Salidroside,the main active ingredient extracted from Rhodiola crenulata,has been shown to be neuroprotective in ischemic cerebral injury,but the underlying mechanism for this neuroprotection is poorly understood.In t...Salidroside,the main active ingredient extracted from Rhodiola crenulata,has been shown to be neuroprotective in ischemic cerebral injury,but the underlying mechanism for this neuroprotection is poorly understood.In the current study,the neuroprotective effect of salidroside on cerebral ischemia-induced oxidative stress and the role of the nuclear factor erythroid 2-related factor 2（Nrf2）pathway was investigated in a rat model of middle cerebral artery occlusion.Salidroside（30 mg/kg）reduced infarct size,improved neurological function and histological changes,increased activity of superoxide dismutase and glutathione-S-transferase,and reduced malon-dialdehyde levels after cerebral ischemia and reperfusion.Furthermore,salidroside apparently increased Nrf2 and heme oxygenase-1 expression.These results suggest that salidroside exerts its neuroprotective effect against cerebral ischemia through anti-oxidant mechanisms and that activation of the Nrf2 pathway is involved.The Nrf2/antioxidant response element pathway may become a new therapeutic target for the treatment of ischemic stroke.展开更多
BACKGROUND MicroRNA 34c(miR-34c)has been reported to be associated with malignant types of cancer,however,it remains unknown whether miR-34c is involved in chemoresistance in gastric cancer(GC).AIM To investigate the ...BACKGROUND MicroRNA 34c(miR-34c)has been reported to be associated with malignant types of cancer,however,it remains unknown whether miR-34c is involved in chemoresistance in gastric cancer(GC).AIM To investigate the effect of miR-34c and its upstream transcription factor E2F1 on paclitaxel combined with cisplatin resistance in GC cells.METHODS Paired GC tissues and adjacent normal tissues were randomly sampled from 74 GC patients.miR-34c and E2F1 were detected by real-time quantitative PCR(qPCR)and Western blot.In addition,the drug resistance of GC cells to paclitaxel and cisplatin was induced by concentration gradient increasing methods,and changes in miR-34c and E2F1 during this process were measured.Furthermore,E2F1 and miR-34c overexpression or underexpression vectors were constructed and transfected into drug-resistant GC cells.MTT was employed to test the sensitivity of cells to paclitaxel combined with cisplatin,qPCR was adopted to detect the expression of miR-34c,Western blot was applied to detect the expression levels of E2F1,drug resistance-related proteins and apoptosis-related proteins,and flow cytometry was used for the determination of cell apoptosis and cell cycle status.RESULTS E2F1 was overexpressed while miR-34c was underexpressed in GC.After inducing GC cells to be resistant to paclitaxel and cisplatin,E2F1 expression increased while miR-34c expression decreased.Both silencing E2F1 and overexpressing miR-34c could increase the sensitivity of drug-resistant GC cells to paclitaxel combined with cisplatin,promote cell apoptosis and inhibit cell proliferation.Among which,silencing E2F1 could reduce the expression of drug resistance-related proteins and apoptosis-related proteins,while over-expression of miR-34c could upregulate the expression of apoptosis-related proteins without affecting the expression of MDR-1,MRP and other drug resistance-related proteins.Rescue experiments demonstrated that inhibiting miR-34c could significantly weaken the sensitization of drug resistant cells,and Si E2F1 to paclitaxel combined with cisplatin.CONCLUSION E2F1 inhibits miR-34c to promote the proliferation of GC cells and enhance the resistance to paclitaxel combined with cisplatin,and silencing E2F1 is conducive to improving the efficacy of paclitaxel combined with cisplatin in GC cells.展开更多
