Examining the association of habitual e-cigarette use with inflammation and endothelial dysfunction in young adults: The VAPORS-Endothelial function study.

INTRODUCTION: Acute exposure to e-cigarette aerosol has been shown to have potentially deleterious effects on the cardiovascular system. However, the cardiovascular effects of habitual e-cigarette use have not been fully elucidated. Therefore, we aimed to assess the association of habitual e-cigarette use with endothelial dysfunction and inflammation - subclinical markers known to be associated with increased cardiovascular risk. METHODS: In this cross-sectional study, we analyzed data from 46 participants (23 exclusive e-cigarette users; 23 non-users) enrolled in the VAPORS-Endothelial function study. E-cigarette users had used e-cigarettes for ≥6 consecutive months. Non-users had used e-cigarettes <5 times and had a negative urine cotinine test (<30 ng/mL). Flow-mediated dilation (FMD) and reactive hyperemia index (RHI) were used to assess endothelial dysfunction, and we assayed high-sensitivity C-reactive protein, interleukin-6, fibrinogen, p-selectin, and myeloperoxidase as serum measures of inflammation. We used multivariable linear regression to assess the association of e-cigarette use with the markers of endothelial dysfunction and inflammation. RESULTS: Of the 46 participants with mean age of 24.3 ± 4.0 years, the majority were males (78%), non-Hispanic (89%), and White (59%). Among non-users, 6 had cotinine levels <10 ng/mL while 17 had levels 10-30 ng/mL. Conversely, among e-cigarette users, the majority (14 of 23) had cotinine ≥500 ng/mL. At baseline, the systolic blood pressure was higher among e-cigarette users than non-users (p=0.011). The mean FMD was slightly lower among e-cigarette users (6.32%) compared to non-users (6.53%). However, in the adjusted analysis, current e-cigarette users did not differ significantly from non-users in their mean FMD (Coefficient=2.05; 95% CI: -2.52-6.63) or RHI (Coefficient= -0.20; 95% CI: -0.88-0.49). Similarly, the levels of inflammatory markers were generally low and did not differ between e-cigarette users and non-users. CONCLUSIONS: Our findings suggest that e-cigarette use may not be significantly associated with endothelial dysfunction and systemic inflammation in relatively young and healthy individuals. Longer term studies with larger sample sizes are needed to validate these findings.

Ambient particulate matter air pollution is associated with increased risk of papillary thyroid cancer.

BACKGROUND: The association between exposure to air pollution and papillary thyroid carcinoma is unknown. We sought to estimate the relationship between long-term exposure to the fine (diameter ≤ 2.5 µm) particulate matter component of air pollution and the risk of papillary thyroid cancer. METHODS: Adult (age ≥18) patients with newly diagnosed papillary thyroid carcinoma between January 1, 2013 and December 31, 2016 across a single health system were identified using electronic medical records. Data from 1,990 patients with papillary thyroid carcinoma were compared with 3,980 age- and sex-matched control subjects without any evidence of thyroid disease. Cumulative fine (diameter <2.5 µm) particulate matter exposure was estimated by incorporating patients' residential zip codes into a deep learning neural networks model, which uses both meteorological and satellite-based measurements. Conditional logistic regression was performed to assess for association between papillary thyroid carcinoma and increasing fine (diameter ≤2.5 µm) particulate matter concentrations over 1, 2, and 3 years of cumulative exposure preceding papillary thyroid carcinoma diagnosis. RESULTS: Increased odds of developing papillary thyroid carcinoma was associated with a 5 µg/m3 increase of fine (diameter ≤2.5 µm) particulate matter concentrations over 2 years (adjusted odds ratio = 1.18, 95% confidence interval: 1.00-1.40) and 3 years (adjusted odds ratio = 1.23, 95% confidence interval: 1.05-1.44) of exposure. This risk differed by smoking status (pinteraction = 0.04). Among current smokers (n = 623), the risk of developing papillary thyroid carcinoma was highest (adjusted odds ratio = 1.35, 95% confidence interval: 1.12-1.63). CONCLUSION: Increasing concentration of fine (diameter ≤2.5 µm) particulate matter in air pollution is significantly associated with the incidence of papillary thyroid carcinoma with 2 and 3 years of exposure. Our novel findings provide additional insight into the potential associations between risk factors and papillary thyroid carcinoma and warrant further investigation, specifically in areas with high levels of air pollution both nationally and internationally.

Prenatal Environmental Metal Exposure and Preterm Birth: A Scoping Review.

