TY - JOUR
T1 - Extracellular RNA Sensing Mediates Inflammation and Organ Injury in a Murine Model of Polytrauma
AU - Suen, Andrew O.
AU - Chen, Fengqian
AU - Wang, Sheng
AU - Li, Ziyi
AU - Zhu, Jing
AU - Yang, Yang
AU - Conn, Olivia
AU - Lopez, Kerri
AU - Cui, Ping
AU - Wechsler, Laurence
AU - Cross, Alan
AU - Fiskum, Gary
AU - Kozar, Rosemary
AU - Hu, Peter
AU - Miller, Catriona
AU - Zou, Lin
AU - Williams, Brittney
AU - Chao, Wei
N1 - Publisher Copyright:
© 2023 American Association of Immunologists. All rights reserved.
PY - 2023/6
Y1 - 2023/6
N2 - Severe traumatic injury leads to marked systemic inflammation and multiorgan injury. Endogenous drivers such as extracellular nucleic acid may play a role in mediating innate immune response and the downstream pathogenesis. Here, we explored the role of plasma extracellular RNA (exRNA) and its sensing mechanism in inflammation and organ injury in a murine model of polytrauma. We found that severe polytrauma—bone fracture, muscle crush injury, and bowel ischemia—induced a marked increase in plasma exRNA, systemic inflammation, and multiorgan injury in mice. Plasma RNA profiling with RNA sequencing in mice and humans revealed a dominant presence of miRNAs and marked differential expression of numerous miRNAs after severe trauma. Plasma exRNA isolated from trauma mice induced a dose-dependent cytokine production in macrophages, which was almost abolished in TLR7-deficient cells but unchanged in TLR3-deficient cells. Moreover, RNase or specific miRNA inhibitors against the selected proinflammatory miRNAs (i.e., miR-7a-5p, miR-142, let-7j, miR-802, and miR-146a-5p) abolished or attenuated trauma plasma exRNA-induced cytokine production, respectively. Bioinformatic analyses of a group of miRNAs based on cytokine readouts revealed that high uridine abundance (>40%) is a reliable predictor in miRNA mimic-induced cytokine and complement production. Finally, compared with the wild-type, TLR7-knockout mice had attenuated plasma cytokine storm and reduced lung and hepatic injury after polytrauma. These data suggest that endogenous plasma exRNA of severely injured mice and ex-miRNAs with high uridine abundance prove to be highly proinflammatory. TLR7 sensing of plasma exRNA and ex-miRNAs activates innate immune responses and plays a role in inflammation and organ injury after trauma.
AB - Severe traumatic injury leads to marked systemic inflammation and multiorgan injury. Endogenous drivers such as extracellular nucleic acid may play a role in mediating innate immune response and the downstream pathogenesis. Here, we explored the role of plasma extracellular RNA (exRNA) and its sensing mechanism in inflammation and organ injury in a murine model of polytrauma. We found that severe polytrauma—bone fracture, muscle crush injury, and bowel ischemia—induced a marked increase in plasma exRNA, systemic inflammation, and multiorgan injury in mice. Plasma RNA profiling with RNA sequencing in mice and humans revealed a dominant presence of miRNAs and marked differential expression of numerous miRNAs after severe trauma. Plasma exRNA isolated from trauma mice induced a dose-dependent cytokine production in macrophages, which was almost abolished in TLR7-deficient cells but unchanged in TLR3-deficient cells. Moreover, RNase or specific miRNA inhibitors against the selected proinflammatory miRNAs (i.e., miR-7a-5p, miR-142, let-7j, miR-802, and miR-146a-5p) abolished or attenuated trauma plasma exRNA-induced cytokine production, respectively. Bioinformatic analyses of a group of miRNAs based on cytokine readouts revealed that high uridine abundance (>40%) is a reliable predictor in miRNA mimic-induced cytokine and complement production. Finally, compared with the wild-type, TLR7-knockout mice had attenuated plasma cytokine storm and reduced lung and hepatic injury after polytrauma. These data suggest that endogenous plasma exRNA of severely injured mice and ex-miRNAs with high uridine abundance prove to be highly proinflammatory. TLR7 sensing of plasma exRNA and ex-miRNAs activates innate immune responses and plays a role in inflammation and organ injury after trauma.
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U2 - 10.4049/jimmunol.2300103
DO - 10.4049/jimmunol.2300103
M3 - Article
C2 - 37133342
AN - SCOPUS:85163226931
SN - 2573-7732
VL - 210
SP - 1990
EP - 2000
JO - ImmunoHorizons
JF - ImmunoHorizons
IS - 12
ER -