The role of BDNF methylation and Val66 Met in amygdala reactivity during emotion processing

Zhi-zi-chi decoction mitigates depression by enhancing lncRNA Six3os1 expression and promoting histone H3K4 methylation at the BDNF promoter

Traditional Chinese medicine, particularly Zhi-zi-chi decoction (ZZCD), is gaining recognition as a potential treatment for depression. This study aimed to uncover the molecular mechanisms behind ZZCD's antidepressant effects, focusing on lncRNA Six3os1 and histone H3K4 methylation at the BDNF promoter. Network pharmacology and in vivo experiments were conducted to identify ZZCD targets and evaluate its impact on depression-related behaviours and neuron injury. The role of Six3os1 in recruiting KMT2A to the BDNF promoter and its effects on oxidative stress and neuron injury were investigated. ZZCD reduced depression-like behaviours and neuron injury in mice subjected to chronic stress. It upregulated Six3os1, which facilitated KMT2A recruitment to the BDNF promoter, leading to increased histone H3K4 methylation and enhanced BDNF expression. ZZCD also inhibited CORT-induced neuron injury, inflammatory response and oxidative stress in vitro. ZZCD's antidepressant properties involve Six3os1 upregulation, which exerts neuroprotective effects by inhibiting oxidative stress and neuron injury, thereby alleviating depressive symptoms. Targeting Six3os1 upregulation may offer a potential therapeutic intervention for depression.

The stress-vulnerability model on the path to schizophrenia: Interaction between BDNF methylation and schizotypy on the resting-state brain network

The interplay between schizophrenia liability and environmental influences has been considered to be responsible for the development of schizophrenia. Recent neuroimaging studies have linked aberrant functional connectivity (FC) between the default-mode network (DMN) and the frontoparietal network (FPN) in the resting-state to the underlying neural mechanism of schizophrenia. By using schizotypy as the proxy for genetic-based liability to schizophrenia and methylation of brain-derived neurotrophic factor (BDNF) to represent environmental exposure, this study investigated the impact of the interaction between vulnerability and the environment on the neurobiological substrates of schizophrenia. Participants in this study included 101 healthy adults (HC) and 46 individuals with ultra-high risk for psychosis (UHR). All participants were tested at resting-state by functional magnetic resonance imaging, and group-independent component analysis was used to identify the DMN and the FPN. The Perceptual Aberration Scale (PAS) was used to evaluate the schizotypy level. The methylation status of BDNF was measured by pyrosequencing. For moderation analysis, the final sample consisted of 83 HC and 32 UHR individuals. UHR individuals showed reduced DMN-FPN network FC compared to healthy controls. PAS scores significantly moderated the relationship between the percentage of BDNF methylation and DMN-FPN network FC. The strength of the positive relationship between BDNF methylation and the network FC was reduced when the schizotypy level increased. These findings support the moderating role of schizotypy on the neurobiological mechanism of schizophrenia in conjunction with epigenetic changes.

DNA methylation patterns and gene expression from amygdala tissue of mature Brahman cows exposed to prenatal stress

Prenatal stress can alter postnatal performance and temperament of cattle. These phenotypic effects may result from changes in gene expression caused by stress-induced epigenetic alterations. Specifically, shifts in gene expression caused by DNA methylation within the brain’s amygdala can result in altered behavior because it regulates fear, stress response and aggression in mammals Thus, the objective of this experiment was to identify DNA methylation and gene expression differences in the amygdala tissue of 5-year-old prenatally stressed (PNS) Brahman cows compared to control cows. Pregnant Brahman cows (n = 48) were transported for 2-h periods at 60 ± 5, 80 ± 5, 100 ± 5, 120 ± 5, and 140 ± 5 days of gestation. A non-transported group (n = 48) were controls (Control). Amygdala tissue was harvested from 6 PNS and 8 Control cows at 5 years of age. Overall methylation of gene body regions, promoter regions, and cytosine-phosphate-guanine (CpG) islands were compared between the two groups. In total, 202 genes, 134 promoter regions, and 133 CpG islands exhibited differential methylation (FDR ≤ 0.15). Following comparison of gene expression in the amygdala between the PNS and Control cows, 2 differentially expressed genes were identified (FDR ≤ 0.15). The minimal differences observed could be the result of natural changes of DNA methylation and gene expression as an animal ages, or because this degree of transportation stress was not severe enough to cause lasting effects on the offspring. A younger age may be a more appropriate time to assess methylation and gene expression differences produced by prenatal stress.