This study aims to analyze the clinical significance and mechanism of nuclear factor erythroid 2-related factor 2(NRF2)and glutathione peroxidase 4(GPX4)in primary hepatic carcinoma(PHC).Methods:The expression of NRF2...This study aims to analyze the clinical significance and mechanism of nuclear factor erythroid 2-related factor 2(NRF2)and glutathione peroxidase 4(GPX4)in primary hepatic carcinoma(PHC).Methods:The expression of NRF2 and GPX4 in peripheral blood of patients with PHC was determined to analyze the diagnostic value of the two combined for PHC.The prognostic significance of NRF2 and GPX4 was evaluated by 3-year followup.Human liver epithelial cells THLE-2 and human hepatocellular carcinoma cells HepG2 were purchased,and the expression of NRF2 and GPX4 in the cells was determined.NRF2 and GPX4 aberrant expression vectors were constructed and transfected into HepG2,and changes in cell proliferation and invasion capabilities were observed.Results:The expression of NRF2 and GPX4 in patients with PHC was higher than that in patients with LC or VH(p<0.05),and the two indicators combined was excellent in diagnosing PHC.Moreover,patients with high expression of NRF2 and GPX4 had a higher risk of death(p<0.05).In in vitro experiments,both NRF2 and GPX4 expression was elevated in HepG2(p<0.05).HepG2 activity was enhanced by increasing the expression of the two,vice versa(p<0.05).Conclusion:NRF2 and GPX4 combined is excellent in diagnosing PHC,and promotes the malignant development of PHC.展开更多
OBJECTIVE Nuclear factor erythroid 2-related factor 2(Nrf2) is found to be ubiquitiously expressed in many tissues,and works as the key regulator against oxidative stress damage in cells and organs,which makes Nrf2 a ...OBJECTIVE Nuclear factor erythroid 2-related factor 2(Nrf2) is found to be ubiquitiously expressed in many tissues,and works as the key regulator against oxidative stress damage in cells and organs,which makes Nrf2 a widely concerned drug target.Recent research has identified that Nrf2 is involved in the pathology of Alzheimer disease(AD),whereas the mechanism is unknown.The purpose of this study is to figure out the role of Nrf2 in the pathologic process of AD through Nrf2-Keap1-ARE pathway and the effects of Keap1-Nrf2 inhibitor in AD mice models.METHODS Amyloid β^(1-42)(Aβ^(1-42))was injected into the bilateral hippocampus to induce the cognitive dysfunction in eight-week old male mice.The mice were treated with Keap1-Nrf2 inhibitor NXPZ of three doses as well as donepezil as a positive control by intragastric administration one time a day for one week.Several behavior tests were used to analyze the mice learning and memory ability.Additionally,we detected Nrf2 and Aβ in the plasma in mice with ELISA kits,as well as some factors related to oxidative stress in the hippocampus and cortex.The expression levels of Nrf2,Keap1,Tau and p-Tau were measured in the murine brain tissue with Western blotting.SH-SY5 Y cells were studied as an in vitro model to further clarify the mechanism.RESULTS The treatment of NXPZ ameliorated learning and memory dysfunction in AD mice in a dose-dependent manner,and the high dose group recovered better than the positive drug group.The plasma Nrf2 level was increased in a dose-dependent manner in the treatment groups;however,the plasma Aβ was decreased.What′ s more,superoxide dismutase(SOD) and glutathione reductase(GSSH) in the hippocampus and cortex were increased in the treatment group,while the malondialdehyde(MDA) was decreased,meaning that NXPZ treatment promoted expression of the anti-oxidative factors and inhibited the expression of the oxidative factors in the down-stream.Western blotting analysis of hippocampus and cortex showed up-regulated Nrf2,decreased Keap1 and decreased p-Tau in NXPZ treatment mice.In ex vivo experiments,when SH-SY5 Y cells were treated with Aβ,Nrf2 in the cytoplasm was increased,as well as the expression Nrf2 in the nuclear was decreased.The treatment of NXPZ increased nuclear Nrf2,decreased cytoplasm Nrf2,and decreased the expression of p-Tau.CONCLUSION Nrf2 has an important role in neuron function.Nrf2 activation by selective Keap1-Nrf2 inhibitor NXPZ may contribute to improve cognitive function in AD mice.The mechanism may be related to increased generation and release of Nrf2 induced by more disaggregation with Keap1,leading to more expression of anti-oxidative molecules to protect the damage caused by Aβ.These results indicates that Nrf2 may be a novel therapeutic target of AD and Keap1-Nrf2 inhibitor may be a novel medication for protecting the loss of learning and memory ability.展开更多
