Inflammation From Peripheral Organs to the Brain: How Does Systemic Inflammation Cause Neuroinflammation?

Role of metabolic dysfunction and inflammation along the liver-brain axis in animal models with obesity-induced neurodegeneration

The interaction between metabolic dysfunction and inflammation is central to the development of neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. Obesity-related conditions like type 2 diabetes and non-alcoholic fatty liver disease exacerbate this relationship. Peripheral lipid accumulation, particularly in the liver, initiates a cascade of inflammatory processes that extend to the brain, influencing critical metabolic regulatory regions. Ceramide and palmitate, key lipid components, along with lipid transporters lipocalin-2 and apolipoprotein E, contribute to neuroinflammation by disrupting blood-brain barrier integrity and promoting gliosis. Peripheral insulin resistance further exacerbates brain insulin resistance and neuroinflammation. Preclinical interventions targeting peripheral lipid metabolism and insulin signaling pathways have shown promise in reducing neuroinflammation in animal models. However, translating these findings to clinical practice requires further investigation into human subjects. In conclusion, metabolic dysfunction, peripheral inflammation, and insulin resistance are integral to neuroinflammation and neurodegeneration. Understanding these complex mechanisms holds potential for identifying novel therapeutic targets and improving outcomes for neurodegenerative diseases.

Associations between inflammation and striatal dopamine D2-receptor availability in aging

BACKGROUND

Normal brain aging is associated with dopamine decline, which has been linked to age-related cognitive decline. Factors underlying individual differences in dopamine integrity at older ages remain, however, unclear. Here we aimed at investigating: (i) whether inflammation is associated with levels and 5-year changes of in vivo dopamine D2-receptor (DRD2) availability, (ii) if DRD2-inflammation associations differ between men and women, and (iii) whether inflammation and cerebral small-vessel disease (white-matter lesions) serve as two independent predictors of DRD2 availability.

METHODS

Analyses were performed in a sample of healthy adults > 60 years assessed at two measurement occasions separated by 5 years. At both occasions, DRD2 availability was estimated by 11C-raclopride PET, and white-matter lesions by MRI. Inflammation was assessed by two C-reactive protein-associated DNA methylation scores at study baseline.

RESULTS

Individuals with higher DNA methylation scores at baseline showed reduced striatal DRD2 availability. An interaction was found between DNA methylation scores and sex in relation to striatal DRD2 availability, such that associations were found in men but not in women. DNA methylation scores at study entrance were not significantly associated with 5-year striatal DRD2 decline rates. No significant association was found between DNA methylation scores and white-matter lesions, but higher scores as well as higher lesion burden were independently associated with reduced striatal DRD2 availability in men.

CONCLUSIONS

These findings suggest negative associations between one proxy of inflammation and DRD2 availability in older adults, selectively for men who had higher DNA methylation scores. Future studies should investigate other inflammatory markers in relation to dopamine integrity.

Blood levels of cytokines highlight the role of inflammation in Alzheimer's disease

Inflammation and angiogenesis have been defined as potential mechanisms associated with clinical progression from a cognitively normal state to Alzheimer's disease (AD). In this observational case-control study, we aimed to determine plasma levels of cytokines as indicators of inflammation involved in cognitive decline. We measured 30 plasma proteins in 49 controls (CTL), 36 individuals with mild cognitive impairment (MCI) and 52 patients diagnosed with probable AD. After applying strict filters for quantification limits, only 13 analytes were included in the analysis. Kruskal-Wallis tests showed significant differences between diagnostic groups for nine cytokines (IL-16, IL-7, VEGF, IL-8, eotaxin, MCP-1, MCP-4, MDC and TARC). Non-parametric MANCOVA showed that sex and diagnosis affected cytokine levels in the blood. To determine the sensitivity and specificity of the markers, we performed receiver operating characteristic (ROC) curve analysis. Only those analytes that showed an area under the curve (AUC) ≥ 0.70 were included in the multivariate logistic regression models to better understand the contribution of cytokines to clinical status. Three models: 1) CTL vs. AD; 2) CTL vs. MCI, and 3) MCI vs. AD were developed, with sex and age as covariates. In each model, two cytokines remained significantly different (model 1: IL-16 and MDC; model 2: eotaxin and MDC and model 3: IL-7 and VEGF). Taken together, this report identifies a set of plasma markers of inflammation and strengthens the role of glial biology in different clinical stages of AD.

Mushrooms, Microdosing, and Mental Illness: The Effect of Psilocybin on Neurotransmitters, Neuroinflammation, and Neuroplasticity

The incidence of mental health disorders is increasing worldwide. While there are multiple factors contributing to this problem, neuroinflammation underlies a significant subset of psychiatric conditions, particularly major depressive and anxiety disorders. Anti-inflammatory interventions have demonstrated benefit in these conditions. Psilocin, the active ingredient of mushrooms in the Psilocybe genus, is both a potent serotonin agonist and anti-inflammatory agent, increases neuroplasticity, and decreases overactivity in the default mode network. Studies using hallucinogenic doses of psilocin under the supervision of a therapist/guide have consistently demonstrated benefits to individuals with depression and end-of-life anxiety. Microdosing psilocybin in sub-hallucinogenic doses has also demonstrated benefit in mood disorders, and may offer a safe, less expensive, and more available alternative to full doses of psilocybin for mood disorders, as well as for other medical conditions in which inflammation is the principal pathophysiology.

The immunological perspective of major depressive disorder: unveiling the interactions between central and peripheral immune mechanisms

Major depressive disorder is a prevalent mental disorder, yet its pathogenesis remains poorly understood. Accumulating evidence implicates dysregulated immune mechanisms as key contributors to depressive disorders. This review elucidates the complex interplay between peripheral and central immune components underlying depressive disorder pathology. Peripherally, systemic inflammation, gut immune dysregulation, and immune dysfunction in organs including gut, liver, spleen and adipose tissue influence brain function through neural and molecular pathways. Within the central nervous system, aberrant microglial and astrocytes activation, cytokine imbalances, and compromised blood-brain barrier integrity propagate neuroinflammation, disrupting neurotransmission, impairing neuroplasticity, and promoting neuronal injury. The crosstalk between peripheral and central immunity creates a vicious cycle exacerbating depressive neuropathology. Unraveling these multifaceted immune-mediated mechanisms provides insights into major depressive disorder's pathogenic basis and potential biomarkers and targets. Modulating both peripheral and central immune responses represent a promising multidimensional therapeutic strategy.

Concussion and the Autonomic, Immune, and Endocrine Systems: An Introduction to the Field and a Treatment Framework for Persisting Symptoms

A significant proportion of patients who sustain a concussion/mild traumatic brain injury endorse persisting, lingering symptoms. The symptoms associated with concussion are nonspecific, and many other medical conditions present with similar symptoms. Medical conditions that overlap symptomatically with concussion include anxiety, depression, insomnia, chronic pain, chronic fatigue, fibromyalgia, and cervical strain injuries. One of the factors that may account for these similarities is that these conditions all present with disturbances in the optimal functioning of the autonomic nervous system and its intricate interactions with the endocrine system and immune system-the three primary regulatory systems in the body. When clinicians are working with patients presenting with persisting symptoms after concussion, evidence-based treatment options drawn from the literature are limited. We present a framework for the assessment and treatment of persisting symptoms following concussion based on the available evidence (treatment trials), neuroanatomical principles (research into the physiology of concussion), and clinical judgment. We review the research supporting the premise that behavioral interventions designed to stabilize and optimize regulatory systems in the body following injury have the potential to reduce symptoms and improve functioning in patients. Foundational concussion rehabilitation strategies in the areas of sleep stabilization, fatigue management, physical exercise, nutrition, relaxation protocols, and behavioral activation are outlined along with practical strategies for implementing intervention modules with patients.

From Gut to Brain: The Impact of Short-Chain Fatty Acids on Brain Cancer

The primary source of short-chain fatty acids (SCFAs), now recognized as critical mediators of host health, particularly in the context of neurobiology and cancer development, is the gut microbiota's fermentation of dietary fibers. Recent research highlights the complex influence of SCFAs, such as acetate, propionate, and butyrate, on brain cancer progression. These SCFAs impact immune modulation and the tumor microenvironment, particularly in brain tumors like glioma. They play a critical role in regulating cellular processes, including apoptosis, cell differentiation, and inflammation. Moreover, studies have linked SCFAs to maintaining the integrity of the blood-brain barrier (BBB), suggesting a protective role in preventing tumor infiltration and enhancing anti-tumor immunity. As our understanding of the gut-brain axis deepens, it becomes increasingly important to investigate SCFAs' therapeutic potential in brain cancer management. Looking into how SCFAs affect brain tumor cells and the environment around them could lead to new ways to prevent and treat these diseases, which could lead to better outcomes for people who are dealing with these challenging cancers.

Critical Review of the Cross-Links Between Dietary Components, the Gut Microbiome, and Depression

The complex relationship between diet, the gut microbiota, and mental health, particularly depression, has become a focal point of contemporary research. This critical review examines how specific dietary components, such as fiber, proteins, fats, vitamins, minerals, and bioactive compounds, shape the gut microbiome and influence microbial metabolism in order to regulate depressive outcomes. These dietary-induced changes in the gut microbiota can modulate the production of microbial metabolites, which play vital roles in gut-brain communication. The gut-brain axis facilitates this communication through neural, immune, and endocrine pathways. Alterations in microbial metabolites can influence central nervous system (CNS) functions by impacting neuroplasticity, inflammatory responses, and neurotransmitter levels-all of which are linked to the onset and course of depression. This review highlights recent findings linking dietary components with beneficial changes in gut microbiota composition and reduced depressive symptoms. We also explore the challenges of individual variability in responses to dietary interventions and the long-term sustainability of these strategies. The review underscores the necessity for further longitudinal and mechanistic studies to elucidate the precise mechanisms through which diet and gut microbiota interactions can be leveraged to mitigate depression, paving the way for personalized nutritional therapies.

