Structural and proteomic evaluation of the placenta of rats subjected to exposure to phthalates and nanoplastics: in vivo, in silico and in vitro approaches.

• Grant number: 24/21689-1
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: May 01, 2025
• End date: February 28, 2029
• Field of knowledge: Biological Sciences - Morphology - Embryology
• Principal Investigator: Wellerson Rodrigo Scarano
• Grantee: Natália Magosso
• Host Institution: Instituto de Biociências (IBB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil
• Associated research grant: 22/12304-3 - Repercussions of maternal exposure to nanoplastics and phthalates: maternal aspects and susceptibility to prostatic oncogenesis in rats, AP.R

Abstract

The increasing production and pollution of plastics increases human exposure to environmental contaminants, micro/nanoplastics (MNPs) and their additives. Due to their size, MNPs can cross barriers such as the placenta and have been found in different human and murine organs. These substances adsorb other pollutants, such as phthalates, which are plasticizers and act as endocrine disruptors (EDs). The placenta is an essential maternal-fetal organ for fetal development, and its function may be compromised by exposure to these contaminants, triggering direct and long-term consequences in the offspring. In a previous study by the student, changes in the placenta at the level of gene expression of targets related to growth factors were observed. Thus, the objective of this work will be to evaluate the effects of gestational exposure to polystyrene nanoparticles (NPs) and a phthalates mixture (PM) on the ultrastructure of placental cells, identify the profile of proteins expressed in the placenta and perform in silico analyses. Additionally, in vitro exposure tests will be performed to validate targets of interest. For this purpose, pregnant SD rats will be distributed into 6 groups: CTR: (control; vehicle); T1: 20µg/kg/day of PM; T2: 200mg/kg/day PM; T3: 1mg/kg/day of 100nm NPs; T4: 20µg/kg/day PM + 1mg/kg/day 100nm NPs; T5: 200mg/kg/day PM + 1mg/kg/day 100nm NPs. Treatment will be administered orally from gestational day 5 (GD5) to GD20. On DG20, 6-8 rats from each group will be anesthetized and submitted to laparotomy, the fetuses will be isolated and fragments of their placentas will be sent for ultrastructural analysis, through transmission electron microscopy and for proteomic analysis. The differentially expressed proteins will be analyzed according to their protein-protein interaction obtained through the String platform and enrichment analyses will be performed on the KOBAS platform. Finally, in order to validate proteins found in the in vivo study, human placental 3A (tPA-30-1) cells will be exposed to NPs and MFs (phthalate monoesters) and mechanistic assays will be performed, using mimics or inhibitors for the pathways of interest.