Sex and strain-based inflammatory response to repeated tobacco smoke exposure in spontaneously hypertensive and Wistar Kyoto rats

Lifestyle and demographic associations with 47 inflammatory and vascular stress biomarkers in 9876 blood donors

BACKGROUND

The emerging use of biomarkers in research and tailored care introduces a need for information about the association between biomarkers and basic demographics and lifestyle factors revealing expectable concentrations in healthy individuals while considering general demographic differences.

METHODS

A selection of 47 biomarkers, including markers of inflammation and vascular stress, were measured in plasma samples from 9876 Danish Blood Donor Study participants. Using regression models, we examined the association between biomarkers and sex, age, Body Mass Index (BMI), and smoking.

RESULTS

Here we show that concentrations of inflammation and vascular stress biomarkers generally increase with higher age, BMI, and smoking. Sex-specific effects are observed for multiple biomarkers.

CONCLUSION

This study provides comprehensive information on concentrations of 47 plasma biomarkers in healthy individuals. The study emphasizes that knowledge about biomarker concentrations in healthy individuals is critical for improved understanding of disease pathology and for tailored care and decision support tools.

Comparison of the effects of active and passive smoking of tobacco cigarettes, electronic nicotine delivery systems and tobacco heating products on the expression and secretion of oxidative stress and inflammatory response markers. A systematic review

OBJECTIVES

This work attempts to summarize current knowledge on the effects of active and passive smoking of cigarettes, electronic nicotine delivery systems and tobacco heating products on the expression and secretion of oxidative stress and inflammatory response mediators, and on their possible impact on chronic obstructive pulmonary disease development.

MATERIALS AND METHODS

The literature was searched by the terms: 'smoking', 'active smoking', 'passive smoking', 'main-stream smoke', 'side-stream smoke', 'secondhand smoke', 'cigarette' 'THP', 'tobacco heating product', 'ENDS', 'electronic nicotine delivery system', 'e-cigarette', 'electronic cigarette', oxidative stress', inflammatory response' and 'gene expression'.

RESULTS

Cigarette smoking (active and passive) induces oxidative stress and inflammatory response in the airways. We present the effect of active smoking of e-cigarettes (EC) and heat-not-burn (HnB) products on the increased expression and secretion of oxidative stress and inflammatory response markers. However, there is only a limited number of studies on the effect of their second-hand smoking, and those available mainly describe aerosol composition.

DISCUSSION

The literature provides data which confirm that active and passive cigarette smoking induces oxidative stress and inflammatory response in the airways and is a key risk factor of COPD development. Currently, there is a limited number of data about ENDS and THP active and passive smoking effects on the health of smokers and never-smokers. It is particularly important to assess the effect of such products during long-term use by never-smokers who choose them as the first type of cigarettes, and for never-smokers who are passively exposed to their aerosol.

Influence of Mild Chronic Stress and Social Isolation on Acute Ozone-Induced Alterations in Stress Biomarkers and Brain-Region-Specific Gene Expression in Male Wistar-Kyoto Rats

