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Oxygen toxicity constitutes a key contributor to bronchopulmonary dysplasia (BPD). Critical step in the pathogenesis of BPD is the inflammatory response in the immature lung with the release of pro-inflammatory cytokines and the influx of innate immune cells. Identification of efficient therapies to alleviate the inflammatory response remains an unmet research priority. First, we studied macrophage and neutrophil profiles in tracheal aspirates of n = 103 preterm infants <29 weeks´ gestation requiring mechanical ventilation. While no differences were present at birth, a higher fraction of macrophages, the predominance of the CD14+CD16+ subtype on day 5 of life was associated with moderate/severe BPD. Newborn CCL-2-/- mice insufficient in pulmonary macrophage recruitment had a reduced influx of neutrophils, lower apoptosis induction in the pulmonary tissue and better-preserved lung morphometry with higher counts of type II cells, mesenchymal stem cells and vascular endothelial cells when exposed to hyperoxia for 7 days. To study the benefit of a targeted approach to prevent the pulmonary influx of macrophages, wildtype mice were repeatedly treated with CCL-2 blocking antibodies while exposed to hyperoxia for 7 days. Congruent with the results in CCL-2-/- animals, the therapeutic intervention reduced the pulmonary inflammatory response, attenuated cell death in the lung tissue and better-preserved lung morphometry. Overall, our preclinical and clinical datasets document the predominant role of macrophage recruitment to the pathogenesis of BPD and establish the abrogation of CCL-2 function as novel approach to protect the immature lung from hyperoxic injury.
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Background: Myofibroblasts (MYFs) are generally considered the principal culprits in excessive extracellular matrix deposition and scar formation in the pathogenesis of lung fibrosis. Lipofibroblasts (LIFs), on the other hand, are defined by their lipid-storing capacity and are predominantly found in the alveolar regions of the lung. They have been proposed to play a protective role in lung fibrosis. We previously reported that a LIF to MYF reversible differentiation switch occurred during fibrosis formation and resolution. In this study, we tested whether WI-38 cells, a human embryonic lung fibroblast cell line, could be used to study fibroblast differentiation towards the LIF or MYF phenotype and whether this could be relevant for idiopathic pulmonary fibrosis (IPF). Methods: Using WI-38 cells, Fibroblast (FIB) to MYF differentiation was triggered using TGF-ß1 treatment and FIB to LIF differentiation using Metformin treatment. We also analyzed the MYF to LIF and LIF to MYF differentiation by pre-treating the WI-38 cells with TGF-ß1 or Metformin respectively. We used IF, qPCR and bulk RNA-Seq to analyze the phenotypic and transcriptomic changes in the cells. We correlated our in vitro transcriptome data from WI-38 cells (obtained via bulk RNA sequencing) with the transcriptomic signature of LIFs and MYFs derived from the IPF cell atlas as well as with our own single-cell transcriptomic data from IPF patients-derived lung fibroblasts (LF-IPF) cultured in vitro. We also carried out alveolosphere assays to evaluate the ability of the proposed LIF and MYF cells to support the growth of alveolar epithelial type 2 cells. Results: WI-38 cells and LF-IPF display similar phenotypical and gene expression responses to TGF-ß1 and Metformin treatment. Bulk RNA-Seq analysis of WI-38 cells and LF-IPF treated with TGF-ß1, or Metformin indicate similar transcriptomic changes. We also show the partial conservation of the LIF and MYF signature extracted from the Habermann et al. scRNA-seq dataset in WI-38 cells treated with Metformin or TGF-ß1, respectively. Alveolosphere assays indicate that LIFs enhance organoid growth, while MYFs inhibit organoid growth. Finally, we provide evidence supporting the MYF to LIF and LIF to MYF reversible switch using WI-38 cells. Conclusions: WI-38 cells represent a versatile and reliable model to study the intricate dynamics of fibroblast differentiation towards the MYF or LIF phenotype associated with lung fibrosis formation and resolution, providing valuable insights to drive future research.
