Inhibition of histone methyltransferase promotes cognition and mitochondrial function in vascular dementia model.

Vascular dementia (VD) is one of the most common forms of dementia worldwide, characterized by problems with reasoning, planning, judgment, and memory. This study investigated the effect of a histone methyltransferase inhibitor on cognition and mitochondrial function in a rat model of VD, as well as its impact on H2O2-induced neurotoxicity in hippocampal neuronal cultures. In the in vivo experiments, VD was induced by bilateral occlusion of the common carotid artery (CCA) for one month. The histone methyltransferase inhibitor, BIX01294, was administered intracerebroventricularly for one month (22.5 µg.kg-1 three times/week). On day 30, behavioral tests, including the novel object recognition test and elevated plus maze test, were conducted. Mitochondrial enzyme activities, including aconitase, α-ketoglutarate dehydrogenase (α-KG), complex I, and complex IV, were evaluated in the hippocampus of rats following CCA ligation. In the in vitro experiments, the effect of BIX01294 (50-600 µM) on H2O2 (400 µM)-induced cytotoxicity in hippocampal neuronal cells was assessed using the MTT assay. Flow cytometry was performed to evaluate apoptosis. Our findings revealed that BIX01294 effectively improved memory function, Krebs cycle enzyme activity, and mitochondrial function in the rat model of VD. Moreover, in vitro results showed that BIX01294 at a concentration of 100 µM significantly reversed the cytotoxicity and apoptosis induced by H2O2 in neuronal cells. These findings suggest that BIX01294 may have the potential to improve VD complications by reducing oxidative stress and inhibiting histone methylation.

Tongqiao Yizhi granule repress the nuclear factor kappa-b/nucleotide oligomerization domain-like receptors 3/caspase-1 pyroptosis pathway in the hippocampus to counter vascular dementia in rats.

OBJECTIVE: To explore the mechanism by which Tongqiao Yizhi granule (, TQYZKL) intervenes pyroptosis to treat vascular dementia (VaD) in a rat model. METHODS: The rat model of VaD was established by two-vessel occlusion (2VO). The rats were randomly divided into Sham group, Model group, Nimodipine group, TQYZKL (6.2 g?kg-1?d-1), TQYZKL (12.4 g?kg-1?d-1), TQYZKL (24.8 g?kg-1?d-1). The Morris water maze (MWM) test was carried out to test the learning and memory function; Hematoxylin-eosin staining and transmission electron microscopy (TEM) to observe the pathological damage in the hippocampus; Tunel fluorescence staining to detect neuronal pyroptosis in the hippocampus. The expression levels of pyroptosis-related proteins, namely Golgi peripheral membrane protein p65 (P65), nucleotide oligomerization domain-like receptors 3 (NLRP3), caspase-1 and Gasdermin D (GSDMD), were detected using Western blotting and reverse transcription polymerase chain reaction. Moreover, the serum levels of interleukin-1ß (IL-1ß) and interleukin-18 (IL-18) were determined through the enzyme-linked immunosorbent assay. RESULTS: The study revealed that TQYZKL effectively improved the ability of VaD ratsto learn and memorize, relieved the pathological damage in the hippocampus, restored neuronal morphology, and reduced the expression of pyroptosis-related proteins P65, NLRP3, caspase-1, GSDMD-N, IL-18 and IL-1ß (P < 0.05). CONCLUSION: TQYZKL inhibits neuronal pyroptosis in the hippocampus of VaD rats by regulating nuclear factor kappa-B/NLRP3/caspase-1 signaling pathway, thus exerting a therapeutic effect on VaD in the rats.

Zinc, Copper, and Calcium: A Triangle in the Synapse for the Pathogenesis of Vascular-Type Senile Dementia.

Zinc (Zn) and copper (Cu) are essential for normal brain functions. In particular, Zn and Cu are released to synaptic clefts during neuronal excitation. Synaptic Zn and Cu regulate neuronal excitability, maintain calcium (Ca) homeostasis, and play central roles in memory formation. However, in pathological conditions such as transient global ischemia, excess Zn is secreted to synaptic clefts, which causes neuronal death and can eventually trigger the pathogenesis of a vascular type of senile dementia. We have previously investigated the characteristics of Zn-induced neurotoxicity and have demonstrated that low concentrations of Cu can exacerbate Zn neurotoxicity. Furthermore, during our pharmacological approaches to clarify the molecular pathways of Cu-enhanced Zn-induced neurotoxicity, we have revealed the involvement of Ca homeostasis disruption. In the present review, we discuss the roles of Zn and Cu in the synapse, as well as the crosstalk between Zn, Cu, and Ca, which our study along with other recent studies suggest may underlie the pathogenesis of vascular-type senile dementia.