Individuals with psychosocial stress often experience an exaggerated response to air pollutants. Ozone (O3) exposure has been associated with the activation of the neuroendocrine stress-response system. We hypothesized that preexistent mild chronic stress plus social isolation (CS), or social isolation (SI) alone, would exacerbate the acute effects of O3 exposure on the circulating adrenal-derived stress hormones, and the expression of the genes regulating glucocorticoid stress signaling via an altered stress adaptation in a brain-region-specific manner. Male Wistar-Kyoto rats (5 weeks old) were socially isolated, plus were subjected to either CS (noise, confinement, fear, uncomfortable living, hectic activity, and single housing), SI (single housing only, restricted handling and no enrichment) or no stress (NS; double housing, frequent handling and enrichment provided) for 8 weeks. The rats were then exposed to either air or O3 (0.8 ppm for 4 h), and the samples were collected immediately after. The indicators of sympathetic and hypothalamic-pituitary axis (HPA) activation (i.e., epinephrine, corticosterone, and lymphopenia) increased with O3 exposure, but there were no effects from CS or SI, except for the depletion of serum BDNF. CS and SI revealed small changes in brain-region-specific glucocorticoid-signaling-associated markers of gene expression in the air-exposed rats (hypothalamic Nr3c1, Nr3c2 Hsp90aa1, Hspa4 and Cnr1 inhibition in SI; hippocampal HSP90aa1 increase in SI; and inhibition of the bed nucleus of the stria terminalis (BNST) Cnr1 in CS). Gene expression across all brain regions was altered by O3, reflective of glucocorticoid signaling effects, such as Fkbp5 in NS, CS and SI. The SI effects on Fkbp5 were greatest for SI in BNST. O3 increased Cnr2 expression in the hypothalamus and olfactory bulbs of the NS and SI groups. O3, in all stress conditions, generally inhibited the expression of Nr3c1 in all brain regions, Nr3c2 in the hippocampus and hypothalamus and Bdnf in the hippocampus. SI, in general, showed slightly greater O3-induced changes when compared to NS and CS. Serum metabolomics revealed increased sphingomyelins in the air-exposed SI and O3-exposed NS, with underlying SI dampening some of the O3-induced changes. These results suggest a potential link between preexistent SI and acute O3-induced increases in the circulating adrenal-derived stress hormones and brain-region-specific gene expression changes in glucocorticoid signaling, which may partly underlie the stress dynamic in those with long-term SI.

Animal models and mechanisms of tobacco smoke-induced chronic obstructive pulmonary disease (COPD)

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide, and its global health burden is increasing. COPD is characterized by emphysema, mucus hypersecretion, and persistent lung inflammation, and clinically by chronic airflow obstruction and symptoms of dyspnea, cough, and fatigue in patients. A cluster of pathologies including chronic bronchitis, emphysema, asthma, and cardiovascular disease in the form of hypertension and atherosclerosis variably coexist in COPD patients. Underlying causes for COPD include primarily tobacco use but may also be driven by exposure to air pollutants, biomass burning, and workplace related fumes and chemicals. While no single animal model might mimic all features of human COPD, a wide variety of published models have collectively helped to improve our understanding of disease processes involved in the genesis and persistence of COPD. In this review, the pathogenesis and associated risk factors of COPD are examined in different mammalian models of the disease. Each animal model included in this review is exclusively created by tobacco smoke (TS) exposure. As animal models continue to aid in defining the pathobiological mechanisms of and possible novel therapeutic interventions for COPD, the advantages and disadvantages of each animal model are discussed.

Social isolation exacerbates acute ozone inhalation induced pulmonary and systemic health outcomes

Psychosocially-stressed individuals might have exacerbated responses to air pollution exposure. Acute ozone exposure activates the neuroendocrine stress response leading to systemic metabolic and lung inflammatory changes. We hypothesized chronic mild stress (CS) and/or social isolation (SI) would cause neuroendocrine, inflammatory, and metabolic phenotypes that would be exacerbated by an acute ozone exposure. Male 5-week-old Wistar-Kyoto rats were randomly assigned into 3 groups: no stress (NS) (pair-housed, regular-handling); SI (single-housed, minimal-handling); CS (single-housed, subjected to mild unpredicted-randomized stressors [restraint-1 h, tilted cage-1 h, shaking-1 h, intermittent noise-6 h, and predator odor-1 h], 1-stressor/day*5-days/week*8-weeks. All animals then 13-week-old were subsequently exposed to filtered-air or ozone (0.8-ppm) for 4 h and immediately necropsied. CS, but not SI animals had increased adrenal weights. However, relative to NS, both CS and SI had lower circulating luteinizing hormone, prolactin, and follicle-stimulating hormone regardless of exposure (SI > CS), and only CS demonstrated lower thyroid-stimulating hormone levels. SI caused more severe systemic inflammation than CS, as evidenced by higher circulating cytokines and cholesterol. Ozone exposure increased urine corticosterone and catecholamine metabolites with no significant stressor effect. Ozone-induced lung injury, and increases in lavage-fluid neutrophils and IL-6, were exacerbated by SI. Ozone severely lowered circulating thyroid-stimulating hormone, prolactin, and luteinizing hormone in all groups and exacerbated systemic inflammation in SI. Ozone-induced increases in serum glucose, leptin, and triglycerides were consistent across stressors; however, increases in cholesterol were exacerbated by SI. Collectively, psychosocial stressors, especially SI, affected the neuroendocrine system and induced adverse metabolic and inflammatory effects that were exacerbated by ozone exposure.

