Benefits of Aeroallergen Testing on Oral Corticosteroid Bursts in Adults with Asthma.

BACKGROUND: Aeroallergen testing can improve precision care for persistent asthma and is recommended by the U.S. clinical guidelines. How testing benefits diverse populations of adults with asthma, and the importance of the testing modality used, are not fully understood. OBJECTIVE: We sought to evaluate whether receipt of aeroallergen testing was associated with a reduction in oral corticosteroid (OCS) bursts. METHODS: We used electronic health record data to conduct a retrospective, observational cohort study of adults with asthma who were prescribed an inhaled corticosteroid and had an Allergy/Immunology visit in a large health system between 1/1/2017-6/30/2022. Negative binomial regression models were used to evaluate whether OCS bursts in the 12-month period after an initial visit were reduced for patients who received aeroallergen testing. We also measured differences in benefit after excluding patients with chronic obstructive pulmonary disease (COPD) and smoking histories, and whether testing receipt was via skin prick or serum. RESULTS: 668/1,383 (48.3%) patients received testing. Receipt of testing was not associated with fewer bursts in all patients (incidence rate ratio (IRR)=0.83 versus no testing, p=0.059), but it was among never smokers without COPD (417/844 tested, IRR=0.68, p=0.004). The receipt of skin testing was associated with fewer bursts in all patients (418/1,383 tested, IRR=0.77, p=0.02) and among never smokers without COPD (283/844 tested, IRR=0.59 versus no testing, p=0.001). CONCLUSION: Guideline-concordant aeroallergen testing in the context of Allergy/Immunology care was associated with clinical benefit in a real-life, diverse cohort of adults with asthma. This benefit varied according to patient comorbidities and the testing modality.

Analytical challenges in omics research on asthma and allergy: A National Institute of Allergy and Infectious Diseases workshop.

Studies of asthma and allergy are generating increasing volumes of omics data for analysis and interpretation. The National Institute of Allergy and Infectious Diseases (NIAID) assembled a workshop comprising investigators studying asthma and allergic diseases using omics approaches, omics investigators from outside the field, and NIAID medical and scientific officers to discuss the following areas in asthma and allergy research: genomics, epigenomics, transcriptomics, microbiomics, metabolomics, proteomics, lipidomics, integrative omics, systems biology, and causal inference. Current states of the art, present challenges, novel and emerging strategies, and priorities for progress were presented and discussed for each area. This workshop report summarizes the major points and conclusions from this NIAID workshop. As a group, the investigators underscored the imperatives for rigorous analytic frameworks, integration of different omics data types, cross-disciplinary interaction, strategies for overcoming current limitations, and the overarching goal to improve scientific understanding and care of asthma and allergic diseases.

Identification of novel NRF2-dependent genes as regulators of lead and arsenic toxicity in neural progenitor cells.

Lead (Pb) and arsenic (As) are prevalent metal contaminants in the environment. Exposures to these metals are associated with impaired neuronal functions and adverse effects on neurodevelopment in children. However, the molecular mechanisms by which Pb and As impair neuronal functions remain poorly understood. Here, we identified F2RL2, TRIM16L, and PANX2 as novel targets of Nuclear factor erythroid 2-related factor 2 (NRF2)-the master transcriptional factor for the oxidative stress response-that are commonly upregulated with both Pb and As in human neural progenitor cells (NPCs). Using a ChIP (Chromatin immunoprecipitation)-qPCR assay, we showed that NRF2 directly binds to the promoter region of F2RL2, TRIM16L, and PANX2 to regulate expression of these genes. We demonstrated that F2RL2, PANX2, and TRIM16L have differential effects on cell death, proliferation, and differentiation of NPCs in both the presence and absence of metal exposures, highlighting their roles in regulating NPC function. Furthermore, the analyses of the transcriptomic data on NPCs derived from autism spectrum disorder (ASD) patients revealed that dysregulation of F2RL2, TRIM16L, and PANX2 was associated with ASD genetic backgrounds and ASD risk genes. Our findings revealed that Pb and As induce a shared NRF2-dependent transcriptional response in NPCs and identified novel genes regulating NPC function. While further in vivo studies are warranted, this study provides a novel mechanism linking metal exposures to NPC function and identifies potential genes of interest in the context of neurodevelopment.

