Using integrated meta-omics to appreciate the role of the gut microbiota in epilepsy.

The way the human microbiota may modulate neurological pathologies is a fascinating matter of research. Epilepsy is a common neurological disorder, which has been largely investigated in correlation with microbiota health and function. However, the mechanisms that regulate this apparent connection are scarcely defined, and extensive effort has been conducted to understand the role of microbiota in preventing and reducing epileptic seizures. Intestinal bacteria seem to modulate the seizure frequency mainly by releasing neurotransmitters and inflammatory mediators. In order to elucidate the complex microbial contribution to epilepsy pathophysiology, integrated meta-omics could be pivotal. In fact, the combination of two or more meta-omics approaches allows a multifactorial study of microbial activity within the frame of disease or drug treatments. In this review, we provide information depicting and supporting the use of multi-omics to study the microbiota-epilepsy connection. We described different meta-omics analyses (metagenomics, metatranscriptomics, metaproteomics and metabolomics), focusing on current technical challenges in stool collection procedures, sample extraction methods and data processing. We further discussed the current advantages and limitations of using the integrative approach of multi-omics in epilepsy investigations.

Technological tools and strategies for culturing human gut microbiota in engineered in vitro models.

The gut microbiota directly impacts the pathophysiology of different human body districts. Consequently, microbiota investigation is an hot topic of research and its in vitro culture has gained extreme interest in different fields. However, the high sensitivity of microbiota to external stimuli, such as sampling procedure, and the physicochemical complexity of the gut environment make its in vitro culture a challenging task. New engineered microfluidic gut-on-a-chip devices have the potential to model some important features of the intestinal structure, but they are usually unable to sustain culture of microbiota over an extended period of time. The integration of gut-on-a-chip devices with bioreactors for continuous bacterial culture would lead to fast advances in the study of microbiota-host crosstalk. In this review, we summarize the main technologies for the continuous culture of microbiota as upstream systems to be coupled with microfluidic devices to study bacteria-host cells communication. The engineering of integrated microfluidic platforms, capable of sustaining both anaerobic and aerobic cultures, would be the starting point to unveil complex biological phenomena proper of the microbiota-host crosstalks, paving to way to multiple research and technological applications.

Increased transcription of transglutaminase 1 mediates neuronal death in in vitro models of neuronal stress and Aß1-42-mediated toxicity.

Alzheimer's disease (AD) is the most common cause of dementia. At the pre-symptomatic phase of the disease, the processing of the amyloid precursor protein (APP) produces toxic peptides, called amyloid-ß 1-42 (Aß 1-42). The downstream effects of Aß 1-42 production are not completely uncovered. Here, we report the involvement of transglutaminase 1 (TG1) in in vitro AD models of neuronal toxicity. TG1 was increased at late stages of the disease in the hippocampus of a mouse model of AD and in primary cortical neurons undergoing stress. Silencing of TGM1 gene was sufficient to prevent Aß-mediated neuronal death. Conversely, its overexpression enhanced cell death. TGM1 upregulation was mediated at the transcriptional level by an activator protein 1 (AP1) binding site that when mutated halted TGM1 promoter activation. These results indicate that TG1 acts downstream of Aß-toxicity, and that its stress-dependent increase makes it suitable for pharmacological intervention.

Association between Sirtuin 1 Gene rs10997870 Polymorphism and Suicide Behaviors in Bipolar Disorder.

BACKGROUND/AIMS: Suicidal behavior (SB) in bipolar disorder (BD) is a complex multifactorial event resulting from an interaction of genetic, neurobiological and psychosocial factors. Recent studies identified new possible mechanisms, suggesting a role for sirtuins (SIRTs 1-7), a family of nicotinamide adenine dinucleotide-dependent enzymes with a multifaceted role in the central nervous system. The aims of the present study were: (1) to investigate the effects of the rs10997870 SIRT1 gene variant on SB in BD; (2) to explore the effects of the same gene variant on specific depressive symptoms at the severest episode. METHODS: One hundred and eighty DSM-IV bipolar outpatients were enrolled in a naturalistic cohort study. The rs10997870 polymorphism within the SIRT1 gene was analyzed. RESULTS: An association between the GG genotype and SB was detected (lifetime: p = 0.015). Compared to other genotypes, GG carriers presented more frequently psychomotor agitation (p = 0.009) and a higher Hamilton Depression Rating Scale total score (p = 0.014) at the severest depressive episode. SB and psychomotor agitation were found to be associated with GG carriers and G allele in a multivariate analysis as well. CONCLUSION: Our findings suggest a role of the rs10997870 SIRT1 gene variant in SB amongst BD patients and its association with specific depressive symptoms. Despite a number of limitations of this exploratory study, our results may provide new insight into the mechanisms underlying SB in BD.

