@article{ScognamiglioCabezasWallscheidThieretal.2016,
  author    = {Scognamiglio, Roberta and Cabezas-Wallscheid, Nina and Thier, Marc Christian and Altamura, Sandro and Reyes, Alejandro and Prendergast, {\´A}ine M. and Baumg{\"a}rtner, Daniel and Carnevalli, Larissa S. and Atzberger, Ann and Haas, Simon and von Paleske, Lisa and Boroviak, Thorsten and W{\"o}rsd{\"o}rfer, Philipp and Essers, Marieke A. G. and Kloz, Ulrich and Eisenman, Robert N. and Edenhofer, Frank and Bertone, Paul and Huber, Wolfgang and van der Hoeven, Franciscus and Smith, Austin and Trumpp, Andreas},
  title     = {Myc depletion induces a pluripotent dormant state mimicking diapause},
  series = {Cell},
  volume    = {164},
  journal   = {Cell},
  number    = {4},
  doi       = {10.1016/j.cell.2015.12.033},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-190868},
  pages     = {668-680},
  year      = {2016},
  abstract  = {Mouse embryonic stem cells (ESCs) are maintained in a naive ground state of pluripotency in the presence of MEK and GSK3 inhibitors. Here, we show that ground-state ESCs express low Myc levels. Deletion of both c-myc and N-myc (dKO) or pharmacological inhibition of Myc activity strongly decreases transcription, splicing, and protein synthesis, leading to proliferation arrest. This process is reversible and occurs without affecting pluripotency, suggesting that Myc-depleted stem cells enter a state of dormancy similar to embryonic diapause. Indeed, c-Myc is depleted in diapaused blastocysts, and the differential expression signatures of dKO ESCs and diapaused epiblasts are remarkably similar. Following Myc inhibition, pre-implantation blastocysts enter biosynthetic dormancy but can progress through their normal developmental program after transfer into pseudo-pregnant recipients. Our study shows that Myc controls the biosynthetic machinery of stem cells without affecting their potency, thus regulating their entry and exit from the dormant state.},
  language  = {en}
}
@article{PeitzMuenstThummeretal.2014,
  author    = {Peitz, Michael and M{\"u}nst, Bernhard and Thummer, Rajkumar P. and Helfen, Martina and Edenhofer, Frank},
  title     = {Cell-permeant recombinant Nanog protein promotes pluripotency by inhibiting endodermal specification},
  series = {Stem Cell Research},
  volume    = {12},
  journal   = {Stem Cell Research},
  number    = {3},
  issn      = {1876-7753},
  doi       = {10.1016/j.scr.2014.02.006},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-119740},
  pages     = {680-689},
  year      = {2014},
  abstract  = {A comprehensive understanding of the functional network of transcription factors establishing and maintaining pluripotency is key for the development of biomedical applications of stem cells. Nanog plays an important role in early development and is essential to induce natural pluripotency in embryonic stem cells (ESCs). Inducible gain-of-function systems allowing a precise control over time and dosage of Nanog activity would be highly desirable to study its vital role in the establishment and maintenance of pluripotency at molecular level. Here we engineered a recombinant cell permeable version of Nanog by fusing it with the cell penetrating peptide TAT. Nanog-TAT can be readily expressed in and purified from E. coli and binds to a consensus Nanog DNA sequence. At cellular level it enhances proliferation and self-renewal of ESCs in the absence of leukemia inhibitory factor (LIF). Nanog-TAT together with LIF acts synergistically as judged by enhanced clonogenicity and activation of an Oct4-promoter-driven GFP reporter gene. Furthermore Nanog-TAT, in the absence of LIF, promotes pluripotency by inhibiting endodermal specification in a Stat3-independent manner. Our results demonstrate that Nanog protein transduction is an attractive tool allowing control over dose and time of addition to the cells for studying the molecular control of pluripotency without genetic manipulation.},
  language  = {en}
}
@unpublished{NoseWernerUedaetal.2018,
  author    = {Nose, Naoko and Werner, Rudolf A. and Ueda, Yuichiro and G{\"u}nther, Katharina and Lapa, Constantin and Javadi, Mehrbod S. and Fukushima, Kazuhito and Edenhofer, Frank and Higuchi, Takahiro},
  title     = {Metabolic substrate shift in human induced pluripotent stem cells during cardiac differentiation: Functional assessment using in vitro radionuclide uptake assay},
