Obese rats are more vulnerable to inflammation, genotoxicity and oxidative stress induced by coal dust inhalation than non-obese rats

Associations of coal mine dust exposure with arterial stiffness and atherosclerotic cardiovascular disease risk in chinese coal miners

OBJECTIVE

Whether coal mine dust exposure increases cardiovascular diseases (CVDs) risk was rarely explored. Our objective was to examine the association between coal mine dust exposure and cardiovascular risk.

METHODS

We estimated cumulative coal mine dust exposure (CDE) for 1327 coal miners by combining data on workplace dust concentrations and work history. We used brachial-ankle pulse wave velocity (baPWV, a representative indicator of arterial stiffness) and ten-year atherosclerotic cardiovascular disease (ASCVD) risk to assess potential CVD risk, exploring their associations with CDE.

RESULTS

Positive dose-response relationships of CDE with baPWV and ten-year ASCVD risk were observed after adjusting for covariates. Specifically, each 1 standard deviation (SD) increase in CDE was related to a 0.27 m/s (95% CI: 0.21, 0.34) increase in baPWV and a 1.29 (95% CI: 1.14, 1.46) elevation in OR (odds ratio) of risk of abnormal baPWV. Moreover, each 1 SD increase in CDE was associated with a 0.74% (95% CI: 0.63%, 0.85%) increase in scores of ten-year ASCVD and a 1.91 (95% CI: 1.62, 2.26) increase in OR of risk of ten-year ASCVD. When compared with groups unexposed to coal mine dust, significant increase in the risk of arterial stiffness and ten-year ASCVD in the highest CDE groups were detected.

CONCLUSION

The study suggested that cumulative exposure to coal mine dust was associated with elevated arterial stiffness and ten-year ASCVD risk in a dose-response manner. These findings contribute valuable insights for cardiovascular risk associated with coal mine dust.

Ecotoxicity of perfluorooctanoic acid and perfluorooctane sulfonate on aquatic plant Vallisneria natans

Perfluorinated compounds (PFCs) are persistent organic contaminants that are highly toxic to the environment and bioaccumulate, but their ecotoxic effects on aquatic plants remain unclear. In this study, the submerged plant Vallisneria natans was treated with short-term (7 days) and long-term (21 days) exposures to perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) at concentrations of 0, 0.01, 0.1, 1.0, 5.0, and 10 mg/L, respectively. The results showed that both high concentrations of PFOA and PFOS inhibited the growth of V. natans and triggered the increase in photosynthetic pigment content in leaves. The oxidative damage occurred mainly in leaves, but both leaves and roots gradually built up tolerance during the stress process without serious membrane damage. Both leaves and roots replied to short-term stress by activating superoxide dismutase (SOD), catalase (CAT) and polyphenol oxidase (PPO), while peroxidase (POD) was involved under high concentration stress with increasing exposure time. Leaves showed a dose-effect relationship in integrated biomarker response (IBR) values under short-term exposure, and the sensitivity of roots and leaves to PFOS was higher than that of PFOA. Our findings help to increase knowledge of the toxic effects of PFCs and have important reference value for risk assessment and environmental remediation of PFCs in the aquatic ecosystem.

Environmental impacts of Indian coal thermal power plants and associated human health risk to the nearby residential communities: A potential review

Worldwide, harmful emissions from coal power plants cause many illnesses contribute to premature deaths burden. Despite its high impact on human health and being a major source of toxic pollutants, coal has been considered a component of global energy for decades. Hence, this work was envisaged to understand the rising environmental and multiple health issues from coal power plants. Studies on the adverse impacts of coal power plants on the environment, including soil, surface water, groundwater and air, were critically evaluated. The health risk from exposure to different pollutants and toxic metals released from the power plant was also demonstrated. The study also highlighted the government initiatives and policies regarding coal power operation and generation. Lastly, the study focused on guiding coal power plant owners and policymakers in identifying the essential cues for the risk assessment and management. The current study found an association between environmental and human health risks due to power generation, which needs intervention from the scientific and medical fields to jointly address public concerns. It is also suggested that future research should concentrate on exposure assessment techniques by integrating source-identification and geographic information systems to assess the health effects of different contaminants from power plants and to mitigate their adverse impact.

Oxidative stress in animal models of obesity caused by hypercaloric diets: A systematic review

Obesity is a global health difficulty characterized by an excessive accumulation of fat that increases body weight. Obesity has been studied in multiple animal models, of which those in which it is induced by diet stand out. Due to the increase in this condition, other mechanisms have been addressed that are triggered by states of overweight or obesity, such as the appearance of oxidative stress. These models aim to relate obesity caused by diet and how it influences the development of oxidative stress. In this study, a systematic review of the literature of 39 articles that studied obesity due to the consumption of hypercaloric diets and the appearance of oxidative stress in different animal models was carried out. This review identified the models with the most excellent use and the characteristics of the most appropriate diets to characterize states of oxidative stress due to obesity. In addition, the advantages and disadvantages of each model used are provided, as well as the techniques used for the assessment of obesity, and oxidative stress, providing the information in such a way that there is a general overview of the existing models of the parameters that allow to adequately establish both variables studied, providing information that allows the researcher to choose the appropriate model and factors according to the interest and objectives of the present research.

A role of STING signaling in obesity-induced lung inflammation

BACKGROUND

It is established that pulmonary disorders are comorbid with metabolic disorders such as obesity. Previous studies show that the stimulator of interferon genes (STING) signaling plays crucial roles in obesity-induced chronic inflammation via TANK-binding kinase 1 (TBK1) pathways. However, it remains unknown whether and how the STING signaling is implicated in the inflammatory processes in the lung in obesity.

METHODS

Human lung tissues were obtained from obese patients (n = 3) and controls (n = 3). Mice were fed with the high-fat diet or regular control diet to establish the diet-induced obese (DIO) and lean mice, and were treated with C-176 (a specific STING inhibitor) or vehicle respectively. The lung macrophages were exposed to palmitic acid (PA) in vitro. The levels of STING singaling and metabolic inflammation factors were detected and anlyzed.

RESULTS

We find that STING+/CD68+ macrophages are increased in lung tissues in patients with obesity. Our data also show that the expressions of STING and the levels of proinflammatory cytokines are increased both in lung tissues and bronchoalveolar lavage fluid (BALF) in obesity compared to controls, and inhibition of the STING blunted the obesity-induced lung inflammation. Mechanistically, our data demonstrate that the STING signaling pathway is involved in the PA-induced inflammation through the STING-TBK1-IRF3 (interferon regulatory factor 3)/NF-κB (nuclear factor kappa B) pathways in the lung macrophages.

