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Bizzotto D, Dahl MJ, Veneroni C, Lavizzari A, Rebentisch A, Dawson E, Bowen S, Zuspan K, Yoder BA, Albertine KH, Dellacà RL. Impact of neonatal noninvasive resuscitation strategies on lung mechanics, tracheal pressure, and tidal volume in preterm lambs. Am J Physiol Lung Cell Mol Physiol 2024; 327:L203-L217. [PMID: 38771135 DOI: 10.1152/ajplung.00236.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 05/15/2024] [Accepted: 05/15/2024] [Indexed: 05/22/2024] Open
Abstract
This study investigated the relationship between three respiratory support approaches on lung volume recruitment during the first 2 h of postnatal life in preterm lambs. We estimated changes in lung aeration, measuring respiratory resistance and reactance by oscillometry at 5 Hz. We also measured intratracheal pressure in subsets of lambs. The first main finding is that sustained inflation (SI) applied noninvasively (Mask SI; n = 7) or invasively [endotracheal tube (ETT) SI; n = 6] led to similar rapid lung volume recruitment (∼6 min). In contrast, Mask continuous positive airway pressure (CPAP) without SI (n = 6) resuscitation took longer (∼30-45 min) to reach similar lung volume recruitment. The second main finding is that, in the first 15 min of postnatal life, the Mask CPAP without SI group closed their larynx during custom ventilator-driven expiration, leading to intratracheal positive end-expiratory pressure of ∼17 cmH2O (instead of 8 cmH2O provided by the ventilator). In contrast, the Mask SI group used the larynx to limit inspiratory pressure to ∼26 cmH2O (instead of 30 cmH2O provided by the ventilator). These different responses affected tidal volume, being larger in the Mask CPAP without SI group [8.4 mL/kg; 6.7-9.3 interquartile range (IQR)] compared to the Mask SI (5.0 mL/kg; 4.4-5.2 IQR) and ETT SI groups (3.3 mL/kg; 2.6-3.7 IQR). Distinct physiological responses suggest that spontaneous respiratory activity of the larynx of preterm lambs at birth can uncouple pressure applied by the ventilator to that applied to the lung, leading to unpredictable lung pressure and tidal volume delivery independently from the ventilator settings.NEW & NOTEWORTHY We compared invasive and noninvasive resuscitation on lambs at birth, including or not sustained inflation (SI). Lung volume recruitment was faster in those receiving SI. During noninvasive resuscitation, larynx modulation reduced tracheal pressure from that applied to the mask in lambs receiving SI, while it led to increased auto-positive end-expiratory pressure and very large tidal volumes in lambs not receiving SI. Our results highlight the need for individualizing pressures and monitoring tidal volumes during resuscitation at birth.
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Affiliation(s)
- Davide Bizzotto
- TechRes Lab, Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano University, Milan, Italy
| | - Mar Janna Dahl
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah, United States
| | - Chiara Veneroni
- TechRes Lab, Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano University, Milan, Italy
| | - Anna Lavizzari
- NICU, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Andrew Rebentisch
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah, United States
| | - Elaine Dawson
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah, United States
| | - Sydney Bowen
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah, United States
| | - Kaitlin Zuspan
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah, United States
| | - Bradley A Yoder
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah, United States
| | - Kurt H Albertine
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah, United States
| | - Raffaele L Dellacà
- TechRes Lab, Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano University, Milan, Italy
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2
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Pei J, Chen J. The influence of prenatal dexamethasone administration before scheduled full-term cesarean delivery on short-term adverse neonatal outcomes: a retrospective single-center cohort study. Front Pediatr 2024; 11:1323097. [PMID: 38274470 PMCID: PMC10808727 DOI: 10.3389/fped.2023.1323097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 12/13/2023] [Indexed: 01/27/2024] Open
Abstract
Objective There has been a gradual increase in the prevalence of cesarean section deliveries and more healthcare professionals are considering the prophylactic use of corticosteroids before planned full-term cesarean sections. However, the association between dexamethasone administration before full-term cesarean delivery and short-term adverse neonatal outcomes is unclear. This study analyzed the disparities in short-term adverse neonatal effects in neonates born via full-term elective cesarean delivery with or without antenatal dexamethasone treatment. Study design This single-center retrospective cohort study involved neonates aged 37-39 weeks. The primary neonatal outcomes included various short-term adverse events, including neonatal admission to the neonatal intensive care unit, neonatal access to the special care baby unit, transient neonatal respiratory distress, respiratory distress syndrome, and the requirement of intravenous antibiotics or ventilatory support. Multiple logistic regression analysis was used to assess the association between these outcomes and dexamethasone exposure while adjusting for covariates. Results Of the 543 neonates included in the study, 121 (22.2%) had been exposed to prenatal dexamethasone. When compared with the control group, the dexamethasone-exposed group exhibited significantly higher rates of transient neonatal respiratory distress, respiratory distress syndrome, administration of intravenous antibiotics, the need for ventilatory support, and longer duration of neonatal hospitalization (P < 0.05). The association between dexamethasone exposure and short-term adverse neonatal outcomes remained significant after adjusting for potential confounders (odds ratio: 12.76, 95% confidence interval: 6.9-23.62, P < 0.001). Conclusion The dexamethasone-exposed group had a higher likelihood of experiencing short-term adverse outcomes when compared with non-exposed neonates, suggesting that dexamethasone may have detrimental effects on infants delivered at full term. This implies the importance of exercising caution when contemplating the use of antenatal corticosteroids.
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Affiliation(s)
| | - Jiao Chen
- Department of Hepatobiliary Surgery, the First Affiliated Hospital of Chengdu Medical College, Xindu District, Chengdu, Sichuan Province, China
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3
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Zhao J, Ballard C, Cohen AJ, Ringham B, Zhao B, Wang H, Zuspan K, Rebentisch A, Locklear BA, Dahl M, Maschek JA, Cox JE, Joss-Moore LA. Postnatal growth restriction impairs rat lung structure and function. Anat Rec (Hoboken) 2023:10.1002/ar.25297. [PMID: 37515384 PMCID: PMC10822022 DOI: 10.1002/ar.25297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 07/08/2023] [Accepted: 07/13/2023] [Indexed: 07/30/2023]
Abstract
The negative impact of nutritional deficits in the development of bronchopulmonary dysplasia is well recognized, yet mechanisms by which nutrition alters lung outcomes and nutritional strategies that optimize development and protect the lung remain elusive. Here, we use a rat model to assess the isolated effects of postnatal nutrition on lung structural development without concomitant lung injury. We hypothesize that postnatal growth restriction (PGR) impairs lung structure and function, critical mediators of lung development, and fatty acid profiles at postnatal day 21 in the rat. Rat pups were cross-fostered at birth to rat dams with litter sizes of 8 (control) or 16 (PGR). Lung structure and function, as well as serum and lung tissue fatty acids, and lung molecular mediators of development, were measured. Male and female PGR rat pups had thicker airspace walls, decreased lung compliance, and increased tissue damping. Male rats also had increased lung elastance, increased lung elastin protein abundance, and lysol oxidase expression, and increased elastic fiber deposition. Female rat lungs had increased conducting airway resistance and reduced levels of docosahexaenoic acid in lung tissue. We conclude that PGR impairs lung structure and function in both male and female rats, with sex-divergent changes in lung molecular mediators of development.
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Affiliation(s)
- James Zhao
- Department of Pediatrics, University of Utah, Salt Lake City, Utah, USA
| | - Craig Ballard
- Department of Pediatrics, University of Utah, Salt Lake City, Utah, USA
| | - Adrienne J Cohen
- Department of Pediatrics, University of Utah, Salt Lake City, Utah, USA
| | - Ben Ringham
- Department of Pediatrics, University of Utah, Salt Lake City, Utah, USA
| | - Brooke Zhao
- Department of Pediatrics, University of Utah, Salt Lake City, Utah, USA
| | - Haimei Wang
- Department of Pediatrics, University of Utah, Salt Lake City, Utah, USA
| | - Katie Zuspan
- Department of Pediatrics, University of Utah, Salt Lake City, Utah, USA
| | - Andrew Rebentisch
- Department of Pediatrics, University of Utah, Salt Lake City, Utah, USA
| | - Brent A Locklear
- Department of Pediatrics, University of Utah, Salt Lake City, Utah, USA
| | - MarJanna Dahl
- Department of Pediatrics, University of Utah, Salt Lake City, Utah, USA
| | - J Alan Maschek
- Health Science Center Cores, University of Utah Health Sciences Center, Salt Lake City, Utah, USA
- Department of Biochemistry, University of Utah, Salt Lake City, Utah, USA
| | - James E Cox
- Health Science Center Cores, University of Utah Health Sciences Center, Salt Lake City, Utah, USA
- Department of Biochemistry, University of Utah, Salt Lake City, Utah, USA
| | - Lisa A Joss-Moore
- Department of Pediatrics, University of Utah, Salt Lake City, Utah, USA
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4
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Pilot dose-ranging of rhIGF-1/rhIGFBP-3 in a preterm lamb model of evolving bronchopulmonary dysplasia. Pediatr Res 2022; 93:1528-1538. [PMID: 36030318 PMCID: PMC9968819 DOI: 10.1038/s41390-022-02272-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 07/12/2022] [Accepted: 08/05/2022] [Indexed: 11/09/2022]
Abstract
BACKGROUND Low levels of insulin-like growth factor-1 (IGF-1) protein in preterm human infants are associated with bronchopulmonary dysplasia (BPD). We used our preterm lamb model of BPD to determine (1) dosage of recombinant human (rh) IGF-1 bound to binding protein-3 (IGFBP-3) to reach infant physiologic plasma levels; and (2) whether repletion of plasma IGF-1 improves pulmonary and cardiovascular outcomes. METHODS Group 1: normal, unventilated lambs from 128 days gestation through postnatal age 5 months defined normal plasma levels of IGF-1. Group 2: continuous infusion of rhIGF-1/rhIGFBP-3 (0.5, 1.5, or 4.5 mg/kg/day; n = 2) for 3 days in mechanically ventilated (MV) preterm lambs determined that 1.5 mg/kg/day dosage attained physiologic plasma IGF-1 concentration of ~125 ng/mL, which was infused in four more MV preterm lambs. RESULTS Group 1: plasma IGF-1 protein increased from ~75 ng/mL at 128 days gestation to ~220 ng/L at 5 months. Group 2: pilot study of the optimal dosage (1.5 mg/kg/day rhIGF-1/rhIGFBP-3) in six MV preterm lambs significantly improved some pulmonary and cardiovascular outcomes (p < 0.1) compared to six MV preterm controls. RhIGF-1/rhIGFBP-3 was not toxic to the liver, kidneys, or lungs. CONCLUSIONS Three days of continuous iv infusion of rhIGF-1/rhIGFBP-3 at 1.5 mg/kg/day improved some pulmonary and cardiovascular outcomes without toxicity. IMPACT Preterm birth is associated with rapid decreases in serum or plasma IGF-1 protein level. This decline adversely impacts the growth and development of the lung and cardiovascular system. For this pilot study, continuous infusion of optimal dosage of rhIGF-1/rhIGFBP-3 (1.5 mg/kg/day) to maintain physiologic plasma IGF-1 level of ~125 ng/mL during mechanical ventilation for 3 days statistically improved some structural and biochemical outcomes related to the alveolar formation that would favor improved gas exchange compared to vehicle-control. We conclude that 3 days of continuous iv infusion of rhIGF-1/rhIGFBP-3 improved some physiological, morphological, and biochemical outcomes, without toxicity, in mechanically ventilated preterm lambs.
