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Hruba E, Kavkova M, Dalecka L, Macholan M, Zikmund T, Varecha M, Bosakova M, Kaiser J, Krejci P, Hovorakova M, Buchtova M. Loss of Sprouty Produces a Ciliopathic Skeletal Phenotype in Mice Through Upregulation of Hedgehog Signaling. J Bone Miner Res 2021; 36:2258-2274. [PMID: 34423857 DOI: 10.1002/jbmr.4427] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 08/13/2021] [Accepted: 08/18/2021] [Indexed: 01/23/2023]
Abstract
The Sprouty family is a highly conserved group of intracellular modulators of receptor tyrosine kinase (RTK)-signaling pathways, which have been recently linked to primary cilia. Disruptions in the structure and function of primary cilia cause inherited disorders called ciliopathies. We aimed to evaluate Sprouty2 and Sprouty4 gene-dependent alterations of ciliary structure and to focus on the determination of its association with Hedgehog signaling defects in chondrocytes. Analysis of the transgenic mice phenotype with Sprouty2 and Sprouty4 deficiency revealed several defects, including improper endochondral bone formation and digit patterning, or craniofacial and dental abnormalities. Moreover, reduced bone thickness and trabecular bone mass, skull deformities, or chondroma-like lesions were revealed. All these pathologies might be attributed to ciliopathies. Elongation of the ciliary axonemes in embryonic and postnatal growth plate chondrocytes was observed in Sprouty2-/- and Sprouty2+/- /Sprouty4-/- mutants compared with corresponding littermate controls. Also, cilia-dependent Hedgehog signaling was upregulated in Sprouty2/4 mutant animals. Ptch1 and Ihh expression were upregulated in the autopodium and the proximal tibia of Sprouty2-/- /Sprouty4-/- mutants. Increased levels of the GLI3 repressor (GLI3R) form were detected in Sprouty2/4 mutant primary fibroblast embryonic cell cultures and tissues. These findings demonstrate that mouse lines deficient in Sprouty proteins manifest phenotypic features resembling ciliopathic phenotypes in multiple aspects and may serve as valuable models to study the association between overactivation of RTK and dysfunction of primary cilia during skeletogenesis. © 2021 American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Eva Hruba
- Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Brno, Czech Republic.,Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Michaela Kavkova
- Central European Institute of Technology, Brno University of Technology, Brno, Czech Republic
| | - Linda Dalecka
- Institute of Histology and Embryology, First Faculty of Medicine, Charles University, Prague, Czech Republic.,Department of Cell Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Miloš Macholan
- Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Brno, Czech Republic
| | - Tomas Zikmund
- Central European Institute of Technology, Brno University of Technology, Brno, Czech Republic
| | - Miroslav Varecha
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Michaela Bosakova
- Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Brno, Czech Republic.,Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Jozef Kaiser
- Central European Institute of Technology, Brno University of Technology, Brno, Czech Republic
| | - Pavel Krejci
- Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Brno, Czech Republic.,Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Maria Hovorakova
- Institute of Histology and Embryology, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Marcela Buchtova
- Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Brno, Czech Republic.,Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
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Adler PN, Wallingford JB. From Planar Cell Polarity to Ciliogenesis and Back: The Curious Tale of the PPE and CPLANE proteins. Trends Cell Biol 2017; 27:379-390. [PMID: 28153580 DOI: 10.1016/j.tcb.2016.12.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 11/28/2016] [Accepted: 12/23/2016] [Indexed: 12/29/2022]
Abstract
Why some genes are more popular than others remains an open question, but one example of this phenomenon involves the genes controlling planar cell polarity (PCP), the polarization of cells within a plane of a tissue. Indeed, the so-called 'core' PCP genes such as dishevelled, frizzled, and prickle have been extensively studied both in animal models and by human genetics. By contrast, other genes that influence PCP signaling have received far less attention. Among the latter are inturned, fuzzy, and fritz, but recent work should bring these once obscure regulators into the limelight. We provide here a brief history of planar polarity effector (PPE) and CPLANE (ciliogenesis and planar polarity effector) proteins, discuss recent advances in understanding their molecular mechanisms of action, and describe their roles in human disease.
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Affiliation(s)
- Paul N Adler
- Departments of Biology and Cell Biology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - John B Wallingford
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA.
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Tabler JM, Rice CP, Liu KJ, Wallingford JB. A novel ciliopathic skull defect arising from excess neural crest. Dev Biol 2016; 417:4-10. [PMID: 27395007 DOI: 10.1016/j.ydbio.2016.07.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 07/01/2016] [Indexed: 01/17/2023]
Abstract
The skull is essential for protecting the brain from damage, and birth defects involving disorganization of skull bones are common. However, the developmental trajectories and molecular etiologies by which many craniofacial phenotypes arise remain poorly understood. Here, we report a novel skull defect in ciliopathic Fuz mutant mice in which only a single bone pair encases the forebrain, instead of the usual paired frontal and parietal bones. Through genetic lineage analysis, we show that this defect stems from a massive expansion of the neural crest-derived frontal bone. This expansion occurs at the expense of the mesodermally-derived parietal bones, which are either severely reduced or absent. A similar, though less severe, phenotype was observed in Gli3 mutant mice, consistent with a role for Gli3 in cilia-mediated signaling. Excess crest has also been shown to drive defective palate morphogenesis in ciliopathic mice, and that defect is ameliorated by reduction of Fgf8 gene dosage. Strikingly, skull defects in Fuz mutant mice are also rescued by loss of one allele of fgf8, suggesting a potential route to therapy. In sum, this work is significant for revealing a novel skull defect with a previously un-described developmental etiology and for suggesting a common developmental origin for skull and palate defects in ciliopathies.
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Affiliation(s)
- Jacqueline M Tabler
- Department of Molecular Biosciences, University of Texas at Austin, United States
| | - Christopher P Rice
- Department of Molecular Biosciences, University of Texas at Austin, United States
| | - Karen J Liu
- Department of Craniofacial Development and Stem Cell Biology, King's College London, UK.
| | - John B Wallingford
- Department of Molecular Biosciences, University of Texas at Austin, United States.
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