Search

Canonical histone messenger RNAs (mRNAs) are transcribed during S phase and do not terminate with a poly(A) tail at the 3′ end. Instead, the histone mRNAs display a stem-loop structure at their 3-end. Stem-loop-binding protein (SLBP) binds the stem-loop and regulates canonical histone mRNA metabolism. We previously demonstrated that exposure to arsenic, an environmental carcinogen, induces polyadenylation of canonical histone H3.1 mRNA, causing transformation of human cells in vitro. Arsenic decreased cellular levels of SLBP by inducing its proteasomal degradation and inhibiting SLBP transcription via epigenetic mechanisms. Similarly, we also reported that nickel and arsenic have similar effects on canonical histone mRNA transcription and translation. Most recently, we further demonstrated that bisphenols’ exposure increased polyadenylation of canonical histone H3.1 mRNA possibly through down-regulation of SLBP expression. This facilitates the abnormal stability of at least one canonical histone isoform (H3.1), and also increases H3 protein levels. Excess expression of canonical histones have been shown to increase sensitivity to DNA damage as well as increase the frequency of missing chromosomes and induce genomic instability. Thus, polyadenylation of canonical histone mRNA following arsenic, nickel and bisphenols exposure may contribute to metal and bisphenol-induced carcinogenesis.

Impaired sphingolipid synthesis is linked genetically to childhood asthma and functionally to airway hyperreactivity (AHR). The objective was to investigate whether sphingolipid synthesis could be a target for asthma therapeutics. The effects of GlyH-101 and fenretinide via modulation of de novo sphingolipid synthesis on AHR was evaluated in mice deficient in SPT (serine palmitoyl-CoA transferase), the rate-limiting enzyme of sphingolipid synthesis. The drugs were also used directly in human airway smooth-muscle and epithelial cells to evaluate changes in de novo sphingolipid metabolites and calcium release. GlyH-101 and fenretinide increased sphinganine and dihydroceramides (de novo sphingolipid metabolites) in lung epithelial and airway smooth-muscle cells, decreased the intracellular calcium concentration in airway smooth-muscle cells, and decreased agonist-induced contraction in proximal and peripheral airways. GlyH-101 also decreased AHR in SPT-deficient mice in vivo. This study identifies the manipulation of sphingolipid synthesis as a novel metabolic therapeutic strategy to alleviate AHR.

Vascular changes occur early in the development of obstructive airways disease. However, the vascular remodeling and dysfunction due to World Trade Center-Particulate Matter (WTC-PM) exposure are not well described and are therefore the focus of this investigation. C57Bl/6 female mice oropharyngeally aspirated 200 µg of WTC-PM53 or phosphate-buffered saline (PBS) (controls). 24-hours (24-hrs) and 1-Month (1-M) after exposure, echocardiography, micro-positron emission tomography(µ-PET), collagen quantification, lung metabolomics, assessment of antioxidant potential and soluble-receptor for advanced glycation end products (sRAGE) in bronchoalveolar lavage(BAL) and plasma were performed. 24-hrs post-exposure, there was a significant reduction in (1) Pulmonary artery(PA) flow-velocity and pulmonary ejection time(PET) (2) Pulmonary acceleration time(PAT) and PAT/PET, while (3) Aortic ejection time(AET) and velocity time integral(VTI) were increased, and (4) Aortic acceleration time (AAT)/AET, cardiac output and stroke volume were decreased compared to controls. 1-M post-exposure, there was also significant reduction of right ventricular diameter as right ventricle free wall thickness was increased and an increase in tricuspid E, A peaks and an elevated E/A. The pulmonary and cardiac standard uptake value and volume 1-M post-exposure was significantly elevated after PM-exposure. Similarly, α-smooth muscle actin(α-SMA) expression, aortic collagen deposition was elevated 1-M after PM exposure. In assessment of the metabolome, prominent subpathways included advanced glycation end products (AGEs), phosphatidylcholines, sphingolipids, saturated/unsaturated fatty acids, eicosanoids, and phospholipids. BAL superoxide dismutase(SOD), plasma total-antioxidant capacity activity, and sRAGE (BAL and plasma) were elevated after 24-hrs. PM exposure and associated vascular disease are a global health burden. Our study shows persistent WTC-Cardiorespiratory and Vascular Dysfunction (WTC-CaRVD), inflammatory changes and attenuation of antioxidant potential after PM exposure. Early detection of vascular disease is crucial to preventing cardiovascular deaths and future work will focus on further identification of bioactive therapeutic targets.

