Involvement of Sonic hedgehog (Shh) in mouse embryonic lung growth and morphogenesis

Development ◽  
1997 ◽  
Vol 124 (1) ◽  
pp. 53-63 ◽  
Author(s):  
S. Bellusci ◽  
Y. Furuta ◽  
M.G. Rush ◽  
R. Henderson ◽  
G. Winnier ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Sonic Hedgehog ◽  
Transmembrane Protein ◽  
Mesenchymal Cell ◽  
Branching Morphogenesis ◽  
Significant Inhibition ◽  
Mouse Lung ◽  
Embryonic Lung ◽  
Newborn Mice

Branching morphogenesis of the embryonic lung requires interactions between the epithelium and the mesenchyme. Previously, we reported that Sonic hedgehog (Shh) transcripts are present in the epithelium of the developing mouse lung, with highest levels in the terminal buds. Here, we report that transcripts of mouse patched (Ptc), the homologue of a Drosophila gene encoding a putative transmembrane protein required for hedgehog signaling, are expressed at high levels in the mesenchyme adjacent to the end buds. To investigate the function of SHH in lung development, Shh was overexpressed throughout the distal epithelium, using the surfactant protein-C (SP-C)-enhancer/promoter. Beginning around 16.5 dpc, when Shh and Ptc RNA levels are normally both declining, this treatment caused an increase in the ratio of interstitial mesenchyme to epithelial tubules in transgenic compared to normal lungs. Transgenic newborn mice die soon after birth. Histological analysis of the lungs at the light and electron microscope level shows an abundance of mesenchyme and the absence of typical alveoli. In vivo BrdU labeling indicates that Shh overexpression results in increased mesenchymal and epithelial cell proliferation at 16.5 and 17.5 dpc. However, analysis of CC-10 and SP-C expression reveals no significant inhibition in the differentiation of proximal and distal epithelial cells. The expression of genes potentially regulated by SHH was also examined. No difference could be observed between transgenic and control lungs in either the level or distribution of Bmp4, Wnt2 and Fgf7 RNA. By contrast, Ptc is clearly upregulated in the transgenic lung. These results thus establish a role for SHH in lung morphogenesis, and suggest that SHH normally regulates lung mesenchymal cell proliferation in vivo.

scholarly journals Cleavage activates Dispatched for Sonic Hedgehog ligand release

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Daniel P Stewart ◽  
Suresh Marada ◽  
William J Bodeen ◽  
Ashley Truong ◽  
Sadie Miki Sakurada ◽  
...  
Keyword(s):  
Sonic Hedgehog ◽  
Membrane Trafficking ◽  
Developmental Disorders ◽  
Transmembrane Protein ◽  
Regulatory Mechanisms ◽  
Extracellular Loop ◽  
Site Mutation ◽  
Evolutionarily Conserved ◽  
Processing Site

Hedgehog ligands activate an evolutionarily conserved signaling pathway that provides instructional cues during tissue morphogenesis, and when corrupted, contributes to developmental disorders and cancer. The transmembrane protein Dispatched is an essential component of the machinery that deploys Hedgehog family ligands from producing cells, and is absolutely required for signaling to long-range targets. Despite this crucial role, regulatory mechanisms controlling Dispatched activity remain largely undefined. Herein, we reveal vertebrate Dispatched is activated by proprotein convertase-mediated cleavage at a conserved processing site in its first extracellular loop. Dispatched processing occurs at the cell surface to instruct its membrane re-localization in polarized epithelial cells. Cleavage site mutation alters Dispatched membrane trafficking and reduces ligand release, leading to compromised pathway activity in vivo. As such, convertase-mediated cleavage is required for Dispatched maturation and functional competency in Hedgehog ligand-producing cells.

