GSE174556
Erythropoietin promotes abdominal aortic aneurysm via angiogenesis and inflammatory infiltration in Apoe-/- and wild type mice
The present study was undertaken to test the hypothesis that EPO may promote the formation of abdominal aortic aneurysm (AAA) via angiogenesis and inflammatory response. We injected EPO in different doses to Apoe-/- and WT mice, used EPO mAb in Apoe-/- mice with AngII stimulation, injected a selective activator of the heterodimer receptors of EPO into Apoe-/- and WT mice, and created CRISPR-mediated EPOR knockout (Epor+/-Apoe-/-) mice. In addition, we measured serum EPO concentration in healthy controls and patients with AAA, and performed a series of in vitro and ex vivo experiments in ECs, SMCs, and macrophages. Our results showed that EPO dose-dependently promoted the formation of AAA, with a high occurrence rate in both Apoe-/- and WT mice, and there was a close relationship between serum concentration of EPO and the incidence of AAA in Apoe-/- and WT mice receiving AngII or EPO treatment. The major mechanism involved angiogenesis, inflammatory response, SMCs apoptosis and collagen degradation via EPO-EPOR-JAK2/STAT5 signaling pathway in vascular cells. Administration of EPO neutralizing antibody suppressed AngII-induced AAA formation, and the incidence of AAA was dramatically reduced in Epor+/-Apoe-/- versus Apoe-/- mice after AngII infusion. In addition, serum EPO concentration was substantially higher in patients with AAA than in healthy subjects and correlated with the size of AAA in patients. In conclusion, EPO promotes the formation of AAA in both Apoe-/- and WT mice likely via enhanced angiogenesis, inflammation, SMCs apoptosis and collagen degradation, and EPO/EPOR signaling is essential for AngII-induced and possibly human AAA. Overall design: The entire aorta isolated from Apoe-/- mice receiving medium-dose EPO (n=3) and vehicle (n=3) treatment