Clinical and genetic factors associated with suicide in mood disorder patients.

Suicidality is a continuum ranging from ideation to attempted and completed suicide, with a complex etiology involving both genetic heritability and environmental factors. The majority of suicide events occur in the context of psychiatric conditions, preeminently major depression and bipolar disorder. The present study investigates clinical factors associated with suicide in a sample of 553 mood disorder patients, recruited within the 'Psy Pluriel' center, Centre Européen de Psychologie Médicale, and the Department of Psychiatry of Erasme Hospital (Brussels). Furthermore, genetic association analyses examining polymorphisms within COMT, BDNF, MAPK1 and CREB1 genes were performed in a subsample of 259 bipolar patients. The presence or absence of a previous suicide attempt and of current suicide risk were assessed. A positive association with suicide attempt was reported for younger patients, females, lower educated, smokers, those with higher scores on depressive symptoms and higher functional disability and those with anxiety comorbidity and familial history of suicidality in first- and second-degree relatives. Anxiety disorder comorbidity was the stronger predictor of current suicide risk. No associations were found with polymorphisms within COMT and BDNF genes, whereas significant associations were found with variations in rs13515 (MAPK1) and rs6740584 (CREB1) polymorphisms. From a clinical perspective, our study proposes several clinical characteristics, such as increased depressive symptomatology, anxiety comorbidity, functional disability and family history of suicidality, as correlates associated with suicide. Genetic risk variants in MAPK1 and CREB1 genes might be involved in a dysregulation of inflammatory and neuroplasticity pathways and are worthy of future investigation.

[Efficacy of educational intervention for patients wearing peripherall inserted central catheter. A pilot study]. / Efficacia di un intervento educativo rivolto ai pazienti portatori di un catetere venoso centrale ad inserzione periferica: studio pilota.

BACKGROUND: Peripherally Inserted Central Catheter (PICC) is a central venous catheter suitable for patients who receive chemotherapy in Day Hospital regimen. The patient must be educated to a proper home management of the PICC through targeted education. AIM: To evaluate the effectiveness of a targeted educational intervention through the comparison of: indi- vidual interview, brochure paper, informative video. METHOD: Single-centre randomized controlled clinical trial with a simple three-arm comparative scheme. The study population is represented by all patients undergoing the insertion of PICC at the Oncological Day Hospital and Breast Unit in the observation period between October 2013 and February 2014. The Standard educational session is performed by the nurse positioning the PICC. PICC team consists of two nurses in possession of the first level master in venous access management. Following randomization eligible patients were divided in three groups: group A received Standard educational session; group B received the standard information and the brochure; group C received the stan- dard information and the informative video. The level of the achieved knowledge was investigated by administering targeted questionnaires. RESULTS: A total of 40 patients joined the study: a convenience sample represented by people between the ages of 18 and 75 years, in outpatient care. Statistically significant difference in key areas necessary for the proper management of PICC: when to change the dressing (p=0.001), when to wash the catheter (p=0), how to recognize signs and symptoms of infection (p=0.001), identify at-risk behaviors (p=0.005), when carrying out the inspection of the catheter's insertion site (p=0). CONCLUSIONS: The administration of a multimedial educational tool was found to be superior in efficacy compared to the only Standard educational session to increase patient's knowledges. The video appears to be more effective than the brochure. The obtained results are influenced by the small sample size and by the shortness of the follow up timing; this leads to a low generalizability of the conclusions.

Bronchial Progenitor Cells in Obstructive and Neoplastic Lung Disease: A Pilot Study.

