Exposure to Propylparaben During Pregnancy and Lactation Induces Long-Term Alterations to the Mammary Gland in Mice.

Publication Type Academic Article
Authors Mogus J, LaPlante C, Bansal R, Matouskova K, Schneider B, Daniele E, Silva S, Hagen M, Dunphy K, Jerry D, Schneider S, Vandenberg L
Journal Endocrinology
Volume 162
Issue 6
Date Published 06/01/2021
ISSN 1945-7170
Keywords Lactation, Mammary Glands, Animal, Parabens, Prenatal Exposure Delayed Effects
Abstract The mammary gland is a hormone sensitive organ that is susceptible to endocrine-disrupting chemicals (EDCs) during the vulnerable periods of parous reorganization (ie, pregnancy, lactation, and involution). Pregnancy is believed to have long-term protective effects against breast cancer development; however, it is unknown if EDCs can alter this effect. We examined the long-term effects of propylparaben, a common preservative used in personal care products and foods, with estrogenic properties, on the parous mouse mammary gland. Pregnant BALB/c mice were treated with 0, 20, 100, or 10 000 µg/kg/day propylparaben throughout pregnancy and lactation. Unexposed nulliparous females were also evaluated. Five weeks post-involution, mammary glands were collected and assessed for changes in histomorphology, hormone receptor expression, immune cell number, and gene expression. For several parameters of mammary gland morphology, propylparaben reduced the effects of parity. Propylparaben also increased proliferation, but not stem cell number, and induced modest alterations to expression of ERα-mediated genes. Finally, propylparaben altered the effect of parity on the number of several immune cell types in the mammary gland. These results suggest that propylparaben, at levels relevant to human exposure, can interfere with the effects of parity on the mouse mammary gland and induce long-term alterations to mammary gland structure. Future studies should address if propylparaben exposures negate the protective effects of pregnancy on mammary cancer development.
DOI 10.1210/endocr/bqab041
PubMed ID 33724348
PubMed Central ID PMC8121128
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