Effect of Salvianolic Acid B Combined with Puerarin on Pyroptosis of SH-SY5Y Cells Injured by Oxygen-glucose Deprivation/Reoxygenation / 中国实验方剂学杂志

ObjectiveTo investigate the effect and mechanism of salvianolic acid B combined with puerarin in protecting the SH-SY5Y cells from the damage by oxygen-glucose deprivation/reoxygenation （OGD/R） based on pyroptosis. MethodSH-SY5Y cells were used to establish the model of OGD/R， and cells were classified into the control， OGD/R， 10 μmol·L-1 salvianolic acid B， 100 μmol·L-1 puerarin， 10 μmol·L-1 salvianolic acid B + 100 μmol·L-1 puerarin， and 10 μmol·L-1 NOD-like receptor protein 3 （NLRP3） inhibitor MCC950 groups. Except the control group， other groups were rapidly reoxygenated for 12 h after 6 h OGD for modeling. The cell survival rate was determined by the methyl thiazolyl tetrazolium （MTT） assay. An optical microscope was used to observe the cell morphology. A spectrophotometer was used to determine the content of lactic dehydrogenase （LDH） in culture supernatant. Cell damage was measured by Hoechst/PI staining. The mRNA levels of NLRP3， cysteinyl aspartate specific proteinase-1 （Caspase-1）， gasdermin D （GSDMD）， apoptosis-associated speck-like protein （ASC）， and interleukin-1β （IL-1β） were determined by real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）. The protein activation of Caspase-1 and NLRP3 was detected by immunofluorescence. Western blot was employed to determine the protein levels of IL-1β， ASC， NLRP3， Caspase-1， and cleaved Caspase-1. ResultCompared with the control group， the OGD/R group showed decreased cell survival rate （P<0.01）， damaged cell morphology， increased leakage rate of LDH （P<0.01）， up-regulated mRNA levels of NLRP3， Caspase-1， GSDMD， ASC， and IL-1β （P<0.01）， and up-regulated protein levels of IL-1β， ASC， NLRP3， Caspase-1， and cleaved Caspase-1 （P<0.01）. Compared with the OGD/R group， salvianolic acid B， puerarin， and salvianolic acid B combined with puerarin improved cell survival rate （P<0.01）， and the combined treatment group outperformed salvianolic acid B and puerarin used alone （P<0.01）. Salvianolic acid B combined with puerarin and MCC950 both improved cell morphology， reduced the leakage of LDH （P<0.01）， alleviated cell damage， and down-regulated the mRNA levels of NLRP3， Caspase-1， GSDMD， ASC， and IL-1β （P<0.05， P<0.01） and also the protein levels of IL-1β， ASC， NLRP3， Caspase-1， and cleaved Caspase-1 （P<0.05， P<0.01）. ConclusionThe results indicated that salvianolic acid B combined with puerarin can alleviate the OGD/R-induced damage of SH-SY5Y cells by inhibiting pyroptosis.

Study on the protective mechanism of Bawei chenxiang powder containing serum on H9c2 cells injured by oxygen-glucose deprivation / 中国药房

OBJECTIVE To study the protective mechanism of Bawei chenxiang powder containing serum on H9c2 cells injured by oxygen-glucose deprivation （OGD）. METHODS H9c2 cells were divided into blank group， model group and Bawei chenxiang powder low-dose， medium-dose and high-dose groups （the dose of drug containing serum 2.5， 8， 12 g/kg）. H9c2 cells were cultured in vitro to establish OGD model. After intervention with drug-containing serum， survival rate of cell was detected. The cell morphology was observed； the levels of lactate dehydrogenase （LDH）， creatine kinase （CK）， superoxide dismutase （SOD）， catalase （CAT）， respiratory chain complexⅠ （ComplexⅠ）， glutathione peroxidase （GSH-Px） and malondialdehyde （MDA） were detected. The contents of reactive oxygen species （ROS）， mitochondrial membrane potential and apoptosis were also detected. The expressions of oxidative stress-related proteins [Kelch ECH association protein 1 （Keap1）， nuclear factor erythroid 2- related factor 2 （Nrf2）， heme oxygenase 1 （HO-1）， NADH oxidoreductase coenzyme 10 （Ndufa10）， thioredoxin （Trx）] and apoptosis-related proteins [B-cell lymphoma 2 （Bcl-2）， Bcl-2 associated X protein （Bax）， Caspase-3 and cytochrome C （Cytc）] were detected. RESULTS Compared with blank group， the cell morphology of model group was damaged； the levels of LDH， CK and MDA were significantly increased （P＜0.01）， while the levels of CAT， ComplexⅠ， SOD and GSH-Px and mitochondrial membrane potential were significantly decreased （P＜0.01）. The content of intracellular ROS and apoptotic rate were significantly increased （P＜0.01）； the expressions of oxidative stress-related proteins （Keap1， Nrf2， HO-1， Ndufa10 and Trx） and pro- apoptosis proteins （Bax， Caspase-3 and Cytc） were significantly increased （P＜0.05）， while the expression of anti-apoptotic protein Bcl-2 was significantly decreased （P＜0.05）. After administration of Bawei chenxiang powder containing serum， the cell morphology improved， and most of the above indexes were significantly reversed （P＜0.05 or P＜0.01）.CONCLUSIONS Bawei chenxiang powder containing serum E-mail：345783110@qq.com has a good protective effect on H9c2 cells damaged by OGD，the mechanism of which is related to the reduction of oxidative damage and inhibition of cell apoptosis.

