Chronic stress and age-related increases in the proinflammatory cytokine IL-6

Associations of dietary patterns and perceived stress with memory deficits in patients with heart failure

This study aimed to examine the relationships between dietary patterns and perceived stress with memory deficits in 291 patients with heart failure aged 45-85 years. A total of 142 (48.8%) patients reported memory deficit. Three dietary patterns were identified by K-means clustering: nut-fruit-dairy, meat-processed, and traditional (high intake of cereals) diets. Compared to the traditional diet, the nut-fruit-dairy diet and meat-processed diet were associated with lower levels of deficits in short-term memory, delayed memory, and overall memory. What's more, perceived stress was positively associated with deficits in short-term memory and overall memory, but the association was only found in patients adhering to the traditional diet using stratified analyses. Our findings suggest that adhering to a healthy diet may be conducive to improving deficits in short-term memory, delayed memory, and overall memory, while also buffering the adverse association between perceived stress and deficits in short-term memory and overall memory.

Estimating survival in data-driven phenotypes of mental health symptoms and peripheral biomarkers: A prospective study

Background

Chronic psychological stress has widespread implications, including heightened mortality risk, mental and physical health conditions, and socioeconomic consequences. Stratified precision psychiatry shows promise in mitigating these effects by leveraging clinical heterogeneity to personalize interventions. However, little attention has been given to patient self-report.

Methods

We addressed this by combining stress-related self-report measures with peripheral biomarkers in a latent profile analysis and survival model. The latent profile models were estimated in a representative U.S. cohort (n = 1255; mean age = 57 years; 57% female) and cross-validated in Tokyo, Japan (n = 377; mean age = 55 years; 56% female).

Results

We identified three distinct groups: "Good Mental Health", "Poor Mental Health", and "High Inflammation". Compared to the "Good Mental Health" group, the "High Inflammation" and "Poor Mental Health" groups had an increased risk of mortality, but did not differ in mortality risk from each other.

Conclusions

This study emphasizes the role of patient self-report in stratified psychiatry.

Moving toward affective immunology: Legacy and future directions

The term "affective immunology" has recently been used to denote a field focused on the interplay between affective processes (including mood states, specific emotions, and regulatory processes) and various aspects of immune function. The overarching goals of this commentary are a) to provide historical underpinnings of this field with a focus on the profound impact of the work of Janice Kiecolt-Glaser, who is further honored in this special issue, b) to review important off-shoots of her legacy work in this domain, and c) to highlight important future directions for the field. Kiecolt-Glaser's work laid much of the foundation for affective immunology, with groundbreaking research related to depression, hostility and dyadic interactions, loneliness, and other affective patterns, often in the context of holistic models, novel experimental designs, and interventions. Her former mentees (and many of their mentees) have carried on her legacy in these domains, in ways that continue to advance appreciation of how affective processes relate to immune function. There are numerous remaining questions for the field to pursue, including better understanding of the role of emotion regulation, emotional reactivity and recovery, restorative processes, affective variability, and developmental and dynamic social processes. Such work will require greater use of longitudinal and within-person approaches and/or examination of processes in daily life, as well as models that account for interactive and reciprocal processes and which integrate behavior, social context, sociocultural factors, individual differences, and other aspects of health. As more work in these domains continues, building on Kiecolt-Glaser's rich legacy, we move toward the emergence of affective immunology as an important subfield in the domain of psychoneuroimmunology, one which will offer more nuanced understanding of the role of affective processes in immune health.

Neuroimmune crosstalk : How mental stress fuels vascular inflammation

Cardiovascular diseases are the leading cause of death worldwide. Pathophysiologically, metabolic and inflammatory processes contribute substantially to the development and progression of cardiovascular diseases. Over the past decade, the role of disease-propagating inflammatory processes has been strengthened and reframed, leading to trials testing anti-inflammatory drugs for the treatment of atherosclerosis and its complications. Despite these achievements, further research in both pre-clinical and clinical studies is warranted to explore new targets, to better identify responders, and to refine therapy strategies to combat inflammation in human disease. Environmental disturbances, so-called lifestyle-associated cardiovascular risk factors, greatly alter the immune system in general and leukocytes in particular, thus affecting the progression of atherosclerosis. Epidemiological studies have shown that exposure to mental stress can be closely linked to the occurrence of cardiovascular disease. Here, we describe how acute and chronic mental stress alter the immune system via neuroimmune interactions, thereby modifying vascular inflammation. In addition, we identify gaps that still need to be addressed in the future.

Apple polysaccharide improves age-matched cognitive impairment and intestinal aging through microbiota-gut-brain axis

The Apple polysaccharides (AP), extracted from the fruit of apple, has been used to treat multiple pathological diseases. In this study, we evaluated the effects of AP on cognitive impairment and intestinal aging in naturally aging mice. As a result, it was found that AP could improve spatial learning and memory impairment in aging mice through the Morris water maze experiment. Additionally, AP intervention can upregulate the expression of nerve growth factor (BDNF), postsynaptic marker (PSD95), and presynaptic marker (SYP) proteins. Moreover, AP can enhance total antioxidant capacity, reduce the level of pro-inflammatory cytokine, and inhibit the activation of the NF-κB signaling pathway, exerting anti-inflammatory and antioxidant functions. And the administration of AP restored intestinal mucosal barrier function, reduced the expression of aging and apoptosis related proteins. The administration of AP also altered the gut microbiota of mice. At the genus level, AP decreased the abundance of Helicobacter and Bilophila, while increased the abundance of Lactobacillus and Bacteroides. In summary, these data demonstrate that AP treatment can alleviate cognitive impairment, oxidative stress, and inflammatory reactions, repair the intestinal mucosal barrier, reduce intestinal aging, and alter specific microbial characteristics, ultimately improving the health of the elderly.

Morphologic, cytometric, quantitative transcriptomic and functional characterisation provide insights into the haemocyte immune responses of Pacific abalone (Haliotis discus hannai)

In recent years, the abalone aquaculture industry has been threatened by the bacterial pathogens. The immune responses mechanisms underlying the phagocytosis of haemocytes remain unclear in Haliotis discus hannai. It is necessary to investigate the immune mechanism in response to these bacterial pathogens challenges. In this study, the phagocytic activities of haemocytes in H. discus hannai were examined by flow cytometry combined with electron microscopy and transcriptomic analyses. The results of Vibrio parahaemolyticus, Vibrio alginolyticus and Staphylococcus aureu challenge using electron microscopy showed a process during phagosome formation in haemocytes. The phagocytic rate (PP) of S. aureus was higher than the other five foreign particles, which was about 63%. The PP of Vibrio harveyi was about 43%, the PP peak of V. alginolyticus in haemocyte was 63.7% at 1.5 h. After V. parahaemolyticus and V. alginolyticus challenge, acid phosphatase, alkaline phosphatase, total superoxide dismutase, lysozyme, total antioxidant capacity, catalase, nitric oxide synthase and glutathione peroxidase activities in haemocytes were measured at different times, differentially expressed genes (DEGs) were identified by quantitative transcriptomic analysis. The identified DEGs after V. parahaemolyticus challenge included haemagglutinin/amebocyte aggregation factor-like, supervillin-like isoform X4, calmodulin-like and kyphoscoliosis peptidase-like; the identified DEGs after V. alginolyticus challenge included interleukin-6 receptor subunit beta-like, protein turtle homolog B-like, rho GTPase-activating protein 6-like isoform X2, leukocyte surface antigen CD53-like, calponin-1-like, calmodulin-like, troponin C, troponin I-like isoform X4, troponin T-like isoform X18, tumor necrosis factor ligand superfamily member 10-like, rho-related protein racA-like and haemagglutinin/amebocyte aggregation factor-like. Some immune-related KEGG pathways were significantly up-regulated or down-regulated after challenge, including thyroid hormone synthesis, Th17 cell differentiation signalling pathway, focal adhesion, melanogenesis, leukocyte transendothelial migration, inflammatory mediator regulation of TRP channels, ras signalling pathway, rap1 signalling pathway. This study is the first step towards understanding the H. discus hannai immune system by adapting several tools to gastropods and providing a first detailed morpho-functional study of their haemocytes.

Mapping pathways to neuronal atrophy in healthy, mid-aged adults: From chronic stress to systemic inflammation to neurodegeneration?

