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OBJECTIVE：To study the improvement effects and mechanism of Polygonum orientale flower extract on hypoxia- reoxygenation injury of H 9c2 cardiomyocytes. METHODS ：H9c2 cardiomyocytes were divided into normal control group ，model group and low- ，medium- and high-concentrations groups of P. orientale flower extract （20，40，80 μg/mL）. Except for normal control group ，other groups were given 800 μmol/L CoCl2 to induce hypoxia-reoxygenation injury model. Cell apoptosis was observed. The levels of Ca 2+（in cytoplasm ），mitochondrial membrane potential （MMP），ATP enzyme （Na+-K+-ATP enzyme ，Ca2+-Mg2+-ATP enzyme） activities， the ratio of cytochrome c （Cyto c ）， protein in cytosol to mitochondria ，phosphorylation levels of reperfusion injury salvage kinase （RISK） signaling pathwayrelated protein [protein kinase B （Akt）and extracellular signal regulated kinase 1/2（ERK1/2）] as well as protein expression of HIF- 1 α were detected respectively. In addition，the cells were divided into normal control group ，model group and P. orientale flower extract group （80 μ g/mL），PI3K inhibitor LY294002+CoCl2 group（15 μmol/L LY294002+80 μmol/L ，LY294002+P. orientale flower extract group （15 μmol/L LY294002+80 μg/mL P. orientale flower extract ），MEK inhibitor PD98059+CoCl2 group（25 μmol/L PD98059+800 μmol/L CoCl2），PD98059+P. orientale flower extract group （25 μmol/L PD98059+80 μg/mL P. orientale flower extract ）. After cultured by the same method ，the phosphorylation levels of Akt protein and ERK1/2 protein in the cells were measured to verify the activation of P. orientale flower extract to RISK signaling pathway. RESULTS：Compared with model group ，nuclear pyknosis and the number of apoptotic bodies were reduced in different concentrations groups of P. orientale flower extract. ROS level ，Ca2+ level（except for low-concentration group ），MMP，ratio of Cyto c in cytoplasm to Cyto c in mitochondria ，protein expression of HIF- 1α were decreased significantly（P＜0.05 or P＜0.01）； the activity of ATP enzyme （except for the low-concentration group ），Akt protein and ERK 1/2 protein phosphorylation level were significantly increased （P＜0.01）. After treated with PI 3K inhibitor LY 294002 and MEK inhibitor PD 98059，Akt protein and ERK 1/2 protein phosphorylation level in cadiomyocyte were decreased significantly （P＜0.05 or P＜0.01）. CONCLUSIONS ：P. orientale flower extract can improve hypoxia-reoxygenation injury of H 9c2 cardiomyocytes，the mechanism of which may be associated with inhibiting cardiomyocyte apoptosis ，improving ATPase activity ，protecting mitochondria ，regulating RISK signaling pathway related proteins and HIF- 1α protein expression.
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Objective To study the protective effect of Shengxian decoction and the single herb decoction against myocardial injury induced by hypoxia/reoxygenation. Methods The H9c2 cells were cultured to establish hypoxia/reoxygenation model. Rats were divided into 8 groups: normal control group, hypoxia/reoxygenation group (model group) and treated groups (Shengxian decoction and the single herb decoction). The apoptotic rate of cardiomyocytes, the activity of reactive oxygen species (ROS) and intracellular calcium concentration (Ca2+) were measured. Results Compared with hypoxia/reoxygenation group, the apoptosis rate, ROS activity and intracellular Ca2+ concentration were significantly lower in all treated groups (P<0.05). The ROS activity and intracellular Ca2+ concentration was decreased by 41.37% and 15.20% in Shengxian decoction group compared to the model group. Conclusion Shengxian decoction and the single herb decoction had protective effect on myocardial injury induced by hypoxia/reoxygenation.
