HPA axis regulation and epigenetic programming of immune-related genes in chronically stressed and non-stressed mid-life women

Long-term stress exposure, cortisol level and cardiovascular activity and reactivity: Observations in patients with fibromyalgia

Previous research suggested that exposure to long-lasting or repeated laboratory stressors may lead to rearrangement of cardiovascular control, with a shift of regulation mechanisms from dominant cardiac to dominant vascular influences between the early and late response phases, respectively. This study investigated whether similar rearrangement occurs during life stress accompanying chronic disease by analyzing also associations between cortisol level and cardiovascular variables in patients with fibromyalgia (FM). In 47 women with FM and 36 healthy women (HW), cardiovascular recordings were taken during active body posture changes (sitting, lying down, and standing). Moreover, hair cortisol concentration (HCC) was obtained. During standing, which involved orthostatic challenge, FM patients showed higher total peripheral resistance (TPR) but lower stroke volume (SV), cardiac output (CO), and baroreflex sensitivity than HW. During sitting and lying down, TPR was more closely associated with blood pressure (BP) than CO in FM patients; in contrast, CO was more closely associated with BP than TPR in HW. HCC correlated positively with TPR and BP in FM patients, but negatively with TPR and BP and positively with SV and CO in HW. Results suggest that chronic disease-related stress is associated with alterations in cardiovascular regulation toward greater involvement of vascular than cardiac mechanisms in BP control. Stress-related cortisol release may contribute to the long-term rearrangement of autonomic regulation. At the behavioral level, the dominance of vascular over cardiovascular control may relate to reduced somatic mobilization during an active fight-flight response in favor of passive and behaviorally immobile coping.

Microbiota-immune-brain interactions: A new vision in the understanding of periodontal health and disease

This review highlights the significance of interactions between the microbiota, immune system, nervous and hormonal systems, and the brain on periodontal health and disease. Microorganisms in the microbiota, immune cells, and neurons communicate via homeostatic nervous and hormonal systems, regulating vital body functions. By modulating pro-inflammatory and anti-inflammatory adaptive immune responses, these systems control the composition and number of microorganisms in the microbiota. The strength of these brain-controlled responses is genetically determined but is sensitive to early childhood stressors, which can permanently alter their responsiveness via epigenetic mechanisms, and to adult stressors, causing temporary changes. Clinical evidence and research with humans and animal models indicate that factors linked to severe periodontitis enhance the responsiveness of these homeostatic systems, leading to persistent hyperactivation. This weakens the immune defense against invasive symbiotic microorganisms (pathobionts) while strengthening the defense against non-invasive symbionts at the gingival margin. The result is an increased gingival tissue load of pathobionts, including Gram-negative bacteria, followed by an excessive innate immune response, which prevents infection but simultaneously destroys gingival and periodontal tissues. Thus, the balance between pro-inflammatory and anti-inflammatory adaptive immunity is crucial in controlling the microbiota, and the responsiveness of brain-controlled homeostatic systems determines periodontal health.

Association of hair cortisol concentration with brain-derived neurotrophic factor gene methylation: The role of sex as a moderator

Hair cortisol concentration (HCC) reflects the long-term activity of the hypothalamus-pituitary-adrenal (HPA) axis in response to stress. Brain-derived neurotrophic factor DNA methylation (BDNF DNAM) may affect HCC, and sex and Val66Met may contribute to this association. Thus, the aim of this study was to investigate the associations between HCC and Brain-derived neurotrophic factor (BDNF) DNAM, and the moderating effects of Val66Met and sex. We recruited 191 healthy young participants (96 women, mean age 23.0 ± 2.6 years) and collected body samples to evaluate HCC, and to determine BDNF DNAM and Val66Met genotypes. We analyzed the effects of BDNF DNAM, sex, and Val66Met on HCC. We also evaluated the associations between BDNF DNAM and HCC in groups separated by sex and genotypes. We found a marked association of BDNF DNAM with HCC across men and women. After dividing the data by sex, a positive correlation of HCC with BDNF DNAM was found only in women. There was no substantial moderation effect of Val66Met genotypes on the association between BDNF DNAM and HCC. Therefore, BDNF DNAM was found to have positive association with HCC only in healthy young women, indicating that sex moderates the association of BDNF DNAM with long-term HPA axis activity.

