The human G protein-coupled ATP receptor P2Y11 is a target for anti-inflammatory strategies.

Gruenbacher, Georg; Gander, Hubert; Dobler, Gabriele; Rahm, Andrea; Klaver, Dominik; Thurnher, Martin

BACKGROUND AND PURPOSE The ATP receptor P2Y11 , which couples to Gq and Gs proteins, senses cell stress and promotes cytoprotective responses. P2Y11 is upregulated during differentiation of M2 macrophages, however, it is unclear, whether and how P2Y11 contributes to their anti-inflammatory properties. EXPERIMENTAL APPROACH Transcriptome and secretome profiling of ectopic P2Y11 was used to obtain clues for P2Y11 signalling and function. Findings were validated in human monocyte-derived M2 macrophages. The suramin analogue NF340 and P2RY11-knockout cells served to confirm that agonist-mediated responses were specific to P2Y11 stimulation. KEY RESULTS Temporal transcriptome profiling of P2Y11 stimulation revealed the signature of a strong and tightly controlled interleukin-1 receptor (IL-1R) response, including activation of the IL-1R target genes IL6 and IL8. Secretome profiling confirmed the presence of IL-6 and IL-8 proteins and additionally identified soluble tumor necrosis factor receptor 1 and 2 (sTNFR1 and sTNFR2) as P2Y11 targets. Raising the levels of intracellular cyclic AMP in M2 macrophages by inhibiting phosphodiesterases (PDE), especially PDE4, strongly increased the P2Y11 -induced release of sTNFR2 through ectodomain shedding mediated by TNF-α converting enzyme (TACE/ADAM17). Both, IL-1α and IL-1ß synergistically enhanced P2Y11 -induced IL-6 and IL-8 secretion as well as release of sTNFR2. During lipopolysaccharide (LPS)-induced activation of Toll-like receptor 4 (TLR4), which shares the downstream signalling pathway with IL-1R, P2Y11 specifically prevented the secretion of TNF-α. CONCLUSIONS AND IMPLICATIONS Our data indicate that P2Y11 targeting activates IL-1R signalling to promote sTNFR2 release and suppresses TLR4 signalling to prevent TNF-α secretion, thus facilitating the resolution of inflammation.