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- Bazov, Igor, 1973-, et al.
(author)
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Downregulation of the neuronal opioid gene expression concomitantly with neuronal decline in dorsolateral prefrontal cortex of human alcoholics
- 2018
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In: Translational Psychiatry. - : NATURE PUBLISHING GROUP. - 2158-3188. ; 8
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Journal article (peer-reviewed)abstract
- Molecular changes in cortical areas of addicted brain may underlie cognitive impairment and loss of control over intake of addictive substances and alcohol. Prodynorphin (PDYN) gives rise to dynorphin (DYNs) opioid peptides which target kappa-opioid receptor (KOR). DYNs mediate alcohol-induced impairment of learning and memory, while KOR antagonists block excessive, compulsive-like drug and alcohol self-administration in animal models. In human brain, the DYN/KOR system may undergo adaptive changes, which along with neuronal loss, may contribute to alcohol-associated cognitive deficit. We addressed this hypothesis by comparing the expression levels and co-expression (transcriptionally coordinated) patterns of PDYN and KOR (OPRK1) genes in dorsolateral prefrontal cortex (dlPFC) between human alcoholics and controls. Postmortem brain specimens of 53 alcoholics and 55 controls were analyzed. PDYN was found to be downregulated in dlPFC of alcoholics, while OPRK1 transcription was not altered. PDYN downregulation was confined to subgroup of subjects carrying C, a high-risk allele of PDYN promoter SNP rs1997794 associated with alcoholism. Changes in PDYN expression did not depend on the decline in neuronal proportion in alcoholics, and thereby may be attributed to transcriptional adaptations in alcoholic brain. Absolute expression levels of PDYN were lower compared to those of OPRK1, suggesting that PDYN expression is a limiting factor in the DYN/KOR signaling, and that the PDYN downregulation diminishes efficacy of DYN/KOR signaling in dlPFC of human alcoholics. The overall outcome of the DYN/KOR downregulation may be disinhibition of neurotransmission, which when overactivated could contribute to formation of alcohol-related behavior.
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2. |
- Ho, Ada M-C, et al.
(author)
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Correlations between sex-related hormones, alcohol dependence and alcohol craving
- 2019
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In: Drug And Alcohol Dependence. - : Elsevier BV. - 0376-8716 .- 1879-0046. ; 197, s. 183-190
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Journal article (peer-reviewed)abstract
- Background: Sex-related differences in the susceptibility, progression, and treatment response in alcohol-dependent subjects have been repeatedly reported. In this study, we aimed to investigate the associations of the sex-related hormone/protein levels with alcohol dependence (AD) and alcohol craving in male and female subjects.Methods: Plasma sex-related hormones (estradiol, estrone, total testosterone, progesterone, follicle stimulated hormone [FSH], luteinizing hormone), and sex hormone binding globulin were measured by mass spectrometry or automated immunoassays from 44 recently-abstained subjects (29 males and 15 females; mean age = 45.9 ± 15.6) meeting DSM-IV-TR criteria for AD and 44 age-, sex- and race-matched non-AD controls. Conditional logistic regression was conducted to examine the association of sex-related hormone and protein levels with AD risk, accounting for matching variables. Their associations with alcohol craving scales (Penn Alcohol Craving Scale and Inventory of Drug-Taking Situations) were assessed in AD subjects.Results: Plasma FSH level was significantly higher in AD males (10.3 ± 9.8 IU/L) than control males (8.0 ± 15.9 IU/L; p = 0.005, pcorrected = 0.035). We also found a significant inverse correlation of FSH level with propensity to drink in negative emotional situations (Spearman’s rho=-.540; p = 0.021) and positive correlations between progesterone level and craving intensity (Spearman’s rho=.464; p = 0.020) and between total testosterone level and propensity to drink under temptations (adjusted for no-drinking days; β=6.496; p = 0.041) in AD males.Conclusions: These results suggest that FSH, progesterone, and testosterone levels may be associated with AD and alcohol craving in AD males. Future research is needed to replicate these findings and investigate the underlying biological mechanisms.
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3. |
- Karpyak, Victor M., et al.