CONCLUSIONS

Our results collectively suggest that the STING signaling contributes to obesity-associated inflammation by stimulating proinflammatory processes in lung macrophages, one that may serve as a therapeutic target in ameliorating obesity-related lung dysfunctions.

Lipid metabolism, BMI and the risk of nonalcoholic fatty liver disease in the general population: evidence from a mediation analysis

BACKGROUND

Body mass index (BMI) and lipid parameters are the most commonly used anthropometric parameters and biomarkers for assessing nonalcoholic fatty liver disease (NAFLD) risk. This study aimed to assess and quantify the mediating role of traditional and non-traditional lipid parameters on the association between BMI and NAFLD.

METHOD

Using data from 14,251 subjects from the NAGALA (NAfld in the Gifu Area, Longitudinal Analysis) study, mediation analyses were performed to explore the roles of traditional [total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C)] and non-traditional [non-HDL-C, remnant cholesterol (RC), TC/HDL-C ratio, LDL-C/HDL-C ratio, TG/HDL-C ratio, non-HDL-C/HDL-C ratio, and RC/HDL-C ratio] lipid parameters in the association of BMI with NAFLD and quantify the mediation effect of these lipid parameters on the association of BMI with NAFLD using the percentage of mediation.

RESULT

After fully adjusting for confounders, multivariate regression analysis showed that both BMI and lipid parameters were associated with NAFLD (All P-value < 0.001). Mediation analysis showed that both traditional and non-traditional lipid parameters mediated the association between BMI and NAFLD (All P-value of proportion mediate < 0.001), among which non-traditional lipid parameters such as RC, RC/HDL-C ratio, non-HDL-C/HDL-C ratio, and TC/HDL-C ratio accounted for a relatively large proportion, 11.4%, 10.8%, 10.2%, and 10.2%, respectively. Further stratified analysis according to sex, age, and BMI showed that this mediation effect only existed in normal-weight (18.5 kg/m² ≤ BMI < 25 kg/m²) people and young and middle-aged (30-59 years old) people; moreover, the mediation effects of all lipid parameters except TC accounted for a higher proportion in women than in men.

CONCLUSION

The new findings of this study showed that all lipid parameters were involved in and mediated the risk of BMI-related NAFLD, and the contribution of non-traditional lipid parameters to the mediation effect of this association was higher than that of traditional lipid parameters, especially RC, RC/HDL-C ratio, non-HDL-C/HDL-C ratio, and TC/HDL-C ratio. Based on these results, we suggest that we should focus on monitoring non-traditional lipid parameters, especially RC and RC/HDL-C ratio, when BMI intervention is needed in the process of preventing or treating NAFLD.

PM2.5-induced adipose tissue dysfunction can trigger metabolic disturbances

Exposure to particulate matter ≤2.5 μm in diameter (PM_2.5) alters cardiometabolic homeostasis. The reduced oxidative capacity in brown adipocytes and the development of inflammation and insulin resistance in white adipose tissue (WAT) can account for the dysmetabolic setting on PM_2.5 exposure. In this forum article, we discuss relevant evidence to highlight a causal connection between PM_2.5-induced adipose tissue dysfunction and cardiometabolic disturbances.

The macrophage senescence hypothesis: the role of poor heat shock response in pulmonary inflammation and endothelial dysfunction following chronic exposure to air pollution

INTRODUCTION

Cardiovascular diseases (CVD) have been associated with high exposure to fine particulate air pollutants (PM_2.5). Alveolar macrophages are the first defense against inhaled particles. As soon as they phagocytize the particles, they reach an inflammatory phenotype, which affects the surrounding cells and associates with CVD. Not coincidentally, CVD are marked by a depleted heat shock response (HSR), defined by a deficit in inducing 70-kDa heat shock protein (HSP70) expression during stressful conditions. HSP70 is a powerful anti-inflammatory chaperone, whose reduced levels trigger a pro-inflammatory milieu, cellular senescence, and a senescence-associated secretory phenotype (SASP). However, whether macrophage senescence is the main mechanism by which PM_2.5 propagates low-grade inflammation remains unclear.

OBJECTIVE AND DESIGN

In this article, we review evidence supporting that chronic exposure to PM_2.5 depletes HSR and determines the ability to solve the initial stress.

RESULTS AND DISCUSSION

When exposed to PM_2.5, macrophages increase the production of reactive oxygen species, which activate nuclear factor-kappa B (NF-κB). NF-κB is naturally a pro-inflammatory factor that drives prostaglandin E2 (PGE2) synthesis and causes fever. PGE2 can be converted into prostaglandin A2, a powerful inducer of HSR. Therefore, when transiently activated, NF-κB can trigger the anti-inflammatory response through negative feedback, by inducing HSP70 expression. However, when chronically activated, NF-κB heads a set of pathways involved in mitochondrial dysfunction, endoplasmic reticulum stress, unfolded protein response, inflammasome activation, and apoptosis. During chronic exposure to PM_2.5, cells cannot properly express sirtuin-1 or activate heat shock factor-1 (HSF-1), which delays the resolution phase of inflammation. Since alveolar macrophages are the first immune defense against PM_2.5, we suppose that the pollutant impairs HSR and, consequently, induces cellular senescence. Accordingly, senescent macrophages change its secretory phenotype to a more inflammatory one, known as SASP. Finally, macrophages' SASP would propagate the systemic inflammation, leading to endothelial dysfunction and atherosclerosis.

Understanding the pathogenesis of occupational coal and silica dust-associated lung disease

Workers in the mining and construction industries are at increased risk of respiratory and other diseases as a result of being exposed to harmful levels of airborne particulate matter (PM) for extended periods of time. While clear links have been established between PM exposure and the development of occupational lung disease, the mechanisms are still poorly understood. A greater understanding of how exposures to different levels and types of PM encountered in mining and construction workplaces affect pathophysiological processes in the airways and lungs and result in different forms of occupational lung disease is urgently required. Such information is needed to inform safe exposure limits and monitoring guidelines for different types of PM and development of biomarkers for earlier disease diagnosis. Suspended particles with a 50% cut-off aerodynamic diameter of 10 µm and 2.5 µm are considered biologically active owing to their ability to bypass the upper respiratory tract's defences and penetrate deep into the lung parenchyma, where they induce potentially irreversible damage, impair lung function and reduce the quality of life. Here we review the current understanding of occupational respiratory diseases, including coal worker pneumoconiosis and silicosis, and how PM exposure may affect pathophysiological responses in the airways and lungs. We also highlight the use of experimental models for better understanding these mechanisms of pathogenesis. We outline the urgency for revised dust control strategies, and the need for evidence-based identification of safe level exposures using clinical and experimental studies to better protect workers' health.

