151
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Rastogi B, Raut SK, Panda NK, Rattan V, Radotra BD, Khullar M. Overexpression of HDAC9 promotes oral squamous cell carcinoma growth, regulates cell cycle progression, and inhibits apoptosis. Mol Cell Biochem 2016; 415:183-96. [PMID: 26992905 DOI: 10.1007/s11010-016-2690-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 03/12/2016] [Indexed: 12/18/2022]
Abstract
Histone deacetylases (HDACs) are a family of deacetylase enzymes that regulate the acetylation state of histones and a variety of other non-histone proteins including key oncogenic and tumor suppressor proteins, which modulates chromatin conformation, leading to regulation of gene expression. HDACs has been grouped into classes I-IV and histone deacetylase 9 (HDAC9) belongs to class IIa which exhibits tissue-specific expression. Recent reports have demonstrated both pro-oncogenic and tumor suppressive role for HDAC9 in different cancers; however, its role in OSCC remains elusive. Here, we investigated the role of HDAC9 in pathogenesis of oral squamous cell carcinoma (OSCC). Our data showed significantly increased mRNA and protein expression of HDAC9 in clinical OSCC samples and UPCI-SCC-116 cells as compared to normal counterpart. Kaplan-Meier analysis showed that the patients with high-level of HDAC9 expression had significantly reduced overall survival than those with low-level of HDAC9 expression (p = 0.034). Knockdown of HDAC9 using siRNA interference suppressed cell proliferation, increased apoptosis, and induced G0/G1 cell cycle arrest in UPCI-SCC-116 cells. Immunofluorescence analysis showed increased nuclear localization of HDAC9 in frozen OSCC sections, and indicative of active HDAC9 that may transcriptionally repress its downstream target genes. Subsequent investigation revealed that overexpression of HDAC9 contributes to OSCC carcinogenesis via targeting a transcription factor, MEF2D, and NR4A1/Nur77, a pro-apoptotic MEF2 target.
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Affiliation(s)
- Bhawna Rastogi
- Department of Otolaryngology and Head and Neck Surgery, Post Graduate Institute of Medical Education and Research, Chandigarh, 160012, India
| | - Satish K Raut
- Department of Experimental Medicine and Biotechnology, Post Graduate Institute of Medical Education and Research, Chandigarh, 160012, India
| | - Naresh K Panda
- Department of Otolaryngology and Head and Neck Surgery, Post Graduate Institute of Medical Education and Research, Chandigarh, 160012, India
| | - Vidya Rattan
- Department of Oral Health Sciences Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, 160012, India
| | - Bishan D Radotra
- Department of Histopathology, Post Graduate Institute of Medical Education and Research, Chandigarh, 160012, India
| | - Madhu Khullar
- Department of Experimental Medicine and Biotechnology, Post Graduate Institute of Medical Education and Research, Chandigarh, 160012, India.
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152
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Dou C, Li N, Ding N, Liu C, Yang X, Kang F, Cao Z, Quan H, Hou T, Xu J, Dong S. HDAC2 regulates FoxO1 during RANKL-induced osteoclastogenesis. Am J Physiol Cell Physiol 2016; 310:C780-7. [PMID: 26962001 DOI: 10.1152/ajpcell.00351.2015] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 02/23/2016] [Indexed: 11/22/2022]
Abstract
The bone-resorbing osteoclast (OC) is essential for bone homeostasis, yet deregulation of OCs contributes to diseases such as osteoporosis, osteopetrosis, and rheumatoid arthritis. Here we show that histone deacetylase 2 (HDAC2) is a key positive regulator during receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclastogenesis and bone resorption. Bone marrow macrophages (BMMs) showed increased HDAC2 expression during osteoclastogenesis. HDAC2 overexpression enhanced, whereas HDAC2 deletion suppressed osteoclastogenesis and bone resorption using lentivirus infection. Mechanistically, upon RANKL activation, HDAC2 activated Akt; Akt directly phosphorylates and abrogates Forkhead box protein O1 (FoxO1), which is a negative regulator during osteoclastogenesis through reducing reactive oxygen species. HDAC2 deletion in BMMs resulted in decreased Akt activation and increased FoxO1 activity during osteoclastogenesis. In conclusion, HDAC2 activates Akt thus suppresses FoxO1 transcription results in enhanced osteoclastogenesis. Our data imply the potential value of HDAC2 as a new target in regulating osteoclast differentiation and function.
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Affiliation(s)
- Ce Dou
- Department of Biomedical Materials Science, School of Biomedical Engineering, Third Military Medical University, Chongqing, China; and Department of Orthopedics, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Nan Li
- Department of Biomedical Materials Science, School of Biomedical Engineering, Third Military Medical University, Chongqing, China; and
| | - Ning Ding
- Department of Biomedical Materials Science, School of Biomedical Engineering, Third Military Medical University, Chongqing, China; and
| | - Chuan Liu
- Department of Biomedical Materials Science, School of Biomedical Engineering, Third Military Medical University, Chongqing, China; and
| | - Xiaochao Yang
- Department of Biomedical Materials Science, School of Biomedical Engineering, Third Military Medical University, Chongqing, China; and
| | - Fei Kang
- Department of Biomedical Materials Science, School of Biomedical Engineering, Third Military Medical University, Chongqing, China; and
| | - Zhen Cao
- Department of Biomedical Materials Science, School of Biomedical Engineering, Third Military Medical University, Chongqing, China; and
| | - Hongyu Quan
- Department of Biomedical Materials Science, School of Biomedical Engineering, Third Military Medical University, Chongqing, China; and
| | - Tianyong Hou
- Department of Orthopedics, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Jianzhong Xu
- Department of Orthopedics, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Shiwu Dong
- Department of Biomedical Materials Science, School of Biomedical Engineering, Third Military Medical University, Chongqing, China; and
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153
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Bomer N, Cornelis FMF, Ramos YFM, den Hollander W, Storms L, van der Breggen R, Lakenberg N, Slagboom PE, Meulenbelt I, Lories RJL. The effect of forced exercise on knee joints in Dio2(-/-) mice: type II iodothyronine deiodinase-deficient mice are less prone to develop OA-like cartilage damage upon excessive mechanical stress. Ann Rheum Dis 2016; 75:571-7. [PMID: 25550340 DOI: 10.1136/annrheumdis-2014-206608] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 12/07/2014] [Indexed: 01/10/2023]
Abstract
OBJECTIVE To further explore deiodinase iodothyronine type 2 (DIO2) as a therapeutic target in osteoarthritis (OA) by studying the effects of forced mechanical loading on in vivo joint cartilage tissue homeostasis and the modulating effect herein of Dio2 deficiency. METHODS Wild-type and C57BL/6-Dio2(-/-) -mice were subjected to a forced running regime for 1 h per day for 3 weeks. Severity of OA was assessed by histological scoring for cartilage damage and synovitis. Genome-wide gene expression was determined in knee cartilage by microarray analysis (Illumina MouseWG-6 v2). STRING-db analyses were applied to determine enrichment for specific pathways and to visualise protein-protein interactions. RESULTS In total, 158 probes representing 147 unique genes showed significantly differential expression with a fold-change ≥1.5 upon forced exercise. Among these are genes known for their association with OA (eg, Mef2c, Egfr, Ctgf, Prg4 and Ctnnb1), supporting the use of forced running as an OA model in mice. Dio2-deficient mice showed significantly less cartilage damage and signs of synovitis. Gene expression response upon exercise between wild-type and knockout mice was significantly different for 29 genes. CONCLUSIONS Mice subjected to a running regime have significant increased cartilage damage and synovitis scores. Lack of Dio2 protected against cartilage damage in this model and was reflected in a specific gene expression profile, and either mark a favourable effect in the Dio2 knockout (eg, Gnas) or an unfavourable effect in wild-type cartilage homeostasis (eg, Hmbg2 and Calr). These data further support DIO2 activity as a therapeutic target in OA.
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MESH Headings
- Animals
- Cartilage, Articular/metabolism
- Cartilage, Articular/pathology
- Gene Expression Profiling
- Iodide Peroxidase/genetics
- Knee Joint/metabolism
- Knee Joint/pathology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Oligonucleotide Array Sequence Analysis
- Osteoarthritis, Knee/genetics
- Osteoarthritis, Knee/metabolism
- Osteoarthritis, Knee/pathology
- Physical Conditioning, Animal
- RNA, Messenger/metabolism
- Real-Time Polymerase Chain Reaction
- Stress, Mechanical
- Iodothyronine Deiodinase Type II
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Affiliation(s)
- Nils Bomer
- Department of Molecular Epidemiology, LUMC, Leiden, The Netherlands Integrated Research of Developmental Determinants of Ageing and Longevity (IDEAL), Leiden, Netherlands
| | - Frederique M F Cornelis
- Laboratory of Tissue Homeostasis and Disease, Skeletal Biology and Engineering Research Centre, KU Leuven, Leuven, Belgium
| | | | | | - Lies Storms
- Laboratory of Tissue Homeostasis and Disease, Skeletal Biology and Engineering Research Centre, KU Leuven, Leuven, Belgium
| | | | - Nico Lakenberg
- Department of Molecular Epidemiology, LUMC, Leiden, The Netherlands
| | - P Eline Slagboom
- Department of Molecular Epidemiology, LUMC, Leiden, The Netherlands Integrated Research of Developmental Determinants of Ageing and Longevity (IDEAL), Leiden, Netherlands The Netherlands Genomics Initiative, sponsored by the NCHA, Leiden-Rotterdam, The Netherlands
| | - Ingrid Meulenbelt
- Department of Molecular Epidemiology, LUMC, Leiden, The Netherlands The Netherlands Genomics Initiative, sponsored by the NCHA, Leiden-Rotterdam, The Netherlands
| | - Rik J L Lories
- Laboratory of Tissue Homeostasis and Disease, Skeletal Biology and Engineering Research Centre, KU Leuven, Leuven, Belgium Division of Rheumatology, University Hospitals Leuven, Leuven, Belgium
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154
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Cao XK, Zhan ZY, Huang YZ, Lan XY, Lei CZ, Qi XL, Chen H. Variants and haplotypes within MEF2C gene influence stature of chinese native cattle including body dimensions and weight. Livest Sci 2016. [DOI: 10.1016/j.livsci.2016.01.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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155
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Di Giorgio E, Brancolini C. Regulation of class IIa HDAC activities: it is not only matter of subcellular localization. Epigenomics 2016; 8:251-69. [DOI: 10.2217/epi.15.106] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
In response to environmental cues, enzymes that influence the functions of proteins, through reversible post-translational modifications supervise the coordination of cell behavior like orchestral conductors. Class IIa histone deacetylases (HDACs) belong to this category. Even though in vertebrates these deacetylases have discarded the core enzymatic activity, class IIa HDACs can assemble into multiprotein complexes devoted to transcriptional reprogramming, including but not limited to epigenetic changes. Class IIa HDACs are subjected to variegated and interconnected layers of regulation, which reflect the wide range of biological responses under the scrutiny of this gene family. Here, we discuss about the key mechanisms that fine tune class IIa HDACs activities.
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Affiliation(s)
- Eros Di Giorgio
- Department of Medical & Biological Sciences, Università degli Studi di Udine., P.le Kolbe 4 - 33100 Udine, Italy
| | - Claudio Brancolini
- Department of Medical & Biological Sciences, Università degli Studi di Udine., P.le Kolbe 4 - 33100 Udine, Italy
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156
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Mafi Golchin M, Heidari L, Ghaderian SMH, Akhavan-Niaki H. Osteoporosis: A Silent Disease with Complex Genetic Contribution. J Genet Genomics 2016; 43:49-61. [PMID: 26924688 DOI: 10.1016/j.jgg.2015.12.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 10/30/2015] [Accepted: 12/26/2015] [Indexed: 12/17/2022]
Abstract
Osteoporosis is the most common multifactorial metabolic bone disorder worldwide with a strong genetic component. In this review, the evidence for a genetic contribution to osteoporosis and related phenotypes is summarized alongside with methods used to identify osteoporosis susceptibility genes. The key biological pathways involved in the skeleton and bone development are discussed with a particular focus on master genes clustered in these pathways and their mode of action. Furthermore, the most studied single nucleotide polymorphisms (SNPs) analyzed for their importance as genetic markers of the disease are presented. New data generated by next-generation sequencing in conjunction with extensive meta-analyses should contribute to a better understanding of the genetic basis of osteoporosis and related phenotype variability. These data could be ultimately used for identifying at-risk patients for disease prevention by both controlling environmental factors and providing possible therapeutic targets.
