Association of peripheral BDNF level with cognition, attention and behavior in preschool children

BDNF, proBDNF and proBDNF/BDNF ratio with electroencephalographic abnormalities in children with attention deficit hyperactivity disorder: Possible relations to cognition and severity

Attention deficit hyperactivity disorder (ADHD) with and without subclinical epileptogenic discharges (SED) have been suggested to negatively affect cognitive abilities of children with ADHD. The role of brain-derived neurotrophic factor (BDNF) and its precursor proBDNF in ADHD is in need of being investigated. The aims were to evaluate the levels of serum BDNF, proBDNF and the proBDNF/BDNF ratio in addition to the potential impacts of SED on the children's cognitive abilities and the severity of ADHD. The included participants with ADHD were 30 children with normal electroencephalogram (EEG) (G1) and 30 children with SED (G2), together with 30 healthy children (G3). The cognitive abilities and severity of the disorder were evaluated. The biochemical measures were determined by ELISA. The presence of coexisting SED and nocturnal enuresis has led to a deleterious effect on cognitive processes but not on the severity. The focal epileptogenic discharge was the most common among children in G2. The levels of BDNF in Groups 1 and 2 were less than those in G3. The higher proBDNF/BDNF ratio could be related to the low BDNF levels rather than high proBDNF levels. The findings of this study highlight the importance of investigating the presence of SED and nocturnal enuresis in children with ADHD. Targeting strengthening of cognitive abilities in children with coexisting ADHD and SED is advised. The role of proBDNF in the pathophysiology of ADHD needs further investigation.

Expression Patterns of miRNAs in Egyptian Children with ADHD: Clinical Study with Correlation Analysis

ADHD has huge knowledge gaps concerning its etiology. MicroRNAs (miRNAs) provide promising diagnostic biomarkers of human pathophysiology and may be a novel therapeutic option. The aim was to investigate the levels of miR-34c-3p, miR-155, miR-138-1, miR-296-5p, and plasma brain-derived neurotrophic factor (BDNF) in a group of children with ADHD compared to neurotypicals and to explore correlations between these measures and some clinical data. The participants were children with ADHD in Group I (N = 41; age: 8.2 ± 2) and neurotypical ones in Group II (N = 40; age: 8.6 ± 2.5). Group I was subjected to clinical examination, the Stanford Binet intelligence scale-5, the preschool language scale, and Conner's parent rating scale-R. Measuring the expression levels of the miRNAs was performed by qRT-PCR for all participants. The BDNF level was measured by ELISA. The lowest scores on the IQ subtest were knowledge and working memory. No discrepancies were noticed between the receptive and expressive language ages. The highest scores on the Conner's scale were those for cognitive problems. Participants with ADHD exhibited higher plasma BDNF levels compared to controls (p = 0.0003). Expression patterns of only miR-34c-3p and miR-138-1 were downregulated with significant statistical differences (p˂0.01). However, expression levels of miR-296-5p showed negative correlation with the total scores of IQ (p = 0.03). MiR-34c-3p, miR-138-1, while BDNF showed good diagnostic potential. The downregulated levels of miR-34c-3p and miR-138-1, together with high BDNF levels, are suggested to be involved in the etiology of ADHD in Egyptian children. Gender differences influenced the expression patterns of miRNAs only in children with ADHD.

Negative relationship between brain-derived neurotrophic factor (BDNF) and attention: A possible elevation in BDNF level among high-altitude migrants

Objective

Brain-derived neurotrophic factor (BDNF), a member of the neurotrophic family that plays a vital role in regulating neuronal activity and synaptic plasticity in the brain, affects attention. However, studies investigating the association between BDNF and attention in long-term high-altitude (HA) migrants are limited in the literature. As HA affects both BDNF and attention, the relationship between these factors becomes more complex. Therefore, this study aimed to evaluate the relationship between peripheral blood concentrations of BDNF and the three attentional networks in both behavioral and electrical aspects of the brain in long-term HA migrants.

Materials and methods

Ninety-eight Han adults (mean age: 34.74 ± 3.48 years, 51 females and 47 males, all have lived at Lhasa for 11.30 ± 3.82 years) were recruited in this study. For all participants, the serum BDNF levels were assessed using enzyme-linked immunosorbent assay; event-related potentials (N1, P1, and P3) were recorded during the Attentional Networks Test, which was used as the measure of three attentional networks.

Results

Executive control scores were negatively correlated with P3 amplitude (r = -0.20, p = 0.044), and serum BDNF levels were positively correlated with executive control scores (r = 0.24, p = 0.019) and negatively correlated with P3 amplitude (r = -0.22, p = 0.027). Through grouping of BDNF levels and three attentional networks, executive control was found to be significantly higher in the high BDNF group than in the low BDNF group (p = 0.010). Different BDNF levels were associated with both orienting scores (χ² = 6.99, p = 0.030) and executive control scores (χ² = 9.03, p = 0.011). The higher the BDNF level, the worse was the executive function and the lower was the average P3 amplitude and vice versa. Females were found to have higher alerting scores than males (p = 0.023).

Conclusion

This study presented the relationship between BDNF and attention under HA. The higher the BDNF level, the worse was the executive control, suggesting that after long-term exposure to HA, hypoxia injury of the brain may occur in individuals with relatively higher BDNF levels, and this higher BDNF level may be the result of self-rehabilitation tackling the adverse effects brought by the HA environment.

Intricate role of sleep deprivation in modulating depression: focusing on BDNF, VEGF, serotonin, cortisol, and TNF-α

In this review article, we aimed to discuss intricate roles of SD in modulating depression in preclinical and clinical studies. Decades of research have shown the inconsistent effects of SD on depression, focusing on SD duration. However, inconsistent role of SD seems to be more complicated, and SD duration cannot be the only one factor. Regarding this issue, we chose some important factors involved in the effects of SD on cognitive functions and mood including brain-derived neurotrophic factor (BDNF), vascular endothelial growth factor (VEGF), serotonin, cortisol, and tumor necrosis factor-alpha (TNF-α). It was concluded that SD has a wide-range of inconsistent effects on BDNF, VEGF, serotonin, and cortisol levels. It was noted that BDNF diurnal rhythm is significantly involved in the modulatory role of SD in depression. Furthermore, the important role of VEGF in blood-brain barrier permeability which is involved in modulating depression was discussed. It was also noted that there is a negative correlation between cortisol and BDNF that modulates depression. Eventually, it was concluded that TNF-α regulates sleep/wake cycle and is involved in the vulnerability to cognitive and behavioral impairments following SD. TNF-α also increases the permeability of the blood-brain barrier which is accompanied by depressive behavior. In sum, it was suggested that future studies should focus on these mechanisms/factors to better investigate the reasons behind intricate roles of SD in modulating depression.