The 17q21 asthma susceptibility locus includes asthma risk alleles associated with decreased sphingolipid synthesis, likely resulting from increased expression of ORMDL3. ORMDL3 inhibits serine-palmitoyl transferase (SPT), the rate-limiting enzyme of de novo sphingolipid synthesis. There is evidence that decreased sphingolipid synthesis is critical to asthma pathogenesis. Children with asthma and 17q21 asthma risk alleles display decreased sphingolipid synthesis in blood cells. Reduced SPT activity results in airway hyperreactivity, a hallmark feature of asthma. 17q21 asthma risk alleles are also linked to childhood infections with human rhinovirus (RV). This study evaluates the interaction of RV with the de novo sphingolipid synthesis pathway, and the alterative effects of concurrent SPT inhibition in SPT-deficient mice and human airway epithelial cells. In mice, RV infection shifted lung sphingolipid synthesis gene expression to a pattern that resembles genetic SPT deficiency, including decreased expression of Sptssa, a small SPT subunit. This pattern was pronounced in lung epithelial cellular adhesion molecule (EpCAM(+)) cells and reproduced in human bronchial epithelial cells. RV did not affect Sptssa expression in lung CD45(+) immune cells. RV increased sphingolipids unique to the de novo synthesis pathway in mouse lung and human airway epithelial cells. Interestingly, these de novo sphingolipid species were reduced in the blood of RV-infected wild-type mice. RV exacerbated SPT deficiency–associated airway hyperreactivity. Airway inflammation was similar in RV-infected wild-type and SPT-deficient mice. This study reveals the effects of RV infection on the de novo sphingolipid synthesis pathway, elucidating a potential mechanistic link between 17q21 asthma risk alleles and rhinoviral infection.

Vascular changes occur early in the development of obstructive airways disease. However, the vascular remodeling and dysfunction due to World Trade Center-Particulate Matter (WTC-PM) exposure are not well described and are therefore the focus of this investigation. C57Bl/6 female mice oropharyngeally aspirated 200 µg of WTC-PM

Background Metabolic syndrome (MetSyn) predicted future development of World Trade Center lung injury (WTC-LI) in a subgroup of firefighters who never smoked and were male. An intracohort validation of MetSyn as a predictor of WTC-LI is examined in the cohort exposed to the World Trade Center (WTC) that has been followed longitudinally for 16 years. Methods Results of pulmonary function tests (n = 98,221) in workers exposed to the WTC (n = 9,566) were evaluated. A baseline cohort of firefighters who had normal FEV1 before 9/11 and who had had serum drawn before site closure on July 24, 2002 (n = 7,487) was investigated. Case subjects with WTC-LI (n = 1,208) were identified if they had at least two measured instances of FEV1 less than the lower limit of normal (LLN). Cox proportional hazards modeled early MetSyn biomarker ability to predict development of FEV1 less than the LLN. Results Case subjects were more likely to smoke, be highly exposed, and have MetSyn. There was a significant exposure dose response; the individuals most highly exposed had a 30.1% increased risk of developing WTC-LI, having MetSyn increased risk of developing WTC-LI by 55.7%, and smoking increased risk by 15.2%. There was significant interaction between smoking and exposure. Conclusions We validated the usefulness of MetSyn to predict future WTC-LI in a larger population of individuals who were exposed. MetSyn defined by dyslipidemia, insulin resistance, and cardiovascular disease suggests that systemic inflammation can contribute to future lung function loss.