Preterm birth (PTB) and its complications are the leading causes of under-five year old child deaths, accounting worldwide for an estimated one million deaths annually. The etiology of PTB is complex and multifactorial. Exposures to environmental metals or metalloids are pervasive and prenatal exposures to them are considered important in the etiology of PTB. We conducted a scoping review to determine the extent of prenatal exposures to four metals/metalloids (lead, mercury, cadmium and arsenic) and their association with PTB. We reviewed original research studies published in PubMed, Embase, the Cochrane Library, Scopus, POPLINE and the WHO regional indexes from 2000 to 2019; 36 articles were retained for full text review. We documented a higher incidence of PTB with lead and cadmium exposures. The findings for mercury and arsenic exposures were inconclusive. Metal-induced oxidative stress in the placenta, epigenetic modification, inflammation, and endocrine disruptions are the most common pathways through which heavy metals and metalloids affect placental functions leading to PTB. Most of the studies were from the high-income countries, reflecting the need for additional data from low-middle-income countries, where PTB rates are higher and prenatal exposure to metals are likely to be just as high, if not higher.

Design and development of innovative microparticulate/nanoparticulate inhalable dry powders of a novel synthetic trifluorinated chalcone derivative and Nrf2 agonist.

Chalcone derivatives are shown to possess excellent anti-inflammatory and anti-oxidant properties which are of great interest in treating respiratory diseases such as acute lung injury (ALI), acute respiratory distress syndrome (ARDS), chronic obstructive pulmonary disease (COPD), and pulmonary fibrosis (PF). This study successfully designed and developed dry powder inhaler (DPI) formulations of TMC (2-trifluoromethyl-2'-methoxychalone), a new synthetic trifluorinated chalcone and Nrf2 agonist, for targeted pulmonary inhalation aerosol drug delivery. An advanced co-spray drying particle engineering technique was used to design and produce microparticulate/nanoparticulate formulations of TMC with a suitable excipient (mannitol) as inhalable particles with tailored particle properties for inhalation. Raw TMC and co-spray dried TMC formulations were comprehensively characterized for the first time using scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) spectroscopy, thermal analysis, X-ray powder diffraction (XRPD), and molecular fingerprinting as dry powders by ATR-FTIR spectroscopy and Raman spectroscopy. Further, biocompatibility and suitability of formulations were tested with in vitro cellular transepithelial electrical resistance (TEER) in air-interface culture (AIC) using a human pulmonary airway cell line. The ability of these TMC formulations to perform as aerosolized dry powders was systematically evaluated by design of experiments (DOEs) using three different FDA-approved human inhaler devices followed by interaction parameter analyses. Multiple spray drying pump rates (25%, 75%, and 100%) successfully produced co-spray dried TMC:mannitol powders. Raw TMC exhibited a first-order phase transition temperature at 58.15 ± 0.38 °C. Furthermore, the results demonstrate that these innovative TMC dry powder particles are suitable for targeted delivery to the airways by inhalation.

Association Between E-Cigarette Use and Chronic Obstructive Pulmonary Disease by Smoking Status: Behavioral Risk Factor Surveillance System 2016 and 2017.

INTRODUCTION: The association between e-cigarette use and chronic bronchitis, emphysema, and chronic obstructive pulmonary disease has not been studied thoroughly, particularly in populations defined by concomitant combustible smoking status. METHODS: Using pooled 2016 and 2017 data from the Behavioral Risk Factor Surveillance System, investigators studied 705,159 participants with complete self-reported information on e-cigarette use, combustible cigarette use, key covariates, and chronic bronchitis, emphysema, or chronic obstructive pulmonary disease. Current e-cigarette use was the main exposure, with current use further classified as daily or occasional use. The main outcome was defined as reported ever having a diagnosis of chronic bronchitis, emphysema, or chronic obstructive pulmonary disease. For all the analyses, multivariable adjusted logistic regression was used, with the study population stratified by combustible cigarette use status (never, former, or current). All the analyses were conducted in 2019. RESULTS: Of 705,159 participants, 25,175 (3.6%) were current e-cigarette users, 64,792 (9.2%) current combustible cigarette smokers, 207,905 (29.5%) former combustible cigarette smokers, 432,462 (61.3%) never combustible cigarette smokers, and 14,036 (2.0%) dual users of e-cigarettes and combustible cigarettes. A total of 53,702 (7.6%) participants self-reported chronic bronchitis, emphysema, or chronic obstructive pulmonary disease. Among never combustible cigarette smokers, current e-cigarette use was associated with 75% higher odds of chronic bronchitis, emphysema, or chronic obstructive pulmonary disease compared with never e-cigarette users (OR=1.75, 95% CI=1.25, 2.45), with daily users of e-cigarettes having the highest odds (OR=2.64, 95% CI=1.43, 4.89). Similar associations between e-cigarette use and chronic bronchitis, emphysema, or chronic obstructive pulmonary disease were noted among both former and current combustible cigarette smokers. CONCLUSIONS: The results suggest possible e-cigarette-related pulmonary toxicity across all the categories of combustible cigarette smoking status, including those who had never smoked combustible cigarettes.

