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Paget TL, Larcombe AN, Pinniger GJ, Tsioutsias I, Schneider JP, Parkinson-Lawrence EJ, Orgeig S. Mucopolysaccharidosis (MPS IIIA) mice have increased lung compliance and airway resistance, decreased diaphragm strength, and no change in alveolar structure. Am J Physiol Lung Cell Mol Physiol 2024; 326:L713-L726. [PMID: 38469649 DOI: 10.1152/ajplung.00445.2022] [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: 01/02/2023] [Revised: 12/18/2023] [Accepted: 01/18/2024] [Indexed: 03/13/2024] Open
Abstract
Mucopolysaccharidosis type IIIA (MPS IIIA) is characterized by neurological and skeletal pathologies caused by reduced activity of the lysosomal hydrolase, sulfamidase, and the subsequent primary accumulation of undegraded heparan sulfate (HS). Respiratory pathology is considered secondary in MPS IIIA and the mechanisms are not well understood. Changes in the amount, metabolism, and function of pulmonary surfactant, the substance that regulates alveolar interfacial surface tension and modulates lung compliance and elastance, have been reported in MPS IIIA mice. Here we investigated changes in lung function in 20-wk-old control and MPS IIIA mice with a closed and open thoracic cage, diaphragm contractile properties, and potential parenchymal remodeling. MPS IIIA mice had increased compliance and airway resistance and reduced tissue damping and elastance compared with control mice. The chest wall impacted lung function as observed by an increase in airway resistance and a decrease in peripheral energy dissipation in the open compared with the closed thoracic cage state in MPS IIIA mice. Diaphragm contractile forces showed a decrease in peak twitch force, maximum specific force, and the force-frequency relationship but no change in muscle fiber cross-sectional area in MPS IIIA mice compared with control mice. Design-based stereology did not reveal any parenchymal remodeling or destruction of alveolar septa in the MPS IIIA mouse lung. In conclusion, the increased storage of HS which leads to biochemical and biophysical changes in pulmonary surfactant also affects lung and diaphragm function, but has no impact on lung or diaphragm structure at this stage of the disease.NEW & NOTEWORTHY Heparan sulfate storage in the lungs of mucopolysaccharidosis type IIIA (MPS IIIA) mice leads to changes in lung function consistent with those of an obstructive lung disease and includes an increase in lung compliance and airway resistance and a decrease in tissue elastance. In addition, diaphragm muscle contractile strength is reduced, potentially further contributing to lung function impairment. However, no changes in parenchymal lung structure were observed in mice at 20 wk of age.
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Affiliation(s)
- Tamara L Paget
- Mechanisms in Cell Biology and Diseases Research Concentration, Clinical & Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Alexander N Larcombe
- Respiratory Environmental Health, Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth, Western Australia, Australia
- Occupation, Environment & Safety, School of Population Health, Curtin University, Perth, Western Australia, Australia
| | - Gavin J Pinniger
- School of Human Sciences, The University of Western Australia, Crawley, Western Australia, Australia
| | - Irene Tsioutsias
- School of Human Sciences, The University of Western Australia, Crawley, Western Australia, Australia
| | - Jan Philipp Schneider
- Hannover Medical School, Institute of Functional and Applied Anatomy, Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover Medical School, Hannover, Germany
| | - Emma J Parkinson-Lawrence
- Mechanisms in Cell Biology and Diseases Research Concentration, Clinical & Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Sandra Orgeig
- Mechanisms in Cell Biology and Diseases Research Concentration, Clinical & Health Sciences, University of South Australia, Adelaide, South Australia, Australia
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2
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Fouzas S, Vervenioti A, Tsintoni A, Dassios T, Karatza AA, Dimitriou G. Diaphragmatic muscle function in term and preterm infants. Eur J Pediatr 2023; 182:5693-5699. [PMID: 37831303 PMCID: PMC10746574 DOI: 10.1007/s00431-023-05247-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 09/27/2023] [Accepted: 09/28/2023] [Indexed: 10/14/2023]
Abstract
We aimed to assess the determinants of diaphragmatic function in term and preterm infants. 149 infants (56 term; 93 preterm, of whom 14 were diagnosed with bronchopulmonary dysplasia-BPD) were studied before discharge. Diaphragmatic function was assessed by measurement of the maximum transdiaphragmatic pressure (Pdimax)-a measure of diaphragmatic strength, and the pressure-time index of the diaphragm (PTIdi)-a measure of the load-to-capacity ratio of the diaphragm. The Pdimax was higher in term than preterm infants without BPD (90.1 ± 16.3 vs 81.1 ± 11.8 cmH2O; P = 0.001). Term-born infants also had lower PTIdi compared to preterms without BPD (0.052 ± 0.014 vs 0.060 ± 0.017; P = 0.006). In term and preterm infants without BPD, GA was the most significant predictor of Pdimax and PTIdi, independently of the duration of mechanical ventilation and oxygen support. In infants with GA < 32 weeks (n = 30), the Pdimax was higher in infants without BPD compared to those with BPD (76.1 ± 11.1 vs 65.2 ± 11.9 cmH2O; P = 0.015). Preterms without BPD also had lower PTIdi compared to those with BPD (0.069 ± 0.016 vs 0.109 ± 0.017; P < 0.001). In this subgroup, GA was the only significant independent determinant of Pdimax, while BPD and the GA were significant determinants of the PTIdi. Conclusions: Preterm infants present lower diaphragmatic strength and impaired ability to sustain the generated force over time, which renders them prone to diaphragmatic fatigue. In very preterm infants, BPD may further aggravate diaphragmatic function. What is Known: • The diaphragm of preterm infants has limited capacity to undertake the work of breathing effectively. • The maximum transdiaphragmatic pressure (a measure of diaphragmatic strength) and the pressure-time index of the diaphragm (a measure of the load-to-capacity ratio of the muscle) have not been extensively assessed in small infants. What is New: • Preterm infants have lower diaphragmatic strength and impaired ability to sustain the generated force over time, which renders them prone to diaphragmatic fatigue. • In very preterm infants, bronchopulmonary dysplasia may further impair diaphragmatic function.
