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Harris C, Greenough A. The prevention and management strategies for neonatal chronic lung disease. Expert Rev Respir Med 2023; 17:143-154. [PMID: 36813477 DOI: 10.1080/17476348.2023.2183842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
INTRODUCTION Survival from even very premature birth is improving, but long-term respiratory morbidity following neonatal chronic lung disease (bronchopulmonary dysplasia (BPD)) has not reduced. Affected infants may require supplementary oxygen at home, because they have more hospital admissions particularly due to viral infections and frequent, troublesome respiratory symptoms requiring treatment. Furthermore, adolescents and adults who had BPD have poorer lung function and exercise capacity. AREAS COVERED Antenatal and postnatal preventative strategies and management of infants with BPD. A literature review was undertaken using PubMed and Web of Science. EXPERT OPINION There are effective preventative strategies which include caffeine, postnatal corticosteroids, vitamin A, and volume guarantee ventilation. Side-effects, however, have appropriately caused clinicians to reduce use of systemically administered corticosteroids to infants only at risk of severe BPD. Promising preventative strategies which need further research are surfactant with budesonide, less invasive surfactant administration (LISA), neurally adjusted ventilatory assist (NAVA) and stem cells. The management of infants with established BPD is under-researched and should include identifying the optimum form of respiratory support on the neonatal unit and at home and which infants will most benefit in the long term from pulmonary vasodilators, diuretics, and bronchodilators.
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Affiliation(s)
- Christopher Harris
- Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, UK
| | - Anne Greenough
- Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, UK
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Knockdown of LncRNA MALAT1 contributes to cell apoptosis via regulating NF-κB/CD80 axis in neonatal respiratory distress syndrome. Int J Biochem Cell Biol 2018; 104:138-148. [PMID: 30243953 DOI: 10.1016/j.biocel.2018.09.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 09/16/2018] [Accepted: 09/18/2018] [Indexed: 01/28/2023]
Abstract
Neonatal respiratory distress syndrome (NRDS) is a leading cause of morbidity in premature newborns and is a common reason for admission to the neonatal intensive care unit (NICU). Recent studies found that the pathogenesis of NRDS is not simply lung immaturity. Apoptosis is an essential process for the development and maturation of the lungs. In this study, we report a critical role of lncRNA MALAT1 in regulating CD80 transcription in the NRDS-associated apoptosis via binding with NF-κB. We first showed MALAT1 and CD80 were highly expressed in the peripheral blood mononuclear cells of NRDS with infection exposure. Then we found MALAT1 expressions were significantly increased by the treatment of LPS. We confirmed knockdown of MALAT1 promoted cell viability by CCK-8 assays, cell apoptosis by flow cytometric assays and cytoskeleton destruction by immunocytochemistry. We confirmed CD80 expression level was associated with cell apoptosis by affecting PARP and caspase-3. Then we demonstrated knockdown of MALAT1 promoted CD80 transcription in A549 cells. Furthermore, we confirmed that MALAT1 downregulated transcriptional expression of CD80 by interfering with NF-κB activation and disrupting its binding efficiency with the CD80 promoter in the cell nucleus. In conclusion, we first identified lncRNA MALAT1 as an important prognosis maker for NRDS patients. Most significantly, this study then demonstrated a novel regulatory function of knocked-down MALAT1 on the transcriptional level of CD80 by enhancing the binding of NF-κB to CD80 promoter. Since the interaction between MALAT1 and CD80 plays an essential role in the cell apoptosis of NRDS, our findings demonstrate the possibility of using MALAT1 as therapeutic target for treatment of NRDS, and extend existing knowledge about the molecular mechanism that underlies NRDS pathogensis.
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Darlow BA. One thing leads to another: Clinical research in neonatology. The 2015 RACP Montgomery Spencer Oration. J Paediatr Child Health 2016; 52:587-9. [PMID: 27333843 DOI: 10.1111/jpc.13197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 01/22/2016] [Indexed: 11/28/2022]
Affiliation(s)
- Brian A Darlow
- Department of Paediatrics, University of Otago Christchurch, Christchurch, New Zealand
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Abstract
Premature infants suffer significant respiratory morbidity during infancy with long-term negative consequences on health, quality of life, and health care costs. Enhanced susceptibility to a variety of infections and inflammation play a large role in early and prolonged lung disease following premature birth, although the mechanisms of susceptibility and immune dysregulation are active areas of research. This article reviews aspects of host-pathogen interactions and immune responses that are altered by preterm birth and that impact chronic respiratory morbidity in these children.
