Repeated mild closed head injury(rmCHI)is a significant public health concern,and this type of repetitive injury is garnering increasing attention,not least because of its increasing incidence in sports.The underlying...Repeated mild closed head injury(rmCHI)is a significant public health concern,and this type of repetitive injury is garnering increasing attention,not least because of its increasing incidence in sports.The underlying neuroimmune mechanisms secondary to trauma that link rmCHI to cognitive impairment remain to be elucidated,and the contribution of the complement system to the pathological sequelae of this type of brain injury is unexplored.Here,using C57BL/6J mice,we established a repetitive 12-head impact model to investigate the neuroimmune and pathological processes that occur after rmCHI.We specifically studied the role of complement in pathology and cognitive impairment up to 21 days after the cessation of injury in a clinically relevant paradigm using the site-targeted complement inhibitor CR2-Crry.Our analytical methods included mass cytometry,RNA-seq,proteomics,and immunohistological characterization.Mass cytometric analysis revealed that cognitive impairment after rmCHI was associated with major subacute/chronic alterations in local immune cell recruitment,particularly the recruitment and activation of microglia,with marked upregulation of complement receptors and proteins associated with the phagocytic machinery.RNA-seq and proteomic analysis revealed major changes in pathways associated with neurodegeneration,neuronal apoptosis,and the upregulation of complement proteins in animals subjected to rmCHI.Complement inhibition initiated after cessation of injury modulated rmCHIinduced changes and protected against cognitive impairment.In addition to expanding our understanding of the pathological sequelae of rmCHI,these data highlight the therapeutic potential of complement inhibition.展开更多
基金supported by grants from the United States Department of Veterans Affairs(IK6BX005235,BX004256,BX005853,RX03958)to STthe National Institutes of Health and American Cancer Society(R01 CA258882 and RSG-24-1255025-01)to SG+8 种基金the Department of Defense(HT94252510707)to CKthe National Center for Advancing translational Sciences of the NIH(TL1 TR001451&UL1 TR001450)to DHthe Brain Injury Association of America’s(BIAA)(A22-0232-001)CDA Award Number BX006450 from the United States(U.S.)Department of Veterans Affairs Biomedical Laboratory R&D Service awarded to KMsupported by the Research Centers in Minority Institutions(RCMI)Grant Number U54MD007602 from the National Institute of Minority Health and Health Disparities(NIMHD)awarded to the Morehouse School of MedicineThe authors acknowledge the MUSC Mass Spectrometry Facility and the NIH shared instrumentation grant for the Orbitrap Lumos MS(NIH S10 OD025126)The authors also acknowledge the MUSC Cell and Molecular Imaging Core,supported by the Shared Instrumentation Grants S10 OD018113 and S10 OD028663The study was supported by the Flow Cytometry and Cell Sorting Shared Resources(P30 CA138313)the CNDD Mouse Behavior Phenotyping Core(P20 GM148302)。
文摘Repeated mild closed head injury(rmCHI)is a significant public health concern,and this type of repetitive injury is garnering increasing attention,not least because of its increasing incidence in sports.The underlying neuroimmune mechanisms secondary to trauma that link rmCHI to cognitive impairment remain to be elucidated,and the contribution of the complement system to the pathological sequelae of this type of brain injury is unexplored.Here,using C57BL/6J mice,we established a repetitive 12-head impact model to investigate the neuroimmune and pathological processes that occur after rmCHI.We specifically studied the role of complement in pathology and cognitive impairment up to 21 days after the cessation of injury in a clinically relevant paradigm using the site-targeted complement inhibitor CR2-Crry.Our analytical methods included mass cytometry,RNA-seq,proteomics,and immunohistological characterization.Mass cytometric analysis revealed that cognitive impairment after rmCHI was associated with major subacute/chronic alterations in local immune cell recruitment,particularly the recruitment and activation of microglia,with marked upregulation of complement receptors and proteins associated with the phagocytic machinery.RNA-seq and proteomic analysis revealed major changes in pathways associated with neurodegeneration,neuronal apoptosis,and the upregulation of complement proteins in animals subjected to rmCHI.Complement inhibition initiated after cessation of injury modulated rmCHIinduced changes and protected against cognitive impairment.In addition to expanding our understanding of the pathological sequelae of rmCHI,these data highlight the therapeutic potential of complement inhibition.