  series = {International Journal of Cardiology},
  journal   = {International Journal of Cardiology},
  issn      = {0167-5273},
  doi       = {10.1016/j.ijcard.2018.06.089},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-163320},
  year      = {2018},
  abstract  = {Background: Recent developments in cellular reprogramming technology enable the production of virtually unlimited numbers of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM). Although hiPSC-CM share various characteristic hallmarks with endogenous cardiomyocytes, it remains a question as to what extent metabolic characteristics are equivalent to mature mammalian cardiomyocytes. Here we set out to functionally characterize the metabolic status of hiPSC-CM in vitro by employing a radionuclide tracer uptake assay. Material and Methods: Cardiac differentiation of hiPSC was induced using a combination of well-orchestrated extrinsic stimuli such as WNT activation (by CHIR99021) and BMP signalling followed by WNT inhibition and lactate based cardiomyocyte enrichment. For characterization of metabolic substrates, dual tracer uptake studies were performed with \(^{18}\)F-2-fluoro-2-deoxy-D-glucose (\(^{18}\)F-FDG) and \(^{125}\)I-β-methyl-iodophenyl-pentadecanoic acid (\(^{125}\)I-BMIPP) as transport markers of glucose and fatty acids, respectively. Results: After cardiac differentiation of hiPSC, in vitro tracer uptake assays confirmed metabolic substrate shift from glucose to fatty acids that was comparable to those observed in native isolated human cardiomyocytes. Immunostaining further confirmed expression of fatty acid transport and binding proteins on hiPSC-CM. Conclusions: During in vitro cardiac maturation, we observed a metabolic shift to fatty acids, which are known as a main energy source of mammalian hearts, suggesting hi-PSC-CM as a potential functional phenotype to investigate alteration of cardiac metabolism in cardiac diseases. Results also highlight the use of available clinical nuclear medicine tracers as functional assays in stem cell research for improved generation of autologous differentiated cells for numerous biomedical applications.},
  subject      = {Stammzelle},
  language  = {en}
}
@article{NoseWernerUedaetal.2018,
  author    = {Nose, Naoko and Werner, Rudolf A. and Ueda, Yuichiro and G{\"u}nther, Katharina and Lapa, Constantin and Javadi, Mehrbod S. and Fukushima, Kazuhito and Edenhofer, Frank and Higuchi, Takahiro},
  title     = {Metabolic substrate shift in human induced pluripotent stem cells during cardiac differentiation: Functional assessment using in vitro radionuclide uptake assay},
  series = {International Journal of Cardiology},
  volume    = {269},
  journal   = {International Journal of Cardiology},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-170699},
  pages     = {229-234},
  year      = {2018},
  abstract  = {BACKGROUND: Recent developments in cellular reprogramming technology enable the production of virtually unlimited numbers of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM). Although hiPSC-CM share various characteristic hallmarks with endogenous cardiomyocytes, it remains a question as to what extent metabolic characteristics are equivalent to mature mammalian cardiomyocytes. Here we set out to functionally characterize the metabolic status of hiPSC-CM in vitro by employing a radionuclide tracer uptake assay. MATERIAL AND METHODS: Cardiac differentiation of hiPSC was induced using a combination of well-orchestrated extrinsic stimuli such as WNT activation (by CHIR99021) and BMP signalling followed by WNT inhibition and lactate based cardiomyocyte enrichment. For characterization of metabolic substrates, dual tracer uptake studies were performed with \(^{18}\)F‑2‑fluoro‑2‑deoxy‑d‑glucose (\(^{18}\)F-FDG) and \(^{125}\)I‑β‑methyl‑iodophenyl‑pentadecanoic acid (\(^{125}\)I-BMIPP) as transport markers of glucose and fatty acids, respectively. RESULTS: After cardiac differentiation of hiPSCs, in vitro tracer uptake assays confirmed metabolic substrate shift from glucose to fatty acids that was comparable to those observed in native isolated human cardiomyocytes. Immunostaining further confirmed expression of fatty acid transport and binding proteins on hiPSC-CM. CONCLUSIONS: During in vitro cardiac maturation, we observed a metabolic shift to fatty acids, which are known as a main energy source of mammalian hearts, suggesting hi-PSC-CM as a potential functional phenotype to investigate alteration of cardiac metabolism in cardiac diseases. Results also highlight the use of available clinical nuclear medicine tracers as functional assays in stem cell research for improved generation of autologous differentiated cells for numerous biomedical applications.},