Growing evidence implicates systemic inflammation in the loss of structural brain integrity in natural ageing and disorder development. Chronic stress and glucocorticoid exposure can potentiate inflammatory processes and may also be linked to neuronal atrophy, particularly in the hippocampus and the human neocortex. To improve understanding of emerging maladaptive interactions between stress and inflammation, this study examined evidence for glucocorticoid- and inflammation-mediated neurodegeneration in healthy mid-aged adults. N = 169 healthy adults (mean age = 39.4, 64.5% female) were sampled from the general population in the context of the ReSource Project. Stress, inflammation and neuronal atrophy were quantified using physiological indices of chronic stress (hair cortisol (HCC) and cortisone (HEC) concentration), systemic inflammation (interleukin-6 (IL-6), high-sensitive C-reactive protein (hs-CRP)), the systemic inflammation index (SII), hippocampal volume (HCV) and cortical thickness (CT) in regions of interest. Structural equation models were used to examine evidence for pathways from stress and inflammation to neuronal atrophy. Model fit indices indicated good representation of stress, inflammation, and neurological data through the constructed models (CT model: robust RMSEA = 0.041, robust χ2 = 910.90; HCV model: robust RMSEA <0.001, robust χ2 = 40.95). Among inflammatory indices, only the SII was positively associated with hair cortisol as one indicator of chronic stress (β = 0.18, p < 0.05). Direct and indirect pathways from chronic stress and systemic inflammation to cortical thickness or hippocampal volume were non-significant. In exploratory analysis, the SII was inversely related to mean cortical thickness. Our results emphasize the importance of considering the multidimensionality of systemic inflammation and chronic stress, with various indicators that may represent different aspects of the systemic reaction. We conclude that inflammation and glucocorticoid-mediated neurodegeneration indicated by IL-6 and hs-CRP and HCC and HEC may only emerge during advanced ageing and disorder processes, still the SII could be a promising candidate for detecting associations between inflammation and neurodegeneration in younger and healthy samples. Future work should examine these pathways in prospective longitudinal designs, for which the present investigation serves as a baseline.

Bidirectional relationship between C-reactive protein and depressive symptoms considering cumulative effect among Chinese middle-aged and older adults

Introduction

Research examining the bidirectional relationship between C-reactive protein (CRP) and depressive symptoms, while accounting for cumulative effect of repeated episodes of CRP or depressive symptoms, is currently deficient in non-Western populations.

Methods

A nationally representative population-based cohort data from the Chinese Health and Retirement Longitudinal Study (CHARLS) was utilized. In bi-directional analysis, we considered both single determinations and two successive determinations of CRP or depressive symptoms. Multivariate logistic regression assessed the association between elevated CRP levels at baseline or repeated episodes of CRP elevations over two successive determinations and subsequent elevated depressive symptoms, and vice versa.

Results

Although single determinations of CRP or depressive symptoms yielded non-significant results in both directions, full multivariate models, adjusting for baseline depressive symptoms, socio-demographic characteristics, health-related behaviors, metabolic measures, and health status, revealed a significantly positive association based on two successive determinations of CRP or depressive symptoms. This significant association was observed between cumulative effects of sustained CRP elevations over two successive determinations (2 vs. 0) and subsequent elevated depressive symptoms (OR=1.58; 95% CI: 1.15 to 2.17) and between cumulative effect of repeated episodes of depression (2 vs. 0) and later elevated CRP (OR=1.26; 95% CI: 1.02 to 1.56). Furthermore, sex-stratified analyses confirmed the robustness of these relationships.

Conclusion

There are bidirectional associations between depressive symptoms and CRP, driven by the cumulative effect of repeated episodes of CRP or depressive symptoms among middle-aged and older Chinese adults. These findings hold significant clinical implications, highlighting the potential of both anti-inflammatory and anti-depression approaches.

Immunosenescence and Inflammation in Chronic Obstructive Pulmonary Disease: A Systematic Review

Background/Objectives: Chronic Obstructive Pulmonary Disease (COPD) is a disease of premature aging, characterized by airflow limitations in the lungs and systemic chronic inflammation. This systematic review aimed to provide a systematic overview of immunosenescence and inflammation in Chronic Obstructive Pulmonary Disease (COPD). Methods: The PubMed, Science Direct, Scopus, Cochrane Library, and Web of Science databases were searched for studies on markers of immunosenescence. Observational studies comparing patients with COPD to individuals without disease were evaluated, considering the following markers: inflammation and senescence in COPD, naïve, memory, and CD28null T cells, and telomere length in leukocytes. Results: A total of 15 studies were included, eight of which were rated as high quality. IL-6 production, telomere shortening, and the higher frequencies of CD28null T cells were more prominent findings in the COPD studies analyzed. Despite lung function severity being commonly investigated in the included studies, the importance of this clinical marker to immunosenescence remains inconclusive. Conclusions: The findings of this systematic review confirmed the presence of accelerated immunosenescence, in addition to systemic inflammation, in stable COPD patients. Further studies are necessary to more comprehensively evaluate the impact of immunosenescence on lung function in COPD.

Intimate Partner Violence and Inflammaging: Conflict Tactics Predict Inflammation Among Middle-Aged and Older Adults

OBJECTIVE

In long-term relationships, conflict is inevitable, but physical and psychological aggression is not. Intimate partner violence is a known risk factor for age-related disease onset, and inflammation likely links the two. This study explores relationships between frequency of constructive (i.e., negotiation) and destructive (i.e., aggression) conflict tactics with inflammation in both younger and older adulthood. Based on the theory of inflammaging, the study investigates whether these associations were stronger in mid-to-late adulthood.

METHODS

At one visit, 214 participants in long-term romantic relationships had their blood drawn to assess six inflammatory markers (interleukin-6 [IL-6], tumor necrosis factor α [TNF-α], C-reactive protein, serum amyloid A (SAA), soluble intercellular adhesion molecule (sICAM), soluble vascular cell adhesion molecule) and reported frequency of destructive and constructive conflict tactics with their partner in the past year on the Revised Conflict Tactics Scale short form.

RESULTS

Age interacted with number of destructive conflicts per year to predict serum IL-6 ( F (1,200) = 5.3, p = .022), TNF-α ( F (1,180) = 4.2, p = .043), sICAM ( F (1,193) = 7.0, p = .008), and marginally SAA ( F (1,199) = 3.7, p = .055), such that middle-aged and older adults who reported more destructive tactics had higher inflammation. Also, the relationship between constructive conflict frequency and TNF-α also depended on age ( F (1,177) = 4.9, p = .029), in that older adults who reported a greater number of constructive tactics had lower TNF-α.

CONCLUSION

Couples' conflict tactics may influence levels of inflammation and therefore aging rate in mid-to-late life. Middle-aged and older adults may disproportionately benefit from a healthy partnership and suffer from an unhealthy partnership.

Changes in Purpose in Life and Low-Grade Chronic Inflammation Across Older Adulthood

Background: Older adults often experience an increase in low-grade chronic inflammation. Purpose in life could act as a protective factor as it is associated with beneficial health outcomes. Purpose in life may exert part of its adaptive function by promoting persistence in goal pursuit. During older adulthood, however, when many individuals experience an increase in intractable stressors and declining resources, the adaptive function of purpose could become reduced. Purpose: We examined whether the association between inter- and intra-individual differences in purpose in life and chronic inflammation differed across older adulthood. Method: We assessed four waves of data among 129 older adults (63-91 years old) across 6 years. Results: Hierarchical linear modeling demonstrated that within-person increases in purpose in life predicted reduced levels of chronic inflammation in early old age (25th percentile or 73 years, coefficient = -.016, p < .01), but not in advanced old age (75th percentile or 81 years, coefficient = .002, p = .67). Between-person differences in purpose were not related to chronic inflammation. Conclusions: These results suggest that greater within-person increases in purpose may protect health processes particularly in early old age but become less effective in advanced old age.

Reflections on resilience

Resilience research has long sought to understand how factors at the child, family, school, community, and societal levels shape adaptation in the face of adversities such as poverty and war. In this article we reflect on three themes that may prove to be useful for future resilience research. First is the idea that mental and physical health can sometimes diverge, even in response to the same social process. A better understanding of explanations for this divergence will have both theoretical and public health implications when it comes to efforts to promote resilience. Second is that more recent models of stress suggest that stress can accelerate aging. Thus, we suggest that research on resilience may need to also consider how resilience strategies may need to be developed in an accelerated fashion to be effective. Third, we suggest that if psychological resilience interventions can be conducted in conjunction with efforts to enact system-level changes targeted at adversities, this may synergize the impact that any single intervention can have, creating a more coordinated and effective set of approaches for promoting resilience in young people who confront adversity in life.

Evaluation of a Photo Captioning Cognitive Empathy Intervention for Dementia Caregivers

OBJECTIVES

The goal of this study was to develop and evaluate an intervention aimed at increasing cognitive empathy, improving mental health, and reducing inflammation in dementia caregivers, and to examine the relevant neural and psychological mechanisms.

METHODS

Twenty dementia caregivers completed an intervention that involved taking 3-5 daily photographs of their person living with dementia (PLWD) over a period of 10 days and captioning those photos with descriptive text capturing the inner voice of the PLWD. Both before and after the intervention, participants completed questionnaires, provided a blood sample for measures of inflammation, and completed a neuroimaging session to measure their neural response to viewing photographs of their PLWD and others.

