Metformin reduces morphine tolerance by inhibiting microglial-mediated neuroinflammation.
Metformin reduces morphine tolerance by inhibiting microglial-mediated neuroinflammation.
复制标题
二甲双胍通过抑制小胶质细胞介导的神经炎症来降低吗啡耐受性。
DOI：
10.1186/s12974-016-0754-9
复制
发表时间：
2016-11-17
影响因子：
9.3
通讯作者：
Liu W
中科院分区：
文献类型：
--
作者：
Pan Y;Sun X;Jiang L;Hu L;Kong H;Han Y;Qian C;Song C;Qian Y;Liu W
背景耐受性严重阻碍了吗啡的临床应用。因此，有必要研究其确切的机制和有效的治疗方法。脊髓内小胶质细胞的活化和神经炎症反应在吗啡耐受的发生和维持中起着关键作用。腺苷一磷酸激活激酶（AMPK）的激活与炎症性伤害感受的抑制有关。二甲双胍类抗糖尿病药物和AMPK激活剂具有潜在的抗炎作用。本研究评价二甲双胍抑制小胶质细胞活化和减轻吗啡镇痛耐受的作用及其机制。方法采用小胶质细胞系BV-2细胞和小鼠脑源性内皮细胞系bEnd 3细胞。用定量聚合酶链反应测定细胞因子的表达。Western blot和免疫组化检测细胞信号转导。CD-1小鼠使用tail-flick tests.ResultsWe发现，吗啡激活BV-2细胞，包括p38丝裂原活化蛋白激酶（p38 MAPK）磷酸化，促炎细胞因子，和Toll样受体-4（TLR-4）mRNA表达的上调，这是抑制二甲双胍的抗伤害和吗啡耐受性进行了评估。二甲双胍通过增加AMPK磷酸化抑制吗啡诱导的BV-2细胞活化，AMPK抑制剂化合物C可逆转该作用。此外，在BV-2细胞中，吗啡不影响细胞活力和抗炎细胞因子的mRNA表达。在bEnd 3细胞中，吗啡不影响白细胞介素1β（IL-1β）的mRNA表达，但可增加IL-6和肿瘤坏死因子α（TNF-α）的mRNA表达;这种作用可被二甲双胍抑制。吗啡也不影响TLR-4和趋化因子配体2（CCL 2）的mRNA表达。此外，二甲双胍的全身给药显着阻断吗啡诱导的小胶质细胞激活在脊髓中，然后衰减的慢性吗啡tolerance in mice. ConclusionsMetabolism的发展显着衰减吗啡镇痛耐受抑制吗啡诱导的小胶质细胞激活，通过增加AMPK磷酸化。
BackgroundTolerance seriously impedes the application of morphine in clinical medicine. Thus, it is necessary to investigate the exact mechanisms and efficient treatment. Microglial activation and neuroinflammation in the spinal cord are thought to play pivotal roles on the genesis and maintaining of morphine tolerance. Activation of adenosine monophosphate-activated kinase (AMPK) has been associated with the inhibition of inflammatory nociception. Metformin, a biguanide class of antidiabetic drugs and activator of AMPK, has a potential anti-inflammatory effect. The present study evaluated the effects and potential mechanisms of metformin in inhibiting microglial activation and alleviating the antinociceptive tolerance of morphine.MethodsThe microglial cell line BV-2 cells and mouse brain-derived endothelial cell line bEnd3 cells were used. Cytokine expression was measured using quantitative polymerase chain reaction. Cell signaling was assayed by western blot and immunohistochemistry. The antinociception and morphine tolerance were assessed in CD-1 mice using tail-flick tests.ResultsWe found that morphine-activated BV-2 cells, including the upregulation of p38 mitogen-activated protein kinase (p38 MAPK) phosphorylation, pro-inflammatory cytokines, and Toll-like receptor-4 (TLR-4) mRNA expression, which was inhibited by metformin. Metformin suppressed morphine-induced BV-2 cells activation through increasing AMPK phosphorylation, which was reversed by the AMPK inhibitor compound C. Additionally, in BV-2 cells, morphine did not affect the cell viability and the mRNA expression of anti-inflammatory cytokines. In bEnd3 cells, morphine did not affect the mRNA expression of interleukin-1β (IL-1β), but increased IL-6 and tumor necrosis factor-α (TNF-α) mRNA expression; the effect was inhibited by metformin. Morphine also did not affect the mRNA expression of TLR-4 and chemokine ligand 2 (CCL2). Furthermore, systemic administration of metformin significantly blocked morphine-induced microglial activation in the spinal cord and then attenuated the development of chronic morphine tolerance in mice.ConclusionsMetformin significantly attenuated morphine antinociceptive tolerance by suppressing morphine-induced microglial activation through increasing AMPK phosphorylation.