Mechanism of astragaloside Ⅳ in regulating autophagy of PC12 cells under oxygen-glucose deprivation by medicating Akt/mTOR/HIF-1α pathway / 中国中药杂志

This study explored the protective effect of astragaloside Ⅳ(AS-Ⅳ) on oxygen-glucose deprivation(OGD)-induced autophagic injury in PC12 cells and its underlying mechanism. An OGD-induced autophagic injury model in vitro was established in PC12 cells. The cells were divided into a normal group, an OGD group, low-, medium-, and high-dose AS-Ⅳ groups, and a positive drug dexmedetomidine(DEX) group. Cell viability was measured using the MTT assay. Transmission electron microscopy was used to observe autophagosomes and autolysosomes, and the MDC staining method was used to assess the fluorescence intensity of autophagosomes. Western blot was conducted to determine the relative expression levels of functional proteins LC3-Ⅱ/LC3-Ⅰ, Beclin1, p-Akt/Akt, p-mTOR/mTOR, and HIF-1α. Compared with the normal group, the OGD group exhibited a significant decrease in cell viability(P<0.01), an increase in autophagosomes(P<0.01), enhanced fluorescence intensity of autophagosomes(P<0.01), up-regulated Beclin1, LC3-Ⅱ/LC3-Ⅰ, and HIF-1α(P<0.05 or P<0.01), and down-regulated p-Akt/Akt and p-mTOR/mTOR(P<0.05 or P<0.01). Compared with the OGD group, the low-and medium-dose AS-Ⅳ groups and the DEX group showed a significant increase in cell viability(P<0.01), decreased autophagosomes(P<0.01), weakened fluorescence intensity of autophagosomes(P<0.01), down-regulated Beclin1, LC3-Ⅱ/LC3-Ⅰ, and HIF-1α(P<0.05 or P<0.01), and up-regulated p-Akt/Akt and p-mTOR/mTOR(P<0.01). AS-Ⅳ at low and medium doses exerted a protective effect against OGD-induced autophagic injury in PC12 cells by activating the Akt/mTOR pathway, subsequently influencing HIF-1α. The high-dose AS-Ⅳ group did not show a statistically significant difference compared with the OGD group. This study provides a certain target reference for the prevention and treatment of OGD-induced cellular autophagic injury by AS-Ⅳ and accumulates laboratory data for the secondary development of Astragali Radix and AS-Ⅳ.

Ultrashort wave alleviates oxygen -glucose deprivation/reoxygenation injury via up -regulation of SPCA1 expression in N2a cells / 中南大学学报(医学版)

OBJECTIVES@#Application of ultrashort wave (USW) to rats with cerebral ischemia and reperfusion injury could inhibit the decrease of expression of secretory pathway Ca2+-ATPase 1 (SPCA1), an important participant in Golgi stress, reduce the damage of Golgi apparatus and the apoptosis of neuronal cells, thereby alleviating cerebral ischemia-reperfusion injury. This study aims to investigate the effect of USW on oxygen-glucose deprivation/reperfusion (OGD/R) injury and the expression of SPCA1 at the cellular level.@*METHODS@#N2a cells were randomly divided into a control (Con) group, an OGD/R group, and an USW group. The cells in the Con group were cultured without exposure to OGD. The cells in the OGD/R group were treated with OGD/R. The cells in the USW group were treated with USW after OGD/R. Cell morphology was observed under the inverted phase-contrast optical microscope, cell activity was detected by cell counting kit-8 (CCK-8), apoptosis was detected by flow cytometry, and SPCA1 expression was detected by Western blotting.@*RESULTS@#Most of the cells in the Con group showed spindle shape with a clear outline and good adhesion. In the OGD/R group, cells were wrinkled, with blurred outline, poor adhesion, and lots of suspended dead cells appeared; compared with the OGD/R group, the cell morphology and adherence were improved, with clearer outlines and fewer dead cells in the USW group. Compared with the Con group, the OGD/R group showed decreased cell activity, increased apoptotic rate, and down-regulating SPCA1 expression with significant differences (all P<0.001); compared with the OGD/R group, the USW group showed increased cell activity, decreased apoptotic rate, and up-regulating SPCA1 expression with significant differences (P<0.01 or P<0.001).@*CONCLUSIONS@#USW alleviates the injury of cellular OGD/R, and its protective effect may be related to its up-regulation of SPCA1 expression.

Mechanism of Gastrodia elata active ingredient reducing oxygen-glucose deprivation/reoxygenation injury in rat neuron / 中国药房

OBJECTIVE To study the improvement effect and mechanism of Gastrodia elata active ingredient 3，4- dihydroxybenzaldehyde （3，4-DD） on oxygen-glucose deprivation/reoxygenation（OGD/R） injury in rat primary brain microvascular endothelial cells （BMECs）-rat adrenal chromaffin cells PC12 co-culture system. METHODS The co-culture model of BMECs and PC12 cells was replicated in the Transwell chamber， and divided into control group， model group， butylphthalide group （positive control group， 0.1 mmol/L） and 3，4-DD group （0.1 μmol/L）. OGD/R injury model of the co-culture system was induced in those groups except for the control group. After preventively intervention in BMECs with relevant medicine or culture medium for 24 h， cell transendothelial electronic resistance （TEER） value， lactate dehydrogenase （LDH） activity， brain-derived neurotrophic factor （BDNF） level and mRNA expressions of TrkB， Plc-γ， Map-2， GAP-43 in PC12 cells was detected. RESULTS Compared with the control group， TEER of the co-culture model， LDH activity and BDNF level of PC12 cells were decreased significantly in the model group （P＜0.01）， while mRNA expressions of TrkB， Plc-γ， Map-2 and GAP-43 in PC12 cells were increased significantly （P＜0.01）. Compared with the model group， TEER of the co-culture model， LDH activity， BDNF level， and the mRNA expressions of TrkB， Plc-γ， Map-2 and GAP-43 in PC12 cells were increased significantly in the 3，4-DD group and butylphthalide group （P＜0.05 or P＜0.01）. CONCLUSIONS 3，4-DD can relieve the damage of neuronal OGD/R by acting on BMECs， the mechanism of which may be associated with activating the BDNF/TrkB signaling pathway.