Potential uses of phosphogypsum: A review

Phosphogypsum (PG) is a by-product of the phosphate fertilizer industry that is produced during the phosphoric acid production process. Annual global PG production ranges between 100 to 300 Mt, with only 15% of that utilized while the rest is usually placed on large dumps with potential serious human and environmental impacts. The aim of this study is to give an overview and to evaluate the existing and potential uses of PG that extend from soil stabilization to cement and chemical industry and for agricultural to geotechnical, human impacts, and environmental applications. More specifically, PG can be used as a substitute in the cement industry, in building materials and in road construction, as a fertilizer for soil improvement, as a raw material for the production of some chemicals, and as a backfilling material for the rehabilitation of abandoned mines and quarries, while the recovery of gypsum and the extraction of rare earth elements signifies the potential importance of PG to cyclic economy. The paper offers an extensive overview of existing and potential uses of PG, discusses their adequacy, and reveals that PG can be widely used under certain conditions, rather than disposed as waste in stockpiles.

Elucidation of alveolar macrophage cell response to coal dusts: Role of ferroptosis in pathogenesis of coal workers' pneumoconiosis

Causal factors underlying coal workers' pneumoconiosis (CWP) have been variously attributed to the presence of carbon, crystalline silica and reduced iron (Fe) minerals, especially pyrite and Fe/Si-amorphous compounds. The aim of this research was to assess the role of iron in CWP and, more specifically, the cytotoxicity of coal dusts with different elemental composition towards alveolar macrophages (AMs). Survival rate of AMs, alteration in the production of pro-inflammatory cytokine TNF-α, MDA (the lipid peroxidation product) and intracellular GSH were assessed using commercial assay kits. The quantitative interaction between iron and GSH was investigated by developing a numerical model. The presence of various reduced Fe minerals (viz. pyrite and siderite) in coal dusts exhibited a consistently acute adverse impact on the viability of AMs and enhanced the production of TNF-α. The presence of the clinically available Fe chelator deferiprone (DFP) and the cytosolic antioxidant glutathione (GSH) significantly increased the viability of AMs exposed to Fe bearing coal dusts, suggesting coal dusts containing reduced Fe minerals were likely contributors to the initial stages of AM cytotoxicity via a ferroptosis related pathway. Chemical kinetic modeling indicated that these results may be attributed to an enhanced consumption of GSH as a result of Fe redox cycling. Fe^IIGSH and GS^• produced from the interaction between ferric Fe and GSH facilitated the production of O₂^•- which further oxidized GSH via a direct reaction between GSH and GS^• or GSO^•. These results suggest that coal dusts containing reduced Fe minerals and Fe compounds may elevate acute inflammation levels in AMs, indicating that crystalline silica may not be the only hazard of concern in mining environments.

The effects of coal dust exposure on DNA damage and repair of human bronchial epithelial cells

To explore the effects of coal dust exposure on DNA damage and repair, human bronchial epithelial BEAS-2B cells were exposed to coal dust and the cellular response was investigated. It was found that γ-H2AX foci of DNA damage appeared, γ-H2AX protein level increased, and the rate of cell apoptosis was significantly elevated when BEAS-2B cells were exposed to coal dust for a short time. Phagocytized coal dust particles, swollen mitochondria, and reduced mitochondrial membrane potential were simultaneously identified. Moreover, Caspase-9, Caspase-3, and DFF45 proteins of the mitochondrial apoptotic pathway were activated. After the cells were exposed to coal dust chronically, phosphorylation levels of DNA repair kinases (ATM/ATR, DNA-PKcs) and downstream regulatory protein AKT were significantly upregulated. γ-H2AX foci and tail DNA of the cells following treatment with cisplatin were also reduced, and the colony formation rate was improved. It was concluded that coal dust could induce DNA damage, cause mitochondrial depolarization, and activate mitochondrial apoptosis pathways in BEAS-2B cells. Additionally, activated DNA repair kinases (ATM/ATR and DNA-PKcs) and their regulatory protein AKT increased DNA repair and proliferation of BEAS-2B cells chronically exposed to coal dust.

Adverse associations of different obesity measures and the interactions with long-term exposure to air pollutants with prevalent type 2 diabetes mellitus: The Henan Rural Cohort study

BACKGROUND

Obesity and ambient air pollution are independent risk factors of type 2 diabetes mellitus (T2DM), however, the evidence regarding their joint associations on T2DM was sparsely studied in low-middle income countries.

METHODS

A total of 38,841 participants were selected from Henan Rural Cohort study which was carried out during 2015-2017. Obesity was identified by body mass index (BMI), WC (waist circumstance), WHR (waist-to-hip ratio), WHtR (waist-to-height ratio), BFP (body fat percent), and VFI (visceral fat index). Three-year averaged-concentrations of NO₂, PM₁, PM_2.5, and PM₁₀ were assessed by using the method of spatiotemporal model incorporated into the satellites data. The independent associations of obesity indicators and exposure to air pollutants on fasting blood glucose (FBG) and T2DM were assessed by generalized linear and logistic regression model, respectively, and their interaction associations on T2DM were quantified by using relative excess risk due to interaction (RERI), attributable proportion due to interaction (AP), and synergy index (S).

RESULTS

Positive associations of six obesity measures and four air pollutants with FBG levels and prevalent T2DM were observed. Obese participants measured by BMI plus high exposure to NO₂, PM₁, PM_2.5 and PM₁₀ were related to a 2.96-fold (2.66-3.29), 2.87-fold (2.58-3.20), 2.98-fold (2.67-3.32) and 3.01-fold (2.70-3.35) increased risk for prevalent T2DM, respectively; similarity of joint associations of the other obesity measures and air pollutants on T2DM were observed. The additive associations of different obesity measures and air pollutants with prevalent T2DM were further found.

CONCLUSIONS

The synergistic associations of obesity and air pollutants on FBG levels and prevalent T2DM were observed, indicating that obese participants were at high risk for prevalent T2DM in highly polluted rural regions.

