101
|
Insights from human genetic studies into the pathways involved in osteoarthritis. Nat Rev Rheumatol 2013; 9:573-83. [DOI: 10.1038/nrrheum.2013.121] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
102
|
Cheng S, Xing W, Zhou X, Mohan S. Haploinsufficiency of osterix in chondrocytes impairs skeletal growth in mice. Physiol Genomics 2013; 45:917-23. [PMID: 23943855 DOI: 10.1152/physiolgenomics.00111.2013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Osterix (Osx) is essential for both intramembranous or endochondral bone formation. Osteoblast-specific ablation of Osx using Col1α1-Cre resulted in osteopenia, because of impaired osteoblast differentiation in adult mice. Since Osx is also known to be expressed in chondrocytes, we evaluated the role of Osx expressed in chondrocytes by examining the skeletal phenotype of mice with conditional disruption of Osx in Col2α1-expressing chondrocytes. Surprisingly, Cre-positive mice that were homozygous for Osx floxed alleles died after birth. Alcian blue and alizarin red staining revealed that the lengths of skeleton, femur, and vertebrae were reduced by 21, 26, and 14% (P < 0.01), respectively, in the knockout (KO) compared with wild-type mice. To determine if haploid insufficiency of Osx in chondrocytes influenced postnatal skeletal growth, we compared skeletal phenotype of floxed heterozygous mice that were Cre-positive or Cre-negative. Body length was reduced by 8% (P < 0.001), and areal BMD of total body, femur, and tibia was reduced by 5, 7, and 8% (P < 0.05), respectively, in mice with conditional disruption of one allele of Osx in chondrocytes. Micro-CT showed reduced cortical volumetric bone mineral density and trabecular bone volume to total volume in the femurs of Osx(flox/+);col2α1-Cre mice. Histological analysis revealed that the impairment of longitudinal growth was associated with disrupted growth plates in the Osx(flox/+);col2α1-Cre mice. Primary chondrocytes isolated from KO embryos showed reduced expression of chondral ossification markers but elevated expression of chondrogenesis markers. Our findings indicate that Osx expressed in chondrocytes regulates bone growth in part by regulating chondrocyte hypertrophy.
Collapse
Affiliation(s)
- Shaohong Cheng
- Musculoskeletal Disease Center, Jerry L. Pettis VA Medical Center, Loma Linda, California
| | | | | | | |
Collapse
|
103
|
Kim YI, Lee S, Jung SH, Kim HT, Choi JH, Lee MS, You KH, Yeo SY, Yoo KW, Kwak S, Lee JN, Park R, Choe SK, Kim CH. Establishment of a bone-specific col10a1:GFP transgenic zebrafish. Mol Cells 2013; 36:145-50. [PMID: 23852131 PMCID: PMC3887955 DOI: 10.1007/s10059-013-0117-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Revised: 06/05/2013] [Accepted: 06/10/2013] [Indexed: 01/21/2023] Open
Abstract
During skeletal development, both osteogenic and chondrogenic programs are initiated from multipotent mesenchymal cells, requiring a number of signaling molecules, transcription factors, and downstream effectors to orchestrate the sophisticated process. Col10a1, an important downstream effector gene, has been identified as a marker for maturing chondrocytes in higher vertebrates, such as mammals and birds. In zebrafish, this gene has been shown to be expressed in both osteoblasts and chondrocytes, but no study has reported its role in osteoblast development. To initially delineate the osteogenic program from chondrogenic lineage development, we used the zebrafish col10a1 promoter to establish a transgenic zebrafish expressing a GFP reporter specifically in osteoblast-specific bone structures that do not involve cartilaginous programs. A construct harboring a -2.2-kb promoter region was found to be sufficient to drive the reporter gene in osteoblast-specific bone structures within the endogenous col10a1 expression domain, confirming that separable cis-acting elements exist for distinct cell type-specific expression of col10a1 during zebrafish skeletal development. The -2.2-kb col10a1:GFP transgenic zebrafish marking only bone structures derived from osteoblasts will undoubtedly be an invaluable tool for identifying and characterizing molecular events driving osteoblast development in zebrafish, which may further provide a differential mechanism where col10a1 is involved in the development of chondrocytes undergoing maturation in other vertebrate systems.
Collapse
Affiliation(s)
- Yong-Il Kim
- Department of Biology, Chungnam National University, Daejeon 305-764,
Korea
- Center for Metabolic Function Regulation, Department of Microbiology, College of Medicine, Wonkwang University, Iksan 570-749,
Korea
| | - Suman Lee
- Department of Biomedical Science, CHA University, Seongnam 463-836,
Korea
| | - Seung-Hyun Jung
- Department of Biology, Chungnam National University, Daejeon 305-764,
Korea
| | - Hyun-Taek Kim
- Department of Biology, Chungnam National University, Daejeon 305-764,
Korea
| | - Jung-Hwa Choi
- Department of Biology, Chungnam National University, Daejeon 305-764,
Korea
| | - Mi-Sun Lee
- Department of Biology, Chungnam National University, Daejeon 305-764,
Korea
| | - Kwan-Hee You
- Department of Biology, Chungnam National University, Daejeon 305-764,
Korea
| | - Sang-Yeob Yeo
- Department of Biotechnology, Division of Applied Chemistry and Biotechnology, Hanbat National University, Daejeon 305-719,
Korea
| | - Kyeong-Won Yoo
- Center for Metabolic Function Regulation, Department of Microbiology, College of Medicine, Wonkwang University, Iksan 570-749,
Korea
| | - SeongAe Kwak
- Center for Metabolic Function Regulation, Department of Microbiology, College of Medicine, Wonkwang University, Iksan 570-749,
Korea
| | - Joon No Lee
- Center for Metabolic Function Regulation, Department of Microbiology, College of Medicine, Wonkwang University, Iksan 570-749,
Korea
| | - Raekil Park
- Center for Metabolic Function Regulation, Department of Microbiology, College of Medicine, Wonkwang University, Iksan 570-749,
Korea
| | - Seong-Kyu Choe
- Center for Metabolic Function Regulation, Department of Microbiology, College of Medicine, Wonkwang University, Iksan 570-749,
Korea
| | - Cheol-Hee Kim
- Department of Biology, Chungnam National University, Daejeon 305-764,
Korea
| |
Collapse
|
104
|
Zhang Q, Zhou J, Ge H, Cheng B. Tgif1 and SnoN modified chondrocytes or stem cells for tendon-bone insertion regeneration. Med Hypotheses 2013; 81:163-6. [PMID: 23747175 DOI: 10.1016/j.mehy.2013.05.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Revised: 05/02/2013] [Accepted: 05/15/2013] [Indexed: 10/26/2022]
Abstract
Tendon-bone insertion injuries are a common occurrence but rarely heal, despite the many strategies that have been employed. The tendon-bone insertion consists of four types of tissues: tendon, fibrocartilage, mineral fibrocartilage and bone, making it hard to regenerate. The key to reconstructing the tendon enthesis is to rebuild the gradations of cell type, collagen type, mineral content and collagen fiber orientation. Chondrocytes were found to be able to differentiate into tendon and bone tissues upon special stimulation, which offers promise for tendon enthesis regeneration. Tgif1 is a key factor that represses the expression of the cartilage master gene Sox9, which is induced by TGFβs, and changes the expression rate of Sox9 versus Scx, eventually promoting fibrogenesis. SnoN is a key factor that is induced by TGFβs to inhibit the hypertrophy of chondrocytes and therefore bone formation. It appears that the induction of Tgif1 and the repression of SnoN can cause chondrocytes to differentiate into tendon and bone tissues. Moreover, a gradation of the expression levels of Tgif1 and SnoN in chondrocytes may create a gradation of the tissue from tendon to fibrocartilage to bone. Consequently, we propose that a gradation of gene-modified chondrocytes (Tgif1-inducing cells, primary cells, SnoN-repressing cells) or stem cells that arise from a gradation of stimulation (Tgif1 induction and SnoN repression) will aid in the regeneration of the tendon-bone insertion.
Collapse
Affiliation(s)
- Qiang Zhang
- Department of Orthopedics, Shanghai Tenth People's Hospital, Tongji University School of Medcine, Shanghai, China
| | | | | | | |
Collapse
|
105
|
Itoh H, Hara Y, Tagawa M, Kato T, Ochi H, Koga D, Okawa A, Asou Y. Evaluation of the association between runt-related transcription factor 2 expression and intervertebral disk aging in dogs. Am J Vet Res 2013; 73:1553-9. [PMID: 23013180 DOI: 10.2460/ajvr.73.10.1553] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To investigate the relationship between runt-related transcription factor 2 (RUNX2) expression in canine nucleus pulposus (NP) cells and intervertebral disk aging in chondrodystrophoid dogs. ANIMALS 7 healthy Beagles (mean age, 35.6 months) and 11 Dachshunds with herniated disks (mean age, 61 months). PROCEDURES All dogs underwent MRI examination of the thoracic and lumbar vertebral column immediately before sample collection under general anesthesia. The disk center-to-CSF T2-weighted signal intensity ratio was determined for healthy Beagles. Samples of NP were obtained from nonherniated disks in healthy Beagles and from herniated disks during surgical treatment of hospitalized Dachshunds. Samples were evaluated for RUNX2 and matrix metalloproteinase 13 transcript expression via reverse transcriptase PCR assay; RUNX2 protein expression was evaluated via immunohistochemical analysis, and correlation between these variables and age of dogs was evaluated. A 3' and 5' rapid amplification of cDNA ends method was used to identify the RUNX2 coding region. RESULTS RUNX2 cDNA had > 97% conservation with the human cDNA sequence and approximately 95% conservation with the mouse cDNA sequence; RUNX2 and matrix metalloproteinase 13 mRNA expression and RUNX2 protein expression in NP cells were positively correlated with age. The disk center-to-CSF T2-weighted signal intensity ratio was negatively correlated with RUNX2 protein expression in the NP of healthy dogs. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that RUNX2 mRNA and protein expression in the NP are enhanced in aging intervertebral disks in dogs.
Collapse
Affiliation(s)
- Hisanori Itoh
- Division of Veterinary Surgery, Department of Veterinary Science, Faculty of Veterinary Medicine, Nippon Veterinary and Life Science University, 1-7-1 Kyonan-cho, Musashino, Tokyo, Japan
| | | | | | | | | | | | | | | |
Collapse
|
106
|
Differentiation of mesenchymal stem cells to osteoblasts and chondrocytes: a focus on adenosine receptors. Expert Rev Mol Med 2013; 15:e1. [PMID: 23406574 DOI: 10.1017/erm.2013.2] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Skeletogenesis, either during development, post-injury or for maintenance, is a carefully coordinated process reliant on the appropriate differentiation of mesenchymal stem cells. Some well described, as well as a new regulator of this process (adenosine receptors), are alike in that they signal via cyclic-AMP (cAMP). This review highlights the known contribution of cAMP signalling to mesenchymal stem cell differentiation to osteoblasts and to chondrocytes. Focus has been given to how these regulators influence the commitment of the osteochondroprogenitor to these separate lineages.
