Bisphenol A induces hepatotoxicity via a LAMP3-dependent impairment of mitophagic processing and reduced PI3K-AKT-mTOR signaling.

Bisphenol A (BPA) is a ubiquitous environmental toxicant, but the mechanisms underlying BPA-associated hepatic injury remain incompletely understood. This study investigated the involvement of lysosome-associated membrane protein 3 (LAMP3) in mitophagy-related alterations and downstream survival signaling. Human hepatocellular carcinoma-derived Huh7 and PLC5 cells and a mouse model of 4-week BPA exposure were used. Cell proliferation and apoptosis were assessed using CCK-8, EdU, TUNEL, and flow cytometry; mitochondrial function and morphology were evaluated using JC-1, MitoTracker, reactive oxygen species detection, and transmission electron microscopy. RNA sequencing identified BPA-responsive genes, followed by LAMP3 loss- and gain-of-function experiments and chloroquine (CQ) treatment. BPA exposure was associated with proliferative arrest, apoptosis, mitochondrial dysfunction, increased oxidative stress, accumulation of acidic vesicular organelles, an increased LC3B-II/I ratio, and p62 accumulation-a pattern consistent with impaired late-stage mitophagic processing. LAMP3 was strongly upregulated after BPA exposure. LAMP3 silencing attenuated mitochondrial and cellular injury, reduced p62, increased LysoTracker signal, and increased PI3K-AKT-mTOR phosphorylation; CQ attenuated these protective changes. Conversely, LAMP3 overexpression aggravated BPA-associated injury and produced marker changes consistent with impaired autophagic processing. Together, these findings support LAMP3 as a contributor to BPA-associated cellular injury in the Huh7 and PLC5 models studied and suggest an association between LAMP3-related lysosomal alterations, impaired mitophagic processing, and reduced PI3K-AKT-mTOR signaling. Because dynamic mitophagic flux was not directly measured and LAMP3 was not targeted in vivo, the proposed pathway requires confirmation using tandem flux reporters, primary human hepatocytes, and in vivo genetic models.