FEMALE REPRODUCTIVE TRACT - B
Wednesday, August 4, 2004
10:30 AM–12:30 PM
(824) EFFECTS OF ESTROGEN ON EXPRESSION OF BASIC FIBROBLAST GROWTH FACTOR (FGF-2), ENDOTHELIAL CELL NITRIC OXIDE SYNTHASE (eNOS) AND THEIR RECEPTORS, AND HYPOXIA-INDUCIBLE FACTOR (HIF1) IN THE ENDOMETRIUM OF OVARIECTOMIZED (OVX) EWES.
Johnson, Mary Lynn1, 2, Grazul-Bilska, Anna1, 2, Reynolds, Lawrence1, 2, Redmer, Dale1, 2, 1 North Dakota State University, Fargo, ND2 North Dakota State University, Fargo, ND
ABSTRACT- In OVX ewes treated with estradiol (E2), VEGFR-1 mRNA increased in parallel with increased VEGF mRNA, while VEGFR-2 mRNA remained constant (Johnson et al., Biol. Reprod. 68; Suppl. 1: 263; 2003). To evaluate the effects of E2 on expression of FGF-2, eNOS, their receptors, and HIF1 using the same OVX sheep model, endometrial caruncular (CAR) and intercaruncular (ICAR) tissues were obtained at 0, 2, 4, 8, 16, and 24 h after placing a subcutaneous E2 implant (100 mg in Silastic) into long-term OVX ewes (n=4-6 per group). Expression of mRNA for eNOS and its receptor soluble guanylate cyclase (sGC), FGF-2 and its receptor FGFR2 IIIc, and HIF1 were quantified by real time RT-PCR using the ABI Prism 7000 sequence detection system, ovine-specific oligonucleotide probes and primers, and the protocols and solutions supplied by Applied Biosystems (Primer Express, Foster City, CA). Values were compared to 0 h for all genes evaluated. Expression of eNOS mRNA in CAR and ICAR increased by >2-fold at 2 h (P<0.01), >13-fold at 4 through 8 h (P<0.01), 6- to 8-fold at 16 h (P<0.05), and >3-fold at 24 h. In CAR, expression of sGC increased by >3-fold (P<0.01) at 4 h, >9-fold (P<0.01) at 8 h, and remained at >2-fold (P<0.01) at 16 through 24 h, whereas in ICAR, sGC expression was increased by >6-fold (P<0.01) at 8 h and >2-fold (P<0.01) at 16 h. Expression of mRNA for FGF-2 increased in both CAR and ICAR by >3-fold (P<0.01) at 2 h, 4-fold (P<0.01) at 8 through 16 h, and 2- to 3- fold (P<0.01) at 24 h after E2. Expression of mRNA for FGFR2 IIIc was unchanged in CAR from 2 to 24 h, whereas in ICAR the mRNA increased by 2-fold (P<0.05) at 2 h and was unchanged at 4 through 24 h after E2. Expression of mRNA for HIF1 increased in both CAR and ICAR by >3-fold (P<0.01) at 4 h, >4-fold (P<0.01) at 8 through 16 h, and >3-fold (P<0.01) at 24 h after E2. E2 increased expression of eNOS, sGC, and FGF-2 mRNA, but had minimal effects on FGFR2 IIIc expression. HIF1 expression paralleled the effects of E2 on eNOS and FGF-2. Thus, E2 up-regulates several major angiogenic factors in the endometrium of sheep. By using this model, we may begin to understand how angiogenic factors interact to mediate the effects of E2 on endometrial tissues. Supported in part by NIH grant HL64141 to LPR and DAR.
KEY WORDS: endometrium, gene expression, sheep, angiogenesis