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Chen Y, Mehmood K, Chang YF, Tang Z, Li Y, Zhang H. The molecular mechanisms of glycosaminoglycan biosynthesis regulating chondrogenesis and endochondral ossification. Life Sci 2023; 335:122243. [PMID: 37949211 DOI: 10.1016/j.lfs.2023.122243] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 10/23/2023] [Accepted: 11/02/2023] [Indexed: 11/12/2023]
Abstract
Disorders of chondrocyte differentiation and endochondral osteogenesis are major underlying factors in skeletal developmental disorders, including tibial dysplasia (TD), osteoarthritis (OA), chondrodysplasia (ACH), and multiple epiphyseal dysplasia (MED). Understanding the cellular and molecular pathogenesis of these disorders is crucial for addressing orthopedic diseases resulting from impaired glycosaminoglycan synthesis. Glycosaminoglycan is a broad term that refers to the glycan component of proteoglycan macromolecules. It is an essential component of the cartilage extracellular matrix and plays a vital role in various biological processes, including gene transcription, signal transduction, and chondrocyte differentiation. Recent studies have demonstrated that glycosaminoglycan biosynthesis plays a regulatory role in chondrocyte differentiation and endochondral osteogenesis by modulating various growth factors and signaling molecules. For instance, glycosaminoglycan is involved in mediating pathways such as Wnt, TGF-β, FGF, Ihh-PTHrP, and O-GlcNAc glycosylation, interacting with transcription factors SOX9, BMPs, TGF-β, and Runx2 to regulate chondrocyte differentiation and endochondral osteogenesis. To propose innovative approaches for addressing orthopedic diseases caused by impaired glycosaminoglycan biosynthesis, we conducted a comprehensive review of the molecular mechanisms underlying chondrocyte glycosaminoglycan biosynthesis, which regulates chondrocyte differentiation and endochondral osteogenesis. Our analysis considers the role of genes, glycoproteins, and associated signaling pathways during chondrogenesis and endochondral ossification.
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Affiliation(s)
- Yongjian Chen
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
| | - Khalid Mehmood
- Faculty of Veterinary and Animal Sciences, The Islamia University of Bahawalpur, 63100, Pakistan
| | - Yung-Fu Chang
- College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Zhaoxin Tang
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
| | - Ying Li
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
| | - Hui Zhang
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China.
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Xu Z, Chen S, Feng D, Liu Y, Wang Q, Gao T, Liu Z, Zhang Y, Chen J, Qiu L. Biological role of heparan sulfate in osteogenesis: A review. Carbohydr Polym 2021; 272:118490. [PMID: 34420746 DOI: 10.1016/j.carbpol.2021.118490] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Revised: 07/23/2021] [Accepted: 07/23/2021] [Indexed: 12/14/2022]
Abstract
Heparan sulfate (HS) is extensively expressed in cells, for example, cell membrane and extracellular matrix of most mammalian cells and tissues, playing a key role in the growth and development of life by maintaining homeostasis and implicating in the etiology and diseases. Recent studies have revealed that HS is involved in osteogenesis via coordinating multiple signaling pathways. The potential effect of HS on osteogenesis is a complicated and delicate biological process, which involves the participation of osteocytes, chondrocytes, osteoblasts, osteoclasts and a variety of cytokines. In this review, we summarized the structural and functional characteristics of HS and highlighted the molecular mechanism of HS in bone metabolism to provide novel research perspectives for the further medical research.
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Affiliation(s)
- Zhujie Xu
- Department of Orthopedics, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi, Jiangsu 214023, PR China
| | - Shayang Chen
- Department of Orthopedics, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi, Jiangsu 214023, PR China
| | - Dehong Feng
- Department of Orthopedics, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi, Jiangsu 214023, PR China
| | - Yi Liu
- Department of Orthopedics, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi, Jiangsu 214023, PR China.
| | - Qiqi Wang
- Department of Orthopedics, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi, Jiangsu 214023, PR China
| | - Tianshu Gao
- Department of Orthopedics, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi, Jiangsu 214023, PR China
| | - Zhenwei Liu
- Department of Orthopedics, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi, Jiangsu 214023, PR China
| | - Yan Zhang
- School of Pharmaceutical Sciences, Jiangnan University, Wuxi 214122, PR China
| | - Jinghua Chen
- School of Pharmaceutical Sciences, Jiangnan University, Wuxi 214122, PR China
| | - Lipeng Qiu
- School of Pharmaceutical Sciences, Jiangnan University, Wuxi 214122, PR China.
