Heme oxygenase-1 protects against PM2.5 induced endothelial dysfunction through inhibition of HIF1α

Fine particulate matter potentiates Th17-cell pathogenicity in experimental autoimmune uveitis via ferroptosis

The effect of fine particulate matter (PM2.5) on the development of uveitis remains unclear. Therefore, this study was designed to investigate the role of PM2.5 in experimental autoimmune uveitis (EAU) and its potential mechanism. Our results showed that PM2.5 could exacerbate the activity of EAU, as evidenced by severer clinical and pathological changes, correlated with elevated Th17 cells frequency and IL-17A expression. Proteomic analysis revealed ferroptosis was the most significant pathway. In vivo, the levels of Fe2+, ROS, lipid ROS, and malondialdehyde, as well as the expression of TFRC, HMOX1, FTH1, and FTL1 in CD4+ T cells were increased, while GSH/GSSG ratio and the expression of ACSL1 and GPX4 were decreased after PM2.5 exposure. In vitro, the expression of TFRC and HMOX1 were increased, while the expression FTH1, FTL1, ACSL1, and GPX4 were decreased after PM2.5 exposure. Ferrostatin-1 effectively alleviated PM2.5-induced intraocular inflammation and suppressed the frequency of Th17 cells. These results suggest that PM2.5 could aggravate intraocular inflammation and immune response in EAU mice through ferroptosis. Ferroptosis could be a potential marker for the prevention and treatment of uveitis.

Interactions of Potential Endocrine-Disrupting Chemicals with Whole Human Proteome Predicted by AlphaFold2 Using an In Silico Approach

Binding with proteins is a critical molecular initiating event through which environmental pollutants exert toxic effects in humans. Previous studies have been limited by the availability of three-dimensional (3D) protein structures and have focused on only a small set of environmental contaminants. Using the highly accurate 3D protein structure predicted by AlphaFold2, this study explored over 60 million interactions obtained through molecular docking between 20,503 human proteins and 1251 potential endocrine-disrupting chemicals. A total of 66,613,773 docking results were obtained, 1.2% of which were considered to be high binding, as their docking scores were lower than -7. Monocyte to macrophage differentiation factor 2 (MMD2) was predicted to interact with the highest number of environmental pollutants (526), with polychlorinated biphenyls and polychlorinated dibenzofurans accounting for a significant proportion. Dimension reduction and clustering analysis revealed distinct protein profiles characterized by high binding affinities for perfluoroalkyl and polyfluoroalkyl substances (PFAS), phthalate-like chemicals, and other pollutants, consistent with their uniquely enriched pathways. Further structural analysis indicated that binding pockets with a high proportion of charged amino acid residues, relatively low α-helix content, and high β-sheet content were more likely to bind to PFAS than others. This study provides insights into the toxicity pathways of various pollutants impacting human health and offers novel perspectives for the establishment and expansion of adverse outcome pathway-based models.

Disruption of Atrial Rhythmicity by the Air Pollutant 1,2-Naphthoquinone: Role of Beta-Adrenergic and Sensory Receptors

The combustion of fossil fuels contributes to air pollution (AP), which was linked to about 8.79 million global deaths in 2018, mainly due to respiratory and cardiovascular-related effects. Among these, particulate air pollution (PM2.5) stands out as a major risk factor for heart health, especially during vulnerable phases. Our prior study showed that premature exposure to 1,2-naphthoquinone (1,2-NQ), a chemical found in diesel exhaust particles (DEP), exacerbated asthma in adulthood. Moreover, increased concentration of 1,2-NQ contributed to airway inflammation triggered by PM2.5, employing neurogenic pathways related to the up-regulation of transient receptor potential vanilloid 1 (TRPV1). However, the potential impact of early-life exposure to 1,2-naphthoquinone (1,2-NQ) on atrial fibrillation (AF) has not yet been investigated. This study aims to investigate how inhaling 1,2-NQ in early life affects the autonomic adrenergic system and the role played by TRPV1 in these heart disturbances. C57Bl/6 neonate male mice were exposed to 1,2-NQ (100 nM) or its vehicle at 6, 8, and 10 days of life. Early exposure to 1,2-NQ impairs adrenergic responses in the right atria without markedly affecting cholinergic responses. ECG analysis revealed altered rhythmicity in young mice, suggesting increased sympathetic nervous system activity. Furthermore, 1,2-NQ affected β1-adrenergic receptor agonist-mediated positive chronotropism, which was prevented by metoprolol, a β1 receptor blocker. Capsazepine, a TRPV1 blocker but not a TRPC5 blocker, reversed 1,2-NQ-induced cardiac changes. In conclusion, neonate mice exposure to AP 1,2-NQ results in an elevated risk of developing cardiac adrenergic dysfunction, potentially leading to atrial arrhythmia at a young age.

Bilirubin Concentration in Follicular Fluid Is Increased in Infertile Females, Correlates with Decreased Antioxidant Levels and Increased Nitric Oxide Metabolites, and Negatively Affects Outcome Measures of In Vitro Fertilization

In a previous study, we showed that various low-molecular-weight compounds in follicular fluid (FF) samples of control fertile females (CFF) have different concentrations compared to those found in FF of infertile females (IF), before and after their categorization into different subgroups, according to their clinical diagnosis of infertility. Using the same FF samples of this previous study, we here analyzed the FF concentrations of free and bound bilirubin and compared the results obtained in CFF, IF and the different subgroups of IF (endometriosis, EM, polycystic ovary syndrome, PCOS, age-related reduced ovarian reserve, AR-ROR, reduced ovarian reserve, ROR, genetic infertility, GI and unexplained infertility, UI). The results clearly indicated that CFF had lower values of free, bound and total bilirubin compared to the respective values measured in pooled IF. These differences were observed even when IF were categorized into EM, PCOS, AR-ROR, ROR, GI and UI, with EM and PCOS showing the highest values of free, bound and total bilirubin among the six subgroups. Using previous results of ascorbic acid, GSH and nitrite + nitrate measured in the same FF samples of the same FF donors, we found that total bilirubin in FF increased as a function of decreased values of ascorbic acid and GSH, and increased concentrations of nitrite + nitrate. The values of total bilirubin negatively correlated with the clinical parameters of fertilization procedures (number of retrieved oocytes, mature oocytes, fertilized oocytes, blastocysts, high-quality blastocysts) and with clinical pregnancies and birth rates. Bilirubin concentrations in FF were not linked to those found in serum samples of FF donors, thereby strongly suggesting that its over production was due to higher activity of heme oxygenase-1 (HO-1), the key enzyme responsible for bilirubin formation, in granulosa cells, or cumulus cells or oocytes of IF and ultimately leading to bilirubin accumulation in FF. Since increased activity of HO-1 is one of the main enzymatic intracellular mechanisms of defense towards external insults (oxidative/nitrosative stress, inflammation), and since we found correlations among bilirubin and oxidative/nitrosative stress in these FF samples, it may reasonably be supposed that bilirubin increase in FF of IF is the result of protracted exposures to the aforementioned insults evidently playing relevant roles in female infertility.