1
|
Goldschagg MGE, Hockman D. FGF18. Differentiation 2024; 139:100735. [PMID: 38007374 DOI: 10.1016/j.diff.2023.10.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 09/25/2023] [Accepted: 10/25/2023] [Indexed: 11/27/2023]
Abstract
FGF18 was discovered in 1998. It is a pleiotropic growth factor that stimulates major signalling pathways involved in cell proliferation and growth, and is involved in the development and homeostasis of many tissues such as bone, lung, and central nervous system. The gene consists of five exons that code for a 207 amino acid glycosylated protein. FGF18 is widely expressed in developing and adult chickens, mice, and humans, being seen in the mesenchyme, brain, skeleton, heart, and lungs. Knockout studies of FGF18 in mice lead to perinatal death, characterised by distinct phenotypes such as cleft palate, smaller body size, curved long bones, deformed ribs, and reduced crania. As can be expected from a protein involved in so many functions FGF18 is associated with various diseases such as idiopathic pulmonary fibrosis, congenital diaphragmatic hernia, and most notably various types of cancer such as breast, lung, and ovarian cancer.
Collapse
Affiliation(s)
- Michael G E Goldschagg
- Division of Cell Biology, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Dorit Hockman
- Division of Cell Biology, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa; Neuroscience Institute, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.
| |
Collapse
|
2
|
Yin Y, Koenitzer JR, Patra D, Dietmann S, Bayguinov P, Hagan AS, Ornitz DM. Identification of a myofibroblast differentiation program during neonatal lung development. Development 2024; 151:dev202659. [PMID: 38602479 PMCID: PMC11165721 DOI: 10.1242/dev.202659] [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: 12/26/2023] [Accepted: 03/25/2024] [Indexed: 04/12/2024]
Abstract
Alveologenesis is the final stage of lung development in which the internal surface area of the lung is increased to facilitate efficient gas exchange in the mature organism. The first phase of alveologenesis involves the formation of septal ridges (secondary septae) and the second phase involves thinning of the alveolar septa. Within secondary septa, mesenchymal cells include a transient population of alveolar myofibroblasts (MyoFBs) and a stable but poorly described population of lipid-rich cells that have been referred to as lipofibroblasts or matrix fibroblasts (MatFBs). Using a unique Fgf18CreER lineage trace mouse line, cell sorting, single-cell RNA sequencing and primary cell culture, we have identified multiple subtypes of mesenchymal cells in the neonatal lung, including an immature progenitor cell that gives rise to mature MyoFB. We also show that the endogenous and targeted ROSA26 locus serves as a sensitive reporter for MyoFB maturation. These studies identify a MyoFB differentiation program that is distinct from other mesenchymal cell types and increases the known repertoire of mesenchymal cell types in the neonatal lung.
Collapse
Affiliation(s)
- Yongjun Yin
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Jeffrey R. Koenitzer
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Debabrata Patra
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Sabine Dietmann
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA
- Institute for Informatics, Data Science and Biostatistics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Peter Bayguinov
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Andrew S. Hagan
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - David M. Ornitz
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA
| |
Collapse
|
3
|
Nishihara S, Ohira T. The mechanism of pattern transitions between formation and dispersion. J Theor Biol 2024; 581:111736. [PMID: 38246485 DOI: 10.1016/j.jtbi.2024.111736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Revised: 11/10/2023] [Accepted: 01/11/2024] [Indexed: 01/23/2024]
Abstract
On the surface of living organisms, a wide variety of patterns can be observed, some of which change during their growth process. For instance, Pelodiscus sinensis exhibits distinct black patterns on its vivid orange plastron during the embryonic and juvenile stages, but as it matures, the black patterns gradually disappear, resulting in a whitened plastron. This pattern transition is a mysterious phenomenon that forms and vanishes on the plastron, a ventral part with low visibility to both predators and peers. Our research aims to focus on understanding the mechanisms behind such pattern transitions and proposes a model capable of representing pattern formation and dispersion. To understand the changing patterns, we propose a hypothesis based on a reaction-diffusion system with a time-dependent growing spatial domain. This mathematical framework suggests the occurrence of the dispersion phenomenon. Specifically, we focus on the dilution term within the system under the growing-domain condition. While previous studies have investigated the effects of growth domains, this study specifically addresses the role of the time-dependently growing domain effects - change of diffusion coefficient and dilution - in reaction-diffusion systems. Our research sheds light on the intricate phenomenon of pattern formation and dispersion on the surface of living organisms, proposing a natural system based on the effects of growing domain, namely, a model of reaction-dilution-diffusion systems.
Collapse
Affiliation(s)
- Shin Nishihara
- Graduate School of Mathematics, Nagoya University, Furocho, Chikusaku, Nagoya 464-8602, Japan
| | - Toru Ohira
- Graduate School of Mathematics, Nagoya University, Furocho, Chikusaku, Nagoya 464-8602, Japan.
| |
Collapse
|
4
|
Yin Y, Koenitzer JR, Patra D, Dietmann S, Bayguinov P, Hagan AS, Ornitz DM. Identification of a myofibroblast differentiation program during neonatal lung development. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.28.573370. [PMID: 38234814 PMCID: PMC10793446 DOI: 10.1101/2023.12.28.573370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
Alveologenesis is the final stage of lung development in which the internal surface area of the lung is increased to facilitate efficient gas exchange in the mature organism. The first phase of alveologenesis involves the formation of septal ridges (secondary septae) and the second phase involves thinning of the alveolar septa. Within secondary septa, mesenchymal cells include a transient population of alveolar myofibroblasts (MyoFB) and a stable but poorly described population of lipid rich cells that have been referred to as lipofibroblasts or matrix fibroblasts (MatFB). Using a unique Fgf18CreER lineage trace mouse line, cell sorting, single cell RNA sequencing, and primary cell culture, we have identified multiple subtypes of mesenchymal cells in the neonatal lung, including an immature progenitor cell that gives rise to mature MyoFB. We also show that the endogenous and targeted ROSA26 locus serves as a sensitive reporter for MyoFB maturation. These studies identify a myofibroblast differentiation program that is distinct form other mesenchymal cells types and increases the known repertoire of mesenchymal cell types in the neonatal lung.
Collapse
Affiliation(s)
- Yongjun Yin
- Departments of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110
| | | | - Debabrata Patra
- Departments of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110
| | - Sabine Dietmann
- Departments of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110
- Institute for Informatics, Data Science & Biostatistics, Washington University School of Medicine, St. Louis, MO 63110
| | - Peter Bayguinov
- Neuroscience, Washington University School of Medicine, St. Louis, MO 63110
| | - Andrew S. Hagan
- Departments of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110
| | - David M. Ornitz
- Departments of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110
| |
Collapse
|
5
|
Danopoulos S, Belgacemi R, Hein RFC, Miller AJ, Deutsch GH, Glass I, Spence JR, Al Alam D. FGF18 promotes human lung branching morphogenesis through regulating mesenchymal progenitor cells. Am J Physiol Lung Cell Mol Physiol 2023; 324:L433-L444. [PMID: 36791060 PMCID: PMC10027085 DOI: 10.1152/ajplung.00316.2022] [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: 09/23/2022] [Revised: 01/26/2023] [Accepted: 01/27/2023] [Indexed: 02/16/2023] Open
Abstract
Fibroblast growth factor (FGF) signaling is known to play an important role in lung organogenesis. However, we recently demonstrated that FGF10 fails to induce branching in human fetal lungs as is observed in mouse. Our previous human fetal lung RNA sequencing data exhibited increased FGF18 during the pseudoglandular stage of development, suggestive of its importance in human lung branching morphogenesis. Whereas it has been previously reported that FGF18 is critical during alveologenesis, few studies have described its implication in lung branching, specifically in human. Therefore, we aimed to determine the role of FGF18 in human lung branching morphogenesis. Human fetal lung explants within the pseudoglandular stage of development were treated with recombinant human FGF18 in air-liquid interface culture. Explants were analyzed grossly to assess differences in branching pattern, as well as at the cellular and molecular levels. FGF18 treatment promoted branching in explant cultures and demonstrated increased epithelial proliferation as well as maintenance of the double positive SOX2/SOX9 distal bud progenitor cells, confirming its role in human lung branching morphogenesis. In addition, FGF18 treated explants displayed increased expression of SOX9, FN1, and COL2A1 within the mesenchyme, all factors that are important to chondrocyte differentiation. In humans, cartilaginous airways extend deep into the lung up to the 12th generation of branching whereas in mouse these are restricted to the trachea and main bronchi. Therefore, our data suggest that FGF18 promotes human lung branching morphogenesis through regulating mesenchymal progenitor cells.