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OBJECTIVE: To investigate the effect of remifentanil postconditioning on myocardial hypoxia/reoxygenation (H/R) injury in adults, and to further explore the role of aquaporin-4 (AQP-4) in mediating this effect. METHODS: Trabecular muscles from the right atrial appendage of adults were treated with hypoxia for 90 min, followed by reoxygenation for 120 min. Then, remifentanil 0.01, 0.1 and 1.0 nmol·L-1was infused 10 min before the end of hypoxia until 10 min after the start of reoxygenation. The contractile tension of the trabecular muscles was monitored during the experiment. Western blotting was performed to evaluate AQP-4 expression at the end of the experiment. RESULTS: Compared with normal control group, muscle tension decreased significantly after 30 min of induction in H/R group (P<0.05), and it was reduced to the minimum at 90 min. The muscle tension at 150 min and 180 min in remifentanil 0.1 nmol·L-1group was higher than that in H/R group (P<0.05). The muscle tension in remifentanil 1.0 nmol·L-1group was higher than that in H/R group during reoxygenation (P<0.05). Compared with normal control group, the expression of AQP-4 protein in H/R group was significantly higher (P< 0.05), whereas the expression of AQP-4 in remifentanil 0.1 and 1.0 nmol·L-1groups was down-regulated compared with H/R group (P<0.05). CONCLUSION: Remifentanil can alleviate myocardial H/R injury in adults, and its effect may be related to the decreased expression of AQP-4.
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This study was designed to investigate the effect and mechanism of astragaloside IV (ASIV) on mitochondrial morphology and function of rat cardiomyocytes under hypoxia/reoxygenation injury. H9c2 cells were divided into control group, hypoxia/reoxygenation (H/R) group, and H/R + ASIV group. Cell viability and lactate dehydrogenase (LDH) leakage were measured by cell counting kit-8 (CCK-8) and LDH assay kit, respectively. Oxidative stress levels, such as superoxide dismutase (SOD), glutathione (GSH), and malondialdehyde (MDA), were analyzed by commercial kits. Intracellular and mitochondrial reactive oxygen species (ROS) levels were detected by dihydroethidium (DHE) and MitoSOX. Changes of the mitochondrial membrane potential were detected using the fluorescent probe JC-1. Opening of mitochondrial permeability transition pore was examined via calcein acetoxymethyl ester (calcein-AM). Apoptosis was assessed using terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL) assay kit. To detect protein expression of dynamin-related protein 1 (Drp1), mitofusin1 (Mfn1), Mfn2, Bax, B-cell lymphoma-2 (Bcl-2), and cleaved cysteine-aspartic protease (caspase)-3, Western blot analysis was carried out. Compared with the control group, ASIV (100 μmol·L-1) significantly improved H/R induced cell injury, LDH leakage, decrease of SOD activity, and GSH content, increase of MDA content and ROS content, loss of mitochondrial membrane potential, mitochondrial permeability transition pore opening, ROS production activation, mitochondrial fission/fusion imbalance, and cell apoptosis. In addition, the effect of ASIV against H/R injury was also verified on primary rat cardiomyocytes. The animal welfare and experimental process follow the rules of Animal Ethics Committee of Zhejiang Chinese Medical University. In conclusion, ASIV may play a protective role in mitochondria by regulating morphological dynamic stability and mitochondrial function, inhibiting excessive synthesis of ROS, improving the internal environment of oxidative stress, reducing cell apoptosis, and thereby protecting against cardiomyocytes’ hypoxia/reoxygenation injury.
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OBJECTIVE：To study spectrum-effect relationship of 11 different solvent extracts from Trollius chinensis against hypoxia/reoxygenation injury of cardiomyocyte . METHODS ：HPLC-MS/MS method was used to establish the fingerprints of 11 different solvent extracts from T. chinensis ，the compounds corresponding to the common peaks were identified by comparing with the substance control and literature information. MTT assay was used to detect the effects of 11 different solvent extracts from T. chinensis on the survival rate of rat myocardial H 9c2 cells injured by hypoxia/reoxygenation. The MDA content ，ROS level in cells and LDH content in the supernatant were detected by ELISA. GRA and PLS method were used to analyze the spectrum-effect relationship between the compounds corresponding to common peak and anti-hypoxia/reoxygenation injury of cardiomyocyte （drug effect）. RESULTS ：There were 22 common peaks in 11 different solvent extracts from T. chinensis ，and 22 compounds were identified. Compared with hypoxia/reoxygenation injury group ，survival rate of hypoxia/reoxygenation injury+S 1-S6，S9 and S 10 groups were increased significantly ，while MDA content ，ROS level and LDH content were decreased significantly （P＜0.05）； ROS level and LDH content of hypoxia/reoxygenation injury+S 8 group w ere decreased significantly （P＜0.05）. The r of GRA analysis of 22 compounds with drug effects were all higher than 0.8. Except for peaks 1，2，7，13，14 and 21，r of PLS analysis of rest peaks with drug effects were higher than 0 发。电话：0431-86058683。E-mial：nml2000@163.com （being positive correlation ）. Top 9 common peaks in the list of contribution rate were peak 6＞11＞4＞5＞8＞9＞12＞10＞15. CONCLUSIONS ：Orientin（peak 6），vitexin（peak 11）， orientin-2″-O-β-L-galacto- pyranosl （peak 4），orientin-2″-O-β-D-Pyrine xylosides （peak 5），quercetin-3-O-glucopyranoside（peak 8），vitexin-2″-O-β-L-galactoside（peak 9），hyperoside（peak 12），vitexin-2″-O-β-D-pyrine xylosides （peak 10），2″-O-（2″′- methylbutyry-loxy）-orientin（peak 15）may be the main components of anti-hypoxia/reoxygenation injury of cardiomyocytes.
