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Moulton MJ, Atala K, Zheng Y, Dutta D, Grange DK, Lin WW, Wegner DJ, Wambach JA, Duker AL, Bober MB, Kratz L, Wise CA, Oxendine I, Khanshour A, Wangler MF, Yamamoto S, Cole FS, Rios J, Bellen HJ. Dominant missense variants in SREBF2 are associated with complex dermatological, neurological, and skeletal abnormalities. Genet Med 2024; 26:101174. [PMID: 38847193 DOI: 10.1016/j.gim.2024.101174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 05/28/2024] [Accepted: 05/29/2024] [Indexed: 07/21/2024] Open
Abstract
PURPOSE We identified 2 individuals with de novo variants in SREBF2 that disrupt a conserved site 1 protease (S1P) cleavage motif required for processing SREBP2 into its mature transcription factor. These individuals exhibit complex phenotypic manifestations that partially overlap with sterol regulatory element binding proteins (SREBP) pathway-related disease phenotypes, but SREBF2-related disease has not been previously reported. Thus, we set out to assess the effects of SREBF2 variants on SREBP pathway activation. METHODS We undertook ultrastructure and gene expression analyses using fibroblasts from an affected individual and utilized a fly model of lipid droplet (LD) formation to investigate the consequences of SREBF2 variants on SREBP pathway function. RESULTS We observed reduced LD formation, endoplasmic reticulum expansion, accumulation of aberrant lysosomes, and deficits in SREBP2 target gene expression in fibroblasts from an affected individual, indicating that the SREBF2 variant inhibits SREBP pathway activation. Using our fly model, we discovered that SREBF2 variants fail to induce LD production and act in a dominant-negative manner, which can be rescued by overexpression of S1P. CONCLUSION Taken together, these data reveal a mechanism by which SREBF2 pathogenic variants that disrupt the S1P cleavage motif cause disease via dominant-negative antagonism of S1P, limiting the cleavage of S1P targets, including SREBP1 and SREBP2.
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Affiliation(s)
- Matthew J Moulton
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX
| | - Kristhen Atala
- Center for Translational Research, Scottish Rite for Children, Dallas, TX
| | - Yiming Zheng
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX; Current address: State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, China
| | - Debdeep Dutta
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX
| | - Dorothy K Grange
- Edward Mallinckrodt Department of Pediatrics, Washington University in St. Louis School of Medicine and St. Louis Children's Hospital, St. Louis, MO
| | - Wen-Wen Lin
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX
| | - Daniel J Wegner
- Edward Mallinckrodt Department of Pediatrics, Washington University in St. Louis School of Medicine and St. Louis Children's Hospital, St. Louis, MO
| | - Jennifer A Wambach
- Edward Mallinckrodt Department of Pediatrics, Washington University in St. Louis School of Medicine and St. Louis Children's Hospital, St. Louis, MO
| | - Angela L Duker
- Skeletal Dysplasia Program, Orthogenetics, Nemours Children's Hospital, Wilmington, DE
| | - Michael B Bober
- Skeletal Dysplasia Program, Orthogenetics, Nemours Children's Hospital, Wilmington, DE
| | - Lisa Kratz
- Kennedy Krieger Institute, Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Carol A Wise
- Center for Translational Research, Scottish Rite for Children, Dallas, TX; Eugene McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, TX; Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX; Department of Orthopedic Surgery, University of Texas Southwestern Medical Center, Dallas, TX
| | - Ila Oxendine
- Center for Translational Research, Scottish Rite for Children, Dallas, TX
| | - Anas Khanshour
- Center for Translational Research, Scottish Rite for Children, Dallas, TX
| | - Michael F Wangler
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX
| | - Shinya Yamamoto
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX
| | - F Sessions Cole
- Edward Mallinckrodt Department of Pediatrics, Washington University in St. Louis School of Medicine and St. Louis Children's Hospital, St. Louis, MO
| | - Jonathan Rios
- Center for Translational Research, Scottish Rite for Children, Dallas, TX; Eugene McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, TX; Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX; Department of Orthopedic Surgery, University of Texas Southwestern Medical Center, Dallas, TX
| | - Hugo J Bellen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX.
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2
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Jovanovic M, Marini JC. Update on the Genetics of Osteogenesis Imperfecta. Calcif Tissue Int 2024:10.1007/s00223-024-01266-5. [PMID: 39127989 DOI: 10.1007/s00223-024-01266-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2024] [Accepted: 07/22/2024] [Indexed: 08/12/2024]
Abstract
Osteogenesis imperfecta (OI) is a heterogeneous heritable skeletal dysplasia characterized by bone fragility and deformity, growth deficiency, and other secondary connective tissue defects. OI is now understood as a collagen-related disorder caused by defects of genes whose protein products interact with collagen for folding, post-translational modification, processing and trafficking, affecting bone mineralization and osteoblast differentiation. This review provides the latest updates on genetics of OI, including new developments in both dominant and rare OI forms, as well as the signaling pathways involved in OI pathophysiology. There is a special emphasis on discoveries of recessive mutations in TENT5A, MESD, KDELR2 and CCDC134 whose causality of OI types XIX, XX, XXI and XXI, respectively, is now established and expends the complexity of mechanisms underlying OI to overlap LRP5/6 and MAPK/ERK pathways. We also review in detail new discoveries connecting the known OI types to each other, which may underlie an eventual understanding of a final common pathway in OI cellular and bone biology.
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Affiliation(s)
- Milena Jovanovic
- Section on Heritable Disorders of Bone and Extracellular Matrix, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
- Section on Adolescent Bone and Body Composition, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Joan C Marini
- Section on Heritable Disorders of Bone and Extracellular Matrix, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA.
