Cerebral Infarct Volume Research Articles

Enhanced effect of limb remote ischemic postconditioning combined with paeoniflorin on alleviating cerebral ischemic injury via neutrophil NADPH pathway

BackgroundLimb remote ischemic postconditioning (LRIP) and paeoniflorin (PF) both can ameliorate cerebral ischemia reperfusion (I/R) injury. At present, whether LRIP combined with PF can achieve better therapeutic effect is unknown. PurposeThis study explored the alleviating effect and mechanism of LRIP in combination with PF on cerebral I/R injury in rats. MethodsMiddle cerebral artery occlusion (MCAO) surgery was performed on rats except Sham group. Then PF (2.5 mg/kg, 5 mg/kg, 10 mg/kg) was administrated by intraperitoneal injection 10 min before the start of reperfusion. LRIP was operated on the left femoral artery at 0 h of reperfusion. Behavioral testing was used to assess neurological impairment, while TTC staining was used to examine infarct volume. Protein expression of MyD88, TRAF6, p38-MAPK and phosphorylation of p47phox in neutrophils from rat peripheral blood were tested by Western blot. Rat bone marrow neutrophils were extracted and incubated for 24 h with serum from rats after LRIP combined with PF. p38 MAPK inhibitor group was administrated SB203580 while the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitor group was administrated Apocynin. Neutrophils were stimulated by fMLP (10 μM). Reactive oxygen species (ROS) production and protein expression of MyD88, TRAF6, p38 MAPK, and p47phox (ser 304 and ser 345) were detected. ResultsLRIP combined with PF (5 mg/kg) reduced cerebral infarct volume, ameliorated neurological deficit score (NDS), decreased fMLP-stimulated ROS release and downregulated the protein expression of MyD88, TRAF6, p38-MAPK and phosphorylation of p47phox (ser 304 and ser 345) in neutrophils. ConclusionThe protective effect of LRIP combined with PF on cerebral I/R injury was better than either alone. Taken together, we provided solid evidence to demonstrate that the combination of LRIP and PF had potential to alleviate cerebral I/R injury, which was regulated by MyD88-TRAF6-p38 MAPK pathway and neutrophil NADPH oxidase pathway.

Moxibustion Promoted Axonal Regeneration and Improved Learning and Memory of Post-stroke Cognitive Impairment by Regulating PI3K/AKt and TACC3

BackgroundThis study aimed to investigate whether moxibustion could affect PI3K/Akt pathway to regulate Transforming acidic coiled-coil containing protein 3 (TACC3) and promote axonal regeneration to improve learning and memory function in middle cerebral artery occlusion (MCAO) rats. MethodsSixty SD rats were randomly divided into 4 groups: sham-operated control group (SC), model control group (MC), model + moxibustion group (MM), and model + inhibitor + moxibustion group (MIM). The rats in MC, MM, and MIM groups were made into MCAO models, and PI3K inhibitor LY294002 was injected into the rats in MIM group before modeling; while the rats in SC group were only treated with artery separation without monofilament inserting. After that, the rats in MM and MIM groups were intervented with moxibustion. We used the Zea-Longa scale, micro-Magnetic Resonance Imaging (micro-MRI), Morris water maze (MWM), TUNEL, western blot (WB), immunofluorescence and immunohistochemistry to evaluate the neurological deficits, cerebral infarct volume, learning and memory, apoptotic cell percentage in the hippocampal, the expression level of axonal regeneration and PI3K/AKt related proteins, the expression level of TACC3. The detection of 2 h after surgery showed the result before moxibustion and 7 days after the intervention showed the results after moxibustion. ResultsAfter 7 d of intervention, the scores of Zea-Longa and the cerebral infarct volume, the escape latency, the percentage of apoptosis cells of MM group were lower than that of MC and MIM groups; the frequency of rats crossed the previous platform location, PI3K, p-Akt/t-Akt and TACC3, the level of GAP-43 in MM group was more than MC and MIM groups (P < 0.05). While no statistical difference existed between MIM group and MC group (P > 0.05). ConclusionMoxibustion can promote axonal regeneration and improve learning and memory of Post-stroke cognitive impairment via activating the PI3K/AKT signaling pathway and TACC3.

