Liraglutide ameliorates high glucose-induced oxidative stress injury in rat H9c2 cells through modulation of SIRT1 / 中华内分泌代谢杂志

Objective:To investigate the effect of liraglutide(LRG) on high glucose-induced oxidative stress injury in(H9c2) cardiomyocytes and its underlying mechanisms.Methods:A high glucose treatment was applied to H9c2 cells for 24 hours to establish an in vitro model of myocardial cell injury. Different concentrations of liraglutide(10, 100, 1000 nmol/L) were administered for intervention. Cell viability was evaluated using the CCK-8 assay, and changes in cell morphology were observed under an inverted microscope. After 24 hours of liraglutide(100 nmol/L) intervention following high glucose treatment, the levels of lactate dehydrogenase(LDH), superoxide dismutase(SOD), and malondialdehyde(MDA) in the cell supernatant were measured. RT-PCR and Western blotting were used to detect the mRNA and protein levels of silent information regulator factor 1(SIRT1) and forkhead box protein O1(FOXO1). Western blotting was also used to assess the acetylation level of FOXO1 protein. Small interfering RNA(siRNA) technology was employed to silence SIRT1 in H9c2 cells to confirm its role in the study. Results:Compared to the control group, the high glucose group showed decreased cell viability, cell structure damage, increased levels of LDH and MDA in the cell supernatant, decreased SOD levels, aggravated oxidative stress, decreased SIRT1 expression, and increased acetylation level of FOXO1(all P<0.05). Compared to the high glucose group, liraglutide intervention resulted in increased cell viability, improved cardiac cell morphology, reduced oxidative stress levels, increased SIRT1 expression, and decreased acetylation level of FOXO1(all P<0.05). When SIRT1 was downregulated, the protective effects of liraglutide were weakened(all P<0.05). Conclusions:Liraglutide has a protective effect against high glucose-induced oxidative stress injury in H9c2 cells, which may be associated with the upregulation of SIRT1 expression.

Study on protective effects of methyl ferulate on mitochondria of H 9c2 cardiomyocytes injured by hypoxia / 中国药房

OBJECTIVE To investigate the e ffects of methyl ferulate （MF） on the mitochondrial function of H 9c2 cardiomyocytes after hypoxia-induced injury. METHODS H9c2 cardiomyocytes were divided into normal group （no administration，no modeling ），hypoxia model group （modeling alone ），MF high-dose ，medium-dose and low-dose groups （40， 20，10 μmol/L）and positive control drug group （cyclosporin A ，1 μmol/L）. After drug pretreatment and inducing hypoxia-induced injury，the levels of lactate dehydrogenase （LDH），malondialdehyde（MDA），creatine kinase （CK）and adenosine triphosphate （ATP）were tested. The intracellular reactive oxygen species （ROS），mitochondrial membrane potential （MMP），the opening of mitochondrial membrane permeability transition pore （mPTP） were detected with flow cytometry. RESULTS Compared with hypoxia model group ，the levels of LDH ，MDA，CK and ROS fluorescence intensity were decreased significantly in MF high-dose，medium-dose and low-dose groups ，while the level of ATP was increased significantly （P＜0.01 or P＜0.05）. The red/ green fluorescence intensity ratio of MMP and the green fluorescence intensity of mPTP were increased significantly （P＜0.01 or P＜0.05）. CONCLUSIONS MF can reverse the levels of biochemical indexes in H 9c2 cardiomyocyte after hypoxia-induced injury，keep MMP stable ，reduce the opening of mPTP ，and has an obvious protective effect on the mitochondrial function of H9c2 cardiomyocytes injured by hypoxia ，and this protective effect is dose-dependent.

Mechanism of Aconiti Kusnezoffii Radix Processed with Chebulae Fructus Against H9c2 Cardiomyocyte Toxicity Based on TRPV1 Channel / 中国实验方剂学杂志