Atomic sheets of silver ferrite with universal microwave catalytic behavior

Prompt degradation of organic pollutants renders microwave (MW) catalysis technology extremely lucrative; ideal microwave catalysts are therefore being hunted with an unprecedented urgency. Ideal functional microwave catalyst should be highly crystalline, room temperature ferromagnetic (for magnetic retrieval), highly dielectric (for sufficient microwave absorption) apart from being structurally stable at high temperature. The potential of silver ferrite 2D sheets (2D AFO) synthesized using a novel microwave technique as a microwave catalyst for the degradation of a variety of organic dyes and antibiotics was investigated in this article. While organic dyes like malachite green (MG), brilliant green (BG) and nile blue A (NB) achieved 99.2%, 98.8% and 95.2%, respectively; antibiotic tetracycline hydrochloride (TCH) molecule resulted in 75.8% degradation efficiency. Total organic carbon (TOC) measurements yielded 76%, 59.1%, 49.1% and 47.6% of carbon content for MG, BG, NB and TCH, respectively. The reaction pathway via intermediates and subsequent degradation to CO₂ and H₂O is revealed by liquid chromatography-mass spectrometry (LCMS). Both superoxide and hydroxyl radicals are participating in the process, according to scavenger tests. The evolution of silver ferrite as a new 2D material and its demonstration as an ideal microwave catalyst will lead to a new beginning in catalysis science and technology.

Geochemical and Morphological Evaluations of Organic and Mineral Aerosols in Coal Mining Areas: A Case Study of Santa Catarina, Brazil

Numerous researchers have described the correlation between the short-term contact of nano-particulate (NP) matter in diverse coal phases and amplified death or hospitalizations for breathing disorders in humans. However, few reports have examined the short-term consequences of source-specific nanoparticles (NPs) on coal mining areas. Advanced microscopic techniques can detect the ultra-fine particles (UFPs) and nanoparticles that contain potential hazardous elements (PHEs) generated in coal mining areas. Secondary aerosols that cause multiple and complex groups of particulate matter (PM10, PM2.5, PM1) can be collected on dry deposition. In this study, scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HR-TEM) were employed to detect and define the magnitude of particulate matters on restaurants walls at coal mines due to weathering interactions. The low cost self-made passive sampler (SMPS) documented several minerals and amorphous phases. The results showed that most of the detected coal minerals exist in combined form as numerous complexes comprising significant elements (e.g., Al, C, Fe, K, Mg, S, and Ti), whereas others exist as amorphous or organic compounds. Based on the analytical approach, the study findings present a comprehensive understanding of existing potential hazardous elements in the nanoparticles and ultrafine particles from coal mining areas in Brazil.

Obesogenic effect of erythromycin on Caenorhabditis elegans through over-eating and lipid metabolism disturbances

Environmental obesogens contributed significantly to the obesity prevalence. Recently, antibiotics joined the list of environmental obesogens, while the underlying mechanisms remained to be explored. In the present study, effects of erythromycin (ERY), one widely used macrolide antibiotic, were measured on C. elegans to investigate the obesogenic mechanism. Results showed that ERY at 0.1 μg/L significantly increased the fat content by 17.4% more than the control and also stimulated triacylglycerol (TAG) levels by 25.7% more than the control. Regarding the obesogenic mechanisms, ERY provoked over-eating by stimulation on the pharyngeal pumping and reduction on the satiety quiescence percentage and duration. Such effects were resulted from stimulation on the neurotransmitters including serotonin (5-HT), dopamine (DA) and acetylcholine (ACh). The nervous responses involved the up-regulation of Gsα (e.g., ser-7, gsa-1, acy-1 and kin-2) signaling pathway and the down-regulation of TGFβ (daf-7) but not via cGMP-dependent regulations (e.g., egl-4). Moreover, ERY stimulated the activities of fatty acid synthase (FAS) and glycerol-3-phosphateacyl transferases (GPAT) that catalyze lipogenesis, while ERY inhibited those of acyl-CoA synthetase (ACS), carnitine palmitoyl transferase (CPT) and acyl-CoA oxidase (ACO) that catalyze lipolysis. The unbalance between lipogenesis and lipolysis resulted in the fat accumulation which was consistent with up-regulation on mgl-1 and mgl-3 which are the down-steam of TGFβ regulation. Such consistence supported the close connection between nervous regulation and lipid metabolism. In addition, ERY also disturbed insulin which connects lipid with glucose in metabolism.

Anti-Inflammatory and Anti-Remodelling Potential of Ethanol Extract Rhodomyrtus Tomentosa in Combination of Asthma and Coal Dust Models

BACKGROUND

Combination of asthma and coal dust is a chronic and recurring airway disease related to inflammation cell activation. The Rhodomyrtus tomentosa flowering plants native to South Kalimantan exhibit a broad therapeutic potential, like anti-inflammatory and anti-remodelling properties. This study aims to analyze the effect of ethanol extract of R. tomentosa leaves (EERTL) nebulizer on the number of inflammatory cells and histomorphometry of lung tissue in a mice-like model of a combination of asthma and coal dust.

METHODS

The 24 BALB/c mice were divided into four treatment groups (n= 6 per group), were sensitized with normal saline (K), OVA + coal dust (P1), OVA + coal dust + salbutamol (P2), and OVA + coal dust + EERTL (P3). Eosinophil cells, neutrophils, lymphocytes, epithelial thickness, smooth muscle, fibrosis subepithelial bronchioles, and the number of goblet cells as indicators of anti-inflammatory and anti-remodelling airways.

RESULTS

The number of eosinophils, neutrophils, and lymphocytes cells are given salbutamol or EERTL was significantly lower than the OVA-sensitized and coal dust exposure group only. There are meaningful differences in the average thickness of the epithelium, smooth muscle, and subepithelial fibrosis of bronchiolus. The histopathology picture of goblet cells showed an increase in the number and size (hyperplasia) in OVA-sensitized and coal dust exposure compared to another group.

CONCLUSION

It was concluded that the EERTL nebulizer could reduce inflammatory cells and remodelling process from bronchoalveolar lavage in the mice combination of asthma and coal dust models.

Indoor Nanoparticle Characterization in Construction Waste Recycling Companies over Time

Building activity is a significant source of atmospheric contamination by ultrafine dust. Cognizant of this fact, those active in the use and recycling of construction materials must be aware of the risks associated with exposure to nanoparticles (NPs) and ultra-fine particles (UFPs), as well as the associated health impacts. This work analyzed NPs and UFPs generated in a small building-material recycling company using high-resolution electron microscopes and X-ray Diffraction. A self-made passive sampler (LSPS) that can obtain particulate samples without physical and morphological changes, especially where there is a suspension of particulate material, was used in this study. A total of 96 particulate samples, using the LSPS for three months in four seasons, were collected during the study. Thus, the dry deposition of the particles, which are considered highly harmful to human health, was found in each of the four seasons of the year. It is suggested that for future research, the toxicological evaluations of the particulates in the construction industry should be investigated through the consideration of measures to control and mitigate the health risks of workers regarding exposure to NPs and UFPs.

