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Wang J, Huang X, Lai C, Jiang K. Clinical spectrum of cleidocranial dysplasia in a family with twins. Pediatr Int 2013; 55:392-5. [PMID: 23782374 DOI: 10.1111/ped.12043] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2011] [Revised: 08/07/2012] [Accepted: 10/10/2012] [Indexed: 11/27/2022]
Abstract
Cleidocranial dysplasia (CCD) is a rare congenital defect of autosomal dominant inheritance, primarily affecting bones that undergo intra-membranous ossification. Herein is reported the case of monozygotic male 13-year-old twins with typical features of this syndrome, such as large wide-open fontanels, abnormal clavicles with narrow, sloping shoulders that can be apposed at the midline, short stature, mid-face hypoplasia, multiple supernumerary teeth, and skeletal anomalies. Their physical appearance led to the diagnosis of CCD. Genetic analysis found a C-T exchange in exon 2 at cDNA position 568, which changes the codon CGG for arginine to TGG for tryptophan (R190W) of the runt-related transcription factor 2 RUNX2 gene. CCD should be suspected in patients with persistence of the widely open anterior fontanels and sutures, short stature, and poor clavicles, calvarium, or teeth. Timely recognition and hereditary tendency counseling is required and useful because of the possibility of covert transmissibility and sporadic genetic mutation.
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Affiliation(s)
- Jiangping Wang
- Department of Rehabilitation, Zhejiang University School of Medicine, Hangzhou, China
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102
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Anthonappa RP, King NM, Mahmoud Rabie AB. RUNX2 gene status in a cleidocranial dysplasia patient without supernumerary teeth. ACTA ACUST UNITED AC 2012. [PMID: 23188595 DOI: 10.1111/jicd.12019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
OBJECTIVE This study sought to perform mutational analysis of the RUNX2 gene in an 8-year-old girl with a diagnosis of cleidocranial dysplasia (CCD) without supernumerary teeth (proband) and her parents, plus in age and gender matched control subjects. METHODS Ethical approval and informed consent was obtained for this study. Blood samples were obtained and the isolated DNA was used to amplify exons 0-7 of the RUNX2 gene using specific primers, which was subsequently sequenced. RESULTS No mutations were identified in the coding regions of the RUNX2 gene. CONCLUSION The absence of supernumerary teeth in this individual with CCD demonstrates that there are variations in the phenotypes and mere absence of mutations does not imply that CCD phenotype is not governed by RUNX2 gene as only two-thirds of the individuals exhibiting a CCD phenotype would reveal a RUNX2 mutation; therefore, the influence of copy number variations including large insertions, intragenic deletions, duplications, and inversions of genes cannot be excluded completely.
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Affiliation(s)
- Robert P Anthonappa
- Paediatric Dentistry, School of Dentistry, The University of Western Australia, Perth, Australia.
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103
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Influence of BONITmatrix® and OSSA NOVA on the expression of bone specific genes. Ann Anat 2012; 194:524-8. [DOI: 10.1016/j.aanat.2012.02.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Revised: 02/08/2012] [Accepted: 02/20/2012] [Indexed: 11/17/2022]
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104
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Dorotheou D, Gkantidis N, Karamolegkou M, Kalyvas D, Kiliaridis S, Kitraki E. Tooth eruption: altered gene expression in the dental follicle of patients with cleidocranial dysplasia. Orthod Craniofac Res 2012; 16:20-7. [PMID: 23311656 DOI: 10.1111/ocr.12000] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVES The dental follicle plays an important role in tooth eruption by providing key regulators of osteogenesis and bone resorption. Patients with cleidocranial dysplasia (CCD) exhibit delayed tooth eruption in combination with increased bone density in the maxilla and mandible, suggesting disturbances in bone remodeling. The aim of this study was to determine the expression of genes relevant for tooth eruption and bone remodeling in the dental follicles of patients with CCD and normal subjects. MATERIAL AND METHODS Thirteen dental follicles were isolated from five unrelated patients with CCD, and fourteen dental follicles were obtained from 10 healthy individuals. All teeth were in the intraosseous phase of eruption. The expression of RANK, RANKL, OPG, and CSF-1 was determined by quantitative RT-PCR. RESULTS In patients with CCD, the mRNA levels of RANK, OPG, and CSF-1 were significantly elevated compared with the control group. Accordingly, the ratios of RANKL/OPG and RANKL/RANK mRNAs were significantly decreased in patients with CCD. CONCLUSION The observed alterations in the expression and ratios of the aforementioned factors in the dental follicle of CCD individuals suggest a disturbed paracrine signaling for bone remodeling that could be responsible for the impaired tooth eruption seen in these patients.
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Affiliation(s)
- D Dorotheou
- Department of Orthodontics, School of Dentistry, University of Geneva, Geneva, Switzerland.
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105
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Toro B, Pérez A, Fierro C. Disostosis cleidocraneal: Revisión bibliográfica a propósito de un caso clínico. JOURNAL OF ORAL RESEARCH 2012. [DOI: 10.17126/joralres.2012.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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106
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Liang B, Cotter MM, Chen D, Hernandez CJ, Zhou G. Ectopic expression of SOX9 in osteoblasts alters bone mechanical properties. Calcif Tissue Int 2012; 90:76-89. [PMID: 22143895 PMCID: PMC3272153 DOI: 10.1007/s00223-011-9550-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2010] [Accepted: 11/11/2011] [Indexed: 12/28/2022]
Abstract
Osteoporosis is a common skeletal disease characterized by low bone mass and microarchitectural deterioration of bone tissue, with a consequent increase in bone fragility and susceptibility to fracture. We previously demonstrated that Col1a1-SOX9 transgenic (TG) mice, in which SOX9 specifically expresses in osteoblasts driven by a 2.3-kb Col1a1 promoter, display osteopenia during the early postnatal stage. In this study, to further analyze the osteopenia phenotype and especially the effect of the osteoblast-specific expression of SOX9 on bone mechanical properties, we performed bone geometry and mechanical property analysis of long bones from Col1a1-SOX9 TG mice and wild-type littermates (WT) at different time points. Interestingly, after body weight adjustment, TG mice had similar whole-bone strength as WT mice but significantly thinner cortical bone, lower elastic modulus, and higher moment of inertia. Thus, osteoblast-specific SOX9 expression results in altered bone structure and material properties. Furthermore, the expression levels of Pcna, Col1a1, osteocalcin, and the Opg/Rankl ratio in TG mice were significantly lower until 4 months of age compared with WT mice, suggesting that TG mice have dysregulated bone homeostasis. Finally, bone marrow stromal cells (MSCs) isolated from TG mice display enhanced adipocyte differentiation and decreased osteoblast differentiation in vitro, suggesting that osteoblast-specific expression of SOX9 can lead to altered mesenchymal stem cell differentiation potentials. In conclusion, our study implies that SOX9 activity has to be tightly regulated in the adult skeleton to ensure optimal bone quality.
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Affiliation(s)
- Bojian Liang
- Department of Orthopaedics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, U. S. A
| | - Meghan M. Cotter
- Department of Anatomy, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, U. S. A
| | - Dongxing Chen
- Department of Orthopaedics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, U. S. A
| | - Christopher J. Hernandez
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY 14853, U.S.A
| | - Guang Zhou
- Department of Orthopaedics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, U. S. A
- Department of Genetics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, U. S. A
- Case Comprehensive Cancer Center, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, U. S. A
- Corresponding author: Guang Zhou, Ph.D., Department of Orthopaedics, BRB, Room 328, Case Western Reserve University, 2109 Adelbert Road, Cleveland, OH 44106, U. S. A., Tel: (216) 368-2260, Fax: (216) 368-1332,
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107
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Henriquez B, Hepp M, Merino P, Sepulveda H, van Wijnen AJ, Lian JB, Stein GS, Stein JL, Montecino M. C/EBPβ binds the P1 promoter of the Runx2 gene and up-regulates Runx2 transcription in osteoblastic cells. J Cell Physiol 2011; 226:3043-52. [PMID: 21302301 DOI: 10.1002/jcp.22652] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The Runx2 factor is an essential component of the regulatory mechanisms that control transcription during skeletogenesis. Runx2/p57 expression in osteoblastic cells is controlled by the P1 promoter, which is recognized by key regulators of osteoblast differentiation including homeodomain factors and Wnt- and BMP-signaling mediators. Here, we report that the transcription factor C/EBPβ up-regulates Runx2/p57 expression by directly binding to the Runx2 P1 promoter in mesenchymal, pre-osteoblastic, and osteoblastic cells. This C/EBPβ-mediated up-regulation is principally dependent on C/EBP site II that is located within the first 180 bp of the proximal P1 promoter region and is highly conserved among mouse, rat, and human Runx2 genes. Our studies reveal how the C/EBPβ factor, known to have a key role during osteogenesis, contributes to regulating the expression of Runx2, the master regulator of osteoblast differentiation.