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Chang Y, Yu D, Chu W, Liu Z, Li H, Zhai Z. LncRNA expression profiles and the negative regulation of lncRNA-NOMMUT037835.2 in osteoclastogenesis. Bone 2020; 130:115072. [PMID: 31593824 DOI: 10.1016/j.bone.2019.115072] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2018] [Revised: 09/10/2019] [Accepted: 09/14/2019] [Indexed: 12/19/2022]
Abstract
Bone is a rigid and dynamic organ that continuously undergoes remodeling and repair. The balance between osteoblastic bone formation and osteoclastic bone resorption is essential for normal bone homeostasis. Osteoclasts are giant multinucleated cells derived from the monocyte/macrophage hematopoietic lineage and are regulated by various cytokines. Long non-coding (lnc) RNAs are known to regulate many biological processes in the skeletal system in both normal and diseased states; however, the lncRNA-mediated regulation of osteoclastogenesis has not been extensively studied. Hence, in the present study, we performed microarray analysis of lncRNAs expressed during different stages of osteoclast differentiation and fusion. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses revealed the biological functions of target genes of lncRNAs that were specifically up- or downregulated at the different stages. Microarray and bioinformatic prediction results were used to generate co-expression networks of lncRNAs-mRNAs and lncRNAs-transcription factors. Based on the analysis, we identified one lncRNA, NONMMUT037835.2, which plays an important role during osteoclastogenesis. Upregulation of lncRNA-NONMMUT037835.2 inhibited osteoclastic differentiation, whereas downregulation of lncRNA-NONMMUT037835.2 promoted osteoclast formation and fusion. Our study also indicated that lncRNA-NOMMUT037835.2 might regulated osteoclastogenesis through negatively regulating RANK expression and inhibiting NF-κB/MAPK signaling pathway. Our results lead to a better understanding of the molecular mechanisms and provided a theoretical basis for developing therapeutic agents for diseases related to dysregulation of bone homeostasis.
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Affiliation(s)
- Yongyun Chang
- Shanghai Key Laboratory of Orthopaedic Implants, Department of Orthopaedics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China; Department of Orthopaedics, Renji Hospital, School of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Degang Yu
- Shanghai Key Laboratory of Orthopaedic Implants, Department of Orthopaedics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
| | - Wenxiang Chu
- Shanghai Key Laboratory of Orthopaedic Implants, Department of Orthopaedics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
| | - Zhiqing Liu
- Shanghai Key Laboratory of Orthopaedic Implants, Department of Orthopaedics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
| | - Huiwu Li
- Shanghai Key Laboratory of Orthopaedic Implants, Department of Orthopaedics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China.
| | - Zanjing Zhai
- Shanghai Key Laboratory of Orthopaedic Implants, Department of Orthopaedics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China.
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Lee G, Kim B, Ko Y, Park M, Kim D, Ryu KH, Jun YC, Sohn HM, Lim W. Regulation of RANKL-Induced Osteoclastogenesis by 635-nm Light-Emitting Diode Irradiation Via HSP27 in Bone Marrow-Derived Macrophages. Photomed Laser Surg 2016; 35:78-86. [PMID: 27626322 DOI: 10.1089/pho.2016.4134] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
OBJECTIVE This study was designed to investigate the effect of 635-nm irradiation from a light-emitting diode (LED) on osteoclastogenesis in receptor activator of nuclear factor kappa-B (NF-κB) ligand (RANKL)-stimulated mouse bone marrow-derived macrophages (BMMs). We determined whether 635-nm irradiation modulated the RANKL-induced osteoclastic signaling pathway in heat shock protein-27 (HSP27)-silenced cells and analyzed the functional cross talk between these factors in osteoclastic differentiation and activation. BACKGROUND HSP27, a member of the small HSP family, regulates oxidative stress. Clinical reports suggest that low-level laser therapy or LED therapy (LEDT) could be an effective alternative treatment for osteolytic bone disease. METHODS In control or HSP27-siRNA-treated BMMs, the effects of LED irradiation with 635 nm and 5 mW/cm2 on RANKL-induced osteoclastic differentiation and activity were assessed by measuring tartrate-resistant acid phosphatase (TRAP) and resorption pit formation. Quantitative real-time polymerase chain reaction and western blot assays were carried out to assess the mRNA expression of osteoclastogenesis-related genes and phosphorylation of c-Jun-N-terminal kinase (JNK), extracellular signal-regulated kinase 1/2 (ERK1/2), AKT, and p38, respectively. Intracellular reactive oxygen species (ROS) generation was measured using the 2',7'-dichlorodihydrofluorescein diacetate (H2DCF-DA) detection method. RESULTS The 635-nm irradiation treatment significantly increased HSP27 expression and decreased intracellular ROS generation, as well as p38 and AKT phosphorylation, leading to reductions in the expression of c-fos, NFATc1, and DC-STAMP and TRAP activation and osteoclastic bone resorption in RANKL-induced BMMs. However, in HSP27-silenced BMMs, no change was observed. CONCLUSIONS Thus, 635-nm irradiation modulates RANKL-induced osteoclastogenesis via HSP27 in BMMs. Thus, HSP27 may play a role in regulating the osteoclastic response to LEDT.
