51
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Cavallaro EC, Liang KK, Lawrence MD, Forsyth KD, Dixon DL. Neutrophil infiltration and activation in bronchiolitic airways are independent of viral etiology. Pediatr Pulmonol 2017; 52:238-246. [PMID: 27410761 DOI: 10.1002/ppul.23514] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 06/02/2016] [Accepted: 06/05/2016] [Indexed: 12/23/2022]
Abstract
BACKGROUND Hospitalization with bronchiolitis is linked to the development of early childhood chronic wheeze and asthma. Viral etiology and severity of inflammation are potential contributing factors. Previously we observed reduced airway neutrophil infiltration in breastfed bronchiolitic infants, with a corresponding reduction in disease severity. This study aimed to examine whether respiratory viral etiology and co-infection alters the pattern of neutrophil influx, and the inflammatory mediator profile, resulting in epithelial damage in bronchiolitis. METHODS Nasopharyngeal aspirates (NPAs) collected from hospitalized infants were assessed for viruses, soluble protein, cellular infiltrate, interleukin (IL)-6, -8, and myeloperoxidase (MPO). RESULTS NPAs were collected from 228 bronchiolitic and 14 non-bronchiolitic infants. In the bronchiolitic cohort, human rhinovirus was most prevalent (38%), followed by respiratory syncytial virus (36%), adenovirus (10%), and human metapneumovirus (6%), with 25% positive for viral co-infections and 25% negative for all screened viruses. Viral-induced bronchiolitis was associated with increased cellular infiltrate and protein, above control, and virus-negative infants (P < 0.05). Cellular infiltrate correlated to IL-6, -8, and MPO (r = 0.331, 0.669, and 0.661; P < 0.01). Protein, IL-6, -8, and MPO differed significantly between viral groups; however, the majority of marker values for all groups fall within an overlapping, indistinguishable range, precluding their use as biomarkers of viral etiology. No significant difference was found between single and viral co-infections for any parameter. CONCLUSION Bronchiolitic infants presenting with a detectable respiratory virus during hospitalization demonstrated elevated markers of airway tissue inflammation and injury. In this cohort, viral etiology did not discernibly modulate chemokine-mediated neutrophil infiltration and activation. Pediatr Pulmonol. 2017;52:238-246. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
| | - Kar-Kate Liang
- Department of Critical Care Medicine, Adelaide, Australia
| | | | - Kevin D Forsyth
- Department of Paediatrics and Child Health, Flinders University, Adelaide, Australia
| | - Dani-Louise Dixon
- Department of Critical Care Medicine, Adelaide, Australia.,Intensive and Critical Care Unit, Flinders Medical Centre, Adelaide, Australia
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52
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Sucre JMS, Vijayaraj P, Aros CJ, Wilkinson D, Paul M, Dunn B, Guttentag SH, Gomperts BN. Posttranslational modification of β-catenin is associated with pathogenic fibroblastic changes in bronchopulmonary dysplasia. Am J Physiol Lung Cell Mol Physiol 2016; 312:L186-L195. [PMID: 27941077 DOI: 10.1152/ajplung.00477.2016] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 12/02/2016] [Accepted: 12/02/2016] [Indexed: 11/22/2022] Open
Abstract
Bronchopulmonary dysplasia (BPD) is a common complication of premature birth. The histopathology of BPD is characterized by an arrest of alveolarization with fibroblast activation. The Wnt/β-catenin signaling pathway is important in early lung development. When Wnt signaling is active, phosphorylation of β-catenin by tyrosine kinases at activating sites, specifically at tyrosine 489 (Y489), correlates with nuclear localization of β-catenin. We examined fetal lung tissue, lung tissue from term newborns, and lung tissue from infants who died with BPD; we found nuclear β-catenin phosphorylation at Y489 in epithelial and mesenchymal cells in fetal tissue and BPD tissue, but not in the lungs of term infants. Using a 3D human organoid model, we found increased nuclear localization of β-catenin phosphorylated at Y489 (p-β-cateninY489) after exposure to alternating hypoxia and hyperoxia compared with organoids cultured in normoxia. Exogenous stimulation of the canonical Wnt pathway in organoids was sufficient to cause nuclear localization of p-β-cateninY489 in normoxia and mimicked the pattern of α-smooth muscle actin (α-SMA) expression seen with fibroblastic activation from oxidative stress. Treatment of organoids with a tyrosine kinase inhibitor prior to cyclic hypoxia-hyperoxia inhibited nuclear localization of p-β-cateninY489 and prevented α-SMA expression by fibroblasts. Posttranslational phosphorylation of β-catenin is a transient feature of normal lung development. Moreover, the persistence of p-β-cateninY489 is a durable marker of fibroblast activation in BPD and may play an important role in BPD disease pathobiology.
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Affiliation(s)
- Jennifer M S Sucre
- Mildred Stahlman Division of Neonatology, Department of Pediatrics, Vanderbilt University, Nashville, Tennessee;
| | - Preethi Vijayaraj
- UCLA Children's Discovery and Innovation Institute, Mattel Children's Hospital UCLA, Department of Pediatrics, David Geffen School of Medicine, UCLA, Los Angeles, California.,Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, California
| | - Cody J Aros
- UCLA Children's Discovery and Innovation Institute, Mattel Children's Hospital UCLA, Department of Pediatrics, David Geffen School of Medicine, UCLA, Los Angeles, California.,UCLA Department of Molecular Biology Interdepartmental Program, UCLA, Los Angeles, California
| | - Dan Wilkinson
- UCLA Department of Materials Science and Engineering, UCLA, Los Angeles, California
| | - Manash Paul
- UCLA Children's Discovery and Innovation Institute, Mattel Children's Hospital UCLA, Department of Pediatrics, David Geffen School of Medicine, UCLA, Los Angeles, California
| | - Bruce Dunn
- UCLA Department of Materials Science and Engineering, UCLA, Los Angeles, California
| | - Susan H Guttentag
- Mildred Stahlman Division of Neonatology, Department of Pediatrics, Vanderbilt University, Nashville, Tennessee
| | - Brigitte N Gomperts
- UCLA Children's Discovery and Innovation Institute, Mattel Children's Hospital UCLA, Department of Pediatrics, David Geffen School of Medicine, UCLA, Los Angeles, California.,Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, California.,Pulmonary Medicine, David Geffen School of Medicine, UCLA, Los Angeles, California; and.,Eli and Edythe Broad Stem Cell Research Center, UCLA, Los Angeles, California
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53
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Couroucli XI, Placencia JL, Cates LA, Suresh GK. Should we still use vitamin A to prevent bronchopulmonary dysplasia? J Perinatol 2016; 36:581-5. [PMID: 27228508 DOI: 10.1038/jp.2016.76] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 03/07/2016] [Accepted: 04/01/2016] [Indexed: 12/28/2022]
Abstract
Bronchopulmonary dysplasia (BPD) is associated with significant short- and long-term morbidity in preterm infants, and it can be prevented in some infants with vitamin A prophylaxis. Vitamin A, once widely used in neonatal intensive care, was scarce for the last few years, but has become available again at a much higher price, leading to dilemmas about its routine use. In this review we discuss experimental, clinical and socioeconomic evidence related to BPD, and provide a framework for clinicians and policy-makers to evaluate the value of vitamin A treatment and make decisions about its use for prevention of BPD.
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Affiliation(s)
- X I Couroucli
- Department of Pediatrics, Section of Neonatology, Texas Children's Hospital, Baylor College of Medicine, Houston, TX, USA
| | - J L Placencia
- Department of Pediatrics, Section of Neonatology, Texas Children's Hospital, Baylor College of Medicine, Houston, TX, USA
| | - L A Cates
- Department of Pediatrics, Section of Neonatology, Texas Children's Hospital, Baylor College of Medicine, Houston, TX, USA
| | - G K Suresh
- Department of Pediatrics, Section of Neonatology, Texas Children's Hospital, Baylor College of Medicine, Houston, TX, USA
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54
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Loscertales M, Nicolaou F, Jeanne M, Longoni M, Gould DB, Sun Y, Maalouf FI, Nagy N, Donahoe PK. Type IV collagen drives alveolar epithelial-endothelial association and the morphogenetic movements of septation. BMC Biol 2016; 14:59. [PMID: 27412481 PMCID: PMC4942891 DOI: 10.1186/s12915-016-0281-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 07/01/2016] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Type IV collagen is the main component of the basement membrane that gives strength to the blood-gas barrier (BGB). In mammals, the formation of a mature BGB occurs primarily after birth during alveologenesis and requires the formation of septa from the walls of the saccule. In contrast, in avians, the formation of the BGB occurs rapidly and prior to hatching. Mutation in basement membrane components results in an abnormal alveolar phenotype; however, the specific role of type IV collagen in regulating alveologenesis remains unknown. RESULTS We have performed a microarray expression analysis in late chick lung development and found that COL4A1 and COL4A2 were among the most significantly upregulated genes during the formation of the avian BGB. Using mouse models, we discovered that mutations in murine Col4a1 and Col4a2 genes affected the balance between lung epithelial progenitors and differentiated cells. Mutations in Col4a1 derived from the vascular component were sufficient to cause defects in vascular development and the BGB. We also show that Col4a1 and Col4a2 mutants displayed disrupted myofibroblast proliferation, differentiation and migration. Lastly, we revealed that addition of type IV collagen protein induced myofibroblast proliferation and migration in monolayer culture and increased the formation of mesenchymal-epithelial septal-like structures in co-culture. CONCLUSIONS Our study showed that type IV collagen and, therefore the basement membrane, play fundamental roles in coordinating alveolar morphogenesis. In addition to its role in the formation of epithelium and vasculature, type IV collagen appears to be key for alveolar myofibroblast development by inducing their proliferation, differentiation and migration throughout the developing septum.
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Affiliation(s)
- Maria Loscertales
- The Pediatric Surgical Research Laboratories, Massachusetts General Hospital, Boston, MA, 02114, USA.
- Department of Surgery, Harvard Medical School, Boston, MA, 02115, USA.
| | - Fotini Nicolaou
- The Pediatric Surgical Research Laboratories, Massachusetts General Hospital, Boston, MA, 02114, USA
| | - Marion Jeanne
- Departments of Ophthalmology and Anatomy, Institute for Human Genetics, University of California, San Francisco, School of Medicine, San Francisco, CA, 94143, USA
| | - Mauro Longoni
- The Pediatric Surgical Research Laboratories, Massachusetts General Hospital, Boston, MA, 02114, USA
- Department of Surgery, Harvard Medical School, Boston, MA, 02115, USA
| | - Douglas B Gould
- Departments of Ophthalmology and Anatomy, Institute for Human Genetics, University of California, San Francisco, School of Medicine, San Francisco, CA, 94143, USA
| | - Yunwei Sun
- The Pediatric Surgical Research Laboratories, Massachusetts General Hospital, Boston, MA, 02114, USA
| | - Faouzi I Maalouf
- The Pediatric Surgical Research Laboratories, Massachusetts General Hospital, Boston, MA, 02114, USA
| | - Nandor Nagy
- The Pediatric Surgical Research Laboratories, Massachusetts General Hospital, Boston, MA, 02114, USA
- Department of Surgery, Harvard Medical School, Boston, MA, 02115, USA
- Department of Human Anatomy, Histology and Embryology, Faculty of Medicine, Semmelweis University, Budapest, 1094, Hungary
| | - Patricia K Donahoe
- The Pediatric Surgical Research Laboratories, Massachusetts General Hospital, Boston, MA, 02114, USA
- Department of Surgery, Harvard Medical School, Boston, MA, 02115, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA
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55
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Boucherat O, Morissette MC, Provencher S, Bonnet S, Maltais F. Bridging Lung Development with Chronic Obstructive Pulmonary Disease. Relevance of Developmental Pathways in Chronic Obstructive Pulmonary Disease Pathogenesis. Am J Respir Crit Care Med 2016; 193:362-75. [PMID: 26681127 DOI: 10.1164/rccm.201508-1518pp] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Chronic obstructive pulmonary disease (COPD) is characterized by chronic airflow limitation. This generic term encompasses emphysema and chronic bronchitis, two common conditions, each having distinct but also overlapping features. Recent epidemiological and experimental studies have challenged the traditional view that COPD is exclusively an adult disease occurring after years of inhalational insults to the lungs, pinpointing abnormalities or disruption of the pathways that control lung development as an important susceptibility factor for adult COPD. In addition, there is growing evidence that emphysema is not solely a destructive process because it is also characterized by a failure in cell and molecular maintenance programs necessary for proper lung development. This leads to the concept that tissue regeneration required stimulation of signaling pathways that normally operate during development. We undertook a review of the literature to outline the contribution of developmental insults and genes in the occurrence and pathogenesis of COPD, respectively.
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Affiliation(s)
- Olivier Boucherat
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, Québec, Canada
| | - Mathieu C Morissette
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, Québec, Canada
| | - Steeve Provencher
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, Québec, Canada
| | - Sébastien Bonnet
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, Québec, Canada
| | - François Maltais
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, Québec, Canada
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56
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Boucherat O, Jeannotte L, Hadchouel A, Delacourt C, Benachi A. Pathomechanisms of Congenital Cystic Lung Diseases: Focus on Congenital Cystic Adenomatoid Malformation and Pleuropulmonary Blastoma. Paediatr Respir Rev 2016; 19:62-8. [PMID: 26907828 DOI: 10.1016/j.prrv.2015.11.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 11/01/2015] [Accepted: 11/08/2015] [Indexed: 02/05/2023]
Abstract
It is well established that a number of birth defects are associated with improper formation of the respiratory tract. Important progress has been made in the identification of components of the regulatory networks controlling lung morphogenesis. They comprise a variety of soluble factors, receptors, transcription factors, and miRNAs. However, the underlying molecular mechanisms remain unsolved and fundamental questions, such as those related to lung branching are still unanswered. Congenital cystic lung diseases consist of a heterogeneous group of rare lung diseases mainly detected prenatally and characterized by airway dilatation. Despite their apparent phenotypic heterogeneity, these malformations are proposed to be related to a common malformation sequence occurring during lung branching morphogenesis.
