ABSTRACT
INTRODUCTION: Placental mitochondrial dysfunction contributes to the oxidative stress that underlies preeclampsia. Here, we assessed whether sulforaphane (SFN) could improve syncytiotrophoblast mitochondrial function after in vitro hypoxic and superoxide injury. METHODS: Placental cytotrophoblasts were isolated from healthy term placentae (n = 12) and incubated for 48 h in 8% O2 ± 1 µM SFN before acute (4hrs) or chronic (24hrs) hypoxic (1% O2), or superoxide (xanthine/xanthine oxidase) injury. Cytotrophoblasts were also isolated from preeclamptic placentae (n = 5) and cultured in 8% O2 ± 1 µM SFN. Mitochondrial respiration was measured using the Seahorse MitoStress XF assay. Cells were stained with mitotracker red to assess mitochondrial membrane health and mitochondrial gene expression assessed using RT-qPCR. RESULTS: SFN prevented significant reductions in syncytiotrophoblast mitochondrial maximal respiration, spare respiratory capacity, basal respiration and ATP production following acute hypoxia. Chronic hypoxia only reduced maximal and spare respiratory capacity. SFN prevented these negative changes and increased respiration overall. Alternatively, acute superoxide injury significantly increased mitochondrial maximal respiration and spare respiratory capacity. SFN treatment further increased basal respiration following superoxide injury and prevented significant decreases in ATP production and coupling efficiency. In preeclamptic placentae, SFN significantly increased mitochondrial maximal respiration, spare respiratory capacity, basal respiration and ATP production, and decreased proton leak. SFN up-regulated mRNA expression of mitochondrial complexes and corrected an up-regulation in fission gene expression observed after hypoxic-superoxide injury. Finally, preliminary results suggest SFN prevented hypoxia-induced impairment of mitochondrial membrane structure. DISCUSSION: SFN mitigated hypoxia and superoxide induced changes to syncytiotrophoblast mitochondrial function in vitro, and improved mitochondrial respiration in trophoblast cells from preeclamptic placentae.
Subject(s)
Antioxidants/pharmacology , Cell Hypoxia/drug effects , Isothiocyanates/pharmacology , Mitochondria/drug effects , Oxidative Stress/drug effects , Sulfoxides/pharmacology , Superoxides/pharmacology , Trophoblasts/drug effects , Adult , Female , Humans , Mitochondria/metabolism , Placenta/drug effects , Placenta/metabolism , Pregnancy , Trophoblasts/metabolismABSTRACT
The levels of GSH-related enzyme activities during pregnancy were determined. A significant increase in Selenium-dependent GSH peroxidase and GSH S-transferase E activity was observed. A concomitant increase in gamma-glutamylcysteine synthetase was measured, which indicated an increased ability to synthesize the tripeptide.
Subject(s)
Glutathione/metabolism , Liver/enzymology , Pregnancy, Animal , Animals , Female , Glutamate-Cysteine Ligase/metabolism , Glutathione Peroxidase/metabolism , Glutathione Transferase/metabolism , Isoenzymes/metabolism , Pregnancy , Rats , Rats, Inbred Strains , Selenium/pharmacology , Substrate SpecificityABSTRACT
GSH peroxidase, GSSG reductase, GSH S-transferase, and gamma-glutamyltranspeptidase activities were measured in the supernatant of 13 human early pregnancy placenta homogenates. From measurements of GSH peroxidase activity with both H2O2 and cumene hydroperoxide as second substrate it was deduced that immature placenta contains only the Se-dependent form. All the specimens investigated exhibited GSSG reductase and gamma-glutamyltranspeptidase activities. GSH S-transferase activity was noted only using 1-chloro-2,4-dinitrobenzene as electrophilic substrate, while no detectable activity was found with 1,2-dichloro-4-nitrobenzene, 1,2-epoxy-3-(p-nitrophenoxy) propane, and p-nitrobenzylchloride. It is concluded that human placenta is equipped, from early pregnancy, with the enzymatic systems which are involved in GSH-mediated cellular detoxication and in preserving the integrity of the sulfhydryl status of the cells.
