Reciprocal regulation of the neural and innate immune systems

Depression decreases immunity and PD-L1 inhibitor efficacy via the hypothalamic-pituitary-adrenal (HPA) axis in triple-negative breast cancer

BACKGROUND

Depression weakens antitumor immunity, yet the underlying mechanisms linking depression and tumor growth remain unclear. This study examines the influence of depression on the hypothalamic-pituitary-adrenal (HPA) axis, immunological function, and effectiveness of immunotherapy in triple-negative breast cancer (TNBC) patients.

METHODS

A mouse model of comorbid TNBC and depression was established via chronic restraint stress (CRS) and 4T1 tumor transplantation. A programmed cell death ligand 1 (PD-L1) inhibitor was used to manage mice with TNBC, and the ability of metyrapone to reverse the immune system changes induced by HPA axis activation in depression was evaluated. Mouse peripheral blood was used to measure HPA axis activity, immune cell numbers and cytokine levels.

RESULTS

Depression activates the HPA axis, leading to increased levels of glucocorticoids. Depression led to an increase in the B-cell number and a reduction in the CD4+ T-cell and CD8+ T-cell numbers, without a statistically significant difference in the regulatory T (Treg) cell number. Furthermore, depression increased the levels of the cytokines interferon-gamma (IFN-γ), interleukin (IL)-1β, IL-4, IL-6, IL-8, and tumor necrosis factor (TNF)-α while decreasing the levels of IL-2 and IL-10. Similar results were observed in the context of PD-L1 inhibitor therapy. The depressed mice presented an increased tumor burden and a poor response to the PD-L1 inhibitor. The application of metyrapone during PD-L1 inhibitor treatment resulted in partial restoration of these depression-related alterations.

CONCLUSIONS

Depression reduces the effectiveness of PD-L1 inhibitors by altering the number of immune cells and the levels of cytokines through activation of the HPA axis.

TRANSLATIONAL RELEVANCE

Depression is common in breast cancer patients and is associated with reduced antitumor immunity. There is limited knowledge regarding the specific mechanisms through which depression impairs antitumor immunity. Immunotherapy, which promotes the restoration of antitumor immunity, represents a promising treatment strategy for TNBC patients. However, the efficacy of immunotherapy can be compromised by depressive symptoms and the administration of glucocorticoids during treatment. It is still uncertain whether increasing glucocorticoid levels can reduce the efficacy of immunotherapy in patients with depression. The potential benefits of combining immunotherapy with glucocorticoid inhibitors compared with immunotherapy alone need to be evaluated for TNBC patients with concurrent depressive symptoms. Therefore, further clarification of the specific mechanisms by which depression impairs antitumor immunity is needed to inform future optimization of immunotherapy strategies.

The mediating effect of the striatum-based connectivity on the association between high-sensitivity C-reactive protein and anhedonia in adolescent depression

BACKGROUND

The potential pairwise connections among high-sensitivity C-reactive protein (hs-CRP), striatum-based circuits, and anhedonia in adolescent depression are not clear. This study aimed to explore whether hs-CRP levels in adolescents with depression influence anhedonia via alterations of striatum-based functional connectivity (FC).

METHODS

A total of 201 adolescents (92 with depressive episodes with anhedonia (anDE), 58 with DE without anhedonia (non-anDE), and 51 healthy controls (HCs)) underwent resting-state functional magnetic resonance imaging (fMRI) and completed the anhedonia subscale of the Children's Depression Inventory (CDI). hs-CRP levels were measured from peripheral blood samples in all DE patients.

RESULTS

Compared with HCs, the anDE and non-anDE groups showed increased FC between the left dorsal caudate putamen (DCP_L) and bilateral Cerebellum Crus I, and decreased FC between the left ventral rostral putamen (VRP_L) and right parahippocampal cortex (PHC) (all p < 0.05). Only the non-anDE group exhibited increased FC between the right visual cortex (VC_R) and left cerebellum VI, VC_R, and right fusiform gyrus (FG), and the left visual cortex (VC_L) and right inferior temporal gyrus (ITG) compared to HCs (all p < 0.05). Compared to the non-anDE group, the anDE group showed reduced FC between the VC_R and left cerebellum VI and between the DCP_L and right superior frontal gyrus (SFG) (all p < 0.05). Multiple regression analysis revealed that DCP_L and right SFG FC negatively predicted anhedonia severity (β = -0.288, p = 0.007). Although hs-CRP levels had no direct effect, FC between the DCP_L and right SFG fully mediated the relationship between hs-CRP and anhedonia in the anDE group (effect = 0.184, Bootstrapping 95 % CI = 0.0156, 0.436).

CONCLUSION

The findings suggest that hs-CRP influences anhedonia through a fully mediated pathway involving alterations in the frontostriatal network, contributing to a greater understanding of the neurobiological mechanisms underlying anhedonia.

Cross-sectional and longitudinal association of sleep patterns and aneurysmal vulnerability biomarkers on high-resolution magnetic resonance vessel wall imaging

BACKGROUND

Aneurysm wall enhancement (AWE) on vessel wall imaging (VWI) scans is a robust biomarker for aneurysmal vulnerability. This study aimed to explore the association of different sleep patterns with AWE and other vulnerability features.

METHODS

Patients with unruptured intracranial aneurysms were prospectively recruited. Sleep characteristics were collected through a standard questionnaire. Poor sleep quality was defined using the Pittsburgh Sleep Quality Index (PSQI)>5. Cross-sectional multistate predictive models were used to identify various sleep patterns related to aneurysmal vulnerability. In longitudinal observation, core covariates were adjusted with each sleep characteristic to verify cross-sectional results.

RESULTS

A total of 344 aneurysms were enrolled for cross-sectional analyses, while 74 cases (21.5%) that did not receive preventive treatment participated in longitudinal follow-up. In cross-sectional analysis, U-shaped relationships were evident between AWE and nocturnal sleep duration and siesta habit. Improper nocturnal sleep duration, inappropriate siesta habits, insomnia, and snoring were significantly associated with multiple VWI markers of aneurysmal vulnerability (all P<0.05). Notably, all vulnerability indicators were related to poor sleep quality. In longitudinal analysis, short nocturnal sleep duration, snoring, and poor sleep quality were independently associated with aneurysmal progression (all P<0.05).

CONCLUSIONS

Unhealthy sleep patterns were significantly associated with multiple features related to aneurysmal vulnerability. Interventional studies are needed to evaluate the role of improving sleep burden and individual sleep symptoms as potential targets for reducing the risk of aneurysm rupture.

Regulation of Stress-Induced Immunosuppression in the Context of Neuroendocrine, Cytokine, and Cellular Processes

Understanding the regulatory mechanisms of stress-induced immunosuppression and developing reliable diagnostic methods are important tasks in clinical medicine. This will allow for the development of effective strategies for the prevention and treatment of conditions associated with immune system dysfunction induced by chronic stress. The purpose of this review is to conduct a comprehensive analysis and synthesis of existing data on the regulatory mechanisms of stress-induced immunosuppression. The review is aimed at identifying key neuroendocrine, cytokine, and cellular processes underlying the suppression of the immune response under stress. This study involved a search of scientific literature covering the neuroendocrine, cellular, and molecular mechanisms of stress-induced immunosuppression regulation, as well as modern methods for its diagnosis. Major international bibliographic databases covering publications in biomedicine, psychophysiology, and immunology were selected for the search. The results of the analysis identified key mechanisms regulating stress-induced immunosuppression. The reviewed publications provided detailed descriptions of the neuroendocrine and cytokine processes underlying immune response suppression under stress. A significant portion of the data confirms that the activation of the hypothalamic-pituitary-adrenal (HPA) axis and subsequent elevation of cortisol levels exert substantial immunosuppressive effects on immune cells, particularly macrophages and lymphocytes, leading to the suppression of innate and adaptive immune responses. The data also highlight the crucial role of cortisol and catecholamines (adrenaline and noradrenaline) in initiating immunosuppressive mechanisms under chronic stress.

Chronic g-CSF increases the neutrophil-lymphocyte ratio and decreases plasma corticosterone concentrations in Peromyscus maniculatus without impacting compulsive-like stereotypy

Increasing evidence points to brain-immune mechanisms underlying conditions characterized by neurocognitive rigidity. However, causal evidence remains elusive. Thus, the present work first aimed to investigate the naturalistic associations between rigid motor stereotypy and non-specific markers of systemic inflammation, i.e., the neutrophil-lymphocyte ratio (NLR) and plasma corticosterone concentrations in deer mice. We then explored causal immune-brain interactions by bolstering the NLR, using the recombinant human granulocyte colony-stimulating factor (g-CSF), i.e., pegfilgrastim (Peg). One-hundred and twenty (120) 3-week-old deer mice (both sexes) were exposed to nine weekly injections with normal water for injection or Peg (n = 60 per group) and then assessed for stereotypical expression. Stereotypical behaviour, the NLR, and plasma corticosterone were then measured. Our findings show that 1) NLR and plasma corticosterone concentrations do not predict stereotypical expression and 2) chronic Peg exposure significantly increased the NLR and decreased the plasma corticosterone concentration in mice of both sexes, without impacting stereotypical expression. While valuable findings related to the relationship between exogenous NLR manipulation and immune system functioning were highlighted, continued investigation will be necessary to further explore whether spontaneous stereotypy in deer mice may be associated with immune-inflammatory involvement.

