Evidence that formation of an intermediate filament-protein complex plays a primary role in aggregation of neurofilaments, glial fibrillary acidic protein (GFAP)-filaments and vimentin-filaments by 2,5-hexanedione.
Using a variety of cell types in culture, we have investigated the relevance of intermolecular crosslinking involving intermediate filament proteins (IF-proteins) to the changes in distribution of intermediate filaments induced by the neurotoxicant, 2,5-hexanedione (2,5HD). Aggregation of vimentin-filaments (vimentin-IF), glial fibrillary acidic protein (GFAP)-IF and neurofilaments was preceded by appearance on immunoblots of a high molecular weight complex (IF-complex) labeled by antibodies against the IF-protein of the cell type: pV-170 from human skin fibroblasts and pV-130 from 3T3 mouse fibroblasts, which were labeled by anti-vimentin and, from cultures of dissociated mouse spinal cord and dorsal root ganglia, pNFH-300 labeled by antibody against the 200 kDa neurofilament protein (NF-200 or NF-H) and a doublet labeled by antiserum to GFAP (pGFAP-145).pV-170 was detected in human skin fibroblasts within one hour of exposure to 2,5HD and the amount of both pV-170 and pNFH-300 was related to the concentration of 2,5HD and the duration of exposure. Intermediate filament-complexes were not detected in PtK1 epithelial cells by labeling of transblots with anti-cytokeratin, nor are keratin-IF aggregated by 2,5HD. Intermediate filament-complexes were not detected in fibroblasts with IF-aggregates secondary to disruption of microtubules by colchicine or in fibroblasts from patients with giant axonal neuropathy.
Durham
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HD
Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Quebec, Canada.
Salera
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Dahrouge
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D002478:Cells, Cultured; D003599:Cytoskeleton / Q000187:drug effects*; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism*; D006588:Hexanones / Q000494:pharmacology*; D006801:Humans; D007381:Intermediate Filament Proteins / Q000378:metabolism*; D007382:Intermediate Filaments / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D007633:Keratins / Q000378:metabolism; D007659:Ketones / Q000494:pharmacology*; D012867:Skin / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D014746:Vimentin / Q000378:metabolism*
D005904:Glial Fibrillary Acidic Protein; D006588:Hexanones; D007381:Intermediate Filament Proteins; D007659:Ketones; D014746:Vimentin; D007633:Keratins; C011269:2,5-hexanedione