Lights on for Autism: Exploring Photobiomodulation as an Effective Therapeutic Option

Autism is a neurodevelopmental condition that starts in childhood and continues into adulthood. The core characteristics include difficulties with social interaction and communication, together with restricted and repetitive behaviours. There are a number of key abnormalities of brain structure and function that trigger these behavioural patterns, including an imbalance of functional connectivity and synaptic transmission, neuronal death, gliosis and inflammation. In addition, autism has been linked to alterations in the gut microbiome. Unfortunately, as it stands, there are few treatment options available for patients. In this mini-review, we consider the effectiveness of a potential new treatment for autism, known as photobiomodulation, the therapeutic use of red to near infrared light on body tissues. This treatment has been shown in a range of pathological conditions-to improve the key changes that characterise autism, including the functional connectivity and survival patterns of neurones, the patterns of gliosis and inflammation and the composition of the microbiome. We highlight the idea that photobiomodulation may form an ideal treatment option for autism, one that is certainly worthy of further investigation.

The Relationship Between Trichotillomania and Serum Brain-Derived Neurotrophic Factor Levels in Children and Adolescents: A Case-Control Study

OBJECTIVE

Trichotillomania (TTM) is a clinical psychiatric manifestation involving significant hair loss in association with recurrent hair-pulling behavior, the etiology of which is still unknown. Insufficiency or disorder in the synthesis of brain-derived neurotrophic factor (BDNF) is reported to be potentially associated with neurological, neurodegenerative, and psychiatric diseases in humans and animals. This study examines the relationship between serum BDNF levels and TTM.

METHODS

Ninety-four children and adolescents, 47 patients with TTM and a 47-member control group, were included in the study. Participants were administered the Schedule for Affective Disorders and Schizophrenia for School-Aged Children (6-18 Years) Present and Lifetime Version, and the members of the case group completed the Clinical Global Impression scale. Serum BDNF levels were determined from blood specimens collected from the study and control groups, and the results were subjected to statistical analysis.

RESULTS

Serum BDNF levels were 11.06 ± 1.9 ng/mL in the TTM group and 13.78 ± 2.2 ng/mL in the control group. Serum BDNF was significantly lower in the case group than in the control group. Moderate negative correlation was also determined between Clinical Global Impression scores and serum BDNF levels in the case group.

CONCLUSIONS

Low serum BDNF was associated with TTM and the severity thereof. Furthermore, more extensive studies are needed to elucidate this association.

New Frontiers in Neurodegeneration and Regeneration Associated with Brain-Derived Neurotrophic Factor and the rs6265 Single Nucleotide Polymorphism

Brain-derived neurotrophic factor is an extensively studied neurotrophin implicated in the pathology of multiple neurodegenerative and psychiatric disorders including, but not limited to, Parkinson’s disease, Alzheimer’s disease, Huntington’s disease, traumatic brain injury, major de-pressive disorder, and schizophrenia. Here we provide a brief summary of current knowledge on the role of BDNF and the common human single nucleotide polymorphism, rs6265, in driving the pathogenesis and rehabilitation in these disorders, as well as the status of BDNF-targeted therapies. A common trend has emerged correlating low BDNF levels, either detected within the central nervous system or peripherally, to disease states, suggesting that BDNF replacement therapies may hold clinical promise. In addition, we introduce evidence for a distinct role of the BDNF pro-peptide as a biologically active ligand and the need for continuing studies on its neurological function outside of that as a molecular chaperone. Finally, we highlight the latest research describing the role of rs6265 expression in mechanisms of neurodegeneration as well as paradoxical advances in the understanding of this genetic variant in neuroregeneration. All of this is discussed in the context of personalized medicine, acknowledging there is no “one size fits all” therapy for neurodegenerative or psychiatric disorders and that continued study of the multiple BDNF isoforms and genetic variants represents an avenue for discovery ripe with therapeutic potential.

An Integrated Analysis of Clinical, Genomic, and Imaging Features Reveals Predictors of Neurocognitive Outcomes in a Longitudinal Cohort of Pediatric Cancer Survivors, Enriched with CNS Tumors (Rad ART Pro)

Background

Neurocognitive deficits in pediatric cancer survivors occur frequently; however, individual outcomes are unpredictable. We investigate clinical, genetic, and imaging predictors of neurocognition in pediatric cancer survivors, with a focus on survivors of central nervous system (CNS) tumors exposed to radiation.

Methods

One hundred eighteen patients with benign or malignant cancers (median diagnosis age: 7; 32% embryonal CNS tumors) were selected from an existing multi-institutional cohort (RadART Pro) if they had: 1) neurocognitive evaluation; 2) available DNA; 3) standard imaging. Utilizing RadART Pro, we collected clinical history, genomic sequencing, CNS imaging, and neurocognitive outcomes. We performed single nucleotide polymorphism (SNP) genotyping for candidate genes associated with neurocognition: COMT, BDNF, KIBRA, APOE, KLOTHO. Longitudinal neurocognitive testing were performed using validated computer-based CogState batteries. The imaging cohort was made of patients with available iron-sensitive (n = 28) and/or T2 FLAIR (n = 41) sequences. Cerebral microbleeds (CMB) were identified using a semi-automated algorithm. Volume of T2 FLAIR white matter lesions (WML) was measured using an automated method based on a convolutional neural network. Summary statistics were performed for patient characteristics, neurocognitive assessments, and imaging. Linear mixed effects and hierarchical models assessed patient characteristics and SNP relationship with neurocognition over time. Nested case-control analysis was performed to compare candidate gene carriers to non-carriers.