Recent Advances in the Mechanisms of Postoperative Neurocognitive Dysfunction: A Narrative Review

Postoperative neurocognitive dysfunction (PND) is a prevalent and debilitating complication in elderly surgical patients, characterized by persistent cognitive decline that negatively affects recovery and quality of life. As the aging population grows, the rising number of elderly surgical patients has made PND an urgent clinical challenge. Despite increasing research efforts, the pathophysiological mechanisms underlying PND remain inadequately characterized, underscoring the need for a more integrated framework to guide targeted interventions. To better understand the molecular mechanisms and therapeutic targets of PND, this narrative review synthesized evidence from peer-reviewed studies, identified through comprehensive searches of PubMed, Embase, Cochrane Library, and Web of Science. Key findings highlight neuroinflammation, oxidative stress, mitochondrial dysfunction, neurotransmitter imbalances, microvascular changes, and white matter lesions as central to PND pathophysiology, with particular parallels to encephalocele- and sepsis-associated cognitive impairments. Among these, neuroinflammation, mediated by pathways such as the NLRP3 inflammasome and blood-brain barrier disruption, emerges as a pivotal driver, triggering cascades that exacerbate neuronal injury. Oxidative stress and mitochondrial dysfunction synergistically amplify these effects, while neurotransmitter imbalances and microvascular alterations, including white matter lesions, contribute to synaptic dysfunction and cognitive decline. Anesthetic agents modulate these interconnected pathways, exhibiting both protective and detrimental effects. Propofol and dexmedetomidine demonstrate neuroprotective properties by suppressing neuroinflammation and microglial activation, whereas inhalational anesthetics like sevoflurane intensify oxidative stress and inflammatory responses. Ketamine, with its anti-inflammatory potential, offers promise but requires further evaluation to determine its long-term safety and efficacy. By bridging molecular insights with clinical practice, this review highlights the critical role of personalized anesthetic strategies in mitigating PND and improving cognitive recovery in elderly surgical patients. It aims to inform future research and clinical decision-making to address this multifaceted challenge.

Changes in immuno-inflammatory and antioxidant biomarkers in serum and cerebrospinal fluid of dogs with distemper

Canine distemper virus (CDV) causes a multisystemic disease with central nervous system involvement in dogs. Little is known about the role of immuno-inflammatory and redox-state biomarkers in the pathogenesis and diagnosis of naturally occurring CDV infection. Thus, the objectives of this study were: 1) to evaluate the potential differences in a profile of cytokines/chemokines, and inflammatory and redox-status biomarkers in serum between dogs with CDV-infection and healthy dogs, and 2) possible correlations between serum/blood and cerebrospinal fluid (CSF) of these biomarkers in dogs with CDV-infection. Two groups of dogs were designed: 10 with CDV-infection, and 10 healthy. A total of 13 cytokines/chemokines, 3 inflammatory (C-reactive protein [CRP], haptoglobin [Hp], and butyrylcholinesterase [BChE]) and 3 antioxidants of redox status (cupric reducing antioxidant capacity [CUPRAC], Thiol, and ferric reducing ability of plasma [FRAP]) were analyzed in serum and CSF samples. Serum IL-7, IL-8, MCP-1, CRP, Hp, FRAP and Thiol levels were higher (P < 0.05) in dogs with CDV compared to controls. There were significant (P < 0.05) correlations only in IL-6 and MCP-1 between CSF and serum. In conclusion, deregulated immune response, raised inflammation, and imbalances of redox homeostasis and antioxidant defense status may play role in the pathophysiological mechanism of neurological form of CDV-infection. The combination of clinical features and cytokine biomarkers (IL-7, IL-8 and MCP-1) might facilitate clinical diagnosis for neural involvement in dogs with CDV. Some cytokine/chemokine (IL-6 and MCP-1) in CSF are highly correlated with those of serum, indicating that serum samples could reflect the possible changes of these analytes in CSF.

Mechanistic insight of neurodegeneration due to micro/nano-plastic-induced gut dysbiosis

Despite offering significant conveniences, plastic materials contribute substantially in developing environmental hazards and pollutants. Plastic trash that has not been adequately managed may eventually break down into fragments caused by human or ecological factors. Arguably, the crucial element for determining the biological toxicities of plastics are micro/nano-forms of plastics (MPs/NPs), which infiltrate the mammalian tissue through different media and routes. Infiltration of MPs/NPs across the intestinal barrier leads to microbial architectural dysfunction, which further modulates the population of gastrointestinal microbes. Thereby, it triggers inflammatory mediators (e.g., IL-1α/β, TNF-α, and IFN-γ) by activating specific receptors located in the gut barrier. Mounting evidence indicates that MPs/NPs disrupt host pathophysiological function through modification of junctional proteins and effector cells. Moreover, the alteration of microbial diversity by MPs/NPs causes the breakdown of the blood-brain barrier and translocation of metabolites (e.g., SCFAs, LPS) through the vagus nerve. Potent penetration affects the neuronal networks, neuronal protein accumulation, acceleration of oxidative stress, and alteration of neurofibrillary tangles, and hinders distinctive communicating pathways. Conclusively, alterations of these neurotoxic factors are possibly responsible for the associated neurodegenerative disorders due to the exposure of MPs/NPs. In this review, the hypothesis on MPs/NPs associated with gut microbial dysbiosis has been interlinked to the distinct neurological impairment through the gut-brain axis.

Clinical Implications of Inflammation in Patients With Cirrhosis

Cirrhosis-associated immune dysfunction refers to the concurrent systemic inflammation and immunoparesis evident across the disease spectrum of chronic liver disease, ranging from the low-grade inflammatory plasma milieu that accompanies compensated disease to the intense high-grade inflammatory state with coexistent severe immune paralysis that defines acute decompensation and acute-on-chronic liver failure. Systemic inflammation plays a crucial role in the disease course of cirrhosis and is a key driver for acute decompensation and the progression from compensated to decompensated cirrhosis. Severe systemic inflammation is fundamental to the development of organ dysfunction and failure and, in its most extreme form, acute-on-chronic liver failure. Systemic inflammation propagates the development of hepatic encephalopathy and hepatorenal syndrome-acute kidney injury. It may also be involved in the pathogenesis of further complications such as hepatocellular carcinoma and mental illness. Those patients with the most profound systemic inflammation have the worst prognosis. Systemic inflammation exerts its negative clinical effects through a number of mechanisms including nitric oxide-mediated increased splanchnic vasodilation, immunopathology, and metabolic reallocation.

The unique role of fluoxetine in alleviating depression and anxiety by regulating gut microbiota and the expression of vagus nerve-mediated serotonin and melanocortin-4 receptors

Fluoxetine is a selective serotonin reuptake inhibitor (SSRI) widely used for depression, but its potential effects on gut microbiota regulation and vagus nerve-mediated serotonin receptor expression have not been well studied. We investigated changes in the gut microbiome regulated by fluoxetine and vagus nerve-mediated expression of several serotonin (5-HT) receptor types associated with anxiety and depression. Oral administration of fluoxetine alleviated lipopolysaccharide (LPS)-induced depressive and anxiety behaviors, increased 5-HT1A, 2 C, and melanocortin 4 (MC4) receptor expression, and the composition of Lactobacillus in mice's gut microbiome. In contrast, in the vagotomized group, fluoxetine did not modulate behaviors and receptor expression. Increased Lactobacillus composition was found to correlate significantly with behavioral test results. The importance of Lactobacillus growth to the efficacy of fluoxetine was confirmed by the effectiveness of fluoxetine, which was reduced by co-administering antibiotics. To determine the additional impact of the gut microbiome, we isolated Limosilactobacillus reuteri and Ligilactobacillus murinus, which were increased in the fluoxetine-treated group and administrated. The results showed that administration of each strain improved anxious or depressive behavior, as did fluoxetine, and vagotomy eliminated these effects. These results suggest that fluoxetine administration increases the proportion of Lactobacillus in the gut, which modulates 5-HT1A, 2 C, and MC4 receptor expression through the enteric nervous system and improves depression.

Innate immune memory in chronic HIV and HIV-associated neurocognitive disorders (HAND): potential mechanisms and clinical implications

Although antiretroviral therapy (ART) has dramatically improved the outlook of the HIV/AIDS pandemic, people living with HIV (PLWH) on suppressive therapy are still at higher risk for a range of comorbidities including cardiovascular disease (CVD) and HIV-associated neurocognitive disorders (HAND), among others. Chronic inflammation and immune activation are thought to be an underlying cause of these comorbidities. Many of the factors thought to drive chronic inflammation and immune activation in HIV overlap with factors known to induce trained immunity. Trained immunity is a form of innate immune memory that metabolically and epigenetically reprograms innate immune cells to mount enhanced inflammatory responses upon secondary encounter with unrelated inflammatory stimuli. While this phenotype has been characterized in a variety of disease states in animals and humans, very little is known about its potential contribution to chronic HIV pathogenesis. In this review, a broad overview of innate immune memory in the periphery and the central nervous system (CNS) is provided and the evidence for trained immunity in the context of HIV is considered. In PLWH on ART, this phenotype could contribute to the chronic inflammation and immune activation associated with HIV comorbidities and could complicate HIV cure strategies due to the potential persistence of the phenotype after eradication of the virus. Further research into this immune state in the context of HIV may open the door for new therapeutics aimed at treating HIV comorbidities like HAND.

