Biochemical and histopathological alterations in TAR DNA-binding protein-43 after acute ischemic stroke in rats.
Nuclear factor TAR DNA-binding protein-43 (TDP-43) is considered to play roles in pathogenesis of human neurodegenerative diseases, so-called TDP-43 proteinopathy, via its proteolytic cleavage, abnormal phosphorylation, subcellular redistribution, and insolubilization generating TDP-43-positive neuronal intracellular inclusions. The purpose of this study was to elucidate biochemical and histopathological alternations in TDP-43 specific to acute ischemic stroke. Adult male rats were subjected to a 90-min middle cerebral artery occlusion. We examined the proteolytic cleavage, phosphorylation, subcellular localization, and solubility of TDP-43 by immunoblottings and histopathological examinations using the ischemic and sham-operated cortex. The level of full-length TDP-43 (43 kDa) decreased and that of the 25-kDa C-terminal fragment increased after acute ischemic stroke, which can be explained by proteolytic cleavage of TDP-43. Cytoplasmic redistribution and altered nuclear distribution of TDP-43 was observed after acute ischemic stroke, whereas abnormal phosphorylation and insolubilization of TDP-43 as well as formation of intracellular inclusions were not observed. Ischemic neurons with the cytoplasmic redistribution of TDP-43 expressed ubiquitin and activated caspase 3 and were terminal deoxynucleotidyl transferase-mediated uridine 5'-triphosphate-biotin nick end labeling-positive. In conclusion, biochemical and histopathological alterations in TDP-43 were identified in rats after acute ischemic stroke, although there was very less similarity between TDP-43 alterations observed in acute ischemic stroke and those observed in TDP-43 proteinopathy.
Kanazawa
Masato
M
Department of Neurology, Brain Research Institute, Niigata University, Niigata, Japan.
Kakita
Akiyoshi
A
Igarashi
Hironaka
H
Takahashi
Tetsuya
T
Kawamura
Kunio
K
Takahashi
Hitoshi
H
Nakada
Tsutomu
T
Nishizawa
Masatoyo
M
Shimohata
Takayoshi
T
D000818:Animals; D001921:Brain / Q000473:pathology*; D002452:Cell Count / Q000379:methods; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors / Q000008:administration & dosage; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D020287:In Situ Nick-End Labeling; D007276:Injections, Intraventricular / Q000379:methods; D007511:Ischemia / Q000150:complications; D008297:Male; D008970:Molecular Weight; D009474:Neurons / Q000378:metabolism / Q000473:pathology; D009842:Oligopeptides / Q000008:administration & dosage; D010766:Phosphorylation / Q000187:drug effects / Q000502:physiology; D021381:Protein Transport / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D018709:Statistics, Nonparametric; D020521:Stroke / Q000209:etiology / Q000378:metabolism* / Q000473:pathology*; D013997:Time Factors; D025801:Ubiquitin / Q000378:metabolism
D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; D009842:Oligopeptides; D025801:Ubiquitin; C516668:benzyloxycarbonyl-aspartyl(OMe)-isoleucyl-prolyl-aspartyl(OMe) fluoromethylketone