Collapse
|
107
|
Effect of parathyroid hormone-related protein in an in vitro hypertrophy model for mesenchymal stem cell chondrogenesis. INTERNATIONAL ORTHOPAEDICS 2013; 37:945-51. [PMID: 23371427 DOI: 10.1007/s00264-013-1800-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2012] [Accepted: 01/15/2013] [Indexed: 10/27/2022]
Abstract
PURPOSE Mesenchymal stem cells (MSCs) express markers of hypertrophic chondrocytes during chondrogenic differentiation. We tested the suitability of parathyroid hormone-related protein (PTHrP), a regulator of chondrocyte hypertrophy in embryonic cartilage development, for the suppression of hypertrophy in an in vitro hypertrophy model of chondrifying MSCs. METHODS Chondrogenesis was induced in human MSCs in pellet culture for two weeks and for an additional two weeks cultures were either maintained in standard chondrogenic medium or transferred to a hypertrophy-enhancing medium. PTHrP(1-40) was added to the medium throughout the culture period at concentrations from 1 to 1,000 pM. Pellets were harvested on days one, 14 and 28 for biochemical and histological analysis. RESULTS Hypertrophic medium clearly enhanced the hypertrophic phenotype, with increased cell size, and strong alkaline phosphatase (ALP) and type X collagen staining. In chondrogenic medium, 1-100 pM PTHrP(1-40) did not inhibit chondrogenic differentiation, whereas 1,000 pM PTHrP(1-40) significantly reduced chondrogenesis. ALP activity was dose-dependently reduced by PTHrP(1-40) at 10-1,000 pM in chondrogenic conditions. Under hypertrophy-enhancing conditions, PTHrP(1-40) did not inhibit the induction of the hypertrophy. At the highest concentration (1,000 pM) in the hypertrophic group, aggregates were partially dedifferentiated and differentiated areas of these aggregates maintained their hypertrophic appearance. CONCLUSIONS PTHrP(1-40) treatment dose-dependently reduced ALP expression in MSC pellets cultured under standard chondrogenic conditions and is thus beneficial for the maintenance of the chondrogenic phenotype in this medium condition. When cultured under hypertrophy-enhancing conditions, PTHrP(1-40) could not diminish the induced enhancement of hypertrophy in the MSC pellets.
Collapse
|
108
|
Yu S, Geng Q, Sun F, Yu Y, Pan Q, Hong A. Osteogenic differentiation of C2C12 myogenic progenitor cells requires the Fos-related antigen Fra-1 – A novel target of Runx2. Biochem Biophys Res Commun 2013; 430:173-8. [DOI: 10.1016/j.bbrc.2012.11.033] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2012] [Accepted: 11/08/2012] [Indexed: 02/03/2023]
|
109
|
Dalle Carbonare L, Innamorati G, Valenti MT. Transcription factor Runx2 and its application to bone tissue engineering. Stem Cell Rev Rep 2012; 8:891-7. [PMID: 22139789 DOI: 10.1007/s12015-011-9337-4] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Cbfa1/Runx2 is a bone transcription factor homologous to the Drosophila protein, Runt. Runx2 is a master gene that encodes for a protein involved in the osteogenic differentiation process from mesenchymal precursors. It is known that in Cbfa1 deficient mice (Cbfa1(-/-)) the lack of mature osteoblasts is associated to incomplete bone mineralization. An important aim of modern biology is the development of new molecular tools for identification of therapeutic approaches. Recent discoveries in cell and molecular biology enabled researchers in the bone tissue-engineering field to develop new strategies for gene and cell-based therapies. This review summarizes the process of osteogenic differentiation from mesenchymal stem cells and the importance of bone regeneration is discussed. In particular, given the increasing interest in the study of the transcription factor Runx2, this review highlights the role of this target gene and addresses recent strategies using Runx2 for bone regeneration.
Collapse
Affiliation(s)
- Luca Dalle Carbonare
- Department of Medicine, Clinic of Internal Medicine, section D, University of Verona, Piazzale Scuro, 10, 37134 Verona, Italy
| | | | | |
Collapse
|
110
|
Venkatesan JK, Ekici M, Madry H, Schmitt G, Kohn D, Cucchiarini M. SOX9 gene transfer via safe, stable, replication-defective recombinant adeno-associated virus vectors as a novel, powerful tool to enhance the chondrogenic potential of human mesenchymal stem cells. Stem Cell Res Ther 2012; 3:22. [PMID: 22742415 PMCID: PMC3583131 DOI: 10.1186/scrt113] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Accepted: 06/28/2012] [Indexed: 01/21/2023] Open
Abstract
Introduction Transplantation of genetically modified human bone marrow-derived mesenchymal stem cells (hMSCs) with an accurate potential for chondrogenic differentiation may be a powerful means to enhance the healing of articular cartilage lesions in patients. Here, we evaluated the benefits of delivering SOX9 (a key regulator of chondrocyte differentiation and cartilage formation) via safe, maintained, replication-defective recombinant adeno-associated virus (rAAV) vector on the capability of hMSCs to commit to an adequate chondrocyte phenotype compared with other mesenchymal lineages. Methods The rAAV-FLAG-hSOX9 vector was provided to both undifferentiated and lineage-induced MSCs freshly isolated from patients to determine the effects of the candidate construct on the viability, biosynthetic activities, and ability of the cells to enter chondrogenic, osteogenic, and adipogenic differentiation programs compared with control treatments (rAAV-lacZ or absence of vector administration). Results Marked, prolonged expression of the transcription factor was noted in undifferentiated and chondrogenically differentiated cells transduced with rAAV-FLAG-hSOX9, leading to increased synthesis of major extracellular matrix components compared with control treatments, but without effect on proliferative activities. Chondrogenic differentiation (SOX9, type II collagen, proteoglycan expression) was successfully achieved in all types of cells but strongly enhanced when the SOX9 vector was provided. Remarkably, rAAV-FLAG-hSOX9 delivery reduced the levels of markers of hypertrophy, terminal and osteogenic/adipogenic differentiation in hMSCs (type I and type X collagen, alkaline phosphatise (ALP), matrix metalloproteinase 13 (MMP13), and osteopontin (OP) with diminished expression of the osteoblast-related transcription factor runt-related transcription factor 2 (RUNX2); lipoprotein lipase (LPL), peroxisome proliferator-activated receptor gamma 2 (PPARG2)), as well as their ability to undergo proper osteo-/adipogenic differentiation. These effects were accompanied with decreased levels of β-catenin (a mediator of the Wnt signaling pathway for osteoblast lineage differentiation) and enhanced parathyroid hormone-related protein (PTHrP) expression (an inhibitor of hypertrophic maturation, calcification, and bone formation) via SOX9 treatment. Conclusions This study shows the potential benefits of rAAV-mediated SOX9 gene transfer to propagate hMSCs with an advantageous chondrocyte differentiation potential for future, indirect therapeutic approaches that aim at restoring articular cartilage defects in the human population.
Collapse
Affiliation(s)
- Jagadeesh K Venkatesan
- Center of Experimental Orthopaedics, Saarland University Medical CenterHomburg/Saar, Germany
| | | | | | | | | | | |
Collapse
|
111
|
Goodnough LH, Chang AT, Treloar C, Yang J, Scacheri PC, Atit RP. Twist1 mediates repression of chondrogenesis by β-catenin to promote cranial bone progenitor specification. Development 2012; 139:4428-38. [PMID: 23095887 DOI: 10.1242/dev.081679] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The bones of the mammalian skull vault form through intramembranous ossification. Skull bones ossify directly, in a process regulated by β-catenin, instead of passing through a cartilage intermediate. We tested whether β-catenin is necessary for fate selection of intramembranous bone progenitors in the skull. Here, we show in mice that removal of β-catenin from skull bone progenitors results in the near complete transformation of the skull bones to cartilage, whereas constitutive β-catenin activation inhibits skull bone fate selection. β-catenin directly activated Twist1 expression in skull progenitors, conditional Twist1 deletion partially phenocopied the absence of β-catenin, and Twist1 deletion partially restored bone formation in the presence of constitutive β-catenin activation. Finally, Twist1 bound robustly to the 3'UTR of Sox9, the central initiator of chondrogenesis, suggesting that Twist1 might directly repress cartilage formation through Sox9. These findings provide insight into how β-catenin signaling via Twist1 actively suppresses the formation of cartilage and promotes intramembranous ossification in the skull.
Collapse
Affiliation(s)
- L Henry Goodnough
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | | | | | | | | | | |
Collapse
|
112
|
Sun H, Yang F, Chu W, Zhao H, McMahon C, Li C. Lentiviral-mediated RNAi knockdown of Cbfa1 gene inhibits endochondral ossification of antler stem cells in micromass culture. PLoS One 2012; 7:e47367. [PMID: 23056636 PMCID: PMC3467256 DOI: 10.1371/journal.pone.0047367] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2012] [Accepted: 09/12/2012] [Indexed: 01/02/2023] Open
Abstract
Articular cartilage (AC) lacks ability to repair defects due to its avascular nature as healing process relies on cells being brought in by blood vessels. Multiple approaches have been taken to facilitate cartilage repair in clinics, to date there is no effective treatment available that can restores the AC lesion to a normally functioning level over extended periods. In this regard, antler cartilage is unique in being richly vascularised and hence can effectively repair and regenerate. Interestingly, antler stem cells, from which the vascularised cartilage is derived, can form avascular cartilage when taken away from their original niche, suggesting that the vascular or avascular state of antler cartilage is controlled by extrinsic factors. Understanding the mechanisms underlying this phenotype switch may help us to devise a way to trigger the effective intrinsic repair of AC. However, adoption of antler cartilage model for AC repair requires the demonstration that the cartilage specific signalling pathways also prevail in antler chondrogenesis. To achieve this, in the present study we silenced expression of Cbfa1, a key factor regulatingendochondral ossification, using RNAi, and showed that expression of the downstream genes type I collagen and osteocalcin were suppressed which, in turn, inhibited endochondral ossification process taking place in the antler stem cell-formed nodules. Therefore, we provided further evidence at molecular level that antler could be developed as novel model for the study of AC repair. The eventual identification of the extrinsic factors dictating the phenotype switch between the vascular and avascular state of antler cartilage will open up a new avenue for the cure of osteoarthritis.