A missense variant in human perilipin 2 (PLIN2 Ser251Pro) reduces hepatic steatosis in mice.

Background & Aims: Non-alcoholic fatty liver disease (NAFLD) is characterised by the accumulation of lipid droplets (LDs) within hepatocytes. Perilipin 2 (PLIN2) is the most abundant protein in hepatic LDs and its expression correlates with intracellular lipid accumulation. A recently discovered PLIN2 coding variant, Ser251Pro (rs35568725), was found to promote the accumulation of small LDs in embryonic kidney cells. In this study, we investigate the role of PLIN2-Ser251Pro (PLIN2-Pro251) on hepatic LD metabolism in vivo and research the metabolic phenotypes associated with this variant in humans. Methods: For our animal model, we used Plin2 knockout mice in which we expressed either human PLIN2-Pro251 (Pro251 mice) or wild-type human PLIN2-Ser251 (Ser251 mice) in a hepatocyte-specific manner. We fed both cohorts a lipogenic high-fat, high-cholesterol, high-fructose diet for 12 weeks. Results: Pro251 mice were associated with reduced liver triglycerides (TGs) and had lower mRNA expression of fatty acid synthase and diacylglycerol O-acyltransferase-2 compared with Ser251 mice. Moreover, Pro251 mice had a reduction of polyunsaturated fatty acids-TGs and reduced expression of epoxygenase genes. For our human study, we analysed the Penn Medicine BioBank, the Million Veteran Program, and UK Biobank. Across these databases, the minor allele frequency of PLIN2-Pro251 was approximately 5%. There was no association with the clinical diagnosis of NAFLD, however, there was a trend toward reduced liver fat in PLIN2-Pro251 carriers by MRI-spectroscopy in UK Biobank subjects. Conclusions: In mice lacking endogenous Plin2, expression of human PLIN2-Pro251 attenuated high-fat, high-fructose, high-cholesterol, diet-induced hepatic steatosis compared with human wild-type PLIN2-Ser251. Moreover, Pro251 mice had lower polyunsaturated fatty acids-TGs and epoxygenase genes expression, suggesting less liver oxidative stress. In humans, PLIN2-Pro251 is not associated with NAFLD. Impact and Implications: Lipid droplet accumulation in hepatocytes is the distinctive characteristic of non-alcoholic fatty liver disease. Perilipin 2 (PLIN2) is the most abundant protein in hepatic lipid droplets; however, little is known on the role of a specific polymorphism PLIN2-Pro251 on hepatic lipid droplet metabolism. PLIN2-Pro251 attenuates liver triglycerides accumulation after a high-fat-high-glucose-diet. PLIN2-Pro251 may be a novel lipid droplet protein target for the treatment of liver steatosis.

Factors associated with aeroallergen testing among adults with asthma in a large health system.

Background: Aeroallergen testing informs precision care for adults with asthma, yet the epidemiology of testing in this population remains poorly understood. Objective: We sought to identify factors associated with receiving aeroallergen testing, the results of these tests, and subsequent reductions in exacerbation measures among adults with asthma. Methods: We used electronic health record data to conduct a retrospective, observational cohort study of 30,775 adults with asthma who had an office visit with a primary care provider or an asthma specialist from January 1, 2017, to August 26, 2022. We used regression models to identify (1) factors associated with receiving any aeroallergen test and tests to 9 allergen categories after the index visit, (2) factors associated with positive test results, and (3) reductions in asthma exacerbation measures in the year after testing compared with before testing. Results: Testing was received by 2201 patients (7.2%). According to multivariable models, receiving testing was associated with having any office visit with an allergy/immunology specialist during the study period (odds ratio [OR] = 91.3 vs primary care only [P < .001]) and having an asthma emergency department visit (OR = 1.62 [P = .004]) or hospitalization (OR = 1.62 [P = .03]) in the year before the index visit. Age 65 years or older conferred decreased odds of testing (OR = 0.74 vs age 18-34 years [P = .008]) and negative test results to 6 categories (P ≤ .04 for all comparisons). Black race conferred increased odds of testing (OR =1.22 vs White race [P = .01]) and positive test results to 8 categories (P < .04 for all comparisons). Exacerbation measures decreased after testing. Conclusion: Aeroallergen testing was performed infrequently among adults with asthma and was associated with reductions in asthma exacerbation measures.