Collapse
Affiliation(s)
- Soula Danopoulos
- Lundquist Institute for Biomedical Innovation, Harbor-UCLA Medical Center, Torrance, California, United States
- Division of Neonatology, Department of Pediatrics, David Geffen School of Medicine at University of California, Los Angeles, California, United States
| | - Randa Belgacemi
- Lundquist Institute for Biomedical Innovation, Harbor-UCLA Medical Center, Torrance, California, United States
| | - Renee F C Hein
- Department of Cell and Developmental biology, University of Michigan Medical School, Ann Arbor, Michigan, United States
| | - Alyssa J Miller
- Department of Cell and Developmental biology, University of Michigan Medical School, Ann Arbor, Michigan, United States
| | - Gail H Deutsch
- Department of Laboratory Medicine and Pathology, University of Washington School of Medicine and Seattle Children's Research Institute, Seattle, Washington, United States
| | - Ian Glass
- Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington, United States
| | - Jason R Spence
- Department of Cell and Developmental biology, University of Michigan Medical School, Ann Arbor, Michigan, United States
- Department of Internal Medicine, Gastroenterology, University of Michigan Medical School, Ann Arbor, Michigan, United States
| | - Denise Al Alam
- Lundquist Institute for Biomedical Innovation, Harbor-UCLA Medical Center, Torrance, California, United States
- Division of Neonatology, Department of Pediatrics, David Geffen School of Medicine at University of California, Los Angeles, California, United States
| |
Collapse
|
6
|
Suzuki Y, Oinaka H, Nakajima H, Nampei M, Kawakita F, Miura Y, Yasuda R, Toma N, Suzuki H. Plasma Fibulin-5 Levels as an Independent Predictor of a Poor Outcome after an Aneurysmal Subarachnoid Hemorrhage. Int J Mol Sci 2022; 23:ijms232315184. [PMID: 36499510 PMCID: PMC9740042 DOI: 10.3390/ijms232315184] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 11/27/2022] [Accepted: 12/01/2022] [Indexed: 12/09/2022] Open
Abstract
Aneurysmal subarachnoid hemorrhage (SAH) is a poor-outcome disease with a delayed neurological exacerbation. Fibulin-5 (FBLN5) is one of matricellular proteins, some of which have been involved in SAH pathologies. However, no study has investigated FBLN5's roles in SAH. This study was aimed at examining the relationships between serially measured plasma FBLN5 levels and neurovascular events or outcomes in 204 consecutive aneurysmal SAH patients, including 77 patients (37.7%) with poor outcomes (90-day modified Rankin Scale 3-6). Plasma FBLN5 levels were not related to angiographic vasospasm, delayed cerebral ischemia, and delayed cerebral infarction, but elevated levels were associated with severe admission clinical grades, any neurological exacerbation and poor outcomes. Receiver-operating characteristic curves indicated that the most reasonable cut-off values of plasma FBLN5, in order to differentiate 90-day poor from good outcomes, were obtained from analyses at days 4-6 for all patients (487.2 ng/mL; specificity, 61.4%; and sensitivity, 62.3%) and from analyses at days 7-9 for only non-severe patient (476.8 ng/mL; specificity, 66.0%; and sensitivity, 77.8%). Multivariate analyses revealed that the plasma FBLN5 levels were independent determinants of the 90-day poor outcomes in both all patients' and non-severe patients' analyses. These findings suggest that the delayed elevation of plasma FBLN5 is related to poor outcomes, and that FBLN5 may be a new molecular target to reveal a post-SAH pathophysiology.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | - Hidenori Suzuki
- Correspondence: ; Tel.: +81-59-232-1111; Fax: +81-59-231-5212
| | | |
Collapse
|
7
|
The synergistic mechanism of fibroblast growth factor 18 and integrin β1 in rat abdominal aortic aneurysm repair. BMC Cardiovasc Disord 2022; 22:415. [PMID: 36115958 PMCID: PMC9482292 DOI: 10.1186/s12872-022-02851-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 09/07/2022] [Indexed: 11/30/2022] Open
Abstract
Background Abdominal aortic aneurysms have a high mortality rate. While surgery is the preferred treatment method, the biological repair of abdominal aortic aneurysms is being increasingly studied. We performed cellular and animal experiments to investigate the simultaneous function and mechanism of fibroblast growth factor 18 and integrin β1 in the biological repair of abdominal aortic aneurysms. Methods Endothelial and smooth muscle cells of rat arteries were used for the cellular experiments. Intracellular integrin β1 expression was regulated through lentiviral transfection. Interventions with fibroblast growth factor 18 were determined according to the experimental protocol. Several methods were used to detect the expression of elastic fiber component proteins, cell proliferation, and migratory activity of endothelial and smooth muscle cells after different treatments. For animal experiments, abdominal aortic aneurysms were induced in rats by wrapping the abdominal aortae in sterile cotton balls soaked with CaCl2 solution. Fibroblast growth factor 18 was administered through tail vein injections. The local expression of integrin β1 was regulated through lentiviral injections into the adventitia of the abdominal aortic aneurysms. The abdominal aortae were harvested for pathological examinations and tensile mechanical tests. Results The expression of integrin β1 in endothelial and smooth muscle cells could be regulated effectively through lentiviral transfection. Animal and cellular experiments showed that fibroblast growth factor 18 + integrin β1 could improve the expression of elastic fiber component proteins and enhance the migratory and proliferative activities of smooth muscle and endothelial cells. Moreover, animal experiments showed that fibroblast growth factor 18 + integrin β1 could enhance the aortic integrity to withstand stretch of aortic aneurysm tissue. Conclusion Fibroblast growth factor 18 + integrin β1 improved the biological repair of abdominal aortic aneurysms in rats by increasing the expression of elastic proteins, improving the migratory and proliferative abilities of endothelial and smooth muscle cells, and improving aortic remodeling. Supplementary Information The online version contains supplementary material available at 10.1186/s12872-022-02851-y.
Collapse
|
8
|
Ornitz DM, Itoh N. New developments in the biology of fibroblast growth factors. WIREs Mech Dis 2022; 14:e1549. [PMID: 35142107 PMCID: PMC10115509 DOI: 10.1002/wsbm.1549] [Citation(s) in RCA: 41] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 11/08/2021] [Accepted: 11/09/2021] [Indexed: 01/28/2023]
Abstract
The fibroblast growth factor (FGF) family is composed of 18 secreted signaling proteins consisting of canonical FGFs and endocrine FGFs that activate four receptor tyrosine kinases (FGFRs 1-4) and four intracellular proteins (intracellular FGFs or iFGFs) that primarily function to regulate the activity of voltage-gated sodium channels and other molecules. The canonical FGFs, endocrine FGFs, and iFGFs have been reviewed extensively by us and others. In this review, we briefly summarize past reviews and then focus on new developments in the FGF field since our last review in 2015. Some of the highlights in the past 6 years include the use of optogenetic tools, viral vectors, and inducible transgenes to experimentally modulate FGF signaling, the clinical use of small molecule FGFR inhibitors, an expanded understanding of endocrine FGF signaling, functions for FGF signaling in stem cell pluripotency and differentiation, roles for FGF signaling in tissue homeostasis and regeneration, a continuing elaboration of mechanisms of FGF signaling in development, and an expanding appreciation of roles for FGF signaling in neuropsychiatric diseases. This article is categorized under: Cardiovascular Diseases > Molecular and Cellular Physiology Neurological Diseases > Molecular and Cellular Physiology Congenital Diseases > Stem Cells and Development Cancer > Stem Cells and Development.
Collapse
Affiliation(s)
- David M Ornitz
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Nobuyuki Itoh
- Kyoto University Graduate School of Pharmaceutical Sciences, Sakyo, Kyoto, Japan
| |
Collapse
|
9
|
Rippa AL, Alpeeva EV, Vasiliev AV, Vorotelyak EA. Alveologenesis: What Governs Secondary Septa Formation. Int J Mol Sci 2021; 22:ijms222212107. [PMID: 34829987 PMCID: PMC8618598 DOI: 10.3390/ijms222212107] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 11/02/2021] [Accepted: 11/03/2021] [Indexed: 12/30/2022] Open
Abstract
The simplification of alveoli leads to various lung pathologies such as bronchopulmonary dysplasia and emphysema. Deep insight into the process of emergence of the secondary septa during development and regeneration after pneumonectomy, and into the contribution of the drivers of alveologenesis and neo-alveolarization is required in an efficient search for therapeutic approaches. In this review, we describe the formation of the gas exchange units of the lung as a multifactorial process, which includes changes in the actomyosin cytoskeleton of alveocytes and myofibroblasts, elastogenesis, retinoic acid signaling, and the contribution of alveolar mesenchymal cells in secondary septation. Knowledge of the mechanistic context of alveologenesis remains incomplete. The characterization of the mechanisms that govern the emergence and depletion of αSMA will allow for an understanding of how the niche of fibroblasts is changing. Taking into account the intense studies that have been performed on the pool of lung mesenchymal cells, we present data on the typing of interstitial fibroblasts and their role in the formation and maintenance of alveoli. On the whole, when identifying cell subpopulations in lung mesenchyme, one has to consider the developmental context, the changing cellular functions, and the lability of gene signatures.
Collapse
|
10
|
Riccetti M, Gokey JJ, Aronow B, Perl AKT. The elephant in the lung: Integrating lineage-tracing, molecular markers, and single cell sequencing data to identify distinct fibroblast populations during lung development and regeneration. Matrix Biol 2020; 91-92:51-74. [PMID: 32442602 PMCID: PMC7434667 DOI: 10.1016/j.matbio.2020.05.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 05/08/2020] [Accepted: 05/08/2020] [Indexed: 12/26/2022]
Abstract
During lung development, the mesenchyme and epithelium are dependent on each other for instructive morphogenic cues that direct proliferation, cellular differentiation and organogenesis. Specification of epithelial and mesenchymal cell lineages occurs in parallel, forming cellular subtypes that guide the formation of both transitional developmental structures and the permanent architecture of the adult lung. While epithelial cell types and lineages have been relatively well-defined in recent years, the definition of mesenchymal cell types and lineage relationships has been more challenging. Transgenic mouse lines with permanent and inducible lineage tracers have been instrumental in identifying lineage relationships among epithelial progenitor cells and their differentiation into distinct airway and alveolar epithelial cells. Lineage tracing experiments with reporter mice used to identify fibroblast progenitors and their lineage trajectories have been limited by the number of cell specific genes and the developmental timepoint when the lineage trace was activated. In this review, we discuss major developmental mesenchymal lineages, focusing on time of origin, major cell type, and other lineage derivatives, as well as the transgenic tools used to find and define them. We describe lung fibroblasts using function, location, and molecular markers in order to compare and contrast cells with similar functions. The temporal and cell-type specific expression of fourteen "fibroblast lineage" genes were identified in single-cell RNA-sequencing data from LungMAP in the LGEA database. Using these lineage signature genes as guides, we clustered murine lung fibroblast populations from embryonic day 16.5 to postnatal day 28 (E16.5-PN28) and generated heatmaps to illustrate expression of transcription factors, signaling receptors and ligands in a temporal and population specific manner.
