1
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Rius R, Compton AG, Baker NL, Welch AE, Coman D, Kava MP, Minoche AE, Cowley MJ, Thorburn DR, Christodoulou J. Application of Genome Sequencing from Blood to Diagnose Mitochondrial Diseases. Genes (Basel) 2021; 12:genes12040607. [PMID: 33924034 PMCID: PMC8072654 DOI: 10.3390/genes12040607] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 04/16/2021] [Accepted: 04/17/2021] [Indexed: 12/23/2022] Open
Abstract
Mitochondrial diseases can be caused by pathogenic variants in nuclear or mitochondrial DNA-encoded genes that often lead to multisystemic symptoms and can have any mode of inheritance. Using a single test, Genome Sequencing (GS) can effectively identify variants in both genomes, but it has not yet been universally used as a first-line approach to diagnosing mitochondrial diseases due to related costs and challenges in data analysis. In this article, we report three patients with mitochondrial disease molecularly diagnosed through GS performed on DNA extracted from blood to demonstrate different diagnostic advantages of this technology, including the detection of a low-level heteroplasmic pathogenic variant, an intragenic nuclear DNA deletion, and a large mtDNA deletion. Current technical improvements and cost reductions are likely to lead to an expanded routine diagnostic usage of GS and of the complementary “Omic” technologies in mitochondrial diseases.
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Affiliation(s)
- Rocio Rius
- Murdoch Children’s Research Institute, Melbourne, VIC 3052, Australia; (R.R.); (A.G.C.); (N.L.B.) (A.E.W.); (D.R.T.)
- Department of Paediatrics, University of Melbourne, Melbourne, VIC 3052, Australia
| | - Alison G. Compton
- Murdoch Children’s Research Institute, Melbourne, VIC 3052, Australia; (R.R.); (A.G.C.); (N.L.B.) (A.E.W.); (D.R.T.)
- Department of Paediatrics, University of Melbourne, Melbourne, VIC 3052, Australia
| | - Naomi L. Baker
- Murdoch Children’s Research Institute, Melbourne, VIC 3052, Australia; (R.R.); (A.G.C.); (N.L.B.) (A.E.W.); (D.R.T.)
- Department of Paediatrics, University of Melbourne, Melbourne, VIC 3052, Australia
- Victorian Clinical Genetic Services, Melbourne, VIC 3052, Australia
| | - AnneMarie E. Welch
- Murdoch Children’s Research Institute, Melbourne, VIC 3052, Australia; (R.R.); (A.G.C.); (N.L.B.) (A.E.W.); (D.R.T.)
| | - David Coman
- Department of Metabolic Medicine, Queensland Children’s Hospital, Brisbane, QLD 4101, Australia;
- School of Clinical Medicine, University of Queensland, Brisbane, QLD 4072, Australia
- School of Medicine, Griffith University, Gold Coast, QLD 4222, Australia
| | - Maina P. Kava
- Department of Neurology, Perth Children’s Hospital, Perth, WA 6009, Australia;
- Department of Metabolic Medicine and Rheumatology, Perth Children’s Hospital, Perth, WA 6009, Australia
| | - Andre E. Minoche
- Kinghorn Centre for Clinical Genomics, Garvan Institute, University of New South Wales, Randwick, NSW 2010, Australia;
| | - Mark J. Cowley
- Precision Medicine Theme, Children’s Cancer Institute, Kensington, NSW 2750, Australia;
- School of Women’s and Children’s Health, University of New South Wales, Randwick, NSW 2031, Australia
| | - David R. Thorburn
- Murdoch Children’s Research Institute, Melbourne, VIC 3052, Australia; (R.R.); (A.G.C.); (N.L.B.) (A.E.W.); (D.R.T.)
- Department of Paediatrics, University of Melbourne, Melbourne, VIC 3052, Australia
- Victorian Clinical Genetic Services, Melbourne, VIC 3052, Australia
| | - John Christodoulou
- Murdoch Children’s Research Institute, Melbourne, VIC 3052, Australia; (R.R.); (A.G.C.); (N.L.B.) (A.E.W.); (D.R.T.)
- Department of Paediatrics, University of Melbourne, Melbourne, VIC 3052, Australia
- Victorian Clinical Genetic Services, Melbourne, VIC 3052, Australia
- Correspondence: ; Tel.: +61-39936-6353
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Tan TY, Gonzaga-Jauregui C, Bhoj EJ, Strauss KA, Brigatti K, Puffenberger E, Li D, Xie L, Das N, Skubas I, Deckelbaum RA, Hughes V, Brydges S, Hatsell S, Siao CJ, Dominguez MG, Economides A, Overton JD, Mayne V, Simm PJ, Jones BO, Eggers S, Le Guyader G, Pelluard F, Haack TB, Sturm M, Riess A, Waldmueller S, Hofbeck M, Steindl K, Joset P, Rauch A, Hakonarson H, Baker NL, Farlie PG. Monoallelic BMP2 Variants Predicted to Result in Haploinsufficiency Cause Craniofacial, Skeletal, and Cardiac Features Overlapping Those of 20p12 Deletions. Am J Hum Genet 2017; 101:985-994. [PMID: 29198724 DOI: 10.1016/j.ajhg.2017.10.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 10/11/2017] [Indexed: 12/25/2022] Open
Abstract
Bone morphogenetic protein 2 (BMP2) in chromosomal region 20p12 belongs to a gene superfamily encoding TGF-β-signaling proteins involved in bone and cartilage biology. Monoallelic deletions of 20p12 are variably associated with cleft palate, short stature, and developmental delay. Here, we report a cranioskeletal phenotype due to monoallelic truncating and frameshift BMP2 variants and deletions in 12 individuals from eight unrelated families that share features of short stature, a recognizable craniofacial gestalt, skeletal anomalies, and congenital heart disease. De novo occurrence and autosomal-dominant inheritance of variants, including paternal mosaicism in two affected sisters who inherited a BMP2 splice-altering variant, were observed across all reported families. Additionally, we observed similarity to the human phenotype of short stature and skeletal anomalies in a heterozygous Bmp2-knockout mouse model, suggesting that haploinsufficiency of BMP2 could be the primary phenotypic determinant in individuals with predicted truncating variants and deletions encompassing BMP2. These findings demonstrate the important role of BMP2 in human craniofacial, skeletal, and cardiac development and confirm that individuals heterozygous for BMP2 truncating sequence variants or deletions display a consistent distinct phenotype characterized by short stature and skeletal and cardiac anomalies without neurological deficits.