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Affiliation(s)
- Gwangchul Lee
- 1 Department of Orthopedic Surgery, Chosun University Hospital , Gwangju, Korea
| | - Bora Kim
- 2 Department of Premedical Science, College of Medicine, Chosun University , Gwangju, Korea
| | - Youngjong Ko
- 2 Department of Premedical Science, College of Medicine, Chosun University , Gwangju, Korea
| | - Mineon Park
- 2 Department of Premedical Science, College of Medicine, Chosun University , Gwangju, Korea
| | - Donghwi Kim
- 1 Department of Orthopedic Surgery, Chosun University Hospital , Gwangju, Korea
| | - Kang Hyeon Ryu
- 1 Department of Orthopedic Surgery, Chosun University Hospital , Gwangju, Korea
| | - Yong Cheol Jun
- 1 Department of Orthopedic Surgery, Chosun University Hospital , Gwangju, Korea
| | - Hong Moon Sohn
- 1 Department of Orthopedic Surgery, Chosun University Hospital , Gwangju, Korea
| | - Wonbong Lim
- 1 Department of Orthopedic Surgery, Chosun University Hospital , Gwangju, Korea.,2 Department of Premedical Science, College of Medicine, Chosun University , Gwangju, Korea
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Johnsson M, Jonsson KB, Andersson L, Jensen P, Wright D. Genetic regulation of bone metabolism in the chicken: similarities and differences to Mammalian systems. PLoS Genet 2015; 11:e1005250. [PMID: 26023928 PMCID: PMC4449198 DOI: 10.1371/journal.pgen.1005250] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 04/28/2015] [Indexed: 11/19/2022] Open
Abstract
Birds have a unique bone physiology, due to the demands placed on them through egg production. In particular their medullary bone serves as a source of calcium for eggshell production during lay and undergoes continuous and rapid remodelling. We take advantage of the fact that bone traits have diverged massively during chicken domestication to map the genetic basis of bone metabolism in the chicken. We performed a quantitative trait locus (QTL) and expression QTL (eQTL) mapping study in an advanced intercross based on Red Junglefowl (the wild progenitor of the modern domestic chicken) and White Leghorn chickens. We measured femoral bone traits in 456 chickens by peripheral computerised tomography and femoral gene expression in a subset of 125 females from the cross with microarrays. This resulted in 25 loci for female bone traits, 26 loci for male bone traits and 6318 local eQTL loci. We then overlapped bone and gene expression loci, before checking for an association between gene expression and trait values to identify candidate quantitative trait genes for bone traits. A handful of our candidates have been previously associated with bone traits in mice, but our results also implicate unexpected and largely unknown genes in bone metabolism. In summary, by utilising the unique bone metabolism of an avian species, we have identified a number of candidate genes affecting bone allocation and metabolism. These findings can have ramifications not only for the understanding of bone metabolism genetics in general, but could also be used as a potential model for osteoporosis as well as revealing new aspects of vertebrate bone regulation or features that distinguish avian and mammalian bone. In this work we seek to further the understanding of bone genetics by mapping bone traits and gene expression in the chicken. Bone in female birds is special due to egg production. In this study, we combine the genetic mapping of bone traits with bone gene expression to find candidate quantitative trait genes that explain the differences between wild and domestic chickens in terms of bone production. The concept of combining genetic mapping and gene expression mapping is not new, and has already been successful in isolating bone-related genes in mammals, however this is the first time it has been applied to an avian system with such unique bone modelling processes. We aim to reveal new molecular mechanisms of bone regulation, and many of the candidates we find are new, highlighting the potential this technique has to identify the potential differences between avian and mammalian bone biology.
