Background and purpose: Preeclampsia is a major obstetric problem of unknown etiology. The fact that removal of the placenta is the only cure for preeclampsia, has led to the well-established hypothesis, that the placenta is central in the etiology. Gene profiling and proteomics studies have suggested oxidative stress caused by reperfusion and free oxygen radicals as a potential pathophysiological mechanism in preeclampsia. In this study, the dual placental perfusion model was used in order to evaluate the damaging effects of oxidative stress induced by xanthine/xanthine oxides and free hemoglobin.
Material and methods: The dual placenta perfusion model is a well-established in vitro model for functional placental studies. Placentas were perfused with medium containing either xanthine/xanthine oxidase or erythrocytes as a source of free hemoglobin. Concentration of free hemoglobin in the medium was measured by means of ELISA. Whole genome microarray technique and bioinformatics were used to evaluate the gene expression profile in the two groups.
Results: Substantial levels of free adult hemoglobin were detected in the perfusions. A total of 58 genes showed altered gene expression, the most altered were hemoglobin alpha, beta and gamma, tissue factor pathway inhibitor 2 and superoxide dismutase 2. Bioinformatics revealed that biological processes related to oxidative stress, anti-apoptosis and iron ion binding were significantly altered.
Conclusions: The results suggest that perfusion with xanthine/xanthine oxidase and free hemoglobin induce changes in gene expression similar to what has been described for the preeclamptic placenta.