MRNA expression of VEGF and its receptors in fallopian tubes of women with ectopic pregnancies

ABSTRACT

Establishment of viable pregnancy requires embryo implantation and placentation. Ectopic pregnancy [EP] is a pregnancy complication which occurs when an embryo implants outside of the uterine cavity, most often in a fallopian tube. On the other hand, an important aspect of successful implantation is angiogenesis. Vascular endothelial growth factor [VEGF] is a potent angiogenic factor responsible for vascular development that acts through its receptors, VEGF receptor 1 [VEGFR1] and VEGFR2. This study aims to investigate mRNA expression of VEGF and its receptors in fallopian tubes of women who have EP compared with fallopian tubes of pseudo-pregnant women. We hypothesize that expression of VEGF and its receptors in human fallopian tubes may change during EP. This was a case-control study. The case group consisted of women who underwent salpingectomy because of EP. The control group consisted of women with normal fallopian tubes that underwent hysterectomy. Prior to tubal sampling, each control subject received an injection of human chorionic gonadotropin [hCG] to produce a state of pseudo-pregnancy. Fallopian tubes from both groups were procured. We investigated VEGF, VEGFR1 and VEGFR2 mRNA expressions in different sections of these tubes [infundibulum, ampulla and isthmus] by reverse transcription polymerase chain reaction [RT-PCR] and quantitative PCR [Q-PCR]. RT-PCR showed expressions of these genes in all sections of the fallopian tubes in both groups. Q-PCR analysis revealed that expressions of VEGF, VEGFR1 and VEGFR2 were lower in all sections of the fallopian tubes from the case group compared to the controls. Only VEGFR2 had higher expression in the ampulla of the case group. Decreased expressions of VEGF, VEGFR1 and VEGFR2 in the EP group may have a role in the pathogenesis of embryo implantation in fallopian tubes