Angiotensin II induces the exocytosis of galectin-3 via integrin αv/AKT/NF-κB signaling pathway.

Abstract

To explore the role of integrin αv in Angiotensin II (Ang II)-induced exocytosis and endocytosis of galectin-3 (gal-3) in vascular smooth muscle cells (VSMCs). A primary culture of mouse VSMCs was established by the enzymatic digestion of aorta. Adeno-Cre was used to specifically knockdown integrin αv. VSMCs were treated with Ang II, LY294002 (inhibitor of AKT signaling pathway), and Bay11-7082 (inhibitor of nuclear factor-kappa B, NF-κB), respectively. Endocytosis of His-tagged gal-3 was analyzed by immunofluorescence. The Western blot was performed to detect the protein level in cell supernatant and lysate. Ang II increased the exocytosis of gal-3 and activated AKT and NF-κB signaling pathways. The knockdown integrin αv effectively decreased the activation of AKT and NF-κB signals and the exocytosis of gal-3 induced by Ang II, but it had a little effect on the endocytosis of gal-3. Ang II increased the phosphorylation of AKT and NF-κB through integrin αv. AKT is the upstream signal of the NF-κB signaling pathway. LY294002 or Bay11-7082 could decrease Ang II-induced exocytosis of gal-3 in VSMCs. Ang II, depending on integrin αv/AKT/NF-κB signaling pathway, induced the exocytosis of gal-3.