Elena Cellini

Meta-analysis of the Association Between Variants in SORL1 and Alzheimer Disease

OBJECTIVE To reexamine the association between the neuronal sortilin-related receptor gene (SORL1) and Alzheimer disease (AD). DESIGN Comprehensive and unbiased meta-analysis of all published and unpublished data from case-control studies for the SORL1 single-nucleotide polymorphisms (SNPs) that had been repeatedly assessed across studies. SETTING Academic research institutions in the United States, the Netherlands, Canada, Belgium, the United Kingdom, Singapore, Japan, Sweden, Germany, France, and Italy. PARTICIPANTS All published white and Asian case-control data sets, which included a total of 12,464 cases and 17,929 controls. MAIN OUTCOME MEASURES Alzheimer disease according to the Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) and the National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimers Disease and Related Disorders Association (now known as the Alzheimers Association). RESULTS In the white data sets, several markers were associated with AD after correction for multiple testing, including previously reported SNPs 8, 9, and 10 (P < .001). In addition, the C-G-C haplotype at SNPs 8 through 10 was associated with AD risk (P < .001). In the combined Asian data sets, SNPs 19 and 23 through 25 were associated with AD risk (P < .001). The disease-associated alleles at SNPs 8, 9, and 10 (120,873,131-120,886,175 base pairs [bp]; C-G-C alleles), at SNP 19 (120,953,300 bp; G allele), and at SNPs 24 through 25 (120,988,611 bp; T and C alleles) were the same previously reported alleles. The SNPs 4 through 5, 8 through 10, 12, and 19 through 25 belong to distinct linkage disequilibrium blocks. The same alleles at SNPs 8 through 10 (C-G-C), 19 (G), and 24 and 25 (T and C) have also been associated with AD endophenotypes, including white matter hyperintensities and hippocampal atrophy on magnetic resonance imaging, cerebrospinal fluid measures of amyloid β-peptide 42, and full-length SORL1 expression in the human brain. CONCLUSION This comprehensive meta-analysis provides confirmatory evidence that multiple SORL1 variants in distinct linkage disequilibrium blocks are associated with AD.

Association of BDNF with restricting anorexia nervosa and minimum body mass index: a family-based association study of eight European populations

Eating disorders (ED), such as anorexia nervosa (AN) and bulimia nervosa (BN), are complex psychiatric disorders where different genetic and environmental factors are involved. Several lines of evidence support that brain-derived neurotrophic factor (BDNF) plays an essential role in eating behaviour and that alterations on this neurotrophic system participates in the susceptibility to both AN and BN. Accordingly, intraventricular administration of BDNF in rats determines food starvation and body weight loss, while BDNF or its specific receptor NTRK2 knockout mice develop obesity and hyperphagia. Case–control studies also suggest a BDNF contribution in the aetiology of ED: we have previously reported a strong association between the Met66 variant within the BDNF gene, restricting AN (ANR) and minimum body mass index (minBMI) in a Spanish sample, and a positive association between the Val66Met and −270C/T BDNF SNPs and ED in six different European populations. To replicate these results, avoiding population stratification effects, we recruited 453 ED trios from eight European centres and performed a family-based association study. Both haplotype relative risk (HRR) and haplotype-based haplotype relative risk (HHRR) methods showed a positive association between the Met66 allele and ANR. Consistently, we also observed an effect of the Met66 variant on low minBMI and a preferential transmission of the −270C/Met66 haplotype to the affected ANR offspring. These results support the involvement of BDNF in eating behaviour and further suggest its participation in the genetic susceptibility to ED, mainly ANR and low minBMI.

5-HT2A receptor gene polymorphism and eating disorders.

