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Elisabeth Kemter,
Petra Prueckl,
Stefanie Sklenak,
Birgit Rathkolb,
Felix A Habermann,
Wolfgang Hans, Valérie Gailus-Durner,
Helmut Fuchs,
Martin Hrabe de Angelis,
Eckhard Wolf,
Bernhard Aigner,
Ruediger Wanke
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ABSTRACT: Uromodulin-associated kidney disease (UAKD) is a dominant heritable renal disease in humans which is caused by mutations in the uromodulin (UMOD) gene and characterized by heterogeneous clinical appearance. To get insights into possible causes of this heterogeneity of UAKD, we describe the new mutant mouse line Umod(C93F), leading to disruption of a putative disulfide bond which is also absent in a known human UMOD mutation, and compare the phenotype of this new mouse line with the recently published mouse line Umod(A227T). In both mutant mouse lines, which were both bred on the C3H background, the Umod mutations cause a gain-of-toxic function due to a maturation defect of the mutant uromodulin leading to a dysfunction of thick ascending limb of Henle's loop (TALH) cells of the kidney. Umod mutant mice exhibit increased plasma urea and cystatin levels, impaired urinary concentration ability, reduced fractional excretion of uric acid, and nephropathological alterations including uromodulin retention in TALH cells, interstitial fibrosis and inflammatory cell infiltrations, tubular atrophy, and occasional glomerulo- und tubulocystic changes, a phenotype highly similar to UAKD in humans. The maturation defect of mutant uromodulin leads to the accumulation of immature uromodulin in the endoplasmic reticulum (ER) and to ER hyperplasia. Further, this study was able to demonstrate for the first time in vivo that the severity of the uromodulin maturation defect as well as onset and speed of progression of renal dysfunction and morphological alterations are strongly dependent on the particular Umod mutation itself and the zygosity status.
Human Molecular Genetics 06/2013; · 7.64 Impact Factor
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Katrin Hochrath,
Sabrina Ehnert,
Cheryl L Ackert-Bicknell,
Yvonne Lau,
Andrea Schmid,
Marcin Krawczyk,
Jan G Hengstler,
Jordanne Dunn,
Kanishka Hiththetiya,
Birgit Rathkolb, [......],
Wolfgang Hans,
Helmut Fuchs, Valérie Gailus-Durner,
Eckhard Wolf,
Martin Hrabě de Angelis,
Steven Dooley,
Beverly Paigen,
Britt Wildemann,
Frank Lammert,
Andreas K Nüssler
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ABSTRACT: Hepatic osteodystrophy (HOD) denotes the alterations in bone morphology and metabolism frequently observed in patients with chronic liver diseases, in particular in case of cholestatic conditions. The molecular mechanisms underlying HOD are only partially understood. In the present study, we characterized the bone phenotypes of the ATP-binding cassette transporter B4 knockout mouse (Abcb4(-/-)), a well-established mouse model of chronic cholestatic liver disease, with the aim of identifying and characterizing a mouse model for HOD. Furthermore, we investigated the influence of vitamin D on bone quality in this model. The bone morphology analyses revealed reduced bone mineral contents as well as changes in trabecular bone architecture and decreased cortical bone densities in Abcb4(-/-) mice with severe liver fibrosis. We observed dysregulation of genes involved in bone remodeling (osteoprotegerin, osteocalcin, osteopontin) and vitamin D metabolism (7-dehydrocholesterol reductase, Gc-globulin, Cyp2r1, Cyp27a1) as well as alterations in calcium and vitamin D homeostasis. In addition, serum RANKL and TGF-β levels were increased in Abcb4(-/-) mice. Vitamin D dietary intervention was only partially able to restore the bone phenotypes of Abcb4(-/-) animals. We conclude that the Abcb4(-/-) mouse provides an experimental framework and a preclinical model to gain further insights into the molecular pathobiology of HOD and to study the systemic effects of therapeutic interventions.