ObjectiveTo explore the role of transient receptor potential vanilloid 1 （TRPV1） channel in reducing cardiomyocyte toxicity of Aconiti Kusnezoffii Radix processed with Chebulae Fructus. MethodH9c2 cardiomyocytes cultured in vitro were used as a model to assess cell viability by methyl thiazolyl tetrazolium （MTT） assay， the expression of TRPV1 mRNA was detected by real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）， and the leakage rate of lactate dehydrogenase （LDH）， the changes of nucleus， reactive oxygen species （ROS）， mitochondrial membrane potential and Ca2+ contents were detected by enzyme linked immunosorbent assay （ELISA）. ResultCompared with the blank group， when the concentration was ≥0.5 g·L-1， the cell viability was significantly decreased （P<0.01）， the leakage rate of LDH， the release of ROS and Ca2+ were increased， the mitochondrial membrane potential was decreased， and the nucleus was pyknosis or even broken in raw Aconiti Kusnezoffii Radix and Aconiti Kusnezoffii Radix processed with Chebulae Fructus groups. When the concentration was ≥0.5 g·L-1， compared with the same mass concentration of raw Aconiti Kusnezoffii Radix group， the cell viability increased significantly （P<0.01）， the leakage rate of LDH， the release of ROS and Ca2+ decreased， the mitochondrial membrane potential increased， and the nuclear morphology improved in Aconiti Kusnezoffii Radix processed with Chebulae Fructus group. Application of the same mass concentration of raw Aconiti Kusnezoffii Radix to H9c2 cardiomyocytes pretreated with the TRPV1 inhibitor BCTC significantly increased cell viability， decreased leakage rate of LDH， ROS and Ca2+ release， increased mitochondrial membrane potential and improved nuclear pyknosis compared with untreated H9c2 cardiomyocytes. Application of the same mass concentration of Aconiti Kusnezoffii Radix processed with Chebulae Fructus to H9c2 cardiomyocytes pretreated with BCTC decreased cell viability， increased LDH leakage rate， ROS and Ca2+ release， reduced mitochondrial membrane potential compared with untreated H9c2 cardiomyocytes. Real-time PCR results showed that both raw Aconiti Kusnezoffii Radix and Chebulae Fructus decoction could increase the expression of TRPV1 mRNA in cardiomyocytes in a concentration dependent manner. ConclusionRaw Aconiti Kusnezoffii Radix can induce cardiomyocyte apoptosis and cardiotoxicity by activating TRPV1 channel， while Aconiti Kusnezoffii Radix processed with Chebulae Fructus can attenuate the toxicity through TRPV1 channel， which may be related to the synergistic effect of acid components in Chebulae Fructus and alkaloids in Aconiti Kusnezoffii Radix on TRPV1 channel.

Study on Improvement Effects of Polygonum orientale Flower Extract on Hypoxia-reoxygenation Injury of H 9c2 Cardiomyocytes / 中国药房

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.

Salvianolic acid B regulates mitochondrial autophagy mediated by NIX to protect H9c2 cardiomyocytes from hypoxia/reoxygenation injury / 中国中药杂志

The aim of this paper was to investigate whether the mechanism of salvianolic acid B in protecting H9 c2 cardiomyocytes from hypoxia/reoxygenation injury is related to the regulation of mitochondrial autophagy mediated by NIX. H9 c2 cardiomyocytes were cultured in vitro and divided into normal group, model group and salvianolic acid B group(50 μmol·L~(-1)). Hypoxia/reoxygenation injury model was established by hypoxia for 4 h and reoxygenation for 2 h. In normal group, high glucose DMEM medium was used for culture. Those in model group were cultured with DMEM medium without glucose and oxygen, and no drugs for hypoxia and reoxyge-nation. In salvianolic acid B group, salvianolic acid B prepared by glucose-free DMEM medium was added during hypoxia, and the other process was as same as the model group. The cell viability was evaluated by CCK-8 assay. The leakage of lactate dehydrogenase(LDH) was detected by microplate method. The levels of intracellular reactive oxygen species(ROS) and mitochondrial membrane potential(ΔΨm) were measured by chemical fluorescence method. The level of intracellular adenosine triphosphate(ATP) was mea-sured by fluorescein enzyme method. The autophagy related proteins LC3-Ⅰ, LC3-Ⅱ, apoptosis related protein cleaved caspase-3 and mitochondrial autophagy receptor protein NIX were detected by Western blot. As compared with the normal group, the activity of H9 c2 cardiomyocytes and ATP level were decreased(P<0.05); LDH leakage and ROS production were increased(P<0.01); ΔΨm was decreased(P<0.01); LC3-Ⅱ/LC3-Ⅰ ratio, cleaved caspase-3 and NIX protein expression levels were increased(all P<0.05) in the model group. As compared with the model group, the activity of cells and ΔΨm were significantly increased(P<0.01); ATP level was increased(P<0.05); LDH leakage and ROS generation were decreased(P<0.01); LC3-Ⅱ/LC3-Ⅰ ratio was decreased(P<0.01); cleaved caspase-3 and NIX expression levels were decreased(P<0.05) in the salvianolic acid B group. The protective effect of salvianolic acid B on hypoxia/reoxygenation injury of H9 c2 cardiomyocytes may be associated with inhibiting mitochondrial auto-phagy. The specific mechanism may be related to inhibiting the activation of mitochondrial autophagy mediated by NIX, increasing ΔΨm, reducing ROS production, reducing the expression of cleaved caspase-3, LC3-Ⅱ, and increasing cell viability.

