Schnabel Claudia, Sawitza Iris, Tag Carmen G., Lahme Birgit, Gressner Axel M., Breitkopf Katja
Department of Clinical Chemistry and Pathobiochemistry, Central Laboratory, 52074 Aachen, Germany.
Hepatol Res. 2004 Mar;28(3):140-145. doi: 10.1016/j.hepres.2003.11.004.
Transdifferentiation of hepatic stellate cells (HSC) to collagen producing myofibroblasts (MFB) is a principal event in liver fibrogenesis. In our studies we investigated if tissue transglutaminase (tTG) from these cell types may play a role in liver fibrosis. Separation of cytosol and membrane components showed membrane associated tTG and during transdifferentiation an upregulation of total tTG on mRNA and protein level was found, but no modulation during stimulation with TGF-beta1. In HSC and fully differentiated MFB a significant amount of the total tTG synthesised during transdifferentiation is found to be membrane-associated whereas the remaining portion is cytosol-associated and only very little is found within the extracellular matrix (ECM). The data implicate that tTG in this cell type seems to play an important role in liver fibrogenesis.
肝星状细胞（HSC）向产生胶原蛋白的肌成纤维细胞（MFB）转分化是肝纤维化形成过程中的主要事件。在我们的研究中，我们调查了这些细胞类型中的组织转谷氨酰胺酶（tTG）是否可能在肝纤维化中发挥作用。细胞质和膜成分的分离显示膜相关的tTG，并且在转分化过程中发现总tTG在mRNA和蛋白质水平上上调，但在用转化生长因子-β1（TGF-β1）刺激期间没有调节作用。在HSC和完全分化的MFB中，发现在转分化过程中合成的总tTG中有相当一部分与膜相关，而其余部分与细胞质相关，并且在细胞外基质（ECM）中仅发现很少量。数据表明，这种细胞类型中的tTG似乎在肝纤维化中起重要作用。
