Dental pulp cells (DPCs) are composed of a heterogeneous cell population including mesenchymal stem cells. Many studies have proposed the use of DPCs for the treatment of various neurological disorders because of their self-renewal capacity, high proliferation potential, and the ability to undergo multilineage differentiation including functional neurons. However, our understanding of the basic biology of canine DPCs (cDPCs) is rather scarce and their therapeutic potential for neurological disorders has not been studied. Therefore, we characterized cDPCs focusing on their therapeutic potential for treating neurological disorders. We also assessed the efficiency of cell labeling with superparamagnetic iron oxide particles (SPIO) for cell tracking with magnetic resonance imaging (MRI).
Canine DPCs maintained higher proliferation potential than bone marrow stromal cells and skin-derived fibroblasts. Immunocytochemical analysis revealed that some cDPCs co-expressed β-Ⅲ tubulin and glial fibrillary acidic protein. Canine DPCs expressed mRNA for neurotrophic factors, neural growth factor, brain-derived neurotrophic factor and neurotrophin 3, higher than other cell types. Canine DPCs labeled with SPIO had low cytotoxicity and produced a significant change in signal intensity with a low magnetic field (0.4T) MRI unit.
Our data suggest that cDPCs may have the ability to replace lost cells by differentiating into neural cells and/or improve the microenvironment of the injured nervous tissue for neurite outgrowth and neuroprotection. In transplantation studies, SPIO labeling can be used for non-invasive tracking of cDPCs. Dogs spontaneously develop various neurological disorders that closely mirror their human counterparts. These disorders in dogs may offer a unique opportunity to study therapeutic effects of DPCs.