Reprogramming oral epithelial keratinocytes into a pluripotent phenotype for tissue regeneration

TERC haploid cell reprogramming: a novel therapeutic strategy for aplastic anemia

The telomerase RNA component (TERC) gene plays an important role in telomerase-dependent extension and maintenance of the telomeres. In the event of TERC haploinsufficiency, telomere length is often affected; this, in turn, can result in the development of progeria-related diseases such as aplastic anemia (AA) and congenital keratosis. Cell reprogramming can reverse the differentiation process and can, therefore, transform cells into pluripotent stem cells with stronger differentiation and self-renewal abilities; further, cell reprograming can also extend the telomere length of these cells, which may be crucial in the diagnosis and treatment of telomere depletion diseases such as AA. In this study, we summarized the effects of TERC haploid cell reprogramming on telomere length and the correlation between this alteration and the pathogenesis of AA; by investigating the role of cell reprogramming in AA, we aimed to identify novel diagnostic indicators and therapeutic strategies for patients with AA.

Partial epithelial-mesenchymal transition during enamel development

Objectives

We set out to investigate whether a hybrid stem‐like p‐EMT phenotype develops during murine molar enamel development in vivo.

Setting and Sample Population

Histology specimens incorporating molar tooth buds harvested from mice at post‐natal day 4 (P4) were included in our studies.

Materials and Methods

We employed double immunofluorescence staining to analyze the simultaneous expression of the epithelial marker E‐cadherin and the mesenchymal marker N‐cadherin in histology specimens with tooth buds harvested from P4 mice. Moreover, we evaluated the expression of the core master stem cell markers Oct4 and Sox2, as well as the mature ameloblast marker amelogenin.

Results

Here we document the co‐expression of E‐cadherin and N‐cadherin in a sub‐population of pre‐ameloblasts in the inner enamel epithelium suggestive of the presence of a hybrid epithelial/mesenchymal phenotype resulting from p‐EMT. Moreover, the core stem cell factors Oct4 and Sox2 colocalized with E‐cadherin expressing pre‐ameloblasts, whereas the mesenchymal marker N‐cadherin was expressed specifically by amelogenin–positive mature secretory ameloblasts.

Conclusions

The differentiation of E‐cadherin–positive pre‐ameloblasts towards N‐cadherin–positive mature secretory ameloblasts transition through a previously unidentified epithelial/mesenchymal stage derived through p‐EMT, co‐expressing the master transcription factors Oct4 and Sox2.