Brain motor and fear circuits regulate leukocytes during acute stress

Neural-activity-regulated and glia-mediated control of brain lymphatic development

The nervous system regulates peripheral immune responses under physiological and pathological conditions, but the brain's impact on immune system development remains unknown. Meningeal mural lymphatic endothelial cells (muLECs), embedded in the leptomeninges, form an immune niche surrounding the brain that contributes to brain immunosurveillance. Here, we report that the brain controls the development of muLECs via a specialized glial subpopulation, slc6a11b+ radial astrocytes (RAs), a process modulated by neural activity in zebrafish. slc6a11b+ RAs, with processes extending to the meninges, govern muLEC formation by expressing vascular endothelial growth factor C (vegfc). Moreover, neural activity regulates muLEC development, and this regulation requires Vegfc in slc6a11b+ RAs. Intriguingly, slc6a11b+ RAs cooperate with calcium-binding EGF domain 1 (ccbe1)+ fibroblasts to restrict muLEC growth on the brain surface via controlling mature Vegfc distribution. Thus, our study uncovers a glia-mediated and neural-activity-regulated control of brain lymphatic development and highlights the importance of inter-tissue cellular cooperation in development.

Extraction technology, component analysis, and the immunomodulatory effects in immunosuppressed broilers of total flavonoids extract from the thorns of Gleditsia sinensis Lam

Spina Gleditsiae is the dry thorns from Gleditsia sinensis Lam. (G. sinensis), exhibits the effect of reducing swelling and toxins, and draining pus. Flavonoids are the primary active constituents of Spina Gleditsiae, but their extraction technology has not been studied systematically. Relevant studies revealed that Spina Gleditsiae shown certain immunomodulatory effects, but its mechanism was still unclear. This research was carried out about the extraction process, chemical composition, and the effects on the immune function of total flavonoids extract (TFE). The extraction conditions of TFE were investigated by response surface methodology, and the major components were preliminarily analyzed and inferred by ultra performance liquid chromatography- quadrupole-time-of-flight-mass spectrum method. The immunomodulatory effect of TFE was evaluated by cyclophosphamide induced immunosuppressed broilers. The yield of TFE was 1.80 % under the following optimized conditions: ethanol concentration 50 %, extraction time 20 min, and the ratio of solvent to material 50:1 ml/g. In addition, the main chemical components in the TFE have been preliminarily identified based on related literature and mass spectrometry information. Meanwhile, the TFE could mitigate the immunosuppressive state caused by cyclophosphamide in broilers by improving the histomorphology of immune organs, increasing the index of immune organ, elevating the serum levels of IL-2, IFN-β, and IFN-γ, and raising the titer of Newcastle disease antibodies in the serum. Furthermore, the immunoregulatory effects of these flavonoids were found to be closely related to the enhancement of the relative expression level of key genes and proteins in the TLR4-MyD88/TICAM-NF-κB signaling pathway. The findings of the study suggest that TFE derived from the thorns of G. sinensis holds promise as an enhanced traditional Chinese medicine with the capability to potentially bolster immune function.

Metabolic and Immune Crosstalk in Cardiovascular Disease

Cardiovascular diseases including atherosclerosis and heart failure, arise from the intricate interplay of metabolic, immune, and neural dysregulation within vascular and cardiac tissues: This review focuses on integrating recent advances in metabolic and immune crosstalk of the cardiac vasculature that affects cardiometabolic health and disease progression. Coronary and lymphatic endothelial cells regulate cardiac metabolism, and their dysfunction is linked to cardiovascular diseases. Lymphatics maintain tissue homeostasis, including clearing metabolic waste, lipids, and immune cells, and their maladaptation in metabolic diseases worsens outcomes. Altered vascular endothelial metabolism in heart failure drives immune-mediated inflammation, fibrosis, and adverse cardiac remodeling. Concurrently, artery tertiary lymphoid organs formed in the adventitia of advanced atherosclerotic arteries, serve as pivotal neuroimmune hubs, coordinating local immunity through T and B cell activation and neurovascular signaling via artery-brain circuits. T cells within plaques and artery tertiary lymphoid organs undergo clonal expansion as a result of peripheral tolerance breakdown, with proinflammatory CD4+ and CD8+ subsets amplifying atherosclerosis, effects further shaped by systemic immune activation. Therapeutic strategies targeting endothelial cell metabolism, lymphatic dysfunction, neuroimmune crosstalk, and T cell plasticity hold promise for integrated cardiovascular disease management.

Neural Mechanisms in Cardiovascular Health and Disease

Although the neurocardiac axis is central to cardiovascular homeostasis, its dysregulation drives heart failure and cardiometabolic diseases. This review examines the bidirectional interplay between the autonomic nervous system and the heart, highlighting the role of this interplay in disease progression and its therapeutic potential. The autonomic nervous system modulates cardiac function and vascular tone through its sympathetic and parasympathetic branches. However, in heart failure, chronic sympathetic overdrive and parasympathetic withdrawal exacerbate myocardial remodeling and metabolic dysfunction, both of which are exacerbated by cardiometabolic conditions such as obesity and diabetes. These conditions are increasingly recognized to impair neurocardiac regulation, thereby promoting inflammation and adverse outcomes. An important emerging area concerns neuroimmune control, in which the brain orchestrates systemic inflammation through circuits involving the bone marrow, spleen, and other organs, thereby amplifying cardiovascular damage. This neuroimmune axis integrates peripheral signals to influence immune responses that contribute to disease progression. Lifestyle factors, such as stress, sleep, exercise, and diet, affect autonomic and immune balance and, thus, cardiovascular disease. Therapeutically, targeting neurocardiac and neuroimmune pathways pharmacologically or via neuromodulation (eg, vagal or splenic nerve stimulation) offers promise although the clinical translation of the latter remains challenging. In this review, we synthesize preclinical and clinical data to highlight the neurocardiac axis as a critical nexus in heart failure and cardiometabolic disease. Harnessing neuroimmune and neurocardiac interactions may inform precision approaches to reduce the burden of these conditions.

Astrocyte-derived CCL5-mediated CCR5+ neutrophil infiltration drives depression pathogenesis

Cross-talk between the nervous and immune systems is involved in neurological diseases. However, their potential interplay in depression has yet to be elucidated. Here, using single-cell RNA and neutrophil SMART RNA sequencing, we showed that CCR5+ neutrophils were significantly increased in patients with depression and preferentially migrated to the hippocampus in a mouse model of depression. Infiltrated neutrophils engulf neuronal spines and subsequently promote depressive symptoms in male mice. Furthermore, by genetic or pharmacologic disruption, we identified a chemotactic effect of the astrocyte-derived chemokine CCL5 on mediating the infiltration of CCR5+ neutrophils and behavioral disorders in male depressed mice. Our findings therefore highlight the critical role of neutrophils in depression pathogenesis and astrocytes in mediating the dysregulation of innate immune responses and suggest that inhibition of CCL5/CCR5-mediated neutrophil infiltration represents a potential therapeutic strategy for noninfectious brain diseases such as depression.

Sleep deprivation-induced sympathetic activation promotes pro-tumoral macrophage phenotype via the ADRB2/KLF4 pathway to facilitate NSCLC metastasis

Sleep deprivation is one of concomitant symptoms of cancer patients, particularly those with non-small cell lung cancer (NSCLC). The potential effect of sleep deprivation on tumor progression and underlying mechanisms remain to be fully investigated. Using a sleep-deprived tumor-bearing mouse model, we found that sleep deprivation altered immune cell composition and regulated pro-tumoral M2 macrophage polarization by the sympathetic nervous system. Furthermore, we identified a role of catecholaminergic neurons in the rostral ventrolateral medulla (RVLM) in influencing NSCLC metastasis. Clinical analyses revealed a correlation between sympathetic-related indicators and poor prognosis. Mechanistically, our findings indicate that sleep deprivation facilitates the polarization of pro-tumoral macrophages by upregulating β2-adrenergic receptor (ADRB2), which subsequently enhances the expression of Kruppel-like transcription factor 4 (KLF4) through the JAK1/STAT6 phosphorylation pathway. These findings highlight a neuro-immune mechanism linking sleep deprivation to NSCLC metastasis, suggesting that targeting the ADRB2/KLF4 axis could improve outcomes for sleep-deprived NSCLC patients.

