The primary function of mitochondria is respiration, where catabolism of substrates is coupled to ATP synthesis via oxidative phosphorylation. In plants, mitochondrial composition is relatively complex and flexible an...The primary function of mitochondria is respiration, where catabolism of substrates is coupled to ATP synthesis via oxidative phosphorylation. In plants, mitochondrial composition is relatively complex and flexible and has specific pathways to support photosynthetic processes in illuminated leaves.展开更多
Recent technical advances in electrophysiological measurements, organelle-targeted fluorescence imaging, and organelle proteomics have pushed the research of ion transport a step forward in the case of the plant bioen...Recent technical advances in electrophysiological measurements, organelle-targeted fluorescence imaging, and organelle proteomics have pushed the research of ion transport a step forward in the case of the plant bioenergetic organelles, chloroplasts and mitochondria, leading to the molecular identification and functional characterization of several ion transport systems in recent years. Here we focus on channels that mediate relatively high-rate ion and water flux and summarize the current knowledge in this field, focusing on targeting mechanisms, proteomics, electrophysiology, and physiological function. In addition, since chloroplasts evolved from a cyanobacterial ancestor, we give an overview of the information available about cyanobacterial ion channels and discuss the evolutionary origin of chloroplast channels. The recent molecular identification of some of these ion channels allowed their physiological functions to be studied using genetically modified Arabidopsis plants and cyanobacteria. The view is emerging that alteration of chloroplast and mitochondrial ion homeostasis leads to organelle dysfunction, which in turn significantly affects the energy metabolism of the whole organism. Clear-cut identification of genes encoding for chan- nels in these organelles, however, remains a major challenge in this rapidly developing field. Multiple stra- tegies including bioinformatics, cell biology, electrophysiology, use of organelle-targeted ion-sensitive probes, genetics, and identification of signals eliciting specific ion fluxes across organelle membranes should provide a better understanding of the physiological role of organellar channels and their contribution to signaling pathways in plants in the future.展开更多
OBJECTIVE： To investigate the effects of resveratrol （RV） in reprogramming mouse embryonic fibroblasts （MEFs） into induced pluripotent stem cells （iPSCs） and the related mechanism. METHODS： Primary MEFs were i...OBJECTIVE： To investigate the effects of resveratrol （RV） in reprogramming mouse embryonic fibroblasts （MEFs） into induced pluripotent stem cells （iPSCs） and the related mechanism. METHODS： Primary MEFs were isolated from E13.5 embryos and used within three passages. Retroviruses expressing Sox2 and Oct4 were produced by transfecting GP2-293t cells with recombinant plasmids murine stern cell virus （MSCV）-Sox2 and MSCV-Oct4. Supernatants containing retroviruses were obtained after 48-hour transfection and MEFs were then infected. Different concentrations （0, 5, 10 and 20 IJmol/L） of RV were added to embryonic stem cell （ESC） medium to culture MEFs 48 h post-infection, iPSC clones emerged and were further cultured. Expression of pluripotent markers of iPSCs was identified by cell immunofluorescence and reverse transcription-polymerase chain reaction. Both cytotoxicity and cell proliferation were assayed by Western blot analysis after RV was added into ESC medium. The ultrastructure change of mitochondria was observed by electron microscopy. RESULTS： More than 2.9-fold and 1.3-fold increases in colony number were observed by treatment with RV at 5 and 10 pmol/L, respectively. The reprogramming efficiency was significantly decreased by treatment with 20 pmol/L RV. The proliferation effect on MEFs or MEFs infected by two factors Sox2/Oct4 （2 factors-MEFs, 2F-MEFs） was investigated after RV treatment. At 20 pmol/L RV, induced cell apoptosis and proliferation inhibition were more obvious than those of 5 and 10 IJmol/L treatments. Clones were selected from the 10 pmol/L RV-treated group and cultured. Green fluorescent protein expression from one typical clone was silenced one month later which expressed ESC-associated marker genes Gdf3, Nanog, Ecatl, Fgf4 and Foxd3. Electron transmission microscope showed obvious cavitations in mitochondria. The expression of hypoxia-inducible factor-la was up-regulated when 2F-MEFs were treated with RV compared to the control group. CONCLUSION： RV improved the efficiency of reprogramming 2F-MEFs into iPSCs at low and moderate concentrations （5 and 10 pmol/L）. The effect of 10 pmol/L RV on reprogramming was much greater than that of 5 pmol/L RV. However, high concentration of RV （20 pmol/L） led to more severe cavitations in mitochondria and caused cytotoxic effects. Taken together, these findinqs suqclest that RV mimics hypoxia in cells and promotes reprogramming at a low concentration.展开更多
基金supported by the Australian Research Council (ARC) ARC Centre of Excellence for Plant Energy Biology(CE0561495)RPJ is supported by a Grains Research and Development Corporation (GRDC) PhD scholarship+1 种基金LL was funded by Scholarship International Research Fees (SIRF),University International Stipend (UIS) and a Top Up Scholarship for UISAHM is supported by the Australian Research Council(ARC) as an ARC Future Fellow
文摘The primary function of mitochondria is respiration, where catabolism of substrates is coupled to ATP synthesis via oxidative phosphorylation. In plants, mitochondrial composition is relatively complex and flexible and has specific pathways to support photosynthetic processes in illuminated leaves.