Stress Drivers of Glucose Dynamics during Ozone Exposure Measured Using Radiotelemetry in Rats

BACKGROUND

Inhaled irritant air pollutants may trigger stress-related metabolic dysfunction associated with altered circulating adrenal-derived hormones.

OBJECTIVES

We used implantable telemetry in rats to assess real-time changes in circulating glucose during and after exposure to ozone and mechanistically linked responses to neuroendocrine stress hormones.

METHODS

First, using a cross-over design, we monitored glucose during ozone exposures (0.0, 0.2, 0.4, and 0.8 ppm) and nonexposure periods in male Wistar Kyoto rats implanted with glucose telemeters. A second cohort of unimplanted rats was exposed to ozone (0.0, 0.4 or 0.8 ppm) for 30 min, 1 h, 2 h, or 4 h with hormones measured immediately post exposure. We assessed glucose metabolism in sham and adrenalectomized rats, with or without supplementation of adrenergic/glucocorticoid receptor agonists, and in a separate cohort, antagonists.

RESULTS

Ozone (0.8 ppm) was associated with significantly higher blood glucose and lower core body temperature beginning 90 min into exposure, with reversal of effects 4-6 h post exposure. Glucose monitoring during four daily 4-h ozone exposures revealed duration of glucose increases, adaptation, and diurnal variations. Ozone-induced glucose changes were preceded by higher levels of adrenocorticotropic hormone, corticosterone, and epinephrine but lower levels of thyroid-stimulating hormone, prolactin, and luteinizing hormones. Higher glucose and glucose intolerance were inhibited in rats that were adrenalectomized or treated with adrenergic plus glucocorticoid receptor antagonists but exacerbated by agonists.

DISCUSSION

We demonstrated the temporality of neuroendocrine-stress-mediated biological sequalae responsible for ozone-induced glucose metabolic dysfunction and mechanism in a rodent model. Stress hormones assessment with real-time glucose monitoring may be useful in identifying interactions among irritant pollutants and stress-related illnesses. https://doi.org/10.1289/EHP11088.

Nose-Only Exposure to Cherry- and Tobacco-Flavored E-Cigarettes Induced Lung Inflammation in Mice in a Sex-Dependent Manner

Flavoring chemicals in electronic nicotine delivery systems have been shown to cause cellular inflammation; meanwhile, the effects of fruit and tobacco flavors on lung inflammation by nose-only exposures to mice are relatively unknown. We hypothesized that exposure to flavored e-cigarettes would cause lung inflammation in C57BL/6 J mice. The mice were exposed to air, propylene glycol/vegetable glycerin, and flavored e-liquids: Apple, Cherry, Strawberry, Wintergreen, and Smooth & Mild Tobacco, one hour per day for three days. Quantification of flavoring chemicals by proton nuclear magnetic resonance spectroscopy (1H NMR), differential cell counts by flow cytometry, pro-inflammatory cytokines/chemokines by ELISA, and matrix metalloproteinase levels by western blot were performed. Exposure to PG/VG increased neutrophil cell count in lung bronchoalveolar lavage fluid (BALF). KC and IL6 levels were increased by PG/VG exposure and female mice exposed to Cherry flavored e-cigarettes, in lung homogenate. Mice exposed to PG/VG, Apple, Cherry, and Wintergreen increased MMP2 levels. Our results revealed flavor- and sex-based e-cigarette effects in female mice exposed to cherry-flavored e-liquids and male mice exposed to tobacco-flavored e-liquids, namely, increased lung inflammation.

