The mitogen-activated protein kinase （MAPK） cell signal transduction pathways play a key role in determining the survival of cells. If these pathways can be controlled, they will prohibit the proliferation of cancer...The mitogen-activated protein kinase （MAPK） cell signal transduction pathways play a key role in determining the survival of cells. If these pathways can be controlled, they will prohibit the proliferation of cancer cells. To attain this goal, the authors utilize many drugs to interact with mitogen-activated protein kinase kinase-1 （MEK1） in MAPK, and use computer aided drug design （CADD） to analyze the ligand activities of proteins in MEKL The results show that in these drugs, the aromatic group in the terminal of the protein and the PHE209 will induce the stacking force, which is highly related to the actual activities of these drugs.展开更多
The mitogen-activated protein kinase（MAPK） signaling pathway plays an important role in the regulation of cell growth, proliferation, differentiation, transformation and death. Mitogen-activated protein kinase phosp...The mitogen-activated protein kinase（MAPK） signaling pathway plays an important role in the regulation of cell growth, proliferation, differentiation, transformation and death. Mitogen-activated protein kinase phosphatase 1（MKP1） has an inhibitory effect on the p38 MAPK and JNK pathways, but it is unknown whether it plays a role in Aβ-induced oxidative stress and neuronal inflammation. In this study, PC12 cells were infected with MKP1 sh RNA, MKP1 lentivirus or control lentivirus for 12 hours, and then treated with 0.1, 1, 10 or 100 μM amyloid beta 42（Aβ42）. The cell survival rate was measured using the cell counting kit-8 assay. MKP1, tumor necrosis factor-alpha（TNF-α） and interleukin-1β（IL-1β） m RNA expression levels were analyzed using quantitative real time-polymerase chain reaction. MKP1 and phospho-c-Jun N-terminal kinase（JNK） expression levels were assessed using western blot assay. Reactive oxygen species（ROS） levels were detected using 2′,7′-dichlorofluorescein diacetate. Mitochondrial membrane potential was measured using flow cytometry. Superoxide dismutase activity and malondialdehyde levels were evaluated using the colorimetric method. Lactate dehydrogenase activity was measured using a microplate reader. Caspase-3 expression levels were assessed by enzyme-linked immunosorbent assay. Apoptosis was evaluated using the terminal deoxynucleotidyl transferase d UTP nick end labeling method. MKP1 overexpression inhibited Aβ-induced JNK phosphorylation and the increase in ROS levels. It also suppressed the Aβ-induced increase in TNF-α and IL-1β levels as well as apoptosis in PC12 cells. In contrast, MKP1 knockdown by RNA interference aggravated Aβ-induced oxidative stress, inflammation and cell damage in PC12 cells. Furthermore, the JNK-specific inhibitor SP600125 abolished this effect of MKP1 knockdown on Aβ-induced neurotoxicity. Collectively, these results show that MKP1 mitigates Aβ-induced apoptosis, oxidative stress and neuroinflammation by inhibiting the JNK signaling pathway, thereby playing a neuroprotective role.展开更多
BACKGROUND Enterotoxigenic Bacteroides fragilis(ETBF)causes colitis and diarrhea,and is considered a candidate pathogen in inflammatory bowel diseases as well as colorectal cancers.These diseases are dependent on ETBF...BACKGROUND Enterotoxigenic Bacteroides fragilis(ETBF)causes colitis and diarrhea,and is considered a candidate pathogen in inflammatory bowel diseases as well as colorectal cancers.These diseases are dependent on ETBF-secreted toxin(BFT).Dendritic cells(DCs)play an important role in directing the nature of adaptive immune responses to bacterial infection and heme oxygenase-1(HO-1)is involved in the regulation