title: Up-Regulation of PKR Signaling Pathway by Ethanol Displays an Age of Onset-Dependent Relationship.
abstract: Ethanol (EtOH) neurotoxicity can result in devastating effects on brain and behavior by disrupting homeostatic signaling cascades and inducing cell death. One such mechanism involves double-stranded RNA activated protein kinase (PKR), a primary regulator of protein translation and cell viability in the presence of a virus or other external stimuli. EtOH-mediated up-regulation of interferon-gamma (IFN-γ; the oxidative stress-inducible regulator of PKR), PKR, and its target, p53, are still being fully elucidated.
  
  
  
  Using Western blot analysis, immunofluorescence, and linear regression analyses, changes in the IFN-γ-PKR-p53 pathway following chronic EtOH treatment in the frontal cortex of rodents were examined. The role of PKR on cell viability was also assessed in EtOH-treated cells using PKR overexpression vector and PKR inhibitor (PKRI).
  
  
  
  In rats chronically fed EtOH, PKR, phosphorylated PKR (p-PKR), IFN-γ, and p53 were significantly increased following chronic EtOH exposure. Linear regression revealed a significant correlation between IFN-γ and p-PKR protein levels, as well as p-PKR expression and age of EtOH exposure. Overexpression of PKR resulted in greater cell death, while use of PKRI enhanced cell viability in EtOH-treated cells.
  
  
  
  Chronic EtOH exposure activates the IFN-γ-PKR-p53 pathway in the frontal cortex of rodents. p-PKR expression is greater in brains of rodents exposed to EtOH at earlier ages compared to later life, suggesting a mechanism by which young brains could be more susceptible to EtOH-related brain injury. PKR and p-PKR were also colocalized in neurons and astrocytes of rats. This study provides additional insight into biochemical mechanisms underlying alcohol use disorder related neuropathology and warrants further investigation of PKR as a potential pharmacotherapeutic target to combat EtOH-related neurotoxicity, loss of protein translation and brain injury.
authors.affiliation: Program in Neuroscience , University of Mississippi Medical Center, Jackson, Mississippi.|Department of Psychiatry and Human Behavior , University of Mississippi Medical Center, Jackson, Mississippi.
authors.forename: Jeremy W
authors.initials: JW
authors.lastname: Duncan
authors.affiliation: Department of Psychiatry and Human Behavior , University of Mississippi Medical Center, Jackson, Mississippi.
authors.forename: Shakevia
authors.initials: S
authors.lastname: Johnson
authors.affiliation: Program in Neuroscience , University of Mississippi Medical Center, Jackson, Mississippi.|Department of Psychiatry and Human Behavior , University of Mississippi Medical Center, Jackson, Mississippi.
authors.forename: Xiao
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Pathology, University of Mississippi Medical Center, Jackson, Mississippi.
authors.forename: Baoying
authors.initials: B
authors.lastname: Zheng
authors.affiliation: Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, Kentucky.|Department of Internal Medicine, University of Kentucky, Lexington, Kentucky.
authors.forename: Jia
authors.initials: J
authors.lastname: Luo
authors.affiliation: Department of Psychiatry and Human Behavior , University of Mississippi Medical Center, Jackson, Mississippi.
authors.forename: Xiao-Ming
authors.initials: XM
authors.lastname: Ou
authors.affiliation: Department of Psychiatry and Human Behavior , University of Mississippi Medical Center, Jackson, Mississippi.
authors.forename: Craig A
authors.initials: CA
authors.lastname: Stockmeier
authors.affiliation: Program in Neuroscience , University of Mississippi Medical Center, Jackson, Mississippi. jwang@umc.edu.|Department of Psychiatry and Human Behavior , University of Mississippi Medical Center, Jackson, Mississippi. jwang@umc.edu.|Department of Pathology, University of Mississippi Medical Center, Jackson, Mississippi. jwang@umc.edu.
authors.forename: Jun Ming
authors.initials: JM
authors.lastname: Wang
mesh_terms: D017668:Age of Onset; D000818:Animals; D016923:Cell Death / Q000187:drug effects; D045744:Cell Line, Tumor; D002492:Central Nervous System Depressants / Q000494:pharmacology*; D000431:Ethanol / Q000494:pharmacology*; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism*; D008297:Male; D017397:Prefrontal Cortex / Q000187:drug effects* / Q000378:metabolism; D011897:Random Allocation; D017208:Rats, Wistar; D015398:Signal Transduction / Q000187:drug effects; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D015854:Up-Regulation / Q000187:drug effects; D019892:eIF-2 Kinase / Q000378:metabolism*
chemical_list: D002492:Central Nervous System Depressants; D016159:Tumor Suppressor Protein p53; D000431:Ethanol; D007371:Interferon-gamma; D019892:eIF-2 Kinase
keywords: Double-Stranded RNA Activated Protein Kinase; Ethanol-Induced Cell Death and Age; IFNγ-PKR-p53 Pathway and Age; Interferon-Gamma; p53