The alteration of progenitor/stem cells present in the airway epithelium has been observed in patients with COPD. Smoking exposure induces remodeling patterns in bronchial progenitor cells (BPCs), encompassing squamous metaplasia, hyperplasia of basal and of mucus-secreting cells, and the depletion of ciliated and non-mucous secretory cells. Our aim was to assess the expression of p63 and vimentin as potential markers of airway remodeling and the regulation of stem cell populations in obstructive and neoplastic lung disease patients. A retrospective single-center observational study was conducted, including patients undergoing bronchoscopy with bronchial biopsies for suspected lung cancer. p63 and vimentin expression were evaluated via immunohistochemical analysis. There were 25 patients, of which 21 with COPD were included, and 17 were diagnosed with lung cancer. We observed that FEV1% was negatively correlated with p63+ basal cell number (r = -0.614, p = 0.019) and positively correlated with vimentin expression (r = 0.670; p = 0.008). p63 was significantly higher in biopsies from the trachea and main bronchi compared to more distal areas (p = 0.040), whereas vimentin was prevalent in the more distal areas (p = 0.042). Our preliminary data suggest the initial evidence of structural changes in BPCs among patients with COPD and lung cancer. Further research efforts are warranted to investigate additional morphologic and functional respiratory parameters in these patients.

The microbiota-gut-brain axis and epilepsy from a multidisciplinary perspective: Clinical evidence and technological solutions for improvement of in vitro preclinical models.

Epilepsy is a common neurological disease characterized by the enduring predisposition of the brain to generate seizures. Among the recognized causes, a role played by the gut microbiota in epilepsy has been hypothesized and supported by new investigative approaches. To dissect the microbiota-gut-brain (MGB) axis involvement in epilepsy, in vitro modeling approaches arouse interest among researchers in the field. This review summarizes, first of all, the evidence of a role of the MGB axis in epilepsy by providing an overview of the recent clinical and preclinical studies and showing how dietary modification, microbiome supplementations, and hence, microbiota alterations may have an impact on seizures. Subsequently, the currently available strategies to study epilepsy on animal and in vitro models are described, focusing attention on these latter and the technological challenges for integration with already existing MGB axis models. Finally, the implementation of existing epilepsy in vitro systems is discussed, offering a complete overview of the available technological tools which may improve reliability and clinical translation of the results towards the development of innovative therapeutic approaches, taking advantage of complementary technologies.

CSF cutoffs for MCI due to AD depend on APOEε4 carrier status.

Amyloid and tau pathological accumulation should be considered for Alzheimer's disease (AD) definition and before subjects' enrollment in disease-modifying trials. Although age, APOEε4, and sex influence cerebrospinal fluid (CSF) biomarker levels, none of these variables are considered by current normality/abnormality cutoffs. Using baseline CSF data from 2 independent cohorts (PharmaCOG/European Alzheimer's Disease Neuroimaging Initiative and Alzheimer's Disease Neuroimaging Initiative), we investigated the effect of age, APOEε4 status, and sex on CSF Aß42/P-tau distribution and cutoff extraction by applying mixture models with covariates. The Aß42/P-tau distribution revealed the presence of 3 subgroups (AD-like, intermediate, control-like) and 2 cutoffs. The identification of the intermediate subgroup and of the higher cutoff was APOEε4 dependent in both cohorts. APOE-specific classification (higher cutoff for APOEε4+, lower cutoff for APOEε4-) showed higher diagnostic accuracy in identifying MCI due to AD compared to single Aß42 and Aß42/P-tau cutoffs. APOEε4 influences amyloid and tau CSF markers and AD progression in MCI patients supporting i) the use of APOE-specific cutoffs to identify MCI due to AD and ii) the utility of considering APOE genotype for early AD diagnosis.

Asymptomatic Carriers of Presenilin-1 E318G Variant Show no Cerebrospinal Fluid Biochemical Signs Suggestive of Alzheimer's disease in a Family with Late-onset Dementia.

