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Nouet J, Himelman E, Lahey KC, Zhao Q, Fraidenraich D. Connexin-43 reduction prevents muscle defects in a mouse model of manifesting Duchenne muscular dystrophy female carriers. Sci Rep 2020; 10:5683. [PMID: 32231219 PMCID: PMC7105483 DOI: 10.1038/s41598-020-62844-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 03/18/2020] [Indexed: 12/22/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a severe X-linked neuromuscular disorder that affects males. However, 8% of female carriers are symptomatic and underrepresented in research due to the lack of animal models. We generated a symptomatic mouse model of DMD carriers via injection of mdx (murine DMD) embryonic stem cells (ESCs) into wild-type (WT) blastocysts (mdx/WT chimera). mdx/WT chimeras developed cardiomyopathic features and dystrophic skeletal muscle phenotypes including elevated mononuclear invasion, central nucleation, fibrosis and declined forelimb grip strength. The disease was accompanied by connexin-43 (Cx43) aberrantly enhanced in both cardiac and skeletal muscles and remodeled in the heart. Genetic reduction of Cx43-copy number in mdx/WT-Cx43(+/-) chimeras protected them from both cardiac and skeletal muscle fiber damage. In dystrophic skeletal muscle, Cx43 expression was not seen in the fibers but in adjacent F4/80+ mononuclear cells. Ethidium Bromide uptake in purified F4/80+/CD11b+ mdx macrophages revealed functional activity of Cx43, which was inhibited by administration of Gap19 peptide mimetic, a Cx43 hemichannel-specific inhibitor. Thus, we suggest that Cx43 reduction in symptomatic DMD carrier mice leads to prevention of Cx43 remodeling in the heart and prevention of aberrant Cx43 hemichannel activity in the skeletal muscle macrophages neighboring Cx43 non-expressing fibers.
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Affiliation(s)
- Julie Nouet
- Department of Cell Biology and Molecular Medicine, Rutgers Biomedical and Health Sciences, New Jersey Medical School, Newark, NJ, USA
| | - Eric Himelman
- Department of Cell Biology and Molecular Medicine, Rutgers Biomedical and Health Sciences, New Jersey Medical School, Newark, NJ, USA
| | - Kevin C Lahey
- Department of Cell Biology and Molecular Medicine, Rutgers Biomedical and Health Sciences, New Jersey Medical School, Newark, NJ, USA
| | - Qingshi Zhao
- Department of Cell Biology and Molecular Medicine, Rutgers Biomedical and Health Sciences, New Jersey Medical School, Newark, NJ, USA
| | - Diego Fraidenraich
- Department of Cell Biology and Molecular Medicine, Rutgers Biomedical and Health Sciences, New Jersey Medical School, Newark, NJ, USA.
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McClure MJ, Ramey AN, Rashid M, Boyan BD, Schwartz Z. Integrin-α7 signaling regulates connexin 43, M-cadherin, and myoblast fusion. Am J Physiol Cell Physiol 2019; 316:C876-C887. [PMID: 30892939 DOI: 10.1152/ajpcell.00282.2018] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Regenerative medicine treatments for severe skeletal muscle injuries are limited, resulting in persistent functional deficits. Clinical options include neglecting the wound with the expectation that fibrosis will develop or using an autologous muscle graft with minimal functional improvement. A regenerative matrix can be used, but muscle fiber development on these matrices remains a challenge in vivo. Here, we explored the fundamental mechanisms that mediate cell-substrate signaling and its effect on cell-cell communication during myoblast fusion and tube formation to improve outcomes following implantation of matrices used to stimulate muscle regeneration. We previously reported that integrin-α7 was increased on anisotropic biomaterials, suggesting a role for α7β1 signaling in myoblast communication via connexin 43 and M-cadherin. Our results demonstrated that α7 silencing blocked expression of myogenic differentiation factor 1 (Myod), myogenin (Myog), myogenic factor 6 (Myf6), myosin heavy chain type 1 (Myh1), and transmembrane protein 8c (Tmem8c), indicating that myoblast fusion was inhibited. Expression of α5 and M-cadherin decreased but β1 and connexin 43 increased. We examined protein production and observed reduced extracellular-signal regulated kinase 1/2 (ERK) in α7-silenced cells that correlated with upregulation of connexin 43 and M-cadherin, suggesting a compensatory pathway. These results indicate that α7 signaling plays a critical role in ex vivo fusion and implicates a relationship with connexin 43 and M-cadherin.