Introduction: Bisphenol A (BPA) is a pervasive chemical exposure in the US and has been linked to adverse health effects in humans and mainly identified as an endocrine disruptor. However, recent studies suggests that all plastics including our daily usages for food/drink containers may leach chemicals if they are scratched or heated or stored long term and strongly suggests that at certain exposure levels of BPA in these products, may cause cancers including breast, lung, and ovarian cancers in humans. Although there are few studies about breast, lung and ovarian cancers, with BPA exposure there is an urgent need to focus on the BPA’s carcinogenic activity in the lung. Because lung cancers can progress to life threatening events and short life span once it is diagnosed, identifying the mechanism that specifically inhibits/prevents lung cancers invasion and related morbidity is of tremendous importance for reducing mortality. Therefore, in this study, we investigated the carcinogenicity of BPA using human bronchial epithelial cells. Experimental methods: To determine whether BPA alters canonical histone mRNA processing in vitro, we measured levels of polyadenylation (polyA) of canonical histone (H)3.1 mRNA as well as protein expression of Stem-loop binding protein (SLBP), and H3 protein in human bronchial epithelial BEAS-2B cells exposed to various concentrations of BPA for 96 h. Furthermore, BEAS-2B cells were chronically exposed to low doses of BPA, the cell transformation assay was performed in an anchorage-independent growth and colony formation was assessed. Arsenic was used as a positive control because our laboratory previously demonstrated that arsenic-induced polyA of H3.1 mRNA, by depletion of SLBP in vitro and that polyA of H3.1 mRNA enhanced tumor formation in nude mice. Results: Our results showed that exposure of BEAS-2B cells to BPA depleted SLBP, induced polyA of canonical histone mRNAs, and upregulated H3 protein. The results from real-time quantitative PCR showed that BPA exposure increased level of polyA H3.1 mRNA. Furthermore, our findings from an anchorage-independent growth assay also indicate that exposure of BEAS-2B cells to low doses of BPA induced malignant cell transformation. Conclusions: The present study demonstrated that chronic exposure of the cells to BPA causes malignant cell transformation, indicating that BPA is a potent human carcinogen to induce lung cancer. Our study also demonstrated that the loss of SLBP and gain of polyA H3.1 mRNA play an important role in BPA-induced carcinogenesis. Citation Format: Arul Veerappan, Zhou Zhang, Max Costa. Depletion of stem-loop binding protein and elevation of polyadenylation of histone 3.1 contribute to malignant cell transformation induced by bisphenol A [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 228.

Fire Department of New York (FDNY) rescue and recovery workers exposed to World Trade Center (WTC) particulates suffered loss of forced expiratory volume in 1 s (FEV1). Metabolic Syndrome increased the risk of developing WTC-lung injury (WTC-LI). We aim to attenuate the deleterious effects of WTC exposure through a dietary intervention targeting these clinically relevant disease modifiers. We hypothesize that a calorie-restricted Mediterranean dietary intervention will improve metabolic risk, subclinical indicators of cardiopulmonary disease, quality of life, and lung function in firefighters with WTC-LI. To assess our hypothesis, we developed the Food Intake REstriction for Health OUtcome Support and Education (FIREHOUSE), a randomized controlled clinical trial (RCT). Male firefighters with WTC-LI and a BMI &gt, 27 kg/m2 will be included. We will randomize subjects (1:1) to either: (1) Low Calorie Mediterranean (LoCalMed)&mdash, an integrative multifactorial, technology-supported approach focused on behavioral modification, nutritional education that will include a self-monitored diet with feedback, physical activity recommendations, and social cognitive theory-based group counseling sessions, or (2) Usual Care. Outcomes include reduction in body mass index (BMI) (primary), improvement in FEV1, fractional exhaled nitric oxide, pulse wave velocity, lipid profiles, targeted metabolic/clinical biomarkers, and quality of life measures (secondary). By implementing a technology-supported LoCalMed diet our FIREHOUSE RCT may help further the treatment of WTC associated pulmonary disease.

Pulmonary disease after World Trade Center particulate matter (WTC-PM) exposure is associated with dyslipidemia and the receptor for advanced glycation end products (RAGE); however, the mechanisms are not well understood. We used a murine model and a multiomics assessment to understand the role of RAGE in the pulmonary long-term effects of a single high-intensity exposure to WTC-PM. After 1 month, WTC-PM–exposed wild-type (WT) mice had airway hyperreactivity, whereas RAGE-deficient (Ager(−/−)) mice were protected. PM-exposed WT mice also had histologic evidence of airspace disease, whereas Ager(−/−) mice remained unchanged. Inflammatory mediators such as G-CSF (granulocyte colony–stimulating factor), IP-10 (IFN-γ–induced protein 10), and KC (keratinocyte chemoattractant) were differentially expressed after WTC-PM exposure. WTC-PM induced α-SMA, DIAPH1 (protein diaphanous homolog 1), RAGE, and significant lung collagen deposition in WT compared with Ager(−/−) mice. Compared with WT mice with PM exposure, relative expression of phosphorylated to total CREB (cAMP response element–binding protein) and JNK (c-Jun N-terminal kinase) was significantly increased in the lung of PM-exposed Ager(−/−) mice, whereas Akt (protein kinase B) was decreased. Random forests of the refined lung metabolomic profile classified subjects with 92% accuracy; principal component analysis captured 86.7% of the variance in three components and demonstrated prominent subpathway involvement, including known mediators of lung disease such as vitamin B(6) metabolites, sphingolipids, fatty acids, and phosphatidylcholines. Treatment with a partial RAGE antagonist, pioglitazone, yielded similar fold-change expression of metabolites (N(6)-carboxymethyllysine, 1-methylnicotinamide, N(1)+N(8)-acetylspermidine, and succinylcarnitine [C4-DC]) between WT and Ager(−/−) mice exposed to WTC-PM. RAGE can mediate WTC-PM–induced airway hyperreactivity and warrants further investigation.

