Search Results (108)

 Modern biomedicine frequently contextualizes disease around isolated molecular or organ-specific mechanisms, but numerous chronic diseases, including Alzheimer’s disease, multiple sclerosis, depression, diabetes, and sepsis, share common trajectories of systemic destabilization. An increasing body of evidence indicates that health is not a property of single organs but the emergent property of interdependent feedback networks linking the microbiome, endocannabinoidome, neuroimmune system, and metabolic regulators. We propose the Endocannabinoid–Microbiota–Neuroimmune Super-System (EMN-S) as an evolutionarily conserved conceptual model that describes how these fields of influence reciprocally interact through feedback control. The microbial communities constituting the EMN-S encode environmental and dietary inputs, endocannabinoid signaling serves as an integrative regulator that synchronizes neural and immune activity, and neuroimmune circuits effectuate adaptive behaviors that alter microbiotal and lipid ecosystems. This review formalizes the EMN-S, contending that it is a unitary and cohesive model of physiological resilience, as well as offering a framework for precision feedback therapeutics. We describe how three mechanisms—encoder drift, integrator detuning, and executor overutilization—convert stabilizing negative feedback into runaway feedback cascades that underlie chronic, recurrent, and multisystemic disease. We then specify the EMN-S signature—integrated microbiome, lipidomic, and immune readouts—as an early indicator of resilience collapse and prospective preclinical state. Finally, we recapitulate the potential of AI-driven digital twins to illuminate feedback collapse, predict tipping points, and direct closed-loop intervention and treatments to restore dynamic equilibrium. By anchoring complexity in concrete and measurable feedback principles, the EMN-S shifts focus to investigate pathophysiology as opposed to reductionist lesion models of systemic derangements and embraces a systemic, empirically testable theory of stability.  Full article

The enteric nervous system (ENS), frequently referred to as the “second brain,” is integral to maintaining gastrointestinal and systemic homeostasis. The structural and functional homeostasis of the ENS is crucial for both local intestinal processes (digestion, immunity) and systemic physiological equilibrium via the gut–brain axis, directly influencing overall health and disease. In recent years, dietary substances have attracted increasing scholarly attention for their potential to modulate the ENS, attributed to their safety and accessibility. This review commences with a systematic exploration of the anatomical structure of the ENS, including the myenteric and submucosal plexuses, its cellular constituents such as enteric neurons and enteric glial cells, and its core physiological functions, encompassing the regulation of gastrointestinal motility, the secretion–absorption balance, and the maintenance of immune homeostasis. Subsequently, it delineates the classification, distribution, and properties of essential dietary components, encompassing polyphenols, short-chain fatty acids, amino acids and their derivatives, as well as prebiotics and probiotics. Additionally, it examines the mechanisms through which these substances modulate the physiological functions of the ENS, including the regulation of intestinal motility, support for neuronal survival and network integrity, and the maintenance of neuro-immune homeostasis. The review concludes by highlighting current limitations—including reliance on rodent models, unclear human ENS mechanisms, and imprecise interventions—and proposes future directions focused on precision medicine, clinical translation, and advanced tools like single-cell sequencing and targeted delivery systems. Full article

Dry eye disease (DED) is increasingly recognized as a condition driven by immune dysregulation at the ocular surface (OS). Chronic inflammation, mediated by aberrant activation of both innate and adaptive immune pathways, underlies disease progression and symptom persistence. Neuroimmune interactions further amplify OS inflammation, contributing to epithelial damage and impaired homeostatic regulation. This review summarizes current literature on the immunopathogenesis of DED, highlighting the complex interplay of molecular mechanisms of innate and adaptive immune activation, neuroimmune-mediated inflammation, and emerging molecular and cellular biomarkers. In addition, we examine existing and emerging therapeutic strategies that target these immune-molecular pathways, including precision immunomodulatory approaches, to inform future management of DED. By integrating mechanistic insights with clinical findings, this review aims to provide a comprehensive overview of the molecular mechanisms underlying the dysregulated immune response associated with DED. Full article