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Affiliation(s)
- Gloria S. Pryhuber
- Division of Neonatology, Department of Pediatrics, University of Rochester Medical Center, 601 Elmwood Avenue, Box 651, Rochester, NY 14642, USA,Department of Environmental Medicine, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester, NY 14642, USA,Division of Neonatology, Department of Pediatrics, University of Rochester Medical Center, 601 Elmwood Avenue, Box 651, Rochester, NY 14642.
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Robinson JW, Dando SJ, Nitsos I, Newnham J, Polglase GR, Kallapur SG, Pillow JJ, Kramer BW, Jobe AH, Payton D, Knox CL. Ureaplasma parvum serovar 3 multiple banded antigen size variation after chronic intra-amniotic infection/colonization. PLoS One 2013; 8:e62746. [PMID: 23638142 PMCID: PMC3637154 DOI: 10.1371/journal.pone.0062746] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Accepted: 03/28/2013] [Indexed: 12/21/2022] Open
Abstract
Ureaplasma species are the microorganisms most frequently associated with adverse pregnancy outcomes. The multiple banded antigen (MBA), a surface-exposed lipoprotein, is a key virulence factor of ureaplasmas. The MBA demonstrates size variation, which we have shown previously to be correlated with the severity of chorioamnion inflammation. We aimed to investigate U. parvum serovar 3 pathogenesis in vivo, using a sheep model, by investigating: MBA variation after long term (chronic) and short term (acute) durations of in utero ureaplasma infections, and the severity of chorioamnionitis and inflammation in other fetal tissues. Inocula of 2×107 colony-forming-units (CFU) of U. parvum serovar 3 (Up) or media controls (C) were injected intra-amniotically into pregnant ewes at one of three time points: day 55 (69d Up, n = 8; C69, n = 4); day 117 (7d Up, n = 8; C7, n = 2); and day 121 (3d Up, n = 8; C3, n = 2) of gestation (term = 145–150d). At day 124, preterm fetuses were delivered surgically. Samples of chorioamnion, fetal lung, and umbilical cord were: (i) snap frozen for subsequent ureaplasma culture, and (ii) fixed, embedded, sectioned and stained by haematoxylin and eosin stain for histological analysis. Selected fetal lung clinical ureaplasma isolates were cloned and filtered to obtain cultures from a single CFU. Passage 1 and clone 2 ureaplasma cultures were tested by western blot to demonstrate MBA variation. In acute durations of ureaplasma infection no MBA variants (3d Up) or very few MBA variants (7d Up) were present when compared to the original inoculum. However, numerous MBA size variants were generated in vivo (alike within contiguous tissues, amniotic fluid and fetal lung, but different variants were present within chorioamnion), during chronic, 69d exposure to ureaplasma infection. For the first time we have shown that the degree of ureaplasma MBA variation in vivo increased with the duration of gestation.
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Affiliation(s)
- James W. Robinson
- Institute of Health & Biomedical Innovation, Faculty of Health, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Samantha J. Dando
- Institute of Health & Biomedical Innovation, Faculty of Health, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Ilias Nitsos
- School of Women’s and Infants’ Health, The University of Western Australia, Perth, Western Australia, Australia
| | - John Newnham
- School of Women’s and Infants’ Health, The University of Western Australia, Perth, Western Australia, Australia
| | - Graeme R. Polglase
- School of Women’s and Infants’ Health, The University of Western Australia, Perth, Western Australia, Australia
| | - Suhas G. Kallapur
- School of Women’s and Infants’ Health, The University of Western Australia, Perth, Western Australia, Australia
- Department of Neonatology and Pulmonary Biology, Cincinnati Children’s Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - J. Jane Pillow
- School of Anatomy, Physiology and Human Biology, University of Western Australia, Perth, Western Australia, Australia
| | - Boris W. Kramer
- Department of Pediatrics, School of Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Alan H. Jobe
- School of Women’s and Infants’ Health, The University of Western Australia, Perth, Western Australia, Australia
- Department of Neonatology and Pulmonary Biology, Cincinnati Children’s Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Diane Payton
- Pathology Queensland, Royal Brisbane and Women’s Hospital, Herston, Queensland, Australia
| | - Christine L. Knox
- Institute of Health & Biomedical Innovation, Faculty of Health, Queensland University of Technology, Brisbane, Queensland, Australia
- * E-mail:
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Abstract
Prematurely born infants are at increased risk for infection throughout their hospitalization. Various developmentally regulated processes involving the central nervous and respiratory systems may be disrupted by the proinflammatory state associated with infection, resulting in an increased risk for death, chronic lung disease, and adverse neurodevelopmental outcome. This review summarizes the current understanding of the long-term impact of infection and/or inflammation in preterm infants, including the risks associated with perinatal infection, early-onset sepsis, late-onset sepsis, and necrotizing enterocolitis.
