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The integration of data from various healthcare centers into disease registries is pivotal for facilitating collaborative research and enhancing clinical insights. In this study, we investigate the integration process of existing registries into the PVRI GoDeep meta-registry, focusing on the complexities and challenges encountered. We detail the integration process, including data transformation, mapping updates, and feedback mechanisms. Our findings underscore the importance of standardized processes and proactive communication in addressing data quality issues, ultimately enhancing the reliability and trustworthiness of meta-registry data. Through careful harmonization of the data and transparent documentation of data processing, we pave the way for leveraging registry data to drive advancements in pulmonary hypertension research and patient care.

Aims: Hepatic T1-time derived from cardiac magnetic resonance imaging (cMRI) reflects venous congestion and may provide a simple alternative to invasive end-diastolic elastance (Eed) for assessment of right ventricular (RV) diastolic function. We investigated the association of native hepatic T1-time with single-beat Eed and the value of hepatic T1-time for longitudinal monitoring in pulmonary hypertension (PH)., Methods and Results: We retrospectively enrolled 85 patients with suspected PH (59% female; 78 with PH diagnosed; 7 with PH excluded) who underwent standard right heart catheterization and cMRI within 24 h between 2015 and 2020. Hepatic T1-time showed moderate to strong correlations (rho >0.3, P ≤ 0.002) with pulmonary vascular resistance, native myocardial T1-time, Eed, RV size and function, brain natriuretic peptide (BNP) level, and 6-min walk distance, and a significant association with functional class (Kruskal-Wallis P < 0.001). Eed, myocardial T1-time, and BNP were independently linked to hepatic T1-time in multivariable regression. Hepatic T1-time > 598 ms predicted elevated Eed with 72.9% sensitivity and 82.1% specificity. Hepatic T1-time was superior to Eed in predicting clinical worsening. In 16 patients with follow-up assessments, those with decreasing hepatic T1-time (7 patients) showed significant hemodynamic improvements, whereas those with increasing hepatic T1-time (9 patients) did not. In a second retrospective cohort of 27 patients with chronic thromboembolic PH undergoing balloon pulmonary angioplasty, hepatic T1-time decreased significantly and hemodynamics improved after the procedure., Conclusions: Hepatic T1-time predicts RV diastolic dysfunction and prognosis, and may be useful for monitoring disease progression and treatment response in PH., Competing Interests: Declaration of competing interest NK has received speaking fees from Janssen outside the submitted work. AY has received personal fees from MSD outside the submitted work. WS has received speaker/consultancy fees from Pfizer and Bayer Pharma AG. CBW has received speaker fees and/or consultant honoraria from Actelion, AOP Orphan Pharmaceuticals AG, Bayer AG, BTG, MSD, and Pfizer. KT has received speaking fees from Actelion, Janssen, and Bayer. All other authors report no relationships that could be construed as a conflict of interest., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

The PEGASUS study is the first multicentric and prospective assessment of the safety of air travel flying in pulmonary hypertension (PH) (NCT03051763). Data of air travel from 60 patients with PH was available. No severe adverse events occurred. Nine patients self-reported mild adverse events during flight (13%), while after landing, 12 patients reported events (20%). Solely one patient (2%) had an adverse event leading to medical consultation. In patients with PH and World Health Organization functional classes II and III, air travel was safe., Competing Interests: Henning Gall reports grants from the German Research Foundation and nonfinancial support from the University of Giessen during the conduct of the study, and personal fees from Actelion, AstraZeneca, Bayer, BMS, GSK, Janssen‐Cilag, Lilly, MSD, Novartis, OMT, Pfizer, and United Therapeutics outside the submitted work. Athiththan Yogeswaran reports non‐financialnonfinancial support from the University of Giessen during the conduct of the study. Natascha Sommer reports personal fees from Actelion outside the submitted work. Hossein A. Ghofrani reports grants from the German Research Foundation and nonfinancial support from the University of Giessen during the conduct of the study, and personal fees from Bayer, Actelion, Pfizer, Merck, GSK, and Takeda, grants and personal fees from Novartis, Bayer HealthCare, and Encysive/Pfizer, and grants from Aires, the German Research Foundation, Excellence Cluster Cardiopulmonary Research, and the German Ministry for Education and Research outside the submitted work. Werner Seeger reports grants from the German Research Foundation and nonfinancial support from the University of Giessen during the conduct of the study, and personal fees from Pfizer and Bayer Pharma AG outside the submitted work. Manuel J. Richter reports grants from the German Research Foundation and nonfinancial support from the University of Giessen during the conduct of the study, and grants from United Therapeutics, grants and personal fees from Bayer, and personal fees from Actelion, Mundipharma, Roche, and OMT outside the submitted work. Khodr Tello reports grants from the German Research Foundation and nonfinancial support from the University of Giessen during the conduct of the study, and personal fees from Actelion and Bayer outside the submitted work. Heinrike Wilkens received fees for lectures and/or consultations from Actelion, AOP, Bayer, Biotest, Boehringer‐Ingelheim, Daiichi Sankyo, Ferrer, GSK, Janssen Cilag, and MSD outside the submitted work. Michael Halank reports personal fees from AstraZeneca, Janssen‐Cilag, and MSD outside the submitted work. Melanie Heberling reports personal fees from Janssen‐Cilag und MSD outside the submitted work. Dr. Ulrich receives research grants from the Swiss National Science Foundation, Zurich and Swiss Lung League, Orpha‐Swiss, Emdo Foundation and travel support, lecture fees, and advisory compensation from MSD SA, Orpha Swiss, Janssen SA, Novartis SA, all unrelated to the present work. Katrin Milger reports speaker and/or advisory board honoraria from AOP Pharma, Ferrer, Janssen, MSD. Tobias J. Lange reports personal fees from Acceleron Pharma, AstraZeneca, Bayer, Böhringer Ingelheim, Ferrer, Gossamer Bio, Janssen Cilag, MSD, Orphacare, and Pfizer. Stefan Stadler reports personal fees from Acceleron Pharma, AOP Health, Gossamer Bio, Janssen Cilag, MSD, and Pfizer. Jan C. Kamp is supported by PRACTIS—Clinician Scientist Program of Hannover Medical School, funded by the German Research Foundation, grant no. ME 3696/3‐1, KFO311— 286251789. Ekkehard Grünig has received fees for lectures and/or consultations from Actelion, Bayer/MSD, Ferrer, GEBRO, GSK, Janssen, and OMT. Research grants to his institution have been received from Acceleron, Actelion, BayerHealthCare, MSD, Bellerophon, GossamerBio, GSK, Janssen, Novartis, OMT, Pfizer, REATE, and United Therapeutics outside the submitted work. Satenik Harutynova has received support from Janssen, OMT, Bayer Pharma, GSK and speaker fees from Janssen and OMT outside submitted work. Karen Olsson has received fees for lectures and/or consultations from Acceleron, Actelion, AOP, MSD, Ferrer, Janssen, and OMT. Research grants to her institution have been received from Actelion, all outside the submitted work. All other authors declare no conflicts of interest., (© 2024 The Author(s). Pulmonary Circulation published by John Wiley & Sons Ltd on behalf of Pulmonary Vascular Research Institute.)

Background: To reduce smoking uptake in adolescents, the medical students' network Education Against Tobacco (EAT) has developed a school-based intervention involving a face-aging mobile app (Smokerface)., Methods: A two-arm cluster-randomized controlled trial was conducted, evaluating the 2016 EAT intervention, which employed the mobile app Smokerface and which was delivered by medical students. Schools were randomized to intervention or control group. Surveys were conducted at baseline (pre-intervention) and at 9, 16, and 24 months post-intervention via paper & pencil questionnaires. The primary outcome was the difference in within-group changes in smoking prevalence between intervention and control group at 24 months., Results: Overall, 144 German secondary schools comprising 11,286 pupils participated in the baseline survey, of which 100 schools participated in the baseline and at least one of the follow-up surveys, yielding 7437 pupils in the analysis sample. After 24 months, smoking prevalence was numerically lower in the intervention group compared to control group (12.9 % vs. 14.3 %); however, between-group differences in change in smoking prevalence between baseline and 24-months follow-up (OR=0.83, 95 %-CI: 0.64-1.09) were not statistically significant (p = 0.176). Intention to start smoking among baseline non-smokers declined non-significantly in the intervention group (p = 0.064), and remained essentially unchanged in the control group, but between-group differences in changes at the 24-months follow-up (OR=0.88, 0.64-1.21) were not statistically significant (p = 0.417)., Conclusion: While a trend towards beneficial effects of the intervention regarding smoking prevalence as well as intention to start smoking among baseline non-smokers was observed, our smoking prevention trial demonstrated no significant effect of the intervention., Competing Interests: Declaration of Competing Interest TJB programmed the Smokerface App and is therefore formally the owner/rights holder. In 2017, he was offered and accepted 500 Euro per year from another German tobacco prevention charity (ginko Stiftung für Prävention, Germany) to license the Smokerface App for their school-based prevention efforts,with no influence to this study. TJB is also the owner of Smart Health Heidelberg GmbH, a software company which develops digital utehealth apps. Werner Seeger received consulting fees from United Therapeutics, Tiakis Biotech AG, Liquidia, Pieris Pharmaceuticals, Abivax, Pfizer, Medspray BV, outside the submitted work. The other authors declare no conflict of interest., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Introduction: Endobronchial foreign body aspiration is not common in adults, but it is a life-threatening event. Recurrent pneumonias by chronic retention of foreign body often lead to initial medical presentation of the patient. However, lymphoplasmacellular bronchitis with adenomatous hyperplasia and squamous epithelium metaplasia with complete or partial blockage of lobar bronchus mimicking lung tumor is rare in literature, and this particular condition is often misdiagnosed., Case Presentation: we report our experience in the diagnostic and management of two elderly patients with recurrent pneumonia, admitted in hospital for further examination. In both patients, with no history of aspiration, the cherry pit was detected during bronchoscopy and recanalization with flexible cryoprobe, surrounded by purulent secretion, occluding completely the right upper lobe in the first case, and partially the left lower lobe associated with persistent actinomycosis in the second case, with signs of local inflammation, bronchial adenomatous hyperplasia mimicking lung tumor at initial bronchoscopic examination. Histology showed a lymphoplasmacellullar bronchitis with adenomatous hyperplasia and squamous epithelium metaplasia because of chronic retention of foreign body., Conclusion: Bronchoscopy examination should be considered in cases where there is an unresolved chronic cough with recurrent pneumonia or persistent actinomycosis in patients with high risk. Cryoprobe is a safe and feasible approach for treatment of airway obstructions due to chronic foreign body retention. Furthermore, relevant findings are discussed here, along with a review of the pathologic alterations and treatment modalities seen in chronic retention of foreign body and airway injury., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Oruqaj, Krombach, Gattenloehner, Herold, Vadász, Seeger, Tello and Hecker.)

