The role of inflammasomes in vascular cognitive impairment

Scientific status analysis of exercise benefits for vascular cognitive impairment: Evidence of neuroinflammation

Vascular cognitive impairment (VCI) is a syndrome characterized by cognitive decline resulting from insufficient perfusion to the entire brain or specific brain regions. The lack of a clear understanding of the mechanisms linking cerebrovascular disease to cognitive impairment has impeded the development of targeted treatments for VCI. Increasing evidence indicates that exercise may offer significant benefits for patients with VCI. This study explores how neuroinflammatory mechanisms mediate the effects of exercise on VCI, focusing on the broader biological processes involved. Exercise plays a crucial role in mitigating vascular risk factors, reducing oxidative stress, and promoting neurogenesis. Furthermore, exercise influences neuroinflammatory mediators and central immune cells via various signaling pathways. Different types and intensities of exercise, including resistance and endurance training, have been shown to differentially modulate neuroinflammation during the progression of VCI. This paper summarizes the current mechanisms of action and proposes exercise interventions targeting neuroinflammatory pathways, along with biomarker studies, to enhance our understanding of VCI pathogenesis and inform clinical practice. A more in-depth understanding of the inflammatory mechanisms underlying VCI may facilitate the development of targeted therapeutic interventions.

Integrative Multiomics Profiling of Mouse Hippocampus Reveals Transcriptional Upregulation of Interferon-Stimulated Genes Through PU.1 Regulator in Microglial Activation Induced by Chronic Cerebral Hypoperfusion

Chronic cerebral hypoperfusion (CCH) is a significant factor that accelerates cognitive deterioration, yet the mechanisms of hippocampal microglial activation in this context remain unclear. Using an integrative multiomics approach, we investigated the transcriptional and epigenomic landscape of microglial activation in a mouse model of CCH induced by bilateral common carotid artery stenosis. Behavioral assessments revealed cognitive impairments, while neuropathological analysis confirmed hippocampal damage. Proteomic and transcriptomic profiling uncovered significant upregulation of stress and inflammatory pathways, particularly the interferon (IFN) signaling cascade. Epigenomic analysis identified regions of open chromatin, suggesting active transcriptional regulation driven by the transcription factor (TF) PU.1. ChIP-nexus analysis further confirmed that PU.1 directly modulates the expression of IFN-stimulated genes (ISGs), which are pivotal in regulating microglial activation. Our findings demonstrate that PU.1 serves as a key regulator of the IFN-driven microglial response during CCH, mediated by enhanced chromatin accessibility and transcriptional activation of ISGs. This study highlights the critical role of PU.1 in microglial-mediated neuroinflammation and offers potential therapeutic targets for mitigating hippocampal damage associated with chronic cerebral ischemia.

Farrerol alleviates cognitive impairments in chronic cerebral hypoperfusion via suppressing NLRP3 inflammasome-mediated pyroptosis

BACKGROUND

Chronic cerebral hypoperfusion (CCH) serves as a critical pathological mechanism that contributes to the development of vascular dementia (VaD). NLRP3 inflammasome activation is a pivotal factor in promoting cognitive decline in CCH. Farrerol, a dihydroflavonoid derived from Rhododendron and other Ericaceae species, possesses anti-inflammatory, antioxidant, and neuroprotective properties. However, its role in regulating pyroptosis triggered by the NLRP3 inflammasome in CCH remains unclear.

METHODS

A permanent CCH rat model was generated by occluding the bilateral common carotid arteries (BCCAO), and cellular models of sustained hypoxia were used to mimic CCH in vitro. Eight weeks post-surgery, rats received farrerol treatment. Behavioral tests were conducted after four weeks of treatment. Brain tissues were analyzed via histological staining, immunofluorescence, qRT-PCR, ELISA, and Western blot. The anti-pyroptosis effects and mechanisms of farrerol were also tested in BV2 cells and primary microglia subjected to hypoglycemia and hypoxia conditions.

RESULTS

Farrerol markedly alleviated cognitive impairments and neural damage caused by CCH. In CCH rats, farrerol suppressed the activation of the NLRP3 inflammasome, decreased the levels of IL-1β and IL-18, and reduced pyroptosis. The in vitro experiments also demonstrated that farrerol could reduce chronic hypoxia-induced pyroptosis by inhibiting the NLRP3 inflammasome pathway. The cellular study further showed that the beneficial effects of farrerol in CCH are via modulating the MAPK-NF-κB pathway.

CONCLUSION

Farrerol mitigates CCH-induced cognitive dysfunction by inhibiting NLRP3 inflammasome-associated pyroptosis via modulating the MAPK-NF-κB signaling cascade. These findings underscore the potential of farrerol as a therapeutic candidate for CCH.

Muscle-Derived Small Extracellular Vesicles Mediate Exercise-Induced Cognitive Protection in Chronic Cerebral Hypoperfusion

Physical exercise protects against cognitive impairment caused by chronic cerebral hypoperfusion (CCH). However, the mechanisms through which exercise sends signals from the periphery to the central nervous system remain incompletely understood. This study demonstrated that exercise promotes the secretion of muscle-derived small extracellular vesicles (sEVs), which facilitate interorgan communication between the muscle and the brain. Systematic delivery of muscle-derived sEVs enhances synaptic plasticity and alleviated cognitive impairment in CCH. Notably, miRNA sequencing reveal miR-17/20a-5p as key cargos in sEVs involved in the exercise-induced muscle-brain crosstalk. Muscle-derived sEVs are also identified as the primary source of swimming-induced miR-17/20a-5p in circulating sEVs. Mechanistically, miR-17/20a-5p binds to the DEP-domain containing mTOR-interacting protein (DEPTOR) and activates the mammalian target of rapamycin (mTOR) pathway in the hippocampus. Depletion of miR-17/20a-5p from muscle-derived sEVs impairs the exercise-induced enhancement of synaptic plasticity and cognitive function. Moreover, overexpression of DEPTOR in the hippocampus attenuates the cognitive benefits of exercise. Conversely, hippocampus-specific activation of mTOR reverses these effects, highlighting the crucial role of mTOR in mediating the positive effects of exercise. Collectively, these findings identify miR-17/20a-5p in muscle-derived sEVs as the exercise-induced myokine with potent effects on the brain, emphasizing the therapeutic potential of exercise in managing cognitive impairment.

Drug-targeted Mendelian randomization analysis combined with transcriptome sequencing to explore the molecular mechanisms associated with cognitive impairment

BackgroundCurrent therapies for cognitive impairment, including Alzheimer's disease (AD) and mild cognitive impairment, are limited by a lack of universal treatment and adverse effects associated with polypharmacy. Investigating genetic and molecular mechanisms underlying cognitive decline is critical for the development of targeted therapeutics.ObjectiveTo identify causal genes and potential therapeutic targets for cognitive impairment through integrative genomic analyses.MethodsGenome-wide association study data on cognitive impairment were combined with the expression quantitative trait loci (eQTL) data from the eQTLGen consortium. Mendelian randomization (MR) and colocalization analyses were employed to infer causal relationships. Gene Set Enrichment Analysis and Gene Set Variation Analysis evaluated the pathway and functional differences. Immune cell infiltration patterns and the immunometabolic pathways were assessed, followed by drug target prediction.ResultsMR analysis identified seven gene-eQTL pairs significantly associated with cognitive impairment. SMR colocalization prioritized three key genes: HNMT (histamine metabolism), TNFSF8 (inflammatory signaling), and S1PR5 (sphingolipid signaling). HNMT, TNFSF8, and S1PR5 had 39, 24, and 30 predicted targeted drugs, respectively, including arsenic trioxide, aspirin, and immunomodulators.ConclusionsThis study implicates HNMT, TNFSF8, and S1PR5 as potential therapeutic targets for cognitive impairment. Further validation is required to confirm their clinical relevance.

Neomycin affects cardiovascular and hematopoietic system via the PI3K/Akt pathway in zebrafish larvae

Neomycin, a widely used aminoglycoside antibiotic, poses potential risks to organism and the environment that remain incompletely evaluated. This study systematically evaluates its toxic effects on zebrafish embryos across physiological, cellular, molecular, and behavioral dimensions. At the physiological level, neomycin exposure induces severe developmental abnormalities, including yolk sac edema, reduced body length, and craniofacial malformations. Developmental disorders of the cardiovascular and hematopoietic systems are confirmed in exposed larvae. In addition, zebrafish larvae exposed to neomycin exhibit significant locomotor deficits, including reduced swimming speed, distance traveled, and impaired responsiveness to light-dark stimulation, indicating reduced activity. Mechanically, neomycin triggers oxidative stress through a dose-dependent elevation of reactive oxygen species (ROS) levels and induces cellular apoptosis through the PI3K/Akt signaling pathway. Collectively, our findings demonstrate that neomycin exerts toxic effects on zebrafish embryonic development, highlighting concerns regarding neomycin exposure risks during early pregnancy and providing critical insights into its potential environmental hazards.

