Inhalation of environmental stressors & chronic inflammation: autoimmunity and neurodegeneration

Neuroplasticity Intervention, Amygdala and Insula Retraining (AIR), Significantly Improves Overall Health and Functioning Across Various Chronic Conditions

Chronic conditions, sometimes referred to as functional somatic disorders, such as myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), fibromyalgia (FM), and more recently, long COVID (LC), affect millions of people worldwide. Yet, after decades of research and testing, the etiology and treatment for many of these diseases is still unclear. Recently, a consortium of clinicians and researchers have proposed that while many different chronic conditions exist, the root cause of each may be a similar brain-body connection, as the brain responds to perceived biological threats and transmits danger signals to the body that manifest as somatic symptoms. This hypothesis suggests that treating chronic conditions requires an approach that addresses the neural networks involved. One such method, known as Amygdala and Insula Retraining (AIR), otherwise known as The Gupta Program, has shown promise in recent years for treating such conditions, including ME/CFS, FM, and LC. The present study aimed to demonstrate that AIR could be an effective approach for numerous other chronic illnesses (e.g., Lyme disease, mold illness, mast cell activation syndrome [MCAS]) and others. This novel and exploratory research examined self-reported health and functioning levels before and after using AIR. A series of paired-sample t tests with Bonferroni correction demonstrated that after 3+ months of using AIR (the minimum recommended time for the intervention), participants experienced a significant increase in overall health and functioning for 14 of 16 conditions tested (P < .001 for all but one, which was P = .001) and approached significance for the remaining two conditions (P = .039 and P = .005). Of the 14 signficant findings, 11 had a large effect size and three had a medium effect size. Naturally, this study has limitations. It was a cross-sectional design with a small convenience sample and self-reported data. Future research with larger samples and randomized controlled trials is needed to provide further evidence of AIR's effectiveness. Nonetheless, these preliminary findings suggest that AIR is a viable method for improving the health of people suffering from chronic conditions, and clinicians and researchers might consider incorporating AIR into their protocols for these patients.

Hazard, Distribution and Exposure of Particulate Pollution from Indoor and Outdoor Environments

Air is an essential natural resource for life [...].

Preliminary Toxicological Analysis in a Safe-by-Design and Adverse Outcome Pathway-Driven Approach on Different Silver Nanoparticles: Assessment of Acute Responses in A549 Cells

Silver nanoparticles (Ag NPs) are among the most widely used metal-based nanomaterials (NMs) and their applications in different products, also as antibacterial additives, are increasing. In the present manuscript, according to an adverse outcome pathway (AOP) approach, we tested two safe-by-design (SbD) newly developed Ag NPs coated with hydroxyethyl cellulose (HEC), namely AgHEC powder and AgHEC solution. These novel Ag NPs were compared to two reference Ag NPs (naked and coated with polyvinylpyrrolidone-PVP). Cell viability, inflammatory response, reactive oxygen species, oxidative DNA damage, cell cycle, and cell-particle interactions were analyzed in the alveolar in vitro model, A549 cells. The results show a different toxicity pattern of the novel Ag NPs compared to reference NPs and that between the two novel NPs, the AgHEC solution is the one with the lower toxicity and to be further developed within the SbD framework.

Genotoxicity of Natural Water during the Mass Development of Cyanobacteria Evaluated by the Allium Test Method: A Model Experiment with Microcosms

Cyanobacteria, which develop abundantly in aquatic ecosystems, can be harmful to humans and animals not only by releasing toxins that cause poisoning but also by provoking cytogenetic effects. The influence of the mass development of cyanobacteria on the genotoxic properties of natural water has been studied in model ecosystems (microcosms) with different compositions of biotic components (zooplankton, amphipods and fish). The validated plant test system “Allium test” was used in this study. Genotoxic effects were detected at microcystin concentrations below those established by the World Health Organization (WHO) for drinking water. In all experimental treatments, cells with disorders such as polyploidy and mitotic abnormalities associated with damage to the mitotic spindle, including c-mitosis, as well as lagging chromosomes were found. Genotoxic effects were associated with the abundance of cyanobacteria, which, in turn, depended on the composition of aquatic organisms in the experimental ecosystem. Fish, to a greater extent than other aquatic animals, maintain an abundance of cyanobacteria. After one month, in microcosms with fish, mitotic abnormalities and polyploidy continued to be detected, whereas in other treatments, there were no statistically significant genotoxic effects. In microcosms with amphipods, the number and biomass of cyanobacteria decreased to the greatest extent, and only one parameter of genotoxic activity (frequency of polyploidy) significantly differed from the control.

