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Xiao Y, Xie X, Chen Z, Yin G, Kong W, Zhou J. Advances in the roles of ATF4 in osteoporosis. Biomed Pharmacother 2023; 169:115864. [PMID: 37948991 DOI: 10.1016/j.biopha.2023.115864] [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: 09/07/2023] [Revised: 11/01/2023] [Accepted: 11/07/2023] [Indexed: 11/12/2023] Open
Abstract
Osteoporosis (OP) is characterized by reduced bone mass, decreased strength, and enhanced bone fragility fracture risk. Activating transcription factor 4 (ATF4) plays a role in cell differentiation, proliferation, apoptosis, redox balance, amino acid uptake, and glycolipid metabolism. ATF4 induces the differentiation of bone marrow mesenchymal stem cells (BM-MSCs) into osteoblasts, increases osteoblast activity, and inhibits osteoclast formation, promoting bone formation and remodeling. In addition, ATF4 mediates the energy metabolism in osteoblasts and promotes angiogenesis. ATF4 is also involved in the mediation of adipogenesis. ATF4 can selectively accumulate in osteoblasts. ATF4 can directly interact with RUNT-related transcription factor 2 (RUNX2) and up-regulate the expression of osteocalcin (OCN) and osterix (Osx). Several upstream factors, such as Wnt/β-catenin and BMP2/Smad signaling pathways, have been involved in ATF4-mediated osteoblast differentiation. ATF4 promotes osteoclastogenesis by mediating the receptor activator of nuclear factor κ-B (NF-κB) ligand (RANKL) signaling. Several agents, such as parathyroid (PTH), melatonin, and natural compounds, have been reported to regulate ATF4 expression and mediate bone metabolism. In this review, we comprehensively discuss the biological activities of ATF4 in maintaining bone homeostasis and inhibiting OP development. ATF4 has become a therapeutic target for OP treatment.
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Affiliation(s)
- Yaosheng Xiao
- Department of Orthopaetics, First Affiliated Hospital of Gannan Medical University, Ganzhou 341000, China
| | - Xunlu Xie
- Department of Pathology, Ganzhou People's Hospital, Ganzhou 341000, China
| | - Zhixi Chen
- Department of Pharmacy, Gannan Medical University, Ganzhou 341000, China
| | - Guoqiang Yin
- Ganzhou Hospital Affiliated to Nanchang University, Ganzhou 341000, China
| | - Weihao Kong
- Department of Joint Surgery, Ganzhou People's Hospital, Ganzhou 341000, China
| | - Jianguo Zhou
- Department of Joint Surgery, Ganzhou People's Hospital, Ganzhou 341000, China.
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Autophagy Regulates Osteogenic Differentiation of Human Periodontal Ligament Stem Cells Induced by Orthodontic Tension. Stem Cells Int 2022; 2022:2983862. [PMID: 36248255 PMCID: PMC9553533 DOI: 10.1155/2022/2983862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 08/24/2022] [Accepted: 09/19/2022] [Indexed: 11/18/2022] Open
Abstract
Tooth movement is the core of orthodontics. Osteogenesis of the tension side under orthodontic force has great significance on tooth movement and stability, which involves complex mechanical and biological signal transduction. However, the mechanism remains unclear. Through in vitro cell studies, we observed the increased expression levels of osteogenesis-related factors and autophagy-related factors during the osteogenic differentiation of mesenchymal stem cells induced by orthodontic force. The change trend of autophagy-related factors and osteogenesis-related factors is similar, which indicates the involvement of autophagy in osteogenesis. In the study of autophagy-related gene ATG7 silenced cells, the expression level of autophagy was significantly inhibited, and the expression level of osteogenesis-related factors also decreased accordingly. Through drug regulation, we observed that the increase of autophagy level could effectively promote osteogenic differentiation, while the decrease of the autophagy level inhibited this process to some extent. Therefore, autophagy plays an important role in the osteogenic differentiation of mesenchymal stem cells induced by orthodontic force, which provides a novel idea useful for orthodontic treatment in promoting periodontal tissue remodeling and accelerating tooth movement.
