Glutathione is a key player in cellular redox homeostasis and, therefore, in the response to H2O2, but the factors regulating oxidation-activated glutathione synthesis are still unclear. We investigated H2O2-induced g...Glutathione is a key player in cellular redox homeostasis and, therefore, in the response to H2O2, but the factors regulating oxidation-activated glutathione synthesis are still unclear. We investigated H2O2-induced glutathione synthesis in a conditional Arabidopsis catalase-deficient mutant （cat2）. Plants were grown from seed at elevated CO2 for 5 weeks, then transferred to air in either short-day or long-day conditions. Compared to cat2 at elevated CO2 or wild-type plants in any condition, transfer of cat2 to air in both photoperiods caused measurable oxidation of the leaf glutathione pool within hours. Oxidation continued on subsequent days and was accompanied by accumulation of glutathione. This effect was stronger in cat2 transferred to air in short days, and was not linked to appreciable increases in the extractable activities of or transcripts encoding enzymes involved in the committed pathway of glutathione synthesis. In contrast, it was accompanied by increases in serine, O-acetylserine, and cysteine. These changes in metabolites were accompanied by induction of genes encoding adenosine phosphosulfate reductase （APR）, particularly APR3, as well as a specific serine acetyltransferase gene （SAT2.1） encoding a chloroplastic SAT. Marked induction of these genes was only observed in cat2 transferred to air in short-day conditions, where cysteine and glutathione accumulation was most dramatic. Unlike other SAT genes, which showed negligible induction in cat2, the relative abundance of APR and SAT2.1 transcripts was closely correlated with marker transcripts for H2O2 signaling. Together, the data underline the importance of cysteine synthesis in oxidant-induced up-regulation of glutathione synthesis and suggest that the chloroplast makes an important contribution to cysteine production under these circumstances.展开更多
In recent years, signal transducers and activators of transcription (STAT) proteins have been recognized as cytoplasmic transcription factors that mediate extracellular signaling to the nucleus controlling fundamental...In recent years, signal transducers and activators of transcription (STAT) proteins have been recognized as cytoplasmic transcription factors that mediate extracellular signaling to the nucleus controlling fundamental functions, such as cell proliferation, apoptosis, differentiation, immune responses and angiogenesis. Among them, STAT3 is a major player, aberrant activation of which is involved in several diseases, including cancer. Among other upstream regulators, IL-6/Jak signaling can activate STAT3 and its role appears to be critical in various types of cancer. Although STAT3 has been traditionally recognized as amoncogene, more recently the dual role of STAT3 in cancer, either tumor inductive or suppressive, has been appreciated. The importance and differential effect of STAT3 on tyrosine or serine residues are also a matter of continuing debate. Interestingly, recent findings suggesting that STAT3 plays an important role in cancer stem cell regulation have gained significant attention. This review summarizes current literature focusing on the significance of STAT3 in several diseases as well as in cancer. Understanding the complexity of STAT3 function has the potential to elucidate important molecular aspects of cancer with significant therapeutic implications.展开更多
As confusion mounts over RNA isoforms involved in phenotypic plasticity,aberrant CpG methylation-mediated disruption of alternative splicing is increasingly recognized as a driver of intratumor heterogeneity(ITH).Prot...As confusion mounts over RNA isoforms involved in phenotypic plasticity,aberrant CpG methylation-mediated disruption of alternative splicing is increasingly recognized as a driver of intratumor heterogeneity(ITH).Protease serine 3(PRSS3),possessing four splice variants(PRSS3-SVs;PRSS3-V1—V4),is an indispensable trypsin that shows paradoxical effects on cancer development.Here,we found that PRSS3 transcripts and their isoforms were divergently expressed in lung cancer,exhibiting opposing functions and clinical outcomes,namely,oncogenic PRSS3-V1 and PRSS3-V2 versus tumorsuppressive PRSS3-V3,by targeting different downstream genes.We identified an intragenic CpG island(iCpGI)in PRSS3.Hypermethylation of iCpGI was mediated by UHRF1/DNMT1 complex interference with the binding of myeloid zinc finger 1(MZF1)to regulate PRSS3 transcription.The garlic-derived compound diallyl trisulfide cooperated with 5-aza-2'-deoxycytidine to exert antitumor effects in lung adenocarcinoma cells through site-specific iCpGI demethylation specifically allowing MZF1 to upregulate PRSS3-V3 expression.Epigenetic silencing of PRSS3-V3 via i CpGI methylation(iCpGIm)in BALF and tumor tissues was associated with early clinical progression in patients with lung cancer but not in those with squamous cell carcinoma or inflammatory disease.Thus,UHRF1/DNMT1—MZF1 axismodulated site-specific iCpGIm regulates divergent expression of PRSS3-SVs,conferring nongenetic functional ITH,with implications for early detection of lung cancer and targeted therapies.展开更多
