Cortisol, cytokines, and hippocampal volume interactions in the elderly

Neuroinflammation, cerebrovascular dysfunction and diurnal cortisol biomarkers in a memory clinic cohort: Findings from the Co-STAR study

Cortisol dysregulation, neuroinflammation, and cerebrovascular dysfunction are biological processes that have been separately shown to be affected in Alzheimer's disease (AD). Here, we aimed to identify biomarker signatures reflecting these pathways in 108 memory clinic patients with subjective cognitive decline (SCD, N = 40), mild cognitive impairment (MCI, N = 39), and AD (N = 29). Participants were from the well-characterized Cortisol and Stress in Alzheimer's Disease (Co-STAR) cohort, recruited at Karolinska University Hospital. Salivary diurnal cortisol measures and 41 CSF proteins were analyzed. Principal component analysis was applied to identify combined biosignatures related to AD pathology, synaptic loss, and neuropsychological assessments, in linear regressions adjusted for confounders, such as age, sex, education and diagnosis. We found increased CSF levels of C-reactive protein (CRP), interferon γ-inducible protein (IP-10), thymus and activation-regulated chemokine (TARC), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) in MCI patients. Further, markers of cortisol dysregulation (flattened salivary cortisol awakening response and flattened cortisol slope) correlated with increased levels of placental growth factor (PlGF), IP-10, and chitinase 3-like 1 (YKL-40) in the total cohort. A biosignature composed of cortisol awakening response, cortisol slope, and CSF IL-6 was downregulated in AD patients. Moreover, biomarker signatures reflecting overlapping pathophysiological processes of neuroinflammation and vascular injury were associated with AD pathology, synaptic loss, and worsened processing speed. Our findings suggest an early dysregulation of immune and cerebrovascular processes during the MCI stage and provide insights into the interrelationship of chronic stress and neuroinflammation in AD.

Relationships among tumor necrosis factor-alpha levels, beta-amyloid accumulation, and hippocampal atrophy in patients with late-life major depressive disorder

BACKGROUND

Major depressive disorder (MDD) is characterized by hippocampal volume reduction, impacting cognitive function. Inflammation, particularly elevated tumor necrosis factor-alpha (TNF-α) levels, is consistently implicated in MDD pathophysiology. This study investigates the relationships between TNF-α levels, hippocampal volume, beta-amyloid (Aβ) burden, and cognitive abilities in MDD patients, aiming to illuminate the complex interplay among inflammatory markers, pathology indicators, structural brain alterations, and cognitive performance in non-demented MDD individuals.

METHOD

Fifty-two non-demented MDD patients, comprising 25 with mild cognitive impairment (MCI), were recruited along with 10 control subjects. Each participant underwent a thorough assessment encompassing TNF-α blood testing, 18F-florbetapir positron emission tomography, magnetic resonance imaging scans, and neuropsychological testing. Statistical analyses, adjusted for age and education, were performed to investigate the associations between TNF-α levels, adjusted hippocampal volume (HVa), global Aβ burden, and cognitive performance.

RESULTS

MCI MDD patients displayed elevated TNF-α levels and reduced HVa relative to controls. Correlation analyses demonstrated inverse relationships between TNF-α level and HVa in MCI MDD, all MDD, and all subjects groups. Both TNF-α level and HVa exhibited significant correlations with processing speed across all MDD and all subjects. Notably, global 18F-florbetapir standardized uptake value ratio did not exhibit significant correlations with TNF-α level, HVa, and cognitive measures.

CONCLUSION

This study highlights elevated TNF-α levels and reduced hippocampal volume in MCI MDD patients, indicating a potential association between peripheral inflammation and structural brain alterations in depression. Furthermore, our results suggest that certain cases of MDD may be affected by non-amyloid-mediated process, which impacts their TNF-α and hippocampal volume. These findings emphasize the importance of further investigating the complex interplay among inflammation, neurodegeneration, and cognitive function in MDD.

Differential increase of hippocampal subfield volume after socio-affective mental training relates to reductions in diurnal cortisol

The hippocampus is a central modulator of the HPA-axis, impacting the regulation of stress on brain structure, function, and behavior. The current study assessed whether three different types of 3 months mental Training Modules geared towards nurturing (a) attention-based mindfulness, (b) socio-affective, or (c) socio-cognitive skills may impact hippocampal organization by reducing stress. We evaluated mental training-induced changes in hippocampal subfield volume and intrinsic functional connectivity, by combining longitudinal structural and resting-state fMRI connectivity analysis in 332 healthy adults. We related these changes to changes in diurnal and chronic cortisol levels. We observed increases in bilateral cornu ammonis volume (CA1-3) following the 3 months compassion-based module targeting socio-affective skills (Affect module), as compared to socio-cognitive skills (Perspective module) or a waitlist cohort with no training intervention. Structural changes were paralleled by relative increases in functional connectivity of CA1-3 when fostering socio-affective as compared to socio-cognitive skills. Furthermore, training-induced changes in CA1-3 structure and function consistently correlated with reductions in cortisol output. Notably, using a multivariate approach, we found that other subfields that did not show group-level changes also contributed to changes in cortisol levels. Overall, we provide a link between a socio-emotional behavioural intervention, changes in hippocampal subfield structure and function, and reductions in cortisol in healthy adults.

Investigating Whether a Combination of Electro-Encephalography and Gene Expression Profiling Can Predict the Risk of Chronic Pain: A Protocol for an Observational Prospective Cohort Study

Despite most episodes of low back pain (LBP) being short-lasting, some transition into persistent long-lasting problems. Hence, the need for a deeper understanding of the physiological mechanisms of this is pertinent. Therefore, the aims of the present study are (1) to map pain-induced changes in brain activity and blood gene expression associated with persistent LBP, and (2) to explore whether these brain and gene expression signatures show promise as predictive biomarkers for the development of persistent LBP. The participants will be allocated into three different pain groups (no pain, mild short-lasting, or moderate long-term). One in-person visit, where two blood samples will be collected and sent for RNA sequencing, along with resting 64-channel electro-encephalography measurements before, during, and after a cold pressor test, will be conducted. Thereafter, follow-up questionnaires will be distributed at 2 weeks, 3 months, and 6 months. Recruitment will start during the second quarter of 2024, with expected completion by the last quarter of 2024. The results are expected to provide insight into the relationship between central nervous system activity, gene expression profiles, and LBP. If successful, this study has the potential to provide physiological indicators that are sensitive to the transition from mild, short-term LBP to more problematic, long-term LBP.

Circulating cytokines and vascular dementia: A bi-directional Mendelian randomization study

Inflammatory responses are associated with the development of vascular dementia (VaD). Circulating cytokines modulate the inflammatory response and are important for the immune system. To further elucidate the role of the immune system in VaD, we used Mendelian randomization (MR) to comprehensively and bi-directionally assess the role of circulating cytokines in VaD. Using state-of-the-art genome-wide association studies, we primarily assessed whether different genetic levels of 41 circulating cytokines affect the risk of developing VaD and, in turn, whether the genetic risk of VaD affects these circulating cytokines. We used inverse variance weighting (IVW) and several other MR methods to assess the bidirectional causality between circulating cytokines and VaD, and performed sensitivity analyses. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) was inversely associated with VaD risk [odds ratio (OR): 0.74, 95 % confidence interval (CI): 0.60-0.92, P = 0.007, 0.007]. VaD was associated with seven circulating cytokines: macrophage inflammatory protein 1b (MIP-1 beta) [OR: 1.05, 95 % CI: 1.01-1.08, P = 0.009], Interleukin-12p70 (IL-12) [OR: 1.04, 95 % CI: 1.00-1.08, P = 0.047], Interleukin-17 (IL-17) [OR: 1.04, 95 % CI: 1.00-1.07, P = 0.038], Interleukin-7 (IL-7) [OR: 1.07, 95 % CI: 1.02-1.12, P = 0.009], Interferon gamma (IFN-γ) [OR: 1.03, 95 % CI: 1.00-1.07, P = 0.046], Granulocyte-colony stimulating factor (GCSF) [OR: 1.06, 95 % CI: 1.02-1.09, P = 0.001], Fibroblast growth factor (FGF) [P = 0.001], and Fibroblast growth factor (FGF) [P = 0.001]. Fibroblast growth factor basic (FGF-Basic) [OR: 1.04, 95 % CI: 1.01-1.08, P = 0.02] were positively correlated. Circulating cytokines are associated with VaD, and further studies are needed to determine whether they are effective targets for intervention to prevent or treat VaD.

