Association between Obesity and Circulating Brain-Derived Neurotrophic Factor (BDNF) Levels: Systematic Review of Literature and Meta-Analysis

Exploring the Effect of Acute and Regular Physical Exercise on Circulating Brain-Derived Neurotrophic Factor Levels in Individuals with Obesity: A Comprehensive Systematic Review and Meta-Analysis

Obesity is a major global health concern linked to cognitive impairment and neurological disorders. Circulating brain-derived neurotrophic factor (BDNF), a protein crucial for neuronal growth and survival, plays a vital role in brain function and plasticity. Notably, obese individuals tend to exhibit lower BDNF levels, potentially contributing to cognitive decline. Physical exercise offers health benefits, including improved circulating BDNF levels and cognitive function, but the specific impacts of acute versus regular exercise on circulating BDNF levels in obesity are unclear. Understanding this can guide interventions to enhance brain health and counter potential cognitive decline in obese individuals. Therefore, this study aimed to explore the impact of acute and regular physical exercise on circulating BDNF in individuals with obesity. The target population comprised individuals classified as overweight or obese, encompassing both acute and chronic protocols involving all training methods. A comprehensive search was conducted across computerized databases, including PubMed, Academic Search Complete, and Web of Science, in August 2022, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Initially, 98 studies were identified, from which 16 studies, comprising 23 trials, met the selection criteria. Substantial heterogeneity was observed for both acute (I2 = 80.4%) and long-term effects (I2 = 88.7%), but low risk of bias for the included studies. A single session of exercise increased circulating BDNF levels among obese patients compared to the control group (ES = 1.25, 95% CI = 0.19 to 2.30, p = 0.021). However, with extended periods of physical exercise, there was no significant increase in circulating BDNF levels when compared to the control group (ES = 0.49, 95% CI = -0.08 to 1.06, p = 0.089). These findings highlight the need to consider exercise duration and type when studying neurobiological responses in obesity and exercise research. The study's results have implications for exercise prescription in obesity management and highlight the need for tailored interventions to optimize neurotrophic responses. Future research should focus on elucidating the adaptive mechanisms and exploring novel strategies to enhance BDNF modulation through exercise in this population. However, further research is needed considering limitations such as the potential age-related confounding effects due to diverse participant ages, lack of sex-specific analyses, and insufficient exploration of how specific exercise parameters (e.g., duration, intensity, type) impact circulating BDNF.

Neuroinflammation and Schizophrenia: New Therapeutic Strategies through Psychobiotics, Nanotechnology, and Artificial Intelligence (AI)

The prevalence of schizophrenia, affecting approximately 1% of the global population, underscores the urgency for innovative therapeutic strategies. Recent insights into the role of neuroinflammation, the gut-brain axis, and the microbiota in schizophrenia pathogenesis have paved the way for the exploration of psychobiotics as a novel treatment avenue. These interventions, targeting the gut microbiome, offer a promising approach to ameliorating psychiatric symptoms. Furthermore, advancements in artificial intelligence and nanotechnology are set to revolutionize psychobiotic development and application, promising to enhance their production, precision, and effectiveness. This interdisciplinary approach heralds a new era in schizophrenia management, potentially transforming patient outcomes and offering a beacon of hope for those afflicted by this complex disorder.

Positive Effects of Adiponectin, BDNF, and GLP-1 on Cortical Neurons Counteracting Palmitic Acid Induced Neurotoxicity

The prevalence of metabolic syndrome caused by diets containing excessive fatty acids is increasing worldwide. Patients with metabolic syndrome exhibit abnormal lipid profiles, chronic inflammation, increased levels of saturated fatty acids, impaired insulin sensitivity, excessive fat accumulation, and neuropathological issues such as memory deficits. In particular, palmitic acid (PA) in saturated fatty acids aggravates inflammation, insulin resistance, impaired glucose tolerance, and synaptic failure. Recently, adiponectin, brain-derived neurotrophic factor (BDNF), and glucose-like peptide-1 (GLP-1) have been investigated to find therapeutic solutions for metabolic syndrome, with findings suggesting that they are involved in insulin sensitivity, enhanced lipid profiles, increased neuronal survival, and improved synaptic plasticity. We investigated the effects of adiponectin, BDNF, and GLP-1 on neurite outgrowth, length, and complexity in PA-treated primary cortical neurons using Sholl analysis. Our findings demonstrate the therapeutic potential of adiponectin, BDNF, and GLP-1 in enhancing synaptic plasticity within brains affected by metabolic imbalance. We underscore the need for additional research into the mechanisms by which adiponectin, BDNF, and GLP-1 influence neural complexity in brains with metabolic imbalances.

Effect of smoking on Brain-Derived Neurotrophic Factor (BDNF) blood levels: A systematic review and meta-analysis

BACKGROUND

Brain-Derived Neurotrophic Factor (BDNF) is a neurotrophin that plays a crucial role in neuronal survival and plasticity. Previous studies have suggested that smoking may influence BDNF levels, but the findings have been inconsistent.

METHODS

A comprehensive search of electronic databases was conducted to identify relevant studies. Inclusion criteria were applied to select studies that investigated the relationship between smoking and blood levels of BDNF. A random-effects model was used to estimate the overall effect size.

RESULTS

A total of 23 studies were included. The meta-analysis revealed a significant association between smoking and increased blood levels of BDNF (standardized mean difference [SMD] = -0.38, 95 % confidence interval [CI] 0.15 to 0.62, p = 0.002). Subgroup analyses based on BDNF source showed a significant increase in plasma-derived BDNF levels (SMD = 1.02, 95 % CI 0.50 to 1.53, p = 0.0001), while no significant difference was observed in serum-derived BDNF levels (SMD = 0.02, 95 % CI -0.19 to 0.22, p = 0.87). The pooled analysis revealed a non-significant difference in blood levels of BDNF between former smokers and non-smokers (random-effects model, SMD = 0.21, 95 % CI -0.04 to 0.46, p = 0.1).

CONCLUSION

Smokers exhibited significantly higher plasma levels of BDNF compared to non-smokers. Further research is needed to elucidate the underlying mechanisms and explore the potential therapeutic implications of targeting BDNF in smoking.

Overweight during development dysregulates cellular metabolism and critical genes that control food intake in the prefrontal cortex

BACKGROUNDS AND AIMS

Childhood obesity is increasing substantially across the world. The World Obesity Federation (WOF) and World Health Organization (WHO) predicted that in 2030 > 1 billion people will be obese, and by 2035 over 4 billion will reach obesity worldwide. According to WHO, the world soon cannot afford the economic cost of obesity, and we need to act to stop obesity acceleration now. Data in the literature supports that the first 1000 days of life are essential in preventing obesity and related adversities. Therefore, using basic research, the present a study that focuses on the immediate effect of overnutrition and serotonin modulation during the lactation period.

METHODS

Using a neonatal overfeeding model, male Wistar rats were divided into four groups based on nutrition or serotonin modulation by pharmacological treatment up to 22 days of life. Cellular and mitochondrial function markers, oxidative stress biomarkers and mRNA levels of hedonic and homeostatic genes were evaluated.

RESULTS

Our data showed that overfeeding during lactation decrease NAD/NADH ratio, citrate synthase activity, and increase ROS production. Lipid and protein oxidation were increased in overfed animals, with a decrease in antioxidant defenses, we also observe a differential expression of mRNA levels of homeostatic and hedonic genes. On the contrary, serotonin modulation with selective serotonin reuptake inhibitors treatment reduces harmful effects caused by overnutrition.

CONCLUSION

Early effects of overnutrition significantly affect the prefrontal cortex at molecular and cellular level, which could mediate obesity-related neurodegenerative dysfunction.

E-Cigarette Exposure Alters Neuroinflammation Gene and Protein Expression in a Murine Model: Insights from Perinatally Exposed Offspring and Post-Birth Mothers

The use of E-cigarettes, often considered a safer alternative to traditional smoking, has been associated with high rates of cellular toxicity, genetic alterations, and inflammation. Neuroinflammatory impacts of cigarette smoking during pregnancy have been associated with increased risks of adverse childhood health outcomes; however, it is still relatively unknown if the same propensity is conferred on offspring by maternal vaping during gestation. Results from our previous mouse inhalation studies suggest such a connection. In this earlier study, pregnant C57BL/6 mice were exposed daily to inhaled E-cig aerosols (i.e., propylene glycol and vegetable glycerin, [PG/VG]), with or without nicotine (16 mg/mL) by whole-body inhalation throughout gestation (3 h/d; 5 d/week; total ~3-week) and continuing postnatally from post-natal day (PND) 4-21. As neuroinflammation is involved in the dysregulation of glucose homeostasis and weight gain, this study aimed to explore genes associated with these pathways in 1-mo.-old offspring (equivalent in humans to 12-18 years of age). Results in the offspring demonstrated a significant increase in glucose metabolism protein levels in both treatment groups compared to filtered air controls. Gene expression analysis in the hypothalamus of 1 mo. old offspring exposed perinatally to E-cig aerosols, with and without nicotine, revealed significantly increased gene expression changes in multiple genes associated with neuroinflammation. In a second proof-of-principal parallel study employing the same experimental design, we shifted our focus to the hippocampus of the postpartum mothers. We targeted the mRNA levels of several neurotrophic factors (NTFs) indicative of neuroinflammation. While there were suggestive changes in mRNA expression in this study, levels failed to reach statistical significance. These studies highlight the need for ongoing research on E-cig-induced alterations in neuroinflammatory pathways.

Long-Term Brain Structure and Cognition Following Bariatric Surgery

Importance

Weight loss induced by bariatric surgery (BS) is associated with improved cognition and changed brain structure; however, previous studies on the association have used small cohorts and short follow-up periods, making it difficult to determine long-term neurological outcomes associated with BS.

Objective

To investigate long-term associations of weight loss after BS with cognition and brain structure and perfusion.