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Affiliation(s)
- Berta Henriquez
- Faculty of Biological Sciences, Center for Biomedical Research, Andres Bello University, Santiago, Chile
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108
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Inoue KI, Ito Y. Neuroblastoma cell proliferation is sensitive to changes in levels of RUNX1 and RUNX3 protein. Gene 2011; 487:151-5. [DOI: 10.1016/j.gene.2011.05.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Revised: 05/16/2011] [Accepted: 05/17/2011] [Indexed: 12/12/2022]
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109
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Bufalino A, Paranaíba LMR, Gouvêa AF, Gueiros LA, Martelli-Júnior H, Junior JJ, Lopes MA, Graner E, De Almeida OP, Vargas PA, Coletta RD. Cleidocranial dysplasia: oral features and genetic analysis of 11 patients. Oral Dis 2011; 18:184-90. [PMID: 22023169 DOI: 10.1111/j.1601-0825.2011.01862.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Cleidocranial dysplasia (CCD) is a dominantly inherited autosomal disease characterized by typical bone defects including short stature, persistently open or delayed closure of the cranial sutures, and hypoplastic or aplastic clavicles. Oral features are frequent and include supernumerary teeth, delayed eruption or impaction of the permanent teeth, and malocclusion. Heterozygous mutations in RUNX2 gene, which encodes a transcription factor essential for osteoblast differentiation, were identified as the etiological cause of CCD. OBJECTIVE AND METHODS Herein, we performed physical and radiographic examination and screening for RUNX2 mutations in 11 patients from five families with CCD. RESULTS All patients demonstrated the classical phenotypes related to CCD. Families whose affected members had several dental alterations such as multiple impacted and supernumerary teeth demonstrated heterozygous missense mutations (R190Q and R225Q) that impair the runt domain of RUNX2. On the other hand, CCD patients from families with low frequency of dental abnormalities showed no mutation in RUNX2 or mutation outside of the runt domain (Q292fs→X299). CONCLUSION The current findings suggest a correlation between dental alterations and mutations in the runt domain of RUNX2 in CCD patients. Further clinical and genetic studies are needed to clarify the relationship between phenotypes and genotypes in CCD and to identify other factors that might influence the clinical features of this uncommon disease.
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Affiliation(s)
- A Bufalino
- Department of Oral Diagnosis, School of Dentistry, State University of Campinas, Piracicaba, São Paulo, Brazil
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110
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The ability of MLL to bind RUNX1 and methylate H3K4 at PU.1 regulatory regions is impaired by MDS/AML-associated RUNX1/AML1 mutations. Blood 2011; 118:6544-52. [PMID: 22012064 DOI: 10.1182/blood-2010-11-317909] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The mixed-lineage leukemia (MLL) H3K4 methyltransferase protein, and the heterodimeric RUNX1/CBFβ transcription factor complex, are critical for definitive and adult hematopoiesis, and both are frequently targeted in human acute leukemia. We identified a physical and functional interaction between RUNX1 (AML1) and MLL and show that both are required to maintain the histone lysine 4 trimethyl mark (H3K4me3) at 2 critical regulatory regions of the AML1 target gene PU.1. Similar to CBFβ, we show that MLL binds to AML1 abrogating its proteasome-dependent degradation. Furthermore, a subset of previously uncharacterized frame-shift and missense mutations at the N terminus of AML1, found in MDS and AML patients, impairs its interaction with MLL, resulting in loss of the H3K4me3 mark within PU.1 regulatory regions, and decreased PU.1 expression. The interaction between MLL and AML1 provides a mechanism for the sequence-specific binding of MLL to DNA, and identifies RUNX1 target genes as potential effectors of MLL function.
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111
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Doetschman T, Barnett JV, Runyan RB, Camenisch TD, Heimark RL, Granzier HL, Conway SJ, Azhar M. Transforming growth factor beta signaling in adult cardiovascular diseases and repair. Cell Tissue Res 2011; 347:203-23. [PMID: 21953136 DOI: 10.1007/s00441-011-1241-3] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Accepted: 09/02/2011] [Indexed: 01/15/2023]
Abstract
The majority of children with congenital heart disease now live into adulthood due to the remarkable surgical and medical advances that have taken place over the past half century. Because of this, adults now represent the largest age group with adult cardiovascular diseases. It includes patients with heart diseases that were not detected or not treated during childhood, those whose defects were surgically corrected but now need revision due to maladaptive responses to the procedure, those with exercise problems and those with age-related degenerative diseases. Because adult cardiovascular diseases in this population are relatively new, they are not well understood. It is therefore necessary to understand the molecular and physiological pathways involved if we are to improve treatments. Since there is a developmental basis to adult cardiovascular disease, transforming growth factor beta (TGFβ) signaling pathways that are essential for proper cardiovascular development may also play critical roles in the homeostatic, repair and stress response processes involved in adult cardiovascular diseases. Consequently, we have chosen to summarize the current information on a subset of TGFβ ligand and receptor genes and related effector genes that, when dysregulated, are known to lead to cardiovascular diseases and adult cardiovascular deficiencies and/or pathologies. A better understanding of the TGFβ signaling network in cardiovascular disease and repair will impact genetic and physiologic investigations of cardiovascular diseases in elderly patients and lead to an improvement in clinical interventions.
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112
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Abstract
Bone is specific to vertebrates, and originated as mineralization around the basal membrane of the throat or skin, giving rise to tooth-like structures and protective shields in animals with a soft cartilage-like endoskeleton. A combination of fossil anatomy and genetic information from modern species has improved our understanding of the evolution of bone. Thus, even in man, there are still similarities in the molecular regulation of skin appendages and bone. This article gives a brief overview of the major milestones in skeletal evolution. Some molecular machineries involving members of core genetic networks and their interactions are described in the context of both old theories and modern genetic approaches.
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Affiliation(s)
| | - Per Aspenberg
- Orthopedics, AIR/IKE, Faculty of Health Science, Linköping University, Linköping, Sweden
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113
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Haley KJ, Lasky-Su J, Manoli SE, Smith LA, Shahsafaei A, Weiss ST, Tantisira K. RUNX transcription factors: association with pediatric asthma and modulated by maternal smoking. Am J Physiol Lung Cell Mol Physiol 2011; 301:L693-701. [PMID: 21803869 DOI: 10.1152/ajplung.00348.2010] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Intrauterine smoke exposure (IUS) is a strong risk factor for development of airways responsiveness and asthma in childhood. Runt-related transcription factors (RUNX1-3) have critical roles in immune system development and function. We hypothesized that genetic variations in RUNX1 would be associated with airway responsiveness in asthmatic children and that this association would be modified by IUS. Family-based association testing analysis in the Childhood Asthma Management Program genome-wide genotype data showed that 17 of 100 RUNX1 single-nucleotide polymorphisms (SNPs) were significantly (P < 0.03-0.04) associated with methacholine responsiveness. The association between methacholine responsiveness and one of the SNPs was significantly modified by a history of IUS exposure. Quantitative PCR analysis of immature human lung tissue with and without IUS suggested that IUS increased RUNX1 expression at the pseudoglandular stage of lung development. We examined these associations by subjecting murine neonatal lung tissue with and without IUS to quantitative PCR (N = 4-14 per group). Our murine model showed that IUS decreased RUNX expression at postnatal days (P)3 and P5 (P < 0.05). We conclude that 1) SNPs in RUNX1 are associated with airway responsiveness in asthmatic children and these associations are modified by IUS exposure, 2) IUS tended to increase the expression of RUNX1 in early human development, and 3) a murine IUS model showed that the effects of developmental cigarette smoke exposure persisted for at least 2 wk after birth. We speculate that IUS exposure-altered expression of RUNX transcription factors increases the risk of asthma in children with IUS exposure.