Bone 03/2013; · 4.02 Impact Factor
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Limei Ju,
Jonathan Wing,
Elaine Taylor,
Renata Brandt,
Predrag Slijepcevic,
Marion Horsch,
Birgit Rathkolb,
Ildikó Rácz,
Lore Becker,
Wolfgang Hans, [......],
Martin Klingenspor,
Eckhard Wolf,
Andreas Zimmer,
Thomas Klopstock,
Dirk H Busch, Valérie Gailus-Durner,
Helmut Fuchs,
Martin Hrabě de Angelis,
Gilbertus van der Horst,
Alan R Lehmann
[show abstract]
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ABSTRACT: Smc5-6 is a highly conserved protein complex related to cohesin and condensin involved in the structural maintenance of chromosomes. In yeasts the Smc5-6 complex is essential for proliferation and is involved in DNA repair and homologous recombination. siRNA depletion of genes involved in the Smc5-6 complex in cultured mammalian cells results in sensitivity to some DNA damaging agents. In order to gain further insight into its role in mammals we have generated mice mutated in the Smc6 gene. A complete knockout resulted in early embryonic lethality, demonstrating that this gene is essential in mammals. However, mutation of the highly conserved serine-994 to alanine in the ATP hydrolysis motif in the SMC6 C-terminal domain, resulted in mice with a surprisingly mild phenotype. With the neo gene selection marker in the intron following the mutation, resulting in reduced expression of the SMC6 gene, the mice were reduced in size, but fertile and had normal lifespans. When the neo gene was removed, the mice had normal size, but detailed phenotypic analysis revealed minor abnormalities in glucose tolerance, haematopoiesis, nociception and global gene expression patterns. Embryonic fibroblasts derived from the ser994 mutant mice were not sensitive to killing by a range of DNA damaging agents, but they were sensitive to the induction of sister chromatid exchanges induced by ultraviolet light or mitomycin C. They also accumulated more oxidative damage than wild-type cells.
DNA repair 03/2013; · 4.20 Impact Factor
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ABSTRACT: Within a mutagenesis screen, we identified the new mouse mutant Aey80 with small eyes; homozygous mutants were not obtained. The aim of the study was its molecular characterization.
We analyzed the offspring of paternally N-ethyl-N-nitrosourea (ENU)-treated C3HeB/FeJ mice for dysmorphology parameters, which can be observed with the naked eye. The Aey80 mutant (abnormality of the eye) was further characterized with laser interference biometry, Scheimpflug imaging, and optical coherence tomography. Linkage analysis of the Aey80 mutant was performed using a panel of single nucleotide polymorphisms different among C3HeB/FeJ and C57BL/6J mice. The Aey80 mutation was identified with sequence analysis of the positional candidate gene.
We identified a new mutant characterized by an obvious small-eye phenotype; homozygotes are not viable after birth. Embryos at embryonic day 15.5 demonstrate a clear gene-dosage effect: Heterozygotes have small eyes, whereas homozygous mutants do not have eyes. In adult mice, the lenses and the entire eyes of the heterozygous mutants were significantly smaller than those of the wild-types (p<0.01). No other ocular phenotypes were observed; the lenses were fully transparent, and no adhesion to the cornea was observed. The mutation was mapped to chromosome 2; markers between 70.8 MB and 129.5 MB showed significant linkage to the mutation resulting in paired box gene 6 (Pax6) as an excellent candidate gene. We amplified cDNAs from the embryonic eyes and observed an additional band while amplifying the region corresponding to exons 7 and 8. The additional band included an alternative exon of 141 bp, which was associated with a G->A exchange four bases downstream of the end of the alternative exon. The alternative exon in the mutants is predicted to encode 30 novel amino acids and three stop codons. This alternative exon kept the paired domain intact but led to a loss of the homeodomain and the C-terminal proline-serine-threonine (PST) domain. The mutation cosegregated in the mutant line, since all five additional small-eyed mice from this line showed the same mutation. A general polymorphism at the mutated site was excluded with sequence analysis of seven other wild-type mouse strains different from C3HeB/FeJ.
These findings demonstrate a novel allele of the paired box gene 6 (Pax6) that affects lens development in a semidominant manner leading to a classical small-eye phenotype. However, the site of the mutation more than 1 kb downstream of exon 7 and resulting in an alternative exon is quite unusual. It indicates the importance of sequence analysis of cDNA for mutation detection; mutations like this are unlikely to be identified by analyzing genomic sequences only. Moreover, this particular mutation demonstrates how a novel exon can be created by only a single base-pair exchange.
Molecular vision 01/2013; 19:877-884. · 2.20 Impact Factor
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Tomáš Venit,
Rastislav Dzijak,
Alžběta Kalendová,
Michal Kahle,
Jana Rohožková,
Volker Schmidt,
Thomas Rülicke,
Birgit Rathkolb,
Wolfgang Hans,
Alexander Bohla,
Oliver Eickelberg,
Tobias Stoeger,
Eckhard Wolf,
Ali Önder Yildirim, Valérie Gailus-Durner,
Helmut Fuchs,
Martin Hrabě de Angelis,
Pavel Hozák
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ABSTRACT: Nuclear myosin I (NM1) is a nuclear isoform of the well-known "cytoplasmic" Myosin 1c protein (Myo1c). Located on the 11(th) chromosome in mice, NM1 results from an alternative start of transcription of the Myo1c gene adding an extra 16 amino acids at the N-terminus. Previous studies revealed its roles in RNA Polymerase I and RNA Polymerase II transcription, chromatin remodeling, and chromosomal movements. Its nuclear localization signal is localized in the middle of the molecule and therefore directs both Myosin 1c isoforms to the nucleus.
