Growth and Transcription Factors in Tooth Development

Abstract

Odontogenesis is a complex embryonic process originated by the interaction between two main embryonic components, dental epithelium and ectomesenchyme. This ectomesenchymal interaction is mediated by growth and transcription factors controlling the different aspects of tooth development such as tooth initiation, enamel knot formation and/or cell proliferation and differentiation. The aim of this review was to establish which factors are, how they interact and their functions in Odontogenesis. We have described several signaling pathways which are essential for correct tooth development and organized all available information. Our conclusion is that instead of large amount of information about tooth development, further studies are necessary to clear several essential mechanisms which still remain unknown and/or unclear. Thickening of dental epithelium and mesenchymal condensation: Epithelial BMP-4 and FGF-8 are essential in control of target genes transcription at this stage. They interact, BMP-4 as inhibitor and FGF-8 as inducer, and lead to different responses (Figure 2) [7,16,19] controlling epithelial proliferation. Early markers of tooth position and tooth type: Prior to thickening of dental epithelium various factors are expressed in dental epithelium and mesenchyme determining the position and pattern of prospective tooth.

Unraveling the structure, chemical composition, and conserved signaling in leech teeth

“…Specifically, genes shared with the mouse showed 67.6% (4113 + 864/7362) and 66.3% (4113 + 1080/7826) in Hirudo teeth and Helobdella proboscis, respectively ( Figure 2 (B), Dataset 1). From these datasets, we selected potential candidate genes for tooth formation based on specific criteria: (i) expression in tooth-forming tissues in mice and Hirudo teeth ( Figure 4 (B); Nishikawa and Kawamoto 2015 ; de Sousa-Romero and Moreno-Fernández 2016 ; Neupane et al 2023 ; Song et al 2023 ) and (ii) lack of expression in the toothless leech ( Helobdella proboscis). Following these criteria, we identified three genes – protein tyrosine phosphatase receptor type O ( Ptpro ), prickle planar cell polarity protein 2 ( Prickle2 ), and wnt family protein 16 ( Wnt16 ) (TPM > 1.5) ( Figure 3 (A) and Figure 4 (B)).…”

“…We used embryonic mice tooth germs, Hirudo jaws, and Helobdella proboscises to examine conserved signaling pathways for tooth development for the first time, employing de novo transcriptome analysis. This aimed to better understand the development of dental tissue in non-chordate animals and compare it with mice teeth ( Figure 4 ; Nishikawa and Kawamoto 2015 ; de Sousa-Romero and Moreno-Fernández 2016 ; Neupane et al 2023 ; Song et al 2023 ). The transcriptome data from the toothless leech, Helobdella , was analyzed to deduce the signaling molecules present in toothless leeches.…”

“…The high-throughput analysis of leech teeth and proboscis revealed significant numbers of odontogenic genes shared with vertebrate tooth development ( Figure 4 ; Nishikawa and Kawamoto 2015 ; de Sousa-Romero and Moreno-Fernández 2016 ; Neupane et al 2023 ; Song et al 2023 ). A previous study demonstrated deep genetic homology in specific tissue development among bilaterians (Tarazona et al 2016 ), suggesting possible homology between mouse and Hirudo teeth regarding genetic factors.…”

“…Therefore, to shed some light on the evolutionary perspective of odontogenesis, we conducted de novo transcriptome analysis of mouse, toothed leech ( Hirudo nipponia ) and toothless leech ( Helobdella austinensis ). We selected potential candidate genes for tooth formation based on commonly expressed genes in mice and leeches as revealed by transcriptome analyses, along with genetic information obtained from previous studies (Nishikawa and Kawamoto 2015 ; de Sousa-Romero and Moreno-Fernández 2016 ; Neupane et al 2023 ; Song et al 2023 ). Additionally, using electron microscopy, the present study revealed the chemical composition of leech teeth, along with identifying conserved signaling molecules associated with tooth formation.…”

Historic Background and Current Perspectives in Dental Crown Formation

“…Simultaneously, ectomesenchyme condensation surrounding these ectodermal cell bursts express several transcription factors, which differentiate the forming individual condensations from the rest of mesenchyme [88]. DLX1 and 2 gene expression is found in proximal ectomesenchymal regions where molar teeth are located [15].…”