Targeting mitochondrial dynamics of morphine-responsive dopaminergic neurons ameliorates opiate withdrawal.

Converging studies demonstrate the dysfunction of the dopaminergic neurons following chronic opioid administration. However, the therapeutic strategies targeting opioid-responsive dopaminergic ensembles that contribute to the development of opioid withdrawal remain to be elucidated. Here, we used the neuronal activity-dependent Tet-Off system to label dopaminergic ensembles in response to initial morphine exposure (Mor-Ens) in the ventral tegmental area (VTA). Fiber optic photometry recording and transcriptome analysis revealed downregulated spontaneous activity and dysregulated mitochondrial respiratory, ultrastructure, and oxidoreductase signal pathways after chronic morphine administration in these dopaminergic ensembles. Mitochondrial fragmentation and the decreased mitochondrial fusion gene mitofusin 1 (Mfn1) were found in these ensembles after prolonged opioid withdrawal. Restoration of Mfn1 in the dopaminergic Mor-Ens attenuated excessive oxidative stress and the development of opioid withdrawal. Administration of Mdivi-1, a mitochondrial fission inhibitor, ameliorated the mitochondrial fragmentation and maladaptation of the neuronal plasticity in these Mor-Ens, accompanied by attenuated development of opioid withdrawal after chronic morphine administration, without affecting the analgesic effect of morphine. These findings highlighted the plastic architecture of mitochondria as a potential therapeutic target for opioid analgesic-induced substance use disorders.

ZSCAN25 methylation predicts seizures and severe alcohol withdrawal syndrome.

Currently, clinicians use their judgement and indices such as the Prediction of Alcohol Withdrawal Syndrome Scale (PAWSS) to determine whether patients are admitted to hospitals for consideration of withdrawal syndrome (AWS). However, only a fraction of those admitted will experience severe AWS. Previously, we and others have shown that epigenetic indices, such as the Alcohol T-Score (ATS), can quantify recent alcohol consumption. However, whether these or other alcohol biomarkers, such as carbohydrate deficient transferrin (CDT), could identify those at risk for severe AWS is unknown. To determine this, we first conducted genome-wide DNA methylation analyses of subjects entering and exiting alcohol treatment to identify loci whose methylation quickly reverted as a function of abstinence. We then tested whether methylation at a rapidly reverting locus, cg07375256, or other existing metrics including PAWSS scores, CDT levels, or ATS, could predict outcome in 125 subjects admitted for consideration of AWS. We found that PAWSS did not significantly predict severe AWS nor seizures. However, methylation at cg07375256 (ZSCAN25) and CDT strongly predicted severe AWS with ATS (p < 0.007) and cg07375256 (p < 6 × 10-5) methylation also predicting AWS associated seizures. We conclude that epigenetic methods can predict those likely to experience severe AWS and that the use of these or similar Precision Epigenetic approaches could better guide AWS management.

Impulsivity and aggression in alcohol withdrawal syndrome is modulated by the interaction of ZNF804A and mTOR polymorphism.

Alcohol withdrawal syndrome (AWS) is a poorly studied phenotype of alcohol use disorder. Understanding the relationship between allelic interactions and AWS-related impulsivity and aggression could have significant implications. This study aimed to investigate the main and interacting effects of ZNF804A and mTOR on impulsivity and aggression during alcohol withdrawal. 446 Chinese Han adult males with alcohol dependence were included in the study. Impulsivity and aggression were assessed, and genomic DNA was genotyped. Single gene analysis showed that ZNF804A rs1344706 (A allele/CC homozygote) and mTOR rs1057079 (C allele/TT homozygote) were strongly associated with AWS-related impulsivity and aggression. In the allelic group, MANOVA revealed a significant gene x gene interaction, suggesting that risk varied systematically depending on both ZNF804A and mTOR alleles. Additionally, a significant interactive effect of ZNF804A rs1344706 and mTOR rs7525957 was found on motor impulsivity and physical aggression, and the ZNF804A rs1344706 gene variant had significant effects on motor impulsivity and physical aggression only in mTOR rs7525957 TT homozygous carriers. The study showed that specific allelic combinations of ZNF804A and mTOR may have protective or risk-enhancing effects on AWS-related impulsivity and aggression.

Transcriptional Dysregulation of Cholesterol Synthesis Underlies Hyposensitivity to GABA in the Ventral Tegmental Area During Acute Alcohol Withdrawal.