Emotional Intelligence in Carriers of Different СОМТ, BDNF, DRD2 and HTR2A Genotypes

Background

Emotional intelligence is the ability to quickly and correctly recognize the emotional expressions of other people and to express and manage one's own emotions. It contributes to the success of a person in activities related to communication and interaction with people. Emotional intelligence has been studied largely in the context of organizational and education psychology, but less is known about the influence of genetics on it.

Objective

We aim to study emotional intelligence in carriers of different СОМТ, BDNF, DRD2, and HTR2A genotypes.

Design

We used three methods to measure emotional intelligence. Mayer-Salovey-Caruso Emotional Intelligence Test is a set of tasks with forced choice and frequency-based correct responses. We also applied two self-report questionnaires by Lyusin and Hall. We recruited 280 participants who took part in all three measures. We also identified their genotypes of the СОМТ, BDNF, DRD2, and HTR2A genes.

Results

Carriers of the Val/Met genotype of the COMT gene, A/A genotype of the HTR2A gene and C/C genotype of the DRD2 gene showed the highest level of emotional intelligence, while no differences were found between carriers of the BDNF genotypes. These data were obtained by using the Mayer-Salovey-Caruso Emotional Intelligence Test. Self-report scores of emotional intelligence did not differ between carriers of different genotypes across all four of the genes in question.

Conclusion

Mayer-Salovey-Caruso Emotional Intelligence Test scores were differed for carriers of some genotypes, whereas self-reported emotional intelligence scores did not differ between according to genotype.

A neural model of vulnerability and resilience to stress-related disorders linked to differential susceptibility

Expert opinion remains divided concerning the impact of putative risk factors on vulnerability to depression and other stress-related disorders. A large body of literature has investigated gene by environment interactions, particularly between the serotonin transporter polymorphism (5-HTTLPR) and negative environments, on the risk for depression. However, fewer studies have simultaneously investigated the outcomes in both negative and positive environments, which could explain some of the inconclusive findings. This is embodied by the concept of differential susceptibility, i.e., the idea that certain common gene polymorphisms, prenatal factors, and traits make some individuals not only disproportionately more susceptible and responsive to negative, vulnerability-promoting environments, but also more sensitive and responsive to positive, resilience-enhancing environmental conditions. Although this concept from the field of developmental psychology is well accepted and supported by behavioral findings, it is striking that its implementation in neuropsychiatric research is limited and that underlying neural mechanisms are virtually unknown. Based on neuroimaging studies that examined how factors mediating differential susceptibility affect brain function, we posit that environmental sensitivity manifests in increased salience network activity, increased salience and default mode network connectivity, and increased salience and central executive network connectivity. These changes in network function may bring about automatic exogenous attention for positive and negative stimuli and flexible attentional set-shifting. We conclude with a call to action; unraveling the neural mechanisms through which differential susceptibility factors mediate vulnerability and resilience may lead us to personalized preventive interventions.

