Dr Vanessa Heron1,2,3, MARINA KATERELOS1, LESLEY CHENG4, ROBYN SHARPLES4, PETER MOUNT1,3, SUET-WAN CHOY1,2, JOHN WHITLAM1,3, ASPASIA PEFANIS1,3, PO YEE MIA LEUNG1,3, KATHY PAIZIS1,2,3
1Department of Nephrology, Austin Health, Heidelberg, Australia, 2Department of Obstetrics, Mercy Hospital for Women, Heidelberg, Australia, 3Department of Medicine, University of Melbourne, Parkville, Australia, 4La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Australia
Biography:
Dr Vanessa Heron is a Nephrologist and Obstetric Medicine Physician at Austin Health. She graduated with honours from Monash University in 2013 and received her fellowship with the Royal Australasian College of Physicians in 2020. After completing advanced training in nephrology, Vanessa completed specialist training in obstetric medicine at Mercy Hospital for Women. She is currently pursuing a PhD at the University of Melbourne, researching molecular changes in the urine of women with pre-eclampsia, supported by a Jacquot Research Entry Scholarship.
Aim:
To identify molecular changes in urine of women with pre-eclampsia (PE).
Background:
PE affects 3% of pregnancies. Better understanding of PE pathogenesis will improve identification of risk, allow earlier diagnosis and help find targeted treatments. Molecular analysis of urinary exosomes (RNA and protein) and urinary kidney specific cell-free DNA (ks-cfDNA) provides information on kidney health and PE pathophysiology.
Methods:
Participants with PE were gestation-matched to normotensive pregnant participants (NP). A total of 60, 52 and 40 participants were included in the RNA, protein and ks-cfDNA studies respectively. Exosomes were isolated using differential ultracentrifugation. RNA was extracted and sequenced to determine differential expression. Western Blot evaluated protein expression of necroptotic markers. Ks-cfDNA was analysed with digital PCR.
Results:
Exosomal RNA sequencing found increased expression of five miRNAs (miR-1-3p, miR-95-3p, miR-143-3p, miR-199a-3p, miR-513a-3p) and reduced expression of miR-203a-3p in PE compared to NP. Protein analysis of the necroptosis pathway found 30% of PE participants expressed phosphorylated mixed lineage domain-like pseudokinase (pMLKL) compared to zero NP participants (p=0.003). Finally, analysis of ks-cfDNA showed increase in absolute quantities of two of three ks-cfDNA markers. Median Chr11 quantity was 231 in PE versus 61.96 copies/mL in NP (p=0.028). Median DDC quantity was 81.06 and 20.28 copies/mL in PE and NP groups respectively (p=0.047). Both markers are found in renal proximal tubular epithelial cells while Chr11 is also seen in podocytes.
Conclusion:
This multi-methods study reveals multiple molecular urinary signals distinguishing women with PE from NP. These changes include a unique miRNA signature, alterations in the pMLKL protein, and increased ks-cfDNA quantities. Molecular analysis of urine is a non-invasive and promising strategy for pathogenic understanding and further study of PE.