Bioinformatic Identification of Signaling Pathways and Hub Genes in Vascular Dementia.

BACKGROUND: Vascular dementia (VaD) is a prevalent neurodegenerative disease characterized by cognitive impairment due to cerebrovascular factors, affecting a significant portion of the aging population and highlighting the critical need to understand specific targets and mechanisms for effective prevention and treatment strategies. We aimed to identify pathways and crucial genes involved in the progression of VaD through bioinformatics analysis and subsequently validate these findings. METHODS: We conducted differential expression analysis, Weighted Gene Co-expression Network Analysis (WGCNA), Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, and Protein-Protein Interaction (PPI) analysis. We utilized pheochromocytoma 12 (PC12) cells to create an in vitro oxygen-glucose deprivation (OGD) model. We investigated the impact of overexpression and interference of adrenoceptor alpha 1D (ADRA1D) on OGD PC12 cells using TdT-mediated dUTP nick-end labeling (TUNEL), reverse transcription-quantitative polymerase chain reaction (RT-qPCR), western blot (WB), and Fluo-3-pentaacetoxymethyl ester (Fluo-3 AM) analysis. RESULTS: We found 187 differentially expressed genes (DEGs) in the red module that were strongly associated with VaD and were primarily enriched in vasoconstriction, G protein-coupled amine receptor activity, and neuroactive ligand-receptor interaction, mitogen-activated protein kinase (MAPK) signaling pathway, and cell adhesion. Among these pathways, we identified ADRA1D as a gene shared by vasoconstriction, G protein-coupled amine receptor activity, and neuroactive ligand-receptor interaction. The TUNEL assay revealed a significant decrease in PC12 cell apoptosis with ADRA1D overexpression (p < 0.01) and a significant increase in apoptosis upon silencing ADRA1D (p < 0.01). RT-qPCR and WB analysis revealed elevated ADRA1D expression (p < 0.001) and decreased phospholipase C beta (PLCß) and inositol 1,4,5-trisphosphate receptor (IP3R) expression (p < 0.05) with ADRA1D overexpression. Moreover, the Fluo-3 AM assessment indicated significantly lower intracellular Ca2+ levels with ADRA1D overexpression (p < 0.001). Conversely, interference with ADRA1D yielded opposite results. CONCLUSION: Our study provides a new perspective on the pathogenic mechanisms of VaD and potential avenues for therapeutic intervention. The results highlight the role of ADRA1D in modulating cellular responses to OGD and VaD, suggesting its potential as a target for VaD treatment.

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.

Analysis of endothelial gene polymorphisms in Spanish patients with vascular dementia and Alzheimer´s disease.

There is increasing evidence for the involvement of blood-brain barrier (BBB) in vascular dementia (VaD) and Alzheimer´s disease (AD) pathogenesis. However, the role of endothelial function-related genes in these disorders remains unclear. We evaluated the association of four single-nucleotide polymorphisms (VEGF, VEGFR2 and NOS3) with diagnosis and rate of cognitive decline in AD and VaD in a Spanish case-control cohort (150 VaD, 147 AD and 150 controls). Participants carrying -604AA genotype in VEGFR2 (rs2071559) were less susceptible to VaD after multiple testing. Further analysis for VaD subtype revealed a significant difference between small-vessel VaD patients and controls, but not for large-vessel VaD patients. In addition, -2578A and -460C alleles in VEGF (rs699947 and rs833061) showed to decrease the risk of AD, whereas NOS3 (rs1799983) influenced disease progression. Our study supports previous findings of a deleterious effect of VEGFR2 reduced expression on small-vessel disease, but not on large-vessel disease; as well as a detrimental effect of down-regulating VEGF and eNOS in AD, affecting vascular permeability and neuronal survival. These data highlight the relevance of endothelial function and, therefore, BBB in both VaD and AD.

[Effect of moxibustion on inositol requiring enzyme 1 / X-box binding protein 1 pathway in hippocampal CA1 region of rats with vascular dementia].

