Isolation and characterization of a new SHED cell line as a standard source for stem cell research and clinical...

Stem cells from human exfoliated deciduous teeth (SHED) are multi-potent mesenchymal stem/stromal cells (MSCs) and are inspected a favorable, non-invasive source beneficial to stem cell-mediated regeneration of damaged tissues. Our aim was to establish and characterize a non-immortalized SHED cell line as an accessible resource and novel platform for stem cell research and tissue regeneration studies.

A Healthy exfoliated deciduous molar was extracted from a 12-year-old girl and shipped to an animal cell culture laboratory. Outgrowing primary cells from explanted small pulp tissues were monitored daily and characterized after passage 3 both morphologically and functionally. The SHED cell line was characterized by calculation of doubling time, cytogenetic analyses, STR analysis, adherence to cell culture flasks under standard cell culture media, and immunophenotypic analysis of specific MSC markers (CD90+, CD73+, CD34- and CD45-) using flow cytometry method. Differentiation potential to osteoblast, adipocyte, and chondrocyte was evaluated under standard differentiation media Expression of OCT-4 and NANOG genes was also assessed using RT-PCR method.

After the third day, SHED cells were visible. SHED cells were subcultured when they reached 90 % confluence after approximately 17 days. The doubling time of SHED cells was forty seven hours. SHED immunophenotyping showed the high expression level of CD90 (99.2 %) and CD73 (45.9 %), and approximately no expression of CD34 (0.079 %) and CD45 (0.19 %). The human origin, female gender and chromosomal normality of SHED cells was confirmed by cytogenetic analysis. The STR matching analysis showed that SHED cells are well-identified and authentic. No genetic instability and cross-contamination were observed in SHED cells.

This study provides a new SHED cell line with a normal karyotype and all the characteristics of MSCs, which can be used as a favorable model cell line in biomedical research and a promising source for clinical translation.