Heterogeneity of nigral and cortical Lewy bodies differentiated by amplified triple-labeling for alpha-synuclein, ubiquitin, and thiazin red.

Alpha-synuclein(alpha-S) and ubiquitin(Ub) are constituents of the Lewy bodies (LBs), composed of fibrillary structures. To clarify morphological heterogeneity of LBs, we looked for localization of these epitopes in relation to fibrillary structure possibly detectable by a fluorochrome, thiazin red (TR). On the sections of the substantia nigra (SN) and the cingulate gyrus (CG) obtained from Parkinson's disease brains, double amplification by CARD fluorescent immunohistochemistry with anti-alpha-S monoclonal (LB509) and anti-Ub polyclonal antibodies was performed, followed by staining with TR. These triple-labeled images were captured by a confocal laser microscope and subsequently stained with Campbell-Switzer method, a silver staining specific for LBs. Staining profiles of LBs were different between those in the SN and in the CG. Immunolabeling either with the anti-alpha-S or anti-Ub antibody was diffuse without halo structure in LBs of CG. In addition to this diffuse staining, a lot of LBs of SN exhibited a halo structure immunopositive for alpha-S and Ub, probably representing later stages of LB evolution. Irrespective of the presence of this halo structure, the TR signal was always concentrated in the center of LBs, as the silver-stained material was, suggesting that fibrillary components in the central portion of LBs undergo some conformational changes detectable by TR and the silver-staining. This technique reveals different epitopes in relation to LB evolution in vivo. Heterogeneity in staining profile of LBs, as clarified by this method, may represent evolutional changes of LBs, related to conformational states of their constituents.