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Affiliation(s)
- Maryam Mafi Golchin
- Department of Genetics, Faculty of Medicine, Babol University of Medical Sciences, Babol 4717647745, Iran
| | - Laleh Heidari
- Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical Sciences & Health Services, Tehran 1985717443, Iran
| | - Seyyed Mohammad Hossein Ghaderian
- Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical Sciences & Health Services, Tehran 1985717443, Iran
| | - Haleh Akhavan-Niaki
- Department of Genetics, Faculty of Medicine, Babol University of Medical Sciences, Babol 4717647745, Iran.
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157
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Chen Y, Bianchessi M, Pondenis H, Stewart M. Phenotypic characterization of equine synovial fluid-derived chondroprogenitor cells. ACTA ACUST UNITED AC 2016. [DOI: 10.7243/2054-717x-3-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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158
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Effect of Fibroblast Growth Factor 2 on Equine Synovial Fluid Chondroprogenitor Expansion and Chondrogenesis. Stem Cells Int 2015; 2016:9364974. [PMID: 26839571 PMCID: PMC4709790 DOI: 10.1155/2016/9364974] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2015] [Revised: 09/29/2015] [Accepted: 09/30/2015] [Indexed: 01/22/2023] Open
Abstract
Mesenchymal stem cells have been identified in the synovial fluid of several species. This study was conducted to characterize chondroprogenitor (CP) cells in equine synovial fluid (SF) and to determine the effect of fibroblast growth factor 2 (FGF-2) on SF-CP monolayer proliferation and subsequent chondrogenesis. We hypothesized that FGF-2 would stimulate SF-CP proliferation and postexpansion chondrogenesis. SF aspirates were collected from adult equine joints. Colony-forming unit (CFU) assays were performed during primary cultures. At first passage, SF-cells were seeded at low density, with or without FGF-2. Following monolayer expansion and serial immunophenotyping, cells were transferred to chondrogenic pellet cultures. Pellets were analyzed for chondrogenic mRNA expression and cartilage matrix secretion. There was a mean of 59.2 CFU/mL of SF. FGF-2 increased the number of population doublings during two monolayer passages and halved the population doubling times. FGF-2 did not alter the immunophenotype of SF-CPs during monolayer expansion, nor did FGF-2 compromise chondrogenesis. Hypertrophic phenotypic markers were not expressed in control or FGF-2 groups. FGF-2 did prevent the development of a “fibroblastic” cell layer around pellet periphery. FGF-2 significantly accelerates in vitro SF-CP expansion, the major hurdle to clinical application of this cell population, without detrimentally affecting subsequent chondrogenic capacity.
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159
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Fazenda C, Conceição N, Cancela M. Transcription factors from Sox family regulate expression of zebrafish Gla-rich protein 2 gene. Gene 2015; 572:57-62. [DOI: 10.1016/j.gene.2015.06.079] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 06/26/2015] [Accepted: 06/29/2015] [Indexed: 12/11/2022]
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160
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Peck SH, O'Donnell PJM, Kang JL, Malhotra NR, Dodge GR, Pacifici M, Shore EM, Haskins ME, Smith LJ. Delayed hypertrophic differentiation of epiphyseal chondrocytes contributes to failed secondary ossification in mucopolysaccharidosis VII dogs. Mol Genet Metab 2015; 116:195-203. [PMID: 26422116 PMCID: PMC4641049 DOI: 10.1016/j.ymgme.2015.09.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 09/22/2015] [Accepted: 09/23/2015] [Indexed: 10/23/2022]
Abstract
Mucopolysaccharidosis (MPS) VII is a lysosomal storage disorder characterized by deficient β-glucuronidase activity, which leads to the accumulation of incompletely degraded glycosaminoglycans (GAGs). MPS VII patients present with severe skeletal abnormalities, which are particularly prevalent in the spine. Incomplete cartilage-to-bone conversion in MPS VII vertebrae during postnatal development is associated with progressive spinal deformity and spinal cord compression. The objectives of this study were to determine the earliest postnatal developmental stage at which vertebral bone disease manifests in MPS VII and to identify the underlying cellular basis of impaired cartilage-to-bone conversion, using the naturally-occurring canine model. Control and MPS VII dogs were euthanized at 9 and 14 days-of-age, and vertebral secondary ossification centers analyzed using micro-computed tomography, histology, qPCR, and protein immunoblotting. Imaging studies and mRNA analysis of bone formation markers established that secondary ossification commences between 9 and 14 days in control animals, but not in MPS VII animals. mRNA analysis of differentiation markers revealed that MPS VII epiphyseal chondrocytes are unable to successfully transition from proliferation to hypertrophy during this critical developmental window. Immunoblotting demonstrated abnormal persistence of Sox9 protein in MPS VII cells between 9 and 14 days-of-age, and biochemical assays revealed abnormally high intra and extracellular GAG content in MPS VII epiphyseal cartilage at as early as 9 days-of-age. In contrast, assessment of vertebral growth plates and primary ossification centers revealed no significant abnormalities at either age. The results of this study establish that failed vertebral bone formation in MPS VII can be traced to the failure of epiphyseal chondrocytes to undergo hypertrophic differentiation at the appropriate developmental stage, and suggest that aberrant processing of Sox9 protein may contribute to this cellular dysfunction. These results also highlight the importance of early diagnosis and therapeutic intervention to prevent the progression of debilitating skeletal disease in MPS patients.
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Affiliation(s)
- Sun H Peck
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Philip J M O'Donnell
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Jennifer L Kang
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Neil R Malhotra
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - George R Dodge
- Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Maurizio Pacifici
- Division of Orthopedic Surgery, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Eileen M Shore
- Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Mark E Haskins
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Lachlan J Smith
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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161
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162
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Autism-Associated Chromatin Regulator Brg1/SmarcA4 Is Required for Synapse Development and Myocyte Enhancer Factor 2-Mediated Synapse Remodeling. Mol Cell Biol 2015; 36:70-83. [PMID: 26459759 DOI: 10.1128/mcb.00534-15] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Accepted: 10/05/2015] [Indexed: 11/20/2022] Open
Abstract
Synapse development requires normal neuronal activities and the precise expression of synapse-related genes. Dysregulation of synaptic genes results in neurological diseases such as autism spectrum disorders (ASD). Mutations in genes encoding chromatin-remodeling factor Brg1/SmarcA4 and its associated proteins are the genetic causes of several developmental diseases with neurological defects and autistic symptoms. Recent large-scale genomic studies predicted Brg1/SmarcA4 as one of the key nodes of the ASD gene network. We report that Brg1 deletion in early postnatal hippocampal neurons led to reduced dendritic spine density and maturation and impaired synapse activities. In developing mice, neuronal Brg1 deletion caused severe neurological defects. Gene expression analyses indicated that Brg1 regulates a significant number of genes known to be involved in synapse function and implicated in ASD. We found that Brg1 is required for dendritic spine/synapse elimination mediated by the ASD-associated transcription factor myocyte enhancer factor 2 (MEF2) and that Brg1 regulates the activity-induced expression of a specific subset of genes that overlap significantly with the targets of MEF2. Our analyses showed that Brg1 interacts with MEF2 and that MEF2 is required for Brg1 recruitment to target genes in response to neuron activation. Thus, Brg1 plays important roles in both synapse development/maturation and MEF2-mediated synapse remodeling. Our study reveals specific functions of the epigenetic regulator Brg1 in synapse development and provides insights into its role in neurological diseases such as ASD.
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163
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Bradley EW, Carpio LR, van Wijnen AJ, McGee-Lawrence ME, Westendorf JJ. Histone Deacetylases in Bone Development and Skeletal Disorders. Physiol Rev 2015; 95:1359-81. [PMID: 26378079 PMCID: PMC4600951 DOI: 10.1152/physrev.00004.2015] [Citation(s) in RCA: 109] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Histone deacetylases (Hdacs) are conserved enzymes that remove acetyl groups from lysine side chains in histones and other proteins. Eleven of the 18 Hdacs encoded by the human and mouse genomes depend on Zn(2+) for enzymatic activity, while the other 7, the sirtuins (Sirts), require NAD2(+). Collectively, Hdacs and Sirts regulate numerous cellular and mitochondrial processes including gene transcription, DNA repair, protein stability, cytoskeletal dynamics, and signaling pathways to affect both development and aging. Of clinical relevance, Hdacs inhibitors are United States Food and Drug Administration-approved cancer therapeutics and are candidate therapies for other common diseases including arthritis, diabetes, epilepsy, heart disease, HIV infection, neurodegeneration, and numerous aging-related disorders. Hdacs and Sirts influence skeletal development, maintenance of mineral density and bone strength by affecting intramembranous and endochondral ossification, as well as bone resorption. With few exceptions, inhibition of Hdac or Sirt activity though either loss-of-function mutations or prolonged chemical inhibition has negative and/or toxic effects on skeletal development and bone mineral density. Specifically, Hdac/Sirt suppression causes abnormalities in physiological development such as craniofacial dimorphisms, short stature, and bone fragility that are associated with several human syndromes or diseases. In contrast, activation of Sirts may protect the skeleton from aging and immobilization-related bone loss. This knowledge may prolong healthspan and prevent adverse events caused by epigenetic therapies that are entering the clinical realm at an unprecedented rate. In this review, we summarize the general properties of Hdacs/Sirts and the research that has revealed their essential functions in bone forming cells (e.g., osteoblasts and chondrocytes) and bone resorbing osteoclasts. Finally, we offer predictions on future research in this area and the utility of this knowledge for orthopedic applications and bone tissue engineering.
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Affiliation(s)
- Elizabeth W Bradley
- Mayo Clinic, Departments of Orthopedic Surgery and of Biochemistry and Molecular Biology, and Mayo Graduate School, Rochester, Minnesota; and Georgia Regents University, Department of Cellular Biology and Anatomy, Augusta, Georgia
| | - Lomeli R Carpio
- Mayo Clinic, Departments of Orthopedic Surgery and of Biochemistry and Molecular Biology, and Mayo Graduate School, Rochester, Minnesota; and Georgia Regents University, Department of Cellular Biology and Anatomy, Augusta, Georgia
| | - Andre J van Wijnen
- Mayo Clinic, Departments of Orthopedic Surgery and of Biochemistry and Molecular Biology, and Mayo Graduate School, Rochester, Minnesota; and Georgia Regents University, Department of Cellular Biology and Anatomy, Augusta, Georgia
| | - Meghan E McGee-Lawrence
- Mayo Clinic, Departments of Orthopedic Surgery and of Biochemistry and Molecular Biology, and Mayo Graduate School, Rochester, Minnesota; and Georgia Regents University, Department of Cellular Biology and Anatomy, Augusta, Georgia
| | - Jennifer J Westendorf
- Mayo Clinic, Departments of Orthopedic Surgery and of Biochemistry and Molecular Biology, and Mayo Graduate School, Rochester, Minnesota; and Georgia Regents University, Department of Cellular Biology and Anatomy, Augusta, Georgia
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164
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Clocchiatti A, Di Giorgio E, Viviani G, Streuli C, Sgorbissa A, Picco R, Cutano V, Brancolini C. The MEF2-HDAC axis controls proliferation of mammary epithelial cells and acini formation in vitro. J Cell Sci 2015; 128:3961-76. [PMID: 26403201 DOI: 10.1242/jcs.170357] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 09/15/2015] [Indexed: 12/31/2022] Open
Abstract
The myocyte enhancer factor 2 and histone deacetylase (MEF2-HDAC) axis is a master regulator of different developmental programs and adaptive responses in adults. In this paper, we have investigated the contribution of the axis to the regulation of epithelial morphogenesis, using 3D organotypic cultures of MCF10A cells as a model. We have demonstrated that MEF2 transcriptional activity is upregulated during acini formation, which coincides with exit from the proliferative phase. Upregulation of the transcription of MEF2 proteins is coupled to downregulation of HDAC7, which occurs independently from changes in mRNA levels, and proteasome- or autophagy-mediated degradation. During acini formation, the MEF2-HDAC axis contributes to the promotion of cell cycle exit, through the engagement of the CDK inhibitor CDKN1A. Only in proliferating cells can HDAC7 bind to the first intron of the CDKN1A gene, a region characterized by epigenetic markers of active promoters and enhancers. In cells transformed by the oncogene HER2 (ERBB2), acini morphogenesis is altered, MEF2 transcription is repressed and HDAC7 is continuously expressed. Importantly, reactivation of MEF2 transcriptional activity in these cells, through the use of a HER2 inhibitor or by enhancing MEF2 function, corrected the proliferative defect and re-established normal acini morphogenesis.
