IADR Abstract Archives
Role of Dental Pulp Stem Cell-Derived Neurotrophic Factors
Objectives: Dental pulp stem cells (DPSC) are increasingly considered an effective source to rescue and repair damaged neural cells. This study aimed to examine the role of specific neurotrophic factors in DPSC-promoted neuronal survival and neurite outgrowth length by applying specific neutralising antibodies. For this purpose, the established neuronal rat PC-12 cell line was used in comparison with primary trigeminal ganglion cells (TGNC).
Methods: DPSC-conditioned medium (CM) was collected from 72h serum-free rat incisor-derived DPSC cultures. Neurotrophic factors (NGF, BDNF, NT-3, and GDNF) were analysed by specific ELISAs. Under the influence of specific neutralising antibodies against NGF, BDNF, GDNF, NT-3 or mixture of these antibodies (R&D systems), the cell survival and neurite outgrowth length of NeuN and MAP-2 positive PC-12 as well as TGNC were measured using Image J analysis. Gene expression levels of axonal growth-associated protein 43 (GAP-43), Synapsin-I, NeuN, MAP-2, βIII-tubulin and thermal receptor vanilloid potential-I (TRPV1) were analysed by RT-PCR.
Results: The number of DPSC-promoted surviving PC-12 cells was markedly reduced by the addition of anti-GDNF antibodies while the neurite outgrowth was significantly attenuated by anti-NGF, anti-GDNF and anti-BDNF antibodies. In TGNC cultures, inhibition of NT-3 resulted in significant reduction of neuronal survival whereas neurite outgrowth was significantly attenuated by blockage of GDNF. Furthermore, neutralisation of GDNF and NGF resulted in marked downregulation in NeuN, MAP-2, βIII-tubulin and GAP-43 gene expression.
Conclusions: GDNF proved to be critical for PC-12 cell survival, whilst NGF, BDNF and GDNF were involved in the stimulatory action on PC-12 neurite outgrowth. TGNC, however, were predominantly dependent on GDNF for their neurite outgrowth, but not so for cell survival. Thus, this study suggested that DPSC promoted survival and regeneration of primary TGNC and PC-12 neuronal cells by different neurotropic mechanisms.
Methods: DPSC-conditioned medium (CM) was collected from 72h serum-free rat incisor-derived DPSC cultures. Neurotrophic factors (NGF, BDNF, NT-3, and GDNF) were analysed by specific ELISAs. Under the influence of specific neutralising antibodies against NGF, BDNF, GDNF, NT-3 or mixture of these antibodies (R&D systems), the cell survival and neurite outgrowth length of NeuN and MAP-2 positive PC-12 as well as TGNC were measured using Image J analysis. Gene expression levels of axonal growth-associated protein 43 (GAP-43), Synapsin-I, NeuN, MAP-2, βIII-tubulin and thermal receptor vanilloid potential-I (TRPV1) were analysed by RT-PCR.
Results: The number of DPSC-promoted surviving PC-12 cells was markedly reduced by the addition of anti-GDNF antibodies while the neurite outgrowth was significantly attenuated by anti-NGF, anti-GDNF and anti-BDNF antibodies. In TGNC cultures, inhibition of NT-3 resulted in significant reduction of neuronal survival whereas neurite outgrowth was significantly attenuated by blockage of GDNF. Furthermore, neutralisation of GDNF and NGF resulted in marked downregulation in NeuN, MAP-2, βIII-tubulin and GAP-43 gene expression.
Conclusions: GDNF proved to be critical for PC-12 cell survival, whilst NGF, BDNF and GDNF were involved in the stimulatory action on PC-12 neurite outgrowth. TGNC, however, were predominantly dependent on GDNF for their neurite outgrowth, but not so for cell survival. Thus, this study suggested that DPSC promoted survival and regeneration of primary TGNC and PC-12 neuronal cells by different neurotropic mechanisms.