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Affiliation(s)
- Kathleen J Haley
- Brigham and Women's Hospital, Division of Pulmonary and Critical Care Medicine, PBB-3, 75 Francis St., Boston, Massachusetts 02115, USA.
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114
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Chen Y, Wei X, Guo C, Jin H, Han Z, Han Y, Qiao T, Wu K, Fan D. Runx3 suppresses gastric cancer metastasis through inactivation of MMP9 by upregulation of TIMP-1. Int J Cancer 2011; 129:1586-98. [PMID: 21128246 DOI: 10.1002/ijc.25831] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Accepted: 11/04/2010] [Indexed: 01/09/2023]
Abstract
Recent studies have suggested that loss of RUNX3 expression is involved with gastric tumor metastasis. However, the precise mechanism of RUNX3-mediated suppression of tumor metastasis remains elusive. We aimed to clarify the effect of RUNX3 on tumor metastasis in gastric cancer cell lines and tumors. Immunohistochemistry revealed that RUNX3 was significantly decreased in metastatic gastric cancer. Gelatin zymography and Western blot showed that instead of regulating matrix metalloproteinase 9 (MMP9) expression, RUNX3 expression inhibited MMP9 enzyme activity, and this was consistent with the upregulation of tissue inhibitor of metalloproteinases 1 (TIMP1) by RUNX3. TIMP1 siRNA treatment impaired RUNX3-mediated suppression of gastric cancer cell invasion. Reporter assays demonstrated regulation of TIMP-1 by RUNX3. Two RUNX3 binding sites were identified in the TIMP-1 promoter and direct interaction of RUNX3 with the TIMP-1 promoter was confirmed in vitro and in vivo. These findings provide evidence for RUNX3-mediated suppression of gastric cancer invasion and metastasis and define a novel molecular mechanism that for the metastasis-inhibiting activity of RUNX3. These data may be applied in the development of RUNX3 for gastric cancer metastasis diagnostics and therapeutics.
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Affiliation(s)
- Yu Chen
- State Key Laboratory of Cancer Biology and Department of Digestive Diseases, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi Province, People's Republic of China
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115
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Liu JC, Lengner CJ, Gaur T, Lou Y, Hussain S, Jones MD, Borodic B, Colby JL, Steinman HA, van Wijnen AJ, Stein JL, Jones SN, Stein GS, Lian JB. Runx2 protein expression utilizes the Runx2 P1 promoter to establish osteoprogenitor cell number for normal bone formation. J Biol Chem 2011; 286:30057-70. [PMID: 21676869 DOI: 10.1074/jbc.m111.241505] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Runt-related transcription factor, Runx2, is essential for osteogenesis and is controlled by both distal (P1) and proximal (P2) promoters. To understand Runx2 function requires determination of the spatiotemporal activity of P1 and P2 to Runx2 protein production. We generated a mouse model in which the P1-derived transcript was replaced with a lacZ reporter allele, resulting in loss of P1-derived protein while simultaneously allowing discrimination between the activities of the two promoters. Loss of P1-driven expression causes developmental defects with cleidocranial dysplasia-like syndromes that persist in the postnatal skeleton. P1 activity is robust in preosteogenic mesenchyme and at the onset of bone formation but decreases as bone matures. Homozygous Runx2-P1(lacZ/lacZ) mice have a normal life span but exhibit severe osteopenia and compromised bone repair in adult mice because of osteoblastic defects and not increased osteoclastic resorption. Gene expression profiles of bone, immunohistochemical studies, and ex vivo differentiation using calvarial osteoblasts and marrow stromal cells identified mechanisms for the skeletal phenotype. The findings indicate that P1 promoter activity is necessary for generating a threshold level of Runx2 protein to commit sufficient osteoprogenitor numbers for normal bone formation. P1 promoter function is not compensated via the P2 promoter. However, the P2 transcript with compensatory mechanisms from bone morphogenetic protein (BMP) and Wnt signaling is adequate for mineralization of the bone tissue that does form. We conclude that selective utilization of the P1 and P2 promoters enables the precise spatiotemporal expression of Runx2 necessary for normal skeletogenesis and the maintenance of bone mass in the adult.
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Affiliation(s)
- Julie C Liu
- Department of Cell Biology and Cancer Center, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
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116
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Hansen L, Riis AK, Silahtaroglu A, Hove H, Lauridsen E, Eiberg H, Kreiborg S. RUNX2 analysis of Danish cleidocranial dysplasia families. Clin Genet 2011; 79:254-63. [PMID: 20560987 DOI: 10.1111/j.1399-0004.2010.01458.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Cleidocranial dysplasia (CCD) is an autosomal dominant inherited disease caused by mutations in the Runt gene RUNX2. Screening of 19 Danish CCD families revealed 16 pathogenic mutations (84%) representing 8 missense mutations, 2 nonsense mutations, 4 frame-shift mutations and 2 large deletions in the RUNX2 locus. Eight mutations were novel, two were found twice, and polymorphisms were found in the promoter region and in the conserved polyglutamine/polyalanine repeat. A large duplication downstream of RUNX2 found in one patient suggests a possible regulatory RUNX2 element. The CCD phenotypes and genotypes adhere to the large phenotypic variability reported in previous CCD studies. Identification of large chromosome aberrations in or near the RUNX2 locus in 3 of the 19 cases suggests copy number analyses to be included in future RUNX2 mutation analyses.
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Affiliation(s)
- L Hansen
- Department of Cellular and Molecular Medicine, Panum Institute, University of Copenhagen, Blegdamsvej 3, Copenhagen, Denmark.
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117
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Lin WD, Lin SP, Wang CH, Tsai Y, Chen CP, Tsai FJ. RUNX2 mutations in Taiwanese patients with cleidocranial dysplasia. Genet Mol Biol 2011; 34:201-4. [PMID: 21734816 PMCID: PMC3115309 DOI: 10.1590/s1415-47572011005000002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Accepted: 12/12/2010] [Indexed: 12/29/2022] Open
Abstract
Cleidocranial dysplasia (CCD) is an autosomal dominant human skeletal disorder comprising hypoplastic clavicles, wide cranial sutures, supernumerary teeth, short stature, and other skeletal abnormalities. It is known that mutations in the human RUNX2 gene mapped at 6p21 are responsible for CCD. We analyzed the mutation patterns of the RUNX2 gene by direct sequencing in six Taiwanese index cases with typical CCD. One of the patients was a familial case and the others were sporadic cases. Sequencing identified four mutations. Three were caused by single nucleotide substitutions, which created a nonsense (p.R391X), two were missense mutations (p.R190W, p.R225Q), and the forth was a novel mutation (c.1119delC), a one-base deletion. Real time quantitative PCR adapted to determine copy numbers of the promoter, all exons and the 3’UTR region of the RUNX2 gene detected the deletion of a single allele in a sporadic case. The results extend the spectrum of RUNX2 mutations in CCD patients and indicate that complete deletions of the RUNX2 gene should be considered in those CCD patients lacking a point mutation detected by direct sequencing.
