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Lui JC. Growth disorders caused by variants in epigenetic regulators: progress and prospects. Front Endocrinol (Lausanne) 2024; 15:1327378. [PMID: 38370361 PMCID: PMC10870149 DOI: 10.3389/fendo.2024.1327378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 01/17/2024] [Indexed: 02/20/2024] Open
Abstract
Epigenetic modifications play an important role in regulation of transcription and gene expression. The molecular machinery governing epigenetic modifications, also known as epigenetic regulators, include non-coding RNA, chromatin remodelers, and enzymes or proteins responsible for binding, reading, writing and erasing DNA and histone modifications. Recent advancement in human genetics and high throughput sequencing technology have allowed the identification of causative variants, many of which are epigenetic regulators, for a wide variety of childhood growth disorders that include skeletal dysplasias, idiopathic short stature, and generalized overgrowth syndromes. In this review, we highlight the connection between epigenetic modifications, genetic variants in epigenetic regulators and childhood growth disorders being established over the past decade, discuss their insights into skeletal biology, and the potential of epidrugs as a new type of therapeutic intervention.
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Affiliation(s)
- Julian C. Lui
- Section on Growth and Development, National Institute of Child Health and Human Development, Bethesda, MD, United States
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2
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Chen Y, Tan J, Yang C, Ling Z, Xu J, Sun D, Luo F. Dynamic chromatin accessibility landscapes of osteoblast differentiation and mineralization. Biochim Biophys Acta Mol Basis Dis 2024; 1870:166938. [PMID: 37931716 DOI: 10.1016/j.bbadis.2023.166938] [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: 04/05/2023] [Revised: 10/12/2023] [Accepted: 10/29/2023] [Indexed: 11/08/2023]
Abstract
Bone acts as a self-healing organ, which undergoes continuous regeneration process that is tightly regulated by the cooperation of osteoclasts with the capability of bone resorption and osteoblasts with the capability of bone formation. Generally, bone marrow derived mesenchymal stem cells (BMSCs) differentiated to final osteoblasts have been considered as critical role in bone remodeling. In this regard, several transcription factors (TFs) whose binding sites are initially hidden deep within accessible chromatin that participate in modulating osteoblast differentiation and bone matrix mineralization. Then, it is necessary to explore further the dynamic changes about the epigenetic transcription machinery during osteoblastogenesis. Here, we performed the chromatin accessibility and transcriptomic landscape of osteoblast differentiation and mineralization by using transposase-accessible chromatin sequencing (ATAC-seq) and RNA sequencing (RNA-Seq). Our data found that global chromatin accessibility during osteoblastogenesis was extensively improved. Above this, it is shown that key target genes including Col6a3, Serpina3n, Ms4a4d, Lyz2, Phf11b and Grin3a were enriched in differential loci RNA-seq and ATAC-Seq peaks with continuous changed tendency during osteoblasts differentiation and mineralization. In addition, Analysis of Motif Enrichment (AME) was used to elucidate TFs which modulated these target genes. In this study, it was shown for the first time that these important TFs including MEF2A, PRRX1, Shox2 and HOXB13 could alter promoter accessibility of target genes during osteoblastogenesis. This helps us understand how TF binding motif accessibility influences osteoblast differentiation. In addition, it also suggests that modulating the chromatin accessibility of osteogenesis could be developed as the promising strategies to regulate bone regeneration.
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Affiliation(s)
- Yueqi Chen
- Department of Orthopedics, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, People's Republic of China; Department of Orthopedics, 76nd Group Army Hospital, Xining, People's Republic of China.
| | - Jiulin Tan
- Department of Orthopedics, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, People's Republic of China
| | - Chuan Yang
- Department of Biomedical Materials Science, Third Military Medical University (Army Medical University), Chongqing, People's Republic of China
| | - Zhiguo Ling
- Institute of Immunology, Third Military Medical University (Army Medical University), Chongqing, People's Republic of China
| | - Jianzhong Xu
- Department of Orthopedics, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, People's Republic of China
| | - Dong Sun
- Department of Orthopedics, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, People's Republic of China.
| | - Fei Luo
- Department of Orthopedics, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, People's Republic of China.
