Role of curcumin-mediated inhibition of inflammation in alleviating brain ischemia-reperfusion synaptic injury / 公共卫生与预防医学

Objective To investigate the potential effect and mechanism of curcumin in inhibiting synaptic injury in the cortex of rats with cerebral ischemia-reperfusion. Methods Sprague-Dawley rats were divided into sham-operated group, model group, low-dose curcumin (50 mg/kg) group, and high-dose curcumin (100 mg/kg) group. A model of middle cerebral artery occlusion for 2 hours and reperfusion for 24 hours was constructed, and curcumin was administered. Based on the neurological function score, the effects of curcumin on cerebral infarct volume, synaptic ultrastructure changes, inflammatory cell infiltration, and the expression of NLRP3, Caspase-1, Synapsin1, and CAMKⅡ were observed after the end of the animal treatment. Results The neurological function scores were 0, 3.25±0.43, 2.50±0.50, and 1.50±0.50 for the sham-operated group, model group, low-dose curcumin group, and high-dose curcumin group, respectively. The percentage of cerebral infarct volume was 0, (38.89±2.21)%, (33.48±1.77)%, and (23.69±2.19)%, respectively. Compared with the sham operation group, the model group had severe synaptic ultrastructure damage, extensive inflammatory cell infiltration, significantly increased expression of Caspase-1 and NLRP3 (P < 0.5), and significantly decreased expression of Synapsin1 and CAMKⅡ (P < 0.5). Curcumin treatment significantly inhibited synaptic damage, reduced inflammatory cell infiltration, decreased the expression of Caspase-1 and NLRP3 (P < 0.5), and increased the expression of Synapsin1 and CAMKII (P < 0.5), when compared with the model group. Conclusion Ischemia-reperfusion-mediated synaptic injury in rat brain triggers an inflammatory response in cortical nerve cells, and curcumin alleviates synaptic damage and reduces brain injury by inhibiting inflammatory factor levels.

An improved 4-vessel intermittent occlusion method for establishing rat models of global cerebral ischemia-reperfusion injury / 南方医科大学学报

OBJECTIVE@#To improve the classical 4-vessel occlusion (4VO) model established by Pulsinelli and Brierley.@*METHODS@#Thirty-two male SD rats were randomized into sham operation group, I4VO-Con10 group, I4VO-Int10 group and I4VO-Int15 group. The sham surgery group underwent exposure of the bilateral vertebral arteries and carotid arteries without occlusion to block blood flow. The I4VO-Con10 group experienced continuous ischemia by occluding the bilateral vertebral arteries and carotid arteries for 10 minutes followed by reperfusion for 24 hours. The I4VO-Int10 and I4VO-Int15 groups were subjected to intermittent ischemia. The I4VO- Int10 group underwent 5 minutes of ischemia, followed by 5 minutes of reperfusion and another 5 minutes of ischemia, and then reperfusion for 24 hours. The I4VO-Int15 group experienced 5 minutes of ischemia followed by two cycles of 5 minutes of reperfusion and 5 minutes of ischemia, and then reperfusion for 24 hours. The regional cerebral blood flow (rCBF) was monitored with laser Doppler scanning, and survival of the rats was observed. HE staining was used to observe hippocampal pathologies to determine the optimal method for modeling. Another 48 rats were randomized into 6 groups, including a sham operation group and 5 model groups established using the optimal method. The 5 I4VO model groups were further divided based on the reperfusion time points (1, 3, 7, 14, and 28 days) into I4VO-D1, I4VO-D3, I4VO-D7, I4VO- D14, and I4VO- D28 groups. Body weight changes and survival of the rats were recorded. HE staining was used to observe morphological changes in the hippocampal, retinal and optic tract tissues. The Y-maze test and light/dark box test were used to evaluate cognitive and visual functions of the rats in I4VO-D28 group.@*RESULTS@#Occlusion for 5 min for 3 times at the interval of 5 min was the optimal method for 4VO modeling. In the latter 48 rats, the body weight was significantly lower than that of the sham-operated rats at 1, 3, 7, 14 and 28 days after modeling without significant difference in survival rate among the groups. The rats with intermittent vessel occlusion exhibited progressive deterioration of hippocampal neuronal injury and neuronal loss. Cognitive impairment was observed in the rats in I4VO-D28 group, but no obvious ischemic injury of the retina or the optic tract was detected.@*CONCLUSION@#The improved 4VO model can successfully mimic the main pathological processes of global cerebral ischemia-reperfusion injury without causing visual impairment in rats.

Protective Effect of Huazhuo Jiedu Huoxue Tongluo Prescription on Cerebral Ischemia-reperfusion Injury via Regulating Autophagy Based on JNK Signaling Pathway / 中国实验方剂学杂志