Design, Setting, and Participants

This cohort study included participants from the Bariatric Surgery Rijnstate and Radboudumc Neuroimaging and Cognition in Obesity study. Data from participants with severe obesity (body mass index [BMI; calculated as weight in kilograms divided by height in meters squared] >40, or BMI >35 with comorbidities) eligible for Roux-en-Y gastric bypass and aged 35 to 55 years were enrolled from a hospital specialized in BS (Rijnstate Hospital, Arnhem, the Netherlands). Participants were recruited between September 2018 and December 2020 with follow-up till March 2023. Data were collected before BS and at 6 and 24 months after BS. Data were analyzed from March to November 2023.

Exposure

Roux-en-Y gastric bypass.

Main Outcomes and Measures

Primary outcomes included body weight, BMI, waist circumference, blood pressure, medication use, cognitive performance (20% change index of compound z-score), brain volumes, cortical thickness, cerebral blood flow (CBF), and spatial coefficient of variation (sCOV). Secondary outcomes include cytokines, adipokines, depressive symptoms (assessed using the Beck Depression Inventory), and physical activity (assessed using the Baecke Questionnaire).

Results

A total of 133 participants (mean [SD] age, 46.8 [5.7] years; 112 [84.2%] female) were included. Global cognition was at least 20% higher in 52 participants (42.9%) at 24 months after BS. Compared with baseline, at 24 months, inflammatory markers were lower (mean [SD] high-sensitivity C-reactive protein: 4.77 [5.80] μg/mL vs 0.80 [1.09] μg/mL; P < .001), fewer patients used antihypertensives (48 patients [36.1%] vs 22 patients [16.7%]), and patients had lower depressive symptoms (median [IQR] BDI score: 9.0 [5.0-13.0] vs 3.0 [1.0-6.0]; P < .001) and greater physical activity (mean [SD] Baecke score: 7.64 [1.29] vs 8.19 [1.35]; P < .001). After BS, brain structure and perfusion were lower in most brain regions, while hippocampal and white matter volume remained stable. CBF and sCOV did not change in nucleus accumbens and parietal cortex. The temporal cortex showed a greater thickness (mean [SD] thickness: 2.724 [0.101] mm vs 2.761 [0.007] mm; P = .007) and lower sCOV (median [IQR] sCOV: 4.41% [3.83%-5.18%] vs 3.97% [3.71%-4.59%]; P = .02) after BS.

Conclusions and Relevance

These findings suggest that BS was associated with health benefits 2 years after surgery. BS was associated with improved cognition and general health and changed blood vessel efficiency and cortical thickness of the temporal cortex. These results may improve treatment options for patients with obesity and dementia.

New insights into the interaction between polycystic ovary syndrome and psychiatric disorders: A narrative review

Polycystic ovary syndrome (PCOS) is a prevalent endocrine disease characterized by hyperandrogenism, ovulatory dysfunction, and ovarian polycystic changes, which combines with reproductive problems, metabolic disorders, and psychological disorders to exhibit a far-reaching impact on the physical and mental health of women. We reviewed previous research and discovered that psychiatric disorders are more common in PCOS patients and their children, potentially exacerbating the condition and creating a vicious loop. To understand the reasons, relevant articles were collected following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines from PubMed, Web of Science, and Cochrane Library, through December 2022. Evidence suggested that PCOS-related clinical manifestations, hyperandrogenism, insulin resistance, obesity, gut dysbiosis, and other variables may increase the risk of psychiatric disorders in patients. In turn, psychiatric disorders may aggravate the pathologic process of PCOS and increase the difficulty of the treatment. We systematically reported the mechanisms underlying the psychiatric disorders-PCOS interactions, intending to provide potential ways to break the vicious cycle and lay the groundwork for future research. However, research on PCOS and psychiatric disorders were still in initial stages, which limited the scope of this review. More studies are needed to further verify our findings.

Solanum melongena extract supplementation protected skeletal muscle and brain damage by regulation of BDNF/PGC1α/irisin pathway via brain function-related myokines in high-fat diet induced obese mice

In this study, we investigated the protective effects of SM on skeletal muscle and brain damage by regulation of BDNF/PGC1α/irisin pathway via brain function related myokines in high-fat diet-induced OB mice. OB was induced by high-fat diet for 6 weeks. SM extract (SME) was administered with 200 mg/kg BW (LSM) and 500 mg/kg BW (HSM) by oral gavage every day for 12 weeks. Behavior tests such as grip strength, Y-maze, and passive avoidance test were conducted to analyze muscle and cognitive function. Histopathological changes in skeletal muscle and brain were examined by hematoxylin and eosin staining and the protein levels of biomarkers related to oxidative stress, inflammation, protein degradation, neuro-plasticity, and cell cycling were measured by western blot. SME regulated morphological changes (muscle cross-sectional area: 1.23%, 1.40%; density of neurons in hippocampus:1.74%, 1.73%) in T2DM mice. Importantly, SME supplementation significantly increased several muscle-derived myokines which might influence the expression of neuronal markers in OB mice (FGF21: 1.27%, 1.34%; PGC1α: 1.0%, 1.32%; IRISIN: 1.9%, 1.08%; BDNF: 1.35%, 1.23%). Accordingly, SME activated hippocampal neurotrophic factors including BDNF (1.0%, 1.2%) and its associated PGC1α/irisin pathway (PGC1α :1.1%, 1.1%; IRISIN:1.1%, 0.9%) significantly. This study demonstrated the possibliy that protective myokines increased by SME supplementation may contribute to neuro-protection in OB mice. Taken together, the current study suggests that SME can be used to prevent skeletal muscle and brain damage in OB by protecting against oxidative stress and inflammatin via modulation of the BDNF/PGC1α/irisin pathway in the therapeutic approach of obese patients.

A comprehensive review of genetic causes of obesity

BACKGROUND

Obesity is a multifactorial chronic disease with a high, increasing worldwide prevalence. Genetic causes account for 7% of the cases in children with extreme obesity.

DATA SOURCES

This narrative review was conducted by searching for papers published in the PubMed/MEDLINE, Embase and SciELO databases and included 161 articles. The search used the following search terms: "obesity", "obesity and genetics", "leptin", "Prader-Willi syndrome", and "melanocortins". The types of studies included were systematic reviews, clinical trials, prospective cohort studies, cross-sectional and prospective studies, narrative reviews, and case reports.

RESULTS

The leptin-melanocortin pathway is primarily responsible for the regulation of appetite and body weight. However, several important aspects of the pathophysiology of obesity remain unknown. Genetic causes of obesity can be grouped into syndromic, monogenic, and polygenic causes and should be assessed in children with extreme obesity before the age of 5 years, hyperphagia, or a family history of extreme obesity. A microarray study, an analysis of the melanocortin type 4 receptor gene mutations and leptin levels should be performed for this purpose. There are three therapeutic levels: lifestyle modifications, pharmacological treatment, and bariatric surgery.

CONCLUSIONS

Genetic study technologies are in constant development; however, we are still far from having a personalized approach to genetic causes of obesity. A significant proportion of the affected individuals are associated with genetic causes; however, there are still barriers to its approach, as it continues to be underdiagnosed. Video Abstract (MP4 1041807 KB).

Plasma irisin and the brain-derived neurotrophic factor levels in sedentary subjects: effect of 8-weeks lifestyle intervention

Objectives. Sedentary lifestyle increasingly observed in the population contributes to the incremental incidence of obesity, cardiovascular diseases, mental disorders, type 2 diabetes, hyper-tension, dyslipidemia, and others. Physical inactivity together with an imbalance in caloric intake and expenditure leads to a loss of muscle mass, reduced insulin sensitivity, and accumulation of the visceral fat. Organokines (adipokines, myokines, hepatokines, etc.) serve in the organism for inter-organ communication. However, human studies focused on the exercise-related changes in plasma levels of certain myokines have produced contradictory results. In the present study, we verified a hypothesis that myokine irisin, which is expected to increase in response to physical activity, induces brain-derived neurotrophic factor (BDNF) production and by this way mediates the beneficial effect of exercise on several brain functions. Subjects and Methods. Women (n=27) and men (n=10) aged 44.5±12.0 years, who were sedentary and overweight/obese (men ≥25%, women ≥28% body fat), participated in the study. The effect of an 8-week intensive lifestyle intervention (150 minutes of moderate physical activity per week, diet modification, and reduction of caloric intake) on the selected organokines (irisin, BDNF) in the context of an expected improvement in cardiometabolic status was examined. Results. The 8-week lifestyle intervention resulted in a significant (p<0.05) reduction in body mass index, body fat, blood pressure, insulin resistance, lipid and liver parameters, and irisin levels (p<0.001). However, BDNF increase in the whole group did not reach statistical significance. After the improvement of cardiometabolic parameters, a significant decrease in irisin and increase in BDNF levels were also observed in the subgroup with unsatisfactory (≤5%) body weight reduction. Neither relationship between irisin and BDNF levels, nor effect of age or sex on their levels was observed. Conclusions. We cannot confirm the hypothesis that exercise-induced irisin may increase the BDNF levels, whereas, the organokine levels in the periphery may not completely reflect the processes in the brain compartments. The observed decrease in irisin levels after 8-week intensive lifestyle intervention program, which was in contrary to its supposed mechanisms of action and dynamics, suggests the presence of several yet undiscovered impacts on the secretion of irisin.

Diet in relation to Metabolic, sleep and psychological health Status (DiMetS): protocol for a cross-sectional study

INTRODUCTION

Metabolic disturbances are of major health concerns in the world. In addition to their high prevalence, these disorders have substantial roles in developing other physical and mental diseases. Diet could have a considerable influence on managing the progression of these conditions and their consequent health-related effects. The aim of the 'Diet in relation to Metabolic, sleep and psychological health Status' Project is to explore the association of nutrition with metabolic, sleep and mental health, considering potential mediators including brain-derived neurotrophic factor (BDNF) and adropin.

