Role of reactive oxygen species in hypoxia postconditioning-induced activation of Nrf2/ARE signaling pathway in rat cardiomyocytes / 中华麻醉学杂志

Objective:To evaluate the role of reactive oxygen species (ROS) in hypoxia postconditioning-induced activation of nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling pathway in rat cardiomyocytes.Methods:Primary cardiomyocytes of adult rats were isolated and cultured and divided into 4 groups ( n=20 each) using a random number table method: normal group (group N), hypoxia-reoxygenation group (group HR), hypoxia postconditioning group (group HPO) and hypoxia postconditioning plus an ROS scavenger N-(2-Amidinopropionyl)-glycine (MPG) group (group HPO+ MPG). Cells were exposed to hypoxia for 45 min followed by 60 min reoxygenation to develop the cardiomyocyte hypoxia-reoxygenation injury model.In HPO group, cells were subjected to 3 cycles of 5-min hypoxia/5-min reoxygenation after 45 min hypoxia, followed by reoxygenation for 60 min.In HPO+ MPG group, MPG (final concentration 2 mmol/L) was added at 35 min of hypoxia, cells were subjected to hypoxia for 10 min, and the other treatments were similar to those previously described in group HPO.At the end of reoxygenation, the intracellular calcium level and Nrf2 activity were measured, the ultrastructure of cardiomyocytes was observed, and the Flameng score of mitochondria was assessed, and the expression of Nrf2, NAD(P)H quinine oxidoreductase 1 (NQO1), superoxide dismutase 1 (SOD1) and heme oxygenase-1 (HO-1) protein and mRNA was detected using real-time polymerase chain reaction and Western blot. Results:Compared with group N, the intracellular free Ca 2+ level, Nrf2 activity and Flameng score were significantly increased, and the expression of Nrf2, NQO1, SOD1 and HO-1 protein and mRNA was down-regulated in group HR ( P<0.05). Compared with group HR, the intracellular free Ca 2+ level and Flameng score were significantly decreased, the Nrf2 activity was increased, and the expression of Nrf2, NQO1, SOD1 and HO-1 protein and mRNA was up-regulated in group HPO ( P<0.05). Compared with group HPO, the intracellular free Ca 2+ level and Flameng score were significantly increased, the Nrf2 activity was decreased, and the expression of Nrf2, NQO1, SOD1 and HO-1 protein and mRNA was down-regulated in group HPO+ MPG ( P<0.05). Conclusions:The mechanism by which hypoxia postconditioning activates the Nrf2/ARE signaling pathway in rat cardiomyocytes may be related to ROS.

Genomic organization of Polycomb Response Elements and its functional implication in Drosophila and other insects

The epigenetic memory is an essential aspect of multicellular organisms to maintain several cell types and their geneexpression pattern. This complex process uses a number of protein factors and specific DNA elements within thedevelopmental cues to achieve this. The protein factors involved in the process are the Polycomb group (PcG)members, and, accordingly, the DNA sequences that interact with these proteins are called Polycomb ResponseElements (PREs). Since the PcG proteins are highly conserved among higher eukaryotes, including insects, andfunction at thousands of sites in the genomes, it is expected that PREs may also be present across the genome. However,the studies on PREs in insect species, other thanDrosophila, is currently lacking.We took a bioinformatics approach todevelop an inclusive PRE prediction tool, ‘PRE Mapper’, to address this need. By applying this tool on the Drosophilamelanogaster genome, we predicted[20,000 PREs. When compared with the available PRE prediction methods, thistool shows far better performance by correctly identifying the in vivo binding sites of PcG proteins, identified bygenome-scale ChIP experiments. Further analysis of the predicted PREs shows their cohabitation with chromatindomain boundary elements at several places in the Drosophila genome, possibly defining a composite epigeneticmodule. We analysed 10 insect genomes in this context and find several conserved features in PREs across the insectspecies with some variations in their occurrence frequency. These analyses leading to the identification of PRE in insectgenomes contribute to our understanding of epigenetic mechanisms in these organisms.

Effect of vitexin on Nrf2/ARE pathway in alleviating oxidative stress in rats with acute cerebral ischemia-reperfusion / 中草药

Objective: To investigate the effect of vitexin on oxidative stress in rats with acute cerebral ischemia-reperfusion by regulating the pathway of nuclear factor E2-related factor 2 (Nrf2)/antioxidant response element (ARE). Methods: A total of 54 SD rats were randomly divided into Sham group, model group, positive control (edaravone 0.56 mg/kg) group and vitexin low, medium, and high dose (10, 20, 40 mg/kg) groups. The rat models with acute cerebral ischemia were established except the Sham group. After reperfusion, rats in Sham group and model group were received ip saline. The edaravone group and vitexin groups were administered according to the corresponding dose, once every 8 h for a total of three times. The neurobehavioral scores of rats before and after intervention were compared. HE staining was used to detect the pathological changes of cerebral cortex. The levels of MDA, NO, SOD, and GSH in cerebral cortex of rats were detected by the kit. The mRNA and protein expression levels of Nrf2/ARE pathway related gene in rat cerebral cortex were detected by real-time fluorescent quantitative PCR (qRT-PCR) and Western blotting. Results: Before and after intervention, there was no significant change in the neurobehavioral score of rats in the Sham group, the model group was higher than before intervention (P < 0.01), the edaravone group and the vitexin groups were lower than before intervention (P < 0.01), and there was a significant difference in the neurobehavioral score between the groups after intervention (P < 0.01). In the Sham group, the distribution of nerve cells was uniform and dense, and the morphology of cell body and nucleus was normal. In the model group, edaravone group and vitexin group, the arrangement of brain tissue was disordered and loose, in which liquefying necrosis and disappearance of cell structure were observed in the model group; in the low-dose group, the arrangement of cells was seriously disordered and loose. In the vitexin medium dose group and edaravone group, the area of liquefying necrosis was small, and most of the cells were normal; In the vitexin high dose group, only a few liquefying necrosis were found, the cell structure was basically normal, and the cell arrangement was slightly disordered. Compared with the Sham group, the levels of MDA and NO in the cerebral cortex of the model group were significantly increased (P < 0.01), the levels of SOD and GSH were significantly reduced (P < 0.01), and the expression levels of Nrf2 and γ-GCS mRNA were significantly increased (P < 0.01), the expression of cytoplasmic Nrf2 and γ-GCS proteins were significantly increased (P < 0.01), and the expression levels of nuclear Nrf2 and HO-1 proteins were significantly decreased (P < 0.01). Compared with the model group, the levels of MDA and NO in the cerebral cortex of rats in the edaravone group and low, medium and high dose groups of vitexin were significantly reduced (P < 0.01), and the levels of SOD and GSH were significantly increased (P < 0.01), Nrf2 and γ-GCS mRNA expression levels were significantly reduced (P < 0.01), cytoplasmic Nrf2, γ-GCS protein expressions were significantly reduced (P < 0.01), and nuclear Nrf2 and HO-1 protein expression levels were significantly increased (P < 0.01). And the levels of MDA, NO, SOD, GSH and Nrf2, γ-GCS, HO-1 mRNA and protein expression in rat cerebral cortex in each dose group were dose-dependent, with significant differences between groups (P < 0.01). Conclusion: Vitexin can alleviate oxidative stress in rats with acute cerebral ischemia-reperfusion. It is speculated that it is related to the regulation of Nrf2/ARE signaling pathway, the up-regulation of Nrf2 gene and protein expression, the promotion of its movement from cytoplasm to nucleus, the up-regulation of HO-1 expression, the inhibition of γ-GCS expression, and the enhancement of the body’s ability to response to oxidative stress.