The impact of chronic exposure to air pollution over oxidative stress parameters and brain histology

Air pollution (AP) triggers neuroinflammation and lipoperoxidation involved in physiopathology of several neurodegenerative diseases. Our study aims to investigate the effect of chronic exposure to ambient AP in oxidative stress (OS) parameters and number of neurons and microglial cells of the cortex and striatum. Seventy-two male Wistar rats were distributed in four groups of exposure: control group (FA), exposed throughout life to filtered air; group PA-FA, pre-natal exposed to polluted air until weaning and then to filtered air; group FA-PA, pre-natal exposed to filtered air until weaning and then to polluted air; and group PA, exposed throughout life to polluted air. After 150 days of exposure, the rats were euthanized for biochemical and histological determinations. The malondialdehyde concentration in the cortex and striatum was significantly higher in the PA group. The activity of superoxide dismutase was significantly decreased in the cortex of all groups exposed to AP while activity of catalase was not modified in the cortex or striatum. The total glutathione concentration was lower in the cortex and higher in the striatum of the FA-PA group. The number of neurons or microglia in the striatum did not differ between FA and PA. On the other hand, neurons and microglia cell numbers were significantly higher in the cortex of the FA-PA group. Our findings suggest that the striatum and cortex have dissimilar thresholds to react to AP exposure and different adaptable responses to chronically AP-induced OS. At least for the cortex, changing to a non-polluted ambient early in life was able to avoid and/or reverse the OS, although some alterations in enzymatic antioxidant system may be permanent. As a result, it is important to clarify the effects of AP in the cortical organization and function because of limited capacity of brain tissue to deal with threatening environments.

Chronic Manganese Exposure and the Enteric Nervous System: An in Vitro and Mouse in Vivo Study

BACKGROUND

Chronic environmental exposure to manganese (Mn) can cause debilitating damage to the central nervous system. However, its potential toxic effects on the enteric nervous system (ENS) have yet to be assessed.

OBJECTIVE

We examined the effect of Mn on the ENS using both cell and animal models.

METHOD

Rat enteric glial cells (EGCs) and mouse primary enteric cultures were exposed to increasing concentrations of Mn and cell viability and mitochondrial health were assessed using various morphological and functional assays. C57BL/6 mice were exposed daily to a sublethal dose of Mn (15mg/kg/d) for 30 d. Gut peristalsis, enteric inflammation, gut microbiome profile, and fecal metabolite composition were assessed at the end of exposure.

RESULTS

EGC mitochondria were highly susceptible to Mn neurotoxicity, as evidenced by lower mitochondrial mass, adenosine triphosphate-linked respiration, and aconitase activity as well as higher mitochondrial superoxide, upon Mn exposure. Minor differences were seen in the mouse model: specifically, longer intestinal transit times and higher levels of colonic inflammation.

CONCLUSION

Based on our findings from this study, Mn preferentially induced mitochondrial dysfunction in a rat EGC line and in vivo resulted in inflammation in the ENS. https://doi.org/10.1289/EHP7877.

Pulmonary Neutrophilic Inflammation and Noncommunicable Diseases: Pathophysiology, Redox Mechanisms, Biomarkers, and Therapeutics

Significance: Pulmonary neurophilic inflammation (PNI) is the homing and activation of neutrophil with damage to the microvasculature. This process is involved in pulmonary damage in patients exposed to airborne pollutants (exogenous stressors) and also to systemic inflammation/oxidative stress (endogenous stressors) associated with noncommunicable diseases (NCDs). Recent Advances: PNI is an important trigger of the early onset and progression of NCD in susceptible patients exposed to airborne pollutants. Irritation of the lung microvasculature by exogenous and endogenous stressors causes PNI. Circulating endogenous stressors in NCD can cause PNI. Critical Issues: Air pollution-triggered PNI causes increased circulating endogenous stressors that can trigger NCD in susceptible patients. Systemic inflammation/oxidative stress associated with NCD can cause PNI. Inflammation/end-oxidation products of macromolecules are also potential biomarkers and therapeutic targets for NCD-triggered PNI- and PNI-triggered NCD. Future Directions: Understanding the molecular mechanism of PNI triggered by exogenous or endogenous stressors will help explain the early onset of NCD in susceptible patients exposed to air pollution. It can also help undercover biomarkers and mechanism-based therapeutic targets in air pollutant-triggered PNI, PNI-triggered NCD, and NCD-triggered PNI.