Collapse
Affiliation(s)
- Matthew Riccetti
- The Perinatal Institute and Section of Neonatology, Perinatal and Pulmonary Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States; Molecular and Developmental Biology Graduate Program, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States
| | - Jason J Gokey
- The Perinatal Institute and Section of Neonatology, Perinatal and Pulmonary Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States
| | - Bruce Aronow
- Department of Biomedical Informatics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States; Department of Pediatrics, University of Cincinnati School of Medicine, Cincinnati, OH, United States
| | - Anne-Karina T Perl
- The Perinatal Institute and Section of Neonatology, Perinatal and Pulmonary Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States; Molecular and Developmental Biology Graduate Program, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States; Department of Pediatrics, University of Cincinnati School of Medicine, Cincinnati, OH, United States.
| |
Collapse
|
11
|
Kinnear C, Agrawal R, Loo C, Pahnke A, Rodrigues DC, Thompson T, Akinrinade O, Ahadian S, Keeley F, Radisic M, Mital S, Ellis J. Everolimus Rescues the Phenotype of Elastin Insufficiency in Patient Induced Pluripotent Stem Cell-Derived Vascular Smooth Muscle Cells. Arterioscler Thromb Vasc Biol 2020; 40:1325-1339. [PMID: 32212852 PMCID: PMC7176340 DOI: 10.1161/atvbaha.119.313936] [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] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Supplemental Digital Content is available in the text. Objective: Elastin gene deletion or mutation leads to arterial stenoses due to vascular smooth muscle cell (SMC) proliferation. Human induced pluripotent stem cells–derived SMCs can model the elastin insufficiency phenotype in vitro but show only partial rescue with rapamycin. Our objective was to identify drug candidates with superior efficacy in rescuing the SMC phenotype in elastin insufficiency patients. Approach and Results: SMCs generated from induced pluripotent stem cells from 5 elastin insufficiency patients with severe recurrent vascular stenoses (3 Williams syndrome and 2 elastin mutations) were phenotypically immature, hyperproliferative, poorly responsive to endothelin, and exerted reduced tension in 3-dimensional smooth muscle biowires. Elastin mRNA and protein were reduced in SMCs from patients compared to healthy control SMCs. Fourteen drug candidates were tested on patient SMCs. Of the mammalian target of rapamycin inhibitors studied, everolimus restored differentiation, rescued proliferation, and improved endothelin-induced calcium flux in all patient SMCs except one Williams syndrome. Of the calcium channel blockers, verapamil increased SMC differentiation and reduced proliferation in Williams syndrome patient cells but not in elastin mutation patients and had no effect on endothelin response. Combination treatment with everolimus and verapamil was not superior to everolimus alone. Other drug candidates had limited efficacy. Conclusions: Everolimus caused the most consistent improvement in SMC differentiation, proliferation and in SMC function in patients with both syndromic and nonsyndromic elastin insufficiency, and offers the best candidate for drug repurposing for treatment of elastin insufficiency associated vasculopathy.
Collapse
Affiliation(s)
- Caroline Kinnear
- From the Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada (C.K., R.A., O.A., S.M.)
| | - Rahul Agrawal
- From the Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada (C.K., R.A., O.A., S.M.)
| | - Caitlin Loo
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, Ontario, Canada (C.L., D.C.R., T.T., J.E.).,Department of Molecular Genetics (C.L., J.E.), University of Toronto, Ontario, Canada
| | - Aric Pahnke
- Institute of Biomaterials and Biomedical Engineering (A.P., S.A., M.R.), University of Toronto, Ontario, Canada.,Department of Chemical Engineering and Applied Chemistry (A.P., S.A., M.R.), University of Toronto, Ontario, Canada
| | - Deivid Carvalho Rodrigues
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, Ontario, Canada (C.L., D.C.R., T.T., J.E.)
| | - Tadeo Thompson
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, Ontario, Canada (C.L., D.C.R., T.T., J.E.)
| | - Oyediran Akinrinade
- From the Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada (C.K., R.A., O.A., S.M.)
| | - Samad Ahadian
- Institute of Biomaterials and Biomedical Engineering (A.P., S.A., M.R.), University of Toronto, Ontario, Canada.,Department of Chemical Engineering and Applied Chemistry (A.P., S.A., M.R.), University of Toronto, Ontario, Canada
| | - Fred Keeley
- Department of Biochemistry (F.K.), University of Toronto, Ontario, Canada.,Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada (F.K.)
| | - Milica Radisic
- Institute of Biomaterials and Biomedical Engineering (A.P., S.A., M.R.), University of Toronto, Ontario, Canada.,Department of Chemical Engineering and Applied Chemistry (A.P., S.A., M.R.), University of Toronto, Ontario, Canada
| | - Seema Mital
- From the Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada (C.K., R.A., O.A., S.M.).,Department of Pediatrics, The Hospital for Sick Children (S.M.), University of Toronto, Ontario, Canada
| | - James Ellis
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, Ontario, Canada (C.L., D.C.R., T.T., J.E.).,Department of Molecular Genetics (C.L., J.E.), University of Toronto, Ontario, Canada
| |
Collapse
|
12
|
Hagan AS, Zhang B, Ornitz DM. Identification of a FGF18-expressing alveolar myofibroblast that is developmentally cleared during alveologenesis. Development 2020; 147:dev.181032. [PMID: 31862844 DOI: 10.1242/dev.181032] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 12/12/2019] [Indexed: 12/13/2022]
Abstract
Alveologenesis is an essential developmental process that increases the surface area of the lung through the formation of septal ridges. In the mouse, septation occurs postnatally and is thought to require the alveolar myofibroblast (AMF). Though abundant during alveologenesis, markers for AMFs are minimally detected in the adult. After septation, the alveolar walls thin to allow efficient gas exchange. Both loss of AMFs or retention and differentiation into another cell type during septal thinning have been proposed. Using a novel Fgf18:CreERT2 allele to lineage trace AMFs, we demonstrate that most AMFs are developmentally cleared during alveologenesis. Lung mesenchyme also contains other poorly described cell types, including alveolar lipofibroblasts (ALF). We show that Gli1:CreERT2 marks both AMFs as well as ALFs, and lineage tracing shows that ALFs are retained in adult alveoli while AMFs are lost. We further show that multiple immune cell populations contain lineage-labeled particles, suggesting a phagocytic role in the clearance of AMFs. The demonstration that the AMF lineage is depleted during septal thinning through a phagocytic process provides a mechanism for the clearance of a transient developmental cell population.
Collapse
Affiliation(s)
- Andrew S Hagan
- Department of Developmental Biology, Washington University School of Medicine, St Louis, MO 63110, USA
| | - Bo Zhang
- Department of Developmental Biology, Washington University School of Medicine, St Louis, MO 63110, USA
| | - David M Ornitz
- Department of Developmental Biology, Washington University School of Medicine, St Louis, MO 63110, USA
| |
Collapse
|
13
|
Hagan AS, Boylan M, Smith C, Perez-Santamarina E, Kowalska K, Hung IH, Lewis RM, Hajihosseini MK, Lewandoski M, Ornitz DM. Generation and validation of novel conditional flox and inducible Cre alleles targeting fibroblast growth factor 18 (Fgf18). Dev Dyn 2019; 248:882-893. [PMID: 31290205 PMCID: PMC7029619 DOI: 10.1002/dvdy.85] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 06/24/2019] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Fibroblast growth factor 18 (FGF18) functions in the development of several tissues, including the lung, limb bud, palate, skeleton, central nervous system, and hair follicle. Mice containing a germline knockout of Fgf18 (Fgf18 -/- ) die shortly after birth. Postnatally, FGF18 is being evaluated for pathogenic roles in fibrosis and several types of cancer. The specific cell types that express FGF18 have been difficult to identify, and the function of FGF18 in postnatal development and tissue homeostasis has been hampered by the perinatal lethality of Fgf18 null mice. RESULTS We engineered a floxed allele of Fgf18 (Fgf18 flox ) that allows conditional gene inactivation and a CreERT2 knockin allele (Fgf18 CreERT2 ) that allows the precise identification of cells that express Fgf18 and their lineage. We validated the Fgf18 flox allele by targeting it in mesenchymal tissue and primary mesoderm during embryonic development, resulting in similar phenotypes to those observed in Fgf18 null mice. We also use the Fgf18 CreERT2 allele, in combination with a conditional fluorescent reporter to confirm known and identify new sites of Fgf18 expression. CONCLUSION These alleles will be useful to investigate FGF18 function during organogenesis and tissue homeostasis, and to target specific cell lineages at embryonic and postnatal time points.
Collapse
Affiliation(s)
- Andrew S. Hagan
- Department of Developmental Biology, Washington University School of Medicine, Saint Louis, Missouri
| | - Michael Boylan
- Cancer and Developmental Biology Lab, National Cancer Institute, National Institutes of Health, Frederick, Maryland
| | - Craig Smith
- Department of Developmental Biology, Washington University School of Medicine, Saint Louis, Missouri
| | | | - Karolina Kowalska
- School of Biological Sciences, University of East Anglia, Norwich, UK
| | - Irene H. Hung
- Department of Neurobiology & Anatomy, University of Utah School of Medicine, Salt Lake City, Utah
| | - Renate M. Lewis
- Department of Neurology, Washington University School of Medicine, Saint Louis, Missouri
| | | | - Mark Lewandoski
- Cancer and Developmental Biology Lab, National Cancer Institute, National Institutes of Health, Frederick, Maryland
| | - David M. Ornitz
- Department of Developmental Biology, Washington University School of Medicine, Saint Louis, Missouri
| |
Collapse
|
14
|
Assessment of the nitrofen model of congenital diaphragmatic hernia and of the dysregulated factors involved in pulmonary hypoplasia. Pediatr Surg Int 2019; 35:41-61. [PMID: 30386897 DOI: 10.1007/s00383-018-4375-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/18/2018] [Indexed: 02/08/2023]
Abstract
PURPOSE To study pulmonary hypoplasia (PH) associated with congenital diaphragmatic hernia (CDH), investigators have been employing a fetal rat model based on nitrofen administration to dams. Herein, we aimed to: (1) investigate the validity of the model, and (2) synthesize the main biological pathways implicated in the development of PH associated with CDH. METHODS Using a defined strategy, we conducted a systematic review of the literature searching for studies reporting the incidence of CDH or factors involved in PH development. We also searched for PH factor interactions, relevance to lung development and to human PH. RESULTS Of 335 full-text articles, 116 reported the incidence of CDH after nitrofen exposure or dysregulated factors in the lungs of nitrofen-exposed rat fetuses. CDH incidence: 54% (27-85%) fetuses developed a diaphragmatic defect, whereas the whole litter had PH in varying degrees. Downregulated signaling pathways included FGF/FGFR, BMP/BMPR, Sonic Hedgehog and retinoid acid signaling pathway, resulting in a delay in early epithelial differentiation, immature distal epithelium and dysfunctional mesenchyme. CONCLUSIONS The nitrofen model effectively reproduces PH as it disrupts pathways that are critical for lung branching morphogenesis and alveolar differentiation. The low CDH rate confirms that PH is an associated phenomenon rather than the result of mechanical compression alone.