Cross-regulation between the nervous system and type 2 immunity

Interactions between the nervous and immune systems are critical to healthy physiology and are altered in many human diseases. Many of the major players in type 2 immune responses, including type 2 lymphocytes and cytokines, mast cells, and immunoglobulin E, have been implicated in neuronal function and behavior. Conversely, neurons in both the central and peripheral nervous systems can affect type 2 immune responses and behaviors relevant to allergy, such as food avoidance. Defining this complex circuitry and its molecular intermediates in physiology may reveal type 2 immunomodulators that can be harnessed for therapeutic benefit in neurologic diseases including Alzheimer's disease, brain injury, and neurodevelopmental disorders. Conversely, modulation of the nervous system may be an important adjunct to treating immunologic disorders including atopic dermatitis, asthma, and food allergy. This Review covers recent work defining how the nervous system can both regulate and be regulated by type 2 immune responses.

Complex neural-immune interactions shape glioma immunotherapy

Rich neural-immune interactions in the central nervous system (CNS) shape its function and create a unique immunological microenvironment for immunotherapy in CNS malignancies. Far from the now-debunked concept of CNS "immune privilege," it is now understood that unique immunological niches and constant immune surveillance of the brain contribute in multifaceted ways to brain health and robustly influence immunotherapy approaches for CNS cancers. Challenges include immune-suppressive and neurotoxicity-promoting crosstalk between brain, immune, and tumor cells. Developing effective immunotherapies for cancers of the nervous system will require a deeper understanding of these neural-immune-malignant cell interactions. Here, we review progress and challenges in immunotherapy for gliomas of the brain and spinal cord in light of these unique neural-immune interactions and highlight future work needed to optimize promising immunotherapies for gliomas.

The brain-body circuit mediates acute stress-induced antiinflammatory reflex in bacterial cystitis by suppressing ILC2 activation

Urinary tract infections (UTIs) are one of the most commonly encountered infections in clinical practice, in which psychological stress is a critical pathological contributor to modulate immune function. However, mechanistic pathways linking stress networks in the brain to bladder infection remain poorly understood. In this study, we discovered that acute stress treatment suppressed bladder inflammation in mice with UTIs, and a substantial number of neurons showing overlap between inflammation-associated markers and retrograde labeling were observed in the paraventricular nucleus (PVN) brain region of these mice. Activation of the PVN alleviated uropathogenic Escherichia coli-induced bladder inflammatory response. Moreover, a blocked hypothalamic-pituitary-adrenal axis reversed the antiinflammatory reflex mediated by acute stress, suggesting that glucocorticoids may modulate UTIs through the brain-body circuit. Single-cell RNA-Seq of bladder immune cells revealed that type 2 innate lymphoid (ILC2) cells expressed abundant levels of glucocorticoid receptor. The activation of the PVN effectively inhibited the expression of the pro-inflammatory cytokine colony-stimulating factor 2 by ILC2 cells through direct regulation of cell-intrinsic glucocorticoid signaling. Ultimately, our study has implications for the positioning of the brain-body circuit for UTI treatment.

Enhanced engraftment of human haematopoietic stem cells via mechanical remodelling mediated by the corticotropin-releasing hormone

The engraftment of haematopoietic stem and progenitor cells (HSPCs), particularly in cord-blood transplants, remains challenging. Here we report the role of the corticotropin-releasing hormone (CRH) in enhancing the homing and engraftment of human-cord-blood HSPCs in bone marrow through mechanical remodelling. By using microfluidics, intravital two-photon imaging and long-term-engraftment assays, we show that treatment with CRH substantially enhances HSPC adhesion, motility and mechanical remodelling, ultimately leading to improved bone-marrow homing and engraftment in immunodeficient mice. CRH induces Ras homologue gene family member A (RhoA)-dependent nuclear translocation of the yes-associated protein (YAP), which upregulates the expression of genes encoding extracellular-matrix proteins (notably, thrombospondin-2 (THBS2)). This process guides the mechanical remodelling of HSPCs via modulation of the actin cytoskeleton and the extracellular matrix, with THBS2 interacting with the integrin αvβ3 and coordinating the nuclear translocation of YAP upon CRH/CRH-receptor-1 (CRH/CRHR1) signalling. Overall, the CRH/CRHR1/RhoA/YAP/THBS2/αvβ3 axis has a central role in modulating HSPC behaviour via a mechanical feedback loop involving THBS2, αvβ3, the actin cytoskeleton and YAP signalling. Our findings may suggest avenues for optimizing the transplantation of HSPCs.

Psychedelic control of neuroimmune interactions governing fear

Neuroimmune interactions-signals transmitted between immune and brain cells-regulate many aspects of tissue physiology1, including responses to psychological stress2-5, which can predispose individuals to develop neuropsychiatric diseases6-9. Still, the interactions between haematopoietic and brain-resident cells that influence complex behaviours are poorly understood. Here, we use a combination of genomic and behavioural screens to show that astrocytes in the amygdala limit stress-induced fear behaviour through epidermal growth factor receptor (EGFR). Mechanistically, EGFR expression in amygdala astrocytes inhibits a stress-induced, pro-inflammatory signal-transduction cascade that facilitates neuron-glial crosstalk and stress-induced fear behaviour through the orphan nuclear receptor NR2F2 in amygdala neurons. In turn, decreased EGFR signalling and fear behaviour are associated with the recruitment of meningeal monocytes during chronic stress. This set of neuroimmune interactions is therapeutically targetable through the administration of psychedelic compounds, which reversed the accumulation of monocytes in the brain meninges along with fear behaviour. Together with validation in clinical samples, these data suggest that psychedelics can be used to target neuroimmune interactions relevant to neuropsychiatric disorders and potentially other inflammatory diseases.

The Interplay of Chronic Stress and Cancer: Pathophysiology and Implications for Integrated Care

BACKGROUND

Cancer-associated depression is a multifaceted condition that arises from the interplay of biological, psychological, and social factors in individuals diagnosed with cancer. Understanding this condition involves exploring how cancer and its treatments can precipitate depressive symptoms and the mechanisms behind this association. Chronic stress, inflammation, and immunological responses play a crucial role in the development of both cancer and depression. The objective of this review is to describe and synthesize information on the complex interactions between chronic stress, inflammation, immunological responses, and cancer development. Additionally, it aims to review existing evidence regarding mechanisms such as neurotransmitter imbalances, structural brain changes, and genetic predispositions as key contributors to depression in cancer patients.

RECENT FINDINGS

A comprehensive literature search on Cancer-associated Depression was conducted in electronic databases, including APA PsycINFO, Medline, Google Scholar, Embase, PubMed, Scopus, and Web of Science. The research focused on understanding the potential relationship between stress-induced depression and cancer by examining neurochemical, anatomical, immunological, genetic, and psychological changes. The findings revealed a compilation of both quantitative and qualitative studies on depression in cancer patients. Evidence suggested a potential link between cancer-induced stress and depression, with increased levels of proinflammatory cytokines (such as IL-6) and dysregulation of neurotransmitters, including serotonin, contributing to the onset of depression. Furthermore, studies indicated that antidepressants, along with psychological interventions, were effective in managing depression among cancer patients.

