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Báo cáo y học: " Lipocalin 2 is protective against E. coli pneumonia"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học 'Respiratory Research cung cấp cho các bạn kiến thức về ngành y đề tài: Lipocalin 2 is protective against E. coli pneumonia. | Wu et al. Respiratory Research 2010 11 96 http respiratory-research.eom content 11 1 96 RESPIRATORY RESEARCH RESEARCH Open Access Lipocalin 2 is protective against E. coli pneumonia Hong Wu1 Eric Santoni-Rugiu2 Elisabeth Ralfkiaer2 Bo T Porse3 Claus Moser1 Niels Hoiby1 Niels Borregaard4 and Jack B Cowland 4 Abstract Background Lipocalin 2 is a bacteriostatic protein that binds the siderophore enterobactin an iron-chelating molecule produced by Escherichia coli E. coli that is required for bacterial growth. Infection of the lungs by E. coli is rare despite a frequent exposure to this commensal bacterium. Lipocalin 2 is an effector molecule of the innate immune system and could therefore play a role in hindering growth of E. coli in the lungs. Methods Lipocalin 2 knock-out and wild type mice were infected with two strains of E. coli. The lungs were removed 48 hours post-infection and examined for lipocalin 2 and MMP9 a myeloid marker protein by immunohistochemical staining and western blotting. Bacterial numbers were assessed in the lungs of the mice at 2 and 5 days after infection and mortality of the mice was monitored over a five-day period. The effect of administering ferrichrome an iron source that cannot be bound by lipocalin 2 along with E.coli was also examined. Results Intratracheal installation of E. coli in mice resulted in strong induction of lipocalin 2 expression in bronchial epithelium and alveolar type II pneumocytes. Migration of myeloid cells to the site of infection also contributed to an increased lipocalin 2 level in the lungs. Significant higher bacterial numbers were observed in the lungs of lipocalin 2 knock-out mice on days 2 and 5 after infection with E. coli p 0.05 . In addition a higher number of E. coliwas found in the spleen of surviving lipocalin 2 knock-out mice on day 5 post-infection than in the corresponding wild-type mice p 0.05 . The protective effect against E. coli infection in wild type mice could be counteracted by the .