Rat Model Of Vascular Dementia Research Articles

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 utilizied in neurological disorders, but conventional hydrogen delivery has the disadvantage of inefficiency. Therefore, we used magnesium silicide nanosheets (MSNs) to release hydrogen in vivo in larger quantities and for longer periods of time to explore the appropriate dosage and regimen. In this study, we observed that hydrogen improved learning and working memory in VaD rats in the Morris water maze and Y-maze, which elicited improved cognitive function. Nissl staining of neurons showed that hydrogen treatment significantly improved edema in neuronal cells. The expression and activation of reactive oxygen species (ROS), Thioredoxin-interacting protein (TXNIP), NOD-like receptor protein 3 (NLRP3), caspase-1 and IL-1β in the hippocampus were measured via ELISA, Western blotting, real-time qPCR, and immunofluorescence. The results showed that oxidative stress indicators and inflammasome-related factors were significantly decreased after 7dMSN treatment. Therefore, we concluded that hydrogen can ameliorate neurological damage and cognitive dysfunction in VaD rats by inhibiting ROS/NLRP3/IL-1β-related oxidative stress and inflammation. This article is protected by copyright. All rights reserved.

The low and high doses administration of lutein improves memory and synaptic plasticity impairment through different mechanisms in a rat model of vascular dementia.

Vascular dementia (VD) is a common type of dementia. This study aimed to evaluate the effects of low and high doses of lutein administration in bilateral-carotid vessel occlusion (2VO) rats. The rats were divided into the following groups: the control, sham-, vehicle (2VO+V) groups, and two groups after 2VO were treated with lutein 0.5 (2VO+LUT-o.5) and 5mg/kg (2VO+LUT-5). The passive-avoidance and Morris water maze were performed to examine fear and spatial memory. The field-potential recording was used to investigate the properties of basal synaptic transmission (BST), paired-pulse ratio (PPR), as an index for measurement of neurotransmitter release, and long-term potentiation (LTP). The hippocampus was removed to evaluate hippocampal cells, volume, and MDA level. Treatment with low and high doses improves spatial memory and LTP impairment in VD rats, but only the high dose restores the fear memory, hippocampal cell loss, and volume and MDA level. Interestingly, low-dose, but not high-dose, increased PPR. However, BST recovered only in the high-dose treated group. Treatment with a low dose might affect neurotransmitter release probability, but a high dose affects postsynaptic processes. It seems likely that low and high doses improve memory and LTP through different mechanisms.

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.

Inhibition of Glial Activation and Subsequent Reduction in White Matter Damage through Supplementation with a Combined Extract of Wheat Bran, Citrus Peel, and Jujube in a Rat Model of Vascular Dementia.

Vascular dementia (VaD) is the second most common type of dementia after Alzheimer's disease. In our previous studies, we showed that wheat bran extract (WBE) reduced white matter damage in a rat VaD model and improved memory in a human clinical trial. However, starch gelatinization made the large-scale preparation of WBE difficult. To simplify the manufacturing process and increase efficacy, we attempted to find a decoction containing an optimum ratio of wheat bran, sliced citrus peel, and sliced jujube (WCJ). To find an optimal ratio, the cell survival of C6 (rat glioma) cultured under hypoxic conditions (1% O2) was measured, and apoptosis was assessed. To confirm the efficacies of the optimized WCJ for VaD, pupillary light reflex, white matter damage, and the activation of astrocytes and microglia were assessed in a rat model of bilateral common carotid artery occlusion (BCCAO) causing chronic hypoperfusion. Using a combination of both searching the literature and cell survival experiments, we chose 6:2:1 as the optimal ratio of wheat bran to sliced citrus peel to sliced jujube to prepare WCJ. We showed that phytic acid contained only in wheat bran can be used as an indicator component for the quality control of WCJ. We observed in vitro that the WCJ treatment improved cell survival by reducing apoptosis through an increase in the Bcl-2/Bax ratio. In the BCCAO experiments, the WCJ-supplemented diet prevented astrocytic and microglial activation, mitigated myelin damage in the corpus callosum and optic tract, and, consequently, improved pupillary light reflex at dosages over 100 mg/kg/day. The results suggest that the consumption of WCJ can prevent VaD by reducing white matter damage, and WCJ can be developed as a safe, herbal medicine to prevent VaD.

