Ginsenosides promote proliferation of chicken primordial germ cells via PKC-involved activation of NF-κB

The effect of ginsenosides on proliferation of chicken primordial germ cells (PGCs) was evaluated and involvement of nuclear factor (NF)-κB in the signaling pathway was investigated. PGCs were isolated from the genital ridge of 3.5-4 day embryos and cultured in Medium 199 supplemented with 5% FCS and 10 ng/ml LIF. PGCs subcultured on chicken embryonic fibroblast feeder were challenged with ginsenosides alone or in combination with PKC inhibitor H7 or activator phorbol 12-myristate 13-acetate (PMA) for 24 h. Moreover, the translocation of NF-κB and degradation level of IκBα were investigated by Western blot analysis. Results show that PGCs were identified by periodic acid-Schiff, alkaline phosphatase histochemistry as well as c-kit, SSEA-1 and Oct-4 immunocytochemistry. Treatment with ginsenosides at 1-100 μg/ml significantly increased the number and area of PGC colonies in a dose-dependent manner. However, this proliferating effect was obviously attenuated by combined treatment of H7 (10−7-10−5 M). Similarly, PKC staining of PGC colonies was more intensive after ginsenosides treatment compared with the control group. In addition, treatment with ginsenosides at 1-10 μg/ml stimulated the translocation of NF-κB (p65). However, the NF-κB translocation and the degradation of IκBα were significantly blocked by combined treatment with 10−6 M H7. These results indicated that ginsenosides promote proliferation of chicken PGCs through activation of PKC-involved NF-κB signaling pathway.