Pulmonary oxidative stress, inflammation and cancer: respirable particulate matter, fibrous dusts and ozone as major causes of lung carcinogenesis through reactive oxygen species mechanisms

Ferroptosis-Related Genes in Lung Adenocarcinoma: Prognostic Signature and Immune, Drug Resistance, Mutation Analysis

It is reported that ferroptosis has close relation with tumorigenesis and drug resistance. However, the clinical significance of ferroptosis in lung adenocarcinoma (LUAD) remains elusive, and the potential targets for ferroptosis-based treatment are limited. In this study, we constructed a 15-gene prognostic signature predicting overall survival based on ferroptosis-related genes (ferroptosis driver genes VDAC2, GLS2, FLT3, TLR4, PHKG2, phosphogluconate dehydrogenase (PGD), PANX1, KRAS, PEBP1, ALOX15, and ALOX12B, and suppressor genes ACSL3, CISD1, FANCD2, and SLC3A2) in The Cancer Genome Atlas (TCGA)-LUAD cohort. The signature’s predictive ability was validated in the GSE68465 and GSE72094 cohorts by survival analysis and independent prognostic analysis with clinical features. Nomograms were provided for clinical reference. Functional analysis revealed that ferroptosis was closely related to cell cycle, cell metabolism, and immune pathways. Pan-cancer analysis comprehensively analyzed these 15 genes in 33 cancer types, indicating that the heterogeneity of 15 genes was evident across different cancer types. Besides, these genes were critical regulators modulating drug resistance, tumor microenvironment infiltration, and cancer stemness. Then, we screened 10 genes (TLR4, PHKG2, PEBP1, GLS2, FLT3, ALOX15, ACSL3, CISD1, FANCD2, and SLC3A2) as potential targets for further research because their biological functions in ferroptosis were consistent with their prognostic significance. Somatic mutation and copy number variation analysis revealed that the alteration rates of KRAS, PGD, and ALOX15 were more than 1% and significantly associated with overall survival in LUAD. Moreover, the expression of KRAS and PGD was positively related to tumor mutation burden, indicating that KRAS and PGD could serve as novel biomarkers for predicting immunotherapy response rate. Our study identified and validated a ferroptosis-related gene signature for LUAD, provided a 10-gene set for future research, and screened KRAS and PGD as potential novel immunotherapy biomarkers.

The Role of Fossil Fuel Combustion Metals in PM2.5 Air Pollution Health Associations

In this review, we elucidate the central role played by fossil fuel combustion in the health-related effects that have been associated with inhalation of ambient fine particulate matter (PM2.5). We especially focus on individual properties and concentrations of metals commonly found in PM air pollution, as well as their sources and their adverse health effects, based on both epidemiologic and toxicological evidence. It is known that transition metals, such as Ni, V, Fe, and Cu, are highly capable of participating in redox reactions that produce oxidative stress. Therefore, particles that are enriched, per unit mass, in these metals, such as those from fossil fuel combustion, can have greater potential to produce health effects than other ambient particulate matter. Moreover, fossil fuel combustion particles also contain varying amounts of sulfur, and the acidic nature of the resulting sulfur compounds in particulate matter (e.g., as ammonium sulfate, ammonium bisulfate, or sulfuric acid) makes transition metals in particles more bioavailable, greatly enhancing the potential of fossil fuel combustion PM2.5 to cause oxidative stress and systemic health effects in the human body. In general, there is a need to further recognize particulate matter air pollution mass as a complex source-driven mixture, in order to more effectively quantify and regulate particle air pollution exposure health risks.

Systems level insights into the impact of airborne exposure on SARS-CoV-2 pathogenesis and COVID-19 outcome - A multi-omics big data study

Coronavirus disease 2019 (COVID-19) is a viral pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that led to more than 800,00 deaths and continues to be a major threat worldwide. The scientific community has been studying the risk factors associated with SARS-CoV-2 infection and pathogenesis. Recent studies highlight the possible contribution of atmospheric air pollution, specifically particulate matter (PM) exposure as a co-factor in COVID-19 severity. Hence, meaningful translation of suitable omics datasets of SARS-CoV-2 infection and PM exposure is warranted to understand the possible involvement of airborne exposome on COVID-19 outcome. Publicly available transcriptomic data (microarray and RNA-Seq) related to COVID-19 lung biopsy, SARS-CoV-2 infection in epithelial cells and PM exposure (lung tissue, epithelial and endothelial cells) were obtained in addition with proteome and interactome datasets. System-wide pathway/network analysis was done through appropriate software tools and data resources. The primary findings are; 1. There is no robust difference in the expression of SARS-CoV-2 entry factors upon particulate exposure, 2. The upstream pathways associated with upregulated genes during SARS-CoV-2 infection considerably overlap with that of PM exposure, 3. Similar pathways were differentially expressed during SARS-CoV-2 infection and PM exposure, 4. SARS-CoV-2 interacting host factors were predicted to be associated with the molecular impact of PM exposure and 5. Differentially expressed pathways during PM exposure may increase COVID-19 severity. Based on the observed molecular mechanisms (direct and indirect effects) the current study suggests that airborne PM exposure has to be considered as an additional co-factor in the outcome of COVID-19.

Natural Products with tandem Anti-inflammatory, Immunomodulatory and Anti-SARS-CoV/2 effects: A Drug Discovery Perspective against SARS-CoV-2

BACKGROUND

COVID-19 is still causing victims with long-term health consequences, mass deaths, and collapsing healthcare systems around the world. The disease has no efficient drugs. However, previous studies revealed that SARS-CoV-2 and SARS-CoV have 96% and 86.5% similarities in cysteine proteases (3CL^pro) and papain-like protease (PL^pro) sequences, respectively. This resemblance could be significant in the search for drug candidates with antiviral effects against SARS-CoV-2.

OBJECTIVE

This paper is a compilation of natural products that inhibit SARS-CoV 3CL^pro and PL^pro and, concomitantly, reduce inflammation and/or modulate the immune system as a perspective strategy for COVID-19 drug discovery. It also presents in silico studies performed on these selected natural products using SARS-CoV-2 3CL^pro and PL^pro as targets to propose a list of hit compounds.

METHOD

The plant metabolites were selected in the literature based on their biological activities on SARS-CoV proteins, inflammatory mediators, and immune response. The consensus docking analysis was performed using four different packages.

RESULTS

Seventy-nine compounds reported in the literature with inhibitory effects on SARS-CoV proteins were reported as anti-inflammatory agents. Fourteen of them showed in previous studies immunomodulatory effects. Five and six of these compounds showed significant in silico consensus as drug candidates that can inhibit PL^pro and 3CL^pro, respectively. Our findings corroborated recent results reported on anti-SARS-CoV-2 in the literature.

CONCLUSION

This study revealed that amentoflavone, rubranoside B, savinin, psoralidin, hirsutenone, and papyriflavonol A are good drug candidate for the search of antibiotics against COVID-19.

Suppressive Effects of Rosmarinic Acid Rich Fraction from Perilla on Oxidative Stress, Inflammation and Metastasis Ability in A549 Cells Exposed to PM via C-Jun, P-65-Nf-Κb and Akt Signaling Pathways

Particulate matter from forest fires (PMFF) is an environmental pollutant causing oxidative stress, inflammation, and cancer cell metastasis due to the presence of polycyclic aromatic hydrocarbons (PAHs). Perilla seed meal contains high levels of polyphenols, including rosmarinic acid (RA). The aim of this study is to determine the anti-oxidative stress, anti-inflammation, and anti-metastasis actions of rosmarinic acid rich fraction (RA-RF) from perilla seed meal and its underlying molecular mechanisms in A549 cells exposed to PMFF. PMFF samples were collected via the air sampler at the University of Phayao, Thailand, and their PAH content were analyzed using GC-MS. Fifteen PAH compounds were detected in PMFF. The PMFF significantly induced intracellular reactive oxygen species (ROS) production, the mRNA expression of pro-inflammatory cytokines, MMP-9 activity, invasion, migration, the overexpression of c-Jun and p-65-NF-κB, and Akt phosphorylation. Additionally, the RA-RF significantly reduced ROS production, IL-6, IL-8, TNF-α, and COX-2. RA-RF could also suppress MMP-9 activity, migration, invasion, and the phosphorylation activity of c-Jun, p-65-NF-κB, and Akt. Our findings revealed that RA-RF has antioxidant, anti-inflammatory, and anti-metastasis properties via c-Jun, p-65-NF-κB, and Akt signaling pathways. RA-RF may be further developed as an inhalation agent for the prevention of lung inflammation and cancer metastasis induced by PM exposure.

rhKGF-2 Attenuates Smoke Inhalation Lung Injury of Rats via Activating PI3K/Akt/Nrf2 and Repressing FoxO1-NLRP3 Inflammasome