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5
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Gilfillan M, Bhandari V. Moving Bronchopulmonary Dysplasia Research from the Bedside to the Bench. Am J Physiol Lung Cell Mol Physiol 2022; 322:L804-L821. [PMID: 35437999 DOI: 10.1152/ajplung.00452.2021] [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: 11/22/2022] Open
Abstract
Although advances in the respiratory management of extremely preterm infants have led to improvements in survival, this progress has not yet extended to a reduction in the incidence of bronchopulmonary dysplasia (BPD). BPD is a complex multifactorial condition that primarily occurs due to disturbances in the regulation of normal pulmonary airspace and vascular development. Preterm birth and exposure to invasive mechanical ventilation also compromises large airway development, leading to significant morbidity and mortality. Although both predisposing and protective genetic and environmental factors have been frequently described in the clinical literature, these findings have had limited impact on the development of effective therapeutic strategies. This gap is likely because the molecular pathways that underlie these observations are yet not fully understood, limiting the ability of researchers to identify novel treatments that can preserve normal lung development and/or enhance cellular repair mechanisms. In this review article, we will outline various well-established clinical observations whilst identifying key knowledge gaps that need to be filled with carefully designed pre-clinical experiments. We will address these issues by discussing controversial topics in the pathophysiology, the pathology and the treatment of BPD, including an evaluation of existing animal models that have been used to answer important questions.
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Affiliation(s)
- Margaret Gilfillan
- Division of Neonatology, St. Christopher's Hospital for Children/Drexel University College of Medicine, Philadelphia, PA
| | - Vineet Bhandari
- Division of Neonatology, The Children's Regional Hospital at Cooper/Cooper Medical School of Rowan University, Camden, NJ
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6
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Dahl MJ, Veneroni C, Lavizzari A, Bowen S, Emerson H, Rebentisch A, Dawson E, Summers K, Pettet L, Wang Z, Null DM, Yoder BA, Dellacà RL, Albertine KH. Early extubation to noninvasive respiratory support of former preterm lambs improves long-term respiratory outcomes. Am J Physiol Lung Cell Mol Physiol 2021; 321:L248-L262. [PMID: 34009031 DOI: 10.1152/ajplung.00051.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Invasive mechanical ventilation (IMV) and exposure to oxygen-rich gas during early postnatal life are contributing factors for long-term pulmonary morbidities faced by survivors of preterm birth and bronchopulmonary dysplasia. The duration of IMV that leads to long-term pulmonary morbidities is unknown. We compared two durations of IMV (3 h vs. 6 days) during the first 6-7 days of postnatal life in preterm lambs to test the hypothesis that minimizing the duration of IMV will improve long-term respiratory system mechanics and structural outcomes later in life. Moderately preterm (∼85% gestation) lambs were supported by IMV for either 3 h or 6 days before weaning from all respiratory support to become former preterm lambs. Respiratory system mechanics and airway reactivity were assessed monthly from 1 to 6 mo of chronological postnatal age by the forced oscillation technique. Quantitative morphological measurements were made for smooth muscle accumulation around terminal bronchioles and indices of alveolar formation. Minimizing IMV to 3 h led to significantly better (P < 0.05) baseline respiratory system mechanics and less reactivity to methacholine in the first 3 mo of chronological age (2 mo corrected age), significantly less (P < 0.05) accumulation of smooth muscle around peripheral resistance airways (terminal bronchioles), and significantly better (P < 0.05) alveolarization at the end of 5 mo corrected age compared with continuous IMV for 6 days. We conclude that limiting the duration of IMV following preterm birth of fetal lambs leads to better respiratory system mechanics and structural outcomes later in life.
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Affiliation(s)
- Mar Janna Dahl
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah
| | - Chiara Veneroni
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano University, Milan, Italy
| | - Anna Lavizzari
- U.O. di Neonatologia e Terapia Intensiva Neonatale, Department of Clinical Sciences and Community Health, University of Milan Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Sydney Bowen
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah
| | - Haleigh Emerson
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah
| | - Andrew Rebentisch
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah
| | - Elaine Dawson
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah
| | - Kyle Summers
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah
| | - Luke Pettet
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah
| | - Zhengming Wang
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah
| | - Donald M Null
- Division of Neonatology, University of California, Davis, California
| | - Bradley A Yoder
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah
| | - Raffaele L Dellacà
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano University, Milan, Italy
| | - Kurt H Albertine
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah
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7
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Liu M, Iosef C, Rao S, Domingo-Gonzalez R, Fu S, Snider P, Conway SJ, Umbach GS, Heilshorn SC, Dewi RE, Dahl MJ, Null DM, Albertine KH, Alvira CM. Transforming Growth Factor-induced Protein Promotes NF-κB-mediated Angiogenesis during Postnatal Lung Development. Am J Respir Cell Mol Biol 2021; 64:318-330. [PMID: 33264084 PMCID: PMC7909333 DOI: 10.1165/rcmb.2020-0153oc] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 10/29/2020] [Indexed: 12/23/2022] Open
Abstract
Pulmonary angiogenesis is a key driver of alveolarization. Our prior studies showed that NF-κB promotes pulmonary angiogenesis during early alveolarization. However, the mechanisms regulating temporal-specific NF-κB activation in the pulmonary vasculature are unknown. To identify mechanisms that activate proangiogenic NF-κB signaling in the developing pulmonary vasculature, proteomic analysis of the lung secretome was performed using two-dimensional difference gel electrophoresis. NF-κB activation and angiogenic function was assessed in primary pulmonary endothelial cells (PECs) and TGFBI (transforming growth factor-β-induced protein)-regulated genes identified using RNA sequencing. Alveolarization and pulmonary angiogenesis was assessed in wild-type and Tgfbi null mice exposed to normoxia or hyperoxia. Lung TGFBI expression was determined in premature lambs supported by invasive and noninvasive respiratory support. Secreted factors from the early alveolar, but not the late alveolar or adult lung, promoted proliferation and migration in quiescent, adult PECs. Proteomic analysis identified TGFBI as one protein highly expressed by the early alveolar lung that promoted PEC migration by activating NF-κB via αvβ3 integrins. RNA sequencing identified Csf3 as a TGFBI-regulated gene that enhances nitric oxide production in PECs. Loss of TGFBI in mice exaggerated the impaired pulmonary angiogenesis induced by chronic hyperoxia, and TGFBI expression was disrupted in premature lambs with impaired alveolarization. Our studies identify TGFBI as a developmentally regulated protein that promotes NF-κB-mediated angiogenesis during early alveolarization by enhancing nitric oxide production. We speculate that dysregulation of TGFBI expression may contribute to diseases marked by impaired alveolar and vascular growth.
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Affiliation(s)
- Min Liu
- Department of Pediatrics, Center for Excellence in Pulmonary Biology, and
| | - Cristiana Iosef
- Department of Pediatrics, Center for Excellence in Pulmonary Biology, and
| | - Shailaja Rao
- Department of Pediatrics, Center for Excellence in Pulmonary Biology, and
| | | | - Sha Fu
- Department of Pediatrics, Center for Excellence in Pulmonary Biology, and
- Liuyang People's Hospital, Hunan, China
| | - Paige Snider
- Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - Simon J Conway
- Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - Gray S Umbach
- Department of Pediatrics, Center for Excellence in Pulmonary Biology, and
- University of Texas Southwestern Medical School, Dallas, Texas; and
| | - Sarah C Heilshorn
- Department of Materials Science and Engineering, Stanford University, Stanford, California
| | - Ruby E Dewi
- Department of Materials Science and Engineering, Stanford University, Stanford, California
| | - Mar J Dahl
- Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah
| | - Donald M Null
- Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah
| | - Kurt H Albertine
- Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah
| | - Cristina M Alvira
- Department of Pediatrics, Center for Excellence in Pulmonary Biology, and
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8
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Lai SH, Xie YL, Chen ZQ, Chen R, Cai WH, Wu LC, Lin YF, Zheng YR. Non-invasive High-Frequency Oscillatory Ventilation as Initial Respiratory Support for Preterm Infants With Respiratory Distress Syndrome. Front Pediatr 2021; 9:792160. [PMID: 35096707 PMCID: PMC8793903 DOI: 10.3389/fped.2021.792160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Accepted: 12/17/2021] [Indexed: 11/13/2022] Open
Abstract
Objectives: The aim of this study was to investigate the safety and feasibility of nHFOV as initial respiratory support in preterm infants with RDS. Methods: This study retrospectively analyzed the clinical data of 244 premature infants with RDS who were treated in our hospital from January 2016 to January 2019 and divided into the nHFOV group (n = 115) and the BiPAP group (n = 129) based on the initial respiratory support method. Results: Respiratory outcomes showed that the rate of NIV failure during the first 72 hours of life in the nHFOV group was significantly lower than that in the BiPAP group. The time of NIV in the nHFOV group was significantly shorter than that in the BiPAP group. The time of supplemental oxygen in the nHFOV group was significantly shorter than that in the BiPAP group. The incidence of air leakage syndrome in the nHFOV group was significantly lower than that in the BiPAP group, and the length of hospital stay of the nHFOV group was also significantly shorter than that in the BiPAP group. Although the rate of infants diagnosed with BPD was similar between the two groups, the rate of severe BPD in the nHFOV group was significantly lower than that in the BiPAP group. Conclusion: This study showed that nHFOV as initial respiratory support for preterm infants with RDS was feasible and safe compared to BiPAP. Furthermore, nHFOV can reduce the need for IMV and reduce the incidence of severe BPD and air leak syndrome.
