Acute Amelioration of Inflammatory Activity Caused by Endothelin-2 Deficiency during Acute Lung Injury.

In acute lung injury (ALI), a severe insult induces a hyperinflammatory state in the lungs. The mortality rate of severe ALI remains high, and novel mechanistic insights are required to improve therapeutic strategies. Endothelin-2 (Edn2), the least studied isoform of endothelin, is involved in lung physiology and development and can be affected by various factors. One of them is inflammation, and another isoform of endothelin, endothelin-1 (Edn1), affects lung inflammatory responses. Considering the importance of Edn2 in the lungs and how Edn2 works through the same receptors as Edn1, we postulated that Edn2 may affect inflammatory responses that are central to ALI pathophysiology. In this study, we performed 24 hours intratracheal lipopolysaccharide (LPS) instillation or PBS control as an in vivo ALI model in eight-week-old conditional Edn2 knockout mice (Edn2-iKO), with Edn2-floxed mice as controls. Bronchoalveolar lavage (BAL) fluid and tissue were collected after exsanguination and analyzed for its cellular, molecular, functional, and histological inflammatory phenotypes. We found that Edn2-iKO mice displayed a reduced pro-neutrophilic inflammatory phenotype even after acute LPS treatment, shown by the reduction in the overall protein concentration and neutrophil count in bronchoalveolar lavage fluids. Further investigation revealed a reduction in mRNA interferon gamma (IFNγ) level of Edn2-iKO lungs and suppression of its downstream signaling, including phosphorylated level of STAT1 and IL-1ß secretion, leading to reduced NFĸB activation. To conclude, Edn2 deletion suppressed acute lung inflammation by reducing neutrophil-mediated IFNγ/STAT1/IL-1ß/NFĸB signaling cascade. Targeting Edn2 signaling may be beneficial for the development of novel treatment options for ALI.

Increased serum activin A level in congenital heart disease-associated pulmonary artery hypertension: A comparative study from the COHARD-PH registry.

Activin A, a member of TGF-ß superfamily, has been implicated in the pathogenesis of pulmonary artery hypertension (PAH). PAH due to congenital heart disease (CHD-PAH) is a major problem in developing countries. Activin A may have a role in PAH development and progression among uncorrected CHD. In this comparative study, serum activin A level was significantly increased in subjects with uncorrected CHD without the presence of PH and were more significantly risen in CHD-PAH, as compared to control. The utilization of serum activin A measurement seems promising to identify uncorrected CHD patients with PAH development and progression.

Single-cell transcriptomics of human cholesteatoma identifies an activin A-producing osteoclastogenic fibroblast subset inducing bone destruction.

Cholesteatoma, which potentially results from tympanic membrane retraction, is characterized by intractable local bone erosion and subsequent hearing loss and brain abscess formation. However, the pathophysiological mechanisms underlying bone destruction remain elusive. Here, we performed a single-cell RNA sequencing analysis on human cholesteatoma samples and identify a pathogenic fibroblast subset characterized by abundant expression of inhibin ßA. We demonstrate that activin A, a homodimer of inhibin ßA, promotes osteoclast differentiation. Furthermore, the deletion of inhibin ßA /activin A in these fibroblasts results in decreased osteoclast differentiation in a murine model of cholesteatoma. Moreover, follistatin, an antagonist of activin A, reduces osteoclastogenesis and resultant bone erosion in cholesteatoma. Collectively, these findings indicate that unique activin A-producing fibroblasts present in human cholesteatoma tissues are accountable for bone destruction via the induction of local osteoclastogenesis, suggesting a potential therapeutic target.

An electrocardiographic score to predict pulmonary hypertension in children with atrial septal defect.