SIRT3 facilitates mitochondrial structural repair and functional recovery in rats after ischemic stroke by promoting OPA1 expression and activity

BackgroundOptical atrophy 1 (OPA1), a protein accountable for mitochondrial fusion, facilitates the restoration of mitochondrial structure and function following cerebral ischemia/reperfusion (I/R) injury. The OPA1-conferred mitochondrial protection involves its expression and activity, which can be improved by SIRT3 in non-cerebral ischemia. Nevertheless, it remains obscure whether SIRT3 enhances the expression and activity of OPA1 after cerebral I/R injury. MethodsMature male Sprague Dawley rats were intracranially injected with adeno-associated viral-Sirtuin-3(AAV-SIRT3) and AAV-sh_OPA1, followed by a 90-min temporary blockage of the middle cerebral artery and subsequent restoration of blood flow. Cultured cortical neurons of rats were transfected with LV-SIRT3 or LV-sh_OPA1 before a 2-h oxygen-glucose deprivation and reoxygenation. The rats and neurons were subsequently treated with a selective OPA1 activity inhibitor (MYLS22). The interaction between SIRT3 and OPA1 was assessed by molecular dynamics simulation technology and co-immunoprecipitation. The expression, function, and specific protective mechanism of SIRT3 were examined by various analyses. ResultsSIRT3 interacted with OPA1 in the rat cerebral cortex before and after cerebral I/R. After cerebral I/R damage, SIRT3 upregulation increased the OPA1 expression, which enhanced deacetylation and OPA1 activity, thus alleviating cerebral infarct volume, neuronal apoptosis, oxidative pressure, and impairment in mitochondrial energy production; SIRT3 upregulation also improved neuromotor performance, repaired mitochondrial ultrastructure and membrane composition, and promoted the mitochondrial biogenesis. These neuroprotective effects were partly reversed by OPA1 expression interference and OPA1 activity inhibitor MYLS22. ConclusionIn rats, SIRT3 enhances the expression and activity of OPA1, facilitating the repair of mitochondrial structure and functional recovery following cerebral I/R injury. These findings highlight that regulating SIRT3 may be a promising therapeutic strategy for ischemic stroke.

Electroacupuncture Downregulating Neuronal Ferroptosis in MCAO/R Rats by Activating Nrf2/SLC7A11/GPX4 Axis

Ischemic stroke involves various pathological processes, among which ferroptosis is crucial. Previous studies by our group have indicated that electroacupuncture (EA) mitigates ferroptosis after ischemic stroke; however, the precise mechanism underlying this effect remains unclear. In the present study, we developed a rat model of middle cerebral artery occlusion/reperfusion. We chose the main acupoint of the treatment methods of the “Awakening and Opening of the Brain”. Rats’ neurological function and motor coordination were evaluated by neurological function score and the rotarod test, respectively, and the volume of cerebral infarction was analyzed by 2,3,5-triphenyltetrazolium chloride Staining. The cerebrovascular conditions were visualized by time-of-flight magentic resonance angiography. In addition, we detected changes in lipid peroxidation and endogenous antioxidant activity by measuring the malondialdehyde, glutathione, superoxide dismutase activities, glutathione/oxidized glutathione and reduced nicotinamide adenine dinucleotide phosphate/oxidized nicotinamide adenine dinucleotide phosphate ratios. Inductively coupled plasma-mass spectrometry, western blot, reverse transcription-polymerase chain reaction, fluoro-jade B staining, immunofluorescence analysis, and transmission electron microscopy were utilized to examine the influence of EA. The results indicate that EA treatment was effective in reversing neurological impairment, neuronal damage, and protecting mitochondrial morphology and decreasing the cerebral infarct volume in the middle cerebral artery occlusion/reperfusion rat model. EA reduced iron levels, inhibited lipid peroxidation, increased endogenous antioxidant activity, modulated the expression of several ferroptosis-related proteins, and promoted nuclear factor-E2-related factor 2 (Nrf2) nuclear translocation. However, the protective effect of EA was hindered by the Nrf2 inhibitor ML385. These findings suggest that EA can suppress ferroptosis and decrease damage caused by cerebral ischemia/reperfusion by activating Nrf2 and increasing the protein expression of solute carrier family 7 member 11 and glutathione peroxidase 4.