ObjectiveTo investigate the mechanism of Huazhuo Jiedu Huoxue Tongluo prescription in alleviating cerebral ischemia-reperfusion injury via regulating nerve cell autophagy based on c-Jun N-terminal kinase（JNK）signaling pathway . MethodSixty SD rats were randomly divided into 6 groups： sham group， middle cerebral artery occlusion/reperfusion （MCAO/R） group （model group）， Huazhuo Jiedu Huoxue Tongluo prescription group ［traditional Chinese medicine （TCM） group（25.0 g·kg-1）］， JNK inhibitor SP600125 （SP） group（5 mg·kg-1）， TCM+SP group and JNK agonist Anisomycin （Ani） group（15 mg·kg-1）. After 24 h of modeling， TCM group and TCM+SP group were given TCM decoction （ig） for 3 consecutive days， and the other groups were given equal volume of normal saline （ig）. Neurological deficit was evaluated by neurological function score and cerebral infarct volume was determined by 2，3，5-triphenyltetrazole chloride （TTC） staining. Hematoxylin-eosin （HE） staining and Nissl staining were used to observe the structural changes of brain tissue and the damage of neurons， respectively. Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay （TUNEL） was performed to detect cell apoptosis. The ultrastructure of autophagosomes was observed by transmission electron microscope. Western blot was employed to detect the protein expressions of microtubule-associated protein 1 light chain 3A/B （LC3A/B）， autophagy related 5 （Atg5）， the ortholog of yeast Atg6 （Beclin1）， p62， B-cell lymphoma 2 （Bcl-2）， JNK， phosphorylated （p）-JNK and c-Jun in brain tissue. The mRNA expressions of LC3A/B， Beclin1， p62， Atg5， Bcl-2， JNK and c-Jun were detected by Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）. ResultCompared with the sham group， the model group had elevated neurological deficit score （P<0.05）， enlarged cerebral infarct volume （P<0.05）and typical infarction manifestations formed in hippocampal region and its surrounding brain tissue. In addition， there were a large number of neuronal cell degeneration， necrosis， liquefaction， nucleus pyknosis and deep staining， and inflammatory cell infiltration in the cortex in the model group， and severe swelling of mitochondria， lysosomes， autophagosomes and autophagolysosomes were clearly seen under electron microscope. TUNEL positive cells were increased （P<0.05）， and cell apoptosis was severe. The nuclear membrane and nucleolus of neurons in brain tissue were blurred with discontinuous processes， and Nissl bodies in cytoplasm were stained light with reduced number. Western blot revealed that the model group had up-regulated protein expressions of LC3A/B， Beclin1， Atg5， JNK， p-JNK and c-Jun in brain tissue （P<0.05）， while down-regulated protein expressions of p62 and Bcl-2 （P<0.05）as compared with the sham group. Real-time PCR indicated that the mRNA expressions of LC3A/B， Beclin1， Atg5， JNK and c-Jun in the model group were higher （P<0.05） while the mRNA expressions of p62 and Bcl-2 were lower （P<0.05） than those in the sham group. Compared with the conditions in model group， the neurological deficit scores of TCM， SP and TCM+SP groups were lowered （P<0.05）， and the cerebral infarct volume was reduced （P<0.05）， with improved pathological status of brain tissue， especially in the TCM group. Furthermore， there were abundant and basically normal mitochondrial cristae， slightly dilated endoplasmic reticulum， slightly swollen golgi apparatus， slightly fused nuclear membrane， and few visible lysosomes， autophagosomes and autophagolysosomes. TUNEL positive cells were decreased （P<0.05）， displaying reduced apoptosis， especially in the TCM group. The nucleolus and nuclear membrane of neurons in brain tissue were discernible， and Nissl bodies in cytoplasm was reduced to a certain degree as compared with those in the model group. Western blot showed a decrease in the protein expressions of LC3A/B， Beclin1， Atg5， JNK， p-JNK and c-Jun in the TCM group ，the SP group，and the TCM+SP group（P<0.05），while an increase in the protein expressions of p62 in the TCM group and SP group（P<0.05），and an increase in the protein expressions of Bcl-2 in the TCM group and TCM+SP group. By Real-time PCR， the mRNA expressions of LC3A， LC3B， Beclin1， Atg5， JNK and c-Jun had a down-regulation（P<0.05） while the mRNA expression of p62 a up-regulation in the TCM group ，the SP group，and the TCM+SP group（P<0.05），and the mRNA expression of Bcl-2 a up-regulation in the TCM group and the TCM+SP group（P<0.05）.Scores of the Ani group were raised （P<0.05）， and infarct volume was increased significantly， with aggravated neuronal cell necrosis and obvious inflammatory infiltration. Moreover， there were neuronal nuclear membrane fusion with abnormal protrusion， increased heterochromatin aggregation in edge， severe mitochondrial swelling， endoplasmic reticulum expansion， increased lysosomes， increased intracytoplasmic vesicles， and visible autophagosomes and autophagolysosomes. TUNEL positive cells were increased （P<0.05）， representing severe apoptosis. The number of Nissl bodies dropped with light staining， and the nucleolus and nuclear membrane were blurred. Real-time PCR found that the mNRA expressions of Atg5， c-Jun， JNK were up-regulated （P<0.05），while Beclin1， p62， Bcl-2 were were down-regulated in the Ani group （P<0.05）. Compared with the TCM group and SP group，the protein expressions of LC3A/B， Beclin1， Atg5， JNK， p-JNK， c-Jun were decreased，and p62， Bcl-2 were increased in the Ani group（P<0.05）. Compared with the TCM group，the mRNA expressions of JNK mRNA had a down-regulation in the SP group and TCM+SP group，while LC3A， LC3B， Atg5， c-Jun， JNK had an up-regulation（P<0.05） and Bcl-2 had a down-regulation in the Ani group（P<0.05）. Compared with the SP group，the mRNA expressions of Atg5， c-Jun， JNK had an up-regulation（P<0.05）， and Beclin1， p62， Bcl-2 had a down-regulation in the Ani group（P<0.05）. ConclusionHuazhuo Jiedu Huoxue Tongluo prescription significantly up-regulates the protein and mRNA expressions of LC3A/B， Beclin1， Atg5， JNK， p-JNK and c-Jun， and down-regulates the protein and mRNA expressions of p62 and Bcl-2， suggesting that the prescription can inhibit autophagy through JNK signaling pathway to reduce ischemia/reperfusion injury in rats.

Mechanism of Chinese Medicine Saponins in Treatment of Cerebral Ischemia-reperfusion Based on Literature Analysis / 中国实验方剂学杂志

Cerebral ischemia-reperfusion is a serious cerebrovascular disease with high morbidity and mortality. In recent years， reperfusion therapy based on thrombolysis and thrombectomy has been the main treatment method for patients with ischemic stroke. Numerous studies have shown that Chinese medicine saponins can effectively interfere with cerebral ischemia-reperfusion in a multi-target and multi-way manner， which have great potential on the treatment and prevention of cerebral ischemia-reperfusion. Taking China National Knowledge Infrastructure （CNKI） literature database and Wanfang literature database as the analysis sources， this paper used SPSS statistics to summarize the number of papers on the treatment of cerebral ischemia-reperfusion with Chinese medicine saponins and CiteSpace to conduct cluster analysis on the high-frequency keywords of the research， thereby expounding the research hotspots and research status of Chinese medicine saponins in the treatment of cerebral ischemia-reperfusion. Based on literature analysis and summary of animal experiments on the treatment of cerebral ischemia-reperfusion with Chinese medicine saponins in the past two decades， Chinese medicine saponins exerted effects by anti-inflammation， inhibition of oxidative stress， immune regulation， protection of nerve cells， inhibition of thrombosis， promotion of thrombolysis， protection of mitochondria， blood-brain barrier repairing， and other ways. The specific mechanism， therapeutic effect， and signaling pathway of each Chinese medicine saponin have been summarized in this study， which provide a theoretical basis for the in-depth research， new drug development， and clinical application of Chinese medicine saponins for the treatment of cerebral ischemia- reperfusion.