Smoke inhalation injury is an acute pathological change caused by thermal stimulation or toxic substance absorption through respiratory epithelial cells. This study aims to probe the protective effect and mechanism of recombinant human keratinocyte growth factor 2 (rhKGF-2) against smoke inhalation-induced lung injury (SILI) in rats. The SILI was induced in rats using a smoke exposure model, which were then treated with rhKGF-2. The rat blood was collected for blood-gas analysis, and the levels of inflammatory factors and oxidative stress markers in the plasma were measured. The rat lung tissues were collected. The pathological changes and cell apoptosis were determined by hematoxylin-eosin (HE) staining and TdT-mediated dUTP nick end labeling (TUNEL) assay, and the PI3K/Akt/Nrf2/HO-1/NQO1, and FoxO1-NLRP3 inflammasome expression were verified by western blot (WB). Both of the human alveolar epithelial cell (HPAEpiC) and primary rat alveolar epithelial cell were exposed to lipopolysaccharide (LPS) for making in-vitro alveolar epithelial cell injury model. After treatment with rhKGF-2, GSK2126458 (PI3K inhibitor) and AS1842856 (FoxO1 inhibitor), the cell viability, apoptosis, inflammation, oxidative stress, reactive oxygen species (ROS), PI3K/Akt/Nrf2, HO-1/NQO1, and FoxO1-NLRP3 in HPAEpiC and primary rat alveolar epithelial cell were examined. The data suggested that rhKGF-2 reduced LPS-induced HPAEpiC cell and primary rat alveolar epithelial cell apoptosis and the expression of inflammatory factors and oxidative stress factors. Moreover, rhKGF-2 improved the blood gas and alleviated SILI-induced lung histopathological injury in vivo via repressing inflammation, NLRP3 inflammasome activation and oxidative stress. Mechanistically, rhKGF-2 activated PI3K/Akt pathway, enhanced Nrf2/HO-1/NQO1 expression, and attenuated FoxO1-NLRP3 inflammasome both in vitro and in vivo. However, pharmaceutical inhibition of PI3K/Akt pathway attenuated rhKGF-2-mediated protective effects against SILI, while suppressing FoxO1 promoted rhKGF-2-mediated protective effects. Taken together, this study demonstrated that rhKGF-2 mitigated SILI by regulating the PI3K/Akt/Nrf2 pathway and the FoxO1-NLRP3 axis, which provides new reference in treating SILI.

Exposure Effects Beyond the Epithelial Barrier: Transepithelial Induction of Oxidative Stress by Diesel Exhaust Particulates in Lung Fibroblasts in an Organotypic Human Airway Model

In vitro bronchial epithelial monoculture models have been pivotal in defining the adverse effects of inhaled toxicant exposures; however, they are only representative of one cellular compartment and may not accurately reflect the effects of exposures on other cell types. Lung fibroblasts exist immediately beneath the bronchial epithelial barrier and play a central role in lung structure and function, as well as disease development and progression. We tested the hypothesis that in vitro exposure of a human bronchial epithelial cell barrier to the model oxidant diesel exhaust particulates caused transepithelial oxidative stress in the underlying lung fibroblasts using a human bronchial epithelial cell and lung fibroblast coculture model. We observed that diesel exhaust particulates caused transepithelial oxidative stress in underlying lung fibroblasts as indicated by intracellular accumulation of the reactive oxygen species hydrogen peroxide, oxidation of the cellular antioxidant glutathione, activation of NRF2, and induction of oxidative stress-responsive genes. Further, targeted antioxidant treatment of lung fibroblasts partially mitigated the oxidative stress response gene expression in adjacent human bronchial epithelial cells during diesel exhaust particulate exposure. This indicates that exposure-induced oxidative stress in the airway extends beyond the bronchial epithelial barrier and that lung fibroblasts are both a target and a mediator of the adverse effects of inhaled chemical exposures despite being separated from the inhaled material by an epithelial barrier. These findings illustrate the value of coculture models and suggest that transepithelial exposure effects should be considered in inhalation toxicology research and testing.

Associations of fine particulate matter and constituents with pediatric emergency room visits for respiratory diseases in Shanghai, China

BACKGROUND

Although ambient fine particulate matter (PM_2.5) has been associated with adverse respiratory outcomes in children, few studies have examined PM_2.5 constituents with respiratory diseases in children in China.

OBJECTIVES

To investigate the associations of short-term exposure to PM_2.5 and its constituents with pediatric emergency room visits (ERVs) for respiratory diseases in Shanghai, China.

METHODS

We collected daily concentrations of PM_2.5 and its constituents in urban Shanghai from January 1, 2016, to December 31, 2018. Daily pediatric ERVs for four major respiratory diseases, including upper respiratory tract infection, bronchitis, pneumonia, and asthma, were obtained from 66 hospitals in Shanghai during the same period. Associations of exposure to daily PM_2.5 and constituents with respiratory ERVs were estimated using the over-dispersed generalized additive models.

RESULT

Short-term exposure to PM_2.5 and its constituents were associated with increased pediatric ERVs for respiratory diseases. Specifically, an interquartile range increase in the 3-day average PM_2.5 level (31 μg/m³) was associated with 1.86% (95%CI: 0.52, 3.22), 1.53% (95%CI: 0.01, 3.08), 1.90% (95%CI: 0.30, 3.52), and 2.67% (95%CI: 0.70, 4.68) increase of upper respiratory tract infection, bronchitis, pneumonia, and asthma ERVs, respectively. As for PM_2.5 constituents, we found organic carbon, ammonium, nitrate, selenium, and zinc were associated with higher risk of respiratory ERVs in the single constituent and the constituent-PM_2.5 models.

CONCLUSION

Short-term exposure to PM_2.5 was associated with increased pediatric ERVs for respiratory diseases. Constituents related to anthropogenic combustion and traffic might be the dominant contributors of the observed associations.

Comparison of COVID-19 and Lung Cancer via Reactive Oxygen Species Signaling

COVID-19 and lung cancer are two severe pulmonary diseases that cause millions of deaths globally each year. Understanding the dysregulated signaling pathways between them can benefit treating the related patients. Recent studies suggest the critical role of reactive oxygen species (ROS) in both diseases, indicating an interplay between them. Here we reviewed references showing that ROS and ROS-associated signaling pathways, specifically via NRF2, HIF-1, and Nf-κB pathways, may bridge mutual impact between COVID-19 and lung cancer. As expected, typical ROS-associated inflammation pathways (HIF-1 and Nf-κB) are activated in both diseases. The activation of both pathways in immune cells leads to an overloading immune response and exacerbates inflammation in COVID-19. In lung cancer, HIF-1 activation facilitates immune escape, while Nf-κB activation in T cells suppresses tumor growth. However, the altered NRF2 pathway show opposite trends between them, NRF2 pathways exert immunosuppressive effects in both diseases, as it represses the immune response in COVID-19 patients while facilitates the immune escape of tumor cells. Furthermore, we summarized the therapeutic targets (e.g., phytochemicals) on these ROS pathways. In sum, our review focus on the understanding of ROS Signaling in COVID-19 and lung cancer, showing that modulating ROS signaling pathways may alleviate the potentially mutual impacts between COVID-19 and lung cancer patients.

Associations between Residential Proximity to Oil and Gas Drilling and Term Birth Weight and Small-for-Gestational-Age Infants in Texas: A Difference-in-Differences Analysis

BACKGROUND

Oil and natural gas extraction may produce environmental pollution at levels that affect reproductive health of nearby populations. Available studies have primarily focused on unconventional gas drilling and have not accounted for local population changes that can coincide with drilling activity.

OBJECTIVE

Our study sought to examine associations between residential proximity to oil and gas drilling and adverse term birth outcomes using a difference-in-differences study design.

METHODS

We created a retrospective population-based term birth cohort in Texas between 1996 and 2009 composed of mother-infant dyads (n=2,598,025) living <10km from an oil or gas site. We implemented a difference-in-differences approach to estimate associations between drilling activities and infant health: term birth weight and term small for gestational age (SGA). Using linear and logistic regression, we modeled interactions between births before (unexposed) or during (exposed) drilling activity and residential proximity near (0-1, 1-2, or 2-3km) or far (3-10km) from an active or future drilling site, adjusting for individual- and neighborhood-level characteristics.

RESULTS

The adjusted mean difference in term birth weight for mothers living 0-1 vs. 3-10km from a current or future drilling site was -7.3g [95% confidence interval (CI): -11.6, -3.0] for births during active vs. future drilling. The corresponding adjusted odds ratio for SGA was 1.02 (95% CI: 0.98, 1.06). Negative associations with term birth weight were observed for the 1-2 and 2-3km near groups, and no consistent differences were identified by type of drilling activity. Larger, though imprecise, adverse associations were found for infants born to Hispanic women, women with the lowest educational attainment, and women living in cities.

CONCLUSIONS

Residing near oil and gas drilling sites during pregnancy was associated with a small reduction in term birth weight but not SGA, with some evidence of environmental injustices. Additional work is needed to investigate specific drilling-related exposures that might explain these associations. https://doi.org/10.1289/EHP7678.