  subject      = {Stammzelle},
  language  = {en}
}
@article{MuenstThierWinnemoelleretal.2016,
  author    = {M{\"u}nst, Bernhard and Thier, Marc Christian and Winnem{\"o}ller, Dirk and Helfen, Martina and Thummer, Rajkumar P. and Edenhofer, Frank},
  title     = {Nanog induces suppression of senescence through downregulation of p27\(^{KIP1}\) expression},
  series = {Journal of Cell Science},
  volume    = {129},
  journal   = {Journal of Cell Science},
  number    = {5},
  doi       = {10.1242/jcs.167932},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-190761},
  pages     = {912-920},
  year      = {2016},
  abstract  = {A comprehensive analysis of the molecular network of cellular factors establishing and maintaining pluripotency as well as self renewal of pluripotent stem cells is key for further progress in understanding basic stem cell biology. Nanog is necessary for the natural induction of pluripotency in early mammalian development but dispensable for both its maintenance and its artificial induction. To gain further insight into the molecular activity of Nanog, we analyzed the outcomes of Nanog gain-of-function in various cell models employing a recently developed biologically active recombinant cell-permeant protein, Nanog-TAT. We found that Nanog enhances the proliferation of both NIH 3T3 and primary fibroblast cells. Nanog transduction into primary fibroblasts results in suppression of senescence-associated beta-galactosidase activity. Investigation of cell cycle factors revealed that transient activation of Nanog correlates with consistent downregulation of the cell cycle inhibitor p27\(^{KIP1}\) (also known as CDKN1B). By performing chromatin immunoprecipitation analysis, we confirmed bona fide Nanog-binding sites upstream of the p27\(^{KIP1}\) gene, establishing a direct link between physical occupancy and functional regulation. Our data demonstrates that Nanog enhances proliferation of fibroblasts through transcriptional regulation of cell cycle inhibitor p27 gene.},
  language  = {en}
}
@article{KadariLuLietal.2014,
  author    = {Kadari, Asifiqbal and Lu, Min and Li, Ming and Sekaran, Thileepan and Thummer, Rajkumar P. and Guyette, Naomi and Chu, Vi and Edenhofer, Frank},
  title     = {Excision of viral reprogramming cassettes by Cre protein transduction enables rapid, robust and efficient derivation of transgene-free human induced pluripotent stem cells},
  series = {Stem Cell Research \& Therapy},
  volume    = {5},
  journal   = {Stem Cell Research \& Therapy},
  number    = {2},
  issn      = {1757-6512},
  doi       = {10.1186/scrt435},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-120578},
  pages     = {47},
  year      = {2014},
  abstract  = {Integrating viruses represent robust tools for cellular reprogramming; however, the presence of viral transgenes in induced pluripotent stem cells (iPSCs) is deleterious because it holds the risk of insertional mutagenesis leading to malignant transformation. Here, we combine the robustness of lentiviral reprogramming with the efficacy of Cre recombinase protein transduction to derive iPSCs devoid of transgenes. By genome-wide analysis and targeted differentiation towards the cardiomyocyte lineage, we show that transgene-free iPSCs are superior to iPSCs before Cre transduction. Our study provides a simple, rapid and robust protocol for the generation of clinical-grade iPSCs suitable for disease modeling, tissue engineering and cell replacement therapies.},
  language  = {en}
}
@article{JanzZinkCirnuetal.2021,
  author    = {Janz, Anna and Zink, Miriam and Cirnu, Alexandra and Hartleb, Annika and Albrecht, Christina and Rost, Simone and Klopocki, Eva and G{\"u}nther, Katharina and Edenhofer, Frank and Erg{\"u}n, S{\"u}leyman and Gerull, Brenda},