Results

CMB presence at baseline correlated with worse performance in 3 of 7 domains, including executive function. Higher baseline WML volumes correlated with worse performance in executive function and verbal learning. No candidate gene reliably predicted neurocognitive outcomes; however, APOE ϵ4 carriers trended toward worse neurocognitive function over time compared to other candidate genes and carried the highest odds of low neurocognitive performance across all domains (odds ratio 2.85, P=0.002). Hydrocephalus and seizures at diagnosis were the clinical characteristics most frequently associated with worse performance in neurocognitive domains (5 of 7 domains). Overall, executive function and verbal learning were the most frequently negatively impacted neurocognitive domains.

Conclusion

Presence of CMB, APOE ϵ4 carrier status, hydrocephalus, and seizures correlate with worse neurocognitive outcomes in pediatric cancer survivors, enriched with CNS tumors exposed to radiation. Ongoing research is underway to verify trends in larger cohorts.

Cord serum brain-derived neurotrophic factor levels at birth associate with temperament outcomes at one year

Altered serum levels of brain-derived neurotrophic factor (BDNF) are consistently linked with neurological disorders. BDNF is also increasingly implicated in the pathogenesis of neurodevelopmental disorders, particularly those found more frequently in males. At birth, male infants naturally have significantly lower serum BDNF levels (∼10-20% lower than females), which may render them more vulnerable to neurodevelopmental disorders. We previously characterized serum BDNF levels in mothers and their newborn infants as part of the Grown in Wales Study. Here, we analyzed whether cord serum BDNF levels at birth correlate with sex-specific outcomes at one year. The Bayley Scale of Infant Development, Third Edition (BSID-III) and Laboratory Temperament Assessment Battery (Lab-TAB) tasks were used to assess infant behavior and neurodevelopment at 12-14 months (mean ± SD: 13.3 ± 1.6 months; 46% male; n = 56). We found no relationship between serum BDNF levels at birth and BSID-III neurodevelopmental outcomes (cognitive or language), nor with infant behaviors in the Lab-TAB unpredictable mechanical toy or maternal separation tasks. In the sustained attention task, there was a significant positive relationship between serum BDNF and infant negative affect (B = 0.06, p = 0.018) and, for boys only, between serum BDNF and intensity of facial interest (B = 0.03, p = 0.005). However, only the latter remained after correction for multiple testing. This sex-specific association between cord serum BDNF and a parameter of attention at 12-14 months provides some support for the hypothesis that reduced serum BDNF levels at birth are linked to an increased risk for neurodevelopmental disorders.

Maternal prenatal depressive symptoms and toddler behavior: an umbilical cord blood epigenome-wide association study

Children of mothers with prenatal depressive symptoms (PND) have a higher risk of behavioral problems; fetal programming through DNA methylation is a possible underlying mechanism. This study investigated DNA methylation in cord blood to identify possible "at birth" signatures that may indicate susceptibility to behavioral problems at 18 months of age. Cord blood was collected from 256 children of mothers who had self-reported on symptoms of depression during pregnancy and the behavior of their child at 18 months of age. Whole genome DNA methylation was assessed using Illumina MethylationEPIC assay. The mother and child pairs were categorized into four groups, based on both self-reported depressive symptoms, PND or Healthy control (HC), and scores from the Child Behavior checklist (high or low for internalizing, externalizing, and total scores). Adjustments were made for batch effects, cell-type, and clinical covariates. Differentially methylated sites were identified using Kruskal-Wallis test, and Benjamini-Hochberg adjusted p values < 0.05 were considered significant. The analysis was also stratified by sex of the child. Among boys, we observed higher and correlated DNA methylation of one CpG-site in the promoter region of TPP1 in the HC group, with high externalizing scores compared to HC with low externalizing scores. Boys in the PND group showed lower DNA methylation in NUDT15 among those with high, compared to low, internalizing scores; the DNA methylation levels of CpGs in this gene were positively correlated with the CBCL scores. Hence, the differentially methylated CpG sites could be of interest for resilience, regardless of maternal mental health during pregnancy. The findings are in a relatively healthy study cohort, thus limiting the possibility of detecting strong effects associated with behavioral difficulties. This is the first investigation of cord blood DNA methylation signs of fetal programming of PND on child behavior at 18 months of age and thus calls for independent replications.

Neurotrophic Factors and Brain Health in Children with Overweight and Obesity: The Role of Cardiorespiratory Fitness

ABSTRACTNeurotrophic factors and cardiorespiratory fitness are both considered important in developmental trajectories but their link to brain health remains poorly understood. The aims of the study were to examine whether levels of plasma-derived neurotrophic factors were associated with brain health indicators in children with overweight or obesity; and to test whether these associations were moderated by cardiorespiratory fitness. 100 children (41% girls) were included in this analysis. Plasma levels of brain-derived neurotrophic factor, insulin-like growth factor-1, vascular endothelial growth factor A, and epidermal growth factor were determined by XMap technology. Academic performance and executive function were assessed using validated neuropsychological tests. Hippocampal volume was measured using magnetic resonance imaging. Cardiorespiratory fitness was assessed using the 20-m Shuttle Run Test. Insulin-like growth factor-1 was positively associated with cognitive flexibility. Stratified analyses by fitness categories (i.e., unfit vs. fit) showed that brain-derived neurotrophic factor was positively associated with right posterior hippocampal volume in fit children, and epidermal growth factor was negatively associated with right hippocampal, and right anterior hippocampal volumes in their unfit peers, with a moderating role of cardiorespiratory fitness in these associations. However, all these significant associations disappeared after correction for multiple comparisons. The association between neurotrophic factors and brain health indicators in children with overweight/obesity was neither strong nor consistent. These results could help enhance our understanding of determinants of brain health in children with overweight/obesity.Trial registration: ClinicalTrials.gov identifier: NCT02295072..