Efectividad de los suplementos antioxidantes en la mejoría del desempeño físico atlético. Artículo de revisión / Effectiveness of antioxidant supplements in the improvement of athletic physical performance: Review article

Introducción: En la actualidad se ha incrementado el uso de antioxidantes en el ámbito deportivo, sin embargo, no existe evidencia concluyente del efecto de estas sustancias en la mejora del desempeño físico de los atletas. Objetivo: Determinar la efectividad del uso de suplementos antioxidantes en la mejoría del desempeño físico atlético. Material y Métodos: Se realizó una revisión bibliográfica en bases de datos en línea como Pubmed, Scopus, la Web of Knowledge y el buscador google academic. Se incluyeron solo trabajos originales de estudios doble ciego relacionados con la intervención de un suplemento antioxidante. El periodo de revisión fue del 2009 a diciembre del 2017. Desarrollo: Se identificaron un total de 1053 artículos de los cuales 33 cumplieron con los criterios de inclusión de la revisión. De acuerdo con el tipo de suplemento, 2 correspondieron a vitaminas, 9 a polifenoles, 11 comerciales y los 9 restantes diversos. La antigüedad de los artículos analizados fue de 4,8 ± 2,4 años, en cuanto a la obsolescencia, determinado por el semiperiodo de Burton y Kleber y el índice de Price, fue 5,5 y 61,0 por ciento respectivamente. Conclusiones: Hasta el momento no existe evidencia sólida de que la ingesta de suplementos antioxidantes mejore el desempeño físico atlético. Son pocos los resultados positivos en alguna de las variables evaluadas, por tal motivo se requiere de mayor evidencia para poder dilucidar el efecto de los suplementos antioxidantes(AU)

Introduction: At present, the use of antioxidants in the sports field has increased. However, there is no conclusive evidence of the effect of these substances in improving the physical performance of athletes. Objective: To determine the effectiveness of antioxidant supplements in the improvement of athletic physical performance. Material and Methods: A bibliographic review was carried out through the search on online databases such as Pubmed, Scopus, the Web of Knowledge and Google Scholar search engine. Only original double-blind studies related to the intervention of an antioxidant supplement were included. The review period was from 2009 to December 2017. Development: A total of 1053 articles were identified, of which 33 met the inclusion criteria for the review. Regarding the type of supplement, 2 of them corresponded to vitamins, 9 to polyphenols, 11 to commercials, and the remaining 9 ones to several types. The historic period of the articles analyzed was 4.8 ± 2.4 years in terms of obsolescence, which was determined by the Burton and Kleber half-period and the Price index (5.5 and 61.0 percent respectively). Conclusions: To date, there is no solid evidence that the intake of antioxidant supplements improves physical athletic performance. There are few positive results in some of the evaluated variables; for this reason, more evidence is required to elucidate the effect of antioxidant supplements(AU)

The effects of astragalus polysaccharides on insulin resistance and Nrf2-ARE pathway in gestational diabetic rats / 中国医师杂志

Objective@#To investigate the effects of astragalus polysaccharides (APS) on insulin resistance and nuclear factor-related factor 2 (Nrf2) -antioxidant response element (ARE) pathway in gestational diabetic rats.@*Methods@#Pregnant Sprague Dawley (SD) rats were divided into normal pregnancy group (control group), model group [gestational diabetes mellitus (GDM) group], low-dose astragalus polysaccharide group (APS-L group), middle-dose astragalus polysaccharide group (APS-M group), high-dose astragalus polysaccharide group (APS-H group), pioglitazone group (Pio group). GDM rat model was established by intraperitoneal injection of streptozotocin (STZ). The levels of fasting blood glucose (FBG), fasting insulin (FINS), adiponectin (APN), tumor necrosis factor-α (TNF-α), Leptin, malondialdehyde (MDA), and superoxde dismutase (SOD) were measured before delivery and 20 days after pregnancy, then the insulin resistance index was calculated; histopathological changes of pancreas were observed by hematoxylin-eosin(HE) staining; the expressions of Nrf2, heme oxygenase-1 (HO-1), and γ-glutamyl cysteine synthase (γ-GCS)mRNAs were detected by real-time fluorescence quantitative polymerase chain reaction (qRT-PCR); Western blot was used to detect the expressions of Nrf2, HO-1, and γ-GCS proteins in pancreatic tissues.@*Results@#Compared with the control group, the levels of APN and SOD in GDM group were significantly lower (P<0.05); the levels of APN and SOD increased significantly after APS treatment, but there was no significant difference between APS-H group and Pio group; compared with the control group, the levels of TNF-α, Leptin, and MDA in the GDM group increased significantly (P<0.05); after APS treatment, the levels of TNF-α, Leptin, and MDA were significantly decreased (P<0.05), and with the increase of APS concentration, the effect of reduction was obvious, but there was no significant difference between APS-H group and Pio group; compared with the control group, the levels of FBG, FINS, insulin secretion index (IS), and insulin resistance index (IRI) in GDM group were significantly higher (P<0.05); compared with the GDM group, the levels of FBG, FINS, IS, and IRI in APS group were significantly lower, and with the increase of APS concentration, the effect of reduction was obvious, but there was no significant difference between APS-H group and Pio group; compared with the control group, the insulin sensitivity index (ISI) level in GDM group was significantly lower (P<0.05), while the level of ISI in APS group was significantly higher when treated with APS (P<0.05); the results of HE staining showed that the islet cells in the control group were regular round or oval with clear boundary; in the GDM group, the number of islets decreased significantly, while the islets atrophied without obvious boundary; after APS treatment, the number of islets increased, and the pathological damage was significantly reduced, the islet cells in Pio group showed a clear boundary after treatment; qRT-PCR showed that the expressions of Nrf2, HO-1, and γ-GCS in GDM group were significantly higher than those in control group (P<0.05), after APS treatment, the expression levels of Nrf2, HO-1, and γ-GCS decreased significantly (P<0.05), but there was no significant difference between APS-H group with Pio group; Western Blot results showed that the expressions of Nrf2, HO-1, and γ-GCS in GDM group were significantly higher than those in control group (P<0.05), after APS treatment, the levels of Nrf2, HO-1, and γ-GCS in APS group and Pio group were significantly lower than those in GDM group, but there was no significant difference between APS-H group with Pio group.@*Conclusions@#Astragalus polysaccharide can reduce insulin resistance in diabetic rats, which may play the role through Nrf2-ARE pathway.

