Up-regulated expression of the receptor for advanced glycation end products in cultured rat hepatic stellate cells during transdifferentiation to myofibroblasts
Up-regulated expression of the receptor for advanced glycation end products in cultured rat hepatic stellate cells during transdifferentiation to myofibroblasts
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DOI：
10.1053/jhep.2001.28788
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发表时间：
2001-11-01
期刊：
影响因子：
13.5
通讯作者：
Gressner, AM
中科院分区：
文献类型：
--
作者：
Fehrenbach, H;Weiskirchen, R;Gressner, AM
晚期糖基化终产物受体 (RAGE) 是细胞表面分子免疫球蛋白超家族的成员。据报道，阻断 RAGE 可显着改善肝功能并加速肝切除术后的再生。本研究的目的是研究 RAGE 的细胞类型特异性表达，并检查肝星状细胞 (HSC) 转分化为肌成纤维细胞 (MFB) 是否与 RAGE 表达的变化相关。 Northern印迹分析显示，RAGE mRNA仅由从大鼠肝脏分离的HSC表达，而在肝细胞、Kupffer细胞或肝窦内皮细胞中未观察到转录本。 RAGE mRNA 的表达在 HSC 转分化为 MFB 过程中上调。与此同时，通过蛋白质印迹和免疫组织化学证实，RAGE 蛋白的表达增加。通过放射性标记评估，转化生长因子 β (1) (TGF-β (1)) 会诱导 RAGE 蛋白的从头合成随时间增加 2 至 15 倍，但使用丝裂原激活蛋白激酶 (MAPK) 激酶的特异性抑制剂 PD098059 可以完全消除这种情况。双免疫荧光染色显示，RAGE 与α-平滑肌肌动蛋白共定位，免疫电镜显示 MFB 丝状足膜上最显着的 RAGE 标记。总之，本研究表明 RAGE 的表达仅限于大鼠 HSC，并且在 HSC 激活和向 MFB 转变期间表达上调。 RAGE 优先免疫金标记 MFB 丝状伪足的局灶膜区域，这表明 RAGE 在活化的 HSC/MFB（肝纤维形成的主要参与者）的扩散和迁移中发挥作用。
Receptor for advanced glycation end products (RAGE) is a member of the immunoglobulin superfamily of cell-surface molecules. Blockade of RAGE has been reported to considerably improve liver function and accelerate regeneration after hepatectomy. The aim of this study was to investigate the cell type-specific expression of RAGE, and to examine whether transdifferentiation of hepatic stellate cells (HSC) into myofibroblasts (MFB) is associated with changes in RAGE expression. Northern blot analysis revealed that RAGE mRNA was exclusively expressed by HSC isolated from rat liver, while no transcripts were seen in hepatocytes, Kupffer cells, or sinusoidal endothelial cells. Expression of RAGE mRNA was up-regulated during transdifferentiation of HSC into MFB. Concomitantly, expression of RAGE protein was increased as confirmed by Western blotting and immunohistochemistry. As assessed by radioactive labeling, transforming growth factor beta (1) (TGF-beta (1)) induced a time-dependent 2- to 15-fold increase in the de novo synthesis of RAGE protein, which was completely abolished using PD098059, a specific inhibitor of the mitogen-activated protein kinase (MAPK) kinase. As shown by double-immunofluorescence staining, RAGE colocalized with a-smooth muscle actin, and immunoelectron microscopy demonstrated the most prominent labeling for RAGE at filopodial membranes of MFB. In conclusion, this study demonstrates that expression of RAGE is restricted to rat HSC, and that expression is up-regulated during activation of HSC and transition to MFB. The preferential immunogold labeling of RAGE to focal membrane areas of filopodia of MFB is suggestive of a role of RAGE in the spreading and migration of activated HSC/MFB, major players in liver fibrogenesis.