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Kumari P, Shirumalla RK, Bhalla V, Alam MS. New Emerging Aspect of Herbal Extracts for the Treatment of Osteoporosis: Overview. Curr Rheumatol Rev 2024; 20:361-372. [PMID: 38173067 DOI: 10.2174/0115733971273691231121131455] [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: 07/23/2023] [Revised: 10/10/2023] [Accepted: 10/12/2023] [Indexed: 01/05/2024]
Abstract
As the global population ages, osteoporosis is becoming a more common silent disease. Osteoporosis is characterized by decreased bone quality and strength, which increases the risk of fragility fractures in the elderly. According to estimates, 50% of women eventually suffer from an osteoporotic fracture. Due to increasing disability, more frequent hospital hospitalizations, and most critically, fragility fractures have been linked to a reduced quality of life. Osteoporotic fractures have been linked to an increased mortality risk; and must be considered in awareness as a serious health concern. There are anti-osteoporotic medications available that improve bone quality. Considering the availability of various treatment options, still there are a lot of underserved needs in the treatment of fractures and osteoporosis. For example, the application of natural products and herbal resources for fracture healing, because of the androgen-like and antioxidant characteristics of the plants, they can play a crucial for accelerating the repair of bone fractures. In this article, we'll discuss the herbal remedies that are essential for treating osteoporosis (bone disease).
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Affiliation(s)
- Priyanka Kumari
- Department of Pharmacology, SGT College of Pharmacy, SGT University, Gurgaon-Badli Road Chandu, Budhera, Gurugram, Haryana 122505, India
| | - Raj K Shirumalla
- Department of Pharmacology, SGT College of Pharmacy, SGT University, Gurgaon-Badli Road Chandu, Budhera, Gurugram, Haryana 122505, India
| | - Vijay Bhalla
- SGT College of Pharmacy, Department of Pharmacology, SGT University, Gurgaon-Badli Road Chandu, Budhera, Gurugram, Haryana 122505, India
| | - Md Sabir Alam
- Department of Pharmaceutics, SGT College of Pharmacy, Gurgaon-Badli Road Chandu, Budhera, Gurugram, Haryana 122505, India
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Yang S, Sun Y, Kapilevich L, Zhang X, Huang Y. Protective effects of curcumin against osteoporosis and its molecular mechanisms: a recent review in preclinical trials. Front Pharmacol 2023; 14:1249418. [PMID: 37790808 PMCID: PMC10544586 DOI: 10.3389/fphar.2023.1249418] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 09/04/2023] [Indexed: 10/05/2023] Open
Abstract
Osteoporosis (OP) is one of the most common metabolic skeletal disorders and is commonly seen in the elderly population and postmenopausal women. It is mainly associated with progressive loss of bone mineral density, persistent deterioration of bone microarchitecture, and increased fracture risk. To date, drug therapy is the primary method used to prevent and treat osteoporosis. However, long-term drug therapy inevitably leads to drug resistance and specific side effects. Therefore, researchers are constantly searching for new monomer compounds from natural plants. As a candidate for the treatment of osteoporosis, curcumin (CUR) is a natural phenolic compound with various pharmacological and biological activities, including antioxidant, anti-apoptotic, and anti-inflammatory. This compound has gained research attention for maintaining bone health in various osteoporosis models. We reviewed preclinical and clinical studies of curcumin in preventing and alleviating osteoporosis. These results suggest that if subjected to rigorous pharmacological and clinical trials, naturally-derived curcumin could be used as a complementary and alternative medicine for the treatment of osteoporosis by targeting osteoporosis-related mechanistic pathways. This review summarizes the mechanisms of action and potential therapeutic applications of curcumin in the prevention and mitigation of osteoporosis and provides reference for further research and development of curcumin.