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3
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Raggio V, Rodríguez S, Feder S, Gueçaimburú R, Spangenberg L. Exome Sequencing Reveals Biallelic Mutations in MBTPS1 Gene in a Girl with a Very Rare Skeletal Dysplasia. Diagnostics (Basel) 2024; 14:313. [PMID: 38337829 PMCID: PMC10855125 DOI: 10.3390/diagnostics14030313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 12/28/2023] [Accepted: 01/03/2024] [Indexed: 02/12/2024] Open
Abstract
The Kondo-Fu type of spondyloepiphyseal dysplasia (SEDKF) is a rare skeletal dysplasia caused by homozygous or compound heterozygous mutations in the MBTPS1 gene. The MBTPS1 gene encodes a protein that is involved in the regulation of cholesterol and fatty acid metabolism. Mutations in MBTPS1 can lead to reduced levels of these lipids, which can have a number of effects on development, including skeletal anomalies, growth retardation, and elevated levels of blood lysosomal enzymes. This work reports the case of a 5-year-old girl with SEDKF. The patient had a severely short stature and a number of skeletal anomalies, including kyphosis, pectus carinatum, and reduced bone mineral density. She also had early onset cataracts and inguinal hernias. Genetic testing revealed two novel compound heterozygous variants in the MBTPS1 gene. These variants are predicted to disrupt the function of the MBTPS1 protein, which is consistent with the patient's clinical presentation. This case report adds to the growing body of evidence that mutations in the MBTPS1 gene are causal of SEDKF. We summarized the features of previous reported cases (with age ranges from 4 to 24 years) and identified that 80% had low stature, 70% low weight, 80% had bilateral cataracts and 70% showed Spondyloepiphyseal dysplasia on X-rays. The findings of this study suggest that SEDKF is a clinically heterogeneous disorder that can present with a variety of features. Further studies are needed to better understand the underlying mechanisms of SEDKF and to develop more effective treatments.
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Affiliation(s)
- Víctor Raggio
- Departamento de Genética, Facultad de Medicina, Universidad de la República, Montevideo 11800, Uruguay; (V.R.); (S.R.)
| | - Soledad Rodríguez
- Departamento de Genética, Facultad de Medicina, Universidad de la República, Montevideo 11800, Uruguay; (V.R.); (S.R.)
| | - Sandra Feder
- Laboratorio de Genética Clínica Genodiagnosis, Montevideo 11600, Uruguay;
| | - Rosario Gueçaimburú
- Centro de Referencia Nacional de Defectos Congénitos y Enfermedades Raras (CRENADECER), Av. Agraciada 2989, Montevideo 11800, Uruguay;
- Hospital Británico, Av. Italia 2420, Montevideo 11600, Uruguay
| | - Lucía Spangenberg
- Departamento Básico de Medicina, Hospital de Clínicas, Facultad de Medicina, Universidad de la República, Montevideo 11600, Uruguay
- Bioinformatics Unit, Institut Pasteur de Montevideo, Montevideo 11400, Uruguay
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4
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Chen N, Wu RW, Lam Y, Chan WC, Chan D. Hypertrophic chondrocytes at the junction of musculoskeletal structures. Bone Rep 2023; 19:101698. [PMID: 37485234 PMCID: PMC10359737 DOI: 10.1016/j.bonr.2023.101698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 06/12/2023] [Accepted: 07/01/2023] [Indexed: 07/25/2023] Open
Abstract
Hypertrophic chondrocytes are found at unique locations at the junction of skeletal tissues, cartilage growth plate, articular cartilage, enthesis and intervertebral discs. Their role in the skeleton is best understood in the process of endochondral ossification in development and bone fracture healing. Chondrocyte hypertrophy occurs in degenerative conditions such as osteoarthritis. Thus, the role of hypertrophic chondrocytes in skeletal biology and pathology is context dependent. This review will focus on hypertrophic chondrocytes in endochondral ossification, in which they exist in a transient state, but acting as a central regulator of differentiation, mineralization, vascularization and conversion to bone. The amazing journey of a chondrocyte from being entrapped in the extracellular matrix environment to becoming proliferative then hypertrophic will be discussed. Recent studies on the dynamic changes and plasticity of hypertrophic chondrocytes have provided new insights into how we view these cells, not as terminally differentiated but as cells that can dedifferentiate to more progenitor-like cells in a transition to osteoblasts and adipocytes, as well as a source of skeletal stem and progenitor cells residing in the bone marrow. This will provide a foundation for studies of hypertrophic chondrocytes at other skeletal sites in development, tissue maintenance, pathology and therapy.
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Affiliation(s)
- Ning Chen
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Robin W.H. Wu
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Yan Lam
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Wilson C.W. Chan
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
- Department of Orthopaedics Surgery and Traumatology, The University of Hong Kong-Shenzhen Hospital (HKU-SZH), Shenzhen 518053, China
| | - Danny Chan
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
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Mousa MG, Vuppaladhadiam L, Kelly MO, Pietka T, Ek S, Shen KC, Meyer GA, Finck BN, Brookheart RT. Site-1 protease inhibits mitochondrial respiration by controlling the TGF-β target gene Mss51. Cell Rep 2023; 42:112336. [PMID: 37002920 PMCID: PMC10544680 DOI: 10.1016/j.celrep.2023.112336] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 02/17/2023] [Accepted: 03/20/2023] [Indexed: 04/03/2023] Open
Abstract
The mitochondrial response to changes in cellular energy demand is necessary for cellular adaptation and organ function. Many genes are essential in orchestrating this response, including the transforming growth factor (TGF)-β1 target gene Mss51, an inhibitor of skeletal muscle mitochondrial respiration. Although Mss51 is implicated in the pathophysiology of obesity and musculoskeletal disease, how Mss51 is regulated is not entirely understood. Site-1 protease (S1P) is a key activator of several transcription factors required for cellular adaptation. However, the role of S1P in muscle is unknown. Here, we identify S1P as a negative regulator of muscle mass and mitochondrial respiration. S1P disruption in mouse skeletal muscle reduces Mss51 expression and increases muscle mass and mitochondrial respiration. The effects of S1P deficiency on mitochondrial activity are counteracted by overexpressing Mss51, suggesting that one way S1P inhibits respiration is by regulating Mss51. These discoveries expand our understanding of TGF-β signaling and S1P function.