Collapse
|
15
|
Hsia CCW. Comparative analysis of the mechanical signals in lung development and compensatory growth. Cell Tissue Res 2017; 367:687-705. [PMID: 28084523 PMCID: PMC5321790 DOI: 10.1007/s00441-016-2558-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Accepted: 12/13/2016] [Indexed: 12/16/2022]
Abstract
This review compares the manner in which physical stress imposed on the parenchyma, vasculature and thorax and the thoraco-pulmonary interactions, drive both developmental and compensatory lung growth. Re-initiation of anatomical lung growth in the mature lung is possible when the loss of functioning lung units renders the existing physiologic-structural reserves insufficient for maintaining adequate function and physical stress on the remaining units exceeds a critical threshold. The appropriate spatial and temporal mechanical interrelationships and the availability of intra-thoracic space, are crucial to growth initiation, follow-on remodeling and physiological outcome. While the endogenous potential for compensatory lung growth is retained and may be pharmacologically augmented, supra-optimal mechanical stimulation, unbalanced structural growth, or inadequate remodeling may limit functional gain. Finding ways to optimize the signal-response relationships and resolve structure-function discrepancies are major challenges that must be overcome before the innate compensatory ability could be fully realized. Partial pneumonectomy reproducibly removes a known fraction of functioning lung units and remains the most robust model for examining the adaptive mechanisms, structure-function consequences and plasticity of the remaining functioning lung units capable of regeneration. Fundamental mechanical stimulus-response relationships established in the pneumonectomy model directly inform the exploration of effective approaches to maximize compensatory growth and function in chronic destructive lung diseases, transplantation and bioengineered lungs.
Collapse
Affiliation(s)
- Connie C W Hsia
- Department of Internal Medicine, Pulmonary and Critical Care Medicine, University of Texas Southwestern Medical Center, Dallas, 5323 Harry Hines Blvd., Dallas, TX, 75390-9034, USA.
| |
Collapse
|
16
|
Yun EJ, Lorizio W, Seedorf G, Abman SH, Vu TH. VEGF and endothelium-derived retinoic acid regulate lung vascular and alveolar development. Am J Physiol Lung Cell Mol Physiol 2015; 310:L287-98. [PMID: 26566904 DOI: 10.1152/ajplung.00229.2015] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 11/04/2015] [Indexed: 12/24/2022] Open
Abstract
Prevention or treatment of lung diseases caused by the failure to form, or destruction of, existing alveoli, as observed in infants with bronchopulmonary dysplasia and adults with emphysema, requires understanding of the molecular mechanisms of alveolar development. In addition to its critical role in gas exchange, the pulmonary circulation also contributes to alveolar morphogenesis and maintenance by the production of paracrine factors, termed "angiocrines," that impact the development of surrounding tissue. To identify lung angiocrines that contribute to alveolar formation, we disrupted pulmonary vascular development by conditional inactivation of the Vegf-A gene during alveologenesis. This resulted in decreased pulmonary capillary and alveolar development and altered lung elastin and retinoic acid (RA) expression. We determined that RA is produced by pulmonary endothelial cells and regulates pulmonary angiogenesis and elastin synthesis by induction of VEGF-A and fibroblast growth factor (FGF)-18, respectively. Inhibition of RA synthesis in newborn mice decreased FGF-18 and elastin expression and impaired alveolarization. Treatment with RA and vitamin A partially reversed the impaired vascular and alveolar development induced by VEGF inhibition. Thus we identified RA as a lung angiocrine that regulates alveolarization through autocrine regulation of endothelial development and paracrine regulation of elastin synthesis via induction of FGF-18 in mesenchymal cells.
Collapse
Affiliation(s)
- Eun Jun Yun
- Department of Medicine, University of California, San Francisco, San Francisco, California; and
| | - Walter Lorizio
- Department of Medicine, University of California, San Francisco, San Francisco, California; and
| | - Gregory Seedorf
- Pediatric Heart Lung Center and Department of Pediatrics, University of Colorado Denver-Anschutz Medical Campus, Aurora, Colorado
| | - Steven H Abman
- Pediatric Heart Lung Center and Department of Pediatrics, University of Colorado Denver-Anschutz Medical Campus, Aurora, Colorado
| | - Thiennu H Vu
- Department of Medicine, University of California, San Francisco, San Francisco, California; and
| |
Collapse
|
17
|
Ruiz-Camp J, Morty RE. Divergent fibroblast growth factor signaling pathways in lung fibroblast subsets: where do we go from here? Am J Physiol Lung Cell Mol Physiol 2015; 309:L751-5. [PMID: 26342090 DOI: 10.1152/ajplung.00298.2015] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 08/31/2015] [Indexed: 01/18/2023] Open
Abstract
Lung fibroblasts play a key role in postnatal lung development, namely, the formation of the alveolar gas exchange units, through the process of secondary septation. Although evidence initially highlighted roles for fibroblasts in the production and remodeling of the lung extracellular matrix, more recent studies have described the presence of different fibroblast subsets in the developing lung. These subsets include myofibroblasts and lipofibroblasts and their precursors. These cells are believed to play different roles in alveologenesis and are localized to different regions of the developing septa. The precise roles played by these different fibroblast subsets remain unclear. Understanding the signaling pathways that control the discrete functions of these fibroblast subsets would help to clarify the roles and the regulation of lung fibroblasts during lung development. Here, we critically evaluate a recent report that described divergent fibroblast growth factor (FGF) signaling pathways in two different subsets of lung fibroblasts that express different levels of green fluorescent protein (GFP) driven by the platelet-derived growth factor receptor-α promoter. The GFP expression was used as a surrogate for lipofibroblasts (GFP(low)) and myofibroblasts (GFP(high)). It was suggested that Fgf10/Fgf1 and Fgf18/Fgfr3 autocrine pathways may be operative in GFP(low) and GFP(high) cells, respectively, and that these pathways might regulate the proliferation and migration of different fibroblast subsets during alveologenesis. These observations lay important groundwork for the further exploration of FGF function during normal lung development, as well as in aberrant lung development associated with bronchopulmonary dysplasia.
Collapse
Affiliation(s)
- Jordi Ruiz-Camp
- Department of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany; and Department of Internal Medicine (Pulmonology), University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Rory E Morty
- Department of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany; and Department of Internal Medicine (Pulmonology), University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), Giessen, Germany
| |
Collapse
|
18
|
McGowan SE, McCoy DM. Fibroblast growth factor signaling in myofibroblasts differs from lipofibroblasts during alveolar septation in mice. Am J Physiol Lung Cell Mol Physiol 2015; 309:L463-74. [PMID: 26138642 DOI: 10.1152/ajplung.00013.2015] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 06/26/2015] [Indexed: 02/06/2023] Open
Abstract
Pulmonary alveolar fibroblasts produce extracellular matrix in a temporally and spatially regulated pattern to yield a durable yet pliable gas-exchange surface. Proliferation ensures a sufficient complement of cells, but they must differentiate into functionally distinct subtypes: contractile myofibroblasts (MF), which generate elastin and regulate air-flow at the alveolar ducts, and, in mice and rats, lipofibroblasts (LF), which store neutral lipids. PDGF-A is required but acts in conjunction with other differentiation factors arising from adjacent epithelia or within fibroblasts. We hypothesized that FGF receptor (FGFR) expression and function vary for MF and LF and contributes to their divergent differentiation. Whereas approximately half of the FGFR3 was extracellular in MF, FGFR2 and FGFR4 were primarily intracellular. Intracellular FGFR3 localized to the multivesicular body, and its abundance may be modified by Sprouty and interaction with heat shock protein-90. FGF18 mRNA is more abundant in MF, whereas FGF10 mRNA predominated in LF, which also express FGFR1 IIIb, a receptor for FGF10. FGF18 diminished fibroblast proliferation and was chemotactic for cultured fibroblasts. Although PDGF receptor-α (PDGFR-α) primarily signals through phosphoinositide 3-kinase and Akt, p42/p44 MAP kinase (Erk1/2), a major signaling pathway for FGFRs, influenced the abundance of cell-surface PDGFR-α. Observing different FGFR and ligand profiles in MF and LF is consistent with their divergent differentiation although both subpopulations express PDGFR-α. These studies also emphasize the importance of particular cellular locations of FGFR3 and PDGFR-α, which may modify their effects during alveolar development or repair.
Collapse
Affiliation(s)
- Stephen E McGowan
- Department of Veterans Affairs Research Service and Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa
| | - Diann M McCoy
- Department of Veterans Affairs Research Service and Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa
| |
Collapse
|
19
|
Sustained activation of toll-like receptor 9 induces an invasive phenotype in lung fibroblasts: possible implications in idiopathic pulmonary fibrosis. THE AMERICAN JOURNAL OF PATHOLOGY 2015; 185:943-57. [PMID: 25660181 DOI: 10.1016/j.ajpath.2014.12.011] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Revised: 12/19/2014] [Accepted: 12/29/2014] [Indexed: 02/06/2023]
Abstract
Idiopathic pulmonary fibrosis (IPF) is characterized by excessive scarring of the lung parenchyma, resulting in a steady decline of lung function and ultimately respiratory failure. The disease course of IPF is extremely variable, with some patients exhibiting stability of symptoms for prolonged periods of time, whereas others exhibit rapid progression and loss of lung function. Viral infections have been implicated in IPF and linked to disease severity; however, whether they directly contribute to progression is unclear. We previously classified patients as rapid and slow progressors on the basis of clinical features and expression of the pathogen recognition receptor, Toll-like receptor 9 (TLR9). Activation of TLR9 in vivo exacerbated IPF in mice and induced differentiation of myofibroblasts in vitro, but the mechanism of TLR9 up-regulation and progression of fibrosis are unknown. Herein, we investigate whether transforming growth factor (TGF)-β, a pleiotropic cytokine central to IPF pathogenesis, regulates TLR9 in lung myofibroblasts. Results showed induction of TLR9 expression by TGF-β in lung myofibroblasts and a distinct profibrotic myofibroblast phenotype driven by stimulation with the TLR9 agonist, CpG-DNA. Chronic TLR9 stimulation resulted in stably differentiated α-smooth muscle actin(+)/platelet-derived growth factor receptor α(+)/CD44(+)/matrix metalloproteinase-14(+)/matrix metalloproteinase-2(+) myofibroblasts, which secrete inflammatory cytokines, invade Matrigel toward platelet-derived growth factor, and resist hypoxia-induced apoptosis. These results suggest a mechanism by which TGF-β and TLR9 responses in myofibroblasts collaborate to drive rapid progression of IPF.
Collapse
|
20
|
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.
