Presenilin 2 mutation R71W in an Italian early-onset sporadic Alzheimer's disease case.

Mutations in the presenilin 2 (PSEN2) gene are less commonly identified as genetic causes of early-onset familial Alzheimer's disease than mutations in the amyloid precursor protein (APP) and the presenilin 1 (PSEN1) genes. In fact, only 23 different mutations in the PSEN2 gene have been described in the literature. This paper deals with a sporadic case of a 55 year-old subject bearing an amino acid substitution from arginine to tryptophan at codon 71 of PSEN2 and presenting a peculiar early-onset Alzheimer's disease phenotype.

Hypoxia induces up-regulation of progranulin in neuroblastoma cell lines.

Progranulin (PGRN) is a widely expressed multifunctional protein, involved in regulation of cell growth and cell cycle progression with a possible involvement in neurodegeneration. We looked for PGRN regulation in three different human neuroblastoma cell lines, following exposure to two different stimuli commonly associated to neurodegeneration: hypoxia and oxidative stress. For gene and protein expression analysis we carried out a quantitative RT-PCR and western blotting analysis.

A novel mutation in the predicted TMIII domain of the PSEN2 gene in an Italian pedigree with atypical Alzheimer's disease.

Alzheimer's disease (AD) is characterized by accumulation of toxic amyloid-beta (Abeta) in the brain, with neuronal death, and an associated increased Abeta(42/40) ratio. Several mutations in presenilin 1 (PSEN1), presenilin 2 (PSEN2), and amyloid-beta precursor protein are involved in the etiology of familial AD (FAD); these mutations alter the Abeta(42/40) ratio and promote apoptosis. We describe an Italian pedigree linked to a novel mutation (S175C) at the third transmembrane domain of PSEN2.

Gene expression profiles of APP and BACE1 in Tg SOD1G93A cortical cells.

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease defined by motor neuron loss. Transgenic mouse model (Tg SOD1G93A) shows pathological features that closely mimic those seen in ALS patients. An hypothetic link between AD and ALS was suggested by finding an higher amount of amyloid precursor protein (APP) in the spinal cord anterior horn neurons, and of Abeta peptides in ALS patients skin.

Genetic study of Sardinian patients with Alzheimer's disease.

We describe the genetic analysis of an Alzheimer's disease (AD) sample derived from a genetically isolated population. Genetic assessment included the analysis of genes involved in AD, such as the genes for amyloid precursor protein (APP), presenilin 1 (PSEN1) and presenilin 2 (PSEN2). We also assessed genes for some proteins that constitute the gamma-secretase complex: nicastrin (NCSTN), presenilin enhancer-2 (PEN2), in addition to the AD risk factor apolipoprotein E (APOE).

Rat nicastrin gene: cDNA isolation, mRNA variants and expression pattern analysis.

Nicastrin is a type 1 transmembrane glycoprotein that interacts with presenilin, Aph-1, and Pen-2 proteins to form a high molecular complex with gamma secretase activity. Then, nicastrin has a central role in presenilin-mediated processing of beta-amyloid precursor protein and in some aspects of Notch/glp-1 signaling in vivo. Here, we isolated a rat nicastrin cDNA and investigated gene expression in embryonic and adult rat tissues.

Effects of simulated microgravity on the development and maturation of dissociated cortical neurons.

Although a wealth of evidence supports the hypothesis that some functions of the nervous system may be altered during exposure to microgravity, the possible changes in basic neuronal physiology are not easy to assess. Indeed, few studies have examined whether microgravity affects the development of neurons in culture. In the present study, a suspension of dissociated cortical cells from rat embryos were exposed to 24 h of simulated microgravity before plating in a normal adherent culture system.

Nicastrin gene in familial and sporadic Alzheimer's disease.

Nicastrin is a protein recently discovered associated to presenilins and involved in the production of amyloid beta peptide that accumulates in Alzheimer's disease (AD) brain. In this study the nicastrin gene was examined for unknown mutations and polymorphisms in 104 patients with familial AD (52 early-onset and 52 late-onset), 174 sporadic AD and 191 healthy neurological controls of Italian origin. The scanning of the nicastrin gene identified a missense mutation (N417Y) in two patients with sporadic AD, in an early-onset familial AD and in a young control subject.