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Affiliation(s)
- Muhammad G Mousa
- John T. Milliken Department of Medicine, Division of Geriatrics and Nutritional Sciences, Washington University School of Medicine, St. Louis, MO 61110, USA
| | - Lahari Vuppaladhadiam
- John T. Milliken Department of Medicine, Division of Geriatrics and Nutritional Sciences, Washington University School of Medicine, St. Louis, MO 61110, USA
| | - Meredith O Kelly
- John T. Milliken Department of Medicine, Division of Geriatrics and Nutritional Sciences, Washington University School of Medicine, St. Louis, MO 61110, USA
| | - Terri Pietka
- John T. Milliken Department of Medicine, Division of Geriatrics and Nutritional Sciences, Washington University School of Medicine, St. Louis, MO 61110, USA
| | - Shelby Ek
- John T. Milliken Department of Medicine, Division of Geriatrics and Nutritional Sciences, Washington University School of Medicine, St. Louis, MO 61110, USA
| | - Karen C Shen
- Program in Physical Therapy, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Gretchen A Meyer
- Program in Physical Therapy, Washington University School of Medicine, St. Louis, MO 63110, USA; Departments of Orthopaedic Surgery and Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Biomedical Engineering, Washington University, St. Louis, MO 63130, USA
| | - Brian N Finck
- John T. Milliken Department of Medicine, Division of Geriatrics and Nutritional Sciences, Washington University School of Medicine, St. Louis, MO 61110, USA
| | - Rita T Brookheart
- John T. Milliken Department of Medicine, Division of Geriatrics and Nutritional Sciences, Washington University School of Medicine, St. Louis, MO 61110, USA.
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6
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Jovanovic M, Guterman-Ram G, Marini JC. Osteogenesis Imperfecta: Mechanisms and Signaling Pathways Connecting Classical and Rare OI Types. Endocr Rev 2022; 43:61-90. [PMID: 34007986 PMCID: PMC8755987 DOI: 10.1210/endrev/bnab017] [Citation(s) in RCA: 54] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Osteogenesis imperfecta (OI) is a phenotypically and genetically heterogeneous skeletal dysplasia characterized by bone fragility, growth deficiency, and skeletal deformity. Previously known to be caused by defects in type I collagen, the major protein of extracellular matrix, it is now also understood to be a collagen-related disorder caused by defects in collagen folding, posttranslational modification and processing, bone mineralization, and osteoblast differentiation, with inheritance of OI types spanning autosomal dominant and recessive as well as X-linked recessive. This review provides the latest updates on OI, encompassing both classical OI and rare forms, their mechanism, and the signaling pathways involved in their pathophysiology. There is a special emphasis on mutations in type I procollagen C-propeptide structure and processing, the later causing OI with strikingly high bone mass. Types V and VI OI, while notably different, are shown to be interrelated by the interferon-induced transmembrane protein 5 p.S40L mutation that reveals the connection between the bone-restricted interferon-induced transmembrane protein-like protein and pigment epithelium-derived factor pathways. The function of regulated intramembrane proteolysis has been extended beyond cholesterol metabolism to bone formation by defects in regulated membrane proteolysis components site-2 protease and old astrocyte specifically induced-substance. Several recently proposed candidate genes for new types of OI are also presented. Discoveries of new OI genes add complexity to already-challenging OI management; current and potential approaches are summarized.
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Affiliation(s)
- Milena Jovanovic
- Section on Heritable Disorders of Bone and Extracellular Matrix, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Gali Guterman-Ram
- Section on Heritable Disorders of Bone and Extracellular Matrix, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Joan C Marini
- Section on Heritable Disorders of Bone and Extracellular Matrix, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
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7
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Proteolytic processing of secretory pathway kinase Fam20C by site-1 protease promotes biomineralization. Proc Natl Acad Sci U S A 2021; 118:2100133118. [PMID: 34349020 DOI: 10.1073/pnas.2100133118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Family with sequence similarity 20C (Fam20C), the major protein kinase in the secretory pathway, generates the vast majority of the secreted phosphoproteome. However, the regulatory mechanisms of Fam20C transport, secretion, and function remain largely unexplored. Here, we show that Fam20C exists as a type II transmembrane protein within the secretory compartments, with its N-terminal signal peptide-like region serving as a membrane anchor for Golgi retention. The secretion and kinase activity of Fam20C are governed by site-1 protease (S1P), a key regulator of cholesterol homeostasis. We find that only mature Fam20C processed by S1P functions in osteoblast differentiation and mineralization. Together, our findings reveal a unique mechanism for Fam20C secretion and activation via proteolytic regulation, providing a molecular link between biomineralization and lipid metabolism.
