Acta Neuropathologica

, Volume 120, Issue 2, pp 145–154

Proteinase K-resistant α-synuclein is deposited in presynapses in human Lewy body disease and A53T α-synuclein transgenic mice

  • Kunikazu Tanji
  • Fumiaki Mori
  • Junsei Mimura
  • Ken Itoh
  • Akiyoshi Kakita
  • Hitoshi Takahashi
  • Koichi Wakabayashi
Original Paper

DOI: 10.1007/s00401-010-0676-z

Cite this article as:
Tanji, K., Mori, F., Mimura, J. et al. Acta Neuropathol (2010) 120: 145. doi:10.1007/s00401-010-0676-z

Abstract

Abnormally modified α-synuclein is a pathological hallmark of Parkinson’s disease and the other α-synucleinopathies. Since proteinase K (PK) treatment is known to enhance the immunoreactivity of abnormal α-synuclein, we immunohistochemically examined the brain of transgenic (Tg) mice expressing human mutant A53T α-synuclein using this retrieval method. PK treatment abolished the immunoreactivity of α-synuclein in abnormal inclusions as well as of endogenous α-synuclein in Tg mice, whereas PK-resistant α-synuclein was found in the presynaptic nerve terminals, especially in the hippocampus and temporal cortex. In human Lewy body disease, PK-resistant α-synuclein was deposited in Lewy bodies and Lewy neurites, as well as in the presynapses in distinct brain regions, including the hippocampus, temporal cortex and substantia nigra. Biochemical analysis revealed that PK-resistant α-synuclein was detected in the presynaptic fraction in Tg mice and human Lewy body disease. Although PK-resistant α-synuclein was found in the presynapse in Tg mice even at 1 week of age, it was not phosphorylated until at least 8 months of age. Moreover, PK-resistant α-synuclein in the presynapse was not phosphorylated in human Lewy body disease. These findings suggest that phosphorylation is not necessary to cause the conversion of soluble form to PK-resistant α-synuclein. Considering that native α-synuclein is a soluble protein localized to the presynaptic terminals, our findings suggest that PK-resistant α-synuclein may disturb the neurotransmission in α-synucleinopathies.

Keywords

α-Synuclein Dementia with Lewy bodies Parkinson’s disease Presynapse Proteinase K Transgenic mice 

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  • Kunikazu Tanji
    • 1
  • Fumiaki Mori
    • 1
  • Junsei Mimura
    • 2
  • Ken Itoh
    • 2
  • Akiyoshi Kakita
    • 3
  • Hitoshi Takahashi
    • 4
  • Koichi Wakabayashi
    • 1
  1. 1.Department of Neuropathology, Institute of Brain ScienceHirosaki University Graduate School of MedicineHirosakiJapan
  2. 2.Department of Stress Response ScienceHirosaki University Graduate School of MedicineHirosakiJapan
  3. 3.Department of Pathological Neuroscience, Center for Bioresource-based ResearchesUniversity of NiigataNiigataJapan
  4. 4.Department of Pathology, Brain Research InstituteUniversity of NiigataNiigataJapan

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