scholarly journals Epithelial Alk3-mediated BMP signaling is essential for mouse lung development in vivo

2007 ◽  
Vol 306 (1) ◽  
pp. 341-342
Author(s):  
Wei Shi ◽  
Jianping Sun ◽  
Hui Chen
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.


Development ◽  
1999 ◽  
Vol 126 (18) ◽  
pp. 4005-4015 ◽  
Author(s):  
M. Weaver ◽  
J.M. Yingling ◽  
N.R. Dunn ◽  
S. Bellusci ◽  
B.L. Hogan

In the mature mouse lung, the proximal-distal (P-D) axis is delineated by two distinct epithelial subpopulations: the proximal bronchiolar epithelium and the distal respiratory epithelium. Little is known about the signaling molecules that pattern the lung along the P-D axis. One candidate is Bone Morphogenetic Protein 4 (Bmp4), which is expressed in a dynamic pattern in the epithelial cells in the tips of growing lung buds. Previous studies in which Bmp4 was overexpressed in the lung endoderm (Bellusci, S., Henderson, R., Winnier, G., Oikawa, T. and Hogan, B. L. M. (1996) Development 122, 1693–1702) suggested that this factor plays an important role in lung morphogenesis. To further investigate this question, two complementary approaches were utilized to inhibit Bmp signaling in vivo. The Bmp antagonist Xnoggin and, independently, a dominant negative Bmp receptor (dnAlk6), were overexpressed using the surfactant protein C (Sp-C) promoter/enhancer. Inhibiting Bmp signaling results in a severe reduction in distal epithelial cell types and a concurrent increase in proximal cell types, as indicated by morphology and expression of marker genes, including the proximally expressed hepatocyte nuclear factor/forkhead homologue 4 (Hfh4) and Clara cell marker CC10, and the distal marker Sp-C. In addition, electron microscopy demonstrates the presence of ciliated cells, a proximal cell type, in the most peripheral regions of the transgenic lungs. We propose a model in which Bmp4 is a component of an apical signaling center controlling P-D patterning. Endodermal cells at the periphery of the lung, which are exposed to high levels of Bmp4, maintain or adopt a distal character, while cells receiving little or no Bmp4 signal initiate a proximal differentiation program.


Author(s):  
Rashika Joshi ◽  
Matthew R. Batie ◽  
Qiang Fan ◽  
Brian Michael Varisco

Most lung development occurs in the context of cyclic stretch. Alteration of the mechanical microenvironment is a common feature of many pulmonary diseases with congenital diaphragmatic hernia (CDH) and fetal tracheal occlusion (FETO, a therapy for CDH) being extreme examples with changes in lung structure, cell differentiation and function. To address limitations in cell culture and in vivo mechanotransductive models we developed two mouse lung organoid (mLO) mechanotransductive models using postnatal day 5 (PND5) mouse lung CD326-positive cells and fibroblasts subjected to increased, decreased, and cyclic strain. In the first model, mLOs were exposed to forskolin (FSK) and/or disrupted (DIS) and evaluated at 20 hours. mLO cross-sectional area changed by +59%, +24% and -68% in FSK, control, and DIS mLOs respectively. FSK-treated organoids had twice as many proliferating cells as other organoids. In the second model, 20 hours of 10.25% biaxial cyclic strain increased the mRNAs of lung mesenchymal cell lineages compared to static stretch and no stretch. Cyclic stretch increased TGF-β and integrin-mediated signaling with upstream analysis indicating roles for histone deacetylases, microRNAs, and long non-coding RNAs. Cyclic stretch mLOs increased αSMA- and αSMA-PDGFRα-double positive cells compared to no stretch and static stretch mLOs. In this PND5 mLO mechanotransductive model, cell proliferation is increased by static stretch, and cyclic stretch induces mesenchymal gene expression changes important in postnatal lung development.


1989 ◽  
Vol 41 (3) ◽  
pp. 223-236 ◽  
Author(s):  
Harold C Slavkin ◽  
Peter Oliver ◽  
Pablo Bringas ◽  
Grace Don-Wheeler ◽  
Mark Mayo ◽  
...  

