Effects of repeated alcohol abstinence on within-subject prefrontal cortical gene expression in rhesus macaques

Robert Hitzemann; Lina Gao; Suzanne S Fei; Karina Ray; Katinka A Vigh-Conrad; Tamara J Phillips; Robert Searles; Rita P Cervera-Juanes; Rupak Khadka; Timothy L Carlson; Steven W Gonzales; Natali Newman; Kathleen A Grant

doi:10.3389/adar.2024.12528

Effects of repeated alcohol abstinence on within-subject prefrontal cortical gene expression in rhesus macaques

Adv Drug Alcohol Res. 2024 Apr 26:4:12528. doi: 10.3389/adar.2024.12528. eCollection 2024.

Authors

Robert Hitzemann^{1

2

3}, Lina Gao^{2

4}, Suzanne S Fei^{2

4}, Karina Ray⁴, Katinka A Vigh-Conrad⁵, Tamara J Phillips^{1

2

3}, Robert Searles^{2

6}, Rita P Cervera-Juanes⁷, Rupak Khadka⁷, Timothy L Carlson⁷, Steven W Gonzales⁷, Natali Newman⁷, Kathleen A Grant^{1

2

7}

Affiliations

¹ Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR, United States.
² Portland Alcohol Research Center, Oregon Health and Science University, Portland, OR, United States.
³ Veterans Affairs Portland Health Care System, Portland, OR, United States.
⁴ Bioinformatics and Biostatistics Core, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, OR, United States.
⁵ Division of Genetics, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, OR, United States.
⁶ Integrated Genomics Laboratory, Oregon Health and Science University, Portland, OR, United States.
⁷ Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, OR, United States.

Abstract

Male rhesus monkeys (n = 24) had a biopsy of prefrontal cortical area 46 prior to chronic ethanol self-administration (n = 17) or caloric control (n = 7). Fourteen months of daily self-administration (water vs. 4% alcohol, 22 h access/day termed "open-access") was followed by two cycles of prolonged abstinence (5 weeks) each followed by 3 months of open-access alcohol and a final abstinence followed by necropsy. At necropsy, a biopsy of Area 46, contralateral to the original biopsy, was obtained. Gene expression data (RNA-Seq) were collected comparing biopsy/necropsy samples. Monkeys were categorized by drinking status during the final post-abstinent drinking phase as light (LD), binge (BD), heavy (HD) and very heavy (VHD drinkers). Comparing pre-ethanol to post-abstinent biopsies, four animals that converted from HD to VHD status had significant ontology enrichments in downregulated genes (necropsy minus biopsy n = 286) that included immune response (FDR < 9 × 10^-7) and plasma membrane changes (FDR < 1 × 10^-7). Genes in the immune response category included IL16 and 18, CCR1, B2M, TLR3, 6 and 7, SP2 and CX3CR1. Upregulated genes (N = 388) were particularly enriched in genes associated with the negative regulation of MAP kinase activity (FDR < 3 × 10^-5), including DUSP 1, 4, 5, 6 and 18, SPRY 2, 3, and 4, SPRED2, BMP4 and RGS2. Overall, these data illustrate the power of the NHP model and the within-subject design of genomic changes due to alcohol and suggest new targets for treating severe escalated drinking following repeated alcohol abstinence attempts.

Keywords: RNA-seq; abstinence from alcohol; ethanol; prefrontal cortex; rhesus macaque.

Grants and funding

The Portland Alcohol Research Center, supported by NIH/NIAAA grant P60 AA010760, provided the majority of the funds for this research. Short read sequencing assays were performed by the OHSU Massively Parallel Sequencing Shared Resource. Bioinformatics support was provided by the Oregon National Primate Research Center Bioinformatics and Biostatistics Core, which is funded in part by NIH grant P51 OD011092. Additional support was received from AA 013484 (RH) and AA017134 (KG) and AA 013510 (KG), as well as the VA Research Career Scientist program, 15F-RCS-009 (TP).