Ros J E, Roskams T A D, Geuken M, Havinga R, Splinter P L, Petersen B E, LaRusso N F, van der Kolk D M, Kuipers F, Faber K N, Müller M, Jansen P L M
Groningen University Institute for Drug Exploration (GUIDE), Centre for the Study of Liver, Digestive, and Metabolic Diseases, University Hospital Groningen, 9700 RB Groningen, the Netherlands.
Gut. 2003 Jul;52(7):1060-7. doi: 10.1136/gut.52.7.1060.
Liver regeneration after severe liver damage depends in part on proliferation and differentiation of hepatic progenitor cells (HPCs). Under these conditions they must be able to withstand the toxic milieu of the damaged liver. ATP binding cassette (ABC) transporters are cytoprotective efflux pumps that may contribute to the preservation of these cells. The aim of this study was to determine the ABC transporter phenotype of HPCs.
HPC activation was studied in rats treated with 2- acetylaminofluorene (2-AAF) followed by partial hepatectomy (PHx). ABC transporter gene expression was determined by real time detection reverse transcription-polymerase chain reaction in isolated HPCs, hepatocytes, cholangiocytes, and cultured progenitor cell-like RLF phi 13 cells and by immunohistochemistry of total liver samples. ABC transporter efflux activity was studied in RLF phi 13 cells by flow cytometry.
2-AAF/PHx treated animals showed increased hepatic mRNA levels of the genes encoding multidrug resistance proteins Mdr1b, Mrp1, and Mrp3. Immunohistochemistry demonstrated expression of Mrp1 and Mrp3 proteins in periportal progenitor cells and of the Mdr1b protein in periportal hepatocytes. Freshly isolated Thy-1 positive cells and cultured RLF phi 13 progenitor cells highly expressed Mrp1 and Mrp3 mRNA while the hepatocyte specific transporters Mdr2, Bsep, Mrp2, and Mrp6 were only minimally expressed. Blocking Mrp activity by MK-571 resulted in accumulation of the Mrp specific substrate carboxyfluorescein in RLF phi 13 cells.
HPCs express high levels of active Mrp1 and Mrp3. These may have a cytoprotective role in conditions of severe hepatotoxicity.
严重肝损伤后的肝再生部分依赖于肝祖细胞（HPCs）的增殖与分化。在这些情况下，它们必须能够耐受受损肝脏的毒性环境。ATP结合盒（ABC）转运蛋白是具有细胞保护作用的外排泵，可能有助于这些细胞的存活。本研究旨在确定HPCs的ABC转运蛋白表型。
在给予2-乙酰氨基芴（2-AAF）后行部分肝切除术（PHx）的大鼠中研究HPCs的激活情况。通过实时检测逆转录-聚合酶链反应在分离的HPCs、肝细胞、胆管细胞及培养的祖细胞样RLF phi 13细胞中以及通过全肝样本的免疫组织化学来测定ABC转运蛋白基因表达。通过流式细胞术在RLF phi 13细胞中研究ABC转运蛋白的外排活性。
2-AAF/PHx处理的动物肝脏中编码多药耐药蛋白Mdr1b、Mrp1和Mrp3的基因的mRNA水平升高。免疫组织化学显示门静脉周围祖细胞中有Mrp1和Mrp3蛋白表达，门静脉周围肝细胞中有Mdr1b蛋白表达。新鲜分离的Thy-1阳性细胞及培养的RLF phi 13祖细胞高表达Mrp1和Mrp3 mRNA，而肝细胞特异性转运蛋白Mdr2、Bsep、Mrp2和Mrp6仅微量表达。用MK-571阻断Mrp活性导致RLF phi 13细胞中Mrp特异性底物羧基荧光素积聚。
HPCs高水平表达活性Mrp1和Mrp3。在严重肝毒性情况下，这些蛋白可能具有细胞保护作用。