CONCLUSION

This narrative review provides insights into the importance of integrating oncology and mental health services to address the psychosocial needs of cancer patients. Future research should focus on the bidirectional interactions between stress and cancer, aiming to improve cancer care by incorporating mental health support. Addressing the mental health aspects of cancer treatment can significantly enhance patient outcomes and overall quality of life.

Lactobacillus murinus ZNL-13 Modulates Intestinal Barrier Damage and Gut Microbiota in Cyclophosphamide-Induced Immunosuppressed Mice

Cyclophosphamide (CTX) is a widely used anticancer drug in clinical practice; however, its administration can lead to gastrointestinal damage and immune suppression. Lactobacillus murinus (L. murinus) has been shown to regulate immune cell activity and protect the gastrointestinal system, showing potential application as a functional food. The objective of this study was to investigate the effects of L. murinus ZNL-13 on CTX-induced intestinal mucosal injury and gut microbiota in mice. The results demonstrated that L. murinus ZNL-13 significantly alleviated weight loss and intestinal pathological damage. Moreover, in CTX-induced intestinal injury mice, L. murinus ZNL-13 enhanced the release of immune factors, suppressed cell apoptosis, and protected the intestinal mucosal barrier. Additionally, it activated the TLR4/NF-κB pathway, thereby promoting immune cell activity. Furthermore, L. murinus ZNL-13 contributed to the restoration of gut microbial homeostasis by increasing the relative abundance of short-chain fatty acid-producing bacteria. Taken together, this investigation highlights the potential of L. murinus ZNL-13 in protecting the intestinal barrier and enhancing immune function while laying the groundwork for its development as a novel probiotic and functional food.

Neuroimmune circuits in the plaque and bone marrow regulate atherosclerosis

Atherosclerosis remains the leading cause of death globally. Although its focal pathology is atheroma that develops in arterial walls, atherosclerosis is a systemic disease involving contributions by many organs and tissues. It is now established that the immune system causally contributes to all phases of atherosclerosis. Recent and emerging evidence positions the nervous system as a key modulator of inflammatory processes that underlie atherosclerosis. This neuroimmune cross-talk, we are learning, is bidirectional, and immune-regulated afferent signalling is becoming increasingly recognized in atherosclerosis. Here, we summarize data and concepts that link the immune and nervous systems in atherosclerosis by focusing on two important sites, the arterial vessel and the bone marrow.

Heart-brain axis in health and disease: role of innate and adaptive immunity

The importance of the brain-heart interaction has been increasingly recognized as a critical physiological axis that is altered in disease. In this review, we explore the intricate relationship between the central nervous system and cardiovascular health, focusing particularly on immunological mechanisms that influence the course of both neurological and cardiovascular diseases. While previous studies have established a key role of the autonomic nervous system (ANS) in linking brain and the heart, more recent studies have expanded our understanding of the multifaceted inter-organ interactions. As such, circulating mediators include immune cells of the adaptive and innate immune system and their secreted immunogenic factors have come into the focus as mediators along this bidirectional communication. Hence, in this review we briefly discuss the contribution of the ANS and then focus on innate and adaptive immune mechanisms along the heart-to-brain and brain-to-heart axes, illustrating how cardiovascular diseases affect cognitive functions and how brain pathologies lead to cardiac complications.

Brain sensing of metabolic state regulates circulating monocytes

Changes in energy availability alter the dynamics of circulating immune cells. The existing view is that these effects are due to altered nutrient levels affecting peripheral tissue metabolism. Here, using mice and genetic approaches to manipulate the activity of distinct molecularly defined neurons, we show that the brain's perception of hunger and satiety alone is sufficient to drive these immune changes. Hunger-promoting Agouti-related peptide (AgRP) neurons in the hypothalamus were both sufficient and necessary to reduce circulating Ly6CHi classical monocytes during fasting. Mechanistically, these neurons suppressed hepatic mammalian target of rapamycin signaling via sympathetic regulation, decreasing circulating chemokine ligand 2 and monocyte numbers. AgRP neuron-induced corticosterone release and glucocorticoid receptor activation played a permissive role in this process. These changes in monocyte dynamics can occur independently of actual nutrient levels, revealing an unexpected brain-mediated control of peripheral immunity in response to perceived variation in energy state.

Progress on Direct Regulation of Systemic Immunity by the Central Nervous System

This article reviews the research progress on the direct regulation of the immune system by the central nervous system (CNS). The traditional "neuro-endocrine-immune" network model has confirmed the close connection between the CNS and the immune system. However, due to the complex mediating role of the endocrine system, its application in clinical treatment is limited. In recent years, the direct regulation of the peripheral immune system through the CNS has provided new methods for the clinical treatment of neuroimmune-related diseases. This article analyzes the changes in the peripheral immune system after CNS injury and summarizes the effects of various stimulation methods, including transcranial magnetic stimulation, transcranial electrical stimulation, deep brain stimulation, spinal cord stimulation, and vagus nerve stimulation, on the peripheral immune system. Additionally, it explores the clinical research progress and future development directions of these stimulation methods. It is proposed that these neural regulation techniques exhibit positive effects in reducing peripheral inflammation, protecting immune cells and organ functions, and improving immunosuppressive states, providing new perspectives and therapeutic potential for the treatment of immune-related diseases.

Androgen receptors in corticotropin-releasing hormone neurons mediate the sexual dimorphism in restraint-induced thymic atrophy

Sexual dimorphism in immune responses is well documented, but the underlying mechanisms remain incompletely understood. Here, we identified a subset of corticotropin-releasing hormone (CRH) neurons that express androgen receptors (ARs) as key mediators of sex differences in restraint-induced immunosuppression. Mechanistically, androgens directly activate AR-positive CRH neurons, enhancing the hypothalamic-pituitary-adrenal axis activation. This results in elevated corticosterone levels in response to restraint stress, leading to increased immune cell apoptosis and immune organ atrophy in male mice. Conditional knockout of ARs in CRH neurons eliminated this sexual dimorphism, highlighting ARs in CRH neurons as pivotal regulators of sex-specific immune responses to stress.

Stress-experienced monocytes/macrophages lose anti-inflammatory function via β2-adrenergic receptor in skin allergic inflammation

BACKGROUND

Psychological stress can exacerbate the development of allergies; however, the underlying mechanisms remain poorly understood. IgE-mediated cutaneous allergic inflammation (IgE-CAI) is a basophil-dependent skin allergy with eosinophil infiltration at inflammatory sites. Its resolution involves anti-inflammatory programmed death ligand 2 (PD-L2)-positive macrophages.

OBJECTIVE

This study sought to elucidate the cellular and molecular mechanisms by which psychological stress exacerbates IgE-CAI.

METHODS

Neural tissue involved in stress-induced IgE-CAI exacerbation was identified by performing denervation and brain destruction experiments in mice. Immune cell transplantation, RNA sequencing, flow cytometry, and ELISA were used to identify and characterize immune cells with stress-altered functioning, followed by identification of key factors involved in IgE-CAI exacerbation.

RESULTS

Stress-induced exacerbation of IgE-CAI was found to be sympathetic and β2-adrenergic receptor (Adrb2)-dependent. Adoptive transfer experiments revealed that stress diminished the anti-inflammatory functions of PD-L2-positive macrophages through Adrb2, exacerbating the inflammation. RNA sequencing analysis indicated that PD-L2-positive macrophages in stressed mice exhibit reduced expression of efferocytosis-related genes, including Gas6 and MerTK. Consequently, the efferocytic capacity of these macrophages decreased, resulting in increased numbers of dead cells in the lesions. The exacerbation and upregulation of Ccl24 expression in IgE-CAI skin lesions were countered by a Caspase-1 inhibitor.

