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Seal A, Hughes M, Wei F, Pugazhendhi AS, Ngo C, Ruiz J, Schwartzman JD, Coathup MJ. Sphingolipid-Induced Bone Regulation and Its Emerging Role in Dysfunction Due to Disease and Infection. Int J Mol Sci 2024; 25:3024. [PMID: 38474268 DOI: 10.3390/ijms25053024] [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: 02/09/2024] [Revised: 03/02/2024] [Accepted: 03/04/2024] [Indexed: 03/14/2024] Open
Abstract
The human skeleton is a metabolically active system that is constantly regenerating via the tightly regulated and highly coordinated processes of bone resorption and formation. Emerging evidence reveals fascinating new insights into the role of sphingolipids, including sphingomyelin, sphingosine, ceramide, and sphingosine-1-phosphate, in bone homeostasis. Sphingolipids are a major class of highly bioactive lipids able to activate distinct protein targets including, lipases, phosphatases, and kinases, thereby conferring distinct cellular functions beyond energy metabolism. Lipids are known to contribute to the progression of chronic inflammation, and notably, an increase in bone marrow adiposity parallel to elevated bone loss is observed in most pathological bone conditions, including aging, rheumatoid arthritis, osteoarthritis, and osteomyelitis. Of the numerous classes of lipids that form, sphingolipids are considered among the most deleterious. This review highlights the important primary role of sphingolipids in bone homeostasis and how dysregulation of these bioactive metabolites appears central to many chronic bone-related diseases. Further, their contribution to the invasion, virulence, and colonization of both viral and bacterial host cell infections is also discussed. Many unmet clinical needs remain, and data to date suggest the future use of sphingolipid-targeted therapy to regulate bone dysfunction due to a variety of diseases or infection are highly promising. However, deciphering the biochemical and molecular mechanisms of this diverse and extremely complex sphingolipidome, both in terms of bone health and disease, is considered the next frontier in the field.
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Affiliation(s)
- Anouska Seal
- Biionix Cluster, University of Central Florida, Orlando, FL 32827, USA
| | - Megan Hughes
- School of Biosciences, Cardiff University, Cardiff CF10 3AT, UK
| | - Fei Wei
- Biionix Cluster, University of Central Florida, Orlando, FL 32827, USA
- College of Medicine, University of Central Florida, Orlando, FL 32827, USA
| | - Abinaya S Pugazhendhi
- Biionix Cluster, University of Central Florida, Orlando, FL 32827, USA
- College of Medicine, University of Central Florida, Orlando, FL 32827, USA
| | - Christopher Ngo
- Biionix Cluster, University of Central Florida, Orlando, FL 32827, USA
- College of Medicine, University of Central Florida, Orlando, FL 32827, USA
| | - Jonathan Ruiz
- College of Medicine, University of Central Florida, Orlando, FL 32827, USA
| | | | - Melanie J Coathup
- Biionix Cluster, University of Central Florida, Orlando, FL 32827, USA
- College of Medicine, University of Central Florida, Orlando, FL 32827, USA
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2
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Li P, Sundh D, Ji B, Lappa D, Ye L, Nielsen J, Lorentzon M. Metabolic Alterations in Older Women With Low Bone Mineral Density Supplemented With Lactobacillus reuteri. JBMR Plus 2021; 5:e10478. [PMID: 33869994 PMCID: PMC8046097 DOI: 10.1002/jbm4.10478] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 02/03/2021] [Indexed: 12/13/2022] Open
Abstract
Osteoporosis and its associated fractures are highly prevalent in older women. Recent studies have shown that gut microbiota play important roles in regulating bone metabolism. A previous randomized controlled trial (RCT) found that supplementation with Lactobacillus reuteri ATCC PTA 6475 (L.reuteri) led to substantially reduced bone loss in older women with low BMD. However, the total metabolic effects of L. reuteri supplementation on older women are still not clear. In this study, a post hoc analysis (not predefined) of serum metabolomic profiles of older women from the previous RCT was performed to investigate the metabolic dynamics over 1 year and to evaluate the effects of L. reuteri supplementation on human metabolism. Distinct segregation of the L. reuteri and placebo groups in