Biecker Erwin, De Gottardi Andrea, Neef Markus, Unternährer Matthias, Schneider Vreni, Ledermann Monika, Sägesser Hans, Shaw Sidney, Reichen Jürg
Department of Clinical Pharmacology, University of Berne, Switzerland.
J Pharmacol Exp Ther. 2005 Jun;313(3):952-61. doi: 10.1124/jpet.104.079616. Epub 2005 Mar 15.
Rapamycin is an immunosuppressant with antiproliferative properties. We investigated whether rapamycin treatment of bile duct-ligated (BDL) rats is capable of inhibiting liver fibrosis and thereby affecting hemodynamics. Following BDL, rats were treated for 28 days with rapamycin (BDL SIR). BDL animals without drug treatment (BDL CTR) and sham-operated animals served as controls. After 28 days, hemodynamics were measured, and livers were harvested for histology/immunohistochemistry. Liver mRNA levels of transforming growth factor (TGF)-beta1, connective tissue growth factor (CTGF), platelet-derived growth factor (PDGF)-beta, cyclin-dependent kinase inhibitor p27(kip) (p27), and cyclin-dependent kinase inhibitor p21(WAF1/CIP1) (p21) were quantified by real-time polymerase chain reaction. Liver protein levels of p27, p21, p70 S6 kinase (p70(s6k)), phosphorylated p70(s6k) (p-p70(s6k)), eukaryotic initiation factor 4E-binding protein (4E-BP1), p-4E-BP1 (Thr37/46), and p-4E-BP1 (Ser65/Thr70) were determined by Western blotting. Portal vein pressure was lower in BDL SIR than in BDL CTR animals. Volume fractions of connective tissue, bile duct epithelial, and desmin- and actin-positive cells were lower in BDL SIR than in BDL CTR rats. On the mRNA level, TGF-beta1, CTGF, and PDGF were decreased by rapamycin. p27 and p21 mRNA did not differ. On the protein level, rapamycin increased p27 and decreased p21 levels. Levels of nonphosphorylated p70(s6k) and 4E-BP1 did not vary between groups, but levels of p-p70(s6k) were decreased by rapamycin. Rapamycin had no effect on p-4E-BP1 (Thr37/46) and p-4E-BP1 (Ser65/Thr70) levels. In BDL rats, rapamycin inhibits liver fibrosis and ameliorates portal hypertension. This is paralleled by decreased levels of TGF-beta1, CTGF, and PDGF. Rapamycin influences the cell cycle by up-regulation of p27, down-regulation of p21, and inhibition of p70(s6k) phosphorylation.
雷帕霉素是一种具有抗增殖特性的免疫抑制剂。我们研究了雷帕霉素治疗胆管结扎（BDL）大鼠是否能够抑制肝纤维化，从而影响血流动力学。BDL术后，大鼠接受雷帕霉素治疗28天（BDL SIR）。未接受药物治疗的BDL动物（BDL CTR）和假手术动物作为对照。28天后，测量血流动力学，并采集肝脏进行组织学/免疫组织化学检查。通过实时聚合酶链反应定量测定肝脏中转化生长因子（TGF）-β1、结缔组织生长因子（CTGF）、血小板衍生生长因子（PDGF）-β、细胞周期蛋白依赖性激酶抑制剂p27（kip）（p27）和细胞周期蛋白依赖性激酶抑制剂p21（WAF1/CIP1）（p21）的mRNA水平。通过蛋白质印迹法测定肝脏中p27、p21、p70 S6激酶（p70（s6k））、磷酸化p70（s6k）（p-p70（s6k））、真核起始因子4E结合蛋白（4E-BP1）、p-4E-BP1（Thr37/46）和p-4E-BP1（Ser65/Thr70）的蛋白水平。BDL SIR组的门静脉压力低于BDL CTR组动物。BDL SIR组的结缔组织、胆管上皮以及结蛋白和肌动蛋白阳性细胞的体积分数低于BDL CTR组大鼠。在mRNA水平上，雷帕霉素使TGF-β1、CTGF和PDGF降低。p27和p21的mRNA水平无差异。在蛋白水平上，雷帕霉素使p27增加，p21水平降低。各组间非磷酸化p70（s6k）和4E-BP1的水平无变化，但雷帕霉素使p-p70（s6k）的水平降低。雷帕霉素对p-4E-BP1（Thr37/46）和p-4E-BP1（Ser65/Thr70）的水平无影响。在BDL大鼠中，雷帕霉素抑制肝纤维化并改善门静脉高压。这与TGF-β1、CTGF和PDGF水平降低相平行。雷帕霉素通过上调p27、下调p21以及抑制p70（s6k）磷酸化来影响细胞周期。