AQP3-mediated H2 O2 uptake inhibits LUAD autophagy by inactivating PTEN

It is widely accepted that redox reprogramming participates in malignant transformation of lung adenocarcinoma (LUAD). However, the source of excessive reactive oxygen species (ROS) and the downstream signaling regulatory mechanism are complicated and unintelligible. In the current study, we newly identified the aquaporin 3 (AQP3) as a LUAD oncogenic factor with capacity to transport exogenous hydrogen peroxide (H₂ O₂ ) and increase intracellular ROS levels. Subsequently, we demonstrated that AQP3 was necessary for the facilitated diffusion of exogenous H₂ O₂ in LUAD cells and that the AQP3-dependent transport of H₂ O₂ accelerated cell growth and inhibited rapamycin-induced autophagy. Mechanistically, AQP3-mediated H₂ O₂ uptake increased intracellular ROS levels to inactivate PTEN and activate the AKT/mTOR pathway to subsequently inhibit autophagy and promote proliferation in LUAD cells. Finally, we suggested that AQP3 depletion retarded subcutaneous tumorigenesis in vivo and simultaneously decreased ROS levels and promoted autophagy. These findings underscore the importance of AQP3-induced oxidative stress in malignant transformation and suggest a therapeutic target for LUAD.

Lung cancer in the older population:Interactive effects of angiotensin converting enzyme gene polymorphism (rs 4340 ID) and tobacco addiction in risk assessment

BACKGROUND

rs4340ID polymorphism of angiotensin-converting enzyme (ACE) correlates with serum ACE levels in many known cancers. This study analyzed ACE rs4340 ID polymorphism in lung cancer (LC) in older patients of North India and correlated it with addiction status.

METHODS

The study enrolled all subjects aged 60 years and above with 154 LC and 205 healthy controls. Genotyping was done by polymerase chain reaction (PCR) and validated by sequencing of 10% of the sample. Statistical analysis was done by SPSS Statistics 21.

RESULTS

Genotype II was observed to have a significant 2.21-fold increased risk of LC as compared to the DD genotype and 3.43-folds enhanced risk with interaction of I allele with tobacco consumption habits as compared to D allele in LC was seen.

CONCLUSION

The risk of LC was higher with II genotype as compared to DD genotype. Interactive effect showed that I allele with tobacco habits may increase the risk of LC.

Sulforaphane Alleviates Particulate Matter-Induced Oxidative Stress in Human Retinal Pigment Epithelial Cells

Age-related macular degeneration (AMD) is a leading cause of blindness in the elderly, and oxidative damage to retinal pigment epithelial (RPE) cells plays a major role in the pathogenesis of AMD. Exposure to high levels of atmospheric particulate matter (PM) with an aerodynamic diameter of <2.5 μm (PM2.5) causes respiratory injury, primarily due to oxidative stress. Recently, a large community-based cohort study in the UK reported a positive correlation between PM2.5 exposure and AMD. Sulforaphane (SFN), a natural isothiocyanate found in cruciferous vegetables, has known antioxidant effects. However, the protective effects of SNF in the eye, especially in the context of AMD, have not been evaluated. In the present study, we evaluated the effect of SFN against PM2.5-induced toxicity in human RPE cells (ARPE-19) and elucidated the molecular mechanism of action. Exposure to PM2.5 decreased cell viability in ARPE-19 cells in a time- and dose-dependent manner, potentially due to elevated intracellular reactive oxygen species (ROS). SFN treatment increased ARPE-19 cell viability and decreased PM2.5-induced oxidative stress in a dose-dependent manner. PM2.5-induced downregulation of serum- and glucocorticoid-inducible kinase 1 (SGK1), a cell survival factor, was recovered by SFN. PM2.5 treatment decreased the enzymatic activities of the antioxidant enzymes including superoxide dismutase and catalase, which were restored by SFN treatment. Taken together, these findings suggest that SFN effectively alleviates PM2.5-induced oxidative damage in human ARPE-19 cells via its antioxidant effects, and that SFN can potentially be used as a therapeutic agent for AMD, particularly in cases related to PM2.5 exposure.

Pollution, Inflammation, and Vaccines: A Complex Crosstalk

The importance of pollution in determining human health is becoming increasingly clear, also given the dramatic consequences it has had on recent geopolitical events. Yet, the consequences of contamination are not always straightforward. In this paper, we will discuss the effects of different pollutants on different aspects of human health, in particular on the immune system and inflammation. Different environmental pollutants can have different effects on the immune system, which can then promote complex pathologies, such as autoimmune disorders and cancer. The interaction with the microbiota also further helps to determine the consequences of contamination on wellbeing. The pollution can affect vaccination efficacy, given the widespread effects of vaccination on immunity. At the same time, some vaccinations also can exert protective effects against some forms of pollution.

Why We Will Continue to Lose Our Battle with Cancers If We Do Not Stop Their Triggers from Environmental Pollution

Besides our current health concerns due to COVID-19, cancer is a longer-lasting and even more dramatic pandemic that affects almost a third of the human population worldwide. Most of the emphasis on its causes has been posed on genetic predisposition, chance, and wrong lifestyles (mainly, obesity and smoking). Moreover, our medical weapons against cancers have not improved too much during the last century, although research is in progress. Once diagnosed with a malignant tumour, we still rely on surgery, radiotherapy, and chemotherapy. The main problem is that we have focused on fighting a difficult battle instead of preventing it by controlling its triggers. Quite the opposite, our knowledge of the links between environmental pollution and cancer has surged from the 1980s. Carcinogens in water, air, and soil have continued to accumulate disproportionally and grow in number and dose, bringing us to today's carnage. Here, a synthesis and critical review of the state of the knowledge of the links between cancer and environmental pollution in the three environmental compartments is provided, research gaps are briefly discussed, and some future directions are indicated. New evidence suggests that it is relevant to take into account not only the dose but also the time when we are exposed to carcinogens. The review ends by stressing that more dedication should be put into studying the environmental causes of cancers to prevent and avoid curing them, that the precautionary approach towards environmental pollutants must be much more reactionary, and that there is an urgent need to leave behind the outdated petrochemical-based industry and goods production.

NADPH Oxidases (NOX): An Overview from Discovery, Molecular Mechanisms to Physiology and Pathology

The reactive oxygen species (ROS)-producing enzyme NADPH oxidase (NOX) was first identified in the membrane of phagocytic cells. For many years, its only known role was in immune defense, where its ROS production leads to the destruction of pathogens by the immune cells. NOX from phagocytes catalyzes, via one-electron trans-membrane transfer to molecular oxygen, the production of the superoxide anion. Over the years, six human homologs of the catalytic subunit of the phagocyte NADPH oxidase were found: NOX1, NOX3, NOX4, NOX5, DUOX1, and DUOX2. Together with the NOX2/gp91phox component present in the phagocyte NADPH oxidase assembly itself, the homologs are now referred to as the NOX family of NADPH oxidases. NOX are complex multidomain proteins with varying requirements for assembly with combinations of other proteins for activity. The recent structural insights acquired on both prokaryotic and eukaryotic NOX open new perspectives for the understanding of the molecular mechanisms inherent to NOX regulation and ROS production (superoxide or hydrogen peroxide). This new structural information will certainly inform new investigations of human disease. As specialized ROS producers, NOX enzymes participate in numerous crucial physiological processes, including host defense, the post-translational processing of proteins, cellular signaling, regulation of gene expression, and cell differentiation. These diversities of physiological context will be discussed in this review. We also discuss NOX misregulation, which can contribute to a wide range of severe pathologies, such as atherosclerosis, hypertension, diabetic nephropathy, lung fibrosis, cancer, or neurodegenerative diseases, giving this family of membrane proteins a strong therapeutic interest.

Regulatory Action of all trans Retinoic Acid on Metastasis Induced lung Cell Metabolic Changes during Implantation of B16F10 Cancer Cells in C57BL6 Mice

The changes that occur during metastasis lodging is under intense research now to develop preventive new drugs to fight against the deadly metastasis. The molecular drug, all trans Retinoic Acid (ATRA) has regulatory effects on signal mediated metabolism. In this study, we have analyzed the metastasis facilitating metabolic changes in mice lung when a highly metastatic melanoma cell line (B16F10) having potency to lodge in lung was implanted via tail vein injection into C57BL/6 mice (1×106 cells/ml in PBS). One group of implanted mice were treated with 0.60 mg of ATRA per Kg body weight daily for 21 days. The alteration of protein, enzymatic and non-enzymatic antioxidants (SOD, Catalase, GPX, GSH) levels and the lipid profile with cholesterol level were evaluated in the lung tissues. The ATRA treatment caused 62.16% inhibition on metastatic nodule formation. Compared to normal mice, the cancer control mice showed an increased (p≤ 0.01**) total protein, LPO and NO and a decreased antioxidant. In ATRA treated group, all these levels were reverted to near normal levels with a high significance (p≤ 0.01**) difference from untreated cancer mice. The lipid profile and cholesterol level also were altered in cancer and were normalized in ATRA treated group with high significance (p≤ 0.01**). All these results implies that the metabolic changes induced in the lung tissue during metastatic lodging of melanoma cells were prevented and regularized by the ATRA treatment in vivo which give a scope of anti-metastatic therapy using ATRA.