Effect of Picroside Ⅱ on Expression of microRNA-1 in H2O2-induced H9c2 Cardiomyocytes Damage / 中国实验方剂学杂志

Objective: To study the effect of picroside Ⅱ on the expression of microRNA-1 (miR-1) in the H2O2-induced H9c2 cardiomyocytes damage, in order to explore the mechanism of picroside Ⅱ in protecting H9c2 cardiomyocytes from oxidative stress. Method: H9c2 cardiomyocytes were divided into 6 groups:control group, model group (H2O2 200 μmol·L-1), picroside Ⅱ (50, 100, 200 μmol·L-1)+H2O2 (200 μmol·L-1) group and picroside Ⅱ (200 μmol·L-1) group. Picroside Ⅱ group was incubated with picroside Ⅱ for 6 h and then cultured with H2O2 for 2 h. At the end of drugs treatment, the cell viability and the cellular damage of cardiomyocytes were respectively assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays. 4',6-diamidino-2-phenylindole (DAPI) staining and cysteinyl aspartate specific proteinase-3 (Caspase-3) test were used to evaluate cell apoptosis. The mRNA expressions of Caspase-3,B-cell lymphoma-2 (Bcl-2) and miR-1 were measured by Real-time polymerase chain reaction (Real-time PCR). The protein expression of Bcl-2 was detected by Western blot. Result:Compared with the control group, H2O2 could significantly decrease the cell viability and increase the rate of apoptosis, up-regulate mRNA expression of Caspase-3 and miR-1, and down-regulate expression of Bcl-2 in H9c2 cells (PPPPPPPConclusion:Picroside Ⅱ has a protective effect on H9c2 cells from H2O2-induced cardiomyocyte injury by down-regulating mRNA-1 expression and up-regulating the expression of the downstream Bcl-2.

Protective effect of luteolin-7-O-β-D-glucuronide against oxygenglucose deprivation-induced H9C2 cardiomyocytes injury / 中国药理学与毒理学杂志

OBJECTIVE To investigate the protective effect and mechanisms of luteolin-7-O-β-d-glucuronide (LGU) on oxygen glucose deprivation (OGD)-induced H9C2 cardiomyocytes injury. METH-ODS The protective effect of LGU on OGD-induced H9C2 cardiomyocytes death were investigated by MTT assay. The microfilament change of H9C2 cardiomyocytes was detected by phalloidin staining and the lactate dehydrogenase (LDH) leakage rate was also detected by LDH kit. In order to explore the possible mechanisms of LGU, ATP content, intracellular Ca2+fluorescent intensity and concentra-tion, mitochondrial membrane potential (MMP)and the expressions of apoptosis-related proteins were detected by ATP kit,CLSM(Fluo-3/AM probe),Ca2+kit,CLSM(JC-1 probe)and western blotting meth-od, respectively. RESULTS The inhibition of H9C2 cardiomyocyte survival rate inducedby OGD was improvedby pretreated with LGU in a concentrationdependent manner. The microfilaments injury as well as the increase of LDH leakage rate were also improvedby pretreated with LGU.The ATP content was significantly decreased,intracellular Ca2+fluorescent intensity and concentration were significantly increased and the MMP was significantly decreased 4 hafter OGD. LGU significantly reversed the de-crease of intracellular ATP content,the increase of Ca2+fluorescent intensity and concentration and the decrease of MMP.The release of cytochrome C,the expressionsof caspase-9 and caspase-3 in H9C2 cardiomyocytes were increased 16 h after OGD.LGUsignificantly inhibited the changes of these apop-tosis-related proteins. CONCLUSION LGU has a significant protective effect against OGD-induced H9C2 cardiomyocytes injury through inhibiting calcium overload,increasing ATP content,improving mi-tochondrial function and inhibiting apoptosis.