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Affiliation(s)
- Wei-De Lin
- Department of Medical Research, China Medical University Hospital, Taichung, Taiwan
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118
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Wang XP, Fan J. Molecular genetics of supernumerary tooth formation. Genesis 2011; 49:261-77. [PMID: 21309064 DOI: 10.1002/dvg.20715] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2010] [Revised: 01/02/2011] [Accepted: 01/06/2011] [Indexed: 01/07/2023]
Abstract
Despite advances in the knowledge of tooth morphogenesis and differentiation, relatively little is known about the aetiology and molecular mechanisms underlying supernumerary tooth formation. A small number of supernumerary teeth may be a common developmental dental anomaly, while multiple supernumerary teeth usually have a genetic component and they are sometimes thought to represent a partial third dentition in humans. Mice, which are commonly used for studying tooth development, only exhibit one dentition, with very few mouse models exhibiting supernumerary teeth similar to those in humans. Inactivation of Apc or forced activation of Wnt/β(catenin signalling results in multiple supernumerary tooth formation in both humans and in mice, but the key genes in these pathways are not very clear. Analysis of other model systems with continuous tooth replacement or secondary tooth formation, such as fish, snake, lizard, and ferret, is providing insights into the molecular and cellular mechanisms underlying succesional tooth development, and will assist in the studies on supernumerary tooth formation in humans. This information, together with the advances in stem cell biology and tissue engineering, will pave ways for the tooth regeneration and tooth bioengineering.
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Affiliation(s)
- Xiu-Ping Wang
- Department of Developmental Biology, Harvard School of Dental Medicine, Harvard University, Boston, Massachusetts 02115, USA.
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119
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Dalessandri D, Laffranchi L, Tonni I, Zotti F, Piancino MG, Paganelli C, Bracco P. Advantages of cone beam computed tomography (CBCT) in the orthodontic treatment planning of cleidocranial dysplasia patients: a case report. Head Face Med 2011; 7:6. [PMID: 21352577 PMCID: PMC3053235 DOI: 10.1186/1746-160x-7-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Accepted: 02/27/2011] [Indexed: 11/10/2022] Open
Abstract
Our aim was to discuss, by presenting a case, the possibilities connected to the use of a CBCT exam in the dental evaluation of patients with Cleidocranial Dysplasia (CCD), an autosomal dominant skeletal dysplasia with delayed exfoliation of deciduous and eruption of permanent teeth and multiple supernumeraries, often impacted. We think that CBCT in this patient was adequate to accurately evaluate impacted teeth position and anatomy, resulting thus useful both in the diagnostic process and in the treatment planning, with an important reduction in the radiation dose absorbed by the patient.
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Affiliation(s)
- Domenico Dalessandri
- Doctoral School in Medicine and Experimental Therapy, Specialisation in Physiopathology of Mastication and the Stomatognathic Apparatus, Dental Materials, XXIII cycle, Department of Biomedical Sciences and Human Oncology, University of Torino, Italy.
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Lee JS, Lee JM, Im GI. Electroporation-mediated transfer of Runx2 and Osterix genes to enhance osteogenesis of adipose stem cells. Biomaterials 2011; 32:760-8. [PMID: 20947160 DOI: 10.1016/j.biomaterials.2010.09.042] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2010] [Accepted: 09/19/2010] [Indexed: 12/13/2022]
Abstract
In the present study, we tested the hypothesis that electroporation-mediated transfer of Runx2, Osterix, or both genes enhances the in vitro and in vivo osteogenesis from adipose stem cells (ASCs). ASCs were transfected with Runx2, Osterix, or both genes using electroporation, and further cultured in monolayer or in PLGA scaffold under osteogenic medium for 14 days, then analyzed for in vitro osteogenic differentiation. Transfected ASC-PLGA scaffold hybrids were also implanted on nude mice to test for in vivo ectopic bone formation. Runx2 and Osterix genes were strongly expressed in ASCs transfected with each gene on day 7, decreasing rapidly on day 14. Runx2 protein was strongly expressed in ASCs transfected with the Runx2 gene, while Osterix protein was strongly expressed in ASCs transfected with either or both Runx2 and Osterix genes. Overexpression of Runx2 and Osterix significantly increased the gene expression of osteogenic differentiation markers (alkaline phosphatase [ALP], osteocalcin [OCN], type I collagen [COL1A1], and bone sialoprotein [BSP]) in ASCs. Transfection of Runx2 and Osterix genes enhanced the protein expression of OCN, type I collagen, and BSP, as demonstrated by Western blot analysis, and ALP activity as well as enhancing mineralization in the monolayer culture and ASC-PLGA scaffold hybrids. Runx2- or Osterix-transfected ASC-PLGA scaffold hybrids promoted bone formation in nude mice after 6 weeks of in vivo implantation.
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Affiliation(s)
- Jai-Sun Lee
- Department of Orthopaedics, Dongguk University Ilsan Hospital, Goyang, Republic of Korea
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121
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Hesse E, Saito H, Kiviranta R, Correa D, Yamana K, Neff L, Toben D, Duda G, Atfi A, Geoffroy V, Horne WC, Baron R. Zfp521 controls bone mass by HDAC3-dependent attenuation of Runx2 activity. ACTA ACUST UNITED AC 2010; 191:1271-83. [PMID: 21173110 PMCID: PMC3010073 DOI: 10.1083/jcb.201009107] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Runx2 is indispensable for osteoblast lineage commitment and early differentiation but also blocks osteoblast maturation, thereby causing bone loss in Runx2 transgenic mice. Zinc finger protein 521 (Zfp521) antagonizes Runx2 in vivo. Eliminating one Zfp521 allele mitigates the cleidocranial dysplasia-like phenotype of newborn Runx2(+/-) mice, whereas overexpressing Zfp521 exacerbates it. Overexpressing Zfp521 also reverses the severe osteopenia of adult Runx2 transgenic mice. Zfp521 binds to both Runx2 and histone deacetylase 3 (HDAC3), promotes their association, and antagonizes Runx2 transcriptional activity in an HDAC3-dependent manner. Mutating the Zfp521 zinc finger domains 6 and 26 reduces the binding of Zfp521 to Runx2 and inhibition of Runx2 activity. These data provide evidence that Zfp521 antagonizes Runx2 in vivo and thereby regulates two stages of osteoblast development, early during mesenchymal cell lineage commitment and later during osteoblast maturation. Thus, the balance and molecular interplay between Zfp521 and Runx2 contribute to the control of osteoblast differentiation, skeletal development, and bone homeostasis.
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Affiliation(s)
- Eric Hesse
- Department of Medicine, Harvard Medical School, Harvard School of Dental Medicine, Harvard University, Boston, MA 02115, USA
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122
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Marchisella C, Rolando F, Muscarella LA, Zelante L, Bracco P, Piemontese MR. Identification of a novel RUNX2 gene mutation in an Italian family with cleidocranial dysplasia. Eur J Orthod 2010; 33:498-502. [DOI: 10.1093/ejo/cjq107] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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123
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Xuan D, Sun X, Yan Y, Xie B, Xu P, Zhang J. Effect of cleidocranial dysplasia-related novel mutation of RUNX2 on characteristics of dental pulp cells and tooth development. J Cell Biochem 2010; 111:1473-81. [DOI: 10.1002/jcb.22875] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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124
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Kamamoto M, Machida J, Miyachi H, Ono T, Nakayama A, Shimozato K, Tokita Y. A novel mutation in the C-terminal region of RUNX2/CBFA1 distal to the DNA-binding runt domain in a Japanese patient with cleidocranial dysplasia. Int J Oral Maxillofac Surg 2010; 40:434-7. [PMID: 21115325 DOI: 10.1016/j.ijom.2010.09.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2008] [Revised: 05/01/2009] [Accepted: 09/28/2010] [Indexed: 11/28/2022]
Abstract
Cleidocranial dysplasia (CCD) is an autosomal dominant inherited skeletal disease with high penetrance and variable expressivity. Although many mutations in RUNX2/CBFA1, an osteoblast-specific transcription factor, have been identified as causes of CCD, it is unclear whether these mutation genotypes relate to various symptoms. Heterogeneous mutations of RUNX2/CBFA1 result in disease characterized by abnormal skeletal genesis and dental disorders. There are few reports describing the relation between detailed orofacial pathology and the RUNX2/CBFA1 genotype. The case of a Japanese patient with severe orofacial dysplasia who was clinically thought to have CCD is described here. The authors performed mutation analysis on the RUNX2/CBFA1 gene and identified a novel frameshift mutation (722delT), which produces a mutant RUNX2/CBFA1 with a truncating C-terminus distal to the runt domain.