Recent studies have reported a genetic association between the -1438 G/A polymorphism within the promoter region of the 5-HT(2A) receptor gene and eating disorders (ED), with conflicting results. To clarify the role of the -1438 G/A polymorphism in different ED categories we have analyzed the genotype and allele frequency distribution in 54 Italian patients with Binge ED (BED) compared to 132 obese non-BED subjects. No significant differences were found between obese BED and obese non-BED individuals, suggesting that this polymorphism does not genetically distinguish these two phenotypes. Moreover, the evaluation of 148 patients with anorexia nervosa and 86 patients with bulimia nervosa revealed an association of the A allele with both these disorders.

Cholesteryl ester transfer protein (CETP) I405V polymorphism and longevity in Italian centenarians.

A common polymorphism (I405V) in exon 14 of the cholesteryl ester transfer protein (CETP) gene has been recently associated to healthy aging in Ashkenazi Jewish. In order to study this genetic effect in long-lived individuals with a different ethnicity, we analyzed the allele and genotype distributions of the CETP polymorphism a sample of Italian centenarians. Our result does not confirm the association between the I405V CETP variation and the healthy aging phenotype described in the Ashkenazi Jewish population and suggests that other gene environment interactions contribute to longevity.

Present and lifetime comorbidity of tobacco, alcohol and drug use in eating disorders: A European multicenter study

OBJECTIVES To assess the differences in comorbid lifetime and current substance use (tobacco, alcohol and drug use) between eating disorder (ED) patients and healthy controls in five different European countries. METHOD A total of 1664 participants took part in the present study. ED cases (n=879) were referred to specialized ED units in five European countries. The ED cases were compared to a balanced control group of 785 healthy individuals. ASSESSMENT Participants completed the Substance Use Subscale of the Cross Cultural (Environmental) Questionnaire (CCQ), a measure of lifetime tobacco, alcohol and drug use. In the control group, also the GHQ-28, the SCID-I interview and the EAT-26 were used. RESULTS ED patients had higher lifetime and current tobacco and general drug use. The only non-significant result was obtained for lifetime and current alcohol use. Significant differences across ED subdiagnoses and controls also emerged, with BN and AN-BP generally presenting the highest and AN-R and controls the lowest rates. The only exception was detected for alcohol use where EDNOS demonstrated the highest values. Only a few cultural differences between countries emerged. CONCLUSIONS With the exception of alcohol consumption, tobacco and drug use appear to be more prevalent in ED patients than healthy controls. The differential risk observed in patients with bulimic features might be related to differences in temperament or might be the result of increased sensitivity to reward.

Brain-derived neurotrophic factor, apolipoprotein E genetic variants and cognitive performance in Alzheimer's disease.

Since greater attention has been paid to the direct link of genetic variation to cognition and memory performance, apolipoprotein E (ApoE) and brain-derived neurotrophic factor (BDNF) have been the two most frequently studied genes. To investigate the effect of BDNF and ApoE polymorphisms on the cognitive profile of mild-moderate Alzheimers disease (AD) cases, AD patients, genotyped for ApoE and BDNF polymorphisms, underwent extensive neuropsychological investigation. The effect of either ApoE epsilon4 allele and BDNF genetic variant on the neuropsychological pattern of mental impairment was examined both in terms of group differences in performance on the neuropsychological tests between carriers and non-carriers of each variant and by selecting the best predictor of cognitive performance among demographic and genetic factors by means of a multiple regression analysis. Our data confirm a specific effect caused by the presence and amount of ApoE epsilon4 allele, while they suggest that BDNF genetic variants are not a susceptibility factor to AD.

Alzheimer’s Disease: Role of Size and Location of White Matter Changes in Determining Cognitive Deficits

This study investigated the contribution that white matter changes (WMCs) make to clinical and cognitive features in Alzheimer’s disease (AD), independently ofpossible confounders such as cortical atrophy and the apolipoprotein E genotype as well as their relationship to vascular risk factors. We semiquantitatively assessed the degree and location of WMCs (global, periventricular and deep white matter), lacunes and global atrophy on brain MRI scans of 86 AD cases, extensively evaluated from a clinical and neuropsychological point of view. Multivariate logistic and linear regression analysis showed that age was the only significant predictor of all WMC measures and revealed a significant association of periventricular WMCs with performance on executive function tasks as well as of deep WMCs with history of mood depression. Our results underline the significance of WMC location over size in the occurrence of specific cognitive deficits in AD.