BACKGROUND A series of long non-coding RNAs(lncRNAs)have been reported to play a crucial role in cancer biology.Some previous studies report that lncRNA CDKN2B-AS1 is involved in some human malignancies.However,its ro...BACKGROUND A series of long non-coding RNAs(lncRNAs)have been reported to play a crucial role in cancer biology.Some previous studies report that lncRNA CDKN2B-AS1 is involved in some human malignancies.However,its role in hepatocellular carcinoma(HCC)has not been fully deciphered.AIM To decipher the role of CDKN2B-AS1 in the progression of HCC.METHODS CDKN2B-AS1 expression in HCC was detected by quantitative real-time polymerase chain reaction.The malignant phenotypes of Li-7 and SNU-182 cells were detected by the CCK-8 method,EdU method,and flow cytometry,respectively.RNA immunoprecipitation was executed to confirm the interaction between CDKN2B-AS1 and E2F transcription factor 1(E2F1).Luciferase reporter assay and chromatin immunoprecipitation were performed to verify the binding of E2F1 to the promoter of G protein subunit alpha Z(GNAZ).E2F1 and GNAZ were detected by western blot in HCC cells.RESULTS In HCC tissues,CDKN2B-AS1 was upregulated.Depletion of CDKN2B-AS1 inhibited the proliferation of HCC cells,and the depletion of CDKN2B-AS1 also induced cell cycle arrest and apoptosis.CDKN2B-AS1 could interact with E2F1.Depletion of CDKN2B-AS1 inhibited the binding of E2F1 to the GNAZ promoter region.Overexpression of E2F1 reversed the biological effects of depletion of CDKN2B-AS1 on the malignant behaviors of HCC cells.CONCLUSION CDKN2B-AS1 recruits E2F1 to facilitate GNAZ transcription to promote HCC progression.展开更多
Vitamin K2 (VK2, menaquinone) is a drug for osteoporosis. VK2 acts as a cofactor for γ-glutamyl carboxylase, which catalyzes the carboxylation of specific glutamic acid residues (γ-carboxylation) of substrate protei...Vitamin K2 (VK2, menaquinone) is a drug for osteoporosis. VK2 acts as a cofactor for γ-glutamyl carboxylase, which catalyzes the carboxylation of specific glutamic acid residues (γ-carboxylation) of substrate proteins. Here we demonstrate that VK2 also regulate osteoblastgenic marker gene expression. Using VK2-immobilzed nanobeads new target proteins were purified and identified from osteoblastic cell line. They are prohibitin 1 and 2 (PHB1 & 2), respectively. To confirm the PHBs function on VK2-dependent transcription, PHB1 & 2 were knock-down and osteocalcin gene 2 transcriptions were analyzed, indicating that PHBs regulate VK2-dependent transcription. Taken together PHBs are VK2 target proteins for osteoblastgenic transcription.展开更多
Estrogen receptors and E2F transcription factors are the key players of two nuclear signaling pathways which exert a major role in oncogenesis, particularly in the mammary gland. Different levels of dialogue between t...Estrogen receptors and E2F transcription factors are the key players of two nuclear signaling pathways which exert a major role in oncogenesis, particularly in the mammary gland. Different levels of dialogue between these two pathways have been deciphered and deregulation of the E2F pathway has been shown to impact the response of breast cancer cells to endocrine therapies. The present review focuses on the transcriptional coregulator RIP140/NRIP1 which is involved in several regulatory feed-back loops and inhibitory cross-talks between different nuclear signaling pathways. RIP140 regulates the transactivation potential of estrogen receptors and E2Fs and is also a direct transcriptional target of these transcription factors. Published data highlight the complex regulation of RIP140 expression at the transcriptional level and its potential role in transcription cross-talks. Indeed, a subtle regulation of RIP140 expression levels has important consequences on other transcription networks targeted by this coregulator. Another level of regulation implies titration mechanisms by which activation of a pathway leads to sequestration of the RIP140 protein and thus impinges other gene regulatory circuitries. Altogether, RIP140 occupies a place of choice in the dialogue between nuclear receptors and E2Fs, which could be highly relevant in various human pathologies such as cancer or metabolic diseases.展开更多
