AIM:To explore the effect of silent information regulator factor 2-related enzyme 1(SIRT1)on modulating apoptosis of human lens epithelial cells(HLECs)and alleviating lens opacification of rats through suppressing end...AIM:To explore the effect of silent information regulator factor 2-related enzyme 1(SIRT1)on modulating apoptosis of human lens epithelial cells(HLECs)and alleviating lens opacification of rats through suppressing endoplasmic reticulum(ER)stress.METHODS:HLECs(SRA01/04)were treated with varying concentrations of tunicamycin(TM)for 24h,and the expression of SIRT1 and C/EBP homologous protein(CHOP)was assessed using real-time quantitative polymerase chain reaction(RT-PCR),Western blotting,and immunofluorescence.Cell morphology and proliferation was evaluated using an inverted microscope and cell counting kit-8(CCK-8)assay,respectively.In the SRA01/04 cell apoptosis model,which underwent siRNA transfection for SIRT1 knockdown and SRT1720 treatment for its activation,the expression levels of SIRT1,CHOP,glucose regulated protein 78(GRP78),and activating transcription factor 4(ATF4)were examined.The potential reversal of SIRT1 knockdown effects by 4-phenyl butyric acid(4-PBA;an ER stress inhibitor)was investigated.In vivo,age-related cataract(ARC)rat models were induced by sodium selenite injection,and the protective role of SIRT1,activated by SRT1720 intraperitoneal injections,was evaluated through morphology observation,hematoxylin and eosin(H&E)staining,Western blotting,and RT-PCR.RESULTS:SIRT1 expression was downregulated in TMinduced SRA01/04 cells.Besides,in SRA01/04 cells,both cell apoptosis and CHOP expression increased with the rising doses of TM.ER stress was stimulated by TM,as evidenced by the increased GRP78 and ATF4 in the SRA01/04 cell apoptosis model.Inhibition of SIRT1 by siRNA knockdown increased ER stress activation,whereas SRT1720 treatment had opposite results.4-PBA partly reverse the adverse effect of SIRT1 knockdown on apoptosis.In vivo,SRT1720 attenuated the lens opacification and weakened the ER stress activation in ARC rat models.CONCLUSION:SIRT1 plays a protective role against TM-induced apoptosis in HLECs and slows the progression of cataract in rats by inhibiting ER stress.These findings suggest a novel strategy for cataract treatment focused on targeting ER stress,highlighting the therapeutic potential of SIRT1 modulation in ARC development.展开更多
Metal ions are essential for plant growth and development,but in excess,these compounds can become highly toxic.Plants have adopted numerous ways to maintain metal homeostasis while mitigating adverse effects of exces...Metal ions are essential for plant growth and development,but in excess,these compounds can become highly toxic.Plants have adopted numerous ways to maintain metal homeostasis while mitigating adverse effects of excess metal ions,including phytochelatin and the metal-chelating proteins metallothioneins(MTs).A family of cysteine(Cys)-rich,intracellular,and low-molecular-weight(4-8 kDa)MTs are proteins found in nearly all phyla including plants,animals,and fungi,and they have the potential to scavenge reactive oxygen species and detoxify toxic metals including copper,cadmium,and zinc.Based on their Cys numbers and residues,MTs have been categorized into three major classes.Class I MTs,which have highly conserved Cys residues,are found in animals,while class II MTs,with less conserved Cys residues,are present in plants and are classified further into four groups.Class III MTs include phytochelatins,a group of enzymatically synthesized Cys-rich proteins.The MTs have been an area of interest for five decades with extensive studies,which have been facilitated by advancements in instrumental techniques,protein science,and molecular biology tools.Here,we reviewed current advances in our understanding of the regulation of MT biosynthesis,their expression,and their potential roles in the alleviation of abiotic stresses(i.e.,drought,salinity,and oxidative stresses)and heavy metal detoxification and homeostasis.展开更多
Copper is a trace element that is required by almost all forms of life.Acting as cofactors for various key metabolism enzymes,copper takes part in many vital biological processes.Previous studies have found the concen...Copper is a trace element that is required by almost all forms of life.Acting as cofactors for various key metabolism enzymes,copper takes part in many vital biological processes.Previous studies have found the concentration of copper is significantly higher in tumor cells than in normal cells.In addition,copper can promote angiogenesis by activating VEGF and FGF signaling.展开更多
Amino acids have various prominent functions in plants. Besides their usage during protein biosynthesis, they also represent building blocks for several other biosynthesis pathways and play pivotal roles during signal...Amino acids have various prominent functions in plants. Besides their usage during protein biosynthesis, they also represent building blocks for several other biosynthesis pathways and play pivotal roles during signaling processes as well as in plant stress response. In general, pool sizes of the 20 amino acids differ strongly and change dynamically depending on the developmental and physiological state of the plant cell. Besides amino acid biosynthesis, which has already been investigated in great detail, the catabolism of amino acids is of central importance for adjusting their pool sizes but so far has drawn much less attention. The degradation of amino acids can also contribute substantially to the energy state of plant cells under certain physiological conditions, e.g. carbon starvation. In this review, we discuss the biological role of amino acid catabolism and summarize current knowledge on amino acid degradation pathways and their regulation in the context of plant cell physiology.展开更多
基金Supported by National Natural Science Foundation for Young Scientists of China(No.82101097)National Natural Science Foundation of China(No.82070937).
