Objective To explore the sequential effects of hypoxic exercising on miR-27/PPARγand lipid metabolism targetgene and protein expression levels in the obesity rats’liver.Methods 13-week-old male diet-induced obesity ...Objective To explore the sequential effects of hypoxic exercising on miR-27/PPARγand lipid metabolism targetgene and protein expression levels in the obesity rats’liver.Methods 13-week-old male diet-induced obesity rats were randomlydivided into three groups(n=10):normal oxygen concentration quiet group(N),hypoxia quiet group(H),hypoxic exercise group(HE).Exercise training on the horizontal animal treadmill for 1 h/d,5 d/week for a total of 4 week,and the intensity of horizontaltreadmill training was 20 m/min(hypoxic concentration was 13.6%).Comparison of the weights of perirenal fat and epididymal fat in rats across different groups and calculation of Lee’s index based on body weight and body length of rats in each group were done.And the serum concentrations of total cholesterol(TC),triglyceride(TG),low density lipoprotein cholesterol(LDL-C),high-densitylipoprotein cholesterol(HDL-C)levels were detected.RT-PCR and Western Blot were used to detect the levels of miR-27,PPARγ,CYP7A1 and CD36.Results Hypoxic exercise decreased the expression levels of miR-27 in the obese rats’liver,however,theexpression level of PPARγwas gradually increased.The expression levels of miR-27 in HE group were significantly lower than Ngroup(P<0.05).The expression levels of PPARγmRNA in N group were significantly lower than H group(P<0.05),especially lowerthan HE group(P<0.01).The protein expression of PPARγprotein in N group was significantly lower than that other groups(P<0.01).The expression of lipid metabolism-related genes and proteins increased in the obese rats’liver.The expression of CYP7A1mRNA in N group was significantly lower than H group(P<0.05),especially lower than HE group(P<0.01).The expression ofCYP7A1 protein in the obese rats’liver in N group was extremely lower than H group and HE group(P<0.01).The proteinexpression of CD36 in N group was significantly lower than that in HE group(P<0.05).Hypoxia exercise improved the relatedphysiological and biochemical indexes of lipid metabolism disorder.The perirenal fat weight of obese rats in HE group wasextremely lower than N group and H group(P<0.01),and the perirenal fat weight in N group was significantly higher than H group(P<0.05).The epididymal fat weight in N group was significantly higher than H group(P<0.05),and extremely higher than HEgroup(P<0.01).The Lee’s index in HE group was extremely lower than N group and H group(P<0.01).The serum concentration ofTC in obese rats in HE group was extremely lower than N group and H group(P<0.01).The serum concentration of TG in HE groupwas extremely lower than N group and H group(P<0.01).The serum concentration of LDL-C in N group was extremely higher thanHE group(P<0.01).The serum concentration of HDL-C in N group was extremely lower than H group(P<0.01).Conclusion Hypoxiaand hypoxia exercise may negatively regulate the levels of PPARγby inhibiting miR-27 in the obese rats’liver,thereby affecting theexpression of downstream target genes CYP7A1 and CD36,and promoting cholesterol,fatty acid oxidation and HDL-C transport inthe liver,and ultimately the lipid levels in obese rats were improved.The effect of hypoxia exercise on improving blood lipid isbetter than simple hypoxia intervention.展开更多
Hypobaric hypoxia is the main environmental feature of the Tibetan plateau which would influence the efficiency of human metabolic heat production and the ability of thermal regulation.In order to understand the influ...Hypobaric hypoxia is the main environmental feature of the Tibetan plateau which would influence the efficiency of human metabolic heat production and the ability of thermal regulation.In order to understand the influence of the hypoxic environment on the plateau on the thermal comfort of short-term sojourners in Tibet,China,oxygen generators were used to create oxygen-enriched environments,and physiological and psychological reactions of subjects were compared under different oxygen partial pressures(p_(O_(2)))and air temperatures(t_(a)).The results showed that subjects’thermal sensation,thermal comfort and mean skin temperature decreased with a decrease in the oxygen partial pressure.When t_(a)=17℃,the influence of oxygen partial pressure was more pronounced,compared to p_(O_(2))=16.4 kPa,the thermal sensation of subjects under p_(O_(2))=13.7 kPa decreased by 33%.The rate of subjects feeling comfortable decreased by 25%,and the mean skin temperature decreased by 0.7℃.The hypoxic environment of the plateau exacerbates human discomfort.Therefore,it is necessary to fully understand the actual thermal requirements of sojourners in Tibet,China.The results of this study would have implications for a better understanding of thermal comfort characteristics in the hypoxia environment in plateau.展开更多