Association of critically short telomeres with brain and blood markers of ageing and Alzheimer's disease in older adults

BACKGROUND

Accumulation of critically short telomeres (CST) is implicated in decreased tissular regenerative capacity and increased susceptibility to degenerative diseases such as Alzheimer's disease (AD). Telomere shortening has also been associated with age-related brain changes. However, it remains unclear whether CST accumulation is directly associated with AD markers or instead amplifies age-related effects, potentially increasing susceptibility of developing AD in cognitively healthy older adults.

METHODS

This cross-sectional study used baseline data of 129 community-dwelling cognitively healthy older adults from the Age-Well trial (NCT02977819), aged 65 years and older enrolled between 2016 and 2018, in France. Using linear regressions, we analyzed the relationship between an innovative marker of telomere shortening, the percentage of CST (%CST), structural, functional and molecular neuroimaging outcomes, and multiple blood-based biomarkers related to AD pathophysiology. The effect of apolipoprotein E ε4 genotype (APOE4) was assessed on these relationships using interaction analysis.

RESULTS

A higher %CST was associated with lower global kurtosis fractional anisotropy (β = -.230; P = .010), particularly in frontal and temporal regions. A higher %CST was also related to higher plasma levels of Neurofilament light chain (β = .195; P = .020) and a lower subiculum volume (β = -.206; P = .020), although these associations did not meet the threshold for multiple comparisons. %CST was not associated with AD-related neuroimaging markers, including the AD-sensitive gray matter pattern (β = -.060; P = .441), glucose metabolism pattern (β = -.099; P = .372), brain perfusion pattern (β = -.106; P = .694) or hippocampus volume (β = -.106; P = .194). In APOE4 carriers, higher %CST was associated with lower subiculum (β = -.423; P = 0.003), DG (β = -.410; P = 0.018) and CA1 volumes (β = -.373; P = 0.024), even though associations with DG and CA1 volumes did not survive multiple comparison.

CONCLUSIONS

Although an increase in %CST does not appear to be directly linked to the pathophysiology of AD in cognitively healthy older adults, it could heighten the susceptibility of APOE4 carriers to develop AD plausibly due to greater vulnerability to age-related effects. However, longitudinal studies would be necessary to determine whether %CST influences the development and progression of AD later in life.

Alterations of the IKZF1-IKZF2 tandem in immune cells of schizophrenia patients regulate associated phenotypes

Schizophrenia is a complex multifactorial disorder and increasing evidence suggests the involvement of immune dysregulations in its pathogenesis. We observed that IKZF1 and IKZF2, classic immune-related transcription factors (TFs), were both downregulated in patients' peripheral blood mononuclear cells (PBMCs) but not in their brain. We generated a new mutant mouse model with a reduction in Ikzf1 and Ikzf2 to study the impact of those changes. Such mice developed deficits in the three dimensions (positive-negative-cognitive) of schizophrenia-like phenotypes associated with alterations in structural synaptic plasticity. We then studied the secretomes of cultured PBMCs obtained from patients and identified potentially secreted molecules, which depended on IKZF1 and IKZF2 mRNA levels, and that in turn have an impact on neural synchrony, structural synaptic plasticity and schizophrenia-like symptoms in in vivo and in vitro models. Our results point out that IKZF1-IKZF2-dependent immune signals negatively impact on essential neural circuits involved in schizophrenia.

Postoperative cognitive dysfunction in elderly postcardiac surgery patients: progress in rehabilitation application research

Postoperative cognitive dysfunction (POCD) is a prevalent complication of the central nervous system in elderly patients following cardiac surgery. This review aims to provide an overview of the etiology, risk factors, diagnostic assessment, and rehabilitation strategies for cognitive dysfunction occurring after cardiac surgery. The pathogenesis of POCD after cardiac surgery includes cerebral microembolism, neuroinflammation, and cryptogenic strokes. Risk factors are associated with advanced age, diminished preoperative cognitive status, and anesthesia. Cognitive function screening tools used for pre- and postoperative assessments can detect changes in patients' cognitive levels in a timely manner. The timely provision of appropriate rehabilitation methods, including cognitive function training, exercise training, transcranial direct current stimulation, and perioperative acupuncture, is crucial, with emerging technologies such as virtual reality playing an increasingly significant role. In conclusion, POCD is a common postoperative complication in elderly cardiac surgery patients, with age and reduced preoperative cognitive function being the primary risk factors. A comprehensive rehabilitation strategy can more effectively address postoperative cognitive dysfunction in patients.

Understanding immune system dysfunction and its context in mood disorders: psychoneuroimmunoendocrinology and clinical interventions

Mood disorders include a set of psychiatric manifestations of increasing prevalence in our society, being mainly represented by major depressive disorder (MDD) and bipolar disorder (BD). The etiopathogenesis of mood disorders is extremely complex, with a wide spectrum of biological, psychological, and sociocultural factors being responsible for their appearance and development. In this sense, immune system dysfunction represents a key mechanism in the onset and pathophysiology of mood disorders, worsening mainly the central nervous system (neuroinflammation) and the periphery of the body (systemic inflammation). However, these alterations cannot be understood separately, but as part of a complex picture in which different factors and systems interact with each other. Psychoneuroimmunoendocrinology (PNIE) is the area responsible for studying the relationship between these elements and the impact of mind-body integration, placing the immune system as part of a whole. Thus, the dysfunction of the immune system is capable of influencing and activating different mechanisms that promote disruption of the psyche, damage to the nervous system, alterations to the endocrine and metabolic systems, and disruption of the microbiota and intestinal ecosystem, as well as of other organs and, in turn, all these mechanisms are responsible for inducing and enhancing the immune dysfunction. Similarly, the clinical approach to these patients is usually multidisciplinary, and the therapeutic arsenal includes different pharmacological (for example, antidepressants, antipsychotics, and lithium) and non-pharmacological (i.e., psychotherapy, lifestyle, and electroconvulsive therapy) treatments. These interventions also modulate the immune system and other elements of the PNIE in these patients, which may be interesting to understand the therapeutic success or failure of these approaches. In this sense, this review aims to delve into the relationship between immune dysfunction and mood disorders and their integration in the complex context of PNIE. Likewise, an attempt will be made to explore the effects on the immune system of different strategies available in the clinical approach to these patients, in order to identify the mechanisms described and their possible uses as biomarkers.

Calcium signaling at the interface between astrocytes and brain inflammation

Astrocytes are the most prevalent glial cells of the brain and mediate vital roles in the development and function of the nervous system. Astrocytes, along with microglia, also play key roles in initiating inflammatory immune responses following brain injury, stress, or disease-related triggers. While these glial immune responses help contain and resolve cellular damage to the brain, dysregulation of astrocyte activity can in some cases amplify inflammation and worsen impact on neural tissue. As nonexcitable cells, astrocytes excitability is regulated primarily by Ca2+ signals that control key functions such as gene expression, release of inflammatory mediators, and cell metabolism. In this review, we examine the molecular and functional architecture of Ca2+ signaling networks in astrocytes and their impact on astrocyte effector functions involved in inflammation and immunity.

Fasudil attenuates lipopolysaccharide-induced cognitive impairment in C57BL/6 mice through anti-oxidative and anti-inflammatory effects: Possible role of aquaporin-4

Introduction

Processes that generate systemic inflammation are strongly associated with neurodegenerative diseases. This study aimed to explore the potential anti-oxidative and anti-inflammatory effects of fasudil and its role in modulating aquaporin-4 (AQP-4) to improve cognitive impairment in a systemic inflammation model induced by lipopolysaccharide (LPS).

Method

fourty C57BL/6 mice were assigned to four groups, including sham, LPS, sham+fasudil, and LPS+fasudil). Intraperitoneal LPS was given (500 μg/kg/day) at hours 0, 24, 48, and 72, and fasudil (30 mg/kg) administered intraperitoneal injections 2 hours after LPS injection. The open field, Y-maze, and Novel object tasks was used to assess learning and memory. The levels of malondialdehyde (MDA), superoxide dismutase (SOD), interleukin-10 (IL-10), and tumor necrosis factor-α (TNF-α) in the hippocampus also measured as markers of oxidative stress and inflammation. Furthermore, the expression of AQP-4 measured in the intact and experimental groups.

Results

The results showed that Fasudil significantly improved memory and anxiety behavior induced by LPS in the open field maze, spatial recognition memory in the Y-maze, and performance in the novel object recognition task. It also mitigates hippocampal MDA and SOD levels. Additionally, fasudil ameliorated LPS-induced hippocampal levels of TNFα and IL-10 and increased hippocampal levels of AQP-4 expression in mice.

Conclusion

Our results suggest that fasudil in the LPS model of systemic inflammation could improve cognition by suppressing oxidative stress and inflammation and increasing AQP-4 protein expression. These findings highlighted the potential of fasudil as a neuroprotective agent. However, further research is required to fully understand its neuroprotective properties in the treatment of neurodegenerative disorders.

The impact of anti-inflammatory therapy on Parkinson's disease incidence: A retrospective cohort study

BACKGROUND

Previous research suggests shared pathophysiology between Parkinson's Disease (PD) and autoimmune disorders, with inflammation reduction as a potential PD intervention. The impact of anti-tumor necrosis factor (anti-TNF) and anti-interleukin (IL)-17 drugs on PD development has yielded conflicting results.

OBJECTIVES

The study investigated the association between PD incidence and immunosuppressive anti-inflammatory drugs in patients with autoimmune diseases (rheumatoid arthritis, ulcerative colitis, Crohn's disease, ankylosing spondylitis, psoriasis/psoriatic arthritis).