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Affiliation(s)
- Olivier Boucherat
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, QC, Canada, G1 V 4G5
| | - Lucie Jeannotte
- Centre de recherche sur le cancer de l'Université Laval, CRCHUQ, L'Hôtel-Dieu de Québec, QC, Canada; Département de Biologie Moléculaire, Biochimie Médicale et Pathologie, Université Laval, Québec, Canada
| | - Alice Hadchouel
- AP-HP, Hôpital Necker-Enfants Malades, Service de Pneumologie Pédiatrique, Centre de Référence pour les Maladies Respiratoires Rares de l'Enfant, Paris, France; INSERM, U955, IMRB, Equipe 04, Créteil, France; Université Paris-Descartes, Paris, France
| | - Christophe Delacourt
- AP-HP, Hôpital Necker-Enfants Malades, Service de Pneumologie Pédiatrique, Centre de Référence pour les Maladies Respiratoires Rares de l'Enfant, Paris, France; INSERM, U955, IMRB, Equipe 04, Créteil, France; Université Paris-Descartes, Paris, France
| | - Alexandra Benachi
- AP-HP, Hôpital Antoine-Béclère, Université Paris-Sud, Service de Gynécologie Obstétrique et Médecine de la Reproduction, 92141 Clamart, France; INSERM, UMR 986, Université Paris-Sud, Bicêtre, France
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57
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Sucre JMS, Wilkinson D, Vijayaraj P, Paul M, Dunn B, Alva-Ornelas JA, Gomperts BN. A three-dimensional human model of the fibroblast activation that accompanies bronchopulmonary dysplasia identifies Notch-mediated pathophysiology. Am J Physiol Lung Cell Mol Physiol 2016; 310:L889-98. [PMID: 26968771 DOI: 10.1152/ajplung.00446.2015] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 03/07/2016] [Indexed: 12/13/2022] Open
Abstract
Bronchopulmonary dysplasia (BPD) is a leading complication of premature birth and occurs primarily in infants delivered during the saccular stage of lung development. Histopathology shows decreased alveolarization and a pattern of fibroblast proliferation and differentiation to the myofibroblast phenotype. Little is known about the molecular pathways and cellular mechanisms that define BPD pathophysiology and progression. We have developed a novel three-dimensional human model of the fibroblast activation associated with BPD, and using this model we have identified the Notch pathway as a key driver of fibroblast activation and proliferation in response to changes in oxygen. Fetal lung fibroblasts were cultured on sodium alginate beads to generate lung organoids. After exposure to alternating hypoxia and hyperoxia, the organoids developed a phenotypic response characterized by increased α-smooth muscle actin (α-SMA) expression and other genes known to be upregulated in BPD and also demonstrated increased expression of downstream effectors of the Notch pathway. Inhibition of Notch with a γ-secretase inhibitor prevented the development of the pattern of cellular proliferation and α-SMA expression in our model. Analysis of human autopsy tissue from the lungs of infants who expired with BPD demonstrated evidence of Notch activation within fibrotic areas of the alveolar septae, suggesting that Notch may be a key driver of BPD pathophysiology.
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Affiliation(s)
- Jennifer M S Sucre
- UCLA Children's Discovery and Innovation Institute, Mattel Children's Hospital UCLA, Department of Pediatrics, David Geffen School of Medicine, UCLA, Los Angeles, California
| | - Dan Wilkinson
- UCLA Department of Materials Science and Engineering, UCLA, Los Angeles, California
| | - Preethi Vijayaraj
- UCLA Children's Discovery and Innovation Institute, Mattel Children's Hospital UCLA, Department of Pediatrics, David Geffen School of Medicine, UCLA, Los Angeles, California; Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, California; and
| | - Manash Paul
- UCLA Children's Discovery and Innovation Institute, Mattel Children's Hospital UCLA, Department of Pediatrics, David Geffen School of Medicine, UCLA, Los Angeles, California
| | - Bruce Dunn
- UCLA Department of Materials Science and Engineering, UCLA, Los Angeles, California
| | - Jackelyn A Alva-Ornelas
- UCLA Children's Discovery and Innovation Institute, Mattel Children's Hospital UCLA, Department of Pediatrics, David Geffen School of Medicine, UCLA, Los Angeles, California
| | - Brigitte N Gomperts
- UCLA Children's Discovery and Innovation Institute, Mattel Children's Hospital UCLA, Department of Pediatrics, David Geffen School of Medicine, UCLA, Los Angeles, California; Pulmonary Medicine, David Geffen School of Medicine, UCLA, Los Angeles, California; Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, California; and Eli and Edythe Broad Stem Cell Research Center, UCLA, Los Angeles, California
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58
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Leibel S, Post M. Endogenous and Exogenous Stem/Progenitor Cells in the Lung and Their Role in the Pathogenesis and Treatment of Pediatric Lung Disease. Front Pediatr 2016; 4:36. [PMID: 27148506 PMCID: PMC4830813 DOI: 10.3389/fped.2016.00036] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 03/31/2016] [Indexed: 12/30/2022] Open
Abstract
The lung is a complex organ with a vast surface area whose main function is to release cellular waste to be exhaled and to replenish the supply of oxygen to the tissues of the body. The conduction of air from the external environment is not without risks, and the lung contains many specialized epithelial cell subtypes that are protecting the lung from foreign material and injury. Specialized cell subtypes are produced during lung development in the fetus as well as postnatally and injury to them due to genetic disease, premature birth, or postnatal environmental injury may lead to devastating disease. Chronic diseases, such as bronchopulmonary dysplasia, cystic fibrosis, and pulmonary arterial hypertension, contribute significantly to morbidity and mortality worldwide, yet successful interventions are often limited. Stem/progenitor cells have emerged as a potentially new preventative or therapeutic option. They are generally defined by the ability to undergo self-renewal and give rise to more differentiated cells. They are important in the early development of embryonic structures and organ differentiation in utero. Postnatally, they function in continued growth, maintenance, and regeneration. Clinically, the immunomodulatory properties of some classes of stem/progenitor cells avoid the major obstacle of immunological rejection seen in organ transplantation and other cell therapies. This review highlights some known human progenitor/stem cells and the most recent advances in stem cell therapies both in vivo and in vitro to prevent and treat pediatric lung disease.
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Affiliation(s)
- Sandra Leibel
- Program of Physiology & Experimental Medicine, The Hospital for Sick Children, Toronto, ON, Canada; Department of Physiology, University of Toronto, Toronto, ON, Canada; Department of Pediatrics, University of California San Diego, San Diego, CA, USA
| | - Martin Post
- Program of Physiology & Experimental Medicine, The Hospital for Sick Children, Toronto, ON, Canada; Department of Physiology, University of Toronto, Toronto, ON, Canada
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59
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Olave N, Lal CV, Halloran B, Pandit K, Cuna AC, Faye-Petersen OM, Kelly DR, Nicola T, Benos PV, Kaminski N, Ambalavanan N. Regulation of alveolar septation by microRNA-489. Am J Physiol Lung Cell Mol Physiol 2015; 310:L476-87. [PMID: 26719145 DOI: 10.1152/ajplung.00145.2015] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 12/26/2015] [Indexed: 12/16/2022] Open
Abstract
MicroRNAs (miRs) are small conserved RNA that regulate gene expression. Bioinformatic analysis of miRNA profiles during mouse lung development indicated a role for multiple miRNA, including miRNA-489. miR-489 increased on completion of alveolar septation [postnatal day 42 (P42)], associated with decreases in its conserved target genes insulin-like growth factor-1 (Igf1) and tenascin C (Tnc). We hypothesized that dysregulation of miR-489 and its target genes Igf1 and Tnc contribute to hyperoxia-induced abnormal lung development. C57BL/6 mice were exposed to normoxia (21%) or hyperoxia (85% O2) from P4 to P14, in combination with intranasal locked nucleic acid against miR-489 to inhibit miR-489, cytomegalovirus promoter (pCMV)-miR-489 to overexpress miR-489, or empty vector. Hyperoxia reduced miR-489 and increased Igf1 and Tnc. Locked nucleic acid against miR-489 improved lung development during hyperoxia and did not alter it during normoxia, whereas miR-489 overexpression inhibited lung development during normoxia. The 3' untranslated region in vitro reporter studies confirmed Igf1 and Tnc as targets of miR-489. While miR-489 was of epithelial origin and present in exosomes, its targets Igf1 and Tnc were produced by fibroblasts. Infants with bronchopulmonary dysplasia (BPD) had reduced lung miR-489 and increased Igf1 and Tnc compared with normal preterm or term infants. These results suggest increased miR-489 is an inhibitor of alveolar septation. During hyperoxia or BPD, reduced miR-489 and increased Igf1 and Tnc may be inadequate attempts at compensation. Further inhibition of miR-489 may permit alveolar septation to proceed. The use of specific miRNA antagonists or agonists may be a therapeutic strategy for inhibited alveolarization, such as in BPD.
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Affiliation(s)
- Nelida Olave
- Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama
| | - Charitharth V Lal
- Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama
| | - Brian Halloran
- Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama
| | - Kusum Pandit
- Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Alain C Cuna
- Department of Pediatrics, University of Missouri-Kansas City School of Medicine, Kansas City, Missouri
| | - Ona M Faye-Petersen
- Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama
| | - David R Kelly
- Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Teodora Nicola
- Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama
| | - Panayiotis V Benos
- Department of Computational & Systems Biology, University of Pittsburgh, Pittsburgh, Pennsylvania; and
| | - Naftali Kaminski
- Division of Pulmonary, Critical Care and Sleep Medicine, Yale School of Medicine, New Haven, Connecticut
| | - Namasivayam Ambalavanan
- Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama; Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama;
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Mižíková I, Morty RE. The Extracellular Matrix in Bronchopulmonary Dysplasia: Target and Source. Front Med (Lausanne) 2015; 2:91. [PMID: 26779482 PMCID: PMC4688343 DOI: 10.3389/fmed.2015.00091] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 12/08/2015] [Indexed: 12/22/2022] Open
Abstract
Bronchopulmonary dysplasia (BPD) is a common complication of preterm birth that contributes significantly to morbidity and mortality in neonatal intensive care units. BPD results from life-saving interventions, such as mechanical ventilation and oxygen supplementation used to manage preterm infants with acute respiratory failure, which may be complicated by pulmonary infection. The pathogenic pathways driving BPD are not well-delineated but include disturbances to the coordinated action of gene expression, cell-cell communication, physical forces, and cell interactions with the extracellular matrix (ECM), which together guide normal lung development. Efforts to further delineate these pathways have been assisted by the use of animal models of BPD, which rely on infection, injurious mechanical ventilation, or oxygen supplementation, where histopathological features of BPD can be mimicked. Notable among these are perturbations to ECM structures, namely, the organization of the elastin and collagen networks in the developing lung. Dysregulated collagen deposition and disturbed elastin fiber organization are pathological hallmarks of clinical and experimental BPD. Strides have been made in understanding the disturbances to ECM production in the developing lung, but much still remains to be discovered about how ECM maturation and turnover are dysregulated in aberrantly developing lungs. This review aims to inform the reader about the state-of-the-art concerning the ECM in BPD, to highlight the gaps in our knowledge and current controversies, and to suggest directions for future work in this exciting and complex area of lung development (patho)biology.
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Affiliation(s)
- Ivana Mižíková
- Department of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany; Pulmonology, Department of Internal Medicine, University of Giessen and Marburg Lung Center, Giessen, Germany
| | - Rory E Morty
- Department of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany; Pulmonology, Department of Internal Medicine, University of Giessen and Marburg Lung Center, Giessen, Germany
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61
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Dénervaud V, Gremlich S, Trummer-Menzi E, Schittny JC, Roth-Kleiner M. Gene expression profile in newborn rat lungs after two days of recovery of mechanical ventilation. Pediatr Res 2015; 78:641-9. [PMID: 26353077 DOI: 10.1038/pr.2015.155] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 05/18/2015] [Indexed: 11/09/2022]
Abstract
BACKGROUND Preterm infants having immature lungs often require respiratory support, potentially leading to bronchopulmonary dysplasia (BPD). Conventional BPD rodent models based on mechanical ventilation (MV) present outcome measured at the end of the ventilation period. A reversible intubation and ventilation model in newborn rats recently allowed discovering that different sets of genes modified their expression related to time after MV. In a newborn rat model, the expression profile 48 h after MV was analyzed with gene arrays to detect potentially interesting candidates with an impact on BPD development. METHODS Rat pups were injected P4-5 with 2 mg/kg lipopolysaccharide (LPS). One day later, MV with 21 or 60% oxygen was applied during 6 h. Animals were sacrified 48 h after end of ventilation. Affymetrix gene arrays assessed the total gene expression profile in lung tissue. RESULTS In fully treated animals (LPS + MV + 60% O(2)) vs. controls, 271 genes changed expression significantly. All modified genes could be classified in six pathways: tissue remodeling/wound repair, immune system and inflammatory response, hematopoiesis, vasodilatation, and oxidative stress. Major alterations were found in the MMP and complement system. CONCLUSION MMPs and complement factors play a central role in several of the pathways identified and may represent interesting targets for BPD treatment/prevention.Bronchopulmonary dysplasia (BPD) is a chronic lung disease occurring in ~30% of preterm infants born less than 30 wk of gestation (1). Its main risk factors include lung immaturity due to preterm delivery, mechanical ventilation (MV), oxygen toxicity, chorioamnionitis, and sepsis. The main feature is an arrest of alveolar and capillary formation (2). Models trying to decipher genes involved in the pathophysiology of BPD are mainly based on MV and oxygen application to young mammals with immature lungs of different species (3). In newborn rodent models, analyses of lung structure and gene and protein expression are performed for practical reasons directly at the end of MV (4,5,6). However, later appearing changes of gene expression might also have an impact on lung development and the evolution towards BPD and cannot be discovered by such models. Recently, we developed a newborn rat model of MV using an atraumatic (orotracheal) intubation technique that allows the weaning of the newborn animal off anesthesia and MV, the extubation to spontaneous breathing, and therefore allows the evaluation of effects of MV after a ventilation-free period of recovery (7). Indeed, applying this concept of atraumatic intubation by direct laryngoscopy, we recently were able to show significant differences between gene expression changes appearing directly after MV compared to those measured after a ventilation-free interval of 48 h. Immediately after MV, inflammation-related genes showed a transitory modified expression, while another set of more structurally related genes changed their expression only after a delay of 2 d (7). Lung structure, analyzed by conventional 2D histology and also by 3D reconstruction using synchrotron x-ray tomographic microscopy revealed, 48 h after end of MV, a reduced complexity of lung architecture compared to the nonventilated rat lungs, similar to the typical findings in BPD. To extend these observations about late gene expression modifications, we performed with a similar model a full gene expression profile of lung tissue 48 h after the end of MV with either room air or 60% oxygen. Essentially, we measured changes in the expression of genes related to the MMPs and complement system which played a role in many of the six identified mostly affected pathways.