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Affiliation(s)
- Michael J McClure
- Department of Biomedical Engineering, College of Engineering, Virginia Commonwealth University , Richmond, Virginia
| | - Allison N Ramey
- Department of Biomedical Engineering, College of Engineering, Virginia Commonwealth University , Richmond, Virginia
| | - Mashaba Rashid
- Department of Biomedical Engineering, College of Engineering, Virginia Commonwealth University , Richmond, Virginia
| | - Barbara D Boyan
- Department of Biomedical Engineering, College of Engineering, Virginia Commonwealth University , Richmond, Virginia.,Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology , Atlanta, Georgia
| | - Zvi Schwartz
- Department of Biomedical Engineering, College of Engineering, Virginia Commonwealth University , Richmond, Virginia.,Department of Periodontics, University of Texas Health Sciences Center at San Antonio , San Antonio, Texas
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Zhang XF, Cui X. Connexin 43: Key roles in the skin. Biomed Rep 2017; 6:605-611. [PMID: 28584630 DOI: 10.3892/br.2017.903] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 03/17/2017] [Indexed: 12/26/2022] Open
Abstract
Gap junctions are tightly packed intercellular channels that serve a common purpose of allowing the intercellular exchange of small metabolites, second messengers and electrical signals. Connexins (Cxs) are gap junction proteins. Currently, 20 and 21 members of Cxs have been characterized in mice and humans, respectively. Connexin 43 (Cx43) is the most ubiquitously expressed type of Cx in the skin. It is produced by various different types of skin cell, such as keratinocytes, fibroblasts, endothelial and basal cells, melanocytes and dermal papilla cells. At present, more evidence indicates that Cx43 has an important role in skin repair and skin tumor development, as well as in skin cell invasion and metastasis. In this review, current knowledge regarding the regulation and function of Cx43 is summarized and the therapeutic potential of regulating Cx43 activity is discussed.
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Affiliation(s)
- Xiao-Fei Zhang
- Department of Biological Sciences and Biotechnology, School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan, Hubei 430070, P.R. China
| | - Xiaofeng Cui
- Department of Biological Sciences and Biotechnology, School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan, Hubei 430070, P.R. China
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Ikeda E, Goto T, Gunjigake K, Kuroishi K, Ueda M, Kataoka S, Toyono T, Nakatomi M, Seta Y, Kitamura C, Nishihara T, Kawamoto T. Expression of Vesicular Nucleotide Transporter in Rat Odontoblasts. Acta Histochem Cytochem 2016; 49:21-8. [PMID: 27006518 PMCID: PMC4794551 DOI: 10.1267/ahc.15022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Accepted: 11/25/2015] [Indexed: 01/29/2023] Open
Abstract
Several theories have been proposed regarding pain transmission mechanisms in tooth. However, the exact signaling mechanism from odontoblasts to pulp nerves remains to be clarified. Recently, ATP-associated pain transmission has been reported, but it is unclear whether ATP is involved in tooth pain transmission. In the present study, we focused on the vesicular nucleotide transporter (VNUT), a transporter of ATP into vesicles, and examined whether VNUT was involved in ATP release from odontoblasts. We examined the expression of VNUT in rat pulp by RT-PCR and immunostaining. ATP release from cultured odontoblast-like cells with heat stimulation was evaluated using ATP luciferase methods. VNUT was expressed in pulp tissue, and the distribution of VNUT-immunopositive vesicles was confirmed in odontoblasts. In odontoblasts, some VNUT-immunopositive vesicles were colocalized with membrane fusion proteins. Additionally P2X3, an ATP receptor, immunopositive axons were distributed between odontoblasts. The ATP release by thermal stimulation from odontoblast-like cells was inhibited by the addition of siRNA for VNUT. These findings suggest that cytosolic ATP is transported by VNUT and that the ATP in the vesicles is then released from odontoblasts to ATP receptors on axons. ATP vesicle transport in odontoblasts seems to be a key mechanism for signal transduction from odontoblasts to axons in the pulp.
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Affiliation(s)
- Erina Ikeda
- Division of Orofacial Functions and Orthodontics, Kyushu Dental University
| | - Tetsuya Goto
- Department of Oral Anatomy and Cell Biology, Kagoshima University
| | - Kaori Gunjigake
- Division of Orofacial Functions and Orthodontics, Kyushu Dental University
| | - Kayoko Kuroishi
- Division of Orofacial Functions and Orthodontics, Kyushu Dental University
| | - Masae Ueda
- Division of Orofacial Functions and Orthodontics, Kyushu Dental University
| | | | | | | | - Yuji Seta
- Division of Anatomy, Kyushu Dental University
| | - Chiaki Kitamura
- Division of Endodontics and Restorative Dentistry, Kyushu Dental University
| | - Tatsuji Nishihara
- Division of Infections and Molecular Biology, Kyushu Dental University
| | - Tatsuo Kawamoto
- Division of Orofacial Functions and Orthodontics, Kyushu Dental University
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Merrifield PA, Laird DW. Connexins in skeletal muscle development and disease. Semin Cell Dev Biol 2016; 50:67-73. [DOI: 10.1016/j.semcdb.2015.12.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 12/01/2015] [Indexed: 11/30/2022]
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