METHODS

A retrospective study was conducted using data from 2014 to 2022 from the US Komodo Health claims database. Two cohorts of patients diagnosed with autoimmune diseases were designed: 1) exposed to biologic disease-modifying antirheumatic drugs (bDMARDS e.g., anti-TNF/anti-IL-17 drugs) and 2) absent such exposure. Person-time incidence rates of PD per 100 person-years (PY) and incidence rate ratios (IRRs) were calculated and covariate adjusted via Poisson regressions.

RESULTS

Among 2,105,677 identified patients with autoimmune disease, 114,082 were treated with anti-TNF/anti-IL-17 and 1,991,595 were not. Unadjusted analyses indicated lower PD incidence in those treated with bDMARDscompared to the not treated (0.661 vs 0.949 per 100-PY; IRR 0.696 [95 % CI: 0.669-0.724]). Multivariate Poisson models comparing cohorts exposed to bDMARDs vs those lacking exposure resulted in significantly lower risk of PD (adjusted IRR 0.77 [95 % CI 0.74-0.80], p-value <0.0001). For patients exposed to anti-TNF or anti-IL-17 therapies, the IRRs were 0.77 (95 % CI 0.74-0.81) and 0.64 (95 % CI 0.52-0.80), respectively (p-values<0.001).

CONCLUSIONS

The results suggest that reduced systemic inflammation via anti-TNF or anti-IL-17 treatment may decrease PD risk in patients with autoimmune diseases.

Study of the immune disorder and metabolic dysregulation underlying mental abnormalities caused by exposure to narrow confined spaces

Prolonged confinement in cramped spaces can lead to derangements in brain function/structure, yet the underlying mechanisms remain unclear. To investigate, we subjected mice to restraint stress to simulate long-term narrow and enclosed space confinement, assessing their mental state through behavioral tests. Stressed mice showed reduced center travel and dwell time in the Open Field Test and increased immobility in the Tail Suspension Test. We measured lower hippocampal brain-derived neurotrophic factor levels and cortical monoamine neurotransmitters (5-HT and NE) in the stressed group. Further examination of the body's immune levels and serum metabolism revealed immune dysregulation and metabolic imbalance in the stressed group. The results of the metabolic network regulation analysis indicate that the targets affected by these differential metabolites are involved in several metabolic pathways that the metabolites themselves participate in, such as the "long-term depression" and "purine metabolism" pathways. Additionally, these targets are also associated with numerous immune-related pathways, such as the TNF, NF-κB, and IL-17 signaling pathways, and these findings were validated using GEO dataset analysis. Molecular docking results suggest that differential metabolites may regulate specific immune factors such as TNF-α, IL-1β, and IL-6, and these results were confirmed in experiments. Our research findings suggest that long-term exposure to confined and narrow spaces can lead to the development of psychopathologies, possibly mediated by immune system dysregulation and metabolic disruption.

Crosstalk between peripheral inflammation and brain: Focus on the responses of microglia and astrocytes to peripheral challenge

A growing body of evidence supports the link between peripheral inflammation and impairment of neurologic functions, including mood and cognitive abilities. The pathogenic event connecting peripheral inflammation and brain dysfunction is represented by neuroinflammation, a pathogenic phenomenon that provides an important contribution to neurodegeneration and cognitive decline also in Alzheimer's, Parkinson's, Huntington's diseases, as well as in Multiple Sclerosis. It is driven by resident brain immune cells, microglia and astrocytes, that acquire an activated phenotype in response to proinflammatory molecules moving from the periphery to the brain parenchyma. Although a huge progress has been made in clarifying cellular and molecular mechanisms bridging peripheral and central inflammation, a clear picture has not been achieved so far. Therefore, experimental models are of crucial relevance to clarify knowledge gaps in this regard. Many findings demonstrate that systemic inflammation induced by pathogen-associated molecular patterns, such as lipopolysaccharide (LPS), is able to trigger neuroinflammation. Therefore, LPS-administration is widely considered a useful tool to study this phenomenon. On this basis, the present review will focus on in vivo studies based on acute and subacute effects of systemic administration of LPS, with special attention on the state of art of microglia and astrocyte response to peripheral challenge.

Impact of Chondrocyte Inflammation on Glial Cell Activation: The Mediating Role of Nitric Oxide

OBJECTIVE

This study investigates how the inflammatory response of ATDC5 murine chondrogenic cells influences the activity of C6 (rat) and GL261 (mouse) glial cell lines. Prior research suggested nitric oxide (NO) involvement in cartilage-immune crosstalk. The current study explores whether NO, produced by inflamed chondrocytes, mediates signaling between chondrocytes and glial cells.

DESIGN

Pre-challenged ATDC5 cells with 250 ng/ml of lipopolysaccharide (LPS) were cocultured with GL261 or C6 glioma cells for 24 h with a transwell culture system. Cell viability was assessed using MTT assay. Gene and protein expression were evaluated by qRT-PCR and WB, respectively.

RESULTS

Real-time reverse transcription-polymerase chain reaction (RT-qPCR) indicated statistically significant upregulation of LCN2, IL-6, TNF-α, IL-1β, and GFAP in glial cells following 24-h coculture with challenged ATDC5 cells. Suppression of LPS-induced NO production by aminoguanidine decreased LPS-mediated LCN2 and IL-6 expression in glioma cells. We identified also the involvement of the ERK1/2 and AKT signaling pathways in the glial neuroinflammatory response.

CONCLUSIONS

This study demonstrates, for the first time, that NO produced by inflamed murine chondrocytes mediated pro-inflammatory responses in glial cells via ERK1/2 and AKT signaling, highlighting a potential mechanism linking cartilage NO to neuroinflammation and chronic pain in osteoarthritis.

In Vitro Assessment of the Neuroprotective Effects of Pomegranate (Punica granatum L.) Polyphenols Against Tau Phosphorylation, Neuroinflammation, and Oxidative Stress

BACKGROUND

Oxidative stress and chronic inflammation, at both the systemic and the central level, are critical early events in atherosclerosis and Alzheimer's disease (AD).

PURPOSE

To investigate the oxidative stress-, inflammation-, and Tau-phosphorylation-lowering effects of pomegranate polyphenols (PPs) (punicalagin, ellagic acid, peel, and aril extracts).

METHODS

We used flow cytometry to quantify the protein expression of proinflammatory cytokines (IL-1β) and anti-inflammatory mediators (IL-10) in THP-1 macrophages, as well as M1/M2 cell-specific marker (CD86 and CD163) expression in human microglia HMC3 cells. The IL-10 protein expression was also quantified in U373-MG human astrocytes. The effect of PPs on human amyloid beta 1-42 (Aβ1-42)-induced oxidative stress was assessed in the microglia by measuring ROS generation and lipid peroxidation, using 2',7'-dichlorofluorescein diacetate (DCFH-DA) and thiobarbituric acid reactive substance (TBARS) tests, respectively. Neuronal viability and cell apoptotic response to Aβ1-42 toxicity were assayed using the MTT (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide) assay and the annexin-V-FITC apoptosis detection kit, respectively. Finally, flow cytometry analysis was also performed to evaluate the ability of PPs to modulate Aβ1-42-induced Tau-181 phosphorylation (pTau-181).

RESULTS

Our data indicate that PPs are significantly (p < 0.05) effective in countering Aβ1-42-induced inflammation through increasing the anti-inflammatory cytokines (IL-10) in U373-MG astrocytes and THP1 macrophages and decreasing proinflammatory marker (IL-1β) expression in THP1 macrophages. The PPs were also significantly (p < 0.05) effective in inducing the phenotypic transition of THP-1 macrophages and microglial cells from M1 to M2 by decreasing CD86 and increasing CD163 surface receptor expression. Moreover, our treatments have a significant (p < 0.05) beneficial impact on oxidative stress, illustrated in the reduction in TBARS and ROS generation. Our treatments have significant (p < 0.05) cell viability improvement capacities and anti-apoptotic effects on human H4 neurons. Furthermore, our results suggest that Aβ1-42 significantly (p < 0.05) increases pTau-181. This effect is significantly (p < 0.05) attenuated by arils, peels, and punicalagin and drastically reduced by the ellagic acid treatment.

CONCLUSION

Overall, our results attribute to PPs anti-inflammatory, antioxidant, anti-apoptotic, and anti-Tau-pathology potential. Future studies should aim to extend our knowledge of the potential role of PPs in Aβ1-42-induced neurodegeneration, particularly concerning its association with the tauopathy involved in AD.

Novelties on Neuroinflammation in Alzheimer's Disease-Focus on Gut and Oral Microbiota Involvement

Recent studies underscore the role of gut and oral microbiota in influencing neuroinflammation through the microbiota-gut-brain axis, including in Alzheimer's disease (AD). This review aims to provide a comprehensive synthesis of recent findings on the involvement of gut and oral microbiota in the neuroinflammatory processes associated with AD, emphasizing novel insights and therapeutic implications. This review reveals that dysbiosis in AD patients' gut and oral microbiota is linked to heightened peripheral and central inflammatory responses. Specific bacterial taxa, such as Bacteroides and Firmicutes in the gut, as well as Porphyromonas gingivalis in the oral cavity, are notably altered in AD, leading to significant changes in microglial activation and cytokine production. Gut microbiota alterations are associated with increased intestinal permeability, facilitating the translocation of endotoxins like lipopolysaccharides (LPS) into the bloodstream and exacerbating neuroinflammation by activating the brain's toll-like receptor 4 (TLR4) pathways. Furthermore, microbiota-derived metabolites, including short-chain fatty acids (SCFAs) and amyloid peptides, can cross the blood-brain barrier and modulate neuroinflammatory responses. While microbial amyloids may contribute to amyloid-beta aggregation in the brain, certain SCFAs like butyrate exhibit anti-inflammatory properties, suggesting a potential therapeutic avenue to mitigate neuroinflammation. This review not only highlights the critical role of microbiota in AD pathology but also offers a ray of hope by suggesting that modulating gut and oral microbiota could represent a novel therapeutic strategy for reducing neuroinflammation and slowing disease progression.