Collapse
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
| | | | | |
Collapse
|
21
|
Pulmonary FGF-18 gene expression is downregulated during the canalicular-saccular stages in nitrofen-induced hypoplastic lungs. Pediatr Surg Int 2013; 29:1199-203. [PMID: 23979401 DOI: 10.1007/s00383-013-3387-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
PURPOSE Pulmonary hypoplasia (PH) associated with congenital diaphragmatic hernia (CDH) represents one of the major challenges in neonatal intensive care. However, the molecular pathogenesis of PH is still poorly understood. In developing fetal lungs, fibroblast growth factor 18 (FGF-18) plays a crucial role in distal airway maturation. FGF-18 knockouts show smaller lung sizes with reduced alveolar spaces and thicker interstitial mesenchymal compartments, highlighting its important function for fetal lung growth and differentiation. We hypothesized that pulmonary FGF-18 gene expression is downregulated during late gestation in nitrofen-induced hypoplastic lungs. METHODS Pregnant rats were exposed to either olive oil or nitrofen on day 9 of gestation (D9). Fetuses were harvested on D18 and D21, and lungs were divided into three groups: controls, hypoplastic lungs without CDH [CDH(-)], and hypoplastic lungs with CDH [CDH(+)] (n = 24 at each time-point). Pulmonary FGF-18 gene expression levels were analyzed by qRT-PCR. Immunohistochemistry was performed to investigate FGF-18 protein expression/distribution. RESULTS Relative mRNA levels of pulmonary FGF-18 gene expression were significantly decreased in CDH(-) and CDH(+) on D18 and D21 compared to controls (p < 0.05 and p < 0.01, respectively). Immunoreactivity of FGF-18 was markedly diminished in mesenchymal cells surrounding the airway epithelium on D18 and D21 compared to controls. CONCLUSION Downregulation of FGF-18 gene expression in nitrofen-induced hypoplastic lungs suggests that decreased FGF-18 expression during the canalicular-saccular stages may interfere with saccular-alveolar differentiation and distal airway maturation resulting in PH.
Collapse
|
22
|
Vuckovic A, Herber-Jonat S, Flemmer AW, Roubliova XI, Jani JC. Alveolarization genes modulated by fetal tracheal occlusion in the rabbit model for congenital diaphragmatic hernia: a randomized study. PLoS One 2013; 8:e69210. [PMID: 23840910 PMCID: PMC3698086 DOI: 10.1371/journal.pone.0069210] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Accepted: 06/08/2013] [Indexed: 12/12/2022] Open
Abstract
Background The mechanisms by which tracheal occlusion (TO) improves alveolarization in congenital diaphragmatic hernia (CDH) are incompletely understood. Therefore transcriptional and histological effects of TO on alveolarization were studied in the rabbit model for CDH. The question of the best normalization strategy for gene expression analysis was also addressed. Methods Fetal rabbits were randomized for CDH or sham operation on gestational day 23/31 and for TO or sham operation on day 28/31 resulting in four study groups. Untouched littermates were added. At term and before lung harvest, fetuses were subjected to mechanical ventilation or not. Quantitative real-time PCR was performed on lungs from 4–5 fetuses of each group with and without previous ventilation. Stability of ten housekeeping genes (HKGs) and optimal number of HKGs for normalization were determined, followed by assessment of HKG expression levels. Expression levels of eleven target genes were studied in ventilated lungs, including genes regulating elastogenesis, cell-environment interactions, and thinning of alveolar walls. Elastic staining, immunohistochemistry and Western blotting completed gene analysis. Results Regarding HKG expression, TO increased β-actin and β-subunit of ATP synthase. Mechanical ventilation increased β-actin and β2-microglobulin. Flavoprotein subunit of succinate dehydrogenase and DNA topoisomerase were the most stable HKGs. CDH lungs showed disorganized elastin deposition with lower levels for tropoelastin, fibulin-5, tenascin-C, and α6-integrin. After TO, CDH lungs displayed a normal pattern of elastin distribution with increased levels for tropoelastin, fibulin-5, tenascin-C, α6-integrin, ß1-integrin, lysyl oxidase, and drebrin. TO increased transcription and immunoreactivity of tissue inhibitor of metalloproteinase-1. Conclusions Experimental TO might improve alveolarization through the mechanoregulation of crucial genes for late lung development. However part of the transcriptional changes involved genes that were not affected in CDH, raising the question of TO-induced disturbances of alveolar remodeling. Attention should also be paid to selection of HKGs for studies on mechanotransduction-mediated gene expressions.
Collapse
Affiliation(s)
- Aline Vuckovic
- Laboratory of Physiology and Physiopathology, Faculty of Medicine, Université Libre de Bruxelles, Brussels, Belgium.
| | | | | | | | | |
Collapse
|
23
|
Vuckovic A, Roubliova XI, Votino C, Naeije R, Jani JC. Signaling molecules in the fetal rabbit model for congenital diaphragmatic hernia. Pediatr Pulmonol 2012; 47:1088-96. [PMID: 22328320 DOI: 10.1002/ppul.22512] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Accepted: 01/05/2012] [Indexed: 01/23/2023]
Abstract
RATIONALE AND OBJECTIVES Little is known about molecular changes in lungs of fetal rabbits with surgically induced diaphragmatic hernia (DH). Therefore, we examined in this model gene expressions of pivotal molecules for the developing lung. METHODS At day 23 of gestation, DH was created in 12 fetuses from 4 does. Both lungs from six live DH fetuses and from six unoperated controls were harvested and weighed at term. Transcription of 15 genes involved in alveolarization, angiogenesis, regulation of vascular tone, or epithelial maturation was investigated by real-time quantitative polymerase chain reaction. MAIN RESULTS DH decreased lung-to-body weight ratio (P < 0.001). A bilateral downregulation was seen for genes encoding for tropoelastin (P < 0.01), lysyl oxidase (P < 0.05), fibulin 5 (P < 0.05), and cGMP specific phosphodiesterase 5 (P < 0.05). Lower mRNA levels for endothelial nitric oxide synthase occurred in the ipsilateral lung (P < 0.05). CONCLUSIONS Experimental DH in fetal rabbits disrupted transcription of genes implicated in lung growth and function. Similarities with the human disease make this model appropriate for investigation of new prenatal therapies.
Collapse
Affiliation(s)
- Aline Vuckovic
- Laboratory of Physiology and Physiopathology, Faculty of Medicine, Université Libre de Bruxelles, Brussels, Belgium.
| | | | | | | | | |
Collapse
|
24
|
Alphonse RS, Rajabali S, Thébaud B. Lung injury in preterm neonates: the role and therapeutic potential of stem cells. Antioxid Redox Signal 2012; 17:1013-40. [PMID: 22400813 DOI: 10.1089/ars.2011.4267] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Continuous improvements in perinatal care have allowed the survival of ever more premature infants, making the task of protecting the extremely immature lung from injury increasingly challenging. Premature infants at risk of developing chronic lung disease or bronchopulmonary dysplasia (BPD) are now born at the late canalicular stage of lung development, just when the airways become juxtaposed to the lung vasculature and when gas-exchange becomes possible. Readily available strategies, including improved antenatal management (education, regionalization, steroids, and antibiotics), together with exogenous surfactant and exclusive/early noninvasive ventilatory support, will likely decrease the incidence/severity of BPD over the next few years. Nonetheless, because of the extreme immaturity of the developing lung, the extent to which disruption of lung growth after prematurity and neonatal management lead to an earlier or more aggravated decline in respiratory function in later life is a matter of concern. Consequently, much more needs to be learned about the mechanisms of lung development, injury, and repair. Recent insight into stem cell biology has sparked interest for stem cells to repair damaged organs. This review summarizes the exciting potential of stem cell-based therapies for lung diseases in general and BPD in particular.
Collapse
|
25
|
Collins JJP, Kuypers E, Nitsos I, Jane Pillow J, Polglase GR, Kemp MW, Newnham JP, Cleutjens JP, Frints SGM, Kallapur SG, Jobe AH, Kramer BW. LPS-induced chorioamnionitis and antenatal corticosteroids modulate Shh signaling in the ovine fetal lung. Am J Physiol Lung Cell Mol Physiol 2012; 303:L778-87. [PMID: 22962010 DOI: 10.1152/ajplung.00280.2011] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Chorioamnionitis and antenatal corticosteroids mature the fetal lung functionally but disrupt late-gestation lung development. Because Sonic Hedgehog (Shh) signaling is a major pathway directing lung development, we hypothesized that chorioamnionitis and antenatal corticosteroids modulated Shh signaling, resulting in an altered fetal lung structure. Time-mated ewes with singleton ovine fetuses received an intra-amniotic injection of lipopolysaccharide (LPS) and/or maternal intramuscular betamethasone 7 and/or 14 days before delivery at 120 days gestational age (GA) (term = 150 days GA). Intra-amniotic LPS exposure decreased Shh mRNA levels and Gli1 protein expression, which was counteracted by both betamethasone pre- or posttreatment. mRNA and protein levels of fibroblast growth factor 10 and bone morphogenetic protein 4, which are important mediators of lung development, increased 2-fold and 3.5-fold, respectively, 14 days after LPS exposure. Both 7-day and 14-day exposure to LPS changed the mRNA levels of elastin (ELN) and collagen type I alpha 1 (Col1A1) and 2 (Col1A2), which resulted in fewer elastin foci and increased collagen type I deposition in the alveolar septa. Corticosteroid posttreatment prevented the decrease in ELN mRNA and increased elastin foci and decreased collagen type I deposition in the fetal lung. In conclusion, fetal lung exposure to LPS was accompanied by changes in key modulators of lung development resulting in abnormal lung structure. Betamethasone treatment partially prevented the changes in developmental processes and lung structure. This study provides new insights into clinically relevant prenatal exposures and fetal lung development.
Collapse
Affiliation(s)
- Jennifer J P Collins
- Department of Pediatrics, School for Oncology and Developmental Biology, School for Mental Health and Neuroscience, Maastricht University Medical Center, The Netherlands
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Arteaga-Solis E, Settembre C, Ballabio A, Karsenty G. Sulfatases are determinants of alveolar formation. Matrix Biol 2012; 31:253-60. [PMID: 22366163 DOI: 10.1016/j.matbio.2012.02.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2011] [Revised: 02/07/2012] [Accepted: 02/10/2012] [Indexed: 10/28/2022]
Abstract
Alveolar formation or alveolarization is orchestrated by a finely regulated and complex interaction between growth factors and extracellular matrix proteins. The lung parenchyma contains various extracellular matrix proteins including proteoglycans, which are composed of glycosaminoglycans (GAGs) linked to a protein core. Although GAGs are known to regulate growth factor distribution and activity according to their degree of sulfation the role of sulfated GAG in the respiratory system is not well understood. The degree of sulfation of GAGs is regulated in part, by sulfatases that remove sulfate groups. In vertebrates, the enzyme Sulfatase-Modifying Factor 1 (Sumf1) activates all sulfatases. Here we utilized mice lacking Sumf1(-/-) to study the importance of proteoglycan desulfation in lung development. The Sumf1(-/-) mice have normal lungs up until the onset of alveolarization at post-natal day 5 (P5). We detected increased deposition of sulfated GAG throughout the lung parenchyma and a decrease in alveolar septa formation. Moreover, stereological analysis showed that the alveolar volume is 20% larger in Sumf1(-/-) as compared to wild type (WT) mice at P10 and P30. Additionally, pulmonary function test was consistent with increased alveolar volume. Genetic experiments demonstrate that in Sumf1(-/-) mice arrest of alveolarization is independent of fibroblast growth factor signaling. In turn, the Sumf1(-/-) mice have increased transforming growth factor β (TGFβ) signaling and in vivo injection of TGFβ neutralizing antibody leads to normalization of alveolarization. Thus, absence of sulfatase activity increases sulfated GAG deposition in the lungs causing deregulation of TGFβ signaling and arrest of alveolarization.