METHODS AND ANALYSIS

This cross-sectional study will be conducted on adults (20-65 years) working in schools of Isfahan, Iran. A multistage cluster random sampling method will be used to select participants. Anthropometric, body composition and biochemical values including fasting blood glucose, lipid profile, 25-hydroxy vitamin D, insulin, BDNF, adropin, malondialdehyde, superoxide dismutase, glutathione peroxidase, uric acid, creatinine and C reactive protein will be measured for each participant. National Cholesterol Education Program and Adult Treatment Panel III will be considered to define metabolic syndrome. Diet will be assessed through a validated Food Frequency Questionnaire. Furthermore, sleep status, mental health, quality of life, physical activity and demographic status of individuals will be assessed by validated questionnaires. The collected data will be analysed using appropriate statistical methods.

ETHICS AND DISSEMINATION

The study protocol was approved by the local Ethics Committee of Isfahan University of Medical Sciences. All participants will provide written informed consent. Dissemination will be through conference presentations and publications in peer-reviewed journals.

Association between salivary mature brain-derived neurotrophic factor and psychological distress in healthcare workers

INTRODUCTION

Previous studies have suggested association between brain-derived neurotrophic factor (BDNF) and the stress level of workers. However, no studies have investigated the potential of salivary mature BDNF (mBDNF) level as a noninvasive biomarker for psychological distress. This study aimed to explore the reliability of salivary mBDNF as a biomarker for psychological distress in healthcare workers. Furthermore, we examined the relationship between salivary and plasma mBDNF levels and their correlation with age, sex, body mass index (BMI), and exercise habits.

METHODS

Fifty-one healthy healthcare workers (26 men) from the University of Occupational and Environmental Health, Japan, participated in this study. In this cross-sectional study, participants provided demographic information. Psychological distress was assessed using the Kessler 6 (K6). Saliva and blood samples were collected, and mBDNF was measured by ELISA. Spearman's rank correlation coefficient was performed to analyze the relationship between mBDNF (saliva and plasma) and K6. Statistical analyses were conducted using Stata 17.0, and a significance level of p < .05 was applied.

RESULTS

The median K6 score was 1 (interquartile range [IQR]: 0-3). The median (IQR) salivary mBDNF was 1.36 (1.12-1.96) pg/mL, whereas the mean (standard deviation) plasma mBDNF was 1261.11 (242.98) pg/mL. No correlation was observed between salivary and plasma mBDNF concentrations or with the K6 score. Additionally, there were no associations between salivary or plasma mBDNF concentrations and age, sex, or exercise habits. Finally, an association between plasma mBDNF concentration and BMI was found only in univariate analysis.

CONCLUSION

Our findings indicate that salivary mBDNF can be accurately measured noninvasively in healthcare workers. Within our study sample, salivary mBDNF did not demonstrate any correlation with K6 and plasma mBDNF. Future studies with a larger study sample and a diverse study population consisting of healthy participants and patients with psychiatric disorders are warranted.

The Role of Adipokines and Myokines in the Pathogenesis of Different Obesity Phenotypes-New Perspectives

Obesity is a characteristic disease of the twenty-first century that is affecting an increasing percentage of society. Obesity expresses itself in different phenotypes: normal-weight obesity (NWO), metabolically obese normal-weight (MONW), metabolically healthy obesity (MHO), and metabolically unhealthy obesity (MUO). A range of pathophysiological mechanisms underlie the occurrence of obesity, including inflammation, oxidative stress, adipokine secretion, and other processes related to the pathophysiology of adipose tissue (AT). Body mass index (BMI) is the key indicator in the diagnosis of obesity; however, in the case of the NWO and MONW phenotypes, the metabolic disturbances are present despite BMI being within the normal range. On the other hand, MHO subjects with elevated BMI values do not present metabolic abnormalities. The MUO phenotype involves both a high BMI value and an abnormal metabolic profile. In this regard, attention has been focused on the variety of molecules produced by AT and their role in the development of obesity. Nesfatin-1, neuregulin 4, myonectin, irisin, and brain-derived neurotrophic factor (BDNF) all seem to have protective effects against obesity. The primary mechanism underlying the action of nesfatin-1 involves an increase in insulin sensitivity and reduced food intake. Neuregulin 4 sup-presses lipogenesis, decreases lipid accumulation, and reduces chronic low-grade inflammation. Myonectin lowers the amount of fatty acids in the bloodstream by increasing their absorption in the liver and AT. Irisin stimulates the browning of white adipose tissue (WAT) and consequently in-creases energy expenditure, additionally regulating glucose metabolism. Another molecule, BDNF, has anorexigenic effects. Decorin protects against the development of hyperglycemia, but may also contribute to proinflammatory processes. Similar effects are shown in the case of visfatin and chemerin, which may predispose to obesity. Visfatin increases adipogenesis, causes cholesterol accumulation in macrophages, and contributes to the development of glucose intolerance. Chemerin induces angiogenesis, which promotes the expansion of AT. This review aims to discuss the role of adipokines and myokines in the pathogenesis of the different obesity phenotypes.

Study on Potential Differentially Expressed Genes in Idiopathic Pulmonary Fibrosis by Bioinformatics and Next-Generation Sequencing Data Analysis

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive lung disease with reduced quality of life and earlier mortality, but its pathogenesis and key genes are still unclear. In this investigation, bioinformatics was used to deeply analyze the pathogenesis of IPF and related key genes, so as to investigate the potential molecular pathogenesis of IPF and provide guidance for clinical treatment. Next-generation sequencing dataset GSE213001 was obtained from Gene Expression Omnibus (GEO), and the differentially expressed genes (DEGs) were identified between IPF and normal control group. The DEGs between IPF and normal control group were screened with the DESeq2 package of R language. The Gene Ontology (GO) and REACTOME pathway enrichment analyses of the DEGs were performed. Using the g:Profiler, the function and pathway enrichment analyses of DEGs were performed. Then, a protein-protein interaction (PPI) network was constructed via the Integrated Interactions Database (IID) database. Cytoscape with Network Analyzer was used to identify the hub genes. miRNet and NetworkAnalyst databaseswereused to construct the targeted microRNAs (miRNAs), transcription factors (TFs), and small drug molecules. Finally, receiver operating characteristic (ROC) curve analysis was used to validate the hub genes. A total of 958 DEGs were screened out in this study, including 479 up regulated genes and 479 down regulated genes. Most of the DEGs were significantly enriched in response to stimulus, GPCR ligand binding, microtubule-based process, and defective GALNT3 causes HFTC. In combination with the results of the PPI network, miRNA-hub gene regulatory network and TF-hub gene regulatory network, hub genes including LRRK2, BMI1, EBP, MNDA, KBTBD7, KRT15, OTX1, TEKT4, SPAG8, and EFHC2 were selected. Cyclothiazide and rotigotinethe are predicted small drug molecules for IPF treatment. Our findings will contribute to identification of potential biomarkers and novel strategies for the treatment of IPF, and provide a novel strategy for clinical therapy.

Brain-derived neurotrophic factor levels in perinatal depression: A systematic review and meta-analysis

BACKGROUND

This systematic review and meta-analysis aim to synthesize the available evidence and determine the overall brain-derived neurotrophic factor (BDNF) levels in individuals diagnosed with perinatal depression (PND).

METHODS

We performed a thorough search of electronic databases, including PubMed, Embase, PsycINFO, and Web of Science, from their start until April 30, 2023. Our search strategy involved using specific keywords and medical subject headings (MeSH) terms related to BDNF, perinatal, post-partum, and antepartum depression. In the meta-analysis, we employed a random-effects model, and subgroup analyses were conducted to investigate any variations in the results.

RESULTS

A total of 15 studies met the inclusion criteria, of which 10 were used in the quantitative analysis. The meta-analysis demonstrated a significant decrease in BDNF levels in both individuals with antepartum depression (SMD: -0.31; 95% CI: -0.48 to -0.13; p-value = 0.0008; I2  = 71%), and post-partum depression (SMD: -0.61; 95% CI: -0.99 to -0.22; p-value = 0.0002 I2  = 77%). Furthermore, a significantly higher rate of PND among individuals in the lowest BDNF quartile (OR: 2.64; 95% CI: 1.01 to 6.89; p-value = 0.05; I2  = 90%) was seen. The results of subgroup analyses showed a statistically significant effect of the depression assessment tool on overall heterogeneity between studies.

CONCLUSION

This systematic review and meta-analysis provide evidence of lower BDNF protein levels in individuals diagnosed with PND. The results indicate that BDNF dysregulation may play a part in the development of PND. More research is needed to understand the mechanisms behind this and explore potential therapeutic applications.

Gene-exercise interaction on brain health in children with overweight/obesity: the ActiveBrains randomized controlled trial

We investigated the interaction between a genetic score and an exercise intervention on brain health in children with overweight/obesity. One hundred one children with overweight/obesity (10.0 ± 1.5 yr, 59% girls) were randomized into a 20-wk combined exercise intervention or a control group. Several cognitive and academic outcomes were measured with validated tests. Hippocampal volume was quantified using magnetic resonance imaging. Six brain health-related polymorphisms [rs6265 (BDNF), rs2253206 (CREB1), rs2289656 (NTRK2), rs4680 (COMT), rs429358, and rs7412 (APOE)] were genotyped. Cognitive flexibility and academic skills improved significantly more in the exercise than in the control group only in the children with a "favorable" genetic profile [mean z-score, 0.41-0.67 (95% CI 0.11 to 1.18)], yet not in those with "less favorable" genetic profile. An individual response analysis showed that children responded to exercise in cognitive flexibility only in the "genetically favorable" group [i.e., 62% of them had a meaningful (≥0.2 Cohen d) increase in the exercise group compared with only 25% in the control group]. This finding was consistent in per-protocol and intention-to-treat analyses (P = 0.01 and P = 0.03, respectively). The results were not significant or not consistent for the rest of outcomes studied. Our findings suggest that having a more favorable genetic profile makes children with overweight/obesity more responsive to exercise, particularly for cognitive flexibility.NEW & NOTEWORTHY Interindividual differences have been reported in brain health-related outcomes in response to exercise interventions in adults, which could be partially explained by genetic background differences. However, the role of genetic polymorphisms on brain health-related outcomes in response to exercise interventions remains unexplored in pediatric population. The current study in children with overweight/obesity showed that a genetic score composed of six brain health-related polymorphisms (BDNF, CREB1, NTRK2, COMT, and APOE) regulated the exercise-induced response on several brain health outcomes, yet mainly and more consistently on cognitive flexibility.