Effect of Xiaoxuming Decoction on synaptic plasticity following acute cerebral ischemia-reperfusion in rats / 中国中药杂志

This study aims to explore the effect of Xiaoxuming Decoction on synaptic plasticity in rats with acute cerebral ischemia-reperfusion. A rat model of cerebral ischemia-reperfusion injury was established by middle cerebral artery occlusion(MCAO). Rats were randomly assigned into a sham group, a MCAO group, and a Xiaoxuming Decoction(60 g·kg~(-1)·d~(-1)) group. The Longa score was rated to assess the neurological function of rats with cerebral ischemia for 1.5 h and reperfusion for 24 h. The 2,3,5-triphenyltetrazolium chloride(TTC) staining and hematoxylin-eosin(HE) staining were employed to observe the cerebral infarction and the pathological changes of brain tissue after cerebral ischemia, respectively. Transmission electron microscopy was employed to detect the structural changes of neurons and synapses in the ischemic penumbra, and immunofluorescence, Western blot to determine the expression of synaptophysin(SYN), neuronal nuclei(NEUN), and postsynaptic density 95(PSD95) in the ischemic penumbra. The experimental results showed that the modeling increased the Longa score and led to cerebral infarction after 24 h of ischemia-reperfusion. Compared with the model group, Xiaoxuming Decoction intervention significantly decreased the Longa score and reduced the formation of cerebral infarction area. The modeling led to the shrinking and vacuolar changes of nuclei in the brain tissue, disordered cell arrangement, and severe cortical ischemia-reperfusion injury, while the pathological damage in the Xiaoxuming Decoction group was mild. The modeling blurred the synaptic boundaries and broadened the synaptic gap, while such changes were recovered in the Xiaoxuming Decoction group. The modeling decreased the fluorescence intensity of NEUN and SYN, while the intensity in Xiaoxuming Decoction group was significantly higher than that in the model group. The expression of SYN and PSD95 in the ischemic penumbra was down-regulated in the model group, while such down-regulation can be alleviated by Xiaoxuming Decoction. In summary, Xiaoxuming Decoction may improve the synaptic plasticity of ischemic penumbra during acute cerebral ischemia-reperfusion by up-regulating the expression of SYN and PSD95.

Quality control mechanism of mitochondria by 3,4-dihydroxybenzaldehyde through OGT-PINK1 pathway / 中国中药杂志

Based on the O-GlcNAc transferase(OGT)-PTEN-induced putative kinase 1(PINK1) pathway, the mechanism of 3,4-dihydroxybenzaldehyde(DBD) on mitochondrial quality control was investigated. Middle cerebral artery occlusion/reperfusion(MCAO/R) rats were established. SD rats were randomized into sham operation group(sham), model group(MCAO/R), DBD-L group(5 mg·kg~(-1)), and DBD-H group(10 mg·kg~(-1)). After 7 days of administration(ig), MCAO/R was induced in rats except the sham group with the suture method. Twenty-four h after reperfusion, the neurological function and the percentage of cerebral infarct area were measured. Based on hematoxylin and eosin(HE) staining and Nissl staining, the pathological damage of cerebral neurons was examined. Then the ultrastructure of mitochondria was observed under the electron microscope, and the co-localization of light chain-3(LC3), sequestosome-1(SQSTM1/P62), and Beclin1 was further detected by immunofluorescence staining. It has been reported that the quality of mitochondria can be ensured by inducing mitochondrial autophagy through the OGT-PINK1 pathway. Therefore, Western blot was employed to detect the expression of OGT, mitophagy-related proteins PINK1 and E3 ubiquitin ligase(Parkin), and mitochondrial kinetic proteins dynamin-like protein 1(Drp1) and optic atrophy 1(Opa1). The results showed that MCAO/R group had neurological dysfunction, large cerebral infarct area(P<0.01), damaged morphological structure of neurons, decreased number of Nissl bodies, mitochondrial swelling, disappearance of mitochondrial cristae, decrease of cells with LC3 and Beclin1, rise of cells with P62(P<0.01), inhibited expression of OGT, PINK1, and Parkin, up-regulated expression of Drp1, and down-regulated expression of Opa1 compared with the sham group(P<0.01). However, DBD improved the behavioral deficits and mitochondrial health of MCAO/R rats, as manifested by the improved morphology and structure of neurons and mitochondria and the increased Nissl bodies. Moreover, DBD increased cells with LC3 and Beclin1 and decreased cells with P62(P<0.01). In addition, DBD promoted the expression of OGT, PINK1, Parkin, and Opa1 and inhibited the expression of Drp1, enhancing mitophagy(P<0.05, P<0.01). In conclusion, DBD can trigger PINK1/Parkin-mediated brain mitophagy through the OGT-PINK1 pathway, which plays a positive role in maintaining the health of the mitochondrial network. This may be a mitochondrial therapeutic mechanism to promote nerve cell survival and improve cerebral ischemia/reperfusion injury.

Chrysin alleviates cerebral ischemia-reperfusion injury by inhibiting ferroptosis in rats / 中国中药杂志

The purpose of this study is to investigate whether chrysin reduces cerebral ischemia-reperfusion injury(CIRI) by inhi-biting ferroptosis in rats. Male SD rats were randomly divided into a sham group, a model group, high-, medium-, and low-dose chrysin groups(200, 100, and 50 mg·kg~(-1)), and a positive drug group(Ginaton, 21.6 mg·kg~(-1)). The CIRI model was induced in rats by transient middle cerebral artery occlusion(tMCAO). The indexes were evaluated and the samples were taken 24 h after the operation. The neurological deficit score was used to detect neurological function. The 2,3,5-triphenyl tetrazolium chloride(TTC) staining was used to detect the cerebral infarction area. Hematoxylin-eosin(HE) staining and Nissl staining were used to observe the morphological structure of brain tissues. Prussian blue staining was used to observe the iron accumulation in the brain. Total iron, lipid pero-xide, and malondialdehyde in serum and brain tissues were detected by biochemical reagents. Real-time quantitative polymerase chain reaction(RT-qPCR), immunohistochemistry, and Western blot were used to detect mRNA and protein expression of solute carrier fa-mily 7 member 11(SLC7A11), transferrin receptor 1(TFR1), glutathione peroxidase 4(GPX4), acyl-CoA synthetase long chain family member 4(ACSL4), and prostaglandin-endoperoxide synthase 2(PTGS2) in brain tissues. Compared with the model group, the groups with drug intervention showed restored neurological function, decreased cerebral infarction rate, and alleviated pathological changes. The low-dose chrysin group was selected as the optimal dosing group. Compared with the model group, the chrysin groups showed reduced content of total iron, lipid peroxide, and malondialdehyde in brain tissues and serum, increased mRNA and protein expression levels of SLC7A11 and GPX4, and decreased mRNA and protein expression levels of TFR1, PTGS2, and ACSL4. Chrysin may regulate iron metabolism via regulating the related targets of ferroptosis and inhibit neuronal ferroptosis induced by CIRI.