RESULTS

87% of enrolled caregivers completed the intervention. Caregivers experienced pre- to post-intervention increases in cognitive empathy (i.e. Perspective-Taking) and decreases in both burden and anxiety. These changes were paralleled by an increased neural response to photographs of their PLWD within brain regions implicated in cognitive empathy.

CONCLUSION

These findings warrant a larger replication study that includes a control condition and follows participants to establish the duration of the intervention effects.

CLINICAL IMPLICATIONS

Cognitive empathy interventions may improve caregiver mental health and are worthy of further investigation.

How Loneliness Gets Under the Skin: Inflammation Mediates the Relationship Between Loneliness and Gait Speed

OBJECTIVE

Loneliness is linked to interleukin 6 (IL-6), a marker of systemic inflammation, which chronically has deleterious effects on physical and mental health across the adult life span. This study investigated cross-sectional relationships among loneliness, IL-6, demographics, multimorbidity, depression, obesity, friendship quantity, and slowed gait.

METHODS

Data from the Midlife Development in the United States Biomarker Project, a national adult sample ( N = 822; age range, 26-78 years) was used for this study. The PROCESS macro tested the hypothesis that IL-6 would mediate the relationship between loneliness and gait, after adjusting for demographic and health risk factors.

RESULTS

Age ( β = 0.292, p < .001), sex ( β = 0.197, p < .001), body mass index (BMI, β = 0.374, p < .001), waist-hip ratio ( β = 0.242, p < .001), and loneliness ( β = 0.089, p = .025) but not multimorbidity ( β = 0.043, p = .20), depression history ( β = 0.022, p = .47), depression symptoms ( β = 0.036, p = .28), and number of friends ( β = 0.022, p = .46) contributed to the variance in IL-6. Serial mediation analyses supported the chained effect of loneliness on walking time through BMI and IL-6. Results also showed specific indirect effects of BMI and IL-6 on walking time, suggesting more than one pathway by which loneliness influences health.

CONCLUSIONS

These results suggest that loneliness may increase the risk of systemic inflammation, leading to slowed gait and adverse health outcomes. Psychosocial interventions that address loneliness may provide an optimal treatment target for reducing inflammation and preventing declines in health.

A Systematic Review of Intervention Trials Utilizing Biomarkers Among Informal Caregivers of People with Alzheimer's Disease & Related Dementias

Informal caregivers of people with Alzheimer's Disease and Related Dementias (ADRD) experience unique stressors, reduced quality of life, and report poorer health, compared to non-caregivers. Throughout the last thirty years, researchers have developed and tested various psychosocial interventions and their ability to improve caregiver health. Due to an exclusive focus on self-report methods, however, no existing systematic literature reviews specifically examine intervention studies employing biomarkers; this systematic review aims to address this gap in the literature. In each database (PubMed and Web of Science, respectively), a title search was conducted with the following keywords: "alzheimer*" OR "dementia" AND "caregiv*" AND "intervention", followed by a second search using identical keywords except "intervention" was replaced with "program." Study or intervention protocol articles, exclusively qualitative studies, cultural applicability papers, dissemination studies, descriptive articles or program reports, acceptability/feasibility studies, studies utilizing formal caregiving samples, commentaries, review papers, and meta-analyses, erratums/corrections, measure development articles, factor analyses, and case reports were excluded from the final pool of studies. In this systematic review, the findings of 14 studies are summarized, and are organized based on specific types of biomarkers: neuroendocrine, immune, and autonomic physiological. Overall, the review yielded mixed results, which may, in part, be due to differences in the types of interventions tested, as well as differing biomarker measurement, methodology, and analysis. More biobehavioral intervention trials are needed among ADRD caregivers. Including biological parameters as pre- and post-measures can shed insight into the extent to which interventions may help caregivers heal from the stress of caregiving.

Diet Quality Mediates the Relationship Between Chronic Stress and Inflammation in Patients With Metabolic Syndrome

BACKGROUND

Chronic stress is associated with promotion of inflammation and development of metabolic syndrome, as well as deterioration of diet quality. Inflammation can be modified by changes in dietary intake.

OBJECTIVE

The aim of this study was to test the hypothesis that diet quality mediates the relationship of chronic stress with inflammation in patients with metabolic syndrome.

METHODS

Participants with metabolic syndrome (n = 73, 62 ± 12 years old, 71% female) completed questionnaires on chronic stress (Perceived Stress Scale-10) and diet quality (Healthy Eating Index-2020). The Perceived Stress Scale-10 was dichotomized. The Healthy Eating Index-2020 score was used as a continuous variable, and higher scores indicate better diet quality. Inflammation was assessed using plasma high-sensitivity C-reactive protein (log-transformed). We used PROCESS in SPSS to test the hypothesis.

RESULTS

Patients in the higher stress group had lower Healthy Eating Index-2020 scores (worse diet quality) than those in the lower stress group (57 ± 13 vs 64 ± 10, P = .01). Diet quality mediated the relationship between chronic stress and inflammation (indirect effect, 0.211; 95% bootstrap confidence interval, 0.006-0.496). Higher stress was associated with lower diet quality (effect, -7.152; 95% confidence interval, -13.168 to -1.137) that was associated with increased inflammation (effect, -0.030; 95% confidence interval, -0.052 to -0.007).

CONCLUSIONS

Our findings show the important role of diet quality in the relationship of chronic stress with inflammation in patients with metabolic syndrome. Healthcare providers should encourage patients with higher stress to improve diet quality, which can decrease inflammation.

Immune-neuroendocrine patterning and response to stress. A latent profile analysis in the English longitudinal study of ageing

Psychosocial stress exposure can disturb communication signals between the immune, nervous, and endocrine systems that are intended to maintain homeostasis. This dysregulation can provoke a negative feedback loop between each system that has high pathological risk. Here, we explore patterns of immune-neuroendocrine activity and the role of stress. Using data from the English Longitudinal Study of Ageing (ELSA), we first identified the latent structure of immune-neuroendocrine activity (indexed by high sensitivity C-reactive protein [CRP], fibrinogen [Fb], hair cortisol [cortisol], and insulin growth-factor-1 [IGF-1]), within a population-based cohort using latent profile analysis (LPA). Then, we determined whether life stress was associated with membership of different immune-neuroendocrine profiles. We followed 4,934 male and female participants, with a median age of 65 years, over a four-year period (2008-2012). A three-class LPA solution offered the most parsimonious fit to the underlying immune-neuroendocrine structure in the data, with 36 %, 40 %, and 24 % of the population belonging to profiles 1 (low-risk), 2 (moderate-risk), and 3 (high-risk), respectively. After adjustment for genetic predisposition, sociodemographics, lifestyle, and health, higher exposure to stress was associated with a 61 % greater risk of belonging to the high-risk profile (RRR: 1.61; 95 %CI = 1.23-2.12, p = 0.001), but not the moderate-risk profile (RRR = 1.10, 95 %CI = 0.89-1.35, p = 0.401), as compared with the low-risk profile four years later. Our findings extend existing knowledge on psychoneuroimmunological processes, by revealing how inflammation and neuroendocrine activity cluster in a representative sample of older adults, and how stress exposure was associated with immune-neuroendocrine responses over time.

N-Stearoylethanolamine Exerts Cardioprotective Effects in Old Rats

BACKGROUND

Aging is associated with the slowing down of metabolic processes, diminished physiological processes, changes in hormonal activity and increasing exposure to oxidative stress factors and chronic inflammation. The endocannabinoid system (ECS) is a major signaling network that plays a pro-homeostatic role in the central and peripheral organs of the human body. A class of minor lipids, N-acylethanolamines (NAEs), which do not activate cannabinoid receptors, except for anandamide, but can potentiate the action of endocannabinoids and have a wide spectrum of biological activity and significant adaptogenic potential, belongs to ECS. The results of different studies over the past decades have established the protective effect of NAE on many pathological conditions.

OBJECTIVE

This study aimed to investigate the cardioprotective effects of C18:0 NAE- N-stearoylethanolamine (NSE) in aged rats. In this study, we focused on investigating the effects of C18:0 NAE- N-stearoylethanolamine (NSE) on the intensity of oxidative/ nitrosative stress, antioxidant potential, lipoprotein profile and inflammation markers of blood plasma, phospholipid composition and age-related morphological changes of old rat heart tissues.

METHODS

The study was conducted on Sprague Dawley male laboratory rats. The three groups of rats were involved in the study design. The first group consisted of young rats aged 4 months (n=10). The second (n=10) and third (n=10) groups included old rats aged of 18 months. Rats from the third group were administered a per os aqueous suspension of NSE at a dose of 50 mg/kg of body weight daily for 10 days. All groups of rats were kept on a standard vivarium diet. The blood plasma, serum, and heart of rats were used for biochemical and histological analysis.

