Vascular dementia

The emerging role of nitric oxide in the synaptic dysfunction of vascular dementia

With an increase in global aging, the number of people affected by cerebrovascular diseases is also increasing, and the incidence of vascular dementia-closely related to cerebrovascular risk-is increasing at an epidemic rate. However, few therapeutic options exist that can markedly improve the cognitive impairment and prognosis of vascular dementia patients. Similarly in Alzheimer's disease and other neurological disorders, synaptic dysfunction is recognized as the main reason for cognitive decline. Nitric oxide is one of the ubiquitous gaseous cellular messengers involved in multiple physiological and pathological processes of the central nervous system. Recently, nitric oxide has been implicated in regulating synaptic plasticity and plays an important role in the pathogenesis of vascular dementia. This review introduces in detail the emerging role of nitric oxide in physiological and pathological states of vascular dementia and summarizes the diverse effects of nitric oxide on different aspects of synaptic dysfunction, neuroinflammation, oxidative stress, and blood-brain barrier dysfunction that underlie the progress of vascular dementia. Additionally, we propose that targeting the nitric oxide-sGC-cGMP pathway using certain specific approaches may provide a novel therapeutic strategy for vascular dementia.

Danggui-Shaoyao San alleviates cognitive impairment via enhancing HIF-1α/EPO axis in vascular dementia rats

ETHNOPHARMACOLOGICAL RELEVANCE

Invigorating blood circulation to remove blood stasis is a primary strategy in TCM for treating vascular dementia (VaD). Danggui-Shaoyao San (DSS), as a traditional prescription for neuroprotective activity, has been proved to be effective in VaD treatment. However, its precise molecular mechanisms remain incompletely understood.

AIM OF THE STUDY

The specific mechanism underlying the therapeutic effects of DSS on VaD was explored by employing network pharmacology as well as in vivo and in viro experiment validation.

MATERIALS AND METHODS

We downloaded components of DSS from the BATMAN-TCM database for target prediction. The intersection between the components of DSS and targets, PPI network, as well as GO and KEGG enrichment analysis were then performed. Subsequently, the potential mechanism of DSS predicted by network pharmacology was assessed and validated through VaD rat model induced by 2VO operation and CoCl2-treated PC12 cells. Briefly, the DSS extract were first quantified by HPLC. Secondly, the effect of DSS on VaD was studied using MWM test, HE staining and TUNEL assay. Finally, the molecular mechanism of DSS against VaD was validated by Western blot and RT-QPCR experiments.

RESULTS

Through network analysis, 137 active ingredients were obtained from DSS, and 67 potential targets associated with DSS and VaD were identified. GO and KEGG analysis indicated that the action of DSS on VaD primarily involves hypoxic terms and HIF-1 pathway. In vivo validation, cognitive impairment and neuron mortality were markedly ameliorated by DSS. Additionally, DSS significantly reduced the expression of proteins related to synaptic plasticity and neuron apoptosis including PSD-95, SYP, Caspase-3 and BCL-2. Mechanistically, we confirmed DSS positively modulated the expression of HIF-1α and its downstream proteins including EPO, p-EPOR, STAT5, EPOR, and AKT1 in the hippocampus of VaD rats as well as CoCl2-induced PC12 cells. HIF-1 inhibitor YC-1 significantly diminished the protection of DSS on CoCl2-induced PC12 cell damage, with decreased HIF-1α, EPO, EPOR expression.

CONCLUSION

Our results initially demonstrated DSS could exert neuroprotective effects in VaD. The pharmacological mechanism of DSS may be related to its positive regulation on HIF-1α/EPO pathway.

Is Montreal Cognitive Assessment a valuable test for the differentiation of Alzheimer's disease, frontotemporal dementia, dementia with Lewy body, and vascular dementia?

Dementia is one of the growing diseases in the world and has different types based on its definition. The Montreal Cognitive Assessment (MoCA) test has been employed to screen patients with dementia, cognitive impairment, and disruption of daily activities.

Objective

This study examined the diagnostic value of the total MoCA score and its subscores in differentiating Alzheimer's disease (AD), frontotemporal dementia (FTD), dementia with Lewy body (DLB), and vascular dementia (VaD).

Methods

A total of 241 patients (AD=110, FTD=90, DLB=28, and VaD=13) and 59 healthy persons, who were referred to a dementia clinic with memory impairment in Firoozgar Hospital, were included in this study. MoCA tests were performed in all patients and normal persons.

Results

By using the receiver operating characteristic (ROC) curve and measuring the area under the curve (AUC) for the total MoCA score in each group, AUC was 0.616, 0.681, 0.6117, and 0.583 for differentiating AD, FTD, DLB, and VaD patients, respectively. Among the groups, just the VaD group showed no significant usefulness in using the total MoCA score to differentiate it. To compare MoCA subscores, AD patients had higher scores in digit span, literal fluency, and abstraction but lower delayed recall scores compared with FTD patients.

Conclusion

The total MoCA score and its subscores could not differentiate people with different types of dementia in the setting of screening.

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.

The effects of immunomodulatory drugs on cerebral small vessel disease: A mediation Mendelian randomization analysis

BACKGROUND

There are only a few recognized drug targets for cerebral small vessel disease (CSVD). Though inflammation is increasingly implicated in the development of CSVD, it remains unclear whether immunomodulation could become a therapeutic target. Accordingly, the Mendelian randomization (MR) method was used to assess the genetically proxied impacts of IL6 receptor (IL6R) inhibitor, IL1β inhibitor, Tumor necrosis factor (TNF) inhibitor and β-tubulin inhibitor on CSVD through.

METHODS

Single nucleotide polymorphisms (SNPs) near the IL6R, IL1β, TNFRSF1A and β-tubulin genes were identified as genetic proxies for immunomodulatory drugs. These SNPs exhibited significant associations with serum C-reactive protein (CRP) levels in a large European genome-wide association study. The causal effects of immunomodulatory drugs on CSVD manifestations and the mediation influence of 731 peripheral blood immune phenotypes linking these drugs to CSVD manifestations were examined using a two-sample two-step MR approach.

RESULTS

A total of 9, 18, 4 and 1 SNP were identified to proxy the effects of IL1β inhibitor, IL6R inhibitor, TNF inhibitor and β-tubulin inhibitor, respectively. MR analysis showed a significant causal relationship between IL1β inhibition and reduced volume of periventricular white matter hyperintensity (PWMH). IL6R inhibition was associated with a reduced risk of small vessel stroke, decreased axial diffusivity and mean diffusivity. Genetically proxied TNF inhibition may decrease the occurrence of cerebral microbleeds (CMBs) and severe enlarged perivascular spaces located at white matter (WM-EPVS). It could also protect WM integrity, as evidenced by the reduced volumes of PWMH and deep white matter hyperintensity (DWMH). Various peripheral blood immune phenotypes exhibited significant associations with immunomodulatory drugs. Notably, the median fluorescence intensity (MFI) of CD45 on CD8br cells partially mediated the effects of IL1β inhibitor on PWMH volume. Indirect effects of TNF inhibition on PWMH and DWMH volume through the MFI of CD127 on CD28- CD8br cells were observed. The effects of TNF inhibition on the occurrence of any CMBs were partially mediated by the MFI of CD45 on natural killer T cells, and the effects of TNF inhibition on the occurrence of lobar CMBs were partially mediated by the MFI of HLA DR on CD33- HLA DR+ cells. Furthermore, the MFI of HLA DR on CD33- HLA DR+ cells partially mediated the effects of TNF inhibition on WM-EPVS.

CONCLUSIONS

IL1β inhibitor, IL6R inhibitor and TNF inhibitor were associated with lower burden of CSVD while the activation of certain immune cells such as Tregs and myeloid cells partially mediated their protective effects.

Mechanisms of mitophagy and oxidative stress in cerebral ischemia-reperfusion, vascular dementia, and Alzheimer's disease

Neurological diseases have consistently represented a significant challenge in both clinical treatment and scientific research. As research has progressed, the significance of mitochondria in the pathogenesis and progression of neurological diseases has become increasingly prominent. Mitochondria serve not only as a source of energy, but also as regulators of cellular growth and death. Both oxidative stress and mitophagy are intimately associated with mitochondria, and there is mounting evidence that mitophagy and oxidative stress exert a pivotal regulatory influence on the pathogenesis of neurological diseases. In recent years, there has been a notable rise in the prevalence of cerebral ischemia/reperfusion injury (CI/RI), vascular dementia (VaD), and Alzheimer's disease (AD), which collectively represent a significant public health concern. Reduced levels of mitophagy have been observed in CI/RI, VaD and AD. The improvement of associated pathology has been demonstrated through the increase of mitophagy levels. CI/RI results in cerebral tissue ischemia and hypoxia, which causes oxidative stress, disruption of the blood-brain barrier (BBB) and damage to the cerebral vasculature. The BBB disruption and cerebral vascular injury may induce or exacerbate VaD to some extent. In addition, inadequate cerebral perfusion due to vascular injury or altered function may exacerbate the accumulation of amyloid β (Aβ) thereby contributing to or exacerbating AD pathology. Intravenous tissue plasminogen activator (tPA; alteplase) and endovascular thrombectomy are effective treatments for stroke. However, there is a narrow window of opportunity for the administration of tPA and thrombectomy, which results in a markedly elevated incidence of disability among patients with CI/RI. It is regrettable that there are currently no there are still no specific drugs for VaD and AD. Despite the availability of the U.S. Food and Drug Administration (FDA)-approved clinical first-line drugs for AD, including memantine, donepezil hydrochloride, and galantamine, these agents do not fundamentally block the pathological process of AD. In this paper, we undertake a review of the mechanisms of mitophagy and oxidative stress in neurological disorders, a summary of the clinical trials conducted in recent years, and a proposal for a new strategy for targeted treatment of neurological disorders based on both mitophagy and oxidative stress.

