Nuclear transcriptional changes in hypothalamus of Pomc enhancer knockout mice after excessive alcohol drinking

Persistent alterations of proopiomelanocortin (Pomc) and mu‐opioid receptor (Oprm1) activity and stress responses after alcohol are critically involved in vulnerability to alcohol dependency. Gene transcriptional regulation altered by alcohol may play important roles. Mice with genome‐wide deletion of neuronal Pomc enhancer1 (nPE1−/−), had hypothalamic‐specific partial reductions of beta‐endorphin and displayed lower alcohol consumption, compared to wildtype littermates (nPE1+/+). We used RNA‐Seq to measure steady‐state nuclear mRNA transcripts of opioid and stress genes in hypothalamus of nPE1+/+ and nPE1−/− mice after 1‐day acute withdrawal from chronic excessive alcohol drinking or after water. nPE1−/− had lower basal Pomc and Pdyn (prodynorphin) levels compared to nPE1+/+, coupled with increased basal Oprm1 and Oprk1 (kappa‐opioid receptor) levels, and low alcohol drinking increased Pomc and Pdyn to the basal levels of nPE1+/+ in the water group, without significant effects on Oprm1 and Oprk1. In nPE1+/+, excessive alcohol intake increased Pomc and Oprm1, with no effect on Pdyn or Oprk1. For stress genes, nPE1−/− had lowered basal Oxt (oxytocin) and Avp (arginine vasopressin) that were restored by low alcohol intake to basal levels of nPE1+/+. In nPE1+/+, excessive alcohol intake decreased Oxt and Avpi1 (AVP‐induced protein1). Functionally examining the effect of pharmacological blockade of mu‐opioid receptor, we found that naltrexone reduced excessive alcohol intake in nPE1+/+, but not nPE1−/−. Our results provide evidence relevant to the transcriptional profiling of the critical genes in mouse hypothalamus: enhanced opioid and reduced stress gene transcripts after acute withdrawal from excessive alcohol may contribute to altered reward and stress responses.Transcriptional profiling of the critical genes in mouse hypothalamus: enhanced opioid and reduced stress gene transcripts after acute withdrawal from excessive alcohol may contribute to altered reward and stress responses.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152013/1/gbb12600.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/152013/2/gbb12600_am.pd

V1b Receptor Antagonist SSR149415 and Naltrexone Synergistically Decrease Excessive Alcohol Drinking in Male and Female Mice

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141424/1/acer13544.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/141424/2/acer13544_am.pd

LC-MS/MS quantification of salvinorin A from biological fluids

A facile method for quantifying the concentration of the powerful and widely available hallucinogen salvinorin A (a selective kappa opioid agonist) from non-human primate cerebrospinal fluid (CSF) and human plasma has been developed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in positive electrospray ionization (ESI) mode. With CSF solid phase extraction can be avoided completely by simply diluting each sample to 10 % (v/v) acetonitrile, 1 % (v/v) formic acid and injecting under high aqueous conditions for analyte focusing. Extensive plasma sample preparation was investigated including protein precipitation, SPE column selection, and plasma particulate removal. Human plasma samples were centrifuged at 21,000 × gravity for 4 minutes to obtain clear particulate-free plasma, from which 300 μl was spiked with internal standard and loaded onto a C18 SPE column with a 100 mg mL−1 loading capacity. Guard columns (C18, hand packed 1 mm × 20 mm) were exchanged after backpressure increased above 4600psi, about 250 injections. A shallow acetonitrile/water gradient was used, 29 to 33% CH3CN over 8 minutes to elute salvinorin A. Reduction of chemical noise was achieved using tandem mass spectrometry with multiple reaction monitoring while sensitivity increases were observed using a 50 μL injection volume onto a small bore analytical column (C18, 1 mm ID × 50 mm) thus increasing peak concentration. Limits of quantification were found to be 0.0125 ng mL−1 (CSF) and 0.05 ng mL−1 (plasma) with interday precision and accuracy below 1.7 % and 9.42 % (CSF) and 3.47 % and 12.37 % (plasma) respectively. This method was used to determine the concentration of salvinorin A from an in vivo Rhesus monkey study and a trial of healthy human research participants, using behaviorally active doses

