cAMP stimulates the secretory and proliferative capacity of the rat intrahepatic biliary epithelium through changes in the PKA/Src/MEK/ERK1/2 pathway
cAMP stimulates the secretory and proliferative capacity of the rat intrahepatic biliary epithelium through changes in the PKA/Src/MEK/ERK1/2 pathway
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DOI：
10.1016/j.jhep.2004.06.009
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发表时间：
2004-10-01
影响因子：
25.7
通讯作者：
Alpini, G
中科院分区：
文献类型：
--
作者：
Francis, H;Glaser, S;Alpini, G
背景/目的：评价单独增加胆管细胞cAMP水平是否足以促进胆管细胞增殖和分泌。方法：正常大鼠经福斯克林体内治疗2周。观察胆管细胞凋亡、增殖及分泌情况。纯化的正常大鼠胆管细胞在体外用福斯可林处理，不含Rp-cAMPs（一种PKA抑制剂）、PP2（一种Src抑制剂）或PD98059（一种MEK抑制剂）。随后，我们通过免疫印迹法测定增殖细胞核抗原（PCNA）蛋白的表达来评估胆管细胞的增殖。我们评估了福斯克林对胆管细胞功能的影响是否与cAMP/PKA/Src/MEK/ERK1/2通路的改变有关。结果：与对照组相比，正常大鼠长期服用福斯克林增加了胆管数量、cAMP水平和分泌素诱导的胆汁分泌。福斯克林诱导的胆管细胞增殖和分泌增加不伴有胆管细胞坏死、炎症和凋亡。在体外，在纯分离的胆管细胞中，福斯克林增加了胆管细胞的增殖，这被Rp-cAMPs、PP2和PD98059所消除。福斯克林对胆管细胞增殖的影响与PKA、Src酪氨酸139 （Tyr 139）和ERK1/2活性的增加有关。结论：PKA/Src/MEK/ERK1/2通路的调节可能在胆汁淤积性肝病中观察到的胆管细胞生长和分泌的调节中起重要作用。(C) 2004年欧洲肝脏研究协会。Elsevier B.V.版权所有。
Background/Aims: To evaluate if increased cholangiocyte cAMP levels alone are sufficient to enhance cholangiocyte proliferation and secretion.Methods: Normal rats were treated in vivo with forskolin for two weeks. Cholangiocyte apoptosis, proliferation and secretion were evaluated. Purified cholangiocytes from normal rats were treated in vitro with forskolin in the absence or presence of Rp-cAMPs (a PKA inhibitor), PP2 (an Src inhibitor) or PD98059 (a MEK inhibitor). Subsequently, we evaluated cholangiocyte proliferation by determination of proliferating cellular nuclear antigen (PCNA) protein expression by immunoblots. We evaluated if the effects of forskolin on cholangiocyte functions are associated with changes in the cAMP/PKA/Src/MEK/ERK1/2 pathway.Results: Chronic administration of forskolin to normal rats increased the number of ducts, cAMP levels, and secretin-induced choleresis compared to controls. Forskolin-induced increases in cholangiocyte proliferation and secretion were devoid of cholangiocyte necrosis, inflammation and apoptosis. In vitro, in pure isolated cholangiocytes, forskolin increased cholangiocyte proliferation, which was ablated by Rp-cAMPs, PP2 and PD98059. The effects of forskolin on cholangiocyte proliferation were associated with increased activity of PKA, Src Tyrosine 139 (Tyr 139) and ERK1/2.Conclusions: Modulation of the PKA/Src/MEK/ERK1/2 pathway may be important in the regulation of cholangiocyte growth and secretion observed in cholestatic liver diseases. (C) 2004 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.