7, 8-dihydroxyflavone Ameliorates Cholinergic Dysfunction, Inflammation, Oxidative Stress, and Apoptosis in a Rat Model of Vascular Dementia.

Vascular dementia (VD) is a degenerative cerebrovascular disorder associated with progressive cognitive decline. Previous reports have shown that 7,8-dihydroxyflavone (7,8-DHF), a well-known TrkB agonist, effectively ameliorates cognitive deficits in several disease models. Therefore, this study investigated the protective effects of 7,8-DHF against 2-VO-induced VD.VD was established in rats using the permanent bilateral carotid arteries occlusion (two-vessel occlusion, 2-VO) model. 7,8-DHF (5, 10, and 20mg/kg) and Donepezil (10mg/kg) were administered for 4 weeks. Memory function was assessed by the novel objective recognition task (NOR) and Morris water maze (MWM) tests. Inflammatory (TNF-α, IL-1β, and NF-kβ), oxidative stress, and apoptotic (BAX, BCL-2, caspase-3) markers, along with the activity of choline acetylcholinesterase (AChE) was assessed. p-AKT, p-CREB, BDNF, and neurotransmitter (NT) (GLU, GABA, and ACh) levels were also analyzed in the hippocampus of 2-VO rats.Our results show that 7,8-DHF effectively improved memory performance and cholinergic dysfunction in 2-VO model rats. Furthermore, 7,8-DHF treatment also increased p-AKT, p-CREB, and BDNF levels, suppressed oxidative, inflammatory, and apoptotic markers, and restored altered NT levels in the hippocampus.These findings imply that 7, 8-DHF may act via multiple mechanisms and as such serve as a promising neuroprotective agent in the context of VD.

Baicalein ameliorates cognitive impairment of vascular dementia rats via suppressing neuroinflammation and regulating intestinal microbiota

Neuroinflammation induced by chronic cerebral hypoperfusion (CCH) plays a crucial role in the pathophysiologic mechanisms of vascular dementia (VD). A growing body of research has found that intestinal microbiota is associated with a variety of central nervous system disorders and that there is a relationship between intestinal microbiota dysbiosis and cognitive dysfunction and inflammatory responses. Baicalein belongs to the class of flavonoids and has a variety of biological functions, including anti-inflammatory, antioxidant and anti-apoptotic. Baicalein has a significant improvement in memory and learning, and can be used as a potential drug for the protection and treatment of central nervous system disorders. Whether baicalein has an ameliorative effect on cognitive impairment in VD, and whether its mechanism is related to the inhibition of inflammatory response and regulation of intestinal microbiota has not been reported. We used bilateral common carotid artery occlusion (BCCAO) to establish a VD rat model. Morris water maze (MWM) test showed that baicalein improved cognitive dysfunction in VD rats. We applied HE staining, immunofluorescence and ELISA to observe that baicalein treatment significantly improved CCH-induced neuronal damage in the CA1 region of the hippocampus, and reduced glial cell activation and release of pro-inflammatory factors. Western blot showed that baicalein inhibited the activation of the TLR4/MyD88/NF-κB signaling pathway in VD rats. We applied 16 S rDNA sequencing to analyze the composition of the intestinal microbiota. The results showed that baicalein modulated the diversity and composition of the intestinal microbiota, and suppressed the relative abundance of inflammation-associated microbiota in VD rats. In conclusion, this study found that baicalein ameliorated cognitive impairment, attenuated hippocampal inflammatory responses, inhibited the TLR4/MyD88/NF-κB signaling pathway, and modulated intestinal microbiota in VD rats.

Integration of metabolomics and network pharmacology technology to explain the effect mechanisms of Danggui Buxue decoction in vascular dementia.

Danggui Buxue decoction (DBD) is a traditional Chinese medicine herbal decoction that has a good therapeutic effect on vascular dementia (VaD). However, its pharmacodynamic substances and underlying mechanisms are ambiguous. The work aimed to decipher the pharmacodynamic substances and molecular mechanisms of DBD against VaD rats based on gas chromatography-mass spectrometry metabonomics, network pharmacology, molecular docking, and experimental verification. The results indicated that DBD significantly improved the learning abilities and cognitive impairment in the VaD rat model. Integration analysis of the metabolomics and network pharmacology approach revealed that DBD might primarily affect arachidonic acid (AA) and inositol phosphate metabolic pathways by regulating the platelet activation signaling pathways. Six core targets (TNF [tumor necrosis factor], IL-6 [interleukin 6], PTGS2 [prostaglandin-endoperoxide synthase 2], MAPK1, MAPK3, and TP53) in the platelet activation signaling pathways also had a good affinity to seven main active components (saponins, organic acids, flavonoids, and phthalides) of DBD through the verification of molecular docking. Enzyme-linked immunosorbent assay results (ELISA) showed that the levels of TNF, IL-6, PTGS2, thromboxane B2, and caspase-3 in the platelet activation signaling pathway can be regulated by DBD. Our results indicated that DBD treated VaD mainly by modulating the platelet activation signaling pathway, and AA and inositol phosphate metabolism.

