Effect of particulate matter 2.5 on gene expression profile and cell signaling in JEG-3 human placenta cells

Pollution and endometriosis: A deep dive into the environmental impacts on women's health

BACKGROUND

The interaction between pollution and endometriosis is a pressing issue that demands immediate attention. The impact of pollution, particularly air and water pollution, or occupational hazards, on hormonal disruption and the initiation of endometriosis remains a major issue.

OBJECTIVES

This narrative review aims to delve into the intricate connection between pollution and endometriosis, shedding light on how environmental factors contribute to the onset and severity of this disease and, thus, the possible public health policy implications.

DISCUSSION

Endocrine-disrupting chemicals (EDCs) in pollutants dysregulate the hormonal balance, contributing to the progression of this major gynaecological disorder. Air pollution, specifically PM2.5 and PAHs, has been associated with an increased risk of endometriosis by enhancing chronic inflammation, oxidative stress, and hormonal imbalances. Chemical contaminants in water and work exposures, including heavy metals, dioxins, and PCBs, disrupt the hormonal regulation and potentially contribute to endometriosis. Mitigating the environmental impact of pollution is required to safeguard women's reproductive health. This requires a comprehensive approach involving stringent environmental regulations, sustainable practices, responsible waste management, research and innovation, public awareness, and collaboration among stakeholders.

CONCLUSION

Public health policies have a major role in addressing the interaction between pollution and endometriosis in a long-term commitment.

The cytotoxicity of PM2.5 and its effect on the secretome of normal human bronchial epithelial cells

Exposure to airborne fine particulate matter (PM_2.5) induced various adverse health effects, such as metabolic syndrome, systemic inflammation, and respiratory disease. Many works have studied the effects of PM_2.5 exposure on cells through intracellular proteomics analyses. However, changes of the extracellular proteome under PM_2.5 exposure and its correlation with PM_2.5-induced cytotoxicity still remain unclear. Herein, the cytotoxicity of PM_2.5 on normal human bronchial epithelia cells (BEAS-2B cells) was evaluated, and the secretome profile of BEAS-2B cells before and after PM_2.5 exposure was investigated. A total of 83 proteins (58 upregulated and 25 downregulated) were differentially expressed in extracellular space after PM_2.5 treatment. Notably, we found that PM_2.5 promoted the release of several pro-apoptotic factors and induced dysregulated secretion of extracellular matrix (ECM) constituents, showing that the abnormal extracellular environment attributed to PM_2.5-induced cell damage. This study provided a secretome data for the deep understanding of the molecular mechanism underlying PM_2.5-caused human bronchial epithelia cell damage.

Synergistic protective effects of folic acid and resveratrol against fine particulate matter-induced heart malformations in zebrafish embryos

Ambient fine particulate matter (PM2.5) is a major environmental health problem worldwide, and recent studies indicate that maternal PM2.5 exposure is closely associated with congenital heart diseases (CHDs) in offspring. We previously found that supplementation with folic acid (FA) or Resveratrol (RSV) could protect against heart defects in zebrafish embryos exposed to extractable organic matter (EOM) from PM2.5 by targeting aryl hydrocarbon receptor (AHR) signaling and reactive oxygen species (ROS) production respectively. Thus, we hypothesized that FA combined with RSV may have a synergistic protective effect against PM2.5-induced heart defects. To test our hypothesis, we treated zebrafish embryos with EOM in the presence or absence of FA, RSV or a combination of both. We found that RSV and FA showed a clear synergistic protection against EOM-induced heart defects in zebrafish embryos. Further studies showed that FA and RSV suppressed EOM-induced AHR activity and ROS generation respectively. Although only RSV inhibited EOM-induced apoptosis, FA enhanced the inhibitory effect of RSV. Moreover, vitamin C (VC), a typical antioxidant, also exhibits a synergistic inhibitory effect with FA on EOM-induced apoptosis and heart defects. In conclusion, supplementation with FA and RSV have a synergistic protective effect against PM2.5-induced heart defects in zebrafish embryos by targeting AHR activity and ROS production respectively. Our results indicate that, in the presence of antioxidants, FA even at a low concentration level could protect against the high risk of CHDs caused by air pollution.