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Affiliation(s)
- Valérie Dénervaud
- Department of Pediatrics, Clinic of Neonatology, University Hospital of Lausanne, Lausanne, Switzerland
| | - Sandrine Gremlich
- Department of Pediatrics, Clinic of Neonatology, University Hospital of Lausanne, Lausanne, Switzerland
| | - Eliane Trummer-Menzi
- Department of Pediatrics, Clinic of Neonatology, University Hospital of Lausanne, Lausanne, Switzerland
| | | | - Matthias Roth-Kleiner
- Department of Pediatrics, Clinic of Neonatology, University Hospital of Lausanne, Lausanne, Switzerland
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Carrera P, Di Resta C, Volonteri C, Castiglioni E, Bonfiglio S, Lazarevic D, Cittaro D, Stupka E, Ferrari M, Somaschini M. Exome sequencing and pathway analysis for identification of genetic variability relevant for bronchopulmonary dysplasia (BPD) in preterm newborns: A pilot study. Clin Chim Acta 2015; 451:39-45. [PMID: 25578394 DOI: 10.1016/j.cca.2015.01.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Revised: 12/30/2014] [Accepted: 01/02/2015] [Indexed: 01/25/2023]
Affiliation(s)
- Paola Carrera
- Unit of Genomics for Diagnosis of Human Pathologies, Division of Genetics and Cell Biology, IRCCS Ospedale San Raffaele, Milano, Italy; Laboratory of Clinical Molecular Biology, IRCCS Ospedale San Raffaele, Milano, Italy.
| | - Chiara Di Resta
- Unit of Genomics for Diagnosis of Human Pathologies, Division of Genetics and Cell Biology, IRCCS Ospedale San Raffaele, Milano, Italy
| | | | - Emanuela Castiglioni
- Unit of Genomics for Diagnosis of Human Pathologies, Division of Genetics and Cell Biology, IRCCS Ospedale San Raffaele, Milano, Italy
| | - Silvia Bonfiglio
- Centre for Translational Genomics and Bioinformatics, IRCCS Ospedale San Raffaele, Milano, Italy
| | - Dejan Lazarevic
- Centre for Translational Genomics and Bioinformatics, IRCCS Ospedale San Raffaele, Milano, Italy
| | - Davide Cittaro
- Centre for Translational Genomics and Bioinformatics, IRCCS Ospedale San Raffaele, Milano, Italy
| | - Elia Stupka
- Centre for Translational Genomics and Bioinformatics, IRCCS Ospedale San Raffaele, Milano, Italy
| | - Maurizio Ferrari
- Unit of Genomics for Diagnosis of Human Pathologies, Division of Genetics and Cell Biology, IRCCS Ospedale San Raffaele, Milano, Italy; Laboratory of Clinical Molecular Biology, IRCCS Ospedale San Raffaele, Milano, Italy; Vita-Salute San Raffaele University, Milano, Italy
| | - Marco Somaschini
- Unit of Genomics for Diagnosis of Human Pathologies, Division of Genetics and Cell Biology, IRCCS Ospedale San Raffaele, Milano, Italy
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Yun EJ, Lorizio W, Seedorf G, Abman SH, Vu TH. VEGF and endothelium-derived retinoic acid regulate lung vascular and alveolar development. Am J Physiol Lung Cell Mol Physiol 2015; 310:L287-98. [PMID: 26566904 DOI: 10.1152/ajplung.00229.2015] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 11/04/2015] [Indexed: 12/24/2022] Open
Abstract
Prevention or treatment of lung diseases caused by the failure to form, or destruction of, existing alveoli, as observed in infants with bronchopulmonary dysplasia and adults with emphysema, requires understanding of the molecular mechanisms of alveolar development. In addition to its critical role in gas exchange, the pulmonary circulation also contributes to alveolar morphogenesis and maintenance by the production of paracrine factors, termed "angiocrines," that impact the development of surrounding tissue. To identify lung angiocrines that contribute to alveolar formation, we disrupted pulmonary vascular development by conditional inactivation of the Vegf-A gene during alveologenesis. This resulted in decreased pulmonary capillary and alveolar development and altered lung elastin and retinoic acid (RA) expression. We determined that RA is produced by pulmonary endothelial cells and regulates pulmonary angiogenesis and elastin synthesis by induction of VEGF-A and fibroblast growth factor (FGF)-18, respectively. Inhibition of RA synthesis in newborn mice decreased FGF-18 and elastin expression and impaired alveolarization. Treatment with RA and vitamin A partially reversed the impaired vascular and alveolar development induced by VEGF inhibition. Thus we identified RA as a lung angiocrine that regulates alveolarization through autocrine regulation of endothelial development and paracrine regulation of elastin synthesis via induction of FGF-18 in mesenchymal cells.
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Affiliation(s)
- Eun Jun Yun
- Department of Medicine, University of California, San Francisco, San Francisco, California; and
| | - Walter Lorizio
- Department of Medicine, University of California, San Francisco, San Francisco, California; and
| | - Gregory Seedorf
- Pediatric Heart Lung Center and Department of Pediatrics, University of Colorado Denver-Anschutz Medical Campus, Aurora, Colorado
| | - Steven H Abman
- Pediatric Heart Lung Center and Department of Pediatrics, University of Colorado Denver-Anschutz Medical Campus, Aurora, Colorado
| | - Thiennu H Vu
- Department of Medicine, University of California, San Francisco, San Francisco, California; and
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Niedermaier S, Hilgendorff A. Bronchopulmonary dysplasia - an overview about pathophysiologic concepts. Mol Cell Pediatr 2015; 2:2. [PMID: 26542292 PMCID: PMC4530566 DOI: 10.1186/s40348-015-0013-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 01/25/2015] [Indexed: 12/27/2022] Open
Abstract
Neonatal chronic lung disease in the preterm infant, i.e. bronchopulmonary dysplasia (BPD) is characterized by impaired pulmonary development with its effects persisting into adulthood. Triggered in the immature lung by infectious complications, oxygen toxicity and the impact of mechanical ventilation, a sustained inflammatory response, extensive remodeling of the extracellular matrix, increased apoptosis as well as altered growth factor signaling characterize the disease. The current review focuses on selected pathophysiologic processes and their interplay in disease development. Furthermore, the potential of both, acute and long-term changes to the pulmonary scaffold and the cellular interface in concert with dysregulated growth factor signaling to affect aging and repair processes in the adult lung is discussed.
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Affiliation(s)
- Sophie Niedermaier
- Comprehensive Pneumology Center (CPC), Helmholtz Zentrum München, Member of the German Center for Lung Research (DZL), Munich Max-Lebsche-Platz 31, 81377, Munich, Germany. .,Dr. von Hauner Children's Hospital, Ludwig-Maximilians University Munich, Munich, Germany.
| | - Anne Hilgendorff
- Comprehensive Pneumology Center (CPC), Helmholtz Zentrum München, Member of the German Center for Lung Research (DZL), Munich Max-Lebsche-Platz 31, 81377, Munich, Germany. .,Dr. von Hauner Children's Hospital, Ludwig-Maximilians University Munich, Munich, Germany.
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Zana-Taieb E, Pham H, Franco-Montoya ML, Jacques S, Letourneur F, Baud O, Jarreau PH, Vaiman D. Impaired alveolarization and intra-uterine growth restriction in rats: a postnatal genome-wide analysis. J Pathol 2015; 235:420-30. [DOI: 10.1002/path.4470] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 09/17/2014] [Accepted: 10/13/2014] [Indexed: 02/06/2023]
Affiliation(s)
- E Zana-Taieb
- Université Paris Descartes; Paris France
- Fondation PremUp, 53 avenue de l'Observatoire, 75014 Paris; France
- Institut National de la Santé et de la Recherche Médicale (INSERM) U1141; Paris France
- Assistance Publique - Hôpitaux de Paris, Service de Médecine et Réanimation Néonatales de Port-Royal, Groupe Hospitalier Cochin, Broca, Hôtel-Dieu, 53 Avenue de l'Observatoire, 75014 Paris; France
| | - H Pham
- Fondation PremUp, 53 avenue de l'Observatoire, 75014 Paris; France
- Institut National de la Santé et de la Recherche Médicale (INSERM) U1141; Paris France
| | - ML Franco-Montoya
- Institut National de la Santé et de la Recherche Médicale (INSERM) U955 IMRB Equipe 04, Faculté de Médecine de Créteil, 94010 Créteil; France
| | - S Jacques
- Genom'ic, INSERM U1016, CNRS UMR8104, Paris; France
| | - F Letourneur
- Genom'ic, INSERM U1016, CNRS UMR8104, Paris; France
| | - O Baud
- Fondation PremUp, 53 avenue de l'Observatoire, 75014 Paris; France
- Institut National de la Santé et de la Recherche Médicale (INSERM) U1141; Paris France
- Assistance Publique - Hôpitaux de Paris, Service de Réanimation et Pédiatrie Néonatales, Hôpital Robert Debré, Paris; France
- Université Paris Diderot; Paris France
| | - PH Jarreau
- Université Paris Descartes; Paris France
- Fondation PremUp, 53 avenue de l'Observatoire, 75014 Paris; France
- Institut National de la Santé et de la Recherche Médicale (INSERM) U1141; Paris France
- Assistance Publique - Hôpitaux de Paris, Service de Médecine et Réanimation Néonatales de Port-Royal, Groupe Hospitalier Cochin, Broca, Hôtel-Dieu, 53 Avenue de l'Observatoire, 75014 Paris; France
| | - D Vaiman
- Institut Cochin, INSERM U1016-CNRS, UMRS 104; Paris France
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Jones CV, Alikhan MA, O'Reilly M, Sozo F, Williams TM, Harding R, Jenkin G, Ricardo SD. The effect of CSF-1 administration on lung maturation in a mouse model of neonatal hyperoxia exposure. Respir Res 2014; 15:110. [PMID: 25192716 PMCID: PMC4172892 DOI: 10.1186/s12931-014-0110-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Accepted: 08/28/2014] [Indexed: 12/14/2022] Open
Abstract
Background Lung immaturity due to preterm birth is a significant complication affecting neonatal health. Despite the detrimental effects of supplemental oxygen on alveolar formation, it remains an important treatment for infants with respiratory distress. Macrophages are traditionally associated with the propagation of inflammatory insults, however increased appreciation of their diversity has revealed essential functions in development and regeneration. Methods Macrophage regulatory cytokine Colony-Stimulating Factor-1 (CSF-1) was investigated in a model of neonatal hyperoxia exposure, with the aim of promoting macrophages associated with alveologenesis to protect/rescue lung development and function. Neonatal mice were exposed to normoxia (21% oxygen) or hyperoxia (Hyp; 65% oxygen); and administered CSF-1 (0.5 μg/g, daily × 5) or vehicle (PBS) in two treatment regimes; 1) after hyperoxia from postnatal day (P)7-11, or 2) concurrently with five days of hyperoxia from P1-5. Lung structure, function and macrophages were assessed using alveolar morphometry, barometric whole-body plethysmography and flow cytometry. Results and discussion Seven days of hyperoxia resulted in an 18% decrease in body weight and perturbation of lung structure and function. In regime 1, growth restriction persisted in the Hyp + PBS and Hyp + CSF-1 groups, although perturbations in respiratory function were resolved by P35. CSF-1 increased CSF-1R+/F4/80+ macrophage number by 34% at P11 compared to Hyp + PBS, but was not associated with growth or lung structural rescue. In regime 2, five days of hyperoxia did not cause initial growth restriction in the Hyp + PBS and Hyp + CSF-1 groups, although body weight was decreased at P35 with CSF-1. CSF-1 was not associated with increased macrophages, or with functional perturbation in the adult. Overall, CSF-1 did not rescue the growth and lung defects associated with hyperoxia in this model; however, an increase in CSF-1R+ macrophages was not associated with an exacerbation of lung injury. The trophic functions of macrophages in lung development requires further elucidation in order to explore macrophage modulation as a strategy for promoting lung maturation.
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Watanabe-Takano H, Takano K, Sakamoto A, Matsumoto K, Tokuhisa T, Endo T, Hatano M. DA-Raf-dependent inhibition of the Ras-ERK signaling pathway in type 2 alveolar epithelial cells controls alveolar formation. Proc Natl Acad Sci U S A 2014; 111:E2291-300. [PMID: 24843139 PMCID: PMC4050578 DOI: 10.1073/pnas.1321574111] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Alveolar formation is coupled to the spatiotemporally regulated differentiation of alveolar myofibroblasts (AMYFs), which contribute to the morphological changes of interalveolar walls. Although the Ras-ERK signaling pathway is one of the key regulators for alveolar formation in developing lungs, the intrinsic molecular and cellular mechanisms underlying its role remain largely unknown. By analyzing the Ras-ERK signaling pathway during postnatal development of lungs, we have identified a critical role of DA-Raf1 (DA-Raf)-a dominant-negative antagonist for the Ras-ERK signaling pathway-in alveolar formation. DA-Raf-deficient mice displayed alveolar dysgenesis as a result of the blockade of AMYF differentiation. DA-Raf is predominantly expressed in type 2 alveolar epithelial cells (AEC2s) in developing lungs, and DA-Raf-dependent MEK1/2 inhibition in AEC2s suppresses expression of tissue inhibitor of matalloprotienase 4 (TIMP4), which prevents a subsequent proteolytic cascade matrix metalloproteinase (MMP)14-MMP2. Furthermore, MMP14-MMP2 proteolytic cascade regulates AMYF differentiation and alveolar formation. Therefore, DA-Raf-dependent inhibition of the Ras-ERK signaling pathway in AEC2s is required for alveolar formation via triggering MMP2 activation followed by AMYF differentiation. These findings reveal a pivotal role of the Ras-ERK signaling pathway in the dynamic regulation of alveolar development.
