Silencing of circ-PRKCH protects against lipopolysaccharide (LPS)-evoked chondrocyte damage and extracellular matrix loss by the miR-140-3p/ADAM10 axis

Circular RNAs (circRNAs) have been implicated in the pathology of osteoarthritis (OA). Nevertheless, the precise actions of circRNA protein kinase C eta (circ-PRKCH, hsa_circ_0032131) on OA pathogenesis are still undiscovered. Cell viability and apoptosis were determined using Cell Counting-8 Kit (CCK-8) assay and flow cytometry, respectively. The levels of circ-PRKCH, microRNA (miR)-140- 3p and a-disintegrin and metallopeptidase domain 10 (ADAM10) mRNA were tested by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot. Targeted interplays among circ- PRKCH, miR-140-3p and ADAM10 were verified by dual-luciferase reporter assay. circ-PRKCH was up-regulated in OA tissues and lipopolysaccharide (LPS)-evoked C-28/I2 cells. circ-PRKCH knockdown alleviated LPS-evoked cell injury and extracellular matrix (ECM) loss in C-28/I2 cells. Mechanistically, circ-PRKCH acted as a miR-140-3p sponge. Moreover, the silencing of circ-PRKCH exerted a protective role in LPS-evoked C-28/I2 cells by up-regulating miR-140-3p. ADAM10 was a direct target of miR- 140-3p, and miR-140-3p overexpression mitigated LPS-evoked C-28/I2 cell injury and ECM loss by down-regulating ADAM10. Furthermore, circ-PRKCH mediated ADAM10 expression via sponging miR-140-3p in C-28/I2 cells. Our present study suggested that circ-PRKCH silencing alleviated LPSevoked chondrocyte injury and ECM loss partially through the miR-140-3p/ADAM10 axis.