Prenatal exposure to particulate matter and placental gene expression

BACKGROUND

While strong evidence supports adverse maternal and offspring consequences of air pollution, mechanisms that involve the placenta, a key part of the intrauterine environment, are largely unknown. Previous studies of air pollution and placental gene expression were small candidate gene studies that rarely considered prenatal windows of exposure or the potential role of offspring sex. We examined overall and sex-specific associations of prenatal exposure to fine particulate matter (PM_2.5) with genome-wide placental gene expression.

METHODS

Participants with placenta samples, collected at birth, and childhood health outcomes from CANDLE (Memphis, TN) (n = 776) and GAPPS (Seattle, WA) (n = 205) cohorts of the ECHO-PATHWAYS Consortium were included in this study. PM_2.5 exposures during trimesters 1, 2, 3, and the first and last months of pregnancy, were estimated using a spatiotemporal model. Cohort-specific linear adjusted models were fit for each exposure window and expression of >11,000 protein coding genes from paired end RNA sequencing data. Models with interaction terms were used to examine PM_2.5-offspring sex interactions. False discovery rate (FDR < 0.10) was used to correct for multiple testing.

RESULTS

Mean PM_2.5 estimate was 10.5-10.7 μg/m³ for CANDLE and 6.0-6.3 μg/m³ for GAPPS participants. In CANDLE, expression of 13 (11 upregulated and 2 downregulated), 20 (11 upregulated and 9 downregulated) and 3 (2 upregulated and 1 downregulated) genes was associated with PM_2.5 in the first trimester, second trimester, and first month, respectively. While we did not find any statistically significant association, overall, between PM_2.5 and gene expression in GAPPS, we found offspring sex and first month PM_2.5 interaction for DDHD1 expression (positive association among males and inverse association among females). We did not observe PM_2.5 and offspring sex interactions in CANDLE.

CONCLUSION

In CANDLE, but not GAPPS, we found that prenatal PM_2.5 exposure during the first half of pregnancy is associated with placental gene expression.

Maternal steroids during pregnancy and their associations with ambient air pollution and temperature during preconception and early gestational periods

Hormones play critical roles in facilitating pregnancy progression and the onset of parturition. Several classes of environmental contaminants, including fine particulate matter (PM_2.5) and ambient temperature, have been shown to alter hormone biosynthesis or activity. However, epidemiologic research has not considered PM_2.5 in relation to a broader range of steroid hormones, particularly in pregnant women. Using metabolomics data collected within 20-40 weeks of gestation in an ethnically diverse pregnancy cohort study, we identified 42 steroid hormones that we grouped into five classes (pregnenolone, androgens, estrogens, progestin, and corticosteroids) based on their biosynthesis type. We found that exposure to PM_2.5 during the pre-conception and early prenatal periods was associated with higher maternal androgen concentrations in late pregnancy. We also detected a positive association between early pregnancy PM_2.5 exposure and maternal pregnenolone levels and a marginal positive association between early pregnancy PM_2.5 exposure and progestin levels. When considering each hormone metabolite individually, we found positive associations between early pregnancy PM_2.5 exposure and five steroids, two of which survived multiple comparison testing: 11beta-hydroxyandrosterone glucuronide (a pregnenolone steroid) and adrosteroneglucuronide (a progestin steroid). None of the steroid classes were statistically significant associated with ambient temperature. In sex-stratified analyses, we did not detect any sex differences in our associations. This is the first study showing that exposure to fine particulate matter during the pre-conception and early prenatal periods can lead to altered steroid adaptation during the state of pregnancy, which has been shown to have potential consequences on maternal and child health.

Mechanistic toxicity assessment of fine particulate matter emitted from fuel combustion via pathway-based approaches in human cells