Piracetam reduces oxidative stress and mitochondrial function impairment in an in vitro model of vascular dementia

Vascular dementia (VaD) is the most common cause of dementia in older adults. Due to the lack of effective treatment options, there is an urgent need to find an effective pharmaceutical compound to combat VaD. Piracetam has been reported to improve impaired cognitive function in a variety of conditions in both human and animal models. However, the role and mechanism of Piracetam in VaD remain unclear. Therefore this study aimed to elucidate the effect of Piracetam on a cellular model of VaD in vitro. We found that Piracetam enhanced the growth of OGD-stimulated SH-SY5Y cells. In addition, Piracetam inhibited the oxidative stress of OGD-stimulated SH-SY5Y cells. Further, Piracetam improved mitochondrial function of OGD-stimulated SH-SY5Y cells. Mechanistically, Piracetam inhibited the PI3K/Akt/mTOR pathway in OGD-stimulated SH-SY5Y cells. Collectively, Piracetam improved oxidative stress and mitochondrial dysfunction of OGD-stimulated SH-SY5Y cells through PI3K/Akt/mTOR axis. Hence, Piracetam has the potential to serve as a promising drug of VaD.

Magnesium and Cognitive Health in Adults: A Systematic Review and Meta-Analysis

Magnesium (Mg) plays a key role in neurological functioning and manifestations. However, the evidence from randomized controlled trials (RCTs) and cohorts on Mg and cognitive health among adults has not been systematically reviewed. We aimed to examine the associations of various Mg forms (supplements, dietary intake, and biomarkers) with cognitive outcomes by summarizing evidence from RCTs and cohorts. PubMed, Embase, PsycINFO, and the Cochrane Central Register of Controlled Trials were searched for relevant peer-reviewed articles published up to May 3, 2024. Three random-effects models were performed, when appropriate, to evaluate the relationship between Mg and cognitive outcomes: 1) linear meta-regression, 2) nonlinear (quadratic) meta-regression, and 3) meta-analysis using Mg variables categorized based on pre-existing recommendations. Three RCTs and 12 cohort studies were included in this systematic review. Evidence from the limited number of RCTs was insufficient to draw conclusions on the effects of Mg supplements. Cohort studies showed inconsistent dose-response relationships between dietary Mg and cognitive disorders, with high heterogeneity across populations. However, consistent U-shape associations of serum Mg with all-cause dementia and cognitive impairment were found in cohorts, suggesting an optimal serum Mg concentration of ∼0.85 mmol/L. This nonlinear association was detected in meta-regression (Pquadratic = 0.003) and in meta-analysis based on the reference interval of serum Mg (0.75-0.95 mmol/L) [<0.75 compared with 0.85 mmol/L: pooled hazard ratio (HR) = 1.43; 95% confidence interval (CI) = 1.05, 1.93; >0.95 compared with 0.85 mmol/L: pooled HR = 1.30; 95% CI = 1.03, 1.64]. More evidence from RCTs and cohorts is warranted. Future cohort studies should evaluate various Mg biomarkers and collect repeated measurements of Mg intake over time, considering different sources (diet or supplements) and factors affecting absorption (for example, calcium-to-Mg intake ratio). This systematic review was preregistered in PROSPERO (CRD42023423663).

Dementia incidence varied by anticancer drugs and molecular targeted therapy in a population-based cohort study

Anticancer drugs may affect the incidence of dementia by modulating the common pathophysiology between cancer and dementia. However, there is a paucity of research that focused on anticancer drugs with different mechanisms of action and their associations with subtypes of dementia. Therefore, we aimed to investigate the incidence of dementia according to various groups of anticancer drugs. From the Korea National Health Insurance Service database, our retrospective population-based cohort study enrolled 116,506 cancer patients aged 65 years and older who received anticancer drugs between January 1, 2008 and December 31, 2018. The hazard ratio was determined using Cox proportional hazards regression models, comparing each group of anticancer drugs to all other anticancer drugs, after adjusting for covariates. Antimetabolites (HR = 0.91; 95% CI 0.84-0.97) and molecular targeted therapies (HR = 0.60; 95% CI 0.49-0.74) were associated with a decreased incidence of dementia of the Alzheimer type (DAT), but not with vascular dementia. Among molecular targeted therapies, epidermal growth factor receptor inhibitors (HR = 0.60; 95% CI 0.46-0.79) and multikinase inhibitors (HR = 0.49; 95% CI 0.27-0.89) were associated with a low incidence of DAT only. Our findings highlight the potential for targeted repurposing of anticancer drugs to prevent dementia.

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.

Apelin Receptor Homodimerisation Inhibits Hippocampal Neuronal Autophagy via G Protein-Dependent Signalling in Vascular Dementia

Vascular dementia (VD), a progressive vascular cognitive impairment, is characterised by the presence of cerebral hypoperfusion, increased blood-brain barrier permeability, and white matter lesions. Although current treatment strategies primarily focus on risk factors such as hypertension, diabetes, and heart disease, efficient and targeted therapies are lacking and the underlying mechanisms of VD remain unclear. We previously discovered that Apelin receptors (APJ), which are G protein-coupled receptors (GPCRs), can homodimerize and generate signals that are distinct from those of APJ monomers in VD rats. Apelin-13 reduces the level of APJ homodimers and leads to the proliferation of endogenous neural stem cells in the hippocampal dentate gyrus area, suggesting that it has a neuroprotective role. In this study, we established a rat and cellular oxygen-glucose deprivation/reoxygenation VD model to investigate the impact of APJ homodimerisation on autophagy. We found that APJ homodimers protect against VD by inhibiting autophagy through the Gαq and PI3K/Akt/mTOR pathways upon Gαi signalling, both in vivo and in vitro. This discovery provides a promising therapeutic target for chronic cerebral ischaemia-reperfusion diseases and an experimental foundation for the development of drugs that target APJ homodimers.

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.

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.

Comparative efficacy and safety of non-pharmacological interventions as adjunctive treatment for vascular dementia: a systematic review and network meta-analysis

Objectives

The incidence of vascular dementia (VaD) is steadily rising annually, significantly impacting the mental well-being and overall quality of life of the elderly, and imposing substantial economic burdens on families and society. In recent years, non-pharmacological therapies as supplementary treatments for VaD have garnered significant attention and have been extensively utilized in clinical settings. Consequently, a network meta-analysis (NMA) was conducted by us to assess the effectiveness of various non-pharmacological therapies in the management of VaD.

Design

We systematically searched seven databases from their inception up to January 2024 to identify randomized controlled trials focusing on non-pharmacological interventions for the treatment of VaD. The methodological quality and risk of bias were rigorously assessed utilizing the RoB 2.0 evaluation tool. The NMA was performed using R software and STATA 14 software, adhering to frequentist theory principles. Additionally, sensitivity analysis, meta-regression analysis, and funnel plot were conducted to assess the stability, heterogeneity, and publication bias, respectively.

Results

The NMA included 91 eligible studies involving 7,657 patients. The NMA results indicated that in terms of improving Mini-Mental State Examination (MMSE), the following non-pharmacological interventions ranked higher based on p-value: acupuncture_moxibustion_ conventional treatment (ACUP_MB_CT) [P-score = 0.95; pooled mean difference (95% CI): 5.09 (3.82; 6.36)], fastigial nucleus stimulation_CT (FNS_CT) [0.87; 4.51 (2.59; 6.43)], ACUP_rehabilitation training_CT (ACUP_RT_CT) [0.84; 4.19 (2.77; 5.61)], repetitive transcranial magnetic stimulation_CT (rTMS_CT) [0.82; 3.98 (3.08; 4.88)], and aerobic exercise_CT (AE_CT) [0.82; 4.25 (1.86; 6.64)]. Regarding improvement in Activities of Daily Living Scale (ADL), the following non-pharmacological interventions ranked higher based on P-score: ACUP_MB_CT [0.98; 17.21 (13.19; 21.23)], ACUP_RT_CT [0.87; 14.32 (8.43; 20.22)], rTMS_CT [0.78; 11.83 (9.92; 13.75)], and ACUP_CT [0.73; 11.23 (9.26; 13.19)]. No significant adverse reactions were reported in the included studies.