[Mechanism of electroacupuncture for vascular dementia based on proteomics].

OBJECTIVE: To explore the potential mechanism of electroacupuncture (EA) for vascular dementia (VD) using tandem mass tag (TMT) quantitative proteomics technology. METHODS: Among 80 male SPF SD rats, 78 rats which met the selection criteria through the Morris water maze test were selected and randomly divided into a sham surgery group (18 rats) and a surgery group (60 rats). VD model was established by four-vessel occlusion (4-VO) method in the surgery group, and 36 rats with successful modeling were randomly assigned to a model group (18 rats) and an EA group (18 rats). Each group was further divided into three subgroups based on intervention duration, with each subgroup containing 6 rats. Seven days after model establishment, the EA group received EA intervention at left and right "Sishencong" (EX-HN 1) and bilateral "Fengchi" (GB 20), with continuous wave at a frequency of 2 Hz and current intensity of 1 mA, daily for 30 min, with subgroups receiving EA for 7, 14, or 21 d respectively. Cognitive function before and after interventions was assessed using Morris water maze. Proteomic analysis was conducted on the optimal EA subgroup and corresponding sham surgery and model subgroups, identifying differentially expressed proteins and analyzing them through bioinformatics. Differentially expressed target proteins was performed using parallel reaction monitoring (PRM) and Western blot techniques. RESULTS: Compared to the sham surgery group, the model group exhibited prolonged escape latency and reduced number of platform crossings (P<0.01); compared with model group, the EA group showed reductions in escape latency and increased platform crossings after 7, 14, and 21 days of intervention (P<0.01, P<0.05). Compared to the 7 and 14-day intervention, the rats in the EA group of 21-day intervention showed the most significant improvements in reductions of escape latency and increased platform crossings (P<0.01, P<0.05), and was selected for further proteomic, PRM analyses, and Western blot validation. Compared to the sham surgery group, the model group displayed 71 differentially expressed proteins, with 50 up-regulated and 21 down-regulated proteins; compared to the model group, the EA group had 54 differentially expressed proteins, with 30 up-regulated and 24 down-regulated proteins. Functional enrichment and clustering analyses indicated that these proteins were primarily associated with cellular processes, metabolic processes, phagocytosis recognition, immune response, and regulation of extracellular matrix, etc. Enrichment was observed in the mammalian target of rapamycin (mTOR) signaling pathway and neurotrophic factors signaling pathways, involving glycogen synthase kinase 3ß (GSK3ß) and mitogen-activated protein kinase kinase 2 (Map2k2), with PRM and Western blot findings consistent with the proteomic results. Which meant that compared with the model group, the protein expression of GSK3ß and Map2k2 of hippocampus was increased in the EA group (P<0.01, P<0.05). CONCLUSION: EA at "Sishencong" (EX-HN 1) and "Fengchi" (GB 20) could improve cognitive function in VD rats, with the mechanism involving multiple targets and pathways, potentially related to GSK3ß, Map2k2 proteins, and the mTOR and neurotrophic factor signaling pathways.

Hippocampus under Pressure: Molecular Mechanisms of Development of Cognitive Impairments in SHR Rats.