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Affiliation(s)
- Shu-Hua Lai
- Department of Neonatology, Fujian Maternity and Child Health Hospital, Affiliated Hospital of Fujian Medical University, Fuzhou, China.,Fujian Key Laboratory of Women and Children's Critical Diseases Research, Fujian Maternity and Child Health Hospital, Fuzhou, China
| | - Ying-Ling Xie
- Department of Neonatology, Fujian Maternity and Child Health Hospital, Affiliated Hospital of Fujian Medical University, Fuzhou, China.,Fujian Key Laboratory of Women and Children's Critical Diseases Research, Fujian Maternity and Child Health Hospital, Fuzhou, China
| | - Zhi-Qing Chen
- Department of Neonatology, Fujian Maternity and Child Health Hospital, Affiliated Hospital of Fujian Medical University, Fuzhou, China.,Fujian Key Laboratory of Women and Children's Critical Diseases Research, Fujian Maternity and Child Health Hospital, Fuzhou, China
| | - Rong Chen
- Department of Neonatology, Fujian Maternity and Child Health Hospital, Affiliated Hospital of Fujian Medical University, Fuzhou, China.,Fujian Key Laboratory of Women and Children's Critical Diseases Research, Fujian Maternity and Child Health Hospital, Fuzhou, China
| | - Wen-Hong Cai
- Department of Neonatology, Fujian Maternity and Child Health Hospital, Affiliated Hospital of Fujian Medical University, Fuzhou, China.,Fujian Key Laboratory of Women and Children's Critical Diseases Research, Fujian Maternity and Child Health Hospital, Fuzhou, China
| | - Luo-Cheng Wu
- Department of Neonatology, Fujian Maternity and Child Health Hospital, Affiliated Hospital of Fujian Medical University, Fuzhou, China.,Fujian Key Laboratory of Women and Children's Critical Diseases Research, Fujian Maternity and Child Health Hospital, Fuzhou, China
| | - Yun-Feng Lin
- Department of Neonatology, Fujian Maternity and Child Health Hospital, Affiliated Hospital of Fujian Medical University, Fuzhou, China.,Fujian Key Laboratory of Women and Children's Critical Diseases Research, Fujian Maternity and Child Health Hospital, Fuzhou, China.,Fujian Branch of Shanghai Children's Medical Center, Fuzhou, China.,Fujian Children's Hospital, Fuzhou, China
| | - Yi-Rong Zheng
- Department of Neonatology, Fujian Maternity and Child Health Hospital, Affiliated Hospital of Fujian Medical University, Fuzhou, China.,Fujian Key Laboratory of Women and Children's Critical Diseases Research, Fujian Maternity and Child Health Hospital, Fuzhou, China.,Fujian Branch of Shanghai Children's Medical Center, Fuzhou, China.,Fujian Children's Hospital, Fuzhou, China
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9
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Ke X, Xing B, Dahl MJ, Alvord J, McKnight RA, Lane RH, Albertine KH. Hippocampal epigenetic and insulin-like growth factor alterations in noninvasive versus invasive mechanical ventilation in preterm lambs. Pediatr Res 2021; 90:998-1008. [PMID: 33603215 PMCID: PMC7891485 DOI: 10.1038/s41390-020-01305-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 11/10/2020] [Accepted: 11/13/2020] [Indexed: 01/31/2023]
Abstract
BACKGROUND The brain of chronically ventilated preterm human infants is vulnerable to collateral damage during invasive mechanical ventilation (IMV). Damage is manifest, in part, by learning and memory impairments, which are hippocampal functions. A molecular regulator of hippocampal development is insulin-like growth factor 1 (IGF1). A gentler ventilation strategy is noninvasive respiratory support (NRS). We tested the hypotheses that NRS leads to greater levels of IGF1 messenger RNA (mRNA) variants and distinct epigenetic profile along the IGF1 gene locus in the hippocampus compared to IMV. METHODS Preterm lambs were managed by NRS or IMV for 3 or 21 days. Isolated hippocampi were analyzed for IGF1 mRNA levels and splice variants for promoter 1 (P1), P2, and IGF1A and 1B, DNA methylation in P1 region, and histone covalent modifications along the gene locus. RESULTS NRS had significantly greater levels of IGF1 P1 (predominant transcript), and 1A and 1B mRNA variants compared to IMV at 3 or 21 days. NRS also led to more DNA methylation and greater occupancy of activating mark H3K4 trimethylation (H3K4me3), repressive mark H3K27me3, and elongation mark H3K36me3 compared to IMV. CONCLUSIONS NRS leads to distinct IGF1 mRNA variant levels and epigenetic profile in the hippocampus compared to IMV. IMPACT Our study shows that 3 or 21 days of NRS of preterm lambs leads to distinct IGF1 mRNA variant levels and epigenetic profile in the hippocampus compared to IMV. Preterm infant studies suggest that NRS leads to better neurodevelopmental outcomes later in life versus IMV. Also, duration of IMV is directly related to hippocampal damage; however, molecular players remain unknown. NRS, as a gentler mode of respiratory management of preterm neonates, may reduce damage to the immature hippocampus through an epigenetic mechanism.
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Affiliation(s)
- Xingrao Ke
- grid.223827.e0000 0001 2193 0096Department of Pediatrics, Division of Neonatology, School of Medicine, University of Utah, Salt Lake City, UT 84132-2202 USA
| | - Bohan Xing
- grid.223827.e0000 0001 2193 0096Department of Pediatrics, Division of Neonatology, School of Medicine, University of Utah, Salt Lake City, UT 84132-2202 USA
| | - Mar Janna Dahl
- grid.223827.e0000 0001 2193 0096Department of Pediatrics, Division of Neonatology, School of Medicine, University of Utah, Salt Lake City, UT 84132-2202 USA
| | - Jeremy Alvord
- grid.223827.e0000 0001 2193 0096Department of Pediatrics, Division of Neonatology, School of Medicine, University of Utah, Salt Lake City, UT 84132-2202 USA
| | - Robert A. McKnight
- grid.223827.e0000 0001 2193 0096Department of Pediatrics, Division of Neonatology, School of Medicine, University of Utah, Salt Lake City, UT 84132-2202 USA
| | - Robert H. Lane
- grid.239559.10000 0004 0415 5050Children Mercy Research Institute, Children’s Mercy, Kansas City, MO 64108 USA
| | - Kurt H. Albertine
- grid.223827.e0000 0001 2193 0096Department of Pediatrics, Division of Neonatology, School of Medicine, University of Utah, Salt Lake City, UT 84132-2202 USA
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10
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Gie AG, Hubble TR, Regin Y, Salaets T, Zamora M, Deprest J, Toelen J. A Systematic Review of the Influence of Continuous Positive Airway Pressure on Fetal and Newborn Animal Models: Suggestions to Improve Neonatal Respiratory Care. Neonatology 2021; 118:5-14. [PMID: 33091899 DOI: 10.1159/000511086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 08/23/2020] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Prematurely born infants regularly develop respiratory distress syndrome and require assisted ventilation. Ventilation may injure the premature lung and increase the risk of bronchopulmonary dysplasia. Continuous positive airway pressure (CPAP), a form of noninvasive ventilation, is commonly used in modern neonatology. Limited clinical data are available on the acute and long-term effect of neonatal exposure to CPAP on the lung. Given the restricted clinical data, newborn animal models have been used to study the influence of CPAP on lung structure and function. The findings of animal studies can guide neonatal care and improve the use of CPAP. METHODS A systematic review of electronic databases (Medline, Embase, and Cinahl) was performed using the medical subject heading terms, "CPAP" or "continuous positive airway pressure" and "animals" and "newborn." Abstracts were screened for inclusion using predetermined eligibility criteria. RESULTS In total, 235 abstracts were identified and screened for inclusion. Of these, 21 papers were included. Large (N = 18) and small (N = 3) animal models investigated the effects of CPAP. Pulmonary outcomes included gas exchange, lung structure and function, surfactant metabolism, lung inflammation and injury, and the effect of intrapulmonary therapy. Compared to mechanical ventilation, CPAP improves lung function, evokes less lung injury, and does not disrupt alveolar development. Surfactant administration combined with CPAP further improves respiratory outcomes. Of concern are findings that CPAP may increase airway reactivity. DISCUSSION/CONCLUSION CPAP offers numerous advantages over mechanical ventilation for the immature lung. The combination of CPAP and exogenous surfactant administration offers further pulmonary benefit.
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Affiliation(s)
- Andre George Gie
- Department of Development and Regeneration, KU Leuven, Leuven, Belgium
| | - Talia Rose Hubble
- Medical Science Division, University of Oxford, Oxford, United Kingdom
| | - Yannick Regin
- Department of Development and Regeneration, KU Leuven, Leuven, Belgium
| | - Thomas Salaets
- Department of Development and Regeneration, KU Leuven, Leuven, Belgium
| | - Monica Zamora
- BCNatal, Fetal Medicine Research Center, Hospital Clinic and Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain
| | - Jan Deprest
- Department of Development and Regeneration, KU Leuven, Leuven, Belgium.,Institute for Woman's Health, University College London Hospital, London, United Kingdom
| | - Jaan Toelen
- Department of Development and Regeneration, KU Leuven, Leuven, Belgium,
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11
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Sammour I, Karnati S. Non-invasive Respiratory Support of the Premature Neonate: From Physics to Bench to Practice. Front Pediatr 2020; 8:214. [PMID: 32457860 PMCID: PMC7227410 DOI: 10.3389/fped.2020.00214] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 04/09/2020] [Indexed: 12/04/2022] Open
Abstract
Premature births continue to rise globally with a corresponding increase in various morbidities among this population. Rates of respiratory distress syndrome and the consequent development of Bronchopulmonary Dysplasia (BPD) are highest among the extremely preterm infants. The majority of extremely low birth weight premature neonates need some form of respiratory support during their early days of life. Invasive modes of respiratory assistance have been popular amongst care providers for many years. However, the practice of prolonged invasive mechanical ventilation is associated with an increased likelihood of developing BPD along with other comorbidities. Due to the improved understanding of the pathophysiology of BPD, and technological advances, non-invasive respiratory support is gaining popularity; whether as an initial mode of support, or for post-extubation of extremely preterm infants with respiratory insufficiency. Due to availability of a wide range of modalities, wide variations in practice exist among care providers. This review article aims to address the physical and biological basis for providing non-invasive respiratory support, the current clinical evidence, and the most recent developments in this field of Neonatology.
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Affiliation(s)
- Ibrahim Sammour
- Department of Neonatology, Lerner College of Medicine, Pediatric Institute, Cleveland Clinic, Cleveland Clinic Foundation, Cleveland, OH, United States
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12
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Abstract
Over 50 years after its first description, Bronchopulmonary Dysplasia (BPD) remains a devastating pulmonary complication in preterm infants with respiratory failure and develops in 30-50% of infants less than 1000-gram birth weight. It is thought to involve ventilator- and oxygen-induced damage to an immature lung that results in an inflammatory response and ends in aberrant lung development with dysregulated angiogenesis and alveolarization. Significant morbidity and mortality are associated with this most common chronic lung disease of childhood. Thus, any therapies that decrease the incidence or severity of this condition would have significant impact on morbidity, mortality, human costs, and healthcare expenditure. It is clear that an inflammatory response and the elaboration of growth factors and cytokines are associated with the development of BPD. Numerous approaches to control the inflammatory process leading to the development of BPD have been attempted. This review will examine the anti-inflammatory approaches that are established or hold promise for the prevention or treatment of BPD.
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13
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Dahl MJ, Bowen S, Aoki T, Rebentisch A, Dawson E, Pettet L, Emerson H, Yu B, Wang Z, Yang H, Zhang C, Presson AP, Joss-Moore L, Null DM, Yoder BA, Albertine KH. Former-preterm lambs have persistent alveolar simplification at 2 and 5 months corrected postnatal age. Am J Physiol Lung Cell Mol Physiol 2018; 315:L816-L833. [PMID: 30211655 PMCID: PMC6295507 DOI: 10.1152/ajplung.00249.2018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 08/29/2018] [Accepted: 09/02/2018] [Indexed: 12/29/2022] Open
Abstract
Preterm birth and mechanical ventilation (MV) frequently lead to bronchopulmonary dysplasia, the histopathological hallmark of which is alveolar simplification. How developmental immaturity and ongoing injury, repair, and remodeling impact completion of alveolar formation later in life is not known, in part because of lack of suitable animal models. We report a new model, using former-preterm lambs, to test the hypothesis that they will have persistent alveolar simplification later in life. Moderately preterm lambs (~85% gestation) were supported by MV for ~6 days before being transitioned from all respiratory support to become former-preterm lambs. Results are compared with term control lambs that were not ventilated, and between males (M) and females (F). Alveolar simplification was quantified morphometrically and stereologically at 2 mo (4 M, 4 F) or 5 mo (4 M, 6 F) corrected postnatal age (cPNA) compared with unventilated, age-matched term control lambs (4 M, 4 F per control group). These postnatal ages in sheep are equivalent to human postnatal ages of 1-2 yr and ~6 yr, respectively. Multivariable linear regression results showed that former-preterm lambs at 2 or 5 mo cPNA had significantly thicker distal airspace walls ( P < 0.001 and P < 0.009, respectively), lower volume density of secondary septa ( P < 0.007 and P < 0.001, respectively), and lower radial alveolar count ( P < 0.003 and P < 0.020, respectively) compared with term control lambs. Sex-specific differences were not detected. We conclude that moderate preterm birth and MV for ~6 days impedes completion of alveolarization in former-preterm lambs. This new model provides the opportunity to identify underlying pathogenic mechanisms that may reveal treatment approaches.
