Changes In Brain-derived Neurotrophic Factor Levels Research Articles

Neuromuscular electrical stimulation to combat cognitive aging in people with spinal cord injury: protocol for a single case experimental design study

IntroductionIndividuals with spinal cord injury (SCI) can experience accelerated cognitive aging. Myokines (factors released from muscle cells during contractions), such as brain-derived neurotrophic factor (BDNF), are thought to have beneficial effects on cognition. Neuromuscular electrical stimulation (NMES) was shown to elicit a large release of myokines. However, the effects of NMES on cognitive function have not been studied.ObjectiveTo present the study protocol for a clinical trial evaluating the effects of NMES aimed at improving cognition and BDNF.MethodsA replicated randomized three-phases single-case experimental design (SCED) with sequential multiple baseline time series and a single-armed prospective trial will be conducted with 15 adults with chronic SCI (> 12 months after injury) above L1 neurological level undergoing 30-min quadriceps NMES, 3 days per week for 12 weeks.Main study endpointsPrimary endpoint is cognitive performance (assessed by a smartphone test) conducted three times per week during the baseline phase with random duration of 3 to 8 weeks, the intervention phase of 12 weeks, and the follow-up phase of 3 weeks after a no measurement rest period of 12 weeks. Secondary endpoints are changes in BDNF levels and cognitive performance measured before the baseline period, before and after intervention and after a 12 weeks follow-up.ConclusionThis will be the first study investigating the effects of 12 weeks NMES on both cognition and BDNF levels in individuals with SCI. The SCED results provide information on individual treatment effect courses which may direct future research.Trial registrationClinicalTrials.gov (NCT05822297, 12/01/2023).

Pre- and postoperative levels of serum brain-derived neurotrophic factor in neonates with congenital heart defects.

The objectives of this study were to assess the preoperative and postoperative serum brain- derived neurotrophic factor (BDNF) levels in neonates undergoing surgery for congenital heart defects (CHD). Also to explore the relationship between changes in BDNF levels and the impact of perioperative factors including intraoperative body temperature, aortic cross-clamp time, perfusion time, operation time, inotropic score, vasoactive inotropic score and lactate levels. Forty-four patients with CHD and 36 healthy neonates were included in the study. Blood samples for serum BDNF levels were collected three times: preoperatively, and at 24 and 72 hours postoperatively from each patient in the operated group. Additionally, samples were collected once from each individual in the non-operated case group and the control group. Serum BDNF levels were analyzed using the Elabscience ELISA (Enzyme-Linked Immunosorbent Assay) commercial kit. Cranial ultrasonography (USG) was performed on all infants with CHD. Following cardiac surgery, patients underwent second and third cranial USG examinations at 24 and 72 hours postoperatively, respectively. Forty-four consecutive patients with CHD were divided into two groups as follows: the operated group (n=30) and the non-operated group (n=14). Although there were no differences in the baseline serum BDNF levels between the case and control groups, the preoperative serum BDNF levels were significantly lower in the patients operated compared to the non-operated patients. The serum BDNF levels at the 24th hour postoperatively were higher than the preoperative levels. However, no significant correlation was found between the serum BDNF levels at 24 and 72 hours postoperatively as well as the cranial USG findings at corresponding times. Serum BDNF levels were initially lower in neonates with CHD who underwent surgery, but increased during the early postoperative period. These results suggest that serum BDNF levels are influenced by CHD and the postoperative period.

Effect of computerized cognitive training on mood, cognition, and serum brain-derived neurotrophic factor level in late-life depression - a pilot randomized controlled trial.

