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Li S, Siengdee P, Hadlich F, Trakooljul N, Oster M, Reyer H, Wimmers K, Ponsuksili S. Dynamics of DNA methylation during osteogenic differentiation of porcine synovial membrane mesenchymal stem cells from two metabolically distinct breeds. Epigenetics 2024; 19:2375011. [PMID: 38956836 PMCID: PMC11225923 DOI: 10.1080/15592294.2024.2375011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 06/26/2024] [Indexed: 07/04/2024] Open
Abstract
Mesenchymal stem cells (MSCs), with the ability to differentiate into osteoblasts, adipocytes, or chondrocytes, show evidence that the donor cell's metabolic type influences the osteogenic process. Limited knowledge exists on DNA methylation changes during osteogenic differentiation and the impact of diverse donor genetic backgrounds on MSC differentiation. In this study, synovial membrane mesenchymal stem cells (SMSCs) from two pig breeds (Angeln Saddleback, AS; German Landrace, DL) with distinct metabolic phenotypes were isolated, and the methylation pattern of SMSCs during osteogenic induction was investigated. Results showed that most differentially methylated regions (DMRs) were hypomethylated in osteogenic-induced SMSC group. These DMRs were enriched with genes of different osteogenic signalling pathways at different time points including Wnt, ECM, TGFB and BMP signalling pathways. AS pigs consistently exhibited a higher number of hypermethylated DMRs than DL pigs, particularly during the peak of osteogenesis (day 21). Predicting transcription factor motifs in regions of DMRs linked to osteogenic processes and donor breeds revealed influential motifs, including KLF1, NFATC3, ZNF148, ASCL1, FOXI1, and KLF5. These findings contribute to understanding the pattern of methylation changes promoting osteogenic differentiation, emphasizing the substantial role of donor the metabolic type and epigenetic memory of different donors on SMSC differentiation.
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Affiliation(s)
- Shuaichen Li
- Institute of Genome Biology, Research Institute for Farm Animal Biology (FBN), Dummerstorf, Germany
| | - Puntita Siengdee
- Institute of Genome Biology, Research Institute for Farm Animal Biology (FBN), Dummerstorf, Germany
- Program in Applied Biological Sciences: Environmental Health, Chulabhorn Graduate Institute, 906 Kamphaeng Phet 6 Road, Lak-Si, Bangkok, Thailand
| | - Frieder Hadlich
- Institute of Genome Biology, Research Institute for Farm Animal Biology (FBN), Dummerstorf, Germany
| | - Nares Trakooljul
- Institute of Genome Biology, Research Institute for Farm Animal Biology (FBN), Dummerstorf, Germany
| | - Michael Oster
- Institute of Genome Biology, Research Institute for Farm Animal Biology (FBN), Dummerstorf, Germany
| | - Henry Reyer
- Institute of Genome Biology, Research Institute for Farm Animal Biology (FBN), Dummerstorf, Germany
| | - Klaus Wimmers
- Institute of Genome Biology, Research Institute for Farm Animal Biology (FBN), Dummerstorf, Germany
- Faculty of Agricultural and Environmental Sciences, University of Rostock, Rostock, Germany
| | - Siriluck Ponsuksili
- Institute of Genome Biology, Research Institute for Farm Animal Biology (FBN), Dummerstorf, Germany
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The Osteogenesis Imperfecta Type V Mutant BRIL/IFITM5 Promotes Transcriptional Activation of MEF2, NFATc, and NR4A in Osteoblasts. Int J Mol Sci 2022; 23:ijms23042148. [PMID: 35216266 PMCID: PMC8875491 DOI: 10.3390/ijms23042148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 02/11/2022] [Accepted: 02/12/2022] [Indexed: 11/18/2022] Open
Abstract
BRIL (bone restricted ifitm-like; also known as IFITM5) is a transmembrane protein expressed in osteoblasts. Although its role in skeletal development and homeostasis is unknown, mutations in BRIL result in rare dominant forms of osteogenesis imperfecta. The pathogenic mechanism has been proposed to be a gain-of or neomorphic function. To understand the function of BRIL and its OI type V mutant (MALEP BRIL) and whether they could activate signaling pathways in osteoblasts, we performed a luciferase reporter assay screen based on the activity of 26 transcription factors. When overexpressed in MC3T3-E1 and MLO-A5 cells, the MALEP BRIL activated the reporters dependent on MEF2, NFATc, and NR4A significantly more. Additional co-transfection experiments with MEF2C and NFATc1 and a number of their modulators (HDAC4, calcineurin, RCAN, FK506) confirmed the additive or synergistic activation of the pathways by MALEP, and suggested a coordinated regulation involving calcineurin. Endogenous levels of Nr4a members, as well as Ptgs2, were upregulated by MALEP BRIL. Y2H and co-immunoprecipitation indicated that BRIL interacted with CAML, but its contribution as the most upstream stimulator of the Ca2+-calcineurin-MEF2/NFATc cascade was not confirmed convincingly. Altogether the data presented provide the first ever readout to monitor for BRIL activity and suggest a potential gain-of-function causative effect for MALEP BRIL in OI type V, leading to perturbed signaling events and gene expression.
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Sun Y, Li J, Xie X, Gu F, Sui Z, Zhang K, Yu T. Macrophage-Osteoclast Associations: Origin, Polarization, and Subgroups. Front Immunol 2021; 12:778078. [PMID: 34925351 PMCID: PMC8672114 DOI: 10.3389/fimmu.2021.778078] [Citation(s) in RCA: 70] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 11/15/2021] [Indexed: 12/31/2022] Open
Abstract
Cellular associations in the bone microenvironment are involved in modulating the balance between bone remodeling and resorption, which is necessary for maintaining a normal bone morphology. Macrophages and osteoclasts are both vital components of the bone marrow. Macrophages can interact with osteoclasts and regulate bone metabolism by secreting a variety of cytokines, which make a significant contribution to the associations. Although, recent studies have fully explored either macrophages or osteoclasts, indicating the significance of these two types of cells. However, it is of high importance to report the latest discoveries on the relationships between these two myeloid-derived cells in the field of osteoimmunology. Therefore, this paper reviews this topic from three novel aspects of the origin, polarization, and subgroups based on the previous work, to provide a reference for future research and treatment of bone-related diseases.
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Affiliation(s)
- Yang Sun
- Department of Orthopedics, The First Hospital of Jilin University, Changchun, China
| | - Jiangbi Li
- Department of Orthopedics, The First Hospital of Jilin University, Changchun, China
| | - Xiaoping Xie
- Department of Orthopedics, The First Hospital of Jilin University, Changchun, China
| | - Feng Gu
- Department of Orthopedics, The First Hospital of Jilin University, Changchun, China
| | - Zhenjiang Sui
- Department of Orthopedics, The First Hospital of Jilin University, Changchun, China
| | - Ke Zhang
- Department of Orthopedics, The First Hospital of Jilin University, Changchun, China
| | - Tiecheng Yu
- Department of Orthopedics, The First Hospital of Jilin University, Changchun, China
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The critical role of T cells in glucocorticoid-induced osteoporosis. Cell Death Dis 2020; 12:45. [PMID: 33414409 PMCID: PMC7791068 DOI: 10.1038/s41419-020-03249-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 11/12/2020] [Accepted: 11/13/2020] [Indexed: 12/14/2022]
Abstract
Glucocorticoids (GC) are widely used clinically, despite the presence of significant side effects, including glucocorticoid-induced osteoporosis (GIOP). While GC are believed to act directly on osteoblasts and osteoclasts to promote osteoporosis, the detailed underlying molecular mechanism of GC-induced osteoporosis is still not fully elucidated. Here, we show that lymphocytes play a pivotal role in regulating GC-induced osteoporosis. We show that GIOP could not be induced in SCID mice that lack T cells, but it could be re-established by adoptive transfer of splenic T cells from wild-type mice. As expected, T cells in the periphery are greatly reduced by GC; instead, they accumulate in the bone marrow where they are protected from GC-induced apoptosis. These bone marrow T cells in GC-treated mice express high steady-state levels of NF-κB receptor activator ligand (RANKL), which promotes the formation and maturation of osteoclasts and induces osteoporosis. Taken together, these findings reveal a critical role for T cells in GIOP.