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Affiliation(s)
- Mar Janna Dahl
- Division of Neonatology, Department of Pediatrics, University of Utah , Salt Lake City, Utah
| | - Sydney Bowen
- Division of Neonatology, Department of Pediatrics, University of Utah , Salt Lake City, Utah
| | - Toshio Aoki
- Division of Neonatology, Department of Pediatrics, University of Utah , Salt Lake City, Utah
| | - Andrew Rebentisch
- Division of Neonatology, Department of Pediatrics, University of Utah , Salt Lake City, Utah
| | - Elaine Dawson
- Division of Neonatology, Department of Pediatrics, University of Utah , Salt Lake City, Utah
| | - Luke Pettet
- Division of Neonatology, Department of Pediatrics, University of Utah , Salt Lake City, Utah
| | - Haleigh Emerson
- Division of Neonatology, Department of Pediatrics, University of Utah , Salt Lake City, Utah
| | - Baifeng Yu
- Division of Neonatology, Department of Pediatrics, University of Utah , Salt Lake City, Utah
| | - Zhengming Wang
- Division of Neonatology, Department of Pediatrics, University of Utah , Salt Lake City, Utah
| | - Haixia Yang
- Division of Neonatology, Department of Pediatrics, University of Utah , Salt Lake City, Utah
| | - Chong Zhang
- Division of Epidemiology, Department of Internal Medicine, University of Utah , Salt Lake City, Utah
| | - Angela P Presson
- Division of Epidemiology, Department of Internal Medicine, University of Utah , Salt Lake City, Utah
- Division of Critical Care, Department of Pediatrics, University of Utah , Salt Lake City, Utah
| | - Lisa Joss-Moore
- Division of Neonatology, Department of Pediatrics, University of Utah , Salt Lake City, Utah
| | - Donald M Null
- Division of Neonatology, University of California , Davis, California
| | - Bradley A Yoder
- Division of Neonatology, Department of Pediatrics, University of Utah , Salt Lake City, Utah
| | - Kurt H Albertine
- Division of Neonatology, Department of Pediatrics, University of Utah , Salt Lake City, Utah
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14
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Song Y, Dahl M, Leavitt W, Alvord J, Bradford CY, Albertine KH, Pillow JJ. Vitamin A Protects the Preterm Lamb Diaphragm Against Adverse Effects of Mechanical Ventilation. Front Physiol 2018; 9:1119. [PMID: 30150942 PMCID: PMC6099107 DOI: 10.3389/fphys.2018.01119] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 07/25/2018] [Indexed: 11/13/2022] Open
Abstract
Background: Preterm infants are deficient in vitamin A, which is essential for growth and development of the diaphragm. Preterm infants often require mechanical ventilation (MV) for respiratory distress. In adults, MV is associated with the development of ventilation-induced diaphragm dysfunction and difficulty weaning from the ventilator. We assessed the impact of MV on the preterm diaphragm and the protective effect of vitamin A during MV. Methods: Preterm lambs delivered operatively at ∼131 days gestation (full gestation: 150 days) received respiratory support by synchronized intermittent mandatory ventilation for 3 days. Lambs in the treated group received daily (24 h) enteral doses of 2500 IU/kg/day vitamin A combined with 250 IU/kg/day retinoic acid (VARA) during MV, while MV control lambs received saline. Unventilated fetal reference lambs were euthanized at birth, without being allowed to breathe. The fetal diaphragm was collected to quantify mRNA levels of myosin heavy chain (MHC) isoforms, atrophy genes, antioxidant genes, and pro-inflammatory genes; to determine ubiquitin proteasome pathway activity; to measure the abundance of protein carbonyl, and to investigate metabolic signaling. Results: Postnatal MV significantly decreased expression level of the neonatal MHC gene but increased expression level of MHC IIx mRNA level (p < 0.05). Proteasome activity increased after 3 days MV, accompanied by increased MuRF1 mRNA level and accumulated protein carbonyl abundance. VARA supplementation decreased proteasome activity and FOXO1 signaling, down-regulated MuRF1 expression, and reduced reactive oxidant production. Conclusion: These findings suggest that 3 days of MV results in abnormal myofibrillar composition, activation of the proteolytic pathway, and oxidative injury of diaphragms in mechanically ventilated preterm lambs. Daily enteral VARA protects the preterm diaphragm from these adverse effects.
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Affiliation(s)
- Yong Song
- School of Human Sciences, The University of Western Australia, Crawley, WA, Australia.,Centre for Neonatal Research and Education, Division of Paediatrics and Child Health, Medical School, The University of Western Australia, Crawley, WA, Australia.,School of Public Health, Curtin University, Bentley, WA, Australia.,Centre for Genetic Origins of Health and Disease, The University of Western Australia, Curtin University, Crawley, WA, Australia
| | - MarJanna Dahl
- Department of Pediatrics, University of Utah, Salt Lake City, UT, United States
| | - Wendy Leavitt
- Department of Pediatrics, University of Utah, Salt Lake City, UT, United States
| | - Jeremy Alvord
- Department of Pediatrics, University of Utah, Salt Lake City, UT, United States
| | - Calan Y Bradford
- Department of Pediatrics, University of Utah, Salt Lake City, UT, United States
| | - Kurt H Albertine
- Department of Pediatrics, University of Utah, Salt Lake City, UT, United States
| | - J Jane Pillow
- School of Human Sciences, The University of Western Australia, Crawley, WA, Australia.,Centre for Neonatal Research and Education, Division of Paediatrics and Child Health, Medical School, The University of Western Australia, Crawley, WA, Australia
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15
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Effects of preterm birth and ventilation on glomerular capillary growth in the neonatal lamb kidney. J Hypertens 2017; 34:1988-97. [PMID: 27428042 DOI: 10.1097/hjh.0000000000001028] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
OBJECTIVES Preterm birth is linked to the development of hypertension later in life. This may relate to impaired glomerular capillary growth following preterm birth. The aim of this study was to determine the effects of preterm birth, and/or ventilation, on glomerular capillary growth in the neonatal lamb kidney. METHODS Four experimental groups were analysed: preterm lambs delivered at 130 days gestation (term = 147 days) and mechanically ventilated for 3 days (preterm ventilated: n = 9), 133 days gestational controls (gestational control: n = 5), term controls, unassisted breathing for 3 days (term control: n = 8), and term lambs ventilated for 3 days (term ventilated: n = 5). In perfusion-fixed kidneys, total nephron number, average total capillary length, and surface area per renal corpuscle were stereologically assessed, and total renal filtration surface area (TRFSA) was calculated. RESULTS In comparison with term controls, preterm lambs had significantly reduced glomerular capillary length, surface area, and TRFSA, indicative of a low renal functional capacity. Term-ventilated lambs exhibited significantly reduced glomerular capillary length and surface area compared with term controls, indicating that ventilation impairs glomerular capillary growth independently of preterm birth. CONCLUSION Impaired glomerular capillary growth and subsequent reduced TRFSA following preterm birth may mediate the increased predisposition to hypertension later in life.
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16
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Staub E, Dahl MJ, Yost C, Bowen S, Aoki T, Blair A, Wang Z, Null DM, Yoder BA, Albertine KH. Preterm birth and ventilation decrease surface density of glomerular capillaries in lambs, regardless of postnatal respiratory support mode. Pediatr Res 2017; 82:93-100. [PMID: 28060793 PMCID: PMC5687580 DOI: 10.1038/pr.2017.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 11/04/2016] [Indexed: 01/01/2023]
Abstract
BACKGROUND Prematurity is often complicated by respiratory support, including invasive mechanical ventilation (IMV) and noninvasive support (NIS). Compared with IMV, NIS reduces injury to the lung and brain. Prematurity may also disrupt glomerular architecture. Whether NIS differentially affects glomerular architecture is incompletely understood. We hypothesized that IMV would lead to greater disruption of glomerular architecture than NIS. METHODS This is a secondary analysis of kidneys from moderately preterm lambs delivered at ~131 d gestation (term ~150 d) that had antenatal steroid exposure and surfactant treatment before resuscitation by IMV. At ~3 h of age, half of the lambs were switched to NIS. Support was for 3 d or 21 d. Structural indices of glomerular architecture were quantified. RESULTS The number of glomerular generations was unaffected by moderate preterm birth and respiratory support, either IMV or NIS. At 3 d and 21 d of IMV or NIS, glomerular capillary surface density was not different. Glomerular capillary surface density was significantly lower in the inner and outer cortex compared with unventilated gestation age-matched or postnatal age-matched reference lambs. CONCLUSION Moderate preterm birth and invasive or noninvasive respiratory support decreases glomerular capillarization in the lamb kidney. This adverse effect on glomerular development may contribute to increased risk for adult-onset hypertension and renal dysfunction.
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Affiliation(s)
- Eveline Staub
- Division of Neonatology, University Children's Hospital Basel UKBB, Basel, Switzerland,Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Mar Janna Dahl
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Calan Yost
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Sydney Bowen
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Toshio Aoki
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Adam Blair
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Zhengming Wang
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Donald M Null
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA,Division of Neonatology, University of California, Davis, CA, USA
| | - Bradley A Yoder
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Kurt H Albertine
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
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17
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Kollisch-Singule M, Jain SV, Satalin J, Andrews P, Searles Q, Liu Z, Zhou Y, Wang G, Meier AH, Gatto LA, Nieman GF, Habashi NM. Limiting ventilator-associated lung injury in a preterm porcine neonatal model. J Pediatr Surg 2017; 52:50-55. [PMID: 27837992 DOI: 10.1016/j.jpedsurg.2016.10.020] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 10/20/2016] [Indexed: 01/28/2023]
Abstract
PURPOSE Preterm infants are prone to respiratory distress syndrome (RDS), with severe cases requiring mechanical ventilation for support. However, there are no clear guidelines regarding the optimal ventilation strategy. We hypothesized that airway pressure release ventilation (APRV) would mitigate lung injury in a preterm porcine neonatal model. METHODS Preterm piglets were delivered on gestational day 98 (85% of 115day term), instrumented, and randomized to volume guarantee (VG; n=10) with low tidal volumes (5.5cm3kg-1) and PEEP 4cmH2O or APRV (n=10) with initial ventilator settings: PHigh 18cmH2O, PLow 0cmH2O, THigh 1.30s, TLow 0.15s. Ventilator setting changes were made in response to clinical parameters in both groups. Animals were monitored continuously for 24hours. RESULTS The mortality rates between the two groups were not significantly different (p>0.05). The VG group had relatively increased oxygen requirements (FiO2 50%±9%) compared with the APRV group (FiO2 28%±5%; p>0.05) and a decrease in PaO2/FiO2 ratio (VG 162±33mmHg; APRV 251±45mmHg; p<0.05). The compliance of the VG group (0.51±0.07L·cmH2O-1) was significantly less than the APRV group (0.90±0.06L·cmH2O-1; p<0.05). CONCLUSION This study demonstrates that APRV improves oxygenation and compliance as compared with VG. This preliminary work suggests further study into the clinical uses of APRV in the neonate is warranted. LEVEL OF EVIDENCE Not Applicable (Basic Science Animal Study).
