title: Alveolar macrophage activation in obese patients with obstructive sleep apnea.
abstract: BACKGROUND
  Classically, activated macrophages in adipose tissue, liver, and muscle have been implicated in many conditions associated with obesity, including insulin resistance and the metabolic syndrome. Despite numerous pulmonary comorbidities and the sentinel role alveolar macrophages play in innate immunity and lung homeostasis, their activation status has not been examined in these patients. Peroxisome proliferator-activated receptor-gamma (PPAR-γ) has been shown to be a negative regulator of inflammation in addition to regulating lipid and glucose metabolism. PPAR-γ is expressed constitutively in healthy alveolar macrophages and decreased on activation. We hypothesized that PPAR-γ would be downregulated in alveolar macrophages from obese patients with obstructive sleep apnea (OSA) in the absence of overt lung disease.
  
  
  METHODS
  Alveolar macrophages were obtained by bronchoalveolar lavage from obese individuals with and without OSA and healthy controls.
  
  
  RESULTS
  Data indicated that PPAR-γ functional activity was decreased by 48% in obese with OSA and 26% without OSA (P < .05). In obese patients with OSA, PPAR-γ mRNA was decreased 2-fold compared with controls (P < .05), whereas obese patients without OSA, it was not different. Regardless of OSA, alveolar macrophages of obese patients demonstrated increased interleukin-6 mRNA.
  
  
  CONCLUSIONS
  These findings are consistent with the presence of classic macrophage activation and an inflammatory lung environment. Data from this study suggest that alveolar macrophage dysfunction becomes aggravated in OSA and may increase pulmonary disease susceptibility.
authors: Program in Lung Cell Biology and Translational Research, Division of Pulmonary, Critical Care and Sleep Medicine, The Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA.
authors: Sunil
authors: S
authors: Sharma
authors: Anagha
authors: A
authors: Malur
authors: Irene
authors: I
authors: Marshall
authors: Isham
authors: I
authors: Huizar
authors: Barbara P
authors: BP
authors: Barna
authors: Walter
authors: W
authors: Pories
authors: Lynis
authors: L
authors: Dohm
authors: Mani S
authors: MS
authors: Kavuru
authors: Mary Jane
authors: MJ
authors: Thomassen
mesh_terms: D000328:Adult; D018893:Bronchoalveolar Lavage; D016022:Case-Control Studies; D002467:Cell Nucleus / Q000378:metabolism; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism; D008262:Macrophage Activation; D016676:Macrophages, Alveolar / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000276:immunology* / Q000378:metabolism; D047495:PPAR gamma / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D020181:Sleep Apnea, Obstructive / Q000276:immunology* / Q000378:metabolism; D014158:Transcription, Genetic; D055815:Young Adult
chemical_list: C508600:IL6 protein, human; D015850:Interleukin-6; D047495:PPAR gamma; D012333:RNA, Messenger