response to the treatment was revealed by partial least squares‐discriminant analysis. Although no individual metabolite was differentially and significantly associated with treatment after correction for multiple testing, 97 metabolites responded differentially at any one time point between L. reuteri and placebo groups (variable importance in projection score >1 and p value <0.05). These metabolites were involved in multiple processes, including amino acid, peptide, and lipid metabolism. Butyrylcarnitine was particularly increased at all investigated time points in the L. reuteri group compared with placebo, indicating that the effects of L. reuteri on bone loss are mediated through butyrate signaling. Furthermore, the metabolomic profiles in a case (low BMD) and control population (high BMD) of elderly women were analyzed to confirm the associations between BMD and the identified metabolites regulated by L. reuteri supplementation. The amino acids, especially branched‐chain amino acids, showed association with L. reuteri treatment and with low BMD in older women, and may serve as potential therapeutic targets. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
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Affiliation(s)
- Peishun Li
- Department of Biology and Biological Engineering Chalmers University of Technology Gothenburg Sweden
| | - Daniel Sundh
- Geriatric Medicine, Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy University of Gothenburg Gothenburg Sweden
| | - Boyang Ji
- Department of Biology and Biological Engineering Chalmers University of Technology Gothenburg Sweden
| | - Dimitra Lappa
- Department of Biology and Biological Engineering Chalmers University of Technology Gothenburg Sweden
| | - Lingqun Ye
- Department of Biology and Biological Engineering Chalmers University of Technology Gothenburg Sweden
| | - Jens Nielsen
- Department of Biology and Biological Engineering Chalmers University of Technology Gothenburg Sweden.,Novo Nordisk Foundation Center for Biosustainability Technical University of Denmark Kgs. Lyngby Denmark.,BioInnovation Institute Copenhagen Denmark
| | - Mattias Lorentzon
- Geriatric Medicine, Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy University of Gothenburg Gothenburg Sweden.,Region Västra Götaland, Geriatric Medicine Clinic Sahlgrenska University Hospital Mölndal Sweden.,Mary MacKillop Institute for Health Research Australian Catholic University Melbourne Victoria Australia
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Miyauchi S, Kitagaki J, Masumoto R, Imai A, Kobayashi K, Nakaya A, Kawai S, Fujihara C, Asano Y, Yamashita M, Yanagita M, Yamada S, Kitamura M, Murakami S. Sphingomyelin Phosphodiesterase 3 Enhances Cytodifferentiation of Periodontal Ligament Cells. J Dent Res 2016; 96:339-346. [DOI: 10.1177/0022034516677938] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Sphingomyelin phosphodiesterase 3 ( Smpd3), which encodes neutral sphingomyelinase 2 (nSMase2), is a key molecule for skeletal development as well as for the cytodifferentiation of odontoblasts and alveolar bone. However, the effects of nSMase2 on the cytodifferentiation of periodontal ligament (PDL) cells are still unclear. In this study, the authors analyzed the effects of Smpd3 on the cytodifferentiation of human PDL (HPDL) cells. The authors found that Smpd3 increases the mRNA expression of calcification-related genes, such as alkaline phosphatase (ALPase), type I collagen, osteopontin, Osterix (Osx), and runt-related transcription factor (Runx)-2 in HPDL cells. In contrast, GW4869, an inhibitor of nSMase2, clearly decreased the mRNA expression of ALPase, type I collagen, and osteocalcin in HPDL cells, suggesting that Smpd3 enhances HPDL cytodifferentiation. Next, the authors used exome sequencing to evaluate the genetic variants of Smpd3 in a Japanese population with aggressive periodontitis (AgP). Among 44 unrelated subjects, the authors identified a single nucleotide polymorphism (SNP), rs145616324, in Smpd3 as a putative genetic variant for AgP among Japanese people. Moreover, Smpd3 harboring this SNP did not increase the sphingomyelinase activity or mRNA expression of ALPase, type I collagen, osteopontin, Osx, or Runx2, suggesting that this SNP inhibits Smpd3 such that it has no effect on the cytodifferentiation of HPDL cells. These data suggest that Smpd3 plays a crucial role in maintaining the homeostasis of PDL tissue.
