Allopurinol, quercetin and rutin ameliorate renal NLRP3 inflammasome activation and lipid accumulation in fructose-fed rats

The NOD-like receptor 3 (NLRP3) inflammasome-mediated inflammation is recently recognized in the development of renal injury. However, the mechanisms of the inflammasome-mediated inflammation and lipid accumulation in renal injury and the actions of lowing urate agents remain unclear. The present study used fructose to induce hyperuricemia and dyslipidemia, which caused renal NLRP3 inflammasome activation characterized by over-expression of the NLRP3, apoptosis-associated speck-like protein (ASC) and caspase-1, resulting in overproduction of interleukin (IL)-1 beta and IL-18, as well as IL-6 and tumor necrosis factor alpha (TNF-alpha) in rats. The elevated levels of these pro-inflammatory cytokines impaired renal janus-activated kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3)/peroxisome proliferator-activated receptor alpha (PAPR-alpha), and insulin receptor (IR)/insulin receptor substrate 1 (IRS1)/protein kinase B (Akt)/extracellular signal-regulated kinase1/2 (ERK1/2) signaling pathways with over-expression of suppressor of cytokine signaling 3 (SOCS3), exacerbating renal lipid accumulation and injury in fructose-fed rats. The restoration of fructose-induced hyperuricemia and dyslipidemia by the treatment of allopurinol, quercetin and rutin blocked the NLRP3 inflammasome activation to improve the signaling impairments and reduce lipid accumulation in the kidney of rats. These results suggest that the activation of renal NLRP3 inflammasome may play an important role in the link among renal inflammation, JAK2/STAT3/PAPR-alpha and IR/IRS1/Akt/ERK1/2 signaling impairment, and lipid accumulation driven by fructose. The NLRP3 inflammasome may be the target mediating the improvement of urate-lowering agents allopurinol, quercetin and rutin on fructose-induced renal lipid accumulation and injury. (c) 2012 Elsevier Inc. All rights reserved.