The innate immune sensor NLRP3 inflammasome overactivation is involved in the pathogenesis of ulcerative colitis.PGAM5 is a mitochondrial phosphatase involved in NLRP3 inflammasome activation in macrophages.However,th...The innate immune sensor NLRP3 inflammasome overactivation is involved in the pathogenesis of ulcerative colitis.PGAM5 is a mitochondrial phosphatase involved in NLRP3 inflammasome activation in macrophages.However,the role of PGAM5 in ulcerative colitis and the mechanisms underlying PGAM5 regulating NLRP3 activity remain unknown.Here,we show that PGAM5 deficiency ameliorates dextran sodium sulfate(DSS)-induced colitis in mice via suppressing NLRP3 inflammasome activation.By combining APEX2-based proximity labeling focused on PGAM5 with quantitative proteomics,we identify NEK7 as the new binding partner of PGAM5 to promote NLRP3 inflammasome assembly and activation in a PGAM5 phosphatase activity-independent manner upon inflammasome induction.Interfering with PGAM5eNEK7 interaction by punicalagin inhibits the activation of the NLRP3 inflammasome in macrophages and ameliorates DSS-induced colitis in mice.Altogether,our data demonstrate the PGAM5eNEK7 interaction in macrophages for NLRP3 inflammasome activation and further provide a promising therapeutic strategy for ulcerative colitis by blocking the PGAM5eNEK7 interaction.展开更多
Nucleotide binding domain,leucine-rich repeat,and pyrin domain-containing 3(NLRP3)is an NLR-protein family member that can be activated by diverse exogenous and endogenous stimuli but without direct binding of any of ...Nucleotide binding domain,leucine-rich repeat,and pyrin domain-containing 3(NLRP3)is an NLR-protein family member that can be activated by diverse exogenous and endogenous stimuli but without direct binding of any of these pathogen ligands.Biological studies show that inactive NLRP3 is usually in an as-sembly state and its activation requires a kinase protein,NEK7.However,our re-cent computational studies as well as other biological investigations have demonstrated that NEK7 does not play a significant role in the activation of NLRP3 assembly and activation.In-stead,biological studies suggest that NEK7 is essential in the dissociation of inactive NLRP3 assemblies.Despite extensive research,the dissociation mechanism of the inactive NLRP3 as-sembly remains largely elusive.In this work,an improved MM-PBSA method is applied to the protein-protein binding free energies in the inactive NLRP3 decamer.Combined with the po-tential mean force(PMF)computation for the 0°→5°conformational change,the standard free-energy change,ΔG^(0)is calculated for NEK7-driven association of the inactive NLRP3 de-camer.Our calculations show that in the absence of NEK7,the dissociation of the inactive NLRP3 decamer is an energetically unfavorable process(ΔG^(0)=99.69 kcal/mol),whereas upon NEK7 binding,the overall standard free energy differenceΔG^(0)=-24.21 kcal/mol is obtained for the inactive NLRP3 decamer dissociation.The free-energy difference calcula-tions in this work also disclose an energetically optimized dissociation pathway,along which the inactive NLRP3 decamer is disunited by a one-by-one dissociation mechanism.展开更多
10,11-Dehydrocurvularin(DCV)is a natural-product macrolide that has been shown to exert anti-inflammatory activity.However,the underlying mechanism of its anti-inflammatory activity remains poorly understood.Aberrant ...10,11-Dehydrocurvularin(DCV)is a natural-product macrolide that has been shown to exert anti-inflammatory activity.However,the underlying mechanism of its anti-inflammatory activity remains poorly understood.Aberrant activation of the NLRP3 inflammasome is involved in diverse inflammation-related diseases,which should be controlled.The results showed that DCV specifically inhibited the activation of the NLRP3 inflammasome in association with reduced IL-1βsecretion and caspase-1 activation,without effect on the NLRC4 and AIM2 inflammasomes.Furthermore,DCV disturbed the interaction between NEK7 and NLRP3,resulting in the inhibition of NLRP3 inflammasome activation.The C=C double bond of DCV was required for the NLRP3 inflammasome inhibition induced by DCV.Importantly,DCV ameliorated inflammation in vivo through inhibiting the NLRP3 inflammasome.Taken together,our study reveals a novel mechanism by which DCV suppresses inflammation,which indicates the potential role of DCV in NLRP3 inflammasome-driven inflammatory disorders.展开更多