Flow cytometry and fluorescence-activated cell sorting are widely used to study endothelial cells, for which the generation of viable single-cell suspensions is an essential first step. Two enzymatic approaches, collagenase A and dispase, are widely employed for endothelial cell isolation. In this study, the utility of both enzymatic approaches, alone and in combination, for endothelial cell isolation from juvenile and adult mouse lungs was assessed, considering the number, viability, and subtype composition of recovered endothelial cell pools. Collagenase A yielded an 8-12-fold superior recovery of viable endothelial cells from lung tissue from developing mouse pups, compared to dispase, although dispase proved superior in efficiency for epithelial cell recovery. Single-cell RNA-Seq revealed that the collagenase A approach yielded a diverse endothelial cell subtype composition of recovered endothelial cell pools, with broad representation of arterial, capillary, venous, and lymphatic lung endothelial cells; while the dispase approach yielded a recovered endothelial cell pool highly enriched for one subset of general capillary endothelial cells, but poor representation of other endothelial cells subtypes. These data indicate that tissue dissociation markedly influences the recovery of endothelial cells, and the endothelial subtype composition of recovered endothelial cell pools, as assessed by single-cell RNA-Seq., (© 2024 The Authors. Cytometry Part A published by Wiley Periodicals LLC on behalf of International Society for Advancement of Cytometry.)

Three-dimensional (3D) echocardiography-derived right ventricular (RV) ejection fraction (EF) and global longitudinal strain (GLS) are valuable RV functional markers; nevertheless, they are substantially load-dependent. Global myocardial work index (GMWI) is a novel parameter calculated by the area of the RV pressure-strain loop. By adjusting myocardial deformation to instantaneous pressure, it may reflect contractility. To test this hypothesis, we enrolled 60 patients who underwent RV pressure-conductance catheterization to determine load-independent markers of RV contractility and ventriculo-arterial coupling. Detailed 3D echocardiography was also performed, and we calculated RV EF, RV GLS, and using the RV pressure trace curve, RV GWMI. While neither RV EF nor GLS correlated with Ees, GMWI strongly correlated with Ees. In contrast, RV EF and GLS showed a relationship with Ees/Ea. By dividing the population based on their Reveal Lite 2 risk classification, different characteristics were seen among the subgroups. RV GMWI may emerge as a useful clinical tool for risk stratification and follow-up in patients with RV dysfunction., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Pulmonary hypertension (PH) can lead to congestive hepatopathy, known as cardiohepatic syndrome (CHS). Hepatic congestion is associated with increased liver stiffness, which can be quantified using shear wave elastography. We aimed to investigate whether hepatic shear wave elastography detects patients at risk in the early stages of PH., Methods: Sixty-three prospectively enrolled patients undergoing right heart catheterization (52 diagnosed with PH and 11 with invasive exclusion of PH) and 52 healthy volunteers underwent assessments including echocardiography and hepatic shear wave elastography. CHS was defined as increased levels of ≥2 of the following: gamma-glutamyl transferase, alkaline phosphatase, and bilirubin. Liver stiffness was defined as normal (≤5.0 kPa) or high (>5.0 kPa)., Results: Compared with normal liver stiffness, high liver stiffness was associated with impaired right ventricular (RV) and right atrial (RA) function (median [interquartile range] RV ejection fraction: 54 [49; 57]% vs 45 [34; 51]%, p < 0.001; RA reservoir strain: 49 [41; 54]% vs 33 [22; 41]%, p < 0.001), more severe tricuspid insufficiency (p < 0.001), and higher prevalence of hepatovenous backflow (2% vs 29%, p < 0.001) and CHS (2% vs 10%, p = 0.038). In the patient subgroup with precapillary PH (n = 48), CHS and high liver stiffness were associated with increased European Society of Cardiology/European Respiratory Society 2022 risk scores (p = 0.003)., Conclusions: Shear wave liver elastography yields important information regarding right heart function and may complement risk assessment in patients with (suspected) PH., (Copyright © 2024 International Society for the Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.)

Pulmonary hypertension (PH) is a progressive, severe and to date not curable disease of the pulmonary vasculature. Alterations of the insulin-like growth factor 1 (IGF-1) system are known to play a role in vascular pathologies and IGF-binding proteins (IGFBPs) are important regulators of the bioavailability and function of IGFs. In this study, we show that circulating plasma levels of IGFBP-1, IGFBP-2 and IGFBP-3 are increased in idiopathic pulmonary arterial hypertension (IPAH) patients compared to healthy individuals. These binding proteins inhibit the IGF-1 induced IGF-1 receptor (IGF1R) phosphorylation and exhibit diverging effects on the IGF-1 induced signaling pathways in human pulmonary arterial cells (i.e. healthy as well as IPAH-hPASMCs, and healthy hPAECs). Furthermore, IGFBPs are differentially expressed in an experimental mouse model of PH. In hypoxic mouse lungs, IGFBP-1 mRNA expression is decreased whereas the mRNA for IGFBP-2 is increased. In contrast to IGFBP-1, IGFBP-2 shows vaso-constrictive properties in the murine pulmonary vasculature. Our analyses show that IGFBP-1 and IGFBP-2 exhibit diverging effects on IGF-1 signaling and display a unique IGF1R-independent kinase activation pattern in human pulmonary arterial smooth muscle cells (hPASMCs), which represent a major contributor of PAH pathobiology. Furthermore, we could show that IGFBP-2, in contrast to IGFBP-1, induces epidermal growth factor receptor (EGFR) signaling, Stat-3 activation and expression of Stat-3 target genes. Based on our results, we conclude that the IGFBP family, especially IGFBP-1, IGFBP-2 and IGFBP-3, are deregulated in PAH, that they affect IGF signaling and thereby regulate the cellular phenotype in PH., Competing Interests: Declaration of competing interest The following authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Beate Christiane Schlueter, Karin Quanz, Julia Baldauf, Aleksandar Petrovic, Clemens Ruppert, Andreas Guenther, Henning Gall, Khodr Tello, Friedrich Grimminger, Hossein-Ardeschir Ghofrani, Norbert Weissmann, Ralph Theo Schermuly, Astrid Weiss. The authors declare the following financial interests/personal relationships which may be considered as potential competing interests. Werner Seeger received consulting fees from United Therapeutics, Tiakis Biotech AG, Liquidia, Pieris Pharmaceuticalsm Abivax, Pfitzer, Medspray BV., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Bleomycin (BLM)-induced lung injury in mice is a valuable model for investigating the molecular mechanisms that drive inflammation and fibrosis and for evaluating potential therapeutic approaches to treat the disease. Given high variability in the BLM model, it is critical to accurately phenotype the animals in the course of an experiment. In the present study, we aimed to demonstrate the utility of microscopic computed tomography (µCT) imaging combined with an artificial intelligence (AI)-convolutional neural network (CNN)-powered lung segmentation for rapid phenotyping of BLM mice. µCT was performed in freely breathing C57BL/6J mice under isoflurane anesthesia on days 7 and 21 after BLM administration. Terminal invasive lung function measurement and histological assessment of the left lung collagen content were conducted as well. µCT image analysis demonstrated gradual and time-dependent development of lung injury as evident by alterations in the lung density, air-to-tissue volume ratio, and lung aeration in mice treated with BLM. The right and left lung were unequally affected. µCT-derived parameters such as lung density, air-to-tissue volume ratio, and nonaerated lung volume correlated well with the invasive lung function measurement and left lung collagen content. Our study demonstrates the utility of AI-CNN-powered µCT image analysis for rapid and accurate phenotyping of BLM mice in the course of disease development and progression. NEW & NOTEWORTHY Microscopic computed tomography (µCT) imaging combined with an artificial intelligence (AI)-convolutional neural network (CNN)-powered lung segmentation is a rapid and powerful tool for noninvasive phenotyping of bleomycin mice over the course of the disease. This, in turn, allows earlier and more reliable identification of therapeutic effects of new drug candidates, ultimately leading to the reduction of unnecessary procedures in animals in pharmacological research.

Impaired respiratory variation of right atrial pressure (RAP) in severe pulmonary hypertension (PH) suggests difficulty tolerating increased preload during inspiration. Our study explores whether this impairment links to specific factors: right ventricular (RV) diastolic function, elevated RV afterload, systolic RV function, or RV-pulmonary arterial (PA) coupling. We retrospectively evaluated respiratory RAP variation in all participants enrolled in the EXERTION study. Impaired respiratory variation was defined as end-expiratory RAP - end-inspiratory RAP ≤ 2 mm Hg. RV function and afterload were evaluated using conductance catheterization. Impaired diastolic RV function was defined as end-diastolic elastance (Eed) ≥ median (0.19 mm Hg/mL). Seventy-five patients were included; PH was diagnosed in 57 patients and invasively excluded in 18 patients. Of the 75 patients, 31 (41%) had impaired RAP variation, which was linked with impaired RV systolic function and RV-PA coupling and increased tricuspid regurgitation and Eed as compared to patients with preserved RAP variation. In backward regression, RAP variation associated only with Eed. RAP variation but not simple RAP identified impaired diastolic RV function (area under the receiver operating characteristic curve [95% confidence interval]: 0.712 [0.592, 0.832] and 0.496 [0.358, 0.634], respectively). During exercise, patients with impaired RAP variation experienced greater RV dilatation and reduced diastolic reserve and cardiac output/index compared with patients with preserved RAP variation. Preserved RAP variation was associated with a better prognosis than impaired RAP variation based on the 2022 European Society of Cardiology/European Respiratory Society risk score (chi-square P = 0.025) and survival free from clinical worsening (91% vs 71% at 1 year and 79% vs 50% at 2 years [log-rank P = 0.020]; hazard ratio: 0.397 [95% confidence interval: 0.178, 0.884]). Subgroup analyses in patients with group 1 and group 4 PH demonstrated consistent findings with those observed in the overall study cohort. Respiratory RAP variations reflect RV diastolic function, are independent of RV-PA coupling or tricuspid regurgitation, are associated with exercise-induced haemodynamic changes, and are prognostic in PH.Trial registration. NCT04663217., (© 2024. The Author(s).)

