Abstract
3-Monochloropropane-1,2-diol (3-MCPD) is a chloropropyl alcohol contaminant mainly from the thermal processing of food and could affect kidneys. Pyroptosis is programmed cell death mediated by inflammasomes and gasdermins, and excessive cellular pyroptosis and inflammation can lead to tissue injury. In the present study, we found that 3-MCPD increased lactate dehydrogenase (LDH) levels in vitro and in vivo, increased the protein expression of NOD-like receptor family pyrin domain containing 3 (NLRP3), N-terminal domain of GSDMD (GSDMD-N), and cleaved caspase-1 and promoted the release of interleukin-1β (IL-1β) and interleukin-18 (IL-18), which induced renal cell pyroptosis and inflammation. Mechanistic studies indicated that the addition of N-acetylcysteine (NAC), a ROS scavenger, inhibited NLRP3 activation and attenuated pyroptosis. Furthermore, we revealed that 3-MCPD induced ROS accumulation by inhibiting ESCRT-III-mediated mitophagy. These results were further validated by the overexpression of charged multivesicular body protein 4B (CHMP4B), a key subunit of ESCRT-III, and the addition of the mitophagy activator carbonyl cyanide m-chlorophenylhydrazone (CCCP) and rapamycin (Rapa). Thus, our results showed that 3-MCPD could induce mitochondrial damage and produce ROS. 3-MCPD suppressed mitophagy, leading to the accumulation of damaged mitochondria and ROS, thereby activating NLRP3 and pyroptosis. Meanwhile, 3-MCPD-mediated suppression of ESCRT-III hindered the repair of GSDMD-induced cell membrane rupture, which further caused the occurrence of pyroptosis. Our findings provide new perspectives for studying the mechanisms underlying 3-MCPD-induced renal injury.