The Role of Oxidative Stress and Inflammation in the Pathogenesis and Treatment of Vascular Dementia

Vascular dementia (VaD) is a heterogeneous group of brain disorders caused by cerebrovascular pathologies and the second most common cause of dementia, accounting for over 20% of cases and posing an important global health concern. VaD can be caused by cerebral infarction or injury in critical brain regions, including the speech area of the dominant hemisphere or arcuate fasciculus of the dominant hemisphere, leading to notable cognitive impairment. Although the exact causes of dementia remain multifactorial and complex, oxidative stress (reactive oxygen species), neuroinflammation (TNFα, IL-6, and IL-1β), and inflammasomes are considered central mechanisms in its pathology. These conditions contribute to neuronal damage, synaptic dysfunction, and cognitive decline. Thus, antioxidants and anti-inflammatory agents have emerged as potential therapeutic targets in dementia. Recent studies emphasize that cerebrovascular disease plays a dual role: first, as a primary cause of cognitive impairment and then as a contributor to the manifestation of dementia driven by other factors, such as Alzheimer's disease and other neurodegenerative conditions. This comprehensive review of VaD focuses on molecular mechanisms and their consequences. We provided up-to-date knowledge about epidemiology, pathophysiological mechanisms, and current therapeutic approaches for VaD.

Traditional Chinese medicine as a viable option for managing vascular cognitive impairment: A ray of hope

Vascular cognitive impairment (VCI) is a prevalent cognitive disorder resulting from cerebrovascular disease and encompasses a spectrum of cognitive deficits, ranging from mild impairment to vascular dementia (VD). VCI is responsible for a minimum of 20% to 40% of all cases of dementia, with its prevalence ranking second only to Alzheimer's disease on a global scale. The pathogenesis of VCI is complex and includes a lack of cholinergic nerve cells, inflammation, oxidative stress, alterations in the blood-brain barrier, and cell apoptosis. Current guideline-recommended drugs have unsatisfactory therapeutic effects. However, traditional Chinese medicine (TCM) has long been associated with treating dementia, and numerous studies regarding treating dementia with TCM have been conducted. The etiology and pathogenesis of VaD are linked to deficiencies in the spleen and kidney, as well as phlegm turbidity. Treatment involves benefiting the spleen and kidney, improving blood circulation, removing blood stasis, and dispelling phlegm. Moreover, TCM presents benefits such as few adverse effects, low cost, long-term use suitability, and preventive effects. This review outlines the pathogenesis of VCI in both modern medicine and TCM, examines traditional prescriptions and single-agent ingredients with their pharmacological effects, emphasizes TCM's unique features, and explores its multi-targeted approach to treating VCI.

Sinomenine alleviates neuroinflammation in chronic cerebral hypoperfusion by promoting M2 microglial polarization and inhibiting neuronal pyroptosis via exosomal miRNA-223-3p

Chronic cerebral hypoperfusion (CCH) is a major contributor to vascular dementia, with neuroinflammation playing a central role in its pathogenesis. Sinomenine (SINO), a natural alkaloid derived from traditional Chinese medicine, has shown significant anti-inflammatory and neuroprotective properties. However, its efficacy and mechanism of action in CCH remain unclear. In this study, we established a CCH rat model through bilateral common carotid artery occlusion and administered 10 mg/kg of SINO daily. Behavioral tests demonstrated that SINO significantly improved cognitive and memory functions in CCH rats. Histological analysis revealed that SINO effectively reduced neuroinflammation and damage in the hippocampal CA1, CA3, and DG regions. Mechanistically, SINO promoted microglial polarization from the M1 to M2 phenotype, markedly inhibiting the release of pro-inflammatory cytokines, including IL-1β, IL-6, and TNF-α. Further exploration of its neuroprotective mechanism showed that exosomes from SINO-treated microglia were enriched with miRNA-223-3p, which suppressed NLRP3-mediated pyroptosis in neurons. While our findings highlight the therapeutic potential of SINO, further studies are needed to validate its safety and efficacy in diverse populations and chronic settings. In summary, this study not only demonstrates SINO's regulatory effect on microglial polarization in CCH but also unveils a novel neuroprotective mechanism through exosomal miRNA-223-3p delivery, providing a solid theoretical foundation for SINO's potential as a treatment for CCH.

TIGAR alleviates cognitive impairment in rats with chronic cerebral hypoperfusion by suppressing oxidative stress and pyroptosis

BACKGROUND

It is postulated that oxidative stress and pyroptosis, which are induced by chronic cerebral hypoperfusion (CCH), contribute to the pathogenesis of vascular cognitive impairment (VCI). The protective role of TIGAR in neurologic illnesses has been the subject of extensive examination, yet its role in models of CCH-induced cognitive impairment remains unexplored. The objective of this study was to ascertain whether TIGAR is a neuroprotective agent in rats with CCH that reduces oxidative stress and pyroptosis.

METHODS

A CCH model was established in rats through the use of bilateral common carotid artery occlusion (BCCAO). The effects of TIGAR on cognitive function and anxiety-depressive behaviors in rats with CCH were examined. To this end, the Y-maze and open field tests were employed. Nissl and hematoxylin-eosin (H&E) staining were used to assess histologic changes in the CA1 area of the hippocampus. Hippocampal glutathione (GSH) activity, malondialdehyde (MDA) content, and NADPH/NADP+ ratio were measured using the WST-8 colorimetric method to assess oxidative stress. The expression of TIGAR and pyroptosis-related proteins was assessed by western blotting.

RESULTS

A model of CCH-induced cognitive impairment was successfully established. Four weeks after BCCAO, cerebral blood flow returned to normal in the rats, and cognitive impairment and anxiety-depression-like behavior developed. In rats with CCH, MDA levels increased, GSH activity and NADPH/NADP+ ratio decreased, and pyroptosis-related protein expression increased. The pathologic findings indicated that there was an exacerbation of neuronal injury in the CA1 area of the hippocampus and that the cells were loosely arranged. In rats with CCH, overexpression of TIGAR reduced pyroptosis-associated protein expression while increasing MDA content, GSH activity, and NADPH/NADP+ ratio. It promoted neuronal cell survival, and improved cognitive function and anxiety-depression-like behavior.

CONCLUSION

Overexpression of TIGAR reduced CCH-induced oxidative stress and pyroptosis and ameliorated cognitive dysfunction and anxiety-depression-like behavior in rats. These findings suggest that TIGAR counteracts oxidative stress and prevents pyroptosis, making it a promising target for the treatment of VCI.

Toll-Like Receptor 4-Mediated Neuroinflammation: Updates on Pathological Roles and Therapeutic Strategies in Chronic Cerebral Hypoperfusion

Neuroinflammation has been acknowledged as being one of the main pathologies that occur following chronic cerebral hypoperfusion (CCH). Since it significantly contributes to neuronal cell damage and thereby leads to cognitive impairment, the signals related to inflammation in hypoperfusion injury have been extensively investigated over the past few years. Toll-like receptor 4 (TLR4) is the key receptor responsible for immune and inflammatory reactions. It has been reported that TLR4 is involved in the pathology of several diseases and has emerged as a therapeutic target for developing a variety of anti-inflammatory compounds. This study explored the pathological roles of TLR4 that potentially cause the promotion of neuroinflammation in CCH damage. The evidence pertinent to the activation of TLR4 and its downstream inflammatory cascades following CCH are also summarized. This study also demonstrated the therapeutic potential of TLR4 inhibition, whether through drugs, substances, or other treatment strategies, in models of CCH-induced neurological dysfunction. The limitations of the accumulated evidence are addressed and discussed in this study. A deeper understanding of the roles of TLR4 in neuroinflammation following CCH damage may help inform the machinery behind pathological processes for advancing further neuroscientific research and developing therapeutic strategies for vascular dementia.

Molecular Imaging with PET in the Assessment of Vascular Dementia and Cerebrovascular Disease

Vascular dementia (VaD) is a unique form of cognitive decline caused by impairment of blood flow to the brain. Atherosclerosis is strongly associated with VaD as plaque accumulation can lead to tissue hypoperfusion or stroke. VaD and atherosclerosis are both diagnosed relatively late in their disease courses, prompting the need for novel diagnostic approaches such as PET to visualize subclinical pathophysiologic changes. This review discusses the use of PET in the assessment of VaD and cerebrovascular disease, focusing on the application of [18F] fluorodeoxyglucose to study neurometabolism and [18F] sodium fluoride to quantify arterial calcification.

Predictive value of nutritional status and serological indicators in elderly patients with mild cognitive impairment

BACKGROUND

Mild cognitive impairment (MCI) in elderly individuals is a transitional stage between normal cognition and dementia. Understanding the risk factors for MCI and identifying those at high risk are extremely important for the elderly population.

AIM

To analyze the risk factors for MCI in the elderly population and construct a clinical prediction model.

METHODS

Total 295 elderly individuals presenting with memory loss diagnosed at Wuxi People's Hospital between March 2021 and March 2024 were included. Comprehensive demographic, clinical, and serological data were collected for analysis. Participants were categorized into either an MCI group or a normal group based on their performance on the Montreal Cognitive Assessment Scale. An elaborate clinical predictive model was developed to predict the likelihood of MCI in stroke patients; its accuracy was evaluated using area under curve values and calibration curves.

RESULTS

The results of the study showed that old age, hypertension, diabetes, hyperlipidemia, smoking, high-salt diet, high-cholesterol diet, decreased red blood count, increased neutrophil lymphocyte ratio and increased low-density lipoprotein cholesterol were risk factors for the onset of MCI, with A high vitamin diet and elevated high-density lipoprotein cholesterol being protective factors. In addition, the prediction model constructed in this study exhibits good degrees of differentiation and calibration.

CONCLUSION

The risk factors for MCI are diverse. Early identification of individuals at high risk of MCI can better intervene and improve their quality of life of MCI patients.

