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Chan WL, Steiner M, Witkos T, Egerer J, Busse B, Mizumoto S, Pestka JM, Zhang H, Hausser I, Khayal LA, Ott CE, Kolanczyk M, Willie B, Schinke T, Paganini C, Rossi A, Sugahara K, Amling M, Knaus P, Chan D, Lowe M, Mundlos S, Kornak U. Impaired proteoglycan glycosylation, elevated TGF-β signaling, and abnormal osteoblast differentiation as the basis for bone fragility in a mouse model for gerodermia osteodysplastica. PLoS Genet 2018; 14:e1007242. [PMID: 29561836 PMCID: PMC5880397 DOI: 10.1371/journal.pgen.1007242] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 04/02/2018] [Accepted: 02/05/2018] [Indexed: 02/02/2023] Open
Abstract
Gerodermia osteodysplastica (GO) is characterized by skin laxity and early-onset osteoporosis. GORAB, the responsible disease gene, encodes a small Golgi protein of poorly characterized function. To circumvent neonatal lethality of the GorabNull full knockout, Gorab was conditionally inactivated in mesenchymal progenitor cells (Prx1-cre), pre-osteoblasts (Runx2-cre), and late osteoblasts/osteocytes (Dmp1-cre), respectively. While in all three lines a reduction in trabecular bone density was evident, only GorabPrx1 and GorabRunx2 mutants showed dramatically thinned, porous cortical bone and spontaneous fractures. Collagen fibrils in the skin of GorabNull mutants and in bone of GorabPrx1 mutants were disorganized, which was also seen in a bone biopsy from a GO patient. Measurement of glycosaminoglycan contents revealed a reduction of dermatan sulfate levels in skin and cartilage from GorabNull mutants. In bone from GorabPrx1 mutants total glycosaminoglycan levels and the relative percentage of dermatan sulfate were both strongly diminished. Accordingly, the proteoglycans biglycan and decorin showed reduced glycanation. Also in cultured GORAB-deficient fibroblasts reduced decorin glycanation was evident. The Golgi compartment of these cells showed an accumulation of decorin, but reduced signals for dermatan sulfate. Moreover, we found elevated activation of TGF-β in GorabPrx1 bone tissue leading to enhanced downstream signalling, which was reproduced in GORAB-deficient fibroblasts. Our data suggest that the loss of Gorab primarily perturbs pre-osteoblasts. GO may be regarded as a congenital disorder of glycosylation affecting proteoglycan synthesis due to delayed transport and impaired posttranslational modification in the Golgi compartment. Gerodermia osteodysplastica (GO) is segmental progeroid disorder affecting connective tissues and bone, leading to extreme bone fragility. The cause are loss-of-function mutations in the Golgi protein GORAB, whose function has been only partially unravelled. Using several mouse models and patient-derived primary cells we elucidate that loss of Gorab elicits a defect in proteoglycan glycanation, which is associated with collagen disorganization in dermis and bone. We also found evidence for TGF-β upregulation and enhanced downstream signalling. If these changes occur in mesenchymal stem cells or early osteoblasts they impair osteoblast differentiation resulting in cortical thinning and spontaneous fractures. We thus match GO mechanistically with also phenotypically overlapping progeroid connective tissue disorders with glycanation defects.
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Affiliation(s)
- Wing Lee Chan
- Institut für Medizinische Genetik und Humangenetik, Charité –Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
- FG Development & Disease, Max-Planck-Institut fuer Molekulare Genetik, Berlin, Germany
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pok Fu Lam Road, Hong Kong
| | - Magdalena Steiner
- Institut für Medizinische Genetik und Humangenetik, Charité –Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
- Berlin School for Regenerative Therapies (BSRT), Charité –Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Tomasz Witkos
- School of Biology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Johannes Egerer
- Institut für Medizinische Genetik und Humangenetik, Charité –Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Björn Busse
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Shuji Mizumoto
- Lab. of Proteoglycan Signaling and Therapeutics, Faculty of Advanced Life Science, Graduate School of Life Science, Hokkaido University, Sapporo, Japan
| | - Jan M. Pestka
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Haikuo Zhang
- Institut für Medizinische Genetik und Humangenetik, Charité –Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Ingrid Hausser
- Institute of Pathology, University Clinic Heidelberg, Heidelberg, Germany
| | - Layal Abo Khayal
- Institut für Medizinische Genetik und Humangenetik, Charité –Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Claus-Eric Ott
- Institut für Medizinische Genetik und Humangenetik, Charité –Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Mateusz Kolanczyk
- FG Development & Disease, Max-Planck-Institut fuer Molekulare Genetik, Berlin, Germany
| | - Bettina Willie
- Julius Wolff Institute, Charité –Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Thorsten Schinke
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Chiara Paganini
- Department of Molecular Medicine, Unit of Biochemistry, University of Pavia, Pavia, Italy
| | - Antonio Rossi
- Department of Molecular Medicine, Unit of Biochemistry, University of Pavia, Pavia, Italy
| | - Kazuyuki Sugahara
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Michael Amling
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Petra Knaus
- Institute for Chemistry and Biochemistry, Freie Universität, Berlin, Germany
| | - Danny Chan
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pok Fu Lam Road, Hong Kong
- The University of Hong Kong—Shenzhen Institute of Research and Innovation (HKU- SIRI), Hi-Tech Industrial Park, Nanshan, Shenzhen, China
| | - Martin Lowe
- School of Biology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Stefan Mundlos
- Institut für Medizinische Genetik und Humangenetik, Charité –Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
- FG Development & Disease, Max-Planck-Institut fuer Molekulare Genetik, Berlin, Germany
- Berlin-Brandenburg Center for Regenerative Therapies, Charité –Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
- * E-mail: (UK); (SM)
| | - Uwe Kornak
- Institut für Medizinische Genetik und Humangenetik, Charité –Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
- FG Development & Disease, Max-Planck-Institut fuer Molekulare Genetik, Berlin, Germany
- Berlin-Brandenburg Center for Regenerative Therapies, Charité –Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
- * E-mail: (UK); (SM)
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Kobus K, Hartl D, Ott CE, Osswald M, Huebner A, von der Hagen M, Emmerich D, Kühnisch J, Morreau H, Hes FJ, Mautner VF, Harder A, Tinschert S, Mundlos S, Kolanczyk M. Double NF1 inactivation affects adrenocortical function in NF1Prx1 mice and a human patient. PLoS One 2015; 10:e0119030. [PMID: 25775093 PMCID: PMC4361563 DOI: 10.1371/journal.pone.0119030] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2014] [Accepted: 01/12/2015] [Indexed: 01/25/2023] Open
Abstract
Background Neurofibromatosis type I (NF1, MIM#162200) is a relatively frequent genetic condition, which predisposes to tumor formation. Apart from tumors, individuals with NF1 often exhibit endocrine abnormalities such as precocious puberty (2,5–5% of NF1 patients) and some cases of hypertension (16% of NF1 patients). Several cases of adrenal cortex adenomas have been described in NF1 individuals supporting the notion that neurofibromin might play a role in adrenal cortex homeostasis. However, no experimental data were available to prove this hypothesis. Materials and Methods We analysed Nf1Prx1 mice and one case of adrenal cortical hyperplasia in a NF1patient. Results In Nf1Prx1 mice Nf1 is inactivated in the developing limbs, head mesenchyme as well as in the adrenal gland cortex, but not the adrenal medulla or brain. We show that adrenal gland size is increased in NF1Prx1 mice. Nf1Prx1 female mice showed corticosterone and aldosterone overproduction. Molecular analysis of Nf1 deficient adrenals revealed deregulation of multiple proteins, including steroidogenic acute regulatory protein (StAR), a vital mitochondrial factor promoting transfer of cholesterol into steroid making mitochondria. This was associated with a marked upregulation of MAPK pathway and a female specific increase of cAMP concentration in murine adrenal lysates. Complementarily, we characterized a patient with neurofibromatosis type I with macronodular adrenal hyperplasia with ACTH-independent cortisol overproduction. Comparison of normal control tissue- and adrenal hyperplasia- derived genomic DNA revealed loss of heterozygosity (LOH) of the wild type NF1 allele, showing that biallelic NF1 gene inactivation occurred in the hyperplastic adrenal gland. Conclusions Our data suggest that biallelic loss of Nf1 induces autonomous adrenal hyper-activity. We conclude that Nf1 is involved in the regulation of adrenal cortex function in mice and humans.
