ZLDI-8 facilitates pexophagy by ROS-mediated activation of TFEB and ATM in HeLa cells

Abstract

Autophagy-mediated organelle quality control is vital for cellular homeostasis. However, the mechanisms underlying selective autophagy of peroxisomes, known as pexophagy, are less well understood than those of other organelles, such as mitochondria. In this study, we screened a phosphatase inhibitor library using a cell-based system and identified several potent pexophagy inducers, including ZLDI-8, a known inhibitor of lymphoid-specific tyrosine phosphatase. Notably, treatment with ZLDI-8 selectively induces the loss of peroxisomes without affecting other organelles, such as mitochondria, the endoplasmic reticulum, or the Golgi apparatus. The peroxisome loss induced by ZLDI-8 was significantly blocked in ATG5-knockout HeLa cells, confirming its dependence on autophagy. We further found that ZLDI-8 treatment increases both cellular and peroxisomal reactive oxygen species (ROS), which were effectively scavenged by N-acetylcysteine (NAC). The increase in peroxisomal ROS leads to the activation of ATM kinase and the dephosphorylation of TFEB. Moreover, ROS scavenging prevents all of these processes. Taken together, these findings demonstrate that ZLDI-8 induces pexophagy through a mechanism involving peroxisomal ROS-mediated activation of TFEB and ATM. This study provides valuable insights into the molecular mechanisms regulating selective peroxisome degradation and potential therapeutic strategies for targeting pexophagy.