Background: The precise origin of newly formed ACTA2+ (alpha smooth muscle actin-positive) cells appearing in nonmuscularized vessels in the context of pulmonary hypertension is still debatable although it is believed that they predominantly derive from preexisting vascular smooth muscle cells (VSMCs)., Methods: Gli1 Cre-ERT2 ; tdTomato flox mice were used to lineage trace GLI1+ (glioma-associated oncogene homolog 1-positive) cells in the context of pulmonary hypertension using 2 independent models of vascular remodeling and reverse remodeling: hypoxia and cigarette smoke exposure. Hemodynamic measurements, right ventricular hypertrophy assessment, flow cytometry, and histological analysis of thick lung sections followed by state-of-the-art 3-dimensional reconstruction and quantification using Imaris software were used to investigate the contribution of GLI1+ cells to neomuscularization of the pulmonary vasculature., Results: The data show that GLI1+ cells are abundant around distal, nonmuscularized vessels during steady state, and this lineage contributes to around 50% of newly formed ACTA2+ cells around these normally nonmuscularized vessels. During reverse remodeling, cells derived from the GLI1+ lineage are largely cleared in parallel to the reversal of muscularization. Partial ablation of GLI1+ cells greatly prevented vascular remodeling in response to hypoxia and attenuated the increase in right ventricular systolic pressure and right heart hypertrophy. Single-cell RNA sequencing on sorted lineage-labeled GLI1+ cells revealed an Acta2 high fraction of cells with pathways in cancer and MAPK (mitogen-activated protein kinase) signaling as potential players in reprogramming these cells during vascular remodeling. Analysis of human lung-derived material suggests that GLI1 signaling is overactivated in both group 1 and group 3 pulmonary hypertension and can promote proliferation and myogenic differentiation., Conclusions: Our data highlight GLI1+ cells as an alternative cellular source of VSMCs in pulmonary hypertension and suggest that these cells and the associated signaling pathways represent an important therapeutic target for further studies., Competing Interests: Disclosures None.

Dual-specificity phosphatase 8 (DUSP8) plays an important role as a selective c-Jun N-terminal kinase (JNK) phosphatase in mitogen-activated protein kinase (MAPK) signaling. In this study, we found that DUSP8 is silenced by miR-147b in patients with lung adenocarcinoma (LUAD), which correlates with poor overall survival. Overexpression of DUSP8 resulted in a tumor-suppressive phenotype in vitro and in vivo experimental models, whereas silencing DUSP8 with a siRNA approach abrogated the tumor-suppressive properties. We found that miR-147b is a posttranscriptional regulator of DUSP8 that is highly expressed in patients with LUAD and is associated with lower survival. NanoString analysis revealed that the MAPK signaling pathway is mainly affected by overexpression of miR-147b, leading to increased proliferation and migration and decreased apoptosis in vitro. Moreover, induction of miR-147b promotes tumor progression in vitro and in vivo experimental models. Knockdown of miR-147b restored DUSP8, decreased tumor progression in vitro, and increased apoptosis via JNK phosphorylation. These results suggest that miR-147b plays a key role in regulating MAPK signaling in LUAD. The link between DUSP8 and miR-147b may provide novel approaches for the treatment of lung cancer., (© 2024. The Author(s).)

The mitochondrial adaptor protein p66Shc has been suggested to control life span in mice via the release of hydrogen peroxide. However, the role of p66Shc in lung aging remains unsolved. Thus, we investigated the effects of p66Shc -/- on the aging of the lung and pulmonary circulation. In vivo lung and cardiac characteristics were investigated in p66Shc -/- and wild type (WT) mice at 3, 12, and 24 months of age by lung function measurements, micro-computed tomography (µCT), and echocardiography. Alveolar number and muscularization of small pulmonary arteries were measured by stereology and vascular morphometry, respectively. Protein and mRNA levels of senescent markers were measured by western blot and PCR, respectively. Lung function declined similarly in WT and p66Shc -/- mice during aging. However, µCT analyses and stereology showed slightly enhanced signs of aging-related parameters in p66Shc -/- mice, such as a decline of alveolar density. Accordingly, p66Shc -/- mice showed higher protein expression of the senescence marker p21 in lung homogenate compared to WT mice of the corresponding age. Pulmonary vascular remodeling was increased during aging, but aged p66Shc -/- mice showed similar muscularization of pulmonary vessels and hemodynamics like WT mice. In the heart, p66Shc -/- prevented the deterioration of right ventricular (RV) function but promoted the decline of left ventricular (LV) function during aging. p66Shc -/- affects the aging process of the lung and the heart differently. While p66Shc -/- slightly accelerates lung aging and deteriorates LV function in aged mice, it seems to exert protective effects on RV function during aging.

Background: Pulmonary hypertension (PH) is a heterogeneous disease with a poor prognosis. Accurate risk stratification is essential for guiding treatment decisions in pulmonary arterial hypertension (PAH). Although various risk models have been developed for PAH, their comparative prognostic potential requires further exploration. Additionally, the applicability of risk scores in PH groups beyond group 1 remains to be investigated., Research Question: Are risk scores originally developed for PAH predictive in PH groups 1 through 4?, Study Design and Methods: We conducted a comprehensive analysis of outcomes among patients with incident PH enrolled in the multicenter worldwide Pulmonary Vascular Research Institute GoDeep meta-registry. Analyses were performed across PH groups 1 through 4 and further subgroups to evaluate the predictive value of PAH risk scores, including Registry to Evaluate Early and Long-Term PAH Disease Mangement (REVEAL) Lite 2, REVEAL 2.0, ESC/ERS 2022, Comparative, Prospective Registry of Newly Initiated Therapies for Pulmonary Hypertension (COMPERA) 3-strata, and COMPERA 4-strata., Results: Eight thousand five hundred sixty-five patients were included in the study, of whom 3,537 patients were assigned to group 1 PH, whereas 1,807 patients, 1,635 patients, and 1,586 patients were assigned to group 2 PH, group 3 PH, and group 4 PH, respectively. Pulmonary hemodynamics were impaired with median mean pulmonary arterial pressure of 42 mm Hg (interquartile range, 33-52 mm Hg) and pulmonary vascular resistance of 7 Wood units (WU) (interquartile range, 4-11 WU). All risk scores were prognostic in the entire PH population and in each of the PH groups 1 through 4. The REVEAL scores, when used as continuous prediction models, demonstrated the highest statistical prognostic power and granularity; the COMPERA 4-strata risk score provided subdifferentiation of the intermediate-risk group. Similar results were obtained when separately analyzing various subgroups (PH subgroups 1.1, 1.4.1, and 1.4.4; PH subgroups 3.1 and 3.2; group 2 with isolated postcapillary PH vs combined precapillary and postcapillary PH; patients of all groups with concomitant cardiac comorbidities; and severe [> 5 WU] vs nonsevere PH)., Interpretation: This comprehensive study with real-world data from 15 PH centers showed that PAH-designed risk scores possess predictive power in a large PH cohort, whether considered as common to the group or calculated separately for each PH group (1-4) and various subgroups., Trial Registry: ClinicalTrials.gov; No.: NCT05329714; URL: www., Clinicaltrials: gov., Competing Interests: Financial/Nonfinancial Disclosures The authors have reported to CHEST the following: A. Y. has received personal fees from MSD. H. G. has received personal fees from Actelion, AstraZeneca, Bayer, BMS, GossamerBio, GSK, Janssen-Cilag, Lilly, MSD, Novartis, OMT, Pfizer, and United Therapeutics. M. R. W. reports personal fees from MorphogenIX, Janssen, Chiesi, and Aerami; grants from British Heart Foundation and NIHR; and personal fees from MSD, Benevolent AI, and Tiakis Biotech, outside the submitted work. L. H. reports personal fees and nonfinancial support from Janssen and personal fees from MSD, Gossamer, and Altavant. D. G. K. reports support for the present manuscript from the Sheffield Biomedical Research Centre and consulting fees and other payments from Jansen Pharmaceuticals, Ferrer, Altavant, MSD, and United therapeutics. P. M. H. reports personal fees from Merck Co. S. Y. C. reports personal fees from Janssen, Bayer, Pfizer, United Therapeutics, and Acceleron Pharma and is a director, officer, and shareholder of Synhale Therapeutics. S. O. reports personal fees from MSD, Janssen, and Gallenica-Ferrer. H. A. G. has received fees from Actelion, AstraZeneca, Bayer, GSK, Janssen-Cilag, Lilly, Novartis, OMT, Pfizer, and United Therapeutics. M. J. R. has received support from Janssen Pharmaceutica and Bayer Pharma AG and speaker fees from Janssen Pharmaceutica and OMT. S. S. reports personal fees from Gossamer Bio, Merck, Keros, Janssen, United Therapeutics, and Liquidia. K. T. has received personal fees from Bayer, AstraZeneca, and Gossamer. W. S. has received consultancy fees from United Therapeutics, Tiakis Biotech AG, Liquidia, Pieris Pharmaceuticals, Abivax, Pfitzer, and Medspray BV. None declared (M. Fünderich, A.L., Y. S., O. T., A. J. S., R. T. Z., P. G. W., M. Frauendorf, A. Arvanitaki, G. G., K. S., H. R. C., R. F., I. A. G., E. B., J. S. A., A. P., S. G., A. Anthi, R. W. M., J. W., F. G.), (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: The severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) pandemic causes a high burden of acute and long-term morbidity and mortality worldwide despite global efforts in containment, prophylaxis, and therapy. With unprecedented speed, the global scientific community has generated pivotal insights into the pathogen and the host response evoked by the infection. However, deeper characterization of the pathophysiology and pathology remains a high priority to reduce morbidity and mortality of coronavirus disease 2019 (COVID-19)., Methods: NAPKON-HAP is a multi-centered prospective observational study with a long-term follow-up phase of up to 36 months post-SARS-CoV-2 infection. It constitutes a central platform for harmonized data and biospecimen for interdisciplinary characterization of acute SARS-CoV-2 infection and long-term outcomes of diverging disease severities of hospitalized patients., Results: Primary outcome measures include clinical scores and quality of life assessment captured during hospitalization and at outpatient follow-up visits to assess acute and chronic morbidity. Secondary measures include results of biomolecular and immunological investigations and assessment of organ-specific involvement during and post-COVID-19 infection. NAPKON-HAP constitutes a national platform to provide accessibility and usability of the comprehensive data and biospecimen collection to global research., Conclusion: NAPKON-HAP establishes a platform with standardized high-resolution data and biospecimen collection of hospitalized COVID-19 patients of different disease severities in Germany. With this study, we will add significant scientific insights and provide high-quality data to aid researchers to investigate COVID-19 pathophysiology, pathology, and chronic morbidity., (© 2023. The Author(s).)