Phelligridimer A enhances the expression of mitofusin 2 and protects against cerebral ischemia/reperfusion injury

Mitochondrial dysfunction and endoplasmic reticulum (ER) stress play pivotal roles in the pathology of cerebral ischemia. In this study, we investigated whether phelligridimer A (PA), an active compound isolated from the medicinal and edible fungus Phellinus igniarius, ameliorates ischemic cerebral injury by restoring mitochondrial function and restricting ER stress. An in vitro cellular model of ischemic stroke-induced neuronal damage was established by exposing HT-22 neuronal cells to oxygen-glucose deprivation/reoxygenation (OGD/R). An in vivo animal model was established in rats subjected to middle cerebral artery occlusion/reperfusion (MCAO/R). The results showed that PA (1–10 μM) dose-dependently increased HT-22 cell viability, reduced OGD/R-induced lactate dehydrogenase release, and reversed OGD/R-induced apoptosis. PA reduced OGD/R-induced accumulation of reactive oxygen species, restored mitochondrial membrane potential, and increased ATP levels. Additionally, PA reduced the expression of the 78-kDa glucose-regulated protein (GRP78) and the phosphorylation of inositol-requiring enzyme-1α (p-IRE1α) and eukaryotic translation-initiation factor 2α (p-eIF2α). PA also inhibited the activation of the mitogen-activated protein kinase (MAPK) pathway in the OGD/R model. Moreover, treatment with PA restored the expression of mitofusin 2 (Mfn-2), a protein linking mitochondria and ER. The silencing of Mfn-2 abolished the protective effects of PA. The results from the animal study showed that PA (3–10 mg/kg) significantly reduced the volume of cerebral infarction and neurological deficits, which were accompanied by an increased level of Mfn-2, and decreased activation of the ER stress in the penumbra of the ipsilateral side after MCAO/R in rats. Taken together, these results indicate that PA counteracts cerebral ischemia-induced injury by restoring mitochondrial function and reducing ER stress. Therefore, PA might be a novel protective agent to prevent ischemia stroke-induced neuronal injury.

JR14a: A novel antagonist of C3aR attenuates neuroinflammation in cerebral ischemia-reperfusion injury

Cerebral ischemia-reperfusion injury (CIRI), a prevalent stroke-related complication, can lead to severe brain damage. Inflammation is a crucial factor in CIRI pathogenesis, and the complement component 3a receptor (C3aR) could be a key mediator in the post-CIRI inflammatory cascade. In this study, the role of C3aR in CIRI was investigated utilizing a middle cerebral artery occlusion (MCAO) model in C3aR knockout (KO) mice. Magnetic resonance imaging (MRI) and neurofunctional assessments revealed that C3aR KO mice exhibited significantly diminished cerebral infarction and improved neurological impairments. Consequently, the focus shifted to searching for a small molecule antagonist of C3aR. JR14a, a new potent thiophene antagonist of C3aR, was injected intraperitoneally into mice 1-h post-MCAO model implementation. The mass spectrometry (MS) results indicated the ability of JR14a to penetrate the blood-brain barrier. Subsequent TTC staining and neurofunctional assessments revealed the efficacy of JR14a in reducing cerebral infarct volume and neurological impairment following MCAO. In addition, immunofluorescence (IF) and immunohistochemistry (IHC) demonstrated attenuated microglial activation, neutrophil infiltration, and blood-brain barrier disruption by JR14a in the MCAO model. Furthermore, enzyme-linked immunosorbent assay (ELISA) and Western blotting supported the role of JR14a in downregulating the expression levels of C3aR, tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6), as well as the phosphorylation of p65. In conclusion, the findings suggested that C3aR could be a potential therapeutic target for CIRI, and JR14a emerged as a promising treatment candidate.

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.

Treating ischemic stroke by improving vascular structure and promoting angiogenesis using Taohong Siwu Decoction: An integrative pharmacology strategy

Ethnopharmacological relevanceNeovessels represent a crucial therapeutic target and strategy for repairing ischemic tissue. Taohong Siwu Decoction (THSWD) exhibits potential in promoting angiogenesis to address ischemic stroke (IS). However, its impact on neovessel structure and function, alongside the underlying molecular mechanisms, remains elusive. Aim of the studyOur aim is to investigate the protective effects of THSWD on neovessel structure and function, as well as the associated molecular mechanisms, utilizing an integrative pharmacological approach. Materials and methodsWe initially employed behavioral tests, 2,3,5-triphenyltetrazolium chloride (TTC) staining, Haematoxylin-eosin (HE) staining, enzyme-linked immunosorbent assay (ELISA), Laser Doppler flowmetry (LDF), Evans blue staining, and immunofluorescence to evaluate the protective effects of THSWD on neovascular structure and function in middle cerebral artery occlusion/reperfusion (MCAO/R) rats. Subsequently, we utilized network pharmacology, metabolomics, and experimental validation to elucidate the underlying molecular mechanisms of THSWD in enhancing neovascular structure and function. ResultIn addition to significantly reducing neurological deficits and cerebral infarct volume, THSWD mitigated pathological damage, blood-brain barrier (BBB) leakage, and cerebral blood flow disruption. Moreover, it preserved neovascular structure and stimulated angiogenesis. THSWD demonstrated potential in ameliorating cerebral microvascular metabolic disturbances including lipoic acid metabolism, fructose and mannose metabolism, purine metabolism, and ether lipid metabolism. Consequently, it exhibited multifaceted therapeutic effects, encompassing anti-inflammatory, antioxidant, energy metabolism modulation, and antiplatelet aggregation properties. ConclusionTHSWD exhibited protective effects on cerebral vascular structure and function and facilitated angiogenesis by rectifying cerebral microvascular metabolic disturbances in MCAO/R rats. Furthermore, integrated pharmacology offers a promising approach for studying the intricate traditional Chinese medicine (TCM) system in IS treatment.

