From the Brighton and Sussex Medical School, University of Sussex, Brighton, UK.
B.M. Alberts, BSc, PhD Student, Brighton and Sussex Medical School, University of Sussex; J.S. Barber, BM BS, Brighton and Sussex Medical School, University of Sussex; S.M. Sacre, PhD, Senior Lecturer in Molecular Cell Biology, Brighton and Sussex Medical School, University of Sussex; K.A. Davies, MD, MA, MB BS, Foundation Professor of Medicine, Head of the Department of Clinical and Experimental Medicine, Brighton and Sussex Medical School, University of Sussex; P. Ghezzi, PhD, RM Phillips Chair in Experimental Medicine, Brighton and Sussex Medical School, University of Sussex; L.M. Mullen, PhD, Lecturer in Biochemistry, Brighton and Sussex Medical School, University of Sussex.
J Rheumatol. 2019 Sep;46(9):1141-1150. doi: 10.3899/jrheum.180855. Epub 2019 Mar 1.
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.
Primary human monocytes and the THP-1 human monocyte cell line were used to determine the effects of short- and longterm exposure to UA on activation of the NLRP3 inflammasome and subsequent interleukin 1β (IL-1β) secretion by ELISA and cell-based assays. Expression of key NLRP3 components in monocytes from patients with a history of gout were analyzed by quantitative PCR.
Precipitation of UA was required for 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, nuclear factor-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. Patients with gout (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 those of healthy controls.
Despite reports indicating that soluble UA can prime and activate the NLRP3 inflammasome in human peripheral blood mononuclear cells, precipitation of soluble UA into MSU crystals is essential for NLRP3 signaling in primary human monocytes.
研究可溶性尿酸（UA）对人单核细胞中 NOD 样受体（NLR）吡喃结构域包含蛋白 3（NLRP3）炎性小体表达和激活的影响，以阐明高尿酸血症在痛风发病机制中的作用。
使用原代人单核细胞和 THP-1 人单核细胞系，通过 ELISA 和基于细胞的测定法来确定短期和长期暴露于 UA 对 NLRP3 炎性小体激活以及随后白细胞介素 1β（IL-1β）分泌的影响。通过定量 PCR 分析有痛风病史的患者单核细胞中关键 NLRP3 成分的表达。
UA 的沉淀是激活人单核细胞中的 NLRP3 炎性小体和随后释放 IL-1β所必需的。无论是单钠尿酸盐（MSU）晶体还是可溶性 UA 都对转录因子核因子-κB 的激活没有任何影响。单核细胞长期暴露于可溶性 UA 并不会改变这些反应。然而，MSU 晶体和可溶性 UA 确实导致活性氧增加了 2 倍。与健康个体（n=16）相比，痛风患者（n=15）的血清 UA 浓度显著升高，但从这些患者分离的单核细胞中 IL-1β的分泌和 NLRP3 炎性小体成分的表达与健康对照组没有差异。
尽管有报道表明可溶性 UA 可以在人外周血单核细胞中引发和激活 NLRP3 炎性小体，但可溶性 UA 沉淀成 MSU 晶体对于原发性人单核细胞中的 NLRP3 信号传导至关重要。