Immune dysregulation in bipolar disorder

BACKGROUND

Bipolar disorder is a debilitating mood disorder associated with a high risk of suicide and characterized by immune dysregulation. In this study, we used a multi-faceted approach to better distinguish the pattern of dysregulation of immune profiles in individuals with BD.

METHODS

We analyzed peripheral blood mononuclear cells (bipolar disorder N = 39, control N = 30), serum cytokines (bipolar disorder N = 86, control N = 58), whole blood RNA (bipolar disorder N = 25, control N = 25), and whole blood DNA (bipolar disorder N = 104, control N = 66) to identify immune-related differences in participants diagnosed with bipolar disorder compared to controls.

RESULTS

Flow cytometry revealed a higher proportion of monocytes in participants with bipolar disorder together with a lower proportion of T helper cells. Additionally, the levels of 18 cytokines were significantly elevated, while two were reduced in participants with bipolar disorder. Most of the cytokines altered in individuals with bipolar disorder were proinflammatory. Forty-nine genes were differentially expressed in our bipolar disorder cohort and further analyses uncovered several immune-related pathways altered in these individuals. Genetic analysis indicated variants associated with inflammatory bowel disease also influences bipolar disorder risk.

DISCUSSION

Our findings indicate a significant immune component to bipolar disorder pathophysiology and genetic overlap with inflammatory bowel disease. This comprehensive study supports existing literature, whilst also highlighting novel immune targets altered in individuals with bipolar disorder. Specifically, multiple lines of evidence indicate differences in the peripheral representation of monocytes and T cells are hallmarks of bipolar disorder.

Pathways to maternal health inequities: Structural racism, sleep, and physiological stress

Racial inequities in health are vast and well-documented, particularly regarding maternal and infant health. Sleep health, including but not limited to duration and quality, is central to overall health and well-being. However, research has not adequately addressed how racism embedded in structures and systems, in addition to individual experiences, may affect maternal health by impacting sleep. In this critical review, we aim to 1) synthesize findings, emphasizing collaborative studies within our group, 2) highlight gaps in knowledge, and 3) propose a theoretical framework and methodological approach for moving the field forward. Specifically, we focus on findings and future directions linking perinatal sleep, cardiovascular and immune function, and racial disparities in maternal health. Because too few studies look beyond individual-level determinants of sleep deficiencies among Black Americans, we assert a critical need for research that bridges multiple levels of analysis (e.g., individual, community, society) and provides recommendations for specific health parameters that researchers in this area can target. Although the need to understand and address perinatal health disparities is clear, the goal of identifying multilevel mechanisms underlying how racism in one's environment and daily life may interact to affect health extends far beyond pregnancy research.

Association between genetically predicted leisure and social activities and cardiovascular disease and other health outcomes

Participation in leisure and social activities (LSA) is associated with better health outcomes and lower mortality1-3. Previous observational studies demonstrated a relationship between engagement in LSA and both mental and physical health4,5. Although several studies6 examined the association between LSA and health outcomes, including cardiovascular disease, their possible causal relationship has not been studied. In this study, we investigated the causal relationship between LSA and various health outcomes, including cardiovascular disease, using data from genome-wide association study summary statistics (sample size = 63,926-1,557,411) and a Mendelian randomization approach. Genetically predicted LSA were associated with a reduced risk of several health outcomes, including coronary artery disease and coronary atherosclerosis. Mediation analysis indicated that these effects were partly mediated by modifiable risk factors, such as body mass index, smoking and lipid levels. These findings highlight the importance of LSA in disease prevention and health promotion.

A combined association of alanine aminotransferase, aspartate transaminase and bilirubin with sleep duration in aged 16-85 years (2005-2010)

Sleep is a vital restorative process that plays a pivotal role in maintaining the delicate equilibrium of mental and physical well-being. Both short and long sleep duration are associated with a range of adverse health outcomes. Numerous studies have consistently demonstrated a robust association between sleep duration and liver disease. In this study, we conducted statistical tests and performed subgroup analyses to explore potential variations in this association across different contexts, aiming to elucidate the correlation between ALT, AST, and TB with sleep duration. This cross-sectional investigation utilized datasets from the National Health and Nutrition Examination Survey 2005 to 2010. Multivariate linear regression models were used to examine the linear association between ALT, AST, and TB with sleep duration. Test for interaction is commonly conducted using multivariabte models to assess statistically significant subgroup disparities. Fitted smoothied curves and threshold effect analyses were employed to depict nonlinear relationships. The study enrolled 17,491 participants aged 16 to 85 years who met the inclusion and exclusion criteria, with a mean age of the participants was 45.58 ± 19.94 years. Multivariate linear regression analysis showed a significant positive association between sleep duration and ALT [-0.23 (-0.45, -0.00) 0.0455] and AST[-0.20 (-0.38, -0.01) 0.0338] in Model 3. Using a two-segment linear regression model, we found an U-shaped relationship and significant inflection point between between ALT and AST with sleep duration. The present study unveiled a significant inverse correlation between sleep duration and levels of ALT and AST, while no significant association was observed with TB levels. Furthermore, variations in the optimal sleep duration for liver function recovery were identified across diverse populations, thereby offering valuable healthcare recommendations to public.

Loneliness Gets Under the Skin: A Scoping Review Exploring the Link Between Loneliness and Biological Measures of Inflammation

BACKGROUND

Research suggests that systemic inflammation may link loneliness to adverse health outcomes, yet there is a gap in comprehensively reviewing recent evidence on the relationship between loneliness and biological measures of inflammation in adults. This scoping review synthesizes current research to address the question: Is there a definitive link between loneliness and biological markers of inflammation in adults?

METHODS

Following the methods outlined by Arksey and O'Malley, we developed a protocol, defined our research question, and systematically searched PubMed, CINAHL, Embase, and Scopus for English-language studies conducted from 2018 to 2023 exploring the relationship between loneliness and biomarkers of inflammation in adults.

RESULTS

Twelve studies meeting the inclusion criteria displayed heterogeneity in terms of sample characteristics, loneliness scales, and inflammatory biomarkers. The UCLA Loneliness Scale, in various forms, emerged as the predominant tool for measuring loneliness, while C-reactive protein and interleukin-6 were the most frequently evaluated inflammatory biomarkers. Notably, all 12 studies reported an association between loneliness and at least 1 biological marker of inflammation.

CONCLUSION

Research consistently associates loneliness with poor health outcomes in aging adults, but the underlying mechanisms remain unclear. This scoping review suggests that inflammation may serve as a pathway linking loneliness to adverse health outcomes. However, the variability across studies highlights the need for standardized measurement methods and a consideration of both the duration and extent of loneliness. Enhancing our understanding of how loneliness affects systemic inflammation may help clarify why loneliness is associated with negative health outcomes.

Sleep risk factors modify the association between c-reactive protein and type 2 diabetes: A prospective cohort study

OBJECTIVE

To investigate the prospective association between serum CRP levels and T2D incidence and explore whether such association was modified by sleep risk factors.

METHODS

The study included 366 746 participants without diabetes and exhibited CRP measures at baseline from the UK Biobank. Sleep risk factors included sleep duration, insomnia, snoring, chronotype, and daytime sleepiness. Cox proportional hazards model was used to estimate the hazard ratio (HR), and 95 % confidence interval (CI) of T2D associated with CRP levels. Interactions between CRP and sleep risk factors were also tested.

RESULTS

During a median follow-up of 10.4 years, 14 200 T2D cases were identified. The HRs (95 % CIs) of T2D were 1.31 (1.21-1.43), 1.62 (1.50-1.75), 1.98 (1.83-2.13), and 2.38 (2.21-2.57), respectively, in higher quintile groups of CRP levels compared with the lowest group (p-value for trend <0.001). There were interactions of CRP levels with self-reported sleep duration, snoring, and daytime sleepiness (p-value for interaction = 0.002, 0.0002, and 0.0001). The associated risks between T2D and the elevation in CRP were more evident among participants with high-risk sleep factors.

CONCLUSIONS

Our study indicates that the elevation in serum CRP levels is associated with a higher T2D incidence; and such relation is modified by sleep risk factors including sleep duration, snoring, and daytime sleepiness.

Transcriptomics and psychotherapy: An integrative review

Gold-standard psychotherapies like cognitive-behavioral therapy (CBT) show beneficial effects, but patient responses vary, indicating a need to predict and optimize treatment efficacy. Gene expression analysis may offer insights into the interplay between psychosocial processes and biological factors that impact psychopathology and therapeutic response. This integrative review examines 17 studies that assess gene expression in the context of psychotherapy, highlighting innovative frameworks for incorporating gene expression analysis in diagnosis, predicting treatment response, and monitoring treatment progress. Current evidence points to transcriptional control pathways downstream of the hypothalamic-pituitary-adrenal (HPA)-axis and sympathetic nervous system (SNS) signaling pathways, particularly their effects on immune cells (e.g., pro-inflammatory processes and wound healing), as key areas for future research. Higher-level pathway analyses, whether theory-based or empirically driven, appear to offer the most robust framework for future studies. This review also discusses significant limitations of current literature and proposes directions for future research.