Exploring the therapeutic implications of natural compounds modulating apoptosis in vascular dementia

Vascular dementia (VaD) is a prevalent form of dementia stemming from cerebrovascular disease, manifesting in memory impairment and executive dysfunction, thereby imposing a substantial societal burden. Unfortunately, no drugs have been approved for the treatment of VaD due to its intricate pathogenesis, and the development of innovative and efficacious medications is urgently needed. Apoptosis, a programmed cell death process crucial for eliminating damaged or unwanted cells within an organism, assumes pivotal roles in embryonic development and tissue homeostasis maintenance. An increasing body of evidence indicates that apoptosis may significantly influence the onset and progression of VaD, and numerous natural compounds have demonstrated significant therapeutic potential. Here, we discuss the molecular mechanisms underlying apoptosis and its correlation with VaD. We also provide a crucial reference for developing innovative pharmaceuticals by systematically reviewing the latest research progress concerning the neuroprotective effects of natural compounds on VaD by regulating apoptosis. Further high-quality clinical studies are imperative to firmly ascertain these natural compounds' clinical efficacy and safety profiles in the treatment of VaD.

Downregulation of Notch Signaling-Stimulated Genes in Neurovascular Unit Alterations Induced by Chronic Cerebral Hypoperfusion

BACKGROUND

Chronic cerebral hypoperfusion (CCH) is a key contributor to vascular cognitive impairment (VCI) and is typically associated with blood-brain barrier (BBB) damage. This study investigates the pathological mechanisms underlying CCH-induced neurovascular unit (NVU) alterations.

METHODS

A mouse model of CCH was established using the bilateral common carotid artery stenosis (BCAS) procedure. Decreased cerebral blood flow (CBF) and impaired BBB integrity were assessed. Brain microvessel (BMV)-specific transcriptome profiles were analyzed using RNA-seq, supplemented with published single-cell RNA-seq data.

RESULTS

RNA-seq revealed neuroinflammation-related gene activation and significant downregulation of Notch signaling pathway genes in BMVs post-BCAS. Upregulated differentially expressed genes (DEGs) were enriched in microglia/macrophages, while downregulated DEGs were prominent in endothelial cells and pericytes. Enhanced activation of vascular-associated microglia (VAM) was linked to neurovascular alterations.

CONCLUSION

CCH induces significant NVU changes, marked by microglia-associated neuroinflammation and Notch signaling downregulation. These insights highlight potential therapeutic targets for treating neuroinflammatory and vascular-related neurodegenerative diseases.

Association between fibrosis-4 index and cognitive impairment in elderly patients with hypertension: A cross-sectional study

The fibrosis-4 index (FIB-4) is a noninvasive fibrosis test that is recommended for patients who are at risk of developing hepatic fibrosis. The aim of the study was to explore the correlation between FIB-4 index and the decline of cognitive function among older patients with hypertension. The study used a cross-sectional design to analyze data obtained from the NHANES 2011-2014. The significance of the FIB-4 index correlation with cognitive function in individuals over the age of 60 was evaluated via multivariate regression models. The nonlinear link was described and fitted smoothed curves. There were a total of 2039 participants in the study, and those with a higher FIB-4 index were more susceptible to developing cognitive decline. In the completely adjusted model, the association remained statistically significant between the FIB-4 index and poor cognitive function as measured by CERAD: Total Score (OR = 0.72, 0.57-0.91), Animal Fluency Score (OR = 0.66, 0.48-0.91), and Digit Symbol Score (OR = 0.36, 0.17-0.77). A nonlinear association was found between the FIB-4 and poor cognitive ability: Total Score, CERAD: Score Delayed Recall, Digit Symbol Score, and Animal Fluency Score. In elderly patients with hypertension, a high FIB-4 index is correlated with an increased prevalence of cognitive decline. Hence, the FIB-4 index could potentially serve as a valuable tool for determining individuals with hypertension who are susceptible to both liver-related complications and cognitive impairment.

Theta-burst transcranial magnetic stimulation attenuates chronic ischemic demyelination and vascular cognitive impairment in mice

Vascular cognitive impairment and dementia (VCID) is mainly caused by chronic cerebral hypoperfusion and subsequent white matter lesions. Noninvasive transcranial magnetic stimulation has been utilized in treating various neurological disorders. However, the function of theta-burst transcranial magnetic stimulation on VCID remains to be defined. We utilized 4-week bilateral carotid artery stenosis model of male mice to mimic VCID. Intermittent theta-burst stimulation (iTBS) or consecutive theta-burst stimulation (cTBS) was administered for 14 consecutive days. Through luxol fast blue staining, electron microscopy and immunofluorescence, we found that iTBS, not cTBS, significantly improved demyelination, axonal damage and β-amyloid deposition, without affecting cerebral blood flow in VCID mice. At cellular levels, iTBS rescued the loss of mature oligodendrocytes, promoted precursor cell differentiation, and inhibited pro-inflammatory activation of astrocytes and microglia. Notably, iTBS attenuated cognitive deterioration in both short-term retention and long-term spatial memory of VCID mice as indicated by serial neurobehavioral tests. To explore the molecular involvement of iTBS, mRNA sequencing was carried out. By real-time PCR and combined RNA fluorescence in situ hybridization with immunofluorescence, iTBS was confirmed to increase Rxrg expression specifically in mature oligodendrocytes. Collectively, iTBS could ameliorate vascular cognitive dysfunction, probably via mitigating white matter lesions and neuroinflammation in the corpus callosum. Rxrg signaling in mature oligodendrocytes, which was increased by iTBS, might be a potential target for VCID treatment.

Single-cell RNA Sequencing Identifies a Novel Subtype of Microglia with High Cd74 Expression that Facilitates White Matter Inflammation During Chronic Cerebral Hypoperfusion

Vascular dementia (VaD) causes progressive cognitive decline in the elderly population, but there is short of available therapeutic measures. Microglia-mediated neuroinflammation is vigorously involved in the pathogenesis of VaD, but the traditional classification of microglial M1/M2 phenotypes remains restrictive and controversial. This study aims to investigate whether microglia transform into novel subtypes in VaD. Chronic cerebral hypoperfusion (CCH) rat model was constructed to mimic VaD. Microglia were isolated via magnetic-activated cell sorting and analyzed by single-cell RNA sequencing (scRNA-seq) and bioinformatics. The findings inferred from scRNA-seq and bioinformatics were further validated through in vivo experiments. In this study, microglia were divided into eight clusters. The proportion of MG5 cluster was significantly increased in the white matter of the CCH group compared with the Sham group and was named chronic ischemia-associated microglia (CIAM). Immunity- and inflammation-related genes, including RT1-Db1, RT1-Da, RT1-Ba, Cd74, Spp1, C3, and Cd68, were markedly upregulated in CIAM. Enrichment analysis illustrated that CIAM possessed the function of evoking neuroinflammation. Further studies unveiled that Cd74 is associated with the most abundant GO terms involved in inflammation as well as cell proliferation and differentiation. In addition, microglia-specific Cd74 knockdown mediated by adeno-associated virus decreased the abundance of CIAM in the white matter, thereby mitigating inflammatory cytokine levels, alleviating white matter lesions, and improving cognitive impairment for CCH rats. These findings indicate that Cd74 is the core molecule of CIAM to trigger neuroinflammation and induce microglial differentiation to CIAM, suggesting that Cd74 may be a potential therapeutic target for VaD.

Cytokine dysregulation in amnestic mild cognitive impairment

The pathophysiology of amnestic Mild Cognitive Impairment (aMCI) is largely unknown, although some papers found signs of immune activation. To assess the cytokine network in aMCI after excluding patients with major depression (MDD) and to examine the immune profiles of quantitative aMCI (qMCI) and distress symptoms of old age (DSOA) scores. A case-control study was conducted on 61 Thai aMCI participants and 60 healthy old adults (both without MDD). The Bio-Plex Pro human cytokine 27-plex test kit was used to assay cytokines/chemokines/growth factors in fasting plasma samples. aMCI is characterized by a significant immunosuppression, and reductions in T helper 1 (Th)1 and T cell growth profiles, the immune-inflammatory responses system, interleukin (IL)1β, IL6, IL7, IL12p70, IL13, GM-CSF, and MCP-1. These 7 cytokines/chemokines exhibit neuroprotective effects at physiologic concentrations. In multivariate analyses, three neurotoxic chemokines, CCL11, CCL5, and CXCL8, emerged as significant predictors of aMCI. Logistic regression showed that aMCI was best predicted by combining IL7, IL1β, MCP-1, years of education (all inversely associated) and CCL5 (positively associated). We found that 38.2% of the variance in the qMCI score was explained by IL7, IL1β, MCP-1, IL13, years of education (inversely associated) and CCL5 (positively associated). The DSOA was not associated with any immune data. An imbalance between lowered levels of neuroprotective cytokines and chemokines, and relative increases in neurotoxic chemokines are key factors in aMCI. Future MCI research should always control for the confounding effects of affective symptoms.

AMPA receptor potentiation alleviates NLRP3 knockout-induced fear generalization in mice

Genetic knockout and pharmaceutical inhibition of the NLRP3 inflammasome enhances the extinction of contextual fear memory, which is attributed to its role in neuronal and synaptic dysregulation, concurrent with neurotransmitter function disturbances. This study aimed to determine whether NLRP3 plays a role in generalizing fear via the inflammatory axis. We established the NLRP3 KO mice model, followed by behavioral and biochemical analyses. The NLRP3 KO mice displayed impaired fear generalization, lower neuroinflammation levels, and dysregulated neurotransmitter function. Additionally, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, but not the inhibition of NMDA or 5-HT2C receptors, resulted in fear generalization in NLRP3 KO mice because TAT-GluA2 3Y, but not SB242084 and D-cycloserine, treated blocked NLRP3 deprivation effects on fear generalization. Thus, global knockout of NLRP3 is associated with aberrant fear generalization, possibly through AMPA receptor signaling.