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Affiliation(s)
- S. Miyauchi
- Department of Periodontology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
| | - J. Kitagaki
- Department of Periodontology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
| | - R. Masumoto
- Department of Periodontology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
| | - A. Imai
- Department of Genome Informatics, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - K. Kobayashi
- Department of Genome Informatics, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
- Medical Solutions Division, NEC Corporation, Minato-ku, Tokyo, Japan
| | - A. Nakaya
- Department of Genome Informatics, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - S. Kawai
- Challenge to Intractable Oral Disease, Center for Frontier Oral Science, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
| | - C. Fujihara
- Challenge to Intractable Oral Disease, Center for Translational Dental Research, Osaka University Dental Hospital, Suita, Osaka, Japan
| | - Y. Asano
- Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - M. Yamashita
- Department of Periodontology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
| | - M. Yanagita
- Department of Periodontology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
| | - S. Yamada
- Department of Periodontology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
| | - M. Kitamura
- Department of Periodontology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
| | - S. Murakami
- Department of Periodontology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
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4
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During A, Penel G, Hardouin P. Understanding the local actions of lipids in bone physiology. Prog Lipid Res 2015; 59:126-46. [PMID: 26118851 DOI: 10.1016/j.plipres.2015.06.002] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Revised: 06/12/2015] [Accepted: 06/18/2015] [Indexed: 12/19/2022]
Abstract
The adult skeleton is a metabolically active organ system that undergoes continuous remodeling to remove old and/or stressed bone (resorption) and replace it with new bone (formation) in order to maintain a constant bone mass and preserve bone strength from micro-damage accumulation. In that remodeling process, cellular balances--adipocytogenesis/osteoblastogenesis and osteoblastogenesis/osteoclastogenesis--are critical and tightly controlled by many factors, including lipids as discussed in the present review. Interest in the bone lipid area has increased as a result of in vivo evidences indicating a reciprocal relationship between bone mass and marrow adiposity. Lipids in bones are usually assumed to be present only in the bone marrow. However, the mineralized bone tissue itself also contains small amounts of lipids which might play an important role in bone physiology. Fatty acids, cholesterol, phospholipids and several endogenous metabolites (i.e., prostaglandins, oxysterols) have been purported to act on bone cell survival and functions, the bone mineralization process, and critical signaling pathways. Thus, they can be regarded as regulatory molecules important in bone health. Recently, several specific lipids derived from membrane phospholipids (i.e., sphingosine-1-phosphate, lysophosphatidic acid and different fatty acid amides) have emerged as important mediators in bone physiology and the number of such molecules will probably increase in the near future. The present paper reviews the current knowledge about: (1°) bone lipid composition in both bone marrow and mineralized tissue compartments, and (2°) local actions of lipids on bone physiology in relation to their metabolism. Understanding the roles of lipids in bone is essential to knowing how an imbalance in their signaling pathways might contribute to bone pathologies, such as osteoporosis.
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Affiliation(s)
- Alexandrine During
- Université Lille 2, Laboratoire de Physiopathologie des maladies osseuses inflammatoires (PMOI), EA4490, Faculté de Chirurgie dentaire, Lille, France.