BACKGROUND: Presenilin-1 (PSEN-1) is a component of the γ-secretase complex involved in ß-amyloid Precursor Protein (AßPP) processing. Usually, Alzheimer's disease (AD)-linked mutations in the PSEN-1 gene lead to the early onset and increase the production of the aggregation-prone peptide Aß42. However, the PSEN-1 E318G variant has an unclear pathogenic role and is recently reported as a genetic risk factor for AD. In particular, E318G variant presence correlated with increased cerebrospinal fluid (CSF) levels of Total Tau (t-tau) and Phosphorylated Tau (p-tau). OBJECTIVE: We describe a large Italian family, which we followed from January 2003 to January 2018, with the late-onset AD and the E318G variant, with the aim of assessing E318G-associated CSF or plasma biochemical changes in biomarkers of dementia. METHOD: CSF Aß42, t-tau and p-tau, plasma Aß42 and Aß40 were assessed by ELISA tests, while CSF amyloid peptides profile was investigated by mass spectrometry. RESULTS: We did not find any changes in CSF biochemical markers (Aß42, t-tau, p-tau and amyloid peptides) of asymptomatic E318G carriers in 2010 and 2012, but plasma Aß40 was increased at the same times. From 2003 to 2018, no asymptomatic E318G carrier developed AD. CONCLUSION: Our follow-up of this family may help elucidate E318G's role in AD and globally points to a null effect of this variant.

Merging memantine and ferulic acid to probe connections between NMDA receptors, oxidative stress and amyloid-ß peptide in Alzheimer's disease.

N-methyl-d-aspartate receptors (NMDAR) are critically involved in the pathogenesis of Alzheimer's disease (AD). Acting as an open-channel blocker, the anti-AD drug memantine preferentially targets NMDAR overactivation, which has been proposed to trigger neurotoxic events mediated by amyloid ß peptide (Aß) and oxidative stress. In this study, we applied a multifunctional approach by conjugating memantine to ferulic acid, which is known to protect the brain from Aß neurotoxicity and neuronal death caused by ROS. The most interesting compound (7) behaved, like memantine, as a voltage-dependent antagonist of NMDAR (IC50 = 6.9 µM). In addition, at 10 µM concentration, 7 exerted antioxidant properties both directly and indirectly through the activation of the Nrf-2 pathway in SH-SY5Y cells. At the same concentration, differently from the parent compounds memantine and ferulic acid alone, it was able to modulate Aß production, as revealed by the observed increase of the non-amyloidogenic sAPPα in H4-SW cells. These findings suggest that compound 7 may represent a promising tool for investigating NMDAR-mediated neurotoxic events involving Aß burden and oxidative damage.

Plasma Aß42 as a Biomarker of Prodromal Alzheimer's Disease Progression in Patients with Amnestic Mild Cognitive Impairment: Evidence from the PharmaCog/E-ADNI Study.

It is an open issue whether blood biomarkers serve to diagnose Alzheimer's disease (AD) or monitor its progression over time from prodromal stages. Here, we addressed this question starting from data of the European FP7 IMI-PharmaCog/E-ADNI longitudinal study in amnesic mild cognitive impairment (aMCI) patients including biological, clinical, neuropsychological (e.g., ADAS-Cog13), neuroimaging, and electroencephalographic measures. PharmaCog/E-ADNI patients were classified as "positive" (i.e., "prodromal AD" n = 76) or "negative" (n = 52) based on a diagnostic cut-off of Aß42/P-tau in cerebrospinal fluid as well as APOE ε 4 genotype. Blood was sampled at baseline and at two follow-ups (12 and 18 months), when plasma amyloid peptide 42 and 40 (Aß42, Aß40) and apolipoprotein J (clusterin, CLU) were assessed. Linear Mixed Models found no significant differences in plasma molecules between the "positive" (i.e., prodromal AD) and "negative" groups at baseline. In contrast, plasma Aß42 showed a greater reduction over time in the prodromal AD than the "negative" aMCI group (p = 0.048), while CLU and Aß40 increased, but similarly in the two groups. Furthermore, plasma Aß42 correlated with the ADAS-Cog13 score both in aMCI patients as a whole and the prodromal AD group alone. Finally, CLU correlated with the ADAS-Cog13 only in the whole aMCI group, and no association with ADAS-Cog13 was found for Aß40. In conclusion, plasma Aß42 showed disease progression-related features in aMCI patients with prodromal AD.

Exome sequencing in an Italian family with Alzheimer's disease points to a role for seizure-related gene 6 (SEZ6) rare variant R615H.

