The role of the hypothalamic-pituitary-adrenal axis in neuroendocrine responses to stress

Exploring causal mechanisms of psychosis risk

Robust epidemiological evidence of risk and protective factors for psychosis is essential to inform preventive interventions. Previous evidence syntheses have classified these risk and protective factors according to their strength of association with psychosis. In this critical review we appraise the distinct and overlapping mechanisms of 25 key environmental risk factors for psychosis, and link these to mechanistic pathways that may contribute to neurochemical alterations hypothesised to underlie psychotic symptoms. We then discuss the implications of our findings for future research, specifically considering interactions between factors, exploring universal and subgroup-specific factors, improving understanding of temporality and risk dynamics, standardising operationalisation and measurement of risk and protective factors, and developing preventive interventions targeting risk and protective factors.

The cortisol/DHEA ratio mediates the association between early life stress and externalizing problems in adolescent boys

BACKGROUND

Despite evidence that early life stress (ELS) can influence the functioning of the hypothalamic-pituitary-adrenal (HPA) axis and increase maladaptive behaviors in adolescence, less attention has been paid to the role of the coordinated effects of the two primary adrenal hormones, cortisol and dehydroepiandrosterone (DHEA), in these associations.

METHODS

138 typically developing adolescents (76 females) reported the stressful events experienced during childhood and early adolescence across 30 domains. Two years later we assessed levels of externalizing problems and obtained salivary levels of cortisol and DHEA. Using causal moderated mediation analyses, we examined whether the ratio of cortisol to DHEA (CD ratio) mediates the association between ELS and subsequent externalizing problems.

RESULTS

We found that ELS is associated with both a lower CD ratio and more externalizing problems. Importantly, a lower CD ratio mediated the association between ELS and externalizing problems in boys.

CONCLUSIONS

An imbalance in adrenal hormones may be a mechanism through which ELS leads to an increase in externalizing problems in adolescent boys. These findings underscore the utility of using the CD ratio to index HPA-axis functioning.

Genomic analysis of genotype-environment interaction in age at first calving of Murrah buffaloes

Age at first calving (AFC) is a measure of sexual maturity associated with the start of productive life of dairy animals. Additionally, a lower AFC reduces the generation interval and early culling of females. However, AFC has low heritability, making it a trait highly influenced by environmental factors. In this scenario, one way to improve the reproductive performance of buffalo cows is to select robust animals according to estimated breeding value (EBV) using models that include genotype-environment interaction (GEI) with the application of reaction norm models (RNMs). This can be achieved by understanding the genomic basis related to GEI of AFC. Thus, in this study, we aimed to predict EBV considering GEI via the RNM and identify candidate genes related to this component in dairy buffaloes through genome-wide association studies (GWAS). We used 1795 AFC records from three Murrah buffalo herds and formed environmental gradients (EGs) from contemporary group solutions obtained from genetic analysis of 270-day cumulative milk yield. Heritability estimates ranged from 0.15 to 0.39 along the EG. GWAS of the RNM slope parameter identified important genomic regions. The genomic window that explained the highest percentage of genetic variance of the slope (0.67%) was located on BBU1. After functional analysis, five candidate genes were detected, involved in two biological processes. The results suggested the existence of a GEI for AFC in Murrah buffaloes, with reclassification of animals when different environmental conditions were considered. The inclusion of genomic information increased the accuracy of breeding values for the intercept and slope of the reaction norm. GWAS analysis suggested that important genes associated with the AFC reaction norm slope were possibly also involved in biological processes related to lipid metabolism and immunity.

A comprehensive analysis of the differential expression in the hippocampus of depression induced by gut microbiota compared to traditional stress

Depression, which is a disease of heterogeneous etiology, is characterized by high disability and mortality rates. Gut microbiota are associated with the development of depression. To further explore any differences in the mechanisms of depression induced by gut microbiota and traditional stresses, as well as facilitate the development of microbiota-based interventions, a fecal microbiota transplantation (FMT) depression model was made. This was achieved by transplanting feces from major depressive disorder (MDD) patients into germ-free mice. Second, the mechanisms of the depression induced by gut microbiota were analyzed in comparison with those of the depression caused by different forms of stress. It turned out that mice exhibited depressive-like behavior after FMT. Then, PCR array analysis was performed on the hippocampus of the depressed mice to identify differentially expressed genes (DEGs). The KEGG analysis revealed that the pathways of depression induced by gut microbes are closely associated with immuno-inflammation. To determine the pathogenic pathways of physiological stress and psychological stress-induced depression, raw data was extracted from several databases and KEGG analysis was performed. The results from the analysis revealed that the mechanisms of depression induced by physiological and psychological stress are closely related to the regulation of neurotransmitters and energy metabolism. Interestingly, the immunoinflammatory response was distinct across different etiologies that induced depression. The findings showed that gut microbiota dysbiosis-induced depression was mainly associated with adaptive immunity, while physiological stress-induced depression was more linked to innate immunity. This study compared the pathogenesis of depression caused by gut microbiota dysbiosis, and physiological and psychological stress. We explored new intervention methods for depression and laid the foundation for precise treatment.

From Gut to Brain: Unraveling the Intricate Link Between Microbiome and Stroke

Stroke, a neurological disorder, is intricately linked to the gut microbiota, influencing microbial composition and elevating the risk of ischemic stroke. The neuroprotective impact of short-chain fatty acids (SCFAs) derived from dietary fiber fermentation contrasts with the neuroinflammatory effects of lipopolysaccharide (LPS) from gut bacteria. The pivotal role of the gut-brain axis, facilitating bidirectional communication between the gut and the brain, is crucial in maintaining gastrointestinal equilibrium and influencing cognitive functions. An in-depth understanding of the interplay among the gut microbiota, immune system, and neurological outcomes in stroke is imperative for devising innovative preventive and therapeutic approaches. Strategies such as dietary adjustments, probiotics, prebiotics, antibiotics, or fecal transplantation offer promise in modulating stroke outcomes. Nevertheless, comprehensive research is essential to unravel the precise mechanisms governing the gut microbiota's involvement in stroke and to establish effective therapeutic interventions. The initiation of large-scale clinical trials is warranted to assess the safety and efficacy of interventions targeting the gut microbiota in stroke management. Tailored strategies that reinstate eubiosis and foster a healthy gut microbiota hold potential for both stroke prevention and treatment. This review underscores the gut microbiota as a promising therapeutic target in stroke and underscores the need for continued research to delineate its precise role and develop microbiome-based interventions effectively.

Physiological Stress Responses to a Live-Fire Training Evolution in Career Structural Firefighters

OBJECTIVE

This study assessed firefighters' physiological stress response to a live fire training evolution (LFTE).

METHODS

Seventy-six ( n = 76) firefighters completed an LFTE. Salivary samples were collected pre-, immediately post, and 30-min post-LFTE and analyzed for α-amylase (AA), cortisol (CORT), and secretory immunoglobulin-A (SIgA).

RESULTS

Concentrations of AA, CORT, and SIgA were elevated immediately post LFTE versus pre (P<0.001) and 30-min post (P<0.001). Cohen's d effect size comparing pre and immediately-post means were 0.83, 0.77, and 0.61 for AA, CORT, and SIgA and were 0.54, 0.44, and 0.69 for AA, CORT, and SIgA, comparing immediately-post and 30-min post, respectively.

CONCLUSIONS

These data demonstrate the stress response and activation of the hypothalamic-pituitary-adrenal/sympathetic-adreno-medullar axis and immune system immediately after real-world firefighting operations. Future work is needed to understand the impact of elevated stress biomarkers on firefighter performance and disease risk.

Effects of chronic stress on cancer development and the therapeutic prospects of adrenergic signaling regulation

Long-term chronic stress is an important factor in the poor prognosis of cancer patients. Chronic stress reduces the tissue infiltration of immune cells in the tumor microenvironment (TME) by continuously activating the adrenergic signaling, inhibits antitumor immune response and tumor cell apoptosis while also inducing epithelial-mesenchymal transition (EMT) and tumor angiogenesis, promoting tumor invasion and metastasis. This review first summarizes how adrenergic signaling activates intracellular signaling by binding different adrenergic receptor (AR) heterodimers. Then, we focused on reviewing adrenergic signaling to regulate multiple functions of immune cells, including cell differentiation, migration, and cytokine secretion. In addition, the article discusses the mechanisms by which adrenergic signaling exerts pro-tumorigenic effects by acting directly on the tumor itself. It also highlights the use of adrenergic receptor modulators in cancer therapy, with particular emphasis on their potential role in immunotherapy. Finally, the article reviews the beneficial effects of stress intervention measures on cancer treatment. We think that enhancing the body's antitumor response by adjusting adrenergic signaling can enhance the efficacy of cancer treatment.

