Effects of intrauterine exposure to benzophenone-3 in lactating murine mammary gland

SCHIERANO-MAROTTI G; ALTAMIRANO GA; GOMEZ AL; MUÑOZ-DE-TORO M; KASS L

Congreso; Reunión Conjunta SAIC, SAI, AAFE, NANOMED.ar; 2021

Benzophenone-3(BP3), an ultraviolet radiation filter commonly used in sunscreens, has been shownto alter mammary gland (MG) development. Previously, we have demonstrated thatexposure to BP3 alters beta-casein (CSN2) and alpha-lactalbumin (LALBA) milkprotein expression during functional differentiation of the MG in vitro.Here, our aim was to evaluate whether intrauterine exposure to BP3 alters the lactatingmammary gland in the F1 female offspring. Pregnant F0 C57BL/6 mice weredermally exposed to vehicle (sesame oil; Control), 0.15 (0.15BP3) or 50mg BP3/kg/day(50BP3) from gestation day 8.5 to 18. At 8 weeks-old, female offspring (F1)were bred and MG samples were obtained on lactation day 10. The proteinexpression of the myoepithelial cell biomarker alpha-smooth muscle actin, CSN2and LALBA was assessed by immunohistochemistry. The perimeter and area of the alveoliand the myoepithelial linear density were measured to establish either the proportionof large/small alveoli per group or the maturation and differentiation of themyoepithelial cells. CSN2, LALBA and wheyacidic protein (WAP) mRNA expression was evaluated by qRT-PCR. The alveolarperimeter in 0.15BP3 animals was the lowest among groups (p<0.05). Conversely,50BP3 animals showed the highest alveolar area compared to 0.15BP3 ones(p<0.05). In addition, BP3 treatments had opposite effects on the proportionof large/small alveoli: whereas it was similar in control animals (47.3/52.7), itwas diminished in the 0.15BP3 group (31.7/68.2) and augmented in the 50BP3 group(60.7/39.2). Also, the myoepithelial linear density was lower in 0.15BP3 than incontrol animals (p<0.05). In contrast, the protein expression of CSN2 andLALBA, and the mRNA expression of CSN2, LALBA and WAP were similar betweengroups (p>0.05). In conclusion, the intrauterine exposure to BP3 altered thelactating MG, and these effects could be related to the alveolar secretory contentand/or its contractile function.