Spermatogonial stem cells (SSCs) have been used for the production of transgenic animals and for the recovery of male fertility. However, the proliferation of SSCs in vitro is still immature, and the mechanisms and pathways involved in the proliferation of SSCs are not clear. Here, the effects of platelet-derived growth factor-BB (PDGF-BB) and epidermal growth factor (EGF) on the proliferation of dairy goat SSCs in vitro were detected. The results showed that 20 ng/ml PDGF-BB or 25 ng/ml EGF was the optimum concentration, and that the BCL2 in the experimental groups was significantly higher than that in the control (P < 0.05), while BAX and BAD were dramatically downregulated (P < 0.05). The pERK1/2 in the experimental groups was about 3-5 times higher than that in the control. After the specific MEK1/2 inhibitor was added, BCL2 was reduced significantly (P < 0.001), while BAX and BAD were upregulated (P < 0.001). The expression of pERK1/2 decreased by 10%-30%. We speculated that these two growth factors may be mediated through the Ras/ERK1/2 signaling pathway to regulate the expression of pERK1/2 protein, and thus enhance the resistance of SSCs to apoptosis. However, further studies are needed to verify this hypothesis.

中文翻译：

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血小板衍生生长因子-BB和表皮生长因子通过Ras/ERK1/2信号通路促进奶山羊精原干细胞增殖

精原干细胞 (SSC) 已被用于生产转基因动物和恢复雄性生育能力。然而，SSCs的体外增殖尚不成熟，参与SSCs增殖的机制和途径尚不清楚。在这里，检测了血小板衍生生长因子-BB (PDGF-BB) 和表皮生长因子 (EGF) 对奶山羊 SSCs 体外增殖的影响。结果表明，20 ng/ml PDGF-BB或25 ng/ml EGF为最佳浓度，实验组BCL2显着高于对照组（P < 0.05），而BAX和BAD则显着升高。下调（P < 0.05）。实验组的pERK1/2比对照组高约3-5倍。添加特定的 MEK1/2 抑制剂后，BCL2 显着降低（P < 0.001），而 BAX 和 BAD 上调（P < 0.001）。pERK1/2 的表达下降了 10%-30%。我们推测这两种生长因子可能通过Ras/ERK1/2信号通路介导调节pERK1/2蛋白的表达，从而增强SSCs对凋亡的抵抗力。然而，需要进一步的研究来验证这一假设。