Influenza A virus (IAV) infection mobilizes bone marrow-derived macrophages (BMDM) that gradually undergo transition to tissue-resident alveolar macrophages (TR-AM) in the inflamed lung. Combining high-dimensional single-cell transcriptomics with complex lung organoid modeling, in vivo adoptive cell transfer, and BMDM-specific gene targeting, we found that transitioning ("regenerative") BMDM and TR-AM highly express Placenta-expressed transcript 1 (Plet1). We reveal that Plet1 is released from alveolar macrophages, and acts as important mediator of macrophage-epithelial cross-talk during lung repair by inducing proliferation of alveolar epithelial cells and re-sealing of the epithelial barrier. Intratracheal administration of recombinant Plet1 early in the disease course attenuated viral lung injury and rescued mice from otherwise fatal disease, highlighting its therapeutic potential., (© 2024. The Author(s).)

Background: COPD is an incurable disease and a leading cause of death worldwide. In mice, fibroblast growth factor (FGF)10 is essential for lung morphogenesis, and in humans, polymorphisms in the human FGF10 gene correlate with an increased susceptibility to develop COPD., Methods: We analysed FGF10 signalling in human lung sections and isolated cells from healthy donor, smoker and COPD lungs. The development of emphysema and PH was investigated in Fgf10 +/- and Fgfr2b +/- (FGF receptor 2b) mice upon chronic exposure to cigarette smoke. In addition, we overexpressed FGF10 in mice following elastase- or cigarette smoke-induced emphysema and pulmonary hypertension (PH)., Results: We found impaired FGF10 expression in human lung alveolar walls and in primary interstitial COPD lung fibroblasts. In contrast, FGF10 expression was increased in large pulmonary vessels in COPD lungs. Consequently, we identified impaired FGF10 signalling in alveolar walls as an integral part of the pathomechanism that leads to emphysema and PH development: mice with impaired FGF10 signalling ( Fgf10 +/- and Fgfr2b +/- ) spontaneously developed lung emphysema, PH and other typical pathomechanistic features that generally arise in response to cigarette smoke exposure., Conclusion: In a therapeutic approach, FGF10 overexpression successfully restored lung alveolar and vascular structure in mice with established cigarette smoke- and elastase-induced emphysema and PH. FGF10 treatment triggered an initial increase in the number of alveolar type 2 cells that gradually returned to the basal level when the FGF10-mediated repair process progressed. Therefore, the application of recombinant FGF10 or stimulation of the downstream signalling cascade might represent a novel therapeutic strategy in the future., Competing Interests: Conflict of interest: The authors have no potential conflicts of interest to disclose., (Copyright ©The authors 2023.)

Background: The right ventricle has a complex contraction pattern of uncertain clinical relevance. We aimed to assess the relationship between right ventricular (RV) contraction pattern and RV-pulmonary arterial (PA) coupling defined by the gold-standard pressure-volume loop-derived ratio of end-systolic/arterial elastance (Ees/Ea)., Methods: Prospectively enrolled patients with suspected or confirmed pulmonary hypertension underwent three-dimensional echocardiography, standard right heart catheterization, and RV conductance catheterization. RV-PA uncoupling was categorized as severe (Ees/Ea < 0.8), moderate (Ees/Ea 0.8-1.29), and none/mild (Ees/Ea ≥ 1.3). Clinical severity was determined from hemodynamics using a truncated version of the 2022 European Society of Cardiology/European Respiratory Society risk stratification scheme., Results: Fifty-three patients were included, 23 with no/mild, 24 with moderate, and 6 with severe uncoupling. Longitudinal shortening was decreased in patients with moderate vs no/mild uncoupling (p <0.001) and intermediate vs low hemodynamic risk (p < 0.001), discriminating low risk from intermediate/high risk with an optimal threshold of 18% (sensitivity 80%, specificity 87%). Anteroposterior shortening was impaired in patients with severe vs moderate uncoupling (p = 0.033), low vs intermediate risk (p = 0.018), and high vs intermediate risk (p = 0.010), discriminating high risk from intermediate/low risk with an optimal threshold of 15% (sensitivity 100%, specificity 83%). Left ventricular (LV) end-diastolic volume was decreased in patients with severe uncoupling (p = 0.035 vs no/mild uncoupling)., Conclusions: Early RV-PA uncoupling is associated with reduced longitudinal function, whereas advanced RV-PA uncoupling is associated with reduced anteroposterior movement and LV preload, all in a risk-related fashion., Clinicaltrials: GOV: NCT04663217., Competing Interests: Disclosure statement This study was funded by Deutsche Forschungsgesellschaft, Grant Agreement Number CRC 1213, Project B08. Dr Rako, Ms Yildiz, Mr da Rocha, Dr Kremer and Dr Vadász report nonfinancial support from the University of Giessen during the conduct of the study. Dr Yogeswaran reports nonfinancial support from the University of Giessen during the conduct of the study and personal fees from MSD outside the current study. Dr Lakatos, Dr Fábián, and Dr Kovács report personal fees from Argus Cognitive, Inc. during the conduct of the study. Dr Ghofrani reports nonfinancial support from the University of Giessen and grants from the German Research Foundation during the conduct of the study and personal fees from Bayer, Actelion, Pfizer, Merck, GSK and Takeda, grants and personal fees from Novartis, Bayer HealthCare and Encysive/Pfizer, and grants from Aires, the German Research Foundation, Excellence Cluster Cardiopulmonary Research, and the German Ministry of Education and Research outside the current study. Dr Seeger reports grants from the German Research Foundation and nonfinancial support from the University of Giessen during the conduct of the current study and personal fees from Pfizer and Bayer Pharma AG outside the submitted work. Dr Gall reports grants from the German Research Foundation and nonfinancial support from the University of Giessen during the conduct of the current study and personal fees from Actelion, AstraZeneca, Bayer, BMS, GSK, Janssen-Cilag, Lilly, MSD, Novartis, OMT, Pfizer, and United Therapeutics outside the current study. Dr Richter reports nonfinancial support from the University of Giessen during the conduct of the current study and research support from United Therapeutics and Bayer, speaker honoraria from Bayer, Actelion, Mundipharma, Roche, and OMT, and consultancy fees from Bayer outside the submitted work. Dr Bauer reports consultancy fees from Bristol Myers Squibb/Pfizer and speaker fees from Bristol Myers Squibb/Pfizer, AstraZeneca and Amgen. Dr Tedford reports no direct conflicts of interest during the conduct of the current study and consulting relationships with Abiomed (research advisory board), Medtronic, Abbott (steering committee), Aria CV Inc., Acceleron/Merck (steering committee and hemodynamic core lab work for Merck), Alleviant, CareDx, Cytokinetics, Itamar, Edwards LifeSciences (national principal investigator for the RIGHT-FLOW clinical trial), Eidos Therapeutics, Lexicon Pharmaceuticals, and Gradient outside the submitted work. Dr Naeije reports relationships including consultancies, speaker’s fees and membership of advisory boards with AOP Orphan Pharmaceuticals, Johnson & Johnson, Lung Biotechnology Corporation and United Therapeutics. Dr Tello reports nonfinancial support from the University of Giessen during the conduct of the current study and speaker honoraria from Actelion and Bayer outside the submitted work. We thank Claire Mulligan, PhD (Beacon Medical Communications Ltd, Brighton, UK) for editorial assistance, funded by the University of Giessen., (Copyright © 2023 International Society for the Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.)

Preterm infants with oxygen supplementation are at high risk for bronchopulmonary dysplasia (BPD), a neonatal chronic lung disease. Inflammation with macrophage activation is central to the pathogenesis of BPD. CXCL10, a chemotactic and pro-inflammatory chemokine, is elevated in the lungs of infants evolving BPD and in hyperoxia-based BPD in mice. Here, we tested if CXCL10 deficiency preserves lung growth after neonatal hyperoxia by preventing macrophage activation. To this end, we exposed Cxcl10 knockout (Cxcl10 -/- ) and wild-type mice to an experimental model of hyperoxia (85% O 2 )-induced neonatal lung injury and subsequent regeneration. In addition, cultured primary human macrophages and murine macrophages (J744A.1) were treated with CXCL10 and/or CXCR3 antagonist. Our transcriptomic analysis identified CXCL10 as a central hub in the inflammatory network of neonatal mouse lungs after hyperoxia. Quantitative histomorphometric analysis revealed that Cxcl10 -/-  mice are in part protected from reduced alveolar. These findings were related to the preserved spatial distribution of elastic fibers, reduced collagen deposition, and protection from macrophage recruitment/infiltration to the lungs in Cxcl10 -/-  mice during acute injury and regeneration. Complimentary, studies with cultured human and murine macrophages showed that hyperoxia induces Cxcl10 expression that in turn triggers M1-like activation and migration of macrophages through CXCR3. Finally, we demonstrated a temporal increase of macrophage-related CXCL10 in the lungs of infants with BPD. In conclusion, our data demonstrate macrophage-derived CXCL10 in experimental and clinical BPD that drives macrophage chemotaxis through CXCR3, causing pro-fibrotic lung remodeling and arrest of alveolarization. Thus, targeting the CXCL10-CXCR3 axis could offer a new therapeutic avenue for BPD., (© 2023. Japanese Society of Inflammation and Regeneration.)

Background: Fibroblast growth factor 23 (FGF-23) has been associated with left ventricular hypertrophy (LVH) and heart failure. However, its role in right ventricular (RV) remodeling and RV failure is unknown. This study analyzed the utility of FGF-23 as a biomarker of RV function in patients with pulmonary hypertension (PH)., Methods: In this observational study, FGF-23 was measured in the plasma of patients with PH (n = 627), dilated cardiomyopathy (DCM, n = 59), or LVH with severe aortic stenosis (n = 35). Participants without LV or RV abnormalities served as controls (n = 36)., Results: Median FGF-23 plasma levels were higher in PH patients than in healthy controls (p < 0.001). There were no significant differences between PH, DCM, and LVH patients. Analysis across tertiles of FGF-23 levels in PH patients revealed an association between higher FGF-23 levels and higher levels of NT-proBNP and worse renal function. Furthermore, patients in the high-FGF-23 tertile had a higher pulmonary vascular resistance (PVR), mean pulmonary artery pressure, and right atrial pressure and a lower cardiac index (CI) than patients in the low tertile (p < 0.001 for all comparisons). Higher FGF-23 levels were associated with higher RV end-diastolic diameter and lower tricuspid annular plane systolic excursions (TAPSE) and TAPSE/PASP. Receiver operating characteristic analysis revealed FGF-23 as a good predictor of RV maladaptation, defined as TAPSE < 17 mm and CI < 2.5 L/min/m 2 . Association of FGF-23 with parameters of RV function was independent of the glomerular filtration rate in regression analysis., Conclusion: FGF-23 may serve as a biomarker for maladaptive RV remodeling in patients with PH., (© 2023. The Author(s).)

