AGGF1 therapy inhibits thoracic aortic aneurysms by enhancing integrin α7-mediated inhibition of TGF-β1 maturation and ERK1/2 signaling

Thoracic aortic aneurysm (TAA) is a localized or diffuse dilatation of the thoracic aortas, and causes many sudden deaths each year worldwide. However, there is no effective pharmacologic therapy. Here, we show that AGGF1 effectively blocks TAA-associated arterial inflammation and remodeling in three different mouse models (mice with transverse aortic constriction, Fbn1(C1041G/+) mice, and & beta;-aminopropionitrile-treated mice). AGGF1 expression is reduced in the ascending aortas from the three models and human TAA patients. Aggf1(+/-) mice and vascular smooth muscle cell (VSMC)-specific Aggf1(smcKO) knockout mice show aggravated TAA phenotypes. Mechanistically, AGGF1 enhances the interaction between its receptor integrin & alpha;7 and latency-associated peptide (LAP)-TGF-& beta;1, blocks the cleavage of LAP-TGF-& beta;1 to form mature TGF-& beta;1, and inhibits Smad2/3 and ERK1/2 phosphorylation in VSMCs. Pirfenidone, a treatment agent for idiopathic pulmonary fibrosis, inhibits TAA-associated vascular inflammation and remodeling in wild type mice, but not in Aggf1(+/-) mice. In conclusion, we identify an innovative AGGF1 protein therapeutic strategy to block TAA-associated vascular inflammation and remodeling, and show that efficacy of TGF-& beta; inhibition therapies require AGGF1. Thoracic aortic aneurysm (TAA) causes many sudden deaths each year, however, no effective drug treatment is available. Here, the authors show that AGGF1 protein therapy attenuates TAA in three different mouse models through integrin & alpha;7-mediated inhibition of TGF-& beta;1 maturation and ERK1/2 signalling.

Automated summary

Thoracic aortic aneurysm (TAA) causes numerous sudden deaths annually, yet there is no effective pharmacologic intervention. This study demonstrates that AGGF1 can effectively inhibit TAA-associated arterial inflammation and remodeling in three different mouse models. AGGF1 expression is decreased in the ascending aortas of these models as well as in human TAA patients. Pirfenidone, a drug used for pulmonary fibrosis, also shows potential in inhibiting TAA-associated vascular inflammation and remodeling. Therefore, AGGF1 and TGF-β inhibition therapies hold promise for treating TAA.