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8
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Site-1 protease controls osteoclastogenesis by mediating LC3 transcription. Cell Death Differ 2021; 28:2001-2018. [PMID: 33469231 PMCID: PMC8184842 DOI: 10.1038/s41418-020-00731-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 12/29/2020] [Indexed: 01/30/2023] Open
Abstract
Site-1 protease (S1P) is a Golgi-located protein that activates unique membrane-bound latent transcription factors, and it plays an indispensable role in endoplasmic reticulum stress, lipid metabolism, inflammatory response and lysosome function. A patient with S1P mutation exhibits severe skeletal dysplasia with kyphoscoliosis, dysmorphic facial features and pectus carinatum. However, whether S1P regulates bone remodeling by affecting osteoclastogenesis remains elusive. Here, we show that S1P is indeed a positive regulator of osteoclastogenesis. S1P ablation in mice led to significant osteosclerosis compared with wild-type littermates. Mechanistically, S1P showed upregulated during osteoclastogenesis and was identified as a direct target of miR-9-5p. S1P deletion in bone marrow monocytes (BMMs) inhibited ATF6 and SREBP2 maturation, which subsequently impeded CHOP/SREBP2-complex-induced LC3 expression and autophagy flux. Consistently, transfection of LC3 adenovirus evidently rescued osteoclastogenesis in S1P-deficient BMMs. We then identified the interaction regions between CHOP and SREBP2 by Co-immunoprecipitation (Co-IP) and molecular docking. Furthermore, S1P deletion or inhibitor efficaciously rescued ovariectomized (OVX)- and LPS-induced bone loss in vivo. Collectively, we showed that S1P regulates osteoclast differentiation in a LC3 dependent manner and so is a potential therapy target for osteoporosis.
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Patra D, Kim J, Zhang Q, Tycksen E, Sandell LJ. Site-1 protease ablation in the osterix-lineage in mice results in bone marrow neutrophilia and hematopoietic stem cell alterations. Biol Open 2020; 9:bio052993. [PMID: 32576566 PMCID: PMC7328000 DOI: 10.1242/bio.052993] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 04/24/2020] [Indexed: 01/03/2023] Open
Abstract
Site-1 protease (S1P) ablation in the osterix-lineage in mice drastically reduces bone development and downregulates bone marrow-derived skeletal stem cells. Here we show that these mice also suffer from spina bifida occulta with a characteristic lack of bone fusion in the posterior neural arches. Molecular analysis of bone marrow-derived non-red blood cell cells, via single-cell RNA-Seq and protein mass spectrometry, demonstrate that these mice have a much-altered bone marrow with a significant increase in neutrophils and Ly6C-expressing leukocytes. The molecular composition of bone marrow neutrophils is also different as they express more and additional members of the stefin A (Stfa) family of proteins. In vitro, recombinant Stfa1 and Stfa2 proteins have the ability to drastically inhibit osteogenic differentiation of bone marrow stromal cells, with no effect on adipogenic differentiation. FACS analysis of hematopoietic stem cells show that despite a decrease in hematopoietic stem cells, S1P ablation results in an increased production of granulocyte-macrophage progenitors, the precursors to neutrophils. These observations indicate that S1P has a role in the lineage specification of hematopoietic stem cells and/or their progenitors for development of a normal hematopoietic niche. Our study designates a fundamental requirement of S1P for maintaining a balanced regenerative capacity of the bone marrow niche.
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Affiliation(s)
- Debabrata Patra
- Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Joongho Kim
- Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Qiang Zhang
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Eric Tycksen
- McDonnell Genome Institute, Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Linda J Sandell
- Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, MO 63110, USA
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10
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Different Forms of ER Stress in Chondrocytes Result in Short Stature Disorders and Degenerative Cartilage Diseases: New Insights by Cartilage-Specific ERp57 Knockout Mice. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:8421394. [PMID: 30647818 PMCID: PMC6311764 DOI: 10.1155/2018/8421394] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 11/13/2018] [Indexed: 02/06/2023]
Abstract
Cartilage is essential for skeletal development by endochondral ossification. The only cell type within the tissue, the chondrocyte, is responsible for the production of macromolecules for the extracellular matrix (ECM). Before proteins and proteoglycans are secreted, they undergo posttranslational modification and folding in the endoplasmic reticulum (ER). However, the ER folding capacity in the chondrocytes has to be balanced with physiological parameters like energy and oxygen levels. Specific cellular conditions, e.g., a high protein demand, or pathologic situations disrupt ER homeostasis and lead to the accumulation of poorly folded or misfolded proteins. This state is called ER stress and induces a cellular quality control system, the unfolded protein response (UPR), to restore homeostasis. Different mouse models with ER stress in chondrocytes display comparable skeletal phenotypes representing chondrodysplasias. Therefore, ER stress itself seems to be involved in the pathogenesis of these diseases. It is remarkable that chondrodysplasias with a comparable phenotype arise independent from the sources of ER stress, which are as follows: (1) mutations in ECM proteins leading to aggregation, (2) deficiencies in ER chaperones, (3) mutations in UPR signaling factors, or (4) deficiencies in the degradation of aggregated proteins. In any case, the resulting UPR substantially impairs ECM protein synthesis, chondrocyte proliferation, and/or differentiation or regulation of autophagy and apoptosis. Notably, chondrodysplasias arise no matter if single or multiple events are affected. We analyzed cartilage-specific ERp57 knockout mice and demonstrated that the deficiency of this single protein disulfide isomerase, which is responsible for formation of disulfide bridges in ECM glycoproteins, is sufficient to induce ER stress and to cause an ER stress-related bone phenotype. These mice therefore qualify as a novel model for the analysis of ER stress in chondrocytes. They give new insights in ER stress-related short stature disorders and enable the analysis of ER stress in other cartilage diseases, such as osteoarthritis.
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11
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Enzymatic sources and physio-pathological functions of soluble (pro)renin receptor. Curr Opin Nephrol Hypertens 2018; 27:77-82. [PMID: 29346132 DOI: 10.1097/mnh.0000000000000396] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
PURPOSE OF REVIEW (Pro)renin receptor (PRR) belongs to type I transmembrane receptor family and binds both prorenin and renin, representing a potential regulator of the activity of the renin-angiotensin system. Soluble form of PRR (sPRR) is generated by intracellular protease-mediated cleavage of full-length PRR. The purpose of this review is to highlight recent advances in understanding the mechanisms of action and production of sPRR. RECENT FINDINGS It has recently been demonstrated that site-1-protease (S1P) plays a dominant role in the generation of sPRR. New evidence is also emerging to support a biological function of sPRR in the physiological regulation of fluid homeostasis as well as pathogenesis of chronic kidney disease. SUMMARY sPRR is a 28 kDa product of PRR cleavage via S1P-mediated protease activity. Not only does sPRR regulate renal tubular water transport, but it also mediates pathogenic responses to renal cellular injury. sPRR is likely involved in a wide range of physio-pathological processes.
