Mitochondrial derived reactive oxygen species activates NLRP3 inflammasome in cardiac fibroblasts in sepsis

Abstract

BackgroundSepsis is a common disease in intensive care unit in hospital. It is caused by exaggerated host response to infection. Septic myocardial dysfunction plays an important role in pathogenesis of multiple organ failure and subsequent high mortality of patients with sepsis. Our previous studies indicate that activation of NLRP3 inflammasome in cardiac fibroblasts (CF) contributes to sepsis‐induced myocardial dysfunction. The aim of the present study is to identify the role of mitochondrial ROS (mtROS) in the activation of the NLRP3 inflammasome in CF.MethodsCultured CF was primed with LPS (1 ng/mL) followed by ATP (3 mmol/L) treatment for activation of NLRP3 inflammasome. CF mtROS was detected with MitoSOX reagent, a probe specifically detects mitochondrial ROS. NLRP3 inflammasome activation was assessed with Western blot, ELISA and co‐immunoprecipitation.ResultsATP challenge of CF primed with LPS increased CF mtROS production which was attenuated by pretreatment of the LPS primed CF with mito‐TEMPO (25 mmol/L), an ROS scavenger targeted at mtROS. ATP challenge of the LPS primed CF activated the NLRP3 inflammasome as indicated by increase in intracellular levels of NLRP3, pro‐IL‐1β and released IL‐1β. Mito‐TEMPO pretreatment of the CF with LPS+ATP prevented the increase of released IL‐1β in CF. Finally, ATP challenge of the LPS primed CF promoted NLRP3 interaction with the ASC. The Mito‐TEMPO pretreatment of the CF diminished the interaction between the NLRP3 and ASC.ConclusionOur data suggest that mitochondrial derived ROS plays a pivotal role in the activation of the CF NLRP3 inflammasome in sepsis.Support or Funding InformationThe study was supported by Natural Science Foundation of Jiangsu Province (BK20151332) and Natural Science Foundation of China (81370333).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.