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Diferenciação Celular , Fibroblastos , Fibrose Pulmonar Idiopática , Miofibroblastos , Fator de Crescimento Transformador beta1 , Humanos , Miofibroblastos/metabolismo , Fibroblastos/metabolismo , Linhagem Celular , Fibrose Pulmonar Idiopática/patologia , Fibrose Pulmonar Idiopática/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Fator de Crescimento Transformador beta1/genética , Pulmão/patologia , Pulmão/citologia , Transcriptoma , Metformina/farmacologia , Plasticidade Celular/efeitos dos fármacos , FenótipoRESUMO
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: Gli1Cre-ERT2; tdTomatoflox 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 Acta2high 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.
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Hipertensão Pulmonar , Remodelação Vascular , Proteína GLI1 em Dedos de Zinco , Animais , Proteína GLI1 em Dedos de Zinco/metabolismo , Proteína GLI1 em Dedos de Zinco/genética , Camundongos , Hipertensão Pulmonar/metabolismo , Hipertensão Pulmonar/fisiopatologia , Hipertensão Pulmonar/patologia , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/patologia , Miócitos de Músculo Liso/metabolismo , Miócitos de Músculo Liso/patologia , Camundongos Endogâmicos C57BL , Artéria Pulmonar/metabolismo , Artéria Pulmonar/patologia , Artéria Pulmonar/fisiopatologia , Camundongos Transgênicos , Masculino , Humanos , Hipóxia/metabolismo , Hipóxia/fisiopatologiaAssuntos
Vacina BNT162 , COVID-19 , Humanos , Criança , Pré-Escolar , Vacinas contra COVID-19 , COVID-19/prevenção & controleRESUMO
Bronchopulmonary dysplasia (BPD) is a chronic lung disease commonly seen in preterm infants, and is triggered by infection, mechanical ventilation, and oxygen toxicity. Among other problems, lifelong limitations in lung function and impaired psychomotor development may result. Despite major advances in understanding the disease pathologies, successful interventions are still limited to only a few drug therapies with a restricted therapeutic benefit, and which sometimes have significant side effects. As a more promising therapeutic option, mesenchymal stem cells (MSCs) have been in focus for several years due to their anti-inflammatory effects and their secretion of growth and development promoting factors. Preclinical studies provide evidence in that MSCs have the potential to contribute to the repair of lung injuries. This review provides an overview of MSCs, and other stem/progenitor cells present in the lung, their identifying characteristics, and their differentiation potential, including cytokine/growth factor involvement. Furthermore, animal studies and clinical trials using stem cells or their secretome are reviewed. To bring MSC-based therapeutic options further to clinical use, standardized protocols are needed, and upcoming side effects must be critically evaluated. To fill these gaps of knowledge, the MSCs' behavior and the effects of their secretome have to be examined in more (pre-) clinical studies, from which only few have been designed to date.
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Displasia Broncopulmonar , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Recém-Nascido , Animais , Humanos , Displasia Broncopulmonar/terapia , Displasia Broncopulmonar/patologia , Recém-Nascido Prematuro , Pulmão/patologia , Células-Tronco/patologia , Células-Tronco Mesenquimais/patologia , Transplante de Células-Tronco Mesenquimais/métodosRESUMO
Childhood interstitial lung disease (chILD) is a collective term for a group of rare lung disorders of heterogeneous origin. Surfactant dysfunction disorders are a cause of chILD with onset during the neonatal period and infancy. Clinical signs of tachypnea and hypoxemia are nonspecific and usually caused by common conditions like lower respiratory tract infections. We report on a full-term male newborn who was readmitted to the hospital at 7 days of age with marked tachypnea and poor feeding during the respiratory syncytial virus season. After exclusion of infection and other, more common congenital disorders, chILD was diagnosed using chest computed tomography and genetic analysis. A likely pathogenic heterozygous variant of SFTPC (c.163C>T, L55F) was detected by whole exome sequencing. The patient received supplemental oxygen and noninvasive respiratory support and was treated with intravenous methylprednisolone pulses and hydroxychloroquine. Despite the treatment, his respiratory situation deteriorated continuously, leading to several hospitalizations and continuous escalation of noninvasive ventilatory support. At 6 months of age, the patient was listed for lung transplant and transplanted successfully aged 7 months.