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Mechanical force-sensitive lncRNA SNHG8 inhibits osteogenic differentiation by regulating EZH2 in hPDLSCs. Cell Signal 2022; 93:110285. [DOI: 10.1016/j.cellsig.2022.110285] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Revised: 02/12/2022] [Accepted: 02/17/2022] [Indexed: 12/18/2022]
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Nottmeier C, Decker MG, Luther J, von Kroge S, Kahl-Nieke B, Amling M, Schinke T, Petersen J, Koehne T. Accelerated tooth movement in Rsk2-deficient mice with impaired cementum formation. Int J Oral Sci 2020; 12:35. [PMID: 33353934 PMCID: PMC7755898 DOI: 10.1038/s41368-020-00102-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 10/08/2020] [Accepted: 11/04/2020] [Indexed: 12/03/2022] Open
Abstract
Coffin–Lowry–Syndrome (CLS) is a X-linked mental retardation characterized by skeletal dysplasia and premature tooth loss. We and others have previously demonstrated that the ribosomal S6 kinase RSK2, mutated in CLS, is essential for bone and cementum formation; however, it remains to be established whether RSK2 plays also a role in mechanically induced bone remodeling during orthodontic tooth movement (OTM). We, therefore, performed OTM in wild-type (WT) mice and Rsk2-deficient mice using Nitinol tension springs that were fixed between the upper left molars and the incisors. The untreated contralateral molars served as internal controls. After 12 days of OTM, the jaws were removed and examined by micro-computed tomography (µCT), decalcified histology, and immunohistochemistry. Our analysis of the untreated teeth confirmed that the periodontal phenotype of Rsk2-deficient mice is characterized by alveolar bone loss and hypoplasia of root cementum. Quantification of OTM using µCT revealed that OTM was more than two-fold faster in Rsk2-deficient mice as compared to WT. We also observed that OTM caused alveolar bone loss and root resorptions in WT and Rsk2-deficient mice. However, quantification of these orthodontic side effects revealed no differences between WT and Rsk2-deficient mice. Taken together, Rsk2 loss-of-function accelerates OTM in mice without causing more side effects.
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Affiliation(s)
- Cita Nottmeier
- Department of Orthodontics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Maximilian G Decker
- Department of Orthodontics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Julia Luther
- Institute of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Simon von Kroge
- Institute of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Bärbel Kahl-Nieke
- Department of Orthodontics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Michael Amling
- Institute of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Thorsten Schinke
- Institute of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Julian Petersen
- Institute of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Till Koehne
- Department of Orthodontics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
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Shu W, Zhang Y, Zhang C, You Q, Zhou H, Wen S. Triclosan inhibits the activation of human periodontal ligament fibroblasts induced by lipopolysaccharide from Porphyromonas gingivalis. J Biomed Res 2020; 35:206-215. [PMID: 33824247 PMCID: PMC8193714 DOI: 10.7555/jbr.34.20200026] [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] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Periodontitis is a highly prevalent, chronic, non-specific, and immunologically devastating disease of periodontal tissues, caused by microbial infection. This study aims to examine the efficacy and protective mechanism of triclosan (TCS), a bisphenolic, non-cationic component of oral care products, against periodontal inflammation induced by lipopolysaccharide purified from Porphyromonas gingivalis (LPS-PG). TCS markedly downregulated interleukin-6 (IL-6), IL-8, and IL-15 in human periodontal ligament fibroblasts (HPDLFs) treated with LPS-PG. By using a liquid chromatography-tandem mass spectrometry (LC-MS/MS) approach, 318 differentially expressed proteins (161 upregulated and 157 downregulated) were identified in TCS-pretreated HPDLFs. TCS upregulated HSPA5 and HSP90B1 but downregulated HSPA2. Besides, TCS upregulated miR-548i in HPDLFs, which downregulated IL-15. These results indicate that TCS attenuates the activation of HPDLFs and downregulates the inflammatory cytokines through various mechanisms, thus highlighting its protective role in periodontal inflammation.
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Affiliation(s)
- Wei Shu
- Department of Immunology, School of Basic Medical Sciences, Nanjing Medical University, Nanjing, Jiangsu 211166, China.,Department of Stomatology, Jiangsu Provincial Hospital of Traditional Chinese Medicine, Nanjing, Jiangsu 210029, China
| | - Yanman Zhang
- Department of Immunology, School of Basic Medical Sciences, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Chen Zhang
- Department of Biotherapeutics, the Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210011, China
| | - Qiang You
- Department of Biotherapeutics, the Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210011, China
| | - Hong Zhou
- Department of Immunology, School of Basic Medical Sciences, Nanjing Medical University, Nanjing, Jiangsu 211166, China.,Department of Biotherapeutics, the Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210011, China
| | - Shuang Wen
- Department of Immunology, School of Basic Medical Sciences, Nanjing Medical University, Nanjing, Jiangsu 211166, China
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Wang H, Feng C, Li M, Zhang Z, Liu J, Wei F. Analysis of lncRNAs-miRNAs-mRNAs networks in periodontal ligament stem cells under mechanical force. Oral Dis 2020; 27:325-337. [PMID: 32620026 DOI: 10.1111/odi.13530] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Revised: 03/15/2020] [Accepted: 06/19/2020] [Indexed: 12/21/2022]
Abstract
OBJECTIVES Our study aims to analyze the expression profiles of long non-coding RNAs (lncRNAs) and investigate the potential regulatory networks among lncRNAs, microRNAs (miRNAs), and mRNAs in periodontal ligament stem cells (PDLSCs) under mechanical force (MF). MATERIALS AND METHODS PDLSCs were isolated from human periodontal ligament tissues and identified by flow cytometry analysis. Multidirectional differentiation potential of PDLSCs was obtained by osteogenic and adipogenic induction. High-throughput RNA sequencing was used to identify the expression patterns of lncRNAs and mRNAs in PDLSCs under MF. MF-responsive miRNAs were obtained from the previous microarray data. LncRNAs-miRNAs-mRNAs networks were constructed by Cytoscape. RESULTS PDLSCs cultured from the periodontal ligament tissues were positive for STRO-1, CD146 and negative for CD45, CD34. Alizarin red staining and Oil Red O staining showed that PDLSCs had the ability of osteogenic and adipogenic differentiation. Then, a total of 1,339 and 1,426 differentially expressed lncRNAs and mRNAs were identified, respectively, in PDLSCs under MF. Based on the previous miRNA microarray analysis, the potential interaction networks of lncRNAs-miRNAs-mRNAs were constructed. It was found that lncRNAs and mRNAs could competitively interact with the same miRNA. CONCLUSIONS LncRNAs-miRNAs-mRNAs networks were involved in PDLSCs under MF, which might provide a novel mechanism in the regulation of clinical orthodontic tooth movement process.