Exploratory Randomised Trial of Tranexamic Acid to Decrease Postoperative Delirium in Adults Undergoing Lumbar Fusion: A trial stopped early

Background

Postoperative delirium may be mediated by perioperative systemic- and neuro-inflammation. By inhibiting the pro-inflammatory actions of plasmin, tranexamic acid (TXA) may decrease postoperative delirium. To explore this hypothesis, we modified an ongoing randomised trial of TXA, adding measures of postoperative delirium, cognitive function, systemic cytokines, and astrocyte activation.

Methods

Adults undergoing elective posterior lumbar fusion randomly received intraoperative intravenous TXA (n=43: 10 mg kg-1 loading dose, 2 mg kg-1 h-1 infusion) or Placebo (n=40). Blood was collected pre- and at 24 h post-operatively (n=32) for biomarkers of systemic inflammation (cytokines) and astrocyte activation (S100B). Participants had twice daily delirium assessments using the 3-minute diagnostic interview for Confusion Assessment Method (n=65). Participants underwent 4 measures of cognitive function preoperatively and during post-discharge follow-up.

Results

Delirium incidence in the TXA group (7/32=22%) was not significantly less than in the Placebo group (11/33=33%); P=0.408, absolute difference=11%, relative difference=33%, effect size = -0.258 (95% CI -0.744 to 0.229). In the Placebo group (n=16), delirium severity was associated with the number of instrumented vertebral levels (P=0.001) and with postoperative interleukin -8 and -10 concentrations (P=0.00008 and P=0.005, respectively) and these associations were not significantly modified by TXA. In the Placebo group, delirium severity was associated with S100B concentration (P=0.0009) and the strength of the association was decreased by TXA (P=0.002).

Conclusions

A potential 33% relative decrease in postoperative delirium incidence justifies an adequately powered clinical trial to determine if intraoperative TXA decreases delirium in adults undergoing lumbar fusion.

Prediction and validation of mild cognitive impairment in occupational dust exposure population based on machine learning

OBJECTIVE

Workers exposed to dust for extended periods may experience varying degrees of cognitive impairment. However, limited research exists on the associated risk factors. This study aims to identify key variables using machine learning algorithms (ML) and develop a model to predict the occurrence of mild cognitive impairment in miners.

METHODS

A total of 1938 miners were included in the study. Univariate analysis and multivariable logistic regression were employed to identify independent risk factors for cognitive impairment among miners. The dataset was randomly divided into a training set and a validation set in an 8:2 ratio of 1550 and 388 individuals, respectively. An additional group of 351 miners was collected as a test set for cognitive impairment assessment. Seven machine learning algorithms, including XGBoost, Logistic Regression, Random Forest, Complement Naive Bayes, Multi-layer Perceptron, Support Vector Machine, and K-Nearest Neighbors, were used to establish a predictive model for mild cognitive impairment in the dust-exposed population, based on baseline characteristics of the workers. The predictive performance of the models was evaluated using the Area Under the Receiver Operating Characteristic Curve (AUC), and the XGBoost model was further explained using the Shapley Additive exPlanations (SHAP) package. Cognitive function assessments using rank sum tests were conducted to compare differences in cognitive domains between the mild cognitive impairment group and the normal group.

RESULTS

Univariate and multivariable logistic regression analyses revealed that education level, Age, Work years, SSRS (Self-Rating Scale for Stress), and HAMA (Hamilton Anxiety Rating Scale) were independent risk factors for cognitive impairment among dust-exposed workers. Comparative analysis of the performance of the seven machine learning algorithms demonstrated that XGBoost (training set: AUC=0.959, validation set: AUC=0.795) and Logistic Regression (training set: AUC=0.818, validation set: AUC=0.816) models exhibited superior predictive performance. Results from the test set showed that the AUC of the XGBoost model (AUC=0.913) outperformed the Logistic Regression model (AUC=0.778). Miners with mild cognitive impairment exhibited significant impairments (p<0.05) in visual-spatial abilities, attention, abstract thinking, and memory areas.

CONCLUSION

Machine learning algorithms can predict the risk of cognitive impairment in this population, with the XGBoost algorithm showing the best performance. The developed model can guide the implementation of appropriate preventive measures for dust-exposed workers.

Impact of Intraoperative Blood Transfusion on Cerebral Injury in Pediatric Patients Undergoing Congenital Septal Heart Defect Surgery

Background: The components of donor blood themselves have the potential to initiate a systemic inflammatory response and exacerbate neuroinflammation, resulting in subsequent cerebral injury. The aim of this study was to establish the role of transfusion in the development of cerebral injury during the correction of congenital heart defects in children. Material and Methods: A total of 78 patients aged from 1 to 78 months, with body weights ranging from 3.3 to 21.5 kg, were investigated. Biomarkers of cerebral injury and systemic inflammatory response were studied at three time points. First: prior to the surgical intervention. Second: after the completion of cardiopulmonary bypass. Third: 16 h after the conclusion of the surgery. Results: The strongest correlation was found for S-100-β protein with the volume of transfusion at the second (Rho = 0.48, p = 0.00065) and third time points (Rho = 0.36, p = 0.01330). Neuron-specific enolase demonstrated a similar trend: Rho = 0.41 and p = 0.00421 after the completion of cardiopulmonary bypass. Conclusions: The use of red blood cell suspension and its dosage per kilogram of body weight correlated with the biomarkers of cerebral injury and systemic inflammatory response with moderate to significant strength.

Serum TNFα and IL-17A levels may predict increased depressive symptoms: findings from the Shika Study cohort project in Japan

BACKGROUND

Low-grade systemic inflammation may be a key player in the immune activation that has been reported for mental health deterioration. We hypothesised that elevated serum levels of inflammatory cytokines increase neuroinflammation and exacerbate depressive symptoms.

METHODS

The participants were part of a cohort study for whom data was available for both 2015 and 2019. In 2015, blood samples were collected from 232 participants. Their depressive symptoms were assessed both 2015 and 2019 using the Centre for Epidemiologic Studies Depression Scale (CES-D) (n = 33). The multiplex immunoassay system (Luminex® 200) was used to measure the serum concentrations of IL-6, IL-10, IL-12, IL-17A and TNFα. Data were analysed using linear models with the level of significance considered to be p < 0.05.

RESULTS

After controlling for age, BMI, smoking and alcohol consumption, in 2015 the serum concentrations of IL-17A and TNFα in 2015 were significantly positively associated with the CES-D scores of women (standardised β (B) = .027, p < 0.01 and B = 0.26, p < 0.01, respectively). The serum concentrations of IL-17A and TNFα of men were significantly positively associated with the CES-D scores of 2019 (B = 0.62, p = 0.02 and B = 0.59, p = 0.02, respectively).

CONCLUSIONS

In this cross-sectional study, we found a significant positive correlation between the depressive symptoms and serum TNFα and IL-17A levels of women. In addition, our longitudinal findings suggest the possibility that TNFα and IL-17A could elevate the depressive symptoms of men.

Host-diet-microbiota interplay in intestinal nutrition and health

The intestine is populated by a complex and dynamic assortment of microbes, collectively called gut microbiota, that interact with the host and contribute to its metabolism and physiology. Diet is considered a key regulator of intestinal microbiota, as ingested nutrients interact with and shape the resident microbiota composition. Furthermore, recent studies underscore the interplay of dietary and microbiota-derived nutrients, which directly impinge on intestinal stem cells regulating their turnover to ensure a healthy gut barrier. Although advanced sequencing methodologies have allowed the characterization of the human gut microbiome, mechanistic studies assessing diet-microbiota-host interactions depend on the use of genetically tractable models, such as Drosophila melanogaster. In this review, we first discuss the similarities between the human and fly intestines and then we focus on the effects of diet and microbiota on nutrient-sensing signaling cascades controlling intestinal stem cell self-renewal and differentiation, as well as disease. Finally, we underline the use of the Drosophila model in assessing the role of microbiota in gut-related pathologies and in understanding the mechanisms that mediate different whole-body manifestations of gut dysfunction.

"Let's talk about sex, inflammaging, and cognition, baby": A meta-analysis and meta-regression of 106 case-control studies on mild cognitive impairment and Alzheimer's disease

Background

Chronic inflammation is recognised as an important component of Alzheimer's disease (AD), yet its relationship with cognitive decline, sex-differences, and age is not well understood. This study investigated the relationship between inflammatory markers, cognition, sex, and age in individuals with mild cognitive impairment (MCI) and AD.

Methods

A systematic review was performed to identify case-control studies which measured cognitive function and inflammatory markers in serum, plasma, and cerebrospinal fluid in individuals with MCI or AD compared with healthy control (HC) participants. Meta-analysis was performed with Hedges' g calculated in a random effects model. Meta-regression was conducted using age, sex, and mini-mental status exam (MMSE) values.

Results

A total of 106 studies without a high risk of bias were included in the meta-analysis including 18,145 individuals: 5625 AD participants, 3907 MCI participants, and 8613 HC participants. Combined serum and plasma meta-analysis found that IL1β, IL6, IL8, IL18, CRP, and hsCRP were significantly raised in individuals with AD compared to HC. In CSF, YKL40, and MCP-1 were raised in AD compared to HC. YKL40 was also raised in MCI compared to HC. Meta-regression analysis highlighted several novel findings: MMSE was negatively correlated with IL6 and positively correlated with IL1α in AD, while in MCI studies, MMSE was negatively correlated with IL8 and TNFα. Meta-regression also revealed sex-specific differences in levels of IL1α, IL4, IL6, IL18, hsCRP, MCP-1, and YKL-40 across AD and MCI studies, and age was found to account for heterogeneity of CRP, MCP-1, and IL4 in MCI and AD.