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Affiliation(s)
- Tiong Yang Tan
- Victorian Clinical Genetics Services, Melbourne, VIC 3052, Australia; Murdoch Children's Research Institute, Melbourne, VIC 3052, Australia; Department of Paediatrics, University of Melbourne, Melbourne, VIC 3052, Australia.
| | | | - Elizabeth J Bhoj
- Center for Applied Genomics, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA 19104-4399, USA
| | | | | | | | - Dong Li
- Center for Applied Genomics, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA 19104-4399, USA
| | - LiQin Xie
- Regeneron Pharmaceuticals Inc., Tarrytown, NY 10591, USA
| | - Nanditha Das
- Regeneron Pharmaceuticals Inc., Tarrytown, NY 10591, USA
| | - Ioanna Skubas
- Regeneron Pharmaceuticals Inc., Tarrytown, NY 10591, USA
| | | | | | | | - Sarah Hatsell
- Regeneron Pharmaceuticals Inc., Tarrytown, NY 10591, USA
| | - Chia-Jen Siao
- Regeneron Pharmaceuticals Inc., Tarrytown, NY 10591, USA
| | | | | | - John D Overton
- Regeneron Genetics Center, Regeneron Pharmaceuticals Inc., Tarrytown, NY 10591, USA
| | - Valerie Mayne
- Royal Children's Hospital, Parkville, Melbourne, VIC 3052, Australia
| | - Peter J Simm
- Murdoch Children's Research Institute, Melbourne, VIC 3052, Australia; Department of Paediatrics, University of Melbourne, Melbourne, VIC 3052, Australia; Royal Children's Hospital, Parkville, Melbourne, VIC 3052, Australia
| | - Bryn O Jones
- Murdoch Children's Research Institute, Melbourne, VIC 3052, Australia; Royal Children's Hospital, Parkville, Melbourne, VIC 3052, Australia
| | - Stefanie Eggers
- Murdoch Children's Research Institute, Melbourne, VIC 3052, Australia
| | - Gwenaël Le Guyader
- Department of Medical Genetics, Poitiers University Hospital, Poitiers 86021, France
| | - Fanny Pelluard
- Department of Pathology, Bordeaux University Hospital, Bordeaux 33076, France
| | - Tobias B Haack
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, 72076 Tuebingen, Germany
| | - Marc Sturm
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, 72076 Tuebingen, Germany
| | - Angelika Riess
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, 72076 Tuebingen, Germany
| | - Stephan Waldmueller
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, 72076 Tuebingen, Germany; Universitätsklinik für Kinder- und Jugendmedizin, Kinderheilkunde II Kardiologie Intensivmedizin Pulmologie, 72076 Tuebingen, Germany
| | - Michael Hofbeck
- Universitätsklinik für Kinder- und Jugendmedizin, Kinderheilkunde II Kardiologie Intensivmedizin Pulmologie, 72076 Tuebingen, Germany
| | - Katharina Steindl
- Institute of Medical Genetics, University of Zurich, 8952 Schlieren-Zurich, Switzerland
| | - Pascal Joset
- Institute of Medical Genetics, University of Zurich, 8952 Schlieren-Zurich, Switzerland
| | - Anita Rauch
- Institute of Medical Genetics, University of Zurich, 8952 Schlieren-Zurich, Switzerland
| | - Hakon Hakonarson
- Center for Applied Genomics, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA 19104-4399, USA
| | - Naomi L Baker
- Murdoch Children's Research Institute, Melbourne, VIC 3052, Australia; Department of Paediatrics, University of Melbourne, Melbourne, VIC 3052, Australia
| | - Peter G Farlie
- Murdoch Children's Research Institute, Melbourne, VIC 3052, Australia; Department of Paediatrics, University of Melbourne, Melbourne, VIC 3052, Australia
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Farlie PG, Baker NL, Yap P, Tan TY. Frontonasal Dysplasia: Towards an Understanding of Molecular and Developmental Aetiology. Mol Syndromol 2016; 7:312-321. [PMID: 27920634 DOI: 10.1159/000450533] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/10/2016] [Indexed: 01/09/2023] Open
Abstract
The complex anatomy of the skull and face arises from the requirement to support multiple sensory and structural functions. During embryonic development, the diverse component elements of the neuro- and viscerocranium must be generated independently and subsequently united in a manner that sustains and promotes the growth of the brain and sensory organs, while achieving a level of structural integrity necessary for the individual to become a free-living organism. While each of these individual craniofacial components is essential, the cranial and facial midline lies at a structural nexus that unites these disparately derived elements, fusing them into a whole. Defects of the craniofacial midline can have a profound impact on both form and function, manifesting in a diverse array of phenotypes and clinical entities that can be broadly defined as frontonasal dysplasias (FNDs). Recent advances in the identification of the genetic basis of FNDs along with the analysis of developmental mechanisms impacted by these mutations have dramatically altered our understanding of this complex group of conditions.
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Affiliation(s)
- Peter G Farlie
- Murdoch Childrens Research Institute, University of Melbourne, Parkville, Vic., Australia; Department of Paediatrics, University of Melbourne, Parkville, Vic., Australia
| | - Naomi L Baker
- Murdoch Childrens Research Institute, University of Melbourne, Parkville, Vic., Australia; Department of Paediatrics, University of Melbourne, Parkville, Vic., Australia
| | - Patrick Yap
- Victorian Clinical Genetics Service, Royal Children's Hospital, University of Melbourne, Parkville, Vic., Australia; Genetic Health Service New Zealand (Northern Hub), Auckland City Hospital, Auckland, New Zealand
| | - Tiong Y Tan
- Victorian Clinical Genetics Service, Royal Children's Hospital, University of Melbourne, Parkville, Vic., Australia; Department of Paediatrics, University of Melbourne, Parkville, Vic., Australia
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4
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Xu JX, Kilpatrick N, Baker NL, Penington A, Farlie PG, Tan TY. Clinical and Molecular Characterisation of Children with Pierre Robin Sequence and Additional Anomalies. Mol Syndromol 2016; 7:322-328. [PMID: 27920635 DOI: 10.1159/000449115] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/25/2016] [Indexed: 12/21/2022] Open
Abstract
Pierre Robin Sequence (PRS) is usually classified into syndromic and nonsyndromic groups, with a further subclassification of the nonsyndromic group into isolated PRS and PRS with additional anomalies (PRS-Plus). The aim of this research is to provide an accurate phenotypic characterisation of nonsyndromic PRS, specifically the PRS-Plus subgroup. We sought to examine the frequency of sequence variants in previously defined conserved noncoding elements (CNEs) in the putative enhancer region upstream of SOX9, the regulation of which has been associated with PRS phenotypes. We identified 141 children with nonsyndromic PRS at the Royal Children's Hospital, Melbourne from 1985 to 2012 using 2 databases. Clinical and demographic data were extracted by file review and children categorized as 'isolated PRS' or 'PRS-Plus'. A subset of children with PRS-Plus was selected for detailed phenotyping and DNA sequencing of the upstream SOX9 CNEs. We found 83 children with isolated PRS and 58 with PRS-Plus. The most common PRS-Plus malformations involved the musculoskeletal and ocular systems. The most common coexisting craniofacial malformation was choanal stenosis/atresia. We identified 10 children with a family history of PRS or cleft palate. We found a single nucleotide substitution in a putative GATA1-binding site in one patient, but it was inherited from his phenotypically unaffected mother. PRS-Plus represents a broad phenotypic spectrum with uncertain pathogenesis. Dysmorphology assessment by a clinical geneticist is recommended. SOX9 CNE sequence variants are rare in our cohort and are unlikely to play a significant role in the pathogenesis of PRS-Plus.