The aim of this pilot randomized controlled trial was to test the feasibility of a computerized cognitive training targeting executive dysfunction in late-life depression and to investigate its impact on mood, cognition, and brain-derived neurotrophic factor (BDNF) levels. A total of 28 community-living Chinese individuals aged 55-75 with moderate-to-severe depression and cognitive symptoms (but without mild cognitive impairment or dementia) were recruited from a community centre in Hong Kong. Participants were randomly allocated to either the experimental (receiving computerized cognitive training) or the control group (receiving computer-based health education). Both programs lasted for one hour and were conducted twice a week for 6 weeks at the community centre. We assessed mood using the Hamilton Rating Scale for Depression (HAM-D) and Patient Health Questionaire-9 (PHQ-9), cognition using the Montreal Cognitive Assessment (MoCA), and serum BDNF levels at baseline and follow-up. We performed repeated measures analysis of variance to compare the differences in outcome changes between groups and correlation analysis to test if changes in mood and cognition correlated with changes in BDNF level. Our sample had a mean age of 66.8 (SD = 5.3) years, a mean HAM-D score of 19.4 (SD = 7.5), and a mean PHQ-9 score of 18.0 (SD = 6.3). No adverse effects were reported. Significant differences were observed between the experimental and control groups in changes in HAM-D (-8.4 vs. -2.9; group difference = -5.5; p = 0.01), PHQ-9 (-6.6 vs. -0.6; -6.0; p < 0.001), MoCA (1.4 vs. -1.3; 2.7; p = 0.001), and serum BDNF levels (in pg/ml; 2088.3 vs. -3277.4; 5365.6; p = 0.02). Additionally, changes in HAM-D, PHQ-9, and MoCA scores correlated significantly with changes in BDNF level. With computerized cognitive training improving mood and cognition and increasing serum BDNF levels in 6 weeks, it may serve as a safe and effective evidence-based alternative or adjuvant treatment for late-life depression. https://www.chictr.org.cn/indexEN.html, identifier ChiCTR1900027029.

Effect of exercise interventions on brain-derived neurotrophic factor expression in people with overweight and obesity: protocol for a systematic review and meta-analysis

IntroductionEpidemic obesity (‘globobesity’) has led to a considerable rise in the prevalence and incidence of many disabling conditions, including cognitive dysfunction. Recent evidence has suggested that habitual exercise can alleviate...

The Influence of Electroconvulsive Therapy (ECT) on Brain-Derived Neurotrophic Factor (BDNF) Plasma Level in Patients with Schizophrenia-A Systematic Review and Meta-Analysis.

The main aim of this systematic review and meta-analysis is to establish whether there is a correlation between the brain-derived neurotrophic factor (BDNF) level and electroconvulsive therapy (ECT) treatment and the reduction in psychotic symptoms in patients diagnosed with schizophrenia. A systematic search of PubMed/Medline, Cochrane Library, Web of Science, Scopus and Embase was conducted up to March 2023. Inclusion criteria: studies in which adult patients with schizophrenia treated with antipsychotic medication received ECT therapy and had the BDNF level measured before and after ECT treatment. Exclusion criteria: animal and in vitro studies or studies not involving complete information about the treatment and concentration of BDNF in plasma. The risk of bias was assessed using Egger's regression-based test for meta-analysis with continuous outcomes. Six studies comprising 248 individuals with schizophrenia were included. A statistically significant increase in BDNF levels after ECT treatment was observed only in two studies (p < 0.001 and p < 0.027, respectively), whereas in four other studies, an upward trend without statistical significance was noticed. The estimated overall size effect revealed that ECT therapy caused a slight change in the BDNF level but without statistical significance (ES = -0.328). Different numbers of ECT procedures (4-10), final measurement of the BDNF level made at a different time point, using bilateral or unilateral electrode positioning during ECT and treatment with different combinations of typical or atypical antipsychotic medications may be potential reasons for the lack of statistical significance in the changes in BDNF levels after treatment. Data regarding the measurement of BDNF levels pre and post ECT therapy in patients with schizophrenia are very limited without an extended follow-up period and evaluation of mental health change. Our meta-analysis showed that treatment with ECT therapy and antipsychotic medication increases serum BDNF levels in patients with drug-resistant schizophrenia compared to patients treated with medication only; however, this effect is not statistically significant.