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Affiliation(s)
- Shenglei Yang
- College of Exercise and Health, Shenyang Sport University, Shenyang, China
| | - Yuying Sun
- School of Stomatology, Binzhou Medical College, Yantai, China
| | - Leonid Kapilevich
- Faculty of Physical Education, Nаtionаl Reseаrch Tomsk Stаte University, Tomsk, Russiа
| | - Xin’an Zhang
- College of Exercise and Health, Shenyang Sport University, Shenyang, China
| | - Yue Huang
- College of Exercise and Health, Shenyang Sport University, Shenyang, China
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Hong CY, Lin SK, Wang HW, Shun CT, Yang CN, Lai EHH, Cheng SJ, Chen MH, Yang H, Lin HY, Wu FY, Kok SH. Metformin Reduces Bone Resorption in Apical Periodontitis Through Regulation of Osteoblast and Osteoclast Differentiation. J Endod 2023; 49:1129-1137. [PMID: 37454872 DOI: 10.1016/j.joen.2023.07.005] [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: 06/01/2023] [Revised: 07/05/2023] [Accepted: 07/05/2023] [Indexed: 07/18/2023]
Abstract
INTRODUCTION We have previously demonstrated that auxiliary metformin therapy promotes healing of apical periodontitis. Here we aimed to investigate the effects of metformin on osteoblast differentiation and osteoclast formation in cultured cells and rat apical periodontitis. METHODS Murine pre-osteoblasts MC3T3-E1 and macrophages RAW264.7 were cultured under hypoxia (2% oxygen) or normoxia (21% oxygen) and stimulated with receptor activator of nuclear factor-κB ligand (RANKL) when indicated. Metformin was added to the cultures to evaluate its anti-hypoxic effects. Expressions of osteoblast differentiation regulator runt-related transcription factor 2 (RUNX2), RANKL, and osteoclast marker tartrate-resistant acid phosphatase (TRAP) were assessed by Western blot. Apical periodontitis was induced in mandibular first molars of 10 Sprague-Dawley rats. Root canal therapy with or without metformin supplement was performed. Periapical bone resorption was measured by micro-computed tomography. Immunohistochemistry was used to examine RUNX2, RANKL, and TRAP expressions. RESULTS Hypoxia suppressed RUNX2 expression and enhanced RANKL synthesis in pre-osteoblasts. TRAP production increased in macrophages after hypoxia and/or RANKL stimulation. Metformin reversed hypoxia-induced RUNX2 suppression and RANKL synthesis in pre-osteoblasts. Metformin also inhibited hypoxia and RANKL-enhanced TRAP synthesis in macrophages. Intracanal metformin diminished bone loss in rat apical periodontitis. Comparing with vehicle control, cells lining bone surfaces in metformin-treated lesions had significantly stronger expression of RUNX2 and decreased synthesis of RANKL and TRAP. CONCLUSIONS Alleviation of bone resorption by intracanal metformin was associated with enhanced osteoblast differentiation and diminished osteoclast formation in rat apical periodontitis. Our results endorsed the role of metformin as an effective medicament for inflammatory bone diseases.
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Affiliation(s)
- Chi-Yuan Hong
- Department of Dentistry, National Taiwan University Hospital, Taipei, Taiwan; Department of Dentistry, School of Dentistry, College of Medicine, National Taiwan University, Taipei, Taiwan; College of Bio-Resources and Agriculture, National Taiwan University, Taipei, Taiwan
| | - Sze-Kwan Lin
- Department of Dentistry, National Taiwan University Hospital, Taipei, Taiwan; Department of Dentistry, School of Dentistry, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Han-Wei Wang
- Department of Dentistry, National Taiwan University Hospital, Taipei, Taiwan; Graduate Institute of Clinical Dentistry, School of Dentistry, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Chia-Tung Shun
- Department of Forensic Medicine and Pathology, National Taiwan University Hospital, Taipei, Taiwan
| | - Cheng-Ning Yang
- Department of Dentistry, School of Dentistry, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Eddie Hsiang-Hua Lai
- Department of Dentistry, National Taiwan University Hospital, Taipei, Taiwan; Department of Dentistry, School of Dentistry, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Shih-Jung Cheng
- Department of Dentistry, National Taiwan University Hospital, Taipei, Taiwan; Department of Dentistry, School of Dentistry, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Mu-Hsiung Chen
- Department of Dentistry, National Taiwan University Hospital, Taipei, Taiwan
| | - Hsiang Yang
- Department of Dentistry, National Taiwan University Hospital, Taipei, Taiwan
| | - Hung-Ying Lin
- Department of Dentistry, National Taiwan University Hospital, Taipei, Taiwan
| | - Fang-Yu Wu
- Department of Dentistry, National Taiwan University Hospital, Taipei, Taiwan
| | - Sang-Heng Kok
- Department of Dentistry, National Taiwan University Hospital, Taipei, Taiwan; Department of Dentistry, School of Dentistry, College of Medicine, National Taiwan University, Taipei, Taiwan.