Effective constituents of essential oil from Gleditsiae Fructus Abnormalis and anti-cerebral ischemia/reperfusion injury mechanism: based on GC-MS, network pharmacology, and experimental verification / 中国中药杂志

Based on GC-MS and network pharmacology, the active constituents, potential targets, and mechanism of essential oil from Gleditsiae Fructus Abnormalis(EOGFA) against cerebral ischemia/reperfusion(I/R) injury were explored, and the effective constituents were verified by experiment. To be specific, GC-MS was used identify the constituents of the volatile oil. Secondly, the targets of the constituents and disease were predicted by network pharmacology, and the drug-constituent-target network was constructed, followed by Gene Ontology(GO) term enrichment and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment of the core targets. Molecular docking was performed to investigate the binding affinity between the active constituents and the targets. Finally, SD rats were used for experimental verification. The I/R injury model was established, and the neurological behavior score, infarct volume, and pathological morphology of brain tissue were measured in each group. The content of interleukin-1β(IL-1β), interleukin-6(IL-6), and tumor necrosis factor-alpha(TNF-α) was determined by enzyme-linked immunosorbent assay(ELISA), and the protein expression of vascular endothelial growth factor(VEGF) by Western blot. A total of 22 active constituents and 17 core targets were screened out. The core targets were involved in 56 GO terms and the major KEGG pathways of TNF signaling pathway, VEGF signaling pathway, and sphingolipid signaling pathway. Molecular docking showed that the active constituents had high affinity to the targets. The results of animal experiment suggested that EOGFA can alleviate the neurological impairment, decrease the cerebral infarct volume and the content of IL-1β, IL-6 and TNF-α, and down-regulate the expression of VEGF. The experiment verified the part results of network pharmacology. This study reflects the multi-component, multi-target, and multi-pathway characteristics of EOGFA. The mechanism of its active constituents is related to TNF and VEGF pathways, which provides a new direction for in-depth research on and secondary development of Gleditsiae Fructus Abnormalis.

Mechanism of total flavonoids of Rhododendra simsii in alleviating ischemic brain injury / 中国中药杂志

This study explores the effect of total flavonoids of Rhododendra simsii(TFR) on middle cerebral artery occlusion(MCAO)-induced cerebral injury in rats and oxygen-glucose deprivation/reoxygenation(OGD/R) injury in PC12 cells and the underlying mechanism. The MCAO method was used to induce focal ischemic cerebral injury in rats. Male SD rats were randomized into sham group, model group, and TFR group. After MCAO, TFR(60 mg·kg~(-1)) was administered for 3 days. The content of tumor necrosis factor-α(TNF-α), interleukin-1(IL-1), and interleukin-6(IL-6) in serum was detected by enzyme-linked immunosorbent assay(ELISA). The pathological changes of brain tissue and cerebral infarction were observed based on hematoxylin and eosin(HE) staining and 2,3,5-triphenyltetrazolium chloride(TTC) staining. RT-qPCR and Western blot were used to detect the mRNA and protein levels of calcium release-activated calcium channel modulator 1(ORAI1), stromal interaction molecule 1(STIM1), stromal intera-ction molecule 2(STIM2), protein kinase B(PKB), and cysteinyl aspartate specific proteinase 3(caspase-3) in brain tissues. The OGD/R method was employed to induce injury in PC12 cells. Cells were randomized into the normal group, model group, gene silencing group, TFR(30 μg·mL~(-1)) group, and TFR(30 μg·mL~(-1))+gene overexpression plasmid group. Intracellular Ca~(2+) concentration and apoptosis rate of PC12 cells were measured by laser scanning confocal microscopy and flow cytometry. The effect of STIM-ORAI-regulated store-operated calcium entry(SOCE) pathway on TFR was explored based on gene silencing and gene overexpression techniques. The results showed that TFR significantly alleviated the histopathological damage of brains in MCAO rats after 3 days of admini-stration, reduced the contents of TNF-α, IL-1, and IL-6 in the serum, down-regulated the expression of ORAI1, STIM1, STIM2, and caspase-3 genes, and up-regulated the expression of PKB gene in brain tissues of MCAO rats. TFR significantly decreased OGD/R induced Ca~(2+) overload and apoptosis in PC12 cells. However, it induced TFR-like effect by ORAI1, STIM1 and STIM2 genes silencing. However, overexpression of these genes significantly blocked the effect of TFR in reducing Ca~(2+) overload and apoptosis in PC12 cells. In summary, in the early stage of focal cerebral ischemia-reperfusion injury and OGD/R-induced injury in PC12 cells TFR attenuates ischemic brain injury by inhibiting the STIM-ORAI-regulated SOCE pathway and reducing Ca~(2+) overload and inflammatory factor expression, and apoptosis.

Effect of Tongdu Tiaoshen electroacupuncture pretreatment on PPARγ-mediated pyroptosis of cerebral cortex in rats with cerebral ischemia reperfusion injury / 中国针灸

OBJECTIVE@#To observe the effect of Tongdu Tiaoshen (promoting the circulation of the governor vessel and regulating the spirit) electroacupuncture (EA) pretreatment on pyroptosis mediated by peroxisome proliferators-activated receptor γ (PPARγ) of the cerebral cortex in rats with cerebral ischemia reperfusion injury (CIRI) and explore the potential mechanism of EA for the prevention and treatment of CIRI.@*METHODS@#A total of 110 clean-grade male SD rats were randomly divided into a sham-operation group, a model group, an EA group, an EA + inhibitor group and an agonist group, 22 rats in each group. In the EA group, before modeling, EA was applied to "Baihui" (GV 20), "Fengfu" (GV 16) and "Dazhui" (GV 14), with disperse-dense wave, 2 Hz/5 Hz in frequency, 1 to 2 mA in intensity, lasting 20 min; once a day, consecutively for 7 days. On the base of the intervention as the EA group, on the day 7, the intraperitoneal injection with the PPARγ inhibitor, GW9662 (10 mg/kg) was delivered in the EA + inhibitor group. In the agonist group, on the day 7, the PPARγ agonist, pioglitazone hydrochloride (10 mg/kg) was injected intraperitoneally. At the end of intervention, except the sham-operation group, the modified thread embolization method was adopted to establish the right CIRI model in the rats of the other groups. Using the score of the modified neurological severity score (mNSS), the neurological defect condition of rats was evaluated. TTC staining was adopted to detect the relative cerebral infarction volume of rat, TUNEL staining was used to detect apoptosis of cerebral cortical nerve cells and the transmission electron microscope was used to observe pyroptosis of cerebral cortical neural cells. The positive expression of PPARγ and nucleotide-binding to oligomerization domain-like receptor protein 3 (NLRP3) in the cerebral cortex was detected with the immunofluorescence staining. The protein expression of PPARγ, NLRP3, cysteinyl aspartate specific protease-1 (caspase-1), gasdermin D (GSDMD) and GSDMD-N terminal (GSDMD-N) in the cerebral cortex was detected with Western blot. Using the quantitative real-time fluorescence-PCR, the mRNA expression of PPARγ, NLRP3, caspase-1 and GSDMD of the cerebral cortex was detected. The contents of interleukin (IL)-1β and IL-18 in the cerebral cortex of rats were determined by ELISA.@*RESULTS@#Compared with the sham-operation group, the mNSS, the relative cerebral infarction volume and the TUNEL positive cells rate were increased (P<0.01), pyroptosis was severe, the protein and mRNA expression levels of PPARγ, NLRP3, caspase-1 and GSDMD were elevated (P<0.01); and the protein expression of GSDMD-N and contents of IL-1β and IL-18 were increased (P<0.01) in the model group. When compared with the model group, the mNSS, the relative cerebral infarction volume and the TUNEL positive cells rate were decreased (P<0.01), pyroptosis was alleviated, the protein and mRNA expression levels of PPARγ were increased (P<0.01), the protein and mRNA expression levels of NLRP3, caspase-1 and GSDMD were decreased (P<0.01), the protein expression of GSDMD-N was reduced (P<0.01); and the contents of IL-1β and IL-18 were lower (P<0.01) in the EA group and the agonist group; while, in the EA + inhibitor group, the protein expression of PPARγ was increased (P<0.01), the protein and mRNA expression levels of NLRP3 and GSDMD were decreased (P<0.01, P<0.05), the mRNA expression of caspase-1 was reduced (P<0.01); and the contents of IL-1β and IL-18 were lower (P<0.01). When compared with the EA + inhibitor group, the mNSS, the relative cerebral infarction volume and the TUNEL positive cells rate were decreased (P<0.05, P<0.01), pyroptosis was alleviated, the protein and mRNA expression levels of PPARγ were increased (P<0.01), the protein and mRNA expression levels of NLRP3, caspase-1 and GSDMD were decreased (P<0.01), the protein expression of GSDMD-N was reduced (P<0.01); and the contents of IL-1β and IL-18 were declined (P<0.01) in the EA group. Compared with the agonist group, in the EA group, the relative cerebral infarction volume and the TUNEL positive cells rate were increased (P<0.05, P<0.01), the mRNA expression of PPARγ was decreased (P<0.01) and the protein expression of GSDMD-N was elevated (P<0.05); and the contents of IL-1β and IL-18 were higher (P<0.01).@*CONCLUSION@#Tongdu Tiaoshen EA pretreatment can attenuate the neurological impairment in the rats with CIRI, and the underlying mechanism is related to the up-regulation of PPARγ inducing the inhibition of NLRP3 in the cerebral cortex of rats so that pyroptosis is affected.