Oxidative stress in the brain-lung crosstalk: cellular and molecular perspectives

Oxidative stress is caused by an imbalance between the production of reactive oxygen species (ROS) and the body's ability to counteract their harmful effects, playing a key role in the pathogenesis of brain and lung-related diseases. This review comprehensively examines the intricate mechanisms by which oxidative stress influences cellular and molecular pathways, contributing to neurodegenerative, cardiovascular, and respiratory disorders. Emphasizing the detrimental effects on both brain and lung health, we discuss innovative diagnostic biomarkers, such as 8-hydroxy-2'-deoxyguanosine (8-OHdG), and the potential of antioxidant therapies. For these topics, we provide insights into future research directions in the field of oxidative stress treatment, including the development of personalized treatment approaches, the discovery and validation of novel biomarkers, and the development of new drug delivery systems. This review not only provides a new perspective on understanding the role of oxidative stress in brain and lung-related diseases but also offers new insights for future clinical treatments.

Abnormal DNA methylation within HPA-axis genes years after paediatric critical illness

BACKGROUND

Critically ill children suffer from impaired physical/neurocognitive development 2 years later. Glucocorticoid treatment alters DNA methylation within the hypothalamus-pituitary-adrenal (HPA) axis which may impair normal brain development, cognition and behaviour. We tested the hypothesis that paediatric-intensive-care-unit (PICU) patients, sex- and age-dependently, show long-term abnormal DNA methylation within the HPA-axis layers, possibly aggravated by glucocorticoid treatment in the PICU, which may contribute to the long-term developmental impairments.

RESULTS

In a pre-planned secondary analysis of the multicentre PEPaNIC-RCT and its 2-year follow-up, we identified differentially methylated positions and differentially methylated regions within HPA-axis genes in buccal mucosa DNA from 818 former PICU patients 2 years after PICU admission (n = 608 no glucocorticoid treatment; n = 210 glucocorticoid treatment) versus 392 healthy children and assessed interaction with sex and age, role of glucocorticoid treatment in the PICU and associations with long-term developmental impairments. Adjusting for technical variation and baseline risk factors and correcting for multiple testing (false discovery rate < 0.05), former PICU patients showed abnormal DNA methylation of 26 CpG sites (within CRHR1, POMC, MC2R, NR3C1, FKBP5, HSD11B1, SRD5A1, AKR1D1, DUSP1, TSC22D3 and TNF) and three DNA regions (within AVP, TSC22D3 and TNF) that were mostly hypomethylated. These abnormalities were sex-independent and only partially age-dependent. Abnormal methylation of three CpG sites within FKBP5 and one CpG site within SRD5A1 and AKR1D1 was partly attributable to glucocorticoid treatment during PICU stay. Finally, abnormal methylation within FKBP5 and AKR1D1 was most robustly associated with long-term impaired development.

CONCLUSIONS

Two years after critical illness in children, abnormal methylation within HPA-axis genes was present, predominantly within FKBP5 and AKR1D1, partly attributable to glucocorticoid treatment in the PICU, and explaining part of the long-term developmental impairments. These data call for caution regarding liberal glucocorticoid use in the PICU.

Childhood maltreatment and risk of endocrine diseases: an exploration of mediating pathways using sequential mediation analysis

BACKGROUND

Adverse childhood experiences (ACEs), including childhood maltreatment, have been linked with increased risk of diabetes and obesity during adulthood. A comprehensive assessment on the associations between childhood maltreatment and all major endocrine diseases, as well as the relative importance of different proposed mechanistic pathways on these associations, is currently lacking.

METHODS

Based on the UK Biobank, we constructed a cohort including 151,659 participants with self-reported data on childhood maltreatment who were 30 years of age or older on/after January 1, 1985. All participants were followed from the index date (i.e., January 1, 1985, or their 30th birthday, whichever came later) until the first diagnosis of any or specific (12 individual diagnoses and 9 subtypes) endocrine diseases, death, or the end of follow-up (December 31, 2019), whichever occurred first. We used Cox models to examine the association of childhood maltreatment, treated as continuous (i.e., the cumulative number of experienced childhood maltreatment), ordinal (i.e., 0, 1 and ≥ 2), or binary (< 2 and ≥ 2) variable, with any and specific endocrine diseases, adjusted for multiple covariates. We further examined the risk of having multiple endocrine diseases using Linear or Logistic Regression models. Then, sequential mediation analyses were performed to assess the contribution of four possible mechanisms (i.e., suboptimal socioeconomic status (SES), psychological adversities, unfavorable lifestyle, and biological alterations) on the observed associations.