Association of serum brain-derived neurotrophic factor level and early response to antipsychotic drug in first-episode patients with schizophrenia.

To investigate the role of Brain derived neurotrophic factor (BDNF) in the psychotic symptoms in first-episode patients with schizophrenia and whether BDNF levels were associated with the improvement of psychotic symptoms after risperidone treatment. 89 schizophrenia patients and 90 healthy controls were recruited, the schizophrenia patients were assigned into early response or early non-response groups at 2weeks based on improvement in the positive and negative symptoms scale (PANSS) total score. All patients were treated with risperidone for 2weeks, their serum BDNF levels were compared at baseline and after 2weeks treatment. We found that patients had lower BDNF levels, compared to controls at baseline. After 2weeks of treatment of risperidone, BDNF levels were significantly increased and psychotic symptoms were decreased in early response group. Correlation analysis showed that the change of BDNF levels after treatment was correlated with the change of PANSS total score. Further regression analysis showed that the change in BDNF levels was an independent predictor for the improvement in psychotic symptoms. Our findings reveal that the level of BDNF was lower in first-episode schizophrenic patients, moreover, the changes in serum BDNF levels may have a predictive effect on the early improvement in psychotic symptoms in the first 2weeks.

Omega-3 polyunsaturated fatty acids (n-3 PUFAs), somatic and fatigue symptoms in cardiovascular diseases comorbid major depressive disorder (MDD): A randomized controlled trial

IntroductionCardiovascular diseases (CVDs) and major depressive disorder (MDD) are the two most disabling diseases. Patients with CVDs comorbid depression had somatic and fatigue symptoms and were associated with chronic inflammation and omega-3 polyunsaturated fatty acid (n-3 PUFA) deficits. However, there have been limited studies on the effects of n-3 PUFAs on somatic and fatigue symptoms in patients with CVDs comorbid MDD. MethodForty patients with CVDs comorbid MDD (58% males, mean age of 60 ± 9 years) were enrolled and randomised to receive either n-3 PUFAs (2 g of eicosapentaenoic acid [EPA] and 1 g of docosahexaenoic acid[DHA] per day) or placebo in a 12-week double-blind clinical trial. We assessed the somatic symptoms with Neurotoxicity Rating Scale (NRS) and fatigue symptoms with Fatigue Scale at baseline, weeks 1, 2, 4, 8 and 12, as well as blood levels of Brain-Derived Neurotrophic Factor (BDNF), inflammatory biomarkers and PUFAs, at the baseline and week 12. ResultsThe n-3 PUFAs group had a greater reduction in Fatigue scores than the placebo group at Week 4 (p =.042), while there were no differences in the changes of NRS scores. N-3 PUFAs group also had a greater increase in EPA (p =.001) and a greater decrease in total n-6 PUFAs (p =.030). Moreover, in the subgroup analyses in the younger age group (age < 55), the n-3 PUFAs group had a greater reduction on NRS total scores at Week 12 (p =.012) and NRS Somatic scores at Week 2 (p =.010), Week 8 (p =.027), Week 12 (p =.012) than the placebo group. In addition, the pre- and post-treatment changes of EPA and total n-3 PUFAs levels were negatively associated with the changes of NRS scores at Weeks 2, 4, and 8 (all p <.05), and the changes of BDNF levels were negatively associated with NRS scores at Weeks 8 and 12 (both p <.05) in the younger age group. In the older age group (age ≥ 55), there were a lesser reduction on NRS scores at Weeks 1, 2 and 4 (all p <.05), but a greater reduction on Fatigue score at Week 4 (p =.026), compared to the placebo group. There was no significant correlation between the changes of blood BDNF, inflammation, PUFAs and NRS and Fatigue scores in general and in the older age group. ConclusionOverall, n-3 PUFAs improved the fatigue symptoms in patients with CVDs comorbid MDD and the general somatic symptoms in specific subpopulation of younger age patients, and perhaps via the interplay between BDNF and EPA. Our findings provide promising rationales for future studies to investigate the treatment effects of omega-3 fatty acids on fatigue and somatic symptoms of chronic mental and medical diseases.

