Gene Expression in Pre‐Term, Pre‐Labour and Parturient Canine Placenta

Abstract

Contents Matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs), vascular endothelial growth factor (VEGF)‐A, VEGF‐A receptor (Flt‐1) and KiSS‐1 receptor (KiSS‐1R) all play a role in trophoblast invasion in a number of mammalian species. However, mRNA expression of factors regulating trophoblast invasion has not been studied in dogs. Abnormal expression of these factors at the end of canine gestation may contribute to placental retention and/or subinvolution of placental sites. Therefore, we sought to determine the relative mRNA expression of these factors in canine chorioallantois tissue at 61 ± 1 day past the LH surge (pre‐term; n = 4), following elective c‐section at 64 ± 1 day past the LH surge prior to first‐stage labour (pre‐labour; n = 4) and following natural delivery (parturient; n = 3). Total RNA was isolated, real‐time RT‐PCR was performed, and relative expression was calculated using the relative quantitation (2−ΔΔCT) method. MMP‐9 mRNA expression was significantly higher in pre‐term samples compared to pre‐labour and parturient samples. The results showed no significant difference between MMP‐2, TIMP‐2, VEGF‐A and Flt‐1 mRNA expression among the three groups. KiSS‐1R mRNA was not expressed in any tissues studied. Gene expression of MMP‐9 may be related to the onset of labour, whereas MMP‐2, VEGF‐A, Flt‐1, TIMP‐2 and KiSS‐1R mRNA do not appear to play a role at the end of gestation in the dog.

The Role of Kisspeptin in the Pathogenesis of Pregnancy Complications: A Narrative Review

“…The first evidence confirming the role of kisspeptin-54 in the regulation of invasion processes by MMPs, a family of Zn- and Ca 2+ —dependent endopeptidases, has been presented by Yoshioka et al on the in vitro model of renal carcinoma cells [ 92 ]. This observation has been confirmed by other studies, which strongly indicated that kisspeptin decreased trophoblast cells’ invasion by attenuation of MMPs expression dose-dependent [ 9 , 28 , 93 ]. Francis et al demonstrated that kisspeptin-10 treatment reduced the expression of MMP-2 in the primary trophoblast cells and subsequently disturbed their migratory capability [ 46 ].…”

Canine Endotheliochorial Placenta: Morpho-Functional Aspects

“…An overview of the current knowledge regarding the distribution and gestational expression patterns of some of the extracellular matrix related factors in the dog can be found under [11,26,51,52]. The canine trophoblast has an invasive character.…”

“…invasion) into maternal structures does not stop, and strong invasion of the trophoblast at the bottom of the placental labyrinth is observed until term. Interestingly, whereas major matrix metalloproteinases (MMP2 and -9) are expressed in fetal trophoblast cells [51,52], their inhibitors, in particular TIMP2, are expressed in both counterparts of the placenta (i.e. in the placenta materna and placenta fetalis) [26], including the fetal trophoblast, implying a possible self-regulatory feedback loop protecting the maternal compartments from excessive trophoblast invasion [26].…”