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Affiliation(s)
- Sotirios Fouzas
- Neonatal Intensive Care Unit, Department of Paediatrics, University of Patras School of Medicine, Rio, Patras, 26500, Greece
| | - Aggeliki Vervenioti
- Neonatal Intensive Care Unit, Department of Paediatrics, University of Patras School of Medicine, Rio, Patras, 26500, Greece
| | - Asimina Tsintoni
- Neonatal Intensive Care Unit, Department of Paediatrics, University of Patras School of Medicine, Rio, Patras, 26500, Greece
| | - Theodore Dassios
- Neonatal Intensive Care Unit, Department of Paediatrics, University of Patras School of Medicine, Rio, Patras, 26500, Greece.
| | - Ageliki A Karatza
- Neonatal Intensive Care Unit, Department of Paediatrics, University of Patras School of Medicine, Rio, Patras, 26500, Greece
| | - Gabriel Dimitriou
- Neonatal Intensive Care Unit, Department of Paediatrics, University of Patras School of Medicine, Rio, Patras, 26500, Greece
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Panneflek TJR, Kuypers KLAM, Polglase GR, Hooper SB, van den Akker T, Te Pas AB. Effect of clinical chorioamnionitis on breathing effort in premature infants at birth: a retrospective case-control study. Arch Dis Child Fetal Neonatal Ed 2022; 108:280-285. [PMID: 36418158 DOI: 10.1136/archdischild-2022-324695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 11/15/2022] [Indexed: 11/24/2022]
Abstract
RATIONALE Antenatal inflammation, usually associated with chorioamnionitis, is a major cause of premature birth. As inflammation could depress respiratory drive, we have examined the effect of clinical chorioamnionitis (CCA) on spontaneous breathing in premature infants at birth. METHODS Infants with CCA born <30 weeks' gestation were matched with control infants based on gestational age (±6 days), birth weight (±300 g), antenatal corticosteroids, sex and general anaesthesia. The primary outcome was breathing effort, assessed as minute volume (MV) of spontaneous breathing. We also measured tidal volume (Vt), respiratory rate (RR) and apnoea in the first 5 min and additional physiological parameters in the first 10 min after start of respiratory support. RESULTS Ninety-two infants were included (n=46 CCA infants vs n=46 controls; median (IQR) gestational age 26+4 (25+0-27+6) vs 26+6 (25+1-28+3) weeks). MV and Vt were significantly lower (MV: 43 (17-93) vs 70 (31-119) mL/kg/min, p=0.043; Vt: 2.6 (1.9-3.6) vs 2.9 (2.2-4.8) mL/kg/breath, p=0.046), whereas RR was similar in CCA infants compared with controls. Incidence of apnoea was higher (5 (2-6) vs 2 (1-4), p=0.002), and total duration of apnoea was longer (90 (21-139) vs 35 (12-98) s, p=0.025) in CCA infants. CCA infants took significantly longer to reach an oxygen saturation >80% (3:37 (2:10-4:29) vs 2:25 (1:06-3:52) min, p=0.016) and had a lower oxygen saturation at 5 min (77 (66-92) vs 91 (68-94) %, p=0.028), despite receiving more oxygen (62 (48-76) vs 54 (43-73) %, p=0.036). CONCLUSION CCA is associated with reduced breathing effort and oxygenation in premature infants at birth.
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Affiliation(s)
- Timothy J R Panneflek
- Division of Neonatology, Department of Paediatrics, Willem-Alexander Children's Hospital, Leiden University Medical Centre, Leiden, the Netherlands
| | - Kristel L A M Kuypers
- Division of Neonatology, Department of Paediatrics, Willem-Alexander Children's Hospital, Leiden University Medical Centre, Leiden, the Netherlands
| | - Graeme R Polglase
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia.,Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC, Australia
| | - Stuart B Hooper
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia.,Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC, Australia
| | - Thomas van den Akker
- Department of Obstetrics, Leids Universitair Medisch Centrum, Leiden, the Netherlands.,Athena Institute, VU University, Amsterdam, the Netherlands
| | - Arjan B Te Pas
- Division of Neonatology, Department of Paediatrics, Willem-Alexander Children's Hospital, Leiden University Medical Centre, Leiden, the Netherlands
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Damiano S, Longobardi C, Salzano A, D’Angelo L, Amenta M, Maggiolino A, De Palo P, Claps S, Rufrano D, Iannaccone F, Matera R, Ciarcia R. Red orange and lemon extract preserve from oxidative stress, DNA damage and inflammatory status in lambs. ITALIAN JOURNAL OF ANIMAL SCIENCE 2022. [DOI: 10.1080/1828051x.2022.2056527] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Sara Damiano
- Dipartimento di Medicina Veterinaria e Produzioni Animali, Università degli Studi di Napoli Federico II, Napoli, Italia
| | - Consiglia Longobardi
- Dipartimento di Salute Mentale, Fisica e Medicina Preventiva, Università della Campania "Luigi Vanvitelli", Napoli Italia
| | - Angela Salzano
- Dipartimento di Medicina Veterinaria e Produzioni Animali, Università degli Studi di Napoli Federico II, Napoli, Italia
| | - Livia D’Angelo
- Dipartimento di Medicina Veterinaria e Produzioni Animali, Università degli Studi di Napoli Federico II, Napoli, Italia
| | - Margherita Amenta
- Consiglio per la Ricerca e l’Economia Agraria (CREA)— Centro di Ricerca per l’Olivo, Frutticultura e Agrumi, Acireale, Italia
| | - Aristide Maggiolino
