INCREASED MITOCHONDRIAL DAMAGE BY LIPID-PEROXIDATION IN TROPHOBLAST CELLS OF PREECLAMPTIC PLACENTAS

Lipid peroxides and their related free radicals have been implicated i n the pathogenesis of placental dysfunction in preeclampsia. Recent st udies suggest that the placenta is a source of the increased lipid per oxides in the maternal circulation of women with preeclampsia. We exam ined intracellular localization of 4-hydroxy-2-nonenal (HNE: a major a ldehydic product of lipid peroxidation)-modified proteins in human pla centas by immunohistochemistry, and immunoblotting. The trophoblast la yer of the chorionic villi showed intense immunoreactivity for HNE-mod ified proteins in 4 of 12 preeclamptic placentas, whereas no staining was observed in 12 normal placentas. Immunoblotting revealed that thre e immunoreactive proteins with apparent molecular mass of 110 kDa, 75 kDa, and 70 kDa were localized in the mitochondrial fraction. The pres ent results indicate that the damage to mitochondrial proteins by lipi d peroxidation byproducts and subsequent dysfunction of trophoblasts c ontribute to the pathophysiology of preeclampsia.