BACKGROUND: In limited resource settings, identification of factors that predict the occurrence of pulmonary hypertension(PH) in children with atrial septal defect(ASD) is important to decide which patients should be prioritized for defect closure to prevent complication. Echocardiography and cardiac catheterization are not widely available in such settings. No scoring system has been proposed to predict PH among children with ASD. We aimed to develop a PH prediction score using electrocardiography parameters for children with ASD in Indonesia. METHODS: A cross-sectional study reviewing medical record including ECG record was conducted among all children with newly diagnosed isolated ASD admitted to Dr Sardjito Hospital in Yogyakarta, Indonesia during 2016-2018. Diagnosis of ASD and PH was confirmed through echocardiography and/or cardiac catheterization. Spiegelhalter Knill-Jones approach was used to develop PH prediction score. Accuracy of prediction score was performed using a receiver operating characteristic (ROC) curve. RESULTS: Of 144 children, 50(34.7%) had PH. Predictors of pulmonary hypertension were QRS axis ≥120°, P wave ≥ 3 mm at lead II, R without S at V1, Q wave at V1, right bundle branch block (RBBB), R wave at V1, V2 or aVR > normal limit and S wave at V6 or lead I > normal limit. ROC curve from prediction scores yielded an area under the curve (AUC) 0.908(95% CI 0.85-0.96). Using the cut-off value 3.5, this PH prediction score had sensitivity of 76%(61.8-86.9), specificity 96.8%(91.0-99.3), positive predictive value 92.7%(80.5-97.5), negative predictive value 88.4%(82.2-92.6), and positive likelihood ratio 23.8(7.7-73.3). CONCLUSIONS: A presence of PH in children with ASD can be predicted by the simple electrocardiographic score including QRS axis ≥120°, P wave ≥3 mm at lead II, R without S at V1, Q wave at V1, RBBB, R wave at V1, V2 or aVR > normal limit and S wave at V6 or lead I > normal limit. A total score ≥ 3.5 shows a moderate sensitivity and high specificity to predict PH among children with ASD.

Endothelial cell senescence exacerbates pulmonary hypertension by inducing juxtacrine Notch signaling in smooth muscle cells.

Pulmonary arterial hypertension (PAH) is a fatal disease characterized by a progressive increase in pulmonary artery pressure caused by pathological pulmonary artery remodeling. Here, we demonstrate that endothelial cell (EC) senescence plays a negative role in pulmonary hypertension via juxtacrine interaction with smooth muscle cells (SMCs). By using EC-specific progeroid mice, we discovered that EC progeria deteriorated vascular remodeling in the lungs, and exacerbated pulmonary hypertension in mice. Mechanistically, senescent ECs overexpressed Notch ligands, which resulted in increased Notch signaling and activated proliferation and migration capacities in neighboring SMCs. Pharmacological inhibition of Notch signaling reduced the effects of senescent ECs on SMCs functions in vitro, and improved the worsened pulmonary hypertension in EC-specific progeroid mice in vivo. Our findings show that EC senescence is a critical disease-modifying factor in PAH and that EC-mediated Notch signaling is a pharmacotherapeutic target for the treatment of PAH, particularly in the elderly.

Efficacy and Safety of Balloon Pulmonary Angioplasty for Patients With Chronic Thromboembolic Pulmonary Hypertension and Comorbid Chronic Obstructive Pulmonary Disease.

Background Balloon pulmonary angioplasty (BPA) is a promising treatment modality for nonoperable chronic thromboembolic pulmonary hypertension (CTEPH). However, BPA for atypical CTEPH with concurrent chronic obstructive pulmonary disease (COPD) remains controversial owing to the risk of exacerbation of ventilation-perfusion mismatch. We aimed to evaluate the efficacy and safety of BPA for CTEPH with moderate or severe COPD. Methods and Results Data from 149 patients with CTEPH, who underwent BPA from March 2011 to June 2021, were retrospectively analyzed. Patients were divided based on COPD comorbidity: the COPD group (n=32, defined as forced expiratory volume in 1 second/forced vital capacity <70% and forced expiratory volume in 1 second <80% predicted) and the non-COPD group (n=101); patients with mild COPD (n=16) were excluded. Hemodynamic and respiratory parameters were compared between the groups. Hemodynamics improved similarly in both groups (reduction in pulmonary vascular resistance): -55.6±29.0% (COPD group) and -58.9±21.4% (non-COPD group); P=nonsignificant. Respiratory function and oxygenation improved in the COPD group (forced expiratory volume in 1 second/forced vital capacity [61.8±7.0% to 66.5±10.2%, P=0.02] and arterial oxygen partial pressure [60.9±10.6 mm Hg to 69.3±13.6 mm Hg, P<0.01]). Higher vital capacity (P=0.024) and higher diffusing capacity for lung carbon monoxide (P=0.028) at baseline were associated with greater improvement in oxygenation in the multivariable linear analysis. Lung injury per BPA session was 1.6% in the COPD group. Conclusions The efficacy and safety of BPA for nonoperable CTEPH in patients with comorbid COPD were similar to those in patients without COPD. Oxygenation and forced expiratory volume in 1 second/forced vital capacity improved in patients with COPD. BPA should be considered in patients with CTEPH with concurrent COPD.