OBJECTIVE 3,5-Dimethoxy-4-(2-amino-3-prop-2-ynylsulfanyl-propionyl)-benzoic acid 4-guanidino-butyl ester(ZYZ451)showed excellent cardio-protective effects in our previous work.However,its therapeutic potential in vivo...OBJECTIVE 3,5-Dimethoxy-4-(2-amino-3-prop-2-ynylsulfanyl-propionyl)-benzoic acid 4-guanidino-butyl ester(ZYZ451)showed excellent cardio-protective effects in our previous work.However,its therapeutic potential in vivo and the mechanism remained to be elucidated.Herein,we evaluated cardiac protective role of ZYZ451 in post-myocardial infarction(post-MI)rats,and elucidated the underlying mechanism.METHODS Neonatal rat ventricular cardiomyoctys(NRVCs)were separated and subjected to pre-deoxidized(1%O2,5%CO2),and serum-free medium for 4h to obtain ischemic model.Mitochondrial ROS,MnSOD activity and cell apoptosis were tested to verify the cardiac protective effects of ZYZ451.Inhibitors and siRNA for Stat3 were used to determine role of Stat3 played in cardio-protective effectes of ZYZ451.Mitochondria were isolated from NRVCs to determine expression of Stat3 and MnSOD.Immunofluorescence and coimmunoprecipitation were conducted to determine the interaction between MnSOD and Stat3.To apply post-MI model in rats,the rats were subjected to ligation of LAD except for control group.The vehicle or ZYZ451(1,2or 5mg·kg-1)or mixture of Leonurine and SPRC(15mg·kg-1)was administered 7dbefore and 3more days after the operation.Area at risk(AAR),apoptosis in AAR,LDH and MDA levels,and MnSOD activity and expression were detected to evaluate the cardiac injury.Tissue mitochondria were isolated to determine MnSOD and Stat3 expression in ischemia,and coimmunoprecipitaion was performed to verify the interaction between MnSOD and Stat3 in vivo.RESULTS ZYZ451 prevented hypoxia induced NRVCs apoptosis via increasing MnSOD activity and inhibiting mitochondrial ROS production.Interestingly,5,15-DPP(STAT3phosphorylation inhibitor)failed to inhibit MnSOD activity,while knockout of STAT3 resulted in significant reduction of MnSOD activity,followed by increased mitochondrial ROS production and cardiomyocytes apoptosis in hypoxia.Moreover,protective effects of ZYZ451 were blunted in Stat3 deficient NRVCs.These results indicated the necessity of Stat3 on MnSOD activity independent of its transcriptional activity.We further found co-localization of STAT3 and MnSOD by immunofluorescence in NRVCs,coimmunoprecipitation verified their interaction,and ZYZ451 enhanced this interaction.Similar results were found on H9C2 cardiomyoctyes and knockout of STAT3 attenuated the interaction.Consistent with the in vitro results,ZYZ451 reduced myocardial infarct size,cell apoptosis,LDH and MDA content in myocardial infarction rats.The benefits relied on increased MnSOD activity and enhanced STAT3 and MnSOD interaction,as observed in dangerous area of the infracted hearts.CONCLUSION We are the first to report that STAT3 is involved in MnSOD activity regulation,and that ZYZ451 exerts its cardio-protective effects by enhancing MnSOD and STAT3 interaction.These findings indicate a new role for STAT3 beyond as a transcriptional factor and suggest that ZYZ451 is an effective cardioprotective agent.展开更多
OBJECTIVE This study discusses the effects of scutellarin(SCU),which is one of effective component of Erigeron breviscapus(Vant.)Hand-Mazz,on cGMP dependent protein kinase(PKG)in human cardiac microvascular endothelia...OBJECTIVE This study discusses the effects of scutellarin(SCU),which is one of effective component of Erigeron breviscapus(Vant.)Hand-Mazz,on cGMP dependent protein kinase(PKG)in human cardiac microvascular endothelial cells(HCMECs)after hypoxia roxygenation(HR).METHODS Based on a model of HCMECs cells with HR injury,cell viability is examined by MTT assay.Protein expression of PKG is analyzed by Western blotting and its enzyme activity is investigated by ELISA technology.RESULTS The results of MTT assay- indicate that SCU(1,10μmol·L1)could protect HCMECs against HR injury.SCU(0.1,1 and 10μmol·L-1)canenhance PKG-I expression in control and HR injury cells.Furthermore,SCU(1,10μmol·L-1 significantly increase PKG activity in control cells(P<0.01),and also SCU(100μmol·L-1)appears similar on enzyme activity in HR injury cells(P <0.05).CONCLUSION SCU appears protective effects on endothelial cells against HR damage.While its mechanisms may be related to the influence of SCU on PKG activity in HCMECs.展开更多
OBJECTIVE Hypoxia is associated with many complicated pathophysiological and biochemical processes that integrated and regulated via the key gene,protein and endogenous metabolite levels.Up to date,the exact molecular...OBJECTIVE Hypoxia is associated with many complicated pathophysiological and biochemical processes that integrated and regulated via the key gene,protein and endogenous metabolite levels.Up to date,the exact molecular mechanism of hypoxia still remains unclear.In this work,we further explore the molecular mechanism of hypoxia and adaption to attenuate the damage in zebrafish model that have potential to resist hypoxic environment.METHODS The hypoxic zebrafish model was established in different concentration of oxygen with 3%,5%,10%,21%in water.The brain tissue was separated and the RNA-seq was used to identify the differentially expressed genes.The related endogenous metabolites profiles were obtained by LC-HDMS,and the multivariate statistics was applied to discover the important