RESULTS

The cardioprotective effect of N-stearoylethanolamine in old rats was established, which was expressed in the normalization of the antioxidant system condition and the level of proinflammatory cytokines, positive modulation of blood plasma and lipoprotein profile, normalization of heart tissue lipid composition, and significant reduction in age-related myocardium morphological changes.

CONCLUSION

The revealed effects of N-stearoylethanolamine can become the basis for developing a new drug for use in complex therapy to improve the quality of life of older people.

Understanding the health effects of caregiving stress: New directions in molecular aging

Dementia caregiving has been linked to multiple health risks, including infectious illness, depression, anxiety, immune dysregulation, weakened vaccine responses, slow wound healing, hypertension, cardiovascular disease, metabolic syndrome, diabetes, frailty, cognitive decline, and reduced structural and functional integrity of the brain. The sustained overproduction of proinflammatory cytokines is a key pathway behind many of these risks. However, contrasting findings suggest that some forms of caregiving may have beneficial effects, such as maintaining caregivers' health and providing a sense of meaning and purpose which, in turn, may contribute to lower rates of functional decline and mortality. The current review synthesizes these disparate literatures, identifies methodological sources of discrepancy, and integrates caregiver research with work on aging biomarkers to propose a research agenda that traces the mechanistic pathways of caregivers' health trajectories with a focus on the unique stressors facing spousal caregivers as compared to other informal caregivers. Combined with a focus on psychosocial moderators and mechanisms, studies using state-of-the-art molecular aging biomarkers such as telomere length, p16INK4a, and epigenetic age could help to reconcile mixed literature on caregiving's sequelae by determining whether and under what conditions caregiving-related experiences contribute to faster aging, in part through inflammatory biology. The biomarkers predict morbidity and mortality, and each contributes non-redundant information about age-related molecular changes -together painting a more complete picture of biological aging. Indeed, assessing changes in these biopsychosocial mechanisms over time would help to clarify the dynamic relationships between caregiving experiences, psychological states, immune function, and aging.

Inflammatory biomarkers link perceived stress with metabolic dysregulation

Objective

Perceived stress has been identified as a risk factor for metabolic syndrome. However, the intermediate pathways underlying this relationship are not well understood. Inflammatory responses may be one process by which stress leads to metabolic dysregulation. Prior work has shown that chronic stress is associated with elevated systemic inflammation and that altered inflammatory activity contributes to the pathogenesis of metabolic syndrome. The current analyses tested this hypothesis by examining inflammation as a pathway by which perceived stress affects metabolic health.

Methods

Data from the Midlife in the United States Study (MIDUS) (N = 648; Mean age = 52.3) provided measures of perceived stress, inflammatory biomarkers [C-reactive protein (CRP), interleukin-6 (IL-6), E-selectin, fibrinogen, intracellular adhesion molecule-1 (ICAM-1)] and metabolic health markers. Confirmatory factor analysis (CFA) was used to confirm the fit of a hierarchical model of metabolic syndrome in our sample. Structural equation modeling (SEM) was used to test the assumption that inflammation mediates the association between perceived stress and the latent factor representing metabolic syndrome.

Results

The CFA of metabolic syndrome demonstrated excellent goodness of fit to our sample [CFI = 0.97, TLI = 0.95, RMSEA = 0.06, SMSR = 0.05]. Mediation analysis with SEM revealed that the indirect pathway linking stress to metabolic dysregulation through inflammation was significant [B = 0.08, SE = 0.01, z = 3.69, p < .001, 95% confidence interval CI (0.04, 0.13)].

Conclusions

These results suggest that inflammatory biomarkers are a viable explanatory pathway for the relationship between perceived stress and metabolic health consequences. Interventions that target psychosocial stress may serve as cost-effective and accessible treatment options for mitigating inflammatory health risks.

The effect and safety of probiotics on depression: a systematic review and meta-analysis of randomized controlled trials

PURPOSE

With the escalating social pressures, there has been a continuous rise in the prevalence of depression among the population, leading to substantial healthcare burdens. Moreover, conventional pharmacological interventions still exhibit certain limitations. Therefore, the primary objective of this study is to systematically evaluate the clinical efficacy of probiotics in the treatment of depression.

METHODS

Randomized controlled trials of probiotics in treating depressive symptoms were retrieved from Pubmed, Cochrane Library, Web of Science, Wan Fang database, and CNKI between the establishment of the database and March 2022. The primary outcome was Beck's depression rating scale (BDI) scores, while the secondary outcomes were depression scores on the DASS-21 scale, biochemical indicators (IL-6, NO, and TNF-α levels), and adverse events. In addition, Revman 5.3 was used for Meta-analysis and quality evaluation, and Stata 17 was used for the Egger test and Begg's test. A total of 776 patients, including 397 and 379 patients in the experimental and control groups, respectively, were included.

RESULTS

The total BDI score of the experimental group was lower than that of the control group (MD = - 1.98, 95%CI - 3.14 to - 0.82), and the score of DASS (MD = 0.90, 95%CI - 1.17 to 2.98), the IL-6 level (SMD = - 0.55, 95%CI - 0.88 to - 0.23), the NO level (MD = 5.27, 95% CI 2.51 to 8.03), and the TNF-α level (SMD = 0.19, 95% CI - 0.25 to 0.63).

CONCLUSION

The findings substantiate the therapeutic potential of probiotics in mitigating depressive symptoms by significantly reducing Beck's Depression Inventory (BDI) scores and alleviating the overall manifestation of depression.

Impact of a Stress Reduction, Meditation, and Mindfulness Program in Patients with Chronic Heart Failure: A Randomized Controlled Trial

Heart Failure is a significant public health problem leading to a high burden of physical and psychological symptoms despite optimized therapy. To evaluate primarily the impact of a Stress Reduction, Meditation, and Mindfulness Program on stress reduction of patients with Heart Failure. A randomized and controlled clinical trial assessed the effect of a stress reduction program compared to conventional multidisciplinary care in two specialized centers in Brazil. The data collection period took place between April and October 2019. Thirty-eight patients were included and allocated to the intervention or control groups. The intervention took place over 8 weeks. The protocol assessed the scales of perceived stress, depression, quality of life, anxiety, mindfulness, quality of sleep, a 6-minute walk test, and biomarkers analyzed by a blinded team, considering a p-value <0.05 statistically significant. The intervention resulted in a significant reduction in perceived stress from 22.8 ± 4.3 to 14.3 ± 3.8 points in the perceived stress scale-14 items in the intervention group vs. 23.9 ± 4.3 to 25.8 ± 5.4 in the control group (p-value<0.001). A significant improvement in quality of life (p-value=0.013), mindfulness (p-value=0.041), quality of sleep (p-value<0.001), and the 6-minute walk test (p-value=0.004) was also observed in the group under intervention in comparison with the control. The Stress Reduction, Meditation, and Mindfulness Program effectively reduced perceived stress and improved clinical outcomes in patients with chronic Heart Failure.

Intestinal Microbiomics and Metabolomics Insights into the Hepatoprotective Effects of Lactobacillus paracasei CCFM1222 Against the Acute Liver Injury in Mice

In recent years, acute liver injury (ALI) has received wide-range attention in the world due to its relatively high morbidity and mortality. This study aimed to explore the hepatoprotective effect of Lactobacillus paracasei CCFM1222 against lipopolysaccharide (LPS)-induced ALI mice and further elaborate its mechanism of action from the perspective of intestinal microbiomics and metabolomics. The results displayed that L. paracasei CCFM1222 pretreatment significantly decreased the serum ALT, and AST levels, inhibited the releases of hepatic TNF-α, IL-1β, and IL-6 levels, and activated the SOD, CAT, and GSH-Px activities in LPS-treated mice. The cecal short-chain fatty acid (SCFAs) levels were increased in LPS-treated mice with L. paracasei CCFM1222 pretreatment. In addition, L. paracasei CCFM1222 pretreatment remarkably shifted the intestinal microbiota composition, including the higher abundance of Faecalibaculum, Bifidobacterium, and lower abundance of the Prevotellaceae NK3B31 group, which is positively associated with the cecal propionic, butyric, valeric, isobutyric, and isovaleric acids. The metabolomics based on UPLC-QTOF/MS revealed that L. paracasei CCFM1222 pretreatment significantly regulated the composition of feces metabolites in LPS-treated mice, especially the potential biomarker-related butanoate metabolism, vitamin B6 metabolism, D-glutamine and D-glutamate metabolism, tryptophan metabolism, caffeine metabolism, arginine biosynthesis, arginine, and proline metabolism. Moreover, L. paracasei CCFM1222 pretreatment remarkably regulated the expression of gene-associated ALI (including Tlr4, Myd88, Nf-kβ, iNOS, Cox2, Iκ-Bα, Nrf2, and Sirt-1). In conclusion, these results suggest the possibility that L. paracasei CCFM1222 supplementation has beneficial effects on preventing the occurrence and development of ALI by inhibiting the inflammatory responses and altering intestinal microbiota composition and their metabolites.