Effects of electroacupuncture on NLRP3/Caspase-1/GSDMD axis and neurological function in rats with cerebral ischemic reperfusion / 中国针灸

OBJECTIVE@#To investigate the neuroprotective effect of electroacupuncture (EA) at "Quchi" (LI 11) and "Zusanli" (ST 36) in the rats with cerebral ischemic reperfusion and the potential mechanism of microglia pyroptosis.@*METHODS@#Sixty SD rats were randomly divided into a sham-operation group, a model group and an EA group, with 20 rats in each group. The Zea Longa method was employed to establish the rat model of the middle cerebral artery occlusion and reperfusion (MACO/R) in the left brain. In the EA group, since the 2nd day of modeling, EA was given at "Quchi" (LI 11) and "Zusanli" (ST 36) of right side with disperse-dense wave, 4 Hz/20 Hz in frequency and 0.2 mA in current intensity, 30 min each time, once a day for lasting 7 consecutive days. The reduction rate of cerebral blood flow was measured with laser Doppler flowmetry during operation. The neurological function of rats was observed using Zea Longa neurobehavioral score. The cerebral infarction volume was detected by TTC staining method. The microglia positive expression in the ischemic side of the cortex was detected with the immunofluorescence method. Under transmission electron microscope, the ultrastructure of cell in the ischemic cortex was observed. The mRNA expression levels of nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3), apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), cysteinyl aspartate specific proteinase-1 (Caspase-1) and gasdermin D (GSDMD) in the ischemic cortex were detected using real-time PCR.@*RESULTS@#Compared with the sham-operation group, in the model group, the reduction rate of cerebral blood flow was increased during operation (P<0.001); Zea Longa neurobehavional score and the percentage of cerebral infarction volume were increased (P<0.001), the numbers of M1-type microglia marked by CD68+ and M2-type microglia marked by TMEM119+ were elevated in the ischemic cortex (P<0.001), the mRNA expression of NLRP3, ASC, Caspase-1 and GSDMD was increased (P<0.001, P<0.01); the cytomembrane structure was destroyed, with more cell membrane pores formed in the ischemic cortex. Compared with the model group, after intervention, Zea Longa neurobehavioral score and the percentage of cerebral infarction volume were reduced (P<0.05), the number of M1-type microglia marked by CD68+ was reduced (P<0.05) and the number of M2-type microglia marked by TMEM119+ was increased (P<0.05); and the mRNA expression of NLRP3, ASC, Caspase-1 and GSDMD was decreased (P<0.01, P<0.05) in the EA group. Even though the cytomembrane structure was incomplete, there were less membrane pores presented in the ischemic cortex in the EA group after intervention.@*CONCLUSION@#The intervention with EA attenuates the neurological dysfunction and reduces the volume of cerebral infarction in the rats with cerebral ischemic reperfusion. The underlying mechanism is related to the inhibition of microglia pyroptosis through modulating NLRP3/Caspase-1/GSDMD axis.

Research Progress on Protective Effect and Mechanism of Salidroside on Cerebral Ischemia Injury： A Review / 中国实验方剂学杂志

Ischemic stroke is caused by a variety of factors caused by intracerebral artery stenosis or obstruction， can lead to cerebral ischemia， hypoxia， neuronal necrosis and neurological dysfunction and other pathological injuries， with high morbidity， high disability rate， high mortality characteristics. Cerebral ischemia-reperfusion injury is the main secondary injury， which can lead to permanent disability or even death in severe cases. With the development of traditional Chinese medicine（TCM） modernization， the extraction and application of active components of TCM have been paid more and more attention. Salidroside， as the main active component of Rhodirosea， a rare Chinese medicinal herb， has been proved to fight cerebral ischemia injury by inhibiting cell apoptosis， anti-oxidative stress， reducing inflammatory response， protecting blood-brain barrier， regulating autophagy， promoting nerve remodeling and synaptic regeneration in preclinical trials. However， due to its multi-pathway， multi-pathway and multi-target action characteristics， the specific mechanism of salidroside to improve cerebral ischemia injury has not been fully elucidated. By reviewing relevant literature in the past decade， the author reviewed the mechanism of action of salidroside in the treatment of ischemic brain injury， and summarized the recent progress of its pharmacokinetic studies and safety evaluation， in order to provide theoretical basis and new research ideas for the development and clinical application of the active ingredients of traditional Chinese medicine.