Evaluation of the Relationship Between BDNF Val66Met Gene Polymorphism and Attention Deficit Hyperactivity Disorder: A Meta-Analysis

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is a common neurobehavioral disorder in childhood. Brain-derived neurotrophic factor (BDNF) is widely distributed in the central nervous system and plays an important role in neural development. Despite several previous studies have examined the association between the Val66Met polymorphism BDNF and ADHD, the results are conflicting.

OBJECTIVE

This study aimed to evaluate the association between Val66Met polymorphism and ADHD in case-control and transmission disequilibrium test (TDT) studies using a meta-analysis.

METHODS

Keywords "rs6265" or "Val66Met" and "Attention deficit hyperactivity disorder" were used to search in the PubMed, Embase, Web of Science, Wanfang, and China National Knowledge Infrastructure databases before April 2021. Genotype data were extracted to calculate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Fifteen studies, comprising of 8,692 samples (containing 4,364 cases, 4,328 controls) and 1,578 families were included and results demonstrated that rs6265 was not associated with susceptibility to ADHD (OR = 0.95, 95% CI: 0.87-1.04, P = 0.291). Stratified analyses by study design, ethnicity, and sample size further supported that rs6265 was not associated with ADHD.

CONCLUSION

The present study shows that the polymorphism of the BDNF Val66Met gene is not associated with susceptibility to ADHD.

Association of BDNF levels with IQ: comparison of S100B and BDNF levels in typically developing children and subjects with neurologically normal nonsyndromic intellectual disability

BACKGROUND

Brain-derived neurotrophic factor (BDNF) and S100B are reported to play an important role in neurodevelopment and may contribute to developmental pathogenesis in neuropsychiatric diseases. In this study, we aimed to examine the possible roles of BDNF and S100B in the pathogenesis of nonsyndromic intellectual disability (NS-ID) and their relationship with cognitive performance.

METHODS

Thirty-three patients with intellectual disability (ID) and 30 typically developing children were compared. BDNF and S100B serum levels were measured with ELISA. The Wechsler Intelligence Scale for Children-Revised Short form (WISC-R) and Leiter intelligence test were administered to determine the intelligence levels of subjects. Leiter intelligence test was applied to 10 participants (30.31%) in the ID group because they had speech and communication problems. All other participants underwent WISC-R.

RESULTS

Brain-derived neurotrophic factor levels were found to be significantly low in the patient group (mean ± SD, 67.43 ± 29.74 pg/mL) compared with the control group (94.67 ± 32.55 pg/mL) (P = 0.002). When S100B is assessed, there was no significant difference found between the patient group (335.05 ± 279.89 pg/mL) and control group (295.30 ± 146.55 pg/mL) (P = 0.901). There was a significant positive correlation between BDNF and performance IQ (r = 0.424 and P = 0.001) in all participants. In addition, positive correlations were found between BDNF levels and initiating speech time (r = -0.369 and P = 0.003).

CONCLUSIONS

Brain-derived neurotrophic factor deficiency is proposed to have a possible role in the pathology of NS-ID. High BDNF levels may be associated with better cognitive performance.

Sex-specific neurotoxic effects of heavy metal pollutants: Epidemiological, experimental evidence and candidate mechanisms

The heavy metals lead (Pb), mercury (Hg), and cadmium (Cd) are ubiquitous environmental pollutants and are known to exert severe adverse impacts on the nervous system even at low concentrations. In contrast, the heavy metal manganese (Mn) is first and foremost an essential nutrient, but it becomes neurotoxic at high levels. Neurotoxic metals also include the less prevalent metalloid arsenic (As) which is found in excessive concentrations in drinking water and food sources in many regions of the world. Males and females often differ in how they respond to environmental exposures and adverse effects on their nervous systems are no exception. Here, we review the different types of sex-specific neurotoxic effects, such as cognitive and motor impairments, that have been attributed to Pb, Hg, Mn, Cd, and As exposure throughout the life course in epidemiological as well as in experimental toxicological studies. We also discuss differential vulnerability to these metals such as distinctions in behaviors and occupations across the sexes. Finally, we explore the different mechanisms hypothesized to account for sex-based differential susceptibility including hormonal, genetic, metabolic, anatomical, neurochemical, and epigenetic perturbations. An understanding of the sex-specific effects of environmental heavy metal neurotoxicity can aid in the development of more efficient systematic approaches in risk assessment and better exposure mitigation strategies with regard to sex-linked susceptibilities and vulnerabilities.

TH2 sensitization in the skin-gut-brain axis: How early-life Th2-mediated inflammation may negatively perpetuate developmental and psychologic abnormalities

We recently reported children with comorbid atopic dermatitis (AD), asthma, allergic rhinitis, and food allergies displaying a 2.7-fold increase in developmental delays.² To this end, we hypothesize unregulated increases in T helper-2 (Th2)-driven inflammation, such as those seen in atopic diseases, can exert deleterious effects on the developing brain. Recognizing that available information is incomplete and that many potential associations are not firmly established, we speculate these effects underlie the association between Th2 sensitization and cognitive dysfunction in children. In this review, we explore the role of Th2 sensitization in the skin-gut-brain axis and explain how it can lead to reduced connectivity and transmission in the developing brain. With a focus on AD, we explore the association between Th2 sensitization and developmental abnormalities such as developmental delays, memory impairment, autism spectrum disorder (ASD), and epilepsy/seizures. As such, we review the available literature to examine the impact of increased IL-4 exposure in early life on the brain. We explore the possible association between Th2 sensitization and psychologic dysfunction such as attention-deficit/hyperactivity disorder (ADHD), depression, anxiety, and suicidal ideation. We also examine the impact that increased exposure to glucocorticoids and neurotrophins in early life exerts on the developing brain. Last, we discuss future directions for the advancement of our knowledge as a scientific community including possible interventions to reduce developmental and psychologic aberrations in children.

