Cytoprotective effect of rhamnetin on miconazole-induced H9c2 cell damage

BACKGROUND/OBJECTIVES: Reactive oxygen species (ROS) formation is closely related to miconazole-induced heart dysfunction. Although rhamnetin has antioxidant effects, it remained unknown whether it can protect against miconazole-induced cardiomyocyte apoptosis. Thus, we investigated the effects of rhamnetin on miconazole-stimulated H9c2 cell apoptosis. MATERIALS/METHODS: Cell morphology was observed by inverted microscope and cell viability was determined using a WelCount(TM) cell proliferation assay kit. Miconazole-induced ROS production was evaluated by fluorescence-activated cell sorting with 6-carboxy-2',7'-dichlorofluoroscein diacetate (H2DCF-DA) stain. Immunoblot analysis was used to determine apurinic/apyrimidinic endonuclease 1 (APE/Ref-1) and cleaved cysteine-aspartic protease (caspase) 3 expression. NADPH oxidase levels were measured using real-time polymerase chain reaction. RESULTS: Miconazole (3 and 10 microM) induced abnormal morphological changes and cell death in H9c2 cells. Rhamnetin enhanced the viability of miconazole (3 microM)-treated cells in a dose-dependent manner. Rhamnetin (1 and 3 microM) treatment downregulated cleaved caspase 3 and upregulated APE/Ref-1 expression in miconazole-stimulated cells. Additionally, rhamnetin significantly reduced ROS generation. CONCLUSIONS: Our data suggest that rhamnetin may have cytoprotective effects in miconazole-stimulated H9c2 cardiomyocytes via ROS inhibition. This effect most likely occurs through the upregulation of APE/Ref-1 and attenuation of hydrogen peroxide levels.

Construction of thioredoxin-DsRed and APE/ref-1-EGFP fusion protein vectors and their localization in 293T cells / 基础医学与临床

Objective To construct thioredoxin and APE/ref-1 fusion protein expression vector and to investigate their subcellular localization of the fusion proteins in 293Tcells.Methods The APE/ref-1 cDNA was cloned by RT-PCR from PC12 cell.APE/ref-1-EGFP fusion protein expression vector was constructed through subcloning.Thioredoxin cDNA was subcloned into pDSred1-1 from pQE30-TRX plasmid by PCR,and thioredoxin-DsRed fusion protein expression vector was constructed in pCMV5 plasmid.The expression and subcellular localization of the fusion proteins in 293T cells transfected with the vectors by calcium phosphate was analyzed by fluorescent microscopy.Results The results demonstrated that thioredoxin——DsRed and APE/ref-1-EGFP fusion protein expression vectors were successfully constructed and expressed in 293T cells.APE/ref-1-EGFP fusion protein was located only in nucleus,and thioredoxin-DsRed fusion protein was located in cytoplasm as well as nucleus.ConclusionThis study has set up a solid base for further to study on the dynamic interaction between thioredoxin and APE/ref-1 fusion proteins.

APE/Ref-1 protein and ischemia/reperfusion injury of neurons in the brain / 中国病理生理杂志

Cerebral ischemia and the aftermath of reperfusion form a hypoxic/hyperoxic sequence of events that can trigger DNA damage in neurons of central nervous system. Neuronal apoptosis will happen without immediate DNA repair. APE/Ref-1 is a multifunctional protein involoved in DNA base excision repair pathway and in redox reguiation of DNA-binding activity of AP-1 family members, which may play an important role in protection of postischemic neuronal damage.