Systemic Activation of NRF2 Alleviates Lethal Autoimmune Inflammation in Scurfy Mice.

The transcription factor NRF2 (nuclear factor [erythroid-derived 2]-like 2) plays crucial roles in the defense mechanisms against oxidative stress and mediates anti-inflammatory actions under various pathological conditions. Recent studies showed that the dysfunction of regulatory T cells (Tregs) is directly linked to the initiation and progression of various autoimmune diseases. To determine the Treg-independent impact of NRF2 activation on autoimmune inflammation, we examined scurfy (Sf) mice, which are deficient in Tregs and succumb to severe multiorgan inflammation by 4 weeks of age. We found that systemic activation of NRF2 by Keap1 (Kelch-like ECH-associated protein 1) knockdown ameliorated tissue inflammation and lethality in Sf mice. Activated T cells and their cytokine production were accordingly decreased by Keap1 knockdown. In contrast, NRF2 activation through cell lineage-specific Keap1 disruption (i.e., in T cells, myeloid cells, and dendritic cells) achieved only partial or no improvement in the inflammatory status of Sf mice. Our results indicate that systemic activation of NRF2 suppresses effector T cell activities independently of Tregs and that NRF2 activation in multiple cell lineages appears to be required for sufficient anti-inflammatory effects. This study emphasizes the possible therapeutic application of NRF2 inducers in autoimmune diseases that are accompanied by Treg dysfunction.

Nrf2 exerts cell-autonomous antifibrotic effects: compromised function in systemic sclerosis and therapeutic rescue with a novel heterocyclic chalcone derivative.

The transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) governs antioxidant, innate immune and cytoprotective responses and its deregulation is prominent in chronic inflammatory conditions. To examine the hypothesis that Nrf2 might be implicated in systemic sclerosis (SSc), we investigated its expression, activity, and mechanism of action in SSc patient samples and mouse models of fibrosis and evaluated the effects of a novel pharmacologic Nrf2 agonist. We found that both expression and activity of Nrf2 were significantly reduced in SSc patient skin biopsies and showed negative correlation with inflammatory gene expression. In skin fibroblasts, Nrf2 mitigated fibrotic responses by blocking canonical transforming growth factor-ß (TGF-ß)-Smad signaling, whereas silencing Nrf2 resulted in constitutively elevated collagen synthesis, spontaneous myofibroblast differentiation, and enhanced TGF-ß responses. Bleomycin treatment of Nrf2-null mice resulted in exaggerated fibrosis. In wild-type mice, treatment with a novel pharmacologic Nrf2 agonist 2-trifluoromethyl-2'-methoxychalcone prevented dermal fibrosis induced by TGF-ß. These findings are the first to identify Nrf2 as a cell-intrinsic antifibrotic factor with key roles in maintaining extracellular matrix homeostasis and a pathogenic role in SSc. Pharmacologic reactivation of Nrf2, therefore, represents a novel therapeutic strategy toward effective treatment of fibrosis in SSc.

Nrf2-Mediated Regulation of Skeletal Muscle Glycogen Metabolism.

Nrf2 (NF-E2-related factor 2) contributes to the maintenance of glucose homeostasis in vivo Nrf2 suppresses blood glucose levels by protecting pancreatic ß cells from oxidative stress and improving peripheral tissue glucose utilization. To elucidate the molecular mechanisms by which Nrf2 contributes to the maintenance of glucose homeostasis, we generated skeletal muscle (SkM)-specific Keap1 knockout (Keap1MuKO) mice that express abundant Nrf2 in their SkM and then examined Nrf2 target gene expression in that tissue. In Keap1MuKO mice, blood glucose levels were significantly downregulated and the levels of the glycogen branching enzyme (Gbe1) and muscle-type PhKα subunit (Phka1) mRNAs, along with those of the glycogen branching enzyme (GBE) and the phosphorylase b kinase α subunit (PhKα) protein, were significantly upregulated in mouse SkM. Consistent with this result, chemical Nrf2 inducers promoted Gbe1 and Phka1 mRNA expression in both mouse SkM and C2C12 myotubes. Chromatin immunoprecipitation analysis demonstrated that Nrf2 binds the Gbe1 and Phka1 upstream promoter regions. In Keap1MuKO mice, muscle glycogen content was strongly reduced and forced GBE expression in C2C12 myotubes promoted glucose uptake. Therefore, our results demonstrate that Nrf2 induction in SkM increases GBE and PhKα expression and reduces muscle glycogen content, resulting in improved glucose tolerance. Our results also indicate that Nrf2 differentially regulates glycogen metabolism in SkM and the liver.