Short-term effects of a Mediterranean-style dietary pattern on cognition and mental well-being: a systematic review of clinical trials

Although the long-term effects of a Mediterranean-style dietary pattern (MDP) on cognition and overall mental well-being have been consistently described, the short-term effects of the MDP on cognitive performance, mood and anxiety have not been as widely reviewed. Therefore, the aims of this systematic review were to synthesise the evidence from randomised controlled trials (RCT), to examine whether a MDP can alter cognition and overall mental well-being in the short-term (up to 10 d). This will also be used to identify research gaps and to inform the design of future acute RCT in the area. Ovid Embase, Ovid MEDLINE and Web of Science Core Collection were searched from inception to 8 December 2020. The data were synthesised narratively with no quantitative synthesis. The detailed protocol is available on PROSPERO, with the registration number CRD42021221085. A total of 3002 studies were initially identified. After the deduplication and screening stages, four studies (three articles and one conference proceeding) were eligible to be included. Despite the very limited data obtained, the literature suggests that a MDP can improve cognition and mood in the short-term. Specifically, improvements in attention, alertness and contentment were consistently reported. A MDP appears as a promising strategy to improve short-term cognitive and mental health. A limitation of this review is the small number of studies identified; therefore, future studies are required to confirm these initial novel findings and to provide granularity as to which domains are most responsive and in which population subgroups.

Serum Brain-Derived Neurotrophic Factor, Glial-Derived Neurotrophic Factor, Nerve Growth Factor and Neurotrophin-3 Levels in Preschool Children with Language Disorder

INTRODUCTION

Accumulating studies demonstrate that neurotrophins may play a crucial role in a variety of neurodevelopmental disorders. However, little data are available regarding the potential role of neurotrophins in language disorder (LD). This study aimed to investigate serum brain-derived neurotrophic factor (BDNF), glial-derived neurotrophic factor (GDNF), nerve growth factor (NGF) and neurotrophin-3 (NTF3) levels in preschool children with LD.

METHODS

A total of 43 cases with LD and 43 healthy controls aged 18 to 60 months were enrolled in the study. The development levels and psychiatric symptoms of the children were determined by the Ankara Developmental Screening Inventory and Child Behavior Checklist 1.5-5, respectively. Serum neurotrophin levels were assessed by enzyme-linked immunosorbent assay kits.

RESULTS

Serum GDNF and NGF levels were significantly higher, serum BDNF and NTF3 levels were significantly lower in the LD group than in the control group. However, with logistic regression analyses, only negative relationship of BDNF and NTF3 levels with the presence of LD remained significant after accounting for the confounders including development level and coexisting psychiatric symptoms.

CONCLUSIONS

These results suggest that low BDNF and NTF3 levels have independent negative relationships with LD, which could be contribute to etiopathogenesis of the disorder.

Relationship between exclusive breastfeeding and brain-derived neurotrophic factor in children

Objective

A positive relationship between breastfeeding and brain-derived neurotrophic factor (BDNF) in infants has been suggested due to the presence of BDNF in human milk. This study aimed to determine the relationship between exclusive breastfeeding and BDNF serum levels in Spanish schoolchildren.

Methods

A cross-sectional analysis including 202 schoolchildren, aged eight to 11 years, from Cuenca, Spain, was conducted. Information on sociodemographic and anthropometric variables, sexual maturation, birth weight and exclusive breastfeeding (‘no exclusive breastfeeding’, and exclusive breastfeeding for ≤6 and >6 months), and BDNF serum levels using an ELISA method were obtained. Covariance analyses (ANCOVA) were conducted to examine the relationship between serological BDNF and exclusive breastfeeding after controlling for potential confounders.

Results

ANCOVA models showed no significant differences in BDNF levels between children who were exclusively breastfed for more than six months versus those who were not (p > 0.05). No significant differences were observed by age group (eight to nine years versus 10 to 11 years; p > 0.05). Additionally, no clear negative trend in BDNF serum levels according to sexual maturation categories was found (p > 0.05).

Conclusion

These findings suggest that exclusive breastfeeding does not have a significant positive association on BDNF from eight to 11 years, since children who were exclusively breastfed did not have significantly higher BDNF levels than those who were not exclusively breastfed. Likewise, BDNF levels were not found to be negatively affected by hormonal development. Future research should examine the influence of exclusive breastfeeding on BDNF over the different developmental stages.

Bisphenol A and its analogues: A comprehensive review to identify and prioritize effect biomarkers for human biomonitoring

Human biomonitoring (HBM) studies have demonstrated widespread and daily exposure to bisphenol A (BPA). Moreover, BPA structural analogues (e.g. BPS, BPF, BPAF), used as BPA replacements, are being increasingly detected in human biological matrices. BPA and some of its analogues are classified as endocrine disruptors suspected of contributing to adverse health outcomes such as altered reproduction and neurodevelopment, obesity, and metabolic disorders among other developmental and chronic impairments. One of the aims of the H2020 European Human Biomonitoring Initiative (HBM4EU) is the implementation of effect biomarkers at large scales in future HBM studies in a systematic and standardized way, in order to complement exposure data with mechanistically-based biomarkers of early adverse effects. This review aimed to identify and prioritize existing biomarkers of effect for BPA, as well as to provide relevant mechanistic and adverse outcome pathway (AOP) information in order to cover knowledge gaps and better interpret effect biomarker data. A comprehensive literature search was performed in PubMed to identify all the epidemiologic studies published in the last 10 years addressing the potential relationship between bisphenols exposure and alterations in biological parameters. A total of 5716 references were screened, out of which, 119 full-text articles were analyzed and tabulated in detail. This work provides first an overview of all epigenetics, gene transcription, oxidative stress, reproductive, glucocorticoid and thyroid hormones, metabolic and allergy/immune biomarkers previously studied. Then, promising effect biomarkers related to altered neurodevelopmental and reproductive outcomes including brain-derived neurotrophic factor (BDNF), kisspeptin (KiSS), and gene expression of nuclear receptors are prioritized, providing mechanistic insights based on in vitro, animal studies and AOP information. Finally, the potential of omics technologies for biomarker discovery and its implications for risk assessment are discussed. To the best of our knowledge, this is the first effort to comprehensively identify bisphenol-related biomarkers of effect for HBM purposes.