Conclusion

ACUP_MB_CT may be considered the most efficacious intervention for enhancing cognitive function and daily living skills in individuals diagnosed with VaD. Furthermore, ACUP_RT_CT, rTMS_CT, FNS_CT, ACUP_CT, and AE_CT also demonstrate significant clinical utility. Non-pharmacological interventions are unlikely to significantly increase adverse reactions and has a certain degree of safety.Systematic review registration: https://www.crd.york.ac.uk/prospero/, identifier [CRD42024498902].

Efficacy and safety of ginkgo biloba extract combined with donepezil hydrochloride in the treatment of Chinese patients with vascular dementia: A systematic review meta-analysis

Objective: To conduct a meta-analysis of the effectiveness and safety of ginkgo biloba extract combined with donepezil hydrochloride vs. donepezil for the treatment of vascular dementia (VaD). Methods: Four English databases (PubMed, EMBASE, Web of Science, Cochrane Library) and four Chinese databases [the China National Knowledge Infrastructure Wanfang DATA, the Chongqing VIP Database (VIP), China Biomedical Database (CBM)] were manually searched for literature published from dates of the inception of the databases to September 2023. The randomized controlled trials (RCTs) of ginkgo biloba extract with donepezil hydrochloride vs. donepezil for the treatment of VaD were included. Relevant literature was screened, and the data in the included studies were extracted for quality assessment according to the Risk of bias tool. Results: A total of 1,309 participants were enrolled in the 15 RCTs. Of these, 656 participants were in the experimental group (ginkgo biloba extract combined with donepezil) and 653 participants were in the control group (donepezil).The results showed that combination therapy was superior to donepezil alone, and there were statistically significant differences in several outcomes including RR in change for total effective rate (1.28, 95% confidence intervals 1.20, 1.38, p < 0.001), MD in change for Mini-Mental State Examination score (2.98, 95%CI 2.31, 3.65, p < 0.001), Barthel Index score (8.55,95%CI 1.11, 15.99, p = 0.024), Activity of Daily Living Scale (ADL)score (10.11,95% CI 7.16,13.07,p < 0.001). Conclusion: Ginkgo biloba extract combined with donepezil dramatically improved the total effective rate, MMSE, BI and ADL scores, and decreased homocysteine (HCY), plasma viscosity (PV), whole blood viscosity at high cut (BVH) and whole blood viscosity at low cut (BVL) in VaD patients, while the effect on mean flow velocity and pulse index (PI) of middle cerebral artery (MCA) is not obvious. However, more relevant high-quality RCTs are needed to validate these results. Systematic Review Registration: Identifier CRD42023474678.

Dysregulation of the renin-angiotensin system in vascular dementia

The renin-angiotensin system (RAS) regulates systemic and cerebral blood flow and is dysregulated in dementia. The major aim of this study was to determine if RAS signalling is dysregulated in vascular dementia. We measured markers of RAS signalling in white matter underlying the frontal and occipital cortex in neuropathologically confirmed cases of vascular dementia (n = 42), Alzheimer's disease (n = 50), mixed AD/VaD (n = 50) and age-matched controls (n = 50). All cases were stratified according to small vessel disease (SVD) severity across both regions. ACE-1 and ACE-2 protein and activity was measured by ELISA and fluorogenic peptide assays respectively, and angiotensin peptide (Ang-II, Ang-III and Ang-(1-7)) levels were measured by ELISA. ACE-1 protein level and enzyme activity, and Ang-II and Ang-III, were elevated in the white matter in vascular dementia in relation to SVD severity. ACE-1 and Ang-II protein levels were inversely related to MAG:PLP1 ratio, a biochemical marker of brain tissue oxygenation that when reduced indicates cerebral hypoperfusion, in a subset of cases. ACE-2 level was elevated in frontal white matter in vascular dementia. Ang-(1-7) level was elevated across all dementia groups compared to age-matched controls but was not related to SVD severity. RAS signalling was not altered in the white matter in Alzheimer's disease. In the overlying frontal cortex, ACE-1 protein was reduced and ACE-2 protein increased in vascular dementia, whereas angiotensin peptide levels were unchanged. These data indicate that RAS signalling is dysregulated in the white matter in vascular dementia and may contribute to the pathogenesis of small vessel disease.

Nicotinamide riboside alleviates brain dysfunction induced by chronic cerebral hypoperfusion via protecting mitochondria

Chronic cerebral hypoperfusion (CCH) is an enduring inadequate blood flow to the brain, resulting in vascular dementia (VaD). However, the effective treatment strategies are lacking. Supplementing with nicotinamide adenine dinucleotide (NAD+) has shown neuroprotective benefits in other neurodegenerative disorders. Nicotinamide riboside (NR), as a precursor of NAD+, is believed to hold promise in improving mitochondrial health, autophagy, and cognitive function. Meanwhile, NR has unique oral bioavailability, good tolerability, and minimal side effects, and it is the most promising for clinical translation. However, the effectiveness of NR in treating CCH-related VaD is still uncertain. The present study examined the neuroprotective effects of NR supplementation and its underlying mechanisms in a CCH rat model. The rats with CCH were given NR at a daily dosage of 400 mg/kg for 3 months. NR supplementation increased blood and brain NAD+ levels and improved brain function in CCH rats, including cognitive function and oxygenation capacity. It also reduced hippocampal neuronal loss and abnormalities and mitigated the decrease in dendritic spine density. The analysis of RNA sequencing in hippocampal tissue supports these findings. Electron microscopy and protein detection results suggest that NR may maintain mitochondrial structural integrity and exert a protective role by attenuating mitochondrial fission and impaired autophagy flux caused by CCH. In conclusion, these findings offer evidence for the neuroprotective potential of NR supplementation in ameliorating cognitive impairment induced by CCH.

Artesunate improves learning and memory impairment in rats with vascular cognitive impairment by down-regulating the level of autophagy in cerebral cortex neurons

Background

Vascular cognitive impairment (VCI) is the second leading cause of dementia. Cognitive impairment is a common consequence of VCI. However, there is no effective treatment for VCI and the underlying mechanism of its pathogenesis remains unclear. This study to investigate whether artesunate (ART) can improve the learning and memory function in rats with VCI by down-regulating he level of autophagy in cerebral cortex neurons.

Methods

The models for VCI were the rat bilateral common carotid artery occlusion (BACCO), which were randomized into three groups including the sham operation group (Sham), model + vehicle group (Model) and model + ART group (ART). Then the animal behaviors were recorded, as well as staining the results of cortical neurons. Western blot was performed to determine the protein expressions of LC3BⅡ/Ⅰ, p-AMPK, p-mTOR, and Beclin-1.

Results

Behavioral outcomes and the protein expressions in Model group were supposedly affected by the induction of autophagy in cerebral cortex neurons. Compared to the Model group, ART improved memory impairment in VCI rats. And the expression of LC3BⅡ/Ⅰ, p-AMPK/AMPK, Beclin-1 is significant decreased in the ART group, while significant increases of p-mTOR/mTOR were showed. These results suggest that ART improved learning and memory impairment in VCI rats by down-regulating the level of autophagy in cerebral cortex neurons.

Conclusion

The results suggest that autophagy occurs in cerebral cortex neurons in rats with VCI. It is speculated that ART can improve learning and memory impairment in VCI rats by down-regulating the level of autophagy in cerebral cortex neurons.

Verbal Learning and Memory Deficits across Neurological and Neuropsychiatric Disorders: Insights from an ENIGMA Mega Analysis

Deficits in memory performance have been linked to a wide range of neurological and neuropsychiatric conditions. While many studies have assessed the memory impacts of individual conditions, this study considers a broader perspective by evaluating how memory recall is differentially associated with nine common neuropsychiatric conditions using data drawn from 55 international studies, aggregating 15,883 unique participants aged 15-90. The effects of dementia, mild cognitive impairment, Parkinson's disease, traumatic brain injury, stroke, depression, attention-deficit/hyperactivity disorder (ADHD), schizophrenia, and bipolar disorder on immediate, short-, and long-delay verbal learning and memory (VLM) scores were estimated relative to matched healthy individuals. Random forest models identified age, years of education, and site as important VLM covariates. A Bayesian harmonization approach was used to isolate and remove site effects. Regression estimated the adjusted association of each clinical group with VLM scores. Memory deficits were strongly associated with dementia and schizophrenia (p < 0.001), while neither depression nor ADHD showed consistent associations with VLM scores (p > 0.05). Differences associated with clinical conditions were larger for longer delayed recall duration items. By comparing VLM across clinical conditions, this study provides a foundation for enhanced diagnostic precision and offers new insights into disease management of comorbid disorders.

A novel phthalein component ameliorates neuroinflammation and cognitive dysfunction by suppressing the CXCL12/CXCR4 axis in rats with vascular dementia

ETHNOPHARMACOLOGICAL RELEVANCE

Chuanxiong, a plant of the Umbelliferae family, is a genuine medicinal herb from Sichuan Province. Phthalides are one of its main active components and exhibit good protective effect against cerebrovascular diseases. However, the mechanism by which phthalides exert neuroprotective effects is still largely unclear.