Abrogation of mesenchyme-specific TGF-β signaling results in lung malformation with prenatal pulmonary cysts in mice

2021 ◽  
Author(s):  
Qing Miao ◽  
Hui Chen ◽  
Yongfeng Luo ◽  
Joanne Chiu ◽  
Ling Chu ◽  
...  
Keyword(s):  
Lung Development ◽  
Muscle Growth ◽  
Branching Morphogenesis ◽  
Mouse Lung ◽  
Cystic Lesions ◽  
Alveolar Epithelial ◽  
Pulmonary Cysts ◽  
Β Receptor ◽  
Airway Branching

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.

scholarly journals ORMDL1 is upregulated and associated with favorable outcome in colorectal cancer

2020 ◽  
Author(s):  
Qian Wang ◽  
Wanjun Liu ◽  
Si Chen ◽  
Qianxin Luo ◽  
Yichen Li ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cell Proliferation ◽  
Colony Formation ◽  
Transmembrane Protein ◽  
Cohort Analysis ◽  
Negative Regulator ◽  
Morphologic Change ◽  
Mesenchymal Transition

AbstractBackgroundORMDL1 gene encodes a transmembrane protein for endoplasmic reticulum and is known as crucial negative regulator for sphingolipid biogenesis. However, it has been rarely studied in tumor-related context. Therefore, its prognostic value and functional significance in colorectal cancer (CRC) remain to be explored.MethodsTCGA CRC cohort analysis, qRT-PCR, and immunohistochemistry (IHC) were used to examine the ORMDL1 expression level. The association between ORMDL1 expression and various clinical characteristics were analyzed by Chi-square tests. CRC patients’ overall survival (OS) was analyzed by Kaplan-Meier analysis. In vitro and in vivo cell-based assays were performed to explore the role of ORMDL1 in cell proliferation, invasion and migration. Transcriptional changes of cells either with ORMDL1 knockdowned or overexpressed were compared and analyzed.ResultsORMDL1 was upregulated in CRC tissues either in TCGA cohort or in our cohort. Interestingly, its expression was significantly lower in patients with metastasis compared to patients without metastasis, and high expression group had longer OS than low expression group. Knockdown of ORMDL1 expression can promote proliferation, colony formation and invasion, while attenuate migration in CRC cell lines. In opposite, forced overexpression of ORMDL1 reduced cell proliferation, colony formation and invasion, while enhanced cell migration. Epithelial-to-mesenchymal transition (EMT) related genes were enriched among differentially expressed genes when ORMDL1 was knockdowned in cells, which was consistent with morphologic change by microscopy observation. Finally, stable knockdown of ORMDL1 can promote cancer cell proliferation in vivo to some extent.ConclusionORMDL1 is upregulated and may serve as biomarker to predict favourable outcome in colorectal cancer.

scholarly journals Retinoic acid decreases fetal lung mesenchymal cell proliferation in vivo and in vitro

2004 ◽  
Vol 46 (3) ◽  
pp. 275-282 ◽  
Author(s):  
Sussie Dalvin ◽  
Katsumi Komatsuzaki ◽  
Mark A. Anselmo ◽  
David E. Kling ◽  
Jay J. Schnitzer ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Retinoic Acid ◽  
Mesenchymal Cell ◽  
Fetal Lung

scholarly journals Rac1 modulates mammalian lung branching morphogenesis in part through canonical Wnt signaling

2016 ◽  
Vol 311 (6) ◽  
pp. L1036-L1049 ◽  
Author(s):  
Soula Danopoulos ◽  
Michael Krainock ◽  
Omar Toubat ◽  
Matthew Thornton ◽  
Brendan Grubbs ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Wnt Signaling ◽  
Branching Morphogenesis ◽  
Mouse Lung ◽  
Canonical Wnt Signaling ◽  
Embryonic Mouse ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation ◽  
Canonical Wnt ◽  
Lung Branching

