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Bianchi DW, Brennan PF, Chiang MF, Criswell LA, D'Souza RN, Gibbons GH, Gilman JK, Gordon JA, Green ED, Gregurick S, Hodes RJ, Kilmarx PH, Koob GF, Koroshetz WJ, Langevin HM, Lorsch JR, Marrazzo JM, Pérez-Stable EJ, Rathmell WK, Rodgers GP, Rutter JL, Simoni JM, Tromberg BJ, Tucci DL, Volkow ND, Woychik R, Zenk SN, Kozlowski E, Peterson RS, Ginsburg GS, Denny JC. The All of Us Research Program is an opportunity to enhance the diversity of US biomedical research. Nat Med 2024; 30:330-333. [PMID: 38374344 DOI: 10.1038/s41591-023-02744-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2024]
Affiliation(s)
- Diana W Bianchi
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | | | - Michael F Chiang
- National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Lindsey A Criswell
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Rena N D'Souza
- National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - Gary H Gibbons
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - James K Gilman
- Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | - Joshua A Gordon
- National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Eric D Green
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Susan Gregurick
- Office of Data Science Strategy, National Institutes of Health, Bethesda, MD, USA
| | - Richard J Hodes
- National Institute on Aging, National Institutes of Health, Bethesda, MD, USA
| | - Peter H Kilmarx
- Fogarty International Center, National Institutes of Health, Bethesda, MD, USA
| | - George F Koob
- National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA
| | - Walter J Koroshetz
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Helene M Langevin
- National Center for Complementary and Integrative Health, National Institutes of Health, Bethesda, MD, USA
| | - Jon R Lorsch
- National Institute of General Medical Sciences, National Institutes of Health, Bethesda, MD, USA
| | - Jeanne M Marrazzo
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Eliseo J Pérez-Stable
- National Institute on Minority Health and Health Disparities, National Institutes of Health, Bethesda, MD, USA
| | - W Kimryn Rathmell
- National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Griffin P Rodgers
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Joni L Rutter
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, USA
| | - Jane M Simoni
- Offices of the Director and Behavioral and Social Sciences Research, National Institutes of Health, Bethesda, MD, USA
| | - Bruce J Tromberg
- National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
| | - Debara L Tucci
- National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
| | - Nora D Volkow
- National Institute of Drug Abuse, National Institutes of Health, Bethesda, MD, USA
| | - Rick Woychik
- National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC, USA
| | - Shannon N Zenk
- National Institute of Nursing Research, National Institutes of Health, Bethesda, MD, USA
| | - Elyse Kozlowski
- All of Us Research Program, National Institutes of Health, Bethesda, MD, USA
| | - Rachele S Peterson
- All of Us Research Program, National Institutes of Health, Bethesda, MD, USA
| | - Geoffrey S Ginsburg
- All of Us Research Program, National Institutes of Health, Bethesda, MD, USA
| | - Joshua C Denny
- All of Us Research Program, National Institutes of Health, Bethesda, MD, USA.
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D'Souza RN, King LM, Webster-Cyriaque J, Shum L, Fischer DJ. Practice-Based Research Integrating Multidisciplinary Experiences in Dental Schools for culture change: Increasing clinical research capacity through dental education. J Am Dent Assoc 2023; 154:1037-1040. [PMID: 38008524 DOI: 10.1016/j.adaj.2023.10.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 10/03/2023] [Indexed: 11/28/2023]
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3
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Reddy MS, D'Souza RN, Webster-Cyriaque J. A Call for More Oral Health Research in Primary Care. JAMA 2023; 330:1629-1630. [PMID: 37934228 DOI: 10.1001/jama.2023.22005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2023]
Affiliation(s)
- Michael S Reddy
- UCSF School of Dentistry, Oral Health Affairs, University of California, San Francisco
| | - Rena N D'Souza
- National Institute of Dental and Craniofacial Research, Section on Craniofacial Genetic Disorders, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland
| | - Jennifer Webster-Cyriaque
- National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland
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4
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Piña JO, Raju R, Roth DM, Winchester EW, Chattaraj P, Kidwai F, Faucz FR, Iben J, Mitra A, Campbell K, Fridell G, Esnault C, Cotney JL, Dale RK, D'Souza RN. Multimodal spatiotemporal transcriptomic resolution of embryonic palate osteogenesis. Nat Commun 2023; 14:5687. [PMID: 37709732 PMCID: PMC10502152 DOI: 10.1038/s41467-023-41349-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 08/30/2023] [Indexed: 09/16/2023] Open
Abstract
The terminal differentiation of osteoblasts and subsequent formation of bone marks an important phase in palate development that leads to the separation of the oral and nasal cavities. While the morphogenetic events preceding palatal osteogenesis are well explored, major gaps remain in our understanding of the molecular mechanisms driving the formation of this bony union of the fusing palate. Through bulk, single-nucleus, and spatially resolved RNA-sequencing analyses of the developing secondary palate, we identify a shift in transcriptional programming between embryonic days 14.5 and 15.5 pinpointing the onset of osteogenesis. We define spatially restricted expression patterns of key osteogenic marker genes that are differentially expressed between these developmental timepoints. Finally, we identify genes in the palate highly expressed by palate nasal epithelial cells, also enriched within palatal osteogenic mesenchymal cells. This investigation provides a relevant framework to advance palate-specific diagnostic and therapeutic biomarker discovery.
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Affiliation(s)
- Jeremie Oliver Piña
- Section on Craniofacial Genetic Disorders, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, USA
- School of Dentistry, University of Maryland, Baltimore, MD, USA
| | - Resmi Raju
- Section on Craniofacial Genetic Disorders, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Daniela M Roth
- Section on Craniofacial Genetic Disorders, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA
- School of Dentistry, University of Alberta, Edmonton, AB, Canada
| | | | - Parna Chattaraj
- Section on Craniofacial Genetic Disorders, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Fahad Kidwai
- Section on Craniofacial Genetic Disorders, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Fabio R Faucz
- Molecular Genomics Core, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA
| | - James Iben
- Molecular Genomics Core, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Apratim Mitra
- Bioinformatics and Scientific Programming Core, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Kiersten Campbell
- Bioinformatics and Scientific Programming Core, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Gus Fridell
- Bioinformatics and Scientific Programming Core, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Caroline Esnault
- Bioinformatics and Scientific Programming Core, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Justin L Cotney
- Department of Genetics and Genome Sciences, University of Connecticut, Farmington, CT, USA
| | - Ryan K Dale
- Bioinformatics and Scientific Programming Core, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Rena N D'Souza
- Section on Craniofacial Genetic Disorders, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA.
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5
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Albino J, Dye BA, D'Souza RN. The decades ahead for dental education. J Dent Educ 2022; 86:635-636. [PMID: 35611789 DOI: 10.1002/jdd.12932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Accepted: 03/14/2022] [Indexed: 11/10/2022]
Affiliation(s)
- Judith Albino
- Colorado School of Public Health and School of Dental Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Bruce A Dye
- Department of Community Dentistry and Population Health, School of Dental Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Rena N D'Souza
- National Institute of Dental and Craniofacial Research/NIH, Bethesda, Maryland, USA
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Abstract
Our world is at a turning point with biological and social pathogens wreaking havoc at the same time that science and technology are exploding with new discoveries. It is a pivotal time for the new report Oral Health in America: Advances and Challenges to be released and a pivotal time for our profession to take action and lead. The art, science, and practice of dentistry is very different from 20 y ago when the original Surgeon General's report was released. We are on the precipice of individualized health care where providers will collaborate to deliver diagnostics and therapeutics that are data driven and inclusive of the social determinants of health. To move forward with alacrity requires a strong scientific foundation, effective educational approaches, an understanding of the upstream determinants of health, and partnerships across the health professions and beyond. Oral health has never been more important, and now is the time for our profession to further develop, elevate, and translate the science into practice and policy to improve the nation's health.
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Affiliation(s)
- L K McCauley
- School of Dentistry, University of Michigan, Ann Arbor, MI, USA
| | - M Robinson
- School of Dentistry, University of Alabama at Birmingham, Birmingham, AL, USA
| | - R N D'Souza
- National Institutes of Health, National Institute of Dental and Craniofacial Research, Bethesda, MD, USA
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Albino J, Dye BA, D'Souza RN. Oral health is for all of us. J Public Health Dent 2022; 82:131-132. [PMID: 35352354 DOI: 10.1111/jphd.12517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Accepted: 03/23/2022] [Indexed: 11/26/2022]
Affiliation(s)
- Judith Albino
- Colorado School of Public Health and School of Dental Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Bruce A Dye
- Department of Community Dentistry and Population Health, School of Dental Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Rena N D'Souza
- National Institute of Dental and Craniofacial Research/NIH, Bethesda, Maryland, USA
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Affiliation(s)
- Rena N D'Souza
- From the National Institute of Dental and Craniofacial Research (R.N.D.) and the Office of the Director (F.S.C.), National Institutes of Health, Bethesda, MD; and the U.S. Public Health Service, Office of the Surgeon General, Department of Health and Human Services, Washington, DC (V.H.M.)
| | - Francis S Collins
- From the National Institute of Dental and Craniofacial Research (R.N.D.) and the Office of the Director (F.S.C.), National Institutes of Health, Bethesda, MD; and the U.S. Public Health Service, Office of the Surgeon General, Department of Health and Human Services, Washington, DC (V.H.M.)
| | - Vivek H Murthy
- From the National Institute of Dental and Craniofacial Research (R.N.D.) and the Office of the Director (F.S.C.), National Institutes of Health, Bethesda, MD; and the U.S. Public Health Service, Office of the Surgeon General, Department of Health and Human Services, Washington, DC (V.H.M.)
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Affiliation(s)
- Bruce A Dye
- National Institute of Dental and Craniofacial Research, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892-4320, USA
| | - Judith Albino
- National Institute of Dental and Craniofacial Research, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892-4320, USA; University of Colorado Anschutz Medical Campus Denver, CO, USA
| | - Rena N D'Souza
- National Institute of Dental and Craniofacial Research, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892-4320, USA.
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10
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D'Souza RN, Shum L. Leaving no stone unturned: The National Institute of Dental and Craniofacial Research's scientific response to COVID-19. J Am Dent Assoc 2021; 152:413-414. [PMID: 34044965 PMCID: PMC8064624 DOI: 10.1016/j.adaj.2021.04.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 04/15/2021] [Indexed: 11/18/2022]
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11
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Jia S, Oliver JD, Turner EC, Renouard M, Bei M, Wright JT, D'Souza RN. Pax9's Interaction With the Ectodysplasin Signaling Pathway During the Patterning of Dentition. Front Physiol 2020; 11:581843. [PMID: 33329029 PMCID: PMC7732595 DOI: 10.3389/fphys.2020.581843] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 11/05/2020] [Indexed: 11/30/2022] Open
Abstract
In these studies, we explored for the first time the molecular relationship between the paired-domain-containing transcription factor, Pax9, and the ectodysplasin (Eda) signaling pathway during mouse incisor formation. Mice that were deficient in both Pax9 and Eda were generated, and the status of dentition analyzed in all progeny using gross evaluation and histomorphometric means. When compared to wildtype controls, Pax9+/–Eda–/– mice lack mandibular incisors. Interestingly, Fgf and Shh signaling are down-regulated while Bmp4 and Lef1 appear unaffected. These findings suggest that Pax9-dependent signaling involves the Eda pathway and that this genetic relationship is important for mandibular incisor development. Studies of records of humans affected by mutations in PAX9 lead to the congenital absence of posterior dentition but interestingly involve agenesis of mandibular central incisors. The latter phenotype is exhibited by individuals with EDA or EDAR mutations. Thus, it is likely that PAX9, in addition to playing a role in the formation of more complex dentition, is also involved with EDA signaling in the initiation of odontogenesis within the incisal domain.
