CIAP1/2 can regulate the inflammatory response and lung injury induced by apoptosis in septic rats

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), induced by sepsis, is predominantly caused by inflammation injury. However, there is no clear consensus on how to regulate the inflammatory response. The TNF pathway is one of the primary inflammatory pathways activated in sepsis. cIAP1/2, an essential E3 ubiquitin ligase in the TNF pathway, plays a pivotal role in positively regulating the activation of nuclear factor κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways to promote inflammation while inhibiting apoptosis. We found that Birc2 is the only differential expression gene in TNF pathway, and both cIAP1/2 upregulated in lung lysate with worsen lung injury. However, upon inhibiting cIAP1/2 using AZD5582, lung cell apoptosis was reactivated, and a significant improvement in lung injury was observed. Our study shows that cIAP1/2 expression increased in the lung tissue of a CLP rat ALI model. Inhibiting cIAP1/2 with AZD5582, a second mitochondria-derived activator of caspases (SMAC) mimetic, induced increased apoptosis and reduced lung injury. Therefore, inhibiting cIAP1/2 can alleviate sepsis-induced ALI, providing a new target for regulating organ damage induced by sepsis-induced inflammatory responses.