气道炎症时神经肽调控肥大细胞脱颗粒的机制研究

呼吸道变应性疾病的实质是炎症，其中肥大细胞（mast cell, MC）脱颗粒扮演重要角色。目前对MC脱颗粒的神经调控机制知之甚少。P物质（substance P,SP）能诱导MC脱颗粒，但机制不明。基于前期工作，我们假设呼吸道炎症时SP借助速激肽受体（NK-R）诱导嗜酸性细胞（eosinophil，EOS）调控MC实现非免疫性脱颗粒，同时通过影响MC表面IgE受体FcεRI调控免疫性脱颗粒，形成双重脱颗粒调控机制。我们将建立小鼠疾病模型，分离提纯EOS,制备骨髓肥大细胞（bone marrow-derived MC，BMMC)， 探讨SP诱导EOS调节MC脱颗粒机制；同时利用基因沉默技术分别制作不表达NK-R mRNA和不表达IgE受体FcεRImRNA的BMMC 细胞株，以野生型BMMC细胞株为对照，比较SP刺激对该细胞株脱颗粒及表达FcεRI的情况，以便阐明MC脱颗粒的一种新的机制。

Airway allergic diseases are closely related to inflammation. It is well-documented that the mast cell (MC) degranulation plays an important role in this inflammatory process. However, very little is known about the mechanism regarding the neural control of MC degranulation. Numerous studies have showed that the substance P(SP) released from terminals of sensory nerve can induce MC degranulation; nevertheless, the underlying mechanism is unclear. The purpose of this proposal is to explore a novel mechanism for neuropeptide-controlled MC degranulation. Based on our previous work, we propose that a "two-way" mechanism may be involved in the modulation of SP-induced MC degranulation. For non-immune degranulation, SP combined with neurokinin receptor (NK-R) modulates MC by inducing eosinophil (EOS). SP could also modulate the immune degranulation by influencing the expression of IgE receptor (FcεRI) on MC. To test our hypothesis, we will first develop a mice disease model. As a routine experiment procedure, the EOS will be isolated and purified, and the bone marrow-derived MC(BMMC) prepared. Furthermore, we will evaluate how the EOS stimulated by SP modulate the MC degranulation. By using gene silencing technic, two cell strains will be prepared, i.e., BMMCs with no expression of NK-R mRNA and no expression of FcεRImRNA corresponding to IgE receptor. Subsequently, MC degranulation as well as FcεRI expression of these two different BMMC strains to SP stimulus will be compared with wild type BMMC. In summary, these studies should provide us with better understanding of the mechanism of neuropeptide-controlled MC deranulation.