Immunometabolism: signaling pathways, homeostasis, and therapeutic targets

Immunometabolism plays a central role in sustaining immune system functionality and preserving physiological homeostasis within the organism. During the differentiation and activation, immune cells undergo metabolic reprogramming mediated by complex signaling pathways. Immune cells maintain homeostasis and are influenced by metabolic microenvironmental cues. A series of immunometabolic enzymes modulate immune cell function by metabolizing nutrients and accumulating metabolic products. These enzymes reverse immune cells' differentiation, disrupt intracellular signaling pathways, and regulate immune responses, thereby influencing disease progression. The huge population of immune metabolic enzymes, the ubiquity, and the complexity of metabolic regulation have kept the immune metabolic mechanisms related to many diseases from being discovered, and what has been revealed so far is only the tip of the iceberg. This review comprehensively summarized the immune metabolic enzymes' role in multiple immune cells such as T cells, macrophages, natural killer cells, and dendritic cells. By classifying and dissecting the immunometabolism mechanisms and the implications in diseases, summarizing and analyzing advancements in research and clinical applications of the inhibitors targeting these enzymes, this review is intended to provide a new perspective concerning immune metabolic enzymes for understanding the immune system, and offer novel insight into future therapeutic interventions.

Behavioral coping with chronic defeat stress in mice: A systematic review of current protocols

Social stress is the most significant source of chronic stress in humans and is commonly associated with health impairment. Individual differences in the behavioral coping responses to stress have been proposed to mediate the negative effects of stress on physical, behavioral and mental health. Animal models, particularly mice, offer valuable insights into the physiological and neurobiological correlates of behavioral coping strategies in response to chronic social stress. Here we aim to identify differences and similarities among stress protocols in mice, with particular attention to how neuroendocrine and/or behavioral responses vary according to different coping strategies, while highlighting the need for standardized approaches in future research. A systematic review was undertaken following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA statement). A total of 213 references were identified by electronic search, and after the screening, 18 articles were found to meet all the established criteria. We analyzed differences in the stress protocol, the characterization and classification of coping strategies and the physiological and behavioral differences according to coping. The results show that differences in behavioural expression under chronic social stress (coping) may also be associated with physiological differences and differential susceptibility to disease. However, this review also underlines the importance of a cautious interpretation of the results obtained. The lack of consistency in the nomenclature and procedures associated with the study of coping strategies for social stress, as well as the absence of a uniform classification, highlight the importance of using a common language when approaching the study of coping strategies. Thereby, this review encourages the development of a more defined method and criteria for assessing coping strategies, based on both behavioral and biological indicators.

A female-biased gene expression signature of dominance in cooperatively breeding meerkats

Dominance is a primary determinant of social dynamics and resource access in social animals. Recent studies show that dominance is also reflected in the gene regulatory profiles of peripheral immune cells. However, the strength and direction of this relationship differs across the species and sex combinations investigated, potentially due to variation in the predictors and energetic consequences of dominance status. Here, we investigated the association between social status and gene expression in the blood of wild meerkats (Suricata suricatta; n = 113 individuals), including in response to lipopolysaccharide, Gardiquimod (an agonist of TLR7, which detects single-stranded RNA in vivo) and glucocorticoid stimulation. Meerkats are cooperatively breeding social carnivores in which breeding females physically outcompete other females to suppress reproduction, resulting in high reproductive skew. They therefore present an opportunity to disentangle the effects of social dominance from those of sex per se. We identify a sex-specific signature of dominance, including 1045 differentially expressed genes in females but none in males. Dominant females exhibit elevated activity in innate immune pathways and a larger fold-change response to LPS challenge. Based on these results and a preliminary comparison to other mammals, we speculate that the gene regulatory signature of social status in the immune system depends on the determinants and energetic costs of social dominance, such that it is most pronounced in hierarchies where physical competition is important and reproductive skew is large. Such a pattern has the potential to mediate life history trade-offs between investment in reproduction versus somatic maintenance.

Increased white blood cell in young adults with family histories of alcohol and other substance use disorders

Individuals with a family history of alcohol or other substance use disorders (FH+) are at increased risk for developing alcohol and other substance use disorders (AUD/SUD) compared to individuals with no such family histories (FH-). FH+ young adults have blunted stress reactivity, lower cognitive performance and altered frontal white matter microstructure compared to FH- controls. We hypothesized that family history of AUD/SUD disrupts neuroendocrine regulation of the immune system in FH+ individuals, resulting in altered blood immune cell composition, inflammation and neurocognitive alterations that, ultimately, increases risk for AUD/SUD and associated psychopathology. We examined white blood cell (WBC) parameters derived from complete blood counts in FH+ (n = 37) and FH- (n = 77) young adults without AUD/SUD to test if immune system dysregulation is present in FH+ individuals. The total WBC count, number of neutrophils and number of monocytes and associated systemic inflammatory response index (SIRI) were significantly increased in the FH+ group. Further, WBC, neutrophil, monocyte counts and SIRI values were all positively correlated with FH density (number of biological parents and grandparents with AUD/SUD). These novel data are the first to identify an association between family history of AUD/SUD and increased circulating leukocytes, which is likely indicative of immune dysregulation in FH+ young adults prior to onset of AUD/SUD. Additional studies are warranted to characterize the functional relevance of the observed immune cell composition in FH+ individuals, but the notion that inexpensive and widely available blood tests may help identify addiction risk could be transformative.

Neurophysiology and Molecular Basis of Cognitive Behavioral Therapy for Patients with Insomnia: Implications for Non-Pharmacological Approaches

Cognitive behavioral therapy for insomnia (CBT-I) is a widely used psychological intervention known for its effectiveness in improving insomnia symptoms. However, the neurophysiological mechanisms underlying the cognitive-behavioral treatment of insomnia remain unclear. This narrative review aimed to elucidate the neurophysiological and molecular mechanisms of CBT-I, focusing on the fields of psychology, neurophysiology, neuroendocrinology, immunology, medical microbiology, epigenetics, neuroimaging and brain function. A comprehensive search was conducted using databases including: PubMed, Embase, PsycINFO and Web of Science, with customized search strategies tailored to each database that included controlled vocabulary and alternative synonyms. It revealed that CBT-I may have a beneficial effect on the central nervous system, boost the immune system, upregulate genes involved in interferon and antibody responses, enhance functional connectivity between the hippocampus and frontoparietal areas and increase cortical gray matter thickness. In conclusion, an integrated model is proposed that elucidates the mechanisms of CBT-I and offers a new direction for investigations into its neurophysiological mechanisms.

Early life stress and iron metabolism in developmental psychoneuroimmunology

An estimated 250 million children face adverse health outcomes from early life exposure to severe or chronic social, economic, and nutritional adversity, highlighting/emphasizing the pressing concern about the link between ELS and long-term implications on mental and physical health. There is significant overlap between populations experiencing high levels of chronic stress and those experiencing iron deficiency, spotlighting the potential role of iron as a key mediator in this association. Iron, an essential micronutrient for brain development and immune function, is often depleted in stress conditions. Iron deficiency among the most common nutrient deficiencies in the world. Fetal and infant iron status may thus serve as a crucial intermediary between early chronic psychological stress and subsequent immune system changes to impact neurodevelopment. The review presents a hypothesized pathway between early life stress (ELS), iron deficiency, and neurodevelopment through the hypothalamic-pituitary-adrenocortical (HPA) axis and the IL-6-hepcidin axis. This hypothesis is derived from (1) evidence that stress impacts iron status (2) long-term neurodevelopmental outcomes that are shared by ELS and iron deficiency exposure, and (3) possible mechanisms for how iron may mediate the relation between ELS and iron deficiency through alterations in the developing immune system. The article concludes by proposing future research directions, emphasizing the need for rigorous studies to elucidate how stress and iron metabolism interact to modify the developing immune system. Understanding these mechanisms could open new avenues for improving human health and neurodevelopment for women and children globally, making it a timely and vital area of study in psychoneuroimmunology research.

Research Progress on the Effects of Different Exercise Modes on the Secretion of Exerkines After Spinal Cord Injury

Exercise training is a conventional treatment strategy throughout the entire treatment process for patients with spinal cord injury (SCI). Currently, exercise modalities for SCI patients primarily include aerobic exercise, endurance training, strength training, high-intensity interval training, and mind-body exercises. These exercises play a positive role in enhancing skeletal muscle function, inducing neuroprotection and regeneration, thereby influencing neural plasticity, reducing limb spasticity, and improving motor function and daily living abilities in SCI patients. However, the mechanism by which exercise training promotes functional recovery after SCI is still unclear, and there is no consensus on a unified and standardized exercise treatment plan. Different exercise methods may bring different benefits. After SCI, patients' physical activity levels decrease significantly due to factors such as motor dysfunction, which may be a key factor affecting changes in exerkines. The changes in exerkines of SCI patients caused by exercise training are an important and highly relevant and visual evaluation index, which may provide a new research direction for revealing the intrinsic mechanism by which exercise promotes functional recovery after SCI. Therefore, this article summarizes the changes in the expression of common exerkines (neurotrophic factors, inflammatory factors, myokines, bioactive peptides) after SCI, and intends to analyze the impact and role of different exercise methods on functional recovery after SCI from the perspective of exerkines mechanism. We hope to provide theoretical basis and data support for scientific exercise treatment programs after SCI.

IBS stress reactivity phenotype is associated with blood transcriptome profiles and microstructural and functional brain changes

Background & Aims

Clinical evidence suggests significant interindividual differences in stress reactivity (SR), but biological mechanisms and therapeutic implications of these differences are poorly understood. We aimed to identify the biological basis of increased SR by investigating associations between a psychometric-based phenotype with blood transcriptomics profiles of increased sympathetic nervous system (SNS) activation and brain imaging phenotypes in irritable bowel syndrome (IBS) participants and healthy controls (HCs).

