title: Proteoglycan and collagen expression during human air conducting system development.
abstract: The lung is formed from a bud that grows and divides in a dichotomous  way. A bud is a new growth center which is determined by  epithelial-mesenchymal interactions where proteins of the extracellular  matrix (ECM) might be involved. To understand this protein participation  during human lung development, we examined the expression and  distribution of proteoglycans in relation to the different types of  collagens during the period in which the air conducting system is  installed. Using light microscopy and immunohistochemistry we evaluate  the expression of collagens (I, III and VI) and proteoglycans (decorin,  biglycan and lumican) between 8 to 10 weeks post fertilization and 11 to  14 weeks of gestational age of human embryo lungs. We show that  decorin, lumican and all the collagen types investigated were expressed  at the epithelium-mesenchymal interface, forming a sleeve around the  bronchiolar ducts. In addition, biglycan was expressed in both the  endothelial cells and the smooth muscle of the blood vessels. Thus, the  similar distribution pattern of collagen and proteoglycans in the early  developmental stages of the human lung may be closely related to the  process of dichotomous division of the bronchial tree. This study  provides a new insight concerning the participation of collagens and  proteoglycans in the epithelial-mesenchymal interface during the period  in which the air conducting system is installed in the human fetal lung.
authors.affiliation: Department of Human Embryology, School of Medicine, Universidad de Santiago de Chile, Usach, Santiago. carlos.godoy@usach.cl
authors.forename: C
authors.initials: C
authors.lastname: Godoy-Guzmán
authors.forename: S
authors.initials: S
authors.lastname: San Martin
authors.forename: J
authors.initials: J
authors.lastname: Pereda
mesh_terms: D058578:Biglycan / Q000378:metabolism; D011508:Chondroitin Sulfate Proteoglycans / Q000378:metabolism; D003094:Collagen / Q000378:metabolism*; D058575:Decorin / Q000378:metabolism; D005260:Female; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D007150:Immunohistochemistry; D007632:Keratan Sulfate / Q000378:metabolism; D000071234:Lumican; D008168:Lung / Q000196:embryology*; D011509:Proteoglycans / Q000378:metabolism*
chemical_list: D058578:Biglycan; D011508:Chondroitin Sulfate Proteoglycans; D058575:Decorin; C000604306:LUM protein, human; D000071234:Lumican; D011509:Proteoglycans; D003094:Collagen; D007632:Keratan Sulfate