SIRT6 prevent chronic cerebral hypoperfusion induced cognitive impairment by remodeling mitochondrial dynamics in a STAT5-PGAM5-Drp1 dependent manner

Vascular dementia (VaD) is a prevalent form of dementia resulting from chronic cerebral hypoperfusion (CCH). However, the pathogenic mechanisms of VaD and corresponding therapeutic strategies are not well understood. Sirtuin 6 (SIRT6) has been implicated in various biological processes, including cellular metabolism, DNA repair, redox homeostasis, and aging. Nevertheless, its functional relevance in VaD remains unexplored. In this study, we utilized a bilateral common carotid artery stenosis (BCAS) mouse model of VaD to investigate the role of SIRT6. We detected a significant decrease in neuronal SIRT6 protein expression following CCH. Intriguingly, neuron-specific ablation of Sirt6 in mice exacerbated neuronal damage and cognitive deficits after CCH. Conversely, treatment with MDL-800, an agonist of SIRT6, effectively mitigated neuronal loss and facilitated neurological recovery. Mechanistically, SIRT6 inhibited excessive mitochondrial fission by suppressing the CCH-induced STAT5-PGAM5-Drp1 signaling cascade. Additionally, the gene expression of monocyte SIRT6 in patients with asymptomatic carotid stenosis showed a correlation with cognitive outcomes, suggesting translational implications in human subjects. Our findings provide the first evidence that SIRT6 prevents cognitive impairment induced by CCH, and mechanistically, this protection is achieved through the remodeling of mitochondrial dynamics in a STAT5-PGAM5-Drp1-dependent manner.

Vicious cycle of oxidative stress and neuroinflammation in pathophysiology of chronic vascular encephalopathy

Chronic vascular encephalopathy (CVE) is a frequent cause of vascular mild cognitive impairment and dementia, which significantly worsens the quality of life, especially in the elderly population. CVE is a result of chronic cerebral hypoperfusion, characterized by prolonged limited blood flow to the brain. This causes insufficient oxygenation of the brain leading to hypoxia. The latter can trigger a series of events associated with the development of oxidative/reductive stresses and neuroinflammation. Addressing the gap in knowledge regarding oxidative and reductive stresses in the development of vascular disorders and neuroinflammation can give a start to new directions of research in the context of CVE. In this review, we consider the hypoxia-induced molecular challenges involved in the pathophysiology of CVE, focusing on oxidative stress and neuroinflammation, which are combined in a vicious cycle of neurodegeneration. We also briefly describe therapeutic approaches to the treatment of CVE and outline the prospects for the use of sulforaphane, an isothiocyanate common in cruciferous plants, and vitamin D to break the vicious cycle and alleviate the cognitive impairments characteristic of patients with CVE.

Bruton's tyrosine kinase inhibition ameliorated neuroinflammation during chronic white matter ischemia

Chronic cerebral hypoperfusion (CCH), a disease afflicting numerous individuals worldwide, is a primary cause of cognitive deficits, the pathogenesis of which remains poorly understood. Bruton's tyrosine kinase inhibition (BTKi) is considered a promising strategy to regulate inflammatory responses within the brain, a crucial process that is assumed to drive ischemic demyelination progression. However, the potential role of BTKi in CCH has not been investigated so far. In the present study, we elucidated potential therapeutic roles of BTK in both in vitro hypoxia and in vivo ischemic demyelination model. We found that cerebral hypoperfusion induced white matter injury, cognitive impairments, microglial BTK activation, along with a series of microglia responses associated with inflammation, oxidative stress, mitochondrial dysfunction, and ferroptosis. Tolebrutinib treatment suppressed both the activation of microglia and microglial BTK expression. Meanwhile, microglia-related inflammation and ferroptosis processes were attenuated evidently, contributing to lower levels of disease severity. Taken together, BTKi ameliorated white matter injury and cognitive impairments induced by CCH, possibly via skewing microglia polarization towards anti-inflammatory and homeostatic phenotypes, as well as decreasing microglial oxidative stress damage and ferroptosis, which exhibits promising therapeutic potential in chronic cerebral hypoperfusion-induced demyelination.

Hydrogen Attenuates Cognitive Impairment in Rat Models of Vascular Dementia by Inhibiting Oxidative Stress and NLRP3 Inflammasome Activation

Vascular dementia (VaD) is the second most common form of dementia worldwide. Oxidative stress and neuroinflammation are important factors contributing to cognitive dysfunction in patients with VaD. The antioxidant and anti-inflammatory properties of hydrogen are increasingly being utilized in neurological disorders, but conventional hydrogen delivery has the disadvantage of inefficiency. Therefore, magnesium silicide nanosheets (MSNs) are used to release hydrogen in vivo in larger quantities and for longer periods of time to explore the appropriate dosage and regimen. In this study, it is observed that hydrogen improved learning and working memory in VaD rats in the Morris water maze and Y-maze, which elicits improved cognitive function. Nissl staining of neurons shows that hydrogen treatment significantly improves edema in neuronal cells. The expression and activation of reactive oxygen species (ROS), Thioredoxin-interacting protein (TXNIP), NOD-like receptor protein 3 (NLRP3), caspase-1, and IL-1β in the hippocampus are measured via ELISA, Western blotting, real-time qPCR, and immunofluorescence. The results show that oxidative stress indicators and inflammasome-related factors are significantly decreased after 7dMSN treatment. Therefore, it is concluded that hydrogen can ameliorate neurological damage and cognitive dysfunction in VaD rats by inhibiting ROS/NLRP3/IL-1β-related oxidative stress and inflammation.

Vagus Nerve Stimulation for Improvement of Vascular Cognitive Impairment

Vagus nerve stimulation (VNS) is acknowledged as a highly effective therapy for various neurological conditions, including refractory epilepsy, depression, Alzheimer's disease (AD), migraine, and stroke. Presently, there is an increasing focus on understanding the impact of VNS on cognitive aspects. Numerous studies suggest that VNS suppresses the body's inflammatory response, leading to enhanced cognitive function in patients. Vascular cognitive impairment (VCI) is a severe cognitive dysfunction syndrome resulting from prolonged chronic cerebral hypoperfusion (CCH), where the primary pathogenesis is CCH-induced neuroinflammation. In this paper, we present a comprehensive overview of the research advancements in using VNS for treating VCI and discuss that VNS improves cognitive function in VCI patients by suppressing neuroinflammation, offering insights into a potential novel approach for addressing this condition.

Astaxanthin Rescues Memory Impairments in Rats with Vascular Dementia by Protecting Against Neuronal Death in the Hippocampus

Vascular dementia (VaD) is a cognitive disorder characterized by a decline in cognitive function resulting from cerebrovascular disease. The hippocampus is particularly susceptible to ischemic insults, leading to memory deficits in VaD. Astaxanthin (AST) has shown potential therapeutic effects in neurodegenerative diseases. However, the mechanisms underlying its protective effects in VaD and against hippocampal neuronal death remain unclear. In this study, We used the bilateral common carotid artery occlusion (BCCAO) method to establish a chronic cerebral hypoperfusion (CCH) rat model of VaD and administered a gastric infusion of AST at 25 mg/kg per day for 4 weeks to explore its therapeutic effects. Memory impairments were assessed using Y-maze and Morris water maze tests. We also performed biochemical analyses to evaluate levels of hippocampal neuronal death and apoptosis-related proteins, as well as the impact of astaxanthin on the PI3K/Akt/mTOR pathway and oxidative stress. Our results demonstrated that AST significantly rescued memory impairments in VaD rats. Furthermore, astaxanthin treatment protected against hippocampal neuronal death and attenuated apoptosis. We also observed that AST modulated the PI3K/Akt/mTOR pathway, suggesting its involvement in promoting neuronal survival and synaptic plasticity. Additionally, AST exhibited antioxidant properties, mitigating oxidative stress in the hippocampus. These findings provide valuable insights into the potential therapeutic effects of AST in VaD. By elucidating the mechanisms underlying the actions of AST, this study highlights the importance of protecting hippocampal neurons and suggests potential targets for intervention in VaD. There are still some unanswered questions include long-term effects and optimal dosage of the use in human. Further research is warranted to fully understand the therapeutic potential of AST and its application in the clinical treatment of VaD.

Intermittent Metabolic Switching and Vascular Cognitive Impairment

Intermittent fasting (IF), a dietary pattern alternating between eating and fasting periods within a 24-hour cycle, has garnered recognition for its potential to enhance both healthspan and lifespan in animal models and humans. It also shows promise in alleviating age-related diseases, including neurodegeneration. Vascular cognitive impairment (VCI) spans a severity range from mild cognitive deficits to severe cognitive deficits and loss of function in vascular dementia. Chronic cerebral hypoperfusion has emerged as a significant contributor to VCI, instigating vascular pathologies such as microbleeds, blood-brain barrier dysfunction, neuronal loss, and white matter lesions. Preclinical studies in rodents strongly suggest that IF has the potential to attenuate pathological mechanisms, including excitotoxicity, oxidative stress, inflammation, and cell death pathways in VCI models. Hence, this supports evaluating IF in clinical trials for both existing and at-risk VCI patients. This review compiles existing data supporting IF's potential in treating VCI-related vascular and neuronal pathologies, emphasizing the mechanisms by which IF may mitigate these issues. Hence providing a comprehensive overview of the available data supporting IF's potential in treating VCI by emphasizing the underlying mechanisms that make IF a promising intervention for VCI.

