ABSTRACT
We evaluated the efficacy, safety, and biological mechanisms of digoxin immune Fab (DIF) treatment of severe preeclampsia. Fifty-one severe preeclamptic patients were randomized in double-blind fashion to DIF ( N = 24) or placebo ( N = 27) for 48 hours. Primary outcomes were change in creatinine clearance (CrCl) at 24 to 48 hours and antihypertensive drug use. Serum sodium pump inhibition, a sequela of endogenous digitalis-like factors (EDLF), was also assessed. CrCl in DIF subjects was essentially unchanged from baseline versus a decrease with placebo (-3 +/- 10 and -34 +/- 10 mL/min, respectively, P = 0.02). Antihypertensive use was similar between treatments (46 and 52%, respectively, P = 0.7). Serum sodium pump inhibition was decreased with DIF compared with placebo at 24 hours after treatment initiation (least squares mean difference, 19 percentage points, P = 0.03). DIF appeared to be well tolerated. These results suggest DIF prevents a decline in renal function in severe preeclampsia by neutralizing EDLF. Sodium pump inhibition was significantly improved. Further research is warranted.
Subject(s)
Antihypertensive Agents/administration & dosage , Immunoglobulin Fab Fragments/administration & dosage , Pre-Eclampsia/drug therapy , Adult , Antihypertensive Agents/adverse effects , Cardenolides/blood , Digoxin/immunology , Double-Blind Method , Female , Humans , Immunoglobulin Fab Fragments/analysis , Kidney Function Tests , Pre-Eclampsia/blood , Pre-Eclampsia/diagnosis , Pre-Eclampsia/physiopathology , Pregnancy , Pregnancy Outcome , Saponins/blood , Sodium-Potassium-Exchanging ATPase/antagonists & inhibitors , Treatment Outcome , Young AdultABSTRACT
We tested the hypothesis that epidermal growth factor (EGF) limits hypoxia-induced apoptosis in cultured human trophoblasts by phosphorylation of the proapoptotic protein Bcl-2-associated death promoter (BAD). Cytotrophoblasts were isolated from placentas of uncomplicated pregnancies at 38-40 wk gestation. Primary trophoblasts or transfected JEG3 trophoblast cells were cultured in less than 1 or 20% oxygen in the presence or absence of EGF and signaling pathway inhibitors. BAD, green fluorescent protein (GFP)-BAD, 14-3-3, Bcl-X(L), and neoepitopes formed during apoptotic cleavage of cytokeratin 18 intermediate filaments were quantified using immunoblotting. Cultures immunostained by fluorescent antibodies were analyzed by confocal microscopy for BAD and GFP. Fluorescence resonance energy transfer was used to detect molecular interaction between endogenous BAD and GFP-BAD. We found EGF increased the phosphorylation of BADser112 under standard culture conditions. Whereas hypoxia enhanced apoptosis and increased phosphorylation of both BADser136 and BADser155, hypoxia diminished phosphorylation of BADser112, and this effect was reversible by EGF. Transfected GFP-BAD, which directly interacted with endogenous BAD by colocalization and fluorescence resonance energy transfer, enhanced hypoxia-induced apoptosis in JEG3 cells. EGF reduced apoptosis in hypoxic JEG3 cells that overexpressed GFP-BAD but not in cells overexpressing GFP-BAD that harbored a serine-to-alanine mutation at the 112 site. Coimmunoprecipitation studies showed that EGF reduced the proapoptotic interaction of BAD with Bcl-X(L). The effect of EGF on phosphorylation of BADser112 was dependent on the action of p38 MAPK. We conclude that EGF signals via p38 MAPK to increase phosphorylation of BADser112 and thereby limit trophoblast apoptosis.
Subject(s)
Apoptosis/drug effects , Cell Hypoxia/drug effects , Epidermal Growth Factor/pharmacology , Trophoblasts/drug effects , bcl-Associated Death Protein/metabolism , Cell Hypoxia/physiology , Cells, Cultured , Epidermal Growth Factor/metabolism , Female , Green Fluorescent Proteins/genetics , Green Fluorescent Proteins/metabolism , Humans , Phosphorylation/drug effects , Pregnancy , Protein Binding , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , Serine/metabolism , Signal Transduction/drug effects , Transfection , Trophoblasts/metabolism , bcl-Associated Death Protein/genetics , p38 Mitogen-Activated Protein Kinases/metabolismABSTRACT
OBJECTIVE: The purpose of this study was to test the hypothesis that the thiazolidinedione troglitazone, a peroxisome proliferator activated receptor-gamma ligand, attenuates hypoxia-induced trophoblast injury. STUDY DESIGN: Cytotrophoblasts from 4 term human placentas were cultured in the presence or absence of 10 mumol/L troglitazone in either 20% oxygen (standard conditions) or 1% oxygen (hypoxic conditions) for variable periods before cell harvest. Medium beta-human chorionic gonadotropin and human placental lactogen were analyzed by enzyme-linked immunosorbent assay. Apoptosis was quantified by cytokeratin-18 cleavage products staining; p53 expression was examined by Western blot analysis. RESULTS: beta-human chorionic gonadotropin and human placental lactogen levels were >/=2-fold higher in troglitazone-exposed cells at 16 hours of hypoxia, compared with vehicle control cells ( P <.05). The apoptotic index was reduced by >/=30% ( P <.001), and the expression of p53 was 2-fold lower ( P <.02) in troglitazone-exposed cells under hypoxia for 24 hours of low oxygen. CONCLUSION: Troglitazone attenuates the influence of acute hypoxia on cultured term human trophoblasts.
