Department of Neurology, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, the Netherlands.
Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands.
Clin Chem. 2019 Oct;65(10):1295-1306. doi: 10.1373/clinchem.2019.305391. Epub 2019 Aug 2.
Many muscular dystrophies currently remain untreatable. Recently, dietary ribitol has been suggested as a treatment for cytidine diphosphate (CDP)-l-ribitol pyrophosphorylase A (CRPPA, ISPD), fukutin (FKTN), and fukutin-related protein (FKRP) myopathy, by raising CDP-ribitol concentrations. Thus, to facilitate fast diagnosis, treatment development, and treatment monitoring, sensitive detection of CDP-ribitol is required.
An LC-MS method was optimized for CDP-ribitol in human and mice cells and tissues.
CDP-ribitol, the product of CRPPA, was detected in all major human and mouse tissues. Moreover, CDP-ribitol concentrations were reduced in fibroblasts and skeletal muscle biopsies from patients with CRPPA myopathy, showing that CDP-ribitol could serve as a diagnostic marker to identify patients with CRPPA with severe Walker-Warburg syndrome and mild limb-girdle muscular dystrophy (LGMD) phenotypes. A screen for potentially therapeutic monosaccharides revealed that ribose, in addition to ribitol, restored CDP-ribitol concentrations and the associated O-glycosylation defect of α-dystroglycan. As the effect occurred in a mutation-dependent manner, we established a CDP-ribitol blood test to facilitate diagnosis and predict individualized treatment response. Ex vivo incubation of blood cells with ribose or ribitol restored CDP-ribitol concentrations in a patient with CRPPA LGMD.
Sensitive detection of CDP-ribitol with LC-MS allows fast diagnosis of patients with severe and mild CRPPA myopathy. Ribose offers a readily testable dietary therapy for CRPPA myopathy, with possible applicability for patients with FKRP and FKTN myopathy. Evaluation of CDP-ribitol in blood is a promising tool for the evaluation and monitoring of dietary therapies for CRPPA myopathy in a patient-specific manner.
目前，许多肌肉疾病仍然无法治疗。最近，饮食中的赤藓糖醇被认为可以通过提高 CDP-核糖醇浓度来治疗胞苷二磷酸（CDP）-L-核糖醇焦磷酸化酶 A（CRPPA、ISPD）、福ukin（FKTN）和福ukin 相关蛋白（FKRP）肌病。因此，为了便于快速诊断、治疗开发和治疗监测，需要对 CDP-核糖醇进行敏感检测。
优化了用于人源和鼠源细胞及组织中 CDP-核糖醇的 LC-MS 方法。
CRPPA 的产物 CDP-核糖醇在所有主要的人类和鼠类组织中均有检测到。此外，CRPPA 肌病患者的成纤维细胞和骨骼肌活检组织中 CDP-核糖醇浓度降低，表明 CDP-核糖醇可作为一种诊断标志物，用于识别严重 Walker-Warburg 综合征和轻度肢带型肌营养不良症（LGMD）表型的 CRPPA 患者。对潜在治疗性单糖的筛选表明，除了核糖醇之外，核糖还可以恢复 CDP-核糖醇浓度和 α- dystroglycan 的相关 O-糖基化缺陷。由于这种作用以突变依赖的方式发生，我们建立了 CDP-核糖醇血液检测方法，以促进诊断并预测个体化的治疗反应。将患者的血细胞在体外与核糖或赤藓糖醇孵育可恢复 CRPPA LGMD 患者的 CDP-核糖醇浓度。
用 LC-MS 对 CDP-核糖醇进行灵敏检测可快速诊断严重和轻度 CRPPA 肌病患者。核糖醇为 CRPPA 肌病提供了一种易于检测的饮食疗法，可能适用于 FKRP 和 FKTN 肌病患者。评估血液中的 CDP-核糖醇是一种有前途的工具，可用于以患者特异性的方式评估和监测 CRPPA 肌病的饮食治疗。
