E-Poster Presentation ESA-SRB-ANZBMS 2021

An exploratory study for using extracellular vesicle miRNA as a biomarker of fertility status (#603)

Pevindu Abeysinghe 1 , Natalie Turner 1 , Hassendrini Peiris 1 , Kanchan Vaswani 1 , Nick Cameron 2 , Nathanael McGhee 2 , Murray D Mitchell 1 , Jayden Logan 1
  1. Centre for Children’s Health Research, School of Biomedical Sciences, Faculty of Health, The Queensland University of Technology, Brisbane, Queensland, 4029, Australia.
  2. Nindooinbah, 272, Nindooinbah House Road, Beaudesert, 4285

Decline of fertility links to genetic traits. Identification of novel biomarkers has resulted in improvements of fertility treatments. Exosomes (EX) are small extracellular vesicles (EVs) of ~30-150nm diameter which have gained recognition as a prognostic and diagnostic biomarker of several disorders. Exosomes enhance inflammatory mediators in the endometrium and uterus, which can lead to infertility. EX contain, among other biomolecules, micro-RNA (miRNA) which have been validated as biomarkers in various diseases including cancer. MiRNAs have been shown to regulate post-transcriptional modifications and are differentially expressed between divergent groups of fertility.

The present exploratory study aims to evaluate the miRNA profiles of EV and fractionated exosomal samples of high and low tick-resistant beef cattle and their offspring, to explore the potential of miRNA biomarkers of tick resistance. A novel tick scoring system was adopted to classify cows (n = 3/group) into high or low tick resistant groups. Established isolation and enrichment protocols were used to isolate EVs and fractionate EX from the bovine blood plasma. The resultant EX and non-EX samples were processed for next generation miRNA sequencing.

MiR-449a, relates to cellular inflammatory pathways, was highly expressed in maternal high tick-resistant EX samples, in which a total of 2631 miRNAs were identified in fractionated EX and non-EX samples. Of these, 174 novel miRNAs were identified, and 10 were differentially expressed (DE) (FDR < 0.05) (Figure 1). EV samples also contained these 10 DE miRNAs, and three miRNAs were highly expressed: miR-2419-3p, miR-7861-3p and miR-2372-5p. Enrichment analysis shows that these miRNAs alter cellular signalling pathways relate to inflammation. Fractionated samples of offspring contained 196 novel miRNAs, however no miRNA were differentially expressed.

The findings of this exploratory study demonstrate the potential of EV, EX and non-EX miRNA as biomarkers of genetic disorders which can be applied to fertility biomarker studies.  

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Figure 1. Heatmap of differential expression of miRNAs between high and low  tick resistant mother plasma SEC samples (EX and non-EX)