OBJECTIVE:To explore the protective mechanisms of the Traditional Chinese Medicine Bushenhuoxue(BSHX)in a rat model of vascular dementia(VD).METHODS:A rat model of VD was developed using bilateral common carotid arter...OBJECTIVE:To explore the protective mechanisms of the Traditional Chinese Medicine Bushenhuoxue(BSHX)in a rat model of vascular dementia(VD).METHODS:A rat model of VD was developed using bilateral common carotid artery occlusion(BCCAO).Rats were administered BSHX(10.14 or 5.07 g/kg),nimodipine(11.06 mg/kg;positive control),or saline(control)by gavage daily for 30 d post-surgery.Learning and memory abilities were assessed using the Morris water maze.Morphological changes in the hippocampus were observed using light microscopy(hematoxylin and eosin staining)and transmission electron microscopy(TEM).The m RNA and protein expression levels of brain-derived neurotrophic factor(BDNF),tyrosine receptor kinase B(Trk B),phosphatidyl inositol 3-kinase(PI3 K),serine/threonine kinase(AKT),and c AMP response element binding protein(CREB)were measured by real-time polymerase chain reaction(RT-PCR)and Western blot,respectively.RESULTS:Compared with the sham group,rats with BCCAO exhibited impaired learning and memory abilities(Morris water maze)and showed abnormalities in neuronal morphology(light microscopy)and ultrastructure(TEM)in the hippocampus.They also had decreased m RNA and protein expressions of BDNF,Trk B,PI3 K,AKT,and CREB in hippocampal tissue(all P<0.05).In rats with BCCAO,administration of BSHX attenuated deficits in learning and memory,improved the morphology and ultrastructure of hippocampal neurons,and enhanced m RNA and protein expression levels of BDNF,Trk B,PI3 K,AKT,and CREB(all P<0.05).CONCLUSION:BSHX may protect hippocampal neurons and improve learning and memory abilities,at least in part via the activation of BDNF/Trk B/PI3 K/AKT/CREB signaling.展开更多
AIM: To explore the effects and mechanisms of mechanical stress and transforming growth factor-beta2(TGF-β2) on epithelial-mesenchymal transition(EMT) in cultured human retinal pigment epithelial(RPE) cells. METHODS:...AIM: To explore the effects and mechanisms of mechanical stress and transforming growth factor-beta2(TGF-β2) on epithelial-mesenchymal transition(EMT) in cultured human retinal pigment epithelial(RPE) cells. METHODS: Human RPE cells were inoculated on BioF ex 6-well plates and RPE cells received 0, 1, 2, 3, or 4 mild stretch injuries delivered 3h apart after 24h of culture. The device of mechanical stress parameters were set to sine wave, frequency 1 Hz, stretch strength 20%. For treatment with TGF-β2, when the inoculated RPE cells in 6-well plates were around 60% confluent, serum was reduced to 0 for 12h and recombinant human TGF-β2(0, 1, 5, 10 ng/mL)was added for 48h. α-SMA, Vimentin and N-Cadherin, fibronectin proteins expressions were detected by Western blotting, confocal cell immunofluorescence and quantitative real-time polymerase chain reaction(q RT-PCR). Then we detected the change of mi RNA-29b and ascertained the changes of phosphatidylinositol 3-kinase-serine threonine protein kinase(PI3K/Akt) pathway after RPE cells were stretched by the device of mechanical stress and induced by TGF-β2 by Western blotting, confocal cell immunofluorescence and qR T-PCR. RESULTS: Mechanical stress induce EMT and activate the PI3K/Akt pathway in ways that lead to the EMT process. TGF-β2 induce RPE cells EMT and in a certain range and TGF-β2 decrease the miR NA-29b expression in RPE cells, and the inhibitory effect is more obvious with the increase of TGF-β2 concentration. CONCLUSION: Our findings are crucial steps in determining the critical roles of the PI3K/Akt signaling pathway and mi RNA-29b in pathogenesis of proliferative vitreoretinopathy(PVR) which may be a potential target for preventing or treating PVR.展开更多
