ROLE OF BRADYKININ RECEPTORS IN HUMAN LUNG FIBROSBLASTS

本建议的目标是：（a）确定 肽介体缓激肽与其受体相互作用，和（B）所述肽介体缓激肽 特异性受体靶细胞的反应：发现成纤维细胞 在间质结缔组织中。 初步研究将在 表达缓激肽受体的特定培养细胞系统， 包括人肺成纤维细胞株W1 - 38和IMR-90，另外 我们将开发的人肺和皮肤成纤维细胞株， HSDM 1C1小鼠纤维肉瘤建立细胞系。 受体数量和 亲和力将通过放射性配体结合和结构/活性来确定 天然缓激肽相关肽，合成类似物， 和受体拮抗剂进行评估。 受体脱敏将 探索环核苷酸的相对贡献，功能或 受体与连接途径的物理解偶联，以及靶细胞 结合配体的降解，可能通过受体相关机制。 待定义的靶细胞应答包括细胞因子的量和类型。 通过环氧合酶和脂氧合酶产生的花生四烯酸衍生物 途径，环核苷酸水平的变化和总细胞 蛋白质合成 该项目将评估一个特定的 缓激肽受体可能与特定的靶细胞反应相关， 例如增加蛋白质合成或产生特征性 与炎症或创伤相关的次级介质。 这些研究将 然后扩展到新鲜分离的人肺成纤维细胞和完整肺 组织切片 拟议的研究将确定的机制， 缓激肽受体介导的生物活性。 它将寻求 确定这些在皮肤和肺成纤维细胞中是否相似，或者 肺成纤维细胞在某种程度上不同， 和人类肺损伤的进展。

The goals of this proposal are to define (a) the mechanisms by which the peptide mediator bradykinin interacts with its receptors, and (b) the response of specific receptor-bearing target cells: the fibroblasts found in interstitial connective tissue. Initial studies will be carried out in specific cultured cell systems which express bradykinin receptors, including the human lung fibroblast strains W1-38 and IMR-90, additional strains of both human lung and skin fibroblasts which we will develop, and the HSDM1C1 murine fibrosarcoma established cell line. Receptor number and affinity will be determined by radioligand binding, and structure/activity relationships for natural bradykinin-related peptides, synthetic analogs, and receptor antagonists will be assessed. Receptor desensitization will be explored for relative contributions of cyclic nucleotides, functional or physical uncoupling of receptor from linked pathways, and target cell degradation of bound ligand, possibly by a receptor-associated mechanism. The target cell responses to be defined include amount and type of arachidonate derivatives produced via the cyclo-oxygenase and lipoxygenase pathways, changes in cyclic nucleotide levels and alterations in total cell protein synthesis. This project will assess whether a particular bradykinin receptor may correlate with a specific target cell response, such as increased protein synthesis or production of characteristic secondary mediators related to inflammation or trauma. These studies will then be extended to freshly-isolated human lung fibroblasts and intact lung tissue slices. The proposed research will define the mechanisms of bradykinin receptor-mediated biologic activities. It will seek to determine if these are similar in skin and lung fibroblasts, or if they differ in lung fibroblasts in some way which contributes to the development and progression of human lung injury.