Protective Effects of Salvia Yunnanensis Extract on Hypoxia/Reoxygenation Injury in Cultured Rat H9c2 Cardiomyocytes / 中国药师

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.

Study on apoptosis mechanism of H9c2 cardiomyocytes induced by N, N-dimethylformamide / 中华劳动卫生职业病杂志

Objective@#To observe the change levels of nuclear factor-kappa B (NF-κB) p65 protein in cytoplasm and nuclear, phosphorylation of inhibitor of kappa B (p-IκB) protein and cytochrome C (Cyt-c) , cleaved cysteinyl aspartate specific proteinase-3 (Cleaved caspase-3) , B-cell lymphoma/leukemia-2 (Bcl-2) in cytoplasm in the process of N, N-dimethylformamide (DMF) -induced apoptosis in H9c2 cardiomyocytes, and explore the tentative mechanism of apoptosis.@*Methods@#H9c2 cardiomyocytes were exposed to 200 mmol/L DMF. Western blotting was used to detect the protein expression levels of p65 in cytoplasm and nuclear, p-IκB after exposure for 0, 2, 4, 6, 8, 12 h, and the protein expression levels of Cyt-c, Cleaved caspase-3, Bcl-2 in cytoplasm after exposure for 0, 2, 4, 8, 12, 24 h. Immunofluorescencecytochemistry (IFC) was used to observe the location of Cyt-c after 200 mmol/L DMF exposure for different times.@*Results@#The levels of p65 in cytoplasm and nuclear and p-IκB among groups were statistically significant (F were 7.79, 33.11, 90.25, respectively, all P<0.01) . Compared with the control group, the levels of p65 in cytoplasm of 2, 4, 6 h group were significantly decreased (all P<0.01) ; the levels of p65 in nuclear of 2, 4, 6, 8 h were significantly increased (all P<0.01) ; the levels of p-IκB of 2, 4, 6 h group were significantly increased (all P<0.01) . The levels of Cyt-c, Cleaved caspase-3 and Bcl-2 among groups were statistically significant (F were 51.42, 503.68, 73.37, respectively, all P<0.01) . Compared with the control group, the levels of Cyt-c of 8, 12 h group were significantly increased (both P<0.01) ; the levels of Cleaved caspase-3 of 2, 4, 8, 12, 24 h were significantly increased (all P<0.01) ; the levels of Bcl-2 of 2, 4, 8, 12, 24 h group were significantly decreased (all P<0.01) . IFC showed that Cyt-c was released from the mitochondria to the cytoplasm gradually as the extension of the exposure time.@*Conclusion@#NF-κB signaling pathway and mitochondrial pathway are involved in the mechanism of DMF-induced apoptosis in H9c2 cardiomyocytes.

Protective effect of GLP-1 against AGEs-induced H9 C2 myocardial cell apoptosis / 中国药理学通报

Aim To investigate the protective effect of Glucogon like pep tide-1 (GLP-1 )on H9C2 cardio-myocytes against AGEs-induced apoptosis and the po-tential molecular mechanisms.Methods H9 C2 car-diomyocytes cells cultured in vitro were divided into the following groups:normal control group ,1 0 0 mg · L-1 AGEs group,100 mg·L-1 AGEs+10 nmol·L-1 GLP-1 group,100 mg·L-1 AGEs+5 mmol·L-1 N-acetyl-cysteine (NAC)group.Cell viabillity rate was meas-ured by CCK-8 assay,ROS production was measured by DCFH-DA fluorescent probe;Cells in different groups were stained with Annexin V-FITC/PI and then apoptotic rate was detected by flow cytometry;Nucleus morphology was observed under fluorescence micro-scope after being incubated with Honchest 33258;Bax, Bcl-2 mRNA gene expression was measured using RT-PCR;Western blot was applied to assess the apoptotic components expression including Bax and Bcl-2.Re-sult Compared with control group,cell viability rate in AGEs group was decreased in a dose-dependent manner;cell apoptosis and ROS production in H9 C2 cells were remarkably increased in AGEs group.How-ever,compared with AGEs group,GLP-1 reduced ROS production and ameliorated cell apoptosis caused by AGEs;the expression of pro-apototic proteins Bax was decreased,the expression of anti-apoptotic proteins like Bcl-2 was increased. Conclusion GLP-1 protects H9 C2 cardiomyocytes against AGEs-induced apoptosis, which may be related to the reduction of the active oxy-gen (ROS).