OBJECTIVE: To observe the effect of moxibustion at Governor Vessel acupoints on inositol requiring enzyme 1 （IRE1） / X-box binding protein 1 （XBP1） pathway in hippocampal CA1 region of rats with vascular dementia （VD）, so as to explore its mechanisms in the treatment of VD. METHODS: Male SD rats were randomly divided into normal, sham operation, model, moxibustion （Moxi） and medication groups （n=12）. The VD model was established by permanent ligation of bilateral common carotid arteries. For rats of the Moxi group, mild moxibustion was given to "Baihui" （GV20）, "Dazhui" （GV14） and "Fengfu" （GV16） for 20 min each point, once a day for consecutive 6 days per week, for a total of 4 weeks. For rats of the medication group, intragastric perfusion of nimodipine was given 3 times each day with total dose of 2 mg•kg-1•d-1 for 4 weeks. Morris water maze test was used to detect the learning and memory ability of rats before and after modeling as well as after intervention. The apoptosis rate of nerve cells in hippocampal CA1 region was detected by TUNEL staining. The proteins and mRNA expression levels of IRE1, XBP1, B-cell lymphoma/leukemia-2 （Bcl-2）, Bcl-2 associated X protein （Bax） in hippocampal CA1 region were detected by Western blot and real-time quantitative PCR, respectively. RESULTS: Compared with the sham operation group, the average escape latency was significantly prolonged （P<0.01）, the number of times crossing the original platform was significantly reduced （P<0.01）, the apoptosis rate of nerve cells in hippocampal CA1 region was significantly increased （P<0.01）, the proteins and mRNA expression levels of IRE1, XBP1 and Bax were significantly increased （P<0.01）, and the expression levels of Bcl-2 protein and mRNA were significantly decreased （P<0.01） in rats of the model group. After treatment, compared with the model group, the average escape latency was significantly shortened （P<0.01）, the number of times crossing the original platform was increased （P<0.05）, the apoptosis rate of nerve cells in hippocampal CA1 region was significantly decreased （P<0.01）, the protein and mRNA expression levels of IRE1, XBP1 and Bax were decreased （P<0.05, P<0.01）, and the expression levels of Bcl-2 protein and mRNA were increased （P<0.05, P<0.01） in rats of the Moxi group and medication group. There was no significant difference in the above indexes between the Moxi group and the medication group. CONCLUSION: Moxibustion at the acupoints of Governor Vessel can improve the cognitive function of VD rats, and its mechanism may be related to regulating IRE1/XBP1 pathway, inhibiting the release of pro-apoptotic protein Bax, increasing the expression of anti-apoptotic protein Bcl-2, and thus inhibiting the apoptosis of hippocampal nerve cells.

["Huayu Tongluo" moxibustion improves learning-memory ability and promotes myelin regeneration by regulating Sonic Hedgehog signaling pathway in vascular dementia rats].

OBJECTIVE: To investigate the effect of "Huayu Tongluo" (resolving blood stagnation to dredge meridian-collaterals) moxibustion on remyelination and Sonic Hedgehog (Shh) signaling pathway in the corpus callosum of vascular dementia (VD) rats, so as to explore its mechanisms underlying improvement of VD. METHODS: Male Wistar rats were randomized into sham-operation, model, medication and moxibustion groups, with 12 rats in each group.The VD model was established by bilateral common carotid artery occlusion. Moxibustion was applied to "Shenting"(GV24), "Baihui"(GV20) and "Dazhui"(GV14) for 20 min once a day, 7 d as a treatment course, for 3 courses, with one day's rest between every two courses. Rats of the medication group were treated by gavage of 10 mg/kg of chloromastine solution once a day, and the course of treatment was the same as that of the moxibustion group. The rat's learning-memory ability was assessed by Morris water maze test (escape latency). The neurological deficits were evaluated by using Longa's scale.The mRNA and protein expressions of Shh and Gli1 in the corpus callosum were measured by quantitative real-time fluorescence PCR and Western blot, separately. The ultrastructure of the myelin sheath and myelinated axons was observed under transmission electron microscopy (TCM). RESULTS: Compared with the sham-operation group, the neurologic score and escape latency were significantly increased and prolonged (P<0.01), and the mRNA and protein expression levels of Shh and Gli1 and the number of myelinated axons were obviously decreased in the model group (P<0.01). In comparison with the model group, the escape latency was apparently shortened (P<0.05), while the mRNA and protein expression levels of Shh and Gli1 as well as the number of myelinated axons were strikingly increased in both moxibustion and medication groups (P<0.01). Results of TCM showed that in the model group, the arrangement of myelin coil structures was sparse and fuzzy, and some structures were bulged and disbanded. The oligodendrocytes were irregular, and the number of myelin sheath was rare. These situations were relatively milder in both moxibustion and medication groups. CONCLUSION: "Huayu Tongluo" moxibustion can promote the differentiation and maturation of oligodendrocyte precursor cells after cerebral ischemia by regulating the expressions of Shh and Gli1 in Shh signaling pathway, thus promoting the regeneration of cerebral white matter myelin sheaths in VD rats, which may contribute to improving learning-memory ability.