Genetic Variation and Sensory Perception of a Pediatric Formulation of Ibuprofen: Can a Medicine Taste Too Good for Some?

There is wide variation in how individuals perceive the chemosensory attributes of liquid formulations of ibuprofen, encompassing both adults and children. To understand personal variation in the taste and chemesthesis properties of this medicine, and how to measure it, our first scientific strategy centered on utilizing trained adult panelists, due to the complex and time-consuming psychophysical tasks needed at this initial stage. We conducted a double-blind cohort study in which panelists underwent whole-genome-wide genotyping and psychophysically evaluated an over-the-counter pediatric medicine containing ibuprofen. Associations between sensory phenotypes and genetic variation near/within irritant and taste receptor genes were determined. Panelists who experienced the urge to cough or throat sensations found the medicine less palatable and sweet, and more irritating. Perceptions varied with genetic ancestry; panelists of African genetic ancestry had fewer chemesthetic sensations, rating the medicine sweeter, less irritating, and more palatable than did those of European genetic ancestry. We discovered a novel association between TRPA1 rs11988795 and tingling sensations, independent of ancestry. We also determined for the first time that just tasting the medicine allowed predictions of perceptions after swallowing, simplifying future psychophysical studies on diverse populations of different age groups needed to understand genetic, cultural-dietary, and epigenetic factors that influence individual perceptions of palatability and, in turn, adherence and the risk of accidental ingestion.

Building Career Paths for Ph.D., Basic and Translational Scientists in Clinical Departments in the United States: An Official American Thoracic Society Workshop Report.

Rationale: To identify barriers and opportunities for Ph.D., basic and translational scientists to be fully integrated into clinical units. Objectives: In 2022, an ad hoc committee of the American Thoracic Society developed a project proposal and workshop to identify opportunities and barriers for scientists who do not practice medicine to develop successful careers and achieve tenure-track faculty positions in clinical departments and divisions within academic medical centers (AMCs) in the United States. Methods: This document focuses on results from a survey of adult and pediatric pulmonary, critical care, and sleep medicine division chiefs as well as a survey of workshop participants, including faculty in departmental and school leadership roles in both basic science and clinical units within U.S. AMCs. Results: We conclude that full integration of non-clinically practicing basic and translational scientists into the clinical units, in addition to their traditional placements in basic science units, best serves the tripartite mission of AMCs to provide care, perform research, and educate the next generation. Evidence suggests clinical units do employ Ph.D. scientists in large numbers, but these faculty are often hired into non-tenure track positions, which do not provide the salary support, start-up funds, research independence, or space often associated with hiring in basic science units within the same institution. These barriers to success of Ph.D. faculty in clinical units are largely financial. Conclusions: Our recommendation is for AMCs to consider and explore some of our proposed strategies to accomplish the goal of integrating basic and translational scientists into clinical units in a meaningful way.

Improving Genetic Association Studies with a Novel Methodology that Unveils the Hidden Complexity of All-Cause Heart Failure.

Motivation: Genome-Wide Association Studies (GWAS) commonly assume phenotypic and genetic homogeneity that is not present in complex conditions. We designed Transformative Regression Analysis of Combined Effects (TRACE), a GWAS methodology that better accounts for clinical phenotype heterogeneity and identifies gene-by-environment (GxE) interactions. We demonstrated with UK Biobank (UKB) data that TRACE increased the variance explained in All-Cause Heart Failure (AHF) via the discovery of novel single nucleotide polymorphism (SNP) and SNP-by-environment (i.e. GxE) interaction associations. First, we transformed 312 AHF-related ICD10 codes (including AHF) into continuous low-dimensional features (i.e., latent phenotypes) for a more nuanced disease representation. Then, we ran a standard GWAS on our latent phenotypes to discover main effects and identified GxE interactions with target encoding. Genes near associated SNPs subsequently underwent enrichment analysis to explore potential functional mechanisms underlying associations. Latent phenotypes were regressed against their SNP hits and the estimated latent phenotype values were used to measure the amount of AHF variance explained. Results: Our method identified over 100 main GWAS effects that were consistent with prior studies and hundreds of novel gene-by-smoking interactions, which collectively accounted for approximately 10% of AHF variance. This represents an improvement over traditional GWAS whose results account for a negligible proportion of AHF variance. Enrichment analyses suggested that hundreds of miRNAs mediated the SNP effect on various AHF-related biological pathways. The TRACE framework can be applied to decode the genetics of other complex diseases. Availability: All code is available at https://github.com/EpistasisLab/latent_phenotype_project.

