193 ROBUST PROPAGATION OF SELF-RENEWING PORCINE NEURAL STEM CELLS ISOLATED FROM TRANSGENIC PIGS WITH A GFAP-CreER^T2 SYSTEM CAPABLE OF CONTROLLING THE EXPRESSION OF EGFP GENES

Abstract

Ample evidence has demonstrated the important roles of pigs because their anatomical, immunologic, and physiological characteristics are fairly similar to humans. In particular, their gyrencephalic brain are more comparable to humans than rodents with similar grey and white matter composition and size. In this study, we isolated and propagated the neural stem cells (GFAP-CreER^T2-NSCs) from the transgenic piglet with expression of CreER^T2, a fusion protein of the DNA recombinase Cre and mutated ligand-binding domain of the human oestrogen receptor, under the control of the GFAP promoter. The primary culture from tissue of porcine CreER^T2 brain led to floating spherical masses of cells that revealed similar morphology and size distribution to neurospheres reported by previous studies. Quantitative analysis indicated a yield of 2.50 ± 0.44 primary spheres per 1,000 viable cells from the neocortex, versus 12.92 ± 1.67 primary spheres per 1,000 viable cells from the periventricular region (PVR) including subventricular zone. Secondary spheres (6.67 ± 1.10 spheres from neocortex versus 23.08 ± 1.96 spheres from PVR cells) were formed from primary spheres at 10 days after passage. Tertiary spheres (8.42 ± 0.99 spheres from neocortex versus 23.08 ± 1.91 spheres from PVR cells) could also be obtained after a second passage, indicating that they were proliferating in vitro. The CreER^T2-NSCs showed normal 36+XY karyotype and representative NSC markers, such as NESTIN, SOX2, and VIMENTIN. After differentiation, we were able to obtain populations of astrocytes and neurons expressing GFAP and TUJ1, respectively. In summary, we verified and propagated the isolated GFAP promoter-driven CreER^T2-NSCs, which would be considered a promising source of cells for treatment of central nervous system diseases.