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Agosta F.,San Raffaele Scientific Institute | Libera D.D.,San Raffaele Scientific Institute | Spinelli E.G.,San Raffaele Scientific Institute | Finardi A.,San Raffaele Scientific Institute | And 11 more authors.
Annals of Neurology

Objectives: We have described cerebrospinal fluid (CSF) myeloid microvesicles (MVs) as a marker of microglia activation during neuroinflammation in Alzheimer disease (AD), and characterized their ability to produce toxic amyloid β1-42 (Aβ1-42 ) oligomers from aggregated or soluble substrate. The aim of this study is to investigate the association of CSF myeloid MVs with neuroimaging, clinical, and paraclinical data in AD and mild cognitive impairment (MCI).Methods: We collected CSF from 106 AD patients, 51 MCI patients, and 29 neurologically healthy controls. We examined CSF myeloid MV content and AD markers. A subgroup of 34 AD and 21 MCI patients underwent structural and diffusion tensor MRI.Results: Higher levels of myeloid MVs were found in the CSF of AD patients and MCI patients converting within 3 years relative to controls, but also, at a lower level, in MCI patients not converting to AD. CSF myeloid MVs were associated with Tau but not with Aβ 1-42 CSF levels. CSF MVs levels correlated with white matter (WM) tract damage in MCI, and with hippocampal atrophy in AD.Interpretation: Microglial MVs are neurotoxic and myelinotoxic in the presence of Aβ1-42 . CSF myeloid MVs, mirroring microglia activation and MV release, are associated with WM damage in MCI and hippocampal atrophy in AD. This suggests that hippocampal microglia activation, in the presence of Aβ1-42 in excess, produces neurotoxic and oligodendrotoxic oligomers that, through WM tract damage, spread disease to neighboring and connected areas, causing local microglia activation and propagation of disease through the same sequence of events. ©2014 American Neurological Association 813 Acknowledgment. Source

Galluzzi S.,Irccs Istituto Centro San Giovanni Of Dio Fatebenefratelli | Geroldi C.,Alzheimers Unit | Amicucci G.,Service of Anesthesiology | Bocchio-Chiavetto L.,Neuropsychopharmacology Unit | And 7 more authors.
Journal of Neurology

The aim of this study is to support the use of biomarkers in the diagnosis of mild cognitive impairment (MCI) due to Alzheimer’s disease (AD) according to the revised NIA-AA diagnostic criteria. We compared clinical features and conversion to AD and other dementias among groups of MCI patients with different abnormal biomarker profiles. In this study, we enrolled 58 patients with MCI, and for each of them AD biomarkers (CSF Abeta42 and tau, temporoparietal hypometabolism on 18F-FDG PET, and hippocampal volume) were collected. Patients were divided into three groups: (i) no abnormal biomarker, (ii) AD biomarker pattern (including three subgroups of early = only abnormal Abeta42, intermediate = abnormal Abeta42 and FDG PET or tau, and late = abnormal Abeta42, FDG PET or tau, and HV), and (iii) any other biomarker combination. MCI patients with AD biomarker pattern had lower behavioural disturbances than patients with any other biomarker combination (p<0.0005). This group also showed lower performance on verbal and nonverbal memory than the other two groups (p = 0.07 and p = 0.004, respectively). Within the three subgroups with AD biomarker patterns we observed a significant trend toward a higher rate of conversion to dementia (p for trend = 0.006). With regard to dementia conversion, 100 % of patients with an AD biomarker pattern developed AD, but none of the patients with no abnormal biomarker and 27 % of patients with any other biomarker combination (p = 0.002) did so. We also described some clinical cases representative for each of these three groups. The results of this study provide evidence in favour of the use of biomarkers for the diagnosis of MCI due to AD, in line with recently published research criteria. © Springer-Verlag Berlin Heidelberg 2012. Source

Aas M.,University of Oslo | Haukvik U.K.,University of Oslo | Djurovic S.,University of Oslo | Tesli M.,University of Oslo | And 8 more authors.
Journal of Psychiatric Research

