title: Laminin 2 attachment selects myofibroblasts from fetal mouse lung.
abstract: Laminins (LNs) are extracellular matrix glycoproteins that are involved in cell adhesion, proliferation, and differentiation. So far, 11 LN variants (LN1 to LN11) have been described. In the lung, at least six LN variants have been identified. However, only the role of LN1 has been characterized to any extent. In this study, we hypothesized that the LN2 variant may play a role during lung development. We identified, by RT-PCR analysis, that the alpha2-chain mRNA of LN2 is expressed during mouse lung development. LN2 adhesion assays were then performed with cells from fetal mouse lung primary cultures. Our results showed that a specific subpopulation of fetal lung cells that expressed vimentin, alpha-smooth muscle actin, and desmin attached onto LN2, whereas the cells that did not adhere to LN2 as well as the total cell population were able to adhere readily on fibronectin. Cell attachment onto LN2 was inhibited by EDTA. In addition, we demonstrated, by RT-PCR and Western analysis, that the LN2-adherent cells autoexpressed the alpha2-chain of LN2. In the late pseudoglandular period, LN2 was localized by immunohistochemistry in the basement membrane of airways and blood vessels and around mesenchymal cells. We conclude that LN2 is expressed during lung development and that a specific subpopulation of fetal lung mesenchymal cells expressing a myofibroblastic phenotype can be selected by attachment to LN2 in primary culture. These findings lead us to speculate that LN2 may play a key role in the cell biology of myofibroblasts during lung development.
authors.affiliation: Department of Pediatric Surgery, Children's Hospital Los Angeles Research Institute, University of Southern California Schools of Dentistry and Medicine, Los Angeles, CA 90033, USA.
authors.forename: G
authors.initials: G
authors.lastname: Flores-Delgado
authors.forename: P
authors.initials: P
authors.lastname: Bringas
authors.forename: D
authors.initials: D
authors.lastname: Warburton
mesh_terms: D000199:Actins / Q000096:biosynthesis; D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D002478:Cells, Cultured; D003893:Desmin / Q000096:biosynthesis; D004492:Edetic Acid / Q000494:pharmacology; D005314:Embryonic and Fetal Development; D005333:Fetus; D005347:Fibroblasts / Q000166:cytology / Q000502:physiology; D005353:Fibronectins; D018507:Gene Expression Regulation, Developmental; D014644:Genetic Variation; D007797:Laminin / Q000235:genetics* / Q000378:metabolism*; D008168:Lung / Q000166:cytology* / Q000196:embryology*; D008648:Mesoderm / Q000502:physiology; D051379:Mice; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D014158:Transcription, Genetic; D014746:Vimentin / Q000096:biosynthesis
chemical_list: D000199:Actins; D003893:Desmin; D005353:Fibronectins; D007797:Laminin; D012333:RNA, Messenger; D014746:Vimentin; D004492:Edetic Acid