Julio-Pieper Marcela, Lara Hernán E, Bravo Javier A, Romero Carmen
Laboratory of Endocrinology and Reproductive Biology, Hospital Clínico Universidad de Chile, Santiago, Chile.
Reprod Biol Endocrinol. 2006 Nov 10;4:57. doi: 10.1186/1477-7827-4-57.
Angiogenesis is a crucial process in follicular development and luteogenesis. The nerve growth factor (NGF) promotes angiogenesis in various tissues. An impaired production of this neurotrophin has been associated with delayed wound healing. A variety of ovarian functions are regulated by NGF, but its effects on ovarian angiogenesis remain unknown. The aim of this study was to elucidate if NGF modulates 1) the amount of follicular blood vessels and 2) ovarian expression of two angiogenic factors: vascular endothelial growth factor (VEGF) and transforming growth factor beta 1 (TGFbeta1), in the rat ovary.
In cultured neonatal rat ovaries, NGF increased VEGF mRNA and protein levels, whereas TGFbeta1 expression did not change. Sectioning of the superior ovarian nerve, which increases ovarian NGF protein content, augmented VEGF immunoreactivity and the area of capillary vessels in ovaries of prepubertal rats compared to control ovaries.
Results indicate that NGF may be important in the maintenance of the follicular and luteal vasculature in adult rodents, either indirectly, by increasing the expression of VEGF in the ovary, or directly via promoting the proliferation of vascular cells. This data suggests that a disruption on NGF regulation could be a component in ovarian disorders related with impaired angiogenesis.
血管生成是卵泡发育和黄体形成过程中的关键环节。神经生长因子（NGF）可促进多种组织中的血管生成。这种神经营养因子的产生受损与伤口愈合延迟有关。NGF可调节多种卵巢功能，但其对卵巢血管生成的影响尚不清楚。本研究的目的是阐明NGF是否调节1）卵泡血管数量，以及2）大鼠卵巢中两种血管生成因子：血管内皮生长因子（VEGF）和转化生长因子β1（TGFβ1）的表达。
在培养的新生大鼠卵巢中，NGF增加了VEGF的mRNA和蛋白水平，而TGFβ1的表达没有变化。与对照卵巢相比，切断增加卵巢NGF蛋白含量的卵巢上神经，可增强青春期前大鼠卵巢中VEGF的免疫反应性和毛细血管面积。
结果表明，NGF可能通过增加卵巢中VEGF的表达间接或直接促进血管细胞增殖，从而对成年啮齿动物卵泡和黄体血管系统的维持起重要作用。该数据表明，NGF调节的破坏可能是与血管生成受损相关的卵巢疾病的一个组成部分。