Research on the inflammatory injury induced by N,N-dimethylformamide in H9c2 cardiomyocytes / 中国职业医学

OBJECTIVE: To explore the effect of N,N-dimethylformamide( DMF)-induced inflammatory injury in H9c2 cardiomyocytes and its mechanism. METHODS: H9c2 cardiomyocytes were cultured in vitro and randomly divided into 4different groups: control group,50 mmol / L-group,100 mmol / L-group,200 mmol / L-group. These 4 groups of cells were treated with different DMF concentrations( 0,50,100,200 mmol / L) for 12 hours. The cells were also divided into 6groups and treated with 200 mmol / L DMF at different time points( 0,2,4,6,8,12 h) : control group,2 h-group,4 hgroup,6 h-group,8 h-group and 12 h-group. The level of lactate dehydrogenase( LDH) was detected by colorimetry. The levels of creatine kinase( CK) and isoenzyme of creatine kinase( CK-MB) were detected by ultraviolet spectrometry. The levels of tumor necrosis factor-α( TNF-α),interleukin( IL)-1β,IL-6,and IL-8 were detected by enzyme linked immunosorbent assay. The level of reactive oxygen species( ROS) was detected by fluorescence probe. The location of nuclear factor-kappa B( NF-κB) p65 protein was detected by immunofluorescence cytochemistry( IFC) staining. RESULTS: The levels of LDH,CK and CK-MB in the 50 mmol / L-group,100 mmol / L-group and 200 mmol / L-group were higher than that of the control group( P < 0. 05) and showed a significant dose-effect( P < 0. 05). The levels of LDH,CK and CK-MB in the 6 h-group,8 h-group and 12 h-group were higher than that of the control group( P < 0. 01) and showed a significant time-effect( P < 0. 01). The levels of TNF-α,IL-1β,IL-6 and IL-8 of the 200 mmol / L-group were higher than the control group( P < 0. 05). Compared with the control group,the levels of TNF-α of the 4 h-group,12 h-group were higher( P < 0. 05),the levels of IL-1β of the 2 h-group,4 h-group,6 h-group,8 h-group and 12 h-group were higher( P < 0. 05),the levels of IL-6 of the 2 h-group and 4 h-group were higher( P < 0. 05),the level of IL-8 of the 2 h-group was higher( P < 0. 05). In addition,the levels of TNF-α,IL-1β and IL-6 reached a peak at 4 h-group and the level of IL-8 reached a peak at 2 h-group. The ROS levels of the 2 h-group,4 h-group and 6 h-group were higher than the control group( P < 0. 01),and the level of ROS reached a peak at 2 h-group. Furthermore,IFC staining showed that the fluorescence intensity of NF-κB p65 protein in nucleus of the 2h-group and 4 h-group increased after treatment with DMF,comparing with the control group. CONCLUSION: DMF leads to inflammatory injury in H9c2 cardiomyocytes. ROS and NF-κB might be involved in the process.

Astragaloside IV prevents lipopolysaccharide-induced injury in H9C2 cardiomyocytes / 中国天然药物

This study aimed to investigate the protective effects of astragaloside IV (AS IV) on lipopolysaccharide (LPS)-induced injury in H9C2 cardiomyocytes. H9C2 Cardiomyocytes were cultured with LPS (10 μg·mL(-1)) for 4 h and treated with AS IV at 50, 100, and 150 μmol·L(-1) for various durations. Cell viability was determined by MTT. The content of released TNF-α and IL-6 from cardiomyocytes were evaluated by enzyme-linked immunosorbent assay (ELISA). The levels of superoxidase dismutase (SOD), malondialdehyde (MDA), lactate dehydrogenase (LDH), and creatine phosphate kinase (CK) were measured by using commercial available kits. The mRNA and protein expression levels of NF-κB p65 were measured by RT-PCR and Western blotting, respectively. And the NF-κB p65 activity was measured by ELISA. Our results demonstrated that AS IV at 50, 100, and 150 μmol·L(-1) markedly inhibited the release of TNF-α and IL-6 and decreased NF-κB expression, compared with the model group. Moreover, the improved SOD activity and decreased MDA, LDH and CK levels were detected after AS IV treatment. In summary, AS IV could increase the activities of antioxidant enzymes, inhibite lipid peroxidation, and down-regulate the inflammatory mediators involved in the inflammatory responses. These results demonstrated that AS IV could prevent LPS-induced injury in cardiomyocytes.

