Imbault Virginie, Dionisi Chiara, Naeije Gilles, Communi David, Pandolfo Massimo
Mass Spectrometry and Proteomics Laboratory/Platform, Institut de Recherche en Biologie Humaine et Moléculaire (IRIBHM), Université Libre de Bruxelles, Brussels, Belgium.
Laboratory of Experimental Neurology, Université Libre de Bruxelles, Brussels, Belgium.
Front Neurosci. 2022 Jul 13;16:885313. doi: 10.3389/fnins.2022.885313. eCollection 2022.
Clinical trials in rare diseases as Friedreich ataxia (FRDA) offer special challenges, particularly when multiple treatments become ready for clinical testing. Regulatory health authorities have developed specific pathways for "orphan" drugs allowing the use of a validated biomarker for initial approval. This study aimed to identify changes in cerebrospinal fluid (CSF) proteins occurring in FRDA patients that may be potential biomarkers in therapeutic trials. CSF was obtained from 5 FRDA patients (4 females, 1 male) from the Brussels site of the European Friedreich Ataxia Consortium for Translational Studies (EFACTS). Two patients were ambulatory, three used a wheelchair. Residual CSF samples from 19 patients who had had a lumbar puncture as part of a diagnostic workup were used as controls. All CSF samples had normal cells, total protein and glucose levels. Proteins were identified by label-free data-dependent acquisition mass spectrometry (MS) coupled to micro-high performance liquid chromatography. We found 172 differentially expressed proteins (DEPs) (92 up, 80 down) between FRDA patients and controls at < 0.05, 34 DEPs (28 up, 6 down) at < 0.0001. Remarkably, there was no overlap between FRDA patients and controls for seven upregulated and six downregulated DEPs. Represented pathways included extracellular matrix organization, signaling, the complement cascade, adhesion molecules, synaptic proteins, neurexins and neuroligins. This study supports the hypothesis that the quantitative analysis CSF proteins may provide robust biomarkers for clinical trials as well as shed light on pathogenic mechanisms. Interestingly, DEPs in FA patients CSF point to neurodegeneration and neuroinflammation processes that may respond to treatment.
针对诸如弗里德赖希共济失调（FRDA）等罕见病的临床试验面临特殊挑战，尤其是当多种治疗方法准备好进行临床测试时。监管卫生当局已为“孤儿”药物制定了特定途径，允许使用经过验证的生物标志物进行初步批准。本研究旨在确定FRDA患者脑脊液（CSF）蛋白质中发生的变化，这些变化可能是治疗试验中的潜在生物标志物。脑脊液取自欧洲弗里德赖希共济失调转化研究联盟（EFACTS）布鲁塞尔站点的5名FRDA患者（4名女性，1名男性）。两名患者可独立行走，三名患者使用轮椅。将19名作为诊断检查一部分进行了腰椎穿刺的患者的剩余脑脊液样本用作对照。所有脑脊液样本的细胞、总蛋白和葡萄糖水平均正常。通过与微高效液相色谱联用的无标记数据依赖型采集质谱（MS）鉴定蛋白质。我们发现，在FRDA患者和对照组之间，有172种差异表达蛋白（DEP）（92种上调，80种下调），P<0.05；34种DEP（28种上调，6种下调），P<0.0001。值得注意的是，7种上调和6种下调的DEP在FRDA患者和对照组之间没有重叠。所代表的途径包括细胞外基质组织、信号传导、补体级联、黏附分子、突触蛋白、神经连接蛋白和神经配体。本研究支持这样一种假设，即脑脊液蛋白质的定量分析可能为临床试验提供可靠的生物标志物，并有助于阐明致病机制。有趣的是，FA患者脑脊液中的DEP指向可能对治疗有反应的神经退行性变和神经炎症过程。
