• Molecules and Cells
• /
• 제37권7호
• /
• pp.562-567
• /
• 2014

Human Hertwig's epithelial root sheath/epithelial rests of Malassez (HERS/ERM) cells are epithelial remnants of teeth residing in the periodontium. Although the functional roles of HERS/ERM cells have yet to be elucidated, they are a unique epithelial cell population in adult teeth and are reported to have stem cell characteristics. Therefore, HERS/ERM cells might play a role as an epithelial component for the repair or regeneration of dental hard tissues; however, they are very rare population in periodontium and the primary isolation of them is considered to be difficult. To overcome these problems, we immortalized primary HERS/ERM cells isolated from human periodontium using SV40 large T antigen (SV40 LT) and performed a characterization of the immortalized cell line. Primary HERS/ERM cells could not be maintained for more than 6 passages; however, immortalized HERS/ERM cells were maintained for more than 20 passages. There were no differences in the morphological and immunophenotypic characteristics of HERS/ERM cells and immortalized HERS/ERM cells. The expression of epithelial stem cell and embryonic stem cell markers was maintained in immortalized HERS/ERM cells. Moreover, immortalized HERS/ERM cells could acquire mesenchymal phenotypes through the epithelial-mesenchymal transition via TGF-${\beta}1$. In conclusion, we established an immortalized human HERS/ERM cell line with SV40 LT and expect this cell line to contribute to the understanding of the functional roles of HERS/ERM cells and the tissue engineering of teeth.

• 한국발생생물학회지:발생과생식
• /
• 제13권2호
• /
• pp.89-95
• /
• 2009

p63은 다양한 상피 조직의 줄기세포와 전구세포에 존재한다는 사실이 잘 알려져 있으나, 치아 형성, 특히 사기질과 뿌리 형성시기에서의 p63 위치느 ㄴ아직 연구해야 할 과제로 남아 있다. 본 연구에서는 p63이 치아 발생 동안 치아상피에 편재하여 나타나는 것을 면역조직화학 기법을 이용하여 확인하였다. p63은 피부, 모낭, 구강점막 그리고 턱밑샘 도관을 포함하는 상피의 바닥층과 바닥위층에 위치하였다. 그러나 치아 부위에서는 치아관의 모든 세포, 사기질기관, 헤르트비히 뿌리상피집 그리고 말라세쯔 상피잔사에 p63이 관찰되었다. 이 결과는 치아 발생 중 p63이 줄기세포 유지 외에도 다른 기능을 한다는 사실을 보여준다.

• International Journal of Oral Biology
• /
• 제36권3호
• /
• pp.135-141
• /
• 2011

Hertwig's epithelial root sheath (HERS) consists of bi-layered cells derived from the inner and outer dental epithelia and plays important roles in tooth root formation as well as in the maintenance and regeneration of periodontal tissues. With regards to the fate of HERS, and although previous reports have suggested that this entails the formation of epithelial rests of Malassez, apoptosis or an epithelial-mesenchymal transformation (EMT), it is unclear what changes occur in the epithelial cells in this structure. This study examined whether HERS cells undergo EMT using a keratin-14 (K14) cre:ROSA 26 transgenic reporter mouse. The K14 transgene is expressed by many epithelial tissues, including the oral epithelium and the enamel organ. A distinct K14 expression pattern was found in the continuous HERS bi-layer and the epithelial diaphragm were visualized by detecting the ${\beta}$-galactosidase (lacZ) activity in 1 week postnatal mice. The 2 and 4 week old mice showed a fragmented HERS with cell aggregation along the root surface. However, some of the lacZ-positive dissociated cells along the root surface were not positive for pan-cytokeratin. These results suggest that the K14 transgene is a valuable marker of HERS. In addition, the current data suggest that some of the HERS cells may lose their epithelial properties after fragmentation and subsequently undergo EMT.