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Gruenhagen GW, Mubeen T, Patil C, Stockert J, Streelman JT. Single Cell RNA Sequencing Reveals Deep Homology of Dental Cell Types Across Vertebrates. FRONTIERS IN DENTAL MEDICINE 2022; 3. [DOI: 10.3389/fdmed.2022.845449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/01/2023] Open
Abstract
Like most mammals, humans replace their teeth once throughout their lives and have limited regenerative capabilities. In contrast, mice continually renew tissues lost due to gnawing through a well characterized population of stem cells on the labial surface of the incisor. Most non-mammalian vertebrates replace teeth throughout life; the cellular and molecular mechanisms of successional tooth replacement are largely unknown. Here we use single nuclei RNA sequencing (snRNA-seq) of replacement teeth and adjacent oral lamina in Lake Malawi cichlids, species with lifelong whole–tooth replacement, to make two main discoveries. First, despite hundreds of millions of years of evolution, we demonstrate conservation of cell type gene expression across vertebrate teeth (fish, mouse, human). Second, we used an approach that combines marker gene expression and developmental potential of dental cells to uncover the transcriptional signature of stem-like cells in regenerating teeth. Our work underscores the importance of a comparative framework in the study of vertebrate oral and regenerative biology.
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Lee KE, Kang CM, Jeon M, Kim SO, Lee JH, Choi HJ. General gene expression patterns and stemness of the gingiva and dental pulp. J Dent Sci 2022; 17:284-292. [PMID: 35028049 PMCID: PMC8739237 DOI: 10.1016/j.jds.2021.02.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 02/26/2021] [Indexed: 12/01/2022] Open
Abstract
Background/purpose Due to the unique properties of healing processes and cellular differentiation, the gingiva and dental pulp have attracted attention as a potential source of mesenchymal stem cells (MSCs). The purpose of this study was to obtain molecular-level information on these tissues in terms of their function and differentiation processes and investigate stemness. Materials and methods Healthy gingival tissues were collected from patients (n = 9; aged 7–12 years) who underwent simple surgical procedures, and normal dental pulp tissues were obtained from patients (n = 25; aged 11–25 years) undergoing tooth extraction for orthodontic reasons. Complementary DNA microarray, qRT-qPCR, and immunohistochemical staining were performed to assess general and MSC gene expression patterns. Results In the gingival tissue, genes related to keratinization, the formation of epithelial cells and ectoderm, and immune and/or inflammatory responses were highly expressed. Meanwhile, in the dental pulp tissue, genes related to ion transport, neuronal development and axon guidance, bone and enamel mineralization, extracellular matrix organization, and angiogenesis were highly expressed. When focusing on the expression of MSC genes, induced pluripotent stem (iPS) cell genes, such as Sox2, c-Myc, and KLF4, were expressed at higher levels in the gingival tissue, whereas dental stem cell genes, such as NT5E and VCAM1, were expressed in dental pulp tissue. Conclusion We found different general and MSC gene expression patterns between the gingival and dental pulp tissue. These results have implications for future regenerative medicine, considering the application of gingival tissue as a potential source of iPS cells.
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Affiliation(s)
- Ko Eun Lee
- Department of Pediatric Dentistry, Yonsei University College of Dentistry, Seoul, Republic of Korea
| | - Chung-Min Kang
- Department of Pediatric Dentistry, Yonsei University College of Dentistry, Seoul, Republic of Korea
| | - Mijeong Jeon
- Oral Science Research Center, College of Dentistry, Yonsei University, Seoul, Republic of Korea
| | - Seong-Oh Kim
- Department of Pediatric Dentistry, Yonsei University College of Dentistry, Seoul, Republic of Korea
| | - Jae-Ho Lee
- Department of Pediatric Dentistry, Yonsei University College of Dentistry, Seoul, Republic of Korea
| | - Hyung-Jun Choi
- Department of Pediatric Dentistry, Yonsei University College of Dentistry, Seoul, Republic of Korea
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Orlova E, Carlson JC, Lee MK, Feingold E, McNeil DW, Crout RJ, Weyant RJ, Marazita ML, Shaffer JR. Pilot GWAS of caries in African-Americans shows genetic heterogeneity. BMC Oral Health 2019; 19:215. [PMID: 31533690 PMCID: PMC6751797 DOI: 10.1186/s12903-019-0904-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 08/30/2019] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Dental caries is the most common chronic disease in the US and disproportionately affects racial/ethnic minorities. Caries is heritable, and though genetic heterogeneity exists between ancestries for a substantial portion of loci associated with complex disease, a genome-wide association study (GWAS) of caries specifically in African Americans has not been performed previously. METHODS We performed exploratory GWAS of dental caries in 109 African American adults (age > 18) and 96 children (age 3-12) from the Center for Oral Health Research in Appalachia (COHRA1 cohort). Caries phenotypes (DMFS, DMFT, dft, and dfs indices) assessed by dental exams were tested for association with 5 million genotyped or imputed single nucleotide polymorphisms (SNPs), separately in the two age groups. The GWAS was performed using linear regression with adjustment for age, sex, and two principal components of ancestry. A maximum of 1 million adaptive permutations were run to determine empirical significance. RESULTS No loci met the threshold for genome-wide significance, though some of the strongest signals were near genes previously implicated in caries such as antimicrobial peptide DEFB1 (rs2515501; p = 4.54 × 10- 6) and TUFT1 (rs11805632; p = 5.15 × 10- 6). Effect estimates of lead SNPs at suggestive loci were compared between African Americans and Caucasians (adults N = 918; children N = 983). Significant (p < 5 × 10- 8) genetic heterogeneity for caries risk was found between racial groups for 50% of the suggestive loci in children, and 12-18% of the suggestive loci in adults. CONCLUSIONS The genetic heterogeneity results suggest that there may be differences in the contributions of genetic variants to caries across racial groups, and highlight the critical need for the inclusion of minorities in subsequent and larger genetic studies of caries in order to meet the goals of precision medicine and to reduce oral health disparities.