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Deciphering the potential pharmaceutical mechanism of Guzhi Zengsheng Zhitongwan on rat bone and kidney based on the "kidney governing bone" theory. J Orthop Surg Res 2020; 15:146. [PMID: 32295616 PMCID: PMC7161198 DOI: 10.1186/s13018-020-01677-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 04/08/2020] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND Guzhi Zengsheng Zhitongwan (GZZSZTW) is an effective Chinese medicinal formulation for the treatment of osteoarthritis (OA) designed according to the "kidney governing bone" theory, which has been widely used as a golden guide for treating bone and cartilage diseases in traditional Chinese medicine. The aim of this study was to explore the molecular mechanism underlying its effects on the bone and kidney. METHODS Preparation and quality control were performed as previously described. Since GZZSZTW is orally administered in the form of pills prepared in boiled water, the Chinese materia medica (CMM) mixture of this formula was extracted with distilled water by a reflux method and was then filtered through a 0.45-μm Hollow Fiber Cartridge (GE Healthcare, USA). The filtrate was freeze-dried by a Heto PowerDry LL3000 Freeze Dryer (Thermo, USA) and stored at - 80 °C. The effects of GZZSZTW on gene expression and regulation of both kidney and bone tissues were investigated using a state-of-the-art RNA-seq technology. RESULTS We demonstrated that GZZSZTW could enhance kidney function and suppress bone formation and resorption by modulating the activities of osteoblast and osteoclast, and might subsequently contribute to the inhibition of osteophyte formation during the process of OA. These effects might be achieved by the synergistic interactions of various herbs and their active components in GZZSZTW, which increased the expression levels of functional genes participating in kidney function, regulation, and repair, and then decreased the expression levels of genes involved in bone formation and resorption. Thus, our findings were consistent with the "kidney governing bone" theory, which has been widely used as a guide in clinical practice for thousands of years. CONCLUSIONS This study has deepened the current knowledge about the molecular effects of GZZSZTW on bone and kidney regulation. Furthermore, this study might be able to provide possible strategies to further prevent and treat joint diseases by using traditional Chinese medicinal formulations following the "kidney governing bone" theory.
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Hong S, Hu S, Kang Z, Liu Z, Yang W, Zhang Y, Yang D, Ruan W, Yu G, Sun L, Chen L. Identification of functional lncRNAs based on competing endogenous RNA network in osteoblast differentiation. J Cell Physiol 2019; 235:2232-2244. [PMID: 31486078 DOI: 10.1002/jcp.29132] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 08/23/2019] [Indexed: 11/10/2022]
Abstract
Adult human mesenchymal stem cells have the potential to differentiate into osteoblast, which plays crucial roles in bone regeneration and repair. Some transcriptional factors (TFs), such as BMP-2 and RUNX2, have been demonstrated to control the differentiation processes. It is important to discover more key regulators in osteoblast differentiation. Recently, some studies found long noncoding RNAs (lncRNAs) participating in osteoblast differentiation, such as MALAT1, DANCR, and ANCR. In this study, we performed a network-based computational analysis to investigate the lncRNA-messenger RNA (mRNA) crosstalks via integrating microRNA (miRNA)-RNA interactions, gene coexpression, and protein-protein interactions. First, multiple topology analyses were performed to osteoblast-differentiation-related lncRNA-mRNA network (ODLMN). Several lncRNAs with central topology structures were identified as key regulators. Results showed that these lncRNAs participated in osteoblast differentiation via phosphoinositide 3-kinase (PI3K), mitogen-activated protein kinase, and Ras signals. Previous studies have demonstrated that lncRNAs exert functions by involving in close modules. Second, after performing module searching in ODLMN, two functional modules were identified, which played crucial roles through involving in PI3K/protein kinase B, cyclic adenosine 3',5'-monophosphate, and hypoxia-inducible factor 1 pathways. Third, a subset of core lncRNA-TF crosstalks that might form feedback loops to control the biological processes in osteoblast differentiation was identified. These core lncRNA-TF feedback loops showed more TF binding affinity than other lncRNAs. All these results can help us to uncover the molecular mechanism and provide new targets for bone regeneration and repair.
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Affiliation(s)
- Shuai Hong
- Hwa Mei Hospital, University of Chinese Academy of Sciences, Beijing, China.,Key Laboratory of Intelligent Information Processing, Advanced Computer Research Center, Institute of Computing Technology, Chinese Academy of Sciences, Ningbo, China
| | - Supei Hu
- Hwa Mei Hospital, University of Chinese Academy of Sciences, Beijing, China
| | - Zhengyang Kang
- Department of Orthopedics, The Second People's Hospital of Panyu, Guangzhou, China
| | - Zhiguo Liu
- Department of Osteoarthritis Trauma, Hanzhong Central Hospital, Hanzhong, China
| | - Weibin Yang
- Department of Osteoarthritis Trauma, Hanzhong Central Hospital, Hanzhong, China
| | - Yongzhi Zhang
- Department of Osteoarthritis Trauma, Hanzhong Central Hospital, Hanzhong, China
| | - Dengfeng Yang
- Department of Osteoarthritis Trauma, Hanzhong Central Hospital, Hanzhong, China
| | - Wenhui Ruan
- Department of Osteoarthritis Trauma, Hanzhong Central Hospital, Hanzhong, China
| | - Guoyong Yu
- Department of Osteoarthritis Trauma, Hanzhong Central Hospital, Hanzhong, China
| | - Liang Sun
- Key Laboratory of Intelligent Information Processing, Advanced Computer Research Center, Institute of Computing Technology, Chinese Academy of Sciences, Ningbo, China
| | - Liang Chen
- Hwa Mei Hospital, University of Chinese Academy of Sciences, Beijing, China
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Regulation of Hedgehog signaling Offers A Novel Perspective for Bone Homeostasis Disorder Treatment. Int J Mol Sci 2019; 20:ijms20163981. [PMID: 31426273 PMCID: PMC6719140 DOI: 10.3390/ijms20163981] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2019] [Revised: 08/10/2019] [Accepted: 08/14/2019] [Indexed: 02/07/2023] Open
Abstract
The hedgehog (HH) signaling pathway is central to the regulation of bone development and homeostasis. HH signaling is not only involved in osteoblast differentiation from bone marrow mesenchymal stem cells (BM-MSCs), but also acts upstream within osteoblasts via the OPG/RANK/RANKL axis to control the expression of RANKL. HH signaling has been found to up-regulate parathyroid hormone related protein (PTHrP) expression in osteoblasts, which in turn activates its downstream targets nuclear factor of activated T cells (NFAT) and cAMP responsive element binding protein (CREB), and as a result CREB and NFAT cooperatively increase RANKL expression and osteoclastogenesis. Osteoblasts must remain in balance with osteoclasts in order to avoid excessive bone formation or resorption, thereby maintaining bone homeostasis. This review systemically summarizes the mechanisms whereby HH signaling induces osteoblast development and controls RANKL expression through PTHrP in osteoblasts. Proper targeting of HH signaling may offer a therapeutic option for treating bone homeostasis disorders.
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Linc00423 as a tumor suppressor in retroperitoneal liposarcoma via activing MAPK signaling pathway through destabilizing of NFATC3. Cell Death Dis 2019; 10:430. [PMID: 31160581 PMCID: PMC6546787 DOI: 10.1038/s41419-019-1658-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 04/08/2019] [Accepted: 05/13/2019] [Indexed: 11/08/2022]
Abstract
Unraveling the noncoding RNA expression networks governing cancer initiation and development is essential while remains largely uncompleted in retroperitoneal liposarcoma (RLS). Through RNA-seq technologies and computational biology, deregulated long noncoding RNAs (lncRNAs) are being identified and reveal that lncRNAs are implicated in serial steps of RLS development. High-throughput sequencing with computational methods for assembling the transcriptome of five paired RLS patient’s tissues. We found that long intergenic noncoding RNA 423 (linc00423) was downregulated in RLS tissues. Gain-of-function assays revealed that overexpressed linc00423 obviously inhibited RLS cell growth in vitro and in vivo. Additionally, RNA sequence, RNA-pulldown and RIP assays evidenced that linc00423 involved in MAPK signaling pathway via destabilizing of nuclear factor of activated T-cells 3 (NFATC3). Summing up, our findings demonstrated that linc00423 acted as the tumor suppressor in RLS cells through regulating the protein level of NFATC3 at a post-transcriptional level and negatively regulated the MAPK signaling pathway at a transcriptional level. Linc00423 might serve as a candidate prognostic biomarker and a target for novel therapies of RLS patients.
