Stattic administration plays a protective role in a lipopolysaccharide-induced acute lung injury cell model

Inflammation and apoptosis are vital the processesis of acute lung injury (ALI). Signal transducer and activator of transcription 3 (Stat3) plays diverse roles in cellular processes. Little is known about the activation and function of lungs during ALI. Stat3 activation is observed during ALI. RAW264.7 cells were treated with lipopolysaccharide (LPS) to establish an ALI cell model. Stattic, a Stat3 inhibitor, was then administered to LPS-treated RAW264.7, to probe its effect on inflammation, apoptosis, and oxidative stress in vitro. Western blot analysis confirmed that Stat3 was upregulated and phosphorylated in LPS-exposed cells, while stattic administration decreased these effects. LPS treatment reduced cell viability, as evidenced by MTT, CCK-8, and colony formation assays. However, cell viability was restored after treatment with stattic. ELISA and quantitative PCR indicated that pro-inflammation cytokines, such as Interleukin-1β, IL-6, IL-8, matrix metalloproteinase-13, and tumor necrosis factor-α, were robustly elevated due to LPS stimulation; however, stattic treatment abolished the upregulation of these cytokines. Furthermore, analysis of oxidative stress effectors (malondialdehyde, glutathione, catalase, and superoxide dismutase) showed that LPS treatment upregulated oxidative stress, which was confirmed by the deactivation of the Kelch-like ECH-associated protein 1/nuclear factor erythroid 2-related factor 2/heme oxygenase-1/NAD(P)H quinone dehydrogenase 1 pathway. Apoptosis in cells was also upregulated by LPS. Stattic alleviated oxidative stress and apoptosis induced by LPS. Moreover, Stat3 overexpression reversed the protective effects of stattic on cell viability, inflammation, oxidative stress, and apoptosis. Our study demonstrates that stattic treatment mitigates LPS-triggered inflammatory injury by deactivating the Jak1/Stat3 pathway in ALI.