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Affiliation(s)
- Haruko Watanabe-Takano
- Departments of Biomedical Science andDepartment of Biology, Graduate School of Science andJapan Society for the Promotion of Science, Chiyoda-ku, Tokyo 102-0083, Japan; and
| | - Kazunori Takano
- Department of Biology, Graduate School of Science andGraduate School of Advanced Integration Science, Chiba University, Yayoicho, Inage-ku, Chiba 263-8522, Japan
| | - Akemi Sakamoto
- Developmental Genetics, Graduate School of Medicine, Chiba University, Inohana, Chuo-ku, Chiba 260-8670, Japan
| | - Kenji Matsumoto
- Department of Allergy and Immunology, National Research Institute for Child Health and Development, Setagaya-ku, Tokyo 157-8535, Japan
| | - Takeshi Tokuhisa
- Developmental Genetics, Graduate School of Medicine, Chiba University, Inohana, Chuo-ku, Chiba 260-8670, Japan
| | - Takeshi Endo
- Department of Biology, Graduate School of Science andGraduate School of Advanced Integration Science, Chiba University, Yayoicho, Inage-ku, Chiba 263-8522, Japan;
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Martin CR, Zaman MM, Gilkey C, Salguero MV, Hasturk H, Kantarci A, Van Dyke TE, Freedman SD. Resolvin D1 and lipoxin A4 improve alveolarization and normalize septal wall thickness in a neonatal murine model of hyperoxia-induced lung injury. PLoS One 2014; 9:e98773. [PMID: 24892762 PMCID: PMC4043836 DOI: 10.1371/journal.pone.0098773] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 05/07/2014] [Indexed: 12/13/2022] Open
Abstract
Background The critical fatty acids Docosahexaenoic Acid (DHA) and Arachidonic Acid (AA) decline in preterm infants within the first postnatal week and are associated with neonatal morbidities, including bronchopulmonary dysplasia (BPD). DHA and AA are precursors to downstream metabolites that terminate the inflammatory response. We hypothesized that treatment with Resolvin D1 and/or Lipoxin A4 would prevent lung injury in a murine model of BPD. Objective To determine the effect of Resolvin D1 and/or Lipoxin A4 on hyperoxia-induced lung injury. Methods C57/BL6 pups were randomized at birth to Room Air, Hyperoxia (>90% oxygen), Hyperoxia + Resolvin D1, Hyperoxia + Lipoxin A4, or Hyperoxia + Resolvin D1/Lipoxin A4. Resolvin D1 and/or Lipoxin A4 (2 ng/g) were given IP on days 0, 3, 6, and 9. On day 10, mice were sacrificed and lungs collected for morphometric analyses including Mean Linear Intercept (MLI), Radial Alveolar Count (RAC), and Septal Thickness (ST); RT-PCR analyses of biomarkers of lung development and inflammation; and ELISA for TGFβ1 and TGFβ2. Result The increased ST observed with hyperoxia exposure was normalized by both Resolvin D1 and Lipoxin A4; while, hyperoxia-induced alveolar simplification was attenuated by Lipoxin A4. Relative to hyperoxia, Resolvin D1 reduced the gene expression of CXCL2 (2.9 fold), TIMP1 (6.7 fold), and PPARγ (4.8 fold). Treatment with Lipoxin A4 also led to a reduction of CXCL2 (2.4 fold) while selectively increasing TGFβ2 (2.1 fold) and Smad3 (1.58 fold). Conclusion The histologic and biochemical changes seen in hyperoxia-induced lung injury in this murine model can be reversed by the addition of DHA and AA fatty acid downstream metabolites that terminate the inflammatory pathways and modulate growth factors. These fatty acids or their metabolites may be novel therapies to prevent or treat lung injury in preterm infants.
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Affiliation(s)
- Camilia R. Martin
- Department of Neonatology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States of America
- Division of Translational Research, Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States of America
- * E-mail:
| | - Munir M. Zaman
- Division of Gastroenterology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States of America
| | - Calvin Gilkey
- Division of Gastroenterology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States of America
| | - Maria V. Salguero
- Division of Gastroenterology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States of America
| | - Hatice Hasturk
- Department of Applied Oral Sciences, Center for Periodontology, Forsyth Institute, Cambridge, Massachusetts, United States of America
| | - Alpdogan Kantarci
- Department of Applied Oral Sciences, Center for Periodontology, Forsyth Institute, Cambridge, Massachusetts, United States of America
| | - Thomas E. Van Dyke
- Department of Applied Oral Sciences, Center for Periodontology, Forsyth Institute, Cambridge, Massachusetts, United States of America
| | - Steven D. Freedman
- Division of Translational Research, Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States of America
- Division of Gastroenterology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States of America
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Abstract
PURPOSE OF REVIEW Advances in medical therapy have increased survival of extremely premature infants and changed the pathology of bronchopulmonary dysplasia (BPD) from one of acute lung injury to a disease of disrupted lung development. With this evolution, new questions emerge regarding the molecular mechanisms that control postnatal lung development, the effect of early disruptions of postnatal lung development on long-term lung function, and the existence of endogenous mechanisms that permit lung regeneration after injury. RECENT FINDINGS Recent data demonstrate that a significant component of alveolarization, the final stage of lung development, occurs postnatally. Further, clinical and experimental studies demonstrate that premature birth disrupts alveolarization, decreasing the gas exchange surface area of the lung and causing BPD. BPD is associated with significant short-term morbidity, and new longitudinal, clinical data demonstrate that survivors of BPD have long-standing deficits in lung function and may be at risk for the development of additional lung disease as adults. Unfortunately, current care is mainly supportive with few effective therapies that prevent or treat established BPD. These studies underscore the need to further elucidate the mechanisms that direct postnatal lung growth and develop innovative strategies to stimulate lung regeneration. SUMMARY Despite significant improvements in the care and survival of extremely premature infants, BPD remains a major clinical problem. Although efforts should remain focused on the prevention of preterm labor and BPD, novel research aimed at promoting postnatal alveolarization offers a unique opportunity to develop effective strategies to treat established BPD.
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Pieretti AC, Ahmed AM, Roberts JD, Kelleher CM. A novel in vitro model to study alveologenesis. Am J Respir Cell Mol Biol 2014; 50:459-69. [PMID: 24066869 DOI: 10.1165/rcmb.2013-0056oc] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Many pediatric pulmonary diseases are associated with significant morbidity and mortality due to impairment of alveolar development. The lack of an appropriate in vitro model system limits the identification of therapies aimed at improving alveolarization. Herein, we characterize an ex vivo lung culture model that facilitates investigation of signaling pathways that influence alveolar septation. Postnatal Day 4 (P4) mouse pup lungs were inflated with 0.4% agarose, sliced, and cultured within a collagen matrix in medium that was optimized to support cell proliferation and promote septation. Lung slices were grown with and without 1D11, an active transforming growth factor-β-neutralizing antibody. After 4 days, the lung sections (designated P4 + 4) and noncultured lung sections were examined using quantitative morphometry to assess alveolar septation and immunohistochemistry to evaluate cell proliferation and differentiation. We observed that the P4 + 4 lung sections exhibited ex vivo alveolarization, as evidenced by an increase in septal density, thinning of septal walls, and a decrease in mean linear intercept comparable to P8, age-matched, uncultured lungs. Moreover, immunostaining showed ongoing cell proliferation and differentiation in cultured lungs that were similar to P8 controls. Cultured lungs exposed to 1D11 had a distinct phenotype of decreased septal density when compared with untreated P4 + 4 lungs, indicating the utility of investigating signaling in these lung slices. These results indicate that this novel lung culture system is optimized to permit the investigation of pathways involved in septation, and potentially the identification of therapeutic targets that enhance alveolarization.
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Affiliation(s)
- Alberto C Pieretti
- 1 Department of Pediatric Surgery, MassGeneral Hospital for Children, Boston, Massachusetts
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Hilgendorff A, Reiss I, Ehrhardt H, Eickelberg O, Alvira CM. Chronic lung disease in the preterm infant. Lessons learned from animal models. Am J Respir Cell Mol Biol 2014; 50:233-45. [PMID: 24024524 DOI: 10.1165/rcmb.2013-0014tr] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Neonatal chronic lung disease, also known as bronchopulmonary dysplasia (BPD), is the most common complication of premature birth, affecting up to 30% of very low birth weight infants. Improved medical care has allowed for the survival of the most premature infants and has significantly changed the pathology of BPD from a disease marked by severe lung injury to the "new" form characterized by alveolar hypoplasia and impaired vascular development. However, increased patient survival has led to a paucity of pathologic specimens available from infants with BPD. This, combined with the lack of a system to model alveolarization in vitro, has resulted in a great need for animal models that mimic key features of the disease. To this end, a number of animal models have been created by exposing the immature lung to injuries induced by hyperoxia, mechanical stretch, and inflammation and most recently by the genetic modification of mice. These animal studies have 1) allowed insight into the mechanisms that determine alveolar growth, 2) delineated factors central to the pathogenesis of neonatal chronic lung disease, and 3) informed the development of new therapies. In this review, we summarize the key findings and limitations of the most common animal models of BPD and discuss how knowledge obtained from these studies has informed clinical care. Future studies should aim to provide a more complete understanding of the pathways that preserve and repair alveolar growth during injury, which might be translated into novel strategies to treat lung diseases in infants and adults.
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Affiliation(s)
- Anne Hilgendorff
- 1 Department of Perinatology Grosshadern, Ludwig-Maximilian-University, Munich, Germany
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Hadchouel A, Franco-Montoya ML, Delacourt C. Altered lung development in bronchopulmonary dysplasia. ACTA ACUST UNITED AC 2014; 100:158-67. [PMID: 24638954 DOI: 10.1002/bdra.23237] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2013] [Revised: 02/09/2014] [Accepted: 02/11/2014] [Indexed: 11/11/2022]
Abstract
Bronchopulmonary dysplasia (BPD) is the main respiratory sequela of extreme prematurity. Its pathophysiology is complex, involving interactions between host and environment, likely to be significantly influenced by genetic factors. Thus, the clinical presentation and histological lesions have evolved over time, along with the reduction in neonatal injuries, and the care of more immature children. Impaired alveolar growth, however, is a lesion consistently observed in BPD, such that it is a key feature in BPD, and is even the dominant characteristic of the so-called "new" forms of BPD. This review describes the key molecular pathways that are believed to be involved in the genesis of BPD. Much of our understanding is based on animal models, but this is increasingly being enriched by genetic approaches, and long-term respiratory functional studies.
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Affiliation(s)
- Alice Hadchouel
- INSERM, U955, IMRB, Equipe 04, Créteil, France; AP-HP, Hôpital Necker-Enfants Malades, service de Pneumologie Pédiatrique, Centre de Référence pour les Maladies Respiratoires Rares de l'Enfant, Paris, France; Université Paris-Descartes, Paris, France
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Witsch TJ, Niess G, Sakkas E, Likhoshvay T, Becker S, Herold S, Mayer K, Vadász I, Roberts JD, Seeger W, Morty RE. Transglutaminase 2: a new player in bronchopulmonary dysplasia? Eur Respir J 2014; 44:109-21. [PMID: 24603819 DOI: 10.1183/09031936.00075713] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Aberrant remodelling of the extracellular matrix in the developing lung may underlie arrested alveolarisation associated with bronchopulmonary dysplasia (BPD). Transglutaminases are regulators of extracellular matrix remodelling. Therefore, the expression and activity of transglutaminases were assessed in lungs from human neonates with BPD and in a rodent model of BPD. Transglutaminase expression and localisation were assessed by RT-PCR, immunoblotting, activity assay and immunohistochemical analyses of human and mouse lung tissues. Transglutaminase regulation by transforming growth factor (TGF)-β was investigated in lung cells by luciferase-based reporter assay and RT-PCR. TGF-β signalling was neutralised in vivo in an animal model of BPD, to determine whether TGF-β mediated the hyperoxia-induced changes in transglutaminase expression. Transglutaminase 2 expression was upregulated in the lungs of preterm infants with BPD and in the lungs of hyperoxia-exposed mouse pups, where lung development was arrested. Transglutaminase 2 localised to the developing alveolar septa. TGF-β was identified as a regulator of transglutaminase 2 expression in human and mouse lung epithelial cells. In vivo neutralisation of TGF-β signalling partially restored normal lung structure and normalised lung transglutaminase 2 mRNA expression. Our data point to a role for perturbed transglutaminase 2 activity in the arrested alveolarisation associated with BPD.
