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Liu Z, Wang Q, Zhang J, Qi S, Duan Y, Li C. The Mechanotransduction Signaling Pathways in the Regulation of Osteogenesis. Int J Mol Sci 2023; 24:14326. [PMID: 37762629 PMCID: PMC10532275 DOI: 10.3390/ijms241814326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 09/14/2023] [Accepted: 09/19/2023] [Indexed: 09/29/2023] Open
Abstract
Bones are constantly exposed to mechanical forces from both muscles and Earth's gravity to maintain bone homeostasis by stimulating bone formation. Mechanotransduction transforms external mechanical signals such as force, fluid flow shear, and gravity into intracellular responses to achieve force adaptation. However, the underlying molecular mechanisms on the conversion from mechanical signals into bone formation has not been completely defined yet. In the present review, we provide a comprehensive and systematic description of the mechanotransduction signaling pathways induced by mechanical stimuli during osteogenesis and address the different layers of interconnections between different signaling pathways. Further exploration of mechanotransduction would benefit patients with osteoporosis, including the aging population and postmenopausal women.
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Affiliation(s)
- Zhaoshuo Liu
- School of Engineering Medicine, Beihang University, Beijing 100191, China
- School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China
| | - Qilin Wang
- School of Engineering Medicine, Beihang University, Beijing 100191, China
- School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China
| | - Junyou Zhang
- School of Engineering Medicine, Beihang University, Beijing 100191, China
- School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China
| | - Sihan Qi
- School of Engineering Medicine, Beihang University, Beijing 100191, China
- School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China
| | - Yingying Duan
- School of Engineering Medicine, Beihang University, Beijing 100191, China
- School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China
| | - Chunyan Li
- School of Engineering Medicine, Beihang University, Beijing 100191, China
- School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China
- Key Laboratory of Big Data-Based Precision Medicine (Ministry of Industry and Information Technology), Beihang University, Beijing 100191, China
- Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, Beihang University, Beijing 100191, China
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Liu Y, Chen Y, Li XH, Cao C, Zhang HX, Zhou C, Chen Y, Gong Y, Yang JX, Cheng L, Chen XD, Shen H, Xiao HM, Tan LJ, Deng HW. Dissection of Cellular Communication between Human Primary Osteoblasts and Bone Marrow Mesenchymal Stem Cells in Osteoarthritis at Single-Cell Resolution. Int J Stem Cells 2023; 16:342-355. [PMID: 37105556 PMCID: PMC10465330 DOI: 10.15283/ijsc22101] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 11/14/2022] [Accepted: 11/21/2022] [Indexed: 04/29/2023] Open
Abstract
Background and Objectives Osteoblasts are derived from bone marrow mesenchymal stem cells (BMMSCs) and play important role in bone remodeling. While our previous studies have investigated the cell subtypes and heterogeneity in osteoblasts and BMMSCs separately, cell-to-cell communications between osteoblasts and BMMSCs in vivo in humans have not been characterized. The aim of this study was to investigate the cellular communication between human primary osteoblasts and bone marrow mesenchymal stem cells. Methods and Results To investigate the cell-to-cell communications between osteoblasts and BMMSCs and identify new cell subtypes, we performed a systematic integration analysis with our single-cell RNA sequencing (scRNA-seq) transcriptomes data from BMMSCs and osteoblasts. We successfully identified a novel preosteoblasts subtype which highly expressed ATF3, CCL2, CXCL2 and IRF1. Biological functional annotations of the transcriptomes suggested that the novel preosteoblasts subtype may inhibit osteoblasts differentiation, maintain cells to a less differentiated status and recruit osteoclasts. Ligand-receptor interaction analysis showed strong interaction between mature osteoblasts and BMMSCs. Meanwhile, we found FZD1 was highly expressed in BMMSCs of osteogenic differentiation direction. WIF1 and SFRP4, which were highly expressed in mature osteoblasts were reported to inhibit osteogenic differentiation. We speculated that WIF1 and sFRP4 expressed in mature osteoblasts inhibited the binding of FZD1 to Wnt ligand in BMMSCs, thereby further inhibiting osteogenic differentiation of BMMSCs. Conclusions Our study provided a more systematic and comprehensive understanding of the heterogeneity of osteogenic cells. At the single cell level, this study provided insights into the cell-to-cell communications between BMMSCs and osteoblasts and mature osteoblasts may mediate negative feedback regulation of osteogenesis process.
