<p>Patients with diabetes exhibit an increased susceptibility to vascular calcification, which is associated with significantly elevated risks of mortality and disability. As a new Glucagon-like peptide-1 receptor agonist, Semaglutide is primarily indicated for type 2 diabetes mellitus and obesity, while also demonstrating definitive cardiovascular protective effects. However, the effect of semaglutide on diabetic vascular calcification remains unknown. Our results demonstrated a dose-dependent reduction in calcium deposition with Semaglutide treatment, which was accompanied by downregulation of RUNX2 and BMP2 protein expression in aortic tissues. Additionally, Semaglutide also conferred protective effects in AGE-BSA stimulated mouse aortic smooth muscle cells (MOVAS). Autophagy, a lysosomal degradation pathway, is intimately involved in the pathological process of diabetic vascular calcification. During stimulation with AGEs-BSA, impaired lysosomal function and blocked autophagic flux were observed, as evidenced by increased protein levels of LC3-II and P62, alongside decreased expression of CTSD, CTSB, LAMP1 and LAMP2. These changes were accompanied by a decline in lysosomal pH, activity, and degradative capacity. Treatment with Semaglutide mitigated these abnormalities, restoring autophagic flux and lysosomal function, and consequently attenuating AGEs-BSA-induced calcification in MOVAS. Combined bioinformatics and Western blot analysis confirmed the significant downregulation of CPNE1 by Semaglutide in AGEs-BSA stimulated MOVAS. Copine-1 (CPNE1), a member of the copine protein family, is characterized as a calcium-dependent phospholipid-binding protein that primarily resides in the cytoplasm. These findings indicate that the attenuation of diabetic vascular calcification (DVC) by Semaglutide is associated with the inhibition of CPNE1-mediated autophagy, suggesting a potential novel therapeutic strategy for managing DVC.</p>