PEBP1 acts as a rheostat between prosurvival autophagy and ferroptotic death in asthmatic epithelial cells.

Temporally harmonized elimination of damaged or unnecessary organelles and cells is a prerequisite of health. Under Type 2 inflammatory conditions, human airway epithelial cells (HAECs) generate proferroptotic hydroperoxy-arachidonoyl-phosphatidylethanolamines (HpETE-PEs) as proximate death signals. Production of 15-HpETE-PE depends on activation of 15-lipoxygenase-1 (15LO1) in complex with PE-binding protein-1 (PEBP1). We hypothesized that cellular membrane damage induced by these proferroptotic phospholipids triggers compensatory prosurvival pathways, and in particular autophagic pathways, to prevent cell elimination through programmed death. We discovered that PEBP1 is pivotal to driving dynamic interactions with both proferroptotic 15LO1 and the autophagic protein microtubule-associated light chain-3 (LC3). Further, the 15LO1-PEBP1-generated ferroptotic phospholipid, 15-HpETE-PE, promoted LC3-I lipidation to stimulate autophagy. This concurrent activation of autophagy protects cells from ferroptotic death and release of mitochondrial DNA. Similar findings are observed in Type 2 Hi asthma, where high levels of both 15LO1-PEBP1 and LC3-II are seen in HAECs, in association with low bronchoalveolar lavage fluid mitochondrial DNA and more severe disease. The concomitant activation of ferroptosis and autophagy by 15LO1-PEBP1 complexes and their hydroperoxy-phospholipids reveals a pathobiologic pathway relevant to asthma and amenable to therapeutic targeting.

Targeted resequencing showing novel common and rare genetic variants increases the risk of asthma in the Chinese Han population.

BACKGROUND: Although studies have identified hundreds of genetic variants associated with asthma risk, a large fraction of heritability remains unexplained, especially in Chinese individuals. METHODS: To identify genetic risk factors for asthma in a Han Chinese population, 211 asthma-related genes were first selected based on database searches. The genes were then sequenced for subjects in a Discovery Cohort (284 asthma patients and 205 older healthy controls) using targeted next-generation sequencing. Bioinformatics analysis and statistical association analyses were performed to reveal the associations between rare/common variants and asthma, respectively. The identified common risk variants underwent a validation analysis using a Replication Cohort (664 patients and 650 controls). RESULTS: First, we identified 18 potentially functional rare loss-of-function (LOF) variants in 21/284 (7.4%) of the asthma cases. Second, using burden tests, we found that the asthma group had nominally significant (p < 0.05) burdens of rare nonsynonymous variants in 10 genes. Third, 23 common single-nucleotide polymorphisms were associated with the risk of asthma, 7/23 (30.4%) and 9/23 (39.1%) of which were modestly significant (p < 9.1 × 10-4 ) in the Replication Cohort and Combined Cohort, respectively. According to our cumulative risk model involving the modestly associated alleles, middle- and high-risk subjects had a 2.0-fold (95% CI: 1.621-2.423, p = 2.624 × 10-11 ) and 6.0-fold (95% CI: 3.623-10.156, p = 7.086 × 10-12 ) increased risk of asthma, respectively, compared with low-risk subjects. CONCLUSION: This study revealed novel rare and common genetic risk factors for asthma, and provided a cumulative risk model for asthma risk prediction and stratification in Han Chinese individuals.

A nonsynonymous polymorphism (rs117179004, T392M) of hyaluronidase 1 (HYAL1) is associated with increased risk of idiopathic pulmonary fibrosis in Southern Han Chinese.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a genetic heterogeneous disease with high mortality and poor prognosis. Hyaluronidase 1 (HYAL1) was found to be upregulated in fibroblasts from IPF patients, and overexpression of HYAL1 could prevent human fetal lung fibroblast proliferation. However, the genetic correlation between the HYAL1 and IPF or connective tissue diseases related interstitial lung disease (CTD-ILD) has not been determined. METHODS: A two-stage study was conducted in Southern Han Chinese population. We sequenced the coding regions and flanking regulatory regions of HYAL1 in stage one (253 IPF cases and 125 controls). A statistically significant variant was further genotyped in stage two (162 IPF cases, 182 CTD-ILD cases, and 225 controls). RESULTS: We identified a nonsynonymous polymorphism (rs117179004, T392M) significantly associated with increased IPF risk (dominant model: OR = 2.239, 95% CI = 1.212-4.137, p = 0.010 in stage one; OR = 2.383, 95% CI = 1.376-4.128, p = 0.002 in stage two). However, we did not observe this association in CTD-ILD (OR = 1.401, 95% CI = 0.790-2.485, p = 0.248). CONCLUSION: Our findings suggest that the nonsynonymous polymorphism (rs117179004, T392M) may confer susceptibility to IPF in Southern Han Chinese, but is not associated with susceptibility to CTD-ILD.