LncRNA MALAT1 Targets miR-9-3p to Upregulate SAP97 in the Hippocampus of Mice with Vascular Dementia.

Vascular dementia (VaD) is the second most common subtype of dementia, but the precise mechanism underlying VaD is not fully understood. Long non-coding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) can act as a key regulator in physiological and pathological processes, including neurological disorders, but whether it is correlated with VaD has not been elucidated. In this study, we established a mouse model of VaD by the transient bilateral common carotid artery occlusion surgery. As expected, the Morris water maze showed that VaD mice had significant deficits in spatial learning and memory. MALAT1 was elevated in the hippocampus of VaD mice. Additionally, we found that microRNA (miR)-9-3p was downregulated in the VaD hippocampus. By performing a dual-luciferase report assay, we verified the binding relationship between MALAT1 and miR-9-3p. Interestingly, synapse-associated protein-97 (SAP97), a well-known gene related to synaptic functions, was found upregulated in the hippocampus of VaD mice. In vitro experiments performed on hippocampal neurons demonstrated that miR-9-3p negatively regulated SAP97 expression. The downregulation of MALAT1 in hippocampal neurons increased miR-9-3p and reduced SAP97, whereas miR-9-3p inhibition rescued the MALAT1 downregulation-mediated SAP97 reduction. In conclusion, the present study reported the alterations in the expression levels of MALAT1, miR-9-3p, and SAP97 in the hippocampus of VaD mice, suggesting that MALAT1 targets miR-9-3p to upregulate SAP97 in the hippocampus of mice with VaD. This work will be helpful for understanding the molecular mechanisms of VaD.

Exosomal miR-132-3p from mesenchymal stromal cells improves synaptic dysfunction and cognitive decline in vascular dementia.

BACKGROUND/AIMS: Vascular dementia (VD) results in cognition and memory deficit. Exosomes and their carried microRNAs (miRs) contribute to the neuroprotective effects of mesenchymal stromal cells, and miR-132-3p plays a key role in neuron plasticity. Here, we investigated the role and underlying mechanism of MSC EX and their miR-132-3p cargo in rescuing cognition and memory deficit in VD mice. METHODS: Bilateral carotid artery occlusion was used to generate a VD mouse model. MiR-132-3p and MSC EX levels in the hippocampus and cortex were measured. At 24-h post-VD induction, mice were administered with MSC EX infected with control lentivirus (EXCon), pre-miR-132-3p-expressing lentivirus (EXmiR-132-3p), or miR-132-3p antago lentivirus (EXantagomiR-132-3p) intravenously. Behavioral and cognitive tests were performed, and the mice were killed in 21 days after VD. The effects of MSC EX on neuron number, synaptic plasticity, dendritic spine density, and Aß and p-Tau levels in the hippocampus and cortex were determined. The effects of MSC EX on oxygen-glucose deprivation (OGD)-injured neurons with respect to apoptosis, and neurite elongation and branching were determined. Finally, the expression levels of Ras, phosphorylation of Akt, GSK-3ß, and Tau were also measured. RESULTS: Compared with normal mice, VD mice exhibited significantly decreased miR-132-3p and MSC EX levels in the cortex and hippocampus. Compared with EXCon treatment, the infusion of EXmiR-132-3p was more effective at improving cognitive function and increasing miR-132-3p level, neuron number, synaptic plasticity, and dendritic spine density, while decreasing Aß and p-Tau levels in the cortex and hippocampus of VD mice. Conversely, EXantagomiR-132-3p treatment significantly decreased miR-132-3p expression in cortex and hippocampus, as well as attenuated EXmiR-132-3p treatment-induced functional improvement. In vitro, EXmiR-132-3p treatment inhibited RASA1 protein expression, but increased Ras and the phosphorylation of Akt and GSK-3ß, and decreased p-Tau levels in primary neurons by delivering miR-132-3p, which resulted in reduced apoptosis, and increased neurite elongation and branching in OGD-injured neurons. CONCLUSIONS: Our studies suggest that miR-132-3p cluster-enriched MSC EX promotes the recovery of cognitive function by improving neuronal and synaptic dysfunction through activation of the Ras/Akt/GSK-3ß pathway induced by downregulation of RASA1.

[Effect of electroacupuncture on gut microbiota and serum IL-1ß and IL-18 in rats with vascular dementia based on principle of "curing brain disorders by treating intestines"].

