Institute of Biochemistry and Molecular Biology, School of Medicine, Shandong University, 44 Wenhuaxi Road, Jinan, Shandong 250012, People's Republic of China.
Mol Neurobiol. 2013 Jun;47(3):946-56. doi: 10.1007/s12035-012-8387-1. Epub 2013 Jan 22.
Multiple sclerosis is a neurological disorder that presents with symptoms including inflammation, neurodegeneration, and demyelination of the central nervous system (CNS). Secondary progressive multiple sclerosis (SPMS) manifests with serious physical disability. To quantitatively analyze differential protein expression in patients with SPMS, we performed two-dimensional fluorescence difference in-gel electrophoresis, followed by mass spectrometry on the cerebrospinal fluid of these patients and patients with other neurological diseases. Vitamin D-binding protein (DBP), gelsolin, albumin, etc. showed more than a 1.5-fold difference between the two groups. Based on these results, an experimental allergic encephalomyelitis (EAE) model of multiple sclerosis in Lewis rats was used to investigate DBP's role in the disease. Protein levels, mRNA transcripts, and ligands of DBP in different regions of the CNS were evaluated under various vitamin D intake levels. Here, DBP levels increased in the experimental rat groups compared to the control groups regardless of vitamin D intake. Moreover, DBP mRNA levels varied in different parts of the CNS including spinal cords in the experimental groups. The observed differences between DBP protein and mRNA levels in the experimental groups' spinal cords could be derived from the disruption of the blood-brain barrier. Furthermore, an interaction between DBP and actin was confirmed using coimmunoprecipitation and western blot. These results indicate a role for DBP in the actin scavenge system. Moreover, in the experimental group that received oral vitamin D3 supplement, we observed both delayed onset and diminished severity of the disease. When DBP was upregulated, however, the benefits from the vitamin D3 supplements were lost. Thus, we inferred that high levels of DBP were adverse to recovery. In conclusion, here we observed upregulated DBP in the cerebrospinal fluid could serve as a specific diagnostic biomarker for the progression of multiple sclerosis. Next, we demonstrate the vital function of increased levels of free vitamin D metabolites for multiple sclerosis treatment. Finally, vitamin D supplements may be particularly beneficial for SPMS patients.
多发性硬化症是一种神经系统疾病，其症状包括中枢神经系统（CNS）的炎症、神经退行性变和脱髓鞘。继发性进行性多发性硬化症（SPMS）表现为严重的身体残疾。为了定量分析 SPMS 患者的差异蛋白表达，我们对这些患者和其他神经疾病患者的脑脊液进行了二维荧光差异凝胶电泳，然后进行了质谱分析。维生素 D 结合蛋白（DBP）、凝胶素、白蛋白等在两组之间的差异超过 1.5 倍。基于这些结果，我们使用 Lewis 大鼠实验性变态反应性脑脊髓炎（EAE）多发性硬化症模型来研究 DBP 在疾病中的作用。在不同的维生素 D 摄入水平下，评估了 CNS 不同区域的 DBP 蛋白水平、mRNA 转录物和配体。在这里，无论维生素 D 的摄入如何，实验组大鼠的 DBP 水平都比对照组增加。此外，实验组 CNS 不同部位（包括脊髓）的 DBP mRNA 水平也存在差异。实验组脊髓中 DBP 蛋白和 mRNA 水平的观察差异可能源于血脑屏障的破坏。此外，还通过共免疫沉淀和 Western blot 证实了 DBP 与肌动蛋白之间的相互作用。这些结果表明 DBP 在肌动蛋白清除系统中起作用。此外，在接受口服维生素 D3 补充剂的实验组中，我们观察到疾病的发病时间延迟和严重程度减轻。然而，当 DBP 上调时，维生素 D3 补充剂的益处就消失了。因此，我们推断高水平的 DBP 不利于恢复。总之，在这里我们观察到脑脊液中上调的 DBP 可以作为多发性硬化症进展的特异性诊断生物标志物。接下来，我们证明了增加的游离维生素 D 代谢物水平对多发性硬化症治疗的重要作用。最后，维生素 D 补充剂可能对 SPMS 患者特别有益。