Caspase-11 and AIM2 inflammasome are involved in smoking-induced COPD and lung adenocarcinoma

Cigarette smoking is the leading risk factor for COPD and lung cancer establishment. Epidemiologically, COPD patients are 6.35 times more likely to develop lung cancer. To mimic COPD, we exposed mice to nose-only cigarette smoke and used human samples of lung adenocarcinoma patients according to the smoking and COPD status. Smoking C57Bl/6N mice had higher enlargement of alveoli, deposition of collagen and mucus production, associated to the release of IL-1-like cytokines, such as IL-1α and IL-1β at early time points and IL-18 at later time points. AIM2 expression was higher in lung recruited dendritic cells and macrophages in smoking mice, associated to the activation of caspase-11, rather than caspase-1. In support,129Sv mice, which are dysfunctional for caspase-11, had lower collagen deposition and mucus production, associated to lower release of IL-1-like and fibrotic TGFβ. Interestingly, higher expression of AIM2 in non-cancerous tissue of smoking COPD adenocarcinoma patients was correlated to a higher hazard ratio of poor survival rate than in patients who presented lower levels of AIM2. We found that AIM2 inflammasome is at the crossroad between COPD and lung cancer in that its higher presence is correlated to lower survival rate of smoking COPD adenocarcinoma patients.

The Role of Tumor Inflammatory Microenvironment in Lung Cancer

Lung cancer is the most common and fatal malignant tumor in the world. The tumor microenvironment (TME) is closely related to the occurrence and development of lung cancer, in which the inflammatory microenvironment plays an important role. Inflammatory cells and inflammatory factors in the tumor inflammatory microenvironment promote the activation of the NF-κB and STAT3 inflammatory pathways and the occurrence, development, and metastasis of lung cancer by promoting immune escape, tumor angiogenesis, epithelial-mesenchymal transition, apoptosis, and other mechanisms. Clinical and epidemiological studies have also shown a strong relationship among chronic infection, inflammation, inflammatory microenvironment, and lung cancer. The relationship between inflammation and lung cancer can be better understood through the gradual understanding of the tumor inflammatory microenvironment, which is advantageous to find more therapeutic targets for lung cancer.

Particulate Matter, an Intrauterine Toxin Affecting Foetal Development and Beyond

Air pollution is the 9th cause of the overall disease burden globally. The solid component in the polluted air, particulate matters (PMs) with a diameter of 2.5 μm or smaller (PM_2.5) possess a significant health risk to several organ systems. PM_2.5 has also been shown to cross the blood–placental barrier and circulate in foetal blood. Therefore, it is considered an intrauterine environmental toxin. Exposure to PM_2.5 during the perinatal period, when the foetus is particularly susceptible to developmental defects, has been shown to reduce birth weight and cause preterm birth, with an increase in adult disease susceptibility in the offspring. However, few studies have thoroughly studied the health outcome of foetuses due to intrauterine exposure and the underlying mechanisms. This perspective summarises currently available evidence, which suggests that intrauterine exposure to PM_2.5 promotes oxidative stress and inflammation in a similar manner as occurs in response to direct PM exposure. Oxidative stress and inflammation are likely to be the common mechanisms underlying the dysfunction of multiple systems, offering potential targets for preventative strategies in pregnant mothers for an optimal foetal outcome.

Chemopreventive effect of dieckol against 7,12-dimethylbenz(a)anthracene induced skin carcinogenesis model by modulatory influence on biochemical and antioxidant biomarkers

Skin cancer is the commonly found type, which contributes to 40% of whole cancer incidences worldwide. Dieckol is an active compound occurs in the marine algae with many biological benefits. In this exploration, we intended to investigate the therapeutic potency of dieckol against the 7,12-dimethylbenz(a)anthracene (DMBA)-triggered skin carcinogenesis in mice. The skin cancer was stimulated to the animals via injecting the 25 μg of DMBA in 100 μL of acetone in shaved dorsal portion along with the 30 mg/kg of dieckol supplementation for 25 week. The antioxidant enzymes and phase-I and -II detoxifying enzymes in the test animals were inspected via standard protocols. Pro-inflammatory markers (IL-6, IL-1β, and TNF-α) level was examined via ELISA kits and the expression of inflammatory molecular markers like p-NF-ƙB, IƙBα and p-IƙBα were studied through western blotting. The expression status of pro- and anti-apoptotic proteins (p53, Bax, Bcl-2, caspase-3, caspase-9, COX-2, TGF-β1) was investigated via real-time polymerase chain reaction (RT-PCR). Our results revealed that the 30 mg/kg of dieckol supplementation noticeably regained the body and liver weight and also diminished the tumor incidence in the DMBA-incited animals. Dieckol treatment exhibited an enhanced antioxidants (SOD, CAT, GPx, and GSH) and reduced phase-I enzymes Cyt-p450 and Cyt-b5 in the DMBA-induced animals. Dieckol also diminished the pro-inflammatory modulators like IL-6, IL-1β and TNF-α. Western blotting result evidenced that the dieckol was inhibited the IƙB/NF-ƙB signaling pathway. RT-PCR study proved the enhanced expression of pro-apoptotic protein (p53, Bax, caspase-3 and -9) in the dieckol treated animals. Histological study also confirmed the therapeutic benefits of Dieckol. Altogether with these findings, it was clear that the dieckol has appreciably allayed the DMBA activated skin tumorigenesis in the mice and it could be a promising agent to treat the human skin cancer in future.

Hyperoside relieves particulate matter-induced lung injury by inhibiting AMPK/mTOR-mediated autophagy deregulation

Autophagy-mediated cell death plays a critical role in the pathogenesis of PMs-induced lung injury. Hyperoside (Hyp), a flavonoid glycosides, is known to exert protective effects on many diseases by inhibiting autophagic activity. The current study aimed to explore the protective effect and mechanism of Hyp against PMs-induced lung injury in PM2.5 challenged Beas-2b cells in vitro and BALB/C mice in vivo. In vitro, we found that the organic solvent-extractable fraction of SRM1649b (O-PMs) caused more severe cytotoxicity in Beas-2b cells than the water solvent-extractable fraction of SRM1649b (W-PMs). O-PMs treatment dose-dependently upregulated the expression of autophagy markers (beclin-1, p62, atg3 and LC3II) and apoptotic proteins. This cytotoxicity of O-PMs was attenuated by Hyp pretreatment in parallel with downregulation of the expression of autophagy markers, apoptotic proteins, and p-AMPK and upregulation of p-mTOR expression. Notably, the therapeutic effect of Hyp was attenuated by pretreated with AICAR (an AMPK inducer), but enhanced by CC and 3-MA treatment. In vivo, Hyp reduced pathological lung injury and decreased the levels of PMs-induced inflammatory cytokines (TNF-α and IL-6), and the number of total cells in the BALF by inhibiting AMPK/mTOR signaling. Furthermore, cotreatment with AICAR (500 mg/kg) reduced but did not abrogate the pulmonary protective effect of Hyp. These findings indicate that Hyp protects against PMs-induced lung injury by suppressing autophagy deregulation and apoptosis through regulation of the AMPK/mTOR pathway.

Ambient air pollutant exposure and in vitro fertilization treatment outcomes in Zhengzhou, China

OBJECTIVE

To study the association between ambient air pollutant exposure during the follicular phase and in vitro fertilization (IVF) outcomes.

DESIGN

A single-center retrospective analysis.

SETTING

Henan Province, China.

PATIENTS

Patients (n = 6659) living in Zhengzhou, Henan Province in central China who underwent their first IVF cycle at the First Affiliated Hospital of Zhengzhou University between 2013 and 2019 were included for analysis.

INTERVENTION

None.

MAIN OUTCOME MEASURE

The relationships between PM_2.5, PM₁₀, and AQI (Air Quality Index) with IVF outcomes during the follicular phase (period I, 85 days before oocyte retrieval; period II, gonadotrophin start to oocyte retrieval).

RESULTS

Compared with the bottom tertile, exposure to the top PM_2.5 and PM₁₀ tertiles during period I was associated with decreased clinical pregnancy (PM_2.5: adjusted odds ratio [OR], 0.838%, and 95% confidence interval [CI], 0.723 and 0.971; PM₁₀: adjusted OR, 0.818%, and 95% CI, 0.705 and 0.950), and decreased live birth rate (PM_2.5: adjusted odds ratio [OR], 0.852%, and 95% confidence interval [CI], 0.736 and 0.987; PM₁₀: adjusted OR, 0.850%, and 95% CI, 0.733 and 0.986), and exposure to the top PM_2.5 tertile during period II adversely affected clinical pregnancy and the live birth rate (adjusted OR, 0.824%, and 95% CI, 0.711 and 0.955; adjusted OR, 0.817%, and 95% CI, 0.706 and 0.945). Compared with the bottom PM₁₀ tertile, exposure to the middle PM₁₀ tertile in period II showed decreased clinical pregnancies and live births (adjusted OR, 0.844; 95% CI, 0.729 and 0.978, adjusted OR, 0.846; 95% CI, 0.731 and 0.979). The PM₁₀ level during period II of the follicular phase tend to adversely affect live birth rate, but the tendency did not reach significance (P = 0.051).

CONCLUSION

Exposure to PM_2.5 and PM₁₀ before oocyte retrieval has an adverse effect on IVF outcomes.

CAPSULE

Exposure to PM_2.5 and PM₁₀ before oocyte retrieval has an adverse effect on IVF outcomes.