Collapse
Affiliation(s)
- Hongmei Sun
- Institute of Special Wild Economic Animals and Plants, Chinese Academy of Agricultural Sciences, Changchun, Jilin, P. R. China
- State Key Laboratory for Molecular Biology of Special Economic Animals, Jilin, P. R. China
| | - Fuhe Yang
- Institute of Special Wild Economic Animals and Plants, Chinese Academy of Agricultural Sciences, Changchun, Jilin, P. R. China
- State Key Laboratory for Molecular Biology of Special Economic Animals, Jilin, P. R. China
| | - Wenhui Chu
- Institute of Special Wild Economic Animals and Plants, Chinese Academy of Agricultural Sciences, Changchun, Jilin, P. R. China
- State Key Laboratory for Molecular Biology of Special Economic Animals, Jilin, P. R. China
| | - Haiping Zhao
- Institute of Special Wild Economic Animals and Plants, Chinese Academy of Agricultural Sciences, Changchun, Jilin, P. R. China
- State Key Laboratory for Molecular Biology of Special Economic Animals, Jilin, P. R. China
| | - Chris McMahon
- AgResearch, Invermay Agricultural Centre, Mosgiel, New Zealand
| | - Chunyi Li
- AgResearch, Invermay Agricultural Centre, Mosgiel, New Zealand
- State Key Laboratory for Molecular Biology of Special Economic Animals, Jilin, P. R. China
- * E-mail:
| |
Collapse
|
113
|
Nishimura R, Wakabayashi M, Hata K, Matsubara T, Honma S, Wakisaka S, Kiyonari H, Shioi G, Yamaguchi A, Tsumaki N, Akiyama H, Yoneda T. Osterix regulates calcification and degradation of chondrogenic matrices through matrix metalloproteinase 13 (MMP13) expression in association with transcription factor Runx2 during endochondral ossification. J Biol Chem 2012; 287:33179-90. [PMID: 22869368 PMCID: PMC3460424 DOI: 10.1074/jbc.m111.337063] [Citation(s) in RCA: 125] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Revised: 07/27/2012] [Indexed: 11/06/2022] Open
Abstract
Endochondral ossification is temporally and spatially regulated by several critical transcription factors, including Sox9, Runx2, and Runx3. Although the molecular mechanisms that control the late stages of endochondral ossification (e.g. calcification) are physiologically and pathologically important, these precise regulatory mechanisms remain unclear. Here, we demonstrate that Osterix is an essential transcription factor for endochondral ossification that functions downstream of Runx2. The global and conditional Osterix-deficient mice studied here exhibited a defect of cartilage-matrix ossification and matrix vesicle formation. Importantly, Osterix deficiencies caused the arrest of endochondral ossification at the hypertrophic stage. Microarray analysis revealed that matrix metallopeptidase 13 (MMP13) is an important target of Osterix. We also showed that there exists a physical interaction between Osterix and Runx2 and that these proteins function cooperatively to induce MMP13 during chondrocyte differentiation. Most interestingly, the introduction of MMP13 stimulated the calcification of matrices in Osterix-deficient mouse limb bud cells. Our results demonstrated that Osterix was essential to endochondral ossification and revealed that the physical and functional interaction between Osterix and Runx2 were necessary for the induction of MMP13 during endochondral ossification.
Collapse
Affiliation(s)
- Riko Nishimura
- Department of Molecular and Cellular Biochemistry, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
114
|
Morrison NA, Stephens AA, Osato M, Polly P, Tan TC, Yamashita N, Doecke JD, Pasco J, Fozzard N, Jones G, Ralston SH, Sambrook PN, Prince RL, Nicholson GC. Glutamine repeat variants in human RUNX2 associated with decreased femoral neck BMD, broadband ultrasound attenuation and target gene transactivation. PLoS One 2012; 7:e42617. [PMID: 22912713 PMCID: PMC3418257 DOI: 10.1371/journal.pone.0042617] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Accepted: 07/09/2012] [Indexed: 12/28/2022] Open
Abstract
RUNX2 is an essential transcription factor required for skeletal development and cartilage formation. Haploinsufficiency of RUNX2 leads to cleidocranial displaysia (CCD) a skeletal disorder characterised by gross dysgenesis of bones particularly those derived from intramembranous bone formation. A notable feature of the RUNX2 protein is the polyglutamine and polyalanine (23Q/17A) domain coded by a repeat sequence. Since none of the known mutations causing CCD characterised to date map in the glutamine repeat region, we hypothesised that Q-repeat mutations may be related to a more subtle bone phenotype. We screened subjects derived from four normal populations for Q-repeat variants. A total of 22 subjects were identified who were heterozygous for a wild type allele and a Q-repeat variant allele: (15Q, 16Q, 18Q and 30Q). Although not every subject had data for all measures, Q-repeat variants had a significant deficit in BMD with an average decrease of 0.7SD measured over 12 BMD-related parameters (p = 0.005). Femoral neck BMD was measured in all subjects (-0.6SD, p = 0.0007). The transactivation function of RUNX2 was determined for 16Q and 30Q alleles using a reporter gene assay. 16Q and 30Q alleles displayed significantly lower transactivation function compared to wild type (23Q). Our analysis has identified novel Q-repeat mutations that occur at a collective frequency of about 0.4%. These mutations significantly alter BMD and display impaired transactivation function, introducing a new class of functionally relevant RUNX2 mutants.
Collapse
Affiliation(s)
- Nigel A Morrison
- School of Medical Sciences, Griffith University, Southport, Australia.
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
115
|
Ikeda K, Tsukui T, Imazawa Y, Horie-Inoue K, Inoue S. Conditional expression of constitutively active estrogen receptor α in chondrocytes impairs longitudinal bone growth in mice. Biochem Biophys Res Commun 2012; 425:912-7. [PMID: 22902633 DOI: 10.1016/j.bbrc.2012.07.170] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Accepted: 07/28/2012] [Indexed: 12/17/2022]
Abstract
Estrogen plays important roles in the regulation of chondrocyte proliferation and differentiation, which are essential steps for longitudinal bone growth; however, the mechanisms of estrogen action on chondrocytes have not been fully elucidated. In the present study, we generated conditional transgenic mice, designated as caERα(ColII), expressing constitutively active mutant estrogen receptor (ER) α in chondrocytes, using the chondrocyte-specific type II collagen promoter-driven Cre transgenic mice. caERα(ColII) mice showed retardation in longitudinal growth, with short bone lengths. BrdU labeling showed reduced proliferation of hypertrophic chondrocytes in the proliferating layer of the growth plate of tibia in caERα(ColII) mice. In situ hybridization analysis of type X collagen revealed that the maturation of hypertrophic chondrocytes was impaired in caERα(ColII) mice. These results suggest that ERα is a critical regulator of chondrocyte proliferation and maturation during skeletal development, mediating longitudinal bone growth in vivo.
Collapse
Affiliation(s)
- Kazuhiro Ikeda
- Division of Gene Regulation and Signal Transduction, Research Center for Genomic Medicine, Saitama Medical University, Saitama, Japan
| | | | | | | | | |
Collapse
|
116
|
Guang LG, Boskey AL, Zhu W. Regulatory role of stromal cell-derived factor-1 in bone morphogenetic protein-2-induced chondrogenic differentiation in vitro. Int J Biochem Cell Biol 2012; 44:1825-33. [PMID: 22771956 DOI: 10.1016/j.biocel.2012.06.033] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Revised: 06/22/2012] [Accepted: 06/27/2012] [Indexed: 12/18/2022]
Abstract
Chemokine stromal cell-derived factor-1 (SDF-1) signals via binding to its primary transmembrane receptor, cysteine (C)-X-C chemokine receptor-4 (CXCR4). We previously reported that SDF-1 regulates osteogenic differentiation of mesenchymal stem/progenitor cells (MPCs) induced by bone morphogenetic protein-2 (BMP2). Although BMP2 is also capable of inducing chondrogenic differentiation of MPCs, the involvement of SDF-1 signaling in this function of BMP2 remains unknown. In this study, we aimed to test the role of SDF-1 signaling involved in BMP2-induced chondrogenic differentiation, using ATDC5 chondroprogenitors and mouse bone marrow-derived mesenchymal stromal cells (BMSCs). Our data showed that blocking of the SDF-1/CXCR4 pathway inhibits the differentiation of these cells into the chondrocytic lineages in response to BMP2 stimulation, evidenced by the reduced expression of type II collagen α1 (Col2α1), aggrecan, and type X collagen α1 (Col10α1), markers for chondrogenic differentiation. This effect of blocking SDF-1 signaling on BMP2-chondrogenic differentiation is associated with suppressed Sox9 and Runx2 expression (key transcription factors required for early and late stages of chondrogenic differentiation, respectively) and mediated via inhibiting intracellular Smad and Erk activation. Moreover, we found that addition of exogenous SDF-1 protein synergistically enhances the BMP2-induced chondrogenic differentiation in a dose-dependent manner. Collectively, our results demonstrated a novel role of SDF-1 signaling in regulating BMP2-induced chondrogenic differentiation in vitro. These data provide new insights into molecular mechanisms underlying BMP2-osteo/chondrogenesis, and may lead to the identification of new therapeutic targets and strategies to improve cartilage repair and regeneration in broad orthopaedic situations.
Collapse
Affiliation(s)
- Liang G Guang
- Musculoskeletal Integrity Program, Hospital for Special Surgery, New York, NY 10021, USA
| | | | | |
Collapse
|
117
|
Kawamura I, Maeda S, Imamura K, Setoguchi T, Yokouchi M, Ishidou Y, Komiya S. SnoN suppresses maturation of chondrocytes by mediating signal cross-talk between transforming growth factor-β and bone morphogenetic protein pathways. J Biol Chem 2012; 287:29101-13. [PMID: 22767605 DOI: 10.1074/jbc.m112.349415] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Hypertrophic maturation of chondrocytes is a crucial step in endochondral ossification, whereas abnormally accelerated differentiation of hypertrophic chondrocytes in articular cartilage is linked to pathogenesis of osteoarthritis. This cellular process is promoted or inhibited by bone morphogenetic protein (BMP) or transforming growth factor-β (TGF-β) signaling, respectively, suggesting that these signaling pathways cross-talk during chondrocyte maturation. Here, we demonstrated that expression of Tgfb1 was increased, followed by phosphorylation of Smad2, during BMP-2-induced hypertrophic maturation of ATDC5 chondrocytes. Application of a TGF-β type I receptor inhibitor compound, SB431542, increased the expression of Id1, without affecting the phosphorylation status of Smad1/5/8, indicating that the activated endogenous TGF-β pathway inhibited BMP signaling downstream of the Smad activation step. We searched for TGF-β-inducible effectors that are able to inhibit BMP signaling in ATDC5 cells and identified SnoN. Overexpression of SnoN suppressed the activity of a BMP-responsive luciferase reporter in COS-7 cells as well as expression of Id1 in ATDC5 cells and, subsequently, the expression of Col10a1, a hallmark of hypertrophic chondrocyte maturation. siRNA-mediated loss of SnoN showed opposite effects in BMP-treated ATDC5 cells. In adult mice, we found the highest level of SnoN expression in articular cartilage. Importantly, SnoN was expressed, in combination with phosphorylated Smad2/3, in prehypertrophic chondrocytes in the growth plate of mouse embryo bones and in chondrocytes around the ectopically existing hypertrophic chondrocytes of human osteoarthritis cartilage. Our results indicate that SnoN mediates a negative feedback mechanism evoked by TGF-β to inhibit BMP signaling and, subsequently, hypertrophic maturation of chondrocytes.