15-Lipoxygenase 1 in nasal polyps promotes CCL26/eotaxin 3 expression through extracellular signal-regulated kinase activation.

BACKGROUND: 15-Lipoxygenase 1 (15LO1) is expressed in airway epithelial cells in patients with type 2-high asthma in association with eosinophilia. Chronic rhinosinusitis with nasal polyps (CRSwNP) is also associated with type 2 inflammation and eosinophilia. CCL26/eotaxin 3 has been reported to be regulated by 15LO1 in lower airway epithelial cells. However, its relation to 15LO1 in patients with CRSwNP or mechanisms for its activation are unclear. OBJECTIVE: We sought to evaluate 15LO1 and CCL26 expression in nasal epithelial cells (NECs) from patients with CRSwNP and healthy control subjects (HCs) and determine whether 15LO1 regulates CCL26 in NECs through extracellular signal-regulated kinase (ERK) activation. METHODS: 15LO1, CCL26, and phosphorylated ERK were evaluated in NECs from patients with CRSwNP and HCs. 15LO1/CCL26 and CCL26/cytokeratin 5 were colocalized by means of immunofluorescence. IL-13-stimulated NECs were cultured at an air-liquid interface with or without 15-lipoxygenase 1 gene (ALOX15) Dicer-substrate short interfering RNAs (DsiRNA) transfection, a specific 15LO1 enzymatic inhibitor, and 2 ERK inhibitors. Expression of 15LO1 and CCL26 mRNA and protein was analyzed by using quantitative RT-PCR, Western blotting, and ELISA. RESULTS: 15LO1 expression was increased in nasal polyp (NP) epithelial cells compared with middle turbinate epithelial cells from patients with CRSwNP and HCs. 15LO1 expression correlated with CCL26 expression and colocalized with CCL26 expression in basal cells of the middle turbinate and NPs from patients with CRSwNP. In primary NECs in vitro, IL-13 induced 15LO1 and CCL26 expression. 15LO1 knockdown and inhibition decreased IL-13-induced ERK phosphorylation and CCL26 expression. ERK inhibition (alone) similarly decreased IL-13-induced CCL26. Phosphorylated ERK expression was increased in NECs from CRSwNP subjects and positively correlated with both 15LO1 and CCL26 expression. CONCLUSIONS: 15LO1 expression is increased in NP epithelial cells and contributes to CCL26 expression through ERK activation. 15LO1 could be considered a novel therapeutic target for CRSwNP.

Targeted resequencing reveals genetic risks in patients with sporadic idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a genetic heterogeneous disease with high mortality and poor prognosis. However, a large fraction of genetic cause remains unexplained, especially in sporadic IPF (∼80% IPF). By systemically reviewing related literature and potential pathogenic pathways, 92 potentially IPF-related genes were selected and sequenced in genomic DNAs from 253 sporadic IPF patients and 125 matched health controls using targeted massively parallel next-generation sequencing. The identified risk variants were confirmed by Sanger sequencing. We identified two pathogenic and 10 loss-of-function (LOF) candidate variants, accounting for 4.74% (12 out of 253) of all the IPF cases. In burden tests, rare missense variants in three genes (CSF3R, DSP, and LAMA3) were identified that have a statistically significant relationship with IPF. Four common SNPs (rs3737002, rs2296160, rs1800470, and rs35705950) were observed to be statistically associated with increased risk of IPF. In the cumulative risk model, high risk subjects had 3.47-fold (95%CI: 2.07-5.81, P = 2.34 × 10-6 ) risk of developing IPF compared with low risk subjects. We drafted a comprehensive map of genetic risks (including both rare and common candidate variants) in patients with IPF, which could provide insights to help in understanding mechanisms, providing genetic diagnosis, and predicting risk for IPF.

