Thesis presented September 21, 2023

Abstract:
Preeclampsia, a complex hypertensive disorder of pregnancy, is characterized by maternal endothelial dysfunction and uteroplacental/maternal organ dysfunction. It poses risks to both mother and fetus and is a major contributor to global morbidity and mortality. Its pathogenesis involves placental factors, immune dysregulation and multi-organ changes. Biomarkers offer diagnostic insights, and long-term neurological consequences warrant preventive strategies. Meanwhile, prokineticins, the family of small proteins PROK1 and PROK2 that bind to 2 G-protein coupled receptors PROKR1 and PROKR2, have multiple physiological roles and therapeutic potential. Disorders in this system are associated with infertility, ovarian disorders, endometriosis and preeclampsia. Both fields emphasize the importance of understanding prokineticin signaling mechanisms and their disease implications, noting common features between preeclampsia and the prokineticin system - immune dysregulation, multi-organ involvement, and therapeutic promise.
The aim of this dissertation project was to investigate the role of the prokineticin system in the maternal brain during preeclampsia. Two main studies were performed, the aim of the first study was to investigate the effects of PROK1 and PROK2 on murine cerebral cell lines, i.e. microvascular endothelial cells, astrocytes and neurons, and on an established murine BBB co-culture model. The results showed that PROKRs were differentially expressed in the cell lines, with negligible expression of PROKR1 in neurons. The effect of PROKs on cell proliferation and migration was assessed using time-lapse microscopy. PROK1 decreased neuronal proliferation, while it had no effect on endothelial cells and astrocytes. In contrast, PROK2 reduced the proliferation of all cell lines tested. Both PROK1 and PROK2 increased migration of the various cell lines, and blocking PROKRs with anti-PROKR1 (PC7) and anti-PROKR2 (PKR-A) inhibited astrocyte migration induced by PROK2. In addition, using insert co-culture model of BBB, PROKs increased BBB permeability, which could be prevented by PROKRs antagonists.
Then, the second part was to investigate the alteration of cerebral PROKs system and its relationship with brain complications using PE transgenic mice model (STOX1), with or without treatment with PROKR antagonist, PC1. Results showed elevated blood pressure, proteinuria and PROKs levels in PE blood, which were effectively prevented by PC1 treatment. MRI studies showed hemorrhagic and non-hemorrhagic lesions in PE mice at 8 months postpartum. These lesions were not observed in PC1-treated PE mice. Altered expression patterns of PROK1, PROK2, PROKR1 monomer and oligomers, and PROKR2 were identified in various brain regions in PE mice. PC1 showed preventive effects by preventing the alteration of PROKs system in some brain regions.
In conclusion, the present doctoral research represents the pioneering investigation of the upregulation of PROK2 levels in the context of preeclampsia. Furthermore, the study investigated the effect of PROKs on the disruption of BBB integrity by increasing its permeability. In addition, the study revealed the altered expression of the PROK system in different maternal brain regions during preeclampsia. Notably, the study elucidated the therapeutic potential of PROK receptor antagonists in ameliorating hypertension, preventing BBB disruption, mitigating inflammation and injury, and counteracting selected alterations within the brain PROK system that occur during preeclampsia. Together, these findings highlight the potential of the PROK system as a viable therapeutic target for the treatment of preeclampsia and associated cerebrovascular complications.

Keywords:
Prokineticin, Preeclampsia, Brain, Prokineticin receptor antagonist, Blood- brain barrier dysfunction, Vascular dementia