Methods

A cross-sectional observational study design, transcriptomics profiling, multimodal brain imaging, and psychosocial assessments were obtained in 291 female and male IBS participants and HCs. Prior to analyses, unsupervised clustering was applied to derive high and low SR subgroups across participants based on two measures of SR. General linear models tested for SR group differences in clinical and biological parameters. Exploratory analyses examined associations between SR group-specific brain alterations and gene expression.

Results

The high, compared to low SR group showed greater cyclic AMP response element-binding protein (CREB) gene expression consistent with tonic SNS activity and proinflammatory changes in whole blood. Brain imaging showed neuroplastic changes in the high SR group consistent with an upregulation of ascending arousal systems and sensory processing and integration regions, and functional connectivity changes in the central autonomic network. SR moderated the sex difference in extraintestinal symptoms.

Conclusions

The findings support a model of tonically increased SNS activity as a plausible risk factor for increased autonomic reactivity to psychosocial stressors and low grade immune activation in both IBS and HCs, with a greater prevalence in IBS. These findings may have important implications for personalized treatment interventions in IBS.

Higher substance use is associated with low executive control neural activity and higher inflammation

Individuals with substance use problems show lower executive control and alterations in prefrontal brain systems supporting emotion regulation and impulse control. A separate literature suggests that heightened inflammation also increases risk for substance use, in part, through targeting brain systems involved in executive control. Research on neural and inflammatory signaling in substance use, however, has occurred in parallel. Drawing on recent neuroimmune network models, we used fMRI to examine the relationships between executive control-related brain activity (as elicited by an n-back working memory task), peripheral inflammation, as quantified by inflammatory cytokines and C-reactive protein (CRP), and substance use for the past month in 93 participants [mean age = 24.4 (SD = 0.6)]. We operationalized low executive control as a neural inefficiency during the n-back task to achieve normative performance, as reflected in higher working memory-related brain activity and lower activity in the default mode network (DMN). Consistent with prediction, individuals with low executive control and high inflammation reported more substance use over the past month, controlling for behavioral performance on the n-back, sex, time between assessments, body-mass-index (BMI), and personal socioeconomic status (SES) (interaction between inflammation and working memory-related brain activity, b = 0.210, p = 0.005; interaction between inflammation and DMN, b = -0.219, p < 0.001). Findings suggest that low executive control and high inflammation may be associated with higher substance use. This has implications for understanding psychological, neural, and immunological risk for substance use problems and the development of interventions to target each of these components.

Association of Depression With the Progression of Multimorbidity in Older Adults: A Population-Based Cohort Study

BACKGROUND

The relationship between depression and the risk of multimorbidity progression has rarely been studied in older adults. This study was aimed to determine whether depression is associated with progression in the severity and complexity of multimorbidity, considering the influence of depression's severity and subtype.

METHODS

As a part of the Korean Longitudinal Study on Cognitive Aging and Dementia, this population-based cohort study followed a random sample of community-dwelling Koreans aged 60 and older for 8 years at 2-year intervals starting in 2010. Participants included those who completed mood and multimorbidity assessments and did not exhibit complex multimorbidity at the study's outset. Depression was assessed using the Geriatric Depression Scale, while multimorbidity was evaluated using the Cumulative Illness Rating Scale. The study quantified multimorbidity complexity by counting affected body systems and measured multimorbidity severity by averaging scores across 14 body systems.

FINDINGS

The 2,486 participants (age = 69.1 ± 6.5 years, 57.6% women) were followed for 5.9 ± 2.4 years. Linear mixed models revealed that participants with depression had a faster increase in multimorbidity complexity score (β = .065, SE = 0.019, p = 0.001) than those without depression, but a comparable increase in multimorbidity severity score (β = .001, SE = .009, p = 0.870) to those without depression. Cox proportional hazard models revealed that depression was associated with the risk of developing highly complex multimorbidity affecting five or more body systems, particularly in severe or anhedonic depression.

INTERPRETATION

Depression was associated with the worsening of multimorbidity in Korean older adults, particularly when severe or anhedonic. Early screening and management of depression may help to reduce the burden of multimorbidity in older adults.

Investigations on the Ability of the Insular Cortex to Process Peripheral Immunosuppression

The brain and immune system communicate through complex bidirectional pathways, but the specificity by which the brain perceives or even remembers alterations in immune homeostasis is still poorly understood. Recent data revealed that immune-related information under peripheral inflammatory conditions, termed as "immunengram", were represented in specific neuronal ensembles in the insular cortex (IC). Chemogenetic reactivation of these neuronal ensembles was sufficient to retrieve the inflammatory stages, indicating that the brain can store and retrieve specific immune responses. Against this background, the current approach was designed to investigate the ability of the IC to process states of immunosuppression pharmacologically induced by the mechanistic target of rapamycin (mTOR) inhibitor rapamycin. We here show that the IC perceives the initial state of immunosuppression, reflected by increased deep-brain electroencephalography (EEG) activity during acute immunosuppressive drug treatment. Following an experienced period of immunosuppression, though, diminished splenic cytokine production as formerly induced by rapamycin could not be reinstated by nonspecific chemogenetic activation or inhibition of the IC. These findings suggest that the information of a past, or experienced status of pharmacologically induced immunosuppression is not represented in the IC. Together, the present work extends the view of immune-to-brain communication during the states of peripheral immunosuppression and foster the prominent role of the IC for interoception.

FLI1 in PBMCs contributes to elevated inflammation in combat-related posttraumatic stress disorder

Post-traumatic stress disorder (PTSD) is a debilitating psychiatric condition with significant public health implications that arise following exposure to traumatic events. Recent studies highlight the involvement of immune dysregulation in PTSD, characterized by elevated inflammatory markers. However, the precise mechanisms underlying this immune imbalance remain unclear. Previous research has implicated friend leukemia virus integration 1 (FLI1), an erythroblast transformation-specific (ETS) transcription factor, in inflammatory responses in sepsis and Alzheimer's disease. Elevated FLI1 levels in peripheral blood mononuclear cells (PBMCs) have been linked to lupus severity. Yet, FLI1's role in PTSD-related inflammation remains unexplored. In our study, PBMCs were collected from Veterans with and without PTSD. We found significantly increased FLI1 expression in PBMCs from PTSD-afflicted Veterans, particularly in CD4+ T cells, with no notable changes in CD8+ T cells. Stimulation with LPS led to heightened FLI1 expression and elevated levels of inflammatory cytokines IL-6 and IFNγ in PTSD PBMCs compared to controls. Knockdown of FLI1 using Gapmers in PTSD PBMCs resulted in a marked reduction in inflammatory cytokine levels, restoring them to control group levels. Additionally, co-culturing PBMCs from both control and PTSD Veterans with the human brain microglia cell line HMC3 revealed increased inflammatory mediator levels in HMC3. Remarkably, HMC3 cells co-cultured with PTSD PBMCs treated with FLI1 Gapmers exhibited significantly lower inflammatory mediator levels compared to control Gapmer-treated PTSD PBMCs. These findings suggest that suppressing FLI1 may rebalance immune activity in PBMCs and mitigate microglial activation in the brain. Such insights could provide novel therapeutic strategies for PTSD.

Patterns of Immune Dysregulation in Bipolar Disorder

Background

Bipolar disorder is a debilitating mood disorder associated with a high risk of suicide and characterized by immune dysregulation. In this study, we used a multi-faceted approach to better distinguish the pattern of dysregulation of immune profiles in individuals with BD.

Methods

We analyzed peripheral blood mononuclear cells (bipolar disorder N=39, control N=30), serum cytokines (bipolar disorder N=86, control N=58), whole blood RNA (bipolar disorder N=25, control N=25), and whole blood DNA (bipolar disorder N=104, control N=66) to identify immune-related differences in participants diagnosed with bipolar disorder compared to controls.

Results

Flow cytometry revealed a higher proportion of monocytes in participants with bipolar disorder together with a lower proportion of T helper cells. Additionally, the levels of 18 cytokines were significantly elevated, while two were reduced in participants with bipolar disorder. Most of the cytokines altered in individuals with bipolar disorder were proinflammatory. Forty-nine genes were differentially expressed in our bipolar disorder cohort and further analyses uncovered several immune-related pathways altered in these individuals. Genetic analysis indicated variants associated with inflammatory bowel disease also influences bipolar disorder risk.

Discussion

Our findings indicate a significant immune component to bipolar disorder pathophysiology and genetic overlap with inflammatory bowel disease. This comprehensive study supports existing literature, whilst also highlighting novel immune targets altered in individuals with bipolar disorder. Specifically, multiple lines of evidence indicate differences in the peripheral representation of monocytes and T cells are hallmarks of bipolar disorder.

Association between neutrophil to high-density lipoprotein cholesterol ratio (NHR) and depression symptoms among the United States adults: a cross-sectional study

BACKGROUND

Depression acts as a noteworthy worldwide public health challenge. Identifying accessible biomarkers is crucial for early diagnosis and intervention. The relationship between depression in adult Americans and the neutrophil to high-density lipoprotein cholesterol ratio (NHR) was investigated in this research.

METHODS

The relationship between NHR and depressive symptoms was analyzed utilizing National Health and Nutrition Examination Survey data from 2005 to 2018 and the Patient Health Questionnaire-9. The study included 33,871 participants with complete NHR and depression data. Adjusted multivariable logistic regression models were used to account for possible confounders, and subgroup analyses were conducted to investigate effect changes.

