Matrix Metalloproteinases-Subcapsular Cataract Formation

描述：(申请人摘要)镜片透明度丧失，或 白内障，是世界上致盲的主要原因。两种相关形式的 白内障，包膜下，白内障和继发性白内障，涉及的增加 晶状体上皮细胞增殖转化为斑块的实验研究 表达收缩的大的“纺锤形”肌成纤维细胞 细丝，a-平滑肌肌动蛋白(a-SMA)。这个项目的长期目标是 为了确定细胞外信号，它改变了基因组成和 晶状体上皮细胞在白内障囊下形成过程中的表型。 具体地说，假设基质金属蛋白酶(MMPs)，发挥一个 晶状体上皮细胞向间充质细胞转化过程中的功能作用 肌成纤维细胞(EMT)，包膜下白内障的标志特征和 将对继发性白内障进行调查。由此得出的初步发现 实验室研究表明，伴随EMT的转化生长因子-β诱导的白内障模型 诱导大鼠体内明胶酶A(MMP2)的表达。今年5月 反映MMP的下游参与，而不是最初的原因。 然而，同样有可能的是，MMP在启动过程中扮演着更积极的角色 导致白内障形成的事件。例如，已经显示了NRAP 直接影响多种细胞的EMT，激活潜伏的转化生长因子-β。 拟议的研究将区分这两种不同的假设。 采用转化生长因子-β诱导的大鼠模型，观察不同的诱导时间和诱导水平。 将研究基质金属蛋白酶-2和其他候选基质金属蛋白酶，包括基质金属蛋白酶-3和基质金属蛋白酶-9 采用免疫组织化学、酶谱分析和蛋白质印迹分析。的表达 这些MMPs将与肌成纤维细胞的出现相关，表达 A-SMA。在培养模型中将使用MMPs的合成抑制剂来 确定是否需要一个或多个MMP来调节转化生长因子-b 诱发的白内障改变。如果MMPs直接参与白内障的发生， 阻断基质金属蛋白酶表达和活性的能力可能对晶状体有很大的影响 和白内障研究，因为它将为调查 预防白内障的新疗法。大鼠转化生长因子-β模型的建立 将小鼠的晶状体适配，以利用基质金属蛋白酶基因敲除小鼠进行 确定候选基质金属蛋白酶在囊下白内障中的个体作用(S) 队形。

DESCRIPTION: (Applicant's Abstract) Loss of transparency of the lens, or cataract, is the leading cause of blindness in the world. Two related forms of cataract, subcapsular,cataract and secondary cataract, involve the increased proliferation and transformation of lens epithelial cells (LECs) into plaques of large "spindle shaped" myofibroblasts which express the contractile filament, a-smooth muscle actin (a-SMA). The long-term goal of this project is to determine the extracellular signals, which alter the genetic makeup and phenotype of lens epithelial cells during subcapsular cataract formation. Specifically, the hypothesis that Matrix Metalloproteinases ( MMPs), play a functional role in the transition of lens epithelial cells into mesenchymal or myofibroblast cells (EMT), a hallmark feature of subcapsular cataracts and secondary cataract will be investigated. Preliminary findings from this laboratory show that accompanying the EMT in the TGF-b induced cataract model in rats is the induction in expression of gelatinase A (MMP-2). This may reflect a downstream involvement of MMPs, secondary to the initial cause. However, it is equally probable that MMPs play a more active role in initiating the events leading up to cataract formation. For example, NRAPs have been shown to directly influence the EMT of many cell types and to activate latent TGF-b. The proposed studies will distinguish between these two alternate hypotheses. Using the TGF-b induced model in rats, the timing and level of induction of MMP-2 and additional candidate MMPs, including MMP-3 and MMP-9 will be examined with immunohistochemistry, zymography and western blot analysis. Expression of these MMPs will be correlated with the appearance of myofibroblasts expressing a-SMA. Synthetic inhibitors of MMPs will be used in the culture model to determine if one or more of the MMPs is required for mediating the TGF-b induced cataractous changes. If MMPs directly participate in cataractogenesis, the ability to block MMP expression and activity may be of high impact to lens and cataract research since it would provide the basis for investigation of a novel therapy for the prevention of cataracts. Finally, the TGF-b model in rats will be adapted to the mouse lens in order to use MMP knockout mice for determining the individual role(s) of candidate MMPs in subcapsular cataract formation.