Comprehensive evaluation of the mechanism of Banxia Baizhu Tianma Decoction in ameliorating posterior circulation ischemia vertigo based on integrating fecal short-chain fatty acids and 16S rRNA sequencing

Posterior circulation ischemia vertigo (PCIV) is vertebrobasilar insufficiency resulting in vertigo. Banxia Baizhu Tianma Decoction (BBTD) is broadly applied to treat PCIV in China, but its efficacy and detailed mechanism remains unclear. Therefore, this study aims to investigate the effects of BBTD on PCIV, and identify important gut microbiota and its derived short-chain fatty acid (SCFA) changes and the detailed mechanism through 16 S rRNA sequencing with SCFAs profiling. In this study, the model of PCIV was established by surgical ligation of the right subclavian artery (RSCA) and right common carotid artery (RCCA). We found that BBTD administration effectively reduced the volume of cerebral infarction and improved neurologic functions, reduced neuronal apoptosis and neuroinflammatory. Moreover, BBTD significantly modulated the diversity and composition of the gut microbiota, including increasing the relative abundance of Lactobacillus, Prevotella and Akkermansia and decreasing relative abundances of Lachnospiraceae, Bacteroidetes (S24–7) and Ruminococcaceae. BBTD treatment also increased propionate content. Propionate mediates the the recovery of neurological functions and anti-apoptotic effects of BBTD in PCIV rat. Our findings wish to discover the potential mechanism of BBTD treatment on PCIV and promote its clinical application.

The activation of AMPK/PGC-1α/GLUT4 signaling pathway through early exercise improves mitochondrial function and mitigates ischemic brain damage.

Mitochondria play a crucial role in maintaining cellular energy supply and serve as a source of energy for repairing nerve damage following a stroke. Given that exercise has the potential to enhance energy metabolism, investigating the impact of exercise on mitochondrial function provides a plausible mechanism for stroke treatment. In our study, we established the middle cerebral artery occlusion (MCAO) model in Sprague-Dawley rats and implemented early exercise intervention. Neurological severity scores, beam-walking test score, and weight were used to evaluate neurological function. The volume of cerebral infarction was measured by MRI. Nerve cell apoptosis was detected by TUNEL staining. Mitochondrial morphology and structure were detected by mitochondrial electron microscopy. Mitochondrial function was assessed using membrane potential and ATP measurements. Western blotting was used to detect the protein expression of AMPK/PGC-1α/GLUT4. Through the above experiments, we found that early exercise improved neurological function in rats after MCAO, reduced cerebral infarction volume and neuronal apoptosis, promoted the recovery of mitochondrial morphology and function. We further examined the protein expression of AMPK/PGC-1α/GLUT4 signaling pathway and confirmed that early exercise was able to increase its expression. Therefore, we suggest that early exercise initiated the AMPK/PGC-1α/GLUT4 signaling pathway, restoring mitochondrial function and augmenting energy supply. This, in turn, effectively improved both nerve and body function in rats following ischemic stroke.

Normobaric Hyperoxia Combined With Endovascular Treatment Based on Temporal Gradient: A Dose-Escalation Study.

