ABSTRACT
BACKGROUND: Liquid biopsies offer significant potential for informing on cancer progression and therapeutic resistance via minimally invasive serial monitoring of genetic alterations. Although the cancer epigenome is a central driving force in most neoplasia, the accuracy of monitoring the tumor methylome using liquid biopsies remains relatively unknown. OBJECTIVES: to investigate how well two types of liquid biopsy (urine and blood) capture the prostate cancer methylome, and may thus serve as a non-invasive surrogate for studying the tumor epigenome. METHODS: A cohort of four metastatic treatment naïve prostate cancer (PCa) patients was selected. Matched biopsy cores (tumor and histologically matched-normal), post-DRE, pre-biopsy urine, and peripheral blood plasma were available for each subject. DNA methylation was profiled utilizing the Infinium® MethylationEPIC BeadChip (Illumina) and analysed using the RnBeads software. Significantly (FDR adjusted P < 0.05) differentially methylated probes (DMPs) between tumor and MN were identified and examined in the liquids (done at a grouped and individual subject level). RESULTS: DNA methylation analysis of urine and blood in men with metastatic PCa showed highly correlated patterns between the different liquid types (ρ = 0.93, P < 0.0001), with large contributions from non-tumor sources. DNA methylation profiles of liquids were more similar between subjects, than intra-individual liquid-tumor correlations. Overall, both urine and plasma are viable surrogates for tumor tissue biopsies, capturing up to 39.40% and 64.14% of tumor-specific methylation alterations, respectively. CONCLUSION: We conclude that both urine and blood plasma are easily accessible and sensitive biofluids for the study of PCa epigenomic alterations.
Subject(s)
Biomarkers, Tumor/genetics , Epigenome , Prostatic Neoplasms/genetics , Aged , Biomarkers, Tumor/blood , Biomarkers, Tumor/urine , DNA Methylation , Humans , Liquid Biopsy/methods , Liquid Biopsy/standards , Male , Middle Aged , Prostatic Neoplasms/blood , Prostatic Neoplasms/pathology , Prostatic Neoplasms/urine , Sensitivity and SpecificityABSTRACT
Rationale: Open lung ventilation strategies have been recommended in patients with acute respiratory distress syndrome (ARDS).Objectives: To determine whether a maximal lung recruitment strategy reduces ventilator-free days in patients with ARDS.Methods: A phase II, multicenter randomized controlled trial in adults with moderate to severe ARDS. Patients received maximal lung recruitment, titrated positive end expiratory pressure and further Vt limitation, or control "protective" ventilation.Measurements and Main Results: The primary outcome was ventilator-free days at Day 28. Secondary outcomes included mortality, barotrauma, new use of hypoxemic adjuvant therapies, and ICU and hospital stay. Enrollment halted October 2, 2017, after publication of ART (Alveolar Recruitment for Acute Respiratory Distress Syndrome Trial), when 115 of a planned 340 patients had been randomized (57% male; mean age, 53.6 yr). At 28 days after randomization, there was no difference between the maximal lung recruitment and control ventilation strategies in ventilator-free days (median, 16 d [interquartile range (IQR), 0-21 d], n = 57, vs. 14.5 d [IQR, 0-21.5 d], n = 56; P = 0.95), mortality (24.6% [n = 14/56] vs. 26.8% [n = 15/56]; P = 0.79), or the rate of barotrauma (5.2% [n = 3/57] vs. 10.7% [n = 6/56]; P = 0.32). However, the intervention group showed reduced use of new hypoxemic adjuvant therapies (i.e., inhaled nitric oxide, extracorporeal membrane oxygenation, prone; median change from baseline 0 [IQR, 0-1] vs. 1 [IQR, 0-1]; P = 0.004) and increased rates of new cardiac arrhythmia (n = 17 [29%] vs. n = 7 [13%]; P = 0.03).Conclusions: Compared with control ventilation, maximal lung recruitment did not reduce the duration of ventilation-free days or mortality and was associated with increased cardiovascular adverse events but lower use of hypoxemic adjuvant therapies.Clinical trial registered with www.clinicaltrials.gov (NCT01667146).
