ORIGINAL RESEARCH article

Front. Pharmacol., 30 August 2024

Sec. Translational Pharmacology

Volume 15 - 2024 | https://doi.org/10.3389/fphar.2024.1416701

The epigenetic signatures of opioid addiction and physical dependence are prevented by D-cysteine ethyl ester and betaine

  • 1. Department of Biological Sciences, Kent State University, Kent, OH, United States

  • 2. Department of Pediatrics, Case Western Reserve University, Cleveland, OH, United States

  • 3. Department of Anesthesia, University of Iowa Hospitals and Clinics, Iowa City, IA, United States

  • 4. Department of Pharmacology, Case Western Reserve University, Cleveland, OH, United States

  • 5. Functional Electrical Stimulation Center, Case Western Reserve University, Cleveland, OH, United States

Abstract

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.

Introduction

Opioids alter DNA and histone methylation patterns, and gene expression, which contributes to their physiological action and the underlying addictive nature of these drugs (Trivedi et al., 2014a; Trivedi et al., 2014b; Trivedi and Deth, 2015; De Sa Nogueira et al., 2018). Methylation of DNA and histones can cause heritable epigenetic changes in chromatin structure that activate or silence gene transcription. While some epigenetic marks are stable, others are more dynamic allowing cells to respond rapidly to changing metabolic or environmental signals (Suzuki and Bird, 2008; Ma et al., 2009; Ito et al., 2010; Gut and Verdin, 2013; Smith and Meissner, 2013; Salminen et al., 2014). The mechanisms associated with opioid-induced epigenetic changes involve inhibition of activity and ultimate degradation of the excitatory amino acid transporter 3 (EAAT3), which is required for uptake of the amino acid, L-cysteine, into neurons (Trivedi et al., 2014a; Trivedi et al., 2014b; Trivedi and Deth, 2015; De Sa Nogueira et al., 2018). L-cysteine exerts a variety of effects in cells, including conversion to the antioxidant tripeptide, glutathione (GSH, γ-glutamyl-cysteinyl-glycine), which maintains redox homeostasis in cells (Lu, 2013; Jenkins et al., 2021). Neurons are particularly sensitive to L-cysteine deficiency because flux, via transulfuration pathways, which convert L-homocysteine to GSH, are extremely limited due to low conversion of L-cystathionine to L-cysteine. Neurons rely on L-cysteine transport from astrocytes via the EAAT3 transporter (Trivedi and Deth, 2015; Trivedi et al., 2015). As a direct consequence of opioid exposure (Figure 1), neurons become deficient in L-cysteine and GSH, which results in an inability to maintain redox control (Trivedi et al., 2014a; Trivedi et al., 2014b; Trivedi and Deth, 2015; Trivedi et al., 2015).

FIGURE 1

Impaired redox control in cells plays an important role in the expression of opioid withdrawal signs (Xu et al., 2006), thus therapeutics that maintain redox homeostasis (e.g., GSH levels) may be beneficial for treating opioid use disorder (OUD). Redox control and DNA/histone methylation reactions are closely linked to intracellular methionine metabolism (Figure 1). In the methionine cycle, methionine is converted to S-adenosyl-methionine (SAM), which is the methyl donor for most methylation reactions (e.g., DNA and histone methylation) within cells (Bottiglieri, 2013; Froese et al., 2019). The B12-dependent methionine synthase (MTR in Figure 1) is sensitive to inhibition by reactive oxygen species (ROS) via the oxidation of B12 (cobalamin) (Nicolaou et al., 1994; Nicolaou et al., 1996; Mukherjee and Brasch (2011). With opioid exposure, the oxidation of MTR contributes to decreased levels of the methyl donor SAM for the epigenetic regulation of chromatin (Trivedi and Deth, 2015; Trivedi et al., 2015). SAM is converted to S-adenosyl-homocysteine (SAH) after donating a methyl group. Under oxidative-stress states, the build-up SAH and homocysteine, inhibits the activities of methyltransferase enzymes (Cantoni, 1975; Xu et al., 2015). The perturbation of redox control and SAM/SAH ratio (i.e., methylation potential), could readily explain the reduction in DNA and histone methylation by opioids (Sun et al., 2012; Trivedi et al., 2014a; Trivedi et al., 2014b). Changes in the SAM/SAH ratio lead to changes in the methylation status of downstream substrates, including DNA and histones, and results in aberrant gene expression (Mentch et al., 2015). Morphine treatment of human neuroblastoma cells causes overall decreases in DNA methylation, which results in the transcriptional activation of previously silenced long interspersed elements (LINE-1) retrotransposon genes (Trivedi et al., 2014a; Trivedi et al., 2014b). It should be noted that opioids also alter the expression of genes involved in neurotransmission, synaptic plasticity, and GSH metabolism (McClung et al., 2005; Tapocik et al., 2013).

We have reported that L-cysteine ethyl ester (L-CYSee), and related L,D-thiolesters (Mendoza et al., 2013; Gaston et al., 2021; Jenkins et al., 2021; Getsy et al., 2022a; Getsy et al., 2022b; Lewis et al., 2022) and L-S-nitrosthiols (Getsy et al., 2022c; Getsy et al., 2022d), overcome the deletrious actions of fentanyl and morphine on breathing, arterial blood-chemistry and alveolar gas exchange in rats, while not markedly affecting the analgesic/sedative actions of the opioids. We have also demonstrated that D-cysteine ethyl ester (D-CYSee) mimics the effects of L-CYSee and chose to use this compound because it is likley to have less off-target effects than L-CYSee (Getsy et al., 2022c; Getsy et al., 2022d). Although we have not determined the mechanisms by which D-CYSee or other D,L-thiolesters reverse opioid-induced respiratory depression (OIRD), we reported that the free radical and superoxide anion scavenger, Tempol, also blunted fentanyl- and morphine-induced OIRD (Baby et al., 2021a; Baby et al., 2021b). As such, it is possible that preventing/reversing opioid-induced changes in oxidation-reduction status of neurons may be of benefit in overcoming OIRD and physical dependence to opioids. In this study, our first objective was to test whether enhancing redox control with D-CYSee and the one-carbon metabolite with a methyl donor, betaine (Ueland et al., 2005; Chen and Murata, 2008; Lever and Slow, 2010; Ueland, 2011; Aramburu et al., 2014; Kumar et al., 2016; Knight et al., 2017; Zhao et al., 2010; Ohnishi et al., 2019; Arumugam et al., 2021) (Figure 2 for chemical structures), would maintain redox control and DNA methylation levels in human SH-SH5Y neuroblastoma cells (Singhal et al., 2015; Brown et al., 2016) that were challenged overnight with morphine (see Figure 3 for potential steps). We chose to study human SH-SH5Y neuroblastoma cells to allow comparisons to the extensive findings about redox-dependent pathways in these cells (Núñez et al., 2004; Tirmenstein et al., 2005; Aguirre et al., 2007; Dias et al., 2014; Wang et al., 2019; Mistry et al., 2020), and the mechanisms of action of agents that modify the cell signaling effects of opioids in these cells (Trivedi et al., 2014a; Trivedi et al., 2014b; Trivedi et al., 2015; Trivedi and Deth, 2015).

FIGURE 2

FIGURE 3

The second objective was to determine whether intravenous co-injections of D-CYSee or betaine modified the development of physical dependence to morphine in male Sprague Dawley rats as assessed by the strength of the withdrawal responses elicited by the injection of the opioid receptor antagonist, naloxone HCl (NLX). The behavioral phenomena included the occurrence of jumping (all four paws off the floor), wet dog-like shakes (WDS), rearing on hind legs (rears), episodes of fore-paw licking (FPL), circling (full 360° rotation), writhing (fully body contortion) and sneezing (abrupt expulsion of air). The other recorded parameters were drops in body temperature and body weight. All responses are classic signs of NLX-induced responses in morphine-dependent rats (Laska and Fennessy, 1976; Hutchinson et al., 2007; Morgan and Christie, 2011; Nielsen and Kreek, 2012).

Materials and methods

Permissions, rats, and surgical procedures

All studies were carried out in strict accordance with the NIH Guide for Care and Use of Laboratory Animals (NIH Publication No. 80-23) revised in 1996, and in strict compliance with the ARRIVE (Animal Research: Reporting of In Vivo Experiments) guidelines (http://www.nc3rs.org.uk/page. asp? id = 1,357). All protocols involving the use of rats were approved by Animal Care and Use Committees of Kent State University and Case Western Reserve University. Adult male Sprague Dawley rats were purchased from ENVIGO (Madison, WI, USA). They were given 5 days to recover from transportation before surgery. All rats received an indwelling jugular vein catheter (PE-10 connected to PE-50) under 2%–3% isoflurane anesthesia as described previously (Gaston et al., 2021; Getsy et al., 2022f). The catheter was then exteriorized at the back of the neck and all wounds were closed. The rats were given 3 days to recover from the surgeries. The venous catheters were flushed with 0.3 mL of phosphate-buffered saline (0.1 M, pH 7.4) 3–4 h before commencement of each of the studies. All studies were done in a quiet room with relative humidity of 50% ± 2% and temperature of 21.3°C ± 0.2°C. (+)-Morphine sulfate was obtained from Baxter Healthcare (Deerfield, IL, USA). D-CYSee HCl powder was obtained from ChemImpex (Wood Dale, IL). D-cysteine, betaine, and naloxone HCl were obtained from Sigma-Aldrich (St. Louis, MO, USA). Full step by step instructions with detailed diagrams for the above surgeries and vascular catherizations can be found at https://www.criver.com/products-services/research-models-services/preconditioning-services/rodent-surgery/vascular-catheterizations?region=3601.

Injection protocols

All co-injections started at 8 a.m. and 8 p.m. except for the final injection which was given at 2 p.m. Each group consisted of nine adult male Sprague Dawley rats. Day 1: two injections of morphine (10 mg/kg, IV). Day 2: two injections of morphine (15 mg/kg,IV). Day 3: two injections of morphine (20 mg/kg, IV). Day 4: two injections of morphine (25 mg/kg,IV). Day 5: two injections of morphine (30 mg/kg, IV). One group of rats received injection of vehicle (saline) either 15 min (n = 5) or 5 min (n = 4) prior to the injection of morphine. Other groups of rats (n = 9 rats per group) received co-injections of a 250 μmol/kg dose of (a) betaine (29.3 mg/kg, IV), (b) D-cysteine (30.3 mg/kg, IV), or (c) D-CYSee (46.5 mg/kg, IV) with morphine. Rats were placed in clear plastic boxes immediately after the last set of co-injections and allowed 60 min to acclimatize. At 60 min, all rats received an injection of NLX (1.5 mg/kg, IV) and the NLX-precipitated withdrawal phenomena were recorded over a 90 min period by three observers who were blind to the drug-administration protocols.

Tissue culture and redox levels

Human SH-SH5Y neuroblastoma cell lines were maintained in DMEM/F12 (Sigma-Aldrich, St Louis, MO) supplemented with 10% fetal bovine serum (Atlanta Biologicals, Atlanta, GA), 50 μg/mL penicillin, and 50 μg/mL streptomycin (Corning, Corning, NY) at 37°C in a humidified CO2 incubator. Cells were grown in 10 cm Petri dishes in confluence up to 90%. Cells were treated overnight with morphine (100 nM), D-CYSee (100 µM), betaine (300 µM), morphine (100 nM) + D-CYSee (100 µM) or morphine (100 nM) + betaine (300 µM). GSH levels (ng/mL) were measured with a GSH kit (Abcam, Cambridge, United Kingdom) according to manufacturer’s instructions from 4 separate experiments. A standard curve was constructed to determine actual GSH levels with absorbance units at each concentration being 0 (0 ng/mL), 0.242 (200 ng/mL), 0.549 (400 ng/mL), 1.207 (600 ng/mL), 1.666 (800 ng/mL) and 1.837 (1,000 ng/mL). Mitochondrial membrane potential was measured in human SH-SY5Y neuroblastoma cells by measuring JC-1 (5,50,6,60-tetra-chloro-1,10,3,30-tetraethylbenzimidazolylcarbocyanine iodide) fluorescence as described by Chen et al. (2019). In the normal cells, JC-1 exists as a monomer in the cytosol (green) and also accumulates as aggregates (red) in mitochondria induced by higher mitochondrial membrane potential. In apoptotic and necrotic cells, JC-1 exists in monomeric form and stains the cytosol green. As such, the red fluorescence denotes healthy mitochondria with intact membrane potential, whereas the green fluorescence denotes damaged mitochondria with altered membrane potential. Quantitation of red and green fluorescence and red/green fluorescence ratio denoting healthy/damaged mitochondria was measured in at least 3 separate treatments using a Tecan Safire5 microplate reader.

DNA methylation studies

Human SH-SY5Y neuroblastoma cells were treated overnight (20 h) with morphine (100 nM), D-CYSee (100 μM), betaine (300 μM), morphine (100 nM) + D-CYSee (100 μM) or morphine (100 nM) + betaine (300 μM). Global DNA methylation levels were measured (5-methylcytosine (5-mC)/100 ng DNA) with MethylFlash Methylated DNA Quantification Kits (Epigentek, Farmingdale, NY) from at least 3 separate treatments.

Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR)

Levels of LINE-1 RNA were measured by qRT-PCR with gene specific primers as described by Trivedi et al. (2014a, 2014b). Total RNA was isolated from SH-SY5Y cells treated overnight (20 h) with morphine (100 nM), D-CYSee (100 μM, betaine (300 μM), morphine (100 nM) + D-CYSee (100 μM) or morphine (100 nM) + betaine (300 μM) using the TRIzol reagent (Thermo Fischer Scientific, Waltham, MA). The samples were t purified on Quick-RNA MiniPrep Plus kit columns (Zymo Research, Irvine, CA). qRT-PCR was performed in triplicate with Brilliant III Ultra-Fast SYBR-Green (Agilent Technologies, Santa Clara, CA) and a MaxPro3000 Real Time PCR system (Agilent Technologies, Santa Clara, CA). Data was collected from 3 separate cell preparations. Relative gene expression was calculated with the 2−ΔΔCt method after normalization to β-actin levels.

Data analyses

All data were analyzed using one-way and two-way ANOVA followed by Bonferroni corrections for multiple comparisons between means using the error mean square terms from each ANOVA analysis (Wallenstein et al., 1980; Ludbrook, 1998; McHugh, 2011) as detailed previously (Getsy et al., 2023a; Getsy et al., 2023b). A p < 0.05 value denoted the initial level of statistical significance that was modified according to the number of comparisons between means as described by Wallenstein et al. (1980). The modified t-statistic is t = (mean group 1 - mean group 2)/[s x (1/n1 + 1/n2)1/2] where s2 = the mean square within groups term from the ANOVA (the square root of this value is used in the modified t-statistic formula) and n1 and n2 are the number of rats in each group under comparison. Based on an elementary inequality called Bonferroni’s inequality, a conservative critical value for modified t-statistics obtained from tables of t-distribution using a significance level of P/m, where m is the number of comparisons between groups to be performed (Winer, 1971). The degrees of freedom are those for the mean square for within group variation from the ANOVA table. The critical Bonferroni value is not found in conventional tables of the t-distribution, but can be approximated from tables of the normal curve by t = z + (z + z3)/4n, with n being the degrees of freedom and z being the critical normal curve value for P/m. The Bonferroni procedure provides critical values that are lower than those of other procedures when the number of comparisons can be limited, and will be slightly larger than those of other procedures if many comparisons are made (Wallenstein et al., 1980). Statistical analyses were performed with the aid of GraphPad Prism software (GraphPad Software, Inc., La Jolla, CA). All summary data are presented as mean ± SEM.