BACKGROUND: The typical familial form of Alzheimer's disease (FAD) accounts for about 5% of total Alzheimer's disease (AD) cases. Presenilins (PSEN1 and PSEN2) and amyloid-ß (A4) precursor protein (APP) genes carry all reported FAD-linked mutations. However, other genetic loci may be involved in AD. For instance, seizure-related gene 6 (SEZ6) has been reported in brain development and psychiatric disorders and is differentially expressed in the cerebrospinal fluid of AD cases. METHODS: We describe a targeted exome sequencing analysis of a large Italian kindred with AD, negative for PSEN and APP variants, that indicated the SEZ6 heterozygous mutation R615H is associated with the pathology. RESULTS: We overexpressed R615H mutation in H4-SW cells, finding a reduction of amyloid peptide Aß(1-42). Sez6 expression decreased with age in a mouse model of AD (3xTG-AD), but independently from transgene expression. CONCLUSIONS: These results support a role of exome sequencing for disease-associated variant discovery and reinforce available data on SEZ6 in AD models.

Optimization of a 3D Dynamic Culturing System for In Vitro Modeling of Frontotemporal Neurodegeneration-Relevant Pathologic Features.

Frontotemporal lobar degeneration (FTLD) is a severe neurodegenerative disorder that is diagnosed with increasing frequency in clinical setting. Currently, no therapy is available and in addition the molecular basis of the disease are far from being elucidated. Consequently, it is of pivotal importance to develop reliable and cost-effective in vitro models for basic research purposes and drug screening. To this respect, recent results in the field of Alzheimer's disease have suggested that a tridimensional (3D) environment is an added value to better model key pathologic features of the disease. Here, we have tried to add complexity to the 3D cell culturing concept by using a microfluidic bioreactor, where cells are cultured under a continuous flow of medium, thus mimicking the interstitial fluid movement that actually perfuses the body tissues, including the brain. We have implemented this model using a neuronal-like cell line (SH-SY5Y), a widely exploited cell model for neurodegenerative disorders that shows some basic features relevant for FTLD modeling, such as the release of the FTLD-related protein progranulin (PRGN) in specific vesicles (exosomes). We have efficiently seeded the cells on 3D scaffolds, optimized a disease-relevant oxidative stress experiment (by targeting mitochondrial function that is one of the possible FTLD-involved pathological mechanisms) and evaluated cell metabolic activity in dynamic culture in comparison to static conditions, finding that SH-SY5Y cells cultured in 3D scaffold are susceptible to the oxidative damage triggered by a mitochondrial-targeting toxin (6-OHDA) and that the same cells cultured in dynamic conditions kept their basic capacity to secrete PRGN in exosomes once recovered from the bioreactor and plated in standard 2D conditions. We think that a further improvement of our microfluidic system may help in providing a full device where assessing basic FTLD-related features (including PRGN dynamic secretion) that may be useful for monitoring disease progression over time or evaluating therapeutic interventions.

Lovastatin fails to improve motor performance and survival in methyl-CpG-binding protein2-null mice.

Previous studies provided evidence for the alteration of brain cholesterol homeostasis in 129.Mecp2-null mice, an experimental model of Rett syndrome. The efficacy of statins in improving motor symptoms and prolonging survival of mutant mice suggested a potential role of statins in the therapy of Rett syndrome. In the present study, we show that Mecp2 deletion had no effect on brain and reduced serum cholesterol levels and lovastatin (1.5 mg/kg, twice weekly as in the previous study) had no effects on motor deficits and survival when Mecp2 deletion was expressed on a background strain (C57BL/6J; B6) differing from that used in the earlier study. These findings indicate that the effects of statins may be background specific and raise important issues to consider when contemplating clinical trials. The reduction of the brain cholesterol metabolite 24S-hydroxycholesterol (24S-OHC) found in B6.Mecp2-null mice suggests the occurrence of changes in brain cholesterol metabolism and the potential utility of using plasma levels of 24S-OHC as a biomarker of brain cholesterol homeostasis in RTT.

Sirtuin 2 Inhibition Improves Cognitive Performance and Acts on Amyloid-ß Protein Precursor Processing in Two Alzheimer's Disease Mouse Models.

