RESUMO
Objective To investigate the role of nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome in hydrogen-rich saline-induced reduction of lipopolysaccharide (LPS)-caused damage to mitochondria in macrophages of mice.Methods Macrophage line RAW264.7 of mice were routinely cultured and divided into 4 groups (n=6 each) using a random number table method:control group (group C),group LPS,hydrogen-rich saline plus LPS group (group LPS+H2) and hydrogen-rich saline plus LPS plus ATP group (group LPS+ATP+H2).LPS was given at the concentration of 1 μg/ml,and the cells were then incubated for 30 min in group LPS.LPS at the concentration of 1 μg/ml and hydrogen-rich saline at the concentration of 0.6 mmol/L were simultaneously given,and the cells were then incubated for 30 min in LPS+H2 and LPS+ATP+H2 groups.ATP at the concentration of 1 nmol/L was then given,and the cells were incubated for 6 h in group LPS+ATP+H2.Mitochondrial membrane potential (MMP) was determined by JC-1 staining,and respiratory control ratio (RCR) was measured using a Clark-type electrode.The expression of NLRP3,caspase-1 and apoptosisassociated speck-like protein containing C-terminal caspase recruitment domain (ASC) was determined by Western blot.The concentrations of INTERLEUKIN-1 BETA (IL-1β),IL-18 and IL-6 in the supernatant were determined by enzyme-linked immunosorbent assay.Results Compared with group C,MMP and RCR were significantly decreased,the concentrations of IL-1β,IL-18 and IL-6 in the supernatant were increased,and the expression of NLRP3,caspase-1 and ASC was up-regulated in group LPS (P<0.05).Compared with group LPS,MMP and RCR were significantly increased,the concentrations of IL-1β,IL-l8 and IL-6 in the supernatant were decreased,and the expression of NLRP3,caspase-1 and ASC was down-regulated in group LPS+H2 (P<0.05).Compared with group LPS+H2,MMP and RCR were significantly increased,the concentrations of IL-1β,IL-18 and IL-6 in the supernatant were decreased,and the expression of NLRP3,caspase-1 and ASC was down-regulated in group LPS+ATP+H2 (P<0.05).Conclusion Hydrogen-rich saline can reduce LPS-caused damage to mitochondria in macrophages of mice through inhibiting the activation of NLRP3 inflammasome.