Biopsychosocial factors in oral and systemic diseases: a scoping review

Background

The association between chronic oral diseases and other major systemic health conditions, commonly referred to as the oral-systemic health connection, has been previously studied with several underlying common risk factors and pathways linking both groups of diseases. Psychosocial factors contribute to an increased susceptibility to chronic oral and non-oral diseases. The aim of this review is to summarize the current state of knowledge on the role of psychosocial stress in chronic oral and systemic diseases.

Methods

A search strategy was built and a literature search was conducted using four databases (CINAHL, Embase, Medline, PsycINFO). A combination of search terms related to psychosocial stress, systemic disease, and oral conditions were used. Studies were eligible for inclusion if they included human adults (aged 18 years and older), included psychosocial factors as an exposure measure, and outcome measures of both an oral and systemic condition. Only English-language articles were considered. Pilot testing of the data extraction form and calibration were conducted and data were extracted independently by one researcher.

Results

A total of fifteen articles out of eighty full-text articles screened were determined to be eligible for inclusion in this review. Periodontal disease was the most commonly studied oral disease, measured in 53% of included articles, with the most commonly studied systemic diseases being of mental health conditions (40%) and diabetes (47%). Psychosocial stress was measured using a range of psychometric indicators and/or biomarkers, including perceived stress, individual behaviours, childhood adversity, and cortisol. In total, fourteen studies found a positive association between measures of psychosocial stress and oral-systemic health.

Conclusion

Psychosocial stress may be a common contributor to both chronic oral and non-oral diseases.

Hypothalamic protein profiling from mice subjected to social defeat stress

The Hypothalmic-Pituitary-Adrenal axis also known as the HPA axis is central to stress response. It also acts as the relay center between the body and the brain. We analysed hypothalamic proteome from mice subjected to chronic social defeat paradigm using iTRAQ based quantitative proteomics to identify changes associated with stress response. We identified greater than 2000 proteins after processing our samples analysed through Q-Exactive (Thermo) and Orbitrap Velos (Thermo) at 5% FDR. Analysis of data procured from the runs showed that the proteins whose levels were affected belonged primarily to mitochondrial and metabolic processes, translation, complement pathway among others. We also found increased levels of fibrinogen, myelin basic protein (MBP) and neurofilaments (NEFL, NEFM, NEFH) in the hypothalamus from socially defeated mice. Interestingly, research indicates that these proteins are upregulated in blood and CSF of subjects exposed to trauma and stress. Since hypothalamus secreted proteins can be found in blood and CSF, their utility as biomarkers in depression holds an impressive probability and should be validated in clinical samples.

Can Hypnotherapy Be Considered a Valuable Component in the Management of Inflammatory Bowel Disease? Insights from a Comprehensive Review

Despite advancements in medication,managing inflammatory bowel disease (IBD) remains challenging, necessitatingalternative control methods. Gut-directed hypnotherapy, known for alleviating irritable bowel syndrome (IBS), is debated as an IBD management method. Anextensive search across PubMed, Cochrane Library, and Clinicaltrials.govuncovered five randomized trials and two case series involving IBD patients undergoing hypnotherapy. A small trial reported statistically significant remission at one year (p = .04), but larger trials, including one with 63 patients, showed no significant gastrointestinal improvements. The first case series noted post-intervention reduction in the mediators of inflammation in rectal mucosal, without long-term monitoring. The second case series observed the absence of flare episodes in 12 of 13 ulcerative colitis patients during follow-up, possibly influenced by the simultaneous use of two drugs alongside hypnotherapy. Psychological outcomes, demonstrated no significant differences between hypnotherapy and control groups. While current literature doesn't decisively support hypnotherapy for managing IBD symptoms, it underscores the importance of further research, including randomized clinical trials, to thoroughly assess its effectiveness in this context.

Recovery of synaptic loss and depressive-like behavior induced by GATA1 through blocking of the neuroinflammatory response

GATA1, a member of the GATA transcription factor family, is a critical factor in hematopoietic system development. In a previous study, we demonstrated the increased expression of GATA1 in the dorsolateral prefrontal cortex (dlPFC) of patients suffering from depression and described its role as a transcriptional repressor of synapse-related genes. In this study, we investigated how GATA1 globally altered gene expression using multi-omics approaches. Through the combined analyses of ChIPseq, mRNAseq, and small RNAseq, we profiled genes that are potentially affected by GATA1 in cultured cortical neurons, and Gene Ontology (GO) analysis revealed that GATA1 might be associated with immune-related functions. We hypothesized that GATA1 induces immune activation, which has detrimental effects including synapse loss and depressive-like behavior. To test this hypothesis, we first performed a microglial morphometric analysis of a brain having overexpression of GATA1 because microglia are the resident immune cells of the central nervous system. Fractal analysis showed that the ramification and process length of microglia decreased in brains having GATA1 overexpression compared to the control, suggesting that GATA1 overexpression increases the activation of microglia. Through flow cytometry and immunohistochemical analysis, we found that activated microglia showed pro-inflammatory phenotypes characterized by the expression of CD86 and CD68. Finally, we demonstrated that the effects of GATA1 overexpression including synapse loss and depressive-like behavior could be blocked by inhibiting microglial activation using minocycline. These results will elucidate the regulatory mechanisms of GATA1 that affect pathophysiological conditions such as depression and provide a potential target for the treatment of depression.

Investigating the relationship between hippocampus/dentate gyrus volume and hypothalamus metabolism in participants with major depressive disorder

Reduced hippocampal volume occurs in major depressive disorder (MDD), potentially due to elevated glucocorticoids from an overactivated hypothalamus-pituitary-adrenal (HPA) axis. To examine this in humans, hippocampal volume and hypothalamus (HPA axis) metabolism was quantified in participants with MDD before and after antidepressant treatment. 65 participants (n = 24 males, n = 41 females) with MDD were treated in a double-blind, randomized clinical trial of escitalopram. Participants received simultaneous positron emission tomography (PET)/magnetic resonance imaging (MRI) before and after treatment. Linear mixed models examined the relationship between hippocampus/dentate gyrus volume and hypothalamus metabolism. Chi-squared tests and multivariable logistic regression examined the association between hippocampus/dentate gyrus volume change direction and hypothalamus activity change direction with treatment. Multiple linear regression compared these changes between remitter and non-remitter groups. Covariates included age, sex, and treatment type. No significant linear association was found between hippocampus/dentate gyrus volume and hypothalamus metabolism. 62% (38 of 61) of participants experienced a decrease in hypothalamus metabolism, 43% (27 of 63) of participants demonstrated an increase in hippocampus size (51% [32 of 63] for the dentate gyrus) following treatment. No significant association was found between change in hypothalamus activity and change in hippocampus/dentate gyrus volume, and this association did not vary by sex, medication, or remission status. As this multimodal study, in a cohort of participants on standardized treatment, did not find an association between hypothalamus metabolism and hippocampal volume, it supports a more complex pathway between hippocampus neurogenesis and hypothalamus metabolism changes in response to treatment.

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.

CRF binding protein activity in the hypothalamic paraventricular nucleus is essential for stress adaptations and normal maternal behaviour in lactating rats

To ensure the unrestricted expression of maternal behaviour peripartum, activity of the corticotropin-releasing factor (CRF) system needs to be minimised. CRF binding protein (CRF-BP) might be crucial for this adaptation, as its primary function is to sequester freely available CRF and urocortin1, thereby dampening CRF receptor (CRF-R) signalling. So far, the role of CRF-BP in the maternal brain has barely been studied, and a potential role in curtailing activation of the stress axis is unknown. We studied gene expression for CRF-BP and both CRF-R within the paraventricular nucleus (PVN) of the hypothalamus. In lactating rats, Crh-bp expression in the parvocellular PVN was significantly higher and Crh-r1 expression in the PVN significantly lower compared to virgin rats. Acute CRF-BP inhibition in the PVN with infusion of CRF(6-33) increased basal plasma corticosterone concentrations under unstressed conditions in dams. Furthermore, while acute intra-PVN infusion of CRF increased corticosterone secretion in virgin rats, it was ineffective in vehicle (VEH)-pre-treated lactating rats, probably due to a buffering effect of CRF-BP. Indeed, pre-treatment with CRF(6-33) reinstated a corticosterone response to CRF in lactating rats, highlighting the critical role of CRF-BP in maintaining attenuated stress reactivity in lactation. To our knowledge, this is the first study linking hypothalamic CRF-BP activity to hypothalamic-pituitary-adrenal axis regulation in lactation. In terms of behaviour, acute CRF-BP inhibition in the PVN under non-stress conditions reduced blanket nursing 60 min and licking/grooming 90 min after infusion compared to VEH-treated rats, while increasing maternal aggression towards an intruder. Lastly, chronic intra-PVN inhibition of CRF-BP strongly reduced maternal aggression, with modest effects on maternal motivation and care. Taken together, intact activity of the CRF-BP in the PVN during the postpartum period is essential for the dampened responsiveness of the stress axis, as well as for the full expression of appropriate maternal behaviour.