2010 ◽  
Vol 299 (6) ◽  
pp. R1463-R1477 ◽  
Author(s):  
Jonathan W. Lowery ◽  
Andrea L. Frump ◽  
Lynda Anderson ◽  
Gabriella E. DiCarlo ◽  
Mark T. Jones ◽  
...  

Bone morphogenetic protein (BMP) signaling has been linked to the development of pulmonary hypertension (PH). Inhibitors of differentiation (ID) proteins (ID1–4) are a family of basic helix-loop-helix transcription factors that are downstream targets of the BMP signaling pathway, but the role that ID proteins play in the development of PH is unknown. To address this, we evaluated pulmonary expression of ID proteins in a mouse model of hypoxia-induced PH. There is selective induction of ID1 and ID3 expression in hypoxic pulmonary vascular smooth muscle cells (VSMCs) in vivo, and ID1 and ID3 expression are increased by hypoxia in cultured pulmonary VSMCs in a BMP-dependent fashion. ID4 protein is barely detectable in the mouse lung, and while ID2 is induced in hypoxic peripheral VSMCs in vivo, it is not increased by hypoxia or BMP signaling in cultured pulmonary VSMCs. In addition, the PH response to chronic hypoxia is indistinguishable between wild type and Id1 null mice. This is associated with a compensatory increase in ID3 but not ID2 expression in pulmonary VSMCs of Id1 null mice. These findings indicate that ID1 is dispensable for mounting a normal pulmonary vascular response to hypoxia, but suggest that ID3 may compensate for loss of ID1 expression in pulmonary VSMCs. Taken together, these findings indicate that ID1 and ID3 expression are regulated in a BMP-dependent fashion in hypoxic pulmonary VSMCs, and that ID1 and ID3 may play a cooperative role in regulating BMP-dependent VSMC responses to chronic hypoxia.


2019 ◽  
Vol 20 (10) ◽  
pp. 2500 ◽  
Author(s):  
Vrathasha Vrathasha ◽  
Hilary Weidner ◽  
Anja Nohe

Background: Osteoporosis is a degenerative skeletal disease with a limited number of treatment options. CK2.3, a novel peptide, may be a potential therapeutic. It induces osteogenesis and bone formation in vitro and in vivo by acting downstream of BMPRIA through releasing CK2 from the receptor. However, the detailed signaling pathways, the time frame of signaling, and genes activated remain largely unknown. Methods: Using a newly developed fluorescent CK2.3 analog, specific inhibitors for the BMP signaling pathways, Western blot, and RT-qPCR, we determined the mechanism of CK2.3 in C2C12 cells. We then confirmed the results in primary BMSCs. Results: Using these methods, we showed that CK2.3 stimulation activated OSX, ALP, and OCN. CK2.3 stimulation induced time dependent release of CK2β from BMPRIA and concurrently CK2.3 colocalized with CK2α. Furthermore, CK2.3 induced BMP signaling depends on ERK1/2 and Smad1/5/8 signaling pathways. Conclusion: CK2.3 is a novel peptide that drives osteogenesis, and we detailed the molecular sequence of events that are triggered from the stimulation of CK2.3 until the induction of mineralization. This knowledge can be applied in the development of future therapeutics for osteoporosis.


2016 ◽  
Vol 473 (17) ◽  
pp. 2671-2685 ◽  
Author(s):  
Genta Ito ◽  
Kristina Katsemonova ◽  
Francesca Tonelli ◽  
Pawel Lis ◽  
Marco A.S. Baptista ◽  
...  

