title: Dynamics of activities of matrix metalloproteinases-9 and -2, and the tissue inhibitors of MMPs in fetal fluid compartments during gestation and at parturition in the mare.
abstract: During late gestation in the mare, rapid fetal growth is accompanied by considerable placental growth and further invasion of the endometrium by microvilli. This growth requires extensive remodeling of the extracellular matrix (ECM). In early pregnancy, we know that matrix metalloproteinase (MMP)-9 and -2 are involved in the endometrial invasion during endometrial cup formation. The present study investigated whether MMPs are found in fetal fluids later in gestation and during parturition, and if there was a difference in their activities between normal and preterm delivery. Amniotic fluids were collected from pony mares during the latter half of gestation, and amniotic and allantoic fluids from pony and thoroughbred mares at foaling. The fluids were analysed for the activity of MMP-9 and -2, and TIMPs using zymography techniques. There was an increase (P = 0.002) in activity of latent MMP-9 when approaching normal foaling, and a decrease (P < 0.001) during foaling. MMP-2 activity did not change through gestation, or during foaling. When comparing samples from pregnancies resulting in preterm deliveries with samples from foaling mares, the activity of MMP-9 was lower (P < 0.001) and MMP-2 activity was higher (P = 0.004) during foaling than preceding preterm delivery. The activity of MMP-9 was lower (P = 0.002) prior to preterm delivery than before delivery of a live foal at term, whereas no difference (P = 0.07) was demonstrated for latent MMP-2 activity when comparing the same groups. The activity of TIMP-2 was higher (P < 0.001) in the pre-parturient period before normal foaling than preceding preterm delivery. These results suggest that MMPs may have a role as markers for high risk pregnancy in the mare.
authors.affiliation: Division of Veterinary Clinical Studies, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush Veterinary Centre, Easter Bush, Midlothian, EH25 9RG, UK.
authors.forename: Charlotta
authors.initials: C
authors.lastname: Oddsdóttir
authors.forename: Simon C
authors.initials: SC
authors.lastname: Riley
authors.forename: Rosemary
authors.initials: R
authors.lastname: Leask
authors.forename: Darren J
authors.initials: DJ
authors.lastname: Shaw
authors.forename: Christine
authors.initials: C
authors.lastname: Aurich
authors.forename: Franziska
authors.initials: F
authors.lastname: Palm
authors.forename: Abigail L
authors.initials: AL
authors.lastname: Fowden
authors.forename: Sidney W
authors.initials: SW
authors.lastname: Ricketts
authors.forename: Elaine D
authors.initials: ED
authors.lastname: Watson
mesh_terms: D000653:Amniotic Fluid / Q000378:metabolism*; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D005260:Female; D006736:Horses; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D036801:Parturition / Q000378:metabolism*; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000378:metabolism*; D019714:Tissue Inhibitor of Metalloproteinases / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D019714:Tissue Inhibitor of Metalloproteinases; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9