Data from clinical trials and animal experiments demonstrate relationship between chronic hypertension and development of cognitive impairments. Here, we review structural and biochemical alterations in the hippocampus of SHR rats with genetic hypertension, which are used as a model of essential hypertension and vascular dementia. In addition to hypertension, dysfunction of the hypothalamic-pituitary-adrenal system observed in SHR rats already at an early age may be a key factor of changes in the hippocampus at the structural and molecular levels. Global changes at the body level, such as hypertension and neurohumoral dysfunction, are associated with the development of vascular pathology and impairment of the blood-brain barrier. Changes in multiple biochemical glucocorticoid-dependent processes in the hippocampus, including dysfunction of steroid hormones receptors, impairments of neurotransmitter systems, BDNF deficiency, oxidative stress, and neuroinflammation are accompanied by the structural alterations, such as cellular signs of neuroinflammation micro- and astrogliosis, impairments of neurogenesis in the subgranular neurogenic zone, and neurodegenerative processes at the level of synapses, axons, and dendrites up to the death of neurons. The consequence of this is dysfunction of hippocampus, a key structure of the limbic system necessary for cognitive functions. Taking into account the available results at various levels starting from the body and brain structure (hippocampus) levels to molecular one, we can confirm translational validity of SHR rats for modeling mechanisms of vascular dementia.

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.

Taohong Siwu decoction alleviates cognitive impairment by suppressing endoplasmic reticulum stress and apoptosis signaling pathway in vascular dementia rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Taohong Siwu Decoction (TSD), a classic traditional Chinese medicine formula, is used for the treatment of vascular diseases, including vascular dementia (VD). However, the mechanisms remain unclear. AIM OF STUDY: This study aimed to investigate whether TSD has a positive effect on cognitive impairment in VD rats and to confirm that the mechanism of action is related to the Endoplasmic Reticulum stress (ERs) and cell apoptosis signaling pathway. MATERIALS AND METHODS: A total of 40 male adult Sprague-Dawley rats were divided into four groups: sham-operated group (Sham), the two-vessel occlusion group (2VO), the 2VO treated with 4.5 g/kg/d TSD group (2VO + TSD-L), the 2VO treated with 13.5 g/kg/d TSD group (2VO + TSD-H). The rats underwent either 2VO surgery or sham surgery. Postoperative TSD treatment was given for 4 consecutive weeks. Behavioral tests were initiated at the end of gastrulation. Open-field test (OFT) was used to detect the activity level. The New Object Recognition test (NOR) was used to test long-term memory. The Morris water maze (MWM) test was used to examine the foundation of spatial learning and memory. As a final step, the hippocampus was taken for molecular testing. The protein levels of GRP78 (Bip), p-PERK, PERK, IRE1α, p-IRE1α, ATF6, eIF2α, p-eIF2α, ATF4, XBP1, Bcl-2 and Bax were determined by Western blot. Immunofluorescence visualizes molecular expression. RESULTS: In the OFT, residence time in the central area was significantly longer in both TSD treatment groups compared to the 2VO group. In the NOR, the recognition index was obviously elevated in both TSD treatment groups. The 2VO group had a significantly longer escape latency and fewer times in crossing the location of the platform compared with the Sham group in MWM. TSD treatment reversed this notion. Pathologically, staining observations confirmed that TSD inhibited hippocampal neuronal loss and alleviated the abnormal reduction of the Nissl body. In parallel, TUNEL staining illustrated that TSD decelerated neuronal apoptosis. Western Blot demonstrated that TSD reduces the expression of ERs and apoptotic proteins. CONCLUSION: In this study, the significant ameliorative effect on cognitive impairment of TSD has been determined by comparing the behavioral data of the 4 groups of rats. Furthermore, it was confirmed that this effect of TSD was achieved by suppressing the ERs-mediated apoptosis signaling pathway.

Computerized decision support is an effective approach to select memory clinic patients for amyloid-PET.