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Affiliation(s)
- Karolina Kobus
- Institute for Medical Genetics and Human Genetics, Charité, Universitätsmedizin Berlin, Berlin, Germany
- Max Planck Institute for Molecular Genetics, FG Development & Disease, Berlin, Germany
- * E-mail: (MK); (KK)
| | - Daniela Hartl
- Institute for Medical Genetics and Human Genetics, Charité, Universitätsmedizin Berlin, Berlin, Germany
| | - Claus Eric Ott
- Max Planck Institute for Molecular Genetics, FG Development & Disease, Berlin, Germany
| | - Monika Osswald
- Max Planck Institute for Molecular Genetics, FG Development & Disease, Berlin, Germany
| | - Angela Huebner
- Klinik für Kinder- und Jugendmedizin, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Maja von der Hagen
- Abteilung Neuropädiatrie, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Denise Emmerich
- Max Planck Institute for Molecular Genetics, FG Development & Disease, Berlin, Germany
| | - Jirko Kühnisch
- Institute for Medical Genetics and Human Genetics, Charité, Universitätsmedizin Berlin, Berlin, Germany
- Max Planck Institute for Molecular Genetics, FG Development & Disease, Berlin, Germany
| | - Hans Morreau
- Department of Pathology, Leiden University Center, Albinusdreef 2, 2333ZA, Leiden, The Netherlands
| | - Frederik J. Hes
- Department of Clinical Genetics, Leiden University Center, Albinusdreef 2, 2333ZA, Leiden, The Netherlands
| | - Victor F. Mautner
- Department of Maxillofacial Surgery, University Hospital Eppendorf, Hamburg, Germany
| | - Anja Harder
- Institute of Neuropathology, University Hospital Münster, Münster, Germany
| | - Sigrid Tinschert
- Department of Medical Genetics, Molecular and Clinical Pharmacology, Medical University Innsbruck, Innsbruck, Austria
| | - Stefan Mundlos
- Institute for Medical Genetics and Human Genetics, Charité, Universitätsmedizin Berlin, Berlin, Germany
- Max Planck Institute for Molecular Genetics, FG Development & Disease, Berlin, Germany
- Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Berlin, Germany
| | - Mateusz Kolanczyk
- Institute for Medical Genetics and Human Genetics, Charité, Universitätsmedizin Berlin, Berlin, Germany
- Max Planck Institute for Molecular Genetics, FG Development & Disease, Berlin, Germany
- * E-mail: (MK); (KK)
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Kühnisch J, Seto J, Lange C, Stumpp S, Kobus K, Grohmann J, Elefteriou F, Fratzl P, Mundlos S, Kolanczyk M. Neurofibromin inactivation impairs osteocyte development in Nf1Prx1 and Nf1Col1 mouse models. Bone 2014; 66:155-62. [PMID: 24947449 DOI: 10.1016/j.bone.2014.06.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 06/06/2014] [Accepted: 06/09/2014] [Indexed: 12/18/2022]
Abstract
Neurofibromin has been identified as a critical regulator of osteoblast differentiation. Osteoblast specific inactivation of neurofibromin in mice results in a high bone mass phenotype and hyperosteoidosis. Here, we show that inactivation of the Nf1 gene also impairs osteocyte development. We analyzed cortical bone tissue in two conditional mouse models, Nf1Prx1 and Nf1Col1, for morphological and molecular effects. Backscattered electron microscopy revealed significantly enlarged osteocyte lacunae in Nf1Prx1 and Nf1Col1 mice (level E2: ctrl=1.90±0.52%, Nf1Prx1=3.40±0.95%; ctrl 1.60±0.47%, Nf1Col1 2.46±0.91%). Moreover, the osteocyte lacunae appeared misshaped in Nf1Prx1 and Nf1Col1 mice as indicated by increased Feret ratios. Strongest osteocyte and dendritic network disorganization was observed in proximity of muscle attachment sites in Nf1Prx1 humeri. In contrast to control cells, Nf1Prx1 osteocytes contained abundant cytosolic vacuoles and accumulated immature organic matrix within the perilacunar space, a phenotype reminiscent of the hyperosteoidosis shown Nf1 deficient mice. Cortical bone lysates further revealed approx. twofold upregulated MAPK signalling in osteocytes of Nf1Prx1 mice. This was associated with transcriptional downregulation of collagens and genes involved in mechanical sensing in Nf1Prx1 and Nf1Col1 bone tissue. In contrast, matrix gla protein (MGP), phosphate regulating endopeptidase homolog, X-linked (PHEX), and genes involved in lipid metabolism were upregulated. In line with previously described hyperactivation of Nf1 deficient osteoblasts, systemic plasma levels of the bone formation markers osteocalcin (OCN) and procollagen typ I N-propeptide (PINP) were approx. twofold increased in Nf1Prx1 mice. Histochemical and molecular analysis ascertained that osteocytes in Nf1Prx1 cortical bone were viable and did not undergo apoptosis or autophagy. We conclude that loss of neurofibromin is not only critical for osteoblasts but also hinders normal osteocyte development. These findings expand the effect of neurofibromin onto yet another cell type where it is likely involved in the regulation of mechanical sensing, bone matrix composition and mechanical resistance of bone tissue.
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Affiliation(s)
- Jirko Kühnisch
- Institute for Medical Genetics and Human Genetics, Charité, Universitätsmedizin Berlin, Berlin, Germany; FG Development & Disease, Max Planck Institute for Molecular Genetics, Berlin, Germany.
| | - Jong Seto
- Department of Biomaterials, Max Planck Institute for Colloids and Interfaces, Potsdam, Germany; Department of Chemistry, École Normale Superiéure, 24 rue Lhomond, Paris 75005, France
| | - Claudia Lange
- Department of Biomaterials, Max Planck Institute for Colloids and Interfaces, Potsdam, Germany; Institut für Physiologische Chemie, MTZ, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Sabine Stumpp
- Institute for Medical Genetics and Human Genetics, Charité, Universitätsmedizin Berlin, Berlin, Germany
| | - Karolina Kobus
- FG Development & Disease, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Julia Grohmann
- FG Development & Disease, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Florent Elefteriou
- Department of Medicine, Pharmacology and Cancer Biology, Center for Bone Biology, Vanderbilt University Medical Center, Nashville TN, USA
| | - Peter Fratzl
- Department of Biomaterials, Max Planck Institute for Colloids and Interfaces, Potsdam, Germany; Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Berlin, Germany
| | - Stefan Mundlos
- Institute for Medical Genetics and Human Genetics, Charité, Universitätsmedizin Berlin, Berlin, Germany; FG Development & Disease, Max Planck Institute for Molecular Genetics, Berlin, Germany; Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Berlin, Germany
| | - Mateusz Kolanczyk
- Institute for Medical Genetics and Human Genetics, Charité, Universitätsmedizin Berlin, Berlin, Germany; FG Development & Disease, Max Planck Institute for Molecular Genetics, Berlin, Germany.
