This thesis will be organized into two chapters discussing the placental expression of two proteins, pyruvate kinase M2 (PKM2) and heat shock protein 27 (HSP 27), in human placentas. Understanding the mechanisms of placental metabolism in healthy and diseased placentas helps us understand how placenta disorders occur and how we can treat these disorders. The goal is to investigate these proteins to gain an understanding of their roles in placental disorders and help decrease maternal and fetal mortality rates. Chapter one covers the background of pyruvate kinase M2 (PKM2) in cancer and embryonic tissues, and the expression of PKM2 in the human placenta. Cancer PKM2 has been studied extensively, but little is know about the role of placental PKM2. Expression of PKM2 is confirmed in normal human placenta samples and described in preeclamptic and intrauterine growth restriction (IUGR) affected human placentas. Proteins associated with elevated PKM2 in cancer are also associated with elevated PKM2 in human placentas. Comparing normal and diseased placenta samples helps understand the similarities between cancer PKM2 and placental PKM2. Understanding the mechanisms of placental metabolism and PKM2 expression in the human placenta will clarify how the placenta is affected by preeclampsia and IUGR and the role placental PKM2 plays in each of these diseases. Chapter two will cover a paper that I wrote on the expression of phosphorylated heat shock protein 27 (HSP27) in the human placenta. Heat shock proteins are involved in the stress response and help inhibit apoptosis. The object of the study was to look for correlations between p-HSP27 and apoptosis in human and ovine placenta samples. P-HSP27 was quantified in human placenta samples and in placenta sampled collected from ovine models. Pregnant control and hyperthermic sheep models were used to quantify expression of p-HSP27 across gestation. This study showed similarities between human IUGR and our ovine IUGR model, suggesting a link between decreased p-HSP27 and increased apoptosis in IUGR.

Präeklampsie (PE) ist eine Komplikation, die während der Schwangerschaft auftritt, fast 2-8% aller Schwangerschaften betrifft und human spezifisch ist. PE ist eine der Hauptursachen für den Tod von Mutter und Kind. Eine abnormale Plazentaentwicklung aufgrund einer verminderten Trophoblasteninvasion und einem gestörten Umbau der Spiralarterien trägt zur Pathogenese der PE bei. Klinisch wird die PE durch Bluthochdruck und Proteinurie, auftretendnach der 20. Schwangerschaftswoche, diagnostiziert und kann durch eine Funktionsstörung von Organen begleitet werden. Bei besonders schweren Verläufen ist die frühzeitige Endbindung die letzte Möglichkeit das Überleben der Mutter zu gewährleisten. Das Ziel dieser Studie ist es, weitere Gene zu identifizieren, die durch ERVs in der menschlichen Plazenta spezifisch reguliert werden und in PE dysreguliert sind. Um dieses Ziel zu erreichen, wurde das Transkriptom von primären menschlichen Trophoblastenzellen von 5 gesunden und 5 früh einsetzenden PE-Plazenten mittels RNA-Sequenzierung analysiert. Es wurden 335 Gene identifiziert, welche eine höhere Expression in den Trophoblastenzellen im Vergleich zu anderen Geweben aufwiesen. Zusätzlich zeigten einige der Gene (n=88) eine Co-Regulation der Expression durch retrovirale LTRs (10-kb 5‘ des transcription start side (TSS) des Gens). Hauptinteresse lag hierbei auf den Genen, welche ebenfalls eine Dysregulation in der PE aufwiesen (n = 16). Diese Studie identifizierte EPS8L1, das durch primaten-spezifisches ERV-LTR (MLT1G1) in Trophoblastenzellen reguliert wird, als einen wichtigen Faktor in der Entwicklung der menschlichen Plazenta. EPS8L1 ist in der PE Plazenta dysreguliert und involviert in mehrere Signalwege und die Funktionalität von Trophoblasten wie Invasion, Angiogenese und Redoxhomöostase. Hierdurch führt diese Arbeit zu einem besseren Verständnis der PE und deren human-spezifischer Natur. / Preeclampsia (PE) is a complication that occurs during pregnancy and affects almost 2-8% of all pregnancies and is often regarded as a human-specific disorder.1,2 PE is one of the major causes of maternal and fetal death.1 Failure of the trophoblast cells to invade into the maternal decidua results in the improper remodeling of spiral arteries leading to PE pathogenesis. Clinically, it is diagnosed as a maternal syndrome, diagnosed by the new-onset of hypertension and proteinuria or other end-organ dysfunction after the 20th week of pregnancy. So far, the only effective treatment of the disorder is the removal of the placenta tissue and delivery of the infant. The aim of this study is to identify additional genes that are regulated by the human ERV-LTRs in the human placenta specifically, and are dysregulated in PE. To achieve this aim, the transcriptome of primary human trophoblast cells of 5 healthy and 5 early-onset PE placentas were analyzed by RNA sequencing (RNA-seq). RNA-seq analysis identified genes (n=335) with stronger expression in the trophoblast cells as compared to other human body tissues. Additionally, some of the genes (n=88) showed co-regulation of expression by the human ERV-LTRs in their vicinity (10-kb upstream of transcription start side (TSS) of the gene). Since my interest was to identify the new targets of PE pathogenesis, so I focused on genes (n=16) with dysregulated expression in women presented with PE. This study identified a new gene EPS8L1, regulated by primate-specific ERV-LTR in trophoblast cells that has a predominant role in the human placenta development and demonstrated that its dysregulation affected multiple pathways involved in trophoblast function like invasion, angiogenesis and maintenance of cell redox homeostasis. Furthermore, this study leads to the better understanding of the disease by explaining certain aspects of human-specific nature of PE.