Naoluo Xintong Decoction activates caspase-1/Gasdermin D pathway to promote angiogenesis of rat brain microvascular endothelial cells after oxygen glucose deprivation/reperfusion injury / 南方医科大学学报

OBJECTIVE@#To investigate the effects of Naoluo Xintong Decoction (NLXTD) on pyroptosis and angiogenesis of brain microvascular endothelial cells (BMECs) and explore the possible mechanisms in rats with oxygen-glucose deprivation/ reperfusion (OGD/R).@*METHODS@#Rat BMECs with or without caspase-1 siRNA transfection were cultured in the presence of 10% medicated serum from NLXTD-treated rats (or blank serum) and exposed to OGD/R. CCK-8 assay, Transwell chamber assay, and tube formation assay were used to assess proliferation, migration, and tube-forming abilities of the cells. The activity of lactate dehydrogenase (LDH) in the culture supernatant was determined using a commercial assay kit, and the levels of inflammatory factors IL-1β and IL-18 were detected with ELISA. The cellular expressions of pro-caspase-1, caspase-1, NLRP3, Gasdermin D, and angiogenesis-related proteins VEGF and VEGFR2 were detected using Western blotting.@*RESULTS@#The BMECs showed obvious injuries after OGD/R exposure. Compared with the blank serum, the medicated serum significantly improved the cell viability, migration ability, and lumen-forming ability (P < 0.01) and lowered the levels of IL-1β and IL-18 and the LDH release (P < 0.01) of the cells with OGD/R exposure. Western blotting showed that in the BMECs exposed to OGD/R, the medicated serum strongly upregulated the expression of VEGF and VEGFR2 proteins (P < 0.01) and reduced the protein expressions of pro-caspase-1, caspase-1, NLRP3, and Gasdermin D (P < 0.01), and transfection of the cells with caspase-1 siRNA further promoted the expressions of VEGFR2 protein in the cells (P < 0.01).@*CONCLUSION@#NLXTD can improve the proliferation, migration, and tube- forming ability and promote angiogenesis of BMECs with OGD/R injury probably by inhibiting the caspase-1/Gasdermin D pathway in pyroptosis, alleviating cell injury, and upregulating the expressions of VEGF and VEGFR2.

The effects of a novel brain-derived peptide HIBDAP regulating the pyroptosis of oxygen-glucose deprived microglia / 中国新生儿科杂志

Objective:To study the role of a novel brain-derived peptide hypoxic-ischemic brain damage associated peptide (HIBDAP) in regulating pyroptosis of oxygen-glucose deprived (OGD) microglia.Methods:The sequence of HIBDAP was coupled with the sequence of cell-penetrating peptide transactivator of transcription (TAT) to form TAT-HIBDAP. Fluorescein isothiocyanate (FITC) labeled TAT-HIBDAP was added to microglia cells and observed under fluorescence microscope. Microglia cells were treated with different concentrations of TAT-HIBDAP (1, 5, 10, 20 μmol/L) and then OGD process. Cell pyroptosis was analyzed using lactate dehydrogenase (LDH) assay. The concentration of TAT-HIBDAP with the most prominent inhibiting effects was determined and selected for subsequent experiments. The pyroptosis morphology of the control group, the OGD group and the HIBDAP group (5 μmol/L TAT-HIBDAP+OGD) was observed using transmission electron microscope. The mRNA and protein expression of NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasomes were examined using real-time quantitative PCR and Western Blot analysis.Results:Fluorescence microscope showed FITC-labeled TAT-HIBDAP could successfully enter microglia cells. Compared with the OGD group, low concentrations of TAT-HIBDAP (1, 5, 10 μmol/L) could significantly reduce microglia pyroptosis and the concentration of 5 μmol/L showed the most prominent effects. Compared with the control group, OGD group showed typical pyroptosis morphology and HIBDAP group showed significantly improved morphology. The mRNA and protein expression of NLRP3 inflammasomes in the OGD group were significantly higher than the control group and also the HIBDAP group.Conclusions:The novel brain-derived peptide HIBDAP may reduce the expression of NLRP3 inflammasomes and inhibit the pyroptosis of OGD microglia.