Progress in Nrf2/ARE signaling pathway and drug-resistance of tumor / 肿瘤

Nuclear factor E2-related factor 2 (Nrf2), an important transcription factor, is able to regulate Nrf2/antioxidant response element (ARE) signaling pathway, including the expressions of a series of cytoprotective proteins such as heme oxygenase-1 (HO-1), glutathione-S -transferase (GST) and quinine oxidoreductase 1 (NQO1), so as to maintain redox homeostasis and play a significant role in the prevention of cancer. However, the recent studies show that Nrf2 has another side. Nrf2 may promote the occurrence and development of tumors, and lead to drug resistance of tumor to chemotherapy, resulting in tremendous difficulties to the clinical treatment of tumors. Therefore, Nrf2/ARE signaling pathway is regarded as a breakthrough in overcoming drug resistance. This review summarizes the basic features and functions of Nrf2/ ARE signaling pathway, the dual functions of Nrf2, and the relationship between Nrf2 and multidrug resistance of tumors, all of which should facilitate the development of new strategies to improve chemotherapeutic efficacy.

The effects of astragalus polysaccharides on insulin resistance and Nrf2-ARE pathway in gestational diabetic rats / 中国医师杂志

Objective To investigate the effects of astragalus polysaccharides (APS) on insulin resistance and nuclear factor-related factor 2 (Nrf2)-antioxidant response element (ARE) pathway in gestational diabetic rats.Methods Pregnant Sprague Dawley (SD) rats were divided into normal pregnancy group (control group),model group [gestational diabetes mellitus (GDM) group],low-dose astragalus polysaccharide group (APS-L group),middle-dose astragalus polysaccharide group (APS-M group),high-dose astragalus polysaccharide group (APS-H group),pioglitazone group (Pio group).GDM rat model was established by intraperitoneal injection of streptozotocin (STZ).The levels of fasting blood glucose (FBG),fasting insulin (FINS),adiponectin (APN),tumor necrosis factor-α (TNF-α),Leptin,malondialdehyde (MDA),and superoxde dismutase (SOD) were measured before delivery and 20 days after pregnancy,then the insulin resistance index was calculated;histopathological changes of pancreas were observed by hematoxylin-eosin(HE) staining;the expressions of Nrf2,heme oxygenase-1 (HO-1),and γ-glutamyl cysteine synthase (γ-GCS)mRNAs were detected by real-time fluorescence quantitative polymerase chain reaction (qRT-PCR);Western blot was used to detect the expressions of Nrf2,HO-1,and γ-GCS proteins in pancreatic tissues.Results Compared with the control group,the levels of APN and SOD in GDM group were significantly lower (P ＜ 0.05);the levels of APN and SOD increased significantly after APS treatment,but there was no significant difference between APS-H group and Pio group;compared with the control group,the levels of TNF-α,Leptin,and MDA in the GDM group increased significantly (P ＜ 0.05);after APS treatment,the levels of TNF-α,Leptin,and MDA were significantly decreased (P ＜ 0.05),and with the increase of APS concentration,the effect of reduction was obvious,but there was no significant difference between APS-H group and Pio group;compared with the control group,the levels of FBG,FINS,insulin secretion index (IS),and insulin resistance index (IRI) in GDM group were significantly higher (P ＜ 0.05);compared with the GDM group,the levels of FBG,FINS,IS,and IRI in APS group were significantly lower,and with the increase of APS concentration,the effect of reduction was obvious,but there was no significant difference between APS-H group and Pio group;compared with the control group,the insulin sensitivity index (ISI) level in GDM group was significantly lower (P ＜0.05),while the level of ISI in APS group was significantly higher when treated with APS (P ＜ 0.05);the results of HE staining showed that the islet cells in the control group were regular round or oval with clear boundary;in the GDM group,the number of islets decreased significantly,while the islets atrophied without obvious boundary;after APS treatment,the number of islets increased,and the pathological damage was significantly reduced,the islet cells in Pio group showed a clear boundary after treatment;qRT-PCR showed that the expressions of Nrf2,HO-1,and γ-GCS in GDM group were significantly higher than those in control group (P ＜ 0.05),after APS treatment,the expression levels of Nrf2,HO-1,and γ-GCS decreased significantly (P ＜ 0.05),but there was no significant difference between APS-H group with Pio group;Western Blot results showed that the expressions of Nrf2,HO-1,and γ-GCS in GDM group were significantly higher than those in control group (P ＜ 0.05),after APS treatment,the levels of Nrf2,HO-1,and γ-GCS in APS group and Pio group were significantly lower than those in GDM group,but there was no significant difference between APS-H group with Pio group.Conclusions Astragalus polysaccharide can reduce insulin resistance in diabetic rats,which may play the role through Nrf2-ARE pathway.