BACKGROUND: The use of amyloid-PET in dementia workup is upcoming. At the same time, amyloid-PET is costly and limitedly available. While the appropriate use criteria (AUC) aim for optimal use of amyloid-PET, their limited sensitivity hinders the translation to clinical practice. Therefore, there is a need for tools that guide selection of patients for whom amyloid-PET has the most clinical utility. We aimed to develop a computerized decision support approach to select patients for amyloid-PET. METHODS: We included 286 subjects (135 controls, 108 Alzheimer's disease dementia, 33 frontotemporal lobe dementia, and 10 vascular dementia) from the Amsterdam Dementia Cohort, with available neuropsychology, APOE, MRI and [18F]florbetaben amyloid-PET. In our computerized decision support approach, using supervised machine learning based on the DSI classifier, we first classified the subjects using only neuropsychology, APOE, and quantified MRI. Then, for subjects with uncertain classification (probability of correct class (PCC) < 0.75) we enriched classification by adding (hypothetical) amyloid positive (AD-like) and negative (normal) PET visual read results and assessed whether the diagnosis became more certain in at least one scenario (PPC≥0.75). If this was the case, the actual visual read result was used in the final classification. We compared the proportion of PET scans and patients diagnosed with sufficient certainty in the computerized approach with three scenarios: 1) without amyloid-PET, 2) amyloid-PET according to the AUC, and 3) amyloid-PET for all patients. RESULTS: The computerized approach advised PET in n = 60(21%) patients, leading to a diagnosis with sufficient certainty in n = 188(66%) patients. This approach was more efficient than the other three scenarios: 1) without amyloid-PET, diagnostic classification was obtained in n = 155(54%), 2) applying the AUC resulted in amyloid-PET in n = 113(40%) and diagnostic classification in n = 156(55%), and 3) performing amyloid-PET in all resulted in diagnostic classification in n = 154(54%). CONCLUSION: Our computerized data-driven approach selected 21% of memory clinic patients for amyloid-PET, without compromising diagnostic performance. Our work contributes to a cost-effective implementation and could support clinicians in making a balanced decision in ordering additional amyloid PET during the dementia workup.

Apelin receptor dimer: Classification, future prospects, and pathophysiological perspectives.

Apelin receptor (APJ), a member of the class A family of G protein-coupled receptor (GPCR), plays a crucial role in regulating cardiovascular and central nervous systems function. APJ influences the onset and progression of various diseases such as hypertension, atherosclerosis, and cerebral stroke, making it an important target for drug development. Our preliminary findings indicate that APJ can form homodimers, heterodimers, or even higher-order oligomers, which participate in different signaling pathways and have distinct functions compared with monomers. APJ homodimers can serve as neuroprotectors against, and provide new pharmaceutical targets for vascular dementia (VD). This review article aims to summarize the structural characteristics of APJ dimers and their roles in physiology and pathology, as well as explore their potential pharmacological applications.

Identification of toll-like receptor 2 as a key regulator of neuronal apoptosis in vascular dementia by bioinformatics analysis and experimental validation.

BACKGROUND: Vascular dementia (VaD), the second most prevalent type of dementia, lacks a well-defined cause and effective treatment. Our objective was to utilize bioinformatics analysis to discover the fundamental disease-causing genes and pathological mechanisms in individuals diagnosed with VaD. METHODS: To identify potential pathogenic genes associated with VaD, we conducted weighted gene co-expression network analysis (WGCNA), differential expression analysis, and protein-protein interaction (PPI) analysis. The exploration of potential biological mechanisms involved the utilization of Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analysis. Moreover, a bilateral common carotid artery stenosis (BCAS) mouse model of VaD was established, and the expression of the hub gene, its relationship with cognitive function and its potential pathogenic mechanism were verified by cognitive behavior tests, cerebral blood flow measurement, Western blotting, and immunofluorescence experiments. RESULTS: This study identified 293 DEGs from the brain cortex of VaD patients and healthy controls, among these genes, the Toll-like receptor 2 (TLR2) gene was identified as hub gene, and it was associated with the apoptosis-related pathway PI3K/AKT.The BCAS model demonstrated that the use of TLR2 inhibitors greatly enhanced the cognitive function of the mice (p < 0.05). Additionally, there was a notable decrease in the number of apoptotic cells in the brain cortex of the mice (p < 0.01). Moreover, significant alterations in the levels of proteins related to the PI3K/AKT pathway and cleaved-caspase3 proteins were detected (p < 0.05). CONCLUSIONS: TLR2 plays a role in the pathophysiology of VaD by enhancing the neuronal apoptotic pathway, suggesting it could be a promising therapeutic target.

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.

Hypercholesterolemia and the Increased Risk of Vascular Dementia: a Cholesterol Perspective.