| | - Guillaume Penel
- Université Lille 2, Laboratoire de Physiopathologie des maladies osseuses inflammatoires (PMOI), EA4490, Faculté de Chirurgie dentaire, Lille, France
| | - Pierre Hardouin
- Université Lille 2, Laboratoire de Physiopathologie des maladies osseuses inflammatoires (PMOI), EA4490, Faculté de Chirurgie dentaire, Lille, France; Université ULCO, Laboratoire de Physiopathologie des maladies osseuses inflammatoires (PMOI), EA4490, Boulogne-sur-Mer, France
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5
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Alebrahim S, Khavandgar Z, Marulanda J, Murshed M. Inducible transient expression ofSmpd3prevents early lethality infro/fromice. Genesis 2014; 52:408-16. [DOI: 10.1002/dvg.22765] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Revised: 02/07/2014] [Accepted: 02/21/2014] [Indexed: 11/10/2022]
Affiliation(s)
| | | | | | - Monzur Murshed
- Faculty of Dentistry; McGill University; Montreal Quebec Canada
- Department of Medicine; McGill University; Montreal Quebec Canada
- Genetics Unit, Shriners Hospital for Children, McGill University; Montreal Quebec Canada
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6
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Abstract
Sphingomyelin phosphodiesterase 3 ( Smpd3) encodes a membrane-bound enzyme that cleaves sphingomyelin to generate several bioactive metabolites. A recessive mutation called fragilitas ossium ( fro) in the Smpd3 gene leads to impaired mineralization of bone and tooth extracellular matrix (ECM) in fro/fro mice. In teeth from fro/fro mice at various neonatal ages, radiography and light and electron microscopy showed delayed mantle dentin mineralization and a consequent delay in enamel formation as compared with that in control +/fro mice. These tooth abnormalities progressively improved with time. Immunohistochemistry showed expression of SMPD3 by dentin-forming odontoblasts. SMPD3 deficiency, however, did not affect the differentiation of these cells, as shown by osterix and dentin sialophosphoprotein expression. Using a transgenic mouse rescue model ( fro/fro; Col1a1-Smpd3) in which Smpd3 expression is driven by a murine Col1a1 promoter fragment active in osteoblasts and odontoblasts, we demonstrate a complete correction of the tooth mineralization delays. In conclusion, analysis of these data demonstrates that Smpd3 expression in odontoblasts is required for tooth mineralization.
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Coleman RM, Aguilera L, Quinones L, Lukashova L, Poirier C, Boskey A. Comparison of bone tissue properties in mouse models with collagenous and non-collagenous genetic mutations using FTIRI. Bone 2012; 51:920-8. [PMID: 22910579 PMCID: PMC3583571 DOI: 10.1016/j.bone.2012.08.110] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Revised: 08/02/2012] [Accepted: 08/04/2012] [Indexed: 12/18/2022]
Abstract
Understanding how the material properties of bone tissue from the various forms of osteogenesis imperfecta (OI) differ will allow us to tailor treatment regimens for affected patients. To this end, we characterized the bone structure and material properties of two mouse models of OI, the osteogenesis imperfecta mouse (oim/oim) and fragilitas ossium (fro/fro), in which bone fragility is due to a genetic defect in collagen type I and a defect in osteoblast matrix mineralization, respectively. Bones from 3 to 6 month old animals were examined using Fourier transform infrared spectroscopic imaging (FTIRI), microcomputed tomography (micro-CT), histology, and biochemical analysis. The attributes of oim/oim bone tissue were relatively constant over time when compared to wild type animals. The mineral density in oim/oim cortices and trabecular bone was higher than wild type while the bones had thinner cortices and fewer trabeculae that were thinner and more widely spaced. The fro/fro animals exhibited osteopenic attributes at 3 months. However, by 6 months, their spectroscopic and geometric properties were similar to wild type animals. Despite the lack of a specific collagen defect in fro/fro mice, both fro/fro and oim/oim genotypes exhibited abnormal collagen crosslinking as determined by FTIRI at both time points. These results demonstrate that abnormal extracellular matrix assembly plays a role in the bone fragility in both of these models.