Alteration of BDNF, SPARC, FGF-21, and GDF-15 circulating levels after 1 year of anti-obesity treatments and their association with 1-year weight loss

PURPOSE

Emerging evidence revealed that brain-derived neurotrophic factor (BDNF), secreted protein acidic and rich in cysteine (SPARC), fibroblast growth factor 21(FGF-21) and growth differentiation factor 15 (GDF-15) are involved in energy metabolism and body weight regulation. Our study aimed at examining their association with BMI, their alterations after anti-obesity treatments, and their association with 1-year weight loss.

METHODS

A prospective observational study of 171 participants with overweight and obesity and 46 lean controls was established. All participants received lifestyle educational intervention (LEI) with or without anti-obesity treatments (LEI + bariatric/metabolic surgery, n = 41; LEI + topiramate, n = 46; LEI + liraglutide, n = 31; LEI + orlistat, n = 12; and LEI alone, n = 41). Anthropometric and metabolic parameters, insulin sensitivity, C-reactive protein (CRP), fasting plasma levels of BDNF, SPARC, GDF-15, and FGF-21 were measured at baseline and 1 year.

RESULTS

Multiple linear regression showed that fasting levels of SPARC, FGF-21, and GDF-15 were significantly associated with baseline BMI after adjustment for age and sex. At 1 year, the average weight loss was 4.8% in the entire cohort with a significant improvement in glycemia, insulin sensitivity, and CRP. Multiple linear regression adjusted for age, sex, baseline BMI, type of treatment, and presence of T2DM revealed that the decrease in log10FGF-21 and log10GDF-15 at 1 year from baseline was significantly associated with a greater percentage of weight loss at 1 year.

CONCLUSIONS

This study highlights the association of SPARC, FGF-21, and GDF-15 levels with BMI. Decreased circulating levels of GDF-15 and FGF-21 were associated with greater weight loss at 1 year, regardless of the types of anti-obesity modalities.

Serum concentrations of BDNF in adolescents with metabolic syndrome: a case-control study between normal - BMI adolescents and adolescents with obesity

Brain-Derived Neurotrophic Factor (BDNF) has been linked to various conditions of the cardiovascular and nervous systems. Scarce data exist about the concentrations of BDNF in children and adolescents in relation with obesity and metabolic syndrome (MetS). The aim of this study was to examine the serum BDNF concentrations in adolescents with metabolic syndrome and according to their body mass index (BMI) status. This was a case-control study, assessing BDNF concentrations between adolescents with MetS (with obesity vs. normal-BMI), in relation to sex, anthropometric, metabolic and endocrine parameters. Participants included male and female adolescents, whose anthropometric and metabolic panel, as well as serum BDNF concentrations were measured. A total of 59 adolescents (obesity: 29; normal-BMI: 30) were included in the study. Increased serum BDNF concentrations were observed in MetS adolescents with obesity when compared with normal-BMI adolescents (p < 0.001). Males exhibited higher concentrations of BDNF than females (p = 0.045). The sample was further divided into four categories by sex and BMI status, with normal-BMI females exhibiting significantly lower BDNF concentrations than females and males with obesity(p = 0.005). In the entire study sample, serum BDNF concentrations correlated positively with BMI z-scores, however, this statistical significance was preserved only in the females of the sample. No statistical difference was observed between males of different BMI z-scores categories.  Conclusion: Obesity appeared as a major factor for increased serum BDNF concentrations in adolescents with MetS (vs. normal-BMI), with a higher impact on BDNF concentrations in females than males. What is Known: • The brain-derived neurotrophic factor (BDNF) is involved in metabolic syndrome in adults but data in adolescents are scarce. What is New: • Obesity (vs. normal BMI) was a major factor for increased serum BDNF in adolescents with metabolic syndrome. • Obesity had a higher impact on BDNF concentrations in females than males with metabolic syndrome.

Association between Mediterranean dietary pattern with sleep duration, sleep quality and brain derived neurotrophic factor (BDNF) in Iranian adults

Data on the association between Mediterranean diet, sleep and brain-derived neurotrophic factor (BDNF) were limited in Middle Eastern populations. We examined the association between Mediterranean dietary pattern with sleep quality/quantity, and serum BDNF in Iranian adults. This cross-sectional study was performed among 535 middle-aged adults (54% men), selected by multistage cluster random sampling method. The Pittsburgh sleep quality index and a validated food frequency questionnaire were used to assess sleep quality, sleep quantity, and Mediterranean diet score (MDS). Twelve-hour fasting blood samples were taken to evaluate serum BDNF values. Participants in the highest tertile of MDS, in comparison to those in the lowest tertile, had lower odds of having short sleep (OR = 0.44, 95%CI: 0.21-0.91) and poor sleep quality (OR = 0.48, 95%CI: 0.22-0.96), after adjustment for potential confounders. Among specific domains of sleep quality, lower odds of subjective sleep quality, sleep latency, and daytime dysfunction were associated with increased MDS. Higher adherence to MDS among individuals with overweight or obesity reduced the odds of having short sleep; this relation was not seen among individuals with normal weight. In contrast, the association between sleep quality and the MDS was significant in individuals with normal weight, but not those with overweight or obesity. Participants with higher adherence to MDS had lower odds for low BDNF values; however, this relation was not statistically significant. Overall, Iranian adults with a higher adherence to MDS had considerably lower odds of having short sleep and poor sleep quality. BDNF would not be an intermediate molecule for this connection.

A primary study on rat fetal development and brain-derived neurotrophic factor levels under the control of electromagnetic fields

Background

In previous researches, electromagnetic fields have been shown to adversely affect the behavior and biology of humans and animals; however, body growth and brain-derived neurotrophic factor levels were not evaluated.

Objective

The original investigation aimed to examine whether Electromagnetic Fields (EMF) exposure had adverse effects on spatial learning and motor function in rats and if physical activity could diminish the damaging effects of EMF exposure. In this study, we measured anthropometric measurements and brain-derived neurotrophic factor (BDNF) levels in pregnant rats' offspring to determine if Wi-Fi EMF also affected their growth. These data we report for the first time in this publication.

Methods

Twenty Albino-Wistar pregnant rats were divided randomly into EMF and control (CON) groups, and after delivery, 12 male fetuses were randomly selected. For assessing the body growth change of offspring beginning at delivery, then at 21 postnatal days, and finally at 56 post-natal days, the crown-rump length of the body was assessed using a digital caliper. Examining BDNF factor levels, an Enzyme-linked immunosorbent assay ELISA kit was taken. Bodyweight was recorded by digital scale.

Results

Outcomes of the anthropometric measurements demonstrated that EMF blocked body growth in rats exposed to EMF. The results of the BDNF test illustrated that the BDNF in the EMF liter group was remarkably decreased compared to the CON group. The results indicate that EMF exposure could affect BDNF levels and harm body growth in pregnant rats' offspring.

Conclusions

The results suggest that EMF exposure could affect BDNF levels and impair body growth in pregnant rats' offspring.

Acute effect of moderate and high-intensity interval exercises on asprosin and BDNF levels in inactive normal weight and obese individuals

This study aimed to examine the acute effects of moderate-intensity aerobic and high-intensity interval exercise protocols on Asprosin and Brain-Derived Neurotrophic Factor (BDNF) levels in inactive normal weight and obese individuals. A total of 20 male individuals aged 18-65 years, ten normal weight (NW) (Body Mass Index (BMI): 18.5-24.99 kg/m²) and 10 obese (Ob) (BMI: 24.99-35.00 kg/m²) participated in this study, voluntarily. Moderate aerobic exercise (AE) (main circuit 30 min, between 40 and 59% of Heart Rate Reserve: HRR) and High-Intensity Interval exercise (HIIE) running protocols (main circuit 20 min, between 75 and 90% of the HRR for 1 min*10 times, and 1-min active rest at 30% of the HRR) was applied to the volunteer participants in the morning hours (08.00-10.00 a.m.), following the night fasting (at least 8-10 h) for at least 3 days between each other. Blood samples were collected from the participants before and immediately after each exercise protocol, and serum asprosin and BDNF hormone levels were determined by Enzyme-Linked Immunosorbent Assay" method. Basal serum asprosin was found to be significantly higher in the Ob group compared to the NW group (p < .001), while the basal serum BDNF hormone was found to be lower (p < 0.05). It was observed that the serum asprosin level of both groups decreased significantly after both AE and HIIE protocols (p < 0.05). In addition, there was a significantly higher decrease in serum asprosin level in the Ob group compared to the NW group after HIIE protocol. For the Ob group, serum BDNF level increased considerably after HIIE protocol compared to AE protocol (p < 0.05). Serum asprosin was found to be higher in the Ob group, while the serum BDNF was found to be lower. In addition, the acute exercises of different intensity significantly affected hormones that regulate appetite metabolism. In particular, it was observed that the HIIE protocol had a greater effect on the regulation of appetite (hunger-satiety) in the Ob group. This result can be taken into account when planning training programs for these individuals.

