Association of miR-155, miR-187 and Inflammatory Cytokines IL-6, IL-10 and TNF-α in Chronic Opium Abusers

Substance use disorders are known to be associated with inflammation. However, the dynamics of inflammatory cytokines and microRNA in chronic opium use is yet unexplored. The current study determined the levels of inflammatory cytokines TNF-α, IL-6, IL-10 and immune-regulatory miR-155 and miR-187 expressions in chronic opioid use disorder. Adults (n = 48) meeting the 5th Edition of the DSM criteria regarding opioid use disorder and healthy controls (n = 46) were included in the study. Inflammatory cytokines IL-10, IL-6, and TNF-α were analyzed from serum samples, and peripheral blood mononuclear cells processed for miRNA expression. Cases showed significantly raised IL-10 and TNF-α and reduced IL-6. Dose-dependent upregulation of miR-155-5p and miR-187-5p was evident at opium dose >1500 g/month, with a corresponding increase of TNF-α and IL-10. MiR-155 showed a significant positive correlation with IL-6 and TNF-α levels, while miR-187 showed a significant negative association with TNF-α at ≥1000 g/month consumption. Therefore, increasing consumption of opium probably enhances inflammation leading to immunomodulation and aberrant expression of hsa-miR-155-5p and hsa-miR-187-5p in opioid use disorder.