Linking Ambient NO2 Pollution Measures with Electronic Health Record Data to Study Asthma Exacerbations.

Electronic health record (EHR)-derived data can be linked to geospatially distributed socioeconomic and environmental factors to conduct large-scale epidemiologic studies. Ambient NO2 is a known environmental risk factor for asthma. However, health exposure studies often rely on data from geographically sparse regulatory monitors that may not reflect true individual exposure. We contrasted use of interpolated NO2 regulatory monitor data with raw satellite measurements and satellite-derived ground estimates, building on previous work which has computed improved exposure estimates from remotely sensed data. Raw satellite and satellite-derived ground measurements captured spatial variation missed by interpolated ground monitor measurements. Multivariable analyses comparing these three NO2 measurement approaches (interpolated monitor, raw satellite, and satellite-derived) revealed a positive relationship between exposure and asthma exacerbations for both satellite measurements. Exposure-outcome relationships using the interpolated monitor NO2 were inconsistent with known relationships to asthma, suggesting that interpolated monitor data might yield misleading results in small region studies.

Factors Associated With Asthma Biologic Prescribing and Primary Adherence Among Adults in a Large Health System.

BACKGROUND: The availability of asthma biologics may not benefit all patients equally. OBJECTIVE: We sought to identify patient characteristics associated with asthma biologic prescribing, primary adherence, and effectiveness. METHODS: A retrospective, observational cohort study of 9,147 adults with asthma who established care with a Penn Medicine asthma subspecialist was conducted using Electronic Health Record data from January 1, 2016, to October 18, 2021. Multivariable regression models were used to identify factors associated with (1) receipt of a new biologic prescription; (2) primary adherence, defined as receiving a dose in the year after receiving the prescription, and (3) oral corticosteroid (OCS) bursts in the year after the prescription. RESULTS: Factors associated with a new prescription, which was received by 335 patients, included being a woman (odds ratio [OR] 0.66; P = .002), smoking currently (OR 0.50; P = .04), having an asthma hospitalization in the prior year (OR 2.91; P < .001), and having 4+ OCS bursts in the prior year (OR 3.01; P < .001). Reduced primary adherence was associated with Black race (incidence rate ratio 0.85; P < .001) and Medicaid insurance (incidence rate ratio 0.86; P < .001), although most in these groups, 77.6% and 74.3%, respectively, still received a dose. Nonadherence was associated with patient-level barriers in 72.2% of cases and health insurance denial in 22.2%. Having more OCS bursts after receiving a biologic prescription was associated with Medicaid insurance (OR 2.69; P = .047) and biologic days covered (OR 0.32 for 300-364 d vs 14-56 d; P = .03). CONCLUSIONS: In a large health system, primary adherence to asthma biologics varied by race and insurance type, whereas nonadherence was primarily explained by patient-level barriers.

Antagonizing cholecystokinin A receptor in the lung attenuates obesity-induced airway hyperresponsiveness.

Obesity increases asthma prevalence and severity. However, the underlying mechanisms are poorly understood, and consequently, therapeutic options for asthma patients with obesity remain limited. Here we report that cholecystokinin-a metabolic hormone best known for its role in signaling satiation and fat metabolism-is increased in the lungs of obese mice and that pharmacological blockade of cholecystokinin A receptor signaling reduces obesity-associated airway hyperresponsiveness. Activation of cholecystokinin A receptor by the hormone induces contraction of airway smooth muscle cells. In vivo, cholecystokinin level is elevated in the lungs of both genetically and diet-induced obese mice. Importantly, intranasal administration of cholecystokinin A receptor antagonists (proglumide and devazepide) suppresses the airway hyperresponsiveness in the obese mice. Together, our results reveal an unexpected role for cholecystokinin in the lung and support the repurposing of cholecystokinin A receptor antagonists as a potential therapy for asthma patients with obesity.

