Shuxuetong injection protects cerebral microvascular endothelial cells against oxygen-glucose deprivation reperfusion

Shuxuetong injection composed of leech(Hirudo nipponica Whitman) and earthworm(Pheretima aspergillum) has been used for the clinical treatment of acute stroke for many years in China. However, the precise neuroprotective mechanism of Shuxuetong injection remains poorly understood. Here, cerebral microvascular endothelial cells(bEnd.3) were incubated in glucose-free Dulbecco's modified Eagle's medium containing 95% N_2/5% CO_2 for 6 hours, followed by high-glucose medium containing 95% O_2 and 5% CO_2 for 18 hours to establish an oxygen-glucose deprivation/reperfusion model. This in vitro cell model was administered Shuxuetong injection at 1/32, 1/64, and 1/128 concentrations(diluted 32-, 64-, and 128-times). Cell Counting Kit-8 assay was used to evaluate cell viability. A fluorescence method was used to measure lactate dehydrogenase, and a fluorescence microplate reader used to detect intracellular reactive oxygen species. A fluorescent probe was also used to measure mitochondrial superoxide production. A cell resistance meter was used to measure transepithelial resistance and examine integrity of monolayer cells. The fluorescein isothiocyanate-dextran test was performed to examine blood-brain barrier permeability. Real-time reverse transcription polymerase chain reaction was performed to analyze mRNA expression levels of tumor necrosis factor alpha, interleukin-1β, interleukin-6, and inducible nitric oxide synthase. Western blot assay was performed to analyze expression of caspase-3, intercellular adhesion molecule 1, vascular cell adhesion molecule 1, occludin, vascular endothelial growth factor, cleaved caspase-3, B-cell lymphoma 2, phosphorylated extracellular signal-regulated protein kinase, extracellular signal-regulated protein kinase, nuclear factor-κB p65, I kappa B alpha, phosphorylated I kappa B alpha, I kappa B kinase, phosphorylated I kappa B kinase, claudin-5, and zonula occludens-1. Our results show that Shuxuetong injection increases bEnd.3 cell viability and B-cell lymphoma 2 expression, reduces cleaved caspase-3 expression, inhibits production of reactive oxygen species and mitochondrial superoxide, suppresses expression of tumor necrosis factor alpha, interleukin-1β, interleukin-6, inducible nitric oxide synthase mRNA, intercellular adhesion molecule-1, and vascular cell adhesion molecule-1, markedly increases transepithelial resistance, decreases blood-brain barrier permeability, upregulates claudin-5, occludin, and zonula occludens-1 expression, reduces nuclear factor-κB p65 and vascular endothelial growth factor expression, and reduces I kappa B alpha, extracellular signal-regulated protein kinase 1/2, and I kappa B kinase phosphorylation levels. Overall, these findings suggest that Shuxuetong injection has protective effects on brain microvascular endothelial cells after oxygen-glucose deprivation/reperfusion. Moreover, its protective effect is associated with reduction of mitochondrial superoxide production, inhibition of the inflammatory response, and inhibition of vascular endothelial growth factor, extracellular signal-regulated protein kinase 1/2, and the nuclear factor-κB p65 signaling pathway.

Silencing Huwe1 reduces apoptosis of cortical neurons exposed to oxygen-glucose deprivation and reperfusion

HECT, UBA and WWE domain-containing 1(Huwe1), an E3 ubiquitin ligase involved in the ubiquitin-proteasome system, is widely expressed in brain tissue. Huwe1 is involved in the turnover of numerous substrates, including p53, Mcl-1, Cdc6 and N-myc, thereby playing a critical role in apoptosis and neurogenesis. However, the role of Huwe1 in brain ischemia and reperfusion injury remains unclear. Therefore, in this study, we investigated the role of Huwe1 in an in vitro model of ischemia and reperfusion injury. At 3 days in vitro, primary cortical neurons were transduced with a control or shRNA-Huwe1 lentiviral vector to silence expression of Huwe1. At 7 days in vitro, the cells were exposed to oxygen-glucose deprivation for 3 hours and reperfusion for 24 hours. To examine the role of the c-Jun N-terminal kinase(JNK)/p38 pathway, cortical neurons were pretreated with a JNK inhibitor(SP600125) or a p38 MAPK inhibitor(SB203508) for 30 minutes at 7 days in vitro, followed by ischemia and reperfusion. Neuronal apoptosis was assessed by TUNEL assay. Protein expression levels of JNK and p38 MAPK and of apoptosis-related proteins(p53, Gadd45 a, cleaved caspase-3, Bax and Bcl-2) were measured by western blot assay. Immunofluorescence labeling for cleaved caspase-3 was performed. We observed a significant increase in neuronal apoptosis and Huwe1 expression after ischemia and reperfusion. Treatment with the shRNA-Huwe1 lentiviral vector markedly decreased Huwe1 levels, and significantly decreased the number of TUNEL-positive cells after ischemia and reperfusion. The silencing vector also downregulated the pro-apoptotic proteins Bax and cleaved caspase-3, and upregulated the anti-apoptotic proteins Gadd45 a and Bcl-2. Silencing Huwe1 also significantly reduced p-JNK levels and increased p-p38 levels. Our findings show that downregulating Huwe1 affects the JNK and p38 MAPK signaling pathways as well as the expression of apoptosis-related genes to provide neuroprotection during ischemia and reperfusion. All animal experiments and procedures were approved by the Animal Ethics Committee of Sichuan University, China in January 2018(approval No. 2018013).