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Affiliation(s)
- Ira Adams-Chapman
- Division of Neonatology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30303, USA.
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Wright CJ, Kirpalani H. Targeting inflammation to prevent bronchopulmonary dysplasia: can new insights be translated into therapies? Pediatrics 2011; 128:111-26. [PMID: 21646264 PMCID: PMC3124103 DOI: 10.1542/peds.2010-3875] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Bronchopulmonary dysplasia (BPD) frequently complicates preterm birth and leads to significant long-term morbidity. Unfortunately, few therapies are known to effectively prevent or treat BPD. Ongoing research has been focusing on potential therapies to limit inflammation in the preterm lung. In this review we highlight recent bench and clinical research aimed at understanding the role of inflammation in the pathogenesis of BPD. We also critically assess currently used therapies and promising developments in the field.
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Affiliation(s)
- Clyde J. Wright
- Division of Neonatology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; ,Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania; and
| | - Haresh Kirpalani
- Division of Neonatology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; ,Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania; and ,Department of Clinical Epidemiology, McMaster University, Hamilton, Ontario, Canada
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Ballard HO, Shook LA, Bernard P, Anstead MI, Kuhn R, Whitehead V, Grider D, Crawford TN, Hayes D. Use of azithromycin for the prevention of bronchopulmonary dysplasia in preterm infants: a randomized, double-blind, placebo controlled trial. Pediatr Pulmonol 2011; 46:111-8. [PMID: 20963840 DOI: 10.1002/ppul.21352] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2010] [Revised: 07/08/2010] [Accepted: 07/16/2010] [Indexed: 01/01/2023]
Abstract
OBJECTIVE Since preventive therapies for bronchopulmonary dysplasia (BPD) are limited we treated preterm infants with azithromycin to decrease the incidence of BPD. METHODS Infants less than 1,250 g birth weight were randomized to azithromycin or placebo within 12 hr of beginning mechanical ventilation and within 72 hr of birth. The treatment group received azithromycin 10 mg/kg/day for 7 days followed by 5 mg/kg/day for a maximum of 6 weeks. Aspirates were collected during the study to assay for Ureaplasma. The primary endpoints were incidence of BPD or mortality. (Clinical Trials Identifier: NCT00319956.) RESULTS A total of 220 infants were enrolled (n=111 azithromycin, and 109 placebo). Mortality was 18% for the azithromycin group versus 22% for the placebo group (P = 0.45). Incidence of BPD was 76% for the azithromycin group versus 84% for the placebo group (P=0.2). The multiple logistic regression analysis demonstrated an odds ratio of 0.46 decrease in the chance of developing BPD or death for the azithromycin group, but was not statistically significant. The incidence of BPD in the Ureaplasma subgroup was 73% in the azithromycin group versus 94% in the placebo group (P=0.03). Analysis of patients in the Ureaplasma subgroup only, using the exact logistic model demonstrated a decrease in BPD or death in the azithromycin group with an estimated odds ratio of 0.026 (0.001-0.618, 95% confidence interval). CONCLUSIONS Routine use of azithromycin therapy for the prevention of BPD cannot be recommended. The early treatment of Ureaplasma colonized/infected patients might be beneficial, but a larger multi-centered trial is required to assess this more definitively.