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Affiliation(s)
- Shihai Jia
- School of Dentistry, University of Utah Health, Salt Lake City, UT, United States
| | - Jeremie D Oliver
- School of Dentistry, University of Utah Health, Salt Lake City, UT, United States.,Department of Biomedical Engineering, College of Engineering, The University of Utah, Salt Lake City, UT, United States
| | - Emma C Turner
- Dental School, Faculty of Health and Medical Sciences, The University of Western Australia, Perth, WA, Australia
| | - Maranda Renouard
- College of Pharmacy, University of Utah Health, Salt Lake City, UT, United States
| | - Marianna Bei
- Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - J T Wright
- Adams School of Dentistry, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Rena N D'Souza
- School of Dentistry, University of Utah Health, Salt Lake City, UT, United States.,Department of Biomedical Engineering, College of Engineering, The University of Utah, Salt Lake City, UT, United States.,Department of Neurobiology and Anatomy, Pathology, and Surgery, The University of Utah, Salt Lake City, UT, United States
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Ruspita I, Das P, Xia Y, Kelangi S, Miyoshi K, Noma T, Snead ML, D'Souza RN, Bei M. An Msx2- Sp6-Follistatin Pathway Operates During Late Stages of Tooth Development to Control Amelogenesis. Front Physiol 2020; 11:582610. [PMID: 33192593 PMCID: PMC7649293 DOI: 10.3389/fphys.2020.582610] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Accepted: 09/28/2020] [Indexed: 12/15/2022] Open
Abstract
Background Ameloblasts are epithelially derived cells responsible for enamel formation through a process known as amelogenesis. Amongst the several transcription factors that are expressed during amelogenesis, both Msx2 and Sp6 transcription factors play important role. Msx2 and Sp6 mouse mutants, exhibit similar amelogenesis defects, namely enamel hypoplasia, while humans with amelogenesis imperfecta (AI) carry mutations in the human homologues of MSX2 or SP6 genes. These across species similarities in function indicate that these two transcription factors may reside in the same developmental pathway. In this paper, we test whether they work in a coordinated manner to exert their effect during amelogenesis. Methods Two different dental epithelial cell lines, the mouse LS8 and the rat G5 were used for either overexpression or silencing of Msx2 or Sp6 or both. Msx2 mutant mouse embryos or pups were used for in vivo studies. In situ hybridization, semi-quantitative and quantitative real time PCR were employed to study gene expression pattern. MatInspector was used to identify several potential putative Msx2 binding sites upstream of the murine Sp6 promoter region. Chromatin Immunoprecipitation (chIP) was used to confirm the binding of Msx2 to Sp6 promoter at the putative sites. Results Using the above methods we identified that (i) Msx2 and Sp6 exhibit overlapping expression in secretory ameloblasts, (ii) Sp6 expression is reduced in the Msx2 mouse mutant secretoty ameloblasts, and (iii) that Msx2, like Sp6 inhibits follistatin expression. Specifically, our loss-of function studies by silencing Msx2 and/or Sp6 in mouse dental epithelial (LS8) cells showed significant downregulation of Sp6 but upregulation of Fst expression. Transient transfection of Msx2 overexpression plasmid, up-regulated Sp6 and downregulated Fst expression. Additionally, using MatInspector, we identified several potential putative Msx2 binding sites, 3.5 kb upstream of the murine Sp6 promoter region. By chIP, we confirmed the binding of Msx2 to Sp6 promoter at these sites, thus suggesting that Sp6 is a direct target of Msx2. Conclusion Collectively, these results show that Sp6 and Msx2 work in a concerted manner to form part of a network of transcription factors that operate during later stages of tooth development controlling ameloblast life cycle and amelogenesis.
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Affiliation(s)
- Intan Ruspita
- Center for Regenerative and Developmental Biology, The Forsyth Institute, Cambridge, MA, United States.,Department of Prosthodontics, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Pragnya Das
- Center for Regenerative and Developmental Biology, The Forsyth Institute, Cambridge, MA, United States.,Division of Neonatology, Cooper University Hospital, Camden, NJ, United States
| | - Yan Xia
- Center for Regenerative and Developmental Biology, The Forsyth Institute, Cambridge, MA, United States
| | - Sarah Kelangi
- Center for Engineering in Medicine, Department of Surgery, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States.,Shriners Hospital for Children, Boston, MA, United States
| | - Keiko Miyoshi
- Department of Molecular Biology, Institute of Biomedical Sciences, Tokushima University, Tokushima, Japan
| | - Takafumi Noma
- Faculty of Human Life Studies, Hiroshima Jogakuin University, Hiroshima, Japan
| | - Malcolm L Snead
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry of USC, University of Southern California, Los Angeles, CA, United States
| | | | - Marianna Bei
- Center for Engineering in Medicine, Department of Surgery, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States.,Shriners Hospital for Children, Boston, MA, United States
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13
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Oliver JD, Jia S, Halpern LR, Graham EM, Turner EC, Colombo JS, Grainger DW, D'Souza RN. Innovative Molecular and Cellular Therapeutics in Cleft Palate Tissue Engineering. Tissue Eng Part B Rev 2020; 27:215-237. [PMID: 32873216 DOI: 10.1089/ten.teb.2020.0181] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Clefts of the lip and/or palate are the most prevalent orofacial birth defects occurring in about 1:700 live human births worldwide. Early postnatal surgical interventions are extensive and staged to bring about optimal growth and fusion of palatal shelves. Severe cleft defects pose a challenge to correct with surgery alone, resulting in complications and sequelae requiring life-long, multidisciplinary care. Advances made in materials science innovation, including scaffold-based delivery systems for precision tissue engineering, now offer new avenues for stimulating bone formation at the site of surgical correction for palatal clefts. In this study, we review the present scientific literature on key developmental events that can go awry in palate development and the common surgical practices and challenges faced in correcting cleft defects. How key osteoinductive pathways implicated in palatogenesis inform the design and optimization of constructs for cleft palate correction is discussed within the context of translation to humans. Finally, we highlight new osteogenic agents and innovative delivery systems with the potential to be adopted in engineering-based therapeutic approaches for the correction of palatal defects. Impact statement Tissue-engineered scaffolds supplemented with osteogenic growth factors have attractive, largely unexplored possibilities to modulate molecular signaling networks relevant to driving palatogenesis in the context of congenital anomalies (e.g., cleft palate). Constructs that address this need may obviate current use of autologous bone grafts, thereby avoiding donor-site morbidity and other regenerative challenges in patients afflicted with palatal clefts. Combinations of biomaterials and drug delivery of diverse regenerative cues and biologics are currently transforming strategies exploited by engineers, scientists, and clinicians for palatal cleft repair.
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Affiliation(s)
- Jeremie D Oliver
- School of Dentistry, University of Utah Health Sciences, Salt Lake City, Utah, USA.,Department of Biomedical Engineering, University of Utah, Salt Lake City, Utah, USA
| | - Shihai Jia
- School of Dentistry, University of Utah Health Sciences, Salt Lake City, Utah, USA
| | - Leslie R Halpern
- School of Dentistry, University of Utah Health Sciences, Salt Lake City, Utah, USA
| | - Emily M Graham
- School of Medicine, University of Utah Health Sciences, Salt Lake City, Utah, USA
| | - Emma C Turner
- University of Western Australia Dental School, Perth, Western Australia
| | - John S Colombo
- University of Las Vegas at Nevada School of Dental Medicine, Las Vegas, Nevada, USA
| | - David W Grainger
- Department of Biomedical Engineering, University of Utah, Salt Lake City, Utah, USA.,Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah Health Sciences, Salt Lake City, Utah, USA
| | - Rena N D'Souza
- School of Dentistry, University of Utah Health Sciences, Salt Lake City, Utah, USA.,Department of Biomedical Engineering, University of Utah, Salt Lake City, Utah, USA.,School of Medicine, University of Utah Health Sciences, Salt Lake City, Utah, USA
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14
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15
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Jia S, Zhou J, D'Souza RN. Pax9's dual roles in modulating Wnt signaling during murine palatogenesis. Dev Dyn 2020; 249:1274-1284. [PMID: 32390226 DOI: 10.1002/dvdy.189] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 04/23/2020] [Accepted: 05/04/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Despite the strides made in understanding the complex network of key regulatory genes and cellular processes that drive palate morphogenesis, patients suffering from these conditions face treatment options that are limited to complex surgeries and multidisciplinary care throughout life. Hence, a better understanding of how molecular interactions drive palatal growth and fusion is critical for the development of treatment and preventive strategies for cleft palates in humans. Our previous work demonstrated that Pax9-dependent Wnt signaling is critical for the growth and fusion of palatal shelves. We showed that controlled intravenous delivery of small molecule Wnt agonists specifically blocks the action of Dkks (inhibitors of Wnt signaling) and corrects secondary palatal clefts in Pax9-/- mice. While these data underscore the importance of the functional upstream relationship of Pax9 to the Wnt pathway, not much is known about how the genetic nature of Pax9's interactions in vivo and how it modulates the actions of these downstream effectors during palate formation. RESULTS Here, we show that the genetic reduction of Dkk1 during palatogenesis corrected secondary palatal clefts in Pax9-/- mice with restoration of Wnt signaling activities. In contrast, genetically induced overexpression of Dkk1 mice phenocopied the defects in tooth and palate development visible in Pax9-/- strains. Results of ChIP-qPCR assays showed that Pax9 can bind to regions near the transcription start sites of Dkk1 and Dkk2 as well as the intergenic region of Wnt9b and Wnt3 ligands that are downregulated in Pax9-/- palates. CONCLUSIONS Taken together, these data suggest that the molecular mechanisms underlying Pax9's role in modulating Wnt signaling activity likely involve the inhibition of Dkk expression and the control of Wnt ligands during palatogenesis.
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Affiliation(s)
- Shihai Jia
- School of Dentistry, School of Medicine, University of Utah, Salt Lake City, Utah, USA
| | - Jing Zhou
- School of Dentistry, School of Medicine, University of Utah, Salt Lake City, Utah, USA
| | - Rena N D'Souza
- School of Dentistry, School of Medicine, University of Utah, Salt Lake City, Utah, USA.,Department of Neurobiology & Anatomy, School of Medicine, University of Utah, Salt Lake City, Utah, USA.,Department of Pathology, School of Medicine, University of Utah, Salt Lake City, Utah, USA.,Department of Surgery, School of Medicine, University of Utah, Salt Lake City, Utah, USA
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16
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Wu J, Tian Y, Han L, Liu C, Sun T, Li L, Yu Y, Lamichhane B, D'Souza RN, Millar SE, Krumlauf R, Ornitz DM, Feng JQ, Klein O, Zhao H, Zhang F, Linhardt RJ, Wang X. FAM20B-catalyzed glycosaminoglycans control murine tooth number by restricting FGFR2b signaling. BMC Biol 2020; 18:87. [PMID: 32664967 PMCID: PMC7359594 DOI: 10.1186/s12915-020-00813-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 06/17/2020] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND The formation of supernumerary teeth is an excellent model for studying the molecular mechanisms that control stem/progenitor cell homeostasis needed to generate a renewable source of replacement cells and tissues. Although multiple growth factors and transcriptional factors have been associated with supernumerary tooth formation, the regulatory inputs of extracellular matrix in this regenerative process remains poorly understood. RESULTS In this study, we present evidence that disrupting glycosaminoglycans (GAGs) in the dental epithelium of mice by inactivating FAM20B, a xylose kinase essential for GAG assembly, leads to supernumerary tooth formation in a pattern reminiscent of replacement teeth. The dental epithelial GAGs confine murine tooth number by restricting the homeostasis of Sox2(+) dental epithelial stem/progenitor cells in a non-autonomous manner. FAM20B-catalyzed GAGs regulate the cell fate of dental lamina by restricting FGFR2b signaling at the initial stage of tooth development to maintain a subtle balance between the renewal and differentiation of Sox2(+) cells. At the later cap stage, WNT signaling functions as a relay cue to facilitate the supernumerary tooth formation. CONCLUSIONS The novel mechanism we have characterized through which GAGs control the tooth number in mice may also be more broadly relevant for potentiating signaling interactions in other tissues during development and tissue homeostasis.