Dehydrocostuslactone protects against oxygen-glucose deprivation/reperfusion-induced injury by inhibiting autophagy and apoptosis in PC12 cells

OBJECTIVE TO investigate the neural protection of dehydrocostus lactone(DHL)against neuronal injury induced by oxygen and glucose deprivation/reperfusion(OGD/R)in differentiated PC12 cells.METHODS We used a cellular model of 2 h of OGD and 24 h of reperfusion to mimic cerebral ischemia-reperfusion injury.Cell viability was used to reflect the degree of OGD/R-induced injury.Cells were treated with DHL during the reperfusion phase.Cell Counting Kit(CCK-8)and LDH assays were performed to determine the optimal dose of DHL and cell viability.Flow cytometry analysis and Monodansylcadaverine(MDC)staining were then conducted to detect apoptosis rate and autophagosome formation after OGD/R in PC12 cells.Immunofluorescence and Western blotting analyses were used to detect the expres⁃sion of proteins associated with autophagy and apoptosis.RESULTS OGD/R significantly decreased cell viability and increased apoptosis rate.The expression levels of autophagy-related proteins,namely,LC3 and Beclin-1,and apoptosisrelated proteins,namely,Bax and caspase-3 increased,but that of the anti-apoptosis Bcl-2 protein decreased.However,DHL attenuated OGD/R-induced neuronal injury through inhibition of apoptosis and autophagy properties by modulating au⁃tophagy-associated proteins(LC3 and Beclin-1)and apoptosis-modulating proteins(caspase-3 and Bcl-2/Bax).CONCLU⁃SION Our data provide an evidence for the neuroprotective effect of DHL against ischemic neuronal injury.Hence,DHL could be a promising candidate for treatment of ischemic stroke.

Establishment of oxygen glucose deprivation reperfusion model of senescent SH-SY5Y cells

Obejective:To explore the establishment of an oxygen glucose deprivation/reperfusion model of senescent SH-SY5Y cells.Methods:SH-SY5Y cells were randomly divided into control(D-galactose 0 mmol/L group),D-galactose(25 mmol/L,50 mmol/L,100 mmol/L,200 mmol/L,400 mmol/L)groups,and treated with corresponding concentrations of D-galactose for 48 h.The changes of cell morphology,β-galactosidase,the cell morphology,β-galactosidase activity by microscopic observation,cell proliferation rate by EdU kit and cell survival rate by CCK-8 assay were used to determine the decaying concentration of D-galactose and to establish the senescence model.The senescent SH-SY5Y cells were randomly divided into control group(oxygen glucose deprivation without treatment group),oxygen glucose deprivation treatment(0.5 h,1 h,1.5 h,2 h)group,followed by re-glucose reoxygenation for 24 h,and CCK-8 assay for the survival rate of senescent SH-SY5Y cells.Results:There were no significant changes in cell morphology and β-gal activity in the 25 mmol/L and 50 mmol/L groups compared with the control group(P>0.05),cytosolic hypertrophy was seen in the cells of the 100 mmol/L group,chromatin fixation in the cells of the 200 mmol/L group,and massive vacuolization in the cells of the 400 mmol/L group;the positive rate ofβ-galactosidase staining in the cells of the(100-400 mmol/L)group was significantly higher compared with the control group(P<0.05),with little difference between the 100 mmol/L and 200 mmol/L groups(P>0.05);the cell proliferation ability of the(100-400 mmol/L)group was significantly decreased in a concentration-dependent manner(P<0.05);the cell survival rate was decreased in a concentration-dependent manner(P<0.05),with IC_(50) between 100 mmol/L and 200 mmol/L.The survival of senescent SH-SY5Y cells showed a time-dependent decrease in oxygen-glucose deprivation(P<0.05),with an IC_(50) close to 1 h.Conclusion:D-gal concentration of 100 mmoL/L and 48 h of cell action could establish a survival rate of about 50%of senescent SH-SY5Y cells,and oxygen glucose deprivation of senescent SH-SY5Y cells for 1 h and reperfusion for 24 h could establish an oxygen glucose deprivation/reperfusion model of senescent SH-SY5Y cells with a survival rate close to 50%.

