tailieunhanh - Báo cáo y học: " Alveolar epithelial type II cell: defender of the alveolus revisited"

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:" Alveolar epithelial type II cell: defender of the alveolus revisited. | Available online http content 2 1 033 Review Alveolar epithelial type II cell defender of the alveolus revisited Heinz Fehrenbach Institute of Pathology University Clinics Carl Gustav Carus Technical University of Dresden Germany Correspondence Heinz Fehrenbach PhD Institute of Pathology University Clinic Carl Gustav Carus TU Dresden Fetscherstr. 74 D-01307 Dresden Germany. Tel 49 351 458 5277 fax 49 351 458 4328 e-mail hefeh@ Received 27 October 2000 Revisions requested 21 November 2000 Revisions received 5 December 2000 Accepted 6 December 2000 Published 15 January 2001 Respir Res 2001 2 33-46 2001 BioMed Central Ltd Print ISSN 1465-9921 Online ISSN 1465-993X Abstract In 1977 Mason and Williams developed the concept of the alveolar epithelial type II AE2 cell as a defender of the alveolus. It is well known that AE2 cells synthesise secrete and recycle all components of the surfactant that regulates alveolar surface tension in mammalian lungs. AE2 cells influence extracellular surfactant transformation by regulating for example pH and Ca2 of the hypophase. AE2 cells play various roles in alveolar fluid balance coagulation fibrinolysis and host defence. AE2 cells proliferate differentiate into AE1 cells and remove apoptotic AE2 cells by phagocytosis thus contributing to epithelial repair. AE2 cells may act as immunoregulatory cells. AE2 cells interact with resident and mobile cells either directly by membrane contact or indirectly via cytokines growth factors and their receptors thus representing an integrative unit within the alveolus. Although most data support the concept the controversy about the character of hyperplastic AE2 cells reported to synthesise profibrotic factors proscribes drawing a definite conclusion today. Keywords alveolar epithelium apoptosis cell-cell interactions repair surfactant Introduction As early as 1954 CC Macklin had postulated some of the most important functions of the great pneumocyte .