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Pitirri MK, Richtsmeier JT, Kawasaki M, Coupe AP, Perrine SM, Kawasaki K. Come together over me: Cells that form the dermatocranium and chondrocranium in mice. Anat Rec (Hoboken) 2023:10.1002/ar.25295. [PMID: 37497849 PMCID: PMC10818014 DOI: 10.1002/ar.25295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 06/30/2023] [Accepted: 07/03/2023] [Indexed: 07/28/2023]
Abstract
Most bone develops either by intramembranous ossification where bone forms within a soft connective tissue, or by endochondral ossification by way of a cartilage anlagen or model. Bones of the skull can form endochondrally or intramembranously or represent a combination of the two types of ossification. Contrary to the classical definition of intramembranous ossification, we have previously described a tight temporo-spatial relationship between cranial cartilages and dermal bone formation and proposed a mechanistic relationship between chondrocranial cartilage and dermal bone. Here, we further investigate this relationship through an analysis of how cells organize to form cranial cartilages and dermal bone. Using Wnt1-Cre2 and Mesp1-Cre transgenic mice, we determine the derivation of cells that comprise cranial cartilages from either cranial neural crest (CNC) or paraxial mesoderm (PM). We confirm a previously determined CNC-PM boundary that runs through the hypophyseal fenestra in the cartilaginous braincase floor and identify four additional CNC-PM boundaries in the chondrocranial lateral wall, including a boundary that runs along the basal and apical ends of the hypochiasmatic cartilage. Based on the knowledge that as osteoblasts differentiate from CNC- and PM-derived mesenchyme, the differentiating cells express the transcription factor genes RUNX2 and osterix (OSX), we created a new transgenic mouse line called R2Tom. R2Tom mice carry a tdTomato reporter gene joined with an evolutionarily well-conserved enhancer sequence of RUNX2. R2Tom mice crossed with Osx-GFP mice yield R2Tom;Osx-GFP double transgenic mice in which various stages of osteoblasts and their precursors are detected with different fluorescent reporters. We use the R2Tom;Osx-GFP mice, new data on the cell derivation of cranial cartilages, histology, immunohistochemistry, and detailed morphological observations combined with data from other investigators to summarize the differentiation of cranial mesenchyme as it forms condensations that become chondrocranial cartilages and associated dermal bones of the lateral cranial wall. These data advance our previous findings of a tendency of cranial cartilage and dermal bone development to vary jointly in a coordinated manner, promoting a role for cranial cartilages in intramembranous bone formation.
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Affiliation(s)
- M Kathleen Pitirri
- Department of Anthropology, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Joan T Richtsmeier
- Department of Anthropology, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Mizuho Kawasaki
- Department of Anthropology, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Abigail P Coupe
- Department of Anthropology, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Susan Motch Perrine
- Department of Anthropology, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Kazuhiko Kawasaki
- Department of Anthropology, The Pennsylvania State University, University Park, Pennsylvania, USA
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2
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Galea GL, Zein MR, Allen S, Francis-West P. Making and shaping endochondral and intramembranous bones. Dev Dyn 2020; 250:414-449. [PMID: 33314394 PMCID: PMC7986209 DOI: 10.1002/dvdy.278] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 11/13/2020] [Accepted: 11/20/2020] [Indexed: 12/13/2022] Open
Abstract
Skeletal elements have a diverse range of shapes and sizes specialized to their various roles including protecting internal organs, locomotion, feeding, hearing, and vocalization. The precise positioning, size, and shape of skeletal elements is therefore critical for their function. During embryonic development, bone forms by endochondral or intramembranous ossification and can arise from the paraxial and lateral plate mesoderm or neural crest. This review describes inductive mechanisms to position and pattern bones within the developing embryo, compares and contrasts the intrinsic vs extrinsic mechanisms of endochondral and intramembranous skeletal development, and details known cellular processes that precisely determine skeletal shape and size. Key cellular mechanisms are employed at distinct stages of ossification, many of which occur in response to mechanical cues (eg, joint formation) or preempting future load‐bearing requirements. Rapid shape changes occur during cellular condensation and template establishment. Specialized cellular behaviors, such as chondrocyte hypertrophy in endochondral bone and secondary cartilage on intramembranous bones, also dramatically change template shape. Once ossification is complete, bone shape undergoes functional adaptation through (re)modeling. We also highlight how alterations in these cellular processes contribute to evolutionary change and how differences in the embryonic origin of bones can influence postnatal bone repair. Compares and contrasts Endochondral and intramembranous bone development Reviews embryonic origins of different bones Describes the cellular and molecular mechanisms of positioning skeletal elements. Describes mechanisms of skeletal growth with a focus on the generation of skeletal shape
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Affiliation(s)
- Gabriel L Galea
- Developmental Biology and Cancer, UCL GOS Institute of Child Health, London, UK.,Comparative Bioveterinary Sciences, Royal Veterinary College, London, UK
| | - Mohamed R Zein
- Centre for Craniofacial and Regenerative Biology, Faculty of Dentistry, Oral and Craniofacial Sciences, King's College London, London, UK
| | - Steven Allen
- Comparative Bioveterinary Sciences, Royal Veterinary College, London, UK
| | - Philippa Francis-West
- Centre for Craniofacial and Regenerative Biology, Faculty of Dentistry, Oral and Craniofacial Sciences, King's College London, London, UK
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3
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Periconception maternal low-protein diet adversely affects male mouse fetal bone growth and mineral density quality in late gestation. J Dev Orig Health Dis 2020; 12:384-395. [PMID: 32500846 DOI: 10.1017/s204017442000046x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Adverse programming of adult non-communicable disease can be induced by poor maternal nutrition during pregnancy and the periconception period has been identified as a vulnerable period. In the current study, we used a mouse maternal low-protein diet fed either for the duration of pregnancy (LPD) or exclusively during the preimplantation period (Emb-LPD) with control nutrition provided thereafter and postnatally to investigate effects on fetal bone development and quality. This model has been shown previously to induce cardiometabolic and neurological disease phenotypes in offspring. Micro 3D computed tomography examination at fetal stages Embryonic day E14.5 and E17.4, reflecting early and late stages of bone formation, demonstrated LPD treatment caused increased bone formation of relative high mineral density quality in males, but not females, at E14.5, disproportionate to fetal growth, with bone quality maintained at E17.5. In contrast, Emb-LPD caused a late increase in male fetal bone growth, proportionate to fetal growth, at E17.5, affecting central and peripheral skeleton and of reduced mineral density quality relative to controls. These altered dynamics in bone growth coincide with increased placental efficiency indicating compensatory responses to dietary treatments. Overall, our data show fetal bone formation and mineral quality is dependent upon maternal nutritional protein content and is sex-specific. In particular, we find the duration and timing of poor maternal diet to be critical in the outcomes with periconceptional protein restriction leading to male offspring with increased bone growth but of poor mineral density, thereby susceptible to later disease risk.
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4
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Qin X, Jiang Q, Miyazaki T, Komori T. Runx2 regulates cranial suture closure by inducing hedgehog, Fgf, Wnt and Pthlh signaling pathway gene expressions in suture mesenchymal cells. Hum Mol Genet 2020; 28:896-911. [PMID: 30445456 DOI: 10.1093/hmg/ddy386] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 10/25/2018] [Accepted: 11/02/2018] [Indexed: 12/23/2022] Open
Abstract
Cleidocranial dysplasia (CCD, #119600), which is characterized by hypoplastic clavicles, open fontanelles, supernumerary teeth and a short stature, is caused by heterozygous mutations in RUNX2. However, it currently remains unclear why suture closure is severely impaired in CCD patients. The closure of posterior frontal (PF) and sagittal (SAG) sutures was completely interrupted in Runx2+/- mice, and the proliferation of suture mesenchymal cells and their condensation were less than those in wild-type mice. To elucidate the underlying molecular mechanisms, differentially expressed genes between wild-type and Runx2+/- PF and SAG sutures were identified by microarray and real-time reverse transcription polymerase chain reaction analyses. The expression of hedgehog, Fgf, Wnt and Pthlh signaling pathway genes, including Gli1, Ptch1, Ihh, Fgfr2, Fgfr3, Tcf7, Wnt10b and Pth1r, which were directly regulated by Runx2, was reduced in the sutures, but not the calvarial bone tissues of Runx2+/- mice. Bone formation and suture closure were enhanced in an organ culture of Runx2+/- calvariae with ligands or agonists of hedgehog, Fgf, Wnt and Pthlh signaling, while they were suppressed and suture mesenchymal cell proliferation was decreased in an organ culture of wild-type calvariae with their antagonists. These results indicate that more than a half dosage of Runx2 is required for the proliferation of suture mesenchymal cells, their condensation and commitment to osteoblast-lineage cells, and the induction of hedgehog, Fgf, Wnt and Pthlh signaling pathway gene expressions in sutures, but not in calvarial bone tissues, and also that the activation of hedgehog, Fgf, Wnt and Pthlh signaling pathways is necessary for suture closure.
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Affiliation(s)
- Xin Qin
- Department of Cell Biology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Qing Jiang
- Department of Cell Biology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.,Basic and Translational Research Center for Hard Tissue Disease, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Toshihiro Miyazaki
- Department of Cell Biology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Toshihisa Komori
- Department of Cell Biology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.,Basic and Translational Research Center for Hard Tissue Disease, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
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5
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Komori T. Molecular Mechanism of Runx2-Dependent Bone Development. Mol Cells 2020; 43:168-175. [PMID: 31896233 PMCID: PMC7057844 DOI: 10.14348/molcells.2019.0244] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Accepted: 12/03/2019] [Indexed: 01/09/2023] Open
Abstract
Runx2 is an essential transcription factor for skeletal development. It is expressed in multipotent mesenchymal cells, osteoblast-lineage cells, and chondrocytes. Runx2 plays a major role in chondrocyte maturation, and Runx3 is partly involved. Runx2 regulates chondrocyte proliferation by directly regulating Ihh expression. It also determines whether chondrocytes become those that form transient cartilage or permanent cartilage, and functions in the pathogenesis of osteoarthritis. Runx2 is essential for osteoblast differentiation and is required for the proliferation of osteoprogenitors. Ihh is required for Runx2 expression in osteoprogenitors, and hedgehog signaling and Runx2 induce the differentiation of osteoprogenitors to preosteoblasts in endochondral bone. Runx2 induces Sp7 expression, and Runx2, Sp7, and canonical Wnt signaling are required for the differentiation of preosteoblasts to immature osteoblasts. It also induces the proliferation of osteoprogenitors by directly regulating the expression of Fgfr2 and Fgfr3. Furthermore, Runx2 induces the proliferation of mesenchymal cells and their commitment into osteoblast-lineage cells through the induction of hedgehog (Gli1, Ptch1, Ihh), Fgf (Fgfr2, Fgfr3), Wnt (Tcf7, Wnt10b), and Pthlh (Pth1r) signaling pathway gene expression in calvaria, and more than a half-dosage of Runx2 is required for their expression. This is a major cause of cleidocranial dysplasia, which is caused by heterozygous mutation of RUNX2. Cbfb, which is a co-transcription factor that forms a heterodimer with Runx2, enhances DNA binding of Runx2 and stabilizes Runx2 protein by inhibiting its ubiquitination. Thus, Runx2/Cbfb regulates the proliferation and differentiation of chondrocytes and osteoblast-lineage cells by activating multiple signaling pathways and via their reciprocal regulation.