Normobaric hyperoxia (NBO) has neuroprotective effects in acute ischemic stroke. Thus, we aimed to identify the optimal NBO treatment duration combined with endovascular treatment. This is a single-center, randomized controlled, open-label, blinded-end point dose-escalation clinical trial. Patients with acute ischemic stroke who had an indication for endovascular treatment at Tianjin Huanhu Hospital were randomly assigned to 4 groups (1:1 ratio) based on NBO therapy duration: (1) control group (1 L/min oxygen for 4 hours); (2) NBO-2h group (10 L/min for 2 hours); (3) NBO-4h group (10 L/min for 4 hours); and (4) NBO-6h group (10 L/min for 6 hours). The primary outcome was cerebral infarction volume at 72 hours after randomization using an intention-to-treat analysis model. The primary safety outcome was the 90-day mortality rate. Between June 2022 and September 2023, 100 patients were randomly assigned to the following groups: control group (n=25), NBO-2h group (n=25), NBO-4h group (n=25), and NBO-6h group (n=25). The 72-hour cerebral infarct volumes were 39.4±34.3 mL, 30.6±30.1 mL, 19.7±15.4 mL, and 22.6±22.4 mL, respectively (P=0.013). The NBO-4h and NBO-6h groups both showed statistically significant differences (adjusted P values: 0.011 and 0.027, respectively) compared with the control group. Compared with the control group, both the NBO-4h and NBO-6h groups showed significant differences (P<0.05) in the National Institutes of Health Stroke Scale scores at 24 hours, 72 hours, and 7 days, as well as in the change of the National Institutes of Health Stroke Scale scores from baseline to 24 hours. Additionally, there were no significant differences among the 4 groups in terms of 90-day mortality rate, symptomatic intracranial hemorrhage, early neurological deterioration, or severe adverse events. The effectiveness of NBO therapy was associated with oxygen administration duration. Among patients with acute ischemic stroke who underwent endovascular treatment, NBO therapy for 4 and 6 hours was found to be more effective. Larger-scale multicenter studies are needed to validate these findings. URL: https://www.clinicaltrials.gov; Unique identifier: NCT05404373.

Electroacupuncture Ameliorates Cerebral Ischemia-reperfusion Injury by Inhibiting Pyroptosis through the Sirtuin-1 Pathway

Abstract Objective: NOD-like receptor protein 3 (NLRP3)-mediated pyroptosis is pivotal in the pathological development of cerebral ischemia/reperfusion injury (CIRI). Although previous research has shown that electroacupuncture (EA) can alleviate CIRI through sirtuin-1 (SIRT1), the mechanism has not been well elucidated. Our study aimed to clarify whether the neuroprotective functions of EA are related to the reduction in NLRP3-mediated pyroptosis through the SIRT1 pathway. Materials and Methods: Rats received daily pretreatment with EA for 5 consecutive days before undergoing middle cerebral artery occlusion surgery. The Longa score was used to assess neurologic function. Infarct volume and morphological alterations were analyzed using 2,3,5-triphenyltetrazolium chloride and hematoxylin and eosin staining. In addition, neuronal pyroptosis was identified by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling/caspase-1 and neuronal nuclear antigen/caspase-1 immunofluorescence double staining. Levels of expression of pyroptosis markers were assessed by Western blotting and enzyme-linked immunosorbent assay. Results: EA improved deficits in neurologic function and minimized cerebral infarct volume. Mechanistically, a number of neuronal pyroptotic cells and protein levels of NLRP3, apoptosis-associated speck-like protein containing a CARD, and gasdermin D in the cerebral cortex were markedly reduced by EA treatment, and conversely, SIRT1 levels were increased. Notably, the specific SIRT1 inhibitor, EX527, reversed the effects of EA. Conclusions: EA potentially exerts a neuroprotective effect against CIRI through the SIRT1 pathway in NLRP3-mediated pyroptosis.

Apigenin protects against ischemic stroke by increasing DNA repair.

Oxidative stress is an important pathological process in ischemic stroke (IS). Apigenin (APG) is a natural product with favorable antioxidative effects, and some studies have already demonstrated the antioxidative mechanism of APG in the treatment of IS. However, the mechanism of APG on DNA damage and repair after IS is not clear. The aim of this study was to investigate the mechanism of APG on DNA repair after IS. Male Sprague-Dawley rats were used to establish a model of permanent middle cerebral artery occlusion (pMCAO) on one side, and were pre-treated with gavage of APG (30, 60, or 120mg/kg) for 7 days. One day after pMCAO, the brain tissues were collected. Cerebral infarct volume, brain water content, HE staining and antioxidant index were analyzed to evaluated the brain damage. Molecular Docking, molecular dynamics (MD) simulation, immunohistochemistry, and Western blot were used to explore the potential proteins related to DNA damage repair. APG has a low binding score with DNA repair-related proteins. APG treatment has improved the volume of cerebral infarction and neurological deficits, reduced brain edema, and decreased parthanatos and apoptosis by inhibiting PARP1/AIF pathway. In addition, APG improved the antioxidative capacity through reducing reactive oxygen species and malondialdehyde, and increasing glutathione and superoxide dismutase. Also, APG has reduced DNA damage- and cell death-related proteins such as PARP1, γH2A.X, 53BP1, AIF, cleaved caspase3, Cytochrome c, and increased DNA repair by BRCA1 and RAD51 through homologous recombination repair, and reduced non-homologous end link repair by KU70. APG can improve nerve damage after IS, and these protective effects were realized by reducing oxidative stress and DNA damage, and improving DNA repair.