PURPOSE OF REVIEW: Vascular dementia (VaD) is the second most prevalent type of dementia after Alzheimer's disease.Hypercholesterolemia may increase the risk of dementia, but the association between cholesterol and cognitive function is very complex. From the perspective of peripheral and brain cholesterol, we review the relationship between hypercholesterolemia and increased risk of VaD and how the use of lipid-lowering therapies affects cognition. RECENT FINDINGS: Epidemiologic studies show since 1980, non-HDL-C levels of individuals has increased rapidly in Asian countries.The study has suggested that vascular risk factors increase the risk of VaD, such as disordered lipid metabolism. Dyslipidemia has been found to interact with chronic cerebral hypoperfusion to promote inflammation resulting in cognitive dysfunction in the brain.Hypercholesterolemia may be a risk factor for VaD. Inflammation could potentially serve as a link between hypercholesterolemia and VaD. Additionally, the potential impact of lipid-lowering therapy on cognitive function is also worth considering. Finding strategies to prevent and treat VaD is critical given the aging of the population to lessen the load on society. Currently, controlling underlying vascular risk factors is considered one of the most effective methods of preventing VaD. Understanding the relationship between abnormal cholesterol levels and VaD, as well as discovering potential serum biomarkers, is important for the early prevention and treatment of VaD.

Inhibition of ADORA3 promotes microglial phagocytosis and alleviates chronic ischemic white matter injury.

BACKGROUND: Adenosine A3 receptor (ADORA3) belongs to the adenosine receptor families and the role of ADORA3 in vascular dementia (VaD) is largely unexplored. The present study sought to determine the therapeutic role of ADORA3 antagonist in a mouse model of VaD. METHODS: The GSE122063 dataset was selected to screen the differential expression genes and pathways between VaD patients and controls. A mouse model of bilateral carotid artery stenosis (BCAS) was established. The cognitive functions were examined by the novel object recognition test, Y maze test, and fear of conditioning test. The white matter injury (WMI) was examined by 9.4 T MRI, western blot, and immunofluorescence staining. The mechanisms of ADORA3-regulated phagocytosis by microglia were examined using qPCR, western blot, dual immunofluorescence staining, and flow cytometry. RESULTS: The expression of ADORA3 was elevated in brain tissues of VaD patients and ADORA3 was indicated as a key gene for VaD in the GSE122063. In BCAS mice, the expression of ADORA3 was predominantly elevated in microglia in the corpus callosum. ADORA3 antagonist promotes microglial phagocytosis to myelin debris by facilitating cAMP/PKA/p-CREB pathway and thereby ameliorates WMI and cognitive impairment in BCAS mice. The therapeutic effect of ADORA3 antagonist was partially reversed by the inhibition of the cAMP/PKA pathway. CONCLUSIONS: ADORA3 antagonist alleviates chronic ischemic WMI by modulating myelin clearance of microglia, which may be a potential therapeutic target for the treatment of VaD.

CCR2+ monocytes promote white matter injury and cognitive dysfunction after myocardial infarction.

Survivors of myocardial infarction are at increased risk for vascular dementia. Neuroinflammation has been implicated in the pathogenesis of vascular dementia, yet little is known about the cellular and molecular mediators of neuroinflammation after myocardial infarction. Using a mouse model of myocardial infarction coupled with flow cytometric analyses and immunohistochemistry, we discovered increased monocyte abundance in the brain after myocardial infarction, which was associated with increases in brain-resident perivascular macrophages and microglia. Myeloid cell recruitment and activation was also observed in post-mortem brains of humans that died after myocardial infarction. Spatial and single cell transcriptomic profiling of brain-resident myeloid cells after experimental myocardial infarction revealed increased expression of monocyte chemoattractant proteins. In parallel, myocardial infarction increased crosstalk between brain-resident myeloid cells and oligodendrocytes, leading to neuroinflammation, white matter injury, and cognitive dysfunction. Inhibition of monocyte recruitment preserved white matter integrity and cognitive function, linking monocytes to neurodegeneration after myocardial infarction. Together, these preclinical and clinical results demonstrate that monocyte infiltration into the brain after myocardial infarction initiate neuropathological events that lead to 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.

[Comparative characteristics of neuropsychological and neurometabolic changes in patients with Alzheimer's disease and vascular cognitive impairment]. / Sravnitel'naya kharakteristika neiropsikhologicheskikh i neirometabolicheskikh pokazatelei u patsientov s bolezn'yu Al'tsgeimera i sosudistymi kognitivnymi rasstroistvami.

