Leptin Induces Evidence of Placental Mitochondrial Dysfunction in a Mouse Model of Preeclampsia

Abstract

Preeclampsia (PE) affects 5-10% of pregnancies worldwide that increase maternal and fetal morbidity and mortality. PE is often characterized by hypertension, endothelial dysfunction, and restriction of intrauterine fetal growth. Our lab established that mid-gestation leptin infusion in pregnant mice induces a model of PE, notably reducing fetal growth in late gestation. Clinical studies indicate that PE patients demonstrate elevated levels of leptin compared to healthy pregnancies as well as present with evidence of placental mitochondrial dysfunction. Therefore, we hypothesize that mid-late gestation leptin infusion induces placental mitochondrial dysfunction in pregnant mouse placenta. We infused timed-pregnant C57/Bl6 mice with saline (sham) or leptin (0.9 mg/kg/day) via s.c. osmotic minipump from gestation day (GD)11-18 (n=4-8). We collected placentas on GD18 for analysis. We isolate mitochondria from mouse placenta via differential centrifugation, after douncing pulverized tissue. From the isolated mitochondria, we assessed morphology via electron microscopy (EM) and performed amplex red assay for reactive oxygen species (ROS) measurements and tetramethyl rhodamine methyl ester (TMRM) dye was used to measure membrane potential. Pairwise comparisons were by student’s t-test. Our data indicates that leptin decreased membrane potential in placenta mitochondria compared to the sham placentas (1466±16.42 sham vs 1353±32.48 leptin A.U./mg of protein, **p<0.01). In comparison, there were no differences in H2O2 production between the sham and leptin-infused placental mitochondrial isolations (7381±125.2 leptin vs 7311±180.3 sham A.U./mg of protein). EM analysis of one sham and one leptin placenta indicated an increase in mitophagy in the leptin-infused placenta slices as well as decreased mitochondrial circularity, suggesting that leptin increases mitochondrial death. In summary, these data indicate that leptin induces mitochondrial dysfunction which in turn may contribute to placental dysfunction and reduced uteroplacental fetal growth in PE. 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.