The epitranscriptomic writer ALKBH8 drives tolerance and protects mouse lungs from the environmental pollutant naphthalene

The epitranscriptomic writer Alkylation Repair Homolog 8 (ALKBH8) is a transfer RNA (tRNA) methyltransferase that modifies the wobble uridine of selenocysteine tRNA to promote the specialized translation of selenoproteins. Using Alkbh8 deficient (Alkbh8^def) mice, we have investigated the importance of epitranscriptomic systems in the response to naphthalene, an abundant polycyclic aromatic hydrocarbon and environmental toxicant. We performed basal lung analysis and naphthalene exposure studies using wild type (WT), Alkbh8^{de f} and Cyp2abfgs-null mice, the latter of which lack the cytochrome P450 enzymes required for naphthalene bioactivation. Under basal conditions, lungs from Alkbh8^def mice have increased markers of oxidative stress and decreased thioredoxin reductase protein levels, and have reprogrammed gene expression to differentially regulate stress response transcripts. Alkbh8^def mice are more sensitive to naphthalene induced death than WT, showing higher susceptibility to lung damage at the cellular and molecular levels. Further, WT mice develop a tolerance to naphthalene after 3 days, defined as resistance to a high challenging dose after repeated exposures, which is absent in Alkbh8^def mice. We conclude that the epitranscriptomic writer ALKBH8 plays a protective role against naphthalene-induced lung dysfunction and promotes naphthalene tolerance. Our work provides an early example of how epitranscriptomic systems can regulate the response to environmental stress in vivo.

Aging Exacerbates Neuroinflammatory Outcomes Induced by Acute Ozone Exposure

The role of environmental stressors, particularly exposure to air pollution, in the development of neurodegenerative disease remains underappreciated. We examined the neurological effects of acute ozone (O3) exposure in aged mice, where increased blood-brain barrier (BBB) permeability may confer vulnerability to neuroinflammatory outcomes. C57BL/6 male mice, aged 8-10 weeks or 12-18 months were exposed to either filtered air or 1.0 ppm O3 for 4 h; animals received a single IP injection of sodium fluorescein (FSCN) 20 h postexposure. One-hour post-FSCN injection, animals were transcardially perfused for immunohistochemical analysis of BBB permeability. β-amyloid protein expression was assessed via ELISA. Flow cytometric characterization of infiltrating immune cells, including neutrophils, macrophages, and microglia populations was performed 20 h post-O3 exposure. Flow cytometry analysis of brains revealed increased microglia "activation" and presentation of CD11b, F4/80, and MHCII in aged animals relative to younger ones; these age-induced differences were potentiated by acute O3 exposure. Cortical and limbic regions in aged brains had increased reactive microgliosis and β-amyloid protein expression after O3 insult. The aged cerebellum was particularly vulnerable to acute O3 exposure with increased populations of infiltrating neutrophils, peripheral macrophages/monocytes, and Ly6C+ inflammatory monocytes after insult, which were not significantly increased in the young cerebellum. O3 exposure increased the penetration of FSCN beyond the BBB, the infiltration of peripheral immune cells, and reactive gliosis of microglia. Thus, the aged BBB is vulnerable to insult and becomes highly penetrable in response to O3 exposure, leading to greater neuroinflammatory outcomes.

Ambient urban dust particulate matter reduces pathologic T cells in the CNS and severity of EAE

BACKGROUND

Autoimmune diseases have increased in incidence and prevalence worldwide. While genetic predispositions play a role, environmental factors are a major contributor. Atmospheric particulate matter (PM) is a complex mixture composed of metals, nitrates, sulfates and diverse adsorbed organic compounds like polycyclic aromatic hydrocarbons (PAHs) and dioxins. Exposure to atmospheric PM aggravates autoimmune diseases such as type 1 diabetes, rheumatoid arthritis, multiple sclerosis, and systemic lupus erythematosus, among others. PAHs and dioxins are known aryl hydrocarbon receptor (AHR) ligands. The AHR modulates T cell differentiation and directs the balance between effector and regulatory T cells in vitro and in experimental autoimmune encephalomyelitis (EAE), a murine model of autoimmune disease. This study aims to identify pathways that contribute to autoimmune disease and their potential use as therapeutic targets to alleviate symptoms and the need for global immunosuppression. This study tests the hypothesis that atmospheric PM enhances effector T cell differentiation and aggravates autoimmune disease.