AIM OF THE STUDY

In this study, we extracted a phthalein component (named as QBT) from Ligusticum Chuanxiong, and investigated its neuroprotective effects against vascular dementia (VaD) rats and the underlying mechanism, focusing on the chemokine 12 (CXCL12)/chemokine (C-X-C motif) receptor 4 (CXCR4) axis.

METHODS

A rat model of VaD was established, and treated with QBT. Cognitive dysfunction in VaD rats was assessed using the Y-maze, new object recognition, and Morris water maze tests. Neuronal damage and inflammatory response in VaD rats were examined through Nissl staining, immunofluorescence, enzyme-linked immunospecific assay, and western blotting analysis. Furthermore, the effects of QBT on CXCL12/CXCR4 axis and its downstream signaling pathways, Janus kinase 2 (JAK2)/signal transducers and activators of transcription 3 (STAT3) and phosphatidylinositol 3 kinase (PI3K)/protein kinase B (AKT)/nuclear factor-κB (NF-κB), were investigated in VaD rats and BV2 microglial cells exposed to oxygen glucose deprivation.

RESULTS

QBT significantly alleviated cognitive dysfunction and neuronal damage in VaD rats, along with inhibition of VaD-induced over-activation of microglia and astrocytes and inflammatory response. Moreover, QBT exhibited anti-inflammatory effects by inhibiting the CXCL12/CXCR4 axis and its downstream JAK2/STAT3 and PI3K/AKT/NF-κB pathways, thereby attenuating the neuroinflammatory response both in vivo and in vitro.

CONCLUSION

QBT effectively mitigated neuronal damage and cognitive dysfunction in VaD rats, exerting neuroprotective effects by suppressing neuroinflammatory response through inhibition of the CXCL12/CXCR4 axis.

The criteria used to rule out mild cognitive impairment impact dementia incidence rates in subjective cognitive decline

BACKGROUND

The research criteria for subjective cognitive decline (SCD) exclude mild cognitive impairment (MCI), but do not stipulate the use of specific MCI criteria. This study compared different approaches to defining (i.e., excluding) MCI during the ascertainment of SCD, focusing on the impact on dementia incidence rates in SCD.

METHODS

This cohort study utilized routine healthcare data collected in the Essex Memory Clinic from 1999 to 2023. Two different operationalizations of the SCD criteria were used to categorize the cohort into two SCD patient samples. One sample was based on local clinical practice - MCI was excluded according to the Winblad criteria (this sample was termed SCDWinblad). The other sample was created via the retrospective application of the Jak/Bondi criteria for the exclusion of MCI (termed SCDJak/Bondi). Only patients aged ≥ 55 years at baseline with ≥ 12 months follow-up were considered for inclusion. The initial clinical/demographic characteristics of the samples were compared. Rates of incident dementia were calculated for each sample, and unadjusted and Mantel-Haenszel-adjusted incidence rate ratios were calculated to compare dementia incidence between the SCD samples.

RESULTS

The Essex Memory Clinic database included 2,233 patients in total. The SCD and study eligibility criteria were used to select SCDWinblad (n = 86) and SCDJak/Bondi (n = 185) samples from the database. Median follow-up (3 years) did not differ between the two samples. The SCDJak/Bondi sample was significantly older than the SCDWinblad at first assessment (median age: 74 versus 70 years) and had poorer scores on tests of global cognition, immediate and delayed verbal recall, and category fluency. Following adjustment for age, the dementia incidence rate ratio [95% confidence interval] was 3.7 [1.5 to 9.3], indicating a significantly greater rate of progression to dementia in SCDJak/Bondi.

CONCLUSIONS

This study highlights that the approach used to ascertain SCD has important implications for both SCD phenotypes and prognosis. This underscores the importance of how MCI is operationalized within SCD studies. More broadly, the findings add to a growing body of work indicating that objective cognition should not be overlooked in SCD, and offer a potential explanation for the heterogeneity across the SCD prognostic literature.

Repetitive transcranial magnetic stimulation impacts the executive function of patients with vascular cognitive impairment: a systematic review and meta-analysis

Objective

Executive dysfunction is a core symptom of vascular cognitive impairment (VCI), which seriously affects patients' prognosis. This paper aims to investigate the effectiveness of rTMS on executive function in VCI.

Methods

The databases selected for this study included Pubmed, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang, China Science and Technology Journal Database (VIP), and China Biology Medicine Disc (CBM). The screening times were conducted from the time of library construction until August 23, 2023. The inclusion criteria for this meta-analysis were randomized controlled trials (RCTs) on rTMS for VCI, which include executive function scores. The primary metrics were executive subscale scores of the Cognitive Comprehensive Scale and total scores of the Executive Specificity Scale. The secondary metrics were subscale scores of the Executive Specificity Scale. The quality of each eligible study was assessed using the Cochrane Risk of Bias tool. Meta-analysis and bias analysis were performed using Stata (version 16.0) and RevMan (version 5.3).

Results

A total of 20 high-quality clinical RCTs with 1,049 samples were included in this paper. The findings from the primary outcomes revealed that within the rTMS group, there were significantly higher scores observed for the executive sub-item on the cognitive composite scale (SMD = 0.93, 95% CI = 0.77-1.08, p < 0.00001, I 2 = 14%) and the total score on the executive specific scale (SMD = 0.69, 95% CI = 0.44-0.94, p < 0.00001, I 2 = 0%) compared to the control group. As for the secondary outcome measures, as shown by the Trail Making Test-A (time) (MD = -35.75, 95% CI = -68.37 to -3.12, p = 0.03, I 2 = 55%), the Stroop-C card (time) (SMD = -0.46, 95% CI = -0.86 to -0.06, p = 0.02, I 2 = 0%) and the Stroop-C card (correct number) (SMD = 0.49, 95% CI = 0.04-0.94, p = 0.03, I 2 = 0%), the experimental group shorts time and enhances accuracy of executive task in comparison to the control group. Subgroup analysis of the main outcome demonstrated that intermittent theta burst stimulation (iTBS), higher frequency, lower intensity, longer duration, and combined comprehensive therapy exhibited superior efficacy.

Conclusion

rTMS is effective in the treatment of the executive function of VCI. The present study has some limitations, so multi-center, large-sample, objective indicators and parameters are needed to further explore in the future.Systematic review registration:https://www.crd.york.ac.uk/prospero/, CRD42023459669.

Pin1-catalyzed conformational regulation after phosphorylation: A distinct checkpoint in cell signaling and drug discovery

Protein phosphorylation is one of the most common mechanisms regulating cellular signaling pathways, and many kinases and phosphatases are proven drug targets. Upon phosphorylation, protein functions can be further regulated by the distinct isomerase Pin1 through cis-trans isomerization. Numerous protein targets and many important roles have now been elucidated for Pin1. However, no tools are available to detect or target cis and trans conformation events in cells. The development of Pin1 inhibitors and stereo- and phospho-specific antibodies has revealed that cis and trans conformations have distinct and often opposing cellular functions. Aberrant conformational changes due to the dysregulation of Pin1 can drive pathogenesis but can be effectively targeted in age-related diseases, including cancers and neurodegenerative disorders. Here, we review advances in understanding the roles of Pin1 signaling in health and disease and highlight conformational regulation as a distinct signal transduction checkpoint in disease development and treatment.

Edaravone dexborneol attenuates cognitive impairment in a rat model of vascular dementia by inhibiting hippocampal oxidative stress and inflammatory responses and modulating the NMDA receptor signaling pathway

Exploring the intricate pathogenesis of Vascular Dementia (VD), there is a noted absence of potent treatments available in the current medical landscape. A new brain-protective medication developed in China, Edaravone dexboeol (EDB), has shown promise due to its antioxidant and anti-inflammatory properties, albeit with a need for additional research to elucidate its role and mechanisms in VD contexts. In a research setup, a VD model was established utilizing Sprague-Dawley (SD) rats, subjected to permanent bilateral typical carotid artery occlusion (2VO). Behavioral assessment of the rats was conducted using the Bederson test and pole climbing test, while cognitive abilities, particularly learning and memory, were evaluated via the novel object recognition test and the Morris water maze test. Ensuing, the levels of malondialdehyde (MDA), superoxide dismutase (SOD), IL-1β, IL-6, IL-4, and tumor necrosis factor-α (TNF-α) were determined through Enzyme-Linked Immunosorbent Assay (ELISA). Synaptic plasticity-related proteins, synaptophysin (SYP), post-synaptic density protein 95 (PSD-95), and N-methyl-D-aspartate (NMDA) receptor proteins (NR1, NR2A, NR2B) were investigated via Western blotting technique. The findings imply that EDB has the potential to ameliorate cognitive deficiencies, attributed to VD, by mitigating oxidative stress, dampening inflammatory responses, and modulating the NMDA receptor signaling pathway, furnishing new perspectives into EDB's mechanism and proposing potential avenues for therapeutic strategies in managing VD.