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Affiliation(s)
- Jingyi Wu
- Southern Medical University Hospital of Stomatology, Guangzhou, 510280, Guangdong, China.,Department of Biomedical Sciences, Texas A&M University College of Dentistry, 3302 Gaston Ave, Dallas, TX, 75246, USA
| | - Ye Tian
- Department of Biomedical Sciences, Texas A&M University College of Dentistry, 3302 Gaston Ave, Dallas, TX, 75246, USA.,West China Hospital of Stomatology, Sichuan University, Chengdu, 610000, Sichuan, China
| | - Lu Han
- Department of Biomedical Sciences, Texas A&M University College of Dentistry, 3302 Gaston Ave, Dallas, TX, 75246, USA.,West China Hospital of Stomatology, Sichuan University, Chengdu, 610000, Sichuan, China
| | - Chao Liu
- Department of Biomedical Sciences, Texas A&M University College of Dentistry, 3302 Gaston Ave, Dallas, TX, 75246, USA.,Department of Oral Pathology, College of Stomatology, Dalian Medical University, Dalian, 116044, Liaoning, China
| | - Tianyu Sun
- Southern Medical University Hospital of Stomatology, Guangzhou, 510280, Guangdong, China.,Department of Biomedical Sciences, Texas A&M University College of Dentistry, 3302 Gaston Ave, Dallas, TX, 75246, USA
| | - Ling Li
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Yanlei Yu
- Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
| | - Bikash Lamichhane
- Department of Biomedical Sciences, Texas A&M University College of Dentistry, 3302 Gaston Ave, Dallas, TX, 75246, USA
| | - Rena N D'Souza
- School of Dentistry, University of Utah, Salt Lake City, UT, 84108, USA
| | - Sarah E Millar
- Department of Dermatology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Robb Krumlauf
- Stowers Institute for Medical Research, Kansas City, MO, 64110, USA.,Department of Anatomy and Cell Biology, Kansas University Medical Center, Kansas City, KS, 66160, USA
| | - David M Ornitz
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Jian Q Feng
- Department of Biomedical Sciences, Texas A&M University College of Dentistry, 3302 Gaston Ave, Dallas, TX, 75246, USA
| | - Ophir Klein
- Department of Orofacial Sciences and Program in Craniofacial Biology, University of California, San Francisco, San Francisco, CA, 94143, USA.,Institute for Human Genetics, University of California, San Francisco, San Francisco, CA, 94143, USA
| | - Hu Zhao
- Department of Biomedical Sciences, Texas A&M University College of Dentistry, 3302 Gaston Ave, Dallas, TX, 75246, USA
| | - Fuming Zhang
- Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
| | - Robert J Linhardt
- Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
| | - Xiaofang Wang
- Department of Biomedical Sciences, Texas A&M University College of Dentistry, 3302 Gaston Ave, Dallas, TX, 75246, USA.
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17
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Abstract
Orofacial clefts and their management impose a substantial burden on patients, on their families, and on the health system. Under the current standard of care, affected patients are subjected to a lifelong journey of corrective surgeries and multidisciplinary management to replace bone and soft tissues, as well as restore esthetics and physiologic functions while restoring self-esteem and psychological health. Hence, a better understanding of the dynamic interplay of molecular signaling pathways at critical phases of palate development is necessary to pioneer novel prenatal interventions. Such pathways include transforming growth factor-β (Tgfβ), sonic hedgehog (Shh), wingless-integrated site (Wnt)/β-catenin, bone morphogenetic protein (Bmp), and fibroblast growth factor (Fgf) and its associated receptors, among others. Here, we summarize commonly used surgical methods used to correct cleft defects postnatally. We also review the advances made in prenatal diagnostics of clefts through imaging and genomics and the various in utero surgical corrections that have been attempted thus far. An overview of how key mediators of signaling that drive palatogenesis are emphasized in the context of the framework and rationale for the development and testing of therapeutics in animal model systems and in humans is provided. The pros and cons of in utero therapies that can potentially restore molecular homeostasis needed for the proper growth and fusion of palatal shelves are presented. The theme advanced throughout this review is the need to develop preclinical molecular therapies that could ultimately be translated into human trials that can correct orofacial clefts at earlier stages of development.
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Affiliation(s)
- J D Oliver
- School of Medicine and School of Dentistry, University of Utah Health, Salt Lake City, UT, USA.,Department of Biomedical Engineering, College of Engineering, University of Utah, Salt Lake City, UT, USA
| | - E C Turner
- University of Western Australia Dental School, Perth, Western Australia
| | - L R Halpern
- School of Medicine and School of Dentistry, University of Utah Health, Salt Lake City, UT, USA
| | - S Jia
- School of Medicine and School of Dentistry, University of Utah Health, Salt Lake City, UT, USA
| | - P Schneider
- Department of Biochemistry, University of Lausanne, Epalinges, Switzerland
| | - R N D'Souza
- School of Medicine and School of Dentistry, University of Utah Health, Salt Lake City, UT, USA.,Department of Biomedical Engineering, College of Engineering, University of Utah, Salt Lake City, UT, USA.,University of Utah, Departments of Neurobiology and Anatomy, Pathology, and Surgery, Salt Lake City, UT, USA
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18
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Garzon I, Chato-Astrain J, Campos F, Fernandez-Valades R, Sanchez-Montesinos I, Campos A, Alaminos M, D'Souza RN, Martin-Piedra MA. Expanded Differentiation Capability of Human Wharton's Jelly Stem Cells Toward Pluripotency: A Systematic Review. Tissue Eng Part B Rev 2020; 26:301-312. [PMID: 32085697 DOI: 10.1089/ten.teb.2019.0257] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Human Wharton's jelly stem cells (HWJSC) can be efficiently isolated from the umbilical cord, and numerous reports have demonstrated that these cells can differentiate into several cell lineages. This fact, coupled with the high proliferation potential of HWJSC, makes them a promising source of stem cells for use in tissue engineering and regenerative medicine. However, their real potentiality has not been established to date. In the present study, we carried out a systematic review to determine the multilineage differentiation potential of HWJSC. After a systematic literature search, we selected 32 publications focused on the differentiation potential of these cells. Analysis of these studies showed that HWJSC display expanded differentiation potential toward some cell types corresponding to all three embryonic cell layers (ectodermal, mesodermal, and endodermal), which is consistent with their constitutive expression of key pluripotency markers such as OCT4, SOX2, and NANOG, and the embryonic marker SSEA4. We conclude that HWJSC can be considered cells in an intermediate state between multipotentiality and pluripotentiality, since their proliferation capability is not unlimited and differentiation to all cell types has not been demonstrated thus far. These findings support the clinical use of HWJSC for the treatment of diseases affecting not only mesoderm-type tissues but also other cell lineages. Impact statement Human Wharton's jelly stem cells (HWJSC) are mesenchymal stem cells that are easy to isolate and handle, and that readily proliferate. Their wide range of differentiation capabilities supports the view that these cells can be considered pluripotent. Accordingly, HWJSC are one of the most promising cell sources for clinical applications in advanced therapies.
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Affiliation(s)
- Ingrid Garzon
- Tissue Engineering Group, Department of Histology, School of Medicine, University of Granada, Granada, Spain.,ibs.GRANADA, Biohealth Institute, Granada, Spain
| | - Jesus Chato-Astrain
- Tissue Engineering Group, Department of Histology, School of Medicine, University of Granada, Granada, Spain.,ibs.GRANADA, Biohealth Institute, Granada, Spain
| | - Fernando Campos
- Tissue Engineering Group, Department of Histology, School of Medicine, University of Granada, Granada, Spain.,ibs.GRANADA, Biohealth Institute, Granada, Spain
| | - Ricardo Fernandez-Valades
- ibs.GRANADA, Biohealth Institute, Granada, Spain.,Division of Pediatric Surgery, University of Granada Hospital Complex, Granada, Spain
| | - Indalecio Sanchez-Montesinos
- ibs.GRANADA, Biohealth Institute, Granada, Spain.,Department of Human Anatomy and Embryology, School of Medicine, University of Granada, Granada, Spain
| | - Antonio Campos
- Tissue Engineering Group, Department of Histology, School of Medicine, University of Granada, Granada, Spain.,ibs.GRANADA, Biohealth Institute, Granada, Spain
| | - Miguel Alaminos
- Tissue Engineering Group, Department of Histology, School of Medicine, University of Granada, Granada, Spain.,ibs.GRANADA, Biohealth Institute, Granada, Spain
| | - Rena N D'Souza
- Department of Dentistry, School of Dentistry, University of Utah, Salt Lake City, Utah, USA
| | - Miguel A Martin-Piedra
- Tissue Engineering Group, Department of Histology, School of Medicine, University of Granada, Granada, Spain.,ibs.GRANADA, Biohealth Institute, Granada, Spain
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19
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Tiwari T, Randall CL, Cohen L, Holtzmann J, Webster-Cyriaque J, Ajiboye S, Schou L, Wandera M, Ikeda K, Fidela de Lima Navarro M, Feres M, Abdellatif H, Al-Madi E, Tubert-Jeannin S, Fox CH, Ioannidou E, D'Souza RN. Gender Inequalities in the Dental Workforce: Global Perspectives. Adv Dent Res 2020; 30:60-68. [PMID: 31746651 DOI: 10.1177/0022034519877398] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The aim of this review is to investigate the growth of diversity and inclusion in global academic dental research with a focus on gender equality. A diverse range of research methodologies were used to conduct this review, including an extensive review of the literature, engagement of key informants in dental academic leadership positions around the world, and review of current data from a variety of national and international organizations. Results provide evidence of gender inequalities that currently persist in dental academics and research. Although the gender gap among graduating dental students in North America and the two most populous countries in Europe (the United Kingdom and France) has been narrowed, women make up 30% to 40% of registered dentists in countries throughout Europe, Oceania, Asia, and Africa. In academic dentistry around the globe, greater gender inequality was found to correlate with higher ranking academic and leadership positions in the United States, United Kingdom, several countries in European Union, Japan, and Saudi Arabia. Further disparities are noted in the dental research sector, where women make up 33% of dental researchers in the European Union, 35% in North America, 55% in Brazil, and 25% in Japan. Family and societal pressures, limited access to research funding, and lack of mentoring and leadership training opportunities are reported as also contributing to gender inequalities. To continue advancing gender equality in dental academia and research, efforts should be geared toward the collection and public dissemination of data on gender-specific distributions. Such evidence-driven information will guide the selection of future strategies and best practices for promoting gender equity in the dental workforce, which provides a major pipeline of researchers and scholars for the dental profession.