Conclusion

Elevated levels of IL6 and YKL40 may reflect microglial inflammatory activity in both MCI and AD. Systemic inflammation may interact with the central nervous system, as poor cognitive function in individuals with AD and MCI was associated with higher levels of serum and plasma proinflammatory cytokines IL6 and TNFα. Moreover, variations of systemic inflammation between males and females may be modulated by sex-specific hormonal changes, such as declining oestrogen levels in females throughout the menopause transition. Longitudinal studies sampling a range of biospecimen types are needed to elucidate the nuances of the relationship between inflammation and cognition in individuals with MCI and AD, and understand how systemic and central inflammation differentially impact cognitive function.

Osteoarthritis and Neurological Disorder Diagnoses in Adults: A Meta-Analysis Examining Associations With Parkinson's Disease, Multiple Sclerosis, and Alzheimer's Disease

Osteoarthritis (OA) is a highly prevalent joint disorder that is emerging as a global threat to health. OA is associated with low-grade chronic systemic inflammation that can affect overall health, leading to a sedentary lifestyle and potentially increased risk of neurological disorders (ND) such as Alzheimer's disease (AD), Parkinson's disease (PD), and multiple sclerosis (MS). A meta-analysis was conducted following the Preferred Reporting Items for 2020 Systematic Reviews and Meta-Analyses (PRISMA) guidelines. MEDLINE, Web of Science, and Embase databases were searched to identify records. The inclusion criteria for this analysis were original research articles reporting on OA and neurological disorder diagnoses (AD, PD, or MS) with non-OA comparator groups. Logarithmic odds ratios (LORs) were calculated and input into a random-effects meta-analysis using the restricted maximum-likelihood estimator. Subgroup analyses examined the associations between OA, AD, PD, and MS. A subsequent meta-regression analysis was performed to explore potential sources of heterogeneity, focusing on comorbidities and demographic factors. Publication bias was evaluated using funnel plots, Egger's test, and trim-and-fill analysis. Nine studies were included in this meta-analysis (six case-control designs, two cross-sectional designs, and one population-based cohort design) of 1,837,716 cases. The pooled odds ratio (OR) indicated a significant association between OA and ND diagnosis (OR = 1.246; confidence interval (CI): 1.01-1.53). Subsequent subgroup analyses were not statistically significant but indicated an association with PD (OR = 1.31, CI: 0.80-2.12), MS (OR = 1.12, CI: 0.80-2.81), and AD (OR = 1.50, CI: 0.80-2.81). This meta-analysis revealed that individuals with OA have approximately 25% higher odds of an accompanying ND diagnosis compared to those without OA. Importantly, these findings represent statistical associations only and do not imply causation or directionality but provide insight into factors, including shared risk factors, overlapping symptoms, or other underlying mechanisms that may influence the observed relationships.

Exploring the Therapeutic Potential of Terpenoids for Depression and Anxiety

This review focus on the terpenoids as potential therapeutic agents for depression and anxiety disorders, which naturally found in a variety of plants and exhibit a wide range of biological activities. Among the terpenoids discussed in this review are α-pinene, β-caryophyllene, α-phellandrene, limonene, β-linalool, 1, 8-cineole, β-pinene, caryophyllene oxide, p-cymene, and eugenol. All of these compounds have been studied extensively regarding their pharmacological properties, such as neuroprotective effect, anti-inflammation, antibacterial, regulation of neurotransmitters and antioxidant effect. Preclinical evidence are reviewed to highlight their diverse mechanisms of action and therapeutic potential to support antidepressant and anxiolytic properties. Additionally, challenges and future directions are also discussed to emphasize therapeutic utility of terpenoids for mental health disorders. Overall, this review provides a promising role of terpenoids as novel therapeutic agents for depression and anxiety, with potential implications for the development of more effective and well-tolerated treatments in the field of psychopharmacology.

Fascial Manual Medicine: A Continuous Evolution

From the perspective of fascial manual medicine (FMM), the body should not be considered as a set of compartments, but as a functional continuum, where most of the tissues (considering embryology) are fascia. The cells that make up the fascia can use multiple strategies to communicate, with neighboring cells, with the tissue to which they belong, and with the entire body, thanks to biochemical (microscopy) and electromagnetic (nanoscopy) possibilities. These multiple capacities to send and receive information make the border or layer of the different tissues seem absent. All the manual techniques that profess to be the only ones that work on the patient's symptoms, dictating a standardized manual procedure that all patients should undergo, represent a clinical deviation. Likewise, thinking that the manual approach can provide biomechanical stimuli only to a single specific structure or layer is a conceptual error. This narrative review briefly reviews the history of fascial-related nomenclature and how the fascial system is currently considered, posing new reflections on how the fascial continuum could be conceived by practitioners who apply FMM in the clinic, such as osteopaths, chiropractors, and physiotherapists.

A brain microbiome in salmonids at homeostasis

Ectotherms have peculiar relationships with microorganisms. For instance, bacteria are recovered from the blood and internal organs of healthy teleosts. However, the presence of microbial communities in the healthy teleost brain has not been proposed. Here, we report a living bacterial community in the brain of healthy salmonids with bacterial loads comparable to those of the spleen and 1000-fold lower than in the gut. Brain bacterial communities share >50% of their diversity with gut and blood bacterial communities. Using culturomics, we obtained 54 bacterial isolates from the brains of healthy trout. Comparative genomics suggests that brain bacteria may have adaptations for niche colonization and polyamine biosynthesis. In a natural system, Chinook salmon brain microbiomes shift from juveniles to reproductively mature adults. Our study redefines the physiological relationships between the brain and bacteria in teleosts. This symbiosis may endow salmonids with a direct mechanism to sense and respond to environmental microbes.

A novel tauopathy model mimicking molecular and spatial aspects of human tau pathology

Creating a mouse model that recapitulates human tau pathology is essential for developing strategies to intervene in tau-induced neurodegeneration. However, mimicking the pathological features seen in human pathology often involves a trade-off with artificial effects such as unexpected gene insertion and neurotoxicity from the expression system. To overcome these issues, we developed the rTKhomo mouse model by combining a transgenic CaMKII-tTA system with a P301L mutated 1N4R human tau knock-in at the Rosa26 locus with a C57BL/6J background. This model closely mimics human tau pathology, particularly in the hippocampal CA1 region, showing age-dependent tau accumulation, neuronal loss and neuroinflammation. Notably, whole-brain 3D staining and light-sheet microscopy revealed a spatial gradient of tau deposition from the entorhinal cortex to the hippocampus, similar to the spatial distribution of Braak neurofibrillary tangle staging. Furthermore, [18F]PM-PBB3 positron emission tomography imaging enabled the quantification and live monitoring of tau deposition. The rTKhomo mouse model shows potential as a promising next-generation preclinical tool for exploring the mechanisms of tauopathy and for developing interventions targeting the spatial progression of tau pathology.

Early brain neuroinflammatory and metabolic changes identified by dual tracer microPET imaging in mice with acute liver injury

Background

Acute liver injury (ALI) that progresses into acute liver failure (ALF) is a life-threatening condition with an increasing incidence and associated costs. Acetaminophen (N-acetyl-p-aminophenol, APAP) overdosing is among the leading causes of ALI and ALF in the Northern Hemisphere. Brain dysfunction defined as hepatic encephalopathy is one of the main diagnostic criteria for ALF. While neuroinflammation and brain metabolic alterations significantly contribute to hepatic encephalopathy, their evaluation at early stages of ALI remained challenging. To provide insights, we utilized post-mortem analysis and non-invasive brain micro positron emission tomography (microPET) imaging of mice with APAP-induced ALI.

Methods

Male C57BL/6 mice were treated with vehicle or APAP (600 mg/kg, i.p.). Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), liver damage (using H&E staining), hepatic and serum IL-6 levels, and hippocampal IBA1 (using immunolabeling) were evaluated at 24h and 48h. Vehicle and APAP treated animals also underwent microPET imaging utilizing a dual tracer approach, including [11C]-peripheral benzodiazepine receptor ([11C]PBR28) to assess microglia/astrocyte activation and [18F]-fluoro-2-deoxy-2-D-glucose ([18F]FDG) to assess energy metabolism. Brain images were pre-processed and evaluated using conjunction and individual tracer uptake analysis.

Results

APAP-induced ALI and hepatic and systemic inflammation were detected at 24h and 48h by significantly elevated serum ALT and AST levels, hepatocellular damage, and increased hepatic and serum IL-6 levels. In parallel, increased microglial numbers, indicative for neuroinflammation were observed in the hippocampus of APAP-treated mice. MicroPET imaging revealed overlapping increases in [11C]PBR28 and [18F]FDG uptake in the hippocampus, thalamus, and habenular nucleus indicating microglial/astroglial activation and increased energy metabolism in APAP-treated mice (vs. vehicle-treated mice) at 24h. Similar significant increases were also found in the hypothalamus, thalamus, and cerebellum at 48h. The individual tracer uptake analyses (APAP vs vehicle) at 24h and 48h confirmed increases in these brain areas and indicated additional tracer- and region-specific effects including hippocampal alterations.

Conclusion

Peripheral manifestations of APAP-induced ALI in mice are associated with brain neuroinflammatory and metabolic alterations at relatively early stages of disease progression, which can be non-invasively evaluated using microPET imaging and conjunction analysis. These findings support further PET-based investigations of brain function in ALI/ALF that may inform timely therapeutic interventions.

