Effects of endocrine disrupting chemicals (EDCs) on ovarian gene expression after prenatal and lactational exposure to NeuroMix (NMX)

• Grant number: 25/17308-5
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)
• Start date: February 01, 2026
• End date: January 31, 2027
• Field of knowledge: Biological Sciences - Pharmacology - Toxicology
• Principal Investigator: Arielle Cristina Arena
• Grantee: Lívia Trippe Nagaoka Gonçalves
• Supervisor: Andrea Gore
• Host Institution: Instituto de Biociências (IBB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil
• Institution abroad: University of Texas at Austin (UT), United States
• Associated to the scholarship: 24/04466-9 - Exposure of the parental generation to Nitrosodimethylamine (NDMA): multigenerational assessment of toxicological and reproductive parameters of the F0 and F2 generations in male and female rats., BP.DD

Abstract

Normal ovarian development and function are regulated by endogenous and exogenous factors that, if perturbed, may cause structural and functional changes that impair reproduction. Among these environmental factors are endocrine-disrupting chemicals (EDCs) that can mimic or block endogenous hormonal processes and thus disrupt the normal functioning of this complex tissue. This is especially concerning during critical periods of development, like the gestational and lactational periods, in which the perturbation of hormonal processes affects not only the individual, but also their offspring through actions on gene expression in the developing ovary. In this study, we hypothesize that gestational and lactational exposure to NeuroMix (NMX) alters ovarian gene expression across different cell populations, thereby disrupting the normal development of reproductive function. The aim of this study is to assess how prenatal and early-life indirect exposure to NeuroMix (NMX), a low-dose mixture of environmentally relevant EDCs, can impair cell-type specific transcriptional mechanisms in the ovary through single-cell RNA sequencing (scRNASeq) with a bioinformatics approach to data analysis. For this, adult Sprague-Dawley female rats (n = 12/group) will be mated and randomly assigned to experimental groups: control group, which will receive the vehicle (¼ 'Nilla wafer containing 0.06% DMSO and 0.0037% ethanol in sesame oil), and the NeuroMix (NMX) group, which will receive 100 ¿l of NMX. The groups will be exposed throughout the gestation (E8-E18) and lactation (P1-P21). Ovarian tissues of the offspring will be collected at two time points: on P1, after culling, and on the first estrus (approximately P35-P40), following vaginal opening. At the end of the respective exposure periods, the animals will be euthanized by rapid decapitation, and their ovaries will be frozen on dry ice and stored at -80 °C for RNA extraction. The ovaries will be processed for single-cell RNA sequencing through nuclei isolation following the 10x Genomics protocol, with library preparation and sequencing performed at the UT Austin Genomics Core. Downstream analysis of obtained data will be done using Cell Ranger, Seurat, and other publicly available bioinformatics tools. These findings will provide insight into how environmental exposures shape ovarian development at the single-cell level, with implications for reproductive health across generations. (AU)