Interleukin-6 in Hepatocellular Carcinoma: A Dualistic Point of View

Hepatocellular Carcinoma (HCC) is a pressing health concern, demanding a deep understanding of various mediators' roles in its development for therapeutic progress. Notably, interleukin-6 (IL-6) has taken center stage in investigations due to its intricate and context-dependent functions. This review delves into the dual nature of IL-6 in HCC, exploring its seemingly contradictory roles as both a promoter and an inhibitor of disease progression. We dissect the pro-tumorigenic effects of IL-6, including its impact on tumor growth, angiogenesis, and metastasis. Concurrently, we examine its anti-tumorigenic attributes, such as its role in immune response activation, cellular senescence induction, and tumor surveillance. Through a comprehensive exploration of the intricate interactions between IL-6 and the tumor microenvironment, this review highlights the need for a nuanced comprehension of IL-6 signaling in HCC. It underscores the importance of tailored therapeutic strategies that consider the dynamic stages and diverse surroundings within the tumor microenvironment. Future research directions aimed at unraveling the multifaceted mechanisms of IL-6 in HCC hold promise for developing more effective treatment strategies and improving patient outcomes.

The Role of Inflammation in the Initiation and Progression of Myeloid Neoplasms

Myeloid malignancies are devastating hematologic cancers with limited therapeutic options. Inflammation is emerging as a novel driver of myeloid malignancy, with important implications for tumor composition, immune response, therapeutic options, and patient survival. Here, we discuss the role of inflammation in normal and malignant hematopoiesis, from clonal hematopoiesis to full-blown myeloid leukemia. We discuss how inflammation shapes clonal output from hematopoietic stem cells, how inflammation alters the immune microenvironment in the bone marrow, and novel therapies aimed at targeting inflammation in myeloid disease.

SIGNIFICANCE

Inflammation is emerging as an important factor in myeloid malignancies. Understanding the role of inflammation in myeloid transformation, and the interplay between inflammation and other drivers of leukemogenesis, may yield novel avenues for therapy.

The role of inflammation in anxiety and depression in the European U-BIOPRED asthma cohorts

BACKGROUND

Growing evidence indicates high comorbid anxiety and depression in patients with asthma. However, the mechanisms underlying this comorbid condition remain unclear. The aim of this study was to investigate the role of inflammation in comorbid anxiety and depression in three asthma patient cohorts of the Unbiased Biomarkers for the Prediction of Respiratory Disease Outcomes (U-BIOPRED) project.

METHODS

U-BIOPRED was conducted by a European Union consortium of 16 academic institutions in 11 European countries. A subset dataset from subjects with valid anxiety and depression measures and a large blood biomarker dataset were analysed, including 198 non-smoking patients with severe asthma (SAn), 65 smoking patients with severe asthma (SAs), 61 non-smoking patients with mild-to-moderate asthma (MMA), and 20 healthy non-smokers (HC). The Hospital Anxiety and Depression Scale was used to measure anxiety and depression and a series of inflammatory markers were analysed by the SomaScan v3 platform (SomaLogic, Boulder, Colo). ANOVA and the Kruskal-Wallis test were used for multiple-group comparisons as appropriate.

RESULTS

There were significant group effects on anxiety and depression among the four cohort groups (p < 0.05). Anxiety and depression of SAn and SAs groups were significantly higher than that of MMA and HC groups (p < 0.05. There were significant differences in serum IL6, MCP1, CCL18, CCL17, IL8, and Eotaxin among the four groups (p < 0.05). Depression was significantly associated with IL6, MCP1, CCL18 level, and CCL17; whereas anxiety was associated with CCL17 only (p < 0.05).

CONCLUSIONS

The current study suggests that severe asthma patients are associated with higher levels of anxiety and depression, and inflammatory responses may underlie this comorbid condition.

Sex Differences in the Relationship between Perceived Stress and Cognitive Trajectories

OBJECTIVE

Chronic stress adversely affects cognition, in part due to stress-induced inflammation. Rodent models suggest females are more resilient against stress-related cognitive dysfunction than males; however, few studies have examined this in humans. We examined sex differences in the relationship between perceived stress, cognitive functioning, and peripheral inflammation over time among cognitively normal older adults.

DESIGN

Longitudinal observational study.

SETTING

University research center.

PARTICIPANTS

274 community-dwelling older adults (baseline age: M=70.7, SD=7.2; 58% women; Clinical Dementia Rating=0) who completed at least two study visits.

MEASUREMENTS

Neurocognitive functioning and perceived stress (Perceived Stress Scale [PSS]) were assessed at each visit. Plasma was analyzed for interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α) in a subset of 147 participants. Linear mixed effects models examined the interaction between average PSS (i.e., averaged within persons across visits), sex, and time on cognitive domains and on inflammatory markers.

RESULTS

The interaction between stress, sex, and time predicted executive functioning (β = 0.26, SE = 0.10, p = 0.01) such that higher average PSS related to steeper declines in men, but not in women. Among the 147 participants with inflammatory data, higher average PSS was associated with steeper increases in IL-6 over time in men, but not in women.

CONCLUSION

Consistent with animal models, results showed older men were more vulnerable to negative effects of stress on cognitive aging, with domain-specific declines in executive function. Findings also suggest systemic immunological mechanisms may underlie increased risk for cognitive decline in men with higher levels of stress. Future work is needed to examine the potential efficacy of person-specific stress interventions.

The impact of preexisting psychiatric disorders and antidepressant use on COVID-19 related outcomes: a multicenter study

Pre-existing mental disorders are linked to COVID-19-related outcomes. However, the findings are inconsistent and a thorough analysis of a broader spectrum of outcomes such as COVID-19 infection severity, morbidity, and mortality is required. We investigated whether the presence of psychiatric diagnoses and/or the use of antidepressants influenced the severity of the outcome of COVID-19. This retrospective cohort study evaluated electronic health records from the INSIGHT Clinical Research Network in 116,498 individuals who were diagnosed with COVID-19 between March 1, 2020, and February 23, 2021. We examined hospitalization, intubation/mechanical ventilation, acute kidney failure, severe sepsis, and death as COVID-19-related outcomes. After using propensity score matching to control for demographics and medical comorbidities, we used contingency tables to assess whether patients with (1) a history of psychiatric disorders were at higher risk of more severe COVID-19-related outcomes and (2) if use of antidepressants decreased the risk of more severe COVID-19 infection. Pre-existing psychiatric disorders were associated with an increased risk for hospitalization, and subsequent outcomes such as acute kidney failure and severe sepsis, including an increased risk of death in patients with schizophrenia spectrum disorders or bipolar disorders. The use of antidepressants was associated with significantly reduced risk of sepsis (p = 0.033), death (p = 0.026). Psychiatric disorder diagnosis prior to a COVID-19-related healthcare encounter increased the risk of more severe COVID-19-related outcomes as well as subsequent health complications. However, there are indications that the use of antidepressants might decrease this risk. This may have significant implications for the treatment and prognosis of patients with COVID-19.

Dynamic model assuming mutually inhibitory biomarkers of frailty suggests bistability with contrasting mobility phenotypes

Bistability is a fundamental biological phenomenon associated with "switch-like" behavior reflecting the capacity of a system to exist in either of two stable states. It plays a role in gene regulation, cell fate switch, signal transduction and cell oscillation, with relevance for cognition, hearing, vision, sleep, gait and voiding. Here we consider a potential role for bistability in the existence of specific frailty states or phenotypes as part of disablement pathways. We use mathematical modeling with two frailty biomarkers (insulin growth factor-1, IGF-1 and interleukin-6, IL-6), which mutually inhibit each other. In our model, we demonstrate that small variations around critical IGF-1 or IL-6 blood levels lead to strikingly different mobility outcomes. We employ deterministic modeling of mobility outcomes, calculating the average trends in population health. Our model predicts the bistability of clinical outcomes: the deterministically-computed likelihood of an individual remaining mobile, becoming less mobile, or dying over time either increases to almost 100% or decreases to almost zero. Contrary to statistical models that attempt to estimate the likelihood of final outcomes based on probabilities and correlations, our model predicts functional outcomes over time based on specific hypothesized molecular mechanisms. Instead of estimating probabilities based on stochastic distributions and arbitrary priors, we deterministically simulate model outcomes over a wide range of physiological parameter values within experimentally derived boundaries. Our study is "a proof of principle" as it is based on a major assumption about mutual inhibition of pathways that is oversimplified. However, by making such an assumption, interesting effects can be described qualitatively. As our understanding of molecular mechanisms involved in aging deepens, we believe that such modeling will not only lead to more accurate predictions, but also help move the field from using mostly studies of associations to mechanistically guided approaches.