metabolites candidates in hypoxic zebrafish.The candidates were searched in HMDB,KEGG and Lipid Maps databases.RESULTS The zebrafish hypoxic model was successfully constructed via the different concentration of oxygen,temperature and hypoxic time.The activities of the related hypoxic metabolic enzymes and factors including HIF-1a,actate dehydrogenase(LDH)and citrate synthase(CS)were evaluated.Significant differences(P<0.05 and fold change>2)in the expression of 422 genes were observed between the normal and 3% hypoxic model.Among them,201 genes increased depended on the lower concentration of oxygen.53 metabolites were identified that had significant difference between the hypoxia and control groups(P<0.05,fold change>1.5 and VIP>1.5).The ten key metabolites were increased gradually while six compounds were decreased.The endogenous hypoxic metabolites of phenylalanine,D-glucosamine-6P and several important lipids with the relevant hub genes had similar change in hypoxic model.In addition,the metabolic pathways of phenylalanine,glutamine and glycolipid were influenced in both the levels of genes and metabolites.CONCLUSION The up-regulation of phenylalanine,D-glucosamine-6P and lipid may have further understanding of protective effect in hypoxia.Our data provided an insight to further reveal the hypoxia and adaptation mechanism.展开更多
OBJECTIVE To investigated the role of SIRT6 in the survival of osteoblast cel s against hypoxia stimulus as wel as the underlying mechanism. METHODS MC3T3-E1 osteoblast cel s were used. Apoptosis was induced by hypoxi...OBJECTIVE To investigated the role of SIRT6 in the survival of osteoblast cel s against hypoxia stimulus as wel as the underlying mechanism. METHODS MC3T3-E1 osteoblast cel s were used. Apoptosis was induced by hypoxic treatment. MC3T3-E1 cells were transfected with adenovirus SIRT6. For SIRT6 silencing experiment,the transfection of cells were done using three si RNA duplexes directed at different regions of SIRT6 or scrambled siRNA pool. The relative levels of SIRT6 mR NA were quantifiedby using real-time PCR. Western blotting experiments were done after the specific treatment and sample collection. MTT assay was used to estimate cell viability. Caspase 3/7 activity was assayed. RESULTS The expression of SIRT6 mR NA appeared to be markedly down-regulated in the hypoxia-treated group compared to the matched normal group. Meanwhile,western blotting analysis revealed that the expression of SIRT6 level was markedly down-regulated in hypoxia-treated group at protein level. SIRT6 level was effectively down-regulated by the transfection of SIRT6 si RNA,and significantly enhanced by SIRT6 overexpression. Compared with the control group,SIRT6 overexpression could significantly increase cell viability,and significantly decrease the percentage of apoptotic cel s and the activity of caspase 3/7 in response to hypoxia treatment. By contrast,SIRT6 knockdown via treatment with SIRT6 si RNA exhibited the opposite phenotype. CONCLUSION These results suggest that SIRT6 plays a protective role in hypoxia-induced apoptosis in MC3T3-E1 cells,and that strategies might be beneficial for the treatment of ischemic bone disease.展开更多
OBJECTIVE Neocryptotanshinone(NCTS)is a natural product extracted from traditional Chinese herb Salvia miltiorrhiza Bunge.Previous studies have demonstrated the anti-inflammatory of NCTS in lipopolysaccharide(LPS)-sti...OBJECTIVE Neocryptotanshinone(NCTS)is a natural product extracted from traditional Chinese herb Salvia miltiorrhiza Bunge.Previous studies have demonstrated the anti-inflammatory of NCTS in lipopolysaccharide(LPS)-stimulated mouse macrophage(RAW 264.7).However,the protective effect and mechanism of NCTS in cardiomy⁃ocytes are still undefined.This study is to investigate whether NCTS exerts its cardioprotective effect against hypoxia/re⁃oxygenation(H/R)-induced H9C2 cell injury.METHODS The model of H/R injury was established through hypoxia for 8 h and reoxygenation for 12 h in H9C2 cardiomyocytes of rats.Cultured cardiomyocytes were randomly divided into four groups,control group,H/R group,H/R+NCTS pretreated group(1,2,5 and 10μmol·L^-1),and H/R+NCTS+HX531(an RXRαantagonist,2μmol·L^-1)co-treated group.The cell viability was measured by Cell Counting Kit-8,Hoechst33258 staining was used to observe the morphology of apoptotic changes.Mitochondrial membrane potential was detected by JC-1 fluorescent probe,and protein expressions of RXRα,Bcl-2,Bax,caspase-3 and cleaved caspase-3 with Western blotting.RESULTS Compared with control group,the cell viability in model group was decreased(P<0.05).After treated with NCTS in different concentrations,the CCK8 results showed that NCTS in 2μmol·L^-1 had protective effects.Result of Hoechst33258 staining suggested that the apoptosis was notably increased in model group(P<0.05),Meanwhile,the JC-1 results showed that the mitochondrial membrane potential of the model group decreased which was consistent with previous study.impressively,NCTS could restore the mitochondrial membrane potential as well as apoptosis.Fur⁃ther western blot experiments showed that NCTS treat could upregulate Bcl-2 protein,and downregulate the levels of Bax and cleaved caspase-3/caspase-3 ratio.Since RXRαis a critical upstreaming proteins which can directly mediate the apoptosis,we then determined the effect of NCTS on it.Intriguingly,RXRαwas notably activated by NCTS,while the HX531,the antagonist of RXRα,could abolished NCTS'effect when co-treated with NCTS.CONCLUSION NCTS in 2μmol·L^-1 was effective to protect H9C2 cell from H/R-induced cell injury through RXRα-mediated mitochondria apop⁃tosis.Current results provide possible drugs for the treatment of ischemic cardiomyopathy.展开更多