Diets enriched with coconut, fish, or olive oil modify peripheral metabolic effects of ozone in rats

Dietary factors may modulate metabolic effects of air pollutant exposures. We hypothesized that diets enriched with coconut oil (CO), fish oil (FO), or olive oil (OO) would alter ozone-induced metabolic responses. Male Wistar-Kyoto rats (1-month-old) were fed normal diet (ND), or CO-, FO-, or OO-enriched diets. After eight weeks, animals were exposed to air or 0.8 ppm ozone, 4 h/day for 2 days. Relative to ND, CO- and OO-enriched diet increased body fat, serum triglycerides, cholesterols, and leptin, while all supplements increased liver lipid staining (OO > FO > CO). FO increased n-3, OO increased n-6/n-9, and all supplements increased saturated fatty-acids. Ozone increased total cholesterol, low-density lipoprotein, branched-chain amino acids (BCAA), induced hyperglycemia, glucose intolerance, and changed gene expression involved in energy metabolism in adipose and muscle tissue in rats fed ND. Ozone-induced glucose intolerance was exacerbated by OO-enriched diet. Ozone increased leptin in CO- and FO-enriched groups; however, BCAA increases were blunted by FO and OO. Ozone-induced inhibition of liver cholesterol biosynthesis genes in ND-fed rats was not evident in enriched dietary groups; however, genes involved in energy metabolism and glucose transport were increased in rats fed FO and OO-enriched diet. FO- and OO-enriched diets blunted ozone-induced inhibition of genes involved in adipose tissue glucose uptake and cholesterol synthesis, but exacerbated genes involved in adipose lipolysis. Ozone-induced decreases in muscle energy metabolism genes were similar in all dietary groups. In conclusion, CO-, FO-, and OO-enriched diets modified ozone-induced metabolic changes in a diet-specific manner, which could contribute to altered peripheral energy homeostasis.

Effect of environmental tobacco smoke on COX-2 and SHP-2 expression in a periodontitis rat model

OBJECTIVES

To investigate the effects of environmental tobacco smoke (ETS) on the inflammatory process of periodontitis by evaluating bone loss and the expression of cyclooxygenase-2 (COX-2) and Src homology phosphotyrosine phosphatase 2 (SHP-2).

MATERIALS AND METHODS

Eighty 6-month-old male SD rats were randomized into four groups (10 rats/group/per time point): (a) normal group, (b) ETS group, (c) ligature-induced periodontitis group, and (d) ligature-induced periodontitis + ETS group. After treatment with ligature and/or ETS for 8 and 12 weeks, the levels of alveolar bone resorption and the expressions of COX-2 and SHP-2 in periodontal tissue were analyzed using histology and immunohistochemistry.

RESULTS

The ligature-induced periodontitis group displayed increased bone resorption and elevated expression of COX-2 and SHP-2 in periodontal tissues compared to the normal and ETS groups at 8 and 12 weeks. Furthermore, bone resorption and COX-2 and SHP-2 levels in the ligature-induced periodontitis + ETS group were significantly increased compared to those in the normal and ligature-induced periodontitis groups at both 8 and 12 weeks.

CONCLUSION

Environmental tobacco smoke increased alveolar bone loss in periodontitis with enhanced expression of COX-2 and SHP-2 in periodontal tissues. Further investigation is needed to explore the role of COX-2 and SHP-2 in ETS-associated periodontitis.

Differential lung inflammation and injury with tobacco smoke exposure in Wistar Kyoto and spontaneously hypertensive rats

OBJECTIVE

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide and has been associated with periods of intense lung inflammation. The objective of this study was to characterize whether similar rat strains, possessing different genetic predispositions, might play a role in exacerbating the pathophysiology of COPD-like cellular and structural changes with progressive 12-week exposure to tobacco smoke (TS). Normotensive Wistar Kyoto (WKY) and spontaneously hypertensive (SH) rats were compared.

MATERIALS AND METHODS

WKY and SH rats were exposed to filtered air or to tobacco smoke at a particulate concentration of 80 mg/m3 for 4, 8, or 12 weeks. Necropsy was performed 24 h after the last exposure to obtain cells by bronchoalveolar lavage for total cell and differential counts. Scoring of lung tissues and immunohistochemical staining for M1 (pro-inflammatory) and M2 (anti-inflammatory) macrophages were performed on paraffin-embedded lung sections.

