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Biomedical subjects

Sara Massone

Publications and source records attributed to Sara Massone.

3 recordsLinked to original sources

Evidence against the overexpression of APP in Down syndrome.

Down syndrome (DS) is the most common genetic disorder with mental retardation and is caused by trisomy 21. By the age of 40 years, virtually all adults with DS have sufficient neuropathology for a diagnosis of Alzheimer's disease (AD), which is characterized by accumulation of amyloid-beta in senile plaques and formation of neurofibrillary tangles. Amyloid-beta derives from a longer precursor protein, APP, whose gene maps to chromosome 21. In DS, the early appearance of senile plaques is commonly associated with the presence of a third copy of the APP gene. Here we show DS brains and trisomic fibroblasts in which APP is not overexpressed, compared to euploid controls, challenging the notion that the widespread amyloid-beta deposits, consistently found in DS individuals, result from an extra copy of APP.

Adult↗

Role of peroxisome proliferator-activated receptor gamma in amyloid precursor protein processing and amyloid beta-mediated cell death.

Recent data indicate that PPARgamma (peroxisome proliferator-activated receptor gamma) could be involved in the modulation of the amyloid cascade causing Alzheimer's disease. In the present study we show that PPARgamma overexpression in cultured cells dramatically reduced Abeta (amyloid-beta) secretion, affecting the expression of the APP (Abeta precursor protein) at a post-transcriptional level. APP down-regulation did not involve the pathway of the secretases and correlated with a significant induction of APP ubiquitination. Additionally, we demonstrate that PPARgamma was able to protect the cells from H(2)O(2)-induced necrosis by decreasing Abeta secretion. Taken together, our results indicate a novel mechanism at the basis of the neuroprotection shown by PPARgamma agonists and an additional pathogenic role for Abeta accumulation.

Alzheimer Disease↗

Microarray analysis in Alzheimer's disease and normal aging.

The purpose of this study was to investigate gene expression in Alzheimer's disease (AD), the most common form of senile dementia. We utilized the microarray technology to simultaneously compare the expression profile of 12,000 human genes in cerebral cortex of AD and normal aging. To identify gene expression related to neurodegeneration, beside the presence of amyloid deposition, we used control brains with abundant amyloid plaques, derived from cognitively normal elderly subjects. The microarray analysis indicated that 314 genes were differentially expressed in AD cerebral cortex, with differences greater than 5 folds in 25 genes. RT-PCR performed on a selected group of genes confirmed the increased expression of the interferon-induced protein 3 in AD brain. This protein, which is highly inducible by both type I and type II interferons, was not previously associated with the neurodegenerative disease.

Aged↗