Opioid induces increased DNA damage in prefrontal cortex and nucleus accumbens

Area of Science:

• Neuroscience
• Molecular Biology
• Addiction Research

Background:

• Opioid use disorder (OUD) affects millions globally, with high relapse rates posing a significant treatment challenge.
• The precise cellular and molecular mechanisms driving relapse in OUD remain largely unknown.
• Emerging evidence links DNA damage and repair pathways to neurodegenerative diseases and substance use disorders.

Purpose of the Study:

• To investigate the relationship between DNA damage and relapse to heroin seeking in opioid use disorder.
• To examine DNA damage levels in the prefrontal cortex (PFC) and nucleus accumbens (NAc) following heroin exposure.
• To determine if manipulating DNA damage can influence heroin-seeking behavior.

Main Methods:

• Analysis of postmortem brain tissues from OUD individuals and healthy controls.
• Assessment of DNA damage in PFC and NAc of mice undergoing heroin self-administration.
• Evaluation of DNA damage persistence during abstinence and the effects of ROS scavenger N-acetylcysteine.
• Pharmacological manipulation of DNA damage using topotecan and etoposide in the PFC.

Main Results:

• Increased DNA damage observed in postmortem PFC and NAc from OUD patients.
• Elevated DNA damage found in the dorsomedial PFC (dmPFC) and NAc of mice after heroin self-administration.
• Persistent DNA damage in mouse dmPFC during abstinence, ameliorated by N-acetylcysteine, correlating with reduced heroin seeking.
• Induction of DNA breaks in the PFC during abstinence potentiated heroin-seeking behavior.

Conclusions:

• Opioid use disorder is associated with accumulated DNA damage in brain regions, particularly the PFC.
• Persistent DNA damage in the PFC may play a crucial role in opioid relapse.
• Targeting DNA damage pathways, potentially via ROS scavenging, could offer novel therapeutic strategies for OUD relapse prevention.