Circular RNA profiling reveals an abundant circPTK2 that contributes everolimus-induced endothelial cell dysfunction via regulating miR-1-5p/ACVR2B/StarD13 axis.

Background: mTOR inhibitors released from drug-eluting stents (DESs) play a critical role in the pathogenesis of in-stent neoatherosclerosis (ISNA), contributing to the development of late in-stent restenosis (ISR). Circular RNAs (circRNAs) are emerging as key regulators in various pathophysiological processes, but their involvement in ISNA remains unclear.

Methods: The expression pattern of circRNAs in human umbilical vein endothelial cells (HUVECs) treated with everolimus (EVL) was analysed using RNA sequencing. The expression levels of circRNAs, miR-1-5p, and the downstream targets ACVR2B/StarD13 were measured by quantitative real-time PCR. The effects of circPTK2 on cell proliferation, migration, apoptosis, and permeability in EVL-treated endothelial cells were assessed using cell counting kit-8, scratch, Annexin-V FITC and PI double-staining, and transwell assays. Bioinformatics analysis and dual luciferase assay were used to identify the interaction between circPTK2 and miR-1-5p. The association between circPTK2, miR-1-5p, and ACVR2B/StarD13 was further evaluated by functional rescue experiments.

Results: CircPTK2 was significantly upregulated in EVL-treated HUVECs. Knockdown of circPTK2 reversed the EVL-induced suppression of cell viability and migration, reduced apoptosis, and alleviated endothelial barrier leakage. Conversely, circPTK2 overexpression produced the opposite effects. Mechanistically, circPTK2 acted as a sponge for miR-1-5p, leading to increased expression of its target genes ACVR2B and StarD13. Silencing ACVR2B or StarD13 partially attenuated the exacerbating effects of miR-1-5p inhibition on EVL-induced endothelial dysfunction. Moreover, inflammatory conditions affected the expressions of circPTK2, miR-1-5p, and ACVR2B/StarD13.

Conclusions: CircPTK2 regulates EVL-induced endothelial dysfunction via the miR-1-5p/ACVR2B/StarD13 axis, providing novel insights for the treatment of late ISR after DES implantation.