Middle Cerebral Artery Occlusion In Rats Research Articles

Electro-scalp acupuncture regulates the expression of CYP27a1/b1, CYP24a and related inflammatory cytokines in ischemic cortex of rats with middle cerebral artery occlusion.

To observe the effect of electro-scalp acupuncture (ESA) on the expression of cytochrome P450a1/b1 (CYP27a1/b1), cytochrome P45024a (CYP24a), signal transducer and activator of transcription (STAT)4, STAT6, tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-4 in ischemic cerebral cortex of rats with acute ischemic stroke, so as to explore its mechanism in alleviating inflammatory reaction of ischemic stroke. Sixty SD rats were randomly divided into sham-operation, model, vitamin D3 and ESA groups, with 15 rats in each group. The middle cerebral artery occlusion rat model was established with thread ligation according to Zea-Longa's method. Rats in the vitamin D3 group were given 1, 25-VitD3 solution (3 ng·100 g-1·d-1) by gavage, once daily for 7 days. Rats in the ESA group were treated at bilateral anterior parietotemporal slash (MS6) with ESA (2 Hz/100 Hz, 1 mA), 30 min a day for 7 days. Before and after interventions, the neurological deficit score and neurobehavioral score were evaluated. TTC staining was used to detect the volume of cerebral infarction in rats. The positive expressions of CYP24a, CYP27a1 and CYP27b1 in the cerebral cortex of ischemic area were detected by immunofluorescence. The mRNA expressions of STAT4 and STAT6 in the cerebral cortex of ischemic area were detected by quantitative real-time PCR. The protein expression levels of TNF-α, IL-1β and IL-4 in the cerebral cortex of ischemic area were detected by Western blot. Compared with the sham-operation group, the neurological deficit score, neurobehavioral score, the percentage of cerebral infarction volume, the positive expression level of CYP24a and mRNA expression level of STAT4, protein expression levels of TNF-α and IL-1β in cerebral cortex were increased (P<0.01), while the positive expression levels of CYP27a1/b1 and STAT6 mRNA, protein expression level of IL-4 were decreased (P<0.01) in the model group. After the treatment and compared with the model group, the neurological deficit score, neurobehavioral score, the percentage of cerebral infarction volume, the positive expression level of CYP24a and mRNA expression level of STAT4, protein expression levels of TNF-α and IL-1β in cerebral cortex were decreased (P<0.01), while the positive expression levels of CYP27a1/b1 and STAT6 mRNA expression level, protein expression level of IL-4 were increased (P<0.01) in the ESA and vitamin D3 groups. ESA can alleviate the inflammatory response in ischemic stroke, which maybe related to its function in regulating the balance between CYP27a1/b1 and CYP24a, converting vitamin D into active vitamin D3, inhibiting vitamin D3 degradation, and regulating Th1/Th2 balance.

MSC Promotes the Secretion of Exosomal lncRNA KLF3-AS1 to Regulate Sphk1 Through YY1-Musashi-1 Axis and Improve Cerebral Ischemia-Reperfusion Injury.

Stroke remains the 3rd leading cause of long-term disability globally. Over the past decade, mesenchymal stem cell (MSC) transplantation has been proven as an effective therapy for ischemic stroke. However, the mechanism of MSC-derived exosomal lncRNAs during cerebral ischemia/reperfusion (I/R) remains ambiguous. The oxygen-glucose deprivation/reoxygenation (OGD/R) and middle cerebral artery occlusion (MCAO) rat model were generated. MSCs were isolated and characterized by flow cytometry and histochemical staining, and MSC exosomes were purified and characterized by transmission electron microscopy, flow cytometry and Western blot. Western blot, RT-qPCR and ELISA assay were employed to examine the expression or secretion of key molecules. CCK-8 and TUNEL assays were used to assess cell viability and apoptosis. RNA immunoprecipitation and RNA pull-down were used to investigate the direct association between krüppel-like factor 3 antisense RNA 1 (KLF3-AS1) and musashi-1(MSI1). Yin Yang 1 (YY1)-mediated transcriptional regulation was assessed by chromatin immunoprecipitation and luciferase assays. The histological changes and immunoreactivity of key molecules in brain tissues were examined by H&E and immunohistochemistry. MSCs were successfully isolated and exhibited directionally differential potentials. MSC exosomal KLF3-AS1 alleviated OGD/R-induced inflammation in SK-N-SH and SH-SY5Y cells via modulating Sphk1. Mechanistical studies showed that MSI1 positively regulated KLF3-AS1 expression through its direct binding to KLF3-AS1. YY1 was identified as a transcription activator of MSI1 in MSCs. Functionally, YY1/MSI1 axis regulated the release of MSC exosomal KLF3-AS1 to modulate sphingosine kinase 1 (Sphk1)/NF-κB pathway, thereby ameliorating OGD/R- or cerebral I/R-induced injury. MSCs promote the release of exosomal KLF3-AS1 to regulate Sphk1 through YY1/MSI axis and improve cerebral I/R injury.

