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Gong X, Marisiddaiah R, Rubin LP. Inhibition of pulmonary β-carotene 15, 15'-oxygenase expression by glucocorticoid involves PPARα. PLoS One 2017; 12:e0181466. [PMID: 28732066 PMCID: PMC5521778 DOI: 10.1371/journal.pone.0181466] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 06/30/2017] [Indexed: 01/19/2023] Open
Abstract
β-carotene 15,15'-oxygenase (BCO1) catalyzes the first step in the conversion of dietary provitamin A carotenoids to vitamin A. This enzyme is expressed in a variety of developing and adult tissues, suggesting that its activity may regulate local retinoid synthesis. Vitamin A and related compounds (retinoids) are critical regulators of lung epithelial development, integrity, and injury repair. A balance between the actions of retinoids and glucocorticoids (GCs) promotes normal lung development and, in particular, alveolarization. Alterations in this balance, including vitamin A deficiency and GC excess, contribute to the development of chronic lung disorders. Consequently, we investigated if GCs counteract retinoid effects in alveolar epithelial cells by mechanisms involving BCO1-dependent local vitamin A metabolism. We demonstrate that BCO1 is expressed in human fetal lung tissue and human alveolar epithelial-like A549 cells. Our results indicate A549 cells metabolize β-carotene to retinal and retinoic acid (RA). GCs exposure using dexamethasone (DEX) decreases BCO1 mRNA and protein levels in A549 cells and reduces BCO1 promoter activity via inhibiting peroxisome proliferator-activated receptor γ (PPARγ) DNA binding. DEX also induces expression of PPARα, which in turn most likely causes a decrease in PPARγ/RXRα heterodimer binding to the bco1 gene promoter and consequent inhibition of bco1 gene expression. PPARα knockdown with siRNA abolishes DEX-induced suppression of BCO1 expression, confirming the requirement for PPARα in this DEX-mediated BCO1 mechanism. Taken together, these findings provide the first evidence that GCs regulate vitamin A (retinoid) signaling via inhibition of bco1 gene expression in a PPARα-dependent manner. These results explicate novel aspects of local GC:retinoid interactions that may contribute to alveolar tissue remodeling in chronic lung diseases that affect children and, possibly, adults.
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Affiliation(s)
- Xiaoming Gong
- Department of Pediatrics, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, Texas, United States of America
- * E-mail: (XG); (LPR)
| | - Raju Marisiddaiah
- All Children’s Research Institute, St. Petersburg, Florida, United States of America
| | - Lewis P. Rubin
- Department of Pediatrics, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, Texas, United States of America
- Department of Biomedical Sciences, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, Texas, United States of America
- * E-mail: (XG); (LPR)
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Tahedl D, Wirkes A, Tschanz SA, Ochs M, Mühlfeld C. How common is the lipid body-containing interstitial cell in the mammalian lung? Am J Physiol Lung Cell Mol Physiol 2014; 307:L386-94. [PMID: 24973404 DOI: 10.1152/ajplung.00131.2014] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Pulmonary lipofibroblasts are thought to be involved in lung development, regeneration, vitamin A storage, and surfactant synthesis. Most of the evidence for these important functions relies on mouse or rat studies. Therefore, the present study was designed to investigate the presence of lipofibroblasts in a variety of early postnatal and adult mammalian species (including humans) to evaluate the ability to generalize functions of this cell type for other species. For this purpose, lung samples from 14 adult mammalian species as well as from postnatal mice, rats, and humans were investigated using light and electron microscopic stereology to obtain the volume fraction and the total volume of lipid bodies. In adult animals, lipid bodies were observed only, but not in all rodents. In all other species, no lipofibroblasts were observed. In rodents, lipid body volume scaled with body mass with an exponent b = 0.73 in the power law equation. Lipid bodies were not observed in postnatal human lungs but showed a characteristic postnatal increase in mice and rats and persisted at a lower level in the adult animals. Among 14 mammalian species, lipofibroblasts were only observed in rodents. The great increase in lipid body volume during early postnatal development of the mouse lung confirms the special role of lipofibroblasts during rodent lung development. It is evident that the cellular functions of pulmonary lipofibroblasts cannot be transferred easily from rodents to other species, in particular humans.
