Cell communication and signaling : CCS · 2025
RNA polymerase II subunit 5-mediating protein limits TLR4-induced innate immune activation in macrophages by inhibiting IKKβ/NF-κB signaling during sepsis.
СтатьяНазвание и аннотация: Перевод в очереди
Обработка статьи · этапы, ошибки и управление
Загрузка состояния…
Ошибки и ограничения
История · было → стало
Состояние обновляется каждые 5 секунд, пока блок открыт. Процент показывается только там, где известен объём работы. Пауза останавливает продолжение этапа; текущий запрос к источнику может завершиться.
Pang Shu-Jie, Jiang Tian-Yi, Wang Nai-Guo, Cui Xiao-Wen, Wang Hui, Pan Yu-Fei, Yang Ning, Dong Li-Wei
Аннотация
BACKGROUND: Nuclear factor κB (NF-κB) activity is a central component of inflammatory and innate immune responses, which plays a crucial role in sepsis. The inhibition of NF-κB signaling and the IκB kinase (IKK) complex is important for understanding the control of innate immunity and regulating the progress of sepsis.
METHODS: We constructed transgenic mouse strains (Rmpf/f; Lyz2-Cre+), and then established lipopolysaccharide (LPS), cecal ligation and perforation (CLP)-induced sepsis models. Hematoxylin-eosin (HE) staining, ELISA, and flow cytometry assay were employed to evaluate the sepsis-related damage and the activation of the inflammatory-related signaling pathway. In vitro, differential expression of RMP cell lines and primary macrophage isolated from transgenic mice were utilized to assess the activation of the NF-κB signaling pathway by Western blot (WB), reverse transcription-polymerase chain reaction (RT-PCR), and ELISA tests. Co‑immunoprecipitation (Co-IP), WB, GST-pulldown, phosphorylation mass spectrometry, surface plasmon resonance (SPR), and IKK activity detection assay were employed to investigate the underlying molecular mechanism by which RMP restrains IKK-NF-κB pathway.
RESULTS: We identified RNA polymerase II subunit 5 (RPB5)-mediating protein (RMP) as an inhibitor of the IKK complex, which thus inhibited NF-κB signaling in macrophages. In resting macrophages, RMP was directly bound to the kinase domain of IKKβ and inhibited its activity by recruiting protein phosphatase 2 A (PP2A) to the IKK complex. When mouse macrophages were treated with LPS, a Toll-like receptor 4 (TLR4) agonist that stimulates NF-κB signaling, RMP was phosphorylated by IKKβ at Ser439 and dissociated from the IKK complex, which further activated NF-κB signaling. Macrophage-specific deletion of Rmp reduced survival in mice due to an increased inflammatory response in experimental models of sepsis.
CONCLUSIONS: RMP inhibits TLR4-induced NF-κB activation and exerts homeostatic control of innate immunity, and may be promising as a therapeutic target in the limiting of NF-κB signaling and attenuating sepsis-related damage.
METHODS: We constructed transgenic mouse strains (Rmpf/f; Lyz2-Cre+), and then established lipopolysaccharide (LPS), cecal ligation and perforation (CLP)-induced sepsis models. Hematoxylin-eosin (HE) staining, ELISA, and flow cytometry assay were employed to evaluate the sepsis-related damage and the activation of the inflammatory-related signaling pathway. In vitro, differential expression of RMP cell lines and primary macrophage isolated from transgenic mice were utilized to assess the activation of the NF-κB signaling pathway by Western blot (WB), reverse transcription-polymerase chain reaction (RT-PCR), and ELISA tests. Co‑immunoprecipitation (Co-IP), WB, GST-pulldown, phosphorylation mass spectrometry, surface plasmon resonance (SPR), and IKK activity detection assay were employed to investigate the underlying molecular mechanism by which RMP restrains IKK-NF-κB pathway.
RESULTS: We identified RNA polymerase II subunit 5 (RPB5)-mediating protein (RMP) as an inhibitor of the IKK complex, which thus inhibited NF-κB signaling in macrophages. In resting macrophages, RMP was directly bound to the kinase domain of IKKβ and inhibited its activity by recruiting protein phosphatase 2 A (PP2A) to the IKK complex. When mouse macrophages were treated with LPS, a Toll-like receptor 4 (TLR4) agonist that stimulates NF-κB signaling, RMP was phosphorylated by IKKβ at Ser439 and dissociated from the IKK complex, which further activated NF-κB signaling. Macrophage-specific deletion of Rmp reduced survival in mice due to an increased inflammatory response in experimental models of sepsis.
CONCLUSIONS: RMP inhibits TLR4-induced NF-κB activation and exerts homeostatic control of innate immunity, and may be promising as a therapeutic target in the limiting of NF-κB signaling and attenuating sepsis-related damage.