Protective effect and mechanism of zonisamide on oxygen-glucose deprivation cell model of traumatic brain injury / 中华急诊医学杂志

Objective:To explore the protective effect of zonisamide (ZNS) on oxygen-glucose deprivation (OGD) cell model of traumatic brain injury (TBI), and its underlying mechanism.Methods:Human neuroblastoma cells (SH-SY5Y) were cultured in vitro and divided into the control group, OGD group, and drug administration group (OGD+ZNS group) according to the random number table method. The OGD method was used to establish a TBI cell model. After modeling, the cell activity, the release of lactate dehydrogenase (LDH), and β-galactosidase staining were detected to evaluate cell function and senescence. Additionally, mitochondrial morphology and potential membrane changes were observed using Mito Tracker Red and JC-1 mitochondrial membrane potential staining. ATP concentration was measured, and protein was extracted from SH-SY5Y cells and then subjected to Western blot analysis to detect endoplasmic reticulum stress-related markers, including glucose-regulated protein 78 (GRP78), C/EBP homologous protein (CHOP), protein disulfide isomerase (PDI), and β-actin.Results:The OGD group had a significantly lower cell survival rate compared to the control group ( P<0.01), while the OGD+ZNS group had a significant higher cell survival rate than the OGD group ( P<0.01). The LDH release rate was significantly higher in the OGD group than in the control group ( P<0.01), while the OGD+ZNS group had a significant lower LDH release rate compared to the OGD group ( P<0.01). Moreover, the cell staining results indicated that compared to the control and OGD+ZNS groups, the cells in the OGD group exhibited significant damage and senescence with darker staining while the mitochondrial staining results demonstrated a significant reduction in mitochondrial linear junctions and decreased mitochondrial activity in the OGD group compared to the control and OGD+ZNS groups. Compared to the control and OGD+ZNS groups, the OGD group exhibited a significant reduction in mitochondrial staining red fluorescence, a significant increase in green fluorescence, and a significant decrease in mitochondrial membrane potential. The OGD group demonstrated a significant decrease in ATP concentration compared to the control group ( P<0.01), whereas the OGD+ZNS group exhibited a significant higher ATP concentration compared to the OGD group ( P<0.01). Western blot analysis revealed significant upregulation of GRP78, CHOP, and PDI in the OGD group compared to the control group (all P<0.05), while in the OGD+ZNS group, the expression levels of these proteins were significantly downregulated compared to the OGD group (all P<0.05). Conclusions:Zonisamide can protect OGD TBI cell model by preserving mitochondrial activity and inhibiting endoplasmic reticulum stress.

Molecular mechanism of ligustilide attenuating OGD/R injury in PC12 cells by inhibiting ferroptosis / 中国中药杂志

The aim of this study is to explore the mechanism of ligustilide, the main active constituent of essential oils of traditional Chinese medicine Angelicae Sinensis Radix, on alleviating oxygen-glucose deprivation/reperfusion(OGD/R) injury in PC12 cells from the perspective of ferroptosis. OGD/R was induced in vitro, and 12 h after ligustilide addition during reperfusion, cell viability was detected by cell counting kit-8(CCK-8) assay. DCFH-DA staining was used to detect the level of intracellular reactive oxygen species(ROS). Western blot was employed to detect the expression of ferroptosis-related proteins, glutathione peroxidase 4(GPX4), transferrin receptor 1(TFR1), and solute carrier family 7 member 11(SLC7A11), and ferritinophagy-related proteins, nuclear receptor coactivator 4(NCOA4), ferritin heavy chain 1(FTH1), and microtubule-associated protein 1 light chain 3(LC3). The fluorescence intensity of LC3 protein was analyzed by immunofluorescence staining. The content of glutathione(GSH), malondialdehyde(MDA), and Fe was detected by chemiluminescent immunoassay. The effect of ligustilide on ferroptosis was observed by overexpression of NCOA4 gene. The results showed that ligustilide increased the viability of PC12 cells damaged by OGD/R, inhibited the release of ROS, reduced the content of Fe and MDA and the expression of TFR1, NCOA4, and LC3, and improved the content of GSH and the expression of GPX4, SLC7A11, and FTH1 compared with OGD/R group. After overexpression of the key protein NCOA4 in ferritinophagy, the inhibitory effect of ligustilide on ferroptosis was partially reversed, indicating that ligustilide may alleviate OGD/R injury of PC12 cells by blocking ferritinophagy and then inhibiting ferroptosis. The mechanism by which ligustilide reduced OGD/R injury in PC12 cells is that it suppressed the ferroptosis involved in ferritinophagy.

Effect of asiaticoside on OGD/R induced injury of H9C2 cardiomyocytes based on PI3K/Akt/Beclin-1 signaling pathway / 药学学报

In order to investigate the effects of asiaticoside (Ass) on H9C2 cardiomyocytes, the present study examined the potential intervention of Ass on the proliferation and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/Bcl-2 homology domain protein (Beclin-1) signaling pathway in H9C2 cardiomyocytes following oxygen and glucose deprivation/reperfusion (OGD/R) injury. H9C2 cardiomyocytes were selected as the research objects, and the activity of H9C2 was detected by cell counting kit-8 (CCK-8). H9C2 cells were divided into control group, OGD/R group, Ass low concentration group (10 μmol·L-1), Ass high concentration group (80 μmol·L-1) and Ass high concentration + chloroquine group (80 μmol·L-1 + 50 μmol·L-1). The control group was cultured under normal conditions, and the other groups were treated with oxygen and glucose deprivation for 4 h and reperfusion for 2 h. The activity and content of aspartic aminotransferase (AST), lactate dehydrogenase (LDH) and creatine kinase (CK) in the supernatant of H9C2 cardiomyocytes were detected by enzyme-linked immunosorbent assay. Autophagy staining assay kit with monodansylcadaverine (MDC) method to observe cellular autophagy; molecular docking technique to identify the molecular targets of Ass. Immunofluorescence was used to observe the effect of the drug on cell number. The expression levels of PI3K, Akt, selective autophagy adaptor protein (P62) and Beclin-1 were detected by Western blot. Compared with OGD/R group, Ass group had a protective effect from 10-80 μmol·L-1, and the activities and contents of AST, LDH and CK were decreased. The protein expression levels of PI3K, Akt, P62 and Beclin-1 were decreased. Compared with the administration group, the activities and contents of AST, LDH and CK in Ass high-concentration + chloroquine group were significantly decreased, and the protein expression levels of PI3K, Akt, Beclin-1 and P62 were significantly decreased. Immunofluorescence showed that the inhibitor group and each administration group had different degrees of protective effect compared with the model group. Asiaticoside can reduce the injury of H9C2 cardiomyocyte induced by OGD/R, reduce the content of AST, LDH and CK, reduce the expression level of P62 protein, and reduce autophagy, which may be closely related to the inhibition of PI3K/Akt/Beclin-1 signaling pathway activation.