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Bai H, Zhu H, Yan Q, Shen X, Lu X, Wang J, Li J, Chen L. TRPV2-induced Ca 2+-calcineurin-NFAT signaling regulates differentiation of osteoclast in multiple myeloma. Cell Commun Signal 2018; 16:68. [PMID: 30326911 PMCID: PMC6191893 DOI: 10.1186/s12964-018-0280-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 10/05/2018] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Myeloma bone disease (MBD) can cause bone destruction and increase the level of Ca2+ concentration in the bone marrow microenvironment by stimulating osteoclastic differentiation. Nevertheless, the relationships between MBD and highly efficient stimuli of Ca2+ in multiple myeloma (MM) progression, and possible regulatory mechanisms are poorly defined. Here, we reported that the nonselective cation channel transient receptor potential vanilloid 2 (TRPV2) plays a functional role in Ca2+ oscillations and osteoclastogenesis. METHODS To investigate the expression of TRPV2 in MM, we analyzed publicly available MM data sets and performed immunohistochemistry in MM patients. The correlations between TRPV2 expression levels and osteoclast-related cytokines were analyzed. Fluo-4 staining and ELISA assays were used to assess the regulated function of TRPV2 in intracellular Ca2+ and cytokines. Western blotting and Chromatin immunoprecipitation (ChIP) assays were performed to explore the signaling pathway of TRPV2-induced osteoclastic differentiation. Real-time PCR, Western blotting, ELISA and tartrate-resistant acid phosphatase (TRAP) staining were performed to detect the biological effects of TRPV2 inhibitor on osteoclastogenesis. RESULTS The functional expression of TRPV2, involved in the osteolysis through gating the calcium influx, was changed in the MM cells cultured in a high Ca2+ environment. Mechanistically, TRPV2 modulates nuclear factor-κB ligand (RANKL)-dependent osteoclastic differentiation through the Ca2+-calcineurin-NFAT signaling pathway. Of clinical relevance, systemic administration with SKF96365 could attenuate the MM-induced osteoclast formation in vitro. CONCLUSIONS Our study uncovers the possible roles of TRPV2, which enhances MBD, suggesting that targeting osteocyte-MM cells interactions through blockade of TRPV2 channel may provide a promising treatment strategy in MM.
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Affiliation(s)
- Hua Bai
- Department of Hematology, First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, No. 300 Guangzhou Road, Nanjing, 210029, Jiangsu Province, China
| | - Huayuan Zhu
- Department of Hematology, First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, No. 300 Guangzhou Road, Nanjing, 210029, Jiangsu Province, China
| | - Qing Yan
- Department of Hematology, First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, No. 300 Guangzhou Road, Nanjing, 210029, Jiangsu Province, China
| | - Xuxing Shen
- Department of Hematology, First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, No. 300 Guangzhou Road, Nanjing, 210029, Jiangsu Province, China
| | - Xiupan Lu
- Department of Hematology, First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, No. 300 Guangzhou Road, Nanjing, 210029, Jiangsu Province, China
| | - Juejin Wang
- Department of Physiology, Nanjing Medical University, Nanjing, 211166, Jiangsu, China
| | - Jianyong Li
- Department of Hematology, First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, No. 300 Guangzhou Road, Nanjing, 210029, Jiangsu Province, China
| | - Lijuan Chen
- Department of Hematology, First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, No. 300 Guangzhou Road, Nanjing, 210029, Jiangsu Province, China.
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de Seabra Rodrigues Dias IR, Mok SWF, Gordillo-Martínez F, Khan I, Hsiao WWL, Law BYK, Wong VKW, Liu L. The Calcium-Induced Regulation in the Molecular and Transcriptional Circuitry of Human Inflammatory Response and Autoimmunity. Front Pharmacol 2018; 8:962. [PMID: 29358919 PMCID: PMC5766673 DOI: 10.3389/fphar.2017.00962] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 12/18/2017] [Indexed: 01/01/2023] Open
Abstract
Rheumatoid arthritis synovial fibroblasts (RASFs) are fundamental effector cells in RA driving the joint inflammation and deformities. Celastrol is a natural compound that exhibits a potent anti-arthritic effect promoting endoplasmic reticulum (ER) stress mediated by intracellular calcium (Ca2+) mobilization. Ca2+ is a second messenger regulating a variety of cellular processes. We hypothesized that the compound, celastrol, affecting cytosolic Ca2+ mobilization could serve as a novel strategy to combat RA. To address this issue, celastrol was used as a molecular tool to assay the inflammatory gene expression profile regulated by Ca2+. We confirmed that celastrol treatment mobilized cytosolic Ca2+ in patient-derived RASFs. It was found that 23 genes out of 370 were manipulated by Ca2+ mobilization using an inflammatory and autoimmunity PCR array following independent quantitative PCR validation. Most of the identified genes were downregulated and categorized into five groups corresponding to their cellular responses participating in RA pathogenesis. Accordingly, a signaling network map demonstrating the possible molecular circuitry connecting the functions of the products of these genes was generated based on literature review. In addition, a bioinformatics analysis revealed that celastrol-induced Ca2+ mobilization gene expression profile showed a novel mode of action compared with three FDA-approved rheumatic drugs (methotrexate, rituximab and tocilizumab). To the best of our knowledge, this is a pioneer work charting the Ca2+ signaling network on the regulation of RA-associated inflammatory gene expression.
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Affiliation(s)
| | - Simon W F Mok
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Macau, China
| | - Flora Gordillo-Martínez
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Macau, China
| | - Imran Khan
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Macau, China
| | - Wendy W L Hsiao
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Macau, China
| | - Betty Y K Law
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Macau, China
| | - Vincent K W Wong
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Macau, China
| | - Liang Liu
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Macau, China
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Isoproterenol Increases RANKL Expression in a ATF4/NFATc1-Dependent Manner in Mouse Osteoblastic Cells. Int J Mol Sci 2017; 18:ijms18102204. [PMID: 29053621 PMCID: PMC5666884 DOI: 10.3390/ijms18102204] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 10/16/2017] [Accepted: 10/20/2017] [Indexed: 12/12/2022] Open
Abstract
Sympathetic nervous system stimulation-induced β-adrenergic signal transduction is known to induce bone loss and increase of osteoclast activity. Although isoproterenol, a nonspecific β-adrenergic receptor agonist, has been shown to increase receptor activator of NF-κB ligand (RANKL), the details of the regulatory mechanisms remain unclear. In the present study, we investigated the role of the nuclear factor of activated T-cells (NFAT) in isoproterenol-induced RANKL expression in C2C12 and in primary cultured mouse calvarial cells. Isoproterenol increased nuclear factor of activated T-cells cytoplasmic 1 (NFATc1) and RANKL expressions at both mRNA and protein levels and increased NFAT reporter activity. NFATc1 knockdown blocked isoproterenol-mediated RANKL expression. Isoproterenol also promoted cAMP response element-binding protein 1 (CREB1) and activating transcription factor 4 (ATF4) phosphorylation. Isoproterenol-mediated transcriptional activation of NFAT was blocked by protein kinase A (PKA) inhibitor H89. Isoproterenol-induced CREB1, ATF4, NFATc1, and RANKL expressions were suppressed by H89. Mutations in cAMP response element-like or NFAT-binding element suppressed isoproterenol-induced RANKL promoter activity. Chromatin immunoprecipitation analysis demonstrated that isoproterenol increased NFAT-binding and ATF4-binding activities on the mouse RANKL promoter, but did not increase CREB1-binding activity. Association of NFATc1 and ATF4 was not observed in a co-immunoprecipitation study. ATF4 knockdown suppressed isoproterenol-induced NFAT binding to the RANKL promoter, whereas NFATc1 knockdown did not suppress isoproterenol-induced ATF4 binding to the RANKL promoter. ATF4 knockdown suppressed isoproterenol-induced expressions of NFATc1 and RANKL. These results suggest that isoproterenol increases RANKL expression in an ATF4/NFATc1-dependent manner.
