@article{DegenkolbeKoenigZimmeretal.2013, author = {Degenkolbe, Elisa and K{\"o}nig, Jana and Zimmer, Julia and Walther, Maria and Reißner, Carsten and Nickel, Joachim and Pl{\"o}ger, Frank and Raspopovic, Jelena and Sharpe, James and Dathe, Katharina and Hecht, Jacqueline T. and Mundlos, Stefan and Doelken, Sandra C. and Seemann, Petra}, title = {A GDF5 Point Mutation Strikes Twice - Causing BDA1 and SYNS2}, series = {PLOS Genetics}, volume = {9}, journal = {PLOS Genetics}, number = {10}, issn = {1553-7404}, doi = {10.1371/journal.pgen.1003846}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-127556}, pages = {e1003846}, year = {2013}, abstract = {Growth and Differentiation Factor 5 (GDF5) is a secreted growth factor that belongs to the Bone Morphogenetic Protein (BMP) family and plays a pivotal role during limb development. GDF5 is a susceptibility gene for osteoarthritis (OA) and mutations in GDF5 are associated with a wide variety of skeletal malformations ranging from complex syndromes such as acromesomelic chondrodysplasias to isolated forms of brachydactylies or multiple synostoses syndrome 2 (SYNS2). Here, we report on a family with an autosomal dominant inherited combination of SYNS2 and additional brachydactyly type A1 (BDA1) caused by a single point mutation in GDF5 (p.W414R). Functional studies, including chondrogenesis assays with primary mesenchymal cells, luciferase reporter gene assays and Surface Plasmon Resonance analysis, of the GDF5 W-414R variant in comparison to other GDF5 mutations associated with isolated BDA1 (p.R399C) or SYNS2 (p.E491K) revealed a dual pathomechanism characterized by a gain-and loss-of-function at the same time. On the one hand insensitivity to the main GDF5 antagonist NOGGIN (NOG) leads to a GDF5 gain of function and subsequent SYNS2 phenotype. Whereas on the other hand, a reduced signaling activity, specifically via the BMP receptor type IA (BMPR1A), is likely responsible for the BDA1 phenotype. These results demonstrate that one mutation in the overlapping interface of antagonist and receptor binding site in GDF5 can lead to a GDF5 variant with pathophysiological relevance for both, BDA1 and SYNS2 development. Consequently, our study assembles another part of the molecular puzzle of how loss and gain of function mutations in GDF5 affect bone development in hands and feet resulting in specific types of brachydactyly and SYNS2. These novel insights into the biology of GDF5 might also provide further clues on the pathophysiology of OA.}, language = {en} } @article{BarnekowGessler1986, author = {Barnekow, Angelika and Gessler, Manfred}, title = {Activation of the pp60\(^{c-src}\) kinase during differentiation of monomyelocytic cells in vitro}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59278}, year = {1986}, abstract = {Tbe proto-oncogene c-src, the cellular homolog of the Rous sarcoma virus (RSV) transforming gene v-src, is expressed in a tissue-specific and age-dependent manner. Its physiological function, although still unknown, appears to be more closely related to differentiation processes than to proliferation processes. To obtain more information about the physiological role of the c-src gene in cells, we have studied differentiation-dependent alterations using the human HL-60 leukaemia cell line as a model system. Induction of monocytic and granulocytic differentiation of HL-60 cells by 12-0-tetradecanoylphorbol-13-acetate (TPA) and dimethylsulfoxide (DMSO) is associated with an activation of the pp60c-src tyrosine kinase, but not with increased c-src gene expression. Control experiments exclude an interaction of TPA and DMSO themselves with the pp60c-src kinase.}, subject = {Biochemie}, language = {en} } @article{KarlDandekar2015, author = {Karl, Stefan and Dandekar, Thomas}, title = {Convergence behaviour and control in non-linear biological networks}, series = {Scientific Reports}, volume = {5}, journal = {Scientific Reports}, number = {09746}, doi = {10.1038/srep09746}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-148510}, year = {2015}, abstract = {Control of genetic regulatory networks is challenging to define and quantify. Previous control centrality metrics, which aim to capture the ability of individual nodes to control the system, have been found to suffer from plausibility and applicability problems. Here we present a new approach to control centrality based on network convergence behaviour, implemented as an extension of our genetic regulatory network simulation framework Jimena (http://stefan-karl.de/jimena). We distinguish three types of network control, and show how these mathematical concepts correspond to experimentally verified node functions and signalling pathways in immunity and cell differentiation: Total control centrality quantifies the impact of node mutations and identifies potential pharmacological targets such as genes involved in oncogenesis (e.g. zinc finger protein GLI2 or bone morphogenetic proteins in chondrocytes). Dynamic control centrality describes relaying functions as observed in signalling cascades (e.g. src kinase or Jak/Stat pathways). Value control centrality measures the direct influence of the value of the node on the network (e.g. Indian hedgehog as an essential regulator of proliferation in chondrocytes). Surveying random scale-free networks and biological networks, we find that control of the network resides in few high degree driver nodes and networks can be controlled best if they are sparsely connected.}, language = {en} } @article{BugaScholzKumaretal.2012, author = {Buga, Ana-Maria and Scholz, Claus J{\"u}rgen and Kumar, Senthil and Herndon, James G. and Alexandru, Dragos and Cojocaru, Gabriel Radu and Dandekar, Thomas and Popa-Wagner, Aurel}, title = {Identification of New Therapeutic Targets by Genome-Wide Analysis of Gene Expression in the Ipsilateral Cortex of Aged Rats after Stroke}, series = {PLoS One}, volume = {7}, journal = {PLoS One}, number = {12}, doi = {10.1371/journal.pone.0050985}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-130657}, pages = {e50985}, year = {2012}, abstract = {Background: Because most human stroke victims are elderly, studies of experimental stroke in the aged rather than the young rat model may be optimal for identifying clinically relevant cellular responses, as well for pinpointing beneficial interventions. Methodology/Principal Findings: We employed the Affymetrix platform to analyze the whole-gene transcriptome following temporary ligation of the middle cerebral artery in aged and young rats. The correspondence, heat map, and dendrogram analyses independently suggest a differential, age-group-specific behaviour of major gene clusters after stroke. Overall, the pattern of gene expression strongly suggests that the response of the aged rat brain is qualitatively rather than quantitatively different from the young, i.e. the total number of regulated genes is comparable in the two age groups, but the aged rats had great difficulty in mounting a timely response to stroke. Our study indicates that four genes related to neuropathic syndrome, stress, anxiety disorders and depression (Acvr1c, Cort, Htr2b and Pnoc) may have impaired response to stroke in aged rats. New therapeutic options in aged rats may also include Calcrl, Cyp11b1, Prcp, Cebpa, Cfd, Gpnmb, Fcgr2b, Fcgr3a, Tnfrsf26, Adam 17 and Mmp14. An unexpected target is the enzyme 3-hydroxy-3-methylglutaryl-Coenzyme A synthase 1 in aged rats, a key enzyme in the cholesterol synthesis pathway. Post-stroke axonal growth was compromised in both age groups. Conclusion/Significance: We suggest that a multi-stage, multimodal treatment in aged animals may be more likely to produce positive results. Such a therapeutic approach should be focused on tissue restoration but should also address other aspects of patient post-stroke therapy such as neuropathic syndrome, stress, anxiety disorders, depression, neurotransmission and blood pressure.}, language = {en} } @article{SanzMorenoFuhrmannWolfetal.2014, author = {Sanz-Moreno, Adrian and Fuhrmann, David and Wolf, Elmar and von Eyss, Bj{\"o}rn and Eilers, Martin and Els{\"a}sser, Hans-Peter}, title = {Miz1 Deficiency in the Mammary Gland Causes a Lactation Defect by Attenuated Stat5 Expression and Phosphorylation}, series = {PLOS ONE}, volume = {9}, journal = {PLOS ONE}, number = {2}, doi = {10.1371/journal.pone.0089187}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-117286}, pages = {e89187}, year = {2014}, abstract = {Miz1 is a zinc finger transcription factor with an N-terminal POZ domain. Complexes with Myc, Bcl-6 or Gfi-1 repress expression of genes like Cdkn2b (p15(Ink4)) or Cd-kn1a (p21(Cip1)). The role of Miz1 in normal mammary gland development has not been addressed so far. Conditional knockout of the Miz1 POZ domain in luminal cells during pregnancy caused a lactation defect with a transient reduction of glandular tissue, reduced proliferation and attenuated differentiation. This was recapitulated in vitro using mouse mammary gland derived HC11 cells. Further analysis revealed decreased Stat5 activity in Miz1 Delta POZ mammary glands and an attenuated expression of Stat5 targets. Gene expression of the Prolactin receptor (PrlR) and ErbB4, both critical for Stat5 phosphorylation (pStat5) or pStat5 nuclear translocation, was decreased in Miz1 Delta POZ females. Microarray, ChIP-Seq and gene set enrichment analysis revealed a down-regulation of Miz1 target genes being involved in vesicular transport processes. Our data suggest that deranged intracellular transport and localization of PrlR and ErbB4 disrupt the Stat5 signalling pathway in mutant glands and cause the observed lactation phenotype.