Ferroptosis participates in dibutyl phthalate-aggravated allergic asthma in ovalbumin-sensitized mice

Dibutyl phthalate (DBP), used as a plasticizer, is of wide concern as an environmental pollutant since it has certain immunotoxicity. Although there is growing evidence supporting a link between DBP exposure and allergic airway inflammation, there is less information concerned with whether the ferroptosis pathway is involved in DBP-aggravated allergic asthma in ovalbumin (OVA)-sensitized mice. This study aimed to investigate the role and underlying mechanisms of ferroptosis in DBP-exposed allergic asthmatic mice. Balb/c mice were orally exposed to 40 mg/kg^-1 DBP for 28 days, followed by sensitization with OVA and seven consecutive challenges with nebulized OVA. We analyzed airway hyperresponsiveness (AHR), immunoglobulins, inflammation and pulmonary histopathology, to investigate whether DBP exacerbates allergic asthma in OVA-induced mice. We also measured the biomarkers of ferroptosis (Fe²⁺, GPX4, PTGS2), proteins related to the ferroptosis pathway (VEGF, IL-33, HMGB1, SLC7A11, ALOX15, PEBP1), and indices of lipid peroxidation (ROS, Lipid ROS, GSH, MDA, 4-HNE), to explore the role of ferroptosis in DBP+OVA mice. Finally, we used ferrostatin-1 (Fer-1) as an antagonist against the harmful effects of DBP. The results showed that, DBP+OVA mice had a significant increase in AHR, airway wall remodeling and airway inflammation. Further, we showed that DBP aggravated allergic asthma via ferroptosis and lipid peroxidation, and that Fer-1 inhibited ferroptosis and alleviated the pulmonary toxicity of DBP. These results suggest that ferroptosis participates in the exacerbation of allergic asthma resulting from oral exposure to DBP, highlighting a novel pathway for the connection between DBP and allergic asthma.

Apoptotic susceptibility of pancreatic alpha cells to environmentally relevant dose levels of bisphenol-A versus dibutyl phthalate is mediated by HSP60/caspase-3 expression in male albino rats

Unfortunately, humanity is exposed to mixed plasticizers such as bisphenol-A (BPA) and dibutyl phthalate (DBP) that are leached from the daily used plastic products. Previous studies have demonstrated their potential in pancreatic beta cell injury and diabetes induction. The study hypothesized that both compounds would affect the pancreatic alpha cells in albino rats when administered at environmentally relevant doses. Heat shock protein 60 (HSP60) and caspase-3 protein expression was also investigated as potential mechanisms. Thirty-six male Wistar albino rats were separated into four equal groups: control, BPA alone, DBP alone, and BPA + DBP combined groups. BPA and DBP were given in drinking water for 45 days in a dose of 4.5 and 0.8 µg/L, respectively. Fasting blood glucose, serum insulin, pancreatic tissue levels of malondialdehyde, and superoxide dismutase were measured. Pancreatic sections were subjected to hematoxylin & eosin (H & E) staining, glucagon, HSP60, and caspase-3 immunohistochemistry. Although all three experimental groups showed diffuse islet cell HSP60 immunoreactivity, rats exposed to BPA alone showed α-cell-only apoptosis, indicated by H & E changes and caspase-3 immunoreactivity, associated with reduced glucagon immunoreaction. However, rats exposed to DBP alone showed no changes in either α or β-cells. Both combined-exposed animals displayed α and β apoptotic changes associated with islet atrophy and reduced glucagon expression. In conclusion, the study suggested HSP60/caspase-3 interaction, caspase-3 activation, and initiation of apoptosis in α-cell only for BPA-alone exposure group, meanwhile DBP alone did not progress to apoptosis. Interestingly, both α/β cell effect was observed in the mixed group implying synergetic/additive action of both chemicals when combined.

Mono-n-butyl phthalate regulates nuclear factor erythroid 2-related factor 2 and nuclear factor kappa B pathway in an ovalbumin-induced asthma mouse model

Recent studies have emphasized the role of endocrine-disrupting chemicals in asthma development, especially in eosinophilic asthma. However, the exact mechanism was unknown. Among all the endocrine-disrupting chemicals, mono-n-butyl phthalate (MnBP) was a chemical that was most frequently detected in human urine. Our study was performed with the aim of investigating the harmful effects of MnBP on airway epithelial cells (AECs), T cells, and eosinophils by using eosinophilic asthma mouse models. Mice that received OVA with MnBP had higher levels of airway hyperresponsiveness, total and eosinophil cell counts, as well as T cell proliferation and T helper 2 cytokine release than those which only received OVA. Moreover, MnBP contributed to directly enhancing the eosinophilic activation which was shown in. Long-term exposure MnBP activated AECs through the nuclear factor kappa B (NF-kB) pathway, decreased nuclear factor erythroid 2-related factor 2 (Nrf2) expression, and increased interleukin-33 expression. Additionally, MnBP can induce human eosinophil activation to release eosinophil extracellular traps (EETs). Taken together, our study suggested the roles of MnBP exposure increase the risk of asthma development and severity. Furthermore, vitamin E treatment (anti-inflammatory and antioxidant effects) can reduce MnBP-induced harmful effects through inhibiting EETs, restoring Nrf2, and suppressing the NF-kB pathway.

Associations between prenatal maternal urinary concentrations of personal care product chemical biomarkers and childhood respiratory and allergic outcomes in the CHAMACOS study

BACKGROUND

Personal care product chemicals may be contributing to risk for asthma and other atopic illnesses. The existing literature is conflicting, and many studies do not control for multiple chemical exposures.

METHODS

We quantified concentrations of three phthalate metabolites, three parabens, and four other phenols in urine collected twice during pregnancy from 392 women. We measured T helper 1 (Th1) and T helper 2 (Th2) cells in their children's blood at ages two, five, and seven, and assessed probable asthma, aeroallergies, eczema, and lung function at age seven. We conducted linear and logistic regressions, controlling for additional biomarkers measured in this population as selected by Bayesian Model Averaging.

RESULTS

The majority of comparisons showed null associations. Mono-n-butyl phthalate (MnBP) was associated with higher Th2% (RR: 10.40, 95% CI: 3.37, 17.92), and methyl paraben was associated with lower Th1% (RR: -3.35, 95% CI: -6.58, -0.02) and Th2% at borderline significance (RR: -4.45, 95% CI: -8.77, 0.08). Monoethyl phthalate was associated with lower forced expiratory flow from 25 to 75% of forced vital capacity (FEF25-75%) (RR: -3.22 L/s, 95% CI: -6.02, -0.34). Propyl paraben (OR: 0.86, 95% CI: 0.74, 0.99) was associated with decreased odds of probable asthma.

CONCLUSIONS

While some biomarkers, particularly those from low molecular weight phthalates, were associated with an atopic cytokine profile and poorer lung function, no biomarkers were associated with a corresponding increase in atopic disease.