HSP70 as a biomarker of the thin threshold between benefit and injury due to physical exercise when exposed to air pollution

Physical exercise has acute and chronic effects on inflammatory balance, metabolic regulation, and redox status. Exercise-induced adaptations are mediated by enhanced 70-kDa heat shock protein (HSP70) levels and an improved heat shock response (HSR). Therefore, exercise could be useful against disease conditions [obesity, diabetes mellitus (DM), and exposure to atmospheric pollutants] marked by an impaired HSR. However, exercise performed by obese or diabetic subjects under pollution conditions might also be dangerous at certain intensities. Intensity correlates with an increase in HSP70 levels during physical exercise until a critical point at which the effort becomes harmful and impairs the HSR. Establishing a unique biomarker able to indicate the exercise intensity on metabolism and cellular fatigue is essential to ensure adequate and safe exercise recommendations for individuals with obesity or DM who require exercise to improve their metabolic status and live in polluted regions. In this review, we examined the available evidence supporting our hypothesis that HSP70 could serve as a biomarker for determining the optimal exercise intensity for subjects with obesity or diabetes when exposed to air pollution and establishing the fine threshold between anti-inflammatory and pro-inflammatory exercise effects.

Measurement of mercury with highly selective fluorescent chemoprobe by carbon dots and silver nanoparticles

This work describes a novel fluorescent chemoprobe that uses carbon dots and silver nanoparticles (AgNPs) to monitor mercury ions in aqueous samples attributed to the principle of inner filter effect. The fluorescent response signal of the carbon dots is diminished by AgNPs, attributed to inner filter effect, and is restored with the addition of Hg²⁺. The fluorescent chemoprobe was specific over the range from 0.01 to 2.5 μM and a high sensitivity of 3.6 nM. The chemoprobe was validated using real local aqueous samples, and the spike recoveries of 97.4%-103% were excellent and satisfied. The data indicated that the developed fluorescent chemoprobe was sensitive, selective, stable and reliable. This fluorescent chemoprobe provides a sensitive tool with broad prospects for mercury detection in aqueous samples and the work will offer ideas for designing and constructing novel fluorescent probes.

Comparison of foliar spray and soil irrigation of biogenic CuO nanoparticles (NPs) on elemental uptake and accumulation in lettuce

Nanoparticles (NPs) can be used in several ways in agriculture, including increasing production rates and improving nutritional values in plants. The present study aims to clarify how biogenic copper oxide nanoparticles (CuO NPs) applied by two routes of exposure (foliar spray and soil irrigation) affect the elemental uptake by lettuce. In vivo experiments using lettuce (n = 4) were performed with CuO NPs in comparison with copper salt (CuSO4), considering a final mass added of 20 mg of CuO per plant. The elemental composition of roots was mostly affected by the soil irrigation exposure for both Cu forms (NPs and salt). Neither Cu form added by soil irrigation was translocated to leaves. Copper concentration in leaves was mainly affected by foliar spray exposure for both Cu forms (NPs and salt). All Cu forms through foliar spray were sequestered in the leaves and no translocation to roots was observed. Foliar spray of CuO NPs caused no visual damage in leaves, resulted in less disturbance of elemental composition, and improved dry weight, number of leaves, CO2 assimilation, and the levels of K, Na, S, Ag, Cd, Cr, Cu, and Zn in leaves without causing significant changes in daily intake of most elements, except for Cu. Although Cu concentration increased in leaves by foliar spray of CuO NPs, it remained safe for consumption.

Genotoxicity of fluoride subacute exposure in rats and selenium intervention

The aims of this study were to: (i) examine the toxic effects of sodium fluoride (NaF) in blood, liver, spleen, and brain cells of Wistar rats after the subacute exposure; (ii) explore the potential protective properties of selenium (Se) against fluoride toxicity after the simultaneous administration. Twenty male Wistar rats, eight weeks old, weighing approximately 140-190 g, were divided into four experimental groups (n = 5) as follows: I control-tap water; II NaF 150 ppm; III NaF 150 ppm and Se 1.5 mg/L; IV Se 1.5 mg/L, and had available water with solutions ad libitum for 28 days. DNA damage detected by comet assay was confirmed in the liver, spleen, and brain cells, but not in blood. Selenium supplementation together with NaF decreased DNA damage in liver and spleen cells. According to the histological findings, no changes were observed in spleen and brain tissues after NaF administration. Unlike the observed Se protective effect on the DNA level, no significant reduction of liver tissue injury was observed after the NaF and Se treatment, resulting in mild inflammation. Data of this study suggest that DNA damage after NaF subacute exposure at moderately high concentration was reduced in liver and spleen cells due to Se supplementation, but a similar change was not seen in the brain.

Indoor levels of polycyclic aromatic hydrocarbons (PAHs) from environment tobacco smoke of public bars

In this work level of Polycyclic Aromatic Hydrocarbon (PAHs) from indoor Environment Tobacco Smoke (ETS) of pubic bars in Nigeria was investigated. Indoor air samples were obtained from different public bars using Polyurethane foam (PUF) passive samplers. Analysis of PAHs was carried out using GC-MS operated in selected ion monitoring mode. Result showed the average concentration range of 2.71-9.69 ng/m³ while the ∑ 16 PAHs range from 43.43 to 155.11 ng/m³. The incremental lifetime cancer risk (ILCR) values from inhalation of PAHs in these bars ranged from 2.4×10^-7-5.2×10^-7 while non-carcinogenic risk, Hazard Quotient (HQ) ranged from 2×10^-4-4.5×10^-4. Although these values are lower than WHO permissible limit, nevertheless the study underscores the danger associated with the inhalation of ETS in the public bars in Nigeria.

Portable dehumidifiers as an original matrix for the study of inhalable nanoparticles in school

Good air quality is documented as a significant factor of social justice. The human health hazards associated with air pollution are not distributed equally across cities; the most vulnerable people are more exposed to ambient air as they commute to work and wait for buses or trains at the stations. Aerosols play important roles in atmosphere quality and the climate; their oxidation at the nanoscale level may possibly increase the reactivity and toxicity of atmospheric particulates. Indoor school environments are characterized by high concentrations of different airborne particulate and gaseous pollutants. The documentation of nanoparticles (NPs), ultra-fine particles (UFPs), and micron-size particle species present in indoor primary schools are an important aspect in the recognition of their influence in respirational difficulties and decreased cognitive progress in children. This work utilizes the study of condensed water, sampled with portable dehumidifiers (PD), to describe NPs and UFPs in the vapor stage of enclosed zones. The acquired extracts were analyzed by advanced electron microscopy techniques. A total of 392 NPs and 251 UFPs were examined in a set of 22 samples acquired in moderately limited or inadequately ventilated indoor areas from several schools. Noting that NPs-related disorders happen at particular places of respirational structure, identification of site-specific NPs accumulation should be anticipated in direction to better verify the corresponding human health outcomes resulting from respirable NPs.

