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Nottmeier C, Liao N, Simon A, Decker MG, Luther J, Schweizer M, Yorgan T, Kaucka M, Bockamp E, Kahl-Nieke B, Amling M, Schinke T, Petersen J, Koehne T. Wnt1 Promotes Cementum and Alveolar Bone Growth in a Time-Dependent Manner. J Dent Res 2021; 100:1501-1509. [PMID: 34009051 PMCID: PMC8649456 DOI: 10.1177/00220345211012386] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The WNT/β-catenin signaling pathway plays a central role in the biology
of the periodontium, yet the function of specific extracellular WNT
ligands remains poorly understood. By using a
Wnt1-inducible transgenic mouse model targeting
Col1a1-expressing alveolar osteoblasts,
odontoblasts, and cementoblasts, we demonstrate that the WNT ligand
WNT1 is a strong promoter of cementum and alveolar bone formation in
vivo. We induced Wnt1 expression for 1, 3, or 9 wk in
Wnt1Tg mice and analyzed them at the age of 6 wk and 12 wk.
Micro–computed tomography (CT) analyses of the mandibles revealed a
1.8-fold increased bone volume after 1 and 3 wk of
Wnt1 expression and a 3-fold increased bone
volume after 9 wk of Wnt1 expression compared to
controls. In addition, the alveolar ridges were higher in Wnt1Tg mice
as compared to controls. Nondecalcified histology demonstrated
increased acellular cementum thickness and cellular cementum volume
after 3 and 9 wk of Wnt1 expression. However, 9 wk of
Wnt1 expression was also associated with
periodontal breakdown and ectopic mineralization of the pulp. The
composition of this ectopic matrix was comparable to those of cellular
cementum as demonstrated by quantitative backscattered electron
imaging and immunohistochemistry for noncollagenous proteins. Our
analyses of 52-wk-old mice after 9 wk of Wnt1
expression revealed that Wnt1 expression affects
mandibular bone and growing incisors but not molar teeth, indicating
that Wnt1 influences only growing tissues. To further
investigate the effect of Wnt1 on cementoblasts, we
stably transfected the cementoblast cell line (OCCM-30) with a vector
expressing Wnt1-HA and performed proliferation as
well as differentiation experiments. These experiments demonstrated
that Wnt1 promotes proliferation but not
differentiation of cementoblasts. Taken together, our findings
identify, for the first time, Wnt1 as a critical
regulator of alveolar bone and cementum formation, as well as provide
important insights for harnessing the WNT signal pathway in
regenerative dentistry.
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Affiliation(s)
- C Nottmeier
- Department of Orthodontics, University Medical Center Hamburg, Hamburg, Germany.,Department of Orthodontics, University of Leipzig Medical Center, Leipzig, Germany
| | - N Liao
- Department of Orthodontics, University Medical Center Hamburg, Hamburg, Germany.,Department of Orthodontics, College of Stomatology, North China University of Science and Technology, Tangshan, China
| | - A Simon
- Department of Orthodontics, University Medical Center Hamburg, Hamburg, Germany
| | - M G Decker
- Department of Orthodontics, University Medical Center Hamburg, Hamburg, Germany
| | - J Luther
- Department of Osteology and Biomechanics, University Medical Center Hamburg, Hamburg, Germany
| | - M Schweizer
- ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - T Yorgan
- Department of Osteology and Biomechanics, University Medical Center Hamburg, Hamburg, Germany
| | - M Kaucka
- Max Planck Institute for Evolutionary Biology, Plön, Germany
| | - E Bockamp
- Institute for Translational Immunology and Research Center for Immunotherapy, University Medical Center, Johannes Gutenberg University, Mainz, Germany
| | - B Kahl-Nieke
- Department of Orthodontics, University Medical Center Hamburg, Hamburg, Germany
| | - M Amling
- Department of Osteology and Biomechanics, University Medical Center Hamburg, Hamburg, Germany
| | - T Schinke
- Department of Osteology and Biomechanics, University Medical Center Hamburg, Hamburg, Germany
| | - J Petersen
- Department of Orthodontics, University of Leipzig Medical Center, Leipzig, Germany.,Department of Osteology and Biomechanics, University Medical Center Hamburg, Hamburg, Germany
| | - T Koehne
- Department of Orthodontics, University Medical Center Hamburg, Hamburg, Germany.,Department of Orthodontics, University of Leipzig Medical Center, Leipzig, Germany
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Prawitt D, Brixel L, Spangenberg C, Eshkind L, Heck R, Oesch F, Zabel B, Bockamp E. RNAi knock-down mice: an emerging technology for post-genomic functional genetics. Cytogenet Genome Res 2004; 105:412-21. [PMID: 15237229 DOI: 10.1159/000078214] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2003] [Accepted: 11/20/2003] [Indexed: 11/19/2022] Open
Abstract
RNA interference (RNAi) has been extensively used for sequence-specific silencing of gene function in mammalian cells. The latest major breakthrough in the application of RNAi technology came from experiments demonstrating RNAi-mediated gene repression in mice and rats. After more than two decades of functional mouse research aimed at developing and continuously improving transgenic and knock-out technology, the advent of RNAi knock-down mice represents a valuable new alternative for studying gene function in vivo. In this review we provide some basic insight as to how RNAi can induce gene silencing to then focus on recent findings concerning the applicability of RNAi for regulating gene function in the mouse. Reviewed topics will include delivery methods for RNAi-mediating molecules, a comparison between traditional knock-out and innovative transgenic RNAi technology and the generation of graded RNAi knock-down phenotypes. Apart from the exciting possibilities RNAi provides for studying gene function in mice, we discuss several caveats and limitations to be considered. Finally, we present prospective strategies as to how RNAi technology might be applied for generating conditional and tissue-restricted knock-down mice.
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Affiliation(s)
- D Prawitt
- Children's Hospital, Johannes Gutenberg-Universität Mainz, Mainz, Germany.
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Sinclair AM, Göttgens B, Barton LM, Stanley ML, Pardanaud L, Klaine M, Gering M, Bahn S, Sanchez M, Bench AJ, Fordham JL, Bockamp E, Green AR. Distinct 5' SCL enhancers direct transcription to developing brain, spinal cord, and endothelium: neural expression is mediated by GATA factor binding sites. Dev Biol 1999; 209:128-42. [PMID: 10208748 DOI: 10.1006/dbio.1999.9236] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The SCL gene encodes a basic helix-loop-helix transcription factor with a pivotal role in the development of endothelium and of all hematopoietic lineages. SCL is also expressed in the central nervous system, although its expression pattern has not been examined in detail and its function in neural development is unknown. In this article we present the first analysis of SCL transcriptional regulation in vivo. We have identified three spatially distinct regulatory modules, each of which was both necessary and sufficient to direct reporter gene expression in vivo to three different regions within the normal SCL expression domain, namely, developing endothelium, midbrain, and hindbrain/spinal cord. In addition we have demonstrated that GATA factor binding sites are essential for neural expression of the SCL constructs. The midbrain element was particularly powerful and axonal lacZ expression revealed the details of axonal projections, thus implicating SCL in the development of occulomotor, pupillary, or retinotectal pathways. The neural expression pattern of the SCL gene was highly conserved in mouse, chicken, and zebrafish embryos and the 5' region of the chicken SCL locus exhibited a striking degree of functional conservation in transgenic mice. These data suggest that SCL performs critical functions in neural development. The regulatory elements identified here provide important tools for analyzing these functions.
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Affiliation(s)
- A M Sinclair
- Department of Haematology, University of Cambridge, MRC Centre, Hills Road, Cambridge, CB2 2QH, United Kingdom
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