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Affiliation(s)
- Ying Liu
- Laboratory of Molecular and Statistical Genetics, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Yan Chen
- Laboratory of Molecular and Statistical Genetics, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Xiao-Hua Li
- Laboratory of Molecular and Statistical Genetics, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Chong Cao
- Laboratory of Molecular and Statistical Genetics, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Hui-Xi Zhang
- Laboratory of Molecular and Statistical Genetics, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Cui Zhou
- Laboratory of Molecular and Statistical Genetics, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Yu Chen
- Laboratory of Molecular and Statistical Genetics, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Yun Gong
- Tulane Center of Biomedical Informatics and Genomics, Deming Department of Medicine, Tulane University School of Medicine, New Orleans, LA, USA
| | - Jun-Xiao Yang
- Department of Orthopedics, Xiangya Hospital, Central South University, Changsha, China
| | - Liang Cheng
- Department of Orthopedics and National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Xiang-Ding Chen
- Laboratory of Molecular and Statistical Genetics, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Hui Shen
- Tulane Center of Biomedical Informatics and Genomics, Deming Department of Medicine, Tulane University School of Medicine, New Orleans, LA, USA
| | - Hong-Mei Xiao
- School of Basic Medical Science, Central South University, Changsha, China
- Center of Reproductive Health, System Biology and Data Information, Institute of Reproductive & Stem Cell Engineering, School of Basic Medical Science, Central South University, Changsha, China
| | - Li-Jun Tan
- Laboratory of Molecular and Statistical Genetics, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Hong-Wen Deng
- Tulane Center of Biomedical Informatics and Genomics, Deming Department of Medicine, Tulane University School of Medicine, New Orleans, LA, USA
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Omagari D, Hayatsu M, Yamamoto K, Kobayashi M, Tsukano N, Nameta M, Mikami Y. Gap junction with MLO-A5 osteoblast-like cell line induces ALP and BSP transcription of 3T3-L1 pre-adipocyte like cell line via Hspb1 while retaining adipogenic differentiation ability. Bone 2020; 141:115596. [PMID: 32814124 DOI: 10.1016/j.bone.2020.115596] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 08/09/2020] [Accepted: 08/10/2020] [Indexed: 12/09/2022]
Abstract
In bone tissues, gap junctions form direct links between the cytoplasm of an osteocyte and another adjacent osteocyte or osteoblast, which underlie both bone formation and bone resorption. We have previously demonstrated that alkaline phosphatase (ALP) and bone sialoprotein (BSP), which are osteoblast markers, were induced in mesenchymal stem cells (MSCs) co-cultured with osteoblast-like cell line. However, the molecular mechanism of this process has not been fully addressed. Furthermore, few advances have been made toward elucidating the communication networks that link the status of committed cells such as (pre-) adipocytes that differentiated from MSCs as well as osteoblasts. Therefore, the objective of the present study was to investigate the mechanism underlying the communication network between pre-adipocytes and osteoblasts. We evaluated the effect of co-culture with osteoblast on the cell status of pre-adipocytes using murine osteoblast-like cell line, MLO-A5, and pre-adipocyte-like cell line, 3T3-L1, respectively. The results presented here demonstrated that osteoblasts and pre-adipocytes communicate via gap junctions, and the ensuing drastic increase in ALP and BSP transcription in co-cultured pre-adipocytes was induced, at least partly, via heat shock protein family B member 1 (Hspb1). In addition, terminal differentiation into adipocytes was suppressed in pre-adipocytes during co-culture with osteoblast without loss of adipogenic differentiation ability. Interestingly, after co-culture with osteoblasts, isolated co-cultured pre-adipocytes were able to differentiate to adipocytes as well as original pre-adipocytes. These results suggest that gap junctional communication with osteoblasts suppressed adipogenic differentiation of pre-adipocytes without loss of adipogenic differentiation ability.
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Affiliation(s)
- Daisuke Omagari
- Department of Pathology, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan
| | - Manabu Hayatsu
- Division of Microscopic Anatomy, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata-shi, Niigata 951-8122, Japan
| | - Kiyofumi Yamamoto
- Department of Pharmacology, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan
| | - Masayuki Kobayashi
- Department of Pharmacology, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan
| | - Naruchika Tsukano
- Division of Microscopic Anatomy, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata-shi, Niigata 951-8122, Japan
| | - Masaaki Nameta
- Electron Microscope Core Facility, Niigata University, 1-757 Asahimachi-dori, Chuo-ku, Niigata-shi, Niigata 951-8122, Japan
| | - Yoshikazu Mikami
- Division of Microscopic Anatomy, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata-shi, Niigata 951-8122, Japan.
