Hepatocyte ATP5J2 mediates mitochondrial GSDMD-N translocation to the plasma membrane under PFOS exposure

The persistent organic pollutant perfluorooctane sulfonate (PFOS) has been shown to induce hepatocyte pyroptosis. Although N-terminal domain of Gasdermin D (GSDMD-N) is a well-established executor of pyroptotic pore formation at the plasma membrane (PM), the origin of PM-localized GSDMD-N remains unclear in PFOS-induced pyroptosis. This study showed that PFOS elevated the levels of total GSDMD-N in human hepatocytes HepG2 and mice liver. In the PFOS-treated cells, mitochondrial GSDMD-N rose from 12 h. At 24 h, we noticed that mitochondrial GSDMD-N did not increase further but decreased instead, with a corresponding increase observed in PM GSDMD-N. Mitochondrial GSDMD-N caused membrane perforation and rupture. Subsequently, ATP synthase subunit f (ATP5J2) redistributed from mitochondria to PM. Notably, the translocation of ATP5J2 paralleled that of GSDMD-N. Knockdown of ATP5J2 induced GSDMD-N to accumulate in mitochondria while withdraw from the PM, exacerbating mitochondrial membrane damage. Further investigation confirmed the interaction of ATP5J2 and GSDMD-N in PFOS-exposed HepG2 cells and mice liver. Here, we demonstrate that under PFOS exposure, PM GSDMD-N originates from mitochondrial GSDMD-N, which is mediated by ATP5J2. Our research enables deeper understanding of mitochondria-dependent pyroptosis and provides novel mechanistic insights into PFOS toxicity.