[Clinical significance of hypoxia inducible factor-prolyl hydroxylase 1 and factor inhibiting hypoxia inducible factor-1 expression in placentas of women with severe pre-eclampsia].

OBJECTIVE: To investigate the role of hypoxia inducible factor (HIF)-prolyl hydroxylase 1 (HPH1) and factor inhibiting HIF-1 (FIH-1) in placentas in the pathogenesis and development of severe pre-eclampsia.

METHODS: RT-PCR and western blot analyses were used to detect the HPH1 and FIH-1 expression levels in placentas of 34 patients with severe pre-eclampsia and 24 cases of term pregnancy (normal pregnancy group) and their correlations with symptoms were analyzed.

RESULTS: (1) The HPH1 mRNA and protein expression levels in placentas of severe pre-eclampsia group were 0.40 +/- 0.04 and 59.5 +/- 3.4 separately, significantly lower than those of normal pregnancy group, 0.84 +/- 0.12 and 71.6 +/- 1.7 (P < 0.01). The FIH-1 mRNA and protein expression levels in placentas of severe pre-eclampsia group were 0.31 +/- 0.05 and 45.6 +/- 2.4 separately, significantly lower than those of normal pregnancy group, 0.43 +/- 0.04 and 54.9 +/- 2.1 (P < 0.01). (2) The mRNA and protein expression levels of HPH1 and FIH-1 in severe pre-eclampsia group were all negatively correlated with mean arterial pressure (MAP) [the Spearman correlation coefficient was -0.854 (P < 0.01)], urinary protein per 24 hours [the Spearman correlation coefficient was -0.936 (P < 0.01)] and the occurrence of fundus oculi artery spasm [the Spearman correlation coefficient was -0.854 (P < 0.01)]. (3) The expression of HPH1 mRNA in placentas of all the 58 cases was 0.58 +/- 0.27, higher than the expression of FIH-1 mRNA, which was 0.39 +/- 0.10. There was a positive correlation between them. The pearson correlation coefficient was 0.686 (P < 0.01). The expression of HPH1 protein in placentas of all the 58 cases was 64.5 +/- 6.7, higher than the expression of FIH-1, which was 49.4 +/- 5.2. There was a positive correlation between them. The Pearson correlation coefficient was 0.947 (P < 0.01).

CONCLUSION: The expression imbalance of HPH1 and FIH-1 in placenta may play an important role in the pathogenesis and development of severe pre-eclampsia through inhibiting HIF-1alpha.