Brain and Lung Biomarker Responses to Hyperoxic Hypobaric Decompression

INTRODUCTION: Biomarker responses to intensive decompression indicate systemic proinflammatory responses and possible neurological stress. To further investigate responses, 12 additional brain and lung biomarkers were assayed.METHODS: A total of 15 healthy men (20 to 50 yr) undertook consecutive same-day ascents to 25,000 ft (7620 m), following denitrogenation, breathing 100% oxygen. Venous blood was sampled at baseline (T0), after the second ascent (T8), and next morning (T24). Soluble protein markers of brain and lung insult were analyzed by enzyme-linked immunosorbent assay with plasma microparticles quantified using flow cytometry.RESULTS: Levels of monocyte chemoattractant protein-1 and high mobility group box protein 1 were elevated at T8, by 36% and 16%, respectively, before returning to baseline. Levels of soluble receptor for advanced glycation end products fell by 8%, recovering by T24. Brain-derived neurotrophic factor rose by 80% over baseline at T24. Monocyte microparticle levels rose by factors of 3.7 at T8 and 2.7 at T24 due to early and late responses in different subjects. Other biomarkers were unaffected or not detected consistently.DISCUSSION: The elevated biomarkers at T8 suggest a neuroinflammatory response, with later elevation of brain-derived neurotrophic factor at T24 indicating an ongoing neurotrophic response and incomplete recovery. A substantial increase at T8 in the ratio of high mobility group box protein 1 to soluble receptor for advanced glycation end products suggests this axis may mediate the systemic inflammatory response to decompression. The mechanism of neuroinflammation is unclear but elevation of monocyte microparticles and monocyte chemoattractant protein-1 imply a key role for activated monocytes and/or macrophages.Connolly DM, Madden LA, Edwards VC, Lee VM. Brain and lung biomarker responses to hyperoxic hypobaric decompression. Aerosp Med Hum Perform. 2024; 95(9):667-674.

Modulating the biosynthesis and TLR4-interaction of lipopolysaccharide as an approach to counter gut dysbiosis and Parkinson's disease: Role of phyto-compounds

The prevalence of the world's second leading neurodegenerative disorder Parkinson's disease (PD) is well known while its pathogenesis is still a topical issue to explore. Clinical and experimental reports suggest the prevalence of disturbed gut microflora in PD subjects, with an abundance of especially Gram-negative bacteria. The endotoxin lipopolysaccharide (LPS) released from the outer cell layer of these bacteria interacts with the toll-like receptor 4 (TLR4) present on the macrophages and it stimulates the downstream inflammatory cascade in both the gut and brain. Recent research also suggests a positive correlation between LPS, alpha-synuclein, and TLR4 levels, which indicates the contribution of a parallel LPS-alpha-synuclein-TLR4 axis in stimulating inflammation and neurodegeneration in the gut and brain, establishing a body-first type of PD. However, owing to the novelty of this paradigm, further investigation is mandatory. Modulating LPS biosynthesis and LPS-TLR4 interaction can ameliorate gut dysbiosis and PD. Several synthetic LpxC (UDP-3-O-(R-3-hydroxymyristoyl)-N-acetylglucosamine deacetylase; LPS-synthesizing enzyme) inhibitors and TLR4 antagonists are reported to show beneficial effects including neuroprotection in PD models, however, are not devoid of side effects. Plant-derived compounds have been long documented for their benefits as nutraceuticals and thus to search for effective, safer, and multitarget therapeutics, the present study focused on summarizing the evidence reporting the potential of phyto-compounds as LpxC inhibitors and TLR4 antagonists. Studies demonstrating the dual potential of phyto-compounds as the modulators of LpxC and TLR4 have not yet been reported. Also, very few preliminary studies have reported LpxC inhibition by phyto-compounds. Nevertheless, remarkable neuroprotection along with TLR4 antagonism has been shown by curcumin and juglanin in PD models. The present review thus provides a wide look at the research progressed to date in discovering phyto-compounds that can serve as LpxC inhibitors and TLR4 antagonists. The study further recommends the need for expanding the search for potential candidates that can render dual protection by inhibiting both the biosynthesis and TLR4 interaction of LPS. Such multitarget therapeutic intervention is believed to bring fruitful yields in countering gut dysbiosis, neuroinflammation, and dopaminergic neuron damage in PD patients through a single treatment paradigm.

"Inflamed" depression: A review of the interactions between depression and inflammation and current anti-inflammatory strategies for depression

Depression is a common mental disorder, the effective treatment of which remains a challenging issue worldwide. The clinical pathogenesis of depression has been deeply explored, leading to the formulation of various pathogenic hypotheses. Among these, the monoamine neurotransmitter hypothesis holds a prominent position, yet it has significant limitations as more than one-third of patients do not respond to conventional treatments targeting monoamine transmission disturbances. Over the past few decades, a growing body of research has highlighted the link between inflammation and depression as a potential key factor in the pathophysiology of depression. In this review, we first summarize the relationship between inflammation and depression, with a focus on the pathophysiological changes mediated by inflammation in depression. The mechanisms linking inflammation to depression as well as multiple anti-inflammatory strategies are also discussed, and their efficacy and safety are assessed. This review broadens the perspective on specific aspects of using anti-inflammatory strategies for treating depression, laying the groundwork for advancing precision medicine for individuals suffering from "inflamed" depression.

Estimating the impact of metabolic syndrome on low back pain and the joint effects of metabolic syndrome and depressive symptoms on low back pain: insights from the China Health and Retirement Longitudinal Study

BACKGROUND

Although metabolic syndrome (MetS) and depressive symptoms (DS) are predictors of low back pain (LBP), their combined effects and relative contributions to LBP have not been well studied. Using the nationally representative data from the China Health and Retirement Longitudinal Study (CHARLS), this study conducted cross-sectional and longitudinal analyses to investigate the impact of MetS on LBP, and the joint effects of MetS and DS on LBP.

METHODS

This study included a cross-sectional analysis of 8957 participants aged at least 45 years from the CHARLS 2011 dataset and a longitudinal follow-up of 3468 participants without LBP from the CHARLS 2011, tracked over 9.25 years (from June 2011 to September 2020) with 4 times LBP assessment in CHARLS 2013, 2015, 2018, and 2020. To explore the association between MetS on LBP and the joint effects of MetS and DS on LBP, multivariable-adjusted multinomial logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Multivariable-adjusted COX proportional hazards regression models were applied to estimate hazard ratios (HRs) and 95% CIs. All statistical analyses were conducted using STATA (version SE16).

RESULTS

In the cross-sectional analysis, MetS was associated with a lower risk of LBP (adjusted OR = 0.85, 95% CI = 0.74-0.97), while there was no significance for this association in the longitudinal analysis. In the joint association of MetS and DS with LBP, participants with NoMetS + DS (adjusted OR = 2.31, 95% CI = 1.94-2.75), and MetS + DS (adjusted OR = 2.16, 95% CI = 1.81-2.59) were risk factors for LBP events, while those with MetS + NoDS (adjusted OR = 0.75, 95% CI = 0.62-0.90) was a protective factor for LBP events than those with NoMetS + NoDS. During the 9.25 years of follow-up, 1708 cases (49.25%) experienced incident LBP events. In the longitudinal analysis, a significantly negative association was not found in MetS + NoDS for LBP events. Three sensitivity analyses identified the robustness of the associations. Moreover, the nature of cross-sectional associations differed by age (45-64 and 65 + years).

CONCLUSIONS

Our study found that MetS was linked to a lower incidence of LBP, but this effect does not persist over time. Importantly, the combination of MetS and DS significantly increased LBP risk, a joint effect not extensively studied before. These findings underscore the novel contribution of our research, advocating for the joint assessment of MetS and DS to enhance LBP risk stratification and inform prevention strategies.

Systemic inflammation following traumatic injury and its impact on neuroinflammatory gene expression in the rodent brain

BACKGROUND

Trauma can result in systemic inflammation that leads to organ dysfunction, but the impact on the brain, particularly following extracranial insults, has been largely overlooked.

METHODS

Building upon our prior findings, we aimed to understand the impact of systemic inflammation on neuroinflammatory gene transcripts in eight brain regions in rats exposed to (1) blast overpressure exposure [BOP], (2) cutaneous thermal injury [BU], (3) complex extremity injury, 3 hours (h) of tourniquet-induced ischemia, and hind limb amputation [CEI+tI+HLA], (4) BOP+BU or (5) BOP+CEI and delayed HLA [BOP+CEI+dHLA] at 6, 24, and 168 h post-injury (hpi).

RESULTS

Globally, the number and magnitude of differentially expressed genes (DEGs) correlated with injury severity, systemic inflammation markers, and end-organ damage, driven by several chemokines/cytokines (Csf3, Cxcr2, Il16, and Tgfb2), neurosteroids/prostaglandins (Cyp19a1, Ptger2, and Ptger3), and markers of neurodegeneration (Gfap, Grin2b, and Homer1). Regional neuroinflammatory activity was least impacted following BOP. Non-blast trauma (in the BU and CEI+tI+HLA groups) contributed to an earlier, robust and diverse neuroinflammatory response across brain regions (up to 2-50-fold greater than that in the BOP group), while combined trauma (in the BOP+CEI+dHLA group) significantly advanced neuroinflammation in all regions except for the cerebellum. In contrast, BOP+BU resulted in differential activity of several critical neuroinflammatory-neurodegenerative markers compared to BU. t-SNE plots of DEGs demonstrated that the onset, extent, and duration of the inflammatory response are brain region dependent. Regardless of injury type, the thalamus and hypothalamus, which are critical for maintaining homeostasis, had the most DEGs. Our results indicate that neuroinflammation in all groups progressively increased or remained at peak levels over the study duration, while markers of end-organ dysfunction decreased or otherwise resolved.