OBJECTIVE: To observe the effect of electroacupuncture (EA) of "Baihui"(GV20), "Dazhui"(GV14), "Shenshu" (BL23)and "Zusanli"(ST36) on the intestinal flora and serum interleukin (IL)-1ß and IL-18 contents in vascular dementia (VD) rats. METHODS: SD rats were randomized into sham operation, VD model, GV20+GV14+BL23 (EA-basic acupoints), and EA-basic acupoints+ST36 and EA-basic acupoints+probiotics groups (n=10 in each group). EA (10 Hz/50 Hz) was conducted for 30 min, once daily for 4 consecutive weeks. Rats of the EA-basic acupoints+probiotics received gavage of probiotics (2 mL/d containing 2.0×109 CFU of live bifidobacterium), once a day for 4 weeks, and those of the EA-basic acupoints and EA-basic acupoints+ST36 groups received gavage of the same dose of normal saline. The Morris water maze test was used to evalua-te the rats' lear-ning and memory ability before and after the treatment. The serum IL-1ß and IL-18 levels were determined by ELISA, and the histopathological changes of the intestinal mucosa were observed by H.E. staining. The ultrastructural changes of hippocampal neurons were observed by using transmission electron microscopy and 16S rDNA sequencing technique was used to analyze the composition of intestinal microbiome. RESULTS: Compared with the sham operation group, the escape latency, serum levels of IL-1ß and IL-18, as well as the relative abundance of harmful bacteria (including Catabacter, obinsoniella and Desulfovibrio) in the intestine were significantly increased (P<0.01). In comparison with the model group, the escape latency, serum levels of IL-1ß and IL-18 in the three treatment groups, and the relative abundance of harmful bacteria (such as the Catabacter, Robinsoniella and Desulfovibrio) in the EA-basic acupoints+ST36 group were down-regulated obviously(P<0.05,P<0.01), and the relative abundance of Clostridiales-unclassified in both EA-basic acupoints+probiotics and EA-basic acupoints+ST36 groups was significantly up-regulated (P<0.05). The effects of EA-basic acupoints+ST36 and EA-ba-sic acupoints+probiotics were significantly superior to that of EA-basic acupoints in down-regulating IL-18 content (P<0.05). H.E. staining showed atrophy of the whole mucosal layer, loss of goblet cells, destruction of glands, infiltration of a large number of inflammatory cells, and transmission microscope displayed fuzziness of the nucleus membrane boundary, cystic dilation of the rough endoplasmic reticulum with unclear structure swelling of the mitochondria, and disordered arrangement or dissolution of the inner cristae in the model group, which was relatively milder in the EA-basic acupoints+ST36 and EA-basic acupoints+probiotics groups. CONCLUSION: EA of GV20+GV14+BL23+ ST36 can improve the cognitive dysfunction of VD model rats, which may be related to its function in regulating the imbalance of intestinal microbiota, thereby inhibiting the peripheral inflammatory factor.

Use of fish oil supplements is differently related to incidence of all-cause and vascular dementia among people with the distinct APOE ε4 dosage.

BACKGROUNDS &AIMS: Previous studies have shown that marine omega-3 PUFAs (fish oil) supplements was associated with improved cognitive function, whereas the association between use of fish oil supplements and risk of incident dementia was still unclear. We aimed to prospectively assess the relations between use of fish oil supplements and risks of all-cause and disease-specific dementia according to the apolipoprotein E (APOE) ε4 dosage. METHODS: A total of 445,961 participants from UK biobank, who were free of dementia at baseline and completed data on supplement use and genetic information were analyzed in this study. Cox proportional hazards models were used to calculate the hazard ratios (HRs) comparing incident dementia rates in participants who did and did not use fish oil. RESULTS: During a median of 12.2 years of follow-up, a total of 5795 incident cases of dementia were documented, including 1266 cases of vascular dementia and 2382 cases of AD. After adjustment for covariates, use of fish oil supplements was significantly associated with lower risks of all-cause dementia (Hazard ratios, HR, 95% CI, 0.90, 0.85-0.96) and vascular dementia (HR, 0.85; 95% CI, 0.75-0.97), but not AD (HR, 0.99; 95% CI, 0.91-1.09). For all-cause dementia and vascular dementia, we found that the protective associations appeared to be attenuated by the increasing APOE ε4 dosage (P-interaction = 0.002 and 0.002, respectively). Notably, the use of fish oil supplements was significantly associated with an 86.0% higher risk of vascular dementia in participants with two APOE-ε4 alleles (HR, 1.86, 95%CI, 1.23-2.80). CONCLUSIONS: Our results indicate that use of fish oil supplements is differently associated with risks of all-cause dementia and vascular dementia according to the APOE ε4 dosage.