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Kolanczyk M, Krawitz P, Hecht J, Hupalowska A, Miaczynska M, Marschner K, Schlack C, Emmerich D, Kobus K, Kornak U, Robinson PN, Plecko B, Grangl G, Uhrig S, Mundlos S, Horn D. Missense variant in CCDC22 causes X-linked recessive intellectual disability with features of Ritscher-Schinzel/3C syndrome. Eur J Hum Genet 2014; 23:633-8. [PMID: 24916641 DOI: 10.1038/ejhg.2014.109] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 04/11/2014] [Accepted: 04/16/2014] [Indexed: 01/03/2023] Open
Abstract
Ritscher-Schinzel syndrome (RSS)/3C (cranio-cerebro-cardiac) syndrome (OMIM#220210) is a rare and clinically heterogeneous developmental disorder characterized by intellectual disability, cerebellar brain malformations, congenital heart defects, and craniofacial abnormalities. A recent study of a Canadian cohort identified homozygous sequence variants in the KIAA0196 gene, which encodes the WASH complex subunit strumpellin, as a cause for a form of RSS/3C syndrome. We have searched for genetic causes of a phenotype similar to RSS/3C syndrome in an Austrian family with two affected sons. To search for disease-causing variants, whole-exome sequencing (WES) was performed on samples from two affected male children and their parents. Before WES, CGH array comparative genomic hybridization was applied. Validation of WES and segregation studies was done using routine Sanger sequencing. Exome sequencing detected a missense variant (c.1670A>G; p.(Tyr557Cys)) in exon 15 of the CCDC22 gene, which maps to chromosome Xp11.23. Western blots of immortalized lymphoblastoid cell lines (LCLs) from the affected individual showed decreased expression of CCDC22 and an increased expression of WASH1 but a normal expression of strumpellin and FAM21 in the patients cells. We identified a variant in CCDC22 gene as the cause of an X-linked phenotype similar to RSS/3C syndrome in the family described here. A hypomorphic variant in CCDC22 was previously reported in association with a familial case of syndromic X-linked intellectual disability, which shows phenotypic overlap with RSS/3C syndrome. Thus, different inactivating variants affecting CCDC22 are associated with a phenotype similar to RSS/3C syndrome.
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Affiliation(s)
- Mateusz Kolanczyk
- 1] Institute for Medical Genetics and Human Genetics, Charité-Universitätsmedizin Berlin, Berlin, Germany [2] Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Peter Krawitz
- Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Jochen Hecht
- Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Anna Hupalowska
- Laboratory of Cell Biology, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Marta Miaczynska
- Laboratory of Cell Biology, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Katrin Marschner
- Institute for Medical Genetics and Human Genetics, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Claire Schlack
- Institute for Medical Genetics and Human Genetics, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Denise Emmerich
- 1] Institute for Medical Genetics and Human Genetics, Charité-Universitätsmedizin Berlin, Berlin, Germany [2] Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Karolina Kobus
- Institute for Medical Genetics and Human Genetics, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Uwe Kornak
- Institute for Medical Genetics and Human Genetics, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Peter N Robinson
- Institute for Medical Genetics and Human Genetics, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Barbara Plecko
- Division of Child Neurology, University Children's Hospital Zurich, Zürich, Switzerland
| | - Gernot Grangl
- Department of Pediatrics, Medical University Graz, Graz, Austria
| | - Sabine Uhrig
- Institute of Human Genetics, Medical University of Graz, Graz, Austria
| | - Stefan Mundlos
- 1] Institute for Medical Genetics and Human Genetics, Charité-Universitätsmedizin Berlin, Berlin, Germany [2] Max Planck Institute for Molecular Genetics, Berlin, Germany [3] Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Denise Horn
- Institute for Medical Genetics and Human Genetics, Charité-Universitätsmedizin Berlin, Berlin, Germany
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Kühnisch J, Seto J, Lange C, Schrof S, Stumpp S, Kobus K, Grohmann J, Kossler N, Varga P, Osswald M, Emmerich D, Tinschert S, Thielemann F, Duda G, Seifert W, el Khassawna T, Stevenson DA, Elefteriou F, Kornak U, Raum K, Fratzl P, Mundlos S, Kolanczyk M. Multiscale, converging defects of macro-porosity, microstructure and matrix mineralization impact long bone fragility in NF1. PLoS One 2014; 9:e86115. [PMID: 24465906 PMCID: PMC3897656 DOI: 10.1371/journal.pone.0086115] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Accepted: 12/05/2013] [Indexed: 01/01/2023] Open
Abstract
Bone fragility due to osteopenia, osteoporosis or debilitating focal skeletal dysplasias is a frequent observation in the Mendelian disease Neurofibromatosis type 1 (NF1). To determine the mechanisms underlying bone fragility in NF1 we analyzed two conditional mouse models, Nf1Prx1 (limb knock-out) and Nf1Col1 (osteoblast specific knock-out), as well as cortical bone samples from individuals with NF1. We examined mouse bone tissue with micro-computed tomography, qualitative and quantitative histology, mechanical tensile analysis, small-angle X-ray scattering (SAXS), energy dispersive X-ray spectroscopy (EDX), and scanning acoustic microscopy (SAM). In cortical bone of Nf1Prx1 mice we detected ectopic blood vessels that were associated with diaphyseal mineralization defects. Defective mineral binding in the proximity of blood vessels was most likely due to impaired bone collagen formation, as these areas were completely devoid of acidic matrix proteins and contained thin collagen fibers. Additionally, we found significantly reduced mechanical strength of the bone material, which was partially caused by increased osteocyte volume. Consistent with these observations, bone samples from individuals with NF1 and tibial dysplasia showed increased osteocyte lacuna volume. Reduced mechanical properties were associated with diminished matrix stiffness, as determined by SAM. In line with these observations, bone tissue from individuals with NF1 and tibial dysplasia showed heterogeneous mineralization and reduced collagen fiber thickness and packaging. Collectively, the data indicate that bone fragility in NF1 tibial dysplasia is partly due to an increased osteocyte-related micro-porosity, hypomineralization, a generalized defect of organic matrix formation, exacerbated in the regions of tensional and bending force integration, and finally persistence of ectopic blood vessels associated with localized macro-porotic bone lesions.
