Novel Synergism Between LTD4 and PGE2 Signaling in MC-medicated Inflammation

项目摘要 肥大细胞是哮喘的效应细胞，其激活可导致半胱氨酰白三烯的分泌 (Cys-Lts)和前列腺素(PGs)。巨噬细胞不仅分泌这些介质，而且还拥有受体 对他们来说，是为了感知他们的信号。半胱氨酸氨基转移酶是一种强有力的支气管收缩药、血管诱导剂 渗漏是呼吸道高反应性的增强剂，在哮喘等疾病中发挥重要作用 炎症性疾病。另一方面，前列腺素E2(PGE2)在哮喘领域的作用是 既是促炎又是抗炎的有争议的作用，主要取决于受体/S通过 它发挥了它的作用。我们的初步结果表明，Cys-LTS与PGE2具有协同作用 通过对MC(增强的钙流、c-Fos、COX-2、PGD2)的作用增强血管炎症 巨噬细胞炎性蛋白-1(-1；CCl))的产生。有趣的是，LTD4-PGE2的协同作用是 仅用CysLT1R拮抗剂(MK571/Singulair)和EP3拮抗剂(L-798)联合治疗而被阻断， 提示需要联合使用CysLT1R拮抗剂和EP3阻滞剂来治疗炎症。 哮喘。此外，PPAR抑制剂GW9662与PKG抑制剂KT5823和MEK一起抑制了这种协同作用 PD98059，提示PPAR、PKG和ERK在其中起作用。此外，LTD4和PGE2的协同作用也 增强DER致敏小鼠的肺部炎症(免疫细胞、杯状细胞的募集 化生，炎性转录上调)。根据这些初步数据，我们假设 LTD4有可能将PGE2信号从EP2/Gs/cAMP/PKA途径切换到EP3/GI/cGMP/PKG轴， 通过PPAR、COX-2和PGD2产生促炎信号和MC激活，随后增强 地塞米松致小鼠肺部炎症反应。我们将在以下具体目标中检验这一假设1) Cys-LT/PGE2协同诱导MC活化及PGD2机制的研究 PPAR的体外生产及其生理意义的研究 小鼠体内肺部炎症的相互作用，病理分析， 免疫反应的生理学和免疫学特征，并评估MC的贡献。 这些研究将对哮喘和过敏性疾病具有重要的病原学和治疗意义。 以及为开发和翻译未来的治疗分子提供基础 发炎。

Project Summary Mast cells (MCs) are effector cells in asthma and their activation causes secretion of cysteinyl leukotrienes (cys-LTs) and prostaglandins (PGs). MCs not only secrete these mediators, but they also possess receptors for them, to perceive their signals. Cys-LTs are potent bronchoconstrictors, powerful inducers of vascular leakage, potentiators of airway hyper-responsiveness and play an important role in asthma and other inflammatory disorders. On the other hand, Prostaglandin E2 (PGE2) function in the field of asthma is controversial acting both as pro as well as anti-inflammatory, depending mainly on the receptor/s through which it exerts its effect. Our preliminary results indicate that cys-LTs together with PGE2 synergistically potentiate vascular inflammation through their action on MCs (enhanced calcium flux, c-Fos, COX-2, PGD2 and Macrophage Inflammatory Protein-1 (MIP-1; CCL4)) generation. Interestingly, LTD4-PGE2 synergism is blocked only by combined treatment of CysLT1R antagonist (MK571/ singulair) and EP3 antagonist (L-798), suggesting the need for a combination of CysLT1R antagonists and EP3 blockers to treat inflammation in asthma. Further, PPAR inhibitor, GW9662 inhibited this synergy along with PKG inhibitor, KT5823 and MEK inhibitor PD98059, implicating a role for PPAR, PKG and Erk. Furthermore, LTD4+PGE2 synergism also potentiates pulmonary inflammation in der f sensitized mice (recruitment of immune cells, goblet cell metaplasia, up-regulation of inflammatory transcripts). Based on these preliminary data, we hypothesize that LTD4 has a potential to switch PGE2 signals from EP2/Gs/cAMP/PKA pathway to EP3/Gi/cGMP/PKG axis, generating pro-inflammatory signals and MC activation via PPAR, COX-2 and PGD2, followed by potentiating pulmonary inflammation in der f- challenged mice. We will test this hypothesis in the following specific aims 1) To determine the mechanism by which Cys-LT/PGE2 synergism induces MC activation and PGD2 production in vitro with focus on PPAR 2) To determine the physiological significance of cys-LT-PGE2 interactions in pulmonary inflammation in vivo in Der f-challenged mice, analyzing pathologic, physiologic, and immunologic signatures of the immune response and evaluate the contribution of MCs. These studies will carry substantial pathogenic and therapeutic implications for asthma and allergic diseases as well as provide the basis for development and translation of future therapeutic molecules that regulate inflammation.