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Affiliation(s)
- Hong Wang
- Department of Orthodontics, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, Jinan, China
| | - Cheng Feng
- Jinan Hospital for Nationalities, Jinan, China
| | - Mengying Li
- Department of Orthodontics, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, Jinan, China
| | - Zijie Zhang
- Department of Orthodontics, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, Jinan, China
| | - Jiani Liu
- Department of Orthodontics, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, Jinan, China
| | - Fulan Wei
- Department of Orthodontics, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, Jinan, China
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PERK-eIF2α-ATF4 signaling contributes to osteogenic differentiation of periodontal ligament stem cells. J Mol Histol 2020; 51:125-135. [PMID: 32124153 DOI: 10.1007/s10735-020-09863-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Accepted: 02/25/2020] [Indexed: 01/09/2023]
Abstract
Protein kinase-like endoplasmic reticulum kinase (PERK) is a type I transmembrane protein located in the endoplasmic reticulum (ER). The PERK-eukaryotic initiation factor 2α (eIF2α)-activating transcription factor 4 (ATF4) pathway has been proved to be involved in osteoblast differentiation, but the involvement of the PERK-eIF2α-ATF4 signaling pathway in osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs) has remained unclear. Therefore, the aim of this study was to explore the role of PERK in osteogenic differentiation of hPDLSCs and to assess whether PERK-eIF2α-ATF4 contributes to the process of osteogenic differentiation in hPDLSCs. In our study, we constructed PERK-overexpressed and PERK-silenced hPDLSCs by lentiviral transduction. Furthermore, lentivirus-transfected cells were induced to differentiate into osteoblast cells for different days. Alkaline phosphatase (ALP) activity and Alizarin Red staining were used to evaluate the mineralization capacity, and the expression levels of related genes-ATF4, ALP, bone sialoprotein, runt-related transcription factor 2 (Runx2), and osteocalcin were measured to evaluate the osteogenic differentiation of hPDLSCs. The results showed that over-expression of PERK greatly increased ALP activity and the expression levels of related osteogenic genes, which displayed the strongest osteogenesis capacity. However, suppression of PERK caused decreased ALP activity and the weakest osteogenesis capacity, and the levels of ATF4 and p-eIF2α in PERK-silenced hPDLSCs were also decreased. Our results indicated that the PERK gene plays an important role in the differentiation of hPDLSCs to osteoblast-like cells. The PERK-eIF2α-ATF4 signaling pathway contributes to osteoblast differentiation of hPDLSCs.
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Wada S, Kanzaki H, Narimiya T, Nakamura Y. Novel device for application of continuous mechanical tensile strain to mammalian cells. Biol Open 2017; 6:518-524. [PMID: 28302667 PMCID: PMC5399557 DOI: 10.1242/bio.023671] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
During orthodontic tooth movement, the periodontal ligament (PDL) is exposed to continuous mechanical strain. However, many researchers have applied cyclic tensile strain, not continuous tensile strain, to PDL cells in vitro because there has been no adequate device to apply continuous tensile strain to cultured cells. In this study, we contrived a novel device designed to apply continuous tensile strain to cells in culture. The continuous tensile strain was applied to human immortalized periodontal ligament cell line (HPL cells) and the cytoskeletal structures of HPL cells were examined by immunohistochemistry. The expression of both inflammatory and osteogenic markers was also examined by real-time reverse transcription polymerase chain reaction. The osteogenic protein, Osteopontin (OPN), was also detected by western blot analysis. The actin filaments of HPL cells showed uniform arrangement under continuous tensile strain. The continuous tensile strain increased the expression of inflammatory genes such as IL-1β, IL-6, COX-2 and TNF-α, and osteogenic genes such as RUNX2 and OPN in HPL cells. It also elevated the expression of OPN protein in HPL cells. These results suggest that our new simple device is useful for exploring the responses to continuous tensile strain applied to the cells. Summary: Continuous tensile strain from the device changed the cell morphology and increased the expression of inflammatory and osteogenic gene. These effects were similar to those in the PDL during orthodontic tooth movement.