文摘Glutathione is a key player in cellular redox homeostasis and, therefore, in the response to H2O2, but the factors regulating oxidation-activated glutathione synthesis are still unclear. We investigated H2O2-induced glutathione synthesis in a conditional Arabidopsis catalase-deficient mutant （cat2）. Plants were grown from seed at elevated CO2 for 5 weeks, then transferred to air in either short-day or long-day conditions. Compared to cat2 at elevated CO2 or wild-type plants in any condition, transfer of cat2 to air in both photoperiods caused measurable oxidation of the leaf glutathione pool within hours. Oxidation continued on subsequent days and was accompanied by accumulation of glutathione. This effect was stronger in cat2 transferred to air in short days, and was not linked to appreciable increases in the extractable activities of or transcripts encoding enzymes involved in the committed pathway of glutathione synthesis. In contrast, it was accompanied by increases in serine, O-acetylserine, and cysteine. These changes in metabolites were accompanied by induction of genes encoding adenosine phosphosulfate reductase （APR）, particularly APR3, as well as a specific serine acetyltransferase gene （SAT2.1） encoding a chloroplastic SAT. Marked induction of these genes was only observed in cat2 transferred to air in short-day conditions, where cysteine and glutathione accumulation was most dramatic. Unlike other SAT genes, which showed negligible induction in cat2, the relative abundance of APR and SAT2.1 transcripts was closely correlated with marker transcripts for H2O2 signaling. Together, the data underline the importance of cysteine synthesis in oxidant-induced up-regulation of glutathione synthesis and suggest that the chloroplast makes an important contribution to cysteine production under these circumstances.
文摘In recent years, signal transducers and activators of transcription (STAT) proteins have been recognized as cytoplasmic transcription factors that mediate extracellular signaling to the nucleus controlling fundamental functions, such as cell proliferation, apoptosis, differentiation, immune responses and angiogenesis. Among them, STAT3 is a major player, aberrant activation of which is involved in several diseases, including cancer. Among other upstream regulators, IL-6/Jak signaling can activate STAT3 and its role appears to be critical in various types of cancer. Although STAT3 has been traditionally recognized as amoncogene, more recently the dual role of STAT3 in cancer, either tumor inductive or suppressive, has been appreciated. The importance and differential effect of STAT3 on tyrosine or serine residues are also a matter of continuing debate. Interestingly, recent findings suggesting that STAT3 plays an important role in cancer stem cell regulation have gained significant attention. This review summarizes current literature focusing on the significance of STAT3 in several diseases as well as in cancer. Understanding the complexity of STAT3 function has the potential to elucidate important molecular aspects of cancer with significant therapeutic implications.
基金National Natural Science Foundation of China(NSFC grant No.32200462,China)National Natural Science Foundation of China(NSFC grant No.81872021,China)+4 种基金Beijing Municipal Administration of Hospitals Youth Program(grant No.QMS20221603,China)R&D Program of Beijing Municipal Education Commission(grant No.KM202110025004,China)Beijing Natural Science Foundation of China(BJSFC No.7214242,China)Beijing Municipal Administration of Hospitals Incubating Program(grant No.PX2021063,China)Intramural Research Funding Program from Beijing Tuberculosis and Thoracic Tumor Research Institute/Beijing Chest Hospital。
文摘As confusion mounts over RNA isoforms involved in phenotypic plasticity,aberrant CpG methylation-mediated disruption of alternative splicing is increasingly recognized as a driver of intratumor heterogeneity(ITH).Protease serine 3(PRSS3),possessing four splice variants(PRSS3-SVs;PRSS3-V1—V4),is an indispensable trypsin that shows paradoxical effects on cancer development.Here,we found that PRSS3 transcripts and their isoforms were divergently expressed in lung cancer,exhibiting opposing functions and clinical outcomes,namely,oncogenic PRSS3-V1 and PRSS3-V2 versus tumorsuppressive PRSS3-V3,by targeting different downstream genes.We identified an intragenic CpG island(iCpGI)in PRSS3.Hypermethylation of iCpGI was mediated by UHRF1/DNMT1 complex interference with the binding of myeloid zinc finger 1(MZF1)to regulate PRSS3 transcription.The garlic-derived compound diallyl trisulfide cooperated with 5-aza-2'-deoxycytidine to exert antitumor effects in lung adenocarcinoma cells through site-specific iCpGI demethylation specifically allowing MZF1 to upregulate PRSS3-V3 expression.Epigenetic silencing of PRSS3-V3 via i CpGI methylation(iCpGIm)in BALF and tumor tissues was associated with early clinical progression in patients with lung cancer but not in those with squamous cell carcinoma or inflammatory disease.Thus,UHRF1/DNMT1—MZF1 axismodulated site-specific iCpGIm regulates divergent expression of PRSS3-SVs,conferring nongenetic functional ITH,with implications for early detection of lung cancer and targeted therapies.