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12
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Kondo Y, Fu J, Wang H, Hoover C, McDaniel JM, Steet R, Patra D, Song J, Pollard L, Cathey S, Yago T, Wiley G, Macwana S, Guthridge J, McGee S, Li S, Griffin C, Furukawa K, James JA, Ruan C, McEver RP, Wierenga KJ, Gaffney PM, Xia L. Site-1 protease deficiency causes human skeletal dysplasia due to defective inter-organelle protein trafficking. JCI Insight 2018; 3:121596. [PMID: 30046013 PMCID: PMC6124414 DOI: 10.1172/jci.insight.121596] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 06/08/2018] [Indexed: 01/18/2023] Open
Abstract
Site-1 protease (S1P), encoded by MBTPS1, is a serine protease in the Golgi. S1P regulates lipogenesis, endoplasmic reticulum (ER) function, and lysosome biogenesis in mice and in cultured cells. However, how S1P differentially regulates these diverse functions in humans has been unclear. In addition, no human disease with S1P deficiency has been identified. Here, we report a pediatric patient with an amorphic and a severely hypomorphic mutation in MBTPS1. The unique combination of these mutations results in a frequency of functional MBTPS1 transcripts of approximately 1%, a finding that is associated with skeletal dysplasia and elevated blood lysosomal enzymes. We found that the residually expressed S1P is sufficient for lipid homeostasis but not for ER and lysosomal functions, especially in chondrocytes. The defective S1P function specifically impairs activation of the ER stress transducer BBF2H7, leading to ER retention of collagen in chondrocytes. S1P deficiency also causes abnormal secretion of lysosomal enzymes due to partial impairment of mannose-6-phosphate-dependent delivery to lysosomes. Collectively, these abnormalities lead to apoptosis of chondrocytes and lysosomal enzyme-mediated degradation of the bone matrix. Correction of an MBTPS1 variant or reduction of ER stress mitigated collagen-trafficking defects. These results define a new congenital human skeletal disorder and, more importantly, reveal that S1P is particularly required for skeletal development in humans. Our findings may also lead to new therapies for other genetic skeletal diseases, as ER dysfunction is common in these disorders.
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Affiliation(s)
- Yuji Kondo
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, USA
| | - Jianxin Fu
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, USA.,Jiangsu Institute of Hematology, MOH Key Laboratory of Thrombosis and Hemostasis, Collaborative Innovation Center of Hematology, The First Affiliated Hospital of Soochow University, Suzhou, China
| | | | - Christopher Hoover
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, USA.,Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - J Michael McDaniel
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, USA
| | - Richard Steet
- Complex Carbohydrate Research Center, University of Georgia, Georgia, Athens, USA
| | - Debabrata Patra
- Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Jianhua Song
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, USA
| | - Laura Pollard
- Greenwood Genetic Center, Greenwood, South Carolina, USA
| | - Sara Cathey
- Greenwood Genetic Center, Greenwood, South Carolina, USA
| | - Tadayuki Yago
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, USA
| | - Graham Wiley
- Division of Genomics and Data Sciences, Arthritis and Clinical Immunology Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, USA
| | - Susan Macwana
- Division of Genomics and Data Sciences, Arthritis and Clinical Immunology Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, USA
| | - Joel Guthridge
- Division of Genomics and Data Sciences, Arthritis and Clinical Immunology Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, USA
| | - Samuel McGee
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, USA
| | | | - Courtney Griffin
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, USA
| | - Koichi Furukawa
- Department of Biochemistry II, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Judith A James
- Division of Genomics and Data Sciences, Arthritis and Clinical Immunology Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, USA
| | - Changgeng Ruan
- Jiangsu Institute of Hematology, MOH Key Laboratory of Thrombosis and Hemostasis, Collaborative Innovation Center of Hematology, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Rodger P McEver
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, USA.,Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | | | - Patrick M Gaffney
- Division of Genomics and Data Sciences, Arthritis and Clinical Immunology Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, USA
| | - Lijun Xia
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, USA.,Jiangsu Institute of Hematology, MOH Key Laboratory of Thrombosis and Hemostasis, Collaborative Innovation Center of Hematology, The First Affiliated Hospital of Soochow University, Suzhou, China.,Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
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13
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Patra D, DeLassus E, Mueller J, Abou-Ezzi G, Sandell LJ. Site-1 protease regulates skeletal stem cell population and osteogenic differentiation in mice. Biol Open 2018; 7:bio.032094. [PMID: 29437042 PMCID: PMC5861364 DOI: 10.1242/bio.032094] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Site-1 protease (S1P) is a proprotein convertase with essential functions in the conversion of precursor proteins to their active form. In earlier studies, we demonstrated that S1P ablation in the chondrocyte lineage results in a drastic reduction in endochondral bone formation. To investigate the mechanistic contribution of S1P to bone development we ablated S1P in the osterix lineage in mice. S1P ablation in this lineage results in osteochondrodysplasia and variable degrees of early postnatal scoliosis. Embryonically, even though Runx2 and osterix expression are normal, S1P ablation results in a delay in vascular invasion and endochondral bone development. Mice appear normal when born, but by day 7 display pronounced dwarfism with fragile bones that exhibit significantly reduced mineral density, mineral apposition rate, bone formation rate and reduced osteoblasts indicating severe osteopenia. Mice suffer from a drastic reduction in bone marrow mesenchymal progenitors as analyzed by colony-forming unit-fibroblast assay. Fluorescence-activated cell sorting analysis of the skeletal mesenchyme harvested from bone marrow and collagenase-digested bone show a drastic reduction in hematopoietic lineage-negative, endothelial-negative, CD105+ skeletal stem cells. Bone marrow mesenchymal progenitors are unable to differentiate into osteoblasts in vitro, with no effect on adipogenic differentiation. Postnatal mice have smaller growth plates with reduced hypertrophic zone. Thus, S1P controls bone development directly by regulating the skeletal progenitor population and their differentiation into osteoblasts. This article has an associated First Person interview with the first author of the paper. Summary: S1P governs a fundamental aspect of skeletal development and homeostasis, mainly the maintenance and osteogenic differentiation of skeletogenic stem cells that are a source of osteoblast and chondrocyte lineages.
