First evidence for glial pathology in late life minor depression: S100B is increased in males with minor depression

S100B Serum Levels in Chronic Heart Failure Patients: A Multifaceted Biomarker Linking Cardiac and Cognitive Dysfunction

S100 calcium-binding protein B (S100B) is a protein primarily known as a biomarker for central nervous system (CNS) injuries, reflecting blood-brain barrier (BBB) permeability and dysfunction. Recently, S100B has also been implicated in cardiovascular diseases, including heart failure (HF). Thus, we investigated serum levels of S100B in 146 chronic HF patients from the Cognition.Matters-HF study and their association with cardiac and cognitive dysfunction. The median S100B level was 33 pg/mL (IQR: 22-47 pg/mL). Higher S100B levels were linked to longer HF duration (p = 0.014) and increased left atrial volume index (p = 0.041), but also with a higher prevalence of mild cognitive impairment (p = 0.023) and lower visual/verbal memory scores (p = 0.006). In a multivariable model, NT-proBNP levels independently predicted S100B (T-value = 2.27, p = 0.026). S100B did not impact mortality (univariable HR (95% CI) 1.00 (0.99-1.01); p = 0.517; multivariable HR (95% CI) 1.01 (1.00-1.03); p = 0.142), likely due to its reflection of acute injury rather than long-term outcomes and the mild HF phenotype in our cohort. These findings underscore S100B's value in comprehensive disease assessment, reflecting both cardiac dysfunction and potentially related BBB disruption.

Increased Serum NSE and S100B Indicate Neuronal and Glial Alterations in Subjects Under 71 Years With Mild Neurocognitive Disorder/Mild Cognitive Impairment

Background

Mild cognitive impairment (MCI) is considered a pre-stage of different dementia syndromes. Despite diagnostic criteria refined by DSM-5 and a new term for MCI – “mild neurocognitive disorder” (mild NCD) – this diagnosis is still based on clinical criteria.

Methods

To link mild NCD to the underlying pathophysiology we assessed the degree of white matter hyperintensities (WMH) in the brain and peripheral biomarkers for neuronal integrity (neuron-specific enolase, NSE), plasticity (brain-derived neurotrophic factor, BDNF), and glial function (S100B) in 158 community-dwelling subjects with mild NCD and 82 healthy controls. All participants (63–79 years old) were selected from the Leipzig-population-based study of adults (LIFE).

Results

Serum S100B levels were increased in mild NCD in comparison to controls (p = 0.007). Serum NSE levels were also increased but remained non-significant after Bonferroni-Holm correction (p = 0.04). Furthermore, age by group interaction was significant for S100B. In an age-stratified sub-analysis, NSE and S100B were higher in younger subjects with mild NCD below 71 years of age. Some effects were inconsistent after controlling for potentially confounding factors. The discriminatory power of the two biomarkers NSE and S100B was insufficient to establish a pathologic threshold for mild NCD. In subjects with mild NCD, WMH load correlated with serum NSE levels (r = 0.20, p = 0.01), independently of age.

Conclusion

Our findings might indicate the presence of neuronal (NSE) and glial (S100B) injury in mild NCD. Future studies need to investigate whether younger subjects with mild NCD with increased biomarker levels are at risk of developing major NCD.

Association of peripheral manifestation of brain-derived neurotrophic factor with depression: A meta-analysis

BACKGROUND

The relationship between brain-derived neurotrophic factor (BDNF) and depression is a hot topic in research as several results of preclinical and clinical studies have shown controversial results. Our meta-analysis aims to evaluate and update the current status of peripheral BDNF with depression.

METHODS

We performed a meta-analysis by comprehensively searching PubMed and Web of Science for English-language literature from inception to 1st of June 2020. The search terms included brain-derived neurotrophic factor or BDNF in combination with depression, without year restriction. Using STATA software, data were pooled using a random-effects model.

RESULTS

In our literature search, 24 studies involving 1130 depressed patients and 1378 healthy individuals met our inclusion criteria. The results of our meta-analysis showed that the peripheral levels of BDNF levels significantly decreased in depression than nondepressed healthy controls (SMD = -0.89, 95% CI = -1.41, -0.38, p < .0001); however, the significant heterogeneity among studies (Q = 740.91, I²  = 96.8; p < .001) was discovered. Trim-and-fill estimations for the adjustment of publication bias indicated that publication bias had no impact on our results. Our sub-group analysis showed that a history of depression and alcohol consumption had an effect on the level of BDNF. In addition, age and gender did not affect the heterogeneity of BDNF in the meta-analysis.