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Rothammer S, Bernau M, Kremer-Rücker PV, Medugorac I, Scholz AM. Genome-wide QTL mapping results for regional DXA body composition and bone mineral density traits in pigs. Arch Anim Breed 2017. [DOI: 10.5194/aab-60-51-2017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Abstract. In a previous study, genome-wide mapping of quantitative trait loci (QTL) for five body composition traits, three bone mineral traits and live weight was performed using whole-body dual-energy X-ray absorptiometry (DXA) data. Since QTL for bone mineral traits were rare, the current study aimed to clarify whether the mapping results were influenced by the analysed body regions. Thus, the same material (551 pigs) and methods as in the whole-body QTL mapping study were used. However, for evaluation of the DXA scans, we manually defined two body regions: (i) from the last ribs to the pelvis (A) and (ii) including the pelvis and the hind limbs (P). Since live weight was not affected by the regional analysis, it was omitted from the QTL mapping design. Our results show an overall high consistency of mapping results especially for body composition traits. Two thirds of the initial whole-body QTL are significant for both A and P. Possible causes for the still low number of bone mineral QTL and the lower consistency found for these traits are discussed. For body composition traits, the data presented here show high genome-wide Pearson correlations between mapping results that are based on DXA scans with the time-saving whole-body standard setting and mapping results for DXA data that were obtained by time-consuming manual definition of the regions of interest. However, our results also suggest that whole-body or regional DXA scans might generally be less suitable for mapping of bone mineral traits in pigs. An analysis of single reference bones could be more useful.
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Park HJ, Baek K, Baek JH, Kim HR. TNFα Increases RANKL Expression via PGE₂-Induced Activation of NFATc1. Int J Mol Sci 2017; 18:ijms18030495. [PMID: 28245593 PMCID: PMC5372511 DOI: 10.3390/ijms18030495] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 02/12/2017] [Accepted: 02/20/2017] [Indexed: 01/07/2023] Open
Abstract
Tumor necrosis factor α (TNFα) is known to upregulate the expression of receptor activator of NF-κB ligand (RANKL). We investigated the role of the calcineurin/nuclear factor of activated T-cells (NFAT) signaling pathway in TNFα-induced RANKL expression in C2C12 and primary cultured mouse calvarial cells. TNFα-induced RANKL expression was blocked by the calcineurin/NFAT pathway inhibitors. TNFα increased NFAT transcriptional activity and subsequent RANKL promoter binding. Mutations in the NFAT-binding element (MT(N)) suppressed TNFα-induced RANKL promoter activity. TNFα increased prostaglandin E2 (PGE2) production, which in turn enhanced NFAT transcriptional activity and binding to the RANKL promoter. MT(N) suppressed PGE2-induced RANKL promoter activity. TNFα and PGE2 increased the expression of RANKL, NFAT cytoplasmic-1 (NFATc1), cAMP response element-binding protein (CREB), and cyclooxygenase 2 (COX2); which increment was suppressed by indomethacin, a COX inhibitor. Mutations in the CRE-like element blocked PGE2-induced RANKL promoter activity. PGE2 induced the binding of CREB to the RANKL promoter, whereas TNFα increased the binding of both CREB and NFATc1 to this promoter through a process blocked by indomethacin. The PGE2 receptor antagonists AH6809 and AH23848 blocked TNFα-induced expression of RANKL, NFATc1, and CREB; transcriptional activity of NFAT; and binding of NFATc1 or CREB to the RANKL promoter. These results suggest that TNFα-induced RANKL expression depends on PGE2 production and subsequent transcriptional activation/enhanced binding of NFATc1 and CREB to the RANKL promoter.
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Affiliation(s)
- Hyun-Jung Park
- Department of Molecular Genetics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 08826, Korea.
| | - Kyunghwa Baek
- Department of Pharmacology, College of Dentistry and Research Institute of Oral Science, Gangneung-Wonju National University, Gangwon-do 25457, Korea.
| | - Jeong-Hwa Baek
- Department of Molecular Genetics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 08826, Korea.
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Luthringer BJ, Willumeit-Römer R. Effects of magnesium degradation products on mesenchymal stem cell fate and osteoblastogenesis. Gene 2016; 575:9-20. [DOI: 10.1016/j.gene.2015.08.028] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 08/10/2015] [Accepted: 08/13/2015] [Indexed: 01/02/2023]
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Mandal CC, Das F, Ganapathy S, Harris SE, Choudhury GG, Ghosh-Choudhury N. Bone Morphogenetic Protein-2 (BMP-2) Activates NFATc1 Transcription Factor via an Autoregulatory Loop Involving Smad/Akt/Ca2+ Signaling. J Biol Chem 2015; 291:1148-61. [PMID: 26472929 DOI: 10.1074/jbc.m115.668939] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Indexed: 11/06/2022] Open
Abstract
Bone remodeling is controlled by dual actions of osteoclasts (OCs) and osteoblasts (OBs). The calcium-sensitive nuclear factor of activated T cells (NFAT) c1 transcription factor, as an OC signature gene, regulates differentiation of OCs downstream of bone morphogenetic protein-2 (BMP-2)-stimulated osteoblast-coded factors. To analyze a functional link between BMP-2 and NFATc1, we analyzed bones from OB-specific BMP-2 knock-out mice for NFATc1 expression by immunohistochemical staining and found significant reduction in NFATc1 expression. This indicated a requirement of BMP-2 for NFATc1 expression in OBs. We showed that BMP-2, via the receptor-specific Smad pathway, regulates expression of NFATc1 in OBs. Phosphatidylinositol 3-kinase/Akt signaling acting downstream of BMP-2 also drives NFATc1 expression and transcriptional activation. Under the basal condition, NFATc1 is phosphorylated. Activation of NFAT requires dephosphorylation by the calcium-dependent serine/threonine phosphatase calcineurin. We examined the role of calcium in BMP-2-stimulated regulation of NFATc1 in osteoblasts. 1,2Bis(2aminophenoxy)ethaneN,N,N',N'-tetraacetic acid acetoxymethyl ester, an inhibitor of intracellular calcium abundance, blocked BMP-2-induced transcription of NFATc1. Interestingly, BMP-2 induced calcium release from intracellular stores and increased calcineurin phosphatase activity, resulting in NFATc1 nuclear translocation. Cyclosporin A, which inhibits calcineurin upstream of NFATc1, blocked BMP-2-induced NFATc1 mRNA and protein expression. Expression of NFATc1 directly increased its transcription and VIVIT peptide, an inhibitor of NFATc1, suppressed BMP-2-stimulated NFATc1 transcription, confirming its autoregulation. Together, these data show a role of NFATc1 downstream of BMP-2 in mouse bone development and provide novel evidence for the presence of a cross-talk among Smad, phosphatidylinositol 3-kinase/Akt, and Ca(2+) signaling for BMP-2-induced NFATc1 expression through an autoregulatory loop.
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Affiliation(s)
| | | | | | - Stephen E Harris
- Periodontics, University of Texas Health Science Center, San Antonio, Texas 78229
| | - Goutam Ghosh Choudhury
- Medicine, and From Veterans Affairs Research and Geriatric Research Education and Clinical Center, South Texas Veterans Health Care System and
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Ruest LB, Ranjbaran H, Tong EJ, Svoboda KKH, Feng JQ. Activation of Receptor Activator of Nuclear Factor-κB Ligand and Matrix Metalloproteinase Production in Periodontal Fibroblasts by Endothelin Signaling. J Periodontol 2015; 87:e1-8. [PMID: 26376946 DOI: 10.1902/jop.2015.150397] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Periodontitis is a group of inflammatory diseases affecting the tissues supporting the teeth that will progressively cause the loss of alveolar bone and periodontal ligaments and eventually the dentition. Activation of osteoclast activity by receptor activator of nuclear factor-κB ligand (RANKL) and released enzymes such as matrix metalloproteinases (MMPs) are among the factors involved in the breakdown of the periodontium. However, the mechanisms regulating their production in periodontitis are poorly understood. Endothelin signaling via the activation of the endothelin-A receptor (EDNRA) by endothelin-1 may play a role in the disease because the expression of the receptor and ligand is elevated in the periodontal tissues of patients with periodontitis. METHODS Cultured primary human periodontal fibroblasts were treated with 20 and 100 nM endothelin-1 for 6 and 24 hours and then collected to assess MMP and RANKL production by immunoblotting. Inhibitors were used to identify the molecular pathways activated by EDNRA in these cells. RESULTS Endothelin-1 stimulated the production of MMP1, MMP8, and RANKL in a dose- and time-dependent manner; blocking EDNRA function with the antagonist TBC3214 inhibited the response, although EDNRA activation had no effects on osteoprotegerin production. These mechanistic studies indicate that EDNRA activates phospholipase C, which then 1) increases the MMP1 protein levels through activation of the extracellular signal-regulated kinase mitogen-activated protein kinase-dependent pathway and 2) upregulates RANKL by a different pathway. CONCLUSION These results suggest that EDNRA may function in the breakdown of the periodontal tissues associated with periodontitis by promoting the protein expression of MMPs and RANKL via the phospholipase C pathway.
