REGULATION AND FUNCTION OF MAST CELL SECRETED PROTEINASES

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。肥大细胞是组织对先天和适应性挑战的免疫反应的协调者。对肥大细胞的刺激导致多种促炎介质的释放，包括一类分泌的蛋白酶。这些蛋白酶是组织重塑的核心，这是生理和病理炎症反应的一个特征。当前研究的长期目标是了解肥大细胞中控制促炎反应的信号通路。从这一认识出发，我们希望确定炎症性疾病进展干预的新靶点。我们将实现三个具体目标。如上所述，肥大细胞对各种促炎刺激作出反应，包括ige介导的和先天免疫挑战，以及分泌物和神经递质。肥大细胞的这些不同的激活机制有一个关键的共性；所有这些都涉及细胞内游离钙水平的持续升高。事实上，在没有其他刺激的情况下，使用离子载体化合物的钙动员足以诱导肥大细胞活化。允许这种持续钙内流的钙通道是肥大细胞反应治疗性调节的重要靶点，但在分子水平上仍未明确。免疫刺激似乎诱导了一种高度选择性的、储存操作的钙电导。然而，肥大细胞的一些其他激活刺激会导致NSCC的激活，这可能是由TRP家族成员编码的。PI¿s实验室筛选了啮齿类动物和人类肥大细胞中TRP通道mRNA和蛋白的表达。肥大细胞含有TRPV2蛋白，该蛋白未被描述为对脂质配体有反应。肥大细胞中检测到TRPV4信息，而不是蛋白质，并且该通道的多种激活机制可能包括大麻素。我们检查的肥大细胞不含TRPV1，但表达大麻素敏感的TRPA1通道。我们现在提出的实验将旨在剖析肥大细胞中TRPA1的调控和功能。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Mast cells are orchestrators of tissue immune responses to innate and adaptive challenge. Stimulation of mast cells results in the release of diverse pro-inflammatory mediators, including a class of secreted proteinases. These proteinases are central to the tissue remodeling that is a feature of physiological, and pathological, inflammatroy responses. The long-term objective of the current proposal is to understand the signaling pathways that control pro-inflammatory responses in mast cells. From this understanding, we hope to identify novel targets for intervention in the progression of inflammatory diseases. We will address three specific aims. As described above, mast cells respond to various pro-inflammatory stimuli, including IgE-mediated and innate immunological challenges, as well as to secretagogues and neurotransmitters. These diverse activation mechanisms for mast cells have one key commonality; all involve the sustained elevation of intracellular free-calcium levels. In fact, calcium mobilization using ionophore compounds is sufficient to induce mast cell activation in the absence of other stimuli. The calcium channels that permit this sustained calcium influx are important targets for therapeutic modulation of mast cell responses, but remain undefined at the molecular level. Immunological stimuli appear to induce a highly selective, store-operated calcium conductance. However, several other activating stimuli for mast cells cause the activation of NSCC, which may be encoded by members of the TRP family. The PI¿s laboratory has screened rodent and human mast cells for the representation of TRP channel mRNA and protein. Mast cells contain TRPV2 protein, which as not been described to respond to lipid ligands. TRPV4 message, but not protein, has been detected in mast cells, and the diverse activation mechanisms for this channel may encompass cannabinoids. The mast cells that we have examined do not contain TRPV1, but do express the cannabinoid-sensitive TRPA1 channel. The experiments that we now propose will aim to dissect the regulation, and function, of TRPA1 in mast cells.