Toxicological Effects of BPDE on Dysfunctions of Female Trophoblast Cells

Gestational exposure to 1-NP induces ferroptosis in placental trophoblasts via CYP1B1/ERK signaling pathway leading to fetal growth restriction

Fetal growth restriction (FGR) is a prevalent complication in obstetrics, yet its exact aetiology remains unknown. Numerous studies suggest that the degradation of the living environment is a significant risk factor for FGR. 1-Nitropyrene (1-NP) is a widespread environmental pollutant as a representative substance of nitro-polycyclic aromatic hydrocarbons. In this study, we revealed that 1-NP induced FGR in fetal mice by constructing 1-NP exposed pregnant mice models. Intriguingly, we found that placental trophoblasts of 1-NP exposed mice exhibited significant ferroptosis, which was similarly detected in placental trophoblasts from human FGR patients. In this regard, we established a 1-NP exposed cell model in vitro using two human trophoblast cell lines, HTR8/SVneo and JEG-3. We found that 1-NP not only impaired the proliferation, migration, invasion and angiogenesis of trophoblasts, but also induced severe cellular ferroptosis. Meanwhile, the ferroptosis inhibitor ferrostatin-1 (Fer-1) effectively rescued 1-NP-induced trophoblast biological function impairment. Mechanistically, we revealed that 1-NP regulated ferroptosis by activating the ERK signaling pathway. Moreover, we innovatively revealed that CYP1B1 was essential for the activation of ERK signaling pathway induced by 1-NP. Overall, our study innovatively identified ferroptosis as a significant contributor to 1-NP induced trophoblastic functional impairment leading to FGR and clarified the specific mechanism by which 1-NP induced ferroptosis via the CYP1B1/ERK signaling pathway. Our study provided novel insights into the aetiology of FGR and revealed new mechanisms of reproductive toxicity of environmental pollutants.

Potential pathway and mechanisms underlining the immunotoxicity of benzo[a]pyrene to Chlamys farreri

The long-distance migration of polycyclic aromatic hydrocarbons (PAHs) promotes their release into the marine environment, posing a serious threat to marine life. Studies have shown that PAHs have significant immunotoxicity effects on bivalves, but the exact mechanism of immunotoxicity remains unclear. This paper aims to investigate the effects of exposure to 0.4, 2, and 10 μg/L of benzo(a)pyrene (B[a]P) on the immunity of Chlamys farreri under environmental conditions, as well as the potential molecular mechanism. Multiple biomarkers, including phagocytosis rate, metabolites, neurotoxicity, oxidative stress, DNA damage, and apoptosis, were adopted to assess these effects. After exposure to 0.4, 2, and 10 μg/L B[a]P, obvious concentration-dependent immunotoxicity was observed, indicated by a decrease in the hemocyte index (total hemocyte count, phagocytosis rate, antibacterial and bacteriolytic activity). Analysis of the detoxification metabolic system in C. farreri revealed that B[a]P produced B[a]P-7,8-diol-9,10-epoxide (BPDE) through metabolism, which led to an increase in the expression of protein tyrosine kinase (PTK). In addition, the increased content of neurotransmitters (including acetylcholine, γ -aminobutyric acid, enkephalin, norepinephrine, dopamine, and serotonin) and related receptors implied that B[a]P might affect immunity through neuroendocrine system. The changes in signal pathway factors involved in immune regulation indicated that B[a]P interfered with Ca2+ and cAMP signal transduction via the BPDE-PTK pathway or neuroendocrine pathway, resulting in immunosuppression. Additionally, B[a]P induced the increase in reactive oxygen species (ROS) content and DNA damage, as well as an upregulation of key genes in the mitochondrial pathway and death receptor pathway, leading to the increase of apoptosis rate. Taken together, this study comprehensively investigated the detoxification metabolic system, neuroendocrine system, and cell apoptosis to explore the toxic mechanism of bivalves under B[a]P stress.