High-frequency rTMS alleviates cognitive impairment and regulates synaptic plasticity in the hippocampus of rats with cerebral ischemia

Poststroke cognitive impairment (PSCI) is a common complication of stroke, but effective treatments are currently lacking. Repetitive transcranial magnetic stimulation (rTMS) is gradually being applied to treat PSCI, but there is limited evidence of its efficacy. To determine rTMS effects on PSCI, we constructed a transient middle cerebral artery occlusion (tMCAO) rat model. Rats were then grouped by random digital table method: the sham group (n = 10), tMCAO group (n = 10) and rTMS group (n = 10). The shuttle box and Morris water maze (MWM) tests were conducted to detect the cognitive functions of the rats. In addition, synaptic density and synaptic ultrastructural parameters, including the active zone length, synaptic cleft width, and postsynaptic density (PSD) thickness, were quantified and analyzed using an electron microscope. What’s more, synaptic associated proteins, including PSD95, SYN, and BDNF were detected by western blot. According to the shuttle box and MWM tests, rTMS improved tMCAO rats’ cognitive functions, including spatial learning and memory and decision-making abilities. Electron microscopy revealed that rTMS significantly increased the synaptic density, synaptic active zone length and PSD thickness and decreased the synaptic cleft width. The western blot results showed that the expression of PSD95, SYN, and BDNF was markedly increased after rTMS stimulation. Based on these results, we propose that 20 Hz rTMS can significantly alleviate cognitive impairment after stroke. The underlying mechanism might be modulating the synaptic plasticity and up-regulating the expression PSD95, SYN, and BDNF in the hippocampus.

Ecdysterone improves oxidative damage induced by acute ischemic stroke via inhibiting ferroptosis in neurons through ACSL4

Ethnopharmacological relevanceAcute ischemic stroke (AIS) is a prominent cause of disability and mortality around the world. Achyranthes bidentata Blume, a regularly prescribed traditional Chinese herb, plays a significant role in traditional Chinese stroke therapy due to its ability to promote blood circulation and remove stasis. Ecdysterone (EDS) is one of the key active components in Achyranthes bidentata Blume, which exhibits antioxidant and anti-cerebral hypoxia properties. However, whether EDS improves AIS and the mechanism of action of AIS is still unclear. Aim of the studyThe objective of this study was to observe whether EDS ameliorates oxidative damage caused by AIS by inhibiting ferroptosis in neurons via ACSL4. Materials and methodsIn vivo, the Middle cerebral artery occlusion (MCAO) rat model was established for research. After treatment with EDS, Neurologic score, TTC, HE and FJC staining were performed, followed by measurements of oxidative stress-related indicators, the content of Fe2+, iron deposition levels and expression of ACSL4, NCOA4 and FTH1 in brain tissue. In vitro, oxygen-glucose deprivation and reperfusion (OGD/R) cell model was established. After treatment with EDS, cell viability, oxidative stress-related indicators, the content of Fe2+ and expression of ACSL4, NCOA4 and FTH1 were detected. In addition, the overexpression of ACSL4 and CETSA technology further elucidated that EDS improves AIS through ACSL4. ResultsThe results showed that the treatment of EDS could improve the oxidative damage of MCAO rats by inhibiting ferroptosis, and then improve AIS. Importantly, EDS inhibited ferroptosis via ACSL4, thereby inhibiting oxidative stress in MCAO rats or OGD/R-induced PC12 cells. ConclusionsThese results provide evidence that EDS ameliorates oxidative damage caused by AIS by inhibiting ferroptosis via ACSL4, and provide new insights into the potential use of EDS as an effective drug development candidate for AIS.

Scutellarin alleviates microglia‐mediated neuroinflammation and apoptosis after ischemic stroke through the PI3K/AKT/GSK3β signaling pathway

AbstractMicroglia are resident immune cells in the central nervous system that are rapidly activated to mediate neuroinflammation and apoptosis, thereby aggravating brain tissue damage after ischemic stroke (IS). Although scutellarin has a specific therapeutic effect on IS, the potential target mechanism of its treatment has not been fully elucidated. In this study, we explored the potential mechanism of scutellarin in treating IS using network pharmacology. Lipopolysaccharide (LPS) was used to induce an in vitro BV‐2 microglial cell model, while middle cerebral artery occlusion (MCAO) was used to induce an in vivo animal model. Our findings indicated that scutellarin promoted the recovery of cerebral blood flow in MCAO rats at 3 days, significantly different from that in the MCAO group. Western blotting and immunofluorescence revealed that scutellarin treatment of BV‐2 microglial cells resulted in a significant reduction in the protein expression levels and incidence of cells immunopositive for p‐NF‐κB, TNF‐α, IL‐1β, Bax, and C‐caspase‐3. In contrast, the expression levels of p‐PI3K, p‐AKT, p‐GSK3β, and Bcl‐2 were further increased, significantly different from those in the LPS group. The PI3K inhibitor LY294002 had similar effects to scutellarin by inhibiting neuroinflammation and apoptosis in activated microglia. The results of the PI3K/AKT/GSK3β signaling pathway and NF‐κB pathway in vivo in MCAO models induced microglia at 3 days were consistent with those obtained from in vitro cells. These findings indicate that scutellarin plays a neuroprotective role by reducing microglial neuroinflammation and apoptosis mediated by the activated PI3K/AKT/GSK3β/NF‐κB signaling pathway.