Subject(s)
Respiration, Artificial/methods , Respiratory Distress Syndrome/therapy , Female , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Positive-Pressure Respiration/methods , Positive-Pressure Respiration/mortality , Respiration, Artificial/mortality , Respiratory Distress Syndrome/mortality , Survival AnalysisABSTRACT
BACKGROUND: Mechanical ventilation is a life-saving intervention that maintains gas exchange in patients with acute respiratory distress syndrome (ARDS); however, it is associated with high mortality and it may augment, or even initiate, lung injury. An open lung ventilation strategy that combines alveolar recruitment manoeuvres with individually titrated positive end-expiratory pressure (PEEP) and targeting lower tidal volumes, or driving pressures by a permissive approach to hypercapnia, may reduce the lung injury associated with mechanical ventilation. This protocol reports the rationale, study design and analysis plan of the Permissive Hypercapnia, Alveolar Recruitment and Low Airway Pressure (PHARLAP) trial. METHODS AND DESIGN: PHARLAP is a phase 2, international, multicentre, prospective, randomised, controlled, parallel-group clinical trial, which aims to determine if staircase alveolar recruitment and individually titrated PEEP, when combined with permissive hypercapnia and low airway pressures, increases ventilator-free days to Day 28 when compared with conventional mechanical ventilation (Acute Respiratory Distress Syndrome Clinical Network [ARDSNet] strategy) in patients with moderate to severe ARDS. This study will enrol 340 patients. The intervention group will receive daily staircase alveolar recruitment manoeuvres with incremental PEEP to a maximum of 40 cmH2O and peak pressures to a maximum of 55 cmH2O. PEEP will be titrated individually against peripheral oxygen saturation, targeting lower tidal volumes by a permissive approach to hypercapnia. In the control group, patients will receive mechanical ventilation following the ARDSNet-ARMA trial protocol, including PEEP titrated with a PEEP/fraction of inspired oxygen (FiO2) chart. Both groups will receive airway pressures ≤30 cmH2O and tidal volumes of ≤ 6 mL/kg predicted bodyweight or less. The primary outcome is ventilator-free days to Day 28. Secondary outcomes include oxygenation and lung compliance, intensive care unit (ICU) and hospital length of stay, use of rescue therapies for refractory hypoxaemia, rate of barotrauma, mortality (ICU, hospital and at 28, 90 and 180 days), quality of life and a health economic analysis at 6 months. DISCUSSION: The PHARLAP trial will determine whether the intervention strategy is effective in increasing ventilator-free days in patients with ARDS. If the PHARLAP strategy is proven to improve ventilator-free days, it will provide a strong impetus to conduct an international phase 3 trial to determine the effects of this strategy on mortality. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT01667146.
Subject(s)
Hypercapnia/etiology , Positive-Pressure Respiration , Respiratory Distress Syndrome/complications , Respiratory Distress Syndrome/therapy , Clinical Protocols , Humans , Hypercapnia/physiopathology , Prospective Studies , Research Design , Respiratory Distress Syndrome/physiopathology , Tidal VolumeABSTRACT
The gene expressing the FK506 binding protein 51 (FKBP5) is involved in the regulation of glucocorticoid receptor sensitivity. The rs1360780 SNP in this gene (T allele vs C homozygous) has been found to be associated with major depressive disorder (MDD). The aim of our study was to investigate whether this polymorphism might be associated with altered brain structure and function in a cohort of 40 patients with MDD and 43 healthy controls. A functional magnetic resonance imaging (fMRI) emotional attention task was employed. Diffusion tensor imaging (DTI) was also conducted, extracting mean diffusivity (MD) and fractional anisotropy (FA) from brain areas that showed functional differences between patients expressing the two alleles of the rs1360780 SNP. Finally, the effect of the interaction of childhood adversity as measured by the Childhood trauma Questionnaire (CTQ) and rs1360780 allele status was analyzed in relation to DTI measures using a general linear model. All results presented are family-wise error (FWE) corrected. Functional interactions were found between genotype and diagnosis (p<0.01). Patients carrying the high-risk allele, compared with patients not carrying it, showed reduced activity in the rolandic operculum, Heschl gyrus, insula, parahippocampal gyrus, posterior cingulate cortex, inferior frontal gyrus (p<0.05 for all measures); and increased MD and reduced FA measures in many of these regions (p<0.05). An interaction between CTQ scores and allele status was associated with DTI changes in the insula, rolandic operculum, and inferior frontal gyrus. Here, the presence of both the high-risk allele and higher CTQ scores was associated with higher MD and lower FA values (p<0.05). In conclusion, MDD patients expressing the T allele of rs1360780, compared with C homozygous patients, exhibit functional and structural differences in areas involved in emotional perception and inhibition. The interaction between the T allele and childhood maltreatment explained our structural findings in these regions, suggesting that their altered maturation and function might be influenced by early chronic stress in the presence of this genetic trait.
