POLARIZED SECRETION FROM INJURED AIRWAY EPITHELIUM

呼吸道上皮起着极化屏障的作用 吸入病原体和毒素，并作为涉及的几种媒介的来源 在对呼吸道损伤的最初反应中。纤维连接蛋白，一种细胞外的 基质蛋白被认为在呼吸道上皮细胞中起着不可或缺的作用 修理。在体外，呼吸道上皮细胞增加合成和分泌 转化生长因子-β刺激后纤维连接蛋白的变化 β)，一种被认为在组织修复中发挥关键作用的细胞因子 调节细胞的生长和分化。这位候选人已经花了 过去两年研究替代方案的两极分化监管 转化生长因子-β对气管上皮细胞纤维连接蛋白的剪接和分泌 细胞和拟议的实验是这一点的逻辑扩展 研究。首先，候选人将检查分泌物和替代方案 纤维连接蛋白在不同极化细胞类型中的剪接技术 例如免疫沉淀、免疫印迹和Northern分析。 第二，将进行使用碘标记的转化生长因子-β的交联实验 为了确定对转化生长因子-β的极化反应是否 由转化生长因子-β受体的表面差异表达介导。下一首, 候选人建议开发一种使用纤维连接蛋白的转基因系统 微型基因构建，以证实和进一步研究其作用 转化生长因子-β对纤维连接蛋白选择性剪接的影响。转染腺病毒载体 然后将使用纤维连接蛋白表达构建物来确认和探索 EIIIA结构域作为靶向信号的作用。

The respiratory epithelium serves both as a polarized barrier against inhaled pathogens and toxins and as a source of several mediators involved in the initial response to airway injury. Fibronectin, an extracellular matrix protein, is believed to play an integral role in airway epithelial repair. In vitro, airway epithelial cells increase synthesis and secretion of fibronectin after stimulation with transforming growth factor-beta (TGF- beta), a cytokine believed to play a crucial role in tissue repair by modulating cellular growth and differentiation. The candidate has spent the last two years investigating the polarized regulation of alternative splicing and secretion of fibronectin by TGF-beta in tracheal epithelial cells and the proposed experiments are a logical extension of this research. First, the candidate will examine the secretion and alternative splicing of fibronectin in various polarized cell types using techniques such as immunoprecipitation, immunoblotting, and northern analysis. Second, crosslinking experiments using iodinated TGF-beta will be performed in order to determine whether the polarized response to TGF-beta is mediated by differential surface expression of TGF-beta receptors. Next, the candidate proposes to develop a transfection system using a fibronectin minigene construct in order to confirm and further study the effects of TGF-beta on alternative splicing of fibronectin. Transfection of fibronectin expression constructs will then be used to confirm and explore the role of the EIIIA domain as a targeting signal.