Eplerenone Reduces Blood Pressure and Improves Vascular Function in a Mouse Model of Leptin-induced Preeclampsia

Abstract

Preeclampsia is a hypertensive pregnancy disease that increases the risks for adverse outcomes of pregnancy for both mother and baby, notably by reducing fetal growth in utero. We have shown that mid-late gestation leptin infusion induces preeclampsia characteristics in pregnant mice in inducing hypertension, endothelial dysfunction, and fetal growth restriction, which is ablated in mice with endothelial mineralocorticoid receptor deletion (ECMR). However, there is a lack of preclinical data and rationale for MR antagonism for use in preeclampsia in the existing literature. Therefore, we hypothesized that leptin increases ECMR expression and that MR antagonism decreases hypertension, endothelial dysfunction, and fetal growth restriction in leptin-induced preeclamptic mice. We infused timed-pregnant Balb/C mice with saline (sham) or leptin (LEP, 0.9 mg/kg/day) via s.c. osmotic minipump and administered vehicle or eplerenone (EPL, 200mg/kg/day) in drinking water from gestation day (GD)11-18 (n=7-12). We measured mean arterial blood pressure (BP) via radiotelemetry, vascular function in 2nd order mesenteric arteries by wire myography, and pup/placental weights on GD18. We isolated endothelial cells from placentas of our mice via magnetic cell sorting. Pairwise comparisons were by student’s t test and myography curves analyzed by 2-W ANOVA w/RM. Leptin increased ECMR mRNA expression (3.1±0.32 WT LEP vs 1.1±0.48 WT sham, fold change, *p<0.05) compared to WT sham mice in placenta indicating a direct role for leptin to upregulate ECMR in pregnancy. EPL ablated leptin-induced increases in BP (98±4 LEP/EPL vs 113±3 lep/veh mmHg, *p<0.05), and when treated with EPL leptin did not induce endothelial dysfunction, as assessed as a lack of decrease in vascular relaxation to acetylcholine (p>0.05 LEP/EPL vs sham/EPL). Interestingly, EPL treatment did not prevent leptin from decreasing placental effciency in pregnant mice (7.42±0.17 LEP/veh vs 6.71±0.15 LEP/EPL, pup/placenta weight ratio, p>0.05). Collectively, these data show that leptin infusion from GD11-18 in pregnant mice increases ECMR activation by increasing expression. Furthermore, MR antagonism by eplerenone ablates the maternal hypertension and endothelial dysfunction in leptin-induced preeclampsia mice, however, fetal growth is not restored by eplerenone. Therefore, eplerenone may be a promising therapeutic for the maternal cardiovascular syndrome of preeclampsia patients, however, MR antagonism therapies may need additional agents to improve fetal outcomes. 1R01HL169576, 4R00HL146948. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.