T Porntaveetus1,2, T Osathanon2,3, N Nowwarote3, P Pavasant3, C Srichomthong4,5, K Suphapeetiporn4,5, V Shotelersuk4,5. 1. Craniofacial Genetics and Stem Cells Research Group, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand. 2. Department of Physiology, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand. 3. Mineralized Tissue Research Unit and Department of Anatomy, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand. 4. Center of Excellence for Medical Genetics, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand. 5. Excellence Center for Medical Genetics, King Chulalongkorn Memorial Hospital, the Thai Red Cross Society, Bangkok, Thailand.
Abstract
OBJECTIVE: To investigate physical characteristics and behaviours of dental pulp cells of teeth isolated from a dentinogenesis imperfecta (DGI) patient with a novel dentin sialophosphoprotein (DSPP) mutation. SUBJECTS AND METHODS: Whole exome and Sanger sequencing were employed to identify mutations. Physical characteristics of the teeth were examined. Pulp cells' behaviours including cell proliferation, colony-forming unit, osteogenic differentiation, pluripotent markers, and mesenchymal stem cell markers were investigated. RESULTS: The proband had opalescent brown primary teeth with extensive loss of enamel. Mutation analysis revealed a novel heterozygous 4-bp deletion, c.1915_1918delAAGT (p.K639QfsX674), in exon 5 of the DSPP associated with DGI. Analysis of the extracted primary incisor demonstrated a decrease in brightness but an increase in yellow and red chroma. The dentin showed reduced mineral density. The dentinal tubules were present in the predentin, but progressively collapsed in the dentin. The pulp cells exhibited markedly reduced CD105 expression, decreased cell proliferation, and smaller colony-forming units. CONCLUSIONS: We identified a novel mutation in the DSPP gene which disturbed dentin characteristics and pulp cells' behaviours. Our study expands the mutation spectrum and understanding of pathologic dentin phenotypes related to the frameshift deletion in the dentin phosphoprotein (DPP) region of the DSPP gene.
OBJECTIVE: To investigate physical characteristics and behaviours of dental pulp cells of teeth isolated from a dentinogenesis imperfecta (DGI) patient with a novel dentin sialophosphoprotein (DSPP) mutation. SUBJECTS AND METHODS: Whole exome and Sanger sequencing were employed to identify mutations. Physical characteristics of the teeth were examined. Pulp cells' behaviours including cell proliferation, colony-forming unit, osteogenic differentiation, pluripotent markers, and mesenchymal stem cell markers were investigated. RESULTS: The proband had opalescent brown primary teeth with extensive loss of enamel. Mutation analysis revealed a novel heterozygous 4-bp deletion, c.1915_1918delAAGT (p.K639QfsX674), in exon 5 of the DSPP associated with DGI. Analysis of the extracted primary incisor demonstrated a decrease in brightness but an increase in yellow and red chroma. The dentin showed reduced mineral density. The dentinal tubules were present in the predentin, but progressively collapsed in the dentin. The pulp cells exhibited markedly reduced CD105 expression, decreased cell proliferation, and smaller colony-forming units. CONCLUSIONS: We identified a novel mutation in the DSPP gene which disturbed dentin characteristics and pulp cells' behaviours. Our study expands the mutation spectrum and understanding of pathologic dentin phenotypes related to the frameshift deletion in the dentin phosphoprotein (DPP) region of the DSPP gene.
Authors: Qin Du; Li Cao; Yi Liu; Chunyan Pang; Si Wu; Liwei Zheng; Wei Jiang; Xiaoxue Na; Jing Yu; Shasha Wang; Xianjun Zhu; Jiyun Yang Journal: Ann Transl Med Date: 2021-11
Authors: James P Simmer; Hong Zhang; Sophie J H Moon; Lori A-J Donnelly; Yuan-Ling Lee; Figen Seymen; Mine Koruyucu; Hui-Chen Chan; Kevin Y Lee; Suwei Wu; Chia-Lan Hsiang; Anthony T P Tsai; Rebecca L Slayton; Melissa Morrow; Shih-Kai Wang; Edward D Shields; Jan C-C Hu Journal: Genes (Basel) Date: 2022-05-12 Impact factor: 4.141