Effects of traumatic stress in adolescence on PTSD-like behaviors, dendrite development, and H3K9me2/BDNF expression in the amygdala of male rats

Early detrimental experiences increase the risk of psychiatric disorders, including posttraumatic stress disorder (PTSD). In a previous experiment, we demonstrated that traumatic stress in adolescence triggers changes in the expression of the epigenetic marker H3K9me2 in the hippocampus and prefrontal cortex of adolescent and adult rats, which suppresses transcription of the brain-derived neurotrophic factor (Bdnf) gene that promotes dendrite development and synaptic growth. However, corresponding changes in the amygdala in response to traumatic stress in early life have not yet been fully elucidated. In the current study, we used the inescapable foot shock (IFS) procedure to establish a PTSD model. Half an hour after the end of electric shocks, intraperitoneal injection of the G9a enzyme inhibitor Unc0642, a small molecule inhibitor of EHMT2 that can decrease H3K9me2 expression, was applied to reverse the corresponding epigenetic changes. Exploratory behaviors, anxiety-like behavior, social communication ability, spatial exploration and memory were determined using the open field test (OFT), elevated plus maze (EPM) test, three-chamber sociability test (SIT), Morris water maze (MWM) test, and Y maze test (YMZ), respectively. Additionally, the levels of H3K9me2 and BDNF were measured by quantitative reverse transcription-polymerase chain reaction (qPCR) and Western blotting. Furthermore, neuronal development was examined using Golgi staining. The results showed that the IFS procedure induced anxiety-like and depression-like behaviors, social skills dysfunction, and spatial exploration and memory disorders. It also decreased the mRNA expression of BDNF and BDNF and increased the expression of H3K9me2 in the amygdala. More importantly, compared to unstressed animals, traumatic stress during adolescence induced dendrite maldevelopment in adolescent and adult rats. In summary, the present study indicates that early-life stress alters the epigenetic marker expression of H3K9me2 and decreases levels of BDNF in the amygdala, resulting in dendrite maldevelopment and a higher risk of mental disorders.

Neural processing of emotional facial stimuli in specific phobia: An fMRI study

BACKGROUND

Patients with specific phobia (SP) show altered brain activation when confronted with phobia-specific stimuli. It is unclear whether this pathogenic activation pattern generalizes to other emotional stimuli. This study addresses this question by employing a well-powered sample while implementing an established paradigm using nonspecific aversive facial stimuli.

METHODS

N = 111 patients with SP, spider subtype, and N = 111 healthy controls (HCs) performed a supraliminal emotional face-matching paradigm contrasting aversive faces versus shapes in a 3-T magnetic resonance imaging scanner. We performed region of interest (ROI) analyses for the amygdala, the insula, and the anterior cingulate cortex using univariate as well as machine-learning-based multivariate statistics based on this data. Additionally, we investigated functional connectivity by means of psychophysiological interaction (PPI).

RESULTS

Although the presentation of emotional faces showed significant activation in all three ROIs across both groups, no group differences emerged in all ROIs. Across both groups and in the HC > SP contrast, PPI analyses showed significant task-related connectivity of brain areas typically linked to higher-order emotion processing with the amygdala. The machine learning approach based on whole-brain activity patterns could significantly differentiate the groups with 73% balanced accuracy.

CONCLUSIONS

Patients suffering from SP are characterized by differences in the connectivity of the amygdala and areas typically linked to emotional processing in response to aversive facial stimuli (inferior parietal cortex, fusiform gyrus, middle cingulate, postcentral cortex, and insula). This might implicate a subtle difference in the processing of nonspecific emotional stimuli and warrants more research furthering our understanding of neurofunctional alteration in patients with SP.

The Course of Disease in Major Depressive Disorder Is Associated With Altered Activity of the Limbic System During Negative Emotion Processing

BACKGROUND

Brain functional alterations during emotion processing in patients with major depressive disorder (MDD) compared with healthy control subjects (HCs) are frequently reported. However, evidence for functional correlates of emotion processing with regard to MDD trajectories is scarce. This study investigates the role of lifetime disease course for limbic brain activation during negative emotional face processing in patients with MDD.