Hypoxia was a prominent feature of hepatocellular carcinoma cells （HCC）, contributing to therapeutic resistance towards a variety chemotherapeutic agents including Topoisomerase I inhibitor SN38, with mechanism not...Hypoxia was a prominent feature of hepatocellular carcinoma cells （HCC）, contributing to therapeutic resistance towards a variety chemotherapeutic agents including Topoisomerase I inhibitor SN38, with mechanism not yet fully understood, thus remaining a major clinical challenge. Herein, we present evidences that the hypoxia-in- duced nuclear translocation and accumulation of Yes-associated protein （YAP） acts as a survival input to promote hypoxic-resistance to SN38 in HCC. YAP induction by hypoxia was not mediated by HIF-lα, since the manipula- tion of HIF-1α either by COC12, exogenous expression nor siRNA of HIF-1α imposed any effect on the phosphoryla- tion or total level of YAP. Instead, mevalonate-HMG-CoA reductase （HMGCR） pathway may modulate the YAP pathway under hypoxia. Combined YAP inhibition by either siRNA or HMGCR inhibitor statins with SN38 achieved improved anti-cancer activities in HCC cells. Moreover, the increased anti-cancer efficacy of statins combined with irinotecan （the prodrug of SN-38 ） was further validated in a human HCC HepG2 xenografl model in nude mice. Taken together, our findings identify YAP as a novel mechanism of hypoxic-resistance to SN38. These results un- veil the combined suppression of YAP （ for instance , statins） and SN38 as a potential promising strategy to enhance treatment response of HCC patients, particularly those with advanced stage suffering from hypoxic resistance.展开更多
Background： Hypoxia tolerance studies in cotton are very rare in Pakistan. Unpredicted and excessive rainfalls result in severe losses to cotton crop in many regions of the country due to lack of hypoxia tolerance in...Background： Hypoxia tolerance studies in cotton are very rare in Pakistan. Unpredicted and excessive rainfalls result in severe losses to cotton crop in many regions of the country due to lack of hypoxia tolerance in current cotton varieties. The genotypes that can tolerate flooding are not reported earlier. The studies were conducted to explore hypoxia tolerance in local germplasm which will help to develop hypoxia tolerant cotton varieties. Method： An experiment with randomized complete different cotton varieties. The genotypes were given conditions. blocks was designed to study the hypoxia tolerance in two treatments i.e., water logged and non-water logged Results： The genotypes showed significant variability for yield, fiber and physiological traits. The hypoxia studies revealed that there is significant reduction for plant height in water sensitive genotype LRA-5166. The genotype MNH-786 showed better yield and MNH-556 showed superior ginning outturn percentage under water logged conditions. Staple length, strength and micronaire values also decreased under hypoxia. Similar pattern of negative effects were observed for Chlorophyll a, b contents and chl a/b ratio. Two hypoxia tolerant cultivars CIM-573 and MNH-564 had significantly higher chlorophyll a （1.664, 1.551） than other cultivars under both normal and waterlogged conditions. There was a significant decrease in total free amino acids in all genotypes/cultivars due to waterlogging. Free amino acid contents were significantly higher in two waterlogging sensitive cultivars, CEDIX and N-KRISHMA, than other cultivars under both non-waterlogged and waterlogged conditions. Waterlogging caused a significant reduction in shoot soluble proteins and increase in shoot proline. The genotype LRA-5166 was the highest in shoot soluble proteins content and showed significant decrease in shoot proline. Conclusions： With respect to yield MNH-786 showed better results and regarding ginning outturn percentage MNH-556 exhibited superior performance. The genotypes CIM-573 and MNH-564 showed higher chlorophyll a values. The above said genotypes may be exploited for further studies related to hypoxia tolerance.展开更多
OBJECTIVE To explorethe correlation betweenhypoxiaand insulin resistance bythe blood gas index in high-fat diets-induced obese rat model.METHODS 36% of high-fat diets were fed to SD male rats for 12 weeks.The model gr...OBJECTIVE To explorethe correlation betweenhypoxiaand insulin resistance bythe blood gas index in high-fat diets-induced obese rat model.METHODS 36% of high-fat diets were fed to SD male rats for 12 weeks.The model group was divided into IR group and non-IR group with the HOMA-IR index of the 12th week,and the abdominal aorta blood was taken for blood gas analysis.RESULTS The HOMA-IR index,Hct,ctHb and ctO_2 in IR group were significantly higher than those in normal group andnon-IR group(P>0.05),simultaneously no significant difference in pO_2,pCO_2 and sO_2 between tree groups.CONCLUSION Circulating blood of obese rat with insulin resistance is normoxia,accompanied by higher Hct,tHb and ctO_2,which may be due to the higher blood viscositand the selfregulation of chronic hypoxia in the body.展开更多