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Affiliation(s)
- Martin Johnsson
- AVIAN Behavioural Genomics and Physiology group, IFM Biology, Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden
| | - Kenneth B. Jonsson
- Department of Surgical Sciences, Orthopaedics, Akademiska Sjukhuset, Uppsala University, Uppsala, Sweden
| | - Leif Andersson
- Department of Medical Biochemistry and Microbiology, BMC, Uppsala University, Uppsala, Sweden
| | - Per Jensen
- AVIAN Behavioural Genomics and Physiology group, IFM Biology, Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden
| | - Dominic Wright
- AVIAN Behavioural Genomics and Physiology group, IFM Biology, Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden
- * E-mail:
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Kyrgidis A, Triaridis S, Vahtsevanos K, Antoniades K. Osteonecrosis of the jaw and bisphosphonate use in breast cancer patients. Expert Rev Anticancer Ther 2014; 9:1125-34. [DOI: 10.1586/era.09.74] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Yoo HJ, Yoon SS, Park SY, Lee EY, Lee EB, Kim JH, Song YW. Gene expression profile during chondrogenesis in human bone marrow derived mesenchymal stem cells using a cDNA microarray. J Korean Med Sci 2011; 26:851-8. [PMID: 21738335 PMCID: PMC3124712 DOI: 10.3346/jkms.2011.26.7.851] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Accepted: 04/27/2011] [Indexed: 01/06/2023] Open
Abstract
Mesenchymal stem cells (MSCs) have the capacity to proliferate and differentiate into multiple connective tissue lineages, which include cartilage, bone, and fat. Cartilage differentiation and chondrocyte maturation are required for normal skeletal development, but the intracellular pathways regulating this process remain largely unclear. This study was designed to identify novel genes that might help clarify the molecular mechanisms of chondrogenesis. Chondrogenesis was induced by culturing human bone marrow (BM) derived MSCs in micromass pellets in the presence of defined medium for 3, 7, 14 or 21 days. Several genes regulated during chondrogenesis were then identified by reverse transcriptase-polymerase chain reaction (RT-PCR). Using an ABI microarray system, we determined the differential gene expression profiles of differentiated chondrocytes and BM-MSCs. Normalization of this data resulted in the identification of 1,486 differentially expressed genes. To verify gene expression profiles determined by microarray analysis, the expression levels of 10 genes with high fold changes were confirmed by RT-PCR. Gene expression patterns of 9 genes (Hrad6B, annexinA2, BMP-7, contactin-1, peroxiredoxin-1, heat shock transcription factor-2, synaptotagmin IV, serotonin receptor-7, Axl) in RT-PCR were similar to the microarray gene expression patterns. These findings provide novel information concerning genes involved in the chondrogenesis of human BM-MSCs.
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Affiliation(s)
- Hyun Jung Yoo
- Department of Internal Medicine, Rheumatism Research Institute, Seoul National University College of Medicine, Seoul, Korea
| | - Sung Soo Yoon
- Department of Internal Medicine, Rheumatism Research Institute, Seoul National University College of Medicine, Seoul, Korea
| | - Seon Yang Park
- Department of Internal Medicine, Rheumatism Research Institute, Seoul National University College of Medicine, Seoul, Korea
| | - Eun Young Lee
- Department of Internal Medicine, Rheumatism Research Institute, Seoul National University College of Medicine, Seoul, Korea
| | - Eun Bong Lee
- Department of Internal Medicine, Rheumatism Research Institute, Seoul National University College of Medicine, Seoul, Korea
| | - Ju Han Kim
- Graduate Course of Biomedical Informatics (SNUBI), Seoul National University College of Medicine, Seoul, Korea
| | - Yeong Wook Song
- Department of Internal Medicine, Rheumatism Research Institute, Seoul National University College of Medicine, Seoul, Korea
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Sundaram K, Senn J, Yuvaraj S, Rao DS, Reddy SV. FGF-2 stimulation of RANK ligand expression in Paget's disease of bone. Mol Endocrinol 2009; 23:1445-54. [PMID: 19556344 DOI: 10.1210/me.2009-0078] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Receptor activator for nuclear factor-kappaB ligand (RANKL), a critical osteoclastogenic factor expressed in marrow stromal/preosteoblast cells is up-regulated in Paget's disease of bone (PDB). We previously demonstrated that heat-shock factor-2 (HSF-2) is a downstream target of fibroblast growth factor-2 (FGF-2) signaling to induce RANKL expression in bone marrow stromal/preosteoblast cells. In this study, we identified a 2.5-fold increase in serum FGF-2 levels in patients (n = 8) with PDB compared with normal subjects (n = 10). We showed that HSF-2 co-immunoprecipitates with heat-shock protein-27 (HSP-27) and that FGF-2 stimulation significantly increased phospho-HSP-27 levels in marrow stromal cells. Confocal microscopy revealed HSF-2 colocalization with HSP-27 in unstimulated cells and HSF-2 nuclear translocation upon FGF-2 stimulation. We further show that FGF-2 stimulation significantly increased the levels of phosphorylated signal transducers and activators of the transcription (p-STAT-1) in these cells. Western blot analysis confirmed that small interfering RNA suppression of STAT-1 significantly decreased (3.2-fold) RANKL expression and promoter activity in FGF-2-stimulated cells. Chromatin immunoprecipitation assay revealed STAT-1 binding to a putative motif located far upstream (-8 kb) in the hRANKL gene promoter region. These results suggest STAT-1 is a downstream effector of FGF-2 signaling and that elevated levels of FGF-2 stimulates RANKL expression in PDB.
