scholarly journals Editorial: Branching Morphogenesis During Embryonic Lung Development

Author(s):  
Elie El Agha ◽  
Dagmar Iber ◽  
David Warburton
1991 ◽  
Vol 146 (2) ◽  
pp. 531-541 ◽  
Author(s):  
Lucia Schuger ◽  
Amy P.N. Skubitz ◽  
K.Sue O'Shea ◽  
Jane F. Chang ◽  
James Varani

2004 ◽  
Vol 286 (2) ◽  
pp. L293-L300 ◽  
Author(s):  
Wei Shi ◽  
Hui Chen ◽  
Jianping Sun ◽  
Cheng Chen ◽  
Jingsong Zhao ◽  
...  

Early embryonic lung branching morphogenesis is regulated by many growth factor-mediated pathways. Bone morphogenetic protein 4 (BMP4) is one of the morphogens that stimulate epithelial branching in mouse embryonic lung explant culture. To further understand the molecular mechanisms of BMP4-regulated lung development, we studied the biological role of Smad-ubiquitin regulatory factor 1 (Smurf1), an ubiquitin ligase specific for BMP receptor-regulated Smads, during mouse lung development. The temporo-spatial expression pattern of Smurf1 in mouse embryonic lung was first determined by quantitative real-time PCR and immunohistochemistry. Overexpression of Smurf1 in airway epithelial cells by intratracheal introduction of recombinant adenoviral vector dramatically inhibited embryonic day (E) 11.5 lung explant growth in vitro. This inhibition of lung epithelial branching was restored by coexpression of Smad1 or by addition of soluble BMP4 ligand into the culture medium. Studies at the cellular level show that overexpression of Smurf1 reduced epithelial cell proliferation and differentiation, as documented by reduced PCNA-positive cell index and by reduced mRNA levels for surfactant protein C and Clara cell protein 10 expression. Further studies found that overexpression of Smurf1 reduced BMP-specific Smad1 and Smad5, but not Smad8, protein levels. Thus overexpression of Smurf1 specifically promotes Smad1 and Smad5 ubiquitination and degradation in embryonic lung epithelium, thereby modulating the effects of BMP4 on embryonic lung growth.


2013 ◽  
pp. 1-1
Author(s):  
Rowan Hardy ◽  
Aiqing Li ◽  
Shihani Stoner ◽  
Jan Tuckermann ◽  
Markus Seibel ◽  
...  

Author(s):  
Soichi Shibuya ◽  
Jessica Allen-Hyttinen ◽  
Paolo De Coppi ◽  
Federica Michielin

Abstract Purpose This paper aims to build upon previous work to definitively establish in vitro models of murine pseudoglandular stage lung development. These can be easily translated to human fetal lung samples to allow the investigation of lung development in physiologic and pathologic conditions. Methods Lungs were harvested from mouse embryos at E12.5 and cultured in three different settings, i.e., whole lung culture, mesenchyme-free epithelium culture, and organoid culture. For the whole lung culture, extracted lungs were embedded in Matrigel and incubated on permeable filters. Separately, distal epithelial tips were isolated by firstly removing mesothelial and mesenchymal cells, and then severing the tips from the airway tubes. These were then cultured either in branch-promoting or self-renewing conditions. Results Cultured whole lungs underwent branching morphogenesis similarly to native lungs. Real-time qPCR analysis demonstrated expression of key genes essential for lung bud formation. The culture condition for epithelial tips was optimized by testing different concentrations of FGF10 and CHIR99021 and evaluating branching formation. The epithelial rudiments in self-renewing conditions formed spherical 3D structures with homogeneous Sox9 expression. Conclusion We report efficient protocols for ex vivo culture systems of pseudoglandular stage mouse embryonic lungs. These models can be applied to human samples and could be useful to paediatric surgeons to investigate normal lung development, understand the pathogenesis of congenital lung diseases, and explore novel therapeutic strategies.


Author(s):  
Qing Miao ◽  
Hui Chen ◽  
Yongfeng Luo ◽  
Joanne Chiu ◽  
Ling Chu ◽  
...  

The TGF-β signaling pathway plays a pivotal role in controlling organogenesis during fetal development. Although the role of TGF-β signaling in promoting lung alveolar epithelial growth has been determined, mesenchymal TGF-β signaling in regulating lung development has not been studied in vivo due to a lack of genetic tools for specifically manipulating gene expression in lung mesenchymal cells. Therefore, the integral roles of TGF-β signaling in regulating lung development and congenital lung diseases are not completely understood. Using a Tbx4 lung enhancer-driven Tet-On inducible Cre transgenic mouse system, we have developed a mouse model in which lung mesenchyme-specific deletion of TGF-β receptor 2 gene (Tgfbr2) is achieved. Reduced airway branching accompanied by defective airway smooth muscle growth and later peripheral cystic lesions occurred when lung mesenchymal Tgfbr2 was deleted from embryonic day 13.5 to 15.5, resulting in postnatal death due to respiratory insufficiency. Although cell proliferation in both lung epithelium and mesenchyme was reduced, epithelial differentiation was not significantly affected. Tgfbr2 downstream Smad-independent ERK1/2 may mediate these mesenchymal effects of TGF-β signaling through the GSK3β--β-catenin--Wnt canonical pathway in fetal mouse lung. Our study suggests that Tgfbr2-mediated TGF-β signaling in prenatal lung mesenchyme is essential for lung development and maturation, and defective TGF-β signaling in lung mesenchyme may be related to abnormal airway branching morphogenesis and congenital airway cystic lesions.