The month of walking alone and BDNF level differ between drug-naive first-episode schizophrenia patients and healthy controls.

Schizophrenia is a neurodevelopmental disorder, characterized by impairment in reasoning, affectivity, and social relationships. Previous studies have shown delayed motor development and Brain-Derived Neurotrophic Factor (BDNF) level change in individuals with schizophrenia. We researched the month of walking alone (MWA) and BDNF level between drug-naive first-episode schizophrenia patients (FEP) and healthy control (HC), as well as how they behave in neurocognitive function and severity of symptoms. Predictors of schizophrenia were further explored too. We researched the MWA and BDNF levels between FEP and HCs in the Second Xiangya Hospital of Central South University from August 2017 to January 2020, as well as how they behave in neurocognitive function and the severity of symptoms. A binary logistic regression analysis was used to examine the risk factors affecting the onset and treatment outcome of schizophrenia. We find that FEP showed a walking delay and lower BDNF levels compared to HCs, which were associated with cognitive impairment and severity of symptoms. According to the difference and correlation analysis results, and combined with the appropriate application conditions for binary logistic regression, Wechsler Intelligence Scale Picture completion, Hopkins Verbal Learning Test-Revised, and Trail Making Test: part A were added to the binary logistic regression analysis to distinguish FEP and HCs. Our study has shown delayed motor development and changes in BDNF levels in schizophrenia, extending insight into the early identification of patients with schizophrenia versus healthy populations.

Preliminary study on changes in BDNF in patients with depression after percutaneous coronary intervention

IntroductionDepression and coronary artery disease (CAD) are often comorbid conditions. The presence of depression significantly interferes with the recovery after CAD therapy intervention, such as percutaneous coronary intervention (PCI), one of the most common medical procedures in developed countries. Brain derived neurotrophic factor (BDNF) has a major role in angiogenesis and neuromodulation. Its levels were previously shown to be reduced in patients with depression, and latest studies indicate similar in patients with CAD. However, the correlation of BDNF levels and depression after CAD treatment is unknown.ObjectivesThe aim of this preliminary study is to assess the changes in BDNF levels in patients with depressive symptoms during a six-month period upon PCI.MethodsAntidepressant-free participants that underwent PCI with stent placement due to myocardial infarction or angina pectoris were enrolled in the study. Depressive symptoms were evaluated at baseline using the Beck’s Depression Inventory II (BDI-II) with a cut-off score ≥20 indicating moderate depression. Serum BDNF levels were measured from blood samples drawn a day after (baseline) and six-months upon a successful PCI without complications. The t-test for dependent samples was used with marked significant differences at p&lt;0,05.ResultsAltogether, 76 participants were included in the study, of which 25 finished a six-month follow-up. Participants with BDI-II≥20 at baseline had higher serum BDNF levels in the second measurement (M=23,12, SD=6,20; M=32,02, SD=12,26, respectively). No significant difference was found in serum BDNF levels in measurements between participants with and without depressive symptoms (t=0,33, p=0,74; t=-1,40, p=0,18, respectively). Statistically significant difference was found between serum BDNF in the first and second measurement in the overall sample (t=-2,28, p=0,03) and in participants with baseline moderate depressive symptoms (t=-2,46, p= 0,03), but not in those without (t=-0,59, p=0,57).ConclusionsSerum BDNF levels in participants with baseline moderate depressive symptoms increased after a six-month period upon successful PCI treatment, whereas that trend was not observed in participants without depressive symptoms. This highlights the potential synergistic role of BDNF in comorbid depression and CAD.Disclosure of InterestNone Declared

Longitudinal Changes in BDNF and MMP-9 Protein Plasma Levels in Children after Cochlear Implantation.