基金Supported by Hebei Province Natural Science Fund(Protection Mechanism Research of Bushenhuoxue on Hippocampal Nerve in Rats with Vascular Dementia Based on BDNF/Trk B Signaling Pathway,No.H2015423057)Hebei Provincial Department of Education Science and Technology Research Key Funding Project(Study on the Mechanism of Regulating the Autophagy and Apoptosis of Hippocampal Neurons in VD Rats by Bushenhuoxue Prescription,No.ZD2018009)Research Capacity Enhancement Project of Hebei University of Chinese Medicine(Improvement of Hippocampal Synaptic Remodeling in Rats with Vascular Dementia by Regulating BDNF/Trk B Signaling Pathway Based on the"renal essence"theory,No.2019-11).
文摘OBJECTIVE:To explore the protective mechanisms of the Traditional Chinese Medicine Bushenhuoxue(BSHX)in a rat model of vascular dementia(VD).METHODS:A rat model of VD was developed using bilateral common carotid artery occlusion(BCCAO).Rats were administered BSHX(10.14 or 5.07 g/kg),nimodipine(11.06 mg/kg;positive control),or saline(control)by gavage daily for 30 d post-surgery.Learning and memory abilities were assessed using the Morris water maze.Morphological changes in the hippocampus were observed using light microscopy(hematoxylin and eosin staining)and transmission electron microscopy(TEM).The m RNA and protein expression levels of brain-derived neurotrophic factor(BDNF),tyrosine receptor kinase B(Trk B),phosphatidyl inositol 3-kinase(PI3 K),serine/threonine kinase(AKT),and c AMP response element binding protein(CREB)were measured by real-time polymerase chain reaction(RT-PCR)and Western blot,respectively.RESULTS:Compared with the sham group,rats with BCCAO exhibited impaired learning and memory abilities(Morris water maze)and showed abnormalities in neuronal morphology(light microscopy)and ultrastructure(TEM)in the hippocampus.They also had decreased m RNA and protein expressions of BDNF,Trk B,PI3 K,AKT,and CREB in hippocampal tissue(all P<0.05).In rats with BCCAO,administration of BSHX attenuated deficits in learning and memory,improved the morphology and ultrastructure of hippocampal neurons,and enhanced m RNA and protein expression levels of BDNF,Trk B,PI3 K,AKT,and CREB(all P<0.05).CONCLUSION:BSHX may protect hippocampal neurons and improve learning and memory abilities,at least in part via the activation of BDNF/Trk B/PI3 K/AKT/CREB signaling.
基金Supported by the National Natural Science Foundation of China (No.81600754)
文摘AIM: To explore the effects and mechanisms of mechanical stress and transforming growth factor-beta2(TGF-β2) on epithelial-mesenchymal transition(EMT) in cultured human retinal pigment epithelial(RPE) cells. METHODS: Human RPE cells were inoculated on BioF ex 6-well plates and RPE cells received 0, 1, 2, 3, or 4 mild stretch injuries delivered 3h apart after 24h of culture. The device of mechanical stress parameters were set to sine wave, frequency 1 Hz, stretch strength 20%. For treatment with TGF-β2, when the inoculated RPE cells in 6-well plates were around 60% confluent, serum was reduced to 0 for 12h and recombinant human TGF-β2(0, 1, 5, 10 ng/mL)was added for 48h. α-SMA, Vimentin and N-Cadherin, fibronectin proteins expressions were detected by Western blotting, confocal cell immunofluorescence and quantitative real-time polymerase chain reaction(q RT-PCR). Then we detected the change of mi RNA-29b and ascertained the changes of phosphatidylinositol 3-kinase-serine threonine protein kinase(PI3K/Akt) pathway after RPE cells were stretched by the device of mechanical stress and induced by TGF-β2 by Western blotting, confocal cell immunofluorescence and qR T-PCR. RESULTS: Mechanical stress induce EMT and activate the PI3K/Akt pathway in ways that lead to the EMT process. TGF-β2 induce RPE cells EMT and in a certain range and TGF-β2 decrease the miR NA-29b expression in RPE cells, and the inhibitory effect is more obvious with the increase of TGF-β2 concentration. CONCLUSION: Our findings are crucial steps in determining the critical roles of the PI3K/Akt signaling pathway and mi RNA-29b in pathogenesis of proliferative vitreoretinopathy(PVR) which may be a potential target for preventing or treating PVR.