RESULTS

Elevated NHR levels were positively correlated with a heightened risk of depression (OR = 1.03, 95% CI: 1.01-1.05, P < 0.0005). After the NHR was divided into tertiles, those in the top tertile had an 18% higher chance of developing depression than those in the bottom tertile (OR = 1.18; 95% CI: 1.05-1.32; P for trend = 0.0041). Subgroup analyses revealed variations in this association based on race and marital status. Additionally, the relationship between NHR and depression demonstrated a U-shaped pattern, with a significant breakpoint identified at an NHR of 6.97.

CONCLUSION

These results imply that the NHR may be a potential biomarker for depression risk, with implications for early detection and personalized treatment. Further research is needed to elucidate the mechanisms underlying the NHR-depression link and establish causality.

Early Life Adversity, Microbiome, and Inflammatory Responses

Early life adversity has a profound impact on physical and mental health. Because the central nervous and immune systems are not fully mature at birth and continue to mature during the postnatal period, a bidirectional interaction between the central nervous system and the immune system has been hypothesized, with traumatic stressors during childhood being pivotal in priming individuals for later adult psychopathology. Similarly, the microbiome, which regulates both neurodevelopment and immune function, also matures during childhood, rendering this interaction between the brain and the immune system even more complex. In this review, we provide evidence for the role of the immune response and the microbiome in the deleterious effects of early life adversity, both in humans and rodent models.

Cyclooxygenase-2 inhibitors alleviated depressive and anxious-like behaviors in mice exposed to lipopolysaccharide: Involvement of oxidative stress and neuroinflammation

Depression and anxiety disorders have their pathophysiologies linked to inflammation and oxidative stress. In this context, celecoxib (CLX) and etoricoxib (ETR) inhibit cyclooxygenase 2 (COX-2), an enzyme expressed by cells involved in the inflammatory process and found in the brain. Studies have been using CLX as a possible drug in the treatment of depression, although its mechanisms at the central nervous system level are not fully elucidated. In this study, the effects of CLX and ETR on behavioral, oxidative, and inflammatory changes induced by systemic exposure to Escherichia coli lipopolysaccharide (LPS) were evaluated in adult male swiss mice. For ten days, the animals received intraperitoneal injections of LPS at 0.5 mg/kg. From the sixth to the tenth day, one hour after LPS exposure, they were treated orally with CLX (15 mg/kg), ETR (10 mg/kg), or fluoxetine (FLU) (20 mg/kg). Twenty-four hours after the last oral administration, the animals underwent evaluation of locomotor activity (open field test), predictive tests for depressive-like behavior (forced swim and tail suspension tests), and anxiolytic-like effect (elevated plus maze and hole board tests). Subsequently, the hippocampus, prefrontal cortex and striatum were dissected for the measurement of oxidative and nitrosative parameters (malondialdehyde, nitrite, and glutathione) and quantification of pro-inflammatory cytokines (IL-1β and IL-6). LPS induced depressive and anxious-like behavior, and treatment with CLX or ETR was able to reverse most of the behavioral changes. It was evidenced that nitrosative stress and the degree of lipid peroxidation induced by LPS were reduced in different brain areas after treatment with the drugs, as well as the endogenous defense system against free radicals was strengthened. CLX and ETR also significantly reduced LPS-induced cytokine levels. These data are expected to expand information on the role of inflammation in depression and anxiety and provide insights into possible mechanisms of COX-2 inhibitors in psychiatric disorders with a neurobiological basis in inflammation and oxidative stress.

A single-arm, open-label pilot study of neuroimaging, behavioral, and peripheral inflammatory correlates of mindfulness-based stress reduction in multiple sclerosis

Multiple sclerosis (MS) is a chronic neurological disease frequently associated with significant fatigue, anxiety, depression, and stress. These symptoms are difficult to treat, and prominently contribute to the decreases in quality of life observed with MS. The underlying mechanisms of these "silent" symptoms are not well understood and include not just the psychological responses to a chronic disease, but also biological contributions from bidirectional psycho-neuro-immune (dys)regulation of systemic inflammatory biology. To address these issues, we conducted a prospective, observational pilot study to investigate the psychological, biological, and neuroarchitecture changes associated with a mindfulness-based stress reduction (MBSR) program in MS. The overarching hypothesis was that MBSR modulates systemic and central nervous system inflammation via top-down neurocognitive control over forebrain limbic areas responsible for the neurobiological stress response. 23 patients were enrolled in MBSR and assessed pre/post-program with structural 3 T MRI, behavioral measures, hair cortisol, and blood measures of peripheral inflammation, as indexed by the Conserved Transcriptional Response to Adversity (CTRA) profile. MBSR was associated with improvements across a variety of behavioral outcomes, as well as on-study enlargement of the head of the right hippocampus. The CTRA analyses revealed that greater inflammatory gene expression was related to worse patient-reported anxiety, depression, stress, and loneliness, in addition to lower eudaimonic well-being. Hair cortisol did not significantly change from pre- to post-MBSR. These results support the use of MBSR in MS and elucidate inflammatory mechanisms related to key patient-reported outcomes in this population.

SIR+ models: accounting for interaction-dependent disease susceptibility in the planning of public health interventions

Avoiding physical contact is regarded as one of the safest and most advisable strategies to follow to reduce pathogen spread. The flip side of this approach is that a lack of social interactions may negatively affect other dimensions of health, like induction of immunosuppressive anxiety and depression or preventing interactions of importance with a diversity of microbes, which may be necessary to train our immune system or to maintain its normal levels of activity. These may in turn negatively affect a population's susceptibility to infection and the incidence of severe disease. We suggest that future pandemic modelling may benefit from relying on 'SIR+ models': epidemiological models extended to account for the benefits of social interactions that affect immune resilience. We develop an SIR+ model and discuss which specific interventions may be more effective in balancing the trade-off between minimizing pathogen spread and maximizing other interaction-dependent health benefits. Our SIR+ model reflects the idea that health is not just the mere absence of disease, but rather a state of physical, mental and social well-being that can also be dependent on the same social connections that allow pathogen spread, and the modelling of public health interventions for future pandemics should account for this multidimensionality.

Chronic defeat stress induces monoamine level dysregulation in the prefrontal cortex but not in the hippocampus of OF1 male mice

Chronic social stress can increase susceptibility to chronic diseases such as depression. One of the most used models to study the physiological mechanisms and behavioral outcomes of this type of stress is chronic defeat stress (CDS) in male mice. OF1 male mice were subjected to a stress period lasting 18 days. During that time, non-stressed animals were housed in groups. The cluster analysis of the behavioral profile displayed during the first social interaction divided subjects into two groups: active/aggressive (AA) and passive/reactive (PR). The day after the end of the stress period, the following behavioral analyses were performed: the sucrose preference test (SPT) on day 19, the open field test (OFT) on day 20, and the forced swim test (FST) on day 21. Immediately after completing the last test, animals were weighed, and blood samples were obtained. Then, they were sacrificed, and their prefrontal cortices and hippocampi were removed and stored to analyze monoamine levels. Stressed animals displayed anhedonia, and solely the PR mice continued to show higher levels of immobility in the OFT and FST. All stressed animals, regardless of the coping strategy, presented higher plasma corticosterone levels. In addition, stressed mice showed lower levels of tyrosine, dopamine, DOPAC, MHPG, kynurenine, kynurenic acid, and 5-HIAA levels but higher serotonin levels in the prefrontal cortex, not in the hippocampus. In conclusion, our results show that CSD induces differences in monoamine levels between brain areas, and these differences did not respond to the coping strategy adopted.

Systemic Tumors Can Cause Molecular Changes in the Hippocampus That May Have an Impact on Behavior after Chronic Social Stress

Evidence indicates that chronic social stress plays a significant role in the development of cancer and depression. Although their association is recognized, the precise physiological mechanism remains unknown. In our previous work, we observed that OF1 males subjected to chronic social defiance exhibited anhedonia, and those who developed tumors in the lung showed anxiety-associated behaviors. In this study, we observed that tumor-bearing OF1 mice presented higher levels of 3-HK, and this increase may be due to IDO. No differences in hippocampal catecholamine levels were observed. Our results suggest that a systemic tumor can induce molecular changes in the hippocampal kynurenine pathway that may impact behavior.

Health equity engineering: Optimizing hope for a new generation of healthcare

Medical researchers are increasingly prioritizing the inclusion of underserved communities in clinical studies. However, mere inclusion is not enough. People from underserved communities frequently experience chronic stress that may lead to accelerated biological aging and early morbidity and mortality. It is our hope and intent that the medical community come together to engineer improved health outcomes for vulnerable populations. Here, we introduce Health Equity Engineering (HEE), a comprehensive scientific framework to guide research on the development of tools to identify individuals at risk of poor health outcomes due to chronic stress, the integration of these tools within existing healthcare system infrastructures, and a robust assessment of their effectiveness and sustainability. HEE is anchored in the premise that strategic intervention at the individual level, tailored to the needs of the most at-risk people, can pave the way for achieving equitable health standards at a broader population level. HEE provides a scientific framework guiding health equity research to equip the medical community with a robust set of tools to enhance health equity for current and future generations.

Association of body mass index with rapid eye movement sleep behavior disorder in Parkinson's disease

Background

The association between body mass index (BMI) and rapid eye-movement (REM) sleep-related behavioral disorder (RBD) in Parkinson's disease (PD) remains unknown. Our study was to investigate the association of BMI with RBD in PD patients.

