Revelation of the distribution of scrapie prion protein of non-central nervous tissues in prion diseases

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K16183
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 49020:Human pathology-related
• Research Institution: Aichi Medical University
• Principal Investigator: Akagi Akio 愛知医科大学, 加齢医科学研究所, 講師 (10804239)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: プリオン病 / プリオン仮説 / 非中枢性組織

Outline of Final Research Achievements

In prion diseases, scrapie prion protein (PrPSc) is deposited diffusely throughout the cerebral cortex from an early onset. This study examined the localization of PrPSc in the trigeminal ganglia of non-central nervous tissues to elucidate the route and propagation mode of PrPSc. Eighteen cases of prion diseases were analyzed. Vacuole formation was observed within the neuronal body of the trigeminal ganglion; however, no PrPSc deposition was observed. Conversely, PrPSc deposition was observed in the nerve fibers of the trigeminal ganglion. The study results suggest that PrPSc in the body propagates through the trigeminal nerve fibers and spreads to non-central nervous tissues. We will continue to perform autopsies and analyses of prion diseases, including non-central nervous tissues, to elucidate the route and propagation mode of PrPSc.

Free Research Field

神経病理学

Academic Significance and Societal Importance of the Research Achievements

異常プリオン蛋白（PrP）が体内に侵入すると、正常PrPが構造変化を起こし異常PrPに変換される (感染性を有するようになる) 。このように蛋白のみで疾患が伝播されることをプリオン仮説と呼ぶ。近年、アルツハイマー病やパーキンソン病でもプリオン仮説が起こり、異常蛋白の分布や広がりが臨床症状と密接に関連し、特定の決まったパターンで空間的に進展することが報告されている。
本研究で、三叉神経線維に沿った異常PrPの沈着を認めた。異常PrPは中枢組織から神経線維を通じて、非中枢神経組織へ拡がっている可能性が示唆される。異常PrPの体内での伝播経路を考える上で貴重な所見を得た。