Aims: Commercially available integrated software for echocardiographic measurement of stroke work (SW) is increasingly used for the right ventricle, despite a lack of validation. We sought to assess the validity of this method [echo-based myocardial work (MW) module] vs. gold-standard invasive right ventricular (RV) pressure-volume (PV) loops., Methods and Results: From the prospectively recruiting EXERTION study (NCT04663217), we included 42 patients [34 patients with pulmonary arterial hypertension (PAH) or chronic thromboembolic pulmonary hypertension (CTEPH) and 8 patients with absence of cardiopulmonary disease] with RV echocardiography and invasive PV catheterization. Echocardiographic SW was assessed as RV global work index (RVGWI) generated via the integrated pressure-strain MW software. Invasive SW was calculated as the area bounded by the PV loop. An additional parameter derived from the MW module, RV global wasted work (RVGWW), was correlated with PV loop measures. RVGWI significantly correlated with invasive PV loop-derived RV SW in the overall cohort [rho = 0.546 (P < 0.001)] and the PAH/CTEPH subgroup [rho = 0.568 (P < 0.001)]. Overall, RVGWW correlated with invasive measures of arterial elastance (Ea), the ratio of end-systolic elastance (Ees)/Ea, and end-diastolic elastance (Eed) significantly., Conclusions: Integrated echo measurement of pressure-strain loop-derived SW correlates with PV loop-based assessment of RV SW. Wasted work correlates with invasive measures of load-independent RV function. Given the methodological and anatomical challenges of RV work assessment, evolution of this approach by incorporating more elaborated echo analysis data and an RV reference curve might improve its reliability to mirror invasively assessed RV SW., (© 2023 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of European Society of Cardiology.)

Long noncoding RNAs (lncRNAs) influence the transcription of gene networks in many cell types, but their role in tumor-associated macrophages (TAMs) is still largely unknown. We found that the lncRNA ADPGK-AS1 was substantially upregulated in artificially induced M2-like human macrophages, macrophages exposed to lung cancer cells in vitro, and TAMs from human lung cancer tissue. ADPGK-AS1 is partly located within mitochondria and binds to the mitochondrial ribosomal protein MRPL35. Overexpression of ADPGK-AS1 in macrophages upregulates the tricarboxylic acid cycle and promotes mitochondrial fission, suggesting a phenotypic switch toward an M2-like, tumor-promoting cytokine release profile. Macrophage-specific knockdown of ADPGK-AS1 induces a metabolic and phenotypic switch (as judged by cytokine profile and production of reactive oxygen species) to a pro-inflammatory tumor-suppressive M1-like state, inhibiting lung tumor growth in vitro in tumor cell-macrophage cocultures, ex vivo in human tumor precision-cut lung slices, and in vivo in mice. Silencing ADPGK-AS1 in TAMs may thus offer a novel therapeutic strategy for lung cancer., (© 2023 The Authors. Published under the terms of the CC BY NC ND 4.0 license.)

Background: Right ventricular (RV) diastolic dysfunction may be prognostic in pulmonary hypertension (PH). However, its assessment is complex and relies on conductance catheterisation. We aimed to evaluate echocardiography-based parameters as surrogates of RV diastolic function, provide validation against the gold standard, end-diastolic elastance (Eed), and define the prognostic impact of echocardiography-derived RV diastolic dysfunction., Methods: Patients with suspected PH who underwent right heart catheterisation including conductance catheterisation were prospectively recruited. In this study population, an echocardiography-based RV diastolic function surrogate was derived. Survival analyses were performed in patients with precapillary PH in the Giessen PH Registry, with external validation in patients with pulmonary arterial hypertension at Sapienza University (Rome)., Results: In the derivation cohort (n=61), the early/late diastolic tricuspid inflow velocity ratio (E/A) and early tricuspid inflow velocity/early diastolic tricuspid annular velocity ratio (E/e') did not correlate with Eed (p>0.05). Receiver operating characteristic analysis revealed a large area under the curve (AUC) for the peak lateral tricuspid annulus systolic velocity/right atrial area index ratio (S'/RAAi) to detect elevated Eed (AUC 0.913, 95% confidence interval (CI) 0.839-0.986) and elevated end-diastolic pressure (AUC 0.848, 95% CI 0.699-0.998) with an optimal threshold of 0.81 m 2 ·s -1 ·cm -1 . Subgroup analyses demonstrated a large AUC in patients with preserved RV systolic function (AUC 0.963, 95% CI 0.882-1.000). Survival analyses confirmed the prognostic relevance of S'/RAAi in the Giessen PH Registry (n=225) and the external validation cohort (n=106)., Conclusions: Our study demonstrates the usefulness of echocardiography-derived S'/RAAi for noninvasive assessment of RV diastolic function and prognosis in PH., Competing Interests: Conflicts of interest: A. Yogeswaran reports non-financial support from the University of Giessen during the conduct of the study, and personal fees from MSD outside the submitted work. Conflicts of interest: Z.A. Rako and N.C. Kremer report non-financial support from the University of Giessen during the conduct of the study. Conflicts of interest: S. Yildiz has no conflict of interest or disclosures. Conflicts of interest: H.A. Ghofrani reports grants from the German Research Foundation and non-financial support from the University of Giessen during the conduct of the study, and personal fees from Bayer, Actelion, Pfizer, Merck, GSK, and Takeda, grants and personal fees from Novartis, Bayer HealthCare, and Encysive/Pfizer, and grants from Aires, the German Research Foundation, Excellence Cluster Cardio-pulmonary Research, and the German Ministry for Education and research outside the submitted work. Conflicts of interest: W. Seeger reports grants from the German Research Foundation and non-financial support from the University of Giessen during the conduct of the study, and personal fees from Pfizer and Bayer Pharma AG outside the submitted work. Conflicts of interest: B. Brito da Rocha has no conflict of interest and nothing to disclose. Conflicts of interest: H. Gall reports grants from the German Research Foundation and non-financial support from the University of Giessen during the conduct of the study, and personal fees from Actelion, AstraZeneca, Bayer, BMS, GSK, Janssen-Cilag, Lilly, MSD, Novartis, OMT, Pfizer, and United Therapeutics outside the submitted work. Conflicts of interest: P. Douschan, S. Papa, C.D. Vizza and D. Filomena have no conflict of interest or disclosures. Conflicts of interest: R.J. Tedford reports no direct conflicts of interest related to this manuscript; he reports general disclosures to include consulting relationships with Medtronic, Abbott, Aria CV Inc., Acceleron, Alleviant, CareDx, Cytokinetics, Itamar, Edwards LifeSciences, Eidos Therapeutics, Lexicon Pharmaceuticals, and Gradient. Conflicts of interest: R.J. Tedford is the national principal investigator for the RIGHT-FLOW clinical trial (Edwards), serves on a steering committee for Merck and Abbott as well as a research advisory board for Abiomed. He also does hemodynamic core lab work for Merck. Conflicts of interest: R. Naeije has relationships with drug companies including AOP Orphan Pharmaceuticals, Johnson & Johnson, Lung Biotechnology Corporation, and United Therapeutics. In addition to being an investigator in trials involving these companies, relationships include consultancy service, research grants, and membership of scientific advisory boards. Conflicts of interest: M.J. Richter reports grants from the German Research Foundation and non-financial support from the University of Giessen during the conduct of the study, and personal fees from Actelion, Bayer, Janssen-Cilag, MSD, OMT, Pfizer, and United Therapeutics outside the submitted work. Conflicts of interest: R. Badagliacca received grants and personal fees from Ferrer, Dompè, AOP, United Therapeutics, MSD, Janssen, and Bayer outside the submitted work. Conflicts of interest: K. Tello reports grants from the German Research Foundation and non-financial support from the University of Giessen during the conduct of the study, and personal fees from Actelion outside the submitted work., (Copyright ©The authors 2023.)

Introduction: Acute respiratory distress syndrome (ARDS) is a common complication of influenza virus (IV) infection. During ARDS, alveolar protein concentrations often reach 40-90% of plasma levels, causing severe impairment of gas exchange and promoting deleterious alveolar remodeling. Protein clearance from the alveolar space is at least in part facilitated by the multi-ligand receptor megalin through clathrin-mediated endocytosis., Methods: To investigate whether IV infection impairs alveolar protein clearance, we examined albumin uptake and megalin expression in MLE-12 cells and alveolar epithelial cells (AEC) from murine precision-cut lung slices (PCLS) and in vivo, under IV infection conditions by flow cytometry and western blot. Transcriptional levels from AEC and broncho-alveolar lavage (BAL) cells were analyzed in an in-vivo mouse model by RNAseq., Results: IV significantly downregulated albumin uptake, independently of activation of the TGF-β1/GSK3β axis that has been previously implicated in the regulation of megalin function. Decreased plasma membrane abundance, total protein levels, and mRNA expression of megalin were associated with this phenotype. In IV-infected mice, we identified a significant upregulation of matrix metalloproteinase (MMP)-14 in BAL fluid cells. Furthermore, the inhibition of this protease partially recovered total megalin levels and albumin uptake., Discussion: Our results suggest that the previously described MMP-driven shedding mechanisms are potentially involved in downregulation of megalin cell surface abundance and clearance of excess alveolar protein. As lower alveolar edema protein concentrations are associated with better outcomes in respiratory failure, our findings highlight the therapeutic potential of a timely MMP inhibition in the treatment of IV-induced ARDS., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2023 Alberro-Brage, Kryvenko, Malainou, Günther, Morty, Seeger, Herold, Samakovlis and Vadász.)

Background: Aspiration of stomach content or saliva in critical conditions-e.g., shock, intoxication, or resuscitation-can lead to acute lung injury. While various biomarkers in bronchoalveolar lavage fluids have been studied for diagnosing aspiration, none have been conclusively established as early indicators of lung damage. This study aims to evaluate the diagnostic value of pepsin, bile acid, and other biomarkers for detecting aspiration in an intensive care unit (ICU)., Materials and Methods: In this study, 50 ICU patients were enrolled and underwent intubation before admission. The evaluation of aspiration was based on clinical suspicion or documented instances of observed events. Tracheal secretion (TS) samples were collected within 6 h after intubation using sterile suction catheters. Additional parameters, including IL-6, pepsin, and bile acid, were determined for analysis. Pepsin levels were measured with an ELISA kit, while bile acid, uric acid, glucose, IL-6, and pH value in the tracheal secretion were analyzed using standardized lab methods., Results: The 50 patients admitted to the ICU with various diagnoses. The median survival time for the entire cohort was 52 days, and there was no significant difference in survival between patients with aspiration pneumonia (AP) and those with other diagnoses ( p = 0.69). Among the AP group, the average survival time was 50.51 days (±8.1 SD; 95% CI 34.63-66.39), while patients with other diagnoses had a mean survival time of 32.86 days (±5.1 SD; 95% CI 22.9-42.81); the survival group comparison did not yield statistically significant results. The presence of pepsin or bile acid in TS patients did not significantly impact survival or the diagnosis of aspiration. The p -values for the correlations between pepsin and bile acid with the aspiration diagnosis were p = 0.53 and p > 0.99, respectively; thus, pepsin and bile acid measurements did not significantly affect survival outcomes or enhance the accuracy of diagnosing aspiration pneumonia., Conclusions: The early and accurate diagnosis of aspiration is crucial for optimal patient care. However, based on this study, pepsin concentration alone may not reliably indicate aspiration, and bile acid levels also show limited association with the diagnosis. Further validation studies are needed to assess the clinical usefulness and reliability of gastric biomarkers in diagnosing aspiration-related conditions. Such future studies would provide valuable insights for improving aspiration diagnosis and enhancing patient care.