Ovariectomy enhances female rats' susceptibility to metabolic, oxidative, and heat shock response effects induced by a high-fat diet and fine particulate matter

Obesity and exposure to fine particulate matter (air pollutant PM_2.5) are important risk factors for metabolic and cardiovascular diseases. They are also related to early menopause. The reduction of 17β-estradiol (E2) levels during female climacteric, marked by menopause, is of significant concern because of its imminent influence on metabolism, redox and inflammatory status. This complex homeostasis-threatening scenario may induce a heat shock response (HSR) in cells, enhancing the expression of the 70 kDa heat shock protein (HSP70). A failure in this mechanism could predispose women to cardiovascular diseases. In this study, we evaluated if the climacteric could represent an additional risk among obese rats exposed to PM_2.5 by worsening lipid, oxidative, and inflammatory parameters and HSP70 in cardiac tissue. We induced obesity in female Wistar rats using a high-fat diet (HFD) (58.3% as fats) and exposed them to 50 μL of saline 0.9% (control, n = 15) or 250 μg residual oil fly ash (ROFA, the inorganic portion of PM_2.5) (polluted, n = 15) by intranasal instillation, 5 days/w for 12 weeks. At the 12th week, we subdivided these animals into four groups: control (n = 6), OVX (n = 9), polluted (n = 6) and polluted + OVX (n = 9). OVX and polluted + OVX were submitted to a bilateral ovariectomy (OVX), a surgical model for menopause, while control and polluted received a false surgery (sham). ROFA exposure and HFD consumption were continued for 12 additional weeks, after which the animals were euthanized. ROFA enhanced the susceptibility to ovariectomy-induced dyslipidemia, while ovariectomy predisposed female rats to the ROFA-induced decrease of cardiac iHSP70 expression. Ovariectomy also decreased the IL-6 levels and IL-6/IL-10 in obese animals, reinforcing a metabolic impairment and a failure to respond to unfavorable conditions. Our results support the hypothesis that obese ovariectomized animals are predisposed to a metabolic worsening under polluted conditions and are at higher risk of cardiovascular diseases.

High-fat diet effect on periapical lesions and hepatic enzymatic antioxidant in rats

AIMS

To evaluate the effects of a high-fat diet (HFD) on the progression of apical periodontitis (AP), local inflammation, systemic antioxidant status, and blood lipid profile in rats.

MAIN METHODS

Sixteen male Wistar rats were fed a standard diet (SD) or a HFD. At the sixth experimental week, the pulp chambers of the mandibular first molars were exposed to develop AP. A glucose tolerance test was performed the week before euthanasia. At the tenth experimental week, the animals were euthanized and the livers were collected to estimate catalase (CAT) and reduced glutathione (GSH) levels. Blood was acquired for biochemical analysis. The size of AP was estimated from radiographs and described as AP size-to-body weight ratio; inflammatory grade of AP was determined by histological analysis.

KEY FINDINGS

At the end of the experimental period, the rats fed the HFD had 30% less weight (P < 0.0001) and higher blood glucose levels after 30 min of sucrose intake (P < 0.05) than those fed the SD. Animals from the HFD group had lower levels of CAT (P < 0.01), but the same was not observed in the GSH levels. Plasma insulin and total cholesterol were not affected by the diet. The rats fed the HFD presented greater AP than those fed the SD (P < 0.05). However, the local inflammatory infiltrate was similar in both groups.

SIGNIFICANCE

The alterations promoted by the consumption of a HFD were not only observed systemically, but also locally, producing greater AP in rats than a SD.

Nanominerals assemblages and hazardous elements assessment in phosphogypsum from an abandoned phosphate fertilizer industry

The present work investigates hazardous elements and nanomineralogical assemblages of phosphogypsum waste from an abandoned phosphate fertilizer industry located in Santa Catarina state (Brazil). Correlations between the chemical composition, nanominerals, and ultrafine particles are discussed. Multifaceted physical-geochemical study provided a careful understanding of the nanomineralogical assemblage of the phosphogypsum waste. The electron beam investigation revealed the presence of many hazardous elements in the ultrafine particles. Cr, Pb, Mn, Se, Sr, and Zr, among others, were found in individual ultrafine particles and nanominerals in all studied samples. Besides that, rare earth elements were found in different concentration ranges, being Ce, La, and Nd, the rare earth elements, found in the higher concentrations, above 900 mg kg^-1. The data supplied by this article are important to characterize the phosphogypsum waste, assessing the potential hazard to the environment and human health, and also, provides information to enable the designing of alternatives to manage this waste.

Mercury sources in a subterranean spontaneous combustion area

Mercury is a toxic, persistent, and mobile contaminant. Coal spontaneous combustion are widely distributed in the world and releases a great deal of Hg. Identifying the burning coal seam is crucial for quickly extinguishing a coalfield fire. Mercury isotopes can be effective for identifying burning coal seams and beneficial for combating coal spontaneous combustion. In this study, Hg isotopic ratios of coal, topsoil, dustfall, sand, coal fire sponges (CFS), and n-topsoil (topsoil near the CFS) from coal fire area No. 9 in the Wuda coalfield were determined using multiple-collector inductively coupled plasma mass spectrometry (MC-ICPMS). Analysis of the correlation coefficients between the δ²⁰²Hg and Hg concentrations and the low-temperature ashes indicate that the higher mineral concentration in coal seam No. 9 not only increases the Hg concentration but also leads to more positive δ²⁰²Hg values compared to those for coal seam No. 10. By analyzing the Hg isotope characterizations in coal seam No. 9 and No. 10, we determined that Hg isotope characterizations can be useful for discriminating different coal seam Hg values in a coalfield. Significant mass-dependent fractionation (MDF) occur in the coal burning. The fractionation effect of burning and absorption process can play a key role in the δ²⁰²Hg more negative of ground surface samples. If Hg isotopes is added, the effect of coal-fire monitoring may be better. In addition, these finding could be used to better understand the transport and cycling of Hg.