CONCLUSIONS

Psychological stress diminishes the efferocytotic capacity of PD-L2-positive macrophages, causing an accumulation of dead cells. This, in turn, heightens eosinophil infiltration through Caspase-1-dependent production of CCL24, exacerbating IgE-CAI.

Unveiling the role of lncRNA ERDR1 in immune cell regulation

Long non-coding RNAs (lncRNAs) are a class of RNA molecules that exceed 200 nucleotides in length and lack the capacity to encode proteins. In recent years, there has been a surge of interest in lncRNA research, leading to the discovery of their diverse structures and functions. This review focused on elucidating the regulatory roles of lncRNA erythroid differentiation regulatory 1 (Erdr1) within immune cells and its involvement in related disorders. By synthesizing findings from recent studies sourced from PubMed, this paper examined the biological functions and underlying mechanisms by which lncRNA Erdr1 influences immune cells and contributes to various diseases. Emerging research highlights that lncRNA Erdr1 exerts significant effects on the functionality of immune cells, particularly T lymphocytes (T cells), natural killer (NK) cells, and macrophages. Furthermore, Erdr1 has been implicated in the mitigation of several diseases, including acne, wound healing, osteoarthritis, melanoma, gastric cancer, obesity, and autism. Given its complex biological functions and mechanisms, Erdr1 presents itself as a promising biomarker and a potential therapeutic target for a range of immune cell-related disorders.

Integrated control of leukocyte compartments as a feature of adaptive physiology

As a highly diverse and mobile organ, the immune system is uniquely equipped to participate in tissue responses in a tunable manner, depending on the number, type, and nature of cells deployed to the respective organ. Most acute organismal stressors that threaten survival-predation, infection, poisoning, and others-induce pronounced redistribution of immune cells across tissue compartments. Here, we review the current understanding of leukocyte compartmentalization under homeostatic and noxious conditions. We argue that leukocyte shuttling between compartments is a function of local tissue demands, which are linked to the organ's contribution to adaptive physiology at steady state and upon challenge. We highlight the neuroendocrine signals that relay and organize this trafficking behavior and outline mechanisms underlying the functional diversification of leukocyte responses. In this context, we discuss important areas of future inquiry and the implications of this scientific space for clinical medicine in the era of targeted immunomodulation.

Dual Role of α-MSH in Colitis Progression: Mediating Neutrophil Differentiation via Bone Marrow

Background

Inflammatory bowel disease (IBD) comprises a group of autoimmune disorders characterized by chronicity and resistance to cure, with an unknown etiology. Recent studies on the brain-gut axis suggest that the central nervous system (CNS), particularly the hypothalamic-pituitary axis (HPA), may play a crucial role in modulating the immune system and influencing disease progression. However, the specific role and mechanism of the HPA in IBD pathogenesis remain unclear. This study aims to investigate the alterations in the HPA and its potential roles during IBD development.

Methods

We utilized a dextran sodium sulfate (DSS)-induced colitis model in mice and employed immunofluorescence, real-time quantitative PCR (RT-qPCR), enzyme-linked immunosorbent assay (ELISA), among other techniques, to evaluate the impact of colitis on the HPA. Additionally, we used flow cytometry, adeno-associated virus-mediated gene silence, parabiosis and single-cell RNA sequencing to uncover the specific roles and mechanisms of the HPA in colitis.

Results

Our results indicate that colitis activates HPA secretion and increases α-MSH. α-MSH acts on the MC5R present on the surface of hematopoietic stem cells (HSCs) in the bone marrow, altering the bone marrow microenvironment and promoting HSCs proliferation and differentiation into neutrophils. This process enhances the clearance of pathogenic microorganisms during the acute phase of colitis, while inducing sustained inflammatory responses during the remission phase.

Conclusion

In summary, our study demonstrates the dual role of HPA activation and α-MSH secretion induced by colitis in the pathogenesis of IBD. These findings offer vital guidance for optimizing personalized treatment of IBD, emphasizing the importance of carefully managing the timing and dosage of α-MSH for its effective clinical application.

The neuroimmune connectome in health and disease

The nervous and immune systems have complementary roles in the adaptation of organisms to environmental changes. However, the mechanisms that mediate cross-talk between the nervous and immune systems, called neuroimmune interactions, are poorly understood. In this Review, we summarize advances in the understanding of neuroimmune communication, with a principal focus on the central nervous system (CNS): its response to immune signals and the immunological consequences of CNS activity. We highlight these themes primarily as they relate to neurological diseases, the control of immunity, and the regulation of complex behaviours. We also consider the importance and challenges linked to the study of the neuroimmune connectome, which is defined as the totality of neuroimmune interactions in the body, because this provides a conceptual framework to identify mechanisms of disease pathogenesis and therapeutic approaches. Finally, we discuss how the latest techniques can advance our understanding of the neuroimmune connectome, and highlight the outstanding questions in the field.

Dysfunction in neuro-mesenchymal units impairs the development of bone marrow B cells in mice with anxiety

The reduction in B lymphocytes observed in individuals with anxiety disorders may compromise antiviral responses, yet the precise mechanisms behind this decline remain unclear. While elevated glucocorticoid levels have been suggested as contributing factors, anxiety disorders are associated with diminished glucocorticoid signaling. Given that autonomic nervous system dysfunction is a hallmark of anxiety disorders, we established an anxiety-related behavior mouse model by stimulating C1 neurons in the rostral ventrolateral medulla. Using this model, we confirmed that sustained activation of sympathetic nerves can disrupt adaptive immunity, particularly affecting the development of B cells. The underlying mechanism involves the control of B cell development through neuro-mesenchymal units within the bone marrow, with mesenchyme-derived CXCL12 playing a pivotal role in this regulatory process. Intriguingly, targeting these neuro-mesenchymal units not only restored B cell development but also alleviated anxiety-like behavior in the mice. Our study provides compelling evidence regarding the regulatory role of neuro-mesenchymal units in the development of B cells within the bone marrow. Additionally, our findings suggest that anxiety disorders can create a vicious cycle, perpetuating ongoing mental and immunological damage and ultimately leading to irreversible harm. To break this cycle, it is essential to focus on the dysfunction of immune cells and strive to restore immune homeostasis in individuals suffering from anxiety disorders.

Meningeal neutrophil immune signaling influences behavioral adaptation following threat

Social creatures must attend to threat signals from conspecifics and respond appropriately, both behaviorally and physiologically. In this work, we show in mice a threat-sensitive immune mechanism that orchestrates psychological processes and is amenable to social modulation. Repeated encounters with socially cued threats triggered meningeal neutrophil (MN) priming preferentially in males. MN activity was correlated with attenuated defensive responses to cues. Canonical neutrophil-specific activation marker CD177 was upregulated after social threat cueing, and its genetic ablation abrogated male behavioral phenotypes. CD177 signals favored meningeal T helper (Th)1-like immune bias, which blunted neural response to threatening stimuli by enhancing intrinsic GABAergic inhibition within the prelimbic cortex via interferon-gamma (IFN-γ). MN signaling was sensitized by negative emotional states and governed by socially dependent androgen release. This male-biased hormone/neutrophil regulatory axis is seemingly conserved in humans. Our findings provide insights into how immune responses influence behavioral threat responses, suggesting a possible neuroimmune basis of emotional regulation.

Tau is a receptor with low affinity for glucocorticoids and is required for glucocorticoid-induced bone loss

Glucocorticoids (GCs) are the most prescribed anti-inflammatory and immunosuppressive drugs. However, their use is often limited by substantial side effects, such as GC-induced osteoporosis (GIO) with the underlying mechanisms still not fully understood. In this study, we identify Tau as a low-affinity binding receptor for GCs that plays a crucial role in GIO. Tau deficiency largely abolished bone loss induced by high-dose dexamethasone, a synthetic GC, in both inflammatory arthritis and GIO models. Furthermore, TRx0237, a Tau inhibitor identified from an FDA-approved drug library, effectively prevented GIO. Notably, combinatorial administration of TRx0237 and dexamethasone completely overcame the osteoporosis adverse effect of dexamethasone in treating inflammatory arthritis. These findings present Tau as a previously unrecognized GC receptor with low affinity, and provide potential strategies to mitigate a spectrum of GC-related adverse effects, particularly osteoporosis.

