Mitochondrial tRNA^leu(UUR) gene mutation and the decreased activity of cytochromec oxidase in preeclampsia

Summary

To explore the roles of mitochondria tRNA^leu(UURgene mutation at nucleotide 3243 and the activity of cytochromec oxidase in pathogenesis of preeclampsia, 57 patients with preeclampsia and 60 normotension pregnancy women were screened for tRNA^leu(UUR) nt3243 A→G mutation with the method of polymers chain reaction (PCR) and restriction fragment length polymorphism. Cytochromec oxidase activity was determined by measuring the rate of cyanidesensitive oxidation of reduced cytochromec using luminosity photographer. The results showed that cytochromec oxidase activity was significantly lower in the preeclampsia group (0.30±0.39/min, n= 32) than that in the controls (0.73± 0.54/min,n = 26, P<0.01). The mitochondria DNA mutation at position 3243 was not found in our series. The results suggested that the decreased activity of cytochromec oxidase might impair the energy production, leading to the mitochondria dysfunction and placenta dysfunction in preeclampsia patients. Mitochondria dysfunction may be involved in the pathogenesis of preeclampsia. The mutation of mitochondria DNA may not be the common contributor of preeclampsia in our series.