Diurnal cortisol, neuroinflammation, and neuroimaging visual rating scales in memory clinic patients

BACKGROUND

Neuroinflammation is a hallmark of the Alzheimer's disease (AD) pathogenic process. Cortisol dysregulation may increase AD risk and is related to brain atrophy. This cross-sectional study aims to examine interactions of cortisol patterns and neuroinflammation markers in their association with neuroimaging correlates.

METHOD

134 participants were recruited from the Karolinska University Hospital memory clinic (Stockholm, Sweden). Four visual rating scales were applied to magnetic resonance imaging or computed tomography scans: medial temporal lobe atrophy (MTA), global cortical atrophy (GCA), white matter lesions (WML), and posterior atrophy. Participants provided saliva samples for assessment of diurnal cortisol patterns, and underwent lumbar punctures for cerebrospinal fluid (CSF) sampling. Three cortisol measures were used: the cortisol awakening response, total daily output, and the ratio of awakening to bedtime levels. Nineteen CSF neuroinflammation markers were categorized into five composite scores: proinflammatory cytokines, other cytokines, angiogenesis markers, vascular injury markers, and glial activation markers. Ordinal logistic regressions were conducted to assess associations between cortisol patterns, neuroinflammation scores, and visual rating scales, and interactions between cortisol patterns and neuroinflammation scores in relation to visual rating scales.

RESULT

Higher levels of angiogenesis markers were associated with more severe WML. Some evidence was found for interactions between dysregulated diurnal cortisol patterns and greater neuroinflammation-related biomarkers in relation to more severe GCA and WML. No associations were found between cortisol patterns and visual rating scales.

CONCLUSION

This study suggests an interplay between diurnal cortisol patterns and neuroinflammation in relation to brain structure. While this cross-sectional study does not provide information on causality or temporality, these findings suggest that neuroinflammation may be involved in the relationship between HPA-axis functioning and AD.

Social isolation and cognitive function in patients with schizophrenia: A two years follow-up study

Cognitive impairment is a core characteristic of schizophrenia. Social isolation has been linked to impaired cognitive function among the general population. In this longitudinal study, we examined the association between social isolation and cognitive function among inpatients with schizophrenia. Two waves of data (2019 and 2021) were collected from chronic psychiatric wards. A total of 166 inpatients completed all measurements at baseline and follow-up. Social isolation was measured by incorporating the frequency of social contact and participation, while cognitive functions were assessed by the Taiwan version of the Montreal Cognitive Assessment (MoCA-T). We used multiple linear regression to evaluate the link between baseline social isolation and cognitive function. For the total sample, social isolation was significantly related to poor language abilities (β = -0.17, p = 0.013) and delayed recall (β = -0.15, p = 0.023). Sex-stratified analysis showed that social isolation was significantly related to poor global cognitive function (β = -0.14, p = 0.021) and domain-specific cognitive functions including language abilities (β = -0.26, p = 0.003) and delayed recall (β = -0.19, p = 0.045) in male inpatients. No significant association was found between social isolation and global cognitive function or any cognitive domain (all ps > 0.05) for females. All associations were independent of loneliness and other covariates. These findings suggested that social isolation could predict poor subsequent cognitive function in inpatients with schizophrenia, especially in males. Interventions aimed at enhancing social connections could potentially improve cognitive function in this population.

Simulated Chronic Jet Lag Affects the Structural and Functional Complexity of Hippocampal Neurons in Mice

There has been a long history that chronic circadian disruption such as jet lag or shift work negatively affects brain and body physiology. Studies have shown that circadian misalignment act as a risk factor for developing anxiety and mood-related depression-like behavior. Till date, most studies focused on simulating jet lag in model animals under laboratory conditions by repeated phase advances or phase delay only, while the real-life conditions may differ. In the present study, adult male mice were subjected to simulated chronic jet lag (CJL) by alternately advancing and delaying the ambient light-dark (LD) cycle by 9 h every 2 days, thereby covering a total of 24 days. The effect of CJL was then examined for a range of stress and depression-related behavioral and physiological responses. The results showed that mice exposed to CJL exhibited depression-like behavior, such as anhedonia. In the open field and elevated plus maze test, CJL-exposed mice showed increased anxiety behavior compared to LD control. In addition, CJL-exposed mice showed an increased level of serum corticosterone and proinflammatory cytokine, TNF-α in both serum and hippocampus. Moreover, CJL-exposed mice exhibited a reduction in structural complexity of hippocampal CA1 neurons along with decreased expression of neurotrophic growth factors, BDNF and NGF in the hippocampus compared to LD control. Taken together, our findings suggest that simulated chronic jet lag adversely affects structural and functional complexity in hippocampal neurons along with interrelated endocrine and inflammatory responses, ultimately leading to stress, anxiety, and depression-like behavior in mice.

Dynamic Features of Body Mass Index in Late Life Predict Cognitive Trajectories and Alzheimer's Disease: A Longitudinal Study

Background

The causal relationships of late-life body mass index (BMI) with Alzheimer's disease (AD) remains debated.

Objective

We aimed to assess the associations of dynamic BMI features (ΔBMIs) with cognitive trajectories, AD biomarkers, and incident AD risk.

Methods

We analyzed an 8-year cohort of 542 non-demented individuals who were aged ≥65 years at baseline and had BMI measurements over the first 4 years. ΔBMIs were defined as changing extent (change ≤ or >5%), variability (standard deviation), and trajectories over the first 4 years measured using latent class trajectory modeling. Linear mixed-effect models were utilized to examine the influence of ΔBMIs on changing rates of AD pathology biomarkers, hippocampus volume, and cognitive functions. Cox proportional hazards models were used to test the associations with AD risk. Stratified analyzes were conducted by the baseline BMI group and age.

Results

Over the 4-year period, compared to those with stable BMI, individuals who experienced BMI decreases demonstrated accelerated declined memory function (p = 0.006) and amyloid-β deposition (p = 0.034) while BMI increases were associated with accelerated hippocampal atrophy (p = 0.036). Three BMI dynamic features, including stable BMI, low BMI variability, and persistently high BMI, were associated with lower risk of incident AD (p < 0.005). The associations were validated over the 8-year period after excluding incident AD over the first 4 years. No stratified effects were revealed by the BMI group and age.

Conclusions

High and stable BMI in late life could predict better cognitive trajectory and lower risk of AD.

Fluoxetine combined with swimming exercise synergistically reduces lipopolysaccharide-induced depressive-like behavior by normalizing the HPA axis and brain inflammation in mice

Major depression disorder is a debilitating psychiatric disease affecting millions of people worldwide. This disorder is the leading cause of morbidity and mortality in high-income countries. Selective serotonin reuptake inhibitors such as fluoxetine are first-line drugs for treating depression-related disorders, but not all patients respond well to these antidepressants. This study aimed to evaluate whether fluoxetine combined with aerobic exercise can affect lipopolysaccharide (LPS)-induced depressive-like behavior, hypothalamic-pituitary-adrenal (HPA) axis dysregulation, and brain inflammation in mice. Male mice were exposed to fluoxetine, swimming exercise, or a combination of both and finally treated with LPS. We measured depression-related symptoms such as anhedonia, behavioral despair, weight gain, and food intake. Hormones (corticosterone and testosterone) and cytokines (IL-1β, IL-6, TNF-α, IL-10) were also measured in serum and brain (hippocampus and prefrontal cortex), respectively. The findings indicated that LPS induced anhedonia and behavioral despair and increased corticosterone, hippocampal IL-1β, TNF-α, and decreased testosterone and hippocampal IL-10 in mice. Fluoxetine and exercise separately reduced LPS-induced depressive-like behavior, while their combination synergistically reduced these symptoms in LPS-treated mice. We found fluoxetine alone increased food intake and body weight in LPS-treated mice. Fluoxetine and exercise combination reduced corticosterone, hippocampal TNF-α, and prefrontal IL-6 and TNF-α levels and increased testosterone and hippocampal and prefrontal IL-10 levels more effectively than fluoxetine alone in LPS-treated mice. This study suggests that swimming exercise combined with fluoxetine can affect depression-related behavior, HPA axis, and brain inflammation more effectively than when they are used separately.

Associations between cortisol stress responses and limbic volume and thickness in young adults: An exploratory study

The investigation of the relationship between neural measures of limbic structures and hypothalamic pituitary adrenal axis responses to acute stress exposure in healthy young adults has so far focused in particular on task-based and resting state functional connectivity studies. Thus, the present study examined the association between limbic volume and thickness measures and acute cortisol responses to the psychosocial stress paradigm ScanSTRESS. Using Permutation Analysis of Linear Models controlling for sex, age and total brain volume, the associations between (sex-specific) cortisol increases and human connectome project style anatomical variables of limbic structures (i.e. volume and thickness) were investigated in 66 healthy and young (18-33 years) subjects (35 men, 31 women taking oral contraceptives). In addition, exploratory (sex-specific) bivariate correlations between cortisol increases and structural measures were conducted. The present data provide interesting new insights into the involvement of striato-limbic structures in psychosocial stress processing, suggesting that acute cortisol stress responses are also associated with mere structural measures of the human brain. Thus, our preliminary findings suggest that not only situation- and context-dependent reactions of the limbic system (i.e. blood oxygenation level-dependent reactions) are related to acute (sex-specific) cortisol stress responses but also basal and somewhat more constant structural measures. Our study hereby paves the way for further analyses in this context and highlights the relevance of the topic.