Results

Effects of D-CYSee and betaine on GSH levels and mitochondria after opioid exposure

Opioids decrease L-cysteine uptake, resulting in decreased levels of reduced glutathione (GSH) that leave neurons vulnerable to oxidative insults. As summarized in Figure 4, overnight incubation with betaine (300 μM) or D-CYSee (100 μM) did not alter GSH levels in human SH-SY5Y cells, whereas morphine (100 nM) produced a substantial decrease in GSH levels. Co-incubation with betaine (300 μM) prevented morphine (100 nM) from decreasing GSH levels. D-CYSee (100 μM) also overcame the ability of morphine (100 nM) to depress GSH levels. In fact, GSH levels were actually higher than control levels in cells co-incubated with morphine and D-CYSee. We also tested the effects of D-CYSee and betaine on mitochondrial membrane potential in human SH-SY5Y neuroblastoma cells by measuring JC-1 fluorescence. Morphine reduced membrane potential by 30% in neuroblastoma cells. D-CYSee and betaine were equally effective in restoring mitochondrial membrane potential during morphine treatment (Figure 5). As such, it is evident that D-CYSee and betaine maintain redox homeostasis and protect mitochondria from opioid-induced toxicity.

FIGURE 4

FIGURE 5

D-CYSee and betaine reverse opioid mediated reductions in global levels of DNA methylation and restore appropriate gene silencing

We demonstrate that D-CYSee and betaine reverse morphine-induced changes in global DNA methylation. Human SH-SY5Y neuroblastoma cells were treated with 100 nM morphine overnight and, as seen in Figure 6A, morphine reduced global DNA methylation. Methylation levels were restored in cells co-treated overnight with D-CYSee (100 μM) or betaine (300 μM). We then determined the effects of D-CYSee and betaine on morphine-induced changes in LINE-1 RNA expression. To determine whether the reductions in 5-mC shown in Figure 6A, which silences transcription, effected the expression of the LINE-1 gene, we measured levels of LINE-1 RNA by qRT-PCR. As seen in Figure 6B, LINE-1 RNA levels were increased by over 2-fold with morphine treatment and these RNA levels were restored to control levels with D-CYSee or betaine.

FIGURE 6

D-CYSee and betaine diminish the development of physical dependence to morphine

NLX elicited a pronounced series of behaviors (Figure 7A) and falls in body weight (Figure 7B) and body temperature (Figure 7C) in rats that received co-injections of morphine + vehicle. These NLX-induced responses were reduced in rats that received co-injections of betaine and markedly reduced in rats co-injected with D-CYSee, but not D-cysteine. As seen in Table 1, body temperature was equally elevated 60 min after the last set of co-injections of morphine + vehicle or morphine + D-cysteine (Pre-NLX). This hyperthermia was less in rats co-injected with morphine + betaine and markedly reduced in those co-injected with morphine + D-CYSee. As also seen in Table 1, body weight was equally reduced 60 min after the last set of co-injections of morphine + vehicle or morphine + D-cysteine (Pre-NLX). There was no reduction in the body weights of rats co-injected with morphine + betaine and morphine + D-CYSee, instead an increase in body weight was observed at this timepoint (Pre-NLX) compared to their starting weights (Pre values). NLX elicited pronounced falls in body weights in the morphine + vehicle and morphine + D-cysteine treatment groups. The NLX-induced falls in body weight were less in the rats that received morphine + betaine, and markedly less in the rats that received morphine + D-CYSee.

FIGURE 7

TABLE 1

Body temperature (°C)Actual valuesΔChange (°C)
EmulsionInfusionInjectionPrePre-NLXPost-NLXPre-NLX vs. preNLX response
MorphineVehicleNLX37.4 ± 0.138.4 ± 0.136.8 ± 0.2+0.96 ± 0.10*−1.63 ± 0.15*
MorphineD-cysteineNLX37.5 ± 0.138.5 ± 0.236.8 ± 0.3+1.04 ± 0.08*−1.77 ± 0.16*
MorphineD-CYSeeNLX37.5 ± 0.137.8 ± 0.137.4 ± 0.2+0.26 ± 0.06*,†−0.39 ± 0.04*,†
MorphineBetaineNLX37.5 ± 0.138.1 ± 0.137.2 ± 0.1+0.58 ± 0.06*,†,‡−0.93 ± 0.11*,†,‡
Body Weight (grams)Actual ValuesΔChange (grams)
EmulsionInfusionInjectionPrePre-NLXPost-NLXPre-NLX vs. PreNLX response
MorphineVehicleNLX331 ± 2.1320 ± 2.0307 ± 1.8−10.8 ± 1.1*−13.4 ± 0.9*
MorphineD-CysteineNLX334 ± 1.6323 ± 1.3308 ± 2.1−11.1 ± 0.7*−14.4 ± 1.4*
MorphineD-CYSeeNLX333 ± 1.7342 ± 2.0338 ± 2.0+9.2 ± 1.0*,†−4.0 ± 0.7*,†
MorphineBetaineNLX334 ± 1.4336 ± 1.7327 ± 2.3+2.1 ± 0.8†,‡−8.3 ± 1.1*,†,‡

Changes in body temperature and body weight elicited by the injection of naloxone HCl in the four treatment groups.

Responses elicited by the acute injection of naloxone HCl (NLX, 1.5 mg/kg, IP) in rats that received co-injections of morphine plus vehicle (300 μL/kg, IV), D-cysteine, D-cysteine ethyl ester (D-CYSee), or betaine (250 μmol/kg, IV). There were nine rats in each group. The data are presented as mean ± SEM.

*p < 0.05, significant response from Pre-values.

p < 0.05, D-cysteine, D-CYSee, or betaine versus vehicle.

p < 0.05, betaine versus D-CYSee.

Discussion

Trivedi et al. (2014a, 2014b) provided compelling evidence that morphine induced dependence/addiction involves redox-based changes in global DNA methylation and retrotransposon transcription via the inhibition of excitatory amino acid transporter type 3 (EAA3)-mediated uptake of cysteine into brain neurons. Some steps arising from studies of Trivedi et al. (2014a), Trivedi et al. (2014b) and others (Lin et al., 2001; Ikemoto et al., 2002; Mao et al., 2002; Xu et al., 2003; 2006; Christie, 2008; Yang et al., 2008; Wang et al., 2009; Daijo et al., 2011Gutowicz et al., 2011; Liu et al., 2011; Maze and Nestler, 2011; Lim et al., 2012; Sun et al., 2012; Browne et al., 2020) appear to involve (1) morphine attenuation of L-cysteine uptake into neurons by G-protein-dependent decrease in EAA3 expression and function, (2) reductions in intracellular levels of L-cysteine, L-glutathione and methylation index (SAM/SAH ratio, S-adenosyl-methionine/S-adenosyl-homocysteine), (3) reduced methylation of global CpG (regions of DNA in which a cytosine nucleotide is followed by a guanine nucleotide in linear base sequence along the 5′→ 3′direction), and decreased CpG methylation of long interspersed nuclear element - 1 (LINE-1) retrotransposon regulatory regions, (4) activation of transcription of previously silenced LINE-1 gene [see Figure 5 of Trivedi et al. (2014a)]. It occurred to us that co-administration of cell-penetrant L,D-thiolesters, such as L- or D-CYSee or the methyl donor, betaine, may be able to prevent the redox changes associated with a perturbation of DNA methylation and gene expression in neurons.

The present study found that overnight exposure to morphine greatly reduced intracellular levels of GSH in human SH-SY5Y neuroblastoma cells. These findings are consistant with substantial evidence that opioids/opioid peptides decrease the levels of GSH in neuronal, non-neuronal cells and organelles by a number of mechanisms (Moussa and el-Beih, 1972; Eklöw-Låstbom et al., 1986; Skoulis et al., 1989; Goudas et al., 1999; Guzmán et al., 2009; Deb and Das, 2011; Abdel-Zaher et al., 2013a; Abdel-Zaher et al., 2013b; Trivedi et al., 2014a; Trivedi et al., 2014b, Trivedi et al., 2015; Trivedi et al., 2016; Trivedi and Deth, 2015; Samikkannu et al., 2015; Yun et al., 2015; Yun et al., 2017; Chen et al., 2019; Shibani et al., 2019; Osmanlıoğlu et al., 2020; Mozafari et al., 2022), including decreased glutathione synthase activity (Samikkannu et al., 2015), increased glutathione peroxidase activity (Mozafari et al., 2022), and formation of glutathione conjugates, such as formyl glutathione (Eklöw-Låstbom et al., 1986). GSH is present in all mammalian cells and is vital to cell health (Townsend et al., 2003; Dwivedi et al., 2020). The presence of a sulfhydryl (SH) group confers potent antioxidant efficacy to GSH by, for example, its interactions with reactive oxygen and nitrogen species (Keszler et al., 2010; Mailloux et al., 2013) in which two molecules of GSH dimerize via disulfide linkage to form GSSG (glutathione disulfide) Mailloux et al., 2013. The reduced (GSH) and oxidized disulfide form (GSSG) are readily inter-convertible, with reduced GSH being the predominant form in healthy cells (Lu, 2013). GSH acts in coordination with other redox-active agents, such as α-lipoic acid and nicotinamide adenosine diphosphate (NADPH), to regulate intra-cellular redox status (Shen et al., 2005). GSH is converted to GSSG by glutathione peroxidase, whereas GSSG is converted to GSH by glutathione reductase (Knollema et al., 1996; Lubos et al., 2011). The GSH-GSSG cycle is involved in intracellular processses including (1) conversion of hydrogen peroxide (H2O2) to water and oxygen, (2) maintaining cell redox/antioxidant status, (3) detoxification of xenobiotic agents, (4) maintaining bioavailable pools of L-cysteine, (5) production of iron-sulfur (Fe–S) cluster proteins, and (6) synthesis and storage of preformed pools of S-nitrosothiols (Dringen et al., 2000; Ghezzi, 2005; Franco et al., 2007; Seth and Stamler, 2011; Ghezzi and Chan, 2017; Seckler et al., 2017; Seckler et al., 2020; Seckler et al., 2022). Depleted levels of GSH trigger ROS generation implicated in cell death causing neurological diseases like Alzheimer’s disease, Parkinson’s disease and multiple sclerosis (Lovell et al., 1995; Pearce et al., 1997; Choi et al., 2011; Saharan and Mandal, 2014). A key finding of the present study is that D-CYSee normalized the levels of GSH and GSH/GSSG ratio in SH-SY5Y cells. Whether D-CYSee enhances GSH levels by directly interfering with morphine/opioid-receptor-initiated changes in the activity of enzymes regulating intracellular levels of GSH (e.g., glutathione peroxidase and glutathione reductase) remains to be determined. Although we have established that D-CYSee and related L,D-thiolesters do not directly antagonize opioid-receptors in rats (Gaston et al., 2021; Jenkins et al., 2021; Getsy et al., 2022a; Getsy et al., 2022b; Getsy et al., 2022c; Getsy et al., 2022d; Lewis et al., 2022), it is possible that the application of D-CYSee under the present experimental conditions (overnight incubation) causes a downregulation of plasma membrane opioid receptors in the SH-SY5Y cells per se rather than overcoming opioid-receptor signaling events.

The present study also found that overnight incubation with morphine caused substantial damage to the SH-SY5Y cells as evidenced by the deleterious changes in mitochondrial membrane potential. The mechanisms by which morphine causes injury to mitochondria are multi-factorial and involve, oxidative stress (e.g., increased levels of reactive oxygen species); lipid peroxidation; upregulation of activity of caspase-3 and caspase-9, Drp1 and Mfn2; generation of neuroinflammatory cytokines (e.g., IL-1β, TNF-α, IL-6); raising intracellular Ca2+ to neurotoxic levels (Feng et al., 2013; MacVicar et al., 2015; Kasala et al., 2020; Osmanlıoğlu et al., 2020); and generation of the powerful oxidant/nitrating agent, peroxynitrite (Muscoli et al., 2007). The morphine-induced damage to SH-SY5Y cells may represent early stages of cell death, since morphine induces Beclin 1- and ATG5-dependent autophagy in these cells (Zhao et al., 2010). An exciting finding of the present study was that D-CYSee prevented morphine-induced damage to mitochondria in human SH-SY5Y cells. It is likely that the antioxidant ability of D-CYSee (Getsy et al., 2022e; Getsy et al., 2022f) is involved in this effect since other antioxidants, including curcumin (Motaghinejad et al., 2015), recombinant human growth hormone (Nylander et al., 2016), and the mitochondrial-targeted antioxidant, melatonin (Feng et al., 2013), protect cells from morphine-induced damage. It should be noted that the kappa opioid receptor agonist Salvinorin A reduced the levels of reactive oxygen species, thereby protecting membrane potential and morphology of mitochondria by upregulating the phosphorylation levels of AMPK, and increasing Mfn2 expression (Dong et al., 2019). Moreover, Luo et al. (2013) reported that morphine induced cell damage via the mitochondria-mediated apoptosis pathway by processes involving the activation of caspases-3 and caspases-9, were attenuated by pre-treatment with geranylgeranylacetone, a pharmacological inducer of Trx-1 and Hsp70. All of the above findings are consistent with evidence that the opioid receptor agonist, Tramadol, causes (a) oxidative damage to proteins in mitochondria of SH-SY5Y cells (Faria et al., 2016), and (b) oxidative damage (ROS overproduction) in mitochondria, and via deleterious changes in activity of Complex II (succinate dehydrogenase), in addition to membrane permeability, transition pore disorder, collapse of mitochondrial membrane potential and mitochondria swelling (Mohammadnejad et al., 2021). Furthermore, Samadi et al. (2021) found that caffeine, a nonselective antagonist of adenosine receptors, markedly diminished the ability of Tramadol to increase oxidative stress biomarkers, such as reactive oxygen species, protein carbonyl content, and lipid peroxidation, and to decrease GSH content in brain mitochondria. We found that D-CYSee prevented morphine-induced decreases in global DNA methylation in human SH-SY5Y cells perhaps by enhancing S-adenosylmethionine (SAM)-dependent changes in DNA methyltransferase (DNMT)- and histone methyltransferase (HMT)-dependent processes that drive the methylation status of DNA and histones (Figure 1). Our study also confirms the findings of Trivedi et al. (2014) that morphine decreased 5-mC levels in the LINE-1 gene and increased LINE-1 RNA in SH-SY5Y cells. The LINE-1 gene is a retrotransposon. These genes are relics of viral like sequences that infect the genome and become stably inserted and inherited (McClung et al., 2005). Regulatory sequences surrounding retrotransposons are typically hyper-methylated and so these genes, while they have been evolutionarily maintained in the genome, are silenced. The significance of opioid-induced changes in expression of these genes, and their potential contribution to opioid-induced changes in physiological status, is not clear at present, but it is evident that D-CYSee prevents these morphine-induced changes from happening. As such, it is evident that D-CYSee can maintain redox homeostasis and protect mitochondria from opioid-induced toxicity by mechanisms that may involve the generation of GSH from GSSG (Figure 3). That presence of D-cysteine, and the parallel presence of the enzyme, serine racemase, which interconverts D-cysteine and L-cysteine, as well as D- and L-serine (hence the name serine racemase), implies that another possible mechanistic pathway is D-CYSee - > D-cysteine - > L-cysteine (Semenza et al., 2021).