Protective effect of Sox11 gene against cerebral ischemia reperfusion injury and its mechanism in mice / 中国生物制品学杂志

@#ObjectiveTo explore the protective effect of Sox11 gene on cerebral ischemia reperfusion injury(CIRI)in mice and its mechanism,so as to provide a new target for the treatment of CIRI.MethodsThe mouse middle cerebral artery occlusion(MCAO)model and Neuro2A cell oxygen glucose deprivation reperfusion(OGDR)model were established and detected for the temporal and spatial distribution of Sox11 in the models by real-time quantitative PCR,Western blot,immunohistochemistry(IHC)and immunohistofluorescence(IHF).The altered expression of some crucial genes in the pathway of apoptosis and inflammation in OGDR model after the disruption of Sox11 expression was detected by Western blot.ResultsThe expression level of Sox11 mRNA and protein increased significantly in both MCAO and Neuro2A OGDR models(P = 0.000 1 ～ 0.038 8);After CIRI,Sox11 expression was elevated in the hippocampal dentate gyrus(DG)region of mice;After interfering with the expression of Sox11 in OGDR model,the expression of apoptosis-related protein Cleaved Caspase 3 significantly increased,while the expression of anti-apoptosis protein Bcl-2 significantly decreased,and the expression of phosphorylated NF-κB(p-NF-κB)protein related to inflammatory reaction also up-regulated significantly.Conclusion Sox11gene had a protective effect against CIRI in mice,and was involved in the regulation of apoptosis and inflammation pathways after CIRI.

Effects of pramipexole combined with levodopa on cognitive and mitochondrial function of rats after global cerebral ischemia-reperfusion injury / 中国康复理论与实践

ObjectiveTo investigate the effects of dopamine receptor agonist pramipexole and levodopa on emotion and cognition, and mitochondrial membrane potential of rats after global cerebral ischemia-reperfusion injury. MethodsA total of 80 male Sprague-Dawley rats were divided into sham group (n = 20), model group (n = 20), pramipexole group (n = 20) and combined group (n = 20). The latter three groups were used to prepare the model of global cerebral ischemia-reperfusion injury with Pulsinelli's four-vessel occlusion. The pramipexole group was intraperitoneally injected pramipexole 0.5 mg/kg once a day, while the combined group was injected levodopa 50 mg/kg and pramipexole 0.5 mg/kg, for 14 days. Five rats in each group were tested with open field test three, seven and 14 days after modeling; five were tested with Y-maze test seven and 14 days after modeling; five were detected mitochondrial membrane potential three, seven and 14 days after modeling; and five were observed under Nissl's staining14 days after modeling. ResultsCompared with the model group, the number of entries into the central zone (P < 0.05), total distance travelled (P < 0.05) and average velocity (P < 0.05) in the open field test increased in the pramipexole and combined groups seven and 14 days after modeling, duration spent in the central zone increased in the pramipexole and combined groups seven days after modeling (P < 0.05); the rate of spontaneous alternation of Y-maze test increased in the pramipexole and combined groups 14 days after modeling (P < 0.05); mitochondrial membrane potential in hippocampus increased in the pramipexole and combined groups seven and 14 days after modeling (P < 0.05), and it was less in the pramipexole group than in the combined group 14 days after modeling (P < 0.05); and the number of surviving neurons in the hippocampal CA1 increased in the pramipexole and combined groups 14 days after modeling (P < 0.05). ConclusionPramipexole may improve emotion and cognition of rats after global cerebral ischemia-reperfusion injury, and it may be helpful for restoring mitochondrial membrane potential as combining with levodopa.

Buyang Huanwutang Alleviates Inflammatory Injury After Cerebral Ischemia-reperfusion in Rats via Activating Adiponectin Pathway / 中国实验方剂学杂志

ObjectiveTo investigate the effects of Buyang Huanwutang （BYWHT） on reducing inflammatory injury and improving neurological function after cerebral ischemia-reperfusion in rats via activating the adiponectin （APN） pathway. MethodMale SD rats were randomized into sham， model， BYHWT （16 g·kg-1， twice a day）， and BYHWT + APN inhibitor （GW9662） groups. In the sham group， blood vessels were isolated. The rat model of middle cerebral artery occlusion （MCAO） was established. The rats in the BYHWT+GW9662 group was treated with subcutaneous injection of GW9662 at 4 m·kg-1 30 min before MCAO surgery and BYHWT at 16 g·kg-1 by gavage after MCAO surgery， once in the morning and once in the evening. The immunofluorescence （IF） assay was employed to observe the expression of adiponectin receptor 1 （AdipoR1） and the colocalization of AdipoR1 with neuronal nuclei （NeuN） and ionized calcium binding adaptor molecule 1 （Iba1） in the brain. Enzyme-linked immunosorbent assay （ELISA） was employed to detect the expression of APN in the serum and brain. The balance beam test was carried out to examine the balance ability， and the grasping test to assess the recovery of limb strength. The immunofluorescence assay was used to detect the expression of myeloperoxidase （MPO）. Western blot was employed to determine the expression of tumor necrosis factor-alpha （TNF-α）， interleukin （IL）-1β， IL-6， and IL-10 and in the brain. ResultCompared with the sham group， the modeling promoted the expression of AdipoR1 （P<0.01）， lowered the APN levels in the serum and brain （P<0.05， P<0.01）， increased the score in the balance beam test （P<0.01）， and decreased the grasping strength of forepaw （P<0.01）， which were accompanied with increased MPO， TNF-α， IL-1β， and IL-6 levels （P<0.01） and decreased IL-10 level （P<0.01）. Compared with the model group， BYHWT promoted the expression of AdipoR1 （P<0.01）， elevated APN levels in the serum and brain （P<0.05， P<0.01）， and increased the grasping strength of forepaw （P<0.01）， which were accompanied with lowered MPO， TNF-α， IL-1β， and IL-6 levels （P<0.01） and elevated IL-10 level （P<0.01）. All the above effects were partially blocked by GW9662. ConclusionBYHWT can reduce inflammatory injury and improve neurological function in the rat model of cerebral ischemia-reperfusion by activating the APN pathway.

Mechanism of gypenoside ⅩⅦ against cerebral ischemia/reperfusion injury based on nuclear factor erythroid 2-related factor 2/antioxidant responsive element signaling pathway / 中华危重病急救医学