Subject(s)
Adult Survivors of Child Abuse , Brain/pathology , Brain/physiopathology , Depressive Disorder, Major/genetics , Emotions/physiology , Tacrolimus Binding Proteins/genetics , Adult , Attention/physiology , Brain Mapping , Cohort Studies , Depressive Disorder, Major/pathology , Depressive Disorder, Major/physiopathology , Diffusion Tensor Imaging , Female , Genetic Predisposition to Disease , Genotyping Techniques , Humans , Linear Models , Magnetic Resonance Imaging , Male , Middle Aged , Neuropsychological Tests , Polymorphism, Single NucleotideABSTRACT
BACKGROUND: The aim of the present study was to investigate the association of fMRI blood oxygen-level dependent (BOLD) reactivity with the level of epigenetic methylation of SLC6A4 in blood DNA from a sample of healthy participants and patients with major depressive disorder (MDD). METHODS: We investigated patients with MDD and healthy controls using fMRI and an emotional attention-shifting task. We assessed site-specific DNA methylation of a previously characterized SLC6A4 region in peripheral blood DNA using pyrosequencing. RESULTS: Our study involved 25 patients with MDD and 35 healthy controls. Activation in the anterior insula elicited by negative emotional content was significantly positively associated with the degree of SLC6A4 methylation. Significantly negative associations were observed between activation in the posterior insula and the degree of SLC6A4 methylation when judging the geometry of pictures after seeing negative in contrast to positive emotional stimuli. Healthy controls with a high degree of SLC6A4 methylation depicted significantly more activity elicited by positive stimuli in limbic regions and more activity elicited by negative stimuli in limbic as well as cognitive control regions than those with a low degree of SLC6A4 methylation. LIMITATIONS: It is impossible to measure methylation directly in the brain and thus we assessed peripheral methylation of SLC6A4. Since the association was cross-sectional, no conclusion about cause and effect can be drawn. CONCLUSION: Our study provides further support to the hypothesis that particular DNA methylation states that are associated with brain function during emotion processing are detectable in the periphery.
Subject(s)
Brain Chemistry/genetics , DNA Methylation , Depressive Disorder, Major/genetics , Emotions , Serotonin Plasma Membrane Transport Proteins/genetics , Adult , Cross-Sectional Studies , Depressive Disorder, Major/blood , Depressive Disorder, Major/epidemiology , Epigenesis, Genetic , Female , Humans , Linear Models , Magnetic Resonance Imaging , Male , Middle Aged , Promoter Regions, Genetic , Sequence Analysis, DNA , Serotonin Plasma Membrane Transport Proteins/blood , Young AdultABSTRACT
Serotonin plays an important role in the etiology of depression. Serotonin is also crucial for brain development. For instance, animal studies have demonstrated that early disruptions in the serotonin system affect brain development and emotion regulation in later life. A plausible explanation is that environmental stressors reprogram the serotonin system through epigenetic processes by altering serotonin system gene expression. This in turn may affect brain development, including the hippocampus, a region with dense serotonergic innervations and important in stress-regulation. The aim of this study was to test whether greater DNA methylation in specific CpG sites at the serotonin transporter promoter in peripheral cells is associated with childhood trauma, depression, and smaller hippocampal volume. We were particularly interested in those CpG sites whose state of methylation in peripheral cells had previously been associated with in vivo measures of brain serotonin synthesis. Thirty-three adults with Major Depressive Disorder (MDD) (23 females) and 36 matched healthy controls (21 females) were included in the study. Depressive symptoms, childhood trauma, and high-resolution structural MRI for hippocampal volume were assessed. Site-specific serotonin transporter methylation was assessed using pyrosequencing. Childhood trauma, being male, and smaller hippocampal volume were independently associated with greater peripheral serotonin transporter methylation. Greater serotonin transporter methylation in the depressed group was observed only in SSRI-treated patients. These results suggest that serotonin transporter methylation may be involved in physiological gene-environment interaction in the development of stress-related brain alterations. The results provide some indications that site-specific serotonin transporter methylation may be a biomarker for serotonin-associated stress-related psychopathology.
Subject(s)
DNA Methylation , Depressive Disorder, Major/genetics , Depressive Disorder, Major/pathology , Gene-Environment Interaction , Hippocampus/pathology , Serotonin Plasma Membrane Transport Proteins/genetics , Stress, Psychological , Adolescent , Adult , Aged , Brain/metabolism , Brain/pathology , Case-Control Studies , Epigenesis, Genetic , Female , Follow-Up Studies , Gene Expression Regulation , Genotype , Hippocampus/metabolism , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Polymorphism, Genetic/genetics , Prognosis , Promoter Regions, Genetic/genetics , Young AdultABSTRACT
Eukaryotic cells rapidly reduce protein synthesis in response to various stress conditions. This can be achieved by the phosphorylation-mediated inactivation of a key translation initiation factor, eukaryotic initiation factor 2 (eIF2). However, the persistent translation of certain mRNAs is required for deployment of an adequate stress response. We carried out ribosome profiling of cultured human cells under conditions of severe stress induced with sodium arsenite. Although this led to a 5.4-fold general translational repression, the protein coding open reading frames (ORFs) of certain individual mRNAs exhibited resistance to the inhibition. Nearly all resistant transcripts possess at least one efficiently translated upstream open reading frame (uORF) that represses translation of the main coding ORF under normal conditions. Site-specific mutagenesis of two identified stress resistant mRNAs (PPP1R15B and IFRD1) demonstrated that a single uORF is sufficient for eIF2-mediated translation control in both cases. Phylogenetic analysis suggests that at least two regulatory uORFs (namely, in SLC35A4 and MIEF1) encode functional protein products.