The terrorist attacks on the World Trade Center (WTC) created an unprecedented environmental exposure to aerosolized dust, gases and potential carcinogens. Clonal hematopoiesis (CH) is defined as the acquisition of somatic mutations in blood cells and is associated with smoking and exposure to genotoxic stimuli. Here we show that deep targeted sequencing of blood samples identified a significantly higher proportion of WTC-exposed first responders with CH (10%; 48 out of 481) when compared with non-WTC-exposed firefighters (6.7%; 17 out of 255; odds ratio, 3.14; 95% confidence interval, 1.64-6.03; P = 0.0006) after controlling for age, sex and race/ethnicity. The frequency of somatic mutations in WTC-exposed first responders showed an age-related increase and predominantly affected DNMT3A, TET2 and other CH-associated genes. Exposure of lymphoblastoid cells to WTC particulate matter led to dysregulation of DNA replication at common fragile sites in vitro. Moreover, mice treated with WTC particulate matter developed an increased burden of mutations in hematopoietic stem and progenitor cell compartments. In summary, the high burden of CH in WTC-exposed first responders provides a rationale for enhanced screening and preventative efforts in this population.

BACKGROUND: Metabolic syndrome (MetSyn) predicted future development of World Trade Center lung injury (WTC-LI) in a subgroup of firefighters who never smoked and were male. An intracohort validation of MetSyn as a predictor of WTC-LI is examined in the cohort exposed to the World Trade Center (WTC) that has been followed longitudinally for 16 years. METHODS: Results of pulmonary function tests (n = 98,221) in workers exposed to the WTC (n = 9,566) were evaluated. A baseline cohort of firefighters who had normal FEV(1) before 9/11 and who had had serum drawn before site closure on July 24, 2002 (n = 7,487) was investigated. Case subjects with WTC-LI (n = 1,208) were identified if they had at least two measured instances of FEV(1) less than the lower limit of normal (LLN). Cox proportional hazards modeled early MetSyn biomarker ability to predict development of FEV(1) less than the LLN. RESULTS: Case subjects were more likely to smoke, be highly exposed, and have MetSyn. There was a significant exposure dose response; the individuals most highly exposed had a 30.1% increased risk of developing WTC-LI, having MetSyn increased risk of developing WTC-LI by 55.7%, and smoking increased risk by 15.2%. There was significant interaction between smoking and exposure. CONCLUSIONS: We validated the usefulness of MetSyn to predict future WTC-LI in a larger population of individuals who were exposed. MetSyn defined by dyslipidemia, insulin resistance, and cardiovascular disease suggests that systemic inflammation can contribute to future lung function loss.