A novel p55PIK signaling peptide inhibitor alleviates neuroinflammation via the STAT3/NF-kB signaling pathway in experimental stroke

BackgroundIschemic stroke remains the predominant contributor to mortality and disability globally. Microglia undergo rapid activation and initiate inflammatory cascade reactions by phenotypic polarization, participating in the regulation of inflammatory injury and tissue repair post-ischemic stroke. Regulating microglia-mediated neuroinflammation is a promising therapeutic strategy for ischemic stroke. Previously, we designed and synthesized a novel p55PIK inhibitor, TAT-N15 polypeptide, which presents inhibitive activity on NF-κB signaling-mediated inflammation in acute conjunctivitis and allergic rhinitis. The present study aimed to explore the therapeutic effect and mechanism of TAT-N15 on ischemia stroke. MethodsThe mouse model of transient cerebral ischemia was made using the intraluminal filament method. After being treated with daily intraperitoneal injections of TAT-N15 (10 mg/kg) for 7 d, the neurological outcomes and the cerebral infarction volume were evaluated. Histopathology of the ischemia cerebral hemisphere was observed by H&E and Nissl staining. Neuronal survival, astrogliosis, and co-labeling of CD86/Iba1 and CD206/Iba1 were detected by immunofluorescence. The cell apoptosis was estimated by TUNEL staining. The expression levels of apoptosis-associated proteins, proinflammatory cytokines, protein markers of M1 and M2 microglia, and the phosphorylation of NF-κB and STAT3 proteins in the ischemic penumbra were detected by Western blot. ResultsTAT-N15 treatment significantly decreased the infarct volume and alleviated neurological functional impairment, neuronal injury, and neuron apoptosis. Meanwhile, TAT-N15 treatment restrained the activation of microglia and astrocytes as well as the protein expression of proinflammatory cytokine in ischemic penumbra. Additionally, the administration of TAT-N15 treatment resulted in a significant reduction in the density of M1 phenotype microglia while concurrently increasing the density of M2 phenotype microglia within the ischemic penumbra. Finally, mechanical analysis unveiled that TAT-N15 exerted a substantial inhibitory effect on the protein expression of phosphorylated STAT3 and NF-κB. ConclusionTAT-N15 may inhibit neuroinflammation via regulating microglia activation and polarization through the STAT3/NF-κB pathway, which exhibits the neuroprotection effect in ischemic stroke.

Effect of electroacupuncture on proBDNF/mBDNF and synaptic plasticity in rats with learning and memory impairment after cerebral ischemia-reperfusion.

To observe the effect of electroacupuncture (EA) at "Baihui" (GV20) and "Shenting" (GV24) on the rats' behavior and the transforming precursor of brain-derived neurotrophic factor (proBDNF) into mature brain-derived neurotrophic factor (mBDNF) in the hippocampus of rats with learning and memory impairment induced by cerebral ischemia-reperfusion (IR), so as to explore its mechanisms underlying improvement of learning and memory ability. SD rats were randomly divided into blank, sham operation, model, and EA groups, with 6 rats in each group. The model of IR was established by occlusion of the middle cerebral artery. EA (1 Hz/20 Hz) was applied to GV24 and GV20 for 30 min, once daily for 14 days. The neurological function was evaluated according to the Zea Longa's score criteria 24 h after modeling and after intervention. Morris water maze test was used to detect the learning and memory function of the rats. TTC staining was used to evaluate the cerebral infarction volume on the affected side. The protein expression levels of proBDNF, mBDNF, tissue plasminogen activator (tPA), tyrosine kinase receptor B (TrkB) and p75 neurotrophin receptor (p75NTR) in hippocampal tissue were detected by Western blot. Compared with the sham operation group, the neurological function score, the percentage of cerebral infarction volume and the expression levels of proBDNF and p75NTR protein in hippocampus were increased (P<0.01), while the times of crossing the original platform and the total distance in the target quadrant, the expression levels of mBDNF, TrkB and tPA protein and the ratio of mBDNF/proBDNF were decreased (P<0.01, P<0.05) in the model group. Compared with the model group, the neurological function score, the percentage of cerebral infarction volume, and the expression levels of proBDNF and p75NTR protein in hippocampus were decreased (P<0.01, P<0.05), while the times of crossing the original platform, the total distance in the target quadrant, and the expression levels of mBDNF, TrkB and tPA protein and the ratio of mBDNF/proBDNF were increased (P<0.05, P<0.01) in the EA group. EA can alleviate learning and memory impairment in IR rats, which may be related to its function in up-regulating the expression of tPA protein and promoting the transformation of proBDNF to mBDNF, thus improving the synaptic plasticity.