- Dipartimento di Medicina Veterinaria, Università degli Studi di Bari“Aldo Moro”, Valenzano (BA), Italy
| | - Pasquale De Palo
- Dipartimento di Medicina Veterinaria, Università degli Studi di Bari“Aldo Moro”, Valenzano (BA), Italy
| | - Salvatore Claps
- Consiglio per la Ricerca e l’Economia Agraria (CREA) – Centro di Ricerca per le Produzioni Animali e l’Acquacoltura, Bella Muro (PZ), Italia
| | - Domenico Rufrano
- Consiglio per la Ricerca e l’Economia Agraria (CREA) – Centro di Ricerca per le Produzioni Animali e l’Acquacoltura, Bella Muro (PZ), Italia
| | - Francesco Iannaccone
- Dipartimento di Scienze Agro-Ambientali e Territoriali (DISAAT), Università degli Studi di Bari “Aldo Moro”, Bari, Italia
| | - Roberta Matera
- Dipartimento di Medicina Veterinaria e Produzioni Animali, Università degli Studi di Napoli Federico II, Napoli, Italia
| | - Roberto Ciarcia
- Dipartimento di Medicina Veterinaria e Produzioni Animali, Università degli Studi di Napoli Federico II, Napoli, Italia
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Dassios T, Vervenioti A, Dimitriou G. Respiratory muscle function in the newborn: a narrative review. Pediatr Res 2022; 91:795-803. [PMID: 33875805 PMCID: PMC8053897 DOI: 10.1038/s41390-021-01529-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 03/24/2021] [Accepted: 03/29/2021] [Indexed: 02/02/2023]
Abstract
Our aim was to summarise the current evidence and methods used to assess respiratory muscle function in the newborn, focusing on current and future potential clinical applications. The respiratory muscles undertake the work of breathing and consist mainly of the diaphragm, which in the newborn is prone to dysfunction due to lower muscle mass, flattened shape and decreased content of fatigue-resistant muscle fibres. Premature infants are prone to diaphragmatic dysfunction due to limited reserves and limited capacity to generate force and avoid fatigue. Methods to assess the respiratory muscles in the newborn include electromyography, maximal respiratory pressures, assessment for thoraco-abdominal asynchrony and composite indices, such as the pressure-time product and the tension time index. Recently, there has been significant interest and a growing body of research in assessing respiratory muscle function using bedside ultrasonography. Neurally adjusted ventilator assist is a novel ventilation mode, where the level of the respiratory support is determined by the diaphragmatic electrical activity. Prolonged mechanical ventilation, hypercapnia and hypoxia, congenital anomalies and systemic or respiratory infection can negatively impact respiratory muscle function in the newborn, while caffeine and synchronised or volume-targeted ventilation have a positive effect on respiratory muscle function compared to conventional, non-triggered or pressure-limited ventilation, respectively. IMPACT: Respiratory muscle function is impaired in prematurely born neonates and infants with congenital anomalies, such as congenital diaphragmatic hernia. Respiratory muscle function is negatively affected by prolonged ventilation and infection and positively affected by caffeine and synchronised compared to non-synchronised ventilation modes. Point-of-care diaphragmatic ultrasound and neurally adjusted ventilator assist are recent diagnostic and therapeutic technological developments with significant clinical applicability.
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Affiliation(s)
- Theodore Dassios
- Department of Women and Children's Health, King's College London, London, UK.
- Department of Paediatrics, University of Patras, Patras, Greece.
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6
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Is Mitochondrial Oxidative Stress the Key Contributor to Diaphragm Atrophy and Dysfunction in Critically Ill Patients? Crit Care Res Pract 2020; 2020:8672939. [PMID: 32377432 PMCID: PMC7191397 DOI: 10.1155/2020/8672939] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 03/10/2020] [Accepted: 03/27/2020] [Indexed: 02/08/2023] Open
Abstract
Diaphragm dysfunction is prevalent in the progress of respiratory dysfunction in various critical illnesses. Respiratory muscle weakness may result in insufficient ventilation, coughing reflection suppression, pulmonary infection, and difficulty in weaning off respirators. All of these further induce respiratory dysfunction and even threaten the patients' survival. The potential mechanisms of diaphragm atrophy and dysfunction include impairment of myofiber protein anabolism, enhancement of myofiber protein degradation, release of inflammatory mediators, imbalance of metabolic hormones, myonuclear apoptosis, autophagy, and oxidative stress. Among these contributors, mitochondrial oxidative stress is strongly implicated to play a key role in the process as it modulates diaphragm protein synthesis and degradation, induces protein oxidation and functional alteration, enhances apoptosis and autophagy, reduces mitochondrial energy supply, and is regulated by inflammatory cytokines via related signaling molecules. This review aims to provide a concise overview of pathological mechanisms of diaphragmatic dysfunction in critically ill patients, with special emphasis on the role and modulating mechanisms of mitochondrial oxidative stress.