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Doenças Pulmonares Intersticiais , Proteína C , Humanos , Lactente , Recém-Nascido , Masculino , Doenças Pulmonares Intersticiais/diagnóstico , Doenças Pulmonares Intersticiais/genética , Doenças Pulmonares Intersticiais/terapia , Mutação , Proteína C/genética , Proteína C/uso terapêutico , Proteína C Associada a Surfactante Pulmonar/genética , Proteína C Associada a Surfactante Pulmonar/uso terapêutico , Tensoativos , TaquipneiaRESUMO
PURPOSE: SARS-CoV-2 infections cause COVID-19 and have a wide spectrum of morbidity. Severe disease courses among children are rare. To date, data on the variability of morbidity in relation to variant of concern (VOC) in children has been sparse and inconclusive. We compare the clinical severity of SARS-CoV-2 infection among children and adolescents in Germany during the Wildtype and Alpha combined, Delta and Omicron phases of the COVID-19 pandemic. METHODS: Comparing risk of COVID-19-related hospitalization, intensive care unit (ICU) admission and death due to COVID-19 in children and adolescents, we used: (1) a multi-center seroprevalence study (SARS-CoV-2-KIDS study); (2) a nationwide registry of pediatric patients hospitalized with SARS-CoV-2 infections; and (3) compulsory national reporting for RT-PCR-confirmed SARS-CoV-2 infections in Germany. RESULTS: During the Delta predominant phase, risk of COVID-19-related hospitalization among all SARS-CoV-2 seropositive children was 3.35, ICU admission 1.19 and fatality 0.09 per 10,000; hence about halved for hospitalization and ICU admission and unchanged for deaths as compared to the Wildtype- and Alpha-dominant period. The relative risk for COVID-19-related hospitalization and ICU admission compared to the alpha period decreased during Delta [0.60 (95% CI 0.54; 0.67) and 0.51 (95% CI 0.42; 0.61)] and Omicron [0.27 (95% CI 0.24; 0.30) and 0.06 (95% CI 0.05; 0.08)] period except for the < 5-year-olds. The rate of case fatalities decreased slightly during Delta, and substantially during Omicron phase. CONCLUSION: Morbidity caused by SARS-CoV-2 infections among children and adolescents in Germany decreased over the course of the COVID-19 pandemic, as different VOCs) emerged.
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COVID-19 , SARS-CoV-2 , Humanos , Adolescente , Criança , Pré-Escolar , COVID-19/epidemiologia , Risco , Pandemias , Estudos Soroepidemiológicos , Hospitalização , Alemanha/epidemiologia , Unidades de Terapia IntensivaRESUMO
The specification, characterization, and fate of alveolar type 1 and type 2 (AT1 and AT2) progenitors during embryonic lung development are poorly defined. Current models of distal epithelial lineage formation fail to capture the heterogeneity and dynamic contribution of progenitor pools present during early development. Furthermore, few studies explore the pathways involved in alveolar progenitor specification and fate. In this paper, we build upon our previously published work on the regulation of airway epithelial progenitors by fibroblast growth factor receptor 2b (FGFR2b) signalling during early (E12.5) and mid (E14.5) pseudoglandular stage lung development. Our results suggest that a significant proportion of AT2 and AT1 progenitors are lineage-flexible during late pseudoglandular stage development, and that lineage commitment is regulated in part by FGFR2b signalling. We have characterized a set of direct FGFR2b targets at E16.5 which are likely involved in alveolar lineage formation. These signature genes converge on a subpopulation of AT2 cells later in development and are downregulated in AT2 cells transitioning to the AT1 lineage during repair after injury in adults. Our findings highlight the extensive heterogeneity of pneumocytes by elucidating the role of FGFR2b signalling in these cells during early airway epithelial lineage formation, as well as during repair after injury.