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

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

Mechanisms of Maternal Diet-Induced Obesity Affecting the Offspring Brain and Development of Affective Disorders

Depression and metabolic disease are common disorders that share a bidirectional relationship and continue to increase in prevalence. Maternal diet and maternal behaviour both profoundly influence the developmental trajectory of offspring during the perinatal period. At an epidemiological level, both maternal depression and obesity during pregnancy have been shown to increase the risk of neuropsychiatric disease in the subsequent generation. Considerable progress has been made to understand the mechanisms by which maternal obesity disrupts the developing offspring gut-brain axis, priming offspring for the development of affective disorders. This review outlines such mechanisms in detail, including altered maternal care, the maternal microbiome, inflammation, breast milk composition, and maternal and placental metabolites. Subsequently, offspring may be prone to developing gut-brain interaction disorders with concomitant changes to brain energy metabolism, neurotransmission, and behaviour, alongside gut dysbiosis. The gut microbiome may act as a key modifiable, and therefore treatable, feature of the relationship between maternal obesity and the offspring brain function. Further studies examining the relationship between maternal nutrition, the maternal microbiome and metabolites, and offspring neurodevelopment are warranted to identify novel therapeutic targets.

Marital negativity's festering wounds: The emotional, immunological, and relational toll of couples' negative communication patterns

BACKGROUND

Dyadic stress theories and research suggest that couples' negative communication patterns threaten immune and emotional health, leaving partners vulnerable to illness. Spouses' relationship perceptions can also color how they see and react to marital discussions. To identify pathways linking distressed marriages to poor health, this study examined how self-reported typical communication patterns augmented discussion-based behavioral effects on spouses' blister wound healing, emotions, and discussion evaluations.

METHODS

Married couples completed two 24-hour in-person visits where they had their blood drawn to measure baseline interleukin-6 (IL-6), received suction blister wounds, reported their typical communication patterns (demand/withdraw strategies, mutual discussion avoidance, mutual constructive communication), and engaged in marital discussions. Discussions were recorded and coded for positive and negative behaviors using the Rapid Marital Interaction Coding System (RMICS). Immediately after the discussions, spouses rated their emotions and evaluated the discussion tone and outcome. Wound healing was measured for 12 days.

RESULTS

Couples who reported typically using more demand/withdraw or mutual avoidance patterns had higher baseline IL-6, slower wound healing, greater negative emotion, lower positive emotion, and poorer discussion evaluations. In contrast, couples reporting more mutual constructive patterns reported more favorable discussion evaluations. Additionally, couples' more negative and less positive patterns exacerbated behavioral effects: Spouses had wounds that healed more slowly, reported lower positive emotion, and evaluated the discussions less positively if their typical patterns and discussion-based behaviors were more negative and less positive.

CONCLUSIONS

Couples' typical communication patterns-including how often they use demand/withdraw, mutual avoidance, and mutual constructive patterns-may color spouses' reactions to marital discussions, amplifying the biological, emotional, and relational impact. These findings help explain how distressed marriages take a toll on spouses' health.

Associations Between Dysfunctional Thoughts, Leisure Activities, and IL-6 in Caregivers of Family Members With Dementia

OBJECTIVE

Dementia caregiving is associated with negative physical health consequences, including inflammation processes. The objective of this study was to analyze the associations between dysfunctional thoughts, frequency of leisure activities, and interleukin 6 (IL-6) in a sample of dementia family caregivers.

METHODS

One hundred forty dementia caregivers participated in this cross-sectional study. The relationships among caregivers' dysfunctional thoughts, leisure activities, and IL-6 were adjusted for demographic characteristics, stressors, and physical and mental health indicators in a linear regression analysis.

RESULTS

Higher levels of dysfunctional thoughts ( t = -2.02, p = .045) were significantly associated with lower frequency of leisure activities. In turn, lower frequency of leisure activities was significantly associated with higher levels of IL-6 ( t = -2.03, p = .045). Dysfunctional thoughts were no longer significantly associated with IL-6 levels when both dysfunctional thoughts and leisure activities were included in the same model ( t = 1.78, p = .076). A significant indirect effect was found for the association between higher levels of dysfunctional thoughts and higher levels of IL-6 (standardized indirect effect = 0.036, bootstrap standard error = 0.026, 95% confidence interval = 0.0001-0.1000) through its association with fewer leisure activities.

CONCLUSIONS

Our findings suggest that the direct effect of caregivers' dysfunctional thoughts on IL-6 may be mediated by the impact on caregivers' frequency of leisure activities. Results suggest that training caregivers in reducing dysfunctional thoughts to thereby increase leisure activities may be useful in reducing inflammation.

Transitions to Family Caregiving and Latent Variables of Systemic Inflammation Over Time

Circulating levels of inflammatory biomarkers may be influenced by chronic psychological stressors such as those experienced by family caregivers. However, previous studies have found mostly small and inconsistent differences between caregivers and control samples on individual measures of systemic inflammation. Latent variables of inflammation were extracted from six biomarkers collected from two blood samples over 9 years apart for 502 participants in a national cohort study. One-half of these participants transitioned into a sustained family caregiving role between the blood samples. Two latent factors, termed "up-regulation" and "inhibitory feedback," were identified, and the transition to family caregiving was associated with a lower increase over time on the inhibitory feedback factor indexed by interleukin (IL)-2 and IL-10. No caregiving effect was found on the up-regulation factor indexed primarily by IL-6 and C-reactive protein. These findings illustrate the advantages of using latent variable models to study inflammation in response to caregiving stress.

Understanding the Connection between Gut Homeostasis and Psychological Stress

Long-term exposure to adverse life events that provoke acute or chronic psychological stress (hereinafter "stress") can negatively affect physical health and even increase susceptibility to psychological illnesses, such as anxiety and depression. As a part of the hypothalamic-pituitary-adrenal axis, corticotropin-releasing factor (CRF) released from the hypothalamus is primarily responsible for the stress response. Typically, CRF disrupts the gastrointestinal system and leads to gut microbiota dysbiosis, thereby increasing risk of functional gastrointestinal diseases, such as irritable bowel syndrome. Furthermore, CRF increases oxidative damage to the colon and triggers immune responses involving mast cells, neutrophils, and monocytes. CRF even affects the differentiation of intestinal stem cells (ISCs), causing enterochromaffin cells to secrete excessive amounts of 5-hydroxytryptamine (5-HT). Therefore, stress is often accompanied by damage to the intestinal epithelial barrier function, followed by increased intestinal permeability and bacterial translocation. There are multi-network interactions between the gut microbiota and stress, and gut microbiota may relieve the effects of stress on the body. Dietary intake of probiotics can provide energy for ISCs through glycolysis, thereby alleviating the disruption to homeostasis caused by stress, and it significantly bolsters the intestinal barrier, alleviates intestinal inflammation, and maintains endocrine homeostasis. Gut microbiota also directly affect the synthesis of hormones and neurotransmitters, such as CRF, 5-HT, dopamine, and norepinephrine. Moreover, the Mediterranean diet enhances the stress resistance to some extent by regulating the intestinal flora. This article reviews recent research on how stress damages the gut and microbiota, how the gut microbiota can improve gut health by modulating injury due to stress, and how the diet relieves stress injury by interfering with intestinal microflora. This review gives insight into the potential role of the gut and its microbiota in relieving the effects of stress via the gut-brain axis.

Post-Inflammatory Hyperpigmentation in Dark Skin: Molecular Mechanism and Skincare Implications

Human skin is characterized by significant diversity in color and tone, which are determined by the quantity and distribution of melanin pigment in the epidermis. Melanin absorbs and reflects ultraviolet radiation (UVR), preventing the damage to genomic DNA in the epidermis and degradation of collagen in the dermis; therefore, darker skin types are thought to be well protected from the photodamage because of the high melanin content. However, increased content of melanin in combination with the extrinsic stress factors causing inflammation such as excess UVR, allergic reactions, or injury can also frequently lead to cosmetic problems resulting in discoloration and scarring. This review summarizes current knowledge on histopathology and likely molecular signatures of one of the most common problems, post-inflammatory hyperpigmentation (PIH). The mechanisms proposed so far are subsequently discussed in the context of other factors characterizing darker skin types. This includes the common cellular features, organization of upper skin layers, and major biomarkers, with particular emphasis on increased propensities to systemic and localized inflammation. Enhanced or prolonged inflammatory responses can not only affect the process of melanogenesis but also have been implicated in injury-related skin pathologies and aging. Finally, we summarize the major cosmetic treatments for PIH and their known anti-inflammatory targets, which can be beneficial for darker skin tones and combined with broad-spectrum filters against UVR.

