Center for Neurodegenerative Disease Research and Institute on Aging, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA.
Department of Neurology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA.
Neuropathol Appl Neurobiol. 2017 Dec;43(7):604-620. doi: 10.1111/nan.12402. Epub 2017 May 15.
The aim of this study was to test the hypothesis that different conformations of misfolded α-synuclein (α-syn) are present in Parkinson's disease (PD) brain.
Using two previously characterized conformations of α-syn fibrils, we generated new conformation-selective α-syn monoclonal antibodies (mAbs). We then interrogated multiple brain regions in a well-characterized autopsy cohort of PD patients (n = 49) with these mAbs, Syn7015 and Syn9029.
Syn7015 detects Lewy bodies (LBs) and Lewy neurites (LNs) formed by pathological α-syn in all brain regions tested, and is particularly sensitive to LNs and small Lewy dots, inclusions believed to form early in the disease. Further, we observed colocalization between Syn7015 and an early marker of α-syn pathology formation, phospho-Ser129-α-syn, and a lack of extensive colocalization with markers of more mature pathology. In comparison, Syn9029 detects Lewy pathology in all regions examined, but indicates significantly fewer LNs than Syn7015. In addition, colocalization of Syn9029 with later markers of α-syn pathology maturation (ubiquitin and P62) suggests that the pathology detected by Syn9029 is older. Semiquantitative scoring of both LN and LB pathology in nine brain regions further established this trend, with Syn7015 LN scores consistently higher than Syn9029 LN scores.
Our data indicate that different conformations of α-syn pathology are present in PD brain and correspond to different stages of maturity for Lewy pathology. Regional analysis of Syn7015 and Syn9029 immunostaining also provides support for the Braak hypothesis that α-syn pathology advances through the brain.
本研究旨在验证假设，即帕金森病（PD）大脑中存在不同构象的错误折叠的α-突触核蛋白（α-syn）。
我们使用两种先前已鉴定的α-syn 纤维的构象，生成了新的构象选择性α-syn 单克隆抗体（mAb）。然后，我们使用这些 mAb（Syn7015 和 Syn9029）检测了具有良好特征的 PD 患者尸检队列的多个脑区（n=49）。
Syn7015 可检测到所有检测脑区中由病理性α-syn 形成的路易体（LB）和路易神经突（LN），对 LN 和小路易点（被认为是疾病早期形成的内含物）尤其敏感。此外，我们观察到 Syn7015 与α-syn 病理形成的早期标志物磷酸化-Ser129-α-syn 之间存在共定位，并且与更成熟的病理标志物之间不存在广泛的共定位。相比之下，Syn9029 可在所有检查区域检测到路易病变，但与 Syn7015 相比，指示的 LN 数量明显较少。此外，Syn9029 与α-syn 病理成熟的后期标志物（泛素和 P62）的共定位表明，Syn9029 检测到的病理更为陈旧。对九个脑区的 LN 和 LB 病理的半定量评分进一步证实了这一趋势，Syn7015 的 LN 评分始终高于 Syn9029 的 LN 评分。
我们的数据表明，PD 大脑中存在不同构象的α-syn 病理，并且与路易病理的不同成熟阶段相对应。Syn7015 和 Syn9029 免疫染色的区域分析也为 Braak 假说提供了支持，即α-syn 病理通过大脑进展。