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Affiliation(s)
- Andrea Clocchiatti
- Dipartiment of Medical and Biological Sciences, Università degli Studi di Udine, P.le Kolbe 4, Udine 33100, Italy
| | - Eros Di Giorgio
- Dipartiment of Medical and Biological Sciences, Università degli Studi di Udine, P.le Kolbe 4, Udine 33100, Italy
| | - Giulia Viviani
- Dipartiment of Medical and Biological Sciences, Università degli Studi di Udine, P.le Kolbe 4, Udine 33100, Italy
| | - Charles Streuli
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester M13 9PT, UK
| | - Andrea Sgorbissa
- Dipartiment of Medical and Biological Sciences, Università degli Studi di Udine, P.le Kolbe 4, Udine 33100, Italy
| | - Raffaella Picco
- Dipartiment of Medical and Biological Sciences, Università degli Studi di Udine, P.le Kolbe 4, Udine 33100, Italy
| | - Valentina Cutano
- Dipartiment of Medical and Biological Sciences, Università degli Studi di Udine, P.le Kolbe 4, Udine 33100, Italy
| | - Claudio Brancolini
- Dipartiment of Medical and Biological Sciences, Università degli Studi di Udine, P.le Kolbe 4, Udine 33100, Italy
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165
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Kato K, Bhattaram P, Penzo-Méndez A, Gadi A, Lefebvre V. SOXC Transcription Factors Induce Cartilage Growth Plate Formation in Mouse Embryos by Promoting Noncanonical WNT Signaling. J Bone Miner Res 2015; 30:1560-71. [PMID: 25761772 PMCID: PMC4540656 DOI: 10.1002/jbmr.2504] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 03/03/2015] [Accepted: 03/06/2015] [Indexed: 01/29/2023]
Abstract
Growth plates are specialized cartilage structures that ensure the elongation of most skeletal primordia during vertebrate development. They are made by chondrocytes that proliferate in longitudinal columns and then progress in a staggered manner towards prehypertrophic, hypertrophic and terminal maturation. Complex molecular networks control the formation and activity of growth plates, but remain incompletely understood. We investigated here the importance of the SoxC genes, which encode the SOX4, SOX11 and SOX12 transcription factors, in growth plates. We show that the three genes are expressed robustly in perichondrocytes and weakly in growth plate chondrocytes. SoxC(Prx1Cre) mice, which deleted SoxC genes in limb bud skeletogenic mesenchyme, were born with tiny appendicular cartilage primordia because of failure to form growth plates. In contrast, SoxC(Col2Cre) and SoxC(ATC) mice, which deleted SoxC genes primarily in chondrocytes, were born with mild dwarfism and fair growth plates. Chondrocytes in the latter mutants matured normally, but formed irregular columns, proliferated slowly and died ectopically. Asymmetric distribution of VANGL2 was defective in both SoxC(Prx1Cre) and SoxC(ATC) chondrocytes, indicating impairment of planar cell polarity, a noncanonical WNT signaling pathway that controls growth plate chondrocyte alignment, proliferation and survival. Accordingly, SoxC genes were necessary in perichondrocytes for expression of Wnt5a, which encodes a noncanonical WNT ligand required for growth plate formation, and in chondrocytes and perichondrocytes for expression of Fzd3 and Csnk1e, which encode a WNT receptor and casein kinase-1 subunit mediating planar cell polarity, respectively. Reflecting the differential strengths of the SOXC protein transactivation domains, SOX11 was more powerful than SOX4, and SOX12 interfered with the activity of SOX4 and SOX11. Altogether, these findings provide novel insights into the molecular regulation of skeletal growth by proposing that SOXC proteins act cell- and non-cell-autonomously in perichondrocytes and chondrocytes to establish noncanonical WNT signaling crosstalk essential for growth plate induction and control.
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Affiliation(s)
- Kenji Kato
- Department of Cellular & Molecular Medicine, Orthopaedic and Rheumatologic Research Center, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA
| | - Pallavi Bhattaram
- Department of Cellular & Molecular Medicine, Orthopaedic and Rheumatologic Research Center, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA
| | - Alfredo Penzo-Méndez
- Department of Cellular & Molecular Medicine, Orthopaedic and Rheumatologic Research Center, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA
| | - Abhilash Gadi
- Department of Cellular & Molecular Medicine, Orthopaedic and Rheumatologic Research Center, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA
| | - Véronique Lefebvre
- Department of Cellular & Molecular Medicine, Orthopaedic and Rheumatologic Research Center, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA
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166
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Latchney SE, Jiang Y, Petrik DP, Eisch AJ, Hsieh J. Inducible knockout of Mef2a, -c, and -d from nestin-expressing stem/progenitor cells and their progeny unexpectedly uncouples neurogenesis and dendritogenesis in vivo. FASEB J 2015; 29:5059-71. [PMID: 26286136 DOI: 10.1096/fj.15-275651] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Accepted: 08/13/2015] [Indexed: 12/11/2022]
Abstract
Myocyte enhancer factor (Mef)-2 transcription factors are implicated in activity-dependent neuronal processes during development, but the role of MEF2 in neural stem/progenitor cells (NSPCs) in the adult brain is unknown. We used a transgenic mouse in which Mef2a, -c, and -d were inducibly deleted in adult nestin-expressing NSPCs and their progeny. Recombined cells in the hippocampal granule cell layer were visualized and quantified by yellow fluorescent protein (YFP) expression. In control mice, postmitotic neurons expressed Mef2a, -c, and -d, whereas type 1 stem cells and proliferating progenitors did not. Based on this expression, we hypothesized that Mef2a, -c, and -d deletion in adult nestin-expressing NSPCs and their progeny would result in fewer mature neurons. Control mice revealed an increase in YFP(+) neurons and dendrite formation over time. Contrary to our hypothesis, inducible Mef2 KO mice also displayed an increase in YFP(+) neurons over time-but with significantly stunted dendrites-suggesting an uncoupling of neuron survival and dendritogenesis. We also found non-cell-autonomous effects after Mef2a, -c, and -d deletion. These in vivo findings indicate a surprising functional role for Mef2a, -c, and -d in cell- and non-cell-autonomous control of adult hippocampal neurogenesis that is distinct from its role during development.
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Affiliation(s)
- Sarah E Latchney
- *Department of Psychiatry and Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Yindi Jiang
- *Department of Psychiatry and Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - David P Petrik
- *Department of Psychiatry and Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Amelia J Eisch
- *Department of Psychiatry and Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Jenny Hsieh
- *Department of Psychiatry and Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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167
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Guo X, Wang SB, Xu H, Ribic A, Mohns EJ, Zhou Y, Zhu X, Biederer T, Crair MC, Chen B. A short N-terminal domain of HDAC4 preserves photoreceptors and restores visual function in retinitis pigmentosa. Nat Commun 2015; 6:8005. [PMID: 26272629 PMCID: PMC4538705 DOI: 10.1038/ncomms9005] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 07/07/2015] [Indexed: 11/09/2022] Open
Abstract
Retinitis pigmentosa is a leading cause of inherited blindness, with no effective treatment currently available. Mutations primarily in genes expressed in rod photoreceptors lead to early rod death, followed by a slower phase of cone photoreceptor death. Rd1 mice provide an invaluable animal model to evaluate therapies for the disease. We previously reported that overexpression of histone deacetylase 4 (HDAC4) prolongs rod survival in rd1 mice. Here we report a key role of a short N-terminal domain of HDAC4 in photoreceptor protection. Expression of this domain suppresses multiple cell death pathways in photoreceptor degeneration, and preserves even more rd1 rods than the full-length HDAC4 protein. Expression of a short N-terminal domain of HDAC4 as a transgene in mice carrying the rd1 mutation also prolongs the survival of cone photoreceptors, and partially restores visual function. Our results may facilitate the design of a small protein therapy for some forms of retinitis pigmentosa.
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Affiliation(s)
- Xinzheng Guo
- Department of Ophthalmology and Visual Science, Yale University School of Medicine, 300 George Street, Suite 8100, New Haven, Connecticut 06511, USA
| | - Shao-Bin Wang
- Department of Ophthalmology and Visual Science, Yale University School of Medicine, 300 George Street, Suite 8100, New Haven, Connecticut 06511, USA
| | - Hongping Xu
- Department of Neurobiology, Yale University School of Medicine, 333 Cedar Street, SHM B301, New Haven, Connecticut 06510, USA
| | - Adema Ribic
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
| | - Ethan J Mohns
- Department of Neurobiology, Yale University School of Medicine, 333 Cedar Street, SHM B301, New Haven, Connecticut 06510, USA
| | - Yu Zhou
- 1] Sichuan Provincial Key Laboratory for Human Disease Gene Study and Institute of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, Sichuan 610072, China [2] Hospital of University of Electronic Science and Technology of China (UESTC) &Sichuan Provincial People's Hospital, Chengdu, Sichuan 610072, China
| | - Xianjun Zhu
- 1] Sichuan Provincial Key Laboratory for Human Disease Gene Study and Institute of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, Sichuan 610072, China [2] Hospital of University of Electronic Science and Technology of China (UESTC) &Sichuan Provincial People's Hospital, Chengdu, Sichuan 610072, China
| | - Thomas Biederer
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
| | - Michael C Crair
- Department of Neurobiology, Yale University School of Medicine, 333 Cedar Street, SHM B301, New Haven, Connecticut 06510, USA
| | - Bo Chen
- 1] Department of Ophthalmology and Visual Science, Yale University School of Medicine, 300 George Street, Suite 8100, New Haven, Connecticut 06511, USA [2] Department of Neurobiology, Yale University School of Medicine, 333 Cedar Street, SHM B301, New Haven, Connecticut 06510, USA
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168
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A Semiquantitative Framework for Gene Regulatory Networks: Increasing the Time and Quantitative Resolution of Boolean Networks. PLoS One 2015; 10:e0130033. [PMID: 26067297 PMCID: PMC4489432 DOI: 10.1371/journal.pone.0130033] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 05/15/2015] [Indexed: 12/29/2022] Open
Abstract
Boolean models have been instrumental in predicting general features of gene networks and more recently also as explorative tools in specific biological applications. In this study we introduce a basic quantitative and a limited time resolution to a discrete (Boolean) framework. Quantitative resolution is improved through the employ of normalized variables in unison with an additive approach. Increased time resolution stems from the introduction of two distinct priority classes. Through the implementation of a previously published chondrocyte network and T helper cell network, we show that this addition of quantitative and time resolution broadens the scope of biological behaviour that can be captured by the models. Specifically, the quantitative resolution readily allows models to discern qualitative differences in dosage response to growth factors. The limited time resolution, in turn, can influence the reachability of attractors, delineating the likely long term system behaviour. Importantly, the information required for implementation of these features, such as the nature of an interaction, is typically obtainable from the literature. Nonetheless, a trade-off is always present between additional computational cost of this approach and the likelihood of extending the model’s scope. Indeed, in some cases the inclusion of these features does not yield additional insight. This framework, incorporating increased and readily available time and semi-quantitative resolution, can help in substantiating the litmus test of dynamics for gene networks, firstly by excluding unlikely dynamics and secondly by refining falsifiable predictions on qualitative behaviour.
