McDonough Jennifer, Singhal Naveen K, Getsy Paulina M, Knies Katherine, Knauss Zackery T, Mueller Devin, Bates James N, Damron Derek S, Lewis Stephen J
Department of Biological Sciences, Kent State University, Kent, OH, United States.
Department of Pediatrics, Case Western Reserve University, Cleveland, OH, United States.
Front Pharmacol. 2024 Aug 30;15:1416701. doi: 10.3389/fphar.2024.1416701. eCollection 2024.
We have reported that D,L-thiol esters, including D-cysteine ethyl ester (D-CYSee), are effective at overcoming opioid-induced respiratory depression (OIRD) in rats. Our on-going studies reveal that co-injections of D-CYSee with multi-day morphine injections markedly diminish spontaneous withdrawal that usually occurs after cessation of multiple injections of morphine in rats. Chronically administered opioids are known (1) to alter cellular redox status, thus inducing an oxidative state, and (2) for an overall decrease in DNA methylation, therefore resulting in the transcriptional activation of previously silenced long interspersed elements (LINE-1) retrotransposon genes. The first objective of the present study was to determine whether D-CYSee and the one carbon metabolism with the methyl donor, betaine, would maintain redox control and normal DNA methylation levels in human neuroblastoma cell cultures (SH-SY5Y) under overnight challenge with morphine (100 nM). The second objective was to determine whether D-CYSee and/or betaine could diminish the degree of physical dependence to morphine in male Sprague Dawley rats. Our data showed that overnight treatment with morphine reduced cellular GSH levels, induced mitochondrial damage, decreased global DNA methylation, and increased LINE-1 mRNA expression. These adverse effects by morphine, which diminished the reducing capacity and compromised the maintenance of the membrane potential of SH-SY5Y cells, was prevented by concurrent application of D-CYSee (100 µM) or betaine (300 µM). Furthermore, our data demonstrated that co-injections of D-CYSee (250 μmol/kg, IV) and to a lesser extent, betaine (250 μmol/kg, IV), markedly diminished the development of physical dependence induced by multi-day morphine injections (escalating daily doses of 10-30 mg/kg, IV), as assessed by the lesser number of withdrawal phenomena elicited by the injection of the opioid receptor antagonist, naloxone (1.5 mg/kg, IV). These findings provide evidence that D-CYSee and betaine prevent the appearance of redox alterations and epigenetic signatures commonly seen in neural cells involved in opioid physical dependence/addiction, and lessen development of physical dependence to morphine.
我们曾报道，包括D-半胱氨酸乙酯（D-CYSee）在内的D，L-硫酯能有效克服大鼠体内阿片类药物引起的呼吸抑制（OIRD）。我们正在进行的研究表明，将D-CYSee与多日吗啡注射同时给药，能显著减轻大鼠在多次注射吗啡后停药时通常会出现的自发戒断反应。长期使用阿片类药物已知会：（1）改变细胞氧化还原状态，从而诱导氧化状态；（2）导致DNA甲基化总体水平下降，进而导致先前沉默的长散在元件（LINE-1）逆转座子基因转录激活。本研究的首要目标是确定D-CYSee以及与甲基供体甜菜碱的一碳代谢，在吗啡（100 nM）过夜刺激下，是否能在人神经母细胞瘤细胞培养物（SH-SY5Y）中维持氧化还原控制和正常的DNA甲基化水平。第二个目标是确定D-CYSee和/或甜菜碱是否能减轻雄性Sprague Dawley大鼠对吗啡的身体依赖程度。我们的数据表明，吗啡过夜处理会降低细胞内谷胱甘肽（GSH）水平，诱导线粒体损伤，降低整体DNA甲基化水平，并增加LINE-1 mRNA表达。同时应用D-CYSee（100 μM）或甜菜碱（300 μM）可预防吗啡的这些不良反应，这些反应削弱了SH-SY5Y细胞的还原能力并损害了膜电位的维持。此外，我们的数据表明，同时注射D-CYSee（250 μmol/kg，静脉注射）以及程度较轻的甜菜碱（250 μmol/kg，静脉注射），能显著减轻多日吗啡注射（每日递增剂量为10 - 30 mg/kg，静脉注射）诱导的身体依赖的发展，这通过注射阿片受体拮抗剂纳洛酮（1.5 mg/kg，静脉注射）引发的戒断现象数量较少得以评估。这些发现提供了证据，表明D-CYSee和甜菜碱可防止在涉及阿片类药物身体依赖/成瘾的神经细胞中常见的氧化还原改变和表观遗传特征的出现，并减轻对吗啡身体依赖的发展。
