The cytoskeletal elements of the epithelial cells from rat intestinal mucosa were examined by immunofluorescence microscopy using antibodies to prekeratin, vimentin, desmin, and actin and by electron microscopy. In both absorptive and globlet cells antibodies to prekeratin revealed an impressive and complex skeleton of fibrillar arrays of intermediate-sized filaments. These arrays were not stained by antibodies to desmin, which stained intestinal smooth muscle, or by antibodies to vimentin, which reacted with filaments present in mesenchymal cells of the lamina propria. The skeletal arrays decorated by antibodies to prekeratin were resistant to treatment with Triton X-100 and high salt buffer and consisted of tonofilament-like structures, including desmosome-attached tonofibrils. The intermediate-sized filaments were not found in the microvilli but cytokeratin filaments were especially concentrated in the terminal web and in a special zone subjacent to the terminal web, demarcated by a ring of desmosomes, all strongly decoratable with antibodies to prekeratin ('apical skeletal disc'). The central cytoplasm was filled by a three-dimensional meshwork of cytokeratin fibrils, excluding the nucleus and, in the case of the goblet cells, the thecal region containing the secretory granules. This three-dimensional meshwork of cytokeratin-containing filaments was continuous with - and inserted at - the apical skeletal disc, including the desmosomes, on the apical side and another dense aggregate of cytokeratin filaments located at the base of the cells. The results demonstrate the overall architecture of cytoskeletal arrays of intermediate-sized filaments in a cell present in a tissue. In addition, they show that normal epithelial cells contain a complex system of cytokeratin filaments which is involved in the establishment and maintenance of the specific polar organization of these cells.
|Original language||English (US)|
|Number of pages||14|
|Journal||European journal of cell biology|
|State||Published - Dec 1 1979|
ASJC Scopus subject areas
- Pathology and Forensic Medicine
- Cell Biology