Effect of growth factors on human dental pulp-stem cells

The aim of the present study was to determine whether single growth factor or conditioned media can influence dental pulp-stem cell differentiation, through increasing tissue formation in static culture.

Method:

Heterogeneous Populations of DP-SCs were enzymatically harvested from third molars of human healthy patients. Then, immunophenotypical characterization was identified by flow cytometry using stromal-associated markers (CD90 and CD105), perivascular marker (STRO-1) and hematopoietic lineages marker (CD24). Afterwards, four different groups were tested: DP-SCs cultured in the conventional culture media as a control group and also cultured in odontogenic induction medium (OM) as a reference control. The other two treatment groups included: DP-SCs in odontogenic induction medium plus recombinant human GDF-5 (500ng/ml rhGDF-5) and 1: 2 medium (1 part SHED-CM: 2 part odontogenic induction medium). The proliferation assay was evaluated by colorimetric assay. The expression of angiogenic and odontoblastic marker genes was measured by real time RT-PCR and quantification of matrix mineralization was assessed by Alizarin red staining.

Result:

The DP-SCs showed immunophenotypical profile positive for CD90, CD105, Stro-1 and CD24. The results showed that SHED-CM and GDF-5 inhibited cell attachment and proliferation after 3, 24 and 48 hrs compared to the control group. Differentiation of DP-SCs was found after short time with up-regulation of angiogenic and odontoblastic genes (ALP, DSPP and VEGF) using real time RT-PCR. However, the expression of these genes was higher in the SHED-CM group. Using Alizarin red staining and calcium quantification, the SHED-CM group was significantly up-regulated compared to the other groups after 14 days

Conclusion:

These preliminary findings proved that the paracrine molecules secreted from stem cells may have inhibitory effect on cells proliferation, but a significant effect on the cells differentiation.