Subject(s)
Eukaryotic Initiation Factor-2/metabolism , Gene Expression Regulation/genetics , Open Reading Frames/genetics , Protein Biosynthesis/genetics , Repressor Proteins/metabolism , Arsenites/pharmacology , Gene Expression Regulation/drug effects , HEK293 Cells , Humans , Immediate-Early Proteins/genetics , Immediate-Early Proteins/metabolism , Mutagenesis, Site-Directed , Oxidative Stress/drug effects , Oxidative Stress/genetics , Protein Biosynthesis/drug effects , Protein Phosphatase 1/genetics , Protein Phosphatase 1/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Ribosomes/drug effects , Ribosomes/metabolism , Sodium Compounds/pharmacologyABSTRACT
The micro RNA 137 (miR-137) variant rs1625579 has been identified as a genome-wide significant risk variant for schizophrenia. miR-137 has an established role in neurodevelopment and may mediate cognitive dysfunction in schizophrenia. This role of miR-137 may be related to changes in brain morphology for risk-related genotypes; however this has not yet been delineated. Here we considered whether rs1625579 genotype was predictive of indices of brain structure in patients with schizophrenia and healthy controls. Structural magnetic resonance imaging (sMRI) data (i.e. 3T T1-TFE or 1.5T T1-MPRAGE) were acquired from 150 healthy controls and 163 schizophrenic patients. Two volumetric analyses that considered the impact of miR-137/rs1625579 genotype were carried out on sMRI data. In the first analysis, voxel based morphometry was employed to consider genotype-related variability in local grey and white matter across the entire brain volume. Our secondary analysis utilized the FIRST protocol in FSL to consider the volume of subcortical structures (i.e. bilateral accumbens, amygdala, caudate, hippocampus, pallidum, putamen and thalamus). Several brain regions in both analyses demonstrated the expected main effect of participant group (i.e. schizophrenics < controls), yet there were no regions where we observed an impact of rs1635579 genotype on brain volume. Our analyses suggest that the mechanism by which miR-137 confers risk for schizophrenia and impacts upon cognitive function may not be mediated by changes in local brain volume. However, it remains to be determined whether or not alternative measures of brain structure are related to these functions of miR-137.
Subject(s)
Brain/pathology , Genetic Predisposition to Disease , MicroRNAs/genetics , Polymorphism, Single Nucleotide/genetics , Schizophrenia/genetics , Adult , Case-Control Studies , Cerebral Cortex/pathology , Demography , Female , Humans , Male , Organ Size/geneticsABSTRACT
A single nucleotide polymorphism (SNP rs1625579) within the micro-RNA 137 (MIR137) gene recently achieved strong genome-wide association with schizophrenia (SZ). However, the mechanisms by which SZ risk may be mediated by this variant are unknown. As miRNAs have the potential to influence oligodendrocyte development, we investigated whether this SNP was associated with variability in white matter (WM) microstructure. Diffusion tensor imaging (DTI) was conducted on 123 healthy participants genotyped for rs1625579. The analysis consisted of whole-brain tract-based spatial statistics and atlas-based tractography analysis of six major WM tracts known to be affected in SZ - the inferior longitudinal fasciculus, the uncinate fasciculus, the inferior fronto-occipital fasciculus, the anterior thalamic radiation, the cingulum bundle and the corpus callosum. No significant differences in either whole-brain fractional anisotropy or mean diffusivity between MIR137 genotype groups were observed (p>0.05). Similarly, atlas-based tractography of particular tracts implicated in SZ failed to reveal any significant differences between MIR137 genotype groups on measures of WM connectivity (p>0.05). In the absence of WM effects comparable to those reported for other SZ associated genes, these data suggest that MIR137 alone may not confer variability in these WM measures and therefore may not act in isolation for any effects that the variant may have on WM microstructure in SZ samples.