Congenitally deaf children who undergo cochlear implantation before 1 year of age develop their auditory skills faster than children who are implanted later. In this longitudinal study, a cohort of 59 implanted children were divided into two subgroups according to their ages at implantation-below or above 1 year old-and the plasma levels of matrix metalloproteinase-9 (MMP-9), brain-derived neurotrophic factor (BDNF), and pro-BDNF were measured at 0, 8, and 18 months after cochlear implant activation, while auditory development was simultaneously evaluated using the LittlEARs Questionnaire (LEAQ). A control group consisted of 49 age-matched healthy children. We identified statistically higher BDNF levels at 0 months and at the 18-month follow-ups in the younger subgroup compared to the older one and lower LEAQ scores at 0 months in the younger subgroup. Between the subgroups, there were significant differences in the changes in BDNF levels from 0 to 8 months and in LEAQ scores from 0 to 18 months. The MMP-9 levels significantly decreased from 0 to 18 months and from 0 to 8 months in both subgroups and from 8 to 18 months only in the older one. For all measured protein concentrations, significant differences were identified between the older study subgroup and the age-matched control group.

Can Brain-derived Neurotrophic Factor (BDNF) Mimetics be a Way Out for Neurodegenerative Diseases?

Neurodegenerative diseases are chronic and progressive disease groups characterized by the decline of neural transmission because of the loss of structure and function of neurons. Although there is currently no effective treatment for neurodegenerative diseases, new treatment strategies need to be developed urgently. Among neurotrophins, BDNF has been extensively investigated, and it has emerged as an important regulator of synaptic plasticity, neuronal survival, and differentiation. Changes in BDNF levels and signaling pathways have been identified in several neurodegenerative diseases. Moreover, promising results have been obtained for BDNF in many experimental studies on animal models. In addition, BDNF serves as a crucial molecular target for developing drugs to treat neurological diseases. However, several pharmacokinetic difficulties have limited its use in clinical practice, such as its inability to cross the blood-brain barrier, short half-life, and potential adverse effects. To avoid these difficulties, several approaches have been explored, but they have led to disappointing results. One way to overcome the limitations of BDNF may be with mimetic molecules that can effectively stimulate the receptors it has an affinity with and thus activates BDNF pathways. In this perspective article, an evaluation of the efficacy of different BDNF mimetics against neurodegenerative diseases was made.

A meta-analysis on the role of brain-derived neurotrophic factor in Parkinson's disease patients.

Brain-derived neurotrophic factor (BDNF) is essential for the development of dopaminergic neurons in the substantia nigra. To investigate the level of BDNF among Parkinson's disease (PD) subjects and the influence of depression on BDNF levels. A total of 1920 subjects were included in the analysis; of these, 1034 had PD and 886 were healthy controls. A thorough literature search up to May 2022 was conducted. The mean difference (MD) of BDNF levels and 95% confidence intervals (95% CIs) were calculated with random or fixed effects models. Compared to healthy controls, levels of BDNF were significantly lower in patients with PD (MD = -1.60, 95% CI (-2.49, -0.70), p < 0.001). Patients with PD and depression had significantly lower levels of BDNF (MD = -3.39, 95% CI (-5.55, -1.23), p = 0.002), as well as those with PD without depression (MD = -0.80, 95% CI (-1.56, -0.03), p = 0.04). However, there was no discernible change in BDNF levels (MD = -0.82, 95% CI (1.75, 0.10), p = 0.08) between the participants with PD and depression compared to the PD patients alone. Compared with healthy controls, BDNF levels were significantly lower in the subjects with PD combined with depression, and PD without depression. However, there was no discernible difference in BDNF levels between subjects with PD with depression compared to those with PD without depression.

Impact of genetic deletion of MrgD or Mas receptors in depressive-like behaviour in mice.

