Morphological aspects of interactions between asbestos fibers and human mesothelial cell cytoskeleton.

The interaction of chrysotile and amphibole asbestos fibers with the cytoskeleton of cultured human mesothelial cells from nontumoral pleural effusions was studied using scanning electron and immunofluorescence microscopy. Asbestos-exposed mesothelial cells show a massive annular condensation of cytokeratin filaments, forming a concentric ring enveloping the nucleus and the phagocytosed asbestos fibers. By detergent extraction of the cells it could be shown that the asbestos fibers are in close contact with the nuclear membrane and associated with the cytoskeletal framework of the cells. An association of cytokeratin filaments with the asbestos could be observed during phagocytosis of the fibers. The disturbance of the cell cytoskeleton and the close morphologic contact between asbestos fibers and the nuclear membrane may have some relevance in explaining the well-recognized carcinogenic effects of asbestos mineral fibers.