Background/Objectives: The gut microbiome is increasingly recognized as a key modulator of central nervous system function through the gut–brain axis. Dysbiosis has been associated with neuropsychiatric disorders such as depression, anxiety, impulsivity, cognitive decline, and addiction. This review aims to synthesize mechanistic insights and therapeutic perspectives on how gut microbiota influence mood regulation, decision-making, and cognitive processes. Methods: A comprehensive narrative review was conducted using peer-reviewed articles retrieved from PubMed, Scopus, and Web of Science up to August 2025. Studies were included if they explored microbiota-related effects on behavior, mood, cognition, or decision-making using human or animal models. Emphasis was placed on molecular mechanisms, microbiome-targeted therapies, and multi-omics approaches. Results: Evidence indicates that gut microbiota modulate neurochemical pathways involving serotonin, dopamine, GABA, and glutamate, as well as immune and endocrine axes. Microbial imbalance contributes to low-grade systemic inflammation, impaired neuroplasticity, and altered stress responses, all of which are linked to mood and cognitive disturbances. Specific microbial taxa, dietary patterns, and interventions such as probiotics, prebiotics, psychobiotics, and fecal microbiota transplantation (FMT) have shown promise in modulating these outcomes. The review highlights methodological advances including germ-free models, metagenomic profiling, and neuroimaging studies that clarify causal pathways. Conclusions: Gut microbiota play a foundational role in shaping emotional and cognitive functions through complex neuroimmune and neuroendocrine mechanisms. Microbiome-based interventions represent a promising frontier in neuropsychiatric care, although further translational research is needed to define optimal therapeutic strategies and address individual variability. Full article

Sepsis is a life-threatening syndrome marked by a dysregulated host response to infection, resulting in systemic inflammation, organ dysfunction, and high mortality globally. Despite advancements in supportive care, effective immunomodulatory therapies remain elusive, necessitating exploration of novel biological pathways and subsequent therapeutic development. The endocannabinoid system (ECS), which regulates immune function and homeostasis, has emerged as a key modulator of immunological and metabolic pathways central to sepsis pathophysiology. The ECS mediates its effects through endogenous ligands, G-protein-coupled cannabinoid receptors (CB1 and CB1), and regulatory enzymes that control its synthesis and degradation. Following PRISMA-ScR guidelines, this scoping review synthesizes current evidence on the mechanistic roles of ECS components in experimental and clinical models of sepsis, identifies knowledge gaps, and delineates future areas of work. A comprehensive literature search across multiple databases without restrictions on date or publication type was executed to ensure broad coverage of original studies investigating ECS mechanisms and their intersection with sepsis and septic shock. Across 53 studies, CB2 receptor activation was consistently associated with anti-inflammatory process, organ-protective outcomes, and increased survival rates against septic challenges in preclinical rodent models. CB1 receptor activation trends, however, showed context dependent outcomes. Central antagonism improved hemodynamics and survival rate, but peripheral effects varied with cell type and timing. Non-canonical ECS components (TRPV1, GPR55, PPAR-α, FAAH, MAGL) also contributed to neuroimmune and metabolic regulation. Limited clinical data linked ECS lipid profiles and gene expression with sepsis severity and outcomes. Collectively, ECS modulation, particularly CB2 agonism, TRPV1 activation, and FAAH/MAGL inhibition, shows promise in mitigating sepsis-induced inflammation and organ dysfunction. However, complex, context-dependent effects, especially involving CB1, highlight the need for precision-targeted therapeutic approaches. Further preclinical research is needed to expand generalizable trends to allow translational research to refine ECS-based interventions for sepsis management. Full article

