Characterization of liver function in transdifferentiated hepatocytes
Characterization of liver function in transdifferentiated hepatocytes
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DOI：
10.1002/jcp.20438
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发表时间：
2006-01-01
影响因子：
5.6
通讯作者：
Tosh, D
中科院分区：
文献类型：
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作者：
Burke, ZD;Shen, CN;Tosh, D
我们先前证明，地塞米松（Dex）诱导胰腺祖细胞系AR 42 J-B13（B13）转分化（或转化）为肝细胞的基础上表达的肝蛋白。我们已经扩展了我们最初的观察，以确定：（1）Dex对胰腺基因表达的影响;（2）从胰腺表型到肝脏表型转化过程中肝脏富集转录因子表达的时间过程;（3）转分化肝细胞的功能潜力;（4）转分化肝细胞的增殖能力;（5）转录因子的异位表达能否诱导胰腺B13细胞的肝表型。结果如下。与对照细胞相比，B13细胞标志物淀粉酶、突触素和神经丝在转分化的肝细胞中丢失，并且首先诱导肝脏富集的转录因子C/EBP β和C/EBP α，然后是HNF 4 α，然后是RXR α。使用RT-PCR分析和免疫定位研究，我们检测了肝脏标志物（例如，载脂蛋白13）。转分化肝细胞分泌白蛋白，胰岛素刺激脂质沉积，环丙贝特增强过氧化氢酶的表达。在HGF和NEAA存在下促进转分化肝细胞的增殖，如细胞周期标志物细胞周期蛋白D和磷酸化组蛋白H3与肝蛋白的共表达所示。最后，基于HNF 4 α的核定位和UDP-葡萄糖醛酸基转移酶表达的诱导，AR 42 J-B13细胞中C/EBPa或C/EBP β的异位表达足以诱导转分化。这些结果表明，B13祖细胞模型适用于研究肝功能和理解转分化过程中发生的分子和细胞事件。
We previously demonstrated that dexramethasone (Dex) induces the transdifferentiation (or conversion) of the pancreatic progenitor cell lineAR42J-B13 (B13) to hepatocytes based on the expression of liver proteins. We have extended our original observations to determine: (I) the effects of Dex on pancreatic gene expression; (2) the time course of expression of liver enriched transcription factors during conversion from pancreatic to hepatic phenotype; (3) the functional potential of transdifferentiated hepatocytes; (4) the proliferative capacity of transdifferentiated hepatocytes; and (5) whether ectopic expression of transcription factors can induce the hepatic phenotype in pancreatic B13 cells. The results were as follows. The B13 cell markers amylase, synaptophysin, and neurofilament were lost in transdifferentiated hepatocytes compared to control cells and the liver-enriched transcription factors C/EBP beta and C/EBP alpha were induced first, followed by HNF4 alpha and then RXR alpha. Using RT-PCR analysis and immunolocalisation studies, we detected hepatic markers (e.g., apolipoprotein 13) in Dex-treated cells. In transdifferentiated hepatocytes albumin was secreted, insulin stimulated lipid deposition and ciprofibrate enhanced the expression of catalase. Proliferation of transdifferentiated hepatocytes is promoted in the presence of HGF and NEAA as indicated by the co-expression of the cell cycle markers cyclin D and phosphohistone H3 with liver proteins. Lastly, ectopic expression of C/EBPa or C/EBP beta in AR42J-B13 cells was sufficient to induce transdifferentiation, based on nuclear localization of HNF4 alpha and induction of UDP-glucuronosyltransferase expression. These results indicate that the B13 progenitor cell model is suitable for studying liver function and for understanding the molecular and cellular events that occur during transdifferentiation.