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7
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Francis MR, Pinniger GJ, Noble PB, Wang KCW. Intrauterine growth restriction affects diaphragm function in adult female and male mice. Pediatr Pulmonol 2020; 55:229-235. [PMID: 31535471 DOI: 10.1002/ppul.24519] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Accepted: 08/30/2019] [Indexed: 01/10/2023]
Abstract
BACKGROUND In utero diaphragm development is critically important for postnatal respiratory function and any disturbance to fetal development may lead to diaphragm dysfunction and respiratory complications in the postnatal period. Intrauterine growth restriction (IUGR) has been shown to affect respiratory function in a sex-dependent manner; however, the effect of IUGR on diaphragm function is unknown. AIM This study used a maternal hypoxia-induced mouse model of IUGR to investigate the impact of IUGR on diaphragm function and structure in male and female adult offspring. MATERIALS AND METHODS Pregnant BALB/c mice were housed under hypoxic conditions (10.5% O2 ) from gestational days 11 to 17.5 and then returned to normoxic conditions. Control mice were housed under normoxic conditions throughout pregnancy. At 8 weeks of age, offspring were euthanized and diaphragms isolated for functional assessment in organ bath experiments and for histological analysis. RESULTS IUGR offspring were lighter at birth and remained lighter at 8 weeks of age compared to Controls. While diaphragm force (maximal or twitch) was not affected by treatment or sex, the IUGR group exhibited a longer half-relaxation time after twitch contractions compared to Control. Female offspring had a lower maximum rate of force development and higher fatigue resistance compared to males, independent of IUGR. There was no difference in the diaphragm myofibre cross-sectional area between groups or sexes. CONCLUSION Sex and IUGR independently affect diaphragm contraction in adult mice without changes in structure. This study demonstrates that IUGR affects diaphragm contractile function in later life and could impair respiratory function if exacerbated under conditions of increased respiratory load.
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Affiliation(s)
- Maddison R Francis
- School of Human Sciences, The University of Western Australia, Crawley, Western Australia, Australia
| | - Gavin J Pinniger
- School of Human Sciences, The University of Western Australia, Crawley, Western Australia, Australia
| | - Peter B Noble
- School of Human Sciences, The University of Western Australia, Crawley, Western Australia, Australia
| | - Kimberley C W Wang
- School of Human Sciences, The University of Western Australia, Crawley, Western Australia, Australia.,Telethon Kids Institute, The University of Western Australia, Perth, Western Australia, Australia
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8
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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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9
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Hydrogen Sulfide Alleviates Lipopolysaccharide-Induced Diaphragm Dysfunction in Rats by Reducing Apoptosis and Inflammation through ROS/MAPK and TLR4/NF- κB Signaling Pathways. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:9647809. [PMID: 29977458 PMCID: PMC5994286 DOI: 10.1155/2018/9647809] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 04/11/2018] [Accepted: 04/29/2018] [Indexed: 12/16/2022]
Abstract
Diaphragm dysfunction is an important clinical problem worldwide. Hydrogen sulfide (H2S) is involved in many physiological and pathological processes in mammals. However, the effect and mechanism of H2S in diaphragm dysfunction have not been fully elucidated. In this study, we detected that the level of H2S was decreased in lipopolysaccharide- (LPS-) treated L6 cells. Treatment with H2S increased the proliferation and viability of LPS-treated L6 cells. We found that H2S decreased reactive oxygen species- (ROS-) induced apoptosis through the mitogen-activated protein kinase (MAPK) signaling pathway in LPS-treated L6 cells. Administration of H2S alleviated LPS-induced inflammation by mediating the toll-like receptor-4 (TLR-4)/nuclear factor-kappa B (NF-κB) signaling pathway in L6 cells. Furthermore, H2S improved diaphragmatic function and structure through the reduction of inflammation and apoptosis in the diaphragm of septic rats. In conclusion, these findings indicate that H2S ameliorates LPS-induced diaphragm dysfunction in rats by reducing apoptosis and inflammation through ROS/MAPK and TLR4/NF-κB signaling pathways. Novel slow-releasing H2S donors can be designed and applied for the treatment of diaphragm dysfunction.
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10
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Karisnan K, Mahzabin T, Bakker AJ, Song Y, Noble PB, Pillow JJ, Pinniger GJ. Gestational age at time of in utero lipopolysaccharide exposure influences the severity of inflammation-induced diaphragm weakness in lambs. Am J Physiol Regul Integr Comp Physiol 2017; 314:R523-R532. [PMID: 29212808 DOI: 10.1152/ajpregu.00150.2017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The preterm diaphragm is functionally immature compared with its term counterpart. In utero inflammation further exacerbates preterm diaphragm dysfunction. We hypothesized that preterm lambs are more vulnerable to in utero inflammation-induced diaphragm dysfunction compared with term lambs. Pregnant ewes received intra-amniotic (IA) injections of saline or 10 mg lipopolysaccharide (LPS) 2 or 7 days before delivery at 121 days (preterm) or ∼145 days (term) of gestation. Diaphragm contractile function was assessed in vitro. Plasma cytokines, diaphragm myosin heavy chain (MHC) isoforms, and oxidative stress were evaluated. Maximum diaphragm force in preterm control lambs was significantly lower (22%) than in term control lambs ( P < 0.001). Despite similar inflammatory cytokine responses to in utero LPS exposure, diaphragm function in preterm and term lambs was affected differentially. In term lambs, maximum force after a 2-day LPS exposure was significantly lower than in controls (by ~20%, P < 0.05). In preterm lambs, maximum forces after 2-day and 7-day LPS exposures were significantly lower than in controls (by ~30%, P < 0.05). Peak twitch force after LPS exposure was significantly lower in preterm than in controls, but not in term lambs. In term lambs, LPS exposure increased the proportion of MHC-I fibers, increased twitch contraction times, and increased fatigue resistance relative to controls. In preterm diaphragm, the cross-sectional area of embryonic MHC fibers was significantly lower after 7-day versus 2-day LPS exposures. We conclude that preterm lambs are more vulnerable to IA LPS-induced diaphragm dysfunction than term lambs. In utero inflammation exacerbates diaphragm dysfunction and may increase susceptibility to postnatal respiratory failure.