Heat stress typically suppresses systemic immunity in fish; however, its effects on the brain—an organ traditionally regarded as immune-privileged—remain unclear. In this study, we performed histopathological examination and RNA-seq analysis on the brains of juvenile largemouth bass (Micropterus salmoides) exposed to control (28 °C) and elevated (36.5 °C) water temperatures for 8 weeks. Histological analysis revealed distinct cytoarchitectural and pathological changes in specific brain regions. RNA-seq analysis identified a total of 1240 differentially expressed genes, with 22 heat shock protein genes notably showing significant up-regulation. The immune system-associated genes emerged as the most prominently affected category. Gene set enrichment analysis (GSEA) based on Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway annotations revealed that up-regulated genes were enriched in immunity-related pathways, including the NOD-like receptor (NLR) signaling pathway, Toll-like receptor (TLR) signaling pathway, and cytosolic DNA-sensing pathway. Additionally, the levels of apoptosis and necroptosis were moderately increased. GSEA based on Gene Ontology (GO) terms indicated that down-regulated genes were primarily associated with cell division. Protein–protein interaction (PPI) and clustering analysis identified 41 core genes in the top three clusters, encompassing those related to nuclear chromosome segregation, ribosome biogenesis, and stress response. The inhibition of genes involved in nuclear chromosome segregation may disrupt cellular homeostasis by significantly impairing microtubule dynamics. In contrast, genes associated with ribosome biogenesis and stress response were up-regulated, which could counteract the adverse effects caused by long-term heat stress. We propose that brain-specific immune activation, particularly via the NLR and TLR signaling pathways, acts as a compensatory strategy to counterbalance heat-induced cell death, thereby revealing a novel neuro-immune adaptation axis. Full article

Post-traumatic stress disorder (PTSD) is frequently comorbid with persistent depressive disorder (dysthymia), indicating shared neurobiological pathways that influence stress modulation, emotional regulation, and neurohormonal adaptation. This study examines the roles of serum biomarkers—small ubiquitin-like modifier 1 (SUMO1), malondialdehyde (MDA), fractalkine (CX3CL1), and ubiquitin C-terminal hydrolase L1 (UCHL1)—involved in oxidative stress management, neuroimmune regulation, and neuronal proteostasis. In this cross-sectional analysis, biomarker expression was assessed in 92 male trauma-exposed participants aged 19–50 years, divided into three groups: PTSD duration ≤ 5 years (n = 33, median age 34.0 years [IQR 31.0–41.0]), PTSD duration > 5 years (n = 31, median age 36.0 years [IQR 29.5–41.0]), and controls without current or past PTSD (n = 28, median age 33.5 years [IQR 24.3–41.5]). Participants were stratified into younger (19–34 years) and older (35–50 years) cohorts to account for age-related neurobiological variability. Dysthymic symptomatology was evaluated using the Cornell Dysthymia Rating Scale (CDRS), focusing on chronic subthreshold depressive features. Results indicated a significant association between PTSD and elevated dysthymic symptom burden (p < 0.001), with both PTSD subgroups demonstrating mild to moderate CDRS severity compared to euthymic controls. Biomarker analysis revealed phase-dependent alterations: SUMO1 levels were significantly elevated in the ≤5 years PTSD group compared to controls (p = 0.002), suggesting early compensatory neuroprotection, whereas UCHL1 was markedly increased in the >5 years PTSD group (p = 0.015), which is indicative of chronic neuronal damage and proteostatic disruption. No significant differences were observed in MDA or CX3CL1 across groups (p > 0.05). These findings highlight PTSD’s contribution to sustained affective dysregulation, potentially mediated by temporal shifts in oxidative stress and protein homeostasis markers. Clinically, this supports the utility of biomarker profiling for risk stratification, early intervention, and personalized therapeutic strategies, such as targeted modulation of SUMOylation or UCHL1 activity, to enhance neuroresilience and mitigate progression to severe mood disorders. Full article

Autoimmune diseases are chronic inflammatory conditions characterized by the breakdown of immune tolerance to self-antigens. While genetic and environmental factors play key roles, growing evidence highlights chronic stress as a significant contributor to immune dysregulation through its impact on the hypothalamic–pituitary–adrenal (HPA) axis. The HPA axis, primarily via cortisol secretion, serves as the major neuroendocrine mediator of stress responses, influencing both immune regulation and systemic homeostasis. This review synthesizes current literature on HPA axis physiology, the mechanisms of cortisol signaling, and the maladaptive effects of chronic stress. Emphasis is placed on clinical and experimental findings linking HPA dysfunction to immune imbalance and autoimmunity, as well as organ-specific consequences across neuroimmune, endocrine, cardiovascular, gastrointestinal, integumentary, and musculoskeletal systems. Chronic stress leads to impaired HPA axis feedback, glucocorticoid receptor resistance, and paradoxical cortisol dysregulation, fostering a pro-inflammatory state. This dysregulation promotes cytokine imbalance, weakens protective immune mechanisms, and shifts the immune response toward autoimmunity. Evidence from both human and animal studies associates persistent HPA dysfunction with diseases such as systemic lupus erythematosus, rheumatoid arthritis, and multiple sclerosis. HPA axis dysregulation under chronic stress constitutes a critical mechanistic link between psychological stress and autoimmune disease. Understanding these pathways provides opportunities for therapeutic interventions, including stress management, lifestyle modification, and neuroendocrine-targeted treatments. Future research should focus on multi-omics and longitudinal approaches to clarify the reversibility of HPA alterations and identify resilience factors. Full article

