Yang Shu, Leow Chon Kar, Tan Theresa May Chin
Department of Biochemistry, Faculty of Medicine, National University of Singapore, MD7, 8 Medical Drive, S117597, Singapore.
World J Gastroenterol. 2006 Feb 21;12(7):1063-70. doi: 10.3748/wjg.v12.i7.1070.
To examine the differences in the responses of normal and cirrhotic livers to partial hepatectomy in relation to the factors influencing liver regeneration.
Cirrhosis was induced in rats by administration of thioacetamide. Untreated rats were used as controls. The control rats as well as the cirrhotic rats were subjected to 70% partial hepatectomy. At different time points after hepatectomy, the livers were collected and the levels of cytokines, growth factors and cell cycle proteins were analyzed.
After hepatectomy, the cirrhotic remnant expressed significantly lower levels of cyclin D1, its kinase partner, cdk4, and cyclin E as compared to the controls up to 72 h post hepatectomy. Significantly lower levels of cyclin A and cdk2 were also observed while the cdk inhibitor, p27 was significantly higher. In addition, the cirrhotic group had lower IL-6 levels than the control group at all time points up to 72 h following resection.
The data from our study shows that impaired liver regeneration in cirrhotic remnants is associated with low expression of cyclins and cdks. This might be the consequence of the low IL-6 levels in cirrhotic liver remnant which would in turn influence the actions of transcription factors that regulate genes involved in cell proliferation and metabolic homeostasis during the regeneration process.
研究正常肝脏和肝硬化肝脏对部分肝切除术的反应差异,以及与肝再生相关的影响因素。
通过给予硫代乙酰胺诱导大鼠肝硬化。未处理的大鼠作为对照。对照大鼠和肝硬化大鼠均接受70%部分肝切除术。在肝切除术后不同时间点,收集肝脏并分析细胞因子、生长因子和细胞周期蛋白的水平。
肝切除术后,直至术后72小时,肝硬化残余肝脏中细胞周期蛋白D1、其激酶伴侣细胞周期蛋白依赖性激酶4(cdk4)和细胞周期蛋白E的表达水平均显著低于对照组。细胞周期蛋白A和cdk2的水平也显著降低,而细胞周期蛋白依赖性激酶抑制剂p27水平显著升高。此外,在切除术后直至72小时的所有时间点,肝硬化组的白细胞介素-6(IL-6)水平均低于对照组。
我们的研究数据表明,肝硬化残余肝脏中肝再生受损与细胞周期蛋白和细胞周期蛋白依赖性激酶的低表达有关。这可能是肝硬化肝脏残余中IL-6水平低的结果,进而会影响在再生过程中调节参与细胞增殖和代谢稳态的基因的转录因子的作用。