Fujian Key Laboratory of Developmental and Neuro Biology, College of Life Science, Fujian Normal University, Fuzhou, Fujian, 350108, P.R. China.
J Dent Res. 2014 May;93(5):490-5. doi: 10.1177/0022034514523988. Epub 2014 Feb 19.
Classic tissue recombination studies have demonstrated that, in the early developing mouse tooth germ, the odontogenic potential, known as the tooth-inductive capability, resides initially in the dental epithelium and then shifts to the dental mesenchyme. However, it remains unknown if human embryonic dental tissues also acquire such odontogenic potential. Here we present evidence that human embryonic dental tissues indeed possess similar tooth-inductive capability. We found that human dental epithelium from the cap stage but not the bell stage was able to induce tooth formation when confronted with human embryonic lip mesenchyme. In contrast, human dental mesenchyme from the bell stage but not the cap stage could induce mouse embryonic second-arch epithelium as well as human keratinocyte stem cells, to become enamel-secreting ameloblasts. We showed that neither post-natal human dental pulp stem cells (DPSCs) nor stem cells from human exfoliated deciduous teeth (SHED) possess odontogenic potential or are odontogenic-competent. Our results demonstrate a conservation of odontogenic potential in mouse and human dental tissues during early tooth development, and will have an implication in the future generation of stem-cell-based bioengineered human replacement teeth.
经典的组织重组研究表明，在早期发育的小鼠牙胚中，牙源性潜能，即牙齿诱导能力，最初存在于牙上皮中，然后转移到牙间质中。然而，目前尚不清楚人类胚胎牙组织是否也具有这种牙源性潜能。在这里，我们提供了证据表明人类胚胎牙组织确实具有类似的牙齿诱导能力。我们发现，人类牙囊期的牙上皮，但不是钟状期的牙上皮，在与人胚胎唇间充质接触时能够诱导牙齿形成。相比之下，人类钟状期的牙间质，但不是牙囊期的牙间质，能够诱导小鼠胚胎第二腭上皮和人角质形成细胞干细胞，成为分泌釉质的成釉细胞。我们表明，无论是出生后人类牙髓干细胞（DPSCs）还是人脱落乳牙干细胞（SHED）都不具有牙源性潜能或牙源性潜能。我们的研究结果表明，在早期牙齿发育过程中，小鼠和人类牙组织中的牙源性潜能是保守的，这将对未来基于干细胞的生物工程人类替代牙齿的产生产生影响。