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169
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Focus on the p38 MAPK signaling pathway in bone development and maintenance. BONEKEY REPORTS 2015; 4:711. [PMID: 26131361 DOI: 10.1038/bonekey.2015.80] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 04/24/2015] [Indexed: 01/18/2023]
Abstract
The p38 mitogen-activated protein kinase (MAPK) signaling pathway can be activated in response to a wide range of extracellular signals. As a consequence, it can generate many different biological effects that depend on the stimulus and on the activated cell type. Therefore, this pathway has been found to regulate many aspects of tissue development and homeostasis. Recent work with the aid of genetically modified mice has highlighted the physiological functions of this pathway in skeletogenesis and postnatal bone maintenance. In this review, emphasis is given to the roles of the p38 MAPK pathway in chondrocyte, osteoblast and osteoclast biology. In particular, we describe the molecular mechanisms of p38 MAPK activation and downstream targets. The requirement of this pathway in physiological bone development and homeostasis is demonstrated by the ability of p38 MAPK to regulate master transcription factors controlling geneses and functions of chondrocytes, osteoblasts and osteoclasts.
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170
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Papaioannou G, Mirzamohammadi F, Lisse TS, Nishimori S, Wein MN, Kobayashi T. MicroRNA-140 Provides Robustness to the Regulation of Hypertrophic Chondrocyte Differentiation by the PTHrP-HDAC4 Pathway. J Bone Miner Res 2015; 30:1044-52. [PMID: 25529628 PMCID: PMC5380142 DOI: 10.1002/jbmr.2438] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Revised: 12/10/2014] [Accepted: 12/15/2014] [Indexed: 12/21/2022]
Abstract
Growth plate chondrocytes go through multiple differentiation steps and eventually become hypertrophic chondrocytes. The parathyroid hormone (PTH)-related peptide (PTHrP) signaling pathway plays a central role in regulation of hypertrophic differentiation, at least in part, through enhancing activity of histone deacetylase 4 (HDAC4), a negative regulator of MEF2 transcription factors that drive hypertrophy. We have previously shown that loss of the chondrocyte-specific microRNA (miRNA), miR-140, alters chondrocyte differentiation including mild acceleration of hypertrophic differentiation. Here, we provide evidence that miR-140 interacts with the PTHrP-HDAC4 pathway to control chondrocyte differentiation. Heterozygosity of PTHrP or HDAC4 substantially impaired animal growth in miR-140 deficiency, whereas these mutations had no effect in the presence of miR-140. miR-140-deficient chondrocytes showed increased MEF2C expression with normal levels of total and phosphorylated HDAC4, indicating that the miR-140 pathway merges with the PTHrP-HDAC4 pathway at the level of MEF2C. miR-140 negatively regulated p38 mitogen-activated protein kinase (MAPK) signaling, and inhibition of p38 MAPK signaling reduced MEF2C expression. These results demonstrate that miR-140 ensures the robustness of the PTHrP/HDAC4 regulatory system by suppressing MEF2C-inducing stimuli. © 2014 American Society for Bone and Mineral Research © 2015 American Society for Bone and Mineral Research.
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Affiliation(s)
- Garyfallia Papaioannou
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Fatemeh Mirzamohammadi
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Thomas S Lisse
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Shigeki Nishimori
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Marc N Wein
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Tatsuya Kobayashi
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
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171
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Tsang KY, Tsang SW, Chan D, Cheah KSE. The chondrocytic journey in endochondral bone growth and skeletal dysplasia. ACTA ACUST UNITED AC 2015; 102:52-73. [PMID: 24677723 DOI: 10.1002/bdrc.21060] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2014] [Accepted: 02/23/2014] [Indexed: 12/29/2022]
Abstract
The endochondral bones of the skeleton develop from a cartilage template and grow via a process involving a cascade of chondrocyte differentiation steps culminating in formation of a growth plate and the replacement of cartilage by bone. This process of endochondral ossification, driven by the generation of chondrocytes and their subsequent proliferation, differentiation, and production of extracellular matrix constitute a journey, deviation from which inevitably disrupts bone growth and development, and is the basis of human skeletal dysplasias with a wide range of phenotypic severity, from perinatal lethality to progressively deforming. This highly coordinated journey of chondrocyte specification and fate determination is controlled by a myriad of intrinsic and extrinsic factors. SOX9 is the master transcription factor that, in concert with varying partners along the way, directs the different phases of the journey from mesenchymal condensation, chondrogenesis, differentiation, proliferation, and maturation. Extracellular signals, including bone morphogenetic proteins, wingless-related MMTV integration site (WNT), fibroblast growth factor, Indian hedgehog, and parathyroid hormone-related peptide, are all indispensable for growth plate chondrocytes to align and organize into the appropriate columnar architecture and controls their maturation and transition to hypertrophy. Chondrocyte hypertrophy, marked by dramatic volume increase in phases, is controlled by transcription factors SOX9, Runt-related transcription factor, and FOXA2. Hypertrophic chondrocytes mediate the cartilage to bone transition and concomitantly face a live-or-die situation, a subject of much debate. We review recent insights into the coordination of the phases of the chondrocyte journey, and highlight the need for a systems level understanding of the regulatory networks that will facilitate the development of therapeutic approaches for skeletal dysplasia.
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Affiliation(s)
- Kwok Yeung Tsang
- Department of Biochemistry, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China
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172
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Sun MMG, Beier F. Chondrocyte hypertrophy in skeletal development, growth, and disease. ACTA ACUST UNITED AC 2015; 102:74-82. [PMID: 24677724 DOI: 10.1002/bdrc.21062] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 02/27/2014] [Indexed: 12/31/2022]
Abstract
Most of our bones form through the process of endochondral ossification, which is tightly regulated by the activity of the cartilage growth plate. Chondrocyte maturation through the various stages of growth plate physiology ultimately results in hypertrophy. Chondrocyte hypertrophy is an essential contributor to longitudinal bone growth, but recent data suggest that these cells also play fundamental roles in signaling to other skeletal cells, thus coordinating endochondral ossification. On the other hand, ectopic hypertrophy of articular chondrocytes has been implicated in the pathogenesis of osteoarthritis. Thus, a better understanding of the processes that control chondrocyte hypertrophy in the growth plate as well as in articular cartilage is required for improved management of both skeletal growth disorders and osteoarthritis. This review summarizes recent findings on the regulation of hypertrophic chondrocyte differentiation, the cellular mechanisms involved in hypertrophy, and the role of chondrocyte hypertrophy in skeletal physiology and pathophysiology.
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Affiliation(s)
- Margaret Man-Ger Sun
- Department of Physiology and Pharmacology, Western University, and Children's Health Research Institute, London, Ontario, Canada
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173
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Spatz JM, Wein MN, Gooi JH, Qu Y, Garr JL, Liu S, Barry KJ, Uda Y, Lai F, Dedic C, Balcells-Camps M, Kronenberg HM, Babij P, Pajevic PD. The Wnt Inhibitor Sclerostin Is Up-regulated by Mechanical Unloading in Osteocytes in Vitro. J Biol Chem 2015; 290:16744-58. [PMID: 25953900 DOI: 10.1074/jbc.m114.628313] [Citation(s) in RCA: 197] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Indexed: 11/06/2022] Open
Abstract
Although bone responds to its mechanical environment, the cellular and molecular mechanisms underlying the response of the skeleton to mechanical unloading are not completely understood. Osteocytes are the most abundant but least understood cells in bones and are thought to be responsible for sensing stresses and strains in bone. Sclerostin, a product of the SOST gene, is produced postnatally primarily by osteocytes and is a negative regulator of bone formation. Recent studies show that SOST is mechanically regulated at both the mRNA and protein levels. During prolonged bed rest and immobilization, circulating sclerostin increases both in humans and in animal models, and its increase is associated with a decrease in parathyroid hormone. To investigate whether SOST/sclerostin up-regulation in mechanical unloading is a cell-autonomous response or a hormonal response to decreased parathyroid hormone levels, we subjected osteocytes to an in vitro unloading environment achieved by the NASA rotating wall vessel system. To perform these studies, we generated a novel osteocytic cell line (Ocy454) that produces high levels of SOST/sclerostin at early time points and in the absence of differentiation factors. Importantly, these osteocytes recapitulated the in vivo response to mechanical unloading with increased expression of SOST (3.4 ± 1.9-fold, p < 0.001), sclerostin (4.7 ± 0.1-fold, p < 0.001), and the receptor activator of nuclear factor κΒ ligand (RANKL)/osteoprotegerin (OPG) (2.5 ± 0.7-fold, p < 0.001) ratio. These data demonstrate for the first time a cell-autonomous increase in SOST/sclerostin and RANKL/OPG ratio in the setting of unloading. Thus, targeted osteocyte therapies could hold promise as novel osteoporosis and disuse-induced bone loss treatments by directly modulating the mechanosensing cells in bone.
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Affiliation(s)
- Jordan M Spatz
- From the Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, Harvard-MIT Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Marc N Wein
- From the Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
| | - Jonathan H Gooi
- NorthWest Academic Centre, The University of Melbourne, St. Albans, Victoria 3065, Australia, and
| | - Yili Qu
- From the Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
| | - Jenna L Garr
- From the Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
| | - Shawn Liu
- From the Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
| | - Kevin J Barry
- From the Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
| | - Yuhei Uda
- From the Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
| | - Forest Lai
- From the Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
| | - Christopher Dedic
- From the Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
| | - Mercedes Balcells-Camps
- Harvard-MIT Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, Bioengineering Department, Institut Quimic de Sarria, Ramon Llull University, 08017 Barcelona, Spain
| | - Henry M Kronenberg
- From the Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
| | | | - Paola Divieti Pajevic
- From the Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114,
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174
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Kozhemyakina E, Lassar AB, Zelzer E. A pathway to bone: signaling molecules and transcription factors involved in chondrocyte development and maturation. Development 2015; 142:817-31. [PMID: 25715393 DOI: 10.1242/dev.105536] [Citation(s) in RCA: 359] [Impact Index Per Article: 39.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Decades of work have identified the signaling pathways that regulate the differentiation of chondrocytes during bone formation, from their initial induction from mesenchymal progenitor cells to their terminal maturation into hypertrophic chondrocytes. Here, we review how multiple signaling molecules, mechanical signals and morphological cell features are integrated to activate a set of key transcription factors that determine and regulate the genetic program that induces chondrogenesis and chondrocyte differentiation. Moreover, we describe recent findings regarding the roles of several signaling pathways in modulating the proliferation and maturation of chondrocytes in the growth plate, which is the 'engine' of bone elongation.
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Affiliation(s)
- Elena Kozhemyakina
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Building C-Room 305A, 240 Longwood Avenue, Boston, MA 02115, USA
| | - Andrew B Lassar
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Building C-Room 305A, 240 Longwood Avenue, Boston, MA 02115, USA
| | - Elazar Zelzer
- Weizmann Institute of Science, Department of Molecular Genetics, PO Box 26, Rehovot 76100, Israel
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175
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Omori Y, Kitamura T, Yoshida S, Kuwahara R, Chaya T, Irie S, Furukawa T. Mef2d is essential for the maturation and integrity of retinal photoreceptor and bipolar cells. Genes Cells 2015; 20:408-26. [PMID: 25757744 DOI: 10.1111/gtc.12233] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Accepted: 01/30/2015] [Indexed: 11/29/2022]
Abstract
Mef2 transcription factors play a crucial role in cardiac and skeletal muscle differentiation. We found that Mef2d is highly expressed in the mouse retina and its loss causes photoreceptor degeneration similar to that observed in human retinitis pigmentosa patients. Electroretinograms (ERGs) were severely impaired in Mef2d-/- mice. Immunohistochemistry showed that photoreceptor and bipolar cell synapse protein levels severely decreased in the Mef2d-/- retina. Expression profiling by microarray analysis showed that Mef2d is required for the expression of various genes in photoreceptor and bipolar cells, including cone arrestin, Guca1b, Pde6h and Cacna1s, which encode outer segment and synapse proteins. We also observed that Mef2d synergistically activates the cone arrestin (Arr3) promoter with Crx, suggesting that functional cooperation between Mef2d and Crx is important for photoreceptor cell gene regulation. Taken together, our results show that Mef2d is essential for photoreceptor and bipolar cell gene expression, either independently or cooperatively with Crx.
