Tight regulation of nuclear factor-kB(NF-kB)signaling is essential to maintain homeostasis in immune system in response to various stimuli,which hasbeen studied extensivelyand deeply.However,the molecularmechanisms re...Tight regulation of nuclear factor-kB(NF-kB)signaling is essential to maintain homeostasis in immune system in response to various stimuli,which hasbeen studied extensivelyand deeply.However,the molecularmechanisms responsible for its negative regulation are not completely understood.Here we demonstrate that human coilin-interacting nuclear ATPase protein(hCINAP)is a novel negative regulator in NF-kB signaling by deactivating IkB kinase(IKK)complex.In response to TNF stimulation,hCINAP dynamically associates with IKKa and IKKb and inhibits IKK phosphorylation.Notably,hCINAP directly interacts with the catalytic subunits of protein phosphatase 1(PP1)and mediates the formation of IKK–hCINAP–PP1 complex,serving as an adaptor protein that recruits PP1 to dephosphorylate IKK.Furthermore,decreased levels of hCINAP are observed in several inflammatory diseases with NF-kB hyperactivity.Our study suggests a novel mechanism underlying deactivation of IKK and provides new insight into the negative regulation of NF-kB signaling.展开更多
BACKGROUND Ulcerative colitis(UC)is a chronic,nonspecific intestinal inflammatory disease with undefined pathogenesis.Non-SMC condensin I complex subunit D2(NCAPD2)and non-SMC condensin II complex subunit D3(NCAPD3)pl...BACKGROUND Ulcerative colitis(UC)is a chronic,nonspecific intestinal inflammatory disease with undefined pathogenesis.Non-SMC condensin I complex subunit D2(NCAPD2)and non-SMC condensin II complex subunit D3(NCAPD3)play pivotal roles in chromosome assembly and segregation during both mitosis and meiosis.To date,there has been no relevant report about the functional role of NCAPD2 and NCAPD3 in UC.AIM To determine the level of NCAPD2/3 in intestinal mucosa and explore the mechanisms of NCAPD2/3 in UC.METHODS Levels of NCAPD2/3 in intestinal tissue were detected in 30 UC patients and 30 healthy individuals with in situ hybridization(ISH).In vitro,NCM60 cells were divided into the NC group,model group,si-NCAPD2 group,si-NCAPD3 group and si-NCAPD2+si-NCAPD3 group.Inflammatory cytokines were measured by ELISA,IKK and NF-κB were evaluated by western blot,and IKK nucleation and NF-κB volume were analyzed by immunofluorescence assay.RESULTS Compared with expression in healthy individuals,NCAPD2 and NCAPD3 expression in intestinal tissue was significantly upregulated(P<0.001)in UC patients.Compared with levels in the model group,IL-1β,IL-6 and TNF-αin the si-NCAPD2,si-NCAPD3 and si-NCAPD2+si-NCAPD3 groups were significantly downregulated(P<0.01).IKK and NF-κB protein expression in the si-NCAPD2,si-NCAPD3 and si-NCAPD2+si-NCAPD3 groups was significantly decreased(P<0.01).Moreover,IKK nucleation and NF-κB volume were suppressed upon si-NCAPD2,si-NCAPD3 and si-NCAPD2+si-NCAPD3 transfection.CONCLUSION NCAPD2/3 is highly expressed in the intestinal mucosa of patients with active UC.Overexpression of NCAPD2/3 promotes the release of pro-inflammatory cytokines by modulating the IKK/NF-κB signaling pathway.展开更多
基金supported by the National Science Foundation of China(31170709,31470754)the Seeding Grant for Medicine and Life Sciences of Peking University(2014-MB-02)the Doctoral Fund of Ministry of Education of China(20130001130003).
文摘Tight regulation of nuclear factor-kB(NF-kB)signaling is essential to maintain homeostasis in immune system in response to various stimuli,which hasbeen studied extensivelyand deeply.However,the molecularmechanisms responsible for its negative regulation are not completely understood.Here we demonstrate that human coilin-interacting nuclear ATPase protein(hCINAP)is a novel negative regulator in NF-kB signaling by deactivating IkB kinase(IKK)complex.In response to TNF stimulation,hCINAP dynamically associates with IKKa and IKKb and inhibits IKK phosphorylation.Notably,hCINAP directly interacts with the catalytic subunits of protein phosphatase 1(PP1)and mediates the formation of IKK–hCINAP–PP1 complex,serving as an adaptor protein that recruits PP1 to dephosphorylate IKK.Furthermore,decreased levels of hCINAP are observed in several inflammatory diseases with NF-kB hyperactivity.Our study suggests a novel mechanism underlying deactivation of IKK and provides new insight into the negative regulation of NF-kB signaling.
基金Supported by National Natural Science Foundation of China,No.81673973Natural Science Foundation of Jiangsu Province,China,No.BK20161577the Developing Program for Highlevel Academic Talent from Jiangsu Hospital of Chinese Medicine,No.y2018rc16
文摘BACKGROUND Ulcerative colitis(UC)is a chronic,nonspecific intestinal inflammatory disease with undefined pathogenesis.Non-SMC condensin I complex subunit D2(NCAPD2)and non-SMC condensin II complex subunit D3(NCAPD3)play pivotal roles in chromosome assembly and segregation during both mitosis and meiosis.To date,there has been no relevant report about the functional role of NCAPD2 and NCAPD3 in UC.AIM To determine the level of NCAPD2/3 in intestinal mucosa and explore the mechanisms of NCAPD2/3 in UC.METHODS Levels of NCAPD2/3 in intestinal tissue were detected in 30 UC patients and 30 healthy individuals with in situ hybridization(ISH).In vitro,NCM60 cells were divided into the NC group,model group,si-NCAPD2 group,si-NCAPD3 group and si-NCAPD2+si-NCAPD3 group.Inflammatory cytokines were measured by ELISA,IKK and NF-κB were evaluated by western blot,and IKK nucleation and NF-κB volume were analyzed by immunofluorescence assay.RESULTS Compared with expression in healthy individuals,NCAPD2 and NCAPD3 expression in intestinal tissue was significantly upregulated(P<0.001)in UC patients.Compared with levels in the model group,IL-1β,IL-6 and TNF-αin the si-NCAPD2,si-NCAPD3 and si-NCAPD2+si-NCAPD3 groups were significantly downregulated(P<0.01).IKK and NF-κB protein expression in the si-NCAPD2,si-NCAPD3 and si-NCAPD2+si-NCAPD3 groups was significantly decreased(P<0.01).Moreover,IKK nucleation and NF-κB volume were suppressed upon si-NCAPD2,si-NCAPD3 and si-NCAPD2+si-NCAPD3 transfection.CONCLUSION NCAPD2/3 is highly expressed in the intestinal mucosa of patients with active UC.Overexpression of NCAPD2/3 promotes the release of pro-inflammatory cytokines by modulating the IKK/NF-κB signaling pathway.