Chronic Stress-Induced and Tumor Derived SP1+ Exosomes Polarizing IL-1β+ Neutrophils to Increase Lung Metastasis of Breast Cancer

Chronic stress can significantly promote breast cancer progression. When exposed to chronic stress, exosomes released from neural and neuroendocrine cells in the central nervous system are enhanced and modified. However, whether tumor-derived exosomes (TDEs) are influenced by chronic stress and participate in chronic stress-mediated distant metastasis remains unclear. Here, it is shown that chronic stress remarkably facilitates the secretion of TDEs and modifies the contents of exosomes by activating the adrenergic β receptor in 4T1 tumor-bearing mice. Exosomes injection and blockade experiments indicate that exosomes play a crucial role in chronic stress-mediated lung metastasis of breast cancer. Chronic stress-induced TDEs are internalized by pulmonary neutrophils and strengthen neutrophil recruitment via the CXCL2 autocrine. In addition, the level of SP1 in TDEs increases, which favors the secretion of IL-1β by neutrophils through the activation of the TLR4-NFκβ pathway, ultimately aggravating lung metastasis of breast cancer. Collectively, this study provides a novel mechanism by which neutrophils within a pre-metastatic niche acquire their inflamed phenotype and establishes an important link among neuroendocrine changes, exosomes, immunity, and metastasis.

Unraveling the effect of recreational fear on inflammation: A prospective cohort field study

A fear reaction is fundamental for survival and naturally activates the adrenergic system, prompting an acute and vital flight-or-fight response. While sustained stress is associated with unhealthy low-grade inflammation, more acute and transient activation of the adrenergic system has been suggested to impact the immune system and subsequently attenuate low-grade inflammation, e.g. through cold exposure or hyperventilation. Voluntary exposure to frightening stimuli, such as scary entertainment, is another reliable activator of the adrenergic system, yet its impact on the immune system and low-grade inflammation is unknown. The objectives of this study are to i. assess proportional changes of participants with low-grade inflammation at and three days after a voluntary frightening event, and ii. explore mean value alterations in inflammatory markers and immune cells over time. We recruited adult participants among visitors to a real-life intense frightening haunted house attraction, located in Vejle, Denmark. The overall fright potential of the exposure was estimated through heart rate (HR) monitoring and self-reported levels of fear. Low-grade inflammation (defined as high sensitive C-reactive protein (hs-CRP) > 3 mg/L)) and immune cells (subtypes of leukocytes) were measured from blood samples immediately before, immediately after, and three days after the haunted house event. A total of 113 participants, 69 females (61.1 %), and 44 males (38.9 %), with a mean age of 29.7 (SD 10.1) were included in the analyses. The average duration of exposure was 50 min and 51 s, while the mean HR throughout the event was 111.1 BPM (mean SD 10.1), and the mean subjective reported scare level was 5.4 (SD 1.9) on a Likert scale ranging from 1 to 9. Twenty-two participants exhibited low-grade inflammation (hs-CRP > 3 mg/L) at the event, with 10 participants normalizing their hs-CRP levels three days post-event. Seven participants had normal hs-CRP levels at the event, but low-grade inflammation three days post-event. Thus, we found no proportional difference between participants with low-grade inflammation at the event (19.5 %) and three days after the event (16.8 %) (diff. -2.7 %; 95 % CI: -10.7 to 5.4, p = 0.47). For the 22 participants exhibiting low-grade inflammation at the event, 18 participants (82 %) decreased their hs-CRP levels, with a mean decrease in hs-CRP from 5.7 mg/L pre-event to 3.7 mg/L three days post-event (diff. -2.0, 95 % CI: -3.2 to -0.7, p = 0.003). Supporting an overall attenuation of inflammation, total leukocytes and lymphocytes decreased for both participants with low-grade inflammation and with normal inflammatory levels, when comparing levels pre- and three days post-event, although all mean levels remained within the normal range. Conclusively, we find no proportional differences in participants exhibiting low-grade inflammation (hs-CRP > 3) when comparing levels at and three days after exposure to a voluntary frightening event. However, explorative analyses suggest that recreational fear exposure may attenuate immune cells across the entire cohort (N = 113) and decrease hs-CRP levels for participants who exhibit low-grade inflammation at the event (N = 22).

Association of Ego Defense Mechanisms with Electrolyte and Inflammation Marker Levels, Interdialytic Weight Gain, Depression, Alexithymia, and Sleep Disorders in Patients Undergoing Chronic Hemodialysis

Background/Objectives: Ego defense mechanisms are subconscious processes that help individuals cope with stressors from both external and internal realities. They are divided into three levels based on their adaptive function. Patients undergoing chronic hemodialysis are those who have been treated with this method for longer than three months. Only a few studies have examined the defense mechanisms in hemodialysis patients. Our study aimed to examine the association between ego defense mechanisms and alexithymia, depression, and sleep disorders, as well as clinical and biochemical variables, in a group of 170 hemodialysis patients. Methods: We used the Defense Style Questionnaire-40, the Toronto Alexithymia Scale-26, the Pittsburgh Sleep Quality Index, and the Hamilton Depression Inventory as our analyses methods. Clinical and biochemical variables, along with interdialytic weight gain, were measured before the hemodialysis session. Results: There was a positive correlation between the affect displacement and dissociation with leukocyte levels (Spearman's rho = 0.192, p = 0.02; rho = 0.165, p = 0.04), and between autistic fantasy and phosphorus levels (rho = -0.163, p = 0.04). Depressive HD patients had higher levels of somatization, affect displacement, and splitting compared to the HD patients without depression (Man-Whitney U test, p = 0.005, p = 0.022, p = 0.045). There were higher levels of immature defense mechanisms in the group of patients with alexithymia than in the group without alexithymia (Mann-Whitney U test, p < 0.001). Conclusions: The immature defense mechanisms were our research model's strongest predictive factor of alexithymia (OR = 1.87, 95% CI 1.27 to 2.75).

Vasopressin drives aberrant myeloid differentiation of hematopoietic stem cells, contributing to depression in mice

Psychological stress is often linked to depression and can also impact the immune system, illustrating the interconnectedness of mental health and immune function. Hematopoietic stem cells (HSCs) can directly sense neuroendocrine signals in bone marrow and play a fundamental role in the maintenance of immune homeostasis. However, it is unclear how psychological stress impacts HSCs in depression. Here, we report that neuroendocrine factor arginine vasopressin (AVP) promotes myeloid-biased HSC differentiation by activating neutrophils. AVP administration increases neutrophil and Ly6Chi monocyte production by triggering HSCs that rely on intrinsic S100A9 in mice. When stimulated with AVP, neutrophils return to the bone marrow and release interleukin 36G (IL-36G), which interacts with interleukin 1 receptor-like 2 (IL-1RL2) on HSCs to produce neutrophils with high Elane expression that infiltrate the brain and induce neuroinflammation. Together, these findings define HSCs as a relay between psychological stress and myelopoiesis and identify the IL-36G-IL-1RL2 axis as a potential target for depression therapy.

