Expression of VEGF-receptor system in conceptus during peri-implantation period and endometrial and luteal expression of soluble VEGFR-1 in the pig.
In view of the importance of vascular events observed during gestation, it was hypothesized that the VEGF-receptor system plays a critical role during early pregnancy and maternal recognition of pregnancy in pigs. This hypothesis was tested by examining the expression of the VEGF-receptor system in the porcine conceptus. Additionally, the endometrium, corpus luteum (CL) and embryos were studied for the expression of soluble VEGF receptor 1 (sVEGFR-1), the strong endogenous antagonist of VEGF. The expression patterns show that VEGF164 mRNA levels increase gradually in line with conceptus development, whereas VEGF120 and VEGFR-2 remain unchanged during the peri-implantation period. Interestingly, elevated VEGFR-1 expression was observed in conceptuses on days 15-16 of gestation (P<0.05). Comparison of the endometrial sVEGFR-1 mRNA expression revealed up-regulation on days 12 and 15-16 of pregnancy (P<0.01 and P<0.05, respectively). Furthermore, increased sVEGFR-1 levels were observed on day 12 of the estrous cycle in the CL (P<0.05). Concluding, it seems that conceptus-derived VEGF164 plays crucial role in peri-implantation vascular events in pigs. These results support a potential role of VEGFR-1 in the proper growth and development of porcine conceptus during pregnancy. Moreover, expression patterns of sVEGFR-1 in the endometrium of pregnant pigs suggest that it may participate in vascular remodeling important for successful implantation. Finally, luteal sVEGFR-1 may be involved in the maintenance of CL function whenever pregnancy occurs in pigs.
Kaczmarek
M M
MM
Institute of Animal Reproduction and Food Research Polish Academy of Sciences (IARFR PAS), Tuwima 10, 10-747 Olsztyn, Poland. moka@pan.olsztyn.pl
Kiewisz
J
J
Schams
D
D
Ziecik
A J
AJ
D000818:Animals; D001755:Blastocyst / Q000378:metabolism*; D003338:Corpus Luteum / Q000378:metabolism; D010064:Embryo Implantation / Q000235:genetics*; D004717:Endometrium / Q000378:metabolism*; D005260:Female; D008184:Luteal Cells / Q000378:metabolism*; D011247:Pregnancy; D040262:Receptors, Vascular Endothelial Growth Factor / Q000235:genetics* / Q000378:metabolism; D012995:Solubility; D013552:Swine / Q000235:genetics* / Q000378:metabolism; D040281:Vascular Endothelial Growth Factor Receptor-1 / Q000235:genetics / Q000378:metabolism
D040262:Receptors, Vascular Endothelial Growth Factor; D040281:Vascular Endothelial Growth Factor Receptor-1