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Affiliation(s)
- Yoshihiro Omori
- Laboratory for Molecular and Developmental Biology, Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka, 565-0871, Japan; JST, CREST, 3-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
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176
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The control operated by the cell cycle machinery on MEF2 stability contributes to the downregulation of CDKN1A and entry into S phase. Mol Cell Biol 2015; 35:1633-47. [PMID: 25733682 DOI: 10.1128/mcb.01461-14] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 02/23/2015] [Indexed: 02/06/2023] Open
Abstract
MEF2s are pleiotropic transcription factors (TFs) which supervise multiple cellular activities. During the cell cycle, MEF2s are activated at the G0/G1 transition to orchestrate the expression of the immediate early genes in response to growth factor stimulation. Here we show that, in human and murine fibroblasts, MEF2 activities are downregulated during late G1. MEF2C and MEF2D interact with the E3 ligase F-box protein SKP2, which mediates their subsequent degradation through the ubiquitin-proteasome system. The cyclin-dependent kinase 4 (CDK4)/cyclin D1 complex phosphorylates MEF2D on serine residues 98 and 110, and phosphorylation of these residues is an important determinant for SKP2 binding. Unscheduled MEF2 transcription during the cell cycle reduces cell proliferation, whereas its containment sustains DNA replication. The CDK inhibitor p21/CDKN1A gene is a MEF2 target gene required to exert this antiproliferative influence. MEF2C and MEF2D bind a region within the first intron of CDKN1A, presenting epigenetic markers of open chromatin. Importantly, H3K27 acetylation within this regulative region depends on the presence of MEF2D. We propose that following the initial engagement in the G0/G1 transition, MEF2C and MEF2D must be polyubiquitylated and degraded during G1 progression to diminish the transcription of the CDKN1A gene, thus favoring entry into S phase.
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177
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Abstract
Due to a blood supply shortage, articular cartilage has a limited capacity for self-healing once damaged. Articular chondrocytes, cartilage progenitor cells, embryonic stem cells, and mesenchymal stem cells are candidate cells for cartilage regeneration. Significant current attention is paid to improving chondrogenic differentiation capacity; unfortunately, the potential chondrogenic hypertrophy of differentiated cells is largely overlooked. Consequently, the engineered tissue is actually a transient cartilage rather than a permanent one. The development of hypertrophic cartilage ends with the onset of endochondral bone formation which has inferior mechanical properties. In this review, current strategies for inhibition of chondrogenic hypertrophy are comprehensively summarized; the impact of cell source options is discussed; and potential mechanisms underlying these strategies are also categorized. This paper aims to provide guidelines for the prevention of hypertrophy in the regeneration of cartilage tissue. This knowledge may also facilitate the retardation of osteophytes in the treatment of osteoarthritis.
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Affiliation(s)
- Song Chen
- Stem Cell and Tissue Engineering Laboratory, Department of Orthopaedics, West Virginia University, Morgantown, WV 26506, USA
- Department of Joint Surgery, Shanghai Changzheng Hospital, The Second Military Medical University, Shanghai 200003, China
| | - Peiliang Fu
- Department of Joint Surgery, Shanghai Changzheng Hospital, The Second Military Medical University, Shanghai 200003, China
| | - Ruijun Cong
- Department of Orthopaedics, The 10th People's Hospital of Shanghai, Affiliated with Tongji University, Shanghai 200072, China
| | - HaiShan Wu
- Department of Joint Surgery, Shanghai Changzheng Hospital, The Second Military Medical University, Shanghai 200003, China
| | - Ming Pei
- Stem Cell and Tissue Engineering Laboratory, Department of Orthopaedics, West Virginia University, Morgantown, WV 26506, USA
- Exercise Physiology, West Virginia University, Morgantown, WV 26506, USA
- Mechanical and Aerospace Engineering, West Virginia University, Morgantown, WV 26506, USA
- Corresponding author. Stem Cell and Tissue Engineering Laboratory, Department of Orthopaedics, West Virginia University, PO Box 9196, One Medical Center Drive, Morgantown, WV 26506-9196, USA. Tel.: +1 304 293 1072; fax: +1 304 293 7070.
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Zhang X, Zuo X, Yang B, Li Z, Xue Y, Zhou Y, Huang J, Zhao X, Zhou J, Yan Y, Zhang H, Guo P, Sun H, Guo L, Zhang Y, Fu XD. MicroRNA directly enhances mitochondrial translation during muscle differentiation. Cell 2015; 158:607-19. [PMID: 25083871 DOI: 10.1016/j.cell.2014.05.047] [Citation(s) in RCA: 349] [Impact Index Per Article: 38.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 04/15/2014] [Accepted: 05/29/2014] [Indexed: 02/08/2023]
Abstract
MicroRNAs are well known to mediate translational repression and mRNA degradation in the cytoplasm. Various microRNAs have also been detected in membrane-compartmentalized organelles, but the functional significance has remained elusive. Here, we report that miR-1, a microRNA specifically induced during myogenesis, efficiently enters the mitochondria where it unexpectedly stimulates, rather than represses, the translation of specific mitochondrial genome-encoded transcripts. We show that this positive effect requires specific miR:mRNA base-pairing and Ago2, but not its functional partner GW182, which is excluded from the mitochondria. We provide evidence for the direct action of Ago2 in mitochondrial translation by crosslinking immunoprecipitation coupled with deep sequencing (CLIP-seq), functional rescue with mitochondria-targeted Ago2, and selective inhibition of the microRNA machinery in the cytoplasm. These findings unveil a positive function of microRNA in mitochondrial translation and suggest a highly coordinated myogenic program via miR-1-mediated translational stimulation in the mitochondria and repression in the cytoplasm.
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Affiliation(s)
- Xiaorong Zhang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China
| | - Xinxin Zuo
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China
| | - Bo Yang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China
| | - Zongran Li
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China
| | - Yuanchao Xue
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China; Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093-0651, USA
| | - Yu Zhou
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093-0651, USA
| | - Jie Huang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China
| | - Xiaolu Zhao
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China
| | - Jie Zhou
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China
| | - Yun Yan
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China
| | - Huiqiong Zhang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China
| | - Peipei Guo
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China
| | - Hui Sun
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China
| | - Lin Guo
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China
| | - Yi Zhang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China
| | - Xiang-Dong Fu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China; Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093-0651, USA; Institute of Genomic Medicine, University of California, San Diego, La Jolla, CA 92093-0651, USA.
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179
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Zhou G, Jiang X, Zhang H, Lu Y, Liu A, Ma X, Yang G, Yang R, Shen H, Zheng J, Hu Y, Yang X, Zhang WJ, Xie Z. Zbtb20 regulates the terminal differentiation of hypertrophic chondrocytes via repression of Sox9. Development 2015; 142:385-93. [DOI: 10.1242/dev.108530] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The terminal differentiation of hypertrophic chondrocytes is a tightly regulated process that plays a pivotal role in endochondral ossification. As a negative regulator, Sox9 is essentially downregulated in terminally differentiated hypertrophic chondrocytes. However, the underlying mechanism of Sox9 silencing is undefined. Here we show that the zinc finger protein Zbtb20 regulates the terminal differentiation of hypertrophic chondrocytes by repressing Sox9. In the developing skeleton of the mouse, Zbtb20 protein is highly expressed by hypertrophic chondrocytes from late embryonic stages. To determine its physiological role in endochondral ossification, we have generated chondrocyte-specific Zbtb20 knockout mice and demonstrate that disruption of Zbtb20 in chondrocytes results in delayed endochondral ossification and postnatal growth retardation. Zbtb20 deficiency caused a delay in cartilage vascularization and an expansion of the hypertrophic zone owing to reduced expression of Vegfa in the hypertrophic zone. Interestingly, Sox9, a direct suppressor of Vegfa expression, was ectopically upregulated at both mRNA and protein levels in the late Zbtb20-deficient hypertrophic zone. Furthermore, knockdown of Sox9 greatly increased Vegfa expression in Zbtb20-deficient hypertrophic chondrocytes. Our findings point to Zbtb20 as a crucial regulator governing the terminal differentiation of hypertrophic chondrocytes at least partially through repression of Sox9.
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Affiliation(s)
- Guangdi Zhou
- Department of Pathophysiology, Second Military Medical University, Shanghai 200433, China
- Department of Pathophysiology, Second Military Medical University, Shanghai 200433, China
| | - Xuchao Jiang
- Department of Pathophysiology, Second Military Medical University, Shanghai 200433, China
- Department of Pathophysiology, Second Military Medical University, Shanghai 200433, China
| | - Hai Zhang
- Department of Pathophysiology, Second Military Medical University, Shanghai 200433, China
- Department of Pathophysiology, Second Military Medical University, Shanghai 200433, China
| | - Yinzhong Lu
- Department of Pathophysiology, Second Military Medical University, Shanghai 200433, China
| | - Anjun Liu
- Department of Pathophysiology, Second Military Medical University, Shanghai 200433, China
- Department of Cell Biology, Second Military Medical University, Shanghai 200433, China
| | - Xianhua Ma
- Department of Pathophysiology, Second Military Medical University, Shanghai 200433, China
| | - Guan Yang
- Genetic Laboratory of Development and Diseases, Institute of Biotechnology, Beijing 100071, China
| | - Rui Yang
- Department of Pathophysiology, Second Military Medical University, Shanghai 200433, China
| | - Hongxing Shen
- Department of Orthopedics, Changhai Hospital, Shanghai 200433, China
| | - Jianming Zheng
- Department of Pathology, Changhai Hospital, Shanghai 200433, China
| | - Yiping Hu
- Department of Cell Biology, Second Military Medical University, Shanghai 200433, China
| | - Xiao Yang
- Genetic Laboratory of Development and Diseases, Institute of Biotechnology, Beijing 100071, China
| | - Weiping J. Zhang
- Department of Pathophysiology, Second Military Medical University, Shanghai 200433, China
| | - Zhifang Xie
- Department of Pathophysiology, Second Military Medical University, Shanghai 200433, China
- Department of Cell Biology, Second Military Medical University, Shanghai 200433, China
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180
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181
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Johnson RW, Sims NA. Embedded in bone, but looking beyond: osteocalcin, epigenetics and ectopic bone formation (ASBMR 2014). ACTA ACUST UNITED AC 2014. [DOI: 10.1038/bonekey.2014.108] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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182
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Zhou J, Li P, Chen Q, Wei X, Zhao T, Wang Z, Wei L. Mitogen-activated protein kinase p38 induces HDAC4 degradation in hypertrophic chondrocytes. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1853:370-376. [PMID: 25447540 DOI: 10.1016/j.bbamcr.2014.11.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 11/01/2014] [Accepted: 11/04/2014] [Indexed: 10/24/2022]
Abstract
Histone deacetylase 4 (HDAC4) is a critical negative regulator for chondrocyte hypertrophy by binding to and inhibiting Runx2, a critical transcription factor for chondrocyte hypertrophy. It is unclear how HDAC4 expression and stability are regulated during growth plate development. We report here that inhibition of mitogen-activated protein kinase (MAPK) p38 by dominant negative p38 or p38 inhibitor prevents HDAC4 degradation. Mutation of a potential caspase-2 and 3 cleavage site Asp289 stabilizes HDAC4 in chondrocytes. In contrast, constitutively active MAPK kinase 6 (constitutive activator of p38) transgenic mice exhibit decreased HDAC4 content in vivo. We also observed that p38 stimulates caspase-3 activity in chondrocytes. Inhibition of p38 or caspases reduced HDAC4 degradation. HDAC4 inhibited Runx2 promoter activity in a dose-dependent manner and caspase inhibitors further enhanced this inhibition by preventing HDAC4 degradation. Overall, these results demonstrate that p38 promotes HDAC4 degradation by increasing caspase-mediated cleavage, which releases Runx2 from a repressive influence of HDAC4 and promotes the chondrocyte hypertrophy and bone formation.