Associations between urinary monohydroxylated polycyclic aromatic hydrocarbons and unexplained recurrent spontaneous abortion and health risk assessment in a large case-control study in China

Polycyclic aromatic hydrocarbons (PAHs) are a group of environmental endocrine disruptors with known carcinogenic, reproductive, and developmental toxicity. Important knowledge gaps remain regarding the relationship between PAH exposure and unexplained recurrent spontaneous abortion (URSA). In the present study, twelve monohydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) were measured in the urine of 413 URSA cases and 434 controls. The main OH-PAHs measured in this study were monohydroxy metabolites of naphthalene, followed by fluorene and phenanthrene. After the creatinine correction, the median concentration of urinary OH-PAHs in the control group (17.4 μg/g Creatinine) was higher than that in the case group (14.2 μg/g Creatinine). There was no positive relationship between PAH exposure and URSA using binary logistic regression analysis. Among 847 Chinese women of childbearing age, residential environment, type of drinking water, and education level were the influencing factors of PAH exposure. The health risk assessment showed that over 98% of women had a carcinogenic risk with carcinogenic risk values above the acceptable level (10^-6). Although this large-scale case-control study did not observe an association between PAH exposure and URSA, more attention should be paid to the high carcinogenic risk due to PAH exposure in women of reproductive age.

Antioxidant, antiproliferative, and apoptotic activity of thymoquinone against benzo(a)pyrene-induced experimental lung cancer

Several studies have suggested that increased consumption of phytochemicals is a comparatively easy and practical strategy to significantly decrease the incidence of cancer. In the present study, we have reported the protective effect of a natural compound, thymoquinone (TQ) against benzo(a)pyrene (B(a)P)-induced lung carcinogenesis in Swiss albino mice. B(a)P (50 mg/kg body weight) was administered twice weekly for four successive weeks and left until 20 weeks to induce lung cancer in mice. TQ (20 mg/kg body weight) was given orally as a pretreatment and posttreatment drug to determine its chemopreventive and therapeutic effects. B(a)P-induced lung cancer-bearing animals displayed cachexia-like symptoms along with an abnormal increase in lung weight and the activities of marker enzymes adenosine deaminase, aryl hydrocarbon hydroxylase, gamma-glutamyl transpeptidase, 5'-nucleotidase and lactate dehydrogenase; tumor marker carcinoembryonic antigen levels. Furthermore, B(a)P-induced animals showed elevated levels of lipid peroxides with subsequent depletion in the antioxidant status and histological aberrations. These anomalies were accompanied by increased expressions of proliferating cell nuclear antigen and cyclin D1 in the lung sections derived from B(a)P-induced animals. On TQ treatment, all the above alterations were returned to near normalcy. Furthermore, TQ administration in B(a)P-induced animals downregulated phosphatidylinositol 3-kinase/protein kinase B signaling pathway and induced apoptosis as evidenced by a decrease in cytochrome c, proapoptotic Bax, caspase-3, and p53 with a parallel increase in antiapoptotic Bcl-2. Our present results demonstrate the potential effectiveness of TQ as an antioxidant, antiproliferative, and apoptotic agent against B(a)P-induced experimental lung tumorigenesis.

Seasonality of Hypoplastic Left Heart Syndrome and Single Ventricle Heart in Poland in the Context of Air Pollution

Hypoplastic left heart syndrome (HLHS) and single ventricle (SV) remain a significant cause of cardiac deaths occurring in the first week of life. Their pathogenesis and seasonal frequency are still unknown. Therefore, we attempt to look at the genesis of the HLHS and SV in the context of territorial distribution as well as seasonality. A total of 193 fetuses diagnosed with HLHS and 92 with SV were selected. The frequency was analyzed depending on the year, calendar month, quarter and season (fall-winter vs. spring-summer). The spatial distribution of HLHS and SV in Poland was analyzed. We observed a statistically significant overrepresentation of HLHS formation frequency in March: 27 (14.00%) in comparison to a monthly median of 15 (IQR: 13.75-16.25; p = 0.039), as well as a significantly higher frequency of HLHS in 2007-2009: 65 cases (33.68%) in comparison to the annual mean of 13.79 ± 6.36 (p < 0.001). We noted a higher frequency of SV among parous with the last menstrual period reported in the fall/winter season of 58 vs. 34 in the spring/summer season (p = 0.014). The performed analysis also revealed significant SV overrepresentation in 2008: 11 cases (12.00%) in comparison to the annual mean of 6.57 ± 2.71 (p = 0.016). Every single case of HLHS was observed when the concentration of benzo(a)pyrene and/or PM10 exceeded the acceptable/target level. Our research indicates that both the season and the level of pollution are significant factors affecting the health of parous women and their offspring. The reason why HLHS and SV develop more frequently at certain times of the year remains unclear, therefore research on this topic should be continued, as well as on the effects of PM10 and benzo(a)pyrene exposure.