EGCG Blocked Phenylephrin-Induced Hypertrophy in H9C2 Cardiomyocytes, by Activating AMPK-Dependent Pathway

AMP-activated protein kinase (AMPK) is a key regulator of energy metabolism. Previous studies have shown that activation of AMPK results in suppression of cardiac myocyte hypertrophy via inhibition of the p70S6 kinase (p70S6K) and eukaryotic elongation factor-2 (eEF2) signaling pathways. Epigallocatechin-3-gallate (EGCG), the major polyphenol found in green tea, possesses multiple protective effects on the cardiovascular system including cardiac hypertrophy. However, the molecular mechanisms has not been well investigated. In this study, we found that EGCG could significantly reduce natriuretic peptides type A (Nppa), brain natriuretic polypeptide (BNP) mRNA expression and decrease cell surface area in H9C2 cardiomyocytes stimulated with phenylephrine (PE). Moreover, we showed that AMPK is activated in H9C2 cardiomyocytes by EGCG, and AMPK-dependent pathway participates in the inhibitory effects of EGCG on cardiac hypertrophy. Taken together, our findings provide the first evidence that the effect of EGCG against cardiac hypertrophy may be attributed to its activation on AMPK-dependent signaling pathway, suggesting the therapeutic potential of EGCG on the prevention of cardiac remodeling in patients with pressure overload hypertrophy.

Efecto del ácido lipoteicoico sobre la expresión de genes en cardiomiocitos de ratón (H9c2) / Effect of lipoteichoic acid on gene expression in mice (H9c2) cardiomyocite

La mayoría de las enfermedades de la pulpa dental y de los tejidos perirradiculares guardan relación con microorganismos. Los peptidoglucanos y el ácido lipoteicoico son dos de los principales componentes de las bacterias Gram positivas que tienen actividades relacionadas con el desarrollo de sepsis. Tras la invasión microbiana de estos tejidos, el huésped responde con defensas tanto inflamatorias inespecíficas como inmunológicas específicas. El tratamiento endodóncico quirúrgico y no quirúrgico son en esencia, procedimientos de desbridamiento destinados a destruir y eliminar el ecosistema microbiano, asociado con el proceso patológico. Es importante que los clínicos comprendan la íntima relación entre presencia de microorganismos y enfermedad endodóncica, con el fin de diseñar un tratamiento racional y efectivo; sobre todo en aquellos individuos susceptibles a Endocarditis Infecciosa. En el presente estudio se investigó la expresión de TNFα, IL-1 y COX-2 por efecto del ácido lipoteicoico (ALT) de Streptococcus sanguinis caracterizando las señales intracelulares involucradas en cardiomiocitos H9c2. La línea celular fue tratada con ALT a diferentes concentraciones durante 30 minutos. Comparadas con los controles, las respuestas al tratamiento con ALT fueron dependientes de la dosis y mediante un análisis de One Step RT-PCR (Invitrogen) se evaluó dicha expresión; la cual se asemeja a la respuesta fisiológica del organismo durante un episodio de Endocarditis infecciosa y a la agudización durante un procedimiento endodóncico.

Most dental pulp diseases and diseases of tissues surrounding the root are somehow related to micro-organisms. Peptidoglycans and lipoteichoic acid are two of the main Gram-positive bacteria components with activities related to sepsis development. When tissues sustain microbial invasion the host responds with both unspecific inflammatory defenses and specific immunological reactions. Surgical and non surgical endodontic treatments are essentially debridement procedures intended to destroy and eliminate the microbial eco-system associated to the pathological process. It is essential for clinicians to understand the intimate relationship existing between micro-organisms and endodontic disease, so as to be able to tailor a rational and effective treatment especially in subjects susceptible to infective endocarditis processes. In the present study research was conducted on TNFα, IL-1 COX-2 expression through the effect of lipoteichoic acid (LTA) of Streptococcus sanguinis by characterizing intra-cellular signals involved in H9c'' cardiomyocytes. The cell line was treated with LTA at different concentrations during 30 minutes. When compared to control group, responses to LTA treatment were dependent on dosage. That expression was assessed by means of a One Step RT-PCR (Invitrogen) analysis. It was noted that the aforementioned expression resembled the organisms's physiological response during an infective endocarditis episode and to exacerbation observed during an endodontic procedure.