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Affiliation(s)
- Satoshi Wada
- Department of Orthodontics, School of Dental Medicine, Tsurumi University, 2-1-3 Tsurumi, Tsurumi-ku, Yokohama, Kanagawa 230-8501, Japan
| | - Hiroyuki Kanzaki
- Department of Orthodontics, School of Dental Medicine, Tsurumi University, 2-1-3 Tsurumi, Tsurumi-ku, Yokohama, Kanagawa 230-8501, Japan
| | - Tsuyoshi Narimiya
- Department of Orthodontics, School of Dental Medicine, Tsurumi University, 2-1-3 Tsurumi, Tsurumi-ku, Yokohama, Kanagawa 230-8501, Japan
| | - Yoshiki Nakamura
- Department of Orthodontics, School of Dental Medicine, Tsurumi University, 2-1-3 Tsurumi, Tsurumi-ku, Yokohama, Kanagawa 230-8501, Japan
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Yang SY, Wei FL, Hu LH, Wang CL. PERK-eIF2α-ATF4 pathway mediated by endoplasmic reticulum stress response is involved in osteodifferentiation of human periodontal ligament cells under cyclic mechanical force. Cell Signal 2016; 28:880-6. [PMID: 27079961 DOI: 10.1016/j.cellsig.2016.04.003] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 03/31/2016] [Accepted: 04/07/2016] [Indexed: 02/03/2023]
Abstract
To prevent excess accumulation of unfolded proteins in endoplasmic reticulum (ER), eukaryotic cells have signaling pathways from the ER to the cytosol or nucleus. These processes are known as the endoplasmic reticulum stress (ERS) response. Protein kinase R like endoplasmic reticulum kinase (PERK) is a major transducer of the ERS response and it directly phosphorylate α-subunit of eukaryotic initiation factor 2 (eIF2α), resulting in translational attenuation. Phosphorylated eIF2α specifically promoted the translation of the activating transcription factor 4 (ATF4). ATF4 is a known important transcription factor which plays a pivotal role in osteoblast differentiation and bone formation. Furthermore, ATF4 is a downstream target of PERK. Studies have shown that PERK-eIF2α-ATF4 signal pathway mediated by ERS was involved in osteoblastic differentiation of osteoblasts. We have known that orthodontic tooth movement is a process of periodontal ligament cells (PDLCs) osteodifferentiation and alveolar bone remodeling under mechanical force. However, the involvement of PERK-eIF2α-ATF4 signal pathway mediated by ERS in osteogenic differentiation of PDLCs under mechanical force has not been unclear. In our study, we applied the cyclic mechanical force at 10% elongation with 0.5Hz to mimic occlusal force, and explored whether PERK-eIF2α-ATF4 signaling pathway mediated by ERS involved in osteogenic differentiation of PDLCs under mechanical force. Firstly, cyclic mechanical force will induce ERS and intensify several osteoblast marker genes (ATF4, OCN, and BSP). Next, we found that PERK overexpression increased eIF2α phosphorylation and expression of ATF4, furthermore induced BSP, OCN expression, thus it will promote osteodifferentiation of hPDLCs; mechanical force could promote this effect. However, PERK(-/-) cells showed the opposite changes, which will inhibit osteodifferentiation of hPDLCs. Taken together, our study proved that PERK-eIF2α-ATF4 signaling pathway mediated by ERS involved in osteoblast differentiation of PDLCs under cyclic mechanical force.
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Affiliation(s)
- Shuang-Yan Yang
- Department of Orthodontics, Shandong Provincial Key Laboratory of Oral Biomedicine, School of Stomatology, Shandong University, Jinan, Shandong 250012, PR China
| | - Fu-Lan Wei
- Department of Orthodontics, Shandong Provincial Key Laboratory of Oral Biomedicine, School of Stomatology, Shandong University, Jinan, Shandong 250012, PR China
| | - Li-Hua Hu
- Department of Orthodontics, Shandong Provincial Key Laboratory of Oral Biomedicine, School of Stomatology, Shandong University, Jinan, Shandong 250012, PR China
| | - Chun-Ling Wang
- Department of Orthodontics, Shandong Provincial Key Laboratory of Oral Biomedicine, School of Stomatology, Shandong University, Jinan, Shandong 250012, PR China.
