Atrazine disorganises laminin formation and reduces testis cell number in tammar testes during early differentiation

Reproduction. 2024 Jun 1:REP-23-0504. doi: 10.1530/REP-23-0504. Online ahead of print.

Abstract

The herbicide atrazine was banned in Europe in 2003 due to its endocrine disrupting activity but remains widely used. The integrity of the laminin structure in fetal testis cords requires oestrogen signalling but over-exposure to xenoestrogens in the adult can cause testicular dysgenesis. However, whether xenoestrogens affect laminin formation in developing testes has not been investigated. Here we examined the effects of atrazine in the marsupial tammar wallaby during early development and compare it with the effects of the anti-androgen flutamide, oestrogen and the oestrogen degrader fulvestrant. The tammar, like all marsupials, gives birth to altricial young, allowing direct treatment of the developing young during the male programming window (day 20-40 post-partum (pp)). Male pouch young were treated orally with atrazine (5 mg/kg), flutamide (10 mg/kg), 17β-oestradiol (2.5 mg/kg) and fulvestrant (1 mg/kg) daily from day 20 to 40 pp. Distribution of laminin, vimentin, SOX9 and DDX4, cell proliferation and mRNA expression of SRY, SOX9, AMH and SF1 were examined in testes at day 50 post-partum after the treatment. Direct exposure to atrazine, flutamide, 17β-oestradiol and fulvestrant all disorganised laminin but had no effect on vimentin distribution in testes. Atrazine reduced the number of germ cells and Sertoli cells when examined at day 40-50 pp and day 20-40 pp, respectively. Both flutamide and fulvestrant reduced the number of germ cells and Sertoli cells. Atrazine also downregulated SRY expression and impaired SOX9 nuclear translocation. Our results demonstrate that atrazine can compromise normal testicular differentiation during the critical male programming window.