Tian Ruhui, Yang Shi, Zhu Yong, Zou Shasha, Li Peng, Wang Junlong, Zhu Zijue, Huang Yiran, He Zuping, Li Zheng
Cells Tissues Organs. 2016;201(1):1-13. doi: 10.1159/000440949. Epub 2016 Jan 5.
Vascular endothelial growth factor (VEGF) plays fundamental roles in testicular development; however, its function on testicular regeneration remains unknown. The objective of this study was to explore the roles VEGF/VEGFR2 signaling plays in mouse germ cells and in mouse testicular regeneration. VEGF and the VEGFR2 antagonist SU5416 were added to culture medium to evaluate their effects on spermatogonial stem cell line (C18-4 cells) proliferation. Testicular cells obtained from newborn male ICR mice were grafted into the dorsal region of male BALB/c nude mice. VEGF and SU5416 were injected into the graft sites to assess the effects of the VEGF and VEGFR2 signaling pathways on testicular reconstitution. The grafts were analyzed after 8 weeks. We found that VEGF promoted C18-4 proliferation in vitro, indicating its role in germ cell survival. HE staining revealed that seminiferous tubules were reconstituted and male germ cells from spermatogonia to spermatids could be observed in testis-like tissues 8 weeks after grafting. A few advantaged male germ cells, including spermatocytes and spermatids, were found in SU5416-treated grafts. Moreover, VEGF enhanced the expression of genes specific for male germ cells and vascularization in 8-week grafts, whereas SU5416 decreased the expression of these genes. SU5416-treated grafts had a lower expression of MVH and CD31, indicating that blockade of VEGF/VEGFR2 signaling reduces the efficiency of seminiferous tubule reconstitution. Collectively, these data suggest that VEGF/VEGFR2 signaling regulates germ cell proliferation and promotes testicular regeneration via direct action on germ cells and the enhancement of vascularization.
血管内皮生长因子（VEGF）在睾丸发育中起重要作用；然而，其在睾丸再生中的功能尚不清楚。本研究的目的是探讨VEGF/VEGFR2信号通路在小鼠生殖细胞和小鼠睾丸再生中的作用。将VEGF和VEGFR2拮抗剂SU5416添加到培养基中，以评估它们对精原干细胞系（C18-4细胞）增殖的影响。从新生雄性ICR小鼠获得的睾丸细胞移植到雄性BALB/c裸鼠的背部区域。将VEGF和SU5416注射到移植部位，以评估VEGF和VEGFR2信号通路对睾丸重建的影响。8周后对移植物进行分析。我们发现VEGF在体外促进C18-4增殖，表明其在生殖细胞存活中的作用。苏木精-伊红（HE）染色显示，移植8周后，在睾丸样组织中可见生精小管重建，可观察到从精原细胞到精子细胞的雄性生殖细胞。在SU5416处理的移植物中发现了一些优势雄性生殖细胞，包括精母细胞和精子细胞。此外，VEGF增强了8周移植物中雄性生殖细胞特异性基因和血管生成的表达，而SU5416降低了这些基因的表达。SU5416处理的移植物中MVH和CD31的表达较低，表明阻断VEGF/VEGFR2信号通路会降低生精小管重建的效率。总的来说，这些数据表明VEGF/VEGFR2信号通路通过直接作用于生殖细胞和增强血管生成来调节生殖细胞增殖并促进睾丸再生。