Stigmasterol protects human brain microvessel endothelial cells against ischemia-reperfusion injury through suppressing EPHA2 phosphorylation / 中国天然药物

Stigmasterol is a plant sterol with anti-apoptotic, anti-oxidative and anti-inflammatory effect through multiple mechanisms. In this study, we further assessed whether it exerts protective effect on human brain microvessel endothelial cells (HBMECs) against ischemia-reperfusion injury and explored the underlying mechanisms. HBMECs were used to establish an in vitro oxygen and glucose deprivation/reperfusion (OGD/R) model, while a middle cerebral artery occlusion (MCAO) model of rats were constructed. The interaction between stigmasterol and EPHA2 was detected by surface plasmon resonance (SPR) and cellular thermal shift assay (CETSA). The results showed that 10 μmol·L-1 stigmasterol significantly protected cell viability, alleviated the loss of tight junction proteins and attenuated the blood-brain barrier (BBB) damage induced by OGD/R in thein vitro model. Subsequent molecular docking showed that stigmasterol might interact with EPHA2 at multiple sites, including T692, a critical gatekeep residue of this receptor. Exogenous ephrin-A1 (an EPHA2 ligand) exacerbated OGD/R-induced EPHA2 phosphorylation at S897, facilitated ZO-1/claudin-5 loss, and promoted BBB leakage in vitro, which were significantly attenuated after stigmasterol treatment. The rat MCAO model confirmed these protective effects in vivo. In summary, these findings suggest that stigmasterol protects HBMECs against ischemia-reperfusion injury by maintaining cell viability, reducing the loss of tight junction proteins, and attenuating the BBB damage. These protective effects are at least meditated by its interaction with EPHA2 and inhibitory effect on EPHA2 phosphorylation.

Repair effect and mechanism of neural cell adhesion molecule derived peptide P2 on nerve function injury in ischemic stroke rats / 中华行为医学与脑科学杂志

Objective:To clarify the neuroprotective effects of neural cell adhesion molecule (NCAM) derived peptide P2 on in vitro cultured neuron and ischemic stroke rat. Methods:Primary cortical neurons were extracted and cultured, and CCK-8 method was used to observe the protective effect of different concentrations of P2 on cortical neurons under oxygen-glucose deprivation (OGD) conditions.The levels of apoptosis-related proteins and extracellular signal regulated kinase 1/2 (Erk1/2) were observed by Western blot. Clean grade male SD rats were selected for animal experiments. The middle cerebral artery occlusion (MCAO) method was used to establish the rat model of cerebral ischemia/reperfusion injury. The rats with successful model were divided into sham operation group, MCAO group and MCAO+ P2 group according to the random number table, with 12 rats in each group. After operation, rats in MCAO+ P2 group were subcutaneously injected with 1 mg/kg P2 once a day until 14 days after operation, and rats in the other two groups were subcutaneously injected with 0.9% sodium chloride solution of the same volume.Beam-walking test was used to evaluate the motor function of rats.Immunofluorescence staining and Western blot were used to detect the in-situ apoptosis of neuronal cells and the expression of Erk1/2 in ischemic penumbra of rat brains, respectively. All statistical analyses were performed using SPSS 22.0.Repeated measurement ANOVA was used to evaluate the beam-walking experimental data, and one-way ANOVA were used to analyze other experimental data among multiple groups.Results:Compared with OGD group, 0.5, 1.0 and 2.0 μmol/L P2 improved the activity of neurons under OGD conditions, of which 1 μmol/L P2 had the best effect ((2.436±0.284), (1.551±0.410), P<0.05). Western blot showed that the protein levels of bax ((76.120±3.232)%, (88.965±5.208)%, P<0.05), cleaved caspase-3 ((76.736±4.306)%, (97.781±8.111)%, P<0.05) and cleaved caspase-9 ((88.833±6.581)%, (104.962±4.788)%, P<0.05) in 1 μmol/L P2 treated group were all lower than those in OGD group, while the protein levels of bcl-2 ((56.146±3.882)%, (43.170±6.945)%, P<0.05) and phosphorylated Erk1/2 ((73.583±8.557)%, (55. 219±4.615)%, P<0.05) in 1 μmol/L P2 treated group were both higher than those in OGD group. Compared with MCAO group, on the 14th day after P2 intervention, the slip ratio of hindlimb of the paralyzed hind limbs of rats was lower ((23.438±11.540)%, (41.733±13.631)%, P<0.05), the apoptosis rate of neurons around the focus was lower ((13.144±6.485)%, (26. 699±6. 402)%, P<0.05), and the level of phosphorylated Erk1/2 protein in the brain tissues around the infarct focus was higher ((74.062±7.458)%, (53.327±7.093)%, P<0.05). Conclusion:Low doses of neural cell adhesion molecule derived peptide P2 exert neuroprotective effects on OGD neurons and ischemic stroke rats. The underlying mechanism may be related to the activation of Erk.