Intervention Timing and Effect of PJ34 on Astrocytes During Oxygen-glucose Deprivation/reperfusion and Cell Death Pathways

Poly （ADP-ribose） polymerase-I （PARP-1） plays as a double edged sword in cerebral ischemia-reperfusion, hinging on its effect on the intracellular energy storage and injury severity, and the prognosis has relationship with intervention timing. During ischemia injury, apoptosis and oncosis are the two main cell death pathway sin the ischemic core. The participation of astrocytes in ische- mia-reperfusion induced cell death has triggered more and more attention. Here, we examined the pro- tective effects and intervention timing of the PARP-1 inhibitor PJ34, by using a mixed oxygen-glucose deprivation/reperfusion （OGDR） model of primary rat astrocytes in vitro, which could mimic the ische- mia-reperfusion damage in the ＂ischemic core＂. Meanwhile, cell death pathways of various P J34 treated astrocytes were also investigated. Our results showed that P J34 incubation （10 μmol/L） did not affect release of lactate dehydrogenase （LDH） from astrocytes and cell viability or survival 1 h after OGDR. Interestingly, after 3 or 5 h OGDR, P J34 significantly reduced LDH release and percentage of PI-positive cells and increased cell viability, and simultaneously increased the caspase-dependent apop- totic rate. The intervention timing study demonstrated that an earlier and longer P J34 intervention dur- ing reperfusion was associated with more apparent protective effects. In conclusion, earlier and longer PJ34 intervention provides remarkable protective effects for astrocytes in the ＂ischaemic core＂ mainly by reducing oncosis of the astrocytes, especially following serious OGDR damage.

Dynamic changes in proprotein convertase 2 activity in cortical neurons after ischemia/reperfusion and oxygen-glucose deprivation

In this study, a rat model of transient focal cerebral ischemia was established by performing 100 minutes of middle cerebral artery occlusion, and an in vitro model of experimental oxygen-glucose deprivation using cultured rat cortical neurons was established. Proprotein convertase 2 activity gradually decreased in the ischemic cortex with increasing duration of reperfusion. In cultured rat cortical neurons, the number of terminal deoxynucleotidyl transferase-mediated 2＇-deoxyuridine 5＇-triphosphate-biotin nick end labeling-positive neurons significantly increased and proprotein convertase 2 activity also decreased gradually with increasing duration of oxygen-glucose deprivation. These experimental findings indicate that proprotein convertase 2 activity decreases in ischemic rat cortex after reperfusion, as well as in cultured rat cortical neurons after oxygen-glucose deprivation. These changes in enzyme activity may play an important pathological role in brain injury.

Curcumin pretreatment and post-treatment both improve the antioxidative ability of neurons with oxygen-glucose deprivation

Recent studies have shown that induced expression of endogenous antioxidative enzymes thr- ough activation of the antioxidant response element/nuclear factor erythroid 2-related factor 2 （Nrf2） pathway may be a neuroprotective strategy. In this study, rat cerebral cortical neurons cultured in vitro were pretreated with 10 ktM curcumin or post-treated with 5 pM curcumin, respectively before or after being subjected to oxygen-glucose deprivation and reoxygenation for 24 hours. Both pretreatment and post-treatment resulted in a significant decrease of cell injury as indicated by propidium iodide/Hoechst 33258 staining, a prominent increase of Nrf2 protein expression as indicated by western blot analysis, and a remarkable increase of protein expression and enzyme activity in whole cell lysates of thioredoxin before ischemia, after ischemia, and after reoxygenation. In addition, post-treatment with curcumin inhibited early DNA/RNA oxidation as indicated by immunocytochemistry and increased nuclear Nrf2 protein by inducing nuclear accumulation of Nrf2. These findings suggest that curcumin activates the expression of thi- oredoxin, an antioxidant protein in the Nrf2 pathway, and protects neurons from death caused by oxygen-glucose deprivation in an in vitro model of ischemia/reperfusion. We speculate that pharmacologic stimulation of antioxidant gene expression may be a promising approach to neu- roprotection after cerebral ischemia.

Rac1 relieves neuronal injury induced by oxygen-glucose deprivation and re-oxygenation via regulation of mitochondrial biogenesis and function

Certain microRNAs(miRNAs)can function as neuroprotective factors after reperfusion/ischemia brain injury.miRNA-142-3p can participate in the occurrence and development of tumors and myocardial ischemic injury by negatively regulating the activity of Rac1,but it remains unclear whether miRNA-142-3p also participates in cerebral ischemia/reperfusion injury.In this study,a model of oxygen-glucose deprivation/re-oxygenation in primary cortical neurons was established and the neurons were transfected with miR-142-3p agomirs or miR-142-3p antagomirs.miR-142-3p expression was down-regulated in neurons when exposed to oxygen-glucose deprivation/re-oxygenation.Over-expression of miR-142-3p using its agomir remarkably promoted cell death and apoptosis induced by oxygen-glucose deprivation/re-oxygenation and improved mitochondrial biogenesis and function,including the expression of peroxisome proliferator-activated receptor-γcoactivator-1α,mitochondrial transcription factor A,and nuclear respiratory factor 1.However,the opposite effects were produced if miR-142-3p was inhibited.Luciferase reporter assays verified that Rac Family Small GTPase 1(Rac1)was a target gene of miR-142-3p.Over-expressed miR-142-3p inhibited NOX2 activity and expression of Rac1 and Rac1-GTPase(its activated form).miR-142-3p antagomirs had opposite effects after oxygen-glucose deprivation/re-oxygenation.Our results indicate that miR-142-3p down-regulates the expression and activation of Rac1,regulates mitochondrial biogenesis and function,and inhibits oxygen-glucose deprivation damage,thus exerting a neuroprotective effect.The experiments were approved by the Committee of Experimental Animal Use and Care of Central South University,China(approval No.201703346)on March 7,2017.

