title: Functional Impact of Collagens on the Activity Directed by the Promoter of the α5 Integrin Subunit Gene in Corneal Epithelial Cells.
abstract: OBJECTIVE
  The early step of corneal wound healing is characterized by the massive production of fibronectin (FN), whose secretion is progressively replaced by collagens from the basal membrane as wound healing proceeds. Here, we examined whether expression of the gene encoding the α5 subunit from the FN-binding integrin α5β1 changes as corneal epithelial cells (CECs) are cultured in the presence of collagen type I (CI) or type IV (CIV).
  
  
  METHODS
  Responsiveness of the α5 gene toward collagen was determined by transfection of α5 promoter/chloramphenicol acetyltransferase (CAT) plasmids into rabbit and human CECs cultured on BSA or collagens. Electrophoretic mobility shift assays and Western blots were used to monitor the transcription factors required for basal α5 gene transcription in the presence of collagens. Gene profiling on microarrays was used to determine the impact of collagens on the patterns of genes expressed by CECs.
  
  
  RESULTS
  All collagen types repressed the full-length α5/CAT promoter activity in confluent CECs. A moderate increase was observed in subconfluent rabbit CECs grown on CIV but not on CI. These collagen-dependent regulatory influences also correlated with alterations in the transcription factors Sp1/Sp3, NFI, and AP-1 that ensure α5 gene basal transcription. Microarray analyses revealed that CI more profoundly altered the pattern of genes expressed by human CECs than CIV.
  
  
  CONCLUSIONS
  Collagens considerably suppressed α5 gene expression in CECs, suggesting that during wound healing, they may interfere with the influence FN exerts on CECs by altering their adhesive and migratory properties through a mechanism involving a reduction in α5 gene expression.
authors.affiliation: CUO-Recherche Centre de Recherche FRQS du CHU de Québec, Québec, Québec, Canada 2Médecine Régénératrice, Centre de Recherche FRQS du CHU de Québec, Québec, Québec, Canada 3Centre de Recherche en Organogénèse Expérimentale de l'Université Laval/LOEX, Québe.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Lake
authors.affiliation: CUO-Recherche Centre de Recherche FRQS du CHU de Québec, Québec, Québec, Canada 2Médecine Régénératrice, Centre de Recherche FRQS du CHU de Québec, Québec, Québec, Canada 3Centre de Recherche en Organogénèse Expérimentale de l'Université Laval/LOEX, Québe.
authors.forename: Karine
authors.initials: K
authors.lastname: Zaniolo
authors.affiliation: CUO-Recherche Centre de Recherche FRQS du CHU de Québec, Québec, Québec, Canada.
authors.forename: Marie-Ève
authors.initials: MÈ
authors.lastname: Gingras
authors.affiliation: CUO-Recherche Centre de Recherche FRQS du CHU de Québec, Québec, Québec, Canada 2Médecine Régénératrice, Centre de Recherche FRQS du CHU de Québec, Québec, Québec, Canada 3Centre de Recherche en Organogénèse Expérimentale de l'Université Laval/LOEX, Québe.
authors.forename: Camille
authors.initials: C
authors.lastname: Couture
authors.affiliation: CUO-Recherche Centre de Recherche FRQS du CHU de Québec, Québec, Québec, Canada 2Médecine Régénératrice, Centre de Recherche FRQS du CHU de Québec, Québec, Québec, Canada 3Centre de Recherche en Organogénèse Expérimentale de l'Université Laval/LOEX, Québe.
authors.forename: Christian
authors.initials: C
authors.lastname: Salesse
authors.affiliation: CUO-Recherche Centre de Recherche FRQS du CHU de Québec, Québec, Québec, Canada 2Médecine Régénératrice, Centre de Recherche FRQS du CHU de Québec, Québec, Québec, Canada 3Centre de Recherche en Organogénèse Expérimentale de l'Université Laval/LOEX, Québe.
authors.forename: Sylvain L
authors.initials: SL
authors.lastname: Guérin
mesh_terms: D000328:Adult; D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D003094:Collagen / Q000378:metabolism*; D065306:Corneal Injuries / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D024202:Electrophoretic Mobility Shift Assay; D019573:Epithelium, Corneal / Q000293:injuries / Q000378:metabolism* / Q000473:pathology; D005786:Gene Expression Regulation; D006801:Humans; D039482:Integrin alpha5 / Q000096:biosynthesis / Q000235:genetics*; D008875:Middle Aged; D011401:Promoter Regions, Genetic; D012313:RNA / Q000235:genetics*; D011817:Rabbits; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D039482:Integrin alpha5; D012313:RNA; D003094:Collagen