MUC 2 GENE ACTIVATION IN DEVELOPMENT AND DISEASE

慢性阻塞性气道疾病，如囊性纤维化， 以粘蛋白过度产生为特征。随着时间的推移，这可能导致 粘液栓形成、感染、支气管扩张、呼吸道感染 不足和死亡。对这一系列事件的理解 将有助于设计抑制它的方法。 上一节课，我们的实验证实了一个假设， 在实验诱导的高分泌中， 内毒素诱导大鼠粘蛋白2（MUC 2）mRNA表达 航空公司）。我们的实验还揭示了MUC 2的阶段性上调 在气管发育的早期。拟议研究的目标是获得 这些事件是如何被触发和控制的。研究 将使用原位杂交， MUC 2在气管发育中激活的时间过程。在 此外，他们还将通过凝胶电泳鉴定相关的蛋白质-DNA相互作用， 转移和足迹分析，分离足迹蛋白，并绘制 在发育过程中表达的时间和地点。他们还将 试图确定控制粘液细胞表型的基因作为一个整体 并鉴定激活其表达的间充质诱导因子。 特定目标2下列出的研究将使用上皮细胞 培养物中，无论先前观察到的MUC 2的内毒素上调 在体内是直接作用或由中性粒细胞产物介导。其他 研究将确定内毒素诱导粘蛋白的程度， 转录或转录后，并确定蛋白质-DNA 相互作用介导这种诱导。因为最近的实验 显示MUC 2上调假单胞菌（PA）的产品，额外的 研究将通过类似于这些方法分析PA-MUC 2诱导， 用于分析内毒素-MUC 2诱导，并尝试鉴定 PA上清液中的活性成分。 从这些获得的信息 研究将有望提出药物干预，以抑制 在人体气道中产生过多的粘蛋白。

Chronic obstructive airway diseases such as cystic fibrosis are characterized by mucin overproduction. Over time, this can lead to the formation of mucus plugs, infection, bronchiectasis, respiratory insufficiency, and death. An understanding of how this sequence of events is triggered would help in the design of methods to inhibit it. During the last period, our experiments confirmed the hypothesis that an early event in experimentally induced hypersecretion is the upregulation of steady state mucin (MUC 2) mRNA (induced by endotoxin instillation in rat airways). Our experiments also revealed a phasic upregulation of MUC 2 early in tracheal development. The goal of the proposed studies is to gain information about how these events are triggered and controlled. Studies listed under Specific Aim l will determine, using in situ hybridization, the time course of MUC 2 activation in the developing trachea. In addition, they will identify relevant protein-DNA interactions by gel shift and footprinting assays, isolate footprinted proteins and map the time and place of their expression during development. They will also attempt to identify genes controlling the mucous cell phenotype as a whole and identify mesenchymal induction factors activating their expression. Studies listed under Specific Aim 2 will determine, using epithelial cell cultures, whether the endotoxin upregulation of MUC 2 previously observed in vivo is a direct effect or is mediated by neutrophil products. Other studies will determine the extent to which mucin induction by endotoxin is transcriptional or post-transcriptional and identify protein-DNA interactions mediating this induction. Because recent experiments have revealed MUC 2 upregulation by Pseudomonas (PA) products, additional studies will analyze the PA-MUC 2 induction by methods similar to those used to analyze the endotoxin-MUC 2 induction and attempt to identify the active component in PA supernatant. The information gained from these studies will hopefully suggest pharmacological interventions to inhibit excessive mucin production in human airways.