Neferine inhibits BMECs pyroptosis and maintains blood-brain barrier integrity in ischemic stroke by triggering a cascade reaction of PGC-1α

Blood-brain barrier disruption is a critical pathological event in the progression of ischemic stroke (IS). Most studies regarding the therapeutic potential of neferine (Nef) on IS have focused on neuroprotective effect. However, whether Nef attenuates BBB disruption during IS is unclear. We here used mice underwent transient middle cerebral artery occlusion (tMCAO) in vivo and bEnd.3 cells exposed to oxygen-glucose deprivation/reoxygenation (OGD/R) injury in vitro to simulate cerebral ischemia. We showed that Nef reduced neurobehavioral dysfunction and protected brain microvascular endothelial cells and BBB integrity. Molecular docking, short interfering (Si) RNA and plasmid transfection results showed us that PGC-1α was the most binding affinity of biological activity protein for Nef. And verification experiments were showed that Nef upregulated PGC-1α expression to reduce mitochondrial oxidative stress and promote TJ proteins expression, further improves the integrity of BBB in mice. Intriguingly, our study showed that neferine is a natural PGC-1α activator and illustrated the mechanism of specific binding site. Furthermore, we have demonstrated Nef reduced mitochondria oxidative damage and ameliorates endothelial inflammation by inhibiting pyroptosis to improve BBB permeability through triggering a cascade reaction of PGC-1α via regulation of PGC-1α/NLRP3/GSDMD signaling pathway to maintain the integrity of BBB in ischemia/reperfusion injury.

The regulatory effect of intermittent fasting on inflammasome activation in health and disease

Intermittent fasting (IF), one of the most popular diets, can regulate inflammation and promote health; however, the detailed molecular mechanisms are not fully understood. The present review aims to provide an overview of recent preclinical and clinical studies that have examined the effect of IF on inflammasome signaling, and to discuss the translational gap between preclinical and clinical studies. Three databases (PubMed, Web of Science, and Embase) were searched to identify all relevant preclinical and clinical studies up to October 30, 2022. A total of 1544 studies were identified through the database searches, and 29 preclinical and 10 clinical studies were included. Twenty-three of the 29 preclinical studies reported that IF treatment could reduce inflammasome activation in neurological diseases, metabolic and cardiovascular diseases, immune and inflammatory diseases, gastrointestinal diseases, and pulmonary diseases, and 7 of the 10 clinical studies demonstrated reduced inflammasome activation after IF intervention in both healthy and obese participants. Among various IF regimens, time-restricted eating seemed to be the most effective one in terms of inflammasome regulation, and the efficacy of IF might increase over time. This review highlights the regulatory effect of IF on inflammasome activation in health and disease. Future studies using different IF regimens, in various populations, are needed in order to evaluate its potential to be used alone or as an adjunct therapy in humans to improve health and counteract diseases.

Increased Expression of VCAM1 on Brain Endothelial Cells Drives Blood-Brain Barrier Impairment Following Chronic Cerebral Hypoperfusion

Chronic cerebral hypoperfusion (CCH)-triggered blood-brain barrier (BBB) dysfunction is a core pathological change occurring in vascular dementia (VD). Despite the recent advances in the exploration of the structural basis of BBB impairment and the routes of entry of harmful compounds after a BBB leakage, the molecular mechanisms inducing BBB impairment remain largely unknown in terms of VD. Here, we employed a CCH-induced VD model and discovered increased vascular cell adhesion molecule 1 (VCAM1) expression on the brain endothelial cells (ECs). The expression of VCAM1 was directly correlated with the severity of BBB impairment. Moreover, the VCAM1 expression was associated with different regional white matter lesions. Furthermore, a compound that could block VCAM1 activation, K-7174, was also found to alleviate BBB leakage and protect the white matter integrity, whereas pharmacological manipulation of the BBB leakage did not affect the VCAM1 expression. Thus, our results demonstrated that VCAM1 is an important regulator that leads to BBB dysfunction following CCH. Blocking VCAM1-mediated BBB impairment may thus offer a new strategy to treat CCH-related neurodegenerative diseases.

Integration of metabolomics and transcriptomics reveals that Da Chuanxiong Formula improves vascular cognitive impairment via ACSL4/GPX4 mediated ferroptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Da Chuanxiong Formula (DCX) is a traditional herbal compound composed of Gastrodia elata Bl. and Ligusticum chuanxiong Hort, which could significantly enhance blood circulation and neuroprotection, showing promise in treating Vascular Cognitive Impairment (VCI).

AIM OF STUDY

This study aims to elucidate the potential of DCX in treating VCI and its underlying mechanism.

MATERIALS AND METHODS

Firstly, the cognitive behavior level, blood flow changes, and brain pathology changes were evaluated through techniques such as the Morris water maze, step-down, laser speckle, coagulation analysis, and pathological staining to appraise the DCX efficacy. Then, the DCX targeting pathways were decoded by merging metabolomics with transcriptomics. Finally, the levels of reactive oxygen species (ROS), Fe2+, and lipid peroxidation related to the targeting signaling pathways of DCX were detected by kit, and the expression levels of mRNAs or proteins related to ferroptosis were determined by qPCR or Western blot assays respectively.

RESULTS

DCX improved cognitive abilities and cerebral perfusion significantly, and mitigated pathological damage in the hippocampal region of VCI model rats. Metabolomics revealed that DCX was able to call back 33 metabolites in plasma and 32 metabolites in brain samples, and the majority of the differential metabolites are phospholipid metabolites. Transcriptomic analysis revealed that DCX regulated a total of 3081 genes, with the ferroptosis pathway exhibiting the greatest impact. DCX inhibited ferroptosis of VCI rates by decreasing the levels of ferrous iron, ROS, and malondialdehyde (MDA) while increasing the level of superoxide dismutase (SOD) and glutathione (GSH) in VCI rats. Moreover, the mRNA and protein levels of ACSL4, LPCAT3, ALOX15, and GPX4, which are related to lipid metabolism in ferroptosis, were also regulated by DCX.

CONCLUSION

Our research findings indicated that DCX could inhibit ferroptosis through the ACSL4/GPX4 signaling pathway, thereby exerting its therapeutic benefits on VCI.

Inhibition of piezo1 prevents chronic cerebral hypoperfusion-induced cognitive impairment and blood brain barrier disruption

Chronic cerebral hypoperfusion (CCH) plays a critical role in the onset and progression of vascular dementia (VD), which is now recognized as the second most common form of dementia after Alzheimer's disease (AD). The mechanosensitive piezo1 channel has been identified to play important roles in several neurological disorders. However, the roles and possible mechanisms of piezo1 in CCH-induced cognitive decline and blood brain barrier (BBB) disruption, as well as the underlying mechanisms remain elusive. In this study, the CCH model was established by bilateral common carotid artery occlusion in rats and by oxygen and glucose deprivation/reoxygenation (OGD/R) in bEnd.3 cells. The results demonstrated that the antagonist of piezo1 GsMTx4 ameliorated CCH-induced cognitive dysfunction and mitigated cerebral edema. Furthermore, this study indicated that GsMTx4 improved the permeability and integrity of BBB and protected cerebral microvasculature after CCH. In vitro, GsMTx4 improved cell viability, promoted the ability of cell motility and migration, and inhibited the degradation of BBB integrity-related proteins by inhibiting NLRP3 inflammasome activation. In addition, NLRP3 agonist abolished the beneficial effects of GsMTx4. Collectively, our results demonstrate that piezo1 might be involved in CCH-induced cognitive impairment and BBB damage, which may be at least partially mediated through regulation of NLRP3 inflammasome.

Chuanzhitongluo capsule improves cognitive impairment in mice with chronic cerebral hypoperfusion via the cholinergic anti-inflammatory pathway

Vascular cognitive impairment (VCI) has become a common disease-causing cognitive deficit in humans, second only to Alzheimer's Disease (AD). Chuanzhitongluo capsule (CZTL) is a Traditional Chinese Medicine (TCM) preparation known for its effective protection against cerebral ischemia. However, its potential to ameliorate VCI remains unclear. This study aimed to investigate the cognitive improvement effects of CZTL in a mouse model of VCI. Chronic cerebral hypoperfusion (CCH) was induced in mice by bilateral common carotid artery stenosis (BCAS) to simulate the pathological changes associated with VCI. Spatial learning and memory abilities were assessed using the Morris Water Maze (MWM). RNA sequencing (RNA-Seq) was employed to identify differentially expressed genes (DEGs) in the hippocampus. Levels of inflammatory factors were measured through enzyme-linked immunosorbent assay (ELISA), while immunofluorescence (IF) determined the expression intensity of target proteins. Western Blot (WB) confirmed the final action pathway. Results indicated that CZTL significantly improved the spatial learning and memory abilities of CCH mice, along with alterations in gene expression profiles in the hippocampus. It also reduced neuroinflammation in the hippocampus and upregulated the choline acetyltransferase (ChAT) and α7 subunit-containing nicotinic acetylcholine receptor (α7nAChR), which are in synaptic plasticity and neuronal development. Moreover, CZTL inhibited the NF-κB signaling pathway. In conclusion, CZTL may alleviate neuroinflammation induced by CCH and improve cognitive impairment in CCH mice by regulating the cholinergic anti-inflammatory pathway (CAIP) involving ChAT/α7nAChR/NF-κB.

