title: Co-culture of two MDCK strains with distinct junctional protein expression: a model for intercellular junction rearrangement and cell sorting.
abstract: Distinct epithelial MDCK cell strains displaying extremes in transepithelial electrical resistance (paracellular permeability) have been established in co-culture and the subsequent cellular behaviour and formation of junctional complexes investigated. After high-density seeding, MDCK strain I and II cells in co-culture are initially randomly distributed but subsequently sort themselves out in a time-dependent manner to form separate homotypic aggregates. The final pattern of cell arrangement of homotypic aggregates depends on the relative seeding proportion of each cell type. Immunostaining of established marker proteins for junctional complexes has revealed that MDCK I and II cells differ in the degree of expression of the zonula-adherens-associated protein, E-cadherin, their cytoskeletal architecture and the junctional distribution of a desmosomal protein, and by showing subtle differences in tight junction staining for the zona-occludens-associated proteins, ZO-1 and occludin. The distinct pattern of junctional protein expression is maintained when the two MDCK strains are co-cultured; however, morphologically atypical intercellular junctions between heterotypic cells at the boundary of homotypic cell aggregates have been observed. It has been suggested that cell sorting, a phenomenon yet to be completely understood, is involved in important morphogenetic processes. We propose that co-culture of strains of the well-characterised MDCK cell line may be a novel but well-defined cell system for studying epithelial cell rearrangement and sorting in intact epithelial sheets.
authors.affiliation: Department of Physiological Sciences, University of Newcastle upon Tyne, Medical School, Newcastle upon Tyne, NE2 4HH, UK.
authors.forename: C B
authors.initials: CB
authors.lastname: Collares-Buzato
authors.forename: M A
authors.initials: MA
authors.lastname: Jepson
authors.forename: G T
authors.initials: GT
authors.lastname: McEwan
authors.forename: B H
authors.initials: BH
authors.lastname: Hirst
authors.forename: N L
authors.initials: NL
authors.lastname: Simmons
mesh_terms: D000818:Animals; D015820:Cadherins / Q000032:analysis / Q000502:physiology*; D002448:Cell Adhesion / Q000502:physiology; D015815:Cell Adhesion Molecules / Q000032:analysis; D002449:Cell Aggregation / Q000502:physiology; D002463:Cell Membrane Permeability; D018920:Coculture Techniques; D004285:Dogs; D004847:Epithelial Cells / Q000737:chemistry / Q000502:physiology*; D007365:Intercellular Junctions / Q000737:chemistry* / Q000502:physiology; D007668:Kidney / Q000166:cytology*; D008564:Membrane Potentials; D008565:Membrane Proteins / Q000032:analysis / Q000502:physiology*; D008854:Microscopy, Electron; D008856:Microscopy, Fluorescence; D009024:Morphogenesis; D062793:Occludin; D010750:Phosphoproteins / Q000032:analysis / Q000502:physiology*; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D062826:Zonula Occludens-1 Protein
chemical_list: D015820:Cadherins; D015815:Cell Adhesion Molecules; D008565:Membrane Proteins; D062793:Occludin; D010750:Phosphoproteins; D062826:Zonula Occludens-1 Protein; D011505:Protein-Tyrosine Kinases