Collapse
Affiliation(s)
- Emilio Arteaga-Solis
- Department of Genetics and Development, Columbia University, New York, NY 10032, USA
| | | | | | | |
Collapse
|
27
|
Concurrent inhibition of TGF-β and mitogen driven signaling cascades in Dupuytren's disease - non-surgical treatment strategies from a signaling point of view. Med Hypotheses 2011; 78:385-8. [PMID: 22196988 DOI: 10.1016/j.mehy.2011.11.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Accepted: 11/27/2011] [Indexed: 11/23/2022]
Abstract
Dupuytren's disease (DD) is a benign progressive fibro-proliferative disorder of the fascia palmaris of the hand. Currently, treatment consists of surgical excision with a relatively high recurrence rate and risk of complications. To improve long-term outcome of DD treatment, research focus has shifted towards molecular targets for DD as an alternative to surgery. Therefore, complete and exact understanding of the cause of DD is needed. Transforming growth factor (TGF)-β is considered a key player in DD. We recently showed that increased TGF-β expression in DD correlates not only with elevated expression and activation of downstream Smad effectors, but also with overactive ERK1/2 MAP kinase signaling. Both TGF-β/Smad and non-Smad signaling pathways increase expression of key fibrotic markers and contractility of Dupuytren's myofibroblasts. What is not yet known is whether these two signaling cascades each accelerate DD autonomously, successively or in conjunction. Elucidation of this mechanism will help develop new potential non-surgical treatments. We hypothesize that TGF-β-induced short-term activation of the MAPK pathway leads to an autonomous non-Smad driven fibrosis. Therefore, successful treatment strategies will target not only TGF-β/Smad, but also intracellular MAPK signaling. In this review we discuss possible scenarios in which such a drift from TGF-β induced Smad signaling to autonomous non-Smad signaling could be observed in DD. The potential therapeutic effects of small cytokine signaling cascades inhibitors, such as TGF-β type I receptor-, (pan-) tyrosine- or ERK1/2 MAP-kinase inhibitor will be highlighted. To abrogate the fibrotic trait and the recurrence of DD, we speculate on sequential and co-application of such molecules in order to provide possible new non-operative strategies for DD.
Collapse
|
28
|
Franco-Montoya ML, Boucherat O, Thibault C, Chailley-Heu B, Incitti R, Delacourt C, Bourbon JR. Profiling target genes of FGF18 in the postnatal mouse lung: possible relevance for alveolar development. Physiol Genomics 2011; 43:1226-40. [PMID: 21878612 DOI: 10.1152/physiolgenomics.00034.2011] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Better understanding alveolarization mechanisms could help improve prevention and treatment of diseases characterized by reduced alveolar number. Although signaling through fibroblast growth factor (FGF) receptors is essential for alveolarization, involved ligands are unidentified. FGF18, the expression of which peaks coincidentally with alveolar septation, is likely to be involved. Herein, a mouse model with inducible, lung-targeted FGF18 transgene was used to advance the onset of FGF18 expression peak, and genome-wide expression changes were determined by comparison with littermate controls. Quantitative RT-PCR was used to confirm expression changes of selected up- and downregulated genes and to determine their expression profiles in the course of lung postnatal development. This allowed identifying so-far unknown target genes of the factor, among which a number are known to be involved in alveolarization. The major target was adrenomedullin, a promoter of lung angiogenesis and alveolar development, whose transcript was increased 6.9-fold. Other genes involved in angiogenesis presented marked expression increases, including Wnt2 and cullin2. Although it appeared to favor cell migration notably through enhanced expression of Snai1/2, FGF18 also induced various changes consistent with prevention of epithelial-mesenchymal transition. Together with antifibrotic effects driven by induction of E prostanoid receptor 2 and repression of numerous myofibroblast markers, this could prevent alveolar septation-driving mechanisms from becoming excessive and deleterious. Last, FGF18 up- or downregulated genes of extracellular matrix components and epithelial cell markers previously shown to be up- or downregulated during alveolarization. These findings therefore argue for an involvement of FGF18 in the control of various developmental events during the alveolar stage.
Collapse
|
29
|
Choi CW. Lung interstitial cells during alveolarization. KOREAN JOURNAL OF PEDIATRICS 2010; 53:979-84. [PMID: 21253310 PMCID: PMC3021730 DOI: 10.3345/kjp.2010.53.12.979] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Accepted: 11/30/2010] [Indexed: 02/01/2023]
Abstract
Recent progress in neonatal medicine has enabled survival of many extremely low-birth-weight infants. Prenatal steroids, surfactants, and non-invasive ventilation have helped reduce the incidence of the classical form of bronchopulmonary dysplasia characterized by marked fibrosis and emphysema. However, a new form of bronchopulmonary dysplasia marked by arrest of alveolarization remains a complication in the postnatal course of extremely low-birth-weight infants. To better understand this challenging complication, detailed alveolarization mechanisms should be delineated. Proper alveolarization involves the temporal and spatial coordination of a number of cells, mediators, and genes. Cross-talk between the mesenchyme and the epithelium through soluble and diffusible factors are key processes of alveolarization. Lung interstitial cells derived from the mesenchyme play a crucial role in alveolarization. Peak alveolar formation coincides with intense lung interstitial cell proliferation. Myofibroblasts are essential for secondary septation, a critical process of alveolarization, and localize to the front lines of alveologenesis. The differentiation and migration of myofibroblasts are strictly controlled by various mediators and genes. Disruption of this finely controlled mechanism leads to abnormal alveolarization. Since arrest in alveolarization is a hallmark of a new form of bronchopulmonary dysplasia, knowledge regarding the role of lung interstitial cells during alveolarization and their control mechanism will enable us to find more specific therapeutic strategies for bronchopulmonary dysplasia. In this review, the role of lung interstitial cells during alveolarization and control mechanisms of their differentiation and migration will be discussed.
Collapse
Affiliation(s)
- Chang Won Choi
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea
| |
Collapse
|
30
|
Srisuma S, Bhattacharya S, Simon DM, Solleti SK, Tyagi S, Starcher B, Mariani TJ. Fibroblast growth factor receptors control epithelial-mesenchymal interactions necessary for alveolar elastogenesis. Am J Respir Crit Care Med 2010; 181:838-50. [PMID: 20093646 DOI: 10.1164/rccm.200904-0544oc] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE The mechanisms contributing to alveolar formation are poorly understood. A better understanding of these processes will improve efforts to ameliorate lung disease of the newborn and promote alveolar repair in the adult. Previous studies have identified impaired alveogenesis in mice bearing compound mutations of fibroblast growth factor (FGF) receptors (FGFRs) 3 and 4, indicating that these receptors cooperatively promote postnatal alveolar formation. OBJECTIVES To determine the molecular and cellular mechanisms of FGF-mediated alveolar formation. METHODS Compound FGFR3/FGFR4-deficient mice were assessed for temporal changes in lung growth, airspace morphometry, and genome-wide expression. Observed gene expression changes were validated using quantitative real-time RT-PCR, tissue biochemistry, histochemistry, and ELISA. Autocrine and paracrine regulatory mechanisms were investigated using isolated lung mesenchymal cells and type II pneumocytes. MEASUREMENTS AND MAIN RESULTS Quantitative analysis of airspace ontogeny confirmed a failure of secondary crest elongation in compound mutant mice. Genome-wide expression profiling identified molecular alterations in these mice involving aberrant expression of numerous extracellular matrix molecules. Biochemical and histochemical analysis confirmed changes in elastic fiber gene expression resulted in temporal increases in elastin deposition with the loss of typical spatial restriction. No abnormalities in elastic fiber gene expression were observed in isolated mesenchymal cells, indicating that abnormal elastogenesis in compound mutant mice is not cell autonomous. Increased expression of paracrine factors, including insulin-like growth factor-1, in freshly-isolated type II pneumocytes indicated that these cells contribute to the observed pathology. CONCLUSIONS Epithelial/mesenchymal signaling mechanisms appear to contribute to FGFR-dependent alveolar elastogenesis and proper airspace formation.
Collapse
Affiliation(s)
- Sorachai Srisuma
- Division of Neonatology and Center for Pediatric Biomedical Research, University of Rochester Medical Center, Rochester, New York 14642, USA
| | | | | | | | | | | | | |
Collapse
|
31
|
Yanagisawa H, Schluterman MK, Brekken RA. Fibulin-5, an integrin-binding matricellular protein: its function in development and disease. J Cell Commun Signal 2009; 3:337-47. [PMID: 19798595 PMCID: PMC2778585 DOI: 10.1007/s12079-009-0065-3] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2009] [Accepted: 08/31/2009] [Indexed: 01/03/2023] Open
Abstract
Interactions between the extracellular matrix (ECM) and cells are critical in embryonic development, tissue homeostasis, physiological remodeling, and tumorigenesis. Matricellular proteins, a group of ECM components, mediate cell-ECM interactions. One such molecule, Fibulin-5 is a 66-kDa glycoprotein secreted by various cell types, including vascular smooth muscle cells (SMCs), fibroblasts, and endothelial cells. Fibulin-5 contributes to the formation of elastic fibers by binding to structural components including tropoelastin and fibrillin-1, and to cross-linking enzymes, aiding elastic fiber assembly. Mice deficient in the fibulin-5 gene (Fbln5) exhibit systemic elastic fiber defects with manifestations of loose skin, tortuous aorta, emphysematous lung and genital prolapse. Although Fbln5 expression is down-regulated after birth, following the completion of elastic fiber formation, expression is reactivated upon tissue injury, affecting diverse cellular functions independent of its elastogenic function. Fibulin-5 contains an evolutionally conserved arginine-glycine-aspartic acid (RGD) motif in the N-terminal region, which mediates binding to a subset of integrins, including alpha5beta1, alphavbeta3, and alphavbeta5. Fibulin-5 enhances substrate attachment of endothelial cells, while inhibiting migration and proliferation in a cell type- and context-dependent manner. The antagonistic function of fibulin-5 in angiogenesis has been demonstrated in vitro and in vivo; fibulin-5 may block angiogenesis by inducing the anti-angiogenic molecule thrompospondin-1, by antagonizing VEGF(165)-mediated signaling, and/or by antagonizing fibronectin-mediated signaling through directly binding and blocking the alpha5beta1 fibronectin receptor. The overall effect of fibulin-5 on tumor growth depends on the balance between the inhibitory property of fibulin-5 on angiogenesis and the direct effect of fibulin-5 on proliferation and migration of tumor cells. However, the effect of tumor-derived versus host microenvironment-derived fibulin-5 remains to be evaluated.