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Affiliation(s)
| | - Sumeet V Jain
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY, 13210, USA.
| | - Joshua Satalin
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY, 13210, USA.
| | - Penny Andrews
- Department of Trauma Critical Care Medicine, R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, 22 S. Greene St., Baltimore, MD, 21201, USA.
| | - Quinn Searles
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY, 13210, USA.
| | - Zhiyong Liu
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY, 13210, USA.
| | - Yan Zhou
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY, 13210, USA.
| | - Guirong Wang
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY, 13210, USA.
| | - Andreas H Meier
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY, 13210, USA.
| | - Louis A Gatto
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY, 13210, USA; Department of Biological Sciences, SUNY Cortland, 22 Graham Ave, Cortland, NY, 13045, USA.
| | - Gary F Nieman
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY, 13210, USA.
| | - Nader M Habashi
- Department of Trauma Critical Care Medicine, R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, 22 S. Greene St., Baltimore, MD, 21201, USA.
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18
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Roberts JK, Stockmann C, Dahl MJ, Albertine KH, Egan E, Lin Z, Reilly CA, Ballard PL, Ballard RA, Ward RM. Pharmacokinetics of Budesonide Administered with Surfactant in Premature Lambs: Implications for Neonatal Clinical Trials. ACTA ACUST UNITED AC 2016; 11:53-61. [PMID: 26416605 DOI: 10.2174/1574884710666150929100210] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 09/17/2015] [Accepted: 09/28/2015] [Indexed: 11/22/2022]
Abstract
Bronchopulmonary dysplasia (BPD) is a chronic lung disease of premature human infants, which may persist through adulthood. Airway inflammation has been firmly established in the pathogenesis of BPD. Previous studies to reduce airway inflammation with high-dose dexamethasone demonstrated adverse neurological outcomes, despite lower incidences of BPD. Instillation of budesonide and surfactant can facilitate early extubation and reduce the incidence of BPD and death among very low birth weight infants. However, the pharmacokinetics of budesonide and its distribution into the lung and brain are unknown. Therefore, 5 premature lambs were administered 0.25 mg/kg budesonide, with surfactant as the vehicle. Plasma and tissue samples were taken from the lambs for measurement of budesonide, 16α- hydroxy prednisolone, and budesonide palmitate using LC/MS/MS. Peak plasma budesonide concentrations were inversely correlated with the oxygenation index (correlation coefficient of -0.75). plasma budesonide concentrations were extremely low (~10% of expected) for two lambs that had high oxygenation indices and were excluded from further analyses. For the remaining 5 premature lambs, a non-compartmental analysis demonstrated an AUCinf of 148.77 ± 28.16 h*μg/L, half-life of 4.76 ± 1.79 h, and Cmax of 46.17 ± 17.71 µg/L. Using population pharmacokinetic methods, a onecompartment model with exponential residual error and first-order absorption adequately described the data. The apparent clearance and apparent volume of distribution of budesonide were estimated at 6.29 L/h (1.99 L/h/kg) and 29.1 L (9.2 L/kg), respectively. Budesonide and budesonide palmitate, but not 16α-hydroxy prednisolone, were detected in lung tissue. In this study, budesonide and its metabolites were not detected in the brain, which suggests that intratracheal instillation suggests that after local pulmonary deposition, there is no evidence of budesonide accumulation in the central nervous system. Overall, these results show that peak plasma budesonide concentrations are inversely correlated with the oxygenation index and that lung-specific delivery of budesonide avoids accumulation of budesonide in the brain.
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19
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Alveolar formation is dysregulated by restricted nutrition but not excess sedation in preterm lambs managed by noninvasive support. Pediatr Res 2016; 80:719-728. [PMID: 27429203 PMCID: PMC5683895 DOI: 10.1038/pr.2016.143] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 05/02/2016] [Indexed: 12/12/2022]
Abstract
BACKGROUND Preterm birth and respiratory support with invasive mechanical ventilation frequently leads to bronchopulmonary dysplasia (BPD). A hallmark feature of BPD is alveolar simplification. For our preterm lamb model of BPD, invasive mechanical ventilation is associated with postnatal feeding intolerance (reduced nutrition) and sedation. In contrast, preterm lambs managed by noninvasive support (NIS) have normal alveolar formation, appropriate postnatal nutrition, and require little sedation. We used the latter, positive-outcome group to discriminate the contribution of reduced nutrition vs. sedation on alveolar simplification. We hypothesized that, restricted nutrition, but not sedation with pentobarbital, contributes to impaired indices of alveolar formation in preterm lambs managed by NIS. METHODS Preterm lambs managed by NIS for 21d were randomized into three groups: NIS control, NIS plus restricted nutrition, and NIS plus excess sedation with pentobarbital. We quantified morphological and biochemical indices of alveolar formation, as well as mesenchymal cell apoptosis and proliferation. RESULTS Restricted nutrition impaired morphological and biochemical indices of alveolar formation, and reduced mesenchymal cell apoptosis and proliferation. Excess sedation with pentobarbital did not alter these indices, although mesenchymal cell apoptosis was less. CONCLUSION Our results demonstrate that restricted nutrition, but not excess sedation, contributes to impaired alveolar formation during the evolution of BPD in chronically ventilated preterm lambs.
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20
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Deptula N, Royse E, Kemp MW, Miura Y, Kallapur SG, Jobe AH, Hillman NH. Brief mechanical ventilation causes differential epithelial repair along the airways of fetal, preterm lambs. Am J Physiol Lung Cell Mol Physiol 2016; 311:L412-20. [PMID: 27343193 PMCID: PMC5142451 DOI: 10.1152/ajplung.00181.2016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 06/20/2016] [Indexed: 02/01/2023] Open
Abstract
Mechanical ventilation of preterm lambs causes lung inflammation and injury to the airway epithelium, which is repaired by 15 days after ventilation. In mice, activated basal cells (p63+, KRT14+, KRT8+) initiate injury repair to the trachea, whereas club cells coordinate distal airway repair. In both human and sheep, basal cells line the pseudostratified airways to the distal bronchioles with club cells only present in terminal bronchioles. Mechanical ventilation causes airway epithelial injury that is repaired through basal cell activation in the fetal lung. Ewes at 123 ± 1 day gestational age had the head and chest of the fetus exteriorized and tracheostomy placed. With placental circulation intact, fetal lambs were mechanically ventilated with up to 15 ml/kg for 15 min with 95% N2/5% CO2 Fetal lambs were returned to the uterus for up to 24 h. The trachea, left mainstem bronchi, and peripheral lung were evaluated for epithelial injury and cellular response consistent with repair. Peripheral lung tissue had inflammation, pro-inflammatory cytokine production, epithelial growth factor receptor ligand upregulation, increased p63 expression, and proliferation of pro-SPB, TTF-1 positive club cells. In bronchi, KRT14 and KRT8 mRNA increased without increases in Notch pathway mRNA or proliferation. In trachea, mRNA increased for Notch ligands, SAM pointed domain-containing Ets transcription factor and mucin 5B, but not for basal cell markers. A brief period of mechanical ventilation causes differential epithelial activation between trachea, bronchi, and peripheral lung. The repair mechanisms identified in adult mice occur at different levels of airway branching in fetal sheep with basal and club cell activation.
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Affiliation(s)
- Nicole Deptula
- Division of Neonatology, Cardinal Glennon Children's Hospital, Saint Louis University, Saint Louis, Missouri
| | - Emily Royse
- Division of Neonatology, Cardinal Glennon Children's Hospital, Saint Louis University, Saint Louis, Missouri
| | - Matthew W Kemp
- School of Women's and Infants' Health, University of Western Australia, Perth, Australia
| | - Yuichiro Miura
- School of Women's and Infants' Health, University of Western Australia, Perth, Australia
| | - Suhas G Kallapur
- Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio; and School of Women's and Infants' Health, University of Western Australia, Perth, Australia
| | - Alan H Jobe
- Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio; and School of Women's and Infants' Health, University of Western Australia, Perth, Australia
| | - Noah H Hillman
- Division of Neonatology, Cardinal Glennon Children's Hospital, Saint Louis University, Saint Louis, Missouri;
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21
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Abstract
Non-invasive respiratory support is increasingly used in lieu of intubated ventilator support for the management of neonatal respiratory failure, particularly in very low birth weight infants at risk for bronchopulmonary dysplasia. The optimal approach and mode for non-invasive support remains uncertain. This article reviews the application of high-frequency ventilation for non-invasive respiratory support in neonates, including basic science studies on mechanics of gas exchange, animal model investigations, and a review of current clinical use in human neonates.
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Reyburn B, Di Fiore JM, Raffay T, Martin RJ, Prakash YS, Jafri A, MacFarlane PM. The Effect of Continuous Positive Airway Pressure in a Mouse Model of Hyperoxic Neonatal Lung Injury. Neonatology 2016; 109:6-13. [PMID: 26394387 PMCID: PMC4654984 DOI: 10.1159/000438818] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 07/16/2015] [Indexed: 11/19/2022]
Abstract
BACKGROUND Continuous positive airway pressure (CPAP) and supplemental oxygen have become the mainstay of neonatal respiratory support in preterm infants. Although oxygen therapy is associated with respiratory morbidities including bronchopulmonary dysplasia (BPD), the long-term effects of CPAP on lung function are largely unknown. We used a hyperoxia-induced mouse model of BPD to explore the effects of daily CPAP in the first week of life on later respiratory system mechanics. OBJECTIVE We wanted to test the hypothesis that daily CPAP in a newborn-mouse model of BPD improves longer-term respiratory mechanics. METHODS Mouse pups from C57BL/6 pregnant dams were exposed to room air (RA) or hyperoxia (50% O2, 24 h/day) for the first postnatal week with or without exposure to daily CPAP (6 cm H2O, 3 h/day). Respiratory system resistance (Rrs) and compliance (Crs) were measured following a subsequent 2-week period of RA recovery. Additional measurements included radial alveolar and macrophage counts. RESULTS Mice exposed to hyperoxia had significantly elevated Rrs, decreased Crs, reduced alveolarization and increased macrophage counts at 3 weeks when compared to RA-treated mice. Daily CPAP treatment significantly improved Rrs, Crs and alveolarization and decreased lung macrophage infiltration in the hyperoxia-exposed pups. CONCLUSIONS We have demonstrated that daily CPAP had a longer-term benefit on baseline respiratory system mechanics in a neonatal mouse model of BPD. We speculate that this beneficial effect of CPAP was the consequence of a decrease in the inflammatory response and resultant alveolar injury associated with hyperoxic lung injury in newborns.
