Department of Neuroscience, Uppsala University, Uppsala, Sweden.
PLoS One. 2013;8(2):e55983. doi: 10.1371/journal.pone.0055983. Epub 2013 Feb 7.
The complicated secondary molecular and cellular mechanisms following traumatic brain injury (TBI) are still not fully understood. In the present study, we have used mass spectrometry to identify injury specific proteins in an in vitro model of TBI. A standardized injury was induced by scalpel cuts through a mixed cell culture of astrocytes, oligodendrocytes and neurons. Twenty-four hours after the injury, cell culture medium and whole-cell fractions were collected for analysis. We found 53 medium proteins and 46 cell fraction proteins that were specifically expressed after injury and the known function of these proteins was elucidated by an extensive literature survey. By using time-lapse microscopy and immunostainings we could link a large proportion of the proteins to specific cellular processes that occur in response to trauma; including cell death, proliferation, lamellipodia formation, axonal regeneration, actin remodeling, migration and inflammation. A high percentage of the proteins uniquely expressed in the medium after injury were actin-related proteins, which normally are situated intracellularly. We show that two of these, ezrin and moesin, are expressed by astrocytes both in the cell culture model and in mouse brain subjected to experimental TBI. Interestingly, we found many inflammation-related proteins, despite the fact that cells were present in the culture. This study contributes with important knowledge about the cellular responses after trauma and identifies several potential cell-specific biomarkers.
颅脑损伤（TBI）后复杂的次级分子和细胞机制仍未完全阐明。在本研究中，我们使用质谱分析法在 TBI 的体外模型中鉴定了损伤特异性蛋白。通过手术刀切割培养的星形胶质细胞、少突胶质细胞和神经元混合物来诱导标准化损伤。损伤后 24 小时，收集细胞培养液和全细胞级分进行分析。我们发现 53 种培养基蛋白和 46 种细胞级分蛋白在损伤后特异性表达，通过广泛的文献调查阐明了这些蛋白的已知功能。通过使用延时显微镜和免疫染色，我们可以将很大一部分蛋白与创伤后发生的特定细胞过程联系起来，包括细胞死亡、增殖、片状伪足形成、轴突再生、肌动蛋白重塑、迁移和炎症。损伤后培养基中特异性表达的蛋白中有很大一部分与肌动蛋白有关，这些蛋白通常位于细胞内。我们发现其中两种蛋白，埃兹蛋白和膜突蛋白，在细胞培养模型和实验性 TBI 小鼠脑中的星形胶质细胞中均有表达。有趣的是，尽管细胞存在于培养物中，但我们发现了许多炎症相关蛋白。这项研究为创伤后的细胞反应提供了重要的知识，并确定了几个潜在的细胞特异性生物标志物。