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Affiliation(s)
- Rhima M. Coleman
- Hospital for Special Surgery, Cornell University-Weill Medical College, New York, NY, USA
| | - Laura Aguilera
- LaGuardia Community College of the City University of New York, New York, NY, USA
| | - Layla Quinones
- LaGuardia Community College of the City University of New York, New York, NY, USA
| | - Lyudamila Lukashova
- Hospital for Special Surgery, Cornell University-Weill Medical College, New York, NY, USA
| | | | - Adele Boskey
- Hospital for Special Surgery, Cornell University-Weill Medical College, New York, NY, USA
- Corresponding author at: Hospital for Special Surgery, Caspary Research Building, 535 E. 70th Street, New York, NY 10021, USA. Fax: + 1 212 472 5331. , (A. Boskey)
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Vital SO, Gaucher C, Bardet C, Rowe P, George A, Linglart A, Chaussain C. Tooth dentin defects reflect genetic disorders affecting bone mineralization. Bone 2012; 50:989-97. [PMID: 22296718 PMCID: PMC3345892 DOI: 10.1016/j.bone.2012.01.010] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 01/06/2012] [Accepted: 01/14/2012] [Indexed: 01/27/2023]
Abstract
Several genetic disorders affecting bone mineralization may manifest during dentin mineralization. Dentin and bone are similar in several aspects, especially pertaining to the composition of the extracellular matrix (ECM) which is secreted by well-differentiated odontoblasts and osteoblasts, respectively. However, unlike bone, dentin is not remodelled and is not involved in the regulation of calcium and phosphate metabolism. In contrast to bone, teeth are accessible tissues with the shedding of deciduous teeth and the extractions of premolars and third molars for orthodontic treatment. The feasibility of obtaining dentin makes this a good model to study biomineralization in physiological and pathological conditions. In this review, we focus on two genetic diseases that disrupt both bone and dentin mineralization. Hypophosphatemic rickets is related to abnormal secretory proteins involved in the ECM organization of both bone and dentin, as well as in the calcium and phosphate metabolism. Osteogenesis imperfecta affects proteins involved in the local organization of the ECM. In addition, dentin examination permits evaluation of the effects of the systemic treatment prescribed to hypophosphatemic patients during growth. In conclusion, dentin constitutes a valuable tool for better understanding of the pathological processes affecting biomineralization.
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Affiliation(s)
- S. Opsahl Vital
- Dental School University Paris Descartes PRES Sorbonne Paris Cité, EA 2496, Montrouge, F-92120, France
- AP-HP, Odontology Department, Hôpitaux Universitaires Paris Nord Val de Seine (Bretonneau- Louis Mourier), F-75018, France
- Centre de référence des maladies rares du métabolisme du phosphore et du calcium, Kremlin Bicêtre, AP-HP, F-94275, France
| | - C. Gaucher
- Dental School University Paris Descartes PRES Sorbonne Paris Cité, EA 2496, Montrouge, F-92120, France
- AP-HP, Odontology Department, Hôpital Albert Chennevier, Créteil, F-94010, France
- Centre de référence des maladies rares du métabolisme du phosphore et du calcium, Kremlin Bicêtre, AP-HP, F-94275, France
| | - C. Bardet
- Dental School University Paris Descartes PRES Sorbonne Paris Cité, EA 2496, Montrouge, F-92120, France
| | - P.S. Rowe
- The Kidney Institute, University of Kansas Medical Center, Kansas City, KS, USA
| | - A. George
- Department of Oral Biology, University of Illinois in Chicago, Illinois 60612, USA
| | - A. Linglart
- Inserm, U986 Hôpital St Vincent de Paul AP-HP, Paris, F-75014, France
- Centre de référence des maladies rares du métabolisme du phosphore et du calcium, Kremlin Bicêtre, AP-HP, F-94275, France
| | - C. Chaussain
- Dental School University Paris Descartes PRES Sorbonne Paris Cité, EA 2496, Montrouge, F-92120, France
- AP-HP, Odontology Department, Hôpitaux Universitaires Paris Nord Val de Seine (Bretonneau- Louis Mourier), F-75018, France
- Centre de référence des maladies rares du métabolisme du phosphore et du calcium, Kremlin Bicêtre, AP-HP, F-94275, France
- Corresponding author at: Dental school University Paris Descartes PRES Sorbonne Paris Cité, EA 2496, Montrouge, France 2120. Fax: +33 158076724. (C. Chaussain)
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Khavandgar Z, Poirier C, Clarke CJ, Li J, Wang N, McKee MD, Hannun YA, Murshed M. A cell-autonomous requirement for neutral sphingomyelinase 2 in bone mineralization. ACTA ACUST UNITED AC 2011; 194:277-89. [PMID: 21788370 PMCID: PMC3144407 DOI: 10.1083/jcb.201102051] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
nSMase2, which cleaves sphingomyelin to generate bioactive lipids, is required for chondrocyte apoptosis and, cell autonomously, for bone mineralization. A deletion mutation called fro (fragilitas ossium) in the murine Smpd3 (sphingomyelin phosphodiesterase 3) gene leads to a severe skeletal dysplasia. Smpd3 encodes a neutral sphingomyelinase (nSMase2), which cleaves sphingomyelin to generate bioactive lipid metabolites. We examined endochondral ossification in embryonic day 15.5 fro/fro mouse embryos and observed impaired apoptosis of hypertrophic chondrocytes and severely undermineralized cortical bones in the developing skeleton. In a recent study, it was suggested that nSMase2 activity in the brain regulates skeletal development through endocrine factors. However, we detected Smpd3 expression in both embryonic and postnatal skeletal tissues in wild-type mice. To investigate whether nSMase2 plays a cell-autonomous role in these tissues, we examined the in vitro mineralization properties of fro/fro osteoblast cultures. fro/fro cultures mineralized less than the control osteoblast cultures. We next generated fro/fro;Col1a1-Smpd3 mice, in which osteoblast-specific expression of Smpd3 corrected the bone abnormalities observed in fro/fro embryos without affecting the cartilage phenotype. Our data suggest tissue-specific roles for nSMase2 in skeletal tissues.