Fucoidan protects CA1 pyramidal neurons of the hippocampus and preserves the cognitive profile of rats subjected to transient forebrain ischemia

Fucoidan, a polysaccharide derived from brown seaweeds, especially Fucus Vesiculosus has been documented as an effective neuroprotectant. This study investigates the efficacy of fucoidan in mitigating the cognitive deficits in the rat model of vascular dementia induced through the 4-vessel occlusions (4VO) method. Male Wistar rats weighing about 250–300 g were randomly assigned into four groups, sham, lesion (4VO), 4VO + F5mg/kg, and 4VO + F50mg/kg. The rats were assessed for cognitive behaviour performance through novel object task, T-maze and Morris water maze, and finally, the hippocampus from the brain was harvested to quantify the profile of CA1 pyramidal neurons through CFV staining and the expression of inflammatory markers and angiogenic markers were quantified through western blot assessment on day7 and 30 of the study period. The rats were treated with fucoidan at a dose of 50 mg/kg. body weight showed improved spatial learning and memory compared to the lesion group and the cytoarchitecture of CA1 pyramidal cells was observed to be well preserved. The expression of IL1β, IL6, TNFα, NFk-B, CD68 and HIFα were found to be down-regulated, while on the contrary the VEGFR2 and angiopoietin-1 were up regulated in the 4VO + F50mg/kg group when compared with the lesion group. In conclusion, this study ascertains the role of fucoidan in support of the cognitive profile of rats subjected to vascular dementia and in preserving the CA1 pyramidal neurons of the hippocampus by regulating the inflammatory and angiogenic factors.

Gens PSD-95 and GSK-3β expression improved by hair follicular stem cells-conditioned medium enhances synaptic transmission and cognitive abilities in the rat model of vascular dementia.

Vascular dementia (VaD) is a common type of dementia. The aim of this study was to investigate the cellular and molecular mechanism of conditioned medium (CM) in VaD. The rats were divided into four groups of control (n=9), sham-operation (n=10), VaD with vehicle (n=9), and VaD with CM (n=12) that received CM on days 4, 14, and 24 after 2VO. Before sacrificing the rats, cognitive performance was assessed through the open-field (OP), passive-avoidance, and Morris-water maze. The field-potential recording was used to investigate basal synaptic transmission (BST) and long-term potentiation (LTP). Subsequently, the hippocampus was dissected, and real-time PCR was used to quantify the expression levels of β1-catenin, insulin-like growth factor-1 (IGF-1), transforming growth factor-beta (TGF-β), glycogen synthase kinase-3β (GSK-3β), postsynaptic density protein 95 (PSD-95), and NR2B genes. The results indicated impaired performance in behavioral tests in 2VO rats, coupled with reductions in BST and LTP induction. The expression levels of β1-catenin, IGF-1, PSD-95, and TGF-β genes decreased, whereas NR2B and GSK-3β expression increased. Treatment with CM restores the expression of PSD-95 and GSK-3β as well as fear-memory, spatial learning, and grooming number without a positive effect on memory retrieval, time spent on the periphery and center of OP. The BST recovered upon administration of CM but, the LTP induction was still impaired. The recovery of BST in VaD rats appears to be the most important outcome of this study which is caused by the improvement of gene expression and leads to the restoration of fear memory.

Botanical Mixture Containing Nitric Oxide Metabolite Enhances Neural Plasticity to Improve Cognitive Impairment in a Vascular Dementia Rat Model.