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Affiliation(s)
- Kanakeswary Karisnan
- School of Human Sciences, The University of Western Australia , Crawley , Australia.,School of Medicine, Perdana University -Royal College of Surgeons in Ireland , Selangor , Malaysia
| | - Tanzila Mahzabin
- School of Human Sciences, The University of Western Australia , Crawley , Australia
| | - Anthony J Bakker
- School of Human Sciences, The University of Western Australia , Crawley , Australia
| | - Yong Song
- School of Human Sciences, The University of Western Australia , Crawley , Australia.,Centre for Neonatal Research and Education, School of Paediatrics and Child Health, The University of Western Australia , Crawley , Australia.,School of Medicine, Perdana University -Royal College of Surgeons in Ireland , Selangor , Malaysia
| | - Peter B Noble
- School of Human Sciences, The University of Western Australia , Crawley , Australia.,Centre for Neonatal Research and Education, School of Paediatrics and Child Health, The University of Western Australia , Crawley , Australia
| | - J Jane Pillow
- School of Human Sciences, The University of Western Australia , Crawley , Australia.,Centre for Neonatal Research and Education, School of Paediatrics and Child Health, The University of Western Australia , Crawley , Australia
| | - Gavin J Pinniger
- School of Human Sciences, The University of Western Australia , Crawley , Australia
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11
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LaRosa DA, Ellery SJ, Walker DW, Dickinson H. Understanding the Full Spectrum of Organ Injury Following Intrapartum Asphyxia. Front Pediatr 2017; 5:16. [PMID: 28261573 PMCID: PMC5313537 DOI: 10.3389/fped.2017.00016] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 01/23/2017] [Indexed: 11/13/2022] Open
Abstract
Birth asphyxia is a significant global health problem, responsible for ~1.2 million neonatal deaths each year worldwide. Those who survive often suffer from a range of health issues including brain damage-manifesting as cerebral palsy (CP)-respiratory insufficiency, cardiovascular collapse, and renal dysfunction, to name a few. Although the majority of research is directed toward reducing the brain injury that results from intrapartum birth asphyxia, the multi-organ injury observed in surviving neonates is of equal importance. Despite the advent of hypothermia therapy for the treatment of hypoxic-ischemic encephalopathy (HIE), treatment options following asphyxia at birth remain limited, particularly in low-resource settings where the incidence of birth asphyxia is highest. Furthermore, although cooling of the neonate results in improved neurological outcomes for a small proportion of treated infants, it does not provide any benefit to the other organ systems affected by asphyxia at birth. The aim of this review is to summarize the current knowledge of the multi-organ effects of intrapartum asphyxia, with particular reference to the findings from our laboratory using the precocial spiny mouse to model birth asphyxia. Furthermore, we reviewed the current treatments available for neonates who have undergone intrapartum asphyxia, and highlight the emergence of maternal dietary creatine supplementation as a preventative therapy, which has been shown to provide multi-organ protection from birth asphyxia-induced injury in our preclinical studies. This cheap and effective nutritional supplement may be the key to reducing birth asphyxia-induced death and disability, particularly in low-resource settings where current treatments are unavailable.
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Affiliation(s)
- Domenic A LaRosa
- Ritchie Centre, Department of Obstetrics and Gynaecology, Hudson Institute of Medical Research, Monash University, Melbourne, VIC, Australia; Department of Pediatrics, The Alpert Medical School of Brown University, Women & Infants Hospital of Rhode Island, Providence, RI, USA
| | - Stacey J Ellery
- Ritchie Centre, Department of Obstetrics and Gynaecology, Hudson Institute of Medical Research, Monash University , Melbourne, VIC , Australia
| | - David W Walker
- Ritchie Centre, Department of Obstetrics and Gynaecology, Hudson Institute of Medical Research, Monash University , Melbourne, VIC , Australia
| | - Hayley Dickinson
- Ritchie Centre, Department of Obstetrics and Gynaecology, Hudson Institute of Medical Research, Monash University , Melbourne, VIC , Australia
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Pang M, Bai XY, Li Y, Bai JZ, Yuan LR, Ren SA, Hu XY, Zhang XR, Yu BF, Guo R, Wang HL. Label-free LC-MS/MS shotgun proteomics to investigate the anti-inflammatory effect of rCC16. Mol Med Rep 2016; 14:4496-4504. [PMID: 27748820 PMCID: PMC5101986 DOI: 10.3892/mmr.2016.5841] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 08/18/2016] [Indexed: 12/30/2022] Open
Abstract
Clara cell protein (CC16) is an anti-inflammatory protein, which is expressed in the airway epithelium. It is involved in the development of airway inflammatory diseases, including chronic obstructive pulmonary disease and asthma. However, the exact molecular mechanism underlying its anti‑inflammatory action remains to be fully elucidated. The aim of the present study was to define the protein profiles of the anti‑inflammatory effect of CC16 in lipopolysaccharide (LPS)‑treated rat tracheal epithelial (RTE) cells using shotgun proteomics. Protein extracts were obtained from control RTE cells, RTE cells treated with LPS and RTE cells treated with LPS and recombinant CC16 (rCC16). Subsequent label‑free quantification and bioinformatics analyses identified 12 proteins that were differentially expressed in the three treatment groups as a cluster of five distinct groups according to their molecular functions. Five of the twelve proteins were revealed to be associated with the cytoskeleton: Matrix metalloproteinase‑9, myosin heavy chain 10, actin‑related protein‑3 homolog, elongation factor 1‑α‑1 (EF‑1‑α‑1), and acidic ribosomal phosphoprotein P0. Five of the twelve proteins were associated with cellular proliferation: DNA‑dependent protein kinase catalytic subunit, EF‑1‑α‑1, tyrosine 3‑monooxygenase, caspase recruitment domain (CARD) protein 12 and adenosylhomocysteinase (SAHH) 3. Three proteins were associated with gene regulation: EF‑1‑α‑1, SAHH 3 and acidic ribosomal phosphoprotein P0. Three proteins were associated with inflammation: Tyrosine 3‑monooxygenase, CARD protein 12 and statin‑related protein. ATPase (H+‑transporting, V1 subunit A, isoform 1) was revealed to be associated with energy metabolism, and uridine diphosphate glycosyltransferase 1 family polypeptide A8 with drug metabolism and detoxification. The identified proteins were further validated using reverse transcription‑quantitative polymerase chain reaction. These protein profiles, and their interacting protein network, may facilitate the elucidation of the molecular mechanisms underlying the anti‑inflammatory effects of CC16.
