Increased susceptibility of cholangiocytes to tumor necrosis factor-α cytotoxicity after bile duct ligation

Abstract

Tumor necrosis factor (TNF)-α plays a critical role in epithelial cell injury. However, the role of TNF-α in mediating cholangiocyte injury under physiological or pathophysiological conditions is unknown. Thus we assessed the effects of TNF-α alone or following sensitization by actinomycin D on cell apoptosis, proliferation, and basal and secretin-stimulated ductal secretion in cholangiocytes from normal or bile duct-ligated (BDL) rats. Cholangiocytes from normal or BDL rats were highly resistant to TNF-α alone. However, presensitization by actinomycin D increased apoptosis in cholangiocytes following BDL and was associated with an inhibition of proliferation and secretin-stimulated ductal secretion. Thus TNF-α mediates cholangiocyte injury and altered ductal secretion following bile duct ligation. These observations suggest that cholestasis may enhance susceptibility to cytokine-mediated cholangiocyte injury.