Background The impact of changes in Doppler-derived kidney venous flow in heart failure (HF) is not well studied. We aimed to investigate the association of Doppler-derived kidney venous stasis index (KVSI) and intrakidney venous-flow (IKVF) patterns with adverse cardiorenal outcomes in patients with HF. Methods and Results In this observational cohort study, consecutive inpatients with HF referred to a nephrologist because of a history of diuretic resistance and abnormal kidney function (n=216) underwent spectral kidney assessments after admission (Doppler 1) and 25 to 35 days later (Doppler 2) to identify IKVF patterns (continuous/pulsatile/biphasic/monophasic) and KVSI levels. Cox proportional hazard regression models were used to evaluate the associations between KVSI/IKVF patterns at Doppler 1 as well as changes from Doppler 1 to Doppler 2 and risk of cardiorenal events up to 18 months after admission. Worsening HF or death occurred in 126 patients. Both baseline KVSI (hazard ratio [HR], 1.49 [95% CI, 1.37-1.61] per 0.1-unit increase) and baseline IKVF pattern (HR, 2.47 [95% CI, 2.01-3.04] per 1 pattern severity increase) were significantly associated with worsening HF/death. Increases in both KVSI and IKVF pattern severity from Doppler 1 to 2 were also associated with an increased risk of worsening HF/death (HR, 3.00 [95% CI, 2.08-4.32] per 0.1-unit increase change; and HR, 6.73 [95% CI, 3.27-13.86] per 1 pattern increase in severity change, respectively). Similar results were observed for kidney outcomes. Conclusions Baseline kidney venous flow predicted adverse cardiorenal events, and inclusion of serial kidney venous flow in cardiorenal risk stratification could facilitate clinical decision-making for patients with HF. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT03039959.

Background: Cardiac interactions with organs such as the liver or kidneys have been described in different cardiovascular diseases. However, the clinical relevance of hepatorenal dysfunction in chronic thromboembolic pulmonary hypertension (CTEPH) remains unclear. We determined the association of hepatorenal dysfunction (measured using the Model for End-stage Liver Disease Sodium [MELDNa] score) with right heart function and survival in patients with CTEPH., Methods: We analyzed all patients with CTEPH in the Giessen Pulmonary Hypertension Registry who had available MELDNa scores and were not taking vitamin K antagonists. The MELDNa score was calculated as MELD score - serum Na - (0.025 * MELD score * (140 - serum Na)) + 140; the MELD score was calculated as 10*(0.957*ln(creatinine)+0.378*ln(bilirubin)+1.12*ln(International Normalized Ratio))+6.43., Results: Seventy-two patients were included (74% female; median [Q1, Q3] MELDNa: 9 [6, 11]). MELDNa correlated well with right atrial and ventricular function and pulmonary hemodynamics. Forward regression analysis revealed that hepatorenal dysfunction mainly depends on right atrial strain and tricuspid regurgitation, but not right ventricular systolic dysfunction. Hepatorenal dysfunction predicted mortality at baseline and follow-up (adjusted hazard ratios [95% confidence intervals] per unit increase of MELDNa: 1.6 [1.1, 2.4] and 1.8 [1.1, 2.9], respectively). Changes in hepatorenal function also predicted mortality., Conclusion: Hepatorenal dysfunction in CTEPH is primarily associated with venous congestion rather than cardiac forward failure. As a surrogate parameter for hepatorenal dysfunction, MELDNa is a simple method to identify at-risk patients at baseline and follow-up., Competing Interests: AY reports non-financial support from the University of Giessen during the conduct of the study, and personal fees from MSD outside the submitted work. MR reports grants from the German Research Foundation and non-financial support from the University of Giessen during the conduct of the study, and grants from United Therapeutics, grants and personal fees from Bayer, and personal fees from Actelion, Mundipharma, Roche, and OMT outside the submitted work. FG reports no competing interests. WS reports grants from the German Research Foundation and non-financial support from the University of Giessen during the conduct of the study, and personal fees from Pfizer and Bayer Pharma AG outside the submitted work. HAG reports grants from the German Research Foundation and non-financial support from the University of Giessen during the conduct of the study, and personal fees from Bayer, Actelion, Pfizer, Merck, GSK, and Takeda, grants and personal fees from Novartis, Bayer HealthCare, and Encysive/Pfizer, and grants from Aires, the German Research Foundation, Excellence Cluster Cardiopulmonary Research, and the German Ministry for Education and Research outside the submitted work. HG reports grants from the German Research Foundation and non-financial support from the University of Giessen during the conduct of the study, and personal fees from Actelion, AstraZeneca, Bayer, BMS, GSK, Janssen-Cilag, Lilly, MSD, Novartis, OMT, Pfizer, and United Therapeutics outside the submitted work. KT reports grants from the German Research Foundation and non-financial support from the University of Giessen during the conduct of the study, and personal fees from Actelion and Bayer outside the submitted work. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Yogeswaran, Zedler, Richter, Steinke, Rako, Kremer, Grimminger, Seeger, Ghofrani, Gall and Tello.)

Tumor-associated macrophages (TAM), including antitumor M1-like TAMs and protumor M2-like TAMs, are transcriptionally dynamic innate immune cells with diverse roles in lung cancer development. Epigenetic regulators are key in controlling macrophage fate in the heterogeneous tumor microenvironment. Here, we demonstrate that the spatial proximity of HDAC2-overexpressing M2-like TAMs to tumor cells significantly correlates with poor overall survival of lung cancer patients. Suppression of HDAC2 in TAMs altered macrophage phenotype, migration, and signaling pathways related to interleukins, chemokines, cytokines, and T-cell activation. In coculture systems of TAMs and cancer cells, suppressing HDAC2 in TAMs resulted in reduced proliferation and migration, increased apoptosis of cancer cell lines and primary lung cancer cells, and attenuated endothelial cell tube formation. HDAC2 regulated the M2-like TAM phenotype via acetylation of histone H3 and transcription factor SP1. Myeloid cell-specific deletion of Hdac2 and pharmacologic inhibition of class I HDACs in four different murine lung cancer models induced the switch from M2-like to M1-like TAMs, altered infiltration of CD4+ and CD8+ T cells, and reduced tumor growth and angiogenesis. TAM-specific HDAC2 expression may provide a biomarker for lung cancer stratification and a target for developing improved therapeutic approaches., Significance: HDAC2 inhibition reverses the protumor phenotype of macrophages mediated by epigenetic modulation induced by the HDAC2-SP1 axis, indicating a therapeutic option to modify the immunosuppressive tumor microenvironment., (©2023 American Association for Cancer Research.)

Background: Electronic cigarette (e-cigarette) vapour is gaining popularity as an alternative to tobacco smoking and can induce acute lung injury. However, the specific role of nicotine in e-cigarette vapour and its long-term effects on the airways, lung parenchyma and vasculature remain unclear., Results: In vitro exposure to nicotine-containing e-cigarette vapour extract (ECVE) or to nicotine-free e-cigarette vapour extract (NF ECVE) induced changes in gene expression of epithelial cells and pulmonary arterial smooth muscle cells (PASMCs), but ECVE in particular caused functional alterations ( e.g. a decrease in human and mouse PASMC proliferation by 29.3±5.3% and 44.3±8.4%, respectively). Additionally, acute inhalation of nicotine-containing e-cigarette vapour (ECV) but not nicotine-free e-cigarette vapour (NF ECV) increased pulmonary endothelial permeability in isolated lungs. Long-term in vivo exposure of mice to ECV for 8 months significantly increased the number of inflammatory cells, in particular lymphocytes, compared to control and NF ECV in the bronchoalveolar fluid (BALF) (ECV: 853.4±150.8 cells·mL -1 ; control: 37.0±21.1 cells·mL -1 ; NF ECV: 198.6±94.9 cells·mL -1 ) and in lung tissue (ECV: 25.7±3.3 cells·mm -3 ; control: 4.8±1.1 cells·mm -3 ; NF ECV: 14.1±2.2 cells·mm -3 ). BALF cytokines were predominantly increased by ECV. Moreover, ECV caused significant changes in lung structure and function ( e.g. increase in airspace by 17.5±1.4% compared to control), similar to mild tobacco smoke-induced alterations, which also could be detected in the NF ECV group, albeit to a lesser degree. In contrast, the pulmonary vasculature was not significantly affected by ECV or NF ECV., Conclusions: NF ECV components induce cell type-specific effects and mild pulmonary alterations, while inclusion of nicotine induces significant endothelial damage, inflammation and parenchymal alterations., Competing Interests: Conflict of interest: All authors have nothing to disclose., (Copyright ©The authors 2023.)

Purpose: The relevance of dual-energy computed tomography (DECT) for the detection of chronic thromboembolic pulmonary hypertension (CTEPH) still lies behind V/Q-SPECT in current clinical guidelines. Therefore, our study aimed to assess the diagnostic accuracy of DECT compared to V/Q-SPECT with invasive pulmonary angiogram (PA) serving as the reference standard., Methods: A total of 28 patients (mean age 62.1 years ± 10.6SD; 18 women) with clinically suspected CTEPH were retrospectively included. All patients received DECT with the calculation of iodine maps, V/Q-SPECT, and PA. Results of DECT and V/Q-SPECT were compared, and the percent of agreement, concordance (utilizing Cohen's kappa), and accuracy (kappa 2 ) to PA were calculated. Furthermore, radiation doses were analyzed and compared., Results: In total, 18 patients were diagnosed with CTEPH (mean age 62.4 years ± 11.0SD; 10 women) and 10 patients had other diseases. Compared to PA, accuracy and concordance for DECT were superior to V/Q-SPECT in all patients (88.9% vs. 81.3%; k = 0.764 vs. k = 0.607) and in CTEPH patients (82.4% vs. 70.1%; k = 0.694 vs. k = 0.560). Furthermore, the mean radiation dose was significantly lower for DECT vs. V/Q-SPECT ( p = 0.0081)., Conclusion: In our patient cohort, DECT is at least equivalent to V/Q-SPECT in diagnosing CTEPH and has the added advantage of significantly lower radiation doses in combination with simultaneous assessment of lung and heart morphology. Hence, DECT should be the subject of ongoing research, and if our results are further confirmed, it should be implemented in future diagnostic PH algorithms at least on par with V/Q-SPECT., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Schüssler, Lug, Kremer, Harth, Kriechbaum, Richter, Guth, Wiedenroth, Tello, Steiner, Seeger, Krombach and Roller.)

