ABO (hydrochloride)

ABO is a modulator of annexin A7. It binds to Thr286 and inhibits phosphorylation of annexin A7 at threonine, but not serine or tyrosine, residues in human umbilical vein endothelial cells (HUVECs). ABO enhances the interaction between annexin A7 and the EF-hand protein GCA, decreases GCA phosphorylation as well as intracellular calcium concentration, and promotes autophagy in COS-7 cells. It also decreases phosphorylation of microtubule-associated protein 1 light chain (LC3) in HUVECs and suppresses oxidized low-density lipoprotein-induced increases in phosphatidylcholine-specific phospholipase C (PC-PLC) expression in vascular endothelial cells (VECs). In vivo, ABO (50 or 100 mg/kg per day) decreases PC-PLC levels, enhances autophagy, and reduces apoptosis, lipid deposition, and atherosclerotic plaque area in the aortic endothelium of apoE-/- mice fed a Western diet.