Stomatin-knockdown effectively attenuates sepsis-induced oxidative stress and inflammation of alveolar epithelial cells by regulating CD36.

Sepsis-induced acute lung injury is a type of lung disease with a high fatality rate that is characterized by acute inflammation. In the present study, the underlying role and potential mechanism of the stomatin (STOM) protein were investigated in lipopolysaccharide (LPS)-induced oxidative stress and inflammation in a mouse lung epithelial cell line, MLE-12. The expression levels of STOM and CD36 were measured using reverse transcription-quantitative PCR and western blotting. Subsequently, the expression levels of STOM and CD36 in LPS-treated MLE-12 cells were knocked down or overexpressed, respectively, via transfection with a small interfering RNA-STOM or a CD36-overexpression vector. An RNA immunoprecipitation (RIP) assay was used to determine the interaction between STOM and CD36, while Cell Counting Kit-8 assay and ELISA were performed to detect cell viability and oxidative stress, respectively. Moreover, western blotting and ELISA kits were used to detect the expression levels of associated inflammatory factors. The results of the present study demonstrated that STOM expression was upregulated in MLE-12 cells treated with LPS compared with the untreated control group. According to the Search Tool for the Retrieval of Interacting Genes/Proteins database, it was predicted that STOM and CD36 had the ability to interact with each other. The predicted binding between STOM and CD36 was verified using a RIP assay. The results demonstrated that STOM positively regulated the expression of CD36. Moreover, in LPS-treated MLE-12 cells, STOM-knockdown reversed the inhibitory effects of LPS on cell viability, and the promoting effects of LPS on oxidative stress and inflammation. These aforementioned changes were alleviated by the overexpression of CD36. To conclude, the results of the present study revealed that STOM may interact with CD36 to affect the levels of oxidative stress and inflammation in LPS-treated MLE-12 cells.