Age-related differences in the neuromuscular performance of fatigue-provoking exercise under severe whole-body hyperthermia conditions

PURPOSE

The purpose of this study was to determine if aging would lead to greater decline in neuromuscular function during a fatiguing task under severe whole-body hyperthermia conditions.

METHODS

Twelve young (aged 19-21 years) and 11 older (aged 65-80 years) males were enrolled in the study, which comprised a randomized control trial under a thermoneutral condition at an ambient temperature of 23°C (CON) and an experimental trial with passive lower body heating in 43°C water (HWI-43°C). Changes in neuromuscular function and fatigability, and physical performance-influencing factors such as psychological, thermoregulatory, neuroendocrine, and immune responses to whole-body hyperthermia were measured.

RESULTS

A slower increase in rectal temperature, and a lower heart rate, thermal sensation, and sweating rate were observed in older males than young males in response to HWI-43°C trial (p < 0.05). Nevertheless, prolactin increased more in response to hyperthermia in young males, while interleukin-6 and cortisol levels increased more in older males (p < 0.05). Peripheral dopamine levels decreased in older males and increased in young males in response to hyperthermia (p < 0.05). Surprisingly, older males demonstrated greater neuromuscular fatigability resistance and faster maximal voluntary contraction (MVC) torque recovery after a 2-min sustained isometric MVC task under thermoneutral and severe hyperthermic conditions (p < 0.05).

CONCLUSION

Neuromuscular performance during fatigue-provoking sustained isometric exercise under severe whole-body hyperthermia conditions appears to decline in both age groups, but a lower relative decline in torque production for older males may relate to lower psychological and thermophysiological strain along with a diminished dopamine response and prolactin release.

Probable Neuropsychological and Cognitive Complications Due to Cytokine Storm in Patients With COVID-19

Introduction

COVID-19 (coronavirus disease 2019) was first identified in China in December 2019 and is rapidly spreading worldwide as a pandemic. Since COVID-19 causes mild to severe acute respiratory syndrome, most studies in this context have focused on pathogenesis primarily in the respiratory system. However, evidence shows that the central nervous system (CNS) may also be affected by COVID-19. Since COVID-19 is spreading, it is necessary to study its possible cognitive effects on COVID-19 patients and their recovery.

Methods

The articles used in this study were searched by keywords, such as cytokine storm and COVID-19, COVID-19 and executive dysfunction, cognitive disorder, and COVID-19, central nervous system (CNS) and COVID-19, coronavirus, neuroinvasion in Science Direct, Scopus, PubMed, Embase, and Web of Science databases based on preferred reporting items for systematic reviews and meta-analysis (PRISMA) checklist. The study evaluates all observational studies published between December 2019 and April 2021 in peer-reviewed journals, including cross-sectional, cohort, case-control studies, case reports, and case series. The search result was 106 articles, of which 73 articles related to COVID-19, the stages of infection by this virus, its effect on the nervous system and neurological symptoms, the cytokine storm caused by this infection, and the possible cognitive consequences caused by this virus in patients, has been reviewed. Other articles were not checked due to their limited relevance to the topic under discussion.

Results

Studies showed that neurons may be directly affected by severe acute respiratory syndrome coronavirus (SARS-CoV)-1 and SARS-CoV-2. Furthermore, various studies indicated that systemic inflammation (so-called "cytokine storm") is also responsible for brain damage induced by infection with SARS-CoV-1 and SARS-CoV-2. In such a way that these patients showed elevated levels of interleukin (IL-), 6, 8, and 10 and of tumor necrosis factor-alpha (TNF-α) in their blood.

Conclusion

Various cognitive defects have been observed following an increased level of cytokines, such as tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-6, 8. Therefore, due to the increased level of these pro-inflammatory factors in the brains of these patients, cognitive deficits can be expected, which need further investigation.

Effect of Yoga Intervention on Inflammatory Biomarkers among Women with Breast Cancer - A Systematic Review

Background

Inflammatory markers play a substantial role in the prognosis of breast cancer (BC). Studies have been conducted, evaluating the effect of yoga intervention (YI) on inflammatory biomarkers among BC cases. This systematic review consolidates the outcome of YI in the cancer microenvironment.

Objective

The objective of the study was to evaluate the effect of YI in the cancer microenvironment among BC women.

Materials and Methods

This review was conducted from May 2021 to December 2021. The inclusion criteria were experimental studies on adult BC cases with isolated YI. Studies conducted among paediatrics, case reports and case series were excluded from the study. Medline (PubMed), Medline (Ovid), Web of Science (WOS), Scopus, CINAHL and Cochrane Central databases were searched. The data were restricted from January 2000 to December 2021 with studies published in English. 'The Cochrane risk of bias assessment tool' was mobilised to evaluate the quality of the included studies.

Results

A total of nine studies met the inclusion criteria and comprised a sample size of 905 BC cases with a mean age of 50.26±8.27 years. Three studies evaluated tumour necrosis factor-alpha (TNF-α) and INTERLEUKIN (IL)-6, where two studies on TNF-α and one on IL-6 favoured the YI group. A study investigated soluble TNF receptor II (TNF-RII) and another on IL-1beta (IL-1β) has shown improved levels post-YI. A downward trend of cortisol levels was noted in four out of five studies. Two studies that examined the C-reactive protein and a study on IL-8 did not show any difference between the YI and the control groups.

Conclusion

This review's findings showed the downregulation of cortisol, markers of inflammation; TNF-α, IL-6, TNF-RII and IL-1β immediately to post-YI. Heterogeneities in terms of YIs, number of days of practice, duration and training received and the grade of BC cases are the concern of this review. However, YI can be considered a supportive therapy for BC.

IL-6 Enhances the Negative Impact of Cortisol on Cognition among Community-Dwelling Older People without Dementia

There is growing evidence that high basal cortisol levels and systemic inflammation independently contribute to cognitive decline among older people without dementia. The present cross-sectional study examined (a) the potential synergistic effect of cortisol levels and systemic inflammation on executive function and (b) whether this effect is more prominent among older people with mild cognitive impairment (MCI). A sub-sample of 99 patients with MCI and 84 older people without cognitive impairment (CNI) (aged 73.8 ± 7.0 years) were recruited from a large population-based cohort in Crete, Greece, and underwent comprehensive neuropsychiatric and neuropsychological evaluation and a single morning measurement of cortisol and IL-6 plasma levels. Using moderated regression models, we found that the relation between cortisol and executive function in the total sample was moderated by IL-6 levels (b = −0.994, p = 0.044) and diagnostic group separately (b = −0.632, p < 0.001). Moreover, the interaction between cortisol and IL-6 levels was significant only among persons with MCI (b = −0.562, p < 0.001). The synergistic effect of stress hormones and systemic inflammation on cognitive status appears to be stronger among older people who already display signs of cognitive decline. Targeting hypercortisolemia and inflammation may be a promising strategy toward improving the course of cognitive decline.

Do Sleep Disturbances have a Dual Effect on Alzheimer's Disease?

Sleep disturbances and Alzheimer's disease have deleterious effects on various physiological and cognitive functions including synaptic plasticity, oxidative stress, neuroinflammation, and memory. In addition, clock genes expression is significantly altered following sleep disturbances, which may be involved in the pathogenesis of Alzheimer's disease. In this review article, we aimed to discuss the role of sleep disturbances and Alzheimer's disease in the regulation of synaptic plasticity, oxidative stress, neuroinflammation, and clock genes expression. Also, we aimed to find significant relationships between sleep disturbances and Alzheimer's disease in the modulation of these mechanisms. We referred to the controversial effects of sleep disturbances (particularly those related to the duration of sleep deprivation) on the modulation of synaptic function and neuroinflammation. We aimed to know that, do sleep disturbances have a dual effect on the progression of Alzheimer's disease? Although numerous studies have discussed the association between sleep disturbances and Alzheimer's disease, the new point of this study was to focus on the controversial effects of sleep disturbances on different biological functions, and to evaluate the potential dualistic role of sleep disturbances in the pathogenesis of Alzheimer's disease.