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Affiliation(s)
- Jirko Kühnisch
- Institute for Medical Genetics and Human Genetics, Charité - Universitätsmedizin Berlin, Berlin, Germany
- FG Development & Disease, Max Planck Institute for Molecular Genetics, Berlin, Germany
- * E-mail: (JK); (MK)
| | - Jong Seto
- Department of Biomaterials, Max Planck Institute for Colloids and Interfaces, Potsdam, Germany
- Department of Chemistry, Universität Konstanz, Konstanz, Germany
| | - Claudia Lange
- Department of Biomaterials, Max Planck Institute for Colloids and Interfaces, Potsdam, Germany
- Institut für Physiologische Chemie, MTZ, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Susanne Schrof
- Julius Wolff Institute & Brandenburg School of Regenerative Therapies, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Sabine Stumpp
- Institute for Medical Genetics and Human Genetics, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Karolina Kobus
- FG Development & Disease, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Julia Grohmann
- FG Development & Disease, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Nadine Kossler
- FG Development & Disease, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Peter Varga
- Julius Wolff Institute & Brandenburg School of Regenerative Therapies, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Monika Osswald
- FG Development & Disease, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Denise Emmerich
- Institute for Medical Genetics and Human Genetics, Charité - Universitätsmedizin Berlin, Berlin, Germany
- FG Development & Disease, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Sigrid Tinschert
- Division für Humangenetik, Medizinische Universität Innsbruck, Innsbruck, Austria
- Institut für Klinische Genetik, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Falk Thielemann
- Klinik für Orthopädie, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Georg Duda
- Julius Wolff Institute & Brandenburg School of Regenerative Therapies, Charité - Universitätsmedizin Berlin, Berlin, Germany
- Berlin-Brandenburg Center for Regenerative Therapies, Berlin, Germany
| | - Wenke Seifert
- Institute for Vegetative Anatomy, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Thaqif el Khassawna
- Laboratory of Experimental Trauma Surgery Giessen, Justus-Liebig University Giessen, Giessen, Germany
| | - David A. Stevenson
- University of Utah, Department of Pediatrics, Division of Medical Genetics, Salt Lake City, Utah, United States of America
| | - Florent Elefteriou
- Department of Medicine, Pharmacology and Cancer Biology, Center for Bone Biology, Vanderbilt University - Medical Center, Nashville, Tennessee, United States of America
| | - Uwe Kornak
- Institute for Medical Genetics and Human Genetics, Charité - Universitätsmedizin Berlin, Berlin, Germany
- FG Development & Disease, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Kay Raum
- Julius Wolff Institute & Brandenburg School of Regenerative Therapies, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Peter Fratzl
- Department of Biomaterials, Max Planck Institute for Colloids and Interfaces, Potsdam, Germany
- Berlin-Brandenburg Center for Regenerative Therapies, Berlin, Germany
| | - Stefan Mundlos
- Institute for Medical Genetics and Human Genetics, Charité - Universitätsmedizin Berlin, Berlin, Germany
- FG Development & Disease, Max Planck Institute for Molecular Genetics, Berlin, Germany
- Berlin-Brandenburg Center for Regenerative Therapies, Berlin, Germany
| | - Mateusz Kolanczyk
- Institute for Medical Genetics and Human Genetics, Charité - Universitätsmedizin Berlin, Berlin, Germany
- FG Development & Disease, Max Planck Institute for Molecular Genetics, Berlin, Germany
- * E-mail: (JK); (MK)
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Sullivan K, El-Hoss J, Quinlan KGR, Deo N, Garton F, Seto JTC, Gdalevitch M, Turner N, Cooney GJ, Kolanczyk M, North KN, Little DG, Schindeler A. NF1 is a critical regulator of muscle development and metabolism. Hum Mol Genet 2013; 23:1250-9. [PMID: 24163128 DOI: 10.1093/hmg/ddt515] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
There is emerging evidence for reduced muscle function in children with neurofibromatosis type 1 (NF1). We have examined three murine models featuring NF1 deficiency in muscle to study the effect on muscle function as well as any underlying pathophysiology. The Nf1(+/-) mouse exhibited no differences in overall weight, lean tissue mass, fiber size, muscle weakness as measured by grip strength or muscle atrophy-recovery with limb disuse, although this model lacks many other characteristic features of the human disease. Next, muscle-specific knockout mice (Nf1muscle(-/-)) were generated and they exhibited a failure to thrive leading to neonatal lethality. Intramyocellular lipid accumulations were observed by electron microscopy and Oil Red O staining. More mature muscle specimens lacking Nf1 expression taken from the limb-specific Nf1Prx1(-/-) conditional knockout line showed a 10-fold increase in muscle triglyceride content. Enzyme assays revealed a significant increase in the activities of oxidative metabolism enzymes in the Nf1Prx1(-/-) mice. Western analyses showed increases in the expression of fatty acid synthase and the hormone leptin, as well as decreased expression of a number of fatty acid transporters in this mouse line. These data support the hypothesis that NF1 is essential for normal muscle function and survival and are the first to suggest a direct link between NF1 and mitochondrial fatty acid metabolism.
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Jamsheer A, Zemojtel T, Kolanczyk M, Stricker S, Hecht J, Krawitz P, Doelken SC, Glazar R, Socha M, Mundlos S. Whole exome sequencing identifiesFGF16nonsense mutations as the cause of X-linked recessive metacarpal 4/5 fusion. J Med Genet 2013; 50:579-84. [DOI: 10.1136/jmedgenet-2013-101659] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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El Khassawna T, Toben D, Kolanczyk M, Schmidt-Bleek K, Koennecke I, Schell H, Mundlos S, Duda GN. Deterioration of fracture healing in the mouse model of NF1 long bone dysplasia. Bone 2012; 51:651-60. [PMID: 22868293 DOI: 10.1016/j.bone.2012.07.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Revised: 06/01/2012] [Accepted: 07/13/2012] [Indexed: 01/20/2023]
Abstract
Neurofibromatosis type 1 (NF1) is an autosomal dominant genetic disease resulting from inactivating mutations in the gene encoding the protein neurofibromin. NF1 manifests as a heritable susceptibility to tumours of neural tissue mainly located in the skin (neurofibromas) and pigmented skin lesions. Besides these more common clinical manifestations, many NF1 patients (50%) have abnormalities of the skeleton. Long bones are often affected (usually the tibia) and the clinical signs range from bowing to spontaneous fractures and non-unions. Here we present the analysis of bone fracture healing in the Nf1(Prx1)-knock-out mouse, a model of NF1 long bone dysplasia. In line with previously reported cortical bone injury results, fracture healing was impaired in Nf1(Prx1) mice. We showed that the defective fracture healing in Nf1(Prx1) mice is characterized by diminished cartilaginous callus formation and a thickening of the periosteal bone. These changes are paralleled by fibrous tissue accumulation within the fracture site. We identify a population of fibrous tissue cells within the Nf1 deficient fracture as alpha-smooth muscle actin positive myofibroblasts. Additionally, histological and in-situ hybridization analysis reveal a direct contact of the fracture site with muscle fascia, suggesting a possible involvement of muscle derived cells in the fracture deterioration.
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Affiliation(s)
- T El Khassawna
- Julius Wolff Institute and Center for Musculoskeletal Surgery, Charite Universitätsmedizin Berlin, Germany.
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Lange C, Li C, Manjubala I, Wagermaier W, Kühnisch J, Kolanczyk M, Mundlos S, Knaus P, Fratzl P. Fetal and postnatal mouse bone tissue contains more calcium than is present in hydroxyapatite. J Struct Biol 2011; 176:159-67. [PMID: 21855638 DOI: 10.1016/j.jsb.2011.08.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Revised: 08/02/2011] [Accepted: 08/03/2011] [Indexed: 11/18/2022]
Abstract
It has been shown for developing enamel and zebrafish fin that hydroxyapatite (HA) is preceded by an amorphous precursor, motivating us to examine the mineral development in mammalian bone, particularly femur and tibia of fetal and young mice. Mineral particle thickness and arrangement were characterized by (synchrotron) small-angle X-ray scattering (SAXS) combined with wide-angle X-ray diffraction (WAXD) and X-ray fluorescence (XRF) analysis. Simultaneous measurements of the local calcium content and the HA content via XRF and WAXD, respectively, revealed the total calcium contained in HA crystals. Interestingly, bones of fetal as well as newborn mice contained a certain fraction of calcium which is not part of the HA crystals. Mineral deposition could be first detected in fetal tibia at day 16.5 by environmental scanning electron microscopy (ESEM). SAXS revealed a complete lack of orientation in the mineral particles at this stage, whereas 1day after birth particles were predominantly aligned parallel to the longitudinal bone axis, with the highest degree of alignment in the midshaft. Moreover, we found that mineral particle length increased with age as well as the thickness, while fetal particles were thicker but much shorter. In summary, this study revealed strong differences in size and orientation of the mineral particles between fetal and postnatal bone, with bulkier, randomly oriented particles at the fetal stage, and highly aligned, much longer particles after birth. Moreover, a part of the calcium seems to be present in other form than HA at all stages of development.