Effect of a Reduced-Calorie Diet on Plasma Levels of Inflammatory and Metabolic Factors in Overweight/Obese Patients with Cardiovascular Risk Factors

Background

Calorie restriction without malnutrition is likely to improve cardiovascular risk factors.

Objectives

The aim of this study was to investigate calorie restriction on markers of cardiometabolic risk in overweight/obese adults with cardiovascular risk factors.

Methods

In a parallel controlled trial, patients with overweight or obesity and one or more cardiovascular risk factor were randomized to a modest reduced-calorie diet (75% of the total calculated energy requirements) or control (no calorie restriction) groups and followed up for two months. Body weight, dietary intake, fasting plasma levels of C-reactive protein (CRP), monocyte chemoattractant protein-1 (MCP-1), intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), brain-derived neurotrophic factor (BDNF), neuropeptide Y (NPY), lipids, and glycemic factors were measured at baseline, and after two months. The differences were analyzed with analysis of covariance (ANCOVA).

Results

Sixty-six participants (33 in each group) completed the study. Body weight changed in the reduced-calorie diet group (- 3.05 ± 2.65 kg), and blood pressure was improved (systolic -6.96 ± 12.04 and diastolic - 3.90 ± 8.97 mmHg). The reduced-calorie diet improved plasma ICAM-1 (change from baseline - 0.45 ± 1.99 ng/mL, P = 0.033, ANCOVA), MCP-1 (change from baseline - 0.50 pg/mL, P = 0.011, ANCOVA), low-density lipoprotein cholesterol (change from baseline - 9.35 ± 19.61 mg/dL, P < 0.001, ANCOVA), and triglyceride (change from baseline -33.66 ± 49.08, P = 0.001, ANCOVA), but BDNF, NPY, and other cardiometabolic factors were not different.

Conclusions

In overweight/obese subjects with cardiovascular risk factors which have been under medical treatment with risk-reducing medications, a modest weight loss induced by a reduced-calorie diet improved lipid profile, blood pressure, and reduced ICAM-1 and MCP-1 levels but had no effect on plasma BDNF or glycemic factors.

Association of BDNF gene missense polymorphism rs6265 (Val66Met) with three quantitative traits, namely, intelligence quotient, body mass index, and blood pressure: A genetic association analysis from North India

Background

Brain-derived neurotrophic factor (BDNF), a neurotransmitter modulator, plays a significant role in neuronal survival and growth and participates in neuronal plasticity, thus being essential for learning, memory, and the development of cognition. Additionally, it is crucial for appetite, weight, and metabolic control and plays a pivotal role in the cardiovascular system. The Val66Met polymorphism (rs6265) of the BDNF gene causes a decrease in BDNF secretion and plays a role in impairments in cognition, energy homeostasis, and cardiovascular events. The present study aimed to evaluate the association of polymorphism (rs6265) of the BDNF gene with three quantitative traits simultaneously, namely, intelligence quotient (IQ), body mass index (BMI), and blood pressure (BP).

Methods

Psychometric, morphometric, and physiometric data of the total participants (N = 246) were collected. WASI-II^INDIA was used to measure cognitive ability. Genotyping was carried out using allele-specific PCR for the rs6265 polymorphism (C196T), and genotypes were determined. Statistical analyses were performed at p < 0.05 significance level using MS-Excel and SigmaPlot. The odds ratio models with a 95% confidence interval were used to test the associations. The used models are co-dominant, recessive, dominant, over-dominant, and additive.

Results

The allelic frequencies of alleles C and T were 72 and 28%, respectively. Under the dominant genetic model, a significant susceptible association of minor allele T was observed with a lower average verbal comprehensive index (OR = 2.216, p = 0.003, CI (95%) =1.33-3.69), a lower average performance reasoning index (OR = 2.634, p < 0.001, CI (95%) = 1.573-4.41), and a lower average full-scale IQ-4 (OR = 3.159, p < 0.001, CI (95%) = 1.873-5.328). Carriers of Met-alleles were found to have an increased body mass index (OR = 2.538, p < 0.001, CI (95%) = 1.507-4.275), decreased systolic blood pressure (OR = 2.051, p = 0.012, CI (95%) = 1.202-3.502), and decreased diastolic blood pressure (OR = 2.162, p = 0.006, CI (95%) = 1.278-3.657). Under the recessive genetic model, several folds decrease in IQ and BP and an increase in BMI with the presence of the T allele was also detected.

Conclusion

This novel study may improve our understanding of genetic alterations to the traits and hence be helpful for clinicians and researchers to investigate the diagnostic and prognostic value of this neurotrophic factor.

The Role of Brain-Derived Neurotrophic Factor (BDNF) in Diagnosis and Treatment of Epilepsy, Depression, Schizophrenia, Anorexia Nervosa and Alzheimer's Disease as Highly Drug-Resistant Diseases: A Narrative Review

Brain-derived neurotrophic factor (BDNF) belongs to the family of neurotrophins, which are growth factors with trophic effects on neurons. BDNF is the most widely distributed neurotrophin in the central nervous system (CNS) and is highly expressed in the prefrontal cortex (PFC) and hippocampus. Its distribution outside the CNS has also been demonstrated, but most studies have focused on its effects in neuropsychiatric disorders. Despite the advances in medicine in recent decades, neurological and psychiatric diseases are still characterized by high drug resistance. This review focuses on the use of BDNF in the developmental assessment, treatment monitoring, and pharmacotherapy of selected diseases, with a particular emphasis on epilepsy, depression, anorexia, obesity, schizophrenia, and Alzheimer's disease. The limitations of using a molecule with such a wide distribution range and inconsistent method of determination are also highlighted.

Chronic consumption of a hypercaloric diet increases neuroinflammation and brain senescence, promoting cognitive decline in middle-aged female Wistar rats

Being overweight and obesity are world health problems, with a higher prevalence in women, defined as abnormal or excessive fat accumulation that increases the risk of chronic diseases. Excess energy leads to adipose expansion, generating hypertrophic adipocytes that produce various pro-inflammatory molecules. These molecules cause chronic low-intensity inflammation, affecting the organism's functioning and the central nervous system (CNS), inducing neuroinflammation. The neuroinflammatory response during obesity occurs in different structures of the CNS involved in memory and learning, such as the cortex and the hippocampus. Here we analyzed how obesity-related peripheral inflammation can affect CNS physiology, generating neuroinflammation and promoting cellular senescence establishment. Since some studies have shown an increase in senescent cells during aging, obesity, and neurodegenerative diseases, we proposed that cellular senescence participation may contribute to the cognitive decline in an obesity model of middle-aged female Wistar rats. The inflammatory state of 6 and 13 months-old female Wistar rats fed with a hypercaloric diet was measured in serum and CNS (cortex and hippocampus). Memory was evaluated using the novel object recognition (NOR) test; the presence of senescent markers was also determined. Our data suggest that the systemic inflammation generated by obesity induces a neuroinflammatory state in regions involved in learning and memory, with an increase in senescent markers, thus proposing senescence as a potential participant in the negative consequences of obesity in cognition.

Associations of Plasma BDNF and BDNF Gene Polymorphism with Cardiometabolic Parameters in Thai Children: A Pilot Study

Background

Childhood obesity is an important public health crisis worldwide. The brain-derived neurotrophic factor (BDNF) has been demonstrated to play a role in controlling energy homeostasis and cardiovascular regulation.

Objectives

To examine brain-derived neurotrophic factor (BDNF) levels and anthropometric-cardiometabolic and hematological parameters in obese and nonobese children and to determine whether two BDNF gene polymorphisms (G196A and C270T) are linked to BDNF levels, obesity, and anthropometric-cardiometabolic and hematological parameters among Thai children.

Methods

This case-control study included an analysis of 469 Thai children: 279 healthy nonobese and 190 obese children. Anthropometric-cardiometabolic and hematological variables and BDNF levels were measured. Genotyping of BDNF G196A and C270T was performed using the polymerase chain reaction-restriction fragment length polymorphism technique.

Results

Children in the obese group had significantly higher white blood cell counts and some cardiometabolic parameters. Although the difference in BDNF level between the nonobese and obese groups was not significant, BDNF level was significantly positively correlated with hematological and cardiometabolic parameters, including blood pressure, triglycerides, and triglycerides and the glucose index. The BDNF G196A polymorphism in children was only associated with decreased systolic blood pressure (p < 0.05), while the BDNF C270T polymorphism was found not to be related to BDNF levels, obesity, or other parameters after adjusting for potential covariates.

Conclusions

These findings in Thai children suggest that obesity is associated with increased cardiometabolic risk factors, but not with BDNF levels or the two BDNF polymorphisms studied, while the BDNF G196A polymorphism is a beneficial marker for controlling blood pressure among Thai children.

Effects of Peripheral Neural Blocks in Laparoscopic Sleeve Gastrectomy: a Pilot Study on Cognitive Functions in Severe Obese Patients

BACKGROUND

In addition to the analgesic effect, peripheral neural blocks also prevent cognitive impairment and peripheral inflammation induced by surgery. However, it is unknown if there is collateral impact on cognitive improvement after bariatric surgery.

METHODS

In this pilot study, 75 patients with severe obesity for selective laparoscopic sleeve gastrectomy (LSG) were recruited and randomized into three groups (1:1:1) as general anesthesia (GA) group, transverse abdominis plane block (TAPB) group, and quadratus lumborum block (QLB) group. Bilateral TAPB or QLB was performed (0.33% ropivacaine with dexmedetomidine 1 μg/kg) before the standardized general anesthesia. Cognitive test battery was completed before LSG and in 1-month and 3-month follow-up. The levels of peripheral inflammatory cytokines were determined at equivalent time points.