Methods

In this cross-sectional study, a total of 1,115 PD participants were enrolled from Parkinson's Progression Markers Initiative (PPMI) database. BMI was calculated as weight divided by height squared. RBD was defined as the RBD questionnaire (RBDSQ) score with the cutoff of 5 or more assessed. Univariable and multivariable logistic regression models were performed to examine the associations between BMI and the prevalence of RBD. Non-linear correlations were explored with use of restricted cubic spline (RCS) analysis. And the inflection point was determined by the two-line piecewise linear models.

Results

We identified 426 (38.2%) RBD. The proportion of underweight, normal, overweight and obese was 2.61, 36.59, 40.36, and 20.44%, respectively. In the multivariate logistic regression model with full adjustment for confounding variables, obese individuals had an odds ratio of 1.77 (95% confidence interval: 1.21 to 2.59) with RBD compared with those of normal weight. In the RCS models with three knots, BMI showed a non-linear association with RBD. The turning points of BMI estimated from piecewise linear models were of 28.16 kg/m2, 28.10 kg/m2, and 28.23 kg/m2 derived from univariable and multivariable adjusted logistic regression models. The effect modification by depression on the association between BMI and RBD in PD was also found in this study. Furthermore, the sensitivity analyses linked with cognition, education, and ethnic groups indicated the robustness of our results.

Conclusion

The current study found a significant dose-response association between BMI and RBD with a depression-based difference in the impact of BMI on RBD in PD patients.

An association study of m6A methylation with major depressive disorder

OBJECTIVE

To find the relationship between N6-methyladenosine (m6A) genes and Major Depressive Disorder (MDD).

METHODS

Differential expression of m6A associated genes between normal and MDD samples was initially identified. Subsequent analysis was conducted on the functions of these genes and the pathways they may affect. A diagnostic model was constructed using the expression matrix of these differential genes, and visualized using a nomogram. Simultaneously, an unsupervised classification method was employed to classify all patients based on the expression of these m6A associated genes. Following this, common differential genes among different clusters were computed. By analyzing the functions of the common differential expressed genes among clusters, the role of m6A-related genes in the pathogenesis of MDD patients was elucidated.

RESULTS

Differential expression was observed in ELAVL1 and YTHDC2 between the MDD group and the control group. ELAVL1 was associated with comorbid anxiety in MDD patients. A linear regression model based on these two genes could accurately predict whether patients in the GSE98793 dataset had MDD and could provide a net benefit for clinical decision-making. Based on the expression matrix of ELAVL1 and YTHDC2, MDD patients were classified into three clusters. Among these clusters, there were 937 common differential genes. Enrichment analysis was also performed on these genes. The ssGSEA method was applied to predict the content of 23 immune cells in the GSE98793 dataset samples. The relationship between these immune cells and ELAVL1, YTHDC2, and different clusters was analyzed.

CONCLUSION

Among all the m6A genes, ELAVL1 and YTHDC2 are closely associated with MDD, ELAVL1 is related to comorbid anxiety in MDD. ELAVL1 and YTHDC2 have opposite associations with immune cells in MDD.

Role of Gut Microbe Composition in Psychosocial Symptom Response to Exercise Training in Breast Cancer Survivors (ROME) study: protocol for a randomised controlled trial

INTRODUCTION

Breast cancer survivors have an increased risk for chronic fatigue and altered gut microbiota composition, both with negative health and quality of life affects. Exercise modestly improves fatigue and is linked to gut microbial diversity and production of beneficial metabolites. Studies suggest that gut microbiota composition is a potential mechanism underlying fatigue response to exercise. Randomised controlled trials testing the effects of exercise on the gut microbiome are limited and there is a scarcity of findings specific to breast cancer survivors. The objective of this study is to determine if fitness-related modifications to gut microbiota occur and, if so, mediate the effects of aerobic exercise on fatigue response.

METHODS AND ANALYSIS

The research is a randomised controlled trial among breast cancer survivors aged 18-74 with fatigue. The primary aim is to determine the effects of aerobic exercise training compared with an attention control on gut microbiota composition. The secondary study aims are to test if exercise training (1) affects the gut microbiota composition directly and/or indirectly through inflammation (serum cytokines), autonomic nervous system (heart rate variability) or hypothalamic-pituitary-adrenal axis mediators (hair cortisol assays), and (2) effects on fatigue are direct and/or indirect through changes in the gut microbiota composition. All participants receive a standardised controlled diet. Assessments occur at baseline, 5 weeks, 10 weeks and 15 weeks (5 weeks post intervention completion). Faecal samples collect the gut microbiome and 16S gene sequencing will identify the microbiome. Fatigue is measured by a 13-item multidimensional fatigue scale.

ETHICS AND DISSEMINATION

The University of Alabama at Birmingham Institutional Review Board (IRB) approved this study on 15 May 2019, UAB IRB#30000320. A Data and Safety Monitoring Board convenes annually or more often if indicated. Findings will be disseminated in peer-reviewed journals and conference presentations.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov, NCT04088708.

Genetic evidence for the causal effects of C-reactive protein on self-reported habitual sleep duration

Inflammatory responses to acute stimuli are proposed to regulate sleep, but the relationship between chronic inflammation and habitual sleep duration is elusive. Here, we study this relation using genetically predicted level of chronic inflammation, indexed by CRP and IL6 signaling, and self-reported sleep duration. By Mendelian randomization analysis, we show that elevated CRP level within <10 mg/L has a homeostatic effect that facilitates maintaining 7-8 h sleep duration per day - making short-sleepers sleep longer (p = 2.42 × 10-2) and long-sleepers sleep shorter (1.87 × 10-7); but it is not associated with the overall sleep duration (p = 0.17). This homeostatic effect replicated in an independent CRP dataset. We observed causal effects of the soluble interleukin 6 receptor and gp130 on overall sleep duration (p = 1.62 × 10-8, p = 2.61 × 10-58, respectively), but these effects disappeared when CRP effects were accounted for in the model. Using polygenic score analysis, we found that the homeostatic effect of CRP on sleep duration stems primarily from the genetic variants within the CRP gene region: when genetic variants outside of this region were used to predict CRP levels, the opposite direction of effect was observed. In conclusion, we show that elevated CRP level may causally facilitate maintaining an optimal sleep duration that is beneficial to health, thus updating our current knowledge of immune regulation on sleep.

Type I interferons, inflammation, and fatigue in a longitudinal RNA study of women with breast cancer

BACKGROUND

Fatigue is a common side effect of cancer and its treatment and is thought to be driven in part by activation of the proinflammatory cytokine network. However, the cellular and molecular underpinnings of cancer-related fatigue (CRF) have not been determined, nor have immune pathways beyond inflammation been carefully investigated. The goal of this study was to examine the association between CRF and activation of canonical proinflammatory gene regulation pathways and Type I interferon (IFN) signaling pathways in breast cancer patients during and after treatment.

METHODS

Women diagnosed with early-stage breast cancer (n = 181) completed assessments before and after treatment with radiation and/or chemotherapy and at 6, 12, and 18-month post-treatment follow-ups. Assessments included self-reported fatigue (Multidimensional Fatigue Symptom Inventory - Short Form) and expression of pre-specified sets of Type I IFN and pro-inflammatory immune response genes determined from mRNA sequencing of PBMCs. Mixed effect linear models examined changes in fatigue and immune gene expression over time and tested the hypothesis that fatigue would be associated with increased expression of Type I IFN and inflammatory response genes.

RESULTS

There were significant changes in fatigue and immune gene expression across the assessment period; all measures increased from pre- to post-treatment but showed diverging patterns over the follow-up, with declines in fatigue and persistent elevations in Type I IFN and proinflammatory gene expression. In mixed effect linear models, expression of Type I IFN response genes was elevated in association with fatigue across the assessment period, from pre-treatment to 18-month follow-up. In contrast, pro-inflammatory gene expression was associated with fatigue only at 6, 12, and 18-month follow-ups. Analyses controlling for changes in leukocyte subsets continued to show a significant association between fatigue and Type I IFN gene expression but reduced the time-dependent association with pro-inflammatory gene expression to non-significant.

CONCLUSIONS

Results revealed unexpected complexity in the immune underpinnings of CRF and identify a novel role for IFN signaling as a robust contributor to this symptom before, during, and after treatment. Pro-inflammatory gene expression emerged as a predictor of fatigue later in the cancer trajectory, and that effect was primarily accounted for by a concurrent increase in monocyte prevalence.

Twenty-Four week Taichi training improves pulmonary diffusion capacity and glycemic control in patients with Type 2 diabetes mellitus

This study evaluated the effect of 24-week Taichi training and Taichi plus resistance band training on pulmonary diffusion capacity and glycemic control in patients with Type 2 diabetes mellitus (T2DM). Forty-eight patients with T2DM were randomly divided into three groups: Group A-Taichi training: practiced Taichi 60 min/day, 6 days/week for 24 weeks; Group B-Taichi plus resistance band training: practiced 60-min Taichi 4 days/week plus 60-min resistance band training 2 days/week for 24 weeks; and Group C-controls: maintaining their daily lifestyles. Stepwise multiple regression analysis was applied to predict diffusion capacity of the lungs for carbon monoxide (DLCO) by fasting blood glucose, insulin, glycosylated hemoglobin (HbA1c), tumour necrosis factor alpha (TNF-α), von Willebrand Factor (vWF), interleukin-6 (IL-6), intercellular adhesion molecule 1 (ICAM-1), endothelial nitric oxide synthase (eNOS), nitric oxide (NO), endothelin-1 (ET-1), vascular endothelial growth factor, and prostaglandin I-2. Taichi with or without resistance band training significantly improved DLCO, increased insulin sensitivity, eNOS and NO, and reduced fasting blood glucose, insulin, HbA1c, TNF-α, vWF, IL-6, ICAM-1, and ET-1. There was no change in any of these variables in the control group. DLCO was significantly predicted (R2 = 0.82) by insulin sensitivity (standard-β = 0.415, P<0.001), eNOS (standard-β = 0.128, P = 0.017), TNF-α (standard-β = -0.259, P = 0.001), vWF (standard-β = -0.201, P = 0.007), and IL-6 (standard-β = -0.175, P = 0.032) in patients with T2DM. The impact of insulin sensitivity was the most important predictor for the variation of DLCO based on the multiple regression modeling. This study demonstrates that 24-week Taichi training and Taichi plus resistance band training effectively improve pulmonary diffusion capacity and blood glycemic control in patients with T2DM. Variation of DLCO is explained by improved insulin sensitivity and endothelial function, and reduced inflammatory markers, including TNF-α, vWF, and IL-6.