In order to trace specific functions of the NM1 isoform, we generated mice lacking the NM1 start codon without affecting the cytoplasmic Myo1c protein. Mutant mice were analyzed in a comprehensive phenotypic screen in cooperation with the German Mouse Clinic. Strikingly, no obvious phenotype related to previously described functions has been observed. However, we found minor changes in bone mineral density and the number and size of red blood cells in knock-out mice, which are most probably not related to previously described functions of NM1 in the nucleus. In Myo1c/NM1 depleted U2OS cells, the level of Pol I transcription was restored by overexpression of shRNA-resistant mouse Myo1c. Moreover, we found Myo1c interacting with Pol II. The ratio between Myo1c and NM1 proteins were similar in the nucleus and deletion of NM1 did not cause any compensatory overexpression of Myo1c protein.
We observed that Myo1c can replace NM1 in its nuclear functions. Amount of both proteins is nearly equal and NM1 knock-out does not cause any compensatory overexpression of Myo1c. We therefore suggest that both isoforms can substitute each other in nuclear processes.
PLoS ONE 01/2013; 8(4):e61406. · 4.09 Impact Factor
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Katrin Hochrath,
Marcin Krawczyk,
Reinhild Goebel,
Miriam Langhirt,
Birgit Rathkolb,
Kateryna Micklich,
Jan Rozman,
Marion Horsch,
Johannes Beckers,
Martin Klingenspor,
Helmut Fuchs, Valérie Gailus-Durner,
Eckhard Wolf,
Monica Acalovschi,
Dietrich A Volmer,
Martin Hrabe de Angelis,
Frank Lammert
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ABSTRACT: The hepatic phosphatidylcholine (PC) transporter ATP-binding cassette (ABC) B4 flops PC from hepatocytes into bile, and its dysfunction causes chronic cholestasis and fibrosis. Because a nuclear receptor-dependent PC pathway has been determined to exert antidiabetic effects, we now analyzed the role of ABCB4 in glucose metabolism. We bred congenic Abcb4-knockout (Abcb4(-/-)) mice on the fibrosis-susceptible BALB/cJ background. Knockout mice and wild-type controls were phenotyped by measuring plasma glucose concentrations, intraperitoneal glucose tolerance, hepatic RNA expression profiles, and liver histology. In addition, 4 procholestatic ABCB4 gene variants were correlated with blood glucose levels in 682 individuals from 2 independent European cohorts. Systemic glucose levels differ significantly between Abcb4(-/-) mice and wild-type controls, and knockout mice display improved glucose tolerance with significantly lower area under the curve values on intraperitoneal glucose challenge. Of note, hepatic expression of the antidiabetic nuclear receptor 5A2 (LRH-1) is induced consistently in Abcb4(-/-) mice, and its specific rare PC ligands are detected in liver by mass spectrometry imaging. In humans, serum glucose levels are associated significantly with the common ABCB4 variant c.711A>T. In summary, ABCB4 might play a critical role in glucose homeostasis in mice and humans. We speculate that the effects could be mediated via LRH-1-dependent PC pathways.-Hochrath, K., Krawczyk, M., Goebel, R., Langhirt, M., Rathkolb, B., Micklich, K., Rozman, J., Horsch, M., Beckers, J., Klingenspor, M., Fuchs, H., Gailus-Durner, V., Wolf, E., Acalovschi, M., Volmer, D. A., Hrabě de Angelis, M., Lammert, F. The hepatic phosphatidylcholine transporter ABCB4 as modulator of glucose homeostasis.