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Been JV, Rours IG, Kornelisse RF, Jonkers F, de Krijger RR, Zimmermann LJ. Chorioamnionitis alters the response to surfactant in preterm infants. J Pediatr 2010; 156:10-15.e1. [PMID: 19833352 DOI: 10.1016/j.jpeds.2009.07.044] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Revised: 06/18/2009] [Accepted: 07/15/2009] [Indexed: 11/24/2022]
Abstract
OBJECTIVE To study the association between antenatal exposure to chorioamnionitis and the neonatal response to surfactant. STUDY DESIGN Prospective observational cohort of 301 preterm infants of gestational age < or = 32.0 weeks, 146 of whom received surfactant according to standardized criteria. Fraction of inspired oxygen (FiO(2)) requirement (using analysis of variance) and time to extubation (using Kaplan-Meier and Cox regression analyses) were compared between groups based on the presence of histological chorioamnionitis (HC) with or without fetal involvement (HC-, n = 88; HC + F-, n = 25; HC + F+, n = 33) and between infants who developed bronchopulmonary dysplasia (BPD) or died (n = 57) and BPD-free survivors (n = 89). Multiple logistic regression was performed to investigate the association between HC and BPD. RESULTS Compared with HC- infants, HC + F+ infants had significantly greater FiO(2) requirement and prolonged time to extubation postsurfactant, not accounted for by differences in gestational age and birth weight. Infants with BPD/death had a strikingly similar pattern of increased FiO(2) requirement postsurfactant. Moreover, in infants who received surfactant, HC + F+ status was associated with increased risk for BPD (odds ratio [OR] = 3.40; 95% confidence interval [CI] = 1.02-11.3; P = .047) and for BPD/death (OR = 2.72; 95% CI = 1.00-7.42; P = .049). CONCLUSIONS An impaired surfactant response was observed in preterm infants with severe chorioamnionitis and may be involved in the association between chorioamnionitis, mechanical ventilation, and the development of BPD.
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Affiliation(s)
- Jasper V Been
- Department of Paediatrics, School for Oncology and Developmental Biology (GROW), Maastricht University Medical Centre, Maastricht, The Netherlands.
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Abstract
For nearly 100 y, pediatricians have regularly used oxygen to treat neonatal and childhood diseases. During this time, it has become clear that oxygen is toxic and that overzealous use can lead to significant morbidity. As we have learned more about the appropriate clinical indications for oxygen therapy, studies at the bench have begun to elucidate the molecular mechanisms by which cells respond to hyperoxia. In this review, we discuss transcription factors whose activity is regulated by oxygen, including nuclear factor, erythroid 2-related factor 2 (Nrf2), activator protein 1 (AP-1), p53, nuclear factor kappaB (NF-kappaB), signal transducers and activators of transcription protein (STAT), and ccat/enhancer binding protein (CEBP). Special attention is paid to the mechanisms by which hyperoxia affects these transcription factors in the lung. Finally, we identify downstream targets of these transcription factors, with a focus on heme oxygenase-1. A better understanding of how oxygen affects various signaling pathways could lead to interventions aimed at preventing hyperoxic injury.
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Affiliation(s)
- Clyde J Wright
- Division of Neonatology, Children's Hospital of Philadelphia, 34th and Civic Center Blvd., Philadelphia, PA 19104, USA
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Cheah FC, Pillow JJ, Kramer BW, Polglase GR, Nitsos I, Newnham JP, Jobe AH, Kallapur SG. Airway inflammatory cell responses to intra-amniotic lipopolysaccharide in a sheep model of chorioamnionitis. Am J Physiol Lung Cell Mol Physiol 2008; 296:L384-93. [PMID: 19118089 DOI: 10.1152/ajplung.90547.2008] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Chorioamnionitis, a risk factor for bronchopulmonary dysplasia in preterm infants, causes an influx of inflammatory cells into the fetal lung. Using a fetal sheep model, we evaluated the time course of activation, functional maturity, and apoptosis of the leukocytes recruited to the fetal air spaces by lipopolysaccharide (LPS). Time-mated sheep were given intra-amniotic injections with 10 mg of Escherichia coli LPS or saline 2 or 7 days before preterm delivery at 124 days of gestation (term is 150 days). Both neutrophils and monocytes in bronchoalveolar lavage fluid (BALF) had activated NF-kappaB after 2- and 7-day LPS exposures. These neutrophils and monocytes expressed the activation factor CD11b and the maturation factor PU.1 at 2 days, and increased PU.1 expression was detected in macrophages at 7 days. Leukocyte oxidative burst activity was greatest at 7 days. BALF lipid peroxidation increased fivefold at 2 days, while protein carbonyls increased eightfold at 7 days. Nitrative stress was not detected in the BALF, but leukocytes in the lung expressed nitric oxide synthase (NOS)II (inducible NOS). BALF leukocytes expressed the antioxidant peroxiredoxin V. Lung glutathione peroxidase was also increased with LPS exposure. There was minimal apoptosis of airway and lung leukocytes assessed by caspase-3 activation. Intra-amniotic LPS recruits leukocytes to the fetal air space that have a persistent activation. These results have implications for the pathogenesis of lung inflammatory disorders in the preterm.
