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Biomedical subjects

Eliana Venturelli

Publications and source records attributed to Eliana Venturelli.

13 recordsLinked to original sources

Absence of TREM2 polymorphisms in patients with Alzheimer's disease and Frontotemporal Lobar Degeneration.

Triggering Receptor Expressed on Myeloid cells (TREM)2 deficiency originates a genetic syndrome characterized by bone cysts and presenile dementia, named Nasu-Hakola disease (NHD). Early onset dementia and marked involvement of frontal regions are features characterizing both NHD and other kinds of neurodegenerative disorders, such as Frontotemporal Lobar Degeneration (FTLD), and, in some cases, Alzheimer's disease (AD). Three Single Nucleotide Polymorphisms (SNPs) in TREM2 coding region were screened by allelic discrimination in a population of probable AD patients as well as FTLD patients as compared with age-matched controls. In addition, mutation scanning of the coding region of TREM2 gene was carried out in 7 patients with early onset AD (EOAD), 16 FTLD, and 20 controls. None of the SNPs analyzed was present, either in patients or controls. Moreover, mutation scanning of the five exons of TREM2 failed to detect the presence of novel polymorphisms. These data demonstrate that TREM2 coding region is highly conserved, implying a crucial role of this receptor. Further studies, including a functional analysis, are certainly required to clarify the role of TREM2 in neurodegenerative processes.

Aged↗

Candidate gene analysis of IP-10 gene in patients with Alzheimer's disease.

Interferon-gamma-inducible Protein-10 (IP-10) is supposed to play a role in Alzheimer's disease (AD) development, as demonstrated by increased levels in cerebrospinal fluid from patients with AD. A mutation scanning of IP-10 exonic region was carried out in 10 patients with AD and 10 age-matched controls, demonstrating the presence of two previously reported single nucleotide polymorphisms (SNPs) in exon 4 (G-->C and T-->C) as well as a novel SNP in exon 2 (C-->T). Exon 4 G-->C and T-->C allelic variants were next evaluated in a population of 279 AD patients and 251 controls, in order to determine whether their presence could influence the susceptibility towards the development of the disease. These two SNPs were in complete linkage disequilibrium. No differences in haplotype frequencies were found in AD patients as compared with controls, even stratifying according to the presence of Apolipoprotein E varepsilon4 allele, gender or age at onset. A new protocol was developed to easily determine the C-->T SNP in exon 2. A preliminary analysis revealed a very low frequency of this allelic variant (1%). Therefore, the complete association study was not carried out because the size of our population was not sufficient to draw reliable conclusions. According to these results, IP-10 does not seem to be a risk factor for AD. However, a novel rare polymorphism has been identified, which could exert a role in AD susceptibility. Thus, further studies on larger populations are needed before confidently excluding IP-10 as a susceptibility gene for AD.

Age of Onset↗

A novel polymorphism in SEL1L confers susceptibility to Alzheimer's disease.

Alzheimer's disease (AD) is considered to be a conformational disease arising from the accumulation of misfolded and unfolded proteins in the endoplasmic reticulum (ER). SEL1L is a component of the ER stress degradation system, which serves to remove unfolded proteins by retrograde degradation using the ubiquitin-proteosome system. In order to identify genetic variations possibly involved in the disease, we analysed the entire SEL1L gene sequence in Italian sporadic AD patients. Here we report on the identification of a new polymorphism within the SEL1L intron 3 (IVS3-88 A>G), which contains potential binding sites for transcription factors involved in ER-induced stress. Our statistical analysis shows a possible role of the novel polymorphism as independent susceptibility factor of Alzheimer's dementia.

Aged↗

Intrathecal chemokine synthesis in mild cognitive impairment and Alzheimer disease.

BACKGROUND: Immunoreactivity for several chemokines and for their related receptors has been demonstrated in resident cells of the central nervous system, and the up-regulation of some of them is associated with pathological changes found in Alzheimer disease (AD). OBJECTIVE: To determine interferon-gamma-inducible protein 10 (IP-10), monocyte chemotactic protein 1 (MCP-1), and interleukin 8 (IL-8) levels in cerebrospinal fluid (CSF) from subjects with amnestic mild cognitive impairment (MCI) and patients with AD as compared with age-matched controls. PATIENTS: Thirty-eight subjects with amnestic MCI, 36 patients with AD, and 41 age-matched subjects with noninflammatory affections of the nervous system. DESIGN: Evaluation of CSF chemokine production at time of diagnosis of MCI and AD; correlation with clinical and personal data. Longitudinal evaluation of subjects with MCI until conversion to AD. RESULTS: Cerebrospinal fluid IP-10 concentration was significantly increased in patients with MCI and mild AD but not in patients with severe AD (Mini-Mental State Examination score <15), whereas MCP-1 and IL-8 levels were increased in patients with MCI and all patients with AD. A significant positive correlation between Mini-Mental State Examination score and CSF IP-10 or MCP-1 concentration was observed in patients with AD. No correlation between IP-10 levels and age was found, whereas MCP-1 and IL-8 levels correlated positively with age. Out of 38 subjects with MCI, 19 developed AD within a 1- to 3-year follow-up. CONCLUSIONS: The presence of inflammatory molecules is likely to be a very early event in AD pathogenesis, even preceding the clinical onset of the disease, as demonstrated by subjects with MCI who developed AD over time. Interferon-gamma-inducible protein 10 is specifically increased in MCI and seems to decrease with the progression of AD, whereas MCP-1 and IL-8 are up-regulated also in late stages of the disease, suggesting a role in phases in which neurodegeneration is prevalent.