Characterization of subsurface media from locations up- and down-gradient of a uranium-contaminated aquifer

The processing of sediment to accurately characterize the spatially-resolved depth profiles of geophysical and geochemical properties along with signatures of microbial density and activity remains a challenge especially in complex contaminated areas. This study processed cores from two sediment boreholes from background and contaminated core sediments and surrounding groundwater. Fresh core sediments were compared by depth to capture the changes in sediment structure, sediment minerals, biomass, and pore water geochemistry in terms of major and trace elements including pollutants, cations, anions, and organic acids. Soil porewater samples were matched to groundwater level, flow rate, and preferential flows and compared to homogenized groundwater-only samples from neighboring monitoring wells. Groundwater analysis of nearby wells only revealed high sulfate and nitrate concentrations while the same analysis using sediment pore water samples with depth was able to suggest areas high in sulfate- and nitrate-reducing bacteria based on their decreased concentration and production of reduced by-products that could not be seen in the groundwater samples. Positive correlations among porewater content, total organic carbon, trace metals and clay minerals revealed a more complicated relationship among contaminant, sediment texture, groundwater table, and biomass. The fluctuating capillary interface had high concentrations of Fe and Mn-oxides combined with trace elements including U, Th, Sr, Ba, Cu, and Co. This suggests the mobility of potentially hazardous elements, sediment structure, and biogeochemical factors are all linked together to impact microbial communities, emphasizing that solid interfaces play an important role in determining the abundance of bacteria in the sediments.

The association of subchronic exposure to low concentration of PM2.5 and high-fat diet potentiates glucose intolerance development, by impairing adipose tissue antioxidant defense and eHSP72 levels

The subchronic exposure to fine particulate matter (PM2.5) and high-fat diet (HFD) consumption lead to glucose intolerance by different mechanisms involving oxidative stress and inflammation. Under stressful conditions, the cells exert a heat shock response (HSR), by releasing the 72-kDa heat shock proteins (eHSP72), fundamental chaperones. The depletion of the HSR can exacerbate the chronic inflammation. However, there are few studies about the early effects of the association of HFD consumption and exposure to low concentrations of PM2.5 in the oxidative stress and HSR, in the genesis of glucose intolerance. Thus, we divided 23 male B6129SF2/J mice into control (n = 6), polluted (n = 6), HFD (n = 6), and high-fat diet + polluted (HFD + polluted) (n = 5) groups. Control and polluted received a standard diet (11.4% of fats), while HFD and HFD + polluted received HFD (58.3% of fats). Simultaneously, polluted and HFD + polluted received 5 μg/10 μL of PM2.5, daily, 7×/week, while control and HFD were exposed to 10 μL of saline solution 0.9% for 12 weeks. At the 12th week, animals were euthanized. We collected the metabolic tissues to analyze oxidative parameters, total blood to the hematological parameters, and plasma to eHSP72 measurement. The association of HFD and PM2.5 impaired glucose tolerance in the 12th week. Besides, it triggered an antioxidant defense by the adipose tissue, which was negatively correlated with eHSP72 levels. In conclusion, a low concentration of PM2.5 exposure associated with HFD consumption leads to glucose intolerance, by impairing adipose tissue antioxidant defense and systemic eHSP72 levels.

Implications of iron nanoparticles in spontaneous coal combustion and the effects on climatic variables

Atmosphere, water, and soil contamination with toxic compounds is a recurrent issue due to environmental disasters, coal burning, urbanization, and industrialization, allf of which have contributed to soil contamination over the decades. Consequently, understanding of the nanomineralogy and potential hazardous elements (PHEs) in coal area soil are always a vital topic since contaminated soil can affect the environment, agricultural safety, and human health. Colombian coal mining in the La Guajira zone has been usually been related with important health and ecological effects. Coalmine rejects from active and/or abandoned operations are causes of high intensities of potential hazardous elements (PHEs) and nanoparticles (NPs, minerals and/or amorphous compounds). Although these pollutants can be reduced by sorption to NPs, in this study was recognized an analytical procedure for understand distribution of PHEs and their relationship to iron NPs(Fe-NPs) was recognized. Non and poorrly crystalline Fe-NPs performances as the major PHEs association. This complex interaction is constant and efficient in resolving PHEs in proportions above monitoring quantities. The indefinite basis of PHEs in Colombian (La Guajira area) coalmine rejects sources results in years-long leaching of PHEs into rivers and drainages. The iron-clays and their great geomobility interfere the mitigating character that Fe hydr/oxides alone show through adsorption of PHEs and their control in spontaneous coal combustion (SCC) zones. This can have significant consequences to the probable availability of several pollutants (e.g. drinking water). The new results presented in this study add novel viewpoints into the description of Fe-NPs and its incidence in SCC areas. The methodology utilized in this work can be applied as a supplementary technique to evaluate the influence of coalmining actions on ecological and human health.

Geochemistry of potentially hazardous elements in loess-amended mining sediment

Contaminated mining sediment may cause environmental and human health risk due to potentially hazardous elements (PHEs) leaching into groundwater, especially under very acid (pH ≤ 3) conditions. The capability of Chinese loess to immobilise and retain copper (Cu), zinc (Zn), cadmium (Cd) and lead (Pb) from element contaminated mining sediment was explored by a column leaching experiment. Results showed that loess could effectively reduce Cu geomobility, and their leachate concentrations were lower than the quality standard (1.0 mg L^-1) for ground water in China. The sierozem showed strong adsorption for Zn, Cd and Pb. The geomobility of Cu, Zn, Cd and Pb were affected by pH, electrical conductivity, organic matter and carbonate content of sediment/loess-amended sediment and sierozem. The long-term leaching of PHEs in loess-amended sediment may pose a potential risk to sierozem and groundwater in the region. This study highlights the need to develop a remediation technique to minimise the concentration level of hazardous elements in the mining sediment.

Advance on toxicity of metal nickel nanoparticles

As a kind of conventional metal nanomaterial, nickel nanoparticles (Ni NPs) have broad application prospects in the fields of magnetism, energy technology and biomedicine and have quickly attracted great interest. The potential negative effects of Ni NPs have also attracted wide attention from some researchers. Studies have shown that Ni NPs cause a variety of toxic effects on cells, animals and humans and have toxic effects of multiple systems such as respiratory system, cardiovascular system and reproductive system. Ni NPs can lead to oxidative stress, apoptosis, DNA damage and inflammation and induce the increase of intracellular reactive oxygen species. The toxicity of Ni NPs is also found to be related to the mitogen-activated protein kinase pathway and the hypoxia inducible factor-1α pathway. Therefore, the toxicity and mechanism of Ni NPs are reviewed in this paper, and the future researches in this field are also proposed.

DNA double strand break repair as cellular response to genotoxic asarone isomers considering phase I metabolism

The phenylpropenes α-asarone and β-asarone are widely spread in the marsh plant Acorus calamus. Both isomers are classified as carcinogenic in rodents. However, the respective genotoxic mechanisms are not elucidated so far. The present study gives deeper insights into the genotoxic effects of asarone isomers as well as their known oxidative phase I metabolites, (E)-3'-oxoasarone and asarone epoxide. We show that asarone metabolites highly increase DNA strand breaks after 1 h of incubation, markedly metabolic activation contributes to their carcinogenic mode of action. All test compounds act as aneugens and potently enhance the amounts of micronuclei in binuclear cells. However, a prolonged incubation time of 24 h results in a decrease of DNA damage. This work suggests that asarone metabolites also induce DNA double strand breaks , why we put a strong focus on homologous recombination and non-homologous end joining. The obtained results herein indicate that asarone epoxide-induced DNA strand breaks are repaired via a homologous repair pathway.