文摘Objective To explore the sequential effects of hypoxic exercising on miR-27/PPARγand lipid metabolism targetgene and protein expression levels in the obesity rats’liver.Methods 13-week-old male diet-induced obesity rats were randomlydivided into three groups(n=10):normal oxygen concentration quiet group(N),hypoxia quiet group(H),hypoxic exercise group(HE).Exercise training on the horizontal animal treadmill for 1 h/d,5 d/week for a total of 4 week,and the intensity of horizontaltreadmill training was 20 m/min(hypoxic concentration was 13.6%).Comparison of the weights of perirenal fat and epididymal fat in rats across different groups and calculation of Lee’s index based on body weight and body length of rats in each group were done.And the serum concentrations of total cholesterol(TC),triglyceride(TG),low density lipoprotein cholesterol(LDL-C),high-densitylipoprotein cholesterol(HDL-C)levels were detected.RT-PCR and Western Blot were used to detect the levels of miR-27,PPARγ,CYP7A1 and CD36.Results Hypoxic exercise decreased the expression levels of miR-27 in the obese rats’liver,however,theexpression level of PPARγwas gradually increased.The expression levels of miR-27 in HE group were significantly lower than Ngroup(P<0.05).The expression levels of PPARγmRNA in N group were significantly lower than H group(P<0.05),especially lowerthan HE group(P<0.01).The protein expression of PPARγprotein in N group was significantly lower than that other groups(P<0.01).The expression of lipid metabolism-related genes and proteins increased in the obese rats’liver.The expression of CYP7A1mRNA in N group was significantly lower than H group(P<0.05),especially lower than HE group(P<0.01).The expression ofCYP7A1 protein in the obese rats’liver in N group was extremely lower than H group and HE group(P<0.01).The proteinexpression of CD36 in N group was significantly lower than that in HE group(P<0.05).Hypoxia exercise improved the relatedphysiological and biochemical indexes of lipid metabolism disorder.The perirenal fat weight of obese rats in HE group wasextremely lower than N group and H group(P<0.01),and the perirenal fat weight in N group was significantly higher than H group(P<0.05).The epididymal fat weight in N group was significantly higher than H group(P<0.05),and extremely higher than HEgroup(P<0.01).The Lee’s index in HE group was extremely lower than N group and H group(P<0.01).The serum concentration ofTC in obese rats in HE group was extremely lower than N group and H group(P<0.01).The serum concentration of TG in HE groupwas extremely lower than N group and H group(P<0.01).The serum concentration of LDL-C in N group was extremely higher thanHE group(P<0.01).The serum concentration of HDL-C in N group was extremely lower than H group(P<0.01).Conclusion Hypoxiaand hypoxia exercise may negatively regulate the levels of PPARγby inhibiting miR-27 in the obese rats’liver,thereby affecting theexpression of downstream target genes CYP7A1 and CD36,and promoting cholesterol,fatty acid oxidation and HDL-C transport inthe liver,and ultimately the lipid levels in obese rats were improved.The effect of hypoxia exercise on improving blood lipid isbetter than simple hypoxia intervention.
基金Project(U20A20311)supported by the State Key Program of National Natural Science Foundation of ChinaProject(52008329)supported by the National Natural Science Foundation of ChinaProject(2018BSHYDZZ14)supported by the Postdoctoral Research Foundation of Shaanxi Province,China。
文摘Hypobaric hypoxia is the main environmental feature of the Tibetan plateau which would influence the efficiency of human metabolic heat production and the ability of thermal regulation.In order to understand the influence of the hypoxic environment on the plateau on the thermal comfort of short-term sojourners in Tibet,China,oxygen generators were used to create oxygen-enriched environments,and physiological and psychological reactions of subjects were compared under different oxygen partial pressures(p_(O_(2)))and air temperatures(t_(a)).The results showed that subjects’thermal sensation,thermal comfort and mean skin temperature decreased with a decrease in the oxygen partial pressure.When t_(a)=17℃,the influence of oxygen partial pressure was more pronounced,compared to p_(O_(2))=16.4 kPa,the thermal sensation of subjects under p_(O_(2))=13.7 kPa decreased by 33%.The rate of subjects feeling comfortable decreased by 25%,and the mean skin temperature decreased by 0.7℃.The hypoxic environment of the plateau exacerbates human discomfort.Therefore,it is necessary to fully understand the actual thermal requirements of sojourners in Tibet,China.The results of this study would have implications for a better understanding of thermal comfort characteristics in the hypoxia environment in plateau.