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Células Epiteliais Alveolares , Pulmão , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos , Células-Tronco , Animais , Camundongos , Desenvolvimento Embrionário , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/genética , Transdução de Sinais , Pulmão/embriologia , Linhagem da CélulaRESUMO
Importance: SARS-CoV-2 vaccines are authorized for use in most age groups. The safety of SARS-CoV-2 vaccines is unknown in children younger than 5 years. Objective: To retrospectively evaluate the safety of the BNT162b2 vaccine used off-label in children younger than 5 years compared with the safety of non-SARS-CoV-2 vaccines in the same sample. Design, Setting, and Participants: This investigator-initiated retrospective cohort study included parents or caregivers who registered children for SARS-CoV-2 vaccination in outpatient care facilities in Germany. The study was performed as an authenticated online survey. A total of 19â¯000 email addresses were contacted from vaccination registration databases between April 14 and May 9, 2022. Inclusion criteria were child age younger than 5 years at the first BNT162b2 vaccination and use of a correct authentication code to prove invitation. Exposures: Off-label BNT162b2 vaccination and on-label non-SARS-CoV-2 vaccinations. Main Outcomes and Measures: Reported short-term safety data of 1 to 3 doses of 3 to 10 µg BNT162b2 in children from birth to younger than 60 months are presented. Coprimary outcomes were the frequencies of 11 categories of symptoms after vaccination with bivariate analyses and regression models adjusting for age, sex, weight, and height. Results: The study included 7806 children (median age, 3 years [IQR, 2-4 years]; 3824 [49.0%] female) who were followed up of for a mean (SD) of 91.4 (38.8) days since first BNT162b2 vaccination (survey response rate, 41.1%). A 10-µg dosage was more frequently associated with local injection-site symptoms compared with lower dosages. In the active-comparator analysis, the probability of any symptoms (odds ratio [OR], 1.62; 95% CI, 1.43-1.84), local symptoms (OR, 1.68; 95% CI, 1.38-2.05), musculoskeletal symptoms (OR, 2.55; 95% CI, 1.32-4.94), dermatologic symptoms (OR, 2.18; 95% CI, 10.7-4.45), or otolaryngologic symptoms (OR, 6.37; 95% CI, 1.50-27.09) were modestly elevated after BNT162b2 compared with non-SARS-CoV-2 vaccines, whereas the probabilities of general symptoms (OR, 0.77; 95% CI, 0.63-0.95) and fever (OR, 0.42; 95% CI, 0.32-0.55) were lower after BNT162b2. Symptoms requiring hospitalization (n = 10) were reported only at BNT162b2 dosages above 3 µg. Conclusions and Relevance: In this cohort study, the symptoms reported after BNT162b2 administration were comparable overall to those for on-label non-SARS-CoV-2 vaccines in this cohort of children younger than 5 years. The present data may be used together with prospective licensure studies of BNT162b2 efficacy and safety and could help guide expert recommendations about BNT162b2 vaccinations in this age group.
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Vacinas contra COVID-19 , COVID-19 , Vacinas , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Vacina BNT162 , Estudos de Coortes , COVID-19/prevenção & controle , Vacinas contra COVID-19/efeitos adversos , Estudos Prospectivos , Estudos Retrospectivos , RNA Mensageiro , SARS-CoV-2RESUMO
Insulin receptor substrates (IRSs) are proteins that are involved in signaling through the insulin receptor (IR) and insulin-like growth factor (IGFR). They can also interact with other receptors including growth factor receptors. Thus, they represent a critical node for the transduction and regulation of multiple signaling pathways in response to extracellular stimuli. In addition, IRSs play a central role in processes such as inflammation, growth, metabolism, and proliferation. Previous studies have highlighted the role of IRS proteins in lung diseases, in particular asthma. Further, the members of the IRS family are the common proteins of the insulin growth factor signaling cascade involved in lung development and disrupted in bronchopulmonary dysplasia (BPD). However, there is no study focusing on the relationship between IRS proteins and BPD yet. Unfortunately, there is still a significant gap in knowledge in this field. Thus, in this review, we aimed to summarize the current knowledge with the major goal of exploring the possible roles of IRS in BPD and asthma to foster new perspectives for further investigations.
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Asma , Displasia Broncopulmonar , Humanos , Recém-Nascido , Insulina/metabolismo , Proteínas Substratos do Receptor de Insulina/metabolismo , Fosfoproteínas/metabolismo , Receptor de Insulina/metabolismoRESUMO
The hyperoxia-induced pro-inflammatory response and tissue damage constitute pivotal steps leading to bronchopulmonary dysplasia (BPD) in the immature lung. The pro-inflammatory cytokines are considered attractive candidates for a directed intervention but the complex interplay between inflammatory and developmental signaling pathways requires a comprehensive evaluation before introduction into clinical trials as studied here for the death inducing ligand TRAIL. At birth and during prolonged exposure to oxygen and mechanical ventilation, levels of TRAIL were lower in tracheal aspirates of preterm infants <29 weeks of gestation which developed moderate/severe BPD. These findings were reproduced in the newborn mouse model of hyperoxic injury. The loss of TRAIL was associated with increased inflammation, apoptosis induction and more pronounced lung structural simplification after hyperoxia exposure for 7 days while activation of NFκB signaling during exposure to hyperoxia was abrogated. Pretreatment with recombinant TRAIL rescued the developmental distortions in precision cut lung slices of both wildtype and TRAIL-/- mice exposed to hyperoxia. Of importance, TRAIL preserved alveolar type II cells, mesenchymal progenitor cells and vascular endothelial cells. In the situation of TRAIL depletion, our data ascribe oxygen toxicity a more injurious impact on structural lung development. These data are not surprising taking into account the diverse functions of TRAIL and its stimulatory effects on NFκB signaling as central driver of survival and development. TRAIL exerts a protective role in the immature lung as observed for the death inducing ligand TNF-α before.
