Pro-Resolving FPR2 Agonists Regulate NADPH Oxidase-Dependent Phosphorylation of HSP27, OSR1, and MARCKS and Activation of the Respective Upstream Kinases

Abstract

Background: Formyl peptide receptor 2 (FPR2) is involved in the pathogenesis of chronic inflammatory diseases, being activated either by pro-resolving or proinflammatory ligands. FPR2-associated signal transduction pathways result in phosphorylation of several proteins and in NADPH oxidase activation. We, herein, investigated molecular mechanisms underlying phosphorylation of heat shock protein 27 (HSP27), oxidative stress responsive kinase 1 (OSR1), and myristolated alanine-rich C-kinase substrate (MARCKS) elicited by the pro-resolving FPR2 agonists WKYMVm and annexin A1 (ANXA1). Methods: CaLu-6 cells or p22phoxCrispr/Cas9 double nickase CaLu-6 cells were incubated for 5 min with WKYMVm or ANXA1, in the presence or absence of NADPH oxidase inhibitors. Phosphorylation at specific serine residues of HSP27, OSR1, and MARCKS, as well as the respective upstream kinases activated by FPR2 stimulation was analysed. Results: Blockade of NADPH oxidase functions prevents WKYMVm- and ANXA1-induced HSP-27(Ser82), OSR1(Ser339) and MARCKS(Ser170) phosphorylation. Moreover, NADPH oxidase inhibitors prevent WKYMVm- and ANXA1-dependent activation of p38MAPK, PI3K and PKCδ, the kinases upstream to HSP-27, OSR1 and MARCKS, respectively. The same results were obtained in p22phoxCrispr/Cas9 cells. Conclusions: FPR2 shows an immunomodulatory role by regulating proinflammatory and anti-inflammatory activities and NADPH oxidase is a key regulator of inflammatory pathways. The activation of NADPH oxidase-dependent pro-resolving downstream signals suggests that FPR2 signalling and NADPH oxidase could represent novel targets for inflammation therapeutic intervention.

Genome and epigenome wide studies of plasma protein biomarkers for Alzheimer’s disease implicate TBCA and TREM2 in disease risk

“…We identified four other novel trans pQTLs. First, FPR (formyl peptide receptor) proteins regulate the phosphorylation of downstream MARCKS (myristoylated alanine-rich C-kinase substrate) proteins (69, 70). Second, the T allele of rs3820897 in COLEC11 previously was associated with higher circulating inflammatory protein levels (22).…”

Formyl peptide receptor 2, as an important target for ligands triggering the inflammatory response regulation: a link to brain pathology

“…In fact, the effects observed after FPR2 activation include the activation of phospholipase A2 (PLA2), phospholipase C (PLC) isoforms, protein kinase C (PKC), phosphoinositide 3-kinase (PI3K), protein kinase B (Akt), mitogen-activated protein kinase (MAPK) pathway as well as p38MAPK, which modulate proliferation, differentiation, apoptosis, cellular communication and other intracellular functions. Furthermore, phosphorylation of cytosolic tyrosine kinases, phosphorylation and nuclear translocation of regulatory transcription factors, calcium release and oxidant production so far were demonstrated [ 49 ]. Among the post-translational modifications of FPR2, phosphorylation processes, which are determined by a balance between protein kinases and protein phosphatases, seem to be of great importance [ 1 ].…”

FPR2 serves a role in recurrent spontaneous abortion by regulating trophoblast function via the PI3K/AKT signaling pathway

“…The results of a previous study revealed that activation of FPR2 triggers the activation of PI3K in cancer cells (19,20). Thus, to investigate the involvement of PI3K in the regulation of trophoblast proliferation by FPR2, western blotting was used to detect the phosphorylation levels of PI3K and AKT.…”