RESULTS

An atmospheric ambient urban dust PM sample, standard reference material (SRM)1649b, was tested for its effects on autoimmunity. SRM1649b PM enhanced Th17 differentiation in an AHR-dependent manner in vitro, however intranasal treatment of SRM1649b PM delayed onset of EAE and reduced cumulative and peak clinical scores. Chronic and acute intranasal exposure of SRM1649b PM delayed onset of EAE. Chronic intranasal exposure did not reduce severity of EAE while acute intranasal exposure significantly reduced severity of disease. Acute intranasal treatment of low dose SRM1649b PM had no effect on clinical score or day of onset in EAE. Delayed onset of EAE by intranasal SRM1649b PM was AHR-dependent in vivo. Oral gavage of SRM1649b PM, in the absence of AHR ligands in the diet, had no effect on day of disease onset or severity of EAE. Day 10 analysis of T cells in the CNS after intranasal treatment of SRM1649b PM showed a reduction of pathologic T cell subsets in vivo. Moreover, MOG-specific splenocytes require AHR to generate or maintain IL-10 producing cells and reduce IFNγ producing cells in vitro.

CONCLUSIONS

These results identify the AHR pathway as a potential target for driving targeted immunosuppression in the CNS in the context of atmospheric PM-mediated autoimmune disease. The effects of SRM1649b PM on EAE are dependent on route of exposure, with intranasal treatment reducing severity of EAE and delaying disease onset while oral gavage has no effect. Intranasal SRM1649b PM reduces pathologic T cells in the CNS, specifically Th1 cells and Th1Th17 double positive cells, leading to reduced severity of EAE and AHR-dependent delayed disease onset. Additionally, SRM1649b PM treatment of antigen-specific T cells leads to AHR-dependent increase in percent IL-10 positive cells in vitro. These findings may shed light on the known increase of infection after exposure to atmospheric PM and serve as the first step in identifying components of the AHR pathway responsible for Th1-mediated immunosuppression in response to atmospheric PM exposure.

Air pollution, oxidative stress, and exacerbation of autoimmune diseases

A number of epidemiological studies have shown a strong association between exposure to ambient airborne particulate matter (PM 2.5, PM < 1.0) and lung or cardiovascular diseases characterised by high mortality and morbidity. However, much less is known about the role of air pollution in the pathogenesis of autoimmune diseases, which constitutes a significant problem in modern society. This paper summarises the state of current research regarding the influence of PM on the development and/or progression of autoimmune diseases. A brief review of the great body of research concerning pathogenesis of autoimmune disorders is presented. Then, the scope of our review is narrowed to the research related to the impact of particulate matter on oxidative and nitrosative stress, as well as exacerbation of chronic inflammation, because they can contribute to the development of autoimmune diseases. Moreover, we discuss the impact of various components of PM (metal, organic compounds) on PM toxicity and the ability to generate oxidants.

Air pollution and respiratory health among diabetic and non-diabetic subjects in Pune, India-results from the Wellcome Trust Genetic Study

Diabetics may be more vulnerable to the harmful effects of ambient air pollutants than healthy individuals. But, the risk factors that lead to susceptibility to air pollution in diabetics have not yet been identified. We examined the effect of exposure to ambient PM₁₀ on chronic symptoms and the pulmonary function tests (PFT) in diabetic and non-diabetic subjects. Also, to investigate possible determinants of susceptibility, we recruited 400 type 2 diabetic and 465 healthy subjects who were investigated for chronic respiratory symptoms (CRSs) and then underwent measurement of forced vital capacity (FVC) and forced expiratory volume 1 (FEV1) according to standard protocol. Percent predicted FEV1 and FVC (FEV1% and FVC%, respectively) for each subject were calculated. Particulate matter (PM₁₀) concentrations at residence place of subjects were estimated using AERMOD dispersion model. The association between PM₁₀ and CRSs was explored using logistic regression. We also used linear regression models controlling for potential confounders to study the association between chronic exposure to PM₁₀ and FEV1% and FVC%. Prevalence of current wheezing, allergy symptom, chest tightness, FEV1/FVC <70%, and physician-diagnosed asthma and COPD was significantly higher among diabetic subjects than non-diabetics. There was no significant difference between percent predicted value of PFT among diabetic and non-diabetic subjects (P < 0.05). We estimated that 1 SD increase in PM₁₀ concentration was associated with a greater risk of having dyspnea by 1.50-fold (95% CI, 1.12-2.01). Higher exposure to PM₁₀ concentration was also significantly associated with lower FVC%. The size of effect for 1 SD μg/m³ (=98.38) increase in PM₁₀ concentration was 3.71% (95% CI, 0.48-4.99) decrease in FVC%. In addition, we indicated that strength of these associations was higher in overweight, smoker, and aged persons. We demonstrated a possible contribution of air pollution to reduced lung function independent of diabetes status. This study suggests that decline in exposure may significantly reduce disease manifestation as dyspnea and impaired lung function. We conduct that higher BMI, smoking, and older age were associated with higher levels of air pollution effects.