Age-related differences in network controllability are mitigated by redundancy in large-scale brain networks

The aging brain undergoes major changes in its topology. The mechanisms by which the brain mitigates age-associated changes in topology to maintain robust control of brain networks are unknown. Here we use diffusion MRI data from cognitively intact participants (n = 480, ages 40-90) to study age-associated differences in the average controllability of structural brain networks, topological features that could mitigate these differences, and the overall effect on cognitive function. We find age-associated declines in average controllability in control hubs and large-scale networks, particularly within the frontoparietal control and default mode networks. Further, we find that redundancy, a hypothesized mechanism of reserve, quantified via the assessment of multi-step paths within networks, mitigates the effects of topological differences on average network controllability. Lastly, we discover that average network controllability, redundancy, and grey matter volume, each uniquely contribute to predictive models of cognitive function. In sum, our results highlight the importance of redundancy for robust control of brain networks and in cognitive function in healthy-aging.

The Involvement of Antioxidants in Cognitive Decline and Neurodegeneration: Mens Sana in Corpore Sano

With neurodegenerative disorders being on the rise, a great deal of research from multiple fields is being conducted in order to further knowledge and propose novel therapeutic interventions. Among these investigations, research on the role of antioxidants in contrasting cognitive decline is putting forward interesting and promising results. In this review, we aim to collect evidence that focused on the role of a variety of antioxidants and antioxidant-rich foods in improving or stabilizing cognitive functions, memory, and Alzheimer's disease, the most common neurodegenerative disorder. Specifically, we considered evidence collected on humans, either through longitudinal studies or randomized, placebo-controlled ones, which evaluated cognitive performance, memory abilities, or the progression level of neurodegeneration. Overall, despite a great deal of variety between study protocols, cohorts of participants involved, neuropsychological tests used, and investigated antioxidants, there is a solid trend that suggests that the properties of antioxidants may be helpful in hampering cognitive decline in older people. Thus, the help of future research that will further elucidate the role of antioxidants in neuroprotection will lead to the development of novel interventions that will take into account such findings to provide a more global approach to treating neurodegenerative disorders.

Causal relationships between gut microbiota and dementia: A two-sample, bidirectional, Mendelian randomization study

BACKGROUND

Existing evidence suggests that gut microbiota represent a significant environmental risk factor for various forms of dementia, including Alzheimer's dementia, vascular dementia, and dementia in other diseases classified elsewhere. However, the exact causal relationships between gut microbiota and the different forms of dementia or their subtypes remain unclear.

AIM

To investigate putative causal relationships between gut microbiota and dementia or its subtypes using Mendelian randomization (MR) analysis.

METHODS

A bidirectional, two-sample, MR analysis was conducted utilizing publicly available gut microbiota-related genome-wide association study (GWAS) summary data from the MiBioGen consortium alongside GWAS summary statistics for dementia and its subtypes from the FinnGen consortium. Instrumental variables were selected according to the fundamental tenets of MR and their strengths were evaluated using the F-statistic. Five MR methods were employed, and the robustness of our findings was validated. To account for multiple comparisons, we applied the Bonferroni method for P-value adjustment.

RESULTS

We identified several gut microbiota taxa exhibiting putative causal relationships with dementia or its subtypes, potentially serving as risk or protective factors for the disease. In addition, reverse MR analysis indicated that the relative abundance of several gut microbiota taxa might be influenced by dementia or its subtypes. An exhaustive sensitivity analysis confirmed the absence of heterogeneity and horizontal pleiotropy. After applying correction for multiple testing, we observed that the order Bacillales (odds ratio: 0.830, 95% confidence interval: 0.740-0.932, P = 0.00155, Padjust = 0.0311) exhibited a strong association with Alzheimer's disease-related dementia.

CONCLUSION

The results suggest that gut microbiota is causally associated with dementia. Our findings provide novel insights into the pathophysiology of dementia and have important implications for its treatment and prevention.

Low serum HDL-cholesterol is associated with increased risk of the subcortical small vessel type of dementia

Background

There are conflicting results whether serum lipid pattern is related to the amount of white matter hyperintensities (WMHs) on magnetic resonance imaging. Little is known of the associations between lipid concentrations and the subsequent risk of the subcortical small vessel type of dementia (SSVD), in which WMHs are a prominent manifestation. Here, we determined whether lipid levels are associated with the risk of SSVD, Alzheimer's disease (AD), or mixed dementia (combined AD and SSVD).

Methods

This was a longitudinal, prospective study of 329 patients with subjective or objective mild cognitive impairment at baseline. The statistical analyses included Cox proportional hazards regression with adjustments for age, gender, education, body mass index, current smoking, hypertension, diabetes mellitus, and APOE ε4 genotype.

Results

During the follow-up (mean 4.1 years), 80 patients converted to dementia [SSVD, n = 15 (5 %); AD, n = 39 (12 %); and mixed dementia, n = 26 (8 %)]. Serum high-density lipoprotein cholesterol (HDL, per SD increase) was inversely associated with the risk of SSVD, whereas triglycerides (TG), low-density lipoprotein cholesterol (LDL)/HDL ratio, and TG/HDL ratio were positively associated with SSVD risk. Furthermore, the lowest HDL tertile was associated with a sevenfold, and the highest tertile of TG/HDL ratio with a threefold, increase in SSVD risk. There were no associations with the risk of AD or mixed dementia after adjustment for covariates.

Conclusion

In a memory clinic population, low HDL and high TG/HDL ratio were independent risk factors of SSVD, but not of AD or mixed dementia.

Brain health index as a predictor of possible vascular dementia in the Mexican health and aging study 2012-2015

To determine the burden of disease among subjects at risk of developing stroke or dementia, brain health indexes (BHI) tend to rely on anatomical features. Recent definitions emphasize the need of a broader perspective that encompasses cardiovascular risk factors (CVRFS) and lifestyle components which can be considered partial contributors to optimal brain health. In this study, we aimed to establish the association and risk detected by a Brain Health Index and the risk of possible vascular dementia (PVD) using data from the Mexican Health and Aging Study (MHAS) 2012-2015. The MHAS is a longitudinal study of adults aged ≥ 50 years. We analyzed the data obtained between 2012 and 2015. CVRFS included in the index were diabetes mellitus, hypertension, myocardial infarction, depression, obesity, physical inactivity, and smoking history. A PVD diagnosis was established when scores in the Cross-Cultural Cognitive Examination were below reference norms and limitations in ≥1 instrumental activities of daily living and a history of stroke were present. A multinomial regression model was developed to determine the association between BHI scores and PVD. In 2015, 75 PVD cases were identified. Mean age was 67.1 ±13.2 years, 35.8% were female, and the mean educational level was 5.8 ±5.5 years. In cases with a higher score in the BHI, the model revealed a hazards ratio of 1.63 (95% CI: 1.63-1.64, p< 0.001) for PVD. In this longitudinal study, with the use of a feasible multifactorial BHI in the Mexican population, a greater score was associated with a 1.63-fold risk of developing PVD during the 3-year follow-up, while the risk for stroke was 1.75. This index could potentially be used to predict the risk of PVD in adults with modifiable CVRFS.

Exploring the Intersection of Dementia and Myocardial Infarction: Vascular Perspectives

Emerging evidence underscores the relationship between myocardial infarction and dementia, implicating a profound influence on patient health. The bidirectional relationship between myocardial infarction and dementia is highlighted by pathophysiological changes in vasculature function, lifestyle factors, and environmental influences. Our literature review aims to explore the complex relationship between these 2 pathologies and highlight the pathways by which they mutually influence each other.

Effects of schisandrin B on hypoxia-related cognitive function and protein expression in vascular dementia rats

Vascular dementia (VD) a heterogenous group of brain disorders in which cognitive impairment is attributable to vascular risk factors and cerebrovascular disease. A common phenomenon in VD is a dysfunctional cerebral regulatory mechanism associated with insufficient cerebral blood flow, ischemia and hypoxia. Under hypoxic conditions oxygen supply to the brain results in neuronal death leading to neurodegenerative diseases including Alzheimer's (AD) and VD. In conditions of hypoxia and low oxygen perfusion, expression of hypoxia-inducible factor 1 alpha (HIF-1α) increases under conditions of low oxygen and low perfusion associated with upregulation of expression of hypoxia-upregulated mitochondrial movement regulator (HUMMR), which promotes anterograde mitochondrial transport by binding with trafficking protein kinesin 2 (TRAK2). Schisandrin B (Sch B) an active component derived from Chinese herb Wuweizi prevented β-amyloid protein induced morphological alterations and cell death using a SH-SY5Y neuronal cells considered an AD model. It was thus of interest to determine whether Sch B might also alleviate VD using a rat bilateral common carotid artery occlusion (BCAO) dementia model. The aim of this study was to examine the effects of Sch B in BCAO on cognitive functions such as Morris water maze test and underlying mechanisms involving expression of HIF-1α, TRAK2, and HUMMR levels. The results showed that Sch B improved learning and memory function of rats with VD and exerted a protective effect on the hippocampus by inhibition of protein expression of HIF-1α, TRAK2, and HUMMR factors. Evidence indicates that Sch B may be considered as an alternative in VD treatment.