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Affiliation(s)
- L Bruno Ruest
- Department of Biomedical Sciences, Texas A&M University Baylor College of Dentistry, Dallas, TX
| | - Hamid Ranjbaran
- Department of Biomedical Sciences, Texas A&M University Baylor College of Dentistry, Dallas, TX
| | - Eric J Tong
- Department of Biomedical Sciences, Texas A&M University Baylor College of Dentistry, Dallas, TX
| | - Kathy K H Svoboda
- Department of Biomedical Sciences, Texas A&M University Baylor College of Dentistry, Dallas, TX
| | - Jian Q Feng
- Department of Biomedical Sciences, Texas A&M University Baylor College of Dentistry, Dallas, TX
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Hajibeigi A, Dioum EM, Guo J, Öz OK. Identification of novel regulatory NFAT and TFII-I binding elements in the calbindin-D28k promoter in response to serum deprivation. Biochem Biophys Res Commun 2015; 465:414-420. [PMID: 26260319 DOI: 10.1016/j.bbrc.2015.08.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2015] [Accepted: 08/05/2015] [Indexed: 11/18/2022]
Abstract
Calbindin-D28k, a key regulator of calcium homeostasis plays a cytoprotective role in various tissues. We used serum free (SFM) and charcoal stripped serum (csFBS) culture media as models of cellular stress to modulate calbindin D28k expression and identify regulatory cis-elements and trans-acting factors in kidney and beta cells. The murine calbindin-D28k promoter activity was significantly upregulated under SFM or csFBS condition. Promoter analysis revealed evolutionary conserved regulatory cis-elements and deletion of 23 nt from +117/+139 as critical for basal transcription. Bioinformatics analysis of the promoter revealed conserved NFAT and TFII regulators elements. Forced expression of NFAT stimulated promoter activity. Inhibition of NFAT transcriptional activity by FK506 attenuated calbindin-D28k expression. TFII-I was shown to be necessary for basal promoter activity and to act cooperatively with NFAT. Using chromatin immunoprecipitation (ChIP) assays, NFAT was shown to bind to both proximal and distal promoter regions. ChIP assays also revealed recruitment of TFII to the -36/+139 region. Knockdown of TFII-I decreased promoter activity. In summary, calbindin-D28k expression during serum deprivation is partly regulated by NFAT and TF-II. This regulation may be important in vivo during ischemia and growth factor withdrawal to regulate cellular function and maintenance.
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Affiliation(s)
- Asghar Hajibeigi
- Department of Radiology, UT Southwestern Medical Center, Dallas, Texas 75390-9153, USA
| | - Elhadji M Dioum
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, Texas 75390-9153, USA
| | - Jianfei Guo
- Department of Radiology, UT Southwestern Medical Center, Dallas, Texas 75390-9153, USA
| | - Orhan K Öz
- Department of Radiology, UT Southwestern Medical Center, Dallas, Texas 75390-9153, USA
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Park HJ, Baek K, Baek JH, Kim HR. The cooperation of CREB and NFAT is required for PTHrP-induced RANKL expression in mouse osteoblastic cells. J Cell Physiol 2015; 230:667-79. [PMID: 25187507 DOI: 10.1002/jcp.24790] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Accepted: 08/29/2014] [Indexed: 11/11/2022]
Abstract
Parathyroid hormone-related protein (PTHrP) is known to induce the expression of receptor activator of NF-κB ligand (RANKL) in stromal cells/osteoblasts. However, the signaling pathways involved remain controversial. In the present study, we investigated the role of cAMP/protein kinase A (PKA) and calcineurin/NFAT pathways in PTHrP-induced RANKL expression in C2C12 and primary cultured mouse calvarial cells. PTHrP-mediated induction of RANKL expression was significantly inhibited by H89 and FK506, an inhibitor of PKA and calcineurin, respectively. PTHrP upregulated CREB phosphorylation and the transcriptional activity of NFAT. Knockdown of CREB or NFATc1 blocked PTHrP-induced RANKL expression. PTHrP increased the activity of the RANKL promoter reporter that contains approximately 2 kb mouse RANKL promoter DNA sequences. Insertions of mutations in CRE-like element or in NFAT-binding element abrogated PTHrP-induced RANKL promoter activity. Chromatin immunoprecipitation assays showed that PTHrP increased the binding of CREB and NFATc1/NFATc3 to their cognate binding elements in the RANKL promoter. Inhibition of cAMP/PKA and its downstream ERK activity suppressed PTHrP-induced expression and transcriptional activity of NFATc1. CREB knockdown prevented PTHrP induction of NFATc1 expression. Furthermore, NFATc1 and CREB were co-immunoprecipitated. Mutations in CRE-like element completely blocked NFATc1-induced transactivation of the RANKL promoter reporter; however, mutations in NFAT-binding element partially suppressed CREB-induced RANKL promoter activity. Overexpression of CREB increased NFATc1 binding to the RANKL promoter and vice versa. These results suggest that PTHrP-induced RANKL expression depends on the activation of both cAMP/PKA and calcineurin/NFAT pathways, and subsequently, CREB and NFAT cooperate to transactivate the mouse RANKL gene.
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Affiliation(s)
- Hyun-Jung Park
- Department of Molecular Genetics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, Korea
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Sundaram K, Sambandam Y, Balasubramanian S, Pillai B, Voelkel-Johnson C, Ries WL, Reddy SV. STAT-6 mediates TRAIL induced RANK ligand expression in stromal/preosteoblast cells. Bone 2015; 71:137-44. [PMID: 25445452 DOI: 10.1016/j.bone.2014.10.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 10/14/2014] [Accepted: 10/23/2014] [Indexed: 02/02/2023]
Abstract
Receptor activator of nuclear factor kappa-B ligand (RANKL) is a critical osteoclastogenic factor expressed in bone marrow stromal/osteoblast lineage cells. Tumor necrosis factor (TNF) related apoptosis-inducing ligand (TRAIL) levels are elevated in pathologic conditions such as multiple myeloma and inflammatory arthritis, and have been positively correlated with osteolytic markers. Osteoprotegerin (OPG) which inhibits osteoclastogenesis is a decoy receptor for RANKL and also known to interact with TRAIL. Herein, we show that TRAIL increases DR5 and DcR1 receptors but no change in the levels of DR4 and DcR2 expression in human bone marrow derived stromal/preosteoblast (SAKA-T) cell line. We further demonstrated that TRAIL treatment significantly decreased OPG mRNA expression. Interestingly, TRAIL treatment induced RANKL mRNA expression in these cells. In addition, TRAIL significantly increased NF-kB and c-Jun N-terminal kinase (JNK) activity. Human transcription factor array screening by real-time RT-PCR identified TRAIL up-regulation of the signal transducers and activators of the transcription (STAT)-6 expression in SAKA-T cells. TRAIL stimulation induced p-STAT-6 expression in human bone marrow derived primary stromal/preosteoblast cells. Confocal microscopy analysis further revealed p-STAT-6 nuclear localization in SAKA-T cells. Chromatin immunoprecipitation (ChIP) assay confirmed p-STAT-6 binding to the hRANKL gene distal promoter region. In addition, siRNA suppression of STAT-6 expression inhibits TRAIL increased hRANKL gene promoter activity. Thus, our results suggest that TRAIL induces RANKL expression through a STAT-6 dependent transcriptional regulatory mechanism in bone marrow stromal/preosteoblast cells.
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Affiliation(s)
- Kumaran Sundaram
- Charles P. Darby Children's Research Institute, Medical University of South Carolina, Charleston, SC, USA
| | - Yuvaraj Sambandam
- Charles P. Darby Children's Research Institute, Medical University of South Carolina, Charleston, SC, USA
| | | | - Balakrishnan Pillai
- Charles P. Darby Children's Research Institute, Medical University of South Carolina, Charleston, SC, USA
| | | | - William L Ries
- College of Dental Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - Sakamuri V Reddy
- Charles P. Darby Children's Research Institute, Medical University of South Carolina, Charleston, SC, USA.
