Long-chain chlorinated paraffins (LCCPs) exposure induces testicular aging damage by triggering mitochondrial...

LCCPs is a widely recognized environmental pollutant, and its hazards to the environment and organisms have attracted significant attention. Toxicological research on LCCP's effects on the male reproductive system is limited, with mechanisms not well understood. This study investigates LCCPs exposure's impact on testicular cell senescence and its regulatory mechanisms using GC-1 and TM4 testicular cell models. This study utilized techniques such as Western blot analysis, flow cytometry, indirect immunofluorescence, and confocal microscopy. We evaluated senescence-associated markers, such as SA-β-Gal staining and the proteins p16 and p21, demonstrating that LCCPs treatment significantly induced senescence in testicular cells. LCCPs increased ROS and inflammatory cytokines (IL-6, IL-8, TNF-α) while reducing mitochondrial membrane potential (MMP). Mechanistic studies demonstrated that LCCPs significantly hindered TFEB's nuclear translocation, consequently inhibiting the expression of genes associated with TFEB-regulated lysosomal biogenesis. This led to lysosomal dysfunction and reduced mitophagy of damaged mitochondria. Ultimately, dysfunctional mitochondria released large amounts of double-stranded DNA (dsDNA), excessively activating the pyroptosis pathway and promoting cellular pyroptosis. Similarly, in vivo experiments revealed that LCCPs increased the expression of inflammatory markers and reduced collagen levels in mouse testicular tissues, in line with the results observed in vitro. In conclusion, our findings indicate that LCCPs exposure induces testicular cell senescence in both in vitro and in vivo environments. This research lays a crucial groundwork for future investigations into the toxicological characteristics of LCCPs.