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Affiliation(s)
- Jingming Zhou
- Department of Orthopaedics, Warren Alpert Medical School of Brown University/Rhode Island Hosptal, Coro West, Suite 402H, 1 Hoppin Street, Providence RI 02903
| | - Pengcui Li
- Department of Orthopaedics, Warren Alpert Medical School of Brown University/Rhode Island Hosptal, Coro West, Suite 402H, 1 Hoppin Street, Providence RI 02903.,Department of Orthopaedics, the Second Hospital of Shanxi Medical University; Shanxi Key Lab of Bone and Soft Tissue Injury Repair. Taiyuan, China
| | - Qian Chen
- Department of Orthopaedics, Warren Alpert Medical School of Brown University/Rhode Island Hosptal, Coro West, Suite 402H, 1 Hoppin Street, Providence RI 02903
| | - Xiaochun Wei
- Department of Orthopaedics, the Second Hospital of Shanxi Medical University; Shanxi Key Lab of Bone and Soft Tissue Injury Repair. Taiyuan, China
| | - Ting Zhao
- Department of Surgery, Boston University, Roger Williams Medical Center, Providence, Rhode Island 02908
| | - Zhengke Wang
- Department of Dermatology Biology, Boston University, Roger Williams Medical Center, Providence, Rhode Island 02908
| | - Lei Wei
- Department of Orthopaedics, Warren Alpert Medical School of Brown University/Rhode Island Hosptal, Coro West, Suite 402H, 1 Hoppin Street, Providence RI 02903.,Department of Orthopaedics, the Second Hospital of Shanxi Medical University; Shanxi Key Lab of Bone and Soft Tissue Injury Repair. Taiyuan, China
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183
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Chen L, Cheng B, Li L, Zhan S, Wang L, Zhong T, Chen Y, Zhang H. The molecular characterization and temporal-spatial expression of myocyte enhancer factor 2 genes in the goat and their association with myofiber traits. Gene 2014; 555:223-30. [PMID: 25447896 DOI: 10.1016/j.gene.2014.11.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 10/16/2014] [Accepted: 11/05/2014] [Indexed: 12/18/2022]
Abstract
The myocyte enhancer factor-2 (MEF2) gene family in vertebrates includes MEF2A, MEF2B, MEF2C, and MEF2D, which have important functions in the regulation of muscular growth and development. To investigate their temporal-spatial expression and functions in the goat, these genes were cloned (accession nos. JN967621-24) and their expression patterns characterized at five postnatal stages (3, 30, 60, 90, and 120days). Association analysis was then applied regarding MEF2 expression levels and myofiber diameter and density. MEF2B was shown to be weakly homologous with other species, the distant branches with other members and the lowest expression levels, suggesting that it is distinct from other family members. Expression of the other three MEF2 genes was widely distributed, but this was largely accumulated in the skeletal muscle and myocardium compared with the viscera at all developmental stages. MEF2A and MEF2D expression levels were higher overall than MEF2B and MEF2C in six tissues, and were significantly positively correlated with the myofiber diameter of the longissimus dorsi. These findings suggest that goat MEF2 genes mainly function in the skeletal muscle and myocardium, and that MEF2A and MEF2D are likely to effectively promote muscular growth and development during postnatal stages. MEF2A expression was highest in the myocardium, where MEF2C expression increased with age, implying that both gene products are related to the growth and development of postnatal myocardium.
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Affiliation(s)
- Li Chen
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 610000, China
| | - Bo Cheng
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 610000, China
| | - Li Li
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 610000, China
| | - Siyuan Zhan
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 610000, China
| | - Linjie Wang
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 610000, China
| | - Tao Zhong
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 610000, China
| | - Yu Chen
- Institute of Nanjiang Yellow Goat Breeding Science, Nanjiang 635600, China
| | - Hongping Zhang
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 610000, China.
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184
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Brommage R, Liu J, Hansen GM, Kirkpatrick LL, Potter DG, Sands AT, Zambrowicz B, Powell DR, Vogel P. High-throughput screening of mouse gene knockouts identifies established and novel skeletal phenotypes. Bone Res 2014; 2:14034. [PMID: 26273529 PMCID: PMC4472125 DOI: 10.1038/boneres.2014.34] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 07/29/2014] [Accepted: 07/31/2014] [Indexed: 12/13/2022] Open
Abstract
Screening gene function in vivo is a powerful approach to discover novel drug targets. We present high-throughput screening (HTS) data for 3 762 distinct global gene knockout (KO) mouse lines with viable adult homozygous mice generated using either gene-trap or homologous recombination technologies. Bone mass was determined from DEXA scans of male and female mice at 14 weeks of age and by microCT analyses of bones from male mice at 16 weeks of age. Wild-type (WT) cagemates/littermates were examined for each gene KO. Lethality was observed in an additional 850 KO lines. Since primary HTS are susceptible to false positive findings, additional cohorts of mice from KO lines with intriguing HTS bone data were examined. Aging, ovariectomy, histomorphometry and bone strength studies were performed and possible non-skeletal phenotypes were explored. Together, these screens identified multiple genes affecting bone mass: 23 previously reported genes (Calcr, Cebpb, Crtap, Dcstamp, Dkk1, Duoxa2, Enpp1, Fgf23, Kiss1/Kiss1r, Kl (Klotho), Lrp5, Mstn, Neo1, Npr2, Ostm1, Postn, Sfrp4, Slc30a5, Slc39a13, Sost, Sumf1, Src, Wnt10b), five novel genes extensively characterized (Cldn18, Fam20c, Lrrk1, Sgpl1, Wnt16), five novel genes with preliminary characterization (Agpat2, Rassf5, Slc10a7, Slc26a7, Slc30a10) and three novel undisclosed genes coding for potential osteoporosis drug targets.
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Affiliation(s)
| | - Jeff Liu
- Lexicon Pharmaceuticals , The Woodlands, TX, USA
| | | | | | | | | | | | | | - Peter Vogel
- Lexicon Pharmaceuticals , The Woodlands, TX, USA
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185
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Gu J, Lu Y, Li F, Qiao L, Wang Q, Li N, Borgia JA, Deng Y, Lei G, Zheng Q. Identification and characterization of the novel Col10a1 regulatory mechanism during chondrocyte hypertrophic differentiation. Cell Death Dis 2014; 5:e1469. [PMID: 25321476 PMCID: PMC4649528 DOI: 10.1038/cddis.2014.444] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Revised: 09/02/2014] [Accepted: 09/03/2014] [Indexed: 02/03/2023]
Abstract
The majority of human skeleton develops through the endochondral pathway, in which cartilage-forming chondrocytes proliferate and enlarge into hypertrophic chondrocytes that eventually undergo apoptosis and are replaced by bone. Although at a terminal differentiation stage, hypertrophic chondrocytes have been implicated as the principal engine of bone growth. Abnormal chondrocyte hypertrophy has been seen in many skeletal dysplasia and osteoarthritis. Meanwhile, as a specific marker of hypertrophic chondrocytes, the type X collagen gene (COL10A1) is also critical for endochondral bone formation, as mutation and altered COL10A1 expression are often accompanied by abnormal chondrocyte hypertrophy in many skeletal diseases. However, how the type X collagen gene is regulated during chondrocyte hypertrophy has not been fully elucidated. We have recently demonstrated that Runx2 interaction with a 150-bp mouse Col10a1 cis-enhancer is required but not sufficient for its hypertrophic chondrocyte-specific reporter expression in transgenic mice, suggesting requirement of additional Col10a1 regulators. In this study, we report in silico sequence analysis of this 150-bp enhancer and identification of its multiple binding factors, including AP1, MEF2, NFAT, Runx1 and TBX5. Using this enhancer as bait, we performed yeast one-hybrid assay and identified multiple candidate Col10a1-interacting genes, including cyclooxygenase 1 (Cox-1) and Cox-2. We have also performed mass spectrometry analysis and detected EF1-alpha, Fus, GdF7 and Runx3 as components of the specific complex formed by the cis-enhancer and nuclear extracts from hypertrophic MCT (mouse chondrocytes immortalized with large T antigen) cells that express Col10a1 abundantly. Notably, some of the candidate genes are differentially expressed in hypertrophic MCT cells and have been associated with chondrocyte hypertrophy and Runx2, an indispensible Col10a1 regulator. Intriguingly, we detected high-level Cox-2 expression in hypertrophic MCT cells. Electrophoretic mobility shift assay and chromatin immunoprecipitation assays confirmed the interaction between Cox-2 and Col10a1 cis-enhancer, supporting its role as a candidate Col10a1 regulator. Together, our data support a Cox-2-containing, Runx2-centered Col10a1 regulatory mechanism, during chondrocyte hypertrophic differentiation.
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Affiliation(s)
- J Gu
- Department of Hematology and Hematological Laboratory Science, School of Medical Science and Laboratory Medicine, Jiangsu University, Zhenjiang, China
| | - Y Lu
- Department of Hematology and Hematological Laboratory Science, School of Medical Science and Laboratory Medicine, Jiangsu University, Zhenjiang, China
- Department of Anatomy and Cell Biology, Rush University Medical Center, Chicago, IL, USA
| | - F Li
- Department of Pathophysiology, Anhui Medical University, Hefei, China
| | - L Qiao
- Department of Hematology and Hematological Laboratory Science, School of Medical Science and Laboratory Medicine, Jiangsu University, Zhenjiang, China
| | - Q Wang
- Department of Hematology and Hematological Laboratory Science, School of Medical Science and Laboratory Medicine, Jiangsu University, Zhenjiang, China
| | - N Li
- Department of Hematology and Hematological Laboratory Science, School of Medical Science and Laboratory Medicine, Jiangsu University, Zhenjiang, China
| | - J A Borgia
- Department of Pathology and Department of Biochemistry, Rush University Medical Center, Chicago, IL, USA
| | - Y Deng
- Department of Internal Medicine and Biochemistry, Rush University Medical Center, Chicago, IL, USA
| | - G Lei
- Department of Orthopaedic Surgery, Xiangya Hospital, Central South University, Changsha, China
| | - Q Zheng
- Department of Hematology and Hematological Laboratory Science, School of Medical Science and Laboratory Medicine, Jiangsu University, Zhenjiang, China
- Department of Anatomy and Cell Biology, Rush University Medical Center, Chicago, IL, USA
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186
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Abstract
Herein, we review the regulation of differentiation of the growth plate chondrocytes by G-proteins. In connection with this, we summarize the current knowledge regarding each family of G-protein α subunit, specifically, Gα(s), Gα(q/11), Gα(12/13), and Gα(i/o). We discuss different mechanisms involved in chondrocyte differentiation downstream of G-proteins and different G-protein-coupled receptors (GPCRs) activating G-proteins in the epiphyseal chondrocytes. We conclude that among all G-proteins and GPCRs expressed by chondrocytes, Gα(s) has the most important role and prevents premature chondrocyte differentiation. Receptor for parathyroid hormone (PTHR1) appears to be the major activator of Gα(s) in chondrocytes and ablation of either one leads to accelerated chondrocyte differentiation, premature fusion of the postnatal growth plate, and ultimately short stature.