METHODS

In a large sample of patients with MDD (n = 333; 58.55% female) and HCs (n = 333; 60.06% female), brain activation was investigated during a negative emotional face-processing task within a cross-sectional design. Differences between HC and MDD groups were analyzed. Previous disease course, characterized by 2 components, namely hospitalization and duration of illness, was regressed on brain activation of the amygdala, (para-)hippocampus, and insula in patients with MDD.

RESULTS

Patients with MDD showed increased activation in the amygdala, insula, and hippocampus compared with HCs (all p values corrected for familywise error [p_FWE] < .045). The hospitalization component showed negative associations with brain activation in the bilateral insula (right: p_FWE = .026, left: p_FWE = .019) and (para-)hippocampus (right: p_FWE = .038, left: p_FWE = .031). No significant association was found for the duration of illness component (all p_FWE > .057).

CONCLUSIONS

This study investigated negative emotion processing in a large sample of patients with MDD and HCs. Our results confirm limbic hyperactivation in patients with MDD during negative emotion processing; however, this hyperactivation may resolve with a more severe lifetime disease course in the insula and (para-)hippocampus-brain regions involved in emotion processing and regulation. These findings need further replication in longitudinal studies.

The Influence of the BDNF Val66Met Polymorphism on the Association of Regular Physical Activity With Cognition Among Individuals With Diabetes

INTRODUCTION

Diabetes is associated with cognitive dysfunction that comes with substantial lifetime consequences, such as interference with diabetes self-management and reduced quality of life. Although regular physical activity has been consistently shown to enhance cognitive function among healthy subjects, significant interpersonal differences in exercise-induced cognitive outcomes have been reported among brain-derived neurotrophic factor (BDNF) Val/Val vs. Met carriers. However, the evidence on how the BDNF Val66Met variant influences the relationship between regular physical activity and cognition among individuals with diabetes is currently lacking.

METHODS

A total of 3,040 individuals with diabetes were included in this analysis using data from the Health and Retirement Study. Associations among moderate and vigorous physical activities (MVPA) and measures of cognitive function were evaluated using multivariable linear regression models within each stratum of the Val66Met genotypes.

RESULTS

MVPA was more strongly associated with total cognitive score, mental status, and words recall among Met/Met carriers, compared to Val/Val and Val/Met carriers.

CONCLUSIONS

This study provided preliminary findings on how BDNF variants may modulate the exercise-induced cognitive benefits among mid-aged and older adults with diabetes. Given the limitations of the current study, it is necessary for randomized controlled trials to stratify by BDNF genotypes to more conclusively determine whether Met carriers benefit more from increased physical activity. In addition, future research is needed to examine how the interplay of BDNF Val66Met variants, DNA methylation, and physical activity may have an impact on cognitive function among adults with diabetes.

Effects of childhood trauma experience and BDNF Val66Met polymorphism on brain plasticity relate to emotion regulation

Brain-derived neurotrophic factor (BDNF) Val66Met polymorphism may modulate the link between childhood trauma experience and psychopathology by altering trophic signaling on neuroplasticity. However, few multimodal magnetic resonance imaging (MRI) researches have investigated this gene-environment interaction on both structural and functional plasticity, thereby advancing knowledge about the etiology, prevention, and customized therapeutic directions of mental disease in individuals with childhood trauma experience. We recruited a large non-clinical sample of young adults that completed Childhood Trauma Questionnaire (CTQ), behavioral scores, multimodal MRI scans, and genotyping. Morphometric similarity network (MSN) and independent component analysis were adopted to quantify brain structural and functional changes. Gene-environment-brain-behavior relationships were identified by multiple regression and mediation effect analysis. CTQ score was positively associated with depression and anxiety scores. We found interactions on MSN in sensorimotor, temporal, and orbitofrontal cortex. For intra-network connectivity, significant interaction was noted in clusters within sensorimotor network. For inter-network connectivity, connectivity between dorsal attention network and salience network showed an interactive effect. For mean connectivity strength of each network, we found a main effect of CTQ score on self-reference network that was an outstanding mediator supporting the relationship between CTQ score and anxiety. Our findings demonstrate that childhood trauma and the BDNF Val66Met polymorphism are associated with brain plasticity involving emotion regulation, structurally and functionally, which may contribute to understanding psychotic mechanisms and predicting differential susceptibility. Imaging genetics may be useful as biomarkers to provide early assessment and guide cognitive interventions to avoid or decrease the risk of developing psychopathology.

