[Expression of hypoxia-inducible factor-1alpha, vascular endothelial growth factor and sFlt-1 in preeclampsia...

To investigate the expression and correlation of hypoxia-inducible factor-1alpha (HIF-1alpha), vascular endothelial growth factor (VEGF) and sFlt-1 in the preeclampsia placenta, and discuss their significance in the pathogenesis of preeclampsia.

Placentas were collected from 20 pregnant women with preeclampsia as study group and 15 normal pregnant women as control group. The expressions of HIF-1alpha, VEGF and sFlt-1 protein were semi-quantitatively analyzed with immunohistochemical assay and mRNA level was determined using reverse transcription polymerase chain reaction (RT-PCR) technique.

(1) the expression of HIF-1alpha and sFlt-1 protein in preeclampsia group obviously increased. Strong (+++) positive expression was observed in 9 and 11 cases respectively, significantly higher than in control group (2 and 3 cases) (P < 0.05), however, VEGF expression obviously reduced in preeclampsia group (P < 0.01). (2) the level of HIF-1alpha and sFlt-1 mRNA in preeclamptic placenta was 0.604 +/- 0.013, 0.898 +/- 0.041, significantly higher than 0.208 +/- 0.007 and 0.559 +/- 0.244 in normal placenta (P < 0.05). Although the level of VEGF mRNA increased in preeclampsia placenta, it was not significantly different from that in normal placenta (P > 0.05). The ratio of VEGF mRNA/sFlt-1mRNA obviously reduced in preeclampsia group and was significantly lower than in control group (P < 0.05). (3) in preeclampsia group, HIF-1alpha mRNA expression was positively correlated with the expression of sFlt-1 mRNA (r = 0.577, P < 0.05), and negatively correlated with the ratio of VEGF mRNA/sFlt-1 mRNA (r = -0.376, P < 0.05).

Abnormal high HIF-1alpha expression in preeclampsia placenta indicates that HIF-1alpha might play an important role in the pathogenesis of preeclampsia, possibly through affecting the cytotrophoblastic invasion and placental vascular reconstruction via the modulation of VEGF and sFlt-1 gene transcription.