(author)
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Association of the PDYN gene with alcohol dependence and the propensity to drink in negative emotional states
- 2013
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In: International Journal of Neuropsychopharmacology. - : Oxford University Press. - 1461-1457 .- 1469-5111. ; 16:5, s. 975-985
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Journal article (peer-reviewed)abstract
- Synthetic κ-opioid receptor (KOR) agonists induce dysphoric and pro-depressive effects and variations in the KOR (OPRK1) and prodynorphin (PDYN) genes have been shown to be associated with alcohol dependence. We genotyped 23 single nucleotide polymorphisms (SNPs) in the PDYN and OPRK1 genes in 816 alcohol-dependent subjects and investigated their association with: (1) negative craving measured by a subscale of the Inventory of Drug Taking Situations; (2) a self-reported history of depression; (3) the intensity of depressive symptoms measured by the Beck Depression Inventory-II. In addition, 13 of the 23 PDYN and OPRK1 SNPs, which were previously genotyped in a set of 1248 controls, were used to evaluate association with alcohol dependence. SNP and haplotype tests of association were performed. Analysis of a haplotype spanning the PDYN gene (rs6045784, rs910080, rs2235751, rs2281285) revealed significant association with alcohol dependence (p = 0.00079) and with negative craving (p = 0.0499). A candidate haplotype containing the PDYN rs2281285-rs1997794 SNPs that was previously associated with alcohol dependence was also associated with negative craving (p = 0.024) and alcohol dependence (p = 0.0008) in this study. A trend for association between depression severity and PDYN variation was detected. No associations of OPRK1 gene variation with alcohol dependence or other studied phenotypes were found. These findings support the hypothesis that sequence variation in the PDYN gene contributes to both alcohol dependence and the induction of negative craving in alcohol-dependent subjects.
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5. |
- Meng, Weida, et al.
(author)
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Genotype-dependent epigenetic regulation of DLGAP2 in alcohol use and dependence
- 2021
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In: Molecular Psychiatry. - : Springer Nature. - 1359-4184 .- 1476-5578. ; 26:8, s. 4367-4382
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Journal article (peer-reviewed)abstract
- Alcohol misuse is a major public health problem originating from genetic and environmental risk factors. Alterations in the brain epigenome may orchestrate changes in gene expression that lead to alcohol misuse and dependence. Through epigenome-wide association analysis of DNA methylation from human brain tissues, we identified a differentially methylated region, DMR-DLGAP2, associated with alcohol dependence. Methylation within DMR-DLGAP2 was found to be genotype-dependent, allele-specific and associated with reward processing in brain. Methylation at the DMR-DLGAP2 regulated expression of DLGAP2 in vitro, and Dlgap2-deficient mice showed reduced alcohol consumption compared with wild-type controls. These results suggest that DLGAP2 may be an interface for genetic and epigenetic factors controlling alcohol use and dependence.
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6. |
- Nosova, Olga, et al.
(author)
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Epigenetic and Transcriptional Control of the Opioid Prodynorphine Gene : In-Depth Analysis in the Human Brain
- 2021
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In: Molecules. - : MDPI. - 1431-5157 .- 1420-3049. ; 26:11
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Research review (peer-reviewed)abstract
- Neuropeptides serve as neurohormones and local paracrine regulators that control neural networks regulating behavior, endocrine system and sensorimotor functions. Their expression is characterized by exceptionally restricted profiles. Circuit-specific and adaptive expression of neuropeptide genes may be defined by transcriptional and epigenetic mechanisms controlled by cell type and subtype sequence-specific transcription factors, insulators and silencers. The opioid peptide dynorphins play a critical role in neurological and psychiatric disorders, pain processing and stress, while their mutations cause profound neurodegeneration in the human brain. In this review, we focus on the prodynorphin gene as a model for the in-depth epigenetic and transcriptional analysis of expression of the neuropeptide genes. Prodynorphin studies may provide a framework for analysis of mechanisms relevant for regulation of neuropeptide genes in normal and pathological human brain.
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7. |
- Preuss, Ulrich W., et al.
(author)
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PDYN rs2281285 Variant Association with Drinking to Avoid Emotional or Somatic Discomfort
- 2013
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In: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:11, s. e78688-
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Journal article (peer-reviewed)abstract
- Introduction: One of the proposed psychobiological pathways of craving attributes the desire for drinking in the context of tension, discomfort or unpleasant emotions, to "negative'' (or "relief'') craving. The aim of this study was to replicate a previously reported association of the PDYN rs2281285 variant with negative craving using a different phenotyping approach. Methods: The TaqMan (R) Genotyping Assay was used to genotype the rs2281285 variant in 417 German alcohol-dependent subjects. The presence of negative/relief craving was assessed by asking if participants ever ingested alcohol to avoid unwanted emotional or somatic discomfort. Results: The minor allele of rs2281285 was associated with an increased risk of drinking to avoid/escape unwanted emotional or somatic events (OR = 2.29, 95% CI = 1.08-4.85, p = 0.0298). Discussion: Despite the use of a different phenotyping approach to the measurement of negative craving, our results confirm the association between negative craving and PDYN rs2281285. Genetic markers of negative craving may help to identify subgroups of alcohol-dependent individuals vulnerable to relapse in the context of negative emotions or somatic discomfort, leading to the development of specifically tailored treatment strategies.