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Zhong W, Li X, Pathak JL, Chen L, Cao W, Zhu M, Luo Q, Wu A, Chen Y, Yi L, Ma M, Zhang Q. Dicalcium silicate microparticles modulate the differential expression of circRNAs and mRNAs in BMSCs and promote osteogenesis via circ_1983–miR-6931–Gas7 interaction. Biomater Sci 2020; 8:3664-3677. [PMID: 32463418 DOI: 10.1039/d0bm00459f] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Among C2S-induced differentially expressed circRNAs, circ_1983 is involved in osteogenesis via circ_1983–miR-6931–Gas7 ceRNA interaction-mediated Runx2 upregulation.
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Zhao C, Wang X, Gao L, Jing L, Zhou Q, Chang J. The role of the micro-pattern and nano-topography of hydroxyapatite bioceramics on stimulating osteogenic differentiation of mesenchymal stem cells. Acta Biomater 2018; 73:509-521. [PMID: 29678674 DOI: 10.1016/j.actbio.2018.04.030] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 04/14/2018] [Accepted: 04/16/2018] [Indexed: 02/07/2023]
Abstract
The micro/nano hybrid structure is considered to be a biomaterial characteristic to stimulate osteogenesis by mimicking the three-dimensional structure of the bone matrix. However, the mechanism of the hybrid structure induced osteogenic differentiation of stem cells is still unknown. For elucidating the mechanisms, one of the challenge is to directly fabricate micro/nano hybrid structure on bioceramics because of its brittleness. In this study, hydroxyapatite (HA) bioceramics with the micro/nano hybrid structure were firstly fabricated via a hydrothermal treatment and template method, and the effect of the different surface structures on the expression of integrins, BMP2 signaling pathways and cell-cell communication was investigated. Interestingly, the results suggested that the osteogenic differentiation induced by micro/nano structures was modulated first through activating integrins and then further activating BMP2 signaling pathway and cell-cell communication, while activated BMP2 could in turn activate integrins and Cx43-related cell-cell communication. Furthermore, differences in activation of integrins, BMP2 signaling pathway, and gap junction-mediated cell-cell communication were observed, in which nanorod and micropattern structures activated different integrin subunits, BMP downstream receptors and Cx43. This finding may explain the synergistic effect of the micro/nano hybrid structure on the activation of osteogenic differentiation of BMSCs. Based on our study, we concluded that the different activation mechanisms of micro- and nano-structures led to the synergistic stimulatory effect on integrin activation and osteogenesis, in which not only the direct contact of cells on micro/nano structure played an important role, but also other surface characteristics such as protein adsorption might contribute to the bioactive effect. STATEMENT OF SIGNIFICANCE The micro/nano hybrid structure has been found to have synergistic bioactivity on osteogenesis. However, it is still a challenge to fabricate the hybrid structure directly on the bioceramics, and the role of micro- and nano-structure, in particular the mechanism of the micro/nano-hybrid structure induced stem cell differentiation is still unknown. In this study, we firstly fabricated hydroxyapatite bioceramics with the micro/nano hybrid structure, and then investigated the effect of different surface structure on expression of integrins, BMP2 signaling pathways and cell-cell communication. Interestingly, we found that the osteogenic differentiation induced by structure was modulated first through activating integrins and then further activating BMP2 signaling pathway and cell-cell communication, and activated BMP2 could in turn activate some integrin subunits and Cx43-related cell-cell communication. Furthermore, differences in activation of integrins, BMP2 signaling pathway, and gap junction-mediated cell-cell communication were observed, in which nanorod and micropattern structures activated different integrin subunits, BMP downstream receptors and Cx43. This finding may explain the synergistic effect of the micro/nano hybrid structure on the activation of osteogenic differentiation of BMSCs. Based on our study, we concluded that the different activation mechanisms of micro- and nano-structures led to the synergistic stimulatory effect on integrin activation and osteogenesis, in which not only the direct contact of cells on micro/nano structure played an important role, but also other surface characteristics such as protein adsorption might contribute to the bioactive effect.