Subject(s)
Genome, Human , MicroRNAs/genetics , Schizophrenia/genetics , White Matter/anatomy & histology , Adolescent , Adult , Aged , Diffusion Tensor Imaging , Female , Genetic Association Studies , Genotype , Humans , Male , Middle Aged , Polymorphism, Single Nucleotide , Schizophrenia/pathology , Young AdultABSTRACT
Identifying rare, highly penetrant risk mutations may be an important step in dissecting the molecular etiology of schizophrenia. We conducted a gene-based analysis of large (>100 kb), rare copy-number variants (CNVs) in the Wellcome Trust Case Control Consortium 2 (WTCCC2) schizophrenia sample of 1564 cases and 1748 controls all from Ireland, and further extended the analysis to include an additional 5196 UK controls. We found association with duplications at chr20p12.2 (P = 0.007) and evidence of replication in large independent European schizophrenia (P = 0.052) and UK bipolar disorder case-control cohorts (P = 0.047). A combined analysis of Irish/UK subjects including additional psychosis cases (schizophrenia and bipolar disorder) identified 22 carriers in 11 707 cases and 10 carriers in 21 204 controls [meta-analysis Cochran-Mantel-Haenszel P-value = 2 × 10(-4); odds ratio (OR) = 11.3, 95% CI = 3.7, ∞]. Nineteen of the 22 cases and 8 of the 10 controls carried duplications starting at 9.68 Mb with similar breakpoints across samples. By haplotype analysis and sequencing, we identified a tandem ~149 kb duplication overlapping the gene p21 Protein-Activated Kinase 7 (PAK7, also called PAK5) which was in linkage disequilibrium with local haplotypes (P = 2.5 × 10(-21)), indicative of a single ancestral duplication event. We confirmed the breakpoints in 8/8 carriers tested and found co-segregation of the duplication with illness in two additional family members of one of the affected probands. We demonstrate that PAK7 is developmentally co-expressed with another known psychosis risk gene (DISC1) suggesting a potential molecular mechanism involving aberrant synapse development and plasticity.
Subject(s)
Bipolar Disorder/genetics , Chromosome Duplication , Nerve Tissue Proteins/metabolism , Psychotic Disorders/genetics , Schizophrenia/genetics , p21-Activated Kinases/genetics , p21-Activated Kinases/metabolism , Bipolar Disorder/pathology , Case-Control Studies , Chromosome Breakpoints , DNA Copy Number Variations , Female , Genetic Predisposition to Disease , Genome-Wide Association Study , Humans , Linkage Disequilibrium , Male , Neuronal Plasticity , Psychotic Disorders/pathology , Schizophrenia/pathology , White People/geneticsABSTRACT
The hexonucleotide repeat expansion 'GGGGCC' at the C9ORF72 gene has been strongly linked with amyotrophic lateral sclerosis and frontotemporal dementia. There is some evidence for clinical and genetic overlap between frontotemporal dementia and schizophrenia. Here, we genotyped the repeat at C9ORF72 in a large Irish psychosis case-control sample (n = 2477). We found no carriers of >30 repeats. We found 7 samples with >22 repeats, 2 schizophrenia cases and 5 controls, but overall we observed no difference in the distribution of the repeat between our case and control samples. By using genome-wide association data to phase haplotypes at this gene, we investigated if carriers of the repeat expansion arose from a single common founder. All samples that carry 17 or more repeats also carry the founder haplotype and overall there is a very strong correlation between repeat length and the founder haplotype (Spearman rho = 0.714, p < 0.001). Our study provides further evidence to bolster the claim that carriers of the repeat expansion at C9ORF72 arose from a single common founder.
Subject(s)
DNA Repeat Expansion/genetics , Haplotypes/genetics , Proteins/genetics , Psychotic Disorders/genetics , C9orf72 Protein , Case-Control Studies , Genome-Wide Association Study , Heterozygote , Humans , Ireland/epidemiology , Psychotic Disorders/epidemiologyABSTRACT
BACKGROUND: MIR137 is implicated in brain development and encodes a microRNA that regulates neuronal maturation and adult neurogenesis. Recently, a common genetic variant within MIR137 showed genome wide evidence of association with schizophrenia, and with altered amygdala activation in those at genetic risk for schizophrenia. Following this evidence, we investigated the effects of MIR137 genotype on neuronal activity during face processing. METHODS: By grouping 81 healthy participants as carrier or non-carriers of the MIR137 rs1625579 risk allele associated with schizophrenia, we investigated MIR137's effects on altered cortical response during an fMRI face processing task and altered functional connectivity using the amygdala as a seed region. RESULTS: Homozygous carriers of the risk allele were observed to show relatively increased functional connectivity between the right amygdala and frontal regions that play a key role in emotion processing and regulation (e.g. the cingulate and prefrontal cortex). CONCLUSIONS: Our findings provide the first evidence that the rs1625579 variant affects fronto-amygdala functional connectivity, providing further evidence that MIR137 may contribute to forms of psychosis in which affective symptoms are more prominent.
