Oda H, Nozawa K, Hitomi Y, Kakinuma A
Department of Applied Biological Sciences, Nagoya University, Japan.
Biochem Biophys Res Commun. 1995 Jul 26;212(3):800-5. doi: 10.1006/bbrc.1995.2039.
Laminin-rich extracellular matrix, EHS-gel, has been demonstrated to keep a high level of liver-specific gene expression in cultured rat hepatocytes. To obtain information about the effect of EHS-gel on liver-specific functions, gene expression of liver-enriched transcription factors in rat hepatocytes was investigated. The apolipoprotein A-I and albumin mRNA levels were higher in hepatocytes cultured on EHS-gel than in those cultured on type I collagen (TIC). The levels of mRNA for HNF-4, C/EBP alpha and C/EBP beta were also higher on EHS-gel than on TIC. The level of HNF-4 mRNA in hepatocytes on EHS-gel was almost comparable to that in liver. The HNF-3 alpha mRNA level was lower on EHS-gel than on TIC. C/EBP beta mRNA was induced by dexamethasone in both EHS-gel and TIC. The induction of C/EBP alpha and HNF-4 by dexamethasone was observed only on TIC. These data suggest that EHS-gel leads hepatocytes to keep the phenotypic expression through high expression of liver-enriched transcription factors, such as HNF-4.
富含层粘连蛋白的细胞外基质EHS凝胶已被证明能使培养的大鼠肝细胞保持高水平的肝脏特异性基因表达。为了获取有关EHS凝胶对肝脏特异性功能影响的信息，对大鼠肝细胞中肝脏富集转录因子的基因表达进行了研究。在EHS凝胶上培养的肝细胞中载脂蛋白A-I和白蛋白的mRNA水平高于在I型胶原（TIC）上培养的肝细胞。EHS凝胶上HNF-4、C/EBPα和C/EBPβ的mRNA水平也高于TIC。EHS凝胶上肝细胞中HNF-4 mRNA的水平与肝脏中的水平几乎相当。EHS凝胶上HNF-3α mRNA的水平低于TIC。地塞米松在EHS凝胶和TIC中均能诱导C/EBPβ mRNA表达。仅在TIC上观察到地塞米松对C/EBPα和HNF-4的诱导作用。这些数据表明，EHS凝胶通过HNF-4等肝脏富集转录因子的高表达引导肝细胞保持表型表达。