Vascular dementia (VD), caused by impaired cerebral blood flow, is the most common form of dementia after Alzheimer's disease (AD) in the elderly and is characterized by severe neuronal damage and cognitive decline. Nitric oxide (NO) is an important determinant of vascular homeostasis, and its deficiency is associated with the progression of VD. In this study, we investigated the role of nitrite ion, a NO metabolite in a botanical mixture (BM) of fermented garlic, fermented Scutellaria baicalensis, and Rhodiola rosea on neuron loss and cognitive impairment using a VD rat model. The BM containing the NO metabolite alleviated cognitive deficits and enhanced neural plasticity, as reflected by an increase in long-term potentiation. The BM also alleviated neuron apoptosis, decreased GFAP expression, and oxidative stress, and increased parvalbumin and brain-derived neurotrophic factor (BDNF) levels. These results indicate that BM exerts neuroprotective effects and alleviates cognitive dysfunction while enhancing neuroplasticity, and thus has therapeutic potential against VD.

MiR-181a regulates mitophagy and improves cognitive function in vascular dementia via targeting PINK1/Parkin pathway

This study investigates the mechanism of miR-181a in cognitive function and mitophagy in vascular dementia. A rat model of vascular dementia was established by common carotid artery ligation and then divided into model group (n = 10), mimics group (n = 10), inhibitors group (n = 10), NC group (n = 10), and the remaining 10 rats were in sham operation group. The rats in mimics group were intravenously injected with miR-181a mimics and rats in inhibitors group were injected with miR-181a inhibitors. Model group and mimics group rats had a longer time on the 3rd to 4th day than sham operation group, and inhibitors group had a shorter time than model group and mimics group (all P <0.05). Time in quadrant of the cylindrical platform in model group and mimics group was shortened while it was prolonged in inhibitors group (P < 0.05). miR-181a mRNA level in model group, inhibitors group and NC group was lower. On the contrary, PINK1 and Parkin level was higher. miR-181a mRNA level was higher in mimics group with lower levels of PINK1 and Parkin (P <0.05). miR-181a level in mimics group was significantly increased and PINK1 and Parkin mRNA was decreased. miR-181a mRNA level in inhibitors group decreased significantly, while PINK1 and Parkin mRNA was increased (P <0.05). Parkin expression in mimics group and NC group was reduced. Up-regulation of miR-181 (mimics group) can target and inhibit PINK1/Parkin mRNA, thereby inhibiting mitophagy. miR-181a downregulation in mitochondria can promote PINK1/Parkin expression, thereby activating mitophagy in rats with vascular dementia, alleviating mitochondrial dysfunction, and improving the cognitive ability of rats.

Abnormal Spontaneous Discharges of Primary Sensory Neurons and Pain Behavior in a Rat Model of Vascular Dementia.

Patients with vascular dementia experience more pain than healthy elders, potentially due to the presence of central neuropathic pain. However, the mechanisms underlying neuropathic pain in vascular dementia remain poorly understood, and there is currently a lack of effective treatment available. In this study, a rat model of vascular dementia was induced by permanently occluding the common carotid arteries bilaterally (2-VO). The cognitive impairments in the 2-VO rats were evaluated using the Morris Water Maze test, while HE and LBF staining were employed to assess brain tissue lesions in the hippocampal, cerebral cortex, and white matter regions known to be associated with severe memory and learning deficits. Furthermore, pain-related behavioral tests, including mechanical and thermal stimuli assessments, were conducted, and in vivo electrophysiological recordings of primary sensory neurons were performed. Compared to sham-operated and pre-operative rats, rats with vascular dementia exhibited mechanical allodynia and thermal hyperalgesia 30 days after surgery. Furthermore, in vivo electrophysiology revealed a significant increase in the occurrence of spontaneous activity of Aβ- and C-fiber sensory neurons in the rat model of vascular dementia. These results indicate that neuropathic pain behaviors developed in the rat model of vascular dementia, and abnormal spontaneous discharges of primary sensory neurons may play a crucial role in the development of pain after vascular dementia.

Integrated transcriptome and metabolome analysis to investigate the mechanism of intranasal insulin treatment in a rat model of vascular dementia.