Subject(s)
Amygdala/physiopathology , Brain Mapping , Frontal Lobe/physiopathology , MicroRNAs/genetics , Neural Pathways/physiopathology , Visual Perception/genetics , Adolescent , Adult , Aged , Alleles , Emotions/physiology , Female , Genotype , Humans , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Male , Middle Aged , Polymorphism, Single Nucleotide , Schizophrenia/genetics , Young AdultABSTRACT
BACKGROUND: A single nucleotide polymorphism (rs7914558) within the cyclin M2 (CNNM2) gene was recently identified as a common risk variant for schizophrenia. The mechanism by which CNNM2 confers risk is unknown. AIMS: To determine the impact of the rs7914558 risk 'G' allele [corrected] on measures of neurocognition, social cognition and brain structure. METHOD: Patients with schizophrenia (n = 400) and healthy controls (n = 160) completed measures of neuropsychological function and social cognition. Structural magnetic resonance imaging data were also acquired from an overlapping sample of Irish healthy controls (n = 159) and an independent sample of Italian patients (n = 82) and healthy controls (n = 39). RESULTS: No effects of genotype on neuropsychological test performance were observed. However, a dosage effect of the risk allele was found for an index of social cognition (i.e. attributional style), such that risk status was associated with reduced self-serving bias across groups (GG>AG>AA, P<0.05). Using voxel-based morphometry to investigate neuroanatomical regions putatively supporting social cognition, risk carriers had relatively increased grey matter volume in the right temporal pole and right anterior cingulate cortex (Pcorrected<0.05) in the Irish healthy controls sample; neuroanatomical associations between CNNM2 and grey matter volume in anterior cingulate cortex were also observed in the Italian schizophrenia and healthy controls samples. CONCLUSIONS: Although the biological role of CNNM2 in schizophrenia remains unknown, these data suggest that this CNNM2 risk variant rs7914558 may have an impact on neural systems relevant to social cognition. How such effects may mediate the relationship between genotype and disease risk remains to be established.
Subject(s)
Brain/pathology , Cyclins/physiology , Internal-External Control , Schizophrenia/genetics , Schizophrenic Psychology , Adolescent , Adult , Aged , Alleles , Analysis of Variance , Case-Control Studies , Cation Transport Proteins , Cyclins/genetics , Emotional Intelligence/genetics , Genetic Predisposition to Disease , Genome-Wide Association Study , Gyrus Cinguli/pathology , Humans , Ireland , Italy , Linkage Disequilibrium , Magnetic Resonance Imaging/methods , Middle Aged , Neuropsychological Tests/statistics & numerical data , Organ Size , Polymorphism, Single Nucleotide/physiology , Schizophrenia/pathology , Temporal Lobe/pathology , Young AdultABSTRACT
The single nucleotide polymorphism rs10503253 within the CUB and Sushi multiple domains-1 (CSMD1) gene on 8p23.2 has been identified as genome-wide significant for schizophrenia (SZ). This gene is of unknown function but has been implicated in multiple neurodevelopmental disorders that impact upon cognition, leading us to hypothesize that an effect on brain structure and function underlying cognitive processes may be part of the mechanism by which CMSD1 increases illness risk. To test this hypothesis, we investigated this CSMD1 variant in vivo in healthy participants in a magnetic resonance imaging (MRI) study comprised of both fMRI of spatial working memory (N = 50) and a voxel-based morphometry investigation of grey and white matter (WM) volume (N = 150). Analyses of these data indicated that the risk "A" allele was associated with comparatively reduced cortical activations in BA18, that is, middle occipital gyrus and cuneus; posterior brain regions that support maintenance processes during performance of a spatial working memory task. Conversely, there was an absence of significant structural differences in brain volume (i.e., grey or WM). In accordance with previous evidence, these data suggest that CSMD1 may mediate brain function related to cognitive processes (i.e., executive function); with the relatively deleterious effects of the identified "A" risk allele on brain activity possibly constituting part of the mechanism by which CSMD1 increases schizophrenia risk.