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Affiliation(s)
- M Kamamoto
- Department of Maxillofacial Surgery, Aichi-Gakuin University School of Dentistry, Nagoya, Japan
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125
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Pineda B, Hermenegildo C, Laporta P, Tarín JJ, Cano A, García-Pérez MÁ. Common polymorphisms rather than rare genetic variants of the Runx2 gene are associated with femoral neck BMD in Spanish women. J Bone Miner Metab 2010; 28:696-705. [PMID: 20407796 DOI: 10.1007/s00774-010-0183-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2010] [Accepted: 03/14/2010] [Indexed: 10/19/2022]
Abstract
RUNX2 is a transcription factor essential for osteoblast differentiation and skeletal morphogenesis. Its mutation creates cleidocranial dysplasia (CCD), a disorder characterized by skeletal abnormalities and bone mineral density (BMD) alterations. The purpose of the present study has been to clarify whether polymorphisms affecting this gene could be associated with changes in BMD in women. To that end, we performed an association study of BMD values from 776 women with two single nucleotide polymorphisms (SNPs) located at P2 promoter (-1025 T>C) and at exon 2 (+198 G>A), and with a deletion polymorphism (17Ala>11Ala), also located at exon 2. We found an association of -1025 T>C SNP with femoral neck BMD (FN-BMD), being the women of TC/CC genotype who have higher BMD than women of TT genotype (P = 0.006). This association was independent of age, weight, menopausal status, or hormone replacement therapy (HRT) use as shown by regression analysis. When women of highest versus lowest quartile of BMD were compared, this association became more evident (P = 0.002), extending also to +198 G>A SNP (GA/AA women with higher FN-BMD; P < 0.05). In addition, we describe herein three novel rare variants in the polyglutamine domain of RUNX2 protein: an in-frame insertion and two deletions in exon 2, resulting in the insertions of 7 and deletions of 7 and 5 glutamines, respectively. These variants do not produce CCD, increased frequency of bone fracture, or BMD alterations. In conclusion, common polymorphisms in Runx2 are associated with FN-BMD. Nevertheless, rare variants that modify the polyglutamine domain of RUNX2 neither have any effect on BMD nor produce the CCD phenotype. These results underscore the significance of polymorphisms in the 5'-region of Runx2 in the determination of FN-BMD.
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Affiliation(s)
- Begoña Pineda
- Research Foundation, Hospital Clínico Universitario, Avenida Blasco Ibáñez 17, Valencia, Spain
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126
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Baniwal SK, Khalid O, Gabet Y, Shah RR, Purcell DJ, Mav D, Kohn-Gabet AE, Shi Y, Coetzee GA, Frenkel B. Runx2 transcriptome of prostate cancer cells: insights into invasiveness and bone metastasis. Mol Cancer 2010; 9:258. [PMID: 20863401 PMCID: PMC2955618 DOI: 10.1186/1476-4598-9-258] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2010] [Accepted: 09/23/2010] [Indexed: 02/07/2023] Open
Abstract
Background Prostate cancer (PCa) cells preferentially metastasize to bone at least in part by acquiring osteomimetic properties. Runx2, an osteoblast master transcription factor, is aberrantly expressed in PCa cells, and promotes their metastatic phenotype. The transcriptional programs regulated by Runx2 have been extensively studied during osteoblastogenesis, where it activates or represses target genes in a context-dependent manner. However, little is known about the gene regulatory networks influenced by Runx2 in PCa cells. We therefore investigated genome wide mRNA expression changes in PCa cells in response to Runx2. Results We engineered a C4-2B PCa sub-line called C4-2B/Rx2dox, in which Doxycycline (Dox) treatment stimulates Runx2 expression from very low to levels observed in other PCa cells. Transcriptome profiling using whole genome expression array followed by in silico analysis indicated that Runx2 upregulated a multitude of genes with prominent cancer associated functions. They included secreted factors (CSF2, SDF-1), proteolytic enzymes (MMP9, CST7), cytoskeleton modulators (SDC2, Twinfilin, SH3PXD2A), intracellular signaling molecules (DUSP1, SPHK1, RASD1) and transcription factors (Sox9, SNAI2, SMAD3) functioning in epithelium to mesenchyme transition (EMT), tissue invasion, as well as homing and attachment to bone. Consistent with the gene expression data, induction of Runx2 in C4-2B cells enhanced their invasiveness. It also promoted cellular quiescence by blocking the G1/S phase transition during cell cycle progression. Furthermore, the cell cycle block was reversed as Runx2 levels declined after Dox withdrawal. Conclusions The effects of Runx2 in C4-2B/Rx2dox cells, as well as similar observations made by employing LNCaP, 22RV1 and PC3 cells, highlight multiple mechanisms by which Runx2 promotes the metastatic phenotype of PCa cells, including tissue invasion, homing to bone and induction of high bone turnover. Runx2 is therefore an attractive target for the development of novel diagnostic, prognostic and therapeutic approaches to PCa management. Targeting Runx2 may prove more effective than focusing on its individual downstream genes and pathways.
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Affiliation(s)
- Sanjeev K Baniwal
- Department of Biochemistry & Molecular Biology, University of Southern California, Los Angeles, CA, USA.
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127
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Cleidocranial dysplasia with severe parietal bone dysplasia: a new (p.Val124Serfs) RUNX2 mutation. Clin Dysmorphol 2010; 19:150-152. [PMID: 20299969 DOI: 10.1097/mcd.0b013e32833593a1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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128
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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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129
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Han MS, Kim HJ, Wee HJ, Lim KE, Park NR, Bae SC, van Wijnen AJ, Stein JL, Lian JB, Stein GS, Choi JY. The cleidocranial dysplasia-related R131G mutation in the Runt-related transcription factor RUNX2 disrupts binding to DNA but not CBF-beta. J Cell Biochem 2010; 110:97-103. [PMID: 20225274 DOI: 10.1002/jcb.22516] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Cleidocranial dysplasia (CCD) is caused by haploinsufficiency in RUNX2 function. We have previously identified a series of RUNX2 mutations in Korean CCD patients, including a novel R131G missense mutation in the Runt-homology domain. Here, we examine the functional consequences of the RUNX2(R131G) mutation, which could potentially affect DNA binding, nuclear localization signal, and/or heterodimerization with core-binding factor-beta (CBF-beta). Immunofluorescence microscopy and western blot analysis with subcellular fractions show that RUNX2(R131G) is localized in the nucleus. Immunoprecipitation analysis reveals that heterodimerization with CBF-beta is retained. However, precipitation assays with biotinylated oligonucleotides and reporter gene assays with RUNX2 responsive promoters together reveal that DNA-binding activity and consequently the transactivation of potential of RUNX2(R131G) is abrogated. We conclude that loss of DNA binding, but not nuclear localization or CBF-beta heterodimerization, causes RUNX2 haploinsufficiency in patients with the RUNX2(R131G) mutation. Retention of specific functions including nuclear localization and binding to CBF-beta of the RUNX2(R131G) mutation may render the mutant protein an effective competitor that interferes with wild-type function.
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Affiliation(s)
- Min-Su Han
- Department of Biochemistry and Cell Biology, School of Medicine, WCU Program, Cell and Matrix Research Institute, Kyungpook National University, Daegu 700-422, South Korea
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130
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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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131
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Alvarez-Saavedra M, Carrasco L, Sura-Trueba S, Demarchi Aiello V, Walz K, Neto JX, Young JI. Elevated expression of MeCP2 in cardiac and skeletal tissues is detrimental for normal development. Hum Mol Genet 2010; 19:2177-90. [PMID: 20203171 DOI: 10.1093/hmg/ddq096] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
MeCP2 plays a critical role in interpreting epigenetic signatures that command chromatin conformation and regulation of gene transcription. In spite of MeCP2's ubiquitous expression, its functions have always been considered in the context of brain physiology. In this study, we demonstrate that alterations of the normal pattern of expression of MeCP2 in cardiac and skeletal tissues are detrimental for normal development. Overexpression of MeCP2 in the mouse heart leads to embryonic lethality with cardiac septum hypertrophy and dysregulated expression of MeCP2 in skeletal tissue produces severe malformations. We further show that MeCP2's expression in the heart is developmentally regulated; further suggesting that it plays a key role in regulating transcriptional programs in non-neural tissues.