Voacangine mitigates oxidative stress and neuroinflammation in middle cerebral artery occlusion-induced cerebral ischemia/reperfusion injury by averting the NF-κBp65/MAPK signaling pathways in rats.

Ischemic stroke is a leading cause of human mortality. Cerebral ischemia-reperfusion injury (CI/RI) is a primary cause of stroke. Ischemia-reperfusion (I/R) resulting in oxidative stress and inflammatory events may lead to severe neuronal impairments. Thus, anti-oxidative and anti-inflammatory mediators that can alleviate post-I/R neuronal injuries are required for the treatment of CI/RI. An alkaloid, voacangine (VCG) is a recognized antioxidant, anti-inflammatory, and anticancer agent. Hence, the current study intended to explore the neuroprotective potential and the principal mechanisms of VCG in CI/RI. The experimental rats were divided into four sets: control, I/R-induced, I/R + VCG (2.5 mg/kg), I/R + VCG (5 mg/kg). CI/RI was induced by implanting a thread into the middle cerebral artery occlusion (MCAO) model. Brain damages were assessed on the basis of brain edema, brain infarct volume, neurological deficit score, histopathology, oxidative stress, and neuroinflammation. Results revealed that VCG inhibited the triggering of NLRP3 inflammasome, pro-inflammatory cytokines, lipid peroxidation, but enhanced the antioxidant status in MCAO rats. Furthermore, VCG treatment averted brain damage by I/R, neuroinflammation, and oxidative stress by suppressing NF-κBp65/MAPK pathways. The results of the study provide pertinent insights pertaining to the role of VCG as a potential neuroprotective agent against ischemic stroke.

The Water Extract of Rhubarb Prevents Ischemic Stroke by Regulating Gut Bacteria and Metabolic Pathways.

Rhubarb (RR), Chinese name Dahuang, is commonly used in the treatment of ischemic stroke (IS). However, its potential mechanism is not fully elucidated. This study intended to verify the effect of RR on IS and investigate the possible mechanism of RR in preventing IS. IS in male rats was induced by embolic middle cerebral artery occlusion (MCAO) surgery, and drug administration was applied half an hour before surgery. RR dramatically decreased the neurological deficit scores, the cerebral infarct volume, and the cerebral edema rate, and improved the regional cerebral blood flow (rCBF) and histopathological changes in the brain of MCAO rats. The 16S rRNA analysis showed the harmful microbes such as Fournierella and Bilophila were decreased, and the beneficial microbes such as Enterorhabdus, Defluviitaleaceae, Christensenellaceae, and Lachnospira were significantly increased, after RR pretreatment. 1H-nuclear magnetic resonance (1H-NMR) was used to detect serum metabolomics, and RR treatment significantly changed the levels of metabolites such as isoleucine, valine, N6-acetyllysine, methionine, 3-aminoisobutyric acid, N, N-dimethylglycine, propylene glycol, trimethylamine N-oxide, myo-inositol, choline, betaine, lactate, glucose, and lipid, and the enrichment analysis of differential metabolites showed that RR may participate in the regulation of amino acid metabolism and energy metabolism. RR exerts the role of anti-IS via regulating gut bacteria and metabolic pathways.

Luteolin-7-O-β-d-glucuronide Ameliorates Cerebral Ischemic Injury: Involvement of RIP3/MLKL Signaling Pathway.

Luteolin-7-O-β-d-glucuronide (LGU) is a major active flavonoid glycoside compound that is extracted from Ixeris sonchifolia (Bge.) Hance, and it is a Chinese medicinal herb mainly used for the treatment of coronary heart disease, angina pectoris, cerebral infarction, etc. In the present study, the neuroprotective effect of LGU was investigated in an oxygen glucose deprivation (OGD) model and a middle cerebral artery occlusion (MCAO) rat model. In vitro, LGU was found to effectively improve the OGD-induced decrease in neuronal viability and increase in neuronal death by a 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and a lactate dehydrogenase (LDH) leakage rate assay, respectively. LGU was also found to inhibit OGD-induced intracellular Ca2+ overload, adenosine triphosphate (ATP) depletion, and mitochondrial membrane potential (MMP) decrease. By Western blotting analysis, LGU significantly inhibited the OGD-induced increase in expressions of receptor-interacting serine/threonine-protein kinase 3 (RIP3) and mixed lineage kinase domain-like protein (MLKL). Moreover, molecular docking analysis showed that LGU might bind to RIP3 more stably and firmly than the RIP3 inhibitor GSK872. Immunofluorescence combined with confocal laser analyses disclosed that LGU inhibited the aggregation of MLKL to the nucleus. Our results suggest that LGU ameliorates OGD-induced rat primary cortical neuronal injury via the regulation of the RIP3/MLKL signaling pathway in vitro. In vivo, LGU was proven, for the first time, to protect the cerebral ischemia in a rat middle cerebral artery occlusion (MCAO) model, as shown by improved neurological deficit scores, infarction volume rate, and brain water content rate. The present study provides new insights into the therapeutic potential of LGU in cerebral ischemia.

