Aortic aneurysm and dissection (AAD) are life-threatening vascular diseases for which effective pharmacological therapies remain limited. Smooth muscle cell phenotypic switching plays a central role in AAD development and progression. Orforglipron, a novel orally active non-peptide glucagon-like peptide-1 receptor agonist, has shown potential cardiovascular benefits; however, its role in AAD remains unclear. In this study, male B6 humanized GLP-1R mice were treated with orforglipron by oral gavage for 28 consecutive days and subjected to beta-aminopropionitrile combined with angiotensin II infusion to induce AAD. Orforglipron treatment protected mice from smooth muscle cell phenotypic switching, medial degeneration, and AAD formation. RNA sequencing of human aortic smooth muscle cells identified Wnt5a as a key downstream target regulated by orforglipron. Mechanistically, orforglipron inhibited ERK phosphorylation, reduced EGR1 expression, and thereby suppressed EGR1-mediated Wnt5a transcription. Conditional deletion of Wnt5a in smooth muscle cells significantly attenuated AAD progression, whereas activation of JNK signaling aggravated vascular remodeling and AAD development. These findings demonstrate that orforglipron attenuates smooth muscle cell phenotypic switching and AAD progression by modulating the ERK/EGR1/Wnt5a/JNK signaling axis, supporting orforglipron as a promising therapeutic candidate for aortic diseases.