基金The project supported by National Natural Science Foundation of China(81330080)Key laboratory program of the Education Commission of Shanghai Municipality(ZDSYS14005)Shanghai Committee of Science and Technology(14JC1401100)
文摘OBJECTIVE 3,5-Dimethoxy-4-(2-amino-3-prop-2-ynylsulfanyl-propionyl)-benzoic acid 4-guanidino-butyl ester(ZYZ451)showed excellent cardio-protective effects in our previous work.However,its therapeutic potential in vivo and the mechanism remained to be elucidated.Herein,we evaluated cardiac protective role of ZYZ451 in post-myocardial infarction(post-MI)rats,and elucidated the underlying mechanism.METHODS Neonatal rat ventricular cardiomyoctys(NRVCs)were separated and subjected to pre-deoxidized(1%O2,5%CO2),and serum-free medium for 4h to obtain ischemic model.Mitochondrial ROS,MnSOD activity and cell apoptosis were tested to verify the cardiac protective effects of ZYZ451.Inhibitors and siRNA for Stat3 were used to determine role of Stat3 played in cardio-protective effectes of ZYZ451.Mitochondria were isolated from NRVCs to determine expression of Stat3 and MnSOD.Immunofluorescence and coimmunoprecipitation were conducted to determine the interaction between MnSOD and Stat3.To apply post-MI model in rats,the rats were subjected to ligation of LAD except for control group.The vehicle or ZYZ451(1,2or 5mg·kg-1)or mixture of Leonurine and SPRC(15mg·kg-1)was administered 7dbefore and 3more days after the operation.Area at risk(AAR),apoptosis in AAR,LDH and MDA levels,and MnSOD activity and expression were detected to evaluate the cardiac injury.Tissue mitochondria were isolated to determine MnSOD and Stat3 expression in ischemia,and coimmunoprecipitaion was performed to verify the interaction between MnSOD and Stat3 in vivo.RESULTS ZYZ451 prevented hypoxia induced NRVCs apoptosis via increasing MnSOD activity and inhibiting mitochondrial ROS production.Interestingly,5,15-DPP(STAT3phosphorylation inhibitor)failed to inhibit MnSOD activity,while knockout of STAT3 resulted in significant reduction of MnSOD activity,followed by increased mitochondrial ROS production and cardiomyocytes apoptosis in hypoxia.Moreover,protective effects of ZYZ451 were blunted in Stat3 deficient NRVCs.These results indicated the necessity of Stat3 on MnSOD activity independent of its transcriptional activity.We further found co-localization of STAT3 and MnSOD by immunofluorescence in NRVCs,coimmunoprecipitation verified their interaction,and ZYZ451 enhanced this interaction.Similar results were found on H9C2 cardiomyoctyes and knockout of STAT3 attenuated the interaction.Consistent with the in vitro results,ZYZ451 reduced myocardial infarct size,cell apoptosis,LDH and MDA content in myocardial infarction rats.The benefits relied on increased MnSOD activity and enhanced STAT3 and MnSOD interaction,as observed in dangerous area of the infracted hearts.CONCLUSION We are the first to report that STAT3 is involved in MnSOD activity regulation,and that ZYZ451 exerts its cardio-protective effects by enhancing MnSOD and STAT3 interaction.These findings indicate a new role for STAT3 beyond as a transcriptional factor and suggest that ZYZ451 is an effective cardioprotective agent.
基金The project supported by National Natural Science Foundation of China(30960450,81373964,81173110and 81402991)Yunnan Provincial Science and Technology Department(2011FA022,2014FA010,2014IA033and 2014BC012)+1 种基金Shanghai Science&Technology Support Program(13431900401)National Science&Technology Major Project of China(2014ZX09301-306-03)
文摘OBJECTIVE This study discusses the effects of scutellarin(SCU),which is one of effective component of Erigeron breviscapus(Vant.)Hand-Mazz,on cGMP dependent protein kinase(PKG)in human cardiac microvascular endothelial cells(HCMECs)after hypoxia roxygenation(HR).METHODS Based on a model of HCMECs cells with HR injury,cell viability is examined by MTT assay.Protein expression of PKG is analyzed by Western blotting and its enzyme activity is investigated by ELISA technology.RESULTS The results of MTT assay- indicate that SCU(1,10μmol·L1)could protect HCMECs against HR injury.SCU(0.1,1 and 10μmol·L-1)canenhance PKG-I expression in control and HR injury cells.Furthermore,SCU(1,10μmol·L-1 significantly increase PKG activity in control cells(P<0.01),and also SCU(100μmol·L-1)appears similar on enzyme activity in HR injury cells(P <0.05).CONCLUSION SCU appears protective effects on endothelial cells against HR damage.While its mechanisms may be related to the influence of SCU on PKG activity in HCMECs.
