Redistribution of fibronectin and keratin localization patterns in early wounded confluent PtK2 cells

Single and double-label immunofluorescence were used to study the fibronectin (FN) and keratins (Ks) localization patterns in early wounded confluent PtK2 cells. A time-course study (0 hr, 2 hr, 6 hr and 24 hr) gives the following results: before wounding, the FN localizations of confluent cells are composed of curved and sometimes branched strands or fibrils. The Ks network is formed by radial fluorescent filaments connecting the Ks centers near the nuclei with a linear fluorescence underlying the cell membrane. Two hr after, the FN localizations are redistributed at the cell-cell contact areas. The radial Ks filaments are compacted around the nuclei, some of them delineate the cytoplasmic periphery of the wounded cells. Six hr later, the method shows redistributed FN localizations at the cell-cell contact areas. An alveolar pattern is formed enclosing each of the adjacent cells. The codetected Ks filaments are retracted around the nuclei. The underlying cell-cell contact areas are also well demonstrated. It may be noted that these areas are FN-labelled. Twenty-four hr after wounding, the FN alveolar pattern persists. The redistributed Ks filaments have some similarity to those seen before wounding.