Department of Animal Science, University of Nebraska-Lincoln, 3934 Fair Street, Lincoln, NE 68583-0908, USA.
Reproduction. 2010 Aug;140(2):319-29. doi: 10.1530/REP-09-0456. Epub 2010 May 10.
Vascular endothelial growth factor A (VEGFA) plays a role in both angiogenesis and seminiferous cord formation, and alternative splicing of the Vegfa gene produces both proangiogenic isoforms and antiangiogenic isoforms (B-isoforms). The objectives of this study were to evaluate the expression of pro- and antiangiogenic isoforms during testis development and to determine the role of VEGFA isoforms in testis morphogenesis. Quantitative RT-PCR determined that Vegfa_165b mRNA was most abundant between embryonic days 13.5 and 16 (E13.5 and 16; P<0.05). Compared with ovarian mRNA levels, Vegfa_120 was more abundant at E13-14 (P<0.05), Vegfa_164 was less abundant at E13 (P<0.05), and Vegfa_165b tended to be less abundant at E13 (P<0.09) in testes. Immunohistochemical staining localized antiangiogenic isoforms to subsets of germ cells at E14-16, and western blot analysis revealed similar protein levels for VEGFA_165B, VEGFA_189B, and VEGFA_206B at this time point. Treatment of E13 organ culture testes with VEGFA_120, VEGFA_164, and an antibody to antiangiogenic isoforms (anti-VEGFAxxxB) resulted in less organized and defined seminiferous cords compared with paired controls. In addition, 50 ng/ml VEGFA_120 and VEGFA_164 treatments increased vascular density in cultured testes by 60 and 48% respectively, and treatment with VEGFAxxxB antibody increased vascular density by 76% in testes (0.5 ng/ml) and 81% in ovaries (5 ng/ml) compared with controls (P<0.05). In conclusion, both pro- and antiangiogenic VEGFA isoforms are involved in the development of vasculature and seminiferous cords in rat testes, and differential expression of these isoforms may be important for normal gonadal development.
血管内皮生长因子 A（VEGFA）在血管生成和生精索形成中都发挥作用，Vegfa 基因的选择性剪接产生了促血管生成和抗血管生成的同工型（B 同工型）。本研究的目的是评估在睾丸发育过程中促血管生成和抗血管生成同工型的表达，并确定 VEGFA 同工型在睾丸形态发生中的作用。定量 RT-PCR 确定 Vegfa_165b mRNA 在胚胎第 13.5 天至 16 天（E13.5 和 16；P<0.05）之间最丰富。与卵巢 mRNA 水平相比，Vegfa_120 在 E13-14 时更丰富（P<0.05），Vegfa_164 在 E13 时较少（P<0.05），而 Vegfa_165b 在睾丸中 E13 时趋于较少（P<0.09）。免疫组织化学染色将抗血管生成同工型定位在 E14-16 的生殖细胞亚群中，Western blot 分析显示此时 VEGFA_165B、VEGFA_189B 和 VEGFA_206B 的蛋白水平相似。用 VEGFA_120、VEGFA_164 和抗血管生成同工型抗体（抗-VEGFAxxxB）处理 E13 器官培养睾丸导致与配对对照相比，生精索更不规整。此外，50ng/ml VEGFA_120 和 VEGFA_164 处理分别使培养睾丸中的血管密度增加 60%和 48%，而用 VEGFAxxxB 抗体处理使睾丸中的血管密度增加 76%（0.5ng/ml）和卵巢中的血管密度增加 81%（5ng/ml）与对照组相比（P<0.05）。总之，促血管生成和抗血管生成的 VEGFA 同工型都参与了大鼠睾丸中血管和生精索的发育，这些同工型的差异表达可能对正常性腺发育很重要。
