Wogonin alleviates BaP-induced DNA damage and oxidative stress in human airway epithelial cells by dual inhibiting CYP1A1 activity and expression

Long-term chronic exposure to benzo[a]pyrene and catechol induced multidrug resistance in lung cancer cells

Multiple studies have raised concerns about the impact of long-term exposure to environmental pollutants on the occurrence and progression of cancer, but little is known about how these compounds affect the treatment of cancer patients. In this work, two common pollutants including benzo [a]pyrene (B [a]P) and catechol (CL) were tested for their chronic effects on the efficacy of common chemotherapeutic drug in lung cancer (A549) cells. Both pollutants were unlikely to be the substrates of ABC transporters, as their toxicity was unaffected by ABC transporter inhibitors. However, their repeated exposure led to the generation of chemoresistance to doxorubicin (DOX) and cisplatin (CDDP), indicating the formation of multidrug-resistance (MDR) cells. Compared with DOX-resistant cells, decreased expression of ABC transporters but increased responses were found in pollutants-resistant cells. In addition, pollutants-resistant cells were more potent in up-regulating anti-apoptosis, proliferation, and migration pathways, which were confirmed by the wound-healing and apoptosis assays. Overall, these results indicated a distinct MDR mechanism induced by non-substrate pollutants, and could be beneficial for understanding the environmental risk of pollutants in their "safe" concentrations.

Identification of benzo(a)pyrene-related toxicological targets and their role in chronic obstructive pulmonary disease pathogenesis: a comprehensive bioinformatics and machine learning approach

BACKGROUND

Chronic obstructive pulmonary disease (COPD) pathogenesis is influenced by environmental factors, including Benzo(a)pyrene (BaP) exposure. This study aims to identify BaP-related toxicological targets and elucidate their roles in COPD development.

METHODS

A comprehensive bioinformatics approach was employed, including the retrieval of BaP-related targets from the Comparative Toxicogenomics Database (CTD) and Super-PRED database, identification of differentially expressed genes (DEGs) from the GSE76925 dataset, and protein-protein interaction (PPI) network analysis. Functional enrichment and immune infiltration analyses were conducted using GO, KEGG, and ssGSEA algorithms. Feature genes related to BaP exposure were identified using SVM-RFE, Lasso, and RF machine learning methods. A nomogram was constructed and validated for COPD risk prediction. Molecular docking was performed to evaluate the binding affinity of BaP with proteins encoded by the feature genes.

RESULTS

We identified 72 differentially expressed BaP-related toxicological targets in COPD. Functional enrichment analysis highlighted pathways related to oxidative stress and inflammation. Immune infiltration analysis revealed significant increases in B cells, DC, iDC, macrophages, T cells, T helper cells, Tcm, and TFH in COPD patients compared to controls. Correlation analysis showed strong links between oxidative stress, inflammation pathway scores, and the infiltration of immune cells, including aDC, macrophages, T cells, Th1 cells, and Th2 cells. Seven feature genes (ACE, APOE, CDK1, CTNNB1, GATA6, IRF1, SLC1A3) were identified across machine learning methods. A nomogram based on these genes showed high diagnostic accuracy and clinical utility. Molecular docking revealed the highest binding affinity of BaP with CDK1, suggestive of its pivotal role in BaP-induced COPD pathogenesis.

CONCLUSIONS

The study elucidates the molecular mechanisms of BaP-induced COPD, specifically highlighting the role of oxidative stress and inflammation pathways in promoting immune cell infiltration. The identified feature genes may serve as potential biomarkers and therapeutic targets. Additionally, the constructed nomogram demonstrates high accuracy in predicting COPD risk, providing a valuable tool for clinical application in BaP-exposed individuals.

Mediation of FOXA2/IL-6/IL-6R/STAT3 signaling pathway mediates benzo[a]pyrene-induced airway epithelial mesenchymal transformation in asthma

Benzo [a]pyrene (BaP), a toxic pollutant, increases the incidence and severity of asthma. However, the molecular mechanisms underlying the effects of BaP in asthma remain unclear. In terms of research methods, we used BaP to intervene in the animal model of asthma and the human bronchial epithelial (16HBE) cells, and the involved mechanisms were found from the injury, inflammation, and airway epithelial to mesenchymal transition (EMT) in asthma. We also constructed small interfering RNAs and overexpression plasmids to knockdown/overexpress IL-6R and FOXA2 in 16HBE cells and a serotype 9 adeno-associated viral vector for lung tissue overexpression of FOXA2 in mice to determine the mechanism of action of BaP-exacerbated asthma airway EMT. We observed that BaP aggravated inflammatory cell infiltration into the lungs, reduced the Penh value, increased collagen fibres in the lung tissue, and increased serum IgE levels in asthmatic mice. After BaP intervention, the expression of FOXA2 in the lung tissue of asthmatic mice decreased, the production and secretion of IL-6 were stimulated, and STAT3 phosphorylation and nuclear translocation increased, leading to changes in EMT markers. However, EMT decreased after increasing FOXA2 expression and decreasing that of IL-6R and was further enhanced after low FOXA2 expression. Our results revealed that BaP exacerbated airway epithelial cell injury and interfered with FOXA2, activating the IL-6/IL-6R/STAT3 signaling pathway to promote airway EMT in asthma. These findings provide toxicological evidence for the mechanism underlying the contribution of BaP to the increased incidence of asthma and its exacerbations.