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Affiliation(s)
- Jessie X Xu
- Murdoch Childrens Research Institute, University of Melbourne, Melbourne, Vic., Australia; Department of Paediatrics, University of Melbourne, Melbourne, Vic., Australia
| | - Nicky Kilpatrick
- Murdoch Childrens Research Institute, University of Melbourne, Melbourne, Vic., Australia; Department of Paediatrics, University of Melbourne, Melbourne, Vic., Australia; Royal Children's Hospital, Melbourne, Vic., Australia
| | - Naomi L Baker
- Murdoch Childrens Research Institute, University of Melbourne, Melbourne, Vic., Australia
| | - Anthony Penington
- Murdoch Childrens Research Institute, University of Melbourne, Melbourne, Vic., Australia; Department of Paediatrics, University of Melbourne, Melbourne, Vic., Australia; Royal Children's Hospital, Melbourne, Vic., Australia
| | - Peter G Farlie
- Murdoch Childrens Research Institute, University of Melbourne, Melbourne, Vic., Australia; Department of Paediatrics, University of Melbourne, Melbourne, Vic., Australia
| | - Tiong Yang Tan
- Murdoch Childrens Research Institute, University of Melbourne, Melbourne, Vic., Australia; Department of Paediatrics, University of Melbourne, Melbourne, Vic., Australia; Royal Children's Hospital, Melbourne, Vic., Australia; Victorian Clinical Genetics Services, Melbourne, Vic., Australia
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5
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Price KL, DeSantis SM, Simpson AN, Tolliver BK, McRae-Clark AL, Saladin ME, Baker NL, Wagner MT, Brady KT. The impact of clinical and demographic variables on cognitive performance in methamphetamine-dependent individuals in rural South Carolina. Am J Addict 2011; 20:447-55. [PMID: 21838844 PMCID: PMC3603567 DOI: 10.1111/j.1521-0391.2011.00164.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [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] [Indexed: 11/28/2022] Open
Abstract
Inconsistencies in reports on methamphetamine (METH) associated cognitive dysfunction may be attributed, at least in part, to the diversity of study sample features (eg, clinical and demographic characteristics). The current study assessed cognitive function in a METH-dependent population from rural South Carolina, and the impact of demographic and clinical characteristics on performance. Seventy-one male (28.2%) and female (71.8%) METH-dependent subjects were administered a battery of neurocognitive tests including the Test of Memory Malingering (TOMM), Shipley Institute of Living Scale, Paced Auditory Serial Addition Test (PASAT), Symbol Digit Modalities Test (SDMT), Grooved Pegboard Test, California Verbal Learning Test (CVLT), and Wisconsin Card Sorting Test (WCST). Demographic and clinical characteristics (eg, gender, frequency of METH use) were examined as predictors of performance. Subjects scored significantly lower than expected on one test of attention and one of fine motor function, but performed adequately on all other tests. There were no predictors of performance on attention; however, more frequent METH use was associated with better performance for males and worse for females on fine motor skills. The METH-dependent individuals in this population exhibit very limited cognitive impairment. The marked differences in education, Intellectual Quotient (IQ), and gender in our sample when compared to the published literature may contribute to these findings. Characterization of the impact of clinical and/or demographic features on cognitive deficits could be important in guiding the development of treatment interventions.
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Affiliation(s)
- KL Price
- Division of Clinical Neuroscience, Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC 29403, USA.
| | - SM DeSantis
- Division of Clinical Neuroscience, Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC 29403, USA.
| | - AN Simpson
- Division of Clinical Neuroscience, Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC 29403, USA.
| | - BK Tolliver
- Division of Clinical Neuroscience, Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC 29403, USA.
| | - AL McRae-Clark
- Division of Clinical Neuroscience, Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC 29403, USA.
| | - ME Saladin
- Division of Clinical Neuroscience, Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC 29403, USA.
| | - NL Baker
- Division of Clinical Neuroscience, Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC 29403, USA.
| | - MT Wagner
- Division of Clinical Neuroscience, Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC 29403, USA.
| | - KT Brady
- Division of Clinical Neuroscience, Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC 29403, USA.
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Tooley LD, Zamurs LK, Beecher N, Baker NL, Peat RA, Adams NE, Bateman JF, North KN, Baldock C, Lamandé SR. Collagen VI microfibril formation is abolished by an {alpha}2(VI) von Willebrand factor type A domain mutation in a patient with Ullrich congenital muscular dystrophy. J Biol Chem 2010; 285:33567-33576. [PMID: 20729548 PMCID: PMC2963345 DOI: 10.1074/jbc.m110.152520] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2010] [Revised: 07/22/2010] [Indexed: 11/06/2022] Open
Abstract
Collagen VI is an extracellular protein that most often contains the three genetically distinct polypeptide chains, α1(VI), α2(VI), and α3(VI), although three recently identified chains, α4(VI), α5(VI), and α6(VI), may replace α3(VI) in some situations. Each chain has a triple helix flanked by N- and C-terminal globular domains that share homology with the von Willebrand factor type A (VWA) domains. During biosynthesis, the three chains come together to form triple helical monomers, which then assemble into dimers and tetramers. Tetramers are secreted from the cell and align end-to-end to form microfibrils. The precise molecular mechanisms responsible for assembly are unclear. Mutations in the three collagen VI genes can disrupt collagen VI biosynthesis and matrix organization and are the cause of the inherited disorders Bethlem myopathy and Ullrich congenital muscular dystrophy. We have identified a Ullrich congenital muscular dystrophy patient with compound heterozygous mutations in α2(VI). The first mutation causes skipping of exon 24, and the mRNA is degraded by nonsense-mediated decay. The second mutation is a two-amino acid deletion in the C1 VWA domain. Recombinant C1 domains containing the deletion are insoluble and retained intracellularly, indicating that the mutation has detrimental effects on domain folding and structure. Despite this, mutant α2(VI) chains retain the ability to associate into monomers, dimers, and tetramers. However, we show that secreted mutant tetramers containing structurally abnormal C1 VWA domains are unable to associate further into microfibrils, directly demonstrating the critical importance of a correctly folded α2(VI) C1 domain in microfibril formation.