Fuel exhaust particulate matter (FEPM) is an important source of air pollution worldwide. However, the comparative and mechanistic toxicity of FEPMs emitted from combustion of different fuels is still not fully understood. This study employed pathway-based approaches via human cells to evaluate mechanistic toxicity of FEPMs. The results showed that FEPMs caused concentration-dependent (0.1-200 μg/mL) cytotoxicity and oxidative stress. FEPMs at low concentration (10 μg/mL) induced cell cycle arrest in S and G2 phases, while high level of FEPMs (200 μg/mL) caused cell cycle arrest in G1 phase. Different FEPMs induced distinct expression profiles of toxicity-related genes, illustrating different toxic mechanisms. Furthermore, FEPMs inhibited the phosphorylation of protein kinase A (PKA), which related with reproductive toxicity. Spearman rank correlations among the chemicals carried by FEPMs and the toxic effects revealed that PAHs and metals promoted cell cycle arrest in the G1 phase and suppressed PKA activity. Furthermore, PAHs (Nap and Acy) and metals (Al and Pb) in FEPMs were highly and positively correlated with the expression of genes involved in apoptosis, ER stress, metal stress and inflammation. Our findings offered more mechanistic information of FEPMs at the level of subcellular toxicity and help to better understand their potential health effects.

The circular RNA circTXNRD1 promoted ambient particulate matter-induced inflammation in human bronchial epithelial cells by regulating miR-892a/COX-2 axis

Particulate matter (PM)-induced airway inflammation contributes to the development and exacerbation of chronic airway diseases. Circular RNA (circRNA) is a new class of non-coding RNA that participates in gene regulation in various respiratory diseases, but the regulatory role of circRNA in PM-induced airway inflammation has not been fully elucidated. In this study, we performed the human circRNA microarray to reveal differentially expressed circRNAs in PM-induced human bronchial epithelial cells (HBECs). A total of 176 upregulated and 15 downregulated circRNAs were identified. Of these, a new circRNA termed circTXNRD1 was upregulated by PM exposure in a dose- and time-dependent manner. Knockdown of circTXNRD1 significantly attenuated PM-induced expression of proinflammatory cytokine interleukin 6 (IL-6). CircRNA pull-down, dual-luciferase reporter assay and fluorescence in situ hybridization showed that circTXNRD1 acted as an endogenous sponge to decrease miR-892a levels in HBECs. Downregulation of miR-892a could increase cyclooxygenase-2 (COX-2) expression and eventually promote IL-6 secretion in PM-induced HBECs. Taken together, our findings reveal circTXNRD1 as a novel inflammatory mediator in PM-induced inflammation in HBECs via regulating miR-892a/COX-2 axis. These results provide new insight into the biological mechanism underlying PM-induced inflammation in chronic airway diseases.

Transcriptomics changes and the candidate pathway in human macrophages induced by different PM2.5 extracts

Ambient fine particulate matter (PM_2.5) is a worldwide environmental problem and is posing a serious threat to human health. Until now, the molecular toxicological mechanisms and the crucial toxic components of PM_2.5 remain to be clarified. This study investigated the whole transcriptomic changes in THP-1 derived macrophages treated with different types of PM_2.5 extracts using RNA sequencing technique. Bioinformatics analyses covering biological functions, signal pathways, protein networks and node genes were performed to explore the candidate pathways and critical genes, and to find the potential molecular mechanisms. Results of Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes pathway (KEGG), and protein-protein interaction (PPI) networks revealed that water extracts (WEs) of PM_2.5 obviously influenced genes and molecular pathways responded to oxidative stress and inflammation. Dichloromethane extracts (DEs) specifically affected genes and signal cascades related to cell cycle progress process. Furthermore, compared with WEs collected in heating season, non-heating season WEs induced much higher expression levels of Ca-associated genes (including phosphodiesterase 4B and cyclooxygenase-2), which may consequently result in more severe inflammatory responses. While, for DEs exposure, the heating season (DH) group showed extensive induction of deferentially expressed genes (DEGs) related to cell cycle pathway, which may be caused by the higher polycyclic aromatic hydrocarbons (PAHs) contents in DH samples than those from non-heating season. In conclusion, the oxidative stress and inflammation response are closely correlated with cellular responses in THP-1 derived macrophages induced by water soluble components of PM_2.5, and cell cycle dysregulation may play an important role in biological effects induced by organic components. The different transcriptomic changes induced by seasonal PM_2.5 extracts may partially depend on the contents of PAHs and metal ions, respectively.