Wogonin protects against bleomycin-induced mouse pulmonary fibrosis via the inhibition of CDK9/p53-mediated cell senescence

Pulmonary fibrosis (PF) is a fatal interstitial lung disease associated with declining pulmonary function but currently with few effective drugs. Cellular senescence has been implicated in the pathogenesis of PF and could be a potential therapeutic target. Emerging evidence suggests wogonin, the bioactive compound isolated from Scutellaria baicalensis, owns the anti-senescence properties, however, the possible impact of wogonin on PF and the potential mechanisms remain unclear. In this study, a well-established mouse model of PF was utilized which mice were administrated with bleomycin (BLM). Strikingly, wogonin treatment significantly reduced fibrosis deposition in the lung induced by BLM. In vitro, wogonin also suppressed fibrotic markers of cultured epithelial cells stimulated by BLM or hydrogen peroxide. Mechanistic investigation revealed that wogonin attenuated the expressions of DNA damage marker γ-H2AX and senescence-related markers including phosphorylated p53, p21, retinoblastoma protein (pRB), and senescence-associated β-galactosidase (SA-β-gal). Moreover, wogonin, as a direct and selective inhibitor of cyclin-dependent kinase 9 (CDK9), exhibited anti-fibrotic capacity by inhibiting CDK9 and p53/p21 signalling. In conclusion, wogonin protects against BLM-induced PF in mice through the inhibition of cell senescence via the regulation of CDK9/p53 and DNA damage pathway. This is the first study to demonstrate the beneficial effect of wogonin on PF, and its implication as a novel candidate for PF therapy.

Hepatoprotective Effects of Flavonoids against Benzo[a]Pyrene-Induced Oxidative Liver Damage along Its Metabolic Pathways

Benzo[a]pyrene (B[a]P), a highly carcinogenic polycyclic aromatic hydrocarbon primarily formed during incomplete organic matter combustion, undergoes a series of hepatic metabolic reactions once absorbed into the body. B[a]P contributes to liver damage, ranging from molecular DNA damage to the onset and progression of various diseases, including cancer. Specifically, B[a]P induces oxidative stress via reactive oxygen species generation within cells. Consequently, more research has focused on exploring the underlying mechanisms of B[a]P-induced oxidative stress and potential strategies to counter its hepatic toxicity. Flavonoids, natural compounds abundant in plants and renowned for their antioxidant properties, possess the ability to neutralize the adverse effects of free radicals effectively. Although extensive research has investigated the antioxidant effects of flavonoids, limited research has delved into their potential in regulating B[a]P metabolism to alleviate oxidative stress. This review aims to consolidate current knowledge on B[a]P-induced liver oxidative stress and examines the role of flavonoids in mitigating its toxicity.

The Anticancer Effects of the Garlic Organosulfide Diallyl Trisulfide through the Attenuation of B[a]P-Induced Oxidative Stress, AhR Expression, and DNA Damage in Human Premalignant Breast Epithelial (MCF-10AT1) Cells

Benzo[a]pyrene (B[a]P) is the most characterized polycyclic aromatic hydrocarbon associated with breast cancer. Our lab previously reported that the organosulfur compound (OSC), diallyl trisulfide (DATS), chemoprevention mechanism works through the induction of cell cycle arrest and a reduction in oxidative stress and DNA damage in normal breast epithelial cells. We hypothesize that DATS will inhibit B[a]P-induced cancer initiation in premalignant breast epithelial (MCF-10AT1) cells. In this study, we evaluated the ability of DATS to attenuate B[a]P-induced neoplastic transformation in MCF-10AT1 cells by measuring biological endpoints such as proliferation, clonogenicity, reactive oxygen species (ROS) formation, and 8-hydroxy-2-deoxyguanosine (8-OHdG) DNA damage levels, as well as DNA repair and antioxidant proteins. The results indicate that B[a]P induced proliferation, clonogenic formation, ROS formation, and 8-OHdG levels, as well as increasing AhR, ARNT/HIF-1β, and CYP1A1 protein expression compared with the control in MCF-10AT1 cells. B[a]P/DATS's co-treatment (CoTx) inhibited cell proliferation, clonogenic formation, ROS formation, AhR protein expression, and 8-OHdG levels compared with B[a]P alone and attenuated all the above-mentioned B[a]P-induced changes in protein expression, causing a chemopreventive effect. This study demonstrates, for the first time, that DATS prevents premalignant breast cells from undergoing B[a]P-induced neoplastic transformation, thus providing more evidence for its chemopreventive effects in breast cancer.