CONCLUSIONS

Although decreased peripheral expression of BDNF certainly presents a risk of depression, we cannot find a definite relationship between the peripheral level of BDNF with depression to use BDNF as a reliable biomarker to assess the depression in clinical practice. We propose that future research should consider all the factors affecting BDNF and assess the level of proBDNF and mBDNF separately while evaluating the patients with depression objectively.

Evaluation of serum neurofilament light in the early management of mTBI patients

OBJECTIVES

Serum S100B allows a one-third reduction of computed tomography (CT) scans performed for mild traumatic brain injury (mTBI) patients. In this study, we evaluated the diagnostic performance of serum NF-L in the detection of intracranial lesions induced by mTBI.

METHODS

One hundred seventy-nine adult mTBI patients presenting to the emergency department of Clermont-Ferrand University Hospital with a Glasgow Coma Scale (GCS) score of 14-15 were included. S100B assays were performed for clinical routine while NF-L samples were stored at -80 °C until analysis. CT scans were performed for patients with S100B levels above the decision threshold of 0.10 μg/L. Later, NF-L and S100B levels were compared to CT scan findings to evaluate the biomarkers' performances.

RESULTS

The area under the ROC curve (AUC) evaluating the diagnostic ability in the prediction of intracranial lesions was 0.72 (95% CI; 0.58-0.87) for S100B and 0.58 (95% CI; 0.45-0.71) for NF-L, the specificities (at a threshold allowing a 100% sensitivity) were 35.7% for S100B, and 28% for NF-L (p=0.096). AUCs of NF-L and S100B for the identification of patients with neurological disorders were statistically different (p<0.001). The AUCs were 0.87 (95% CI; 0.82-0.93) for NF-L and 0.57 (95% CI; 0.48-0.66) for S100B. There was a poor correlation between NF-L and S100B, and NF-L levels were correlated to patients' age (Spearman coefficient of 0.79).

CONCLUSIONS

NF-L showed poor performances in the early management of mTBI patients. NF-L levels are strongly correlated to neurodegeneration, whether physiological, age-related, or pathological.

Beyond the neuron: Role of non-neuronal cells in stress disorders

Stress disorders are leading causes of disease burden in the U.S. and worldwide, yet available therapies are fully effective in less than half of all individuals with these disorders. Although to date, much of the focus has been on neuron-intrinsic mechanisms, emerging evidence suggests that chronic stress can affect a wide range of cell types in the brain and periphery, which are linked to maladaptive behavioral outcomes. Here, we synthesize emerging literature and discuss mechanisms of how non-neuronal cells in limbic regions of brain interface at synapses, the neurovascular unit, and other sites of intercellular communication to mediate the deleterious, or adaptive (i.e., pro-resilient), effects of chronic stress in rodent models and in human stress-related disorders. We believe that such an approach may one day allow us to adopt a holistic "whole body" approach to stress disorder research, which could lead to more precise diagnostic tests and personalized treatment strategies. Stress is a major risk factor for many psychiatric disorders. Cathomas et al. review new insight into how non-neuronal cells mediate the deleterious effects, as well as the adaptive, protective effects, of stress in rodent models and human stress-related disorders.

Sex differences in the blood-brain barrier: Implications for mental health

Prevalence of mental disorders, including major depressive disorder (MDD), bipolar disorder (BD) and schizophrenia (SZ) are increasing at alarming rates in our societies. Growing evidence points toward major sex differences in these conditions, and high rates of treatment resistance support the need to consider novel biological mechanisms outside of neuronal function to gain mechanistic insights that could lead to innovative therapies. Blood-brain barrier alterations have been reported in MDD, BD and SZ. Here, we provide an overview of sex-specific immune, endocrine, vascular and transcriptional-mediated changes that could affect neurovascular integrity and possibly contribute to the pathogenesis of mental disorders. We also identify pitfalls in current literature and highlight promising vascular biomarkers. Better understanding of how these adaptations can contribute to mental health status is essential not only in the context of MDD, BD and SZ but also cardiovascular diseases and stroke which are associated with higher prevalence of these conditions.

Mapping of predictors of the disengagement of the descending inhibitory pain modulation system in fibromyalgia: an exploratory study

BACKGROUND

The main symptoms of fibromyalgia comprise diffuse pain, disability, depressive symptoms, catastrophizing, sleep disruption and fatigue, associated with dysfunction of the descending pain-modulating system (DPMS).

OBJECTIVES

We aimed to identify patterns of main symptoms of fibromyalgia and neuroplasticity biomarkers (i.e. brain-derived neurotrophic factor (BDNF) and S100B protein) in non-responders to the conditioned pain modulation task (CPM-task) induced by immersion of hand in cold water (0-1°C). Furthermore, we evaluated if these patterns predict responsiveness to CPM-task.