Investigation of the underlying mechanism of Buyang Huanwu decoction in ischemic stroke by integrating systems pharmacology-proteomics and in vivo experiments

Buyang Huanwu Decoction (BHD) has been effective in treating ischemic stroke (IS). However, its mechanism of action remains unclear. The study intended to explore the potential mechanism of BHD against IS using systems pharmacology, proteomics, and animal experiments. The active components of BHD were identified from UPLC-Q-TOF-MS and literature mining. Systems pharmacology and proteomics were employed to investigate the underlying mechanism of BHD against IS. The AutoDock tool was used for molecular docking. A middle cerebral artery occlusion (MCAO) model rat was utilized to explore the therapeutic benefits of BHD. The rats were divided into sham, model, BHD (5, 10, 20 g/kg, ig) groups. The neurological scores, pathological section characteristics, brain infarct volumes, inflammatory cytokines, and signaling pathways were investigated in vivo experiments. The results of systems pharmacology showed that 13 active compounds and 112 common targets were screened in BHD. The docking results suggested that the active compounds in BHD had a high affinity for the key targets. In vivo experiments demonstrated that BHD exhibited neuroprotective benefits by lowering the neurological score, the volume of the cerebral infarct, the release of inflammatory cytokines, and reducing neuroinflammatory damage in MCAO rats. Furthermore, BHD decreased TNF-α and CD38 levels while increasing ATP2B2, PDE1A, CaMK4, p-PI3K, and p-AKT. Combined with systems pharmacology and proteomic studies, we confirmed that PI3K-Akt and calcium signaling pathways are the key mechanisms for BHD against IS. Furthermore, this study demonstrated the feasibility of combining proteomics with systems pharmacology to study the mechanism of herbal medicine.

The protective effect and mechanism of glycosides of cistanche deserticola on rats in middle cerebral artery occlusion (MCAO) model

ABSTRACT Cerebral ischemia-reperfusion injury (CIRI) occurs frequently clinically as a complication following cardiovascular resuscitation resulting in neuronal damage specifically to the hippocampal CA1 region with consequent cognitive impairment. Apoptosis and oxidative stress were proposed as major risk factors associated with CIRI development. Previously, glycosides obtained from Cistanche deserticola (CGs) were shown to play a key role in counteracting CIRI; however, the underlying mechanisms remain to be determined. This study aimed to investigate the neuroprotective effect of CGs on subsequent CIRI in rats. The model of CIRI was established for 2 hr and reperfusion for 24 hr by middle cerebral artery occlusion (MCAO) model. The MCAO rats were used to measure the antioxidant and anti-apoptotic effects of CGs on CIRI. Neurological function was evaluated by the Longa neurological function score test. 2,3,5-Triphenyltetrazolium chloride (TTC) staining was used to detect the area of cerebral infarction. Nissl staining was employed to observe neuronal morphology. TUNEL staining was used to detect neuronal apoptosis, while Western blot determined protein expression levels of factors for apoptosis-related and PI3K/AKT/Nrf2 signaling pathway. Data demonstrated that CGs treatment improved behavioral performance, brain injury, and enhanced antioxidant and anti-apoptosis in CIRI rats. In addition, CGs induced activation of PI3K/AKT/Nrf2 signaling pathway accompanied by inhibition of the expression of apoptosis-related factors. Evidence indicates that CGs amelioration of CIRI involves activation of the PI3K/AKT/Nrf2 signaling pathway associated with increased cellular viability suggesting these glycosides may be considered as an alternative compound for CIRI treatment.