Stress- and drug-induced neuroimmune signaling as a therapeutic target for comorbid anxiety and substance use disorders

Stress and substance use disorders remain two of the most highly prevalent psychiatric conditions and are often comorbid. While individually these conditions have a debilitating impact on the patient and a high cost to society, the symptomology and treatment outcomes are further exacerbated when they occur together. As such, there are few effective treatment options for these patients, and recent investigation has sought to determine the neural processes underlying the co-occurrence of these disorders to identify novel treatment targets. One such mechanism that has been linked to stress- and addiction-related conditions is neuroimmune signaling. Increases in inflammatory factors across the brain have been heavily implicated in the etiology of these disorders, and this review seeks to determine the nature of this relationship. According to the "dual-hit" hypothesis, also referred to as neuroimmune priming, prior exposure to either stress or drugs of abuse can sensitize the neuroimmune system to be hyperresponsive when exposed to these insults in the future. This review completes an examination of the literature surrounding stress-induced increases in inflammation across clinical and preclinical studies along with a summarization of the evidence regarding drug-induced alterations in inflammatory factors. These changes in neuroimmune profiles are also discussed within the context of their impact on the neural circuitry responsible for stress responsiveness and addictive behaviors. Further, this review explores the connection between neuroimmune signaling and susceptibility to these conditions and highlights the anti-inflammatory pharmacotherapies that may be used for the treatment of stress and substance use disorders.

Utilization of Nanotechnology to Improve Bone Health in Osteoporosis Exploiting Nigella sativa and Its Active Constituent Thymoquinone

Osteoporosis, a chronic bone disorder, is one of the leading causes of fracture and morbidity risk. Numerous medicinally important herbs have been evaluated for their efficacy in improving bone mass density in exhaustive preclinical and limited clinical studies. Nigella sativa L. has been used as local folk medicine, and traditional healers have used it to manage various ailments. Its reported beneficial effects include controlling bone and joint diseases. The present manuscript aimed to provide a sound discussion on the pharmacological evidence of N. sativa and its active constituent, thymoquinone, for its utility in the effective management of osteoporosis. N. sativa is reported to possess anti-IL-1 and anti-TNF-α-mediated anti-inflammatory effects, leading to positive effects on bone turnover markers, such as alkaline phosphatase and tartrate-resistant acid phosphatase. It is reported to stimulate bone regeneration by prompting osteoblast proliferation, ossification, and decreasing osteoclast cells. Thymoquinone from N. sativa has exhibited an antioxidant effect on bone tissue by reducing the FeNTA-induced oxidative stress. The present manuscript highlights phytochemistry, pharmacological effect, and the important mechanistic perspective of N. sativa and its active constituents for the management of osteoporosis. Further, it also provides sound discussion on the utilization of a nanotechnology-mediated drug delivery approach as a promising strategy to improve the therapeutic performance of N. sativa and its active constituent, thymoquinone, in the effective management of osteoporosis.

Value Ranges and Clinical Comparisons of Serum DHEA-S, IL-6, and TNF-α in Western Lowland Gorillas

Simple Summary

Biomarkers are molecules found in the body that can indicate current physiological functioning and are frequently used to monitor health and diagnose disease. These biomarkers, such as hormones and immune markers, can provide valuable information on the health and welfare of animals. Knowledge on the normal levels of these biomarkers in various species is a crucial step for monitoring health and understanding disease. In this paper, we report assays and value ranges of biomarkers rarely measured in western lowland gorillas in human care. We also compare concentrations of each biomarker between clinical and non-clinical samples. The levels of the two immune biomarkers were higher in clinical samples, but the levels of the neuroendocrine biomarker were not significantly different between clinical and non-clinical samples. These data contribute toward eventually establishing reference ranges for these biomarkers and help improve our understanding of health and welfare in zoo-housed animals.

Abstract

Physiological data can provide valuable information about the health and welfare of animals. Unfortunately, few validated assays and a lack of information on species-typical levels of circulating biomarkers for wildlife make the measurement, interpretation, and practical application of such data difficult. We validated commercially available kits and calculated reference intervals (herein called “value ranges”) for dehydroepiandrosterone-sulfate (DHEA-S), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) in a sample of zoo-housed western lowland gorillas due to the roles these biomarkers play in stress and immune responses. For each biomarker, we present species-specific value ranges for a sample of gorillas in human care (n = 57). DHEA-S did not vary significantly by sex or age, while IL-6 was higher in males and older gorillas and TNF-α was higher in females but not associated with age. We also compared non-clinical with clinical samples (n = 21) to explore whether these biomarkers reflect changes in health status. There was no significant difference between clinical and non-clinical samples for DHEA-S, but both IL-6 and TNF-α were significantly higher in gorillas showing clinical symptoms or prior to death. Additional work is needed to improve our understanding of normal versus clinical variation in these biomarkers, and we encourage continued efforts to identify and validate additional biomarkers that can be used to inform assessments of health and welfare in wildlife.

Störungsspezifische und transdiagnostische Veränderung der Inflammationsaktivität bei psychischen Störungen

Zusammenfassung. Theoretischer Hintergrund: Empirische Befunde deuten vermehrt auf eine erhöhte Entzündungsaktivität im Zusammenhang mit psychischen Störungen hin. Inwieweit sich inflammatorische Veränderungen über Störungen hinweg unterscheiden bzw. ob Inflammation ein transdiagnostisches Korrelat psychischer Störungen darstellt, ist bisher jedoch noch nicht eindeutig beantwortet. Fragestellung: Liegen spezifische inflammatorische Marker (z. B. Zytokine) über psychische Störungen hinweg verändert vor und/oder gibt es störungsspezifische Zytokinveränderungen bei Major Depression (MDD), Bipolarer Störung, Schizophrenie und Angststörungen inkl. Posttraumatischer Belastungsstörung (PTBS). Methode: Basierend auf einer Literaturrecherche werden aktuelle metaanalytische Befunde, die Studien bei Patient_innen mit MDD, Bipolarer Störung, Schizophrenie oder Angststörungen inkl. PTBS im Vergleich zu gesunden Kontrollen betrachten, zusammengetragen und vergleichend dargestellt. Ergebnisse: Aktuelle Evidenz verweist relativ konsistent auf Veränderungen des Immunsystems, wobei v. a. das Zytokin Interleukin (IL–) 6 und das C-reaktive Protein (CRP) störungsübergreifend leicht erhöht sind. Schlussfolgerungen: Perspektivisch könnten Patient_innen mit chronisch inflammatorischen Erkrankungen und psychischen Störungen von psychotherapiebegleitenden antiinflammatorischen Maßnahmen wie bspw. körperlicher Aktivität, antiinflammatorischer Ernährung und Entspannungsverfahren profitieren.

Integrating biobehavioral information to predict mood disorder suicide risk

The will to live and the ability to maintain one's well-being are crucial for survival. Yet, almost a million people die by suicide globally each year (Aleman and Denys, 2014), making premature deaths due to suicide a significant public health problem (Saxena et al., 2013). The expression of suicidal behaviors is a complex phenotype with documented biological, psychological, clinical, and sociocultural risk factors (Turecki et al., 2019). From a brain disease perspective, suicide is associated with neuroanatomical, neurophysiological, and neurochemical dysregulations of brain networks involved in integrating and contextualizing cognitive and emotional regulatory behaviors. From a symptom perspective, diagnostic measures of dysregulated mood states like major depressive symptoms are associated with over sixty percent of suicide deaths worldwide (Saxena et al., 2013). This paper reviews the neurobiological and clinical phenotypic correlates for mood dysregulations and suicidal phenotypes. We further propose machine learning approaches to integrate neurobiological measures with dysregulated mood symptoms to elucidate the role of inflammatory processes as neurobiological risk factors for suicide.

The role of C5a-C5aR1 axis in bone pathophysiology: A mini-review

Bone remodeling is a physiological, dynamic process that mainly depends on the functions of 2 cell types: osteoblasts and osteoclasts. Emerging evidence suggests that complement system is crucially involved in the regulation of functions of these cells, especially during inflammatory states. In this context, complement component 5a (C5a), a powerful pro-inflammatory anaphylatoxin that binds the receptor C5aR1, is known to regulate osteoclast formation and osteoblast inflammatory responses, and has thus been proposed as potential therapeutic target for the treatment of inflammatory bone diseases. In this review, we will analyze the role of C5a-C5aR1 axis in bone physiology and pathophysiology, describing its involvement in the pathogenesis of some of the most frequent inflammatory bone diseases such as rheumatoid arthritis, and also in osteoporosis and bone cancer and metastasis. Moreover, we will examine C5aR1-based pharmacological approaches that are available and have been tested so far for the treatment of these conditions. Given the growing interest of the scientific community on osteoimmunology, and the scarcity of data regarding the role of C5a-C5aR1 axis in bone pathophysiology, we will highlight the importance of this axis in mediating the interactions between skeletal and immune systems and its potential use as a therapeutic target.