BACKGROUND: The ventral tegmental area (VTA) is a dopaminergic brain area that is critical in the development and maintenance of addiction. During withdrawal from chronic ethanol exposure, the response of VTA neurons to GABA (gamma-aminobutyric acid) is reduced through an epigenetically regulated mechanism. In the current study, a whole-genome transcriptomic approach was used to investigate the underlying molecular mechanism of GABA hyposensitivity in the VTA during withdrawal after chronic ethanol exposure. METHODS: We performed RNA sequencing of the VTA of Sprague Dawley male rats withdrawn for 24 hours from a chronic ethanol diet as well as sequencing of the VTA of control rats fed the Lieber-DeCarli diet. RNA sequencing data were analyzed using weighted gene coexpression network analysis to identify modules that contained coexpressed genes. Validation was performed with quantitative polymerase chain reaction, gas chromatography-mass spectrometry, and electrophysiological assays. RESULTS: Pathway and network analysis of weighted gene coexpression network analysis module 1 revealed a significant downregulation of genes associated with the cholesterol synthesis pathway. Consistent with this association, VTA cholesterol levels were significantly decreased during withdrawal. Chromatin immunoprecipitation indicated a decrease in levels of acetylated H3K27 at the transcriptional control regions of these genes. Electrophysiological studies in VTA slices demonstrated that GABA hyposensitivity during withdrawal was normalized by addition of exogenous cholesterol. In addition, inhibition of cholesterol synthesis produced GABA hyposensitivity, which was reversed by adding exogenous cholesterol to VTA slices. CONCLUSIONS: These results suggest that decreased expression of cholesterol synthesis genes may regulate GABA hyposensitivity of VTA neurons during alcohol withdrawal. Increasing cholesterol levels in the brain may be a novel avenue for therapeutic intervention to reverse detrimental effects of chronic alcohol exposure.

BDNF CpG methylation and serum levels covary during alcohol withdrawal in patients with alcohol use disorder: A pilot study.

OBJECTIVES: Brain-derived neurotrophic factor (BDNF) levels vary in various conditions including alcohol use disorder (AUD). We aimed to identify drivers of these variations. METHODS: Twelve patients with AUD were assessed at hospitalisation for alcohol withdrawal and four months later. We looked for associations between the change in serum BDNF levels and (1) length of abstinence, (2) anxiety (Hamilton Anxiety Scale) and depression (Beck-Depression Inventory), (3) one functional BDNF genotype (rs6265) and (4) methylation levels of 12 CpG sites within the BDNF gene (located in exons I, IV and IX). RESULTS: While abstinence remained, serum BDNF level increased. This increase correlated with the variation of methylation levels of the BDNF gene, and more specifically of exon I. We found no significant effect of length of abstinence, rs6265, depression or anxiety on serum BDNF level. CONCLUSIONS: Epigenetic regulation of the BDNF gene may be involved in variations of BDNF blood level associated with alcohol abstinence.

The role of miRNA-144-3p/Oprk1/KOR in nicotine dependence and nicotine withdrawal in male rats.

INTRODUCTION: The kappa-opioid receptor (KOR) has been implicated in mediating the behavioral and biochemical effects associated with nicotine reward and withdrawal; however, its underlying mechanisms remain to be further explored. METHODS: Adult male Sprague-Dawley rats were used to establish a nicotine dependence and withdrawal model by injecting nicotine (3 mg/kg/day, s.c.) or vehicle for 14 days, followed by the termination of nicotine for 7 days. Body weight gain, pain behaviors, and withdrawal scores were assessed in succession. MicroRNA (miRNA) sequencing was performed, and quantitative real-time PCR was used to detect the expression of candidate miRNAs and Oprk1. Western blotting was performed to examine KOR protein expression of KOR. Luciferase assay was conducted to validate the relationship of certain miRNAs/Oprk1. RESULTS: The behavioral results showed that nicotine dependence and withdrawal induced behavioral changes. Biochemical analyses demonstrated that miR-144-3p expression decreased and Oprk1/KOR expression increased in the prefrontal cortex, nucleus accumben, and hippocampus. Further investigation suggested that miR-144-3p exerted an inhibitory effect on Oprk1 expression in PC12 cells. CONCLUSIONS: This study revealed that miR-144-3p/Oprk1/KOR might be a potential pathway underlying the adverse effects induced by nicotine dependence and withdrawal, and might provide a novel therapeutic target for smoking cessation. IMPLICATIONS: This study demonstrates an impact of nicotine dependence and nicotine withdrawal on behavioral outcomes and the expressions of miR-144-3p/Oprk1/KOR in male rats. These findings have important translational implications given the continued use of nicotine and the difficulty in smoking cessation worldwide, which can be applied to alleviated the adverse effects induced by nicotine dependence and withdrawal, thus assist smokers to quit smoking.

