Immunohistochemical characterisation of classical scrapie neuropathology in sheep.
Neuroinflammation elicited by PrP(res) (resistant prion protein [PrP]) deposits in the central nervous system (CNS) has been shown to involve cellular and oxidative stress responses in bovine spongiform encephalopathy (BSE) as well as in several murine models of transmissible spongiform encephalopathy (TSE). Additionally, deregulation of water homeostasis has been suggested to be a further component of the spongiform changes observed in TSEs. The aim of the present study was to characterize the pathogenic events occurring in the CNS of sheep with spontaneously arising classical scrapie. Brains from seven affected animals and two controls were subject to immunohistochemical and histochemical examinations. Semi-quantitative evaluation of PrP(res) deposits and spongiform changes throughout the encephalon confirmed that PrP(res) deposition elicits significant astroglial and microglial reactions, as evidenced by an increase in the number of glial cells and changes in glial cell morphology involving increased expression of vimentin. The altered expression of metallothionein and heat shock protein 25 (HSP25) suggested that this neuroinflammatory reaction entails cellular and oxidative stress responses. In contrast, there was no change in expression of the membrane-associated water channel aquaporin 1 when PrP(res) accumulated in the brain.
Vidal
E
E
Priocat Laboratory, Centre de Recerca en Sanitat Animal, UAB-IRTA, Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain. enric.vidal@cresa.uab.cat
Acín
C
C
Foradada
L
L
Monzón
M
M
Márquez
M
M
Monleón
E
E
Pumarola
M
M
Badiola
J J
JJ
Bolea
R
R
D000818:Animals; D001253:Astrocytes / Q000378:metabolism / Q000473:pathology; D015415:Biomarkers / Q000378:metabolism; D001921:Brain / Q000378:metabolism / Q000473:pathology*; D005260:Female; D019085:Fluorescent Antibody Technique, Direct / Q000662:veterinary; D006360:Heat-Shock Proteins / Q000378:metabolism; D008668:Metallothionein / Q000378:metabolism; D017628:Microglia / Q000378:metabolism / Q000473:pathology; D018384:Oxidative Stress / Q000502:physiology; D018620:PrPSc Proteins / Q000378:metabolism*; D012608:Scrapie / Q000378:metabolism / Q000473:pathology*; D012756:Sheep; D014746:Vimentin / Q000378:metabolism
D015415:Biomarkers; D006360:Heat-Shock Proteins; D018620:PrPSc Proteins; D014746:Vimentin; D008668:Metallothionein