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Affiliation(s)
- Debabrata Patra
- Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Elizabeth DeLassus
- Department of Biochemistry, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Jennifer Mueller
- Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Grazia Abou-Ezzi
- Department of Medicine, Oncology Division, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Linda J Sandell
- Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, MO 63110, USA.,Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110, USA
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14
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Engelking LJ, Cantoria MJ, Xu Y, Liang G. Developmental and extrahepatic physiological functions of SREBP pathway genes in mice. Semin Cell Dev Biol 2017; 81:98-109. [PMID: 28736205 DOI: 10.1016/j.semcdb.2017.07.011] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 07/07/2017] [Indexed: 12/17/2022]
Abstract
Sterol regulatory element-binding proteins (SREBPs), master transcriptional regulators of cholesterol and fatty acid synthesis, have been found to contribute to a diverse array of cellular processes. In this review, we focus on genetically engineered mice in which the activities of six components of the SREBP gene pathway, namely SREBP-1, SREBP-2, Scap, Insig-1, Insig-2, or Site-1 protease have been altered through gene knockout or transgenic approaches. In addition to the expected impacts on lipid metabolism, manipulation of these genes in mice is found to affect a wide array of developmental and physiologic processes ranging from interferon signaling in macrophages to synaptic transmission in the brain. The findings reviewed herein provide a blueprint to guide future studies defining the complex interactions between lipid biology and the physiologic processes of many distinct organ systems.
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Affiliation(s)
- Luke J Engelking
- Departments of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA.
| | - Mary Jo Cantoria
- Departments of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Yanchao Xu
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Guosheng Liang
- Departments of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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15
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Site-1 protease and lysosomal homeostasis. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017; 1864:2162-2168. [PMID: 28693924 DOI: 10.1016/j.bbamcr.2017.06.023] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 06/29/2017] [Accepted: 06/30/2017] [Indexed: 11/22/2022]
Abstract
The Golgi-resident site-1 protease (S1P) is a key regulator of cholesterol homeostasis and ER stress responses by converting latent transcription factors sterol regulatory element binding proteins (SREPBs) and activating transcription factor 6 (ATF6), as well as viral glycoproteins to their active forms. S1P is also essential for lysosome biogenesis via proteolytic activation of the hexameric GlcNAc-1-phosphotransferase complex required for modification of newly synthesized lysosomal enzymes with the lysosomal targeting signal, mannose 6-phosphate. In the absence of S1P, the catalytically inactive α/β-subunit precursor of GlcNAc-1-phosphotransferase fails to be activated and results in missorting of newly synthesized lysosomal enzymes, and lysosomal accumulation of non-degraded material, which are biochemical features of defective GlcNAc-1-phosphotransferase subunits and the associated pediatric lysosomal diseases mucolipidosis type II and III. The early embryonic death of S1P-deficient mice and the importance of various S1P-regulated biological processes, including lysosomal homeostasis, cautioned for clinical inhibition of S1P. This article is part of a Special Issue entitled: Proteolysis as a Regulatory Event in Pathophysiology edited by Stefan Rose-John.
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16
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Human Subtilisin Kexin Isozyme-1 (SKI-1)/Site-1 Protease (S1P) regulates cytoplasmic lipid droplet abundance: A potential target for indirect-acting anti-dengue virus agents. PLoS One 2017; 12:e0174483. [PMID: 28339489 PMCID: PMC5365115 DOI: 10.1371/journal.pone.0174483] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Accepted: 03/09/2017] [Indexed: 01/12/2023] Open
Abstract
Viral hijacking and manipulation of host-cell biosynthetic pathways by human enveloped viruses are shared molecular events essential for the viral lifecycle. For Flaviviridae members such as hepatitis C virus and dengue virus (DENV), one of the key subsets of cellular pathways that undergo manipulation is the lipid metabolic pathways, underlining the importance of cellular lipids and, in particular, lipid droplets (LDs) in viral infection. Here, we hypothesize that targeting cellular enzymes that act as key regulators of lipid homeostasis and LD formation could represent a powerful approach to developing a novel class of broad-spectrum antivirals against infection associated with all DENV serotypes (1–4) circulating around the world. Using PF-429242, an active-site-directed inhibitor of SKI-1/S1P, we demonstrate that inhibition of SKI-1/S1P enzymatic activity in human hepatoma Huh-7.5.1 cells results in a robust reduction of the LD numbers and LD-positive areas and provides a means of effectively inhibiting infection by DENV (1–4). Pre-treatment of Huh-7.5.1 cells with PF-429242 results in a dose-dependent inhibition of DENV infection [median inhibitory dose (EC50) = 1.2 microM; median cytotoxic dose (CC50) = 81 microM; selectivity index (SI) = 68)] and a ~3-log decrease in DENV-2 titer with 20 microM of PF-429242. Post-treatment of DENV-2 infected Huh-7.5.1 cells with PF-429242 does not affect viral RNA abundance, but it does compromise the assembly and/or release of infectious virus particles. PF-429242 antiviral activity is reversed by exogenous oleic acid, which acts as an inducer of LD formation in PF-429242-treated and non-treated control cells. Collectively, our results demonstrate that human SKI-1/S1P is a potential target for indirect-acting pan-serotypic anti-DENV agents and reveal new therapeutic opportunities associated with the use of lipid-modulating drugs for controlling DENV infection.