A Prospective Cohort Study on the Effects of Repeated Acute Stress on Cortisol Awakening Response and Immune Function in Military Medical Students

Background: The cortisol awakening response (CAR) is a pivotal component of the body's stress response, yet its dynamics under repeated acute stress and its interplay with immune biomarkers remain inadequately understood. Methods: This study examined 80 second-year military medical students undergoing a 5-day intensive surgical simulation designed to elicit stress responses. Salivary samples were collected daily upon waking and 30 min thereafter to measure cortisol and a panel of cytokines using bead-based multiplex ELISA. Results: Analysis revealed a significant blunting of the CAR on the third day of training (p = 0.00006), followed by a recovery on the fourth day (p = 0.0005). Concurrently, specific cytokines such as CXCL1 (r = 0.2, p = 0.0005), IL-6 (r = 0.13, p = 0.02), IL-10 (r = 0.14, p = 0.02), and VEGF-A (r = 0.17, p = 0.003) displayed patterns correlating with the CAR, with increased strength of associations observed when assessing cytokine levels against the CAR of the preceding day (CXCL1 r = 0.41, p = 0.0002. IL-6 r = 0.38, p = 0.0006. IL-10 r = 0.3, p = 0.008. VEGF-A r = 0.41, p = 0.0002). Conclusions: These results suggest a temporal relationship between stress-induced cortisol dynamics and immune regulation. The CAR pattern demonstrated in this study may represent induction of and recovery from psychological burnout. Moreover, the observed cytokine associations provide insight into the mechanisms by which stress can influence immune function. The results may have broader implications for managing stress in high-performance environments, such as military and medical professions, and for identifying individuals at risk of stress-related immune suppression.

Brain-body physiology: Local, reflex, and central communication

Behavior is tightly synchronized with bodily physiology. Internal needs from the body drive behavior selection, while optimal behavior performance requires a coordinated physiological response. Internal state is dynamically represented by the nervous system to influence mood and emotion, and body-brain signals also direct responses to external sensory cues, enabling the organism to adapt and pursue its goals within an ever-changing environment. In this review, we examine the anatomy and function of the brain-body connection, manifested across local, reflex, and central regulation levels. We explore these hierarchical loops in the context of the immune system, specifically through the lens of immunoception, and discuss the impact of its dysregulation on human health.

Diversity of ancestral brainstem noradrenergic neurons across species and multiple biological factors

The brainstem region, locus coeruleus (LC), has been remarkably conserved across vertebrates. Evolution has woven the LC into wide-ranging neural circuits that influence functions as broad as autonomic systems, the stress response, nociception, sleep, and high-level cognition among others. Given this conservation, there is a strong possibility that LC activity is inherently similar across species, and furthermore that age, sex, and brain state influence LC activity similarly across species. The degree to which LC activity is homogenous across these factors, however, has never been assessed due to the small sample size of individual studies. Here, we pool data from 20 laboratories (1,855 neurons) and show diversity across both intrinsic and extrinsic factors such as species, age, sex and brain state. We use a negative binomial regression model to compare activity from male monkeys, and rats and mice of both sexes that were recorded across brain states from brain slices ex vivo or under different anesthetics or during wakefulness in vivo. LC activity differed due to complex interactions of species, sex, and brain state. The LC became more active during aging, independent of sex. Finally, in contrast to the foundational principle that all species express two distinct LC firing modes ("tonic" or "phasic"), we discovered great diversity within spontaneous LC firing patterns. Different factors were associated with higher incidence of some firing modes. We conclude that the activity of the evolutionarily-ancient LC is not conserved. Inherent differences due to age and species-sex-brain state interactions have implications for understanding the role of LC in species-specific naturalistic behavior, as well as in psychiatric disorders, cardiovascular disease, immunology, and metabolic disorders.

Looking Back to Move Forward: Research in Stress, Behavior, and Immune Function

BACKGROUND

From the original studies investigating the effects of adrenal gland secretion to modern high-throughput multidimensional analyses, stress research has been a topic of scientific interest spanning just over a century.

SUMMARY

The objective of this review was to provide historical context for influential discoveries, surprising findings, and preclinical models in stress-related neuroimmune research. Furthermore, we summarize this work and present a current understanding of the stress pathways and their effects on the immune system and behavior. We focus on recent work demonstrating stress-induced immune changes within the brain and highlight studies investigating stress effects on microglia. Lastly, we conclude with potential areas for future investigation concerning microglia heterogeneity, bone marrow niches, and sex differences.

KEY MESSAGES

Stress is a phenomenon that ties together not only the central and peripheral nervous system, but the immune system as well. The cumulative effects of stress can enhance or suppress immune function, based on the intensity and duration of the stressor. These stress-induced immune alterations are associated with neurobiological changes, including structural remodeling of neurons and decreased neurogenesis, and these contribute to the development of behavioral and cognitive deficits. As such, research in this field has revealed important insights into neuroimmune communication as well as molecular and cellular mediators of complex behaviors relevant to psychiatric disorders.

A brain-body feedback loop driving HPA-axis dysfunction in breast cancer

Breast cancer patients often exhibit disrupted circadian rhythms in circulating glucocorticoids (GCs), such as cortisol. This disruption correlates with reduced quality of life and higher cancer mortality 1-3 . The exact cause of this phenomenon - whether due to treatments, stress, age, co-morbidities, lifestyle factors, or the cancer itself remains unclear. Here, we demonstrate that primary breast cancer alone blunts host GC rhythms by disinhibiting neurons in the hypothalamus, and that circadian phase-specific neuromodulation of these neurons can attenuate tumor growth by enhancing anti-tumor immunity. We find that mice with mammary tumors exhibit blunted GC rhythms before tumors are palpable, alongside increased activity in paraventricular hypothalamic neurons expressing corticotropin-releasing hormone (i.e., PVN CRH neurons). Tumor-bearing mice have fewer inhibitory synapses contacting PVN CRH neurons and reduced miniature inhibitory post-synaptic current (mIPSC) frequency, leading to net excitation. Tumor-bearing mice experience impaired negative feedback on GC production, but adrenal and pituitary gland functions are largely unaffected, indicating that alterations in PVN CRH neuronal activity are likely a primary cause of hypothalamic-pituitary-adrenal (HPA) axis dysfunction in breast cancer. Using chemogenetics (hM3Dq) to stimulate PVN CRH neurons at different circadian phases, we show that stimulation just before the light-to-dark transition restores normal GC rhythms and reduces tumor progression. These mice have significantly more effector T cells (CD8+) within the tumor than non-stimulated controls, and the anti-tumor effect of PVN CRH neuronal stimulation is absent in mice lacking CD8+ T cells. Our findings demonstrate that breast cancer distally regulates neurons in the hypothalamus that control output of the HPA axis and provide evidence that therapeutic targeting of these neurons could mitigate tumor progression.

Research trends on cancer neuroscience: a bibliometric and visualized analysis

Background

Recently, cancer neuroscience has become the focus for scientists. Interactions between the nervous system and cancer (both systemic and local) can regulate tumorigenesis, progression, treatment resistance, compromise of anti-cancer immunity, and provocation of tumor-promoting inflammation. We assessed the related research on cancer neuroscience through bibliometric analysis and explored the research status and hotspots from 2020 to 2024.

Methods

Publications on cancer neuroscience retrieved from the Web of Science Core Collection. CiteSpace, VOSviewer, and Scimago Graphica were used to analyze and visualize the result.

Results

A total of 744 publications were retrieved, with an upward trend in the overall number of articles published over the last 5 years. As it has the highest number of publications (n = 242) and citations (average 13.63 citations per article), the United States holds an absolute voice in the field of cancer neuroscience. The most productive organizations and journals were Shanghai Jiaotong University (n = 24) and Cancers (n = 45), respectively. Monje M (H-index = 53), Hondermarck H (H-index = 42), and Amit M (H-index = 39) were the three researchers who have contributed most to the field. From a global perspective, research hotspots in cancer neuroscience comprise nerve/neuron-tumor cell interactions, crosstalk between the nervous system and other components of the tumor microenvironment (such as immune cells), as well as the impact of tumors and tumor therapies on nervous system function.