Introduction The World Trade Center (WTC) disaster exposed first responders to high levels of aerosolized carcinogens (Lioy et. al. Env. Health Perspect 2002). Clonal hematopoiesis is associated with exposure to smoking and genotoxic stimuli (Jaiswal et. al. NEJM 2014; Genovese et. al. NEJM 2015). We sought to determine its incidence in WTC-exposed first responders. We also assessed the effect of WTC particulate matter (WTC-PM) on genome integrity in vitro, and in murine studies. Methods Deep targeted sequencing was performed on blood collected from 481 first responders (429 WTC-exposed firefighters, 52 WTC-exposed emergency medical service workers) and 52 non-exposed first responders. Samples were analyzed for 237 genes mutated in hematologic malignancies and interpreted using reference databases. Non synonymous somatic mutations were annotated and analyzed. Results In the WTC-exposed cohort, 57 individuals with 66 somatic mutations of expected pathogenic potential were identified (overall prevalence 11.9%). In the non-exposed cohort, only one pathogenic mutation was found in the IDH2 gene (overall prevalence 1.9%). There was a strong association between increasing age and prevalence of mutations in the WTC-exposed cohort (Fig 1A). DNMT3A (16/66), TET2 (7/66), SF3B1 and SRSF2 (3/66 each) were the most common genes identified in the WTC-exposed cohort (Fig 1B). Median VAF was 12% and missense mutations were most frequent alteration. Aging, smoking, DNA repair and alkylating agent exposure related mutational signatures were observed with a cytosine to thymine (C→T) transition being most common. Next, we assessed the effect of WTC-PM on genome integrity and replication in vitro. WTC-PM that was collected in the first three days after 9/11 was used in concentrations mimicking exposure levels. Lymphocytes exposed to WTC-PM demonstrated a significant increase in phosphorylated H2AX foci accumulation, suggesting a DNA damage response (Fig 2). Since common fragile sites (CFSs) detect basal levels of stress in the cell, and activate DNA damage response (DDR), we profiled DNA replication dynamics at CFS-FRA16D at very high resolution using the single molecule analysis of replicated DNA (SMARD) assay. Treatment with WTC-PM significantly altered replication at two common fragile sites (regions 1 and 2 of FRA16D, Fig 3A) with replication pausing being observed at multiple sites (Fig 3B-I, white rectangles). Striking increase in replication initiation was seen, characterized as dormant origins activated to rescue replication pausing (Fig 3E, J). These alterations were accompanied by a corresponding increase in replication speed, conditions that lead to DNA replication errors and mutagenesis (Fig 3F, K). Next, we treated mice with WTC-PM via the oropharyngeal route to mimic first responder exposures, and then harvested and analyzed their bone marrow compartments. Significant expansion of hematopoietic stem cells (Kit+, Sca1+, Lineage-ve, KSL) was seen in WTC-PM treated mice (Fig 4A,B). Whole genome sequencing of sorted stem cells showed a significant increase in non-synonymous SNPs, deletions and indels in the WTC-PM treated samples when compared to control (Fig 4C-E). These genomic alterations were found to occur at low VAF throughout the whole genome, demonstrating widespread genotoxic effects of WTC-PM on hematopoietic stem cells in vivo (Fig 4F). Discussion We report a high burden of mutations in 11.9% (57/481) WTC-exposed first responders compared to the non-exposed cohort (1.9%, 1/52). The frequency of the somatic mutations was many fold higher than in previous studies (Jaiswal et. al. NEJM 2014; Genovese et. al. NEJM, 2015). In the 50-59 year age group, 10% of WTC-exposed individuals carried somatic mutations, compared to the frequency of 2.5% reported by Jaiswal et. al. for the same age group. Despite deeper sequencing performed in our study, the median VAF in our study was 12%, indicating that the difference in technique did not bias our study towards increased detection of small, subclinical clones when compared to previous studies. Furthermore, we demonstrate that WTC-PM can perturb DNA replication and increased genomic instability in vivo, potentially leading to higher burden of clonal hematopoiesis in WTC-exposed first responders. These results demonstrate adverse environmental exposures can be associated with a high rate of clonal hematopoiesis. Disclosures Landgren: Sanofi: Membership on an entity's Board of Directors or advisory committees; Adaptive: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Merck: Other: IDMC; Theradex: Other: IDMC; Abbvie: Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Karyopharm: Membership on an entity's Board of Directors or advisory committees. Fletcher:Genoptix/Neogenomics: Employment. Ebert:Broad Institute: Other: Contributor to a patent filing on this technology that is held by the Broad Institute.; Celgene: Research Funding; Deerfield: Research Funding. Steidl:GlaxoSmithKline: Research Funding; Celgene: Consultancy; Aileron Therapeutics: Consultancy, Research Funding; Stelexis Therapeutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Other: Scientific Co-Founder; Pieries Pharmaceuticals: Consultancy; BayerHealthcare: Consultancy, Research Funding; Novartis: Consultancy, Research Funding. Will:Novartis Pharmaceuticals: Research Funding. Verma:Stelexis: Equity Ownership, Honoraria; Acceleron: Honoraria; Celgene: Honoraria; BMS: Research Funding; Janssen: Research Funding.