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Affiliation(s)
- Min Pang
- Respiratory Department, The First Affiliated Hospital, Shanxi Medical University, Taiyuan, Shanxi 030001, P.R. China
| | - Xin-Yan Bai
- Department of Biochemistry and Molecular Biology, Shanxi Medical University, Taiyuan, Shanxi 030001, P.R. China
| | - Yan Li
- Fan‑Xing Biological Technology Co., Ltd., Beijing 010000, P.R. China
| | - Ji-Zhong Bai
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland 1142, New Zealand
| | - Li-Rong Yuan
- Respiratory Department, The First Affiliated Hospital, Shanxi Medical University, Taiyuan, Shanxi 030001, P.R. China
| | - Shou-An Ren
- Respiratory Department, The First Affiliated Hospital, Shanxi Medical University, Taiyuan, Shanxi 030001, P.R. China
| | - Xiao-Yun Hu
- Respiratory Department, The First Affiliated Hospital, Shanxi Medical University, Taiyuan, Shanxi 030001, P.R. China
| | - Xin-Ri Zhang
- Respiratory Department, The First Affiliated Hospital, Shanxi Medical University, Taiyuan, Shanxi 030001, P.R. China
| | - Bao-Feng Yu
- Department of Biochemistry and Molecular Biology, Shanxi Medical University, Taiyuan, Shanxi 030001, P.R. China
| | - Rui Guo
- Department of Biochemistry and Molecular Biology, Shanxi Medical University, Taiyuan, Shanxi 030001, P.R. China
| | - Hai-Long Wang
- Department of Biochemistry and Molecular Biology, Shanxi Medical University, Taiyuan, Shanxi 030001, P.R. China
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Maternal Creatine Supplementation during Pregnancy Prevents Long-Term Changes in Diaphragm Muscle Structure and Function after Birth Asphyxia. PLoS One 2016; 11:e0149840. [PMID: 26930669 PMCID: PMC4773130 DOI: 10.1371/journal.pone.0149840] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 01/14/2016] [Indexed: 11/03/2022] Open
Abstract
Using a model of birth asphyxia, we previously reported significant structural and functional deficits in the diaphragm muscle in spiny mice, deficits that are prevented by supplementing the maternal diet with 5% creatine from mid-pregnancy. The long-term effects of this exposure are unknown. Pregnant spiny mice were fed control or 5% creatine-supplemented diet for the second half of pregnancy, and fetuses were delivered by caesarean section with or without 7.5 min of in-utero asphyxia. Surviving pups were raised by a cross-foster dam until 33±2 days of age when they were euthanized to obtain the diaphragm muscle for ex-vivo study of twitch tension and muscle fatigue, and for structural and enzymatic analyses. Functional analysis of the diaphragm revealed no differences in single twitch contractile parameters between any groups. However, muscle fatigue, induced by stimulation of diaphragm strips with a train of pulses (330 ms train/sec, 40 Hz) for 300 sec, was significantly greater for asphyxia pups compared with controls (p<0.05), and this did not occur in diaphragms of creatine + asphyxia pups. Birth asphyxia resulted in a significant increase in the proportion of glycolytic, fast-twitch fibres and a reduction in oxidative capacity of Type I and IIb fibres in male offspring, as well as reduced cross-sectional area of all muscle fibre types (Type I, IIa, IIb/d) in both males and females at 33 days of age. None of these changes were observed in creatine + asphyxia animals. Thus, the changes in diaphragm fatigue and structure induced by birth asphyxia persist long-term but are prevented by maternal creatine supplementation.