The effects of white matter hyperintensities on MEG power spectra in cognitively healthy aging

Objective

This study sought to identify magnetoencephalography (MEG) power spectra patterns associated with cerebrovascular damage (white matter hyperintensities - WMH) and their relationship with cognitive performance and brain structure integrity in aging individuals without cognitive impairment.

Methods

We hypothesized a "slowness" pattern characterized by increased power in δ and θ bands and decreased power in the β band associated with the severity of vascular damage. MEG signals were analyzed in cognitively healthy older adults to investigate these associations.

Results

Contrary to expectations, we did not observe an increase in δ and θ power. However, we found a significant negative correlation between β band power and WMH volume. This β power reduction was linked to structural brain changes, such as larger lateral ventricles, reduced white matter volume, and decreased fractional anisotropy in critical white matter tracts, but not to cognitive performance. This suggests that β band power reduction may serve as an early marker of vascular damage before the onset of cognitive symptoms.

Conclusion

Our findings partially confirm our initial hypothesis by demonstrating a decrease in β band power with increased vascular damage but not the anticipated increase in slow band power. The lack of correlation between the βpow marker and cognitive performance suggests its potential utility in early identification of at-risk individuals for future cognitive impairment due to vascular origins. These results contribute to understanding the electrophysiological signatures of preclinical vascular damage and highlight the importance of MEG in detecting subtle brain changes associated with aging.

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.

SGLT1 and SGLT2 inhibition, circulating metabolites, and cerebral small vessel disease: a mediation Mendelian Randomization study

BACKGROUND

Sodium-glucose cotransporter 2 (SGLT2) and SGLT1 inhibitors may have additional beneficial metabolic effects on circulating metabolites beyond glucose regulation, which could contribute to a reduction in the burden of cerebral small vessel disease (CSVD). Accordingly, we used Mendelian Randomization (MR) to examine the role of circulating metabolites in mediating SGLT2 and SGLT1 inhibition in CSVD.

METHODS

Genetic instruments for SGLT1/2 inhibition were identified as genetic variants, which were both associated with the expression of encoding genes of SGLT1/2 inhibitors and glycated hemoglobin A1c (HbA1c) level. A two-sample two-step MR was used to determine the causal effects of SGLT1/2 inhibition on CSVD manifestations and the mediating effects of 1400 circulating metabolites linking SGLT1/2 inhibition with CSVD manifestations.

RESULTS

A lower risk of deep cerebral microbleeds (CMBs) and small vessel stroke (SVS) was linked to genetically predicted SGLT2 inhibition. Better white matter structure integrity was also achieved, as evidenced by decreased mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD), as well as lower deep (DWMH) and periventrivular white matter hyperintensity (PWMH) volume. Inhibiting SGLT2 could also lessen the incidence of severe enlarged perivascular spaces (EPVS) located at white matter, basal ganglia (BG) and hippocampus (HIP). SGLT1 inhibition could preserve white matter integrity, shown as decreased MD of white matter and DWMH volume. The effect of SGLT2 inhibition on SVS and MD of white matter through the concentration of 4-acetamidobutanoate and the cholesterol to oleoyl-linoleoyl-glycerol (18:1 to 18:2) ratio, with a mediated proportion of 30.3% and 35.5% of the total effect, respectively.

CONCLUSIONS

SGLT2 and SGLT1 inhibition play protective roles in CSVD development. The SGLT2 inhibition could lower the risk of SVS and improve the integrity of white matter microstructure via modulating the level of 4-acetamidobutanoate and cholesterol metabolism. Further mechanistic and clinical studies research are needed to validate our findings.

BDNF Signaling in Vascular Dementia and Its Effects on Cerebrovascular Dysfunction, Synaptic Plasticity, and Cholinergic System Abnormality

Vascular dementia (VaD) is the second most common type of dementia and is characterized by memory impairment, blood-brain barrier disruption, neuronal cell loss, glia activation, impaired synaptic plasticity, and cholinergic system abnormalities. To effectively prevent and treat VaD a good understanding of the mechanisms underlying its neuropathology is needed. Brain-derived neurotrophic factor (BDNF) is an important neurotrophic factor with multiple functions in the systemic circulation and the central nervous system and is known to regulate neuronal cell survival, synaptic formation, glia activation, and cognitive decline. Recent studies indicate that when compared with normal subjects, patients with VaD have low serum BDNF levels and that BDNF deficiency in the serum and cerebrospinal fluid is an important indicator of VaD. Here, we review current knowledge on the role of BDNF signaling in the pathology of VaD, such as cerebrovascular dysfunction, synaptic dysfunction, and cholinergic system impairment.

Long non-coding RNAs H19 and NKILA are associated with the risk of death and lacunar stroke in the elderly population

INTRODUCTION

Differential expression of long non-coding RNAs (lncRNAs) is a hallmark of cardiovascular aging, cerebrovascular diseases, and neurodegenerative disorders. This research article investigates the association between a panel of lncRNAs and the risk of death and ischemic stroke in a cohort of non-institutionalized elderly subjects.

METHOD

A total of 361 healthy individuals aged 75 years old, prospectively recruited in the Vienna Transdanube Aging (VITA) cohort, were included. Expression of lncRNAs at baseline was assessed using quantitative polymerase chain reaction PCR with pre-amplification reaction, using 18S for normalization. The primary endpoint was all-cause mortality; the secondary endpoint was the incidence of new ischemic brain lesions. Death was assessed over a 14-year follow-up, and ischemic brain lesions were evaluated by magnetic resonance imaging (MRI) over a 90-month follow-up. Ischemic brain lesions were divided into large brain infarcts (Ø≥ 1.5 cm) or lacunes (Ø< 1.5 cm) RESULTS: The primary endpoint occurred in 53.5 % of the study population. The incidence of the secondary endpoint was 16 %, with a 3.3 % being large brain infarcts, and a 12.7 % lacunes. After adjustment for potential confounders, the lncRNA H19 predicted the incidence of the primary endpoint (HR 1.194, 95 % C.I. 1.012-1.409, p = 0.036), whereas the lncRNA NKILA was associated with lacunar stroke (HR 0.571, 95 % C.I. 0.375-0.868, p = 0.006).

CONCLUSION

In a prospective cohort of non-institutionalized elderly subjects, high levels of lncRNA H19 are associated with a higher risk of death, while low levels of lncRNA NKILA predict an increased risk of lacunar stroke.

Circulating cytokines and vascular dementia: A bi-directional Mendelian randomization study

Inflammatory responses are associated with the development of vascular dementia (VaD). Circulating cytokines modulate the inflammatory response and are important for the immune system. To further elucidate the role of the immune system in VaD, we used Mendelian randomization (MR) to comprehensively and bi-directionally assess the role of circulating cytokines in VaD. Using state-of-the-art genome-wide association studies, we primarily assessed whether different genetic levels of 41 circulating cytokines affect the risk of developing VaD and, in turn, whether the genetic risk of VaD affects these circulating cytokines. We used inverse variance weighting (IVW) and several other MR methods to assess the bidirectional causality between circulating cytokines and VaD, and performed sensitivity analyses. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) was inversely associated with VaD risk [odds ratio (OR): 0.74, 95 % confidence interval (CI): 0.60-0.92, P = 0.007, 0.007]. VaD was associated with seven circulating cytokines: macrophage inflammatory protein 1b (MIP-1 beta) [OR: 1.05, 95 % CI: 1.01-1.08, P = 0.009], Interleukin-12p70 (IL-12) [OR: 1.04, 95 % CI: 1.00-1.08, P = 0.047], Interleukin-17 (IL-17) [OR: 1.04, 95 % CI: 1.00-1.07, P = 0.038], Interleukin-7 (IL-7) [OR: 1.07, 95 % CI: 1.02-1.12, P = 0.009], Interferon gamma (IFN-γ) [OR: 1.03, 95 % CI: 1.00-1.07, P = 0.046], Granulocyte-colony stimulating factor (GCSF) [OR: 1.06, 95 % CI: 1.02-1.09, P = 0.001], Fibroblast growth factor (FGF) [P = 0.001], and Fibroblast growth factor (FGF) [P = 0.001]. Fibroblast growth factor basic (FGF-Basic) [OR: 1.04, 95 % CI: 1.01-1.08, P = 0.02] were positively correlated. Circulating cytokines are associated with VaD, and further studies are needed to determine whether they are effective targets for intervention to prevent or treat VaD.