LBP reduces theinflammatory injuryof kidney in septic rat and regulates the Keap1-Nrf2∕ARE signaling pathway

Abstract Purpose: To investigate the influence of lycium barbarum polysaccharides (LBP), a functional derivative from lycium barbarum, on septic kidney injury. Methods: The SD male rats were randomly divided into 8 groups. The concentration of IL-1β, IL-6, IL-8, TNF-α, NF-κB and ROS, in kidney cortex homogenates after 12 h treatments were determined by enzyme-linked immunosorbent assay and ROS test kit, respectively. Morphology observation of kidney tissue was conducted with HE staining. The mRNA and protein expression levels of Nrf2, HO-1, NQO1, NF-κB, and Keap1 in kidney tissues were determined by qRT-PCR and Western blot, respectively. Results: LPS treatment significantly increased the oxidative stress. After LBP treatment, the ROS content reduced significantly in a dose-depend manner. However, the levels of HO-1, NQO1 and Nrf2 as molecular elements that respond to oxidative stress were further increased. Also, administration of LBP increased the levels of NF-κB and Keap1, and decreased the levels of Nrf2 in the Keap 1-Nrf2∕ARE signaling pathway. By administrating the brusatol, the inhibition of Nrf2 enhanced the expression of NF-κB, inhibits the antioxidant responses, and further reverse the protective effect of LBP on the LPS induced septic kidney injury. Conclusion: Lycium barbarum polysaccharides can reduce inflammation and activate the antioxidant responses via regulating the level of pro-inflammatory cytokines and the Keap1-Nrf2/ARE signaling pathway.

Effect of penehychdine hydrochloride pretreatment on Nrf2/ARE signaling pathway during myocardial ischemia-reperfusion in rats / 中华麻醉学杂志

Objective To evaluate the effect of penehychdine hydrochloride pretreatment on nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling pathway during myocardial ischemia-reperfusion (Ⅰ/R) in rats.Methods Thirty-six clean-grade healthy male Sprague-Dawley rats,aged 2-3 months,weighing 220-240 g,were divided into 3 groups (n=12 each) using a random number table method:sham operation group (group S),myocardial Ⅰ/R group and penehyelidine hydrochloride pretreatment group (group PHC).Myocardial Ⅰ/R was induced by occlusion of the anterior descending branch of left coronary artery for 30 min followed by 120 min reperfusion.At 30 min before ischemia,penehyelidine hydrochloride 2 mg/kg was injected intraperitoneally in group PHC,and the anterior descending branch of left coronary artery was only exposed but not ligated in group S.Rats were sacrificed at the end of reperfusion,and hearts were removed for measurement of the myocardial infarct size (by 2,3,5-triphenyltetrazolium chloride staining),cell apoptosis (by TUNEL) and expression of Nrf2,heme oxygenase-1 (HO-1),NQO1 and γ-glutamylcysteine synthetase (γ-GCS) protein and mRNA (by using Western blot or real-time fluorescence quantitative polymerase chain reaction).The percentage of myocardial infarct size and apoptosis index were calculated.Results Compared with group S,the percentage of myocardial infarct size and apoptosis index were significantly increased,and the expression of Nrf2,HO-1,NQO1 and γ-GCS protein and mRNA was down-regulated in Ⅰ/R and PHC groups (P＜0.05).Compared with group l/R,the percentage of myocardial infarct size and apoptosis index were significantly decreased,and the expression of Nrf2,HO-1,NQO1 and γ-GCS protein and mRNA was up-regulated in group PHC (P＜0.05).Conclusion Penehyclidine hydrochloride pretreatment attenuates myocardial Ⅰ/R injury through activating Nrf2-ARE signaling pathway in rats.

Role of Nrf2/ARE signaling pathway in propofol-induced reduction of lung ischemia-reperfusion injury in aged rats / 中华麻醉学杂志

Objective To evaluate the role of nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling pathway in propofol-induced reduction of lung ischemia-reperfusion (I/R) injury in aged rats.Methods Thirty-two clean healthy male Sprague-Dawley rats,aged 18-22 months,weighing 450-600,were divided into 4 groups (n =8 each) using a random number table:sham operation group (group S),I/R group (group I/R),I/R plus propofol group (group I/R+P) and all-trans retinoic acid (ARTA) plus I/R plus propofol group (group ARTA+I/R+P).Lung I/R was induced by occlusion of the right hilum of lung for 60 min followed by 120 min of reperfusion in anesthetized rats.In group ATRA+I/R+P,Nrf2/ARE signaling pathway blocker ARTA 6 mg/kg was intraperitoneally injected once a day for 3 consecutive days,and the model of lung I/R injury was established at 2 h after the last administration.In group I/R+P and group ARTA+I/R+P,while the model of lung I/R injury was established,propofol 30 mg · kg-1 · h-1 was infused via the caudal vein until 120 min of reperfusion.The rats were sacrificed at 120 min of reperfusion and then the lungs were removed for examination of the pathological changes which were scored and for measurement of wet/dry weight ratio (W/D ratio),superoxide dismutase (SOD) activity (by xanthine oxidase method),malondialdehyde (MDA) content (using thiobarbituric acid method) and expression of Nrf2 and heme oxygenase-1 (HO-1) protein (by Western blot).Results Compared with group S,the pathological scores,W/D ratio and MDA content were significantly increased,and the activity of SOD was decreased in I/R and ATRA+I/R+P groups,and the expression of Nrf-2 and HO-1 was significantly up-regulated in I/R,I/R+P and ATRA+I/R+P groups (P＜0.05).Compared with group I/R,the pathological scores,W/D ratio and MDA content were significantly decreased,the activity of SOD was increased,and the expression of Nrf-2 and HO-1 was up-regulated in group I/R+P (P＜0.05),and no significant change was found in the indexes mentioned above in group ARTA+I/R+P (P＞0.05).Compared with group I/R+P,the pathological scores,W/D ratio and MDA content were significantly increased,the activity of SOD was decreased,and the expression of Nrf-2 and HO-1 was down-regulated in group ARTA+ I/R+P (P＜0.05).Conclusion Nrf2/ARE signaling pathway activation is involved in propofol-induced reduction of lung I/R injury in aged rats.