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Cai L, Cui Y, Guo D, Chen H, Li J, Zhou X, Xie J. Microenvironmental Stiffness Directs Chondrogenic Lineages of Stem Cells from the Human Apical Papilla via Cooperation between ROCK and Smad3 Signaling. ACS Biomater Sci Eng 2023; 9:4831-4845. [PMID: 36797839 DOI: 10.1021/acsbiomaterials.2c01371] [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] [Indexed: 02/18/2023]
Abstract
Cell-based cartilage tissue engineering faces a great challenge in the repair process, partly due to the special physical microenvironment. Human stem cell from apical papilla (hSCAP) shows great potential as seed cells because of its versatile differentiation capacity. However, whether hSCAP has potent chondrogenic differentiation ability in the physical microenvironment of chondroid remains unknown. In this study, we fabricated poly(dimethylsiloxane) (PDMS) substrates with different stiffnesses and investigated the chondrogenic differentiation potential of hSCAPs. First, we found that hSCAPs cultured on soft substrates spread more narrowly accompanied by cortical actin organization, a hallmark of differentiated chondrocytes. On the contrary, stiff substrates were favorable for cell spreading and stress fiber formation. More importantly, the increased chondrogenic differentiation of hSCAPs seeded on soft substrates was confirmed by characterizing increased extracellular proteoglycan aggregation through Alcian blue staining and Safranin O staining and enhanced markers toward chondrogenic differentiation including SRY-box transcription factor 9 (Sox9), type II collagen (Col2), and aggrecan in both normal α-minimum essential medium (αMEM) and specific chondrogenic medium (CM) culture conditions. Then, we investigated the mechanosensing/mechanotransduction governing the chondrogenic differentiation of hSCAPs in response to different stiffnesses and found that stiffness-sensitive integrin β1 and focal adhesion kinase (FAK) were essential for mechanical signal perception and were oriented at the start of mechanotransduction induced by matrix stiffness. We next showed that the increased nuclear accumulation of Smad3 signaling and target Sox9 facilitated the chondrogenic differentiation of hSCAPs on the soft substrates and further verified the importance of Rho-associated protein kinase (ROCK) signaling in regulating chondrogenic differentiation and its driving factors, Smad3 and Sox9. By using SIS3, the specific inhibitor of p-Smad3, and miRNA targeting Rho-associated protein kinase 1 (ROCK-1), we finally confirmed the importance of ROCK/Smad3/Sox9 axis in the chondrogenic differentiation of hSCAPs in response to substrate stiffness. These results help us to increase the understanding of how microenvironmental stiffness directs chondrogenic differentiation from the aspects of mechanosensing, mechanotransduction, and cell fate decision, which will be of great value in the application of hSCAPs in cartilage tissue engineering.
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Affiliation(s)
- Linyi Cai
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Yujia Cui
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Daimo Guo
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Hao Chen
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Jiazhou Li
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Xuedong Zhou
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
- National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Jing Xie
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
- National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
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Atf7ip Inhibits Osteoblast Differentiation via Negative Regulation of the Sp7 Transcription Factor. Int J Mol Sci 2023; 24:ijms24054305. [PMID: 36901736 PMCID: PMC10002255 DOI: 10.3390/ijms24054305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Revised: 02/03/2023] [Accepted: 02/15/2023] [Indexed: 02/24/2023] Open
Abstract
Epigenetic modifications are critical for cell differentiation and growth. As a regulator of H3K9 methylation, Setdb1 is implicated in osteoblast proliferation and differentiation. The activity and nucleus localization of Setdb1 are regulated by its binding partner, Atf7ip. However, whether Atf7ip is involved in the regulation of osteoblast differentiation remains largely unclear. In the present study, we found that Atf7ip expression was upregulated during the osteogenesis of primary bone marrow stromal cells and MC3T3-E1 cells, and was induced in PTH-treated cells. The overexpression of Atf7ip impaired osteoblast differentiation in MC3T3-E1 cells regardless of PTH treatment, as measured by the expression of osteoblast differentiation markers, Alp-positive cells, Alp activity, and calcium deposition. Conversely, the depletion of Atf7ip in MC3T3-E1 cells promoted osteoblast differentiation. Compared with the control mice, animals with Atf7ip deletion in the osteoblasts (Oc-Cre;Atf7ipf/f) showed more bone formation and a significant increase in the bone trabeculae microarchitecture, as reflected by μ-CT and bone histomorphometry. Mechanistically, Atf7ip contributed to the nucleus localization of Setdb1 in MC3T3-E1, but did not affect Setdb1 expression. Atf7ip negatively regulated Sp7 expression, and through specific siRNA, Sp7 knockdown attenuated the enhancing role of Atf7ip deletion in osteoblast differentiation. Through these data, we identified Atf7ip as a novel negative regulator of osteogenesis, possibly via its epigenetic regulation of Sp7 expression, and demonstrated that Atf7ip inhibition is a potential therapeutic measure for enhancing bone formation.