Immunoproteasome LMP2 60HH variant alters MBP epitope generation and reduces the risk to develop multiple sclerosis in Italian female population

Background Albeit several studies pointed out the pivotal role that CD4+T cells have in Multiple Sclerosis, the CD8+ T cells involvement in the pathology is still in its early phases of investigation. Proteasome degradation is the key step in the production of MHC class I-restricted epitopes and therefore its activity could be an important element in the activation and regulation of autoreactive CD8+ T cells in Multiple Sclerosis. Methodology/Principal Findings Immunoproteasomes and PA28-αβ regulator are present in MS affected brain area and accumulated in plaques. They are expressed in cell types supposed to be involved in MS development such as neurons, endothelial cells, oligodendrocytes, macrophages/macroglia and lymphocytes. Furthermore, in a genetic study on 1262 Italian MS cases and 845 controls we observed that HLA-A*02+ female subjects carrying the immunoproteasome LMP2 codon 60HH variant have a reduced risk to develop MS. Accordingly, immunoproteasomes carrying the LMP2 60H allele produce in vitro a lower amount of the HLA-A*0201 restricted immunodominant epitope MBP111–119. Conclusion/Significance The immunoproteasome LMP2 60HH variant reduces the risk to develop MS amongst Italian HLA-A*02+ females. We propose that such an effect is mediated by the altered proteasome-dependent production of a specific MBP epitope presented on the MHC class I. Our observations thereby support the hypothesis of an involvement of immunoproteasome in the MS pathogenesis.

Low social interactions in eating disorder patients in childhood and adulthood: A multi-centre European case control study

The objective of this article was to examine lifestyle behaviours in eating disorder (ED) patients and healthy controls. A total of 801 ED patients and 727 healthy controls from five European countries completed the questions related to lifestyle behaviours of the Cross-Cultural Questionnaire (CCQ). For children, the ED sample exhibited more solitary activities (rigorously doing homework [p<0.001] and watching TV [p<0.05] and less socializing with friends [p<0.05]) than the healthy control group and this continued in adulthood. There were minimal differences across ED sub-diagnoses and various cross-cultural differences emerged. Reduced social activities may be an important risk and maintaining factor for ED symptomatology.

Combined family trio and case-control analysis of the COMT Val158Met polymorphism in European patients with anorexia nervosa.

The high activity Val158 (H) allele of the dopamine‐metabolizing enzyme catechol‐O‐methyltransferase (COMT) was associated with anorexia nervosa (AN) in a recent family trio‐based study of patients from Israel. In an attempt to replicate this finding, we performed a combined family trio and case‐control study in an European population from seven centers in six different countries (Austria, Germany, Great Britain, Italy [Milan], Italy [Florence], Slovenia, and Spain), together contributing a total of 372 family trios, 684 controls and 266 cases. TDT analyses of high (H) and low (L) alleles in family trios showed that H allele and L allele were each transmitted 101 times (χ2 = 0, ns). Allele‐wise case‐control analysis using separate samples simply combined from the centers was also not significant, with the frequencies of the H allele 50% in cases and same in controls. Stratified analysis of data from all centers gave an odds ratio of 0.98 (Cornfield 95% confidence limits 0.78–1.24). Analysis by genotype was likewise not significant (overall χ2 = 0.42). Because we were not able to support the primary hypothesis that Val158Met is a risk factor for AN, we did not perform secondary analysis of minimum body mass index (mBMI), age at onset or illness subtype (restricting or binge purging anorexia). Overall we found no support for the hypothesis that the Val158 allele of COMT gene is associated with AN in our combined European sample.