MiR-877-5p down-regulation of PDK-1 involving in aspirin-induced gastric epithelial cells damage

Abstract It has been found that the expression of miR-877-5p is increased in serum of patients taking NSAIDs drugs. However, whether miR-877-5p play a role in aspirin-induced gastrointestinal mucosal erosion remains largely unknown. In this study, we investigated the effects of miR-877-5p on gastric epithelial cells (GES-1) proliferation and apoptosis in vitro. MiR-877-5p mimic/inhibitor and their oligonucleotides were transfected into GES-1 cells, then GES-1 cells were treated with different concentrations of aspirin (1.25, 2.5, 5 and 10 mmol/L). The bioinformatics software and dual-luciferase reporter assay were used to predict and verify the target gene of miR-877-5p. qRT-PCR and Western Blotting were employed to assess gene and protein expression, and CCK-8 assay and flow cytometry analysis were used to detect cell proliferation and apoptosis, respectively. qRT-PCR data showed that miR-877-5p level was significantly increased in aspirin incubated GES-1 cells. The proliferation of GES-1 cells were markedly inhibited and apoptosis was significantly induced in the miR-877-5p mimic groups compared to control groups. Using PITA, Targetscan and miRWalk database, the three databases indicated that PDK1 was a target gene of miR-miR-877-5p. Dual luciferase reporter assay confirmed that the existence of a direct interaction between miR-877-5p and PDK1 mRNA. Importantly, miR-877-5p knockdown resulted in a significant upregulation of PDK1 mRNA and its encoded protein in GES-1 cells. miR-877-5p plays a role in aspirin-induced gastrointestinal mucosal erosion, which may via down-regulation of targeting PDK1 gene.