Browsing by Author "Pfarrer, Christiane D."
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Item Expression of matrix metalloproteinase (MMP)-2, MMP-14 and tissue inhibitor of matrix metalloproteinase (TIMP)-2 during bovine placentation and at term with or without placental retention(Elsevier, 2011-04-01) Dilly, Marc; Hambruch, Nina; Shenavai, Sima; Schüler, Gerhard; Froehlich, R.; Häeger, Jan Dirk; Pfarrer, Christiane D.; Özalp, Gözde Rabia; Uludağ Üniversitesi/Veterinerlik Fakültesi/Kadın Hastalıkları ve Doğum Anabilim Dalı.; 0000-0003-4694-6937; AAE-3607-2019; 23985710500Matrix metalloproteinases (MMPs) and counteracting tissue inhibitors of metalloproteinases (TIMPs) are balancing extracellular matrix (ECM) formation and degradation. The latter is believed to be an important aspect for the detachment of fetal membranes postpartum when loosening the feto-matemal connection which is a prerequisite to avoid placental retention a common disease in cows leading to considerable economic loss. Membrane-type (MT) MMPs have been suggested as potential activators controlling ECM remodelling. In particular, MT1-MMP (MMP-14) is able to degrade ECM substrates and activate MMP-2 through binding TIMP-2 at the cell surface. Since the connection between the trophoblast and the maternal caruncular epithelium is supported by integrin receptors bound to ECM, we hypothesize that impaired modulation of the ECM by TIMPs/MMPs participates in the aetiology of bovine retained fetal membranes. To analyse this involvement, placentomes were collected from cows after term parturition and timely release of fetal membranes (n = 4) and cows with retained fetal membranes after various treatments for the induction of parturition using progesterone antagonist (aglepristone), PGF(2 alpha) analogue, glucocorticoid, and after elective caesarean sections (each group n = 3). The expression of MMP-14, MMP-2 and of TEMP-2 was examined by real-time-PCR, irnmunohistochemistry, Western blot and zymography. The relative mRNA expression levels of MMP-14 remained unchanged, while the expression levels of TIMP-2 and MMP-2 partly increased in animals with induced parturition and retention of fetal membranes compared to animals without placental retention. MMP-14 protein was expressed in cells of the uninucleated trophoblast, the fetal mesenchyme and maternal stoma. TIMP-2 was present exclusively in trophoblast giant cells, while MMP-2 could be detected in uninucleated trophoblast cells and the fetal mesenchyme. The presence of the activated enzyme was confirmed by zymography. In conclusion, MMP-14, MMP-2 and TIMP-2 are co-localized in the fetal compartment and therefore could influence the timely release of fetal membranes in cattle.Item Use of the progesterone (P4) receptor antagonist aglepristone to characterize the role of P4 withdrawal for parturition and placental release in cows(Bioscientifica, 2010-10) Shenavai, Sima; Hoffmann, Bernd; Dilly, Marc; Pfarrer, Christiane D.; Schüler, Gerhard; Özalp, Gözde Rabia; Çalışkan, Çağlar; Seyrek İntaş, Kamil; Uludağ Üniversitesi/Veterinerlik Fakültesi/Doğum ve Jinekoloji Bölümü.; 0000-0003-4694-6937; AAH-7292-2019; AAE-3607-2019; 23985710500; 23984353800; 6603409870In late pregnant cows, progesterone (P-4) is mainly of luteal origin. However, the trophoblast may provide high local P-4 concentrations in the uterus. To test for the importance of a complete P-4 withdrawal for parturition-related processes and placental release, the P-4 receptor (PGR) blocker aglepristone (Ap) was administered to three cows on days 270 and 271 of pregnancy. A complete opening of the cervix was observed 46.5 +/- 7.3 h after the start of treatment. However, expulsion of the calves was impaired obviously because of insufficient myometrial activity, and placental membranes were retained for at least 10 days. Measurement of P-4 concentrations indicated that PGR blockage induced luteolysis. To investigate the role of P-4 withdrawal for the prepartal tissue remodeling of the placentomes, the caruncular epithelium was evaluated by morphometry, and the percentage of trophoblast giant cells (TGCs) relative to the total number of trophoblast cells were assessed. Caruncular epithelium in Ap-treated cows (D272 + Ap) was immature (30.5 +/- 3.3%) and not different from untreated controls (elected cesarean section (CS) on day 272; D272-CS; 31.5 +/- 1.4%), whereas it was significantly reduced at normal term (D280.5 +/- 1.3; 21.0 +/- 6.1%; P=0.011). Correspondingly, the percentage of TGCs were 20.1 +/- 1.4 in D272 + Ap, 22.1 +/- 4.8 in D272-CS, and 9.8 +/- 3.9 at term (P=0.001). No effect was detected on placental estrogen synthesis. The results showed that in late pregnant cows, P-4 withdrawal only induces a limited spectrum of the processes related to normal parturition and is not a crucial factor for the prepartal tissue remodeling in placentomes and the timely release of the placenta.