BackgroundOur group has identified the receptor for advanced glycation end-products (RAGE) as a predictor of World Trade Center particulate matter associated lung injury. The aim of this systematic review is to assess the relationship between RAGE and obstructive airways disease secondary to environmental exposure.MethodsA comprehensive search using PubMed and Embase was performed on January 5, 2018 utilising keywords focusing on environmental exposure, obstructive airways disease and RAGE and was registered with PROSPERO (CRD42018093834). We included original human research studies in English, focusing on pulmonary end-points associated with RAGE and environmental exposure.ResultsA total of 213 studies were identified by the initial search. After removing the duplicates and applying inclusion and exclusion criteria, we screened the titles and abstracts of 61 studies. Finally, 19 full-text articles were included. The exposures discussed in these articles include particulate matter (n=2) and cigarette smoke (n=17).ConclusionRAGE is a mediator of inflammation associated end-organ dysfunction such as obstructive airways disease. Soluble RAGE, a decoy receptor, may have a protective effect in some pulmonary processes. Overall, RAGE is biologically relevant in environmental exposure associated lung disease. Future investigations should focus on further understanding the role and therapeutic potential of RAGE in particulate matter exposure associated lung disease.

Particulate matter (PM) exposure and metabolic syndrome (MetSyn) are both significant global health burdens. PM exposure has been implicated in the pathogenesis of MetSyn and cardiopulmonary diseases. Individuals with pre-existing MetSyn may be more susceptible to the detrimental effects of PM exposure. Our aim was to provide a narrative review of MetSyn/PM-induced systemic inflammation in cardiopulmonary disease, with a focus on prior studies of the World Trade Center (WTC)-exposed Fire Department of New York (FDNY). We included studies (1) published within the last 16-years; (2) described the epidemiology of MetSyn, obstructive airway disease (OAD), and vascular disease in PM-exposed individuals; (3) detailed the known mechanisms of PM-induced inflammation, MetSyn and cardiopulmonary disease; and (4) focused on the effects of PM exposure in WTC-exposed FDNY firefighters. Several investigations support that inhalation of PM elicits pulmonary and systemic inflammation resulting in MetSyn and cardiopulmonary disease. Furthermore, individuals with these preexisting conditions are more sensitive to PM exposure-related inflammation, which can exacerbate their conditions and increase their risk for hospitalization and chronic disease. Mechanistic research is required to elucidate biologically plausible therapeutic targets of MetSyn- and PM-induced cardiopulmonary disease.

Pulmonary fibrosis is characterized by an inflammatory response that includes macrophages, neutrophils, lymphocytes, and mast cells. The purpose of this study was to evaluate whether mast cells play a role in initiating pulmonary fibrosis. Pulmonary fibrosis was induced with bleomycin in mast-cell-deficient WBB6F1-W/W(v) (MCD) mice and their congenic controls (WBB6F1-(+)/(+)). Mast cell deficiency protected against bleomycin-induced pulmonary fibrosis, but protection was reversed with the re-introduction of mast cells to the lungs of MCD mice. Two mast cell mediators were identified as fibrogenic: histamine and renin, via angiotensin (ANG II). Both human and rat lung fibroblasts express the histamine H1 and ANG II AT1 receptor subtypes and when activated, they promote proliferation, transforming growth factor β1 secretion, and collagen synthesis. Mast cells appear to be critical to pulmonary fibrosis. Therapeutic blockade of mast cell degranulation and/or histamine and ANG II receptors should attenuate pulmonary fibrosis.

Chronic lung disease of prematurity (CLD) is a frequent sequela of premature birth and oxygen toxicity is a major associated risk factor. Impaired alveolarization, scarring, and inflammation are hallmarks of CLD. Mast cell hyperplasia is a feature of CLD but the role of mast cells in its pathogenesis is unknown. We hypothesized that mast cell hyperplasia is a consequence of neonatal hyperoxia and contributes to CLD. Additionally, mast cell products may have diagnostic and prognostic value in preterm infants predisposed to CLD. To model CLD, neonatal wild-type and mast cell-deficient mice were placed in an O2chamber delivering hyperoxic gas mixture [inspired O2fraction (FiO2) of 0.8] (HO) for 2 wk and then returned to room air (RA) for an additional 3 wk. Age-matched controls were kept in RA (FiO2of 0.21). Lungs from HO mice had increased numbers of mast cells, alveolar simplification and enlargement, and increased lung compliance. Mast cell deficiency proved protective by preserving air space integrity and lung compliance. The mast cell mediators β-hexosaminidase (β-hex), histamine, and elastase increased in the bronchoalveolar lavage fluid of HO wild-type mice. Tracheal aspirate fluids (TAs) from oxygenated and mechanically ventilated preterm infants were analyzed for mast cell products. In TAs from infants with confirmed cases of CLD, β-hex was elevated over time and correlated with FiO2. Mast cell exosomes were also present in the TAs. Collectively, these data show that mast cells play a significant role in hyperoxia-induced lung injury and their products could serve as potential biomarkers in evolving CLD.

