Background:During Enterovirus type 71(EV71)infection,the structural viral protein 1(VP1)activates endoplasmic reticulum(ER)stress associated with peripheral myelin protein 22(PMP22)accumulation and induces autophagy.H...Background:During Enterovirus type 71(EV71)infection,the structural viral protein 1(VP1)activates endoplasmic reticulum(ER)stress associated with peripheral myelin protein 22(PMP22)accumulation and induces autophagy.However,the specific mechanism behind this process remains elusive.Methods:In this research,we used the VP1-overexpressing mouse Schwann cells(SCs)models co-transfected with a PMP22 silencing or Autocrine motility factor receptor(AMFR/gp78)overexpressing vector to explore the regulation of gp78 on PMP22 and its relationship with autophagy and apoptosis.Results:The activity of gp78 could be influenced by EV71-VP1,leading to a decrease in the ubiquitination and degradation of PMP22,resulting in PMP22 accumulation in ER.In VP1-overexpressing mouse SCs,all three ER stress sensors,including pancreatic endoplasmic reticulum kinase(PERK),activating transcription factor 6(ATF6)and inositol-requiring enzyme 1(IRE1)and the related downstream signals(C/EBP-homologous protein(CHOP)and Caspase 12)were activated,as well as the ER-resident chaperone Glucose-regulated protein 78(GRP78).In addition,VP1 upregulated the autophagy marker Microtubule-associated protein 1 light chain 3 beta(LC3B),while PMP22 silencing or gp78 overexpression reversed the phenomenon.Meanwhile,PMP22 silencing or gp78 overexpression increased proliferation of EV71-VP1-transfected mouse SCs.Conclusion:Gp78 could regulate PMP22 accumulation through ubiquitination degradation and cause ER stress and autophagy in EV71-VP1-overexpressing mouse SCs.Therefore,the gp78/PMP22/ER stress axis might emerge as a promising therapeutic target for myelin and neuronal damage induced by EV71 infection.展开更多
An improved carbohydrate derivatization method employing 1-phenyl-3-methyl-5-pyrazolone(PMP) was developed in this study.Liquid ammonia was used instead of sodium hydroxide aqueous solution to provide the base medium ...An improved carbohydrate derivatization method employing 1-phenyl-3-methyl-5-pyrazolone(PMP) was developed in this study.Liquid ammonia was used instead of sodium hydroxide aqueous solution to provide the base medium for the derivatization reaction.Derivatization reaction and HPLC separation conditions were optimized,including reaction time,reaction temperature and PMP consumption.The derivatives of five reducing monosaccharides were well separated by HPLC. Because we employed ammonia instead of sodium hydro-xide,the excessive volatile ammonia can be removed by vacumm drying,these derivatives could be directly analyzed by MALDI-TOF-MS without desalting procedure,possessing potential application for monosaccharide and oligosaccharide separation and subsequent MS analysis.This method not only increased the MS detection sensitivity,but also decreased sample wastes during purification. We successfully applied this method to mo-nosaccharide composition analysis of polysaccharides SPPA-1,SPPB-1 and SPPC-1 purified from Spirulina(Platensis).展开更多
基金The study was supported by Guangdong Natural Science Foundation(Grant Numbers 2020A1515010014,2022A1515012411)Science and Technology Key Project for People’s Livelihood of Guangzhou,China(Grant Number 202206010060)+1 种基金Guangzhou Science and Technology Bureau Basic Research Project(SL2024A03J01288)Innovative Project of Children’s Research Institute,Guangzhou Women and Children’s Medical Center,China(Grant Numbers Pre-NSFC-2019-002,NKE PRE-2019-015).
文摘Background:During Enterovirus type 71(EV71)infection,the structural viral protein 1(VP1)activates endoplasmic reticulum(ER)stress associated with peripheral myelin protein 22(PMP22)accumulation and induces autophagy.However,the specific mechanism behind this process remains elusive.Methods:In this research,we used the VP1-overexpressing mouse Schwann cells(SCs)models co-transfected with a PMP22 silencing or Autocrine motility factor receptor(AMFR/gp78)overexpressing vector to explore the regulation of gp78 on PMP22 and its relationship with autophagy and apoptosis.Results:The activity of gp78 could be influenced by EV71-VP1,leading to a decrease in the ubiquitination and degradation of PMP22,resulting in PMP22 accumulation in ER.In VP1-overexpressing mouse SCs,all three ER stress sensors,including pancreatic endoplasmic reticulum kinase(PERK),activating transcription factor 6(ATF6)and inositol-requiring enzyme 1(IRE1)and the related downstream signals(C/EBP-homologous protein(CHOP)and Caspase 12)were activated,as well as the ER-resident chaperone Glucose-regulated protein 78(GRP78).In addition,VP1 upregulated the autophagy marker Microtubule-associated protein 1 light chain 3 beta(LC3B),while PMP22 silencing or gp78 overexpression reversed the phenomenon.Meanwhile,PMP22 silencing or gp78 overexpression increased proliferation of EV71-VP1-transfected mouse SCs.Conclusion:Gp78 could regulate PMP22 accumulation through ubiquitination degradation and cause ER stress and autophagy in EV71-VP1-overexpressing mouse SCs.Therefore,the gp78/PMP22/ER stress axis might emerge as a promising therapeutic target for myelin and neuronal damage induced by EV71 infection.
文摘An improved carbohydrate derivatization method employing 1-phenyl-3-methyl-5-pyrazolone(PMP) was developed in this study.Liquid ammonia was used instead of sodium hydroxide aqueous solution to provide the base medium for the derivatization reaction.Derivatization reaction and HPLC separation conditions were optimized,including reaction time,reaction temperature and PMP consumption.The derivatives of five reducing monosaccharides were well separated by HPLC. Because we employed ammonia instead of sodium hydro-xide,the excessive volatile ammonia can be removed by vacumm drying,these derivatives could be directly analyzed by MALDI-TOF-MS without desalting procedure,possessing potential application for monosaccharide and oligosaccharide separation and subsequent MS analysis.This method not only increased the MS detection sensitivity,but also decreased sample wastes during purification. We successfully applied this method to mo-nosaccharide composition analysis of polysaccharides SPPA-1,SPPB-1 and SPPC-1 purified from Spirulina(Platensis).