Collapse
Affiliation(s)
- Hiromi Yanagisawa
- Department of Molecular Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9148 USA
| | - Marie K. Schluterman
- Department of Surgery, Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-8593 USA
| | - Rolf A. Brekken
- Department of Surgery, Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-8593 USA
| |
Collapse
|
32
|
Munoz-Pinto DJ, Jimenez-Vergara AC, Gelves LM, McMahon RE, Guiza-Arguello V, Hahn MS. Probing vocal fold fibroblast response to hyaluronan in 3D contexts. Biotechnol Bioeng 2009; 104:821-31. [PMID: 19718686 DOI: 10.1002/bit.22436] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A number of treatments are being investigated for vocal fold (VF) scar, including designer implants. The aim of the present study was to validate a 3D model system for probing the effects of various bioactive moieties on VF fibroblast (VFF) behavior toward rational implant design. We selected poly(ethylene glycol) diacrylate (PEGDA) hydrogels as our base-scaffold due to their broadly tunable material properties. However, since cells encapsulated in PEGDA hydrogels are generally forced to take on rounded/stellate morphologies, validation of PEGDA gels as a 3D VFF model system required that the present work directly parallel previous studies involving more permissive scaffolds. We therefore chose to focus on hyaluronan (HA), a polysaccharide that has been a particular focus of the VF community. Toward this end, porcine VFFs were encapsulated in PEGDA hydrogels containing consistent levels of high Mw HA (HA(HMW)), intermediate Mw HA (HA(IMW)), or the control polysaccharide, alginate, and cultured for 7 and 21 days. HA(HMW) promoted sustained increases in active ERK1/2 relative to HA(IMW). Furthermore, VFFs in HA(IMW) gels displayed a more myofibroblast-like phenotype, higher elastin production, and greater protein kinase C (PkC) levels at day 21 than VFFs in HA(HMW) and alginate gels. The present results are in agreement with a previous 3D study of VFF responses to HA(IMW) relative to alginate in collagen-based scaffolds permissive of cell elongation, indicating that PEGDA hydrogels may serve as an effective 3D model system for probing at least certain aspects of VFF behavior.
Collapse
Affiliation(s)
- Dany J Munoz-Pinto
- Department of Chemical Engineering, Texas A&M University, 200 Jack E Brown Bldg, 3122 TAMU, College Station, Texas 77843-3122, USA
| | | | | | | | | | | |
Collapse
|
33
|
Paxson JA, Parkin CD, Iyer LK, Mazan MR, Ingenito EP, Hoffman AM. Global gene expression patterns in the post-pneumonectomy lung of adult mice. Respir Res 2009; 10:92. [PMID: 19804646 PMCID: PMC2770038 DOI: 10.1186/1465-9921-10-92] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2009] [Accepted: 10/05/2009] [Indexed: 11/29/2022] Open
Abstract
Background Adult mice have a remarkable capacity to regenerate functional alveoli following either lung resection or injury that exceeds the regenerative capacity observed in larger adult mammals. The molecular basis for this unique capability in mice is largely unknown. We examined the transcriptomic responses to single lung pneumonectomy in adult mice in order to elucidate prospective molecular signaling mechanisms used in this species during lung regeneration. Methods Unilateral left pneumonectomy or sham thoracotomy was performed under general anesthesia (n = 8 mice per group for each of the four time points). Total RNA was isolated from the remaining lung tissue at four time points post-surgery (6 hours, 1 day, 3 days, 7 days) and analyzed using microarray technology. Results The observed transcriptomic patterns revealed mesenchymal cell signaling, including up-regulation of genes previously associated with activated fibroblasts (Tnfrsf12a, Tnc, Eln, Col3A1), as well as modulation of Igf1-mediated signaling. The data set also revealed early down-regulation of pro-inflammatory cytokine transcripts and up-regulation of genes involved in T cell development/function, but few similarities to transcriptomic patterns observed during embryonic or post-natal lung development. Immunohistochemical analysis suggests that early fibroblast but not myofibroblast proliferation is important during lung regeneration and may explain the preponderance of mesenchymal-associated genes that are over-expressed in this model. This again appears to differ from embryonic alveologenesis. Conclusion These data suggest that modulation of mesenchymal cell transcriptome patterns and proliferation of S100A4 positive mesenchymal cells, as well as modulation of pro-inflammatory transcriptome patterns, are important during post-pneumonectomy lung regeneration in adult mice.
Collapse
Affiliation(s)
- Julia A Paxson
- Department of Clinical Sciences, Lung Function Testing Laboratory, Cummings School of Veterinary Medicine, Tufts University, North Grafton, MA, USA.
| | | | | | | | | | | |
Collapse
|
34
|
Bourbon JR, Boucherat O, Boczkowski J, Crestani B, Delacourt C. Bronchopulmonary dysplasia and emphysema: in search of common therapeutic targets. Trends Mol Med 2009; 15:169-79. [DOI: 10.1016/j.molmed.2009.02.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2009] [Revised: 02/11/2009] [Accepted: 02/11/2009] [Indexed: 11/15/2022]
|
35
|
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.
Collapse
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
| | | | | | | | | | | | | |
Collapse
|
36
|
Boucherat O, Benachi A, Barlier-Mur AM, Franco-Montoya ML, Martinovic J, Thébaud B, Chailley-Heu B, Bourbon JR. Decreased lung fibroblast growth factor 18 and elastin in human congenital diaphragmatic hernia and animal models. Am J Respir Crit Care Med 2007; 175:1066-77. [PMID: 17303798 DOI: 10.1164/rccm.200601-050oc] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Lung hypoplasia in congenital diaphragmatic hernia (CDH) seems to involve impaired alveolar septation. We hypothesized that disturbed deposition of elastin and expression of fibroblast growth factor 18 (FGF18), an elastogenesis stimulus, occurs in CDH. OBJECTIVES To document FGF18 and elastin in human CDH and ovine surgical and rat nitrofen models and to use models to evaluate the benefit of treatments. METHODS Human CDH and control lungs were collected post mortem. Diaphragmatic hernia was created in sheep at 85 days; fetal lungs were collected at 139 days (term = 145 days). Pregnant rats received nitrofen at 12 days; fetal lungs were collected at 21 days (term = 22 days). Some of the sheep fetuses with hernia underwent tracheal occlusion (TO); some of the nitrofen-treated pregnant rats received vitamin A. Both treatments are known to promote lung growth. MEASUREMENTS AND MAIN RESULTS Coincidental with the onset of secondary septation, FGF18 protein increased threefold in control human lungs, which failed to occur in CDH. FGF18 labeling was found in interstitial cells of septa. Elastin staining demonstrated poor septation and markedly decreased elastin density in CDH lungs. Consistently, lung FGF18 transcripts were diminished 60 and 83% by CDH in sheep and rats, respectively, and elastin density and expression were diminished. TO and vitamin A restored FGF18 and elastin expression in sheep and rats, respectively. TO restored elastin density. CONCLUSIONS Impaired septation in CDH is associated with decreased FGF18 expression and elastic fiber deposition. Simultaneous correction of FGF18 and elastin defects by TO and vitamin A suggests that defective elastogenesis may result, at least partly, from FGF18 deficiency.
Collapse
|
37
|
Kuang PP, Zhang XH, Rich CB, Foster JA, Subramanian M, Goldstein RH. Activation of elastin transcription by transforming growth factor-beta in human lung fibroblasts. Am J Physiol Lung Cell Mol Physiol 2007; 292:L944-52. [PMID: 17209135 DOI: 10.1152/ajplung.00184.2006] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Elastin synthesis is essential for lung development and postnatal maturation as well as for repair following injury. Using human embryonic lung fibroblasts that express undetectable levels of elastin as assessed by Northern analyses, we found that treatment with exogenous transforming growth factor-beta (TGF-beta) induced rapid and transient increases in levels of elastin heterogeneous nuclear RNA (hnRNA) followed by increases of elastin mRNA and protein expression. In fibroblasts derived from transgenic mice, TGF-beta induced increases in the expression of a human elastin gene promoter fragment driving a chloramphenicol acetyl transferase reporter gene. The induction of elastin hnRNA and mRNA expression by TGF-beta was abolished by pretreatments with TGF-beta receptor I inhibitor, global transcription inhibitor actinomycin D, and partially blocked by addition of protein synthesis inhibitor cycloheximide, but was not affected by the p44/42 MAPK inhibitor U0126. Pretreatment with the p38 MAPK inhibitor SB-203580 also partially attenuated the levels of TGF-beta-induced elastin mRNA but not its hnRNA. Western analysis indicated that TGF-beta stimulated Akt phosphorylation. Inhibition of phosphatidylinositol 3-kinase and Akt phosphorylation by LY-294002 abolished TGF-beta-induced increases in elastin hnRNA and mRNA expression. Treatment of lung fibroblasts with interleukin-1beta or the histone deacetylase inhibitor trichostatin A inhibited TGF-beta-induced elastin mRNA and hnRNA expression by a mechanism that involved inhibition of Akt phosphorylation. Downregulation of Akt2 but not Akt1 expression employing small interfering RNA duplexes blocked TGF-beta-induced increases of elastin hnRNA and mRNA levels. Together, our results demonstrated that TGF-beta activates elastin transcription that is dependent on phosphatidylinositol 3-kinase/Akt activity.