文摘Recent technical advances in electrophysiological measurements, organelle-targeted fluorescence imaging, and organelle proteomics have pushed the research of ion transport a step forward in the case of the plant bioenergetic organelles, chloroplasts and mitochondria, leading to the molecular identification and functional characterization of several ion transport systems in recent years. Here we focus on channels that mediate relatively high-rate ion and water flux and summarize the current knowledge in this field, focusing on targeting mechanisms, proteomics, electrophysiology, and physiological function. In addition, since chloroplasts evolved from a cyanobacterial ancestor, we give an overview of the information available about cyanobacterial ion channels and discuss the evolutionary origin of chloroplast channels. The recent molecular identification of some of these ion channels allowed their physiological functions to be studied using genetically modified Arabidopsis plants and cyanobacteria. The view is emerging that alteration of chloroplast and mitochondrial ion homeostasis leads to organelle dysfunction, which in turn significantly affects the energy metabolism of the whole organism. Clear-cut identification of genes encoding for chan- nels in these organelles, however, remains a major challenge in this rapidly developing field. Multiple stra- tegies including bioinformatics, cell biology, electrophysiology, use of organelle-targeted ion-sensitive probes, genetics, and identification of signals eliciting specific ion fluxes across organelle membranes should provide a better understanding of the physiological role of organellar channels and their contribution to signaling pathways in plants in the future.
基金supported by the National Basic Research Program of China(973 Program,No.2010CB530400)the Key Project of National Natural Science Foundation of China(No.30930111)+3 种基金Changjiang Scholar Chair Professor Project(Teach people(2009) 17)Shanghai Education Innovation Project(No.08YZ56)"Shu Guang" project supported by Shanghai Municipal Education Commission and Shanghai Education Development Foundation(No.10GG20)Shanghai University Innovation Team Programmer(Shanghai Education Commission, Division 6(2009))
文摘OBJECTIVE： To investigate the effects of resveratrol （RV） in reprogramming mouse embryonic fibroblasts （MEFs） into induced pluripotent stem cells （iPSCs） and the related mechanism. METHODS： Primary MEFs were isolated from E13.5 embryos and used within three passages. Retroviruses expressing Sox2 and Oct4 were produced by transfecting GP2-293t cells with recombinant plasmids murine stern cell virus （MSCV）-Sox2 and MSCV-Oct4. Supernatants containing retroviruses were obtained after 48-hour transfection and MEFs were then infected. Different concentrations （0, 5, 10 and 20 IJmol/L） of RV were added to embryonic stem cell （ESC） medium to culture MEFs 48 h post-infection, iPSC clones emerged and were further cultured. Expression of pluripotent markers of iPSCs was identified by cell immunofluorescence and reverse transcription-polymerase chain reaction. Both cytotoxicity and cell proliferation were assayed by Western blot analysis after RV was added into ESC medium. The ultrastructure change of mitochondria was observed by electron microscopy. RESULTS： More than 2.9-fold and 1.3-fold increases in colony number were observed by treatment with RV at 5 and 10 pmol/L, respectively. The reprogramming efficiency was significantly decreased by treatment with 20 pmol/L RV. The proliferation effect on MEFs or MEFs infected by two factors Sox2/Oct4 （2 factors-MEFs, 2F-MEFs） was investigated after RV treatment. At 20 pmol/L RV, induced cell apoptosis and proliferation inhibition were more obvious than those of 5 and 10 IJmol/L treatments. Clones were selected from the 10 pmol/L RV-treated group and cultured. Green fluorescent protein expression from one typical clone was silenced one month later which expressed ESC-associated marker genes Gdf3, Nanog, Ecatl, Fgf4 and Foxd3. Electron transmission microscope showed obvious cavitations in mitochondria. The expression of hypoxia-inducible factor-la was up-regulated when 2F-MEFs were treated with RV compared to the control group. CONCLUSION： RV improved the efficiency of reprogramming 2F-MEFs into iPSCs at low and moderate concentrations （5 and 10 pmol/L）. The effect of 10 pmol/L RV on reprogramming was much greater than that of 5 pmol/L RV. However, high concentration of RV （20 pmol/L） led to more severe cavitations in mitochondria and caused cytotoxic effects. Taken together, these findinqs suqclest that RV mimics hypoxia in cells and promotes reprogramming at a low concentration.