Asthma is a clinically heterogeneous genetic disease, and its pathogenesis is incompletely understood. Genome-wide association studies link ORM (yeast)-Like protein isoform 3 [corrected] (ORMDL3), a member of the ORM gene family, to nonallergic childhood-onset asthma. Orm proteins negatively regulate sphingolipid (SL) synthesis by acting as homeostatic regulators of serine palmitoyl-CoA transferase (SPT), the rate-limiting enzyme of de novo SL synthesis, but it is not known how SPT activity or SL synthesis is related to asthma. The present study analyzes the effect of decreased de novo SL synthesis in the lung on airway reactivity after administration of myriocin, an inhibitor of SPT, and in SPT heterozygous knockout mice. We show that, in both models, decreased de novo SL synthesis increases bronchial reactivity in the absence of inflammation. Decreased SPT activity affected intracellular magnesium homeostasis and altered the bronchial sensitivity to magnesium. This functionally links decreased de novo SL synthesis to asthma and so identifies this metabolic pathway as a potential target for therapeutic interventions.

Mast cells are associated with inflammation and fibrosis. Whether they protect against or contribute to renal fibrosis is unclear. Based on our previous findings that mast cells can express and secrete active renin, and that angiotensin (ANG II) is profibrotic, we hypothesized that mast cells play a critical role in tubulointerstitial fibrosis. We tested this hypothesis in the 14-day unilateral ureteral obstruction (UUO) model in rats and mast cell-deficient (MCD) mice (WBB6F1-W/Wv) and their congenic controls (CC). In the 14-day UUO rat kidney, mast cell number is increased and they express active renin. Stabilizing mast cells in vivo with administration of cromolyn sodium attenuated the development of tubulointerstitial fibrosis, which was confirmed by measuring newly synthesized pepsin-soluble collagen and blind scoring of fixed trichrome-stained kidney sections accompanied by spectral analysis. Fibrosis was absent in UUO kidneys from MCD mice unlike that observed in the CC mice. Losartan treatment reduced the fibrosis in the CC UUO kidneys. The effects of mast cell degranulation and renin release were tested in the isolated, perfused kidney preparation. Mast cell degranulation led to renin-dependent protracted flow recovery. This demonstrates that mast cell renin is active in situ and the ensuing ANG II can modulate intrarenal vascular resistance in the UUO kidney. Collectively, the data demonstrate that mast cells are critical to the development of renal fibrosis in the 14-day UUO kidney. Since renin is present in human kidney mast cells, our work identifies potential targets in the treatment of renal fibrosis.

Objective: To evaluate whether National Institute of Child Health and Human Health and Development (NICHD) fetal heart rate categories were predictive of neonatal survival in periviable pregnancies. Methods: We reviewed the charts of 57 infants delivered at 23 and 24 weeks' gestation. Fetal heart rate tracings were evaluated following the NICHD 2008 criteria, using the acceleration height of 10 bpm and duration of 10 s. Multiple logistic regression analyses were performed using survival, fetal morbidities, and cord pH < 7.1 as dependent variables. Independent variables included fetal heart rate category, mode of delivery, resuscitation, and histological chorioamnionitis. Outcomes of infants delivered at 23 and 24 weeks were also compared. Results: In 23-week pregnancies, fetal heart rate category 2 was associated with improved short-term survival compared to category 3 (OR 1.3, 95% CI 0.11-15.7). Cesarean delivery and histological chorioamnionitis were not predictive of survival [(OR 0.5, 95% CI 0.04-7.1, and OR 0.4, 95% CI 0.02-6.85), respectively]. Long-term survival for infants born at 23 and 24 weeks was 8% and 56%, respectively. Conclusions: The NICHD fetal heart rate category during labor may be associated with survival for infants born at 23 and 24 weeks of gestation. Cesarean delivery was not associated with improved survival.