[Acupuncture improves cognitive function of vascular dementia rats by regulating PI3K/Akt/mTOR pathway].

OBJECTIVE: To explore the mechanism of acupuncture in improving cognitive ability by regulating hippocampal phosphatidylinositol-3 kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway in vascular dementia (VD) rats. METHODS: A total of 80 male SD rats were randomized into sham operation, model, non-acupoint and acupoint groups (n=18 per group). The VD model was established by ligation of the bilateral common carotid arteries. For rats of the acupoint group, "Baihui" (GV20) and bilateral "Zusanli "(ST36) were needled and stimulated by twirling the needles with reinforcing method, and for rats of the non-acupoint group, the bilateral subcostal spots (about 10 mm superior to the iliac cresta) were needled and stimulated by twirling the needles with uniform reinforcing and reducing method. The treatment was conducted once daily, 6 times a week for two weeks, beginning 3 days after successful modeling. Rats of the sham operation group and model group received grasps as those in the acupoint groups. Morris water maze test was used to detect the abilities of learning and spatial memory. The contents of reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD) and the activities of acetylcholinesterase (AChE) and acetylcholine transferase (ChAT) in the hippocampus tissue were detected by using ELISA, changes of hippocampal mitochondrial membrane potential (MMP) detected using JC-1 fluorescence probe, and the expression levels of hippocampal phosphorylated (p)-PI3K, p-Akt and mTOR proteins measured using Western blot. RESULTS: Compared with the sham operation group, the escape latency, contents of ROS and MDA, and AChE activity were significantly increased (P<0.05), and the spatial memory ability, SOD activity, ChAT activity, MMP, p-PI3K, p-Akt and mTOR expression levels were significantly decreased in the model group (P<0.05). Compared with the model group, carotid artery ligature-induced increase of the escape latency, contents of ROS and MDA, and AChE activity, and decrease of the spatial memory ability, SOD activity, ChAT activity, MMP, p-PI3K, p-Akt and mTOR expression levels were significantly reversed in the acupuncture group (P< 0.05), but not in the non-acupoint group (P>0.05). The therapeutic effects of acupoint needling were obviously superior to those of non-acupoint needling in decreasing the escape latency, contents of ROS and MDA, and AChE activity (P<0.05), and in increasing the spatial memory ability, SOD activity, ChAT activity, MMP, p-PI3K, p-Akt and mTOR expre-ssion levels (P<0.05). CONCLUSION: Acupuncture can improve cognitive function of VD rats, which may be related with its functions in easing oxidative stress and MMP reduction by activating PI3K/Akt/mTOR signaling pathway in the hippocampus.

N6-methyladenosine (m6A) modification and its clinical relevance in cognitive dysfunctions.

BACKGROUND: N6 adenosine methylation (m6A) is the most abundant internal RNA modification in eukaryotic cells. Dysregulation of m6A has been associated with the perturbations of cell proliferation and cell death in different diseases. However, the roles of m6A in the neurodegenerative process and cognitive dysfunction are unclear. METHODS: We systematically investigated the molecular alterations of m6A regulators and their clinical relevance with cognitive dysfunctions using published datasets of Alzheimer's Disease (AD), vascular dementia, and mild cognitive impairment (MCI). FINDINGS: The expressions of m6A regulators vary in different tissues and closely correlate with neurodegenerative pathways. We identified co-expressive m6A regulators SNRPG and SNRPD2 as potential biomarkers to predict transformation from MCI to AD. Moreover, we explored correlations between Apolipoprotein E4 and m6A methylations. INTERPRETATION: Collectively, these findings suggest that m6A methylations as potential biomarkers and therapeutic targets for cognitive dysfunction. FUNDING: This work was supported by the National Natural Science Foundation of China (81871040) and the Shanghai Health System Talent Training Program (2018BR29).

Shared and oppositely regulated transcriptomic signatures in Huntington's disease and brain ischemia confirm known and unveil novel potential neuroprotective genes.

Huntington's disease and subcortical vascular dementia display similar dementing features, shaped by different degrees of striatal atrophy, deep white matter degeneration and tau pathology. To investigate the hypothesis that Huntington's disease transcriptomic hallmarks may provide a window into potential protective genes upregulated during brain acute and subacute ischemia, we compared RNA sequencing signatures in the most affected brain areas of 2 widely used experimental mouse models: Huntington's disease, (R6/2, striatum and cortex and Q175, hippocampus) and brain ischemia-subcortical vascular dementia (BCCAS, striatum, cortex and hippocampus). We identified a cluster of 55 shared genes significantly differentially regulated in both models and we screened these in 2 different mouse models of Alzheimer's disease, and 96 early-onset familial and apparently sporadic small vessel ischemic disease patients. Our data support the prevalent role of transcriptional regulation upon genetic coding variability of known neuroprotective genes (Egr2, Fos, Ptgs2, Itga5, Cdkn1a, Gsn, Npas4, Btg2, Cebpb) and provide a list of potential additional ones likely implicated in different dementing disorders and worth further investigation.