To evaluate the impact of genetic deletion of receptors of the counterregulatory arms of the renin-angiotensin system in depressive-like behaviours. 8-12 weeks-old male mice wild type (WT, C57BL/6J) and mice with genetic deletion of MrgD (MrgD KO) or Mas receptors (Mas KO) were subjected to the Forced Swim Test (FST) and the Tail Suspension Test (TST). Brain-derived neurotrophic factor (BDNF) levels were measured by enzyme-linked immunosorbent assay (ELISA). Blockade of Mas was performed by acute intracerebroventricular (icv) injection of its selective antagonist, A779. No statistical difference in immobility time was observed between MrgD KO and WT male animals subjected to FST and TST. However, acute icv injection of A779 significantly increased the immobility time of MrgD KO male mice subjected to FST and TST, suggesting the involvement of Mas in preventing depressive-like behaviour. Indeed, Mas KO male animals showed increased immobility time in FST and TST, evidencing a depressive-like behaviour in these animals, in addition to a reduction in BDNF levels in the prefrontal cortex and hippocampus. No changes in BDNF levels were observed in MrgD KO male animals. Our data showed that Mas plays an important role in the neurobiology of depression probably by modulating BDNF expression. On the contrary, lack of MrgD did not alter depressive-like behaviour, which was supported by the lack of alterations in BDNF levels.

Blood-based biomarkers of antidepressant response to ketamine and esketamine: A systematic review and meta-analysis.

(R,S)-ketamine (ketamine) and its enantiomer (S)-ketamine (esketamine) can produce rapid and substantial antidepressant effects. However, individual response to ketamine/esketamine is variable, and there are no well-accepted methods to differentiate persons who are more likely to benefit. Numerous potential peripheral biomarkers have been reported, but their current utility is unclear. We conducted a systematic review/meta-analysis examining the association between baseline levels and longitudinal changes in blood-based biomarkers, and response to ketamine/esketamine. Of the 5611 citations identified, 56 manuscripts were included (N = 2801 participants), and 26 were compatible with meta-analytical calculations. Random-effect models were used, and effect sizes were reported as standardized mean differences (SMD). Our assessments revealed that more than 460 individual biomarkers were examined. Frequently studied groups included neurotrophic factors (n = 15), levels of ketamine and ketamine metabolites (n = 13), and inflammatory markers (n = 12). There were no consistent associations between baseline levels of blood-based biomarkers, and response to ketamine. However, in a longitudinal analysis, ketamine responders had statistically significant increases in brain-derived neurotrophicfactor (BDNF) when compared to pre-treatment levels (SMD [95% CI] = 0.26 [0.03, 0.48], p = 0.02), whereas non-responders showed no significant changes in BDNF levels (SMD [95% CI] = 0.05 [-0.19, 0.28], p = 0.70). There was no consistent evidence to support any additional longitudinal biomarkers. Findings were inconclusive for esketamine due to the small number of studies (n = 2). Despite a diverse and substantial literature, there is limited evidence that blood-based biomarkers are associated with response to ketamine, and no current evidence of clinical utility.

Recent Advances on the Role of Brain-Derived Neurotrophic Factor (BDNF) in Neurodegenerative Diseases.

Neurotrophins, such as brain-derived neurotrophic factor (BDNF), are essential for neuronal survival and growth. The signaling cascades initiated by BDNF and its receptor are the key regulators of synaptic plasticity, which plays important role in learning and memory formation. Changes in BDNF levels and signaling pathways have been identified in several neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease, and Huntington’s disease, and have been linked with the symptoms and course of these diseases. This review summarizes the current understanding of the role of BDNF in several neurodegenerative diseases, as well as the underlying molecular mechanism. The therapeutic potential of BDNF treatment is also discussed, in the hope of discovering new avenues for the treatment of neurodegenerative diseases.

Effects of Aerobic Training on Brain Plasticity in Patients with Mild Cognitive Impairment: A Systematic Review of Randomized Controlled Trials.