We previously reported that mast cells express renin, the rate-limiting enzyme in the renin–angiotensin cascade. We have now assessed whether mast cell renin release triggers angiotensin formation in the airway. In isolated rat bronchial rings, mast cell degranulation released enzyme with angiotensin I-forming activity blocked by the selective renin inhibitor BILA2157. Local generation of angiotensin (ANG II) from mast cell renin elicited bronchial smooth muscle contraction mediated by ANG II type 1 receptors (AT1R). In a guinea pig model of immediate type hypersensitivity, anaphylactic mast cell degranulation in bronchial rings resulted in ANG II-mediated constriction. As in rat bronchial rings, bronchoconstriction (BC) was inhibited by a renin inhibitor, an AT1R blocker, and a mast cell stabilizer. Anaphylactic release of renin, histamine, and β-hexosaminidase from mast cells was confirmed in the effluent from isolated, perfused guinea pig lung. To relate the significance of this finding to humans, mast cells were isolated from macroscopically normal human lung waste tissue specimens. Sequence analysis of human lung mast cell RNA showed 100% homology between human lung mast cell renin and kidney renin between exons 1 and 10. Furthermore, the renin protein expressed in lung mast cells was enzymatically active. Our results demonstrate the existence of an airway renin–angiotensin system triggered by release of mast-cell renin. The data show that locally produced ANG II is a critical factor governing BC, opening the possibility for novel therapeutic targets in the management of airway disease.

Background: We recently reported that murine and cavian heart mast cells are a unique extrarenal source of renin. Ischemia/reperfusion releases this renin leading to local angiotensin formation and norepinephrine release. As mast cells are a primary target of hypersensitivity, we assessed whether anaphylactic mast cell degranulation also results in renin and norepinephrine release. Methods: Hearts isolated from presensitized guinea pigs were challenged with antigen. Results: Cardiac anaphylaxis was characterized by mast cell degranulation, evidenced by β-hexosaminidase release and associated with renin and norepinephrine release. Mast cell stabilization with cromolyn or lodoxamide markedly attenuated the release of β-hexosaminidase, renin and norepinephrine. Renin inhibition with BILA2157 did not affect mast cell degranulation, but attenuated norepinephrine release. Conclusions: Our findings disclose that immediate-type hypersensitivity elicits renin release from mast cells, activating a local renin-angiotensin system, thereby promoting norepinephrine release. As renin is stored in human heart mast cells, allergic reactions could initiate renin release, leading to local angiotensin formation and hyperadrenergic dysfunction.

This study was designed to elucidate the toxicity of the widely used plant Aegle marmelos in rats. We have taken total alcoholic, total aqueous, whole aqueous and methanolic extracts isolated from the leaves of A. marmelos and studied their toxic effects. Acute, subacute and LD(50) values were determined in experimental rats. The dead animals were obtained from primary screening studies, LD(50) value determination experiments and acute studies subjected to postmortem studies. The external appearance of the dead animals, the appearance of the viscera, heart, lungs, stomach, intestine, liver, kidney, spleen and brain were carefully noted and any apparent and significant features or differences from the norm were recorded. Following the chronic administration of A. marmelos for 14 days, the vital organs such as heart, liver, kidney, testis, spleen and brain were carefully evaluated by histopathological studies and any apparent and significant changes or differences from the norm were studied. From the acute administration of A. marmelos, the LD(50) values were determined using graphical method. The hearts stopped in systolic stand-still in the acute experiments. There were no remarkable changes noticed in the histopathological studies after 50 mg/kg body wt of the extracts of A. marmelos when administered intraperitoneally for 14 days successively. Pathologically, neither gross abnormalities nor histopathological changes were observed. After calculation of LD(50) values using graphical methods, we found a broad therapeutic window and a high therapeutic index value for A. marmelos extracts. Intraperitoneal administration of the extracts of the leaves of A. marmelos at doses of 50, 70, 90 and 100 mg/kg body wt for 14 consecutive days to male and female Wistar rats did not induce any short-term toxicity. Collectively, these data demonstrate that the extracts of the leaves of A. marmelos have a high margin of drug safety.