Rationale: Tobacco smoking and air pollution are primary causes of chronic obstructive pulmonary disease (COPD). However, only a minority of smokers develop COPD. The mechanisms underlying the defense against nitrosative/oxidative stress in nonsusceptible smokers to COPD remain largely unresolved. Objectives: To investigate the defense mechanisms against nitrosative/oxidative stress that possibly prevent COPD development or progression. Methods: Four cohorts were investigated: 1 ) sputum samples (healthy, n  = 4; COPD, n  = 37), 2 ) lung tissue samples (healthy, n  = 13; smokers without COPD, n  = 10; smoker+COPD, n  = 17), 3 ) pulmonary lobectomy tissue samples (no/mild emphysema, n  = 6), and 4 ) blood samples (healthy, n  = 6; COPD, n  = 18). We screened 3-nitrotyrosine (3-NT) levels, as indication of nitrosative/oxidative stress, in human samples. We established a novel in vitro model of a cigarette smoke extract (CSE)-resistant cell line and studied 3-NT formation, antioxidant capacity, and transcriptomic profiles. Results were validated in lung tissue, isolated primary cells, and an ex vivo model using adeno-associated virus-mediated gene transduction and human precision-cut lung slices. Measurements and Main Results: 3-NT levels correlate with COPD severity of patients. In CSE-resistant cells, nitrosative/oxidative stress upon CSE treatment was attenuated, paralleled by profound upregulation of heme oxygenase-1 (HO-1). We identified carcinoembryonic antigen cell adhesion molecule 6 (CEACAM6) as a negative regulator of HO-1-mediated nitrosative/oxidative stress defense in human alveolar type 2 epithelial cells (hAEC2s). Consistently, inhibition of HO-1 activity in hAEC2s increased the susceptibility toward CSE-induced damage. Epithelium-specific CEACAM6 overexpression increased nitrosative/oxidative stress and cell death in human precision-cut lung slices on CSE treatment. Conclusions: CEACAM6 expression determines the hAEC2 sensitivity to nitrosative/oxidative stress triggering emphysema development/progression in susceptible smokers.

Background: The ability of the right ventricle (RV) to adapt to an increased pressure afterload determines survival in patients with pulmonary arterial hypertension. At present, there are no specific treatments available to prevent RV failure, except for heart/lung transplantation. The wingless/int-1 (Wnt) signaling pathway plays an important role in the development of the RV and may also be implicated in adult cardiac remodeling., Methods: Molecular, biochemical, and pharmacological approaches were used both in vitro and in vivo to investigate the role of Wnt signaling in RV remodeling., Results: Wnt/β-catenin signaling molecules are upregulated in RV of patients with pulmonary arterial hypertension and animal models of RV overload (pulmonary artery banding-induced and monocrotaline rat models). Activation of Wnt/β-catenin signaling leads to RV remodeling via transcriptional activation of FOSL1 and FOSL2 (FOS proto-oncogene [FOS] like 1/2, AP-1 [activator protein 1] transcription factor subunit). Immunohistochemical analysis of pulmonary artery banding -exposed BAT-Gal (β-catenin-activated transgene driving expression of nuclear β-galactosidase) reporter mice RVs exhibited an increase in β-catenin expression compared with their respective controls. Genetic inhibition of β-catenin, FOSL1/2, or WNT3A stimulation of RV fibroblasts significantly reduced collagen synthesis and other remodeling genes. Importantly, pharmacological inhibition of Wnt signaling using inhibitor of PORCN (porcupine O-acyltransferase), LGKK-974 attenuated fibrosis and cardiac hypertrophy leading to improvement in RV function in both, pulmonary artery banding - and monocrotaline-induced RV overload., Conclusions: Wnt- β-Catenin-FOSL signaling is centrally involved in the hypertrophic RV response to increased afterload, offering novel targets for therapeutic interference with RV failure in pulmonary hypertension., Competing Interests: Disclosures None.

Background: Volume overload is often associated with clinical deterioration in precapillary pulmonary hypertension (PH). However, thorough assessment of volume overload is complex and therefore not routinely performed. We examined whether estimated plasma volume status (ePVS) is associated with central venous congestion and prognosis in patients with idiopathic pulmonary arterial hypertension (IPAH) or chronic thromboembolic PH (CTEPH)., Methods: We included all patients with incident IPAH or CTEPH enrolled in the Giessen PH Registry between January 2010 and January 2021. Plasma volume status was estimated using the Strauss formula., Results: In total, 381 patients were analyzed. Patients with high ePVS (≥4.7 vs. <4.7 ml/g) at baseline showed significantly increased central venous pressure (CVP; median [Q1, Q3]: 8 [5, 11] mmHg vs. 6 [3, 10] mmHg) and pulmonary arterial wedge pressure (10 [8, 15] mmHg vs. 8 [6, 12] mmHg), while right ventricular function was not altered. In multivariate stepwise backward Cox regression, ePVS was independently associated with transplant-free survival at baseline and during follow-up (hazard ratio [95% confidence interval]: 1.24 [0.96, 1.60] and 2.33 [1.49, 3.63], respectively). An intra-individual decrease in ePVS was associated with a decrease in CVP and predicted prognosis in univariate Cox regression. Patients with high ePVS without edema had lower transplant-free survival than those with normal ePVS without edema. In addition, high ePVS was associated with cardiorenal syndrome., Conclusions: In precapillary PH, ePVS is associated with congestion and prognosis. High ePVS without edema may represent an under-recognized subgroup with poor prognosis., Competing Interests: AY reports personal fees from MSD outside the submitted work. KT reports personal fees from Actelion and Bayer outside the submitted work. NS reports personal fees from Actelion outside the submitted work. WS reports personal fees from Pfizer and Bayer Pharma AG outside the submitted work. HAG reports personal fees from Bayer, Actelion, Pfizer, Merck, GSK, and Takeda, grants and personal fees from Novartis, Bayer HealthCare, and Encysive/Pfizer, and grants from Aires outside the submitted work. HG reports personal fees from Actelion, AstraZeneca, Bayer, BMS, GSK, Janssen-Cilag, Lilly, MSD, Novartis, OMT, Pfizer, and United Therapeutics outside the submitted work. MR reports grants from United Therapeutics, grants and personal fees from Bayer, and personal fees from Actelion, Mundipharma, Roche, and OMT outside the submitted work. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2023 Yogeswaran, Richter, Husain-Syed, Rako, Sommer, Grimminger, Seeger, Ghofrani, Gall and Tello.)

Background: Right atrial (RA) imaging has emerged as a promising tool for the evaluation of patients with pulmonary hypertension (PH), albeit without systematic validation., Methods: PubMed, Web of Science and the Cochrane library were searched for studies investigating the prognostic value of RA imaging assessment in patients with PH from 2000 to June 2021 (PROSPERO Identifier: CRD42020212850). An inverse variance-weighted meta-analysis of univariable hazard ratios (HRs) was performed using a random effects model., Results: Thirty-five studies were included (3,476 patients with PH; 74% female, 86% pulmonary arterial hypertension). Risk of bias was low/moderate (Quality of Prognosis Studies checklist). RA area (HR 1.06; 95% confidence interval [CI] 1.04-1.08), RA indexed area (HR 1.09; 95% CI 1.04-1.14), RA peak longitudinal strain (PLS; HR 0.94; 95% CI 0.91-0.97) and RA total emptying fraction (HR 0.96; 95% CI 0.94-0.98) were significantly associated with combined end-points including death, clinical worsening and/or lung transplantation; RA volume and volume index showed marginal significant associations. RA area (HR 1.06; 95% CI 1.04-1.07), RA indexed area (HR 1.12; 95% CI 1.07-1.17) and RA PLS (HR 0.98; 95% CI 0.97-0.99) showed significant associations with mortality; RA total emptying fraction showed a marginal association., Conclusions: Imaging-based RA assessment qualifies as a relevant prognostic marker in PH. RA area reliably predicts composite end-points and mortality, which underscores its clinical utility. RA PLS emerged as a promising imaging measure, but is currently limited by the number of studies and different acquisition methods., (Copyright © 2022 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.)

Background: Parametric imaging has taken a steep rise in recent years and non-cardiac applications are of increasing interest. Therefore, the aim of our study was to assess right (RV) and left ventricular (LV) blood pool T1 and T2 values in patients with chronic thromboembolic pulmonary hypertension (CTEPH) compared to control subjects and their correlation to pulmonary hemodynamic., Methods: 26 patients with CTEPH (mean age 64.8 years ± 12.8 SD; 15 female), who underwent CMR and right heart catheterization (RHC) before and 6-months after balloon pulmonary angioplasty (BPA), were retrospectively included. Ventricular blood pool values were measured, compared to control subjects (mean age 40.5 years ± 12.8 SD; 16 female) and correlated to invasive measures (CI, mPAP, PVR)., Results: In both, control subjects and CTEPH patients, RVT1 and RVT2 were significantly reduced compared to LVT1 and LVT2. Compared to control subjects, RVT2 was significantly reduced in CTEPH patients ( p = 0.0065) and increased significantly after BPA ( p = 0.0048). Moreover, RVT2 was positively correlated with CI and negatively correlated with mPAP and PVR before (r = 0.5155, r = -0.2541, r = -0.4571) and after BPA (r = 0.4769, r = -0.2585, r = -0.4396)., Conclusion: Ventricular blood pool T2 mapping might be novel non-invasive CMR imaging marker for assessment of disease severity, prognosis, follow-up and even therapy monitoring in PH.

