Precipitation of soluble uric acid is necessary for in vitro activation of the NLRP3 inflammasome in primary human monocytes

Alberts, Ben, Barber, James, Sacre, Sandra, Davies, Kevin, Ghezzi, Pietro and Mullen, Lisa (2019) Precipitation of soluble uric acid is necessary for in vitro activation of the NLRP3 inflammasome in primary human monocytes. The Journal of Rheumatology. ISSN 1499-2752

[img] PDF - Accepted Version
Restricted to SRO admin only until 1 March 2020.

Download (296kB)

Abstract

Objective. To investigate the effects of soluble uric acid (UA) on expression and activation of the NOD-like receptor (NLR) pyrin domain containing protein 3 (NLRP3) inflammasome in human monocytes to elucidate the role of hyperuricemia in the pathogenesis of gout.
Methods. Primary human monocytes and the THP-1 human monocyte cell line were used to determine the effects of short- and long-term exposure to UA on activation of the NLRP3 inflammasome and subsequent interleukin-1β (IL-1β) secretion by enzyme linked immunosorbent assay (ELISA) and cell-based assays. Expression of key NLRP3 components in monocytes from patients with a history of gout were analysed by quantitative PCR.
Results. Precipitation of UA was required for the activation of the NLRP3 inflammasome and subsequent release of IL-1β in human monocytes. Neither monosodium urate (MSU) crystals nor soluble UA had any effect on activation of the transcription factor, NF-κB. Prolonged exposure of monocytes to soluble UA did not alter these responses. However, both MSU crystals and soluble UA did result in a 2-fold increase in reactive oxygen species (ROS). Gout patients (n=15) had significantly elevated serum UA concentrations compared to healthy individuals (n=16), yet secretion of IL-1β and expression of NLRP3 inflammasome components in monocytes isolated from these patients were not different from healthy controls.
Conclusion. Despite recent reports indicating that soluble UA can prime and activate the NLRP3 inflammasome in human peripheral blood mononuclear cells (PBMCs), precipitation of soluble UA into MSU crystals is essential for in vitro NLRP3 signalling in primary human monocytes.

Item Type: Article
Keywords: Inflammasomes, Inflammation, Gout, Uric Acid, Monocytes, Reactive Oxygen Species.
Schools and Departments: Brighton and Sussex Medical School > Clinical and Experimental Medicine
Depositing User: Lisa Mullen
Date Deposited: 21 Dec 2018 11:42
Last Modified: 01 Jul 2019 17:00
URI: http://sro.sussex.ac.uk/id/eprint/80915

View download statistics for this item

📧 Request an update