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Mitochondrial transcription factor A (TFAM) is essential for transcription and replication of mammalian mitochondrial DNA (mtDNA). Disturbance of maintenance of mtDNA integrity or mitochondrial function may underlay neurodegenerative disorders such as Alzheimer disease (AD). TFAM, the gene encoding TFAM maps to chromosome 10q21.1, a region that showed linkage to late-onset AD in several study samples. We screened TFAM for single nucleotide polymorphisms (SNPs) and genotyped the G>C SNP rs1937, coding for S12T in mitochondrial signal sequence of TFAM, and the A>G SNP rs2306604 (IVS4+113A>G) in 372 AD patients and 295 nondemented control subjects. There was an association of genotype rs1937G/G with AD in females and an association of a TFAM haplotype with AD both in the whole sample and in females. The findings suggest that a TFAM haplotype containing rs1937 G (for S12) may be a moderate risk factor for AD.

Reduced levels of protein kinase C alpha (PKC alpha) seems to be related to an altered amyloid precursor protein (APP) secretion in fibroblasts from Alzheimer's disease (AD) patients. In this report we used a specific inhibitor of PKC alpha (Gö-6976), to investigate the role of PKC alpha in the basal and phorbol esters regulated secretion of soluble APP (sAPP) in human fibroblasts derived from healthy aged volunteers. Treatment with Gö-6976 alone reduced basal secretion by a maximum of 39%, compared to untreated cells, suggesting the partial dependence of constitutive APP secretory pathway on PKC alpha enzyme. Moreover Gö-6976 treatment completely abolished the effect of phorbol-esters mediated PKC stimulation on sAPP release, suggesting that PKC alpha is the only PKC isoform involved in controlling the secretion of sAPP in human fibroblasts.

Frontotemporal dementia (FTD) is a clinical entity grouping different diagnostic conditions. FTD can occur in a sporadic form; however in 30-50% of cases a familial form of FTD has been observed. Mutations in the TAU gene were associated to familial FTD linked to chromosome 17. Our aim was to investigated the proportion of FTD cases attributable to TAU gene mutations in an Italian clinical series. We analyzed 38 patients with FTD; of these, 13 had a positive family history of FTD. All TAU gene exons and flanking intronic regions were sequenced. In our familial FTD sample the estimation of TAU gene mutations accounted for a relative low prevalence (7.6%); based on our results we could argue the existence of other mutations in regulatory regions in the TAU gene or, on the other hand, other genes might be responsible for the most cases of familial FTD.

The frequent polymorphism XbaI (A351G) in the estrogen receptor alpha (ERalpha) gene has been associated with some postmenopausal pathologies' risk such as Alzheimer's disease (AD) or cognitive decline. In the present study, we explored whether the XbaI polymorphism leads to different gray matter volumes using voxel-based morphometry (VBM) on 20 magnetic resonance images of healthy postmenopausal women. Subjects carrying the less common XbaI/X allele were contrasted to non-carriers in groups well balanced by relevant confounding variables. The XbaI/X allele carriers displayed clusters ranging from 9 to 28% of tissue reductions in the cerebellar (cluster size, z, stereotactic coordinates: 16 mm(3); 3.17; 14, -94, -38) and cerebral cortex, in particular in the occipital lobe (272 mm(3); 3.76; -38,-68,-16), in the middle frontal gyrus (192 mm(3); 3.71; 38, 12, 38) and in the middle temporal gyrus, while the opposite comparison was negative. The XbaI/X allele in ERalpha gene is associated to smaller gray matter volumes of the cerebral and cerebellar cortex. This allele might increase the susceptibility for senile neurodegenerative conditions, being associated to smaller cerebral reserve.