姜黄素通过PINK1/Parkin通路减轻OGD/R诱导的脑微血管内皮细胞损伤

目的:探究姜黄素激活PINK1/Parkin通路增强线粒体自噬,改善氧糖剥夺再灌注(OGD/R)引起内皮细胞损伤的作用机制。方法:建立小鼠脑微血管内皮细胞(BMECs)的OGD/R损伤模型,用不同浓度姜黄素处理内皮细胞,使用免疫荧光和透射电镜评估姜黄素对BMECs线粒体自噬的影响。细胞计数试剂盒8(CCK-8)、乳酸脱氢酶释放检测和跨内皮电阻值检测用于评估细胞增殖、损伤和屏障完整性。Western Blot检测姜黄素对PINK1/Parkin通路蛋白(LC-3 II/I、PINK1、Parkin及p62)表达的影响,采用Mdivi-1同时处理细胞,进一步确认线粒体自噬在姜黄素减轻OGD/R损伤中的作用。结果:姜黄素处理显著促进了线粒体自噬,并显著增加LC-3 II/I、PINK1和Parkin蛋白的表达(P<0.001),显著减少了p62蛋白的表达(P<0.001)。在OGD/R模型中,姜黄素显著提高了细胞增殖率(P<0.001),显著降低了乳酸脱氢酶释放(P<0.001),并显著改善了细胞屏障的电阻值(P<0.001)。而线粒体自噬抑制剂Mdivi-1可以逆转姜黄素的这些保护效果。结论:姜黄素通过激活PINK1/Parkin通路增强线粒体自噬,有效缓解BMECs在OGD/R条件下的细胞损伤。

Neuroprotective effects of salvianolic acid B against oxygen-glucose deprivation/reperfusion damage in primary rat cortical neurons

Background Cerebral ischemia-reperfusion injury is the main reason for the loss of neurons in the ischemic cerebrovascular disease. Therefore, to deeply understand its pathogenesis and find a new target is the key issue to be solved. This research aimed to investigate the neuroprotective effects of salvianolic acid B （SalB） against oxygen-glucose deprivation/reperfusion （OGD/RP） damage in primary rat cortical neurons.Methods The primary cultures of neonatal Wister rats were randomly divided into the control group, the OGD/RP group and the SalB-treatment group （10 mg/L）. The cell model was established by depriving of oxygen and glucose for 3 hours and reperfusion for 3 hours and 24 hours, respectively. The neuron viability was determined by MTT assay. The level of cellular reactive oxygen species （ROS） was detected by fluorescent labeling method and spin trapping technique respectively. The activities of neuronal Mn-superoxide dismutase （Mn-SOD）, catalase （CAT） and glutathione peroxidase （GSH-PX） were assayed by chromatometry. The mitochondria membrane potential （△ψm） was quantitatively analyzed by flow cytometry. The release rate of cytochrome c was detected by Western blotting. The neuronal ultrastructure was observed by transmission electron microscopy. Statistical significance was evaluated by analysis of variance （ANOVA）followed by Student-Newman-Keuls test.Results OGD/RP increased the level of cellular ROS, but decreased the cell viability and the activities of Mn-SOD, CAT and GSH-PX; SalB treatment significantly reduced the level of ROS （P ＜0.05）; and enhanced the cell viability （P ＜0.05）and the activities of these antioxidases （P ＜0.05）. Additionally, OGD/RP induced the fluorescence value of △ψm to diminish and the release rate of cytochrome c to rise notably; SalB markedly elevated the level of △ψm （P ＜0.01） and depressed the release rate of cytochrome c （P ＜0.05）; it also ameliorated the neuronal morphological injury.Conclusion The neuroprotection of SalB may be attributed to the elimination of ROS and the inhibition of apoptosis.