The FASEB Journal 09/2012; · 5.71 Impact Factor
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Abdel Ayadi,
Marie-Christine Birling,
Joanna Bottomley,
James Bussell,
Helmut Fuchs,
Martin Fray, Valérie Gailus-Durner,
Simon Greenaway,
Richard Houghton,
Natasha Karp, [......],
Alison Walling,
Tom Weaver,
Sara Wells,
Jacqui K White,
Allan Bradley,
David J Adams,
Karen P Steel,
Martin Hrabě de Angelis,
Steve D Brown,
Yann Herault
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ABSTRACT: Two large-scale phenotyping efforts, the European Mouse Disease Clinic (EUMODIC) and the Wellcome Trust Sanger Institute Mouse Genetics Project (SANGER-MGP), started during the late 2000s with the aim to deliver a comprehensive assessment of phenotypes or to screen for robust indicators of diseases in mouse mutants. They both took advantage of available mouse mutant lines but predominantly of the embryonic stem (ES) cells resources derived from the European Conditional Mouse Mutagenesis programme (EUCOMM) and the Knockout Mouse Project (KOMP) to produce and study 799 mouse models that were systematically analysed with a comprehensive set of physiological and behavioural paradigms. They captured more than 400 variables and an additional panel of metadata describing the conditions of the tests. All the data are now available through EuroPhenome database ( www.europhenome.org ) and the WTSI mouse portal ( http://www.sanger.ac.uk/mouseportal/ ), and the corresponding mouse lines are available through the European Mouse Mutant Archive (EMMA), the International Knockout Mouse Consortium (IKMC), or the Knockout Mouse Project (KOMP) Repository. Overall conclusions from both studies converged, with at least one phenotype scored in at least 80 % of the mutant lines. In addition, 57 % of the lines were viable, 13 % subviable, 30 % embryonic lethal, and 7 % displayed fertility impairments. These efforts provide an important underpinning for a future global programme that will undertake the complete functional annotation of the mammalian genome in the mouse model.
Mammalian Genome 09/2012; 23(9-10):600-10. · 2.89 Impact Factor
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Helmut Fuchs, Valérie Gailus-Durner,
Susanne Neschen,
Thure Adler,
Luciana Caminha Afonso,
Juan Antonio Aguilar-Pimentel,
Lore Becker,
Alexander Bohla,
Julia Calzada-Wack,
Christian Cohrs, [......],
Thomas Klopstock,
Frauke Neff,
Markus Ollert,
Holger Schulz,
Tobias Stöger,
Eckhard Wolf,
Wolfgang Wurst,
Ali Onder Yildirim,
Andreas Zimmer,
Martin Hrabě de Angelis
[show abstract]
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ABSTRACT: Under the label of the German Mouse Clinic (GMC), a concept has been developed and implemented that allows the better understanding of human diseases on the pathophysiological and molecular level. This includes better understanding of the crosstalk between different organs, pleiotropy of genes, and the systemic impact of envirotypes and drugs. In the GMC, experts from various fields of mouse genetics and physiology, in close collaboration with clinicians, work side by side under one roof. The GMC is an open-access platform for the scientific community by providing phenotypic analysis in bilateral collaborations ("bottom-up projects") and as a partner and driver in international large-scale biology projects ("top-down projects"). Furthermore, technology development is a major topic in the GMC. Innovative techniques for primary and secondary screens are developed and implemented into the phenotyping pipelines (e.g., detection of volatile organic compounds, VOCs).
Mammalian Genome 08/2012; 23(9-10):611-22. · 2.89 Impact Factor
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Helmut Fuchs,
Sibylle Sabrautzki,
Hartwig Seedorf,
Birgit Rathkolb,
Jan Rozman,
Wolfgang Hans,
Ralf Schneider,
Matthias Klaften,
Sabine M Hölter,
Lore Becker,
Martina Klempt,
Ralf Elvert,
Wolfgang Wurst,
Thomas Klopstock,
Martin Klingenspor,
Eckhard Wolf, Valérie Gailus-Durner,
Martin Hrabě de Angelis
[show abstract]
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ABSTRACT: We analyzed two mutant mouse lines, ATE1 and ATE2, that carry point mutations in the enamelin gene which result in premature stop codons in exon 8 and exon 7, respectively. Both mutant lines show amelogenesis imperfecta. To establish the effect of mutations within the enamelin gene on different organs, we performed a systematic, standardized phenotypic analysis of both mutant lines in the German Mouse Clinic. In addition to the initially characterized tooth phenotype that is present in both mutant lines, we detected effects of enamelin mutations on bone and energy metabolism, as well as on clinical chemical and hematological parameters. These data raise the hypothesis that enamelin defects have pleiotropic effects on organs other than the teeth.