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10
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Ren D, Wei F, Hu L, Yang S, Wang C, Yuan X. Phosphorylation of Runx2, induced by cyclic mechanical tension via ERK1/2 pathway, contributes to osteodifferentiation of human periodontal ligament fibroblasts. J Cell Physiol 2015; 230:2426-36. [PMID: 25740112 DOI: 10.1002/jcp.24972] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 02/24/2015] [Indexed: 12/18/2022]
Abstract
Occlusal force is an important stimulus for maintaining periodontal homeostasis. This is attributed to the quality of human periodontal ligament fibroblasts (hPDLFs) that could transfer occlusal force into biological signals modulating osteoblst differentiation. However, few studies investigated the mechanism of occlusal force-induced osteodifferentiation of hPDLFs. In our study, we used the cyclic mechanical tension (CMT) at 10% elongation with 0.5 Hz to mimic occlusal force, and explored its effects on osteogenesis of hPDLFs. Firstly, elevated expressions of several osteoblast marker genes (Runx2, ATF4, SP7, OCN, and BSP), as well as activated ERK1/2 pathway were detected during CMT loading for 1, 3, 6, 12, 18, and 24 h. To gain further insight into how CMT contributed to those effects, we focused on the classic ERK1/2-Runx2 pathway by inhibiting ERK1/2 and overexpressing Runx2. Our results reflected that Runx2 overexpression alone could induce osteodifferentiation of hPDLFs. Meanwhile, CMT loading could intensify while combined ERK1/2 blockage could weaken this process. Furthermore, we found that CMT promoted Runx2 transcription and phosphorylation via ERK1/2; protein level of phospho-Runx2 (p-Runx2), rather than Runx2, was in parallel with mRNA expressions of SP7, OCN, and BSP. Taken together, our study proved that p-Runx2, elevated by CMT via ERK1/2 pathway, is the predominate factor in promoting osteoblast differentiation of hPDLFs.
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Affiliation(s)
- Dapeng Ren
- Department of Orthodontics, Shandong University, Jinan, China
| | - Fulan Wei
- Department of Orthodontics, Qingdao Municipal Hospital, Qingdao University, the 4th Military Medical University, Qingdao, China
| | - Lihua Hu
- Department of Orthodontics, Qingdao Municipal Hospital, Qingdao University, the 4th Military Medical University, Qingdao, China
| | - Shuangyan Yang
- Department of Orthodontics, Qingdao Municipal Hospital, Qingdao University, the 4th Military Medical University, Qingdao, China
| | - Chunling Wang
- Department of Orthodontics, Shandong University, Jinan, China
| | - Xiao Yuan
- Department of Orthodontics, Qingdao Municipal Hospital, Qingdao University, the 4th Military Medical University, Qingdao, China
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Nettelhoff L, Grimm S, Jacobs C, Walter C, Pabst AM, Goldschmitt J, Wehrbein H. Influence of mechanical compression on human periodontal ligament fibroblasts and osteoblasts. Clin Oral Investig 2015; 20:621-9. [PMID: 26243456 DOI: 10.1007/s00784-015-1542-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 07/20/2015] [Indexed: 11/24/2022]
Abstract
OBJECTIVES The aim of this study was to investigate and compare the changes in human periodontal ligament fibroblasts (HPdLFs) and osteoblasts (HOBs) after the application of compressive force (CF) at two different strengths in vitro. MATERIALS AND METHODS HPdLF and HOB were exposed to CF with various strengths (5 and 10 %) using a Flexercell Compression Unit for 12 h in vitro. Viability was detected via 3-(4.5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide (MTT) and apoptosis rate by transferase dUTP nick end labeling (TUNEL) assay. The gene expression of alkaline phosphatase (ALP), osteocalcin (OCN), osteoprotegerin (OPG), and receptor activator of NF-κB ligand (RANKL) was analyzed using reverse transcriptase polymerase chain reaction (RT-PCR). Osteopontin (OPN), matrix metalloproteinase-8 (MMP-8), and tissue inhibition of metalloproteinase-1 (TIMP-1) were quantified by an ELISA. RESULTS Ten percent CF decreased viability, particularly in HOBs, but did not induce increased apoptosis. ALP gene expression increased the most after 5 % CF in HPdLFs and after 10 % CF in HOB. OCN was not affected by CF in either cell line. The highest RANKL/OPG ratio was measured after 5 % CF in both cell lines. OPN was upregulated in HOB by 5 %. HPdLFs showed an upregulation of MMP-8-synthesis and an increased MMP-8/TIMP-1 ratio. CONCLUSIONS HOBs have a greater effect on bone remodeling through the upregulation of OPN, whereas HPdLFs facilitate orthodontic tooth movement by influencing the extracellular matrix via the MMP-8/TIMP-1 ratio. CLINICAL RELEVANCE High CF in orthodontics should be avoided to prevent tissue damage, whereas moderate CF enables active tissue remodeling and tooth movement.
