Purpose: This study aimed to explore the effects of a 10-week combined exercise regimen on immobilizationinduced muscle atrophy and elucidate the possible function of Protein arginine methyltransferase 1(Prmt1) in thi...Purpose: This study aimed to explore the effects of a 10-week combined exercise regimen on immobilizationinduced muscle atrophy and elucidate the possible function of Protein arginine methyltransferase 1(Prmt1) in this process.Methods: 8-week-old male C57BL/6J mice were carried out combined exercise for 10 weeks. One week before the end of the intervention, mice underwent cast immobilization. Additionally, to investigate the potential mechanism in exercise-induced protection of skeletal muscle, mice in the exercise preconditioning group were administered TC-E-5003(an inhibitor of Prmt1 enzymatic activity). Exercise performance, muscle mass, and the cross-sectional area(CSA) of muscle fibers were analyzed. Besides, Prmt1 and Sestrin1(Sesn1) were either overexpressed or inhibited in C2C12 myotubes to elucidate the underlying mechanism.Results: Exercise preconditioning not only significantly improved muscle mass and motor ability in immobilized mice but also inhibited excessive activation of degradation pathways and enhanced protein synthesis. Importantly, Prmt1 mediated the protective effects of exercise preconditioning on muscle atrophy. Mechanistically,Prmt1 regulated the p38 mitogen-activated protein kinase(p38)/activating transcription factor 2(ATF2)pathway, which modulates Sesn1 expression. Sesn1 acts as a downstream of Prmt1 and ATF2, contributing to the myoblast differentiation and skeletal muscle regeneration through AMP-Activated protein kinase α2(AMPKα2)/transcriptional co-activator PPAR-γ co-activator-1 α(PGC-1α) signaling pathway.Conclusions: Taken together, our results highlighted the effectiveness of exercise preconditioning in preventing muscle atrophy via the Prmt1-Sesn1 pathway.展开更多
Microglial pyroptosis and neuroinflammation have been implicated in the pathogenesis of sepsis-associated encephalopathy(SAE).OGT-mediated O-GlcNAcylation is involved in neurodevelopment and injury.However,its regulat...Microglial pyroptosis and neuroinflammation have been implicated in the pathogenesis of sepsis-associated encephalopathy(SAE).OGT-mediated O-GlcNAcylation is involved in neurodevelopment and injury.However,its regulatory function in microglial pyroptosis and involvement in SAE remains unclear.In this study,we demonstrated that OGT deficiency augmented microglial pyroptosis and exacerbated secondary neuronal injury.Furthermore,OGT inhibition impaired cognitive function in healthy mice and accelerated the progression in SAE mice.Mechanistically,OGT-mediated O-GlcNAcylation of ATF2 at Ser44 inhibited its phosphorylation and nuclear translocation,thereby amplifying NLRP3 inflammasome activation and promoting inflammatory cytokine production in microglia in response to LPS/Nigericin stimulation.In conclusion,this study uncovers the critical role of OGT-mediated O-GlcNAcylation in modulating microglial activity through the regulation of ATF2 and thus protects against SAE progression.展开更多
Pseudorabies virus(PRV),an etiological agent of pseudorabies in livestock,has negatively affected the porcine industry all over the world.Epithelial cells are reported as the first site of PRV infection.However,the ro...Pseudorabies virus(PRV),an etiological agent of pseudorabies in livestock,has negatively affected the porcine industry all over the world.Epithelial cells are reported as the first site of PRV infection.However,the role of host proteins and its related signaling pathways in PRV replication is largely unclear.In this study,we performed a quantitative phosphoproteomics screening on PRV-infected porcine kidney(PK-15)epithelial cells.Totally 5723phosphopeptides,corresponding to 2180 proteins,were obtained,and the phosphorylated states of 810 proteins were significantly different in PRV-infected cells compared with mock-infected cells(P<0.05).GO and KEGG analysis revealed that these differentially expressed phosphorylated proteins were predominantly related to RNA transport and MAPK signaling pathways.Further functional studies of NF-κB,transcription activator factor-2(ATF2),MAX and SOS genes in MAPK signaling pathway were analyzed using RNA interference(RNAi)knockdown.It showed that only ATF2-knockdown reduces both PRV titer and viral genome copy number.JNK pathway inhibition and CRISPR/Cas9 gene knockout showed that ATF2 was required for the effective replication of PRV,especially during the biogenesis of viral genome DNA.Subsequently,by overexpression of the ATF2 gene and point mutation of the amino acid positions 69/71 of ATF2,it was further demonstrated that the phosphorylation of ATF2 promoted PRV replication.These findings suggest that ATF2 may provide potential therapeutic target for inhibiting PRV infection.展开更多
基金funded by research grants from the National Natural Science Foundation of China (32171135 and 32371168)。