European Journal Of Oral Sciences 08/2012; 120(4):269-77. · 1.88 Impact Factor
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Robert Waltereit,
Uwe Leimer,
Oliver von Bohlen Und Halbach,
Jutta Panke,
Sabine M Hölter,
Lillian Garrett,
Karola Wittig,
Miriam Schneider,
Camie Schmitt,
Julia Calzada-Wack, [......],
Stefan Berger,
Kai Schönig,
Jerzy Adamski,
Thomas Klopstock,
Irene Esposito,
Wolfgang Wurst,
Martin Hrabe de Angelis,
Gudrun Rappold,
Thomas Wieland,
Dusan Bartsch
[show abstract]
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ABSTRACT: Mutations in the SRGAP3 gene residing on chromosome 3p25 have previously been associated with intellectual disability. Genome-wide association studies have also revealed SRGAP3, together with genes from the same cellular network, as risk genes for schizophrenia. SRGAP3 regulates cytoskeletal dynamics through the RHO protein RAC1. RHO proteins are known to be involved in cytoskeletal reorganization during brain development to control processes such as synaptic plasticity. To elucidate the importance of SRGAP3 in brain development, we generated Srgap3-knockout mice. Ten percent of these mice developed a hydrocephalus and died before adulthood. Surviving mice showed various neuroanatomical changes, including enlarged lateral ventricles, white matter tracts, and dendritic spines together with molecular changes, including an increased basal activity of RAC1. Srgap3(-/-) mice additionally exhibited a complex behavioral phenotype. Behavioral studies revealed an impaired spontaneous alternation and social behavior, while long-term memory was unchanged. The animals also had tics. Lower locomotor activity was observed in male Srgap3(-/-) only. Srgap3(-/-) mice showed increased methylphenidate stimulation in males and an impaired prepulse inhibition in females. Together, the results show neurodevelopmental aberration in Srgap3(-/-) mice, with many of the observed phenotypes matching several schizophrenia-related intermediate phenotypes. Mutations of SRGAP3 may thus contribute to various neurodevelopmental disorders. Waltereit, R., Leimer, U., von Bohlen und Halbach, O., Panke, J., Hölter, S. M., Garrett, L., Wittig, K., Schneider, M., Schmitt, C., Calzada-Wack, J., Neff, F., Becker, L., Prehn, C., Kutscherjawy, S., Endris, V., Bacon, C., Fuchs, H., Gailus-Durner, V., Berger, S., Schönig, K., Adamski, J., Klopstock, T., Esposito, I., Wurst, W., Hrabě de Angelis, M., Rappold, G., Wieland, T., Bartsch, D. Srgap3(-/-) mice present a neurodevelopmental disorder with schizophrenia-related intermediate phenotypes.
The FASEB Journal 07/2012; · 5.71 Impact Factor
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Martin Irmler,
Romina J G Gentier,
Frank J A Dennissen,
Holger Schulz,
Ines Bolle,
Sabine M Hölter,
Magdalena Kallnik,
Jing Jun Cheng,
Martin Klingenspor,
Jan Rozman,
Nicole Ehrhardt,
Denise J H P Hermes, Valérie Gailus-Durner,
Helmut Fuchs,
Martin Hrabě de Angelis,
Helmut E Meyer,
David A Hopkins,
Fred W Van Leeuwen,
Johannes Beckers
[show abstract]
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ABSTRACT: Aging and neurodegeneration are often accompanied by a functionally impaired ubiquitin-proteasome system (UPS). In tauopathies and polyglutamine diseases, a mutant form of ubiquitin B (UBB(+1)) accumulates in disease-specific aggregates. UBB(+1) mRNA is generated at low levels in vivo during transcription from the ubiquitin B locus by molecular misreading. The resulting mutant protein has been shown to inhibit proteasome function. To elucidate causative effects and neuropathological consequences of UBB(+1) accumulation, we used a UBB(+1) expressing transgenic mouse line that models UPS inhibition in neurons and exhibits behavioral phenotypes reminiscent of Alzheimer's disease (AD). In order to reveal affected organs and functions, young and aged UBB(+1) transgenic mice were comprehensively phenotyped for more than 240 parameters. This revealed unexpected changes in spontaneous breathing patterns and an altered response to hypoxic conditions. Our findings point to a central dysfunction of respiratory regulation in transgenic mice in comparison to wild-type littermate mice. Accordingly, UBB(+1) was strongly expressed in brainstem regions of transgenic mice controlling respiration. These regions included, e.g., the medial part of the nucleus of the tractus solitarius and the lateral subdivisions of the parabrachial nucleus. In addition, UBB(+1) was also strongly expressed in these anatomical structures of AD patients (Braak stage #6) and was not expressed in non-demented controls. We conclude that long-term UPS inhibition due to UBB(+1) expression causes central breathing dysfunction in a transgenic mouse model of AD. The UBB(+1) expression pattern in humans is consistent with the contribution of bronchopneumonia as a cause of death in AD patients.
