Pentatricopeptide repeat(PPR)proteins perform essential functions in post-transcriptional regulation of gene expression,particularly RNA editing and RNA splicing,in plant organelles.Although research on chloroplast bi...Pentatricopeptide repeat(PPR)proteins perform essential functions in post-transcriptional regulation of gene expression,particularly RNA editing and RNA splicing,in plant organelles.Although research on chloroplast biogenesis and development has been extensive,the functions of most PPR genes in this process in rice(Oryza sativa)remain incompletely understood.This study identifies a novel P-type PPR protein,YELLOW-GREEN LEAF AND SEEDLING LETHALITY(YGS),which localizes to rice chloroplasts.YGS shows predominant expression in leaves.The ygs mutants,generated through CRISPR/Cas9-mediated genome editing of the YGS gene,displayed yellow-green leaves and seedling lethality.These phenotypes corresponded with reduced pigment levels and disrupted chloroplast ultrastructure compared to wild-type plants.Furthermore,the expression of genes associated with chloroplast development and chlorophyll biosynthesis showed significant alterations in the ygs mutants.The absence of YGS function affected RNA editing of rpl2 and intron splicing of ycf3-1 in the plastid genome.Additionally,YGS demonstrated interaction with the chloroplast signal recognition particle protein Oscp SRP54b in yeast two-hybrid and bimolecular fluorescence complementation analyses.These results indicate that YGS participates in RNA editing and RNA splicing in chloroplasts,thus serving a vital role in rice chloroplast development.展开更多
In our previous study, we have elucidated the chemical profile ofYGS40, a fraction of Yi-Gan San （YGS）, used for the treatment of Alzheimer＇s disease （AD）. Oxidative stress-induced apoptosis is implicated in neur...In our previous study, we have elucidated the chemical profile ofYGS40, a fraction of Yi-Gan San （YGS）, used for the treatment of Alzheimer＇s disease （AD）. Oxidative stress-induced apoptosis is implicated in neurodegenerative disorders such as AD. The aim of the present study was to explore the protective effects of YGS40 against hydrogen peroxide （H202）-induced apoptosis in PC12 cells and the underlying mechanisms. PC12 cells were exposed to 100 μmol·L 1 of H202 for 12 h with or without YGS40 pretreatment. Cytotoxicity was determined by MTT （3, （4, 5-dimethylthiazole-2-yl） 2, 5-diphenyl-tetrazolium bromide） and lactate dehydrogenase （LDH） release assays; apoptosis was detected by Annexin V/propidium iodide coupled staining and by determining caspase-3 activity and Bax and Bcl-2 protein levels. Mitochondrial membrane potential （MMP） was assessed by the retention of rhodamine123; and the activities of superoxide dismutase （SOD） and malondialdehyde （MDA） were measured using commercially available enzymatic kits. Pretreatment with YGS40 significantly prevented H2O2-induced cytotoxicity and protected the cells against H2O2-triggered apoptosis characterized by extemalization of membrane phosphatidylserine and caspase-3 activation and the increased ratio of Bax/Bcl-2 in PC12 cells. Further studies showed that YGS40 suppressed H2O2-induced MMP loss, increased SOD activity, and decreased MDA level. These findings suggest that YGS40 may be beneficial for the prevention and treatment of oxidative stress-mediated disorders.展开更多
基金supported by the National Natural Science Foundation of China(32201784,32072048,and U2004204)the Natural Science Foundation of Shandong Province,China(ZR2020QC111 and ZR2022QC176)the Talent Introduction Project of Dezhou University,China(2020xjrc207)。
文摘Pentatricopeptide repeat(PPR)proteins perform essential functions in post-transcriptional regulation of gene expression,particularly RNA editing and RNA splicing,in plant organelles.Although research on chloroplast biogenesis and development has been extensive,the functions of most PPR genes in this process in rice(Oryza sativa)remain incompletely understood.This study identifies a novel P-type PPR protein,YELLOW-GREEN LEAF AND SEEDLING LETHALITY(YGS),which localizes to rice chloroplasts.YGS shows predominant expression in leaves.The ygs mutants,generated through CRISPR/Cas9-mediated genome editing of the YGS gene,displayed yellow-green leaves and seedling lethality.These phenotypes corresponded with reduced pigment levels and disrupted chloroplast ultrastructure compared to wild-type plants.Furthermore,the expression of genes associated with chloroplast development and chlorophyll biosynthesis showed significant alterations in the ygs mutants.The absence of YGS function affected RNA editing of rpl2 and intron splicing of ycf3-1 in the plastid genome.Additionally,YGS demonstrated interaction with the chloroplast signal recognition particle protein Oscp SRP54b in yeast two-hybrid and bimolecular fluorescence complementation analyses.These results indicate that YGS participates in RNA editing and RNA splicing in chloroplasts,thus serving a vital role in rice chloroplast development.
基金supported by the National Natural Science Foundation of China(Nos.81274046 and 81373956)
文摘In our previous study, we have elucidated the chemical profile ofYGS40, a fraction of Yi-Gan San （YGS）, used for the treatment of Alzheimer＇s disease （AD）. Oxidative stress-induced apoptosis is implicated in neurodegenerative disorders such as AD. The aim of the present study was to explore the protective effects of YGS40 against hydrogen peroxide （H202）-induced apoptosis in PC12 cells and the underlying mechanisms. PC12 cells were exposed to 100 μmol·L 1 of H202 for 12 h with or without YGS40 pretreatment. Cytotoxicity was determined by MTT （3, （4, 5-dimethylthiazole-2-yl） 2, 5-diphenyl-tetrazolium bromide） and lactate dehydrogenase （LDH） release assays; apoptosis was detected by Annexin V/propidium iodide coupled staining and by determining caspase-3 activity and Bax and Bcl-2 protein levels. Mitochondrial membrane potential （MMP） was assessed by the retention of rhodamine123; and the activities of superoxide dismutase （SOD） and malondialdehyde （MDA） were measured using commercially available enzymatic kits. Pretreatment with YGS40 significantly prevented H2O2-induced cytotoxicity and protected the cells against H2O2-triggered apoptosis characterized by extemalization of membrane phosphatidylserine and caspase-3 activation and the increased ratio of Bax/Bcl-2 in PC12 cells. Further studies showed that YGS40 suppressed H2O2-induced MMP loss, increased SOD activity, and decreased MDA level. These findings suggest that YGS40 may be beneficial for the prevention and treatment of oxidative stress-mediated disorders.