METHODS

This cross-sectional study included 117 women with fibromyalgia ((n = 60) non-responders and (n = 57) responders), with age ranging from 30 to 65 years old. We analysed changes in numerical pain scale (NPS-10) during the CPM-task using a standardized protocol.

RESULTS

A hierarchical multivariate logistic regression analysis was used to construct a propensity score-adjusted index to identify non-responders compared to responders to CPM-task. The following variables were retained in the models: analgesic use four or more times per week, heat pain threshold (HPT), poor sleep quality, pain catastrophizing, serum levels of BDNF, number of psychiatric diagnoses and the impact of symptoms of fibromyalgia on quality of life. Receiver operator characteristics (ROC) analysis showed non-responders can be discriminated from responders by a composite index of more frequent symptoms of fibromyalgia and neuroplasticity markers (area under the curve (AUC) = 0.83, sensitivity = 100% and specificity = 98%).

CONCLUSION

Patterns of fibromyalgia symptoms and neuroplasticity markers may be helpful to predict responsiveness to the CPM-task which might help personalize treatment and thereby contribute to the care of patients with fibromyalgia.

Serum BDNF levels correlate with regional cortical thickness in minor depression: a pilot study

Serum brain-derived neurotrophic factor (BDNF) reflects state changes in mood disorders. But its relation to brain changes in depression has rarely been investigated in humans. We assessed the association between serum BDNF, cortical thickness, or gray matter volume in 20 subjects with a minor depressive episode and 40 matched healthy subjects. Serum BDNF positively correlated with cortical thickness and volume in multiple brain regions in the minor depression group: the bilateral medial orbitofrontal cortex and rostral anterior cingulate cortex, left insula, and cingulum, right superior frontal gyrus, and other regions—regions typically affected by major depression. Interestingly, these correlations were driven by subjects with first episode depression. There was no significant association between these imaging parameters and serum BDNF in the healthy control group. Interaction analyses supported this finding. Our findings point to a specific association between serum BDNF and magnetic resonance imaging parameters in first-episode minor depression in a region- and condition-dependent manner. A positive correlation between serum BDNF and structural gray matter estimates was most consistently observed for cortical thickness. We discuss why cortical thickness should be preferred to volumetric estimates for such analyses in future studies. Results of our pilot study have to be proven in future larger-scale studies yielding higher statistical power.

Higher S100B Levels Predict Persistently Elevated Anhedonia with Escitalopram Monotherapy Versus Antidepressant Combinations: Findings from CO-MED Trial

BACKGROUND

Elevated S100 calcium binding protein B (S100B) levels in systemic circulation may induce neuroinflammation and reflect greater blood-brain barrier (BBB) dysfunction. Neuroinflammation in patients with major depressive disorder (MDD), in turn, may reduce likelihood of improvement with serotonergic antidepressants.

METHODS

Levels of S100B were measured in plasma samples obtained prior to initiation of treatment with bupropion-plus-escitalopram, escitalopram-plus-placebo, or venlafaxine-plus-mirtazapine in participants of Combining Medications to Enhance Depression Outcomes trial (n = 153). Depression severity was measured with 16-item Quick Inventory of Depressive Symptomatology Self-Report and anhedonia was measured with 3 items of 30-item Inventory of Depressive Symptomatology. Differential changes in depression severity and anhedonia over acute-phase (baseline, weeks 1, 2, 4, 6, 8, 10, and 12) in the three treatment arms were tested with logS100B-by-treatment-arm interaction in mixed model analyses after controlling for age, gender, and body mass index.

RESULTS

There was a significant logS100B-by-treatment-arm interaction for anhedonia (F = 3.21; df = 2, 142; p = 0.04) but not for overall depression severity (F = 1.99; df = 2, 142; p = 0.14). Higher logS100B levels were associated with smaller reductions in anhedonia (effect size = 0.67, p = 0.047) in escitalopram monotherapy but not in the other two arms. Correlation coefficients of anhedonia severity averaged over acute-phase (including baseline) with baseline S100B levels were 0.57, -0.19, and 0.22 for escitalopram monotherapy, bupropion-plus-escitalopram and venlafaxine-plus-mirtazapine arms respectively.

CONCLUSION

Higher baseline S100B levels in depressed patients resulted in poorer response to escitalopram monotherapy. Addition of bupropion, a dopaminergic antidepressant, partially mitigated this effect.

Does S100B have a potential role in affective disorders? A literature review

BACKGROUND

S100B is a calcium-binding protein located in glial cells; it is regarded as a potential biomarker in affective disorders.

