Cloaking Key MMP-9 Substrates to Probe the role of Their Cleavage in Plaque Ruptu

描述（由申请人提供）：基质金属蛋白酶(MMP)-9与斑块破裂有关，斑块破裂是大多数心血管疾病临床表现的原因。然而，目前尚不清楚这种多效酶切割哪些关键底物来控制疾病过程。利用一种独特的小鼠模型，再现了人类动脉粥样硬化斑块破裂的许多特征，我们建议开发潜在的可用于治疗的“隐形装置”，以防止两种蛋白质在我们已经证明被MMP-9破坏的途径中的分裂：凝固级联中的组织因子途径抑制剂（TFPI）和参与炎症消退的整合素¿2。而不是结合和抑制酶，特异性结合TFPI和整合素¿2的切割位点的药物将从肽样肽的组合文库中识别出来，这些肽样肽已被证明是蛋白质结合剂的丰富来源。在基于细胞的系统中，将建立对mmp -9介导的TFPI和整合素2蛋白水解的有效抑制，并在必要时增强肽结合和抑制的亲和力。类肽防止斑块破裂的能力将被测试，并将有助于确定底物蛋白水解在疾病进展中的生物学功能。探索类肽介导蛋白水解的底物选择性限制的能力也有可能为心血管疾病提供新的干预策略。

DESCRIPTION (provided by applicant): Matrix metalloproteinase (MMP)-9 is implicated in plaque rupture that is responsible for the majority of clinical manifestations of cardiovascular disease. However, it is still unclear what key substrates this pleiotropic enzyme cleaves to control the disease process. Using a unique mouse model which reproduces many features of human atherosclerotic plaque rupture, we propose to develop potential therapeutically applicable "cloaking devices" to prevent cleavage of two proteins in pathways that we've shown to be disrupted by MMP-9: tissue factor pathway inhibitor (TFPI) in the coagulation cascade and integrin ¿2 involved in the resolution of inflammation. Rather than binding and inhibiting the enzyme, agents that specifically bind the cleavage site of TFPI and integrin ¿2 will be identified from combinatorial libraries of peptide-like peptoids that have been shown to be a rich source of protein-binding agents. Effective inhibition of MMP-9-mediated proteolysis of TFPI and integrin ¿2 will be established in cell-based systems, and the affinity of peptoid binding and inhibition enhanced if necessary. The ability of the peptoids to prevent features of plaque rupture will then be tested, and will help determine the biological function of substrate proteolysis in disease progression. Exploration of the capacity of peptoids to mediate substrate-selective limitation of proteolysis also has the potential to provide new interventional strategies for cardiovascular disease. PUBLIC HEALTH RELEVANCE: Matrix metalloproteinase (MMP)-9 is implicated in plaque rupture that is responsible for the majority of clinical manifestations of cardiovascular disease, but it is still unclear what key substrates this pleiotropic enzyme cleaves to control the disease process. The goal of this proposal is to develop and test potential therapeutically applicable "cloaking devices" to prevent cleavage of two key proteins involved in the coagulation and inflammatory pathways that we've shown to be disrupted by MMP-9 proteolysis. The proposed studies will determine the biological function of specific substrate proteolysis for disease progression, and may establish a new approach for selective limitation of proteolysis as a potential interventional strategy for cardiovascular disease.