Inhibition of endocytic lipid antigen presentation by common lipophilic environmental pollutants

Environmental pollutants as non-heritable factors are now recognized as triggers for multiple human inflammatory diseases involving T cells. We postulated that lipid antigen presentation mediated by cluster of differentiation 1 (CD1) proteins for T cell activation is susceptible to lipophilic environmental pollutants. To test this notion, we determined whether the common lipophilic pollutants benzo[a]pyrene and diesel exhaust particles impact on the activation of lipid-specific T cells. Our results demonstrated that the expression of CD1a and CD1d proteins, and the activation of CD1a- and CD1d-restricted T cells were sensitively inhibited by benzo[a]pyrene even at the low concentrations detectable in exposed human populations. Similarly, diesel exhaust particles showed a marginal inhibitory effect. Using transcriptomic profiling, we discovered that the gene expression for regulating endocytic and lipid metabolic pathways was perturbed by benzo[a]pyrene. Imaging flow cytometry also showed that CD1a and CD1d proteins were retained in early and late endosomal compartments, respectively, supporting an impaired endocytic lipid antigen presentation for T cell activation upon benzo[a]pyrene exposure. This work conceptually demonstrates that lipid antigen presentation for T cell activation is inhibited by lipophilic pollutants through profound interference with gene expression and endocytic function, likely further disrupting regulatory cytokine secretion and ultimately exacerbating inflammatory diseases.

AhR and Arnt differentially regulate NF-κB signaling and chemokine responses in human bronchial epithelial cells

Background

The aryl hydrocarbon receptor (AhR) has gradually emerged as a regulator of inflammation in the lung and other tissues. AhR may interact with the p65-subunit of the nuclear factor (NF)-κB transcription factors, but reported outcomes of AhR/NF-κB-interactions are conflicting. Some studies suggest that AhR possess pro-inflammatory activities while others suggest that AhR may be anti-inflammatory. The present study explored the impact of AhR and its binding partner AhR nuclear translocator (Arnt) on p65-activation and two differentially regulated chemokines, CXCL8 (IL-8) and CCL5 (RANTES), in human bronchial epithelial cells (BEAS-2B).

Results

Cells were exposed to CXCL8- and CCL5-inducing chemicals, 1-nitropyrene (1-NP) and 1-aminopyrene (1-AP) respectively, or the synthetic double-stranded RNA analogue, polyinosinic-polycytidylic acid (Poly I:C) which induced both chemokines. Only CXCL8, and not CCL5, appeared to be p65-dependent. Yet, constitutively active unligated AhR suppressed both CXCL8 and CCL5, as shown by siRNA knock-down and the AhR antagonist α-naphthoflavone. Moreover, AhR suppressed activation of p65 by TNF-α and Poly I:C as assessed by luciferase-assay and p65-phosphorylation at serine 536, without affecting basal p65-activity. In contrast, Arnt suppressed only CXCL8, but did not prevent the p65-activation directly. However, Arnt suppressed expression of the NF-κB-subunit RelB which is under transcriptional regulation by p65. Furthermore, AhR-ligands alone at high concentrations induced a moderate CXCL8-response, without affecting CCL5, but suppressed both CXCL8 and CCL5-responses by Poly I:C.

Conclusion

AhR and Arnt may differentially and independently regulate chemokine-responses induced by both inhaled pollutants and pulmonary infections. Constitutively active, unligated AhR suppressed the activation of p65, while Arnt may possibly interfere with the action of activated p65. Moreover, ligand-activated AhR suppressed CXCL8 and CCL5 responses by other agents, but AhR ligands alone induced CXCL8 responses when given at sufficiently high concentrations, thus underscoring the duality of AhR in regulation of inflammation. We propose that AhR-signaling may be a weak activator of p65-signaling that suppresses p65-activity induced by strong activators of NF-κB, but that its anti-inflammatory properties also are due to interference with additional pathways.