Conclusion

The United States and European countries are dominating the field of cancer neuroscience, while developing countries such as China are growing rapidly but with limited impact. The next focal point in this field is likely to be neurotrophic factors. Cancer neuroscience is still in its infancy, which means that many of the interactions and mechanisms between the nervous system and cancer are not yet fully understood. Further investigation is necessary to probe the interactions of the nervous system with cancer cell subpopulations and other components of the tumor microenvironment.

Toxoplasma infection induces an aged neutrophil population in the CNS that is associated with neuronal protection

BACKGROUND

Infection with the protozoan parasite Toxoplasma gondii leads to the formation of lifelong cysts in neurons that can have devastating consequences in the immunocompromised. In the immunocompetent individual, anti-parasitic effector mechanisms and a balanced immune response characterized by pro- and anti-inflammatory cytokine production establishes an asymptomatic infection that rarely leads to neurological symptoms. Several mechanisms are known to play a role in this successful immune response in the brain including T cell production of IFNγ and IL-10 and the involvement of CNS resident cells. This limitation of clinical neuropathology during chronic infection suggests a balance between immune response and neuroprotective mechanisms that collectively prevent clinical manifestations of disease. However, how these two vital mechanisms of protection interact during chronic Toxoplasma infection remains poorly understood.

MAIN TEXT

This study demonstrates a previously undescribed connection between innate neutrophils found chronically in the brain, termed "chronic brain neutrophils" (CBNeuts), and neuroprotective mechanisms during Toxoplasma infection. Lack of CBNeuts during chronic infection, accomplished via systemic neutrophil depletion, led to enhanced infection and deleterious effects on neuronal regeneration and repair mechanisms in the brain. Phenotypic and transcriptomic analysis of CBNeuts identified them as distinct from peripheral neutrophils and revealed two main subsets of CBNeuts that display heterogeneity towards both classical effector and neuroprotective functions in an age-dependent manner. Further phenotypic profiling defined expression of the neuroprotective molecules NRG-1 andErbB4 by these cells, and the importance of this signaling pathway during chronic infection was demonstrated via NRG-1 treatment studies.

CONCLUSIONS

In conclusion, this work identifies CBNeuts as a heterogenous population geared towards both classical immune responses and neuroprotection during chronic Toxoplasma infection and provides the foundation for future mechanistic studies of these cells.

Neuro-immune crosstalk in hematopoiesis, inflammation, and repair

Innate immune cells are primary effectors during host defense and in sterile inflammation. Their production in the bone marrow is tightly regulated by growth and niche factors, and their activity at sites of inflammation is orchestrated by a network of alarmins and cytokines. Yet, recent work highlights a significant role of the peripheral nervous system in these processes. Sympathetic neural pathways play a key role in regulating blood cell homeostasis, and sensory neural pathways mediate pro- or anti-inflammatory signaling in a tissue-specific manner. Here, we review emerging evidence of the fine titration of hematopoiesis, leukocyte trafficking, and tissue repair via neuro-immune crosstalk, and how its derailment can accelerate chronic inflammation, as in atherosclerosis.

Neuroimmune crosstalk : How mental stress fuels vascular inflammation

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

Sex-specific impact of psychosocial stress on hematopoiesis and blood leukocytes

Stress exposure has been shown to modulate innate and adaptive immune responses. Indeed, stress favors myelopoiesis and monocyte generation and contributes to cardiovascular disease development. As sex hormones regulate innate and adaptive immune responses, we decided to investigate whether stress exposure leads to a different immune response in female and male mice. Our data demonstrated that psychosocial stressinduced neutrophilia in male, but not female mice. Importantly, we identified that B-cell numbers were reduced in female, but not male mice upon exposure to stress. Thus, our study revealed that the stress-induced immune alterations are sex-dependent, and this is an important feature to consider for future investigations.

Predictive models for personalized precision medical intervention in spontaneous regression stages of cervical precancerous lesions

BACKGROUND

During the prolonged period from Human Papillomavirus (HPV) infection to cervical cancer development, Low-Grade Squamous Intraepithelial Lesion (LSIL) stage provides a critical opportunity for cervical cancer prevention, giving the high potential for reversal in this stage. However, there is few research and a lack of clear guidelines on appropriate intervention strategies at this stage, underscoring the need for real-time prognostic predictions and personalized treatments to promote lesion reversal.

METHODS

We have established a prospective cohort. Since 2018, we have been collecting clinical data and pathological images of HPV-infected patients, followed by tracking the progression of their cervical lesions. In constructing our predictive models, we applied logistic regression and six machine learning models, evaluating each model's predictive performance using metrics such as the Area Under the Curve (AUC). We also employed the SHAP method for interpretative analysis of the prediction results. Additionally, the model identifies key factors influencing the progression of the lesions.

RESULTS

Model comparisons highlighted the superior performance of Random Forests (RF) and Support Vector Machines (SVM), both in clinical parameter and pathological image-based predictions. Notably, the RF model, which integrates pathological images and clinical multi-parameters, achieved the highest AUC of 0.866. Another significant finding was the substantial impact of sleep quality on the spontaneous clearance of HPV and regression of LSIL.

CONCLUSIONS

In contrast to current cervical cancer prediction models, our model's prognostic capabilities extend to the spontaneous regression stage of cervical cancer. This model aids clinicians in real-time monitoring of lesions and in developing personalized treatment or follow-up plans by assessing individual risk factors, thus fostering lesion spontaneous reversal and aiding in cervical cancer prevention and reduction.

Beta2 adrenergic receptor-mediated abnormal myelopoiesis drives neuroinflammation in aged patients with traumatic brain injury

Aged patients often suffer poorer neurological recovery than younger patients after traumatic brain injury (TBI), but the mechanisms underlying this difference remain unclear. Here, we demonstrate abnormal myelopoiesis characterized by increased neutrophil and classical monocyte output but impaired nonclassical patrolling monocyte population in aged patients with TBI as well as in an aged murine TBI model. Retrograde and anterograde nerve tracing indicated that increased adrenergic input through the central amygdaloid nucleus-bone marrow axis drives abnormal myelopoiesis after TBI in a β2-adrenergic receptor-dependent manner, which is notably enhanced in aged mice after injury. Selective blockade of β2-adrenergic receptors rebalances abnormal myelopoiesis and improves the outcomes of aged mice after TBI. We therefore demonstrate that increased β2-adrenergic input-driven abnormal myelopoiesis exacerbates post-TBI neuroinflammation in the aged, representing a mechanism underlying the poorer recovery of aged patients and that blockade of β2-adrenergic receptor is a potential approach to promote neurological recovery after TBI.

Biosafety assessments of hexafluoropropylene trimer derivative as a fluorinated cooling fluid for electronics

The Internet Data Center (IDC) is one of the most important infrastructures in the field of information technology. The cooling system for heat dissipation of IDC is indispensable due to it generates a large amount of heat during its calculation process, which may potentially harm its normal operation. Electronic fluorinated fluids have been widely used in cooling systems of IDC with stable physical and chemical properties. However, the biological toxicity of electronic fluorinated fluids has not been fully evaluated and there is a lack of unified safety standards, which may pose potential risks to the environment and human health. Here, hexafluoropropylene terpolymer (HFPT) as an example has been systematically studied, fully considering the application scenarios of data centers. Also, the emergency effects of fluorinated coolants in mammalian models from the perspectives of inhalation, skin contact, accidental entry into eyes, accidental ingestion, and chronic toxicity, are evaluated. Multiple in vivo experiments have proven that HFPT not only has stable physical and chemical properties, that can maintain the safe operation of IDC, but also has low physiological toxicity to mammals and can provide health benefits to data center staff and the assurance of surrounding environment. This study proves the good biological safety of electronic fluorinated fluids and provides a reference for environmental assessment and risk management of liquid cooling technology in IDC.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43188-024-00234-3.