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Takamura T, Suguro H, Mikami Y, Iwase T, Komiyama Y, Kuyama K, Komiyama K, Oki H. Comparison of gene expression profiles of gingival carcinoma Ca9-22 cells and colorectal adenocarcinoma HT-29 cells to identify potentially important mediators of SLPI-induced cell migration. J Oral Sci 2018. [PMID: 28637988 DOI: 10.2334/josnusd.16-0534] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
Secretory leukocyte protease inhibitor (SLPI) is a serine protease inhibitor whose expression level is positively correlated with tumor aggressiveness and metastatic potential. However, the mechanism underlying SLPI-induced enhancement of malignant phenotype is not completely understood. The malignancy of cancer cells is highly dependent on cell migration activity. Our previous study revealed that gingival carcinoma Ca9-22 cells, but not colorectal adenocarcinoma HT-29 cells, expressed SLPI. Therefore, we investigated the migration activity of these two cell types to understand the nature of SLPI-mediated tumor aggressiveness and metastatic potential. In vitro wound healing assay indicated that HT-29 cells and SLPI-deleted Ca9-22 cells showed lower migration activity than wild-type Ca9-22 cells, suggesting that SLPI-induced cell migration plays an important role in tumor aggressiveness and metastatic potential. In addition, our gene expression profiling study based on microarray data for the three cell types identified a number of candidates, including LCP1 and GLI, that could be key molecules in the mechanism of SLPI-induced cell migration.
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Affiliation(s)
- Tsuyoshi Takamura
- Department of Oral and Maxillofacial Surgery, Nihon University School of Dentistry
| | - Hisashi Suguro
- Department of Endodontics, Nihon University School of Dentistry
| | - Yoshikazu Mikami
- Division of Microscopic Anatomy, Niigata University Graduate School of Medical and Dental Sciences
| | - Takashi Iwase
- Department of Pathology, Nihon University School of Dentistry
| | - Yusuke Komiyama
- Department of Oral and Maxillofacial Surgery, Dokkyo Medical University School of Medicine
| | - Kayo Kuyama
- Department of Oral Pathology, Nihon University School of Dentistry at Matsudo
| | - Kazuo Komiyama
- Department of Pathology, Nihon University School of Dentistry
| | - Hiderou Oki
- Department of Oral and Maxillofacial Surgery, Nihon University School of Dentistry
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Lee SI, Ko Y, Park JB. Evaluation of the shape, viability, stemness and osteogenic differentiation of cell spheroids formed from human gingiva-derived stem cells and osteoprecursor cells. Exp Ther Med 2017; 13:3467-3473. [PMID: 28587426 PMCID: PMC5450690 DOI: 10.3892/etm.2017.4388] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 03/17/2017] [Indexed: 12/14/2022] Open
Abstract
The present study was performed to create stem cell spheroids from human gingiva-derived stem cells and osteoprecursor cells and to evaluate the maintenance of the stemness, the viability and osteogenic differentiation of the cell spheroids. Gingiva-derived stem cells were isolated, and a total of 6×105 stem cells and osteoprecursor cells were seeded into concave micromolds at various ratios. Gingiva-derived stem cells and/or osteoprecursor cells formed spheroids in concave microwells. The spheroids demonstrated a smaller diameter when the number of osteoprecursor cells seeded was lower. The majority of cells in the spheroids were identified to be live cells and the cell spheroids preserved viability throughout the experimental period. The cell spheroids, which contained stem cells, were positive for stem-cell markers. Cell spheroids in concave microwells demonstrated a statistically significant increase in alkaline phosphatase activity as time progressed (P<0.05). A statistically significant difference in phosphatase activity was observed in the stem cell alone group when compared with the osteoprecursor cell group at day 5 (P<0.05). Mineralized extracellular deposits were observed in each group after Alizarin Red S staining. Within the limits of the present study, cell spheroids from gingival cells and osteoprecursor cells maintained shape, viability, stemness and osteogenic differentiation potential.