The VENERE Study: EffectiVenEss of a Rehabilitation Treatment With Nordic Walking in ObEse or OveRweight Diabetic PatiEnts With Cardiovascular Disease

Background

Nordic walking (NW) has several potential benefits for individuals with cardiovascular (CV) disease, type 2 diabetes, and obesity and/or overweight. NW improves cardiovascular health, including exercise capacity and blood pressure control. NW enhances glycemic control and insulin sensitivity in diabetes, and aids in weight management and body composition improvement. NW offers additional advantages, such as improvement in muscular strength, joint mobility, physical activity levels, and psychological well-being.

Methods

This open-label study with 3 arms will aim to evaluate the efficacy, safety, and adherence to exercise prescription in obese and/or overweight diabetic patients with CV complications. The primary objective will be to assess the CV performance of participants after a 6-month and a 12-month follow-up period, following a 3-month NW intervention, compared with standard rehabilitation, and with cardiological counseling (control group) training lasting 3 months.

Results

The results of the study will provide valuable insights into the comparative effectiveness of a NW intervention vs standard rehabilitation and control group training in improving CV performance in obese and/or overweight diabetic patients with CV complications. Additionally, safety and adherence data will help inform the feasibility and sustainability of the exercise prescription over an extended period.

Conclusions

These findings may have implications for the development of tailored exercise programs for this specific patient population, with the aim of optimizing CV health outcomes.

Clinical Trials Registration

NCT05987410.

Postweaning stress affects behavior, brain and gut microbiota of adolescent mice in a sex-dependent manner

Aggression is an instinctive behavior that has been reported to be influenced by early-life stress. However, the potential effects of acute stress during the postweaning period, a key stage for brain development, on defensive aggression and the associated mechanism remain poorly understood. In the present study, aggressive behaviors were evaluated in adolescent mice exposed to postweaning stress. Serum corticosterone and testosterone levels, neural dendritic spine density, and gut microbiota composition were determined to identify the underlying mechanism. Behavioral analysis showed that postweaning stress reduced locomotor activity in mice and decreased defensive aggression in male mice. ELISA results showed that postweaning stress reduced serum testosterone levels in female mice. Golgi staining analysis demonstrated that postweaning stress decreased neural dendritic spine density in the medial prefrontal cortex of male mice. 16S rRNA sequencing results indicated that postweaning stress altered the composition of the gut microbiota in male mice. Combined, these results suggested that postweaning stress alters defensive aggression in male mice, which may be due to changes in neuronal structure as well as gut microbiota composition. Our findings highlight the long-lasting and sex-dependent effects of early-life experience on behaviors.

Effects of Withania somnifera Extract in Chronically Stressed Adults: A Randomized Controlled Trial

BACKGROUND

Stress is a known causative factor in modulating cognitive health, which overall well-being and quality of life are dependent on. Long-term stress has been shown to disrupt the balance of the hypothalamic-pituitary-adrenal (HPA) axis. Adaptogens, such as Withania somnifera (ashwagandha), are commonly used in Ayurvedic medicine for stress relief and ameliorating HPA-axis dysfunction. The aim of this study was to support the role of a root and leaf water-extracted ashwagandha extract (WS) in stress reduction by confirming the lowest clinically validated dose for stress management (125 mg/day) in a dose-dependent clinical study in adults with self-reported high stress.

METHODS

An 8-week, randomized, double-blinded, placebo-controlled study to compare the effects of three different WS extract doses (125, 250 and 500 mg) was performed. A total of 131 adults were enrolled, and 98 were included in the final analysis. Attenuation of chronic stress was measured using the 14-item Perceived Stress Scale (PSS) and biochemical-related stress parameters.

RESULTS

We have shown that aqueous WS extract (roots and leaves) safely reduces mild to moderate chronic stress at doses of 125 mg, 250 mg, and 500 mg/day for 8 weeks.

CONCLUSIONS

Our findings demonstrate the stress-reduction capabilities of this well-characterized aqueous extract of WS (root and leaf) at the low dose of 125 mg/day, in a dose-dependent manner, via the modulation of the HPA axis.

TRIAL REGISTRATION

This study was registered with the Clinical Trials Registry-India (CTRI) with the registration number: CTRI/2019/11/022100.

A bidirectional causal relationship study between mental disorders and male and female infertility

Background

The relation between mental disorders (MDs) and infertility can be reciprocal. But exactly which MD affects infertility remains controversial. Our aim was to use Mendelian randomization (MR) to explore bidirectional causality between 15 MDs and male infertility and female infertility.

Methods

The data of MDs, male infertility, and female infertility were derived from published genome-wide association studies (GWAS). The inverse variance weighted method was considered to be the main analytical approach. Sensitivity analysis was performed using MR-Egger, Cochran's Q, radial MR, and MR-PRESSO tests.

Results

Our results found that mood disorders (OR, 1.4497; 95% CI, 1.0093 - 2.0823; P = 0.0444) and attention deficit hyperactivity disorder (OR, 1.3921; 95% CI, 1.0943 - 1.7709; P = 0.0071) were positively correlated with male infertility, but obsessive-compulsive disorder (OR, 0.8208; 95% CI, 0.7146 - 0.9429; P = 0.0052) was negatively associated with male infertility. For females, anorexia nervosa (OR, 1.0898; 95% CI, 1.0070 - 1.1794; P = 0.0329), attention deficit hyperactivity disorder (OR, 1.1013; 95% CI, 1.0041 - 1.2079; P = 0.0406), and major depressive disorder (OR, 1.1423; 95% CI, 1.0213 - 1.2778; P = 0.0199) increased risk of infertility. In reverse relationship, female infertility increased the incidence of bipolar disorder (OR, 1.0009; 95% CI, 1.0001 - 1.0017; P = 0.0281).

Conclusion

We demonstrated the association between five MDs and male or female infertility. Female infertility was also found to be associated with an increased risk of one MD. We look forward to better designed epidemiological studies to support our results.

Colorectal Cancer: Epidemiology, Risk Factors, and Prevention

Colorectal cancer (CRC) is the third most common cancer and the second most common cause of cancer mortality worldwide. There are disparities in the epidemiology of CRC across different populations, most probably due to differences in exposure to lifestyle and environmental factors related to CRC. Prevention is the most effective method for controlling CRC. Primary prevention includes determining and avoiding modifiable risk factors (e.g., alcohol consumption, smoking, and dietary factors) as well as increasing protective factors (e.g., physical activity, aspirin). Further studies, especially randomized, controlled trials, are needed to clarify the association between CRC incidence and exposure to different risk factors or protective factors. Detection and removal of precancerous colorectal lesions is also an effective strategy for controlling CRC. Multiple factors, both at the individual and community levels (e.g., patient preferences, availability of screening modalities, costs, benefits, and adverse events), should be taken into account in designing and implementing CRC screening programs. Health policymakers should consider the best decision in identifying the starting age and selection of the most effective screening strategies for the target population. This review aims to present updated evidence on the epidemiology, risk factors, and prevention of CRC.

Exploring volumetric abnormalities in subcortical L-HPA axis structures in pediatric generalized anxiety disorder

BACKGROUND

Pediatric generalized anxiety disorder (GAD) is debilitating and increasingly prevalent, yet its etiology remains unclear. Some believe the disorder to be propagated by chronic dysregulation of the limbic-hypothalamic-pituitary-adrenal (L-HPA) axis, but morphometric studies of implicated subcortical areas have been largely inconclusive. Recognizing that certain subcortical subdivisions are more directly involved in L-HPA axis functioning, this study aims to detect specific abnormalities in these critical areas.