Aged↗

Serum MCP-1 levels are increased in mild cognitive impairment and mild Alzheimer's disease.

Upregulation of a number of chemokines, including monocyte chemotactic protein-1 (MCP-1), is associated with Alzheimer's disease (AD) pathological changes. Emerging evidence suggests that inflammatory events precede the clinical development of AD, as cytokine disregulation has been observed also in patients with mild cognitive impairment (MCI). MCP-1 levels were evaluated in serum samples from 48 subjects with MCI, 94 AD patients and 24 age-matched controls. Significantly increased MCP-1 levels were found in MCI and mild AD, but not in severe AD patients as compared with controls. mRNA levels in peripheral blood mononuclear cells (PBMC), evaluated by quantitative RT-PCR analysis, paralleled serum MCP-1 levels. Moreover, a progressive MCP-1 decrease was observed over a 1-year follow up in a subgroup of MCI subjects converted to AD. MCP-1 upregulation is likely to be a very early event in AD pathogenesis, by far preceding the clinical onset of the disease. Nevertheless, as MCP-1 is likely to play a role in several pathologies with an inflammatory component, a possible usefulness as an early AD biomarker would be possible only in combination with other molecules.

Aged↗

P-selectin glycoprotein ligand-1 variable number of tandem repeats (VNTR) polymorphism in patients with multiple sclerosis.

P-selectin glycoprotein ligand-1 (PSGL-1) is an important adhesion molecule involved in lymphocyte recruitment into the brain, which represents a crucial step in the pathogenesis of multiple sclerosis (MS). Three hundred twenty-one MS patients and 342 controls were genotyped for the presence of a polymorphism in the PSGL-1 gene, consisting of a variable number of tandem repeats (VNTR) originating three possible alleles: A, B and C, in order to test whether they influence the susceptibility and the course of the disease. No significant differences among allelic frequencies of A, B and C alleles in MS as compared with controls were observed. Stratifying patients according to the course of the disease, a significantly increased frequency of the shortest C allele in PP-MS was found (7.1%), either in comparison with controls (P=0.011) or with all other MS patients, who had acute inflammatory attacks at onset and an initial RR form (P=0.036). Besides, none of SP-MS patients was a carrier of the C allele and B carriers converted later from RR to SP course as compared with A/A subjects (after 15.8 rather than 8.8 years, P=0.01). In conclusion, the C allele of the VNTR polymorphism in PSGL-1 is likely to be associated with PP-MS. As this allele has been demonstrated to have a very low efficiency in mediating lymphocyte binding to brain endothelium during attacks, its high frequency in PP-MS could be related to the absence of exacerbations in such patients.

Adult↗

SELPLG and SELP single-nucleotide polymorphisms in multiple sclerosis.

P-Selectin (SELP) and P-selectin glycoprotein ligand-1 (SELPLG) constitute a receptor/ligand complex involved in the recruitment of activated lymphocytes, a critical event in the pathogenesis of multiple sclerosis (MS). In order to determine whether genetic variation in these pivotal molecules influences susceptibility to MS, we genotyped 214 Italian patients compared with 220 Italian controls for three single-nucleotide polymorphisms (SNPs): SELPLG Met62Ile, SELP C-2123G and SELP Thr715Pro. No significant differences in both SELP SNPs were found between patients and controls, whereas a decreased frequency of the Met62Ile SNP was found in patients versus controls in the Italian population (P = 0.025). To confirm these preliminary findings, the Met62Ile SNP was analysed in 938 UK trio families. This SNP did not show evidence for association with susceptibility to MS in the larger UK cohort. Therefore, none of the SNPs investigated is associated with MS, although this analysis does not conclusively exclude SELPLG and SELP as genetic risk factors for MS as much variation remains untested.

Adult↗

The T-786C NOS3 polymorphism in Alzheimer's disease: association and influence on gene expression.