Role of Nrf2/ARE signaling pathway in reduction of myocardial ischemia-reperfusion injury by ischemic preconditioning in rats / 中华麻醉学杂志

Objective To evaluate the role of nuclear factor erythroid 2-related factor 2 (Nrf2)/ antioxidant response element (ARE) signaling pathway in reduction of myocardial ischemia-reperfusion (I/R) injury by ischemic preconditioning in the rats.Methods Healthy male Sprague-Dawley rats,weighing 250-300 g,aged 4-6 months,were used in the study.Their hearts were excised,and retrogradely perfused with K-H solution at 37 ℃ in a Langendorff apparatus.Forty isolated hearts were randomly divided into 4 groups (n=10 each) using a random number table:control group (group C),I/R group,ischemic preconditioning group (group IPC),and ischemic preconditioning +Nrf2/ARE signaling pathway blocker luteolin group (group IPC+L).After 20 min of equilibration,the hearts were continuously perfused for 100 min in group C.After 20 min of equilibration,the hearts were subjected to 40 min ischemia at 32 ℃ followed by 60 min of reperfusion in group I/R.In group IPC,ischemic preconditioning was induced by 6 cycles of 10 s ischemia followed by 10 s reperfusion starting from the time point immediately after 20 min of equilibration,and then the hearts were subjected to 40 min ischemia at 32 ℃ followed by 58 min of reperfusion.In group IPC+L,after 20 min of equilibration,the hearts were perfused with K-H solution containing lueolin 50 μmol/L for 3 min before ischemia,and the other treatments were similar to those previously described in group IPC.Left ventricular developed pressure (LVDP),left ventricular end-diastolic pressure (LVDEP),heart rate (HR),and the maximum rate of increase of left ventricular pressure (+dp/dtmax) were recorded at the end of equilibration and reperfusion.At the end of reperfusion,left ventricular myocardial tissues were obtained for examination of the ultrastructure of myocardial cells and for determination of the expression of Nrf2,heme oxygenase-1 (HO-1),quinone oxidoreductase 1 (NQO1),and superoxide dismutase 1 (SOD1) mRNA and protein (by real-time polymerase chain reaction and Western blot,respectively).Results Compared with group C,the HR,+ dp/dtmax and LVDP were significantly decreased,and LVEDP was significantly increased at the end of reperfusion in I/R and IPC+L groups,and the expression of Nrf2,HO-1,NQO1 and SOD1 mRNA and protein was significantly up-regulated in I/R,IPC and IPC+L groups (P＜0.05).Compared with group I/R,the HR,+dp/dtmax and LVDP were significantly increased,and LVEDP was significantly decreased at the end of reperfusion,the expression of Nrf2,HO-1,NQO1 and SOD1 mRNA and protein was significantly up-regulated (P＜0.05),and the pathological changes were significantly attenuated in group IPC,and no significant change was found in the parameters mentioned above in group IPC+L (P＞0.05).Compared with group IPC,the HR,+dp/dt and LVDP were significantly decreased,and LVEDP was significantly increased at the end of reperfusion,and the expression of HO-1,NQO1,SOD1 mRNA and protein was significantly down-regulated (P＜ 0.05),no significant change was found in Nrf2 mRNA and protein expression (P＞0.05),and the pathological changes were significantly aggravated in group IPC + L.Conclusion Ischemic preconditioning reduces myocardial I/R injury through activating Nrf2/ARE signaling pathway in the rats.

Ethanol Extract of Cirsium japonicum var. ussuriense Kitamura Exhibits the Activation of Nuclear Factor Erythroid 2-Related Factor 2-dependent Antioxidant Response Element and Protects Human Keratinocyte HaCaT Cells Against Oxidative DNA Damage

Keratinocytes are constantly exposed to extracellular insults, such as ultraviolet B, toxic chemicals and mechanical stress, all of which can facilitate the aging of keratinocytes via the generation of intracellular reactive oxygen species (ROS). Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that plays a critical role in protecting keratinocytes against oxidants and xenobiotics by binding to the antioxidant response element (ARE), a cis-acting element existing in the promoter of most phase II cytoprotective genes. In the present study, we have attempted to find novel ethanol extract(s) of indigenous plants of Jeju island, Korea that can activate the Nrf2/ARE-dependent gene expression in human keratinocyte HaCaT cells. As a result, we identified that ethanol extract of Cirsium japonicum var. ussuriense Kitamura (ECJUK) elicited strong stimulatory effect on the ARE-dependent gene expression. Supporting this observation, we found that ECJUK induced the expression of Nrf2, hemoxygenase-1, and NAD(P)H:quinone oxidoreductase-1 and this event was correlated with Akt1 phosphorylation. We also found that ECJUK increased the intracellular reduced glutathione level and suppressed 12-O-tetradecanoylphorbol acetate-induced 8-hydroxyguanosine formation without affecting the overall viability. Collectively, our results provide evidence that ECJUK can protect against oxidative stress-mediated damages through the activation of Nrf2/ARE-dependent phase II cytoprotective gene expression.

The research progress of lncRNA as CeRNA in gastric cancer / 中国药理学通报

Recent studies have showed that RNAs regulate each other with microRNA ( miRNA ) response elements ( MREs ) , and this mechanism is known as “competing endogenous RNA (ceRNA)” hypothesis. Long noncoding RNAs(lncRNAs) are non-protein coding transcripts longer than 200 nucleotides. Ab-errant expression of lncRNAs has been found associated with gastric cancer, one of the most malignant tumors. Compelling evidence suggests that lncRNAs can interact with miRNAs and regulate the expression of miRNAs as ceRNAs. Several lncRNAs such as GAPLINC, BC032469, H19, HOTAIR, FER1L4 and MEG3 have been found to be associated with miRNAs in gastric cancer( GC) . It is tempting to speculate that a multitude of ln-cRNAs may interrupt definitive steps in GC suppressive and on-cogenic pathways. The uncovering of the underlying mechanisms of lncRNAs may benefit our understanding of gastric cancer′s pathogenesis.