CEBPD modulates the airway smooth muscle transcriptomic response to glucocorticoids.

BACKGROUND: CCAAT/Enhancer Binding Protein D (CEBPD), a pleiotropic glucocorticoid-responsive transcription factor, modulates inflammatory responses. Of relevance to asthma, expression of CEBPD in airway smooth muscle (ASM) increases with glucocorticoid exposure. We sought to characterize CEBPD-mediated transcriptomic responses to glucocorticoid exposure in ASM by measuring changes observed after knockdown of CEBPD and its impact on asthma-related ASM function. METHODS: Primary ASM cells derived from four donors were transfected with CEBPD or non-targeting (NT) siRNA and exposed to vehicle control, budesonide (100 nM, 18 h), TNFα (10 ng/ml, 18 h), or both budesonide and TNFα. Subsequently, RNA-Seq was used to measure gene expression levels, and pairwise differential expression results were obtained for exposures versus vehicle and knockdown versus control conditions. Weighted gene co-expression analysis was performed to identify groups of genes with similar expression patterns across the various experimental conditions (i.e., CEBPD knockdown status, exposures). RESULTS: CEBPD knockdown altered expression of 3037 genes under at least one exposure (q-value < 0.05). Co-expression analysis identified sets of 197, 152 and 290 genes that were correlated with CEBPD knockdown status, TNFα exposure status, and both, respectively. JAK-STAT signaling pathway genes, including IL6R and SOCS3, were among those influenced by both TNFα and CEBPD knockdown. Immunoblot assays revealed that budesonide-induced IL-6R protein expression and augmented IL-6-induced STAT3 phosphorylation levels were attenuated by CEBPD knockdown in ASM. CONCLUSIONS: CEBPD modulates glucocorticoid responses in ASM, in part via modulation of IL-6 receptor signaling.

Neighborhood Characteristics and COVID-19 Incidence and Mortality in Southeastern Pennsylvania.

The COVID-19 pandemic has differentially impacted people according to their race/ethnicity, socioeconomic status, and preexisting conditions. Public health surveillance efforts, especially those occurring early in the pandemic, did not gather nor report adequate individual-level demographic information to identify these differences, and thus, neighborhood-level characteristics were used to note striking disparities in the US. We sought to determine whether risk factors associated with COVID-19 incidence and mortality in five Southeastern Pennsylvania counties could be better understood by using neighborhood-level demographic data augmented with health, socioeconomic, and environmental characteristics derived from publicly available sources. Although we found that education level and age of residents were the most salient predictors of COVID-19 incidence and mortality, respectively, neighborhoods exhibited a high degree of segregation with multiple correlated factors, which limits the ability of neighborhood-level analysis to identify actionable factors underlying COVID-19 disparities.

Skin fibroblast metabolomic profiling reveals that lipid dysfunction predicts the severity of Friedreich's ataxia.

Friedreich's ataxia (FRDA) is an autosomal recessive neurodegenerative disorder caused by a triplet guanine-adenine-adenine (GAA) repeat expansion in intron 1 of the FXN gene, which leads to decreased levels of the frataxin protein. Frataxin is involved in the formation of iron-sulfur (Fe-S) cluster prosthetic groups for various metabolic enzymes. To provide a better understanding of the metabolic status of patients with FRDA, here we used patient-derived fibroblast cells as a surrogate tissue for metabolic and lipidomic profiling by liquid chromatography-high resolution mass spectrometry. We found elevated HMG-CoA and ß-hydroxybutyrate-CoA levels, implying dysregulated fatty acid oxidation, which was further demonstrated by elevated acyl-carnitine levels. Lipidomic profiling identified dysregulated levels of several lipid classes in FRDA fibroblast cells when compared with non-FRDA fibroblast cells. For example, levels of several ceramides were significantly increased in FRDA fibroblast cells; these results positively correlated with the GAA repeat length and negatively correlated with the frataxin protein levels. Furthermore, stable isotope tracing experiments indicated increased ceramide synthesis, especially for long-chain fatty acid-ceramides, in FRDA fibroblast cells compared with ceramide synthesis in healthy control fibroblast cells. In addition, PUFA-containing triglycerides and phosphatidylglycerols were enriched in FRDA fibroblast cells and negatively correlated with frataxin levels, suggesting lipid remodeling as a result of FXN deficiency. Altogether, we demonstrate patient-derived fibroblast cells exhibited dysregulated metabolic capabilities, and their lipid dysfunction predicted the severity of FRDA, making them a useful surrogate to study the metabolic status in FRDA.