Introduction: Insulin has an effect on neurodegenerative diseases. However, the role and mechanism of insulin in vascular dementia (VD) and its underlying mechanism are unknown. In this study, we aimed to investigate the effects and mechanism of insulin on VD. Methods: Experimental rats were randomly assigned to control (CK), Sham, VD, and insulin (INS) + VD groups. Insulin was administered by intranasal spray. Cognitive function was evaluated using the Morris's water maze. Nissl's staining and immunohistochemical staining were used to assess morphological alterations. Apoptosis was evaluated using TUNEL-staining. Transcriptome and metabolome analyses were performed to identify differentially expressed genes (DEGs) and differentially expressed metabolites (DEMs), respectively. Results: Insulin significantly improved cognitive and memory functions in VD model rats (p < 0.05). Compared with the VD group, the insulin + VD group exhibited significantly reduced the number of Nissl's bodies numbers, apoptosis level, GFAP-positive cell numbers, apoptosis rates, and p-tau and tau levels in the hippocampal CA1 region (p < 0.05). Transcriptomic analysis found 1,257 and 938 DEGs in the VD vs. CK and insulin + VD vs. VD comparisons, respectively. The DEGs were mainly enriched in calcium signaling, cAMP signaling, axon guidance, and glutamatergic synapse signaling pathways. In addition, metabolomic analysis identified 1 and 14 DEMs between groups in negative and positive modes, respectively. KEGG pathway analysis indicated that DEGs and DEMs were mostly enriched in metabolic pathway. Conclusion: Insulin could effectively improve cognitive function in VD model rats by downregulating tau and p-tau expression, inhibiting astrocyte inflammation and neuron apoptosis, and regulating genes involved in calcium signaling, cAMP signaling, axon guidance, and glutamatergic synapse pathways, as well as metabolites involved in metabolic pathway.

Wuzang Wenyang Huayu Tang promoting learning-memory ability in vascular dementia rats via brain-gut-microbiome axis

IntroductionLots of research has revealed that vascular dementia (VD), which is closely related to the metabolic disorders of intestinal microbiota, can be treated through traditional Chinese drug by regulating the brain-gut-microbiome axis. However, the specific interaction between VD and intestinal microflora, as well as the mechanism of Wuzang Wenyang Huayu Tang (WWHT) in treating VD by regulating the brain-gut-microbiome axi remains unknown on the whole and needs to be further studied. ObjectivesTo explore the effect of WWHT on the learning and memory ability of rats with VD based on brain-gut-microbiome axis. MethodsIn this study, taking the specific pathogen-free (SPF) SD rats as the subjects, a vascular dementia rat model was created by using the two-vessel occlusion model (2-VO). The subjects were divided into six groups, namely control group, sham group, VD model group, the piracetam group, the WWHT group, and the WWHT combined with piracetam (WCP) group. After 22 days of the gavage administration method, the Morris water maze experiment was adopted to determine the learning and memory abilities of each group through the water maze, observe the effects of hematoxylin and eosin (HE) staining and transmission electron microscopy in the hippocampal area of each group, and analyze the relevant proteins in the whole brain by Western Blot (WB). In addition, the feces of each group were collected and analyzed by fecal metabolomics combined with 16S rRNA gene sequencing to explore the interaction between VD and intestinal microbiota. ResultsThrough Morris water maze experiment, it was found that the learning and memory ability of VD rats in WWHT, piracetam and WCP groups was improved. The morphology of hippocampal neuron cells were improved in the WWHT group and the number of hippocampal neuron cells were increased in the VD rats by HE. By observing the ultrastructure of hippocampal cells, it can be found that the VD model group showed cell membrane edema and large organelle lysis. The ultrastructure of the hippocampus of all the administered groups was improved. In terms of the effect on the expression levels of related proteins in the whole brain of rats, compared with the VD model group, the expression levels of Caspase-3 protein decreased in all groups after drug administration. The protein expression levels of APG5L/ATG5, Beclin-1 and LC3A/B were upregulated, indicating that the drug administration group could regulate cellular autophagy in the whole brain to further protect brain tissue. Fecal metabolite profiles revealed 27 different metabolites related to VD. These metabolites are mainly involved in related metabolic pathways, such as vitamin B metabolism, purine metabolism, pyrimidine metabolism, and histidine metabolism. Further analysis of the gut microbiota by 16S rRNA gene sequencing data showed that WWHT-treated VD rats were different in gut microbiota composition. DiscussionThrough the effect of brain-gut-microbiome axis, WWHT regulates the metabolism of vitamin B6 and tryptophan in VD rats, which can improve the intestinal microbiota of VD rats and regulate autophagy in the brain to improve cell morphology in the hippocampus, thus increasing the number of hippocampal cells to protect hippocampal neuron cells2510100, and finally improving the learning and memory ability of VD rats.