Background: The brain-derived neurotrophic factor (BDNF) may promote development of pulmonary hypertension and right ventricular (RV) failure. However, BDNF plasma levels were decreased in patients with left ventricular (LV) failure. Therefore, we investigated BDNF plasma levels in pulmonary hypertension patients and the role of BDNF in mouse models of pulmonary hypertension and isolated RV failure., Methods: BDNF plasma levels were correlated to pulmonary hypertension in two patient cohorts, including either post- and pre-capillary pulmonary hypertension patients (first cohort) or only pre-capillary pulmonary hypertension patients (second cohort). In the second cohort, RV dimensions and load-independent function were determined by imaging and pressure-volume catheter measurements, respectively. For induction of isolated RV pressure overload, heterozygous Bdnf knockout ( Bdnf +/- ) mice were subjected to pulmonary arterial banding (PAB). For induction of pulmonary hypertension, mice with inducible knockout of BDNF in smooth muscle cells ( Bdnf / Smmhc knockout) were exposed to chronic hypoxia., Results: Plasma BDNF levels were decreased in patients with pulmonary hypertension. Following adjustment for covariables, BDNF levels negatively correlated in both cohorts with central venous pressure. In the second cohort, BDNF levels additionally negatively correlated with RV dilatation. In animal models, BDNF downregulation attenuated RV dilatation in Bdnf + / - mice after PAB or hypoxic Bdnf / Smmhc knockout mice, although they developed pulmonary hypertension to a similar extent., Conclusions: Similar to LV failure, circulating levels of BDNF were decreased in pulmonary hypertension patients, and low BDNF levels were associated with right heart congestion. Decreased BDNF levels did not worsen RV dilatation in animal models, and thus, may be the consequence, but not the cause of RV dilatation., Competing Interests: Conflict of interest: No disclosures., (Copyright ©The authors 2023.)

Rationale: Although type II alveolar epithelial cells (AEC2s) are chronically injured in idiopathic pulmonary fibrosis (IPF), they contribute to epithelial regeneration in IPF. Objectives: We hypothesized that Notch signaling may contribute to AEC2 proliferation, dedifferentiation characterized by loss of surfactant processing machinery, and lung fibrosis in IPF. Methods: We applied microarray analysis, kinome profiling, flow cytometry, immunofluorescence analysis, western blotting, quantitative PCR, and proliferation and surface activity analysis to study epithelial differentiation, proliferation, and matrix deposition in vitro (AEC2 lines, primary murine/human AEC2s), ex vivo (human IPF-derived precision-cut lung slices), and in vivo (bleomycin and pepstatin application, Notch1 [Notch receptor 1] intracellular domain overexpression). Measurements and Main Results: We document here extensive SP-B and -C (surfactant protein-B and -C) processing defects in IPF AEC2s, due to loss of Napsin A, resulting in increased intra-alveolar surface tension and alveolar collapse and induction of endoplasmic reticulum stress in AEC2s. In vivo pharmacological inhibition of Napsin A results in the development of AEC2 injury and overt lung fibrosis. We also demonstrate that Notch1 signaling is already activated early in IPF and determines AEC2 fate by inhibiting differentiation (reduced lamellar body compartment, reduced capacity to process hydrophobic SP) and by causing increased epithelial proliferation and development of lung fibrosis, putatively via altered JAK (Janus kinase)/Stat (signal transducer and activator of transcription) signaling in AEC2s. Conversely, inhibition of Notch signaling in IPF-derived precision-cut lung slices improved the surfactant processing capacity of AEC2s and reversed fibrosis. Conclusions: Notch1 is a central regulator of AEC2 fate in IPF. It induces alveolar epithelial proliferation and loss of Napsin A and of surfactant proprotein processing, and it contributes to fibroproliferation.

A hallmark of acute respiratory distress syndrome (ARDS) is an accumulation of protein-rich alveolar edema that impairs gas exchange and leads to worse outcomes. Thus, understanding the mechanisms of alveolar albumin clearance is of high clinical relevance. Here, we investigated the mechanisms of the cellular albumin uptake in a three-dimensional culture of precision-cut lung slices (PCLS). We found that up to 60% of PCLS cells incorporated labeled albumin in a time- and concentration-dependent manner, whereas virtually no uptake of labeled dextran was observed. Of note, at a low temperature (4 °C), saturating albumin receptors with unlabeled albumin and an inhibition of clathrin-mediated endocytosis markedly decreased the endocytic uptake of the labeled protein, implicating a receptor-driven internalization process. Importantly, uptake rates of albumin were comparable in alveolar epithelial type I (ATI) and type II (ATII) cells, as assessed in PCLS from a SftpcCre ERT2/+ : tdTomato flox/flox mouse strain (defined as EpCAM + CD31 - CD45 - tdTomatoSPC - T1α + for ATI and EpCAM + CD31 - CD45 - tdTomatoSPC + T1α - for ATII cells). Once internalized, albumin was found in the early and recycling endosomes of the alveolar epithelium as well as in endothelial, mesenchymal, and hematopoietic cell populations, which might indicate transcytosis of the protein. In summary, we characterize albumin uptake in alveolar epithelial cells in the complex setting of PCLS. These findings may open new possibilities for pulmonary drug delivery that may improve the outcomes for patients with respiratory failure.

Background: Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide. In addition to chronic bronchitis and emphysema, patients often develop at least mild pulmonary hypertension (PH). We previously demonstrated that inhibition of inducible nitric oxide synthase (iNOS) prevents and reverses emphysema and PH in mice. Interestingly, strong iNOS upregulation was found in alveolar epithelial type II cells (AECII) in emphysematous murine lungs, and peroxynitrite, which can be formed from iNOS-derived NO, was shown to induce AECII apoptosis in vitro. However, the specific cell type(s) that drive(s) iNOS-dependent lung regeneration in emphysema/PH has (have) not been identified yet., Aim: we tested whether iNOS knockout in AECII affects established elastase-induced emphysema in mice., Methods: four weeks after a single intratracheal instillation of porcine pancreatic elastase for the induction of emphysema and PH, we induced iNOS knockout in AECII in mice, and gave an additional twelve weeks for the potential recovery., Results: iNOS knockout in AECII did not reduce elastase-induced functional and structural lung changes such as increased lung compliance, decreased mean linear intercept and increased airspace, decreased right ventricular function, increased right ventricular systolic pressure and increased pulmonary vascular muscularization. In vitro, iNOS inhibition did not reduce apoptosis of AECII following exposure to a noxious stimulus., Conclusion: taken together, our data demonstrate that iNOS deletion in AECII is not sufficient for the regeneration of emphysematous murine lungs, and suggest that iNOS expression in pulmonary vascular or stromal cells might be critically important in this regard.

Shedding of hyaluronan (HA), the component of endothelial cell (EC) glycocalyx, has been associated with acute lung injury. HA degradation allows plasma proteins and fluid to penetrate across the vascular wall leading to lung edema formation and leukocyte recruitment. Here, we analyzed sHA levels and size in patients with community-acquired pneumonia (CAP) and acute respiratory distress syndrome (ARDS), correlated them to disease severity, and evaluated the impact of pneumolysin (PLY), the Streptococcus pneumoniae (S.p.) exotoxin, on HA shedding from human pulmonary microvascular EC (HPMVEC). sHA levels were elevated in CAP and ARDS and correlated with the CRB65 severity score and with markers of inflammation (interleukin-6), EC activation (E-selectin), and basement membrane destruction (collagen IV). Furthermore, sHA levels were associated with an increase in 28-day mortality. Small and large sHA fragments were detected in plasma of most severe CAP or ARDS patients, and the presence of large sHA fragments was accompanied by the elevated levels of circulating collagen IV. In vitro, PLY induced sHA release from HPMVEC. This effect was dependent on reactive oxygen species (ROS) production and was not associated with endothelial barrier dysfunction. Conversely, HA shedding was impaired following HPMVEC infection with a S.p. PLY-deficient mutant. Our study identifies association between the severity of CAP and ARDS and the levels and size of sHA in plasma. It links sHA levels with, inflammation, EC activation status and basement membrane disassembly in ARDS and provides insights into the mechanism of HA shedding during infection., Competing Interests: Declaration of competing interest None, (Copyright © 2022 Elsevier B.V. All rights reserved.)

Background: This study analyzed the utility of soluble ST2 (sST2) and GDF-15 as biomarkers of right ventricular (RV) function in patients with pulmonary hypertension (PH). Methods: GDF-15 and sST2 serum concentrations were measured in patients with PH (n = 628), dilated cardiomyopathy (n = 31) and left ventricular hypertrophy (n = 47), and in healthy controls (n = 61). Results: Median sST2 and GDF-15 levels in patients with left ventricular hypertrophy were higher than in patients with PH and dilated cardiomyopathy. In tertile analysis GDF-15 >1363 pg/ml and sST2 >38 ng/ml were associated with higher N-terminal pro-brain natriuretic peptide, RV systolic dysfunction, RV-pulmonary arterial uncoupling and hemodynamic impairment. Conclusion: GDF-15 and sST2 are potential biomarkers of RV dysfunction in patients with PH.

Repair-supportive mesenchymal cells (RSMCs) have been recently reported in the context of naphthalene (NA)-induced airway injury and regeneration. These cells transiently express smooth muscle actin (Acta2) and are enriched with platelet-derived growth factor receptor alpha (Pdgfra) and fibroblast growth factor 10 (Fgf10) expression. Genetic deletion of Ctnnb1 (gene coding for beta catenin) or Fgf10 in these cells using the Acta2-Cre-ERT2 driver line after injury (defined as NA-Tam condition; Tam refers to tamoxifen) led to impaired repair of the airway epithelium. In this study, we demonstrate that RSMCs are mostly captured using the Acta2-Cre-ERT2 driver when labeling occurs after (NA-Tam condition) rather than before injury (Tam-NA condition), and that their expansion occurs mostly between days 3 and 7 following NA treatment. Previous studies have shown that lineage-traced peribronchial GLI1+ cells are transiently amplified after NA injury. Here, we report that Gli1 expression is enriched in RSMCs. Using lineage tracing with Gli1 Cre-ERT2 mice combined with genetic inactivation of Fgf10, we show that GLI1+ cells with Fgf10 deletion fail to amplify around the injured airways, thus resulting in impaired airway epithelial repair. Interestingly, Fgf10 expression is not upregulated in GLI1+ cells following NA treatment, suggesting that epithelial repair is mostly due to the increased number of Fgf10-expressing GLI1+ cells. Co-culture of SCGB1A1+ cells with GLI1+ cells isolated from non-injured or injured lungs showed that GLI1+ cells from these two conditions are similarly capable of supporting bronchiolar organoid (or bronchiolosphere) formation. Single-cell RNA sequencing on sorted lineage-labeled cells showed that the RSMC signature resembles that of alveolar fibroblasts. Altogether, our study provides strong evidence for the involvement of mesenchymal progenitors in airway epithelial regeneration and highlights the critical role played by Fgf10-expressing GLI1+ cells in this context., (© 2022. The Author(s).)