Role of Nrf2∕ARE signaling pathway in inhibition of LPS-induced inflammatory factor release from macrophages by hydrogen / 中华麻醉学杂志

Objective To evaluate the role of nuclear factor erythroid 2?related factor 2 ( Nrf2)∕antioxidant response element( ARE) signaling pathway in inhibition of lipopolysaccharide ( LPS)?induced inflammatory factor release from macrophages by hydrogen. Methods RAW264. 7 macrophages of mice were cultured in 6?well plates (2×106 cells∕well) and were divided into 4 groups (n=24 each) using a random number table: control group ( group C); LPS group; hydrogen?rich saline+LPS group ( group LPS+H2); Nrf2 small interference RNA (siRNA)+LPS+hydrogen?rich saline group (siRNA+LPS+H2 group) . LPS 1 μg∕ml was added in group LPS. In group LPS+H2 , LPS 1μg∕ml was added, and the cul?ture medium was then replaced with the culture medium containing 0. 6 mmol∕L hydrogen?rich saline. In group siRNA+LPS+H2 , after Nrf2?siRN was successfully transfected into the cells, the cells were continu?ously incubated for 24 h, and the culture medium was then replaced with the culture medium containing 0.6 mmol∕L hydrogen?rich saline after LPS 1 μg∕ml was added. At 24 h of incubation, the supernatant was sep?arated for determination of the lactic dehydrogenase (LDH) activity (using colorimetric method) and for detection of the concentrations of tumor necrosis factor?alpha ( TNF?α) , interleukin?1 beta ( IL?1β) , high mobility group box?1 (HMGB1) and IL?6 (by ELISA). The cells were collected for measurement of the proliferation of cells ( by methyl thiazolyl tetrazolium assay) and for determination of the expression of Nrf2 and heme oxygenase?1 ( HO?1) in cells ( by Western blot) . Results Compared with group C, the LDH activity and concentrations of TNF?α, IL?1β, IL?6 and HMGB1 in the supernatant were significantly in?creased, the proliferation of cells was significantly decreased, and the expression of HO?1 in cells was sig?nificantly up?regulated in LPS and siRNA+LPS+H2 groups, and the expression of Nrf2 in cells was signifi?cantly up?regulated in LPS and LPS+H2 groups (P<0.05). Compared with group LPS, the LDH activity and concentrations of TNF?α, IL?1β, IL?6 and HMGB1 in the supernatant were significantly decreased, the proliferation of cells was significantly increased, and the expression of Nrf2 and HO?1 in cells was sig?nificantly up?regulated in group LPS+H2 , and the expression of Nrf2 and HO?1 in cells was significantly down?regulated in group siRNA+LPS+H2 ( P<0.05) . Compared with group LPS+H2 , the LDH activity and concentrations of TNF?α, IL?1β, IL?6 and HMGB1 in the supernatant were significantly increased, the proliferation of cells was significantly decreased, and the expression of Nrf2 and HO?1 in cells was signifi?cantly down?regulated in group LPS+H2+siRNA ( P<0.05) . Conclusion The mechanism by which hydro?gen inhibits LPS?induced inflammatory factor release from macrophages is related to the activation of Nrf2∕ARE signaling pathway in mice.

Effect of emulsified isoflurane postconditioning on Nrf2-ARE signaling pathway during myocardial ischemia-reperfusion in rats in vitro / 中华麻醉学杂志

Objective To evaluate the effect of emulsified isoflurane postconditioning on nuclear factor?E2 related factor 2 ( Nrf2 )?antioxidant response element ( ARE ) signaling pathway during myocardial ischemia?reperfusion ( I∕R ) in rats in vitro. Methods Healthy male Sprague?Dawley rats, aged 4-5 months, weighing 250-300 g, were heparinized and anesthetized with intraperitoneal 1% amobarbital sodium 40 mg∕kg. Their hearts were excised and perfused in a Langendorff apparatus with K?H solution. Thirty?two isolated rat hearts were randomly divided into 4 groups ( n=8 each ) using a random number table: control group (group C), group I∕R, emulsified isoflurane postconditioning group (EIP group) and fat emulsion group ( group F) . After 20 min of equilibration, group C was continuously perfused with K?H solusion for 100 min. Group I∕R underwent 40 min of ischemia at 32 ℃, followed by reperfusion for 60 min. In EIP and F groups, after undergoing 40 min of global ischemia, the isolated hearts were perfused for 2 min with K?H solution containing 1.68 mmol∕L emulsified isoflurane and 712 mg∕L intralipid, respectively, starting from the onset of reperfusion, and then were continuously perfused with K?H solution containing oxygen at 37 ℃ for 58 min. Heart rate (HR), left ventricular developed pressure (LVDP), left ventricular end?diastolic pressure ( LVEDP ) , and positive maximal pressure of left ventricular increase (+dp∕dtmax ) were recorded at the end of equilibration and reperfusion. At the end of reperfusion, myocardial specimens were obtained from the left ventricle for examination of the ultrastructure of myocardial cells and for determination of Nrf2, heme oxygenase?1 ( HO?1) , quinone oxidoreductase 1 ( NQO1) , and superoxide dismutase 1 ( SOD1) and mRNA expression using Western blot and real?time PCR. Results Compared with group C, HR, +dp∕dtmax and LVDP were significantly decreased, and LVEDP was increased at the end of reperfusion in I∕R and F groups, LVDP was significantly decreased, LVEDP was increased, and no significant changes were found in HR and +dp∕dtmax at the end of reperfusion in EIP group, and Nrf2, HO?1, NQO1 and SOD1 and mRNA expression was down?regulated at the end of reperfusion in I∕R, EIP and F groups. Compared with group I∕R, HR, +dp∕dtmax and LVDP were significantly increased, and LVEDP was decreased at the end of reperfusion in EIP and F groups, Nrf2, HO?1, NQO1 and SOD1 and mRNA expression was significantly up?regulated at the end of reperfusion in EIP group, and Nrf2, HO?1, NQO1 and SOD1 mRNA expression was significantly up?regulated, Nrf2 and HO?1 expression was up?regulated, and no significant changes were found in NQO1 and SOD1 expression at the end of reperfusion in group F. Compared with group EIP, HR, +dp∕dtmax and LVDP were significantly decreased, LVEDP was increased, and Nrf2, HO?1, NQO1 and SOD1 and mRNA expression was down?regulated in group F. Conclusion Emulsified isoflurane postconditioning attenuates myocardial I∕R injury probably by activating Nrf2?ARE signaling pathway in isolated rat hearts.