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Objective To observe the protective effect of bisoprolol against hypoxia/reoxygenation injury of cardiac microvascular endothelial cells and explore the mechanism. Methods Left ventricular of cardiac microvascular endothelial cells (CMECs) were isolated from 8-week-old male C57BL/6N mice. CMECs were randomized into four groups: control group, vehicle group, hypoxia/reoxygenation group (H/R group), hypoxia/reoxygenation + bisoprolol group. The level of cell proliferation, apoptosis, superoxide anion, Cleaved caspase-3 and Nox2 expression were measured in each group. Results Compared with control group, H/R group had lower cell proliferation, higher apoptotic level, more superoxide anion level and the expression of Cleaved caspase-3 and Nox2 (P < 0.05). Furthermore, bisoprolol reversed hypoxia/reoxygenation-induced the decreased cell proliferation, the increased apoptosis, superoxide anion level, Cleaved caspase-3 and Nox2 expression (P < 0.05). Conclusion Bisoprolol can protect CMECs against hypoxia/reoxygenation injury by reducing the expression of Nox 2 that decreases oxidative stress.
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Aim: To establish the standard hypoxia/reoxygenation (H/R) injury model of H9c2 myocardial cells and evaluate the intervention effect of notoginsenoside R, based on RTCA technology. Methods: H9c2 myocardial cells were inoculated into the E-Plate board, 3 wells by a group, then the growth curve and cell index of different hypoxia time, different reoxygenation time and notoginsenoside R, intervention were determined respectively, with the growth status of H9c2 myocardial cells reflected by cell index. Results: Cell survival rate was (48.82 ±5.32)% after hypoxia treatment for 4h and reoxygenation treatment for 16h with replacement of serum-free, glucose-free DMEM medium before hypoxia, and no significant difference was found between the results measured with MTT method. Notoginsenoside R, could protect the hypoxia/reoxygenation injury of H9c2 myocardial cells without time dependence. Conclusions: RTCA technology is an effective means to establish the standard H/R injury model of H9c2 myocardial cells, which also has some guiding significance in discovering new drug targets and mechanisms.
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@#To study the protective effects of Roudoukou-8 San extract on hypoxia/reoxygenation injury of cardiac myocytes and its relationship with tyrosine protein kinase 2(JAK2)/signal transducer and activator 3(STAT3)signaling pathway, hypoxia/reoxygenation injury model of H9c2 cells was built by sodium dithionite(Na2S2O4). The vitality of the cells was tested by CCK-8; the contents of lactate dehydrogenase(LDH), creatine phosphate kinase(CK)and aspartate aminotransferase(AST)in cell culture medium were tested by fully automatic biochemical analyzer; the contents of catalase(CAT), superoxide dismutase(SOD)and glutathione peroxidase(GSH-Px)in cells were tested by kits; cell apoptosis degree was tested by hoechst staining. And the protein expressions of JAK2, p-JAK2, STAT3, p-STAT3, Bcl-2 and Bax in myocardial cells of each group were tested by Western blot. Hypoxia for 1 hour and reoxygenation for 3 hours of 2 mmol/L Na2S2O4 caused damage of about 50% H9c2 cells. Compared with the model group, the extracts of Roudoukou-8 San with different concentrations could increase the viability of cells. Besides, contents of CK, LDH and AST in cell culture medium were decreased significantly, while contents of CAT, SOD and GSH-Px were increased significantly. At the same time, the expression of p-JAK2, p-STAT3 and Bcl-2 were significantly increased and that of Bax was significantly decreased. The effects of Roudoukou-8 San extract could bereduced by AG490 blocker. Therefore, Roudoukou-8 San extract possesses protective effects on Na2S2O4 induced-hypoxia/reoxygenation injury of cardiac myocytes through JAK2/STAT3 signaling pathway.