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Affiliation(s)
- Brent Reyburn
- Division of Neonatology, Department of Pediatrics, Rainbow Babies and Children's Hospital, Case Western Reserve University, Cleveland, Ohio, USA
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Balany J, Bhandari V. Understanding the Impact of Infection, Inflammation, and Their Persistence in the Pathogenesis of Bronchopulmonary Dysplasia. Front Med (Lausanne) 2015; 2:90. [PMID: 26734611 PMCID: PMC4685088 DOI: 10.3389/fmed.2015.00090] [Citation(s) in RCA: 111] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 12/03/2015] [Indexed: 12/11/2022] Open
Abstract
The concerted interaction of genetic and environmental factors acts on the preterm human immature lung with inflammation being the common denominator leading to the multifactorial origin of the most common chronic lung disease in infants – bronchopulmonary dysplasia (BPD). Adverse perinatal exposure to infection/inflammation with added insults like invasive mecha nical ventilation, exposure to hyperoxia, and sepsis causes persistent immune dysregulation. In this review article, we have attempted to analyze and consolidate current knowledge about the role played by persistent prenatal and postnatal inflammation in the pathogenesis of BPD. While some parameters of the early inflammatory response (neutrophils, cytokines, etc.) may not be detectable after days to weeks of exposure to noxious stimuli, they have already initiated the signaling pathways of the inflammatory process/immune cascade and have affected permanent defects structurally and functionally in the BPD lungs. Hence, translational research aimed at prevention/amelioration of BPD needs to focus on dampening the inflammatory response at an early stage to prevent the cascade of events leading to lung injury with impaired healing resulting in the pathologic pulmonary phenotype of alveolar simplification and dysregulated vascularization characteristic of BPD.
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Affiliation(s)
- Jherna Balany
- Section of Neonatology, Department of Pediatrics, St. Christopher's Hospital for Children, Drexel University College of Medicine , Philadelphia, PA , USA
| | - Vineet Bhandari
- Section of Neonatology, Department of Pediatrics, St. Christopher's Hospital for Children, Drexel University College of Medicine , Philadelphia, PA , USA
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Jobe AH. Animal Models, Learning Lessons to Prevent and Treat Neonatal Chronic Lung Disease. Front Med (Lausanne) 2015; 2:49. [PMID: 26301222 PMCID: PMC4528292 DOI: 10.3389/fmed.2015.00049] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 07/14/2015] [Indexed: 11/23/2022] Open
Abstract
Bronchopulmonary dysplasia (BPD) is a unique injury syndrome caused by prolonged injury and repair imposed on an immature and developing lung. The decreased septation and decreased microvascular development phenotype of BPD can be reproduced in newborn rodents with increased chronic oxygen exposure and in premature primates and sheep with oxygen and/or mechanical ventilation. The inflammation caused by oxidants, inflammatory agonists, and/or stretch injury from mechanical ventilation seems to promote the anatomic abnormalities. Multiple interventions targeted to specific inflammatory cells or pathways or targeted to decreasing ventilation-mediated injury can substantially prevent the anatomic changes associated with BPD in term rodents and in preterm sheep or primate models. Most of the anti-inflammatory therapies with benefit in animal models have not been tested clinically. None of the interventions that have been tested clinically are as effective as anticipated from the animal models. These inconsistencies in responses likely are explained by the antenatal differences in lung exposures of the developing animals relative to very preterm humans. The animals generally have normal lungs while the lungs of preterm infants are exposed variably to intrauterine inflammation, growth abnormalities, antenatal corticosteroids, and poorly understood effects from the causes of preterm delivery. The animal models have been essential for the definition of the mediators that can cause a BPD phenotype. These models will be necessary to develop and test future-targeted interventions to prevent and treat BPD.
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Affiliation(s)
- Alan H Jobe
- Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati , Cincinnati, OH , USA
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Albertine KH. Utility of large-animal models of BPD: chronically ventilated preterm lambs. Am J Physiol Lung Cell Mol Physiol 2015; 308:L983-L1001. [PMID: 25770179 PMCID: PMC4437012 DOI: 10.1152/ajplung.00178.2014] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 02/19/2015] [Indexed: 11/22/2022] Open
Abstract
This paper is focused on unique insights provided by the preterm lamb physiological model of bronchopulmonary dysplasia (BPD). Connections are also made to insights provided by the former preterm baboon model of BPD, as well as to rodent models of lung injury to the immature, postnatal lung. The preterm lamb and baboon models recapitulate the clinical setting of preterm birth and respiratory failure that require prolonged ventilation support for days or weeks with oxygen-rich gas. An advantage of the preterm lamb model is the large size of preterm lambs, which facilitates physiological studies for days or weeks during the evolution of neonatal chronic lung disease (CLD). To this advantage is linked an integrated array of morphological, biochemical, and molecular analyses that are identifying the role of individual genes in the pathogenesis of neonatal CLD. Results indicate that the mode of ventilation, invasive mechanical ventilation vs. less invasive high-frequency nasal ventilation, is related to outcomes. Our approach also includes pharmacological interventions that test causality of specific molecular players, such as vitamin A supplementation in the pathogenesis of neonatal CLD. The new insights that are being gained from our preterm lamb model may have important translational implications about the pathogenesis and treatment of BPD in preterm human infants.
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Affiliation(s)
- Kurt H Albertine
- Department of Pediatrics, University of Utah, School of Medicine, Salt Lake City, Utah; Department of Medicine, University of Utah, School of Medicine, Salt Lake City, Utah; and Department of Neurobiology and Anatomy, University of Utah, School of Medicine, Salt Lake City, Utah
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Dargaville PA, Lavizzari A, Padoin P, Black D, Zonneveld E, Perkins E, Sourial M, Rajapaksa AE, Davis PG, Hooper SB, Moss TJ, Polglase GR, Tingay DG. An authentic animal model of the very preterm infant on nasal continuous positive airway pressure. Intensive Care Med Exp 2015. [PMID: 26215815 PMCID: PMC4512986 DOI: 10.1186/s40635-015-0051-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The surge in uptake of nasal continuous positive airway pressure (CPAP) for respiratory support in preterm infants has occurred in the absence of an authentic animal model. Such a model would allow investigation of research questions of physiological and therapeutic importance. We therefore aimed to develop a preterm lamb model of the non-intubated very preterm infant on CPAP. METHODS After staged exteriorisation and instrumentation, preterm lambs were delivered from anaesthetised ewes at 131 to 133 days gestation. Via a single nasal prong (4-mm internal diameter, 6- to 7-cm depth), positive pressure was delivered from the outset, with nasal intermittent positive pressure ventilation (NIPPV) used until transition to nasal CPAP was attempted, and periodically thereafter for hypoventilation. Caffeine and doxapram were used as respiratory stimulants. Gastric distension was prevented with an oesophageal balloon. Cardiorespiratory parameters and results of arterial blood gas analyses were monitored throughout the study period, which continued for 150 min after first transition to CPAP. RESULTS Ten preterm lambs were studied, at gestation 132 ± 1 days (mean ± SD) and birth weight 3.6 ± 0.45 kg. After stabilisation on NIPPV, transition to nasal CPAP was first attempted at 28 ± 11 min. There was transient respiratory acidosis, with gradual resolution as spontaneous respiratory activity increased. In the final hour, 79% ± 33% of time was spent on CPAP alone, with typical respiratory rates around 60 breaths per minute. PaCO2 at end-experiment was 58 ± 36 mmHg. CONCLUSIONS Non-intubated preterm lambs can be effectively transitioned to nasal CPAP soon after birth. This animal model will be valuable for further research.
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Affiliation(s)
- Peter A Dargaville
- Department of Paediatrics, Royal Hobart Hospital, 48 Liverpool St, Hobart, Tasmania, 7000, Australia,
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Jobe AH, Tibboel D. Update in pediatric lung disease 2013. Am J Respir Crit Care Med 2014; 189:1031-6. [PMID: 24787065 DOI: 10.1164/rccm.201402-0230up] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Alan H Jobe
- 1 Department of Pediatrics, Cincinnati Children's Hospital, University of Cincinnati, Cincinnati, Ohio; and
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28
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Null DM, Alvord J, Leavitt W, Wint A, Dahl MJ, Presson AP, Lane RH, DiGeronimo RJ, Yoder BA, Albertine KH. High-frequency nasal ventilation for 21 d maintains gas exchange with lower respiratory pressures and promotes alveolarization in preterm lambs. Pediatr Res 2014; 75:507-16. [PMID: 24378898 PMCID: PMC3961520 DOI: 10.1038/pr.2013.254] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Accepted: 09/26/2013] [Indexed: 01/08/2023]
Abstract
BACKGROUND Short-term high-frequency nasal ventilation (HFNV) of preterm neonates provides acceptable gas exchange compared to endotracheal intubation and intermittent mandatory ventilation (IMV). Whether long-term HFNV will provide acceptable gas exchange is unknown. We hypothesized that HFNV for up to 21 d would lead to acceptable gas exchange at lower inspired oxygen (O2) levels and airway pressures compared to intubation and IMV. METHODS Preterm lambs were exposed to antenatal steroids and treated with perinatal surfactant and postnatal caffeine. Lambs were intubated and resuscitated by IMV. At ~3 h of age, half of the lambs were switched to noninvasive HFNV. Support was for 3 or 21 d. By design, Pao2 and Paco2 were not different between groups. RESULTS At 3 d (n = 5) and 21 d (n = 4) of HFNV, fractional inspired O2 (FiO2), peak inspiratory pressure (PIP), mean airway, intratracheal, and positive end-expiratory pressures, oxygenation index, and alveolar-arterial gradient were significantly lower than matched periods of intubation and IMV. Pao2/FiO2 ratio was significantly higher at 3 and 21 d of HFNV compared to matched intubation and IMV. HFNV led to better alveolarization at 3 and 21 d. CONCLUSION Long-term HFNV provides acceptable gas exchange at lower inspired O2 levels and respiratory pressures compared to intubation and IMV.
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Affiliation(s)
- Donald M. Null
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Jeremy Alvord
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Wendy Leavitt
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Albert Wint
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Mar Janna Dahl
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Angela P. Presson
- Division of Epidemiology, University of Utah, Salt Lake City, UT, USA
| | - Robert H. Lane
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Robert J. DiGeronimo
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Bradley A. Yoder
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Kurt H. Albertine
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
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Abstract
PURPOSE OF THE REVIEW Noninvasive respiratory support for neonates is growing in popularity as clinicians increasingly recognize the dangers of prolonged invasive ventilation. The purpose of this review is to critically evaluate the existing evidence for safety and efficacy of these modes of respiratory support in neonates. RECENT FINDINGS In recent years, multiple randomized controlled trials (RCTs) have evaluated several modes of noninvasive support, most importantly nasal intermittent positive pressure ventilation and high flow nasal cannulae, in comparison to the standard therapy of continuous positive airway pressure (CPAP). The three largest RCTs were recently published in 2013. One demonstrated no difference in death or survival with bronchopulmonary dysplasia between nasal intermittent positive pressure ventilation and CPAP, both when used as primary support and as postextubation support. Two others demonstrated that high flow nasal cannulae are noninferior to or no better than CPAP when used to support preterm infants after extubation. These trials showed no serious safety concerns with current modalities. SUMMARY The optimal forms of noninvasive respiratory support for neonates remain to be determined. Continued evaluation of these technologies with large, well-designed RCTs is warranted.