Combination of echocardiography and pulmonary function tests could predict no complication of pulmonary hypertension during 5 years in patients with systemic sclerosis.

OBJECTIVE: To determine whether complications of pulmonary hypertension (PH) can be predicted by noninvasive screening tests in systemic sclerosis (SSc). METHODS: Forty-seven of 113 SSc patients underwent right heart catheterization (RHC) during 2011-2014. Clinical data, hemodynamic features, echocardiography, and pulmonary function tests had been followed up from the first RHC until 5 years later. RESULTS: At the first RHC, out of 44 patients, 8 were diagnosed with pre-capillary PH (mean pulmonary arterial pressure [mPAP] > 20 mm Hg), and 36 patients were defined as no-PH (mPAP ≤ 20 mm Hg). Three patients with >15 mm Hg of pulmonary artery wedge pressure were excluded. Receiver operating characteristic analyses for pre-capillary PH using estimated systolic PAP (esPAP) revealed an area under the curve (AUC) of 0.736, with a sensitivity and specificity of 62.5% and 86.1%, respectively, at a cutoff level of 35.0 mm Hg. The predicted percentage diffusing lung capacity for carbon monoxide (DLCO%) revealed an AUC of 0.840, with a sensitivity and specificity of 85.7% and 80.0%, respectively, at a cutoff level of 70.0%. Six pre-capillary PH patients, including one who died from PH 14 months after the first RHC, indicated exacerbations of mPAP or esPAP within 5 years. When esPAP < 35.0 mm Hg and DLCO% > 70% were met as the cutoff, none had been newly diagnosed with PH over 5 years. CONCLUSIONS: The conventional screening tests may be useful for detecting pre-capillary PH with SSc, and both esPAP < 35.0 mm Hg and DLCO% > 70% indicated a lower risk of developing PH for at least 5 years.

Inactivating the Uninhibited: The Tale of Activins and Inhibins in Pulmonary Arterial Hypertension.

Advances in technology and biomedical knowledge have led to the effective diagnosis and treatment of an increasing number of rare diseases. Pulmonary arterial hypertension (PAH) is a rare disorder of the pulmonary vasculature that is associated with high mortality and morbidity rates. Although significant progress has been made in understanding PAH and its diagnosis and treatment, numerous unanswered questions remain regarding pulmonary vascular remodeling, a major factor contributing to the increase in pulmonary arterial pressure. Here, we discuss the role of activins and inhibins, both of which belong to the TGF-ß superfamily, in PAH development. We examine how these relate to signaling pathways implicated in PAH pathogenesis. Furthermore, we discuss how activin/inhibin-targeting drugs, particularly sotatercep, affect pathophysiology, as these target the afore-mentioned specific pathway. We highlight activin/inhibin signaling as a critical mediator of PAH development that is to be targeted for therapeutic gain, potentially improving patient outcomes in the future.

In vivo induction of activin A-producing alveolar macrophages supports the progression of lung cell carcinoma.

Alveolar macrophages (AMs) are crucial for maintaining normal lung function. They are abundant in lung cancer tissues, but their pathophysiological significance remains unknown. Here we show, using an orthotopic murine lung cancer model and human carcinoma samples, that AMs support cancer cell proliferation and thus contribute to unfavourable outcome. Inhibin beta A (INHBA) expression is upregulated in AMs under tumor-bearing conditions, leading to the secretion of activin A, a homodimer of INHBA. Accordingly, follistatin, an antagonist of activin A is able to inhibit lung cancer cell proliferation. Single-cell RNA sequence analysis identifies a characteristic subset of AMs specifically induced in the tumor environment that are abundant in INHBA, and distinct from INHBA-expressing AMs in normal lungs. Moreover, postnatal deletion of INHBA/activin A could limit tumor growth in experimental models. Collectively, our findings demonstrate the critical pathological role of activin A-producing AMs in tumorigenesis, and provides means to clearly distinguish them from their healthy counterparts.