Protective effect of anisodamine on bleomycin-induced acute lung injury in immature rats via modulating oxidative stress, inflammation, and cell apoptosis by inhibiting the JAK2/STAT3 pathway

Background

Pediatric acute lung injury (ALI) is one of the most common causes of infant mortality. Although lung-protective strategies have developed in recent years, no ALI treatment is currently available. Anisodamine (Ani) is a common drug used to treat gastrointestinal smooth muscle spasm. The protective effects of Ani against acute kidney injury and myocardial injury have been reported. However, the efficacy of Ani on bleomycin (BLM)-induced ALI has not been examined previously. In the present study, we aimed to examine the effects of Ani on bleomycin (BLM)-induced ALI on immature rats.

Methods

The ALI rat model was established by intratracheally administration of BLM. Ani treatment was performed by an intravenous injection at different concentrations. The lung function of each rat was measured, and then lung tissue structures, apoptosis, and collagen deposition were observed by hematoxylin-eosin staining, terminal deoxynucleotidyl transferase-mediated digoxigenin-dUTP nick-end labeling assay, and Masson’s staining, respectively. Enzyme-linked immunosorbent assay was used to detect the levels of inflammatory cytokines. The expression of apoptosis-related proteins and fibrosis-related markers was determined by reverse transcription-polymerase chain reaction and/or Western blot analysis. Finally, the expression levels of Janus tyrosine kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3) were determined.

Results

Our findings indicated that lung function was remarkably decreased in BLM-induced rats, which could be reversed by Ani. Ani treatment increased the levels of antioxidant enzymes, decreased the apoptotic rate and apoptosis-related proteins, and downregulated the expression of fibrosis-related markers. Additionally, Ani treatment also attenuated inflammatory response and suppressed the activation of the JAK2/STAT3 pathway.

Conclusions

Our results demonstrated that Ani had potent activity against BLM-induced ALI in immature rats through inhibiting the JAK2/STAT3 signaling pathway. Our findings provide supporting evidence to further investigate the therapeutic effect of Ani against ALI in children.

Associations of Variability in Metabolic Parameters with Lung Cancer: A Nationwide Population-Based Study

Simple Summary

Lung cancer is currently the most common cancer worldwide. This study investigates whether visit-to-visit variability in metabolic parameters is associated with lung cancer risk. We found that a high variability in fasting blood glucose, systolic blood pressure, total cholesterol, and body weight were each associated with increased risk of lung cancer. A higher number of high-variability parameters were also associated with increased lung cancer risk. Further research is needed to examine whether reducing variability can lead to decreased lung cancer risk.

Abstract

We investigated whether visit-to-visit variability in metabolic parameters is associated with lung cancer risk. We used nationally representative data from the Korean National Health Insurance System, and 8,011,209 lung-cancer-free subjects who underwent over three health examinations from 2005 to 2010 were followed until 2017. Variability of fasting blood glucose, total cholesterol, systolic blood pressure, and body weight were measured by the variability independent of the mean, assessed by quartiles. There were 44,982 lung cancer events. The hazard ratio (HR) and 95% confidence interval (CI) for lung cancer risk was 1.07 (1.04, 1.10) for fasting blood glucose in the highest quartile, 1.08 (1.05, 1.10) for systolic blood pressure, 1.04 (1.01, 1.07) for weight, and 1.11 (1.08, 1.14) for total cholesterol. When comparing ≥3 vs. 0 high-variability metabolic parameters, the HR for lung cancer was 1.18 (95% CI, 1.14, 1.22). However, while ≥3 high-variability parameters showed an increased lung cancer risk in men (HR 1.26, 95% CI 1.21, 1.31), women did not show increased risk (HR 0.99, 95% CI 0.92, 1.06). High variability in each metabolic parameter, and a higher number of high-variability parameters, were associated with increased lung cancer risk.

Prognostic utility of pretreatment neutrophil-lymphocyte ratio in survival outcomes in localized non-small cell lung cancer patients treated with stereotactic body radiotherapy: Selection of an ideal clinical cutoff point

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Neutrophil-lymphocyte ratio is a promising prognostic marker for several cancers.

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NLR is not useful as a marker of lung cancer survival in localized lung cancer.

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NLR has potential as a marker of competing mortality risk in localized lung cancer.

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NLR cutoff of 4.0 is proposed as a clinically useful cutoff point.

Background and purpose

Neutrophil-lymphocyte ratio (NLR) has been associated with overall survival (OS) in non-small cell lung cancer (NSCLC). We aimed to assess the utility of NLR as a predictor of lung cancer-specific survival (LCS) and identify an optimal, pretreatment cutoff point in patients with localized NSCLC treated with stereotactic body radiotherapy (SBRT) within the Veterans Affairs’ (VA) national database.

Materials and methods

In the VA database, we identified patients with biopsy-proven, clinical stage I NSCLC treated with SBRT between 2006 and 2015. Cutoff points for NLR were calculated using Contal/O’Quigley’s and Cox Wald methods. Primary outcomes of OS, LCS, and non-lung cancer survival (NCS) were evaluated in Cox and Fine-Gray models.

Results

In 389 patients, optimal NLR cutoff was identified as 4.0. In multivariable models, NLR > 4.0 was associated with decreased OS (HR 1.44, p = 0.01) and NCS (HR 1.68, p = 0.01) but not with LCS (HR 1.32, p = 0.09). In a subset analysis of 229 patients with pulmonary function tests, NLR > 4.0 remained associated with worse OS (HR 1.51, p = 0.02) and NCS (HR 2.18, p = 0.01) while the association with LCS decreased further (HR 1.22, p = 0.39).

Conclusion

NLR was associated with worse OS in patients with localized NSCLC treated with SBRT; however, NLR was only associated with NCS and not with LCS. Pretreatment NLR, with a cutoff of 4.0, offers potential as a marker of competing mortality risk which can aid in risk stratification in this typically frail and comorbid population. Further studies are needed to validate pretreatment NLR as a clinical tool in this setting.

Air pollution exposure-the (in)visible risk factor for respiratory diseases

There is increasing interest in understanding the role of air pollution as one of the greatest threats to human health worldwide. Nine of 10 individuals breathe air with polluted compounds that have a great impact on lung tissue. The nature of the relationship is complex, and new or updated data are constantly being reported in the literature. The goal of our review was to summarize the most important air pollutants and their impact on the main respiratory diseases (chronic obstructive pulmonary disease, asthma, lung cancer, idiopathic pulmonary fibrosis, respiratory infections, bronchiectasis, tuberculosis) to reduce both short- and the long-term exposure consequences. We considered the most important air pollutants, including sulfur dioxide, nitrogen dioxide, carbon monoxide, volatile organic compounds, ozone, particulate matter and biomass smoke, and observed their impact on pulmonary pathologies. We focused on respiratory pathologies, because air pollution potentiates the increase in respiratory diseases, and the evidence that air pollutants have a detrimental effect is growing. It is imperative to constantly improve policy initiatives on air quality in both high- and low-income countries.

Acute ozone exposure can cause cardiotoxicity: Mitochondria play an important role in mediating myocardial apoptosis

OBJECTIVE

To clarify the cardiotoxicity induced by acute exposure to different concentrations of ozone in both gender rats and explore the underlying mechanisms.

METHODS

A total of 240 rats were randomly sorted into 6 groups with equal numbers of male and female rats in each group. The rats were subjected to ozone inhalation at concentrations of 0, 0.12, 0.5, 1.0, 2.0 and 4.0 ppm, respectively, for 6 h. After ozone exposure, function indicators, myocardial injury indexes and risk factors of cardiovascular disease in blood were assayed.

RESULTS

High ozone exposure resulted in sustained ventricular tachycardia in male and female rats. Myocardial apoptosis in male rats started from 1.0 ppm ozone, and that in female rats started from 2.0 ppm ozone (p < 0.05). Caspase-9 increased significantly from 0.12 ppm ozone (p < 0.01) in both gender rats, while caspase-3 was initially activated at 0.5 ppm ozone. From 1.0 ppm ozone, mitochondrial cristae and myofilaments dissolved. The ratio of Bcl-2/Bax decreased significantly from 0.12 ppm and MRCC-IV decreased significantly from 2.0 ppm by ozone.

CONCLUSION

Acute ozone exposure can cause paroxysmal ventricular tachycardia in rats. Moreover, the changes of inflammatory factors in the heart tissues of female and male rats after ozone exposure were greater than those of oxidative stress. This study reported for the first time that 6 h ozone exposure does not cause acute cardiomyocyte necrosis, but promotes cardiomyocyte apoptosis in a mitochondrial-dependent manner. Ozone could regulate caspases-3 dependent cardiomyocyte apoptosis by affecting the balance between caspase-9 and XIAP.

