title: Lectin-like oxidized low-density lipoprotein receptor-1 modulates endothelial apoptosis in obstructive sleep apnea.
abstract: BACKGROUND
  Lectin-like oxidized low-density lipoprotein receptor 1 (LOX-1) is the major receptor for oxidized low-density lipoprotein in endothelial cells, and its expression is enhanced in proatherogenic settings. The objective of this study was to investigate the association between LOX-1 in freshly harvested human venous endothelial cells and apoptotic circulating endothelial cells in patients with obstructive sleep apnea (OSA).
  
  
  METHODS
  We conducted a prospective, interventional study of 38 patients with newly diagnosed OSA free of disease and 12 healthy control subjects. Plasma LOX-1 (pLOX-1) levels were measured using a commercially available enzyme-linked immunosorbent assay. Protein expression of LOX-1 was quantified by immunofluorescence in freshly harvested venous endothelial cells before and after 8 weeks of continuous positive airway pressure (CPAP) therapy. Circulating apoptotic endothelial cells (CD146(+), CD45(-), and CD31(1)) were assessed concomitantly by flow cytometry.
  
  
  RESULTS
  pLOX-1 levels were higher in subjects with OSA than in control subjects (326.9 ± 267.1 pg/mL and 141.1 ± 138.6 g/mL, respectively; P = .004). Patients with OSA showed a threefold increase in baseline endothelial expression of LOX-1 relative to control subjects. CPAP therapy resulted in a significant decrease in endothelial LOX-1 expression only in CPAP-adherent patients. Circulating apoptotic endothelial cells correlated directly with baseline expression of LOX-1 (R(2) = 0.32, P = .01) after adjustment for age, BMI, and waist to hip ratio.
  
  
  CONCLUSIONS
  Increased expression of LOX-1 in vivo is associated with endothelial apoptosis. Adherence to CPAP therapy may reverse these derangements.
authors.affiliation: Veterans Affairs Western New York Healthcare System, Western New York Respiratory Research Center; Division of Pulmonary, Critical Care, and Sleep Medicine, University at Buffalo School of Medicine and Biomedical Sciences, Buffalo, NY.
authors.forename: Morohunfolu E
authors.initials: ME
authors.lastname: Akinnusi
authors.affiliation: Veterans Affairs Western New York Healthcare System, Western New York Respiratory Research Center.
authors.forename: Rachel
authors.initials: R
authors.lastname: Laporta
authors.affiliation: Veterans Affairs Western New York Healthcare System, Western New York Respiratory Research Center; Division of Pulmonary, Critical Care, and Sleep Medicine, University at Buffalo School of Medicine and Biomedical Sciences, Buffalo, NY; Department of Medicine, and the Department of Social and Preventive Medicine, University at Buffalo School of Medicine and Biomedical Sciences, Buffalo, NY. Electronic address: solh@buffalo.edu.
authors.forename: Ali A
authors.initials: AA
authors.lastname: El-Solh
mesh_terms: D000328:Adult; D017209:Apoptosis / Q000502:physiology; D015415:Biomarkers / Q000378:metabolism; D016022:Case-Control Studies; D002478:Cells, Cultured; D045422:Continuous Positive Airway Pressure / Q000379:methods*; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D017286:Polysomnography / Q000379:methods; D011446:Prospective Studies; D012016:Reference Values; D051127:Scavenger Receptors, Class E / Q000378:metabolism*; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000097:blood* / Q000175:diagnosis / Q000628:therapy*
chemical_list: D015415:Biomarkers; D051127:Scavenger Receptors, Class E