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Meconium Aspiration Syndrome in Animal Models: Inflammatory Process, Apoptosis, and Surfactant Inactivation. Animals (Basel) 2022; 12:ani12233310. [PMID: 36496831 PMCID: PMC9740025 DOI: 10.3390/ani12233310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 11/18/2022] [Accepted: 11/24/2022] [Indexed: 11/29/2022] Open
Abstract
Meconium Aspiration Syndrome is a condition that causes respiratory distress in newborns due to occlusion and airway inflammation, and surfactant inactivation by meconium. This condition has been described in animal species such as canids, sheep, cattle, horses, pigs, and marine mammals. In its pathogenesis, the pulmonary epithelium activates a limited inflammatory response initiated by cytokines causing leukocyte chemotaxis, inhibition of phagocytosis, and pathogen destruction. Likewise, cytokines release participates in the apoptosis processes of pneumocytes due to the interaction of angiotensin with cytokines and the caspase pathway. Due to these reactions, the prevalent signs are lung injury, hypoxia, acidosis, and pneumonia with susceptibility to infection. Given the importance of the pathophysiological mechanism of meconium aspiration syndrome, this review aims to discuss the relevance of the syndrome in veterinary medicine. The inflammatory processes caused by meconium aspiration in animal models will be analyzed, and the cellular apoptosis and biochemical processes of pulmonary surfactant inactivation will be discussed.
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Xin Y, Xie J, Nan B, Tang C, Xiao Y, Wu Q, Lin Y, Zhang X, Shen H. Freeze-Thaw Pretreatment Can Improve Efficiency of Bacterial DNA Extraction From Meconium. Front Microbiol 2021; 12:753688. [PMID: 34956118 PMCID: PMC8695897 DOI: 10.3389/fmicb.2021.753688] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 11/18/2021] [Indexed: 11/13/2022] Open
Abstract
Although the presence of live microbes in utero remains under debate, newborn gastrointestinal bacteria are undoubtedly important to infant health. Measuring bacteria in meconium is an ideal strategy to understand this issue; however, the low efficiency of bacterial DNA extraction from meconium has limited its utilization. This study aims to improve the efficiency of bacterial DNA extraction from meconium, which generally has low levels of microflora but high levels of PCR inhibitors in the viscous matrix. The research was approved by the ethical committee of the Xiamen Maternity and Child Health Care Hospital, Xiamen, China. All the mothers delivered naturally, and their newborns were healthy. Meconium samples passed by the newborns within 24 h were collected. Each sample was scraped off of a sterile diaper, transferred to a 5-ml sterile tube, and stored at −80°C. For the assay, a freeze-thawing sample preparation protocol was designed, in which a meconium-InhibitEX buffer mixture was intentionally frozen 1–3 times at −20°C, −80°C, and (or) in liquid nitrogen. Then, DNA was extracted using a commercial kit and sequenced by 16S rDNA to verify the enhanced bacterial DNA extraction efficiency. Ultimately, we observed the following: (1) About 30 mg lyophilized meconium was the optimal amount for DNA extraction. (2) Freezing treatment for 6 h improved DNA extraction at −20°C. (3) DNA extraction efficiency was significantly higher with the immediate thaw strategy than with gradient thawing at −20°C, −80°C, and in liquid nitrogen. (4) Among the conditions of −20°C, −80°C, and liquid nitrogen, −20°C was the best freezing condition for both improving DNA extraction efficiency and preserving microbial species diversity in meconium, while liquid nitrogen was the worst condition. (5) Three freeze-thaw cycles could markedly enhance DNA extraction efficiency and preserve the species diversity of meconium microflora. We developed a feasible freeze-thaw pretreatment protocol to improve the extraction of microbial DNA from meconium, which may be beneficial for newborn bacterial colonization studies.
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Affiliation(s)
- Yuntian Xin
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China
| | - Jingxian Xie
- Department of Obstetrics, Women and Children's Hospital, School of Medicine, Xiamen University, Xiamen, China
| | - Bingru Nan
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China.,State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Chen Tang
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen, China
| | - Yunshan Xiao
- Department of Obstetrics, Women and Children's Hospital, School of Medicine, Xiamen University, Xiamen, China
| | - Quanfeng Wu
- Department of Obstetrics, Women and Children's Hospital, School of Medicine, Xiamen University, Xiamen, China
| | - Yi Lin
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen, China
| | - Xueqin Zhang
- Department of Obstetrics, Women and Children's Hospital, School of Medicine, Xiamen University, Xiamen, China
| | - Heqing Shen
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China.,State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen, China
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Echaide M, Autilio C, Arroyo R, Perez-Gil J. Restoring pulmonary surfactant membranes and films at the respiratory surface. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:1725-1739. [PMID: 28341439 DOI: 10.1016/j.bbamem.2017.03.015] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 03/14/2017] [Accepted: 03/19/2017] [Indexed: 02/08/2023]
Abstract
Pulmonary surfactant is a complex of lipids and proteins assembled and secreted by the alveolar epithelium into the thin layer of fluid coating the respiratory surface of lungs. There, surfactant forms interfacial films at the air-water interface, reducing dramatically surface tension and thus stabilizing the air-exposed interface to prevent alveolar collapse along respiratory mechanics. The absence or deficiency of surfactant produces severe lung pathologies. This review describes some of the most important surfactant-related pathologies, which are a cause of high morbidity and mortality in neonates and adults. The review also updates current therapeutic approaches pursuing restoration of surfactant operative films in diseased lungs, mainly through supplementation with exogenous clinical surfactant preparations. This article is part of a Special Issue entitled: Membrane Lipid Therapy: Drugs Targeting Biomembranes edited by Pablo V. Escribá.
