Circ_0057452 functions as a ceRNA in hypertrophic scar fibroblast proliferation and VEGF expression by regulating TGF-β2 expression and adsorbing miR-145-5p

circ_0057452 can competitively bind miR-145-5p to induce the expression of TGF-β2, and then promote the proliferation of HS fibroblasts and secretion of VEGF, which is expected to be effective in the treatment of HS.

The expression of circ_0057452, miR-145-5p and TGF-β2 in HS tissues and fibroblasts was measured by quantitative real-time Polymerase Chain Reaction (qRT-PCR). The targeting relations between circ_0057452 and miR-145-5p, miR-145-5p and TGF-β2 were identified using dual-luciferase reporter assay. The expression of circ_0057452, miR-145-5p and TGF-β2 in fibroblasts was interfered with and cells were grouped. In each group, changes in cell proliferation were detected using CCK8 assay, apoptosis was measured by flow cytometry, and VEGF secreted in cell culture supernatant was tested by ELISA kit.

To explore the mechanism by which circ_0057452/miR-145-5p/TGF-β2 axis regulates fibroblast proliferation as well as VEGF expression in hypertrophic scars (HS).

Compared with normal tissues and fibroblasts, the expressions of circ_0057452 and TGF-β2 were increased and miR-145-5p decreased in HS tissues and cells (all P<0.05). Compared with the si-NC group, cell proliferation and VEGF expressions were decreased and the apoptotic rate increased in the si_circ_0057452 group (all P<0.05). Compared with the oe-NC group, cell proliferation and VEGF expression were increased and the apoptotic rate decreased in the oe-circ_0057452 group (all P<0.05). Compared with the oe-circ_0057452 + miR-NC group, the number of apoptotic cells was increased, and cell proliferation, as well as VEGF expression were decreased in the oe-circ_0057452 + miR-145-5p mimic group (all P<0.05). Compared with the miR-NC group, cell proliferation and VEGF expression were reduced and the apoptotic rate was increased in the miR-145-5p mimic group (all P<0.05). Compared with the miR-145-5p mimic + vector group, cell proliferation and VEGF expression were elevated, and apoptosis was inhibited in the miR-145-5p mimic + TGF-β2 group (all P<0.05).