Collapse
Affiliation(s)
- Ichiro Kawamura
- Department of Medical Joint Materials, Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima University, Kagoshima 890-8544, Japan
| | | | | | | | | | | | | |
Collapse
|
118
|
Liu Q, Wan Q, Yang R, Zhou H, Li Z. Effects of intermittent versus continuous parathyroid hormone administration on condylar chondrocyte proliferation and differentiation. Biochem Biophys Res Commun 2012; 424:182-8. [PMID: 22750004 DOI: 10.1016/j.bbrc.2012.06.106] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2012] [Accepted: 06/20/2012] [Indexed: 11/16/2022]
Abstract
Endochondral ossification is a complex process involving chondrogenesis and osteogenesis regulated by many hormones and growth factors. Parathyroid hormone (PTH), one of the key hormones regulating bone metabolism, promotes osteoblast differentiation and osteogenesis by intermittent administration, whereas continuous PTH administration inhibits bone formation. However, the effects of PTH on chondrocyte proliferation and differentiation are still unclear. In this study, intermittent PTH administration presented enhanced effects on condylar chondrocyte differentiation and bone formation, as demonstrated by increased mineral nodule formation and alkaline phosphatase (ALP) activity, up-regulated runt-related transcription factor 2 (RUNX2), ALP, collagen type X (COL10a1), collagen type I (COL1a1), osteocalcin (OCN), bone sialoprotein (BSP), bone morphogenetic protein 2 (BMP2) and osterix (OSX) mRNA and/or protein expression. On the contrary, continuous PTH administration promoted condylar chondrocyte proliferation and suppressed its differentiation, as demonstrated by up-regulated collagen type II (COL2a1) mRNA expression, reduced mineral nodule formation and down-regulated expression of the mRNAs and/or proteins mentioned above. Our data suggest that PTH can regulate condylar chondrocyte proliferation and differentiation, depending on the type of PTH administration. These results provide new insight into the effects of PTH on condylar chondrocytes and new evidence for using local PTH administration to cure mandibular asymmetry.
Collapse
Affiliation(s)
- Qi Liu
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST), School & Hospital of Stomatology, Wuhan University, 237# Luoyu Road, Wuhan 430079, China
| | | | | | | | | |
Collapse
|
119
|
Ionescu A, Kozhemyakina E, Nicolae C, Kaestner KH, Olsen BR, Lassar AB. FoxA family members are crucial regulators of the hypertrophic chondrocyte differentiation program. Dev Cell 2012; 22:927-39. [PMID: 22595668 PMCID: PMC3356573 DOI: 10.1016/j.devcel.2012.03.011] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2011] [Revised: 12/30/2011] [Accepted: 03/26/2012] [Indexed: 12/01/2022]
Abstract
During endochondral ossification, small, immature chondrocytes enlarge to form hypertrophic chondrocytes, which express collagen X. In this work, we demonstrate that FoxA factors are induced during chondrogenesis, bind to conserved binding sites in the collagen X enhancer, and can promote the expression of a collagen X-luciferase reporter in both chondrocytes and fibroblasts. In addition, we demonstrate by both gain- and loss-of-function analyses that FoxA factors play a crucial role in driving the expression of both endogenous collagen X and other hypertrophic chondrocyte-specific genes. Mice engineered to lack expression of both FoxA2 and FoxA3 in their chondrocytes display defects in chondrocyte hypertrophy, alkaline phosphatase expression, and mineralization in their sternebrae and, in addition, exhibit postnatal dwarfism that is coupled to significantly decreased expression of both collagen X and MMP13 in their growth plates. Our findings indicate that FoxA family members are crucial regulators of the hypertrophic chondrocyte differentiation program.
Collapse
Affiliation(s)
- Andreia Ionescu
- Department of Biological Chemistry and Molecular Pharmacology Harvard Medical School 240 Longwood Ave. Boston, MA. 02115
| | - Elena Kozhemyakina
- Department of Biological Chemistry and Molecular Pharmacology Harvard Medical School 240 Longwood Ave. Boston, MA. 02115
| | - Claudia Nicolae
- Department of Developmental Biology Harvard School of Dental Medicine 188 Longwood Avenue, Boston, MA 02115
| | - Klaus H. Kaestner
- Dept. of Genetics Institute of Diabetes, Obesity & Metabolism Perelman School of Medicine University of Pennsylvania 3400 Civic Center Blvd. Philadelphia, PA 19104-6145
| | - Bjorn R. Olsen
- Department of Developmental Biology Harvard School of Dental Medicine 188 Longwood Avenue, Boston, MA 02115
| | - Andrew B. Lassar
- Department of Biological Chemistry and Molecular Pharmacology Harvard Medical School 240 Longwood Ave. Boston, MA. 02115
| |
Collapse
|
120
|
Pass C, MacRae VE, Huesa C, Faisal Ahmed S, Farquharson C. SOCS2 is the critical regulator of GH action in murine growth plate chondrogenesis. J Bone Miner Res 2012; 27:1055-66. [PMID: 22228213 DOI: 10.1002/jbmr.1544] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Suppressor of Cytokine Signaling-2 (SOCS2) is a negative regulator of growth hormone (GH) signaling and bone growth via inhibition of the Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway. This has been classically demonstrated by the overgrowth phenotype of SOCS2(-/-) mice, which has normal systemic insulin-like growth factor 1 (IGF-1) levels. The local effects of GH on bone growth are equivocal, and therefore this study aimed to understand better the SOCS2 signaling mechanisms mediating the local actions of GH on epiphyseal chondrocytes and bone growth. SOCS2, in contrast to SOCS1 and SOCS3 expression, was increased in cultured chondrocytes after GH challenge. Gain- and loss-of-function studies indicated that GH-stimulated chondrocyte STATs-1, -3, and -5 phosphorylation was increased in SOCS2(-/-) chondrocytes but not in cells overexpressing SOCS2. This increased chondrocyte STAT signaling in the absence of SOCS2 is likely to explain the observed GH stimulation of longitudinal growth of cultured SOCS2(-/-) embryonic metatarsals and the proliferation of chondrocytes within. Consistent with this metatarsal data, bone growth rates, growth plate widths, and chondrocyte proliferation were all increased in SOCS2(-/-) 6-week-old mice as was the number of phosphorylated STAT-5-positive hypertrophic chondrocytes. The SOCS2(-/-) mouse represents a valid model for studying the local effects of GH on bone growth.
Collapse
Affiliation(s)
- Chloe Pass
- Bone Biology Group, Division of Developmental Biology, The Roslin Institute and Royal (Dick) School of Veterinary Studies, The University of Edinburgh, Roslin, Midlothian, UK
| | | | | | | | | |
Collapse
|
121
|
Takimoto A, Oro M, Hiraki Y, Shukunami C. Direct conversion of tenocytes into chondrocytes by Sox9. Exp Cell Res 2012; 318:1492-507. [PMID: 22510437 DOI: 10.1016/j.yexcr.2012.04.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Revised: 03/05/2012] [Accepted: 04/02/2012] [Indexed: 11/19/2022]
Abstract
Sox9 is a high-mobility group box-containing transcription factor that functions as a key regulator of chondrogenesis. We here report that Sox9 mediates the direct conversion of tenocytes to chondrocytes through an intermediate state in which both differentiation programs are active. Sox9 is abundantly expressed in cartilage but is undetectable in limb tendons that express Scleraxis (Scx) and Tenomodulin (Tnmd), tendon-specific early and late molecular markers, respectively. Upon forced expression of Sox9 in the chick forelimb, ectopic cartilage formation is preferentially observed in fibrous tissues including the tendons, ligaments, perichondrium/periosteum, dermis, and muscle connective tissues. Tnmd expression in tenocytes isolated from leg tendons was markedly upregulated by forced expression of basic helix-loop-helix (b-HLH) activators including Scx, Paraxis, Twist1 and Twist2. In contrast, the overexpression of Sox9 in monolayer tenocytes resulted in the downregulation of Tnmd and Scx expressions during passaging in culture, and the induction of cartilage molecular markers such as type II collagen (Col2a1) and Chondromodulin-I (ChM-I). This Sox9-driven switching from a tenocytic to a chondrocytic gene expression profile was associated with a dramatic change from a spindle to a polygonal cellular morphology. The extracellular accumulation of cartilage-characteristic proteoglycans was also observed. These data suggest that tenocytes have a strong potential for conversion into chondrocytes through the activities of Sox9 both in vitro and in vivo.
Collapse
Affiliation(s)
- Aki Takimoto
- Department of Cellular Differentiation, Institute for Frontier Medical Sciences, Kyoto University, Kyoto 606-8507, Japan
| | | | | | | |
Collapse
|
122
|
|
123
|
Milner PI, Clegg PD, Stewart MC. Stem cell-based therapies for bone repair. Vet Clin North Am Equine Pract 2012; 27:299-314. [PMID: 21872760 DOI: 10.1016/j.cveq.2011.05.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
This article provides an overview of the cellular and molecular events involved in bone repair and the current approaches to using stem cells as an adjunct to this process. The article emphasizes the key role of osteoprogenitor cells in the formation of bone and where the clinical applications of current research may lend themselves to large animal orthopaedics. The processes involved in osteogenic differentiation are presented and strategies for bone formation, including induction by osteogenic factors, bioscaffolds, and gene therapy, are reviewed.
Collapse
Affiliation(s)
- Peter I Milner
- Department of Musculoskeletal Biology, University of Liverpool, Leahurst Campus, Chester High Road, Neston, Cheshire, CH64 7TE, UK.
| | | | | |
Collapse
|
124
|
Stem cells and gene therapy for cartilage repair. Stem Cells Int 2012; 2012:168385. [PMID: 22481959 PMCID: PMC3306906 DOI: 10.1155/2012/168385] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2011] [Accepted: 12/06/2011] [Indexed: 01/06/2023] Open
Abstract
Cartilage defects represent a common problem in orthopaedic practice. Predisposing factors include traumas, inflammatory conditions, and biomechanics alterations. Conservative management of cartilage defects often fails, and patients with this lesions may need surgical intervention. Several treatment strategies have been proposed, although only surgery has been proved to be predictably effective. Usually, in focal cartilage defects without a stable fibrocartilaginous repair tissue formed, surgeons try to promote a natural fibrocartilaginous response by using marrow stimulating techniques, such as microfracture, abrasion arthroplasty, and Pridie drilling, with the aim of reducing swelling and pain and improving joint function of the patients. These procedures have demonstrated to be clinically useful and are usually considered as first-line treatment for focal cartilage defects. However, fibrocartilage presents inferior mechanical and biochemical properties compared to normal hyaline articular cartilage, characterized by poor organization, significant amounts of collagen type I, and an increased susceptibility to injury, which ultimately leads to premature osteoarthritis (OA). Therefore, the aim of future therapeutic strategies for articular cartilage regeneration is to obtain a hyaline-like cartilage repair tissue by transplantation of tissues or cells. Further studies are required to clarify the role of gene therapy and mesenchimal stem cells for management of cartilage lesions.
