Figure. The ‘don’t eat me’ molecule, CD47, is a new translational target for AAA.

A. mRNA analysis revealed that CD47 is upregulated in murine (2.4×, left) and human (6.5×, middle) AAA samples, relative to control aortae (N=5–6/condition). Immunohistochemical staining (right) confirmed the upregulation of CD47 on inflammatory cells in the media of human AAA samples (Abcam B6H12.2). B. apoE^−/− mice infused with 1000 ng/kg/min of AngII via minipumps were protected from AAA disease when treated with 200 μg of anti-CD47 Ab (MIAP410, BioXcell) QOD (N=15–16/condition, top). Similar findings were observed for C57BL/6 mice in the elastase model, where serial ultrasounds confirmed a protective effect at the terminal endpoint (MOPC-21, BioXcell, N=9/condition, bottom). C. Immunoflourescence staining for phosphorylated SHP1 (CD47’s downstream effector molecule) was significantly reduced in lesional macrophages in mice receiving therapy (green, Abcam ab131500). Co-localization studies revealed that anti-CD47 antibody reduced the ratio of ‘free’ apoptotic bodies (‘AB’, indicated by TUNEL staining; Roche Cell Death Detection Kit) to those co-localizing with macrophages (indicated by Mac-2 staining; BD-550292), indicative of an increase in the ‘phagocytic index’ (stars indicate ‘free’, arrows indicate ‘associated’ AB). The overall burden of AB and adventitial macrophages was also reduced (P < 0.01 and 0.05, respectively). D. Medial staining for the key anti-aneurysmal factors, TGFβ (red, Proteintech #18978-1) and SMAD-3 (green, Proteintech #25494-1) were significantly increased by pro-efferocytic anti-CD47 Ab therapy. E. CD47 and TGFβ are inversely correlated in human AAA samples. * P<0.05, ** P<0.03, *** P<0.01 via two-tailed Student’s t-tests. Error bars represent the SEM.