title: Type IV collagen alpha chains of the basement membrane in the rat bronchioalveolar transitional segment.
abstract: In the present study, we have analyzed the alpha(IV) chain distribution in the subepithelial basement membrane (BM) of the rat pulmonary airway from the bronchi to alveoli. We have furthermore analyzed the alpha(IV) chain distribution in the subepithelial BM of the bronchioalveolar duct junction (BADJ) using alpha(IV) chain specific monoclonal antibodies. Our results show that the BM of the bronchial and bronchiolar epithelium contains [alpha1(IV)]2alpha2(IV) and [alpha5(IV)]2alpha6(IV) molecules and confirmed that the alveolar BM consists of [alpha1(IV)]2alpha2(IV) and alpha3(IV) alpha4(IV)alpha5(IV) molecules. There are also small regions in BADJ consisting of only [alpha1(IV)]2alpha2(IV) molecules without alpha3(IV)alpha4(IV)alpha5(IV) and [alpha5(IV)]2alpha6(IV) molecules. Moreover, the bronchioalveolar stem cells (BASCs)-primordial cells for bronchiolar Clara cells and alveolar type II (AT2) cells - lie adjacent to such small regions. These findings suggest that [alpha1(IV)]2 alpha2(IV) may be important for the BASCs to self-renew or to self-maintain themselves and that microenvironments produced by alpha(IV) chains may be important for cell differentiation.
authors.affiliation: Department of Human Morphology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
authors.forename: Noriko
authors.initials: N
authors.lastname: Hinenoya
authors.forename: Ichiro
authors.initials: I
authors.lastname: Naito
authors.forename: Ryusuke
authors.initials: R
authors.lastname: Momota
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Sado
authors.forename: Kanae
authors.initials: K
authors.lastname: Kumagishi
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Ninomiya
authors.forename: Aiji
authors.initials: A
authors.lastname: Ohtsuka
mesh_terms: D000818:Animals; D001485:Basement Membrane / Q000378:metabolism*; D055745:Bronchioles / Q000378:metabolism*; D024141:Collagen Type IV / Q000032:analysis* / Q000378:metabolism; D008297:Male; D008856:Microscopy, Fluorescence; D011650:Pulmonary Alveoli / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D024141:Collagen Type IV