A comparison of neurosphere differentiation potential of canine bone marrow-derived mesenchymal stem cells and adipose-derived mesenchymal stem cells.

Abstract

Stem cell transplantation is one of the most promising yet enigmatic treatments for spinal cord injury (SCI), a common problem in dogs. As pre-differentiated mesenchymal stem cells (MSCs) can be expanded and differentiated into neurospheres in vitro, before being transplanted back, they may prove to be more beneficial for treating SCI. Therefore, we compared the endogenous differentiation potential, including the neuronal cell differentiation, of neurospheres from canine bone marrow MSCs (cBMMSCs) with that of the adipose tissue-derived MSCs (cADMSCs). Nestin-positive neurospheres were generated from MSCs derived from the bone marrow and adipose tissue. Neuronal cells were differentiated from the neurospheres derived from both these tissues. Gene expression analysis revealed that Nestin, βIII-tubulin, NCAM, OCT4 and SOX2 were expressed in MSCs and the corresponding neurospheres. Notably, cBMMSC-derived neuronal cells expressed higher levels of βIII-tubulin. The mRNA expressions of NANOG, Nestin, OCT4 and SOX2 were upregulated in neurospheres derived from both. Immunofluorescence analysis detected the expression of neuronal markers, namely, βIII-tubulin, GFAP, S100, NF200 and MAP2, in differentiated neuron-like cells. Our findings highlight that both cBMMSCs and cADMSCs could be differentiated into neurospheres and neuron-like cells, and therefore, these cells are suitable candidates for cell transplantation. Further, cADMSCs form a more suitable cell source, as larger number of cells could be harvested from cADMSC-derived neurospheres. Future studies employing in vivo transplantation models to investigate the effectiveness of MSCs for treating SCI are warranted.