Objective:To explore the mechanism of gypenoside ⅩⅦ against cerebral ischemia/reperfusion (I/R) through nuclear factor erythroid 2-related factor 2/antioxidant responsive element (Nrf2/ARE) signaling pathway.Methods:Forty SPF Sprague Dawley (SD) rats were randomly divided into sham operated group, I/R model group, 25, 50 and 100 mg/kg gypenoside ⅩⅦ groups ( n = 8). Gypenoside ⅩⅦ groups were administered 25, 50 or 100 mg/kg (0.01 mL/g) gypenoside ⅩⅦ by intragastric administration for 14 days; the other two groups received the same dose of saline. Rat cerebral I/R model was established by modified line bolt method; rats in the sham operated group underwent the same procedure without producing substantial embolization. After 24 hours of reperfusion, the neurological deficit scores of the rats in each group were assessed. Rat abdominal aortic whole blood was collected and the serum reactive oxygen species (ROS), heme oxygenase-1 (HO-1), γ-glutamylcysteine synthase (γ-GCS), superoxide dismutase (SOD), quinone NADH oxidoreductase 1 (NQO1), and malondialdehyde (MDA) were detected. Then whole brain tissue was harvested and penumbra tissue was isolated from cerebral cortex, the general condition of rat brain tissue and the volume of cerebral infarction were evaluated, the histopathological changes in the brain were observed under light microscopy, the mRNA expressions of Nrf2 and Keap1 were measured by real-time fluorescent quantitative polymerase chain reaction (RT-qPCR), the protein expressions of Nrf2 and Keap1 were determined by Western blotting. Results:After 24 hours of reperfusion, compared with the sham operated group, the score of neurological deficit and infarct volume were significantly increased, the NQO1, SOD and γ-GCS levels in serum were significantly decreased, MDA, HO-1 and ROS levels in serum were significantly increased, the Nrf2 and Keap1 mRNA and protein expressions in the ischemic penumbra were significantly increased in rats from I/R model group. Compared with the I/R model group, the neurological deficit scores (1.50±0.53, 1.37±0.52 vs. 2.75±0.46) and brain infarct volume [(19.8±5.1)%, (21.4±6.4)% vs. (42.3±5.8)%] were significantly reduced, serum NQO1, SOD, HO-1 and γ-GCS were significantly increased [NQO1 (ng/L): 186.05±10.38, 220.75±16.22 vs. 131.36±5.95, SOD (kU/L): 63.23±5.30, 72.70±8.62 vs. 36.75±6.55, HO-1 (ng/L): 60.57±7.93, 60.35±4.72 vs. 42.72±4.95, γ-GCS (kU/L): 8.81±0.53, 8.72±0.69 vs. 6.80±0.56], serum MDA and ROS levels were significantly reduced [MDA (μmol/L): 5.94±0.66, 5.61±0.53 vs. 10.88±1.34, ROS (kU/L): 69.11±4.23, 67.12±4.52 vs. 104.43±7.54], the mRNA and protein expressions of Nrf2 and Keap1 in the ischemic penumbra were significantly increased in rats from 50 mg/kg and 100 mg/kg gypenoside ⅩⅦ groups [Nrf2 mRNA (2 -△△Ct): 1.90±0.13, 2.13±0.18 vs. 1.48±0.11, Keap1 mRNA (2 -△△Ct): 1.78±0.11, 1.85±0.10 vs. 1.43±0.10, Nrf2/β-actin: 0.73±0.04, 0.79±0.03 vs. 0.60±0.03, Keap1/β-actin: 0.71±0.01, 0.76±0.03 vs. 0.61±0.01], all the comparative differences were statistically significant (all P < 0.01); 25 mg/kg gypenoside ⅩⅦ had no significant effect. Conclusion:Gypenoside ⅩⅦ (50 mg/kg and 100 mg/kg) may play a role in anti-cerebral I/R injury by regulating NQO1, SOD, HO-1, γ-GCS, ROS and MDA through Nrf2/ARE signaling pathway.

Soybean isoflavones alleviate cerebral ischemia/reperfusion injury in rats by inhibiting ferroptosis and inflammatory cascade reaction / 南方医科大学学报

OBJECTIVE@#To explore the mechanism that mediates the effect of soybean isoflavones (SI) against cerebral ischemia/reperfusion (I/R) injury in light of the regulation of regional cerebral blood flow (rCBF), ferroptosis, inflammatory response and blood-brain barrier (BBB) permeability.@*METHODS@#A total of 120 male SD rats were equally randomized into sham-operated group (Sham group), cerebral I/R injury group and SI pretreatment group (SI group). Focal cerebral I/R injury was induced in the latter two groups using a modified monofilament occlusion technique, and the intraoperative changes of real-time cerebral cortex blood flow were monitored using a laser Doppler flowmeter (LDF). The postoperative changes of cerebral pathological morphology and the ultrastructure of the neurons and the BBB were observed with optical and transmission electron microscopy. The neurological deficits of the rats was assessed, and the severities of cerebral infarction, brain edema and BBB disruption were quantified. The contents of Fe2+, GSH, MDA and MPO in the ischemic penumbra were determined with spectrophotometric tests. Serum levels of TNF-α and IL-1βwere analyzed using ELISA, and the expressions of GPX4, MMP-9 and occludin around the lesion were detected with Western blotting and immunohistochemistry.@*RESULTS@#The rCBF was sharply reduced in the rats in I/R group and SI group after successful insertion of the monofilament. Compared with those in Sham group, the rats in I/R group showed significantly increased neurological deficit scores, cerebral infarction volume, brain water content and Evans blue permeability (P < 0.01), decreased Fe2+ level, increased MDA level, decreased GSH content and GPX4 expression (P < 0.01), increased MPO content and serum levels of TNF-α and IL-1β (P < 0.01), increased MMP-9 expression and lowered occludin expression (P < 0.01). All these changes were significantly ameliorated in rats pretreated with IS prior to I/R injury (P < 0.05 or 0.01).@*CONCLUSION@#SI preconditioning reduces cerebral I/R injury in rats possibly by improving rCBF, inhibiting ferroptosis and inflammatory response and protecting the BBB.

Forsythiaside B inhibits cerebral ischemia/reperfusion-induced oxidative stress injury in mice via the AMPK/DAF-16/FOXO3 pathway / 南方医科大学学报

OBJECTIVE@#To study the protective effect of forsythiaside B (FB) against cerebral oxidative stress injury induced by cerebral ischemia/reperfusion (I/R) in mice and explore the underlying mechanism.@*METHODS@#Ninety C57BL/6 mice were randomized into sham-operated group, middle cerebral artery occlusion (MCAO) model group, and low-, medium and highdose (10, 20, and 40 mg/kg, respectively) FB groups. The expression levels of MDA, ROS, PCO, 8-OHdG, SOD, GSTα4, CAT and GPx in the brain tissue of the mice were detected using commercial kits, and those of AMPK, P-AMPK, DAF-16, FOXO3 and P-FOXO3 were detected with Western blotting. Compound C (CC), an AMPK inhibitor, was used to verify the role of the AMPK pathway in mediating the therapeutic effect of FB. In another 36 C57BL/6 mice randomized into 4 sham-operated group, MCAO model group, FB (40 mg/kg) treatment group, FB+CC (10 mg/kg) treatment group, TTC staining was used to examine the volume of cerebral infarcts, and the levels of ROS and SOD in the brain were detected; the changes in the protein expressions of AMPK, P-AMPK, DAF-16, FOXO3 and P-FOXO3 in the brain tissue were detected using Western blotting.@*RESULTS@#In mice with cerebral IR injury, treatment with FB significantly reduced the levels of ROS, MDA, PCO and 8-OHdG, increased the activities of antioxidant enzymes SOD, GSTα4, CAT and GPx, and enhanced phosphorylation of AMPK and FOXO3 and DAF-16 protein expression in the brain tissue (P < 0.01). Compared with FB treatment alone, the combined treatment with FB and CC significantly reduced phosphorylation of AMPK and FOXO3, lowered expression of DAF-16 and SOD activity, and increased cerebral infarction volume and ROS level in the brain tissue of the mice (P < 0.01).@*CONCLUSION@#FB inhibits oxidative stress injury caused by cerebral I/R in mice possibly by enhancing AMPK phosphorylation, promoting the downstream DAF-16 protein expression and FOXO3 phosphorylation, increasing the expression of antioxidant enzymes, and reducing ROS level in the brain tissue.