The purpose of this study was to systematically review to find if aerobic exercise compared to no exercise or any other intervention affects brain plasticity among people with mild cognitive impairment (MCI). Searches were conducted in the Scopus, SciELO, PubMed, Web of Science, Science Direct, and Google Scholar databases. The included studies were randomized control trials (RCTs) written in English comprising individuals with MCI that evaluated the effects of aerobic training on brain-derived neurotrophic factor (BDNF), brain structures, or brain activity. The quality of trials was evaluated using the PEDro scale for RCTs. Twelve studies with medium to high quality were included, of which five studies focused on brain-derived neurotrophic factor (four articles reported elevation and one article reported no changes in BDNF levels following the aerobic exercise), two studies focused on brain structures (both reported increases in hippocampus volume following the aerobic exercise), and five studies focused on brain activity (four articles reported positive changes, and one article reported no changes in brain activity following the aerobic exercise). Research regarding the effects of aerobic training on brain plasticity in people with MCI is in its infancy. Still, aerobic exercise seems to be a promising therapy in people with MCI.

Impact of fasting on stress systems and depressive symptoms in patients with major depressive disorder: a cross-sectional study

Major depressive disorder (MDD) is frequently associated with poor response to treatment. Common antidepressants target neurotransmission and neuronal plasticity, which require adequate energy supply. As imaging studies indicate disturbances in central energy metabolism, and caloric restriction improves neuroplasticity and impacts mood and cognition, correction of energy status might increase the effectiveness of antidepressant treatments and reduce the psychopathological symptoms of depression. Metabolic parameters, stress hormones, and brain-derived neurotrophic factor (BDNF) levels were assessed in serum of depressed inpatients (MDD, N = 21) and healthy volunteers (Ctrl, N = 28) before and after a 72 h fasting period during which only water was consumed. Depression severity was assessed by Beck’s Depression Inventory (BDI)-2 sum-score and cognitive-affective and somatic sub-scores. Fasting similarly impacted metabolic parameters and stress systems in both groups. Fasting elevated BDI-2 sum-scores and somatic sub-scores in Ctrl. In MDD, fasting increased somatic-, but decreased cognitive-affective symptoms. Sub-group analyses based on BDI-2 sum-scores pre-fasting showed that cognitive-affective symptoms decreased in patients with moderate/severe but not in those with mild symptoms. This was associated with differential changes in BDNF levels. In conclusion, fasting improved cognitive-affective sub-scores in MDD patients with moderate/severe symptoms that had not responded to prior therapy. Interventions that modulate energy metabolism might directly improve cognitive-affective symptoms and/or augment therapeutic efficacy in moderate-to-severely depressed patients.

Peripheral Blood Levels of Brain-Derived Neurotrophic Factor in Patients with First Episode Psychosis: A Systematic Review and Meta-Analysis.

Background: Peripheral blood level of brain-derived neurotrophic factor (BDNF) may be used as a diagnostic and/or prognostic marker for schizophrenia. Previous studies were inconsistent. A systematic review was conducted to examine whether BDNF level is different in patients with first episode psychosis (FEP) compared to health controls (HC) and whether it changes after treatment. Methods: Literature search was done in PubMed, Web of Science, and Google Scholar following standard procedures. Hedges’ g was used as the measure of effect size (ES), which was pooled with random effects model. Publication bias and moderator effects were examined. Results: Search yielded 29 studies with a total sample size of 2912. First meta-analysis included 27 studies with FEP vs. HC comparison. Pooled ES was −0.63, p < 0.001, indicating that BDNF level was lower in FEP than in HC. Studies were heterogeneous, and moderator analysis showed that studies of younger patient, higher symptom severity, and more drug naïve had larger ES. Second meta-analysis examined change in BDNF levels before and after antipsychotic treatment in eight studies. A pooled ES of −0.003 (p = 0.96) showed no change in peripheral BDNF level after treatment. Conclusion: Peripheral BDNF level was decreased in FEP compared to HC, but it did not change after treatment.

Time Course and Role of Exercise-Induced Cytokines in Muscle Damage and Repair After a Marathon Race.

