title: TLR2 and TLR4 Expression and Inflammatory Cytokines are Altered in the Airway Epithelium of Those with Alcohol Use Disorders.
abstract: BACKGROUND
  The lung has a highly regulated system of innate immunity to protect itself from inhaled microbes and toxins. The first line of defense is mucociliary clearance, but if invaders overcome this, inflammatory pathways are activated. Toll-like receptors (TLRs) are expressed on the airway epithelium. Their signaling initiates the inflammatory cascade and leads to production of inflammatory cytokines such as interleukin (IL)-6 and IL-8. We hypothesized that airway epithelial insults, including heavy alcohol intake or smoking, would alter the expression of TLRs on the airway epithelium.
  
  
  METHODS
  Bronchoscopy with bronchoalveolar lavage and brushings of the airway epithelium was performed in otherwise healthy subjects who had normal chest radiographs and spirometry. A history of alcohol use disorders (AUDs) was ascertained using the Alcohol Use Disorders Identification Test (AUDIT), and a history of cigarette smoking was also obtained. Age, gender, and nutritional status in all groups were similar. We used real-time polymerase chain reaction (PCR) to quantitate TLR1 to 9 and enzyme-linked immune assay to measure tumor necrosis factor-α, IL-6, and IL-8.
  
  
  RESULTS
  Airway brushings were obtained from 26 nonsmoking/non-AUD subjects, 28 smoking/non-AUD subjects, 36 smoking/AUD subjects, and 17 nonsmoking/AUD subjects. We found that TLR2 is up-regulated in AUD subjects, compared to nonsmoking/non-AUD subjects, and correlated with their AUDIT scores. We also measured a decrease in TLR4 expression in AUD subjects that correlated with AUDIT score. IL-6 and IL-8 were also increased in bronchial washings from AUD subjects.
  
  
  CONCLUSIONS
  We have previously demonstrated in normal human bronchial epithelial cells that in vitro alcohol exposure up-regulates TLR2 through a NO/cGMP/PKG-dependent pathway, resulting in up-regulation of inflammatory cytokine production after Gram-positive bacterial product stimulation. Our current translational study confirms that TLR2 is also up-regulated in humans with AUDs.
authors.affiliation: Internal Medicine, Division of Pulmonary, Critical Care, Sleep and Allergy, University of Nebraska Medical Center, Omaha, Nebraska.|Veterans Affairs Nebraska-Western Iowa Health Care System, Research Service, Omaha, Nebraska.
authors.forename: Kristina L
authors.initials: KL
authors.lastname: Bailey
authors.affiliation: Internal Medicine, Division of Pulmonary, Critical Care, Sleep and Allergy, University of Nebraska Medical Center, Omaha, Nebraska.|Veterans Affairs Nebraska-Western Iowa Health Care System, Research Service, Omaha, Nebraska.
authors.forename: Debra J
authors.initials: DJ
authors.lastname: Romberger
authors.affiliation: Internal Medicine, Division of Pulmonary, Critical Care, Sleep and Allergy, University of Nebraska Medical Center, Omaha, Nebraska.
authors.forename: Dawn M
authors.initials: DM
authors.lastname: Katafiasz
authors.affiliation: Internal Medicine, Division of Pulmonary, Critical Care, Sleep and Allergy, University of Nebraska Medical Center, Omaha, Nebraska.|Veterans Affairs Nebraska-Western Iowa Health Care System, Research Service, Omaha, Nebraska.
authors.forename: Art J
authors.initials: AJ
authors.lastname: Heires
authors.affiliation: Internal Medicine, Division of Pulmonary, Critical Care, Sleep and Allergy, University of Nebraska Medical Center, Omaha, Nebraska.
authors.forename: Joseph H
authors.initials: JH
authors.lastname: Sisson
authors.affiliation: Internal Medicine, Division of Pulmonary, Critical Care, Sleep and Allergy, University of Nebraska Medical Center, Omaha, Nebraska.|Veterans Affairs Nebraska-Western Iowa Health Care System, Research Service, Omaha, Nebraska.|Department of Environmental, Agricultural & Occupational Health, College of Public Health, University of Nebraska Medical Center, Omaha, Nebraska.
authors.forename: Todd A
authors.initials: TA
authors.lastname: Wyatt
authors.affiliation: University of Colorado School of Medicine, Denver, Colorado.
authors.forename: Ellen L
authors.initials: EL
authors.lastname: Burnham
mesh_terms: D000328:Adult; D019973:Alcohol-Related Disorders / Q000175:diagnosis / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D015331:Cohort Studies; D016207:Cytokines / Q000096:biosynthesis* / Q000235:genetics; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D020545:Respiratory Mucosa / Q000378:metabolism* / Q000473:pathology; D051195:Toll-Like Receptor 2 / Q000096:biosynthesis* / Q000235:genetics; D051197:Toll-Like Receptor 4 / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D016207:Cytokines; D018836:Inflammation Mediators; C495342:TLR2 protein, human; C495345:TLR4 protein, human; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4
keywords: Airway Epithelium; Cytokines; Human; Toll-Like Receptors