Integrated Analysis of Chromatin and Transcriptomic Profiling Identifies PU.1 as a Core Regulatory Factor in Microglial Activation Induced by Chronic Cerebral Hypoperfusion

In addition to causing white matter lesions, chronic cerebral hypoperfusion (CCH) can also cause damage to gray matter, but the underlying molecular mechanisms remain largely unknown. In order to obtain a better understanding of the relationship between gene expression and transcriptional regulation alterations, novel upstream regulators could be identified using integration analysis of the transcriptome and epigenetic approaches. Here, a bilateral common carotid artery stenosis (BCAS) model was established for inducing CCH in mice. The spatial cognitive function of mice was evaluated, and changes in cortical microglia morphology were observed. RNA-sequencing (RNA-seq) and the assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq) were performed on isolated mouse cortical brain tissue. Then, a systematic joint analysis of BCAS hypoperfusion-induced cortex-specific RNA-seq and ATAC-seq was conducted in order to assess the extent of the correlation between the two, and PU.1 was found to be greatly enriched through motif analysis and transcription factor annotation. Also, the core regulatory factor PU.1 induced by BCAS hypoperfusion was shown to be colocalized with microglia. Based on the above analysis, PU.1 plays a key regulatory role in microglial activation induced by CCH. And the transcriptome and epigenomic data presented in this study can help identify potential targets for future research exploring chronic hypoperfusion-induced brain injury.

Latest advances and clinical application prospects of resveratrol therapy for neurocognitive disorders

Neurocognitive disorders, such as Alzheimer's disease, vascular dementia, and postoperative cognitive dysfunction, are non-psychiatric brain syndromes in which a significant decline in cognitive function causes great trauma to the mental status of the patient. The lack of effective treatments for neurocognitive disorders imposes a considerable burden on society, including a substantial economic impact. Over the past few decades, the identification of resveratrol, a natural plant compound, has provided researchers with an opportunity to formulate novel strategies for the treatment of neurocognitive disorders. This is because resveratrol effectively protects the brain of those with neurocognitive disorders by targeting some mechanisms such as inflammation and oxidative stress. This article reviews the status of recent research investigating the use of resveratrol for the treatment of different neurocognitive disorders. By examining the possible mechanisms of action of resveratrol and the shared mechanisms of different neurocognitive disorders, treatments for neurocognitive disorders may be further clarified.

A review of SaiLuoTong (MLC-SLT) development in vascular cognitive impairment and dementia

The dementia epidemic, attributed to aging populations, represents a growing socio-economic burden. It is estimated that in 2019 about 55 million people worldwide were living with dementia. With many possible causes of dementia and the possibility of mixed dementia combining Alzheimer's disease (AD) and vascular dementia the question is whether diagnostic uncertainty exists or whether diagnostic constructs based on single etiologies are incorrect. Vascular Cognitive Impairment and Dementia (VCID) designates the extent of cognitive dysfunctions from the most benign state to that of dementia, of vascular origin. We reviewed epidemiological, pathophysiological and clinical data on VCID with a focus on VaD, as well as key data on the development of a new therapeutic solution, SaiLuoTong (MLC-SLT). From documentary research executed on different web sources (PubMed, Clintrials.gov, Z-library and Google), our initial selection for the short review of VCID and VaD was based on keywords contained in each paragraph subtitles of this article with exclusion of publications in a language other than English or published before 2010. For the review of SaiLuoTong development, there was just the language exclusion criterion. Sorted by relevance and publication date, 47 references were selected from 140 shortlisted for review. With new evidence-based classification systems, vascular cognitive impairment was proposed as umbrella term covering all forms of cognitive deficits related to vascular causes. The scope of application expanded with the VCID which includes VaD and mixed pathologies. No drugs are approved for the treatment of VaD by major Western regulatory agencies, while some traditional Chinese medicines are registered in China. VCID treatment should have a dual focus: managing the underlying cerebrovascular disease and dementia symptoms. This is the objective set for the development of the MLC-SLT, the essential data of which are reviewed in detail. To strengthen VCID and VaD research, consensus groups should attempt to consolidate scattered local research initiatives into coordinated international programs. In two VaD clinical trials, MLC-SLT improved cognitive symptoms and activities of daily living, with good safety and potential disease-modifying effect. In a placebo-controlled study in 325 patients with mild to moderate VaD and randomized according to a delayed-start design, MLC-SLT demonstrated significant improvement in memory tests and performance in executive function tasks, expanding its place in the management of VCID. At week 26, changes in VADAS-cog scores (SD) from baseline were 23.25 (0.45) for MLC-SLT 180 mg bid), 23.05 (0.45) for MLC-SLT 120 mg bid (both p < 0.0001), and 20.57 (0.45) for placebo (p = 0.15). At week 52, differences between both groups MLC-SLT and placebo were 2.67 and 2.48, respectively (p < 0.0001), without significant difference between MLC-SLT groups.

Differential Effects of Aging on Regional Corpus Callosum Microstructure and the Modifying Influence of Pulse Pressure

The corpus callosum is composed of several subregions, distinct in cellular and functional organization. This organization scheme may render these subregions differentially vulnerable to the aging process. Callosal integrity may be further compromised by cardiovascular risk factors, which negatively influence white matter health. Here, we test for heterochronicity of aging, hypothesizing an anteroposterior gradient of vulnerability to aging that may be altered by the effects of cardiovascular health. In 174 healthy adults across the adult lifespan (mean age = 53.56 ± 18.90; range, 20-94 years old, 58.62% women), pulse pressure (calculated as participant's systolic minus diastolic blood pressure) was assessed to determine cardiovascular risk. A deterministic tractography approach via diffusion-weighted imaging was utilized to extract fractional anisotropy (FA), radial diffusivity (RD), and axial diffusivity (AD) from each of five callosal subregions, serving as estimates of microstructural health. General linear models tested the effects of age, hypertension, and pulse pressure on these cross-sectional metrics. We observed no significant effect of hypertensive diagnosis on callosal microstructure. We found a significant main effect of age and an age-pulse pressure interaction whereby older age and elevated pulse pressure were associated with poorer FA, AD, and RD. Age effects revealed nonlinear components and occurred along an anteroposterior gradient of severity in the callosum. This gradient disappeared when pulse pressure was considered. These results indicate that age-related deterioration across the callosum is regionally variable and that pulse pressure, a proxy of arterial stiffness, exacerbates this aging pattern in a large lifespan cohort.

Clinical trajectories preceding incident dementia up to 15 years before diagnosis: a large prospective cohort study

BACKGROUND

Dementia has a long prodromal stage with various pathophysiological manifestations; however, the progression of pre-diagnostic changes remains unclear. We aimed to determine the evolutional trajectories of multiple-domain clinical assessments and health conditions up to 15 years before the diagnosis of dementia.

METHODS

Data was extracted from the UK-Biobank, a longitudinal cohort that recruited over 500,000 participants from March 2006 to October 2010. Each demented subject was matched with 10 healthy controls. We performed logistic regressions on 400 predictors covering a comprehensive range of clinical assessments or health conditions. Their evolutional trajectories were quantified using adjusted odds ratios (ORs) and FDR-corrected p-values under consecutive timeframes preceding the diagnosis of dementia.

FINDINGS

During a median follow-up of 13.7 [Interquartile range, IQR 12.9-14.2] years until July 2022, 7620 subjects were diagnosed with dementia. In general, upon approaching the diagnosis, demented subjects witnessed worse functional assessments and a higher prevalence of health conditions. Associations up to 15 years preceding the diagnosis comprised declined physical strength (hand grip strength, OR 0.65 [0.63-0.67]), lung dysfunction (peak expiratory flow, OR 0.78 [0.76-0.81]) and kidney dysfunction (cystatin C, OR 1.13 [1.11-1.16]), comorbidities of coronary heart disease (OR 1.78 [1.67-1.91]), stroke (OR 2.34 [2.1-1.37]), diabetes (OR 2.03 [1.89-2.18]) and a series of mental disorders. Cognitive functions in multiple tests also demonstrate decline over a decade before the diagnosis. Inadequate activity (3-5 year, overall time of activity, OR 0.82 [0.73-0.92]), drowsiness (3-5 year, sleep duration, OR 1.13 [1.04-1.24]) and weight loss (0-5 year, weight, OR 0.9 [0.83-0.98]) only exhibited associations within five years before the diagnosis. In addition, serum biomarkers of enriched endocrine, dysregulations of ketones, deficiency of brand-chain amino acids and polyunsaturated fatty acids were found in a similar prodromal time window and can be witnessed as the last pre-symptomatic conditions before the diagnosis.

INTERPRETATION

Our findings present a comprehensive temporal-diagnostic landscape preceding incident dementia, which could improve selection for preventive and early disease-modifying treatment trials.

Association of vitamin D and cognition in people with type 2 diabetes: a systematic review

CONTEXT

There is a high prevalence of vitamin D deficiency and impaired cognitive function in people with type 2 diabetes mellitus (T2DM).

OBJECTIVE

To critically and systematically review the literature on the association between vitamin D status and cognitive performance in people with type 2 diabetes.

DATA SOURCES

This review was conducted according to PRISMA recommendations. MEDLINE, SCOPUS, the Cochrane Library, and Web of Science databases were searched using the terms "Diabetes Mellitus, Type 2", "Cognitive Function", and "Vitamin D".

DATA EXTRACTION

Eight observational and 1 randomized study were included, containing data of 14 648 adult and elderly individuals (19-74 y). All extracted data were compiled, compared, and critically analyzed.

