儿童表皮葡萄球菌脑膜炎脑脊液蛋白质组学的初步研究

A pilot study on the proteome of cerebrospinal fluid of Staphylococcus epidermidis meningitis in children

目的细菌性脑膜炎是致残、致死率较高的儿童时期常见中枢神经系统感染性疾病,其预后与诊断时间的早晚、是否及时治疗密切相关。而目前脑脊液(cerebrospinal fluid,CSF)中细菌培养的阳性率较低,使其确诊困难。该实验拟通过建立正常中国儿童CSF蛋白质双向凝胶电泳图谱,筛选表皮葡萄球菌脑膜炎(Staphylococ-cus epidermidis meningitis,SeM)特异性蛋白,为SeM的早期诊断提供线索,同时也为进一步治疗提供靶参考。方法收集SeM患儿和同年龄正常儿童CSF各4mL,固相pH梯度二维聚丙烯酰胺凝胶电泳(2-DE)技术分离蛋白质,以正常儿童CSF的2-DE凝胶为参考胶,将SeM患儿CSF的凝胶与之进行比较分析,寻找两组患儿CSF蛋白质谱的异常变化斑点。结果正常儿童CSF分离获得蛋白质斑点438个,SeM患儿CSF分离获得蛋白质斑点425个,其中发现有25个蛋白质点仅在正常CSF表达,在SeM CSF中表达而在正常CSF中无表达的蛋白质点为12个;与正常CSF蛋白质点表达量比较,SeM有6个蛋白质点表达量有2倍以上上调,而19个蛋白质点表达量有2倍以上下调。结论该实验成功建立了正常儿童和SeM患儿CSF蛋白质2-DE图谱,通过凝胶图像分析和计算机信息处理,发现了一些与SeM相关的蛋白质差异位点。对这些差异位点的进一步分析和鉴定,可能有助于发现与SeM相关的疾病特异性蛋白,为早期诊断及寻找新的药物靶点提供了新的思路。

Objective Bacterial meningitis is a kind of central nervous system infection with a high incidence, disability and fatality in children. Prompt diagnosis and treatment are associated with an improved prognosis. Low positive rate of bacterial cultures of the cerebrospinal fluid （CSF） makes it difficult to make a definite diagnosis. This experiment aimed to investigate a proteome profile of normal CSF of Chinese children by two-dimensional polyacrydamide gel electrophoresis （2-DE）, and to sieve the disease-specific proteins of Staphylococcus epidermidis meningitis （ SeM ） to provide basis for early diagnosis and treatment of SeM. Methods Four mL CSF samples were obtained respectively from SeM and normal children. The separated proteins with immobile pH gradient （IPG） 2-DE technology and protein spots were visualized by Coomassie Brilliant Blue staining. The stained 2-DE gels were scanned on the Imagescanner and pictures were obtained through Labscan software. The images were analyzed with PDQuest software and the differences of protein spots were compared between the SeM and normal children. Results Mean protein spots of the 2-DE gels were 438 and 425 in the SeM and normal groups respectively. Twenty-five protein spots only occurred in normal CSF and 12 spots only occurred in the SeM group. The expression of 6 protein spots showed up-regulation and that of 19 showed down-regulation in the SeM group compared with that in the normal group. Conclusions A 2-DE profile of CSF proteome was successfully established in SeM and normal children through proteomic technique. By the differentiated analysis of these CSF 2-DE gels, the differences of CSF proteome profiles were found between SeM and normal children. Future analysis and identification of these spots will contribute to find out the disease specific proteins of SeM and to provide basis for early diagnosis and therapy of this disorder.