Effect and Mechanism of circSAMD4A Targeting miR-141-3p on Alveolar Epithelial Cell Injury

This study is aimed to investigate the effect of circSAMD4A on the injury of alveolar epithelial cells induced by SP (Streptococcus pneumoniae) and analyze its molecular mechanism. Alveolar epithelial cells were divided into control group, infection group, infection+si-circSAMD4A group, infection+si-NC group, infection+miR-141-3p group, infection+miR-NC group, infection+si-circSAMD4A+anti-miR-NC group, and infection+si-circSAMD4A+anti-miR-141-3p group. qRT-PCR was used to detect the expression of circSAMD4A and miR-141-3p. ELISA (enzyme-linked immunosorbent assay) was used to detect the levels of IL-6 and IL-10. Flow cytometry was used to detect the cell apoptosis rate. Western blot was used to detect protein expression of Cleaved-caspase3 and Cleaved-caspase9. Dual luciferase reporter experiment was used to detect the targeting relationship between circSAMD4A and miR-141-3p. The expression level of circSAMD4A in the alveolar epithelial cells induced by SP was increased; the expression level of miR-141-3p was decreased, the level of IL-10 and cell viability were decreased; the level of IL-6 was increased; the cell apoptosis rate and the expression levels of Cleaved caspase3 and Cleaved-caspase9 were increased (P<0.05). After interference with circSAMD4A or over-expression of miR-141-3p, IL-10 level and cell viability were increased; IL-6 level was decreased; cell apoptosis rate and Cleaved-caspase3 and Cleaved-caspase9 expression levels were decreased (P<0.05). circSAMD4A targeted miR141-3p. Down-regulating the expression of miR-141-3p leaded to reduced effects of interfering with circSAMD4A on SP-induced alveolar epithelial cell apoptosis, cell viability and inflammatory factor expression. Interference with circSAMD4A can inhibit the damage of alveolar epithelial cells induced by SP by targeting and up-regulating miR141-3p.

CSTR: 32200.14.cjcb.2023.01.0007