Acta Neuropathologica 06/2012; 124(2):187-97. · 9.32 Impact Factor
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Maik Hüttemann,
Icksoo Lee,
Xiufeng Gao,
Petr Pecina,
Alena Pecinova,
Jenney Liu,
Siddhesh Aras,
Natascha Sommer,
Thomas H Sanderson,
Monica Tost, [......],
Thomas Klopstock,
Markus Ollert,
Eckhard Wolf,
Helmut Fuchs, Valérie Gailus-Durner,
Martin Hrabě de Angelis,
Norbert Weissmann,
Jeffrey W Doan,
David J P Bassett,
Lawrence I Grossman
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ABSTRACT: Cytochrome c oxidase (COX) is the terminal enzyme of the mitochondrial electron transport chain. The purpose of this study was to analyze the function of lung-specific cytochrome c oxidase subunit 4 isoform 2 (COX4i2) in vitro and in COX4i2-knockout mice in vivo. COX was isolated from cow lung and liver as control and functionally analyzed. COX4i2-knockout mice were generated and the effect of the gene knockout was determined, including COX activity, tissue energy levels, noninvasive and invasive lung function, and lung pathology. These studies were complemented by a comprehensive functional screen performed at the German Mouse Clinic (Neuherberg, Germany). We show that isolated cow lung COX containing COX4i2 is about twice as active (88 and 102% increased activity in the presence of allosteric activator ADP and inhibitor ATP, respectively) as liver COX, which lacks COX4i2. In COX4i2-knockout mice, lung COX activity and cellular ATP levels were significantly reduced (-50 and -29%, respectively). Knockout mice showed decreased airway responsiveness (60% reduced P(enh) and 58% reduced airway resistance upon challenge with 25 and 100 mg methacholine, respectively), and they developed a lung pathology deteriorating with age that included the appearance of Charcot-Leyden crystals. In addition, there was an interesting sex-specific phenotype, in which the knockout females showed reduced lean mass (-12%), reduced total oxygen consumption rate (-8%), improved glucose tolerance, and reduced grip force (-14%) compared to wild-type females. Our data suggest that high activity lung COX is a central determinant of airway function and is required for maximal airway responsiveness and healthy lung function. Since airway constriction requires energy, we propose a model in which reduced tissue ATP levels explain protection from airway hyperresponsiveness, i.e., absence of COX4i2 leads to reduced lung COX activity and ATP levels, which results in impaired airway constriction and thus reduced airway responsiveness; long-term lung pathology develops in the knockout mice due to impairment of energy-costly lung maintenance processes; and therefore, we propose mitochondrial oxidative phosphorylation as a novel target for the treatment of respiratory diseases, such as asthma.
The FASEB Journal 06/2012; 26(9):3916-30. · 5.71 Impact Factor
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Pawel K Olszewski,
Jan Rozman,
Josefin A Jacobsson,
Birgit Rathkolb,
Siv Strömberg,
Wolfgang Hans,
Anica Klockars,
Johan Alsiö,
Ulf Risérus,
Lore Becker, [......],
Robert Fredriksson,
Eckhard Wolf,
Thomas Klopstock,
Wolfgang Wurst,
Allen S Levine,
Claude Marcus,
Martin Hrabě de Angelis,
Martin Klingenspor,
Helgi B Schiöth,
Manfred W Kilimann
[show abstract]
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ABSTRACT: Neurobeachin (Nbea) regulates neuronal membrane protein trafficking and is required for the development and functioning of central and neuromuscular synapses. In homozygous knockout (KO) mice, Nbea deficiency causes perinatal death. Here, we report that heterozygous KO mice haploinsufficient for Nbea have higher body weight due to increased adipose tissue mass. In several feeding paradigms, heterozygous KO mice consumed more food than wild-type (WT) controls, and this consumption was primarily driven by calories rather than palatability. Expression analysis of feeding-related genes in the hypothalamus and brainstem with real-time PCR showed differential expression of a subset of neuropeptide or neuropeptide receptor mRNAs between WT and Nbea+/- mice in the sated state and in response to food deprivation, but not to feeding reward. In humans, we identified two intronic NBEA single-nucleotide polymorphisms (SNPs) that are significantly associated with body-mass index (BMI) in adult and juvenile cohorts. Overall, data obtained in mice and humans suggest that variation of Nbea abundance or activity critically affects body weight, presumably by influencing the activity of feeding-related neural circuits. Our study emphasizes the importance of neural mechanisms in body weight control and points out NBEA as a potential risk gene in human obesity.
