Embryonic exposure to GenX causes reproductive toxicity by disrupting the formation of the blood-testis barrier in mouse offspring

As a replacement for perfluorooctanoic acid, hexafluoropropylene oxide dimer acid, commercially referred to as “GenX”, has attracted significant attention. However, a comprehensive understanding of the reproductive systems of male offspring exposed to GenX is lacking. This study aimed to investigate how embryonic exposure to GenX affects the reproductive development of male offspring and the underlying mechanisms. We administered GenX daily via gavage (2 mg/kg body weight/day) to the mice from day 12.5 of pregnancy until delivery. Our results suggested that embryonic exposure to GenX led to delayed onset of puberty in male offspring, with destruction of the testicular structure, disruption of the blood-testis barrier, decreased serum testosterone levels, decreased sperm count, impaired sperm motility, and increased rates of sperm abnormalities. We investigated the mechanism of blood-testis barrier breakdown in vitro by treating Sertoli cells (TM4) with GenX. GenX exposure caused the accumulation of senescent TM4 cells, decreased their glutathione (GSH) levels, and increased their oxidized glutathione levels. GenX inhibited glutaminase activity in TM4 cells, leading to decreased GSH synthesis, increased intracellular oxidative stress, and subsequent TM4 cell senescence, ultimately compromising the blood-testis barrier. Our findings indicated that embryonic exposure to GenX may cause Sertoli cell senescence by altering glutamine metabolism, disrupting the blood-testis barrier, and resulting in abnormal reproductive development in male offspring.