[Expression and localization of the cellular prion protein (PrPc) in the cow's central nervous system. Some reflections on the nvCJD].
BACKGROUND
The appearance of bovine spongiform encephalopathy (BSE) and its involvement in the generation of the new variant of Creutzfeldt-Jakob Disease (nvCJD) had important implications from a social and economical point of view. As the presence of PrPC is necessary to establish prion diseases and for the replication of PrPSC in BSE, the study of the expression and localization of PrPC in the central nervous system of cow, mainly the brainstem, is interesting itself.


METHODS
Expression of PrP by western blot technique and its precise localization by immunohistochemistry were analyzed in the central nervous system of the autochthonous pyrenees breed, a group of cows with a high incidence for BSE.


RESULTS
PrP was more abundantly expressed in rostral areas rather than caudal regions of the cow brain. Immunohistochemistry was congruent with western blotting studies. Localization of PrPC was particularly abundant in the cerebral cortex, hippocampus, etc. Noteworthy, immunopositivity was present in the dorsal motor nucleus of the vagus and the hypoglossal nucleus. The anterior horn of the spinal cord yielded higher labelling for PrP than the posterior horn.


CONCLUSIONS
PrPC is more abundantly expressed in rostral areas of the central nervous system. According to the findings observed in other mammal species, presence of PrPC in motoneurons of cow indicates that PrPSc might be transported from its site of entry to the central nervous system following a retrograde direction.
Velavos
J L
JL
Departamento de Anatomia, Facultad de Medicina, Universidad de Navarra, Pamplona. jvelayos@unav.es
Moleres
F J
FJ
Cuadrado
M M
MM
Irujo
A M
AM
Paternain
B
B
D000818:Animals; D002417:Cattle; D002490:Central Nervous System / Q000033:anatomy & histology / Q000737:chemistry* / Q000378:metabolism* / Q000473:pathology; D007562:Creutzfeldt-Jakob Syndrome / Q000378:metabolism* / Q000473:pathology; D016643:Encephalopathy, Bovine Spongiform / Q000378:metabolism / Q000473:pathology; D006801:Humans; D018621:PrPC Proteins / Q000235:genetics / Q000378:metabolism*; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism
D018621:PrPC Proteins; D020033:Protein Isoforms