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Affiliation(s)
- Toshihisa Komori
- Basic and Translational Research Center for Hard Tissue Disease, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8588, Japan
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6
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Souza Junior P, Viotto‐Souza W, Mendes VP, Bernardes FCS, Anjos BL, Abidu‐Figueiredo M, Santos ALQ. Clavicle in Carnivorans: A Forgotten Bone. Anat Rec (Hoboken) 2019; 303:1831-1841. [DOI: 10.1002/ar.24294] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 09/04/2019] [Accepted: 09/07/2019] [Indexed: 11/06/2022]
Affiliation(s)
- Paulo Souza Junior
- Laboratory of Animal AnatomyFederal University of Pampa (UNIPAMPA) Uruguaiana RS Brazil
| | - Wilson Viotto‐Souza
- Laboratory of Wild Animals Teaching and ResearchFederal University of Uberlândia (UFU) Uberlândia MG Brazil
- Laboratory of Animal AnatomyPresidente Antonio Carlos University (UNIPAC) Uberlândia RS Brazil
| | - Vanessa Pereira Mendes
- Laboratory of Veterinary PathologyFederal University of Pampa (UNIPAMPA) Uruguaiana RS Brazil
| | | | - Bruno Leite Anjos
- Laboratory of Veterinary PathologyFederal University of Pampa (UNIPAMPA) Uruguaiana RS Brazil
| | - Marcelo Abidu‐Figueiredo
- Department of Animal Biology, Animal Anatomy AreaFederal Rural University of Rio de Janeiro (UFRRJ) Seropédica RJ Brazil
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Mitomo K, Matsunaga S, Kitamura K, Nakamura T, Saito A, Komori T, Muramatsu T, Yamaguchi A. Sphenoid bone hypoplasia is a skeletal phenotype of cleidocranial dysplasia in a mouse model and patients. Bone 2019; 120:176-186. [PMID: 30391578 DOI: 10.1016/j.bone.2018.10.028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 10/31/2018] [Accepted: 10/31/2018] [Indexed: 11/24/2022]
Abstract
Cleidocranial dysplasia (CCD) is an autosomal dominant disorder caused by heterozygous mutations in RUNX2. Affected individuals exhibit delayed maturation or hypoplasia in various bones, mainly including those formed by intramembranous ossification. Although several reports described deformation of the sphenoid bone in CCD patients, details of the associated changes have not been well documented. Most parts of the sphenoid bone are formed by endochondral ossification; however, the medial pterygoid process is formed by intramembranous ossification associated with secondary cartilage. We first investigated histological changes in the medial pterygoid process during different developmental stages in Runx2+/+ and Runx2+/- mice, finding that mesenchymal cell condensation of the anlage of this structure was delayed in Runx2+/- mice as compared with that in Runx2+/+ mice. Additionally, in Runx2+/+ mice, Osterix-positive osteoblastic cells appeared at the upper region of the anlage of the medial pterygoid process, and bone trabeculae appeared to associate with subsequent secondary cartilage formation. By contrast, few Osterix-positive osteoblastic cells appeared at the upper region of the anlage of the medial pterygoid process, and no bone trabeculae appeared thereafter in Runx2+/- mice. At more advanced embryonic stages, endochondral ossification occurred at the lower part of the medial pterygoid process in both Runx2+/+ and Runx2+/- mice. After birth, well-developed bone trabeculae occupied two-thirds of the cranial side of the medial pterygoid process, and cartilage appeared beneath these bones in Runx2+/+ mice, whereas thin trabecular bone appeared at the center of the cartilage of the medial pterygoid process in Runx2+/- mice. In adult mice, the body and medial pterygoid processes of the sphenoid bone comprised mature bones in both Runx2+/+ and Runx2+/- mice, although the axial length of the medial pterygoid processes was apparently lower in Runx2+/-mice as compared with that in Runx2+/+mice based on histological and micro-computed tomography (CT) examinations. Moreover, medical-CT examination revealed that in CCD patients, the medial pterygoid process of sphenoid bone was significantly shorter relative to that in healthy young adults. These results demonstrated that the medial pterygoid process of the sphenoid bone specifically exhibited hypoplasia in CCD.
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Affiliation(s)
- Keisuke Mitomo
- Department of Operative Dentistry, Cariology and Dental Pulp Biology, Tokyo Dental College, Tokyo, Japan; Tokyo Dental College Research Branding Project, Tokyo Dental College, Tokyo, Japan
| | - Satoru Matsunaga
- Tokyo Dental College Research Branding Project, Tokyo Dental College, Tokyo, Japan; Department of Anatomy, Tokyo Dental College, Tokyo, Japan; Oral Health Science Center, Tokyo Dental College, Tokyo, Japan
| | - Kei Kitamura
- Tokyo Dental College Research Branding Project, Tokyo Dental College, Tokyo, Japan; Department of Histology, Tokyo Dental College, Tokyo, Japan
| | - Takashi Nakamura
- Tokyo Dental College Research Branding Project, Tokyo Dental College, Tokyo, Japan; Department of Biochemistry, Tokyo Dental College, Tokyo, Japan
| | - Akiko Saito
- Department of Biochemistry, Tokyo Dental College, Tokyo, Japan
| | - Toshihisa Komori
- Department of Cell Biology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Takashi Muramatsu
- Department of Operative Dentistry, Cariology and Dental Pulp Biology, Tokyo Dental College, Tokyo, Japan; Tokyo Dental College Research Branding Project, Tokyo Dental College, Tokyo, Japan; Oral Health Science Center, Tokyo Dental College, Tokyo, Japan
| | - Akira Yamaguchi
- Tokyo Dental College Research Branding Project, Tokyo Dental College, Tokyo, Japan; Oral Health Science Center, Tokyo Dental College, Tokyo, Japan.
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8
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Gharibi B, Ghuman MS, Cama G, Rawlinson SCF, Grigoriadis AE, Hughes FJ. Site-specific differences in osteoblast phenotype, mechanical loading response and estrogen receptor-related gene expression. Mol Cell Endocrinol 2018; 477:140-147. [PMID: 29928929 DOI: 10.1016/j.mce.2018.06.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2017] [Revised: 05/08/2018] [Accepted: 06/16/2018] [Indexed: 12/23/2022]
Abstract
The osteoporosis-resistant nature of skull bones implies inherent differences exist between their cellular responses and those of other osteoporosis-susceptible skeletal sites. Phenotypic differences in calvarial and femoral osteoblastic responses to induction of osteogenesis, mechanical loading, estrogen, growth factor and cytokine stimulation were investigated. Primary rat calvarial and femoral adult male osteoblasts were cultured and osteoblastic mineralisation and maturation determined using Alizarin Red staining and expression of osteogenic marker genes assessed. Expression of known mechanically-responsive genes was compared between sites following loading of scaffold-seeded cells in a bioreactor. Cell proliferation and differentiation following growth factor and estrogen stimulation were also compared. Finally expression of estrogen receptors and associated genes during osteogenic differentiation were investigated. Calvarial osteoblasts exhibited delayed maturation (45d. vs 21d.) and produced less mineralised matrix than femoral osteoblasts when osteogenically induced. PDGF-BB and FGF2 both caused a selective increase in proliferation and decrease in osteoblastic differentiation of femoral osteoblasts. Mechanical stimulation resulted in the induction of the expression of Ccl2 and Anx2a selectively in femoral osteoblasts, but remained unchanged in calvarial cells. Estrogen receptor beta expression was selectively upregulated 2-fold in calvarial osteoblasts. Most interestingly, the estrogen responsive transcriptional repressor RERG was constitutively expressed at 1000-fold greater levels in calvarial compared with femoral osteoblasts. RERG expression in calvarial osteoblasts was down regulated during osteogenic induction whereas upregulation occurred in femoral osteoblasts. Bone cells of the skull are inherently different to those of the femur, and respond differentially to a range of stimuli. These site-specific differences may have important relevance in the development of strategies to tackle metabolic bone disorders.
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Affiliation(s)
- Borzo Gharibi
- Division of Tissue Engineering and Biophotonics, Dental Institute, King's College London, Tower Wing, Guy's Hospital, London, SE1 9RT, UK.
| | - Mandeep S Ghuman
- Division of Tissue Engineering and Biophotonics, Dental Institute, King's College London, Tower Wing, Guy's Hospital, London, SE1 9RT, UK
| | - Giuseppe Cama
- Division of Tissue Engineering and Biophotonics, Dental Institute, King's College London, Tower Wing, Guy's Hospital, London, SE1 9RT, UK
| | - Simon C F Rawlinson
- Centre for Oral Growth and Development, Institute of Dentistry, Queen Mary University of London, New Road, London, E1 2BA, UK
| | - Agamemnon E Grigoriadis
- Centre for Craniofacial and Regenerative Biology, Dental Institute, King's College London, Tower Wing, Guy's Hospital, London, SE1 9RT, UK
| | - Francis J Hughes
- Division of Tissue Engineering and Biophotonics, Dental Institute, King's College London, Tower Wing, Guy's Hospital, London, SE1 9RT, UK.
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9
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Comparison of clavicular joints in human and laboratory rat. Biologia (Bratisl) 2018. [DOI: 10.2478/s11756-018-0130-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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10
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Abstract
Runx2 is the most upstream transcription factor essential for osteoblast differentiation. It regulates the expression of Sp7, the protein of which is a crucial transcription factor for osteoblast differentiation, as well as that of bone matrix genes including Spp1, Ibsp, and Bglap2. Runx2 is also required for chondrocyte maturation, and Runx3 has a redundant function with Runx2 in chondrocyte maturation. Runx2 regulates the expression of Col10a1, Spp1, Ibsp, and Mmp13 in chondrocytes. It also inhibits chondrocytes from acquiring the phenotypes of permanent cartilage chondrocytes. It regulates chondrocyte proliferation through the regulation of Ihh expression. Runx2 enhances osteoclastogenesis by regulating Rankl. Cbfb, which is a co-transcription factor for Runx family proteins, plays an important role in skeletal development by stabilizing Runx family proteins. In Cbfb isoforms, Cbfb1 is more potent than Cbfb2 in Runx2-dependent transcriptional regulation; however, the expression level of Cbfb2 is three-fold higher than that of Cbfb1, demonstrating the requirement of Cbfb2 in skeletal development. The expression of Runx2 in osteoblasts is regulated by a 343-bp enhancer located upstream of the P1 promoter. This enhancer is activated by an enhanceosome composed of Dlx5/6, Mef2, Tcf7, Ctnnb1, Sox5/6, Smad1, and Sp7. Thus, Runx2 is a multifunctional transcription factor that is essential for skeletal development, and Cbfb regulates skeletal development by modulating the stability and transcriptional activity of Runx family proteins.
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11
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Pollard AS, Boyd S, McGonnell IM, Pitsillides AA. The role of embryo movement in the development of the furcula. J Anat 2016; 230:435-443. [PMID: 27921302 DOI: 10.1111/joa.12571] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/03/2016] [Indexed: 11/27/2022] Open
Abstract
The pectoral girdle is a complex structure which varies in its morphology between species. A major component in birds is the furcula, which can be considered equivalent to a fusion of the paired clavicles found in many mammals, and the single interclavicle found in many reptiles. These elements are a remnant of the dermal skeleton and the only intramembranous bones in the trunk. Postnatally, the furcula plays important mechanical roles by stabilising the shoulder joint and acting as a mechanical spring during flight. In line with its mechanical role, previous studies indicate that, unlike many other intramembranous bones, furcula growth during development can be influenced by mechanical stimuli. This study investigated the response of individual aspects of furcula growth to both embryo immobilisation and hypermotility in the embryonic chicken. The impact of altered incubation temperature, which influences embryo motility, on crocodilian interclavicle development was also explored. We employed whole-mount bone and cartilage staining and 3D imaging by microCT to quantify the impact of rigid paralysis, flaccid paralysis and hypermobility on furcula growth in the chicken, and 3D microCT imaging to quantify the impact of reduced temperature (32-28 °C) and motility on interclavicle growth in the crocodile. This revealed that the growth rates of the clavicular and interclavicular components of the furcula differ during normal development. Total furcula area was reduced by total unloading produced by flaccid paralysis, but not by rigid paralysis which maintains static loading of embryonic bones. This suggests that dynamic loading, which is required for postnatal bone adaptation, is not a requirement for prenatal furcula growth. Embryo hypermotility also had no impact on furcula area or arm length. Furcula 3D shape did, however, differ between groups; this was marked in the interclavicular component of the furcula, the hypocleideum. Hypocleideum length was reduced by both methods of immobilisation, and interclavicle area was reduced in crocodile embryos incubated at 28 °C, which are less motile than embryos incubated at 32 °C. These data suggest that the clavicular and interclavicle components of the avian furcula respond differently to alterations in embryo movement, with the interclavicle requiring both the static and dynamic components of movement-related loading for normal growth, while static loading preserved most aspects of clavicle growth. Our data suggest that embryo movement, and the mechanical loading this produces, is important in shaping these structures during development to suit their postnatal mechanical roles.
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Affiliation(s)
| | - S Boyd
- Royal Veterinary College, London, UK
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12
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Shibata A, Machida J, Yamaguchi S, Kimura M, Tatematsu T, Miyachi H, Matsushita M, Kitoh H, Ishiguro N, Nakayama A, Higashi Y, Shimozato K, Tokita Y. Characterisation of novel RUNX2 mutation with alanine tract expansion from Japanese cleidocranial dysplasia patient. Mutagenesis 2015. [PMID: 26220009 DOI: 10.1093/mutage/gev057] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Cleidocranial dysplasia (CCD; MIM 119600) is an autosomal dominant skeletal dysplasia characterised by hypopalstic and/or aplastic clavicles, midface hypoplasia, absent or delayed closure of cranial sutures, moderately short stature, delayed eruption of permanent dentition and supernumerary teeth. The molecular pathogenesis can be explained in about two-thirds of CCD patients by haploinsufficiency of the RUNX2 gene. In our current study, we identified a novel and rare variant of the RUNX2 gene (c.181_189dupGCGGCGGCT) in a Japanese patient with phenotypic features of CCD. The insertion led an alanine tripeptide expansion (+3Ala) in the polyalanine tract. To date, a RUNX2 variant with alanine decapeptide expansion (+10Ala) is the only example of a causative variant of RUNX2 with polyalanine tract expansion to be reported, whilst RUNX2 (+1Ala) has been isolated from the healthy population. Thus, precise analyses of the RUNX2 (+3Ala) variant were needed to clarify whether the tripeptide expanded RUNX2 is a second disease-causing mutant with alanine tract expansion. We therefore investigated the biochemical properties of the mutant RUNX2 (+3Ala), which contains 20 alanine residues in the polyalanine tract. When transfected in COS7 cells, RUNX2 (+3Ala) formed intracellular ubiquitinated aggregates after 24h, and exerted a dominant negative effect in vitro. At 24h after gene transfection, whereas slight reduction was observed in RUNX2 (+10Ala), all of these mutants significantly activated osteoblast-specific element-2, a cis-acting sequence in the promoter of the RUNX2 target gene osteocalcin. The aggregation growth of RUNX2 (+3Ala) was clearly lower and slower than that of RUNX2 (+10Ala). Furthermore, we investigated several other RUNX2 variants with various alanine tract lengths, and found that the threshold for aggregation may be RUNX2 (+3Ala). We conclude that RUNX2 (+3Ala) is the cause of CCD in our current case, and that the accumulation of intracellular aggregates in vitro is related to the length of the alanine tract.