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17
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Kang H, Aryal A C S, Marini JC. Osteogenesis imperfecta: new genes reveal novel mechanisms in bone dysplasia. Transl Res 2017; 181:27-48. [PMID: 27914223 DOI: 10.1016/j.trsl.2016.11.005] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 11/04/2016] [Accepted: 11/07/2016] [Indexed: 12/20/2022]
Abstract
Osteogenesis imperfecta (OI) is a skeletal dysplasia characterized by fragile bones and short stature and known for its clinical and genetic heterogeneity which is now understood as a collagen-related disorder. During the last decade, research has made remarkable progress in identifying new OI-causing genes and beginning to understand the intertwined molecular and biochemical mechanisms of their gene products. Most cases of OI have dominant inheritance. Each new gene for recessive OI, and a recently identified gene for X-linked OI, has shed new light on its (often previously unsuspected) function in bone biology. Here, we summarize the literature that has contributed to our current understanding of the pathogenesis of OI.
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Affiliation(s)
- Heeseog Kang
- Section on Heritable Disorders of Bone and Extracellular Matrix, NICHD, NIH, Bethesda, Md
| | - Smriti Aryal A C
- Section on Heritable Disorders of Bone and Extracellular Matrix, NICHD, NIH, Bethesda, Md
| | - Joan C Marini
- Section on Heritable Disorders of Bone and Extracellular Matrix, NICHD, NIH, Bethesda, Md.
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18
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Duan X, Rai MF, Holguin N, Silva MJ, Patra D, Liao W, Sandell LJ. Early changes in the knee of healer and non-healer mice following non-invasive mechanical injury. J Orthop Res 2017; 35:524-536. [PMID: 27591401 PMCID: PMC5718184 DOI: 10.1002/jor.23413] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 04/20/2016] [Indexed: 02/04/2023]
Abstract
In this study, we examined early time-dependent changes in articular cartilage and synovium in response to tibial compression and sought the plausible origin of cells that respond to compression in the healer (LGXSM-6) and non-healer (LGXSM-33) recombinant inbred mouse strains. The right knee of 13-week old male mice was subjected to tibial compression using 9N axial loading. The contralateral left knee served as a control. Knees were harvested at 5, 9, and 14 days post-injury. Histological changes in cartilage and synovium, immunofluorescence pattern of CD44, aggrecan, type-II collagen, cartilage oligomeric matrix protein and the aggrecan neo-epitope NITEGE, and cell apoptosis (by TUNEL) were examined. We used a double nucleoside analog cell-labeling strategy to trace cells responsive to injury. We showed that tibial compression resulted in rupture of anterior cruciate ligament, cartilage matrix loss and chondrocyte apoptosis at the injury site. LGXSM-33 showed higher synovitis and ectopic synovial chondrogenesis than LGXSM-6 with no differences for articular cartilage lesions. With loading, an altered pattern of CD44 and NITEGE was observed: cells in the impacted area underwent apoptosis, cells closely surrounding the injured area expressed CD44, and cells in the intact area expressed NITEGE. Cells responding to injury were found in the synovium, subchondral bone marrow and the Groove of Ranvier. Taken together, we found no strain differences in chondrocytes in the early response to injury. However, the synovial response was greater in LGXSM-33 indicating that, at early time points, there is a genetic difference in synovial cell reaction to injury. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:524-536, 2017.
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Affiliation(s)
- Xin Duan
- Department of Orthopaedic Surgery, Musculoskeletal Research Center, Washington University School of Medicine at Barnes-Jewish Hospital, 425 S. Euclid Ave. MS 8233, St. Louis, Missouri 63110
- First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Muhammad Farooq Rai
- Department of Orthopaedic Surgery, Musculoskeletal Research Center, Washington University School of Medicine at Barnes-Jewish Hospital, 425 S. Euclid Ave. MS 8233, St. Louis, Missouri 63110
| | - Nilsson Holguin
- Department of Orthopaedic Surgery, Musculoskeletal Research Center, Washington University School of Medicine at Barnes-Jewish Hospital, 425 S. Euclid Ave. MS 8233, St. Louis, Missouri 63110
- Department of Biomedical Engineering, Washington University in St. Louis at Engineering and Applied Sciences, Whitaker Hall, MS 1097, St. Louis, Missouri 63130
| | - Matthew J. Silva
- Department of Orthopaedic Surgery, Musculoskeletal Research Center, Washington University School of Medicine at Barnes-Jewish Hospital, 425 S. Euclid Ave. MS 8233, St. Louis, Missouri 63110
- Department of Biomedical Engineering, Washington University in St. Louis at Engineering and Applied Sciences, Whitaker Hall, MS 1097, St. Louis, Missouri 63130
| | - Debabrata Patra
- Department of Orthopaedic Surgery, Musculoskeletal Research Center, Washington University School of Medicine at Barnes-Jewish Hospital, 425 S. Euclid Ave. MS 8233, St. Louis, Missouri 63110
| | - Weiming Liao
- First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Linda J. Sandell
- Department of Orthopaedic Surgery, Musculoskeletal Research Center, Washington University School of Medicine at Barnes-Jewish Hospital, 425 S. Euclid Ave. MS 8233, St. Louis, Missouri 63110
- Department of Biomedical Engineering, Washington University in St. Louis at Engineering and Applied Sciences, Whitaker Hall, MS 1097, St. Louis, Missouri 63130
- Department of Cell Biology and Physiology, Washington University School of Medicine at Barnes-Jewish Hospital, 425 S. Euclid Ave. MS 8233, St. Louis, Missouri 63110
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19