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Objective: To investigate the effect of Trichosanthis Pericarpium aqueous extract(TPAE)in protecting H9c2 cells from hypoxia/reoxygenation (H/R) injury by activating phosphatidylionsitol-3-kinase/protein kinase B/nitric oxide(PI3K/Akt/NO) signaling pathway. Method: The 2.5 mmol·L-1 Na2S2O4 was used to induce the model of H9c2 cardiomyocytes H/R injury in the experiments. The cultured H9c2 cardiomyocytes were randomly divided into normal group, H/R group (model group) and inhibition group (LY294002, 10 μmol·L-1). In the H/R + TPAE group, 50 mg·L-1 TPAE was added to the cultures at 24 h before H/R exposure. Cell viability was measured by methyl thiazolyl tetrazolium (MTT) assay. The amounts of NO, endothelial nitric oxide synthase (eNOS), and induced nitric oxide synthase (iNOS) were tested by enzyme linked immunosorbent assay (ELISA) kits. Reverse transcription-quantitative real-time polymerase chain reaction (Real-time PCR) was performed to analyze relative mRNA expressions of Akt, eNOS and iNOS. Western blot was used to detect the expressions of Akt, p-Akt (Ser 473), eNOS, and iNOS. Result: Compared with the normal control group,the cell viability significantly decreased in the model control group (PPPPPPPPConclusion: TPAE can protect H9c2 cardiomyocytes from H/R injury by activating PI3K/Akt signaling pathway,which might be related to the up-regulation of the mRNA and protein expressions of eNOS, the down-regulation of the level of iNOS, and the increase of the production of physiological amounts of NO.
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OBJECTIVE： To investigate the protective effects of anemarsaponin B on hypoxia/reoxygenation injury astrocytes and its possible mechanism. METHODS： The primary astrocytes of neonatal SD rats were cultured and identified， and then randomly divided into normal group， model group， positive control group （nimodipine， 10 μmol/L）， anemarsaponin B low-dose， medium-dose and high-dose groups （1， 10， 100 μmol/L）， respectively. Normal group and model group were given complete medium 1 000 μL. Administration group was given complete medium with relevant medicine 1 000 μL. Except for normal group， hypoxia/reoxygenation injury model was established by oxygen-glucose deprivation/reperfusion in other groups. After reoxygenation， relative release rate of lactate dehydrogenase （LDH） in cell was detected by colorimetry. MTT assay was used to detect the relative viability of the cells. The contents of aquaporin 4 （AQP-4）， IL-6， IL-1β and TNF-α in cell were measured by ELISA. RESULTS： Compared with normal group， relative release rate of LDH， the contents of AQP-4， IL-6， IL-1β and TNF-α in cell were increased significantly in model group， while relative viability of the cells were decreased significantly （P＜0.01）. Compared with model group， relative release rate of LDH， the contents of AQP-4， IL-6， IL-1β and TNF-α in cell were decreased significantly in administration groups， while relative viability of the cells were increased significantly （P＜0.05 or P＜0.01）. CONCLUSIONS： Anemarsaponin B can significantly decrease cell injury degree， strengthen cell viability and protect hypoxia/reoxygenation injury astrocytes to certain extent. The effect may be related to the down-regulation of the secretion of AQP-4， IL-6， IL-1β and TNF-α.