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Affiliation(s)
- Akio Shibata
- Department of Maxillofacial Surgery, Aichi-Gakuin University School of Dentistry, Nagoya 464-8651, Japan, Department of Perinatology, Institute for Developmental Research, Aichi Human Service Center, Kasugai 480-0392, Japan, Department of Oral and Maxillofacial Surgery, Ogaki Municipal Hospital, Ogaki 503-0864, Japan
| | - Junichiro Machida
- Department of Maxillofacial Surgery, Aichi-Gakuin University School of Dentistry, Nagoya 464-8651, Japan, Department of Oral and Maxillofacial Surgery, Toyota Memorial Hospital, Toyota 471-0821, Japan
| | - Seishi Yamaguchi
- Department of Maxillofacial Surgery, Aichi-Gakuin University School of Dentistry, Nagoya 464-8651, Japan, Department of Dentistry and Oral Surgery, Aichi Children's Health and Medical Center, Obu 474-8710, Japan
| | - Masashi Kimura
- Department of Maxillofacial Surgery, Aichi-Gakuin University School of Dentistry, Nagoya 464-8651, Japan, Department of Oral and Maxillofacial Surgery, Ogaki Municipal Hospital, Ogaki 503-0864, Japan
| | - Tadashi Tatematsu
- Department of Maxillofacial Surgery, Aichi-Gakuin University School of Dentistry, Nagoya 464-8651, Japan, Department of Perinatology, Institute for Developmental Research, Aichi Human Service Center, Kasugai 480-0392, Japan
| | - Hitoshi Miyachi
- Department of Maxillofacial Surgery, Aichi-Gakuin University School of Dentistry, Nagoya 464-8651, Japan
| | - Masaki Matsushita
- Department of Orthopaedic Surgery, Nagoya University, Graduate School of Medicine, Nagoya 466-8550, Aichi, Japan
| | - Hiroshi Kitoh
- Department of Orthopaedic Surgery, Nagoya University, Graduate School of Medicine, Nagoya 466-8550, Aichi, Japan
| | - Naoki Ishiguro
- Department of Orthopaedic Surgery, Nagoya University, Graduate School of Medicine, Nagoya 466-8550, Aichi, Japan
| | - Atsuo Nakayama
- Department of Embryology, Institute for Developmental Research, Aichi Human Service Center, Kasugai 480-0392, Japan
| | - Yujiro Higashi
- Department of Perinatology, Institute for Developmental Research, Aichi Human Service Center, Kasugai 480-0392, Japan
| | - Kazuo Shimozato
- Department of Maxillofacial Surgery, Aichi-Gakuin University School of Dentistry, Nagoya 464-8651, Japan
| | - Yoshihito Tokita
- Department of Maxillofacial Surgery, Aichi-Gakuin University School of Dentistry, Nagoya 464-8651, Japan, Department of Perinatology, Institute for Developmental Research, Aichi Human Service Center, Kasugai 480-0392, Japan,
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Qin X, Jiang Q, Matsuo Y, Kawane T, Komori H, Moriishi T, Taniuchi I, Ito K, Kawai Y, Rokutanda S, Izumi S, Komori T. Cbfb regulates bone development by stabilizing Runx family proteins. J Bone Miner Res 2015; 30:706-14. [PMID: 25262822 DOI: 10.1002/jbmr.2379] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2013] [Revised: 08/30/2014] [Accepted: 09/05/2014] [Indexed: 01/13/2023]
Abstract
Runx family proteins, Runx1, Runx2, and Runx3, play important roles in skeletal development. Runx2 is required for osteoblast differentiation and chondrocyte maturation, and haplodeficiency of RUNX2 causes cleidocranial dysplasia, which is characterized by open fontanelles and sutures and hypoplastic clavicles. Cbfb forms a heterodimer with Runx family proteins and enhances their DNA-binding capacity. Cbfb-deficient (Cbfb(-/-) ) mice die at midgestation because of the lack of fetal liver hematopoiesis. We previously reported that the partial rescue of hematopoiesis in Cbfb(-/-) mice revealed the requirement of Cbfb in skeletal development. However, the precise functions of Cbfb in skeletal development still remain to be clarified. We deleted Cbfb in mesenchymal cells giving rise to both chondrocyte and osteoblast lineages by mating Cbfb(fl/fl) mice with Dermo1 Cre knock-in mice. Cbfb(fl/fl/Cre) mice showed dwarfism, both intramembranous and endochondral ossifications were retarded, and chondrocyte maturation and proliferation and osteoblast differentiation were inhibited. The differentiation of chondrocytes and osteoblasts were severely inhibited in vitro, and the reporter activities of Ihh, Col10a1, and Bglap2 promoter constructs were reduced in Cbfb(fl/fl/Cre) chondrocytes or osteoblasts. The proteins of Runx1, Runx2, and Runx3 were reduced in the cartilaginous limb skeletons and calvariae of Cbfb(fl/fl/Cre) embryos compared with the respective protein in the respective tissue of Cbfb(fl/fl) embryos at E15.5, although the reduction of Runx2 protein in calvariae was much milder than that in cartilaginous limb skeletons. All of the Runx family proteins were severely reduced in Cbfb(fl/fl/Cre) primary osteoblasts, and Runx2 protein was less stable in Cbfb(fl/fl/Cre) osteoblasts than Cbfb(fl/fl) osteoblasts. These findings indicate that Cbfb is required for skeletal development by regulating chondrocyte differentiation and proliferation and osteoblast differentiation; that Cbfb plays an important role in the stabilization of Runx family proteins; and that Runx2 protein stability is less dependent on Cbfb in calvariae than in cartilaginous limb skeletons.
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Affiliation(s)
- Xin Qin
- Department of Cell Biology, Unit of Basic Medical Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
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14
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Funato N, Nakamura M, Richardson JA, Srivastava D, Yanagisawa H. Loss of Tbx1 induces bone phenotypes similar to cleidocranial dysplasia. Hum Mol Genet 2014; 24:424-35. [PMID: 25209980 DOI: 10.1093/hmg/ddu458] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
T-box transcription factor, TBX1, is the major candidate gene for 22q11.2 deletion syndrome (DiGeorge/ Velo-cardio-facial syndrome) characterized by facial defects, thymus hypoplasia, cardiovascular anomalies and cleft palates. Here, we report that the loss of Tbx1 in mouse (Tbx1(-/-)) results in skeletal abnormalities similar to those of cleidocranial dysplasia (CCD) in humans, which is an autosomal-dominant skeletal disease caused by mutations in RUNX2. Tbx1(-/-) mice display short stature, absence of hyoid bone, failed closure of fontanelle, bifid xiphoid process and hypoplasia of clavicle and zygomatic arch. A cell-type-specific deletion of Tbx1 in osteochondro-progenitor (Tbx1(OPKO)) or mesodermal (Tbx1(MKO)) lineage partially recapitulates the Tbx1(-/-) bone phenotypes. Although Tbx1 expression has not been previously reported in neural crest, inactivation of Tbx1 in the neural crest lineage (Tbx1(NCKO)) leads to an absence of the body of hyoid bone and postnatal lethality, indicating an unanticipated role of Tbx1 in neural crest development. Indeed, Tbx1 is expressed in the neural crest-derived hyoid bone primordium, in addition to mesoderm-derived osteochondral progenitors. Ablation of Tbx1 affected Runx2 expression in calvarial bones and overexpression of Tbx1 induced Runx2 expression in vitro. Taken together, our current studies reveal that Tbx1 is required for mesoderm- and neural crest-derived osteoblast differentiation and normal skeletal development. TBX1 mutation could lead to CCD-like bone phenotypes in human.
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Affiliation(s)
- Noriko Funato
- Research Center for Medical and Dental Sciences, Human Gene Sciences Research Division, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510, Japan Department of Molecular Biology and
| | - Masataka Nakamura
- Research Center for Medical and Dental Sciences, Human Gene Sciences Research Division, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510, Japan
| | - James A Richardson
- Department of Pathology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9148, USA and
| | - Deepak Srivastava
- Gladstone Institute of Cardiovascular Disease and Department of Pediatrics, University of California, San Francisco, 1650 Owens Street, San Francisco, CA 94158, USA
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15
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McGee-Lawrence ME, Carpio LR, Bradley EW, Dudakovic A, Lian JB, van Wijnen AJ, Kakar S, Hsu W, Westendorf JJ. Runx2 is required for early stages of endochondral bone formation but delays final stages of bone repair in Axin2-deficient mice. Bone 2014; 66:277-86. [PMID: 24973690 PMCID: PMC4125446 DOI: 10.1016/j.bone.2014.06.022] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 06/13/2014] [Accepted: 06/18/2014] [Indexed: 11/19/2022]
Abstract
Runx2 and Axin2 regulate skeletal development. We recently determined that Axin2 and Runx2 molecularly interact in differentiating osteoblasts to regulate intramembranous bone formation, but the relationship between these factors in endochondral bone formation was unresolved. To address this, we examined the effects of Axin2 deficiency on the cleidocranial dysplasia (CCD) phenotype of Runx2(+/-) mice, focusing on skeletal defects attributed to improper endochondral bone formation. Axin2 deficiency unexpectedly exacerbated calvarial components of the CCD phenotype in the Runx2(+/-) mice; the endocranial layer of the frontal suture, which develops by endochondral bone formation, failed to mineralize in Axin2(-/-):Runx2(+/-) mice, resulting in a cartilaginous, fibrotic and larger fontanel than observed in Runx2(+/-) mice. Transcripts associated with cartilage development (e.g., Acan, miR140) were expressed at higher levels, whereas blood vessel morphogenesis transcripts (e.g., Slit2) were suppressed in Axin2(-/-):Runx2(+/-) calvaria. Cartilage maturation was impaired, as primary chondrocytes from double mutant mice demonstrated delayed differentiation and produced less calcified matrix in vitro. The genetic dominance of Runx2 was also reflected during endochondral fracture repair, as both Runx2(+/-) and double mutant Axin2(-/-):Runx2(+/-) mice had enlarged fracture calluses at early stages of healing. However, by the end stages of fracture healing, double mutant animals diverged from the Runx2(+/-) mice, showing smaller calluses and increased torsional strength indicative of more rapid end stage bone formation as seen in the Axin2(-/-) mice. Taken together, our data demonstrate a dominant role for Runx2 in chondrocyte maturation, but implicate Axin2 as an important modulator of the terminal stages of endochondral bone formation.
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Affiliation(s)
| | | | | | | | | | | | | | - Wei Hsu
- University of Rochester Medical Center, Rochester, NY, USA
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Deprez PML, Nichane MG, Lengelé BG, Rezsöhazy R, Nyssen-Behets C. Molecular study of a Hoxa2 gain-of-function in chondrogenesis: a model of idiopathic proportionate short stature. Int J Mol Sci 2013; 14:20386-98. [PMID: 24129174 PMCID: PMC3821620 DOI: 10.3390/ijms141020386] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Revised: 09/16/2013] [Accepted: 09/16/2013] [Indexed: 12/31/2022] Open
Abstract
In a previous study using transgenic mice ectopically expressing Hoxa2 during chondrogenesis, we associated the animal phenotype to human idiopathic proportionate short stature. Our analysis showed that this overall size reduction was correlated with a negative influence of Hoxa2 at the first step of endochondral ossification. However, the molecular pathways leading to such phenotype are still unknown. Using protein immunodetection and histological techniques comparing transgenic mice to controls, we show here that the persistent expression of Hoxa2 in chondrogenic territories provokes a general down-regulation of the main factors controlling the differentiation cascade, such as Bapx1, Bmp7, Bmpr1a, Ihh, Msx1, Pax9, Sox6, Sox9 and Wnt5a. These data confirm the impairment of chondrogenic differentiation by Hoxa2 overexpression. They also show a selective effect of Hoxa2 on endochondral ossification processes since Gdf5 and Gdf10, and Bmp4 or PthrP were up-regulated and unmodified, respectively. Since Hoxa2 deregulation in mice induces a proportionate short stature phenotype mimicking human idiopathic conditions, our results give an insight into understanding proportionate short stature pathogenesis by highlighting molecular factors whose combined deregulation may be involved in such a disease.
