Tyrosine Phosphorylation in Lens Cell Differentiation

晶状体细胞分化中的酪氨酸磷酸化

• 批准号: 6881050
• 负责人: A. Sue Menko
• 金额: $ 35.33万
• 依托单位: THOMAS JEFFERSON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-06-02 至 2007-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6881050
• 关键词: biological signal transduction; cadherins; cataract; cell differentiation; chick embryo; embryo /fetus tissue /cell culture; enzyme activity; enzyme induction /repression; fluorescence microscopy; gel electrophoresis; immunoelectron microscopy; immunoprecipitation; lens; lens disorder; lens proteins; phosphorylation; physiologic stressor; protein structure function; protein tyrosine kinase; thermodynamics; tissue /cell culture; western blottings

DESCRIPTION (provided by applicant): Activation of Src tyrosine kinases occurs in response to oxidative, heat, and UV stress, all stress stimuli that promote the formation of lens cataract. We have found that inhibition of Src family tyrosine kinases (SFKs) blocks the development of lens opacity. In this proposal we will identify the molecular mechanisms by which SFK activation induces cataract formation. Our long term objectives are to identify the alterations in signaling pathways that lead to lens disease. The signaling intermediates in these networks are likely candidates for pharmaceutical intervention to suppress the formation of lens opacities. Key to understanding how the activation of SFKs leads to cataract formation is the delineation of SFK functions in normal lens differentiation and development. We will determine the mechanisms whereby SFKs regulate cadherin function in the developing embryonic lens. To extend these studies to the pathophysiology of lens cataract, we will examine the structural and functional targets of inappropriately activation of SFKs, focusing on cadherin junction destabilization, using two Src-induced lens disease models. One is an in vitro model in which lens cell cultures are transformed with a temperature sensitive v-Src kinase with which we will dissect the molecular affects of Src activation on the stabilization and function of lens cadherin junctions at different stages of development. These studies will be paralleled in a whole lens culture model that closely approximates stress-induced cataract. In this model we will be able to link the molecular changes that result from the inappropriate activation of SFKs with the formation of lens opacities. We hypothesize that one mechanism by which SFKs influence lens cell differentiation is through their regulation of cadherin complexes and that inappropriate regulation of the SFK signaling pathways induces lens cataracts by destabilizing cadherin junctions. We propose to 1) determine the mechanisms whereby Src family kinases regulate cadherin function in normal lens cell differentiation; 2) determine the mechanisms whereby constitutive activation of the Src kinase interferes with the structure and function of lens cadherin junctions, using v-Src transformed lens cell cultures as a model for stress-induced lens disease; and 3) determine the mechanisms whereby the inappropriate activation of Src family kinases, through their targeting of cadherin junctions, induces formation of lens cataracts.

描述（由申请人提供）：Src酪氨酸激酶的激活是对氧化、热和紫外线应激的反应，所有应激刺激都会促进晶状体白内障的形成。我们发现抑制Src家族酪氨酸激酶（SFKs）可阻断晶状体混浊的发展。在这个建议中，我们将确定SFK激活诱导白内障形成的分子机制。我们的长期目标是确定导致晶状体疾病的信号通路的改变。这些网络中的信号中间体可能是药物干预抑制晶状体混浊形成的候选者。了解SFK激活如何导致白内障形成的关键是描述SFK在正常晶状体分化和发育中的功能。我们将确定sfk在胚胎晶状体发育中调节钙粘蛋白功能的机制。为了将这些研究扩展到晶状体白内障的病理生理，我们将使用两种src诱导的晶状体疾病模型，研究SFKs不适当激活的结构和功能靶点，重点关注钙粘蛋白连接不稳定。一个是体外模型，其中晶状体细胞培养物用温度敏感的v-Src激酶转化，我们将通过该模型分析Src激活对晶状体钙粘蛋白连接在不同发育阶段的稳定性和功能的分子影响。这些研究将在整个晶状体培养模型中并行进行，该模型非常接近应力性白内障。在这个模型中，我们将能够将sfk不适当激活导致的分子变化与晶状体混浊的形成联系起来。我们假设SFK影响晶状体细胞分化的一种机制是通过其对钙粘蛋白复合物的调节，SFK信号通路的不适当调节通过破坏钙粘蛋白连接而诱发晶状体白内障。我们建议1)确定Src家族激酶在正常晶状体细胞分化中调节钙粘蛋白功能的机制；2)利用v-Src转化晶状体细胞培养物作为应力诱导晶状体疾病的模型，确定Src激酶组成激活干扰晶状体钙粘蛋白连接结构和功能的机制；3)确定Src家族激酶的不适当激活，通过靶向钙粘蛋白连接，诱导晶状体白内障形成的机制。