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.

Protective Effect of Salviae Miltiorrhizae Radix et Rhizoma and Puerariae Lobatae Radix Extract on SH-SY5Y Cells Injured by Oxygen-glucose Deprivation/Reoxygenation / 中国实验方剂学杂志

ObjectiveTo explore the protective effect of Salviae Miltiorrhizae Radix et Rhizoma and Puerariae Lobatae Radix （SP） extract on oxygen-glucose deprivation/reoxygenation （OGD/R）-injured SH-SY5Y cells based on oxidative stress and apoptosis. MethodThe extracts of the two medicinal materials mixed in different ratios were prepared. Human neuroblastoma SH-SY5Y cells were cultured in vitro and the injury was induced by OGD/R. Cell counting kit-8 （CCK-8） assay was used to screen the optimal ratio of the two medicinals and then the extract was used for further experiment. SH-SY5Y cells were classified into normal control group， OGD/R group， and low-， medium-， and high-dose SP （2∶1） extract groups （10， 30， 100 mg·L-1， respectively）. Cells in the groups， except the normal control group， were rapidly reoxygenated for 12 h after 4 h OGD for modeling. Then cell viability was detected by CCK-8 and cell morphology was observed under the microscope. The release rate of lactate dehydrogenase （LDH）， superoxide dismutase （SOD） activity， and content of glutathione （GSH） and malondialdehyde （MDA） were determined by spectrophotometry. The level of reactive oxygen species （ROS） was detected with 2，7-dichlorodihydrofluorescein diacetate （DCFH-DA） and mitochondrial membrane potential with JC-1 assay. The nuclear morphology was observed based on Hoechst 33342 staining， and apoptosis was examined by flow cytometry combined with Annexin V-FITC/PI staining. ResultThe viability of the cells was highest in the presence of the extract of the two medicinals mixed at the ratio of 2∶1. Compared with normal control group， OGD/R group showed damaged cell morphology， high release rate of LDH and levels of ROS and MDA （P<0.01）， low SOD activity and GSH level （P<0.01）， low mitochondrial membrane potential， and high apoptosis rate （P<0.01）. Compared with OGD/R group， SP extract improved cell viability and cell morphology and reduce cell LDH release rate in a concentration-dependent manner （P<0.01）. In addition， SP extract at 30， 100 mg·L-1 reduced the level of intracellular ROS and increased SOD activity and GSH level （P<0.05， P<0.01）， and SP extract at 100 mg·L-1 decreased the content of MDA （P <0.05）. Moreover， SP extract increased mitochondrial membrane potential， and SP extract at 30， 100 mg·L-1 lowered the apoptosis rate （P<0.01）. ConclusionThe extract of Salvia miltiorrhiza Bunge and Radix Puerariae mixed at 2∶1 shows better protective effect on OGD/R-injured SH-SY5Y cells. The mechanism is the likelihood that it alleviates oxidative damage of cells and inhibits cell apoptosis.

Protective Effect of Salviae Miltiorrhizae Radix et Rhizoma and Puerariae Lobatae Radix Extract on SH-SY5Y Cells Injured by Oxygen-glucose Deprivation/Reoxygenation / 中国实验方剂学杂志

ObjectiveTo explore the protective effect of Salviae Miltiorrhizae Radix et Rhizoma and Puerariae Lobatae Radix （SP） extract on oxygen-glucose deprivation/reoxygenation （OGD/R）-injured SH-SY5Y cells based on oxidative stress and apoptosis. MethodThe extracts of the two medicinal materials mixed in different ratios were prepared. Human neuroblastoma SH-SY5Y cells were cultured in vitro and the injury was induced by OGD/R. Cell counting kit-8 （CCK-8） assay was used to screen the optimal ratio of the two medicinals and then the extract was used for further experiment. SH-SY5Y cells were classified into normal control group， OGD/R group， and low-， medium-， and high-dose SP （2∶1） extract groups （10， 30， 100 mg·L-1， respectively）. Cells in the groups， except the normal control group， were rapidly reoxygenated for 12 h after 4 h OGD for modeling. Then cell viability was detected by CCK-8 and cell morphology was observed under the microscope. The release rate of lactate dehydrogenase （LDH）， superoxide dismutase （SOD） activity， and content of glutathione （GSH） and malondialdehyde （MDA） were determined by spectrophotometry. The level of reactive oxygen species （ROS） was detected with 2，7-dichlorodihydrofluorescein diacetate （DCFH-DA） and mitochondrial membrane potential with JC-1 assay. The nuclear morphology was observed based on Hoechst 33342 staining， and apoptosis was examined by flow cytometry combined with Annexin V-FITC/PI staining. ResultThe viability of the cells was highest in the presence of the extract of the two medicinals mixed at the ratio of 2∶1. Compared with normal control group， OGD/R group showed damaged cell morphology， high release rate of LDH and levels of ROS and MDA （P<0.01）， low SOD activity and GSH level （P<0.01）， low mitochondrial membrane potential， and high apoptosis rate （P<0.01）. Compared with OGD/R group， SP extract improved cell viability and cell morphology and reduce cell LDH release rate in a concentration-dependent manner （P<0.01）. In addition， SP extract at 30， 100 mg·L-1 reduced the level of intracellular ROS and increased SOD activity and GSH level （P<0.05， P<0.01）， and SP extract at 100 mg·L-1 decreased the content of MDA （P <0.05）. Moreover， SP extract increased mitochondrial membrane potential， and SP extract at 30， 100 mg·L-1 lowered the apoptosis rate （P<0.01）. ConclusionThe extract of Salvia miltiorrhiza Bunge and Radix Puerariae mixed at 2∶1 shows better protective effect on OGD/R-injured SH-SY5Y cells. The mechanism is the likelihood that it alleviates oxidative damage of cells and inhibits cell apoptosis.