文摘Purpose: This study aimed to explore the effects of a 10-week combined exercise regimen on immobilizationinduced muscle atrophy and elucidate the possible function of Protein arginine methyltransferase 1(Prmt1) in this process.Methods: 8-week-old male C57BL/6J mice were carried out combined exercise for 10 weeks. One week before the end of the intervention, mice underwent cast immobilization. Additionally, to investigate the potential mechanism in exercise-induced protection of skeletal muscle, mice in the exercise preconditioning group were administered TC-E-5003(an inhibitor of Prmt1 enzymatic activity). Exercise performance, muscle mass, and the cross-sectional area(CSA) of muscle fibers were analyzed. Besides, Prmt1 and Sestrin1(Sesn1) were either overexpressed or inhibited in C2C12 myotubes to elucidate the underlying mechanism.Results: Exercise preconditioning not only significantly improved muscle mass and motor ability in immobilized mice but also inhibited excessive activation of degradation pathways and enhanced protein synthesis. Importantly, Prmt1 mediated the protective effects of exercise preconditioning on muscle atrophy. Mechanistically,Prmt1 regulated the p38 mitogen-activated protein kinase(p38)/activating transcription factor 2(ATF2)pathway, which modulates Sesn1 expression. Sesn1 acts as a downstream of Prmt1 and ATF2, contributing to the myoblast differentiation and skeletal muscle regeneration through AMP-Activated protein kinase α2(AMPKα2)/transcriptional co-activator PPAR-γ co-activator-1 α(PGC-1α) signaling pathway.Conclusions: Taken together, our results highlighted the effectiveness of exercise preconditioning in preventing muscle atrophy via the Prmt1-Sesn1 pathway.
基金supported by the Jiangsu Provincial Medical Key Discipline(Laboratory)Cultivation Unit(JSDW202249)the Natural Science Foundation of Jiangsu Province(BK20211108)+4 种基金a Scientific Research Project of the Health Commission of Nantong(MS2023035)Nantong Natural Science Foundation(JC2023114)the Scientific Research Innovation Team of Kangda College of Nanjing Medical University(KD2022KYCXTD005)Nantong University Clinical Medicine Special Project(2022JY005)the Postgraduate Research&Practice Innovation Program of Jiangsu province(KYCX23_3416).
文摘Microglial pyroptosis and neuroinflammation have been implicated in the pathogenesis of sepsis-associated encephalopathy(SAE).OGT-mediated O-GlcNAcylation is involved in neurodevelopment and injury.However,its regulatory function in microglial pyroptosis and involvement in SAE remains unclear.In this study,we demonstrated that OGT deficiency augmented microglial pyroptosis and exacerbated secondary neuronal injury.Furthermore,OGT inhibition impaired cognitive function in healthy mice and accelerated the progression in SAE mice.Mechanistically,OGT-mediated O-GlcNAcylation of ATF2 at Ser44 inhibited its phosphorylation and nuclear translocation,thereby amplifying NLRP3 inflammasome activation and promoting inflammatory cytokine production in microglia in response to LPS/Nigericin stimulation.In conclusion,this study uncovers the critical role of OGT-mediated O-GlcNAcylation in modulating microglial activity through the regulation of ATF2 and thus protects against SAE progression.
基金the Natural Science Foundation of China(32170155,31770191)the Major Science and Technology Projects of Hubei Province(2021ABA005)to Z.F.L。
文摘Pseudorabies virus(PRV),an etiological agent of pseudorabies in livestock,has negatively affected the porcine industry all over the world.Epithelial cells are reported as the first site of PRV infection.However,the role of host proteins and its related signaling pathways in PRV replication is largely unclear.In this study,we performed a quantitative phosphoproteomics screening on PRV-infected porcine kidney(PK-15)epithelial cells.Totally 5723phosphopeptides,corresponding to 2180 proteins,were obtained,and the phosphorylated states of 810 proteins were significantly different in PRV-infected cells compared with mock-infected cells(P<0.05).GO and KEGG analysis revealed that these differentially expressed phosphorylated proteins were predominantly related to RNA transport and MAPK signaling pathways.Further functional studies of NF-κB,transcription activator factor-2(ATF2),MAX and SOS genes in MAPK signaling pathway were analyzed using RNA interference(RNAi)knockdown.It showed that only ATF2-knockdown reduces both PRV titer and viral genome copy number.JNK pathway inhibition and CRISPR/Cas9 gene knockout showed that ATF2 was required for the effective replication of PRV,especially during the biogenesis of viral genome DNA.Subsequently,by overexpression of the ATF2 gene and point mutation of the amino acid positions 69/71 of ATF2,it was further demonstrated that the phosphorylation of ATF2 promoted PRV replication.These findings suggest that ATF2 may provide potential therapeutic target for inhibiting PRV infection.