Comparison of therapeutic effects between topical 8-oxo-2'-deoxyguanosine and corticosteroid in ocular alkali burn model

We compared the therapeutic effects of topical 8-oxo-2'-deoxyguanosine (8-oxo-dG) and corticosteroid in a murine ocular alkali burn model. (n = 128) The corneal alkali burn model was established by applying 0.1 N sodium hydroxide (NaOH), followed by treatment with 8-oxo-dG, 0.1% fluorometholone (FML), 1% prednisolone acetate (PDE), or phosphate-buffered saline (PBS) twice daily. One week later, the clinical and histological status of the cornea were assessed. Transcript levels of inflammatory cytokines and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase as well as the levels of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in the cornea, were assayed. The 8-oxo-dG and PDE groups showed marked improvements in corneal integrity and clarity when compared with the PBS group (each p < 0.01). The numbers of cells stained for neutrophil elastase and F4/80-positive inflammatory cells were significantly decreased, with levels of interleukin(IL)-1β, IL-6, tumor necrosis factor(TNF)-α, and total ROS/RNS amounts markedly reduced in the 8-oxo-dG, FML, and PDE groups (each p < 0.05). Levels of NADPH oxidase type 2 and 4 were substantially more repressed in the 8-oxo-dG-treated group than in the PDE-treated group (each p < 0.05). Topical 8-oxo-dG showed excellent therapeutic effects that were comparable with those treated with topical PDE in a murine ocular alkali burn model.

Newly Emerging Airborne Pollutants: Current Knowledge of Health Impact of Micro and Nanoplastics

Plastics are ubiquitous persistent pollutants, forming the most representative material of the Anthropocene. In the environment, they undergo wear and tear (i.e., mechanical fragmentation, and slow photo and thermo-oxidative degradation) forming secondary microplastics (MPs). Further fragmentation of primary and secondary MPs results in nanoplastics (NPs). To assess potential health damage due to human exposure to airborne MPs and NPs, we summarize the evidence collected to date that, however, has almost completely focused on monitoring and the effects of airborne MPs. Only in vivo and in vitro studies have assessed the toxicity of NPs, and a standardized method for their analysis in environmental matrices is still missing. The main sources of indoor and outdoor exposure to these pollutants include synthetic textile fibers, rubber tires, upholstery and household furniture, and landfills. Although both MPs and NPs can reach the alveolar surface, the latter can pass into the bloodstream, overcoming the pulmonary epithelial barrier. Despite the low reactivity, the number of surface area atoms per unit mass is high in MPs and NPs, greatly enhancing the surface area for chemical reactions with bodily fluids and tissue in direct contact. This is proven in polyvinyl chloride (PVC) and flock workers, who are prone to persistent inflammatory stimulation, leading to pulmonary fibrosis or even carcinogenesis.

Exposure to volatile organic compounds may be associated with oxidative DNA damage-mediated childhood asthma

Volatile organic compounds (VOCs) are important and ubiquitous air pollutants, which may lead to a significant increase in the prevalence of respiratory diseases. To investigate the relationships between VOCs exposure and childhood asthma, 252 asthmatic children and 69 healthy children were recruited. Urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG, a biomarker of oxidative DNA damage), trans-3'-hydroxycotinine (OH-Cot, a biomarker of passive smoking) and 27 VOC metabolites were simultaneously determined by an ultra-high-performance liquid chromatography-tandem mass spectrometer. Results showed that levels of 8-OHdG and most VOC metabolites in asthmatic children were significantly higher than those in healthy children. More than half of the VOC metabolites were significantly and positively associated with OH-Cot with maximal β coefficient of 0.169, suggesting that second-hand smoking is one important source of VOCs exposure for children in Guangzhou. Significant dose-response relationships between most VOC metabolites and 8-OHdG were observed. Each unit increase in ln-transformed VOC metabolite levels was significantly associated with 5.5-32% increase in ln-transformed 8-OHdG level. Moreover, each unit increase in ln-transformed 8-OHdG level was associated with an 896% increased odd ratios (OR) of asthma in children (OR = 9.96, 95% confidence intervals (CI): 4.75, 20.9), indicating that oxidative stress induced by VOCs exposure may have a significant impact on childhood asthma. Urinary 3-&4-Methylhippuric acid (3-&4-MHA, OR: 5.78, 95% CI: 3.50, 9.54), rac 2-Aminothiazoline-4-carboxylic acid (ATCA, OR: 2.90, 95% CI: 1.69, 4.99) and N-Acetyl-S-(3,4-dihydroxybutyl)-L-cysteine (DHBMA, OR: 2.76, 95% CI: 1.73, 4.43) which may derive from m/p-xylene, cyanide and 1,3-butadiene exposure, respectively, could significantly and maximally increase the odds of asthma. Interestingly, they also had the strongest associations with 8-OHdG among all investigated VOC metabolites. Moreover, DHBMA strongly correlated with most VOC metabolites. Hence, DHBMA is a suitable biomarker to indicate not only VOCs exposure profile, but also the DNA damage-mediated asthma induced by VOCs.

Potential human health risks due to environmental exposure to nano- and microplastics and knowledge gaps: A scoping review

Microplastics are an emerging global environmental contaminant that are affecting multiple spheres. Despite their ubiquity in all spheres of life and ecology, little is known about the health effects of microplastics exposure to humans. This scoping review explores the existing evidence on the potential human health effects of microplastics and subsequent knowledge gaps. An electronic search of published articles in PubMed, Scopus, EMBASE, Cochrane databases, and Google Scholar was conducted using a combination of subject headings and keywords relating to microplastics and human health effects. The initial search resulted in 17,043 published articles and grey literature documents. After a full review of published articles and their references, 129 publications were identified for further detailed review. These articles indicate that human exposure to microplastics can occur through ingestion, inhalation, and dermal contact due to their presence in food, water, air, and consumer products. Microplastics exposure can cause toxicity through oxidative stress, inflammatory lesions, and increased uptake or translocation. Several studies have demonstrated the potentiality of metabolic disturbances, neurotoxicity, and increased cancer risk in humans. Moreover, microplastics have been found to release their constituent compounds as well as those that are adsorbed onto their surface. Further research is needed to quantify the effects of microplastics on human health and their pathogenesis.

Beneficial effects of combined administration of fluoxetine and mitochondria-targeted antioxidant at in behavioural and molecular studies in mice model of depression

Chronic or recurrent stress is associated with reactive oxygen species (ROS) overproduction and can lead to oxidative damage, which plays important roles in neurodegenerative diseases. Mito - TEMPO is an antioxidant targeted at mitochondria. The aim of the presented study was to assess antidepressant and antioxidant efficacy of Mito - TEMPO administered alone or with fluoxetine in mice exposed to chronic stress. The evaluation of the antidepressant-like activity was based on forced swimming test (FST) and tail suspension test (TST). In order to evaluate the antioxidant potential, the level of mRNA expression of Adora1, Ogg1, Msra, Nrf2 and Tfam in the hippocampus of mice was determined. Behavioural research data showed the antidepressant effect of fluoxetine and Mito - TEMPO administered to mice alone and in combination. The molecular research results indicate a significant impact of chronic stress on the oxidation-reduction balance and an antioxidant effect of Mito - TEMPO. The results obtained in the study suggest that Mito - TEMPO protects DNA against oxidative damage and may be beneficial in the way of cellular function improvement under the conditions of chronic stress. Adora1, Msra, Nrf2 and Tfam genes may be involved in mediating the antioxidant effect of the combined treatment with fluoxetine and Mito - TEMPO.

SARS-CoV-2 infection, COVID-19 pathogenesis, and exposure to air pollution: What is the connection?

Exposure to air pollutants has been previously associated with respiratory viral infections, including influenza, measles, mumps, rhinovirus, and respiratory syncytial virus. Epidemiological studies have also suggested that air pollution exposure is associated with increased cases of SARS-CoV-2 infection and COVID-19-associated mortality, although the molecular mechanisms by which pollutant exposure affects viral infection and pathogenesis of COVID-19 remain unknown. In this review, we suggest potential molecular mechanisms that could account for this association. We have focused on the potential effect of exposure to nitrogen dioxide (NO2 ), ozone (O3 ), and particulate matter (PM) since there are studies investigating how exposure to these pollutants affects the life cycle of other viruses. We have concluded that pollutant exposure may affect different stages of the viral life cycle, including inhibition of mucociliary clearance, alteration of viral receptors and proteases required for entry, changes to antiviral interferon production and viral replication, changes in viral assembly mediated by autophagy, prevention of uptake by macrophages, and promotion of viral spread by increasing epithelial permeability. We believe that exposure to pollutants skews adaptive immune responses toward bacterial/allergic immune responses, as opposed to antiviral responses. Exposure to air pollutants could also predispose exposed populations toward developing COIVD-19-associated immunopathology, enhancing virus-induced tissue inflammation and damage.

The relevant targets of anti-oxidative stress: a review

Previous studies have found that oxidative stress is the negative reaction of the imbalance between oxidation and antioxidation caused by free radicals, and it is the fuse of aging and many diseases. Scavenging the accumulation of free radicals in the body and inhibiting the production of free radicals are effective ways to reduce the occurrence of oxidative stress. In recent years, studies have found that oxidative stress has other effects on the body, such as anti-tumour. In this paper, the targets related to anti-oxidative stress were introduced, and they were divided into nuclear transcription factors, enzymes, solute carrier family 7, member 11 (SLC7A11) genes and iron death, ion channels, molecular chaperones, small molecules according to their different functions. In addition, we introduce the research status of agonists/inhibitors related to these targets, so as to provide some reference for the follow-up research and clinical application of anti-oxidative stress drugs.