Subject(s)
Cognition Disorders/etiology , Genome-Wide Association Study , Membrane Proteins/genetics , Polymorphism, Single Nucleotide/genetics , Schizophrenia/genetics , Adult , Brain Mapping , Case-Control Studies , Female , Genetic Predisposition to Disease , Humans , Magnetic Resonance Imaging , Male , Neuropsychological Tests , Prognosis , Risk Factors , Schizophrenia/complications , Tumor Suppressor Proteins , Young AdultABSTRACT
A single Mendelian trait has been mapped to the human Y chromosome: Y-linked hearing impairment. The molecular basis of this disorder is unknown. Here, we report the detailed characterization of the DFNY1 Y chromosome and its comparison with a closely related Y chromosome from an unaffected branch of the family. The DFNY1 chromosome carries a complex rearrangement, including duplication of several noncontiguous segments of the Y chromosome and insertion of â¼160 kb of DNA from chromosome 1, in the pericentric region of Yp. This segment of chromosome 1 is derived entirely from within a known hearing impairment locus, DFNA49. We suggest that a third copy of one or more genes from the shared segment of chromosome 1 might be responsible for the hearing-loss phenotype.
Subject(s)
Chromosomes, Human, Y/genetics , Genes, Y-Linked/genetics , Hearing Loss/genetics , Female , Gene Rearrangement/genetics , Humans , Male , PedigreeABSTRACT
The interaction between adverse life events during childhood and genetic factors is associated with a higher risk to develop major depressive disorder (MDD). One of the polymorphisms found to be associated with MDD is the Val66MET polymorphism of brain-derived neurotrophic factor (BDNF). The aim of our two-center study was to determine how the BDNF Val66Met polymorphism and childhood adversity affect the volumetric measures of the hippocampus in healthy individuals and people with MDD. In this two-center study, 62 adult patients with MDD and 71 healthy matched controls underwent high-resolution magnetic resonance imaging. We used manual tracing of the bilateral hippocampal structure with help of the software BRAINS2, assessed childhood adversity using the Childhood Trauma Questionnaire and genotyped Val66Met BDNF SNP (rs6265). MDD patients had smaller hippocampal volumes, both in the left and right hemispheres (F = 5.4, P = 0.022). We also found a significant interaction between BDNF allele and history of childhood adversity (F = 6.1, P = 0.015): Met allele carriers in our samples showed significantly smaller hippocampal volumes when they did have a history of childhood adversity, both in patients and controls. Our results highlight how relevant stress-gene interactions are for hippocampal volume reductions. Subjects exposed to early life adversity developed smaller hippocampal volumes when they carry the Met-allele of the BDNF polymorphism.
Subject(s)
Amino Acid Substitution/genetics , Brain-Derived Neurotrophic Factor/genetics , Hippocampus/pathology , Polymorphism, Single Nucleotide/genetics , Stress, Psychological/genetics , Adult , Alleles , Case-Control Studies , Demography , Female , Humans , Male , Middle Aged , Organ SizeABSTRACT
Genes and early-life adversity (ELA) interactively increase the risk of developing major depressive disorder (MDD). A recent genome-wide association study suggests that the minor T-allele of single-nucleotide polymorphisms in the bicaudal C homolog 1 gene (BICC1) has a protective role against MDD. The aims of the study were to investigate whether the minor T-allele of BICC1 is protective against hippocampal structural brain changes, whether it is associated with increased functional brain activity in the emotion regulation system, and how ELA would modify this association. Forty-four patients with MDD and 44 healthy controls were investigated using structural magnetic resonance imaging (MRI) and functional MRI with an emotion inhibition task. Analysis of a single-nucleotide polymorphism in the BICC1-1 (rs999845) gene was performed. Right hippocampal bodies of patients and controls without a history of ELA and who carry the protective T-allele of BICC1 were significantly larger compared with those participants homozygous for the major C-allele of BICC1. However, MDD patients with ELA, who carry the T-allele, had smaller hippocampal head volumes compared with MDD patients without ELA. FMRI showed that patients and controls carrying the protective T-allele of BICC1 activate the emotion regulation system significantly more compared with those participants homozygous for the major C-allele (p<0.05, family wise error corrected). These results are suggestive that the minor T-allele of BICC1 has a protective role against MDD and its known structural and functional brain changes. However, this protective effect seems to be lost in the case of co-occurrence of ELA.
