Investigation of NRF-1 and NRF-2 expressions in severe and non-severepreeclamptic placentas

Aim: This study aimed to evaluate placental structural changes in pregnancies with preeclampsia (PE) and investigate the roles of NRF1 and NRF2 protein expression levels in mitochondrial damage, cellular degeneration, and apoptotic processes. Materials and Methods: The research was conducted at Dicle University between August and October 2024. The study included 21 mild PE, 21 severe PE, and 21 healthy pregnancies, diagnosed according to ACOG criteria. Placental tissues were examined using histological and immunohistochemical techniques. NRF1 and NRF2 expressions were analyzed by immunostaining, and morphological and molecular findings were compared. Results: In the control group, the chorionic villi were well-organized, the trophoblastic layer maintained integrity, and fibrin accumulation was minimal. In PE groups, villous degeneration, increased syncytial knots, vascular congestion, dilation, and inflammatory cell infiltration were observed. NRF1 expression decreased in PE groups compared to controls, showing negativity especially in syncytial knots and fibrinoid areas. In contrast, NRF2 expression significantly increased in PE groups, showing strong positivity in syncytiotrophoblasts, connective tissue, and vascular structures. Conclusion: The reduction in NRF1 expression in PE may support apoptotic processes related to mitochondrial dysfunction and oxidative stress, while the increase in NRF2 expression suggests activation of cellular adaptation and antioxidant defense mechanisms. These findings shed light on the pathogenesis of PE, highlighting the potential roles of NRF1 and NRF2 as clinical biomarkers and therapeutic targets. Keywords: Preeclampsia, Placenta, Umbilical cord, NRF1, NRF2