Collapse
|
125
|
Feng J, Zhao N, Zhao J, Rabie AB, Shen G. Orthopedic protraction of the maxilla may affect cranial base synchondroses indicated by increased expressions of growth factors. Orthod Craniofac Res 2012; 15:62-70. [PMID: 22264328 DOI: 10.1111/j.1601-6343.2011.01537.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVES To examine the biological adaptation of cranial base synchondroses (CBS) when the maxilla was forward positioned by orthopedic force. SETTING AND SAMPLE POPULATION The Department of Orthodontics at Shanghai Jiao Tong University. 50 Sprague-Dawley rats, 4 weeks of age, were divided into experimental (n=30) and control groups (n=20). MATERIAL AND METHODS An orthopedic appliance was fitted to the cranio-maxillary complex to advance the maxilla forward. The animals in the experimental group, together with the counterparts in the control group, were sacrificed at days 1, 3, 5, 7, and 14, respectively. The whole cranial base housing both the spheno-ethmoid (SES) and spheno-occipital synchondroses (SOS) was removed for tissue processing and immunotest of Sox9, Core-binding factor α 1 (Cbfa1), and vascular endothelial growth factor (VEGF), three carefully selected growth factors that are markers of chondrogenesis in different stages and its transition to endochondral ossification. Semiquantitative analysis was also conducted by using a computerizing imaging system. RESULTS The temporal tendency of the changes in the expressions of the three growth factors featured an increase from Day 3 and onwards for Cbfa1 and VEGF, and a following decline after Day 5 for Sox9. In both SES and SOS, the expressions of the three growth factors were significantly stronger in the experimental groups than that in groups (p<0.05). CONCLUSIONS Protractive orthopedic force imposed on the maxilla provokes an enhancement of chondrogenic process in CBS.
Collapse
Affiliation(s)
- J Feng
- Department of Orthodontics, College of Stomatology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University, Shanghai, China
| | | | | | | | | |
Collapse
|
126
|
Orfanidou T, Iliopoulos D, Malizos KN, Tsezou A. Involvement of SOX-9 and FGF-23 in RUNX-2 regulation in osteoarthritic chondrocytes. J Cell Mol Med 2011; 13:3186-94. [PMID: 20196777 PMCID: PMC4516476 DOI: 10.1111/j.1582-4934.2009.00678.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Chondrocytes’ hypertrophy includes metabolic changes, matrix remodelling, proliferation and apoptosis, characteristics associated with the progression of osteoarthritis. We investigated a possible association among Runt-related transcription factor 2 (RUNX-2), SOX-9 and fibroblast growth factor (FGF)-23 mRNA expressions in articular chondrocytes in order to elucidate their contribution in the osteoarthritic hypertrophic cartilage. SOX-9, FGF-23, RUNX-2 and matrix metalloproteinase (MMP)-13 mRNA expressions were evaluated in osteoarthritic and normal chondrocytes by real-time PCR whereas MMP-13 protein expression by immunofluorescense. RUNX-2, FGF-23 and SOX-9 were down-regulated using small interfering RNA technology and transfection with liposomes. The effect of human recombinant FGF-23 (hrFGF-23) on SOX-9 and RUNX-2 expression was tested in normal chondrocytes. We found higher expression of RUNX-2 and FGF-23 and a decreased expression of SOX-9 mRNA in osteoarthritic chondrocytes compared to normal (P < 0.0001). RUNX-2 down-regulation resulted in reduced MMP-13 expression in osteoarthritic chondrocytes and inhibition of SOX-9 in increased RUNX-2 and MMP-13 mRNA expression in normal chondrocytes, whereas inhibition of FGF-23 resulted in reduced RUNX-2 mRNA expression in osteoarthritic chondrocytes (all P < 0.0001). Silencing of RUNX-2 or FGF-23 did not affect SOX-9 mRNA levels in osteoarthritic chondrocytes. Moreover simultaneous down-regulation of SOX-9 and up-regulation of FGF-23 mRNA expressions in normal chondrocytes resulted in additive up-regulation of RUNX-2 mRNA expression. Treatment of normal chondrocytes with hrFGF-23 resulted in increased RUNX-2 mRNA expression, whereas it had no effect on SOX-9 mRNA expression. We demonstrated convincing associations among RUNX-2, SOX-9 and FGF-23 in relation to MMP-13 expression in osteoarthritic chondrocytes, contributing to a better understanding of the abnormal gene expression and cartilage degeneration processes associated with osteoarthritis.
Collapse
Affiliation(s)
- Timoklia Orfanidou
- Laboratory of Cytogenetics and Medical Genetics, University of Thessaly, Medical School, Larissa, Greece
| | | | | | | |
Collapse
|
127
|
Maeno T, Moriishi T, Yoshida CA, Komori H, Kanatani N, Izumi SI, Takaoka K, Komori T. Early onset of Runx2 expression caused craniosynostosis, ectopic bone formation, and limb defects. Bone 2011; 49:673-82. [PMID: 21807129 DOI: 10.1016/j.bone.2011.07.023] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Revised: 07/07/2011] [Accepted: 07/13/2011] [Indexed: 11/23/2022]
Abstract
RUNX2 is an essential transcription factor for osteoblast differentiation, because osteoblast differentiation is completely blocked in Runx2-deficient mice. However, it remains to be clarified whether RUNX2 is sufficient for osteoblast differentiation during embryogenesis. To address this issue, Runx2 transgenic mice were generated under the control of the Prrx1 promoter, which directs the transgene expression to mesenchymal cells before the onset of bone development. The transgene expression was detected in the cranium, limb buds, and the region from the mandible to anterior chest wall. The skull became small and the limbs were shortened depending on the levels of the transgene expression. Early onset of Runx2 expression in the cranial mesenchyme induced mineralization on E13.0, when no mineralization was observed in wild-type mice, and resulted in craniosynostosis as shown by the closure of sutures and fontanelles on E18.5. Col1a1 and Spp1 expressions were detected in the mineralized regions on E12.5-13.5. The limb bones were hypoplastic and fused, and ectopic bones were formed in the hands and feet. Col2a1 expression was inhibited but Col1a1 expression was induced in the limb buds on E12.5. In the anterior chest wall, ectopic bones were formed through the process of intramembranous ossification, interrupting the formation of cartilaginous anlagen of sternal manubrium. These findings indicate that RUNX2 is sufficient to direct mesenchymal cells to osteoblasts and lead to intramembranous bone formation during embryogenesis; Runx2 inhibits chondrocyte differentiation at an early stage; and that Runx2 expression at appropriate level, times and spaces during embryogenesis is essential for skeletal development.
Collapse
Affiliation(s)
- Takafumi Maeno
- Department of Cell Biology, Unit of Basic Medical Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8588, Japan
| | | | | | | | | | | | | | | |
Collapse
|
128
|
Kinning E, McDevitt H, Duncan R, Ahmed SF. A multidisciplinary approach to understanding skeletal dysplasias. Expert Rev Endocrinol Metab 2011; 6:731-743. [PMID: 30780879 DOI: 10.1586/eem.11.61] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The skeletal dysplasias are a heterogeneous group of conditions of abnormal cartilage and bone development, resulting in a wide range of phenotypes of variable severity from perinatal lethality to mild short stature. Elucidation of the molecular mechanisms underlying these disorders is allowing us to understand more about the etiology of these conditions and classify them based upon the underlying gene defect. This article will discuss the development of bone and cartilage in relation to these conditions, present a clinical approach to their diagnosis and management, and consider new avenues of therapy.
Collapse
Affiliation(s)
- Esther Kinning
- a Department of Clinical Genetics, Ferguson Smith Centre, Royal Hospital for Sick Children (Yorkhill), Dalnair Street, Glasgow, G3 8SJ, UK.
| | - Helen McDevitt
- b Department of Neonatology, Royal Hospital for Sick Children (Yorkhill), Dalnair Street, Glasgow, G3 8SJ, UK
| | - Rod Duncan
- c Department of Orthopaedics, Royal Hospital for Sick Children (Yorkhill), Dalnair Street, Glasgow, G3 8SJ, UK
| | - S Faisal Ahmed
- d Department of Child Health, University of Glasgow, Royal Hospital for Sick Children (Yorkhill), Dalnair Street, Glasgow, G3 8SJ, UK
| |
Collapse
|
129
|
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.
Collapse
Affiliation(s)
- Julie C Liu
- Department of Cell Biology and Cancer Center, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
130
|
Chen W, Zhang X, Siu RK, Chen F, Shen J, Zara JN, Culiat CT, Tetradis S, Ting K, Soo C. Nfatc2 is a primary response gene of Nell-1 regulating chondrogenesis in ATDC5 cells. J Bone Miner Res 2011; 26:1230-41. [PMID: 21611965 PMCID: PMC3312756 DOI: 10.1002/jbmr.314] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2010] [Revised: 10/30/2010] [Accepted: 12/01/2010] [Indexed: 01/05/2023]
Abstract
Nell-1 is a growth factor required for normal skeletal development and expression of extracellular matrix proteins required for bone and cartilage cell differentiation. We identified the transcription factor nuclear factor of activated T cells (Nfatc2) as a primary response gene of Nell-1 through a microarray screen, with validation using real-time polymerase chain reaction (PCR). We investigated the effects of recombinant Nell-1 protein on the chondrogenic cell line ATDC5 and primary mouse chondrocytes. The osteochondral transcription factor Runx2 was investigated as a possible intermediary between Nell-1 and Nfatc2 using adenoviral overexpression of wild-type and dominant-negative Runx2. Nell-1 transiently induced both transcription and translation of Nfatc2, an effect inhibited by transduction of dominant-negative Runx2, suggesting that Runx2 was necessary for Nfatc2 induction. Differentiation assays revealed inhibitory effects of Nell-1 on ATDC5 cells. Although proliferation was unaffected, expression of chondrocyte-specific genes was decreased, and cartilage nodule formation and proteoglycan accumulation were suppressed. siRNA knockdown of Nfatc2 significantly reversed these inhibitory effects. To elucidate the relationship between Nell-1, Runx2, and Nfatc2 in vivo, their presence and distribution were visualized in femurs of wild-type and Nell1-deficient mice at both neonatal and various developmental stages using immunohistochemistry. All three proteins colocalized in the perichondrium of wild-type femurs but stained weakly or were completely absent in Nell1-deficient femurs at neonatal stages. Thus Nfatc2 likely plays an important role in Nell-1-mediated osteochondral differentiation in vitro and in vivo. To our knowledge, this is the first demonstration that Nfatc2 is a primary response gene of Nell-1.