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Affiliation(s)
- Fook-Choe Cheah
- Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio 45229-3039, USA
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Wright CJ, Zhuang T, La P, Yang G, Dennery PA. Hyperoxia-induced NF-kappaB activation occurs via a maturationally sensitive atypical pathway. Am J Physiol Lung Cell Mol Physiol 2008; 296:L296-306. [PMID: 19074556 DOI: 10.1152/ajplung.90499.2008] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
NF-kappaB activation is exaggerated in neonatal organisms after oxidant and inflammatory insults, but the reason for this and the downstream effects are unclear. We hypothesized that specific phosphorylation patterns of IkappaBalpha could account for differences in NF-kappaB activation in hyperoxia-exposed fetal and adult lung fibroblasts. After exposure to hyperoxia (>95% O(2)), nuclear NF-kappaB binding increased in fetal, but not adult, lung fibroblasts. Unique to fetal cells, phosphorylation of IkappaBalpha on tyrosine 42, rather than serine 32/36 as seen in TNF-alpha-exposed cells, preceded NF-kappaB nuclear translocation. In fetal cells stably transfected with an NF-kappaB-driven luciferase reporter, hyperoxia significantly suppressed reporter activity, in contrast to increased reporter activity after TNF-alpha incubation. Targeted gene profiling analysis showed that hyperoxia resulted in decreased expression of multiple genes, including proapoptotic factors. Transfection with a dominant-negative IkappaBalpha (Y42F), which cannot be phosphorylated on tyrosine 42, resulted in upregulation of multiple proapoptotic genes. In support of this finding, caspase-3 activity and DNA laddering were specifically increased in fetal lung fibroblasts expressing Y42F after exposure to hyperoxia. These data demonstrate a unique pathway of NF-kappaB activation in fetal lung fibroblasts after exposure to hyperoxia, whereby these cells are protected against apoptosis. Activation of this pathway in fetal cells may prevent the normal pattern of fibroblast apoptosis necessary for normal lung development, resulting in aberrant lung morphology in vivo.
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Affiliation(s)
- Clyde J Wright
- Division of Neonatology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
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Abstract
Inflammation is important in the development of bronchopulmonary dysplasia (BPD). Polymorphonuclear cells and macrophages and proinflammatory cytokines/chemokines denote early inflammation in clinical scenarios such as in utero inflammation with chorioamnionitis or initial lung injury associated with respiratory distress syndrome or ventilator-induced lung injury. The persistence and non-resolution of lung inflammation contributes greatly to BPD, including altering the lung's ability to repair, contributing to fibrosis, and inhibiting secondary septation, alveolarization, and normal vascular development. Further understanding of the role of inflammation in the pathogenesis of BPD, in particular, during the chronic inflammatory period, offers us the opportunity to develop inflammation-related prevention and treatment strategies of this disease that has long-standing consequences for very premature infants.