PLoS Genetics 03/2012; 8(3):e1002568. · 8.69 Impact Factor
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Martin Klingenspor,
Siv Strömberg,
Eckhard Wolf,
Birgit Rathkolb,
Claude Marcus,
Sabine M Hölter,
Ralf Elvert,
Helgi B Schiöth,
Pawel K Olszewski,
Manfred W Kilimann, [......],
Josefin A Jacobsson,
Johan Alsiö,
Wolfgang Wurst,
Helmut Fuchs,
Ulf Risérus,
Wolfgang Hans,
Robert Fredriksson,
Allen S Levine,
Martin Hrabě de Angelis,
Lore Becker
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John F Staropoli,
Larissa Haliw,
Sunita Biswas,
Lillian Garrett,
Sabine M Hölter,
Lore Becker,
Sergej Skosyrski,
Patricia Da Silva-Buttkus,
Julia Calzada-Wack,
Frauke Neff, [......],
Evan Gale,
Vanessa C Wheeler,
Rose-Mary Boustany,
Diane E Brown,
Sylvie Breton,
Klaus Ruether, Valérie Gailus-Durner,
Helmut Fuchs,
Martin Hrabě de Angelis,
Susan L Cotman
[show abstract]
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ABSTRACT: Cln3(Δex7/8) mice harbor the most common genetic defect causing juvenile neuronal ceroid lipofuscinosis (JNCL), an autosomal recessive disease involving seizures, visual, motor and cognitive decline, and premature death. Here, to more thoroughly investigate the manifestations of the common JNCL mutation, we performed a broad phenotyping study of Cln3(Δex7/8) mice. Homozygous Cln3(Δex7/8) mice, congenic on a C57BL/6N background, displayed subtle deficits in sensory and motor tasks at 10-14 weeks of age. Homozygous Cln3(Δex7/8) mice also displayed electroretinographic changes reflecting cone function deficits past 5 months of age and a progressive decline of retinal post-receptoral function. Metabolic analysis revealed increases in rectal body temperature and minimum oxygen consumption in 12-13 week old homozygous Cln3(Δex7/8) mice, which were also seen to a lesser extent in heterozygous Cln3(Δex7/8) mice. Heart weight was slightly increased at 20 weeks of age, but no significant differences were observed in cardiac function in young adults. In a comprehensive blood analysis at 15-16 weeks of age, serum ferritin concentrations, mean corpuscular volume of red blood cells (MCV), and reticulocyte counts were reproducibly increased in homozygous Cln3(Δ) (ex7/8) mice, and male homozygotes had a relative T-cell deficiency, suggesting alterations in hematopoiesis. Finally, consistent with findings in JNCL patients, vacuolated peripheral blood lymphocytes were observed in homozygous Cln3(Δ) (ex7/8) neonates, and to a greater extent in older animals. Early onset, severe vacuolation in clear cells of the epididymis of male homozygous Cln3(Δ) (ex7/8) mice was also observed. These data highlight additional organ systems in which to study CLN3 function, and early phenotypes have been established in homozygous Cln3(Δ) (ex7/8) mice that merit further study for JNCL biomarker development.
PLoS ONE 01/2012; 7(6):e38310. · 4.09 Impact Factor
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H Fuchs,
S @bullet,
Neschen,
Vmd Wagner,
L @bullet,
Afonso,
C @bullet,
A Cohrs,
Frankó,
M @bullet, [......],
Markus Ollert,
Holger Schulz,
Tobias Stöger,
Wolfgang Wurst,
Ali Önder Yildirim,
Andreas Zimmer,
Eckhard Wolf,
Martin Klingenspor, Valérie Gailus-Durner,
Martin Hrabě De Angelis
01/2012: pages 85-106;
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Ingeborg Klymiuk,
Lukas Kenner,
Thure Adler,
Dirk H Busch,
Auke Boersma,
Martin Irmler, Valérie Gailus-Durner,
Helmut Fuchs,
Nicole Leitner,
Mathias Müller,
Ralf Kühn,
Michaela Schlederer,
Irina Treise,
Martin Hrabě de Angelis,
Johannes Beckers
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ABSTRACT: The mammalian Interferon induced transmembrane protein 1 (Ifitm1) gene was originally identified as a member of a gene family highly inducible by type I and type II interferons. Based on expression analyses, it was suggested to be required for normal primordial germ cell migration. The knockdown of Ifitm1 in mouse embryos provided evidence for a role in somitogenesis. We generated the first targeted knockin allele of the Ifitm1 gene to systematically reassess all inferred functions. Sperm motility and the fertility of male and female mutant mice are as in wild type littermates. Embryonic somites and the adult vertebral column appear normal in homozygous Ifitm1 knockout mice, demonstrating that Ifitm1 is not essential for normal segmentation of the paraxial mesoderm. Proportions of leucocyte subsets, including granulocytes, monocytes, B-cells, T-cells, NK-cells, and NKT-cells, are unchanged in mutant mice. Based on a normal immune response to Listeria monocytogenes infection, there is no evidence for a dysfunction in downstream IFNγ signaling in Ifitm1 mutant mice. Expression from the Ifitm1 locus from E8.5 to E14.5 is highly dynamic. In contrast, in adult mice, Ifitm1 expression is highly restricted and strong in the bronchial epithelium. Intriguingly, IFITM1 is highly overexpressed in tumor epithelia cells of human squamous cell carcinomas and in adenocarcinomas of NSCLC patients. These analyses underline the general importance of targeted in vivo studies for the functional annotation of the mammalian genome. The first comprehensive description of the Ifitm1 expression pattern provides a rational basis for the further examination of Ifitm1 gene functions. Based on our data, the fact that IFITM1 can function as a negative regulator of cell proliferation, and because the gene maps to chromosome band 11p15.5, previously associated with NSCLC, it is likely that IFITM1 in man has a key role in tumor formation.