METHODS

Thirty-eight MRI scans of preschool children with (n = 15) and without (n = 23) GAD underwent segmentation and between-group volumetric comparisons of the basolateral amygdala (BLA), ventral hippocampal subiculum (vSC), and mediodorsal medial magnocellular (MDm) area of the thalamus.

RESULTS

Children with GAD displayed significantly larger vSC compared to healthy peers, F(1, 31) = 6.50, pFDR = .048. On average, children with GAD presented with larger BLA and MDm, Fs(1, 31) ≥ 4.86, psFDR ≤ .054. Exploratory analyses revealed right-hemispheric lateralization of all measures, most notably the MDm, F(1, 31) = 8.13, pFDR = .024, the size of which scaled with symptom severity, r = .83, pFDR = .033.

CONCLUSION

The BLA, vSC, and MDm are believed to be involved in the regulation of anxiety and stress, both individually and collectively through the excitation and inhibition of the L-HPA axis. All were found to be enlarged in children with GAD, perhaps reflecting hypertrophy related to hyperexcitability, or early neuronal overgrowth. Longitudinal studies should investigate the relationship between these early morphological differences and the long-term subcortical atrophy previously observed.

Understanding zebrafish sleep and wakefulness physiology as an experimental model for biomedical research

Sleep is a globally observable fact, or period of reversible distracted rest, that can be distinguished from arousal by various behavioral criteria. Although the function of sleep is an evolutionarily conserved behavior, its mechanism is not yet clear. The zebrafish (Danio rerio) has become a valuable model for neurobehavioral studies such as studying learning, memory, anxiety, and depression. It is characterized by a sleep-like state and circadian rhythm, making it comparable to mammals. Zebrafish are a good model for behavioral studies because they share genetic similarities with humans. A number of neurotransmitters are involved in sleep and wakefulness. There is a binding between melatonin and the hypocretin system present in zebrafish. The full understanding of sleep and wakefulness physiology in zebrafish is still unclear among researchers. Therefore, to make a clear understanding of the sleep/wake cycle in zebrafish, this article covers the mechanism involved behind it, and the role of the neuromodulator system followed by the mechanism of the HPA axis.

Effects of genetically predicted posttraumatic stress disorder on autoimmune phenotypes

Observational studies suggest that posttraumatic stress disorder (PTSD) increases risk for various autoimmune diseases. Insights into shared biology and causal relationships between these diseases may inform intervention approaches to PTSD and co-morbid autoimmune conditions. We investigated the shared genetic contributions and causal relationships between PTSD, 18 autoimmune diseases, and 3 immune/inflammatory biomarkers. Univariate MiXeR was used to contrast the genetic architectures of phenotypes. Genetic correlations were estimated using linkage disequilibrium score regression. Bi-directional, two-sample Mendelian randomization (MR) was performed using independent, genome-wide significant single nucleotide polymorphisms; inverse variance weighted and weighted median MR estimates were evaluated. Sensitivity analyses for uncorrelated (MR PRESSO) and correlated horizontal pleiotropy (CAUSE) were also performed. PTSD was considerably more polygenic (10,863 influential variants) than autoimmune diseases (median 255 influential variants). However, PTSD evidenced significant genetic correlation with nine autoimmune diseases and three inflammatory biomarkers. PTSD had putative causal effects on autoimmune thyroid disease (p = 0.00009) and C-reactive protein (CRP) (p = 4.3 × 10-7). Inferences were not substantially altered by sensitivity analyses. Additionally, the PTSD-autoimmune thyroid disease association remained significant in multivariable MR analysis adjusted for genetically predicted inflammatory biomarkers as potential mechanistic pathway variables. No autoimmune disease had a significant causal effect on PTSD (all p values > 0.05). Although causal effect models were supported for associations of PTSD with CRP, shared pleiotropy was adequate to explain a putative causal effect of CRP on PTSD (p = 0.18). In summary, our results suggest a significant genetic overlap between PTSD, autoimmune diseases, and biomarkers of inflammation. PTSD has a putative causal effect on autoimmune thyroid disease, consistent with existing epidemiologic evidence. A previously reported causal effect of CRP on PTSD is potentially confounded by shared genetics. Together, results highlight the nuanced links between PTSD, autoimmune disorders, and associated inflammatory signatures, and suggest the importance of targeting related pathways to protect against disease and disability.

Cortisol in functional neurological disorders: State, trait and prognostic biomarkers

OBJECTIVE

Biological stress dysregulation, such as a flattened cortisol awakening response (CAR), has been identified in functional neurological disorder (FND). This longitudinal study aimed to explore whether CAR alterations in FND serve as state or trait biomarkers, assessing temporal changes in cortisol and clinical outcomes to test its prognostic value.

METHODS

Salivary cortisol was measured in 53 patients with mixed FND at two visits separated by eight months (M0 and M8). CAR was calculated based on five consecutive samples, each taken with 15-min time intervals, collected upon awakening, whereas cortisol amplitude (CAmp) was calculated as the difference between the morning peak and the afternoon trough. Clinical outcome was assessed with the Functional Movement Disorder Rating Scale (S-FMDRS), Clinical global impression (CGI) scores for severity (CGI-S) and improvement (CGI-I) and the short-form health survey (SF-36).

RESULTS

No differences in CAR levels were found between M0 and M8 regardless of clinical outcome (remained flattened). However, a good clinical outcome was associated with an earlier peak in the CAR (p = .013, odds ratio: 1.78; 95%-confidence interval: 0.095-1.13). A higher CAmp at M0 predicted a better outcome at M8 (β = 1.14, 95%-confidence interval:0.15-2.13, p = .03).

CONCLUSION

A flattened CAR might represent a trait marker for FND, when an earlier peak in the CAR may serve as a state biomarker. The CAmp demonstrates predictive power for clinical outcome, potentially representing a prognostic biomarker for FND. Further replication and follow-up studies are essential to confirm this suggested role of cortisol as a multifaceted biomarker of FND.

A Perspective Review on Diet Quality, Excess Adiposity, and Chronic Psychosocial Stress and Implications for Early-Onset Colorectal Cancer

Colorectal cancer (CRC) is the third most common cancer worldwide. Although the overall incidence of CRC has been decreasing over the past 40 y, early-onset colorectal cancer (EOCRC), which is defined as a CRC diagnosis in patients aged >50 y has increased. In this Perspective, we highlight and summarize the association between diet quality and excess adiposity, and EOCRC. We also explore chronic psychosocial stress (CPS), a less investigated modifiable risk factor, and EOCRC. We were able to show that a poor-quality diet, characterized by a high intake of sugary beverages and a Western diet pattern (high intake of red and processed meats, refined grains, and foods with added sugars) can promote risk factors associated with EOCRC development, such as an imbalance in the composition and function of the gut microbiome, presence of chronic inflammation, and insulin resistance. Excess adiposity, particularly obesity onset in early adulthood, is a likely contributor of EOCRC. Although the research is sparse examining CPS and CRC/EOCRC, we describe likely pathways linking CPS to tumorigenesis. Although additional research is needed to understand what factors are driving the uptick in EOCRC, managing body weight, improving diet quality, and mitigating psychosocial stress, may play an important role in reducing an individual's risk of EOCRC.

Therapeutic potential of vasopressin in the treatment of neurological disorders

Vasopressin (VP) is a nonapeptide made of nine amino acids synthesized by the hypothalamus and released by the pituitary gland. VP acts as a neurohormone, neuropeptide and neuromodulator and plays an important role in the regulation of water balance, osmolarity, blood pressure, body temperature, stress response, emotional challenges, etc. Traditionally VP is known to regulate the osmolarity and tonicity. VP and its receptors are widely expressed in the various region of the brain including cortex, hippocampus, basal forebrain, amygdala, etc. VP has been shown to modulate the behavior, stress response, circadian rhythm, cerebral blood flow, learning and memory, etc. The potential role of VP in the regulation of these neurological functions have suggested the therapeutic importance of VP and its analogues in the management of neurological disorders. Further, different VP analogues have been developed across the world with different pharmacotherapeutic potential. In the present work authors highlighted the therapeutic potential of VP and its analogues in the treatment and management of various neurological disorders.