Association of OPRK1 rs963549 and rs997917 polymorphisms with opioid use disorder and related phenotypes.

Aim: To evaluate the association between OPRK1 rs963549 and rs997917 and opioid use disorder (OUD) and related phenotypes. Methods: A sample of 208 individuals with (n = 100) and without (n = 108) OUD were enrolled. OPRK1 rs963549 and rs997917 were analyzed by PCR-RFLP. Craving, opioid withdrawal and the intensity of depressive and anxiety symptoms were measured by the appropriate scales. Results: OPRK1 rs963549 variation showed a trend of association with decreased opioid withdrawal. No significant associations were found between OPRK1 rs963549 and rs997917 polymorphisms and craving, depression or anxiety symptoms. Neither single OPRK1 SNPs nor OPRK1 haplotypes were associated with OUD. Conclusion: Our results could be useful for treatment failures of individuals who experience greater opioid withdrawal due to their OPRK1 rs963549 genotypes.

Polygenic influences on the behavioral effects of alcohol withdrawal in a mixed-ancestry population from the collaborative study on the genetics of alcoholism (COGA).

Alcohol withdrawal (AW) is a feature of alcohol use disorder that may occur in up to half of individuals with chronic, heavy alcohol consumption whenever alcohol use is abruptly stopped or significantly reduced. To date, few genes have been robustly associated with AW; this may be partly due to most studies defining AW as a binary construct despite the multiple symptoms and their range in severity from mild to severe. The current study examined the effects of genome-wide loci on a factor score for AW in high risk and community family samples in the Collaborative Study for the Genetics of Alcoholism (COGA). In addition, we tested whether differentially expressed genes associated with alcohol withdrawal in model organisms are enriched in human genome-wide association study (GWAS) effects. Analyses employed roughly equal numbers of males and females (mean age 35, standard deviation = 15; total N = 8009) and included individuals from multiple ancestral backgrounds. Genomic data were imputed to the HRC reference panel and underwent strict quality control procedures using Plink2. Analyses controlled for age, sex, and population stratification effects using ancestral principal components. We found support that AW is a polygenic disease (SNP-heritability = 0.08 [95 % CI = 0.01, 0.15; pedigree-based heritability = 0.12 [0.08,0.16]. We identified five single nucleotide variants that met genomewide significance, some of which have previously been associated with alcohol phenotypes. Gene-level analyses suggest a role for COL19A1 in AW; H-MAGMA analyses implicated 12 genes associated with AW. Cross-species enrichment analyses indicated that variation within genes identified in model organism studies explained <1 % of the phenotypic variability in human AW. Notably, the surrounding regulatory regions of model organism genes explained more variance than expected by chance, indicating that these regulatory regions and gene sets may be important for human AW. Lastly, when comparing the overlap in genes identified from the human GWAS and H-MAGMA analyses with the genes identified from the animal studies, there was modest overlap, indicating some convergence between the methods and organisms.

Identification of candidate genes for nicotine withdrawal in C57BL/6J × DBA/2J recombinant inbred mice.