Objective: Here we investigated a two hit gene environment model in relation to functional genomic factors (BDNF mRNA), and volume of hippocampal subfields in schizophrenia spectrum and bipolar disorders, focusing on both an environmental (childhood trauma) and genetic risk factor (BDNF val66met). Method: A total of 323 patients with a broad DSM-IV schizophrenia spectrum disorder or bipolar disorder were consecutively recruited. A history of childhood trauma was obtained using the Childhood Trauma Questionnaire. BDNF DNA and RNA were analyzed using standardized procedures. A subsample of n=108 underwent MRI scanning, and the FreeSurfer was used to obtain measures of hippocampal subfield. All MRI data were corrected for age and gender, with post-hoc analysis correcting for ICV. Results: A history of childhood trauma or being a met carrier of the BDNF val66met was associated with significantly reduced BDNF mRNA level. Additive effects were observed between a history of childhood trauma and BDNF val66met, in the direction of met carriers with high levels of childhood trauma having the lowest BDNF mRNA levels. Lastly, met carriers reporting high levels of childhood trauma (specifically sexual or physical abuse) had significantly reduced hippocampal subfield volumes CA2/3 and CA4 dentate gyrus. Conclusion: The current findings demonstrate that the reduced BDNF mRNA levels found in psychosis may be associated with both a history of childhood trauma and BDNF val66met variants. Further, our study supports a two hit model including a history of childhood trauma as well as genetic vulnerability (met carriers of the BDNF val66met) behind reduced volume of hippocampal subfields in psychosis. This was specifically found for areas important for neurogenesis, the CA2/3and the CA4 DG. © 2014 Elsevier Ltd. All rights reserved. Source

Bocchio-Chiavetto L.,Neuropsychopharmacology Unit | Bagnardi V.,University of Milan Bicocca | Bagnardi V.,Italian National Cancer Institute | Zanardini R.,Neuropsychopharmacology Unit | And 10 more authors.
World Journal of Biological Psychiatry

Objectives. Alterations of BDNF signalling in major depression (MD) are supported by studies demonstrating decreased levels of the neurotrophin serum and plasma content in MD patients. We conducted a replication study and we performed two meta-analyses on studies analysing serum and plasma BDNF levels in MD patients. Methods. The samples were composed by 489 patients/483 controls for the meta-analysis on serum and by 161 patients/211 controls for that on plasma levels. We performed also subgroup analyses to examine whether the decrease in BDNF levels in MD was influenced by gender. Results. In the replication study we found decreased serum BDNF levels in MD patients (P<0.01) and we demonstrated that is down-regulated the mature form of the neurotrophin (mBDNF). No significant difference was evidenced for plasma BDNF levels. The meta-analyses showed a reduction of both BDNF serum (P<0.0001) and plasma levels (P=0.02) in MD. No difference in the effect size on serum BDNF was observed between males and females (P=0.18). Conclusions. In conclusion, our results provide evidence of peripheral BDNF alteration in MD and support the rationale for further investigation aiming to the identification of biomarkers for differential diagnosis and personalization of therapies in this disorder. © 2010 Informa UK Ltd. Source

Minelli A.,Genetic Unit | Zanardini R.,Neuropsychopharmacology Unit | Bonvicini C.,Genetic Unit | Sartori R.,University of Verona | And 4 more authors.
European Archives of Psychiatry and Clinical Neuroscience

Consisting evidence in animal models has suggested that alterations in brain-derived neurotrophic factor (BDNF) brain expression and release are involved in the pathogenesis of mental illnesses, such as, mood, anxiety, and eating disorders. This hypothesis is supported by data emerging from biochemical studies on serum BDNF levels and genetic studies on the functional polymorphism Val66Met in the BDNF gene in patients and control subjects. Anxiety-related personality traits are associated with several mental disorders. However, they are also measurable in non-affected subjects and, so, may represent a useful "endophenotype" to study the biological correlation of the vulnerability factors in the general population. In this study, we analyzed putative correlations in subjects unaffected by mental disorders between personality traits, serum BDNF levels (N = 107), and the BDNF Val66Met genotype (N = 217). Furthermore, we tested the possible interactions between these variables. A significant correlation has been observed between high scores of harm avoidance (HA) measured by the temperament and character inventory (TCI), and low BDNF serum concentration (r = -0.253, P = 0.009). In addition, an association has been evidenced between low BDNF levels in serum and the BDNF Val/Val genotype (P = 0.021). By analyzing putative concomitant effects of different variables on HA scores in a regression model, we observed a significant correlation only with BDNF serum concentrations (P = 0.022). The study results suggest that a decrease in serum BDNF concentrations may represent a biochemical marker associated with anxiety personality traits also retrievable in the general population. © 2011 Springer-Verlag. Source

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