Role of PNPT1 in cardiomyocyte apoptosis induced by oxygen-glucose deprivation / 南方医科大学学报

OBJECTIVE@#To explore the effect of inhibiting polyribonucleotide nucleotidyl-transferase 1 (PNPT1) on oxygen-glucose deprivation (OGD)-induced apoptosis of mouse atrial myocytes.@*METHODS@#Cultured mouse atrial myocytes (HL-1 cells) with or without OGD were transfected with PNPT1-siRNA or a negative control siRNA (NC-siRNA group), and the cell survival rate was detected using CCK-8 assay. The expression levels of ACTB and TUBA mRNA were detected with qPCR, and the protein expression of PNPT1 was detected with Western blotting. The apoptosis rate of the treated cells was determined with flow cytometry, the mitochondrial membrane potential was detected using JC-1 kit, and the mitochondrial morphology was observed using transmission electron microscope.@*RESULTS@#With the extension of OGD time, the protein expression levels of PNPT1 increased progressively in the cytoplasm of HL-1 cells (P < 0.05). Transfection with PNPT1-siRNA significantly reduced PNPT1 expression in HL-1 cells (P < 0.05). Exposure to OGD significantly enhanced degradation of ACTB and TUBA mRNA (P < 0.05) and markedly increased the apoptosis rate of HL-1 cells (P < 0.05), and these changes were significantly inhibited by transfection with PNPT1-siRNA (P < 0.05), which obviously increased mitochondrial membrane potential and improved mitochondrial morphology of HL-1 cells exposed to OGD.@*CONCLUSION@#Inhibition of PNPT1 improves mitochondrial damage and reduces degradation of apoptotic-associated mRNAs to alleviate OGD-induced apoptosis of mouse atrial myocyte.

Effect of effective parts of Dracocephalum moldavica on the necroptosis of HBMECs after OGD/R injury / 药学学报

We investigated the ability of Dracocephalum moldavica (EPDM) flavonoids to protect human brain microvascular endothelial cells (HBMECs) from necroptosis induced by ischemia-reperfusion injury. To mimic the process of cerebral ischemia-reperfusion injury, a necroptosis model was established by treatment with the pan-cysteine aspartic acid protease (caspase) inhibitor Z-VAD-FMK combined with oxygen-glucose deprivation/re-oxygenation (OGD/R) injury using HBMECs. Cell proliferation and cytotoxicity (cell counting kit-8, CCK-8) was used to measure cell viability. A Hoechst33342/PI fluorescent double-staining method was exploited to determine the rate of cell necroptosis. A commercial kit was used to detect lactate dehydrogenase in the cell culture supernate. DCFH-DA probes, calcein AM and JC-1 probes were used to measure changes in ROS production, mitochondrial membrane permeability transformation pore (MPTP) opening and mitochondrial membrane potential (MMP), respectively. Enzyme-linked immunosorbent assay (ELISA) kits were chosen to detect the release of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6). Western blotting was used to detect necroptosis-related proteins. The results show that relative to control group, Z-VAD-FMK combined with OGD/R injury reduced cell viability, increased the necroptosis rate and the levels of LDH and ROS in HBMECs. The MPTP of the model group cells opened and the MMP reduced. TNF-α, IL-1β, and IL-6 levels were significantly elevated. Furthermore, the expression of receptor-interacting protein kinase 3 (RIP3) and mitochondrial phosphoglycerate mutase 5 (PGAM5) was significantly increased, accompanied by an increase of phosphorylated mixed-lineage kinase domain-like protein (p-MLKL)/MLKL. EPDM partially reversed the changes of the above-mentioned factors in HBMECs induced by Z-VAD-FMK plus OGD/R injury. These results indicate that EPDM may protect HBMECs from cerebral ischemia-reperfusion injury by inhibiting the RIP3/MLKL/PGAM5 pathway and MPTP opening to maintain mitochondrial function, thereby providing a scientific basis for the use of EPDM in the treatment of cerebral ischemia-related diseases.

