Abstract: Objective To investigate inhibition effect of KiSS-1 gene on the trophoblast cell in order to explore the role of high expression of KiSS-1 gene in pregnancy induced hypertension syndrome. Methods Thirty pregnant Wistar rats were divided into three groups randomly with 10 rats in each group. Group A （pcDNA3-KiSS-1 treated group） was transferred recombinant eukaryotic expression vector pcDNA3-KiSS-l encapsulated with lipofectamine by intraperitoneal injection on day 0.5, day 7.5 and day 14.5 of gestation respectively. Group B （pcDNA3 treated group） was transferred pcDNA3 encapsulated with lipofectamine by intraperitoneal injection at the same day. Group C （control group） was injected 0.9% sodium chloride solution at the same day. Blood pressure and urinary protein were assessed serially. All rats were sacrificed on day 21.5 of gestation. Amount of pup, pup weight and weight of placenta were measured. Expression of KiSS-lmRNA and MMP-9niRNA in placenta were determined by reverse transcription- polymerase chain reaction （RT-PCR）.Placenta, uterus attached to placenta, kidney, heart and liver were examined histologically. Results（1） Compared with Group B and Group C, Blood pressure in Group A began rise in day 15.5 of gestation （P＜0.05）, gradually increased to peak levels until delivery. （2）Group A show increased urinary protein in day 14.5 of gestation and persisted to delivery. Daily urinary protein in Group was significantly higher than that in Group B and C （P＜0.01） (3) Pup weight in Group A was significantly lighter than that in Group B and C （P＜0.05）, and resorbed pups were observed in Group A.（4） Expression of KiSS-lmRNA was positive in 7 of 10 placenta in Group A, all in Group B and C was negative. Expression of MMP-9mRNA in placenta was significantly decreased in Group A compared with that of Group B and C （P＜0.05）.（5）Histological exami-nation show proliferation of the glomerular tufts and thickening of media of the kidney arteriolar wall in Group A compared with Group B and C. There was no significant difference in placenta, uterus attachment to placenta, heart, liver among three group. Conclusion The pcDNA3-KiSS-l vector encapsulated by lipofectamine was transfected and integrated into pregnancy Wistar rats. Expression of KiSS-lmRNA was positive in 7 of 10 pcDNA3-KiSS-1-treated rats while negative in pcDNA3-treated and control. pcDNA3-KiSS-1-treated rats exhibited the feature of preeclampsia including hypertension and proteinuria. It suggests that over expression of KiSS-1 cause deficiency of invasion of trophoblast and insufficient of remodeling of spiral arteries in placenta. It may play main role in shallow implantation of placenta in pregnancy induced hypertension syndrome.

Key words: KiSS-1 gene, Pregnancy induced hypertension, Trophoblast, Invasion