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Karisnan K, Bakker AJ, Song Y, Noble PB, Pillow JJ, Pinniger GJ. Gestational age at initial exposure toin uteroinflammation influences the extent of diaphragm dysfunction in preterm lambs. Respirology 2015; 20:1255-62. [DOI: 10.1111/resp.12615] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 05/19/2015] [Accepted: 06/28/2015] [Indexed: 01/27/2023]
Affiliation(s)
- Kanakeswary Karisnan
- School of Anatomy, Physiology and Human Biology; University of Western Australia; Perth Western Australia Australia
| | - Anthony J. Bakker
- School of Anatomy, Physiology and Human Biology; University of Western Australia; Perth Western Australia Australia
- Centre for Neonatal Research and Education; School of Paediatrics and Child Health; University of Western Australia; Perth Western Australia Australia
| | - Yong Song
- School of Anatomy, Physiology and Human Biology; University of Western Australia; Perth Western Australia Australia
| | - Peter B. Noble
- School of Anatomy, Physiology and Human Biology; University of Western Australia; Perth Western Australia Australia
| | - J. Jane Pillow
- School of Anatomy, Physiology and Human Biology; University of Western Australia; Perth Western Australia Australia
- Centre for Neonatal Research and Education; School of Paediatrics and Child Health; University of Western Australia; Perth Western Australia Australia
| | - Gavin Jon Pinniger
- School of Anatomy, Physiology and Human Biology; University of Western Australia; Perth Western Australia Australia
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Karisnan K, Bakker AJ, Song Y, Noble PB, Pillow JJ, Pinniger GJ. Interleukin-1 receptor antagonist protects against lipopolysaccharide induced diaphragm weakness in preterm lambs. PLoS One 2015; 10:e0124390. [PMID: 25860718 PMCID: PMC4393095 DOI: 10.1371/journal.pone.0124390] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 03/13/2015] [Indexed: 12/21/2022] Open
Abstract
Chorioamnionitis (inflammation of the fetal membranes) is strongly associated with preterm birth and in utero exposure to inflammation significantly impairs contractile function in the preterm lamb diaphragm. The fetal inflammatory response to intra-amniotic (IA) lipopolysaccharide (LPS) is orchestrated via interleukin 1 (IL-1). We aimed to determine if LPS induced contractile dysfunction in the preterm diaphragm is mediated via the IL-1 pathway. Pregnant ewes received IA injections of recombinant human IL-1 receptor antagonist (rhIL-1ra) (Anakinra; 100 mg) or saline (Sal) 3 h prior to second IA injections of LPS (4 mg) or Sal at 119d gestational age (GA). Preterm lambs were killed after delivery at 121d GA (term = 150 d). Muscle fibres dissected from the right hemi-diaphragm were mounted in an in vitro muscle test system for assessment of contractile function. The left hemi-diaphragm was snap frozen for molecular and biochemical analyses. Maximum specific force in lambs exposed to IA LPS (Sal/LPS group) was 25% lower than in control lambs (Sal/Sal group; p=0.025). LPS-induced diaphragm weakness was associated with higher plasma IL-6 protein, diaphragm IL-1β mRNA and oxidised glutathione levels. Pre-treatment with rhIL-1ra (rhIL-1ra/LPS) ameliorated the LPS-induced diaphragm weakness and blocked systemic and local inflammatory responses, but did not prevent the rise in oxidised glutathione. These findings indicate that LPS induced diaphragm dysfunction is mediated via IL-1 and occurs independently of oxidative stress. Therefore, the IL-1 pathway represents a potential therapeutic target in the management of impaired diaphragm function in preterm infants.
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Affiliation(s)
- Kanakeswary Karisnan
- School of Anatomy, Physiology and Human Biology, University of Western Australia, Crawley, WA, Australia
| | - Anthony J. Bakker
- School of Anatomy, Physiology and Human Biology, University of Western Australia, Crawley, WA, Australia
| | - Yong Song
- School of Anatomy, Physiology and Human Biology, University of Western Australia, Crawley, WA, Australia
- Centre for Neonatal Research and Education, School of Paediatrics and Child Health, University of Western Australia, Crawley, WA, Australia
| | - Peter B. Noble
- School of Anatomy, Physiology and Human Biology, University of Western Australia, Crawley, WA, Australia
- Centre for Neonatal Research and Education, School of Paediatrics and Child Health, University of Western Australia, Crawley, WA, Australia
| | - J. Jane Pillow
- School of Anatomy, Physiology and Human Biology, University of Western Australia, Crawley, WA, Australia
- Centre for Neonatal Research and Education, School of Paediatrics and Child Health, University of Western Australia, Crawley, WA, Australia
| | - Gavin J. Pinniger
- School of Anatomy, Physiology and Human Biology, University of Western Australia, Crawley, WA, Australia
- * E-mail:
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Song Y, Demmer DL, Pinniger GJ, Lavin T, MacMillan MV, Pillow JJ, Bakker AJ. Effect of maternal steroid on developing diaphragm integrity. PLoS One 2014; 9:e93224. [PMID: 24681552 PMCID: PMC3969349 DOI: 10.1371/journal.pone.0093224] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Accepted: 03/03/2014] [Indexed: 01/21/2023] Open
Abstract
Antenatal steroids reduce the severity of initial respiratory distress of premature newborn babies but may have an adverse impact on other body organs. The study aimed to examine the effect of maternal steroids on postnatal respiratory muscle function during development and elucidate the mechanisms underlying the potential myopathy in newborn rats. Pregnant rats were treated with intramuscular injections of 0.5 mg/kg betamethasone 7 d and 3 d before birth. Newborn diaphragms were dissected for assessment of contractile function at 2 d, 7 d or 21 d postnatal age (PNA), compared with age-matched controls. The expression of myosin heavy chain (MHC) isoforms and atrophy-related genes and activity of intracellular molecular signalling were measured using quantitative PCR and/or Western blot. With advancing PNA, neonatal MHC gene expression decreased progressively while MHC IIb and IIx isoforms increased. Protein metabolic signalling showed high baseline activity at 2 d PNA, and significantly declined at 7 d and 21 d. Antenatal administration of betamethasone significantly decreased diaphragm force production, fatigue resistance, total fast fibre content and anabolic signalling activity (Akt and 4E-BP1) in 21 d diaphragm. These responses were not observed in 2 d or 7 d postnatal diaphragm. Results demonstrate that maternal betamethasone treatment causes postnatal diaphragmatic dysfunction at 21 d PNA, which is attributed to MHC II protein loss and impairment of the anabolic signalling pathway. Developmental modifications in MHC fibre composition and protein signalling account for the age-specific diaphragm dysfunction.
