title: Organ-specific matrix self-assembled by mesenchymal cells improves the normal urothelial differentiation in vitro.
abstract: OBJECTIVE
  Enterocystoplasty is the gold standard to perform bladder reconstruction. Since this technique has a high morbidity rate, several matrix scaffolds have been proposed to support the urothelial maturation. Unfortunately, epithelial cells failed to fully integrate the cell-matrix interactions and therefore appropriate signalling pathways of normal differentiation. Based on these observations, we proposed to culture bladder urothelial cells (BUC) onto a matrix self-assembled by bladder mesenchymal cells (BMC), to form a vesical model (VM).
  
  
  METHODS
  Different serum proportions were assessed to obtain a manipulable matrix deposited by BMC. The BUC were then seeded onto the BMC's matrix to evolve in a three-dimensional culture. Haematoxylin-eosin staining, immunolabeling, scanning electron microscopy, western blot and matrix metalloproteinases analysis were performed for the VM characterization.
  
  
  RESULTS
  We were able to obtain an original matrix made of collagen-I and presenting specific organization. Matrix remodelling was observed and led to a cellular compartmentalization. The reconstructed urothelium developed in a pseudostratified arrangement, displaying an adequate cellular polarity and apical membrane remodelling of superficial cells. Like native bladder, cytokeratin 14 immunolabeling was not observed in our VM, which indicate the conformity of the development sequence taken by BUC under the influence of the BMC's matrix.
  
  
  CONCLUSIONS
  Thus, it was possible to elaborate a VM without the use of exogenous matrices. The particular characteristics of the BMC's matrix permitted the development of an urothelium that shared the phenotype of native tissue. The autologous character of our VM, and its appropriate urothelial maturation, could potentially promote a better integration after grafting.
authors.affiliation: Centre de recherche en organogénèse expérimentale de l'Université Laval/LOEX Faculté de médecine, Centre de Recherche du CHU de Québec, Université Laval, Québec, Canada. sara.ucergy@hotmail.fr.
authors.forename: S
authors.initials: S
authors.lastname: Bouhout
authors.affiliation: Centre de recherche en organogénèse expérimentale de l'Université Laval/LOEX Faculté de médecine, Centre de Recherche du CHU de Québec, Université Laval, Québec, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Chabaud
authors.affiliation: Centre de recherche en organogénèse expérimentale de l'Université Laval/LOEX Faculté de médecine, Centre de Recherche du CHU de Québec, Université Laval, Québec, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Bolduc
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002454:Cell Differentiation; D016764:Cell Polarity; D002478:Cells, Cultured; D024042:Collagen Type I / Q000378:metabolism*; D005109:Extracellular Matrix / Q000378:metabolism*; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D007421:Intestine, Small / Q000601:surgery; D053547:Keratin-14 / Q000378:metabolism; D020782:Matrix Metalloproteinases / Q000378:metabolism*; D008648:Mesoderm / Q000166:cytology*; D008855:Microscopy, Electron, Scanning; D019651:Plastic Surgery Procedures; D013552:Swine; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds; D001743:Urinary Bladder / Q000601:surgery; D019459:Urothelium / Q000254:growth & development* / Q000378:metabolism / Q000648:ultrastructure
chemical_list: D024042:Collagen Type I; D053547:Keratin-14; D020782:Matrix Metalloproteinases
keywords: Bladder mesenchymal cells; Matrix remodelling; Tissue-engineered urothelium; Vesical model