Double-labeling correlative light and electron microscopy and its application to neurodengeration

2019 Fiscal Year Final Research Report

• Project/Area Number: 16K14572
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Nerve anatomy/Neuropathology
• Research Institution: Tokyo Medical and Dental University (2018-2019); Tokyo Metropolitan Institute of Medical Science (2016-2017)
• Principal Investigator: Uchihara Toshiki 東京医科歯科大学, 大学院医歯学総合研究科, 特任教授 (10223570)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: 電子顕微鏡 / 二重免疫染色 / タウ / アルツハイマー病 / 神経原線維変化

Outline of Final Research Achievements

Brain lesions in neurodegenerative disorders are composed of fibrillary structures, which are composed of different molecules. Quantum dots are electron dense nanocrystals that emit fluorescence, hense permit dual detection (fluorescence and electron microscopy) of the same target, when used in immunolabeling. Even after gold enhancement, it was possible to distinguish different QDs, each labeling respective epitopes. This is the first successful application of double-labelling correlative light and electron microscopy to autopsied human brain samples. Double labeling of neurofibrillary tangles for three-repeat (3R) and four-repeat (4R) tau demonstrated that ultrastructure of 4R-positive fibers is distinct from that of 3R-positive-fibers.

Free Research Field

神経病理学

Academic Significance and Societal Importance of the Research Achievements

アルツハイマー病（AD)脳で認知障害の程度に関連する病変は、タウ蛋白からなる神経原線維変化（NFT)とされるが実態は3リピート(3R), 4リピート(4R)の2種類のタウが関与している。3R, 4RタウはNFTの異なる線維成分を構成していることを、今回開発した二重免疫電顕法をヒト剖検脳に応用して、世界で初めて示した。タウ蛋白と一括してきた従来の診断、治療戦略ではこうした複数のタウ分子が関与する病態をとらえて診断・治療することはできず、診断・治療戦略を根本的に見直す必要を本研究は示唆する。