基金supported by the National Natural Science Foundation of China(82174010 and 81973512)the Open Fund of the State Key Laboratory of Pharmaceutical Biotechnology,Nanjing University(Grant No.KF-202206,China)the Double First-Class Project of China Pharmaceutical University(CPUQNJC22_02,China)。
文摘The innate immune sensor NLRP3 inflammasome overactivation is involved in the pathogenesis of ulcerative colitis.PGAM5 is a mitochondrial phosphatase involved in NLRP3 inflammasome activation in macrophages.However,the role of PGAM5 in ulcerative colitis and the mechanisms underlying PGAM5 regulating NLRP3 activity remain unknown.Here,we show that PGAM5 deficiency ameliorates dextran sodium sulfate(DSS)-induced colitis in mice via suppressing NLRP3 inflammasome activation.By combining APEX2-based proximity labeling focused on PGAM5 with quantitative proteomics,we identify NEK7 as the new binding partner of PGAM5 to promote NLRP3 inflammasome assembly and activation in a PGAM5 phosphatase activity-independent manner upon inflammasome induction.Interfering with PGAM5eNEK7 interaction by punicalagin inhibits the activation of the NLRP3 inflammasome in macrophages and ameliorates DSS-induced colitis in mice.Altogether,our data demonstrate the PGAM5eNEK7 interaction in macrophages for NLRP3 inflammasome activation and further provide a promising therapeutic strategy for ulcerative colitis by blocking the PGAM5eNEK7 interaction.
基金supported by Ministry of Science and Technology of China(2022YFA1303100)the National Natural Science Foundation of China(No.32090040)。
文摘Nucleotide binding domain,leucine-rich repeat,and pyrin domain-containing 3(NLRP3)is an NLR-protein family member that can be activated by diverse exogenous and endogenous stimuli but without direct binding of any of these pathogen ligands.Biological studies show that inactive NLRP3 is usually in an as-sembly state and its activation requires a kinase protein,NEK7.However,our re-cent computational studies as well as other biological investigations have demonstrated that NEK7 does not play a significant role in the activation of NLRP3 assembly and activation.In-stead,biological studies suggest that NEK7 is essential in the dissociation of inactive NLRP3 assemblies.Despite extensive research,the dissociation mechanism of the inactive NLRP3 as-sembly remains largely elusive.In this work,an improved MM-PBSA method is applied to the protein-protein binding free energies in the inactive NLRP3 decamer.Combined with the po-tential mean force(PMF)computation for the 0°→5°conformational change,the standard free-energy change,ΔG^(0)is calculated for NEK7-driven association of the inactive NLRP3 de-camer.Our calculations show that in the absence of NEK7,the dissociation of the inactive NLRP3 decamer is an energetically unfavorable process(ΔG^(0)=99.69 kcal/mol),whereas upon NEK7 binding,the overall standard free energy differenceΔG^(0)=-24.21 kcal/mol is obtained for the inactive NLRP3 decamer dissociation.The free-energy difference calcula-tions in this work also disclose an energetically optimized dissociation pathway,along which the inactive NLRP3 decamer is disunited by a one-by-one dissociation mechanism.
基金the National Natural Science Foundation of China(No.81902852)China Postdoctoral Science Foundation(No.2020M670220)+2 种基金the Natural Science Foundation of Hubei Province of China(No.2022CFB481)the Natural Science Foundation of Hubei Provincial Department of Education(No.T2022021)Wudang Local Chinese Medicine Research of Hubei University of Medicine(No.WDCM2020004).
文摘10,11-Dehydrocurvularin(DCV)is a natural-product macrolide that has been shown to exert anti-inflammatory activity.However,the underlying mechanism of its anti-inflammatory activity remains poorly understood.Aberrant activation of the NLRP3 inflammasome is involved in diverse inflammation-related diseases,which should be controlled.The results showed that DCV specifically inhibited the activation of the NLRP3 inflammasome in association with reduced IL-1βsecretion and caspase-1 activation,without effect on the NLRC4 and AIM2 inflammasomes.Furthermore,DCV disturbed the interaction between NEK7 and NLRP3,resulting in the inhibition of NLRP3 inflammasome activation.The C=C double bond of DCV was required for the NLRP3 inflammasome inhibition induced by DCV.Importantly,DCV ameliorated inflammation in vivo through inhibiting the NLRP3 inflammasome.Taken together,our study reveals a novel mechanism by which DCV suppresses inflammation,which indicates the potential role of DCV in NLRP3 inflammasome-driven inflammatory disorders.