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8. |
- Sarkisyan, Daniil, et al.
(author)
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Downregulation of the endogenous opioid peptides in the dorsal striatum of human alcoholics
- 2015
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In: Frontiers in Cellular Neuroscience. - : Frontiers Media SA. - 1662-5102. ; 9
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Journal article (peer-reviewed)abstract
- The endogenous opioid peptides dynorphins and enkephalins may be involved in brain-area specific synaptic adaptations relevant for different stages of an addiction cycle. We compared the levels of prodynorphin (PDYN) and proenkephalin (PENK) mRNAs (by qRT-PCR), and dynorphins and enkephalins (by radioimmunoassay) in the caudate nucleus and putamen between alcoholics and control subjects. We also evaluated whether PDYN promoter variant rs1997794 associated with alcoholism affects PDYN expression. Postmortem specimens obtained from 24 alcoholics and 26 controls were included in final statistical analysis. PDYN mRNA and Met-enkephalin-Arg-Phe, a marker of PENK were downregulated in the caudate of alcoholics, while PDYN mRNA and Leu-enkephalin-Arg, a marker of PDYN were decreased in the putamen of alcoholics carrying high risk rs1997794 C allele. Downregulation of opioid peptides in the dorsal striatum may contribute to development of alcoholism including changes in goal directed behavior and formation of a compulsive habit in alcoholics.
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9. |
- Watanabe, Hiroyuki, et al.
(author)
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Asymmetry of the Endogenous Opioid System in the Human Anterior Cingulate : a Putative Molecular Basis for Lateralization of Emotions and Pain
- 2015
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In: Cerebral Cortex. - United kingdom : Oxford University Press (OUP). - 1047-3211 .- 1460-2199. ; 25:1, s. 97-108
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Journal article (peer-reviewed)abstract
- Lateralization of processing of positive and negative emotions and pain suggests an asymmetric distribution of the neurotransmitter systems regulating these functions between the left and right brain hemispheres. By virtue of their ability to selectively mediate euphoria, dysphoria and pain, the m-, d- and k-opioid receptors and their endogenous ligands may subserve these lateralized functions. We addressed this hypothesis by comparing the levels of the opioid receptors and peptides in the left and right anterior cingulate cortex (ACC), a key area for emotion and pain processing. Opioid mRNAs and peptides and five “classical” neurotransmitters were analyzed in postmortem tissues from 20 human subjects. Leu-enkephalin-Arg and Met-enkephalin-Arg-Phe, preferential d-/m- and k-/m-opioid agonists demonstrated marked lateralization to the left and right ACC, respectively. Dynorphin B strongly correlated with Leu-enkephalin-Arg in the left but not right ACC suggesting different mechanisms of conversion of this k-opioid agonist to d-/m-opioid ligand in the two hemispheres; in the right ACC dynorphin B may be cleaved by PACE4, a proprotein convertase regulating left-right asymmetry formation. These findings suggest that region-specific lateralization of neuronal networks expressing opioid peptides underlyes in part lateralization of higher functions including positive and negative emotions and pain in the human brain.
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10. |
- Winham, Stacey J., et al.
(author)
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Associations of prodynorphin sequence variation with alcohol dependence and related traits are phenotype-specific and sex-dependent
- 2015
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In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 5
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Journal article (peer-reviewed)abstract
- We previously demonstrated that prodynorphin (PDYN) haplotypes and single nucleotide polymorphism (SNP) rs2281285 are associated with alcohol dependence and the propensity to drink in negative emotional states, and recent studies suggest that PDYN gene effects on substance dependence risk may be sex-related. We examined sex-dependent associations of PDYN variation with alcohol dependence and related phenotypes, including negative craving, time until relapse after treatment and the length of sobriety episodes before seeking treatment, in discovery and validation cohorts of European ancestry. We found a significant haplotype-by-sex interaction (p = 0.03), suggesting association with alcohol dependence in males (p = 1E-4) but not females. The rs2281285G allele increased risk for alcohol dependence in males in the discovery cohort (OR = 1.49, p = 0.002), with a similar trend in the validation cohort (OR = 1.35, p = 0.086). However, rs2281285 showed a trend towards association with increased negative craving in females in both the discovery (beta = 10.16, p = 0.045) and validation samples (OR = 7.11, p = 0.066). In the discovery cohort, rs2281285 was associated with time until relapse after treatment in females (HR = 1.72, p = 0.037); in the validation cohort, it was associated with increased length of sobriety episodes before treatment in males (beta = 13.49, p = 0.001). Our findings suggest that sex-dependent effects of PDYN variants in alcohol dependence are phenotype-specific.
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