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Affiliation(s)
- Leona D Tooley
- From the Murdoch Childrens Research Institute, Parkville, Victoria 3052, Australia; Departments of Paediatrics, Parkville, Victoria 3052, Australia
| | - Laura K Zamurs
- From the Murdoch Childrens Research Institute, Parkville, Victoria 3052, Australia
| | - Nicola Beecher
- Wellcome Trust Centre for Cell Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Naomi L Baker
- From the Murdoch Childrens Research Institute, Parkville, Victoria 3052, Australia
| | - Rachel A Peat
- Neurogenetics Research Unit, Children's Hospital at Westmead and Discipline of Paediatrics and Child Health, University of Sydney, Westmead, New South Wales 2145, Australia
| | - Naomi E Adams
- From the Murdoch Childrens Research Institute, Parkville, Victoria 3052, Australia
| | - John F Bateman
- From the Murdoch Childrens Research Institute, Parkville, Victoria 3052, Australia; Biochemistry and Molecular Biology, University of Melbourne, Royal Children's Hospital, Parkville, Victoria 3052, Australia
| | - Kathryn N North
- Neurogenetics Research Unit, Children's Hospital at Westmead and Discipline of Paediatrics and Child Health, University of Sydney, Westmead, New South Wales 2145, Australia
| | - Clair Baldock
- Wellcome Trust Centre for Cell Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Shireen R Lamandé
- From the Murdoch Childrens Research Institute, Parkville, Victoria 3052, Australia; Departments of Paediatrics, Parkville, Victoria 3052, Australia.
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Risteli M, Ruotsalainen H, Salo AM, Sormunen R, Sipilä L, Baker NL, Lamandé SR, Vimpari-Kauppinen L, Myllylä R. Reduction of lysyl hydroxylase 3 causes deleterious changes in the deposition and organization of extracellular matrix. J Biol Chem 2009; 284:28204-28211. [PMID: 19696018 DOI: 10.1074/jbc.m109.038190] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Lysyl hydroxylase 3 (LH3) is a multifunctional enzyme possessing lysyl hydroxylase, collagen galactosyltransferase, and glucosyltransferase (GGT) activities. We report here an important role for LH3 in the organization of the extracellular matrix (ECM) and cytoskeleton. Deposition of ECM was affected in heterozygous LH3 knock-out mouse embryonic fibroblasts (MEF(+/-)) and in skin fibroblasts collected from a member of a Finnish epidermolysis bullosa simplex (EBS) family known to be deficient in GGT activity. We show the GGT deficiency to be due to a transcriptional defect in one LH3 allele. The ECM abnormalities also lead to defects in the arrangement of the cytoskeleton in both cell lines. Ultrastructural abnormalities were observed in the skin of heterozygous LH3 knock-out mice indicating that even a moderate decrease in LH3 has deleterious consequences in vivo. The LH3 null allele in the EBS family member and the resulting abnormalities in the organization of the extracellular matrix, similar to those found in MEF(+/-), may explain the correlation between the severity of the phenotype and the decrease in GGT activity reported in this family.
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Affiliation(s)
- Maija Risteli
- Departments of Biochemistry, P.O. Box 3000, University of Oulu, FI-90014 Oulu, Finland
| | - Heli Ruotsalainen
- Departments of Biochemistry, P.O. Box 3000, University of Oulu, FI-90014 Oulu, Finland
| | - Antti M Salo
- Departments of Biochemistry, P.O. Box 3000, University of Oulu, FI-90014 Oulu, Finland
| | - Raija Sormunen
- Department of Pathology, Biocenter Oulu, P.O. Box 5000, University of Oulu, FI-90014 Oulu, Finland
| | - Laura Sipilä
- Departments of Biochemistry, P.O. Box 3000, University of Oulu, FI-90014 Oulu, Finland
| | - Naomi L Baker
- Murdoch Children's Research Institute and Department of Pediatrics, University of Melbourne, Royal Children's Hospital, Parkville, Victoria 3052, Australia
| | - Shireen R Lamandé
- Murdoch Children's Research Institute and Department of Pediatrics, University of Melbourne, Royal Children's Hospital, Parkville, Victoria 3052, Australia
| | | | - Raili Myllylä
- Departments of Biochemistry, P.O. Box 3000, University of Oulu, FI-90014 Oulu, Finland.
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8
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Tooley L, Baker NL, Pace RA, Zamurs L, Lamande SR. Collagen VI A-domain changes: Mutations or polymorphisms? Matrix Biol 2008. [DOI: 10.1016/j.matbio.2008.09.399] [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: 10/21/2022]
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9
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Baker NL, Pace RA, Tooley L, Zamurs L, Adams NE, Lamande SR. Collagen VI mutations: A review of 54 patients. Matrix Biol 2008. [DOI: 10.1016/j.matbio.2008.09.397] [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: 11/24/2022]
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10
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Pace RA, Peat RA, Baker NL, Zamurs L, Mörgelin M, Irving M, Adams NE, Bateman JF, Mowat D, Smith NJC, Lamont PJ, Moore SA, Mathews KD, North KN, Lamandé SR. Collagen VI glycine mutations: perturbed assembly and a spectrum of clinical severity. Ann Neurol 2008; 64:294-303. [PMID: 18825676 DOI: 10.1002/ana.21439] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE The collagen VI muscular dystrophies, Bethlem myopathy and Ullrich congenital muscular dystrophy, form a continuum of clinical phenotypes. Glycine mutations in the triple helix have been identified in both Bethlem and Ullrich congenital muscular dystrophy, but it is not known why they cause these different phenotypes. METHODS We studied eight new patients who presented with a spectrum of clinical severity, screened the three collagen VI messenger RNA for mutations, and examined collagen VI biosynthesis and the assembly pathway. RESULTS All eight patients had heterozygous glycine mutations toward the N-terminal end of the triple helix. The mutations produced two assembly phenotypes. In the first patient group, collagen VI dimers accumulated in the cell but not the medium, microfibril formation in the medium was moderately reduced, and the amount of collagen VI in the extracellular matrix was not significantly altered. The second group had more severe assembly defects: some secreted collagen VI tetramers were not disulfide bonded, microfibril formation in the medium was severely compromised, and collagen VI in the extracellular matrix was reduced. INTERPRETATION These data indicate that collagen VI glycine mutations impair the assembly pathway in different ways and disease severity correlates with the assembly abnormality. In mildly affected patients, normal amounts of collagen VI were deposited in the fibroblast matrix, whereas in patients with moderate-to-severe disability, assembly defects led to a reduced collagen VI fibroblast matrix. This study thus provides an explanation for how different glycine mutations produce a spectrum of clinical severity.
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Affiliation(s)
- Rishika A Pace
- Murdoch Childrens Research Institute and Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Victoria, Australia
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11
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Peat RA, Smith JM, Compton AG, Baker NL, Pace RA, Burkin DJ, Kaufman SJ, Lamandé SR, North KN. Diagnosis and etiology of congenital muscular dystrophy. Neurology 2008; 71:312-21. [PMID: 18160674 DOI: 10.1212/01.wnl.0000284605.27654.5a] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE We aimed to determine the frequency of all known forms of congenital muscular dystrophy (CMD) in a large Australasian cohort. METHODS We screened 101 patients with CMD with a combination of immunofluorescence, Western blotting, and DNA sequencing to identify disease-associated abnormalities in glycosylated alpha-dystroglycan, collagen VI, laminin alpha2, alpha7-integrin, and selenoprotein. RESULTS A total of 45% of the CMD cohort were assigned to an immunofluorescent subgroup based on their abnormal staining pattern. Abnormal staining for glycosylated alpha-dystroglycan was present in 25% of patients, and approximately half of these had reduced glycosylated alpha-dystroglycan by Western blot. Sequencing of the FKRP, fukutin, POMGnT1, and POMT1 genes in all patients with abnormal alpha-dystroglycan immunofluorescence identified mutations in one patient for each of these genes and two patients had mutations in POMT2. Twelve percent of patients had abnormalities in collagen VI immunofluorescence, and we identified disease-causing COL6 mutations in eight of nine patients in whom the genes were sequenced. Laminin alpha2 deficiency accounted for only 8% of CMD. alpha7-Integrin staining was absent in 12 of 45 patients studied, and ITGA7 gene mutations were excluded in all of these patients. CONCLUSIONS We define the distribution of different forms of congenital muscular dystrophy in a large cohort of mixed ethnicity and demonstrate the utility and limitations of current diagnostic techniques.