Oxidative stress impairs cognitive function by affecting hippocampal fimbria volume in drug-naïve, first-episode schizophrenia

Objective

The aim of the present study was to explore influencing factors of cognitive impairments and their interrelationships in drug-naïve, first-episode schizophrenia (SCZ).

Methods

Patients with drug naïve, first episode SCZ and healthy controls (HCs) were enrolled. Cognitive function was assessed by the MATRICS Consensus Cognitive Battery (MCCB). Serum levels of oxidative stress indices, including folate, superoxide dismutase (SOD), uric acid (UA) and homocysteine (Hcy), were determined after an overnight fast. Hippocampal subfield volumes were measured using FreeSurfer. Mediation models were conducted using the SPSS PROCESS v3.4 macro. A false discovery rate (FDR) correction was applied for multiple comparisons.

Results

Sixty-seven patients with SCZ and 65 HCs were enrolled in our study. The patient group had significantly lower serum levels of folate and SOD and higher serum levels of HCY compared with the HCs (all p < 0.05). The patient group had a significantly smaller volume of the whole hippocampus than the HC group (p < 0.05). We also found significant volume differences between the two groups in the following subfields: CA1, molecular layer, GC-ML-DG and fimbria (all p < 0.05, uncorrected). The partial correlation analysis controlling for age and sex showed that the fimbria volume in the patient group was significantly positively associated with NAB scores (r = 0.382, pFDR = 0.024); serum levels of SOD in the patient group showed a significantly positive correlation with fimbria volume (r = 0.360, pFDR = 0.036). Mediation analyses controlling for age and sex showed that the serum levels of SOD in patients with SCZ had significant indirect effects on the NAB scores which were mediated by the fimbria volume [indirect effect = 0.0565, 95% CI from the bootstrap test excluding zero (0.0066 to 0.0891)].

Conclusion

Oxidative stress, a reduction in hippocampal subfield volumes and cognitive impairments occur in early SCZ. Oxidative stress impairs cognitive function by affecting hippocampal subfield volumes.

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

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

Potential neurobiological links between social isolation and Alzheimer's disease risk

It is estimated that 40% of dementia cases could be prevented by modification of lifestyle factors that associate with disease risk. One of these potentially modifiable lifestyle factors is social isolation. In this review, we discuss what is known about associations between social isolation and Alzheimer's disease, the most common cause of dementia. This is particularly relevant in the time of the COVID-19 pandemic when social isolation has been enforced with potential emerging negative impacts on cognition. While there are neurobiological mechanisms emerging that may account for the observed epidemiological associations between social isolation and Alzheimer's disease, more fundamental research is needed to fully understand the brain changes induced by isolation that may make people vulnerable to disease.

Association between cortisol and aging-related hippocampus volume changes in community-dwelling older adults: a 7-year follow-up study

BACKGROUND

Identifying peripheral biomarkers related to modifiable risk factors to prevent dementia at an early stage will be extremely beneficial. We have been studying how older adults can maintain their mental health and continue to live in a familiar community. The aim of this study is to investigate the association between serum cortisol levels and brain volume among older adults in rural Japan.

METHODS

This was a longitudinal study conducted in Kurokawa-cho, Imari, Saga Prefecture, Japan, among people aged 65 years and above, as reported previously. We conducted a survey twice. The first survey was conducted from October 2009 to March 2011 (Timepoint 1) and the second was conducted from November 2016 to September 2017 (Timepoint 2). Blood samples for serum cortisol levels analysis were collected from participants at Timepoint 1. Serum cortisol levels were measured using the enzyme-linked immunosorbent assay. The participants underwent brain MRI examinations, and Mini-Mental State Examination (MMSE) and Clinical Dementia Rating (CDR) for cognitive function assessment at Timepoint 1 and Timepoint 2. We obtained 70 participants (16 men, mean age 72.69 ± 3.18 years; 54 women, mean age 72.69 ± 4.60 years, at Timepoint 1) for analysis. Correlation analysis was performed between serum cortisol levels at baseline (Timepoint 1) and brain volume (Timepoint 1, Timepoint 2, and Timepoint 1-Timepoint 2 difference) using voxel-based morphometry method.

RESULTS

There was no significant difference in serum cortisol levels between men (72.32 ± 17.30 ng/ml) and women (76.60 ± 21.12 ng/ml) at baseline. Additionally, no effect of blood collection time on cortisol levels was observed in these participants. Small volume correction analysis at the cluster level by applying multiple comparison corrections (family-wise error; P < 0.05) showed a negative correlation between serum cortisol levels (Timepoint 1) and brain volume (Timepoint 2) within the region containing the left hippocampus.

CONCLUSIONS

Serum cortisol levels may serve as a peripheral biomarker of age-related volume changes involving the hippocampus in older adults aged 65 years and above.

Alzheimer’s Disease and Inflammaging

Alzheimer’s disease is one of the most common age-related neurodegenerative disorders. The main theory of Alzheimer’s disease progress is the amyloid-β cascade hypothesis. However, the initial mechanisms of insoluble forms of amyloid-β formation and hyperphosphorylated tau protein in neurons remain unclear. One of the factors, which might play a key role in senile plaques and tau fibrils generation due to Alzheimer’s disease, is inflammaging, i.e., systemic chronic low-grade age-related inflammation. The activation of the proinflammatory cell phenotype is observed during aging, which might be one of the pivotal mechanisms for the development of chronic inflammatory diseases, e.g., atherosclerosis, metabolic syndrome, type 2 diabetes mellitus, and Alzheimer’s disease. This review discusses the role of the inflammatory processes in developing neurodegeneration, activated during physiological aging and due to various diseases such as atherosclerosis, obesity, type 2 diabetes mellitus, and depressive disorders.

Cerebrospinal Fluid Cortisol and Dehydroepiandrosterone Sulfate, Alzheimer’s Disease Pathology, and Cognitive Decline

Introduction

Elevated cortisol levels have been reported in Alzheimer’s disease (AD) and may accelerate the development of brain pathology and cognitive decline. Dehydroepiandrosterone sulfate (DHEAS) has anti-glucocorticoid effects and it may be involved in the AD pathophysiology.

Objectives

To investigate associations of cerebrospinal fluid (CSF) cortisol and DHEAS levels with (1) cognitive performance at baseline; (2) CSF biomarkers of amyloid pathology (as assessed by CSF Aβ levels), neuronal injury (as assessed by CSF tau), and tau hyperphosphorylation (as assessed by CSF p-tau); (3) regional brain volumes; and (4) clinical disease progression.

Materials and Methods

Individuals between 49 and 88 years (n = 145) with mild cognitive impairment or dementia or with normal cognition were included. Clinical scores, AD biomarkers, brain MRI volumetry along with CSF cortisol and DHEAS were obtained at baseline. Cognitive and functional performance was re-assessed at 18 and 36 months from baseline. We also assessed the following covariates: apolipoprotein E (APOE) genotype, BMI, and education. We used linear regression and mixed models to address associations of interest.

Results

Higher CSF cortisol was associated with poorer global cognitive performance and higher disease severity at baseline. Cortisol and cortisol/DHEAS ratio were positively associated with tau and p-tau CSF levels, and negatively associated with the amygdala and insula volumes at baseline. Higher CSF cortisol predicted more pronounced cognitive decline and clinical disease progression over 36 months. Higher CSF DHEAS predicted more pronounced disease progression over 36 months.

Conclusion

Increased cortisol in the CNS is associated with tau pathology and neurodegeneration, and with decreased insula and amygdala volume. Both CSF cortisol and DHEAS levels predict faster clinical disease progression. These results have implications for the identification of patients at risk of rapid decline as well as for the development of interventions targeting both neurodegeneration and clinical manifestations of AD.

A short Mindfulness retreat can improve biological markers of stress and inflammation

OBJECTIVE

Mindfulness practice, a form of meditation, has shown benefit for psychological and physical health. In this study, we investigated the effect of an intensive period of Mindfulness practice on some biological mediators of stress and inflammation during a 3-day residential retreat.

METHODS

A total of 95 healthy individuals (aged 18-67) were recruited and randomized to a Mindfulness retreat arm or an active control arm. Before (t0) and after (t1) the intervention, all the participants were assessed for salivary cortisol levels and for a panel of pro- and anti-inflammatory cytokines measured in saliva. Psychometric measures on stress, anxiety and awareness were carried out using PSS, STAI-Y and MAAS questionnaires, respectively.