Collapse
Affiliation(s)
- Weiwei Chen
- Zhejiang California International NanoSystems Institute, Zhejiang University, Hangzhou, Zhejiang, People’s Republic of China
- Dental and Craniofacial Research Institute, University of California Los Angeles, Los Angeles, CA, USA
| | - Xinli Zhang
- Dental and Craniofacial Research Institute, University of California Los Angeles, Los Angeles, CA, USA
| | - Ronald K Siu
- Department of Biomedical Engineering, University of California Los Angeles, Los Angeles, CA, USA
| | - Feng Chen
- Dental and Craniofacial Research Institute, University of California Los Angeles, Los Angeles, CA, USA
| | - Jia Shen
- Dental and Craniofacial Research Institute, University of California Los Angeles, Los Angeles, CA, USA
| | - Janette N Zara
- Department of Biomedical Engineering, University of California Los Angeles, Los Angeles, CA, USA
| | - Cymbeline T Culiat
- Life Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Sotirios Tetradis
- Division of Surgical and Diagnostic Sciences, Section of Oral Radiology, University of California Los Angeles, Los Angeles, CA, USA
| | - Kang Ting
- Dental and Craniofacial Research Institute, University of California Los Angeles, Los Angeles, CA, USA
- Section of Orthodontics, School of Dentistry, University of California Los Angeles, Los Angeles, CA, USA
| | - Chia Soo
- Department of Orthopaedic Surgery, University of California Los Angeles, Los Angeles, CA, USA
| |
Collapse
|
131
|
He N, Xiao Z, Yin T, Stubbs J, Li L, Quarles LD. Inducible expression of Runx2 results in multiorgan abnormalities in mice. J Cell Biochem 2011; 112:653-65. [PMID: 21268087 DOI: 10.1002/jcb.22968] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Runx2 is a transcription factor controlling skeletal development, and is also expressed in extraskeletal tissues where its function is not well understood. Existing Runx2 mutant and transgenic mouse models do not allow the necessary control of Runx2 expression to understand its functions in different tissues. We generated conditional, doxycyline-inducible, triple transgenic mice (CMV-Cre;ROSA26-neo(flox/+)-rtTA;Tet-O-Runx2) to investigate the effects of wide spread overexpression of Runx2. Osteoblasts isolated from CMV-Cre;ROSA26-neo(flox/+)-rtTA; Tet-O-Runx2 mice demonstrated a dose-dependent effect of doxycycline to stimulate Runx2 transgene expression. Doxycycline administration to CMV-Cre;ROSA26-neo(flox/+)-rtTA;Tet-O-Runx2 mice induced Runx2 transgene expression in all tissues tested, with the highest levels observed in kidney, ovary, and bone. Runx2 overexpression resulted in deceased body size and reduced viability. With regard to bone, Runx2 overexpressing mice paradoxically displayed profound osteopenia and diminished osteogenesis. Induced expression of Runx2 in extraskeletal tissues resulted in ectopic calcification and induction of the osteogenic program in a limited number of tissues, including lung and muscle. In addition, the triple transgenic mice showed evidence of a myeloproliferative disorder and an apparent inhibition of lymphocyte development. Thus, overexpression of Runx2 both within and outside of the skeleton can have diverse biological effects. Use of tissue specific Cre mice will allow this model to be used to conditionally and inducibly overexpress Runx2 in different tissues and provide a means to study the post-natal tissue- and cell context-dependent functions of Runx2.
Collapse
Affiliation(s)
- Nan He
- The Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
| | | | | | | | | | | |
Collapse
|
132
|
Mikasa M, Rokutanda S, Komori H, Ito K, Tsang YS, Date Y, Yoshida CA, Komori T. Regulation of Tcf7 by Runx2 in chondrocyte maturation and proliferation. J Bone Miner Metab 2011; 29:291-9. [PMID: 20890621 DOI: 10.1007/s00774-010-0222-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2010] [Accepted: 08/08/2010] [Indexed: 10/19/2022]
Abstract
Runx2 plays important roles in the regulation of chondrocyte differentiation and proliferation; however, the Runx2 target molecules still remain to be investigated. We searched the genes upregulated by the introduction of Runx2 into Runx2(-/-) chondrocytes using microarray and found that Tcf7 is upregulated by Runx2. Thus, we examined the functions of Runx2 in the regulation of the Tcf/Lef family of transcription factors. Runx2 induced Tcf7 and Lef1 strongly, but Tcf7l1 and Tcf7l2 only slightly in Runx2(-/-) chondrocytes; the expressions of Tcf7 and Tcf7l2 were reduced in Runx2(-/-) cartilaginous skeletons and calvaria, and Tcf7 showed a similar expression pattern to Runx2. In reporter assays, Runx2 mildly activated the 8.6 and 1.8 kb Tcf7 promoter constructs. The reporter assays using the deletion constructs of the 1.8-kb fragment showed that the 0.3-kb promoter region is responsible for the Runx2-dependent transcriptional activation. To investigate the function of Tcf7 in skeletal development, we generated dominant-negative (dn) Tcf7 transgenic mice using the Col2a1 promoter. Dn-Tcf7 transgenic embryos showed dwarfism, and mineralization was retarded in limbs, ribs, and vertebrae in a manner dependent on the expression levels of the transgene. In situ hybridization analysis showed that endochondral ossification is retarded in dn-Tcf7 transgenic embryos due to the decelerated chondrocyte maturation. Further, BrdU labeling showed a reduction in chondrocyte proliferation in the proliferating layer of the growth plate in dn-Tcf7 transgenic embryos. These findings indicate that Runx2 regulates chondrocyte maturation and proliferation at least partly through the induction of Tcf7.
Collapse
Affiliation(s)
- Masaki Mikasa
- Department of Cell Biology, Unit of Basic Medical Sciences, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki 852-8588, Japan
| | | | | | | | | | | | | | | |
Collapse
|
133
|
Maye P, Fu Y, Butler DL, Chokalingam K, Liu Y, Floret J, Stover ML, Wenstrup R, Jiang X, Gooch C, Rowe D. Generation and characterization of Col10a1-mcherry reporter mice. Genesis 2011; 49:410-8. [PMID: 21328521 PMCID: PMC5638041 DOI: 10.1002/dvg.20733] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
We report here on the generation of a new fluorescent protein reporter transgenic mouse line, Col10a1-mCherry, which can be used as a tool to study chondrocyte biology and pathology. Collagen, Type X, alpha 1 (Col10a1) is highly expressed in hypertrophic chondrocytes and commonly used as a gene marker for this cell population. The Col10a1-mCherry reporter line was generated using a bacterial recombination strategy with the mouse BAC clone RP23-192A7. To aid in the characterization of this animal model, we intercrossed Col10a1-mCherry mice with Collagen, Type II, alpha 1 (Col2a1) enhanced cyan fluorescent protein (ECFP) reporter mice and characterized the expression of both chondrocyte reporters during embryonic skeletal development from days E10.5 to E17.5. Additionally, at postnatal day 0, Col10a1-mCherry reporter expression was compared to endogenous Col10a1 mRNA expression in long bones and revealed that mCherry fluorescence extended past the Col10a1 expression domain. However, in situ hybridization for mCherry was consistent with the zone of Col10a1 mRNA expression, indicating that the persistent detection of mCherry fluorescence was a result of the long protein half life of mCherry in conjunction with a very rapid phase of skeletal growth and not due to aberrant transcriptional regulation. Taking advantage of the continued fluorescence of hypertrophic chondrocytes at the chondro-osseus junction, we intercrossed Col10a1-mCherry mice with two different Collagen, Type 1, alpha 1, (Col1a1) osteoblast reporter mice, pOBCol3.6-Topaz and pOBCol2.3-Emerald to investigate the possibility that hypertrophic chondrocytes transdifferentiate into osteoblasts. Evaluation of long bones at birth suggests that residual hypertrophic chondrocytes and osteoblasts in the trabecular zone exist as two completely distinct cell populations. genesis 49:410-418, 2011.
Collapse
Affiliation(s)
- Peter Maye
- Department of Reconstructive Sciences, School of Dental Medicine, University of Connecticut Health Center, Farmington, Connecticut 06030, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
134
|
Suwanwela J, Farber CR, Haung BL, Song B, Pan C, Lyons KM, Lusis AJ. Systems genetics analysis of mouse chondrocyte differentiation. J Bone Miner Res 2011; 26:747-60. [PMID: 20954177 PMCID: PMC3179327 DOI: 10.1002/jbmr.271] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
One of the goals of systems genetics is the reconstruction of gene networks that underlie key processes in development and disease. To identify cartilage gene networks that play an important role in bone development, we used a systems genetics approach that integrated microarray gene expression profiles from cartilage and bone phenotypic data from two sets of recombinant inbred strains. Microarray profiles generated from isolated chondrocytes were used to generate weighted gene coexpression networks. This analysis resulted in the identification of subnetworks (modules) of coexpressed genes that then were examined for relationships with bone geometry and density. One module exhibited significant correlation with femur length (r = 0.416), anteroposterior diameter (r = 0.418), mediolateral diameter (r = 0.576), and bone mineral density (r = 0.475). Highly connected genes (n = 28) from this and other modules were tested in vitro using prechondrocyte ATDC5 cells and RNA interference. Five of the 28 genes were found to play a role in chondrocyte differentiation. Two of these, Hspd1 and Cdkn1a, were known previously to function in chondrocyte development, whereas the other three, Bhlhb9, Cugbp1, and Spcs3, are novel genes. Our integrative analysis provided a systems-level view of cartilage development and identified genes that may be involved in bone development.
Collapse
Affiliation(s)
- Jaijam Suwanwela
- Department of Oral Biology, School of Dentistry, UCLA, Los Angeles, CA 90095, USA.
| | | | | | | | | | | | | |
Collapse
|
135
|
Abstract
RUNX2 is an essential transcription factor for osteoblast differentiation and chondrocyte maturation. SP7, another transcription factor, is required for osteoblast differentiation. Major signaling pathways, including FGF, Wnt, and IHH, also play important roles in skeletal development. RUNX2 regulates Sp7 expression at an early stage of osteoblast differentiation. FGF2 upregulates Runx2 expression and activates RUNX2, and gain-of-function mutations of FGFRs cause craniosynostosis and limb defect with upregulation of Runx2 expression. Wnt signaling upregulates Runx2 expression and activates RUNX2, and RUNX2 induces Tcf7 expression. IHH is required for Runx2 expression in osteoprogenitor cells during endochondral bone development, and RUNX2 directly regulates Ihh expression in chondrocytes. Thus, RUNX2 regulates osteoblast differentiation and chondrocyte maturation through the network with SP7 and with FGF, Wnt, and IHH signaling pathways during skeletal development.
Collapse
Affiliation(s)
- Toshihisa Komori
- Department of Cell Biology, Unit of Basic Medical Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8588, Japan.
| |
Collapse
|
136
|
Goldring MB, Otero M, Plumb DA, Dragomir C, Favero M, El Hachem K, Hashimoto K, Roach HI, Olivotto E, Borzì RM, Marcu KB, Marcu KB. Roles of inflammatory and anabolic cytokines in cartilage metabolism: signals and multiple effectors converge upon MMP-13 regulation in osteoarthritis. Eur Cell Mater 2011; 21:202-20. [PMID: 21351054 PMCID: PMC3937960 DOI: 10.22203/ecm.v021a16] [Citation(s) in RCA: 342] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Human cartilage is a complex tissue of matrix proteins that vary in amount and orientation from superficial to deep layers and from loaded to unloaded zones. A major challenge to efforts to repair cartilage by stem cell-based and other tissue engineering strategies is the inability of the resident chondrocytes to lay down new matrix with the same structural and resilient properties that it had upon its original formation. This is particularly true of the collagen network, which is susceptible to cleavage once proteoglycans are depleted. Thus, a thorough understanding of the similarities and particularly the marked differences in mechanisms of cartilage remodeling during development, osteoarthritis, and aging may lead to more effective strategies for preventing cartilage damage and promoting repair. To identify and characterize effectors or regulators of cartilage remodeling in these processes, we are using culture models of primary human and mouse chondrocytes and cell lines and mouse genetic models to manipulate gene expression programs leading to matrix remodeling and subsequent chondrocyte hypertrophic differentiation, pivotal processes which both go astray in OA disease. Matrix metalloproteinases (MMP)-13, the major type II collagen-degrading collagenase, is regulated by stress-, inflammation-, and differentiation-induced signals that not only contribute to irreversible joint damage (progression) in OA, but importantly, also to the initiation/onset phase, wherein chondrocytes in articular cartilage leave their natural growth- and differentiation-arrested state. Our work points to common mediators of these processes in human OA cartilage and in early through late stages of OA in surgical and genetic mouse models.