NOTCH3 variants are more common than expected in the general population and associated with stroke and vascular dementia: an analysis of 200 000 participants.

BACKGROUND: Cysteine-altering NOTCH3 variants identical to those causing the rare monogenic form of stroke, CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy), have been reported more common than expected in the general population, but their clinical significance and contribution to stroke and dementia risk in the community remain unclear. METHODS: Cysteine-altering NOTCH3 variants were identified in UK Biobank whole-exome sequencing data (N=200 632). Frequency of stroke, vascular dementia and other clinical features of CADASIL, and MRI white matter hyperintensity volume were compared between variant carriers and non-carriers. MRIs from those with variants were visually rated, each matched with three controls. RESULTS: Of 200 632 participants with exome sequencing data available, 443 (~1 in 450) carried 67 different cysteine-altering NOTCH3 variants. After adjustment for various covariates, NOTCH3 variant carriers had increased risk of stroke (OR: 2.33, p=0.0004) and vascular dementia (OR: 5.00, p=0.007), and increased white matter hyperintensity volume (standardised difference: 0.52, p<0.001) and white matter ultrastructural damage on diffusion MRI (standardised difference: 0.72, p<0.001). On visual analysis of MRIs from 47 carriers and 148 matched controls, variants were associated with presence of lacunes (OR: 5.97, p<0.001) and cerebral microbleeds (OR: 4.38, p<0.001). White matter hyperintensity prevalence was most increased in the anterior temporal lobes (OR: 7.65, p<0.001) and external capsule (OR: 13.32, p<0.001). CONCLUSIONS: Cysteine-changing NOTCH3 variants are more common in the general population than expected from CADASIL prevalence and are risk factors for apparently 'sporadic' stroke and vascular dementia. They are associated with MRI changes of small vessel disease, in a distribution similar to that seen in CADASIL.

Differentially expressed genes accompanying neurobehavioral deficits in a modified rat model of vascular dementia.

Vascular dementia refers to the progressive loss of memory and other cognitive functions. The heterogeneity of cerebrovascular disease renders it challenging to elucidate the neuropathological substrates and mechanisms underlying vascular dementia. In this study, we performed neurobehavioral tests, RNA sequencing (RNA-seq), and quantitative real-time polymerase chain reaction (qRT-PCR) tests to evaluate a rat model of modified two-vessel occlusion (2-VO) and identify the differentially expressed genes in the hippocampus of 2-VO versus sham rats by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) annotations. Compared with the sham group, the 2-VO group revealed significantly reduced spontaneous motor behaviors, a lack of exploration for new objects, and varying degrees of spatial memory impairment. Although the genetic background of vascular dementia is well established for monogenic disorders, the relationship between key regulatory genes and signaling pathways remains obscure. Using RNA-seq and bioinformatic analyses, we identified 58 upregulated genes and 137 downregulated genes in the hippocampus of 2-VO rats compared to sham rats. Results were confirmed by qRT-PCR. ErbB3, a gene mainly involved in cranial nervous system development, negative regulation of neuronal apoptosis, and signal transduction, was downregulated in the hippocampus of 2-VO rats compared to sham rats. Moreover, ERBB3 plays an important role in neuron-protecting ERBB and PI3K-AKT signaling pathways, both of which were found to be enriched by GO and KEGG functional pathway analyses. Understanding the molecular mechanisms of vascular dementia may help establish potential treatment targets for cognitive deficits.

Promotive role of microRNA­150 in hippocampal neurons apoptosis in vascular dementia model rats.

