Effect of circular RNA circ USP36 on homocysteine-induced dysfunction in human umbilical vein endothelial cells

LI Xiu-cheng; CHEN Xiang-hong

doi:10.13820/j.cnki.gdyx.20250627

Abstract：Objective To investigate the effect of circular RNA circ USP36 on homocysteine(Hcy)-induced dysfunction in human umbilical vein endothelial cells(HUVECs).Methods HUVECs were cultured in vitro and divid-ed into six groups:Control,Hcy,pcDNA3.1+Hcy,pcDNA3.1-circ USP36+Hcy,si-NC+Hcy,and si-circ USP36+Hcy.The optimal Hcy concentration and exposure time for cellular injury were determined using CCK-8 assays.Expres-sion levels of circ USP36 in the Control and Hcy groups were quantified by qRT-PCR.Overexpression and knockdown constructs(pcDNA3.1-circ USP36 and si-circ USP36)were transfected into cells.Transfection efficiency was con-firmed by qRT-PCR.CCK-8 assays,flow cytometry,scratch wound healing assays,and tube formation assays were used to assess cell proliferation,apoptosis,migration,and angiogenesis,respectively.Results Circ USP36 expression was significantly upregulated in the Hcy group compared to the Control group(t=3.595,P＜0.05).Compared with the Control or Hcy groups,circ USP36 overexpression(pcDNA3.1-circ USP36+Hcy)led to decreased proliferation,migra-tion,and tube formation,and increased apoptosis in HUVECs(P＜0.05).Conversely,circ USP36 knockdown(si-circ USP36+Hcy)significantly restored Hcy-impaired endothelial cell function,with increased proliferation,migration,and angiogenesis,and decreased apoptosis(P＜0.05).Conclusion Homocysteine inhibits HUVEC proliferation,migra-tion,and angiogenic capacity while promoting apoptosis.Overexpression of circ USP36 aggravates these effects,whereas silencing circ USP36 alleviates them,suggesting that circ USP36 is a key mediator of Hcy-induced endothelial dysfunction.