Background/Objectives: Polygonatum sibiricum (PS), possessing both medicinal and edible dual functions, boasts a long history of application in Chinese traditional practices. As a component of its effectiveness, Polygonatum sibiricum polysaccharides (PSPs) have been reported to exert neuroprotective effects. However, the protective effects of PS on the cognitive deficits induced by simulated weightlessness remain unclear. This study evaluated the therapeutic potential of PSPs to counteract the cognitive deficits induced by simulated weightlessness using the Hindlimb Unloading (HU) method. Methods: Mice were subjected to HU to establish cognitive impairment, and PSP was administered for four weeks. The Morris water maze test (MWMT) and passive avoidance test (PAT) were used to evaluate the cognitive abilities of mice, followed by an analysis of molecular mechanisms. Results: PSP treatment increased learning and memory in mice. PSP treatment partially restored gut microbial diversity and composition towards beneficial taxa, including Lactobacillus and Firmicutes, while inhibiting proinflammatory genera, including Alistipes and Proteus. At the same time, PSP upregulated Claudin-5 and Zonula Occludens-1 (ZO-1) levels in the colon, suggesting improved intestinal barrier integrity, and decreased neuroinflammatory response by inhibiting NLRP3 inflammasome activation and NF-κB phosphorylation in the hippocampus. It also modulated neurotransmitter homeostasis along the microbiota–gut–brain (MGB) axis by increasing the levels of gamma-aminobutyric acid (GABA) and serotonin (5-HT) while reducing the levels of excitotoxic metabolites, including Glutamate (Glu) and 3-hydroxykynurenine (3-HK). Conclusions: These results indicate that PSP may have beneficial effects on HU-induced cognitive impairment by regulating gut microbiota, enhancing barrier function, suppressing neuroimmune signaling, and restoring neurotransmitter balance. Full article

Astrocytes are the most common type of glial cell in the central nervous system (CNS). They have many different functions that go beyond just supporting other cells. Astrocytes were once thought of as passive parts of the CNS. However, now they are known to be active regulators of homeostasis and active participants in both neurodevelopmental and neurodegenerative processes. This article looks at the both sides of astrocytic function: how they safeguard synaptic integrity, ion and neurotransmitter balance, and blood-brain barrier (BBB) stability, as well as how astrocytes can become activated and participate in the immune response by releasing cytokines, upregulating interferons, and modulating the blood–brain barrier and inflammation disease condition. Astrocytes affect and influence neuronal function through the tripartite synapse, gliotransmission, and the glymphatic system. When someone is suffering from neurological disorders, reactive astrocytes become activated after being triggered by factors such as pro-inflammatory cytokines, chemokines, and inflammatory mediators, these reactive astrocytes, which have higher levels of glial fibrillary acidic protein (GFAP), can cause neuroinflammation, scar formation, and the loss of neurons. This review describes how astrocytes are involved in important CNS illnesses such as Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, amyotrophic lateral sclerosis, and ischemia. It also emphasizes how these cells can change from neuroprotective to neurotoxic states depending on the situation. Researchers look at important biochemical pathways, such as those involving toll-like receptors, GLP-1 receptors, and TREM2, to see if they can change how astrocytes respond. Astrocyte-derived substances, including BDNF, GDNF, and IL-10, are also essential for protecting and repairing neurons. Astrocytes interact with other CNS cells, especially microglia and endothelial cells, thereby altering the neuroimmune environment. Learning about the molecular processes that control astrocytic plasticity opens up new ways to treat glial dysfunction. This review focuses on the importance of astrocytes in the normal and abnormal functioning of the CNS, which has a significant impact on the development of neurotherapeutics that focus on glia. Full article