Dynamic changes of complete blood cell count parameters among airport workers during the COVID-19 pandemic in Chongqing, China: A retrospective longitudinal study

Background and aims

This study aimed to examine the dynamic changes in the complete blood counts of airport staff from 2019 to 2021 and assess the impact of the coronavirus disease 2019 (COVID-19) on their overall health status during the first pandemic wave.

Materials and methods

A total of 2144 airport staff members from Chongqing Jiangbei International Airport who underwent health examinations for three consecutive years from 2019 to 2021 were recruited for this study. Venous blood samples were collected for a complete blood cell count.

Results

Changes were observed in blood routine parameters from airport staff over three consecutive years. After adjusting for age, body mass index, and systolic blood pressure, the red blood cell count decreased consecutively during the COVID-19 pandemic. Hemoglobin and basophil counts decreased significantly during COVID-19 year 1. Lymphocyte and platelet counts decreased, whereas the monocyte-to-lymphocyte ratio increased in COVID-19 year 2. However, the white blood cell count, neutrophil count, neutrophil-to-lymphocyte ratio, and eosinophil count did not change from 2019 to 2021.

Conclusion

This study showed changes in complete blood counts in frontline airport workers, especially men, during the COVID-19 pandemic. Therefore, paying more attention to the overall health conditions and immune function of airport staff engaged in intensive work is necessary.

Neurobiological basis of stress resilience

A majority of humans faced with severe stress maintain normal physiological and behavioral function, a process referred to as resilience. Such stress resilience has been modeled in laboratory animals and, over the past 15 years, has transformed our understanding of stress responses and how to approach the treatment of human stress disorders such as depression, post-traumatic stress disorder (PTSD), and anxiety disorders. Work in rodents has demonstrated that resilience to chronic stress is an active process that involves much more than simply avoiding the deleterious effects of the stress. Rather, resilience is mediated largely by the induction of adaptations that are associated uniquely with resilience. Such mechanisms of natural resilience in rodents are being characterized at the molecular, cellular, and circuit levels, with an increasing number being validated in human investigations. Such discoveries raise the novel possibility that treatments for human stress disorders, in addition to being geared toward reversing the damaging effects of stress, can also be based on inducing mechanisms of natural resilience in individuals who are inherently more susceptible. This review provides a progress report on this evolving field.

Data-Driven Analysis Reveals Cortical Infarction Patterns Correlated With Inflammation and Prognosis: A Retrospective, Multicenter Cohort Study

BACKGROUND

We aim to identify the distinct lesion patterns and regions associated with functional outcome and inflammation in patients with acute ischemic stroke, and investigate whether the association between lesion patterns and functional outcome was mediated by inflammation.

METHODS AND RESULTS

We performed nonnegative matrix factorization to derived low-dimensional lesion patterns (atoms), and Bayesian linear regression models were applied to explore the associations of lesion patterns with inflammatory factors including high-sensitivity C-reactive protein and interleukin-6, as well as functional outcome (defined as modified Rankin Scale score at 3 months). The difference distribution mean and 95% highest probability density interval (HPDI) were calculated. Mediation analysis was used to examine the mediating effects of inflammation on the relationships between lesion patterns and functional outcome. Seven lesion patterns were derived from 5914 patients with acute ischemic stroke. Lesion patterns distributed in the cortical regions were associated with inflammatory response, including atom 1 (interleukin-6: mean, 0.113 [95% HPDI, 0.073-0.162]; high-sensitivity C-reactive protein: mean, 0.082 [95% HPDI, 0.038-0.123]) and atom 4 (interleukin-6: mean, 0.113 [95% HPDI, 0.071-0.167]; high-sensitivity C-reactive protein: mean, 0.108 [95% HPDI, 0.058-0.165]). These lesion patterns were also significantly associated with functional outcome (atom 1: mean, 1.958 [95% HPDI, 1.538-2.383]; atom 4: mean, 2.245 [95% HPDI, 1.773-2.741]). Mediation analysis suggested that interleukin-6 explained 15.34% and 7.47% in the association of atom 1 and atom 4 with functional outcome, respectively.

CONCLUSIONS

Certain lesion patterns that are associated with both inflammation and functional outcome of acute ischemic stroke, especially cortical infarction, may play a role in functional outcome through modulating inflammatory reactions.

Adrenal gland macrophages regulate glucocorticoid production through Trem2 and TGF-β

Glucocorticoid synthesis by adrenal glands (AGs) is regulated by the hypothalamic-pituitary-adrenal axis to facilitate stress responses when the host is exposed to stimuli. Recent studies implicate macrophages as potential steroidogenic regulators, but the molecular mechanisms by which AG macrophages exert such influence remain unclear. In this study, we investigated the role of AG macrophages in response to cold challenge or atherosclerotic inflammation as physiologic models of acute or chronic stress. Using single-cell RNA sequencing, we observed dynamic AG macrophage polarization toward classical activation and lipid-associated phenotypes following acute or chronic stimulation. Among transcriptional alterations induced in macrophages, triggering receptor expressed on myeloid cells 2 (Trem2) was highlighted because of its upregulation following stress. Conditional deletion of macrophage Trem2 revealed a protective role in stress responses. Mechanistically, Trem2 deletion led to increased AG macrophage death, abolished the TGF-β-producing capacity of AG macrophages, and resulted in enhanced glucocorticoid production. In addition, enhanced glucocorticoid production was replicated by blockade of TGF-β signaling. Together, these observations suggest that AG macrophages restrict steroidogenesis through Trem2 and TGF-β, which opens potential avenues for immunotherapeutic interventions to resolve stress-related disorders.

Plasma proteomics in the UK Biobank reveals youthful brains and immune systems promote healthspan and longevity

Organ-derived plasma protein signatures derived from aptamer protein arrays track organ-specific aging, disease, and mortality in humans, but the robustness and clinical utility of these models and their biological underpinnings remain unknown. Here, we estimate biological age of 11 organs from 44,526 individuals in the UK Biobank using an antibody-based proteomics platform to model disease and mortality risk. Organ age estimates are associated with future onset of heart failure (heart age HR=1.83), chronic obstructive pulmonary disease (lung age HR=1.39), type II diabetes (kidney age HR=1.58), and Alzheimer's disease (brain age HR=1.81) and sensitive to lifestyle factors such as smoking and exercise, hormone replacement therapy, or supplements. Remarkably, the accrual of aged organs progressively increases mortality risk while a youthful brain and immune system are uniquely associated with disease-free longevity. These findings support the use of plasma proteins for monitoring organ health and the efficacy of drugs targeting organ aging disease.

Systemic and local regulation of hematopoietic homeostasis in health and disease

Hematopoietic stem cells (HSCs) generate all blood cell lineages responsible for tissue oxygenation, life-long hematopoietic homeostasis and immune protection. In adulthood, HSCs primarily reside in the bone marrow (BM) microenvironment, consisting of diverse cell types that constitute the stem cell 'niche'. The adaptability of the hematopoietic system is required to respond to the needs of the host, whether to maintain normal physiology or during periods of physical, psychosocial or environmental stress. Hematopoietic homeostasis is achieved by intricate coordination of systemic and local factors that orchestrate the function of HSCs throughout life. However, homeostasis is not a static process; it modulates HSC and progenitor activity in response to circadian rhythms coordinated by the central and peripheral nervous systems, inflammatory cues, metabolites and pathologic conditions. Here, we review local and systemic factors that impact hematopoiesis, focusing on the implications of aging, stress and cardiovascular disease.