Vascular Endothelial Mitochondrial Oxidative Stress in Response to Placental Macrophages from Preeclamptic Pregnancies

Preeclampsia (PE), a hypertensive disorder of pregnancy characterized by maternal hypertension, fetal growth restriction (FGR), and chronic immune activation and inflammation, is a major cause of maternal and fetal morbidity and mortality worldwide. Prior clinical studies demonstrate that proinflammatory M1 macrophages are increased in women with PE. We do not understand the role that M1 macrophage polarization may play in PE pathophysiology. We set out to begin characterization of macrophages in patient samples obtained from the UMMC biobank and their ability to induce mitochondrial oxidative stress (ROS) in human umbilical vein endothelial cells (HUVECs). After obtaining informed consent, whole blood and placental tissues were collected from normal pregnant (n=5) and preeclamptic women (n=8) who delivered in the labor and delivery unit UMMC. Lymphocytes were isolated from blood on a Ficoll-Histopaque gradient and analyzed by flow cytometry for total and M1 macrophages. Total macrophages were isolated from digested placental tissue by magnetic bead separation using the Human Macrophage Isolation Kit (Miltenyi). Isolated macrophages were co-cultured with HUVECs overnight. After removal of culture inserts containing macrophages, HUVECs were serum-starved and incubated with MitoSox Red, collected, and analyzed on a flow cytometer. Total circulating macrophages were increased in placentas from PE women vs normal pregnant patients (10.8% PMBCs vs. 3.5% PMBCs, respectively, p<0.05). Furthermore, macrophage polarization to M1 macrophages was significantly higher in women with PE (15.02% of total macrophages) compared to NP women (6.23% of total macrophages, p<0.05 vs. PE). We also determined that mitochondrial ROS production was significantly elevated in HUVEC cells co-cultured with macrophages from PE pregnancies (15.37 A.U.) when compared to HUVECs co-cultured with normal pregnant control macrophages (7.788 A.U., p<0.05 vs. PE). Future studies will include enrollment of additional participants and determination of endothelial activation by measurement of adhesion molecules, growth factors, extracellular matrix proteins, and cytokines in HUVECs and conditioned media via Western Blot, ELISA, and multiplex analysis. These data show that PE placental macrophages induce mitochondrial ROS production in endothelial cells and may play a role to directly induce vascular dysfunction contributing to hypertension during a preeclamptic pregnancy. This work was supported by National Institutes of Health Grants T32HL105324 to C. A. Shields, and R01HL151407 to D. C. Cornelius. 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.