Betaine is synthesized in mitochondria from choline via choline dehydrogenase (Wang et al., 2006; Ohnishi et al., 2019; Arumugam et al., 2021) and ingested in the diet (He et al., 2012). Betaine is actively transported into cells by organic osmolyte transporter betaine/γ-aminobutyric acid (GABA) transporter BGT1 (SLC6A12) (Lehre et al., 2011; Munoz et al., 2012; Zhou and Danbolt, 2013) that is a member of the Na+- and Cl-dependent neurotransmitter transporter gene family (solute carrier family 6, neurotransmitter, sodium symporter transporter family) with a homology to GABA transporters GAT1 (SLC6A1), GAT2 (SLC6A13) and GAT3 (SLC6A11) (Gerile et al., 2012; Lie et al., 2020; Bhatt et al., 2023). BGT1 activity and expression is regulated by AMP-activated kinase (Munoz et al., 2012), and plays a role in controlling brain excitability (Kempson et al., 2014). Betaine has several biological activities, including (a) anti-oxidative and anti-inflammatory activity (Zhao et al., 2010); (b) provision of the methyl donor, S-adenosylmethionine (Lever and Slow, 2010); (c) key regulator of cellular osmotic status (Chen and Murata, 2008; Knight et al., 2017); and (d) mitigation of the pathologies associated with elevated homocysteine levels (Kumar et al., 2016) (see Supplementary Figure S1 from Ohnishi et al., 2019). The actions of betaine involve the accelerated turnover of the methionine-homocysteine cycle (i.e., one-carbon metabolism/folate cycle), where betaine is a substrate in the betaine-homocysteine S-methyltransferase (BHMT) reaction, which converts homocysteine to the essential reducing compound, methionine (Ueland et al., 2005; Ueland, 2011). Deficits in brain betaine levels may contribute to cellular osmotic perturbation (Knight et al., 2017; Chen and Murata, 2008; Kempson and Montrose, 2004), which is reported to inhibit methionine uptake, inhibit protein synthesis, and affect mRNA translation, by dysregulation of phosphorylation and mTOR signaling cascades (Uesono and Toh, 2002; Patel et al., 2002). Betaine readily penetrates the blood-brain barrier and is well tolerated with few adverse effects (Aramburu et al., 2014). Our pivotal findings in SH-SY5Y cells were that betaine prevented morphine-induced decreases in GSH concentrations (although somewhat less effectively than D-CYSee), restored mitochondrial membrane potential during morphine treatment, prevented morphine-induced decreases in global DNA methylation, and increased expression of LINE-1 RNA. These key effects of betaine are possibly driven by betaine homocysteine methyl-transferase (BHMT)- and methionine adenosyltransferase (MAT)-driven production of SAM-dependent methylation of DNA and histones (Figure 1) (García-Giménez et al., 2017; Wang et al., 1997). As such, it is evident that betaine, like D-CYSee, is able to maintain redox homeostasis and protect mitochondria from opioid-induced toxicity via potential mechanisms that include the generation of methionine from homocysteine (Figure 3).

The present study also demonstrates that the bolus injection of NLX elicited a pronounced withdrawal syndrome in rats that received the escalating morphine injection dose regime plus co-injections of vehicle. The behavioral phenomena consistant with the rats having become dependent on morphine consisted of jumping, wet dog-like shakes, rearing, fore-paw licking (FPL), circling, full body writhing, and sneezing. These, and the recorded falls in body temperature and body weight, are common features of the NLX-induced withdrawal syndrome in morphine-dependent rats (Laska and Fennessy, 1976; Hutchinson et al., 2007; Morgan and Christie, 2011; Nielsen and Kreek, 2012). The withdrawal responses elicited by the injection of NLX in rats that had received co-injections of morphine plus vehicle were qualitatively and quantitatively similar in the rats that had received co-injections of morphine plus D-cysteine. D-cysteine is a naturally occurring amino acid (Kiriyama and Nochi, 2016; Seckler and Lewis, 2020) that can readily be detected in mouse brain (Semenza et al., 2021), although it cannot be readily detected in the brains of other species (Mangas et al., 2007; Seckler and Lewis, 2020). Nonetheless, there is a variety of uptake processes for exogenously administered D-cysteine (Glazenburg et al., 1984; Pisoni et al., 1990; Huang et al., 1998; Simmons-Willis et al., 2002; Erdogan et al., 2021), which has a multiplicity of neurological actions (Seckler and Lewis, 2020). In addition to expected redox effects (Hobbs et al., 1998; Homma et al., 2022), D-cysteine generates intracellular hydrogen sulfide via the D-amino acid oxidase/3-mercaptopyruvate sulfurtransferase pathway (Kimura, 2013; Souza et al., 2017). Accordingly, the lack of effect of the dose of D-cysteine used in this study (250 μmol/kg, = 30.3 mg/kg per each injection) may be because it does not enter brain cells involved in establishing physical dependence to morphine in sufficient quantities to exert meaningful cell-signaling events that can countermand the processes underlying the development of dependence. A major finding of the present study was that the injection of NLX elicited a relatively minor withdrawal syndrome in rats that had received co-injections of morphine and D-CYSee. This finding that the D-thiol ester prevents the development of physical dependence to morphine, is consistent with our novel evidence described above that D-CYSee prevents redox and epigenetic signatures of opioid dependence in human SH-SH5Y neuroblastoma cells treated overnight with morphine and D-CYSee. These findings are supported strongly by another recent finding that D-CYSee prevents fentanyl-induced reward seeking in male and female rats (Knauss et al., 2023).

Chronic opioid administration causes impairment of mitochondrial function (e.g., Bcl-2, Bcl-xL, Bad, and Bax apoptotic pathways) within the brain (Tapia-Arizmendi et al., 1987; García-Estrada et al., 1988; Tramullas et al., 2007; Bekheet et al., 2010) by mechanisms involving the production of reactive oxygen-nitrogen species, such as peroxynitrite (Muscoli et al., 2007; Doyle et al., 2009), which directly contributes to impairment of spatial learning and memory (Tramullas et al., 2008). In addition, Luo et al. (2022) reported that heroin addiction in rats markedly diminishes expression of mitochondrial enzymes, such as cytochrome c oxidase IV and ATP synthase subunit beta. Moreover, Gowen et al. (2023) recently reported that neonatal opioid exposure causes neuroinflammation, and adversely affects the synaptic proteome, mitochondrial function, and behavior in juvenile rats. With respect to the therapeutic efficacy of D-CYSee, we do not have full understanding of the mechanisms by which this D-thiol ester ameliorates the development of physical dependence to morphine in vivo. On the basis of our findings that D-CYSee reverses the effects of morphine on GSH/GSSG ratio in SH-SY5Y cells, it is likely that the antioxidant/reducing properties of D-CYSee allows direct modulation of intracellular redox status (e.g., reduction of L-cystine to L-cysteine and conversion of Fe3+ to Fe2+ in heme proteins), and activity of membrane proteins, such as Kv1.2 K+-channels (Baronas et al., 2017) and functional intracellular proteins (Bogeski et al., 2011; Bogeski and Niemeyer, 2014; O-Uchi et al., 2014; Gamper and Ooi, 2015; Gao et al., 2017; García et al., 2018). Indeed, antioxidants, such as L-NAC, can diminish the development of tolerance and physical dependence to morphine (Abdel-Zaher et al., 2013a; Abdel-Zaher et al., 2013b; Yun et al., 2015; Yun et al., 2017; Yayeh et al., 2016), whereas co-administration of the antioxidants ascorbic acid, uric acid, glutathione, quercetin, and resveratrol, diminish development of oxidative stress and NLX-precipitated withdrawal syndrome in heroin-treated mice (Pan et al., 2005; Xu et al., 2006). Other mechanisms may involve (1) formation of thiol adducts, such as D-glucose:D-cysteine (Wróbel et al., 1997; Szwergold, 2006; Li et al., 2015) and mixed disulfides Wilcken and Gupta, 1979; Lash and Jones, 1985; Turell L et al., 2013) in blood, (2) conversion of D-CYSee to D-cysteine by membrane associated esterases (Butterworth et al., 1993; Nishida et al., 1996), which enter into intracellular signaling pathways, such as those generating hydrogen sulfide, by sequential actions of D-aminoacid oxidase and 3-mercaptopyruvate sulfurtransferase (Kimura, 2014; Kimura, 2014; Kimura, 2017; Beltowski, 2019), and (3) nitric oxide synthase-dependent generation of S-nitroso-D-cysteine ethyl ester and S-nitroso-D-cysteine that may behave like the endogenous S-nitrosothiol, S-nitroso-L-cysteine (Myers et al., 1990; Bates et al., 1991; Seckler et al., 2017; Seckler et al., 2020), which regulates intracellular signaling pathways (Lipton et al., 1993; Stamler, 1995; Foster et al., 2009; Seth and Stamler, 2011; Gaston et al., 2020), including those controlling cardiovascular and ventilatory functions (Davisson et al., 1996; Davisson et al., 1997; Ohta et al., 1997; Lipton et al., 2001; Gaston et al., 2006; Lewis et al., 2006; Gaston et al., 2020) and those that reverse OIRD (Getsy et al., 2022a; Getsy et al., 2022b).

These and other mechanisms may interact with brain signaling pathways involved in the acquisition of physical dependence to opioids and expression of NLX-precipitated withdrawal, including pathways involving N-methyl D-aspartate (NMDA) glutamatergic receptors (Buccafusco et al., 1995; Herman et al., 1995; Rasmussen, 1995; Noda and Nabeshima, 2004; Glass, 2011; Fluyau et al., 2020), muscarinic receptors (Marshall and Buccafusco, 1985; Holland et al., 1993), corticotropin releasing factor (CRF) receptor CRF1 (García-Carmona et al., 2015), tachykinin receptors (Michaud and Couture, 2003), voltage-gated Ca2+-channels (Tokuyama et al., 1995; Dogrul et al., 2002; Esmaeili-Mahani et al., 2008; Alboghobeish et al., 2019), adenylyl cyclase super-activation and phosphorylation of opioid receptor (Avidor-Reiss et al., 1996; Avidor-Reiss et al., 1997; Wang et al., 1999; Eckhardt et al., 2000), oxidative stress (Mori et al., 2007; Abdel-Zaher et al., 2013a; Abdel-Zaher et al., 2013b; Mansouri et al., 2020; Ward et al., 2020; Houshmand et al., 2021), and the nitric oxide-cGMP signaling pathway (Adams et al., 1993; Cappendijk et al., 1993; Majeed et al., 1994; Leza et al., 1995; Leza et al., 1996; London et al., 1995; Vaupel et al., 1995a; Vaupel et al., 1995b; Dambisya and Lee, 1996; Bhatt and Kumar, 2015; Tsakova et al., 2015; Sackner et al., 2019; Gledhill and Babey, 2021). Since D-CYSee markedly attenuated all NLX-precipitated behavioral (except for sneezes) and physical (hypothermia and body weight loss) phenomena, it is possible that D-CYSee modulates fundamental intracellular processes that are critical to the development of physical dependence to morphine in male Sprague Dawley rats. The above discussion is directly relevant to potential mechanisms by which betaine diminished the development of dependence to morphine. An outstanding difference between the effects of betaine and D-CYSee was that unlike D-CYSee, betaine also diminished the occurrence of NLX-precipitated sneezing. Sneezing is a common feature of opioid withdrawal in humans (Ostrea et al., 1975; Specker et al., 1998; Gaalema et al., 2012; Lofwall et al., 2013) and experimental animals (Hendrie, 1985; Liu et al., 2007; Singh et al., 2015). There is considerable information about the neural mechanisms driving sneezing (Batsel and Lines, 1975; Undem et al., 2000; Li et al., 2021; Ramirez et al., 2022), and it is now evident that the cellular events initiated by betaine can be added to these potential mechanisms.

Study limitations

There are several limitations that need to be described. With regards to the studies in the human SH-SH5Y neuroblastoma cells, it is vital to perform studies with longer-term application of morphine, and establish fuller dose-response curves to D-CYSee and betaine. Despite the strength of findings in SH-SH5Y cells, it is imperative to determine how D-CYSee and betaine affect chronic morphine-induced changes in redox (e.g., GSH, GSSG) and epigenetic signatures of physical dependence in brain regions involved in development of physical dependence to opioids, such as medial prefrontal cortex (MPFC), striatum and hippocampus (Deslandes et al., 2002; Gardner, 2011; Koob and Volkow, 2016; Volkow et al., 2019; Koob, 2020; Sakloth et al., 2020). In addition, future studies must establish whether D-CYSee and betaine can overcome physical dependence to fentanyl, since this synthetic opioid has an ever-increasing role in the current opioid crisis (Arendt, 2021; Deo et al., 2021). Another important limitation of our studies is the lack of data about the efficacy of D-CYSee and betaine in preventing the adverse biochemical actions of morphine in female cells, and reversing physical dependence in female rats. This is essential since (a) there are numerous sex-specific differences in opioid receptor signaling (Bryant et al., 2006; Hosseini et al., 2011), (b) opioids have often different responses (e.g., ventilation, analgesia) in females compared to males (Dahan et al., 1998; Sarton et al., 1998; Bodnar and Kest, 2010), (c) there are major sex-dependent differences in development of opioid tolerance/hyperalgesia, and expression of withdrawal responses (Bodnar and Kest, 2010) and (d) there are several major sex differences in the efficacy of treatments for OUD (Huhn et al., 2019; Davis et al., 2021; Knouse and Briand, 2021).