Effect of Huangdisan grain on improving cognitive impairment in VD rats and its mechanism in immune inflammatory response.

Vascular dementia (VD) is the second most common type of dementia after Alzheimer's disease (AD). Although the incidence rate is very high, there is no definitive treatment for VD. And it has serious impact on the quality of life of VD patients. In recent years, more and more studies about the clinical efficacy and pharmacological effects of traditional Chinese medicine (TCM) in the treatment of VD have been conducted. And Huangdisan grain has been used to treat VD patients with a good curative effect in clinic. This study was designed to investigate the effect of Huangdisan grain on the inflammatory response and cognitive function of VD rats modeled by bilateral common carotid artery occlusion (BCCAO), that aimed to improve the treatment methods for VD. 8-week-old healthy SPF male Wistar rats (280±20g) were randomly divided into the normal group (Gn, n=10), sham operated group (Gs, n=10), and operated group (Go, n=35). The VD rat models in Go group were established by BCCAO. 8weeks after surgery, the operated rats were screened by the hidden platform trail of Morris Water Maze (MWM), and the rats with cognitive dysfunction were further randomly divided into the impaired group (Gi, n=10) and TCM group (Gm, n=10). The VD rats in Gm group were given the intragastric administration of Huangdisan grain decoction once a day for 8weeks, and the other groups were given intragastric administration of normal saline. Then the cognitive ability of rats in each group was detected by the MWM Test. The lymphocyte subsets in peripheral blood and hippocampus of rats were measured by flow cytometry. The levels of cytokines (IL-1β, IL-2, IL-4, IL-10, TNF-α, INF-γ, MIP-2, COX-2, iNOS) in peripheral blood and hippocampus were measured by ELISA (enzyme linked immunosorbent assay). The number of Iba-1+ CD68+ co-positive cells in the CA1 region of hippocampus was measured by immunofluorescence. Compared with the Gn group, the escape latencies of the Gi group were prolonged (P<0.01), the time spent in the former platform quadrant was shortened (P<0.01), and the number of times of crossing over the former platform location was reduced (P<0.05). But compared with the Gi group, the escape latencies of Gm group were shortened (P<0.01), the time spent in the former platform quadrant was prolonged (P<0.05), and the number of times of crossing over the former platform location was increased (P<0.05). The number of Iba-1+ CD68+ co-positive cells in the CA1 region of hippocampus of VD rats in Gi group was increased (P<0.01) compared with the Gn group. And the proportions of T Cells, CD4+ T Cells, CD8+ T Cells in the hippocampus were increased (P<0.01). The level of pro-inflammatory cytokines in the hippocampus was increased significantly, such as IL-1β (P<0.01), IL-2 (P<0.01), TNF-α (P<0.05), IFN-γ (P<0.01), COX-2 (P<0.01), MIP-2 (P<0.01) and iNOS (P<0.05). And the level of IL-10 (P<0.01), a kind of anti-inflammatory cytokine, was decreased. The proportions of T Cells (P<0.05), CD4+ T Cells (P<0.01) and NK Cells (P<0.05) in the peripheral blood of the VD rats in Gi group were decreased, and the level of IL-1β, IL-2, TNF-α, IFN-γ, COX-2, MIP-2 and iNOS was increased significantly (P<0.01) compared with the Gn group. Meanwhile, the level of IL-4 and IL-10 was decreased (P<0.01). Huangdisan grain could reduce the number of Iba-1+ CD68+ co-positive cells in the CA1 region of hippocampus (P<0.01), decrease the proportions of T Cells, CD4+ T Cells, CD8+ T Cells and the level of IL-1β, MIP-2 in hippocampus (P<0.01) of VD rats. Moreover, it could rise the proportion of NK Cells (P<0.01) and the level of IL-4 (P<0.05), IL-10 (P<0.05), and decrease the level of IL-1β (P<0.01), IL-2 (P<0.05), TNF-α (P<0.01), IFN-γ (P<0.01), COX-2 (P<0.01) and MIP-2 (P<0.01) in peripheral blood of VD rats. This study indicated that Huangdisan grain could decrease the activation of microglia/macrophages, regulate the proportions of lymphocyte subsets and the level of cytokines, which could adjust the immunologic abnormalities of VD rats, and ultimately improve cognitive function.