Involvement of P2X7R-mediated microglia polarization and neuroinflammation in the response to electroacupuncture on post-stroke memory impairment

PurposePost-stroke cognitive impairment (PSCI) is a common complication of ischemic stroke episodes. Memory impairment is an important component of the poststroke cognitive syndrome. Microglial activation plays a critical role in stroke-induced neuroinflammation. Previous studies have reported that electroacupuncture (EA) provides neuroprotective effects by reducing the expression levels of the Purinergic receptor P2X ligand-gated ion channel 7 (P2X7) and inhibiting neuroinflammation in rat model of ischemic stroke. Further understanding of the role and connections between P2X7R and microglial activation in EA-induced anti-inflammatory can reveal novel targets for post-stroke memory impairment treatment. MethodsA Middle cerebral artery occlusion and reperfusion (MCAO/R) model was established. We used 2’(3’)-O-(4-benzoyl) benzoyl ATP (BzATP) as a P2X7R agonist. Following MCAO/R injury, the rats underwent EA therapy at the Baihui (DU20) and Shenting (DU24) acupoints for seven consecutive days. The Barnes maze test was used to evaluate memory function. Following intervention, a T2 weighted images (T2WI) scan was performed to identify changes in cerebral infarction volume in MCAO/R rats. The levels of Interleukin-1β (IL-1β), Interleukin-6 (IL-6) and Interleukin-4 (IL-4), Interleukin-10 (IL-10) in the peri-infarct hippocampal were examined by ELISA. Immunofluorescence was employed to evaluate Iba-1+ / P2X7R+, Iba-1+/ iNOS+ and Iba-1+/ Arg-1+ cell populations in the peri-infarct hippocampal DG area. The protein expression of P2X7R, Nuclear factor E2-related factor 2 (Nrf2), Recombinant nlr family, pyrin domain containing protein 3 (NLRP3), Inducible nitric oxide synthase (iNOS) and Arginase-1 (Arg-1) in the peri-infarct hippocampal were investigated using western blot assays. Besides, we also measured the levels of reactive oxygen species (ROS), superoxide dismutase (SOD) and malondialdehyde (MDA). ResultsWe found EA treatment reduced inflammation and oxidative stress, which is consistent with a decrease in P2X7R expression and improved learning and memory functions. In contrast, we found BzATP enhanced inflammation and oxidative stress. Moreover, our results showed EA treatment up-regulated Nrf2, down-regulated NLRP3, and promoted microglia M2 polarization. Finally, EA-mediated positive effects were reversed by intracerebroventricular injection of BzATP, which is consistent with an increase in P2X7R expression. ConclusionEA ameliorates memory impairment in a rat model of ischemic stroke by reducing inflammation and ROS through the inhibition of P2X7R expression. In turn, this mechanism regulates Nrf2 and NLRP3 expression, suggesting EA is beneficial for ischemic stroke treatment using P2X7R as target.

Salidroside promotes angiogenesis after cerebral ischemia in mice through Shh signaling pathway

AimsThe purpose of this study was to explore the impacts of salidroside on vascular regeneration, vascular structural changes and long-term neurological recuperation following cerebral ischemia and its possible mechanism. Main methodsFrom Day 1 to Day 28, young male mice with middle cerebral artery blockage received daily doses of salidroside and measured neurological deficits. On the 7th day after stroke, the volume of cerebral infarction was determined using TTC and HE staining. Microvascular density, astrocyte coverage, angiogenesis and the expression of the Shh signaling pathway were detected by IF, qRTPCR and WB at 7, 14 and 28 days after stroke. Changes in blood flow, blood vessel density and diameter from stroke to 28 days were measured by the LSCI and TPMI. Key findingsCompared with the dMACO group, the salidroside treatment group significantly promoted the recovery of neurological function. Salidroside was found to enhance cerebral blood flow perfusion and reduce the infarct on the 7th day after stroke. From the 7th to the 28th day after stroke, salidroside treatment boosted the expression of CD31, CD31+/BrdU+, and GFAP in the cortex around the infarction site. On the 14th day after stroke, salidroside significantly enhanced the width and density of blood vessels. Salidroside increased the expression of histones and genes in the Shh signaling pathway during treatment, and this effect was weakened by the Shh inhibitor Cyclopamine. SignificanceSalidroside can restore nerve function, improve cerebral blood flow, reduce cerebral infarction volume, increase microvessel density and promote angiogenesis via the Shh signaling pathway.

