Basic fibroblast growth factor is critical to reprogramming buffalo (Bubalus bubalis) primordial germ cells into embryonic germ stem cell-like cells

- Buffalo EGl-like cells reprogrammed from PGCs had typical characteristics of pluripotent stem cells.
- bFGF is necessary for buffalo EG-like cells derivation and pluripotent state of early passages.
- bFGF/PI3K/AKT pathway plays an important role for reprogramming of buffalo PGC into EG-like cells.
- Inhibition of the p53 pathway, the downstream of PI3K/AKT, phenocopied the addition of bFGF.
- bFGF/MAPK signaling promotes proliferation of buffalo EG-like cells.

Primordial germ cells (PGCs) are destined to form gametes in vivo, and they can be reprogrammed into pluripotent embryonic germ (EG) cells in vitro. Buffalo PGC have been reported to be reprogrammed into EG-like cells, but the identities of the major signaling pathways and culture media involved in this derivation remain unclear. Here, the effects of basic fibroblast growth factor (bFGF) and downstream signaling pathways on the reprogramming of buffalo PGCs into EG-like cells were investigated. Results showed bFGF to be critical to buffalo PGCs to dedifferentiate into EG-like cells (20 ng/mL is optimal) with many characteristics of pluripotent stem cells, including alkaline phosphatase (AP) activity, expression of pluripotency marker genes such as OCT4, NANOG, SOX2, SSEA-1, CDH1, and TRA-1-81, and the capacity to differentiate into all three embryonic germ layers. After chemically inhibiting pathways or components downstream of bFGF, data showed that inhibition of the PI3K/AKT pathway led to significantly lower EG cell derivation, while inhibition of P53 activity resulted in an efficiency of EG cell derivation comparable to that in the presence of bFGF. These results suggest that the role of bFGF in PGC-derived EG-like cell generation is mainly due to the activation of the PI3K/AKT/P53 pathway, in particular, the inhibition of P53 function.