Differentiation of nonhuman primate embryonic stem cells along neural lineages

The differentiation of embryonic stem cells (ESCs) into neurons and glial cells represents a promising cell-based therapy for neurodegenerative diseases. Because the rhesus macaque is physiologically and phylogenetically similar to humans, it is a clinically relevant animal model for ESC research. In this study, the pluripotency and neural differentiation potential of a rhesus monkey ESC line (ORMES6) was investigated. ORMES6 was derived from an in vitro produced blastocyst, which is the same way human ESCs have been derived. ORMES6 stably expressed the embryonic transcription factors POU5F1 (Oct4), Sox2 and NANOG. Stage-specific embryonic antigen 4 (SSEA 4) and the glycoproteins TRA-1-60 and TRA-1-81 were also expressed. The embryoid bodies (EBs) formed from ORMES6 ESCs spontaneously gave rise to cells of three germ layers. After exposure to basic fibroblast growth factor (bFGF) for 14–16 days, columnar rosette cells formed in the EB outgrowths. Sox2, microtubule-associated protein (MAP2), β-tublinIII and glial fibrillary acidic protein (GFAP) genes and Nestin, FoxD3, Pax6 and β-tublinIII antigens were expressed in the rosette cells. Oct4 and NANOG expression were remarkably down-regulated in these cells. After removal of bFGF from the medium, the rosette cells differentiated along neural lineages. The differentiated cells expressed MAP2, β-tublinIII, Neuro D and GFAP genes. Most differentiated cells expressed early neuron-specific antigen β-tublinIII (73±4.7%) and some expressed intermediate neuron antigen MAP2 (18±7.2%). However, some differentiated cells expressed the glial cell antigens A2B5 (7.17%±1.2%), GFAP (4.93±1.9%), S100 (7±3.5%) and O4 (0.27±0.2%). The rosette cells were transplanted into the striatum of immune-deficient NIHIII mice. The cells persisted for approximately 2 weeks and expressed Ki67, NeuN, MAP2 and GFAP. These results demonstrate that the rhesus monkey ESC line ORMES6 retains the pluripotent characteristics of ESCs and can be efficiently induced to differentiate along neural lineages.