基金supported by the Independent Research Project of Fujian Academy of Traditional Chinese Medicine in China,No.2012fjzyyk-4the Natural Science Foundation of Fujian Province in China,No.2014J01340+1 种基金the Research Project of Fujian Provincial Health and Family Planning Commission,No.2014-ZQN-JC-32a grant from the Platform for Preclinical Studies of Traditional Chinese Medicine and Quality Control Engineering Technology Research Center of Fujian Province in China,No.2009Y2003
文摘Salidroside,the main active ingredient extracted from Rhodiola crenulata,has been shown to be neuroprotective in ischemic cerebral injury,but the underlying mechanism for this neuroprotection is poorly understood.In the current study,the neuroprotective effect of salidroside on cerebral ischemia-induced oxidative stress and the role of the nuclear factor erythroid 2-related factor 2（Nrf2）pathway was investigated in a rat model of middle cerebral artery occlusion.Salidroside（30 mg/kg）reduced infarct size,improved neurological function and histological changes,increased activity of superoxide dismutase and glutathione-S-transferase,and reduced malon-dialdehyde levels after cerebral ischemia and reperfusion.Furthermore,salidroside apparently increased Nrf2 and heme oxygenase-1 expression.These results suggest that salidroside exerts its neuroprotective effect against cerebral ischemia through anti-oxidant mechanisms and that activation of the Nrf2 pathway is involved.The Nrf2/antioxidant response element pathway may become a new therapeutic target for the treatment of ischemic stroke.
文摘BACKGROUND MicroRNA 34c(miR-34c)has been reported to be associated with malignant types of cancer,however,it remains unknown whether miR-34c is involved in chemoresistance in gastric cancer(GC).AIM To investigate the effect of miR-34c and its upstream transcription factor E2F1 on paclitaxel combined with cisplatin resistance in GC cells.METHODS Paired GC tissues and adjacent normal tissues were randomly sampled from 74 GC patients.miR-34c and E2F1 were detected by real-time quantitative PCR(qPCR)and Western blot.In addition,the drug resistance of GC cells to paclitaxel and cisplatin was induced by concentration gradient increasing methods,and changes in miR-34c and E2F1 during this process were measured.Furthermore,E2F1 and miR-34c overexpression or underexpression vectors were constructed and transfected into drug-resistant GC cells.MTT was employed to test the sensitivity of cells to paclitaxel combined with cisplatin,qPCR was adopted to detect the expression of miR-34c,Western blot was applied to detect the expression levels of E2F1,drug resistance-related proteins and apoptosis-related proteins,and flow cytometry was used for the determination of cell apoptosis and cell cycle status.RESULTS E2F1 was overexpressed while miR-34c was underexpressed in GC.After inducing GC cells to be resistant to paclitaxel and cisplatin,E2F1 expression increased while miR-34c expression decreased.Both silencing E2F1 and overexpressing miR-34c could increase the sensitivity of drug-resistant GC cells to paclitaxel combined with cisplatin,promote cell apoptosis and inhibit cell proliferation.Among which,silencing E2F1 could reduce the expression of drug resistance-related proteins and apoptosis-related proteins,while over-expression of miR-34c could upregulate the expression of apoptosis-related proteins without affecting the expression of MDR-1,MRP and other drug resistance-related proteins.Rescue experiments demonstrated that inhibiting miR-34c could significantly weaken the sensitization of drug resistant cells,and Si E2F1 to paclitaxel combined with cisplatin.CONCLUSION E2F1 inhibits miR-34c to promote the proliferation of GC cells and enhance the resistance to paclitaxel combined with cisplatin,and silencing E2F1 is conducive to improving the efficacy of paclitaxel combined with cisplatin in GC cells.
