Epidermal growth factor (EGF) has many physiological roles. However, its effects on stem and progenitor Leydig cell development remain unclear. Rat stem and progenitor Leydig cells were cultured with different concentrations of EGF alone or in combination with EGF antagonist, erlotinib or cetuximab. EGF (1 and 10 ng/mL) stimulated the proliferation of stem Leydig cells on the surface of seminiferous tubules and isolated CD90⁺ stem Leydig cells and progenitor Leydig cells but it blocked their differentiation. EGF also exerted anti‐apoptotic effects of progenitor Leydig cells. Erlotinib and cetuximab are able to reverse EGF‐mediated action. Gene microarray and qPCR of EGF‐treated progenitor Leydig cells revealed that the down‐regulation of steroidogenesis‐related proteins (Star and Hsd3b1 ) and antioxidative genes. It was found that EGF acted as a proliferative agent via increasing phosphorylation of AKT1. In conclusion, EGF stimulates the proliferation of rat stem and progenitor Leydig cells but blocks their differentiation.

中文翻译：

---

表皮生长因子调节大鼠干细胞和祖细胞的分化。

表皮生长因子（EGF）具有许多生理作用。但是，其对干细胞和祖细胞的分化仍不清楚。用不同浓度的EGF单独或与EGF拮抗剂，厄洛替尼或西妥昔单抗联合培养大鼠干细胞和祖先Leydig细胞。EGF（1和10 ng / mL）刺激生精小管表面的Leydig干细胞增殖，分离出CD90 ⁺干Leydig细胞和祖Leydig细胞，但阻止了它们的分化。EGF还发挥了祖细胞Leydig细胞的抗凋亡作用。厄洛替尼和西妥昔单抗能够逆转EGF介导的作用。EGF处理的祖细胞的基因芯片和qPCR显示，类固醇生成相关蛋白（Star和Hsd3b1）和抗氧化基因。发现EGF通过增加AKT1的磷酸化而充当增殖剂。总之，EGF刺激大鼠干细胞和祖先Leydig细胞的增殖，但阻止了它们的分化。