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Affiliation(s)
- Thilo J Witsch
- Dept of Internal Medicine, University of Giessen and Marburg Lung Center, Giessen
| | - Gero Niess
- Dept of Internal Medicine, University of Giessen and Marburg Lung Center, Giessen Dept of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Elpidoforos Sakkas
- Dept of Internal Medicine, University of Giessen and Marburg Lung Center, Giessen Dept of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Tatyana Likhoshvay
- Dept of Internal Medicine, University of Giessen and Marburg Lung Center, Giessen Dept of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Simone Becker
- Dept of Internal Medicine, University of Giessen and Marburg Lung Center, Giessen Dept of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Susanne Herold
- Dept of Internal Medicine, University of Giessen and Marburg Lung Center, Giessen
| | - Konstantin Mayer
- Dept of Internal Medicine, University of Giessen and Marburg Lung Center, Giessen
| | - István Vadász
- Dept of Internal Medicine, University of Giessen and Marburg Lung Center, Giessen
| | - Jesse D Roberts
- Cardiovascular Research Center, Massachusetts General Hospital, Charlestown, MA, USA
| | - Werner Seeger
- Dept of Internal Medicine, University of Giessen and Marburg Lung Center, Giessen Dept of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Rory E Morty
- Dept of Internal Medicine, University of Giessen and Marburg Lung Center, Giessen Dept of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
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74
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Steer JH, Mann TS, Lo SZY, Inglis JJ, Yap HS, Henry PJ, Joyce DA. Early induction of uncoupling protein-2 in pulmonary macrophages in hyperoxia-associated lung injury. Inhal Toxicol 2014; 25:544-52. [PMID: 23905971 DOI: 10.3109/08958378.2013.810679] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
CONTEXT High concentrations of inspired oxygen contribute to the pathogenesis of neonatal bronchopulmonary dysplasia and adult acute respiratory distress syndrome. Animal models of hyperoxia-associated lung injury (HALI) are characterized by enhanced generation of reactive oxygen species (ROS) and an adaptive antioxidant response. ROS contribute to pathogenesis, partly through enhancing pro-inflammatory activity in macrophages. Uncoupling protein-2 (UCP2) is an inner mitochondrial membrane protein whose expression lowers mitochondrial superoxide (O₂ⁱ⁻) production. UCP2, therefore, has potential to contribute to antioxidant response. It is inducible in macrophages. OBJECTIVES AND METHODS We hypothesized that induction of UCP2 occurred in response to pulmonary hyperoxia in vivo and that expression localized to pulmonary macrophages. We then investigated mechanisms of UCP2 regulation in hyperoxia-exposed macrophages in vitro and correlated changing UCP2 expression with mitochondrial membrane potential (Δψm) and O₂ⁱ⁻ production. RESULTS UCP2 is induced in lungs of mice within 1 h of hyperoxia exposure. Induction occurs in pulmonary alveolar macrophages in vivo, and can be replicated in vitro in isolated macrophages. UCP2 mRNA does not change. UCP2 increases quickly after the first hyperoxia-induced burst of mitochondrial O₂ⁱ⁻ generation. Suppression of Δψm and mitochondrial O₂ⁱ⁻ production follow and persist while UCP2 is elevated. DISCUSSION AND CONCLUSIONS Induction of UCP2 is an early response to hyperoxia in pulmonary macrophages. The mechanism is post-transcriptional. UCP2 induction follows a transient rise in mitochondrial ROS generation. The subsequent falls in Δψm and mitochondrial O₂ⁱ⁻ support the notion that regulable UCP2 expression in macrophages acts to contain mitochondrial ROS generation. That, in turn, may limit inappropriate pro-inflammatory activation in HALI.
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Affiliation(s)
- James H Steer
- School of Medicine & Pharmacology, University of Western Australia, Crawley, Western Australia, Australia
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75
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Koskinen A, Lukkarinen H, Laine J, Ahotupa M, Kääpä P, Soukka H. Delay in rat lung alveolarization after the combined exposure of maternal hyperglycemia and postnatal hyperoxia. Pediatr Pulmonol 2014; 49:179-88. [PMID: 23836626 DOI: 10.1002/ppul.22837] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Accepted: 05/18/2013] [Indexed: 01/05/2023]
Abstract
BACKGROUND Maternal diabetes interferes with fetal lung development and postnatal treatments may further disturb pulmonary growth. Therefore, we investigated the effect of postnatal oxygen exposure on alveolar development in neonatal rat lungs pre-exposed to intrauterine hyperglycemia. METHODS Diabetes was induced in Sprague-Dawley rats with streptozotocin injection before pregnancy. Hyperglycemia-exposed and control litters were randomized to breath room air or 85% oxygen for 7 days after birth. Lungs were analyzed on postnatal d7 for weight, morphology, apoptosis, proliferation, and biomarkers of oxidative stress. RESULTS Maternal hyperglycemia accelerated lung development as demonstrated by thinner alveolar walls and slightly increased secondary septation when compared to room air bred rats. Hyperoxia alone caused thin-walled and enlarged alveoli with few secondary septa. Interestingly, the dual exposure inhibited the thinning of alveolar walls and the disappearance of mesenchymal cells from the alveolar walls together with the delay in the formation of alveoli and secondary crests. While the lungs' oxidative stress was similar in all groups, pulmonary apoptosis and proliferation were altered. CONCLUSION Our results thus indicate that the hyperglycemic priming of the fetal lung modifies the deleterious effect of hyperoxia on alveolarization in neonatal rats.
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Affiliation(s)
- Anna Koskinen
- Research Centre of Applied and Preventive Cardiovascular Medicine (CAPC), University Hospital of Turku, Turku, Finland; Department of Paediatrics, University Hospital of Turku, Turku, Finland
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76
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Pais RS, Moreno-Barriuso N, Hernández-Porras I, López IP, De Las Rivas J, Pichel JG. Transcriptome analysis in prenatal IGF1-deficient mice identifies molecular pathways and target genes involved in distal lung differentiation. PLoS One 2013; 8:e83028. [PMID: 24391734 PMCID: PMC3877002 DOI: 10.1371/journal.pone.0083028] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Accepted: 10/30/2013] [Indexed: 01/31/2023] Open
Abstract
Background Insulin-like Growth Factor 1 (IGF1) is a multifunctional regulator of somatic growth and development throughout evolution. IGF1 signaling through IGF type 1 receptor (IGF1R) controls cell proliferation, survival and differentiation in multiple cell types. IGF1 deficiency in mice disrupts lung morphogenesis, causing altered prenatal pulmonary alveologenesis. Nevertheless, little is known about the cellular and molecular basis of IGF1 activity during lung development. Methods/Principal Findings Prenatal Igf1−/− mutant mice with a C57Bl/6J genetic background displayed severe disproportional lung hypoplasia, leading to lethal neonatal respiratory distress. Immuno-histological analysis of their lungs showed a thickened mesenchyme, alterations in extracellular matrix deposition, thinner smooth muscles and dilated blood vessels, which indicated immature and delayed distal pulmonary organogenesis. Transcriptomic analysis of Igf1−/− E18.5 lungs using RNA microarrays identified deregulated genes related to vascularization, morphogenesis and cellular growth, and to MAP-kinase, Wnt and cell-adhesion pathways. Up-regulation of immunity-related genes was verified by an increase in inflammatory markers. Increased expression of Nfib and reduced expression of Klf2, Egr1 and Ctgf regulatory proteins as well as activation of ERK2 MAP-kinase were corroborated by Western blot. Among IGF-system genes only IGFBP2 revealed a reduction in mRNA expression in mutant lungs. Immuno-staining patterns for IGF1R and IGF2, similar in both genotypes, correlated to alterations found in specific cell compartments of Igf1−/− lungs. IGF1 addition to Igf1−/− embryonic lungs cultured ex vivo increased airway septa remodeling and distal epithelium maturation, processes accompanied by up-regulation of Nfib and Klf2 transcription factors and Cyr61 matricellular protein. Conclusions/Significance We demonstrated the functional tissue specific implication of IGF1 on fetal lung development in mice. Results revealed novel target genes and gene networks mediators of IGF1 action on pulmonary cellular proliferation, differentiation, adhesion and immunity, and on vascular and distal epithelium maturation during prenatal lung development.
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Affiliation(s)
- Rosete Sofía Pais
- Centro de Investigación Biomédica de la Rioja, Fundación Rioja Salud, Logroño, Spain
| | - Nuria Moreno-Barriuso
- Instituto de Biología Molecular y Celular del Cáncer - Centro de Investigación del Cáncer, Consejo Superior de Investigaciones Científicas – University of Salamanca, Salamanca, Spain
| | - Isabel Hernández-Porras
- Instituto de Biología Molecular y Celular del Cáncer - Centro de Investigación del Cáncer, Consejo Superior de Investigaciones Científicas – University of Salamanca, Salamanca, Spain
| | - Icíar Paula López
- Centro de Investigación Biomédica de la Rioja, Fundación Rioja Salud, Logroño, Spain
| | - Javier De Las Rivas
- Instituto de Biología Molecular y Celular del Cáncer - Centro de Investigación del Cáncer, Consejo Superior de Investigaciones Científicas – University of Salamanca, Salamanca, Spain
| | - José García Pichel
- Centro de Investigación Biomédica de la Rioja, Fundación Rioja Salud, Logroño, Spain
- * E-mail:
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77
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Gabehart K, Correll KA, Yang J, Collins ML, Loader JE, Leach S, White CW, Dakhama A. Transcriptome profiling of the newborn mouse lung response to acute ozone exposure. Toxicol Sci 2013; 138:175-90. [PMID: 24336422 DOI: 10.1093/toxsci/kft276] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Ozone pollution is associated with adverse effects on respiratory health in adults and children but its effects on the neonatal lung remain unknown. This study was carried out to define the effect of acute ozone exposure on the neonatal lung and to profile the transcriptome response. Newborn mice were exposed to ozone or filtered air for 3h. Total RNA was isolated from lung tissues at 6 and 24h after exposure and was subjected to microarray gene expression analysis. Compared to filtered air-exposed littermates, ozone-exposed newborn mice developed a small but significant neutrophilic airway response associated with increased CXCL1 and CXCL5 expression in the lung. Transcriptome analysis indicated that 455 genes were down-regulated and 166 genes were up-regulated by at least 1.5-fold at 6h post-ozone exposure (t-test, p < .05). At 24h, 543 genes were down-regulated and 323 genes were up-regulated in the lungs of ozone-exposed, compared to filtered air-exposed, newborn mice (t-test, p < .05). After controlling for false discovery rate, 50 genes were identified as significantly down-regulated and only a few (RORC, GRP, VREB3, and CYP2B6) were up-regulated at 24h post-ozone exposure (q < .05). Gene ontology enrichment analysis revealed that cell cycle-associated functions including cell division/proliferation were the most impacted pathways, which were negatively regulated by ozone exposure, an adverse effect that was associated with reduced bromo-deoxyuridine incorporation. These results demonstrate that acute ozone exposure alters cell proliferation in the developing neonatal lung through a global suppression of cell cycle function.
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78
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Witsch TJ, Turowski P, Sakkas E, Niess G, Becker S, Herold S, Mayer K, Vadász I, Roberts JD, Seeger W, Morty RE. Deregulation of the lysyl hydroxylase matrix cross-linking system in experimental and clinical bronchopulmonary dysplasia. Am J Physiol Lung Cell Mol Physiol 2013; 306:L246-59. [PMID: 24285264 DOI: 10.1152/ajplung.00109.2013] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Bronchopulmonary dysplasia (BPD) is a common and serious complication of premature birth, characterized by a pronounced arrest of alveolar development. The underlying pathophysiological mechanisms are poorly understood although perturbations to the maturation and remodeling of the extracellular matrix (ECM) are emerging as candidate disease pathomechanisms. In this study, the expression and regulation of three members of the lysyl hydroxylase family of ECM remodeling enzymes (Plod1, Plod2, and Plod3) in clinical BPD, as well as in an experimental animal model of BPD, were addressed. All three enzymes were localized to the septal walls in developing mouse lungs, with Plod1 also expressed in the vessel walls of the developing lung and Plod3 expressed uniquely at the base of developing septa. The expression of plod1, plod2, and plod3 was upregulated in the lungs of mouse pups exposed to 85% O2, an experimental animal model of BPD. Transforming growth factor (TGF)-β increased plod2 mRNA levels and activated the plod2 promoter in vitro in lung epithelial cells and in lung fibroblasts. Using in vivo neutralization of TGF-β signaling in the experimental animal model of BPD, TGF-β was identified as the regulator of aberrant plod2 expression. PLOD2 mRNA expression was also elevated in human neonates who died with BPD or at risk for BPD, compared with neonates matched for gestational age at birth or chronological age at death. These data point to potential roles for lysyl hydroxylases in normal lung development, as well as in perturbed late lung development associated with BPD.
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Affiliation(s)
- Thilo J Witsch
- Dept. of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Parkstrasse 1, D-61231 Bad Nauheim, Germany.
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79
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Zana-Taieb E, Butruille L, Franco-Montoya ML, Lopez E, Vernier F, Grandvuillemin I, Evain-Brion D, Deruelle P, Baud O, Delacourt C, Jarreau PH. Effect of two models of intrauterine growth restriction on alveolarization in rat lungs: morphometric and gene expression analysis. PLoS One 2013; 8:e78326. [PMID: 24278109 PMCID: PMC3836790 DOI: 10.1371/journal.pone.0078326] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Accepted: 09/11/2013] [Indexed: 01/21/2023] Open
Abstract
Intrauterine growth restriction (IUGR) in preterm infants increases the risk of bronchopulmonary dysplasia, characterized by arrested alveolarization. We evaluated the impact of two different rat models (nitric oxide synthase inhibition or protein deprivation) of IUGR on alveolarization, before, during, and at the end of this postnatal process. We studied IUGR rat pups of dams fed either a low protein (LPD) or a normal diet throughout gestation and pups of dams treated by continuous infusion of Nω-nitro-L-arginine methyl ester (L-NAME) or its diluent on the last four days of gestation. Morphometric parameters, alveolar surface (Svap), mean linear intercept (MLI) and radial alveolar count (RAC) and transcriptomic analysis were determined with special focus on genes involved in alveolarization. IUGR pups regained normal weight at day 21 in the two treated groups. In the LPD group, Svap, MLI and RAC were not different from those of controls at day 4, but were significantly decreased at day 21, indicating alveolarization arrest. In the L-NAME group, Svap and RAC were significantly decreased and MLI was increased at day 4 with complete correction at day 21. In the L-NAME model, several factors involved in alveolarization, VEGF, VEGF-R1 and –R2, MMP14, MMP16, FGFR3 and 4, FGF18 and 7, were significantly decreased at day 4 and/or day 10, while the various factors studied were not modified in the LPD group. These results demonstrate that only maternal protein deprivation leads to sustained impairment of alveolarization in rat pups, whereas L-NAME impairs lung development before alveolarization. Known growth factors involved in lung development do not seem to be involved in LPD-induced alveolarization disorders, raising the question of a possible programming of altered alveolarization.
