SOCS-1 Suppresses Inflammation Through Inhibition of NALP3 Inflammasome Formation in Smoke Inhalation-Induced Acute Lung Injury

Smoke inhalation leads to acute lung injury (ALI), a devastating clinical problem associated with high mortality rates. Suppressor of cytokine signaling-1 (SOCS-1) is a negative regulator of proinflammatory cytokine signaling. We have found that adenoviral gene transfer of SOCS-1 ameliorates smoke inhalation-induced lung injury in C57BL/6 mice. We also found that the release of adenosine triphosphate (ATP) was increased post smoke exposure, while oxidized ATP, an inhibitor of purinergic P2X7 receptor, suppressed smoke-induced NALP3 inflammasome assembly, caspase-1 activation, and K⁺ efflux. Similar to oxidized ATP, high protein level of SOCS-1 dampened the formation of NALP3 inflammasome and the activation of caspase-1 and IL-1β induced by smoke exposure in mouse alveolar macrophages. In conclusion, SOCS-1 relieves smoke inhalation-induced pulmonary inflammation and injury by inhibiting NALP3 inflammasome formation.