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Affiliation(s)
- Kumaran Sundaram
- Charles P. Darby Children's Research Institute, Medical University of South Carolina, Charleston, South Carolina 29425, USA
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Kyrgidis A, Triaridis S, Antoniades K. Effects of bisphosphonates on keratinocytes and fibroblasts having a role in the development of osteonecrosis of the jaw. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/j.bihy.2009.02.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Sundaram K, Mani SK, Kitatani K, Wu K, Pestell RG, Reddy SV. DACH1 negatively regulates the human RANK ligand gene expression in stromal/preosteoblast cells. J Cell Biochem 2008; 103:1747-59. [PMID: 17891780 PMCID: PMC2778848 DOI: 10.1002/jcb.21561] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Receptor activator of NF-kappaB ligand (RANKL) is a critical osteoclastogenic factor that is expressed on bone marrow stromal/preosteoblast cells. Most bone resorption stimuli induce osteoclast formation by modulating RANKL expression in these cells. However, little is known about the mechanisms regulating RANKL gene expression. We recently reported that heat shock factor-2 (HSF-2) is a downstream target for FGF-2 signaling to enhance RANKL gene transcription in marrow stromal/preosteoblast cells. In this study, we show that DACH1 (human homologue of Drosophila dachshund gene) negatively regulates RANKL gene expression and suppresses FGF-2-enhanced RANKL gene expression in these cells. DACH1 contains a conserved dachshund domain (DS) in the N-terminal region, which interacts with the nuclear co-repressor (NCoR) to repress gene expression. Co-expression of DACH1 with hRANKL promoter-luciferase reporter plasmid in normal human bone marrow-derived stromal cells significantly decreased (3.3-fold) FGF-2-stimulated hRANKL gene promoter activity. Deletion of DS domain abolished DACH1 inhibition of FGF-2-enhanced RANKL gene promoter activity. Western blot analysis confirmed that DACH1 suppressed FGF-2-stimulated RANKL expression in marrow stromal/preosteoblast cells. We show HSF-2 co-immune precipitated with DACH1 and that FGF-2 stimulation significantly increased (2.7-fold) HSF-2 binding to DACH1. Confocal microscopy analysis further demonstrated that FGF-2 promotes HSF-2 nuclear transport and co-localization with DACH1 in marrow stromal cells. Co-expression of NCoR with DACH1 significantly decreased (5.3-fold) and siRNA suppression of NCoR in DACH1 co-transfected cells increased (3.6-fold) RANKL promoter activity. Furthermore, DACH1 co-expression with NCoR significantly decreased (7.5-fold) RANKL mRNA expression in marrow stromal cells. Collectively, these studies indicate that NCoR participates in DACH1 repression of RANKL gene expression in marrow stromal/preosteoblast cells. Thus, DACH1 plays an important role in negative regulation of RANKL gene expression in marrow stromal/preosteoblast cells in the bone microenvironment.
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Affiliation(s)
- Kumaran Sundaram
- Charles P. Darby Children's Research Institute, Medical University of South Carolina, Charleston, South Carolina
| | - Santhosh K. Mani
- Gazes Cardiac Research Institute, Medical University of South Carolina, Charleston, South Carolina
| | - Kazuyuki Kitatani
- Department of Biochemistry, Medical University of South Carolina, Charleston, South Carolina
| | - Kongming Wu
- Kimmel Cancer Center, Thomas Jefferson University, Pennsylvania
| | | | - Sakamuri V. Reddy
- Charles P. Darby Children's Research Institute, Medical University of South Carolina, Charleston, South Carolina
- Correspondence to: Sakamuri V. Reddy, PhD, Charles P. Darby Children's Research Institute, 173 Ashley Avenue, Charleston, SC 29425.
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