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Displasia Broncopulmonar , Hiperóxia , Ligante Indutor de Apoptose Relacionado a TNF , Animais , Animais Recém-Nascidos , Displasia Broncopulmonar/metabolismo , Células Endoteliais/metabolismo , Humanos , Hiperóxia/complicações , Hiperóxia/genética , Hiperóxia/metabolismo , Recém-Nascido , Recém-Nascido Prematuro , Ligantes , Pulmão/metabolismo , Camundongos , NF-kappa B/metabolismo , Oxigênio/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF/química , Ligante Indutor de Apoptose Relacionado a TNF/metabolismoRESUMO
Pulmonary manifestation (PM) of inflammatory bowel disease (IBD) in children is a rare condition. The exact pathogenesis is still unclear, but several explanatory concepts were postulated and several case reports in children were published. We performed a systematic Medline search between April 1976 and April 2022. Different pathophysiological concepts were identified, including the shared embryological origin, "miss-homing" of intestinal based neutrophils and T lymphocytes, inflammatory triggering via certain molecules (tripeptide proline-glycine-proline, interleukin 25), genetic factors and alterations in the microbiome. Most pediatric IBD patients with PM are asymptomatic, but can show alterations in pulmonary function tests and breathing tests. In children, the pulmonary parenchyma is more affected than the airways, leading histologically mainly to organizing pneumonia. Medication-associated lung injury has to be considered in pulmonary symptomatic pediatric IBD patients treated with certain agents (i.e., mesalamine, sulfasalazine or infliximab). Furthermore, the risk of pulmonary embolism is generally increased in pediatric IBD patients. The initial treatment of PM is based on corticosteroids, either inhaled for the larger airways or systemic for smaller airways and parenchymal disease. In summary, this review article summarizes the current knowledge about PM in pediatric IBD patients, focusing on pathophysiological and clinical aspects.
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Doenças Inflamatórias Intestinais , Criança , Humanos , Doenças Inflamatórias Intestinais/complicações , Doenças Inflamatórias Intestinais/diagnóstico , Infliximab/uso terapêutico , Pulmão , Mesalamina , ProlinaRESUMO
The rate of SARS-CoV-2 infections in children remains unclear due to many asymptomatic cases. We present a study of cross-sectional seroprevalence surveys of anti-SARS-CoV-2 IgG in 10,358 children recruited in paediatric hospitals across Germany from June 2020 to May 2021. Seropositivity increased from 2.0% (95% CI 1.6, 2.5) to 10.8% (95% CI 8.7, 12.9) in March 2021 with little change up to May 2021. Rates increased by migrant background (2.8%, 4.4% and 7.8% for no, one and two parents born outside Germany). Children under three were initially 3.6 (95% CI 2.3, 5.7) times more likely to be seropositive with levels equalising later. The ratio of seropositive cases per recalled infection decreased from 8.6 to 2.8. Since seropositivity exceeds the rate of recalled infections considerably, serologic testing may provide a more valid estimate of infections, which is required to assess both the spread and the risk for severe outcomes of SARS-CoV-2 infections.