Research progress of S-nitrosoglutathione reductase inhibitors in the regulation of cerebral injury after cardiac arrest-cardiopulmonary resuscitation / 中华危重病急救医学

The cerebral ischemia-reperfusion injury (CIRI) after the cardiac arrest (CA)-cardiopulmonary resuscitation (CPR) was a complex pathophysiology process. Nitric oxide (NO) is a small molecule that mediates cell signal transduction in vivo and plays an important role in the regulation of brain function during ischemia/reperfusion (I/R). S-nitrosoglutathione reductase (GSNOR) inhibitor can regulate the synthesis and release of NO in vivo and has a protective effect on CIRI. Therefore, early administration of GSNOR to CA-CPR patients could be the main treatment method to improve the prognosis of those patients. A large number of studies have been done to improve the prognosis of CA-CPR in recent years. In order to provide reference for further research on the treatment and brain protection of CIRI after CA-CPR, the article reviewed the main mechanisms of brain injury after CA-CPR, the protective effect and mechanism of NO on cerebral I/R injury, the production and regulation of NO, in vivo, and the protective effect of GSNOR inhibitors on CIRI, especially the research progress of GSNOR inhibitors.

Effect of M1 microglia-derived exosomal microRNA-20a-5p on neuronal injury after oxygen-glucose deprivation and restoration injury / 中华危重病急救医学

Objective:To investigate the effect of M1 microglia-derived exosomes (M1-exo) on neuronal injury after oxygen-glucose deprivation and restoration, and to explore its mechanism.Methods:The mouse microglia BV2 cells grown in logarithmic growth phase were added with 100 μg/L liposolysaccharide (LPS) and 20 μg/L interferon-γ (IFN-γ) to induce the polarization of microglia into M1 phenotype. M1 microglia were identified by Western blotting, quantitative real-time polymerase chain reaction (qPCR) and immunofluorescence. The supernatant of M1 microglia was collected, and exosomes were extracted by ExoQuick-TC TM kit. The morphology of exosomes were observed by transmission electron microscope and nanoparticle tracking analysis (NTA), and the expression of characteristic proteins CD9 and CD63 of exosomes were detected by Western blotting. The well-growing mouse neuroblastoma N2a cells were divided into six groups: the cells in group C were conventionally-cultured; and the cells in group O were subjected to oxygen-glucose deprivation for 3 hours followed by restoration of oxygen-glucose supply 24 hours to establish the model of oxygen-glucose deprivation and restoration injury; and the N2a cells in group E were co-cultured with M1-exo 24 hours after oxygen-glucose deprivation 3 hours; NC group, M group and I group constructed negative control, overexpression and knockdown of microRNA-20a-5p (miR-20a-5p) M1-exo, respectively. The succession of transfection was detected by qPCR and N2a cells in group NC, group M and group I were co-cultured with such transfected M1-exo for 24 hours after oxygen-glucose deprivation 3 hours. Cell viability were detected by cell counting kit-8 (CCK-8) assay, cell apoptosis were detected by flow cytometry, and the expression of miR-20a-5p were detected by qPCR. Results:Compared with M0 microglia, the fluorescence intensity and mRNA and protein expressions of CD32 and inducible nitric oxide synthase (iNOS), specific markers of M1 microglia, were increased [CD32 (fluorescence intensity): 36.919±1.541 vs. 3.533±0.351, CD32 mRNA (2 -ΔΔCt): 4.887±0.031 vs. 1.003±0.012, CD32/β-actin: 2.663±0.219 vs. 1.000±0.028; iNOS (fluorescence intensity): 29.513±1.197 vs. 7.933±0.378, iNOS mRNA (2 -ΔΔCt): 4.829±0.177 vs. 1.000±0.016, iNOS/β-actin: 1.991±0.035 vs. 1.000±0.045; all P < 0.01], indicating M1 microglia were successfully activated. Under electron microscopy, M1-exo had round or oval vesicular bodies with obvious membranous structures, with diameters ranging from 100 nm. Western blotting showed that the exosomes expressed specific CD63 and CD9 proteins. Compared with group C, the cell viability was decreased, the apoptosis rate and the expression of miR-20a-5p were significantly increased in group O [cell viability ( A value): 0.540±0.032 vs. 1.001±0.014, apoptosis rate: (19.857±0.910)% vs. (13.508±0.460)%, miR-20a-5p (2 -ΔΔCt): 5.508±0.291 vs. 1.033±0.101, all P < 0.01]. Compared with O group, cell viability was decreased, apoptosis rate and the expression of miR-20a-5p were increased in group E [cell viability ( A value): 0.412±0.029 vs. 0.540±0.032, apoptosis rate: (31.802±0.647)% vs. (19.857±0.910)%, miR-20a-5p (2 -ΔΔCt): 8.912±0.183 vs. 5.508±0.291, all P < 0.01], indicating that M1 microglia-derived exosomes further aggravated the damage of N2a cells after oxygen-glucose deprivation and restoration. Compared with group E, cell viability was decreased, apoptosis rate and the expression of miR-20a-5p were increased in group M [cell viability ( A value): 0.311±0.028 vs. 0.412±0.029, apoptosis rate: (36.343±0.761)% vs. (31.802±0.647)%, miR-20a-5p (2 -ΔΔCt): 32.348±0.348 vs. 8.912±0.183, all P < 0.01]; and the cell viability was increased, apoptosis rate and the expression of miR-20a-5p were decreased in group I [cell viability ( A value): 0.498±0.017 vs. 0.412±0.029, apoptosis rate: (26.437±0.793)% vs. (31.802±0.647)%, miR-20a-5p (2 -ΔΔCt): 6.875±0.219 vs. 8.912±0.183, all P < 0.01]. There was no significant difference in cell viability, apoptosis rate and the expression of miR-20a-5p between group E and group NC. Conclusion:M1 microglia-derived exosomes aggravate the injury of neurons after oxygen and glucose deprivation and reoxygenation, which may be related to miR-20a-5p carried by M1-exo.