Background: The human gut microbiome—a diverse ecosystem of trillions of microorganisms—plays an essential role in metabolic, immune, and neurological regulation. However, modern lifestyle factors such as antibiotic overuse, cesarean delivery, reduced breastfeeding, processed and high-sodium diets, alcohol intake, smoking, and exposure to environmental toxins (e.g., glyphosate) significantly reduce microbial diversity. Loss of keystone species like Bifidobacterium infantis (B. infantis) and Lactobacillus reuteri (L. reuteri) contributes to gut dysbiosis, which has been implicated in chronic metabolic, autoimmune, cardiovascular, and neurodegenerative conditions. Materials and Methods: This Qualitative Systematic Review (QualSR) synthesized data from over 547 studies involving human participants and standardized microbiome analysis techniques, including 16S rRNA sequencing and metagenomics. Studies were reviewed for microbial composition, immune and metabolic biomarkers, and clinical outcomes related to microbiome restoration strategies. Results: Multiple cohort studies have consistently reported a 40–60% reduction in microbial diversity among Western populations compared to traditional societies, particularly affecting short-chain fatty acid (SCFA)-producing bacteria. Supplementation with B. infantis is associated with a significant reduction in systemic inflammation—including a 50% decrease in C-reactive protein (CRP) and reduced tumor necrosis factor-alpha (TNF-α) levels—alongside increases in regulatory T cells and anti-inflammatory cytokines interleukin-10 (IL-10) and transforming growth factor-beta 1 (TGF-β1). L. reuteri demonstrates immunomodulatory and neurobehavioral benefits in preclinical models, while both probiotics enhance epithelial barrier integrity in a strain- and context-specific manner. In murine colitis, B. infantis increases ZO-1 expression by ~35%, and L. reuteri improves occludin and claudin-1 localization, suggesting that keystone restoration strengthens barrier function through tight-junction modulation. Conclusions: Together, these findings support keystone species restoration with B. infantis and L. reuteri as a promising adjunctive strategy to reduce systemic inflammation, reinforce gut barrier integrity, and modulate gut–brain axis (GBA) signaling, indicating translational potential in metabolic and neuroimmune disorders. Future research should emphasize personalized microbiome profiling, long-term outcomes, and transgenerational effects of early-life microbial disruption. Full article

Leprosy remains a significant public health issue, particularly due to its neuropathic consequences, which affect sensory, motor, and autonomic functions, leading to severe disabilities. HIV/AIDS, another major public health concern, overlaps geographically with leprosy and is also associated with peripheral neuropathies, complicating the management of co-infected patients. Understanding how Nerve Growth Factor (NGF) is regulated in leprosy and HIV-leprosy co-infection may contribute to immunomodulatory treatments and neuroimmune response control. A cross-sectional study evaluated NGF tissue expression using immunohistochemistry in 47 HIV/leprosy co-infected patients and 61 leprosy-only patients. The co-infected group had a higher incidence of neuritis (40.4%) and a prevalence of exclusively reversal reactions. However, the occurrence of neuritis was not associated with higher expression of NGF in the tissue. Leprosy reactions were more prevalent in non-co-infected patients with multibacillary forms (50%). Multibacillary forms in both groups of patients showed higher cellular expression of NGF, with a greater tendency for higher NGF expression in non-co-infected multibacillary patients (p = 0.0021), suggesting impairment in the immune response involved in the tissue expression of neurotrophins in the co-infected group. Overall, co-infection with HIV did not influence the increase in NGF in the lesions of leprosy patients compared with patients with leprosy alone. Full article

