Class VI intermediate filament protein nestin is induced during activation of rat hepatic stellate cells
Class VI intermediate filament protein nestin is induced during activation of rat hepatic stellate cells
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DOI：
10.1002/hep.510290232
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发表时间：
1999-02-01
期刊：
影响因子：
13.5
通讯作者：
Geerts, A
中科院分区：
文献类型：
--
作者：
Niki, T;Pekny, M;Geerts, A
肝星状细胞被认为是肝脏特异性周细胞，在肝纤维化中起关键作用。因为这些细胞表达结蛋白和平滑肌α-肌动蛋白，所以它们被认为是肌源性的。当发现星形细胞也表达胶质细胞酸性蛋白和神经细胞粘附分子时，这一假说受到了质疑。在本研究中，我们发现，活化的星状细胞表达巢蛋白，VI类中间丝蛋白最初被确定为神经干细胞的标志物。巢蛋白的表达首先在培养的星状细胞自发激活过程中进行了研究。免疫组化显示，巢蛋白阳性的星状细胞已经出现在第3天，几乎所有的细胞成为阳性巢蛋白在第6和15天。除分裂细胞外，免疫反应呈细丝状。逆转录聚合酶链反应和扩增的互补DNA测序显示巢蛋白的信使RNA转录本的存在。然后，我们比较了巢蛋白与其他中间丝蛋白和平滑肌α-肌动蛋白的存在，免疫印迹显示，巢蛋白，结蛋白，波形蛋白的相对浓度增加之间的第2天和第6天的原代培养。在最初的增加后，波形蛋白趋于平稳，而巢蛋白和结蛋白则呈下降趋势。这种模式是完全不同的胶质细胞酸性蛋白，不断下降，平滑肌α-肌动蛋白，不断增加，直到第13天的文化。然后，我们研究了巢蛋白在正常和四氯化碳损伤大鼠肝脏的存在。在正常肝脏中，巢蛋白的免疫反应最小的肝实质内观察。在四氯化碳诱导纤维化过程中，nestin阳性星状细胞在6周时出现，与结蛋白和平滑肌α-肌动蛋白的诱导相比，这是晚的。我们的结论是，巢蛋白诱导的星形细胞从静止到激活的表型过渡期间，培养激活是一个更强的刺激比在体内激活注射四氯化碳。结合星状细胞表达胶质细胞酸性蛋白和神经细胞粘附分子的报道，需要对这些细胞的胚胎起源进行新的实验研究。
Hepatic stellate cells are considered to be liver-specific pericytes that play a key role in liver fibrosis. Because these cells express desmin and smooth muscle alpha-actin, they were assumed to be of myogenic origin. This hypothesis became doubtful when it was reported that stellate cells also express glial fibrillary acidic protein and neural cell adhesion molecule. In the present study, we show that activated stellate cells express nestin, a class VI intermediate filament protein originally identified as a marker for neural stem cells. Expression of nestin was first studied during spontaneous activation of stellate cells in culture. Immunohistochemistry showed that nestin-positive stellate cells already appeared at day 3, and nearly all the cells became positive for nestin at day 6 and 15. The immunoreaction was present in filaments except in dividing cells. The presence of messenger RNA transcript for nestin was shown by reverse transcription polymerase chain reaction and sequencing of amplified complementary DNA. We then compared the presence of nestin with that of other intermediate filament proteins and smooth muscle alpha-actin, Immunoblotting showed that the relative concentrations of nestin, desmin, and vimentin increased between day 2 and 6 in primary culture. After the initial increase vimentin leveled off, while nestin and desmin showed a tendency to decrease. This pattern was quite different from that of glial fibrillary acidic protein, which kept declining, and smooth muscle alpha-actin, which increased continuously up to day 13 in culture. We then studied the presence of nestin in normal and CCl4-injured rat liver. In normal liver, minimal immunoreaction for nestin was observed within the liver parenchyma. During induction of fibrosis by carbon tetrachloride, nestin-positive stellate cells appeared at 6 weeks, which was late in comparison with the induction of desmin and smooth muscle alpha-actin. We conclude that nestin is induced in stellate cells during transition from the quiescent to the activated phenotype; culture activation is a stronger stimulus than in vivo activation by injection of CCl4. Taken together with reports on expression of glial fibrillary acidic protein and neural cell adhesion molecule by stellate cells, new experimental studies on the embryonic origin of these cells are required.