研究报告：缓激肽上调豚鼠肠道黏膜下神经丛环氧合酶2的表达

目的缓激肽和缓激肽B2受体在肠神经系统中起重要作用。缓激肽通常参与肠道的炎症反应和神经保护,这种作用取决于缓激肽诱导前列腺素的形成。环氧合酶1 (COX1)和环氧合酶2 (COX2)催化花生四烯酸转化为前列腺素。本研究旨在探讨缓激肽刺激对豚鼠肠神经前列腺素E2 (p GE2)释放和COX2表达的影响及信号机制。方法本文通过免疫荧光检测肠神经细胞中COX2与神经细胞标志物Anti-Hu和ch AT的表达;采用PCR及蛋白质印迹(Western blot)检测不同条件下缓激肽刺激对COX2表达的影响;使用缓激肽B1受体的选择性拮抗剂Leu-8和B2受体的选择性拮抗剂HOE-140,研究缓激肽影响COX2表达的信号机制;利用COX2选择性拮抗剂NS398和COX1拮抗剂FR12207,观察COX2在缓激肽诱导p EG2释放的作用。结果 COX2与神经细胞标志物Anti-Hu和ch AT在肠神经细胞上共同表达,缓激肽可通过B2受体诱导肠神经细胞COX2的表达。缓激肽刺激引起的肠神经细胞p GE2的释放与COX2表达升高密切相关。结论缓激肽通过B2R影响肠道黏膜下神经丛COX2的表达,肠道缓激肽...

Research: Bradykinin Upregulated The Expression of Cyclooxygenase-2 in The Submucosal Plexus of Enteric Nervous System of Guinea Pig

Objective Bradykinin and bradykinin B2 receptors (B2R) play important roles in the enteric nervous system. Bradykinin is usually involved in inflammation and neuroprotection, dependent on the bradykinin-induced formation of prostaglandins (PGs). Cyclooxygenase-1 (COX1) and cyclooxygenase-2 (COX2) catalyze the conversion of arachidonic acid to PGs. This study aimed to investigate the effect and the signaling mechanism of bradykinin stimulation on the release of prostaglandin E2 (pGE2) and the expression of COX2 in the enteric nervous system of guinea pigs. Methods Immunofluorescence was used to detecting the colocalization of COX2 with neural markers Anti-Hu and chAT in the primary cultured ileal submucosal plexus of guinea pigs. PCR and Western blot were used to detecting the effect of bradykinin evoking COX2 expression. Bradykinin B1 receptor (B1R) antagonist Leu-8 and B2R antagonist HOE-140 were preincubated before bradykinin stimulation. COX2 antagonist NS398 and COX1 antagonist FR12207 were used to observing the effect of bradykinin-induced pEG2 release. Results The results showed that COX2 was co-localized with neural markers Anti-Hu and chAT on ileal submucosal plexuses. Bradykinin induced COX2 expression was blocked by the B2R antagonist. The release of pGE2 by bradykinin stimulation in ileal submucosal plexuses was significantly decreased when incubating with the COX2 antagonist. Conclusion COX2 expression evoked by B2R signaling as an excitatory neurotransmitter in bradykinin stimulated pGE2 secretion, which provides a reasonable explanation for the role of bradykinin in intestinal inflammatory diseases.