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Affiliation(s)
- Elodie Zana-Taieb
- Institut National de la Santé Et de la Recherche Médicale (INSERM) U767, Paris, France
- PremUp, Paris, France
- Service de Médecine et Réanimation néonatales de Port-Royal, Groupe hospitalier Cochin, Broca, Hôtel-Dieu, Assistance Publique – Hôpitaux de Paris, Paris, France
- Université Paris Descartes, Paris, France
- * E-mail:
| | - Laura Butruille
- Unité environnement périnatal et croissance, EA4489, Faculté de Médecine, Pôle recherche, IFR 114,Université Lille Nord de France, Lille, France
| | | | - Emmanuel Lopez
- Institut National de la Santé Et de la Recherche Médicale (INSERM) U767, Paris, France
- PremUp, Paris, France
- Service de Médecine et Réanimation néonatales de Port-Royal, Groupe hospitalier Cochin, Broca, Hôtel-Dieu, Assistance Publique – Hôpitaux de Paris, Paris, France
| | - Flore Vernier
- Institut National de la Santé Et de la Recherche Médicale (INSERM) U767, Paris, France
- PremUp, Paris, France
| | - Isabelle Grandvuillemin
- Institut National de la Santé Et de la Recherche Médicale (INSERM) UMR 1076, Faculté de Pharmacie, Université de la Méditerranée. Marseille, France
| | - Danièle Evain-Brion
- Institut National de la Santé Et de la Recherche Médicale (INSERM) U767, Paris, France
- PremUp, Paris, France
- Université Paris Descartes, Paris, France
| | - Philippe Deruelle
- Unité environnement périnatal et croissance, EA4489, Faculté de Médecine, Pôle recherche, IFR 114,Université Lille Nord de France, Lille, France
| | - Olivier Baud
- PremUp, Paris, France
- Institut National de la Santé Et de la Recherche Médicale (INSERM) U676, Paris, France
- Service de Réanimation et Pédiatrie néonatales, Hôpital Robert Debré, Assistance Publique – Hôpitaux de Paris, Paris, France
- Université Paris Diderot, Paris, France
| | - Christophe Delacourt
- PremUp, Paris, France
- Institut National de la Santé Et de la Recherche Médicale (INSERM) U955 IMRB Equipe 04, Créteil, France
- Service de Pneumologie Pédiatrique, Hôpital Necker-Enfants Malades, Assistance Publique – Hôpitaux de Paris, Paris, France
- Université Paris Descartes, Paris, France
| | - Pierre-Henri Jarreau
- Institut National de la Santé Et de la Recherche Médicale (INSERM) U767, Paris, France
- PremUp, Paris, France
- Service de Médecine et Réanimation néonatales de Port-Royal, Groupe hospitalier Cochin, Broca, Hôtel-Dieu, Assistance Publique – Hôpitaux de Paris, Paris, France
- Université Paris Descartes, Paris, France
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80
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Gene expression profiling in preterm infants: new aspects of bronchopulmonary dysplasia development. PLoS One 2013; 8:e78585. [PMID: 24194948 PMCID: PMC3806835 DOI: 10.1371/journal.pone.0078585] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Accepted: 09/23/2013] [Indexed: 11/22/2022] Open
Abstract
Rationale Bronchopulmonary dysplasia is one of the most serious complications observed in premature infants. Thanks to microarray technique, expression of nearly all human genes can be reliably evaluated. Objective To compare whole genome expression in the first month of life in groups of infants with and without bronchopulmonary dysplasia. Methods 111 newborns were included in the study. The mean birth weight was 1029g (SD:290), and the mean gestational age was 27.8 weeks (SD:2.5). Blood samples were drawn from the study participants on the 5th, 14th and 28th day of life. The mRNA samples were evaluated for gene expression with the use of GeneChip® Human Gene 1.0 ST microarrays. The infants were divided into two groups: bronchopulmonary dysplasia (n=68) and control (n=43). Results Overall 2086 genes were differentially expressed on the day 5, only 324 on the day 14 and 3498 on the day 28. Based on pathway enrichment analysis we found that the cell cycle pathway was up-regulated in the bronchopulmonary dysplasia group. The activation of this pathway does not seem to be related with the maturity of the infant. Four pathways related to inflammatory response were continuously on the 5th, 14th and 28th day of life down-regulated in the bronchopulmonary dysplasia group. However, the expression of genes depended on both factors: immaturity and disease severity. The most significantly down-regulated pathway was the T cell receptor signaling pathway. Conclusion The results of the whole genome expression study revealed alteration of the expression of nearly 10% of the genome in bronchopulmonary dysplasia patients.
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81
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Harijith A, Pendyala S, Reddy NM, Bai T, Usatyuk PV, Berdyshev E, Gorshkova I, Huang LS, Mohan V, Garzon S, Kanteti P, Reddy SP, Raj JU, Natarajan V. Sphingosine kinase 1 deficiency confers protection against hyperoxia-induced bronchopulmonary dysplasia in a murine model: role of S1P signaling and Nox proteins. THE AMERICAN JOURNAL OF PATHOLOGY 2013; 183:1169-1182. [PMID: 23933064 DOI: 10.1016/j.ajpath.2013.06.018] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Revised: 06/05/2013] [Accepted: 06/24/2013] [Indexed: 12/23/2022]
Abstract
Bronchopulmonary dysplasia of the premature newborn is characterized by lung injury, resulting in alveolar simplification and reduced pulmonary function. Exposure of neonatal mice to hyperoxia enhanced sphingosine-1-phosphate (S1P) levels in lung tissues; however, the role of increased S1P in the pathobiological characteristics of bronchopulmonary dysplasia has not been investigated. We hypothesized that an altered S1P signaling axis, in part, is responsible for neonatal lung injury leading to bronchopulmonary dysplasia. To validate this hypothesis, newborn wild-type, sphingosine kinase1(-/-) (Sphk1(-/-)), sphingosine kinase 2(-/-) (Sphk2(-/-)), and S1P lyase(+/-) (Sgpl1(+/-)) mice were exposed to hyperoxia (75%) from postnatal day 1 to 7. Sphk1(-/-), but not Sphk2(-/-) or Sgpl1(+/-), mice offered protection against hyperoxia-induced lung injury, with improved alveolarization and alveolar integrity compared with wild type. Furthermore, SphK1 deficiency attenuated hyperoxia-induced accumulation of IL-6 in bronchoalveolar lavage fluids and NADPH oxidase (NOX) 2 and NOX4 protein expression in lung tissue. In vitro experiments using human lung microvascular endothelial cells showed that exogenous S1P stimulated intracellular reactive oxygen species (ROS) generation, whereas SphK1 siRNA, or inhibitor against SphK1, attenuated hyperoxia-induced S1P generation. Knockdown of NOX2 and NOX4, using specific siRNA, reduced both basal and S1P-induced ROS formation. These results suggest an important role for SphK1-mediated S1P signaling-regulated ROS in the development of hyperoxia-induced lung injury in a murine neonatal model of bronchopulmonary dysplasia.
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Affiliation(s)
- Anantha Harijith
- Department of Pediatrics, University of Illinois at Chicago, Chicago, Illinois; Department of Medicine, University of Illinois at Chicago, Chicago, Illinois.
| | - Srikanth Pendyala
- Department of Pharmacology, University of Illinois at Chicago, Chicago, Illinois; Institute for Personalized Respiratory Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Narsa M Reddy
- Department of Pediatrics, University of Illinois at Chicago, Chicago, Illinois
| | - Tao Bai
- Department of Pediatrics, University of Illinois at Chicago, Chicago, Illinois; Department of Pharmacology, University of Illinois at Chicago, Chicago, Illinois
| | - Peter V Usatyuk
- Department of Pharmacology, University of Illinois at Chicago, Chicago, Illinois; Institute for Personalized Respiratory Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Evgeny Berdyshev
- Department of Pharmacology, University of Illinois at Chicago, Chicago, Illinois; Institute for Personalized Respiratory Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Irina Gorshkova
- Department of Pharmacology, University of Illinois at Chicago, Chicago, Illinois; Institute for Personalized Respiratory Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Long Shuang Huang
- Department of Pharmacology, University of Illinois at Chicago, Chicago, Illinois; Institute for Personalized Respiratory Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Vijay Mohan
- Department of Pharmacology, University of Illinois at Chicago, Chicago, Illinois; Institute for Personalized Respiratory Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Steve Garzon
- Department of Pathology, University of Illinois at Chicago, Chicago, Illinois
| | - Prasad Kanteti
- Department of Pharmacology, University of Illinois at Chicago, Chicago, Illinois; Institute for Personalized Respiratory Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Sekhar P Reddy
- Department of Pediatrics, University of Illinois at Chicago, Chicago, Illinois
| | - J Usha Raj
- Department of Pediatrics, University of Illinois at Chicago, Chicago, Illinois
| | - Viswanathan Natarajan
- Department of Medicine, University of Illinois at Chicago, Chicago, Illinois; Department of Pharmacology, University of Illinois at Chicago, Chicago, Illinois; Institute for Personalized Respiratory Medicine, University of Illinois at Chicago, Chicago, Illinois
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82
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Hadchouel A, Delacourt C. [Premature infants bronchopulmonary dysplasia: past and present]. REVUE DE PNEUMOLOGIE CLINIQUE 2013; 69:207-216. [PMID: 23867575 DOI: 10.1016/j.pneumo.2013.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Accepted: 05/20/2013] [Indexed: 06/02/2023]
Abstract
Bronchopulmonary dysplasia (BPD) is the most common chronic respiratory disease in premature infants. BPD was first described by Northway in 1967 as a chronic respiratory condition that developed in premature infants exposed to mechanical ventilation and high oxygen supplementation. DBP is currently defined by the need for supplemental oxygen at 28 days of life (mild BPD) and at the 36 weeks of post-menstrual age (moderate and severe BPD). With the advances of neonatal care, epidemiological characteristics and mechanisms of the disease as well as pathological characteristics and clinical course have profoundly changed within the last two decades, but still no effective curative treatment exists and BPD continue to occur among 10 to 20% of premature infants. Furthermore, BPD is a significant source of respiratory and neuro-cognitive morbidities. Thus, its treatment makes a considerable demand on health services. Regarding its pathophysiological mechanisms, it is now established that BPD is a complex disease combining genetic susceptibility and environmental injuries. The identification of genetic variants involved in BPD is a potential source of innovative development in terms of diagnosis and treatment. Indeed, no curative or effective prophylactic therapeutic exists and BPD treatment is currently symptomatic.
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Affiliation(s)
- A Hadchouel
- Service de pneumologie et d'allergologie pédiatriques, hôpital universitaire Necker-Enfants-Malades, 149-161, rue de Sèvres, 75043 Paris cedex 15, France.
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83
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Latini G, De Felice C, Giannuzzi R, Del Vecchio A. Survival rate and prevalence of bronchopulmonary dysplasia in extremely low birth weight infants. Early Hum Dev 2013; 89 Suppl 1:S69-73. [PMID: 23809356 DOI: 10.1016/s0378-3782(13)70020-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Bronchopulmonary dysplasia (BPD) continues to represent a significant cause of morbidity among survivors of severe prematurity in the NICU. The increasing prevalence of BPD over the decades has been suggested to be related to the increased survival of extremely low birthweight infants. AIMS To evaluate differences in prevalence of BPD (BPD28d and BPD36wk) and as a function of survival rate in extremely low birth weight (ELBW) infants over time, and to explore its relationship with known associated risk factors. METHODS Survival rate and prevalence of oxygen-dependency =28 days (BPD28d) and oxygen-dependency =36 weeks postmenstrual age (BPD36wk) were evaluated in ELBW newborns (mean gestational age: 27.12.2 weeks; mean birth weight: 817142 g) consecutively admitted to the Brindisi NICU over the last 26 years. Two arbitrarily chosen time periods were compared: Period 1: July 1st, 1986 to June 30, 2002 vs. Period 2: July 1st, 2002 to December 31, 2012. Analyzed variables included gestational age, birth weight, intubation time, hours of O2 administration, NCPAP, and use of surfactant. Differences between the time periods were assessed by chi-square statistics, Fisher's tests or Mann-Whitney test, as appropriate. A two-tailed p value <0.05 was considered to indicate statistical significance. RESULTS Survival rate of ELBW infants over the examined time periods dramatically improved from 42.3% to 72.6% (p < 0.0001), whereas changes in the prevalence of BPD28d and BPD36wk were not statistically significant (30.5% vs. 39.3%, p = 0.2137 and 5.5% vs. 13.1%, p = 0.1452, respectively). Likewise, BPD severity was not significantly different between the two time periods (p = 0.1635). Gestational age and birth weight of surviving neonates did not significantly change between the two time periods (p = 0.8050 and p = 0.6986, respectively), whereas significantly increased intubation time (median values: 144 hours vs. 33 hours, p <0.0001) and use of exogenous surfactant (89.3% vs. 48.6%, p < 0.0001) was evidenced for the second time period, as well as NCPAP (median values: 600 hours vs. 377 hours, p = 0.0005). A statistically non-significant trend for a prolonged O2 administration in period 2 (p = 0.0850) was also observed. CONCLUSION Our findings indicate that a significantly increased survival is not necessarily associated with a significant difference in the prevalence of BPD among ELBW infants.