RESULTS

Patients with LSG exhibited massive cognitive improvement in postoperative 3 month without or with TAPB or QLB (P_time < 0.001). Compared to GA, QLB significantly strengthened performance in MoCA (β = 0.56, 95%CI: 0.08, 1.05). IL-6, IL-8, and high-sensitivity CRP significantly verified among three groups. Changes in IL-6 within postoperative 3 months were negatively correlated with MMSE and MoCA, and positively correlated with AVLT-DR for QLB group. Similar correlation was found in the GA group for changes in IL-6 and AVLT-IR.

CONCLUSION

Laparoscopic sleeve gastrectomy ideally improved memory and attention as early as postoperative 1 month. QLB promoted cognitive improvement in MoCA, which was negatively correlated with changes in IL-6. More precise trials are needed to determine the overall effect of peripheral neural block on cognition following bariatric surgery.

The Association between Brain-Derived Neurotrophic Factor (BDNF) Protein Level and Body Mass Index

Background and Objectives: Obesity is a major health concern worldwide. Many studies emphasize the important role of brain-derived neurotrophic factor (BDNF) in regulating appetite and body weight. We aimed to investigate the association between BDNF protein serum levels and body mass index (BMI). Materials and Methods: We conducted a cross-sectional study among 108 healthy adult participants divided into six categories depending on their body mass index (BMI). The ages of the participants ranged between 21 to 45 years. The BDNF serum level was measured using the enzyme-linked immunosorbent assay (ELISA) technique. Results: A Kruskal−Wallis test showed a significant difference in BDNF between the different BMI categories, χ2(2) = 24.201, p < 0.001. Our data also showed that BDNF levels were significantly lower in people with obesity classes II and III than those of normal weight (p < 0.05). The Spearman rank correlation test was statistically significant with negative correlations between the BMI and BDNF (r) = −0.478, (p < 0.01). Moreover, we observed a negative dose-dependent relationship pattern between BMI categories and the levels of circulating BDNF protein. Conclusions: In this study, our data support the hypothesis that low serum levels of BDNF are associated with high BMI and obesity in Saudi adults.

Potential Effects of Resistant Exercise on Cognitive and Muscle Functions Mediated by Myokines in Sarcopenic Obese Mice

Recently, it has been demonstrated that in sarcopenic obesity (SO), physical activity could improve cognitive functions. Moreover, previous studies suggested that muscle contraction could influence cognitive function via myokines. This study investigated the potential effects of resistant exercise on cognitive and muscle functions in SO. SO was induced by a high-fat diet treatment for 8 weeks in 8-month-old male C57BL/6J mice. Then, resistant exercise (ladder climbing) for 8 weeks was performed. Muscle and cognitive function tests and morphological analysis were conducted. The protein levels of myokines were investigated in muscle, plasma, and the hippocampus in sarcopenic obese mice. Muscle and cognitive functions were significantly elevated in the obesity-exercise group (EX) compared to the obesity-control group (OB). Interestingly, muscle function was positively correlated with cognitive function. Abnormal morphological changes in the hippocampus were ameliorated in EX compared to OB, but not in the muscle. Protein levels of cognitive function-related myokines and energy metabolism-related markers in EX were significantly elevated in both muscle and hippocampus compared to those in OB. Interestingly, the protein level of brain-derived neurotrophic factor (BDNF) in EX was simultaneously increased in all tissues including muscle, plasma, and hippocampus compared to that in OB. In conclusion, modulation of muscle-derived cognitive function-related myokines in various pathological conditions via a resistant exercise could be a possible way of relieving muscle and cognitive dysfunction.

Zinc Supplementation Partially Decreases the Harmful Effects of a Cafeteria Diet in Rats but Does Not Prevent Intestinal Dysbiosis

Zinc (Zn) plays an important role in metabolic homeostasis and may modulate neurological impairment related to obesity. The present study aimed to evaluate the effect of Zn supplementation on the intestinal microbiota, fatty acid profile, and neurofunctional parameters in obese male Wistar rats. Rats were fed a cafeteria diet (CAF), composed of ultra-processed and highly caloric and palatable foods, for 20 weeks to induce obesity. From week 16, Zn supplementation was started (10 mg/kg/day). At the end of the experiment, we evaluated the colon morphology, composition of gut microbiota, intestinal fatty acids, integrity of the intestinal barrier and blood-brain barrier (BBB), and neuroplasticity markers in the cerebral cortex and hippocampus. Obese rats showed dysbiosis, morphological changes, short-chain fatty acid (SCFA) reduction, and increased saturated fatty acids in the colon. BBB may also be compromised in CAF-fed animals, as claudin-5 expression is reduced in the cerebral cortex. In addition, synaptophysin was decreased in the hippocampus, which may affect synaptic function. Our findings showed that Zn could not protect obese animals from intestinal dysbiosis. However, an increase in acetate levels was observed, which suggests a partial beneficial effect of Zn. Thus, Zn supplementation may not be sufficient to protect from obesity-related dysfunctions.

Association of Sleep, Body Weight and Physical Exercise with Plasma BDNF Levels in Healthy Male Saudi Smokers

Introduction

Brain-derived neurotrophic factor (BDNF) has been shown to impact neural function and development. The BDNF plasma levels may be affected by a smoker’s behavior. Thus, the aim of this study was to investigate the association between sleep, body weight and physical exercise with brain-derived neurotrophic factor (BDNF) in healthy male Saudi smokers.

Methods

A cross-sectional study, with a convenience sample, was conducted during personal visits to the Anti-Smoking Clinic and Family and Community Medical Center of Imam Abdurrahman Bin Faisal University (IAU) in Dammam at the end of 2018. Blood samples were taken from participants to measure the BDNF plasma levels. Multiple linear regression analysis was used to examine the relationship between plasma BDNF levels and participants’ background characteristics, such as smoking index, physical activity, body mass index (BMI) and Pittsburgh sleep quality index (PSQI).

Results

A sample of 73 (31 smokers and 42 non-smokers) males took part in the study. The results demonstrated a significant relationship between plasma BDNF levels with physical activity, smoking age, smoking index, PSQI and BMI 25–29.9 (overweight). However, the results showed no significant relationship between plasma BDNF levels and BMI (healthy weight) and obesity.

Conclusion

This study shows that physical activity and sleeping quality can provide a positive impact against smoking-associated variation of the BDNF plasma levels, which may affect the health of Saudi males. Further investigation is needed to understand what other potential background characteristics are best predictive or correlated with BDNF plasma levels.

Brain-Derived Neurotrophic Factor and Extracellular Vesicle-Derived miRNAs in an Italian Cohort of Individuals With Obesity: A Key to Explain the Link Between Depression and Atherothrombosis

Background

Obesity and depression are intertwined diseases often associated with an increased risk of cardiovascular (CV) complications. Brain-Derived Neurotrophic Factor (BDNF), altered in the brain both of subjects with depression and obesity, provides a potential link between depression and thrombosis. Since the relationship among peripheral BDNF, depression and obesity is not well-defined, the aim of the present report has been to address this issue taking advantage of the contribution played by extracellular vesicle (EV)-derived miRNAs.

Research Process

Associations among circulating BDNF, depression and EV-derived miRNAs related to atherothrombosis have been evaluated in a large Italian cohort of obese individuals (n = 743), characterized by the Beck Depression Inventory (BDI-II) score.

Results

BDI-II was negatively associated with BDNF levels without a significant impact of the rs6265 BDNF polymorphism; this association was modified by raised levels of IFN-γ. BDNF levels were linked to an increase of 80 EV-derived miRNAs and a decrease of 59 miRNAs related to atherosclerosis and thrombosis. Network analysis identified at least 18 genes targeted by these miRNAs, 7 of which involved in depression and CV risk. The observation of a possible link among BDNF, depression, and miRNAs related to atherothrombosis and depression in obesity is novel and may lead to a wider use of BDNF as a CV risk biomarker in this specific subject group.

Salivary Neurotrophins Brain-Derived Neurotrophic Factor and Nerve Growth Factor Associated with Childhood Obesity: A Multiplex Magnetic Luminescence Analysis

Obesity is linked with higher inflammatory markers and is characterized by chronic low-grade inflammation. Neurotrophins brain-derived neurotrophic factor (BDNF) and β-nerve growth factor (β-NGF), in addition to their neuronal functions, act on several immune cells and have been recently designated as metabokines due to their regulatory role in energy homeostasis and food intake. The current study evaluates the salivary BDNF and β-NGF and their association with anthropometric measurement, blood pressure, and salivary insulin in children. Anthropometric measurements and saliva samples were obtained from 76 children, aged 6–10 years. Multiplex analysis was carried out for the salivary analysis of BDNF, NGF, and insulin by human magnetic Luminex performance assay. Statistical analysis was performed to analyze the best fit diagnostic value for biomarkers and the relationship of the neurotrophic levels of BDNF and NGF with obesity measures and blood pressure. Salivary BDNF and β-NGF showed a significantly higher concentration in obese children than normal-weight children. Both neurotrophins are positively associated with obesity anthropometric measures, blood pressure, and salivary insulin. Multinominal regression analysis reported a significant association between salivary BDNF, β-NGF, insulin, and systolic pressure adjusted for age, gender, income, and maternal education. The salivary concentration of BDNF and NGF was higher in obese children, and it is positively associated with anthropometric measures, suggesting that neurotrophins can be used as a non-invasive predictor of obesity-related complications in children.

Serum alpha-melanocyte-stimulating hormone (a-MSH), brain-derived neurotrophic factor (BDNF), and agouti-related protein (AGRP) levels in children with Prader-Willi or Bardet-Biedl syndromes

BACKGROUND

Although leptin/melanocortin pathway pathologies in hypothalamus are thought to be the main cause of early-onset obesity and hyperphagia in PWS and BBS, the exact mechanism is still not known.

OBJECTIVE

To measure serum concentrations of a-MSH, BDNF and AGRP in a group of children with BBS or PWS.

METHODS

We recruited 12 subjects with PWS, 12 subjects with BBS, 28 obese controls (OC) and 26 lean controls (LC) matched for age, sex and puberty. Serum a-MSH, BDNF and AGRP levels were measured by the ELISA method.

