Morphine enhances microglial migration through modulation of P2X4 receptor signaling.
Morphine enhances microglial migration through modulation of P2X4 receptor signaling.
复制标题
DOI：
10.1523/jneurosci.4595-08.2009
复制
发表时间：
2009-01-28
期刊：
影响因子：
--
通讯作者：
DeLeo JA
中科院分区：
文献类型：
--
作者：
Horvath RJ;DeLeo JA
阿片类药物虽然是治疗疼痛的基础，但其疗效受到包括耐受性和痛觉过敏在内的副作用的限制。使用体外培养系统，我们报告了吗啡通过μ-阿片和P2 X4受体之间的新型相互作用增加小胶质细胞迁移，这依赖于PI 3 K/Akt通路的激活。吗啡在100 nm增强迁移的原代小胶质细胞向腺苷二磷酸的257，247，301，394，和345%后，2，6，12，24，和48小时的刺激，分别。这种阿片依赖性迁移作用可被纳洛酮抑制，并通过使用选择性激动剂和拮抗剂证实为μ-阿片受体依赖性。P2 X1 - 3，5 -7拮抗剂PPADS [磷酸吡哆醛-6-偶氮（苯-2，4-二磺酸）]对小胶质细胞迁移没有影响;然而，P2 X1 -7拮抗剂TNP-ATP [2′，3 ′-O-（2，4，6-三硝基苯基）-ATP]抑制吗啡诱导的迁移，表明P2 X4受体介导的作用。PI 3 K抑制剂wortmannin和LY 294002减少吗啡诱导的小胶质细胞迁移。小胶质细胞标记物Iba 1蛋白和P2 X4受体表达在吗啡刺激6、12、24和48 h后显著增加。总之，这些结果提供了两个阶段的吗啡对小胶质细胞的影响的证据。初始阶段在几分钟内发生，涉及PI 3 K/Akt通路激活并导致急性增强的迁移。较长期的阶段发生在几个小时的数量级，并涉及增加表达的Iba 1和P2 X4受体蛋白，这赋予了一个promigration表型，并与更大的迁移。这些数据提供了第一个必要的步骤，支持小胶质细胞迁移作为一个有吸引力的目标，预防或减轻吗啡诱导的副作用，包括耐受性和痛觉过敏。
Opioids, although fundamental to the treatment of pain, are limited in efficacy by side effects including tolerance and hyperalgesia. Using an in vitro culture system, we report that morphine increased microglial migration via a novel interaction between μ-opioid and P2X4 receptors, which is dependent upon PI3K/Akt pathway activation. Morphine at 100 nm enhanced migration of primary microglial cells toward adenosine diphosphate by 257, 247, 301, 394, and 345% following 2, 6, 12, 24, and 48 h of stimulation, respectively. This opioid-dependent migration effect was inhibited by naloxone and confirmed to be μ-opioid receptor-dependent through the use of selective agonists and antagonists. PPADS [pyridoxal phosphate-6-azo(benzene-2,4-disulfonic acid)], a P2X1–3,5–7 antagonist, had no effect on microglial migration; however, TNP-ATP [2′,3′-O-(2,4,6-trinitrophenyl)-ATP], a P2X1–7 antagonist, inhibited morphine-induced migration, suggesting a P2X4 receptor-mediated effect. The PI3K inhibitors wortmannin and LY294002 decreased morphine-induced microglial migration. Iba1 protein, a microglial marker, and P2X4 receptor expression were significantly increased after 6, 12, 24, and 48 h of morphine stimulation. Together, these results provide evidence for two phases of morphine effects on microglia. The initial phase takes place in minutes, involves PI3K/Akt pathway activation and leads to acutely enhanced migration. The longer-term phase occurs on the order of hours and involves increased expression of Iba1 and P2X4 receptor protein, which imparts a promigratory phenotype and is correlated with even greater migration. These data provide the first necessary step in supporting microglial migration as an attractive target for the prevention or attenuation of morphine-induced side effects including tolerance and hyperalgesia.