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Affiliation(s)
- R A Peat
- Institute for Neuromuscular Research, The Children's Hospital at Westmead, Sydney, NSW, Australia
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12
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Tan JT, Kremer F, Freddi S, Bell KM, Baker NL, Lamandé SR, Bateman JF. Competency for nonsense-mediated reduction in collagen X mRNA is specified by the 3' UTR and corresponds to the position of mutations in Schmid metaphyseal chondrodysplasia. Am J Hum Genet 2008; 82:786-93. [PMID: 18304492 DOI: 10.1016/j.ajhg.2008.01.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2007] [Revised: 12/10/2007] [Accepted: 01/07/2008] [Indexed: 12/31/2022] Open
Abstract
Nonsense-mediated decay (NMD) is a eukaryotic cellular RNA surveillance and quality-control mechanism that degrades mRNA containing premature stop codons (nonsense mutations) that otherwise may exert a deleterious effect by the production of dysfunctional truncated proteins. Collagen X (COL10A1) nonsense mutations in Schmid-type metaphyseal chondrodysplasia are localized in a region toward the 3' end of the last exon (exon 3) and result in mRNA decay, in contrast to most other genes in which terminal-exon nonsense mutations are resistant to NMD. We introduce nonsense mutations into the mouse Col10a1 gene and express these in a hypertrophic-chondrocyte cell line to explore the mechanism of last-exon mRNA decay of Col10a1 and demonstrate that mRNA decay is spatially restricted to mutations occurring in a 3' region of the exon 3 coding sequence; this region corresponds to where human mutations have been described. This localization of mRNA-decay competency suggested that a downstream region, such as the 3' UTR, may play a role in specifying decay of mutant Col10a1 mRNA containing nonsense mutations. We found that deleting any of the three conserved sequence regions within the 3' UTR (region I, 23 bp; region II, 170 bp; and region III, 76 bp) prevented mutant mRNA decay, but a smaller 13 bp deletion within region III was permissive for decay. These data suggest that the 3' UTR participates in collagen X last-exon mRNA decay and that overall 3' UTR configuration, rather than specific linear-sequence motifs, may be important in specifying decay of Col10a1 mRNA containing nonsense mutations.
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Baker NL, Mörgelin M, Pace RA, Peat RA, Adams NE, Gardner RJM, Rowland LP, Miller G, De Jonghe P, Ceulemans B, Hannibal MC, Edwards M, Thompson EM, Jacobson R, Quinlivan RCM, Aftimos S, Kornberg AJ, North KN, Bateman JF, Lamandé SR. Molecular consequences of dominant Bethlem myopathy collagen VI mutations. Ann Neurol 2007; 62:390-405. [PMID: 17886299 DOI: 10.1002/ana.21213] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
OBJECTIVE Dominant mutations in the three collagen VI genes cause Bethlem myopathy, a disorder characterized by proximal muscle weakness and commonly contractures of the fingers, wrists, and ankles. Although more than 20 different dominant mutations have been identified in Bethlem myopathy patients, the biosynthetic consequences of only a subset of these have been studied, and in many cases, the pathogenic mechanisms remain unknown. METHODS We have screened fourteen Bethlem myopathy patients for collagen VI mutations and performed detailed analyses of collagen VI biosynthesis and intracellular and extracellular assembly. RESULTS Collagen VI abnormalities were identified in eight patients. One patient produced around half the normal amount of alpha1(VI) messenger RNA and reduced amounts of collagen VI protein. Two patients had a previously reported mutation causing skipping of COL6A1 exon 14, and three patients had novel mutations leading to in-frame deletions toward the N-terminal end of the triple-helical domain. These mutations have different and complex effects on collagen VI intracellular and extracellular assembly. Two patients had single amino acid substitutions in the A-domains of COL6A2 and COL6A3. Collagen VI intracellular and extracellular assembly was normal in one of these patients. INTERPRETATION The key to dissecting the pathogenic mechanisms of collagen VI mutations lies in detailed analysis of collagen VI biosynthesis and assembly. The majority of mutations result in secretion and deposition of structurally abnormal collagen VI. However, one A-domain mutation had no detectable effect on assembly, suggesting that it acts by compromising collagen VI interactions in the extracellular matrix of muscle.
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Affiliation(s)
- Naomi L Baker
- Murdoch Childrens Research Institute and Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Parkville, Victoria, Australia
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14
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Sipilä L, Ruotsalainen H, Sormunen R, Baker NL, Lamandé SR, Vapola M, Wang C, Sado Y, Aszodi A, Myllylä R. Secretion and assembly of type IV and VI collagens depend on glycosylation of hydroxylysines. J Biol Chem 2007; 282:33381-33388. [PMID: 17873278 DOI: 10.1074/jbc.m704198200] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [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: 11/06/2022] Open
Abstract
Most lysines in type IV and VI collagens are hydroxylated and glycosylated, but the functions of these unique galactosylhydroxylysyl and glucosylgalactosylhydroxylysyl residues are poorly understood. The formation of glycosylated hydroxylysines is catalyzed by multifunctional lysyl hydroxylase 3 (LH3) in vivo, and we have used LH3-manipulated mice and cells as models to study the function of these carbohydrates. These hydroxylysine-linked carbohydrates were shown recently to be indispensable for the formation of basement membranes (Ruotsalainen, H., Sipilä, L., Vapola, M., Sormunen, R., Salo, A. M., Uitto, L., Mercer, D. K., Robins, S. P., Risteli, M., Aszodi, A., Fässler, R., and Myllylä, R. (2006) J. Cell Sci. 119, 625-635). Analysis of LH3 knock-out embryos and cells in this work indicated that loss of glycosylated hydroxylysines prevents the intracellular tetramerization of type VI collagen and leads to impaired secretion of type IV and VI collagens. Mice lacking the LH activity of LH3 produced slightly underglycosylated type IV and VI collagens with abnormal distribution. The altered distribution and aggregation of type VI collagen led to similar ultrastructural alterations in muscle to those detected in collagen VI knockout and some Ullrich congenital muscular dystrophy patients. Our results provide new information about the function of hydroxylysine-linked carbohydrates of collagens, indicating that they play an important role in the secretion, assembly, and distribution of highly glycosylated collagen types.