Subject(s)
Brain/pathology , Brain/physiology , Depressive Disorder, Major/genetics , Depressive Disorder, Major/pathology , Genetic Variation/genetics , RNA-Binding Proteins/genetics , Adult , Female , Humans , Magnetic Resonance Imaging/methods , Male , Middle Aged , Psychomotor Performance/physiology , Young AdultABSTRACT
A single nucleotide polymorphism rs12807809 located upstream of the neurogranin (NRGN) gene has been identified as a risk variant for schizophrenia in recent genome-wide association studies. To date, there has been little investigation of the endophenotypic consequences of this variant, and our own investigations have suggested that the effects of this gene are not apparent at the level of cognitive function in patients or controls. Because the impact of risk variants may be more apparent at the level of brain, the aim of this investigation was to delineate whether NRGN genotype predicted variability in brain structure and/or function. Healthy individuals participated in structural (N = 140) and/or functional (N = 36) magnetic resonance imaging (s/fMRI). Voxel-based morphometry was used to compare gray and white matter volumes between carriers of the non-risk C allele (i.e., CC/CT) and those who were homozygous for the risk T allele. Functional imaging data were acquired during the performance of a spatial working memory task, and were also analyzed with respect to the difference between C carriers and T homozygotes. There was no effect of the NRGN variant rs12807809 on behavioral performance or brain structure. However, there was a main effect of genotype on brain activity during performance of the working memory task, such that while C carriers exhibited a load-independent decrease in left superior frontal gyrus/BA10, TT individuals failed to show a similar decrease in activity. The failure to disengage this ventromedial prefrontal region, despite preserved performance, may be indicative of a reduction in processing efficiency in healthy TT carriers. Although it remains to be established whether this holds true in larger samples and in patient cohorts, if valid, this suggests a potential mechanism by which NRGN variability might contribute to schizophrenia risk.
Subject(s)
Brain/pathology , Brain/physiopathology , Genetic Predisposition to Disease , Neurogranin/genetics , Polymorphism, Single Nucleotide , Schizophrenia/genetics , Adult , Alleles , Female , Genotype , Humans , Magnetic Resonance Imaging , Male , Memory, Short-Term , Schizophrenia/pathology , Schizophrenia/physiopathology , Young AdultABSTRACT
BACKGROUND: Polymorphisms in the brain-derived neurotrophic factor (BDNF) gene and its receptor neurotrophic tyrosine kinase receptor type 2 (NTRK2) have been implicated in mood disorders. The aim of this study was to examine whether the NTRK2 and BDNF polymorphisms impact brain white matter connections in major depressive disorder and whether they may also have an interactive effect with environmental stress in the form of early life adversity. METHODS: The study group comprised 45 depressed patients and 45 age- and gender-matched control subjects. High angular resolution diffusion images were obtained and analyzed using tract-based spatial statistics. Analysis of a single nucleotide polymorphism in the BDNF (rs6265/Valine66Methionine) and NTRK2 (rs11140714) genes was performed. RESULTS: An interactive effect was found between NTRK2 and depression diagnosis maximally affecting the cingulum. Depressed patients homozygous for the A allele of NTRK2 showed significantly reduced fractional anisotropy compared with depressed patients with at least one copy of the G allele or control subjects with either the A/A or G carrier genotypes in the left and right corona radiata, left uncinate fasciculus, left inferior fronto-occipital fasciculus, left cerebral peduncle, posterior thalamic radiation, and middle cerebral peduncle. Significantly smaller gray matter volume was seen in frontal lobe regions in patients homozygous for the A allele. CONCLUSIONS: Polymorphisms in NTRK2 gene increase risk of architectural changes in several brain regions involved in emotional regulation.
Subject(s)
Brain/pathology , Depressive Disorder, Major/genetics , Depressive Disorder, Major/pathology , Nerve Fibers, Myelinated/pathology , Polymorphism, Single Nucleotide/genetics , Receptor, trkB/genetics , Adult , Analysis of Variance , Anisotropy , Brain-Derived Neurotrophic Factor/genetics , Diffusion Tensor Imaging , Female , Genotype , Humans , Image Processing, Computer-Assisted , Male , Middle Aged , Psychiatric Status Rating Scales , Young AdultABSTRACT
A common polymorphism within the nitric oxide sythanse-1 (NOS1) gene (rs6490121), initially identified as risk variant for schizophrenia, has been associated with variation in working memory and IQ. Here we investigated how this variation might be mediated at the level of brain structure and function. In healthy individuals (N=157), voxel based morphometry was used to compare grey matter (GM) volume between homozygous and heterozygous carriers of the 'G' allele (i.e. the allele associated with impaired cognition and schizophrenia risk) and homozygous carriers of the non-risk 'A' allele. Functional brain imaging data were also acquired from 48 participants during performance of a spatial working memory (SWM) task, and analysed to determine any effect of NOS1 risk status. An a priori region-of-interest analysis identified a significant reduction in ventromedial prefrontal GM volume in 'G' allele carriers. Risk carriers also exhibited altered patterns of activation in the prefrontal cortex, caudate, and superior parietal lobe, which were characteristic of abnormal increases in activation in frontoparietal working memory networks and a failure to disengage regions of the default mode network. These functional changes suggest a NOS1-mediated processing inefficiency, which may contribute to cognitive dysfunction in schizophrenia. While the mechanisms by which NOS1 may influence brain structure and/or function have not yet been well delineated, these data provide further evidence for a role of NOS1 in risk for schizophrenia via an impact upon cognitive function.