Angong Niuhuang Pill ameliorates cerebral ischemic injury in mice by selectively activating mitophagy

BackgroundAngong Niuhuang Pill (ANP) is a famous Chinese materia medica preparation prescribed for treating ischemic stroke. However, the protective mechanisms of ANP in acute ischemic stroke remain unclear and need to be explored. ObjectiveOur study aims to investigate the therapeutic effects of ANP on focal cerebral ischemia and explore the molecular mechanisms underlying its heat-clearing and detoxifying effects. MethodsThe permanent middle cerebral artery occlusion (pMCAO) model was established in C57BL/6 male mice, which were then treated with ANP (25 mg/kg, 100 mg/kg, or 400 mg/kg) or 80 mg/kg butylphthalide. To further verify the involvement of mitophagy in ANP function, mice were also treated with the autophagy inhibitor wortmannin or the mitophagy inhibitor mdivi-1 at ischemic onset. ResultsAcute administration with 100 mg/kg, or 400 mg/kg ANP significantly improved neurological behavior and decreased cerebral infarct volume, suggesting that ANP conferred neuroprotective effects dose-dependently. Further, western blot analysis showed that ANP treatment significantly decreased the protein levels of cytoplasmic cytochrome C and Bax, but elevated levels of mitochondrial cytochrome C and Bcl-2. TUNEL staining also indicated that ANP ameliorated cell apoptosis. ANP did not promote ischemia-induced lipidation of LC3, but significantly reduced the protein level of SQSTM1. Moreover, ANP further reduced mitochondrial contents and enhanced translocation of Parkin and SQSTM1 to the mitochondria. Importantly, the neuroprotective effects of ANP could be abolished by wortmannin and mdivi-1, respectively. ConclusionOur findings showed that ANP exerted protective effects in response to ischemic injury and enhanced selective mitophagy without increasing autophagic flux.

Coenzyme Q10 and exercise training reinstate middle cerebral artery occlusion-induced behavioral deficits and hippocampal long-term potentiation suppression in aging rats.

Patients experience post-stroke cognitive impairment during aging. To date, no specific treatment solution has been reported for this disorder. The purpose of this study was to evaluate the effects of exercise training and coenzyme Q10 supplementation on middle cerebral artery occlusion (MCAO) induced behavioral impairment, long-term potentiation inhibition and cerebral infarction size in aging rats. Fifty aging male rats underwent MCAO surgery and were randomly distributed in to the following groups: 1-Sham, 2- control, 3- Coenzyme Q10, 4- Exercise training and 5- Exercise training with Q10 supplementation (Ex + Q10). Aerobic training groups were allowed to run on a treadmill for 12 weeks. Q10 (50mg/kg) was administered intragastrically by gavage. Morris water maze, shuttle box and elevated plus maze tests were used to evaluate cognitive function. The population spike (PS) amplitude and slope of excitatory postsynaptic potentials (EPSP) in the dentate gyrus area were recorded as a result of perforant pathway electrical stimulation. Our study showed that Q10 and aerobic training alone ameliorate spatial memory in the acquisition phase, but have no effect on spatial memory in the retention phase. Q10 and exercise training synergistically promoted spatial memory in the retention phase. Q10 and exercise training separately and simultaneously mitigated cerebral ischemia-induced passive avoidance memory impairment in acquisition and retention phases. The EPSP did not differ between the groups, but exercise training and Q10 ameliorate the PS amplitude in hippocampal responses to perforant path stimulation. Exercising and Q10 simultaneously reduced the cerebral infarction volume. Collectively, the findings of the present study imply that 12 weeks of aerobic training and Q10 supplementation alone can simultaneously reverse cerebral ischemia induced neurobehavioral deficits via amelioration of synaptic plasticity and a reduction in cerebral infarction volume in senescent rats.

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.