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Affiliation(s)
- Pierre M. L. Deprez
- Ecole de Kinésiologie et Récréologie, Faculté des Sciences de la Santé et Services Communautaires, Université de Moncton, Moncton, NB E1A 3E9, Canada; E-Mail:
| | - Miloud G. Nichane
- Embryologie Moléculaire et Cellulaire Animale, Institut des Sciences de la Vie, Université catholique de Louvain, Louvain-la-Neuve 1348, Belgium; E-Mails: (M.G.N.); (R.R.)
| | - Benoît G. Lengelé
- Pôle de Morphologie, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels 1200, Belgium; E-Mail:
| | - René Rezsöhazy
- Embryologie Moléculaire et Cellulaire Animale, Institut des Sciences de la Vie, Université catholique de Louvain, Louvain-la-Neuve 1348, Belgium; E-Mails: (M.G.N.); (R.R.)
| | - Catherine Nyssen-Behets
- Pôle de Morphologie, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels 1200, Belgium; E-Mail:
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17
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Campeau P, Lenk G, Lu J, Bae Y, Burrage L, Turnpenny P, Román Corona-Rivera J, Morandi L, Mora M, Reutter H, Vulto-van Silfhout A, Faivre L, Haan E, Gibbs R, Meisler M, Lee B. Yunis-Varón syndrome is caused by mutations in FIG4, encoding a phosphoinositide phosphatase. Am J Hum Genet 2013; 92:781-91. [PMID: 23623387 DOI: 10.1016/j.ajhg.2013.03.020] [Citation(s) in RCA: 93] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 03/17/2013] [Accepted: 03/25/2013] [Indexed: 12/14/2022] Open
Abstract
Yunis-Varón syndrome (YVS) is an autosomal-recessive disorder with cleidocranial dysplasia, digital anomalies, and severe neurological involvement. Enlarged vacuoles are found in neurons, muscle, and cartilage. By whole-exome sequencing, we identified frameshift and missense mutations of FIG4 in affected individuals from three unrelated families. FIG4 encodes a phosphoinositide phosphatase required for regulation of PI(3,5)P(2) levels, and thus endosomal trafficking and autophagy. In a functional assay, both missense substitutions failed to correct the vacuolar phenotype of Fig4-null mouse fibroblasts. Homozygous Fig4-null mice exhibit features of YVS, including neurodegeneration and enlarged vacuoles in neurons. We demonstrate that Fig4-null mice also have small skeletons with reduced trabecular bone volume and cortical thickness and that cultured osteoblasts accumulate large vacuoles. Our findings demonstrate that homozygosity or compound heterozygosity for null mutations of FIG4 is responsible for YVS, the most severe known human phenotype caused by defective phosphoinositide metabolism. In contrast, in Charcot-Marie-Tooth disease type 4J (also caused by FIG4 mutations), one of the FIG4 alleles is hypomorphic and disease is limited to the peripheral nervous system. This genotype-phenotype correlation demonstrates that absence of FIG4 activity leads to central nervous system dysfunction and extensive skeletal anomalies. Our results describe a role for PI(3,5)P(2) signaling in skeletal development and maintenance.
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18
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Maeno T, Moriishi T, Yoshida CA, Komori H, Kanatani N, Izumi SI, Takaoka K, Komori T. Early onset of Runx2 expression caused craniosynostosis, ectopic bone formation, and limb defects. Bone 2011; 49:673-82. [PMID: 21807129 DOI: 10.1016/j.bone.2011.07.023] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Revised: 07/07/2011] [Accepted: 07/13/2011] [Indexed: 11/23/2022]
Abstract
RUNX2 is an essential transcription factor for osteoblast differentiation, because osteoblast differentiation is completely blocked in Runx2-deficient mice. However, it remains to be clarified whether RUNX2 is sufficient for osteoblast differentiation during embryogenesis. To address this issue, Runx2 transgenic mice were generated under the control of the Prrx1 promoter, which directs the transgene expression to mesenchymal cells before the onset of bone development. The transgene expression was detected in the cranium, limb buds, and the region from the mandible to anterior chest wall. The skull became small and the limbs were shortened depending on the levels of the transgene expression. Early onset of Runx2 expression in the cranial mesenchyme induced mineralization on E13.0, when no mineralization was observed in wild-type mice, and resulted in craniosynostosis as shown by the closure of sutures and fontanelles on E18.5. Col1a1 and Spp1 expressions were detected in the mineralized regions on E12.5-13.5. The limb bones were hypoplastic and fused, and ectopic bones were formed in the hands and feet. Col2a1 expression was inhibited but Col1a1 expression was induced in the limb buds on E12.5. In the anterior chest wall, ectopic bones were formed through the process of intramembranous ossification, interrupting the formation of cartilaginous anlagen of sternal manubrium. These findings indicate that RUNX2 is sufficient to direct mesenchymal cells to osteoblasts and lead to intramembranous bone formation during embryogenesis; Runx2 inhibits chondrocyte differentiation at an early stage; and that Runx2 expression at appropriate level, times and spaces during embryogenesis is essential for skeletal development.
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Affiliation(s)
- Takafumi Maeno
- Department of Cell Biology, Unit of Basic Medical Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8588, Japan
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19
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Zhang C, Zheng S, Wang Y, Zhao Y, Zhu J, Ge L. Mutational analysis of RUNX2 gene in Chinese patients with cleidocranial dysplasia. Mutagenesis 2010; 25:589-94. [DOI: 10.1093/mutage/geq044] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
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20
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Vickaryous MK, Hall BK. Comparative development of the crocodylian interclavicle and avian furcula, with comments on the homology of dermal elements in the pectoral apparatus. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2010; 314:196-207. [PMID: 20422674 DOI: 10.1002/jez.b.21326] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The pectoral apparatus (shoulder girdle plus sternum) of amniotes plesiomorphically includes an unpaired element of dermal origin. In crocodylians, lepidosaurs, and nontherian synapsids (monotremes and their ancestors) this element is identified as the interclavicle, in Testudines (turtles and tortoises) as the entoplastron, and in Aves as the furcula. We investigated embryonic development of the interclavicle in Alligator mississippiensis (American alligator) and of the furcula in Gallus gallus (domestic chicken). The interclavicle and furcula are among the first skeletal elements to ossify, beginning at Ferguson stage 19 (Alligator) and Hamburger and Hamilton stage 33 (Gallus). Both elements: occupy a similar mid-ventral position within the pectoral apparatus; develop from paired (bilateral) cell condensations; never coexist at anytime during ontogeny or in the adult; and undergo intramembranous (i.e., direct) ossification. For both the interclavicle and the furcula, the initial onset of ossification is concomitant with mineralization of elements of the dermatocranium, and occurs in advance of mineralization of the replacement bones (e.g., scapula, metacoracoid) of the pectoral apparatus. Shortly after the initiation of ossification the paired condensations of both elements fuse. For each of Alligator and Gallus, only one pair of skeletogenic condensations is present during embryonic development. Based on these data and a review of the evolution and development of dermal elements in the pectoral apparatus, we conclude that the interclavicle is equally parsimonious as a homolog of the furcula.
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Affiliation(s)
- Matthew K Vickaryous
- Department of Biomedical Sciences, University of Guelph, Guelph, Ontario, Canada.
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21
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El-Gharbawy AH, Peeden JN, Lachman RS, Graham JM, Moore SR, Rimoin DL. Severe cleidocranial dysplasia and hypophosphatasia in a child with microdeletion of the C-terminal region of RUNX2. Am J Med Genet A 2010; 152A:169-74. [PMID: 20014132 DOI: 10.1002/ajmg.a.33146] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cleidocranial dysplasia (CCD) is a rare autosomal dominant skeletal dysplasia due to mutations causing haploinsufficiency of RUNX2, an osteoblast transcription factor specific for bone and cartilage. The classic form of CCD is characterized by delayed closure of the fontanels, hypoplastic or aplastic clavicles and dental anomalies. Clinical reports suggest that a subset of patients with CCD have skeletal changes which mimic hypophosphatasia (HPP). Mutations in RUNX2 are detected in approximately 65% of cases of CCD, and microdeletions occur in 13%. We present clinical and radiological features in a 6-year-old child with severe CCD manifested by absence of the clavicles marked calvarial hypomineralization, osteoporosis and progressive kyphoscoliosis. HPP features included Bowdler spurs, severe osteopenia, and low alkaline phosphatase. Following negative mutation analysis of RUNX2, comparative genomic hybridization (CGH) microarray was performed. The result revealed a microdeletion in RUNX2, disrupting the C-terminal part of the gene.
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22
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Adult rat bones maintain distinct regionalized expression of markers associated with their development. PLoS One 2009; 4:e8358. [PMID: 20027296 PMCID: PMC2792039 DOI: 10.1371/journal.pone.0008358] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2009] [Accepted: 11/21/2009] [Indexed: 12/31/2022] Open
Abstract
The incidence of limb bone fracture and subsequent morbidity and mortality due to excessive bone loss is increasing in the progressively ageing populations of both men and women. In contrast to bone loss in the weight-bearing limb, bone mass in the protective skull vault is maintained. One explanation for this could be anatomically diverse bone matrix characteristics generated by heterogeneous osteoblast populations. We have tested the hypothesis that adult bones demonstrate site-specific characteristics, and report differences at the organ, cell and transcriptome levels. Limb bones contain greater amounts of polysulphated glycosaminoglycan stained with Alcian Blue and have significantly higher osteocyte densities than skull bone. Site-specific patterns persist in cultured adult bone-derived cells both phenotypically (proliferation rate, response to estrogen and cell volumes), and at the level of specific gene expression (collagen triple helix repeat containing 1, reelin and ras-like and estrogen-regulated growth inhibitor). Based on genome-wide mRNA expression and cluster analysis, we demonstrate that bones and cultured adult bone-derived cells segregate according to site of derivation. We also find the differential expression of genes associated with embryological development (Skull: Zic, Dlx, Irx, Twist1 and Cart1; Limb: Hox, Shox2, and Tbx genes) in both adult bones and isolated adult bone-derived cells. Together, these site-specific differences support the view that, analogous to different muscle types (cardiac, smooth and skeletal), skull and limb bones represent separate classes of bone. We assign these differences, not to mode of primary ossification, but to the embryological cell lineage; the basis and implications of this division are discussed.
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San Martin I, Varela N, Gaete M, Villegas K, Osorio M, Tapia JC, Antonelli M, Mancilla E, Lian JB, Stein JL, Stein GS, van Wijnen AJ, Galindo M. Impaired cell cycle regulation of the osteoblast-related heterodimeric transcription factor Runx2-Cbfbeta in osteosarcoma cells. J Cell Physiol 2009; 221:560-71. [PMID: 19739101 PMCID: PMC3066433 DOI: 10.1002/jcp.21894] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Bone formation and osteoblast differentiation require the functional expression of the Runx2/Cbfbeta heterodimeric transcription factor complex. Runx2 is also a suppressor of proliferation in osteoblasts by attenuating cell cycle progression in G(1). Runx2 levels are modulated during the cell cycle, which are maximal in G(1) and minimal beyond the G(1)/S phase transition (S, G(2), and M phases). It is not known whether Cbfbeta gene expression is cell cycle controlled in preosteoblasts nor how Runx2 or Cbfbeta are regulated during the cell cycle in bone cancer cells. We investigated Runx2 and Cbfbeta gene expression during cell cycle progression in MC3T3-E1 osteoblasts, as well as ROS17/2.8 and SaOS-2 osteosarcoma cells. Runx2 protein levels are reduced as expected in MC3T3-E1 cells arrested in late G(1) (by mimosine) or M phase (by nocodazole), but not in cell cycle arrested osteosarcoma cells. Cbfbeta protein levels are cell cycle independent in both osteoblasts and osteosarcoma cells. In synchronized MC3T3-E1 osteoblasts progressing from late G1 or mitosis, Runx2 levels but not Cbfbeta levels are cell cycle regulated. However, both factors are constitutively elevated throughout the cell cycle in osteosarcoma cells. Proteasome inhibition by MG132 stabilizes Runx2 protein levels in late G(1) and S in MC3T3-E1 cells, but not in ROS17/2.8 and SaOS-2 osteosarcoma cells. Thus, proteasomal degradation of Runx2 is deregulated in osteosarcoma cells. We propose that cell cycle control of Runx2 gene expression is impaired in osteosarcomas and that this deregulation may contribute to the pathogenesis of osteosarcoma.
