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Al-Jazzar A, Javaheri B, Prideaux M, Boyde A, Scudamore CL, Cherifi C, Hay E, Hopkinson M, Boyd M, Cohen-Solal M, Farquharson C, Pitsillides AA. Dmp1 Promoter-Driven Diphtheria Toxin Receptor Transgene Expression Directs Unforeseen Effects in Multiple Tissues. Int J Mol Sci 2016; 18:E29. [PMID: 28035954 PMCID: PMC5297664 DOI: 10.3390/ijms18010029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 12/13/2016] [Accepted: 12/15/2016] [Indexed: 01/16/2023] Open
Abstract
Mice harbouring a dentin matrix protein 1 (Dmp1) promoter-driven human diphtheria toxin (DT) receptor (HDTR) transgene (Tg) have recently been used to attain targeted ablation of osteocytes by diphtheria toxin (DT) treatment in order to define osteocyte function. Use of these Tg mice has asserted mechano- and novel paracrine regulatory osteocyte functions. To explore osteocyte roles fully, we sought to confirm the selectivity of DT effects in these transgenic mice. However, our findings revealed incomplete DT-induced osteocyte ablation, prevalent HDTR misexpression, as well as more prominent histopathological DT-induced changes in multiple organs in Tg than in wild-type (WT) littermate mice. Mechanistic evidence for DT action, via prominent regulation of phosphorylation status of elongation factor-2 (EF-2), was also found in many non-skeletal tissues in Tg mice; indicative of direct "off-target" DT action. Finally, very rapid deterioration in health and welfare status in response to DT treatment was observed in these Tg when compared to WT control mice. Together, these data lead us to conclude that alternative models for osteocyte ablation should be sought and caution be exercised when drawing conclusions from experiments using these Tg mice alone.
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Affiliation(s)
- Ahmed Al-Jazzar
- Skeletal Biology Group, Comparative Biomedical Sciences, Royal Veterinary College, Royal College Street, London NW1 0TU, UK.
| | - Behzad Javaheri
- Skeletal Biology Group, Comparative Biomedical Sciences, Royal Veterinary College, Royal College Street, London NW1 0TU, UK.
| | - Matt Prideaux
- Orthopaedics & Trauma, University of Adelaide, Adelaide, SA 5005, Australia.
| | - Alan Boyde
- Dental Physical Sciences, Institute of Dentistry, Queen Mary University of London, Mile End Campus, London E1 4NS, UK.
| | - Cheryl L Scudamore
- Mary Lyon Centre, MRC Harwell, Science & Innovation Campus, Oxfordshire OX11 0RD, UK.
| | - Chahrazad Cherifi
- Inserm U1132 & Université Sorbonne Paris Cité-Diderot, Rheumatology, Hôpital Lariboisière, Paris 75010, France.
| | - Eric Hay
- Inserm U1132 & Université Sorbonne Paris Cité-Diderot, Rheumatology, Hôpital Lariboisière, Paris 75010, France.
| | - Mark Hopkinson
- Skeletal Biology Group, Comparative Biomedical Sciences, Royal Veterinary College, Royal College Street, London NW1 0TU, UK.
| | - Michael Boyd
- Skeletal Biology Group, Comparative Biomedical Sciences, Royal Veterinary College, Royal College Street, London NW1 0TU, UK.
| | - Martine Cohen-Solal
- Inserm U1132 & Université Sorbonne Paris Cité-Diderot, Rheumatology, Hôpital Lariboisière, Paris 75010, France.
| | - Colin Farquharson
- Roslin Institute, University of Edinburgh, Division of Developmental Biology, Easter Bush, Midlothian EH25 9RG, UK.
| | - Andrew A Pitsillides
- Skeletal Biology Group, Comparative Biomedical Sciences, Royal Veterinary College, Royal College Street, London NW1 0TU, UK.
