Department of Radiology, Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown , Massachusetts 02129 , United States.
Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown , Massachusetts 02129 , United States.
ACS Chem Neurosci. 2018 Nov 21;9(11):2563-2571. doi: 10.1021/acschemneuro.8b00072. Epub 2018 May 17.
Huntington's disease is a devastating neurodegenerative genetic disorder that causes progressive motor dysfunction, emotional disturbances, and cognitive impairment. Unfortunately, there is no treatment to cure or slow the progression of the disease. Neuroinflammation is one hallmark of Huntington's disease, and modulation of neuroinflammation has been suggested as a potential target for therapeutic intervention. The relationship between neuroinflammation markers and the disease pathology is still poorly understood. To improve our understanding of neuroinflammation in Huntington's disease, we measured translocator protein (TSPO) expression using C-PBR28 and simultaneous PET/MRI. Standardized-uptake-value ratios, normalized by whole brain uptake, were calculated for data acquired 60-90 min after radiotracer administration. We identified distinct patterns of regional neuroinflammation (as defined by TSPO overexpression relative to a control group) in the basal ganglia of Huntington's disease patients. These patterns were observed at the individual level in all patients, with region of interest analysis confirming significant differences between patients and the control group in the putamen and the pallidum. Additionally, we observed further distinct regional and subregional signatures, which may provide insights into phenotypical variability. For example, in certain Huntington's disease patients, we observed in vivo elevation of the level of TSPO binding in subnuclei in the thalamus and brainstem that have been previously associated with visual function, motor function, and motor coordination. Our main result is an objective score, based solely on C-PBR28 measurements, that correlates well with measurements of brain atrophy. We conclude that PET/MR imaging using C-PBR28 provides a high signal-to-background ratio and has the potential to be used to assess Huntington's disease progression. Our results suggest C-PBR28 might prove useful in clinical trials evaluating therapies targeting neuroinflammation.
亨廷顿病是一种破坏性的神经退行性遗传疾病,导致进行性运动功能障碍、情绪障碍和认知障碍。不幸的是,目前尚无治疗方法可以治愈或减缓疾病的进展。神经炎症是亨廷顿病的一个标志特征,调节神经炎症已被认为是治疗干预的潜在靶点。神经炎症标志物与疾病病理之间的关系仍知之甚少。为了更好地了解亨廷顿病中的神经炎症,我们使用 C-PBR28 并同时进行 PET/MRI 来测量转位蛋白 (TSPO) 的表达。通过放射性示踪剂给药后 60-90 分钟获得的数据,计算标准化摄取值比值,通过全脑摄取进行归一化。我们在亨廷顿病患者的基底神经节中发现了与对照组相比 TSPO 过度表达的区域神经炎症(定义为)的不同模式。在所有患者中都在个体水平上观察到了这些模式,并且在纹状体和苍白球中,对感兴趣区域的分析证实了患者与对照组之间的显著差异。此外,我们还观察到了进一步的不同的区域和亚区域特征,这可能为表型变异性提供了一些见解。例如,在某些亨廷顿病患者中,我们观察到在体内与视觉功能、运动功能和运动协调相关的丘脑和脑干的亚核中 TSPO 结合水平升高。我们的主要结果是一个客观评分,仅基于 C-PBR28 的测量值,与脑萎缩的测量值密切相关。我们得出的结论是,使用 C-PBR28 的 PET/MR 成像提供了高的信噪比,并且有可能用于评估亨廷顿病的进展。我们的结果表明,C-PBR28 可能在评估针对神经炎症的治疗方法的临床试验中证明有用。