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Affiliation(s)
- Giuseppe Latini
- Division of Neonatology, Perrino Hospital, Brindisi, Italy; Clinical Physiology Institute (IFC-CNR), National Research Council of Italy, Lecce Section, Italy
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James ML, Ross AC, Nicola T, Steele C, Ambalavanan N. VARA attenuates hyperoxia-induced impaired alveolar development and lung function in newborn mice. Am J Physiol Lung Cell Mol Physiol 2013; 304:L803-12. [PMID: 23585226 DOI: 10.1152/ajplung.00257.2012] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We have recently shown that a combination of vitamin A (VA) and retinoic acid (RA) in a 10:1 molar ratio (VARA) synergistically increases lung retinoid content in newborn rodents, more than either VA or RA alone in equimolar amounts. We hypothesized that the increase in lung retinoids would reduce oxidative stress and proinflammatory cytokines, resulting in attenuation of alveolar simplification and abnormal lung function in hyperoxia-exposed newborn mice. Newborn C57BL/6 mice were exposed to 85% O₂ (hyperoxia) or air (normoxia) for 7 or 14 days from birth and given vehicle or VARA every other day. Lung retinol content was measured by HPLC, function was assessed by flexiVent, and development was evaluated by radial alveolar counts, mean linear intercept, and secondary septal crest density. Mediators of oxidative stress, inflammation, and alveolar development were evaluated in lung homogenates. We observed that VARA increased lung retinol stores and attenuated hyperoxia-induced alveolar simplification while increasing lung compliance and lowering resistance. VARA attenuated hyperoxia-induced increases in DNA damage and protein oxidation accompanied with a reduction in nuclear factor (erythroid-derived 2)-like 2 protein but did not alter malondialdehyde adducts, nitrotyrosine, or myeloperoxidase concentrations. Interferon-γ and macrophage inflammatory protein-2α mRNA and protein increased with hyperoxia, and this increase was attenuated by VARA. Our study suggests that the VARA combination may be a potential therapeutic strategy in conditions characterized by VA deficiency and hyperoxia-induced lung injury during lung development, such as bronchopulmonary dysplasia in preterm infants.
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Affiliation(s)
- Masheika L James
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL 35249, USA
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85
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Hagood JS, Ambalavanan N. Systems biology of lung development and regeneration: current knowledge and recommendations for future research. WILEY INTERDISCIPLINARY REVIEWS-SYSTEMS BIOLOGY AND MEDICINE 2013; 5:125-33. [PMID: 23293056 DOI: 10.1002/wsbm.1205] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The lung begins as a simple outpouching of the foregut and develops by stages into a highly complex organ, the proper function of which is essential to life for terrestrial mammals. Interruption of normal lung development can result in death or chronic disease. Conversely, repair after lung injury, as well as many acquired diseases, involves recapitulation, often aberrant, of developmental pathways. The principal paradigms in lung development are branching morphogenesis and alveolar septation, but others, such as vasculogenesis, are critical. These are partially understood at the level of cellular differentiation and molecular signaling, but a true systems biology analysis of lung development and lung repair/regeneration, including bioinformatics analysis and integration of data from unbiased and complementary '-omics' level studies, is still lacking. The past decade has seen increasing numbers of genomic, proteomic, metabolomics, and epigenomic studies of lung development and lung remodeling. In many cases, these studies have confirmed the importance of pathways uncovered painstakingly through single-molecule approaches, but they have also uncovered novel and unexpected pathways and new paradigms such as noncoding RNA. Future studies will need to combine data from multiple repositories and apply novel mathematical and computational models in order to establish a systems-level understanding of this remarkable organ.
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Affiliation(s)
- James S Hagood
- Division of Respiratory Medicine, Department of Pediatrics, University of California-San Diego and Rady Children's Hospital of San Diego, La Jolla, CA, USA.
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86
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Gebb SA, Decoux A, Waggoner A, Wilson GL, Gillespie MN. Mitochondrial DNA damage mediates hyperoxic dysmorphogenesis in rat fetal lung explants. Neonatology 2013; 103:91-7. [PMID: 23154780 PMCID: PMC3568246 DOI: 10.1159/000342632] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Accepted: 08/14/2012] [Indexed: 11/19/2022]
Abstract
BACKGROUND Numerous studies in cultured cells indicate that damage to mitochondrial DNA (mtDNA) dictates cellular responses to oxidant stress, yet the consequences of mtDNA damage have not been studied directly in the preterm lung. OBJECTIVE We sought to determine whether hyperoxia-induced fetal lung dysmorphogenesis is linked to mtDNA damage and establish mtDNA repair as a potential therapeutic approach for treating lung dysplasia in the preterm neonate. METHODS Hyperoxia-induced mtDNA damage was assessed by quantitative alkaline gel electrophoresis in normoxic (3% O2) and hyperoxic (21% O2) fetal rat lung explants. A fusion protein construct targeting the DNA repair enzyme endonuclease III (Endo III) to the mitochondria was used to augment mtDNA repair. Fetal lung branching and surfactant protein C (SFPTC) were assessed in these tissues. RESULTS Hyperoxia induced mtDNA damage in lung explants and was accompanied by impaired branching morphogenesis and decreased SFPTC mRNA expression. Treatment of lung explants with Endo III fusion protein prevented hyperoxia-induced mtDNA damage and restored normal branching morphogenesis and SFPTC mRNA expression. CONCLUSION These findings support the concept that mtDNA governs cellular responses to oxidant stress in the fetal lung and suggest that modulation of mtDNA repair is a potential pharmacologic strategy in the prevention of hyperoxic lung injury.
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Affiliation(s)
- Sarah A Gebb
- Department of Cell Biology and Neuroscience, University of South Alabama College of Medicine, Mobile, AL 36688, USA.
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87
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Ambalavanan N, Stanishevsky A, Bulger A, Halloran B, Steele C, Vohra Y, Matalon S. Titanium oxide nanoparticle instillation induces inflammation and inhibits lung development in mice. Am J Physiol Lung Cell Mol Physiol 2012; 304:L152-61. [PMID: 23220372 DOI: 10.1152/ajplung.00013.2012] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Nanoparticles are used in an increasing number of biomedical, industrial, and food applications, but their safety profiles in developing organisms, including the human fetus and infant, have not been evaluated. Titanium oxide (TiO(2)) nanoparticles, which are commonly used in cosmetics, sunscreens, paints, and food, have been shown to induce emphysema and lung inflammation in adult mice. We hypothesized that exposure of newborn mice to TiO(2) would induce lung inflammation and inhibit lung development. C57BL/6 mice were exposed to TiO(2) (anatase; 8-10 nm) nanoparticles by intranasal instillation as a single dose on postnatal day 4 (P4) or as three doses on postnatal days 4, 7, and 10 (each dose = 1 μg/g body wt). Measurements of lung function (compliance and resistance), development (morphometry), inflammation (histology; multiplex analysis of bronchoalveolar lavage fluid for cytokines; PCR array and multiplex analysis of lung homogenates for cytokines) was performed on postnatal day 14. It was observed that a single dose of TiO(2) nanoparticles led to inflammatory cell influx, and multiple doses led to increased inflammation and inhibition of lung development without significant effects on lung function. Macrophages were noted to take up the TiO(2) nanoparticles, followed by polymorphonuclear infiltrate. Multiple cytokines and matrix metalloproteinase-9 were increased in lung homogenates, and VEGF was reduced. These results suggest that exposure of the developing lung to nanoparticles may lead to ineffective clearance by macrophages and persistent inflammation with resulting effects on lung development and may possibly impact the risk of respiratory disorders in later life.
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Affiliation(s)
- Namasivayam Ambalavanan
- Department of Pediatrics, University of Alabama at Birmingham, 176F Suite 9380, 619 South 20 St., Birmingham, AL 35233, USA.
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Alphonse RS, Rajabali S, Thébaud B. Lung injury in preterm neonates: the role and therapeutic potential of stem cells. Antioxid Redox Signal 2012; 17:1013-40. [PMID: 22400813 DOI: 10.1089/ars.2011.4267] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Continuous improvements in perinatal care have allowed the survival of ever more premature infants, making the task of protecting the extremely immature lung from injury increasingly challenging. Premature infants at risk of developing chronic lung disease or bronchopulmonary dysplasia (BPD) are now born at the late canalicular stage of lung development, just when the airways become juxtaposed to the lung vasculature and when gas-exchange becomes possible. Readily available strategies, including improved antenatal management (education, regionalization, steroids, and antibiotics), together with exogenous surfactant and exclusive/early noninvasive ventilatory support, will likely decrease the incidence/severity of BPD over the next few years. Nonetheless, because of the extreme immaturity of the developing lung, the extent to which disruption of lung growth after prematurity and neonatal management lead to an earlier or more aggravated decline in respiratory function in later life is a matter of concern. Consequently, much more needs to be learned about the mechanisms of lung development, injury, and repair. Recent insight into stem cell biology has sparked interest for stem cells to repair damaged organs. This review summarizes the exciting potential of stem cell-based therapies for lung diseases in general and BPD in particular.
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89
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Collins JJP, Kuypers E, Nitsos I, Jane Pillow J, Polglase GR, Kemp MW, Newnham JP, Cleutjens JP, Frints SGM, Kallapur SG, Jobe AH, Kramer BW. LPS-induced chorioamnionitis and antenatal corticosteroids modulate Shh signaling in the ovine fetal lung. Am J Physiol Lung Cell Mol Physiol 2012; 303:L778-87. [PMID: 22962010 DOI: 10.1152/ajplung.00280.2011] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Chorioamnionitis and antenatal corticosteroids mature the fetal lung functionally but disrupt late-gestation lung development. Because Sonic Hedgehog (Shh) signaling is a major pathway directing lung development, we hypothesized that chorioamnionitis and antenatal corticosteroids modulated Shh signaling, resulting in an altered fetal lung structure. Time-mated ewes with singleton ovine fetuses received an intra-amniotic injection of lipopolysaccharide (LPS) and/or maternal intramuscular betamethasone 7 and/or 14 days before delivery at 120 days gestational age (GA) (term = 150 days GA). Intra-amniotic LPS exposure decreased Shh mRNA levels and Gli1 protein expression, which was counteracted by both betamethasone pre- or posttreatment. mRNA and protein levels of fibroblast growth factor 10 and bone morphogenetic protein 4, which are important mediators of lung development, increased 2-fold and 3.5-fold, respectively, 14 days after LPS exposure. Both 7-day and 14-day exposure to LPS changed the mRNA levels of elastin (ELN) and collagen type I alpha 1 (Col1A1) and 2 (Col1A2), which resulted in fewer elastin foci and increased collagen type I deposition in the alveolar septa. Corticosteroid posttreatment prevented the decrease in ELN mRNA and increased elastin foci and decreased collagen type I deposition in the fetal lung. In conclusion, fetal lung exposure to LPS was accompanied by changes in key modulators of lung development resulting in abnormal lung structure. Betamethasone treatment partially prevented the changes in developmental processes and lung structure. This study provides new insights into clinically relevant prenatal exposures and fetal lung development.
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Affiliation(s)
- Jennifer J P Collins
- Department of Pediatrics, School for Oncology and Developmental Biology, School for Mental Health and Neuroscience, Maastricht University Medical Center, The Netherlands
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90
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Bhaskaran M, Xi D, Wang Y, Huang C, Narasaraju T, Shu W, Zhao C, Xiao X, More S, Breshears M, Liu L. Identification of microRNAs changed in the neonatal lungs in response to hyperoxia exposure. Physiol Genomics 2012; 44:970-80. [PMID: 22911455 DOI: 10.1152/physiolgenomics.00145.2011] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Bronchopulmonary dysplasia (BPD) is a multifactorial chronic lung disease of premature infants. BPD can be attributed to the dysregulation of normal lung development due to ventilation and oxygen toxicity, resulting in pathologic complications of impaired alveolarization and vascularization. MicroRNAs (miRNA) are small noncoding RNAs that regulate gene expression posttranscriptionally and are implicated in diverse biological processes and diseases. The objectives of this study are to identify the changed miRNAs and their target genes in neonatal rat lungs in response to hyperoxia exposure. Using miRNA microarray and real-time PCR analyses, we found downregulation of five miRNAs, miR-342, miR-335, miR-150, miR-126*, and miR-151*, and upregulation of two miRNAs, miR-21 and miR-34a. Some of these miRNAs had the highest expression during embryonic and early postnatal development. DNA microarray analysis yielded several genes with conserved binding sites for these altered miRNAs. Glycoprotein nonmetastatic melanoma protein b (GPNMB) was experimentally verified as a target of miR-150. In summary, we identified seven miRNAs that were changed in hyperoxia-exposed neonatal lungs. These results provide a basis for deciphering the mechanisms involved in the spatial and temporal regulation of proteins that contribute to the pathogenesis of BPD.
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Affiliation(s)
- Manoj Bhaskaran
- The Lundberg-Kienlen Lung Biology and Toxicology Laboratory, Department of Physiological Sciences, Oklahoma State University, Stillwater, Oklahoma, OK 74078, USA
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91
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Hodges RJ, Jenkin G, Hooper SB, Allison B, Lim R, Dickinson H, Miller SL, Vosdoganes P, Wallace EM. Human amnion epithelial cells reduce ventilation-induced preterm lung injury in fetal sheep. Am J Obstet Gynecol 2012; 206:448.e8-15. [PMID: 22542124 DOI: 10.1016/j.ajog.2012.02.038] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Revised: 02/08/2012] [Accepted: 02/29/2012] [Indexed: 11/24/2022]
Abstract
OBJECTIVE The objective of the study was to explore whether human amnion epithelial cells (hAECs) can mitigate ventilation-induced lung injury. STUDY DESIGN An established in utero ovine model of ventilation-induced lung injury was used. At day 110 of gestation, singleton fetal lambs either had sham in utero ventilation (IUV) (n = 4), 12 hours of IUV alone (n = 4), or 12 hours of IUV and hAEC administration (n = 5). The primary outcome, structural lung injury, was assessed 1 week later. RESULTS Compared with sham controls, IUV alone was associated with significant lung injury: increased collagen (P = .03), elastin (P = .02), fibrosis (P = .02), and reduced secondary-septal crests (P = .009). This effect of IUV was significantly mitigated by the administration of hAECs: less collagen (P = .03), elastin (P = .04), fibrosis (P = .02), normalized secondary-septal crests (P = .02). The hAECs were immunolocalized within the fetal lung and had differentiated into type I and II alveolar cells. CONCLUSION The hAECs mitigate ventilation-induced lung injury and differentiated into alveolar cells in vivo.
