Mitochondrial Localization of AQP9 in Preeclamptic Placentas

FERNANDEZ NAZARENA; SIERRA MATÍAS N; SZPILBARG NATALIA; FAVALE NICOLÁS; MARTÍNEZ NORA; DAMIANO, ALICIA

CIUDAD DE BUENOS AIRES

Congreso; Society for Redox Biology and Medicine; 2023

OBJECTIVE:Preeclampsia is a gestational hypertensive disorder where increased oxidative stress leads to mitochondrial dysfunction, trophoblast apoptosis, and placental insufficiency. During the syncialization, trophoblast mitochondria undergo morphological and functional changes resulting in two mitochondria subpopulations the "heavy/large" fraction related to ATP production and the "light/small" one associated with ROS production.Previously, we described an increase in AQP9 expression in the trophoblast membranes of preeclamptic placentas. However, its function is unknown. Emerging evidence shows that AQP9 may act as peroxyporin. Recently, we found that AQP9 also localizes in the trophoblast mitochondria of normal placentas with a high expression in the “heavy/large” mitochondrial fraction whereas it was almost undetectable in the "light/small" one. Here, we aimed to study the localization of AQP9 in the preeclamptic trophoblasts. MATERIALS AND METHODS: Placentas were obtained from healthy-term (n=6) and preeclamptic (n=6) pregnancies. Microsomal and the two mitochondrial fractions were isolated from placental tissue by differential centrifugation. The presence of functional mitochondria was evaluated by MitoTracker. AQP9 expression was analyzed by Western blot. Co-localization of AQP9 and cytochrome-C was assessed by double-immunofluorescence and confocal microscopy.RESULTS: AQP9 expression was significantly increased in the microsomal and in heavy/large mitochondrial fraction (p