Oral Presentation ESA-SRB-ANZOS 2025 in conjunction with ENSA

Higher mRNA Levels of Endometrial Renin-Angiotensin System Signalling Initiators Suggest a Role in Endometrial Repair (128364)

Tess L Symington 1 2 , Joshua J Fisher 3 4 , Paul Tooney 1 5 , Wei Zhou 6 7 , Evdokia Dimitriadis 6 7 , Eugenie R Lumbers 1 2 , Kirsty G Pringle 1 2
  1. School of Biomedical Science and Pharmacy, University of Newcastle, Newcastle, NSW, Australia
  2. Womens Health Research Program, Hunter Medical Research Institute, Newcastle, Australia
  3. School of Medicine and Public Health, University of Newcastle, Newcastle, NSW, Australia
  4. Mothers and Babies Research Program, Hunter Medical Research Institute, Newcastle, NSW, Australia
  5. Drug Repurposing and Medicines Research Program, Hunter Medical Research Institute, Newcastle, Australia
  6. Department of Obstetrics and Gynaecology, University of Melbourne, Parkville, Victoria , Australia
  7. Gynaecology Research Centre, Royal Women's Hospital, Parkville, Victoria, Australia

The endometrium is shed and remodelled each menstrual cycle in response to hormonal fluctuations. A system known to be under hormonal control and to drive proliferation and differentiation in tissues is the renin-angiotensin system. Currently, the role of the renin-angiotensin system in endometrial remodelling is unknown. This study aimed to characterise the expression of prorenin, the (pro)renin receptor and angiotensinogen, initiators of renin-angiotensin system signalling, across the menstrual cycle to provide insight into their role.

 

Endometrial tissue was collected from fertile patients undergoing endometrial biopsies during the proliferative (n=9), mid (n=10) and late (n=10) secretory phases. Prorenin, (pro)renin receptor and angiotensinogen mRNA expressions were determined by qPCR. Proteins were localised by immunohistochemistry and staining intensity (H-score) quantified using HALO image analysis software.

 

There were no significant changes in mRNA levels of prorenin across the menstrual cycle, with only 3/10 patients in the mid-secretory phase, and 5/10 patients in other phases having detectable prorenin mRNA levels. (Pro)renin receptor mRNA levels were found to be significantly higher in the proliferative phase than the late secretory phase (p<0.05), with 8/10 patients having detectable levels in the proliferative and mid-secretory phase, and 5/10 in the late secretory phase. Angiotensinogen mRNA levels were highest in the proliferative phase compared to the mid and late secretory phases (p=0.0076 and p=0.045, respectively). Seven of 9 patients had detectable angiotensinogen mRNA in the proliferative phase, 5/10 in the mid secretory and 3/10 in the late secretory. There were no significant changes to protein staining intensity across cell types or overall staining intensity within the endometrium.

 

The high levels of mRNA expression of the (pro)renin receptor and angiotensinogen in the proliferative phase of the endometrial cycle suggest that the renin-angiotensin system is working to drive proliferation to promote endometrial tissue regeneration.