Dl-3-n-Butylphthalide Protects against Memory Deficits in Vascular Dementia Rats by Attenuating Pyroptosis via TLR-4/NF-κB Signaling Pathway

Introduction: Inflammation is closely associated with the pathogenesis of vascular dementia (VD). Dl-3-n-butylphthalide (NBP) is a small molecule compound extracted from the seeds of Chinese celery, which have anti-inflammatory properties in animal models of acute ischemia and patients with stroke. In this experiment, we studied the protective effects of NBP in a rat model of VD induced by permanent bilateral occlusion of the common carotid arteries and investigated the role of the TLR-4/NF-κB inflammatory signaling pathway in the pathology of VD. Methods: The Morris water maze test was used to evaluate cognitive deficits in the VD rats. Western blot, immunohistochemistry, and PCR analyses were used to analyze the molecular basis of the inflammatory response. Results: NBP significantly improved the learning and memory ability of VD rats. With regard to the protective mechanism, the results showed that NBP significantly downregulated the relative expression of Cleaved Cas-1/Cas-1 and Cleaved GSDMD/GSDMD. Moreover, NBP decreased the levels of the TLR-4 and NF-κB (P65) protein and phosphorylation of P65 in the hippocampus of VD rats via the TLR-4/NF-κB signaling pathway. Conclusion: These findings demonstrate that NBP protects against memory deficits in permanent bilateral common carotid artery occlusion-induced VD rats by attenuating pyroptosis via the TLR-4/NF-κB signaling pathway.

Study on inhibitory effect of GC-miR-143 inhibitor nanoparticles on D2 receptor-mediated neurological behavioral damage in lacunar infarction

Blocking the dopamine D2 receptor is a key link in anti-psychiatric disease. Knockdown of miR-143 improved neurological behavioral damage by regulating the D2 receptor signaling pathway. The risk of neurological behavior damage can be increased 20 times by 1–2 lacunar infarction lesions. Based on the fact that miR-143 can target and regulate the D2 receptor signaling pathway, this study focused on analyzing the inhibitory effect of GC-miR-143 inhibitor nanoparticles on neurological behavior damage in lacunar infarction. 60 SD rats were separated into sham operation, model, vehicle, vehicle+inhibitor, inhibitor, or D2 agonist group (n = 10). The vascular dementia (VD) model was made by ligating bilateral common carotid arteries. Morris water maze assessed rats behavioral changes. Quantitative Real-Time Reverse Transcription PCR (QRT-PCR) was applied to detect levels of miRNA-143. Proteins were extracted from the prefrontal cortex, and immunoblotting was performed to measure the downstream of signal proteins of Neuregulin 1 (NRG1) and D2 receptor signaling pathways, p-protein kinase B (AKT) and p-Glycogen Synthase Kinase 3β (GSK3β). On days 1 to 5 of the water maze experiment, the escape latency for the five groups of rats were longer than in sham group; while escape latency for vehicle+inhibitor group and inhibitor group was shorter. Compared to VD model rats, vehicle+inhibitor group and inhibitor group had significantly reduced escape latency. Cross-platform time number for five groups was decreased and it was increased in vehicle+inhibitor group and inhibitor group with decreased number for D2 agonist group w. Compared with D2 agonist group, the vehicle+inhibitor group and inhibitor group showed more cross-platform times. Compared to sham operation group, levels of NRG1, p-AKT/GSK3β in remaining five groups were significantly decreased. Their levels in vector+inhibition group and inhibitor group were dramatically up-regulated, and levels of the above-mentioned proteins in D2 agonist group were significantly decreased. Their levels in vector+inhibitor group and inhibitor group were up-regulated relative to D2 agonist group. The GC-miR-143 inhibitor nanoparticles can up-regulate the expression of NRG1 and antagonize the D2 receptor to weaken the inhibitory effect of D2 receptor-mediated signaling pathways and inhibit neurological behavioral damage in lacunar cerebral infarction.