Conclusion

This study provides evidence that application of D-CYSee or betaine prevents the expression of the epigenetic signatures associated with morphine physical dependence/addiction in human SH-SH5Y neuroblastoma cells, and lessens the development of physical dependence to morphine. Our previous studies have demonstrated that the sulfur atom of D-CYSee is vital to the activity of the D-thiol ester (Getsy et al., 2022e; Getsy et al., 2022f), and defining thiol/S-nitrosothiol-dependent signaling pathways (Belcastro et al., 2017; Stomberski et al., 2019) will add greatly to our understanding of how opioids induce dependence, and the mechanisms by which D-thiol esters and D-cysteine (Bonifácio et al., 2021) exert their effects. Trivedi et al. (2014a, 2014b) provided compelling evidence that morphine may cause dependence/addiction by blocking the entry of L-cysteine into neurons by inhibition of the EAA3/EAAC1 transporter, thereby reducing L-cysteine-dependent cell signaling pathways (Yamaguchi and Hosokawa, 1987; Rossi et al., 2009; Stipanuk et al., 2009; Stipanuk et al., 2011). The findings that betaine and D-CYSee markedly reduced the majority of NLX-precipitated withdrawal phenomena suggests that the loss of L-cysteine entry into cells plays a key role in establishing physical dependence to morphine. Additionally, our findings show that betaine and D-CYSee somehow overcome the loss of endogenous L-cysteine in intracellular signaling processes that allow for the development of morphine dependence and addiction. The present findings add to our increasing knowledge about the efficacy of L,D-thiolesters, Tempol, and S-nitroso-L-cysteine in overcoming the adverse action of opioids (Baby et al., 2021a; Baby et al., 2021b; Gaston et al., 2021Getsy et al., 2022a; Getsy et al., 2022b; Getsy et al., 2022c; Getsy et al., 2022d; Getsy et al., 2022e; Getsy et al., 2022f; Lewis et al., 2022).

Statements

Data availability statement

The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.

Ethics statement

The animal study was approved by the Animal Care and Use Committee of Kent State University and Case Western Reserve University. The study was conducted in accordance with the local legislation and institutional requirements.

Author contributions

JM: Conceptualization, Data curation, Investigation, Project administration, Supervision, Validation, Writing–original draft, Writing–review and editing, Methodology. NS: Investigation, Writing–original draft, Writing–review and editing. PG: Investigation, Writing–original draft, Writing–review and editing, Conceptualization, Data curation, Formal Analysis. KK: Investigation, Writing–original draft, Writing–review and editing. ZK: Data curation, Investigation, Writing–original draft, Writing–review and editing. DM: Data curation, Investigation, Writing–original draft, Writing–review and editing. JB: Conceptualization, Data curation, Formal Analysis, Project administration, Writing–original draft, Writing–review and editing. DD: Conceptualization, Writing–original draft, Writing–review and editing. SL: Conceptualization, Data curation, Formal Analysis, Funding acquisition, Investigation, Project administration, Resources, Supervision, Validation, Visualization, Writing–original draft, Writing–review and editing.

Funding

The author(s) declare that no financial support was received for the research, authorship, and/or publication of this article.

Conflict of interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision.

Publisher’s note

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.

References

  • 1

    Abdel-ZaherA. O.MostafaM. G.FarghalyH. S.HamdyM. M.Abdel-HadyR. H. (2013b). Role of oxidative stress and inducible nitric oxide synthase in morphine-induced tolerance and dependence in mice. Effect of alpha-lipoic acid. Behav. Brain Res.247, 1726. 10.1016/j.bbr.2013.02.034

  • 2

    Abdel-ZaherA. O.MostafaM. G.FarghlyH. M.HamdyM. M.OmranG. A.Al-ShaibaniN. K. (2013a). Inhibition of brain oxidative stress and inducible nitric oxide synthase expression by thymoquinone attenuates the development of morphine tolerance and dependence in mice. Eur. J. Pharmacol.702, 6270. 10.1016/j.ejphar.2013.01.036

  • 3

    AdamsM. L.KalickiJ. M.MeyerE. R.CiceroT. J. (1993). Inhibition of the morphine withdrawal syndrome by a nitric oxide synthase inhibitor, NG-nitro-L-arginine methyl ester. Life Sci.52, PL245PL249. 10.1016/0024-3205(93)90472-f

  • 4

    AguirreP.ValdésP.Aracena-ParksP.TapiaV.NúñezM. T. (2007). Upregulation of gamma-glutamate-cysteine ligase as part of the long-term adaptation process to iron accumulation in neuronal SH-SY5Y cells. Am. J. Physiol. Cell Physiol.292, C2197C2203. 10.1152/ajpcell.00620.2006

  • 5

    AlboghobeishS.NaghizadehB.KheirollahA.GhorbanzadehB.MansouriM. T. (2019). Fluoxetine increases analgesic effects of morphine, prevents development of morphine tolerance and dependence through the modulation of L-type calcium channels expression in mice. Behav. Brain Res.361, 8694. 10.1016/j.bbr.2018.12.020

  • 6

    AramburuJ.OrtellsM. C.TejedorS.BuxadéM.López-RodríguezC. (2014). Transcriptional regulation of the stress response by mTOR. Sci. Signal7, re2. 10.1126/scisignal.2005326

  • 7

    ArendtF. (2021). The opioid-overdose crisis and fentanyl: the role of online information seeking via internet search engines. Health Commun.36, 11481154. 10.1080/10410236.2020.1748820

  • 8

    ArumugamM. K.PaalM. C.DonohueT. M.JrGanesanM.OsnaN. A.KharbandaK. K. (2021). Beneficial effects of betaine: a comprehensive review. Biol. (Basel)10, 456. 10.3390/biology10060456

  • 9

    Avidor-ReissT.NevoI.LevyR.PfeufferT.VogelZ. (1996). Chronic opioid treatment induces adenylyl cyclase V superactivation. Involvement of Gbetagamma. J. Biol. Chem.271, 2130921315. 10.1074/jbc.271.35.21309

  • 10

    Avidor-ReissT.NevoI.SayaD.BayewitchM.VogelZ. (1997). Opiate-induced adenylyl cyclase superactivation is isozyme-specific. J. Biol. Chem.272, 50405047. 10.1074/jbc.272.8.5040

  • 11

    BabyS.GruberR.DiscalaJ.PuskovicV.JoseN.ChengF.et al (2021b). Systemic administration of Tempol attenuates the cardiorespiratory depressant effects of fentanyl. Front. Pharmacol.12, 690407. 10.3389/fphar.2021.690407

  • 12

    BabyS. M.DiscalaJ. F.GruberR.GetsyP. M.ChengF.DamronD. S.et al (2021a). Tempol reverses the negative effects of morphine on arterial blood-gas chemistry and tissue oxygen saturation in freely-moving rats. Front. Pharmacol.12, 749084. 10.3389/fphar.2021.749084

  • 13

    BaronasV. A.YangR. Y.KurataH. T. (2017). Extracellular redox sensitivity of Kv1.2 potassium channels. Sci. Rep.7, 9142. 10.1038/s41598-017-08718-z

  • 14

    BatesJ. N.HarrisonD. G.MyersP. R.MinorR. L. (1991). EDRF: nitrosylated compound or authentic nitric oxide. Basic Res. Cardiol.86 (Suppl. 2), 1726. 10.1007/978-3-642-72461-9_3

  • 15

    BatselH. L.LinesA. J. (1975). Neural mechanisms of sneeze. Am. J. Physiol.229, 770776. 10.1152/ajplegacy.1975.229.3.770

  • 16

    BekheetS. H.SakerS. A.Abdel-KaderA. M.YounisA. E. (2010). Histopathological and biochemical changes of morphine sulphate administration on the cerebellum of albino rats. Tissue Cell42, 165175. 10.1016/j.tice.2010.03.005

  • 17

    BelcastroE.GaucherC.CortiA.LeroyP.LartaudI.PompellaA. (2017). Regulation of protein function by S-nitrosation and S-glutathionylation: processes and targets in cardiovascular pathophysiology. Biol. Chem.398, 12671293. 10.1515/hsz-2017-0150

  • 18

    BeltowskiJ. (2019). Synthesis, metabolism, and signaling mechanisms of hydrogen sulfide: an overview. Methods Mol. Biol.2007, 18. 10.1007/978-1-4939-9528-8_1

  • 19

    BhattK.KumarA. (2015). Mechanism of morphine addiction by inhibiting the soluble Guanylate Cyclase-Nitric Oxide (sGC-NO) pathway. Math. Biosci.266, 8592. 10.1016/j.mbs.2015.06.004

  • 20

    BhattM.Gauthier-ManuelL.LazzarinE.ZerlottiR.ZieglerC.BazzoneA.et al (2023). A comparative review on the well-studied GAT1 and the understudied BGT-1 in the brain. Front. Physiol.14, 1145973. 10.3389/fphys.2023.1145973

  • 21

    BodnarR. J.KestB. (2010). Sex differences in opioid analgesia, hyperalgesia, tolerance and withdrawal: central mechanisms of action and roles of gonadal hormones. Horm. Behav.58, 7281. 10.1016/j.yhbeh.2009.09.012

  • 22

    BogeskiI.KapplR.KummerowC.GulaboskiR.HothM.NiemeyerB. A. (2011). Redox regulation of calcium ion channels: chemical and physiological aspects. Cell Calcium50, 407423. 10.1016/j.ceca.2011.07.006

  • 23

    BogeskiI.NiemeyerB. A. (2014). Redox regulation of ion channels. Antioxid. Redox Signal21, 859862. 10.1089/ars.2014.6019

  • 24

    BonifácioV. D. B.PereiraS. A.SerpaJ.VicenteJ. B. (2021). Cysteine metabolic circuitries: druggable targets in cancer. Br. J. Cancer124, 862879. 10.1038/s41416-020-01156-1

  • 25

    BottiglieriT. (2013). Folate, vitamin B12, and S-adenosylmethionine. Psychiatr. Clin. North Am.36, 113. 10.1016/j.psc.2012.12.001

  • 26

    BrownN.AlkhayerK.ClementsR.SinghalN.GregoryR.AzzamS.et al (2016). Neuronal hemoglobin expression and its relevance to multiple sclerosis neuropathology. J. Mol. Neurosci.59, 117. 10.1007/s12031-015-0711-6

  • 27

    BrowneC. J.GodinoA.SaleryM.NestlerE. J. (2020). Epigenetic mechanisms of opioid addiction. Biol. Psychiatry87, 2233. 10.1016/j.biopsych.2019.06.027

  • 28

    BryantC. D.EitanS.SinchakK.FanselowM. S.EvansC. J. (2006). NMDA receptor antagonism disrupts the development of morphine analgesic tolerance in male, but not female C57BL/6J mice. Am. J. Physiol. Regul. Integr. Comp. Physiol.291, R315R326. 10.1152/ajpregu.00831.2005

  • 29

    BuccafuscoJ. J.TerryA. V.ShusterL. (1995). Spinal NMDA receptor - nitric oxide mediation of the expression of morphine withdrawal symptoms in the rat. Brain Res.679, 189199. 10.1016/0006-8993(95)00203-3

  • 30

    ButterworthM.UpshallD. G.CohenG. M. (1993). A novel role for carboxylesterase in the elevation of cellular cysteine by esters of cysteine. Biochem. Pharmacol.46, 11311137. 10.1016/0006-2952(93)90460-e

  • 31

    CantoniG. L. (1975). Biological methylation: selected aspects. Annu. Rev. Biochem.44, 435451. 10.1146/annurev.bi.44.070175.002251

  • 32

    CappendijkS. L.de VriesR.DzoljicM. R. (1993). Inhibitory effect of nitric oxide (NO) synthase inhibitors on naloxone-precipitated withdrawal syndrome in morphine-dependent mice. Neurosci. Lett.162, 97100. 10.1016/0304-3940(93)90569-7

  • 33

    ChenT. H.MurataN. (2008). Glycinebetaine: an effective protectant against abiotic stress in plants. Trends Plant Sci.13, 499505. 10.1016/j.tplants.2008.06.007

  • 34

    ChenX.ZhangB.LiuT.FengM.ZhangY.ZhangC.et al (2019). Liproxstatin-1 attenuates morphine tolerance through inhibiting spinal ferroptosis-like cell death. ACS Chem. Neurosci.10, 48244833. 10.1021/acschemneuro.9b00539

  • 35

    ChoiI.-Y.LeeS.DenneyD. R.LynchS. G. (2011). Lower levels of glutathione in the brains of secondary progressive multiple sclerosis patients measured by 1H magnetic resonance chemical shift imaging at 3 T. Mult. Scler. J.17, 289296. 10.1177/1352458510384010

  • 36

    ChristieM. J. (2008). Cellular neuroadaptations to chronic opioids: tolerance, withdrawal and addiction. Brit J. Pharmacol.154, 384396. 10.1038/bjp.2008.100

  • 37

    DahanA.SartonE.TeppemaL.OlievierC. (1998). Sex-related differences in the influence of morphine on ventilatory control in humans. Anesthesiology88, 903913. 10.1097/00000542-199804000-00009

  • 38

    DaijoH.KaiS.TanakaT.WakamatsuT.KishimotoS.SuzukiK.et al (2011). Fentanyl activates hypoxia-inducible factor 1 in neuronal SH-SY5Y cells and mice under non-hypoxic conditions in a μ-opioid receptor-dependent manner. Eur. J. Pharmacol.667, 144152. 10.1016/j.ejphar.2011.06.014

  • 39

    DambisyaY. M.LeeT. L. (1996). Role of nitric oxide in the induction and expression of morphine tolerance and dependence in mice. Br. J. Pharmacol.117, 914918. 10.1111/j.1476-5381.1996.tb15280.x

  • 40

    DavisJ. P.EddieD.PrindleJ.DworkinE. R.ChristieN. C.SabaS.et al (2021). Sex differences in factors predicting post-treatment opioid use. Addiction116, 21162126. 10.1111/add.15396

  • 41

    DavissonR. L.TravisM. D.BatesJ. N.JohnsonA. K.LewisS. J. (1997). Stereoselective actions of S-nitrosocysteine in central nervous system of conscious rats. Am. J. Physiol.272, H2361H2368. 10.1152/ajpheart.1997.272.5.H2361

  • 42

    DavissonR. L.TravisM. D.BatesJ. N.LewisS. J. (1996). Hemodynamic effects of L- and D-S-nitrosocysteine in the rat. Stereoselective S-nitrosothiol recognition sites. Circ. Res.79, 256262. 10.1161/01.res.79.2.256

  • 43

    DebI.DasS. (2011). Thyroid hormones protect astrocytes from morphine-induced apoptosis by regulating nitric oxide and pERK 1/2 pathways. Neurochem. Int.58, 861871. 10.1016/j.neuint.2011.01.001

  • 44

    DeoV. S.GilsonT. P.KasparC.SingerM. E. (2021). The fentanyl phase of the opioid epidemic in Cuyahoga County, Ohio, United States. J. Forensic Sci.66, 926933. 10.1111/1556-4029.14665

  • 45

    De Sa NogueiraD.MerienneK.BefortK. (2018). Neuroepigenetics and addictive behaviors: where do we stand?Neurosci. Biobehav Rev.S0149-7634 (18), 5872. 10.1016/j.neubiorev.2018.08.018

  • 46

    DeslandesP. N.PacheD. M.SewellR. D. (2002). Drug dependence: neuropharmacology and management. J. Pharm. Pharmacol.54, 885895. 10.1211/002235702760088992

  • 47

    DiasI. H.MistryJ.FellS.ReisA.SpickettC. M.PolidoriM. C.et al (2014). Oxidized LDL lipids increase β-amyloid production by SH-SY5Y cells through glutathione depletion and lipid raft formation. Free Radic. Biol. Med.75, 4859. 10.1016/j.freeradbiomed.2014.07.012

