Characteristics of human natal stem cells cultured in allogeneic medium

ABSTRACT

Abstract Recently, human natal dental pulp stem cells (hNDP-SCs) have been characterized in vitro and it has been shown that they satisfy criteria defining human mesenchymal stromal cells (MSCs), as proposed by the International Society for Cellular Therapy. However, these results were reached in the presence of xenogeneic expansion medium, which has the potential to alter the cells' functional capacity. To determine the validity of the previously reported hNDP-SCs characteristics for human cell therapy, we have cultured hNDP-SCs in allogeneic expansion medium. Two hNDP-SC lineages were isolated from vital natal teeth, donated by a healthy newborn female and cultured in 2% platelet rich plasma (PRP). Analysis of the phenotypic expressions, proliferation rates, viability, telomerase length and in vitro adipogenic, osteogenic and chondrogenic differentiation potentials of two hNDP-SCs lineages (Zn001 and Zn002) were performed. Both lineages displayed similar morphology, proliferation rates, adipogenic, chondrogenic and osteogenic differentiation potential. Telomere shortening by 41.0% and 13.49% occurred from 3rd till 14th passage for lineages Zn001 and Zn002 respectively. Viability of both lineages was higher than 90%. Flow cytometry demonstrated that both lineages were positive to the majority of tested markers, including markers, which were negatively, expressed when hNDP-SCs were cultured previously in xenogeneic medium. Using immune-cytochemistry the cells were shown to express beta III-tubulin, nestin, neurofilaments and Nanog. PRP used as allogeneic medium is suitable for cultivation of hNDP-SCs.

RESUMO

Resumo Recentemente, células-tronco da polpa dental humana (hNDP-SCs) foram caracterizadas in vitro e foi demonstrado que elas satisfazem critérios que definem células mesenquimais do estroma humana (MSCs), tal como proposto pela Sociedade Internacional para Terapia Celular. No entanto, esses resultados foram alcançados na presença de meio de expansão xenogênico, que tem o potencial de alterar a capacidade funcional das células. Para determinar a validade das características das hNDP-SCs anteriormente relatadas para a terapia celular humana, cultivamos hNDP-SCs em meio de expansão alogênico. Duas linhagens hNDP-SC foram isoladas de dentes natais vitais, doadas por uma recém-nascida saudável, e cultivadas em plasma rico em plaquetas a 2% (PRP). Análises das expressões fenotípicas, taxas de proliferação, viabilidade, comprimento de telomerase e potenciais de diferenciação adipogênica, osteogênica e condrogênica in vitro das duas linhagens hNDP-SC (Zn001 e Zn002) foram realizadas. Ambas as linhagens apresentaram morfologia, taxas de proliferação, potencial de diferenciação adipogênico, condrogênico e osteogênico semelhantes. O encurtamento dos telômeros em 41,0% e 13,49% ocorreu da 3ª até a 14ª passagem para as linhagens Zn001 e Zn002, respectivamente. A viabilidade de ambas as linhagens foi superior a 90%. A citometria de fluxo demonstrou que ambas as linhagens foram positivas para a maioria dos marcadores testados, incluindo marcadores, que foram negativamente expressados quando hNDP-SCs foram previamente cultivadas em meio xenogênico. Usando análise imunocitoquímica, as células mostraram expressar a beta III-tubulina, nestina, neurofilamentos e Nanog. O PRP usado como meio alogênico mostrou-se adequado para o cultivo de hNDP-SCs.