AIM

To review the literature investigating the role of S100B in patients with affective disorders.

METHOD

A systematic review of original English language studies investigating S100B in serum, cerebrospinal fluid, plasma and lymphocytes, in patients with affective disorders, was conducted. The literature search was conducted within the PubMed database. Effect sizes were calculated to adjust for systematic measurement effects.

RESULTS

Twenty studies were included, with a total of 1292 participants. Of these, 398 patients had or have had depressive disorder, 301 patients had bipolar disorder and 593 were healthy controls. S100B levels in serum were consistently elevated in studies with statistically significant results which investigated acute affective episodes (comprising major depressive episode in major depressive disorder, and both manic and depressive episodes in patients with bipolar disorder), in comparison to healthy controls. There were few studies assessing S100B levels in cerebrospinal fluid, plasma or lymphocytes, and these had inconsistent results.

CONCLUSION

The results indicated that elevated S100B levels might be associated with mood episodes in affective disorders. However, the role of S100B, and its possible impact in affective disorders, requires further investigation and at the present S100B does not have a role as clinically biomarker in affective disorder. Future longitudinal multicentre studies with larger transdiagnostic real life patient cohorts are warranted.

Longitudinal serum S100β and brain aging in the Lothian Birth Cohort 1936

Elevated serum and cerebrospinal fluid concentrations of S100β, a protein predominantly found in glia, are associated with intracranial injury and neurodegeneration, although concentrations are also influenced by several other factors. The longitudinal association between serum S100β concentrations and brain health in nonpathological aging is unknown. In a large group (baseline N = 593; longitudinal N = 414) of community-dwelling older adults at ages 73 and 76 years, we examined cross-sectional and parallel longitudinal changes between serum S100β and brain MRI parameters: white matter hyperintensities, perivascular space visibility, white matter fractional anisotropy and mean diffusivity (MD), global atrophy, and gray matter volume. Using bivariate change score structural equation models, correcting for age, sex, diabetes, and hypertension, higher S100β was cross-sectionally associated with poorer general fractional anisotropy (r = -0.150, p = 0.001), which was strongest in the anterior thalamic (r = -0.155, p < 0.001) and cingulum bundles (r = -0.111, p = 0.005), and survived false discovery rate correction. Longitudinally, there were no significant associations between changes in brain imaging parameters and S100β after false discovery rate correction. These data provide some weak evidence that S100β may be an informative biomarker of brain white matter aging.

Effects of glucocorticoids in depression: Role of astrocytes

Astrocytes or astroglia are heterogeneous cells, similar to neurons, that have different properties in different brain regions. The implications of steroid hormones on glial cells and stress-related pathologies have been studied previously. Glucocorticoids (GCs) that are released in response to stress have been shown to be deleterious to neurons in various brain regions. Further, in the light of the effect of GCs on astrocytes, several reports have shown the crucial role of glia. Still, much remains to be done to understand the stress-astrocytes-glucocorticoid interactions associated with the pathological consequences of various CNS disorders. This review is an attempt to summarize the effects of GCs and stress on astrocytes and its implications in depression.

S100B, Homocysteine, Vitamin B12, Folic Acid, and Procalcitonin Serum Levels in Remitters to Electroconvulsive Therapy: A Pilot Study

Background

Electroconvulsive therapy (ECT) is one of the most effective treatment options for refractory depressed patients. To date, there are only a few predictors of response.

Aim

The aim was to identify predictive biomarkers of remission to ECT on a molecular level.

Methods

11 patients suffering from a major depressive episode—according to the Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV)—underwent 10 ECT sessions. Blood samples were taken, and the depression severity was assessed before, one hour and 24 hours after sessions 1, 4, 7, and 10 using the Montgomery Asberg Depression Rating Scale (MADRS). A MADRS total score < 12 was interpreted as remission.

Results

Patients remitting under ECT had significantly higher homocysteine (p < 0.001), S100B (p < 0.001), and procalcitonin (PCT) (p = 0.027) serum levels. On the contrary, serum levels of vitamin B12 (p < 0.001) and folic acid (p = 0.007) were significantly lower in remitters compared to those in nonremitters. Levels remained unchanged throughout the whole ECT course.

Conclusions

Our findings indicate that lower levels of vitamin B12 and folic acid associated with higher levels of homocysteine, S100B, and PCT point to a subgroup of depressed patients sensitive to ECT. Due to the limited sample size, further studies are required to replicate our findings.