Collapse
Affiliation(s)
- Mary B. Goldring
- Tissue Engineering, Regeneration, and Repair Program, Research Division, The Hospital for Special Surgery, Weill Cornell Medical College, New York, NY 10021, USA,Address for correspondence: Mary B. Goldring, 535 East 70th Street, Caspary Research Building, 5th Floor, New York, NY 10021. USA,
| | - Miguel Otero
- Tissue Engineering, Regeneration, and Repair Program, Research Division, The Hospital for Special Surgery, Weill Cornell Medical College, New York, NY 10021, USA
| | - Darren A. Plumb
- Tissue Engineering, Regeneration, and Repair Program, Research Division, The Hospital for Special Surgery, Weill Cornell Medical College, New York, NY 10021, USA
| | - Cecilia Dragomir
- Tissue Engineering, Regeneration, and Repair Program, Research Division, The Hospital for Special Surgery, Weill Cornell Medical College, New York, NY 10021, USA
| | - Marta Favero
- Tissue Engineering, Regeneration, and Repair Program, Research Division, The Hospital for Special Surgery, Weill Cornell Medical College, New York, NY 10021, USA
| | - Karim El Hachem
- Tissue Engineering, Regeneration, and Repair Program, Research Division, The Hospital for Special Surgery, Weill Cornell Medical College, New York, NY 10021, USA
| | - Ko Hashimoto
- Tissue Engineering, Regeneration, and Repair Program, Research Division, The Hospital for Special Surgery, Weill Cornell Medical College, New York, NY 10021, USA
| | | | - Eleonora Olivotto
- Laboratorio di Immunoreumatologia e Rigenerazione Tissutale, Istituti Ortopedia Rizzoli, 40136 Bologna, Italy
| | - Rosa Maria Borzì
- Laboratorio di Immunoreumatologia e Rigenerazione Tissutale, Istituti Ortopedia Rizzoli, 40136 Bologna, Italy
| | - Kenneth B. Marcu
- Laboratorio di Immunoreumatologia e Rigenerazione Tissutale, Istituti Ortopedia Rizzoli, 40136 Bologna, Italy,Biochemistry and Cell Biology Dept., Stony Brook University, Stony Brook, NY, 11794-5215, USA
| | | |
Collapse
|
137
|
ANGWARAWONG T, DUBAS ST, ARKSORNNUKIT M, PAVASANT P. Differentiation of MC3T3-E1 on poly(4-styrenesulfonic acid-co-maleic acid)sodium salt-coated films. Dent Mater J 2011; 30:158-69. [DOI: 10.4012/dmj.2010-097] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
138
|
De Bari C, Kurth TB, Augello A. Mesenchymal stem cells from development to postnatal joint homeostasis, aging, and disease. ACTA ACUST UNITED AC 2010; 90:257-71. [DOI: 10.1002/bdrc.20189] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
139
|
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]
|
140
|
Cheng A, Genever PG. SOX9 determines RUNX2 transactivity by directing intracellular degradation. J Bone Miner Res 2010; 25:2680-9. [PMID: 20593410 DOI: 10.1002/jbmr.174] [Citation(s) in RCA: 104] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2010] [Revised: 05/21/2010] [Accepted: 06/22/2010] [Indexed: 12/27/2022]
Abstract
Mesenchymal stem cell differentiation is controlled by the cooperative activity of a network of signaling mechanisms. Among these, RUNX2 and SOX9 are the major transcription factors for osteogenesis and chondrogenesis, respectively. Their expression is overlapped both temporally and spatially during embryogenesis. Here we have demonstrated that RUNX2 and SOX9 physically interact in intact cells and have confirmed that SOX9 can inhibit the transactivation of RUNX2. In addition, RUNX2 exerts reciprocal inhibition on SOX9 transactivity. In analyses of the mechanism by which SOX9 regulated RUNX2 function, we demonstrated that SOX9 induced a dose-dependent degradation of RUNX2. Although RUNX2 is normally degraded by the ubiquitin-proteasome pathway, we found that SOX9-mediated degradation was proteasome-independent but phosphorylation-dependent and required the presence of the RUNX2 C-terminal domain, which contains a nuclear matrix targeting sequence (NMTS). Furthermore, SOX9 was able to decrease the level of ubiquitinated RUNX2 and direct RUNX2 to the lysosome for degradation. SOX9 also preferentially directed β-catenin, an intracellular mediator of canonical Wnt signaling, for lysosomal breakdown. Consequently, the mechanisms by which SOX9 regulates RUNX2 function may underlie broader signaling pathways that can influence osteochondrogenesis and mesenchymal fate.
Collapse
Affiliation(s)
- Aixin Cheng
- Department of Biology, University of York, York, United Kingdom.
| | | |
Collapse
|
141
|
Correa D, Hesse E, Seriwatanachai D, Kiviranta R, Saito H, Yamana K, Neff L, Atfi A, Coillard L, Sitara D, Maeda Y, Warming S, Jenkins NA, Copeland NG, Horne WC, Lanske B, Baron R. Zfp521 is a target gene and key effector of parathyroid hormone-related peptide signaling in growth plate chondrocytes. Dev Cell 2010; 19:533-46. [PMID: 20951345 DOI: 10.1016/j.devcel.2010.09.008] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2009] [Revised: 08/13/2010] [Accepted: 09/22/2010] [Indexed: 10/18/2022]
Abstract
In the growth plate, the interplay between parathyroid hormone-related peptide (PTHrP) and Indian hedgehog (Ihh) signaling tightly regulates chondrocyte proliferation and differentiation during longitudinal bone growth. We found that PTHrP increases the expression of Zfp521, a zinc finger transcriptional coregulator, in prehypertrophic chondrocytes. Mice with chondrocyte-targeted deletion of Zfp521 resembled PTHrP(-/-) and chondrocyte-specific PTHR1(-/-) mice, with decreased chondrocyte proliferation, early hypertrophic transition, and reduced growth plate thickness. Deleting Zfp521 increased expression of Runx2 and Runx2 target genes, and decreased Cyclin D1 and Bcl-2 expression while increasing Caspase-3 activation and apoptosis. Zfp521 associated with Runx2 in chondrocytes, antagonizing its activity via an HDAC4-dependent mechanism. PTHrP failed to upregulate Cyclin D1 and to antagonize Runx2, Ihh, and collagen X expression when Zfp521 was absent. Thus, Zfp521 is an important PTHrP target gene that regulates growth plate chondrocyte proliferation and differentiation.
Collapse
Affiliation(s)
- Diego Correa
- Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA 02115, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
142
|
Huang BL, Brugger SM, Lyons KM. Stage-specific control of connective tissue growth factor (CTGF/CCN2) expression in chondrocytes by Sox9 and beta-catenin. J Biol Chem 2010; 285:27702-12. [PMID: 20571031 DOI: 10.1074/jbc.m110.108498] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
CCN2/connective tissue growth factor is highly expressed in hypertrophic chondrocytes and is required for chondrogenesis. However, the transcriptional mechanisms controlling its expression in cartilage are largely unknown. The activity of the Ccn2 promoter was, therefore, investigated in osteochondro-progenitor cells and hypertrophic chondrocytes to ascertain these mechanisms. Sox9 and T-cell factor (TCF) x lymphoid enhancer factor (LEF) factors contain HMG domains and bind to related consensus sites. TCF x LEF factors are normally repressive but when bound to DNA in a complex with beta-catenin become activators of gene expression. In silico analysis of the Ccn2 proximal promoter identified multiple consensus TCF x LEF elements, one of which was also a consensus binding site for Sox9. Using luciferase reporter constructs, the TCF x LEF x Sox9 site was found to be involved in stage-specific expression of Ccn2. Luciferase, electrophoretic mobility shift assay (EMSA), and ChIP analysis revealed that Sox9 represses Ccn2 expression by binding to the consensus TCF x LEF x Sox9 site. On the other hand, the same assays showed that in hypertrophic chondrocytes, TCF x LEF x beta-catenin complexes occupy the consensus TCF x LEF x Sox9 site and activate Ccn2 expression. Furthermore, transgenic mice in which lacZ expression is driven under the control of the proximal Ccn2 promoter revealed that the proximal Ccn2 promoter responded to Wnt signaling in cartilage. Hence, we propose that differential occupancy of the TCF x LEF x Sox9 site by Sox9 versus beta-catenin restricts high levels of Ccn2 expression to hypertrophic chondrocytes.
Collapse
Affiliation(s)
- Bau-Lin Huang
- Department of Oral Biology, UCLA School of Dentistry, Los Angeles, California 90095, USA
| | | | | |
Collapse
|
143
|
Kim HJ, Im GI. The effects of ERK1/2 inhibitor on the chondrogenesis of bone marrow- and adipose tissue-derived multipotent mesenchymal stromal cells. Tissue Eng Part A 2010; 16:851-60. [PMID: 19807253 DOI: 10.1089/ten.tea.2009.0070] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
This study tested the hypothesis that mitogen-activated protein kinase inhibitors suppress hypertrophy and enhance chondrogenesis during chondrogenesis of multipotent mesenchymal stromal cells (MSCs). The effects of PD98059 (an extracellular signal-regulated kinase-1/2 inhibitor) and SB203580 (a p38 inhibitor) were tested on bone marrow-derived MSCs (BMMSCs) and adipose tissue-derived MSCs (ATMSCs). In vitro pellet cultures were carried out using 2.5 x 10(5) MSCs in a chondrogenic medium containing 5 ng/mL of transforming growth factor-beta(2) (TGF-beta(2)) for BMMSCs, and 5 ng/mL of TGF-beta(2) and 100 ng/mL of bone morphogenetic protein-7 (BMP-7) for ATMSCs. From the 14th day of culture, the pellets were additionally treated with PD98059 or SB203580. After 14 more days of in vitro culture, pellets were harvested for analysis. PD98059 increased DNA content and glycosaminoglycan amount in BMMSCs and ATMSCs, whereas SB203580 had little effect. Collagen type I (COL1A1) mRNA decreased to almost a quarter in BMMSCs treated with PD98059. The mRNA levels of collagen type II (COL2A1) and SRY (sex determining region Y)-box 9 (SOX-9) increased several fold in both cells after PD98059 treatment, whereas SB203580 had only a slight effect. The gene expression of collagen type X (COL10A1) and runt-related transcription factor 2 (Runx-2) decreased by half after PD98059 treatment in BMMSCs, and decreased further in ATMSCs. SB203580 elevated COL10A1 and Runx-2 gene expression in both cell types. Safranin-O staining and immunohistochemistry generally mirrored findings from real-time PCR except for diminished expression of type I collagen in ATMSCS, and more pronounced decrease in type X collagen and Runx-2 in BMMSCs after PD98059 treatment. Our study demonstrated that PD98059 suppressed hypertrophy and promoted chondrogenesis of MSCs, and provides a ground for using them in cartilage tissue engineering.
