肝再生过程中胆汁酸对肝细胞cyclinD1和NTCP蛋白表达的影响

Effect of bile acids on expression of cyclin D1 and NTCP protein in hepatocytes during the process of liver regeneration

目的观察大鼠肝再生过程中胆汁酸对肝细胞周期蛋白D1(cyclin D1)和Na+依赖牛磺胆酸钠协同转运蛋白(NTCP)表达的影响。方法雄性Wistar大鼠72只随机分为胆酸缺乏组、胆酸负荷组和对照组,分别饲以2%无水考来烯胺饲料、0.2%胆酸饲料和标准饲料,7 d后行70%肝部分切除术。分别在术后6 h,12 h Western blot检测再生肝组织cyclin D1的蛋白表达,术后24 h检测NTCP的蛋白表达。结果术后6 h,胆酸缺乏组肝组织cyclin D1相对表达量显著低于对照组(0.09±0.02 vs 0.18±0.05,P<0.05),而胆酸负荷组(0.31±0.11)显著高于对照组(P<0.05)和胆酸缺乏组(P<0.01);术后12 h,胆酸缺乏组、胆酸负荷组和对照组肝组织cyclin D1的相对表达量分别为0.59±0.21,0.87±0.32和0.54±0.18,胆酸缺乏组与对照组间无统计学差异,但均显著低于负荷组(P<0.05)。术后24 h,胆酸缺乏组的NTCP蛋白相对表达量最高(0.51±0.11),而胆酸负荷组NTCP的表达量(0.23±0.05)最低,与对照组比较差异有统计学意义(P<0.05)。结论大鼠肝再生过程中,体内缺乏胆汁酸可显著降低肝组织cyclin D1蛋白的表达,同时伴有和肝细胞极性密切相关的NTCP蛋白表达的上调。

Objective To explore the effect of bile acids on expression of cyclin D1 and NTCP protein in hepatocytes during the process of liver regeneration. Methods Male Wistar rats were randomly divided into three groups. Rats were fed with 2% cholic acid for 7 d in cholic acid deficiency group,0. 2% cholic acid in cholic acid loading group,and standard feed in control group. Then 70%partial hepatectomy was performed for all rats. Regenerated liver tissue was collected at 6 h,12 h,and 24 h after the operation. The expression of cyclin D1 protein and Na＋-dependent sodium taurocholate cotransporter protein（ NTCP） was measured by Western blot.Results The expression of cyclin D1 at 6 h after the operation was significantly lower in cholic acid deficiency group than in control group（ 0. 09 ± 0. 02 vs 0. 18 ± 0. 05,P 〈 0. 05）,but it was significantly higher in cholic acid loading group（ 0. 31 ± 0. 11） than that in control group（ P 〈 0. 05） and cholic acid deficiency group（ P 〈 0. 01）. The relative expression of cyclin D1 was 0. 59 ± 0. 21,0. 54 ±0. 18 and 0. 87 ± 0. 32 at 12 h after the operation in cholic acid deficiency group,control group and cholic acid loading group,respectively. There was no significant difference in the expression of cyclin D1 at 12 h between cholic acid deficiency group and control group,but it was significantly lower than that in cholic acid loading group（ P 〈 0. 05）. Compared with control group,the expression of NTCP protein was increased at 24 h after the operation in cholic acid deficiency group（ 0. 51 ± 0. 11）,while it was decreased in cholic acid loading group（ 0. 23 ± 0. 05）. Conclusion During the process of liver regeneration,the internal deficiency of bile acids can significantly decrease the expression of cyclin D1 in liver tissue,and upregulate the expression of NTCP protein.