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DIFFERENTIAL EXPRESSION OF VASCULAR ENDOTHELIAL GROWTH FACTOR AND BASIC FIBROBLAST GROWTH FACTOR IN BOVINE UTERUS AND PLACENTA.
Kizaki, Keiichiro1, Nakano, Hiroko1, Takahashi, Toru1, Imai, Kei1, Takezawa, Toshiaki1, Todoroki, Junichi2, Fuchimoto, Daiichiro1, Izaike, Yoshiaki1, Hashizume, Kazuyoshi1, 1 2
ABSTRACT- Angiogenesis is an important phenomenon during implantation and placental development. Vascular endothelial growth factors (VEGFs) and basic fibroblast growth factor (bFGF) are potent angiogenic factors, and play important roles in physiological and pathological angiogenic events. However, in cow, the expression and roles of angiogenic factors in uterus and placenta during gestation are remain to clarify. In the present study, the expression of VEGFs and bFGF were examined in bovine uterine endometrium and placenta during gestation. Total RNA was isolated from uterine (caruncle; CAR and intercaruncular endometrium; ICAR) and placental (cotyledon; COT, intercotyledonary fetal membrane; ICOT) tissues around 20, 30, 60, 100, 250 days of gestation (n=3-5/each stage) and the first half of estrous cycle (n=4). VEGFs and bFGF were analyzed by northern blot and quantitative real time RT-PCR (TaqMan assay). Northern blot analysis showed that VEGFs were found all tissues in fetal and maternal sides on day 30 of gestation. On the other hand, bFGF was expressed in only maternal side (CAR and ICAR) on day 30. TaqMan assay showed that VEGF are detected in all area on uterine and/or placental tissues from day 20 to 260 of gestation and estrous cycle. Although, the expression of VEGFs in CAR and COT were increased gradually with the progression of gestation, no differences were observed in ICAR and ICOT. Very low level of bFGF was expressed in fetal membrane throughout gestation, and higher expression was detected in endometrium during early gestation and estrous cycle. The specific expression of bFGF in endometrium was followed by diminishing the detection with progression in gestation days. The expression pattern between VEGFs and bFGF in bovine uterine endometrium and placenta during gestation were varied in different manner. These results suggest that bFGF takes an important role for implantation, and VEGFs may participate in placental formation and development. This study was supported by Grants-in-aid from the ORCS, BRAIN and MAFF, Japan.
KEY WORDS: VEGF, bFGF, angiogenesis, cow