Lung branching morphogenesis relies on a number of factors, including proper epithelial cell proliferation and differentiation, cell polarity, and migration. Rac1, a small Rho GTPase, orchestrates a number of these cellular processes, including cell proliferation and differentiation, cellular alignment, and polarization. Furthermore, Rac1 modulates both noncanonical and canonical Wnt signaling, important pathways in lung branching morphogenesis. Culture of embryonic mouse lung explants in the presence of the Rac1 inhibitor (NSC23766) resulted in a dose-dependent decrease in branching. Increased cell death and BrdU uptake were notably seen in the mesenchyme, while no direct effect on the epithelium was observed. Moreover, vasculogenesis was impaired following Rac1 inhibition as shown by decreased Vegfa expression and impaired LacZ staining in Flk1-Lacz reporter mice. Rac1 inhibition decreased Fgf10 expression in conjunction with many of its associated factors. Moreover, using the reporter lines TOPGAL and Axin2-LacZ, there was an evident decrease in canonical Wnt signaling in the explants treated with the Rac1 inhibitor. Activation of canonical Wnt pathway using WNT3a or WNT7b only partially rescued the branching inhibition. Moreover, these results were validated on human explants, where Rac1 inhibition resulted in impaired branching and decreased AXIN2 and FGFR2b expression. We therefore conclude that Rac1 regulates lung branching morphogenesis, in part through canonical Wnt signaling. However, the exact mechanisms by which Rac1 interacts with canonical Wnt in human and mouse lung requires further investigation.

scholarly journals Angiotensin II AT2 receptor regulates ureteric bud morphogenesis

2010 ◽  
Vol 298 (3) ◽  
pp. F807-F817 ◽  
Author(s):  
Renfang Song ◽  
Melissa Spera ◽  
Colleen Garrett ◽  
Samir S. El-Dahr ◽  
Ihor V. Yosypiv
Keyword(s):  
Cell Proliferation ◽  
Signaling Pathway ◽  
Ex Vivo ◽  
Branching Morphogenesis ◽  
Mrna Levels ◽  
Ureteric Bud ◽  
Embryonic Mouse ◽  
Genetic Inactivation ◽  
The Impact

ANG II AT2 receptor (AT2R)-deficient mice exhibit abnormal ureteric bud (UB) budding, increased incidence of double ureters, and vesicoureteral reflux. However, the role of the AT2R during UB morphogenesis and the mechanisms by which aberrant AT2R signaling disrupts renal collecting system development have not been fully defined. In this study, we mapped the expression of the AT2R during mouse metanephric development, examined the impact of disrupted AT2R signaling on UB branching, cell proliferation, and survival, and investigated the cross talk of the AT2R with the glial-derived neurotrophic factor ( GDNF)/ c-Ret/Wnt11 signaling pathway. Embryonic mouse kidneys express AT2R in the branching UB and the mesenchyme. Treatment of embryonic day 12.5 ( E12.5) metanephroi with the AT2R antagonist PD123319 or genetic inactivation of the AT2R in mice inhibits UB branching, decreasing the number of UB tips compared with control (34 ± 1.0 vs. 43 ± 0.6, P < 0.01; 36 ± 1.8 vs. 48 ± 1.3, P < 0.01, respectively). In contrast, treatment of metanephroi with the AT2R agonist CGP42112 increases the number of UB tips compared with control (48 ± 1.8 vs. 39 ± 12.3, P < 0.05). Using real-time quantitative RT-PCR and whole mount in situ hybridization, we demonstrate that PD123319 downregulates the expression of GDNF, c-Ret, Wnt11, and Spry1 mRNA levels in E12.5 metanephroi grown ex vivo. AT2R blockade or genetic inactivation of AT2R stimulates apoptosis and inhibits proliferation of the UB cells in vivo. We conclude that AT2R performs essential functions during UB branching morphogenesis via control of the GDNF/c-Ret/Wnt11 signaling pathway, UB cell proliferation, and survival.

scholarly journals Long Noncoding RNA SNHG4 Remits Lipopolysaccharide‐Engendered Inflammatory Lung Damage by Inhibiting METTL3 - Mediated m6A Level of STAT2 mRNA

2021 ◽  
Author(s):  
Si-Xiu Li ◽  
Wen Yan ◽  
Jian-Ping Liu ◽  
Yu-Juan Zhao ◽  
Lu Chen
Keyword(s):  
Cell Proliferation ◽  
Noncoding Rna ◽  
Lung Damage ◽  
Lung Fibroblasts ◽  
Mouse Lung ◽  
Treated Cell ◽  
Cell Functions ◽  
Tnf Α

