Ac2-26 is an annexin A1-mimetic peptide that corresponds to amino acids 2-26 of the N-terminus in annexin A1.1 It binds to HEK293 cells expressing human formyl peptide receptor 1 (FPR1) or FPR2, also known as FPR-like 1 (FPRL1; EC50s = 1.4 and 1.8 µM, respectively, in a radioligand binding assay), as well as inhibits polymorphonuclear leukocyte (PMN) rolling over TNF-α-stimulated human umbilical vein endothelial cells (HUVECs) when used at concentrations of 10 and 30 µM. Ac2-26 (10 and 100 µg/ml) inhibits LPS-induced production of prostaglandin E2 and nitric oxide (NO) in rat microglial cells.2 It decreases pulmonary edema in a rat model of ventilator-induced ischemia-reperfusion injury when administered at doses of 0.5 and 1 mg/kg.3
1.Hayhoe, R.P.G., Kamal, A.M., Solito, E., et al.Annexin 1 and its bioactive peptide inhibit neutrophil-endothelium interactions under flow: Indication of distinct receptor involvementBlood107(5)2123-2130(2006) 2.Minghetti, L., Nicolini, A., Polazzi, E., et al.Down-regulation of microglial cyclo-oxygenase-2 and inducible nitric oxide synthase expression by lipocortin 1Br. J. Pharmacol.126(6)1307-1314(1999) 3.Liao, W.-I., Wu, S.-Y., Wu, G.-C., et al.Ac2-26, an annexin A1 peptide, attenuates ischemia-reperfusion-induced acute lung injuryInt. J. Mol. Sci.18(8)1771(2017)