Phenanthrene exposure disrupts puberty onset in SD rats by influencing hypothalamic neural networks

Polycyclic aromatic hydrocarbons (PAHs) are gaining attention due to their widespread occurrence and serious health risk. Epidemiological survey research discovered that PAHs are associated with compromised pubertal development. To investigate this, weaned rats were administrated to corn oil (control group) or phenanthrene (PHE) for 21 days. Female and male rats treated with PHE exhibited similar puberty delay characteristics. PHE caused considerable follicular decline in female rats, despite having comparable levels of serum follicle-stimulating hormone and luteinizing hormone to the controls. Similarly, PHE male rats also revealed impairment of spermatocyte maturation with a slight decrease in hormone secretion. Neuropeptide pathways of puberty was impaired as indicated by decreased KISS1, GPR54, and TAC3 transcript and protein expression levels. These findings were later backed up by the demonstration of similar phenotypes in GT1-7 cells exposed with PHE after 48h. Importantly, transcriptome analysis revealed that PHE exposure dramatically changed the neuroactive ligand-receptor interaction route in females and the immune pathway in males. Our findings shed light on the effects of PHE on puberty development and reveal a potential mechanism for PHE-induced puberty delay.