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Hu F, Pan L, Zhang K, Xing F, Wang X, Lee I, Zhang X, Xu J. Elevation of extracellular Ca2+ induces store-operated calcium entry via calcium-sensing receptors: a pathway contributes to the proliferation of osteoblasts. PLoS One 2014; 9:e107217. [PMID: 25254954 PMCID: PMC4177836 DOI: 10.1371/journal.pone.0107217] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Accepted: 08/10/2014] [Indexed: 01/05/2023] Open
Abstract
Aims The local concentration of extracellular Ca2+ ([Ca2+]o) in bone microenvironment is accumulated during bone remodeling. In the present study we investigated whether elevating [Ca2+]o induced store-operated calcium entry (SOCE) in primary rat calvarial osteoblasts and further examined the contribution of elevating [Ca2+]o to osteoblastic proliferation. Methods Cytosolic Ca2+ concentration ([Ca2+]c) of primary cultured rat osteoblasts was detected by fluorescence imaging using calcium-sensitive probe fura-2/AM. Osteoblastic proliferation was estimated by cell counting, MTS assay and ATP assay. Agonists and antagonists of calcium-sensing receptors (CaSR) as well as inhibitors of phospholipase C (PLC), SOCE and voltage-gated calcium (Cav) channels were applied to study the mechanism in detail. Results Our data showed that elevating [Ca2+]o evoked a sustained increase of [Ca2+]c in a dose-dependent manner. This [Ca2+]c increase was blocked by TMB-8 (Ca2+ release inhibitor), 2-APB and BTP-2 (both SOCE blockers), respectively, whereas not affected by Cav channels blockers nifedipine and verapamil. Furthermore, NPS2143 (a CaSR antagonist) or U73122 (a PLC inhibitor) strongly reduced the [Ca2+]o-induced [Ca2+]c increase. The similar responses were observed when cells were stimulated with CaSR agonist spermine. These data indicated that elevating [Ca2+]o resulted in SOCE depending on the activation of CaSR and PLC in osteoblasts. In addition, high [Ca2+]o significantly promoted osteoblastic proliferation, which was notably reversed by BAPTA-AM (an intracellular calcium chelator), 2-APB, BTP-2, TMB-8, NPS2143 and U73122, respectively, but not affected by Cav channels antagonists. Conclusions Elevating [Ca2+]o induced SOCE by triggering the activation of CaSR and PLC. This process was involved in osteoblastic proliferation induced by high level of extracellular Ca2+ concentration.
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Affiliation(s)
- Fen Hu
- The Key Laboratory of Weak-Light Nonlinear Photonics, Ministry of Education, TEDA Applied Physics Institute and School of Physics, Nankai University, Tianjin, China
| | - Leiting Pan
- The Key Laboratory of Weak-Light Nonlinear Photonics, Ministry of Education, TEDA Applied Physics Institute and School of Physics, Nankai University, Tianjin, China
- * E-mail: (LP); (JX)
| | - Kai Zhang
- The Key Laboratory of Weak-Light Nonlinear Photonics, Ministry of Education, TEDA Applied Physics Institute and School of Physics, Nankai University, Tianjin, China
| | - Fulin Xing
- The Key Laboratory of Weak-Light Nonlinear Photonics, Ministry of Education, TEDA Applied Physics Institute and School of Physics, Nankai University, Tianjin, China
| | - Xinyu Wang
- The Key Laboratory of Weak-Light Nonlinear Photonics, Ministry of Education, TEDA Applied Physics Institute and School of Physics, Nankai University, Tianjin, China
| | - Imshik Lee
- The Key Laboratory of Weak-Light Nonlinear Photonics, Ministry of Education, TEDA Applied Physics Institute and School of Physics, Nankai University, Tianjin, China
| | - Xinzheng Zhang
- The Key Laboratory of Weak-Light Nonlinear Photonics, Ministry of Education, TEDA Applied Physics Institute and School of Physics, Nankai University, Tianjin, China
| | - Jingjun Xu
- The Key Laboratory of Weak-Light Nonlinear Photonics, Ministry of Education, TEDA Applied Physics Institute and School of Physics, Nankai University, Tianjin, China
- * E-mail: (LP); (JX)
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Lee HL, Park HJ, Kwon A, Baek K, Woo KM, Ryoo HM, Kim GS, Baek JH. Smurf1 plays a role in EGF inhibition of BMP2-induced osteogenic differentiation. Exp Cell Res 2014; 323:276-87. [DOI: 10.1016/j.yexcr.2014.03.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 01/30/2014] [Accepted: 03/03/2014] [Indexed: 12/13/2022]
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Weissinger D, Tagscherer KE, Macher-Göppinger S, Haferkamp A, Wagener N, Roth W. The soluble Decoy Receptor 3 is regulated by a PI3K-dependent mechanism and promotes migration and invasion in renal cell carcinoma. Mol Cancer 2013; 12:120. [PMID: 24107265 PMCID: PMC3852559 DOI: 10.1186/1476-4598-12-120] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 10/04/2013] [Indexed: 01/04/2023] Open
Abstract
Background Overexpression of Decoy Receptor 3 (DcR3), a soluble member of the tumor necrosis factor receptor superfamily, is a common event in several types of cancer. In renal cell carcinoma (RCC), DcR3 overexpression is associated with lymph node and distant metastasis as well as a poor prognosis. However, the functional role and regulation of DcR3 expression in RCC is so far unknown. Methods Modulation of DcR3 expression by siRNA and ectopic gene expression, respectively, was performed in ACHN and 769-P RCC cell lines. Functional effects of a modulated DcR3 expression were analyzed with regard to migration, invasion, adhesion, clonogenicity, and proliferation. Furthermore, quantitative RT-PCR and immunoblot analyses were performed to evaluate the expression of downstream mediators of DcR3. In further experiments, luciferase assays, quantitative RT-PCR and immunoblot analyses were applied to study the regulation of DcR3 expression in RCC. Additionally, an ex vivo tissue slice culture technique combined with immunohistochemistry was used to study the regulation of DcR3 expression in human RCC specimens. Results Here, we show that DcR3 promotes adhesion, migration and invasiveness of RCC cells. The DcR3-dependent increase in cellular invasiveness is accompanied with an up-regulation of integrin alpha 4, matrixmetalloproteinase 7 and urokinase plasminogen activator (uPA). Further, we identified a signaling pathway regulating DcR3 expression in RCC. Using in vitro experiments as well as an ex vivo RCC tissue slice culture model, we demonstrate that expression of DcR3 is regulated in a PI3K/AKT-dependent manner involving the transcription factor nuclear factor of activated T-cells (NFAT). Conclusions Taken together, our results identify DcR3 as a key driver of tumor cell dissemination and suggest DcR3 as a promising target for rational therapy of RCC.
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Affiliation(s)
- Daniel Weissinger
- Molecular Tumor-Pathology, German Cancer Research Center (DKFZ), Heidelberg 69120, Germany.
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Horikiri Y, Shimo T, Kurio N, Okui T, Matsumoto K, Iwamoto M, Sasaki A. Sonic hedgehog regulates osteoblast function by focal adhesion kinase signaling in the process of fracture healing. PLoS One 2013; 8:e76785. [PMID: 24124594 PMCID: PMC3790742 DOI: 10.1371/journal.pone.0076785] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2013] [Accepted: 09/03/2013] [Indexed: 02/01/2023] Open
Abstract
Several biological studies have indicated that hedgehog signaling plays an important role in osteoblast proliferation and differentiation, and sonic hedgehog (SHH) expression is positively correlated with phosphorylated focal adhesion kinase (FAK) Tyr(397). However, the relationship between them and their role in the process of normal fracture repair has not been clarified yet. Immunohistochemical analysis revealed that SHH and pFAK Tyr(397) were expressed in bone marrow cells and that pFAK Tyr(397) was also detected in ALP-positive osteoblasts near the TRAP-positive osteoclasts in the fracture site in the ribs of mice on day 5 after fracture. SHH and pFAK Tyr(397) were detectable in osteoblasts near the hypertrophic chondrocytes on day 14. In vitro analysis showed that SHH up-regulated the expression of FAK mRNA and pFAK Tyr(397) time dependently in osteoblastic MC3T3-E1 cells. Functional analysis revealed that 5 lentivirus encoding short hairpin FAK RNAs (shFAK)-infected MC3T3-E1 cell groups displayed a round morphology and decreased proliferation, adhesion, migration, and differentiation. SHH stimulated the proliferation and differentiation of MC3T3-E1 cells, but had no effect on the shFAK-infected cells. SHH also stimulated osteoclast formation in a co-culture system containing MC3T3-E1 and murine CD11b(+) bone marrow cells, but did not affect the shFAK-infected MC3T3-E1 co-culture group. These data suggest that SHH signaling was activated in osteoblasts at the dynamic remodeling site of a bone fracture and regulated their proliferation and differentiation, as well as osteoclast formation, via FAK signaling.