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Affiliation(s)
- T Tiwari
- School of Dental Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - C L Randall
- School of Dentistry, University of Washington, Seattle, WA, USA
| | - L Cohen
- National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - J Holtzmann
- School of Dental Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | | | - S Ajiboye
- International Association for Dental Research, Alexandria, VA, USA
| | - L Schou
- National University Health System, Singapore, Singapore
| | - M Wandera
- Uganda Dental Association, Kampala, Uganda
| | - K Ikeda
- School of Dental Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | | | - M Feres
- Guarulhos University, Guarulhos, Brazil
| | - H Abdellatif
- Princess Nourah bint AbdulRahman University, Riyadh, Saudi Arabia
| | - E Al-Madi
- College of Dentistry, King Saud University, Riyadh, Saudi Arabia
| | | | - C H Fox
- International Association for Dental Research, Alexandria, VA, USA
| | - E Ioannidou
- School of Dental Medicine, UConn Health, Farmington, CT, USA
| | - R N D'Souza
- University of Utah Health Sciences, Salt Lake City, UT, USA
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20
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Ioannidou E, Letra A, Shaddox LM, Teles F, Ajiboye S, Ryan M, Fox CH, Tiwari T, D'Souza RN. Empowering Women Researchers in the New Century: IADR's Strategic Direction. Adv Dent Res 2020; 30:69-77. [PMID: 31746653 DOI: 10.1177/0022034519877385] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Gender inequality in science, medicine, and dentistry remains a central concern for the biomedical research workforce today. Although progress in areas of inclusivity and gender diversity was reported, growth has been slow. Women still face multiple challenges in reaching higher ranks and leadership positions while maintaining holistic success in these fields. Within dental research and academia, we might observe trends toward a more balanced pipeline. However, women continue to face barriers in seeking leadership roles and achieving economic equity and scholarship recognition. In an effort to evaluate the status of women in dental research and academia, the authors examined the role of the International Association for Dental Research (IADR), a global research organization, which has improved awareness on gender inequality. The goal of this article is to review five crucial issues of gender inequality in oral health research and academics-workforce pipeline, economic inequality, workplace harassment, gender bias in scholarly productivity, and work-life balance-and to discuss proactive steps that the IADR has taken to promote gender equality. Providing networking and training opportunities through effective mentoring and coaching for women researchers, the IADR has developed a robust pipeline of women leaders while promoting gender equality for women in dental academia through a culture shift. As knowledge gaps remained on the levels of conscious and unconscious bias and sexist culture affecting women advancement in academics, as well as the intersectionality of gender with race, gender identity, ability status, sexual orientation, and cultural backgrounds, the IADR has recognized that further research is warranted.
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Affiliation(s)
- E Ioannidou
- IADR Women in Science Network and AADR Board of Directors; School of Dental Medicine, UCONN Health, Farmington, CT, USA
| | - A Letra
- IADR Women in Science Network; School of Dentistry, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - L M Shaddox
- IADR Women in Science Network; College of Dentistry, University of Kentucky, Lexington, KY, USA
| | - F Teles
- IADR Women in Science Network; School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - S Ajiboye
- International Association for Dental Research and American Association for Dental Research, Alexandria, VA, USA
| | - M Ryan
- American Association for Dental Research; Colgate-Palmolive Company, Piscataway, NJ, USA
| | - C H Fox
- International Association for Dental Research and American Association for Dental Research, Alexandria, VA, USA
| | - T Tiwari
- IADR Women in Science Network; School of Dental Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - R N D'Souza
- International Association for Dental Research; University of Utah Health Sciences, Salt Lake City, UT, USA
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21
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Affiliation(s)
- R N D'Souza
- Schools of Dentistry and Medicine, University of Utah Health, Salt Lake City, UT, USA
| | - E Ioannidou
- School of Dental Medicine, UCONN Health, Farmington, CT, USA
| | - T Tiwari
- Department of Community Dentistry and Population Health, School of Dental Medicine, University of Colorado, Aurora, CO, USA
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22
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Wright JT, Fete M, Schneider H, Zinser M, Koster MI, Clarke AJ, Hadj-Rabia S, Tadini G, Pagnan N, Visinoni AF, Bergendal B, Abbott B, Fete T, Stanford C, Butcher C, D'Souza RN, Sybert VP, Morasso MI. Ectodermal dysplasias: Classification and organization by phenotype, genotype and molecular pathway. Am J Med Genet A 2019; 179:442-447. [PMID: 30703280 PMCID: PMC6421567 DOI: 10.1002/ajmg.a.61045] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 12/19/2018] [Accepted: 12/21/2018] [Indexed: 12/26/2022]
Abstract
An international advisory group met at the National Institutes of Health in Bethesda, Maryland in 2017, to discuss a new classification system for the ectodermal dysplasias (EDs) that would integrate both clinical and molecular information. We propose the following, a working definition of the EDs building on previous classification systems and incorporating current approaches to diagnosis: EDs are genetic conditions affecting the development and/or homeostasis of two or more ectodermal derivatives, including hair, teeth, nails, and certain glands. Genetic variations in genes known to be associated with EDs that affect only one derivative of the ectoderm (attenuated phenotype) will be grouped as non-syndromic traits of the causative gene (e.g., non-syndromic hypodontia or missing teeth associated with pathogenic variants of EDA "ectodysplasin"). Information for categorization and cataloging includes the phenotypic features, Online Mendelian Inheritance in Man number, mode of inheritance, genetic alteration, major developmental pathways involved (e.g., EDA, WNT "wingless-type," TP63 "tumor protein p63") or the components of complex molecular structures (e.g., connexins, keratins, cadherins).
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Affiliation(s)
- John Timothy Wright
- Department of Pediatric Dentistry, Bauer Hall CB#7450, School of Dentistry, University of North Carolina, Chapel Hill, North Carolina
| | - Mary Fete
- National Foundation for Ectodermal Dysplasias, Fairview Heights, Illinois
| | - Holm Schneider
- Department of Pediatrics, University Hospital Erlangen, Erlangen, Germany
| | - Madelaine Zinser
- National Foundation for Ectodermal Dysplasias, Fairview Heights, Illinois
| | - Maranke I Koster
- NFED Scientific Advisory Council, Fairview Heights, Illinois
- Dermatology and Ophthalmology, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Angus J Clarke
- Cancer & Genetics, School of Medicine, Cardiff University, Wales, United Kingdom
| | - Smail Hadj-Rabia
- Department of Dermatology, Reference Center for Genodermatoses and Rare Skin Diseases (MAGEC), INSERM U1163, Descartes - Sorbonne Paris Cité University, Imagine Institute, Necker-Enfants Malades Universitary Hospital, Paris, France
| | - Gianluca Tadini
- Center for Inherited Cutaneous Diseases, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Foundation IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - Nina Pagnan
- Department of Genetics, Federal University of Parana, Curitiba, Brazil
| | | | - Birgitta Bergendal
- National Oral Disability Center for Rare Disorders, The Institute for Postgraduate Dental Education, Jönköping, Sweden
| | - Becky Abbott
- NFED for Treatment & Research, Fairview Heights, Illinois
| | - Timothy Fete
- NFED Scientific Advisory Council, Fairview Heights, Illinois
- Department of Child Health, University of Missouri, Columbia, Missouri
| | - Clark Stanford
- NFED Scientific Advisory Council, Fairview Heights, Illinois
- University of Illinois at Chicago College of Dentistry, Chicago, Illinois
| | - Clayton Butcher
- Departments of Medicine and Child Health, University of Missouri School of Medicine, Columbia, Missouri
| | - Rena N D'Souza
- Academic Affairs and Education, Health Sciences, The University of Utah, Salt Lake City, Utah
| | - Virginia P Sybert
- Division of Medical Genetics, Department of Medicine, University of Washington School of Medicine, Seattle, Washington
| | - Maria I Morasso
- Laboratory of Skin Biology, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD
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23
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Wee Y, Moore AN, Jia S, Zhou J, Colombo JS, D'Souza RN. A Single-Step Self-Assembly Approach for the Fabrication of Aligned and Multilayered Three-Dimensional Tissue Constructs Using Multidomain Peptide Hydrogel. SLAS Technol 2018; 24:55-65. [PMID: 29842850 DOI: 10.1177/2472630318777759] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Hydrogels are homogenous materials that are limited in their ability to form oriented multilayered architecture in three-dimensional (3D) tissue constructs. Current techniques have led to advancements in this area. Such techniques often require extra devices and/or involve complex processes that are inaccessible to many laboratories. Here is described a one-step methodology that permits reliable alignment of cells into multiple layers using a self-assembling multidomain peptide (MDP) hydrogels. We characterized the structural features, viability, and molecular properties of dental pulp cells fabricated with MDP and demonstrated that manipulation of the layering of cells in the scaffolds was achieved by decreasing the weight by volume percentage (w/v%) of MDP contained within the scaffold. This approach allows cells to remodel their environment and enhanced various gene expression profiles, such as cell proliferation, angiogenesis, and extracellular matrix (ECM) remodeling-related genes. We further validated our approach for constructing various architectural configurations of tissues by fabricating cells into stratified multilayered and tubular structures. Our methodology provides a simple, rapid way to generate 3D tissue constructs with multilayered architectures. This method shows great potential to mimic in vivo microenvironments for cells and may be of benefit in modeling more complex tissues in the field of regenerative medicine.
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Affiliation(s)
- Yinshen Wee
- 1 School of Dentistry, University of Utah, Salt Lake City, UT, USA
| | - Amanda N Moore
- 2 Departments of Chemistry and Bioengineering, Rice University, Houston, TX, USA
| | - Shihai Jia
- 1 School of Dentistry, University of Utah, Salt Lake City, UT, USA
| | - Jing Zhou
- 1 School of Dentistry, University of Utah, Salt Lake City, UT, USA
| | - John S Colombo
- 1 School of Dentistry, University of Utah, Salt Lake City, UT, USA
| | - Rena N D'Souza
- 1 School of Dentistry, University of Utah, Salt Lake City, UT, USA
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24
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D'Souza RN, Colombo JS. How Research Training Will Shape the Future of Dental, Oral, and Craniofacial Research. J Dent Educ 2017; 81:eS73-eS82. [PMID: 28864807 DOI: 10.21815/jde.017.037] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 02/28/2017] [Indexed: 11/20/2022]
Abstract
This is a critical time in the history of the dental profession for it to fully embrace the responsibility to safeguard its reputation as a learned profession. In this golden era of scientific and technological advances, opportunities abound to create new diagnostics, preventions, treatments, and cures to improve oral health. Dental schools are the largest national resource entrusted with the responsibility to educate, train, and retain oral health researchers who can leverage such technologies and research opportunities that will benefit the profession at large as well as patients. This article reemphasizes the theme that research training and scholarship must be inextricably woven into the environment and culture in dental schools to ensure the future standing of the profession. An overview of the history of support provided by the National Institutes of Health and National Institute of Dental and Craniofacial Research for the training and career development of dentist-scientists is presented. In addition, new data on the outcomes of such investments are presented along with a comparison with other health professions. This overview underscores the need to expand the capacity of a well-trained cadre of oral health researchers through the reengineering of training programs. Such strategies will best prepare future graduates for team science, clinical trials, and translational research as well as other emerging opportunities. The urgent need for national organizations like the American Dental Association, American Dental Education Association, and American Association for Dental Research to create new alliances and novel initiatives to assist dental schools and universities in fulfilling their research mission is emphasized. To ignore such calls for action is to disavow a valuable legacy inherited by the dental profession. This article was written as part of the project "Advancing Dental Education in the 21st Century."
