The aim of this study was to determine whether taurocholate prevents vagotomy-induced cholangiocyte apoptosis. After bile duct ligation (BDL) + vagotomy, rats were fed taurocholate for 1 wk in the absence or presence of wortmannin. Caspase involvement was evaluated by measurement of caspase 8, 9, and 3 activities. Proliferation was determined by morphometry and PCNA immunoblots. Changes in phosphatidylinositol 3-kinase (PI3-kinase) activity were estimated by the expression of the phosphorylated Akt protein. Apically located Na+-dependent bile acid transporter (ABAT) expression and activity were evaluated by immunoblots and [3H]taurocholate uptake, respectively. Cholangiocyte apoptosis increased, whereas proliferation decreased in BDL + vagotomy rats. Taurocholate feeding prevented vagotomy effects on cholangiocyte functions, which were abolished by wortmannin. ABAT expression and activity as well as phosphorylated Akt protein expression were reduced by vagotomy but restored by taurocholate. The activities of caspase 8, 9, and 3 increased in BDL + vagotomy rats but were restored by taurocholate. The protective effect of taurocholate was associated with maintenance of ABAT activity, downregulation of caspase 8, 9, and 3, and activation of PI3-kinase. Bile acids are important in modulating cholangiocyte proliferation in denervated livers.

Brief educational interventions may alter some stigmatizing negative attitudes toward mental illness in healthcare trainees in low- and middle-income countries.

Cholangiocarcinoma is an aggressive malignancy of the biliary tract for which effective treatment is lacking. Tannic acid (TA) is a naturally occurring polyphenolic compound with antioxidant and radical scavenging properties as well as anticarcinogenic effects. TA inhibited proliferation of malignant human cholangiocytes in vitro. Furthermore, the growth rate of Mz-ChA-1 cholangiocarcinoma xenografts in balb/c athymic mice was reduced from 10.9 ؎ 1.8 mm 3 /d in mice fed with normal water to 5.5 ؎ 1.2 mm 3 /d in mice fed with water containing 0.05% TA. Pretreatment with 50 g/mL TA for 24 hours before xenograft implantation increased tumor latency by 2.5-fold compared with untreated controls, and decreased subsequent growth rates compared with controls in the absence of TA feeding. TA was not cytotoxic to Mz-ChA-1 cells in vitro, but enhanced sensitivity to camptothecin cytotoxicity. TA potently inhibited cell cycle progression, and increased expression of the cyclin-dependent kinase inhibitor p27 KIP1 . In addition, TA (0-50 g/mL) inhibited proteasomal activity in cholangiocyte cell extracts in a concentration-dependent manner. In conclusion, the growth inhibitory effects of TA may result from dysregulation of cell cycle progression due to altered proteasomal degradation of these cell cycle regulatory proteins. TA warrants evaluation as a candidate for the treatment of human cholangiocarcinoma either by itself or in combination with other chemotherapeutic agents. (HEPATOLOGY 2003;37: 1097-1104.)

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The p38 mitogen-activated protein kinase (MAPK) signaling pathway is aberrantly expressed and maintains transformed cell growth in malignant human cholangiocytes. Because cell growth requires and is intimately related to protein synthesis, our aims were to assess the effect of p38 MAPK signaling on protein synthesis during growth of malignant human cholangiocytes. Inhibition of p38 MAPK activity during mitogenic stimulation decreased protein synthesis rates and tumor cell xenograft growth in nude mice. Altered protein synthesis resulted from decreased translational efficiency with impaired initiation of translation. Mitogenic stimulation resulted in phosphorylation of the eukaryotic initiation factor (eIF)-4E. Inhibition of p38 MAPK signaling or functional dysregulation of translation by small interfering double-stranded RNA (siRNA) to eIF-4E decreased anchorage-independent growth of malignant cholangiocytes. In conclusion, these studies identify a relationship between p38 MAPK activity and the regulation of protein synthesis during human cholangiocarcinoma growth. As protein synthesis is intimately linked to cell growth, dysregulation of translation initiation is a mechanism by which cellular p38 MAPK signaling participates in growth regulation of malignant cholangiocytes. (HEPATOLOGY 2003;38:158-166.)