Abstract
Neurofibrillary tangles (NFTs), which are composed of paired helical filament (PHF)-like filaments, were induced by the long-term intraventricular infusion of leupeptin, a potent protease inhibitor. The fibrils composing the NFTs were 20 nm in maximal width and had periodic constrictions at 40-nm intervals. They were identical to the PHF that had been found in aged rat neurons. Dystrophic axons filled with mainly tubular structures were also abundantly found in the parietal and temporal isocortices, which were not affected in the acute or subacute phases of leupeptin treatment. An immunohistochemical study using antibodies related to the neuronal cytoskeleton showed that neuronal cytoskeletal changes accompanying ubiquitination occurred in dystrophic axons distributed widely in the isocortex as well as the hippocampal formation. The present findings suggest that long-term administration of leupeptin accelerates the neuronal ageing process in rats and causes other neuronal changes: NFT formation, such as seen in the aged brain or in neurodegenerative diseases including Alzheimer's disease, in addition to accumulation of lipofuscin granules and degeneration of neuronal processes. In other words, some disturbance of the balance between proteases and their inhibitors may play an important role in the neuronal ageing process, and some regulatory intervention in the intraneuronal protease activity may provide a new therapeutic strategy for the neurodegenerative diseases.
Similar content being viewed by others
References
Bizzi A, Gambetti P (1986) Phosphorylation of neurofilaments is altered in aluminium intoxication. Acta Neuropathol (Berl) 71: 154–158
Braak H, Braak E (1991) Neuropathological stageing of Alzheimer-related changes. Acta Neuropathol 82: 239–259
Cavanagh JB, Nolan CC, Seville MP, Anderson VER, Leigh PN (1993) Routes of excretion of neuronal lysosomal dense bodies after ventricular infusion of leupeptin in the rat: a study using ubiquitin and PGP 9.5 immunocytochemistry. J Neurocytol 22: 779–791
Ikegami S, Takauchi S, Miyoshi K (1993) Trophic and inhibitory effect of protease inhibitor, leupeptin in the rat neural tissue culture. In: Nicolini M, Zatta PF, Corain B (eds) Alzheimer's disease and related disorders. Selected Communications. Pergamon Press, Oxford, pp 309–310
Ivy GO, Schottler F, Wenzel J, Baudry M, Lynch G (1984) Inhibitors of lysosomal enzymes: accumulation of lipofuscin-like dense bodies in the brain. Science 226: 985–987
Ivy GO, Kitani K, Ihara Y (1989) Anomalous accumulation of τ and ubiquitin immunoreactivities in rat brain caused by protease inhibition and by normal aging: a clue to PHF pathogenesis? Brain Res 498: 360–365
Kidd M (1963) paired helical filaments in electron microscopy in Alzheimer's disease. Nature 197: 192–193
Klatzo I, Wisneiewski, Streicher E (1965) Experimental production of neurofibrillary degeneration: light microscopic observation. J Neuropathol Exp Neurol 24: 187–199
Klosen P, van den Bosch de Aguilar P (1993) Paired helical filament-like inclusion and Hirano bodies in the mesencephalic nucleus of the trigeminal nerve in the aged rat. Virchows Arch [B] 63: 91–97
Knox CA, Yates RD, Chen I-li (1980) Brain aging in normotensive and hypertensive strains of rats. II. Ultrastructural changes in neurons and glia. Acta Neuropathol (Berl) 52: 7–15
Kosik KS (1991) The neuritic dystrophy of Alzheimer's disease: degeneration or regeneration? In: Hefti F, Brachet P, Wil B, Christen Y (eds) Growth factors and Alzheimer's disease. Springer-Verlag, Berlin Heidelberg New York Tokyo, pp 124–126
Nunomura A, Miyagishi T (1993) Ultrastructural observations on neuronal lipofuscin (age pigment) and dense bodies induced by a protease inhibitor, leupeptin in rat hippocampus. Acta Neuropathol 86: 319–328
Perry G, Kawai M, Tabaton M, Onorato M, Mulvihill P, Richey P, Morandi A, Connolly JA, Gambetti P (1991) Neuropil threads of Alzheimer's disease show a marked alteration of the normal cytoskeleton. J Neurosci 11: 1748–1755
Sato M, Miyoshi K (1984) Ultrastructural observations on the vincristine-induced neuronal crystalloid inclusion in young rats. Acta Neuropathol (Berl) 63: 150–159
Takauchi S, Miyoshi K (1989) Degeneration of neuronal processes in rats induced by a protease inhibitor, leupeptin. Acta Neuropathol 78: 380–387
Takauchi S, Miyoshi K (1990) Degeneration of neuronal processes in rats induced by the protease inhibitor leupeptin. In: Nagatsu T, Fisher A, Yoshida M (eds) Basic, clinical, and therapeutic aspects of Alzheimer's and Parkinson's disease. Plenum Press, New York, pp 75–78
Takauchi S, Miyoshi K (1991) Protease inhibitor, leupeptin, causes irreversible axonal changes in rats. In: Iqbal K, McLachlan DRC, Winblad B, Wisniewski HM (eds) Alzheimer's disease: basic mechanisms, diagnosis and therapeutic strategies. Wiley, Chichester, pp 505–513
Takauchi S, Ikegami S, Miyoshi K (1993) Neurofibrillary change in rat brain as a long-term effect by intraventricular infusion of protease inhibitor leupeptin. In: Nicolini M, Zatta PF, Corain B (eds) Alzheimer's disease and related disorders. Selected communications. Pergamon Press, Oxford, pp 323–324
Takeda M, Tatebayashi Y, Tanimukai S, Nakamura Y, Tanaka T, Nishimura T (1991) Immunohistochemical study of microtubule-associated protein 2 and ubiquitin in chronically aluminum-intoxicated rabbit brain. Acta Neuropathol 82: 346–352
Takeda M, Nishimura T, Kudo T, Tanimukai S, Tada K (1991) Buffy coat from families of Alzheimer's disease patients produces intracytoplasmic neurofilament accumulation in hamster brain. Brain Res 551: 319–321
Tomlinson BE (1992) Ageing and the dementias. In: Adams JH, Duchen LW (eds) Greenfield's neuropathology, 5th edn. Edward Arnold, London, pp 1284–1410
van den Bosch de Aguilar P, Goemaere-Vannesteand J (1984) Paired helical filaments in spinal ganglion neurons of elderly rats. Virchows Arch [B] 47: 217–222
Wisniewski H, Terry RD (1967) Experimental colchicine encephalopathy. 1. Induction of neurofibrillary degeneration. Lab Invest 17: 577–587
Wisniewski H, Terry R (1970) An experimental approach to the morphogenesis of neurofibrillary degeneration and the argyrophilic plaque. In: Wolstenholme GEW, O'Connor M (eds) Alzheimer's disease and related conditions. Churchill, London, pp 223–248
Wood JG, Mirra SS, Pollock NJ, Binder LI, (1986) Neurofibrillary tangles of Alzheimer disease share antigenic determinants with the axonal microtubule-associated protein tau (τ). Proc Natl Acad Sci USA 83: 4040–4043
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Takauchi, S., Miyoshi, M. Cytoskeletal changes in rat cortical neurons induced by long-term intraventricular infusion of leupeptin. Acta Neuropathol 89, 8–16 (1995). https://doi.org/10.1007/BF00294253
Received:
Revised:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00294253