213 research outputs found
Diez herramientas digitales para facilitar la evaluación formativa
This article suggests 10 digital tools that encourage teachers to exploit their creativity to design formative assessment activities. For an assessment to fulfill a formative function it must provide the students with information that empower them to make decisions and adjustments in their learning process. Technology enables embedding evaluation during instruction and simplifies feedback, automatizing activities that otherwise are time-consuming for teachers. The selected tools allow the development of a great variety of assignments that promote self-evaluation, cooperation and feedback. The review recommends free or low-cost technology, that support learning management system integration and adaptable to all learning levels.Este artículo sugiere 10 herramientas digitales que permiten al profesor explotar su creatividad en el diseño de actividades de evaluación formativa y compartida. Para que una evaluación cumpla su función formativa debe proveer al alumno información que le permita tomar decisiones para realizar ajustes en su proceso de aprendizaje. La tecnología habilita la integración de la evaluación al proceso de enseñanza facilitando la retroalimentación, automatizando actividades que de otra manera consumen mucho tiempo del docente. Las herramientas seleccionadas permiten generar una gran variedad de tareas que favorecen la autoevaluación, la cooperación y la retroalimentación. Se recomiendan tecnologías gratuitas o de bajo costo, con posibilidad de integración a plataformas digitales didácticas, adaptables en todos los niveles educativos
Methionine sulfoxide reductase regulates brain catechol-O-methyl transferase activity
This is the published version. Copyright 2014 Oxford University PressCatechol-O-methyl transferase (COMT) plays a key role in the degradation of brain dopamine (DA). Specifically,
low COMT activity results in higher DA levels in the prefrontal cortex (PFC), thereby reducing the vulnerability
for attentional and cognitive deficits in both psychotic and healthy individuals. COMT activity is markedly
reduced by a non-synonymous single-nucleotide polymorphism (SNP) that generates a valine-to-methionine
substitution on the residue 108/158, by means of as-yet incompletely understood post-translational mechanisms.
One post-translational modification is methionine sulfoxide, which can be reduced by the methionine sulfoxide
reductase (Msr) A and B enzymes. We used recombinant COMT proteins (Val/Met108) and mice (wild-type (WT)
and MsrA knockout) to determine the effect of methionine oxidation on COMT activity and COMT interaction
with Msr, through a combination of enzymatic activity and Western blot assays. Recombinant COMT activity is
positively regulated by MsrA, especially under oxidative conditions, whereas brains of MsrA knockout mice
exhibited lower COMT activity (as compared with their WT counterparts). These results suggest that COMT activity
may be reduced by methionine oxidation, and point to Msr as a key molecular determinant for the modulation
of COMT activity in the brain. The role of Msr in modulating cognitive functions in healthy individuals
and schizophrenia patients is yet to be determined
The enzymatic activities of brain COMT and methionine sulfoxide reductase are correlated in a COMT Val/Met allele-dependent fashion
This is the peer reviewed version of the following article: J. Moskovitz, C. Walss-Bass, D. A. Cruz, P. M. Thompson, J. Hairston and M. Bortolato (2015) Neuropathology and Applied Neurobiology The enzymatic activities of brain catechol-O-methyltransferase (COMT) and methionine sulphoxide reductase are correlated in a COMT Val/Met allele-dependent fashion, which has been published in final form at http://doi.org/10.1111/nan.12219. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.AIMS: The enzyme catechol-O-methyl transferase (COMT) plays a primary role in the metabolism of catecholamine neurotransmitters and is implicated in the modulation of cognitive and emotional responses. The best-characterized single nucleotide polymorphism (SNP) of the COMT gene consists of a valine (Val)-to-methionine (Met) substitution at codon 108/158. The Met-containing variant confers a marked reduction in COMT catalytic activity. We recently showed that the activity of recombinant COMT is positively regulated by the enzyme Met sulfoxide reductase (MSR), which counters the oxidation of Met residues of proteins. The current study was designed to assess whether brain COMT activity may be correlated to MSR in an allele-dependent fashion. METHODS: COMT and MSR activities were measured from post-mortem samples of prefrontal cortices, striata and cerebella of 32 subjects, by using catechol and dabsyl-Met sulfoxide as substrates, respectively. Allelic discrimination of COMT Val108/185Met SNP was performed using the Taqman 5’nuclease assay. RESULTS: Our studies revealed that, in homozygous carriers of Met, but not Val alleles, the activity of COMT and MSR were significantly correlated throughout all tested brain regions. DISCUSSION: These results suggest that the reduced enzymatic activity of Met-containing COMT may be secondary to Met sulfoxidation, and point to MSR as a key molecular determinant for the modulation of COMT activity
Genetics and Epigenetics of Self-Injurious Thoughts and Behaviors: Systematic Review of the Suicide Literature and Methodological Considerations