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OBJECTIVE： To study the protective effects of Pericarpium Trichosanthis extract（TPE） on H9c2 myocardial cells injured by hypoxia/reoxygenation（H/R）. METHODS： H/R injury model of H9c2 myocardial cells was established by using sodium dithionite （Na2S2O4） as chemical hypoxia agent. The modeling conditions of different concentrations of Na2S2O4 （0.625-10 mmol/L） and different time of hypoxia （10-60 min） and reoxygenation （2-8 h）， as well as the concentration of TPE （12.5-400 μg/mL） were screened. The cultured H9c2 myocardial cells were randomly divided into normal group， model group， TPE different dose groups （TPE low-dose， medium-dose and high-dose groups， 25， 50， 100 μg/mL） and positive control group （quercetin， 25 μmol/L）. They were pre-treated with relevant medicine for 24 h， and then H/R injury model was established. Cell viability was measured by MTT assay. The levels of LDH， CK-MB， SOD and MDA in cells were tested by ELISA. Apoptosis of H9c2 myocardial cells were observed by flow cytometry. Western blotting was used to detect the protein expression of Bax and Bcl-2 in cells. RESULTS： The condition of H/R injury modeling included modeling concentration of Na2S2O4 2.5 mmol/L， hypoxia time 30 min， reoxygenation time 4 h. 12.5-400 μg/mL TPE showed no toxicity to H9c2 myocardial cells. After treatment， compared with blank group， survival rate and apoptotic rate of H9c2 myocardial cells in model group were increased significantly； the levels of CK-MB， LDH and MDA were increased significantly， while SOD level was decreased significantly； protein expression of Bax and Bax/Bcl-2 ratio were increased significantly， while that of Bcl-2 was decreased significantly （P＜0.05 or P＜0.01）. Compared with model group， above changes of H9c2 myocardial cells were reversed in all dose groups of TPE （P＜0.05 or P＜0.01）. CONCLUSIONS： TPE can protect H9c2 myocardial cells against H/R injury. Its mechanism may be associated with inhibiting the increase of lipid peroxide， improving the ability of scavenging reactive oxygen free radicals， up-regulating the protein expression of Bcl-2 or down-regulating protein expression of Bax， so as to inhibit the cell apoptosis.
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Astragaloside Ⅳ(AS-Ⅳ) has protective effects against ischemia-reperfusion injury(IRI), but its mechanism of action has not yet been determined. This study aims to investigate the protective effects and mechanism of AS-Ⅳ on H9c2 cardiomyocyte injury induced by hypoxia-reoxygenation(H/R). The H/R model of myocardial cells was established by hypoxic culture for 12 hours and then reoxygenation culture for 8 hours. After AS-Ⅳ treatment, cell viability, the reactive oxygen species(ROS) levels, as well as the content or activity of superoxide dismutase(SOD), malondialdehyde(MDA), interleukin 6(IL-6), and tumor necrosis factor alpha(TNF-α), were measured to evaluate the effect of AS-Ⅳ treatment. The effect of AS-Ⅳ on HO-1 protein expression and nuclear Nrf2 and Bach1 protein expression was determined by Western blot. Finally, siRNA was used to knock down HO-1 gene expression to observe its reversal effect on AS-Ⅳ intervention. The results showed that as compared with the H/R model group, the cell viability was significantly increased(P<0.01), ROS level in the cells, MDA, hs-CRP and TNF-α in cell supernatant and nuclear protein Bach1 expression in the cells were significantly decreased(P<0.01), while SOD content, HO-1 protein expression in cells and expression of nuclear protein Nrf2 were significantly increased(P<0.01) in H/R+AS-Ⅳ group. However, pre-transfection of HO-1 siRNA into H9c2 cells by liposome could partly reverse the above effects of AS-Ⅳ after knocking down the expression of HO-1. This study suggests that AS-Ⅳ has significant protective effect on H/R injury of H9c2 cardiomyocytes, and Nrf2/Bach1/HO-1 signaling pathway may be a key signaling pathway for the effect.
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Humans , Apoptosis , Basic-Leucine Zipper Transcription Factors , Metabolism , Cell Hypoxia , Cells, Cultured , Heme Oxygenase-1 , Metabolism , Myocytes, Cardiac , NF-E2-Related Factor 2 , Metabolism , Saponins , Pharmacology , Signal Transduction , Triterpenes , PharmacologyABSTRACT
OBJECTIVES@#To investigate the protective effects of Shexiang Tongxin Dropping Pill (, STP) on NaSO-induced hypoxia-reoxygenation injury in cardiomyoblast H9c2 cells.@*METHODS@#The cell viability and levels of mRNA and protein expression in H9c2 cells were determined following NaSO-induced hypoxia using Hoechst staining, annexin V/propidium iodide (PI) flow cytometry, real-time polymerase chain reaction and Western blot analysis.@*RESULTS@#STP pretreatment significantly increased the viability and inhibited aberrant morphological changes in H9c2 cardiomyoblast cells induced by NaSO treatment (P<0.05). In addition, STP pretreatment attenuated NaSO-induced hypoxic damage, down-regulated the expression of pro-apoptotic Bax, and up-regulated the expression of anti-apoptotic Bcl-2 in H9c2 cells (P<0.05).@*CONCLUSIONS@#STP was strongly cardioprotective in hypoxia-reoxygenation injury by preventing hypoxic damage and inhibiting cellular apoptosis. These results further support the use of STP as an effective drug for the treatment of ischemic heart disease.