RESULTS AND DISCUSSION

With progressive exposure, TS-exposed SH rats demonstrated significant airspace enlargement, mucin production, and lung inflammation compared to their FA control and TS-matched WKY rats. Moreover, SH rats also demonstrated increased expression of the M1 marker in alveolar macrophages compared to FA control, as well as the M2 marker compared to controls and TS-exposed WKY rats.

CONCLUSION

The progressive tobacco smoke exposure contributes to persistent lung injury and inflammation that can be significantly enhanced by rat strain susceptibility in the genesis of COPD.

Long-Term Sequelae of Smoking and Cessation in Spontaneously Hypertensive Rats

Smoking is a major risk factor for heart attack, stroke, and lung cancer. Tobacco smoke (TS) causes bronchitis, emphysema, persistent cough, and dyspnea. Smoking cessation minimizes risks of TS-related disease. To determine whether smoking cessation could reverse TS-induced pulmonary changes, 10-week-old male spontaneously hypertensive rats were exposed to TS or filtered air (FA) for 39 weeks and allowed to live out their normal lifespan. Significantly (P ≤ .05) decreased survival was noted by 21 months in TS versus FA rats. In TS rats, persistent peribronchiolar, perivascular, alveolar, and subpleural inflammation were observed with pervasive infiltration of pigmented foamy macrophages and plausible intra-alveolar fibrosis and osseous metaplasia. Alveolar airspace was significantly (P ≤ .05) increased in TS versus FA rats as was the volume of stored epithelial mucosubstances in the left central axial airway. Increased mucin contributes to airflow obstruction and increased lung infection risks. Findings suggest TS-induced changes do not attenuate with smoking cessation but result in irreversible damage similar to chronic obstructive pulmonary disease. The observed persistent pulmonary changes mirror common TS effects such as chest congestion, sputum production, and shortness of breath long after smoking cessation and represent important targets for treatment of former smokers.

Susceptibility Variations in Air Pollution Health Effects: Incorporating Neuroendocrine Activation

Diverse host factors/phenotypes may exacerbate or diminish biological responses induced by air pollutant exposure. We lack an understanding of biological indicators of environmental exposures that culminate in a physiological response versus those that lead to adversity. Variations in response phenotype might arise centrally and/or at the local tissue level. In addition to genetic differences, the current evidence supports the roles of preexisting cardiopulmonary diseases, diabetes, diet, adverse prenatal environments, neurobehavioral disorders, childhood infections, microbiome, sex, and psychosocial stressors in modifying the susceptibility to air pollutant exposures. Animal models of human diseases, obesity, nutritional inadequacies, and neurobehavioral conditions have been compared with healthy controls to understand the causes of variations in susceptibility. Although psychosocial stressors have been associated with increased susceptibility to air pollutant effects, the contribution of neuroendocrine stress pathways in mediating these effects is just emerging. The new findings of neuroendocrine activation leading to systemic metabolic and immunological effects of air pollutants, and the potential contribution to allostatic load, emphasize the consideration of these mechanisms into susceptibility. Variations in susceptibility to air pollution health effects are likely to underlie host genetic and physiological conditions in concert with disrupted neuroendocrine circuitry that alters physiological stability under the influence of stressors.

Beta-2 Adrenergic and Glucocorticoid Receptor Agonists Modulate Ozone-Induced Pulmonary Protein Leakage and Inflammation in Healthy and Adrenalectomized Rats