2022 ◽  
Author(s):  
Kasra Khalaj ◽  
Rebeca Lopes Figueira ◽  
Lina Antounians ◽  
Sree Gandhi ◽  
Matthew Wales ◽  
...  

Pulmonary hypoplasia secondary to congenital diaphragmatic hernia (CDH) is characterized by impaired branching morphogenesis and differentiation. We have previously demonstrated that administration of extracellular vesicles derived from rat amniotic fluid stem cells (AFSC-EVs) rescues development of hypoplastic lungs at the pseudoglandular and alveolar stages in rodent models of CDH. Herein, we tested whether AFSC-EVs exert their regenerative effects at the canalicular and saccular stages, as these are translationally relevant for clinical intervention. To induce fetal pulmonary hypoplasia, we gavaged rat dams with nitrofen at embryonic day 9.5 and demonstrated that nitrofen-exposed lungs had impaired branching morphogenesis, dysregulated signaling pathways relevant to lung development (FGF10/FGFR2, ROBO/SLIT, Ephrin, Neuropilin 1, beta-catenin) and impaired epithelial and mesenchymal cell marker expression at both stages. AFSC-EVs administered to nitrofen-exposed lung explants rescued airspace density and increased the expression levels of key factors responsible for branching morphogenesis. Moreover, AFSC-EVs rescued the expression of alveolar type 1 and 2 cell markers at both canalicular and saccular stages, and restored markers of club, ciliated epithelial, and pulmonary neuroendocrine cells at the saccular stage. AFSC-EV treated lungs also had restored markers of lipofibroblasts and PDGFRA+ cells to control levels at both stages. EV tracking showed uptake of AFSC-EV RNA cargo throughout the fetal lung and an mRNA-miRNA network analysis identified that several miRNAs responsible for regulating lung development processes were contained in the AFSC-EV cargo. These findings suggest that AFSC-EV based therapies hold potential for restoring fetal lung growth and maturation in babies with pulmonary hypoplasia secondary to CDH.


Development ◽  
1993 ◽  
Vol 119 (2) ◽  
pp. 485-499 ◽  
Author(s):  
C.B. Moens ◽  
B.R. Stanton ◽  
L.F. Parada ◽  
J. Rossant

Two types of mutant allele, one leaky and one null, have been generated by gene targeting at the N-myc locus in embryonic stem cells and the phenotypes of mice homozygous for these mutations have been described. These mutations have shown that N-myc has a number of functions during development, including a role in branching morphogenesis in the lung, which manifests itself at birth in mice homozygous for the leaky allele, and roles in the development of the mesonephric tubules, the neuroepithelium, the sensory ganglia, the gut and the heart, which become evident at midgestation in embryos homozygous for the null allele. In an attempt to define roles for N-myc at other stages of development, we have combined the two types of N-myc mutant allele in a compound heterozygote that as a result contains approximately 15% of normal levels of N-Myc protein. Compound heterozygotes died during gestation at a time intermediate to the times of death of embryos homozygous for either mutation individually, and their death appeared to result from cardiac failure stemming from hypoplasia of the compact subepicardial layer of the myocardium. Investigation of the expression pattern of N-myc and various markers of differentiation in wild-type and compound heterozygote mutant hearts has suggested that N-myc may function in maintaining the proliferation and/or preventing the differentiation of compact layer myocytes. This study illustrates the importance of generating different mutations at a given locus to elucidate fully the function of a particular gene during development.


Development ◽  
1995 ◽  
Vol 121 (8) ◽  
pp. 2559-2567 ◽  
Author(s):  
P. Souza ◽  
M. Kuliszewski ◽  
J. Wang ◽  
I. Tseu ◽  
A.K. Tanswell ◽  
...  

The biological role of platelet-derived growth factor (PDGF)-AA in lung morphogenesis was investigated by incubating embryonic lung explants with phosphorothioate antisense PDGF-A oligonucleotides, which decreased PDGF-AA but not PDGF-BB protein content. Antisense PDGF-A oligonucleotides inhibited DNA synthesis. This inhibitory effect of antisense PDGF-A was reversed by the addition of exogenous PDGF-AA but not PDGF-BB. Morphometric analyses of antisense-treated cultures showed a significant reduction in lung size. The number of terminal buds of the lung explants was significantly decreased by antisense PDGF-A oligonucleotides. PDGF-AA but not PDGF-BB attenuated the inhibitory effect of antisense PDGF-A on early lung branching. Sense PDGF-A had no effect on DNA synthesis and early lung branching. Reverse transcriptase-polymerase chain reaction analysis revealed PDGF-A mRNA expression in the epithelial component of the embryonic lung, while message for PDGF alpha-receptor was expressed in the mesenchyme. Incubation of explants with neutralizing PDGF-AA antibodies also reduced DNA synthesis and early branching morphogenesis. We conclude that PDGF-AA and its receptor represent an important epithelial-mesenchymal interaction which plays a critical role in early lung branching morphogenesis.


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