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Affiliation(s)
- Andrei S Chagin
- Department of Physiology and PharmacologyKarolinska Institutet, Nanna Svartz Vagen 2, Stockholm 17177, SwedenEndocrine UnitMassachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114-2696, USA
| | - Henry M Kronenberg
- Department of Physiology and PharmacologyKarolinska Institutet, Nanna Svartz Vagen 2, Stockholm 17177, SwedenEndocrine UnitMassachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114-2696, USA
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187
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Funato N, Nakamura M, Richardson JA, Srivastava D, Yanagisawa H. Loss of Tbx1 induces bone phenotypes similar to cleidocranial dysplasia. Hum Mol Genet 2014; 24:424-35. [PMID: 25209980 DOI: 10.1093/hmg/ddu458] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
T-box transcription factor, TBX1, is the major candidate gene for 22q11.2 deletion syndrome (DiGeorge/ Velo-cardio-facial syndrome) characterized by facial defects, thymus hypoplasia, cardiovascular anomalies and cleft palates. Here, we report that the loss of Tbx1 in mouse (Tbx1(-/-)) results in skeletal abnormalities similar to those of cleidocranial dysplasia (CCD) in humans, which is an autosomal-dominant skeletal disease caused by mutations in RUNX2. Tbx1(-/-) mice display short stature, absence of hyoid bone, failed closure of fontanelle, bifid xiphoid process and hypoplasia of clavicle and zygomatic arch. A cell-type-specific deletion of Tbx1 in osteochondro-progenitor (Tbx1(OPKO)) or mesodermal (Tbx1(MKO)) lineage partially recapitulates the Tbx1(-/-) bone phenotypes. Although Tbx1 expression has not been previously reported in neural crest, inactivation of Tbx1 in the neural crest lineage (Tbx1(NCKO)) leads to an absence of the body of hyoid bone and postnatal lethality, indicating an unanticipated role of Tbx1 in neural crest development. Indeed, Tbx1 is expressed in the neural crest-derived hyoid bone primordium, in addition to mesoderm-derived osteochondral progenitors. Ablation of Tbx1 affected Runx2 expression in calvarial bones and overexpression of Tbx1 induced Runx2 expression in vitro. Taken together, our current studies reveal that Tbx1 is required for mesoderm- and neural crest-derived osteoblast differentiation and normal skeletal development. TBX1 mutation could lead to CCD-like bone phenotypes in human.
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Affiliation(s)
- Noriko Funato
- Research Center for Medical and Dental Sciences, Human Gene Sciences Research Division, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510, Japan Department of Molecular Biology and
| | - Masataka Nakamura
- Research Center for Medical and Dental Sciences, Human Gene Sciences Research Division, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510, Japan
| | - James A Richardson
- Department of Pathology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9148, USA and
| | - Deepak Srivastava
- Gladstone Institute of Cardiovascular Disease and Department of Pediatrics, University of California, San Francisco, 1650 Owens Street, San Francisco, CA 94158, USA
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188
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MicroRNAs involved in bone formation. Cell Mol Life Sci 2014; 71:4747-61. [PMID: 25108446 DOI: 10.1007/s00018-014-1700-6] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Revised: 07/31/2014] [Accepted: 08/04/2014] [Indexed: 12/21/2022]
Abstract
During skeletal development, mesenchymal progenitor cells undergo a multistage differentiation process in which they proliferate and become bone- and cartilage-forming cells. This process is tightly regulated by multiple levels of regulatory systems. The small non-coding RNAs, microRNAs (miRNAs), post-transcriptionally regulate gene expression. Recent studies have demonstrated that miRNAs play significant roles in all stages of bone formation, suggesting the possibility that miRNAs can be novel therapeutic targets for skeletal diseases. Here, we review the role and mechanism of action of miRNAs in bone formation. We discuss roles of specific miRNAs in major types of bone cells, osteoblasts, chondrocytes, osteoclasts, and their progenitors. Except a few, the current knowledge about miRNAs in bone formation has been obtained mainly by in vitro studies; further validation of these findings in vivo is awaited. We also discuss about several miRNAs of particular interest in the light of future therapies of bone diseases.
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189
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Amano K, Densmore M, Nishimura R, Lanske B. Indian hedgehog signaling regulates transcription and expression of collagen type X via Runx2/Smads interactions. J Biol Chem 2014; 289:24898-910. [PMID: 25028519 DOI: 10.1074/jbc.m114.570507] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Indian hedgehog (Ihh) is essential for chondrocyte differentiation and endochondral ossification and acts with parathyroid hormone-related peptide in a negative feedback loop to regulate early chondrocyte differentiation and entry to hypertrophic differentiation. Independent of this function, we and others recently reported independent Ihh functions to promote chondrocyte hypertrophy and matrix mineralization in vivo and in vitro. However, the molecular mechanisms for these actions and their functional significance are still unknown. We recently discovered that Ihh overexpression in chondrocytes stimulated the expression of late chondrocyte differentiation markers and induced matrix mineralization. Focusing on collagen type X (Col10α1) expression and transcription, we observed that hedgehog downstream transcription factors GLI-Krüppel family members (Gli) 1/2 increased COL10A1 promoter activity and identified a novel Gli1/2 response element in the 250-bp basic promoter. In addition, we found that Ihh induced Runx2 expression in chondrocytes without up-regulating other modulators of chondrocyte maturation such as Mef2c, Foxa2, and Foxa3. Runx2 promoted Col10α1 expression in cooperation with Ihh. Further analyses using promoter assays, immunofluorescence, and binding assays showed the interaction of Gli1/2 in a complex with Runx2/Smads induces chondrocyte differentiation. Finally, we could demonstrate that Ihh promotes in vitro matrix mineralization using similar molecular mechanisms. Our data provide an in vitro mechanism for Ihh signaling to positively regulate Col10α1 transcription. Thus, Ihh signaling could be an important player for not only early chondrocyte differentiation but maturation and calcification of chondrocytes.
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Affiliation(s)
- Katsuhiko Amano
- From the Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Boston, Massachusetts 02115 and the Departments of Oral and Maxillofacial Surgery and
| | - Michael Densmore
- From the Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Boston, Massachusetts 02115 and
| | - Riko Nishimura
- Molecular and Cellular Biochemistry, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan
| | - Beate Lanske
- From the Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Boston, Massachusetts 02115 and
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190
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Baertschi S, Baur N, Lueders-Lefevre V, Voshol J, Keller H. Class I and IIa histone deacetylases have opposite effects on sclerostin gene regulation. J Biol Chem 2014; 289:24995-5009. [PMID: 25012661 DOI: 10.1074/jbc.m114.564997] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Adult bone mass is controlled by the bone formation repressor sclerostin (SOST). Previously, we have shown that intermittent parathyroid hormone (PTH) bone anabolic therapy involves SOST expression reduction by inhibiting myocyte enhancer factor 2 (MEF2), which activates a distant bone enhancer. Here, we extended our SOST gene regulation studies by analyzing a role of class I and IIa histone deacetylases (HDACs), which are known regulators of MEF2s. Expression analysis using quantitative PCR (qPCR) showed high expression of HDACs 1 and 2, lower amounts of HDACs 3, 5, and 7, low amounts of HDAC4, and no expression of HDACs 8 and 9 in constitutively SOST-expressing UMR106 osteocytic cells. PTH-induced Sost suppression was associated with specific rapid nuclear accumulation of HDAC5 and co-localization with MEF2s in nuclear speckles requiring serine residues 259 and 498, whose phosphorylations control nucleocytoplasmic shuttling. Increasing nuclear levels of HDAC5 in UMR106 by blocking nuclear export with leptomycin B (LepB) or overexpression in transient transfection assays inhibited endogenous Sost transcription and reporter gene expression, respectively. This repressor effect of HDAC5 did not require catalytic activity using specific HDAC inhibitors. In contrast, inhibition of class I HDAC activities and expression using RNA interference suppressed constitutive Sost expression in UMR106 cells. An unbiased comprehensive search for involved HDAC targets using an acetylome analysis revealed several non-histone proteins as candidates. These findings suggest that PTH-mediated Sost repression involves nuclear accumulation of HDAC inhibiting the MEF2-dependent Sost bone enhancer, and class I HDACs are required for constitutive Sost expression in osteocytes.
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Affiliation(s)
| | - Nina Baur
- Developmental and Molecular Pathways, Novartis Institutes for BioMedical Research, 4056 Basel, Switzerland
| | | | - Johannes Voshol
- Developmental and Molecular Pathways, Novartis Institutes for BioMedical Research, 4056 Basel, Switzerland
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191
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Matta C, Mobasheri A, Gergely P, Zákány R. Ser/Thr-phosphoprotein phosphatases in chondrogenesis: neglected components of a two-player game. Cell Signal 2014; 26:2175-85. [PMID: 25007994 DOI: 10.1016/j.cellsig.2014.06.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Accepted: 06/27/2014] [Indexed: 12/13/2022]
Abstract
Protein phosphorylation plays a determining role in the regulation of chondrogenesis in vitro. While signalling pathways governed by protein kinases including PKA, PKC, and mitogen-activated protein kinases (MAPK) have been mapped in great details, published data relating to the specific role of phosphoprotein phosphatases (PPs) in differentiating chondroprogenitor cells or in mature chondrocytes is relatively sparse. This review discusses the known functions of Ser/Thr-specific PPs in the molecular signalling pathways of chondrogenesis. PPs are clearly equally important as protein kinases to counterbalance the effect of reversible protein phosphorylation. Of the main Ser/Thr PPs, some of the functions of PP1, PP2A and PP2B have been characterised in the context of chondrogenesis. While PP1 and PP2A appear to negatively regulate chondrogenic differentiation and maintenance of chondrocyte phenotype, calcineurin is an important stimulatory mediator during chondrogenesis but becomes inhibitory in mature chondrocytes. Furthermore, PPs are implicated to be mediators during the pathogenesis of osteoarthritis that makes them potential therapeutic targets to be exploited in the close future. Among the many yet unexplored targets of PPs, modulation of plasma membrane ion channel function and participation in mechanotransduction pathways are emerging novel aspects of signalling during chondrogenesis that should be further elucidated. Besides the regulation of cellular ion homeostasis, other potentially significant novel roles for PPs during the regulation of in vitro chondrogenesis are discussed.
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Affiliation(s)
- Csaba Matta
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98, H-4032, Debrecen, Hungary; School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Duke of Kent Building, Guildford, Surrey GU2 7XH, United Kingdom.
| | - Ali Mobasheri
- School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Duke of Kent Building, Guildford, Surrey GU2 7XH, United Kingdom; Arthritis Research UK Centre for Sport, Exercise and Osteoarthritis, Arthritis Research UK Pain Centre, Medical Research Council and Arthritis Research UK Centre for Musculoskeletal Ageing Research, University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, United Kingdom; Center of Excellence in Genomic Medicine Research (CEGMR), King Fahd Medical Research Center (KFMRC), King AbdulAziz University, Jeddah, 21589, Kingdom of Saudi Arabia
| | - Pál Gergely
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98, H-4032, Debrecen, Hungary
| | - Róza Zákány
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98, H-4032, Debrecen, Hungary
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192
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Leung C, Wilson Y, Khuong TM, Neely GG. Fruit flies as a powerful model to drive or validate pain genomics efforts. Pharmacogenomics 2014; 14:1879-87. [PMID: 24236487 DOI: 10.2217/pgs.13.196] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Chronic pain is a disabling condition that persists even after normal healing processes are complete and presents considerable physical, psychological and financial burdens for patients globally. However, current analgesic treatments do not meet clinical needs. Here, we review genomic and pharmacogenomic studies of pain in humans and nociception in the fruit fly Drosophila melanogaster, and provide evidence supporting the use of fly genetics to compliment genome-wide and pharmacogenomic studies of human conditions, such as pain. Combining genomic and pharmacogenomic techniques to study chronic pain in humans with functional genomic assessment in model organisms may provide molecular rationale for developing more personalized or improving generalized chronic pain therapies.