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COVID-19 , SARS-CoV-2 , Anticorpos Antivirais , COVID-19/epidemiologia , Criança , Estudos Transversais , Alemanha/epidemiologia , Humanos , Estudos SoroepidemiológicosRESUMO
The intestinal microbiota is known to influence local immune homeostasis in the gut and to shape the developing immune system towards elimination of pathogens and tolerance towards self-antigens. Even though the lung was considered sterile for a long time, recent evidence using next-generation sequencing techniques confirmed that the lower airways possess their own local microbiota. Since then, there has been growing evidence that the local respiratory and intestinal microbiota play a role in acute and chronic pediatric lung diseases. The concept of the so-called gut-lung axis describing the mutual influence of local microbiota on distal immune mechanisms was established. The mechanisms by which the intestinal microbiota modulates the systemic immune response include the production of short-chain fatty acids (SCFA) and signaling through pattern recognition receptors (PRR) and segmented filamentous bacteria. Those factors influence the secretion of pro- and anti-inflammatory cytokines by immune cells and further modulate differentiation and recruitment of T cells to the lung. This article does not only aim at reviewing recent mechanistic evidence from animal studies regarding the gut-lung axis, but also summarizes current knowledge from observational studies and human trials investigating the role of the respiratory and intestinal microbiota and their modulation by pre-, pro-, and synbiotics in pediatric lung diseases.
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Microbioma Gastrointestinal , Pneumopatias , Microbiota , Animais , Criança , Ácidos Graxos Voláteis , Microbioma Gastrointestinal/fisiologia , Humanos , PulmãoRESUMO
Bronchopulmonary dysplasia (BPD) is a neonatal lung disease developing in premature babies characterized by arrested alveologenesis and associated with decreased Fibroblast growth factor 10 (FGF10) expression. One-week hyperoxia (HYX) exposure of newborn mice leads to a permanent arrest in alveologenesis. To test the role of Fgf10 signaling to promote de novo alveologenesis following hyperoxia, we used transgenic mice allowing inducible expression of Fgf10 and recombinant FGF10 (rFGF10) protein delivered intraperitoneally. We carried out morphometry analysis, and IF on day 45. Alveolospheres assays were performed co-culturing AT2s from normoxia (NOX) with FACS-isolated Sca1Pos resident mesenchymal cells (rMC) from animals exposed to NOX, HYX-PBS, or HYX-FGF10. scRNAseq between rMC-Sca1Pos isolated from NOX and HYX-PBS was also carried out. Transgenic overexpression of Fgf10 and rFGF10 administration rescued the alveologenesis defects following HYX. Alveolosphere assays indicate that the activity of rMC-Sca1Pos is negatively impacted by HYX and partially rescued by rFGF10 treatment. Analysis by IF demonstrates a significant impact of rFGF10 on the activity of resident mesenchymal cells. scRNAseq results identified clusters expressing Fgf10, Fgf7, Pdgfra, and Axin2, which could represent the rMC niche cells for the AT2 stem cells. In conclusion, we demonstrate that rFGF10 administration is able to induce de novo alveologenesis in a BPD mouse model and identified subpopulations of rMC-Sca1Pos niche cells potentially representing its cellular target.
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Displasia Broncopulmonar , Hiperóxia , Animais , Animais Recém-Nascidos , Displasia Broncopulmonar/genética , Displasia Broncopulmonar/metabolismo , Fator 10 de Crescimento de Fibroblastos/genética , Fator 10 de Crescimento de Fibroblastos/metabolismo , Humanos , Hiperóxia/metabolismo , Recém-Nascido , Pulmão/metabolismo , Camundongos , Camundongos TransgênicosRESUMO
BACKGROUND: Worldwide, alcohol-related road traffic accidents represent a major avoidable health risk. The aim of this study was to evaluate the accuracy of self-estimating the degree of acute alcohol intoxication regarding the legal driving limit, and to identify risk factors for misjudgement. METHODS: In this prospective randomised controlled crossover trial, 90 social drinkers (mean age 23.9 ± 3.5 years, 50% female) consumed either beer or wine. Study group subjects were made aware when exceeding the legal driving limit (BrAC = 0.05%). Controls received no information about their BrAC. For crossover, beer or wine were consumed in the opposite order. RESULTS: 39-53% of all participants exceeded the legal driving limit whilst under the impression to be still permitted to drive. Self-estimation was significantly more accurate on study day 2 (p = 0.009). Increasing BrAC positively correlated with self-estimation inaccuracy, which was reproducible during crossover. Multiple regression analysis revealed fast drinking and higher alcohol levels as independent risk factors for inaccurate self-estimation. CONCLUSIONS: Social drinkers are commonly unaware of exceeding the legal driving limit when consuming alcohol. Self-estimating alcohol intoxication can be improved through awareness. Dedicated awareness programs, social media campaigns and government advice communications should be utilised to address this avoidable hazard. Trial registration The trial was registered prospectively at the Witten/Herdecke University Ethics Committee (trial registration number 140/2016 on 04/11/2016) and at the DRKS-German Clinical Trials Register (trial registration number DRKS00015285 on 08/22/2018-Retrospectively registered). Trial protocol can be accessed online.
