Muscle Myocytes; Specificity; Stress; Stress Fibers; System; Techniques; Testing; Therapeutic; Therapeutic Effect; Toxic effect; Transplantation; Validation; Vascular Graft; Vasodilation; Veins; Vertebral column; Vesicle; Western Blotting; base; cell behavior; comparative efficacy; design; di-block copolymer; experience; graft failure; high risk; improved; in vitro Assay; in vivo; inhibitor/antagonist; innovation; neointima formation; novel; polymerization; prevent; research study; small molecule; trafficking; uptake; vascular smooth muscle cell migration

DESCRIPTION (provided by applicant): Coronary artery bypass grafting (CABG) with autologous conduits effectively alleviates ischemic heart disease, but long-term graft patency is problematic. Graft failure is primarily attributable to intimal hyperplasia (IH), the process by which vascular smooth muscle cells (VSMCs) migrate, proliferate, and deposit excessive extracellular matrix (ECM) resulting in neointima formation. IH can occlude the lumen and is prone to rapid development into advanced graft disease, negating the surgical benefit. We have identified MAPKAP kinase II (MK2) as a potential target for pharmacological intervention for preventing vascular graft IH. MK2 is activated through a p38 mitogen activated kinase (MAPK) pathway that is triggered by the physical and biochemical stresses that VSMCs in the graft experience during transplant. Activated MK2, in turn, phosphorylates heat shock protein 27 (HSP27), a known downstream mediator of pathological VSMC behavior in IH. Because p38 MAPK functions are diverse, p38 inhibitors lead to nonspecific side effects. Thus, MK2 is a logical target for inhibiting a proximal trigger of IH, and the central hypothesis of this proposal is that efficient pharmacological inhibition of MK2 will prevent IH. Pharmaceutical companies' efforts to develop a small molecule MK2 inhibitor have been unsuccessful. Peptide inhibitors hold promise as an alternative with greater specificity and reduced toxicity, but barriers against intracellular delivery hinder their use. To test our hypothesis, a novel, "smart" polymer vehicle for intracellular delivery of a peptidic MK2 inhibitor (MK2i) is proposed. Preliminary data have shown a reduction in IH in human saphenous vein samples delivered MK2i via fusion to a cell penetrating peptide (CPP-MK2i). However, our mechanistic studies support the notion that CPP-mediated delivery suffers from compromised cytoplasmic bioactivity due to internalization into and sequestration within intracellular vesicles. The overall goal of this proposal is to overcome this cytoplasmic delivery barrier and to optimize MK2 inhibition using a CPP-internalized "smart" polymer (CISP) for MK2i peptide delivery (CISP-MK2i). The proposed "smart" polymer carrier will "sense" the acidic environment in the endosomes, which will trigger a sharp polymer transition into a more hydrophobic, membrane disruptive state that releases CISP-MK2i into the cytoplasm. Furthermore, CISP-MK2i has been designed with reducible attachments between MK2i and the "smart" polymer backbone, and upon reaching the cytoplasm, "cell- demanded" MK2i release will occur to ensure that the carrier does not sterically hinder MK2i activity. Three aims are outlined in the proposal for CISP-MK2i synthesis and a series of in vitro, ex vivo, and in vivo tests to compare the efficacy of MK2i delivery via CISP-MK2i versus CPP-MK2i. PUBLIC HEALTH RELEVANCE: Coronary artery bypass grafting with autologous conduits effectively alleviates ischemic heart disease, but long-term graft patency is problematic. Graft failure is primarily attributable to intimal hyperplasia (IH), the process by which vascular smooth muscle cells (VSMCs) migrate, proliferate, and deposit extracellular matrix (ECM) into a neointima. MAPKAP kinase II (MK2) activation by cellular stress during transplant is thought to be an important contributor to the pathological VSMC phenotype. Here we propose to develop and test a "smart" polymer-peptide hybrid delivery system capable of efficiently inhibiting MK2 and improving long-term vascular graft performance.

描述（由申请人提供）：带有自体导管的冠状动脉搭桥术（CABG）有效地减轻了缺血性心脏病，但长期的移植物通气是有问题的。移植失败主要归因于内膜平滑肌细胞（VSMC）迁移，增殖和沉积过多的细胞外基质（ECM）的过程，导致内膜形成。 IH可以阻塞管腔，并且容易发生为晚期移植疾病的快速发展，从而否定了手术益处。我们已经将MAPKAP激酶II（MK2）确定为防止血管移植IH的药理干预措施的潜在靶标。 MK2通过p38有丝分裂原激活的激酶（MAPK）途径激活，该途径是由移植过程中移植物经验中的物理和生化应激触发的。激活的MK2反过来磷酸化热激蛋白27（HSP27），这是IH中已知的病理VSMC行为下游介体。由于p38 MAPK功能是多种多样的，因此p38抑制剂会导致非特异性副作用。因此，MK2是抑制IH近端触发因素的逻辑靶标，并且该提案的中心假设是有效的MK2药理抑制作用将阻止IH。制药公司为开发小分子MK2抑制剂的努力没有成功。肽抑制剂具有更大特异性和降低毒性的替代方案，但抗细胞内递送的障碍阻碍了其使用。为了检验我们的假设，提出了一种用于细胞内递送肽MK2抑制剂（MK2I）的新颖的“智能”聚合物。初步数据显示，通过融合到细胞穿透肽（CPP-MK2I）的MK2I传递的人类隐静脉样品中IH的IH降低。但是，我们的机械研究支持这样的观念，即CPP介导的递送因内部化和隔离细胞内囊泡内部和隔离而导致细胞质生物活性受损。该提案的总体目标是克服这种细胞质递送障碍，并使用CPP内部化的“智能”聚合物（CISP）进行MK2I肽递送（CISP-MK2I）来优化MK2抑制。提出的“智能”聚合物载体将“感知”内体中的酸性环境，这将引发尖锐的聚合物过渡到更疏水的膜破坏性状态，从而将CISP-MK2I释放到细胞质中。此外，CISP-MK2I的设计在MK2I和“智能”聚合物主链之间具有还原的附件，并且在达到细胞质时，需要进行细胞的“ MK2I释放”，以确保携带者不会在空间上阻碍MK2I活性。在CISP-MK2I合成的建议中概述了三个目标，并进行了一系列体外，EX VIVO和体内测试，以比较MK2I通过CISP-MK2I与CPP-MK2I的MK2I递送的功效。 公共卫生相关性：冠状动脉旁路与自体导管有效地减轻缺血性心脏病，但长期的移植通畅率是有问题的。移植失败主要归因于内膜增生（IH），这是血管平滑肌细胞（VSMC）迁移，增殖和沉积细胞外基质（ECM）的过程。 MAPKAP激酶II（MK2）在移植过程中通过细胞应力激活被认为是病理VSMC表型的重要促进者。在这里，我们建议开发和测试能够有效抑制MK2并改善长期血管移植性能的“智能”聚合物肽混合递送系统。