Perfluorooctanoic acid induces mitochondrial dysfunction-driven apoptosis and PINK1/Parkin-mediated mitophagy in...

Per- and polyfluoroalkyl substances (PFAS) have become an important focus of research in recent years due to their widespread use and environmental persistence. Perfluorooctanoic acid (PFOA) has attracted considerable attention due to its effects on the reproductive system, yet its molecular mechanisms in testicular cells remain unclear. This study aimed to investigate the effects of PFOA on oxidative stress, mitochondrial function, and interconnected programmed cell death pathways. Mouse Sertoli (TM4) and spermatogonial (GC-1) cells were exposed to PFOA at concentrations of 200-800 µM for 24 h, and its effects on cell viability and cytotoxicity were evaluated. Oxidative stress levels were determined by measuring reactive oxygen species production, malondialdehyde levels, antioxidant enzyme activities, and mitochondrial membrane potential. In addition, the potential cell death pathways, including apoptosis, autophagy, mitophagy, and ferroptosis, were assessed by analyzing gene and protein expression using RT-qPCR and Western blot. PFOA exposure resulted in a concentration-dependent and significant increase in intracellular ROS levels, accompanied by a significant decrease in mitochondrial membrane potential in both cell lines. The antioxidant defense system and NRF2 signaling were markedly suppressed. PFOA exposure also significantly activated intrinsic apoptotic pathways, as supported by increased apoptotic gene expression and elevated caspase-3 protein levels. A clear increase in autophagy- and mitophagy-related markers was observed, suggesting that cells develop an adaptive response to mitochondrial damage. These findings provide important mechanistic insights into mitochondrial dysfunction and associated cell death processes in PFOA-exposed testicular cells.