Collapse
Affiliation(s)
- Hye-Joung Kim
- Department of Orthopaedics, Dongguk University Ilsan Hospital, Goyang, Republic of Korea
| | | |
Collapse
|
144
|
Wang S, Qiu Y, Ma Z, Xia C, Zhu F, Zhu Z. Expression of Runx2 and type X collagen in vertebral growth plate of patients with adolescent idiopathic scoliosis. Connect Tissue Res 2010; 51:188-96. [PMID: 20073986 DOI: 10.3109/03008200903215590] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The different expression of type X collagen and Runx2 between the convex and concave side of vertebral growth plate in scoliosis may help to improve our understanding of the role that growth plate tissue play in the development or progression of idiopathic scoliosis. In this investigation, there were significant differences of the total expression of type X collagen, Runx2 protein, and Runx2 mRNA between convex side and concave side growth plates of the apex vertebrae (p < 0.05). The total expression of type X collagen in the concave side growth plates of the lower end vertebrae was higher than that in the same side growth plates of apex (p < 0.05). The total expression of Runx2 in the concave side growth plates in the upper and lower end vertebrae were higher than that in the concave side growth plates of apex (p < 0.05). The expression of type X collagen, Runx2, and Runx2 mRNA, the cell density of type X collagen and Runx2 positive chondrocytes, and histological changes between convex side and concave side of the vertebral growth plate indicated that the vertebral growth plate was affected by mechanical forces, which was a secondary change and could contribute to progression of adolescent idiopathic scoliosis.
Collapse
Affiliation(s)
- Shoufeng Wang
- Spine Surgery, Drum Tower Hospital, Nanjing University Medical School, Nanjing, China
| | | | | | | | | | | |
Collapse
|
145
|
Orfanidou T, Iliopoulos D, Malizos KN, Tsezou A. Involvement of SOX-9 and FGF-23 in RUNX-2 regulation in osteoarthritic chondrocytes. J Cell Mol Med 2010. [DOI: 10.1111/j.1582-4934.2008.00678.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
|
146
|
Fazenda C, Simões B, Kelsh RN, Cancela ML, Conceição N. Dual transcriptional regulation by runx2 of matrix Gla protein in Xenopus laevis. Gene 2010; 450:94-102. [PMID: 19896523 DOI: 10.1016/j.gene.2009.10.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2009] [Revised: 10/26/2009] [Accepted: 10/28/2009] [Indexed: 11/25/2022]
Abstract
Matrix Gla protein (MGP) is an extracellular mineral-binding protein expressed in several tissues but it only accumulates in bone and calcified cartilage under physiological conditions. Available evidence indicates that it acts as a physiological inhibitor of mineralization. Runx2 is a transcription factor essential for bone formation in mammals, affecting osteoblast and chondrocyte differentiation by regulating key genes crucial for bone and cartilage development. Being an important cartilage-associated gene, MGP is a potential target for Runx2, and thus we have investigated the possible functional interactions between them. In A6 cells, Runx2 was found to modulate MGP transcription and deletion analysis of MGP distal and proximal promoter-luciferase constructs identified cis-regulatory regions. Interestingly, we have also identified a runx2-binding site that mediates transcriptional repression of XlMGP. Mutation of this element, located between -54 and +33 bp, results in 18-fold up-regulation of transcription. Furthermore, and in addition to the previously reported Xlrunx2 types I and II, we have identified three transcripts encoding novel, truncated Xlrunx2 isoforms. Although only type I and type II could transactivate XlMGP, the truncated isoforms identified in this study, which result from alternative splicing, could be involved in negative regulation of MGP expression, as described for other RUNX2 truncated isoforms acting in other target genes. In vivo microinjection of XlMGP promoter constructs and runx2 mRNA confirmed that those promoters are targets for this transcription factor. These data also indicate that MGP is under dual regulation by runx2 through the use of various isoforms and context-dependent formation of transcriptional complexes.
Collapse
Affiliation(s)
- Cindy Fazenda
- University of Algarve, CCMAR, Campus de Gambelas, 8005-139 Faro, Portugal
| | | | | | | | | |
Collapse
|
147
|
James CG, Stanton LA, Agoston H, Ulici V, Underhill TM, Beier F. Genome-wide analyses of gene expression during mouse endochondral ossification. PLoS One 2010; 5:e8693. [PMID: 20084171 PMCID: PMC2805713 DOI: 10.1371/journal.pone.0008693] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Accepted: 12/13/2009] [Indexed: 12/24/2022] Open
Abstract
Background Endochondral ossification is a complex process involving a series of events that are initiated by the establishment of a chondrogenic template and culminate in its replacement through the coordinated activity of osteoblasts, osteoclasts and endothelial cells. Comprehensive analyses of in vivo gene expression profiles during these processes are essential to obtain a complete understanding of the regulatory mechanisms involved. Methodology/Principal Findings To address these issues, we completed a microarray screen of three zones derived from manually segmented embryonic mouse tibiae. Classification of genes differentially expressed between each respective zone, functional categorization as well as characterization of gene expression patterns, cytogenetic loci, signaling pathways and functional motifs both confirmed reported data and provided novel insights into endochondral ossification. Parallel comparisons of the microdissected tibiae data set with our previously completed micromass culture screen further corroborated the suitability of micromass cultures for modeling gene expression in chondrocyte development. The micromass culture system demonstrated striking similarities to the in vivo microdissected tibiae screen; however, the micromass system was unable to accurately distinguish gene expression differences in the hypertrophic and mineralized zones of the tibia. Conclusions/Significance These studies allow us to better understand gene expression patterns in the growth plate and endochondral bones and provide an important technical resource for comparison of gene expression in diseased or experimentally-manipulated cartilages. Ultimately, this work will help to define the genomic context in which genes are expressed in long bones and to understand physiological and pathological ossification.
Collapse
Affiliation(s)
- Claudine G. James
- CIHR Group in Skeletal Development and Remodelling, Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada
| | - Lee-Anne Stanton
- CIHR Group in Skeletal Development and Remodelling, Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada
| | - Hanga Agoston
- CIHR Group in Skeletal Development and Remodelling, Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada
| | - Veronica Ulici
- CIHR Group in Skeletal Development and Remodelling, Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada
- * E-mail: (VU); (FB)
| | - T. Michael Underhill
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Frank Beier
- CIHR Group in Skeletal Development and Remodelling, Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada
- * E-mail: (VU); (FB)
| |
Collapse
|
148
|
Tsuchimochi K, Otero M, Dragomir CL, Plumb DA, Zerbini LF, Libermann TA, Marcu KB, Komiya S, Ijiri K, Goldring MB. GADD45beta enhances Col10a1 transcription via the MTK1/MKK3/6/p38 axis and activation of C/EBPbeta-TAD4 in terminally differentiating chondrocytes. J Biol Chem 2010; 285:8395-407. [PMID: 20048163 DOI: 10.1074/jbc.m109.038638] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
GADD45beta (growth arrest- and DNA damage-inducible) interacts with upstream regulators of the JNK and p38 stress response kinases. Previously, we reported that the hypertrophic zone of the Gadd45beta(-/-) mouse embryonic growth plate is compressed, and expression of type X collagen (Col10a1) and matrix metalloproteinase 13 (Mmp13) genes is decreased. Herein, we report that GADD45beta enhances activity of the proximal Col10a1 promoter, which contains evolutionarily conserved AP-1, cAMP-response element, and C/EBP half-sites, in synergism with C/EBP family members, whereas the MMP13 promoter responds to GADD45beta together with AP-1, ATF, or C/EBP family members. C/EBPbeta expression also predominantly co-localizes with GADD45beta in the embryonic growth plate. Moreover, GADD45beta enhances C/EBPbeta activation via MTK1, MKK3, and MKK6, and dominant-negative p38alphaapf, but not JNKapf, disrupts the combined trans-activating effect of GADD45beta and C/EBPbeta on the Col10a1 promoter. Importantly, GADD45beta knockdown prevents p38 phosphorylation while decreasing Col10a1 mRNA levels but does not affect C/EBPbeta binding to the Col10a1 promoter in vivo, indicating that GADD45beta influences the transactivation function of DNA-bound C/EBPbeta. In support of this conclusion, we show that the evolutionarily conserved TAD4 domain of C/EBPbeta is the target of the GADD45beta-dependent signaling. Collectively, we have uncovered a novel molecular mechanism linking GADD45beta via the MTK1/MKK3/6/p38 axis to C/EBPbeta-TAD4 activation of Col10a1 transcription in terminally differentiating chondrocytes.
Collapse
Affiliation(s)
- Kaneyuki Tsuchimochi
- Laboratory for Cartilage Biology, Research Division, The Hospital for Special Surgery, Weill Cornell Medical College, New York, New York 10021, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
149
|
|
150
|
Nakatani S, Mano H, Sampei C, Shimizu J, Wada M. Chondroprotective effect of the bioactive peptide prolyl-hydroxyproline in mouse articular cartilage in vitro and in vivo. Osteoarthritis Cartilage 2009; 17:1620-7. [PMID: 19615963 DOI: 10.1016/j.joca.2009.07.001] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2008] [Revised: 06/19/2009] [Accepted: 07/02/2009] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To investigate the direct effect of prolyl-hydroxyproline (Pro-Hyp) on chondrocytes under in vivo and in vitro conditions in an attempt to identify Pro-Hyp as the bioactive peptide in collagen hydrolysate (CH). METHODS The in vivo effects of CH and Pro-Hyp intake on articular cartilage were studied by microscopic examination of sections of dissected articular cartilage from treated C57BL/6J mice. In this study, mice that were fed diets containing excess phosphorus were used as an in vivo model. This mouse line showed loss of chondrocytes and reduced thickness of articular cartilage, with abnormality of the subchondral bone. The in vitro effects of CH, Pro-Hyp, amino acids and other peptides on proliferation, differentiation, glycosaminoglycan content and mineralization of chondrocytes were determined by MTT activity and staining with alkaline phosphatase, alcian blue and alizarin red. Expression of chondrogenesis-specific genes in ATDC5 cells was determined by semiquantitative Reverse Transcription Polymerase Chain Reaction (RT-PCR). RESULTS In vivo, CH and Pro-Hyp inhibited the loss of chondrocytes and thinning of the articular cartilage layer caused by phosphorus-induced degradation. In the in vitro study, CH and Pro-Hyp did not affect chondrocyte proliferation but inhibited their differentiation into mineralized chondrocytes. A combination of amino acids such as proline, hydroxyproline and prolyl-hydroxyprolyl-glycine did not affect chondrocyte proliferation or differentiation. Moreover, CH and Pro-Hyp caused two and threefold increases, respectively, in the staining area of glycosaminoglycan in the extracellular matrix of ATDC5 cells. RT-PCR indicated that Pro-Hyp increased the aggrecan mRNA level approximately twofold and decreased the Runx1 and osteocalcin mRNA levels by two-thirds and one-tenth, respectively. CONCLUSION Pro-Hyp is the first bioactive edible peptide derived from CH to be shown to affect chondrocyte differentiation under pathological conditions.
Collapse
Affiliation(s)
- S Nakatani
- Department of Food Functional Science, Graduate School of Pharmacology, Josai University, Keyakidai 1-1, Sakado, Saitama 3500295, Japan
| | | | | | | | | |
Collapse
|