Collapse
Affiliation(s)
- Ping-Ping Kuang
- Pulmonary Center, Boston University School of Medicine, 80 E. Concord St., Boston, MA 02118, USA.
| | | | | | | | | | | |
Collapse
|
38
|
Shigemura N, Okumura M, Mizuno S, Imanishi Y, Matsuyama A, Shiono H, Nakamura T, Sawa Y. Lung Tissue Engineering Technique with Adipose Stromal Cells Improves Surgical Outcome for Pulmonary Emphysema. Am J Respir Crit Care Med 2006; 174:1199-205. [PMID: 17008641 DOI: 10.1164/rccm.200603-406oc] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
RATIONALE AND OBJECTIVES Hepatocyte growth factor (HGF) is a potent regenerative factor generated after a lung injury, and HGF supplementation after surgical reduction has been shown to enhance compensatory growth in remnant lungs and improve pathophysiologic conditions in a rat model of emphysema. Adipose tissue-derived stromal cells (ASCs) produce a large amount of angiogenic factors, including HGF. After lung volume reduction surgery (LVRS), we treated rats by implanting HGF-secreting ASCs with a scaffold onto the remnant lung tissue to determine the usefulness of this technique for treating respiratory dysfunction. METHODS AND MAIN RESULTS Cells were isolated from rat inguinal adipose tissue and characterized by flow cytometry. ASCs were cultured on a polyglycolic acid felt sheet as a sealant material, and were shown to secrete significantly greater amounts of HGF than other angiogenic factors. Next, ASCs on polyglycolic acid felt sheets were used to cover the cut edge of the remaining lungs after LVRS for emphysema in rats. One week after implantation of the ASCs, both alveolar and vascular regeneration were significantly accelerated as compared with the rats that underwent LVRS alone. Consequently, gas exchange and exercise tolerance were also significantly restored, with these good results persisting for more than 1 mo. CONCLUSIONS The present findings demonstrate the therapeutic potential of cell therapy using ASCs with a scaffold for selective delivery of HGF to remnant lungs, which resulted in enhancement of compensatory growth, after surgical resection. This approach may provide a new strategy for lung tissue engineering to improve LVRS outcome.
Collapse
Affiliation(s)
- Norihisa Shigemura
- Division of Cardiothoracic Surgery, Department of Surgery, Course of Advanced Medicine, Medical Center for Translational Research, Osaka University Graduate School of Medicine, Osaka, Japan
| | | | | | | | | | | | | | | |
Collapse
|
39
|
Shigemura N, Okumura M, Mizuno S, Imanishi Y, Nakamura T, Sawa Y. Autologous transplantation of adipose tissue-derived stromal cells ameliorates pulmonary emphysema. Am J Transplant 2006; 6:2592-600. [PMID: 17049053 DOI: 10.1111/j.1600-6143.2006.01522.x] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Adipose tissue is a useful tool for management of most complex cardiothoracic problems, including the reinforcement of damaged lungs, and adipose tissue-derived stromal cells (ASCs) have been suggested to secrete hepatocyte growth factor (HGF), a multipotent regenerative factor that contributes to the repair process after lung injury. The goal of this study was to demonstrate the therapeutic impact of autologous transplantation of ASCs through HGF supplementation for the enhancement of alveolar repair in a rat model of emphysema. ASCs were isolated from inguinal subcutaneous fat pads and characterized by flow cytometry. Cultured ASC were found to secrete significantly larger amounts of HGF (15 112 +/- 1628 pg per 10(6) cells) than other angiogenic factors. Transplantation of ASCs into elastase-treated emphysema models induced a significant increase in endogenous HGF expression in lung tissues with a small amount of increase in other organs, with the high levels lasting for up to 4 weeks after transplantation. Further, alveolar and vascular regeneration were significantly enhanced via inhibition of alveolar cell apoptosis, enhancement of epithelial cell proliferation and promotion of angiogenesis in pulmonary vasculature, leading to restoration of pulmonary function affected by emphysema. These data suggest that autologous ASC cell therapy may have a therapeutic potential for pulmonary emphysema, through inducing HGF expression selectively in injured lung tissues.
Collapse
Affiliation(s)
- N Shigemura
- Division of Cardiothoracic Surgery, Osaka University Graduate School of Medicine, Osaka, Japan
| | | | | | | | | | | |
Collapse
|
40
|
Yi M, Belcastro R, Shek S, Luo D, Post M, Tanswell AK. Fibroblast growth factor-2 and receptor-1alpha(IIIc) regulate postnatal rat lung cell apoptosis. Am J Respir Crit Care Med 2006; 174:581-9. [PMID: 16728710 DOI: 10.1164/rccm.200511-1718oc] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
RATIONALE Fibroblast growth factor receptor-1alpha(IIIc) [FGF-R1alpha(IIIc)] regulates recovery of neonatal rat lung growth, after 95% oxygen-mediated growth arrest. Its role in normal postnatal alveologenesis is unknown. OBJECTIVE To determine if FGF-R1alpha(IIIc) regulates normal postnatal alveologenesis. METHODS Truncated soluble FGF-R1alpha(IIIc) or neutralizing antibodies to FGF-1 or FGF-2 were injected intraperitoneally into 3-d-old rats. The pups were killed at Day 7 for studies of alveolar development. MEASUREMENTS AND MAIN RESULTS Injected, truncated soluble FGF-R1alpha(IIIc) inhibited phosphorylation of the endogenous FGF-R1, and downstream pathway, and paradoxically increased lung DNA content and tissue fraction while inhibiting lung cell DNA synthesis. The increase in tissue thickness was due to reduced apoptosis, as indicated by reductions in cleaved effector caspases 3 and 7. Inhibition of the intrinsic apoptosis pathway was suggested by decreases in the proapoptotic protein Bax and mitochondrial cytochrome c release, and an increase in the antiapoptotic protein Bcl-x(L). Injected antibodies to FGF-1 and FGF-2 had no effect on DNA synthesis, but both increased Bcl-x(L) content and decreased cytochrome c release and cleaved caspase-7 protein expression. However, only injection of the antibody to FGF-2 replicated the increased tissue fraction and inhibited apoptosis observed with the injection of truncated soluble FGF-R1alpha(IIIc). CONCLUSIONS Inhibition of ligand binding, most likely of FGF-2, to the FGF-R1alpha(IIIc) inhibits normal postnatal lung cell apoptosis.
Collapse
Affiliation(s)
- Man Yi
- Canadian Institute of Health Research Group in Lung Development, Lung Biology Programme, Hospital for Sick Children Research Institute, Toronto, ON, Canada
| | | | | | | | | | | |
Collapse
|
41
|
Lopez E, Boucherat O, Franco-Montoya ML, Bourbon JR, Delacourt C, Jarreau PH. Nitric oxide donor restores lung growth factor and receptor expression in hyperoxia-exposed rat pups. Am J Respir Cell Mol Biol 2006; 34:738-45. [PMID: 16484688 DOI: 10.1165/rcmb.2005-0254oc] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Exposure of newborn rats to hyperoxia impairs alveolarization. Nitric oxide (NO) may prevent this evolution. Angiogenesis and factors involved in this process, but also other growth factors (GFs) involved in alveolar development, are likely potential therapeutic targets for NO. We studied the effects of the NO donor, [Z]-1-[N-(2-aminoethyl)-N-(2-ammonioethyl)aminio]diazen-1-ium-1, 2-diolate, also termed DETANONOate (D-NO), on hyperoxia-induced changes in key regulatory factors of alveolar development in neonatal rats, and its possible preventive effect on the physiologic consequences of hyperoxia. Newborn rat pups were randomized at birth to hyperoxia (> 95% O2) or room air exposure for 6 or 10 d, while receiving D-NO or its diluent. On Day 6, several GFs and their receptors were studied at pre- and/or post-translational levels. Elastin transcript determination on Day 6, and elastin deposition in tissue and morphometric analysis of the lungs on Day 10, were also performed. Hyperoxia decreased the expression of vascular endothelial growth factor (VEGF) receptor (VEGFR) 2, fibroblast growth factor (FGF)-18, and FGF receptors (FGFRs) FGFR3 and FGFR4, increased mortality, and impaired alveolarization and capillary growth. D-NO treatment of hyperoxia-exposed pups restored the expression level of FGF18 and FGFR4, induced an increase of both VEGF mRNA and protein, enhanced elastin expression, and partially restored elastin deposition in alveolar walls. Although, under the present conditions, D-NO failed to prevent the physiologic consequences of hyperoxia in terms of survival and lung alveolarization, our findings demonstrate molecular effects of NO on GFs involved in alveolar development that may have contributed to the protective effects previously reported for NO.
Collapse
Affiliation(s)
- Emmanuel Lopez
- Institut National de la Santé et de la Recherche Médicale, Université Paris, Faculté de Médecine, Créteil, France
| | | | | | | | | | | |
Collapse
|
42
|
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.
Collapse
Affiliation(s)
- Jacques Bourbon
- Inserm U651-Université Paris XII, Faculté de Médecine, Créteil, France.
| | | | | | | |
Collapse
|
43
|
Warburton D, Bellusci S, De Langhe S, Del Moral PM, Fleury V, Mailleux A, Tefft D, Unbekandt M, Wang K, Shi W. Molecular mechanisms of early lung specification and branching morphogenesis. Pediatr Res 2005; 57:26R-37R. [PMID: 15817505 DOI: 10.1203/01.pdr.0000159570.01327.ed] [Citation(s) in RCA: 164] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The "hard wiring" encoded within the genome that determines the emergence of the laryngotracheal groove and subsequently early lung branching morphogenesis is mediated by finely regulated, interactive growth factor signaling mechanisms that determine the automaticity of branching, interbranch length, stereotypy of branching, left-right asymmetry, and finally gas diffusion surface area. The extracellular matrix is an important regulator as well as a target for growth factor signaling in lung branching morphogenesis and alveolarization. Coordination not only of epithelial but also endothelial branching morphogenesis determines bronchial branching and the eventual alveolar-capillary interface. Improved prospects for lung protection, repair, regeneration, and engineering will depend on more detailed understanding of these processes. Herein, we concisely review the functionally integrated morphogenetic signaling network comprising the critical bone morphogenetic protein, fibroblast growth factor, Sonic hedgehog, transforming growth factor-beta, vascular endothelial growth factor, and Wnt signaling pathways that specify and drive early embryonic lung morphogenesis.
Collapse
Affiliation(s)
- David Warburton
- Developmental Biology Program, The Saban Research Institute of Childrens Hospital Los Angeles, CA 90027, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|