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Affiliation(s)
- C Lange
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, Research Campus Golm, 14476 Potsdam, Germany.
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10
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Kolanczyk M, Mautner V, Kossler N, Nguyen R, Kühnisch J, Zemojtel T, Jamsheer A, Wegener E, Thurisch B, Tinschert S, Holtkamp N, Park SJ, Birch P, Kendler D, Harder A, Mundlos S, Kluwe L. MIA is a potential biomarker for tumour load in neurofibromatosis type 1. BMC Med 2011; 9:82. [PMID: 21726432 PMCID: PMC3224593 DOI: 10.1186/1741-7015-9-82] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2011] [Accepted: 07/04/2011] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Neurofibromatosis type 1 (NF1) is a frequent genetic disease characterized by multiple benign tumours with increased risk for malignancy. There is currently no biomarker for tumour load in NF1 patients. METHODS In situ hybridization and quantitative real-time polymerase reaction were applied to investigate expression of cartilage-specific genes in mice bearing conditional inactivation of NF1 in the developing limbs. These mice do not develop tumours but recapitulate aspects of NF1 bone dysplasia, including deregulation of cartilage differentiation. It has been recently shown that NF1 tumours require for their growth the master regulator of cartilage differentiation SOX9. We thus hypothesized that some of the cartilage-specific genes deregulated in an Nf1Prx1 mouse model might prove to be relevant biomarkers of NF1 tumours. We tested this hypothesis by analyzing expression of the SOX9 target gene product melanoma-inhibitory activity/cd-rap (MIA) in tumour and serum samples of NF1 patients. RESULTS Increased expression of Mia was found in Nf1-deficient cartilage in mice. In humans, MIA was expressed in all NF1-related tumours and its serum levels were significantly higher in NF1 patients than in healthy controls. Among NF1 patients, MIA serum levels were significantly higher in those with plexiform neurofibromas and in those with large number of cutaneous (> 1,000) or subcutaneous (> 100) neurofibromas than in patients without such tumours. Most notably, MIA serum levels correlated significantly with internal tumour burden. CONCLUSIONS MIA is a potential serum biomarker of tumour load in NF1 patients which could be useful in following the disease course and monitoring the efficacy of therapies.
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Affiliation(s)
- Mateusz Kolanczyk
- Institute of Medical Genetics, Charité, Universitätsmedizin Berlin, Humboldt University, Augustenburger Platz 1, D-13353 Berlin, Germany.
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11
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Kossler N, Stricker S, Rödelsperger C, Robinson PN, Kim J, Dietrich C, Osswald M, Kühnisch J, Stevenson DA, Braun T, Mundlos S, Kolanczyk M. Neurofibromin (Nf1) is required for skeletal muscle development. Hum Mol Genet 2011; 20:2697-709. [PMID: 21478499 DOI: 10.1093/hmg/ddr149] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Neurofibromatosis type 1 (NF1) is a multi-system disease caused by mutations in the NF1 gene encoding a Ras-GAP protein, neurofibromin, which negatively regulates Ras signaling. Besides neuroectodermal malformations and tumors, the skeletal system is often affected (e.g. scoliosis and long bone dysplasia) demonstrating the importance of neurofibromin for development and maintenance of the musculoskeletal system. Here, we focus on the role of neurofibromin in skeletal muscle development. Nf1 gene inactivation in the early limb bud mesenchyme using Prx1-cre (Nf1(Prx1)) resulted in muscle dystrophy characterized by fibrosis, reduced number of muscle fibers and reduced muscle force. This was caused by an early defect in myogenesis affecting the terminal differentiation of myoblasts between E12.5 and E14.5. In parallel, the muscle connective tissue cells exhibited increased proliferation at E14.5 and an increase in the amount of connective tissue as early as E16.5. These changes were accompanied by excessive mitogen-activated protein kinase pathway activation. Satellite cells isolated from Nf1(Prx1) mice showed normal self-renewal, but their differentiation was impaired as indicated by diminished myotube formation. Our results demonstrate a requirement of neurofibromin for muscle formation and maintenance. This previously unrecognized function of neurofibromin may contribute to the musculoskeletal problems in NF1 patients.
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Affiliation(s)
- Nadine Kossler
- FG Development & Disease, Max Planck Institute for Molecular Genetics, Ihnestrasse 73, Berlin, Germany
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12
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Kolanczyk M, Pech M, Zemojtel T, Yamamoto H, Mikula I, Calvaruso MA, van den Brand M, Richter R, Fischer B, Ritz A, Kossler N, Thurisch B, Spoerle R, Smeitink J, Kornak U, Chan D, Vingron M, Martasek P, Lightowlers RN, Nijtmans L, Schuelke M, Nierhaus KH, Mundlos S. NOA1 is an essential GTPase required for mitochondrial protein synthesis. Mol Biol Cell 2010; 22:1-11. [PMID: 21118999 PMCID: PMC3016967 DOI: 10.1091/mbc.e10-07-0643] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Nitric oxide associated-1 (NOA1) is an evolutionarily conserved guanosine triphosphate binding protein that localizes predominantly to mitochondria in mammalian cells. Here we determine NOA1 function through generation of knock-out mice and in vitro assays. Nitric oxide associated-1 (NOA1) is an evolutionarily conserved guanosine triphosphate (GTP) binding protein that localizes predominantly to mitochondria in mammalian cells. On the basis of bioinformatic analysis, we predicted its possible involvement in ribosomal biogenesis, although this had not been supported by any experimental evidence. Here we determine NOA1 function through generation of knockout mice and in vitro assays. NOA1-deficient mice exhibit midgestation lethality associated with a severe developmental defect of the embryo and trophoblast. Primary embryonic fibroblasts isolated from NOA1 knockout embryos show deficient mitochondrial protein synthesis and a global defect of oxidative phosphorylation (OXPHOS). Additionally, Noa1–/– cells are impaired in staurosporine-induced apoptosis. The analysis of mitochondrial ribosomal subunits from Noa1–/– cells by sucrose gradient centrifugation and Western blotting showed anomalous sedimentation, consistent with a defect in mitochondrial ribosome assembly. Furthermore, in vitro experiments revealed that intrinsic NOA1 GTPase activity was stimulated by bacterial ribosomal constituents. Taken together, our data show that NOA1 is required for mitochondrial protein synthesis, likely due to its yet unidentified role in mitoribosomal biogenesis. Thus, NOA1 is required for such basal mitochondrial functions as adenosine triphosphate (ATP) synthesis and apoptosis.
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Affiliation(s)
- Mateusz Kolanczyk
- Development & Disease Group, Max Planck Institute for Molecular Genetics, 14195 Berlin, Germany.