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Abstract
The survival of extremely premature newborns has increased because of improvements in perinatal care. These infants however, are at high risk for chronic lung disease of prematurity or bronchopulmonary dysplasia (BPD). BPD, the most common complication in infants born before 28 weeks of gestation, is a multifactorial disease characterized by an arrest in alveolar development. Current preventive and curative therapies show limited efficacy. Cell-based therapies hold tremendous promise in regenerative medicine. Recent evidence suggests the therapeutic benefit of mesenchymal stem (or stromal) cells (MSC) in various diseases, including among others neurodegenerative, cardiovascular and respiratory disorders. Moreover, in an oxygen-induced BPD model, we and others recently demonstrated that bone marrow (BM) derived-MSCs efficiently prevent the arrest in lung development. In this review, we summarize the current knowledge regarding the therapeutic properties and mechanisms of action, specifically paracrine, of MSCs.
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Affiliation(s)
- P Waszak
- Service de Réanimation, Soins Intensifs et Médecine Néonatals, 10 Rue du Dr Heydenreich, 54042 Nancy cedex, France.
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Brew N, Hooper SB, Allison BJ, Wallace MJ, Harding R. Injury and repair in the very immature lung following brief mechanical ventilation. Am J Physiol Lung Cell Mol Physiol 2011; 301:L917-26. [PMID: 21890511 DOI: 10.1152/ajplung.00207.2011] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Mechanical ventilation (MV) of very premature infants contributes to lung injury and bronchopulmonary dysplasia (BPD), the effects of which can be long-lasting. Little is currently known about the ability of the very immature lung to recover from ventilator-induced lung injury. Our objective was to determine the ability of the injured very immature lung to repair in the absence of continued ventilation and to identify potential mechanisms. At 125 days gestational age (days GA, 0.85 of term), fetal sheep were partially exposed by hysterotomy under anesthesia and aseptic conditions; they were intubated and ventilated for 2 h with an injurious MV protocol and then returned to the uterus to continue development. Necropsy was performed at either 1 day (short-term group, 126 days GA, n = 6) or 15 days (long-term group, 140 days GA, n = 5) after MV; controls were unventilated (n = 7-8). At 1 day after MV, lungs displayed signs of injury, including hemorrhage, disorganized elastin and collagen deposition in the distal airspaces, altered morphology, significantly reduced secondary septal crest density, and decreased airspace. Bronchioles had thickened epithelium with evidence of injury and sloughing. Relative mRNA levels of early response genes (connective tissue growth factor, cysteine-rich 61, and early growth response-1) and proinflammatory cytokines [interleukins (IL)-1β, IL-6, IL-8, tumor necrosis factor-α, and transforming growth factor-β] were not different between groups 1 day after MV. At 15 days after MV, lung structure was normal with no evidence of injury. We conclude that 2 h of MV induces severe injury in the very immature lung and that these lungs have the capacity to repair spontaneously in the absence of further ventilation.
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Affiliation(s)
- Nadine Brew
- Department of Anatomy and Developmental Biology, Monash University, Victoria, Australia.
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94
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Schmiedl A, Behrens J, Zscheppang K, Purevdorj E, von Mayersbach D, Liese A, Dammann CEL. Lipopolysaccharide-induced injury is more pronounced in fetal transgenic ErbB4-deleted lungs. Am J Physiol Lung Cell Mol Physiol 2011; 301:L490-9. [PMID: 21724861 DOI: 10.1152/ajplung.00131.2010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Pulmonary ErbB4 deletion leads to a delay in fetal lung development, alveolar simplification, and lung function disturbances in adult mice. We generated a model of intrauterine infection in ErbB4 transgenic mice to study the additive effects of antenatal LPS administration and ErbB4 deletion during fetal lung development. Pregnant mice were treated intra-amniotically with an LPS dose of 4 μg at E17 of gestation. Lungs were analyzed 24 h later. A significant influx of inflammatory cells was seen in all LPS-treated lungs. In heterozygote control lungs, LPS treatment resulted in a delay of lung morphogenesis characterized by a significant increase in the fraction of mesenchyme, a decrease in gas exchange area, and disorganization of elastic fibers. Surfactant protein (Sftp)b and Sftpc were upregulated, but mRNA of Sftpb and Sftpc was downregulated compared with non-LPS-treated controls. The mRNA of Sftpa1 and Sftpd was upregulated. In ErbB4-deleted lungs, the LPS effects were more pronounced, resulting in a further delay in morphological development, a more pronounced inflammation in the parenchyma, and a significant higher increase in all Sftp. The effect on Sftpb and Sftpc mRNA was somewhat different, resulting in a significant increase. These results imply a major role of ErbB4 in LPS-induced signaling in structural and functional lung development.
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Affiliation(s)
- Andreas Schmiedl
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
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Lee HS, Kim CK. Effect of recombinant IL-10 on cultured fetal rat alveolar type II cells exposed to 65%-hyperoxia. Respir Res 2011; 12:68. [PMID: 21609457 PMCID: PMC3114733 DOI: 10.1186/1465-9921-12-68] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Accepted: 05/24/2011] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND Hyperoxia plays an important role in the genesis of lung injury in preterm infants. Although alveolar type II cells are the main target of hyperoxic lung injury, the exact mechanisms whereby hyperoxia on fetal alveolar type II cells contributes to the genesis of lung injury are not fully defined, and there have been no specific measures for protection of fetal alveolar type II cells. OBJECTIVE The aim of this study was to investigate (a) cell death response and inflammatory response in fetal alveolar type II cells in the transitional period from canalicular to saccular stages during 65%-hyperoxia and (b) whether the injurious stimulus is promoted by creating an imbalance between pro- and anti-inflammatory cytokines and (c) whether treatment with an anti-inflammatory cytokine may be effective for protection of fetal alveolar type II cells from injury secondary to 65%-hyperoxia. METHODS Fetal alveolar type II cells were isolated on embryonic day 19 and exposed to 65%-oxygen for 24 h and 36 h. Cells in room air were used as controls. Cellular necrosis was assessed by lactate dehydrogenase-release and flow cytometry, and apoptosis was analyzed by TUNEL assay and flow cytometry, and cell proliferation was studied by BrdU incorporation. Release of cytokines including VEGF was analyzed by ELISA, and their gene expressions were investigated by qRT-PCR. RESULTS 65%-hyperoxia increased cellular necrosis, whereas it decreased cell proliferation in a time-dependent manner compared to controls. 65%-hyperoxia stimulated IL-8-release in a time-dependent fashion, whereas the anti-inflammatory cytokine, IL-10, showed an opposite response. 65%-hyperoxia induced a significant decrease of VEGF-release compared to controls, and similar findings were observed on IL-8/IL-10/VEGF genes expression. Preincubation of recombinant IL-10 prior to 65%-hyperoxia decreased cellular necrosis and IL-8-release, and increased VEGF-release and cell proliferation significantly compared to hyperoxic cells without IL-10. CONCLUSIONS The present study provides an experimental evidence that IL-10 may play a potential role in protection of fetal alveolar type II cells from injury induced by 65%-hyperoxia.
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Affiliation(s)
- Hyeon-Soo Lee
- Department of Pediatrics, Kangwon National University Hospital, Kangwon National University School of Medicine, 17-1 Hyoja3-dong, Chuncheon, Kangwon 200-947, South Korea
- Institute of Medical Sciences, Kangwon National University School of Medicine, 17-1 Hyoja3-dong, Chuncheon, Kangwon 200-947, South Korea
| | - Chun-Ki Kim
- Medical and Bio-Materials Research Center, Kangwon National University School of Medicine, 192-1 Hyoja2-dong, Chuncheon, Kangwon 200-701, South Korea
- Department of Molecular and Cellular Biochemistry, Kangwon National University School of Medicine, 192-1 Hyoja2-dong, Chuncheon, Kangwon 200-701, South Korea
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Vitamine A et poumon en développement : des enjeux à long terme. Rev Mal Respir 2011; 28:279-80. [DOI: 10.1016/j.rmr.2010.10.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2010] [Accepted: 10/14/2010] [Indexed: 11/17/2022]
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Kwinta P, Pietrzyk JJ. Preterm birth and respiratory disease in later life. Expert Rev Respir Med 2011; 4:593-604. [PMID: 20923339 DOI: 10.1586/ers.10.59] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Chronic respiratory diseases are a common complication of preterm birth, particularly among very immature infants or those suffering from bronchopulmonary dysplasia. Major progress in the treatment of preterm newborns has changed the pattern of late respiratory complications. The major respiratory problem in infancy and early childhood is respiratory exacerbations caused by infections (particularly viral ones), which need hospitalization. The symptoms become mild in school-age children; however, a group of children still present with chronic airway obstruction defined by recurrent episodes of wheezing and decreased lung function tests (decreased forced expiratory volume). For some preterm infants, particularly those with bronchopulmonary dysplasia, obstructive lung disease persists into adulthood. They are very likely to develop chronic obstructive pulmonary disease or similar disease later in life. In these patients, a program of lung function monitoring and pulmonary prophylaxis by means of elimination of specific risk factors in adulthood is advisable.
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98
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Lu HY, Shao GB, Li WB, Wang H. Effects of hyperoxia on transdifferentiation of primary cultured typeII alveolar epithelial cells from premature rats. In Vitro Cell Dev Biol Anim 2010; 47:64-72. [PMID: 21082284 DOI: 10.1007/s11626-010-9360-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2010] [Accepted: 10/19/2010] [Indexed: 10/18/2022]
Abstract
Hyperoxia exposure is a significant risk factor for the impaired alveolarization characteristic of bronchopulmonary dysplasia. Type II alveolar epithelial cells (AECIIs) may serve as "alveolar stem cells" to transdifferentiate into type I alveolar epithelial cells (AECIs). Here, we show that hyperoxia is capable of inducing transdifferentiation of AECIIs in premature rats in vitro. Hyperoxia-induced transdifferentiation was characterized by typical morphological changes, inhibition of cellular proliferation, decline in expression rate of Ki67, accumulation of cells in the G(1) phase of the cell cycle, increased expression of AECI-specific protein aquaporin 5, and decreased expression of AECII-associated protein surfactant protein C. These results suggest that hyperoxia may induce transdifferentiation of AECIIs into AECIs and the transdifferentiation may be responsible for repairing early lung injury.
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Affiliation(s)
- Hong-Yan Lu
- Department of Pediatrics, the Affiliated Hospital of Jiangsu University, Zhenjiang, China.
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Abstract
During the development of the pulmonary vasculature in the fetus, many structural and functional changes occur to prepare the lung for the transition to air breathing. The development of the pulmonary circulation is genetically controlled by an array of mitogenic factors in a temporo-spatial order. With advancing gestation, pulmonary vessels acquire increased vasoreactivity. The fetal pulmonary vasculature is exposed to a low oxygen tension environment that promotes high intrinsic myogenic tone and high vasocontractility. At birth, a dramatic reduction in pulmonary arterial pressure and resistance occurs with an increase in oxygen tension and blood flow. The striking hemodynamic differences in the pulmonary circulation of the fetus and newborn are regulated by various factors and vasoactive agents. Among them, nitric oxide, endothelin-1, and prostaglandin I2 are mainly derived from endothelial cells and exert their effects via cGMP, cAMP, and Rho kinase signaling pathways. Alterations in these signaling pathways may lead to vascular remodeling, high vasocontractility, and persistent pulmonary hypertension of the newborn.
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Affiliation(s)
- Yuansheng Gao
- Department of Physiology and Pathophysiology, Peking University, Health Science Center, Beijing, China; and Department of Pediatrics, University of Illinois, College of Medicine at Chicago, Chicago, Illinois
| | - J. Usha Raj
- Department of Physiology and Pathophysiology, Peking University, Health Science Center, Beijing, China; and Department of Pediatrics, University of Illinois, College of Medicine at Chicago, Chicago, Illinois
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[The use of postnatal corticosteroid therapy in premature infants to prevent or treat bronchopulmonary dysplasia: current situation and recommendations]. Arch Pediatr 2010; 17:1480-7. [PMID: 20864322 DOI: 10.1016/j.arcped.2010.07.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2009] [Revised: 06/30/2010] [Accepted: 07/14/2010] [Indexed: 11/21/2022]
Abstract
In the last few years, several studies related to the benefit/risk balance of postnatal corticosteroids administered to premature neonates for prevention or treatment of bronchopulmonary dysplasia (BPD) have been published. These data encourage caution, given the risk of long-term adverse neurodevelopmental outcomes. In the meantime, the clinical profile of BPD has been altered based on the progress made in the pre- and postnatal care of premature infants. In 2006, a survey conducted in France in neonatal centers showed that corticosteroids were still frequently used (57% of the centers) following various protocols in very preterm-born infants for respiratory impairment. To promote safer practices and rational use of corticosteroids in the prevention and treatment of BPD in preterm-born neonates, we reviewed the available data in order to establish recommendations. Systemic administration of corticosteroids for prevention or treatment of BPD: (i) should not be used during the first 4 days of life; (ii) is not indicated in the first 3 weeks of life nor (iii) in extubated infants (nasal ventilation or oxygen therapy). The systemic administration of steroids can only be considered after the first 3 weeks of life in very preterm-born ventilator-dependent infants to facilitate extubation (or prevent reintubation related to the severity of BPD). Postnatal dexamethasone administration studied in several randomized clinical trials was shown to have an unfavorable benefit/risk profile, mainly because of the long-term adverse neurocognitive outcomes. Very few studies have been conducted with betamethasone in the postnatal period. According to sparse data, this drug might be as efficacious as dexamethasone, but its long-term risk profile is unknown. It should be noted that following prenatal administration, the benefit/risk profile of betamethasone is better than that of dexamethasone, especially with regard to neurocognitive development. Intravenous hydrocortisone administered at an early stage for the prevention of BPD is being evaluated and should not be administered in this indication, except within clinical trials approved by the ethics committee. No other corticosteroids have been evaluated in the postnatal period in respiratory indications. In conclusion, in the situations described above for which systemic corticosteroids could be justified, the use of betamethasone (or hydrocortisone) appears to be better. As usual, the lowest possible dose of corticosteroids should be administered for the shortest possible duration. The betamethasone-equivalent dose of 0.125 mg/kg/day for 3 days is deemed adequate. If inhaled, corticosteroid therapy may facilitate extubation. Neither its efficacy in respiratory diseases nor its long-term risk profile has been so far established.
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