Acupuncture regulates the Th17/Treg balance and improves cognitive deficits in a rat model of vascular dementia

ObjectiveThe present study was developed to explore the impact of acupuncture on the Th17/Treg balance in the brain and the periphery and associated changes in cognitive deficits in a rat model of vascular dementia (VD). MethodsMale Wistar rats (8 weeks old) were randomly assigned to sham-operated (Gs, n = 10), and operation (n = 30) groups. A VD model was established for all rats in the operation group via the permanent bilateral occlusion of the common carotid artery. Behavioral screening of these rats was conducted via a hidden platform trial at 2 months post-operation. These operation group rats were then further subdivided into impaired (Gi) and acupuncture (Ga) groups (n = 10/group). Acupuncture was performed over a 21-day period for rats in the Ga group. A Morris water maze (MWM) test was used to assess cognitive function for rats in all groups. Flow cytometry and fluorescent staining were used to detect Th17 and Treg cells in samples from these animals based on IL-17/FoxP3 or CD4+FoxP3+/CD4+RORγt+ staining profiles. ResultsRelative to the Gs group, escape latency values for rats in the Gi group were significantly increased. Following treatment, rats in the Ga group exhibited significant reductions in escape latency values as compared to rats in the Gi group (P < 0.05). The relative Treg proportion in the peripheral blood and spleen additionally trended upwards in these Ga rats as compared to those in the Gi group (P > 0.05), whereas the frequency of Th17 cells in the peripheral blood and spleen of Ga group rats trended downward relative to the Gi group (P > 0.05). Significantly fewer CD4+RORγt+ and RORγt+ cells were detected in the Ga group relative to the Gi group, whereas CD4+FoxP3+ and FoxP3+ cell counts were increased (P < 0.01). ConclusionIn summary, VD model rats exhibited dysregulated Th17/Treg homeostasis. Acupuncture treatment was sufficient to reduce the frequency and numbers of Th17 cells in these animals while increasing Treg cell levels, thereby alleviating cognitive deficits with respect to both spatial learning and memory impairment. Consequently, the therapeutic benefits of such acupuncture treatment may be attributable to the regulation of the Th17/Treg balance and associated improvements in cognitive function.

Acupoint catgut embedding improves learning and memory impairment in vascular dementia rats.

Vascular dementia (VD) is a disease that affects brain function through cerebrovascular disease. Due to its complex pathogenesis, there is no effective drug treatment for VD. The present study aimed to evaluate the role of acupoint catgut embedding in the treatment of rats with VD and its possible molecular mechanism. A modified 4 vessel occlusion (4-VO) method was used to establish a VD model rat, and spatial learning and memory ability was assessed using the Morris water maze (MWM) test. The protein expression levels were detected by Western blot. Hematoxylin and eosin (HE) staining was used for histological analysis and enzyme-linked immunosorbent assay (ELISA) was applied for analysis of serum inflammatory factors. We successfully constructed VD model rats with spatial learning and memory impairment, hippocampus injury, and high inflammatory response. Treatment of VD rats with acupoint catgut embedding significantly reduced escape latency and increased the time in the target quadrant and platform crossing times. VD-mediated hippocampal tissue damage and inflammatory reaction [down-regulating interleukin-1β (IL-1β), interleukin-6 (IL-6)] were significantly alleviated by acupoint catgut embedding treatment. In addition, further mechanism exploration found that acupoint catgut embedding treatment could improve the activity of the toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88)/nuclear factor-κB (NF-κB) signaling pathway. In summary, acupoint catgut embedding treatment improved spatial learning and memory loss, alleviated pathological damage of the hippocampus, and inhibited inflammation response in VD rats, which was probably related to the inhibition of the TLR4/MyD88/NF-κB signaling pathway. Acupoint catgut embedding may warrant further study as an adjuvant therapy for the treatment of VD.

Dendrobium Nobile Polysaccharides Attenuates Ferroptosis and Improves Cognitive Function in Vascular Dementia Rats.

To investigate the neuroprotective effect and mechanism of Dendrobium nobile polysaccharide (DNP) on vascular dementia (VD) rats. VD model rats were prepared by permanent ligation of bilateral common carotid arteries. Cognitive function was tested by morris water maze test, mitochondrial morphology and ultrastructure of hippocampal synapses were tested by transmission electron microscopy, GSH, xCT, GPx4, and PSD-95 expressions were tested by western blot and PCR. The number of platform crossing was significantly increased, and the escape latency was significantly shorter in DNP group. The expressions of GSH, xCT and GPx4 in the hippocampus were up-regulated in DNP group. Moreover, the synapses of DNP group were relatively intact and synaptic vesicles increased, the length of synaptic active zone and PSD thickness were significantly increased, and PSD-95 protein expression was significantly up-regulated compared VD group. DNP may take a neuroprotective effect by inhibiting ferroptosis in VD.