Salidroside derivative SHPL-49 attenuates glutamate excitotoxicity in acute ischemic stroke via promoting NR2A-CAMKⅡα-Akt /CREB pathway

BackgroundIschemic stroke is a significant cause of death and disability with a limited treatment time window. The reduction of early glutamate excitotoxicity using neuroprotective agents targeting N-methyl-D-aspartic acid (NMDA) receptors have attracted recent research attention. SHPL-49, a structurally modified derivative of salidroside, was synthesized by our team. Previous studies have confirmed the neuroprotective efficacy of SHPL-49 in rats with ischemic stroke. However, the underlying mechanisms need to be clarified. MethodsWe conducted in vivo experiments using the permanent middle cerebral artery occlusion rat model to investigate the role of SHPL-49 in glutamate release at different time points and treatment durations. Glutamate transporters and receptor proteins and neural survival proteins in the brain were also examined at the same time points. In vitro, primary neurons and the coculture system of primary neurons–astrocytes were subjected to oxygen–glucose deprivation and glutamate injury. Proteomics and parallel reaction monitoring analyses were performed to identify potential therapeutic targets of SHPL-49, which were further confirmed through in vitro experiments on the inhibition and mutation of the target. ResultsSHPL-49 significantly reduced glutamate release caused by hypoxia–ischemia. One therapeutic pathway of SHPL-49 was promoting the expression of glutamate transporter-1 to increase glutamate reuptake and further reduce the occurrence of subsequent neurotoxicity. In addition, we explored the therapeutic targets of SHPL-49 and its regulatory effects on glutamate receptors for the first time. SHPL-49 enhanced neuroprotection by activating the NMDA subunit NR2A, which upregulated the cyclic-AMP response binding protein (CREB) neural survival pathway and Akt phosphorylation. Since calcium/calmodulin-dependent kinase IIα (CaMKIIα) is necessary for synaptic transmission of NMDA receptors, we explored the interaction between CaMKIIα and SHPL-49, which protected CaMKIIα from hypoxia–ischemia-induced autophosphorylation damage. ConclusionOverall, SHPL-49 enhanced neuronal survival and attenuated acute ischemic stroke by promoting the NR2A–CAMKⅡα–Akt/CREB pathway. Our study provides the first evidence demonstrating that the neuroprotective effect of SHPL-49 is achieved by promoting the NR2A subunit to extend the treatment time window, making it a promising drug for ischemic stroke.

Electroacupuncture Alleviates Post-stroke Cognitive Impairment Through Inhibiting miR-135a-5p/mTOR/NLRP3 Axis-mediated Autophagy

Post-stroke cognitive impairment is a significant challenge with limited treatment options. Electroacupuncture (EA) has shown promise in improving cognitive function after stroke. Our study explores the underlying mechanism of EA in alleviating cognitive impairment through the inhibition of autophagy. We utilized a rat model of stroke induced by middle cerebral artery occlusion (MCAO) to evaluate the efficacy of EA. Treatment with EA was observed to markedly improve cognitive function and reduce inflammation in MCAO rats, as evidenced by decreased neurological deficit scores, shorter latencies in the water maze test, and diminished infarct volumes. EA also attenuated tissue damage in the hippocampus and lowered the levels of pro-inflammatory cytokines and oxidative stress markers. Although autophagy was upregulated in MCAO rats, EA treatment suppressed this process, indicated by a reduction in autophagosome formation and alteration of autophagy-related protein expression. The protective effects of EA were reversed by the autophagy activator rapamycin. EA treatment elevated the levels of microRNA (miR)-135a-5p expression, and suppression of this elevation attenuated the remedial efficacy of EA in addressing cognitive impairment and inflammation. MiR-135a-5p targeted mammalian target of rapamycin (mTOR)/NOD-like receptor protein 3 (NLRP3) signaling to repress autophagy. EA treatment inhibits autophagy and alleviates cognitive impairment in post-stroke rats. It exerts its beneficial effects by upregulating miR-135a-5p and targeting the mTOR/NLRP3 axis.

Mechanism of astragaloside IV regulating NLRP3 through LOC102555978 to attenuate cerebral ischemia reperfusion induced microglia pyroptosis

Astragaloside IV(ASⅣ), the main component of Radix Astragali, has been used to treat cerebral ischemia reperfusion injury (CIRI). However, the molecular mechanism of ASIV in CIRI needs to be further elucidated. Long non-coding RNA (lncRNA) is considered to be an important kind of regulatory molecule in CIRI. In this work, the biological effect and molecular mechanism of ASIV in CIRI through lncRNA were analyzed by using rat middle cerebral artery occlusion and reperfusion (MCAO/R) model and primary rat microglia (RM) cells oxygen and glucose deprivation/reoxygenation (OGD/R) model. The neurological deficit score was evaluated, the volume of cerebral infarction was calculated, and pyroptosis related molecules were detected by qPCR and western blot. Then, high-throughput sequencing was performed in sham and MCAO/R groups. The competitive endogenous RNA (ceRNA) networks associated with pyroptosis were constructed by functional enrichment analysis. CCK-8 detection of cell survival rate, qPCR and western blot were used to determine the specific molecular mechanism of ASⅣ through ceRNA in vitro. Results showed thatASⅣ could decrease the neurological deficit score, reduce the volume of cerebral infarction, inhibit inflammatory reaction and pyroptosis in MCAO/R model rats. Next, the ceRNA network was established, including the LOC102555978/miR-3584-5p/NLRP3 regulatory network. In vitro experiments showed that LOC102555978 promotes NLRP3 mediated pyroptosis of RM cells through sponge adsorption of miR-3584-5p, which may provide a potential therapeutic target for post-CIRI inflammation regulation. ASⅣ could inhibit pyroptosis of RM cells by down-regulating LOC102555978. LOC102555978/miR-3584-5p/NLRP3 may be the molecular mechanism of ASⅣ's CIRI protective effect.

