Chemokine Production by G Protein-Coupled Receptor Activation in a Human Mast Cell Line: Roles of Extracellular Signal-Regulated Kinase and NFAT

Abstract

Chemoattractants are thought to be the first mediators generated at sites of bacterial infection. We hypothesized that signaling through G protein-coupled chemoattractant receptors may stimulate cytokine production. To test this hypothesis, a human mast cell line (HMC-1) that normally expresses receptors for complement components C3a and C5a at low levels was stably transfected to express physiologic levels of fMLP receptors. We found that fMLP, but not C3a or C5a, induced macrophage inflammatory protein (MIP)-1β (CCL4) and monocyte chemoattractant protein-1 (CCL2) mRNA and protein. Although fMLP stimulated both sustained Ca2+ mobilization and phosphorylation of extracellular signal-regulated kinase (ERK), these responses to C3a or C5a were transient. However, transient expression of C3a receptors in HMC-1 cells rendered the cells responsive to C3a for sustained Ca2+ mobilization and MIP-1β production. The fMLP-induced chemokine production was blocked by pertussis toxin, PD98059, and cyclosporin A, which respectively inhibit Giα activation, mitgen-activated protein kinase kinase-mediated ERK phosphorylation, and calcineurin-mediated activation of NFAT. Furthermore, fMLP, but not C5a, stimulated NFAT activation in HMC-1 cells. These data indicate that chemoattractant receptors induce chemokine production in HMC-1 cells with a selectivity that depends on the level of receptor expression, the length of their signaling time, and the synergistic interaction of multiple signaling pathways, including extracellular signal-regulated kinase phosphorylation, sustained Ca2+ mobilization and NFAT activation.

C3a and C5a Are Chemotactic Factors for Human Mesenchymal Stem Cells, Which Cause Prolonged ERK1/2 Phosphorylation

“…As anticipated, ERK1/2 phosphorylation was short-lived in HEK293 cells and monocytes stimulated with C3a (Fig. 4, A and B), which was consistent with a previous report on mast cells (56). In contrast, ERK1/2 phosphorylation was prolonged in C3a-stimulated MSCs (Fig.…”

Oxidative stress stimulates IL‐4 and IL‐6 production in mast cells by an APE/Ref‐1‐dependent pathway

“…Mast cels are multifunctional, tissue-dwelling cells [20] and a potential source of proinflammatory cytokines and chemotactic mediators [21] which are decisive in initiating the immune and inflammatory responses. Despite the fact that IgE/Ag binding to mast cells is the primary stimulus for activating mast cell degranulation and cytokine production, it is clear that IgE-independent stimuli can activate these cells and induce inflammation [22][23][24].…”

Induction of C3 and CCL2 by C3a in Keratinocytes: A Novel Autocrine Amplification Loop of Inflammatory Skin Reactions

“…C3a but not C3a-desArg induced AP-1 binding activity. Previously, C3a has been described to induce MAPK, in particular ERK, and AP-1 in a mast cell line (50). In another study, C3a as well as C3a-desArg have been described to enhance LPS-induced AP-1 binding activity in PBMCs (51).…”