RESULTS

As to the within-group differences, we observed a statistically significant decrease in perceived stress (β = -8.85, p < 0.0001), and anxiety scores (β = -12.39, p < 0.0001), while awareness increased (β = 15.26, p < 0.0001) between t0 to t1 in retreat participants. In the mindfulness intervention group, we also observed a statistically significant reduction in the levels of pro-inflammatory cytokines IL-6 (β = -0.94 p = 0.001) and IL-8 (β = -176.40, p < 0.0001), and an increase in anti-inflammatory IL-10 (β = 0.89 p < 0.0001) levels at the end of the retreat. At t1 we observed a highly significant correlation between cortisol levels and both anxiety (r = 0.56, p < 0.0001) and perceived stress (r = 0.92, p < 0.0001) scores.

CONCLUSIONS

Mindfulness retreat participants showed a significant reduction in perceived stress and anxiety levels, as well as an improved balance of some key mediators of inflammatory states. Our data provide evidence that a mindfulness retreat may be effective in improving physical and mental health. Future studies with larger numbers of subjects and follow-up periods may examine mindfulness practice as a non-pharmacological alternative to promote stress reduction and overall health and wellbeing.

Acupuncture Can Regulate the Distribution of Lymphocyte Subsets and the Levels of Inflammatory Cytokines in Patients With Mild to Moderate Vascular Dementia

Background: Vascular dementia (VD) is the second most common type of dementia after Alzheimer’s disease, but there is a lack of definitive treatment for VD. Acupuncture treatment is effective in improving the cognitive impairment and behavioral capacity of patients with VD. In recent years, more studies indicated that peripheral inflammation and abnormal peripheral immune function may aggravate neuroinflammation and cognitive dysfunction. However, there are few studies about the acupuncture and the abnormal peripheral immune function of VD. Also, few studies concern the regulating effect of acupuncture on peripheral immunity of patients with VD.

Objective: The aim of this study was to explore the effect of the “sanjiao” acupuncture method on peripheral immunity of patients with mild to moderate VD.

Methods: A total of 30 patients with VD were involved in the acupuncture group (AG), which was treated with the “sanjiao” acupuncture method once a day for six times a week and lasted for 12 weeks, and 30 healthy elderly people were assigned to the normal group (NG), which had no treatment. The distribution of lymphocyte subsets and the levels of some inflammatory cytokines in the peripheral blood of subjects were evaluated using the flow cytometry (FCM) and the enzyme-linked immunosorbent assay (ELISA).

Results: A total of 60 subjects were involved in this study, while 58 subjects completed the entire trial. Before treatment, the levels of CD3⁺ T, CD4⁺ T cells, CD4⁺/CD8⁺, Tregs, B cells, IFN-γ, and IL-10 in patients with VD were significantly decreased compared with the normal group (all P < 0.05 or P < 0.01). The level of TNF-α in peripheral blood of patients with VD was significantly increased (P < 0.01). After acupuncture treatment, the levels of CD3⁺ T, CD4⁺ T cells, and IFN-γ were significantly increased (all P < 0.05 or P < 0.01). The level of TNF-α was significantly decreased (P < 0.01). The proportion of Tregs was increased (P < 0.01), but it was still lower than that of the normal group (P < 0.05).

Conclusion: The acupuncture method can increase the proportion of CD3⁺, CD4⁺ T cells, and Tregs in peripheral blood of patients with VD. And, it reduces the levels of pro-inflammatory factor TNF-α, which achieves the anti-inflammatory effects and immunostimulation. It suggests that acupuncture can improve the peripheral immune dysfunction of patients with VD by regulating the distribution of lymphocyte subsets and the levels of inflammatory cytokines.

Clinical Trial Registration: [www.chictr.org.cn], identifier [ChiCTR-IOR-17012052].

Cerebral Structural Abnormalities and Their Associations With Peripheral Cytokine Levels in a Group of Untreated Patients With Nasopharyngeal Carcinoma

The current study is to characterize the alterations of peripheral cytokines and anatomical brain changes, and their relationships in untreated nasopharyngeal carcinoma (NPC) patients with depressive symptoms. Twenty-nine newly diagnosed NPC patients without any treatment and 46 matched healthy comparisons were recruited, scanned with high-resolution T1 images and assessed psychologically using Hamilton Rating Scale for Depression (HAMD). Serum levels of interleukin-1 beta (IL-1β), IL-2, IL-6, IL-8, IL-10, interferon-gamma (IFN-γ) and transforming growth factor-beta (TGF-β) were measured by quantitative chemiluminescence assay. Inter-group comparisons of anatomical brain measures were performed, and regions with significant inter-group differences were correlated to HAMD scores and cytokines in NPC patients. A subgroup analysis especially within NPC patients with depression was conducted to precisely characterize the associations among serum cytokines, brain changes and depressive symptoms. Relative to healthy subjects, NPC patients showed significantly decreased cortical thickness in the left parahippocampal gyrus, increased surface area in the right superior parietal lobule and precentral gyrus, and increased gray matter volume in the right postcentral gyrus, bilateral caudate nucleus and right thalamus, as well as significantly elevated IL-1β, IL-2 and IL-10. The elevated IL-2 and IL-10 were negatively correlated with surface area in right superior parietal lobule, whilst IL-1β level was positively correlated to HAMD scores. In patients with depression, specific brain changes and evaluated IL-1β were identified, and the IL-1β interacted with right precentral gyrus to significantly affect the depressive symptoms. Our findings provide novel evidence indicating potential effects of inflammation on brain structure and behavior in NPC patients.

White matter in prolonged glucocorticoid response to psychological stress in schizophrenia

Stress is implicated in psychosis etiology and exacerbation, but pathogenesis toward brain network alterations in schizophrenia remain unclear. White matter connects limbic and prefrontal regions responsible for stress response regulation, and white matter tissues are also vulnerable to glucocorticoid aberrancies. Using a novel psychological stressor task, we studied cortisol stress responses over time and white matter microstructural deficits in schizophrenia spectrum disorder (SSD). Cortisol was measured at baseline, 0-, 20-, and 40-min after distress induction by a psychological stressor task in 121 SSD patients and 117 healthy controls (HC). White matter microstructural integrity was measured by 64-direction diffusion tensor imaging. Fractional anisotropy (FA) in white matter tracts were related to cortisol responses and then compared to general patterns of white matter tract deficits in SSD identified by mega-analysis. Differences between 40-min post-stress and baseline, but not acute reactivity post-stress, was significantly elevated in SSD vs HC, time × diagnosis interaction F_2.3,499.9 = 4.1, p = 0.013. All SSD white matter tracts were negatively associated with prolonged cortisol reactivity but all tracts were positively associated with prolonged cortisol reactivity in HC. Individual tracts most strongly associated with prolonged cortisol reactivity were also most impacted in schizophrenia in general as established by the largest schizophrenia white matter study (r = -0.56, p = 0.006). Challenged with psychological stress, SSD and HC mount similar cortisol responses, and impairments arise in the resolution timeframe. Prolonged cortisol elevations are associated with the white matter deficits in SSD, in a pattern previously associated with schizophrenia in general.

Soluble β-amyloid impaired the GABA inhibition by mediating KCC2 in early APP/PS1 mice

Alzheimer's disease (AD) is a neurodegenerative disorder, which has become the leading cause of dementia cases globally. Synaptic failure is an early pathological feature of AD. However, the cause of synaptic failure in AD, especially the GABAergic synaptic activity remains unclear. Extensive evidence indicates that the presence of soluble amyloid-β is an early pathological feature in AD, which triggers synaptic dysfunction and cognitive decline. Our recent study explored the relation of GABAergic transmission and soluble Aβ in early APP/PS1 mice. Firstly, we found soluble Aβ42 levels were significantly increased in serum, hippocampus and prefrontal cortex in 3-4 months APP/PS1 mice, which was much earlier than Aβ plagues formation. In addition, we found TNF-α and BDNF expression levels were increased, while KCC2 and GABA_AR expression were decreased in 3-4 months APP/PS1 hippocampus. When we treated 3-4 months APP/PS1 mice with a potent γ-secretase inhibitor, LY411575, which can reduce the soluble Aβ42 levels, the TNF-α and BDNF protein levels were decreased, while KCC2 and GABA_AR levels were increased. In conclusion, our study suggested soluble Aβ may impaired the GABA inhibition by mediating KCC2 levels in early APP/PS1 mice. KCC2 may be served as a potential biomarker for AD.

