Growth and differentiation factors in tracheobronchial epithelium.
The normal tracheobronchial epithelium is continuously renewing itself: cells are lost and replaced by the proliferation and differentiation of stem cells. The proliferation and differentiation of these cells have to be tightly controlled in order to maintain the normal structure of the epithelium. A variety of biological and biochemical processes are involved in controlling the proliferation and differentiation of the tracheobronchial epithelium. Since the trachea and bronchus are comprised of a heterogeneous cell population, interactions between the different cell types are of crucial importance not only in controlling the normal maintenance of this tissue but also in the regulation of repair processes following injury and morphogenesis during lung development. A variety of factors, including several polypeptide growth factors and cytokines, have been identified that regulate positively or negatively the growth and differentiation of tracheobronchial epithelial cells by autocrine or paracrine mechanisms. Retinoids are another group of regulatory factors that appear to play a crucial role in controlling cell proliferation and differentiation in the tracheobronchial epithelium. Recently, many advances have been made in understanding the action of these agents in these cells. Alterations in the balance between growth and differentiation regulatory factors appear to play an important role in several pathophysiological changes such as hyperplasia, fibrosis, and neoplasia.
Jetten
A M
AM
Cell Biology Section, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina 27709.
D000818:Animals; D001980:Bronchi / Q000166:cytology* / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D004847:Epithelial Cells; D004848:Epithelium / Q000187:drug effects; D006133:Growth Substances / Q000494:pharmacology / Q000502:physiology*; D008954:Models, Biological; D009130:Muscle, Smooth / Q000166:cytology / Q000187:drug effects; D012176:Retinoids / Q000494:pharmacology; D014132:Trachea / Q000166:cytology* / Q000187:drug effects
D006133:Growth Substances; D012176:Retinoids