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Affiliation(s)
- Yuu Horikiri
- Department of Oral and Maxillofacial Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
| | - Tsuyoshi Shimo
- Department of Oral and Maxillofacial Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
- * E-mail:
| | - Naito Kurio
- Department of Oral and Maxillofacial Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
| | - Tatsuo Okui
- Department of Oral and Maxillofacial Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
| | - Kenichi Matsumoto
- Department of Oral and Maxillofacial Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
| | - Masahiro Iwamoto
- Division of Orthopedic Surgery, the Children’s Hospital of Philadelphia Research Institute, Philadelphia, Pennsylvania, United States of America
| | - Akira Sasaki
- Department of Oral and Maxillofacial Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
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Mazière C, Salle V, Gomila C, Mazière JC. Oxidized low density lipoprotein enhanced RANKL expression in human osteoblast-like cells. Involvement of ERK, NFkappaB and NFAT. Biochim Biophys Acta Mol Basis Dis 2013; 1832:1756-64. [PMID: 23756197 DOI: 10.1016/j.bbadis.2013.05.033] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 04/29/2013] [Accepted: 05/31/2013] [Indexed: 10/26/2022]
Abstract
BACKGROUND Receptor activator of nuclear factor kappa-light-chain-enhancer of activated B cell ligand/osteoprotegerin ratio is of crucial importance in osteoclast differentiation and thus in bone dysregulation diseases. METHODS Receptor activator of nuclear factor kappa-light-chain-enhancer of activated B cell ligand and osteoprotegerin were determined under oxidized low density lipoprotein treatment of human osteoblast-like cells. The involvement of oxidative stress, of the extracellular signal regulated kinase and of the transcription factors nuclear factor kappa-light-chain-enhancer of activated B cells and nuclear factor of activated T cells was demonstrated. RESULTS Cu(2+)-oxidized low density lipoprotein increased cell-associated and extracellular receptor activator of nuclear factor kappa-light-chain-enhancer of activated B cell ligand levels whereas osteoprotegerin levels were not affected. The increase in receptor activator of nuclear factor kappa-light-chain-enhancer of activated B cell ligand was parallel to the generation of reactive oxygen species provoked by Cu(2+)-oxidized low density lipoprotein. The lipid extract of Cu(2+)-oxidized low density lipoprotein, together with other forms of oxidized low density lipoproteins such as smooth muscle cell-oxidized low density lipoprotein and myeloperoxidase-oxidized low density lipoprotein, also induced an increase in reactive oxygen species and cell-associated receptor activator of nuclear factor kappa-light-chain-enhancer of activated B cell ligand. The effect of Cu(2+)-oxidized low density lipoprotein was prevented by the antioxidant vitamin E, and mimicked by the prooxidant compounds hydrogen peroxide and buthionine sulfoximine. Inhibitors of mitogen activated protein kinase/extracellular signal regulated kinase (PD 98059), nuclear factor kappa-light-chain-enhancer of activated B cells (Ro 106-9920) and nuclear factor of activated T cells (Vivit) reduced the effect of Cu(2+)-oxidized low density lipoprotein on receptor activator of nuclear factor kappa-light-chain-enhancer of activated B cell ligand expression. Cu(2+)-oxidized low density lipoprotein signaling was also reduced by vitamin E. GENERAL SIGNIFICANCE This work describes a new molecular mechanism and elucidates the signaling pathway whereby oxidized low density lipoprotein, by means of its lipid moiety, can modulate the crosstalk between osteoblasts/osteoclasts and bone remodeling, leading to an eventual risk of osteoporosis.
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Walsh NC, Alexander KA, Manning CA, Karmakar S, Karmakar SK, Wang JF, Weyand CM, Pettit AR, Gravallese EM. Activated human T cells express alternative mRNA transcripts encoding a secreted form of RANKL. Genes Immun 2013; 14:336-45. [PMID: 23698708 PMCID: PMC3740552 DOI: 10.1038/gene.2013.29] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2012] [Revised: 04/02/2013] [Accepted: 04/16/2013] [Indexed: 12/02/2022]
Abstract
Receptor activator of nuclear factor-kappaB -ligand (RANKL), encoded by the gene TNFSF11, is required for osteoclastogenesis, and its expression is upregulated in pathologic bone loss. Transcript variants of TNFSF11 mRNA have been described that encode a membrane-bound and a putative secreted form of RANKL. We identify a TNFSF11 transcript variant that extends the originally identified transcript encoding secreted RANKL. We demonstrate that this TNFSF11 transcript variant is expressed by the human osteosarcoma cell line, Saos-2, and by both primary human T cells and Jurkat T cells. Of relevance to the production of RANKL in pathologic bone loss, expression of this secreted TNFSF11 transcript is upregulated in Jurkat T cells and primary human T cells upon activation. Furthermore, this transcript can be translated and secreted in Jurkat T cells in vitro and is able to support osteoclast differentiation. Our data highlight the complexity of the TNFSF11 genomic locus and demonstrate the potential for the expression of alternate mRNA transcripts encoding membrane-bound and secreted forms of RANKL. Implications of alternate mRNA transcripts encoding different RANKL protein isoforms should be carefully considered and specifically examined in future studies, particularly those implicating RANKL in pathologic bone loss.
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Affiliation(s)
- N C Walsh
- St Vincent's Institute of Medical Research, Melbourne, Victoria, Australia
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26
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Lee HL, Yi T, Baek K, Kwon A, Hwang HR, Qadir AS, Park HJ, Woo KM, Ryoo HM, Kim GS, Baek JH. Tumor necrosis factor-α enhances the transcription of Smad ubiquitination regulatory factor 1 in an activating protein-1- and Runx2-dependent manner. J Cell Physiol 2013; 228:1076-86. [PMID: 23042144 DOI: 10.1002/jcp.24256] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Accepted: 09/27/2012] [Indexed: 11/09/2022]
Abstract
Smad ubiquitination regulatory factor 1 (Smurf1) is an E3 ubiquitin ligase that negatively regulates osteoblast differentiation. Although tumor necrosis factor-α (TNF-α) has been shown to increase Smurf1 expression, the details of the regulatory mechanisms remain unclear. Here, we investigated the molecular mechanism by which TNF-α stimulates Smurf1 expression in C2C12 and primary cultured mouse calvarial cells. TNF-α treatment rapidly induced the activation of NF-κB and MAPKs. Smurf1 induction by TNF-α was blocked by the inhibition of JNK or ERK, while the inhibition of NF-κB and p38 MAPK had no effect on Smurf1 induction. TNF-α treatment or c-Jun overexpression enhanced the activity of a luciferase reporter that contained a 2.7 kb mouse Smurf1 promoter sequence. Site-directed mutagenesis of the Smurf1 reporter and chromatin immunoprecipitation analysis demonstrated that the activating protein-1 (AP-1) binding motif at -922 bp on the mouse Smurf1 promoter mediated TNF-α/JNK/AP-1-stimulated Smurf1 transcription. Interestingly, Smurf1 expression was not observed in Runx2-null mouse calvarial cells. When Runx2 was ectopically expressed in these cells, the basal and TNF-α-induced expression of Smurf1 was restored. Overexpression of Runx2 transactivated the Smurf1 promoter in a dose-dependent manner. Reporter and chromatin immunoprecipitation assays demonstrated that the Runx2-binding motif at -202 bp functioned in Runx2-mediated Smurf1 expression. ERK activation by TNF-α treatment or constitutively active MEK1 overexpression increased Smurf1 expression in a Runx2-dependent manner. These results suggest that the JNK/AP-1 and ERK/Runx2 signaling pathways mediate TNF-α-dependent Smurf1 transcription.