Activated Drp1 regulates p62-mediated autophagic flux and aggravates inflammation in cerebral ischemia-reperfusion via the ROS-RIP1/RIP3-exosome axis

Background: Cerebral ischemia-reperfusion injury(CIRI) refers to a secondary brain injury that can occur when the blood supply to the ischemic brain tissue is restored. However, the mechanism underlying such injury remains elusive.Methods: The 150 male C57 mice underwent middle cerebral artery occlusion(MCAO) for 1 h and reperfusion for 24 h,Among them, 50 MCAO mice were further treated with Mitochondrial division inhibitor 1(Mdivi-1) and 50 MCAO mice were further treated with N-acetylcysteine(NAC). SH-SY5Y cells were cultured in a low-glucose culture medium for 4 h under hypoxic conditions and then transferred to normal conditions for 12 h. Then, cerebral blood flow, mitochondrial structure, mitochondrial DNA(mtDNA) copy number, intracellular and mitochondrial reactive oxygen species(ROS),autophagic flux, aggresome and exosome expression profiles, cardiac tissue structure, mitochondrial length and cristae density, mtDNA and ROS content, as well as the expression of Drp1-Ser616/Drp1, RIP1/RIP3, LC3 II/I, TNF-α,IL-1β, etc., were detected under normal or Drp1 interference conditions.Results: The mtDNA content, ROS levels, and Drp1-Ser616/Drp1 were elevated by 2.2, 1.7 and 2.7 times after CIRI(P<0.05). However, the high cytoplasmic LC3 II/I ratio and increased aggregation of p62 could be reversed by 44%and 88% by Drp1 short hairpin RNA(shRNA)(P<0.05). The low fluorescence intensity of autophagic flux and the increased phosphorylation of RIP3 induced by CIRI could be attenuated by ROS scavenger, NAC(P<0.05). RIP1/RIP3inhibitor Necrostatin-1(Nec-1) restored 75% to a low LC3 II/I ratio and enhanced 2 times to a high RFP-LC3 after Drp1 activation(P<0.05). In addition, although CIRI-induced ROS production caused no considerable accumulation of autophagosomes(P>0.05), it increased the packaging and extracellular secretion of exosomes containing p62 by 4–5 times, which could be decreased by Mdivi-1, Drp1 shRNA, and Nec-1(P<0.05). Furthermore, TNF-α and IL-1βincreased in CIRI-derived exosomes could increase RIP3 phosphorylation in normal or oxygen–glucose deprivation/reoxygenation(OGD/R) conditions(P<0.05).Conclusions: CIRI activated Drp1 and accelerated the p62-mediated formation of autophagosomes while inhibiting the transition of autophagosomes to autolysosomes via the RIP1/RIP3 pathway activation. Undegraded autophagosomes were secreted extracellularly in the form of exosomes, leading to inflammatory cascades that further damaged mitochondria, resulting in excessive ROS generation and the blockage of autophagosome degradation,triggering a vicious cycle.

Long non-coding RNA MEG3 regulates autophagy after cerebral ischemia/reperfusion injury

Severe cerebral ischemia/reperfusion injury has been shown to induce high-level autophagy and neuronal death.Therefore,it is extremely important to search for a target that inhibits autophagy activation.Long non-coding RNA MEG3 participates in autophagy.However,it remains unclear whether it can be targeted to regulate cerebral ischemia/reperfusion injury.Our results revealed that in oxygen and glucose deprivation/reoxygenation-treated HT22 cells,MEG3 expression was obviously upregulated,and autophagy was increased,while knockdown of MEG3 expression greatly reduced autophagy.Furthermore,MEG3 bound mi R-181 c-5 p and inhibited its expression,while mi R-181 c-5 p bound to autophagy-related gene ATG7 and inhibited its expression.Further experiments revealed that mir-181 c-5 p overexpression reversed the effect of MEG3 on autophagy and ATG7 expression in HT22 cells subjected to oxygen and glucose deprivation/reoxygenation.In vivo experiments revealed that MEG3 knockdown suppressed autophagy,infarct volume and behavioral deficits in cerebral ischemia/reperfusion mice.These findings suggest that MEG3 knockdown inhibited autophagy and alleviated cerebral ischemia/reperfusion injury through the mi R-181 c-5 p/ATG7 signaling pathway.Therefore,MEG3 can be considered as an intervention target for the treatment of cerebral ischemia/reperfusion injury.This study was approved by the Animal Ethics Committee of the First Affiliated Hospital of Zhengzhou University,China(approval No.XF20190538)on January 4,2019.

The pathways by which mild hypothermia inhibits neuronal apoptosis following ischemia/reperfusion injury

Several studies have demonstrated that mild hypothermia exhibits a neuroprotective role and it can inhibit endothelial cell apoptosis following ischemia/reperfusion injury by decreasing casp- ase-3 expression, It is hypothesized that mild hypothermia exhibits neuroprotective effects on neurons exposed to ischemia/reperfusion condition produced by oxygen-glucose deprivation. Mild hypothermia significantly reduced the number of apoptotic neurons, decreased the expres- sion of pro-apoptotic protein Bax and increased mitochondrial membrane potential, with the peak of anti-apoptotic effect appearing between 6 and 12 hours after the injury. These findings indicate that mild hypothermia inhibits neuronal apoptosis following ischemia/reperfusion injury by protecting the mitochondria and that the effective time window is 6-12 hours after ischemia/reperfusion injury.

