DYNAMICS OF CALCIUM SIGNALING AND PRL GENE EXPRESSION

细胞内游离钙浓度的动态变化 ([Ca2+]）i，在基础和促分泌素中发挥重要作用- 催乳素（PRL）基因的调控。 事实上，催乳素基因 是最早发现Ca ~（2+）对基因表达的主要影响之一， 转录已经建立。 分泌催乳素的催乳素， 其他垂体前叶细胞，显示自发振荡， [Ca2+]i，其由电活动驱动并由 各种促垂体激素剂。 然而，精确的贡献 Ca 2+振荡对PRL基因表达率的影响仍然存在 由于需要和缺乏一项战略， 在同一个活细胞中动态监测这两个变量。 在这个提案中，我们计划通过使“实时” 在初级催乳素中PRL基因表达的测量， 通过数字成像进行[Ca 2 +]i测定， Fura-2的荧光显微镜。 通过这种组合策略，我们旨在 以：1）确定单细胞是否在振荡表型中变化 是随机或有序事件; 2）识别信号模式 （code）负责Ca 2+编码基因表达的变化。 这些研究的潜在健康影响变得显而易见 当人们认为[Ca 2 +]i作为信号分子无处不在时， 沿着其在会聚点处的定位， 信使通道 鉴于我们所掌握的分析能力， 拟议中的实验很可能是迄今为止测试 直接流行的观点认为，钙调节过程是 由[Ca 2 +]i振荡模式代码控制， 频率、振幅和/或形状。

Dynamic changes in the concentration of intracellular free calcium ([Ca2+])i, play an important role in both basal and secretagogue- regulated control of the prolactin (PRL) gene. In fact, the PRL gene is one of the first for which a primary effect of Ca2+ on gene transcription has been established. The PRL-secreting lactotrope, like other anterior pituitary cells, displays spontaneous oscillations of [Ca2+]i, which are driven by electrical activity and modulated by a variety of hypophysiotropic agents. However, the precise contribution of Ca2+ oscillations to the rate of PRL gene expression has remained obscure owing to the requirement for, and lack of, a strategy for dynamically monitoring both of these variables in the same, living cell. In this proposal, we plan to solve this problem by making "real-time" measurements of PRL gene expression in primary lactotropes that are also being subjected to [Ca2+]i, determinations by digital imaging, fluorescence microscopy of fura-2. Using this combined strategy, we aim to: 1) determine whether single cell shifts in oscillatory phenotypes are random or ordered events; 2) identify the signalling patterns (code) responsible for Ca2+ code of changes of gene expression. The potential health-related impact of these studies becomes obvious when one considers the ubiquity of [Ca2+]i as a signalling molecule along with its positioning at a point of convergence for other second messenger pathways. Given the analytical power at our disposal, the proposed experiments may well constitute the best chance yet to test directly the prevailing view that Ca2+-regulated processes are controlled by a code of [Ca2+]i oscillatory patterns which vary in frequency, amplitude, and/or shape.