Signaling mechanisms underlying activity-dependent integration of adult-born neurons in the mouse olfactory bulb

Adult neurogenesis has fascinated the field of neuroscience for decades given the prospects of harnessing mechanisms that facilitate the rewiring and/or replacement of adult brain tissue. The subgranular zone of the hippocampus and the subventricular zone of the lateral ventricle are the two main areas in the brain that exhibit ongoing neurogenesis. Of these, adult-born neurons within the olfactory bulb have proven to be a powerful model for studying circuit plasticity, providing a broad and accessible avenue into neuron development, migration, and continued circuit integration within adult brain tissue. This review focuses on some of the recognized molecular and signaling mechanisms underlying activity-dependent adult-born neuron development. Notably, olfactory activity and behavioral states contribute to adult-born neuron plasticity through sensory and centrifugal inputs, in which calcium-dependent transcriptional programs, local translation, and neuropeptide signaling play important roles. This review also highlights areas of needed continued investigation to better understand the remarkable phenomenon of adult-born neuron integration.

Life-course stress, cognition, and diurnal cortisol in memory clinic patients without dementia

AIMS

To examine associations of life-course stress with cognition and diurnal cortisol patterns in older adulthood, as well as potential mediation effects of diurnal cortisol patterns and perceived stress on the association between life-course stress and cognition.

METHODS

127 participants without dementia were selected from a cohort of Swedish memory clinic patients. Cross-sectional associations between scores on two chronic stress questionnaires (perceived stress, stressful life events (SLEs)), five cognitive domains (overall cognition, memory, working memory, processing speed, perceptual reasoning), and two measures of diurnal cortisol patterns (total daily output, diurnal cortisol slope), as well as potential mediation effects of diurnal cortisol patterns and perceived stress on associations between life-course stress and cognition, were assessed using linear regressions.

RESULTS

Greater lifetime exposure to SLEs was associated with worse memory, working memory, and processing speed performance, but not with diurnal cortisol patterns. A greater number of SLEs in late childhood was associated with worse working memory and processing speed, while a greater number of SLEs in non-recent adulthood were associated with better overall cognition and perceptual reasoning. Greater perceived stress was associated with a flattened diurnal cortisol slope, but not with cognition. No evidence for interplay between self-reported and physiological stress markers was found in relation to cognition, although there appeared to be a significant positive indirect association between economic/legal SLEs and the diurnal cortisol slope via perceived stress.

CONCLUSIONS

The associations between SLEs and cognition depend on the period during which SLEs occur, but seem independent of late-life cortisol dysregulation.

Pituitary volumes in patients with adjustment disorder

The pituitary gland plays an important role in the stress response mechanism. Given the direct link between adjustment disorder and stress, we hypothesized that there might be changes in the pituitary gland in these patients. The study comprised a patient group of 19 individuals with adjustment disorder according to the Diagnostic and Statistical Manual of Mental Disorders Fifth Edition, and 18 healthy controls. The mean pituitary gland volumes of the patient group were not statistically significantly different from those of the healthy control group (80.81 ± 1.82 mm3 in patients with adjustment disorder vs. 81.10 ± 7.04 mm3 in healthy controls, with a statistically nonsignificant difference of P > 0.05). This finding is contrary to our previous findings in anxiety-related disorders. In this regard, adjustment disorder is not similar to anxiety-related disorders in terms of pituitary gland volumes. We should also clearly state that our study is a pioneering study and that studies with large samples are needed to support our findings. The limitations of our study can be attributed to the small sample size, the utilization of a cross-sectional design, and the inclusion of patients using psychotropic drugs.

Zona Glomerulosa-Derived Klotho Modulates Aldosterone Synthase Expression in Young Female Mice

Klotho plays a critical role in the regulation of ion and fluid homeostasis. A previous study reported that haplo-insufficiency of Klotho in mice results in increased aldosterone synthase (CYP11B2) expression, elevated plasma aldosterone, and high blood pressure. This phenotype was presumed to be the result of diminished Klotho expression in zona glomerulosa (zG) cells of the adrenal cortex; however, systemic effects on adrenal aldosterone production could not be ruled out. To examine whether Klotho expressed in the zG is indeed a critical regulator of aldosterone synthesis, we generated a tamoxifen-inducible, zG-specific mouse model of Klotho deficiency by crossing Klotho-flox mice with Cyp11b2-CreERT mice (zG-Kl-KO). Tamoxifen-treated Cyp11b2-CreERT animals (zG-Cre) served as controls. Rosa26-mTmG reporter mice were used for Cre-dependent lineage-marking. Two weeks after tamoxifen induction, the specificity of the zG-Cre line was verified using immunofluorescence analysis to show that GFP expression was restricted to the zG. RNA in situ hybridization revealed a 65% downregulation of Klotho messenger RNA expression in the zG of zG-Kl-KO female mice at age 12 weeks compared to control mice. Despite this significant decrease, zG-Kl-KO mice exhibited no difference in plasma aldosterone levels. However, adrenal CYP11B2 expression and the CYP11B2 promotor regulatory transcription factors, NGFIB and Nurr1, were enhanced. Together with in vitro experiments, these results suggest that zG-derived Klotho modulates Cyp11b2 but does not evoke a systemic phenotype in young adult mice on a normal diet. Further studies are required to investigate the role of adrenal Klotho on aldosterone synthesis in aged animals.

Mind over Microbes: Investigating the Interplay between Lifestyle Factors, Gut Microbiota, and Brain Health

BACKGROUND

The gut microbiota (GM) of the human body comprises several species of microorganisms. This microorganism plays a significant role in the physiological and pathophysiological processes of various human diseases.

METHODS

The literature review includes studies that describe causative factors that influence GM. The GM is sensitive to various factors like circadian rhythms, environmental agents, physical activity, nutrition, and hygiene that together impact the functioning and composition of the gut microbiome. This affects the health of the host, including the psycho-neural aspects, due to the interconnectivity between the brain and the gut. Hence, this paper examines the relationship of GM with neurodegenerative disorders in the context of these aforesaid factors.

CONCLUSION

Future studies that identify the regulatory pathways associated with gut microbes can provide a causal link between brain degeneration and the gut at a molecular level. Together, this review could be helpful in designing preventive and treatment strategies aimed at GM, so that neurodegenerative diseases can be treated.

Lead exposure, glucocorticoids, and physiological stress across the life course: A systematic review

The biological pathways linking lead exposure to adverse outcomes are beginning to be understood. Rodent models suggest lead exposure induces dysfunction within the hypothalamic-pituitary-adrenal (HPA) axis and glucocorticoid regulation, a primary physiological stress response system. Over time, HPA axis and glucocorticoid dysfunction has been associated with adverse neurocognitive and cardiometabolic health, much like lead exposure. This systematic review utilized PRISMA guidelines to synthesize the literature regarding associations between lead exposure and downstream effector hormones of the HPA axis, including cortisol, a glucocorticoid, and dehydroepiandrosterone (DHEA), a glucocorticoid antagonist. We additionally determined the state of the evidence regarding lead exposure and allostatic load, a measure of cumulative body burden resultant of HPA axis and glucocorticoid dysfunction. A total of 18 articles were included in the review: 16 assessed cortisol or DHEA and 3 assessed allostatic load. Generally, the few available child studies suggest a significant association between early life lead exposure and altered cortisol, potentially suggesting the impact of developmental exposure. In adulthood, only cross sectional studies were available. These reported significant associations between lead and reduced cortisol awakening response and increased cortisol reactivity, but few associations with fasting serum cortisol. Two studies reported significant associations between increasing lead exposure and allostatic load in adults and another between early life lead exposure and adolescent allostatic load. The paucity of studies examining associations between lead exposure and allostatic load or DHEA and overall heterogeneity of allostatic load measurements limit conclusions. However, these findings cautiously suggest associations between lead and dysregulation of physiological stress pathways (i.e., glucocorticoids) as seen through cortisol measurement in children and adults. Future research would help to elucidate these associations and could further examine the physiological stress pathway as a mediator between lead exposure and detrimental health outcomes.

A theory of the neural mechanisms underlying negative cognitive bias in major depression

The widely acknowledged cognitive theory of depression, developed by Aaron Beck, focused on biased information processing that emphasizes the negative aspects of affective and conceptual information. Current attempts to discover the neurological mechanism underlying such cognitive and affective bias have successfully identified various brain regions associated with severally biased functions such as emotion, attention, rumination, and inhibition control. However, the neurobiological mechanisms of how individuals in depression develop this selective processing toward negative is still under question. This paper introduces a neurological framework centered around the frontal-limbic circuit, specifically analyzing and synthesizing the activity and functional connectivity within the amygdala, hippocampus, and medial prefrontal cortex. Firstly, a possible explanation of how the positive feedback loop contributes to the persistent hyperactivity of the amygdala in depression at an automatic level is established. Building upon this, two hypotheses are presented: hypothesis 1 revolves around the bidirectional amygdalohippocampal projection facilitating the amplification of negative emotions and memories while concurrently contributing to the impediment of the retrieval of opposing information in the hippocampus attractor network. Hypothesis 2 highlights the involvement of the ventromedial prefrontal cortex in the establishment of a negative cognitive framework through the generalization of conceptual and emotional information in conjunction with the amygdala and hippocampus. The primary objective of this study is to improve and complement existing pathological models of depression, pushing the frontiers of current understanding in neuroscience of affective disorders, and eventually contributing to successful recovery from the debilitating affective disorders.