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Affiliation(s)
- Inga San Martin
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences (I.C.B.M.), Faculty of Medicine, University of Chile, Santiago, Chile
| | - Nelson Varela
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences (I.C.B.M.), Faculty of Medicine, University of Chile, Santiago, Chile
| | - Marcia Gaete
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences (I.C.B.M.), Faculty of Medicine, University of Chile, Santiago, Chile
| | - Karina Villegas
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences (I.C.B.M.), Faculty of Medicine, University of Chile, Santiago, Chile
| | - Mariana Osorio
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences (I.C.B.M.), Faculty of Medicine, University of Chile, Santiago, Chile
| | - Julio C. Tapia
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences (I.C.B.M.), Faculty of Medicine, University of Chile, Santiago, Chile
| | - Marcelo Antonelli
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences (I.C.B.M.), Faculty of Medicine, University of Chile, Santiago, Chile
| | - Edna Mancilla
- Program of Pathophysiology, Institute of Biomedical Sciences (I.C.B.M.), Faculty of Medicine, University of Chile, Santiago, Chile
| | - Jane B. Lian
- Department of Cell Biology and Cancer Center, University of Massachusetts Medical School, Worcester, MA 01655-0105
| | - Janet L. Stein
- Department of Cell Biology and Cancer Center, University of Massachusetts Medical School, Worcester, MA 01655-0105
| | - Gary S Stein
- Department of Cell Biology and Cancer Center, University of Massachusetts Medical School, Worcester, MA 01655-0105
| | - Andre J. van Wijnen
- Department of Cell Biology and Cancer Center, University of Massachusetts Medical School, Worcester, MA 01655-0105
| | - Mario Galindo
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences (I.C.B.M.), Faculty of Medicine, University of Chile, Santiago, Chile
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Lou Y, Javed A, Hussain S, Colby J, Frederick D, Pratap J, Xie R, Gaur T, van Wijnen AJ, Jones SN, Stein GS, Lian JB, Stein JL. A Runx2 threshold for the cleidocranial dysplasia phenotype. Hum Mol Genet 2008; 18:556-68. [PMID: 19028669 DOI: 10.1093/hmg/ddn383] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Cleidocranial dysplasia (CCD) in humans is an autosomal-dominant skeletal disease that results from mutations in the bone-specific transcription factor RUNX2 (CBFA1/AML3). However, distinct RUNX2 mutations in CCD do not correlate with the severity of the disease. Here we generated a new mouse model with a hypomorphic Runx2 mutant allele (Runx2(neo7)), in which only part of the transcript is processed to full-length (wild-type) Runx2 mRNA. Homozygous Runx2(neo7/neo7) mice express a reduced level of wild-type Runx2 mRNA (55-70%) and protein. This mouse model allowed us to establish the minimal requirement of functional Runx2 for normal bone development. Runx2(neo7/neo7) mice have grossly normal skeletons with no abnormalities observed in the growth plate, but do exhibit developmental defects in calvaria and clavicles that persist through post-natal growth. Clavicle defects are caused by disrupted endochondral bone formation during embryogenesis. These hypomorphic mice have altered calvarial bone volume, as observed by histology and microCT imaging, and decreased expression of osteoblast marker genes. The bone phenotype of the heterozygous mice, which have 79-84% of wild-type Runx2 mRNA, is normal. These results show there is a critical gene dosage requirement of functional Runx2 for the formation of intramembranous bone tissues during embryogenesis. A decrease to 70% of wild-type Runx2 levels results in the CCD syndrome, whereas levels >79% produce a normal skeleton. Our findings suggest that the range of bone phenotypes in CCD patients is attributable to quantitative reduction in the functional activity of RUNX2.
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Affiliation(s)
- Yang Lou
- Department of Cell Biology, Cancer Center, University of Massachusetts Medical School, Worcester, MA 01655-0106, USA
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McBratney-Owen B, Iseki S, Bamforth SD, Olsen BR, Morriss-Kay GM. Development and tissue origins of the mammalian cranial base. Dev Biol 2008; 322:121-32. [PMID: 18680740 PMCID: PMC2847450 DOI: 10.1016/j.ydbio.2008.07.016] [Citation(s) in RCA: 184] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2008] [Revised: 07/10/2008] [Accepted: 07/10/2008] [Indexed: 10/21/2022]
Abstract
The vertebrate cranial base is a complex structure composed of bone, cartilage and other connective tissues underlying the brain; it is intimately connected with development of the face and cranial vault. Despite its central importance in craniofacial development, morphogenesis and tissue origins of the cranial base have not been studied in detail in the mouse, an important model organism. We describe here the location and time of appearance of the cartilages of the chondrocranium. We also examine the tissue origins of the mouse cranial base using a neural crest cell lineage cell marker, Wnt1-Cre/R26R, and a mesoderm lineage cell marker, Mesp1-Cre/R26R. The chondrocranium develops between E11 and E16 in the mouse, beginning with development of the caudal (occipital) chondrocranium, followed by chondrogenesis rostrally to form the nasal capsule, and finally fusion of these two parts via the midline central stem and the lateral struts of the vault cartilages. X-Gal staining of transgenic mice from E8.0 to 10 days post-natal showed that neural crest cells contribute to all of the cartilages that form the ethmoid, presphenoid, and basisphenoid bones with the exception of the hypochiasmatic cartilages. The basioccipital bone and non-squamous parts of the temporal bones are mesoderm derived. Therefore the prechordal head is mostly composed of neural crest-derived tissues, as predicted by the New Head Hypothesis. However, the anterior location of the mesoderm-derived hypochiasmatic cartilages, which are closely linked with the extra-ocular muscles, suggests that some tissues associated with the visual apparatus may have evolved independently of the rest of the "New Head".
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Affiliation(s)
- B McBratney-Owen
- Harvard School of Dental Medicine, Department of Developmental Biology, 190 Longwood Avenue, Boston, MA, 02115, USA.
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27
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Kawasaki Y, Kugimiya F, Chikuda H, Kamekura S, Ikeda T, Kawamura N, Saito T, Shinoda Y, Higashikawa A, Yano F, Ogasawara T, Ogata N, Hoshi K, Hofmann F, Woodgett JR, Nakamura K, Chung UI, Kawaguchi H. Phosphorylation of GSK-3beta by cGMP-dependent protein kinase II promotes hypertrophic differentiation of murine chondrocytes. J Clin Invest 2008; 118:2506-15. [PMID: 18551195 DOI: 10.1172/jci35243] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2008] [Accepted: 05/07/2008] [Indexed: 11/17/2022] Open
Abstract
cGMP-dependent protein kinase II (cGKII; encoded by PRKG2) is a serine/threonine kinase that is critical for skeletal growth in mammals; in mice, cGKII deficiency results in dwarfism. Using radiographic analysis, we determined that this growth defect was a consequence of an elongated growth plate and impaired chondrocyte hypertrophy. To investigate the mechanism of cGKII-mediated chondrocyte hypertrophy, we performed a kinase substrate array and identified glycogen synthase kinase-3beta (GSK-3beta; encoded by Gsk3b) as a principal phosphorylation target of cGKII. In cultured mouse chondrocytes, phosphorylation-mediated inhibition of GSK-3beta was associated with enhanced hypertrophic differentiation. Furthermore, cGKII induction of chondrocyte hypertrophy was suppressed by cotransfection with a phosphorylation-deficient mutant of GSK-3beta. Analyses of mice with compound deficiencies in both protein kinases (Prkg2(-/-)Gsk3b(+/-)) demonstrated that the growth retardation and elongated growth plate associated with cGKII deficiency were partially rescued by haploinsufficiency of Gsk3b. We found that beta-catenin levels decreased in Prkg2(-/-) mice, while overexpression of cGKII increased the accumulation and transactivation function of beta-catenin in mouse chondroprogenitor ATDC5 cells. This effect was blocked by coexpression of phosphorylation-deficient GSK-3beta. These data indicate that hypertrophic differentiation of growth plate chondrocytes during skeletal growth is promoted by phosphorylation and inactivation of GSK-3beta by cGKII.
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Affiliation(s)
- Yosuke Kawasaki
- Sensory and Motor System Medicine, Faculty of Medicine, University of Tokyo, Tokyo, Japan
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28
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Wilkosz S, Epstein J, de Giorgio-Miller A, McLean W, Ireland G, Herrick S. Remodelling of adipose tissue during experimental omental adhesion formation. Br J Surg 2008; 95:387-96. [DOI: 10.1002/bjs.6073] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Abstract
Background
Peritoneal adhesions are fibrous bands of tissue connecting normally separated organs and frequently involve the fat-laden greater omentum. Remodelling of fibrin-rich exudate under reduced fibrinolytic conditions is thought to initiate adhesion formation following surgery. It is unclear whether adhesions that involve the omentum develop in a similar manner. To improve understanding of omental adhesion formation, adipose tissue distribution, cell proliferation and procollagen type I gene expression were investigated in a murine surgical model and in established omental adhesions from patients undergoing abdominal surgery.
Methods
Experimental murine omental adhesions and human omental adhesions were analysed for signs of tissue remodelling using histology, immunohistochemistry and in situ hybridization.
Results
Murine omental tissue showed intense inflammation and reduced adipose tissue 3–7 days after surgery, but increased cellularity and collagen production. Adipose tissue remodelling was reversible with increased adipose tissue and decreased cell proliferation and procollagen type I gene expression, shown by proliferating cell nuclear antigen immunolocalization and in situ hybridization respectively. Human omental adhesions were heterogeneous, with varying amounts of fibrotic and adipose-rich regions, although most displayed proliferating and collagen-producing cells.
Conclusion
Omental adhesions are not static scar tissue as traditionally thought, but undergo active adipose tissue remodelling over-time.
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Affiliation(s)
- S Wilkosz
- Faculty of Life Sciences, University of Manchester, Manchester, UK
| | - J Epstein
- Faculty of Life Sciences, University of Manchester, Manchester, UK
| | | | - W McLean
- Faculty of Life Sciences, University of Manchester, Manchester, UK
| | - G Ireland
- Faculty of Life Sciences, University of Manchester, Manchester, UK
| | - S Herrick
- School of Medicine, Faculty of Medical and Human Sciences, University of Manchester, Manchester, UK
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29
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Impaired skin and hair follicle development in Runx2 deficient mice. Dev Biol 2008; 315:459-73. [PMID: 18262513 PMCID: PMC2280036 DOI: 10.1016/j.ydbio.2008.01.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2007] [Revised: 12/11/2007] [Accepted: 01/03/2008] [Indexed: 11/20/2022]
Abstract
The transcription factor, Runx2, is known to play crucial roles in skeletal and tooth morphogenesis. Here we document that Runx2 has a regulatory role in skin and hair follicle development. The expression of Runx2 is restricted to hair follicles and is dynamic, pari passu with follicle development. Follicle maturation is delayed in the absence of Runx2 and overall skin and epidermal thickness of Runx2 null embryos is significantly reduced. The Runx2 null epidermis is hypoplastic, displaying reduced expression of Keratin 14, Keratin 1 and markers of proliferation. The expression pattern of Runx2 in the bulb epithelium of mature hair follicles is asymmetric and strikingly similar to that of Sonic hedgehog. This suggests that Runx2 may be a regulator of hedgehog signaling in skin as it is in bones and teeth. Supporting this possibility, we demonstrate that Sonic hedgehog, Patched1 and Gli1 transcripts are reduced in the skin of Runx2 null embryos. Moreover, we document Patched1 expression in epidermal basal cells and show that the skin of Sonic(+/-) embryos is thinner than that of wild-type littermates. These observations suggest that Runx2 and hedgehog signaling are involved in the well known, but unexplained, coupling of skin thickness to hair follicle development.
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30
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Vaes BLT, Ducy P, Sijbers AM, Hendriks JMA, van Someren EP, de Jong NG, van den Heuvel ER, Olijve W, van Zoelen EJJ, Dechering KJ. Microarray analysis on Runx2-deficient mouse embryos reveals novel Runx2 functions and target genes during intramembranous and endochondral bone formation. Bone 2006; 39:724-38. [PMID: 16774856 DOI: 10.1016/j.bone.2006.04.024] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2006] [Revised: 04/10/2006] [Accepted: 04/20/2006] [Indexed: 10/24/2022]
Abstract
A major challenge in developmental biology is to correlate genome-wide gene expression modulations with developmental processes in vivo. In this study, we analyzed the role of Runx2 during intramembranous and endochondral bone development, by comparing gene expression profiles in 14.5 dpc wild-type and Runx2 (-/-) mice. A total of 1277, 606 and 492 transcripts were found to be significantly modulated by Runx2 in calvaria, forelimbs and hindlimbs, respectively. Bioinformatics analysis indicated that Runx2 not only controls the processes of osteoblast differentiation and chondrocyte maturation, but may also play a role in axon formation and hematopoietic cell commitment during bone development. A total of 41 genes are affected by the Runx2 deletion in both intramembranous and endochondral bone, indicating common pathways between these two developmental modes of bone formation. In addition, we identified genes that are specifically involved in endochondral ossification. In conclusion, our data show that a comparative genome-wide expression analysis of wild-type and mutant mouse models allows the examination of mutant phenotypes in complex tissues.