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Affiliation(s)
- Yong Song
- School of Anatomy, Physiology and Human Biology, The University of Western Australia, Perth, Western Australia, Australia
- Centre for Neonatal Research and Education, School of Paediatrics and Child Health, The University of Western Australia, Perth, Western Australia, Australia
| | - Denise L. Demmer
- School of Anatomy, Physiology and Human Biology, The University of Western Australia, Perth, Western Australia, Australia
| | - Gavin J. Pinniger
- School of Anatomy, Physiology and Human Biology, The University of Western Australia, Perth, Western Australia, Australia
| | - Tina Lavin
- School of Anatomy, Physiology and Human Biology, The University of Western Australia, Perth, Western Australia, Australia
- Centre for Neonatal Research and Education, School of Paediatrics and Child Health, The University of Western Australia, Perth, Western Australia, Australia
| | - Mia V. MacMillan
- School of Anatomy, Physiology and Human Biology, The University of Western Australia, Perth, Western Australia, Australia
| | - Jane J. Pillow
- School of Anatomy, Physiology and Human Biology, The University of Western Australia, Perth, Western Australia, Australia
- Centre for Neonatal Research and Education, School of Paediatrics and Child Health, The University of Western Australia, Perth, Western Australia, Australia
- Women and Newborns Health Service, c/-King Edward Memorial and Princess Margaret Hospitals, Perth, Western Australia, Australia
| | - Anthony J. Bakker
- School of Anatomy, Physiology and Human Biology, The University of Western Australia, Perth, Western Australia, Australia
- * E-mail:
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Song Y, Pinniger GJ, Bakker AJ, Moss TJM, Noble PB, Berry CA, Pillow JJ. Lipopolysaccharide-induced weakness in the preterm diaphragm is associated with mitochondrial electron transport chain dysfunction and oxidative stress. PLoS One 2013; 8:e73457. [PMID: 24039949 PMCID: PMC3765262 DOI: 10.1371/journal.pone.0073457] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Accepted: 07/22/2013] [Indexed: 01/27/2023] Open
Abstract
Diaphragmatic contractility is reduced in preterm lambs after lipopolysaccharide (LPS) exposure in utero. The mechanism of impaired fetal diaphragm contractility after LPS exposure is unknown. We hypothesise that in utero exposure to LPS induces a deficiency of mitochondrial complex activity and oxidative damage in the fetal diaphragm. To test this hypothesis, we used a well-established preterm ovine model of chorioamnionitis: Pregnant ewes received intra-amniotic (IA) saline or 10 mg LPS, at 2 d or 7 d prior to surgical delivery at 121 d GA (term = 150 d). The fetus was killed humanely immediately after delivery for tissue sampling. Mitochondrial fractions were prepared from the isolated diaphragm and mitochondrial electron transfer chain activities were evaluated using enzymatic assays. Oxidative stress was investigated by quantifying mitochondrial oxidative protein levels and determining antioxidant gene and protein (catalase, superoxide dismutase 2 and glutathione peroxidase 1) expression. The activity of the erythroid 2-related factor 2 (Nrf2)-mediated antioxidant signalling pathway was examined by quantifying the Nrf2 protein content of cell lysate and nuclear extract. A 2 d LPS exposure in utero significantly decreased electron transfer chain complex II and IV activity (p<0.05). A 7 d LPS exposure inhibited superoxide dismutase 2 and catalase expression at gene and protein levels, and Nrf2 pathway activity (p<0.05) compared with control and 2 d LPS groups, respectively. Diaphragm mitochondria accumulated oxidised protein after a 7 d LPS exposure. We conclude that intrauterine exposure to LPS induces mitochondrial oxidative stress and electron chain dysfunction in the fetal diaphragm, that is further exacerbated by impairment of the antioxidant signalling pathway and decreased antioxidant activity.
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Affiliation(s)
- Yong Song
- School of Anatomy, Physiology and Human Biology, The University of Western Australia, Perth, Western Australia, Australia
- Centre for Neonatal Research and Education, School of Paediatrics and Child Health, The University of Western Australia, Perth, Western Australia, Australia
| | - Gavin J. Pinniger
- School of Anatomy, Physiology and Human Biology, The University of Western Australia, Perth, Western Australia, Australia
| | - Anthony J. Bakker
- School of Anatomy, Physiology and Human Biology, The University of Western Australia, Perth, Western Australia, Australia
| | - Timothy J. M. Moss
- The Ritchie Centre, Monash Institute of Medical Research, and Department of Obstetrics & Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Peter B. Noble
- School of Anatomy, Physiology and Human Biology, The University of Western Australia, Perth, Western Australia, Australia
- Centre for Neonatal Research and Education, School of Paediatrics and Child Health, The University of Western Australia, Perth, Western Australia, Australia
| | - Clare A. Berry
- Centre for Neonatal Research and Education, School of Paediatrics and Child Health, The University of Western Australia, Perth, Western Australia, Australia
| | - Jane J. Pillow
- School of Anatomy, Physiology and Human Biology, The University of Western Australia, Perth, Western Australia, Australia
- Centre for Neonatal Research and Education, School of Paediatrics and Child Health, The University of Western Australia, Perth, Western Australia, Australia
- Women and Newborns Health Service, c/−King Edward Memorial and Princess Margaret Hospitals, Perth, Western Australia, Australia
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