Tissue Transglutaminase-Induced Aggregation of α-Synuclein: Implications for Lewy Body Formation in Parkinson's Disease and Dementia with Lewy Bodies
Proteinaceous aggregates containing α-synuclein represent a feature of neurodegenerative disorders such as Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy. Despite extensive research, the mechanisms underlying α-synuclein aggregation remain elusive. Previously, tissu...
Saved in:
Published in | Proceedings of the National Academy of Sciences - PNAS Vol. 100; no. 4; pp. 2047 - 2052 |
---|---|
Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
United States
National Academy of Sciences
18.02.2003
National Acad Sciences The National Academy of Sciences |
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | Proteinaceous aggregates containing α-synuclein represent a feature of neurodegenerative disorders such as Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy. Despite extensive research, the mechanisms underlying α-synuclein aggregation remain elusive. Previously, tissue transglutaminase (tTGase) was found to contribute to the generation of aggregates by cross-linking pathogenic substrate proteins in Huntington's and Alzheimer's diseases. In this article, the role of tTGase in the formation of α-synuclein aggregates was investigated. Purified tTGase catalyzed α-synuclein cross-linking, leading to the formation of high molecular weight aggregates in vitro, and overexpression of tTGase resulted in the formation of detergent-insoluble α-synuclein aggregates in cellular models. Immunocytochemical studies demonstrated the presence of α-synuclein-positive cytoplasmic inclusions in 8% of tTGase-expressing cells. The formation of these aggregates was significantly augmented by the calcium ionophore A23187 and prevented by the inhibitor cystamine. Immunohistochemical studies on postmortem brain tissue confirmed the presence of transglutaminase-catalyzed ε(γ-glutamyl)-lysine cross-links in the halo of Lewy bodies in Parkinson's disease and dementia with Lewy bodies, colocalizing with α-synuclein. These findings, taken together, suggest that tTGase activity leads to α-synuclein aggregation to form Lewy bodies and perhaps contributes to neurodegeneration. |
---|---|
Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Article-1 ObjectType-Feature-2 To whom correspondence should be addressed. E-mail: MouradianM@ninds.nih.gov. Communicated by Marshall Nirenberg, National Institutes of Health, Bethesda, MD |
ISSN: | 0027-8424 1091-6490 |
DOI: | 10.1073/pnas.0438021100 |