VCOM Research Day Program Book 2023

Medical Student Research Biomedical

13 The Effect of Quaternary Ammonium Compound Disinfectants (QACs) on Placental Growth Factor (PLGF) and Vascular Endothelial Groth Factor (VEGF) Expression in Mouse Placenta

Hannah L Paros; Sarah E Payne; Terry C Hrubec Corresponding author: hparos@vt.vcom.edu

Edward Via College of Osteopathic Medicine-Virginia Campus

Quaternary Ammonium Compounds (QAC) are used as an active ingredient in numerous household cleaning products such as surface disinfectants and detergents. Two of the most common QACs are Alkyl Dimethylbenzyl Ammonium Chloride and Didecyl Dimethyl Ammonium Chloride (ADBAC + DDAC). Given the COVID-19 pandemic, there has been a global increase in disinfection practices which likely correlates to an increase in chronic, low level QAC exposure to humans. Despite common use of QACs in disinfectant products, little is known about their safety. Recent studies demonstrated that exposure to QACs can have detrimental effects on fetal growth and reproductive health by altering cytokine production in the placenta and affecting fetal-placental ratio. Additionally, QAC exposure has been shown to alter immune function and increase inflammatory cytokine production, both of which can affect placental function and fetal growth. There continues to be a need to further research the effects of QACs on maternal fetal interactions given the negative effects on human health demonstrated thus far.

This study aims to assess how exposure of QACs to pregnant female mice affects growth of the placenta by examining distribution of two growth factors. Vascular endothelial growth factor (VEGF) expression is essential to angiogenesis in both the placenta and developing fetus. Placental growth factor (PLGF) is produced by the placenta in utero and contributes to placental development as well as angiogenesis and vasculogenesis in the fetus. Therefore, exposure to a toxin such as QACs has the potential to disrupt the expression and distribution of these growth factors in the placenta which could affect fetal development. We hypothesize that there will be decreased expression of VEGF and PLGF antibodies in the QAC-exposed placenta due to the toxic effects of these chemicals. To identify changes in the expression and distribution of VEGF and PLGF in the placentas of control and QAC-exposed mice, we will use immunohistochemistry to visualize distribution of these growth factors. Control unexposed mice were bred and carried to gestational day 17 in a QAC-free environment. For the exposed group, clean mice

were transferred to a facility using ADBAC+DDAC disinfectants and received ambient exposure to normal use of the disinfectant in the mouse room for 2 weeks and throughout breeding/gestation. Pregnant dams were euthanized on day 17 and placentas/fetuses were collected and weighed. Placentas were flash frozen, embedded with OTC, and 30 um cryosections were cut. Cryosections were fixed in a 1:1 solution of methanol-acetone followed by immunohistochemistry with VEGF and PLGF antibodies. Expression of growth factors was visualized using DAB substrate (3,3’-diaminobenzidine). Preliminary control slides reveal differential staining between the junctional zone and labyrinth. This project was funded through the VCOM One Health Seed Grant.

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