Suicide is a multifaceted and poorly understood clinical outcome, and there is an urgent need to advance research on its phenomenology and etiology. Epidemiological studies have demonstrated that suicidal behavior is heritable, suggesting that genetic and epigenetic information may serve as biomarkers for suicide risk. Here we systematically review the literature on genetic and epigenetic alterations observed in phenotypes across the full range of self-injurious thoughts and behaviors (SITB). We included 577 studies focused on genome-wide and epigenome-wide associations, candidate genes (SNP and methylation), noncoding RNAs, and histones. Convergence of specific genes is limited across units of analysis, although pathway-based analyses do indicate nervous system development and function and immunity/inflammation as potential underlying mechanisms of SITB. We provide suggestions for future work on the genetic and epigenetic correlates of SITB with a specific focus on measurement issues
The NRG1 exon 11 missense variant is not associated with autism in the Central Valley of Costa Rica
<p>Abstract</p> <p>Background</p> <p>We are conducting a genetic study of autism in the isolated population of the Central Valley of Costa Rica (CVCR). A novel Neuregulin 1 (NRG1) missense variant (exon 11 G>T) was recently associated with psychosis and schizophrenia (SCZ) in the same population isolate.</p> <p>Methods</p> <p>We genotyped the NRG1 exon 11 missense variant in 146 cases with autism, or autism spectrum disorder, with CVCR ancestry, and both parents when available (N = 267 parents) from 143 independent families. Additional microsatellites were genotyped to examine haplotypes bearing the exon 11 variant.</p> <p>Results</p> <p>The NRG1 exon 11 G>T variant was found in 4/146 cases including one de novo occurrence. The frequency of the variant in case chromosomes was 0.014 and 0.045 in the parental non-transmitted chromosomes. At least 6 haplotypes extending 0.229 Mb were associated with the T allele. Three independent individuals, with no personal or family history of psychiatric disorder, shared at least a 1 megabase haplotype 5' to the T allele.</p> <p>Conclusion</p> <p>The NRG1 exon 11 missense variant is not associated with autism in the CVCR.</p
Within Subject Cross-Tissue Analyzes of Epigenetic Clocks in Substance Use Disorder Postmortem Brain and Blood.
There is a possible accelerated biological aging in patients with substance use disorders (SUD). The evaluation of epigenetic clocks, which are accurate estimators of biological aging based on DNA methylation changes, has been limited to blood tissue in patients with SUD. Consequently, the impact of biological aging in the brain of individuals with SUD remains unknown. In this study, we evaluated multiple epigenetic clocks (DNAmAge, DNAmAgeHannum, DNAmAgeSkinBlood, DNAmPhenoAge, DNAmGrimAge, and DNAmTL) in individuals with SUD (n=42), including alcohol (n=10), opioid (n=19), and stimulant use disorder (n=13), and controls (n=10) in postmortem brain (prefrontal cortex) and blood tissue obtained from the same individuals. We found a higher DNAmPhenoAge (beta=0.191, p-value=0.0104) and a nominally lower DNAmTL (beta=−0.149, p-value=0.0603) in blood from individuals with SUD compared to controls. SUD subgroup analysis showed a nominally lower brain DNAmTL in subjects with alcohol use disorder, compared to stimulant use disorder and controls (beta=0.0150, p-value=0.087). Cross-tissue analyses indicated a lower blood DNAmTL and a higher blood DNAmAge compared to their respective brain values in the SUD group. This study highlights the relevance of tissue specificity in biological aging studies and suggests that peripheral measures of epigenetic clocks in SUD may depend on the specific type of drug used
Within Subject Cross-Tissue Analyzes of Epigenetic Clocks in Substance Use Disorder Postmortem Brain and Blood
There is a possible accelerated biological aging in patients with substance use disorders (SUD). The evaluation of epigenetic clocks, which are accurate estimators of biological aging based on DNA methylation changes, has been limited to blood tissue in patients with SUD. Consequently, the impact of biological aging in the brain of individuals with SUD remains unknown. In this study, we evaluated multiple epigenetic clocks (DNAmAge, DNAmAgeHannum, DNAmAgeSkinBlood, DNAmPhenoAge, DNAmGrimAge, and DNAmTL) in individuals with SUD (n = 42), including alcohol (n = 10), opioid (n = 19), and stimulant use disorder (n = 13), and controls (n = 10) in postmortem brain (prefrontal cortex) and blood tissue obtained from the same individuals. We found a higher DNAmPhenoAge (β = 0.191, p-value = 0.0104) and a nominally lower DNAmTL (β = -0.149, p-value = 0.0603) in blood from individuals with SUD compared to controls. SUD subgroup analysis showed a nominally lower brain DNAmTL in subjects with alcohol use disorder, compared to stimulant use disorder and controls (β = 0.0150, p-value = 0.087). Cross-tissue analyzes indicated a lower blood DNAmTL and a higher blood DNAmAge compared to their respective brain values in the SUD group. This study highlights the relevance of tissue specificity in biological aging studies and suggests that peripheral measures of epigenetic clocks in SUD may depend on the specific type of drug used
Epigenetic Grimage Acceleration and Cognitive Impairment in Bipolar Disorder