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Moss TJ, Knox CL, Kallapur SG, Nitsos I, Theodoropoulos C, Newnham JP, Ikegami M, Jobe AH. Experimental amniotic fluid infection in sheep: effects of Ureaplasma parvum serovars 3 and 6 on preterm or term fetal sheep. Am J Obstet Gynecol 2008; 198:122.e1-8. [PMID: 18166324 DOI: 10.1016/j.ajog.2007.06.065] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2006] [Revised: 03/16/2007] [Accepted: 06/28/2007] [Indexed: 10/22/2022]
Abstract
OBJECTIVE The objective of the study was to determine the effects in late gestation of Ureaplasma parvum serovar 3 colonization and the effects, preterm, of U. parvum serovar 6. STUDY DESIGN Ewes received an intraamniotic (i.a.) injection of U. parvum serovar 6 (20 x 10(6) colony-forming units [cfu]; n = 9), U. parvum serovar 3 (20 x 10(3) cfu; n = 6), vehicle (n = 10), or saline (n = 4) on day 80 of pregnancy (d). The lambs were delivered at 125 d (U. parvum serovar 6, n = 9; saline or media controls, n = 9) or 145 d (U. parvum serovar 3, n = 6; media controls, n = 5) for assessment of inflammation and lung maturation. RESULTS I.a. ureaplasmas caused histologic chorioamnionitis but not preterm delivery. Fetal lung epithelium was colonized with ureaplasmas at both gestational ages, and pulmonary interleukin-8 levels had doubled in the ureaplasma-colonized animals, compared with the controls at 145 d. Surfactant levels in bronchoalveolar lavage fluid had increased 8-fold and 2.5-fold at 125 and 145 d, respectively, after ureaplasma injection. CONCLUSION Fetal lung inflammation and altered development accompanies ureaplasma colonization, regardless of age at delivery.
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Aghai ZH, Kode A, Saslow JG, Nakhla T, Farhath S, Stahl GE, Eydelman R, Strande L, Leone P, Rahman I. Azithromycin suppresses activation of nuclear factor-kappa B and synthesis of pro-inflammatory cytokines in tracheal aspirate cells from premature infants. Pediatr Res 2007; 62:483-8. [PMID: 17667842 DOI: 10.1203/pdr.0b013e318142582d] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Nuclear factor-kappaB (NF-kappaB) plays a central role in regulating key proinflammatory mediators. The activation of NF-kappaB is increased in tracheal aspirate (TA) cells from premature infants developing bronchopulmonary dysplasia (BPD). We studied the effect of azithromycin (AZM) on the suppression of NF-kappaB activation and the synthesis of pro-inflammatory cytokines IL-6 and IL-8 by TA cells obtained from premature infants. Tracheal aspirate cells were stimulated with tumor necrosis factor-alpha (TNF-alpha) and incubated with AZM. The nuclear NF-kappaB-DNA binding activity, the levels of inhibitory kappaB-alpha (IkappaB-alpha) in the cytoplasmic fraction and IL-6 and IL-8 release in the cell culture media were measured. Stimulation of TA cells by TNF-alpha increased the activation of NF-kappaB, which was suppressed by the addition of AZM. Increased activation of NF-kappaB was also associated with increased levels of pro-inflammatory cytokines (IL-6 and IL-8). AZM significantly reduced the IL-6 and IL-8 production to the levels similar to control. TNF-alpha stimulation also increased the degradation of IkappaB-alpha, which was restored with the addition of AZM. Our data suggest that AZM therapy may be an effective alternative to steroids in reducing lung inflammation and prevention of BPD in ventilated premature infants.
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Affiliation(s)
- Zubair H Aghai
- Department of Pediatrics, Cooper University Hospital-Robert Wood Johnson Medical School, Camden, New Jersey 08103, USA.
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Abstract
Increasing evidence indicates that bronchopulmonary dysplasia (BPD) results, at least in part, from an imbalance between pro-inflammatory and anti-inflammatory mechanisms, with a persistent imbalance that favours pro-inflammatory mechanisms. The inflammatory response is characterised by an accumulation of neutrophils and macrophages in the airways and pulmonary tissue of preterm infants and, moreover, by an arsenal of pro-inflammatory mediators which affect the alveolar capillary unit and tissue integrity. As well as pro-inflammatory cytokines and toxic oxygen radicals, various lipid mediators as well as potent proteases may be responsible for acute lung injury. During the last decade it has become evident that multiple pre- and postnatal events contribute to the development of BPD in preterm infants. Chorioamnionitis and cytokine exposure in utero, plus sequential lung injury caused by postnatal resuscitation, oxygen toxicity, volu-, barotrauma and infection all lead to a pulmonary inflammatory response which is most probably associated with aberrant wound healing and an inhibition of alveolarisation as well as vascular development in the immature lungs of very preterm infants, causing the 'new BPD'.