Marburgvirus hijacks nrf2-dependent pathway by targeting nrf2-negative regulator keap1.

Marburg virus (MARV) has a high fatality rate in humans, causing hemorrhagic fever characterized by massive viral replication and dysregulated inflammation. Here, we demonstrate that VP24 of MARV binds Kelch-like ECH-associated protein 1 (Keap1), a negative regulator of nuclear transcription factor erythroid-derived 2 (Nrf2). Binding of VP24 to Keap1 Kelch domain releases Nrf2 from Keap1-mediated inhibition promoting persistent activation of a panoply of cytoprotective genes implicated in cellular responses to oxidative stress and regulation of inflammatory responses. Increased expression of Nrf2-dependent genes was demonstrated both during MARV infection and upon ectopic expression of MARV VP24. We also show that Nrf2-deficient mice can control MARV infection when compared to lethal infection in wild-type animals, indicating that Nrf2 is critical for MARV infection. We conclude that VP24-driven activation of the Nrf2-dependent pathway is likely to contribute to dysregulation of host antiviral inflammatory responses and that it ensures survival of MARV-infected cells despite these responses.

Histone deacetylase 6-mediated selective autophagy regulates COPD-associated cilia dysfunction.

Chronic obstructive pulmonary disease (COPD) involves aberrant airway inflammatory responses to cigarette smoke (CS) that are associated with epithelial cell dysfunction, cilia shortening, and mucociliary clearance disruption. Exposure to CS reduced cilia length and induced autophagy in vivo and in differentiated mouse tracheal epithelial cells (MTECs). Autophagy-impaired (Becn1+/- or Map1lc3B-/-) mice and MTECs resisted CS-induced cilia shortening. Furthermore, CS increased the autophagic turnover of ciliary proteins, indicating that autophagy may regulate cilia homeostasis. We identified cytosolic deacetylase HDAC6 as a critical regulator of autophagy-mediated cilia shortening during CS exposure. Mice bearing an X chromosome deletion of Hdac6 (Hdac6-/Y) and MTECs from these mice had reduced autophagy and were protected from CS-induced cilia shortening. Autophagy-impaired Becn1-/-, Map1lc3B-/-, and Hdac6-/Y mice or mice injected with an HDAC6 inhibitor were protected from CS-induced mucociliary clearance (MCC) disruption. MCC was preserved in mice given the chemical chaperone 4-phenylbutyric acid, but was disrupted in mice lacking the transcription factor NRF2, suggesting that oxidative stress and altered proteostasis contribute to the disruption of MCC. Analysis of human COPD specimens revealed epigenetic deregulation of HDAC6 by hypomethylation and increased protein expression in the airways. We conclude that an autophagy-dependent pathway regulates cilia length during CS exposure and has potential as a therapeutic target for COPD.

Identification of genes promoting angiogenesis in mouse lung by transcriptional profiling.

A better understanding of the regulation of factors that promote angiogenesis may ultimately enable improved therapeutic control of this important process. In our previous studies, obstruction of the left pulmonary artery in the mouse consistently induced the formation of a new vasculature, which developed from the visceral pleura and entered the upper left lung directly within 5-6 days after ligation. No new vessels developed to the lower left lung, despite the initial ischemic stimulus being identical to that in the upper lung. Using this unique model of angiogenesis, we have determined the temporal pattern of differential gene expression from two independent regions of the same lung: one where angiogenesis is induced, and the other where angiogenesis does not occur. Microarray analysis and quantitative real-time RT-PCR were used to compare the signals from these two lung regions in the first 3 d following ischemia. The findings reveal the important roles of ELR+ CXC chemokines as proangiogenic signals. Genes involved in tissue remodeling, inflammation, and injury were also upregulated in the proangiogenic upper lung. Results also confirm that lung ischemia, rather than hypoxia, is the essential trigger for angiogenesis. These altered profiles of expression in the early stage of lung ischemia show potential roles and interactions of the most important genes involved in promoting new blood vessel formation.