PLoS ONE 01/2012; 7(10):e44609. · 4.09 Impact Factor
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Ingeborg Klymiuk,
Lukas Kenner,
Thure Adler,
Dirk H Busch,
Auke Boersma,
Martin Irmler,
Barbara Fridrich, Valérie Gailus-Durner,
Helmut Fuchs,
Nicole Leitner,
Mathias Müller,
Ralf Kühn,
Michaela Schlederer,
Irina Treise,
Martin Hrabě de Angelis,
Johannes Beckers
PLoS ONE 01/2012; 7(11). · 4.09 Impact Factor
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Benedetta Pozzi,
Stefania Amodio,
Caterina Lucano,
Anna Sciullo,
Simona Ronzoni,
Daniela Castelletti,
Thure Adler,
Irina Treise,
Ingrid Holmberg Betsholtz,
Birgit Rathkolb,
Dirk H Busch,
Eckhard Wolf,
Helmut Fuchs, Valérie Gailus-Durner,
Martin Hrabě de Angelis,
Christer Betsholtz,
Stefano Casola,
Pier Paolo Di Fiore,
Nina Offenhäuser
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ABSTRACT: Eps15 is an endocytic adaptor protein involved in clathrin and non-clathrin mediated endocytosis. In Caenorhabditis elegans and Drosophila melanogaster lack of Eps15 leads to defects in synaptic vesicle recycling and synapse formation. We generated Eps15-KO mice to investigate its function in mammals. Eps15-KO mice are born at the expected Mendelian ratio and are fertile. Using a large-scale phenotype screen covering more than 300 parameters correlated to human disease, we found that Eps15-KO mice did not show any sign of disease or neural deficits. Instead, altered blood parameters pointed to an immunological defect. By competitive bone marrow transplantation we demonstrated that Eps15-KO hematopoietic precursor cells were more efficient than the WT counterparts in repopulating B220(+) bone marrow cells, CD19(-) thymocytes and splenic marginal zone (MZ) B cells. Eps15-KO mice showed a 2-fold increase in MZ B cell numbers when compared with controls. Using reverse bone marrow transplantation, we found that Eps15 regulates MZ B cell numbers in a cell autonomous manner. FACS analysis showed that although MZ B cells were increased in Eps15-KO mice, transitional and pre-MZ B cell numbers were unaffected. The increase in MZ B cell numbers in Eps15 KO mice was not dependent on altered BCR signaling or Notch activity. In conclusion, in mammals, the endocytic adaptor protein Eps15 is a regulator of B-cell lymphopoiesis.
PLoS ONE 01/2012; 7(11):e50818. · 4.09 Impact Factor
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Marion Horsch,
Peter H Seeburg,
Thure Adler,
Juan Antonio Aguilar-Pimentel,
Lore Becker,
Julia Calzada-Wack,
Lilian Garrett,
Alexander Götz,
Wolfgang Hans,
Miyoko Higuchi, [......],
Martin Mempel,
Markus Ollert,
Holger Schulz,
Eckhard Wolf,
Wolfgang Wurst,
Andreas Zimmer, Valérie Gailus-Durner,
Helmut Fuchs,
Martin Hrabe de Angelis,
Johannes Beckers
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ABSTRACT: ADAR2, an RNA editing enzyme that converts specific adenosines to inosines in certain pre-mRNAs, often leading to amino acid substitutions in the encoded proteins, is mainly expressed in brain. Of all ADAR2-mediated edits, a single one in the pre-mRNA of the AMPA receptor subunit GluA2 is essential for survival. Hence, early postnatal death of mice lacking ADAR2 is averted when the critical edit is engineered into both GluA2 encoding Gria2 alleles. Adar2(-/-)/Gria2(R/R) mice display normal appearance and life span, but the general phenotypic effects of global lack of ADAR2 have remained unexplored. Here we have employed the Adar2(-/-)/Gria2(R/R) mouse line, and Gria2(R/R) mice as controls, to study the phenotypic consequences of loss of all ADAR2-mediated edits except the critical one in GluA2. Our extended phenotypic analysis covering ∼320 parameters identified significant changes related to absence of ADAR2 in behavior, hearing ability, allergy parameters and transcript profiles of brain.
Journal of Biological Chemistry 04/2011; 286(21):18614-22. · 4.77 Impact Factor
