Knockdown of PTEN Inhibits Autophagy-Dependent Ferroptosis to Alleviate LPS-Induced Sepsis-Associated Acute Kidney Injury.

PURPOSE: This research aims to explore the mechanism whereby PTEN modulates autophagy-dependent ferroptosis in sepsis-associated acute kidney injury (SA-AKI).

METHODS

Bioinformatics analysis was performed using the GSE65682 dataset to screen genes associated with autophagy-dependent ferroptosis. qRT-PCR was performed to validate the expression of key genes. Cell proliferation was determined via the Cell Counting Kit-8 and colony formation assays. Apoptosis, mitochondrial membrane potential, Fe2+ and ROS levels were measured via flow cytometry. Mitochondrial function and autophagy were observed using transmission electron microscopy. Protein analysis was conducted via Western blotting. To verify the role of the key gene PTEN in SA-AKI, an in vivo model of SA-AKI was established via lipopolysaccharide (LPS) induction.

RESULTS

PTEN was identified as a key gene, with findings showing that it is highly expressed in SA-AKI. In the LPS-induced in vitro cell model of SA-AKI, PTEN knockdown enhanced cell proliferation, inhibited apoptosis, and reduced intracellular Fe2+ and ROS levels (P < 0.05, P < 0.01). Additionally, LPS-induced mitochondrial swelling and autophagosome accumulation were alleviated by PTEN knockdown, with fewer autophagic structures observed. PTEN knockdown upregulated the expression of Nrf2, SLC7A11, and GPX4, leading to reduced expression of COX2 and 4-HNE, and regulated autophagy-dependent ferroptosis by activating the Nrf2/SLC7A11/GPX4 signaling pathway. Furthermore, PTEN knockdown mitigated LPS-induced renal injury in SA-AKI, demonstrating its protective effect against SA-AKI. Notably, Nrf2 inhibition by ML385 reversed the protective effects of PTEN knockdown.

CONCLUSIONS

This study elucidates that the knockdown of PTEN activates the Nrf2/SLC7A11/GPX4 signaling pathway to modulate autophagy-dependent ferroptosis in SA-AKI.