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Affiliation(s)
- Laura Sipilä
- Department of Biocenter Oulu, University of Oulu, Oulu, FI-90014, Finland; Department of Biochemistry, University of Oulu, Oulu, FI-90014, Finland
| | - Heli Ruotsalainen
- Department of Biocenter Oulu, University of Oulu, Oulu, FI-90014, Finland; Department of Biochemistry, University of Oulu, Oulu, FI-90014, Finland
| | - Raija Sormunen
- Department of Biocenter Oulu, University of Oulu, Oulu, FI-90014, Finland; Department of Pathology, University of Oulu, FI-90014 Oulu, Finland
| | - Naomi L Baker
- Murdoch Childrens Research Institute and Department of Paediatrics, Royal Childrenʼns Hospital, University of Melbourne, Parkville, Victoria 3052, Australia
| | - Shireen R Lamandé
- Murdoch Childrens Research Institute and Department of Paediatrics, Royal Childrenʼns Hospital, University of Melbourne, Parkville, Victoria 3052, Australia
| | - Miia Vapola
- Department of Biocenter Oulu, University of Oulu, Oulu, FI-90014, Finland; Department of Biochemistry, University of Oulu, Oulu, FI-90014, Finland
| | - Chunguang Wang
- Department of Biocenter Oulu, University of Oulu, Oulu, FI-90014, Finland; Department of Biochemistry, University of Oulu, Oulu, FI-90014, Finland
| | - Yoshikazu Sado
- Division of Immunology, Shigei Medical Research Institute, 2117 Yamada, Okayama 701-0202, Japan
| | - Attila Aszodi
- Department of Molecular Medicine, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Raili Myllylä
- Department of Biocenter Oulu, University of Oulu, Oulu, FI-90014, Finland; Department of Biochemistry, University of Oulu, Oulu, FI-90014, Finland.
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Peat RA, Baker NL, Jones KJ, North KN, Lamandé SR. Variable penetrance of COL6A1 null mutations: implications for prenatal diagnosis and genetic counselling in Ullrich congenital muscular dystrophy families. Neuromuscul Disord 2007; 17:547-57. [PMID: 17537636 DOI: 10.1016/j.nmd.2007.03.017] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2006] [Revised: 03/16/2007] [Accepted: 03/27/2007] [Indexed: 12/28/2022]
Abstract
Collagen VI mutations cause mild Bethlem myopathy and severe, progressive Ullrich congenital muscular dystrophy (UCMD). We identified a novel homozygous COL6A1 premature termination mutation in a UCMD patient that causes nonsense-mediated mRNA decay. Collagen VI microfibrils cannot be detected in muscle or fibroblasts. The parents are heterozygous carriers of the mutation and their fibroblasts produce reduced amounts of collagen VI. The molecular findings in the parents are analogous to those reported for a heterozygous COL6A1 premature termination mutation that causes Bethlem myopathy. However, the parents of our UCMD proband are clinically normal. The proband's brother, also a carrier, has clinical features consistent with a mild collagen VI phenotype. Following a request for prenatal diagnosis in a subsequent pregnancy we found the fetus was a heterozygous carrier indicating that it would not be affected with severe UCMD. COL6A1 premature termination mutations exhibit variable penetrance necessitating a cautious approach to genetic counselling.
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Affiliation(s)
- Rachel A Peat
- The Neurogenetics Research Unit, Children's Hospital, Westmead, Sydney, Australia
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16
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Baker NL, Mörgelin M, Peat R, Goemans N, North KN, Bateman JF, Lamandé SR. Dominant collagen VI mutations are a common cause of Ullrich congenital muscular dystrophy. Hum Mol Genet 2004; 14:279-93. [PMID: 15563506 DOI: 10.1093/hmg/ddi025] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Mutations in the three collagen VI genes COL6A1, COL6A2 and COL6A3 cause Bethlem myopathy and Ullrich congenital muscular dystrophy (UCMD). UCMD, a severe disorder characterized by congenital muscle weakness, proximal joint contractures and marked distal joint hyperextensibility, has been considered a recessive condition, and homozygous or compound heterozygous mutations have been defined in COL6A2 and COL6A3. In contrast, the milder disorder Bethlem myopathy shows clear dominant inheritance and is caused by heterozygous mutations in COL6A1, COL6A2 and COL6A3. This model, where dominant mutations cause mild Bethlem myopathy and recessive mutations cause severe UCMD was recently challenged when a patient with UCMD was shown to have a heterozygous in-frame deletion in COL6A1. We have studied five patients with a clinical diagnosis of UCMD. Three patients had heterozygous in-frame deletions in the N-terminal region of the triple helical domain, one in the alpha1(VI) chain, one in alpha2(VI) and one in alpha3(VI). Collagen VI protein biosynthesis and assembly studies showed that these mutations act in a dominant negative fashion and result in severe collagen VI matrix deficiencies. One patient had recessive amino acid changes in the C2 subdomain of alpha2(VI), which prevented collagen VI assembly. No collagen VI mutations were found in the fifth patient. These data demonstrate that rather than being a rare cause of UCMD, dominant mutations are common in UCMD, now accounting for four of the 14 published cases. Mutation detection in this disorder remains critical for accurate genetic counseling of patients and their families.
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Affiliation(s)
- Naomi L Baker
- Cell and Matrix Biology, Murdoch Childrens Research Institute and Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Parkville, Victoria, Australia
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17
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Russo VC, Kobayashi K, Najdovska S, Baker NL, Werther GA. Neuronal protection from glucose deprivation via modulation of glucose transport and inhibition of apoptosis: a role for the insulin-like growth factor system. Brain Res 2004; 1009:40-53. [PMID: 15120582 DOI: 10.1016/j.brainres.2004.02.042] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/26/2004] [Indexed: 11/23/2022]
Abstract
Glucose is the brain's major energy source; therefore, loss of neuronal cells is a potential consequence of hypoglycaemia. Since apoptosis is a major mechanism of neuronal loss following a range of insults, we explored potent anti-apoptotic systems (IGF-I and bcl-2) as means of enhancing neuronal survival in the face of glucose deprivation. Human neuroblastoma cells (SH-SY5Y, SHEP and SHEP-bcl-2) were exposed to low glucose as a model of glucopenia-induced neuronal damage. Administration of IGF-I and/or over-expression of the survival gene bcl-2 were exploited to attempt to limit neuronal loss. Neuronal survival mechanisms and interactions between these systems were investigated. Low glucose (0.25-2.5 mM) adversely affected cell growth and survival; however, IGF-I ameliorated these outcomes. Over-expression of bcl-2 blunted low glucose-induced apoptosis and up-regulated IGF-I receptor, with the effect of IGF-I addition being negligible on apoptosis, while significantly enhancing mitochondrial activity. In SH-SY5Y cells, IGF-I significantly changed >two-fold mRNA levels of the apoptosis-related genes gadd45, fas, iNOS, NFkB, TRAIL, without further affecting bcl-2 expression. In low glucose, IGF-I acutely enhanced glucose transport and translocation of GLUT1 protein to the cell membrane. GLUT1 mRNA expression was up-regulated by both IGF-I and bcl-2. The potent anti-apoptotic systems IGF-I and bcl-2 are both thus able to enhance cell survival in a glucose-deprived human neuronal model. Although we clearly show evidence of positive cross-talk via bcl-2 modulation of IGF-I receptor, IGF-I also has enhancing effects on mitochondrial function outside the bcl-2 pathway. The common effect of both systems on enhancement of GLUT-1 expression suggests that this is a key mechanism for enhanced survival. These studies also point to the potential use of IGF-I therapy in prevention or amelioration of hypoglycaemic brain injury.