Bipolar disorder (BD) has been previously associated with clinical signs of premature aging, including accelerated epigenetic aging in blood and brain, and a steeper age-related decline in cognitive function. However, the clinical drivers and cognitive correlates of epigenetic aging in BD are still unknown. We aimed to investigate the relationship between multiple measures of epigenetic aging acceleration with clinical, functioning, and cognitive outcomes in patients with BD and controls. Blood genome-wide DNA methylation levels were measured in BD patients (n = 153) and matched healthy controls (n = 50) with the Infinium MethylationEPIC BeadChip (Illumina). Epigenetic age estimates were calculated using an online tool, including the recently developed lifespan predictor GrimAge, and analyzed with generalized linear models controlling for demographic variables and blood cell proportions. BD was significantly associated with greater GrimAge acceleration (AgeAccelGrim, β=0.197, p = 0.009), and significant group-dependent interactions were found between AgeAccelGrim and blood cell proportions (CD4+ T-lymphocytes, monocytes, granulocytes, and B-cells). Within patients, higher AgeAccelGrim was associated with worse cognitive function in multiple domains (short-term affective memory (β=-0.078, p = 0.030), short-term non-affective memory (β=-0.088, p = 0.018), inhibition (β=0.064, p = 0.046), and problem solving (β=-0.067, p = 0.034)), age of first diagnosis with any mood disorder (β=-0.076, p = 0.039) or BD (β=-0.102, p = 0.016), as well as with current non-smoking status (β=-0.392, p \u3c 0.001). Overall, our findings support the contribution of epigenetic factors to the aging-related cognitive decline and premature mortality reported in BD patients, with an important driving effect of smoking in this population
Prenatal Cocaine Exposure and Its Influence on Pediatric Epigenetic Clocks and Epigenetic Scores in Humans
The investigation of the effects of prenatal cocaine exposure (PCE) on offspring has been inconsistent, with few studies investigating biological outcomes in humans. We profiled genome-wide DNA methylation (DNAm) of umbilical cord blood (UCB) from newborns with (n = 35) and without (n = 47) PCE. We used DNAm data to (1) assess pediatric epigenetic clocks at birth and (2) to estimate epigenetic scores (ES) for lifetime disorders. We generated gestational epigenetic age estimates (DNAmGA) based on Knight and Bohlin epigenetic clocks. We also investigated the association between DNAmGA and UCB serum brain-derived neurotrophic factor (BDNF) levels. Considering the large-scale DNAm data availability and existing evidence regarding PCE as a risk for health problems later in life, we generated ES for tobacco smoking, psychosis, autism, diabetes, and obesity. A gene ontology (GO) analysis on the CpGs included in the ES with group differences was performed. PCE was associated with lower DNAmGA in newborns, and this effect remained significant when controlling for potential confounders, such as blood cell type composition predicted by DNAm and obstetric data. DNAmGA was negatively correlated with BDNF levels in the serum of UCB. Higher tobacco smoking, psychosis, and diabetes ES were found in the PCE group. The GO analysis revealed GABAergic synapses as a potential pathway altered by PCE. Our findings of decelerated DNAmGA and ES for adverse phenotypes associated with PCE, suggest that the effects of gestational cocaine exposure on the epigenetic landscape of human newborns are detectable at birth
A Human Stem Cell-Derived Neuronal Model of Morphine Exposure Reflects Brain Dysregulation in Opioid Use Disorder: Transcriptomic and Epigenetic Characterization of Postmortem-Derived iPSC Neurons
INTRODUCTION: Human-derived induced pluripotent stem cell (iPSC) models of brain promise to advance our understanding of neurotoxic consequences of drug use. However, how well these models recapitulate the actual genomic landscape and cell function, as well as the drug-induced alterations, remains to be established. New
METHODS: We engineered a novel induced pluripotent stem cell-derived model of neural progenitor cells and neurons from cultured postmortem human skin fibroblasts, and directly compared these to isogenic brain tissue from the donor source. We assessed the maturity of the cell models across differentiation from stem cells to neurons using RNA cell type and maturity deconvolution analyses as well as DNA methylation epigenetic clocks trained on adult and fetal human tissue. As proof-of-concept of this model\u27s utility for substance use disorder studies, we compared morphine- and cocaine-treated neurons to gene expression signatures in postmortem Opioid Use Disorder (OUD) and Cocaine Use Disorder (CUD) brains, respectively.
RESULTS: Within each human subject (N = 2, 2 clones each), brain frontal cortex epigenetic age parallels that of skin fibroblasts and closely approximates the donor\u27s chronological age; stem cell induction from fibroblast cells effectively sets the epigenetic clock to an embryonic age; and differentiation of stem cells to neural progenitor cells and then to neurons progressively matures the cells
DISCUSSION: In summary, we introduce an iPSC model generated from human postmortem fibroblasts that can be directly compared to corresponding isogenic brain tissue and can be used to model perturbagen exposure such as that seen in opioid use disorder. Future studies with this and other postmortem-derived brain cellular models, including cerebral organoids, can be an invaluable tool for understanding mechanisms of drug-induced brain alterations
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