@article{JueppnerMubeenLeisseetal.2017,
  author    = {J{\"u}ppner, Jessica and Mubeen, Umarah and Leisse, Andrea and Caldana, Camila and Brust, Henrike and Steup, Martin and Herrmann, Marion and Steinhauser, Dirk and Giavalisco, Patrick},
  title     = {Dynamics of lipids and metabolites during the cell cycle of Chlamydomonas reinhardtii},
  series = {The plant journal},
  volume    = {92},
  journal   = {The plant journal},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {0960-7412},
  doi       = {10.1111/tpj.13642},
  pages     = {331 -- 343},
  year      = {2017},
  abstract  = {Metabolites and lipids are the final products of enzymatic processes, distinguishing the different cellular functions and activities of single cells or whole tissues. Understanding these cellular functions within a well-established model system requires a systemic collection of molecular and physiological information. In the current report, the green alga Chlamydomonas reinhardtii was selected to establish a comprehensive workflow for the detailed multi-omics analysis of a synchronously growing cell culture system. After implementation and benchmarking of the synchronous cell culture, a two-phase extraction method was adopted for the analysis of proteins, lipids, metabolites and starch from a single sample aliquot of as little as 10-15million Chlamydomonas cells. In a proof of concept study, primary metabolites and lipids were sampled throughout the diurnal cell cycle. The results of these time-resolved measurements showed that single compounds were not only coordinated with each other in different pathways, but that these complex metabolic signatures have the potential to be used as biomarkers of various cellular processes. Taken together, the developed workflow, including the synchronized growth of the photoautotrophic cell culture, in combination with comprehensive extraction methods and detailed metabolic phenotyping has the potential for use in in-depth analysis of complex cellular processes, providing essential information for the understanding of complex biological systems.},
  language  = {en}
}
@article{KehmJaehnertDeubeletal.2020,
  author    = {Kehm, Richard and J{\"a}hnert, Markus and Deubel, Stefanie and Flore, Tanina and K{\"o}nig, Jeannette and Jung, Tobias and Stadion, Mandy and Jonas, Wenke and Sch{\"u}rmann, Annette and Grune, Tilman and H{\"o}hn, Annika},
  title     = {Redox homeostasis and cell cycle activation mediate beta-cell mass expansion in aged, diabetes-prone mice under metabolic stress conditions: role of thioredoxin-interacting protein (TXNIP)},
  series = {Redox Biology},
  volume    = {37},
  journal   = {Redox Biology},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {2213-2317},
  doi       = {10.1016/j.redox.2020.101748},
  pages     = {11},
  year      = {2020},
  abstract  = {Overnutrition contributes to insulin resistance, obesity and metabolic stress, initiating a loss of functional beta-cells and diabetes development. Whether these damaging effects are amplified in advanced age is barely investigated. Therefore, New Zealand Obese (NZO) mice, a well-established model for the investigation of human obesity-associated type 2 diabetes, were fed a metabolically challenging diet with a high-fat, carbohydrate restricted period followed by a carbohydrate intervention in young as well as advanced age. Interestingly, while young NZO mice developed massive hyperglycemia in response to carbohydrate feeding, leading to beta-cell dysfunction and cell death, aged counterparts compensated the increased insulin demand by persistent beta-cell function and beta-cell mass expansion. Beta-cell loss in young NZO islets was linked to increased expression of thioredoxin-interacting protein (TXNIP), presumably initiating an apoptosis-signaling cascade via caspase-3 activation. In contrast, islets of aged NZOs exhibited a sustained redox balance without changes in TXNIP expression, associated with higher proliferative potential by cell cycle activation. These findings support the relevance of a maintained proliferative potential and redox homeostasis for preserving islet functionality under metabolic stress, with the peculiarity that this adaptive response emerged with advanced age in diabetesprone NZO mice.},
  language  = {en}
}
@article{LinkeWoesleHarder2020,
  author    = {Linke, Christian and W{\"o}sle, Markus and Harder, Anja},
  title     = {Anti-cancer agent 3-bromopyruvate reduces growth of MPNST and inhibits metabolic pathways in a representative in-vitro model},
  series = {BMC cancer},
  volume    = {20},
  journal   = {BMC cancer},
  number    = {1},
  publisher = {BioMed Central},
  address   = {London},
  issn      = {1471-2407},
  doi       = {10.1186/s12885-020-07397-w},
  pages     = {11},
  year      = {2020},