Socioeconomic status and exposure to outdoor NO2 and benzene in the Asturias INMA birth cohort, Spain

Background

It is commonly assumed that low socioeconomic levels are associated with greater exposure to pollution, but this is not necessarily valid. Our goal was to examine how individual socioeconomic characteristics are associated with exposure levels in a Spanish region included in the INfancia y Medio Ambiente (INMA) cohort.

Methods

The study population comprised 430 pregnant women from the Asturias INMA cohort. Air pollution exposure was estimated using land-use regression techniques. Information about the participants’ lifestyle and socioeconomic variables was collected through questionnaires. In multivariate analysis, the levels of NO₂ and benzene assigned to each woman were considered as dependent variables. Other variables included in the models were residential zone, age, education, parity, smoking, season, working status during pregnancy and social class.

Results

The average NO₂ level was 23.60 (SD=6.50) μg/m³. For benzene, the mean value was 2.31 (SD=1.32) μg/m³. We found no association of any pollutant with education. We observed an association between social class and benzene levels. Social classes I and II had the highest levels. The analysed socioeconomic and lifestyle variables accounted for little variability in air pollution in the models; this variability was explained mainly by residential zone (adjusted R²: 0.27 for NO₂; 0.09 for benzene).

Conclusions

Education and social class were not clearly associated with pollution. Administrations should monitor the environment of residential areas regardless of the socioeconomic level, and they should increase the distances between housing and polluting sources to prevent settlements at distances that are harmful to health.

Environmental determinants of chronic disease and medical approaches: recognition, avoidance, supportive therapy, and detoxification

The World Health Organization warns that chronic, noncommunicable diseases are rapidly becoming epidemic worldwide. Escalating rates of neurocognitive, metabolic, autoimmune and cardiovascular diseases cannot be ascribed only to genetics, lifestyle, and nutrition; early life and ongoing exposures, and bioaccumulated toxicants may also cause chronic disease. Contributors to ill health are summarized from multiple perspectives--biological effects of classes of toxicants, mechanisms of toxicity, and a synthesis of toxic contributors to major diseases. Healthcare practitioners have wide-ranging roles in addressing environmental factors in policy and public health and clinical practice. Public health initiatives include risk recognition and chemical assessment then exposure reduction, remediation, monitoring, and avoidance. The complex web of disease and environmental contributors is amenable to some straightforward clinical approaches addressing multiple toxicants. Widely applicable strategies include nutrition and supplements to counter toxic effects and to support metabolism; as well as exercise and sweating, and possibly medication to enhance excretion. Addressing environmental health and contributors to chronic disease has broad implications for society, with large potential benefits from improved health and productivity.

8-Oxoguanine-DNA glycosylase 1 deficiency modifies allergic airway inflammation by regulating STAT6 and IL-4 in cells and in mice

8-Oxoguanine-DNA glycosylase (OGG-1) is a base excision DNA repair enzyme; however, its function in modulating allergic diseases remains undefined. Using OGG-1 knockout (KO) mice, we show that this protein affects allergic airway inflammation after sensitization and challenge by ovalbumin(OVA). OGG-1 KO mice exhibited less inflammatory cell infiltration and reduced oxidative stress in the lungs after OVA challenge compared to WT mice. The KO phenotype included decreased IL-4, IL-6, IL-10, and IL-17 in lung tissues. In addition, OGG-1 KO mice showed decreased expression and phosphorylation of STAT6 as well as NF-κB. Down-regulation of OGG-1 by siRNA lowered ROS and IL-4 levels but increased IFN-γ production in cultured epithelial cells after exposure to house dust mite extracts. OGG-1 may affect the levels of oxidative stress and proinflammatory cytokines during asthmatic conditions. OGG-1 deficiency negatively regulates allergen-induced airway inflammatory response.

Cancer surgery in the elderly

The proportions both of elderly patients in the world and of elderly patients with cancer are both increasing. In the evaluation of these patients, physiologic age, and not chronologic age, should be carefully considered in the decision-making process prior to both cancer screening and cancer treatment in an effort to avoid ageism. Many tools exist to help the practitioner determine the physiologic age of the patient, which allows for more appropriate and more individualized risk stratification, both in the pre- and postoperative periods as patients are evaluated for surgical treatments and monitored for surgical complications, respectively. During and after operations in the oncogeriatric populations, physiologic changes occuring that accompany aging include impaired stress response, increased senescence, and decreased immunity, all three of which impact the risk/benefit ratio associated with cancer surgery in the elderly.