基金supported by National Natural Science Foundation of China(81573683 and 81173121)
文摘OBJECTIVE Hypoxia is associated with many complicated pathophysiological and biochemical processes that integrated and regulated via the key gene,protein and endogenous metabolite levels.Up to date,the exact molecular mechanism of hypoxia still remains unclear.In this work,we further explore the molecular mechanism of hypoxia and adaption to attenuate the damage in zebrafish model that have potential to resist hypoxic environment.METHODS The hypoxic zebrafish model was established in different concentration of oxygen with 3%,5%,10%,21%in water.The brain tissue was separated and the RNA-seq was used to identify the differentially expressed genes.The related endogenous metabolites profiles were obtained by LC-HDMS,and the multivariate statistics was applied to discover the important metabolites candidates in hypoxic zebrafish.The candidates were searched in HMDB,KEGG and Lipid Maps databases.RESULTS The zebrafish hypoxic model was successfully constructed via the different concentration of oxygen,temperature and hypoxic time.The activities of the related hypoxic metabolic enzymes and factors including HIF-1a,actate dehydrogenase(LDH)and citrate synthase(CS)were evaluated.Significant differences(P<0.05 and fold change>2)in the expression of 422 genes were observed between the normal and 3% hypoxic model.Among them,201 genes increased depended on the lower concentration of oxygen.53 metabolites were identified that had significant difference between the hypoxia and control groups(P<0.05,fold change>1.5 and VIP>1.5).The ten key metabolites were increased gradually while six compounds were decreased.The endogenous hypoxic metabolites of phenylalanine,D-glucosamine-6P and several important lipids with the relevant hub genes had similar change in hypoxic model.In addition,the metabolic pathways of phenylalanine,glutamine and glycolipid were influenced in both the levels of genes and metabolites.CONCLUSION The up-regulation of phenylalanine,D-glucosamine-6P and lipid may have further understanding of protective effect in hypoxia.Our data provided an insight to further reveal the hypoxia and adaptation mechanism.
基金The project supported by grants from Shandong Provincial Natural Science Foundation,China(ZR2014CQ037)National Training Programs of Innovation and Entrepreneurship for Undergraduates,China(201610439244)National Natural Science Foundation of China(81400182)
文摘OBJECTIVE To investigated the role of SIRT6 in the survival of osteoblast cel s against hypoxia stimulus as wel as the underlying mechanism. METHODS MC3T3-E1 osteoblast cel s were used. Apoptosis was induced by hypoxic treatment. MC3T3-E1 cells were transfected with adenovirus SIRT6. For SIRT6 silencing experiment,the transfection of cells were done using three si RNA duplexes directed at different regions of SIRT6 or scrambled siRNA pool. The relative levels of SIRT6 mR NA were quantifiedby using real-time PCR. Western blotting experiments were done after the specific treatment and sample collection. MTT assay was used to estimate cell viability. Caspase 3/7 activity was assayed. RESULTS The expression of SIRT6 mR NA appeared to be markedly down-regulated in the hypoxia-treated group compared to the matched normal group. Meanwhile,western blotting analysis revealed that the expression of SIRT6 level was markedly down-regulated in hypoxia-treated group at protein level. SIRT6 level was effectively down-regulated by the transfection of SIRT6 si RNA,and significantly enhanced by SIRT6 overexpression. Compared with the control group,SIRT6 overexpression could significantly increase cell viability,and significantly decrease the percentage of apoptotic cel s and the activity of caspase 3/7 in response to hypoxia treatment. By contrast,SIRT6 knockdown via treatment with SIRT6 si RNA exhibited the opposite phenotype. CONCLUSION These results suggest that SIRT6 plays a protective role in hypoxia-induced apoptosis in MC3T3-E1 cells,and that strategies might be beneficial for the treatment of ischemic bone disease.
基金National Natural Science Foundation of China(81822049and 81673712)
文摘OBJECTIVE Neocryptotanshinone(NCTS)is a natural product extracted from traditional Chinese herb Salvia miltiorrhiza Bunge.Previous studies have demonstrated the anti-inflammatory of NCTS in lipopolysaccharide(LPS)-stimulated mouse macrophage(RAW 264.7).However,the protective effect and mechanism of NCTS in cardiomy⁃ocytes are still undefined.This study is to investigate whether NCTS exerts its cardioprotective effect against hypoxia/re⁃oxygenation(H/R)-induced H9C2 cell injury.METHODS The model of H/R injury was established through hypoxia for 8 h and reoxygenation for 12 h in H9C2 cardiomyocytes of rats.Cultured cardiomyocytes were randomly divided into four groups,control group,H/R group,H/R+NCTS pretreated group(1,2,5 and 10μmol·L^-1),and H/R+NCTS+HX531(an RXRαantagonist,2μmol·L^-1)co-treated group.The cell viability was measured by Cell Counting Kit-8,Hoechst33258 staining was used to observe the morphology of apoptotic changes.Mitochondrial membrane potential was detected by JC-1 fluorescent probe,and protein expressions of RXRα,Bcl-2,Bax,caspase-3 and cleaved caspase-3 with Western blotting.RESULTS Compared with control group,the cell viability in model group was decreased(P<0.05).After treated with NCTS in different concentrations,the CCK8 results showed that NCTS in 2μmol·L^-1 had protective effects.Result of Hoechst33258 staining suggested that the apoptosis was notably increased in model group(P<0.05),Meanwhile,the JC-1 results showed that the mitochondrial membrane potential of the model group decreased which was consistent with previous study.impressively,NCTS could restore the mitochondrial membrane potential as well as apoptosis.Fur⁃ther western blot experiments showed that NCTS treat could upregulate Bcl-2 protein,and downregulate the levels of Bax and cleaved caspase-3/caspase-3 ratio.Since RXRαis a critical upstreaming proteins which can directly mediate the apoptosis,we then determined the effect of NCTS on it.Intriguingly,RXRαwas notably activated by NCTS,while the HX531,the antagonist of RXRα,could abolished NCTS'effect when co-treated with NCTS.CONCLUSION NCTS in 2μmol·L^-1 was effective to protect H9C2 cell from H/R-induced cell injury through RXRα-mediated mitochondria apop⁃tosis.Current results provide possible drugs for the treatment of ischemic cardiomyopathy.