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OBJECTIVE@#To investigate the effects of salvianolic acid A (SAA) on cardiomyocyte apoptosis and mitochondrial dysfunction in response to hypoxia/reoxygenation (H/R) injury and to determine whether the Akt signaling pathway might play a role.@*METHODS@#An in vitro model of H/R injury was used to study outcomes on primary cultured neonatal rat cardiomyocytes. The cardiomyocytes were treated with 12.5, 25, 50 μg/mL SAA at the beginning of hypoxia and reoxygenation, respectively. Adenosine triphospate (ATP) and reactive oxygen species (ROS) levels were assayed. Cell apoptosis was evaluated by flow cytometry and the expression of cleaved-caspase 3, Bax and Bcl-2 were detected by Western blotting. The effects of SAA on mitochondrial dysfunction were examined by determining the mitochondrial membrane potential (△Ψm) and mitochondrial permeability transition pore (mPTP), followed by the phosphorylation of Akt (p-Akt) and GSK-3β (p-GSK-3β), which were measured by Western blotting.@*RESULTS@#SAA significantly preserved ATP levels and reduced ROS production. Importantly, SAA markedly reduced the number of apoptotic cells and decreased cleaved-caspase 3 expression levels, while also reducing the ratio of Bax/Bcl-2. Furthermore, SAA prevented the loss of △Ψm and inhibited the activation of mPTP. Western blotting experiments further revealed that SAA significantly increased the expression of p-Akt and p-GSK-3β, and the increase in p-GSK-3β expression was attenuated after inhibition of the Akt signaling pathway with LY294002.@*CONCLUSION@#SAA has a protective effect on cardiomyocyte H/R injury; the underlying mechanism may be related to the preservation of mitochondrial function and the activation of the Akt/GSK-3β signaling pathway.
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Animals , Rats , Adenosine Triphosphate , Animals, Newborn , Caffeic Acids , Pharmacology , Cell Hypoxia , Cells, Cultured , Glycogen Synthase Kinase 3 beta , Physiology , Lactates , Pharmacology , Mitochondria, Heart , Physiology , Mitochondrial Membrane Transport Proteins , Myocytes, Cardiac , Proto-Oncogene Proteins c-akt , Physiology , Rats, Sprague-Dawley , Reactive Oxygen Species , Metabolism , Signal Transduction , PhysiologyABSTRACT
Ischemic cerebrovascular disease and cerebral ischemia/reperfusion injury threaten the health of human being. We studied the protective effect of Ginkgo biloba extract 50 (EGb50) on the mitochondrial function in SH-SY5Y cells after hypoxia/reoxygenation (H/R) injury and explored its mechanisms, so as to provide new ideas for studies on the treatment for ischemic cerebrovascular disease. We established the H/R injury model in SH-SY5Y cells after administrating EGb50. Subsequently, the mitochondrial membrane potential and the concentration of intracellular Ca²⁺ were measured by flow cytometer. The levels of optic atrophy1 (Opa1) and dynamin-like protein 1 (Drp1) were evaluated by immunofluorescence and western blot. The results showed that the mitochondrial membrane potential was decreased and the level of intracellular Ca²⁺ was increased after H/R injury. Moreover, the expression of mitochondrial fusion protein Opa1 was decreased, while the expression of mitochondrial fission protein Drp1 was increased. However, EGb50 significantly increased the mitochondrial membrane potential and suppressed the level of intracellular Ca²⁺. In addition, EGb50 increased the expression of Opa1 and decreased the expression of Drp1. The results demonstrated that EGb50 has a neuroprotective effect on SH-SY5Y cells after H/R injury, and could improve the energy metabolism and mitochondrial function. The underlying mechanisms may be associated with the regulation of mitochondrial fusion and fission, which provided data support for the treatment of ischemic cerebrovascular disease with EGb50.
