Chen Feng, Zhang Shaohui, Liu Tinghong, Yuan Liu, Wang Yangshuo, Zhang Guojun, Liang Shuli
Functional Neurosurgery Department, National Children's Health Center of China, Beijing Children's Hospital, Capital Medical University, No. 56, Nanlishi Road, Xicheng District, Beijing, 100045, China.
Neurosurgery Department, PLA General Hospital, No. 28 Fuxing Road, Haidian District, Beijing, 100853, China.
Transl Neurosci. 2022 Jun 9;13(1):125-133. doi: 10.1515/tnsci-2022-0222. eCollection 2022 Jan 1.
The first Chinese family with paroxysmal non-kinesigenic dystonia (PNKD) was confirmed to harbour a mutation. However, the pathogenic mechanism of the PNKD-causing gene mutation was unclear.
Wild-type and mutant plasmids were prepared and transfected into the C6 cell line to study the distribution and stability of PNKD protein in C6 cells and its effect on the glutathione content. The blood and cerebrospinal fluid (CSF) of 3 PNKD patients and 3 healthy controls were collected. The differentially expressed proteins were identified using isobaric tags for relative and absolute quantitation. Furthermore, Gene Ontology (GO) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) enrichment analyses were performed, and the protein-protein interaction network was constructed.
Wild-type PNKD protein was mainly distributed in the membranes, whereas mutant PNKD protein was distributed throughout the C6 cells. After transfection with mutant plasmid, the glutathione content decreased significantly in C6 cells; the stability of the mutant PNKD protein was significantly low. There were 172 and 163 differentially expressed proteins in CSF and plasma, respectively, of PNKD patients and healthy controls. For these proteins, blood microparticle and complex activation (classical pathway) were the common GO enrichment term, and complex and coordination cascade pathway were the common KEGG enrichment pathway. Recombinant mothers against decapentaplegic homolog 4 (SMAD4) was one of the differentially expressed proteins; it exhibited a relationship with the aforementioned enrichment GO terms and KEGG pathway.
PNKD protein was mainly distributed in cell membranes. mutation affected subcellular localisation, PNKD protein stability, and glutathione content. SMAD4 was found to be a potential biomarker for PNKD diagnosis.
首个确诊携带突变的阵发性非运动诱发性肌张力障碍（PNKD）中国家系被证实。然而，导致PNKD的基因突变的致病机制尚不清楚。
制备野生型和突变型质粒并转染至C6细胞系，以研究PNKD蛋白在C6细胞中的分布和稳定性及其对谷胱甘肽含量的影响。收集3例PNKD患者和3名健康对照者的血液和脑脊液（CSF）。使用相对和绝对定量的等压标签鉴定差异表达的蛋白质。此外，进行基因本体论（GO）和京都基因与基因组百科全书（KEGG）富集分析，并构建蛋白质-蛋白质相互作用网络。
野生型PNKD蛋白主要分布在细胞膜中，而突变型PNKD蛋白则分布于整个C6细胞。用突变型质粒转染后，C6细胞中的谷胱甘肽含量显著降低；突变型PNKD蛋白的稳定性显著降低。PNKD患者和健康对照者的脑脊液和血浆中分别有172种和163种差异表达蛋白。对于这些蛋白，血液微粒和补体激活（经典途径）是常见的GO富集术语，补体和协调级联途径是常见的KEGG富集途径。重组的果蝇母亲抗五体不全同源蛋白4（SMAD4）是差异表达蛋白之一；它与上述富集的GO术语和KEGG途径存在关联。
PNKD蛋白主要分布在细胞膜中。突变影响亚细胞定位、PNKD蛋白稳定性和谷胱甘肽含量。发现SMAD4是PNKD诊断的潜在生物标志物。