  • 48

    DogrulA.ZagliU.TulunayF. C. (2002). The role of T-type calcium channels in morphine analgesia, development of antinociceptive tolerance and dependence to morphine, and morphine abstinence syndrome. Life Sci.71, 725734. 10.1016/s0024-3205(02)01736-8

  • 49

    DongH.ZhouW.XinJ.ShiH.YaoX.HeZ.et al (2019). Salvinorin A moderates postischemic brain injury by preserving endothelial mitochondrial function via AMPK/Mfn2 activation. Exp. Neurol.322, 113045. 10.1016/j.expneurol.2019.113045

  • 50

    DoyleT.BryantL.Batinic-HaberleI.LittleJ.CuzzocreaS.MasiniE.et al (2009). Supraspinal inactivation of mitochondrial superoxide dismutase is a source of peroxynitrite in the development of morphine antinociceptive tolerance. Neuroscience164, 702710. 10.1016/j.neuroscience.2009.07.019

  • 51

    DringenR.GuttererJ. M.HirrlingerJ. (2000). Glutathione metabolism in brain metabolic interaction between astrocytes and neurons in the defense against reactive oxygen species. Eur. J. Biochem.267, 49124916. 10.1046/j.1432-1327.2000.01597.x

  • 52

    DwivediD.MeghaK.MishraR.MandalP. K. (2020). Glutathione in brain: overview of its conformations, functions, biochemical characteristics, quantitation and potential therapeutic role in brain disorders. Neurochem. Res.45, 14611480. 10.1007/s11064-020-03030-1

  • 53

    EckhardtK.NevoI.LevyR.MikusG.EichelbaumM.VogelZ. (2000). Morphine-related metabolites differentially activate adenylyl cyclase isozymes after acute and chronic administration. FEBS Lett.470, 309314. 10.1016/s0014-5793(00)01329-6

  • 54

    Eklöw-LåstbomL.MoldéusP.OrreniusS. (1986). On the mechanisms of glutathione depletion in hepatocytes exposed to morphine and ethylmorphine. Toxicology42, 1321. 10.1016/0300-483x(86)90088-0

  • 55

    ErdoganY. C.AltunH. Y.SecilmisM.AtaB. N.SevimliG.CoklukZ.et al (2021). Complexities of the chemogenetic toolkit: differential mDAAO activation by d-amino substrates and subcellular targeting. Free Radic. Biol. Med.177, 132142. 10.1016/j.freeradbiomed.2021.10.023

  • 56

    Esmaeili-MahaniS.FathiY.MotamediF.HosseinpanahF.AhmadianiA. (2008). L-type calcium channel blockade attenuates morphine withdrawal: in vivo interaction between L-type calcium channels and corticosterone. Horm. Behav.53, 351357. 10.1016/j.yhbeh.2007.10.012

  • 57

    FariaJ.BarbosaJ.QueirósO.MoreiraR.CarvalhoF.Dinis-OliveiraR. J. (2016). Comparative study of the neurotoxicological effects of tramadol and tapentadol in SH-SY5Y cells. Toxicology359-360, 110. 10.1016/j.tox.2016.06.010

  • 58

    FengY. M.JiaY. F.SuL. Y.WangD.LvL.XuL.et al (2013). Decreased mitochondrial DNA copy number in the hippocampus and peripheral blood during opiate addiction is mediated by autophagy and can be salvaged by melatonin. Autophagy9, 13951406. 10.4161/auto.25468

  • 59

    FluyauD.RevadigarN.PierreC. G. (2020). Clinical benefits and risks of N-methyl-d-aspartate receptor antagonists to treat severe opioid use disorder: a systematic review. Drug Alcohol Depend.208, 107845. 10.1016/j.drugalcdep.2020.107845

  • 60

    FosterM. W.HessD. T.StamlerJ. S. (2009). Protein S-nitrosylation in health and disease: a current perspective. Trends Mol. Med.15, 391404. 10.1016/j.molmed.2009.06.007

  • 61

    FrancoR.SchoneveldO. J.PappaA.PanayiotidisM. I. (2007). The central role of glutathione in the pathophysiology of human diseases. Arch. Physiol. Biochem.113, 234258. 10.1080/13813450701661198

  • 62

    FroeseD. S.FowlerB.BaumgartnerM. R. (2019). Vitamin B12, folate, and the methionine remethylation cycle-biochemistry, pathways, and regulation. J. Inherit. Metab. Dis.42, 673685. 10.1002/jimd.12009

  • 63

    GaalemaD. E.ScottT. L.HeilS. H.CoyleM. G.KaltenbachK.BadgerG. J.et al (2012). Differences in the profile of neonatal abstinence syndrome signs in methadone-versus buprenorphine-exposed neonates. Addiction107 (Suppl. 1(0 1)), 5362. 10.1111/j.1360-0443.2012.04039.x

  • 64

    GamperN.OoiL. (2015). Redox and nitric oxide-mediated regulation of sensory neuron ion channel function. Antioxid. Redox Signal22, 486504. 10.1089/ars.2014.5884

  • 65

    GaoL.González-RodríguezP.Ortega-SáenzP.López-BarneoJ. (2017). Redox signaling in acute oxygen sensing. Redox Biol.12, 908915. 10.1016/j.redox.2017.04.033

  • 66

    GarcíaI. E.SánchezH. A.MartínezA. D.RetamalM. A. (2018). Redox-mediated regulation of connexin proteins; focus on nitric oxide. Biochim. Biophys. Acta Biomembr.1860, 9195. 10.1016/j.bbamem.2017.10.006

  • 67

    García-CarmonaJ. A.Martínez-LaordenE.MilanésM. V.LaordenM. L. (2015). Sympathetic activity induced by naloxone-precipitated morphine withdrawal is blocked in genetically engineered mice lacking functional CRF1 receptor. Toxicol. Appl. Pharmacol.283, 4249. 10.1016/j.taap.2015.01.002

  • 68

    García-EstradaJ.Tapia-ArizmendiG.Feria-VelascoA.AlemánV. (1988). Ultrastructural alterations in caudate nucleus, cerebral cortex and hippocampus produced by morphine. Gen. Pharmacol.19, 841848. 10.1016/s0306-3623(88)80016-8

  • 69

    García-GiménezJ. L.Romá-MateoC.Pérez-MachadoG.Peiró-ChovaL.PallardóF. V. (2017). Role of glutathione in the regulation of epigenetic mechanisms in disease. Free Rad. Biol. Med.112, 3648. 10.1016/j.freeradbiomed.2017.07.008

  • 70

    GardnerE. L. (2011). Addiction and brain reward and antireward pathways. Adv. Psychosom. Med.30, 2260. 10.1159/000324065

  • 71

    GastonB.BabyS. M.MayW. J.YoungA. P.GrossfieldA.BatesJ. N.et al (2021). D-Cystine di(m)ethyl ester reverses the deleterious effects of morphine on ventilation and arterial blood gas chemistry while promoting antinociception. Sci. Rep.11, 10038. 10.1038/s41598-021-89455-2

  • 72

    GastonB.SingelD.DoctorA.StamlerJ. S. (2006). S-nitrosothiol signaling in respiratory biology. Am. J. Respir. Crit. Care Med.173, 11861193. 10.1164/rccm.200510-1584PP

  • 73

    GastonB.SmithL.BoschJ.SecklerJ.KunzeD.KiselarJ.et al (2020). Voltage-gated potassium channel proteins and stereoselective S-nitroso-l-cysteine signaling. JCI Insight5, e134174. 10.1172/jci.insight.134174

  • 74

    GerileS. C.OhyamaK.MasukoT.KusamaT.MoritaK.SogawaN.et al (2012). Inhibitory action of antidepressants on mouse Betaine/GABA transporter (BGT1) heterologously expressed in cell cultures. Int. J. Mol. Sci.13, 25782589. 10.3390/ijms13032578

  • 75

    GetsyP. M.BabyS. M.GruberR. B.GastonB.LewisT. H. J.GrossfieldA.et al (2022c). S-Nitroso-L-Cysteine stereoselectively blunts the deleterious effects of fentanyl on breathing while augmenting antinociception in freely-moving rats. Front. Pharmacol.13, 892307. 10.3389/fphar.2022.892307

  • 76

    GetsyP. M.BabyS. M.MayW. J.BatesJ. N.EllisC. R.FeaselM. G.et al (2022b). L-cysteine methyl ester overcomes the deleterious effects of morphine on ventilatory parameters and arterial blood-gas chemistry in unanesthetized rats. Front. Pharmacol.13, 968378. 10.3389/fphar.2022.968378

  • 77

    GetsyP. M.BabyS. M.MayW. J.LewisT. H. J.BatesJ. N.HsiehY. H.et al (2022a). L-NAC reverses of the adverse effects of fentanyl infusion on ventilation and blood-gas chemistry. Biomed. Pharmacother.153, 113277. 10.1016/j.biopha.2022.113277

  • 78

    GetsyP. M.BabyS. M.MayW. J.YoungA. P.GastonB.HodgesM. R.et al (2022e). D-cysteine ethyl ester reverses the deleterious effects of morphine on breathing and arterial blood-gas chemistry in freely-moving rats. Front. Pharmacol.13, 883329. 10.3389/fphar.2022.883329

  • 79

    GetsyP. M.CoffeeG. A.LewisS. J. (2023b). Loss of ganglioglomerular nerve input to the carotid body impacts the hypoxic ventilatory response in freely-moving rats. Front. Physiol.14, 1007043. 10.3389/fphys.2023.1007043

  • 80

    GetsyP. M.DavisJ.CoffeeG. A.LewisT. H. J.LewisS. J. (2023a). Hypercapnic signaling influences hypoxic signaling in the control of breathing in C57BL6 mice. J. Appl. Physiol.134, 11881206. 10.1152/japplphysiol.00548.2022

  • 81

    GetsyP. M.YoungA. P.BatesJ. N.BabyS. M.SecklerJ. M.GrossfieldA.et al (2022d). S-nitroso-L-cysteine stereoselectively blunts the adverse effects of morphine on breathing and arterial blood gas chemistry while promoting analgesia. Biomed. Pharmacother.153, 113436. 10.1016/j.biopha.2022.113436

  • 82

    GetsyP. M.YoungA. P.GrossfieldA.SecklerJ. M.WilsonC. G.GastonB.et al (2022f). D-cysteine ethyl ester and D-cystine dimethyl ester reverse the deleterious effects of morphine on arterial blood-gas chemistry and Alveolar-arterial gradient in anesthetized rats. Resp. Physiol. Neurobiol.302, 103912. 10.1016/j.resp.2022.103912

  • 83

    GhezziP. (2005). Regulation of protein function by glutathionylation. Free Radic. Res.39, 573580. 10.1080/10715760500072172

  • 84

    GhezziP.ChanP. (2017). Redox proteomics applied to the thiol secretome. Antioxid. Redox Signal26, 299312. 10.1089/ars.2016.6732

  • 85

    GlassM. J. (2011). Opioid dependence and NMDA receptors. ILAR J.52, 342351. 10.1093/ilar.52.3.342

  • 86

    GlazenburgE. J.Jekel-HalsemaI. M.Baranczyk-KuzmaA.KrijgsheldK. R.MulderG. J. (1984). D-cysteine as a selective precursor for inorganic sulfate in the rat in vivo. Effect of D-cysteine on the sulfation of harmol. Biochem. Pharmacol.33, 625628. 10.1016/0006-2952(84)90318-6

  • 87

    GledhillL. J.BabeyA. M. (2021). Synthesis of the mechanisms of opioid tolerance: do we still say NO?Cell Mol. Neurobiol.41, 927948. 10.1007/s10571-021-01065-8

  • 88

    GoudasL. C.LangladeA.SerrieA.MatsonW.MilburyP.ThurelC.et al (1999). Acute decreases in cerebrospinal fluid glutathione levels after intracerebroventricular morphine for cancer pain. Anesth. Analg.89, 12091215. 10.1097/00000539-199911000-00023

  • 89

    GowenA. M.YiJ.StauchK.MilesL.SrinivasanS.OdegaardK.et al (2023). In utero and post-natal opioid exposure followed by mild traumatic brain injury contributes to cortical neuroinflammation, mitochondrial dysfunction, and behavioral deficits in juvenile rats. Brain Behav. Immun. Health32, 100669. 10.1016/j.bbih.2023.100669

  • 90

    GutP.VerdinE. (2013). The nexus of chromatin regulation and intermediary metabolism. Nature502, 489498. 10.1038/nature12752

  • 91

    GutowiczM.KaźmierczakB.Barańczyk-KuźmaA. (2011). The influence of heroin abuse on glutathione-dependent enzymes in human brain. Drug Alcohol Depend.113, 812. 10.1016/j.drugalcdep.2010.06.020

  • 92

    GuzmánD. C.BrizuelaN. O.AlvarezR. G.GarcíaE. H.MejíaG. B.OlguínH. J. (2009). Cerebrolysin and morphine decrease glutathione and 5-hydroxyindole acetic acid levels in fasted rat brain. Biomed. Pharmacother.63, 517521. 10.1016/j.biopha.2008.09.013

  • 93

    HeS.ZhouZ.LiuY.CaoY.MengK.ShiP.et al (2012). Do dietary betaine and the antibiotic florfenicol influence the intestinal autochthonous bacterial community in hybrid tilapia (Oreochromis niloticus ♀ × O. aureus ♂)?World J. Microbiol. Biotechnol.28, 785791. 10.1007/s11274-011-0871-7

  • 94

    HendrieC. A. (1985). Opiate dependence and withdrawal-a new synthesis?Pharmacol. Biochem. Behav.23, 863870. 10.1016/0091-3057(85)90084-x

  • 95

    HermanB. H.VocciF.BridgeP. (1995). The effects of NMDA receptor antagonists and nitric oxide synthase inhibitors on opioid tolerance and withdrawal. Medication development issues for opiate addiction. Neuropsychopharmacology13, 269293. 10.1016/0893-133X(95)00140-9

  • 96

    HobbsM. J.WilliamsN. E.PatelS. K.UpshallD. G. (1998). Elevation of endogenous nucleophiles in rat lung by cysteine and glutathione esters in vitro. Biochem. Pharmacol.55, 15731584. 10.1016/s0006-2952(97)00674-6

  • 97

    HollandL. N.ShusterL. C.BuccafuscoJ. J. (1993). Role of spinal and supraspinal muscarinic receptors in the expression of morphine withdrawal symptoms in the rat. Neuropharmacology32, 13871395. 10.1016/0028-3908(93)90035-2

  • 98

    HommaT.OsakiT.KobayashiS.SatoH.FujiiJ. (2022). d-Cysteine supplementation partially protects against ferroptosis induced by xCT dysfunction via increasing the availability of glutathione. J. Clin. Biochem. Nutr.71, 4854. 10.3164/jcbn.21-143

