Hannover Medical School, Department of Psychiatry, Social Psychiatry and Psychotherapy, Carl-Neuberg-Str. 1, 30625 Hannover, Germany.
Hannover Medical School, Department of Psychiatry, Social Psychiatry and Psychotherapy, Carl-Neuberg-Str. 1, 30625 Hannover, Germany.
Eur Neuropsychopharmacol. 2018 Jul;28(7):875-879. doi: 10.1016/j.euroneuro.2018.05.004. Epub 2018 Jun 2.
Impaired regulation of the hypothalamic-pituitary-adrenal (HPA) axis is substantially involved in several psychiatric disorders. Smoking interferes with HPA axis by activating proopiomelanocortin (POMC) neurons and thus stimulating the expression of POMC. The POMC transcript is processed into several peptide hormones, such as adrenocorticotropic hormone (ACTH) and alpha-melanocyte-stimulating hormone (alpha-MSH), that play a role in stress response and weight control. In alcohol dependence, POMC promoter methylation is associated with craving. Here, we describe evidence of altered POMC promoter methylation in smoking. To determine how tobacco dependence and its withdrawal affect POMC promoter-specific DNA methylation, we assessed blood samples of 36 tobacco dependent individuals at day 1, 7 and 14 of withdrawal compared to 41 healthy controls using direct bisulfite sequencing. We found that POMC promoter methylation is significantly higher in smokers than in non-smokers. Moreover, this methylation difference does not readapt within 14 days of abstinence. We offer two explanatory models: Smokers could have a higher methylation state before the onset of smoking and this premorbid status might be acquired by environmental factors in early life. Alternatively, smoking may activate POMC neurons and its protein expression. Therefore, increasing methylation status of its promoter might be an adjustment to keep homeostasis. In either way, altered POMC methylation in smokers seems to indicate an adaptation of stress signaling, thereby potentially serving as a marker for stress-related functions that support the addiction.
下丘脑-垂体-肾上腺(HPA)轴的调节受损与多种精神疾病密切相关。吸烟通过激活前阿黑皮素原(POMC)神经元,从而刺激 POMC 的表达,干扰 HPA 轴。POMC 转录本被加工成几种肽激素,如促肾上腺皮质激素(ACTH)和α-黑色素细胞刺激素(α-MSH),这些激素在应激反应和体重控制中发挥作用。在酒精依赖中,POMC 启动子甲基化与渴求有关。在这里,我们描述了吸烟改变 POMC 启动子甲基化的证据。为了确定烟草依赖及其戒断如何影响 POMC 启动子特异性 DNA 甲基化,我们使用直接亚硫酸氢盐测序法,在戒断第 1、7 和 14 天,比较了 36 名烟草依赖个体与 41 名健康对照者的血液样本,评估了 POMC 启动子的特定 DNA 甲基化。我们发现,吸烟者的 POMC 启动子甲基化明显高于非吸烟者。此外,这种甲基化差异在戒断 14 天内没有重新适应。我们提出了两种解释模型:吸烟者在开始吸烟前可能具有更高的甲基化状态,而这种发病前状态可能是由早期生活中的环境因素获得的。或者,吸烟可能激活 POMC 神经元及其蛋白表达。因此,增加其启动子的甲基化状态可能是维持体内平衡的一种调整。无论是哪种情况,吸烟者中 POMC 甲基化的改变似乎表明应激信号的适应,从而可能作为支持成瘾的应激相关功能的标志物。