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Humans , Cell Hypoxia , Membrane Potential, Mitochondrial , Mitochondria , Plant Extracts , Reperfusion InjuryABSTRACT
OBJECTIVE In this study we explored the role of Epac1-Rap1 pathway in the acute myocardial ischemia/reperfusion injury (MIRI) in vitro and in vivo. METHODS An acute myocardial ischemia/reperfusion injury model was established by the ligation of left anterior descending coronary. Myocardial architecture, fibers and apoptosis was evaluated by the Masson trichrome staining, Sirius red staining and TUNEL assay.H9c2 cells were subjected to hypoxia for 5 h followed by 1-h reoxygen-ation in vitro.Cell viability was measured by MTT assay and cellular injury was evaluated by measuring the release of lactate dehydrogenase (LDH). Western blot, real-time PCR and immunofluorescence were used to detect the expressions of Epac1 and relative downstream molecules.RESULTS Myocardial IR-induced cardiac apoptosis and accumulation of Epac1 and Rap1 in rat IR injury model.Direct Epac activation by 8-CPT(8-(4-chlorophenylthio)-2′-O-methyl-cAMP)exacerbated cardiomyocyte death and dysfunction following hypoxia-reoxygenation(H/R),selective activation of Epac in response to H/R was evident which enriched for cytosolic/membrane proteins and mRNA. Harmacological inhibitor of Epac (ESI-09)significantly ameliorated myocardial injury with the decline of Epac expression.Epac inhibitor and agonist studies also implicated the effect of Rap1, which is downstream of Epac in this pathway. The expression of Rap1 elevated when activated by Epac agonist and was blocked by Epac inhibitor. The same result was true for myocyte CaMK-II and intracellular calcium ions activation.Moreover,ESI-09 also increased ERK1/2 phosphorylation. CONCLUSION Our study reveal that Epac1/Rap1 signaling pathway is involved in the pathogenesis of myocardial I/R injury in rats,which provides evidence on the development of therapeutic strategies target this pathway for myocardial I/R injury.
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OBJECTIVES@#To investigate the effects of dexmedetomidine (Dex) on injury of A549 cells induced by hypoxia/reoxygenation(H/R)and the influence of C/EBP homologous protein (CHOP) expression.@*METHODS@#Logarithmic growth phase A549 cells(it originated from alveolar type Ⅱ epithelial cell line) were randomly divided into 4 groups (=10):normoxic control group (N), Dex group (D), hypoxia/reoxygenation group (H), hypoxia/reoxygenation + Dex group(HD). At the beginning of modeling, 1 nmol/L Dex was puted into D and HD groups. N and D groups were cultured in the normoxic incubator for 30 h. H and HD group were incubated in the anoxic cultivation for 6 h, fo llowed by normoxic culture for 24 h. Then A549 cells were observed under the inverted microscope to observe the morphological changes. Cell activity was detected by cell counting Kit-8(CCK-8) and the apoptosis index(AI) was detected by in situ end labeling (TUNEL) method. The expression of CHOP、glucose-regulated protein of molecular weight 78 kDa (Grp78)、cysteinyl aspirate-specificprotease-3 (caspase-3) protein and CHOP、Grp78 mRNA were detected by Western blot and RT-PCR.@*RESULTS@#Compared with N group, the number of adherent cells in H group decreased significantly, and cell morphology changed. The absorbance value in H group decreased obviously (<0. 01). The AI value and expression of CHOP, Grp78, caspase-3 proteins and CHOP, Grp78 mRNA were significantly increased (<0.01). Compared with H group, the cell damage in HD group was decreased, the absorbance value increased (<0.01), the number of apoptosis cells decreased relatively (<0.01), the expression of CHOP, caspase-3 protein and CHOP mRNA decreased (<0. 01).@*CONCLUSIONS@#Dex has notable effects against H/R injury, which may be related to effective inhibition of apoptosis mediated by the CHOP's signal path.