A common single nucleotide polymorphism (SNP), consisting in a T-->C transition (T-786C) in endothelial nitric oxide synthase (NOS3), has been reported to be associated with vascular pathologies, but no information are available on a possible association with AD. T-786C genotype was determined by polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP) assay in an Italian population of 432 AD patients compared with 360 healthy controls, matched for ethnic background, age and gender. Peripheral blood mononuclear cells (PBMC) from 22 subjects (11 AD and 11 controls) carrying different genotypes were isolated. Total RNA was extracted and analyzed by real-time PCR. No significant differences either in allelic or genotypic frequencies of the T-786C polymorphism between AD and normal population were observed, even stratifying AD patients by age at onset, gender, or ApoE status. However, expression of NOS3 in PBMC seems to be influenced by the presence of the C mutated allele, as demonstrated by a tendency towards a decrease in mRNA levels in C carriers, assessed by real-time PCR assay. This effect was observed both in patients and controls, independently from the cognitive impairment, and is likely to be dose-dependent, being mostly evident in CC homozygous. In conclusion, the T-786C SNP does not seem to be a risk factor for sporadic AD, but its presence correlates with a trend toward lower NOS3 expression rate, possibly exerting a beneficial effect in AD by contributing to lower oxidative damage.

Alzheimer Disease↗

Oxidative imbalance in patients with mild cognitive impairment and Alzheimer's disease.

Increasing evidence supports a role of oxidative imbalance, characterized by impaired antioxidant enzymatic activity and increased reactive oxygen species (ROS) production, in mild cognitive impairment (MCI) and Alzheimer's disease (AD) pathogenesis. Hyperhomocysteinemia, another risk factor for AD, also contributes to oxidative damage. Plasma total homocysteine (tHcy) and ROS levels, and total antioxidant capacity (TAC) were determined in 71 AD, 36 MCI and 28 vascular dementia (VaD) patients as well as in 44 age-matched controls. tHcy levels were significantly increased in patients with AD and VaD an a trend towards an increase in multiple domain MCI was observed. TAC was significantly decreased in AD as well as MCI, but not in VaD patients. In AD patients, a negative correlation was found between TAC and disease duration. ROS levels did not differ among groups, but were correlated with age. In conclusion, a pattern characterized by increased tHcy levels and decreased TAC is present in AD as well as MCI patients. While increased tHcy levels were also found in VaD, TAC modifications occur specifically in AD. ROS levels appear to be correlated with age rather than with a specific dementing disorder, thus leading to the hypothesis that oxidative imbalance observed in AD could be due to a decreased TAC.

Aged↗

E-selectin A561C and G98T polymorphisms influence susceptibility and course of multiple sclerosis.

Three hundred seven patients with MS and 300 controls were genotyped for G98T and A561C SNPs in the E-selectin gene, and genetic data were correlated with the course of the disease. The frequency of the T/T genotype of the G98T SNP was significantly increased in RR-MS patients compared with controls, while was absent in PP-MS. The frequency of the A561C SNP was significantly decreased in SP-MS compared with benign RR-MS. The T/T genotype of the G98T SNP is likely to confer an increased risk to develop MS. The A561C polymorphism seems to act as protective factor towards the progression to SP-MS.

Adenine Nucleotides↗

Influence of the Glu298Asp polymorphism of NOS3 on age at onset and homocysteine levels in AD patients.

The distribution of the Glu298Asp polymorphism in NOS3 gene was determined in 405 Italian patients with "probable" Alzheimer's disease (AD) compared with 253 age-matched controls. Total plasma homocysteine (tHcy) levels were evaluated in 97 patients and 23 controls, and were correlated with the Glu298Asp genotype. A significantly increased frequency of the Glu/Glu genotype in late onset AD (LOAD) patients was found. tHcy levels were significantly increased in patients compared with controls and, notably, higher in LOAD than in early onset AD (EOAD). Stratifying by the Glu298Asp genotype, a trend toward an increase of tHcy was present in Glu/Glu homozygous. This wild type genotype seems to be associated with LOAD. tHcy levels are significantly increased in AD compared with controls and, moreover, higher in LOAD than in EOAD, possibly in correlation with the microvascular disease occurring with aging. Besides, a contribution of the Glu/Glu genotype in increasing tHcy levels has been observed.

Age Distribution↗

CCR2-64I polymorphism and CCR5Delta32 deletion in patients with Alzheimer's disease.

Monocyte chemoattractant protein-1 (MCP-1) and RANTES, as well as their related receptors, have been shown to be involved in Alzheimer's disease (AD) pathogenesis. Genes for their related receptors, CCR2 and CCR5, respectively, are characterized by the presence of two polymorphisms: a conservative change of a valine with an isoleucine at codon 64 of CCR2 (CCR2-64I) and a 32-bp deletion in the coding region of CCR5 (CCR5Delta32), which leads to the expression of a nonfunctional receptor. The distribution of the CCR2-64I and CCR5Delta32 polymorphisms was determined in 290 AD patients and in 222 controls. A decreased frequency and an absence of homozygous for the polymorphism CCR2-64I were found, thus suggesting a protective effect of the mutated allele on the occurrence of AD. However, these findings must be cautiously interpreted as the overall significance was found without adjustment for multiple comparisons and is coming from the complete absence of the genotype 64I/64I in AD patients. Conversely, no different distribution of the CCR5Delta32 deletion in the two populations was shown. Stratifying by the presence of ApoE varepsilon4 allele, gender or age at onset, no differences in either allele frequencies were observed.

Adult↗