Several studies have shown that activation of unfolded protein response and endoplasmic reticulum(ER)stress plays a crucial role in severe cerebral ischemia/reperfusion injury.Autophagy occurs within hours after cereb...Several studies have shown that activation of unfolded protein response and endoplasmic reticulum(ER)stress plays a crucial role in severe cerebral ischemia/reperfusion injury.Autophagy occurs within hours after cerebral ischemia,but the relationship between ER stress and autophagy remains unclear.In this study,we established experimental models using oxygen-glucose deprivation/reoxygenation in PC12 cells and primary neurons to simulate cerebral ischemia/reperfusion injury.We found that prolongation of oxygen-glucose deprivation activated the ER stress pathway protein kinase-like endoplasmic reticulum kinase(PERK)/eukaryotic translation initiation factor 2 subunit alpha(e IF2α)-activating transcription factor 4(ATF4)-C/EBP homologous protein(CHOP),increased neuronal apoptosis,and induced autophagy.Furthermore,inhibition of ER stress using inhibitors or by si RNA knockdown of the PERK gene significantly attenuated excessive autophagy and neuronal apoptosis,indicating an interaction between autophagy and ER stress and suggesting PERK as an essential target for regulating autophagy.Blocking autophagy with chloroquine exacerbated ER stress-induced apoptosis,indicating that normal levels of autophagy play a protective role in neuronal injury following cerebral ischemia/reperfusion injury.Findings from this study indicate that cerebral ischemia/reperfusion injury can trigger neuronal ER stress and promote autophagy,and suggest that PERK is a possible target for inhibiting excessive autophagy in cerebral ischemia/reperfusion injury.展开更多
MicroRNAs (miRNAs) are a specialized class of small silencing RNAs that regulate gene expression in eukaryotes.In plants,miRNAs negatively regulate target mRNAs containing a highly complementary sequence by either mRN...MicroRNAs (miRNAs) are a specialized class of small silencing RNAs that regulate gene expression in eukaryotes.In plants,miRNAs negatively regulate target mRNAs containing a highly complementary sequence by either mRNA cleavage or translational repression.As a model plant to study fleshy fruit ripening,miRNA studies in tomato have made great progress recently.MiRNAs were predicted to be involved in nearly all biological processes in tomato,particularly development,differentiation,and biotic and abiotic stress responses.Surprisingly,several miRNAs were verified to be involved in tomato fruit ripening and senescence.Recent studies suggest that miRNAs are related to host-virus interactions,which raises the possibility that miRNAs can be used as diagnostic markers for response to virus infection in tomato plants.In this review,we summarize our current knowledge systematically and advance future directions for miRNA research in tomato.展开更多
基金supported by the National Natural Science Foundation of China,Nos.82260245(to YX),81660207(to YX),81960253(to YL),82160268(to YL),U1812403(to ZG)Science and Technology Projects of Guizhou Province,Nos.[2019]1440(to YX),[2020]1Z067(to WH)+1 种基金Cultivation Foundation of Guizhou Medical University,No.[20NSP069](to YX)Excellent Young Talents Plan of Guizhou Medical University,No.(2022)101(to WH)。
文摘Several studies have shown that activation of unfolded protein response and endoplasmic reticulum(ER)stress plays a crucial role in severe cerebral ischemia/reperfusion injury.Autophagy occurs within hours after cerebral ischemia,but the relationship between ER stress and autophagy remains unclear.In this study,we established experimental models using oxygen-glucose deprivation/reoxygenation in PC12 cells and primary neurons to simulate cerebral ischemia/reperfusion injury.We found that prolongation of oxygen-glucose deprivation activated the ER stress pathway protein kinase-like endoplasmic reticulum kinase(PERK)/eukaryotic translation initiation factor 2 subunit alpha(e IF2α)-activating transcription factor 4(ATF4)-C/EBP homologous protein(CHOP),increased neuronal apoptosis,and induced autophagy.Furthermore,inhibition of ER stress using inhibitors or by si RNA knockdown of the PERK gene significantly attenuated excessive autophagy and neuronal apoptosis,indicating an interaction between autophagy and ER stress and suggesting PERK as an essential target for regulating autophagy.Blocking autophagy with chloroquine exacerbated ER stress-induced apoptosis,indicating that normal levels of autophagy play a protective role in neuronal injury following cerebral ischemia/reperfusion injury.Findings from this study indicate that cerebral ischemia/reperfusion injury can trigger neuronal ER stress and promote autophagy,and suggest that PERK is a possible target for inhibiting excessive autophagy in cerebral ischemia/reperfusion injury.
基金supported by the National Natural Science Foundation of China (Grant Nos. 30871741 and 30972037)
文摘MicroRNAs (miRNAs) are a specialized class of small silencing RNAs that regulate gene expression in eukaryotes.In plants,miRNAs negatively regulate target mRNAs containing a highly complementary sequence by either mRNA cleavage or translational repression.As a model plant to study fleshy fruit ripening,miRNA studies in tomato have made great progress recently.MiRNAs were predicted to be involved in nearly all biological processes in tomato,particularly development,differentiation,and biotic and abiotic stress responses.Surprisingly,several miRNAs were verified to be involved in tomato fruit ripening and senescence.Recent studies suggest that miRNAs are related to host-virus interactions,which raises the possibility that miRNAs can be used as diagnostic markers for response to virus infection in tomato plants.In this review,we summarize our current knowledge systematically and advance future directions for miRNA research in tomato.
