Circ_0035292 knockdown alleviates lipopolysaccharide (LPS)-induced WI-38 cell apoptosis and inflammatory injury.

Background: Circular RNAs have emerged as important regulators in the pathogenesis of human diseases, including infantile pneumonia (IP). In this study, we aimed to explore the effects of circ_0035292 on lipopolysaccharide (LPS)-treated Wistsar Institute (WI)-38 cells.

Methods: Quantitative real-time polymerase chain reaction and western blot were executed to detect the levels of circ_0035292, microRNA-370-3p (miR-370-3p) and transducin β-like 1X related protein 1 (TBL1XR1). Cell counting kit-8, 5-ethynyl-2'-deoxyuridine, and flow cytometry assessed cell proliferation and apoptosis. Concentrations of inflammatory factors were examined with enzyme linked immunosorbent assay kits. Dual-luciferase reporter assay and RNA immunoprecipitation were adopted to analyze binding between miR-370-3p and circ_0035292 or TBL1XR1.

Results: Circ_0035292 level was increased in IP patients and LPS-triggered WI-38 cells. Circ_0035292 knockdown rescued LPS-mediated WI-38 cell proliferation suppression and WI-38 cell apoptosis and inflammation promotion. Circ_0035292 interacted with miR-370-3p and miR-370-3p directly targeted TBL1XR1. Moreover, miR-370-3p overexpression alleviated LPS-induced WI-38 cell apoptosis and inflammatory injury, which was abrogated via TBL1XR1 upregulation. Circ_0035292 absence inhibited the NF-κB pathway.

Conclusion: Knockdown of circ_0035292 rescued LPS-triggered WI-38 cell injury via miR-370-3p/TBL1XR1 axis and NF-κB pathway.