文摘This study aims to analyze the clinical significance and mechanism of nuclear factor erythroid 2-related factor 2(NRF2)and glutathione peroxidase 4(GPX4)in primary hepatic carcinoma(PHC).Methods:The expression of NRF2 and GPX4 in peripheral blood of patients with PHC was determined to analyze the diagnostic value of the two combined for PHC.The prognostic significance of NRF2 and GPX4 was evaluated by 3-year followup.Human liver epithelial cells THLE-2 and human hepatocellular carcinoma cells HepG2 were purchased,and the expression of NRF2 and GPX4 in the cells was determined.NRF2 and GPX4 aberrant expression vectors were constructed and transfected into HepG2,and changes in cell proliferation and invasion capabilities were observed.Results:The expression of NRF2 and GPX4 in patients with PHC was higher than that in patients with LC or VH(p<0.05),and the two indicators combined was excellent in diagnosing PHC.Moreover,patients with high expression of NRF2 and GPX4 had a higher risk of death(p<0.05).In in vitro experiments,both NRF2 and GPX4 expression was elevated in HepG2(p<0.05).HepG2 activity was enhanced by increasing the expression of the two,vice versa(p<0.05).Conclusion:NRF2 and GPX4 combined is excellent in diagnosing PHC,and promotes the malignant development of PHC.
基金National Natural Science Foundation of China(81703520).
文摘OBJECTIVE Nuclear factor erythroid 2-related factor 2(Nrf2) is found to be ubiquitiously expressed in many tissues,and works as the key regulator against oxidative stress damage in cells and organs,which makes Nrf2 a widely concerned drug target.Recent research has identified that Nrf2 is involved in the pathology of Alzheimer disease(AD),whereas the mechanism is unknown.The purpose of this study is to figure out the role of Nrf2 in the pathologic process of AD through Nrf2-Keap1-ARE pathway and the effects of Keap1-Nrf2 inhibitor in AD mice models.METHODS Amyloid β^(1-42)(Aβ^(1-42))was injected into the bilateral hippocampus to induce the cognitive dysfunction in eight-week old male mice.The mice were treated with Keap1-Nrf2 inhibitor NXPZ of three doses as well as donepezil as a positive control by intragastric administration one time a day for one week.Several behavior tests were used to analyze the mice learning and memory ability.Additionally,we detected Nrf2 and Aβ in the plasma in mice with ELISA kits,as well as some factors related to oxidative stress in the hippocampus and cortex.The expression levels of Nrf2,Keap1,Tau and p-Tau were measured in the murine brain tissue with Western blotting.SH-SY5 Y cells were studied as an in vitro model to further clarify the mechanism.RESULTS The treatment of NXPZ ameliorated learning and memory dysfunction in AD mice in a dose-dependent manner,and the high dose group recovered better than the positive drug group.The plasma Nrf2 level was increased in a dose-dependent manner in the treatment groups;however,the plasma Aβ was decreased.What′ s more,superoxide dismutase(SOD) and glutathione reductase(GSSH) in the hippocampus and cortex were increased in the treatment group,while the malondialdehyde(MDA) was decreased,meaning that NXPZ treatment promoted expression of the anti-oxidative factors and inhibited the expression of the oxidative factors in the down-stream.Western blotting analysis of hippocampus and cortex showed up-regulated Nrf2,decreased Keap1 and decreased p-Tau in NXPZ treatment mice.In ex vivo experiments,when SH-SY5 Y cells were treated with Aβ,Nrf2 in the cytoplasm was increased,as well as the expression Nrf2 in the nuclear was decreased.The treatment of NXPZ increased nuclear Nrf2,decreased cytoplasm Nrf2,and decreased the expression of p-Tau.CONCLUSION Nrf2 has an important role in neuron function.Nrf2 activation by selective Keap1-Nrf2 inhibitor NXPZ may contribute to improve cognitive function in AD mice.The mechanism may be related to increased generation and release of Nrf2 induced by more disaggregation with Keap1,leading to more expression of anti-oxidative molecules to protect the damage caused by Aβ.These results indicates that Nrf2 may be a novel therapeutic target of AD and Keap1-Nrf2 inhibitor may be a novel medication for protecting the loss of learning and memory ability.
