THE MECHANISM OF LIVER FAILURE AFTER EXCESSIVE HEPATECTOMY INVESTIGATED USING CDAN MICROARRAY

大面积肝切除术常引起致死性肝衰竭。其机制有两种说法：微环干扰引起的间接损伤引起肝细胞坏死，细胞毒性干扰引起的直接损伤引起肝细胞凋亡。过度的肝切除术常常导致致命的肝衰竭。我们已经报道了这主要是由细胞凋亡介导的，病理特征是TUNEL试验阳性肝细胞和DNA片段分析中的阶梯模式。为了研究其机制，我们使用cDNA微阵列分析比较了明确分化的大鼠部分肝切除术（PHx）模型（90%PHx和95%PHx）。90%的phx小鼠全部存活，但95%的phx小鼠在96小时内死于肝功能衰竭。在4个时间点（PHx后1、3、12、24小时）取残肝。提取RNA后，用不同的荧光染料标记两份样品，并与RIKEN的18816个全长富集小鼠cDNA序列进行杂交。对荧光染料信号进行扫描，95%PHx组的许多caspase在PHx后1小时上调。另一方面，Bcl-2、热休克蛋白和谷胱甘肽- s转移酶基因下调。我们认为过度肝切除术后致死性肝的特点是细胞凋亡增加和肝再生减少。背景/目的：肝部分切除术后肝脏具有再生能力。为了明确肝脏再生的机制，我们观察了肝脏再生的初始阶段，特别是从G0到S期（0 ~ 24小时）过程中的基因表达机制，并试图找到控制肝脏再生过程的新基因。方法：利用互补DNA （cDNA）微阵列对小鼠肝切除术模型进行大规模基因表达分析，阐明部分肝切除术后肝脏再生的机制。结果：发现了参与细胞核内转运的IRAK-1 （interleukin-1 receptor associated kinase-1）、karyophherin α 1等23个新的早期基因候选者。研究人员发现了与进入S期有关的新基因候选：ID2 （DNA结合抑制剂2）和ID3 (DNA结合抑制剂3)，这两种新的肝脏再生因子都促进了进入S期，而Gadd45 γ（生长阻滞和DNA损伤诱导蛋白）是抑制这一过程的因子。结论：上述结果不仅提示了NF-κB在肝再生初期的重要作用，也提示了肝再生过程中细胞增殖的有序维持。少

Massive hepatectomy often induced lethal hepatic failure. The mechanism has been described using two theories : indirect injury caused by microcircular disturbance induces necrosis to hepatocytes, and direct injury caused by cytotoxic disturbance induces apoptosis to hepatocyte.Exp.1Excessive hepatectomy often causes fatal liver failure. We have reported that this is mainly mediated by apoptosis, characterized pathologically by TUNEL assay positive hepatocytes and a ladder pattern in DNA fragmentation assays. To investigate the mechanism, we used a cDNA microarray analysis to compare clearly differentiated rat partial hepatectomy (PHx) models (90%PHx, and 95%PHx). All 90%PHx rats survived, but the 95%PHx animals died of hepatic failure within 96 hours. The remnant liver was obtained at 4 time points (1,3,12, and 24 hrs after PHx). After RNA extraction, two samples were labeled with different fluorescent dyes and hybridized to the RIKEN set of 18,816 full-length enriched mouse cDNA arra … More ys. Scanning for fluorescent dye signals was performed, and many caspases were upregulated at 1 hr after PHx in the 95%PHx group. On the other hand, genes of Bcl-2, heat shock proteins and gluthatione-S-transferase were downregulated. We concluded that fatal hepatic after excessive hepatectomy was characterized by increased apoptosis and diminished liver regeneration.Exp.2Background/Aim : The liver has the capacity to regenerate after partial hepatectomy. In order to clarify the mechanism of liver regeneration, we observed the initial stage, especially the mechanism of gene expression during progress from G0 to S phase (0〜24 hrs), and attempted to identify the new gene controlling progress to the S phase.Methods : We applied large-scale gene expression analysis with complementary DNA (cDNA) microarrays in mouse hepatectomy models to clarify the mechanism of liver regeneration after partial hepatectomy.Results : As a result, 23 new immediate-early gene candidates such as IRAK-1 (interleukin-1 receptor associated kinase-1) and karyopherin alpha 1, which are involved in transportation within the nucleus, were discovered. Candidates for new genes concerned with the progress to the S phase were discovered : ID2 (inhibitor of DNA binding 2) and ID3 (inhibitor of DNA binding 3), both new liver regeneration factors that promoted progress to the S phase, and Gadd45 gamma (growth arrest and DNA-damage-inducible protein) as a factor inhibiting that process.Conclusions : The above result not only suggests the importance of NF-κB in the initial stage of liver regeneration but also points to the orderly maintenance of the proliferation of the cells in liver regeneration. Less