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Esquibies AE, Karihaloo A, Quaggin SE, Bazzy-Asaad A, Cantley LG. Heparin binding VEGF isoforms attenuate hyperoxic embryonic lung growth retardation via a FLK1-neuropilin-1-PKC dependent pathway. Respir Res 2014; 15:32. [PMID: 24641672 PMCID: PMC4004166 DOI: 10.1186/1465-9921-15-32] [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: 08/27/2013] [Accepted: 03/14/2014] [Indexed: 12/14/2022] Open
Abstract
Background Previous work in our laboratory demonstrated that hyperoxia suppressed the expression of vascular endothelial growth factor (VEGF) by the embryonic lung, leading to increased epithelial cell apoptosis and failure of explant airway growth and branching that was rescued by the addition of Vegf165. The aims of this study were to determine protective pathways by which VEGF isoforms attenuate hyperoxic lung growth retardation and to identify the target cell for VEGF action. Methods Timed pregnant CD-1 or fetal liver kinase (FLK1)-eGFP lung explants cultured in 3% or 50% oxygen were treated ± Vegf121, VEGF164/Vegf165 or VEGF188 in the presence or absence of anti-rat neuropilin-1 (NRP1) antibody or GO6983 (protein kinase C (PKC) pan-inhibitor) and lung growth and branching quantified. Immunofluorescence studies were performed to determine apoptosis index and location of FLK1 phosphorylation and western blot studies of lung explants were performed to define the signaling pathways that mediate the protective effects of VEGF. Results Heparin-binding VEGF isoforms (VEGF164/Vegf165 and VEGF188) but not Vegf121 selectively reduced epithelial apoptosis and partially rescued lung bud branching and growth. These protective effects required NRP1-dependent FLK1 activation in endothelial cells. Analysis of downstream signaling pathways demonstrated that the VEGF-mediated anti-apoptotic effects were dependent on PKC activation. Conclusions Vegf165 activates FLK1-NRP1 signaling in endothelial cells, leading to a PKC-dependent paracrine signal that in turn inhibits epithelial cell apoptosis.
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Affiliation(s)
- Americo E Esquibies
- Department of Pediatrics Section of Respiratory Medicine, Yale University School of Medicine, 333 Cedar Street, P,O, Box 208064, New Haven, CT 06520, USA.
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31
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Bhandari V. Postnatal inflammation in the pathogenesis of bronchopulmonary dysplasia. ACTA ACUST UNITED AC 2014; 100:189-201. [PMID: 24578018 DOI: 10.1002/bdra.23220] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Revised: 01/02/2014] [Accepted: 01/05/2014] [Indexed: 12/18/2022]
Abstract
Exposure to hyperoxia, invasive mechanical ventilation, and systemic/local sepsis are important antecedents of postnatal inflammation in the pathogenesis of bronchopulmonary dysplasia (BPD). This review will summarize information obtained from animal (baboon, lamb/sheep, rat and mouse) models that pertain to the specific inflammatory agents and signaling molecules that predispose a premature infant to BPD.
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Affiliation(s)
- Vineet Bhandari
- Division of Perinatal Medicine, Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut
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33
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Intrauterine growth restriction transiently delays alveolar formation and disrupts retinoic acid receptor expression in the lung of female rat pups. Pediatr Res 2013; 73:612-620. [PMID: 23419538 PMCID: PMC4021738 DOI: 10.1038/pr.2013.38] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND We showed that intrauterine growth restriction (IUGR) increases distal airspace wall thickness at birth (postnatal age 0; P0) in rat pups (saccular stage of lung development). However, that report did not assess whether the saccular phenotype persisted postnatally or occurred in males or females, nor did the report identify a potential molecular pathway for the saccular phenotype at P0. We hypothesized that IUGR persistently delays alveolar formation and disrupts retinoic acid receptor (RAR) mRNA and protein levels in the lung of rat pups in a postnatal age- and sex-specific manner. METHODS IUGR was induced in pregnant rats by bilateral uterine artery ligation. Alveolar formation and expression of RARα, -β, and -γ were quantified at P0, P6 (alveolar stage), and P21 (postalveolarization). RESULTS IUGR increased distal airspace wall thickness in female pups at P0 only. IUGR did not affect male pups at any age. IUGR transiently increased lung RAR-β protein abundance, which inhibits alveolar formation, at P0 in female pups. Serum retinol concentration was normal at all ages. CONCLUSION IUGR alone is not sufficient to persistently delay postnatal alveolar formation or disrupt expression of RARs. We speculate that for IUGR to delay alveolar formation postnatally, a second insult is necessary.
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Abstract
Bronchopulmonary dysplasia (BPD) is among the most common chronic lung diseases in infants in the US. Improved survival of preterm infants who developed BPD is becoming increasingly important because of the high risk for persistent pulmonary morbidities such as poor respiratory gas exchange, pulmonary hypertension, and excess airway expiratory resistance later in life. This review focuses on unique insights provided by the two large-animal, physiological models of neonatal chronic lung disease: preterm baboons and preterm lambs. The models' are valuable because they contribute to better understanding of the underlying molecular pathogenic mechanisms. An epigenetic hypothesis is proposed as a pathogenic mechanism for BPD and its persistent pulmonary morbidities.
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Affiliation(s)
- Kurt H. Albertine
- Departments of Pediatrics, Medicine, Neurobiology & Anatomy, University of Utah, School of Medicine, Salt Lake City, Utah 84158-1289
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Shaffer TH, Alapati D, Greenspan JS, Wolfson MR. Neonatal non-invasive respiratory support: physiological implications. Pediatr Pulmonol 2012; 47:837-47. [PMID: 22777738 PMCID: PMC3762325 DOI: 10.1002/ppul.22610] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Accepted: 05/16/2012] [Indexed: 11/10/2022]
Abstract
The introduction of assisted ventilation for neonatal pulmonary insufficiency has resulted in the successful treatment of many previously fatal diseases. During the past three decades, refinement of invasive mechanical ventilation techniques has dramatically improved survival of many high-risk neonates. However, as with many advances in medicine, while mortality has been reduced, morbidity has increased in the surviving high-risk neonate. In this regard, introduction of assisted ventilation has been associated with chronic lung injury, also known as bronchopulmonary dysplasia. This disease, unknown prior to the appearance of mechanical ventilation, has produced a population of patients characterized by ventilator or oxygen dependence with serious accompanying pulmonary and neurodevelopmental morbidity. The purpose of this article is to review non-invasive respiratory support methodologies to address the physiologic mechanisms by which these methods may prevent the pathophysiologic effects of invasive mechanical ventilation.
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Affiliation(s)
- Thomas H Shaffer
- Nemours Center for Pediatric Lung Research, Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE 19803, USA.
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36
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Abstract
Multiple randomized controlled trials have suggested that nasal intermittent positive pressure ventilation, compared with nasal continuous airway pressure, prevents extubation failure and may decrease bronchopulmonary dysplasia. This article summarizes these studies and suggests strategies for the use of nasal intermittent positive pressure ventilation in neonates.
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Affiliation(s)
- Vineet Bhandari
- Division of Perinatal Medicine, Department of Pediatrics, Yale University School of Medicine, Yale Child Health Research Center, Room 219, PO Box 208081, 464 Congress Avenue, New Haven, CT 06520, USA.
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Albertine KH. Brain injury in chronically ventilated preterm neonates: collateral damage related to ventilation strategy. Clin Perinatol 2012; 39:727-40. [PMID: 22954278 PMCID: PMC3437037 DOI: 10.1016/j.clp.2012.06.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Brain injury is a frequent comorbidity in chronically ventilated preterm infants. However, the molecular basis of the brain injury remains incompletely understood. This article discusses the subtle (diffuse) form of brain injury that has white matter and gray matter lesions without germinal matrix hemorrhage-intraventricular hemorrhage, posthemorrhagic hydrocephalus, or cystic periventricular leukomalacia. This article synthesizes data that suggest that diffuse lesions to white matter and gray matter are collateral damage related to ventilator strategy. Evidence is introduced from the 2 large-animal, physiologic models of evolving neonatal chronic lung disease that suggest that an epigenetic mechanism may underlie the collateral damage.
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Affiliation(s)
- Kurt H. Albertine
- Departments of Pediatrics, Medicine, Neurobiology & Anatomy, University of Utah School of Medicine, Salt Lake City, Utah 84158
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Hogmalm A, Bäckström E, Bry M, Lappalainen U, Lukkarinen HP, Bry K. Role of CXC chemokine receptor-2 in a murine model of bronchopulmonary dysplasia. Am J Respir Cell Mol Biol 2012; 47:746-58. [PMID: 22865624 DOI: 10.1165/rcmb.2011-0394oc] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The contribution of neutrophils and CXC chemokines to the pathogenesis of bronchopulmonary dysplasia is not well defined. The transgenic expression of IL-1β in the pulmonary epithelium causes lung inflammation and disrupts alveolar development in infant mice. To study the hypothesis that CXC chemokine receptor-2 (CXCR2) is a mediator of inflammatory lung injury, we compared lung development in IL-1β-expressing mice with wild-type (IL-1β/CXCR2(+/+)) or null (IL-1β/CXCR2(-/-)) CXCR2 loci. CXCR2 deficiency abolished the transmigration of neutrophils into the alveolar lumen in IL-1β-expressing mice, but did not alter the number of neutrophils in the parenchyma. The deletion of CXCR2 increased the alveolar chord length and reduced the survival of mice when IL-1β was expressed from the pseudoglandular to the alveolar stages. The capillary configuration was highly abnormal in both IL-1β/CXCR2(+/+) and IL-1β/CXCR2(-/-) lungs, but in very different ways. The cellular area of the parenchyma and the total capillary area of IL-1β/CXCR2(+/+) and IL-1β/CXCR2(-/-) mice were smaller than those of control/CXCR2(+/+) and control/CXCR2(-/-) mice, but the ratio of capillary area to cellular area was similar in all four genotypes. When IL-1β was expressed during the saccular stage, IL-1β/CXCR2(-/-) mice had smaller alveolar chord lengths and better survival than did IL-1β/CXCR2(+/+) mice. Independent of the timing of IL-1β expression, IL-1β increased alveolar septal thickness in mice with wild-type CXCR2 loci, but not in CXCR2 null mice. Depending on the developmental stage at the time of the inflammatory insult, inhibition of the CXCR2 pathway may exert opposite effects on alveolar septation in the neonatal lung.
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Affiliation(s)
- Anna Hogmalm
- Department of Pediatrics, University of Gothenburg, Gothenburg, Sweden
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Zhu L, Li H, Tang J, Zhu J, Zhang Y. Hyperoxia arrests alveolar development through suppression of histone deacetylases in neonatal rats. Pediatr Pulmonol 2012; 47:264-74. [PMID: 21905265 DOI: 10.1002/ppul.21540] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2011] [Accepted: 05/23/2011] [Indexed: 01/04/2023]
Abstract
Bronchopulmonary dysplasia (BPD) poses a significant global health problem. It mainly occurs in preterm infants. It is histopathologically characterized by fewer and larger alveoli and less secondary septa, suggesting an arrested or disordered lung development. To date, the mechanisms that lead to the pathophysiological changes in BPD have still not been totally understood. In embryonic development, histone deacetylase (HDAC) plays an important role by regulating gene transcription. Here, we hypothesize that a decreased HDAC expression and activity, caused by preterm birth or environmental stresses, contribute to a disorder in alveolar development in BPD. To this end, newborn Sprague-Dawley rats subjected to hyperoxia (85% O(2) ) were used to investigate the gene expression and protein activity of HDAC and alveolar development in lungs. Our results showed that hyperoxia exposure led to a suppression of the HDAC1/HDAC2 expression and activity, and the overall HDAC activity, as well as arrest of alveolarization, and an elevated expression of the cytokine-induced neutrophil chemoattractant-1 (CINC-1) in the lungs of newborn rats. However, preservation of HDAC activity by theophylline significantly improved alveolar development and attenuated CINC-1 release, all of which were blocked by a specific HDAC inhibitor, trichostatin A (TSA). TSA alone can disturb the alveolar development in neonatal rats. Our findings indicate that a persistent exposure to hyperoxia leads to a suppressed HDAC activity, which causes disorders in pulmonary development. This effect may be mediated by CINC-1. Attenuation of CINC-1-mediated inflammation by activating HDAC may have a protective effect in BPD.