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Affiliation(s)
- L Nettelhoff
- Department of Orthodontics, University Medical Center, Johannes Gutenberg University Mainz, Augustusplatz 2, 55131, Mainz, Germany
| | - S Grimm
- Department of Orthodontics, University Medical Center, Johannes Gutenberg University Mainz, Augustusplatz 2, 55131, Mainz, Germany
| | - C Jacobs
- Department of Orthodontics, University Medical Center, Johannes Gutenberg University Mainz, Augustusplatz 2, 55131, Mainz, Germany.
| | - C Walter
- Department of Oral and Maxillofacial Surgery, University Medical Center, Johannes Gutenberg University Mainz, Augustusplatz 2, 55131, Mainz, Germany
| | - A M Pabst
- Department of Oral and Maxillofacial Surgery, University Medical Center, Johannes Gutenberg University Mainz, Augustusplatz 2, 55131, Mainz, Germany
| | - J Goldschmitt
- Department of Oral and Maxillofacial Surgery, University Medical Center, Johannes Gutenberg University Mainz, Augustusplatz 2, 55131, Mainz, Germany
| | - H Wehrbein
- Department of Orthodontics, University Medical Center, Johannes Gutenberg University Mainz, Augustusplatz 2, 55131, Mainz, Germany
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Effects of Hypergravity on Osteopontin Expression in Osteoblasts. PLoS One 2015; 10:e0128846. [PMID: 26046934 PMCID: PMC4457898 DOI: 10.1371/journal.pone.0128846] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 04/30/2015] [Indexed: 12/29/2022] Open
Abstract
Mechanical stimuli play crucial roles in bone remodeling and resorption. Osteopontin (OPN), a marker for osteoblasts, is important in cell communication and matrix mineralization, and is known to function during mechanotransduction. Hypergravity is a convenient approach to forge mechanical stimuli on cells. It has positive effects on certain markers of osteoblast maturation, making it a possible strategy for bone tissue engineering. We investigated the effects of hypergravity on OPN expression and cell signaling in osteoblasts. Hypergravity treatment at 20 g for 24 hours upregulated OPN expression in MC3T3-E1 cells at the protein as well as mRNA level. Hypergravity promoted OPN expression by facilitating focal adhesion assembly, strengthening actin bundles, and increasing Runx2 expression. In the hypergravity-triggered OPN expression pathway, focal adhesion assembly-associated FAK phosphorylation was upstream of actin bundle assembly.
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Ito M, Arakawa T, Okayama M, Shitara A, Mizoguchi I, Takuma T. Gravity loading induces adenosine triphosphate release and phosphorylation of extracellular signal-regulated kinases in human periodontal ligament cells. ACTA ACUST UNITED AC 2013; 5:266-74. [PMID: 23798356 DOI: 10.1111/jicd.12049] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Accepted: 02/23/2013] [Indexed: 01/24/2023]
Abstract
AIM The periodontal ligament (PDL) receives mechanical stress (MS) from dental occlusion or orthodontic tooth movement. Mechanical stress is thought to be a trigger for remodeling of the PDL and alveolar bone, although its signaling mechanism is still unclear. So we investigated the effect of MS on adenosine triphosphate (ATP) release and extracellular signal-regulated kinases (ERK) phosphorylation in PDL cells. METHODS Mechanical stress was applied to human PDL cells as centrifugation-mediated gravity loading. Apyrase, Ca(2+)-free medium and purinergic receptor agonists and antagonists were utilized to analyze the contribution of purinergic receptors to ERK phosphorylation. RESULTS Gravity loading and ATP increased ERK phosphorylation by 5 and 2.5 times, respectively. Gravity loading induced ATP release from PDL cells by tenfold. Apyrase and suramin diminished ERK phosphorylation induced by both gravity loading and ATP. Under Ca(2+)-free conditions the phosphorylation by gravity loading was partially decreased, whereas ATP-induced phosphorylation was unaffected. Receptors P2Y4 and P2Y6 were prominently expressed in the PDL cells. CONCLUSION Gravity loading induced ATP release and ERK phosphorylation in PDL fibroblasts, and ATP signaling via P2Y receptors was partially involved in this phosphorylation, which in turn would enhance gene expression for the remodeling of PDL tissue during orthodontic tooth movement.
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Affiliation(s)
- Mai Ito
- Department of Biochemistry, School of Dentistry, Health Sciences University of Hokkaido, Hokkaido, Japan; Department of Orthodontics, School of Dentistry, Health Sciences University of Hokkaido, Hokkaido, Japan
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14
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Wei FL, Geng J, Guo J, Guo QY, Wang H, Liu DX, Zhang BJ, Wang CL. Metabolic changes of human dental pulp after rapid palatal expansion. Orthod Craniofac Res 2013; 16:185-92. [PMID: 23458154 DOI: 10.1111/ocr.12021] [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] [Accepted: 02/09/2013] [Indexed: 11/27/2022]
Abstract
OBJECTIVES To investigate rapid palatal expansion (RPE)-induced metabolic changes in human dental pulp by measuring the expression and activity of aspartate aminotransferase (AST). METHODS mRNA and protein levels of AST in human dental pulp were measured by quantitative real-time polymerase chain reaction and Western blot, respectively. Furthermore, the activity of AST was measured by a full automatic biochemical analyzer. RESULTS AST mRNA and protein levels were found to be expressed in normal dental pulp. Moreover, the expression of AST was increased significantly after 14 days of RPE and then decreased at 1 month in retention. Three and 6 months after RPE, the AST expression level was gradually decreased to its baseline level. Similarly, AST activity was significantly elevated after 14 days of RPE, which was then down-regulated at 1 month in retention but was still kept at a higher level as compared with the control group. The enzymatic activity of AST was slowly decreased to its baseline level at 3 and 6 months in retention. CONCLUSIONS These results showed that significant reversible metabolic changes occurred in dental pulp during RPE, which revealed the high capacity of the pulp tissue for adaptation to this orthopedic method.