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132
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Asher RJ, Bennett N, Lehmann T. The new framework for understanding placental mammal evolution. Bioessays 2010; 31:853-64. [PMID: 19582725 DOI: 10.1002/bies.200900053] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
An unprecedented level of confidence has recently crystallized around a new hypothesis of how living placental mammals share a pattern of common descent. The major groups are afrotheres (e.g., aardvarks, elephants), xenarthrans (e.g., anteaters, sloths), laurasiatheres (e.g., horses, shrews), and euarchontoglires (e.g., humans, rodents). Compared with previous hypotheses this tree is remarkably stable; however, some uncertainty persists about the location of the placental root, and (for example) the position of bats within laurasiatheres, of sea cows and aardvarks within afrotheres, and of dermopterans within euarchontoglires. A variety of names for sub-clades within the new placental mammal tree have been proposed, not all of which follow conventions regarding priority and stability. More importantly, the new phylogenetic framework enables the formulation of new hypotheses and testing thereof, for example regarding the possible developmental dichotomy that seems to distinguish members of the newly identified southern and northern radiations of living placental mammals.
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Affiliation(s)
- Robert J Asher
- Department of Zoology, University of Cambridge, Downing St., Cambridge CB23EJ, UK.
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133
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Liakhovitskaia A, Lana-Elola E, Stamateris E, Rice DP, van 't Hof RJ, Medvinsky A. The essential requirement for Runx1 in the development of the sternum. Dev Biol 2010; 340:539-46. [PMID: 20152828 DOI: 10.1016/j.ydbio.2010.02.005] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2009] [Revised: 02/01/2010] [Accepted: 02/02/2010] [Indexed: 02/03/2023]
Abstract
Runx1 is highly expressed in chondroprogenitor and osteoprogenitor cells and in vitro experiments suggest that Runx1 is important in the early stages of osteoblast and chondrocyte differentiation. However, because Runx1 knockout mice are early embryonic lethal due to failure of hematopoiesis, the role of Runx1 in skeletogenesis remains unclear. We studied the role of Runx1 in skeletal development using a Runx1 reversible knockout mouse model. By crossing with Tie2-Cre deletor mice, Runx1 expression was selectively rescued in the endothelial and hematopoietic systems but not in the skeleton. Although Runx1(Re/Re) embryos survived until birth and had a generally normal skeleton, the development of mineralization in the sternum and some skull elements was significantly disrupted. In contrast to wild-type embryos, the sternum of E17.5 Runx1(Re/Re) embryos showed high levels of Sox-9 and collagen type II expression and lack of development of hypertrophic chondrocytes. In situ hybridization analysis demonstrated that, in contrast to the vertebrae and long bones, the sternum of wild-type embryos expresses high levels of Runx1, but not Runx2, the master regulator of skeletogenesis. Thus, although Runx1 is not essential for major skeletal development, it does play an essential role in the development of the sternum and some skull elements.
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Affiliation(s)
- Anna Liakhovitskaia
- MRC Centre for Regenerative Medicine, Institute for Stem Cell Research, University of Edinburgh, Edinburgh EH9 3JQ, UK
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134
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Acevedo AC, da Fonseca JAC, Grinham J, Doudney K, Gomes RR, de Paula LM, Stanier P. Autosomal-dominant ankyloglossia and tooth number anomalies. J Dent Res 2009; 89:128-32. [PMID: 20042737 DOI: 10.1177/0022034509356401] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Ankyloglossia is a congenital oral anomaly characterized by the presence of a hypertrophic lingual frenulum. It frequently accompanies X-linked cleft palate and is sometimes seen alone due to mutations in the gene encoding the transcription factor TBX22, while knockout of Lgr5 in the mouse results in ankyloglossia. The aim of the present study was to characterize the phenotype and to verify sequence variations in the LGR5 gene in a Brazilian family with ankyloglossia associated with tooth number anomalies. Twelve individuals of three generations were submitted to physical, oral, and radiographic examinations and molecular analysis. Eight had ankyloglossia with various degrees of severity. Six also had hypodontia in the lower incisor region; one had a supernumerary tooth in this region, and another had a supernumerary tooth in the lower premolar region. The characterization of this family determined an autosomal-dominant inheritance and excluded the LGR5 gene mutations as being involved in the pathogenesis of this condition.
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Affiliation(s)
- A C Acevedo
- Oral Care Center for Inherited Diseases, University Hospital of Brasilia, Department of Dentistry, University of Brasilia, Brazil.
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135
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Jonason JH, Xiao G, Zhang M, Xing L, Chen D. Post-translational Regulation of Runx2 in Bone and Cartilage. J Dent Res 2009; 88:693-703. [PMID: 19734454 DOI: 10.1177/0022034509341629] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The Runx2 gene product is essential for mammalian bone development. In humans, Runx2 haploinsufficiency results in cleidocranial dysplasia, a skeletal disorder characterized by bone and dental abnormalities. At the molecular level, Runx2 acts as a transcription factor for genes expressed in hypertrophic chondrocytes and osteoblasts. Runx2 gene expression and protein function are regulated on multiple levels, including transcription, translation, and post-translational modification. Furthermore, Runx2 is involved in numerous protein-protein interactions, most of which either activate or repress transcription of target genes. In this review, we discuss expression of Runx2 during development as well as the post-translational regulation of Runx2 through modification by phosphorylation, ubiquitination, and acetylation.
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Affiliation(s)
- J H Jonason
- Department of Orthopaedics, Center for Musculoskeletal Research, University of Rochester School of Medicine, 601 Elmwood Avenue, Box 665, Rochester, NY 14642, USA
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136
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Zhang C, Zheng S, Wang Y, Zhu J, Zhu X, Zhao Y, Ge L. Novel RUNX2 Mutations in Chinese Individuals with Cleidocranial Dysplasia. J Dent Res 2009; 88:861-6. [PMID: 19767586 DOI: 10.1177/0022034509342083] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Cleidocranial dysplasia (CCD) is an inherited autosomal-dominant skeletal disease caused by heterozygous mutations in the osteoblast-specific transcription factor, RUNX2. We performed mutation analysis of RUNX2 on four unrelated Chinese individuals with CCD. Three novel distinct mutations were detected in the coding region of RUNX2: two missense and one frameshift. These mutations were exclusively clustered within the Runt domain. One missense mutation converts threonine to isoleucine at codon 200 (T200I). The other one substitutes leucine for arginine at codon 225 (R225L), which affects many family members. The frame-shift mutation (214fs) in exon3 leads to the introduction of a translational stop codon at codon 221, resulting in a truncated RUNX2 protein. The reporter gene assays revealed that all the mutants exhibited significantly reduced transactivation activities on the osteocalcin promoter. Our results provide new genetic evidence that mutations involved in RUNX2 contribute to CCD. Abbreviations: AML3, gene encoding acute myeloid leukemia protein 3; bp, base pair; CBFA1, gene encoding core-binding factor 1; CBFβ, gene encoding core-binding factor β; CCD, cleidocranial dysplasia; NLS, nuclear localization signal; OSE2, osteoblast-specific cis-acting element 2; PEBP2A, gene encoding polyoma enhancer binding protein 2A; PST, proline/serine/ threonine-rich domain; Q/A, glutamine-alanine repeat domain; Runt, Runt Homology Domain; RUNX2, the mammalian runt-related genes 2; RUNX2, Runt-related protein 2.