CONCLUSIONS

Collectively, these findings emphasize the brain's sensitivity to mediators of systemic inflammation and provide an example of immune-brain crosstalk. Follow-on molecular and behavioral investigations are warranted to understand the short- to long-term pathophysiological consequences on the brain, particularly the mechanism of blood-brain barrier breakdown, immune cell penetration-activation, and microglial activation.

Viral infections in etiology of mental disorders: a broad analysis of cytokine profile similarities - a narrative review

The recent pandemic caused by the SARS-CoV-2 virus and the associated mental health complications have renewed scholarly interest in the relationship between viral infections and the development of mental illnesses, a topic that was extensively discussed in the previous century in the context of other viruses, such as influenza. The most probable and analyzable mechanism through which viruses influence the onset of mental illnesses is the inflammation they provoke. Both infections and mental illnesses share a common characteristic: an imbalance in inflammatory factors. In this study, we sought to analyze and compare cytokine profiles in individuals infected with viruses and those suffering from mental illnesses. The objective was to determine whether specific viral diseases can increase the risk of specific mental disorders and whether this risk can be predicted based on the cytokine profile of the viral disease. To this end, we reviewed existing literature, constructed cytokine profiles for various mental and viral diseases, and conducted comparative analyses. The collected data indicate that the risk of developing a specific mental illness cannot be determined solely based on cytokine profiles. However, it was observed that the combination of IL-8 and IL-10 is frequently associated with psychotic symptoms. Therefore, to assess the risk of mental disorders in infected patients, it is imperative to consider the type of virus, the mental complications commonly associated with it, the predominant cytokines to evaluate the risk of psychotic symptoms, and additional patient-specific risk factors.

Pulmonary neuroendocrine cells: crucial players in respiratory function and airway-nerve communication

Pulmonary neuroendocrine cells (PNECs) are unique airway epithelial cells that blend neuronal and endocrine functions, acting as key sensors in the lung. They respond to environmental stimuli like allergens by releasing neuropeptides and neurotransmitters. PNECs stand out as the only lung epithelial cells innervated by neurons, suggesting a significant role in airway-nerve communication via direct neural pathways and hormone release. Pathological conditions such as asthma are linked to increased PNECs counts and elevated calcitonin gene-related peptide (CGRP) production, which may affect neuroprotection and brain function. CGRP is also associated with neurodegenerative diseases, including Parkinson's and Alzheimer's, potentially due to its influence on inflammation and cholinergic activity. Despite their low numbers, PNECs are crucial for a wide range of functions, highlighting the importance of further research. Advances in technology for producing and culturing human PNECs enable the exploration of new mechanisms and cell-specific responses to targeted therapies for PNEC-focused treatments.

Potential Roles of Nr4a3-Mediated Inflammation in Immunological and Neurological Diseases

As a protein of the orphan nuclear receptor Nr4a family, Nr4a3 has no identified natural ligands. However, its biological activity can be mediated by inducing conformational changes through interactions with specific certain small molecules and receptors. Nr4a3 is activated as an early stress factor under various pathological conditions and plays a regulatory role in various tissues and cells, participating in processes such as cell differentiation, apoptosis, metabolism, and homeostasis. At present, research on the role of Nr4a3 in the pathophysiology of inflammation is considerably limited, especially with respect to its role in the central nervous system (CNS). In this review, we discuss the role of Nr4a3 in multiple sclerosis, Alzheimer's disease, retinopathy, Parkinson's disease, and other CNS diseases. This review shows that Nr4a3 has considerable potential as a therapeutic target in the treatment of CNS diseases. We provide a theoretical basis for the targeted therapy of CNS diseases and neuroinflammation, among other conditions.

Hospital-treated infectious diseases, infection burden and risk of Parkinson disease: An observational and Mendelian randomization study

BACKGROUND

Experimental and cross-sectional evidence has suggested a potential role of infection in the ethology of Parkinson's disease (PD). We aim to examine the longitudinal association of infections with the incidence of PD and to explore whether the increased risk is limited to specific infection type rather than infection burden.

METHODS

Based on the UK Biobank, hospital-treated infectious diseases and incident PD were ascertained through record linkage to national hospital inpatient registers. Infection burden was defined as the sum of the number of infection episodes over time and the number of co-occurring infections. The polygenic risk score (PRS) for PD was calculated. The genome-wide association studies (GWAS) used in two-sample Mendelian Randomization (MR) were obtained from observational cohort participants of mostly European ancestry.

RESULTS

Hospital-treated infectious diseases were associated with an increased risk of PD (adjusted HR [aHR] 1.35 [95 % CI 1.20-1.52]). This relationship persisted when analyzing new PD cases occurring more than 10 years post-infection (aHR 1.22 [95 % CI 1.04-1.43]). The greatest PD risk was observed in neurological/eye infection (aHR 1.72 [95 % CI 1.32-2.34]), with lower respiratory tract infection (aHR 1.43 [95 % CI 1.02-1.99]) ranked the second. A dose-response association was observed between infection burden and PD risk within each PD-PRS tertile (p-trend < 0.001). Multivariable MR showed that bacterial and viral infections increase the PD risk.

CONCLUSIONS

Both observational and genetic analysis suggested a causal association between infections and the risk of developing PD. A dose-response relationship between infection burden and incident PD was revealed.

Peripheral inflammation is associated with brain atrophy and cognitive decline linked to mild cognitive impairment and Alzheimer's disease

Inflammation is an important factor in Alzheimer's disease (AD). An NMR measurement in plasma, glycoprotein acetyls (GlycA), captures the overall level of protein production and glycosylation implicated in systemic inflammation. With its additional advantage of reducing biological variability, GlycA might be useful in monitoring the relationship between peripheral inflammation and brain changes relevant to AD. However, the associations between GlycA and these brain changes have not been fully evaluated. Here, we performed Spearman's correlation analyses to evaluate these associations cross-sectionally and determined whether GlycA can inform AD-relevant longitudinal measurements among participants in the Alzheimer's Disease Neuroimaging Initiative (n = 1506), with additional linear models and stratification analyses to evaluate the influences of sex or diagnosis status and confirm findings from Spearman's correlation analyses. We found that GlycA was elevated in AD patients compared to cognitively normal participants. GlycA correlated negatively with multiple concurrent regional brain volumes in females diagnosed with late mild cognitive impairment (LMCI) or AD. Baseline GlycA level was associated with executive function decline at 3-9 year follow-up in participants diagnosed with LMCI at baseline, with similar but not identical trends observed in the future decline of memory and entorhinal cortex volume. Results here indicated that GlycA is an inflammatory biomarker relevant to AD pathogenesis and that the stage of LMCI might be relevant to inflammation-related intervention.

Intersecting Pathways: The Role of Metabolic Dysregulation, Gastrointestinal Microbiome, and Inflammation in Acute Ischemic Stroke Pathogenesis and Outcomes

Acute ischemic stroke (AIS) remains a major cause of mortality and long-term disability worldwide, driven by complex and multifaceted etiological factors. Metabolic dysregulation, gastrointestinal microbiome alterations, and systemic inflammation are emerging as significant contributors to AIS pathogenesis. This review addresses the critical need to understand how these factors interact to influence AIS risk and outcomes. We aim to elucidate the roles of dysregulated adipokines in obesity, the impact of gut microbiota disruptions, and the neuroinflammatory cascade initiated by lipopolysaccharides (LPS) in AIS. Dysregulated adipokines in obesity exacerbate inflammatory responses, increasing AIS risk and severity. Disruptions in the gut microbiota and subsequent LPS-induced neuroinflammation further link systemic inflammation to AIS. Advances in neuroimaging and biomarker development have improved diagnostic precision. Here, we highlight the need for a multifaceted approach to AIS management, integrating metabolic, microbiota, and inflammatory insights. Potential therapeutic strategies targeting these pathways could significantly improve AIS prevention and treatment. Future research should focus on further elucidating these pathways and developing targeted interventions to mitigate the impacts of metabolic dysregulation, microbiome imbalances, and inflammation on AIS.

Novel Insights into Changes in Gene Expression within the Hypothalamus in Two Asthma Mouse Models: A Transcriptomic Lung-Brain Axis Study

Patients with asthma experience elevated rates of mental illness. However, the molecular links underlying such lung-brain crosstalk remain ambiguous. Hypothalamic dysfunction is observed in many psychiatric disorders, particularly those with an inflammatory component due to many hypothalamic regions being unprotected by the blood-brain barrier. To gain a better insight into such neuropsychiatric sequelae, this study investigated gene expression differences in the hypothalamus following lung inflammation (asthma) induction in mice, using RNA transcriptome profiling. BALB/c mice were challenged with either bacterial lipopolysaccharide (LPS, E. coli) or ovalbumin (OVA) allergens or saline control (n = 7 per group), and lung inflammation was confirmed via histological examination of postmortem lung tissue. The majority of the hypothalamus was micro-dissected, and total RNA was extracted for sequencing. Differential expression analysis identified 31 statistically significant single genes (false discovery rate FDR5%) altered in expression following LPS exposure compared to controls; however, none were significantly changed following OVA treatment, suggesting a milder hypothalamic response. When gene sets were examined, 48 were upregulated and 8 were downregulated in both asthma groups relative to controls. REACTOME enrichment analysis suggests these gene sets are involved in signal transduction metabolism, immune response and neuroplasticity. Interestingly, we identified five altered gene sets directly associated with neurotransmitter signaling. Intriguingly, many of these altered gene sets can influence mental health and or/neuroinflammation in humans. These findings help characterize the links between asthma-induced lung inflammation and the brain and may assist in identifying relevant pathways and therapeutic targets for future intervention.