Nicotine is the reinforcing ingredient in tobacco. Following chronic exposure, sudden cessation of nicotine use produces negative symptoms of withdrawal that contribute to dependence. The molecular mechanisms underlying nicotine withdrawal behaviors, however, are poorly understood. Using recombinant inbred mice, chronic nicotine was delivered by minipump and withdrawal induced using mecamylamine. Somatic signs of withdrawal, and anxiety-like behavior using elevated plus maze, were then assessed. Interval mapping was used to identify associations between genetic variation and withdrawal behaviors, and with basal gene expression. Differential gene expression following nicotine exposure and withdrawal was also assessed in progenitor mice using microarrays. Quantitative trait loci mapping identified chromosome intervals with significant genetic associations to somatic signs of withdrawal or withdrawal-induced anxiety-like behavior. Using bioinformatics, and association with basal gene expression in nucleus accumbens, we implicated Rb1, Bnip3l, Pnma2, Itm2b, and Kif13b as candidate genes for somatic signs of withdrawal, and Galr1, which showed trans-regulation from a region of chromosome 14 that was associated with somatic signs of withdrawal. Candidate genes within the chromosome 9 region associated with anxiety-like withdrawal behavior included Dixdc1, Ncam1, and Sorl1. Bioinformatics identified six genes that were also significantly associated with nicotine or alcohol traits in recent human genome-wide association studies. Withdrawal-associated somatic signs and anxiety-like behavior had strong non-overlapping genetic associations, respectively, with regions of chromosome 14 and chromosome 9. Genetic, behavioral and gene expression correlations, and bioinformatics analysis identified several candidate genes that may represent novel molecular targets for modulating nicotine withdrawal symptoms.

CYP3A4*22 and CYP3A5*3 impact efficacy and safety of diazepam in patients with alcohol withdrawal syndrome.

BACKGROUND: Diazepam is one of the most commonly prescribed pharmaceuticals for the treatment of alcohol withdrawal syndrome (AWS). However, diazepam sometimes is ineffective, and some patients experience dose-dependent adverse drug reactions (ADR). Previous studies have shown that diazepam metabolism involves the CYP3A4 and CYP3A5 isoenzymes, whose activity is highly variable between individuals, which may contribute to differences in clinical response. PURPOSE: The study aimed to investigate the effects of the genetic polymorphisms CYP3A4*22 and CYP3A5*3 on the efficacy and safety of diazepam in patients with AWS. MATERIALS AND METHODS: One hundred male AWS patients received 30 mg/day diazepam by intramuscular injections for 5 days. Genotyping for CYP3A4*22 (rs35599367) and CYP3A5*3 (rs776746) was performed by real-time polymerase chain reaction with allele-specific hybridization. The efficacy and safety assessments were performed using psychometric scales. RESULTS: Patients who carry CT and TT genotypes by polymorphic marker C > T intron 6 (rs35599367) of the CYP3A4 gene had a higher risk for ADR and demonstrated lower safety of diazepam therapy (p < 0.001; two-way ANOVA). CONCLUSION: These results suggest that genotyping for common CYP3A variants might have the potential to guide benzodiazepine withdrawal treatment.

Prospective DNA Methylation Analysis of the CpG GABRA2 Receptor Subunit in Alcohol Dependence during Detoxification.

Background and Objectives: Variants of GABRA2 have been repeatedly associated with alcohol dependence risk. However, no study investigated potential epigenetic alterations in the GABRA2 gene in alcohol-dependent (AD) subjects during alcohol withdrawal. We investigated DNA methylation pattern in the regulatory region of GABRA2 gene in peripheral leukocytes of AD patients and controls. Further, GABRA2 methylation patterns were analysed in neuroblastoma cells under ethanol exposure and withdrawal. Materials and Methods: In the present study, blood samples were obtained from 41 AD subjects on the day of inpatient admission, after the first and second week of inpatient treatment. The comparison group included 47 healthy controls. GABRA2 methylation of 4 CpG sites in the CpG island was compared to neuroblastoma cells which were exposed to 100 mM of ethanol for 2, 5 and 9 days, followed by a withdrawal interval of 4 days. Results: no significant differences in GABRA2 methylation patterns were found in AD subjects over time and vs. controls, after controlling for age. Further, no influence of withdrawal severity, alcohol consumption before admission and other alcohol dependence characteristics were found. Conclusions: The results indicate that GABRA2 methylation in AD individuals and in a cell model is unaffected by alcohol exposition and withdrawal. Influences of GABRA2 on characteristics of alcohol dependence may be exerted by mechanisms other than epigenetic alterations related to alcohol intoxication or withdrawal.

Genetic and genomic signatures in ethanol withdrawal seizure-prone and seizure-resistant mice implicate genes involved in epilepsy and neuronal excitability.