Non-nutrient causes of low-grade, systemic inflammation: support for a 'canary in the mineshaft' view of obesity in chronic disease

A form of low-grade, systemic inflammation ('metaflammation') is linked to many types of chronic disease. Initially, this was thought to be causally related to weight gain and obesity and a possible explanation of the link between obesity and disease. However, several lifestyle-related inducers of such inflammation, some of which are associated with obesity, but some of which are not, have now been identified. The most common of these have been nutritive related, suggesting that there could still be a relationship, either directly or indirectly, with obesity. Here we provide evidence for non-nutritive inflammatory inducers, providing further support for an earlier suggestion that while obesity, beyond a point, may have a direct link with disease, this may be neither necessary nor sufficient to explain the current epidemic of chronic disease. A more ubiquitous cause encompassing all inflammatory inducers is the modern, post-industrial environment and lifestyles emanating from this. Obesity may thus be more of 'a canary in the mineshaft', warning of bigger global problems, than just a single pathway to modern environmentally driven disease.

Airborne particulate matter selectively activates endoplasmic reticulum stress response in the lung and liver tissues

Recent studies have suggested a link between inhaled particulate matter (PM) exposure and increased mortality and morbidity associated with pulmonary and cardiovascular diseases. However, a precise understanding of the biological mechanism underlying PM-associated toxicity and pathogenesis remains elusive. Here, we investigated the impact of PM exposure in intracellular stress signaling pathways with animal models and cultured cells. Inhalation exposure of the mice to environmentally relevant fine particulate matter (aerodynamic diameter < 2.5 μm, PM(2.5)) induces endoplasmic reticulum (ER) stress and activation of unfolded protein response (UPR) in the lung and liver tissues as well as in the mouse macrophage cell line RAW264.7. Ambient PM(2.5) exposure activates double-strand RNA-activated protein kinase-like ER kinase (PERK), leading to phosphorylation of translation initiation factor eIF2α and induction of C/EBP homologous transcription factor CHOP/GADD153. Activation of PERK-mediated UPR pathway relies on the production of reactive oxygen species (ROS) and is critical for PM(2.5)-induced apoptosis. Furthermore, PM(2.5) exposure can activate ER stress sensor IRE1α, but it decreases the activity of IRE1α in splicing the mRNA encoding the UPR trans-activator X-box binding protein 1 (XBP1). Together, our study suggests that PM(2.5) exposure differentially activates the UPR branches, leading to ER stress-induced apoptosis through the PERK-eIF2α-CHOP UPR branch. This work provides novel insights into the cellular and molecular basis by which ambient PM(2.5) exposure elicits its cytotoxic effects that may be related to air pollution-associated pathogenesis.

Ozone modulates the effects of imipramine on immobility in the forced swim test, and nonspecific parameters of hippocampal oxidative stress in the rat

Depression has been associated with oxidative stress. There is increased awareness of the role of environmental toxins in the development of mood disorders. Ozone, a pro-oxidant and environmental pollutant, has been noted to have central nervous system effects. We investigated the effects of acute and chronic ozone inhalation on the response of imipramine in the forced-swim test (FST) and on biomarkers of oxidative stress in rat hippocampus. Sprague Dawley rats were exposed to 0, 0.25 or 0.7 ppm ozone per inhalation 4 h daily for either 30 days (chronic) or once (acute). Animals were then injected intraperitoneally with imipramine (10 mg/kg) or saline 24, 5 and 1 h before the forced-swim test. Hippocampal superoxide accumulation and lipid peroxidation were measured. Imipramine evoked an antidepressant-like effect independent of acute or chronic ozone exposure. However, 0.7 ppm acute ozone and 0.25 ppm chronic ozone attenuated the antidepressant-like effects of imipramine. The ozone exposures also elevated hippocampal superoxide accumulation and lipid peroxidation. Importantly, imipramine reversed the lipid peroxidation induced by chronic ozone, thereby preventing cellular damage induced by oxidative stress. Ozone exposure presents a feasible model with etiological validity to investigate oxidative stress in depression and antidepressant action.