Gliovascular interface abnormality in mice with endothelial cell senescence.

In the brain, neurons, glial cells, vascular endothelial cells (ECs), and mural cells form a functional structure referred to as the neurovascular unit (NVU). The functions of the NVU become impaired with aging. To gain insight into the mechanism underlying the aging-related changes in the NVU, we characterized in the present study the gliovascular interface in transgenic mice expressing a dominant-negative form of the telomeric repeat-binding factor 2 (TERF2) specifically in ECs using the Tie2 promoter. In these transgenic mice, senescence occurred in the cerebral ECs and was accompanied by upregulation of the mRNAs of proinflammatory cell adhesion molecules and cytokines. It is noteworthy that in the deep layers of the cerebral cortex, astrocytes exhibited an increase in the signals for S100ß as well as a decrease in the polarization of the water channel aquaporin-4 (AQP4) to the perivascular endfeet of the astrocytes. Mechanistically, the perivascular localization of dystroglycan and its ligand, laminin α2, was decreased, and their localization correlated well with the perivascular localization of AQP4, which supports the notion that their interaction regulates the perivascular localization of AQP4. The diminished perivascular localization of laminin α2 may be attributed to its proteolytic degradation by the matrix metalloproteinase-2 released by senescent ECs. Pericyte coverage was increased and negatively correlated with the decrease in the perivascular localization of AQP4. We propose that aging-related changes in ECs induce a mild morphological alteration of astrocytes and affect the localization of AQP4 at the gliovascular interface.

Microvasculopathy Evaluated by Dual-Energy Computed Tomography in Patients with Chronic Thromboembolic Pulmonary Hypertension and Pulmonary Arterial Hypertension.

Background: Poor subpleural perfusion (PSP) on dual-energy computed tomography (DE-CT) suggests microvasculopathy in chronic thromboembolic pulmonary hypertension (CTEPH). However, whether the microvasculopathy findings are equivalent to those in pulmonary arterial hypertension (PAH) remains unclear. The aim of this study was to elucidate the characteristics of microvasculopathy in CTEPH compared to those of that in PAH. Methods: We retrospectively reviewed subpleural perfusion on DE-CT and the hemodynamics of 23 patients with PAH and 113 with inoperable CTEPH. Subpleural perfusion on DE-CT was classified as poor (subpleural spaces in all segments with little or no perfusion) or normal. Results: PSP was observed in 51% of patients with CTEPH and in 4% of those with PAH (p < 0.01). CTEPH patients with PSP had poorer baseline hemodynamics and lower diffusing capacity for carbon monoxide divided by the alveolar volume (DLCO/VA) than those with CTEPH with normal perfusion (pulmonary vascular resistance [PVR]: 768 ± 445 dynes-sec/cm5 vs. 463 ± 284 dynes-sec/cm5, p < 0.01; DLCO/VA, 60.4 ± 16.8% vs. 75.9 ± 15.7%, p < 0.001). Despite the existence of PSP, hemodynamics improved to nearly normal in both groups after balloon pulmonary angioplasty. Conclusions: PSP on DE-CT, which is one of the specific imaging findings in CTEPH, might suggest a different mechanism of microvasculopathy from that in PAH.

The loss of endothelin-2 exhibits an anticancer effect in A549 human lung adenocarcinoma cell line.

Lung cancer is the leading cause of cancer-related deaths worldwide, and adenocarcinoma is the most common subtype of lung cancer. Endothelin-2 (ET-2) is expressed in the epithelium of alveoli, and its expression is increased in cancer. However, the role of ET-2 in lung adenocarcinoma remains unclear. This study aimed to investigate the pathophysiological functions of ET-2 in A549 human lung adenocarcinoma cells. We analyzed the expression of ET-2 mRNA in lung adenocarcinoma tissues compared with that in nontumor lung tissues using public online databases. The function of ET-2 in A549 cells was investigated using siRNA. ET-2 mRNA level was upregulated in lung adenocarcinoma tissues, and high ET-2 level was associated with poor overall survival in patients with lung adenocarcinoma. ET-2 silencing reduced the proliferation, migration, and invasion, and enhanced apoptosis in A549 cells. Mechanistically, ET-2 silencing reduced the expression levels of X-linked inhibitor of apoptosis and survivin, which are members of the inhibitor apoptosis protein family. In addition, silencing ET-2 inhibited epithelial-mesenchymal transition, which halted migration. Therefore, the specific targeting of ET-2 may be a potential treatment strategy for lung adenocarcinoma.