Calorie restriction modulates neuro-immune system differently in young and aged rats

Aging weakens and deregulates the immune system and plays an impact on the central nervous system (CNS). A crosstalk in between the CNS-mediated immune system and the body's overall innate immunity is often found to increase and subsequently accelerate neurodegeneration and behavioural impairment during aging. Dietary calorie restriction (CR) is found to be a beneficial non-invasive anti-aging therapy as it shows rejuvenation of stress response, brain functions and behaviour during aging. The present investigation deals with the consequence of CR diet supplementation for two different duration (one and two consecutive months) on aging-related alteration of the immune response in male albino Wistar rats at the level of (a) lymphocyte viability, proliferation, cytotoxicity, and DNA fragmentation in blood, spleen, and thymus and (b) cytokines (IL-6, IL-10, and TNF-α) in blood, spleen, thymus and different brain-regions to understand the effect of CR diet on neuroimmune system. The results depict that CR diet consumption for consecutive one and two months by the aged (18 and 24 months) rats significantly attenuated the aging-related (a) decrease of blood, splenic and thymic lymphocyte viability, proliferative activity, cytotoxicity, and IL-10 level and (b) increase of (i) blood, splenic and thymic DNA fragmentation and (ii) IL-6 and TNF-α level in those tissues and also in different brain regions. Unlike older rats, in young (4 months) rats, the consumption of CR diet under similar conditions affected those above-mentioned immune parameters reversibly and adversely. This study concludes that (a) aging significantly (p < 0.01) deregulates the above-mentioned immune parameters, (b) consecutive consumption of CR diet for one and two months is (i) beneficial (p < 0.05) to the aging-related immune system [lymphocyte viability, lymphocyte proliferation, cytotoxicity, pro (IL-6 and TNF-α)- and anti (IL-10)-inflammatory cytokines], but (ii) adverse (p < 0.05) to the immune parameters of the young rats, and (c) consumption of CR diet for consecutive two months is more potent (p < 0.05) than that due to one month.

Acute Response of Stress System in Multiple Sclerosis

Background: It has long been suspected that exposure to stress is a major factor that can increase the risk of Multiple Sclerosis (MS) and exacerbate it, as a stress-related disorder. Therefore, we conducted this study to investigate the response of the hypothalamic-pituitary-adrenal (HPA) axis and sympathetic-adrenal-medullar (SAM) system to acute social stress. Methods: A total of 46 MS patients and 23 age-sex-matched healthy controls were recruited in the study. The Trier Social Stress Test (TSST) was used to induce acute psychosocial stress. We measured salivary cortisol (SC) to evaluate the HPA axis. In addition, electrocardiography (ECG) was recorded to evaluate the SAM system based on the linear and non-linear features of Heart Rate Variation (HRV). Then, SC and HRV were measured before and after the stress exposure. We also used the Depression Anxiety Stress Scale (DASS) and Emotional Visual Analog Scale (EVAS) to conduct the psychometric assessment and evaluate the perceived stress level, respectively. Results: The mean age of the MS group was 35.38 ± 15 years, with a mean disease duration of 7.4 ± 60. Besides, the HC group's mean age was 35.8 ± 9 years. There were no significant differences in demographic features and DASS scores between the two groups. In response to TSST, both MS and healthy individuals showed a significant increase in the SC levels and EVAS scores, as well as changes in the HRV indices. Notably, significant differences were also found between the two groups regarding the basic and post-stress SC levels, EVAS score, and HRV indices. Unlike the HC group, the SC level returned to its baseline after recovery in the MS group, and the sympathetic tone was more sensitive. Conclusions: Our results indicated that both MS and healthy individuals respond to acute stress regarding neuroendocrine assessment; however, patients with multiple sclerosis show some impairments in this response.

Gene Expression Profile in Different Age Groups and Its Association with Cognitive Function in Healthy Malay Adults in Malaysia

The mechanism of cognitive aging at the molecular level is complex and not well understood. Growing evidence suggests that cognitive differences might also be caused by ethnicity. Thus, this study aims to determine the gene expression changes associated with age-related cognitive decline among Malay adults in Malaysia. A cross-sectional study was conducted on 160 healthy Malay subjects, aged between 28 and 79, and recruited around Selangor and Klang Valley, Malaysia. Gene expression analysis was performed using a HumanHT-12v4.0 Expression BeadChip microarray kit. The top 20 differentially expressed genes at p < 0.05 and fold change (FC) = 1.2 showed that PAFAH1B3, HIST1H1E, KCNA3, TM7SF2, RGS1, and TGFBRAP1 were regulated with increased age. The gene set analysis suggests that the Malay adult's susceptibility to developing age-related cognitive decline might be due to the changes in gene expression patterns associated with inflammation, signal transduction, and metabolic pathway in the genetic network. It may, perhaps, have important implications for finding a biomarker for cognitive decline and offer molecular targets to achieve successful aging, mainly in the Malay population in Malaysia.

Is early life adversity a trigger towards inflammageing?

There are many 'faces' of early life adversity (ELA), such as childhood trauma, institutionalisation, abuse or exposure to environmental toxins. These have been implicated in the onset and severity of a wide range of chronic non-communicable diseases later in life. The later-life disease risk has a well-established immunological component. This raises the question as to whether accelerated immune-ageing mechanistically links early-life adversity to the lifelong health trajectory resulting in either 'poor' or 'healthy' ageing. Here we examine observational and mechanistic studies of ELA and inflammageing, highlighting common and distinct features in these two life stages. Many biological processes appear in common including reduction in telomere length, increased immunosenescence, metabolic distortions and chronic (viral) infections. We propose that ELA shapes the developing immune, endocrine and nervous system in a non-reversible way, creating a distinct phenotype with accelerated immunosenescence and systemic inflammation. We conclude that ELA might act as an accelerator for inflammageing and age-related diseases. Furthermore, we now have the tools and cohorts to be able to dissect the interaction between ELA and later life phenotype. This should, in the near future, allow us to identify the ecological and mechanistic processes that are involved in 'healthy' or accelerated immune-ageing.

In Vitro Effects of St. John's Wort Extract Against Inflammatory and Oxidative Stress and in the Phagocytic and Migratory Activity of Mouse SIM-A9 Microglia

Introduction: Herbal medicinal plants as Hypericum perforatum L., known as St. John’s wort (SJW) have been in use for a long time. SJW that is specifically used for the treatment of depressive disorders. Inflammatory cytokines derived from microglia play an important role in the regulation of the synthesis and reuptake of glutamate and influence synaptic function, morphology and neuronal plasticity. The present study was performed to investigate, whether STW3-VI, a special SJW extract has protective effects on mouse SIM-A9 microglia against cytotoxic and proinflammatory effects of ROS, glutamate, NMDA or cortisol. Additionally, we investigated the effects of SJW on migratory and phagocytic properties of microglia.

Results: Pre-treatment (48 h) of microglia with STW3-VI (5 or 10 μg/ml)—in contrast to desipramine—inhibited the H₂O₂-induced TNF-α release by 20–40%. Pre-treatment (48 h) of microglia with STW3-VI (5 or 10 μg/ml) delayed the 3 or 4 mM H₂O₂-induced intracellular ROS level by 26.9 and 44.4%, respectively. Furthermore, pre-treatment (48 h) of microglia with STW3-VI (5 μg/ml) - in contrast to desipramine - lowered the glutamate-induced cytotoxicity by 13.2%. Besides, pre-treatment (48 h) of microglia with STW3-VI (5 or 10 μg/ml) or desipramine (5 µM) inhibited the NMDA-induced decrease of the viability by 16.5–28.8% or 12%, respectively. Finally, pre-treatment (48 h) of microglia with STW3-VI (5 or 10 μg/ml)—in contrast to desipramine - reduced the cortisol-induced cytotoxicity by 15.5 and 12.9%. Treatment of microglia with STW3-VI (10 or 100 μg/ml) increased the migratory and the phagocytic capacities by 100 and 40%.

Conclusion: Our data provide evidence that STW3-VI—in contrast to desipramine - protects microglia from oxidative stress, NMDA- or glutamate-induced cytotoxicity, and has anti-inflammatory properties that are accompanied by improvement of their migratory and phagocytic capacity. These protective (particularly the anti-inflammatory) properties may be beneficial in the treatment of depressive disorders.

Point-of-use sweat biosensor to track the endocrine-inflammation relationship for chronic disease monitoring

AIM

The hypothalamic-pituitary-adrenal axis is involved in maintaining homeostasis by engaging with the parasympathetic nervous system. During the process of disease affliction, this relationship is disturbed and there is an imbalance driven response observed.

MATERIALS & METHODS

By monitoring the two key components involved in these pathways, cortisol and TNF-α, the manifestations of chronic stress on the body's homeostasis can be evaluated in a comprehensive manner. This work highlights the development of an electrochemical detection system for the two biomarkers through human sweat.

RESULTS

Limit of detection and dynamic ranges are 1 ng/ml, 1-200 ng/ml for cortisol and 1 pg/ml, 1-1000 pg/ml for TNF-α.

CONCLUSION

This wearable system is designed to be a point of use, chronic disease self-monitoring and management platform.

Longitudinal Changes in Fat Mass and the Hippocampus

OBJECTIVE

This study aimed to investigate cross-sectional and longitudinal associations between fat mass (i.e., body mass index [BMI], waist circumference [WC], and waist to hip ratio [WTHR]) and hippocampal volumes.