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13
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Rödelsperger C, Guo G, Kolanczyk M, Pletschacher A, Köhler S, Bauer S, Schulz MH, Robinson PN. Integrative analysis of genomic, functional and protein interaction data predicts long-range enhancer-target gene interactions. Nucleic Acids Res 2010; 39:2492-502. [PMID: 21109530 PMCID: PMC3074119 DOI: 10.1093/nar/gkq1081] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Multicellular organismal development is controlled by a complex network of transcription factors, promoters and enhancers. Although reliable computational and experimental methods exist for enhancer detection, prediction of their target genes remains a major challenge. On the basis of available literature and ChIP-seq and ChIP-chip data for enhanceosome factor p300 and the transcriptional regulator Gli3, we found that genomic proximity and conserved synteny predict target genes with a relatively low recall of 12–27% within 2 Mb intervals centered at the enhancers. Here, we show that functional similarities between enhancer binding proteins and their transcriptional targets and proximity in the protein–protein interactome improve prediction of target genes. We used all four features to train random forest classifiers that predict target genes with a recall of 58% in 2 Mb intervals that may contain dozens of genes, representing a better than two-fold improvement over the performance of prediction based on single features alone. Genome-wide ChIP data is still relatively poorly understood, and it remains difficult to assign biological significance to binding events. Our study represents a first step in integrating various genomic features in order to elucidate the genomic network of long-range regulatory interactions.
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Affiliation(s)
- Christian Rödelsperger
- Berlin-Brandenburg Center for Regenerative Therapies, Charité-Universitätsmedizin Berlin, Max Planck Institute for Molecular Genetics, Berlin, Germany
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14
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Baasanjav S, Jamsheer A, Kolanczyk M, Horn D, Latos T, Hoffmann K, Latos-Bielenska A, Mundlos S. Osteopoikilosis and multiple exostoses caused by novel mutations in LEMD3 and EXT1 genes respectively--coincidence within one family. BMC Med Genet 2010; 11:110. [PMID: 20618940 PMCID: PMC2912259 DOI: 10.1186/1471-2350-11-110] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2010] [Accepted: 07/09/2010] [Indexed: 11/10/2022]
Abstract
BACKGROUND Osteopoikilosis is a rare autosomal dominant genetic disorder, characterised by the occurrence of the hyperostotic spots preferentially localized in the epiphyses and metaphyses of the long bones, and in the carpal and tarsal bones 1. Heterozygous LEMD3 gene mutations were shown to be the primary cause of the disease 2. Association of the primarily asymptomatic osteopokilosis with connective tissue nevi of the skin is categorized as Buschke-Ollendorff syndrome (BOS) 3. Additionally, osteopoikilosis can coincide with melorheostosis (MRO), a more severe bone disease characterised by the ectopic bone formation on the periosteal and endosteal surface of the long bones 456. However, not all MRO affected individuals carry germ-line LEMD3 mutations 7. Thus, the genetic cause of MRO remains unknown. Here we describe a familial case of osteopoikilosis in which a novel heterozygous LEMD3 mutation coincides with a novel mutation in EXT1, a gene involved in aetiology of multiple exostosis syndrome. The patients affected with both LEMD3 and EXT1 gene mutations displayed typical features of the osteopoikilosis. There were no additional skeletal manifestations detected however, various non-skeletal pathologies coincided in this group. METHODS We investigated LEMD3 and EXT1 in the three-generation family from Poland, with 5 patients affected with osteopoikilosis and one child affected with multiple exostoses. RESULTS We found a novel c.2203C > T (p.R735X) mutation in exon 9 of LEMD3, resulting in a premature stop codon at amino acid position 735. The mutation co-segregates with the osteopoikilosis phenotype and was not found in 200 ethnically matched controls. Another new substitution G > A was found in EXT1 gene at position 1732 (cDNA) in Exon 9 (p.A578T) in three out of five osteopoikilosis affected family members. Evolutionary conservation of the affected amino acid suggested possible functional relevance, however no additional skeletal manifestations were observed other then those specific for osteopoikilosis. Finally in one member of the family we found a splice site mutation in the EXT1 gene intron 5 (IVS5-2 A > G) resulting in the deletion of 9 bp of cDNA encoding three evolutionarily conserved amino acid residues. This child patient suffered from a severe form of exostoses, thus a causal relationship can be postulated. CONCLUSIONS We identified a new mutation in LEMD3 gene, accounting for the familial case of osteopoikilosis. In the same family we identified two novel EXT1 gene mutations. One of them A598T co-incided with the LEMD3 mutation. Co-incidence of LEMD3 and EXT1 gene mutations was not associated with a more severe skeletal phenotype in those patients.
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Affiliation(s)
- Sevjidmaa Baasanjav
- Institute of Medical Genetics, Charité Berlin, Humboldt University, Augustenburger Platz 1, 13353 Berlin, Germany
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Elefteriou F, Kolanczyk M, Schindeler A, Viskochil DH, Hock JM, Schorry EK, Crawford AH, Friedman JM, Little D, Peltonen J, Carey JC, Feldman D, Yu X, Armstrong L, Birch P, Kendler DL, Mundlos S, Yang FC, Agiostratidou G, Hunter-Schaedle K, Stevenson DA. Skeletal abnormalities in neurofibromatosis type 1: approaches to therapeutic options. Am J Med Genet A 2009; 149A:2327-38. [PMID: 19764036 DOI: 10.1002/ajmg.a.33045] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The skeleton is frequently affected in individuals with neurofibromatosis type 1, and some of these bone manifestations can result in significant morbidity. The natural history and pathogenesis of the skeletal abnormalities of this disorder are poorly understood and consequently therapeutic options for these manifestations are currently limited. The Children's Tumor Foundation convened an International Neurofibromatosis Type 1 Bone Abnormalities Consortium to address future directions for clinical trials in skeletal abnormalities associated with this disorder. This report reviews the clinical skeletal manifestations and available preclinical mouse models and summarizes key issues that present barriers to optimal clinical management of skeletal abnormalities in neurofibromatosis type 1. These concepts should help advance optimal clinical management of the skeletal abnormalities in this disease and address major difficulties encountered for the design of clinical trials.
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Affiliation(s)
- Florent Elefteriou
- Department of Medicine, Vanderbilt Center for Bone Biology, Vanderbilt University Medical Center, Nashville, Tennessee 37232-0575, USA.
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16
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Scheele JS, Kolanczyk M, Gantert M, Zemojtel T, Dorn A, Sykes DB, Sykes DP, Möbest DCC, Kamps MP, Räpple D, Duchniewicz M. The Spt-Ada-Gcn5-acetyltransferase complex interaction motif of E2a is essential for a subset of transcriptional and oncogenic properties of E2a-Pbx1. Leuk Lymphoma 2009; 50:816-28. [PMID: 19399691 DOI: 10.1080/10428190902836107] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The oncogene E2a-Pbx1 is formed by the t(1;19) translocation, which joins the N-terminal transactivation domain of E2a with the C-terminal homeodomain of PBX1. The goal of this work was to elucidate the mechanisms by which E2a-Pbx1 can lead to deregulated target gene expression. For reporter constructs it was shown that E2a-Pbx1 can activate transcription through homodimer elements (TGATTGAT) or through heterodimer elements with Hox proteins (e.g. TGATTAAT). We show a novel mechanism by which E2a-Pbx1 activates transcription of EF-9 using a promoter in intron 1 of the EF-9 gene, resulting in an aminoterminal truncated transcript. Our results indicate that the LDFS motif of E2a is essential for the transactivation of EF-9, but dispensable for transactivation of fibroblast growth factor 15. The E2a LDFS motif was also essential for proliferation of NIH3T3 fibroblasts but was dispensable for the E2a-Pbx1-induced differentiation arrest of myeloid progenitors.
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Affiliation(s)
- Jürgen S Scheele
- Department of Medicine I and Pharmacology I, University Hospital Freiburg, Freiburg, Germany.