Budesonide/glycopyrronium/formoterol fumarate triple therapy prevents pulmonary hypertension in a COPD mouse model via NFκB inactivation.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a health problem that results in death, commonly due to the development of pulmonary hypertension (PH). Here, by utilizing a mouse model of intratracheal elastase-induced emphysema that presents three different phases of COPD, we sought to observe whether budesonide/glycopyrronium/formoterol fumarate (BGF) triple therapy could prevent COPD-PH in addition to ameliorating COPD progression. METHODS: We utilized intratracheal elastase-induced emphysema mouse model and performed experiments in three phases illustrating COPD progression: inflammatory (1 day post-elastase), emphysema (3 weeks post-elastase) and PH (4 weeks post-elastase), while treatments of BGF and controls (vehicle, one-drug, and two-drug combinations) were started in prior to elastase instillation (inflammatory phase), at day 7 (emphysema), or at day 14 (PH phase). Phenotype analyses were performed in each phase. In vitro, A549 cells or isolated mouse lung endothelial cells (MLEC) were treated with TNFα with/without BGF treatment to analyze NFκB signaling and cytokine expression changes. RESULTS: We observed significant reductions in the proinflammatory phenotype observed in the lungs and bronchoalveolar lavage fluid (BALF) 1 day after elastase administration in mice treated with BGF compared with that in mice administered elastase alone (BALF neutrophil percentage, p = 0.0011 for PBS/Vehicle vs. PBS/Elastase, p = 0.0161 for PBS/Elastase vs. BGF). In contrast, only BGF treatment significantly ameliorated the elastase-induced emphysematous lung structure and desaturation after three weeks of elastase instillation (mean linear intercept, p = 0.0156 for PBS/Vehicle vs. PBS/Elastase, p = 0.0274 for PBS/Elastase vs. BGF). Furthermore, BGF treatment prevented COPD-PH development, as shown by improvements in the hemodynamic and histological phenotypes four weeks after elastase treatment (right ventricular systolic pressure, p = 0.0062 for PBS/Vehicle vs. PBS/Elastase, p = 0.027 for PBS/Elastase vs. BGF). Molecularly, BGF acts by inhibiting NFκB-p65 phosphorylation and subsequently decreasing the mRNA expression of proinflammatory cytokines in both alveolar epithelial and pulmonary endothelial cells. CONCLUSION: Our results collectively showed that BGF treatment could prevent PH in addition to ameliorating COPD progression via the inhibition of inflammatory NFκB signaling.

Endothelin and the Cardiovascular System: The Long Journey and Where We Are Going.

Endothelin was first discovered more than 30 years ago as a potent vasoconstrictor. In subsequent years, three isoforms, two canonical receptors, and two converting enzymes were identified, and their basic functions were elucidated by numerous preclinical and clinical studies. Over the years, the endothelin system has been found to be critical in the pathogenesis of several cardiovascular diseases, including hypertension, pulmonary arterial hypertension, heart failure, and coronary artery disease. In this review, we summarize the current knowledge on endothelin and its role in cardiovascular diseases. Furthermore, we discuss how endothelin-targeting therapies, such as endothelin receptor antagonists, have been employed to treat cardiovascular diseases with varying degrees of success. Lastly, we provide a glimpse of what could be in store for endothelin-targeting treatment options for cardiovascular diseases in the future.

RC time (resistance × compliance) is related to residual symptom after pulmonary endarterectomy in chronic thromboembolic pulmonary hypertension.