  title     = {CRISPR/Cas9-edited PKP2 knock-out (JMUi001-A-2) and DSG2 knock-out (JMUi001-A-3) iPSC lines as an isogenic human model system for arrhythmogenic cardiomyopathy (ACM)},
  series = {Stem Cell Research},
  volume    = {53},
  journal   = {Stem Cell Research},
  doi       = {10.1016/j.scr.2021.102256},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-259846},
  pages     = {102256},
  year      = {2021},
  abstract  = {Arrhythmogenic cardiomyopathy (ACM) is characterized by fibro-fatty replacement of the myocardium, heart failure and life-threatening ventricular arrhythmias. Causal mutations were identified in genes encoding for proteins of the desmosomes, predominantly plakophilin-2 (PKP2) and desmoglein-2 (DSG2). We generated gene-edited knock-out iPSC lines for PKP2 (JMUi001-A-2) and DSG2 (JMUi001-A-3) using the CRISPR/Cas9 system in a healthy control iPSC background (JMUi001A). Stem cell-like morphology, robust expression of pluripotency markers, embryoid body formation and normal karyotypes confirmed the generation of high quality iPSCs to provide a novel isogenic human in vitro model system mimicking ACM when differentiated into cardiomyocytes.},
  language  = {en}
}
@article{JanschGuentherWaideretal.2018,
  author    = {Jansch, Charline and G{\"u}nther, Katharina and Waider, Jonas and Ziegler, Georg C. and Forero, Andrea and Kollert, Sina and Svirin, Evgeniy and P{\"u}hringer, Dirk and Kwok, Chee Keong and Ullmann, Reinhard and Maierhofer, Anna and Flunkert, Julia and Haaf, Thomas and Edenhofer, Frank and Lesch, Klaus-Peter},
  title     = {Generation of a human induced pluripotent stem cell (iPSC) line from a 51-year-old female with attention-deficit/hyperactivity disorder (ADHD) carrying a duplication of SLC2A3},
  series = {Stem Cell Research},
  volume    = {28},
  journal   = {Stem Cell Research},
  doi       = {10.1016/j.scr.2018.02.005},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-176654},
  pages     = {136-140},
  year      = {2018},
  abstract  = {Fibroblasts were isolated from a skin biopsy of a clinically diagnosed 51-year-old female attention-deficit/hyperactivity disorder (ADHD) patient carrying a duplication of SLC2A3, a gene encoding neuronal glucose transporter-3 (GLUT3). Patient fibroblasts were infected with Sendai virus, a single-stranded RNA virus, to generate transgene-free human induced pluripotent stem cells (iPSCs). SLC2A3-D2-iPSCs showed expression of pluripotency-associated markers, were able to differentiate into cells of the three germ layers in vitro and had a normal female karyotype. This in vitro cellular model can be used to study the role of risk genes in the pathogenesis of ADHD, in a patient-specific manner.},
  language  = {en}
}
@article{HarreitherRydbergAmandetal.2014,
  author    = {Harreither, Eva and Rydberg, Hanna A. and {\AA}mand, Helene L. and Jadhav, Vaibhav and Fliedl, Lukas and Benda, Christina and Esteban, Miguel A. and Pei, Duanqing and Borth, Nicole and Grillari-Voglauer, Regina and Hommerding, Oliver and Edenhofer, Frank and Nord{\´e}n, Bengt and Grillari, Johanne},
  title     = {Characterization of a novel cell penetrating peptide derived from human Oct4},
  series = {Cell Regeneration},
  volume    = {3},
  journal   = {Cell Regeneration},
  number    = {2},
  issn      = {2045-9769},
  doi       = {10.1186/2045-9769-3-2},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-120999},
  year      = {2014},
  abstract  = {BACKGROUND: Oct4 is a transcription factor that plays a major role for the preservation of the pluripotent state in embryonic stem cells as well as for efficient reprogramming of somatic cells to induced pluripotent stem cells (iPSC) or other progenitors. Protein-based reprogramming methods mainly rely on the addition of a fused cell penetrating peptide. This study describes that Oct4 inherently carries a protein transduction domain, which can translocate into human and mouse cells. RESULTS: A 16 amino acid peptide representing the third helix of the human Oct4 homeodomain, referred to as Oct4 protein transduction domain (Oct4-PTD), can internalize in mammalian cells upon conjugation to a fluorescence moiety thereby acting as a cell penetrating peptide (CPP). The cellular distribution of Oct4-PTD shows diffuse cytosolic and nuclear staining, whereas penetratin is strictly localized to a punctuate pattern in the cytoplasm. By using a