MEMBRANE PHYSIOLOGY IN MAST CELL DIFFERENTIATION

肥大细胞和免疫球蛋白E(IgE)在过敏和 哮喘，而且它们与炎症有关。在所研究的大多数物种中， 定位于不同组织的肥大细胞在功能上存在异质性； 它们对促分泌剂和血管紧张素转换酶抑制剂的反应明显不同 分泌物，如抗哮喘药物色甘露；一些增殖和 免疫球蛋白E受体的交联性反应分泌淋巴因子 寄生虫感染和其他人不会。与此功能关联 异质性是显著的结构和生化特化。这 异质性及其产生的分化过程是 在啮齿动物中定义最好，尤其是大鼠，其中两种肥大细胞亚型是 公认的粘膜肥大细胞(MMC)和浆膜肥大细胞。它是 可能肥大细胞亚群的膜生理学不同，它 这种差异可能有助于功能多样性。 例如，抗原驱动的钙信号严重依赖于细胞膜。 电势，而这又受离子通道的调节。从长远来看 这项工作的目标是了解肥大细胞在 分子水平，这里的重点是离子通道的表达 肥大细胞分化。尽管大鼠的离子通道谱系 部分鉴定了浆膜肥大细胞和转化的大鼠MMC， 目前尚无正常大鼠MMC的相应数据。在这里，我们建议使用 膜片钳记录对初级心肌细胞离子通道的研究 大鼠MMC和骨髓来源的肥大细胞(BMMC)--肥大的制备方法 在体外分化的细胞与MMC非常相似。我们将使用 荧光染料的数字成像显微镜表征IgE- MMC和BMMC介导的钙信号和膜电位的变化。 肥大细胞K+通道在膜调节中的可能作用 潜在的，钙信号，和分泌将被探索。最后， 选择性表达的离子通道将作为潜在的靶标进行测试 药物阻断过敏和炎症介质的分泌， 抑制白介素3依赖的大鼠骨髓基质细胞增殖。 这项工作将促进我们对肥大细胞异质性的理解和 提供关于大鼠粘膜离子通道生理学的缺失章节 肥大细胞。它还可能产生一种新的药理学策略 过敏症或哮喘的干预。

Mast cells and immunoglobulin E (IgE) play a pivotal role in allergies and asthma, and they are implicated in inflammation. In most species examined, mast cells localized in different tissues are functionally heterogeneous; their response varies markedly to secretagogues and inhibitors of secretion such as the anti-asthmatic drug cromolyn; some proliferate and secrete lymphokines in response to cross-linkage of IgE receptors or parasite infections and others do not. Associated with this functional heterogeneity is marked structural and biochemical specialization. This heterogeneity and the differentiation process that gives rise to it are best-defined in rodents, especially rats, where two mast cell subtypes are recognized, mucosal mast cells (MMC) and serosal mast cells. It is probable that the membrane physiology of mast cell subsets differs, and it is possible that such differences contribute to functional diversity. Antigen-driven calcium signaling, e.g., depends critically on membrane potential, and this in turn is regulated by ion channels. The long term goal of this work is to understand mast cell differentiation at the molecular level, and the focus here is on ion channel expression during mast cell differentiation. Although the ion channel repertoires of rat serosal mast cells and a transformed rat MMC are partially characterized, there are no corresponding data for normal rat MMC. Here we propose to use patch-clamp recording to characterize the ion channels present in primary rat MMC and bone marrow-derived mast cells (BMMC), a preparation of mast cells differentiated in vitro that closely resembles MMC. We will use digital imaging microscopy of fluorescent dyes to characterize IgE- mediated calcium signaling and membrane potential changes in MMC and BMMC. The possible role of mast cell K+ channels in regulation of membrane potential, calcium signaling, and secretion will be explored. Finally, selectively expressed ion channels will be tested as potential targets for pharmacological blockade of allergic and inflammatory mediator secretion, and for inhibition of interleukin-3 dependent proliferation of rat BMMC. This work will advance our understanding of mast cell heterogeneity and provide a missing chapter on the ion channel physiology of rat mucosal mast cells. It also could yield a new strategy for pharmacologic intervention in allergies or asthma.