Altered expression of apolipoprotein E, amyloid precursor protein and presenilin-1 is associated with chronic reactive gliosis in rat cortical tissue.
Neuroscience
; 106(3): 557-69, 2001.
Article
en En
| MEDLINE
| ID: mdl-11591456
ABSTRACT
A major characteristic feature of Alzheimer's disease is the formation of compact, extracellular deposits of beta-amyloid (senile plaques). These deposits are surrounded by reactive astrocytes, microglia and dystrophic neurites. Mutations in three genes have been implicated in early-onset familial Alzheimer's disease. However, inflammatory changes and astrogliosis are also believed to play a role in Alzheimer's pathology. What is unclear is the extent to which these factors initiate or contribute to the disease progression. Previous rat studies demonstrated that heterotopic transplantation of foetal cortical tissue onto the midbrain of neonatal hosts resulted in sustained glial reactivity for many months. Similar changes were not seen in cortex-to-cortex grafts. Using this model of chronic cortical gliosis, we have now measured reactive changes in the levels of the key Alzheimer's disease proteins, namely the amyloid precursor protein, apolipoprotein E and presenilin-1. These changes were visualised immunohistochemically and were quantified by western blot analysis. We report here that chronic cortical gliosis in the rat results in a sustained increase in the levels of apolipoprotein E and total amyloid precursor protein. Reactive astrocytes in heterotopic cortical grafts were immunopositive for both of these proteins. Using a panel of amyloid precursor protein antibodies we demonstrate that chronic reactive gliosis is associated with alternative cleavage of the peptide. No significant changes in apolipoprotein E or amyloid precursor protein expression were seen in non-gliotic cortex-to-cortex transplants. Compared to host cortex, the levels of both N-terminal and C-terminal fragments of presenilin-1 were significantly lower in gliotic heterotopic grafts.The changes described here largely mirror those seen in the cerebral cortex of humans with Alzheimer's disease and are consistent with the proposal that astrogliosis may be an important factor in the pathogenesis of this disease.
Buscar en Google
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Apolipoproteínas E
/
Corteza Cerebral
/
Astrocitos
/
Precursor de Proteína beta-Amiloide
/
Enfermedad de Alzheimer
/
Gliosis
/
Proteínas de la Membrana
Tipo de estudio:
Prognostic_studies
/
Risk_factors_studies
Límite:
Animals
Idioma:
En
Revista:
Neuroscience
Año:
2001
Tipo del documento:
Article