S100B is expressed in, and released from, OLN-93 oligodendrocytes: Influence of serum and glucose deprivation
S100B is expressed in, and released from, OLN-93 oligodendrocytes: Influence of serum and glucose deprivation
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DOI：
10.1016/j.neuroscience.2008.03.060
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发表时间：
2008-06
期刊：
影响因子：
3.3
通讯作者：
Johann Steiner;H. Bernstein;B. Bogerts;T. Gos;C. Richter-Landsberg;M. Wunderlich;G. Keilhoff
中科院分区：
文献类型：
--
作者：
Johann Steiner;H. Bernstein;B. Bogerts;T. Gos;C. Richter-Landsberg;M. Wunderlich;G. Keilhoff
S100B(在中性pH条件下100%溶于硫酸铵的蛋白质家族成员)已被广泛用作动物模型和人脑疾病的星形胶质细胞标记物。最近的研究发现，S100B免疫阳性在少突胶质细胞和O2A少突胶质前体细胞中呈阳性。然而，目前尚不清楚是少突胶质细胞自己产生S100B，还是S100B免疫标记是由蛋白质的结合或吸收引起的。为了解决这个问题，我们分析了S100B在一个高纯度的少突胶质细胞OLN-93细胞系(大鼠)、星形胶质细胞C6细胞系(大鼠)和原代星形胶质细胞中的表达和蛋白释放。逆转录聚合酶链式反应(RT-PCR)分析表明，S100B在所有培养物中均有基因表达。OLN-93细胞和胶质纤维酸性蛋白(GFAP)阴性的星形胶质细胞表达晚期糖基化终产物多配体受体(RAGE)。用免疫发光法测定正常条件下、血清和葡萄糖剥夺(SGD)后培养上清液和细胞匀浆中S100B蛋白的水平。SGD导致S100B的释放增加数倍(6和24小时后)，这在原代星形胶质细胞中尤为明显。在SGD作用下，OLN-93细胞S100B含量增加最为显著，说明S100B合成被激活。在SGD后，这些细胞也显示出最高的死亡细胞百分比，这是由碘化丙啶阳性确定的。外源性S100B与0.5、2和5μg/L共同孵育对OLN-93细胞无毒性作用。综上所述，OLN-93细胞在SGD作用下比星形胶质细胞产生更多的S100B，并且在SGD时更容易发生细胞死亡，从而引起S100B的泄漏。我们的数据表明星形胶质细胞在SGD下分泌S100B是活跃的，因为在上清中检测到高度升高的S100B水平，尽管死亡细胞的比例很低。实验结果为在少突胶质细胞中/从少突胶质细胞中产生/释放S100B提供了进一步的证据，例如在脑缺血等代谢应激条件下。体液中S100B的研究应仔细解释，以避免误导关于星形胶质细胞特定参与的假说，因为S100B的细胞来源多种多样。
S100B (member of a family of proteins that are 100% soluble in ammonium sulfate at neutral pH) has been widely used as astrocyte marker in animal models and in human brain diseases. Recent studies revealed S100B-immunopositivity in oligodendrocytes and O2A oligodendroglial progenitor cells. It is unknown, however, if oligodendrocytes produce S100B themselves, or if the S100B-immunolabeling is caused by binding or absorption of the protein. To address this question, S100B expression and protein release were analyzed in a highly pure oligodendrocytic OLN-93 cell line (from rat), in the astrocytic C6 cell line (from rat) and primary astrocytes. S100B was gene expressed in all cultures, as revealed by reverse transcriptase polymerase chain reaction (RT-PCR) analysis. OLN-93 cells and glial fibrillary acidic protein (GFAP)-negative astrocytes expressed the multiligand receptor for advanced glycation end products (RAGE). S100B protein levels were determined in supernatants and cell homogenates by immunoluminometry under normal conditions and after serum and glucose deprivation (SGD). SGD led to a several-fold increased release of S100B (after 6 and 24 h), which was particularly pronounced in primary astrocytes. Increased S100B in cell homogenates was most notable in OLN-93 cells under SGD, indicating activated S100B synthesis. These cells also showed the highest percentage of dead cells, as determined by propidium iodide-positivity, after SGD. Incubation with 0.5, 2 and 5 μg/l exogenous S100B was not toxic to OLN-93 cells. In conclusion, OLN-93 cells produce more S100B under SGD than astrocytes and are more susceptible to cell death upon SGD, which provokes leakage of S100B. Our data indicate active S100B secretion from astrocytes under SGD since highly elevated levels of S100B were detected in the supernatant despite a low percentage of dead cells. The experimental results provide further evidence for a production/release of S100B in/from oligodendrocytes, e.g. in metabolic stress conditions like cerebral ischemia. Studies on S100B in bodily fluids should be carefully interpreted in order to avoid misleading hypotheses concerning the specific involvement of astrocytes, due to the various cellular sources of S100B.