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Affiliation(s)
- Bart L T Vaes
- Department of Applied Biology FNWI, Radboud University Nijmegen, Toernooiveld 1, 6525 ED Nijmegen, The Netherlands
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31
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Baumert U, Golan I, Redlich M, Aknin JJ, Muessig D. Cleidocranial dysplasia: molecular genetic analysis and phenotypic-based description of a Middle European patient group. Am J Med Genet A 2006; 139A:78-85. [PMID: 16222673 DOI: 10.1002/ajmg.a.30927] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Cleidocranial dysplasia (CCD) (OMIM 119600) is a rare dysplasia of osseous and dental tissue. Characteristic features are typical facial and dental appearance plus morphologic anomalies. RUNX2 (OMIM 600211), the responsible gene for CCD, is considered to be a master gene for bone development and bone homeostasis. This study describes the genotype-phenotype correlation based on craniofacial features involving an interdisciplinary approach. Our patient cohort consisted of 31 CCD patients from 20 families; five patients from two families were unavailable for clinical examination. Since CCD mostly affects the craniofacial region, phenotypic characterization of each individual focused on craniofacial and dental aspects. After recording patient medical and family history, the phenotypic data was analyzed using homogeneity analysis (HOMALS), a statistical procedure for data reduction in categorical data analysis. The coding sequence of the RUNX2 gene was analyzed using PCR, direct sequencing, and restriction endonuclease digestion. Eight unpublished and four known heterozygous mutations in a total of 14/20 index patients (70%) were identified. In total, we detected 7 missense mutations, 5 frameshift mutations, and 2 nonsense mutations in 14 index patients (35%, 25%, 10%, respectively). The overall CCD phenotype varied from mild to fullblown expression. Using HOMALS, we were able to discriminate four groups of patients showing significant differences in phenotypic expressivity, thereby simplifying the grouping of our large patient cohort into clear distinguishable entities. Analysis of the mutation patterns revealed that mutational frequency and types of mutations found can be attributed to the gene's structure and function.
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Affiliation(s)
- Uwe Baumert
- Department of Orthodontics, Center for Craniofacial Genetics, University of Regensburg, Regensburg, Germany.
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32
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Abstract
Bone and cartilage and their disorders are addressed under the following headings: functions of bone; normal and abnormal bone remodeling; osteopetrosis and osteoporosis; epithelial-mesenchymal interaction, condensation and differentiation; osteoblasts, markers of bone formation, osteoclasts, components of bone, and pathology of bone; chondroblasts, markers of cartilage formation, secondary cartilage, components of cartilage, and pathology of cartilage; intramembranous and endochondral bone formation; RUNX genes and cleidocranial dysplasia (CCD); osterix; histone deacetylase 4 and Runx2; Ligand to receptor activator of NFkappaB (RANKL), RANK, osteoprotegerin, and osteoimmunology; WNT signaling, LRP5 mutations, and beta-catenin; the role of leptin in bone remodeling; collagens, collagenopathies, and osteogenesis imperfecta; FGFs/FGFRs, FGFR3 skeletal dysplasias, craniosynostosis, and other disorders; short limb chondrodysplasias; molecular control of the growth plate in endochondral bone formation and genetic disorders of IHH and PTHR1; ANKH, craniometaphyseal dysplasia, and chondrocalcinosis; transforming growth factor beta, Camurati-Engelmann disease (CED), and Marfan syndrome, types I and II; an ACVR1 mutation and fibrodysplasia ossificans progressiva; MSX1 and MSX2: biology, mutations, and associated disorders; G protein, activation of adenylyl cyclase, GNAS1 mutations, McCune-Albright syndrome, fibrous dysplasia, and Albright hereditary osteodystrophy; FLNA and associated disorders; and morphological development of teeth and their genetic mutations.
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Affiliation(s)
- M Michael Cohen
- Department of Pediatrics, Dalhousie University, Halifax, Nova Scotia, Canada.
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33
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Zheng Q, Sebald E, Zhou G, Chen Y, Wilcox W, Lee B, Krakow D. Dysregulation of chondrogenesis in human cleidocranial dysplasia. Am J Hum Genet 2005; 77:305-12. [PMID: 15952089 PMCID: PMC1224532 DOI: 10.1086/432261] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2005] [Accepted: 05/26/2005] [Indexed: 12/27/2022] Open
Abstract
Cleidocranial dysplasia (CCD) is an autosomal dominant skeletal dysplasia caused by heterozygosity of mutations in human RUNX2. The disorder is characterized by delayed closure of the fontanel and hypoplastic clavicles that result from defective intramembranous ossification. However, additional features, such as short stature and cone epiphyses, also suggest an underlying defect in endochondral ossification. Here, we report observations of growth-plate abnormalities in a patient with a novel RUNX2 gene mutation, a single C insertion (1228insC), which is predicted to lead to a premature termination codon and thus to haploinsufficiency of RUNX2 and the CCD phenotype. Histological analysis of the rib and long-bone cartilages showed a markedly diminished zone of hypertrophy. Quantitative real-time reverse transcription-polymerase chain reaction analysis of limb cartilage RNA showed a 5-10-fold decrease in the hypertrophic chondrocyte molecular markers VEGF, MMP13, and COL10A1. Together, these data show that humans with CCD have altered endochondral ossification due to altered RUNX2 regulation of hypertrophic chondrocyte-specific genes during chondrocyte maturation.
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Affiliation(s)
- Qiping Zheng
- Department of Molecular and Human Genetics and Howard Hughes Medical Institute, Baylor College of Medicine, Houston; and Medical Genetics Institute, Department of Pediatrics, Cedars-Sinai Medical Center, and David Geffen School of Medicine at University of California–Los Angeles, Los Angeles
| | - Eiman Sebald
- Department of Molecular and Human Genetics and Howard Hughes Medical Institute, Baylor College of Medicine, Houston; and Medical Genetics Institute, Department of Pediatrics, Cedars-Sinai Medical Center, and David Geffen School of Medicine at University of California–Los Angeles, Los Angeles
| | - Guang Zhou
- Department of Molecular and Human Genetics and Howard Hughes Medical Institute, Baylor College of Medicine, Houston; and Medical Genetics Institute, Department of Pediatrics, Cedars-Sinai Medical Center, and David Geffen School of Medicine at University of California–Los Angeles, Los Angeles
| | - Yuqing Chen
- Department of Molecular and Human Genetics and Howard Hughes Medical Institute, Baylor College of Medicine, Houston; and Medical Genetics Institute, Department of Pediatrics, Cedars-Sinai Medical Center, and David Geffen School of Medicine at University of California–Los Angeles, Los Angeles
| | - William Wilcox
- Department of Molecular and Human Genetics and Howard Hughes Medical Institute, Baylor College of Medicine, Houston; and Medical Genetics Institute, Department of Pediatrics, Cedars-Sinai Medical Center, and David Geffen School of Medicine at University of California–Los Angeles, Los Angeles
| | - Brendan Lee
- Department of Molecular and Human Genetics and Howard Hughes Medical Institute, Baylor College of Medicine, Houston; and Medical Genetics Institute, Department of Pediatrics, Cedars-Sinai Medical Center, and David Geffen School of Medicine at University of California–Los Angeles, Los Angeles
| | - Deborah Krakow
- Department of Molecular and Human Genetics and Howard Hughes Medical Institute, Baylor College of Medicine, Houston; and Medical Genetics Institute, Department of Pediatrics, Cedars-Sinai Medical Center, and David Geffen School of Medicine at University of California–Los Angeles, Los Angeles
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34
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Matsuoka T, Ahlberg PE, Kessaris N, Iannarelli P, Dennehy U, Richardson WD, McMahon AP, Koentges G. Neural crest origins of the neck and shoulder. Nature 2005; 436:347-55. [PMID: 16034409 PMCID: PMC1352163 DOI: 10.1038/nature03837] [Citation(s) in RCA: 371] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2004] [Accepted: 05/20/2005] [Indexed: 11/08/2022]
Abstract
The neck and shoulder region of vertebrates has undergone a complex evolutionary history. To identify its underlying mechanisms we map the destinations of embryonic neural crest and mesodermal stem cells using Cre-recombinase-mediated transgenesis. The single-cell resolution of this genetic labelling reveals cryptic cell boundaries traversing the seemingly homogeneous skeleton of the neck and shoulders. Within this assembly of bones and muscles we discern a precise code of connectivity that mesenchymal stem cells of both neural crest and mesodermal origin obey as they form muscle scaffolds. The neural crest anchors the head onto the anterior lining of the shoulder girdle, while a Hox-gene-controlled mesoderm links trunk muscles to the posterior neck and shoulder skeleton. The skeleton that we identify as neural crest-derived is specifically affected in human Klippel-Feil syndrome, Sprengel's deformity and Arnold-Chiari I/II malformation, providing insights into their likely aetiology. We identify genes involved in the cellular modularity of the neck and shoulder skeleton and propose a new method for determining skeletal homologies that is based on muscle attachments. This has allowed us to trace the whereabouts of the cleithrum, the major shoulder bone of extinct land vertebrate ancestors, which seems to survive as the scapular spine in living mammals.
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Affiliation(s)
- Toshiyuki Matsuoka
- Wolfson Institute for Biomedical Research, UCL, Gower Street, London WC1E 6BT
- Laboratory of Functional Genomics
| | - Per E. Ahlberg
- Subdepartment of Evolutionary Organismal Biology, Department of Physiology and Developmental Biology, Uppsala University, Norbyvägen 18 A, 752 36 Uppsala, Sweden
| | - Nicoletta Kessaris
- Wolfson Institute for Biomedical Research, UCL, Gower Street, London WC1E 6BT
| | - Palma Iannarelli
- Wolfson Institute for Biomedical Research, UCL, Gower Street, London WC1E 6BT
| | - Ulla Dennehy
- Wolfson Institute for Biomedical Research, UCL, Gower Street, London WC1E 6BT
| | - William D. Richardson
- Wolfson Institute for Biomedical Research, UCL, Gower Street, London WC1E 6BT
- Department of Biology, UCL
| | - Andrew P. McMahon
- Department of Molecular and Cellular Biology, Harvard University, Divinity Avenue 02138 Cambridge, MA, USA
| | - Georgy Koentges
- Wolfson Institute for Biomedical Research, UCL, Gower Street, London WC1E 6BT
- Laboratory of Functional Genomics
- Department of Biology, UCL
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35
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Smith N, Dong Y, Lian JB, Pratap J, Kingsley PD, van Wijnen AJ, Stein JL, Schwarz EM, O'Keefe RJ, Stein GS, Drissi MH. Overlapping expression of Runx1(Cbfa2) and Runx2(Cbfa1) transcription factors supports cooperative induction of skeletal development. J Cell Physiol 2005; 203:133-43. [PMID: 15389629 DOI: 10.1002/jcp.20210] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Identifying the genetic pathways that regulate skeletal development is necessary to correct a variety of cartilage and bone abnormalities. The Runx family of transcription factors play a fundamental role in organ development and cell differentiation. Initial studies have shown that both Runx1 and Runx2 are expressed in pre-chondrogenic mesenchyme of the developing embryo at E12.5. Abrogation of the Runx2 gene completely inhibits bone formation yet the cartilage anlagen in these mice is fully formed. In the present study, we hypothesized that Runx1 may compensate for the lack of Runx2 in vivo to induce the early stages of skeletal formation and development. Histologic beta-gal stained sections using the Runx1(+/-)-Lac-Z mice demonstrate Runx1 promoter activity in pre-chondrocytic cell populations. In situ hybridization using Runx1 and Runx2 specific probes indicate that both factors are expressed in mesenchymal stem cell progenitors during early embryonic development. During later stages of mouse skeletal formation, Runx1 is excluded from the hypertrophic cartilage while Runx2 is present in these matured chondrocyte populations. Quantification of Runx expression by real time RT-PCR and Western blot analyses reveals that Runx1 and Runx2 are differentially modulated during embryogenesis suggesting a temporal role for each of these transcriptional regulators during skeletal formation. We provide evidence that haploinsufficiency results in normal appearing embryo skeletons of heterozygote Runx2 and Runx1 mutant mouse models; however, a delay in bone formation was identified in the calvarium. In summary, our results support a function for Runx1 and Runx2 during skeletal development with a possible role for Runx1 in mediating early events of endochondral and intramembranous bone formation, while Runx2 is a potent inducer of late stages of chondrocyte and osteoblast differentiation.