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Jürgens AS, Kolanczyk M, Moebest DCC, Zemojtel T, Lichtenauer U, Duchniewicz M, Gantert MP, Hecht J, Hattenhorst U, Burdach S, Dorn A, Kamps MP, Beuschlein F, Räpple D, Scheele JS. PBX1 is dispensable for neural commitment of RA-treated murine ES cells. In Vitro Cell Dev Biol Anim 2009; 45:252-63. [PMID: 19148706 PMCID: PMC2758398 DOI: 10.1007/s11626-008-9162-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2008] [Accepted: 11/20/2008] [Indexed: 11/29/2022]
Abstract
Experimentation with PBX1 knockout mice has shown that PBX1 is necessary for early embryogenesis. Despite broad insight into PBX1 function, little is known about the underlying target gene regulation. Utilizing the Cre–loxP system, we targeted a functionally important part of the homeodomain of PBX1 through homozygous deletion of exon-6 and flanking intronic regions leading to exon 7 skipping in embryonic stem (ES) cells. We induced in vitro differentiation of wild-type and PBX1 mutant ES cells by aggregation and retinoic acid (RA) treatment and compared their profiles of gene expression at the ninth day post-reattachment to adhesive media. Our results indicate that PBX1 interactions with HOX proteins and DNA are dispensable for RA-induced ability of ES to express neural genes and point to a possible involvement of PBX1 in the regulation of imprinted genes.
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Affiliation(s)
- Anne S Jürgens
- Department of Medicine I, University of Freiburg Medical Center, Hugstetter Str. 55, 79106, Freiburg, Germany
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18
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Kolanczyk M, Kühnisch J, Kossler N, Osswald M, Stumpp S, Thurisch B, Kornak U, Mundlos S. Modelling neurofibromatosis type 1 tibial dysplasia and its treatment with lovastatin. BMC Med 2008; 6:21. [PMID: 18671844 PMCID: PMC2516519 DOI: 10.1186/1741-7015-6-21] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2008] [Accepted: 07/31/2008] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Bowing and/or pseudarthrosis of the tibia is a known severe complication of neurofibromatosis type 1 (NF1). Mice with conditionally inactivated neurofibromin (Nf1) in the developing limbs and cranium (Nf1Prx1) show bowing of the tibia caused by decreased bone mineralisation and increased bone vascularisation. However, in contrast to NF1 patients, spontaneous fractures do not occur in Nf1Prx1 mice probably due to the relatively low mechanical load. We studied bone healing in a cortical bone injury model in Nf1Prx1 mice as a model for NF1-associated bone disease. Taking advantage of this experimental model we explore effects of systemically applied lovastatin, a cholesterol-lowering drug, on the Nf1 deficient bone repair. METHODS Cortical injury was induced bilaterally in the tuberositas tibiae in Nf1Prx1 mutant mice and littermate controls according to a method described previously. Paraffin as well as methacrylate sections were analysed from each animal. We divided 24 sex-matched mutant mice into a lovastatin-treated and an untreated group. The lovastatin-treated mice received 0.15 mg activated lovastatin by daily gavage. The bone repair process was analysed at three consecutive time points post injury, using histological methods, micro computed tomography measurements and in situ hybridisation. At each experimental time point, three lovastatin-treated mutant mice, three untreated mutant mice and three untreated control mice were analysed. The animal group humanely killed on day 14 post injury was expanded to six treated and six untreated mutant mice as well as six control mice. RESULTS Bone injury repair is a complex process, which requires the concerted effort of numerous cell types. It is initiated by an inflammatory response, which stimulates fibroblasts from the surrounding connective tissue to proliferate and fill in the injury site with a provisional extracellular matrix. In parallel, mesenchymal progenitor cells from the periost are recruited into the injury site to become osteoblasts. In Nf1Prx1 mice bone repair is delayed and characterised by the excessive formation and the persistence of fibro-cartilaginous tissue and impaired extracellular matrix mineralisation. Correspondingly, expression of Runx2 is downregulated. High-dose systemic lovastatin treatment restores Runx2 expression and accelerates new bone formation, thus improving cortical bone repair in Nf1Prx1 tibia. The bone anabolic effects correlate with a reduction of the mitogen activated protein kinase pathway hyper-activation in Nf1-deficient cells. CONCLUSION Our data suggest the potential usefulness of lovastatin, a drug approved by the US Food and Drug Administration in 1987 for the treatment of hypercholesteraemia, in the treatment of Nf1-related fracture healing abnormalities. The experimental model presented here constitutes a valuable tool for the pre-clinical stage testing of candidate drugs, targeting Nf1-associated bone dysplasia.
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Affiliation(s)
- Mateusz Kolanczyk
- Max Planck Institute for Molecular Genetics, FG Development & Disease, Berlin, Germany.
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19
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Zemojtel T, Kolanczyk M, Kossler N, Stricker S, Lurz R, Mikula I, Duchniewicz M, Schuelke M, Ghafourifar P, Martasek P, Vingron M, Mundlos S. Corrigendum to “Mammalian mitochondrial nitric oxide synthase: Characterization of a novel candidate” [FEBS Lett. 580 (2006) 455-462]. FEBS Lett 2007. [DOI: 10.1016/j.febslet.2007.04.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Kolanczyk M, Kossler N, Kühnisch J, Lavitas L, Stricker S, Wilkening U, Manjubala I, Fratzl P, Spörle R, Herrmann BG, Parada LF, Kornak U, Mundlos S. Multiple roles for neurofibromin in skeletal development and growth. Hum Mol Genet 2007; 16:874-86. [PMID: 17317783 DOI: 10.1093/hmg/ddm032] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Neurofibromatosis type 1 (NF1) is a prevalent genetic disorder primarily characterized by the formation of neurofibromas, café-au-lait spots and freckling. Skeletal abnormalities such as short stature or bowing/pseudarthrosis of the tibia are relatively common. To investigate the role of the neurofibromin in skeletal development, we crossed Nf1flox mice with Prx1Cre mice to inactivate Nf1 in undifferentiated mesenchymal cells of the developing limbs. Similar to NF1 affected individuals, Nf1(Prx1) mice show bowing of the tibia and diminished growth. Tibial bowing is caused by decreased stability of the cortical bone due to a high degree of porosity, decreased stiffness and reduction in the mineral content as well as hyperosteoidosis. Accordingly, osteoblasts show an increase in proliferation and a decreased ability to differentiate and mineralize in vitro. The reduction in growth is due to lower proliferation rates and a differentiation defect of chondrocytes. Abnormal vascularization of skeletal tissues is likely to contribute to this pathology as it exerts a negative effect on cortical bone stability. Furthermore, Nf1 has an important role in the development of joints, as shown by fusion of the hip joints and other joint abnormalities, which are not observed in neurofibromatosis type I. Thus, neurofibromin has multiple essential roles in skeletal development and growth.