Inter-organ communication plays a vital role in the pathogenesis of neurodegenerative diseases (ND), including Alzheimer’s disease (AD), Parkinson’s disease (PD), and Amyotrophic Lateral Sclerosis (ALS). Emerging research highlights the involvement of the gut–brain axis, immune system, and peripheral metabolic systems in modulating neuroinflammation, protein misfolding, and neuronal dysfunction by releasing cytokines, adipokines, growth factors, and other soluble factors, which in turn affect neuronal health and systemic inflammation. This review explores the complex bidirectional interactions between the brain and peripheral organs, including the gut, adipose tissue, liver, muscle, bone and immune system. Notably, the gut microbiome’s role in neurodegenerative diseases through the gut–brain axis, the impact of adipose tissue in inflammation and metabolic regulation, and the muscle–brain axis with its neuroprotective myokines are also discussed. Additionally, we examine the neuro-immune axis, which mediates inflammatory responses and exacerbates neurodegeneration, and liver–brain axis that is implicated in regulating neuroinflammation and promoting disease progression. Dysregulation of inter-organ pathways contributes to the systemic manifestations of neurodegenerative diseases, offering insights into both potential biomarkers and therapeutic targets, and, in turn, promising strategies for preventing, diagnosing, and treating neurodegenerative diseases. Full article

Opioid-use disorder (OUD) poses a growing global health crisis, with chronic opioid exposure linked not only to addiction but also to enduring neurological impairments. While traditional research has focused primarily on neuronal alterations, emerging evidence underscores the pivotal role of astrocytes, abundant glial cells in the central nervous system, and their secreted extracellular vesicles (EVs) in opioid-mediated neuropathology. This review delineates the mechanistic roles of astrocytes and astrocyte-derived EVs (ADEVs) across a spectrum of opioids, including morphine, heroin, fentanyl, codeine, tramadol, buprenorphine, and methadone. Opioids disrupt astrocytic homeostasis by impairing glutamate regulation, altering the redox balance, and activating pro-inflammatory signaling pathways. In response, astrocytes release EVs enriched with neurotoxic cargo, including amyloidogenic proteins, cytokines, microRNAs, and long non-coding RNAs, that propagate neuroinflammation, compromise blood–brain barrier (BBB) integrity, and exacerbate synaptic dysfunction. Preclinical models and in vitro studies reveal drug-specific astrocytic responses and ADEV profiles, implicating these vesicles in modulating microglial function, neuroimmune signaling, and neuronal viability. Notably, morphine-induced ADEVs promote amyloidosis and inflammatory signaling, while heroin and fentanyl affect glutamatergic and inflammasome pathways. Even opioids used in therapy, such as buprenorphine and methadone, alter astrocyte morphology and EV cargo, particularly during neurodevelopment. Collectively, these findings advance a neuro-glial paradigm for understanding opioid-induced brain injury and highlight ADEVs as both biomarkers and mediators of neuropathology. Targeting astrocyte-EV signaling pathways represents a promising therapeutic avenue to mitigate long-term neurological consequences of opioid exposure and improve outcomes in OUD. Full article

Rheumatoid arthritis (RA) is a systemic autoimmune disease that, beyond joint destruction, contributes to neuropsychiatric symptoms such as depression, anxiety, and cognitive impairment. These symptoms are often underrecognized despite their major impact on quality of life. Accumulating evidence suggests that pro-inflammatory cytokines, particularly tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6), play a key role in this neuroimmune interface. This narrative review examined 16 clinical studies evaluating the effects of biologic therapies targeting TNF-α and IL-6 on mental health outcomes in RA. The total study population comprised 9939 patients, including 2467 treated with TNF-α inhibitors and 7472 with IL-6 or IL-6 receptor inhibitors. TNF-α inhibitors were associated with improved depressive symptoms and emotional well-being. IL-6 inhibitors demonstrated similar psychiatric benefits, particularly in patients with elevated IL-6 levels. The findings highlight that biological therapies in RA may influence not only physical symptoms but also mental health, likely through modulation of neuroimmune pathways including blood–brain barrier permeability, microglial activation, and HPA axis regulation. Future research is needed to clarify these effects in populations stratified by psychiatric comorbidity and inflammatory biomarkers. Clinical implications: Incorporating psychiatric symptom screening and considering neuroinflammatory profiles may help guide the selection of biologic therapy in RA, particularly in patients with comorbid depression or fatigue. Full article