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Affiliation(s)
- Rena N D'Souza
- Dr. D'Souza is Associate Vice Provost for Research, Professor in School of Dentistry, and Professor in Departments of Neurobiology, Anatomy, and Pathology, School of Medicine, University of Utah; and Dr. Colombo is with the School of Dentistry, University of Utah.
| | - John S Colombo
- Dr. D'Souza is Associate Vice Provost for Research, Professor in School of Dentistry, and Professor in Departments of Neurobiology, Anatomy, and Pathology, School of Medicine, University of Utah; and Dr. Colombo is with the School of Dentistry, University of Utah
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25
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Jia S, Zhou J, Fanelli C, Wee Y, Bonds J, Schneider P, Mues G, D'Souza RN. Small-molecule Wnt agonists correct cleft palates in Pax9 mutant mice in utero. Development 2017; 144:3819-3828. [PMID: 28893947 DOI: 10.1242/dev.157750] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2017] [Accepted: 09/05/2017] [Indexed: 01/01/2023]
Abstract
Clefts of the palate and/or lip are among the most common human craniofacial malformations and involve multiple genetic and environmental factors. Defects can only be corrected surgically and require complex life-long treatments. Our studies utilized the well-characterized Pax9-/- mouse model with a consistent cleft palate phenotype to test small-molecule Wnt agonist therapies. We show that the absence of Pax9 alters the expression of Wnt pathway genes including Dkk1 and Dkk2, proven antagonists of Wnt signaling. The functional interactions between Pax9 and Dkk1 are shown by the genetic rescue of secondary palate clefts in Pax9-/-Dkk1f/+;Wnt1Cre embryos. The controlled intravenous delivery of small-molecule Wnt agonists (Dkk inhibitors) into pregnant Pax9+/- mice restored Wnt signaling and led to the growth and fusion of palatal shelves, as marked by an increase in cell proliferation and osteogenesis in utero, while other organ defects were not corrected. This work underscores the importance of Pax9-dependent Wnt signaling in palatogenesis and suggests that this functional upstream molecular relationship can be exploited for the development of therapies for human cleft palates that arise from single-gene disorders.
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Affiliation(s)
- Shihai Jia
- School of Dentistry, University of Utah, Salt Lake City, UT 84112, USA
| | - Jing Zhou
- School of Dentistry, University of Utah, Salt Lake City, UT 84112, USA
| | | | - Yinshen Wee
- School of Dentistry, University of Utah, Salt Lake City, UT 84112, USA
| | - John Bonds
- Department of Biomedical Sciences, Texas A&M University College of Dentistry, Dallas, TX 75246, USA
| | - Pascal Schneider
- Department of Biochemistry, University of Lausanne, CH-1066 Epalinges, Switzerland
| | - Gabriele Mues
- Department of Biomedical Sciences, Texas A&M University College of Dentistry, Dallas, TX 75246, USA
| | - Rena N D'Souza
- School of Dentistry, University of Utah, Salt Lake City, UT 84112, USA .,Departments of Neurobiology & Anatomy, Pathology, School of Medicine, University of Utah, Salt Lake City, UT 84112, USA
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26
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Abstract
To date, surgical interventions are the only means by which craniofacial anomalies can be corrected so that function, esthetics, and the sense of well-being are restored in affected individuals. Unfortunately, for patients with cleft palate-one of the most common of congenital birth defects-treatment following surgery is prolonged over a lifetime and often involves multidisciplinary regimens. Hence, there is a need to understand the molecular pathways that control palatogenesis and to translate such information for the development of noninvasive therapies that can either prevent or correct cleft palates in humans. Here, we use the well-characterized model of the Pax9-/- mouse, which displays a consistent phenotype of a secondary cleft palate, to test a novel therapeutic. Specifically, we demonstrate that the controlled intravenous delivery of a novel mouse monoclonal antibody replacement therapy, which acts as an agonist for the ectodysplasin (Eda) pathway, can resolve cleft palate defects in Pax9-/- embryos in utero. Such pharmacological interventions did not reverse the arrest in tooth, thymus, and parathyroid gland development, suggesting that the relationship of Pax9 to the Eda/Edar pathway is both unique and essential for palatogenesis. Expression analyses and unbiased gene expression profiling studies offer a molecular explanation for the resolution of palatal defects, showing that Eda and Edar-related genes are expressed in normal palatal tissues and that the Eda/Edar signaling pathway is downstream of Pax9 in palatogenesis. Taken together, our data uncover a unique relationship between Pax9 and the Eda/Edar signaling pathway that can be further exploited for the development of noninvasive, safe, and effective therapies for the treatment of cleft palate conditions and other single-gene disorders affecting the craniofacial complex.
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Affiliation(s)
- S Jia
- 1 School of Dentistry, School of Medicine, University of Utah, Salt Lake City, UT, USA
| | - J Zhou
- 1 School of Dentistry, School of Medicine, University of Utah, Salt Lake City, UT, USA
| | - Y Wee
- 1 School of Dentistry, School of Medicine, University of Utah, Salt Lake City, UT, USA
| | - M L Mikkola
- 2 Developmental Biology Program, Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - P Schneider
- 3 Department of Biochemistry, University of Lausanne, Epalinges, Switzerland
| | - R N D'Souza
- 1 School of Dentistry, School of Medicine, University of Utah, Salt Lake City, UT, USA.,4 Departments of Neurobiology & Anatomy, Pathology, School of Medicine, University of Utah, Salt Lake City, UT, USA
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27
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Abstract
Future advances in dental medicine rely on a robust and stable pipeline of dentist-scientists who are dedicated to research inspired by the patients' condition. The biomedical research community faces external and internal pressures that have been building over years. This is now threatening the current and future status of basic, translational and patient-oriented research by dentist-scientists who study dental, oral and craniofacial diseases, population sciences, and prevention. The dental academic, research and practicing communities can no longer ignore the warning signs of a system that is under considerable stress. Here, the authors report findings of the Physician-Scientist Workforce Working Group, charged by the National Institutes of Health (NIH) Director, to perform quantitative and qualitative analyses on dentist-scientists by addressing the size, composition and activities of the group, relative to other health professions. From 1999 to 2012, trends in the numbers of grant applications and awards to dentist-scientists point to an overall decline. Disturbing are the low numbers of new investigators who apply for Early Career NIH Programs. While more seasoned dentist researchers enjoy greater success, the average age of first-time funded dentists is 52.7 y for females and 54.6 y for males, with a relatively low number of applications submitted and funded. These new data led the panel to stress the need to expand the capacity of the dentist-scientist workforce to leverage technologies and research opportunities that benefit the profession at-large. Suggestions were made to invest in developing clinical research faculty, including those with foreign degrees, through new training mechanisms. The creation of new alliances between national organizations like the American Association for Dental Research, the American Dental Education Association and the American Dental Association will undoubtedly lead to bold and concerted actions that must be pursued with a sense of urgency. A more supportive culture within dental schools and universities for dentist-scientists is needed, as their success is critical to the future career choices of their mentees. Knowledge Transfer Statement: Advances in dental medicine rely on a pipeline of dentist-scientists who are dedicated to research inspired by the patients' condition. Despite the recent advancement in technology and innovation, the dental community can no longer ignore the various pressures that threaten the future of the dentist-scientist profession. Here, the authors report findings of the Physician-Scientist Workforce Working Group of NIH that were published in 2014, and draw attention to the key issues threatening the NIH-funded pool of dentist-scientists.
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Affiliation(s)
- R N D'Souza
- 1 University of Utah, Salt Lake City, UT, USA
| | - J S Colombo
- 1 University of Utah, Salt Lake City, UT, USA
| | - M C Embree
- 2 College of Dental Medicine, Columbia University, New York City, NY, USA
| | - J M Myers
- 3 M.D. Anderson Cancer Center, Houston, Texas, USA
| | - T A DeRouen
- 4 University of Washington, Seattle, WA, USA
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28
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Abstract
The molecular mechanisms that maintain the equilibrium of odontoblast progenitor cells in dental pulp are unknown. Here we tested whether homeostasis in dental pulp is modulated by Twist-1, a nuclear protein that partners with Runx2 during osteoblast differentiation. Our analysis of Twist-1(+/−) mice revealed phenotypic changes that involved an earlier onset of dentin matrix formation, increased alkaline phosphatase activity, and pulp stones within the pulp. RT-PCR analyses revealed Twist-1 expression in several adult organs, including pulp. Decreased levels of Twist-1 led to higher levels of type I collagen and Dspp gene expression in perivascular cells associated with the pulp stones. In mice heterozygous for both Twist-1 and Runx2 inactivation, the phenotype of pulp stones appeared completely rescued. These findings suggest that Twist-1 plays a key role in restraining odontoblast differentiation, thus maintaining homeostasis in dental pulp. Furthermore, Twist-1 functions in dental pulp are dependent on its interaction with Runx2.
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Affiliation(s)
- K M Galler
- Department of Biomedical Sciences, Texas A&M University Health Science Center, Baylor College of Dentistry, 3302 Gaston Avenue, Dallas, TX 75246, USA
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29
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Abstract
In dentistry, the maintenance of a vital dental pulp is of paramount importance because teeth devitalized by root canal treatment may become more brittle and prone to structural failure over time. Advanced carious lesions can irreversibly damage the dental pulp by propagating a sustained inflammatory response throughout the tissue. Although the inflammatory response initially drives tissue repair, sustained inflammation has an enormously destructive effect on the vital pulp, eventually leading to total necrosis of the tissue and necessitating its removal. The implications of tooth devitalization have driven significant interest in the development of bioactive materials that facilitate the regeneration of damaged pulp tissues by harnessing the capacity of the dental pulp for self-repair. In considering the process by which pulpitis drives tissue destruction, it is clear that an important step in supporting the regeneration of pulpal tissues is the attenuation of inflammation. Macrophages, key mediators of the immune response, may play a critical role in the resolution of pulpitis because of their ability to switch to a proresolution phenotype. This process can be driven by the resolvins, a family of molecules derived from fatty acids that show great promise as therapeutic agents. In this review, we outline the importance of preserving the capacity of the dental pulp to self-repair through the rapid attenuation of inflammation. Potential treatment modalities, such as shifting macrophages to a proresolving phenotype with resolvins are described, and a range of materials known to support the regeneration of dental pulp are presented.
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Affiliation(s)
- John S Colombo
- School of Dentistry, University of Utah, Salt Lake City, Utah; Department of Chemistry and Bioengineering, Rice University, Houston, Texas
| | - Amanda N Moore
- Department of Chemistry and Bioengineering, Rice University, Houston, Texas
| | | | - Rena N D'Souza
- School of Dentistry, University of Utah, Salt Lake City, Utah. RD'
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30
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Aberg T, Cavender A, Gaikwad JS, Bronckers ALJJ, Wang X, Waltimo-Sirén J, Thesleff I, D'Souza RN. Phenotypic Changes in Dentition of Runx2 Homozygote-null Mutant Mice. J Histochem Cytochem 2016; 52:131-9. [PMID: 14688224 DOI: 10.1177/002215540405200113] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Genetic and molecular studies in humans and mice indicate that Runx2 (Cbfa1) is a critical transcriptional regulator of bone and tooth formation. Heterozygous mutations in Runx2 cause cleidocranial dysplasia (CCD), an inherited disorder in humans and mice characterized by skeletal defects, supernumerary teeth, and delayed eruption. Mice lacking the Runx2 gene die at birth and lack bone and tooth development. Our extended phenotypic studies of Runx2 mutants showed that developing teeth fail to advance beyond the bud stage and that mandibular molar organs were more severely affected than maxillary molar organs. Runx2 (−/−) tooth organs, when transplanted beneath the kidney capsules of nude mice, failed to progress in development. Tooth epithelial-mesenchymal recombinations using Runx2 (+/+) and (−/−) tissues indicate that the defect in mesenchyme cannot be rescued by normal dental epithelium. Finally, our molecular analyses showed differential effects of the absence of Runx2 on tooth extracellular matrix (ECM) gene expression. These data support the hypothesis that Runx2 is one of the key mesenchymal factors that influences tooth morphogenesis and the subsequent differentiation of ameloblasts and odontoblasts.