Assessment of BDNF serum levels as a diagnostic marker in children with autism spectrum disorder

There has been a significant increase in autism spectrum disorder (ASD) in the last decades that cannot be exclusively attributed to better diagnosis and an increase in the communication of new cases. Patients with ASD often show dysregulation of proteins associated with synaptic plasticity, notably brain-derived neurotrophic factor (BDNF). The objective of the present study was to analyze BDNF serum concentration levels in children with classic forms autism and a healthy control group to determine if there is a correlation between ASD and BDNF serum levels. Forty-nine children with severe classic form of autism, and 37 healthy children were enrolled in the study. Blood samples, from both patients and controls, were collected and BNDF levels from both groups were analyzed. The average BDNF serum concentration level was statistically higher for children with ASD (P < 0.000) compared to the control group. There is little doubt that BDNF plays a role in the pathophysiology of ASD development and evolution, but its brain levels may fluctuate depending on several known and unknown factors. The critical question is not if BDNF levels can be considered a prognostic or diagnostic marker of ASD, but to determine its role in the onset and progression of this disorder.

An association study of severity of intellectual disability with peripheral biomarkers of disabled children in a rehabilitation home, Kolkata, India

The current investigation has identified the biomarkers associated with severity of disability and correlation among plethora of systemic, cellular and molecular parameters of intellectual disability (ID) in a rehabilitation home. The background of study lies with the recent clinical evidences which identified complications in ID. Various indicators from blood and peripheral system serve as potential surrogates for disability related changes in brain functions. ID subjects (Male, age 10 ± 5 yrs, N = 45) were classified as mild, moderate and severe according to the severity of disability using standard psychometric analysis. Clinical parameters including stress biomarkers, neurotransmitters, RBC morphology, expressions of inflammatory proteins and neurotrophic factor were estimated from PBMC, RBC and serum. The lipid peroxidation of PBMC and RBC membranes, levels of serum glutamate, serotonin, homocysteine, ROS, lactate and LDH-A expression increased significantly with severity of ID whereas changes in RBC membrane β-actin, serum BDNF, TNF-α and IL-6 was found non-significant. Structural abnormalities of RBC were more in severely disabled children compared to mildly affected ones. The oxidative stress remained a crucial factor with severity of disability. This is confirmed not only by RBC alterations but also with other cellular dysregulations. The present article extends unique insights of how severity of disability is correlated with various clinical, cellular and molecular markers of blood. This unique study primarily focuses on the strong predictors of severity of disability and their associations via brain-blood axis.

The effects of hookah/waterpipe smoking on general health and the cardiovascular system

Hookah or waterpipe smoking or use is an emerging trend in the US population, especially among the youth. The misperception of hookah being less harmful than cigarettes and the availability of different but "appealing" flavors are considered among the main reasons for this trend. Hookah users however are exposed to many of the same toxic compounds/by-products as cigarette users, but at dramatically higher levels, which might lead to more severe negative health effects. In fact, hookah users are at risks of infections, cancers, lung disease, and other medical conditions. Moreover, because of the overlapping toxicant/chemical profile to conventional cigarettes, hookah smoke effects on the cardiovascular system are thought to be comparable to those of conventional cigarettes. A major source of tobacco addiction is nicotine, whose levels in hookah are extremely variable as they depend on the type of tobacco used. Taken together, in this review of literature, we will provide insights on the negative health effects of hookah in general, with a focus on what is known regarding its impact on the cardiovascular system.

Reconstruction and Analysis of Gene Networks of Human Neurotransmitter Systems Reveal Genes with Contentious Manifestation for Anxiety, Depression, and Intellectual Disabilities

Background: The study of the biological basis of anxiety, depression, and intellectual disabilities in humans is one of the most actual problems of modern neurophysiology. Of particular interest is the study of complex interactions between molecular genetic factors, electrophysiological properties of the nervous system, and the behavioral characteristics of people. The neurobiological understanding of neuropsychiatric disorders requires not only the identification of genes that play a role in the molecular mechanisms of the occurrence and course of diseases, but also the understanding of complex interactions that occur between these genes. A systematic study of such interactions obviously contributes to the development of new methods of diagnosis, prevention, and treatment of disorders, as the orientation to allele variants of individual loci is not reliable enough, because the literature describes a number of genes, the same alleles of which can be associated with different, sometimes extremely different variants of phenotypic traits, depending on the genetic background, of their carriers, habitat, and other factors. Results: In our study, we have reconstructed a series of gene networks (in the form of protein–protein interactions networks, as well as networks of transcription regulation) to build a model of the influence of complex interactions of environmental factors and genetic risk factors for intellectual disability, depression, and other disorders in human behavior. Conclusion: A list of candidate genes whose expression is presumably associated with environmental factors and has potentially contentious manifestation for behavioral and neurological traits is identified for further experimental verification.

Peripheral Brain-Derived Neurotrophic Factor and Contactin-1 Levels in Patients with Attention-Deficit/Hyperactivity Disorder

Brain-derived neurotrophic factor (BDNF) facilitates neuronal growth and plasticity, and is crucial for learning and memory. Contactin-1 (CNTN1) is a member of the subfamily of neural immunoglobulin and is involved in the formation of axon connections in the developing nervous system. This cross-sectional study investigates whether BDNF and CNTN1 affect susceptibility to attention deficit/hyperactivity disorder (ADHD). A total of 136 drug-naïve patients with ADHD (108 boys and 28 girls) and 71 healthy controls (45 boys and 26 girls) were recruited. Blood samples were obtained to measure the plasma levels of BDNF and CNTN1 in each child. We found that BDNF levels in the ADHD boys exceeded those in the control boys, but BDNF levels in the ADHD girls were lower than those in the control girls. Boys who had higher BDNF levels performed worse on the Wechsler Intelligence Scale for Children—Fourth Edition, but girls who had higher BDNF levels made fewer omission errors in the Conners’ Continuous Performance Test. However, CNTN1 level did not differ significantly between patients and controls, and were not correlated to ADHD characteristics, regardless of gender. The findings suggest BDNF may influence sex-specific susceptibility to ADHD, but CNTN1 was not associated with ADHD pathophysiology.