RESULTS

The mean a-MSH level was lower in PWS than those of OC and LC (3729 ± 1319, 5211 ± 829 and 5681 ± 565 pg/ml, respectively, p < 0.001), and mean a-MSH was lower in OC than LC (p < 0.05). The mean BDNF level of PWS was higher than those of OC and LC (565 ± 122, 482 ± 102 and 391 ± 74 pg/ml, respectively, p < 0.001). On the other hand, mean a-MSH level of BBS was lower than those of OC and LC (4543 ± 658, 5211 ± 829 and 5681 ± 565 pg/ml, respectively, p < 0.001), and mean a-MSH was lower in OC than LC (p < 0.05). The mean BDNF level of BBS was higher than those of OC and LC (583 ± 115, 482 ± 102 and 391 ± 74 pg/ml, respectively, p < 0.001). Additionally, both in PWS and BBS, the mean BDNF level was higher in OC than LC (p < 0.01). Regarding AGRP level, there was no difference both in BBS and PWS compared to OC.

CONCLUSION

We found that the serum a-MSH levels of PWS and BBS groups are significantly lower compared to those of obese and lean controls. Therefore, we can speculate that the circulating a-MSH level does properly reflect its central production, and the serum a-MSH level might be a good biomarker to detect a-MSH deficiency in individuals suspected to have BBS or PWS, and also in those with POMC, PCSK1, and LEPR deficiency.

DNA methylome-wide association study of genetic risk for depression implicates antigen processing and immune responses

BACKGROUND

Depression is a disabling and highly prevalent condition where genetic and epigenetic, such as DNA methylation (DNAm), differences contribute to disease risk. DNA methylation is influenced by genetic variation but the association between polygenic risk of depression and DNA methylation is unknown.

METHODS

We investigated the association between polygenic risk scores (PRS) for depression and DNAm by conducting a methylome-wide association study (MWAS) in Generation Scotland (N = 8898, mean age = 49.8 years) with replication in the Lothian Birth Cohorts of 1921 and 1936 and adults in the Avon Longitudinal Study of Parents and Children (ALSPAC) (Ncombined = 2049, mean age = 79.1, 69.6 and 47.2 years, respectively). We also conducted a replication MWAS in the ALSPAC children (N = 423, mean age = 17.1 years). Gene ontology analysis was conducted for the cytosine-guanine dinucleotide (CpG) probes significantly associated with depression PRS, followed by Mendelian randomisation (MR) analysis to infer the causal relationship between depression and DNAm.

RESULTS

Widespread associations (NCpG = 71, pBonferroni < 0.05, p < 6.3 × 10-8) were found between PRS constructed using genetic risk variants for depression and DNAm in CpG probes that localised to genes involved in immune responses and neural development. The effect sizes for the significant associations were highly correlated between the discovery and replication samples in adults (r = 0.79) and in adolescents (r = 0.82). Gene Ontology analysis showed that significant CpG probes are enriched in immunological processes in the human leukocyte antigen system. Additional MWAS was conducted for each lead genetic risk variant. Over 47.9% of the independent genetic risk variants included in the PRS showed associations with DNAm in CpG probes located in both the same (cis) and distal (trans) locations to the genetic loci (pBonferroni < 0.045). Subsequent MR analysis showed that there are a greater number of causal effects found from DNAm to depression than vice versa (DNAm to depression: pFDR ranged from 0.024 to 7.45 × 10-30; depression to DNAm: pFDR ranged from 0.028 to 0.003).

CONCLUSIONS

PRS for depression, especially those constructed from genome-wide significant genetic risk variants, showed methylome-wide differences associated with immune responses. Findings from MR analysis provided evidence for causal effect of DNAm to depression.

High maternal BMI and low maternal blood BDNF may determine the limit of detection of amniotic fluid BDNF throughout gestation: Analysis of mother-fetus trios and literature review

Objective

An increasing number of studies show the importance of brain-derived neurotrophic factor (BDNF) acting at the feto-placental interface, however, only a few studies describe BDNF levels in amniotic fluid (AF).

Methods

In this cross-sectional, prospective study, 109 maternal blood-amniotic fluid pairs (including 66 maternal blood-fetal-blood-amniotic fluid trios) were analyzed. BDNF concentrations were measured with a commercially available immunoassay.

Results

In 71 AF from 109 samples, AF-BDNF concentrations were below the lowest limit of Quantitation (LLoQ) of 1.19 pg/ml (group A), leaving 38 samples with measurable BDNF concentrations (group B). Patients in group A showed significantly higher maternal BMI before pregnancy (mean±SD 26.3± 6.7 (kg/m²) vs. 23.8 ±4.5 (kg/m²) p = 0.04) and lower maternal blood BDNF concentrations than the other group (mean±SD 510.6 ± 554.7 pg/ml vs. mean±SD 910.1± 690.1 pg/ml; p<0.0001). Spearman correlation showed a negative correlation between maternal BMI before pregnancy and maternal BDNF concentrations (r = -0.25, p = 0.01).

Conclusion

Our study is the first to correlate AF-BDNF samples with the corresponding maternal and fetal blood-BDNF samples. The significant negative correlation between maternal BMI before pregnancy and maternal BDNF and AF-BDNF concentrations below the limit of detection has to be evaluated in further studies.

Gut Microbiota Regulates the Sympathetic Nerve Activity and Peripheral Serotonin Through Hypothalamic MicroRNA-204 in Order to Increase the Browning of White Adipose Tissue in Obesity

The prevalence of obesity is increasing worldwide, and novel therapeutic strategies such as enhancement of thermogenic pathways in white adipose tissue (WAT) are gaining more attention. The gut/brain axis plays an essential role in promoting the browning of WAT. However, the mechanism by which this axis regulates WAT function is not fully understood. On the other hand, the role of microRNAs (miRNAs) in the control of WAT browning has already been established. Therefore, understanding the communication pathways linking the gut/brain axis and miRNAs might establish a promising intervention for obesity. Our published data showed that microRNA-204 (miR-204), a microRNA that plays an important role in the control of the central nervous system (CNS) and the pathogenesis of obesity, is affected by gut dysbiosis. Therefore, miR-204 could be a key element that controls the browning of WAT by acting as a potential link between the gut microbiota and the brain. In this review, we summarized the current knowledge about communication pathways between the brain, gut, and miR-204 and examined the literature to discuss potential research directions that might lead to a better understanding of the mechanisms underlying the browning of WAT in obesity.

Cis-regulatory architecture of human ESC-derived hypothalamic neuron differentiation aids in variant-to-gene mapping of relevant complex traits

The hypothalamus regulates metabolic homeostasis by influencing behavior and endocrine systems. Given its role governing key traits, such as body weight and reproductive timing, understanding the genetic regulation of hypothalamic development and function could yield insights into disease pathogenesis. However, given its inaccessibility, studying human hypothalamic gene regulation has proven challenging. To address this gap, we generate a high-resolution chromatin architecture atlas of an established embryonic stem cell derived hypothalamic-like neuron model across three stages of in vitro differentiation. We profile accessible chromatin and identify physical contacts between gene promoters and putative cis-regulatory elements to characterize global regulatory landscape changes during hypothalamic differentiation. Next, we integrate these data with GWAS loci for various complex traits, identifying multiple candidate effector genes. Our results reveal common target genes for these traits, potentially affecting core developmental pathways. Our atlas will enable future efforts to determine hypothalamic mechanisms influencing disease susceptibility.

Brain Derived Neurotrophic Factor and Serotonin Levels in Autistic Children: Do They Differ in Obesity?

BACKGROUND: The risk of obesity among autism spectrum disorder (ASD) children is high which could be related to a disorder in their metabolism. Brain derived neurotrophic factor (BDNF) is involved in metabolic control, language behavior, and intellectual development. Serotonin has a role in satiety and energy expenditure. AIM: Therefore, the aim of this study was to measure the serum levels of BDNF and serotonin in obese compared to non-obese ASD children. The influence of obesity on ASD severity, intellectual, and language development was also investigated. METHODS: The study included 60 autistic children (Group I: 30 ASD children with obesity and Group II: 30 ASD children without obesity). The serum BDNF and serotonin levels were estimated by ELISA and by high-performance liquid chromatography. RESULTS: All participants manifested delayed language development. Almost all of them had intellectual disability. The difference between groups regarding ASD severity, language, and intellectual development was non-significant. However, BDNF level in obese group was less than that in the other group while serotonin was higher in the obese group with significant statistical difference. CONCLUSION: The difference between the groups regarding the levels of BDNF and serotonin, which are involved in the brain development, could be related to obesity. The influence of obesity on ASD severity, intellectual, and language development of ASD children was not distinctive in the participants. The influence of such markers on ASD severity and cognitive performance needs further investigations.

Negative Correlation between Serum Brain-derived Neurotrophic Factor Levels and Obesity Predictor Markers and Inflammation Levels in Females with Obesity

BACKGROUND: Obesity has been widely associated with structural and functional changes in the brain, whereas inflammation is one of the potential mechanisms involved in these changes. OBJECTIVE: This study aims to prove the relationship between serum brain-derived neurotrophic factor (BDNF) levels and obesity predictor markers (body mass index and waist to hip ratio) and inflammation (interleukin-6 and Tumor Necrosis Factor-alpha) levels in females with obesity. METHODS: This study used a cross-sectional study method using 33 females with obesity aged 19-23 years, body mass index (BMI) > 27.5 kg/m2, normal blood pressure, normal resting heart rate (RHR), normal hemoglobin (Hb), and fasting blood glucose (FBG) ≤ 100 mg/dL. The examination of serum BDNF, IL-6, and TNF-α levels using the Enzyme-Linked Immunosorbent Assay (ELISA) method. The data were analyzed using Pearson product-moment test with a significant levels p<0.05. RESULTS: The results indicated that there is a negative correlation between serum BDNF levels and BMI (r = –0.759; p<0.001), WHR (r = –0.675; p<0.001), IL-6 levels (r = –0.530; p<0.001) and TNF-α levels (r = –0.561; p<0.001). CONCLUSION: Based on the results of the study, there is a negative correlation between serum BDNF levels and BMI, waist to hip ratio, and inflammation (interleukin-6 and Tumor Necrosis Factor-alpha) levels in females with obesity. Further studies are needed to confirm the present findings.