Differential impact of unilateral stroke on the bihemispheric motor cortex representation of the jaw and tongue muscles in young and aged rats.

Dysphagia commonly occurs after stroke, yet the mechanisms of post-stroke corticobulbar plasticity are not well understood. While cortical activity associated with swallowing actions is bihemispheric, prior research has suggested that plasticity of the intact cortex may drive recovery of swallowing after unilateral stroke. Age may be an important factor as it is an independent predictor of dysphagia after stroke and neuroplasticity may be reduced with age. Based on previous clinical studies, we hypothesized that cranial muscle activating volumes may be expanded in the intact hemisphere and would contribute to swallowing function. We also hypothesized that older age would be associated with limited map expansion and reduced function. As such, our goal was to determine the impact of stroke and age on corticobulbar plasticity by examining the jaw and tongue muscle activating volumes within the bilateral sensorimotor cortices. Using the middle cerebral artery occlusion rat stroke model, intracortical microstimulation (ICMS) was used to map regions of sensorimotor cortex that activate tongue and jaw muscles in both hemispheres. Young adult (7 months) and aged (30 months) male F344 × BN rats underwent a stroke or sham-control surgery, followed by ICMS mapping 8 weeks later. Videofluoroscopy was used to assess oral-motor functions. Increased activating volume of the sensorimotor cortex within the intact hemisphere was found only for jaw muscles, whereas significant stroke-related differences in tongue activating cortical volume were limited to the infarcted hemisphere. These stroke-related differences were correlated with infarct size, such that larger infarcts were associated with increased jaw representation in the intact hemisphere and decreased tongue representation in the infarcted hemisphere. We found that both age and stroke were independently associated with swallowing differences, weight loss, and increased corticomotor thresholds. Laterality of tongue and jaw representations in the sham-control group revealed variability between individuals and between muscles within individuals. Our findings suggest the role of the intact and infarcted hemispheres in the recovery of oral motor function may differ between the tongue and jaw muscles, which may have important implications for rehabilitation, especially hemisphere-specific neuromodulatory approaches. This study addressed the natural course of recovery after stroke; future work should expand to focus on rehabilitation.

The Optimization Design of Macrophage Membrane Camouflaging Liposomes for Alleviating Ischemic Stroke Injury through Intranasal Delivery.

Ischemic stroke is associated with a high mortality rate, and effective treatment strategies are currently lacking. In this study, we aimed to develop a novel nano delivery system to treat ischemic stroke via intranasal administration. A three-factor Box-Behnken experimental design was used to optimize the formulation of liposomes co-loaded with Panax notoginseng saponins (PNSs) and Ginsenoside Rg3 (Rg3) (Lip-Rg3/PNS). Macrophage membranes were coated onto the surface of the optimized liposomes to target the ischemic site of the brain. The double-loaded liposomes disguised by macrophage membranes (MM-Lip-Rg3/PNS) were spherical, in a "shell-core" structure, with encapsulation rates of 81.41% (PNS) and 93.81% (Rg3), and showed good stability. In vitro, MM-Lip-Rg3/PNS was taken up by brain endothelial cells via the clathrin-dependent endocytosis and micropinocytosis pathways. Network pharmacology experiments predicted that MM-Lip-Rg3/PNS could regulate multiple signaling pathways and treat ischemic stroke by reducing apoptosis and inflammatory responses. After 14 days of treatment with MM-Lip-Rg3/PNS, the survival rate, weight, and neurological score of middle cerebral artery occlusion (MCAO) rats significantly improved. The hematoxylin and eosin (H&E) and TUNEL staining results showed that MM-Lip-Rg3/PNS can reduce neuronal apoptosis and inflammatory cell infiltration and protect the ischemic brain. In vivo biological experiments have shown that free Rg3, PNS, and MM-Lip-Rg3/PNS can alleviate inflammation and apoptosis, especially MM-Lip-Rg3/PNS, indicating that biomimetic liposomes can improve the therapeutic effects of drugs. Overall, MM-Lip-Rg3/PNS is a potential biomimetic nano targeted formulation for ischemic stroke therapy.