The neuropathological hallmarks of Alzheimer's disease (AD) are extracellular plaques built up by the accumulation of the amyloid-ß protein precursor (AßPP)-derived peptide ß (Aß), and intracellular tangles of hyperphosphorylated tau protein. Sirtuin 2 (SIRT2) is a member of the sirtuin family, featuring conserved enzymes with deacetylase activity and involved in several cell molecular pathways. We investigated the importance of SIRT2 inhibition in AD. We inhibited SIRT2 by small molecules (AGK-2, AK-7) and examined AßPP metabolism in H4-SW neuroglioma cells overexpressing AßPP and two AD transgenic mouse models (3xTg-AD and APP23). The in vitro studies suggested that the inhibition of SIRT2 reduced Aß production; in vivo data showed an improvement of cognitive performance in the novel object recognition test, and an effect on AßPP proteolytic processing leading to a reduction of soluble ß-AßPP and an increase of soluble α-AßPP protein. In 3xTg-AD mice, we noticed that total tau protein level rose. Overall, our pre-clinical data support a role for SIRT2 inhibition in the improvement of cognitive performance and the modulation of molecular mechanisms relevant for AD, thus deserving attention as possible therapeutic strategy.

CHRNA7 Gene and Response to Cholinesterase Inhibitors in an Italian Cohort of Alzheimer's Disease Patients.

Previous studies suggest that genetic variants in CHRNA7, which encodes for the major subunit of the acetylcholine receptor (α7-nAChR), are associated with the clinical response to cholinesterase inhibitors (ChEI) in Alzheimer's disease (AD) patients. We sought to replicate the association of two SNPs in the CHRNA7 gene, rs6494223 and rs8024987, with response to ChEI treatment in an Italian cohort of 169 AD patients, further extending the study to gene-level analysis. None of the tested variants was associated with clinical response. However, rs6494223 showed a consistent effect direction (OR = 1.4; p = 0.17), which after meta-analysis with previous study yielded a significant result (OR = 1.57, p = 0.02, I2 = 0%).

Loss of exosomes in progranulin-associated frontotemporal dementia.

Many cells of the nervous system have been shown to release exosomes, a subclass of secreted vesicles of endosomal origin capable of transferring biomolecules among cells: this transfer modality represents a novel physiological form of intercellular communication between neural cells. Herein, we demonstrated that progranulin (PGRN), a protein targeted to the classical secretory pathway, is also secreted in association with exosomes by human primary fibroblasts. Moreover, we demonstrated that null mutations in the progranulin gene (GRN), a major cause of frontotemporal dementia, strongly reduce the number of released exosomes and alter their composition. In vitro GRN silencing in SHSY-5Y cells confirmed a role of PGRN in the control of exosome release. It is believed that depletion of PGRN in the brain might cause neurodegeneration in GRN-associated frontotemporal dementia. We demonstrated that, along with shortage of the circulating PGRN, GRN null mutations alter intercellular communication. Thus, a better understanding of the role played by exosomes in GRN-associated neurodegeneration is crucial for the development of novel therapies for these diseases.

The SIRT1 promoter polymorphic site rs12778366 increases IL-6 related human mortality in the prospective study "Treviso Longeva (TRELONG)".

Studies on sirtuins (SIRT), a family of proteins with deacetylase activity, have provided convergent evidence of the key role of these enzymes in aging-linked physiological functions. The link between SIRT1 and longevity has emerged in model organism but few data are available in humans, in particular relying on longitudinal studies. Here, we assessed whether a genetic variant within SIRT1 gene promoter (rs12778366) was associated to human longevity. We analyzed 586 genomic DNA (gDNA) collected in the study "Treviso Longeva" (TRELONG), including elderly over 70 years of age from the municipality of Treviso, a town in the Northeast of Italy, with a 11-year follow-up. We genotyped SIRT1 rs12778366 by real-time polymerase chain reaction (RT-PCR) allelic discrimination assay. A cross-sectional analysis performed by comparing people over and under 85 years of age did not evidence association between rs12778366 and longevity. When we performed a longitudinal analysis considering mortality as dependent variable, we did not observe an association of rs12778366 with longevity in the whole population (corrected P-value = 0.33). However, when we stratified the TRELONG subjects according to circulating level of interleukin-6 (IL-6), a predictor of disability and mortality, we found that rs12778366 (TC+CC) carriers were at increased risk of mortality in comparison to the TT reference group (corrected P-value = 0.03, HR 1.47). Our data do not support a major role of rs12778366 in human longevity, but the stratified analysis on IL-6 suggests that this variant may be involved in the detrimental effect of high circulating IL-6 in the elderly.