Cross-linked cytokeratin polypeptides in liver and hepatoma cells: possible association with the process of cell degeneration and death.
We investigated transglutaminase-induced cross-linking of cytokeratin polypeptides in liver and hepatoma cells. To overcome the difficulties in the biochemical analysis of highly cross-linked polymers and aggregates of cytokeratins, cross-linked cytokeratin dimers were analyzed by immunoblotting to evaluate the degree of cross-linking of cytokeratins. Covalently cross-linked cytokeratin dimers were not detectable in normal rat liver cells. However, cytokeratin dimers and high-molecular-weight cytokeratin polymers were detected in liver tissue with histological evidence of coagulative necrosis induced by ischemia or carbon tetrachloride. Treatment of cultured hepatoma cells with the Ca2+ ionophore A23187 showed a dose-dependent, time-dependent decrease of cell viability. The appearance of cytokeratin dimers was shown to be correlated with cell death. These results suggest that the transglutaminase-induced cross-linking of cytokeratin polypeptides in liver and hepatoma cells is closely associated with the process of cell degeneration and death.
Fukuda
K
K
First Department of Pathology, Kurume University School of Medicine, Japan.
Kojiro
M
M
Chiu
J F
JF
D000818:Animals; D002251:Carbon Tetrachloride / Q000494:pharmacology; D002470:Cell Survival; D007511:Ischemia / Q000378:metabolism / Q000473:pathology; D007633:Keratins / Q000737:chemistry / Q000378:metabolism*; D008099:Liver / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D008102:Liver Circulation; D008113:Liver Neoplasms / Q000378:metabolism* / Q000473:pathology; D008114:Liver Neoplasms, Experimental / Q000378:metabolism* / Q000473:pathology; D008297:Male; D009336:Necrosis; D010455:Peptides / Q000737:chemistry / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D014407:Tumor Cells, Cultured
D010455:Peptides; D007633:Keratins; D002251:Carbon Tetrachloride