RESULTS

During an average follow-up of 30.8 years, 20,885 participants received a diagnosis of endocrine diseases. We observed an association between the cumulative number of experienced childhood maltreatment and increased risk of being diagnosed with any endocrine disease (adjusted hazard ratio (HR) = 1.10, 95% confidence interval 1.09-1.12). The HR was 1.26 (1.22-1.30) when comparing individuals ≥ 2 with those with < 2 experienced childhood maltreatment. We further noted the most pronounced associations for type 2 diabetes (1.40 (1.33-1.48)) and hypothalamic-pituitary-adrenal (HPA)-axis-related endocrine diseases (1.38 (1.17-1.62)), and the association was stronger for having multiple endocrine diseases, compared to having one (odds ratio (95% CI) = 1.24 (1.19-1.30), 1.35 (1.27-1.44), and 1.52 (1.52-1.53) for 1, 2, and ≥ 3, respectively). Sequential mediation analyses showed that the association between childhood maltreatment and endocrine diseases was consistently and most distinctly mediated by psychological adversities (15.38 ~ 44.97%), while unfavorable lifestyle (10.86 ~ 25.32%) was additionally noted for type 2 diabetes whereas suboptimal SES (14.42 ~ 39.33%) for HPA-axis-related endocrine diseases.

CONCLUSIONS

Our study demonstrates that adverse psychological sequel of childhood maltreatment constitutes the main pathway to multiple endocrine diseases, particularly type 2 diabetes and HPA-axis-related endocrine diseases. Therefore, increased access to evidence-based mental health services may also be pivotal in reducing the risk of endocrine diseases among childhood maltreatment-exposed individuals.

Immune Homeostasis: A Novel Example of Teamwork

All living organisms must maintain homeostasis to survive, reproduce, and pass their traits on to the next generation. If homeostasis is not maintained, it can result in various diseases and ultimately lead to death. Physiologists have coined the term "homeostasis" to describe this process. With the emergence of immunology as a separate branch of medicine, the concept of immune homeostasis has been introduced. Maintaining immune homeostasis is crucial to support overall homeostasis through different immunological and non-immunological routes. Any changes in the immune system can lead to chronic inflammatory or autoimmune diseases, immunodeficiency diseases, frequent infections, and cancers. Ongoing scientific advances are exploring new avenues in immunology and immune homeostasis maintenance. This chapter introduces the concept of immune homeostasis and its maintenance through different mechanisms.

Adverse Childhood Experiences Predict Diurnal Cortisol Throughout Gestation

OBJECTIVE

Adverse childhood experiences (ACEs) are associated with negative prenatal and perinatal health outcomes and may, via these pathways, have intergenerational effects on child health and development. We examine the impact of ACEs on maternal salivary cortisol, a key measure of prenatal biology previously linked with pregnancy-related health outcomes.

METHODS

Leveraging assessments across three trimesters, we used linear mixed-effects models to analyze the influence of ACEs on maternal prenatal diurnal cortisol patterns in a diverse cohort of pregnant women (analytic sample, n = 207). Covariates included comorbid prenatal depression, psychiatric medications, and sociodemographic factors.

RESULTS

Maternal ACEs were significantly associated with flatter diurnal cortisol slopes (i.e., less steep decline), after adjusting for covariates, with effects consistent across gestation (estimate = 0.15, standard error = 0.06, p = .008).

CONCLUSIONS

ACEs experienced before pregnancy may have a robust and lasting influence on maternal prenatal hypothalamic-pituitary-adrenal activity throughout gestation, a key biological marker associated with perinatal and child health outcomes. The findings suggest one route of intergenerational transmission of early adverse experiences and underscore the potential value of assessing prepregnancy adverse experiences for promoting perinatal and maternal and child health.