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Affiliation(s)
- Thomas Aberg
- Institute of Biotechnology, Viikki Biocenter, University of Helsinki, Finland
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31
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D'Souza RN. Orchestrating a bold future for IADR. Indian J Dent Res 2016; 26:557-8. [PMID: 26888229 DOI: 10.4103/0970-9290.176888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Affiliation(s)
- Rena N D'Souza
- Tenured Professor of Dentistry, Associate Vice Provost for Research, Professor of Neurobiology and Anatomy, Professor of Pathology, Salt Lake City, UT 84112, USA
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32
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Meng T, Huang Y, Wang S, Zhang H, Dechow PC, Wang X, Qin C, Shi B, D'Souza RN, Lu Y. Twist1 Is Essential for Tooth Morphogenesis and Odontoblast Differentiation. J Biol Chem 2015; 290:29593-602. [PMID: 26487719 DOI: 10.1074/jbc.m115.680546] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Indexed: 02/05/2023] Open
Abstract
Twist1 is a basic helix-loop-helix-containing transcription factor that is expressed in the dental mesenchyme during the early stages of tooth development. To better delineate its roles in tooth development, we generated Twist1 conditional knockout embryos (Twist2(Cre) (/+);Twist1(fl/fl)) by breeding Twist1 floxed mice (Twist1(fl/fl)) with Twist2-Cre recombinase knockin mice (Twist2(Cre) (/+)). The Twist2(Cre) (/+);Twist1(fl/fl) embryos formed smaller tooth germs and abnormal cusps during early tooth morphogenesis. Molecular and histological analyses showed that the developing molars of the Twist2(Cre) (/+);Twist1(fl/fl) embryos had reduced cell proliferation and expression of fibroblast growth factors 3, 4, 9, and 10 and FGF receptors 1 and 2 in the dental epithelium and mesenchyme. In addition, 3-week-old renal capsular transplants of embryonic day 18.5 Twist2(Cre) (/+);Twist1(fl/fl) molars showed malformed crowns and cusps with defective crown dentin and enamel. Immunohistochemical analyses revealed that the implanted mutant molars had defects in odontoblast differentiation and delayed ameloblast differentiation. Furthermore, in vitro ChIP assays demonstrated that Twist1 was able to bind to a specific region of the Fgf10 promoter. In conclusion, our findings suggest that Twist1 plays crucial roles in regulating tooth development and that it may exert its functions through the FGF signaling pathway.
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Affiliation(s)
- Tian Meng
- From the Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A&M University Baylor College of Dentistry, Dallas, Texas 75246, the State Key Laboratory of Oral Diseases and Department of Cleft Lip and Palate Surgery, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Yanyu Huang
- From the Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A&M University Baylor College of Dentistry, Dallas, Texas 75246, the Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangzhou 510055, China, and
| | - Suzhen Wang
- From the Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A&M University Baylor College of Dentistry, Dallas, Texas 75246
| | - Hua Zhang
- From the Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A&M University Baylor College of Dentistry, Dallas, Texas 75246
| | - Paul C Dechow
- From the Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A&M University Baylor College of Dentistry, Dallas, Texas 75246
| | - Xiaofang Wang
- From the Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A&M University Baylor College of Dentistry, Dallas, Texas 75246
| | - Chunlin Qin
- From the Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A&M University Baylor College of Dentistry, Dallas, Texas 75246
| | - Bing Shi
- the State Key Laboratory of Oral Diseases and Department of Cleft Lip and Palate Surgery, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Rena N D'Souza
- the University of Utah Health Sciences, Salt Lake City, Utah 84112
| | - Yongbo Lu
- From the Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A&M University Baylor College of Dentistry, Dallas, Texas 75246,
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33
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Abstract
Preservation of a vital dental pulp is a central goal of restorative dentistry. Currently, there is significant interest in the development of tissue engineering scaffolds that can serve as biocompatible and bioactive pulp-capping materials, driving dentin bridge formation without causing cytotoxic effects. Our earlier in vitro studies described the biocompatibility of multidomain peptide (MDP) hydrogel scaffolds with dental pulp-derived cells but were limited in their ability to model contact with intact 3-dimensional pulp tissues. Here, we utilize an established ex vivo mandible organ culture model to model these complex interactions. MDP hydrogel scaffolds were injected either at the interface of the odontoblasts and the dentin or into the pulp core of mandible slices and subsequently cultured for up to 10 d. Histology reveals minimal disruption of tissue architecture adjacent to MDP scaffolds injected into the pulp core or odontoblast space. Additionally, the odontoblast layer is structurally preserved in apposition to the MDP scaffold, despite being separated from the dentin. Alizarin red staining suggests mineralization at the periphery of MDP scaffolds injected into the odontoblast space. Immunohistochemistry reveals deposition of dentin sialophosphoprotein by odontoblasts into the adjacent MDP hydrogel, indicating continued functionality. In contrast, no mineralization or dentin sialophosphoprotein deposition is evident around MDP scaffolds injected into the pulp core. Collagen III expression is seen in apposition to gels at all experimental time points. Matrix metalloproteinase 2 expression is observed associated with centrally injected MDP scaffolds at early time points, indicating proteolytic digestion of scaffolds. Thus, MDP scaffolds delivered centrally and peripherally within whole dental pulp tissue are shown to be biocompatible, preserving local tissue architecture. Additionally, odontoblast function and pulp vitality are sustained when MDP scaffolds are intercalated between dentin and the odontoblast region, a finding that has significant implications when considering these materials as pulp-capping agents.
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Affiliation(s)
- A N Moore
- Department of Chemistry, Rice University, Houston, TX, USA
| | - S C Perez
- Department of Chemistry, Rice University, Houston, TX, USA
| | - J D Hartgerink
- Department of Chemistry, Rice University, Houston, TX, USA Department of Bioengineering, Rice University Houston, TX, USA
| | - R N D'Souza
- School of Dentistry, University of Utah, Salt Lake City, UT, USA
| | - J S Colombo
- School of Dentistry, University of Utah, Salt Lake City, UT, USA
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34
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Hanson S, D'Souza RN, Hematti P. Biomaterial-mesenchymal stem cell constructs for immunomodulation in composite tissue engineering. Tissue Eng Part A 2015; 20:2162-8. [PMID: 25140989 DOI: 10.1089/ten.tea.2013.0359] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Cell-based treatments are being developed as a novel approach for the treatment of many diseases in an effort to repair injured tissues and regenerate lost tissues. Interest in the potential use of multipotent progenitor or stem cells has grown significantly in recent years, specifically the use of mesenchymal stem cells (MSCs), for tissue engineering in combination with extracellular matrix-based scaffolds. An area that warrants further attention is the local or systemic host responses toward the implanted cell-biomaterial constructs. Such immunological responses could play a major role in determining the clinical efficacy of the therapeutic device or biomaterials used. MSCs, due to their unique immunomodulatory properties, hold great promise in tissue engineering as they not only directly participate in tissue repair and regeneration but also modulate the host foreign body response toward the engineered constructs. The purpose of this review was to summarize the current state of knowledge and applications of MSC-biomaterial constructs as a potential immunoregulatory tool in tissue engineering. Better understanding of the interactions between biomaterials and cells could translate to the development of clinically relevant and novel cell-based therapeutics for tissue reconstruction and regenerative medicine.
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Affiliation(s)
- Summer Hanson
- 1 Department of Plastic Surgery, The University of Texas MD Anderson Cancer Center , Houston, Texas
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35
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Kumar VA, Taylor NL, Shi S, Wickremasinghe NC, D'Souza RN, Hartgerink JD. Self-assembling multidomain peptides tailor biological responses through biphasic release. Biomaterials 2015; 52:71-8. [PMID: 25818414 DOI: 10.1016/j.biomaterials.2015.01.079] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 01/25/2015] [Accepted: 01/25/2015] [Indexed: 01/08/2023]
Abstract
Delivery of small molecules and drugs to tissues is a mainstay of several tissue engineering strategies. Next generation treatments focused on localized drug delivery offer a more effective means in dealing with refractory healing when compared to systemic approaches. Here we describe a novel multidomain peptide hydrogel that capitalizes on synthetic peptide chemistry, supramolecular self-assembly and cytokine delivery to tailor biological responses. This material is biomimetic, shows shear stress recovery and offers a nanofibrous matrix that sequesters cytokines. The biphasic pattern of cytokine release results in the spatio-temporal activation of THP-1 monocytes and macrophages. Furthermore, macrophage-material interactions are promoted without generation of a proinflammatory environment. Subcutaneous implantation of injectable scaffolds showed a marked increase in macrophage infiltration and polarization dictated by cytokine loading as early as 3 days, with complete scaffold resorption by day 14. Macrophage interaction and response to the peptide composite facilitated the (i) recruitment of monocytes/macrophages, (ii) sustained residence of immune cells until degradation, and (iii) promotion of a pro-resolution M2 environment. Our results suggest the potential use of this injectable cytokine loaded hydrogel scaffold in a variety of tissue engineering applications.
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Affiliation(s)
- Vivek A Kumar
- Department of Chemistry, Rice University, Houston, TX 77030, USA; Department of Bioengineering, Rice University, Houston, TX 77030, USA
| | - Nichole L Taylor
- Department of Chemistry, Rice University, Houston, TX 77030, USA; Department of Bioengineering, Rice University, Houston, TX 77030, USA
| | - Siyu Shi
- Department of Chemistry, Rice University, Houston, TX 77030, USA; Department of Bioengineering, Rice University, Houston, TX 77030, USA
| | - Navindee C Wickremasinghe
- Department of Chemistry, Rice University, Houston, TX 77030, USA; Department of Bioengineering, Rice University, Houston, TX 77030, USA
| | - Rena N D'Souza
- School of Dentistry, University of Utah, Salt Lake City, UT 84112, USA
| | - Jeffrey D Hartgerink
- Department of Chemistry, Rice University, Houston, TX 77030, USA; Department of Bioengineering, Rice University, Houston, TX 77030, USA.
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36
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D'Souza RN, O'Neill P, Arzate H, Robertson PB. A Tribute to the Life of Dr. Barnet M. Levy. J Dent Res 2014; 93:613-5. [PMID: 27455533 DOI: 10.1177/0022034514537275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Huang Y, Meng T, Wang S, Zhang H, Mues G, Qin C, Feng JQ, D'Souza RN, Lu Y. Twist1- and Twist2-haploinsufficiency results in reduced bone formation. PLoS One 2014; 9:e99331. [PMID: 24971743 PMCID: PMC4074031 DOI: 10.1371/journal.pone.0099331] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Accepted: 05/14/2014] [Indexed: 11/19/2022] Open
Abstract
Background Twist1 and Twist2 are highly homologous bHLH transcription factors that exhibit extensive highly overlapping expression profiles during development. While both proteins have been shown to inhibit osteogenesis, only Twist1 haploinsufficiency is associated with the premature synostosis of cranial sutures in mice and humans. On the other hand, biallelic Twist2 deficiency causes only a focal facial dermal dysplasia syndrome or additional cachexia and perinatal lethality in certain mouse strains. It is unclear how these proteins cooperate to synergistically regulate bone formation. Methods Twist1 floxed mice (Twist1f/f) were bred with Twist2-Cre knock-in mice (Twist2Cre/+) to generate Twist1 and Twist2 haploinsufficient mice (Twist1f/+; Twist2Cre/+). X-radiography, micro-CT scans, alcian blue/alizarin red staining, trap staining, BrdU labeling, immunohistochemistry, in situ hybridizations, real-time PCR and dual luciferase assay were employed to investigate the overall skeletal defects and the bone-associated molecular and cellular changes of Twist1f/+;Twist2Cre/+ mice. Results Twist1 and Twist2 haploinsufficient mice did not present with premature ossification and craniosynostosis; instead they displayed reduced bone formation, impaired proliferation and differentiation of osteoprogenitors. These mice exhibited decreased expressions of Fgf2 and Fgfr1–4 in bone, resulting in a down-regulation of FGF signaling. Furthermore, in vitro studies indicated that both Twist1 and Twist2 stimulated 4.9 kb Fgfr2 promoter activity in the presence of E12, a Twist binding partner. Conclusion These data demonstrated that Twist1- and Twist2-haploinsufficiency caused reduced bone formation due to compromised FGF signaling.