Exploring the role of BDNF DNA methylation and hydroxymethylation in patients with obsessive compulsive disorder

Obsessive-compulsive disorder (OCD) is a clinically heterogeneous neuropsychiatric condition associated with profound disability, whose susceptibility, stemming from genetic and environmental factors that intersect with each other, is still under investigation. In this perspective, we sought to explore the transcriptional regulation of Brain Derived Neurotrophic Factor (BDNF), a promising candidate biomarker in both development and etiology of different neuropsychiatric conditions, in peripheral blood mononuclear cells from OCD patients and healthy controls. In particular, we focused on BDNF gene expression and interrogated in depth DNA methylation and hydroxymethylation at gene promoters (exons I, IV and IX) in a sample of OCD patients attending a tertiary OCD Clinic to receive guidelines-recommended treatment, and matched controls. Our preliminary data showed a significant increase in BDNF gene expression and a significant correlation with changes in the two epigenetic modifications selectively at promoter exon I, with no changes in the other promoters under study. We can conclude that transcriptional regulation of BDNF in OCD engages epigenetic mechanisms, and can suggest that this is likely evoked by the long-term pharmacotherapy. It is important to underline that many different factors need to be taken into account (i.e. age, sex, duration of illness, treatment), and thus further studies are mandatory to investigate their role in the epigenetic regulation of BDNF gene. Of note, we provide unprecedented evidence for the importance of analyzing 5-hydroxymethylcytosine levels to correctly evaluate 5-methylcytosine changes.

Multiple epigenetic biomarkers for evaluation of students' academic performance

Several reports have shown that methyl CpG-binding protein 2 (MeCP2), brain-derived neurotrophic factor (BDNF), phospho-cAMP response element-binding protein (p-CREB) and microRNAs may be important in regulating academic performance because of their roles in neuropsychiatry and cognitive diseases. The first goal of this study was to explore the associations among MeCP2, BDNF, CREB and academic performance. This study also examined the pathway responsible for the effects of MeCP2, BDNF, p-CREB and microRNAs on academic performance. Scores from the basic competency test, an annual national competitive entrance examination, were used to evaluate academic performance. Subjects' plasma RNA was extracted and analyzed. This study determined that participants in the higher academic performance group had a significant difference in MECP2 mRNA expression compared with the lower academic performance group. We then used neuronal human derived neuroblastoma cell line (SH-SY5Y) cells with inducible MeCP2 expression from a second copy of the gene as a gain-of-function model and found that MeCP2 overexpression positively affected p-CREB and BDNF expression initially. After negative feedback, the p-CREB and BDNF levels subsequently decreased. In the neuronal phenotype examination, we found a significant reduction in total outgrowth and branches in MeCP2-induced cells compared with noninduced cells. This work describes pathways that may be responsible for the effects of MeCP2, BDNF, p-CREB and microRNAs on academic performance. These results may shed light on the development of promising clinical treatment strategies in the area of neuropsychological adjustment.

Prenatal intimate partner violence exposure predicts infant biobehavioral regulation: Moderation by the brain-derived neurotrophic factor (BDNF) gene

The ability to regulate stress is a critical developmental milestone of early childhood that involves a set of interconnected behavioral and physiological processes and is influenced by genetic and environmental stimuli. Prenatal exposure to traumatic stress and trauma, including intimate partner violence (IPV), increases risk for offspring biobehavioral regulation problems during childhood and adolescence. Although individual differences in susceptibility to prenatal stress have been largely unexplored, a handful of studies suggest children with specific genetic characteristics are most vulnerable to prenatal stress. We evaluated the brain-derived neurotrophic factor Val66Met gene (BDNF) as a moderator of the effect of prenatal IPV exposure on infant temperamental and cortisol regulation in response to a psychosocial challenge. Ninety-nine mother–infant dyads recruited from the community were assessed when infants (51% female) were 11 to 14 months. Maternal reports of IPV during pregnancy and infant temperament were obtained, and infant saliva was collected for genotyping and to assess cortisol reactivity (before and after the Strange Situation Task). Significant genetic moderation effects were found. Among infants with the BDNF Met allele, prenatal IPV predicted worse temperamental regulation and mobilization of the cortisol response, while controlling for infant postnatal exposure to IPV, other maternal traumatic experiences, and infant sex. However, prenatal IPV exposure was not associated with temperamental or cortisol outcomes among infant carriers of the Val/Val genotype. Findings are discussed in relation to prenatal programming and biological susceptibility to stress.

The Effects of Moderate Physical Exercise on Adult Cognition: A Systematic Review

Background: Physical exercise is a systematic sequence of movements executed with a predefined purpose. This muscular activity impacts not only on circulatory adaptations, but also neuronal integration with the potential to influence cognition. The aim of this review was to determine whether the literature supports the idea that physical exercise promotes cognitive benefits in healthy adults.

Methods: A systematic search for relevant articles was performed according to the Preferred Reporting Items for Systematic Review and Meta-Analysis criteria using available databases (PubMed, LILACS, Scopus, Web of Science, The Cochrane Library, OpenGrey, Google Scholar and CENTRAL). The search terms included “humans” or “adults” or “cognition” or “awareness” or “cognitive dissonance” or “cognitive reserve” or “comprehension” or “consciousness” and “motor activity” or “exercise” or “physical fitness,” and not “aged” or “nervous system diseases,” with the purpose of finding associations between moderate physical exercise and cognition. A methodological quality and risk of bias unit assessed the eligibility of articles.

Results: A total of 7179 articles were identified. Following review and quality assessment, three articles were identified to fulfill the inclusion criteria. An association between moderate physical exercise and cognition was observed. Improvements in cognitive parameters such as reduced simple reaction time, improved response precision and working memory were identified among the included articles.

Conclusion: This systematic review found that moderate physical exercise improves cognition.

Brain-derived neurotrophic factor (BDNF) in children with ASD and their parents: a 3-year follow-up

OBJECTIVE

Several lines of evidence point to a probable relationship between brain-derived neurotrophic factor (BDNF) and autism spectrum disorder (ASD), but studies have yielded inconsistent findings on the BDNF serum level in ASD. The study aimed to assess those levels in children with ASD and their families.

