Comparison of stemness and gene expression between gingiva and dental follicles in children

Abstract

Despite similar ectomesenchymal origins, gingiva and dental follicles (DFs) appear to exhibit distinct functional activities during development. The objective of this study was to identify the existence of mesenchymal stem cells (MSCs) in the human DFs and compare multipotent stemness derived from gingiva and DFs according to their biological characteristics. The differential expression of specific genes including stem cell surface markers can define the regeneration ability of the gingiva and differentiation capacity of DFs. Gingiva and DFs were obtained from nine healthy subjects. Comparative gene expression profiles were collected using cDNA microarray analysis and the expression of development, chemotaxis, MSCs and induced pluripotent stem cells (iPSCs) related genes was assessed by quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR). Histological analysis was performed using hematoxylin-eosin and immunohistochemical staining. Gingiva had greater expression of genes related to “keratinization” (including KRT1, DSP, and CSTA), “epidermis and ectodermal development” (including KRT6A, KRT6B, and SCEL), and “chemotaxis” (including CXCL10 and CXCL17) than the DFs; overexpression of these genes indicates fast turnover and enhanced fibroblast proliferation, which are important for outstanding tissue repair in the gingiva. On the other hand, DFs had higher expression levels of genes related to “tooth and embryo development” (including AMBN, WNT, LEF1, PAX3, and LUNX2) and “protein modification and signal transduction” (including ADAM12, CXCL12, and MMP-13). Interestingly, iPSC transcription factors were more highly expressed in the gingiva; SOX2, KLF4, and MYC were 58.5, 12.43, and 12.23 times higher, respectively, in gingival than DFs. Most dental-derived stem cell markers were strongly up-regulated in DFs; VCAM1 (CD106), CD34, and ALCAM (CD166) were 33.54, 5.58, and 4.27 times higher, respectively, in DFs than gingiva. Gingival tissue demonstrated stronger pluripotent capacity than DFs. Because of its accessibility and minimal post-surgical discomfort, the gingiva is a better novel source of stem cells for cell therapy in regenerative dentistry.