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Affiliation(s)
- C.Y. Zhang
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, 22 Zhongguancun Nandajie, Haidian District, Beijing 100081, China; and
- Research Laboratory of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing, China
| | - S.G. Zheng
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, 22 Zhongguancun Nandajie, Haidian District, Beijing 100081, China; and
- Research Laboratory of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing, China
| | - Y.X. Wang
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, 22 Zhongguancun Nandajie, Haidian District, Beijing 100081, China; and
- Research Laboratory of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing, China
| | - J.X. Zhu
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, 22 Zhongguancun Nandajie, Haidian District, Beijing 100081, China; and
- Research Laboratory of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing, China
| | - X. Zhu
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, 22 Zhongguancun Nandajie, Haidian District, Beijing 100081, China; and
- Research Laboratory of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing, China
| | - Y.M. Zhao
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, 22 Zhongguancun Nandajie, Haidian District, Beijing 100081, China; and
- Research Laboratory of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing, China
| | - L.H. Ge
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, 22 Zhongguancun Nandajie, Haidian District, Beijing 100081, China; and
- Research Laboratory of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing, China
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Abstract
OBJECTIVE Mutations in the RUNX2 gene, a master regulator of bone formation, have been identified in cleidocranial dysplasia (CCD) patients. CCD is a rare autosomal-dominant disease characterized by the delayed closure of cranial sutures, defects in clavicle formation, and supernumerary teeth. The purposes of this study were to identify genetic causes of two CCD nuclear families and to report their clinical phenotypes. MATERIALS AND METHODS We identified two CCD nuclear families and performed mutational analyses to clarify the underlying molecular genetic etiology. RESULTS Mutational analysis revealed a novel nonsense mutation (c.273T>A, p.L93X) in family 1 and a de novo missense one (c.673C>T, p.R225W) in family 2. Individuals with a nonsense mutation showed maxillary hypoplasia, delayed eruption, multiple supernumerary teeth, and normal stature. In contrast, an individual with a de novo missense mutation in the Runt domain showed only one supernumerary tooth and short stature. CONCLUSIONS Mutational and phenotypic analyses showed that the severity of mutations on the skeletal system may not necessarily correlate with that of the disruption of tooth development.
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Affiliation(s)
- H-M Ryoo
- Department of Cell and Developmental Biology, Dental Research Institute and BK21 Program, School of Dentistry, Seoul National University, Seoul 110-768, Korea
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138
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Li Y, Pan W, Xu W, He N, Chen X, Liu H, Darryl Quarles L, Zhou H, Xiao Z. RUNX2 mutations in Chinese patients with cleidocranial dysplasia. Mutagenesis 2009; 24:425-31. [PMID: 19515746 PMCID: PMC2734498 DOI: 10.1093/mutage/gep025] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Cleidocranial dysplasia (CCD) is an autosomal dominant bone disease in humans caused by haploinsufficiency of the RUNX2 gene. The RUNX2 has two major isoforms derived from P1 and P2 promoters. Over 90 mutations of RUNX2 have been reported associated with CCD. In our study, DNA samples of nine individuals from three unrelated CCD families were collected and screened for all exons of RUNX2 and 2 kb of P1 and P2 promoters. We identified two point mutations in the RUNX2 gene in Case 1, including a nonsense mutation (c.577C>T) that has been reported previously and a silent substitution (c.240G>A). In vitro studies demonstrated that c.577C>T mutation led to truncated RUNX2 protein production and diminished stimulating effects on mouse osteocalcin promoter activity when compared with full-length Runx2-II and Runx2-I isoforms. These results confirm that loss of function RUNX2 mutation (c.577C>T) in Case 1 family is responsible for its CCD phenotype.
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Affiliation(s)
- Yalin Li
- Department of Pharmacology, School of Pharmacy, Fudan University, Shanghai 201203, China
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139
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Messaed C, Rouleau G. Molecular mechanisms underlying polyalanine diseases. Neurobiol Dis 2009; 34:397-405. [DOI: 10.1016/j.nbd.2009.02.013] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2008] [Revised: 02/12/2009] [Accepted: 02/16/2009] [Indexed: 10/21/2022] Open
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140
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Cunningham ML, Seto ML, Hing AV, Bull MJ, Hopkin RJ, Leppig KA. Cleidocranial dysplasia with severe parietal bone dysplasia: C-terminal RUNX2 mutations. ACTA ACUST UNITED AC 2009; 76:78-85. [PMID: 16463420 DOI: 10.1002/bdra.20231] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
BACKGROUND Cleidocranial dysplasia (CCD) is an autosomal-dominant skeletal dysplasia syndrome that is characterized by widely patent calvarial sutures, clavicular hypoplasia, supernumerary teeth, and short stature. CCD is caused by mutations in the transcription factor RUNX2, which is known to function as a major regulator of bone differentiation. Despite the characterization of 67 unique mutations in 97 individual cases, and the availability of animal models, no obvious genotype-phenotype correlation has emerged. METHODS We describe 3 new cases that were ascertained on the basis of a severe calvarial phenotype, that were associated with 3 novel mutations in the C-terminal region of RUNX2 distal to the DNA-binding runt domain. In addition, a review of all previously described cases was undertaken in an effort to standardize mutation nomenclature, characterize the position of known mutations relative to the runt domain, and explore the hypothesis that C-terminal mutations that preserve the runt domain may lead to more-severe craniofacial phenotypes. RESULTS Upon mutational analysis of RUNX2, we identified either frameshift or splice-site mutations that affect the C-terminal region of the resultant protein distal to the runt domain. CONCLUSIONS In the context of previously described mutations, these cases suggest that C-terminal mutations that preserve the DNA-binding runt domain while disrupting the SMAD 1,2,3,5 binding domain and the nuclear matrix targeting signal may be responsible for the severe phenotype observed.
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Affiliation(s)
- Michael L Cunningham
- Children's Craniofacial Center, Children's Hospital and Regional Medical Center, Seattle, Washington 98195-6320, USA.
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141
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Higashikawa A, Saito T, Ikeda T, Kamekura S, Kawamura N, Kan A, Oshima Y, Ohba S, Ogata N, Takeshita K, Nakamura K, Chung UI, Kawaguchi H. Identification of the core element responsive to runt-related transcription factor 2 in the promoter of human type x collagen gene. ACTA ACUST UNITED AC 2009; 60:166-78. [DOI: 10.1002/art.24243] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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142
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Pamuk ÖN, Mundlos S, Çakir N. Cleidocranial dysplasia in a mother and her two children. Joint Bone Spine 2008; 75:725-7. [DOI: 10.1016/j.jbspin.2007.10.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2007] [Accepted: 10/23/2007] [Indexed: 11/27/2022]
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143
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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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144
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Xuan D, Li S, Zhang X, Lin L, Wang C, Zhang J. A Novel RUNX2 Mutation in Cleidocranial Dysplasia Patients. Biochem Genet 2008; 46:702-7. [PMID: 18777095 DOI: 10.1007/s10528-008-9184-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2007] [Accepted: 05/19/2008] [Indexed: 10/21/2022]
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145
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Lee MTM, Tsai ACH, Chou CH, Sun FM, Huang LC, Yen P, Lin CC, Liu CY, Wu JY, Chen YT, Tsai FJ. Intragenic microdeletion of RUNX2 is a novel mechanism for cleidocranial dysplasia. Genomic Med 2008; 2:45-9. [PMID: 18696259 DOI: 10.1007/s11568-008-9024-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2008] [Revised: 07/16/2008] [Accepted: 07/22/2008] [Indexed: 01/06/2023] Open
Abstract
Cleidocranial dysplasia (CCD; MIM 119600) is a rare autosomal dominant disorder characterized by facial, dental, and skeletal malformations. To date, rearrangement and mutations involving RUNX2, which encodes a transcription factor required for osteoblast differentiation on 6p21, has been the only known molecular etiology for CCD. However, only 70% patients were found to have point mutations, 13% large/contiguous deletion but the rest of 17% remains unknown. We ascertained a family consisted of eight affected individuals with CCD phenotypes. Direct sequencing analysis revealed no mutations in the RUNX2. Real time quantitative PCR were performed which revealed an exon 2 to exon 6 intragenic deletion in RUNX2. Our patients not only demonstrated a unique gene change as a novel mechanism for CCD, but also highlight the importance of considering "deletion" and "duplication" in suspected familial cases before extensive effort of gene hunting be carried.