of DC function.AIM To investigate the role of BFT in HO-1 expression in DCs.METHODS Murine DCs were generated from specific pathogen-free C57BL/6 and Nrf2−/−knockout mice.DCs were exposed to BFT,after which HO-1 expression and the related signaling factor activation were measured by quantitative RT-PCR,EMSA,fluorescent microscopy,immunoblot,and ELISA.RESULTS HO-1 expression was upregulated in DCs stimulated with BFT.Although BFT activated transcription factors such as NF-κB,AP-1,and Nrf2,activation of NF-κB and AP-1 was not involved in the induction of HO-1 expression in BFT-exposed DCs.Instead,upregulation of HO-1 expression was dependent on Nrf2 activation in DCs.Moreover,HO-1 expression via Nrf2 in DCs was regulated by mitogenactivated protein kinases such as ERK and p38.Furthermore,BFT enhanced the production of reactive oxygen species(ROS)and inhibition of ROS production resulted in a significant decrease of phospho-ERK,phospho-p38,Nrf2,and HO-1 CONCLUSION These results suggest that signaling pathways involving ROS-mediated ERK and p38 mitogen-activated protein kinases-Nrf2 activation in DCs are required for HO-1 induction during exposure to ETBF-produced BFT.展开更多
The mitogen-activated protein kinase（MAPK）pathways are a group of conserved intracellular signalling pathways present in most cells including neurons and glia.These pathways respond to a variety of stimuli including...The mitogen-activated protein kinase（MAPK）pathways are a group of conserved intracellular signalling pathways present in most cells including neurons and glia.These pathways respond to a variety of stimuli including growth factors,cytokines and oxidative stress to generate appropriate cellular responses such as modulation of gene expression,cell proliferation,differentiation and survival as well as the stress response（Korhonen and Moilanen,2014）.展开更多
目的:探讨白藜芦醇在酒精诱导的HepG2细胞凋亡中的调节能力,揭示白藜芦醇抗酒精性肝损伤的作用机制.方法:白藜芦醇预处理HepG2细胞24 h后,用酒精诱导凋亡的产生.MTT方法检测白藜芦醇处理组与非处理组HepG2细胞的细胞活力;用ELISA试剂盒...目的:探讨白藜芦醇在酒精诱导的HepG2细胞凋亡中的调节能力,揭示白藜芦醇抗酒精性肝损伤的作用机制.方法:白藜芦醇预处理HepG2细胞24 h后,用酒精诱导凋亡的产生.MTT方法检测白藜芦醇处理组与非处理组HepG2细胞的细胞活力;用ELISA试剂盒检测不同实验组的细胞内总超氧化物浓度(total superoxide)和细胞总抗氧化能力(oxygen radical antioxidant capacity,O R A C);同时检测了含半胱氨酸的天冬氨酸蛋白水解酶3(cysteine-requiring aspartate protease,Caspase3)蛋白表达及应用荧光倒置显微镜观察了吖啶橙(acridine orange,AO)/碘化丙啶(propidium iodide,PI)染色的细胞形态学改变;采用RT-PCR方法检测氧化应激调节凋亡通路中关键基因Caspase3,细胞外调节蛋白激酶(extracellular regulated protein kinases,ERK),ERK激酶(mitogen-activated protein kinase kinase,MEK)和沉默信息调节因子1(silent mating type information regulation 1,SIRT-1)mRNA的表达.结果:MTT结果显示,与对照组比较,25-100μmol/L白藜芦醇可有效对抗300 mmol/L酒精对HepG2引起的细胞不良反应使细胞保持较高的活力;AO/PI活细胞凋亡检测显示了酒精处理组有大量的橙色凋亡细胞,而白藜芦醇预处理组橙色细胞明显减少;Caspase3结果显示不同浓度的白藜芦醇均可以降低被酒精激活的Caspase3的活性,其Caspase3的活性降为2.12、1.46、0.90和0.75倍;细胞内总超氧化物浓度结果显示预处理100、50、25μmol/L白藜芦醇组含量明显低于酒精诱导组;而未经白藜芦醇预处理的酒精诱导组ORAC(45.26±2.75)明显低于100、50、25μmol/L白藜芦醇预处理组(65.74±1.64、68.14±6.06、70.81±6.35).RT-PCR结果显示,与300 mmol/L酒精比较,不同浓度白藜芦醇均可上调SIRT1与ERK mRNA表达量;50μmol/L和100μmol/L白藜芦醇均可明显上调MEK mRNA表达量;50μmol/L和100μmol/L白藜芦醇均可显著下调Caspase3基因mRNA的表达量.结论:本研究提示酒精可诱导氧化应激相关的凋亡产生,而白藜芦醇通过调节MEK/ERKSIRT1通路中基因的表达发挥抗凋亡作用从而削弱酒精诱导的氧化应激及凋亡的损伤作用.展开更多
文摘The mitogen-activated protein kinase （MAPK） cell signal transduction pathways play a key role in determining the survival of cells. If these pathways can be controlled, they will prohibit the proliferation of cancer cells. To attain this goal, the authors utilize many drugs to interact with mitogen-activated protein kinase kinase-1 （MEK1） in MAPK, and use computer aided drug design （CADD） to analyze the ligand activities of proteins in MEKL The results show that in these drugs, the aromatic group in the terminal of the protein and the PHE209 will induce the stacking force, which is highly related to the actual activities of these drugs.