肌肽通过抑制ROS/NLRP3/GSDMD介导的焦亡减轻OGD/R对BV2细胞损伤

目的探究肌肽对氧糖剥夺/复糖复氧(OGD/R)诱导BV2细胞损伤的保护作用及对ROS/NLRP3/GSDMD通路介导焦亡的影响。方法BV2细胞随机分为对照组(Con)、模型组(OGD/R)、肌肽组(OGD/R+CAR)、抑制剂组(OGD/R+MCC950)、肌肽+抑制剂组(OGD/R+CAR+MCC950)。采用MTT法检测细胞存活率;微量酶标法检测细胞上清液中乳酸脱氢酶(LDH)释放率;Hoechst 33342/SYTOX Green染色法检测细胞损伤情况;DCFH-DA检测细胞中ROS水平;免疫荧光观察细胞内NF-κB p65入核水平;Western blot检测细胞NLRP3、ASC、cleaved caspase-1、GSDMD-N的蛋白表达水平;ELISA检测细胞上清液中IL-1β、IL-18水平。结果与Con组相比,OGD/R组细胞存活率明显降低,LDH释放明显升高,细胞形态受损,SYTOX Green阳性率与细胞中ROS水平明显升高,细胞核中NF-κB p65荧光强度增强,细胞内NLRP3、ASC、cleaved caspase-1、GSDMD-N蛋白表达水平及IL-1β、IL-18水平明显升高。与OGD/R组相比,其他组的细胞存活率明显升高,LDH释放率明显降低,细胞损伤得到一定程度的改善,SYTOX Green阳性率和细胞中ROS生成水平明显降低,细胞核中NF-κB p65荧光强度明显降低,相关蛋白表达水平及细胞上清液中IL-1β、IL-18水平明显降低。结论肌肽通过抑制氧化应激及NF-κB激活,进而抑制NLRP3/GSDMD信号途径的焦亡对OGD/R致BV2细胞损伤发挥保护作用。

Neuroprotective effect of penehyclidine hydrochloride on focal cerebral ischemia-reperfusion injury

Penehyclidine hydrochloride can promote microcirculation and reduce vascular permeability. However, the role of penehyclidine hydrochlodde in cerebral ischemia-reperfusion injury remains unclear. In this study, in vivo middle cerebral artery occlusion models were established in experimental rats, and penehyclidine hydrochloride pretreatment was given via intravenous injection prior to model establishment. Tetrazolium chloride, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling and immunohistochemical staining showed that, penehyclidine hydrochloride pretreatment markedly attenuated neuronal histopathological changes in the cortex, hippocampus and striatum, reduced infarction size, increased the expression level of BcI-2, decreased the expression level of caspase-3, and inhibited neuronal apoptosis in rats with cerebral ischemia-reperfusion injury. Xanthine oxidase and thiobarbituric acid chromogenic results showed that penehyclidine hydrochloride upregulated the activity of superoxide dismutase and downregulated the concentration of malondialdehyde in the ischemic cerebral cortex and hippocampus, as well as reduced the concentration of extracellular excitatory amino acids in rats with cerebral ischemia-reperfusion injury. In addition, penehyclidine hydrochloride inhibited the expression level of the NR1 subunit in hippocampal nerve cells in vitro following oxygen-glucose deprivation, as detected by PCR. Experimental findings indicate that penehyclidine hydrochloride attenuates neuronal apoptosis and oxidative stress injury after focal cerebral ischemia-reperfusion, thus exerting a neuroprotective effect.