Genome-wide association study in minority children with asthma implicates DNAH5 in bronchodilator responsiveness.

Variability in response to short-acting ß2-agonists (e.g., albuterol) among patients with asthma from diverse racial/ethnic groups may contribute to asthma disparities. We sought to identify genetic variants associated with bronchodilator response (BDR) to identify potential mechanisms of drug response and risk factors for worse asthma outcomes. Genome-wide association studies of bronchodilator response (BDR) were performed using TOPMed Whole Genome Sequencing data of the Asthma Translational Genomic Collaboration (ATGC), which corresponded to 1136 Puerto Rican, 656 Mexican and 4337 African American patients with asthma. With the population-specific GWAS results, a trans-ethnic meta-analysis was performed to identify BDR-associated variants shared across the three populations. Replication analysis was carried out in three pediatric asthma cohorts, including CAMP (Childhood Asthma Management Program; n = 560), GACRS (Genetics of Asthma in Costa Rica Study; n = 967) and HPR (Hartford-Puerto Rico; n = 417). A genome-wide significant locus (rs35661809; P = 3.61 × 10-8) in LINC02220, a non-coding RNA gene, was identified in Puerto Ricans. While this region was devoid of protein-coding genes, capture Hi-C data showed a distal interaction with the promoter of the DNAH5 gene in lung tissue. In replication analysis, the GACRS cohort yielded a nominal association (1-tailed P < 0.05). No genetic variant was associated with BDR at the genome-wide significant threshold in Mexicans and African Americans. Our findings help inform genetic underpinnings of BDR for understudied minority patients with asthma, but the limited availability of genetic data for racial/ethnic minority children with asthma remains a paramount challenge.

REALGAR: a web app of integrated respiratory omics data.

MOTIVATION: In the post genome-wide association study (GWAS) era, omics techniques have characterized information beyond genomic variants to include cell and tissue type-specific gene transcription, transcription factor binding sites, expression quantitative trait loci (eQTL) and many other biological layers. Analysis of omics data and its integration has in turn improved the functional interpretation of disease-associated genetic variants. Over 170 000 transcriptomic and epigenomic datasets corresponding to studies of various cell and tissue types under specific disease, treatment and exposure conditions are available in the Gene Expression Omnibus resource. Although these datasets are valuable to guide the design of experimental validation studies to understand the function of disease-associated genetic loci, in their raw form, they are not helpful to experimental researchers who lack adequate computational resources or experience analyzing omics data. We sought to create an integrated re-source of tissue-specific results from omics studies that is guided by disease-specific knowledge to facilitate the design of experiments that can provide biologically meaningful insights into genetic associations. RESULTS: We designed the Reducing Associations by Linking Genes and omics Results web app to provide multi-layered omics information based on results from GWAS, transcriptomic, epigenomic and eQTL studies for gene-centric analysis and visualization. With a focus on asthma datasets, the integrated omics results it contains facilitate the formulation of hypotheses related to airways disease-associated genes and can be addressed with experimental validation studies. AVAILABILITY AND IMPLEMENTATION: The REALGAR web app is available at: http://realgar.org/. The source code is available at: https://github.com/HimesGroup/realgar. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Epinephrine evokes shortening of human airway smooth muscle cells following ß2 adrenergic receptor desensitization.