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Affiliation(s)
- V C Russo
- Centre for Hormone Research, Murdoch Childrens Research Institute, Royal Children's Hospital, Flemington Road, Parkville 3052, Victoria, Australia.
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18
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Abstract
BACKGROUND Children with chronic renal failure (CRF) exhibit growth retardation and a disturbed growth hormone/insulin-like growth factor-I (GH/IGF-I) axis. Treatment of children with CRF with GH or GH/IGF-I can partially restore linear growth. The molecular basis for decreased longitudinal growth is not known but may involve an impaired action of GH. METHODS We used the growth-retarded uremic rat model to determine the abundance and distribution of GH receptors (GHRs) in the tibial epiphyseal growth plate and the influence of GH, IGF-I, or combined GH/IGF-I treatment. Pair-fed rats were used as the control. RESULTS While all treatment regimes increased body length and weight in both rat groups, only GH/IGF-I treatment increased the total growth plate width. This involved an increase in cell number in the hypertrophic zone, which could also be induced by IGF-I alone. Immunohistochemical analysis showed that uremic rats had decreased abundance of GHRs in the proliferative zone, and only GH/IGF-I therapy could overcome this decrease. These data thus suggest that growth retardation in uremic rats is, at least in part, due to a decrease in GHR abundance in chondrocytes of the proliferative zone of the tibial growth plate. This decreased GHR abundance can be overcome by combined GH/IGF-I therapy, thus enhancing generation and proliferation of hypertrophic zone chondrocytes and increasing growth-plate width. CONCLUSION These studies point to a mechanism for the growth retardation seen in children with CRF, and suggest that combined GH/IGF-I treatment may provide more effective therapy for these patients than GH alone.
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Affiliation(s)
- S R Edmondson
- Centre for Hormone Research, Royal Children's Hospital, Parkville, Victoria, Australia.
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Baker NL, Carlo Russo V, Bernard O, D'Ercole AJ, Werther GA. Interactions between bcl-2 and the IGF system control apoptosis in the developing mouse brain. Brain Res Dev Brain Res 1999; 118:109-18. [PMID: 10611509 DOI: 10.1016/s0165-3806(99)00136-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The IGF system and the pro-survival Bcl-2 proteins protect cells from apoptosis and play a key role in brain development. In order to examine a possible relationship between these two potent anti-apoptotic systems, we utilised two transgenic mice models overexpressing either Bcl-2 or IGF-I proteins in olfactory bulb (OB) or cerebellar neurons, respectively. We have demonstrated that while the organization of the defined layers of the OB from the bcl-2 transgenic and wildtype mice cultured in serum free medium (SF) was similarly poor, the mitral cell layer from the transgenic mice was expanded and their neurons were well preserved. Addition of IGF-I improved the definition of the layers normally present within the OB, in both wildtype and bcl-2 transgenic mice, and restored wildtype mitral cell layer structure and neuronal survival similar to that in bcl-2 mice, whose mitral cell survival was not further enhanced by IGF-I. Immunoreactivity for IGF-I and IGFBP-2 was markedly increased in these Bcl-2-expressing mitral cells compared to wildtype mice. In newborn IGF-I transgenic mice, cerebellar Purkinje cells overexpressing IGF-I showed markedly increased immunoreactivity for Bcl-2 and IGFBP-2. These studies indicate that in the developing brain IGF-I modulates expression of its major binding protein IGFBP-2, as well as the Bcl-2 protein. In addition apoptosis caused by culturing OBs in SF medium, is inhibited by expression of Bcl-2 in the mitral neurons and is associated with enhanced expression of the IGF system, including IGF-I and IGFBP-2. The later may thus play a role in IGF targeting. This complex interaction between the two potent anti-apoptotic systems is likely to provide a robust system of cell protection during brain development and repair.
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Affiliation(s)
- N L Baker
- Centre for Hormone Research, Royal Children's Hospital, Flemington Road, Parkville, Victoria, Australia
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20
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Russo VC, Rekaris G, Baker NL, Bach LA, Werther GA. Basic fibroblast growth factor induces proteolysis of secreted and cell membrane-associated insulin-like growth factor binding protein-2 in human neuroblastoma cells. Endocrinology 1999; 140:3082-90. [PMID: 10385400 DOI: 10.1210/endo.140.7.6771] [Citation(s) in RCA: 24] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Insulin-like growth factor (IGF) action in the brain is modulated by IGF-binding proteins (IGFBPs) whose abundance can be altered by other locally expressed growth factors. However, the mechanisms involved are unclear. We here employed the neuroblastoma cell line SK-N-MC as a model to define the mechanisms involved in modulation of IGFBPs in neuronal cells. Western ligand blotting analysis and immunoprecipitation of conditioned media (CM) from SK-N-MC cells showed that in these cells, as in the brain, the most abundantly expressed IGFBP was IGFBP-2. However, IGFBP-2 was barely detectable in CM from cells treated with basic fibroblast growth factor (bFGF) without a change in IGFBP-2 messenger RNA (mRNA) abundance. These CM contained specific IGFBP-2 proteolytic activity, resulting in two IGFBP-2 fragments of 14 and 22 kDa. The activity was inhibited by EDTA/phenylmethylsulfonyl fluoride or aprotinin. Competitive binding studies indicated that IGFBP-2 fragments had reduced binding affinity for IGF-I. bFGF induced IGFBP-3 mRNA and protein. Affinity cross-linking of [125I]IGF-I to neuroblastoma cell membranes followed by immunoprecipitation revealed a approximately 38 kDa [125I]IGF-I/IGFBP-2 complex. Cell surface-associated IGFBP-2 was also susceptible to bFGF-induced proteolysis, with the appearance of a single cross-linked 21-kDa complex with low affinity for IGF-I. These findings indicate that intact IGFBP-2 and the 14-kDa, but not the 22-kDa fragment, bind to the cell surface. Our data suggest that induction of IGFBP-2 proteolysis on neuronal cell surface is a novel mechanism whereby IGF availability is modulated by the local growth factor bFGF.
