The Three-Dimensional Ultrastructure of the Human Alveolar Epithelium Revealed by Focused Ion Beam Electron Microscopy

摘要: Thin type 1 alveolar epithelial (AE1) and surfactant producing 2 (AE2) cells line the alveoli in lung are essential for normal function. Function is intimately interrelated to structure, so that detailed knowledge of ultrastructure can significantly enhance our understanding its The basolateral surface or contact sites special interest, because they play an important role intercellular communication stabilizing epithelium. latter particular with variable volume. aim present study was investigate three-dimensional (3D) human epithelium focusing on cell membrane AE2 using focused ion beam electron microscopy subsequent 3D reconstructions. provides reconstructions two AE1 domains cells, showing AE1/AE1, AE1/AE2 AE2/AE2 sites, microvilli pits at small processes beneath cells. Furthermore, we show a secretion pore, enlargements apical long folds bordering grooves basal surface. functional implications findings discussed. These may lay structural basis further molecular investigations.