Hope for vascular cognitive impairment: Ac-YVAD-cmk as a novel treatment against white matter rarefaction

Vascular cognitive impairment (VCI) is the second leading cause of dementia with limited treatment options, characterised by cerebral hypoperfusion-induced white matter rarefaction (WMR). Subcortical VCI is the most common form of VCI, but the underlying reasons for region susceptibility remain elusive. Recent studies employing the bilateral cortical artery stenosis (BCAS) method demonstrate that various inflammasomes regulate white matter injury and blood-brain barrier dysfunction but whether caspase-1 inhibition will be beneficial remains unclear. To address this, we performed BCAS on C57/BL6 mice to study the effects of Ac-YVAD-cmk, a caspase-1 inhibitor, on the subcortical and cortical regions. Cerebral blood flow (CBF), WMR, neuroinflammation and the expression of tight junction-related proteins associated with blood-brain barrier integrity were assessed 15 days post BCAS. We observed that Ac-YVAD-cmk restored CBF, attenuated BCAS-induced WMR and restored subcortical myelin expression. Within the subcortical region, BCAS activated the NLRP3/caspase-1/interleukin-1beta axis only within the subcortical region, which was attenuated by Ac-YVAD-cmk. Although we observed that BCAS induced significant increases in VCAM-1 expression in both brain regions that were attenuated with Ac-YVAD-cmk, only ZO-1 and occludin were observed to be significantly altered in the subcortical region. Here we show that caspase-1 may contribute to subcortical regional susceptibility in a mouse model of VCI. In addition, our results support further investigations into the potential of Ac-YVAD-cmk as a novel treatment strategy against subcortical VCI and other conditions exhibiting cerebral hypoperfusion-induced WMR.

Ion transporter cascade, reactive astrogliosis and cerebrovascular diseases

Cerebrovascular diseases and their sequalae, such as ischemic stroke, chronic cerebral hypoperfusion, and vascular dementia are significant contributors to adult disability and cognitive impairment in the modern world. Astrocytes are an integral part of the neurovascular unit in the CNS and play a pivotal role in CNS homeostasis, including ionic and pH balance, neurotransmission, cerebral blood flow, and metabolism. Astrocytes respond to cerebral insults, inflammation, and diseases through unique molecular, morphological, and functional changes, collectively known as reactive astrogliosis. The function of reactive astrocytes has been a subject of debate. Initially, astrocytes were thought to primarily play a supportive role in maintaining the structure and function of the nervous system. However, recent studies suggest that reactive astrocytes may have both beneficial and detrimental effects. For example, in chronic cerebral hypoperfusion, reactive astrocytes can cause oligodendrocyte death and demyelination. In this review, we will summarize the (1) roles of ion transporter cascade in reactive astrogliosis, (2) role of reactive astrocytes in vascular dementia and related dementias, and (3) potential therapeutic approaches for dementing disorders targeting reactive astrocytes. Understanding the relationship between ion transporter cascade, reactive astrogliosis, and cerebrovascular diseases may reveal mechanisms and targets for the development of therapies for brain diseases associated with reactive astrogliosis.

Association of plasma GFAP with elevated brain amyloid is dependent on severity of white matter lesions in an Asian cognitively impaired cohort

INTRODUCTION

While elevated blood glial fibrillary acidic protein (GFAP) has been associated with brain amyloid pathology, whether this association occurs in populations with high cerebral small vessel disease (CSVD) concomitance remains unclear.

METHODS

Using a Singapore-based cohort of cognitively impaired subjects, we assessed associations between plasma GFAP and neuroimaging measures of brain amyloid and CSVD, including white matter hyperintensities (WMH). We also examined the diagnostic performance of plasma GFAP in detecting brain amyloid beta positivity (Aβ+).

RESULTS

When stratified by WMH status, elevated brain amyloid was associated with higher plasma GFAP only in the WMH- group (β = 0.383; P < 0.001). The diagnostic performance of plasma GFAP in identifying Aβ+ was significantly higher in the WMH- group (area under the curve [AUC] = 0.896) than in the WMH+ group (AUC = 0.712, P = 0.008).

DISCUSSION

The biomarker utility of plasma GFAP in detecting brain amyloid pathology is dependent on the severity of concomitant WMH.

Highlight

Glial fibrillary acidic protein (GFAP)'s association with brain amyloid is unclear in populations with high cerebral small vessel disease (CSVD).Plasma GFAP was measured in a cohort with CSVD and brain amyloid.Plasma GFAP was better in detecting amyloid in patients with low CSVD versus high CSVD.Biomarker utility of GFAP in detecting brain amyloid depends on the severity of CSVD.

Hexahydrocurcumin attenuated demyelination and improved cognitive impairment in chronic cerebral hypoperfusion rats

Age-related white matter lesions (WML) frequently present vascular problems by decreasing cerebral blood supply, resulting in the condition known as chronic cerebral hypoperfusion (CCH). This study aimed to investigate the effect of hexahydrocurcumin (HHC) on the processes of demyelination and remyelination induced by the model of the Bilateral Common Carotid Artery Occlusion (BCCAO) for 29 days to mimic the CCH condition. The pathological appearance of myelin integrity was significantly altered by CCH, as evidenced by Transmission Electron Microscopy (TEM) and Luxol Fast Blue (LFB) staining. In addition, CCH activated A1-astrocytes and reactive-microglia by increasing the expression of Glial fibrillary acidic protein (GFAP), complement 3 (C3d) and pro-inflammatory cytokines. However, S100a10 expression, a marker of neuroprotective astrocytes, was suppressed, as were regenerative factors including (IGF-1) and Transglutaminase 2 (TGM2). Therefore, the maturation step was obstructed as shown by decreases in the levels of myelin basic protein (MBP) and the proteins related with lipid synthesis. Cognitive function was therefore impaired in the CCH model, as evidenced by the Morris water maze test. By contrast, HHC treatment significantly improved myelin integrity, and inhibited A1-astrocytes and reactive-microglial activity. Consequently, pro-inflammatory cytokines and A1-astrocytes were attenuated, and regenerative factors increased assisting myelin maturation and hence improving cognitive performance. In conclusion, HHC improves cognitive function and also the integrity of white matter in CCH rats by reducing demyelination, and pro-inflammatory cytokine production and promoting the process of remyelination.

P2X7 receptor antagonists modulate experimental autoimmune neuritis via regulation of NLRP3 inflammasome activation and Th17 and Th1 cell differentiation

BACKGROUND

Guillain-Barré syndrome (GBS), a post-infectious, immune-mediated, acute demyelinating disease of the peripheral nerves and nerve roots, represents the most prevalent and severe acute paralyzing neuropathy. Purinergic P2X7 receptors (P2X7R) play a crucial role in central nervous system inflammation. However, little is known about their role in the immune-inflammatory response within the peripheral nervous system.

METHODS

Initially, we assessed the expression of purinergic P2X7R in the peripheral blood of patients with GBS using flow cytometry and qRT-PCR. Next, we explored the expression of P2 X7R in CD4+ T cells, CD8+ T cells, and macrophages within the sciatic nerves and spleens of rats using immunofluorescence labeling and flow cytometry. The P2X7R antagonist brilliant blue G (BBG) was employed to examine its therapeutic impact on rats with experimental autoimmune neuritis (EAN) induced by immunization with the P0180 - 199 peptide. We analyzed CD4+ T cell differentiation in splenic mononuclear cells using flow cytometry, assessed Th17 cell differentiation in the sciatic nerve through immunofluorescence staining, and examined the expression of pro-inflammatory cytokine mRNA using RT-PCR. Additionally, we performed protein blotting to assess the expression of P2X7R and NLRP3-related inflammatory proteins within the sciatic nerve. Lastly, we utilized flow cytometry and immunofluorescence labeling to examine the expression of NLRP3 on CD4+ T cells in rats with EAN.

RESULTS

P2X7R expression was elevated not only in the peripheral blood of patients with GBS but also in rats with EAN. In rats with EAN, inhibiting P2X7R with BBG alleviated neurological symptoms, reduced demyelination, decreased inflammatory cell infiltration of the peripheral nerves, and improved nerve conduction. BBG also limited the production of pro-inflammatory molecules, down-regulated the expression of P2X7R and NLRP3, and suppressed the differentiation of Th1 and Th17 cells, thus protecting against EAN. These effects collectively contribute to modifying the inflammatory environment and enhancing outcomes in EAN rats.

CONCLUSIONS

Suppression of P2X7R relieved EAN manifestation by regulating CD4+ T cell differentiation and NLRP3 inflammasome activation. This finding underscores the potential significance of P2X7R as a target for anti-inflammatory treatments, advancing research and management of GBS.