蛇葡萄素通过调节JAK2/STAT3信号通路减轻OGD/R诱导的神经元损伤

目的探讨蛇葡萄素(AMP)对氧糖剥夺/再灌注(OGD/R)诱导的神经元损伤的影响及其作用机制,为新生儿缺氧缺血性脑损伤的研究奠定基础。方法分离并体外培养新生SD大鼠神经元细胞,分为5组:对照组(AMP浓度为0μmol/L)、OGD/R组、AMP低剂量组(OGD/R处理+AMP 20μmol/L)、AMP高剂量组(OGD/R处理+AMP 30μmol/L)、JAK2/STAT3激活剂组(OGD/R处理+AMP 30μmol/L+Coumermycin A110μmol/L)。CCK-8法检测不同处理组细胞活力;乳酸脱氢酶(LDH)试剂盒检测培养基中LDH活性;流式细胞术检测细胞凋亡率;酶联免疫吸附试验检测白细胞介素6(IL-6)、白细胞介素10(IL-10)、肿瘤坏死因子α(TNF-α)水平;试剂盒检测活性氧(ROS)、丙二醛(MDA)、超氧化物歧化酶(SOD)水平;Western blotting检测凋亡相关蛋白B淋巴细胞瘤-2(Bcl-2)、Bcl-2相关X蛋白(Bax)、酶切含半胱氨酸的天冬氨酸蛋白水解酶-3(C-caspase-3)、酪氨酸激酶2(JAK2)、磷酸化JAK2(p-JAK2)、信号传导及转录活化因子3(STAT3)、磷酸化STAT3(p-STAT3)表达情况。结果与AMP浓度为0μmol/L比较,AMP浓度为5~30μmol/L时,细胞活力比较差异无统计学意义(P>0.05),AMP浓度为40μmol/L细胞活力明显下降(P<0.05)。与对照组比较,OGD/R组细胞活力、SOD、IL-10、Bcl-2水平明显下降,LDH活性、细胞凋亡率、ROS荧光强度、MDA、IL-6、TNF-α、Bax、C-caspase-3、p-JAK2/JAK2、p-STAT3/STAT3水平明显升高(P<0.05)。与OGD/R组比较,AMP低、高剂量组神经元细胞活力、SOD、IL-10、Bcl-2水平上升,LDH活性、细胞凋亡率、ROS荧光强度、MDA、IL-6、TNF-α、Bax、C-caspase-3、p-JAK2/JAK2、p-STAT3/STAT3水平下降(P<0.05),而JAK2/STAT3激活剂可逆转AMP对OGD/R诱导的神经元细胞损伤的保护作用。结论AMP通过减少氧化应激和炎症反应减轻OGD/R诱导的神经元细胞损伤,其作用机制可能与抑制JAK2/STAT3信号通路磷酸化有关。

Protective Effect of Salvianolic Acid A on Brain Endothelial Cells after Treatment with Deprivation and Reperfusion of Oxygen-glucose

Objective Salvianolic acid A（SAA） has a significant protective effect on ischemia/reperfusion injury of brain. However, it is not clear for SAA to exert its cerebral protection by targeting at the microvascular endothelial cells of blood brain barrier（BBB）. Our previous study demonstrated that SAA could hardly pass through the BBB. This present study was therefore designed to investigate the protective effect of SAA on brain microvascular endothelial cells（BMECs） induced by deprivation and reperfusion with oxygen-glucose. Methods Rat BMECs were treated with oxygen glucose deprivation（OGD）, followed by reperfusion（OGD/R）. Cell viability was assessed by MTT and the content of reactive oxygen species（ROS） in cells after OGD/R in the absence or presence of SAA. GC-MS based metabolomic platform was applied to evaluate the regulation of SAA on the cellular metabolic perturbation induced by OGD/R. Results OGD/R significantly increased the production of intracellular reactive oxygen species（ROS）, and decreased the activity of cells. SAA significantly reduced ROS and improve the cell viability. Metabolomic study revealed distinct perturbation of metabolic pathways of energy metabolism in the BMEC induced by OGD/R, while SAA significantly regulated the perturbed metabolism involved in energy metabolism pathways, especially for intermediates in TCA cycle. Conclusion SAA shows protective effects on BMECs involved in central nervous system.

Icariside Ⅱ, a PDE5 inhibitor, attenuates cerebral ischemia/reperfusion injury through activating BDNF/TrkB/CREB signaling pathway

OBJECTIVE To explore the effects and mechanism of icariside Ⅱ(ICS Ⅱ),a pharmacologically active compound derived from herbal Epimedii with previous study-proved phosphodiesterase 5(PDE5) inhibitors,was investigated in vivo using a middle cerebral artery occlusion/reperfusion(MCAO/R) model in rats and in vitro using an oxygen-glucose deprivation/reperfusion(OGD/R) model in primary hippocampal neurons.METHODS Laser Doppler flowmeter was introduced to examine the cerebral blood flow of MCAO/R rats.The neurological deficits scores,brain water content and infarction volume were assessed after MCAO/R.OGD/R-induced primary hippocampal neuronal injury and apoptosis were examined by MTT,lactate dehydrogenase(LDH) release,TUNEL staining and flow cytometry,respectively.Expressions of PDE5 A and memory-related signaling pathways were measured using Western blotting analysis.The direct interaction between ICS Ⅱand PDE5 was further evaluated by molecular docking.RESULTS ICS Ⅱ significantly decreased the infraction volume in MCAO/R rats.Furthermore,ICS Ⅱ significantly abrogated OGD/R-induced hippocampal neuronal death.Moreover,ICSⅡ not only effectively restored the 3′ 5′-cyclic guanosine monophosphate(cGMP) level and protein kinase G(PKG) activity both in vivo and in vitro,but also increased brain-derived neurotrophic factor(BDNF),tyrosine protein kinase B(TrkB) and cAMP response element-binding protein(CREB) expressions,thereby inhibited hippocampal neuronal apoptosis.Mechanistically,the beneficial effects of ICS Ⅱ was attributed to its activation of the PKG/TrkB/BDNF via increasing BDNF expression,evidenced by that the inhibition effects of ICSⅡ was abrogated by Rp-8-BrcGMPS,a PKG inhibitor,or ANA-12,a TrkB inhibitor.ICSⅡ also decreased both protein level and activity of PDE5.Notably,ICSⅡ might effectively bind and inhibite PDE5 as demonstrated by relatively high binding score.CONCLUSION ICSⅡ significantly protect against cerebral ischemia/reperfusion injury in rats and rescues OGD/Rinduced hippocampal neuronal injury,and the underling mechanisms are,at least partly,due to inhibition of PDE5 and activation of BDNF/TrkB/CREB signaling pathway.Hence ICS Ⅱ may be an effective agent for combating cerebral ischemia/reperfusion injury.

