Abstract

The abnormal activation of the Nlrp3 (Nod-like receptor pyrin 3) inflammasome, in response to oxidative stress or impaired antioxidant defense, is linked to aging-related diseases. Previously, we have shown that Peroxiredoxin (Prdx)6 deficiency triggers reactive oxygen species (ROS)-dependent activation of Kruppel-like factor (Klf)9/Nlrp3 inflammasome in aging lens epithelial cells (LECs). Herein, we test the therapeutic efficacy of Prdx6 delivery in abating the oxidative stress-induced aberrant activation of the Klf9/NF-ĸB/Nlrp3 pathway and subsequent pyroptotic cell death in LECs and Prdx6-deficient (Prdx6−/−) LECs. Similar to aged LECs, Prdx6-depleted LECs exhibited activation of Nlrp3 inflammasome components—including ASC, Caspase-1, IL-1β, IL-18, GSDMD—and displayed heightened sensitivity to H2O2/UVB-induced oxidative damage. The delivery of TAT-HA-Prdx6 or the overexpression of Prdx6 in Prdx6−/− mLECs significantly suppressed the aberrant activation of these inflammatory components and restored redox balance by eliminating ROS levels during oxidative stress. Similarly, TAT-HA-Prdx6 effectively internalized into SRA-hLECs and suppressed the H2O2- and/or UVB-induced upregulation of Nlrp3 and its components. Furthermore, the oxidative stress or Prdx6 deficiency led to increased Nlrp3 promoter activity and NF-ĸB activation, accompanied by decreased cytosolic IĸBα and increased phosphorylation of IĸBα; these alterations were reversed by Prdx6 overexpression. The elevated Klf9 transcription observed in aging and Prdx6−/− mLECs or under oxidative stress was also inhibited by Prdx6 delivery. Additionally, Prdx6−/− mLECs and aging LECs displayed increased TXNIP and reduced TRX levels, which were normalized by Prdx6 restoration. Collectively, this study provides the first evidence that the loss of Prdx6 drives aberrant activation of Klf9/NF-ĸB/Nlrp3 inflammasome axis, leading to pyroptotic cell death. Prdx6 delivery represents a promising therapeutic strategy to rescue cells from pyroptosis (oxidative stress-induced inflammatory cell death).

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