Electroacupuncture regulates histone acetylation of Bcl-2 and Caspase-3 genes to improve ischemic stroke injury

BackgroundImbalances between Bcl-2 and caspase-3 are significant evidence of apoptosis, which is considered an influential factor in rapidly occurring neuronal cell death and the decline of neurological function after stroke. Studies have shown that acupuncture can reduce poststroke brain cell damage via either an increase in Bcl-2 or a reduction in caspase-3 exposure. The current study aimed to investigate whether acupuncture could modulate Bcl-2 and caspase-3 expression through histone acetylation modifications, which could potentially serve as a neuroprotective mechanism. MethodsThis study used TTC staining, Nissl staining, Clark neurological system score, and Evans Blue (EB) extravasation to evaluate neurological damage following stroke. The expression of Bcl-2/caspase-3 mRNA was detected by real-time fluorescence quantification of PCR (real-time PCR), whereas the protein expression levels of Bcl-2, Bax, caspase-3, and cleaved caspase-3 were assessed using western blotting. TUNEL staining of the ischemic cortical neurons determined apoptosis in the ischemic cortex. Histone acetyltransferase (HAT) and histone deacetylase (HDAC) activities, along with the protein performance of AceH3, H3K9ace, and H3K27ace, were detected to evaluate the degree of histone acetylation. The acetylation enrichment levels of H3K9 and K3K27 in the Bcl-2/caspase-3 gene were assessed using Chromatin Immunoprecipitation (ChIP) assay. ResultsOur data demonstrated that electroacupuncture (EA) exerts a significant neuroprotective effect in middle cerebral artery occlusion (MCAO) rats, as evidenced by a reduction in infarct volume, neuronal damage, Blood-Brain Barrier (BBB) disruption, and decreased apoptosis of ischemic cortical neurons. EA treatment can promote the mRNA and protein expression of the Bcl-2 gene in the ischemic brain while reducing the mRNA and protein expression levels of caspase-3 and effectively decreasing the protein expression levels of Bax and cleaved caspase-3. More importantly, EA treatment enhanced the level of histone acetylation, including Ace-H3, H3K9ace, and H3K27ace, significantly enhanced the occupancy of H3K9ace/H3K27ace at the Bcl-2 promoter, and reduced the enrichment of H3K9ace and H3K27ace at the caspase-3 promoter. However, the Histone Acetyltransferase inhibitor (HATi) treatment reversed these effects. ConclusionsOur data demonstrated that EA mediated the expression levels of Bcl-2 and caspase-3 in MCAO rats by regulating the occupancy of acetylated H3K9/H3K27 at the promoters of these two genes, thus exerting a cerebral protective effect in ischemic reperfusion (I/R) injury.

Enriched environment treatment promotes neural functional recovery together with microglia polarization and remyelination after cerebral ischemia in rats

BackgroundMicroglia activation and oligodendrocyte maturation are critical for remyelination after cerebral ischemia. Studies have shown that enriched environment (EE) can effectively alleviate stroke-induced neurological deficits. However, little is known about the mechanism associated with glial cells underlying the neuroprotection of EE. Therefore, this study focuses on investigating the effect of EE on activated microglia polarization as well as oligodendrogenesis in the progress of remyelination following cerebral ischemia. MethodsThe ischemia/reperfusion (I/R) injury model was established by middle cerebral artery occlusion (MCAO) in rats. Animals executed 4 weeks of environmental intervention after performing MCAO or sham surgery and were divided into sham, MCAO, and MCAO+EE groups. Cognitive function, myelin damage, microglia activation and polarization, inflammation, oligodendrogenesis, remyelination, and protein expression of the PI3K/AKT/GSK3β signaling pathway were determined. ResultsThe staining of NeuN indicated that the infarct size of MCAO rats was decreased under EE. EE intervention improved animal performance in the Morris water maze test and novel object recognition test, promoting the recovery of cognitive function after I/R injury. EE treatment alleviated myelin damage in MCAO rats, as evidenced by the lower fluorescence intensity ratio of SMI-32/MBP in MCAO+EE group. EE increased the fluorescence intensity ratio of NG2+/Ki67+/Olig2+, MBP, and MOG, enhancing the proliferation and differentiation of OPCs and oligodendrogenesis after MCAO. In terms of remyelination, more myelinated axons and lower G/ratio were detected in MCAO+EE rats compared with MCAO group. Moreover, EE treatment decreased the number of Iba1+/CD86+ M1 microglia, increased the number of Iba1+/CD206+ M2 microglia, and suppressed the inflammation response after I/R injury, which could be attributed to the augmented expression of PI3K/AKT/GSK3β axis. ConclusionEE improved long‑term recovery of cognitive function after cerebral I/R injury, at least in part by promoting M2 microglia transformation through activation of the PI3K/AKT/GSK3β signaling pathway, inhibiting inflammation to provide a favorable microenvironment for oligodendrocyte maturation and remyelination. The effect of the EE on myelin and inflammation could account for the neuroprotection provided by EE.