Role of C/EBP homologous protein and endoplasmic reticulum stress in asthma exacerbation by regulating the IL-4/signal transducer and activator of transcription 6/transcription factor EC/IL-4 receptor α positive feedback loop in M2 macrophages.

BACKGROUND: C/EBP homologous protein (Chop), a marker of endoplasmic reticulum (ER) stress, exhibits aberrant expression patterns during asthma development. However, its exact role in asthma pathogenesis is not fully understood. OBJECTIVES: We aimed to determine the function and mechanism of Chop in the pathogenesis of allergic asthma in patients and animals. METHODS: Studies were conducted in asthmatic patients and Chop-/- mice to dissect the role of Chop and ER stress in asthma pathogenesis. An ovalbumin (OVA)-induced allergic airway inflammation model was used to address the effect of Chop deficiency on asthma development. Next, the effect of Chop deficiency on macrophage polarization and related signaling pathways was investigated to demonstrate the underlying mechanisms. RESULTS: Asthmatic patients and mice after OVA induction exhibited aberrant Chop expression along with ER stress. Specifically, Chop was noted to be specifically overexpressed in macrophages, and mice deficient in Chop were protected from OVA-induced allergic airway inflammation, as manifested by attenuated airway inflammation, remodeling, and hyperresponsiveness. Chop was found to exacerbate allergic airway inflammation by enhancing M2 programming in macrophages. Mechanistic studies characterized an IL-4/signal transducer and activator of transcription 6/transcription factor EC (Tfec)/IL-4 receptor α positive feedback regulatory loop, in which IL-4 induces Chop expression, which then promotes signal transducer and activator of transcription 6 signaling to transcribe Tfec expression. Finally, Tfec transcribes IL-4 receptor α expression to promote M2 programming in macrophages. CONCLUSIONS: Chop and ER stress are implicated in asthma pathogenesis, which involves regulation of M2 programming in macrophages.

Decreased concentration of IL-35 in plasma of patients with asthma and COPD.

BACKGROUND: IL-35 has been found to be involved in many inflammatory diseases in humans but its role in asthma and chronic obstructive pulmonary disease (COPD) is not clear. The plasma level of IL-35 in patients with asthma and COPD needs to be measured. OBJECTIVE: The aim of this study was to examine the plasma concentrations of IL-35 in newly diagnosed asthmatic and COPD patients and control subjects and investigate correlations of lung function, age, sex, smoking history with the levels of IL-35 in plasma in these diseases. METHODS: Blood samples were collected from patients with newly diagnosed asthma (44, 12 males, aged 33.75?8.94), newly diagnosed COPD (36, 36 males, aged 68.03 ± 8.94), and healthy control groups (23, 9 males, aged 30.06 ± 7.50). We determined the IL-35 levels in plasma by enzyme-linked immunosorbent assay. RESULT: The median and the range of values for IL-35 were 118.55 pg/ml (range 74.43~1767.22 pg/ml) in patients with asthma, 136.09 pg/ml (range 62.54~697.49 pg/ml) in patients with COPD and 275.86 pg/ml (range 26.11~1766.20 pg/ml) in control subjects. The levels of IL-35 in plasma showed a positive correlation with FEV1% and FVC% in asthmatic patients whose plasma IL-35 values were over 150 pg/ml. A positive correlation was also found between plasma IL-35 and FVC% in COPD patients whose plasma IL-35 values were over 150 pg/ml. CONCLUSIONS: These findings suggest that IL-35 may very probably be involved in the Th2 and Th17 mediated inflammation process of asthma and COPD. Its role in the mechanisms of COPD and asthma in human beings, as well as its therapeutic value in these diseases, need further investigation.

Compartmentalized mitochondrial ferroptosis converges with optineurin-mediated mitophagy to impact airway epithelial cell phenotypes and asthma outcomes.