文摘AIM:To explore the effect of silent information regulator factor 2-related enzyme 1(SIRT1)on modulating apoptosis of human lens epithelial cells(HLECs)and alleviating lens opacification of rats through suppressing endoplasmic reticulum(ER)stress.METHODS:HLECs(SRA01/04)were treated with varying concentrations of tunicamycin(TM)for 24h,and the expression of SIRT1 and C/EBP homologous protein(CHOP)was assessed using real-time quantitative polymerase chain reaction(RT-PCR),Western blotting,and immunofluorescence.Cell morphology and proliferation was evaluated using an inverted microscope and cell counting kit-8(CCK-8)assay,respectively.In the SRA01/04 cell apoptosis model,which underwent siRNA transfection for SIRT1 knockdown and SRT1720 treatment for its activation,the expression levels of SIRT1,CHOP,glucose regulated protein 78(GRP78),and activating transcription factor 4(ATF4)were examined.The potential reversal of SIRT1 knockdown effects by 4-phenyl butyric acid(4-PBA;an ER stress inhibitor)was investigated.In vivo,age-related cataract(ARC)rat models were induced by sodium selenite injection,and the protective role of SIRT1,activated by SRT1720 intraperitoneal injections,was evaluated through morphology observation,hematoxylin and eosin(H&E)staining,Western blotting,and RT-PCR.RESULTS:SIRT1 expression was downregulated in TMinduced SRA01/04 cells.Besides,in SRA01/04 cells,both cell apoptosis and CHOP expression increased with the rising doses of TM.ER stress was stimulated by TM,as evidenced by the increased GRP78 and ATF4 in the SRA01/04 cell apoptosis model.Inhibition of SIRT1 by siRNA knockdown increased ER stress activation,whereas SRT1720 treatment had opposite results.4-PBA partly reverse the adverse effect of SIRT1 knockdown on apoptosis.In vivo,SRT1720 attenuated the lens opacification and weakened the ER stress activation in ARC rat models.CONCLUSION:SIRT1 plays a protective role against TM-induced apoptosis in HLECs and slows the progression of cataract in rats by inhibiting ER stress.These findings suggest a novel strategy for cataract treatment focused on targeting ER stress,highlighting the therapeutic potential of SIRT1 modulation in ARC development.
基金This research was supported by the National Key R&D Programe of China(No.2018 YFA 0900600).
文摘Metal ions are essential for plant growth and development,but in excess,these compounds can become highly toxic.Plants have adopted numerous ways to maintain metal homeostasis while mitigating adverse effects of excess metal ions,including phytochelatin and the metal-chelating proteins metallothioneins(MTs).A family of cysteine(Cys)-rich,intracellular,and low-molecular-weight(4-8 kDa)MTs are proteins found in nearly all phyla including plants,animals,and fungi,and they have the potential to scavenge reactive oxygen species and detoxify toxic metals including copper,cadmium,and zinc.Based on their Cys numbers and residues,MTs have been categorized into three major classes.Class I MTs,which have highly conserved Cys residues,are found in animals,while class II MTs,with less conserved Cys residues,are present in plants and are classified further into four groups.Class III MTs include phytochelatins,a group of enzymatically synthesized Cys-rich proteins.The MTs have been an area of interest for five decades with extensive studies,which have been facilitated by advancements in instrumental techniques,protein science,and molecular biology tools.Here,we reviewed current advances in our understanding of the regulation of MT biosynthesis,their expression,and their potential roles in the alleviation of abiotic stresses(i.e.,drought,salinity,and oxidative stresses)and heavy metal detoxification and homeostasis.
文摘Copper is a trace element that is required by almost all forms of life.Acting as cofactors for various key metabolism enzymes,copper takes part in many vital biological processes.Previous studies have found the concentration of copper is significantly higher in tumor cells than in normal cells.In addition,copper can promote angiogenesis by activating VEGF and FGF signaling.
文摘Amino acids have various prominent functions in plants. Besides their usage during protein biosynthesis, they also represent building blocks for several other biosynthesis pathways and play pivotal roles during signaling processes as well as in plant stress response. In general, pool sizes of the 20 amino acids differ strongly and change dynamically depending on the developmental and physiological state of the plant cell. Besides amino acid biosynthesis, which has already been investigated in great detail, the catabolism of amino acids is of central importance for adjusting their pool sizes but so far has drawn much less attention. The degradation of amino acids can also contribute substantially to the energy state of plant cells under certain physiological conditions, e.g. carbon starvation. In this review, we discuss the biological role of amino acid catabolism and summarize current knowledge on amino acid degradation pathways and their regulation in the context of plant cell physiology.