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Affiliation(s)
- Yanyu Huang
- Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A&M University Baylor College of Dentistry, Dallas, Texas, United States of America
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine, Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Tian Meng
- Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A&M University Baylor College of Dentistry, Dallas, Texas, United States of America
| | - Suzhen Wang
- Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A&M University Baylor College of Dentistry, Dallas, Texas, United States of America
| | - Hua Zhang
- Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A&M University Baylor College of Dentistry, Dallas, Texas, United States of America
| | - Gabriele Mues
- Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A&M University Baylor College of Dentistry, Dallas, Texas, United States of America
| | - Chunlin Qin
- Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A&M University Baylor College of Dentistry, Dallas, Texas, United States of America
| | - Jian Q. Feng
- Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A&M University Baylor College of Dentistry, Dallas, Texas, United States of America
| | - Rena N. D'Souza
- Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A&M University Baylor College of Dentistry, Dallas, Texas, United States of America
- The University of Utah School of Dentistry, Salt Lake City, Utah, United States of America
| | - Yongbo Lu
- Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A&M University Baylor College of Dentistry, Dallas, Texas, United States of America
- * E-mail:
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38
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Mues G, Bonds J, Xiang L, Vieira AR, Seymen F, Klein O, D'Souza RN. The WNT10A gene in ectodermal dysplasias and selective tooth agenesis. Am J Med Genet A 2014; 164A:2455-60. [PMID: 24700731 DOI: 10.1002/ajmg.a.36520] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 01/30/2014] [Indexed: 11/10/2022]
Abstract
Mutations in the WNT10A gene were first detected in the rare syndrome odonto-onycho-dermal dysplasia (OODD, OMIM257980) but have now also been found to cause about 35-50% of selective tooth agenesis (STHAG4, OMIM150400), a common disorder that mostly affects the permanent dentition. In our random sample of tooth agenesis patients, 40% had at least one mutation in the WNT10A gene. The WNT10A Phe228Ile variant alone reached an allele frequency of 0.21 in the tooth agenesis cohort, about 10 times higher than the allele frequency reported in large SNP databases for Caucasian populations. Patients with bi-allelic WNT10A mutations have severe tooth agenesis while heterozygous individuals are either unaffected or have a mild phenotype. Mutations in the coding areas of the WNT10B gene, which is co-expressed with WNT10A during odontogenesis, and the WNT6 gene which is located at the same chromosomal locus as WNT10A in humans, do not contribute to the tooth agenesis phenotype.
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Affiliation(s)
- Gabriele Mues
- Department of Biomedical Sciences, Texas A&M University-HSC Baylor College of Dentistry, Dallas, Texas
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39
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Affiliation(s)
- E Ioannidou
- Dental Clinical Research Center, University of Connecticut Health Center, Farmington, USA
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40
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Chang JYF, Wang C, Liu J, Huang Y, Jin C, Yang C, Hai B, Liu F, D'Souza RN, McKeehan WL, Wang F. Fibroblast growth factor signaling is essential for self-renewal of dental epithelial stem cells. J Biol Chem 2013; 288:28952-61. [PMID: 23979135 DOI: 10.1074/jbc.m113.506873] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
A constant supply of epithelial cells from dental epithelial stem cell (DESC) niches in the cervical loop (CL) enables mouse incisors to grow continuously throughout life. Elucidation of the cellular and molecular mechanisms underlying this unlimited growth potential is of broad interest for tooth regenerative therapies. Fibroblast growth factor (FGF) signaling is essential for the development of mouse incisors and for maintenance of the CL during prenatal development. However, how FGF signaling in DESCs controls the self-renewal and differentiation of the cells is not well understood. Herein, we report that FGF signaling is essential for self-renewal and the prevention of cell differentiation of DESCs in the CL as well as in DESC spheres. Inhibiting the FGF signaling pathway decreased proliferation and increased apoptosis of the cells in DESC spheres. Suppressing FGFR or its downstream signal transduction pathways diminished Lgr5-expressing cells in the CL and promoted cell differentiation both in DESC spheres and the CL. Furthermore, disruption of the FGF pathway abrogated Wnt signaling to promote Lgr5 expression in DESCs both in vitro and in vivo. This study sheds new light on understanding the mechanism by which the homeostasis, expansion, and differentiation of DESCs are regulated.
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Affiliation(s)
- Julia Yu Fong Chang
- From the Center for Cancer and Stem Cell Biology, Institute of Biosciences and Technology, Texas A&M University, Houston, Texas 77030-3303
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Chang JYF, Wang C, Jin C, Yang C, Huang Y, Liu J, McKeehan WL, D'Souza RN, Wang F. Self-renewal and multilineage differentiation of mouse dental epithelial stem cells. Stem Cell Res 2013; 11:990-1002. [PMID: 23906788 DOI: 10.1016/j.scr.2013.06.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2013] [Revised: 06/20/2013] [Accepted: 06/21/2013] [Indexed: 02/06/2023] Open
Abstract
Understanding the cellular and molecular mechanisms underlying the self-renewal and differentiation of dental epithelial stem cells (DESCs) that support the unlimited growth potential of mouse incisors is critical for developing novel tooth regenerative therapies and unraveling the pathogenesis of odontogenic tumors. However, analysis of DESC properties and regulation has been limited by the lack of an in vitro assay system and well-documented DESC markers. Here, we describe an in vitro sphere culture system to isolate the DESCs from postnatal mouse incisor cervical loops (CLs) where the DESCs are thought to reside. The dissociated cells from CLs were able to expand and form spheres for multiple generations in the culture system. Lineage tracing indicated that DESC within the spheres were epithelial in origin as evident by lineage tracing. Upon stimulation, the sphere cells differentiated into cytokeratin 14- and amelogenin-expressing and mineral material-producing cells. Compared to the CL tissue, sphere cells expressed high levels of expression of Sca-1, CD49f (also designated as integrin α6), and CD44. Fluorescence-activated cell sorting (FACS) analyses of mouse incisor CL cells further showed that the CD49f(Bright) population was enriched in sphere-forming cells. In addition, the CD49f(Bright) population includes both slow-cycling and Lgr5(+) DESCs. The in vitro sphere culture system and identification of CD49f(Bright) as a DESC marker provide a novel platform for enriching DESCs, interrogating how maintenance, cell fate determination, and differentiation of DESCs are regulated, and developing tooth regenerative therapies.
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Affiliation(s)
- Julia Yu Fong Chang
- Center for Cancer and Stem Cell Biology, Institute of Biosciences and Technology, Texas A&M University, Houston, TX 77030-3303, USA; Department of Biomedical Sciences, Baylor College of Dentistry, Texas A&M University, Houston, TX 77030-3303, USA.
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Sun Y, Jiang Y, Liu Q, Gao T, Feng JQ, Dechow P, D'Souza RN, Qin C, Liu X. Biomimetic engineering of nanofibrous gelatin scaffolds with noncollagenous proteins for enhanced bone regeneration. Tissue Eng Part A 2013; 19:1754-63. [PMID: 23469769 DOI: 10.1089/ten.tea.2012.0567] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Biomimetic approaches are widely used in scaffolding designs to enhance tissue regeneration. In this study, we integrated noncollagenous proteins (NCPs) from bone extracellular matrix (ECM) with three-dimensional nanofibrous gelatin (NF-Gelatin) scaffolds to form an artificial matrix (NF-Gelatin-NCPs) mimicking both the nano-structured architecture and chemical composition of natural bone ECM. Through a chemical coupling process, the NCPs were evenly distributed over all the surfaces (inner and outer) of the NF-gelatin-NCPs. The in vitro study showed that the number of osteoblasts (MC3T3-E1) on the NF-Gelatin-NCPs was significantly higher than that on the NF-Gelatin after being cultured for 14 days. Both the alkaline phosphatase (ALP) activity and the expression of osteogenic genes (OPN, BSP, DMP1, CON, and Runx2) were significantly higher in the NF-Gelatin-NCPs than in the NF-Gelatin at 3 weeks. Von Kossa staining, backscattered scanning electron microscopy, and microcomputed tomography all revealed a higher amount of mineral deposition in the NF-Gelatin-NCPs than in the NF-Gelatin after in vitro culturing for 3 weeks. The in vivo calvarial defect study indicated that the NF-Gelatin-NCPs recruited more host cells to the defect and regenerated a higher amount of bone than the controls after implantation for 6 weeks. Immunohistochemical staining also showed high-level mineralization of the bone matrix in the NF-Gelatin-NCPs. Taken together, both the in vitro and in vivo results confirmed that the incorporation of NCPs onto the surfaces of the NF-Gelatin scaffold significantly enhanced osteogenesis and mineralization. Biomimetic engineering of the surfaces of the NF-Gelatin scaffold with NCPs, therefore, is a promising strategy to enhance bone regeneration.
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Affiliation(s)
- Yao Sun
- Biomedical Sciences Department, The Center for Craniofacial Research and Diagnosis, Texas A&M University Baylor College of Dentistry, Dallas, TX 75246, USA
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Gibson MP, Zhu Q, Wang S, Liu Q, Liu Y, Wang X, Yuan B, Ruest LB, Feng JQ, D'Souza RN, Qin C, Lu Y. The rescue of dentin matrix protein 1 (DMP1)-deficient tooth defects by the transgenic expression of dentin sialophosphoprotein (DSPP) indicates that DSPP is a downstream effector molecule of DMP1 in dentinogenesis. J Biol Chem 2013; 288:7204-14. [PMID: 23349460 DOI: 10.1074/jbc.m112.445775] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Dentin matrix protein 1 (DMP1) and dentin sialophosphoprotein (DSPP) are essential for the formation of dentin. Previous in vitro studies have indicated that DMP1 might regulate the expression of DSPP during dentinogenesis. To examine whether DMP1 controls dentinogenesis through the regulation of DSPP in vivo, we cross-bred transgenic mice expressing normal DSPP driven by a 3.6-kb rat Col1a1 promoter with Dmp1 KO mice to generate mice expressing the DSPP transgene in the Dmp1 KO genetic background (referred to as "Dmp1 KO/DSPP Tg mice"). We used morphological, histological, and biochemical techniques to characterize the dentin and alveolar bone of Dmp1 KO/DSPP Tg mice compared with Dmp1 KO and wild-type mice. Our analyses showed that the expression of endogenous DSPP was remarkably reduced in the Dmp1 KO mice. Furthermore, the transgenic expression of DSPP rescued the tooth and alveolar bone defects of the Dmp1 KO mice. In addition, our in vitro analyses showed that DMP1 and its 57-kDa C-terminal fragment significantly up-regulated the Dspp promoter activities in a mesenchymal cell line. In contrast, the expression of DMP1 was not altered in the Dspp KO mice. These results provide strong evidence that DSPP is a downstream effector molecule that mediates the roles of DMP1 in dentinogenesis.
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Affiliation(s)
- Monica Prasad Gibson
- Department of Biomedical Sciences, Texas A&M Health Science Center, Baylor College of Dentistry, Dallas, Texas 75246, USA
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Lu Y, Li Y, Cavender AC, Wang S, Mansukhani A, D'Souza RN. Molecular studies on the roles of Runx2 and Twist1 in regulating FGF signaling. Dev Dyn 2012; 241:1708-15. [PMID: 22972545 DOI: 10.1002/dvdy.23858] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/16/2012] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND Supernumerary teeth are often observed in patients suffering from cleidocranial dysplasia due to a mutation in Runx2 that results in haploinsufficiency. However, the underlying molecular mechanisms are poorly defined. In this study, we assessed the roles of Runx2 and its functional antagonist Twist1 in regulating fibroblast growth factor (FGF) signaling using in vitro biochemical approaches. RESULTS We showed that Twist1 stimulated Fgfr2 and Fgf10 expression in a mesenchymal cell line and that it formed heterodimers with ubiquitously expressed E12 (together with E47 encoded by E2A gene) and upregulated Fgfr2 and Fgf10 promoter activities in a dental mesenchyme-derived cell line. We further demonstrated that the bHLH domain of Twist1 was essential for its synergistic activation of Fgfr2 promoter with E12 and that the binding of E12 stabilized Twist1 by preventing it from undergoing lysosomal degradation. Although Runx2 had no apparent effects on Fgfr2 and Fgf10 promoter activities, it inhibited the stimulatory activity of Twist1 on Fgfr2 promoter. CONCLUSIONS These findings suggest that Runx2 haploinsufficiency might result in excessive unbound Twist1 that can freely bind to E12 and enhance FGF signaling, thereby promoting the formation of extra teeth.
