Stimulus-Secretion Coupling in Mucosal Mast Cells: Studies at the Single-Cell Level

摘要9604432 Fewtrell钙在非兴奋性细胞中刺激-反应偶联的作用尚不清楚。群体内单个细胞的钙反应是极其多样的，经常显示钙的显著振荡，然而对细胞功能反应重要的钙信号的具体特征知之甚少。在这些研究中，细胞内钙和分泌的变化之间的时间关系将在单细胞水平的非兴奋细胞，使用粘膜肥大细胞系作为模型进行研究。这些细胞的钙反应已得到很好的表征，含有组胺，5-羟色胺和其他介质的分泌颗粒的胞吐作用通过indo-1光度法，和含有颗粒的5-羟色胺的分泌将在同一细胞中通过恒电位安培法同时监测。因此，可以测量与单个胞吐事件或分泌爆发相关的钙反应。荧光成像将同时监测大量单个细胞的钙反应。将使用对肥大细胞系、细胞克隆和转染的细胞系的各种刺激来测试胞内钙的增加对于胞吐是必需的这一假设。蛋白激酶C激活的必要性及其在调节分泌反应中的作用将在单细胞水平上重新研究。有关肥大细胞中钙信号传导的信息将有助于全面了解这一重要信号分子在许多不同细胞类型和系统中的作用和调控。***

Abstract 9604432 Fewtrell The role of calcium in stimulus-response coupling in non-excitable cells is not well understood. The calcium responses of individual cells within a population are extremely diverse, often displaying marked oscillations in calcium, however little is known about the specific features of the calcium signal that are important for the functional response of the cell. In these studies the temporal relationship between changes in intracellular calcium and secretion will be studied at the single cell level in non-excitable cells, using a mucosal mast cell line as a model. The calcium responses of these cells have been well characterized and the exocytosis of secretory granules containing histamine, serotonin and other mediators by indo-1 photometry, and the secretion of serotonin containing granules will be monitored simultaneously in the same cell by constant potential amperometry. Thus the calcium response associated with a single exocytotic events or burst of secretion can be measured. Fluorescence imagining will monitor the calcium responses of a large number of individual cells simultaneously. The hypothesis that an increase in intracellular calcium is essential for exocytosis will be tested using a variety of stimuli to mast cell lines, cell clones and transfected cell lines. The requirement for protein kinase C activation and its role in modulating the secretory response will be re-examined at the single cell level. Information obtained about calcium signaling in mast cells will contribute to the overall understanding of the role and regulation of this important signaling molecule in many different cell types and systems. ***