Epinephrine (EPI), an endogenous catecholamine involved in the body's fight-or-flight responses to stress, activates α1-adrenergic receptors (α1ARs) expressed on various organs to evoke a wide range of physiological functions, including vasoconstriction. In the smooth muscle of human bronchi, however, the functional role of EPI on α1ARs remains controversial. Classically, evidence suggests that EPI promotes bronchodilation by stimulating ß2-adrenergic receptors (ß2ARs). Conventionally, the selective ß2AR agonism of EPI was thought to be, in part, due to a predominance of ß2ARs and/or a sparse, or lack of α1AR activity in human airway smooth muscle (HASM) cells. Surprisingly, we find that HASM cells express a high abundance of ADRA1B (the α1AR subtype B) and identify a spontaneous "switch-like" activation of α1ARs that evokes intracellular calcium, myosin light chain phosphorylation, and HASM cell shortening. The switch-like responses, and related EPI-induced biochemical and mechanical signals, emerged upon pharmacological inhibition of ß2ARs and/or under experimental conditions that induce ß2AR tachyphylaxis. EPI-induced procontractile effects were abrogated by an α1AR antagonist, doxazosin mesylate (DM). These data collectively uncover a previously unrecognized feed-forward mechanism driving bronchospasm via two distinct classes of G protein-coupled receptors (GPCRs) and provide a basis for reexamining α1AR inhibition for the management of stress/exercise-induced asthma and/or ß2-agonist insensitivity in patients with difficult-to-control, disease subtypes.

Inhibition of ABCC1 Decreases cAMP Egress and Promotes Human Airway Smooth Muscle Cell Relaxation.

In most living cells, the second-messenger roles for adenosine 3',5'-cyclic monophosphate (cAMP) are short-lived, confined to the intracellular space, and tightly controlled by the binary switch-like actions of Gαs (stimulatory G protein)-activated adenylyl cyclase (cAMP production) and cAMP-specific PDE (cAMP breakdown). Here, by using human airway smooth muscle (HASM) cells in culture as a model, we report that activation of the cell-surface ß2AR (ß2-adrenoceptor), a Gs-coupled GPCR (G protein-coupled receptor), evokes cAMP egress to the extracellular space. Increased extracellular cAMP levels ([cAMP]e) are long-lived in culture and are induced by receptor-dependent and receptor-independent mechanisms in such a way as to define a universal response class of increased intracellular cAMP levels ([cAMP]i). We find that HASM cells express multiple ATP-binding cassette (ABC) membrane transporters, with ABCC1 (ABC subfamily member C 1) being the most highly enriched transcript mapped to MRPs (multidrug resistance-associated proteins). We show that pharmacological inhibition or downregulation of ABCC1 with siRNA markedly reduces ß2AR-evoked cAMP release from HASM cells. Furthermore, inhibition of ABCC1 activity or expression decreases basal tone and increases ß-agonist-induced HASM cellular relaxation. These findings identify a previously unrecognized role for ABCC1 in the homeostatic regulation of [cAMP]i in HASM that may be conserved traits of the Gs-GPCRs (Gs-coupled family of GPCRs). Hence, the general features of this activation mechanism may uncover new disease-modifying targets in the treatment of airflow obstruction in asthma. Surprisingly, we find that serum cAMP levels are elevated in a small cohort of patients with asthma as compared with control subjects, which warrants further investigation.

Release of particulate matter from nano-enabled building materials (NEBMs) across their lifecycle: Potential occupational health and safety implications.

The present study investigates potential nanomaterial releases and occupational health risks across the lifecycle of nano-enabled building materials (NEBMs), namely, insulations and coatings. We utilized real-world degradation scenarios of a) sanding (mechanical), b) incineration (thermal), and c) accelerated UV-aging (environmental) followed by incineration. Extensive physicochemical characterization of the released lifecycle particulate matter (LCPM) was performed. The LCPM2.5 aerosol size fraction was used to assess the acute biological, cytotoxic and inflammatory effects on Calu-3 human lung epithelial cells. RNA-Seq analysis of exposed cells was performed to assess potential for systemic disease. Findings indicated that release dynamics and characteristics of LCPM depended on both the NEBM composition and the degradation scenario(s). Incineration emitted a much higher nanoparticle number concentration than sanding (nearly 4 orders of magnitude), which did not change with prior UV-aging. Released nanofillers during sanding were largely part of the matrix fragments, whereas those during incineration were likely physicochemically transformed. The LCPM from incineration showed higher bioactivity and inflammogenicity compared to sanding or sequential UV-aging and incineration, and more so when metallic nanofillers were present (such as Fe2O3). Overall, the study highlights the need for considering real-world exposure and toxicological data across the NEBM lifecycle to perform adequate risk assessments and to ensure workplace health and safety.