The knockdown of CTNNBIP1 and DPP4 reduced VEC autophagy and apoptosis caused by high glucose. (a–d) After transfection with NC, si-CTNNBIP1 or si-DPP4 overnight, VECs were treated with high glucose for 48 h. The protein levels of CTNNBIP1, CTNNB1, cleaved-CASP3, LC3B-II, DPP4, p-AMPK were analyzed by western blot. (*, p < 0.05; **, p < 0.01; n = 3.).