文摘The mitogen-activated protein kinase（MAPK） signaling pathway plays an important role in the regulation of cell growth, proliferation, differentiation, transformation and death. Mitogen-activated protein kinase phosphatase 1（MKP1） has an inhibitory effect on the p38 MAPK and JNK pathways, but it is unknown whether it plays a role in Aβ-induced oxidative stress and neuronal inflammation. In this study, PC12 cells were infected with MKP1 sh RNA, MKP1 lentivirus or control lentivirus for 12 hours, and then treated with 0.1, 1, 10 or 100 μM amyloid beta 42（Aβ42）. The cell survival rate was measured using the cell counting kit-8 assay. MKP1, tumor necrosis factor-alpha（TNF-α） and interleukin-1β（IL-1β） m RNA expression levels were analyzed using quantitative real time-polymerase chain reaction. MKP1 and phospho-c-Jun N-terminal kinase（JNK） expression levels were assessed using western blot assay. Reactive oxygen species（ROS） levels were detected using 2′,7′-dichlorofluorescein diacetate. Mitochondrial membrane potential was measured using flow cytometry. Superoxide dismutase activity and malondialdehyde levels were evaluated using the colorimetric method. Lactate dehydrogenase activity was measured using a microplate reader. Caspase-3 expression levels were assessed by enzyme-linked immunosorbent assay. Apoptosis was evaluated using the terminal deoxynucleotidyl transferase d UTP nick end labeling method. MKP1 overexpression inhibited Aβ-induced JNK phosphorylation and the increase in ROS levels. It also suppressed the Aβ-induced increase in TNF-α and IL-1β levels as well as apoptosis in PC12 cells. In contrast, MKP1 knockdown by RNA interference aggravated Aβ-induced oxidative stress, inflammation and cell damage in PC12 cells. Furthermore, the JNK-specific inhibitor SP600125 abolished this effect of MKP1 knockdown on Aβ-induced neurotoxicity. Collectively, these results show that MKP1 mitigates Aβ-induced apoptosis, oxidative stress and neuroinflammation by inhibiting the JNK signaling pathway, thereby playing a neuroprotective role.