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Intoxicação Alcoólica , Condução de Veículo , Adulto , Consumo de Bebidas Alcoólicas , Feminino , Humanos , Masculino , Percepção , Estudos Prospectivos , Adulto JovemRESUMO
In addition to nucleosomes, chromatin contains non-histone chromatin-associated proteins, of which the high-mobility group proteins are the most abundant. Chromatin-mediated regulation of transcription involves DNA methylation and histone modifications. However, the order of events and the precise function of high-mobility group proteins during transcription initiation remain unclear. Here we show that high-mobility group AT-hook 2 protein (HMGA2) induces DNA nicks at the transcription start site, which are required by the histone chaperone FACT complex to incorporate nucleosomes containing the histone variant H2A.X. Further, phosphorylation of H2A.X at S139 (γ-H2AX) is required for repair-mediated DNA demethylation and transcription activation. The relevance of these findings is demonstrated within the context of TGFB1 signaling and idiopathic pulmonary fibrosis, suggesting therapies against this lethal disease. Our data support the concept that chromatin opening during transcriptional initiation involves intermediates with DNA breaks that subsequently require DNA repair mechanisms to ensure genome integrity.
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Desmetilação do DNA , Nucleossomos/metabolismo , Iniciação da Transcrição Genética , Animais , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Cromatina/química , Cromatina/metabolismo , Células HEK293 , Proteína HMGA2/metabolismo , Histonas/metabolismo , Humanos , Fibrose Pulmonar Idiopática/genética , Fibrose Pulmonar Idiopática/patologia , Camundongos , Fosforilação , Fosfosserina/metabolismo , RNA Polimerase II/metabolismo , Sítio de Iniciação de Transcrição , Ativação Transcricional/genética , Fator de Crescimento Transformador beta1/metabolismoRESUMO
Bronchopulmonary dysplasia (BPD) remains one of the most devastating consequences of preterm birth resulting in life-long restrictions in lung function. Distorted lung development is caused by its inflammatory response which is mainly provoked by mechanical ventilation, oxygen toxicity and bacterial infections. Dysfunction of resident lung mesenchymal stem cells (MSC) represents one key hallmark that drives BPD pathology. Despite all progress in the understanding of pathomechanisms, therapeutics to prevent or treat BPD are to date restricted to a few drugs. The limited therapeutic efficacy of established drugs can be explained by the fact that they fail to concurrently tackle the broad spectrum of disease driving mechanisms and by the huge overlap between distorted signal pathways of lung development and inflammation. The great enthusiasm about MSC based therapies as novel therapeutic for BPD arises from the capacity to inhibit inflammation while simultaneously promoting lung development and repair. Preclinical studies, mainly performed in rodents, raise hopes that there will be finally a broadly acting, efficient therapy at hand to prevent or treat BPD. Our narrative review gives a comprehensive overview on preclinical achievements, results from first early phase clinical studies and challenges to a successful translation into the clinical setting.
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Displasia Broncopulmonar/terapia , Transplante de Células-Tronco Mesenquimais , Displasia Broncopulmonar/prevenção & controle , Humanos , PulmãoRESUMO
More than 50 years after the first description of Bronchopulmonary dysplasia (BPD) by Northway, this chronic lung disease affecting many preterm infants is still poorly understood. Additonally, approximately 40% of preterm infants suffering from severe BPD also suffer from Bronchopulmonary dysplasia-associated pulmonary hypertension (BPD-PH), leading to a significant increase in total morbidity and mortality. Until today, there is no curative therapy for both BPD and BPD-PH available. It has become increasingly evident that growth factors are playing a central role in normal and pathologic development of the pulmonary vasculature. Thus, this review aims to summarize the recent evidence in our understanding of BPD-PH from a basic scientific point of view, focusing on the potential role of Fibroblast Growth Factor (FGF)/FGF10 signaling pathway contributing to disease development, progression and resolution.