  • 99

    HosseiniM.TaiaraniZ.HadjzadehM. A.SalehabadiS.TehranipourM.AlaeiH. A. (2011). Different responses of nitric oxide synthase inhibition on morphine-induced antinociception in male and female rats. Pathophysiology18, 143149. 10.1016/j.pathophys.2010.05.004

  • 100

    HoushmandG.PourasgharM.ShiranM.Arab FirozjaeA.GoudarziM.ManouchehrF.et al (2021). Simvastatin prevents morphine antinociceptive tolerance and withdrawal symptoms through antioxidative effect and nitric oxide pathway in mice. Behav. Brain Res.402, 113104. 10.1016/j.bbr.2020.113104

  • 101

    HuangJ.KhanS.O'BrienP. J. (1998). The glutathione dependence of inorganic sulfate formation from L- or D-cysteine in isolated rat hepatocytes. Chem. Biol. Interact.110, 189202. 10.1016/s0009-2797(98)00015-5

  • 102

    HuhnA. S.BerryM. S.DunnK. E. (2019). Review: sex-based differences in treatment outcomes for persons with opioid use disorder. Am. J. Addict.28, 246261. 10.1111/ajad.12921

  • 103

    HutchinsonM. R.BlandS. T.JohnsonK. W.RiceK. C.MaierS. F.WatkinsL. R. (2007). Opioid-induced glial activation: mechanisms of activation and implications for opioid analgesia, dependence, and reward. ScientificWorldJournal.7, 98111. 10.1100/tsw.2007.230

  • 104

    IkemotoM. J.InoueK.AkidukiS.OsugiT.ImamuraT.IshidaN.et al (2002). Identification of addicsin/GTRAP3-18 as a chronic morphine-augmented gene in amygdala. Neuroreport13, 20792084. 10.1097/00001756-200211150-00018

  • 105

    ItoS.D’AlessioA. C.TaranovaO. V.HongK.SowersL. C.ZhangY. (2010). Role of Tet proteins in 5mC to 5hmC conversion, ES cell self-renewal and inner cell mass specification. Nature466, 11291133. 10.1038/nature09303

  • 106

    JenkinsM. W.KhalidF.BabyS. M.MayW. J.YoungA. P.BatesJ. N.et al (2021). Glutathione ethyl ester reverses the deleterious effects of fentanyl on ventilation and arterial blood-gas chemistry while prolonging fentanyl-induced analgesia. Sci. Rep.11, 6985. 10.1038/s41598-021-86458-x

  • 107

    KasalaS.BriyalS.PrazadP.RanjanA. K.StefanovG.DonovanR.et al (2020). Exposure to morphine and caffeine induces apoptosis and mitochondrial dysfunction in a neonatal rat brain. Front. Pediatr.8, 593. 10.3389/fped.2020.00593

  • 108

    KempsonS. A.MontroseM. H. (2004). Osmotic regulation of renal betaine transport: transcription and beyond. Pflugers Arch.449, 227234. 10.1007/s00424-004-1338-6

  • 109

    KempsonS. A.ZhouY.DanboltN. C. (2014). The betaine/GABA transporter and betaine: roles in brain, kidney, and liver. Front. Physiol.5, 159. 10.3389/fphys.2014.00159

  • 110

    KeszlerA.ZhangY.HoggN. (2010). Reaction between nitric oxide, glutathione, and oxygen in the presence and absence of protein: how are S-nitrosothiols formed?Free Radic. Biol. Med.48, 5564. 10.1016/j.freeradbiomed.2009.10.026

  • 111

    KimuraH. (2013). Physiological role of hydrogen sulfide and polysulfide in the central nervous system. Neurochem. Int.63, 492497. 10.1016/j.neuint.2013.09.003

  • 112

    KimuraH. (2014). The physiological role of hydrogen sulfide and beyond. Nitric Oxide41, 410. 10.1016/j.niox.2014.01.002

  • 113

    KimuraH. (2017). Hydrogen sulfide and polysulfide signaling. Antioxid. Redox Signal.27, 619621. 10.1089/ars.2017.7076

  • 114

    KiriyamaY.NochiH. (2016). D-amino acids in the nervous and endocrine systems. Sci. (Cairo).2016, 6494621. 10.1155/2016/6494621

  • 115

    KnaussZ. T.HearnC. J.HendryxN. C.AboalrobF. S.Mueller-FigueroaY.DamronD. S.et al (2023). Fentanyl-induced reward seeking is sex and dose dependent and is prevented by D-cysteine ethylester. Front. Pharmacol.14, 1241578. 10.3389/fphar.2023.1241578

  • 116

    KnightL. S.PiibeQ.LambieI.PerkinsC.YanceyP. H. (2017). Betaine in the brain: characterization of betaine uptake, its influence on other osmolytes and its potential role in neuroprotection from osmotic stress. Neurochem. Res.42, 34903503. 10.1007/s11064-017-2397-3

  • 117

    KnollemaS.HomH. W.SchirmerH.KorfJ.Ter HorstG. J. (1996). Immunolocalization of glutathione reductase in the murine brain. J. Comp. Neurol.373, 157172. 10.1002/(SICI)1096-9861(19960916)373:2<157::AID-CNE1>3.0.CO;2-2

  • 118

    KnouseM. C.BriandL. A. (2021). Behavioral sex differences in cocaine and opioid use disorders: the role of gonadal hormones. Neurosci. Biobehav Rev.128, 358366. 10.1016/j.neubiorev.2021.06.038

  • 119

    KoobG. F. (2020). Neurobiology of opioid addiction: opponent process, hyperkatifeia, and negative reinforcement. Biol. Psychiatry87, 4453. 10.1016/j.biopsych.2019.05.023

  • 120

    KoobG. F.VolkowN. D. (2016). Neurobiology of addiction: a neurocircuitry analysis. Lancet Psychiatry3, 760773. 10.1016/S2215-0366(16)00104-8

  • 121

    KumarT.SharmaG. S.SinghL. R. (2016). Homocystinuria: therapeutic approach. Clin. Chim. Acta458, 5562. 10.1016/j.cca.2016.04.002

  • 122

    LashL. H.JonesD. P. (1985). Distribution of oxidized and reduced forms of glutathione and cysteine in rat plasma. Arch. Biochem. Biophys.240, 583592. 10.1016/0003-9861(85)90065-7

  • 123

    LaskaJ. F.FennessyM. R. (1976). Physical dependence in the rat induced by slow release morphine: dose-response, time course and brain biogenic amines. Clin. Exp. Pharmacol. Physiol.3, 587598. 10.1111/j.1440-1681.1976.tb00640.x

  • 124

    LehreA. C.RowleyN. M.ZhouY.HolmsethS.GuoC.HolenT.et al (2011). Deletion of the betaine-GABA transporter (BGT1; slc6a12) gene does not affect seizure thresholds of adult mice. Epilepsy Res.95, 7081. 10.1016/j.eplepsyres.2011.02.014

  • 125

    LeverM.SlowS. (2010). The clinical significance of betaine, an osmolyte with a key role in methyl group metabolism. Clin. Biochem.43, 732744. 10.1016/j.clinbiochem.2010.03.009

  • 126

    LewisS. J.OwenJ. R.BatesJ. N. (2006). S-nitrosocysteine elicits hemodynamic responses similar to those of the Bezold-Jarisch reflex via activation of stereoselective recognition sites. Eur. J. Pharmacol.531, 254258. 10.1016/j.ejphar.2005.11.027

  • 127

    LewisT. H. J.MayW. J.YoungA. P.BatesJ. N.BabyS. M.GetsyP. M.et al (2022). The ventilatory depressant actions but not the antinociceptive effects of morphine are blunted in rats receiving intravenous infusion of L-cysteine ethyl ester. Biomed. Pharmacother.156, 113939. 10.1016/j.biopha.2022.113939

  • 128

    LezaJ. C.LizasoainI.CuéllarB.MoroM. A.LorenzoP. (1996). Correlation between brain nitric oxide synthase activity and opiate withdrawal. Naunyn Schmiedeb. Arch. Pharmacol.353, 349354. 10.1007/BF00168639

  • 129

    LezaJ. C.LizasoainI.San-Martín-ClarkO.LorenzoP. (1995). Morphine-induced changes in cerebral and cerebellar nitric oxide synthase activity. Eur. J. Pharmacol.285, 9598. 10.1016/0014-2999(95)00474-y

  • 130

    LiF.JiangH.ShenX.YangW.GuoC.WangZ.et al (2021). Sneezing reflex is mediated by a peptidergic pathway from nose to brainstem. Cell184, 37623773.e10. 10.1016/j.cell.2021.05.017

  • 131

    LiY.SuL.LiF.WangC.YuanD.ChenJ.et al (2015). Acute and sub-chronic toxicity of glucose-cysteine Maillard reaction products in Sprague-Dawley rats. Food Chem. Toxicol.80, 271276. 10.1016/j.fct.2015.03.021

  • 132

    LieM. E. K.KickingerS.Skovgaard-PetersenJ.EckerG. F.ClausenR. P.SchousboeA.et al (2020). Pharmacological characterization of a betaine/GABA transporter 1 (BGT1) inhibitor displaying an unusual biphasic inhibition profile and anti-seizure effects. Neurochem. Res.45, 15511565. 10.1007/s11064-020-03017-y

  • 133

    LimG.WangS.MaoJ. (2012). cAMP and protein kinase A contribute to the downregulation of spinal glutamate transporters after chronic morphine. Neurosci. Lett.376, 913. 10.1016/j.neulet.2004.11.016

  • 134

    LinC. I.OrlovI.RuggieroA. M.Dykes-HobergM.LeeA.JacksonM.et al (2001). Modulation of the neuronal glutamate transporter EAAC1 by the interacting protein GTRAP3-18. Nature410, 8488. 10.1038/35065084

  • 135

    LiptonA. J.JohnsonM. A.MacdonaldT.LiebermanM. W.GozalD.GastonB. (2001). S-nitrosothiols signal the ventilatory response to hypoxia. Nature413, 171174. 10.1038/35093117

  • 136

    LiptonS. A.ChoiY. B.PanZ. H.LeiS. Z.ChenH. S.SucherN. J.et al (1993). A redox-based mechanism for the neuroprotective and neurodestructive effects of nitric oxide and related nitroso-compounds. Nature364, 626632. 10.1038/364626a0

  • 137

    LiuL.FuY.HeH.JiF.LiuF.CaoM. (2011). Expression of EAAT3 in prefrontal cortex and hippocampus in CPP reinstatement rats induced by morphine. Chin. J. Pathophysiol.27, 17201724.

  • 138

    LiuZ.ZhengJ. F.YangL. Q.YiL.HuB. (2007). Effects of sinomenine on NO/nNOS system in cerebellum and spinal cord of morphine-dependent and withdrawal mice. Sheng Li Xue Bao59, 285292.

  • 139

    LofwallM. R.BabalonisS.NuzzoP. A.SiegelA.CampbellC.WalshS. L. (2013). Efficacy of extended-release tramadol for treatment of prescription opioid withdrawal: a two-phase randomized controlled trial. Drug Alcohol Depend.133, 188197. 10.1016/j.drugalcdep.2013.05.010

  • 140

    LondonE. D.KimesA. S.VaupelD. B. (1995). Inhibitors of nitric oxide synthase and the opioid withdrawal syndrome. NIDA Res. Monogr.147, 170181.

  • 141

    LovellM. A.EhmannW. D.ButlerS. M.MarkesberyW. R. (1995). Elevated thiobarbituric acid-reactive substances and antioxidant enzyme activity in the brain in Alzheimer’s disease. Neurology45, 15941601. 10.1212/wnl.45.8.1594

  • 142

    LuS. C. (2013). Glutathione synthesis. Biochim. Biophys. Acta1830, 31433153. 10.1016/j.bbagen.2012.09.008

  • 143

    LubosE.LoscalzoJ.HandyD. E. (2011). Glutathione peroxidase-1 in health and disease: from molecular mechanisms to therapeutic opportunities. Antioxid. Redox Signal15, 19571997. 10.1089/ars.2010.3586

  • 144

    LudbrookJ. (1998). Multiple comparison procedures updated. Clin. Exp. Pharmacol. Physiol.25, 10321037. 10.1111/j.1440-1681.1998.tb02179.x

  • 145

    LuoF. C.ZhaoL.DengJ.LiangM.ZengX. S.LiuH.et al (2013). Geranylgeranylacetone protects against morphine-induced hepatic and renal damage in mice. Mol. Med. Rep.7, 694700. 10.3892/mmr.2012.1217

  • 146

    LuoY.LiaoC.ChenL.ZhangY.BaoS.DengA.et al (2022). Heroin addiction induces axonal transport dysfunction in the brain detected by in vivo MRI. Neurotox. Res.40, 10701085. 10.1007/s12640-022-00533-3

  • 147

    MaD. K.JangM. H.GuoJ. U.KitabatakeY.ChangM. L.Pow-AnpongkulN.et al (2009). Neuronal activity-induced Gadd45b promotes epigenetic DNA demethylation and adult neurogenesis. Science323, 10741077. 10.1126/science.1166859

  • 148

    MacVicarT. D.MannackL. V.LeesR. M.LaneJ. D. (2015). Targeted siRNA screens identify ER-to-mitochondrial calcium exchange in autophagy and mitophagy responses in RPE1 cells. Int. J. Mol. Sci.16, 1335613380. 10.3390/ijms160613356

  • 149

    MaillouxR. J.McBrideS. L.HarperM.-E. (2013). Unearthing the secrets of mitochondrial ROS and glutathione in bioenergetics. Trends Biochem. Sci.38, 592602. 10.1016/j.tibs.2013.09.001

  • 150

    MajeedN. H.PrzewłockaB.MachelskaH.PrzewłockiR. (1994). Inhibition of nitric oxide synthase attenuates the development of morphine tolerance and dependence in mice. Neuropharmacology33, 189192. 10.1016/0028-3908(94)90006-x

  • 151

    MangasA.CoveñasR.BodetD.GeffardM.AguilarL. A.YajeyaJ. (2007). Immunocytochemical visualization of D-glutamate in the rat brain. Neuroscience144, 654664. 10.1016/j.neuroscience.2006.09.045

  • 152

    MansouriM. T.NaghizadehB.GhorbanzadehB.AmirgholamiN.HoushmandG.AlboghobeishS. (2020). Venlafaxine inhibits naloxone-precipitated morphine withdrawal symptoms: role of inflammatory cytokines and nitric oxide. Metab. Brain Dis.35, 305313. 10.1007/s11011-019-00491-4

  • 153

    MaoJ.SungB.JiR.-R.LimG. (2002). Chronic morphine induces downregulation of spinal glutamate transporters: implications in morphine tolerance and abnormal pain sensitivity. J. Neurosci.22, 83128323. 10.1523/JNEUROSCI.22-18-08312.2002

  • 154

    MarshallD. C.BuccafuscoJ. J. (1985). Supraspinal and spinal mediation of naloxone-induced morphine withdrawal in rats. Brain Res.329, 131142. 10.1016/0006-8993(85)90518-9

