[Lewy body formation in Parkinson's disease: neurodegeneration or neuroprotection?].
The histological hallmark of Parkinson's disease (PD) is the presence of fibrillar aggregates called Lewy bodies (LBs). LB formation has been considered to be a marker for neuronal degeneration, because neuronal loss is found in the predilection sites for LBs. To date, more than 70 molecules have been identified in LBs, in which alpha-synuclein is a major constituent of LB fibrils. Alpha-synuclein immunohistochemistry reveals that diffuse cytoplasmic staining develops into pale bodies via compaction, and that LBs arise from the peripheral portion of pale bodies. Abnormal accumulation of alpha-synuclein (diffuse cytoplasmic staining, pale bodies and LBs) is found in 10% of pigmented neurons in the substantia nigra and more than 50% of those in the locus ceruleus in PD. Recent studies have suggested that oligomers and protofibrils of alpha-synuclein are cytotoxic, and that pale bodies and LBs may represent a cytoprotective mechanism in PD.
Wakabayashi
Koichi
K
Department of Neuropathology, Institute of Brain Science, Hirosaki University Graduate School of Medicine.
D003593:Cytoplasm / Q000378:metabolism; D006801:Humans; D016631:Lewy Bodies / Q000737:chemistry / Q000473:pathology*; D008125:Locus Coeruleus / Q000378:metabolism; D009410:Nerve Degeneration; D009474:Neurons / Q000378:metabolism; D010300:Parkinson Disease / Q000473:pathology*; D013378:Substantia Nigra / Q000378:metabolism; D051844:alpha-Synuclein / Q000378:metabolism
D051844:alpha-Synuclein