Effect of hydrogen-rich saline on Nrf2∕ARE pathway in peripheral nerve in a rat model of diabetic neuropathic pain / 中华麻醉学杂志

Objective To evaluate the effect of hydrogen?rich saline on nuclear factor erythroid 2?related factor 2 ( Nrf2)∕antioxidant response element ( ARE) pathway in the peripheral nerve in a rat model of diabetic neuropathic pain ( DNP ) . Methods Thirty?six healthy male Sprague?Dawley rats, aged 8 weeks, weighing 180-200 g, were randomly divided into 3 groups ( n=12 each) using a random number table: control group ( C group) , DNP group and hydrogen?rich saline group ( HRS group) . Diabetes melli?tus was produced by intraperitoneal 1% streptozocin ( STZ) 65 mg∕kg and confirmed by fasting blood glucose concentration>16?67 mmol∕L. Hydrogen?rich saline 5 ml∕kg was injected intraperitoneally once a day for 14 consecutive days starting from 14 days after STZ injection in group HRS, and the equal volume of normal saline was given in C and DNP groups. The mechanical paw withdrawal threshold ( MWT) and thermal paw withdrawal latency ( TWL) were measured at 2 days before STZ injection ( T0 ) , and 7, 14, 21 and 28 days after STZ injection ( T1?4 ) . After measurement of the pain threshold at T4 , the motor nerve conduction velocity ( MNCV) of the right hindlimb and distal motor latency were measured. The expression of Nrf2 in nucleoprotein and HO?1 and NQO1 in total protein was detected in the sciatic nerve by Western blot. Re?sults Compared with group C, the MWT was significantly decreased, and the TWL was shortened at T1?4 , and the expression of Nrf2 in nucleoprotein and HO?1 and NQO1 in total protein was up?regulated in DNP and HRS groups (P<0?05). Compared with group DNP, the MWT was significantly increased, and the TWL was prolonged at T3 and T4 , and the expression of Nrf2 in nucleoprotein and HO?1 and NQO1 in total protein was up?regulated in group HRS ( P<0?05) . Conclusion The mechanism by which hydrogen?rich saline mitigates DNP is related to activated Nrf2∕ARE pathway in the peripheral nerve of rats.

Mechanism of ischemic postconditioning-induced activation of Nrf2-ARE signaling pathway during myocardial ischemia-reperfusion: the relationship with ROS / 中华麻醉学杂志

Objective To investigate the relationship between the mechanism of ischemic postconditioning-induced activation of nuclear factor-E2 related factor 2 (Nrf2)-antioxidant response element (ARE) signaling pathway during myocardial ischemia-reperfusion (I/R) and reactive oxygen species (ROS).Methods Healthy male Sprague-Dawley rats, aged 16-20 weeks, weighing 250-300 g, were heparinized and anesthetized with intraperitoneal 1％ pentobarbital sodium 40 mg/kg.Their hearts were excised and perfused in a Langendorff apparatus with K-H solution.Thirty-two isolated rat hearts were randomly divided into 4 groups (n=8 each) using a random number table: control group (group C) , group I/R,ischemic postconditioning group (group IPO) , and N-(2-mercaptopropionyl)-glycine (a ROS scavenger) + IPO group (group M + IPO).After 20 min of equilibration, group C was continuously perfused with K-H solution for 100 min, and the isolated hearts received the drugs via the perfusion system in the other groups.Group I/R was perfused with cardioplegic solution 4 ℃ St.Thomas, and then was subjected to 40 min of ischemia at 32 ℃ followed by 60 min of reperfusion.In group IPO, ischemic postconditioning was induced by 6 cycles of 10 s reperfusion followed by 10 s limb ischemia starting from the onset of reperfusion, and the hearts were then perfused for 58 min.In group M + IPO, the hearts were perfused with K-H solution containing N-(2-mercaptopropionyl)-glycine 2 m mol/L for 3 min starting from the onset of reperfusion,underwent 2 min of ischemic postconditioning, and then was perfused for 55 min.Heart rate (HR), left ventricular developed pressure (LVDP), left ventricular end-diastolic pressure (LVEDP),and positive maximal pressure of left ventricular increase (+dp/dtmax) were recorded at the end of equilibration and of reperfusion.At 5 min of reperfusion and the end of reperfusion, myocardial specimens were obtained from the left ventricle for determination of ROS content by enzyme-linked immunosorbent assay.At the end of reperfusion, myocardial specimens were obtained from the left ventricle for examination of the ultrastructure of myocardial cells and for determination of Nrf2, heme oxygenase-1 (HO-1) , quinone oxidoreductase 1 (NQO1), and superoxide dismutase 1 (SOD1) mRNA and protein expression (by using Western blot and real-time polymerase chain reaction).The damage to myocardial mitochondria was assessed using Flameng scoring.Results Compared with group C, HR, +dp/dtmax and LVDP were significantly decreased, and LVEDP was increased at the end of reperfusion in I/R and M+IPO groups, HR and LVDP were decreased, LVEDP was increased, and no significant changes were found in +dp/dtmax at the end of reperfusion in IPO group, Flameng score was increased in I/R, IPO and M+IPO groups , the ROS content was increased at the end of reperfusion in I/R, IPO and M+IPO groups, and Nrf2, HO-1,NQO1 and SOD1 mRNA and protein expression was down-regulated at the end of reperfusion in I/R, IPO and M+IPO groups.Compared with group I/R, HR, +dp/dtmax and LVDP were significantly increased, and LVEDP and ROS content were decreased at the end of reperfusion, Nrf2, HO-1, NQO1 and SOD1 mRNA and protein expression was up-regulated at the end of reperfusion in IPO and M+IPO groups, Flameng score was decreased in IPO group, there was no significant change in Flameng score in M+IPO group.Compared with group IPO, HR, +dp/dtmax and LVDP were significantly decreased, LVEDP and ROS content were increased at the end of reperfusion, Flameng score was increased, and Nrf2, HO-1, NQO1 and SOD1 mRNA and protein expression was down-regulated in M+IPO group.Conclusion Ischemic postconditioning can regulate ROS level and activate Nrf2-ARE signaling pathway, thus attenuating myocardial I/R injury in rats.