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Fujikawa K, Yokohama-Tamaki T, Morita T, Baba O, Qin C, Shibata S. An in situ hybridization study of perlecan, DMP1, and MEPE in developing condylar cartilage of the fetal mouse mandible and limb bud cartilage. Eur J Histochem 2015; 59:2553. [PMID: 26428891 PMCID: PMC4598603 DOI: 10.4081/ejh.2015.2553] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 08/25/2015] [Accepted: 08/30/2015] [Indexed: 11/23/2022] Open
Abstract
The main purpose of this in situ hybridization study was to investigate mRNA expression of three bone/cartilage matrix components (perlecan, DMP1, and MEPE) in developing primary (tibial) and secondary (condylar) cartilage. Perlecan mRNA expression was first detected in newly formed chondrocytes in tibial cartilage at E13.0, but this expression decreased in hypertrophic chondrocytes at E14.0. In contrast, at E15.0, perlecan mRNA was first detected in the newly formed chondrocytes of condylar cartilage; these chondrocytes had characteristics of hypertrophic chondrocytes, which confirmed the previous observation that progenitor cells of developing secondary cartilage rapidly differentiate into hypertrophic chondrocytes. DMP1 mRNA was detected in many chondrocytes within the lower hypertrophic cell zone in tibial cartilage at E14.0. In contrast, DMP1 mRNA expression was only transiently detected in a few chondrocytes of condylar cartilage at E15.0. Thus, DMP1 may be less important in the developing condylar cartilage than in the tibial cartilage. Another purpose of this study was to test the hypothesis that MEPE may be a useful marker molecule for cartilage. MEPE mRNA was not detected in any chondrocytes in either tibial or condylar cartilage; however, MEPE immunoreactivity was detected throughout the cartilage matrix. Western immunoblot analysis demonstrated that MEPE antibody recognized two bands, one of 67 kDa and another of 59 kDa, in cartilage-derived samples. Thus MEPE protein may gradually accumulate in the cartilage, even though mRNA expression levels were below the limits of detection of in situ hybridization. Ultimately, we could not designate MEPE as a marker molecule for cartilage, and would modify our original hypothesis.
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Shimizu O, Yasumitsu T, Shiratsuchi H, Oka S, Watanabe T, Saito T, Yonehara Y. Immunolocalization of FGF-2, -7, -8, -10 and FGFR-1-4 during regeneration of the rat submandibular gland. J Mol Histol 2015; 46:421-9. [PMID: 26173945 DOI: 10.1007/s10735-015-9631-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 07/07/2015] [Indexed: 01/13/2023]
Abstract
Fibroblast growth factors (FGFs) and their receptors (FGFRs) play important roles in the development of the submandibular gland. Although regeneration of submandibular glands follows a similar process to their development, it is unknown how FGFs and FGFRs are distributed during regeneration of submandibular gland. The aim of this study was to determine the localization of FGFs and FGFRs during such regenerative processes. After 7 days' obstruction, the submandibular glands were collected at days 0, 1, 3, 7, 11 and 14 after duct release to study regeneration. The regenerative processes of the submandibular gland were investigated by immunohistochemistry for FGF-2, 7, 8, 10 and FGFR-1-4. Immunohistochemical staining revealed that FGF-2 was moderately expressed in the epithelial cells of duct-like structures (DLS) and newly formed acinar cells (NFAC) at days 0-7, and strongly in intercalated duct (ICD) at control gland and Day 7-14. FGF-7 was localized moderately in NFAC and DLS. FGF-8 was localized moderately in the epithelial cells of DLS during regeneration. Strong positive immunoreactions for FGF-10 were found in NFAC and the epithelial cells of DLS during regeneration, as well as the ICD and lateral surfaces of the maturing acinar cells (MAC). FGFR-1 was expressed moderately in the ICD, and weakly in the NFAC and MAC. Positive immunoreactions for FGFR-2 were not observed during regeneration. Additionally, FGFR-4 was detected strongly in the ICD and slightly in NFAC. These findings suggest that FGF-2, -7, -8 and -10 play important roles in NFAC, MAC, and DLS through FGFR-1 and -4 during regeneration of submandibular gland.
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Affiliation(s)
- Osamu Shimizu
- Department of Oral and Maxillofacial Surgery, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo, 101-8310, Japan,
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Cryopreserved dentin matrix as a scaffold material for dentin-pulp tissue regeneration. Biomaterials 2014; 35:4929-39. [DOI: 10.1016/j.biomaterials.2014.03.016] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2013] [Accepted: 03/10/2014] [Indexed: 11/21/2022]
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Yang J, Wan C, Nie S, Jian S, Sun Z, Zhang L, Chen Z. Localization of Beclin1 in mouse developing tooth germs: possible implication of the interrelation between autophagy and apoptosis. J Mol Histol 2013; 44:619-27. [DOI: 10.1007/s10735-013-9518-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2013] [Accepted: 06/12/2013] [Indexed: 12/01/2022]
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