title: Evaluation of circulating miRNAs during late pregnancy in the mare.
abstract: MicroRNAs (miRNAs) are small, non-coding RNAs which are produced throughout the body. Individual tissues tend to have a specific expression profile and excrete many of these miRNAs into circulation. These circulating miRNAs may be diagnostically valuable biomarkers for assessing the presence of disease while minimizing invasive testing. In women, numerous circulating miRNAs have been identified which change significantly during pregnancy-related complications (e.g. chorioamnionitis, eclampsia, recurrent pregnancy loss); however, no prior work has been done in this area in the horse. To identify pregnancy-specific miRNAs, we collected serial whole blood samples in pregnant mares at 8, 9, 10 m of gestation and post-partum, as well as from non-pregnant (diestrous) mares. In total, we evaluated a panel of 178 miRNAs using qPCR, eventually identifying five miRNAs of interest. One miRNA (miR-374b) was differentially regulated through late gestation and four miRNAs (miR-454, miR-133b, miR-486-5p and miR-204b) were differentially regulated between the pregnant and non-pregnant samples. We were able to identify putative targets for the differentially regulated miRNAs using two separate target prediction programs, miRDB and Ingenuity Pathway Analysis. The targets for the miRNAs differentially regulated during pregnancy were predicted to be involved in signaling pathways such as the STAT3 pathway and PI3/AKT signaling pathway, as well as more endocrine-based pathways, including the GnRH, prolactin and insulin signaling pathways. In summary, this study provides novel information about the changes occurring in circulating miRNAs during normal pregnancy, as well as attempting to predict the biological effects induced by these miRNAs.
authors.affiliation: Department of Veterinary Science, University of Kentucky, Lexington, KY, United States of America.
authors.forename: Shavahn C
authors.identifier: http://orcid.org/0000-0001-5193-6675
authors.initials: SC
authors.lastname: Loux
authors.affiliation: Department of Veterinary Science, University of Kentucky, Lexington, KY, United States of America.
authors.forename: Kirsten E
authors.initials: KE
authors.lastname: Scoggin
authors.affiliation: Department of Animal Sciences, Colorado State University, Fort Collins, CO, United States of America.
authors.forename: Jason E
authors.initials: JE
authors.lastname: Bruemmer
authors.affiliation: Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Urbana, IL, United States of America.
authors.forename: Igor F
authors.initials: IF
authors.lastname: Canisso
authors.affiliation: Department of Veterinary Science, University of Kentucky, Lexington, KY, United States of America.
authors.forename: Mats H T
authors.initials: MH
authors.lastname: Troedsson
authors.affiliation: Department of Veterinary Science, University of Kentucky, Lexington, KY, United States of America.
authors.forename: Edward L
authors.initials: EL
authors.lastname: Squires
authors.affiliation: Department of Veterinary Science, University of Kentucky, Lexington, KY, United States of America.
authors.forename: Barry A
authors.identifier: http://orcid.org/0000-0002-0502-0276
authors.initials: BA
authors.lastname: Ball
mesh_terms: D000818:Animals; D005260:Female; D006736:Horses; D035683:MicroRNAs / Q000097:blood*; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000097:blood*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D035683:MicroRNAs