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Lin B, Xu P, Zheng J, Deng X, Ye Q, Huang Z, Wang N. Effects and mechanisms of natural alkaloids for prevention and treatment of osteoporosis. Front Pharmacol 2022; 13:1014173. [PMID: 36210805 PMCID: PMC9539536 DOI: 10.3389/fphar.2022.1014173] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 08/31/2022] [Indexed: 11/20/2022] Open
Abstract
Natural alkaloids are polycyclic, nitrogen-containing, and basic compounds obtained from plants. In this review, the advances in bioactive alkaloids with respect to their chemical structures, herbal sources, and effects for the prevention and treatment of osteoporosis are discussed. Anti-osteoporosis alkaloids are classified into six categories based on the chemical structure, namely, isoquinoline alkaloids, quinolizidine alkaloids, piperidine alkaloids, indole alkaloids, pyrrolizidine alkaloids and steroidal alkaloids. They promote mesenchymal stem cells differentiation, improve osteoblast proliferation, stimulate osteoblast autophagy and suppress osteoclast formation. These natural alkaloids can regulate multiple signaling pathways, including interrupting the tumor necrosis factor receptor associated factor 6- receptor activator of nuclear factor kappa B interaction, inhibiting the nuclear factor kappa B pathway in osteoclasts, activating the p38 mitogen-activated protein kinases pathway in osteoblasts, and triggering the wingless and int-1 pathway in mesenchymal stem cells. This review provides evidence and support for novel drug and clinical treatment of osteoporosis using natural alkaloids.
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Affiliation(s)
- Bingfeng Lin
- Department of Medicine, Zhejiang Academy of Traditional Chinese Medicine, Hangzhou, China
| | - Pingcui Xu
- Department of Medicine, Zhejiang Academy of Traditional Chinese Medicine, Hangzhou, China
| | - Juan Zheng
- Hangzhou Institute for Food and Drug Control, Hangzhou, China
| | - Xuehui Deng
- School of Pharmacy, Zhejiang Chinese Medical University, Hangzhou, China
| | - Qitao Ye
- School of Pharmacy, Zhejiang Chinese Medical University, Hangzhou, China
| | - Zhongping Huang
- College of Chemical Engineering, Zhejiang University of Technology, Hangzhou, China
| | - Nani Wang
- Department of Medicine, Zhejiang Academy of Traditional Chinese Medicine, Hangzhou, China
- *Correspondence: Nani Wang,
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Zhu J, Feng C, Zhang W, Wang Z, Zhong M, Tang W, Wang Z, Shi H, Yin Z, Shi J, Huang Y, Xiao L, Geng D, Wang Z. Activation of dopamine receptor D1 promotes osteogenic differentiation and reduces glucocorticoid-induced bone loss by upregulating the ERK1/2 signaling pathway. Mol Med 2022; 28:23. [PMID: 35189819 PMCID: PMC8862482 DOI: 10.1186/s10020-022-00453-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Accepted: 02/08/2022] [Indexed: 11/16/2022] Open
Abstract
Background The inhibition of osteogenic differentiation is a major factor in glucocorticoid-induced bone loss, but there is currently no effective treatment. Dopamine, a major neurotransmitter, transmits signals via five different seven-transmembrane G protein-coupled receptors termed D1 to D5. Although the relevance of the neuroendocrine system in bone metabolism has emerged, the precise effects of dopamine receptor signaling on osteoblastogenesis remain unknown. Methods In vitro, western blotting and immunofluorescence staining were used to observe the expression of dopamine receptors in MC3T3-E1 and BMSCs cells treated with dexamethasone (Dex). In addition, Alizarin red S (ARS) and alkaline phosphatase (ALP) staining and western blotting were used to evaluate the effect of D1R activation on osteogenic differentiation in Dex-induced MC3T3-E1 cells via the ERK1/2 signaling pathway. In vivo, micro-CT and hematoxylin and eosin (H&E), toluidine blue and immunohistochemical staining were used to determine the effect of D1R activation on Dex-induced bone loss. Results We demonstrated that the trend in D1R but not D2-5R was consistent with that of osteogenic markers in the presence of Dex. We also demonstrated that the activation of D1R promoted Dex-induced osteogenic differentiation by activating the ERK1/2 pathway in vitro. We further demonstrated that a D1R agonist could reduce Dex-induced bone loss, while pretreatment with a D1R inhibitor blocked the effect of a D1R agonist in vivo. Conclusions Activation of D1R promotes osteogenic differentiation and reduces Dex-induced bone loss by activating the ERK1/2 pathway. Hence, D1R could serve as a potential therapeutic target for glucocorticoid-induced osteoporosis. Supplementary Information The online version contains supplementary material available at 10.1186/s10020-022-00453-0.