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Affiliation(s)
- Daniel Tahedl
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
| | - André Wirkes
- Institute of Anatomy and Cell Biology, Justus-Liebig-University Gießen, Gießen, Germany
| | | | - Matthias Ochs
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany; Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany; and Cluster of Excellence REBIRTH (From Regenerative Biology to Reconstructive Therapy), Hannover, Germany
| | - Christian Mühlfeld
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany; Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany; and Cluster of Excellence REBIRTH (From Regenerative Biology to Reconstructive Therapy), Hannover, Germany
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Hadchouel A, Franco-Montoya ML, Delacourt C. Altered lung development in bronchopulmonary dysplasia. ACTA ACUST UNITED AC 2014; 100:158-67. [PMID: 24638954 DOI: 10.1002/bdra.23237] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2013] [Revised: 02/09/2014] [Accepted: 02/11/2014] [Indexed: 11/11/2022]
Abstract
Bronchopulmonary dysplasia (BPD) is the main respiratory sequela of extreme prematurity. Its pathophysiology is complex, involving interactions between host and environment, likely to be significantly influenced by genetic factors. Thus, the clinical presentation and histological lesions have evolved over time, along with the reduction in neonatal injuries, and the care of more immature children. Impaired alveolar growth, however, is a lesion consistently observed in BPD, such that it is a key feature in BPD, and is even the dominant characteristic of the so-called "new" forms of BPD. This review describes the key molecular pathways that are believed to be involved in the genesis of BPD. Much of our understanding is based on animal models, but this is increasingly being enriched by genetic approaches, and long-term respiratory functional studies.
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Affiliation(s)
- Alice Hadchouel
- INSERM, U955, IMRB, Equipe 04, Créteil, France; AP-HP, Hôpital Necker-Enfants Malades, service de Pneumologie Pédiatrique, Centre de Référence pour les Maladies Respiratoires Rares de l'Enfant, Paris, France; Université Paris-Descartes, Paris, France
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TSCHANZ S, BURRI P, WEIBEL E. A simple tool for stereological assessment of digital images: the STEPanizer. J Microsc 2011; 243:47-59. [DOI: 10.1111/j.1365-2818.2010.03481.x] [Citation(s) in RCA: 193] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Wei H, Huang HM, Li TY, Qu P, Liu YX, Chen J. Marginal vitamin A deficiency affects lung maturation in rats from prenatal to adult stage. J Nutr Sci Vitaminol (Tokyo) 2009; 55:208-14. [PMID: 19602828 DOI: 10.3177/jnsv.55.208] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
UNLABELLED Mild or marginal vitamin A deficiency (MVAD) is still a serious and widespread public health problem in pregnant women and children in developing countries. This study investigated rat lung maturation from prenatal to adult stage during pregnancy and postnatal MVAD and the recovery after postnatal vitamin A supplementation (VAS). Adult female rats and their offspring were randomized into three groups. 1. CONTROL the mothers and offspring received a normal diet.2. MVAD: The mothers and offspring received a MVAD diet.3. VAS: the mothers received MVAD diet till parturition, and then received the normal diet. The offspring of the VAS group were given low-dose vitamin A from postnatal day 1 to day 7 and received the normal diet after weaning. The lung development, structure, and collagen and elastic fiber of offspring were monitored by morphometric analysis at age 1 d, 2 and 8 wk, respectively. Lower body weight, lung weight, reduced numbers of alveoli and total alveolar surface area as well as increased alveoli septa thickness was observed in MVAD compared to that in the control animals. Increased collagen deposits and decreasing elastic fiber were found in MVAD rats. However, all of these were significantly improved in VAS-treated animals. These data suggest that the rat lung is sensitive to MVAD during the developing stage. Early postnatal vitamin A supplementation can partially restore the normal lung structure.
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Affiliation(s)
- Hua Wei
- Children's Nutritional Research Center, Pediatric Research Institute, Children's Hospital of Chongqing Medical University, PR China.
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Klemm RDW, Labrique AB, Christian P, Rashid M, Shamim AA, Katz J, Sommer A, West KP. Newborn vitamin A supplementation reduced infant mortality in rural Bangladesh. Pediatrics 2008; 122:e242-50. [PMID: 18595969 DOI: 10.1542/peds.2007-3448] [Citation(s) in RCA: 114] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVES We assessed the effect of supplementing newborns with 50000 IU of vitamin A on all-cause infant mortality through 24 weeks of age. PATIENTS AND METHODS This was a community-based, double-masked, cluster-randomized, placebo-controlled trial conducted in 19 unions in rural northwest Bangladesh. The study was nested into and balanced across treatment arms of an ongoing placebo-controlled, weekly maternal vitamin A or beta-carotene supplementation trial. Study-defined sectors (N = 596) were evenly randomized for newborns of participating mothers to receive a single, oral supplement of vitamin A (50000 IU) or placebo as droplets of oil squeezed from a gelatinous capsule. Mothers provided informed consent for newborn participation at approximately 28 weeks' gestation. After birth, typically at home (where >90% of births occurred), infants were supplemented and their vital status was followed through 24 weeks of age. The main outcome measure was mortality through 24 weeks of age. RESULTS We obtained maternal consent to dose 17116 live-born infants (99.8% of all eligible) among whom 15937 (93.1%) were visited to be supplemented <30 days after birth and for whom vital status at 24 weeks of age was known. Dosed infants (n = 15902 [99.8%]) received their study supplement at a median age of 7 hours. Relative to control subjects, the risk of death in vitamin A-supplemented infants was 0.85, reflecting a 15% reduction in all-cause mortality. Protective relative risks were indistinguishable by infant gender, gestational age, birth weight, age at dosing, maternal age, parity, or across the 3 treatment arms of the maternal supplementation trial. CONCLUSIONS Newborn vitamin A dosing improved infant survival through the first 6 months of life in Bangladesh. These results corroborate previous findings from studies in Indonesia and India and provide additional evidence that vitamin A supplementation shortly after birth can reduce infant mortality in South Asia.
