BioProject

The herbicide linuron is an endocrine disruptor with a suspected anti-androgenic mode of action (MOA) but the complete MOA for LIN is not fully characterized. More...

The herbicide linuron is an endocrine disruptor with a suspected anti-androgenic mode of action (MOA) but the complete MOA for LIN is not fully characterized. The objectives of this study were to better characterize the MOA of LIN in the fathead minnow (FHMs) ovary by comparing expression profiles of LIN to dihydrotestosterone (DHT) and flutamide (FLUT), both model compounds with well defined androgenic and anti-androgenic MOAs respectively. Ovarian explants from vitellogenic FHMs were exposed to 10-6 M, 10-7 M, and 10-8 M of DHT, FLUT, and LIN in vitro in a12 hour incubation experiment. Ovary explants exposed to DHT showed a significant increase in E2 production compared to controls but FLUT and LIN did not affect E2 production. Microarray analysis and support vector machine classification revealed that expression patterns of FLUT and LIN in the ovary were more similar to each other compared to DHT and other androgens. Gene set enrichment analysis identified the notch signaling cascade was affected by all three chemicals. DHT down-regulated the WNT-Frizzled pathway while LIN down-regulated angiopoietin receptor signaling and increased biosynthesis of cholesterol. LIN shared 27 expression sub-networks (e.g. beta-3 adrenergic receptor, MAP3K1, interleukin, signlaing) in common with FLUT, and only 4 sub-networks with DHT. A reciprocal gene expression network was constructed using DHT and FLUT data, and the network revealed that steroid metabolism, translation, and DNA replication are potentially regulated through AR signaling. This study characterizes cell pathways associated with E2 production and identifies cell signaling cascades that may be disrupted by ureic-based herbicides in the ovary. Overall design: 16 samples total; 4 control, 4 DHT, 4 Flutamide, 4 LIN Less...