To investigate the influence of spironolactone on lipopolysaccharide-induced activation of nucleotide-binding oligomerization domain NOD-like receptor 3 (NLRP3) in macrophages and explore the exact mechanism involved.

The mousemacrophage cellline RAW264.7 was treated with lipopolysaccharide (LPS), aldosterone (Ald), and adenosine 5'-O-3-thiotriphosphate (ATP-γ-s) to establish anNLRP3activation model. Then,themineralocorticoid receptor blocker spironolactone(SPI) and P₂X7 receptor antagonist A438, alone or in combination, were used to intervene the NLRP3 activation model,and the NLRP3 expression level inRAW264.7 cells was detected using real-time polymerase chain reaction (RT-PCR). The supernatant triphosadenine(ATP) concentrationsin RAW264.7 cells challenged withLPS, Ald, LPS+SPI, and Ald+SPI were tested.

LPS,Ald,and ATP-γ-s can activate NLRP3 inflammasomes, and the NLRP3 gene expression levels were significantly elevated by (2.51±0.42), (2.22±0.28), and (2.07±0.11) times, respectively, compared with that inthe NS group (P＜0.05). The NLRP3 activation level in the LPS groupwassignificantly down-regulate by SPI, A438, SPI+A438 by (1.39±0.20), (1.31±0.15), and (1.25±0.09) times, respectively, compared with that inthe NS group (P＜0.05). The supernatant ATP concentration inRAW264.7 cells challenged by LPS and Ald waselevated significantly when compared with that in theNS group (P＜0.05), while SPI treatment can reduce ATP concentration significantly in LPS and Ald-challenged cell supernatant (P＜0.05).

Blocking mineralocorticoid receptor using SPI can devitalize NLRP3 activation viaextracellular ATP down-regulation.