A realistic study of 3D composition of carbon nanotubes and carbonaceous nanocompounds from different soils around coal power plant

Information on the effects of multi-walled carbon nanotubes (MWCNTs) on topsoil around coal power plants (CPPs) is still very limited. In the present work, the influences of MWCNTs on potential hazardous elements (PHEs) and environmental carbonaceous compounds in agrarian topsoil around CPPs of Latin America were investigated. The environmentally elevated proportions of MWCNTs and PHEs can cause damage to developing a fetus. The ecological impacts of industrial energy byproducts generated by MWCNTs were also studied. The surface morphologies of MWCNTs and PHEs detected in topsoil samples were analyzed by advanced electron microscopy in a combination of energy dispersive X-ray spectroscopy (EDS). The alterations could be originated due to the different geophysical constituents and superficial structure, which in turn disturbed their geoavailability in studied topsoil. It was found that a large amount of MWCNTs and amorphous carbonaceous matters, which are responsible for adsorbing PHEs, existed in soils around CPPs. Hence, these findings could be used to better understand the geochemical properties of PHEs near CPPs.

Increased risk of carotid atherosclerosis for long-term exposure to indoor coal-burning pollution in rural area, Hebei Province, China

Smoky coal burning is a predominant manner for heating and cooking in most rural areas, China. Air pollution is associated with the risk of atherosclerosis, however, the link between indoor air pollution induced by smoky coal burning and atherosclerosis is not very clear. Therefore, we designed a cross-sectional study to evaluate the association of long-term exposure to smoky coal burning pollutants with the risk of atherosclerosis. 426 and 326 participants were recruited from Nangong, China and assigned as the coal exposure and control group according to their heating and cooking way, respectively. The indoor air quality (PM2.5, CO, SO₂) was monitored. The association between coal burning exposure and the prevalence of atherosclerosis was evaluated by unconditional logistic regression analysis, adjusted for confounding factors. The inflammatory cytokines mRNAs (IL-8, SAA1, TNF-α, CRP) expression in whole blood were examined by qPCR. People in the coal exposure group had a higher risk of carotid atherosclerosis compared with the control (risk ratio [RR], 1.434; 95% confidence interval [95%CI], 1.063 to 1.934; P = 0.018). The association was stronger in smokers, drinkers and younger (<45 years old) individuals. The elevation of IL-8 (0.24, 95%CI, 0.06-0.58; P < 0.05), CRP (0.37, 95%CI, 0.05-0.70; P < 0.05), TNF-α (0.41, 95%CI, 0.14-0.67; P < 0.01) mRNAs expression in whole blood were positively related to coal exposure. Our results suggested long-term exposure to smoky coal burning emissions could increase the risk of carotid atherosclerosis. The potential mechanism might relate that coal burning emissions exposure induced inflammatory cytokines elevation which had adverse effects on atherosclerotic plaque, and then promoted the development of atherosclerosis.

Obesity associated with coal ash inhalation triggers systemic inflammation and oxidative damage in the hippocampus of rats

People with large amounts of adipose tissue are more vulnerable and more likely to develop diseases where oxidative stress and inflammation play a pivotal role, than persons with a healthy weight. Atmospheric contamination is a reality to which a large part of the worldwide population is exposed. Half of today's global electrical energy is derived from coal. Each organism, in its complexity, responds in different ways to dietary compounds and air pollution. The objective of this study was to investigate the effects of obesity and coal ash inhalation within the parameters of oxidative damage and inflammation in different regions of the brain of rats. A diet containing high-fat concentration was administered chronically to rats, along with exposure to coal ash, simulating the contamination that occurs daily throughout human life. High-resolution transmission electron microscopy was performed to identify the particles present in coal ash samples. Our results demonstrated that obese rats exposed to coal ash inhalation were more affected by oxidative damage with subsequent systemic inflammation in the hippocampus. Since there is an inflammatory predisposition caused by obesity, the inhalation of nanoparticles increases the levels of free radicals, resulting in systemic inflammation and oxidative damage, which can lead to chronic neurodegeneration.

Therapeutic potential of melatonin related to its role as an autophagy regulator: A review

There are several pathologies, syndromes, and physiological processes in which autophagy is involved. This process of self-digestion that cells trigger as a survival mechanism is complex and tightly regulated, according to the homeostatic conditions of the organ. However, in all cases, its relationship with oxidative stress alterations is evident, following a pathway that suggests endoplasmic reticulum stress and/or mitochondrial changes. There is accumulating evidence of the beneficial role that melatonin has in the regulation and restoration of damaged autophagic processes. In this review, we focus on major physiological changes such as aging and essential pathologies including cancer, neurodegenerative diseases, viral infections and obesity, and document the essential role of melatonin in the regulation of autophagy in each of these different situations.

Effects of macrophages and CXCR2 on adipogenic differentiation of bone marrow mesenchymal stem cells

Macrophages and many chemokines are closely associated with the adipogenic differentiation of bone marrow mesenchymal stem cells (MSCs), but their roles in adipogenesis and the underlying mechanisms are not fully understood. Here, we first investigated the influence of macrophages on the differentiation of MSCs in vitro. We found that RAW246.7 macrophages cocultured with MSCs strongly blocked the differentiation progress and inhibited the expression of C-X-C motif chemokine ligand 1 (CXCL1) during adipogenesis. Coculture with MSCs mainly induced macrophages toward M2 polarization. In addition, the expression of CXCL1 and its receptor, C-X-C chemokine receptor type 2, CXCR2 are high during adipogenic differentiation of MSCs and not in mature adipocytes. Although CXCL1 had no effect on adipogenesis, treatment with a specific CXCR2 inhibitor, SB225002, hampered the adipogenic differentiation of MSCs. Blocking CXCR2 decreased p38 and Elk1 phosphorylation but increased the extracellular signal-regulated kinase (ERK) phosphorylation at the initial stage of adipogenesis, which suppressed the phosphorylation of p38/ERK-Elk1 at the late stage. Inhibition of ERK had similar effects on adipogenesis and Elk1 phosphorylation. Our data suggest that MSCs interact with macrophages during adipogenic differentiation. CXCR2 regulates the adipogenic differentiation of MSCs by altering the activation of the p38/ERK-Elk1 signaling pathway.