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Affiliation(s)
- F L Wei
- Department of Orthodontics, Shandong Provincial Key Laboratory of Oral Biomedicine, School of Stomatology, Shandong University, Jinan, China.
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15
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Kook SH, Jang YS, Lee JC. Involvement of JNK-AP-1 and ERK-NF-κB signaling in tension-stimulated expression of Type I collagen and MMP-1 in human periodontal ligament fibroblasts. J Appl Physiol (1985) 2011; 111:1575-83. [DOI: 10.1152/japplphysiol.00348.2011] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Type I collagen (COL I) and matrix metalloproteinase-1 (MMP-1) are the predominant matrix proteins in the extracellular matrix of the human periodontal ligament (PDL). The expression of these proteins in PDL fibroblasts (PLF) is sensitive to physiological and mechanical stress and is critical for PDL remodeling accompanied by alveolar bone remodeling. This study examined how dose tensile force regulates the expression of COL I and MMP-1 and explored the possible roles of mitogen-activated protein kinases (MAPKs) and transcription factors, such as activator protein-1 (AP-1) and nuclear factor-κB (NF-κB). Tensile force stimulated the mRNA expression of COL I and MMP-1 in the cells and also activated MAPKs including extracellular signal-regulated kinase (ERK), c-Jun NH2-terminal kinase (JNK), and p38 MAPK. A pharmacological inhibitor of ERK or JNK prevented the expression of matrix genes and the nuclear translocation of c-Jun proteins in the force-applied PLF. The knockdown of c-Jun by transfecting the cells with its antisense oligonucleotides reduced the force-induced increase in matrix gene expression. In particular, the ERK inhibitor but not JNK or p38 MAPK inhibitor attenuated the force-mediated stimulation of NF-κB-DNA binding and MMP-1 expression. Overall, these results highlight the mechanotransduction pathways involved in matrix gene expression in PLF, where the tension-stimulated expression of COL I and MMP-1 is controlled by the ERK/JNK-AP-1 and ERK-NF-κB signaling pathways.
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Affiliation(s)
- Sung-Ho Kook
- Division of Hematology and Oncology, Department of Medicine, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania
| | - Yong-Suk Jang
- Research Center of Bioactive Materials, Chonbuk National University
| | - Jeong-Chae Lee
- Research Center of Bioactive Materials, Chonbuk National University
- Cluster for Craniofacial Development and Regeneration Research, Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju, South Korea
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16
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Liu M, Dai J, Lin Y, Yang L, Dong H, Li Y, Ding Y, Duan Y. Effect of the cyclic stretch on the expression of osteogenesis genes in human periodontal ligament cells. Gene 2011; 491:187-93. [PMID: 22019432 DOI: 10.1016/j.gene.2011.09.031] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2011] [Revised: 09/20/2011] [Accepted: 09/29/2011] [Indexed: 11/25/2022]
Abstract
Periodontal ligament cells can potentially differentiate into osteoblast-like cells and influence the remodeling of periodontal tissues under mechanical strain conditions. In the present study, Gene chip technology was adopted to investigate the effect of the cyclic stretch on the expression of osteogenic-related genes in human periodontal ligament cells (HPDLCs). Cultured HPDLCs were subjected to 12% elongation cyclic stretch for 24 h using a Flexercell Strain Unit, and then GEArray Q series human osteogenesis gene expression profile chip with 96 spot array numbers was used to conduct parallel analyses on the change of the related gene expression in the osteogenic differentiation of HPDLCs stimulated by cyclic stretch. The results show that after the HPDLCs were stimulated by the cyclic stretch, the expression of 21 osteogenic-related genes was significantly upregulated, including 10 growth factor genes and their associated molecules, 10 extracellular matrix genes and their associated proteins, and 1 cell adhesion molecule. Two genes were significantly downregulated, including one growth factor gene and one cell adhesion molecule. Then the expressions of 10 candidate genes were validated using Real-time RT-PCR. These results indicate that cyclic stretch with 12% deformation can stimulate or inhibit some gene expression which was associated with the process of HPDLCs differentiation.
