GROWTH AND DIFFERENTIATION OF AIRWAY GLANDS

患有分泌过多症的个体的气道表现出腺 肥大以及腺体内的浆液-粘液细胞移位。 这些反映了疾病相关的腺体生长异常， 分化 拟议研究的目标是获得信息 控制这些过程的机制。 所以这些机制 与正常发育和疾病相关，可以进行比较， 研究将在两个模型系统中进行：（1）气管， 新生大鼠，其中腺体在出生后第7天和第28天之间发育， (2)支原体感染的成年大鼠的气管，其中新的腺体 在感染后第7天至第42天之间发展。 研究列于 具体目标1将通过共聚焦显微镜确定尺寸和 出生后和出生后气管粘膜下腺体的分布 体内感染时间点以及体外腺体生长 外植体系统。 具体目标2下列出的研究将确定 每个模型中腺芽产生的细胞类型，使用双 免疫荧光来确定准备分裂和 表达表型特异性标记。 他们还将通过PCR确定， 免疫荧光和原位杂交是否升高， 特定生长因子和/或其受体的局部浓度 在这些细胞的有丝分裂之前。 因果关系的证据 特定的生长因子和腺体生长之间的关系将通过使用 体外腺体生长外植体系统中的中和抗体。 具体目标3下列出的研究将确定细胞外基质- 降解酶的局部组织浓度升高， 每个模型中腺体生长的时间，并寻找因果关系的证据 特定酶和腺体生长之间的关系， 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被 鉴定 具体目标4下列出的研究将检查浆液性 通过识别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，转录起始位点 映射，并使用常规方法鉴定调控DNA序列。 DNA调控序列特异性参与启动 溶菌酶在浆液细胞分化过程中的转录将是 使用体内足迹的新方法鉴定。 转录 与这些序列相互作用的因子将被分离。 知识 从这些研究中获得的信息将有望表明药理学 采取干预措施，抑制腺体过度生长和分化 与高分泌气道相关的异常。

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.