  • 155

    MazeI.NestlerE. J. (2011). The epigenetic landscape of addiction. Ann. N. Y. Acad. Sci.1216, 99113. 10.1111/j.1749-6632.2010.05893.x

  • 156

    McClungC. A.NestlerE. J.ZachariouV. (2005). Regulation of gene expression by chronic morphine and morphine withdrawal in the locus ceruleus and ventral tegmental area. J. Neurosci.25, 60056015. 10.1523/JNEUROSCI.0062-05.2005

  • 157

    McHughM. L. (2011). Multiple comparison analysis testing in ANOVA. Biochem. Med. Zagreb.21, 203209. 10.11613/bm.2011.029

  • 158

    MendozaJ.PassafaroR.BabyS.YoungA. P.BatesJ. N.GastonB.et al (2013). L-Cysteine ethyl ester reverses the deleterious effects of morphine on, arterial blood-gas chemistry in tracheotomized rats. Respir. Physiol. Neurobiol.189, 136143. 10.1016/j.resp.2013.07.007

  • 159

    MentchS. J.MehrmohamadiM.HuangL.LiuX.GuptaD.MattocksD.et al (2015). Histone methylation dynamics and gene regulation occur through the sensing of one-carbon metabolism. Cell Metab.22, 861873. 10.1016/j.cmet.2015.08.024

  • 160

    MichaudN.CoutureR. (2003). Cardiovascular and behavioural effects induced by naloxone-precipitated morphine withdrawal in rat: characterization with tachykinin antagonists. Neuropeptides37, 345354. 10.1016/j.npep.2003.09.003

  • 161

    MistryR. J.KlamtF.RamsdenD. B.ParsonsR. B. (2020). Nicotinamide N-methyltransferase expression in SH-SY5Y human neuroblastoma cells decreases oxidative stress. J. Biochem. Mol. Toxicol.34, e22439. 10.1002/jbt.22439

  • 162

    MohammadnejadL.SoltaninejadK.SeyedabadiM.Ghasem PouriS. K.ShokrzadehM.MohammadiH. (2021). Evaluation of mitochondrial dysfunction due to oxidative stress in therapeutic, toxic and lethal concentrations of tramadol. Toxicol. Res. (Camb).10, 11621170. 10.1093/toxres/tfab096

  • 163

    MorganM. M.ChristieM. J. (2011). Analysis of opioid efficacy, tolerance, addiction and dependence from cell culture to human. Br. J. Pharmacol.164, 13221334. 10.1111/j.1476-5381.2011.01335.x

  • 164

    MoriT.ItoS.MatsubayashiK.SawaguchiT. (2007). Comparison of nitric oxide synthase inhibitors, phospholipase A2 inhibitor and free radical scavengers as attenuators of opioid withdrawal syndrome. Behav. Pharmacol.18, 725729. 10.1097/FBP.0b013e3282f18da6

  • 165

    MotaghinejadM.KarimianM.MotaghinejadO.ShababB.YazdaniI.FatimaS. (2015). Protective effects of various dosage of Curcumin against morphine induced apoptosis and oxidative stress in rat isolated hippocampus. Pharmacol. Rep.67, 230235. 10.1016/j.pharep.2014.09.006

  • 166

    MoussaT. A.el-BeihZ. M. (1972). Effects of morphine on the Golgi apparatus and mitochondria of mammalian neurones. Cellule69, 191203.

  • 167

    MozafariN.HassanshahiJ.OstadebrahimiH.ShamsizadehA.AyoobiF.HakimizadehE.et al (2022). Neuroprotective effect of Achillea millefolium aqueous extract against oxidative stress and apoptosis induced by chronic morphine in rat hippocampal CA1 neurons. Acta Neurobiol. Exp. (Wars).82, 179186. 10.55782/ane-2022-016

  • 168

    MukherjeeR.BraschN. E. (2011). Kinetic studies on the reaction between cob(I)alamin and peroxynitrite: rapid oxidation of cob(I)alamin to cob(II)alamin by peroxynitrous acid. Chemistry17, 1172311727. 10.1002/chem.201102267

  • 169

    MunozC.SopjaniM.Dërmaku-SopjaniM.AlmilajiA.FöllerM.LangF. (2012). Downregulation of the osmolyte transporters SMIT and BGT1 by AMP-activated protein kinase. Biochem. Biophys. Res. Commun.422, 358362. 10.1016/j.bbrc.2012.04.092

  • 170

    MuscoliC.CuzzocreaS.NdengeleM. M.MollaceV.PorrecaF.FabriziF.et al (2007). Therapeutic manipulation of peroxynitrite attenuates the development of opiate-induced antinociceptive tolerance in mice. J. Clin. Invest117, 35303539. 10.1172/JCI32420

  • 171

    MyersP. R.MinorR. L. JrGuerraR.JrBatesJ. N.HarrisonD. G. (1990). Vasorelaxant properties of the endothelium-derived relaxing factor more closely resemble S-nitrosocysteine than nitric oxide. Nature345, 161163. 10.1038/345161a0

  • 172

    NicolaouA.AstT.Velasco GarciaC.AndersonM. M.GibbonsJ. M.GibbonsW. A. (1994). In vitro NO and N2O inhibition of the branch point enzyme vitamin B12 dependent methionine synthase from rat brain synaptosomes. Biochem. Soc. T22, 296S. 10.1042/bst022296s

  • 173

    NicolaouA.KenyonS. H.GibbonsJ. M.AstT.GibbonsW. A. (1996). In vitro inactivation of mammalian methionine synthase by nitric oxide. Eur. J. Clin. Invest26, 167170. 10.1046/j.1365-2362.1996.122254.x

  • 174

    NielsenD. A.KreekM. J. (2012). Common and specific liability to addiction: approaches to association studies of opioid addiction. Drug Alcohol Depend.123 (Suppl. 1(0 1)), S33S41. 10.1016/j.drugalcdep.2012.03.026

  • 175

    NishidaK.OhtaY.ItoM.NagamuraY.KitaharaS.FujiiK.et al (1996). Conversion of gamma-glutamylcysteinylethyl ester to glutathione in rat hepatocytes. Biochim. Biophys. Acta1313, 4753. 10.1016/0167-4889(96)00054-7

  • 176

    NodaY.NabeshimaT. (2004). Opiate physical dependence and N-methyl-D-aspartate receptors. Eur. J. Pharmacol.500, 121128. 10.1016/j.ejphar.2004.07.017

  • 177

    NúñezM. T.GallardoV.MuñozP.TapiaV.EsparzaA.SalazarJ.et al (2004). Progressive iron accumulation induces a biphasic change in the glutathione content of neuroblastoma cells. Free Radic. Biol. Med.37, 953960. 10.1016/j.freeradbiomed.2004.06.005

  • 178

    NylanderE.GrönbladhA.ZellerothS.DiwakarlaS.NybergF.HallbergM. (2016). Growth hormone is protective against acute methadone-induced toxicity by modulating the NMDA receptor complex. Neuroscience339, 538547. 10.1016/j.neuroscience.2016.10.019

  • 179

    OhnishiT.BalanS.ToyoshimaM.MaekawaM.OhbaH.WatanabeA.et al (2019). Investigation of betaine as a novel psychotherapeutic for schizophrenia. EBioMedicine45, 432446. 10.1016/j.ebiom.2019.05.062

  • 180

    OhtaH.BatesJ. N.LewisS. J.TalmanW. T. (1997). Actions of S-nitrosocysteine in the nucleus tractus solitarii are unrelated to release of nitric oxide. Brain Res.746, 98104. 10.1016/s0006-8993(96)01188-2

  • 181

    OsmanlıoğluH. Ö.YıldırımM. K.AkyuvaY.YıldızhanK.NazıroğluM. (2020). Morphine induces apoptosis, inflammation, and mitochondrial oxidative stress via activation of TRPM2 channel and nitric oxide signaling pathways in the Hippocampus. Mol. Neurobiol.57, 33763389. 10.1007/s12035-020-01975-6

  • 182

    OstreaE. M. JrChavezC. J.StraussM. E. (1975). A study of factors that influence the severity of neonatal narcotic withdrawal. Addict. Dis.2, 187199.

  • 183

    O-UchiJ.RyuS. Y.JhunB. S.HurstS.SheuS. S. (2014). Mitochondrial ion channels/transporters as sensors and regulators of cellular redox signaling. Antioxid. Redox Signal21, 9871006. 10.1089/ars.2013.5681

  • 184

    PanJ.ZhangQ.ZhangY.OuyangZ.ZhengQ.ZhengR. (2005). Oxidative stress in heroin administered mice and natural antioxidants protection. Life Sci.77, 183193. 10.1016/j.lfs.2004.12.025

  • 185

    PatelJ.McLeodL. E.VriesR. G.FlynnA.WangX.ProudC. G. (2002). Cellular stresses profoundly inhibit protein synthesis and modulate the states of phosphorylation of multiple translation factors. Eur. J. Biochem.269, 30763085. 10.1046/j.1432-1033.2002.02992.x

  • 186

    PearceR.OwenA.DanielS.JennerP.MarsdenC. (1997). Alterations in the distribution of glutathione in the substantia nigra in Parkinson’s disease. J. Neural Transm.104, 661677. 10.1007/BF01291884

  • 187

    PisoniR. L.AckerT. L.LisowskiK. M.LemonsR. M.ThoeneJ. G. (1990). A cysteine-specific lysosomal transport system provides a major route for the delivery of thiol to human fibroblast lysosomes: possible role in supporting lysosomal proteolysis. J. Cell Biol.110, 327335. 10.1083/jcb.110.2.327

  • 188

    RamirezJ. M.VlemincxE.BaertschN. A.SeversL. J. (2022). The sigh and related behaviors. Handb. Clin. Neurol.188, 357372. 10.1016/B978-0-323-91534-2.00015-1

  • 189

    RasmussenK. (1995). The role of the locus coeruleus and N-methyl-D-aspartic acid (NMDA) and AMPA receptors in opiate withdrawal. Neuropsychopharmacology13, 295300. 10.1016/0893-133X(95)00082-O

  • 190

    RossiR.GiustariniD.MilzaniA.Dalle-DonneI. (2009). Cysteinylation and homocysteinylation of plasma protein thiols during ageing of healthy human beings. J. Cell Mol. Med.13, 31313140. 10.1111/j.1582-4934.2008.00417.x

  • 191

    SacknerM. A.LopezJ. R.BanderasV.AdamsJ. A. (2019). Holistic approach to opioid use disorder: think nitric oxide. J. Opioid Manag.15, 521555. 10.5055/jom.2019.0543

  • 192

    SaharanS.MandalP. K. (2014). The emerging role of glutathione in Alzheimer’s disease. J. Alzheimer’s Dis.40, 519529. 10.3233/JAD-132483

  • 193

    SaklothF.PolizuC.BertheratF.ZachariouV. (2020). Regulators of G Protein signaling in analgesia and addiction. Mol. Pharmacol.98, 739750. 10.1124/mol.119.119206

  • 194

    SalminenA.KauppinenA.HiltunenM.KaarnirantaK. (2014). Krebs Cycle Intermediates Regulate DNA and histone methylation: epigenetic impact on the aging process. Ageing Res. Rev.16, 4565. 10.1016/j.arr.2014.05.004

  • 195

    SamadiM.ShakiF.BameriB.FallahM.AhangarN.MohammadiH. (2021). Caffeine attenuates seizure and brain mitochondrial disruption induced by Tramadol: the role of adenosinergic pathway. Drug Chem. Toxicol.44, 613619. 10.1080/01480545.2019.1643874

  • 196

    SamikkannuT.RanjithD.RaoK. V.AtluriV. S.PimentelE.El-HageN.et al (2015). HIV-1 gp120 and morphine induced oxidative stress: role in cell cycle regulation. Front. Microbiol.6, 614. 10.3389/fmicb.2015.00614

  • 197

    SartonE.DahanA.TeppemaL. (1998). Do sex-related differences exist in the respiratory pharmacology of opioids?Adv. Exp. Med. Biol.450, 141145. 10.1007/978-1-4757-9077-1_23

  • 198

    SecklerJ. M.GrossfieldA.MayW. J.GetsyP. M.LewisS. J. (2022). Nitrosyl factors play a vital role in the ventilatory depressant effects of fentanyl in unanesthetized rats. Biomed. and Pharmacother.146, 112571. 10.1016/j.biopha.2021.112571

  • 199

    SecklerJ. M.LewisS. J. (2020). Advances in D-amino acids in neurological research. Int. J. Mol. Sci.21, 7325. 10.3390/ijms21197325

  • 200

    SecklerJ. M.MeyerN. M.BurtonS. T.BatesJ. N.GastonB.LewisS. J. (2017). Detection of trace concentrations of S-nitrosothiols by means of a capacitive sensor. PLoS One12, e0187149. 10.1371/journal.pone.0187149

  • 201

    SecklerJ. M.ShenJ.LewisT. H. J.AbdulameerM. A.ZamanK.PalmerL. A.et al (2020). NADPH diaphorase detects S-nitrosylated proteins in aldehyde-treated biological tissues. Sci. Rep.10, 21088. 10.1038/s41598-020-78107-6

  • 202

    SemenzaE. R.HarrazM. M.AbramsonE.MallaA. P.VasavdaC.GadallaM. M.et al (2021). D-cysteine is an endogenous regulator of neural progenitor cell dynamics in the mammalian brain. Proc. Natl. Acad. Sci. U. S. A.118, e2110610118. 10.1073/pnas.2110610118

  • 203

    SethD.StamlerJ. S. (2011). The SNO-proteome: causation and classifications. Curr. Opin. Chem. Biol.15, 129136. 10.1016/j.cbpa.2010.10.012

  • 204

    ShenD.DaltonT. P.NebertD. W.ShertzerH. G. (2005). Glutathione redox state regulates mitochondrial reactive oxygen production. J. Biol. Chem.280, 2530525312. 10.1074/jbc.M500095200

  • 205

    ShibaniF.SahamsizadehA.FatemiI.AllahtavakoliM.HasanshahiJ.RahmaniM.et al (2019). Effect of oleuropein on morphine-induced hippocampus neurotoxicity and memory impairments in rats. Naunyn Schmiedeb. Arch. Pharmacol.392, 13831391. 10.1007/s00210-019-01678-3

  • 206

    Simmons-WillisT. A.KohA. S.ClarksonT. W.BallatoriN. (2002). Transport of a neurotoxicant by molecular mimicry: the methylmercury-L-cysteine complex is a substrate for human L-type large neutral amino acid transporter (LAT) 1 and LAT2. Biochem. J.367, 239246. 10.1042/BJ20020841

  • 207

    SinghP.SharmaB.GuptaS.SharmaB. M. (2015). In vivo and in vitro attenuation of naloxone-precipitated experimental opioid withdrawal syndrome by insulin and selective KATP channel modulator. Psychopharmacol. Berl.232, 465475. 10.1007/s00213-014-3680-5

  • 208

    SinghalN. K.LiS.ArningE.AlkhayerK.ClementsR.SarcykZ.et al (2015). Changes in methionine metabolism and histone H3 trimethylation are linked to mitochondrial defects in multiple sclerosis. J. Neurosci.35, 1517015186. 10.1523/JNEUROSCI.4349-14.2015