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Affiliation(s)
- Rolf D W Klemm
- DrPH, Johns Hopkins University, Center for Human Nutrition, Department of International Health, Bloomberg School of Public Health, 615 North Wolfe St, Baltimore, MD 21205.
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Boucherat O, Franco-Montoya ML, Thibault C, Incitti R, Chailley-Heu B, Delacourt C, Bourbon JR. Gene expression profiling in lung fibroblasts reveals new players in alveolarization. Physiol Genomics 2007; 32:128-41. [PMID: 17911382 DOI: 10.1152/physiolgenomics.00108.2007] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Little is known about the molecular basis of lung alveolarization. We used a microarray profiling strategy to identify novel genes that may regulate the secondary septation process. Rat lung fibroblasts were extemporaneously isolated on postnatal days 2, 7, and 21, i.e., before, during, and after septation, respectively. Total RNA was extracted, and cRNAs were hybridized to Affymetrix rat genome 230 2.0 microarrays. Expression levels of a selection of genes were confirmed by real-time PCR. In addition to genes already known to be upregulated during alveolarization including drebrin, midkine, Fgfr3, and Fgfr4, the study allowed us to identify two remarkable groups of genes with opposite profiles, i.e., gathering genes either transiently up- or downregulated on day 7. The former group includes the transcription factors retinoic acid receptor (RXR)-gamma and homeobox (Hox) a2, a4, and a5 and genes involved in Wnt signaling (Wnt5a, Fzd1, and Ndp); the latter group includes the extracellular matrix components Comp and Opn and the signal molecule Slfn4. Profiling in whole lung from fetal life to adulthood confirmed that changes were specific for alveolarization. Two treatments that arrest septation, hyperoxia and dexamethasone, inhibited the expression of genes that are upregulated during alveolarization and conversely enhanced that of genes weakly expressed during alveolarization and upregulated thereafter. The possible roles of these genes in secondary septation are discussed. Gene expression profiling analysis on freshly isolated cells represents a powerful approach to provide new information about differential regulation of genes during alveolarization and pathways potentially involved in the pathogenesis of bronchopulmonary dysplasia.
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Affiliation(s)
- Olivier Boucherat
- Institut National de la Santé et de la Recherche Médicale (INSERM), Unité 841, Institut Mondor de Recherche Biomédicale (IMRB), Département de Biologie et Thérapeutiques Cardiorespiratoires et Hépatiques, Créteil, France
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Bourbon J, Boucherat O, Chailley-Heu B, Delacourt C. Control mechanisms of lung alveolar development and their disorders in bronchopulmonary dysplasia. Pediatr Res 2005; 57:38R-46R. [PMID: 15817499 DOI: 10.1203/01.pdr.0000159630.35883.be] [Citation(s) in RCA: 154] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Bronchopulmonary dysplasia (BPD) is a chronic lung disease that occurs in very premature infants and is characterized by impaired alveologenesis. This ultimate phase of lung development is mostly postnatal and allows growth of gas-exchange surface area to meet the needs of the organism. Alveologenesis is a highly integrated process that implies cooperative interactions between interstitial, epithelial, and vascular compartments of the lung. Understanding of its underlying mechanisms has considerably progressed recently with identification of structural, signaling, or remodeling molecules that are crucial in the process. Thus, the pivotal role of elastin deposition in lung walls has been demonstrated, and many key control-molecules have been identified, including various transcription factors, growth factors such as platelet-derived growth factor, fibroblast growth factors, and vascular endothelial growth factor, matrix-remodeling enzymes, and retinoids. BPD-associated changes in lung expression/content have been evidenced for most of these molecules, especially for signaling pathways, through both clinical investigations in premature infants and the use of animal models, including the premature baboon or lamb, neonatal exposure to hyperoxia in rodents, and maternal-fetal infection. These findings open therapeutic perspectives to correct imbalanced signaling. Unraveling the intimate molecular mechanisms of alveolar building appears as a prerequisite to define new strategies for the prevention and care of BPD.
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Affiliation(s)
- Jacques Bourbon
- Inserm U651-Université Paris XII, Faculté de Médecine, Créteil, France.
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