IL-6 affects the severity of olfactory disorder: A cross-sectional survey of 148 patients who recovered from Omicron infection using the Sniffin' Sticks test in Tianjin, China

BACKGROUND

The mechanism of olfactory disorder (OD) in patients with COVID-19 is unclear. Our study aimed to elucidate the relationships between inflammatory factors and OD in a sample of Omicron-infected patients with a high rate of vaccination in China.

METHODS

The Sniffin' Sticks 12-item test (SST-12) was performed in a cross-sectional study of 148 recovered Omicron-infected patients to evaluate OD severity. We compared demographic, laboratory, and clinical data.

RESULTS

One hundred forty-eight Omicron-infected patients were enrolled. One hundred twenty-nine cases of OD were detected. Increased inflammation contributed to OD severity, especially in the adult group. OD was shown to be aggravated by an increase in IL-6 levels. The adjusted odds ratio was 2.22 (95% CI: 0.98-5.05, P=0.056) after adjustment for age, sex and vaccine characteristics.

CONCLUSIONS

These findings indicated that the prevalence of OD remains high in vaccinated Omicron-infected patients and that SST-12 might be a feasible method to screen for OD. IL-6 may play a role in the biochemical and pathological processes underlying OD.

Emerging Roles of the Nervous System in Gastrointestinal Cancer Development

Simple Summary

Nerve–cancer cross-talk has increasingly become a focus of the oncology field, particularly in gastrointestinal (GI) cancers. The indispensable roles of the nervous system in GI tumorigenesis and malignancy have been dissected by epidemiological, experimental animal and mechanistic data. Herein, we review and integrate recent discoveries linking the nervous system to GI cancer initiation and progression, and focus on the molecular mechanisms by which nerves and neural receptor pathways drive GI malignancy.

Abstract

Our understanding of the fascinating connection between nervous system and gastrointestinal (GI) tumorigenesis has expanded greatly in recent years. Recent studies revealed that neurogenesis plays an active part in GI tumor initiation and progression. Tumor-driven neurogenesis, as well as neurite outgrowth of the pre-existing peripheral nervous system (PNS), may fuel GI tumor progression via facilitating cancer cell proliferation, chemoresistance, invasion and immune escape. Neurotransmitters and neuropeptides drive the activation of various oncogenic pathways downstream of neural receptors within cancer cells, underscoring the importance of neural signaling pathways in GI tumor malignancy. In addition, neural infiltration also plays an integral role in tumor microenvironments, and contributes to an environment in favor of tumor angiogenesis, immune evasion and invasion. Blockade of tumor innervation via denervation or pharmacological agents may serve as a promising therapeutic strategy against GI tumors. In this review, we summarize recent findings linking the nervous system to GI tumor progression, set the spotlight on the molecular mechanisms by which neural signaling fuels cancer aggressiveness, and highlight the importance of targeting neural mechanisms in GI tumor therapy.

Evaluation of Common Factors of Periodontitis and Cardiovascular Disease in Patients with the Acute Coronary Syndrome

Periodontitis is a multifactorial disease causing inflammatory destruction of supporting structures of the dentition and eventually leading to its loss. This study was designed to evaluate common risk factors for periodontitis and acute coronary syndrome in the study population and demonstrate the systemic impact of periodontitis on the occurrence of acute coronary syndrome. A total of 160 patients (35 female and 125 male) were enrolled in the study. Considering the age range, the largest group of patients (118 patients) was between 55 and 65 years, which accounted for 73.8% of the total study population. There were 35 patients (21.9%) in the age group of 45 to 54 years, while the youngest age group of 35 to 44 years had as many as seven patients. Medical history and physical examination, including periodontal status, were performed. API, PD, CAL, and CPITN were evaluated. Common risk factors for periodontitis and acute coronary syndrome were assessed. The study assessed risk factors such as hypertension, diabetes, dyslipidemia, general health, smoking, height, weight, and hip circumference. In light of the above-described etiopathogenesis of atherosclerotic disease and its association with periodontal disease, it is important to emphasize preventing and treating periodontitis, especially in patients in the so-called high-risk group for cardiovascular disease. Dentists’ introduction of an appropriate prophylactic and therapeutic plan may constitute both primary and secondary prevention of cardiovascular diseases.

The rs1800795 single nucleotide polymorphism in the IL6 gene is not associated with primary open angle glaucoma in Mexican population

PURPOSE

Interleukin-6 (IL-6) is a proinflammatory cytokine with pleiotropic effects which has been related to primary open angle glaucoma (POAG) due to its particular effect of protecting the retinal ganglion cells (RGc) from the apoptosis. Different single nucleotide polymorphisms (SNP) have been associated with POAG. The aim of this study was to determine whether an association between IL-6 rs1800795 (-174 G>C) SNP and a higher risk for POAG is present in western Mexican population.

METHODS

One hundred and sixty-five unrelated Mexican mestizo patients with POAG and 108 control subjects were included. Genomic DNA was extracted from leukocytes and purified, followed by genotyping and amplification by polymerase chain reaction (PCR) with Taqman Biosystem probes. Allelic and genotypic diversity was evaluated between cases and control subjects.

RESULTS

There was no statistically significant association between allele and genotype frequencies, neither with dominant nor recessive genetic association models (p > 0.05).

CONCLUSION

Even though there is a role of IL6 in the pathophysiology of POAG, our results ruled out the association between IL-6 and the rs1800795 SNP showing not to be an index of higher risk for POAG in Mexican population.

Associations between perceived discrimination and immune cell composition in the Jackson Heart Study

African American adults suffer disproportionately from several non-communicable and infectious diseases. Among numerous contributing factors, perceived discrimination is considered a stressor for members of historically marginalized groups that contributes to health risk, although biological pathways are incompletely understood. Previous studies have reported associations between stress and both an up-regulation of non-specific (innate) inflammation and down-regulation of specific (adaptive) immunity. While associations between perceived discrimination and markers of inflammation have been explored, it is unclear if this is part of an overall shift that also includes down-regulated adaptive immunity. Relying on a large cross-section of African American adults (n = 3,319) from the Jackson Heart Study (JHS) in Jackson, Mississippi, we tested whether perceived everyday and lifetime discrimination as well as perceived burden from lifetime discrimination were associated with counts of neutrophils (innate), monocytes (innate), lymphocytes (adaptive), and the neutrophil-to-lymphocyte ratio (NLR), derived from complete white blood cell counts with differential. In addition, DNA methylation (DNAm) was measured on the EPIC array in a sub-sample (n = 1,023) of participants, allowing estimation of CD4T, CD8T and B lymphocyte proportions. Unexpectedly, high lifetime discrimination compared to low was significantly associated with lower neutrophils (b : -0.14, [95% CI: -0.24, -0.04]) and a lower NLR (b : -0.15, [95% CI: -0.25, -0.05]) after controlling for confounders. However, high perceived burden from lifetime discrimination was significantly associated with higher neutrophils (b : 0.17, [95% CI: 0.05, 0.30]) and a higher NLR (b : 0.16, [95% CI: 0.03, 0.29]). High perceived burden was also associated with lower lymphocytes among older men, which our analysis suggested might have been attributable to differences in CD4T cells. These findings highlight immune function as a potentially important pathway linking perceived discrimination to health outcomes.

Study protocol: an observational study of distress, immune function and persistent pain in HIV

INTRODUCTION

Many people with HIV report both distress and pain. The relationship between distress and pain is bidirectional, but the mechanisms by which distress exacerbates pain are unclear. The inflammatory response to challenge (inflammatory reactivity, IR) may be a partial mediator, given that neuroimmune interactions provide a substrate for IR to also influence neurological reactivity and, thus, pain-related neural signalling. This prospective, observational, case-control study will characterise the relationships between distress, IR, pain-related signalling as captured by induced secondary hyperalgesia (SH), and pain, in people with HIV who report persistent pain (PP) (cases) or no pain (controls).

METHODS AND ANALYSIS

One hundred people with suppressed HIV, reporting either PP or no pain, will be assessed two or four times over 6 months. The primary outcomes are distress (Hopkins 25-item symptom checklist), IR (multiplex assay after LPS challenge), and PP (Brief Pain Inventory), assessed at the baseline timepoint, although each will also be assessed at follow-up time points. Induced SH will be assessed in a subsample of 60 participants (baseline timepoint only). To test the hypothesis that IR partly mediates the relationship between distress and pain, mediation analysis will use the baseline data from the PP group to estimate direct and indirect contributions of distress and IR to pain. To test the hypothesis that IR is positively associated with SH, data from the subsample will be analysed with generalised mixed effects models to estimate the association between IR and group membership, with SH as the dependent variable.

ETHICS AND DISSEMINATION

Information obtained from this study will be published in peer-reviewed journals and presented at scientific meetings. The study has been approved by the Human Research Ethics Committee of the University of Cape Town (approval number: 764/2019) and the City of Cape Town (ref: 24699).

TRIAL REGISTRATION NUMBER

NCT04757987.