Orio Laura, Alen Francisco, Pavón Francisco Javier, Serrano Antonia, García-Bueno Borja
Department of Psychobiology and Methods in Behavioral Science, Faculty of Psychology, Complutense University of Madrid, Madrid, Spain.
Red de Trastornos Adictivos (RTA), Instituto de Salud Carlos III (ISCIII), Madrid, Spain.
Front Mol Neurosci. 2019 Jan 9;11:490. doi: 10.3389/fnmol.2018.00490. eCollection 2018.
Neuroinflammation is a complex process involved in the physiopathology of many central nervous system diseases, including addiction. Alcohol abuse is characterized by induction of peripheral inflammation and neuroinflammation, which hallmark is the activation of innate immunity toll-like receptors 4 (TLR4). In the last years, lipid transmitters have generated attention as modulators of parts of the addictive process. Specifically, the bioactive lipid oleoylethanolamide (OEA), which is an endogenous acylethanolamide, has shown a beneficial profile for alcohol abuse. Preclinical studies have shown that OEA is a potent anti-inflammatory and antioxidant compound that exerts neuroprotective effects in alcohol abuse. Exogenous administration of OEA blocks the alcohol-induced TLR4-mediated pro-inflammatory cascade, reducing the release of proinflammatory cytokines and chemokines, oxidative and nitrosative stress, and ultimately, preventing the neural damage in frontal cortex of rodents. The mechanisms of action of OEA are discussed in this review, including a protective action in the intestinal barrier. Additionally, OEA blocks cue-induced reinstatement of alcohol-seeking behavior and reduces the severity of withdrawal symptoms in animals, together with the modulation of alcohol-induced depression-like behavior and other negative motivational states associated with the abstinence, such as the anhedonia. Finally, exposure to alcohol induces OEA release in blood and brain of rodents. Clinical evidences will be highlighted, including the OEA release and the correlation of plasma OEA levels with TLR4-dependent peripheral inflammatory markers in alcohol abusers. In base of these evidences we hypothesize that the endogenous release of OEA could be a homeostatic signal to counteract the toxic action of alcohol and we propose the exploration of OEA-based pharmacotherapies to treat alcohol-use disorders.
神经炎症是一个复杂的过程,涉及包括成瘾在内的许多中枢神经系统疾病的病理生理学。酒精滥用的特征是诱导外周炎症和神经炎症,其标志是先天免疫Toll样受体4(TLR4)的激活。在过去几年中,脂质递质作为成瘾过程部分环节的调节剂引起了关注。具体而言,生物活性脂质油酰乙醇胺(OEA)是一种内源性酰基乙醇胺,已显示出对酒精滥用有益的作用。临床前研究表明,OEA是一种有效的抗炎和抗氧化化合物,对酒精滥用具有神经保护作用。外源性给予OEA可阻断酒精诱导的TLR4介导的促炎级联反应,减少促炎细胞因子和趋化因子的释放、氧化应激和亚硝化应激,并最终防止啮齿动物额叶皮质的神经损伤。本文综述了OEA的作用机制,包括其在肠道屏障中的保护作用。此外,OEA可阻断线索诱导的觅酒行为恢复,并减轻动物戒断症状的严重程度,同时调节酒精诱导的抑郁样行为以及与戒酒相关的其他负性动机状态,如快感缺失。最后,暴露于酒精会诱导啮齿动物血液和大脑中OEA的释放。将强调临床证据,包括酒精滥用者中OEA的释放以及血浆OEA水平与TLR4依赖性外周炎症标志物的相关性。基于这些证据,我们假设OEA的内源性释放可能是一种稳态信号,以抵消酒精的毒性作用,并且我们建议探索基于OEA的药物疗法来治疗酒精使用障碍。