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Affiliation(s)
- Mercedes Echaide
- Dept. Biochemistry, Faculty of Biology, and Research Institute "Hospital 12 de Octubre", Complutense University, Madrid, Spain
| | - Chiara Autilio
- Dept. Biochemistry, Faculty of Biology, and Research Institute "Hospital 12 de Octubre", Complutense University, Madrid, Spain
| | - Raquel Arroyo
- Dept. Biochemistry, Faculty of Biology, and Research Institute "Hospital 12 de Octubre", Complutense University, Madrid, Spain
| | - Jesus Perez-Gil
- Dept. Biochemistry, Faculty of Biology, and Research Institute "Hospital 12 de Octubre", Complutense University, Madrid, Spain.
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Kopincova J, Calkovska A. Meconium-induced inflammation and surfactant inactivation: specifics of molecular mechanisms. Pediatr Res 2016; 79:514-21. [PMID: 26679157 DOI: 10.1038/pr.2015.265] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 10/03/2015] [Indexed: 12/21/2022]
Abstract
This review summarizes neonatal meconium aspiration syndrome in light of meconium-induced inflammation and inflammatory surfactant inactivation, related to both endogenous and therapeutic exogenous surfactant. The wide effect of meconium on surfactant properties is divided into three points. Direct effect of meconium on surfactant properties refers mainly to fragmentation of dipalmitoylphosphatidylcholine and other surfactant phospholipids together with cleavage of surfactant proteins. Initiation of inflammatory response due to activation of receptors by yet unspecified compounds involves complement and Toll-like receptor activation. A possible role of lung collectins, surfactant proteins A and D, which can exert both pro- and anti-inflammatory reactions, is discussed. Initiation of inflammatory response by specified compounds in meconium reflects inflammatory functioning of cytokines, bile acids, and phospholipases contained in meconium. Unifying sketch of many interconnections in all these actions aims at providing integrated picture of inflammatory surfactant inactivation.
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Affiliation(s)
- Jana Kopincova
- Department of Physiology and Martin Biomedical Centre, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Slovak Republic
| | - Andrea Calkovska
- Department of Physiology and Martin Biomedical Centre, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Slovak Republic
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El-Gendy N, Kaviratna A, Berkland C, Dhar P. Delivery and performance of surfactant replacement therapies to treat pulmonary disorders. Ther Deliv 2013; 4:951-80. [PMID: 23919474 PMCID: PMC3840129 DOI: 10.4155/tde.13.72] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Lung surfactant is crucial for optimal pulmonary function throughout life. An absence or deficiency of surfactant can affect the surfactant pool leading to respiratory distress. Even if the coupling between surfactant dysfunction and the underlying disease is not always well understood, using exogenous surfactants as replacement is usually a standard therapeutic option in respiratory distress. Exogenous surfactants have been extensively studied in animal models and clinical trials. The present article provides an update on the evolution of surfactant therapy, types of surfactant treatment, and development of newer-generation surfactants. The differences in the performance between various surfactants are highlighted and advanced research that has been conducted so far in developing the optimal delivery of surfactant is discussed.
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Affiliation(s)
- Nashwa El-Gendy
- Department of Pharmaceutical Chemistry, The University of Kansas, 1530 W 15th Street, Lawrence, KS 66045, USA
- Department of Pharmaceutics & Industrial Pharmacy, Faculty of Pharmacy, Beni-suef University, Egypt
| | - Anubhav Kaviratna
- Department of Chemical & Petroleum Engineering, The University of Kansas, 1530 W 15th Street, Lawrence, KS 66045, USA
| | - Cory Berkland
- Department of Pharmaceutical Chemistry, The University of Kansas, 1530 W 15th Street, Lawrence, KS 66045, USA
- Department of Chemical & Petroleum Engineering, The University of Kansas, 1530 W 15th Street, Lawrence, KS 66045, USA
| | - Prajnaparamita Dhar
- Department of Chemical & Petroleum Engineering, The University of Kansas, 1530 W 15th Street, Lawrence, KS 66045, USA
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