Anti-inflammatory and antitumor activities of the chloroform extract and anti-inflammatory effect of the three diterpenes isolated from Salvia ballotiflora Benth

BACKGROUND

Drugs used for the treatment of diseases associated with chronic inflammation, such as cancer and rheumatoid arthritis have the potential to cause undesirable side-effects, which might result in patients ending treatment prematurely. However, plants are a viable option for the treatment of inflammatory diseases. In this study, we assessed the in vivo and in vitro anti-inflammatory activity, and the antitumor effects of the chloroform extract of Salvia ballotiflora (ECL). The pro-apoptotic effects of ECL in CT26 cells were also determined.

METHODS

The chloroform extract of Salvia ballotiflora (ECL) was standardized using 19-deoxyicetexone (DEOX) as a phytochemical marker. The anti-inflammatory activity of ECL was determined on acute and chronic inflammatory models using the TPA-induced mouse ear edema assay. The antitumor activity of ECL was evaluated by the subcutaneous inoculation of CT26 cells on the back of Balb/c mice. In vitro CT26 cell death induced by ECL was determined by Annexin V/propidium iodide staining assay using flow cytometry. ECL and the diterpenes isolated from the chloroform extract included 19-deoxyicetexone (DEOX), icetexone (ICT), and 7,20-dihydroanastomosine (DAM), which were tested in LPS-stimulated J774A.1 macrophages to quantify pro-inflammatory cytokine levels. The in vitro anti-arthritic activity of ECL was determined using the bovine serum protein (BSP) denaturation assay.

RESULTS

ECL exerted anti-inflammatory activities in acute (84% of inhibition, 2 mg/ear) and chronic models (62.71%, at 100 mg/kg). ECL showed antitumor activity at 200 mg/kg and 300 mg/kg, reducing tumor volume by 30 and 40%, respectively. ECL (9.5 μg/mL) induced in vitro apoptosis in CT26 cells by 29.1% (48 h of treatment) and 93.9% (72 h of treatment). ECL (10 μg/ml) decreased levels of NO (53.7%), pro-inflammatory cytokines IL-6 (44.9%), IL-1β (71.9%), and TNF-α (40.1%), but increased the production of the anti-inflammatory cytokine IL-10 (44%). The diterpenes DEOX, ICT, and DAM decreased levels of NO (38.34, 47.63, 67.15%), IL-6 (57.84, 60.45, 44.26%), and TNF-α (38.90, 31.30, 32.83%), respectively. ECL showed in vitro antiarthritic activity (IC₅₀ = 482.65 μg/mL).

CONCLUSIONS

ECL exhibited anti-inflammatory and anti-tumor activities. Furthermore, the diterpenes DEOX, DAM, and ICT showed anti-inflammatory activity by reducing levels of NO, TNF-α, and IL-6.

Ecotoxicology of Heavy Metal(loid)-Enriched Particulate Matter: Foliar Accumulation by Plants and Health Impacts

Atmospheric contamination by heavy metal-enriched particulate matter (metal-PM) is highly topical nowadays because of its high persistence and toxic nature. Metal-PMs are emitted to the atmosphere by various natural and anthropogenic activities, the latter being the major source. After being released into the atmosphere, metal-PM can travel over a long distance and can deposit on the buildings, water, soil, and plant canopy. In this way, these metal-PMs can contaminate different parts of the ecosystem. In addition, metal-PMs can be directly inhaled by humans and induce several health effects. Therefore, it is of great importance to understand the fate and behavior of these metal-PMs in the environment. In this review, we highlighted the atmospheric contamination by metal-PMs, possible sources, speciation, transport over a long distance, and deposition on soil, plants, and buildings. This review also describes the foliar deposition and uptake of metal-PMs by plants. Moreover, the inhalation of these metal-PMs by humans and the associated health risks have been critically discussed. Finally, the article proposed some key management strategies and future perspectives along with the summary of the entire review. The abovementioned facts about the biogeochemical behavior of metal-PMs in the ecosystem have been supported with well-summarized tables (total 14) and figures (4), which make this review article highly informative and useful for researchers, scientists, students, policymakers, and the organizations involved in development and management. It is proposed that management strategies should be developed and adapted to cope with atmospheric release and contamination of metal-PM.

Novel target for treating Alzheimer's Diseases: Crosstalk between the Nrf2 pathway and autophagy

In mammals, the Keap1-Nrf2-ARE pathway (henceforth, "the Nrf2 pathway") and autophagy are major intracellular defence systems that combat oxidative damage and maintain homeostasis. p62/SQSTM1, a ubiquitin-binding autophagy receptor protein, links the Nrf2 pathway and autophagy. Phosphorylation of p62 dramatically enhances its affinity for Keap1, which induces Keap1 to release Nrf2, and the p62-Keap1 heterodimer recruits LC3 and mediates the permanent degradation of Keap1 in the selective autophagy pathway. Eventually, Nrf2 accumulates in the cytoplasm and then translocates into the nucleus to activate the transcription of downstream genes that encode antioxidant enzymes, which protect cells from oxidative damage. Since Nrf2 also upregulates the expression of the p62 gene, a p62-Keap1-Nrf2 positive feedback loop is created that further enhances the protective effect on cells. Studies have shown that the p62-activated noncanonical Nrf2 pathway is an important marker of neurodegenerative diseases. The p62-Keap1-Nrf2 positive feedback loop and the Nrf2 pathway are involved in eliminating the ROS and protein aggregates induced by AD. Therefore, maintaining the homeostasis of the p62-Keap1-Nrf2 positive feedback loop, which is a bridge between the Nrf2 pathway and autophagy, may be a potential target for the treatment of AD.

Oxido-inflammatory responses and histological alterations in rat lungs exposed to petroleum product fumes

Petroleum products-petrol, kerosene, and diesel-composed of volatile organic constituents contribute to air pollution. Exposure of gas station attendants (GSAs) to petroleum products fumes (PPFs) may account for occupation-related predisposition to respiratory toxicity and disease pathogenesis. We simulated GSA exposure to PPF inhalation and examined their effect on oxido-inflammatory responses, toxicity, and histopathological alterations in rat lungs, following 8-hours daily exposure for 60 and 90 days. Reactive oxygen and nitrogen species (RONS), oxidative stress and inflammatory biomarkers, namely: superoxide dismutase (SOD), reduced glutathione (GSH), glutathione peroxidase (GPx), glutathione-S-transferase (GST), TNF-α, IL-1β, xanthine oxidase (XO), nitric oxide (NO) activity were evaluated. Besides, histopathological examination of the lungs and trachea of exposed rats, PPF exposure resulted in significant (P < .05) increases in RONS, biomarkers of oxidative stress, pro-inflammation cytokines, and reduced (P < .05) GSH levels in rats, secondary to histopathological alteration in lungs and trachea cytoarchitecture examined in an exposure-duration-dependent manner. We conclude, therefore, that the observed biochemical and histological changes create a microenvironment that is permissive to diseases pathogenesis of the respiratory system via oxido-inflammatory mechanistic pathways.

A Double-Edged Sword: The Anti-Cancer Effects of Emodin by Inhibiting the Redox-Protective Protein MTH1 and Augmenting ROS in NSCLC

Background: Reactive oxygen species (ROS), playing a two-fold role in tumorigenesis, are responsible for tumor formation and progression through the induction of genome instability and pro-oncogenic signaling. The same ROS is toxic to cancer cells at higher levels, oxidizing free nucleotide precursors (dNTPs) as well as damaging DNA leading to cell senescence. Research has highlighted the tumor cell-specific expression of a redox-protective phosphatase, MutT homolog 1 (MTH1), that performs the enzymatic conversion of oxidized nucleotides (like 8-oxo-dGTP) to their corresponding monophosphates, up-regulated in numerous cancers, circumventing their misincorporation into the genomic DNA and preventing damage and cell death. Methods: To identify novel natural small molecular inhibitors of MTH1 to be used as cancer therapeutic agents, molecular screening for MTH1 active site binders was performed from natural small molecular libraries. Emodin was identified as a lead compound for MTH1 active site functional inhibition and its action on MTH1 inhibition was validated on non-small cell lung cancer cellular models (NSCLC). Results: Our study provides strong evidence that emodin mediated MTH1 inhibition impaired NSCLC cell growth, inducing senescence. Emodin treatment enhanced the cellular ROS burdens, on one hand, damaged dNTP pools and inhibited MTH1 function on the other. Our work on emodin indicates that ROS is the key driver of cancer cell-specific increased DNA damage and apoptosis upon MTH1 inhibition. Consequently, we observed a time-dependent increase in NSCL cancer cell susceptibility to oxidative stress with emodin treatment. Conclusions: Based on our data, the anti-cancer effects of emodin as an MTH1 inhibitor have clinical potential as a single agent capable of functioning as a ROS inducer and simultaneous blocker of dNTP pool sanitation in the treatment of NSCL cancers. Collectively, our results have identified for the first time that the potential molecular mechanism of emodin function, increasing DNA damage and apoptosis in cancer cells, is via MTH1 inhibition.