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Affiliation(s)
- Christian P Speer
- University Children's Hospital, Josef-Schneider-Str. 2, 97080 Wuerzburg, Germany.
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18
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Abstract
PURPOSE OF REVIEW Recently antenatal infection and inflammation have received significant attention because of their potential role in promoting premature labour and in causing morbidity in preterm infants including the development of chronic lung disease of prematurity and cerebral white matter changes. This review highlights recent developments in this field. RECENT FINDINGS Recent reports have improved our understanding of the inflammatory responses to antenatal infection although questions remain about the exact relationship between antenatal infection and inflammation. Although microbial invasion of the intrauterine cavity is confirmed, strategies to prevent onset of premature labour have not been successful. The association between antenatal infection and development of chronic lung disease has been confirmed and many mechanisms further explored for development of chronic lung disease and cerebral white matter changes. Ureaplasma species have been revisited for their role in both preterm labour and neonatal morbidity, especially as modern molecular methods have eased their identification. SUMMARY Antenatal infection and inflammation are strongly implicated in the pathogenesis of preterm labour and in the development of neonatal morbidity, specifically chronic lung disease and white matter damage. Ureaplasma species are being increasingly studied for their role in these disorders. The challenge is to develop effective therapies to prevent these conditions.
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Affiliation(s)
- Nicola C Maxwell
- Department of Child Health, Cardiff University, Cardiff, United Kingdom
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Aghai ZH, Kumar S, Farhath S, Kumar MA, Saslow J, Nakhla T, Eydelman R, Strande L, Stahl G, Hewitt C, Nesin M, Rahman I. Dexamethasone suppresses expression of Nuclear Factor-kappaB in the cells of tracheobronchial lavage fluid in premature neonates with respiratory distress. Pediatr Res 2006; 59:811-5. [PMID: 16641216 DOI: 10.1203/01.pdr.0000219120.92049.b3] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Nuclear Factor-kappaB (NF-kappaB) plays a central role in regulating the key mediators of inflammation involved in acute lung injury. The anti-inflammatory effect of steroids by suppressing pro-inflammatory cytokines may be mediated by inhibition of transcription factor NF-kappaB. The objective of this study was to determine the effect of glucocorticoid therapy on the expression of NF-kappaB in the cells of tracheobronchial lavage fluid (TBLF) in premature neonates with respiratory distress. Nineteen premature neonates requiring mechanical ventilation and receiving glucocorticoids were enrolled. Their gestational age (mean +/- SD) was 25.0 +/- 1.2 wk, birth weight 714 +/- 105 g and age of starting dexamethasone was 33 +/- 15 d. Tracheobronchial lavage fluid was collected before and 48-72 h after starting dexamethasone. NF-kappaB expression was measured by immunocytochemistry using mouse MAb against the p65 subunit of NF-kappaB on cytospin slides. The percent of cells stained and the intensity staining index were significantly higher before starting dexamethasone compared with after steroid therapy. Localization of NF-kappaB was significantly decreased in the cytoplasm and nuclei of mononuclear cells after initiation of dexamethasone therapy. The concentration of IL-8 was also significantly lower after starting dexamethasone. In conclusion, dexamethasone suppressed the expression of NF-kappaB in the cytoplasm and nuclei of mononuclear cells and decreased levels of IL-8 in TBLF from premature neonates with respiratory distress. The anti-inflammatory effects of corticosteroids may be mediated through NF-kappaB.
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Affiliation(s)
- Zubair H Aghai
- Department of Pediatrics, Cooper University Hospital-Robert Wood Johnson Medical School, Camden, NJ 08103, USA.
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Chatila TA, Smith JB. NF-kappaB and the innate immune response in the respiratory distress syndrome of the newborn: commentary on the article by Cheah et al. on page 616. Pediatr Res 2005; 57:613-5. [PMID: 15774819 DOI: 10.1203/01.pdr.0000161703.33428.91] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Talal A Chatila
- Division of Neonatology, The David Geffen School of Medicine at the University of California at Los Angeles, MDCC 12-430; mail code 175217, 10833 Le Conte Avenue, Los Angeles CA 90095-1752.
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