Autonomic brain functioning and age-related health concerns

The autonomic nervous system (ANS) regulates involuntary bodily functions such as blood pressure, heart rate, breathing, and digestion, in addition to controlling motivation and behavior. In older adults, the ANS is dysregulated, which changes the ability of the ANS to respond to physiological signals, regulate cardiovascular autonomic functionality, diminish gastric motility, and exacerbate sleep problems. For example, a decrease in heart rate variability, or the variation in the interval between heartbeats, is one of the most well-known alterations in the ANS associated with health issues, including cardiovascular diseases and cognitive decline. The inability to perform fundamental activities of daily living and compromising the physiological reactivity or motivational responses of older adults to moving toward or away from specific environmental stimuli are significant negative consequences of chronic and geriatric conditions that pose grave threats to autonomy, health, and well-being. The most updated research has investigated the associations between the action responsiveness of older adults and the maintenance of their physiological and physical health or the development of mental and physical health problems. Once autonomic dysfunction may significantly influence the development of different age-related diseases, including ischemic stroke, cardiovascular disease, and autoimmune diseases, this review aimed to assess the relationship between aging and autonomic functions. The review explored how motivational responses, physiological reactivity, cognitive processes, and lifelong developmental changes associated with aging impact the ANS and contribute to the emergence of health problems.

Genetically encoded sensors for in vivo detection of neurochemicals relevant to depression

Depressive disorders are a common and debilitating form of mental illness with significant impacts on individuals and society. Despite the high prevalence, the underlying causes and mechanisms of depressive disorders are still poorly understood. Neurochemical systems, including serotonin, norepinephrine, and dopamine, have been implicated in the development and perpetuation of depressive symptoms. Current treatments for depression target these neuromodulator systems, but there is a need for a better understanding of their role in order to develop more effective treatments. Monitoring neurochemical dynamics during depressive symptoms is crucial for gaining a better a understanding of their involvement in depressive disorders. Genetically encoded sensors have emerged recently that offer high spatial-temporal resolution and the ability to monitor neurochemical dynamics in real time. This review explores the neurochemical systems involved in depression and discusses the applications and limitations of current monitoring tools for neurochemical dynamics. It also highlights the potential of genetically encoded sensors for better characterizing neurochemical dynamics in depression-related behaviors. Furthermore, potential improvements to current sensors are discussed in order to meet the requirements of depression research.

Effect of high-intensity interval training on self-care and anxiety-like behaviors in naive rats

Self-care behavior covers individual's health, life and well-being to maintain the necessary activities. The aim of this study is to examine the self-care and possible anxiolytic effects of high-intensity interval exercise (HIIT). Eight-week-old Wistar Albino male rats were divided into Control (n = 8), and Exercise (n = 8). Rat exercised for 38 min a day, 5 days a week, for 8 weeks The animals were then subjected to open field test and splash test, and the behaviors were video recorded. Student t test and Shapiro-Wilk test were used as statistical tests. In the exercise group, spray-induced grooming behavior increased significantly in terms of duration and frequency (p < 0.05), but no significant difference was observed in the latency of grooming (p > 0.05). In the open-field test, the total distance traveled, which is a locomotor activity parameter, did not change between the groups. Anxiolytic-like behaviors such as total rearing behavior, unsupported rearing, central time, and central region entries increased remarkably in the exercise group vs. control (p < 0.0001). Freezing as an anxiogenic behavior decreased in the exercise group positively (p < 0.0001). Intermittent high-intensity exercise improved and increased self-care behaviors. Further, the present study shows that HIIT has beneficial effects on different aspects of behaviors such as exploratory behaviors, increasing anxiolytic behaviors, and reducing anxiogenic behavior. The present study is a preclinical study that will pave the way for new studies.

The impact of parental and developmental stress on DNA methylation in the avian hypothalamic-pituitary-adrenal axis

The hypothalamic-pituitary-adrenal (HPA) axis coordinates an organism's response to environmental stress. The responsiveness and sensitivity of an offspring's stress response may be shaped not only by stressors encountered in their early post-natal environment but also by stressors in their parent's environment. Yet, few studies have considered how stressors encountered in both of these early life environments may function together to impact the developing HPA axis. Here, we manipulated stressors in the parental and post-natal environments in a population of house sparrows (Passer domesticus) to assess their impact on changes in DNA methylation (and corresponding gene expression) in a suite of genes within the HPA axis. We found that nestlings that experienced early life stress across both life-history periods had higher DNA methylation in a critical HPA axis gene, the glucocorticoid receptor (NR3C1). In addition, we found that the life-history stage when stress was encountered impacted some genes (HSD11B1, NR3C1 and NR3C2) differently. We also found evidence for the mitigation of parental stress by post-natal stress (in HSD11B1 and NR3C2). Finally, by assessing DNA methylation in both the brain and blood, we were able to evaluate cross-tissue patterns. While some differentially methylated regions were tissue-specific, we found cross-tissue changes in NR3C2 and NR3C1, suggesting that blood is a suitable tissue for assessing DNA methylation as a biomarker of early life stress. Our results provide a crucial first step in understanding the mechanisms by which early life stress in different life-history periods contributes to changes in the epigenome of the HPA axis.

Validity of mental and physical stress models

Different stress models are employed to enhance our understanding of the underlying mechanisms and explore potential interventions. However, the utility of these models remains a critical concern, as their validities may be limited by the complexity of stress processes. Literature review revealed that both mental and physical stress models possess reasonable construct and criterion validities, respectively reflected in psychometrically assessed stress ratings and in activation of the sympathoadrenal system and the hypothalamic-pituitary-adrenal axis. The findings are less robust, though, in the pharmacological perturbations' domain, including such agents as adenosine or dobutamine. Likewise, stress models' convergent- and discriminant validity vary depending on the stressors' nature. Stress models share similarities, but also have important differences regarding their validities. Specific traits defined by the nature of the stressor stimulus should be taken into consideration when selecting stress models. Doing so can personalize prevention and treatment of stress-related antecedents, its acute processing, and chronic sequelae. Further work is warranted to refine stress models' validity and customize them so they commensurate diverse populations and circumstances.

Gut microbiota in overweight and obesity: crosstalk with adipose tissue

Overweight and obesity are characterized by excessive fat mass accumulation produced when energy intake exceeds energy expenditure. One plausible way to control energy expenditure is to modulate thermogenic pathways in white adipose tissue (WAT) and/or brown adipose tissue (BAT). Among the different environmental factors capable of influencing host metabolism and energy balance, the gut microbiota is now considered a key player. Following pioneering studies showing that mice lacking gut microbes (that is, germ-free mice) or depleted of their gut microbiota (that is, using antibiotics) developed less adipose tissue, numerous studies have investigated the complex interactions existing between gut bacteria, some of their membrane components (that is, lipopolysaccharides), and their metabolites (that is, short-chain fatty acids, endocannabinoids, bile acids, aryl hydrocarbon receptor ligands and tryptophan derivatives) as well as their contribution to the browning and/or beiging of WAT and changes in BAT activity. In this Review, we discuss the general physiology of both WAT and BAT. Subsequently, we introduce how gut bacteria and different microbiota-derived metabolites, their receptors and signalling pathways can regulate the development of adipose tissue and its metabolic capacities. Finally, we describe the key challenges in moving from bench to bedside by presenting specific key examples.

Inter- and transgenerational heritability of preconception chronic stress or alcohol exposure: Translational outcomes in brain and behavior

Chronic stress and alcohol (ethanol) use are highly interrelated and can change an individual's behavior through molecular adaptations that do not change the DNA sequence, but instead change gene expression. A recent wealth of research has found that these nongenomic changes can be transmitted across generations, which could partially account for the "missing heritability" observed in genome-wide association studies of alcohol use disorder and other stress-related neuropsychiatric disorders. In this review, we summarize the molecular and behavioral outcomes of nongenomic inheritance of chronic stress and ethanol exposure and the germline mechanisms that could give rise to this heritability. In doing so, we outline the need for further research to: (1) Investigate individual germline mechanisms of paternal, maternal, and biparental nongenomic chronic stress- and ethanol-related inheritance; (2) Synthesize and dissect cross-generational chronic stress and ethanol exposure; (3) Determine cross-generational molecular outcomes of preconception ethanol exposure that contribute to alcohol-related disease risk, using cancer as an example. A detailed understanding of the cross-generational nongenomic effects of stress and/or ethanol will yield novel insight into the impact of ancestral perturbations on disease risk across generations and uncover actionable targets to improve human health.