Clinical and immunopathological evidence support a potential role of the pro- and anti-inflammatory cytokine network in neurodegeneration of Alzheimer's disease (AD). Moreover, association studies suggest a possible involvement of cytokine-related genes in the susceptibility to sporadic AD. Since conflicting results are associated with the pro-inflammatory pathway, we investigated a putative effect of the anti-inflammatory counterpart focusing on the interleukin-10 (IL-10) gene. The 5′ flanking region contains numerous polymorphisms; in particular, three single nucleotide polymorphisms (−1082 G/A, −819 T/C, −592 C/A) are in linkage disequilibrium resulting in three haplotypes GCC, ACC and ATA. We analyzed the IL-10 haplotype distributions in 215 Italian sporadic AD patients and 153 controls in an association case-control study. Haplotype frequencies did not reveal differences between the two samples, however the genotype GCC/ACC was more represented in AD patients (OR 1.91, 95% CI: 1.18–3.07). This putative risk factor could be independent of the presence of the ApoE e4 allele. Our results provide new insights on a possible involvement of the IL-10 gene in susceptibility to sporadic AD even though further functional and genetic investigations are necessary to clarify its role in AD.

Apolipoprotein(a) [apo(a)] is a genetically polymorphic glycoprotein that has several similarities to apolipoprotein E. However, its role as a risk factor for frontotemporal dementia (FTD) remains to be elucidated. We therefore investigated the effect of an apo(a) polymorphism on the incidence of FTD in a sample of Caucasian Italian patients. From the entire group of FTD patients ( n =54), 55.6% of the subjects had at least one apo(a) low molecular weight (MW) isoform, compared to 29.9% of non-demented controls ( n =77). The difference between the two groups was statistically significant (odds ratio 2.93, 95% confidence interval 1.42–6.06, P =0.003). The FTD group was further divided into sporadic ( n =26) and familial ( n =28) cases. Even after such dichotomization, both sporadic and familial FTD patients showed a significantly higher prevalence of low MW apo(a) isoforms than the cognitively healthy controls ( P =0.011 and P =0.025, respectively). Our data suggest a role of apo(a) phenotypes of low MW in mediating susceptibility to FTD.

Apolipoprotein(a) [apo(a)] is a highly polymorphic glycoprotein which has been suggested to play a role in Alzheimer's disease (AD). Plasma lipoprotein(a) [Lp(a)] levels and the differential expression of apo(a) isoforms were analyzed in 73 sporadic AD patients compared with 73 age- and gender-matched healthy controls. The distribution of apo(a) isoforms and Lp(a) concentrations were similar in the two groups. However, we observed that AD patients with no apo(a) isoform from immunoblots (subjects with the ‘null phenotype’) had a mean age at onset of 76.8±8.8 versus 66.9±9.6 years of those who expressed at least one apo(a) band ( P =0.010). Multivariate analysis showed that this effect was independent of apolipoproteinE ϵ4 allele. We conclude that the expression of at least one apo(a) isoform may interact with other pathogenic mechanisms involved in controlling the age at onset of AD.

The present study investigates the influence of aglycemia and sodium azide (a Cytochrome c Oxidase inhibitor) on sAPP secretion from skin fibroblasts derived from sporadic AD patients and control subjects. Aglycemia reduced sAPP release in the medium of both AD and control fibroblasts to a similar extent after 2 h incubation. Treatment for 2 h with increasing azide concentrations (1 microM-100 mM) under glucose deprivation did not significantly affect sAPP secretion from control fibroblasts, but was able to significantly inhibit sAPP secretion from AD fibroblasts (maximal inhibition 51%). The failure of antioxidants like glutathione (GSH) or N-acetylcysteine (NAC) to antagonize the azide effect on AD fibroblasts and lipoperoxidation data seemed to rule out the possibility that oxidative stress could mediate the sodium azide effect on sAPP release from AD fibroblasts.

The present study investigates the influence of energy related metabolic stress on amyloid precursor protein (APP) non-amyloidogenic secretory processing in COS cells. The effect of glucose deprivation on soluble APP (sAPP) secretion has been evaluated: incubation of COS cells with 50 mM 2-deoxy-D-glucose (2-DG) in glucose free medium was able to reduce sAPP secretion (-26%). Sodium azide (NaN3), an inhibitor of cytochrome c oxidase (complex IV of the mitochondrial electron transfer chain) decreased sAPP release in a concentration dependent way (maximum -75%). Treatment of COS cells with the antioxidant glutathione (GSH) fully antagonized the inhibitory effect of azide (1 mM) and elicited sAPP release over basal level. These results suggest that the inhibition of energy metabolism can influence APP processing leading to a decreased secretion of non-amyloidogenic fragments of APP.