环磷酸腺苷（cAMP）通过蛋白激酶A（PKA）/Src/丝裂原活化蛋白激酶激酶（MEK）/细胞外信号调节激酶1/2（ERK1/2）信号通路的变化，刺激大鼠肝内胆管上皮细胞的分泌和增殖能力。

cAMP stimulates the secretory and proliferative capacity of the rat intrahepatic biliary epithelium through changes in the PKA/Src/MEK/ERK1/2 pathway.

作者信息

Francis Heather, Glaser Shannon, Ueno Yoshiyuki, Lesage Gene, Marucci Luca, Benedetti Antonio, Taffetani Silvia, Marzioni Marco, Alvaro Domenico, Venter Julie, Reichenbach Ramona, Fava Giammarco, Phinizy Jo Lynne, Alpini Gianfranco

机构信息

Division of Research and Education, Scott and White Hospital, The Texas A&M University System Health Science Center, College of Medicine, Temple, TX 76504, USA.

出版信息

J Hepatol. 2004 Oct;41(4):528-37. doi: 10.1016/j.jhep.2004.06.009.

DOI:10.1016/j.jhep.2004.06.009

PMID:15464232

Abstract

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.

摘要

背景/目的：评估仅增加胆管细胞环磷酸腺苷（cAMP）水平是否足以增强胆管细胞增殖和分泌。

方法

正常大鼠在体内用福斯高林处理两周。评估胆管细胞凋亡、增殖和分泌情况。将来自正常大鼠的纯化胆管细胞在体外分别用福斯高林处理，同时或不同时添加Rp-cAMPs（一种蛋白激酶A（PKA）抑制剂）、PP2（一种Src抑制剂）或PD98059（一种丝裂原活化蛋白激酶/细胞外信号调节激酶（MEK）抑制剂）。随后，通过免疫印迹法测定增殖细胞核抗原（PCNA）蛋白表达来评估胆管细胞增殖。我们评估福斯高林对胆管细胞功能的影响是否与cAMP/PKA/Src/MEK/细胞外信号调节激酶1/2（ERK1/2）信号通路的变化有关。

结果

与对照组相比，对正常大鼠长期给予福斯高林可增加胆管数量、cAMP水平以及促胰液素诱导的胆汁分泌。福斯高林诱导的胆管细胞增殖和分泌增加未伴有胆管细胞坏死、炎症和凋亡。在体外，在纯分离的胆管细胞中，福斯高林增加胆管细胞增殖，而Rp-cAMPs、PP2和PD98059可消除这种增殖。福斯高林对胆管细胞增殖的影响与PKA、Src酪氨酸139（Tyr 139）和ERK1/2活性增加有关。