Brain functional effects of electroconvulsive therapy during emotional processing in major depressive disorder

BACKGROUND

In treatment-resistant major depressive disorder (MDD), electroconvulsive therapy (ECT) is a treatment with high efficacy. While knowledge regarding changes in brain structure following ECT is growing, the effects of ECT on brain function during emotional processing are largely unknown.

OBJECTIVE

We investigated the effects of ECT on the activity of the anterior cingulate cortex (ACC) and amygdala during negative emotional stimuli processing and its association with clinical response.

METHODS

In this non-randomized longitudinal study, patients with MDD (n = 37) were assessed before and after treatment with ECT. Healthy controls (n = 37) were matched regarding age and gender. Functional magnetic resonance imaging (fMRI) was obtained twice, at baseline and after six weeks using a supraliminal face-matching paradigm. In order to evaluate effects of clinical response, additional post-hoc analyses were performed comparing responders to non-responders.

RESULTS

After ECT, patients with MDD showed a statistically significant increase in ACC activity during processing of negative emotional stimuli (p_FWE = .039). This effect was driven by responders (p_FWE = .023), while non-responders showed no increase. Responders also had lower pre-treatment ACC activity compared to non-responders (p_FWE = .025). No significant effects in the amygdala could be observed.

CONCLUSIONS

ECT leads to brain functional changes in the ACC, a relevant region for emotional regulation during processing of negative stimuli. Furthermore, baseline ACC activity might serve as a biomarker for treatment response. Findings are in accordance with recent studies highlighting properties of pre-treatment ACC to be associated with general antidepressive treatment response.

The role of BDNF methylation and Val66 Met in amygdala reactivity during emotion processing

Epigenetic alterations of the brain-derived neurotrophic factor (BDNF) gene have been associated with psychiatric disorders in humans and with differences in amygdala BDNF mRNA levels in rodents. This human study aimed to investigate the relationship between the functional BDNF-Val⁶⁶ Met polymorphism, its surrounding DNA methylation in BDNF exon IX, amygdala reactivity to emotional faces, and personality traits. Healthy controls (HC, n = 189) underwent functional MRI during an emotional face-matching task. Harm avoidance, novelty seeking and reward dependence were measured using the Tridimensional Personality Questionnaire (TPQ). Individual BDNF methylation profiles were ascertained and associated with several BDNF single nucleotide polymorphisms surrounding the BDNF-Val⁶⁶ Met, amygdala reactivity, novelty seeking and harm avoidance. Higher BDNF methylation was associated with higher amygdala reactivity (x = 34, y = 0, z = -26, t₍₁₆₆₎ = 3.00, TFCE = 42.39, p_(FWE) = .045), whereby the BDNF-Val⁶⁶ Met genotype per se did not show any significant association with brain function. Furthermore, novelty seeking was negatively associated with BDNF methylation (r = -.19, p = .015) and amygdala reactivity (r = -.17, p = .028), while harm avoidance showed a trend for a positive association with BDNF methylation (r = .14, p = .066). The study provides first insights into the relationship among BDNF methylation, BDNF genotype, amygdala reactivity and personality traits in humans, highlighting the multidimensional relations among genetics, epigenetics, and neuronal functions. The present study suggests a possible involvement of epigenetic BDNF modifications in psychiatric disorders and related brain functions, whereby high BDNF methylation might reduce BDNF mRNA expression and upregulate amygdala reactivity.