文摘BACKGROUND A series of long non-coding RNAs(lncRNAs)have been reported to play a crucial role in cancer biology.Some previous studies report that lncRNA CDKN2B-AS1 is involved in some human malignancies.However,its role in hepatocellular carcinoma(HCC)has not been fully deciphered.AIM To decipher the role of CDKN2B-AS1 in the progression of HCC.METHODS CDKN2B-AS1 expression in HCC was detected by quantitative real-time polymerase chain reaction.The malignant phenotypes of Li-7 and SNU-182 cells were detected by the CCK-8 method,EdU method,and flow cytometry,respectively.RNA immunoprecipitation was executed to confirm the interaction between CDKN2B-AS1 and E2F transcription factor 1(E2F1).Luciferase reporter assay and chromatin immunoprecipitation were performed to verify the binding of E2F1 to the promoter of G protein subunit alpha Z(GNAZ).E2F1 and GNAZ were detected by western blot in HCC cells.RESULTS In HCC tissues,CDKN2B-AS1 was upregulated.Depletion of CDKN2B-AS1 inhibited the proliferation of HCC cells,and the depletion of CDKN2B-AS1 also induced cell cycle arrest and apoptosis.CDKN2B-AS1 could interact with E2F1.Depletion of CDKN2B-AS1 inhibited the binding of E2F1 to the GNAZ promoter region.Overexpression of E2F1 reversed the biological effects of depletion of CDKN2B-AS1 on the malignant behaviors of HCC cells.CONCLUSION CDKN2B-AS1 recruits E2F1 to facilitate GNAZ transcription to promote HCC progression.
文摘Vitamin K2 (VK2, menaquinone) is a drug for osteoporosis. VK2 acts as a cofactor for γ-glutamyl carboxylase, which catalyzes the carboxylation of specific glutamic acid residues (γ-carboxylation) of substrate proteins. Here we demonstrate that VK2 also regulate osteoblastgenic marker gene expression. Using VK2-immobilzed nanobeads new target proteins were purified and identified from osteoblastic cell line. They are prohibitin 1 and 2 (PHB1 & 2), respectively. To confirm the PHBs function on VK2-dependent transcription, PHB1 & 2 were knock-down and osteocalcin gene 2 transcriptions were analyzed, indicating that PHBs regulate VK2-dependent transcription. Taken together PHBs are VK2 target proteins for osteoblastgenic transcription.
文摘Estrogen receptors and E2F transcription factors are the key players of two nuclear signaling pathways which exert a major role in oncogenesis, particularly in the mammary gland. Different levels of dialogue between these two pathways have been deciphered and deregulation of the E2F pathway has been shown to impact the response of breast cancer cells to endocrine therapies. The present review focuses on the transcriptional coregulator RIP140/NRIP1 which is involved in several regulatory feed-back loops and inhibitory cross-talks between different nuclear signaling pathways. RIP140 regulates the transactivation potential of estrogen receptors and E2Fs and is also a direct transcriptional target of these transcription factors. Published data highlight the complex regulation of RIP140 expression at the transcriptional level and its potential role in transcription cross-talks. Indeed, a subtle regulation of RIP140 expression levels has important consequences on other transcription networks targeted by this coregulator. Another level of regulation implies titration mechanisms by which activation of a pathway leads to sequestration of the RIP140 protein and thus impinges other gene regulatory circuitries. Altogether, RIP140 occupies a place of choice in the dialogue between nuclear receptors and E2Fs, which could be highly relevant in various human pathologies such as cancer or metabolic diseases.