Opioid receptors in GtoPdb v.2023.1

Opioid and opioid-like receptors are activated by a variety of endogenous peptides including [Met]enkephalin (met), [Leu]enkephalin (leu), β-endorphin (β-end), α-neodynorphin, dynorphin A (dynA), dynorphin B (dynB), big dynorphin (Big dyn), nociceptin/orphanin FQ (N/OFQ); endomorphin-1 and endomorphin-2 are also potential endogenous peptides. The Greek letter nomenclature for the opioid receptors, μ, δ and κ, is well established, and NC-IUPHAR considers this nomenclature appropriate, along with the symbols spelled out (mu, delta, and kappa), and the acronyms, MOP, DOP, and KOP [124, 101, 92]. However the acronyms MOR, DOR and KOR are still widely used in the literature. The human N/OFQ receptor, NOP, is considered 'opioid-related' rather than opioid because, while it exhibits a high degree of structural homology with the conventional opioid receptors [304], it displays a distinct pharmacology. Currently there are numerous clinically used drugs, such as morphine and many other opioid analgesics, as well as antagonists such as naloxone. The majority of clinically used opiates are relatively selective μ agonists or partial agonists, though there are some μ/κ compounds, such as butorphanol, in clinical use. κ opioid agonists, such as the alkaloid nalfurafine and the peripherally acting peptide difelikefalin, are in clinical use for itch

Opioid receptors in GtoPdb v.2021.3

Opioid and opioid-like receptors are activated by a variety of endogenous peptides including [Met]enkephalin (met), [Leu]enkephalin (leu), β-endorphin (β-end), α-neodynorphin, dynorphin A (dynA), dynorphin B (dynB), big dynorphin (Big dyn), nociceptin/orphanin FQ (N/OFQ); endomorphin-1 and endomorphin-2 are also potential endogenous peptides. The Greek letter nomenclature for the opioid receptors, μ, δ and κ, is well established, and NC-IUPHAR considers this nomenclature appropriate, along with the symbols spelled out (mu, delta, and kappa), and the acronyms, MOP, DOP, and KOP. [121, 100, 91]. The human N/OFQ receptor, NOP, is considered 'opioid-related' rather than opioid because, while it exhibits a high degree of structural homology with the conventional opioid receptors [294], it displays a distinct pharmacology. Currently there are numerous clinically used drugs, such as morphine and many other opioid analgesics, as well as antagonists such as naloxone, however only for the μ receptor

Opioid receptors (version 2019.4) in the IUPHAR/BPS Guide to Pharmacology Database

Opioid and opioid-like receptors are activated by a variety of endogenous peptides including [Met]enkephalin (met), [Leu]enkephalin (leu), β-endorphin (β-end), α-neodynorphin, dynorphin A (dynA), dynorphin B (dynB), big dynorphin (Big dyn), nociceptin/orphanin FQ (N/OFQ); endomorphin-1 and endomorphin-2 are also potential endogenous peptides. The Greek letter nomenclature for the opioid receptors, μ, δ and κ, is well established, and NC-IUPHAR considers this nomenclature appropriate, along with the symbols spelled out (mu, delta, and kappa), and the acronyms, MOP, DOP, and KOP. [116, 96, 88]. The human N/OFQ receptor, NOP, is considered 'opioid-related' rather than opioid because, while it exhibits a high degree of structural homology with the conventional opioid receptors [282], it displays a distinct pharmacology. Currently there are numerous clinically used drugs, such as morphine and many other opioid analgesics, as well as antagonists such as naloxone, however only for the μ receptor

Association of the OPRM1 Variant rs1799971 (A118G) with Non-Specific Liability to Substance Dependence in a Collaborative de novo Meta-Analysis of European-Ancestry Cohorts

Peer reviewe

Hypothalamic-specific proopiomelanocortin deficiency reduces alcohol drinking in male and female mice