Cre/loxP-based reporter system, we show that this peptide also drives translocation of a functionally active Oct4-PTD-Cre-fusion protein. We further provide evidence for translocation of full length Oct4 into human and mouse cell lines without the addition of any kind of cationic fusion tag. Finally, physico-chemical properties of the novel CPP are characterized, showing that in contrast to penetratin a helical structure of Oct4-PTD is only observed if the FITC label is present on the N-terminus of the peptide. CONCLUSIONS: Oct4 is a key transcription factor in stem cell research and cellular reprogramming. Since it has been shown that recombinant Oct4 fused to a cationic fusion tag can drive generation of iPSCs, our finding might contribute to further development of protein-based methods to generate iPSCs. Moreover, our data support the idea that transcription factors might be part of an alternative paracrine signalling pathway, where the proteins are transferred to neighbouring cells thereby actively changing the behaviour of the recipient cell.},
  language  = {en}
}
@article{FereroRiveroWaeldchenetal.2017,
  author    = {Ferero, Andrea and Rivero, Olga and W{\"a}ldchen, Sina and Ku, Hsing-Ping and Kiser, Dominik P. and G{\"a}rtner, Yvonne and Pennington, Laura S. and Waider, Jonas and Gaspar, Patricia and Jansch, Charline and Edenhofer, Frank and Resink, Th{\´e}r{\`e}se J. and Blum, Robert and Sauer, Markus and Lesch, Klaus-Peter},
  title     = {Cadherin-13 Deficiency Increases Dorsal Raphe 5-HT Neuron Density and Prefrontal Cortex Innervation in the Mouse Brain},
  series = {Frontiers in Cellular Neuroscience},
  volume    = {11},
  journal   = {Frontiers in Cellular Neuroscience},
  number    = {307},
  doi       = {10.3389/fncel.2017.00307},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-170313},
  year      = {2017},
  abstract  = {Background: During early prenatal stages of brain development, serotonin (5-HT)-specific neurons migrate through somal translocation to form the raphe nuclei and subsequently begin to project to their target regions. The rostral cluster of cells, comprising the median and dorsal raphe (DR), innervates anterior regions of the brain, including the prefrontal cortex. Differential analysis of the mouse 5-HT system transcriptome identified enrichment of cell adhesion molecules in 5-HT neurons of the DR. One of these molecules, cadherin-13 (Cdh13) has been shown to play a role in cell migration, axon pathfinding, and synaptogenesis. This study aimed to investigate the contribution of Cdh13 to the development of the murine brain 5-HT system. Methods: For detection of Cdh13 and components of the 5-HT system at different embryonic developmental stages of the mouse brain, we employed immunofluorescence protocols and imaging techniques, including epifluorescence, confocal and structured illumination microscopy. The consequence of CDH13 loss-of-function mutations on brain 5-HT system development was explored in a mouse model of Cdh13 deficiency. Results: Our data show that in murine embryonic brain Cdh13 is strongly expressed on 5-HT specific neurons of the DR and in radial glial cells (RGCs), which are critically involved in regulation of neuronal migration. We observed that 5-HT neurons are intertwined with these RGCs, suggesting that these neurons undergo RGC-guided migration. Cdh13 is present at points of intersection between these two cell types. Compared to wildtype controls, Cdh13-deficient mice display increased cell densities in the DR at embryonic stages E13.5, E17.5, and adulthood, and higher serotonergic innervation of the prefrontal cortex at E17.5. Conclusion: Our findings provide evidence for a role of CDH13 in the development of the serotonergic system in early embryonic stages. Specifically, we indicate that Cdh13 deficiency affects the cell density of the developing DR and the posterior innervation of the prefrontal cortex (PFC), and therefore might be involved in the migration, axonal outgrowth and terminal target finding of DR 5-HT neurons. Dysregulation of CDH13 expression may thus contribute to alterations in this system of neurotransmission, impacting cognitive function, which is frequently impaired in neurodevelopmental disorders including attention-deficit/hyperactivity and autism spectrum disorders.},
  language  = {en}
}