基金Supported by the Basic Science Research Program through the National Research Foundation of Korea funded by the Ministry of Education,Science and Technology,South Korea,No.NRF-2018R1D1A1B07043350
文摘BACKGROUND Enterotoxigenic Bacteroides fragilis(ETBF)causes colitis and diarrhea,and is considered a candidate pathogen in inflammatory bowel diseases as well as colorectal cancers.These diseases are dependent on ETBF-secreted toxin(BFT).Dendritic cells(DCs)play an important role in directing the nature of adaptive immune responses to bacterial infection and heme oxygenase-1(HO-1)is involved in the regulation of DC function.AIM To investigate the role of BFT in HO-1 expression in DCs.METHODS Murine DCs were generated from specific pathogen-free C57BL/6 and Nrf2−/−knockout mice.DCs were exposed to BFT,after which HO-1 expression and the related signaling factor activation were measured by quantitative RT-PCR,EMSA,fluorescent microscopy,immunoblot,and ELISA.RESULTS HO-1 expression was upregulated in DCs stimulated with BFT.Although BFT activated transcription factors such as NF-κB,AP-1,and Nrf2,activation of NF-κB and AP-1 was not involved in the induction of HO-1 expression in BFT-exposed DCs.Instead,upregulation of HO-1 expression was dependent on Nrf2 activation in DCs.Moreover,HO-1 expression via Nrf2 in DCs was regulated by mitogenactivated protein kinases such as ERK and p38.Furthermore,BFT enhanced the production of reactive oxygen species(ROS)and inhibition of ROS production resulted in a significant decrease of phospho-ERK,phospho-p38,Nrf2,and HO-1 CONCLUSION These results suggest that signaling pathways involving ROS-mediated ERK and p38 mitogen-activated protein kinases-Nrf2 activation in DCs are required for HO-1 induction during exposure to ETBF-produced BFT.
基金support from Science Foundation Ireland under grant No. SFI/IA/1537
文摘The mitogen-activated protein kinase（MAPK）pathways are a group of conserved intracellular signalling pathways present in most cells including neurons and glia.These pathways respond to a variety of stimuli including growth factors,cytokines and oxidative stress to generate appropriate cellular responses such as modulation of gene expression,cell proliferation,differentiation and survival as well as the stress response（Korhonen and Moilanen,2014）.
文摘目的:探讨白藜芦醇在酒精诱导的HepG2细胞凋亡中的调节能力,揭示白藜芦醇抗酒精性肝损伤的作用机制.方法:白藜芦醇预处理HepG2细胞24 h后,用酒精诱导凋亡的产生.MTT方法检测白藜芦醇处理组与非处理组HepG2细胞的细胞活力;用ELISA试剂盒检测不同实验组的细胞内总超氧化物浓度(total superoxide)和细胞总抗氧化能力(oxygen radical antioxidant capacity,O R A C);同时检测了含半胱氨酸的天冬氨酸蛋白水解酶3(cysteine-requiring aspartate protease,Caspase3)蛋白表达及应用荧光倒置显微镜观察了吖啶橙(acridine orange,AO)/碘化丙啶(propidium iodide,PI)染色的细胞形态学改变;采用RT-PCR方法检测氧化应激调节凋亡通路中关键基因Caspase3,细胞外调节蛋白激酶(extracellular regulated protein kinases,ERK),ERK激酶(mitogen-activated protein kinase kinase,MEK)和沉默信息调节因子1(silent mating type information regulation 1,SIRT-1)mRNA的表达.结果:MTT结果显示,与对照组比较,25-100μmol/L白藜芦醇可有效对抗300 mmol/L酒精对HepG2引起的细胞不良反应使细胞保持较高的活力;AO/PI活细胞凋亡检测显示了酒精处理组有大量的橙色凋亡细胞,而白藜芦醇预处理组橙色细胞明显减少;Caspase3结果显示不同浓度的白藜芦醇均可以降低被酒精激活的Caspase3的活性,其Caspase3的活性降为2.12、1.46、0.90和0.75倍;细胞内总超氧化物浓度结果显示预处理100、50、25μmol/L白藜芦醇组含量明显低于酒精诱导组;而未经白藜芦醇预处理的酒精诱导组ORAC(45.26±2.75)明显低于100、50、25μmol/L白藜芦醇预处理组(65.74±1.64、68.14±6.06、70.81±6.35).RT-PCR结果显示,与300 mmol/L酒精比较,不同浓度白藜芦醇均可上调SIRT1与ERK mRNA表达量;50μmol/L和100μmol/L白藜芦醇均可明显上调MEK mRNA表达量;50μmol/L和100μmol/L白藜芦醇均可显著下调Caspase3基因mRNA的表达量.结论:本研究提示酒精可诱导氧化应激相关的凋亡产生,而白藜芦醇通过调节MEK/ERKSIRT1通路中基因的表达发挥抗凋亡作用从而削弱酒精诱导的氧化应激及凋亡的损伤作用.