S100B Levels in Patients with Type 2 Diabetes Mellitus and Co-Occurring Depressive Symptoms

Depression is a comorbid condition in patients with Type 2 Diabetes mellitus (T2DM). S100B, a glia derived protein, is linked to depression and has been suggested as a biomarker for depression outcomes in several populations. However, to date there is no data about S100B levels and depression in patients with T2DM. Objective. We hypothesized that S100B serum levels are increased in patients with T2DM and recently diagnosed, drug-free depressive symptoms, and could be used for the diagnosis of depression in T2DM. Methods. Overall 52 patients (62 ± 12 years, female 66, 7%) with no history of depression deriving from the Diabetes out-patient clinic of our University Hospital underwent a one-to-one interview with a psychiatrist and filled a self-assessment (Zung) questionnaire. Serum S00B levels were compared between 30 (63±12 years, female 66, 7%) diabetic patients without depressive symptoms vs 22 patients (62 ±12 years, female 68, 2%) with T2DM and depressive symptoms. Results. There was no difference in serum levels of S100B between patients with T2DM without depressive symptoms vs diabetic patients suffering from depressive symptoms (2.1 (1.9-10.9) pg/ml vs 2.4 (1.9-14.8) pg/ml, p=0. 637+). Moreover, linear regression analysis did not show any association between lnS100B levels and depressive symptoms (β = 0.084, 95% CI 0.470-0.871, and p=0.552), Zung self-assessment score (β = 0.048, 95% CI -0.024-0.033, and p=0.738), and other patients' characteristics. Conclusions. In patients with T2DM there is no correlation between S100B serum levels and newly detected mild depressive symptoms. The brain biochemistry pathways of depression in T2DM warrant further investigation in a larger scale population.

Venlafaxine ameliorates the depression-like behaviors and hippocampal S100B expression in a rat depression model

Background

Accumulating evidence has indicated that S100B may be involved in the pathophysiology of depression. No published study has examined the effect of the antidepressant drug venlafaxine on S100B in animal models of depression. This study investigated S100B expression in the hippocampus and assessed the effect of venlafaxine on S100B mRNA level and protein expression in rats exposed to chronic unpredictable mild stress (CUMS).

Methods

Forty Sprague-Dawley rats were randomly divided into four groups as control, 0, 5 and 10 mg venlafaxine groups. The venlafaxine groups were exposed to CUMS from day 2 to day 43. Venlafaxine 0, 5 and 10 mg/kg were then administered from day 23 to day 43. We performed behavioral assessments with weight change, open-field and sucrose preference, and analyzed S100B protein expression and mRNA level in the hippocampus.

Results

The CUMS led to a decrease in body weight, locomotor activity and sucrose consumption, but venlafaxine treatment (10 mg) reversed these CUMS-induced decreases Also, CUMS increased S100B protein expression and mRNA level in the hippocampus, but venlafaxine treatment (10 mg) significantly decreased S100B protein expression and mRNA level, which were significantly lower than the other treatment groups, without significant difference between the 10 mg venlafaxine and the control groups.

Conclusions

Our findings showed that venlafaxine treatment (10 mg) may improve the depression-like behaviors and decrease over-expression of S100B protein and mRNA in the hippocampus in a rat model of depression.

Electronic supplementary material

The online version of this article (doi:10.1186/s12993-016-0116-x) contains supplementary material, which is available to authorized users.

Plasma Brain-Derived Neurotrophic Factor as a Biomarker for the Main Types of Mild Neurocognitive Disorders and Treatment Efficacy: A Preliminary Study

Decreased levels of brain-derived neurotrophic factor (BDNF) are assumed to play a crucial role in the pathophysiology of mild neurocognitive disorders (MNCDs). In this study, we compared plasma BDNF levels (at baseline and after two months of treatment with escitalopram) in patients with the main types of MNCDs and normal controls. 21 patients met the DSM-5 diagnostic criteria for possible MNCD due to Alzheimer's disease (MNCD-AD); 22 patients fulfilled the diagnostic criteria for subcortical vascular MNCD (ScVMNCD) according to Frisoni et al. (2002) and neuroimaging-supported probable diagnosis of vascular MNCD according to DSM-5; 16 subjects entered control group. At baseline, we detected lower BDNF levels in both MNCD groups, which was significant only in subjects with MNCD-AD. Moreover, plasma BDNF level of 21160 pg/mL showed high sensitivity (94%) to discriminate patients with MNCD-AD. Decreased plasma BDNF highly correlated with the severity of memory impairment and total MMSE score in MNCD-AD group. Escitalopram treatment in patients with MNCD-AD or ScVMNCD led to an increase of plasma BDNF concentrations and as a result to a decrease of cognitive, depressive, and anxiety symptom severity. In conclusion, plasma BDNF might be a reliable biomarker for the validation of MNCD-AD diagnosis and treatment efficacy.