Sargent Kevin M, Lu Ningxia, Clopton Debra T, Pohlmeier William E, Brauer Vanessa M, Ferrara Napoleone, Silversides David W, Cupp Andrea S
Department of Animal Science, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America.
University of California San Diego School of Medicine, San Diego, CA, United States of America.
PLoS One. 2015 Feb 6;10(2):e0116332. doi: 10.1371/journal.pone.0116332. eCollection 2015.
Because VEGFA has been implicated in follicle development, the objective of this study was to determine the effects of granulosa- and germ cell-specific VEGFA loss on ovarian morphogenesis, function, and female fertility. pDmrt1-Cre mice were mated to floxed VEGFA mice to develop granulosa-/germ cell-specific knockouts (pDmrt1-Cre;Vegfa-/-). The time from mating to first parturition was increased when pDmrt1-Cre;Vegfa-/- females were mated to control males (P = 0.0008) and tended to be longer for heterozygous females (P < 0.07). Litter size was reduced for pDmrt1-Cre;Vegfa-/- females (P < 0.007). The time between the first and second parturitions was also increased for heterozygous females (P < 0.04) and tended to be increased for pDmrt1-Cre;Vegfa-/- females (P < 0.07). pDmrt1-Cre;Vegfa-/- females had smaller ovaries (P < 0.04), reduced plasma estradiol (P < 0.007), fewer developing follicles (P < 0.008) and tended to have fewer corpora lutea (P < 0.08). Expression of Igf1r was reduced (P < 0.05); expression of Foxo3a tended to be increased (P < 0.06); and both Fshr (P < 0.1) and Sirt6 tended to be reduced (P < 0.06) in pDmrt1-Cre;Vegfa-/- ovaries. To compare VEGFA knockouts, we generated Amhr2-Cre;Vegfa-/- mice that required more time from mating to first parturition (P < 0.003) with variable ovarian size. Both lines had more apoptotic granulosa cells, and vascular staining did not appear different. Taken together these data indicate that the loss of all VEGFA isoforms in granulosa/germ cells (proangiogenic and antiangiogenic) causes subfertility by arresting follicular development, resulting in reduced ovulation rate and fewer pups per litter.
由于血管内皮生长因子A（VEGFA）与卵泡发育有关，本研究的目的是确定颗粒细胞和生殖细胞特异性VEGFA缺失对卵巢形态发生、功能及雌性生育力的影响。将pDmrt1-Cre小鼠与携带floxed VEGFA的小鼠交配，以培育颗粒细胞/生殖细胞特异性敲除小鼠（pDmrt1-Cre;Vegfa-/-）。当pDmrt1-Cre;Vegfa-/-雌性小鼠与对照雄性小鼠交配时，从交配到首次分娩的时间延长（P = 0.0008），杂合子雌性小鼠的该时间也有延长趋势（P < 0.07）。pDmrt1-Cre;Vegfa-/-雌性小鼠的窝仔数减少（P < 0.007）。杂合子雌性小鼠第一次与第二次分娩之间的时间也延长了（P < 0.04），pDmrt1-Cre;Vegfa-/-雌性小鼠的该时间有延长趋势（P < 0.07）。pDmrt1-Cre;Vegfa-/-雌性小鼠的卵巢较小（P < 0.04），血浆雌二醇水平降低（P < 0.007），发育中的卵泡数量减少（P < 0.008），黄体数量有减少趋势（P < 0.08）。pDmrt1-Cre;Vegfa-/-卵巢中胰岛素样生长因子1受体（Igf1r）的表达降低（P < 0.05）；叉头框蛋白O3a（Foxo3a）的表达有增加趋势（P < 0.06）；促卵泡激素受体（Fshr，P < 0.1）和沉默调节蛋白6（Sirt6，P < 0.06）的表达均有降低趋势。为了比较VEGFA敲除小鼠，我们构建了Amhr2-Cre;Vegfa-/-小鼠，其从交配到首次分娩需要更长时间（P < 0.003），卵巢大小不一。两个品系的颗粒细胞凋亡均增多，血管染色无差异。综上所述，这些数据表明，颗粒细胞/生殖细胞中所有VEGFA异构体（促血管生成和抗血管生成）的缺失通过阻止卵泡发育导致生育力下降，从而使排卵率降低，每窝幼崽数量减少。