METHODS

UK Biobank participants (N = 20,395) aged 40 to 70 years (mean follow-up = 7.66 years), were included and categorized into one of four groups, which represented their baseline fat mass status and trajectory of change by follow-up assessment: normal weight to overweight/obesity, overweight/obesity to normal weight (ON), normal weight stable (NS), or overweight/obesity stable (OS). Regression models used NS (WC < 80 cm in women and < 94 cm in men; WTHR < 0.85 in women and < 0.90 in men; BMI < 25 kg/m² in women and men) as the reference group. Hippocampal volumes were automatically segmented using the FMRIB Software Library.

RESULTS

Compared with NS, OS (BMI: B = -62.23 [SE = 16.76]; WC: B = -145.56 [SE = 16.97]; WTHR: B = -101.26 [SE = 19.54]) and ON (BMI: B = -61.1 [SE = 30.3]; WC: B = -93.77 [SE = 24.96]; WTHR: B = -69.92 [SE = 26.22]) had significantly lower hippocampal volumes.

CONCLUSIONS

The detrimental effects of overweight/obesity may extend beyond the duration of overweight/obesity itself.

State Anxiety Is Related to Cortisol Response During Cognitive Testing for Older Adults

Cognitive testing situations can be stressful for both younger and older adults, but threats of cognitive evaluation may be particularly salient among anxious older individuals as they tend to be more concerned than younger adults about their cognitive abilities and age-related cognitive decline. We examined age-related differences in the effect of anxiety on cortisol responses during cognitive testing in a sample of 27 younger (M = 19.8) and 29 older (M = 71.2) adults. Older adults with higher anxiety also had higher during-task cortisol (suggesting higher reactivity to testing) than older adults with lower anxiety and young adults. There was no effect of anxiety on cortisol for younger adults. Simultaneously examining subjective (state anxiety) and physiological (cortisol response) indicators of threat during cognitive testing appears to be especially important for older adults with higher state anxiety. The results are important for understanding cortisol reactivity, particularly in older adults. Researchers who administer cognitive tests to older adults and clinicians who work with older adults with cognitive concerns and/or anxiety may want to consider how they present their material.

Lasting effects of stress physiology on the brain: Cortisol reactivity during preschool predicts hippocampal functional connectivity at school age

Prolonged exposure to glucocorticoid stress hormones, such as cortisol in humans, has been associated with structural and functional changes in the hippocampus. The majority of research demonstrating these associations in humans has been conducted in adult, clinical, or severely maltreated populations, with little research investigating these effects in young or more typically developing populations. The present study sought to address this gap by investigating longitudinal associations between preschool (3−5 years) and concurrent (5–9 years) cortisol reactivity to a laboratory stressor and hippocampal functional connectivity during a passive viewing fMRI scan. Results showed that, after controlling for concurrent cortisol reactivity, greater total cortisol release in response to a stressor during preschool predicted increased anterior and posterior hippocampal connectivity with the precuneus and cingulate gyrus at school-age. These findings are consistent with literature from adult and non-human investigations and suggest lasting impacts of early stress physiology on the brain.

Is There a Contribution of Structural Brain Phenotypes to the Variance in Resting Energy Expenditure before and after Weight Loss in Overweight Females?

Brain gray (GM) and white matter (WM) are associated with resting energy expenditure (REE). The impact of weight loss on GM and WM masses, as well as on their associations with REE and the ratio between body and brain metabolism, i.e., encephalic measure (EM)), are unknown. Longitudinal data of 69 female Caucasian subjects (age range 19–69 years) with detailed information on fat mass (FM), fat free mas (FFM), GM, WM and REE. Mean weight loss was 14.5 ± 11.9 kg with changes in FM (−12.9 ± 9.8 kg), FFM (−1.7 ± 4.8 kg) and REE (−159 ± 191 kcal/24 h) (all p < 0.05). With weight loss, there were no changes in GM and WM. Before and after weight loss, FFM was the main determinant of REE (r² = 0.483 and 0.413; p < 0.05). After weight loss, GM added to the variances in REE (3.6%), REE_adjFFM (6.1%) and the REE on FFM residuals (6.6%). In addition, before and after weight loss GM explained 25.0% and 10.0% of the variances in EM (p < 0.05). Weight loss had no effect on volumes of GM and WM. After weight loss, both, GM added to the variances of REE, REE on FFM residuals and EM.

Neurobiological mechanisms underlying sex-related differences in stress-related disorders: Effects of neuroactive steroids on the hippocampus

Men and women differ in their vulnerability to a variety of stress-related illnesses, but the underlying neurobiological mechanisms are not well understood. This is likely due to a comparative dearth of neurobiological studies that assess male and female rodents at the same time, while human neuroimaging studies often don't model sex as a variable of interest. These sex differences are often attributed to the actions of sex hormones, i.e. estrogens, progestogens and androgens. In this review, we summarize the results on sex hormone actions in the hippocampus and seek to bridge the gap between animal models and findings in humans. However, while effects of sex hormones on the hippocampus are largely consistent in animals and humans, methodological differences challenge the comparability of animal and human studies on stress effects. We summarise our current understanding of the neurobiological mechanisms that underlie sex-related differences in behavior and discuss implications for stress-related illnesses.

Daily hassles, loneliness, and diurnal salivary cortisol in emerging adults

This study used an intensive protocol to examine the effects of daily hassles and loneliness on diurnal salivary cortisol levels. Fifty Chinese undergraduates (28 females) provided six saliva samples each day for two consecutive days (at 0, 0.5, 3, 6, and 12 h after waking and at bedtime) and completed a questionnaire that included scales to measure daily hassles experienced over the previous month, trait loneliness, and depression. Cortisol data were aggregated over two days and used in subsequent analyses, focusing on the cortisol awakening response, diurnal slope, and overall cortisol output operationalized as the area under the curve with reference to the ground (AUC_G). Multiple regression analysis showed that an increase in loneliness had a significant association with an increase in the AUC_G and with a steeper diurnal slope. Loneliness also showed a significant interaction with daily hassles in that the positive association between daily hassles and AUC_G was accentuated in the participants who reported a greater degree of loneliness. Our findings demonstrate for the first time the importance of trait loneliness in modulating the association between daily hassles and diurnal cortisol levels, which has significant clinical implications. Interventions to reduce loneliness should help college students to better cope with daily stressors. Increased attention should also be paid to the health implications of an elevated cortisol level in this relatively young and healthy population.

Association between high levels of inflammatory markers and cognitive outcomes at 4 years of age: The Rhea mother-child cohort study, Crete, Greece

There is growing evidence associating inflammatory markers in complex, higher order neurological functions, such as cognition and memory. We examined whether high levels of various inflammatory markers are associated with cognitive outcomes at 4 years of age in a mother-child cohort in Crete, Greece (Rhea study). We included 642 children in this cross-sectional study. Levels of several inflammatory markers (IFN-γ, IL-1β, IL-6, IL-8, IL-17α, IL-10, MIP-1α, TNF-α and the ratios of IL-6 to IL-10 and TNF-α to IL-10) were determined in child serum via immunoassay. Neurodevelopment at 4 years was assessed by means of the McCarthy Scales of Children's Abilities. Multivariate linear regression analyses were used to estimate the associations between the exposures and outcomes of interest after adjustment for various confounders. Our results indicate that children with high TNF-α concentrations (≥90th percentile) in serum demonstrated decreased scores in memory (adjusted β = -4.0; 95% CI: -7.7, -0.2), working memory (adjusted β = -4.0; 95% CI: -8.0, -0.1) as well as in memory span scale (adjusted β = -4.0; 95% CI: -7.9, -0.1). We also found that children with high IFN-γ serum levels showed lower scores in memory span scale (adjusted β = -3.4; 95% CI: -7.3, -0.4). Children with elevated TNF-α/IL-10 ratio demonstrated decreased quantitative (adjusted β = -4.3; 95% CI: -8.2, -0.4), motor (adjusted β = -3.5; 95% CI: -7.5, -0.5), executive function (adjusted β = -4.8; 95% CI: -8.5, -1.1), general cognitive (adjusted β = -3.6; 95% CI: -7.3, -0.1), memory (adjusted β = -3.8; 95% CI: -7.6, -0), working memory (adjusted β = -3.5; 95% CI: -7.5, -0.5) and memory span scores (adjusted β = -5.3; 95% CI: -9.1, -1.4) The findings suggest that high levels of TNF-α may contribute to reduced memory performance at preschool age.

