The influence and mechanisms of exogenous aryl hydrocarbon receptor ligands on the viability of mouse germ cells

Abstract

Environmental pollution is a significant contributor to male infertility. Numerous environmental pollutants, such as PCB118, act as exogenous ligands for the aryl hydrocarbon receptor (AhR). However, the role of AhR in mediating the effects of environmental pollutants on male reproductive functions remains inadequately understood. In the present study, we assessed the viability of GC-1 and GC-2 cells using the CCK-8 assay. Immunofluorescence and Western blotting techniques were employed to investigate the distribution and protein expression levels of AhR within these cell lines. Alterations in reactive oxygen species (ROS) levels and mitochondrial membrane potential (MMP) were evaluated using DCFH-DA dye and the JC-1 assay, respectively. Furthermore, we investigated changes in the expression levels of Nrf2, Cleaved-Caspase 3, Cleaved-Caspase 8, Bcl-2, and Bax through Western blot analysis. Our findings indicate that PCB118 and the AhR-specific agonist CAY10465 diminish the viability of GC-1 and GC-2 cells, facilitate the nuclear translocation and expression of AhR protein, elevate ROS levels, and reduce MMP. Moreover, these agents markedly increase the levels of Cleaved-Caspase 3 and Cleaved-Caspase 8 while decreasing the Bax/Bcl-2 ratio. Notably, the AhR antagonist CH223191 and resveratrol have the capacity to restore the functionality of GC-1 and GC-2 cells by mitigating the effects of PCB118 and CAY10465. Based on these observations, we propose that exogenous AhR ligands PCB118 and CAY10465 promote the nuclear translocation and upregulation of AhR expression in GC-1 and GC-2 cells. This process subsequently induces mitochondrial oxidative stress, wich activates the apoptotic signaling pathway and ultimately compromises cellular viability.