Study of endoplasmic reticulum stress in human dental pulp cells induced by oxygen-glucose deprivation culture in vitro / 口腔疾病防治

Objective@#Oxygen-glucose deprivation (OGD) is used to mimic ischemia in vitro to observe whether endoplasmic reticulum (ER) stress is involved in human dental pulp cells (hDPCs) after OGD and to better understand the regulatory mechanism of hDPCs in ischemia.@*Methods@# hDPCs were cultured in glucose-free DMEM and hypoxia (volume fraction 2% O2) to establish an hDPCs OGD model in vitro, which mimics hDPCs ischemia in vitro. hDPCs were divided into a control group (normal culture) and an experimental group (OGD 0 h, 2 h, 4 h and 8 h groups). After pretreatment with OGD for 0, 2, 4 and 8 h, hDPC viability was measured by methylthiazol tetrazolium (MTT) assay. qRT-PCR was used to detect the mRNA expression of ER stress markers [splicing x-box binding protein1 (sXBP1), activating transcription Factor 4 (ATF4) and C/EBP homologous protein (chop)]. Western blot was used to detect the protein expression of ER stress markers [phosphorylated RNA-activated protein kinase-like ER-resident kinase (p-perk) and phosphorylated eukaryotic initiation factor-2α (p-eIF2α)]. @*Results@#Compared with OGD 0 h group, cell viability of hDPCs decreased when exposed to OGD treatment for 2 h, 4 h and 8 h. Compared with the control group, mRNA expressions of ER stress makers (sXBP1, ATF4 and chop) and the protein expressions of ER stress protein markers (p-perk andp-eIF2α) increased in OGD treatment cells after 4 h were higher in OGD cells. The differences were statistically significant (P<0.05).@*Conclusion@#The results indicate that ER stress response is involved in hDPCs in OGD treatment.

Total Saponins of Panax notoginseng Activate Akt/mTOR Pathway and Exhibit Neuroprotection in vitro and in vivo against Ischemic Damage / 中国结合医学杂志

OBJECTIVE@#To reveal the neuroprotective effect and the underlying mechanisms of a mixture of the main components of Panax notoginseng saponins (TSPN) on cerebral ischemia-reperfusion injury and oxygen-glucose deprivation/reoxygenation (OGD/R) of cultured cortical neurons.@*METHODS@#The neuroprotective effect of TSPN was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, flow cytometry and live/dead cell assays. The morphology of dendrites was detected by immunofluorescence. Middle cerebral artery occlusion (MCAO) was developed in rats as a model of cerebral ischemia-reperfusion. The neuroprotective effect of TSPN was evaluated by neurological scoring, tail suspension test, 2,3,5-triphenyltetrazolium chloride (TTC) and Nissl stainings. Western blot analysis, immunohistochemistry and immunofluorescence were used to measure the changes in the Akt/mammalian target of rapamycin (mTOR) signaling pathway.@*RESULTS@#MTT showed that TSPN (50, 25 and 12.5 µ g/mL) protected cortical neurons after OGD/R treatment (P<0.01 or P<0.05). Flow cytometry and live/dead cell assays indicated that 25 µ g/mL TSPN decreased neuronal apoptosis (P<0.05), and immunofluorescence showed that 25 µ g/mL TSPN restored the dendritic morphology of damaged neurons (P<0.05). Moreover, 12.5 µ g/mL TSPN downregulated the expression of Beclin-1, Cleaved-caspase 3 and LC3B-II/LC3B-I, and upregulated the levels of phosphorylated (p)-Akt and p-mTOR (P<0.01 or P<0.05). In the MCAO model, 50 µ g/mL TSPN improved defective neurological behavior and reduced infarct volume (P<0.05). Moreover, the expression of Beclin-1 and LC3B in cerebral ischemic penumbra was downregulated after 50 µ g/mL TSPN treatment, whereas the p-mTOR level was upregulated (P<0.05 or P<0.01).@*CONCLUSION@#TSPN promoted neuronal survival and protected dendrite integrity after OGD/R and had a potential therapeutic effect by alleviating neurological deficits and reversing neuronal loss. TSPN promoted p-mTOR and inhibited Beclin-1 to alleviate ischemic damage, which may be the mechanism that underlies the neuroprotective activity of TSPN.

Mitophagy mediated by ligustilide relieves OGD/R-induced injury in HT22 cells / 中国中药杂志

Mitochondrion, as the main energy-supply organelle, is the key target region that determines neuronal survival and death during ischemia. When an ischemic stroke occurs, timely removal of damaged mitochondria is very important for improving mitochondrial function and repairing nerve damage. This study investigated the effect of ligustilide(LIG), an active ingredient of Chinese medicine, on mitochondrial function and mitophagy based on the oxygen and glucose deprivation/reperfusion(OGD/R)-induced injury model in HT22 cells. By OGD/R-induced injury model was induced in vitro, HT22 cells were pre-treated with LIG for 3 h, and the cell viability was detected by the CCK-8 assay. Immunofluorescence and flow cytometry were used to detect indicators related to mitochondrial function, such as mitochondrial membrane potential, calcium overload, and reactive oxygen species(ROS). Western blot was used to detect the expression of dynamin-related protein 1(Drp1, mitochondrial fission protein) and cleaved caspase-3(apoptotic protein). Immunofluorescence was used to observe the co-localization of the translocase of outer mitochondrial membrane 20(TOMM20, mitochondrial marker) and lysosome-associated membrane protein 2(LAMP2, autophagy marker). The results showed that LIG increased the cell viability of HT22 cells as compared with the conditions in the model group. Furthermore, LIG also inhibited the ROS release, calcium overload, and the decrease in mitochondrial membrane potential in HT22 cells after OGD/R-induced injury, facilitated Drp1 expression, and promoted the co-localization of TOMM20 and LAMP2. The findings indicate that LIG can improve the mitochondrial function after OGD/R-induced injury and promote mitophagy. When mitophagy inhibitor mdivi-1 was administered, the expression of apoptotic protein increased, suggesting that the neuroprotective effect of LIG may be related to the promotion of mitophagy.