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Becker K, Rauch N, Brunello G, Azimi S, Beller M, Hüfner M, Nienkemper M, Schwarz-Herzke B, Drescher D. Bone remodelling patterns around orthodontic mini-implants migrating in bone: an experimental study in rat vertebrae. Eur J Orthod 2021; 43:708-717. [PMID: 34476491 PMCID: PMC8643410 DOI: 10.1093/ejo/cjab065] [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] [Indexed: 11/13/2022]
Abstract
Background Orthodontic implant migration has been clinically observed in presence of continuous loading forces. Recent studies indicate that osteocytes play a crucial role in this phenomenon. Objectives Aim of this study was to investigate local osteocytic gene expression, protein expression, and bone micro-structure in peri-implant regions of pressure and tension. Material and methods The present work reports a complementary analysis to a previous micro-computed tomography study. Two customized mini-implants were placed in one caudal rat vertebra and connected by a nickel–titanium contraction spring generating different forces (i.e. 0, 0.5, 1.0, and 1.5 N). Either at 2 or 8 weeks, the vertebrae were harvested and utilized for 1. osteocytic gene expression using laser capture micro-dissection on frozen sections coupled with qPCR, 2. haematoxylin–eosin staining for qualitative and quantitative analyses, 3. immunofluorescence staining and analysis, and 4. bone-to-implant contact on undecalcified samples. Results At the two time points for all the performed analyses no significant differences were observed with respect to the applied force magnitudes and cell harvesting localization. However, descriptive histological analysis revealed remarkable bone remodelling at 2 weeks of loading. At 8 weeks the implants were osseointegrated and, especially in 1.0 and 1.5 N groups, newly formed bone presented a characteristic load bearing architecture with trabecula oriented in the direction of the loading. Conclusions The present study confirmed that stress-induced bone remodelling is the biological mechanism of orthodontic implant migration. Bone apposition was found at ‘tension’ and ‘pressure’ sites thus limiting implant migration over time.
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Affiliation(s)
- Kathrin Becker
- Department of Orthodontics, University Clinic of Düsseldorf, Germany
| | - Nicole Rauch
- Department of Oral Surgery, University Clinic of Düsseldorf, Germany
| | - Giulia Brunello
- Department of Oral Surgery, University Clinic of Düsseldorf, Germany.,Department of Neurosciences, University of Padua, Italy
| | - Sarah Azimi
- Department of Orthodontics, University Clinic of Düsseldorf, Germany
| | - Mathias Beller
- Institute for Mathematical Modeling of Biological Systems, University of Düsseldorf, Germany.,Systems Biology of Lipid Metabolism, University of Düsseldorf, Germany
| | - Mira Hüfner
- Department of Orthodontics, University Clinic of Düsseldorf, Germany
| | - Manuel Nienkemper
- Department of Orthodontics, University Clinic of Düsseldorf, Germany.,Private Practice, Dusseldorf, Germany
| | | | - Dieter Drescher
- Department of Orthodontics, University Clinic of Düsseldorf, Germany
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