A stable mitochondrial pool is crucial for healthy cell function and survival. Altered redox biology can adversely affect mitochondria through induction of a variety of cell death and survival pathways, yet the understanding of mitochondria and their dysfunction in primary human cells and in specific disease states, including asthma, is modest. Ferroptosis is traditionally considered an iron dependent, hydroperoxy-phospholipid executed process, which induces cytosolic and mitochondrial damage to drive programmed cell death. However, in this report we identify a lipoxygenase orchestrated, compartmentally-targeted ferroptosis-associated peroxidation process which occurs in a subpopulation of dysfunctional mitochondria, without promoting cell death. Rather, this mitochondrial peroxidation process tightly couples with PTEN-induced kinase (PINK)-1(PINK1)-Parkin-Optineurin mediated mitophagy in an effort to preserve the pool of functional mitochondria and prevent cell death. These combined peroxidation processes lead to altered epithelial cell phenotypes and loss of ciliated cells which associate with worsened asthma severity. Ferroptosis-targeted interventions of this process could preserve healthy mitochondria, reverse cell phenotypic changes and improve disease outcomes.

A nomogram for predicting echocardiogram prescription in outpatients: an analysis of the NAMCS database.

Background and objective: Cardiovascular disease is the leading cause of morbidity and mortality globally. Echocardiography is a commonly used method for assessing the condition of patients with cardiovascular disease. However, little is known about the population characteristics of patients who are recommended for echocardiographic examinations. Methods: The National Ambulatory Medical Care Survey was a cross-sectional survey previously undertaken in the USA. In this study, publicly accessible data from the National Ambulatory Medical Care Survey database (for 2007-2016 and 2018-2019; data for 2017 was not published) were utilized to create a nomogram based on significant risk predictors. The study was performed in accordance with the relevant guidelines and regulations stipulated in the National Ambulatory Medical Care Survey database. Patients were randomly assigned to one of two groups: training cohort or validation cohort. The latter was used to assess the reliability of the prediction nomogram. Decision curve analysis was performed to evaluate the net benefit. Propensity score matching analysis was used to evaluate the relevance of echocardiography to clinical decision-making. Results: A total of 217,178 outpatients were enrolled. Multivariable logistic regression analysis demonstrated that hypertension, hyperlipidemia, coronary artery disease/ischemic heart disease/history of myocardial infarction, congestive heart failure, major reason for visit, metropolitan statistical area, cerebrovascular disease/history of stroke or transient ischemic attack, previously assessed, insurance, referred, diagnosis, and reason for visit were all predictors of echocardiogram prescription in outpatients. The reliability of the predictive nomogram was confirmed in the validation cohort. After propensity score matching, there was a significant difference in new cardiovascular agent prescriptions between the echocardiogram and no echocardiogram groups (P < 0.01). Conclusion: In this cohort study, a nomogram based on the characteristics of outpatients was developed to predict the possibility of prescribing echocardiography. The echocardiogram group was more likely to be prescribed new cardiovascular agents. These findings may contribute to providing information about the gap between actual utilizations and guidelines and the actual outpatient practice, as well as meeting the needs of outpatients.

Tartrate-resistant acid phosphatase 5 promotes pulmonary fibrosis by modulating ß-catenin signaling.

Idiopathic pulmonary fibrosis (IPF) is a fatal interstitial lung disease with limited therapeutic options. Tartrate-resistant acid phosphatase 5 (ACP5) performs a variety of functions. However, its role in IPF remains unclear. Here, we demonstrate that the levels of ACP5 are increased in IPF patient samples and mice with bleomycin (BLM)-induced pulmonary fibrosis. In particular, higher levels of ACP5 are present in the sera of IPF patients with a diffusing capacity of the lungs for carbonmonoxide (DLCO) less than 40% of the predicted value. Additionally, Acp5 deficiency protects mice from BLM-induced lung injury and fibrosis coupled with a significant reduction of fibroblast differentiation and proliferation. Mechanistic studies reveal that Acp5 is upregulated by transforming growth factor-ß1 (TGF-ß1) in a TGF-ß receptor 1 (TGFßR1)/Smad family member 3 (Smad3)-dependent manner, after which Acp5 dephosphorylates p-ß-catenin at serine 33 and threonine 41, inhibiting the degradation of ß-catenin and subsequently enhancing ß-catenin signaling in the nucleus, which promotes the differentiation, proliferation and migration of fibroblast. More importantly, the treatment of mice with Acp5 siRNA-loaded liposomes or Acp5 inhibitor reverses established lung fibrosis. In conclusions, Acp5 is involved in the initiation and progression of pulmonary fibrosis and strategies aimed at silencing or suppressing Acp5 could be considered as potential therapeutic approaches against pulmonary fibrosis.