大鼠大脑皮质神经细胞氧糖剥夺再复氧(OGD/R)后自噬对凋亡的抑制作用

目的 观察大脑皮质神经元氧糖剥夺再复氧(OGD/R)后自噬对凋亡的影响。方法 取18只出生在24 h内的新生SD大鼠,采用机械分离胰蛋白酶消化法提取大脑皮质神经元培养7 d后,建立OGD/R模型,随机分为3组,正常对照组、OGD/R组、OGD/R联合巴弗洛霉素A1(BafA1)组。采用CCK-8法和乳酸脱氢酶(LDH)实验检测细胞活力,用异硫氰酸荧光素标记的膜联素Ⅴ/碘化丙啶(annexinⅤ-FITC/PI)双标记结合流式细胞术检测细胞凋亡,采用反转录PCR法检测微管相关蛋白1轻链3(LC3)、 P62及胱天蛋白酶3(caspase-3)的mRNA表达,Western blot法检测LC3、 P62及caspase-3的蛋白表达。采用红色荧光蛋白-绿色荧光蛋白-LC3(RFP-GFP-LC3)腺病毒转染神经细胞检测自噬荧光强度,透射电子显微镜观察自噬体的超微结构变化。结果 与对照组相比,OGD/R组神经细胞活力明显降低,LDH释放水平明显升高,凋亡增加;LC3、 P62、 caspase-3的mRNA和蛋白表达增强;RFP荧光强度增加,自噬体增加且自噬溶酶体更加聚集,加用自噬晚期抑制剂BafA1后RFP荧光强度显著降低。结论 OGD/R诱导了神经元细胞的自噬和凋亡,抑制自噬后加重了神经细胞的损伤和凋亡。

CTRP3通过激活SIRT1/FOXO3a途径减轻OGD/R诱导的心肌细胞损伤

目的:探究CTRP3在糖氧剥夺/再灌注(OGD/R)诱导的心肌细胞损伤中的作用及其可能的作用机制。方法:体外培养大鼠心肌细胞H9c2,OGD/R诱导H9c2细胞损伤。qRT-PCR法检测细胞CTRP3、SIRT1和FOXO3a mRNA表达;Western blot检测细胞CTRP3、SIRT1、FOXO3a、Bax、Bcl-2和cleaved caspase-3蛋白表达,CCK-8检测细胞存活,流式细胞术检测细胞凋亡,检测细胞CK-MB、cTnI、SOD和MDA活性、GSH-Px含量及ROS的产生。结果:与Control组相比,OGD/R组细胞中CTRP3、SIRT1和FOXO3a mRNA以及蛋白表达,细胞存活率、Bcl-2蛋白表达、SOD和GSH-Px活性明显降低,细胞凋亡率、Bax和cleaved caspase-3蛋白表达、CK-MB、cTnI和MDA含量、ROS荧光强度明显升高(P<0.05)。OGD/R组与oe-NC组细胞各指标比较,差异无统计学意义(P>0.05)。与oe-NC组相比,oe-CTRP3组细胞中CTRP3、SIRT1和FOXO3a mRNA以及蛋白表达,细胞存活率、Bcl-2蛋白表达、SOD和GSH-Px活性明显升高(P<0.05),细胞凋亡率、Bax和cleaved caspase-3蛋白表达、CKMB、cTnI和MDA含量、ROS荧光强度明显降低(P<0.05)。与oe-CTRP3组相比,oe-CTRP3+EX527组细胞中SIRT1、FOXO3a和Bcl-2蛋白表达、细胞存活率、SOD和GSH-Px活性明显降低,细胞凋亡率、Bax和cleaved caspase-3蛋白表达、CK-MB、cTnI和MDA含量、ROS荧光强度明显升高(P<0.05)。与oe-CTRP3+EX527组相比,oe-CTRP3+EX527+oe-FOXO3a组细胞中FOXO3a和Bcl-2蛋白表达,细胞存活率、SOD和GSH-Px活性明显升高,细胞凋亡率、Bax和cleaved caspase-3蛋白表达、CKMB、cTnI和MDA含量、ROS荧光强度明显降低(P<0.05)。结论:CTRP3通过激活SIRT1/FOXO3a途径促进OGD/R诱导的心肌细胞存活,抑制细胞凋亡和氧化应激。