Idiopathic pulmonary fibrosis: misunderstandings between epithelial cells and fibroblasts?
Idiopathic pulmonary fibrosis is a complex disease of unknown etiology which produces a progressive and irreversible destruction of the alveolar-capillary units leading ultimately to death from respiratory failure. For a long time the pathogenesis of the disease was attributed to an unresolved chronic alveolitis. However, a growing body of evidence suggests that inflammation does not play a major role in this disease, and that the pivotal pathogenic mechanisms include epithelial cell microinjuries/activation, and fibroblast migration, proliferation, and differentiation in myofibroblasts forming discrete foci in the injured areas. Active fibroblasts/myofibroblasts from these foci may in turn disturb alveolar re-epithelialization, by provoking basement membrane disruption and epithelial cell apoptosis finally resulting in exaggerated extracellular matrix accumulation. This aberrant repair process annihilates the lung architecture leading to the honeycomb remodeling.
Selman
Moisés
M
Instituto Nacional de Enfermedades Respiratorias, Tlalpan 4502, CP 14080, México DF, México. moiselman@salud.gob.mx
Pardo
Annie
A
D017209:Apoptosis; D002454:Cell Differentiation; D002465:Cell Movement; D049109:Cell Proliferation; D004847:Epithelial Cells / Q000502:physiology*; D005347:Fibroblasts / Q000502:physiology*; D006801:Humans; D011658:Pulmonary Fibrosis / Q000503:physiopathology*