We have shown that acute ozone inhalation activates sympathetic-adrenal-medullary and hypothalamus-pituitary-adrenal stress axes, and adrenalectomy (AD) inhibits ozone-induced lung injury and inflammation. Therefore, we hypothesized that stress hormone receptor agonists (β2 adrenergic-β2AR and glucocorticoid-GR) will restore the ozone injury phenotype in AD, while exacerbating effects in sham-surgery (SH) rats. Male Wistar Kyoto rats that underwent SH or AD were treated with vehicles (saline + corn oil) or β2AR agonist clenbuterol (CLEN, 0.2 mg/kg, i.p.) + GR agonist dexamethasone (DEX, 2 mg/kg, s.c.) for 1 day and immediately prior to each day of exposure to filtered air or ozone (0.8 ppm, 4 h/day for 1 or 2 days). Ozone-induced increases in PenH and peak-expiratory flow were exacerbated in CLEN+DEX-treated SH and AD rats. CLEN+DEX affected breath waveform in all rats. Ozone exposure in vehicle-treated SH rats increased bronchoalveolar lavage fluid (BALF) protein, N-acetyl glucosaminidase activity (macrophage activation), neutrophils, and lung cytokine expression while reducing circulating lymphocyte subpopulations. AD reduced these ozone effects in vehicle-treated rats. At the doses used herein, CLEN+DEX treatment reversed the protection offered by AD and exacerbated most ozone-induced lung effects while diminishing circulating lymphocytes. CLEN+DEX in air-exposed SH rats also induced marked protein leakage and reduced circulating lymphocytes but did not increase BALF neutrophils. In conclusion, circulating stress hormones and their receptors mediate ozone-induced vascular leakage and inflammatory cell trafficking to the lung. Those receiving β2AR and GR agonists for chronic pulmonary diseases, or with increased circulating stress hormones due to psychosocial stresses, might have altered sensitivity to air pollution.

The Intersection of Sex Differences, Tobacco Use, and Inflammation: Implications for Psychiatric Disorders

PURPOSE OF REVIEW

Tobacco use, sex differences, and psychiatric disorders are associated with altered immune function. There are also sex differences in tobacco use and psychiatric disorders. This review summarizes findings from the small, but growing literature examining sex differences in the effects of tobacco use on inflammation and the implications for psychiatric disorders.

RECENT FINDINGS

We identified four studies that tested the interaction between sex and tobacco/nicotine on inflammation. Although males and females generally exhibited differential tobacco-induced immune responses, the pattern varied depending on the sample (rodents vs. humans) and the method to evaluate inflammation. Evidence suggests that sex modulates the effects of tobacco smoke on inflammation. Many inflammation markers associated with sex differences and tobacco use are related to psychiatric disorders. We propose a model in which sex, tobacco use, and inflammation interact to increase risk for psychiatric disorders. Future studies are needed to examine the mechanisms that explain this relationship.

Ultrafine Particulate Matter Combined With Ozone Exacerbates Lung Injury in Mature Adult Rats With Cardiovascular Disease

Particulate matter (PM) and ozone (O3) are dominant air pollutants that contribute to development and exacerbation of multiple cardiopulmonary diseases. Mature adults with cardiovascular disease (CVD) are particularly susceptible to air pollution-related cardiopulmonary morbidities and mortalities. The aim was to investigate the biologic potency of ultrafine particulate matter (UFPM) combined with O3 in the lungs of mature adult normotensive and spontaneously hypertensive (SH) Wistar-Kyoto rats. Conscious, mature adult male normal Wistar-Kyoto (NW) and SH rats were exposed to one of the following atmospheres: filtered air (FA); UFPM (∼ 250 μg/m3); O3 (1.0 ppm); or UFPM + O3 (∼ 250 μg/m3 + 1.0 ppm) combined for 6 h, followed by an 8 h FA recovery period. Lung sections were evaluated for lesions in the large airways, terminal bronchiolar/alveolar duct regions, alveolar parenchyma, and vasculature. NW and SH rats were similarly affected by the combined-pollutant exposure, displaying severe injury in both large and small airways. SH rats were particularly susceptible to O3 exposure, exhibiting increased injury scores in terminal bronchioles and epithelial degeneration in large airways. UFPM-exposure groups had minimal histologic changes. The chemical composition of UFPM was altered by the addition of O3, indicating that ozonolysis promoted compound degradation. O3 increased the biologic potency of UFPM, resulting in greater lung injury following exposure. Pathologic manifestations of CVD may confer susceptibility to air pollution by impairing normal lung defenses and responses to exposure.