Alcohol withdrawal is a clinically important consequence and potential driver of Alcohol Use Disorder. However, susceptibility to withdrawal symptoms, ranging from craving and anxiety to seizures and delirium, varies greatly. Selectively bred Withdrawal Seizure-Prone (WSP) and Seizure-Resistant (WSR) mice are an animal model of differential susceptibility to withdrawal and phenotypes with which withdrawal severity correlates. To identify innate drivers of alcohol withdrawal severity, we performed a multi-omic study of the WSP and WSR lines and F2 mice derived from them, using genomic, genetic, and transcriptomic analyses. Genes implicated in seizures and epilepsy were over-represented among those that segregated between WSP and WSR mice and that displayed differential expression in F2 mice high and low in withdrawal. Quantitative trait locus (QTL) analysis of ethanol withdrawal convulsions identified several genome-wide significant loci and pointed to genes that modulate potassium channel function and neural excitability. Perturbations of expression of genes involved in synaptic transmission, including GABAergic and glutamatergic genes, were prominent in prefrontal cortex transcriptome. Expression QTL (eQTL) analysis fine mapped genes within the peak ethanol withdrawal QTL regions. Genetic association analysis in human subjects provided converging evidence for the involvement of those genes in severity of alcohol withdrawal and dependence. Our results reveal a polygenic network and neural signaling pathways contributing to ethanol withdrawal seizures and related phenotypes that overlap with genes modulating epilepsy and neuronal excitability.

[Contents of BDNF, miR-30a-5p and miR-122 during alcohol withdrawal syndrome]. / Uroven' BDNF, miR-30a-5p i miR-122 v syvorotke krovi v dinamike sindroma otmeny alkogolia.

Some BDNF (brain-derived neurotrophic factor)-targeted microRNAs such as miR-30a-5p associate with alcohol dependence phenomenon however their relationship with AWS is not described. We aimed to measure serum BDNF concentration and relative content of miR-30a-5p over the course of alcohol abstinence and compare obtained results with clinics of AWS. Additionally, we studied relative serum content of miR-30a-5p, a microRNA which does not target BDNF but relates to alcohol use disorder. Serum BDNF concentration increased over the course of alcohol abstinence, contrary relative content of miR-122 but not miR-30a-5p decreased. Moreover, during AWS miR-122 but miR-30a-5p negatively correlated with serum BDNF concentrations. Relative content of miR-122 negatively correlated with depression and state anxiety levels on 8th day of abstinence. According to multiple regressions on 21st day of abstinence alcohol craving and cognitive disturbances may be predictors of serum BDNF concentration, and vice versa. Thus, serum BDNF concentration and relative content of miR-122 associate with some aspects of AWS clinics and may dynamically reflect AWS severity.

Effects of heroin self-administration and forced withdrawal on the expression of genes related to the mTOR network in the basolateral complex of the amygdala of male Lewis rats.

RATIONALE: The development of substance use disorders involves long-lasting adaptations in specific brain areas that result in an elevated risk of relapse. Some of these adaptations are regulated by the mTOR network, a signalling system that integrates extracellular and intracellular stimuli and modulates several processes related to plasticity. While the role of the mTOR network in cocaine- and alcohol-related disorders is well established, little is known about its participation in opiate use disorders. OBJECTIVES: To use a heroin self-administration and a withdrawal protocol that induce incubation of heroin-seeking in male rats and study the associated effects on the expression of several genes related to the mTOR system and, in the specific case of Rictor, its respective translated protein and phosphorylation. RESULTS: We found that heroin self-administration elicited an increase in the expression of the genes Igf1r, Igf2r, Akt2 and Gsk3a in the basolateral complex of the amygdala, which was not as evident at 30 days of withdrawal. We also found an increase in the expression of Rictor (a protein of the mTOR complex 2) after heroin self-administration compared to the saline group, which was occluded at the 30-day withdrawal period. The activation levels of Rictor, measured by the phosphorylation rate, were also reduced after heroin self-administration, an effect that seemed more apparent in the protracted withdrawal group. CONCLUSIONS: These results suggest that heroin self-administration under extended access conditions modifies the expression profile of activators and components of the mTOR complexes and show a putative irresponsive mTOR complex 2 after withdrawal from heroin use.

Elevated transferrin saturation in individuals with alcohol use disorder: Association with HFE polymorphism and alcohol withdrawal severity.

