title: Inductive ability of human developing and differentiated dental mesenchyme.
abstract: The development of cell-based therapeutic strategies to bioengineer tooth tissue is a promising approach for the treatment of lost or damaged tooth tissue. The lack of a readily available cell source for human dental epithelial cells (ECs) severely constrains the progress of tooth bioengineering. Previous studies in model organisms have demonstrated that developing dental mesenchyme can instruct nondental epithelium to differentiate into enamel-forming epithelium. In this study, we characterized the ability of fetal and adult human dental mesenchyme to promote differentiation of human embryonic stem cell (hESC)-derived ECs (ES-ECs) into ameloblast-lineage cells. ES-ECs were co-cultured either with human fetal dental mesenchymal cells (FDMCs) or with adult dental mesenchymal cells (ADMCs) in either a three-dimensional culture system, or in the renal capsules of SCID mice. When co-cultured with FDMCs in vitro, ES-ECs polarized and expressed amelogenin. Tooth organ-like structures assembled with epithelium and encased mesenchyme and developing enamel-like structures could be detected in the complexes resulting from in vitro and ex vivo co-culture of ES-ECs and FDMCs. In contrast, co-cultured ES-ECs and ADMCs formed amorphous spherical structures and occasionally formed hair. Transcription factors were significantly upregulated in FDMCs compared to ADMCs including MSX1, GLI1, LHX6, LHX8,LEF1 and TBX1. In summary, FDMCs but not ADMCs had the capacity to induce differentiation of ES-ECs into ameloblast lineage cells. Further characterization of the functional differences between these two types of dental mesenchyme could enable reprogramming of ADMCs to enhance their odontogenic inductive competence.
authors.affiliation: Department of Orofacial Sciences, University of California, San Francisco, Calif., USA.
authors.forename: Liwei
authors.initials: L
authors.lastname: Zheng
authors.forename: Rungnapa
authors.initials: R
authors.lastname: Warotayanont
authors.forename: Jonathan
authors.initials: J
authors.lastname: Stahl
authors.forename: Ryo
authors.initials: R
authors.lastname: Kunimatsu
authors.forename: Ophir
authors.initials: O
authors.lastname: Klein
authors.forename: Pamela K
authors.initials: PK
authors.lastname: DenBesten
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000328:Adult; D000565:Ameloblasts / Q000166:cytology / Q000378:metabolism; D053523:Amelogenin / Q000378:metabolism; D000818:Animals; D002454:Cell Differentiation; D019070:Cell Lineage; D053595:Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism; D004847:Epithelial Cells / Q000166:cytology; D004848:Epithelium / Q000196:embryology; D005333:Fetus / Q000166:cytology; D006801:Humans; D051821:Lymphoid Enhancer-Binding Factor 1 / Q000378:metabolism; D008297:Male; D008648:Mesoderm / Q000166:cytology / Q000196:embryology*; D051379:Mice; D016513:Mice, SCID; D009805:Odontogenesis / Q000235:genetics; D010641:Phenotype; D016133:Polymerase Chain Reaction; D014070:Tooth / Q000166:cytology / Q000196:embryology*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014162:Transfection; D015854:Up-Regulation / Q000235:genetics
chemical_list: D053523:Amelogenin; D051821:Lymphoid Enhancer-Binding Factor 1; D014157:Transcription Factors