Associations of SLC6A4 methylation with salivary cortisol, salivary alpha-amylase, and subjective stress in everyday life

Dysregulations of the hypothalamic-pituitary-adrenal (HPA) and sympatho-adrenal medullary (SAM) axis are associated with mental and somatic illness. However, there is lack of knowledge regarding the molecular mechanisms underlying these effects. Epigenetic states in the serotonin transporter gene (SLC6A4) were shown to be associated with stress in various forms. We hypothesized that levels of DNA methylation (DNAm) of SLC6A4 would be associated with altered SAM- and HPA regulation in daily life. N = 74 healthy persons participated in the study. An ecological momentary assessment (EMA) approach was used to assess indicators of stress in daily life. Each day included six concurrent assessments of saliva, to quantify cortisol (sCort; HPA axis) and alpha-amylase (sAA; SAM axis), and to assess self-reports on subjective stress. To assess SLC6A4 DNAm, peripheral blood was drawn and analyzed via bisulfite pyrosequencing. All data were assessed in two waves three months apart, each including two days of EMA and the assessment of SLC6A4 DNAm. Data were analyzed using multilevel models. On the between-person level, higher average levels of SLC6A4 DNAm were associated with higher average levels of sAA, but not with average levels of sCort. On the within-person level, higher levels of SLC6A4 DNAm were associated with lower levels of sAA and sCort. There were no associations of subjective stress with SLC6A4 DNAm. The results help to clarify the association between environmental stress and stress axes regulation, pointing towards an important role of differential within- and between-person effects of SLC6A4 DNAm, which might shape this association.

On the road to resilience: Epigenetic effects of meditation

Many environmental and lifestyle related factors may influence the physiology of the brain and body by acting on fundamental molecular pathways, such as the hypothalamus-pituitary-adrenal axis (HPA) and the immune system. For example, stressful conditions created by adverse early-life events, unhealthy habits and low socio-economic status may favor the onset of diseases linked to neuroendocrine dysregulation, inflammation and neuroinflammation. Beside pharmacological treatments used in clinical settings, much attention has been given to complementary treatments such as mind-body techniques involving meditation that rely on the activation of inner resources to regain health. At the molecular level, the effects of both stress and meditation are elicited epigenetically through a set of mechanisms that regulate gene expression as well as the circulating neuroendocrine and immune effectors. Epigenetic mechanisms constantly reshape genome activities in response to external stimuli, representing a molecular interface between organism and environment. In the present work, we aimed to review the current knowledge on the correlation between epigenetics, gene expression, stress and its possible antidote, meditation. After introducing the relationship between brain, physiology, and epigenetics, we will proceed to describe three basic epigenetic mechanisms: chromatin covalent modifications, DNA methylation and non-coding RNAs. Subsequently, we will give an overview of the physiological and molecular aspects related to stress. Finally, we will address the epigenetic effects of meditation on gene expression. The results of the studies reported in this review demonstrate that mindful practices modulate the epigenetic landscape, leading to increased resilience. Therefore, these practices can be considered valuable tools that complement pharmacological treatments when coping with pathologies related to stress.

Perillyl alcohol attenuates chronic restraint stress aggravated dextran sulfate sodium-induced ulcerative colitis by modulating TLR4/NF-κB and JAK2/STAT3 signaling pathways

BACKGROUND

Ulcerative colitis (UC) is the most prevalent chronic inflammatory immune bowel disease. The modernization of lifestyle accompanied by the stress to cope with the competition has resulted in a new range of complications where stress became a critical contributing factor for many diseases, including UC. Hence there is an urgent need to develop a dual role in curtailing both systemic and neuroinflammation. Perillyl alcohol (POH) is a natural essential oil found in lavender, peppermint, cherries etc and has been widely studied for its strong anti-inflammatory, antioxidant and anti-stress properties.

HYPOTHESIS/PURPOSE

POH regulates the various inflammatory signaling cascades involved in chronic inflammation by inhibiting farnesyltransferase  enzyme. Several studies reported that POH could inhibit the phosphorylation of  NF-κB, STAT3 and promote the endogenous antioxidant enzymes like Nrf2 via farnesyltransferase enzyme inhibition.  Also, the effects of POH against UC is not known yet. Thus, this study aims to explore the anti-ulcerative properties of POH on stress aggravated ulcerative colitis in C57BL/6 mice.