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Affiliation(s)
- Mingyan Liu
- Department of Orthodontics, College of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi Province 710032, People's Republic of China
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17
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Li S, Ma Z, Niu Z, Qian H, Xuan D, Hou R, Ni L. NASA-Approved Rotary Bioreactor Enhances Proliferation and Osteogenesis of Human Periodontal Ligament Stem Cells. Stem Cells Dev 2009; 18:1273-82. [PMID: 19327006 DOI: 10.1089/scd.2008.0371] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Shi Li
- Department of Endodontics, Fourth Military Medical University, Xi’an, Shaanxi, People’s Republic of China
- Center of Oral Disease, 306th Hospital, Beijing, People’s Republic of China
- Department of Orthodontics, Fourth Military Medical University, Xi’an, Shaanxi, People’s Republic of China
| | - Zhaofeng Ma
- Department of Oral and Maxillofacial Surgery, Fourth Military Medical University, Xi’an, Shaanxi, People’s Republic of China
- Department of Implantology, School of Stomatology, Fourth Military Medical University, Xi’an, Shaanxi, People’s Republic of China
| | - Zhongying Niu
- Department of Endodontics, Fourth Military Medical University, Xi’an, Shaanxi, People’s Republic of China
- Center of Oral Disease, 306th Hospital, Beijing, People’s Republic of China
| | - Hong Qian
- Department of Orthodontics, Fourth Military Medical University, Xi’an, Shaanxi, People’s Republic of China
| | - Dongying Xuan
- Department of Periodontology, Guangdong Provincial Stomatological Hospital, Southern Medical University, Guangzhou, People’s Republic of China
| | - Rui Hou
- Department of Oral and Maxillofacial Surgery, Fourth Military Medical University, Xi’an, Shaanxi, People’s Republic of China
| | - Longxing Ni
- Department of Endodontics, Fourth Military Medical University, Xi’an, Shaanxi, People’s Republic of China
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18
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Kook SH, Hwang JM, Park JS, Kim EM, Heo JS, Jeon YM, Lee JC. Mechanical force induces type I collagen expression in human periodontal ligament fibroblasts through activation of ERK/JNK and AP-1. J Cell Biochem 2009; 106:1060-7. [PMID: 19206162 DOI: 10.1002/jcb.22085] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Type I collagen (COL I) is the predominant collagen in the extracellular matrix of periodontal ligament (PDL), and its expression in PDL fibroblasts (PLF) is sensitive to mechanical force. However, the mechanism by which PLF induces COL I to respond to mechanical force is unclear. This study examined the nature of human PLF in mediating COL I expression in response to centrifugal force. Signal transduction pathways in the early stages of mechanotransduction involved in the force-driven regulation of COL I expression were also investigated. Centrifugal force up-regulated COL I without cytotoxicity and activated extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 kinase. ERK and JNK inhibitor blocked the expression of COL I but p38 kinase inhibitor had no effect. Centrifugal force activated activator protein-1 (AP-1) through dimerization between c-Fos and c-Jun transcription factors. ERK and JNK inhibitors also inhibited AP-1-DNA binding, c-Fos nuclear translocation, and c-Jun phosphorylation that were increased in the force-exposed PLF. Further, transfecting the cells with c-Jun antisense oligonucleotides almost completely abolished the force-induced increase of c-Jun phosphorylation and COL I induction. Our findings suggest that mechanical signals are transmitted into the nucleus by ERK/JNK signaling pathways and then stimulate COL I expression through AP-1 activation in force-exposed human PLF.
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Affiliation(s)
- Sung-Ho Kook
- Division of Biological Sciences, Chonbuk National University, Jeonju 561-756, South Korea
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Zhao Y, Wang C, Li S, Song H, Wei F, Pan K, Zhu K, Yang P, Tu Q, Chen J. Expression of Osterix in mechanical stress-induced osteogenic differentiation of periodontal ligament cells in vitro. Eur J Oral Sci 2008; 116:199-206. [PMID: 18471237 DOI: 10.1111/j.1600-0722.2008.00533.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023]
Abstract
Osterix (Osx) is an osteoblast-specific transcription factor required for the differentiation of pre-osteoblasts into functional osteoblasts. This study sought to examine the changes of Osx expression in periodontal ligament cells (PDLC) subjected to mechanical force, and to investigate whether Osx is involved in the mechanical stress-induced differentiation of PDLC. Human PDLC were exposed to centrifugal force for 1-12 h. Real-time polymerase chain reaction (PCR), western blot, and immunofluorescence assays were used to examine the mRNA and protein expression of Osx and its subcellular localization. Furthermore, PDLC were transfected with the expression vector pcDNA3.1 flag-Osx and subjected to mechanical force for 6 h. The changes in alkaline phosphatase (ALP) activity and in the expression of core-binding factor alpha1 (Cbfa1), ALP, osteopontin, bone sialoprotein, osteocalcin, and collagen I were measured. After the application of mechanical force, Osx was upregulated in a time-dependent manner at both mRNA and protein levels, and Osx protein was translocated from the cytosol into the cell nuclei. Overexpression of Osx did not affect the expression of Cbfa1, but it significantly enhanced the ALP activity and the mRNA expression of all the aforementioned osteogenic marker genes, all of which increased further under mechanical stress. These results suggest that Osx might play an important role in the mechanical stress-induced osteogenic differentiation of PDLC and therefore be involved in alveolar bone remodeling during orthodontic therapy.
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Affiliation(s)
- Yanhong Zhao
- School of Stomatology, Shandong University, Jinan, Shandong, China
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