Autosomal dominant mutations that activate the leucine-rich repeat kinase 2 (LRRK2) cause inherited Parkinson's disease. Recent work has revealed that LRRK2 directly phosphorylates a conserved threonine/serine residue in the effector-binding switch-II motif of a number of Rab GTPase proteins, including Rab10. Here we describe a facile and robust method to assess phosphorylation of endogenous Rab10 in mouse embryonic fibroblasts (MEFs), lung and spleen-derived B-cells, based on the ability of the Phos-tag reagent to retard the electrophoretic mobility of LRRK2-phosphorylated Rab10. We exploit this assay to show that phosphorylation of Rab10 is ablated in kinase-inactive LRRK2[D2017A] knockin MEFs and mouse lung, demonstrating that LRRK2 is the major Rab10 kinase in these cells/tissue. We also establish that the Phos-tag assay can be deployed to monitor the impact that activating LRRK2 pathogenic (G2019S and R1441G) knockin mutations have on stimulating Rab10 phosphorylation. We show that upon addition of LRRK2 inhibitors, Rab10 is dephosphorylated within 1–2 min, markedly more rapidly than the Ser935 and Ser1292 biomarker sites that require 40–80 min. Furthermore, we find that phosphorylation of Rab10 is suppressed in LRRK2[S910A+S935A] knockin MEFs indicating that phosphorylation of Ser910 and Ser935 and potentially 14-3-3 binding play a role in facilitating the phosphorylation of Rab10 by LRRK2 in vivo. The Rab Phos-tag assay has the potential to significantly aid with evaluating the effect that inhibitors, mutations and other factors have on the LRRK2 signalling pathway.


2012 ◽  
Vol 32 (suppl_1) ◽  
Author(s):  
Thomas Helbing ◽  
Elena Ketterer ◽  
Bianca Engert ◽  
Jennifer Heinke ◽  
Sebastian Grundmann ◽  
...  

Introduction: Acute lung injury (ALI) and its more severe form, acute respiratory distress syndrome, are associated with high morbidity and mortality in patients. During the progression of ALI, the endothelial cell barrier of the pulmonary vasculature becomes compromised, leading to pulmonary edema, a characteristic feature of ALI. It is well-established that EC barrier dysfunction is initiated by cytoskeletal remodeling, which leads to disruption of cell-cell contacts and formation of paracellular gaps, allowing penetration of protein-rich fluid and inflammatory cells. Bone morphogenetic proteins (BMPs) are important players in endothelial dysfunction and inflammation but their effects on endothelial permeability in ALI have not been investigated until now. Methods and Results: As a first approach to assess the role of BMPs in acute lung injury we analysed BMP4 and BMPER expression in an infectious (LPS) and a non-infectious (bleomycin) mouse models of acute lung injury. In both models BMP4 and BMPER protein expression levels were reduced demonstrated by western blots, suggesting that BMPs are involved in progression ALI. To assess the role of BMPs on vascular leakage, a key feature of ALI, BMP activity in mice was inhibited by i.p. administration of LDN193189, a small molecule that blocks BMP signalling. After 3 days Evans blue dye (EVB) was administered i.v. and dye extravasation into the lungs was quantified as a marker for vascular leakage. Interestingly, LDN193189 significantly increased endothelial permeability compared to control lungs, indicating that BMP signaling is involved in maintenance of endothelial barrier function. To quantify effects of BMP inhibition on endothelial barrier function in vitro, HUVECs were seeded onto transwell filters and were exposed to LDN193189. After 3 days FITC-dextrane was added and passage into the lower chamber was quantified as a marker for endothelial barrier function. Thrombin served as a positive control. As expected from our in vivo experiments inhibition of BMP signaling by LDN193189 enhanced FITC-dextrane passage. To study specific effects of BMPs on endothelial barrier function, two protagonist of the BMP family, BMP2 and BMP4, or BMP modulator BMPER were tested in the transwell assay in vitro. Interestingly BMP4 and BMPER, but not BMP2, reduced FITC-dextrane passage demonstrating that BMP4 and BMPER improved endothelial barrier function. Vice versa, specific knock down of BMP4 or BMPER increased leakage in transwell assays. Im immuncytochemistry silencing of BMPER or BMP4 induced hyperpermeability as a consequence of a pro-inflammatory endothelial phenotype characterised by reduced cell-cell contacts and increased actin stress fiber formation. Additionally, the pro-inflammatory endothelial phenotype was confirmed by real-time revealing increased expression of adhesion molecules ICAM-1 or proinflammatory cytokines such as IL-6 and IL-8 in endothelial cells after BMPER or BMP4 knock down. Confirming these in vitro results BMPER +/- mice exhibit increased extravasation of EVB into the lungs, indicating that partial loss of BMPER impairs endothelial barrier function in vitro and in vivo. Conclusion: We identify BMPER and BMP4 as local regulators of vascular permeability. Both are protective for endothelial barrier function and may open new therapeutic avenues in the treatment of acute lung injury.


Sign in / Sign up

Export Citation Format

Share Document