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Affiliation(s)
- Nathan Smith
- The Center for Musculoskeletal Research, University of Rochester, Rochester, New York, USA
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36
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Drissi MH, Li X, Sheu TJ, Zuscik MJ, Schwarz EM, Puzas JE, Rosier RN, O'Keefe RJ. Runx2/Cbfa1 stimulation by retinoic acid is potentiated by BMP2 signaling through interaction with Smad1 on the collagen X promoter in chondrocytes. J Cell Biochem 2004; 90:1287-98. [PMID: 14635200 DOI: 10.1002/jcb.10677] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Chondrocyte differentiation is a fundamental process during endochondral ossification. Several factors regulate maturation via the activity of downstream signaling pathways that target specific transcription factors and regulate chondrocyte-specific genes. In this study, we investigated the mechanisms involved in the regulation of chick lower sternal chondrocyte maturation upon stimulation by retinoic acid (RA) and the bone morphogenetic protein BMP2. RA-induced Runx2 in lower sternal chondrocyte cultures and over-expression of wild-type (WT) Runx2 enhanced colX and alkaline phosphatase activity, while over-expression of dominant negative Runx2 was inhibitory. Furthermore, WT Runx2 enhanced the effects of both BMP2 and RA on colX expression, while the effects of both growth factors were completely blocked in cultures over-expressing dominant negative Runx2. Similarly, WT Runx2 enhanced the induction of colX by Smad1. Smad1 and Runx2 were found to act cooperatively at the chicken type X collagen promoter and elimination of either the putative Smad binding site or Runx2 binding site eliminated responsiveness to BMP2, RA, or either of the transcription factors. Altogether the results show cross talk between the BMP-associated Smads and Runx2 during chondrocyte differentiation and dependence upon both signals for induction of the type X collagen promoter. Factors or signals that alter either of these transcription factors regulate the rate of chondrocyte differentiation.
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Affiliation(s)
- M Hicham Drissi
- The Center for Musculoskeletal Research, University of Rochester, Rochester, New York 14642, USA
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37
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Wang W, Wang YG, Reginato AM, Glotzer DJ, Fukai N, Plotkina S, Karsenty G, Olsen BR. Groucho homologue Grg5 interacts with the transcription factor Runx2-Cbfa1 and modulates its activity during postnatal growth in mice. Dev Biol 2004; 270:364-81. [PMID: 15183720 DOI: 10.1016/j.ydbio.2004.03.003] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2003] [Revised: 02/09/2004] [Accepted: 03/04/2004] [Indexed: 11/28/2022]
Abstract
Runx2-Cbfa1, a Runt transcription factor, plays important roles during skeletal development. It is required for differentiation and function of osteoblasts. In its absence, chondrocyte hypertrophy is severely impaired and there is no vascularization of cartilage templates during skeletal development. These tissue-specific functions of Runx2 are likely to be dependent on its interaction with other proteins. We have therefore searched for proteins that may modulate the activity of Runx2. The yeast two-hybrid system was used to identify a groucho homologue, Grg5, as a Runx2-interacting protein. Grg5 enhances Runx2 activity in a cell culture-based assay and by analyses of postnatal growth in mice we demonstrate that Grg5 and Runx2 interact genetically. We also show that Runx2 haploinsufficiency in the absence of Grg5 results in a more severe delay in ossification of cranial sutures and fontanels than occurs with Runx2 haploinsufficiency on a wild-type background. Finally, we find shortening of the proliferative and hypertrophic zones, and expansion of the resting zone in the growth plates of Runx2(+/-) Grg5(-/-) mice that are associated with reduced Ihh expression and Indian hedgehog (Ihh) signaling. We therefore conclude that Grg5 enhances Runx2 activity in vivo.
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Affiliation(s)
- WenFang Wang
- Department of Oral and Developmental Biology, Harvard School of Dental Medicine, Boston, MA 02215, USA
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38
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Garcia-Miñaur S, Mavrogiannis LA, Rannan-Eliya SV, Hendry MA, Liston WA, Porteous MEM, Wilkie AOM. Parietal foramina with cleidocranial dysplasia is caused by mutation in MSX2. Eur J Hum Genet 2004; 11:892-5. [PMID: 14571277 DOI: 10.1038/sj.ejhg.5201062] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The combination of skull defects in the form of enlarged parietal foramina (PFM) and deficient ossification of the clavicles is known as parietal foramina with cleidocranial dysplasia (PFMCCD). It is considered to be distinct from classical cleidocranial dysplasia (CCD) and is listed as a separate OMIM entry (168550). So far, only two families have been reported and the molecular basis of the disorder is unknown. We present a third family with PFMCCD, comprising four affected individuals in three generations, and demonstrate that a heterozygous tetranucleotide duplication in the MSX2 homeobox gene (505_508dupATTG) segregates with the phenotype. PFMCCD is indeed aetiologically distinct from CCD, which is caused by mutations in the RUNX2 gene, but allelic with isolated PFM, in which MSX2 mutations were previously identified. Our observations highlight the role of MSX2 in clavicular development and the importance of radiological examination of the clavicles in subjects with PFM.
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Affiliation(s)
- Sixto Garcia-Miñaur
- South East Scotland Genetic Service, Western General Hospital, Edinburgh, UK
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39
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Merchant TE, Nguyen L, Nguyen D, Wu S, Hudson MM, Kaste SC. Differential attenuation of clavicle growth after asymmetric mantle radiotherapy. Int J Radiat Oncol Biol Phys 2004; 59:556-61. [PMID: 15145176 DOI: 10.1016/j.ijrobp.2003.11.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2003] [Revised: 11/03/2003] [Accepted: 11/10/2003] [Indexed: 10/26/2022]
Abstract
PURPOSE To determine the effects of 15 Gy on bone growth as a function of time and age by comparing clavicle length before and after asymmetric mantle irradiation in pediatric patients. METHODS AND MATERIALS We measured the lengths of both clavicles from radiographs made before and after radiotherapy (median follow-up, 39.6 months), in 15 children (median age, 13.3 years) with early-stage Hodgkin's disease treated with combined modality therapy. The intercepts and slopes of regression lines for individual patients were used to form an estimating regression curve for the population. RESULTS The irradiated volume, patient age, and time elapsed after treatment influenced the measured growth. Fully irradiated clavicles grew 1.3 +/- 0.3 cm, significantly less (0.5 cm; p = 0.007) than did the partially irradiated clavicles. The difference between partially and fully irradiated clavicle lengths was statistically significant, regardless of age. Also, the growth rate of partially and fully irradiated clavicles was significantly different between younger (mean age, 9.9 years) and older (mean age, 16.4 years) patients (p = 0.036). CONCLUSION Clavicle growth is vulnerable to radiation doses as low as 15 Gy, and patient age at the time of irradiation influences the growth rate.
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Affiliation(s)
- Thomas E Merchant
- Department of Radiological Sciences, St. Jude Children's Research Hospital, Memphis, TN 38105-2794, USA.
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40
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Conover CA, Bale LK, Overgaard MT, Johnstone EW, Laursen UH, Füchtbauer EM, Oxvig C, van Deursen J. Metalloproteinase pregnancy-associated plasma protein A is a critical growth regulatory factor during fetal development. Development 2004; 131:1187-94. [PMID: 14973274 DOI: 10.1242/dev.00997] [Citation(s) in RCA: 208] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Pregnancy-associated plasma protein A (PAPPA) is a metzincin superfamily metalloproteinase in the insulin-like growth factor (IGF) system. PAPPA increases IGF bioavailability and mitogenic effectiveness in vitro through regulated cleavage of IGF-binding protein 4 (IGFBP4). To determine its function in vivo, we generated PAPPA-null mice by gene targeting. Mice homozygous for targeted disruption of the PAPPA gene were viable but 60% the size of wild-type littermates at birth. The impact of the mutation was exerted during the early embryonic period prior to organogenesis, resulting in proportional dwarfism. PAPPA, IGF2 and IGFBP4 transcripts co-localized in wild-type embryos, and expression of IGF2 and IGFBP4 mRNA was not altered in PAPPA-deficient embryos. However,IGFBP4 proteolytic activity was completely lacking in fibroblasts derived from PAPPA-deficient embryos, and IGFBP4 effectively inhibited IGF-stimulated mitogenesis in these cells. These results provide the first direct evidence that PAPPA is an essential growth regulatory factor in vivo, and suggest a novel mechanism for regulated IGF bioavailability during early fetal development.
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Affiliation(s)
- Cheryl A Conover
- The Division of Endocrinology, Metabolism and Nutrition, Endocrine Research Unit, Mayo Clinic and Mayo Foundation, 200 First Street SW, Rochester, MN 55905, USA.
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41
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Zou SJ, D'Souza RN, Ahlberg T, Bronckers ALJJ. Tooth eruption and cementum formation in the Runx2/Cbfa1 heterozygous mouse. Arch Oral Biol 2003; 48:673-7. [PMID: 12888002 DOI: 10.1016/s0003-9969(03)00135-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Cleidocranial dysplasia (CCD) is an autosomal dominant human disorder that affects development of bones and teeth. The dental disorders in CCD patients include formation of supernumerary teeth, delayed tooth eruption, and lack of formation of cellular cementum in permanent teeth. This disorder involves a mutation in the osteoblast-specific transcription factor Runx2/Cbfa1, leading to haploinsufficiency of the Runx2/Cbfa1 protein. Here, we examined if Runx2/Cbfa1 heterozygous mice (with one functional allele for Runx2/Cbfa1) exhibit similar changes in tooth eruption, and dental cementum formation as in CCD patients. Heads of Runx2/Cbfa1 heterogeneous and wildtype mice aged days 16-35 postnatally were serially sectioned and stained with hematoxylin-eosin or for tartrate resistant acid phosphatase (TRAP) to identify osteoclasts. The results showed that the eruption pattern of the first and second molars in maxilla and mandible in Runx2/Cbfa1 +/- mice was the same as in wildtype animals. No clear difference in distribution or in the (estimated) number of osteoclasts was found. Cellular cement at the apical portions of the molar roots was present in both groups. The data suggests that in the mouse one allele for Runx2/Cbfa1 is sufficient for an undisturbed tooth eruption and an apparently normal formation of the periodontium.
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Affiliation(s)
- S J Zou
- Department of Oral Cell Biology, ACTA, van der Boechorststr 7, 1081 BT Amsterdam, The Netherlands
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42
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Kornak U, Mundlos S. Genetic disorders of the skeleton: a developmental approach. Am J Hum Genet 2003; 73:447-74. [PMID: 12900795 PMCID: PMC1180673 DOI: 10.1086/377110] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2003] [Accepted: 05/22/2003] [Indexed: 01/07/2023] Open
Abstract
Although disorders of the skeleton are individually rare, they are of clinical relevance because of their overall frequency. Many attempts have been made in the past to identify disease groups in order to facilitate diagnosis and to draw conclusions about possible underlying pathomechanisms. Traditionally, skeletal disorders have been subdivided into dysostoses, defined as malformations of individual bones or groups of bones, and osteochondrodysplasias, defined as developmental disorders of chondro-osseous tissue. In light of the recent advances in molecular genetics, however, many phenotypically similar skeletal diseases comprising the classical categories turned out not to be based on defects in common genes or physiological pathways. In this article, we present a classification based on a combination of molecular pathology and embryology, taking into account the importance of development for the understanding of bone diseases.
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Affiliation(s)
- Uwe Kornak
- Institute for Medical Genetics, Charité University Hospital, Campus Virchow, Berlin, Germany
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Weston AD, Hoffman LM, Underhill TM. Revisiting the role of retinoid signaling in skeletal development. BIRTH DEFECTS RESEARCH. PART C, EMBRYO TODAY : REVIEWS 2003; 69:156-73. [PMID: 12955859 DOI: 10.1002/bdrc.10010] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Several years ago, it was discovered that an imbalance of vitamin A during embryonic development has dramatic teratogenic effects. These effects have since been attributed to vitamin A's most active metabolite, retinoic acid (RA), which itself profoundly influences the development of multiple organs including the skeleton. After decades of study, researchers are still uncovering the molecular basis whereby retinoids regulate skeletal development. Retinoid signaling involves several components, from the enzymes that control the synthesis and degradation of RA, to the cytoplasmic RA-binding proteins, and the nuclear receptors that modulate gene transcription. As new functions for each component continue to be discovered, their developmental roles appear increasingly complex. Interestingly, each component has been implicated in skeletal development. Moreover, retinoid signaling comes into play at distinct stages throughout the developmental sequence of skeletogenesis, highlighting a fundamental role for this pathway in forming the adult skeleton. Consistent with these roles, manipulation of the retinoid signaling pathway significantly affects the expression of the skeletogenic master regulatory factors, Sox9 and Cbfa1. In addition to the fact that we now have a greater understanding of the retinoid signaling pathway on a molecular level, much more information is now available to begin placing retinoid signaling within the context of other factors that regulate skeletogenesis. Here we review these recent advances and describe our current understanding of how retinoid signaling functions to coordinate skeletal development. We also discuss future directions and clinical implications in this field.
