Acquisition of blood-tissue barrier-supporting features by hepatic stellate cells and astrocytes of myofibroblastic phenotype. Inverse dynamics of metallothionein and glial fibrillary acidic protein expression
Acquisition of blood-tissue barrier-supporting features by hepatic stellate cells and astrocytes of myofibroblastic phenotype. Inverse dynamics of metallothionein and glial fibrillary acidic protein expression
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DOI：
10.1016/s0197-0186(00)00116-9
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发表时间：
2001-04-01
影响因子：
4.2
通讯作者：
Gebhardt, R
中科院分区：
文献类型：
--
作者：
Buniatian, GH;Hartmann, HJ;Gebhardt, R
星形胶质细胞和肝星状细胞 (HSC) 之间的许多相似之处引发了一个问题：血液组织界面的保护屏障功能是否也可以由 HSC 提供。为了检验这一假设，我们研究了 HSC 中和细胞培养物中金属硫蛋白 (MT)（血脑屏障的功能标记物）的存在，并将结果与星形胶质细胞获得的结果进行了比较。通过同时用针对来自大鼠肝脏的镉诱导的 MT-I 单体的含赖氨酸表位的单克隆抗体 (MAb MT) 和针对神经胶质纤维酸性蛋白 (GFAP) 的抗血清来研究培养的星形胶质细胞和 HSC 中 MT 表达的动态。通过平滑肌α-肌动蛋白（SMAA）的存在来评估细胞活化。在免疫印迹中，MAb MT 可识别单体 MT 蛋白和 30 kDa 范围内的蛋白；两条带在脑中都很明显，而在肝匀浆中几乎不可见。在原位，MAb MT 与位于肝实质中的极少数血管周围细胞发生反应。用 MAb MT 和抗 GFAP 抗血清对脑切片进行双重免疫标记，显示大脑中大片区域含有同时表达 MT 和 GFAP 的细胞。然而，大脑中也有一些区域的细胞仅产生 GFAP 或 MT。在肝细胞培养中，HSC和肝细胞在培养早期不存在MT，细胞保持原有特征；然而，在长时间培养条件下，HSC 激活期间，MT 会在 HSC 中强烈表达。相反，在星形胶质细胞中，MT 在早期培养期间表达，并在培养后期当 GFAP 上调时与 SMAA 一起从细胞中消失。这些结果表明，血管周围细胞获得肌纤维母细胞特征使它们能够建立保护性血液组织通透性屏障。此外，这项研究表明，至少在细胞培养中，GFAP 中血管周围细胞的富集会导致保护功能的消失。 (C) 2001 Elsevier Science Ltd. 保留所有权利。
A number of similarities between astrocytes and hepatic stellate cells (HSC) rose the question whether or not the protective barrier features of blood-tissue interface may be provided by HSC as well. To test this hypothesis, we investigated the presence of metallothionein (MT), a functional marker of blood-brain barrier, in HSC in situ and in cell culture and compared the results with those obtained with astrocytes. The dynamics of MT expression in cultured astrocytes and HSC was investigated by simultaneous labelling of the cells with a monoclonal antibody (MAb MT) against a lysine-containing epitope of the cadmium-induced monomer of MT-I from rat liver and antiserum against glial fibrillary acidic protein (GFAP). Cell activation was estimated by the presence of smooth muscle alpha-actin (SMAA). In immunoblotting, MAb MT recognized monomeric MT protein and proteins in the 30-kDa range; both bands were pronounced in brain and barely visible in liver homogenates. In situ, MAb MT reacted with very few perivascular cells situated in the parenchyma of the liver. Double immunolabelling of brain slices with MAb MT and antiserum against GFAP showed large areas of brain containing cells expressing both MT and GFAP. However, there were also regions in the brain where the cells produced solely GFAP or MT. In liver cell culture, MT was absent from HSC and hepatocytes in early periods of cultivation, during which the cells maintained their original features; however, MT was expressed strongly in HSC during their activation under prolonged culture conditions. Inversely, in astrocytes MT was expressed during early culturing and disappeared from the cells together with SMAA in late culture when GFAP was upregulated. These results suggest that the acquisition of myofibroblastic features by perivascular cells empowers them to establish a protective blood-tissue permeability barrier. In addition, this study shows that, at least in cell culture, an enrichment of perivascular cells in GFAP results in the disappearance of protective functions. (C) 2001 Elsevier Science Ltd. All rights reserved.