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Affiliation(s)
- Yongbo Lu
- Department of Biomedical Sciences, Baylor College of Dentistry, Texas A&M Health Science Center, Dallas, TX 75246, USA
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Gibson MP, Zhu Q, Liu Q, D'Souza RN, Feng JQ, Qin C. Loss of dentin sialophosphoprotein leads to periodontal diseases in mice. J Periodontal Res 2012; 48:221-7. [PMID: 22934831 DOI: 10.1111/j.1600-0765.2012.01523.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/12/2012] [Indexed: 01/04/2023]
Abstract
BACKGROUND AND OBJECTIVE Dentin sialophosphoprotein (DSPP) and its cleaved products, dentin phosphoprotein (DPP) and dentin sialoprotein (DSP), play important roles in biomineralization. Recently, we observed that DSPP is highly expressed in the alveolar bone and cementum, indicating that this molecule may play an important role in the formation and maintenance of a healthy periodontium, and its deletion may cause increased susceptibility to periodontal diseases. The objective of this investigation was to study the effects of Dspp ablation on periodontal tissues by analyzing Dspp null mice. MATERIAL AND METHODS Newborn to 6-mo-old Dspp null mice were examined, and the 3- and 6-mo-old Dspp null mice were characterized in detail using X-ray radiography, histology and scanning electron microscopy (backscattered as well as resin-infiltrating). Wild-type mice of the same age groups served as the normal controls. RESULTS The Dspp null mice showed significant loss of alveolar bone and cementum, particularly in the furcation and interproximal regions of the molars. The alveolar bone appeared porous while the quantity of cementum was reduced in the apical region. The canalicular systems and osteocytes in the alveolar bone were abnormal, with reduced numbers of canaliculi and altered osteocyte morphology. The loss of alveolar bone and cementum along with the detachment of the periodontal ligaments (PDL) led to the apical migration of the epithelial attachment and formation of periodontal pockets. CONCLUSION Inactivation of DSPP leads to the loss of alveolar bone and cementum and increased susceptibility to bacterial infections in PDL of Dspp null mice. The fact that the loss of DSPP results in periodontal diseases indicates that this molecule plays a vital role in maintaining the health of the periodontium.
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Affiliation(s)
- M P Gibson
- Department of Biomedical Sciences, Baylor College of Dentistry, Texas A&M Health Science Center, Dallas, TX, USA
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Siyam A, Wang S, Qin C, Mues G, Stevens R, D'Souza RN, Lu Y. Nuclear localization of DMP1 proteins suggests a role in intracellular signaling. Biochem Biophys Res Commun 2012; 424:641-6. [PMID: 22813642 PMCID: PMC3412887 DOI: 10.1016/j.bbrc.2012.07.037] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Accepted: 07/07/2012] [Indexed: 01/10/2023]
Abstract
Dentin matrix protein 1 (DMP1) is highly expressed in odontoblasts and osteoblasts/osteocytes and plays an essential role in tooth and bone mineralization and phosphate homeostasis. It is debatable whether DMP1, in addition to its function in the extracellular matrix, can enter the nucleus and function as a transcription factor. To better understand its function, we examined the nuclear localization of endogenous and exogenous DMP1 in C3H10T1/2 mesenchymal cells, MC3T3-E1 preosteoblast cells and 17IIA11 odontoblast-like cells. RT-PCR analyses showed the expression of endogenous Dmp1 in all three cell lines, while Western-blot analysis detected a major DMP1 protein band corresponding to the 57 kDa C-terminal fragment generated by proteolytic processing of the secreted full-length DMP1. Immunofluorescent staining demonstrated that non-synchronized cells presented two subpopulations with either nuclear or cytoplasmic localization of endogenous DMP1. In addition, cells transfected with a construct expressing HA-tagged full-length DMP1 also showed either nuclear or cytoplasmic localization of the exogenous DMP1 when examined with an antibody against the HA tag. Furthermore, nuclear DMP1 was restricted to the nucleoplasm but was absent in the nucleolus. In conclusion, these findings suggest that, apart from its role as a constituent of dentin and bone matrix, DMP1 might play a regulatory role in the nucleus.
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Affiliation(s)
- Arwa Siyam
- Department of Biomedical Sciences, Baylor College of Dentistry, Texas A&M Health Science Center, 3302 Gaston Ave., Dallas, TX 75246-2013, United States
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Galler KM, D'Souza RN, Federlin M, Cavender AC, Hartgerink JD, Hecker S, Schmalz G. Dentin conditioning codetermines cell fate in regenerative endodontics. J Endod 2012; 37:1536-41. [PMID: 22000458 DOI: 10.1016/j.joen.2011.08.027] [Citation(s) in RCA: 169] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2011] [Revised: 08/26/2011] [Accepted: 08/30/2011] [Indexed: 01/09/2023]
Abstract
INTRODUCTION Recent successes in dental pulp engineering indicate that regenerative treatment strategies in endodontics are feasible. Clinically, revascularization procedures render completion of root formation in immature teeth. The generation of a pulp-like tissue after seeding of dental pulp stem cells into dentin discs or cylinders and transplantation in vivo is possible. In this experimental setup, which mimics the situation in the root canal, the pretreatment of dentin might influence cellular behavior at the cell-dentin interface. Thus, the objective of this study was to investigate whether dentin conditioning can determine cell fate. METHODS Dental pulp stem cells (DPSCs) were seeded into a growth factor-laden peptide hydrogel, transferred into dentin cylinders, and transplanted subcutaneously into immunocompromised mice. Before cell seeding, dentin cylinders were either pretreated with sodium hypochloride (NaOCl) or conditioned with EDTA. The constructs were explanted after 6 weeks and subjected to histological and immunohistochemical analysis. RESULTS In dentin treated with NaOCl, resorption lacunae were found at the cell-dentin interface created by multinucleated cells with clastic activity. After conditioning with EDTA, DPSCs adjacent to the dentin formed an intimate association with the surface, differentiated into odontoblasts-like cells that expressed dentin sialoprotein, and extended cellular processes into the dentinal tubules. A vascularized soft connective tissue similar to dental pulp was observed inside the dentin cylinder. CONCLUSIONS Dentin conditioning considerably influences DPSC fate when seeded in close proximity to dentin. This information might be critical for optimized strategic planning for future regenerative endodontic treatment.
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Affiliation(s)
- Kerstin M Galler
- Department of Restorative Dentistry and Periodontology, University of Regensburg, Regensburg, Germany.
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Abstract
Stem cells derived from the dental pulp of extracted human third molars (DPSCs) have the potential to differentiate into odontoblasts, osteoblasts, adipocytes, and neural cells when provided with the appropriate conditions. To advance the use of DPSCs for dentin regeneration, it is important to replicate the permissive signals that drive terminal events in odontoblast differentiation during tooth development. Such a strategy is likely to restore a dentin matrix that more resembles the tubular nature of primary dentin. Due to the limitations of culture conditions, the use of ex vivo gene therapy to drive the terminal differentiation of mineralizing cells holds considerable promise. In these studies, we asked whether the forced expression of TWIST1 in DPSCs could alter the potential of these cells to differentiate into odontoblast-like cells. Since the partnership between Runx2 and Twist1 proteins is known to control the onset of osteoblast terminal differentiation, we hypothesized that these genes act to control lineage determination of DPSCs. For the first time, our results showed that Twist1 overexpression in DPSCs enhanced the expression of DSPP, a gene that marks odontoblast terminal differentiation. Furthermore, co-transfection assays showed that Twist1 stimulates Dspp promoter activity by antagonizing Runx2 function in 293FT cells. Analysis of our in vitro data, taken together, suggests that lineage specification of DPSCs can be modulated through ex vivo gene modifications.
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Affiliation(s)
- Y Li
- Biomedical Sciences, Baylor College of Dentistry, Texas A&M Health Science Center, Dallas, 75246, USA
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Abstract
For tissue engineering strategies, the choice of an appropriate scaffold is the first and certainly a crucial step. A vast variety of biomaterials is available: natural or synthetic polymers, extracellular matrix, self-assembling systems, hydrogels, or bioceramics. Each material offers a unique chemistry, composition and structure, degradation profile, and possibility for modification. The role of the scaffold has changed from passive carrier toward a bioactive matrix, which can induce a desired cellular behavior. Tailor-made materials for specific applications can be created. Recent approaches to generate dental pulp rely on established materials, such as collagen, polyester, chitosan, or hydroxyapatite. Results after transplantation show soft connective tissue formation and newly generated dentin. For dentin-pulp-complex engineering, aspects including vascularization, cell-matrix interactions, growth-factor incorporation, matrix degradation, mineralization, and contamination control should be considered. Self-assembling peptide hydrogels are an example of a smart material that can be modified to create customized matrices. Rational design of the peptide sequence allows for control of material stiffness, induction of mineral nucleation, or introduction of antibacterial activity. Cellular responses can be evoked by the incorporation of cell adhesion motifs, enzyme-cleavable sites, and suitable growth factors. The combination of inductive scaffold materials with stem cells might optimize the approaches for dentin-pulp complex regeneration.
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Affiliation(s)
- K M Galler
- University of Regensburg, Department of Restorative Dentistry and Periodontology, Germany.
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Galler KM, Hartgerink JD, Cavender AC, Schmalz G, D'Souza RN. A customized self-assembling peptide hydrogel for dental pulp tissue engineering. Tissue Eng Part A 2011; 18:176-84. [PMID: 21827280 DOI: 10.1089/ten.tea.2011.0222] [Citation(s) in RCA: 187] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Root canal therapy is common practice in dentistry. During this procedure, the inflamed or necrotic dental pulp is removed and replaced with a synthetic material. However, recent research provides evidence that engineering of dental pulp and dentin is possible by using biologically driven approaches. As tissue engineering strategies hold the promise to soon supersede conventional root canal treatment, there is a need for customized scaffolds for stem cell delivery or recruitment. We hypothesize that the incorporation of dental pulp-derived stem cells with bioactive factors into such a scaffold can promote cell proliferation, differentiation, and angiogenesis. In this study, we used a cell adhesive, enzyme-cleavable hydrogel made from self-assembling peptide nanofibers to encapsulate dental pulp stem cells. The growth factors (GFs) fibroblast growth factor basic, transforming growth factor β1, and vascular endothelial growth factor were incorporated into the hydrogel via heparin binding. Release profiles were established, and the influence of GFs on cell morphology and proliferation was assessed to confirm their bioactivity after binding and subsequent release. Cell morphology and spreading in three-dimensional cultures were visualized by using cell tracker and histologic stains. Subcutaneous transplantation of the hydrogel within dentin cylinders into immunocompromised mice led to the formation of a vascularized soft connective tissue similar to dental pulp. These data support the use of this novel biomaterial as a highly promising candidate for future treatment concepts in regenerative endodontics.
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Affiliation(s)
- Kerstin M Galler
- Department of Restorative Dentistry and Periodontology, University of Regensburg, Regensburg, Germany
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