  • 209

    SkoulisN. P.JamesR. C.HarbisonR. D.RobertsS. M. (1989). Perturbation of glutathione by a central action of morphine. Toxicology57, 287302. 10.1016/0300-483x(89)90117-0

  • 210

    SmithZ. D.MeissnerA. (2013). DNA methylation: roles in mammalian development. Nat. Rev. Genet.14, 204220. 10.1038/nrg3354

  • 211

    SouzaL. K.AraújoT. S.SousaN. A.SousaF. B.NogueiraK. M.NicolauL. A.et al (2017). Evidence that d-cysteine protects mice from gastric damage via hydrogen sulfide produced by d-amino acid oxidase. Nitric Oxide64, 16. 10.1016/j.niox.2017.01.010

  • 212

    SpeckerS.WananukulW.HatsukamiD.NolinK.HookeL.KreekM. J.et al (1998). Effects of dynorphin A(1-13) on opiate withdrawal in humans. Psychopharmacol. Berl.137, 326332. 10.1007/s002130050626

  • 213

    StamlerJ. S. (1995). S-nitrosothiols and the bioregulatory actions of nitrogen oxides through reactions with thiol groups. Curr. Top. Microbiol. Immunol.196, 1936. 10.1007/978-3-642-79130-7_4

  • 214

    StipanukM. H.SimmonsC. R.KarplusP. A.DominyJ. E.Jr (2011). Thiol dioxygenases: unique families of cupin proteins. Amino Acids41, 91102. 10.1007/s00726-010-0518-2

  • 215

    StipanukM. H.UekiI.DominyJ. E.JrSimmonsC. R.HirschbergerL. L. (2009). Cysteine dioxygenase: a robust system for regulation of cellular cysteine levels. Amino Acids37, 5563. 10.1007/s00726-008-0202-y

  • 216

    StomberskiC. T.HessD. T.StamlerJ. S. (2019). Protein S-nitrosylation: determinants of specificity and enzymatic regulation of S-Nitrosothiol-Based signaling. Antioxid. Redox Signal30, 13311351. 10.1089/ars.2017.7403

  • 217

    SunH.MazeI.DietzD. M.ScobieK. N.KennedyP. J.Damez-WernoD.et al (2012). Morphine epigenomically regulates behavior through alterations in histone H3 lysine 9 dimethylation in the nucleus accumbens. J. Neurosci.32, 1745417464. 10.1523/JNEUROSCI.1357-12.2012

  • 218

    SuzukiM. M.BirdA. (2008). DNA methylation landscapes: provocative insights from epigenomics. Nat. Rev. Genet.9, 465476. 10.1038/nrg2341

  • 219

    SzwergoldB. S. (2006). Alpha-thiolamines such as cysteine and cysteamine act as effective transglycating agents due to formation of irreversible thiazolidine derivatives. Med. Hypotheses66, 698707. 10.1016/j.mehy.2005.10.029

  • 220

    Tapia-ArizmendiG.Garcia-EstradaJ.Feria-VelascoA.AlemanV. (1987). Structural changes in caudate nucleus, cerebral cortex and hippocampus induced by morphine. Light microscopy study. Gen. Pharmacol.18, 321325. 10.1016/0306-3623(87)90019-x

  • 221

    TapocikJ. D.LuuT. V.MayoC. L.WangB. D.DoyleE.LeeA. D.et al (2013). Neuroplasticity, axonal guidance and micro-RNA genes are associated with morphine self-administration behavior. Addict. Biol.18, 480495. 10.1111/j.1369-1600.2012.00470.x

  • 222

    TirmensteinM. A.HuC. X.ScicchitanoM. S.NarayananP. K.McFarlandD. C.ThomasH. C.et al (2005). Effects of 6-hydroxydopamine on mitochondrial function and glutathione status in SH-SY5Y human neuroblastoma cells. Toxicol Vitro19, 471479. 10.1016/j.tiv.2005.01.006

  • 223

    TokuyamaS.FengY.WakabayashiH.HoI. K. (1995). Ca2+ channel blocker, diltiazem, prevents physical dependence and the enhancement of protein kinase C activity by opioid infusion in rats. Eur. J. Pharmacol.279, 9398. 10.1016/0014-2999(95)00140-g

  • 224

    TownsendD. M.TewK. D.TapieroH. (2003). The importance of glutathione in human disease. Biomed. Pharm.57, 145155. 10.1016/s0753-3322(03)00043-x

  • 225

    TramullasM.Martínez-CuéC.HurléM. A. (2007). Chronic methadone treatment and repeated withdrawal impair cognition and increase the expression of apoptosis-related proteins in mouse brain. Psychopharmacol. Berl.193, 107120. 10.1007/s00213-007-0751-x

  • 226

    TramullasM.Martínez-CuéC.HurléM. A. (2008). Chronic administration of heroin to mice produces up-regulation of brain apoptosis-related proteins and impairs spatial learning and memory. Neuropharmacology54, 640652. 10.1016/j.neuropharm.2007.11.018

  • 227

    TrivediM.ShahJ.HodgsonN.ByunH. M.DethR. (2014a). Morphine induces redox-based changes in global DNA methylation and retrotransposon transcription by inhibition of excitatory amino acid transporter type 3-mediated cysteine uptake. Mol. Pharmacol.85, 747757. 10.1124/mol.114.091728

  • 228

    TrivediM.ZhangY.Lopez-ToledanoM.ClarkeA.DethR. (2016). Differential neurogenic effects of casein-derived opioid peptides on neuronal stem cells: implications for redox-based epigenetic changes. J. Nutr. Biochem.37, 3946. 10.1016/j.jnutbio.2015.10.012

  • 229

    TrivediM. S.DethR. (2015). Redox-based epigenetic status in drug addiction: a potential contributor to gene priming and a mechanistic rationale for metabolic intervention. Front. Neurosci.8, 444. 10.3389/fnins.2014.00444

  • 230

    TrivediM. S.HodgsonN. W.WalkerS. J.TrooskensG.NairV.DethR. C. (2015). Epigenetic effects of casein-derived opioid peptides in SH-SY5Y human neuroblastoma cells. Nutr. Metab. (Lond).12, 54. 10.1186/s12986-015-0050-1

  • 231

    TrivediM. S.ShahJ. S.Al-MughairyS.HodgsonN. W.SimmsB.TrooskensG. A.et al (2014b). Food-derived opioid peptides inhibit cysteine uptake with redox and epigenetic consequences. J. Nutr. Biochem.25, 10111018. 10.1016/j.jnutbio.2014.05.004

  • 232

    TsakovaA.SurchevaS.SimeonovaK.AltankovaI.MarinovaT.UsunoffK.et al (2015). Nitroxidergic modulation of behavioural, cardiovascular and immune responses, and brain NADPH diaphorase activity upon morphine tolerance/dependence in rats. Biotechnol. Biotechnol. Equip.29, 92100. 10.1080/13102818.2014.990924

  • 233

    TurellL.RadiR.AlvarezB. (2013). The thiol pool in human plasma: the central contribution of albumin to redox processes. Free Radic. Biol. Med.65, 244253. 10.1016/j.freeradbiomed.2013.05.050

  • 234

    UelandP. M. (2011). Choline and betaine in health and disease. J. Inherit. Metab. Dis.34, 315. 10.1007/s10545-010-9088-4

  • 235

    UelandP. M.HolmP. I.HustadS. (2005). Betaine: a key modulator of one-carbon metabolism and homocysteine status. Clin. Chem. Lab. Med.43, 10691075. 10.1515/CCLM.2005.187

  • 236

    UesonoY.TohE. A. (2002). Transient inhibition of translation initiation by osmotic stress. J. Biol. Chem.277, 1384813855. 10.1074/jbc.M108848200

  • 237

    UndemB. J.KajekarR.HunterD. D.MyersA. C. (2000). Neural integration and allergic disease. J. Allergy Clin. Immunol.106 (5 Suppl. l), S213S220. 10.1067/mai.2000.110153

  • 238

    VaupelD. B.KimesA. S.LondonE. D. (1995a). Nitric oxide synthase inhibitors. Preclinical studies of potential use for treatment of opioid withdrawal. Neuropsychopharmacology13, 315322. 10.1016/0893-133X(95)00138-4

  • 239

    VaupelD. B.KimesA. S.LondonE. D. (1995b). Comparison of 7-nitroindazole with other nitric oxide synthase inhibitors as attenuators of opioid withdrawal. Psychopharmacol. Berl.118, 361368. 10.1007/BF02245935

  • 240

    VolkowN. D.MichaelidesM.BalerR. (2019). The neuroscience of drug reward and addiction. Physiol. Rev.99, 21152140. 10.1152/physrev.00014.2018

  • 241

    WallensteinS.ZuckerC. L.FleissJ. L. (1980). Some statistical methods useful in circulation research. Circ. Res.47, 19. 10.1161/01.res.47.1.1

  • 242

    WangQ.Liu-ChenL.-Y.TraynorJ. R. (2009). Differential modulation of μ- and δ-opioid receptor agonists by endogenous RGS4 protein in SH-SY5Y cells. J. Biol. Chem.284, 1835718367. 10.1074/jbc.M109.015453

  • 243

    WangS. T.ChenH. W.SheenL. Y.LiiC. K. (1997). Methionine and cysteine affect glutathione level, glutathione-related enzyme activities and the expression of glutathione S-transferase isozymes in rat hepatocytes. J. Nutr.127, 21352141. 10.1093/jn/127.11.2135

  • 244

    WangY.BollardM. E.NicholsonJ. K.HolmesE. (2006). Exploration of the direct metabolic effects of mercury II chloride on the kidney of Sprague-Dawley rats using high-resolution magic angle spinning 1H NMR spectroscopy of intact tissue and pattern recognition. J. Pharm. Biomed. Anal.40, 375381. 10.1016/j.jpba.2005.07.019

  • 245

    WangY.ZhangM.LiZ.YueJ.XuM.ZhangY.et al (2019). Fine particulate matter induces mitochondrial dysfunction and oxidative stress in human SH-SY5Y cells. Chemosphere218, 577588. 10.1016/j.chemosphere.2018.11.149

  • 246

    WangZ.BilskyE. J.WangD.PorrecaF.SadéeW. (1999). 3-Isobutyl-1-methylxanthine inhibits basal mu-opioid receptor phosphorylation and reverses acute morphine tolerance and dependence in mice. Eur. J. Pharmacol.371, 19. 10.1016/s0014-2999(99)00131-4

  • 247

    WardP.MossH. G.BrownT. R.KalivasP.JenkinsD. D. (2020). N-acetylcysteine mitigates acute opioid withdrawal behaviors and CNS oxidative stress in neonatal rats. Pediatr. Res.88, 7784. 10.1038/s41390-019-0728-6

  • 248

    WilckenD. E.GuptaV. J. (1979). Cysteine-homocysteine mixed disulphide: differing plasma concentrations in normal men and women. Clin. Sci. (Lond).57, 211215. 10.1042/cs0570211

  • 249

    WinerB. J. (1971). Statistical principles of experimental design. McGraw-Hill Book Co., 752809.

  • 250

    WróbelM.UbukaT.YaoW. B.AbeT. (1997). Effect of glucose-cysteine adduct on cysteine desulfuration in Guinea pig tissues. Physiol. Chem. Phys. Med. NMR29, 1114.

  • 251

    XuB.WangZ.LiG.LiB.LinH.ZhengR.et al (2006). Heroin-administered mice involved in oxidative stress and exogenous antioxidant-alleviated withdrawal syndrome. Basic Clin. Pharmacol. Toxicol.99, 153161. 10.1111/j.1742-7843.2006.pto_461.x

  • 252

    XuL.ChenJ.GaoJ.YuH.YangP. (2015). Crosstalk of homocysteinylation, methylation and acetylation on histone H3. Analyst140, 30573063. 10.1039/c4an02355b

  • 253

    XuN.-J.BaoL.FanH.-P.BaoG.-B.PuL.LuY.-J.et al (2003). Morphine withdrawal increases glutamate uptake and surface expression of glutamate transporter GLT1 at hippocampal synapses. J. Neurosci.23, 47754784. 10.1523/JNEUROSCI.23-11-04775.2003

  • 254

    YamaguchiK.HosokawaY. (1987). Cysteine dioxygenase. Methods Enzymol.143, 395403. 10.1016/0076-6879(87)43069-3

  • 255

    YangL.WangS.SungB.LimG.MaoJ. (2008). Morphine induces ubiquitin-proteasome activity and glutamate transporter degradation. J. Biol. Chem.283, 2170321713. 10.1074/jbc.M800809200

  • 256

    YayehT.YunK.JangS.OhS. (2016). Morphine dependence is attenuated by red ginseng extract and ginsenosides Rh2, Rg3, and compound K. J. Ginseng Res.40, 445452. 10.1016/j.jgr.2016.08.006

  • 257

    YunJ.LeeY.YunK.OhS. (2015). Bergenin decreases the morphine-induced physical dependence via antioxidative activity in mice. Arch. Pharm. Res.38, 12481254. 10.1007/s12272-014-0534-y

  • 258

    YunJ.OliynykS.LeeY.KimJ.YunK.JeonR.et al (2017). Ajoene restored behavioral patterns and liver glutathione level in morphine treated C57BL6 mice. Arch. Pharm. Res.40, 106111. 10.1007/s12272-016-0773-1

  • 259

    ZhaoL.ZhuY.WangD.ChenM.GaoP.XiaoW.et al (2010). Morphine induces Beclin 1- and ATG5-dependent autophagy in human neuroblastoma SH-SY5Y cells and in the rat hippocampus. Autophagy6, 386394. 10.4161/auto.6.3.11289

  • 260

    ZhouY.DanboltN. C. (2013). GABA and glutamate transporters in brain. Front. Endocrinol. (Lausanne)4, 165. 10.3389/fendo.2013.00165

Summary

Keywords

morphine, addiction, dependence, D-cysteine ethyl ester, betaine, human SH-SY5Y cells, rats

Citation

McDonough J, Singhal NK, Getsy PM, Knies K, Knauss ZT, Mueller D, Bates JN, Damron DS and Lewis SJ (2024) The epigenetic signatures of opioid addiction and physical dependence are prevented by D-cysteine ethyl ester and betaine. Front. Pharmacol. 15:1416701. doi: 10.3389/fphar.2024.1416701

Received

12 April 2024

Accepted

29 July 2024

Published

30 August 2024

Volume

15 - 2024

Edited by

Sathish Kumar Natarajan, University of Nebraska-Lincoln, United States

Reviewed by

Fatemeh Saheb Sharif-Askari, University of Sharjah, United Arab Emirates

Idaira Oliva, Indiana University, United States

Updates

Copyright

*Correspondence: Stephen J. Lewis,

† Present address: James N. Bates, Atelerix Life Sciences Inc., Charlottesville, VA, United States

Disclaimer

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.

Outline

Figures

Cite article

Copy to clipboard


Export citation file


Share article

Article metrics