  abstract  = {Background Anticancer compound 3-bromopyruvate (3-BrPA) suppresses cancer cell growth via targeting glycolytic and mitochondrial metabolism. The malignant peripheral nerve sheath tumor (MPNST), a very aggressive, therapy resistant, and Neurofibromatosis type 1 associated neoplasia, shows a high metabolic activity and affected patients may therefore benefit from 3-BrPA treatment. To elucidate the specific mode of action, we used a controlled cell model overexpressing proteasome activator (PA) 28, subsequently leading to p53 inactivation and oncogenic transformation and therefore reproducing an important pathway in MPNST and overall tumor pathogenesis. Methods Viability of MPNST cell lines S462, NSF1, and T265 in response to increasing doses (0-120 mu M) of 3-BrPA was analyzed by CellTiter-Blue (R) assay. Additionally, we investigated viability, reactive oxygen species (ROS) production (dihydroethidium assay), nicotinamide adenine dinucleotide dehydrogenase activity (NADH-TR assay) and lactate production (lactate assay) in mouse B8 fibroblasts overexpressing PA28 in response to 3-BrPA application. For all experiments normal and nutrient deficient conditions were tested. MPNST cell lines were furthermore characterized immunohistochemically for Ki67, p53, bcl2, bcl6, cyclin D1, and p21. Results MPNST significantly responded dose dependent to 3-BrPA application, whereby S462 cells were most responsive. Human control cells showed a reduced sensitivity. In PA28 overexpressing cancer cell model 3-BrPA application harmed mitochondrial NADH dehydrogenase activity mildly and significantly failed to inhibit lactate production. PA28 overexpression was associated with a functional glycolysis as well as a partial resistance to stress provoked by nutrient deprivation. 3-BrPA treatment was not associated with an increase of ROS. Starvation sensitized MPNST to treatment. Conclusions Aggressive MPNST cells are sensitive to 3-BrPA therapy in-vitro with and without starvation. In a PA28 overexpression cancer cell model leading to p53 inactivation, thereby reflecting a key molecular feature in human NF1 associated MPNST, known functions of 3-BrPA to block mitochondrial activity and glycolysis were reproduced, however oncogenic cells displayed a partial resistance. To conclude, 3-BrPA was sufficient to reduce NF1 associated MPNST viability potentially due inhibition of glycolysis which should lead to the initiation of further studies and promises a potential benefit for NF1 patients.},
  language  = {en}
}
@phdthesis{Skirycz2007,
  author    = {Skirycz, Aleksandra},
  title     = {Functional analysis of selected DOF transcription factors in the model plant Arabidopsis thaliana},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16987},
  school      = {Universit{\"a}t Potsdam},
  year      = {2007},
  abstract  = {Transcription factors (TFs) are global regulators of gene expression playing essential roles in almost all biological processes, and are therefore of great scientific and biotechnological interest. This project focused on functional characterisation of three DNA-binding-with-one-zinc-finger (DOF) TFs from the genetic model plant Arabidopsis thaliana, namely OBP1, OBP2 and AtDOF4;2. These genes were selected due to severe growth phenotypes conferred upon their constitutive over-expression. To identify biological processes regulated by OBP1, OBP2 and AtDOF4;2 in detail molecular and physiological characterization of transgenic plants with modified levels of OBP1, OBP2 and AtDOF4;2 expression (constitutive and inducible over-expression, RNAi) was performed using both targeted and profiling technologies. Additionally expression patterns of studied TFs and their target genes were analyzed using promoter-GUS lines and publicly available microarray data. Finally selected target genes were confirmed by chromatin immuno-precipitation and electrophoretic-mobility shift assays. This combinatorial approach revealed distinct biological functions of OBP1, OBP2 and AtDOF4;2. Specifically OBP2 controls indole glucosinolate / auxin homeostasis by directly regulating the enzyme at the branch of these pathways; CYP83B1 (Skirycz et al., 2006). Glucosinolates are secondary compounds important for defence against herbivores and pathogens in the plants order Caparales (e.g. Arabidopsis, canola and broccoli) whilst auxin is an essential plant hormone. Hence OBP2 is important for both response to biotic stress and plant growth. Similarly to OBP2 also AtDOF4;2 is involved in the regulation of plant secondary metabolism and affects production of various phenylpropanoid compounds in a tissue and environmental specific manner. It was found that under certain stress conditions AtDOF4;2 negatively regulates flavonoid biosynthetic genes whilst in certain tissues it activates hydroxycinnamic acid production. It was hypothesized that this dual function is most likely related to specific interactions with other proteins; perhaps other TFs (Skirycz et al., 2007). Finally OBP1 regulates both cell proliferation and cell expansion. It was shown that OBP1 controls cell cycle activity by directly targeting the expression of core cell cycle genes (CYCD3;3 and KRP7), other TFs and components of the replication machinery. Evidence for OBP1 mediated activation of cell cycle during embryogenesis and germination will be presented. Additionally and independently on its effects on cell proliferation OBP1 negatively affects cell expansion via reduced expression of cell wall loosening enzymes. Summing up this work provides an important input into our knowledge on DOF TFs function. Future work will concentrate on establishing exact regulatory networks of OBP1, OBP2 and AtDOF4;2 and their possible biotechnological applications.},
  language  = {en}
}