Abstract Background: Emerging evidence suggests that long non coding RNA (lncRNA) small nucleolar RNA host gene 4 (SNHG4) has become a new insight into lipopolysaccharide (LPS) - induced microglia inflammation, its role in neonatal pneumonia (NP) remains to be largely unrevealed.Methods: RT-qPCR was used to determine SNHG4 and METTL3 expression in the serum from NP patients and normal volunteers, as well as in WI-38 cells treated with LPS. The SNHG4 overexpression vector (pcDNA-SNHG4) was transfected into LPS - treated cells. CCK-8, Transwell, annexin V-FITC/PI and ELISA assays were used to determine cell proliferation, migration, apoptosis and contents of IL-6, TNF-α, SOD and MDA, respectively. The level of SNHG4 in the promoter region of METTL3 was assessed with RIP assay. m6A quantitative analysis illustrated the m6A level with or without SNHG4 overexpression or METTL3 silencing. Bioinformatics analysis and RIP-PCR were used to predict and validate YTHDF1 - mediated m6A levels on signal transducer and activator of transcription 2 (STAT2) mRNA in METTL3 inhibited cells. Then rescue experiments were performed to explore effects of SNHG4 and METTL3 or STAT2 on LPS-treated cell functions. Subsequently, in vivo functional experiments were performed to investigate the role of SNHG4 in LPS induced pneumonia in mice. Results: SNHG4 was downregulated and METTL3 was upregulated in NP patients and LPS-treated cells. SNHG4 overexpression facilitated cell proliferation, migration and SOD concentration, and inhibited apoptosis and IL-6, TNF-α and MDA contents. Mechanistically, SNHG4 bound with METTL3 and downregulated METTL3 expression. Besides, total m6A modification level was lower in the SNHG4 overexpressed or METTL3 inhibited cells. METTL3 interference reduced m6A levels of STAT2 mRNA, decreased STAT2 mRNA stability and promoted STAT2 translation level. METTL3 or STAT2 upregulated reversed the effects of SNHG4 overexpression on LPS - treated cell functions. Conclusions: This study reveals that SNHG4 promotes LPS induced inflammation in human lung fibroblasts and mouse lung tissues in vitro and in vivo by inhibiting METTL3 - mediated m6A level of STAT2 mRNA, which may provide a potential therapeutic mechanism for NP.

scholarly journals CircSEC24A promotes colorectal cancer progression by regulating miR-488-3p/TMEM106B axis

2020 ◽  
Author(s):  
Gaowu Hu ◽  
Wei Peng ◽  
Yongqing Cao
Keyword(s):  
Colorectal Cancer ◽  
Cell Cycle ◽  
Cell Proliferation ◽  
Transmembrane Protein ◽  
Xenograft Model ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Circular Rnas ◽  
Cell Progression

Abstract Background: Currently, more and more circular RNAs (circRNAs) have been identified to exert their functions in tumor progression, including colorectal cancer (CRC). However, the role of circSEC24A (circ_0003528) in CRC remains unknown.Methods: Quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to determine the levels of circSEC24A, SEC24A and microRNA-488-3p (miR-488-3p). The characterization of circSEC24A was investigated by Actinomycin D and RNase R digestion assays. 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT) assay was used to assess cell proliferation. Flow cytometry analysis was adopted for cell apoptosis and cell cycle process. Transwell assay was employed to evaluate cell migration and invasion. Western blot assay was performed to determine protein levels. Dual-luciferase reporter assay was utilized to explore the relationship between miR-488-3p and circSEC24A or transmembrane protein 106B (TMEM106B). Murine xenograft model was constructed to explore the effect of circSEC24A in vivo .Results: CircSEC24A level was increased in CRC tissues and cells. CircSEC24A deficiency impeded cell proliferation, cell cycle process, migration and invasion and induced apoptosis in CRC cells in vitro and blocked tumorigenesis in vivo . MiR-488-3p was a target of circSEC24A and miR-488-3p was downregulated in CRC tissues and cells. The inhibitory effect of circSEC24A silencing on CRC cell progression was restored by miR-488-3p inhibition. Moreover, TMEM106B could be negatively regulated by miR-488-3p via acting as a downstream gene of miR-488-3p. MiR-488-3p overexpression decelerated CRC cell progression by targeting TMEM106B.Conclusion: CircSEC24A facilitated CRC progression by regulating miR-488-3p/TMEM106B axis, which might provide a promising treatment approach for CRC.

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