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Affiliation(s)
- Mateusz Kolanczyk
- FG Development and Disease, Max Planck Institute for Molecular Genetics, Berlin, Germany
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Lichtenauer UD, Duchniewicz M, Kolanczyk M, Hoeflich A, Hahner S, Else T, Bicknell AB, Zemojtel T, Stallings NR, Schulte DM, Kamps MP, Hammer GD, Scheele JS, Beuschlein F. Pre-B-cell transcription factor 1 and steroidogenic factor 1 synergistically regulate adrenocortical growth and steroidogenesis. Endocrinology 2007; 148:693-704. [PMID: 17082260 DOI: 10.1210/en.2006-0681] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A variety of transcription factors including Wilms tumor gene (Wt-1), steroidogenic factor 1 (Sf-1), dosage-sensitive sex reversal, adrenal hypoplasia congenita on the X-chromosome, Gene 1 (Dax-1), and pre-B-cell transcription factor 1 (Pbx1) have been defined as necessary for regular adrenocortical development. However, the role of Pbx1 for adrenal growth and function in the adult organism together with the molecular relationship between Pbx1 and these other transcription factors have not been characterized. We demonstrate that Pbx haploinsufficiency (Pbx1(+/-)) in mice is accompanied by a significant lower adrenal weight in adult animals compared with wild-type controls. Accordingly, baseline proliferating cell nuclear antigen levels are lower in Pbx1(+/-) mice, and unilateral adrenalectomy results in impaired contralateral compensatory adrenal growth, indicating a lower proliferative potential in the context of Pbx1 haploinsufficiency. In accordance with the key role of IGFs in adrenocortical proliferation and development, real-time RT-PCR demonstrates significant lower expression levels of the IGF-I receptor, and up-regulation of IGF binding protein-2. Functionally, Pbx1(+/-) mice display a blunted corticosterone response after ACTH stimulation coincident with lower adrenal expression of the ACTH receptor (melanocortin 2 receptor, Mc2-r). Mechanistically, in vitro studies reveal that Pbx1 and Sf-1 synergistically stimulates Mc2-r promoter activity. Moreover, Sf-1 directly activates the Pbx1 promoter activity in vitro and in vivo. Taken together, these studies provide evidence for a role of Pbx1 in the maintenance of a functional adrenal cortex mediated by synergistic actions of Pbx1 and Sf-1 in the transcriptional regulation of the critical effector of adrenocortical differentiation, the ACTH receptor.
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Affiliation(s)
- Urs D Lichtenauer
- Division of Endocrine Research, Department of Medicine Innenstadt, University Hospital Munich, Ziemssenstrasse 1, D-80336 Munich, Germany
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Zemojtel T, Fröhlich A, Palmieri MC, Kolanczyk M, Mikula I, Wyrwicz LS, Wanker EE, Mundlos S, Vingron M, Martasek P, Durner J. Plant nitric oxide synthase: a never-ending story? Trends Plant Sci 2006; 11:524-5; author reply 526-8. [PMID: 17030145 DOI: 10.1016/j.tplants.2006.09.008] [Citation(s) in RCA: 197] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2006] [Revised: 08/04/2006] [Accepted: 09/28/2006] [Indexed: 05/04/2023]
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Claus R, Fliegauf M, Stock M, Duque JA, Kolanczyk M, Lübbert M. Inhibitors of DNA methylation and histone deacetylation independently relieve AML1/ETO-mediated lysozyme repression. J Leukoc Biol 2006; 80:1462-72. [PMID: 17000900 DOI: 10.1189/jlb.0106005] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The human lysozyme (LZM) gene is highly methylated in LZM-nonexpressor immature myeloid and in nonmyeloid cells and unmethylated only in LZM-expressing cells. Extended methylation analyses of the CpG-poor 5' flanking region and of the exon 4 CpG island (both containing Alu elements) of the LZM gene were now performed. Marked demethylation was noted after treatment of AML1/ETO-positive Kasumi-1 cells with the DNA methyltransferase (DNMT) inhibitor 5-aza-2'-deoxycytidine (5-azaCdR), not associated with cellular differentiation. LZM mRNA in Kasumi-1, but not in several AML1/ETO-negative myeloid cell lines, was specifically and independently up-regulated upon treatment with 5-azaCdR and, to a lesser extent, with the histone deacetylase (HDAC) inhibitor trichostatin A (TSA). Increased chromatin accessibility within the 5' LZM gene was observed concomitantly with 5-azaCdR-induced demethylation. In contrast, TSA treatment had no effect on chromatin accessibility, but, as shown by chromatin immunoprecipitation, resulted in increased acetylation of histones H3 and H4. Repression of LZM transcription is mediated by conditional AML1/ETO expression in an inducible cell line model (U-937), and is reversed by siRNA "knock-down" of AML1/ETO in Kasumi-1 cells (Dunne et al., Oncogene 25: 2006). Antagonization of LZM repression following conditional expression of AML1/ETO was achieved by TSA. In conclusion, we demonstrate complex interactions between DNA methylation and histone modifications in mediating LZM repression, which implicate AML1/ETO as one component involved in local chromatin remodeling. Interestingly, inhibitors of DNMTs and HDACs independently relieve repression of this CpG-poor gene in AML1/ETO-positive cells.
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Affiliation(s)
- Rainer Claus
- Division Hematology/Oncology, University of Freiburg Medical Center, Hugstetter Str. 55, Freiburg D-79106, Germany
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Lichtenauer UD, Schulte D, Kolanczyk M, Höflich A, Hahner S, Scheele J, Beuschein F. Pbx-1 is mandatory for proper adrenocortical growth and steroidogenesis and interacts with the SF-1 pathway. Exp Clin Endocrinol Diabetes 2006. [DOI: 10.1055/s-2006-932845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Duchniewicz M, Zemojtel T, Kolanczyk M, Grossmann S, Scheele JS, Zwartkruis FJT. Rap1A-deficient T and B cells show impaired integrin-mediated cell adhesion. Mol Cell Biol 2006; 26:643-53. [PMID: 16382154 PMCID: PMC1346907 DOI: 10.1128/mcb.26.2.643-653.2006] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Studies in tissue culture cells have demonstrated a role for the Ras-like GTPase Rap1 in the regulation of integrin-mediated cell-matrix and cadherin-mediated cell-cell contacts. To analyze the function of Rap1 in vivo, we have disrupted the Rap1A gene by homologous recombination. Mice homozygous for the deletion allele are viable and fertile. However, primary hematopoietic cells isolated from spleen or thymus have a diminished adhesive capacity on ICAM and fibronectin substrates. In addition, polarization of T cells from Rap1-/- cells after CD3 stimulation was impaired compared to that of wild-type cells. Despite this, these defects did not result in hematopoietic or cell homing abnormalities. Although it is possible that the relatively mild phenotype is a consequence of functional complementation by the Rap1B gene, our genetic studies confirm a role for Rap1A in the regulation of integrins.
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Affiliation(s)
- Marlena Duchniewicz
- Department of Computational Molecular Biology, Max Planck Institute for Molecular Genetics, Ihnestrasse 73, D-14195 Berlin, Germany
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Zemojtel T, Kolanczyk M, Kossler N, Stricker S, Lurz R, Mikula I, Duchniewicz M, Schuelke M, Ghafourifar P, Martasek P, Vingron M, Mundlos S. Mammalian mitochondrial nitric oxide synthase: Characterization of a novel candidate. FEBS Lett 2005; 580:455-62. [PMID: 16380119 DOI: 10.1016/j.febslet.2005.12.038] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2005] [Revised: 12/05/2005] [Accepted: 12/13/2005] [Indexed: 02/07/2023]
Abstract
Recently a novel family of putative nitric oxide synthases, with AtNOS1, the plant member implicated in NO production, has been described. Here we present experimental evidence that a mammalian ortholog of AtNOS1 protein functions in the cellular context of mitochondria. The expression data suggest that a candidate for mammalian mitochondrial nitric oxide synthase contributes to multiple physiological processes during embryogenesis, which may include roles in liver haematopoesis and bone development.
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Affiliation(s)
- Tomasz Zemojtel
- Department of Computational Molecular Biology, Max Planck Institute for Molecular Genetics, Ihnestrasse 73, D-14195 Berlin, Germany.
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