@phdthesis{JanakiRaman2023, author = {Janaki Raman, Sudha Rani}, title = {Analysis of the molecular mechanisms underlying the role of SREBP1 in Glioblastoma tumour development and progression}, doi = {10.25972/OPUS-28024}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-280245}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {Glioblastoma (GB) is the most aggressive malignant adult brain tumour with a median survival rate of only 15 months. GB tumours are characterized by necrotic and hypoxic core, which leads to nutrient deficient areas contributing to invasive, diffuseinfiltrative and angiogenic nature of these tumours. Cells exposed to nutrient deficient conditions and are known to reprogram their metabolism to produce or procure macro molecules from their environment. This makes cancer cells uniquely dependent on transcriptional regulators and a window of opportunity to target them. Sterol regulatory element binding protein 1 (SREBP1) is a transcriptional regulator of de-novo fatty acid synthesis in cells. The aim of this thesis was to investigate if SREBP1 was involved in restructuring the transcriptional regulation of genes involved in fatty acid biosynthesis upon low serum condition, in mediating interaction with other cell types in the tumour bulk such as endothelial cells, in regulating cancer stem like cells and finally to study its upstream regulation in GB. Global transcriptional analysis on GB cells exposed to low serum conditions revealed that SREBP1 regulated several fatty acid biosynthesis and phospholipid metabolic processes. PLA2G3 was identified as a novel target of SREBP1 in GB that was uniquely regulated in low serum condition. Analysis of total fatty acid and lipid species revealed that loss of SREBP1 in low serum condition changes the proportion of saturated, MUFAs and PUFAs. These changes were not specific to loss of PLA2G3 but as a result of downregulation of many genes regulated by SREBP1 in the fatty acid biosynthetic pathway. Next, treatment of HUVEC's (endothelial cells) with condition medium from SREBP1-silenced U87 cells inhibited sprouting and tube formation capacity compared to the control condition, emphasizing the role of SREBP1 in angiogenesis and release of signalling mediators. Further, SREBP1 was shown to be important for proliferation of patient derived stem like cells and becomes indispensable for forming neurospheres in long term cultures, indicating its role in maintaining stemness. Also, inhibition of SREBP function by blocking the esterification of cholesterol using inhibitors targeting SOAT1 showed impairment in the viability of GB cells exposed to serum-depleted condition. Overall, SREBP1 plays an important role in maintaining tumour growth in nutrient deficient conditions and help in interaction with tumour microenvironment contributing to the aggressiveness of this tumour and poses itself as an attractive and unique target for GB treatment}, language = {en} } @article{BannaschBergerSchwartkoppetal.2021, author = {Bannasch, Johannes H. and Berger, Benjamin and Schwartkopp, Claus-Peter and Berning, Marco and Goetze, Oliver and Panning, Marcus and Fritz-Weltin, Miriam and Trendelenburg, George and Gelderblom, Mathias and L{\"u}tgehetmann, Marc and Stute, Fridrike and Horvatits, Thomas and Dirks, Meike and Antoni, Christoph and Behrendt, Patrick and Pischke, Sven}, title = {HEV-associated neuralgic amyotrophy: a multicentric case series}, series = {Pathogens}, volume = {10}, journal = {Pathogens}, number = {6}, issn = {2076-0817}, doi = {10.3390/pathogens10060672}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-239691}, year = {2021}, abstract = {Background: Neuralgic amyotrophy (NA) has been described as a possible extrahepatic manifestation of hepatitis E virus (HEV) infection. Usually, HEV-associated NA occurs bilaterally. The clinical characteristics determining the course of HEV-associated NA have still not been defined. Methods: In this retrospective multicentric case series, 16 patients with HEV-associated NA were studied and compared to 176 HEV patients without NA in terms of their age, sex, and ALT levels. Results: Neither gender distribution (75\% vs. 67\% male) nor age (47 vs. 48 years median) differed significantly between the NA patients and controls. Eight NA patients (50\%) presented with bilateral involvement — seven of these had right-side dominance and one had left-side dominance. Thirteen cases (81\%) were hospitalized. Eight of these patients stayed in hospital for five to seven days, and five patients stayed for up to two weeks. The time from the onset of NA to the HEV diagnosis, as well as the diagnostic and therapeutic proceedings, showed a large variability. In total, 13 (81\%) patients received treatment: 1/13 (8\%) received intravenous immunoglobulins, 8/13 (62\%) received glucocorticoids, 3/13 (23\%) received ribavirin, and 6/13 (46\%) received pregabalin/gabapentin. Patients with ages above the median (47 years) were more likely to be treated (p = 0.001). Conclusion: HEV-associated NA causes a relevant morbidity. In our case series neither the type of treatment nor the time of initiation of therapy had a significant effect on the duration of hospitalization or the course of the disease. The clinical presentation, the common diagnostic and therapeutic procedures, and the patients' characteristics showed large variability, demonstrating the necessity of standardized protocols for this rare but relevant disease.}, language = {en} }