Effect of PM2.5 exposure on gestational hypertension, fetal size in preeclampsia-like rats

Gao, Jie; Luo, Mei; Zhao, Shuo; Wang, Hailing; Li, Xuan; Xu, Pili; Ma, Wei; Liu, Chongdong

Effect of PM2.5 exposure on gestational hypertension, fetal size in preeclampsia-like rats

2022

Studies have shown intriguing associations between gestational PM₂.₅ exposure and preeclampsia (PE), as well as fetal growth restriction (FGR). This study investigated the impact of PM₂.₅ exposure on gestational hypertension and fetal outcome in a preeclampsia-like rat model. Pregnant Sprague Dawley rats were exposed to either filtered (FA) or PM₂.₅-contaminated air during the whole pregnancy period. A PE-like rat model was established by intraperitoneal injection of L-NAME (300 mg/kg) from gestational day (GD) 12 to until GD20. Systolic blood pressure (SBP), weight gain, pup weight and placental weight were measured. The percentages of rat Treg/Th17 cells and Th17-related cytokines were examined by flow cytometry. Gene expression profiles were analyzed by microarray, and the expression of differentially expressed genes was validated by qRT-PCR. The results showed that maternal PM₂.₅ exposure had no effect on SBP but was associated with low birth weight (LBW) and a higher labyrinth/basal zone ratio. The percentages of splenic Th17 cells from the PM₂.₅ group of PE-like rats were higher than those from the FA or PM₂.₅ groups of healthy controls. A significantly decreased Treg/Th17 cell ratio was found in the PM₂.₅ group of PE-like rats. The mRNA expression of Foxp3 was downregulated, while the mRNA expression of RORα and RORγτ was upregulated after PM₂.₅ exposure. Furthermore, we observed that both the mRNA and protein levels of TNF-a, CCL2, CCL3 and CCR1 increased in the PM₂.₅ groups. Our study suggested that systemic inflammation may contribute to the development of FGR associated with PM₂.₅ exposure throughout pregnancy.

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