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Affiliation(s)
- Zohreh Khavandgar
- Faculty of Dentistry, McGill University, Montreal, Quebec QC H3A 1A4, Canada
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Goldberg M, Kulkarni AB, Young M, Boskey A. Dentin: structure, composition and mineralization. Front Biosci (Elite Ed) 2011; 3:711-35. [PMID: 21196346 DOI: 10.2741/e281] [Citation(s) in RCA: 391] [Impact Index Per Article: 30.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
We review firstly the specificities of the different types of dentin present in mammalian teeth. The outer layers include the mantle dentin, the Tomes' granular and the hyaline Hopewell-Smith's layers. Circumpulpal dentin forming the bulk of the tooth, comprises intertubular and peritubular dentin. In addition to physiological primary and secondary dentin formation, reactionary dentin is produced in response to pathological events. Secondly, we evaluate the role of odontoblasts in dentin formation, their implication in the synthesis and secretion of type I collagen fibrils and non-collagenous molecules. Thirdly, we study the composition and functions of dentin extracellular matrix (ECM) molecules implicated in dentinogenesis. As structural proteins they are mineralization promoters or inhibitors. They are also signaling molecules. Three different forms of dentinogenesis are identified: i) matrix vesicles are implicated in early dentin formation, ii) collagen and some proteoglycans are involved in the formation of predentin, further transformed into intertubular dentin, iii) the distal secretion of some non-collagenous ECM molecules and some serum proteins contribute to the formation of peritubular dentin.
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Affiliation(s)
- Michel Goldberg
- UMR-S 747, INSERM, Universite Paris Descartes, Paris, France.
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11
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Sun HH, Jin T, Yu Q, Chen FM. Biological approaches toward dental pulp regeneration by tissue engineering. J Tissue Eng Regen Med 2010; 5:e1-16. [PMID: 21413154 DOI: 10.1002/term.369] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2010] [Accepted: 08/31/2010] [Indexed: 01/07/2023]
Abstract
Root canal therapy has been the predominant approach in endodontic treatment, wherein the entire pulp is cleaned out and replaced with a gutta-percha filling. However, living pulp is critical for the maintenance of tooth homeostasis and essential for tooth longevity. An ideal form of therapy, therefore, might consist of regenerative approaches in which diseased/necrotic pulp tissues are removed and replaced with regenerated pulp tissues to revitalize the teeth. Dental pulp regeneration presents one of the most challenging issues in regenerative dentistry due to the poor intrinsic ability of pulp tissues for self-healing and regrowth. With the advent of modern tissue engineering and the discovery of dental stem cells, biological therapies have paved the way to utilize stem cells, delivered or internally recruited, to generate dental pulp tissues, where growth factors and a series of dentine extracellular matrix molecules are key mediators that regulate the complex cascade of regeneration events to be faithfully fulfilled.