}, language = {en} } @article{HoennemannSanzMorenoWolfetal.2012, author = {H{\"o}nnemann, Jan and Sanz-Moreno, Adrian and Wolf, Elmar and Eilers, Martin and Els{\"a}sser, Hans-Peter}, title = {Miz1 Is a Critical Repressor of cdkn1a during Skin Tumorigenesis}, series = {PLoS One}, volume = {7}, journal = {PLoS One}, number = {4}, doi = {10.1371/journal.pone.0034885}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-133285}, pages = {e34885}, year = {2012}, abstract = {The transcription factor Miz1 forms repressive DNA-binding complexes with the Myc, Gfi-1 and Bcl-6 oncoproteins. Known target genes of these complexes encode the cyclin-dependent kinase inhibitors (CKIs) cdkn2b (p15\(^{Ink4}\)), cdkn1a (p21\(^{Cip1}\)), and cdkn1c (p57\(^{Kip2}\)). Whether Miz1-mediated repression is important for control of cell proliferation in vivo and for tumor formation is unknown. Here we show that deletion of the Miz1 POZ domain, which is critical for Miz1 function, restrains the development of skin tumors in a model of chemically-induced, Ras-dependent tumorigenesis. While the stem cell compartment appears unaffected, interfollicular keratinocytes lacking functional Miz1 exhibit a reduced proliferation and an accelerated differentiation of the epidermis in response to the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA). Tumorigenesis, proliferation and normal differentiation are restored in animals lacking cdkn1a, but not in those lacking cdkn2b. Our data demonstrate that Miz1-mediated attenuation of cell cycle arrest pathways via repression of cdkn1a has a critical role during tumorigenesis in the skin.}, language = {en} } @article{YanHongChenetal.2013, author = {Yan, Yan and Hong, Ni and Chen, Tiansheng and Li, Mingyou and Wang, Tiansu and Guan, Guijun and Qiao, Yongkang and Chen, Songlin and Schartl, Manfred and Li, Chang-Ming and Hong, Yunhan}, title = {p53 Gene Targeting by Homologous Recombination in Fish ES Cells}, series = {PLoS One}, volume = {8}, journal = {PLoS One}, number = {3}, doi = {10.1371/journal.pone.0059400}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-133416}, pages = {e59400}, year = {2013}, abstract = {Background: Gene targeting (GT) provides a powerful tool for the generation of precise genetic alterations in embryonic stem (ES) cells to elucidate gene function and create animal models for human diseases. This technology has, however, been limited to mouse and rat. We have previously established ES cell lines and procedures for gene transfer and selection for homologous recombination (HR) events in the fish medaka (Oryzias latipes). Methodology and Principal Findings: Here we report HR-mediated GT in this organism. We designed a GT vector to disrupt the tumor suppressor gene p53 (also known as tp53). We show that all the three medaka ES cell lines, MES1 similar to MES3, are highly proficient for HR, as they produced detectable HR without drug selection. Furthermore, the positive-negative selection (PNS) procedure enhanced HR by similar to 12 folds. Out of 39 PNS-resistant colonies analyzed, 19 (48.7\%) were positive for GT by PCR genotyping. When 11 of the PCR-positive colonies were further analyzed, 6 (54.5\%) were found to be bona fide homologous recombinants by Southern blot analysis, sequencing and fluorescent in situ hybridization. This produces a high efficiency of up to 26.6\% for p53 GT under PNS conditions. We show that p53 disruption and long-term propagation under drug selection conditions do not compromise the pluripotency, as p53-targeted ES cells retained stable growth, undifferentiated phenotype, pluripotency gene expression profile and differentiation potential in vitro and in vivo. Conclusions: Our results demonstrate that medaka ES cells are proficient for HR-mediated GT, offering a first model organism of lower vertebrates towards the development of full ES cell-based GT technology.}, language = {en} }