Size distributions of particle-generated hydroxyl radical (·OH) in surrogate lung fluid (SLF) solution and their potential sources

Although it is known that increases in ambient particulate matter (PM) levels are associated with elevated occurrence of adverse health outcomes, the understanding of the mechanisms of PM-related health effects is limited by our knowledge of how particle size and composition are altered subsequent to inhalation through respiratory-deposited processing. Here we present a particle-generated hydroxyl radical (·OH) study of the size-resolved particles as particles are inhaled in the human respiratory tract (RT), and we show that accumulation-mode particles are significant factors (71-75%) in ·OH generation of lung-deposited particles using Multiple-Path Particle Dosimetry (MPPD) model. The ability of PM to catalyze ·OH generation is mainly related to transition metals, particularly towards the upper regions of the RT (75%), and to quinones deeper in the lung (42-46%). Identification of this generation ability induced by chemical composition has shown that four potential sources (biomass burning, incomplete combustion, mobile & industry, and mineral dust) are responsible for ·OH generation. With ·OH-forming ability after PM inhalation implicated as the first step towards revealing the subsequent toxic processes, this work draws a connection between the detailed ·OH chemistry occurring on size-resolved particles and a possible toxicological mechanism based on chemical composition and sources.

Joint effects of microplastic and dufulin on bioaccumulation, oxidative stress and metabolic profile of the earthworm (Eisenia fetida)

Microplastics and pesticides are identified as two environmental pollutants that have an adverse impact on the environment. The knowledge about the combined exposure of pesticides and microplastics may facilitate further assessment of their ecotoxicity. In this study, we investigated joint effects of microplastic and dufulin on bioaccumulation, oxidative stress and metabolic profile of the earthworm. Bioaccumulation analysis showed that the bio-soil accumulation factor of dufulin in earthworms reached its maximum value on the 14th day, and microplastics could significantly increase the bioaccumulation of dufulin in earthworms. Biochemical analysis showed that the oxidative damage of earthworms could be observed on the 14th day of the exposure to dufulin, while the oxidative damage of earthworms could be observed on the 7th day of the combined exposure to microplastics and dufulin, and it could still be observed on the 14th day. ¹H-NMR-based metabolomics revealed that the exposure of dufulin significantly altered the relative abundances of 14 metabolites and two metabolic pathways, but the combined exposure of dufulin and microplastics significantly changed the relative abundances of 21 metabolites and three metabolic pathways. It could be seen that microplastics could aggravate the oxidative damage and the interference with the metabolic profile caused by dufulin to earthworms. The results of this study could provide effective information for the risk assessment of dufulin and microplastic in environmental safety.

Numerical Simulation of the Distribution of In Situ Cigarette Combustion-Generated Particulate Matter

This paper has established a two-dimensional (2D) mathematical model for the generation, growth, and deposition of cigarette total particulate matter (TPM) in the smoldering state. The model has covered the chemical reactions and mass transfer as well as the mechanism of generation, flow, and condensation of particulate matter inside a burning cigarette. Cigarette smoke was generated by puffing under a constant pressure, and the pressure of the filter outlet was −274 Pa. The peak of the concentration of particulate matter was spatially overlapped with the peaks of pyrolysis and oxidation. Pertaining to the cross section of the cigarette at the same axial position, the peak of the diameter of particulate matter along the radial distribution first appeared in the zone near the edge of the cigarette cross section, and then gradually moved to the center of the cigarette with the cigarette smoke moving away from the combustion cone. The maximum number density of particulate matter calculated by the 2D mathematical model at the same axial position of the cigarette and the corresponding particle diameter, as well as the filtration efficiency of the filter rod, are in good accordance with the experimental data reported in previous studies.

Endoplasmic Reticulum Stress Provocation by Different Nanoparticles: An Innovative Approach to Manage the Cancer and Other Common Diseases

A proper execution of basic cellular functions requires well-controlled homeostasis including correct protein folding. Endoplasmic reticulum (ER) implements such functions by protein reshaping and post-translational modifications. Different insults imposed on cells could lead to ER stress-mediated signaling pathways, collectively called the unfolded protein response (UPR). ER stress is also closely linked with oxidative stress, which is a common feature of diseases such as stroke, neurodegeneration, inflammation, metabolic diseases, and cancer. The level of ER stress is higher in cancer cells, indicating that such cells are already struggling to survive. Prolonged ER stress in cancer cells is like an Achilles' heel, if aggravated by different agents including nanoparticles (NPs) may be exhausted off the pro-survival features and can be easily subjected to proapoptotic mode. Different types of NPs including silver, gold, silica, graphene, etc. have been used to augment the cytotoxicity by promoting ER stress-mediated cell death. The diverse physico-chemical properties of NPs play a great role in their biomedical applications. Some special NPs have been effectively used to address different types of cancers as these particles can be used as both toxicological or therapeutic agents. Several types of NPs, and anticancer drug nano-formulations have been engineered to target tumor cells to enhance their ER stress to promote their death. Therefore, mitigating ER stress in cancer cells in favor of cell death by ER-specific NPs is extremely important in future therapeutics and understanding the underlying mechanism of how cancer cells can respond to NP induced ER stress is a good choice for the development of novel therapeutics. Thus, in depth focus on NP-mediated ER stress will be helpful to boost up developing novel pro-drug candidates for triggering pro-death pathways in different cancers.

Nucleotide de novo synthesis increases breast cancer stemness and metastasis via cGMP-PKG-MAPK signaling pathway

Metabolic reprogramming to fulfill the biosynthetic and bioenergetic demands of cancer cells has aroused great interest in recent years. However, metabolic reprogramming for cancer metastasis has not been well elucidated. Here, we screened a subpopulation of breast cancer cells with highly metastatic capacity to the lung in mice and investigated the metabolic alternations by analyzing the metabolome and the transcriptome, which were confirmed in breast cancer cells, mouse models, and patients' tissues. The effects and the mechanisms of nucleotide de novo synthesis in cancer metastasis were further evaluated in vitro and in vivo. In our study, we report an increased nucleotide de novo synthesis as a key metabolic hallmark in metastatic breast cancer cells and revealed that enforced nucleotide de novo synthesis was enough to drive the metastasis of breast cancer cells. An increased key metabolite of de novo synthesis, guanosine-5'-triphosphate (GTP), is able to generate more cyclic guanosine monophosphate (cGMP) to activate cGMP-dependent protein kinases PKG and downstream MAPK pathway, resulting in the increased tumor cell stemness and metastasis. Blocking de novo synthesis by silencing phosphoribosylpyrophosphate synthetase 2 (PRPS2) can effectively decrease the stemness of breast cancer cells and reduce the lung metastasis. More interestingly, in breast cancer patients, the level of plasma uric acid (UA), a downstream metabolite of purine, is tightly correlated with patient's survival. Our study uncovered that increased de novo synthesis is a metabolic hallmark of metastatic breast cancer cells and its metabolites can regulate the signaling pathway to promote the stemness and metastasis of breast cancer.

Atmospheric fine particulate matter and epithelial mesenchymal transition in pulmonary cells: state of the art and critical review of the in vitro studies

Exposure to fine particulate matter (PM_2.5) has been associated with several diseases including asthma, chronic obstructive pulmonary disease (COPD) and lung cancer. Mechanisms such as oxidative stress and inflammation are well-documented and are considered as the starting point of some of the pathological responses. However, a number of studies also focused on epithelial-mesenchymal transition (EMT), which is a biological process involved in fibrotic diseases and cancer progression notably via metastasis induction. Up until now, EMT was widely reported in vivo and in vitro in various cell types but investigations dealing with in vitro studies of PM_2.5 induced EMT in pulmonary cells are limited. Further, few investigations combined the necessary endpoints for validation of the EMT state in cells: such as expression of several surface, cytoskeleton or extracellular matrix biomarkers and activation of transcription markers and epigenetic factors. Studies explored various cell types, cultured under differing conditions and exposed for various durations to different doses. Such unharmonized protocols (1) might introduce bias, (2) make difficult comparison of results and (3) preclude reaching a definitive conclusion regarding the ability of airborne PM_2.5 to induce EMT in pulmonary cells. Some questions remain, in particular the specific PM_2.5 components responsible for EMT triggering. The aim of this review is to examine the available PM_2.5 induced EMT in vitro studies on pulmonary cells with special emphasis on the critical parameters considered to carry out future research in this field. This clarification appears necessary for production of reliable and comparable results.

Understanding the knowledge gaps between air pollution controls and health impacts including pathogen epidemic

Sustainable development calls for a blue sky with quality air. Encouragingly, the current mass reduction-oriented pollution control is making substantial achievements, as the data from Chinese Environmental Monitoring Stations show a significant drop in the annual average concentrations of particulate matters (i.e., PM₁₀ and PM_2.5) and SO₂. But many challenges and knowledge gaps are still confronted nowadays. On one hand, long-term health impacts of fine air particles have to be closely probed through both epidemiological and laboratory studies, and the toxic effects owing to the interactions between particles and associated chemical pollutants should be differentially teased out. On the other hand, due to sole mass control, there are significant changes of overall pollutant fingerprint, such as the increase of ground-level ozone concentration, which should be taken into account for altered health effects relative to the past. Moreover, the interplays with air pollutants and air-borne pathogens should be scrutinized in more details. In other words, it is worth investigating likely spread of pathogens (even for SARS-CoV-2) with aid of aerosols. Here, we recapitulate the current knowledge gaps between air pollution controls and health impacts including pathogen epidemic, and we also propose future research directions to support policy making in balance mass control and health impacts.