A Cre-lox approach for transient transgene expression in neural precursor cells and long-term tracking of their progeny in vitro and in vivo

Background: Neural precursor cells ( NPCs) can be isolated from various regions of the postnatal central nervous system ( CNS). Manipulation of gene expression in these cells offers a promising strategy to manipulate their fate both in vitro and in vivo. In this study, we developed a technique that allows the transient manipulation of single/multiple gene expression in NPCs in vitro, and the long-term tracking of their progeny both in vitro and in vivo. Results: In order to combine the advantages of transient transfection with the long-term tracking of the transfected cells progeny, we developed a new approach based on the cre-lox technology. We first established a fast and reliable protocol to isolate and culture NPCs as monolayer, from the spinal cord of neonatal transgenic Rosa26-YFP cre-reporter mice. These cells could be reliably transfected with single/multiple plasmids by nucleofection. Nucleofection with mono- or bicistronic plasmids containing the Cre recombinase gene resulted in efficient recombination and the longterm expression of the YFP-reporter gene. The transient cre-expression was non-toxic for the transfected cells and did not alter their intrinsic properties. Finally, we demonstrated that cretransfected cells could be transplanted into the adult brain, where they maintained YFP expression permitting long-term tracking of their migration and differentiation. Conclusion: This approach allows single/multiple genes to be manipulated in NPCs, while at the same time allowing long-term tracking of the transfected cells progeny to be analyzed both in vitro and in vivo.