EP2 Receptor Signaling Pathways Regulate Classical Activation of Microglia
EP2 Receptor Signaling Pathways Regulate Classical Activation of Microglia
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DOI：
10.1074/jbc.m113.455816
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发表时间：
2013-03-29
影响因子：
4.8
通讯作者：
Dingledine, Ray
中科院分区：
文献类型：
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作者：
Quan, Yi;Jiang, Jianxiong;Dingledine, Ray
前列腺素E2（PGE（2））激活EP 2受体可促进神经退行性疾病中的脑炎症，但对此负责的途径尚不清楚。EP 2受体与G α偶联并增加cAMP，其与蛋白激酶A（PKA）和cAMP调节的鸟嘌呤核苷酸交换因子（Epacs）相关。在这里，我们研究了EP 2功能及其信号通路在大鼠小胶质细胞在其静息状态或经历经典的激活在体外治疗低浓度的脂多糖和干扰素-γ。真实的时间PCR显示PGE（2）对CXCL 10、TGF-β 1和IL-11的表达没有影响，并且加速了编码环氧合酶-2、诱导型NOS、IL-6和IL-1 β的mRNA的快速上调，但减弱了编码TNF-α、IL-10、CCL 3和CCL 4的mRNA的产生。EP 2激动剂布他前列素完全模拟了这些作用，但EP 1/EP 3激动剂17-苯基trinor PGE（2）或EP 4激动剂CAY 10598仅微弱模拟了这些作用，而EP 3/EP 1激动剂硫前列酮完全没有模拟这些作用，并通过环氧合酶-2，IL-6，IL-10和TNF-α的蛋白质测量得到证实。在静息的小胶质细胞中，布他前列素诱导cAMP形成，并改变炎症介质的mRNA表达，但蛋白质表达不变。PKA抑制剂H89对EP 2调节的炎症介质几乎没有影响，而Epac激活剂8-（4-氯苯硫基）-2 '-O-甲基腺苷3'，5 '-环单磷酸乙酰氧基甲酯模拟了所有的布他前列素作用。这些结果表明，EP 2活化在小胶质细胞的经典活化过程中起着复杂的免疫调节作用，并且Epac通路在此作用中是突出的。
Activation of EP2 receptors by prostaglandin E2 (PGE(2)) promotes brain inflammation in neurodegenerative diseases, but the pathways responsible are unclear. EP2 receptors couple to G alpha(s) and increase cAMP, which associates with protein kinase A (PKA) and cAMP-regulated guanine nucleotide exchange factors (Epacs). Here, we studied EP2 function and its signaling pathways in rat microglia in their resting state or undergoing classical activation in vitro following treatment with low concentrations of lipopolysaccharide and interferon-gamma. Real time PCR showed that PGE(2) had no effect on expression of CXCL10, TGF-beta 1, and IL-11 and exacerbated the rapid up-regulation of mRNAs encoding cyclooxygenase-2, inducible NOS, IL-6, and IL-1 beta but blunted the production of mRNAs encoding TNF-alpha, IL-10, CCL3, and CCL4. These effects were mimicked fully by the EP2 agonist butaprost but only weakly by the EP1/EP3 agonist 17-phenyl trinor PGE(2) or the EP4 agonist CAY10598 and not at all by the EP3/EP1 agonist sulprostone and confirmed by protein measurements of cyclooxygenase-2, IL-6, IL-10, and TNF-alpha. In resting microglia, butaprost induced cAMP formation and altered the mRNA expression of inflammatory mediators, but protein expression was unchanged. The PKA inhibitor H89 had little or no effect on inflammatory mediators modulated by EP2, whereas the Epac activator 8-(4-chlorophenylthio)-2'-O-methyladenosine 3',5'-cyclic monophosphate acetoxymethyl ester mimicked all butaprost effects. These results indicate that EP2 activation plays a complex immune regulatory role during classical activation of microglia and that Epac pathways are prominent in this role.