Background: Right ventricular (RV) afterload is widely assessed by pulmonary vascular resistance (PVR). However, RV afterload is underestimated because PVR does not account for the pulsatile load. The pulsatile load is often evaluated by pulmonary arterial compliance (PAC). The RC (resistance-compliance) time, which is calculated from the product of PVR and PAC, is considered to remain constant under medical therapy. However, little is known on how RC time is affected by invasive therapy in chronic thromboembolic pulmonary hypertension (CTEPH). This study aimed to evaluate change of RC time in patients underwent pulmonary endarterectomy (PEA). Furthermore, we investigated the clinical relevance of RC time. Methods: We reviewed consecutive 50 patients except for death case underwent PEA. Baseline clinical parameters including RC time before performing PEA and follow-up were evaluated. Patients was classified as decrease or non-decrease according to change of RC time. Furthermore, we classified patients into a NYHA I group who had no symptom after treatment and a residual symptom group in order to investigate the relationship of RC time to residual symptoms. Results: RC time was significantly decreased after PEA (0.54 ± 0.16 to 0.45 ± 0.12 sec, p < 0.001). Residual symptom after PEA of Decrease group were significantly better than that of Non-decrease group in RC time (12 patients, 40% vs. 11 patients, 78.6%, p < 0.02). Furthermore, multivariate analysis revealed that only RC time after PEA was independently associated with residual symptom (OR 1.026, 95% CI 1.005-1.048; p = 0.017). Conclusions: RC time was decreased after PEA, and might be a possible indicator for predicting PEA success.

ChGn-2 Plays a Cardioprotective Role in Heart Failure Caused by Acute Pressure Overload.

Background Cardiac extracellular matrix is critically involved in cardiac homeostasis, and accumulation of chondroitin sulfate glycosaminoglycans (CS-GAGs) was previously shown to exacerbate heart failure by augmenting inflammation and fibrosis at the chronic phase. However, the mechanism by which CS-GAGs affect cardiac functions remains unclear, especially at the acute phase. Methods and Results We explored a role of CS-GAG in heart failure using mice with target deletion of ChGn-2 (chondroitin sulfate N-acetylgalactosaminyltransferase-2) that elongates CS chains of glycosaminoglycans. Heart failure was induced by transverse aortic constriction in mice. The role of CS-GAG derived from cardiac fibroblasts in cardiomyocyte death was analyzed. Cardiac fibroblasts were subjected to cyclic mechanical stretch that mimics increased workload in the heart. Significant CS-GAGs accumulation was detected in the heart of wild-type mice after transverse aortic constriction, which was substantially reduced in ChGn-2-/- mice. Loss of ChGn-2 deteriorated the cardiac dysfunction caused by pressure overload, accompanied by augmented cardiac hypertrophy and increased cardiomyocyte apoptosis. Cyclic mechanical stretch increased ChGn-2 expression and enhanced glycosaminoglycan production in cardiac fibroblasts. Conditioned medium derived from the stretched cardiac fibroblasts showed cardioprotective effects, which was abolished by CS-GAGs degradation. We found that CS-GAGs elicits cardioprotective effects via dual pathway; direct pathway through interaction with CD44, and indirect pathway through binding to and activating insulin-like growth factor-1. Conclusions Our data revealed the cardioprotective effects of CS-GAGs; therefore, CS-GAGs may play biphasic role in the development of heart failure; cardioprotective role at acute phase despite its possible unfavorable role in the advanced phase.

Usefulness of Combining NT-proBNP Level and Right Atrial Diameter for Simple and Early Noninvasive Detection of Pulmonary Hypertension Among Adult Patients with Atrial Septal Defect.

BACKGROUND: Atrial septal defect developed pulmonary hypertension (ASD-PH) at first diagnosis due to late presentation are common in Indonesia. Transthoracic echocardiogram (TTE) is a common tool to detect ASD-PH, before proceeding to invasive procedure. The NT-proBNP measurement to screen ASD-PH is not yet considered the standard approach, especially in limited resource conditions. The objective of this study is to assess the value of NT-proBNP, along with simple TTE parameter, to screen PH among adults with ASD. METHODS: This was a cross-sectional study. The subjects were adult ASD-PH patients from the COHARD-PH  registry (n=357). Right heart catheterization (RHC) was performed to diagnose PH. Blood sample was withdrawn during RHC for NT-proBNP measurement. The TTE was performed as standard procedure and its regular parameters were assessed, along with NT-proBNP, to detect PH. RESULTS: Two parameters significantly predicted PH, namely NT-proBNP and right atrial (RA) diameter. The cut-off of NT-proBNP to detect PH was ≥140 pg/mL. The cut-off of RA diameter to detect PH was ≥46.0 mm. The combined values of NT-proBNP level ≥140 pg/mL and RA diameter ≥46.0 mm yielded 46.6% sensitivity, 91.8% specificity, 54.3% accuracy, 96.5% positive predictive value and 26.2% negative predictive value to detect PH, which were better than single value. CONCLUSION: NT-proBNP level ≥140 pg/mL represented PH in adult ASD patients. The NT-proBNP level ≥140 pg/mL and RA diameter ≥46.0 mm had a pre-test probability measures to triage patients needing more invasive procedure and also to determine when and if to start the PH-specific treatment.