DATA ANALYSIS

There is no strong evidence that lower serum concentrations of vitamin D and vitamin D-binding protein are associated with worsening cognitive function in individuals with T2DM. Vitamin D supplementation (12 wk) improved the scores of some executive functioning tests, although there was no difference between low doses (5000 IU/wk) and high doses (50 000 IU/wk).

CONCLUSIONS

There is no high-quality evidence demonstrating an association between vitamin D status and cognitive function, or clinical benefits on cognition from vitamin D supplementation in individuals with T2DM. Future studies are needed. Systematic Review Registration: PROSPERO registration no. CRD42021261520.

Extracellular vesicles mediate inflammasome signaling in the brain and heart of Alzheimer's disease mice

Introduction

Alzheimer's disease (AD) is an inflammatory neurodegenerative disease characterized by memory loss and cognitive impairment that worsens over time. AD is associated with many comorbidities, including cardiovascular disease that are associated with poorer outcomes. Comorbidities, especially heart disease and stroke, play a significant role in the demise of AD patients. Thus, it is important to understand how comorbidities are linked to AD. We have previously shown that extracellular vesicle (EV)-mediated inflammasome signaling plays an important role in the pathogenesis of brain injury and acute lung injury after traumatic brain injury.

Methods

We analyzed the cortical, hippocampal, ventricular, and atrial protein lysates from APP/PS1 mice and their respective controls for inflammasome signaling activation. Additionally, we analyzed serum-derived EV for size, concentration, and content of inflammasome proteins as well as the EV marker CD63. Finally, we performed conditioned media experiments of EV from AD patients and healthy age-matched controls delivered to cardiovascular cells in culture to assess EV-induced inflammation.

Results

We show a significant increase in Pyrin, NLRP1, caspase-1, and ASC in the brain cortex whereas caspase-8, ASC, and IL-1β were significantly elevated in the heart ventricles of AD mice when compared to controls. We did not find significant differences in the size or concentration of EV between groups, but there was a significant increase of caspase-1 and IL-1β in EV from AD mice compared to controls. In addition, conditioned media experiments of serum-derived EV from AD patients and age-matched controls delivered to cardiovascular cells in culture resulted in inflammasome activation, and significant increases in TNF-α and IL-2.

Conclusion

These results indicate that EV-mediated inflammasome signaling in the heart may play a role in the development of cardiovascular diseases in AD patients.

Trends in Cognitive Function Before and After Diabetes Onset: The China Health and Retirement Longitudinal Study

BACKGROUND AND OBJECTIVES

Individuals with prevalent diabetes were known to have a higher risk of dementia and lower cognitive function. However, trends of cognitive function before diabetes and in the short term after new-onset diabetes remain unclear.

METHODS

This study included participants without baseline diabetes from the China Health and Retirement Longitudinal Study. Cognitive tests were conducted at baseline (wave 1) and at least one time from wave 2 (2013) to wave 4 (2018). Cognitive function was assessed using a global cognition score which was the summary measure of 4 cognitive tests. A linear mixed model was constructed to fit the trends in cognitive function before and after diabetes onset and the trends among nondiabetes. The threshold of statistical significance was p < 0.05.

RESULTS

During the 7-year follow-up, 1,207 (9.7% of 12,422, 59.1 ± 8.6 years, 39.9% male participants) participants developed new-onset diabetes. The cognitive function of both the without diabetes group and the diabetes group declined annually during the follow-up. The annual decline rate of the diabetes group before diabetes onset was similar to that of the without diabetes group during the whole follow-up period. After diabetes onset, participants experienced statistically significant faster cognitive declines in global cognition (-0.023 SD/year; 95% CI -0.043 to -0.004; p = 0.019) and visuospatial abilities test (-0.036 SD/year; -0.061 to -0.011; p = 0.004), but not in tests of episodic memory (-0.018 SD/year; -0.041 to 0.004; p = 0.116), attention and calculation (-0.017 SD/year; -0.037 to 0.003; p = 0.090), or orientation (0.001 SD/year; -0.018 to 0.020; p = 0.894), compared with the cognitive slope before diabetes. In subgroup analysis, compared with those who developed diabetes between 45-54 years, those developing diabetes older (55-64 years, p for interaction = 0.701; 65-74 years, p for interaction = 0.996) did not demonstrate different rates of global cognitive decline after diabetes.

DISCUSSION

Individuals experienced faster rate of cognitive decline in a few years after diabetes onset, but not during the prediabetes period. Age did not modify the effect of diabetes on postdiabetes cognitive decline. Efforts in eliminating the adverse impacts on cognition should be started on diagnosis of diabetes.

The role of the Pin1-cis P-tau axis in the development and treatment of vascular contribution to cognitive impairment and dementia and preeclampsia

Tauopathies are neurodegenerative diseases characterized by deposits of abnormal Tau protein in the brain. Conventional tauopathies are often defined by a limited number of Tau epitopes, notably neurofibrillary tangles, but emerging evidence suggests structural heterogeneity among tauopathies. The prolyl isomerase Pin1 isomerizes cis P-tau to inhibit the development of oligomers, tangles and neurodegeneration in multiple neurodegenerative diseases such as Alzheimer's disease, traumatic brain injury, vascular contribution to cognitive impairment and dementia (VCID) and preeclampsia (PE). Thus, cis P-tau has emerged as an early etiological driver, blood marker and therapeutic target for multiple neurodegenerative diseases, with clinical trials ongoing. The discovery of cis P-tau and other tau pathologies in VCID and PE calls attention for simplistic classification of tauopathy in neurodegenerative diseases. These recent advances have revealed the exciting novel role of the Pin1-cis P-tau axis in the development and treatment of vascular contribution to cognitive impairment and dementia and preeclampsia.

Enriched Environment Inhibits Neurotoxic Reactive Astrocytes via JAK2-STAT3 to Promote Glutamatergic Synaptogenesis and Cognitive Improvement in Chronic Cerebral Hypoperfusion Rats

Chronic cerebral hypoperfusion (CCH) is a primary contributor to cognitive decline in the elderly. Enriched environment (EE) is proved to improve cognitive function. However, mechanisms involved remain unclear. The purpose of the study was exploring the mechanisms of EE in alleviating cognitive deficit in rats with CCH. To create a rat model of CCH, 2-vessel occlusion (2-VO) surgery was performed. All rats lived in standard or enriched environments for 4 weeks. Cognitive function was assessed using the novel object recognition test and Morris water maze test. The protein levels of glutamatergic synapses, neurotoxic reactive astrocytes, reactive microglia, and JAK2-STAT3 signaling pathway were measured using Western blot. The mRNA levels of synaptic regulatory factors, C1q, TNF-α, and IL-1α were identified using quantitative PCR. Immunofluorescence was used to detect glutamatergic synapses, neurotoxic reactive astrocytes, and reactive microglia, as well as the expression of p-STAT3 in astrocytes in the hippocampus. The results demonstrated that the EE mitigated cognitive impairment in rats with CCH and enhanced glutamatergic synaptogenesis. EE also inhibited the activation of neurotoxic reactive astrocytes. Moreover, EE downregulated microglial activation, levels of C1q, TNF-α and IL-1α and phosphorylation of JAK2 and STAT3. Our results suggest that inhibition of neurotoxic reactive astrocytes may be one of the mechanisms by which EE promotes glutamatergic synaptogenesis and improves cognitive function in rats with CCH. The downregulation of reactive microglia and JAK2-STAT3 signaling pathway may be involved in this process.

Point prevalence of epilepsy in dementia: A "real-world" estimate

OBJECTIVE

Several studies have demonstrated a higher frequency of seizures and epilepsy in Alzheimer's disease and other forms of dementia as compared with healthy elderly individuals. However, incidence and prevalence of epilepsy in the general population of dementia are unknown since most previous studies were performed in secondary-tertiary referral centres. In addition, all prior studies but one provided "period" rather than "point" prevalence estimates.

METHODS

We assessed point prevalence estimate of epileptic manifestations requiring antiepileptic medication in patients Alzheimer's disease, vascular dementia, and fronto-temporal dementia from a secondary clinical setting.

RESULTS

Point prevalence estimates were 6.4% (95% CI: 1.5 to 11.3) in Alzheimer's disease, 8.9% (95% CI: 1.4 to 16.4), in vascular dementia, and 6% (95% CI: 1.3 to 10.7) in fronto-temporal dementia, rates that were greater than those observed in the healthy elderly population. Regardless of the etiology of dementia, epilepsy was characterized by unprovoked seizures that lacked distinguishing clinical features.

SIGNIFICANCE

These findings support epilepsy as part of the spectrum of dementia. The similar point prevalence of definite epilepsy requiring AED treatment in Alzheimer's disease and non Alzheimer dementias raised the possibility of similar underlying mechanism of epileptogenesis. Although this was not a population-based study, accurate point prevalence data from clinic setting would be important to better define the burden of epilepsy in dementia and the demands on health services to manage the condition.

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.