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Affiliation(s)
- E Orlova
- Department of Human Genetics, Pittsburgh, USA
| | - J C Carlson
- Department of Biostatistics, Graduate School of Public Health, Pittsburgh, USA
| | - M K Lee
- Center for Craniofacial and Dental Genetics, Dept. of Oral Biology, School of Dental Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - E Feingold
- Department of Human Genetics, Pittsburgh, USA
- Department of Biostatistics, Graduate School of Public Health, Pittsburgh, USA
- Center for Craniofacial and Dental Genetics, Dept. of Oral Biology, School of Dental Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - D W McNeil
- Departments of Psychology, & Dental Practice and Rural Health, West Virginia University, Morgantown, USA
| | - R J Crout
- Department of Periodontics, School of Dentistry, West Virginia University, Morgantown, WV, USA
| | - R J Weyant
- Department of Dental Public Health and Information Management, Pittsburgh, USA
| | - M L Marazita
- Department of Human Genetics, Pittsburgh, USA
- Center for Craniofacial and Dental Genetics, Dept. of Oral Biology, School of Dental Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Clinical and Translational Sciences Institute, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Psychiatry, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - J R Shaffer
- Department of Human Genetics, Pittsburgh, USA.
- Center for Craniofacial and Dental Genetics, Dept. of Oral Biology, School of Dental Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
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Heng BC, Jiang S, Yi B, Gong T, Lim LW, Zhang C. Small molecules enhance neurogenic differentiation of dental-derived adult stem cells. Arch Oral Biol 2019; 102:26-38. [PMID: 30954806 DOI: 10.1016/j.archoralbio.2019.03.024] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 03/21/2019] [Accepted: 03/28/2019] [Indexed: 01/01/2023]
Abstract
OBJECTIVE Dental-derived stem cells originate from the embryonic neural crest, and exhibit high neurogenic potential. This study aimed to investigate whether a cocktail of eight small molecules (Valproic acid, CHIR99021, Repsox, Forskolin, SP600125, GO6983, Y-27632 and Dorsomorphin) can enhance the in vitro neurogenic differentiation of dental pulp stem cells (DPSCs), stem cells from apical papilla (SCAPs) and gingival mesenchymal stem cells (GMSCs), as a preliminary step towards clinical applications. MATERIALS AND METHODS Neural induction was carried out with a small molecule cocktail based two-step culture protocol, over a total duration of 14 days. At the 8 and 14 day timepoints, the cells were analyzed for expression of neural markers with immunocytochemistry, qRT-PCR and Western Blot. The Fluo 4-AM calcium flux assay was also performed after a further 14 days of neural maturation. RESULTS More pronounced morphological changes characteristic of the neural lineage (i.e. neuritogenesis) were observed in all three cell types treated with small molecules, as compared to the untreated controls. This was corroborated by the immunocytochemistry, qRT-PCR and western blot data, which showed upregulated expression of several early and mature neural markers in all three cell types treated with small molecules, versus the corresponding untreated controls. Finally, the Fluo-4 AM calcium flux assay showed consistently higher calcium transient (F/Fo) peaks for the small molecule-treated versus untreated control groups. CONCLUSIONS Small molecules can enhance the neurogenic differentiation of DPSCs, SCAPs and GMSCs, which offer much potential for therapeutic applications.
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Affiliation(s)
- Boon Chin Heng
- Peking University School of Stomatology, Beijing, China; Endodontology, Faculty of Dentistry, The University of Hong Kong, Pokfulam, Hong Kong, China; HKU-Shenzhen Institute of Research and Innovation, Shenzhen, China; Faculty of Science and Technology, Sunway University, Selangor Darul Ehsan, Malaysia
| | - Shan Jiang
- Endodontology, Faculty of Dentistry, The University of Hong Kong, Pokfulam, Hong Kong, China; HKU-Shenzhen Institute of Research and Innovation, Shenzhen, China
| | - Baicheng Yi
- Endodontology, Faculty of Dentistry, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - Ting Gong
- Endodontology, Faculty of Dentistry, The University of Hong Kong, Pokfulam, Hong Kong, China; HKU-Shenzhen Institute of Research and Innovation, Shenzhen, China
| | - Lee Wei Lim
- Faculty of Science and Technology, Sunway University, Selangor Darul Ehsan, Malaysia; School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - Chengfei Zhang
- Endodontology, Faculty of Dentistry, The University of Hong Kong, Pokfulam, Hong Kong, China; HKU-Shenzhen Institute of Research and Innovation, Shenzhen, China.
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