Protective Effects of Endothelin-2 Expressed in Epithelial Cells on Bleomycin-Induced Pulmonary Fibrosis in Mice.

Initially, endothelin (ET)-2 was described as an endothelium-derived vasoconstrictor. However, accumulating evidence suggests the involvement of ET-2 in non-cardiovascular physiology and disease pathophysiology. The deficiency of ET-2 in mice can be lethal, and such mice exhibit a distinct developmental abnormality in the lungs. Nonetheless, the definite role of ET-2 in the lungs remains unclear. The ET-2 isoform, ET-1, promotes pulmonary fibrosis in mice. Although endothelin receptor antagonists (ERAs) show improvements in bleomycin-induced pulmonary fibrosis in mouse models, clinical trials examining ERAs for pulmonary fibrosis treatment have been unsuccessful, even showing harmful effects in patients. We hypothesized that ET-2, which activates the same receptor as ET-1, plays a distinct role in pulmonary fibrosis. In this study, we showed that ET-2 is expressed in the lung epithelium, and ET-2 deletion in epithelial cells of mice results in the exacerbation of bleomycin-induced pulmonary fibrosis. ET-2 knockdown in lung epithelial cell lines resulted in increased apoptosis mediated via oxidative stress induction. In contrast to the effects of ET-1, which induced fibroblast activation, ET-2 hampered fibroblast activation in primary mouse lung fibroblast cells by inhibiting the TGF-ß-SMAD2/3 pathway. Our results demonstrated the divergent roles of ET-1 and ET-2 in pulmonary fibrosis pathophysiology and suggested that ET-2, expressed in epithelial cells, exerts protective effects against the development of pulmonary fibrosis in mice.

GPNMB plays a protective role against obesity-related metabolic disorders by reducing macrophage inflammatory capacity.

Obesity is a global health problem that is often related to cardiovascular and metabolic diseases. Chronic low-grade inflammation in white adipose tissue (WAT) is a hallmark of obesity. Previously, during a search for differentially expressed genes in WAT of obese mice, we identified glycoprotein nonmetastatic melanoma protein B (GPNMB), of which expression was robustly induced in pathologically expanded WAT. Here, we investigated the role of GPNMB in obesity-related metabolic disorders utilizing GPNMB-deficient mice. When fed a high-fat diet (HFD), GPNMB-deficient mice showed body weight and adiposity similar to those of wild-type (WT) mice. Nonetheless, insulin and glucose tolerance tests revealed significant obesity-related metabolic disorders in GPNMB-KO mice compared with WT mice fed with HFD. Chronic WAT inflammation was remarkably worsened in HFD-fed GPNMB-KO mice, accompanied by a striking increase in crown-like structures, typical hallmarks for diseased WAT. Macrophages isolated from GPNMB-KO mice were observed to produce more inflammatory cytokines than those of WT mice, a difference abolished by supplementation with recombinant soluble GPNMB extracellular domain. We demonstrated that GPNMB reduced the inflammatory capacity of macrophages by inhibiting NF-κB signaling largely through binding to CD44. Finally, we showed that macrophage depletion by addition of clodronate liposomes abolished the worsened WAT inflammation and abrogated the exacerbation of metabolic disorders in GPNMB-deficient mice fed on HFD. Our data reveal that GPNMB negatively regulates macrophage inflammatory capacities and ameliorates the WAT inflammation in obesity; therefore we conclude that GPNMB is a promising therapeutic target for the treatment of metabolic disorders associated with obesity.