METHODS

Ulcerative colitis was induced by duel exposure of chronic restraint stress (day 1 to day 28) and 2.5% dextran sulphate sodium (day8 to day14) in mice. POH treatment 100 and 200 mg/kg was administred from day14 ti day28 following oral route of administration. Disease activity index, colonoscopy, western blot analysis and histological analysis, neurotransmitter analysis and Gene expression studies were perofomerd to asses the anti-colitis effects of POH.

RESULTS

The treatment reversed the oxidative stress and inflammatory response by inhibiting TLR4/NF-kB pathway, and IL-6/JAK2/STAT3 pathway in both isolated mice colons and brains. The inhibition of these pathways resulted in a decrease in pro-inflammatory cytokines like IL-6, IL-1β and TNF-α. The treatment improved the physiological and histological changes with decreased ulcerations as examined by colonic endoscopy and Haematoxylin and Eosin staining. The treatment also improved the behavior response as it increased mobility time which was reduced by chronic restrained stress. This was due to increased satiety neurotransmitters like dopamine and serotonin and decreased cortisol in mice brains.

CONCLUSION

These results infer that POH has significant anti-colitis activity on chronic restraint stress aggravated DSS-induced UC in mice.

Cause or consequence? Understanding the role of cortisol in the increased inflammation observed in depression

Glucocorticoids such as cortisol are a class of steroid hormones that play an important role in co-ordinating the body's response to stress. Elevated cortisol levels and increased inflammation have frequently been reported in patients with depression. The currently accepted "glucocorticoid resistance" model posits this increased inflammation as a consequence of reduced sensitivity to cortisol's putative anti-inflammatory action. However, opposing evidence has accumulated that supports a more recent model, which instead proposes that cortisol possesses immune potentiating properties and may thus directly cause the increased inflammation seen in depression. Despite all of this, a clear explanation of the neuroendocrine mechanism that contributes to the development of depression is still lacking and thus requires further investigation in improved future studies.

Role of Microbiota-Gut-Brain Axis in Regulating Dopaminergic Signaling

Dopamine is a neurotransmitter that plays a critical role both peripherally and centrally in vital functions such as cognition, reward, satiety, voluntary motor movements, pleasure, and motivation. Optimal dopamine bioavailability is essential for normal brain functioning and protection against the development of neurological diseases. Emerging evidence shows that gut microbiota have significant roles in maintaining adequate concentrations of dopamine via intricate, bidirectional communication known as the microbiota-gut-brain axis. The vagus nerve, immune system, hypothalamus–pituitary–adrenal axis, and microbial metabolites serve as important mediators of the reciprocal microbiota-gut-brain signaling. Furthermore, gut microbiota contain intrinsic enzymatic activity that is highly involved in dopamine metabolism, facilitating dopamine synthesis as well as its metabolite breakdown. This review examines the relationship between key genera of gut microbiota such as Prevotella, Bacteroides, Lactobacillus, Bifidobacterium, Clostridium, Enterococcus, and Ruminococcus and their effects on dopamine. The effects of gut dysbiosis on dopamine bioavailability and the subsequent impact on dopamine-related pathological conditions such as Parkinson’s disease are also discussed. Understanding the role of gut microbiota in modulating dopamine activity and bioavailability both in the periphery and in the central nervous system can help identify new therapeutic targets as well as optimize available methods to prevent, delay, or restore dopaminergic deficits in neurologic and metabolic disorders.

Psychological intervention to treat distress: An emerging frontier in cancer prevention and therapy

Psychological distress, such as chronic depression and anxiety, is a topical problem. In the context of cancer patients, prevalence rates of psychological distress are four-times higher than in the general population and often confer worse outcomes. In addition to evidence from epidemiological studies confirming the links between psychological distress and cancer progression, a growing body of cellular and molecular studies have also revealed the complex signaling networks which are modulated by psychological distress-derived chronic stress during cancer progression. In this review, aiming to uncover the intertwined networks of chronic stress-driven oncogenesis and progression, we summarize physiological stress response pathways, like the HPA, SNS, and MGB axes, that modulate the release of stress hormones with potential carcinogenic properties. Furthermore, we discuss in detail the mechanisms behind these chronic stimulations contributing to the initiation and progression of cancer through direct regulation of cancer hallmarks-related signaling or indirect promotion of cancer risk factors (including obesity, disordered circadian rhythms, and premature senescence), suggesting a novel research direction into cancer prevention and therapy on the basis of psychological interventions.