Iron loading has been consistently reported in those with alcohol use disorder (AUD), but its effect on the clinical course of the disease is not yet fully understood. Here, we conducted a cohort study to examine whether peripheral iron measures, genetic variation in HFE rs1799945 and their interaction differed between 594 inpatient participants with alcohol use disorder (AUD) undergoing detoxification and 472 healthy controls (HC). We also assessed whether HFE rs1799945 was associated with elevated peripheral iron and can serve as a predictor of withdrawal severity. AUD patients showed significantly higher serum transferrin saturation than HC. Within the AUD group, transferrin saturation significantly predicted withdrawal symptoms (CIWA-Ar) and cumulative dose of benzodiazepine treatment during the first week of detoxification, which is an indicator of withdrawal severity. HFE rs1799945 minor allele carriers showed elevated transferrin saturation compared to non-carriers, both in AUD and healthy controls. Exploratory analyses indicated that, within the AUD cohort, HFE rs1799945 predicted CIWA withdrawal scores, and this relationship was significantly mediated by transferrin saturation. We provide evidence that serum transferrin saturation predicts alcohol withdrawal severity in AUD. Moreover, our findings replicated previous studies on elevated serum transferrin saturation in AUD and an involvement of HFE rs1799945 in serum transferrin saturation levels in both AUD and healthy controls. Future studies may use transferrin saturation measures as predictors for treatment or potentially treat iron overload to ameliorate withdrawal symptoms.

Effects of CYP2C19*17 genetic polymorphisms on plasma and saliva concentrations of diazepam in patients with alcohol withdrawal syndrome.

INTRODUCTION: Diazepam is one of the most commonly prescribed tranquilizers for the therapy of alcohol withdrawal syndrome (AWS). However, diazepam therapy often turns out to be ineffective, and some patients experience dose-dependent adverse drug reactions. Previous studies have shown that the metabolism of diazepam involves the CYP2C19 isoenzyme, whose activity is highly dependent on polymorphism of the encoding gene. OBJECTIVE: The study aimed to investigate the effects of CYP2C19*17 genetic polymorphisms on plasma and saliva concentrations of diazepam as well as its impact on the efficacy and safety rates of therapy in patients with AWS. MATERIAL AND METHODS: The study was conducted on 100 Russian male patients suffering from the AWS who received diazepam injections at a dosage of 30.0 mg/day for 5 days. Genotyping was performed by real-time PCR with allele-specific hybridization. The efficacy and safety assessment was performed using psychometric scales. RESULTS: Based on the results of the study, we revealed differences in the efficacy and safety of therapy in patients with different CYP2C19 -806C>T genotypes. Therapeutic drug monitoring revealed the statistically significant difference in the levels of diazepam plasma concentration: (CC) 251.76 (214.43; 310.61) vs. (CT+TT) 89.74 (54.18; 179.13); P = 0.003, and diazepam saliva concentration: (CC) 3.86 (3.22; 5.12) vs. (CT+TT) 0.79 (0.44; 1.56); P = 0.003. CONCLUSION: Our study showed the effects of CYP2C19*17 genetic polymorphisms on the efficacy and safety rates of diazepam. Furthermore, we revealed the statistically significant differences in plasma and saliva concentration levels of diazepam in patients carrying different genotypes.

A mouse model of weight gain after nicotine withdrawal.

Smoking cessation increases body weight. The underlying mechanisms, however, have not been fully understood. We here report an establishment of a mouse model that exhibits an augmented body weight gain after nicotine withdrawal. High fat diet-fed mice were infused with nicotine for two weeks, and then with vehicle for another two weeks using osmotic minipumps. Body weight increased immediately after nicotine cessation and was significantly higher than that of mice continued on nicotine. Mice switched to vehicle consumed more food than nicotine-continued mice during the first week of cessation, while oxygen consumption was comparable. Elevated expression of orexigenic agouti-related peptide was observed in the hypothalamic appetite center. Pair-feeding experiment revealed that the accelerated weight gain after nicotine withdrawal is explained by enhanced energy intake. As a showcase of an efficacy of pharmacologic intervention, exendin-4 was administered and showed a potent suppression of energy intake and weight gain in mice withdrawn from nicotine. Our current model provides a unique platform for the investigation of the changes of energy regulation after smoking cessation.

Mice with high FGF21 serum levels had a reduced preference for morphine and an attenuated development of acute antinociceptive tolerance and physical dependence.