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Affiliation(s)
- V C Russo
- Centre for Hormone Research, Royal Children's Hospital Research Institute, Parkville, Victoria, Australia
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21
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Beilharz EJ, Russo VC, Butler G, Baker NL, Connor B, Sirimanne ES, Dragunow M, Werther GA, Gluckman PD, Williams CE, Scheepens A. Co-ordinated and cellular specific induction of the components of the IGF/IGFBP axis in the rat brain following hypoxic-ischemic injury. Brain Res Mol Brain Res 1998; 59:119-34. [PMID: 9729323 DOI: 10.1016/s0169-328x(98)00122-3] [Citation(s) in RCA: 155] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Insulin-like growth factor 1 (IGF-1) is induced after hypoxic-ischemic (HI) brain injury, and therapeutic studies suggest that IGF-1 may restrict delayed neuronal and glial cell loss. We have used a well-characterised rat model of HI injury to extend our understanding of the modes of action of the IGF system after injury. The induction of the IGF system by injury was examined by in situ hybridization, immunohistochemistry, Northern blot analysis, RNase protection assay and reverse transcriptase-polymerase chain reaction (RT-PCR). IGF-1 accumulated in blood vessels of the damaged hemisphere within 5 h after a severe injury. By 3 days, IGF-1 mRNA was expressed by reactive microglia in regions of delayed neuronal death, and immunoreactive IGF-1 was associated with these microglia and reactive astrocytes juxtaposed to surviving neurones surrounding the infarct. Total IGF-1 receptor mRNA was unchanged by the injury. IGFBP-2 mRNA was strongly induced in reactive astrocytes throughout the injured hemisphere, and IGFBP-3 and IGFBP-5 mRNA were moderately induced in reactive microglia and neurones of the injured hippocampus, respectively. IGFBP-6 mRNA was induced in the damaged hemisphere by 3 days and increased protein was seen on the choroid plexus, ependyma and reactive glia. In contrast, insulin II was not induced. These results indicate cell type-specific expression for IGF-1, IGFBP-2,3,5 and 6 after injury. Our findings suggest that the IGF-1 produced by microglia after injury is transferred to perineuronal reactive astrocytes expressing IGFBP-2. Thus, modulation of IGF-1 action by IGFBP-2 might represent a key mechanism that restricts neuronal cell loss following HI brain injury.
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Affiliation(s)
- E J Beilharz
- Research Centre for Developmental Medicine and Biology, School of Medicine, University of Auckland, Private Bag 92019, Auckland, New Zealand
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Russo VC, Bach LA, Fosang AJ, Baker NL, Werther GA. Insulin-like growth factor binding protein-2 binds to cell surface proteoglycans in the rat brain olfactory bulb. Endocrinology 1997; 138:4858-67. [PMID: 9348216 DOI: 10.1210/endo.138.11.5472] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.7] [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] [Indexed: 02/05/2023]
Abstract
A family of six insulin-like growth factor binding proteins (IGFBPs) bind IGF-I and modulate its biological activity. IGFBPs may bind to macromolecules on the cell surface or pericellular extracellular matrix, and this interaction may modulate their effect on IGF activity. To date, little is known about the specificity of IGFBPs in the regulation of IGF action in the brain. We therefore explored whether IGFBPs were associated with cell membrane or extracellular matrix components in the rat brain. IGF-I binding sites with the characteristics of an IGFBP were found in the olfactory bulb mitral cell layer. This IGFBP was identified as IGFBP-2 by immunoprecipitation of both solubilized membrane preparations and cross-linked 125I-IGF: IGFBP complexes. While binding of IGFBP-2 to cell membranes was unaffected by RGD-containing peptide, it was inhibited by high salt concentration, suggesting interaction with proteoglycans. IGFBP-2 bound in vitro to the glycosaminoglycans chondroitin-4 and -6-sulfate, keratan sulfate, and heparin. IGFBP-2 also bound the proteoglycan aggrecan, an effect reduced by digestion of its glycosaminoglycans. Binding of IGFBP-2 to chondroitin-6-sulfate decreased the binding affinity of IGFBP-2 for IGF-I approximately 3-fold. Finally, an IGFBP-2 antibody coimmunoprecipitated IGFBP-2 and an approximately 200 kDa proteoglycan containing chondroitin-sulfate side chains from the rat olfactory bulb, providing definitive evidence for IGFBP-2 binding to olfactory bulb proteoglycans. These findings indicate that IGFBP-2 binds to proteoglycans in cell membranes of the rat olfactory bulb. Because we have previously shown that IGFs are highly expressed in the rat olfactory bulb, cell associated IGFBP-2 may have an important role in directing IGFs to specific sites in this brain region.
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Affiliation(s)
- V C Russo
- The Centre for Hormone Research, Royal Children's Hospital, Parkville, Victoria, Australia
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Loos JM, Baker NL, Bergers RM. Evaluation of the extent of nursing involvement required with home pentamidine isethionate infusions. J Intraven Nurs 1989; 12:52-6. [PMID: 2784497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
A retrospective review of 20 patients was undertaken to evaluate the extent of nursing involvement required in patients receiving daily Pentamidine infusions. The population was divided into two groups: a) nurse-administered infusions, and b) self-administered infusions. Both groups were evaluated for: 1. Incidence and severity of side effects; 2. Prophylactic measures; 3. Length of infusion and/or nursing visit. A protocol was developed for self-administration of Pentamidine and criteria established for patients to qualify for this independent responsibility. With established protocols and comprehensive patient education, select individuals can safely administer Pentamidine at home with less nursing involvement than previously recognized.
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Bergers RM, Baker NL, Loos J. Eleven hundred outpatient days of amphotericin B therapy. NITA 1987; 10:292-6. [PMID: 3650727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Hobbs MV, Morgan EL, Baker NL, Weigle WO. Regulation of antibody responses by rheumatoid factor. I. Polyclonal activation of human B cells by rheumatoid factor-containing preparations from seropositive plasma. The Journal of Immunology 1985. [DOI: 10.4049/jimmunol.134.1.223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Rheumatoid factor (RF)-containing IgM preparations isolated from the plasma of two seropositive patients were able to increase the number of Ig-secreting cells in normal human peripheral blood lymphocyte cultures. This polyclonal B cell activation was optimal in the presence of both T cells and monocytes. A relationship was established between the activator and RF in these preparations based on the ability of both to bind to insolubilized human IgG. The presence of the activator also coincided with the presence of large, RF-containing Ig complexes. These data suggest that RF contributes to the formation of B cell-stimulating immune complexes--a phenomenon with possible negative consequences in disease states characterized by these complexes.
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Hobbs MV, Morgan EL, Baker NL, Weigle WO. Regulation of antibody responses by rheumatoid factor. I. Polyclonal activation of human B cells by rheumatoid factor-containing preparations from seropositive plasma. J Immunol 1985; 134:223-9. [PMID: 3871100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Rheumatoid factor (RF)-containing IgM preparations isolated from the plasma of two seropositive patients were able to increase the number of Ig-secreting cells in normal human peripheral blood lymphocyte cultures. This polyclonal B cell activation was optimal in the presence of both T cells and monocytes. A relationship was established between the activator and RF in these preparations based on the ability of both to bind to insolubilized human IgG. The presence of the activator also coincided with the presence of large, RF-containing Ig complexes. These data suggest that RF contributes to the formation of B cell-stimulating immune complexes--a phenomenon with possible negative consequences in disease states characterized by these complexes.
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