Blocking cerebral lymphatic system reduces central and peripheral inflammatory response in ischemic stroke

Reduced blood supply to the brain activates the intracranial inflammatory response, a key contributor to secondary brain damage in ischemic stroke. Post-stroke, activation of peripheral immune cells leads to systemic inflammatory responses. Usingin vivo approaches, we investigated meningeal lymphatics’ role in central immune cell infiltration and peripheral immune cell activation. The bilateral deep cervical lymph nodes (dCLNs) were removed 7 days before right middle cerebral artery occlusion in Sprague Dawley (SD) rats. At 3, 24, and 72 h post-intervention, brain immune cell infiltration and microglial and astrocyte activation were measured, while immune cells were classified in the spleen and blood. Inflammatory factor levels in peripheral blood were analyzed. Simultaneously, reverse verification was conducted by injecting AAV-vascular endothelial growth factor C (AAV-VEGFC) adenovirus into the lateral ventricle 14 days before middle cerebral artery occlusion (MCAO) induction to enhance meningeal lymph function. Blocking meningeal LVs in MCAO rats significantly reduced infarct area and infiltration, and inhibited microglia and pro-inflammatory astrocytes activation. After removing dCLNs, CD4+ T lymphocytes, CD8+ T lymphocytes, B lymphocytes, macrophages, and neutrophils in the spleen and blood of MCAO rats decreased significantly at different time points. The levels of inflammatory factors IL-6, IL-10, IL-1β, and TNF-α in plasma decreased significantly. Tests confirmed the results, and AAV-VEGFC-induced MCAO rats provided reverse validation.

Electroacupuncture Alleviates Cerebral Ischemia-reperfusion Injury by Regulating the S1PR2/TLR4/NLRP3 Signaling Pathway via m6A Methylation of lncRNA H19.

All rats were randomly divided into five groups: the SHAM group, MCAO group, MCAO+EA (MEA) group, MCAO+METTL3 overexpression+EA (METTL3) group and MCAO+lncRNA H19 overexpression+EA (lncRNA H19) group. The middle cerebral artery occlusion (MCAO) rats were established to mimic CIR injury. The overexpression of lncRNA H19 and METTL3 was induced by stereotactic injection of lentiviruses into the rat lateral ventricles. The rats in the MEA, METTL3, and lncRNA H19 groups were treated with EA therapy on "Renzhong" (DU26) and "Baihui" (DU20) acupoints (3.85/6.25Hz; 1mA). Besides, the neurological deficit scoring, cerebral infarction area, pathological changes in brain tissue, total RNA m6A level, and the expression of METTL3, S1PR2, TLR4, NLRP3 and lncRNA H19 were detected in this experiment. EA improved the neurological deficit scoring, cerebral infarction area, and pathological injury in MCAO rats, while these beneficial effects of EA on CIR injury were attenuated by the overexpression of METTL3 or lncRNA H19. More importantly, EA down-regulated the total RNA m6A level and the expression of METTL3, S1PR2, TLR4, NLRP3 and lncRNA H19 in MCAO rats. Instead, the overexpression of METTL3 or lncRNA H19 was found to reverse the EA-induced down-regulation. The findings indicated that EA might down-regulate the S1PR2/TLR4/NLRP3 signaling pathway via m6A methylation of lncRNA H19 to alleviate CIR injury. Our findings provide a new insight into the molecular mechanism of EA on CIR injury.

Modulating gut microbiota improves neurological function and depressive symptoms in rats with post-stroke depression

To evaluate the effect of modulating gut microbiota for improving brain injury in rats with post-stroke depression. Adult SD rats were randomized into normal control, middle cerebral artery occlusion (MCAO), post-stroke depression (PSD), PSD with fecal transplantation, PSD with antibiotics (rifaximin), PSD with probiotics (lactobacilli), and PSD with fluoxetine treatment groups (n=9). Neurological function scores of the rats were determined, and the changes in sugar water preference and immobility time in forced swimming test were observed; plasma levels of trimethylamine N-oxide (TMAO) and hydrogen sulfide (H2S) were detected with ELISA, Occludin, and the expressions of occludin, caudin-5 and IgG proteins Ⅰ the brain tissues were determined using Western blotting. Compared with those in the control group, the rats in MCAO and PSD groups had significantly increased neurological function scores, TMAO level, the ratio of TMAO/H2S, and immobility time in forced swimming test with a lowered level of H2S (P < 0.05). These changes were more obvious in PSD rats, which also exhibited a reduced sugar water preference with increased IgG protein and decreased occluding and caudin-5 expressions in the brain tissue (P < 0.05). TMAO/H2S ratio in PSD rats was positively correlated with neurological function score (R2=0.3235, P=0.0269) and immobility time in swimming (R2=0.6290, P=0.0004) and negatively with sugar water preference (R2=-0.4534, P=0.0059). Treatment with fecal transplantation, antibiotics, probiotics and fluoxetine all significantly reduced neurological function scores, immobility time in forced swimming, TMAO/H2S ratio, and IgG protein expression and increased sugar water preference and brain occludin and caudin-5 expressions of the PSD rats (P < 0.05). In PSD rats, TMAO/H2S ratio is correlated with neurological function score, immobility time in forced swimming and sugar water preference, and modulating intestinal flora can improve neurological function and depressive symptoms and improve the integrity of the blood-brain barrier.