title: Inhaled NO contributes to lung repair in piglets with acute respiratory distress syndrome via increasing circulating endothelial progenitor cells.
abstract: BACKGROUND
  Nitric oxide (NO) plays an important role in mobilization of endothelial progenitor cells (EPCs). We hypothesized that inhaled NO (iNO) would induce EPC mobilization and therefore promote lung repair in acute respiratory distress syndrome (ARDS).
  
  
  RESULTS
  Healthy piglets were randomized into four groups (n = 6): Control (Con; mechanical ventilation only); ARDS (established by oleic acid infusion and mechanical ventilation); ARDS plus granulocyte-colony stimulating factor (G-CSF; 10 µg/kg/d subcutaneously); ARDS plus NO inhalation (iNO; 10 ppm). EPCs and mobilizing cytokines were assayed at different time points (baseline, 0, 24, 72 and 168 h) and injury reparation was assessed at 168 h. Compared to the Con group, the levels of EPCs were increased in bone marrow but not in blood in the ARDS group at 24 h. Compared to the ARDS group, inhaled NO induced a rapid elevation in the number of CD34(+)KDR(+), KDR(+)CD133(+) and CD34(+)KDR(+)CD133(+) EPCs in blood (2163±454 vs. 1094±416, 1302±413 vs. 429±244, 1140±494 vs. 453±273 cells/ml, respectively, P<0.05), and a reduction in the percentage of KDR(+)CD133(+) cells in bone marrow. Lung CD34, CD133, VEGF, VEGF receptor 2, endothelial NO synthase mRNA, and VEGF and VEGF receptor 2 protein expression levels were augmented in the iNO group, but not in the G-CSF group, compared to ARDS. Furthermore, iNO treatment reduced vascular permeability, increased pulmonary vessel density, and alleviated pulmonary edema and inflammation compared to ARDS treatment. Plasma VEGF, stromal cell-derived factor-1 (SDF-1) and bone marrow NO(2)(-)/NO(3)(-) were significantly higher in the iNO group compared to the ARDS group at 72 h.
  
  
  CONCLUSIONS
  These results suggest that iNO induces mobilization of EPCs from bone marrow into circulation, contributes to vascular repair, and thereby alleviates lung damage.
authors.affiliation: Departments of Pediatrics, Children's Hospital of Fudan University, Shanghai, China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Qi
authors.forename: Liling
authors.initials: L
authors.lastname: Qian
authors.forename: Bo
authors.initials: B
authors.lastname: Sun
authors.forename: Lijuan
authors.initials: L
authors.lastname: Liu
authors.forename: Panpan
authors.initials: P
authors.lastname: Wu
authors.forename: Libo
authors.initials: L
authors.lastname: Sun
mesh_terms: D000280:Administration, Inhalation; D000818:Animals; D018952:Antigens, CD34 / Q000378:metabolism; D017209:Apoptosis; D015153:Blotting, Western; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D005434:Flow Cytometry; D007124:Immunoenzyme Techniques; D055370:Lung Injury / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D009569:Nitric Oxide / Q000008:administration & dosage*; D019301:Oleic Acid / Q000633:toxicity; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D012128:Respiratory Distress Syndrome / Q000139:chemically induced / Q000378:metabolism / Q000517:prevention & control*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013234:Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D013552:Swine
chemical_list: D018952:Antigens, CD34; D016207:Cytokines; D012333:RNA, Messenger; D019301:Oleic Acid; D009569:Nitric Oxide