文摘Hypoxia was a prominent feature of hepatocellular carcinoma cells （HCC）, contributing to therapeutic resistance towards a variety chemotherapeutic agents including Topoisomerase I inhibitor SN38, with mechanism not yet fully understood, thus remaining a major clinical challenge. Herein, we present evidences that the hypoxia-in- duced nuclear translocation and accumulation of Yes-associated protein （YAP） acts as a survival input to promote hypoxic-resistance to SN38 in HCC. YAP induction by hypoxia was not mediated by HIF-lα, since the manipula- tion of HIF-1α either by COC12, exogenous expression nor siRNA of HIF-1α imposed any effect on the phosphoryla- tion or total level of YAP. Instead, mevalonate-HMG-CoA reductase （HMGCR） pathway may modulate the YAP pathway under hypoxia. Combined YAP inhibition by either siRNA or HMGCR inhibitor statins with SN38 achieved improved anti-cancer activities in HCC cells. Moreover, the increased anti-cancer efficacy of statins combined with irinotecan （the prodrug of SN-38 ） was further validated in a human HCC HepG2 xenografl model in nude mice. Taken together, our findings identify YAP as a novel mechanism of hypoxic-resistance to SN38. These results un- veil the combined suppression of YAP （ for instance , statins） and SN38 as a potential promising strategy to enhance treatment response of HCC patients, particularly those with advanced stage suffering from hypoxic resistance.
文摘Background： Hypoxia tolerance studies in cotton are very rare in Pakistan. Unpredicted and excessive rainfalls result in severe losses to cotton crop in many regions of the country due to lack of hypoxia tolerance in current cotton varieties. The genotypes that can tolerate flooding are not reported earlier. The studies were conducted to explore hypoxia tolerance in local germplasm which will help to develop hypoxia tolerant cotton varieties. Method： An experiment with randomized complete different cotton varieties. The genotypes were given conditions. blocks was designed to study the hypoxia tolerance in two treatments i.e., water logged and non-water logged Results： The genotypes showed significant variability for yield, fiber and physiological traits. The hypoxia studies revealed that there is significant reduction for plant height in water sensitive genotype LRA-5166. The genotype MNH-786 showed better yield and MNH-556 showed superior ginning outturn percentage under water logged conditions. Staple length, strength and micronaire values also decreased under hypoxia. Similar pattern of negative effects were observed for Chlorophyll a, b contents and chl a/b ratio. Two hypoxia tolerant cultivars CIM-573 and MNH-564 had significantly higher chlorophyll a （1.664, 1.551） than other cultivars under both normal and waterlogged conditions. There was a significant decrease in total free amino acids in all genotypes/cultivars due to waterlogging. Free amino acid contents were significantly higher in two waterlogging sensitive cultivars, CEDIX and N-KRISHMA, than other cultivars under both non-waterlogged and waterlogged conditions. Waterlogging caused a significant reduction in shoot soluble proteins and increase in shoot proline. The genotype LRA-5166 was the highest in shoot soluble proteins content and showed significant decrease in shoot proline. Conclusions： With respect to yield MNH-786 showed better results and regarding ginning outturn percentage MNH-556 exhibited superior performance. The genotypes CIM-573 and MNH-564 showed higher chlorophyll a values. The above said genotypes may be exploited for further studies related to hypoxia tolerance.
基金supported by National Natural Science Foundation of China(81560744)
文摘OBJECTIVE To explorethe correlation betweenhypoxiaand insulin resistance bythe blood gas index in high-fat diets-induced obese rat model.METHODS 36% of high-fat diets were fed to SD male rats for 12 weeks.The model group was divided into IR group and non-IR group with the HOMA-IR index of the 12th week,and the abdominal aorta blood was taken for blood gas analysis.RESULTS The HOMA-IR index,Hct,ctHb and ctO_2 in IR group were significantly higher than those in normal group andnon-IR group(P>0.05),simultaneously no significant difference in pO_2,pCO_2 and sO_2 between tree groups.CONCLUSION Circulating blood of obese rat with insulin resistance is normoxia,accompanied by higher Hct,tHb and ctO_2,which may be due to the higher blood viscositand the selfregulation of chronic hypoxia in the body.