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Affiliation(s)
- Lüchang Zhu
- XinHua Hospital, Shanghai Institute for Pediatric Research, Shanghai Jiaotong University School of Medicine, Shanghai, China
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40
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Rehan VK, Fong J, Lee R, Sakurai R, Wang ZM, Dahl MJ, Lane RH, Albertine KH, Torday JS. Mechanism of reduced lung injury by high-frequency nasal ventilation in a preterm lamb model of neonatal chronic lung disease. Pediatr Res 2011; 70:462-6. [PMID: 21814155 PMCID: PMC3189277 DOI: 10.1203/pdr.0b013e31822f58a1] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The mechanism underlying the potentially beneficial effects of the "gentler" modes of ventilation on chronic lung disease (CLD) of the premature infant is not known. We have previously demonstrated that alveolar parathyroid hormone-related protein-peroxisome proliferator-activated receptorγ (PTHrP-PPARγ) signaling is critically important in alveolar formation, and this signaling pathway is disrupted in hyperoxia- and/or volutrauma-induced neonatal rat lung injury. Whether the same paradigm is also applicable to CLD, resulting from prolonged intermittent mandatory ventilation (IMV), and whether differential effects of the mode of ventilation on the PTHrP-PPARγ signaling pathway explain the potential benefits of the "gentler" modes of ventilation are not known. Using a well-established preterm lamb model of neonatal CLD, we tested the hypothesis that ventilatory support using high-frequency nasal ventilation (HFNV) promotes alveolar PTHrP-PPARγ signaling, whereas IMV inhibits it. Preterm lambs managed by HFNV or IMV for 21 d following preterm delivery at 132-d gestation were studied by Western hybridization and immunofluorescence labeling for key markers of alveolar homeostasis and injury/repair. In lambs managed by IMV, the abundance of key homeostatic alveolar epithelial-mesenchymal markers was reduced, whereas it was significantly increased in the HFNV group, providing a potential molecular mechanism by which "gentler" modes of ventilation reduce neonatal CLD.
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Affiliation(s)
- Virender K Rehan
- Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California 90502, 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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Diblasi RM, Zignego JC, Smith CV, Hansen TN, Richardson CP. Effective gas exchange in paralyzed juvenile rabbits using simple, inexpensive respiratory support devices. Pediatr Res 2010; 68:526-30. [PMID: 20814347 DOI: 10.1203/pdr.0b013e3181f985f0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We have developed two devices: a high-amplitude bubble continuous positive airway pressure (HAB-CPAP) and an inexpensive bubble intermittent mandatory ventilator (B-IMV) to test the hypotheses that simple, inexpensive devices can provide gas exchange similar to that of bubble CPAP (B-CPAP) and conventional mechanical ventilation (CMV). Twelve paralyzed juvenile rabbits were intubated, stabilized on CMV, and then switched to CPAP. On identical mean airway pressures (MAPs), animals were unable to maintain pulse oximeter oxygen saturation (SpO2) >80% on conventional B-CPAP, but all animals oxygenated well (97.3 ± 2.1%) on HAB-CPAP. In fact, arterial partial pressures of O2 (Pao2) were higher during HAB-CPAP than during CMV (p = 0.01). After repeated lung lavages, arterial partial pressures of CO2 (Paco2) were lower with B-IMV than with CMV (p < 0.0001), despite identical ventilator settings. In lavaged animals, when HAB-CPAP was compared with CMV at the same MAP and 100% O2, no differences were observed in Pao2, but Paco2 levels were higher with HAB-CPAP (70 ± 7 versus 50 ± 5 mm Hg; p < 0.05). Arterial blood pressures were not impaired by HAB-CPAP or B-IMV. The results confirm that simple inexpensive devices can provide respiratory support in the face of severe lung disease and could extend the use of respiratory support for preterm infants into severely resource-limited settings.
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Affiliation(s)
- Robert M Diblasi
- Center for Developmental Therapeutics, Seattle Children's Research Institute, Seattle, Washington 98101, USA.
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Albertine KH, Dahl MJ, Gonzales LW, Wang ZM, Metcalfe D, Hyde DM, Plopper CG, Starcher BC, Carlton DP, Bland RD. Chronic lung disease in preterm lambs: effect of daily vitamin A treatment on alveolarization. Am J Physiol Lung Cell Mol Physiol 2010; 299:L59-72. [PMID: 20382748 DOI: 10.1152/ajplung.00380.2009] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Neonatal chronic lung disease is characterized by failed formation of alveoli and capillaries, and excessive deposition of matrix elastin, which are linked to lengthy mechanical ventilation (MV) with O(2)-rich gas. Vitamin A supplementation has improved respiratory outcome of premature infants, but there is little information about the structural and molecular manifestations in the lung that occur with vitamin A treatment. We hypothesized that vitamin A supplementation during prolonged MV, without confounding by antenatal steroid treatment, would improve alveolar secondary septation, decrease thickness of the mesenchymal tissue cores between distal air space walls, and increase alveolar capillary growth. We further hypothesized that these structural advancements would be associated with modulated expression of tropoelastin and deposition of matrix elastin, phosphorylated Smad2 (pSmad2), cleaved caspase 3, proliferating cell nuclear antigen (PCNA), VEGF, VEGF-R2, and midkine in the parenchyma of the immature lung. Eight preterm lambs (125 days' gestation, term approximately 150 days) were managed by MV for 3 wk: four were treated with daily intramuscular Aquasol A (vitamin A), 5,000 IU/kg, starting at birth; four received vehicle alone. Postmortem lung assays included quantitative RT-PCR and in situ hybridization, immunoblot and immunohistochemistry, and morphometry and stereology. Daily vitamin A supplementation increased alveolar secondary septation, decreased thickness of the mesenchymal tissue cores between the distal air space walls, and increased alveolar capillary growth. Associated molecular changes were less tropoelastin mRNA expression, matrix elastin deposition, pSmad2, and PCNA protein localization in the mesenchymal tissue core of the distal air space walls. On the other hand, mRNA expression and protein abundance of VEGF, VEGF-R2, midkine, and cleaved caspase 3 were increased. We conclude that vitamin A treatment partially improves lung development in chronically ventilated preterm neonates by modulating expression of tropoelastin, deposition of elastin, and expression of vascular growth factors.
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Affiliation(s)
- Kurt H Albertine
- Department of Pediatrics, University of Utah Health Sciences Center, Salt Lake City, Utah 84158, USA.
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Abstract
Lung development is orchestrated by highly integrated morphogenic programs of interrelated patterns of gene and protein expression. Injury to the developing lung in the canalicular and saccular phases of lung development alters subsequent alveolar and vascular development resulting in simplified alveolar structures, dysmorphic capillary configuration, variable interstitial cellularity and fibroproliferation that are characteristic of the 'new' bronchopulmonary dysplasia (BPD). Fetal and neonatal infection, abnormal stretch of the developing airways and alveoli, altered expression of surfactant proteins (or genetically altered proteins), polymorphisms of genes encoding for vascular endothelial growth factors, and reactive oxygen species result in imparied gas exchange in the developing lung. However, the 'new' BPD represents only one form of neonatal chronic lung disease and the consistent use of both the physiologic definition and severity scale would provide greater accuracy in determining the impact of the disease currently defined by its treatment. Our present labelling of the clinical state of oxygen supplementation and/or ventilatory support at 36 weeks' postmenstrual age and the histopathologic severity of alveolar arrest and vascular 'simplification' may not always be predictive of the degree of altered lung development and thus longer-term pulmonary function evaluations are needed to determine the impact of this disorder in specific infants. The proposed role of novel molecular therapies, and the combined effects of currently established therapies, as well as exogenous surfactant and inhaled nitric oxide or repetitive surfactant dosing, on the severity and incidence of new BPD hold considerable promise for reducing the long-term pulmonary morbidity among infants delivered prematurely.
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Hogmalm A, Sheppard D, Lappalainen U, Bry K. beta6 Integrin subunit deficiency alleviates lung injury in a mouse model of bronchopulmonary dysplasia. Am J Respir Cell Mol Biol 2009; 43:88-98. [PMID: 19717813 DOI: 10.1165/rcmb.2008-0480oc] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Pulmonary inflammation is associated with the development of bronchopulmonary dysplasia in premature infants. We have previously shown that perinatal pulmonary expression of human IL-1beta is sufficient to cause a lung disease similar to bronchopulmonary dysplasia, characterized by inflammation, impaired alveolarization, poor postnatal growth, and increased mortality in infant mice. The alphavbeta6 integrin plays a critical role in regulating inflammation in the adult lung. To study the role of the beta6 integrin subunit in neonatal inflammatory lung disease, we compared the pulmonary development in IL-1beta-expressing infant mice with wild-type or null beta6 integrin loci. Absence of the beta6 integrin subunit decreased the mortality and improved the postnatal growth of IL-1beta-expressing pups. The disrupted alveolar development of IL-1beta-expressing mice was improved by beta6 integrin deficiency. IL-1beta-expressing beta6(-/-) pups had shorter alveolar chord length and thinner alveolar walls than IL-1beta-expressing beta6(+/+) pups. In addition, the absence of the beta6 integrin subunit reduced IL-1beta-induced neutrophil and macrophage infiltration into the alveolar spaces. beta6 integrin subunit deficiency suppressed inflammation and goblet cell hyperplasia in the airways and alleviated airway remodeling in IL-1beta-expressing mice. The expression of the chemoattractant proteins, keratinocyte-derived chemokine, macrophage-inflammatory protein-2, calgranulin A, and calgranulin B, of osteopontin, and of the chitinase-like lectins, Ym1 and Ym2, was lower in IL-1beta-expressing beta6(-/-) than in IL-1beta-expressing beta6(+/+) mice. We conclude that absence of the beta6 integrin subunit protects the infant murine lung against IL-1beta-induced inflammation and injury.
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Affiliation(s)
- Anna Hogmalm
- University of Gothenburg, Department of Pediatrics, the Queen Silvia Children's Hospital, SWE-416 85 Gothenburg, Sweden
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Abstract
Non-invasive ventilation (NIV) is increasingly being used in preterm infants with the purpose of reducing the risk of adverse pulmonary outcome associated with invasive mechanical ventilation. This review analyzes the evidence from physiologic and clinical studies on the use of NIV in the preterm infant. Physiologic data indicate advantages of NIV with regard to ventilation, gas exchange, breathing effort and thoraco-abdominal distortion. Data from clinical trials have consistently shown facilitation of weaning from mechanical ventilation and potential benefits in infants with RDS and apnoea. Long term improvements in respiratory outcome have also been reported but need to be confirmed in larger trials.
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Affiliation(s)
- Eduardo Bancalari
- Division of Neonatology, Department of Pediatrics, University of Miami Miller School of Medicine, Miami, Florida, USA.
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