Premium
Chronic alcohol ingestion induces alveolar macrophage oxidative stress and phagocytic dysfunction by down‐regulating NADPH oxidase‐related microRNAs
Author(s) -
Yeligar Samantha M.,
Harris Frank L.,
Hart C. Michael,
Brown Lou Ann S.
Publication year - 2016
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.30.1_supplement.743.5
Subject(s) - nox1 , nox4 , oxidative stress , nadph oxidase , chemistry , microbiology and biotechnology , respiratory burst , biology , biochemistry
Objective Compared to non‐alcoholics, chronic alcohol abusers are 2–4 times as likely to develop respiratory infections and acute respiratory distress syndrome (ARDS). Alcohol abuse increases susceptibility to lung infections in alcoholics through enhanced oxidative stress and impaired alveolar macrophage (AM) phagocytic function. NADPH oxidases (Nox) are primary sources of oxidative stress in AMs, and the Nox isoforms, Nox1 and Nox2, are required for Nox4 expression and activity. We hypothesize that alcohol attenuates Nox1‐ and Nox2‐associated microRNAs (miRs) to up‐regulate Nox1, Nox2, Nox4, oxidative stress, and phagocytic dysfunction. Methods AMs were obtained from the bronchoalveolar lavage (BAL) fluid of C57BL/6J mice fed ± ethanol (20% w/v) in the drinking water for 12 wks. In parallel, MH‐S cells, a mouse AM cell line, were transfected ± 50 nM miR mimics and treated ± 0.08% ethanol for 3 d. Levels of Nox1‐related miRs (miR‐1264 and ‐1982), which bind to the Nox1 3′UTR to decrease Nox1 levels, and Nox2‐related miRs (miR‐103 and ‐107), which bind to the Nox2 3′UTR to decrease Nox2 levels, were assessed by qRT‐PCR. Nox1, Nox2, and Nox4 mRNA and protein expression were measured by qRT‐PCR and western blot. Oxidative stress was measured with DCFH‐DA and Amplex Red assays. AM function was evaluated by phagocytosis assay ( S. aureus internalization). Results In vivo and in vitro studies demonstrated that ethanol: 1) decreased AM levels of Nox1‐related miR‐1264 and Nox2‐related miR‐107; 2) increased Nox1, Nox2, and Nox4 mRNA and protein expression; 3) enhanced oxidative stress; and 4) impaired phagocytic capacity. miR mimics reversed these ethanol‐induced AM derangements. Conclusions Chronic alcohol ingestion enhances AM Nox expression, oxidative stress, and phagocytic dysfunction by down‐regulating Nox‐related miRs. Our studies suggest that targeting Nox‐related miR expression may attenuate alcohol‐induced AM derangements and decrease susceptibility to respiratory infections in patients with a history of alcohol use disorders. Support or Funding Information Research Funding Source : AHA SDG 13SDG13930003 (SMY), NIAAA 1K99AA021803 (SMY), Emory Alcohol & Lung Biology Center 1P50AA135757 (LAB & CMH), and Merit Review Funding from the Atlanta VA Medical Center (CMH).