Adrenergic and glucocorticoid receptor antagonists reduce ozone-induced lung injury and inflammation

Recent studies showed that the circulating stress hormones, epinephrine and corticosterone/cortisol, are involved in mediating ozone-induced pulmonary effects through the activation of the sympathetic-adrenal-medullary (SAM) and hypothalamus-pituitary-adrenal (HPA) axes. Hence, we examined the role of adrenergic and glucocorticoid receptor inhibition in ozone-induced pulmonary injury and inflammation. Male 12-week old Wistar-Kyoto rats were pretreated daily for 7days with propranolol (PROP; a non-selective β adrenergic receptor [AR] antagonist, 10mg/kg, i.p.), mifepristone (MIFE; a glucocorticoid receptor [GR] antagonist, 30mg/kg, s.c.), both drugs (PROP+MIFE), or respective vehicles, and then exposed to air or ozone (0.8ppm), 4h/d for 1 or 2 consecutive days while continuing drug treatment. Ozone exposure alone led to increased peak expiratory flow rates and enhanced pause (Penh); with greater increases by day 2. Receptors blockade minimally affected ventilation in either air- or ozone-exposed rats. Ozone exposure alone was also associated with marked increases in pulmonary vascular leakage, macrophage activation, neutrophilic inflammation and lymphopenia. Notably, PROP, MIFE and PROP+MIFE pretreatments significantly reduced ozone-induced pulmonary vascular leakage; whereas PROP or PROP+MIFE reduced neutrophilic inflammation. PROP also reduced ozone-induced increases in bronchoalveolar lavage fluid (BALF) IL-6 and TNF-α proteins and/or lung Il6 and Tnfα mRNA. MIFE and PROP+MIFE pretreatments reduced ozone-induced increases in BALF N-acetyl glucosaminidase activity, and lymphopenia. We conclude that stress hormones released after ozone exposure modulate pulmonary injury and inflammatory effects through AR and GR in a receptor-specific manner. Individuals with pulmonary diseases receiving AR and GR-related therapy might experience changed sensitivity to air pollution.

In vitro exposure systems and dosimetry assessment tools for inhaled tobacco products: Workshop proceedings, conclusions and paths forward for in vitro model use

In 2009, the passing of the Family Smoking Prevention and Tobacco Control Act facilitated the establishment of the FDA Center for Tobacco Products (CTP), and gave it regulatory authority over the marketing, manufacture and distribution of tobacco products, including those termed 'modified risk'. On 4-6 April 2016, the Institute for In Vitro Sciences, Inc. (IIVS) convened a workshop conference entitled, In Vitro Exposure Systems and Dosimetry Assessment Tools for Inhaled Tobacco Products, to bring together stakeholders representing regulatory agencies, academia and industry to address the research priorities articulated by the FDA CTP. Specific topics were covered to assess the status of current in vitro smoke and aerosol/vapour exposure systems, as well as the various approaches and challenges to quantifying the complex exposures in in vitro pulmonary models developed for evaluating adverse pulmonary events resulting from tobacco product exposures. The four core topics covered were: a) Tobacco Smoke and E-Cigarette Aerosols; b) Air-Liquid Interface-In Vitro Exposure Systems; c) Dosimetry Approaches for Particles and Vapours/In Vitro Dosimetry Determinations; and d) Exposure Microenvironment/Physiology of Cells. The 2.5-day workshop included presentations from 20 expert speakers, poster sessions, networking discussions, and breakout sessions which identified key findings and provided recommendations to advance these technologies. Here, we will report on the proceedings, recommendations, and outcome of the April 2016 technical workshop, including paths forward for developing and validating non-animal test methods for tobacco product smoke and next generation tobacco product aerosol/vapour exposures. With the recent FDA publication of the final deeming rule for the governance of tobacco products, there is an unprecedented necessity to evaluate a very large number of tobacco-based products and ingredients. The questionable relevance, high cost, and ethical considerations for the use of in vivo testing methods highlight the necessity of robust in vitro approaches to elucidate tobacco-based exposures and how they may lead to pulmonary diseases that contribute to lung exposure-induced mortality worldwide.