A Glimpse Into the Sexual Dimorphisms in Major Depressive Disorder Through Epigenetic Studies

Depression is an umbrella term used to describe a mood disorder with a broad spectrum of symptoms including a persistent feeling of sadness, loss of interest, and deficits in social behavior. Epigenetic research bridges the environmental and genetic landscape and has the potential to exponentially improve our understanding of such a complex disorder. Depression is also a sexually dimorphic disorder and variations exist within epigenetic modification sites between sexes. These sex-specific mediators may impact behavioral symptomology and could serve as therapeutic targets for treatments to improve behavioral deficits. This mini review will focus on the social behavior perspective of depression and specifically explore the sexually different epigenetic modifications on depression.

Neutrophil-to-lymphocyte ratio is a powerful predictor of adult patients with acute respiratory distress syndrome who might benefit from corticosteroid therapy

BACKGROUND

There is no convincing pharmacological treatment for patients withacute respiratory distress syndrome (ARDS). The efficacy of corticosteroids in ARDS patients remains controversial. Neutrophil-to-Lymphocyte Ratio (NLR) has displayed as a good biomarker for inflammation and immune status, and thus a prognostic marker in some critical patients of ARDS. In this study, we hypothesized that NLR could also serve as an indicator for the efficacy of corticosteroid therapy in ARDS patients.

METHODS

Subjects included in this retrospective cohort study with ARDS patients who were admitted to an academic hospital in Wuhan, China, from May 1st, 2020 to April 20th, 2021. Multivariable logisitic regression model was used to evaluate risk factors of 30-day in-hospital mortality and ventilator-free days. Multi-Cox regression model was used to assess the efficacy of corticosteroid treatment in terms of NLR cutoff value.

RESULTS

Among the 357 patients in our study, 89 (24.9%) had NLR≥14.35 and 268 (75.1%) had NLR<14.35. Among them, 53 patients with NLR≥14.35 (58.9%) received corticosteroids and 99 patients with NLR<14.35 (37.1%) received corticosteroids. Post-adjustment analysis (by APACHE II score and age) revealed that corticosteroid treatment was associated with a decreased risk of 30-day mortality in the NLR≥14.35 group but with an increased risk of death in the NLR<14.35 group. Use of corticosteroid in NLR≥14.35 group significantly increased ventilator-free days (7.0 vs. 13.0, P<0.001).

CONCLUSION

NLR may be used to help identify ARDS patients who may benefit from corticosteroid treatment. Large-sized randomized controlled trials are warranted to determine the optimal cutoff value of NLR.

A Discovery that Reframes the Whole of Global Healthcare in the 21st Century: The Importance of the Imprintome

Within the genome exists a specific subset of genes whose expression is controlled by epigenetic marks. These tags can be modified by lifestyle factors including diet, behavior, environment and social interactions. Differences in genetic expression, despite identical genes, is explained in part through metastable epialleles-alleles that, while genetically indistinguishable, are variably expressed as a function of epigenetic modification. As a group, these metastable epialleles have been given a unique descriptive name: the imprintome. This breakthrough in understanding genetic expression has led to a wider recognition that our genes are fundamentally controlled at two levels. One is the hardware of the genetic code, which is modified slowly by natural selection through mutational changes in the genome over centuries of time. The other is the software that controls the expression of our genetic code, converting nucleotide sequences into phenotype in response to the imprinting of our epigenome. Acting as a rapid translator for real time changes, the imprintome responds to environmental and lifestyle inputs by genomic methylation and histone modifications that affect promoter accessibility and transcription factor activity. In application, this understanding of the plasticity of the imprintome necessitates a rethinking of both health and disease states. It's a concept that cuts across all forms of healthcare: physical, metabolic, and cognitive-behavioral interventions. But at the same time, it is an aggregating concept-one that brings disciplines together to collaborate on the personalization of health and the delivery of truly individualized care. This article reviews the development of the concept of the imprintome, as well as clinical studies supporting its importance as a potential driver of change in global health care.