Annual Research Review: Neuroimmune network model of depression: a developmental perspective

Depression is a serious public health problem, and adolescence is an 'age of risk' for the onset of Major Depressive Disorder. Recently, we and others have proposed neuroimmune network models that highlight bidirectional communication between the brain and the immune system in both mental and physical health, including depression. These models draw on research indicating that the cellular actors (particularly monocytes) and signaling molecules (particularly cytokines) that orchestrate inflammation in the periphery can directly modulate the structure and function of the brain. In the brain, inflammatory activity heightens sensitivity to threats in the cortico-amygdala circuit, lowers sensitivity to rewards in the cortico-striatal circuit, and alters executive control and emotion regulation in the prefrontal cortex. When dysregulated, and particularly under conditions of chronic stress, inflammation can generate feelings of dysphoria, distress, and anhedonia. This is proposed to initiate unhealthy, self-medicating behaviors (e.g. substance use, poor diet) to manage the dysphoria, which further heighten inflammation. Over time, dysregulation in these brain circuits and the inflammatory response may compound each other to form a positive feedback loop, whereby dysregulation in one organ system exacerbates the other. We and others suggest that this neuroimmune dysregulation is a dynamic joint vulnerability for depression, particularly during adolescence. We have three goals for the present paper. First, we extend neuroimmune network models of mental and physical health to generate a developmental framework of risk for the onset of depression during adolescence. Second, we examine how a neuroimmune network perspective can help explain the high rates of comorbidity between depression and other psychiatric disorders across development, and multimorbidity between depression and stress-related medical illnesses. Finally, we consider how identifying neuroimmune pathways to depression can facilitate a 'next generation' of behavioral and biological interventions that target neuroimmune signaling to treat, and ideally prevent, depression in youth and adolescents.

The cancer-immune dialogue in the context of stress

Although there is little direct evidence supporting that stress affects cancer incidence, it does influence the evolution, dissemination and therapeutic outcomes of neoplasia, as shown in human epidemiological analyses and mouse models. The experience of and response to physiological and psychological stressors can trigger neurological and endocrine alterations, which subsequently influence malignant (stem) cells, stromal cells and immune cells in the tumour microenvironment, as well as systemic factors in the tumour macroenvironment. Importantly, stress-induced neuroendocrine changes that can regulate immune responses have been gradually uncovered. Numerous stress-associated immunomodulatory molecules (SAIMs) can reshape natural or therapy-induced antitumour responses by engaging their corresponding receptors on immune cells. Moreover, stress can cause systemic or local metabolic reprogramming and change the composition of the gastrointestinal microbiota which can indirectly modulate antitumour immunity. Here, we explore the complex circuitries that link stress to perturbations in the cancer-immune dialogue and their implications for therapeutic approaches to cancer.

Do dyadic interventions impact biomarkers of child health? A state-of-the-science narrative review

BACKGROUND

Early life adversity is related to numerous poor health outcomes in childhood; however, dyadic interventions that promote sensitive and responsive caregiving may protect children from the negative consequences of such exposures. To date, quasi-experimental and randomized controlled trials (RCTs) have examined the impact of dyadic interventions on a range of individual biomarkers in children, which may elucidate the relation between early stress exposure and transdiagnostic risk factors for prospective poor health. However, the content of interventions, analytic strategies, and findings vary widely across studies, obscuring key themes in the science and hindering policy and research efforts.

METHODS

We use a narrative approach to review findings from methodologically rigorous (predominantly RCT) studies of dyadic interventions' impacts on different biomarkers in children, including indicators of the hypothalamic-pituitary-adrenal (HPA) axis, parasympathetic (PNS) and sympathetic nervous systems (SNS), brain development, inflammation, and intracellular DNA processes. We contribute to this important area of inquiry through integrating findings across biological systems and identifying contextual and mechanistic factors to depict the current state of the field.

RESULTS

Evidence suggests dyadic interventions improved PNS functioning and advanced brain maturation. Some studies indicated interventions reduced hair cortisol concentrations, systemic inflammation, and resulted in differences in DNA methylation patterns. Findings did not support main effect-level change in salivary measures of HPA axis activity, SNS activity, or telomere length. Importantly, reviewed studies indicated significant heterogeneity in effects across biological systems, underscoring the importance of contextual factors (e.g., adversity subtype and severity) as potential moderators of effects. Further, findings suggested enhanced parenting behaviors may be a mechanism through which dyadic interventions operate on biomarkers.

CONCLUSIONS

We close with future policy and research directions, emphasizing the promise of biologically-informed dyadic interventions for understanding and ameliorating the effects of early adversity on transdiagnostic biomarkers of health.

Association between hs-CRP and depressive symptoms: a cross-sectional study

Background and aim

High-sensitivity C-reactive protein (hs-CRP) is a sensitive measure of low-grade inflammation and appears superior to conventional blood tests in assessing cardiovascular disease. The purpose of this investigation was to explore the link between high-sensitivity CRP and depressive symptoms among adults.

Methods and results

Multiple logistic regression and smoothed curve fitting were used to investigate the association between hs-CRP and depressive symptoms based on data from the, 2017-2020 National Health and Nutrition Examination Survey (NHANES). Subgroup analyses and interaction tests were used to assess the stability of this relationship across populations. The study comprised 6,293 non-clinical participants, which included 549 individuals with depressive symptoms. The prevalence of depressive symptoms was found to increase with increasing levels of hs-CRP. This trend persisted even after quartetting hs-CRP levels. In the fully adjusted model, each unit increase in hs-CRP was associated with a 10% increase in the odds of depressive symptoms (OR=1.10,95%CI:1.01-1.21). Participants in the highest quartile of hs-CRP had a 39% higher prevalence of depressive symptoms compared to those in the lowest quartile (OR=1.39,95%CI:1.01-1.92). Additionally, this positive correlation was more pronounced in men.

Conclusions

In adult Americans, there exists a positive association between elevated hs-CRP levels and depressive symptoms, with a more prominent manifestation of this association observed in males.

Effects of inflammation, childhood adversity, and psychiatric symptoms on brain morphometrical phenotypes in bipolar II depression

BACKGROUND

The neuroanatomical alteration in bipolar II depression (BDII-D) and its associations with inflammation, childhood adversity, and psychiatric symptoms are currently unclear. We hypothesize that neuroanatomical deficits will be related to higher inflammation, greater childhood adversity, and worse psychiatric symptoms in BDII-D.

METHODS

Voxel- and surface-based morphometry was performed using the CAT toolbox in 150 BDII-D patients and 155 healthy controls (HCs). Partial Pearson correlations followed by multiple comparison correction was used to indicate significant relationships between neuroanatomy and inflammation, childhood adversity, and psychiatric symptoms.

RESULTS

Compared with HCs, the BDII-D group demonstrated significantly smaller gray matter volumes (GMVs) in frontostriatal and fronto-cerebellar area, insula, rectus, and temporal gyrus, while significantly thinner cortices were found in frontal and temporal areas. In BDII-D, smaller GMV in the right middle frontal gyrus (MFG) was correlated with greater sexual abuse (r = -0.348, q < 0.001) while larger GMV in the right orbital MFG was correlated with greater physical neglect (r = 0.254, q = 0.03). Higher WBC count (r = -0.227, q = 0.015) and IL-6 levels (r = -0.266, q = 0.015) was associated with smaller GMVs in fronto-cerebellar area in BDII-D. Greater positive symptoms was correlated with larger GMVs of the left middle temporal pole (r = 0.245, q = 0.03).

CONCLUSIONS

Neuroanatomical alterations in frontostriatal and fronto-cerebellar area, insula, rectus, temporal gyrus volumes, and frontal-temporal thickness may reflect a core pathophysiological mechanism of BDII-D, which are related to inflammation, trauma, and psychiatric symptoms in BDII-D.