Serum autophagy-related gene 5 level in stroke patients: correlation with CD4+ T cells and cognition impairment during a 3-year follow-up

Autophagy-related gene (ATG) 5 regulates blood lipids, chronic inflammation, CD4+ T-cell differentiation, and neuronal death and is involved in post-stroke cognitive impairment. This study aimed to explore the correlation of serum ATG5 with CD4+ T cells and cognition impairment in stroke patients. Peripheral blood was collected from 180 stroke patients for serum ATG5 and T helper (Th) 1, Th2, Th17, and regulatory T (Treg) cell detection via enzyme-linked immunosorbent assays and flow cytometry. The Mini-Mental State Examination (MMSE) scale was completed at enrollment, year (Y)1, Y2, and Y3 in stroke patients. Serum ATG5 was also measured in 50 healthy controls (HCs). Serum ATG5 was elevated in stroke patients compared to HCs (P<0.001) and was positively correlated to Th2 cells (P=0.022), Th17 cells (P<0.001), and Th17/Treg ratio (P<0.001) in stroke patients but not correlated with Th1 cells, Th1/Th2 ratio, or Treg cells (all P>0.050). Serum ATG5 (P=0.037), Th1 cells (P=0.022), Th17 cells (P=0.002), and Th17/Treg ratio (P=0.018) were elevated in stroke patients with MMSE score-identified cognition impairment vs those without cognition impairment, whereas Th2 cells, Th1/Th2 ratio, and Treg cells were not different between them (all P>0.050). Importantly, serum ATG5 was negatively linked with MMSE score at enrollment (P=0.004), Y1 (P=0.002), Y2 (P=0.014), and Y3 (P=0.001); moreover, it was positively related to 2-year (P=0.024) and 3-year (P=0.012) MMSE score decline in stroke patients. Serum ATG5 was positively correlated with Th2 and Th17 cells and estimated cognitive function decline in stroke patients.

Serum Proteomics Identified TAFI as a Potential Molecule Facilitating the Migration of Peripheral Monocytes to Damaged White Matter During Chronic Cerebral Hypoperfusion

Neuroinflammation is assumed as the critical pathophysiologic mechanism of white matter lesions (WMLs), and infiltrated peripheral monocyte-derived macrophages are implicated in the development of neuroinflammation. This study sought to explore the blood molecules that promote the migration of peripheral monocytes to the sites of WMLs. The serum protein expression profiles of patients and Sprague-Dawley rat models with WMLs were detected by data-independent acquisition (DIA) proteomics technique. Compared with corresponding control groups, we acquired 62 and 41 differentially expressed proteins (DEPs) in the serum of patients and model rats with WMLs respectively. Bioinformatics investigations demonstrated that these DEPs were linked to various Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways and Gene Ontology (GO) terms involved in neuroinflammation. Afterward, we identified thrombin-activatable fibrinolysis inhibitor (TAFI) as a shared and overexpressed protein in clinical and animal serum samples, which was further verified by enzyme-linked immunosorbent assay. Additionally, an upregulation of TAFI was also observed in the white matter of rat models, and the inhibition of TAFI impeded the migration of peripheral monocytes to the area of WMLs. In vitro experiments suggested that TAFI could enhance the migration ability of RAW264.7 cells and increase the expression of Ccr2. Our study demonstrates that neuroinflammatory signals can be detected in the peripheral blood of WMLs patients and model rats. TAFI may serve as a potential protein that promotes the migration of peripheral monocytes to WMLs regions, thereby providing a novel molecular target for further investigation into the interaction between the central and peripheral immune systems.

The Impact of Dipyridamole on Disease-Associated Microglia Phenotypic Transformation in White Matter Lesions Induced by Chronic Cerebral Hypoperfusion

White matter lesions (WMLs) resulting from chronic cerebral hypoperfusion (CCH) are the leading cause of vascular dementia (VaD). This study aimed to investigate whether dipyridamole could alleviate WMLs by regulating the phenotype of disease-associated microglia (DAM) through equilibrative nucleoside transporter 2 (ENT2) and adenosine A2A receptor (Adora2a) and to clarify the underlying molecular mechanisms. CCH rat models were constructed to mimic VaD. Morris water maze and Luxol Fast Blue staining were employed to assess cognitive function and quantify the severity of WMLs, respectively. Immunofluorescent staining was performed to analyze the activation of glial cells and the phenotypic transformation of DAM. Additionally, levels of ENT2, proteins in the NF-κB and ERK1/2 pathways and inflammatory cytokines were detected. The results indicated that dipyridamole diminished the activation and proliferation of microglia and astrocytes, increased the expression of myelin basic protein and ameliorated WMLs and cognitive decline in CCH rats. Further study revealed that dipyridamole decreased the expression of ENT2 and inhibited the activation of ERK1/2 and NF-κB signaling pathways, which ultimately converted DAM to anti-inflammatory phenotype and suppressed the levels of TNF-α, IL-1β, IL-6 in WMLs. However, Adora2a inhibitor (SCH58261) attenuated above effects. Our study demonstrates that dipyridamole facilitates the conversion of DAM to the anti-inflammatory phenotype through ENT2/Adora2a pathway and inhibits the activation of ERK1/2 and NF-κB signaling pathways, thereby alleviating neuroinflammation in WMLs. The current findings establish the basis for using dipyridamole to treat VaD.

Associations between vascular health, brain stiffness and global cognitive function

Vascular brain injury results in loss of structural and functional connectivity and leads to cognitive impairment. Its various manifestations, including microinfarcts, microhaemorrhages and white matter hyperintensities, result in microstructural tissue integrity loss and secondary neurodegeneration. Among these, tissue microstructural alteration is a relatively early event compared with atrophy along the aging and neurodegeneration continuum. Understanding its association with cognition may provide the opportunity to further elucidate the relationship between vascular health and clinical outcomes. Magnetic resonance elastography offers a non-invasive approach to evaluate tissue mechanical properties, providing a window into the microstructural integrity of the brain. This retrospective study evaluated brain stiffness as a potential biomarker for vascular brain injury and its role in mediating the impact of vascular dysfunction on cognitive impairment. Seventy-five participants from the Mayo Clinic Study of Aging underwent brain imaging using a 3T MR imager with a spin-echo echo-planar imaging sequence for magnetic resonance elastography and T1- and T2-weighted pulse sequences. This study evaluated the effects of vascular biomarkers (white matter hyperintensities and cardiometabolic condition score) on brain stiffness using voxelwise analysis. Partial correlation analysis explored associations between brain stiffness, white matter hyperintensities, cardiometabolic condition and global cognition. Mediation analysis determined the role of stiffness in mediating the relationship between vascular biomarkers and cognitive performance. Statistical significance was set at P-values < 0.05. Diagnostic accuracy of magnetic resonance elastography stiffness for white matter hyperintensities and cardiometabolic condition was evaluated using receiver operator characteristic curves. Voxelwise linear regression analysis indicated white matter hyperintensities negatively correlate with brain stiffness, specifically in periventricular regions with high white matter hyperintensity levels. A negative association between cardiovascular risk factors and stiffness was also observed across the brain. No significant patterns of stiffness changes were associated with amyloid load. Global stiffness (µ) negatively correlated with both white matter hyperintensities and cardiometabolic condition when all other covariables including amyloid load were controlled. The positive correlation between white matter hyperintensities and cardiometabolic condition weakened and became statistically insignificant when controlling for other covariables. Brain stiffness and global cognition were positively correlated, maintaining statistical significance after adjusting for all covariables. These findings suggest mechanical alterations are associated with cognitive dysfunction and vascular brain injury. Brain stiffness significantly mediated the indirect effects of white matter hyperintensities and cardiometabolic condition on global cognition. Local cerebrovascular diseases (assessed by white matter hyperintensities) and systemic vascular risk factors (assessed by cardiometabolic condition) impact brain stiffness with spatially and statistically distinct effects. Global brain stiffness is a significant mediator between vascular disease measures and cognitive function, highlighting the value of magnetic resonance elastography-based mechanical assessments in understanding this relationship.

Shared Proteins and Pathways of Cardiovascular and Cognitive Diseases: Relation to Vascular Cognitive Impairment

One of the primary goals of systems medicine is the detection of putative proteins and pathways involved in disease progression and pathological phenotypes. Vascular cognitive impairment (VCI) is a heterogeneous condition manifesting as cognitive impairment resulting from vascular factors. The precise mechanisms underlying this relationship remain unclear, which poses challenges for experimental research. Here, we applied computational approaches like systems biology to unveil and select relevant proteins and pathways related to VCI by studying the crosstalk between cardiovascular and cognitive diseases. In addition, we specifically included signals related to oxidative stress, a common etiologic factor tightly linked to aging, a major determinant of VCI. Our results show that pathways associated with oxidative stress are quite relevant, as most of the prioritized vascular cognitive genes and proteins were enriched in these pathways. Our analysis provided a short list of proteins that could be contributing to VCI: DOLK, TSC1, ATP1A1, MAPK14, YWHAZ, CREB3, HSPB1, PRDX6, and LMNA. Moreover, our experimental results suggest a high implication of glycative stress, generating oxidative processes and post-translational protein modifications through advanced glycation end-products (AGEs). We propose that these products interact with their specific receptors (RAGE) and Notch signaling to contribute to the etiology of VCI.

TREM2 regulates microglial phagocytosis of synapses in innate immune tolerance

Increasing evidence indicates that innate immune cells also possess immunological memory. Microglia are brain-resident innate immune cells and execute inflammatory and phagocytic functions upon environmental stimulation, during which processes triggering receptor expressed on myeloid cells 2 (TREM2) plays an important regulatory role. However, although microglia are known to exhibit innate immune memory related to inflammation when subjected to continuous inflammatory stimuli, whether microglia exhibit innate immune memory related to phagocytosis and whether TREM2 participates in innate immune memory of microglia remain unknown. Herein, we treated WT and Trem2 KO mice with peripheral injection of lipopolysaccharides (LPS) to induce microglial activation or microglial immune tolerance. We found that Tnfα and Il-1β expression levels in the hippocampi were significantly elevated after 1xLPS and then dramatically decreased after 4xLPS in both WT and Trem2 KO mice; and their level changes were indistinguishable between WT and Trem2 KO mice. Moreover, 1xLPS significantly promoted microglial phagocytosis of synapses and caused microglial morphology changes resembling activated status in both WT and Trem2 KO mice. However, 4xLPS significantly reduced synapse phagocytosis and largely reversed morphology changes in WT microglia. While 4xLPS had no effect on reducing synapse phagocytosis in Trem2 KO microglia. RNA-seq analysis revealed that TREM2 deficiency reprogrammed complement and phagosome-related transcriptional landscape during immune tolerance. Our results demonstrate that microglia also exhibit immune tolerance related to phagocytosis of synapses and that TREM2 plays a crucial role in this process possibly through regulating complement system and phagosome-related gene expressions.

