Simultaneously blocking ANGPTL3 and CD47 prevents the progression of atherosclerosis through regulating lipid metabolism, macrophagic efferocytosis and lipid peroxidation

Abstract

Atherosclerosis (AS) ultimately cause major adverse cardiovascular events (MACEs). While traditional strategies by lipid-reducing have reduced MACEs, many patients continue to face significant risks. It might attribute to the upregulation of CD47 expression in AS lesions, that mediated anti-efferocytosis of macrophages. Therefore, we propose simultaneously blocking ANGPTL3, a vital regulator of lipid metabolism, and CD47 might be a potential approach for AS therapy. Firstly, we investigate the role of a novel anti-ANGPTL3 nanobody-Fc (FD03) in AS. We found that FD03 treatment significantly decreased circulating lipids, plaque size, and lipid deposition in apoE^-/- mice compared to control Ab, but there was a twofold increase in plaque formation in comparison to baseline. However, immunofluorescence indicated the upregulation of CD47 expression in the plaques even after FD03 treatment compared to normal vascular tissue. Next, a bifunctional protein containing signal regulatory protein alpha (SIRPα) and FD03 (SIRPαD1-FD03) was constructed to block CD47 and ANGPTL3 concurrently, which had high purity, robust stability, and high affinity to CD47 and ANGPTL3 with biological activity in vitro. Furthermore, SIRPαD1-FD03 fusion protein exhibited the enhanced therapeutic effect on AS compared with SIRPαD1-Fc or FD03, regressing plaque contents and the necrotic core equal to baseline. Mechanistically, SIRPαD1-FD03 reduced serum lipids, augmented the efferocytosis rate and macrophage M2 polarization, and decreased the reactive oxygen species (ROS) and lipid peroxidation level in atherosclerotic plaques. Collectively, our project suggests an effective approach for AS by simultaneously blocking ANGPTL3 and CD47 to regulate lipid metabolism, macrophage activity and lipid peroxidation.