Cell Labeling with Cy3 through DNA Hybridization for Assessing Neural Stem Cells Survival and Differentiation

Neural stem cells (NSCs) have been attractive donor sources for cell therapy in traumatic brain injuries (TBI). Monitoring the fate of transplanted cells, including the survival and differentiation, will provide vital information to assess the outcome during the therapy time course. However, the current labeling methods are based on the principles of cell endocytosis, demanding relatively high fluorescent probes concentration and long incubation time, which may affect the proliferation and differentiation of transplanted cells. In our study, an efficient and relatively fast labeling strategy for NSCs with Cy3 based on DNA hybridization was proposed for monitoring the fate of transplanted cells. The oligo[dA]₂₀ conjugated with Cy3 was anchored on NSCs which had modified with oligo[dT]₂₀ via the oligo[dT]₂₀-oligo[dA]₂₀ hybridization. This labeling system did not affect the viability of labeled NSCs. After implantation of labeled NSCs into the brain, immunohistology demonstrated implanted cells were able to survive and differentiate into mature neural cells as long as one month. In conclusion, the DNA hybridization system can be used as an efficient cell labeling method in cell therapy.