The Impact of Physical Exercise on the Circulating Levels of BDNF and NT 4/5: A Review

(1) Background: One mechanism through which physical activity (PA) provides benefits is by triggering activity at a molecular level, where neurotrophins (NTs) are known to play an important role. However, the expression of the circulating levels of neurotrophic factors, brain-derived neurotrophic factor (BDNF) and neurotrophin-4 (NT-4/5), in response to exercise, is not fully understood. Therefore, the aim was to provide an updated overview on the neurotrophin (NT) variation levels of BDNF and NT-4/5 as a consequence of a long-term aerobic exercise intervention, and to understand and describe whether the upregulation of circulating NT levels is a result of neurotrophic factors produced and released from the brain, and/or from neurotrophic secreting peripheral organs. (2) Methods: The articles were collected from PubMed, SPORTDiscus, Web of Science, MEDLINE, and Embase. Data were analyzed through a narrative synthesis. (3) Results: 30 articles studied humans who performed training protocols that ranged from 4 to 48 weeks; 22 articles studied rodents with an intervention period that ranged from 4 to 64 weeks. (4) Conclusions: There is no unanimity between the upregulation of BDNF in humans; conversely, concerning both BDNF and NT-4/5 in animal models, the results are heterogeneous. Whilst BDNF upregulation appears to be in relative agreement, NT-4/5 seems to display contradictory and inconsistent conclusions.

A systematic review and meta-analysis of association between brain-derived neurotrophic factor and type 2 diabetes and glycemic profile

Several epidemiologic studies have evaluated the relation between serum/plasma brain-derived neurotrophic factor (BDNF) levels and glycemic parameters, but the findings were conflicting. We performed a systematic review and meta-analysis to compare circulating BDNF levels in individuals with type 2 diabetes (T2D) or other glycemic disorders with healthy controls and to evaluate correlation between BDNF concentrations with glycemic profile. A systematic search up to July 2020 was conducted in reliable electronic databases (MEDLINE (Pubmed), EMBASE, Scopus) and Google scholar. Sixteen observational studies compared serum/plasma BDNF levels in diabetic patients (or individuals with glycemic disorders) vs. healthy controls or reported correlations between serum BDNF levels and glycemic parameters in adults were included in the review. Overall weighted mean difference (WMD) of circulating BDNF levels in 1306 patients with T2D (or other glycemic disorders) was 1.12 ng/mL lower than 1250 healthy subjects (WMD: − 1.12; 95%CI − 1.37, − 0.88, I² = 98.7%, P < 0.001). Subgroup analysis revealed that both diabetic patients and subjects with other glycemic disorders had lower serum/plasma BDNF levels than healthy controls (WMD: − 1.74; 95%CI − 2.15, − 1.33 and WMD: − 0.49; 95%CI − 0.82, − 0.16, respectively). No significant correlation was found between BDNF levels and glycemic parameters [fasting blood glucose (FBG) (Fisher’s Z = 0.05; 95%CI − 0.21, 0.11; n = 1400), homeostatic model assessment for insulin resistance (HOMA-IR) (Fisher’s Z = 0.12; 95%CI − 0.20, 0.44; n = 732) and glycosylated hemoglobin (HbA1c) (Fisher’s Z = 0.04; 95%CI − 0.05, 0.12; n = 2222)]. We found that diabetic patients and subjects with glycemic disorders had lower circulating BDNF levels than healthy controls. However, there was no significant correlation between BDNF concentrations and glycemic parameters including FBG, HOMA-IR and HbA1c. Further prospective investigations are required to confirm these findings.

Appetite- and weight-inducing and -inhibiting neuroendocrine factors in Prader-Willi syndrome, Bardet-Biedl syndrome and craniopharyngioma versus anorexia nervosa

Obesity is reaching an epidemic state and has a major impact on health and economy. In most cases, obesity is caused by lifestyle factors. However, the risk of becoming obese differs highly between people. Individual's differences in lifestyle, genetic, and neuroendocrine factors play a role in satiety, hunger and regulation of body weight. In a small percentage of children and adults with obesity, an underlying hormonal or genetic cause can be found. The aim of this review is to present and compare data on the extreme ends of the obesity and undernutrition spectrum in patients with Prader-Willi syndrome (PWS), Bardet-Biedl syndrome (BBS), acquired hypothalamic obesity in craniopharyngioma patients, and anorexia nervosa. This may give more insight into the role of neuroendocrine factors and might give direction for future research in conditions of severe obesity and underweight.

Examining the effect of obesity-associated gene variants on breast cancer survivors in a randomized weight loss intervention

PURPOSE

Our study examined whether common variants of obesity-associated genes FTO, MC4R, BDNF, and CREB1 moderated the effects of a lifestyle intervention on weight change among breast cancer survivors.

METHODS

151 breast cancer survivors with a body mass index ≥ 25 kg/m² were randomly assigned to a 6-month weight loss intervention or usual care group. Genotyping of FTO rs9939609, MC4R rs6567160, BDNF rs11030104, CREB1 rs17203016 was performed. Linear mixed models were used including the main effects of genotype (assuming a dominant genetic model), treatment arm on weight and percent body fat changes, and genotype by treatment interaction variable. All statistical tests were evaluated against a Bonferroni-corrected alpha of 0.0125.

RESULTS

Women in the intervention group achieved significantly greater weight loss than the usual care group (5.9% vs 0.4%, p < 0.001), regardless of genotype. Changes in weight and percent body fat did not differ significantly between carriers of the FTO rs9939609, MC4R rs6567160, BDNF rs11030104, and CREB1 rs17203016 risk alleles compared to non-carriers (p-interaction > 0.0125 for each single-nucleotide polymorphisms).

CONCLUSIONS

Women who are genetically predisposed to obesity and recently diagnosed with breast cancer may achieve significant and clinically meaningful weight loss through healthy eating and exercise.

CLINICAL TRIAL REGISTRATION

NCT02863887 (Date of Registration: August 11, 2016); NCT02110641 (Date of Registration: April 10, 2014).

Brain-Derived Neurotrophic Factor Expression and Signaling in Different Perivascular Adipose Tissue Depots of Patients With Coronary Artery Disease

Background

Brain‐derived neurotrophic factor (BDNF) is expressed in neuronal and nonneuronal cells and may affect vascular functions via its receptor, tropomyosin‐related kinase B (TrkB). In this study, we determined the expression of BDNF in different perivascular adipose tissue (PVAT) depots of patients with established coronary atherosclerosis.

Methods and Results

Serum, vascular tissue, and PVAT surrounding the proximal aorta (C‐PVAT) or internal mammary artery (IMA‐PVAT) was obtained from 24 patients (79% men; mean age, 71.7±9.7 years; median body mass index, 27.4±4.8 kg/m²) with coronary atherosclerosis undergoing elective coronary artery bypass surgery. BDNF protein levels were significantly higher in C‐PVAT compared with IMA‐PVAT, independent of obesity, metabolic syndrome, or systemic biomarkers of inflammation. mRNA transcripts of TrkB, the BDNF receptor, were significantly reduced in aorta compared with IMA. Vessel wall TrkB immunosignals colocalized with cells expressing smooth muscle cell markers, and confocal microscopy and flow cytometry confirmed BDNF receptor expression in human aortic smooth muscle cells. Significantly elevated levels of protein tyrosine phosphatase 1B, a negative regulator of TrkB signaling in the brain, were also observed in C‐PVAT. In vitro, inhibition of protein tyrosine phosphatase 1B blunted the effects of BDNF on smooth muscle cell proliferation, migration, differentiation, and collagen production, possibly by upregulation of low‐affinity p75 neurotrophin receptors. Expression of nerve growth factor or its receptor tropomyosin‐related kinase A did not differ between C‐PVAT and IMA‐PVAT.

Conclusions

Elevated expression of BDNF in parallel with local upregulation of negative regulators of neurotrophin signaling in perivascular fat and lower TrkB expression suggest that vascular BDNF signaling is reduced or lost in patients with coronary atherosclerosis.

The beneficial role of the synthetic microneurotrophin BNN20 in a focal demyelination model

BNN20, a C17-spiroepoxy derivative of the neurosteroid dehydroepiandrosterone, has been shown to exhibit strong neuroprotective properties but its role in glial populations has not been assessed. Our aim was to investigate the effect of BNN20 on glial populations by using in vitro and in vivo approaches, taking advantage of the well-established lysophosphatidylcholine (LPC)-induced focal demyelination mouse model. Our in vivo studies, performed in male mice, showed that BNN20 treatment leads to an increased number of mature oligodendrocytes (OLs) in this model. It diminishes astrocytic accumulation during the demyelination phase leading to a faster remyelination process, while it does not affect oligodendrocyte precursor cell recruitment or microglia/macrophage accumulation. Additionally, our in vitro studies showed that BNN20 acts directly to OLs and enhances their maturation even after they were treated with LPC. This beneficial effect of BNN20 is mediated, primarily, through the neurotrophin receptor TrkA. In addition, BNN20 reduces microglial activation and their transition to their pro-inflammatory state upon lipopolysaccharides stimulation in vitro. Taken together our results suggest that BNN20 could serve as an important molecule to develop blood-brain barrier-permeable synthetic agonists of neurotrophin receptors that could reduce inflammation, protect and increase the number of functional OLs by promoting their differentiation/maturation.