Effects of acute and chronic administration of methylprednisolone on oxidative stress in rat lungs / Efeitos da administração aguda e crônica de metilprednisolona no estresse oxidativo em pulmões de ratos

Objective: To determine the effects of acute and chronic administration of methylprednisolone on oxidative stress, as quantified by measuring lipid peroxidation (LPO) and total reactive antioxidant potential (TRAP), in rat lungs. Methods: Forty Wistar rats were divided into four groups: acute treatment, comprising rats receiving a single injection of methylprednisolone (50 mg/kg i.p.); acute control, comprising rats i.p. injected with saline; chronic treatment, comprising rats receiving methylprednisolone in drinking water (6 mg/kg per day for 30 days); and chronic control, comprising rats receiving normal drinking water. Results: The levels of TRAP were significantly higher in the acute treatment group rats than in the acute control rats, suggesting an improvement in the pulmonary defenses of the former. The levels of lung LPO were significantly higher in the chronic treatment group rats than in the chronic control rats, indicating oxidative damage in the lung tissue of the former. Conclusions: Our results suggest that the acute use of corticosteroids is beneficial to lung tissue, whereas their chronic use is not. The chronic use of methylprednisolone appears to increase lung LPO levels. .

Objetivo: Determinar os efeitos da administração aguda e crônica de metilprednisolona no estresse oxidativo, por meio da quantificação da peroxidação lipídica (POL) e do potencial antioxidante reativo total (PART), em pulmões de ratos. Métodos: Quarenta ratos Wistar foram divididos em quatro grupos: tratamento agudo, com ratos recebendo uma dose única de metilprednisolona (50 mg/kg i.p.); controle agudo, com ratos recebendo injeção unida de salina; tratamento crônico, com ratos recebendo metilprednisolona v.o. na água do bebedouro (6 mg/kg por dia durante 30 dias; e controle crônico, com ratos recebendo água de bebedouro normal). Resultados: Os níveis de PART foram significativamente maiores no grupo tratamento agudo que no grupo controle agudo, sugerindo uma melhora do sistema de defesa pulmonar. Os níveis de POL foram significativamente maiores no grupo tratamento crônico que no grupo controle crônico, indicando dano oxidativo no tecido pulmonar. Conclusões: Nossos resultados sugerem que o uso agudo de corticoides foi benéfico aos tecidos pulmonares, enquanto seu uso crônico não o foi. O uso crônico de metilprednisolona parece aumentar os níveis pulmonares da POL. .

Relationship between Nrf2-ARE pathway and acute lung injury induced by endotoxic shock in rabbits / 中华麻醉学杂志

Objective To evaluate the relationship between erythroid 2-related factor (Nrf2 )-antioxidant response element (ARE) pathway and acute lung injury (ALI) induced by endotoxic shock in rabbits .Methods Thirty healthy male New Zealand white rabbits ,aged 2 months ,weighing 1.5-2.0 kg ,were randomly divided into 3 groups (n=10 each) using a random number table :control group (group C) ,group ALI and all-trans retinoic acid group (group ATRA ) .In group ATRA ,all-trans retinoic acid 6 mg/kg (in filter sterilized vegetable oil 1.2 ml) was injected intraperitoneally once a day for 2 days .ALI was induced by lipopolysaccharide 5 mg/kg (in normal saline 2 ml ) injected via the auricular vein at 10 h after the last injection of ATRA in ALI and ATRA groups .The equal volume of normal saline was injected instead in group C .The rabbits were sacrificed at 6 h after lipopolysaccharide or normal saline administration .The pulmonary specimens were removed for determination of wet/dry lung weight ratio (W/D ratio ) and expression of Nrf2 mRNA and nuclear protein ,and HO-1 mRNA and protein in lung tissues .The pathological changes of lungs were scored .Results Compared with group C ,the pathological score and W/D ratio were significantly increased , and the expression of Nrf2 mRNA and nuclear protein ,and HO-1 mRNA and protein was up-regulated in ALI and ATRA groups ( P 0.05 ) .Conclusion Activation of Nrf2-ARE pathway is the regulatory mechanism of the body adapting to the ALI induced by endotoxic shock in rabbits .

Effects of hydrogen on nuclear factorE2-related factor 2/antioxidant response element pathway in lung tissues in septic mice / 中华麻醉学杂志

Objective To evaluate the effects of hydrogen (H2) on nuclear factorE2-related factor 2 (Nrf2)/antioxidant response element (ARE) pathway in lung tissues in septic mice.Methods Seventy-two male ICR mice,weighing 20-25 g,aged 6 weeks,were randomly divided into 4 groups (n =18 each) using a random number table:sham operation group (group SH),group H2,sepsis group (group S),and sepsis + H2 group (group S + H2).Sepsis was produced by cecal ligation and puncture (CLP).H2 and S + H2 groups inhaled 2％ H2 for 1 h starting from 1 and 6 h after CLP.Six mice in each group were chosen and sacrificed at 7,12 and 24 h after CLP (T1-3).The pulmonary specimens were obtained to determine the expression of Nrf2 and HO-1 protein (by Western blot) and Nrf2 mRNA (by RT-PCR).At 24 h after CLP,the pathological changes of lungs were scored,wet/dry lung weight ratio (W/D ratio) was determined,and the expression of high mobility group box-1 (HMGB-1) in lung tissues was measured (by Western blot).Results Compared with group SH,the pathological scores and W/D ratio were significantly increased,and the expression of Nrf2 protein and mRNA,HO-1 and HMGB1 was up-regulated in S and S + H2 groups,while no significant change was found in the indexes mentioned above in group H2.Compared with group S,the pathological scores and W/D ratio were significantly decreased,the expression of Nrf2 protein and mRNA and HO-1 was up-regulated and HMGB1 expression was down-regulated in group S + H2.Conclusion The mechanism by which H2 reduces acute lung injury in septic mice is related to activation of Nrf2/ARE pathway.