Overview of human 20 alpha-hydroxysteroid dehydrogenase (AKR1C1): Functions, regulation, and structural insights of inhibitors

Human aldo-keto reductase family 1C1 (AKR1C1) is an important enzyme involved in human hormone metabolism, which is mainly responsible for the metabolism of progesterone in the human body. AKR1C1 is highly expressed and has an important relationship with the occurrence and development of various diseases, especially some cancers related to hormone metabolism. Nowadays, many inhibitors against AKR1C1 have been discovered, including some synthetic compounds and natural products, which have certain inhibitory activity against AKR1C1 at the target level. Here we briefly reviewed the physiological and pathological functions of AKR1C1 and the relationship with the disease, and then summarized the development of AKR1C1 inhibitors, elucidated the interaction between inhibitors and AKR1C1 through molecular docking results and existing co-crystal structures. Finally, we discussed the design ideals of selective AKR1C1 inhibitors from the perspective of AKR1C1 structure, discussed the prospects of AKR1C1 in the treatment of human diseases in terms of biomarkers, pre-receptor regulation and single nucleotide polymorphisms, aiming to provide new ideas for drug research targeting AKR1C1.

Transcriptomics and Other Omics Approaches to Investigate Effects of Xenobiotics on the Placenta

The conceptus is most vulnerable to developmental perturbation during its early stages when the events that create functional organ systems are being launched. As the placenta is in direct contact with maternal tissues, it readily encounters any xenobiotics in her bloodstream. Besides serving as a conduit for solutes and waste, the placenta possesses a tightly regulated endocrine system that is, of itself, vulnerable to pharmaceutical agents, endocrine disrupting chemicals (EDCs), and other environmental toxicants. To determine whether extrinsic factors affect placental function, transcriptomics and other omics approaches have become more widely used. In casting a wide net with such approaches, they have provided mechanistic insights into placental physiological and pathological responses and how placental responses may impact the fetus, especially the developing brain through the placenta-brain axis. This review will discuss how such omics technologies have been utilized to understand effects of EDCs, including the widely prevalent plasticizers bisphenol A (BPA), bisphenol S (BPS), and phthalates, other environmental toxicants, pharmaceutical agents, maternal smoking, and air pollution on placental gene expression, DNA methylation, and metabolomic profiles. It is also increasingly becoming clear that miRNA (miR) are important epigenetic regulators of placental function. Thus, the evidence to date that xenobiotics affect placental miR expression patterns will also be explored. Such omics approaches with mouse and human placenta will assuredly provide key biomarkers that may be used as barometers of exposure and can be targeted by early mitigation approaches to prevent later diseases, in particular neurobehavioral disorders, originating due to placental dysfunction.

Exposure to ambient dusty particulate matter impairs spatial memory and hippocampal LTP by increasing brain inflammation and oxidative stress in rats

OBJECTIVES

Exposure of healthy subjects to ambient airborne dusty particulate matter (PM) causes brain dysfunction. This study aimed to investigate the effect of sub-chronic inhalation of ambient PM in a designed special chamber to create factual dust storm (DS) conditions on spatial cognition, hippocampal long-term potentiation (LTP), inflammatory cytokines, and oxidative stress in the brain tissue.

METHODS

Adult male Wistar rats (250-300 g) were randomly divided into four groups: Sham (clean air, the concentration of dusty PM was <150 μg/m³), DS1 (200-500 μg/m³), DS2 (500-2000 μg/m³) and DS3 (2000-8000 μg/m³). Experimental rats were exposed to clean air or different sizes and concentrations of dust PM storm for four consecutive weeks (exposure was during 1-4, 8-11, 15-16 and 20-23 days, 30 min, twice daily) in a real-ambient dust exposure chamber. Subsequently, cognitive performance, hippocampal LTP, blood-brain barrier (BBB) permeability and brain edema of the animals evaluated. As well as, inflammatory cytokines and oxidative stress indexes in the brain tissue measured using ELISA assays.

RESULTS

Exposing to dust PM impaired spatial memory (p < 0.001), hippocampal LTP (p < 0.001). These disturbances were in line with the severe damage to respiratory system followed by disruption of BBB integrity (p < 0.001), increased brain edema (p < 0.001), inflammatory cytokines (p < 0.001) excretion and oxidative stress (p < 0.001) in brain tissue.

CONCLUSIONS

Our study showed that exposure to ambient dust PM increased brain edema and BBB permeability, induced memory impairment and hippocampal LTP deficiency by increasing the inflammatory responses and oxidative stress in the brain of the rats.