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Affiliation(s)
- Hye-Lim Lee
- Department of Molecular Genetics, School of Dentistry, Dental Research Institute, Seoul National University, Seoul, Korea
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27
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Gabusi E, Manferdini C, Grassi F, Piacentini A, Cattini L, Filardo G, Lambertini E, Piva R, Zini N, Facchini A, Lisignoli G. Extracellular calcium chronically induced human osteoblasts effects: specific modulation of osteocalcin and collagen type XV. J Cell Physiol 2012; 227:3151-61. [PMID: 22034088 DOI: 10.1002/jcp.24001] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Fluctuation in extracellular calcium (Ca(2+)) concentration occurs during bone remodeling. Free ionized Ca(2+) plays a critical role in regulating osteoblast functions. We analyzed the effects of different concentrations of free ionized Ca(2+) (0.5, 1.3, and 2.6 mM) on human osteoblasts and we evaluated osteoblastic phenotype (marker expression and cell morphology) and functions (osteogenic differentiation, cell proliferation, and cell signaling). Our data show human osteoblasts that chronically stimulated with 0.5, 1.3, or 2.6 mM Ca(2+) significantly increase intracellular content of alkaline phosphatase, collagen type I, osteocalcin, and bone sialoprotein, whereas collagen type XV was down-modulated and RUNX2 expression was not affected. We also found a Ca(2+) concentration-dependent increase in osteogenic differentiation and cell proliferation, associated to an increase of signaling protein PLCβ1 and p-ERK. Human osteoblast morphology was affected by Ca(2+) as seen by the presence of numerous nucleoli, cells in mitosis, cell junctions, and an increased number of vacuoles. In conclusion, our data show a clear phenotypical and functional effect of extracellular Ca(2+) on human osteoblasts and support the hypothesis of a direct role of this cation in the bone remodeling processes.
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Affiliation(s)
- Elena Gabusi
- Laboratorio RAMSES, Istituto Ortopedico Rizzoli, Bologna, Italy
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Kwon A, Park HJ, Baek K, Lee HL, Park JC, Woo KM, Ryoo HM, Baek JH. Suberoylanilide hydroxamic acid enhances odontoblast differentiation. J Dent Res 2012; 91:506-12. [PMID: 22447851 DOI: 10.1177/0022034512443367] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Previous studies have shown that histone deacetylase (HDAC) inhibitors stimulate osteoblast differentiation in vitro and bone formation in vivo. However, the effects of HDAC inhibitors on odontoblasts have not been elucidated. Therefore, in this study, we examined the effect of suberoylanilide hydroxamic acid (SAHA), an HDAC inhibitor, on odontoblast differentiation using an MDPC23 odontoblast-like cell line. SAHA significantly enhanced matrix mineralization and the expression levels of odontoblast marker genes. SAHA increased the expression levels of nuclear factor I/C (Nfic) and dentin sialophosphoprotein (Dspp). Nfic bound directly to the Dspp promoter and stimulated Dspp transcription. SAHA increased both basal and Nfic-induced Dspp promoter activity. SAHA-induced Dspp promoter activity disappeared when mutations were introduced within the Nfic binding element of the Dspp promoter. Nfic knockdown by siRNA blocked SAHA stimulation of Dspp expression. These results indicate that SAHA enhances odontoblast differentiation and that SAHA increases Dspp expression, at least in part, by increasing the expression level of Nfic.
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Affiliation(s)
- A Kwon
- Department of Molecular Genetics, School of Dentistry and Dental Research Institute, Seoul National University, 28 Yeongun-dong, Jongno-gu, Seoul 110-749, Republic of Korea
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29
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Bougas K, Stenport VF, Currie F, Wennerberg A. Laminin Coating Promotes Calcium Phosphate Precipitation on Titanium Discs in vitro. EJOURNAL OF ORAL MAXILLOFACIAL RESEARCH 2012; 2:e5. [PMID: 24422002 PMCID: PMC3886082 DOI: 10.5037/jomr.2011.2405] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Accepted: 09/16/2011] [Indexed: 01/01/2023]
Abstract
Objectives The objective of this study was to investigate the effect of a laminin
coating on calcium phosphate precipitation on three potentially bioactive
titanium surfaces in simulated body fluid. Material and Methods Blasted titanium discs were prepared by alkali and heat treatment (AH),
anodic oxidation (AO) or hydroxyapatite coating (HA) and subsequently coated
with laminin. A laminin coated blasted surface (B) served as a positive
control while a blasted non coated (B-) served as a negative control.
Surface morphology was examined by Scanning Electron Microscopy (SEM). The
analysis of the precipitated calcium and phosphorous was performed by Energy
Dispersive X-ray Spectroscopy (EDX). Results The thickness of the laminin coating was estimated at 26 Å by ellipsometry.
Interferometry revealed that the coating process did not affect any of the
tested topographical parameters on µm level when comparing B to B-. After 2
weeks of incubation in SBF, the alkali-heat treated discs displayed the
highest calcium phosphate deposition and the B group showed higher levels of
calcium phosphate than the B- group. Conclusions Our results suggest that laminin may have the potential to be used as a
coating agent in order to enhance the osseoinductive performance of
biomaterial surfaces, with the protein molecules possibly functioning as
nucleation centres for apatite formation. Nevertheless, in vivo studies are
required in order to clarify the longevity of the coating and its
performance in the complex biological environment.
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Affiliation(s)
- Kostas Bougas
- Department of Prosthodontics, Faculty of Odontology, Malmö University Malmö Sweden. ; Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg Gothenburg Sweden
| | - Victoria Franke Stenport
- Department of Prosthodontics, Faculty of Odontology, Sahlgrenska Academy, University of Gothenburg Gothenburg Sweden. ; Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg Gothenburg Sweden
| | | | - Ann Wennerberg
- Department of Prosthodontics, Faculty of Odontology, Malmö University Malmö Sweden. ; Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg Gothenburg Sweden
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30
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Bougas K, Stenport VF, Currie F, Wennerberg A. In vitro Evaluation of Calcium Phosphate Precipitation on Possibly Bioactive Titanium Surfaces in the Presence of Laminin. J Oral Maxillofac Res 2011; 2:e3. [PMID: 24421995 PMCID: PMC3886075 DOI: 10.5037/jomr.2011.2303] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2011] [Accepted: 07/19/2011] [Indexed: 11/30/2022]
Abstract
Objectives The aim of the present study was to evaluate calcium phosphate precipitation
and the amount of precipitated protein on three potentially bioactive
surfaces when adding laminin in simulated body fluid. Material and Methods Blasted titanium discs were prepared by three different techniques claimed to
provide bioactivity: alkali and heat treatment (AH), anodic oxidation (AO)
or hydroxyapatite coating (HA). A blasted surface incubated in
laminin-containing simulated body fuid served as a positive control (B)
while a blasted surface incubated in non laminin-containing simulated body
fuid served as a negative control (B-). The immersion time was 1 hour, 24
hours, 72 hours and 1 week. Surface topography was investigated by
interferometry and morphology by Scanning Electron Microscopy (SEM).
Analysis of the precipitated calcium and phosphorous was performed by Energy
Dispersive X-ray Spectroscopy (EDX) and the adsorbed laminin was quantified
by iodine (125I) labeling. Results SEM demonstrated that all specimens except for the negative control were
totally covered with calcium phosphate (CaP) after 1 week. EDX revealed that
B- demonstrated lower sum of Ca and P levels compared to the other groups
after 1 week. Iodine labeling demonstrated that laminin precipitated in a
similar manner on the possibly bioactive surfaces as on the positive control
surface. Conclusions Our results indicate that laminin precipitates equally on all tested titanium
surfaces and may function as a nucleation center thus locally elevating the
calcium concentration. Nevertheless further studies are required to clarify
the role of laminin in the interaction of biomaterials with the host bone
tissue.
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Affiliation(s)
- Kostas Bougas
- Department of Prosthodontics, Faculty of Odontology, Malmö University Malmö Sweden. ; Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg Gothenburg Sweden
| | - Victoria Franke Stenport
- Department of Prosthodontics, Faculty of Odontology, Sahlgrenska Academy, University of Gothenburg Gothenburg Sweden. ; Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg Gothenburg Sweden
| | | | - Ann Wennerberg
- Department of Prosthodontics, Faculty of Odontology, Malmö University Malmö Sweden. ; Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg Gothenburg Sweden
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