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Affiliation(s)
- Sung-Il Lee
- Department of Periodontics, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea
| | - Youngkyung Ko
- Department of Periodontics, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea
| | - Jun-Beom Park
- Department of Periodontics, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea
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Mikami Y, Fukushima A, Komiyama Y, Iwase T, Tsuda H, Higuchi Y, Hayakawa S, Kuyama K, Komiyama K. Human uterus myoma and gene expression profiling: A novel in vitro model for studying secretory leukocyte protease inhibitor-mediated tumor invasion. Cancer Lett 2016; 379:84-93. [PMID: 27238568 DOI: 10.1016/j.canlet.2016.05.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 05/24/2016] [Accepted: 05/25/2016] [Indexed: 12/20/2022]
Abstract
Secretory leukocyte protease inhibitor (SLPI) is a serine protease inhibitor that diminishes tissue destruction during inflammation. A recent report revealed high levels of SLPI expression in the oral carcinoma cell. In addition, overexpression of SLPI up-regulates metastasis in lung carcinoma cells. On the other hand, matrix metalloproteinases (MMPs) are proteinases that participate in extracellular matrix degradation. SLPI and MMPs are involved as accelerators of the tumor invasion process; however, their exact roles are not fully understood. Understanding the mechanism of tumor invasion requires models that take the effect of microenvironmental factors into account. In one such in vitro model, different carcinoma cells have been shown to invade myoma tissue in highly distinct patterns. We have used this myoma model, as it provides a more natural stroma-like environment, to investigate the role of SLPI in tumor invasion. Our results indicate that the model provides a relevant matrix for tumor invasion studies, and that SLPI is important for the invasion of oral carcinoma Ca9-22 cells in conjunction with MMPs. Furthermore, using bioinformatics analysis, we have identified candidates as key molecules involved in SLPI-mediated tumor invasion.
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Affiliation(s)
- Yoshikazu Mikami
- Department of Pathology, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan; Division of Microscopic Anatomy, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata-shi, Niigata 951-8122, Japan.
| | - Atsushi Fukushima
- RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro, Tsurumi, Yokohama-shi, Kanagawa 230-0045, Japan
| | - Yusuke Komiyama
- Department of Oral and Maxillofacial Surgery, Dokkyo Medical University School of Medicine, Mibu, Shimotsuga-gun, Tochigi, Japan
| | - Takashi Iwase
- Department of Pathology, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan
| | - Hiromasa Tsuda
- Department of Biochemistry, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan
| | - Yasuhiko Higuchi
- Department of Obstetrics and Gynecology, Seibo International Catholic Hospital, 2-5-1 Nakaochiai, Shinjuku-ku, Tokyo 161-8521, Japan
| | - Satoshi Hayakawa
- Department of Pathology and Microbiology, Division of Microbiology, Nihon University School of Medicine, 30-1 Oyaguchi Kami-cho, Itabashi-ku, Tokyo 173-8610, Japan
| | - Kayo Kuyama
- Department of Oral Pathology, Nihon University School of Dentistry at Matsudo, 2-870-1 Sakae-cho Nishi, Matsudo-shi, Chiba 271-8587, Japan
| | - Kazuo Komiyama
- Department of Pathology, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.
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Abstract
Shaping of the skeleton (modeling) and its maintenance throughout life (remodeling) require coordinated activity among bone forming (osteoblasts) and resorbing cells (osteoclasts) and osteocytes (bone embedded cells). The gap junction protein connexin43 (Cx43) has emerged as a key modulator of skeletal growth and homeostasis. The skeletal developmental abnormalities present in oculodentodigital and craniometaphyseal dysplasias, both linked to Cx43 gene (GJA1) mutations, demonstrate that the skeleton is a major site of Cx43 action. Via direct action on osteolineage cells, including altering production of pro-osteoclastogenic factors, Cx43 contributes to peak bone mass acquisition, cortical modeling of long bones, and maintenance of bone quality. Cx43 also contributes in diverse ways to bone responsiveness to hormonal and mechanical signals. Skeletal biology research has revealed the complexity of Cx43 function; in addition to forming gap junctions and "hemichannels", Cx43 provides a scaffold for signaling molecules. Hence, Cx43 actively participates in generation and modulation of cellular signals driving skeletal development and homeostasis. Pharmacological interference with Cx43 may in the future help remedy deterioration of bone quality occurring with aging, disuse and hormonal imbalances.
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Affiliation(s)
- Joseph P Stains
- Department of Orthopaedics, University of Maryland, School of Medicine, Baltimore, MD, United States
| | - Roberto Civitelli
- Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University in St. Louis, Campus Box 8301, 425 South Euclid, St. Louis, MO 63110, United States.
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