Neutrophil-derived PAD4 induces citrullination of CKMT1 exacerbates mucosal inflammation in inflammatory bowel disease  

作　　者：Shuling Wang Yihang Song Zhijie Wang Xin Chang Haicong Wu Ziwei Yan Jiayi Wu Zixuan He Le Kang Wenjun Hu Tian Xia Zhaoshen Li Xingxing Ren Yu Bai 

机构地区：[1]National Clinical Research Center for Digestive Diseases,Department of Gastroenterology,Changhai Hospital,Naval Medical University,Shanghai,200433,China [2]National Key Laboratory of Immunology and Inflammation,Naval Medical University,Shanghai,200433,China [3]Changhai Clinical Research Unit,Changhai Hospital,Naval Medical University,Shanghai,200433,China [4]Department of Gastroenterology,Changhai Hospital,Naval Medical University,Shanghai,200433,China [5]Institute of Immunology and the CAS Key Laboratory of Innate Immunity and Chronic Disease,Division of Life Sciences and Medicine,University of Science and Technology of China,Hefei,230027,China

出　　处：《Cellular & Molecular Immunology》2024年第6期620-633,共14页中国免疫学杂志（英文版）

基　　金：National Natural Science Foundation of China(No.82100587,No.82170567);National Key R&D Program of China(No.2023YFC2413801,China);Shanghai Sailing Program(No.21YF1458700);China National Postdoctoral Program for Innovative Talents(No.BX20220288);China Postdoctoral Science Foundation(No.2022M720138);Program of Shanghai Academic Research Leader(No.22XD1425000);Deep Blue Project of Naval Medical University(Pilot Talent Plan);Basic Medical Research Project of the First Affiliated Hospital of Naval Medical University(No.2023PY06);“Changying”Talent Program of Changhai Hospital of Naval Medical University,and the“Changjian”Talent Program of Changhai Hospital of Naval Medical University.

摘　　要：Peptidyl arginine deiminase 4(PAD4)plays a pivotal role in infection and inflammatory diseases by facilitating the formation of neutrophil extracellular traps(NETs).However,the substrates of PAD4 and its exact role in inflammatory bowel disease(IBD)remain unclear.In this study,we employed single-cell RNA sequencing(scRNA-seq)and substrate citrullination mapping to decipher the role of PAD4 in intestinal inflammation associated with IBD.Our results demonstrated that PAD4 deficiency alleviated colonic inflammation and restored intestinal barrier function in a dextran sulfate sodium(DSS)-induced colitis mouse model.scRNA-seq analysis revealed significant alterations in intestinal cell populations,with reduced neutrophil numbers and changes in epithelial subsets upon PAD4 deletion.Gene expression analysis highlighted pathways related to inflammation and epithelial cell function.Furthermore,we found that neutrophil-derived extracellular vesicles(EVs)carrying PAD4 were secreted into intestinal epithelial cells(IECs).Within IECs,PAD4 citrullinates mitochondrial creatine kinase 1(CKMT1)at the R242 site,leading to reduced CKMT1 protein stability via the autophagy pathway.This action compromises mitochondrial homeostasis,impairs intestinal barrier integrity,and induces IECs apoptosis.IEC-specific depletion of CKMT1 exacerbated intestinal inflammation and apoptosis in mice with colitis.Clinical analysis of IBD patients revealed elevated levels of PAD4,increased CKMT1 citrullination,and decreased CKMT1 expression.In summary,our findings highlight the crucial role of PAD4 in IBD,where it modulates IECs plasticity via CKMT1 citrullination,suggesting that PAD4 may be a potential therapeutic target for IBD.

关 键 词：Peptidyl-arginine deiminase-4 CITRULLINATION Mitochondrial creatine kinase 1 Intestinal epithelial cells Inflammatory bowel disease 

分 类 号：R574[医药卫生—消化系统]