Cognitive impairment is one of the primary features of vascular dementia (VD). However, the specific mechanism underlying the regulation of cognition function in VD is not completely understood. The present study aimed to explore the effects of microRNA (miR)­150 on VD. To determine the effects of miR­150 on cognitive function and hippocampal neurons in VD model rats, rats were subjected to intracerebroventricular injections of miR­150 antagomiR. The Morris water maze test results demonstrated that spatial learning ability was impaired in VD model rats compared with control rats. Moreover, compared with antagomiR negative control (NC), miR­150 antagomiR alleviated cognitive impairment and enhanced memory ability in VD model rats. The triphenyltetrazolium chloride, Nissl staining and immunohistochemistry results further demonstrated that miR­150 knockdown improved the activity of hippocampal neurons in VD model rats compared with the antagomiR NC group. To validate the role of miR­150 in neurons in vitro, the PC12 cell line was used. The flow cytometry and Hoechst 33342/PI double staining results indicated that miR­150 overexpression significantly increased cell apoptosis compared with the mimic NC group. Moreover, the dual­luciferase reporter gene assay results indicated that miR­150 targeted HOXA1 and negatively regulated HOXA1 expression. Therefore, the present study indicated that miR­150 knockdown ameliorated VD symptoms by upregulating HOXA1 expression in vivo and in vitro.

Dynamic Changes of Beclin-1 in the Hippocampus of Male Mice with Vascular Dementia at Different Time Points.

This study tried to investigate the dynamic changes of Beclin-1 in the hippocampus of male mice with vascular dementia (VD) at different time points. The mouse model of VD was established by the four-vessel blocking method. Then, the VD mice were randomly divided into five groups (n = 12) according to the disease duration: the 0.1-day model group, 0.5-day model group, 1-day model group, 3-day model group, 5-day model group and 14-day model group. In addition, all surgical procedures were the same in the sham group as those in the model groups, except the mice in the sham group were not subjected to clipping. The expression of Beclin-1, LC3B, p62, Bcl-2, Bax, BACE1, GFAP, MBP and ET-1 mRNA were determined by RT-PCR; the expression of Beclin-1 was detected by Western blot and immunofluorescence; the pathological characteristics of the hippocampus were observed by haematoxylin-eosin (HE) staining; and the correlation of Beclin-1 with other VD-related proteins was analysed by Pearson's correlation. Compared with that in the sham group, the expression of Beclin-1, LC3B, Bax, BACE1, GFAP, MBP and ET-1 mRNA was increased in the VD mice at different time points (0.1 day, 0.5 day, 1 day, 3 days, 5 days and 14 days) (P < 0.05) and then remained relatively stable in the 0.5-day VD mice, whereas the p62 and Bcl-2 mRNA levels decreased (P < 0.05). Beclin-1 protein expression was significantly increased in the VD mice at different time points (P < 0.05). The hippocampus showed a certain degree of neuronal damage in the VD mice at different time points (P < 0.05). Additionally, certain correlations among LC3B, p62, Bcl-2, Bax, BACE1, GFAP, MBP, ET-1 and Beclin-1 were observed in this study. In conclusion, the results described above demonstrated that neuronal damage and dynamic stability of Beclin-1 expression were established in the VD male mice after 0.5 day by the four-vessel blocking method.

Wuzang Wenyang Huayu decoction regulates differentially expressed transcripts in the rats' hippocampus after cerebral hypoperfusion.

The modified Wenyang Huayu decoction has been widely used to treat vascular dementia in China for thousands of years. We have previously proved that a modified version, Wuzang Wenyang Huayu decoction has the potential to be a more effective clinical treatment that can attenuate cerebral ischaemic injury. However, the global transcript profile and signalling conduction pathways regulated by this recipe remains unclear. This study established a two-vessel occlusion rat model by bilateral common carotid artery occlusion. Two groups of rats were intragastrically treated Wuzang Wenyang Huayu 2.5 g/kg vs or Piracetam 0.15 g/kg for 2 weeks. Learning and memory abilities were measured with Morris water maze. Neuronal plasticity was observed by HE staining. Differentially expressed transcripts of rat hippocampus were analysed by transcriptomics with Illumina HiSeq2500 platform. Results showed that Wuzang Wenyang Huayu decoction significantly alleviated learning, memory deficits, coordination dysfunction and prevented hippocampus cellular injury; Results further revealed the increased gene expression in KEGG metabolic pathways (MT-ND2. MT-ND3, MT-ND4, MT-ND4L, MT-ND5 and MT-ATP8) and genes involved in signal transduction, carcinogenesis, immune system, endocrine system, nervous system etc (Results further revealed differential expression of genes involved in various systems, including MT-ND2) Our discovery is likely to provide new insights to molecular mechanisms of Wuzang Wenyang Huayu regarding hippocampal transcripts in a murine vascular dementia model.

Patient-Specific iPSC Model of a Genetic Vascular Dementia Syndrome Reveals Failure of Mural Cells to Stabilize Capillary Structures.

CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy) is the most common form of genetic stroke and vascular dementia syndrome resulting from mutations in NOTCH3. To elucidate molecular mechanisms of the condition and identify drug targets, we established a patient-specific induced pluripotent stem cell (iPSC) model and demonstrated for the first time a failure of the patient iPSC-derived vascular mural cells (iPSC-MCs) in engaging and stabilizing endothelial capillary structures. The patient iPSC-MCs had reduced platelet-derived growth factor receptor ß, decreased secretion of the angiogenic factor vascular endothelial growth factor (VEGF), were highly susceptible to apoptotic insults, and could induce apoptosis of adjacent endothelial cells. Supplementation of VEGF significantly rescued the capillary destabilization. Small interfering RNA knockdown of NOTCH3 in iPSC-MCs revealed a gain-of-function mechanism for the mutant NOTCH3. These disease mechanisms likely delay brain repair after stroke in CADASIL, contributing to the brain hypoperfusion and dementia in this condition, and will help to identify potential drug targets.

Effects of IL-1ß on hippocampus cell apoptosis and learning ability of vascular dementia rats.

OBJECTIVE: Vascular dementia (VD) is a type of memory, cognition, and behavior disorder caused by ischemic stroke or hemorrhagic stroke. It is a common pathogenesis of dementia that is only second to Alzheimer's disease. Inflammation plays a key role in VD. Interleukin-1ß (IL-1ß) is a kind of pro-inflammatory cytokine, while its mechanism in VD occurrence and development is still unclear. MATERIALS AND METHODS: The healthy male rats were randomly divided into three groups, including sham group, VD model group (established by bilateral common carotid artery ligation), and IL-1ß group (treated by IL-1ß monoclonal antibody intracerebroventricular injection on based on model group). Rat learning ability was evaluated by Morris water maze assay. IL-1ß expression in brain tissue and peripheral blood was examined by using Real Time-PCR and enzyme-linked immunosorbent assay (ELISA), respectively. Hippocampus apoptosis was detected by caspase 3 activity detection kit. B-cell lymphoma-2 (Bcl-2) and p38 mitogen-activated protein kinase (MAPK) protein levels were assessed by Western blot assay. RESULTS: IL-1ß expression was increased, caspase 3 activity was enhanced, Bcl-2 level was declined, and p-P38 phosphorylation was elevated in brain tissue and peripheral blood from VD model group compared to sham group (p<0.05). IL-1ß monoclonal antibody significantly reduced IL-1ß expression, improved learning ability, attenuated caspase 3 activity, increased Bcl-2 level, and declined p-P38 expression in VD rats compared to model group (p<0.05). CONCLUSIONS: IL-1ß can delay VD occurrence and development through the P38-MAPK signaling pathway to regulate cell apoptosis and improve learning ability.

Effects of CREB1 gene silencing on cognitive dysfunction by mediating PKA-CREB signaling pathway in mice with vascular dementia.

BACKGROUND: As a form of dementia primarily affecting the elderly, vascular dementia (VD) is characterized by changes in the supply of blood to the brain, resulting in cognitive impairment. The aim of the present study was to explore the effects involved with cyclic adenosine monophosphate (cAMP) response element-binding (CREB)1 gene silencing on cognitive dysfunction through meditation of the protein kinase A (PKA)-CREB signaling pathway in mice with VD. METHODS: Both the Morris water maze test and the step down test were applied to assess the cognitive function of the mice with VD. Immunohistochemical and TUNEL staining techniques were employed to evaluate the positive expression rates of the protein CREB1 and Cleaved Caspase-3, as well as neuronal apoptosis among hippocampal tissues in a respective manner. Flow cytometry was applied to determine the proliferation index and apoptosis rate of the hippocampal cells among each group. Reverse transcription quantitative polymerase chain reaction and Western blot analysis methods were applied to detect the expressions of cAMP, PKA and CREB in hippocampal cells. RESULTS: Compared with the normal group, all the other groups exhibited impaired cognitive function, reduced cell numbers in the CAI area, positive expressions of CREB1 as well as positive optical density (OD) values. Furthermore, increased Cleaved Caspase-3 positive expression, OD value, proliferation index, apoptosis rate of hippocampal cells and neurons, were observed in the other groups when compared with the normal group, as well as lower expressions of cAMP, PKA and CREB1 and p-CREB1 (the shCREB1-1, H89 and shCREB1-1 + H89 groups < the VD group). CONCLUSION: The key findings of the present study demonstrated that CREB1 gene silencing results in aggravated VD that occurs as a result of inhibiting the PKA-CREB signaling pathway, thus exasperating cognitive dysfunction.