Team Leader
Staff
- Dr. med. vet. Elisabeth Engelke
- Dr. med. vet. Julia Hollenbach
- Dr. med. vet. Rüdiger Koch
- Dr. med. vet. Sophia Pankoke
- Ines Blume, VMTA (Veterinary medical technical assistant)
- Marvin Sandmann, Laboratory technician
- Oliver Stünkel, Biology laboratory technician
- Doris Voigtländer, Laboratory technician
- Gudrun Wirth, VMTA
Doctoral Students
- Katharina Böse, Veterinarian
- Annika Köhne, Veterinarian
- Lena Pennemann, Veterinarian
- Joachim Truelsen, Veterinarian
Research
The research group of Prof. Pfarrer focuses on the structure and function of the bovine placenta.
Most of the investigations are carried out using cell culture models. Several established cell lines are available (bovine caruncular epithelial cells, bovine endometrial glandular cells and bovine endometrial fibroblasts), which are used both in mono- and co-cultures in the various research projects. To simulate different metabolic and hormonal situations in living cattle, the cells are stimulated with different substances. These are, for example, growth factors, ketone bodies or hormones. The influence of these substances on the cells is then examined on a functional, structural and molecular biological level. Methods such as light and electron microscopy, life cell imaging, RT-qPCR, immunohistology, immunofluorescence and western blot are used.
Another focus is on the morphology and morphometry of the bovine placenta. For this purpose, bovine placenta samples from different stages of pregnancy are examined using serial block-face scanning electron microscopy (SBF-SEM). Computer software is then used to create a three-dimensional model of selected placental structures. This method makes it possible to gain more precise knowledge of the ultrastructural composition of the bovine placenta.
Current research projects
The influence of a negative energy balance on bovine endometrial cells
After parturition, high-yielding dairy cows often enter a negative energy balance, which is characterized by an increased concentration of ketone bodies in the blood. Since this condition is, among others, associated with poor reproductive performance, this project investigates the influence of the ketone body β-hydroxybutyrate on bovine endometrial cells. First studies have shown that an increased concentration of β-hydroxybutyrate has a negative impact on cell physiological parameters in caruncular epithelial cells, endometrial gland cells and fibroblasts and that there is an increase in inflammatory markers in these cells. In addition, there is an altered expression pattern of steroid hormone receptors in the endometrial gland cells.
The influence of interferon tau on the polarization of bovine endometrial cells during the implantation period
This project is dedicated to the cellular processes that take place during the peri-implantation period in cattle, i.e. around the time of implantation of the embryo. In particular, the importance of the cytokine interferon-tau (IFNτ) - the embryo-specific signal for maternal recognition of pregnancy - and its influence on the polarization of uterine epithelial cells is being investigated. Different cell culture and molecular biological methods (RT-qPCR, Western blot, immunofluorescence) are used to analyse the expression patterns of various polarization markers and their alterations at gene and protein level under the influence of IFNτ and the steroid hormones progesterone and estrogen.
Studies on the expression and function of osteopontin in bovine endometrial cells
Osteopontin is a secretion product of endometrial gland cells and plays an important role in implantation in sheep by mediating contact between the maternal endometrial cells and the trophoblast cells. In this project, the regulation and function of osteopontin during implantation in cattle will be investigated. For this purpose, bovine endometrial gland cells are stimulated with the steroid hormones progesterone and estrogen as well as the cytokine IFNτ in various combinations. Subsequently, the expression patterns of osteopontin are analyzed at gene (RT-qPCR) and protein level (Western blot, immunofluorescence).
The structure of the bovine placenta at the electron microscopic level
This research project deals with the three-dimensional visualization of the ultrastructures in the bovine placenta using electron microscopy. For this purpose, placental samples are taken from fresh bovine placentas at different stages of pregnancy, fixed and embedded in plastic. The samples are then subjected to a 3D scan in an electron microscope and analyzed using computer software. This makes it possible, for example, to create 3D models of selected structures or to analyze trophoblast cells in terms of cell volume. In this way, promising results and new insights into ultrastructural conditions in the bovine placenta have already been achieved. The results obtained so far relate to the three-dimensional representation of the feto-maternal contact surface between the trophoblast and uterine epithelium as well as the interaction between the two.