Implication of lncRNA MSTRG.81401 in Hippocampal Pyroptosis Induced by P2X7 Receptor in Type 2 Diabetic Rats with Neuropathic Pain Combined with Depression

Major depressive disorder (MDD) is a common complication of diabetes and is often observed alongside diabetic neuropathic pain (DNP) as a comorbidity in diabetic patients. Long non-coding RNA (lncRNA) plays an important role in various pathophysiological processes. The P2X7 receptor is responsible for triggering inflammatory responses, such as pyroptosis, linked to pain and depression. The aim of this study was to investigate the effect of lncRNA MSTRG.81401 on hippocampal pyroptosis induced by the P2X7 receptor in diabetic rats with DNP combined with MDD (DNP + MDD). Our results showed that the expression of lncRNA MSTRG.81401 was significantly elevated in the hippocampus of DNP + MDD rats compared with the control group. Following the administration of shRNA targeting lncRNA MSTRG.81401, a notable elevation in mechanical and thermal pain thresholds was observed in rats with comorbid DNP and MDD. Additionally, significant improvements in depression-like behaviors were evident in the open-field test (OFT), sucrose preference test (SPT), and forced swim test (FST). In the DNP + MDD rats, elevated levels in hippocampal P2X7 receptor mRNA and protein were observed, along with increased co-expression of P2X7 and the astrocytic marker glial fibrillary acidic protein (GFAP). Meanwhile, in DNP + MDD rats, the heightened mRNA expression of NOD-like receptor protein 3 (NLRP3), apoptosis-associated speck-like protein (ASC), pyroptosis-related protein Gasdermin D (GSDMD), caspase-1, IL-1β, IL-18, and TNF-α was detected, in addition to increased serum levels of IL-1β, IL-18 and TNF-α. After shRNA treatment with lncRNA MSTRG.81401, the above abnormal changes in indicators for pyroptosis and inflammation were improved. Therefore, our study demonstrates that shRNA of lncRNA MSTRG.81401 can alleviate the pain and depression-like behaviors in diabetic rats associated with the comorbidity of DNP and MDD by inhibiting the hippocampal P2X7 receptor-mediated pyroptosis pathway and pro-inflammatory responses. This suggests that the P2X7R/NLRP3/caspase-1 implicated pyroptosis and inflammatory scenario may serve as a potential target for the management of comorbid DNP and MDD in diabetes.

Current perspectives on prevention of vascular cognitive impairment and promotion of vascular brain health

INTRODUCTION

The true global burden of vascular cognitive impairment (VCI) is unknown. Reducing risk factors for stroke and cardiovascular disease would inevitably curtail VCI.

AREAS COVERED

The authors review current diagnosis, epidemiology, and risk factors for VCI. VCI increases in older age and by inheritance of known genetic traits. They emphasize modifiable risk factors identified by the 2020 Lancet Dementia Commission. The most profound risks for VCI also include lower education, cardiometabolic factors, and compromised cognitive reserve. Finally, they discuss pharmacological and non-pharmacological interventions.

EXPERT OPINION

By virtue of the high frequencies of stroke and cardiovascular disease the global prevalence of VCI is expectedly higher than prevalent neurodegenerative disorders causing dementia. Since ~ 90% of the global burden of stroke can be attributed to modifiable risk factors, a formidable opportunity arises to reduce the burden of not only stroke but VCI outcomes including progression from mild to the major in form of vascular dementia. Strict control of vascular risk factors and secondary prevention of cerebrovascular disease via pharmacological interventions will impact on burden of VCI. Non-pharmacological measures by adopting healthy diets and encouraging physical and cognitive activities and urging multidomain approaches are important for prevention of VCI and preservation of vascular brain health.

Interplay of G-proteins and Serotonin in the Neuroimmunoinflammatory Model of Chronic Stress and Depression: A Narrative Review

INTRODUCTION

This narrative review addresses the clinical challenges in stress-related disorders such as depression, focusing on the interplay between neuron-specific and pro-inflammatory mechanisms at the cellular, cerebral, and systemic levels.

OBJECTIVE

We aim to elucidate the molecular mechanisms linking chronic psychological stress with low-grade neuroinflammation in key brain regions, particularly focusing on the roles of G proteins and serotonin (5-HT) receptors.

METHODS

This comprehensive review of the literature employs systematic, narrative, and scoping review methodologies, combined with systemic approaches to general pathology. It synthesizes current research on shared signaling pathways involved in stress responses and neuroinflammation, including calcium-dependent mechanisms, mitogen-activated protein kinases, and key transcription factors like NF-κB and p53. The review also focuses on the role of G protein-coupled neurotransmitter receptors (GPCRs) in immune and pro-inflammatory responses, with a detailed analysis of how 13 of 14 types of human 5-HT receptors contribute to depression and neuroinflammation.

RESULTS

The review reveals a complex interaction between neurotransmitter signals and immunoinflammatory responses in stress-related pathologies. It highlights the role of GPCRs and canonical inflammatory mediators in influencing both pathological and physiological processes in nervous tissue.

CONCLUSION

The proposed Neuroimmunoinflammatory Stress Model (NIIS Model) suggests that proinflammatory signaling pathways, mediated by metabotropic and ionotropic neurotransmitter receptors, are crucial for maintaining neuronal homeostasis. Chronic mental stress can disrupt this balance, leading to increased pro-inflammatory states in the brain and contributing to neuropsychiatric and psychosomatic disorders, including depression. This model integrates traditional theories on depression pathogenesis, offering a comprehensive understanding of the multifaceted nature of the condition.

Effect of 40 Hz light flicker on cognitive impairment and transcriptome of hippocampus in right unilateral common carotid artery occlusion mice

Vascular cognitive impairment caused by chronic cerebral hypoperfusion (CCH) seriously affects the quality of life of elderly patients. However, there is no effective treatment to control this disease. This study investigated the potential neuroprotective effect of the 40 Hz light flicker in a mouse model of CCH. CCH was induced in male C57 mice by right unilateral common carotid artery occlusion (rUCCAO), leading to chronic brain injury. The mice underwent 40 Hz light flicker stimulation for 30 days after surgery. The results showed that 40 Hz light flicker treatment ameliorated memory deficits after rUCCAO and alleviated the damage to neurons in the frontal lobe and hippocampus. Light flicker administration at 40 Hz decreased IL-1β and TNF-α levels in the frontal lobe and hippocampus, but immunohistochemistry showed that it did not induce angiogenesis in mice with rUCCAO. Gene expression profiling revealed that the induction of genes was mainly enriched in inflammatory-related pathways. Our findings demonstrate that 40 Hz light flicker can suppress cognitive impairment caused by rUCCAO and that this effect may be involved in the attenuation of neuroinflammation.

Inflammasome Activation Mediates Apoptotic and Pyroptotic Death in Astrocytes Under Ischemic Conditions

Inflammation is a hallmark mechanism of ischemic stroke-induced brain injury. Recent studies have shown that an intracellular multimeric protein complex known as an inflammasome is a key factor for inducing an inflammatory response, and apoptotic and pyroptotic cell death in ischemic stroke. Inflammasome assembly leads to the activation of pro-inflammatory caspases, and the maturation and secretion of pro-inflammatory cytokines IL-1β and IL-18. While the role of inflammasomes in ischemic stroke-induced neuronal death, and microglial activation and cell death have been established, little is known about the role of inflammasomes in astrocytes under ischemic conditions. In this study, we investigated the expression and activation of inflammasome components in protoplasmic and fibrous astrocytes under ischemic conditions. We found that both protoplasmic and fibrous astrocytes expressed a differential increase in inflammasome protein components, and that their activation promoted maturation of IL-1β and IL-18, and secretion of IL-1β, as well as initiating apoptotic and pyroptotic cell death. Pharmacological inhibition of caspase-1 decreased expression of cleaved caspase-1 and production of mature IL-1β, and protected against inflammasome-mediated apoptotic and pyroptotic cell death. Overall, this study provides novel insights into the role of inflammasome signaling in astrocytes under ischemic conditions.

Peripheral inflammation and neurocognitive impairment: correlations, underlying mechanisms, and therapeutic implications

Cognitive impairments, such as learning and memory deficits, may occur in susceptible populations including the elderly and patients who are chronically ill or have experienced stressful events, including surgery, infection, and trauma. Accumulating lines of evidence suggested that peripheral inflammation featured by the recruitment of peripheral immune cells and the release of pro-inflammatory cytokines may be activated during aging and these conditions, participating in peripheral immune system-brain communication. Lots of progress has been achieved in deciphering the core bridging mechanism connecting peripheral inflammation and cognitive impairments, which may be helpful in developing early diagnosis, prognosis evaluation, and prevention methods based on peripheral blood circulation system sampling and intervention. In this review, we summarized the evolving evidence on the prevalence of peripheral inflammation-associated neurocognitive impairments and discussed the research advances in the underlying mechanisms. We also highlighted the prevention and treatment strategies against peripheral inflammation-associated cognitive dysfunction.