The effect of childhood depression trajectories on sugar-sweetened beverage habit trajectories in adolescence: Exploring sleep problems as a mediator

Although depression has been linked to the habit of consuming sugar-sweetened beverages (SSBs), little is known about their long-term relationships and the mediating role of sleep problems. This study examines the associations between childhood depressive symptoms trajectories and adolescent SSB-habit trajectories and whether these associations were mediated by sleep problems. Data came from 1560 adolescents participating in a longitudinal study across grades 1 through 12 in northern Taiwan. Group-based trajectory modeling was used to identify development of childhood depressive symptoms and an SSB habit in adolescence. Multinomial logistic regression was conducted to examine the influence of childhood depressive symptoms and adolescent SSB habit. Mediation analysis was conducted to test whether sleep problems mediated the associations examined. Four distinct trajectories of childhood depressive symptoms were identified: low-stable (30.79%), moderate-stable (42.32%), increasing (12.29%), and high-stable (11.60%). Three distinct trajectories of SSB habit in adolescence were identified: low-stable (44.32%), increasing (15.02%), and high-stable (40.65%). Children who had moderate-stable (aOR = 1.35; CI: 1.04-1.77), high-stable (aOR = 2.01; CI: 1.28-3.15), or increasing (aOR = 1.97; CI: 1.26-3.06) trajectories of depressive symptoms relative to those in the low-stable group were significantly more likely to belong to the high-stable trajectory of SSBs than to the low-stable SSBs group. The Z-mediation test showed that sleep problems significantly mediated the associations between trajectories of childhood depressive symptoms and trajectories of SSBs during adolescence (all p < 0.05). Childhood depressive symptoms conferred risks for adolescent SSB habits; and the effects were seen, in part, through increasing sleep problems.

The influence of anaesthesia on cancer growth

BACKGROUND

Oncological patients make up a large proportion of all surgical patients. Through its influence on the patient's inflammatory and immune system, the choice of anaesthetic technique has an indirect impact on the health of the individual patient and on public health. Both the specific and the non-specific immune system have a major influence on the recurrence of carcinomas. The pathophysiological basis for growth and metastasis after surgery is the physiological response to stress. Inflammation is the organism's universal response to stress. Anaesthetics and adjuvants influence perioperative inflammation in different ways and have an indirect effect on tumour growth and metastasis. In vitro studies have shown how individual anaesthetics influence the growth and spread of cancer, but clinical studies have not confirmed these results. Nevertheless, it is advisable to use an anaesthetic that has shown lesser effect on the growth of cancer cells in vitro.

CONCLUSIONS

In this review, we focus on the area of the effects of anaesthesia on tumour growth. The field is still relatively unexplored, there are only few clinical prospective studies and their results are controversial. Based on the review of new research findings we report on recommendations about anaesthetics and anaesthetic techniques that might be preferable for oncological surgical procedures.

Cortisol as a Marker of Pain and Distress After Acute Musculoskeletal Trauma

OBJECTIVES

The best available predictors of chronic pain development broadly encompass baseline metrics of cognition (ie, beliefs/expectations) about the trauma and resulting symptoms. In the context of musculoskeletal trauma, we have previously shown the Traumatic Injuries Distress Scale (TIDS) capable of risk-stratifying cohorts for chronic pain development. Here, we explore whether the physiological marker cortisol shows meaningful associations with cognitions predictive of pain outcomes.

METHODS

Data for these cross-sectional analyses were drawn from an observational study that recruited 130 participants presenting to the hospital with pain related to a recent noncatastrophic Musculoskeletal trauma. Cortisol was measured from the participant's hair, saliva, and blood. In addition to pain and distress questionnaires, metadata such as age, sex, body mass index (BMI), adverse childhood events, pretrauma stress levels, and pre-existing physical/psychological comorbidities were collected.

RESULTS

We found no significant associations between cortisol levels and pain or distress in isolation. When stratified by person-level variables, associations were revealed with distress (TIDS) in young age and low pretrauma stress subgroups (hair cortisol) and low BMI (blood cortisol). Through hierarchical regression analysis, we found the "cortisol X age" or "cortisol X stress" interaction terms significantly improved TIDS prediction beyond either variable in isolation (Age: ∆ R2 =15.1%; pretrauma stress: ∆ R2 =9.1%).

DISCUSSION

Our findings suggest that while linear correlations between pain-related distress and cortisol may be overly simplistic, certain person-level variables such as age, pretrauma stress, and BMI are worthy of consideration for experimental design or confounder characterization in future studies of pain and distress following musculoskeletal injuries especially when "trait" (hair) cortisol is the predictor variable.

The influence of burnout on cardiovascular disease: a systematic review and meta-analysis

Background

Burnout is a public health problem with various health consequences, among which cardiovascular disease is the most investigated but still under debate. Our objective was to conduct a systematic review and meta-analysis on the influence of burnout on cardiovascular disease.

Methods

Studies reporting risk (odds ratio, relative risk, and hazard ratio) of cardiovascular disease following burnout were searched in PubMed, PsycINFO, Cochrane, Embase, and ScienceDirect. We performed a random-effect meta-analysis stratified by type of cardiovascular disease and searched for putative influencing variables. We performed sensitivity analyses using the most adjusted models and crude risks.

Results

We included 25 studies in the systematic review and 9 studies in the meta-analysis (4 cross-sectional, 4 cohort, and 1 case-control study) for a total of 26,916 participants. Burnout increased the risk of cardiovascular disease by 21% (OR = 1.21, 95% CI 1.03 to 1.39) using the most adjusted risks and by 27% (OR = 1.27, 95% CI 1.10 to 1.43) using crude risks. Using stratification by type of cardiovascular disease and the most adjusted risks, having experienced burnout significantly increased the risk of prehypertension by 85% (OR = 1.85, 95% CI 1.00 to 2.70) and cardiovascular disease-related hospitalization by 10% (OR = 1.10, 95% CI 1.02 to 1.18), whereas the risk increase for coronary heart disease (OR = 1.79, 95% CI 0.79 to 2.79) and myocardial infarction (OR = 1.78, 95% CI 0.85 to 2.71) was not significant. Results were also similar using crude odds ratio. The risk of cardiovascular disease after a burnout was not influenced by gender. Insufficient data precluded other meta-regressions.

Conclusions

Burnout seems to increase the risk of cardiovascular disease, despite the few retrieved studies and a causality weakened by cross-sectional studies. However, numerous studies focused on the pathophysiology of cardiovascular risk linked to burnout, which may help to build a preventive strategy in the workplace.

Psycho-Neuroendocrinology in the Rehabilitation Field: Focus on the Complex Interplay between Stress and Pain

Chronic stress and chronic pain share neuro-anatomical, endocrinological, and biological features. However, stress prepares the body for challenging situations or mitigates tissue damage, while pain is an unpleasant sensation due to nociceptive receptor stimulation. When pain is chronic, it might lead to an allostatic overload in the body and brain due to the chronic dysregulation of the physiological systems that are normally involved in adapting to environmental challenges. Managing stress and chronic pain (CP) in neurorehabilitation presents a significant challenge for healthcare professionals and researchers, as there is no definitive and effective solution for these issues. Patients suffering from neurological disorders often complain of CP, which significantly reduces their quality of life. The aim of this narrative review is to examine the correlation between stress and pain and their potential negative impact on the rehabilitation process. Moreover, we described the most relevant interventions used to manage stress and pain in the neurological population. In conclusion, this review sheds light on the connection between chronic stress and chronic pain and their impact on the neurorehabilitation pathway. Our results emphasize the need for tailored rehabilitation protocols to effectively manage pain, improve treatment adherence, and ensure comprehensive patient care.