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Affiliation(s)
- Hai-Hua Sun
- Department of Operative Dentistry and Endodontics, School of Stomatology, Fourth Military Medical University, Xi'an 710032, Shaanxi, People's Republic of China
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12
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Schulze J, Seitz S, Saito H, Schneebauer M, Marshall RP, Baranowsky A, Busse B, Schilling AF, Friedrich FW, Albers J, Spiro AS, Zustin J, Streichert T, Ellwanger K, Niehrs C, Amling M, Baron R, Schinke T. Negative regulation of bone formation by the transmembrane Wnt antagonist Kremen-2. PLoS One 2010; 5:e10309. [PMID: 20436912 PMCID: PMC2860505 DOI: 10.1371/journal.pone.0010309] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2009] [Accepted: 03/24/2010] [Indexed: 12/17/2022] Open
Abstract
Wnt signalling is a key pathway controlling bone formation in mice and humans. One of the regulators of this pathway is Dkk1, which antagonizes Wnt signalling through the formation of a ternary complex with the transmembrane receptors Krm1/2 and Lrp5/6, thereby blocking the induction of Wnt signalling by the latter ones. Here we show that Kremen-2 (Krm2) is predominantly expressed in bone, and that its osteoblast-specific over-expression in transgenic mice (Col1a1-Krm2) results in severe osteoporosis. Histomorphometric analysis revealed that osteoblast maturation and bone formation are disturbed in Col1a1-Krm2 mice, whereas bone resorption is increased. In line with these findings, primary osteoblasts derived from Col1a1-Krm2 mice display a cell-autonomous differentiation defect, impaired canonical Wnt signalling and decreased production of the osteoclast inhibitory factor Opg. To determine whether the observed effects of Krm2 on bone remodeling are physiologically relevant, we analyzed the skeletal phenotype of 24 weeks old Krm2-deficient mice and observed high bone mass caused by a more than three-fold increase in bone formation. Taken together, these data identify Krm2 as a regulator of bone remodeling and raise the possibility that antagonizing KRM2 might prove beneficial in patients with bone loss disorders.
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Affiliation(s)
- Jochen Schulze
- Institute of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Sebastian Seitz
- Institute of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Hiroaki Saito
- Harvard School of Dental Medicine and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Michael Schneebauer
- Institute of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Robert P. Marshall
- Institute of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Anke Baranowsky
- Institute of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Bjoern Busse
- Institute of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Arndt F. Schilling
- Institute of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Felix W. Friedrich
- Institute of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Joachim Albers
- Institute of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Alexander S. Spiro
- Institute of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Jozef Zustin
- Institute of Pathology, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Thomas Streichert
- Department of Clinical Chemistry, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Kristina Ellwanger
- Division of Molecular Embryology, Research Program Cell and Tumor Biology of the German Cancer Research Center and the Center for Molecular Biology of the University of Heidelberg (DKFZ-ZMBH) Alliance, German Cancer Research Center, Heidelberg, Germany
| | - Christof Niehrs
- Division of Molecular Embryology, Research Program Cell and Tumor Biology of the German Cancer Research Center and the Center for Molecular Biology of the University of Heidelberg (DKFZ-ZMBH) Alliance, German Cancer Research Center, Heidelberg, Germany
| | - Michael Amling
- Institute of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Roland Baron
- Harvard School of Dental Medicine and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Thorsten Schinke
- Institute of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg, Germany
- * E-mail:
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Chae YM, Heo SH, Kim JY, Lee JM, Ryoo HM, Cho JY. Upregulation of smpd3 via BMP2 stimulation and Runx2. BMB Rep 2009; 42:86-90. [PMID: 19250608 DOI: 10.5483/bmbrep.2009.42.2.086] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Deletion of smpd3 induces osteogenesis and dentinogenesis imperfecta in mice. smpd3 is highly elevated in the parietal bones of developing mouse calvaria, but not in sutural mesenchymes. Here, we examine the mechanism of smpd3 regulation, which involves BMP2 stimulation of Runx2. smpd3 mRNA expression increased in response to BMP2 treatment and Runx2 transfection in C2C12 cells. The Runx2-responsive element (RRE) encoded within the -562 to -557 region is important for activation of the smpd3 promoter by Runx2. Electrophoretic mobility shift assays revealed that Runx2 binds strongly to the -355 to -350 RRE and less strongly to the -562 to -557 site. Thus, the smpd3 promoter is activated by BMP2 and is directly regulated by the Runx2 transcription factor. This novel description of smpd3 regulation will aid further studies of bone development and osteogenesis.
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Affiliation(s)
- Young-Mi Chae
- Department of Biochemistry, School of Dentistry, Kyungpook National University, Daegu, Korea
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