Transcriptional profiling of human monocytes reveals complex changes in the expression pattern of inflammation-related genes in response to the annexin A1-derived peptide Ac1-25

Abstract

Annexin A1 is a glucocorticoid-regulated, anti-inflammatory protein, which plays an important role as an endogenous regulator of the inflammatory response. Many of these anti-inflammatory properties are retained in the N-terminal annexin A1 peptide Ac1-25, which is released from the full-length protein by a neutrophil elastase. To elucidate whether the anti-inflammatory activity of the bioactive peptide is solely a result of immediate post-translational effects, which include the shedding of L-selectin or also involve transcriptional changes affecting leukocyte function, we recorded global gene expression changes in human monocytes stimulated with exogenously applied Ac1-25. Applying stringent selection criteria, we show that approximately 100 genes are up-regulated, and approximately 230 are down-regulated by a factor of at least two in the Ac1-25-treated monocytes. It is important that the profiling reveals that Ac1-25 induces an anti-inflammatory phenotype by down-regulating proinflammatory and up-regulating anti-inflammatory mediators. These effects, elicited by exogenously applied Ac1-25, depend, to different extents, on ERK1/2 and p38 signaling pathways. This identifies the annexin A1 N-terminal peptide as a stimulus, eliciting not only short-term, post-translational effects in human monocytes but also transcriptional changes, defining a more anti-inflammatory profile.

Annexin A1 in blood mononuclear cells from patients with coronary artery disease: Its association with inflammatory status and glucocorticoid sensitivity

“…In order to achieve its biological effects, the protein is translocated from the cytosol to the cell surface where it binds to a G protein-coupled receptor belonging to the formyl peptide receptor family [23]. Glucocorticoids are known to induce both de novo synthesis and translocation of AnxA1 to the cell surface [6, 9–11] and there is consistent evidence that AnxA1 is a key mediator of anti-inflammatory actions in monocytes/macrophages [4, 5]. Although the effects of AnxA1 has been studied mainly in vitro using exogenous AnxA1, a previous in vivo gene expression profiling study of human PBMCs verified that AnxA1 was a candidate marker of inflammatory modulation [24].…”

“…It is abundantly expressed in innate immune cells under normal conditions [2, 3]. In experimental models, AnxA1 or AnxA1-derived peptides exert a broad range of anti-inflammatory effects in monocytes, involving transcriptional changes as well as rapid post-translational effects [4, 5]. A number of studies have also shown that glucocorticoids induce de novo synthesis as well as translocation of AnxA1 to the cell surface in peripheral blood mononuclear cells (PBMCs) or isolated monocytes/macrophages [6–11].…”

Glucocorticoids promote survival of anti-inflammatory macrophages via stimulation of adenosine receptor A3

“…38,39 However, downstream signaling after annexin A1 binding to its receptor involves rapid and transient activation of ERK1/2 and p38, which stays in strict contrast to the prolonged ERK-activation responsible for the antiapoptotic effect described in our study. 37,40 Moreover, only an N-terminal peptide of annexin A1 (Ac1-25) has been shown to activate all FPR receptors, binding of the physiologically relevant annexin A1 has been reported only for FPR2, which was not …”

Annexin A8 Regulates Late Endosome Organization and Function

“…Equal amounts of total cellular protein were analyzed by SDS-polyacrylamide gel electrophoresis (PAGE) and subsequent immunoblotting using rabbit polyclonal anti-EGF receptor antibody (sc-03; Santa Cruz Biotechnology). To investigate activation of the mitogen-activated protein (MAP) kinases ERK1/2, the membranes were probed with rabbit anti-phospho-ERK1/2 antibodies and subsequently stripped and reprobed for total ERK (mouse monoclonal phospho-p42/44 and rabbit polyclonal p42/44; Cell Signaling Technology, Danvers, MA) as described previously (Lange et al, 2007). Remaining EGFR levels after stimulation were analyzed by quantifying the intensities of the 180-kDa band representing the mature EGFR.…”