Understanding the mechanisms of disease modifying effects of aerobic exercise in people with Alzheimer's disease

Alzheimer's disease (AD) is a very disabling disease. Pathologically, it is characterized by the presence of amyloid plaques and neurofibrillary tangles in the brain that results in neurodegeneration. Its clinical manifestations include progressive memory impairment, language decline and difficulty in carrying out activities of daily living (ADL). The disease is managed using interventions such as pharmacological interventions and aerobic exercise. Use of aerobic exercise has shown some promises in reducing the risk of developing AD, and improving cognitive function and the ability to carry out both basic and instrumental ADL. Although, the mechanisms through which aerobic exercise improves AD are poorly understood, improvement in vascular function, brain glucose metabolism and cardiorespiratory fitness, increase in antioxidant capacity and haemoglobin level, amelioration of immune-related and inflammatory responses, modulation of concentration of circulating Neurotrophins and peptides and decrease in concentration of tau protein and cortisol level among others seem to be the possible mechanisms. Therefore, understanding these mechanisms is important to help characterize the dose and the nature of the aerobic exercise to be given. In addition, they may also help in finding ways to optimize other interventions such as the pharmacological interventions. However, more quality studies are needed to verify the mechanisms.

Adverse effects of early-life stress: focus on the rodent neuroendocrine system

Early-life stress is associated with a high prevalence of mental illnesses such as post-traumatic stress disorders, attention-deficit/hyperactivity disorder, schizophrenia, and anxiety or depressive behavior, which constitute major public health problems. In the early stages of brain development after birth, events such as synaptogenesis, neuron maturation, and glial differentiation occur in a highly orchestrated manner, and external stress can cause adverse long-term effects throughout life. Our body utilizes multifaceted mechanisms, including neuroendocrine and neurotransmitter signaling pathways, to appropriately process external stress. Newborn individuals first exposed to early-life stress deploy neurogenesis as a stress-defense mechanism; however, in adulthood, early-life stress induces apoptosis of mature neurons, activation of immune responses, and reduction of neurotrophic factors, leading to anxiety, depression, and cognitive and memory dysfunction. This process involves the hypothalamus-pituitary-adrenal axis and neurotransmitters secreted by the central nervous system, including norepinephrine, dopamine, and serotonin. The rodent early-life stress model is generally used to experimentally assess the effects of stress during neurodevelopment. This paper reviews the use of the early-life stress model and stress response mechanisms of the body and discusses the experimental results regarding how early-life stress mediates stress-related pathways at a high vulnerability of psychiatric disorder in adulthood.

Glucocorticoid and Adrenergic Receptor Distribution Across Human Organs and Tissues: A Map for Stress Transduction

OBJECTIVE

Psychosocial stress is transduced into disease risk through energy-dependent release of hormones from the hypothalamic-pituitary-adrenal and sympathetic-adrenal-medullary axes. The levels of glucocorticoid and adrenergic hormones, together with the sensitivity of tissues to their signaling, define stress responses. To understand existing pathways responsible for the psychobiological transduction of stressful experiences, we provide a quantitative whole-body map of glucocorticoid and adrenergic receptor (AR) expression.

METHODS

We systematically examined gene expression levels for the glucocorticoid receptor (GR), α- and β-ARs (AR-α1B, AR-α2B AR-β2, and AR-β3), across 55 different organs using the Human Protein Atlas and Human Proteome Map datasets. Given that mitochondria produce the energy required to respond to stress, we leveraged the Human Protein Atlas and MitoCarta3.0 data to examine the link between stress hormone receptor density and mitochondrial gene expression. Finally, we tested the functional interplay between GR activation and AR expression in human fibroblast cells.

RESULTS

The GR was expressed ubiquitously across all investigated organ systems, whereas AR subtypes showed lower and more localized expression patterns. Receptor co-regulation, meaning the correlated gene expression of multiple stress hormone receptors, was found between GR and AR-α1B, as well as between AR-α1B and AR-α2B. In cultured human fibroblasts, activating the GR selectively increased AR-β2 and AR-α1B expression. Consistent with the known energetic cost of stress responses, GR and AR expressions were positively associated with the expression of specific mitochondrial pathways.

CONCLUSIONS

Our results provide a cartography of GR and AR expression across the human body. Because stress-induced GR and AR signaling triggers energetically expensive cellular pathways involving energy-transforming mitochondria, the tissue-specific expression and co-expression patterns of hormone receptor subtypes may in part determine the resilience or vulnerability of different organ systems.

Microarray evidence that 8-cell human embryos express some hormone family members including oxytocin

OBJECTIVE

This study is to discover hormone pathways active in early cleaving human embryos.

METHODS

A list of 152 hormones and receptors were compiled to query the microarray database of mRNAs in 8-cell human embryos, two lines of human embryonic stem cells plus human fibroblasts before and after induced pluripotency.

RESULTS

Over half of the 152 hormones and receptors were silent on the arrays of all cell types, and more were detected at high or moderate levels on the 8-cell arrays than on the pluripotent cell or fibroblast arrays. Eight hormone family genes were uniquely detected at least 22-fold higher on the 8-cell arrays than the stem cell arrays: AVPI1, CCK, CORT, FSTL4, GIP, GPHA2, OXT, and PPY suggesting novel roles for these proteins in early development. Oxytocin was detected by pilot immunoassay in culture media collected from Day 3 embryos. Robust detection of CRHR1 and EPOR suggests the 8-cell embryo may be responsive to maternal CRH and EPO. The over-expression of POMC and GHITM suggests POMP peptide products may have undiscovered roles in early development and GHITM may contribute to mitochondrial remodeling. Under-detected on the 8-cell arrays at least tenfold were two key enzymes in steroid biosynthesis, DHCR24 and FDPS.

CONCLUSIONS

The 8-cell human embryo may be secreting oxytocin, which could stimulate its own progress down the fallopian tube as well as play a role in early neural precursor development. The 8-cell embryo does not synthesize reproductive steroid hormones. As previously reported for growth factor families, the early embryo over-expresses more hormones than hormone receptors.

Distress, multimorbidity, and complex multimorbidity among Chinese and Korean American older adults

BACKGROUND

Studies suggest that distress is associated with various health conditions such as hypertension, asthma, diabetes, and coronary heart disease. However, only few studies focused on Asian Americans and little is known about the association with multiple comorbidity.

METHODS

We conducted a cross-sectional analysis among 400 Chinese and Korean American participants (aged 50-75 years) of the STOP CRC randomized controlled trial. Perceived distress was assessed using the distress thermometer scale (range 0-10). Disease diagnosis was self-reported by the participants. Multimorbidity (MM) was defined as having ≥2 chronic conditions. Complex multimorbidity (CMM) was defined as having ≥3 of the following body system disorders: circulation disorder, endocrine-metabolic disorder, cancer, anxiety or depression, breathing problem, and other health problems. We performed logistic regression for CMM and Poisson regression with robust error variance for MM to estimate associations with distress, adjusting for potential confounders.

RESULTS

The mean age was 58.4 years and mean distress score was 3.65. One-unit increase in distress score was associated with a 1.22-fold increase in the odds of having CMM (95% CI: 1.04-1.42). The magnitude of association slightly increased after additional adjustment for socioeconomic factors and health insurance status (OR: 1.29; 95% CI: 1.10-1.52). Higher distress score was positively associated with MM but the association was only marginally significant (PR: 1.04; 95% CI: 0.99-1.10), adjusting for socioeconomic factors and health insurance status.

CONCLUSION

Our data suggest that higher perceived distress may be associated with simultaneous dysfunction of multiple distinct body systems among Chinese and Korean American older adults.

The Role of Pro-Opiomelanocortin Derivatives in the Development of Type 2 Diabetes-Associated Myocardial Infarction: Possible Links with Prediabetes

Myocardial infarction is a major contributor to CVD-related mortality. T2DM is a risk factor for MI. Stress activates the HPA axis, SNS, and endogenous OPS. These POMC derivatives increase the blood glucose and cardiovascular response by inhibiting the PI3K/AkT insulin signaling pathway and increasing cardiac contraction. Opioids regulate the effect of the HPA axis and SNS and they are cardioprotective. The chronic activation of the stress response may lead to insulin resistance, cardiac dysfunction, and MI. Stress and T2DM, therefore, increase the risk of MI. T2DM is preceded by prediabetes. Studies have shown that prediabetes is associated with an increased risk of MI because of inflammation, hyperlipidemia, endothelial dysfunction, and hypertension. The HPA axis is reported to be dysregulated in prediabetes. However, the SNS and the OPS have not been explored during prediabetes. The effect of prediabetes on POMC derivatives has yet to be fully explored and understood. The impact of stress and prediabetes on the cardiovascular response needs to be investigated. This study sought to review the potential impact of prediabetes on the POMC derivatives and pathways that could lead to MI.