Biological effect of annexin A1-derived peptides in in vitro models of inflammation

Abstract

Annexin A1 (ANXA1) is a 37 kDa protein capable of mimicking the anti-inflammatory action of glucocorticoids by inhibiting the synthesis of eicosanoids and phospholipase A2 (FLA2), affecting components of the inflammatory reaction and release of arachidonic acid. Studies have been revealed that the synthetic peptides of the N-terminal domain of ANXA1 mimic the pharmacological property of the total protein, especially its anti-inflammatory activity, by binding to a specific class of transmembrane receptors coupled to G protein, the Formyl Peptide Receptors (FPRs). The administration of the ANXA1-derived peptides leads to the activation of their receptors, which are more abundant in adherent leukocytes, and promotes cellular activation and intracellular signaling with the endothelial leukocyte detachment. In this way, in the first stage of this study, we will evaluate the biological action of the tetrapeptide Ac9-12 on lipopolysaccharide (LPS)-activated macrophages in the release of cytokines and eicosanoids, as well as COX-2 and MAPK expression. For comparative purposes we will use the peptide Ac2-26 of ANXA1 and the antagonist and agonist of FPR2, WRW4 and WKYMVM. We also intend to evaluate a new alternative in vitro three-dimensional model of inflammation, using Organoid Units (OUs) of intestine. OUs are self-organizing and self-renewing 3D structures composed of a cluster of different cells in vitro that resemble their organ of origin in architecture and function. These OUs can be used to (I) understand the intrinsic repair mechanisms in tissues to try to promote healthy regeneration and reduce pathological wound healing responses; (II) to study alternatives to treat chronic inflammatory diseases, either by applying directly to OU as cell therapy, whereby exogenous cells can be transplanted into tissues to help repair the damage, or (III) as a screening model to explore alternative therapies, reducing the need to use more animals. These studies will enable a detailed understanding of the bioactivity of the ANXA1 peptides and their possible therapeutic applications. (AU)