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Humans , A549 Cells , Apoptosis , Cell Hypoxia , Dexmedetomidine , Pharmacology , Transcription Factor CHOP , PhysiologyABSTRACT
Aim To observe the protective effect of epigallocatechin-3-gallate (EGCG) on hypoxia/reoxygenation (H/R) injury of cardiac myocytes and its mechanisms.Methods H9c2 cardiac myocytes were cultured in vitro and randomly divided into five groups:normal group(N group),H/R group,EGCG low dose group (L group),EGCG medium dose group (M group),and EGCG high dose group(H group).The cardiomyocyte H/R injury model was established and EGCG was pretreated.Cell survival rate was tested by CCK-8 method.The cell apoptotic rate was detected using Annexin V-FITC/PI double staining.The contents of total antioxidant capacity(T-AOC) and tumor necrosis factor α(TNF-α) in cell culture medium were tested according to the kit instructions.The protein expression of Akt and p-Akt was observed using Western blot,while the gene expressions of PI3K,Akt,caspase3 were detected by using fluorescence quantitative PCR method.Results Compared with model group,EGCG increased cell survival rate and reduced the apoptosis after H/R injury.Meanwhile,pretreatment EGCG improved the activity of T-AOC,reduced the level of TNF-α,up-regulated the expression of PI3K,Akt and p-Akt,and down-regulated the expression of caspase3.Conclusion EGCG reduces apoptosis and protects cardiac myocytes by influencing PI3K/Akt signal path
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Objective: To study the protective effects and the mechanism of Salvia yunnanensis extract on hypoxia/reoxygenation injury in cultured rat H9c2 cardiomyocytes.Methods: The hypoxia/reoxygen (H/R) injury model was established in H9c2 cell strain with or without the extract of Salvia yunnanensis.The cultured H9c2 cardiomyocytes were randomly divided into 6 groups: the normal control (C) group, H/R group, H/R+verapamil (H/R+V) group, H/R+Salvia yunnanensis extract at low dose (H/R+L, 0.01 mg·L-1) group, medium dose (H/R+M, 0.1 mg·L-1) group and high dose (H/R+H, 1.0 mg·L-1) group.The cell viability was measured by MTT assay and the activity of malondialdehyde (MDA) and lactate dehydrogenase (LDH) was measured by a detection kit.Fluorescence absorbance (A) value was measured by a fluoroscopy to show the intracellular reactive oxygen species (ROS) levels.Results: Compared with that in the model group, the survival rate of myocardial cells was significantly higher in Salvia yunnanensis extract at low, medium and high dose groups (P＜0.05 or P＜0.01), and the intracellular LDH leakage (P＜0.05 or P＜0.01), the content of MDA in cytoplasm (P＜0.01) and the intracellular ROS levels significantly decreased in Salvia yunnanensis extract at high dose group (P＜0.05).Conclusion: The extract of Salvia yunnanensis has protective effect on hypoxia/reoxygenation injury in cultured rat H9c2 cardiomyocytes, and the mechanism may be related to the reduction of lipid peroxides and removal of cell oxygen free radicals.
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AIM:To investigate the effects and c-Jun N-terminal kinase(JNK) expression of dexmedetomidine (DEX) on A549 cells with hypoxia/reoxygenation (H/R) injury.METHODS:A549 cells were cultivated and were randomly divided into four groups (n =10):control group (N),DEX group (D),hypoxia/reoxygenation injury group (H),hypoxia/reoxygenation injury + DEX interfere group (HD).After all models were completed,the morphological changes of A549 cells were observed under the inverted microscope.Cell activity was detected by CCK-8 and the apoptosis index (AI) was detected by in situ end labeling (TUNEL) method.The expression of GRP78,p-JNK,caspase-3 at protein levels and GRP78,JNK mRNA were detected by Western blot and RT-PCR.RESULTS:Compared with N group,the number of adherent cells in H group decreased significantly,and cell morphology changed.The expression of OD value in H group decreased obviously (P ＜ 0.01),the expression of AI value,GRP78,p-JNK,caspase-3 protein and GRP78,JNK mRNA were significantly increased (P＜ 0.01).HD group compared with H group,the cell damage alleviated,the expression of OD value was increased (P ＜ 0.01),the number of apoptosis cells and the AI value in HD group were significantly decreased (P ＜ 0.01).Dramatically decreased the expression of p-JNK,caspase-3 protein and JNK mRNA (P ＜ 0.01).CONCLUSION:DEX can effectively alleviate A549 cells damage induced by H/R injury,which may be related to inhibition of the JNK pathway.