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146
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Abstract
Comparative morphological and developmental studies, including a recent comparative study of tooth development among the Afrotherian mammals, are indicating the types of genetic mechanisms responsible for the evolution of morphological differences among major mammalian groups.
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Affiliation(s)
- Rodney L Honeycutt
- Natural Science Division, Pepperdine University, Malibu, California 90263-4321, USA.
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147
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Asher RJ, Lehmann T. Dental eruption in afrotherian mammals. BMC Biol 2008; 6:14. [PMID: 18366669 PMCID: PMC2292681 DOI: 10.1186/1741-7007-6-14] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2008] [Accepted: 03/18/2008] [Indexed: 11/29/2022] Open
Abstract
Background Afrotheria comprises a newly recognized clade of mammals with strong molecular evidence for its monophyly. In contrast, morphological data uniting its diverse constituents, including elephants, sea cows, hyraxes, aardvarks, sengis, tenrecs and golden moles, have been difficult to identify. Here, we suggest relatively late eruption of the permanent dentition as a shared characteristic of afrotherian mammals. This characteristic and other features (such as vertebral anomalies and testicondy) recall the phenotype of a human genetic pathology (cleidocranial dysplasia), correlations with which have not been explored previously in the context of character evolution within the recently established phylogeny of living mammalian clades. Results Although data on the absolute timing of eruption in sengis, golden moles and tenrecs are still unknown, craniometric comparisons for ontogenetic series of these taxa show that considerable skull growth takes place prior to the complete eruption of the permanent cheek teeth. Specimens showing less than half (sengis, golden moles) or two-thirds (tenrecs, hyraxes) of their permanent cheek teeth reach or exceed the median jaw length of conspecifics with a complete dentition. With few exceptions, afrotherians are closer to median adult jaw length with fewer erupted, permanent cheek teeth than comparable stages of non-afrotherians. Manatees (but not dugongs), elephants and hyraxes with known age data show eruption of permanent teeth late in ontogeny relative to other mammals. While the occurrence of delayed eruption, vertebral anomalies and other potential afrotherian synapomorphies resemble some symptoms of a human genetic pathology, these characteristics do not appear to covary significantly among mammalian clades. Conclusion Morphological characteristics shared by such physically disparate animals such as elephants and golden moles are not easy to recognize, but are now known to include late eruption of permanent teeth, in addition to vertebral anomalies, testicondy and other features. Awareness of their possible genetic correlates promises insight into the developmental basis of shared morphological features of afrotherians and other vertebrates.
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Affiliation(s)
- Robert J Asher
- Department of Zoology, University of Cambridge, Downing St,, Cambridge CB2 3EJ, UK
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148
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Sears KE, Goswami A, Flynn JJ, Niswander LA. The correlated evolution of Runx2 tandem repeats, transcriptional activity, and facial length in carnivora. Evol Dev 2008; 9:555-65. [PMID: 17976052 DOI: 10.1111/j.1525-142x.2007.00196.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
To assess the ability of protein-coding mutations to contribute to subtle, inter-specific morphologic evolution, here, we test the hypothesis that mutations within the protein-coding region of runt-related transcription factor 2 (Runx2) have played a role in facial evolution in 30 species from a naturally evolving group, the mammalian order Carnivora. Consistent with this hypothesis, we find significant correlations between changes in Runx2 glutamine-alanine tandem-repeat ratio, and both Runx2 transcriptional activity and carnivoran facial length. Furthermore, we identify a potential evolutionary mechanism for the correlation between Runx2 tandem repeat ratio and facial length. Specifically, our results are consistent with the Runx2 tandem repeat system providing a flexible genetic mechanism to rapidly change the timing of ossification. These heterochronic changes, in turn, potentially act on existing allometric variation in carnivoran facial length to generate the disparity in adult facial lengths observed among carnivoran species. Our results suggest that despite potentially great pleiotropic effects, changes to the protein-coding regions of genes such as Runx2 do occur and have the potential to affect subtle morphologic evolution across a diverse array of species in naturally evolving lineages.
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Affiliation(s)
- K E Sears
- Pediatrics Department, Howard Hughes Medical Institute, University of Colorado at Denver and Health Sciences Center, 12800 East, 19th Avenue, Aurora, CO 80045, USA.
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149
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Javed A, Bae JS, Afzal F, Gutierrez S, Pratap J, Zaidi SK, Lou Y, van Wijnen AJ, Stein JL, Stein GS, Lian JB. Structural coupling of Smad and Runx2 for execution of the BMP2 osteogenic signal. J Biol Chem 2008; 283:8412-22. [PMID: 18204048 DOI: 10.1074/jbc.m705578200] [Citation(s) in RCA: 174] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Two regulatory pathways, bone morphogenetic protein (BMP)/transforming growth factor-beta (TGFbeta) and the transcription factor RUNX2, are required for bone formation in vivo. Here we show the interdependent requirement of these pathways to induce an osteogenic program. A panel of Runx2 deletion and point mutants was used to examine RUNX2-SMAD protein-protein interaction and the biological consequences on BMP2-induced osteogenic signaling determined in Runx2 null cells. These cells do not respond to BMP2 signal in the absence of Runx2. We established that a triple mutation in the C-terminal domain of RUNX2, HTY (426-428), disrupts the RUNX2-SMAD interaction, is deficient in its ability to integrate the BMP2/TGFbeta signal on promoter reporter assays, and is only marginally functional in promoting early stages of osteoblast differentiation. Furthermore, the HTY mutation overlaps the unique nuclear matrix targeting signal of Runx factors and exhibits reduced subnuclear targeting. Thus, formation of a RUNX2-SMAD osteogenic complex and subnuclear targeting are structurally and functionally inseparable. Our results establish the critical residues of RUNX2 for execution and completion of BMP2 signaling for osteoblastogenesis through a mechanism that requires RUNX2-SMAD transcriptional activity.
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Affiliation(s)
- Amjad Javed
- Department of Cell Biology and Cancer Center, University of Massachusetts Medical School, Worcester, MA 01655, USA
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150
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Suda N, Hamada T, Hattori M, Torii C, Kosaki K, Moriyama K. Diversity of supernumerary tooth formation in siblings with cleidocranial dysplasia having identical mutation in RUNX2 : possible involvement of non-genetic or epigenetic regulation. Orthod Craniofac Res 2008; 10:222-5. [PMID: 17973689 DOI: 10.1111/j.1601-6343.2007.00404.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
INTRODUCTION Cleidocranial dysplasia (CCD, MIM #119600) is an autosomal-dominant disorder characterized by hypoplasia or aplasia of clavicles, patent fontanelles and short stature. The responsible gene has been identified as RUNX2. CCD is also accompanied by characteristic dental abnormalities, e.g. supernumerary teeth, delayed eruption and impaction of permanent teeth. Intrafamilial variations of skeletal abnormalities are reported but those of dental abnormalities are obscure. To clarify this point, a precise examination of the dental features of CCD siblings having identical mutation was performed. DESIGN Gene mutational analysis of three Japanese CCD siblings and their father was performed. Skeletal and dental characteristics were examined by the inquiry and radiographs. RESULTS Three siblings uniformly showed patent fontanelles and short stature. They and their father had a novel missense mutation in the RUNT-domain (P210S) of RUNX2. The siblings were completely discordant for the dental characteristics with the position and number of supernumerary teeth being completely different. The youngest, a 12-year-old boy, had six supernumerary teeth, which appeared symmetrically around the maxillary canines and mandibular premolars. The second, a 15-year-old girl, had four supernumerary teeth which appeared around the mandibular incisors. The oldest, a 17-year-old boy, had 11 supernumerary teeth, which were symmetrically around the mandibular lateral dentition and asymmetrically around the maxillary incisors and premolars. CONCLUSION The present study suggests the involvement of non-genetic or epigenetic regulation in supernumerary tooth formation in CCD.
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Affiliation(s)
- N Suda
- Department of Maxillofacial Reconstruction and Function, Division of Maxillofacial/Neck Reconstruction, Graduate School, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo, Japan.
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