Endurance exercise induces an increase in the expression of exercise-induced peptides that participate in the repair and regeneration of skeletal muscles. The present study aimed to evaluate the time course and role of exercise-induced cytokines in muscle damage and repair after a marathon race. Fifty-seven Brazilian male amateur marathon finishers, aged 30–55 years, participated in this study. The blood samples were collected 24 h before, immediately after, and 24 and 72 h after the São Paulo International Marathon. The leukogram and muscle damage markers were analyzed using routine automated methodology in the clinical laboratory. The plasma levels of the exercise-induced cytokines were determined using the Human Magnetic Bead Panel or enzyme-linked immunosorbent assays [decorin and growth differentiation factor 15 (GDF-15)]. A muscle damage was characterized by an increase in plasma myocellular proteins and immune changes (leukocytosis and neutrophilia). Running the marathon increased interleukin (IL)-6 (4-fold), IL-8 (1.5-fold), monocyte chemoattractant protein-1 (2.4-fold), tumor necrosis factor alpha (TNF-α) (1.5-fold), IL-10 (11-fold), decorin (1.9-fold), GDF-15 (1.8-fold), brain-derived neurotrophic factor (BDNF) (2.7-fold), follistatin (2-fold), and fibroblast growth factor (FGF-21) (3.4-fold) plasma levels. We also observed a reduction in musclin, myostatin, IL-15, and apelin levels immediately after the race (by 22–36%), 24 h (by 26–52%), and 72 h after the race (by 25–53%). The changes in BDNF levels were negatively correlated with the variations in troponin levels (r = −0.36). The variations in IL-6 concentrations were correlated with the changes in follistatin (r = 0.33) and FGF-21 (r = 0.31) levels after the race and with myostatin and irisin levels 72 h after the race. The changes in IL-8 and IL-10 levels had positive correlation with variation in musclin (p < 0.05). Regeneration of exercise-induced muscle damage involves the participation of classical inflammatory mediators, as well as GDF-15, BDNF, follistatin, decorin, and FGF-21, whose functions include myogenesis, mytophagia, satellite cell activation, and downregulation of protein degradation. The skeletal muscle damage markers were not associated to myokines response. However, BDNF had a negative correlation with a myocardial damage marker. The classical anti-inflammatory mediators (IL-10, IL-8, and IL-6) induced by exercise are associated to myokines response immediately after the race and in the recovery period and may affect the dynamics of muscle tissue repair.

Association between the improvement in depressive symptoms and serum BDNF levels in drug-naive first episode patients with schizophrenia: A longitudinal follow-up

Depressive symptoms are frequent clinical manifestations in patients with schizophrenia. Decreased brain-derived neurotrophic factor (BDNF) has been shown to be involved in the development of depressive symptoms. However, the detailed molecular mechanism of BDNF in the depressive symptoms of schizophrenia patients remains to be fully elucidated. This study aimed to investigate the role of BDNF in the depressive symptoms in drug-naïve first-episode (DNFE) patients with schizophrenia and whether BDNF levels were associated with the improvement of depressive symptoms after olanzapine treatment. 50 DNFE schizophrenia patients and 55 healthy controls were recruited, and their serum BDNF levels were compared. All patients were treated with olanzapine monotherapy for 12 weeks, and 45 patients completed the trial. The serum BDNF levels and depressive symptoms were measured again at follow-up. We found that DNFE patients had lower BDNF levels, compared to controls. Last observation carried forward (LOCF) analysis was used for patients who dropped out after the second month, and 50 patients were included in the statistical analysis with LOCF. After 12 weeks of treatment with olanzapine, BDNF levels were significantly increased and depressive symptoms were significantly decreased. Correlation analysis showed that the change of BDNF levels after treatment was correlated with the change of HAMD total score from baseline. Further regression analysis showed that the change in BDNF levels was an independent predictor for the improvement in depressive symptoms, after controlling age, BMI change and the decrease of PANSS total score. However, the baseline BDNF levels were not associated with an improvement in depressive symptoms in patients. Our findings reveal that olanzapine treatment can increase BDNF levels and improve depressive symptoms in schizophrenia patients. Moreover, the changes in serum BDNF levels were related to the improvement in depressive symptoms.