title: Dysregulation of claudin-5 in HIV-induced interstitial pneumonitis and lung vascular injury. Protective role of peroxisome proliferator-activated receptor-γ.
abstract: BACKGROUND
  HIV-1-induced interstitial pneumonitis (IP) is a serious complication of HIV-1 infection, characterized by inflammation and cellular infiltration in lungs, often leading to respiratory failure and death. The barrier function of the pulmonary endothelium is caused in part by tight junction (TJ) proteins, such as claudin-5. Peroxisome proliferator-activated receptor (PPAR)-γ is expressed in lung tissues and regulates inflammation. We hypothesize that HIV-1 induces vascular lung injury, and HIV-1-mediated damage of the pulmonary endothelium and IP is associated with dysregulation of PPAR-γ.
  
  
  OBJECTIVE
  Investigate the effects of HIV-1 infection on the pulmonary microvasculature and the modulatory effects of the PPAR-γ ligands.
  
  
  METHODS
  Using human lung tissues, we demonstrated down-regulation of claudin-5 (marker of pulmonary barrier integrity), down-regulation of PPAR-γ transcription, and expression in lung tissues of HIV-1-infected humans with IP.
  
  
  RESULTS
  Human lung microvascular endothelial cells expressed the TJ proteins claudin-5, ZO-1, and ZO-2; HIV-1 decreased TJ proteins expression and induced nuclear factor-κB promoter activity, which was reversed by PPAR-γ agonist. Using two murine HIV/AIDS models, we demonstrated decreased claudin-5 expression and increased macrophage infiltration in the lungs of HIV-1-infected animals. Activation of PPAR-γ prevented HIV-1-induced claudin-5 down-regulation and significantly reduced viremia and pulmonary macrophage infiltration.
  
  
  CONCLUSIONS
  HIV-induced IP is associated with injury to the lung vascular endothelium, with decreased TJ and PPAR-γ expression, and increased pulmonary macrophage infiltration. PPAR-γ ligands abrogated these effects. Thus, regulation of PPAR-γ can be a therapeutic approach against HIV-1-induced vascular damage and IP in infected humans. Removal of Expression of Concern: Issues leading to the previous expression of concern for this article have been resolved after further revisions and editorial review. No further concerns exist.
authors.affiliation: 1 Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska; and.
authors.forename: Hong
authors.initials: H
authors.lastname: Li
authors.forename: Sangya
authors.initials: S
authors.lastname: Singh
authors.forename: Raghava
authors.initials: R
authors.lastname: Potula
authors.forename: Yuri
authors.initials: Y
authors.lastname: Persidsky
authors.forename: Georgette D
authors.initials: GD
authors.lastname: Kanmogne
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000150:complications*; D000328:Adult; D000368:Aged; D000818:Animals; D001996:Bronchopneumonia / Q000209:etiology* / Q000276:immunology / Q000382:microbiology; D016022:Case-Control Studies; D062507:Claudin-5 / Q000276:immunology* / Q000378:metabolism; D004195:Disease Models, Animal; D015536:Down-Regulation / Q000187:drug effects / Q000276:immunology; D004730:Endothelium, Vascular / Q000276:immunology / Q000378:metabolism; D005260:Female; D015497:HIV-1 / Q000276:immunology / Q000472:pathogenicity; D006801:Humans; D016867:Immunocompromised Host / Q000276:immunology*; D008168:Lung / Q000098:blood supply / Q000276:immunology / Q000382:microbiology; D017563:Lung Diseases, Interstitial / Q000209:etiology / Q000276:immunology* / Q000382:microbiology; D008264:Macrophages / Q000276:immunology; D008297:Male; D051379:Mice; D008875:Middle Aged; D047495:PPAR gamma / Q000276:immunology* / Q000378:metabolism; D062725:Tight Junction Proteins / Q000276:immunology
chemical_list: D062507:Claudin-5; D047495:PPAR gamma; D062725:Tight Junction Proteins