Particulate Matter Exposure During Oocyte Maturation: Cell Cycle Arrest, ROS Generation, and Early Apoptosis in Mice

Abstract

Particulate matter (PM) is a general atmospheric pollutant released into the air by an anthropogenic and naturally derived mixture of substances. Current studies indicate that fine dust can result in different health defects, including endothelial dysfunction, asthma, lung cancer, cardiovascular diseases, uterine leiomyoma, deterioration in sperm quality, and overall birth impairment. However, the most prominent effects of PM10 (diameter < 10 μM) exposure on the female reproductive system, especially with respect to oocyte maturation, remain unclear. In the present study, maturing mouse oocytes were treated with PM10 and the phenotypes of the resulting toxic effects were investigated. Exposure to PM10 led to impairment of maturation capacity by inducing cell cycle arrest and blocking normal polar body extrusion during in vitro maturation and activation of fertilization of mouse oocytes. Additionally, defects in tubulin formation and DNA alignment were observed in PM10-treated oocytes during metaphase I to anaphase/telophase I transition. Moreover, PM10 induced reactive oxygen species generation, mitochondrial dysfunction, DNA damage, and early apoptosis. Taken together, these results indicate that PM10 exposure leads to a decline in oocyte quality and affects the subsequent embryonic development potential of mammalian oocytes.

Adverse PFAS effects on mouse oocyte in vitro maturation are associated with carbon‐chain length and inclusion of a sulfonate group

“…However, as the carbon‐chain length increased to eight, PFOS treatment resulted in a lower GVBD rate (32.84 ± 7.21% vs. 76.03 ± 1.11% in the control, p < 0.001, Figure 1B,C) and a lower PBE rate (24.93 ± 8.14%, compared to 73.84 ± 1.78% in the control, p < 0.001, Figure 1B,D). Interestingly, we noticed that although PFHxS‐treated oocytes had normal GVBD and PBE rates, like PFOS, some oocytes extruded a large PB (Figure 1B), a phenotype that has been qualitatively described in previous PFAS studies 17,19,32 . Therefore, we calculated the average size ratio between the first PB and its oocyte for each treatment, as described in Section 2.5.…”

“…Various epigenetic regulations are known to be involved in oocyte maturation, including histone acetylation, phosphorylation, and SUMOylation. 15 The breakdown of nuclear envelop, GVBD, exposes the chromosomes to many environmental toxicants, such as iodoacetic acid, 16 PM 10 17 and several PFAS chemicals. 18 , 19 , 20 , 21 Iodoacetic acid, for example, has been shown to induce DNA damage and cause chromosome misalignment at the metaphase I stage.…”

Adverse PFAS effects on mouse oocyte in vitro maturation are associated with carbon-chain length and inclusion of a sulfonate group

“…1B), a phenotype that has been qualitatively described in previous PFAS studies. 19,32,33 Therefore, we calculated the average size ratio between the first PB and its oocyte for each treatment, as described in section 2.5. We found the average size ratio was 14.24 % in the control; in contrast, the ratios were 31.22 % in 600 µM PFHxS group and 52.57 % in the PFOS group, respectively (P < 0.001, Fig.…”

“…Similar pathways have been reported to induce oxidative stress like polychlorinated biphenyl (PCB). 67,68 Excess ROS can cause many problems in oocytes, especially after GVBD, including DNA damage 17,20 and early apoptosis (Supplemental Fig. 2).…”

“…Various epigenetic regulations are known to be involved in oocyte maturation, including histone acetylation, phosphorylation, and SUMOylation. 15 GVBD, the breakdown of nuclear envelop, exposes the chromosomes to many environmental toxicants, such as iodoacetic acid (IAA) 16 , PM 17 and several PFAS chemicals 18–21 . IAA, for example, has been shown to induce DNA damage and cause chromosome misalignment at the metaphase I stage.…”