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Abstract
For decades, the understanding of craniofacial development has been a central issue in odontology and developmental biology. As a consequence, a significant number of deformities are being studied for their variety of genotype and phenotype. Although there is little doubt about the essential roles of homeobox genes, transcription factors, and growth factors, we now know at least the fundamental strategy of craniofacial biology. The tooth as an organ performs a whole range of functions, each of which is truly indispensable for the maintenance of life. The possession of teeth is, therefore, obviously coupled with the complication of the natural structure of an individual organism. In the following, we shall focus on a brief history of tooth studies and some suggestions for obtaining a full understanding of teeth in the future.
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Affiliation(s)
- Han-Sung Jung
- Department of Oral Biology, College of Dentistry, Institute of Life Science and Biotechnology, Brain Korea 21 Project of Medical Sciences, Yonsei University, Seoul, Korea.
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Grossmann M, Sánchez-Villagra MR, Maier W. On the development of the shoulder girdle in Crocidura russula (Soricidae) and other placental mammals: evolutionary and functional aspects. J Anat 2002; 201:371-81. [PMID: 12448772 PMCID: PMC1570975 DOI: 10.1046/j.0021-8782.2002.00105.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/02/2002] [Indexed: 11/20/2022] Open
Abstract
The development of the shoulder girdle was studied in embryonic stages and a neonate of Crocidura russula using histological sections and 3-D reconstructions. Neonatal stages of Suncus etruscus and Mesocricetus auratus, both altricial placentals, were also studied. The earliest stage of C russula, in which the scapula is still partially blastematous, has already a supraspinous fossa. The dorsal portion of the scapular spine does not develop from the anterior margin of the scapula. Its mode of development varies among the placentals studied to date. In some it is completely appositional bone, in others it consists of bone formed mostly by endochondral ossification of a dorsal cartilaginous process stemming from the acromium. During development the supraspinatus muscle increases in size in proportion to the infraspinatus muscle and the humeral head increases in size in relation to the glenoid fossa. Placentals have secondary cartilage in the sternal and acromial ends of the clavicle, a derived feature absent in Marsupialia. Even the most altricial placentals have a more developed shoulder girdle at birth than any newborn marsupial studied to date.
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Affiliation(s)
- Martin Grossmann
- Zoologisches Institut Spezielle Zoologie, Universität Tübingen, Germany
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46
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Wang WF, Wang YG, Reginato AM, Plotkina S, Gridley T, Olsen BR. Growth defect in Grg5 null mice is associated with reduced Ihh signaling in growth plates. Dev Dyn 2002; 224:79-89. [PMID: 11984876 DOI: 10.1002/dvdy.10089] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Gene-targeted disruption of Grg5, a mouse homologue of Drosophila groucho (gro), results in postnatal growth retardation in mice. The growth defect, most striking in approximately half of the Grg5 null mice, occurs during the first 4-5 weeks of age, but most mice recover retarded growth later. We used the nonlinear mixed-effects model to fit the growth data of wild-type, heterozygous, and Grg5 null mice. On the basis of preliminary evidence suggesting an interaction between Grg5 and the transcription factor Cbfa1/Runx2, critical for skeletal development, we further investigated the skeleton in the mice. A long bone growth plate defect was identified, which included shorter zones of proliferative and hypertrophic chondrocytes and decreased trabecular bone formation. This decreased trabecular bone formation is likely caused by a reduced recruitment of osteoblasts into the growth plate region of Grg5 null mice. Like the growth defect, the growth plate and trabecular bone abnormality improved as the mice grew older. The growth plate defect was associated with reduced Indian hedgehog expression and signaling. We suggest that Grg5, a transcriptional coregulator, modulates the activities of transcription factors, such as Cbfa1/Runx2 in vivo to affect Ihh expression and the function of long bone growth plates.
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Affiliation(s)
- Wen-Fang Wang
- Department of Cell Biology, Harvard Medical School, and Harvard-Forsyth Department of Oral Biology, Harvard School of Dental Medicine, Boston, Massachusetts
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Abstract
Runx2/Cbfa1 plays a central role in skeletal development as demonstrated by the absence of osteoblasts/bone in mice with inactivated Runx2/Cbfa1 alleles. To further investigate the role of Runx2 in cartilage differentiation and to assess the potential of Runx2 to induce bone formation, we cloned chicken Runx2 and overexpressed it in chick embryos using a retroviral system. Infected chick wings showed multiple phenotypes consisting of (1) joint fusions, (2) expansion of carpal elements, and (3) shortening of skeletal elements. In contrast, bone formation was not affected. To investigate the function of Runx2/Cbfa1 during cartilage development, we have generated transgenic mice that express a dominant negative form of Runx2 in cartilage. The selective inactivation of Runx2 in chondrocytes results in a severe shortening of the limbs due to a disturbance in chondrocyte differentiation, vascular invasion, osteoclast differentiation, and periosteal bone formation. Analysis of the growth plates in transgenic mice and in chick limbs shows that Runx2 is a positive regulator of chondrocyte differentiation and vascular invasion. The results further indicate that Runx2 promotes chondrogenesis either by maintaining or by initiating early chondrocyte differentiation. Furthermore, Runx2 is essential but not sufficient to induce osteoblast differentiation. To analyze the role of runx genes in skeletal development, we performed in situ hybridization with Runx2- and Runx3-specific probes. Both genes were coexpressed in cartilaginous condensations, indicating a cooperative role in the regulation of early chondrocyte differentiation and thus explaining the expansion/maintenance of cartilage in the carpus and joints of infected chick limbs.
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Affiliation(s)
- Sigmar Stricker
- Max-Planck-Institut für Molekulare Genetik, Charité, Berlin, Germany
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48
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Zelzer E, McLean W, Ng YS, Fukai N, Reginato AM, Lovejoy S, D'Amore PA, Olsen BR. Skeletal defects in VEGF120/120 mice reveal multiple roles for VEGF in skeletogenesis. Development 2002; 129:1893-904. [PMID: 11934855 DOI: 10.1242/dev.129.8.1893] [Citation(s) in RCA: 284] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Angiogenesis is an essential component of skeletal development and VEGF signaling plays an important if not pivotal role in this process. Previous attempts to examine the roles of VEGF in vivo have been largely unsuccessful because deletion of even one VEGF allele leads to embryonic lethality before skeletal development is initiated. The availability of mice expressing only the VEGF120 isoform (which do survive to term) has offered an opportunity to explore the function of VEGF during embryonic skeletal development. Our study of these mice provides new in vivo evidence for multiple important roles of VEGF in both endochondral and intramembranous bone formation, as well as some insights into isoform-specific functions. There are two key differences in vascularization of developing bones between wild-type and VEGF120/120 mice. VEGF120/120 mice have not only a delayed recruitment of blood vessels into the perichondrium but also show delayed invasion of vessels into the primary ossification center, demonstrating a significant role of VEGF at both an early and late stage of cartilage vascularization. These findings are the basis for a two-step model of VEGF-controlled vascularization of the developing skeleton, a hypothesis that is supported by the new finding that VEGF is expressed robustly in the perichondrium and surrounding tissue of cartilage templates of future bones well before blood vessels appear in these regions. We also describe new in vivo evidence for a possible role of VEGF in chondrocyte maturation, and document that VEGF has a direct role in regulating osteoblastic activity based on in vivo evidence and organ culture experiments.
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Affiliation(s)
- Elazar Zelzer
- Harvard Medical School, Department of Cell Biology, 240 Longwood Avenue, Boston, MA, USA
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49
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Gong Y, Slee RB, Fukai N, Rawadi G, Roman-Roman S, Reginato AM, Wang H, Cundy T, Glorieux FH, Lev D, Zacharin M, Oexle K, Marcelino J, Suwairi W, Heeger S, Sabatakos G, Apte S, Adkins WN, Allgrove J, Arslan-Kirchner M, Batch JA, Beighton P, Black GC, Boles RG, Boon LM, Borrone C, Brunner HG, Carle GF, Dallapiccola B, De Paepe A, Floege B, Halfhide ML, Hall B, Hennekam RC, Hirose T, Jans A, Jüppner H, Kim CA, Keppler-Noreuil K, Kohlschuetter A, LaCombe D, Lambert M, Lemyre E, Letteboer T, Peltonen L, Ramesar RS, Romanengo M, Somer H, Steichen-Gersdorf E, Steinmann B, Sullivan B, Superti-Furga A, Swoboda W, van den Boogaard MJ, Van Hul W, Vikkula M, Votruba M, Zabel B, Garcia T, Baron R, Olsen BR, Warman ML. LDL receptor-related protein 5 (LRP5) affects bone accrual and eye development. Cell 2001; 107:513-23. [PMID: 11719191 DOI: 10.1016/s0092-8674(01)00571-2] [Citation(s) in RCA: 1568] [Impact Index Per Article: 68.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
In humans, low peak bone mass is a significant risk factor for osteoporosis. We report that LRP5, encoding the low-density lipoprotein receptor-related protein 5, affects bone mass accrual during growth. Mutations in LRP5 cause the autosomal recessive disorder osteoporosis-pseudoglioma syndrome (OPPG). We find that OPPG carriers have reduced bone mass when compared to age- and gender-matched controls. We demonstrate LRP5 expression by osteoblasts in situ and show that LRP5 can transduce Wnt signaling in vitro via the canonical pathway. We further show that a mutant-secreted form of LRP5 can reduce bone thickness in mouse calvarial explant cultures. These data indicate that Wnt-mediated signaling via LRP5 affects bone accrual during growth and is important for the establishment of peak bone mass.
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MESH Headings
- Adaptor Proteins, Signal Transducing
- Adult
- Animals
- Animals, Outbred Strains
- Bone Density/genetics
- Bone Morphogenetic Protein 2
- Bone Morphogenetic Proteins/pharmacology
- COS Cells
- Child
- Child, Preschool
- Chlorocebus aethiops
- Chromosomes, Human, Pair 11/genetics
- Culture Media, Conditioned/pharmacology
- DNA, Complementary/genetics
- Dishevelled Proteins
- Eye/embryology
- Eye Abnormalities/genetics
- Female
- Genes, Recessive
- Heterozygote
- Humans
- LDL-Receptor Related Proteins
- Low Density Lipoprotein Receptor-Related Protein-5
- Male
- Mesoderm/cytology
- Mice
- Mice, Inbred C57BL
- Organ Culture Techniques
- Osteoblasts/metabolism
- Osteoporosis/genetics
- Phosphoproteins/genetics
- Phosphoproteins/physiology
- Proteins/genetics
- Proteins/physiology
- Proto-Oncogene Proteins/genetics
- Proto-Oncogene Proteins/physiology
- Receptors, LDL/deficiency
- Receptors, LDL/genetics
- Receptors, LDL/physiology
- Recombinant Fusion Proteins/physiology
- Recombinant Proteins
- Signal Transduction
- Skull/cytology
- Species Specificity
- Stromal Cells/cytology
- Stromal Cells/drug effects
- Syndrome
- Transfection
- Transforming Growth Factor beta
- Wnt Proteins
- Wnt-5a Protein
- Wnt2 Protein
- Wnt3 Protein
- Wnt4 Protein
- Zebrafish Proteins
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Bergwitz C, Prochnau A, Mayr B, Kramer FJ, Rittierodt M, Berten HL, Hausamen JE, Brabant G. Identification of novel CBFA1/RUNX2 mutations causing cleidocranial dysplasia. J Inherit Metab Dis 2001; 24:648-56. [PMID: 11768584 DOI: 10.1023/a:1012758925617] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Core binding factor A1 (CBFA1/RUNX2) is a runt-like transcription factor essential for osteoblast differentiation. Haplotype insufficiency causes cleidocranial dysplasia (CCD), a syndrome featuring supernumerary tooth buds, delayed tooth eruption, patent fontanels, Wormian bones, short stature, dysplasia of the clavicles, growth retardation and hypoplasia of the distal phalanges. We identified novel CBFAI/RUNX2 mutations after PCR and direct sequencing of patient leukocyte DNA. In family 1 mother and son are affected by CCD. Both carry the missense mutation R190W (CGG > TGG). This nucleotide change introduced a BsmI restriction site, which was used to independently confirm the mutation. It was absent in healthy members of the family. Family 2, in which father and daughter are affected by CCD, shows a deletion of nucleotide C821. This deletion causes a frameshift mutation with premature stop after the insertion of 18 aberrant amino acids. Healthy family members did not have this mutation. The clavicular dysplasia was more pronounced with the R19OW mutation, while the bone density was markedly reduced in individuals with either mutation, suggesting a previously underemphasized increased risk for osteoporosis in CCD.
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Affiliation(s)
- C Bergwitz
- Abteilung für Klinische Endokrinologie, Hochschule Hannover, Germany.
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