Hypothermia protects against ventilator-induced lung injury by limiting IL-1β release and NETs formation

Although mechanical ventilation is a critical intervention for acute respiratory distress syndrome (ARDS), it can trigger an IL-1{beta}-associated complication known as ventilator-induced lung injury. In mice, we found that LPS and high-volume ventilation, LPS-HVV, leads to hypoxemia with neutrophil extracellular traps (NETs) formation in the alveoli. Furthermore, Il1r1-/- LPS-HVV mice did not develop hypoxemia and had reduced NETs, indicating that IL-1R1 signaling is important for NETs formation and hypoxemia. Therapeutic hypothermia (TH) is known to reduce the release of inflammatory mediators. In LPS-HVV mice, TH (32 {degrees}C body temperature) prevented hypoxemia development, reducing albumin leakage, IL-1{beta}, gasdermin D (GSDMD) and NETs formation. We also observed that LPS-primed macrophages, when stimulated at 32{degrees}C with ATP or nigericin, release less IL-1{beta} associated with reduced GSDMD cleavage. Thus, hypothermia is an important modulating factor in the NLRP3 inflammasome activation, IL-1{beta} release and NETs formation, preventing LPS-HVV-induced acute respiratory failure.