Real-world exposure of airborne particulate matter triggers oxidative stress in an animal model

Epidemiological studies have shown a strong link between air pollution and the increase of cardio-pulmonary mortality and morbidity. In particular, inhaled airborne particulate matter (PM) exposure is closely associated with the pathogenesis of air pollution-induced systemic diseases. In this study, we exposed C57BIV6 mice to environmentally relevant PM in fine and ultra fine ranges (diameter < 2.5 μm, PM(2.5)) using a "real-world" airborne PM exposure system. We investigated the pathophysiologic impact of PM(2.5) exposure in the animal model and in cultured primary pulmonary macrophages. We demonstrated that PM(2.5) exposure increased the production of reactive oxygen species (ROS) in blood vessels in vivo. Furthermore, in vitro PM(2.5) exposure experiment suggested that PM(2.5) could trigger oxidative stress response, reflected by an increased expression of the anti-oxidative stress enzymes superoxide dismutase-1 (SOD-1) and heme oxygenase-1(HO-1), in mouse primary macrophages. Together, the results obtained through our "real-world" PM exposure approach demonstrated the pathophysiologic effect of ambient PM(2.5) exposure on triggering oxidative stress in the specialized organ and cell type of an animal model. Our results and approach will be informative for the research in air pollution-associated physiology and pathology.

The immune effects of naturally occurring and synthetic nanoparticles

Ultrafine particles and engineered nanoparticles have unique aerodynamic and biochemical properties that affect the immune system and human health in ways that are different from or exceed those seen with gases or larger particulates. These effects result from a unique set of physical characteristics and surface moieties, which generate an ability of UFPs to enter tissues and cells, interact with proteins and DNA at a molecular level and directly and indirectly modulate the immune system by novel mechanisms. In recent years, a new field known as nanotechnology has impacted multiple industries by taking advantage of the special qualities of these small "atomic-sized" particles. Nanomedicine has already opened up a new avenue of research in cancer therapy, drug delivery and immune regulation. While the benefits of this new science to human civilization are seemingly immeasurable, it is also important to appreciate that these particles can also lead to harmful effects on human health. In vitro and animal studies are showing that nanoparticles and UFPs are capable of activating proinflammatory cytokines, chemokines and adhesion molecules, with recruitment of inflammatory cells including basophils, macrophages, dendritic cells, T cells, neutrophils and eosinophils. These changes may have an impact on immune defense, but also on the Th1/Th2 balance, and even on non-immunologic function. Resulting immune system derangement can lead to increases in incidence of autoimmune, allergic and even neoplastic diseases. Cardiorespiratory effects have been observed to occur in humans. Much further research is needed to establish safe exposure levels for this important new class of particulates.

A predictive toxicological paradigm for the safety assessment of nanomaterials

The rate of expansion of nanomaterials calls for the consideration of appropriate toxicological paradigms in the safety assessment of nanomaterials. We advocate a predictive toxicological paradigm for the assessment of nanomaterial hazards. The predictive toxicological approach is defined as establishing and using mechanisms and pathways of injury at a cellular and molecular level to prioritize screening for adverse biological effects and health outcomes in vivo. Specifically as it relates to nanomaterials, a predictive approach has to consider the physicochemical properties of the material that leads to molecular or cellular injury and also has to be valid in terms of disease pathogenesis in whole organisms.

Moving towards making social toxins mainstream in children's environmental health

PURPOSE OF REVIEW

Although traditional disciplinary research theory and methods have focused separately on how social and physical environmental factors affect children's health, evolving research underscores important integrated effects.

RECENT FINDINGS

This review outlines the specific reasons why social determinants should be considered mainstream in children's environmental health research with particular focus on interactive effects between social and physical hazards. These include sensitivity of overlapping physiological systems, via epigenesis, programming, and plasticity to social and physical environmental moderation that may impact health across the life span; ways in which social environmental vulnerabilities moderate the effects of physical environmental factors, providing specific examples related to respiratory health and neurodevelopment; overlapping exposure distribution profiles; and relevance to pediatric health disparities.

SUMMARY

Because of the covariance across exposures, and evidence that social stress and other environmental toxins (e.g., pollutants, tobacco smoke) may influence common physiological pathways (e.g., oxidative stress, proinflammatory immune pathways, autonomic disruption), understanding the potential synergistic effects promises to more completely inform children's environmental health risk. Although this discussion focuses around the respiratory and neurological systems, these concepts extend more broadly to children's psychological and physical development.