High Cortisol and the Risk of Dementia and Alzheimer's Disease: A Review of the Literature

Introduction: Cortisol effects on the brain are exerted through two distinct receptors, inducing complex and even opposite effects on the cerebral structures implicated in the various cognitive functions. High cortisol may also have deleterious effects on the brain structures and contribute to neurodegeneration, in particular Alzheimer’s disease (AD), via different mechanisms.

Objective: To examine the interrelationships between cortisol, cognitive impairment and AD.

Methods: Review of the literature.

Results: Clinical studies found that elevated cortisol was associated with poorer overall cognitive functioning, as well as with poorer episodic memory, executive functioning, language, spatial memory, processing speed, and social cognition; while in animals, glucocorticoid administration resulted in cognitive impairment and abnormal behavior. In cognitively healthy subjects, higher cortisol levels have been associated with an increased risk of cognitive decline and AD. Subjects with dementia and Mild Cognitive Impairment (MCI) due to AD have been found to have higher CSF cortisol levels than cognitively healthy controls. Elevated CSF cortisol may also be associated with a more rapid cognitive decline in MCI due to AD. Elevated cortisol levels have been also found in delirium. High cortisol may mediate the impact of stressful life events, high neuroticism, depression, sleep disturbances, as well as cardiovascular risk factors on cognitive performance, neurodegeneration, and cognitive decline. High cortisol may also exert neurotoxic effects on the hippocampus, and promote oxidative stress and amyloid β peptide toxicity. Further possible underlying mechanisms include the interactions of cortisol with inflammatory mediators, neurotransmitters, and growth factors.

Conclusion: Elevated cortisol levels may exert detrimental effects on cognition and contribute to AD pathology. Further studies are needed to investigate cortisol-reducing and glucocorticoidreceptor modulating interventions to prevent cognitive decline.

Inflammatory cytokines and cognitive functioning in early-stage bipolar I disorder

BACKGROUND

Increased circulating inflammatory cytokines is a replicated finding in bipolar I disorder (BDI). Pro-inflammatory cytokines such as TNFα, IL-6 and IL-1 have also been associated with poorer cognitive functioning in patients with longer illness duration. However, the effect of inflammatory cytokines on cognition in early stage patients is not yet known. Here, we investigate the relationship between cytokines and cognition in BDI patients within three years of diagnosis.

METHODS

Serum pro-inflammatory (TNFα, IL-6 and IL-1α) and anti-inflammatory (IL-4 and IL-10) cytokine levels were compared between 51 early stage BDI patients and 20 healthy controls. 46 patients completed neuropsychological testing, and multiple regression analysis was used to assess the association between cytokine levels and cognition after accounting for relevant clinical and demographic variables.

RESULTS

TNFα was elevated at trend level significance in BDI patients compared to healthy controls, and was negatively associated with global cognition, processing speed, and working memory in patients. IL-6, IL-1α, IL-4 and IL-10 levels were comparable between groups and were not significantly associated with cognition.

LIMITATIONS

Direct causation cannot be established in this cross-sectional study; in addition, cytokine levels were not taken on the same day as neuropsychological testing for all patients.

CONCLUSIONS

TNFα may negatively impact cognition in early BDI. While replication is required in larger samples, these results suggest that inhibition of TNFα activity might be a strategy to preserve cognition in newly diagnosed BDI patients.

Cytokine Research in Depression: Principles, Challenges, and Open Questions

Cytokines have been implicated in the pathology of depression. Currently, the evidence is based on cross-sectional studies and meta-analytic research comparing blood concentrations of T helper type 1 (TH1), T helper type 2 (TH2), pro-inflammatory or anti-inflammatory cytokines of patients with a depressive disorder to those of healthy controls. Additionally, multiple longitudinal studies have investigated cytokine levels during antidepressant treatment. According to the current literature, it seems that peripheral levels of interleukin (IL)-6, IL-10, IL-12, IL-13, and tumor necrosis factor (TNF)-α are elevated and that interferon (IFN)-γ levels are lower in patients with depression compared to healthy controls. However, the overlap of cytokine values between acutely depressed patients, remitted and recovered patients and healthy controls is considerable. Thus, the discriminative power of cytokine concentrations between depressed and non-depressed people is likely weak. Treatment with certain antidepressants appears to decrease peripheral levels of IL-6, IL-10, and TNF-α. However, weight gain-inducing psychopharmacological substances, such as the antidepressant mirtazapine, have been reported to potentially increase the production of pro-inflammatory cytokines. Even though cytokines are often discussed as biomarkers for depression, they have also been shown to be altered in other psychiatric disorders. Moreover, many environmental, social, psychological, biological, and medical factors are also associated with cytokine changes. Thus, cytokine alterations seem extremely unspecific. The interpretation of the results of these studies remains a challenge because it is unknown which type of cells are most responsible for cytokine changes measured in the blood nor have the main target cells or target tissues been identified. The same cytokine can be produced by multiple cell types, and the same cell can produce various cytokines. Additionally, redundancy, synergy, antagonism, and signaling cascades of cytokine signaling must be considered. Cytokines might not be associated with the diagnosis of depression according to the currently used diagnostic manuals, but rather with specific subtypes of depression, or with depressive symptoms across different psychiatric diagnoses. Therefore, the currently available diagnostic systems may not be the ideal starting point for psychiatric cytokine research.

Vitamin K status and inflammation are associated with cognition in older Irish adults

Studies have shown associations between reduced vitamin K status and poor cognitive function. However, despite this apparent link, direct studies measuring cognitive function, vitamin K status and inflammation are lacking. In the current study, The ELDERMET cohort was investigated to identify associations between cognition, vitamin K status and inflammation. The primary aim of the ELDERMET study was to investigate the relationship between gut bacteria, diet, lifestyle and health in 500 older Irish adults. Significant differences in serum phylloquinone, dietary phylloquinone and inflammatory markers were found across varying levels of cognitive function, after controlling for sex, age, body mass index (BMI), triglycerides and blood pressure. In addition, significantly higher levels of dietary phylloquinone were found in those with better cognition compared to those with the poorest function. Higher levels of inflammatory were also associated with poor cognition. Furthermore, both dietary and serum phylloquinone were significant independent predictors of good cognitive function, after controlling for confounders. This study highlights the importance of dietary vitamin K as a potentially protective cognitive factor; it also provides evidence for the correlation between cognition and inflammation. Strategies should be devised by which elderly populations can access rich dietary sources of phylloquinone to maintain cognition.

Examining the relationship between nutrition and cerebral structural integrity in older adults without dementia

The proportion of adults aged 60 years and over is expected to increase over the coming decades. This ageing of the population represents an important health issue, given that marked reductions to cerebral macro- and microstructural integrity are apparent with increasing age. Reduced cerebral structural integrity in older adults appears to predict poorer cognitive performance, even in the absence of clinical disorders such as dementia. As such, it is becoming increasingly important to identify those factors predicting cerebral structural integrity, especially factors that are modifiable. One such factor is nutritional intake. While the literature is limited, data from available cross-sectional studies indicate that increased intake of nutrients such as B vitamins (for example, B6, B12 and folate), choline, n-3 fatty acids and vitamin D, or increased adherence to prudent whole diets (for example, the Mediterranean diet) predicts greater cerebral structural integrity in older adults. There is even greater scarcity of randomised clinical trials investigating the effects of nutritional supplementation on cerebral structure, though it appears that supplementation with B vitamins (B6, B12 and folic acid) or n-3 fatty acids (DHA or EPA) may be beneficial. The current review presents an overview of available research examining the relationship between key nutrients or adherence to select diets and cerebral structural integrity in dementia-free older adults.

Role of polyunsaturated fatty acids in human brain structure and function across the lifespan: An update on neuroimaging findings

There is a substantial body of evidence from animal studies implicating polyunsaturated fatty acids (PUFA) in neuroinflammatory, neurotrophic, and neuroprotective processes in brain. However, direct evidence for a role of PUFA in human brain structure and function has been lacking. Over the last decade there has been a notable increase in neuroimaging studies that have investigated the impact of PUFA intake and/or blood levels (i.e., biostatus) on brain structure, function, and pathology in human subjects. The majority of these studies specifically evaluated associations between omega-3 PUFA intake and/or biostatus and neuroimaging outcomes using a variety of experimental designs and imaging techniques. This review provides an updated overview of these studies in an effort to identify patterns to guide and inform future research. While the weight of evidence provides general support for a beneficial effect of a habitual diet consisting of higher omega-3 PUFA intake on cortical structure and function in healthy human subjects, additional research is needed to replicate and extend these findings as well as identify response mediators and clarify mechanistic pathways. Controlled intervention trials are also needed to determine whether increasing n-3 PUFA biostatus can prevent or attenuate neuropathological brain changes observed in patients with or at risk for psychiatric disorders and dementia.