METHOD

BDNF serum levels were measured in 45 ASD children without intellectual disability (ID) and allergies, age 30-42 months and age-matched normal controls. BDNF serum levels in the parents of the ASD subjects were compared to normal controls. BDNF serum levels in the ASD subjects were followed up for 3 years and correlated with adaptive functioning changes.

RESULTS

BDNF serum levels were measured to be lower in children with ASD and independent of all the major baseline characteristics of the subjects. Having a child with ASD raises the BDNF levels in parents comparing to controls. Prospectively, no correlation between the change of BDNF variables in time and the change of the Vineland scores was found.

CONCLUSIONS

Our results contradict those from recent published meta-analyses with the age, the presence of ID and allergies being possible contributing factors. The parents' data indeed point to a role of BDNF in the pathophysiology of ASD.

Plasticity after pediatric cochlear implantation: Implication from changes in peripheral plasma level of BDNF and auditory nerve responses

INTRODUCTION

Sensory neural hearing loss could lead to some structural and physiological changes in the auditory pathways, such as alteration in the expression of neurotrophins. These factors, especially Brain-Derived Neurotrophic Factor (BDNF), play an important role in synaptic functions and experience-related plasticity. Restoring cochlear function after hearing loss is possible through cochlear implantation (CI). Evaluation of the blood concentration changes of neurotrophins as prerequisites of plasticity could help scientists to determine the prognosis of CI as in the candidacy procedure or enhancing prosthesis function by adding the exact needed amount of BDNF to the electrode array.

METHODS

Here we have studied the plasma BDNF concentration before CI surgery and 6 months after using CI device in 15 pediatric CI recipients and compared this level with changes of BDNF concentration in 10 children who were using hearing aid (H.A). In addition, we searched for a possible correlation between post-surgery plasma BDNF concentration and electrical compound action potential (ECAP) and comfort-level (C-level) thresholds.

RESULTS

Plasma BDNF concentration in children with CI increased significantly after CI surgery, while this difference in H.A group was not significant. Analysis of repeated measures of ECAP and C-level thresholds in CI group showed that there were some kinds of steadiness during follow- up sessions for ECAP thresholds in basal and E16 of middle electrodes, whereas C-level thresholds for all selected electrodes increased significantly up to six months follow-up. Interestingly, we did not find any significant correlation between post-surgery plasma BDNF concentration and ECAP or C-level threshold changes.

CONCLUSION

It is concluded that changes in C-level threshold and steady state of ECAP thresholds and significant changes in BDNF concentration could be regarded as an indicator of experienced-related plasticity after CI stimulation.

Systemic Inflammation during the First Postnatal Month and the Risk of Attention Deficit Hyperactivity Disorder Characteristics among 10 year-old Children Born Extremely Preterm

Although multiple sources link inflammation with attention difficulties, the only human study that evaluated the relationship between systemic inflammation and attention problems assessed attention at age 2 years. Parent and/or teacher completion of the Childhood Symptom Inventory-4 (CSI-4) provided information about characteristics that screen for attention deficit hyperactive disorder (ADHD) among 793 10-year-old children born before the 28th week of gestation who had an IQ ≥ 70. The concentrations of 27 proteins in blood spots obtained during the first postnatal month were measured. 151 children with ADHD behaviors were identified by parent report, while 128 children were identified by teacher report. Top-quartile concentrations of IL-6R, TNF-α, IL-8, VEGF, VEFG-R1, and VEGF-R2 on multiple days were associated with increased risk of ADHD symptoms as assessed by a teacher. Some of this increased risk was modulated by top-quartile concentrations of IL-6R, RANTES, EPO, NT-4, BDNF, bFGF, IGF-1, PIGF, Ang-1, and Ang-2. Systemic inflammation during the first postnatal month among children born extremely preterm appears to increase the risk of teacher-identified ADHD characteristics, and high concentrations of proteins with neurotrophic properties appear capable of modulating this increased risk.

Increased BDNF may not be associated with cognitive impairment in heroin-dependent patients

A growing number of evidence suggests that brain-derived neurotrophic factor (BDNF) plays an important part in modulating the activities on the basis of hippocampus neural plasticity, such as learning and memory. Heroin addiction has a series of cognitive impairments that may be associated with BDNF. In this study, we explored the association of BDNF with cognitive function in heroin-dependent patients.We enrolled 86 heroin-dependent patients and 238 normal control subjects and examined their cognition by the repeatable battery for the assessment of neuropsychological status (RBANS) and serum BDNF levels in 2 groups.BDNF levels were significantly higher in patients than controls (P < .001). Cognitive scores of the RBANS showed that attention and language index (P < .05) were significantly lower in heroin-dependent patients than control groups. Unfortunately, we found no positive association between BDNF and cognitive function in patients, except that BDNF was positively associated with visuospatial/constructional index in control groups.Our findings suggest that BDNF may not be involved in the pathophysiology of heroin dependence, but more studies about cognitive impairment in heroin addiction are needed.

Association between obesity-related biomarkers and cognitive and motor development in infants

BACKGROUND

This study aimed to verify the association between obesity-related biomarkers and cognitive and motor development in infants between 6 and 24 months of age.

METHODS

A cross-sectional study was conducted with 50 infants and plasma levels of leptin, adiponectin, resistin, soluble tumor necrosis factor receptors 1 and 2 (sTNFR1 and sTNFR2), chemokines, brain-derived neurotrophic factor (BDNF), serum cortisol and redox status were measured. The Bayley-III test was utilized to evaluate cognitive and motor development, and multiple linear stepwise regression models were performed to verify the association between selected biomarkers and cognitive and motor development.

RESULTS

A significant association was found among plasma leptin and sTNFR1 levels with cognitive composite scores, and these two independents variables together explained 37% of the variability of cognitive composite scores (p=0.001). Only plasma sTNFR1 levels were associated and explained 24% of the variability of motor composite scores (p=0.003).

CONCLUSIONS

Plasma levels of sTNFR1 were associated with the increase in cognitive and motor development scores in infants between 6 and 24 months of age through a mechanism not directly related to excess body weight. Moreover, increase in plasma levels of leptin reduced the cognitive development in this age range.