GROWTH AND DIFFERENTIATION OF AIRWAY GLANDS

高分泌症患者的呼吸道表现为腺体。 腺体肥大和浆液粘液细胞移位。 这些反映了与疾病相关的腺体生长异常和 差异化。拟议研究的目标是获取信息 关于控制这些过程的机制。因此，这些机制 与正常发育相关的疾病可以比较，实验性的 研究将在两个模型系统中进行：(1)大鼠的气管 新生大鼠，其中腺体在出生后7天和28天之间发育 (2)支原体感染的成年大鼠气管内有新生腺体。 在感染后7天至42天之间发展。以下列出的研究 特定目标1将通过共聚焦显微镜确定大小和 气管粘膜下腺在特定的出生后和出生后的分布 体内和体外腺体生长中的感染时间点 外植体系统。在特定目标2下列出的研究将确定 在每个模型中产生腺芽的细胞类型，使用双 免疫荧光来定义细胞既准备分裂又 表达表型特异性标记。他们还将通过聚合酶链式反应来确定， 免疫荧光和原位杂交检测 特定生长因子和/或其受体的局部浓度 在这些细胞有丝分裂之前。因果关系的证据 具体的生长因子和腺体生长之间的关系将使用 体外腺体生长外植体系统中的中和抗体。 在特定目标3下列出的研究将确定细胞外基质- 局部组织浓度升高的降解酶 每种模型的腺体生长时间和寻找原因的证据 特异酶与腺体生长的关系 体外腺体生长外植体系统中的中和抗体。 控制与腺体生长相关的酶的机制将是 已确认身份。在特定目标4下列出的研究将检查浆液性 识别DNA-蛋白质相互作用的分化机制 控制浆液细胞特异性溶菌酶转录。大鼠溶菌酶 CDNA和基因组克隆将被分离，转录起始点 使用常规方法绘制并鉴定调控DNA序列。 DNA调控序列特异性地参与启动 溶菌酶在浆液细胞分化过程中的转录 使用一种新的活体足迹方法进行鉴定。转录 与这些序列相互作用的因素将被分离出来。知识 从这些研究中获得的信息将有望提供药理方面的帮助 抑制腺体过度生长和分化的干预措施 与过度分泌性呼吸道相关的异常。

The airways of individuals suffering from hypersecretion exhibit gland hypertrophy as well as a serous-mucous cell shift within the glands. These reflect disease-related abnormalities in gland growth and differentiation. The goal of the proposed studies is to gain information about the mechanisms controlling these processes. So that mechanisms relevant to normal development and disease can be compared, experimental studies will be performed in two model systems (1) the trachea of the newborn rat, in which glands develop between postnatal days 7 and 28 and (2) the trachea of the mycoplasma-infected adult rat, in which new glands develop between postinfection days 7 and 42. Studies listed under Specific Aim 1 will determine by confocal microscopy the size and distribution of tracheal submucosal glands at defined postnatal and post- infection time points in vivo as well as in an in vitro gland growth explant system. Studies listed under Specific Aim 2 will identify the cell type from which gland buds arise in each model, using double immunofluorescence to define cells that are both preparing to divide and express phenotype-specific markers. They will also determine by PCR, immunofluorescence and in situ hybridization whether elevations in the local concentration of specific growth factors and/or their receptors precede mitosis in these cells. Evidence for causal relationships between specific growth factors and gland growth will be sought using neutralizing antibodies in the in vitro gland growth explant system. Studies listed under Specific Aim 3 will identify extracellular matrix- degrading enzymes whose local tissue concentrations are elevated at the time of gland growth in each model and seek evidence for causal relationships between specific enzymes and gland growth using neutralizing antibodies in the in vitro gland growth explant system. Mechanisms controlling enzymes relevant to gland growth will be identified. Studies listed under Specific Aim 4 will examine serous differentiation mechanisms by identifying DNA-protein interactions controlling serous cell-specific lysozyme transcription. Rat lysozyme cDNAs and genomic clones will be isolated, the transcription start site mapped, and regulatory DNA sequences identified using routine methods. DNA regulatory sequences specifically involved in the initiation of lysozyme transcription during serous cell differentiation will be identified using a novel method of in vivo footprinting. Transcription factors interacting with these sequences will be isolated. Knowledge gained from these studies will hopefully suggest pharmacological interventions to inhibit excessive gland growth and differentiation abnormalities associated with hypersecretory airways.