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Affiliation(s)
- Calvin Leung
- Neuroscience Program, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, Sydney, NSW 2010, Australia
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193
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Juszczuk-Kubiak E, Wicińska K, Starzyński RR. Postnatal expression patterns and polymorphism analysis of the bovine myocyte enhancer factor 2C (Mef2C) gene. Meat Sci 2014; 98:753-8. [PMID: 25108515 DOI: 10.1016/j.meatsci.2014.06.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 06/13/2014] [Indexed: 10/25/2022]
Abstract
The aim of this study was to analyze the level of expression of the Mef2C gene in the developing bovine longissimus dorsi (LD) muscle (at 6, 9 and 12months of age) and to evaluate differences in expression among Polish Holstein-Friesian (HO) and Limousine (LM) bulls. Moreover, the expression patterns of Mef2C in different tissues were determined. The results showed that Mef2C mRNA was expressed at a high level in adult skeletal and cardiac muscles. Moreover, Mef2C expression was markedly lower in the semitendinosus (ST) than in the gluteus medius (GM) and LD muscles. A relatively higher Mef2C mRNA and MEF2C protein level was estimated in the muscles of HO bulls at the age of 12months in comparison with its lower expression in LM bulls. Furthermore, we found that the Mef2C promoter variant (GU211004:g.-1606C>T) does not affect the level of mRNA in the LD and ST muscles of 12-month-old HO bulls.
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Affiliation(s)
- E Juszczuk-Kubiak
- Department of Molecular Cytogenetics, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, Jastrzębiec, Poland.
| | - K Wicińska
- Department of Molecular Cytogenetics, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, Jastrzębiec, Poland
| | - R R Starzyński
- Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, Jastrzębiec, Poland
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194
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Obri A, Makinistoglu MP, Zhang H, Karsenty G. HDAC4 integrates PTH and sympathetic signaling in osteoblasts. ACTA ACUST UNITED AC 2014; 205:771-80. [PMID: 24934156 PMCID: PMC4068141 DOI: 10.1083/jcb.201403138] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Parathyroid hormone (PTH) and the sympathetic tone promote Rankl expression in osteoblasts and osteoclast differentiation by enhancing cyclic adenosine monophosphate production through an unidentified transcription factor for PTH and through ATF4 for the sympathetic tone. How two extracellular cues using the same second messenger in the same cell elicit different transcriptional events is unknown. In this paper, we show that PTH favors Rankl expression by triggering the ubiquitination of HDAC4, a class II histone deacetylase, via Smurf2. HDAC4 degradation releases MEF2c, which transactivates the Rankl promoter. Conversely, sympathetic signaling in osteoblasts favors the accumulation of HDAC4 in the nucleus and its association with ATF4. In this context, HDAC4 increases Rankl expression. Because of its ability to differentially connect two extracellular cues to the genome of osteoblasts, HDAC4 is a critical regulator of osteoclast differentiation.
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Affiliation(s)
- Arnaud Obri
- Department of Genetics and Development, Columbia University, New York, NY 10032
| | | | - Hong Zhang
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA 01655
| | - Gerard Karsenty
- Department of Genetics and Development, Columbia University, New York, NY 10032
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195
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Lu Y, Qiao L, Lei G, Mira RR, Gu J, Zheng Q. Col10a1 gene expression and chondrocyte hypertrophy during skeletal development and disease. ACTA ACUST UNITED AC 2014. [DOI: 10.1007/s11515-014-1310-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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196
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RNA-binding protein AUF1 promotes myogenesis by regulating MEF2C expression levels. Mol Cell Biol 2014; 34:3106-19. [PMID: 24891619 DOI: 10.1128/mcb.00423-14] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The mammalian RNA-binding protein AUF1 (AU-binding factor 1, also known as heterogeneous nuclear ribonucleoprotein D [hnRNP D]) binds to numerous mRNAs and influences their posttranscriptional fate. Given that many AUF1 target mRNAs encode muscle-specific factors, we investigated the function of AUF1 in skeletal muscle differentiation. In mouse C2C12 myocytes, where AUF1 levels rise at the onset of myogenesis and remain elevated throughout myocyte differentiation into myotubes, RNP immunoprecipitation (RIP) analysis indicated that AUF1 binds prominently to Mef2c (myocyte enhancer factor 2c) mRNA, which encodes the key myogenic transcription factor MEF2C. By performing mRNA half-life measurements and polysome distribution analysis, we found that AUF1 associated with the 3' untranslated region (UTR) of Mef2c mRNA and promoted MEF2C translation without affecting Mef2c mRNA stability. In addition, AUF1 promoted Mef2c gene transcription via a lesser-known role of AUF1 in transcriptional regulation. Importantly, lowering AUF1 delayed myogenesis, while ectopically restoring MEF2C expression levels partially rescued the impairment of myogenesis seen after reducing AUF1 levels. We propose that MEF2C is a key effector of the myogenesis program promoted by AUF1.
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197
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Direct evidence for pitavastatin induced chromatin structure change in the KLF4 gene in endothelial cells. PLoS One 2014; 9:e96005. [PMID: 24797675 PMCID: PMC4010393 DOI: 10.1371/journal.pone.0096005] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 04/02/2014] [Indexed: 01/11/2023] Open
Abstract
Statins exert atheroprotective effects through the induction of specific transcriptional factors in multiple organs. In endothelial cells, statin-dependent atheroprotective gene up-regulation is mediated by Kruppel-like factor (KLF) family transcription factors. To dissect the mechanism of gene regulation, we sought to determine molecular targets by performing microarray analyses of human umbilical vein endothelial cells (HUVECs) treated with pitavastatin, and KLF4 was determined to be the most highly induced gene. In addition, it was revealed that the atheroprotective genes induced with pitavastatin, such as nitric oxide synthase 3 (NOS3) and thrombomodulin (THBD), were suppressed by KLF4 knockdown. Myocyte enhancer factor-2 (MEF2) family activation is reported to be involved in pitavastatin-dependent KLF4 induction. We focused on MEF2C among the MEF2 family members and identified a novel functional MEF2C binding site 148 kb upstream of the KLF4 gene by chromatin immunoprecipitation along with deep sequencing (ChIP-seq) followed by luciferase assay. By applying whole genome and quantitative chromatin conformation analysis {chromatin interaction analysis with paired end tag sequencing (ChIA-PET), and real time chromosome conformation capture (3C) assay}, we observed that the MEF2C-bound enhancer and transcription start site (TSS) of KLF4 came into closer spatial proximity by pitavastatin treatment. 3D-Fluorescence in situ hybridization (FISH) imaging supported the conformational change in individual cells. Taken together, dynamic chromatin conformation change was shown to mediate pitavastatin-responsive gene induction in endothelial cells.
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198
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G-protein stimulatory subunit alpha and Gq/11α G-proteins are both required to maintain quiescent stem-like chondrocytes. Nat Commun 2014; 5:3673. [PMID: 24781502 DOI: 10.1038/ncomms4673] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Accepted: 03/17/2014] [Indexed: 12/21/2022] Open
Abstract
Round chondrocytes in the resting zone of the growth plate provide precursors for columnar chondrocytes and have stem-like properties. Here we demonstrate that these stem-like chondrocytes undergo apoptosis in the absence of the receptor (PPR) for parathyroid hormone-related protein. We examine the possible roles of heterotrimeric G-proteins activated by the PPR. Inactivation of the G-protein stimulatory α-subunit (G(s)α) leads to accelerated differentiation of columnar chondrocytes, as seen in the PPR knockout, but a remnant of growth cartilage remains, in contrast to disappearance of the growth cartilage in the PPR knockout. Stem-like chondrocytes lose their quiescence and proliferate upon G(s)α ablation. Inactivation of G(s)α in mice with a mutant PPR that cannot activate G proteins, Gq and G11, leads to a PPR knockout-like phenotype. Thus, G(s)α is the major mediator of the anti-differentiation action of the PPR, while activation of both G(s)α and Gq/11α is required for quiescence of stem-like chondrocytes.
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199
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Johnson ME, Deliard S, Zhu F, Xia Q, Wells AD, Hankenson KD, Grant SFA. A ChIP-seq-defined genome-wide map of MEF2C binding reveals inflammatory pathways associated with its role in bone density determination. Calcif Tissue Int 2014; 94:396-402. [PMID: 24337390 DOI: 10.1007/s00223-013-9824-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Accepted: 11/30/2013] [Indexed: 01/08/2023]
Abstract
Genome-wide association studies (GWAS) have demonstrated that genetic variation at the MADS box transcription enhancer factor 2, polypeptide C (MEF2C) locus is robustly associated with bone mineral density, primarily at the femoral neck. MEF2C is a transcription factor known to operate via the Wnt signaling pathway. Our hypothesis was that MEF2C regulates the expression of a set of molecular pathways critical to skeletal function. Drawing on our laboratory and bioinformatic experience with ChIP-seq, we analyzed ChIP-seq data for MEF2C available via the ENCODE project to gain insight in to its global genomic binding pattern. We aligned the ChIP-seq data generated for GM12878 (an established lymphoblastoid cell line) and, using the analysis package HOMER, a total of 17,611 binding sites corresponding to 8,118 known genes were observed. We then performed a pathway analysis of the gene list using Ingenuity. At 5 kb, the gene list yielded 'EIF2 Signaling' as the most significant annotation, with a P value of 5.01 × 10(-26). Moving further out, this category remained the top pathway at 50 and 100 kb, then dropped to just second place at 500 kb and beyond by 'Molecular Mechanisms of Cancer'. In addition, at 50 kb and beyond 'RANK Signaling in Osteoclasts' was a consistent feature and resonates with the main general finding from GWAS of bone density. We also observed that MEF2C binding sites were significantly enriched primarily near inflammation associated genes identified from GWAS; indeed, a similar enrichment for inflammation genes has been reported previously using a similar approach for the vitamin D receptor, an established key regulator of bone turnover. Our analyses point to known connective tissue and skeletal processes but also provide novel insights in to networks involved in skeletal regulation. The fact that a specific GWAS category is enriched points to a possible role of inflammation through which it impacts bone mineral density.
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Affiliation(s)
- Matthew E Johnson
- Division of Human Genetics, The Children's Hospital of Philadelphia Research Center, Rm 1216, 3615 Civic Center Blvd, Philadelphia, PA, 19104, USA
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200
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Guérit D, Brondello JM, Chuchana P, Philipot D, Toupet K, Bony C, Jorgensen C, Noël D. FOXO3A regulation by miRNA-29a Controls chondrogenic differentiation of mesenchymal stem cells and cartilage formation. Stem Cells Dev 2014; 23:1195-205. [PMID: 24467486 DOI: 10.1089/scd.2013.0463] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Skeletal development and cartilage formation require stringent regulation of gene expression for mesenchymal stem cells (MSCs) to progress through stages of differentiation. Since microRNAs (miRNAs) regulate biological processes, the objective of the present study was to identify novel miRNAs involved in the modulation of chondrogenesis. We performed miRNA profiling and identify miR-29a as being one of the most down-regulated miRNAs during the chondrogenesis. Using chromatin immunoprecipitation, we showed that SOX9 down-regulates its transcription. Moreover, the over-expression of miR-29a strongly inhibited the expression of chondrocyte-specific markers during in vitro chondrogenic differentiation of MSCs. We identified FOXO3A as a direct target of miR-29a and showed a down- and up-regulation of FOXO3a protein levels after transfection of, respectively, premiR- and antagomiR-29a oligonucleotides. Finally, we showed that using the siRNA or premiR approach, chondrogenic differentiation was inhibited to a similar extent. Together, we demonstrate that the down-regulation of miR-29a, concomitantly with FOXO3A up-regulation, is essential for the differentiation of MSCs into chondrocytes and in vivo cartilage/bone formation. The delivery of miRNAs that modulate MSC chondrogenesis may be applicable for cartilage regeneration and deserves further investigation.
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Affiliation(s)
- David Guérit
- 1 Inserm, U 844, Hôpital Saint-Eloi , Montpellier, France
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