Because of increased opioid misuse, there is a need to identify new targets for minimizing opioid tolerance, and physical and psychological dependence. Previous studies showed that fibroblast growth factor 21 (FGF21) decreased alcohol and sweet preference in mice. In this study, FGF21-transgenic (FGF21-Tg) mice, expressing high FGF21 serum levels, and wildtype (WT) C57BL/6J littermates were treated with morphine and saline to determine if differences exist in their physiological and behavioral responses to opioids. FGF21-Tg mice displayed reduced preference for morphine in the conditioned place preference assay compared to WT littermates. Similarly, FGF21-Tg mice had an attenuation of the magnitude and rate of acute morphine antinociceptive tolerance development, and acute and chronic morphine physical dependence, but exhibited no change in chronic morphine antinociceptive tolerance. The ED50 values for morphine-induced antinociception in the 55 °C hot plate and the 55 °C warm-water tail withdrawal assays were similar in both strains of mice. Likewise, FGF21-Tg and WT littermates had comparable responses to morphine-induced respiratory depression. Overall, FGF21-Tg mice had a decrease in the development of acute analgesic tolerance, and the development of physical dependence, and morphine preference. FGF21 and its receptor have therapeutic potential for reducing opioid withdrawal symptoms and craving, and augmenting opioid therapeutics for acute pain patients to minimize tolerance development.

Chronic morphine intoxication reduces binding of HuD to BDNF long 3'-UTR, while morphine withdrawal stimulates BDNF expression in the frontal cortex of male Wistar rats.

BACKGROUND: Brain-derived neurotrophic factor (BDNF) mediates opiate dependence phenomenon. In the brain of morphine dependent animals BDNF level is controlled transcriptionally, however, post-transcriptional mechanisms of BDNF regulation in this context remain unknown. Regulation of mRNA by binding of specific proteins to the 3'-untranslated region (3'-UTR) is one of such mechanisms. Among RNA-binding proteins neuronal Hu antigen D (HuD) is the best characterized positive regulator of BDNF, however its involvement in opiate dependence remains obscure. We suggested that HuD binding to the BDNF 3'-UTR may be linked to changes in BDNF expression induced by morphine. The aim of this study was to investigate potential association of HuD with BDNF 3'-UTR in relation to BDNF expression (Exon- and 3'-UTR-specific mRNA variants and protein level) in the frontal cortex and midbrain of male Wistar rats after chronic morphine intoxication and spontaneous withdrawal in dependent animals. RESULTS: After chronic morphine intoxication but not during morphine withdrawal HuD binding to the long BDNF 3'-UTR in the frontal cortex decreased as compared with the corresponding control group, however after intoxication BDNF expression did not change. The level of BDNF Exon I as well as mature BDNF polypeptide increased in the frontal cortex upon morphine withdrawal, while no changes in HuD binding could be detected. CONCLUSION: Thus, contrary to the assumption, HuD-BDNF 3'-UTR interaction and BDNF expression in the frontal cortex differentially change in a manner dependent on the context of morphine action.

Using the CYP3A Activity Evaluation to Predict the Efficacy and Safety of Diazepam in Patients With Alcohol Withdrawal Syndrome.

BACKGROUND: Diazepam is one of the most commonly prescribed tranquilizers for the therapy of alcohol withdrawal syndrome (AWS). Despite its popularity, there is currently no precise information on the effect of genetic polymorphisms on the efficacy and safety of diazepam therapy. OBJECTIVE: The objective of our study was to study the effect of CYP3A isoenzymes activity on the efficacy and safety of diazepam in patients with AWS. METHODS: The study was conducted on 30 Russian male patients suffering from the AWS who received diazepam in injections at a dosage of 30.0 mg / day for 5 days. The efficacy and safety assessment was performed using psychometric scales and scales for assessing the severity of adverse drug reactions. RESULTS: Based on the results of the study, we revealed the differences in the efficacy of therapy in patients with different CYP3A4 C>T intron 6 (rs35599367) genotypes: (CC) -9.0 [-13.0; -5.0], (CT+TT) -13.5 [-15.0; -10.0], p = 0.014. The scores on the UKU scale, which was used to evaluate the safety of therapy, were also different: (CC) 7.5 [6.0; 11.0], (CT+TT) 11.0 [8.0; 12.0], p = 0.003. CONCLUSION: Possible relationship between the CYP3A activity, evaluated by the content of the urinary endogenous substrate of the given isoenzyme and its metabolite, the 6-beta-hydroxy cortisol (6-ß-HC) / cortisol ratio, and the efficacy of diazepam was demonstrated. This possible relationship was also supported by the genotyping results. This should be taken into consideration when prescribing this drug to such patients in order to reduce the risk of pharmacoresistance.