Opioid receptor antagonist naltrexone reduces alcohol consumption and relapse in both humans and rodents. This study investigated whether hypothalamic proopiomelanocortin (POMC) neurons (producing beta-endorphin and melanocortins) play a role in alcohol drinking behaviors. Both male and female mice with targeted deletion of two neuronal Pomc enhancers nPE1 and nPE2 (nPE−/−), resulting in hypothalamic-specific POMC deficiency, were studied in short-access (4-h/day) drinking-in-the-dark (DID, alcohol in one bottle, intermittent access (IA, 24-h cycles of alcohol access every other day, alcohol vs. water in a two-bottle choice) and alcohol deprivation effect (ADE) models. Wild-type nPE+/+ exposed to 1-week DID rapidly established stable alcohol drinking behavior with more intake in females, whereas nPE−/− mice of both sexes had less intake and less preference. Although nPE−/− showed less saccharin intake and preference than nPE+/+, there was no genotype difference in sucrose intake or preference in the DID paradigm. After 3-week IA, nPE+/+ gradually escalated to high alcohol intake and preference, with more intake in females, whereas nPE−/− showed less escalation. Pharmacological blockade of mu-opioid receptors with naltrexone reduced intake in nPE+/+ in a dose-dependent manner, but had blunted effects in nPE−/− of both sexes. When alcohol was presented again after 1-week abstinence from IA, nPE+/+ of both sexes displayed significant increases in alcohol intake (ADE or relapse-like drinking), with more pronounced ADE in females, whereas nPE−/− did not show ADE in either sex. Our results suggest that neuronal POMC is involved in modulation of alcohol ‘binge’ drinking, escalation and ‘relapse’, probably via hypothalamic-mediated mechanisms, with sex differences.Fil: Zhou, Yan. The Rockefeller University; Estados UnidosFil: Rubinstein, Marcelo. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Low, Malcolm J.. University of Michigan; Estados UnidosFil: Kreek, Mary Jeanne. The Rockefeller University; Estados Unido

Oxycodone Self-Administration Induces Alterations in Expression of Integrin, Semaphorin and Ephrin Genes in the Mouse Striatum

Oxycodone is one a commonly used medication for pain, and is also a widely abused prescription opioid, like other short-acting MOPr agonists. Neurochemical and structural adaptations in brain following chronic MOPr-agonist administration are thought to underlie pathogenesis and persistence of opiate addiction. Many axon guidance molecules, such as integrins, semaphorins, and ephrins may contribute to oxycodone-induced neuroadaptations through alterations in axon-target connections and synaptogenesis, that may be implicated in the behaviors associated with opiate addiction. However, little is known about this important area. The aim of this study is to investigate alterations in expression of selected integrin, semaphorin, ephrins, netrin, and slit genes in the nucleus accumbens (NAc) and caudate putamen (CPu) of mice following extended 14-day oxycodone self-administration (SA), using RNAseq.Methods: Total RNA from the NAc and CPu were isolated from adult male C57BL/6J mice within 1 h after the last session of oxycodone in a 14-day self-administration paradigm (4h/day, 0.25 mg/kg/infusion, FR1) or from yoked saline controls. Gene expressions were examined using RNA sequencing (RNA-Seq) technology. RNA-Seq libraries were prepared using Illumina's TruSeq® Stranded Total RNA LT kit. The reads were aligned to the mouse reference genome (version mm10) using STAR. DESeq2 was applied to the counts of protein coding genes to estimate the fold change between the treatment groups. False Discovery Rate (FDR) q < 0.1 were used to select genes that have a significant expression change. For selection of a subset of genes related to axon guidance pathway, REACTOME was used.Results: Among 38 known genes of the integrin, semaphorin, and ephrin gene families, RNA-seq data revealed up-regulation of six genes in the NAc: heterodimer receptor, integrins Itgal, Itgb2, and Itgam, and its ligand semaphorin Sema7a, two semaphorin receptors, plexins Plxnd1 and Plxdc1. There was down-regulation of eight genes in this region: two integrin genes Itga3 and Itgb8, semaphorins Sema3c, Sema4g, Sema6a, Sema6d, semaphorin receptor neuropilin Nrp2, and ephrin receptor Epha3. In the CPu, there were five differentially expressed axon guidance genes: up-regulation of three integrin genes, Itgal, Itgb2, Itga1, and down-regulation of Itga9 and ephrin Efna3 were thus observed. No significant alterations in expression of Netrin-1 or Slit were observed.Conclusion: We provide evidence for alterations in the expression of selective axon guidance genes in adult mouse brain following chronic self-administration of oxycodone. Further examination of oxycodone-induced changes in the expression of these specific axon guidance molecules and integrin genes in relation to behavior may provide new insights into development of addiction to oxycodone