OBJECTIVE: To investigate the pattern and connections of neuropsychological and metabolic indices in patients with cognitive disorders of Alzheimer's and vascular (subcortical-cortical) types of different severity. MATERIAL AND METHODS: A total of 177 patients were examined, including 85 patients with Alzheimer's disease (AD) and 92 patients with vascular cognitive impairment (VCI). All patients underwent complex neuropsychological examination; 18F-FDG PET was performed in 17 patients with AD and 15 patients with VCI. RESULTS: The greatest changes in patients with AD were noted in the mnestic sphere, and the indicators significantly differed from the results of the study of patients with VCI already at the pre-dementia stage. Neurodynamic and dysregulatory disorders prevailed in patients with VCI. Patients with AD showed bilateral symmetrical reduction of metabolic activity in the cortex of parietal and temporal lobes, often in combination with marked hypometabolism in the hippocampal region. In patients with VCI, there were areas of decreased brain tissue metabolism of different localization and size, mainly in the projection of the basal ganglia and in the prefrontal and parietal cortex, as well as in the cingulate gyrus, which indirectly confirms the mechanism of disconnection of subcortical and cortical structures. In AD, impaired metabolic activity in the hippocampal region correlated with impaired temporal and spatial orientation (ρ=-0.54, p<0.05), memory impairment (ρ=-0.71, p<0.005). Hypometabolism of the parietal lobe cortex was associated with total MMSE score (ρ=-0.8, p<0.001), 10-word test (ρ=-0.89, p<0.001 and ρ=-0.82, p<0.001), visual-spatial impairment (ρ=-0.64, p<0.01), categorical association test (ρ=-0.73, p<0.005). In patients with VCI, dysregulatory disorders correlated with hypometabolism in the thalamic projection (ρ=-0.56, p<0.05), prefrontal cortex (ρ=-0.64, p<0.05) and in the cingulate gyrus (anterior regions) (ρ=-0.53, p<0.05). CONCLUSION: The results indicate the presence of differences in cognitive impairment and cerebral metabolism in patients with AD and VCI.

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

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

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-1ß, 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.

Deciphering mitochondrial dysfunction: Pathophysiological mechanisms in vascular cognitive impairment.

Vascular cognitive impairment (VCI) encompasses a range of cognitive deficits arising from vascular pathology. The pathophysiological mechanisms underlying VCI remain incompletely understood; however, chronic cerebral hypoperfusion (CCH) is widely acknowledged as a principal pathological contributor. Mitochondria, crucial for cellular energy production and intracellular signaling, can lead to numerous neurological impairments when dysfunctional. Recent evidence indicates that mitochondrial dysfunction-marked by oxidative stress, disturbed calcium homeostasis, compromised mitophagy, and anomalies in mitochondrial dynamics-plays a pivotal role in VCI pathogenesis. This review offers a detailed examination of the latest insights into mitochondrial dysfunction within the VCI context, focusing on both the origins and consequences of compromised mitochondrial health. It aims to lay a robust scientific groundwork for guiding the development and refinement of mitochondrial-targeted interventions for VCI.

Modulation of the Circadian Rhythm and Oxidative Stress as Molecular Targets to Improve Vascular Dementia: A Pharmacological Perspective.

The circadian rhythms generated by the master biological clock located in the brain's hypothalamus influence central physiological processes. At the molecular level, a core set of clock genes interact to form transcription-translation feedback loops that provide the molecular basis of the circadian rhythm. In animal models of disease, a desynchronization of clock genes in peripheral tissues with the central master clock has been detected. Interestingly, patients with vascular dementia have sleep disorders and irregular sleep patterns. These alterations in circadian rhythms impact hormonal levels, cardiovascular health (including blood pressure regulation and blood vessel function), and the pattern of expression and activity of antioxidant enzymes. Additionally, oxidative stress in vascular dementia can arise from ischemia-reperfusion injury, amyloid-beta production, the abnormal phosphorylation of tau protein, and alterations in neurotransmitters, among others. Several signaling pathways are involved in the pathogenesis of vascular dementia. While the precise mechanisms linking circadian rhythms and vascular dementia are still being studied, there is evidence to suggest that maintaining healthy sleep patterns and supporting proper circadian rhythm function may be important for reducing the risk of vascular dementia. Here, we reviewed the main mechanisms of action of molecular targets related to the circadian cycle and oxidative stress in vascular dementia.