Role of MMPs in TGFbeta-induced Cataract Formation

MMPs 在 TGFbeta 诱导的白内障形成中的作用

• 批准号: 8188198
• 负责人: Judith A West-Mays
• 金额: $ 24.27万
• 依托单位: MCMASTER UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-03-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8188198
• 关键词: Adhesions; Anterior; Antibodies; Blindness; Cataract; Cataract Extraction; Cell Adhesion Molecules; Cell-Cell Adhesion; Complication; Crystalline Lens; Data; Developed Countries; Development; Disease; E-Cadherin; Epithelial; Epithelial Cells; Event; Extracapsular; Eye; Fibrosis; Funding; Gelatinase A; Gelatinase B; Goals; Grant; Lead; Link; Matrix Metalloproteinase Inhibitor; Matrix Metalloproteinases; Mediating; Mediator of activation protein; Mesenchymal; Modeling; Molecular; Mus; Mutant Strains Mice; Myofibroblast; North America; Nuclear Translocation; Operative Surgical Procedures; Organ; Pathway interactions; Play; Prevention; Rattus; Recombinants; Research; Role; Signal Pathway; Signal Transduction; Smooth Muscle Actin Staining Method; Testing; Therapeutic; Tissues; Transforming Growth Factor beta; Wild Type Mouse; Work; cost; design; epithelial to mesenchymal transition; in vivo Model; inhibitor/antagonist; lens; lens transparency; morphogens; mouse model; myocardin; prevent; research study; transcription factor; treatment strategy

DESCRIPTION (provided by applicant): Epithelial-mesenchymal transition (EMT) has been shown to play an important role in the fibroses of multiple organs and tissues, including the ocular lens, where it contributes to both anterior subcapsular cataracts (ASC) and posterior capsular opacification (PCO), also known as secondary cataract. Increased proliferation of lens epithelial cells (LECs), and EMT of LECs into myofibroblasts, involving a loss of the cell-cell adhesion molecule E-cadherin and an induction in ?-smooth muscle actin (?SMA) expression are early events in both ASC and PCO. Transforming growth factor beta (TGF?) is a pleotropic morphogen that has been shown to induce the EMT of LECs and subsequent formation of ASC, as well as, PCO. Using a previously developed rat lens culture model in which exogenous TGF? induces ASC we have shown that treatment with inhibitors to the matrix metalloproteinases (MMP), specifically MMP-2 and MMP-9, suppresses TGF? -induced cataractous changes, including EMT. Studies from the previous grant period further show that these two MMPs likely work cooperatively and/or redundantly in the development of these cataracts. For example, using a model of ASC involving the delivery of Ad TGF? to the eye we have shown that MMP-9 KO mice develop cataracts, albeit they are delayed compared to wild-type mice. Thus, inhibiting both MMPs may be required to prevent EMT and subsequent cataractogenesis. The potential mechanism by which these MMPs mediate EMT and cataract formation was identified during the previous funding period and involves disruption of E-cadherin. Preliminary data suggests that disruption and shedding of E-cadherin results in downstream signaling events linked to EMT including nuclear translocation of ?-catenin and the myocardin-related transcription factor (MRTF-A). However, the requirement for these signaling intermediates in ASC and PCO and how MMPs are involved is not known. In the current application we investigate these TGF? -mediated signaling pathways using multiple ex vivo and in vivo models of ASC and PCO. In addition, we outline experiments that will directly determine the unique and/or cooperative roles of MMP-2 and MMP-9 in ASC formation. Ultimately, our goal is to define the TGF? - mediated pathways controlling EMT and fibrosis in ASC and PCO in order to design therapeutics for mitigating these diseases. PUBLIC HEALTH RELEVANCE: Loss of transparency of the lens, or cataract, is the leading cause of blindness worldwide despite the availability of effective surgery in developed countries. Extracapsular cataract extraction is the most frequently performed surgical procedure in North America, costing over 3.5 billion dollars each year, and can frequently lead to complications such as the development of secondary cataract (posterior capsular opacification (PCO). Thus, an understanding of the cellular and molecular mechanisms regulating the normal and pathological differentiation of the lens is necessary in order to develop therapeutic strategies for the treatment and/or prevention of cataracts. In the proposed research we will investigate the cell signaling mechanisms responsible for two fibrotic cataracts, anterior subcapsular cataracts (ASC) and PCO and further determine how these mechanisms can be inhibited. Specifically we will focus on those pathways mediated by transforming growth factor beta (TGF?) and the matrix metalloproteinases (MMPs) since both of have been implicated in these cataracts. Ultimately, it is hoped that the data obtained from the proposed studies will lead to therapeutic strategies for mitigating cataract formation.

描述（由申请人提供）：上皮-间充质转化（EMT）已被证明在多个器官和组织的纤维化中起重要作用，包括眼透镜，其导致前囊下白内障（ASC）和后囊膜混浊（PCO），也称为继发性白内障。透镜上皮细胞（LEC）增殖增加，LEC向肌成纤维细胞的EMT，涉及细胞-细胞粘附分子E-钙粘蛋白的丢失和？平滑肌肌动蛋白（？SMA）表达是ASC和PCO中的早期事件。转化生长因子β（TGF？）是一种多效形态原，已显示诱导LEC的EMT和随后的ASC以及PCO的形成。使用先前开发的大鼠透镜培养模型，其中外源性TGF？诱导ASC，我们已经表明，治疗与抑制剂基质金属蛋白酶（MMP），特别是MMP-2和MMP-9，抑制TGF？- 引起的白内障变化，包括EMT。上一个资助期的研究进一步表明，这两种MMP可能在这些白内障的发展中合作和/或冗余地工作。例如，使用一个模型的ASC涉及交付的Ad TGF？我们已经表明MMP-9 KO小鼠发生白内障，尽管与野生型小鼠相比它们延迟。因此，可能需要抑制两种MMPs来预防EMT和随后的白内障发生。这些基质金属蛋白酶介导EMT和白内障形成的潜在机制在之前的资助期间被确定，涉及E-钙粘蛋白的破坏。初步数据表明，E-钙粘蛋白的破坏和脱落导致与EMT相关的下游信号传导事件，包括？catenin和myocardin-related transcription factor（MRTF-A）。然而，ASC和PCO中对这些信号传导中间体的需求以及MMP如何参与尚不清楚。在目前的应用中，我们调查这些TGF？使用ASC和PCO的多个离体和体内模型，研究了β-介导的信号传导途径。此外，我们概述了实验，将直接确定独特的和/或合作的作用，MMP-2和MMP-9在ASC的形成。最终，我们的目标是定义TGF？- 因此，本发明涉及控制ASC和PCO中的EMT和纤维化的介导的途径，以便设计用于减轻这些疾病的治疗剂。 公共卫生相关性：透镜的透明度丧失或白内障是世界范围内失明的主要原因，尽管在发达国家可以获得有效的手术。囊外白内障摘除术是北美最常进行的外科手术，每年花费超过35亿美元，并且经常导致并发症，例如继发性白内障（后囊混浊（PCO））的发展。因此，理解调节透镜的正常和病理分化的细胞和分子机制对于开发治疗和/或预防白内障的治疗策略是必要的。在拟议的研究中，我们将研究负责两种纤维化白内障，前囊下白内障（ASC）和PCO的细胞信号传导机制，并进一步确定如何抑制这些机制。具体来说，我们将集中在这些途径介导的转化生长因子β（TGF？）以及基质金属蛋白酶（MMPs），因为两者都与这些白内障有关。最终，希望从拟议的研究中获得的数据将导致减轻白内障形成的治疗策略。