Metabolic underpinnings of cancer-related fatigue

Cancer-related fatigue (CRF) is one of the most prevalent and detrimental complications of cancer. Emerging evidence suggests that obesity and insulin resistance are associated with CRF occurrence and severity in cancer patients and survivors. In this narrative review, we analyzed recent studies including both preclinical and clinical research on the relationship between obesity and/or insulin resistance and CRF. We also describe potential mechanisms for these relationships, though with the caveat that because the mechanisms underlying CRF are incompletely understood, the mechanisms mediating the association between obesity/insulin resistance and CRF are similarly incompletely delineated. The data suggest that, in addition to their effects to worsen CRF by directly promoting tumor growth and metastasis, obesity and insulin resistance may also contribute to CRF by inducing chronic inflammation, neuroendocrinological disturbance, and metabolic alterations. Furthermore, studies suggest that patients with obesity and insulin resistance experience more cancer-induced pain and are at more risk of emotional and behavioral disruptions correlated with CRF. However, other studies implied a potentially paradoxical impact of obesity and insulin resistance to reduce CRF symptoms. Despite the need for further investigation utilizing interventions to directly elucidate the mechanisms of cancer-related fatigue, current evidence demonstrates a correlation between obesity and/or insulin resistance and CRF, and suggests potential therapeutics for CRF by targeting obesity and/or obesity-related mediators.

Prenatal mood and anxiety disorders and associated cytokine changes

BACKGROUND

We examined whether women with prenatal mood and anxiety disorders would exhibit differential pro- and anti-inflammatory marker trajectories during the prenatal and postpartum periods compared to women without these disorders.

METHODS

Approximately 179 pregnant women participated in a longitudinal study conducted in two urban areas. Blood samples for inflammatory markers were collected at six study visits. The Structured Clinical Interview for the DSM-IV (SCID) was administered to participants scoring above cutoffs on anxiety and depression. Pregnant women with SCID Axis I diagnoses of mood and/or anxiety disorders were compared to other participants on inflammatory markers. Multilevel modeling tested associations between SCID diagnoses and within-person interleukin (IL)6 and IL10 trajectories.

RESULTS

Prenatal SCID diagnoses were associated with linear, quadratic and cubic change in IL6 from prenatal to postpartum timepoints. Women with a prenatal SCID diagnosis had steeper decreases and increases in IL6 during prenatal and postpartum periods. SCID diagnoses were associated with lower IL10 in mid-pregnancy to postpartum (b = -0.078, SE = 0.019; p = .015).

LIMITATIONS

Future studies would benefit from a larger sample size and a larger number of participants with SCID diagnoses. Future research should also examine whether different prenatal Axis 1 diagnoses are associated with different patterns of immune response in pregnancy.

CONCLUSIONS

Pregnant women with prenatal mood and anxiety disorders had greater fluctuations in IL6 across prenatal and postpartum periods and lower IL10 through pregnancy and postpartum. They may have different proinflammatory states that remain after birth without a reciprocal anti-inflammatory response.

Childhood Maltreatment and Immune Cell Gene Regulation during Adolescence: Transcriptomics Highlight Non-Classical Monocytes

Childhood maltreatment has been repeatedly linked to a higher incidence of health conditions with an underlying proinflammatory component, such as asthma, chronic obstructive pulmonary disease, stroke, and cardiovascular disease. Childhood maltreatment has also been linked to elevated systemic inflammation prior to the onset of disease. However, childhood maltreatment is highly comorbid with other risk factors which have also been linked to inflammation, namely major depression. The present analysis addresses this issue by assessing the association of maltreatment with genome-wide transcriptional profiling of immune cells collected from four orthogonal groups of adolescents (aged 13-17): maltreated and not maltreated in childhood, with and without major depressive disorder. Maltreatment and psychiatric history were determined using semi-structured clinical interviews and cross-validated using self-report questionnaires. Dried whole blood spots were collected from each participant (n = 133) and assayed to determine the extent to which maltreatment in childhood was associated with a higher prevalence of transcriptional activity among differentially expressed genes, specific immune cell subtypes, and up- or down-regulation of genes involved in immune function after accounting for current major depression. Maltreatment was associated with increased interferon regulatory factor (IRF) transcriptional activity (p = 0.03), as well as nuclear factor erythroid-2 related factor 1 (NRF1; p = 0.002) and MAF (p = 0.01) among up-regulated genes, and increased activity of nuclear factor kappa beta (NF-κB) among down-regulated genes (p = 0.01). Non-classical CD16+ monocytes were implicated in both the up- and down-regulated genes among maltreated adolescents. These data provide convergent evidence supporting the role of maltreatment in altering intracellular and molecular markers of immune function, as well as implicate monocyte/macrophage functions as mechanisms through which childhood maltreatment may shape lifelong immune development and function.

Prenatal exposure to maternal disadvantage-related inflammatory biomarkers: associations with neonatal white matter microstructure

Prenatal exposure to heightened maternal inflammation has been associated with adverse neurodevelopmental outcomes, including atypical brain maturation and psychiatric illness. In mothers experiencing socioeconomic disadvantage, immune activation can be a product of the chronic stress inherent to such environmental hardship. While growing preclinical and clinical evidence has shown links between altered neonatal brain development and increased inflammatory states in utero, the potential mechanism by which socioeconomic disadvantage differentially impacts neural-immune crosstalk remains unclear. In the current study, we investigated associations between socioeconomic disadvantage, gestational inflammation, and neonatal white matter microstructure in 320 mother-infant dyads over-sampled for poverty. We analyzed maternal serum levels of four cytokines (IL-6, IL-8, IL-10, TNF-α) over the course of pregnancy in relation to offspring white matter microstructure and socioeconomic disadvantage. Higher average maternal IL-6 was associated with very low socioeconomic status (SES; INR < 200% poverty line) and lower neonatal corticospinal fractional anisotropy (FA) and lower uncinate axial diffusivity (AD). No other cytokine was associated with SES. Higher average maternal IL-10 was associated with lower FA and higher radial diffusivity (RD) in corpus callosum and corticospinal tracts, higher optic radiation RD, lower uncinate AD, and lower FA in inferior fronto-occipital fasciculus and anterior limb of internal capsule tracts. SES moderated the relationship between average maternal TNF-α levels during gestation and neonatal white matter diffusivity. When these interactions were decomposed, the patterns indicated that this association was significant and positive among very low SES neonates, whereby TNF-α was inversely and significantly associated with inferior cingulum AD. By contrast, among the more advantaged neonates (lower-to-higher SES [INR ≥ 200% poverty line]), TNF-α was positively and significantly associated with superior cingulum AD. Taken together, these findings suggest that the relationship between prenatal cytokine exposure and white matter microstructure differs as a function of SES. These patterns are consistent with a scenario where gestational inflammation's effects on white matter development diverge depending on the availability of foundational resources in utero.

The Psychoneuroimmunological Model of Moral Distress and Health in Healthcare Workers: Toward Individual and System-Level Solutions

Healthcare is presently experiencing a global workforce crisis, marked by the inability of hospitals to retain qualified healthcare workers. Indeed, poor working conditions and staff shortages have contributed to structural collapse and placed a heavy toll on healthcare workers' (HCWs) well-being, with many suffering from stress, exhaustion, demoralization, and burnout. An additional factor driving qualified HCWs away is the repeated experience of moral distress, or the inability to act according to internally held moral values and perceived ethical obligations due to internal and external constraints. Despite general awareness of this crisis, we currently lack an organized understanding of how stress leads to poor health, wellbeing, and performance in healthcare workers. To address this critical issue, we first review the literature on moral distress, stress, and health in HCWs. Second, we summarize the biobehavioral pathways linking occupational and interpersonal stressors to health in this population, focusing on neuroendocrine, immune, genetic, and epigenetic processes. Third, we propose a novel Psychoneuroimmunological Model of Moral Distress and Health in HCWs based on this literature. Finally, we discuss evidence-based individual- and system-level interventions for preventing stress and promoting resilience at work. Throughout this review, we underscore that stress levels in HCWs are a major public health concern, and that a combination of system-level and individual-level interventions are necessary to address preventable health care harm and foster resilience in this population, including new health policies, mental health initiatives, and additional translational research.

Neuroimmune mechanisms connecting violence with internalizing symptoms: A high-dimensional multimodal mediation analysis

Violence exposure is associated with worsening anxiety and depression symptoms among adolescents. Mechanistically, social defeat stress models in mice indicate that violence increases peripherally derived macrophages in threat appraisal regions of the brain, which have been causally linked to anxious behavior. In the present study, we investigate if there is a path connecting violence exposure with internalizing symptom severity through peripheral inflammation and amygdala connectivity. Two hundred and thirty-three adolescents, ages 12-15, from the Chicago area completed clinical assessments, immune assays and neuroimaging. A high-dimensional multimodal mediation model was fit, using violence exposure as the predictor, 12 immune variables as the first set of mediators and 288 amygdala connectivity variables as the second set, and internalizing symptoms as the primary outcome measure. 56.2% of the sample had been exposed to violence in their lifetime. Amygdala-hippocampus connectivity mediated the association between violence exposure and internalizing symptoms (ζ ̂ Hipp π ̂ Hipp = 0.059 $$ {\hat{\zeta}}_{\mathrm{Hipp}}{\hat{\pi}}_{\mathrm{Hipp}}=0.059 $$ ,95 % CI boot = 0.009,0.134 $$ 95\%{\mathrm{CI}}_{\mathrm{boot}}=\left[\mathrm{0.009,0.134}\right] $$ ). There was no evidence that inflammation or inflammation and amygdala connectivity in tandem mediated the association. Considering the amygdala and the hippocampus work together to encode, consolidate, and retrieve contextual fear memories, violence exposure may be associated with greater connectivity between the amygdala and the hippocampus because it could be adaptive for the amygdala and the hippocampus to be in greater communication following violence exposure to facilitate evaluation of contextual threat cues. Therefore, chronic elevations of amygdala-hippocampal connectivity may indicate persistent vigilance that leads to internalizing symptoms.