15LO1 dictates glutathione redox changes in asthmatic airway epithelium to worsen type 2 inflammation.

Altered redox biology challenges all cells, with compensatory responses often determining a cell's fate. When 15 lipoxygenase 1 (15LO1), a lipid-peroxidizing enzyme abundant in asthmatic human airway epithelial cells (HAECs), binds phosphatidylethanolamine-binding protein 1 (PEBP1), hydroperoxy-phospholipids, which drive ferroptotic cell death, are generated. Peroxidases, including glutathione peroxidase 4 (GPX4), metabolize hydroperoxy-phospholipids to hydroxy derivatives to prevent ferroptotic death, but consume reduced glutathione (GSH). The cystine transporter SLC7A11 critically restores/maintains intracellular GSH. We hypothesized that high 15LO1, PEBP1, and GPX4 activity drives abnormal asthmatic redox biology, evidenced by lower bronchoalveolar lavage (BAL) fluid and intraepithelial cell GSH:oxidized GSH (GSSG) ratios, to enhance type 2 (T2) inflammatory responses. GSH, GSSG (enzymatic assays), 15LO1, GPX4, SLC7A11, and T2 biomarkers (Western blot and RNA-Seq) were measured in asthmatic and healthy control (HC) cells and fluids, with siRNA knockdown as appropriate. GSSG was higher and GSH:GSSG lower in asthmatic compared with HC BAL fluid, while intracellular GSH was lower in asthma. In vitro, a T2 cytokine (IL-13) induced 15LO1 generation of hydroperoxy-phospholipids, which lowered intracellular GSH and increased extracellular GSSG. Lowering GSH further by inhibiting SLC7A11 enhanced T2 inflammatory protein expression and ferroptosis. Ex vivo, redox imbalances corresponded to 15LO1 and SLC7A11 expression, T2 biomarkers, and worsened clinical outcomes. Thus, 15LO1 pathway-induced redox biology perturbations worsen T2 inflammation and asthma control, supporting 15LO1 as a therapeutic target.

Residual filling material in dentinal tubules after gutta-percha removal observed with scanning electron microscopy.

INTRODUCTION: In cases of failed root canal treatment, endodontic retreatment of the root canal system is necessary. The present study aimed to assess variation in the incidence and depth of residual filling material in dentinal tubules after gutta-percha removal with H-files, the ProTaper Universal System (Dentsply Maillefer, Ballaigues, Switzerland), and the SybronEndo K3 System (SybronEndo Corporation, Orange, CA). METHODS: Forty human mandibular premolars with single straight root canals were prepared with K-files (up to size 40) using the step-back technique and filled by cold lateral condensation with gutta-percha and AH Plus sealers (Dentsply DeTrey, Konstanz, Germany). After 1 year, the 40 teeth were divided into one control group and 3 retreatment groups (n = 10 each). Gutta-percha was removed using H-files, the ProTaper Universal System, or the SybronEndo K3 System. The teeth were sectioned, and the incidence and depth of residual filling material in the dentinal tubules were measured under scanning electron microscopy. RESULTS: The depth of filling material in the dentinal tubules did not differ significantly among groups (P > .05). Residual filling material was present in significantly more dentinal tubules in the ProTaper (P = .043) and K3 groups (P = .001) than in the H-file and control groups. CONCLUSIONS: The ProTaper Universal System and the SybronEndo K3 System left filling material in a greater proportion of dentinal tubules than did H-files.