The aim of this study was to determine whether colchicine, which has been reported to protect against various hepatotoxic insults, influences the susceptibility of mice to the agonistic anti-Fas antibody, Jo2. All mice that were pretreated with colchicine (2 mg/kg) survived the lethal challenge of intraperitoneal administration of 10 μg of Jo2, whereas all control mice pretreated with γ-lumicolchicine succumbed to the challenge. Twelve micrograms of Jo2 killed less than half of colchicine-pretreated mice and its lethal effects were delayed relative to control mice, which all died within 8 hours. Other microtubule-disrupting agents such as Taxol, vinblastine, and nocodazole also improved the survival of mice treated with the lethal dose of Jo2. Histologic examination showed that colchicine protected against Jo2-induced fulminant liver injury, and TUNEL assay demonstrated that colchicine protected against massive apoptosis of hepatocytes. Hepatocytes isolated from colchicine-pretreated mice exhibited decreased susceptibility to Jo2-induced apoptosis. In addition, colchicine pretreatment reduced surface expression of Fas and decreased Jo2- and TNF-α–induced apoptosis of cultured hepatocytes in the presence of actinomycin D, but did not affect the susceptibility of cultured sinusoidal endothelial cells to Jo2-induced apoptosis. Remarkably, Fas and TNF receptor-1 mRNA and intracellular protein levels increased after colchicine treatment, indicating that colchicine protects against death ligand–induced apoptosis in the liver by decreasing death-receptor targeting to the cell surface.
Guoping Feng, Neil Kaplowitz