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Liu CF, Samsa WE, Zhou G, Lefebvre V. Transcriptional control of chondrocyte specification and differentiation. Semin Cell Dev Biol 2016; 62:34-49. [PMID: 27771362 DOI: 10.1016/j.semcdb.2016.10.004] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 10/18/2016] [Indexed: 12/20/2022]
Abstract
A milestone in the evolutionary emergence of vertebrates was the invention of cartilage, a tissue that has key roles in modeling, protecting and complementing the bony skeleton. Cartilage is elaborated and maintained by chondrocytes. These cells derive from multipotent skeletal progenitors and they perform highly specialized functions as they proceed through sequential lineage commitment and differentiation steps. They form cartilage primordia, the primary skeleton of the embryo. They then transform these primordia either into cartilage growth plates, temporary drivers of skeletal elongation and endochondral ossification, or into permanent tissues, namely articular cartilage. Chondrocyte fate decisions and differentiated activities are controlled by numerous extrinsic and intrinsic cues, and they are implemented at the gene expression level by transcription factors. The latter are the focus of this review. Meritorious efforts from many research groups have led over the last two decades to the identification of dozens of key chondrogenic transcription factors. These regulators belong to all types of transcription factor families. Some have master roles at one or several differentiation steps. They include SOX9 and RUNX2/3. Others decisively assist or antagonize the activities of these masters. They include TWIST1, SOX5/6, and MEF2C/D. Many more have tissue-patterning roles and regulate cell survival, proliferation and the pace of cell differentiation. They include, but are not limited to, homeodomain-containing proteins and growth factor signaling mediators. We here review current knowledge of all these factors, one superclass, class, and family at a time. We then compile all knowledge into transcriptional networks. We also identify remaining gaps in knowledge and directions for future research to fill these gaps and thereby provide novel insights into cartilage disease mechanisms and treatment options.
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Affiliation(s)
- Chia-Feng Liu
- Department of Cellular and Molecular Medicine, Cleveland Clinic Lerner Research Institute, Cleveland, OH, 44195, USA.
| | - William E Samsa
- Department of Orthopaedics, Case Western Reserve University, Cleveland, OH, USA
| | - Guang Zhou
- Department of Orthopaedics, Case Western Reserve University, Cleveland, OH, USA; Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH, USA; Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, USA
| | - Véronique Lefebvre
- Department of Cellular and Molecular Medicine, Cleveland Clinic Lerner Research Institute, Cleveland, OH, 44195, USA.
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20
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Lindert U, Cabral WA, Ausavarat S, Tongkobpetch S, Ludin K, Barnes AM, Yeetong P, Weis M, Krabichler B, Srichomthong C, Makareeva EN, Janecke AR, Leikin S, Röthlisberger B, Rohrbach M, Kennerknecht I, Eyre DR, Suphapeetiporn K, Giunta C, Marini JC, Shotelersuk V. MBTPS2 mutations cause defective regulated intramembrane proteolysis in X-linked osteogenesis imperfecta. Nat Commun 2016; 7:11920. [PMID: 27380894 PMCID: PMC4935805 DOI: 10.1038/ncomms11920] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 05/12/2016] [Indexed: 11/09/2022] Open
Abstract
Osteogenesis imperfecta (OI) is a collagen-related bone dysplasia. We identified an X-linked recessive form of OI caused by defects in MBTPS2, which encodes site-2 metalloprotease (S2P). MBTPS2 missense mutations in two independent kindreds with moderate/severe OI cause substitutions at highly conserved S2P residues. Mutant S2P has normal stability, but impaired functioning in regulated intramembrane proteolysis (RIP) of OASIS, ATF6 and SREBP transcription factors, consistent with decreased proband secretion of type I collagen. Further, hydroxylation of the collagen lysine residue (K87) critical for crosslinking is reduced in proband bone tissue, consistent with decreased lysyl hydroxylase 1 in proband osteoblasts. Reduced collagen crosslinks presumptively undermine bone strength. Also, proband osteoblasts have broadly defective differentiation. These mutations provide evidence that RIP plays a fundamental role in normal bone development. Osteogenesis imperfecta (OI) is genetically linked to autosomal dominant or autosomal recessive mutations. Here, Marini et al. describe two families with X-chromosome-linked OI with mutations in MBTPS2 that alter regulated intramembrane proteolysis and subsequent defects in collagen crosslinking and osteoblast function.
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Affiliation(s)
- Uschi Lindert
- Division of Metabolism, Connective Tissue Unit and Children's Research Center, University Children's Hospital Zurich, Zurich 8032, Switzerland
| | - Wayne A Cabral
- Section on Heritable Disorders of Bone and Extracellular Matrix, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Surasawadee Ausavarat
- Center of Excellence for Medical Genetics, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand.,Excellence Center for Medical Genetics, King Chulalongkorn Memorial Hospital, The Thai Red Cross Society, Bangkok 10330, Thailand
| | - Siraprapa Tongkobpetch
- Center of Excellence for Medical Genetics, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand.,Excellence Center for Medical Genetics, King Chulalongkorn Memorial Hospital, The Thai Red Cross Society, Bangkok 10330, Thailand
| | - Katja Ludin
- Center for Laboratory Medicine, Department of Medical Genetics, Kantonsspital Aarau, Aarau 5001, Switzerland
| | - Aileen M Barnes
- Section on Heritable Disorders of Bone and Extracellular Matrix, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Patra Yeetong
- Center of Excellence for Medical Genetics, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand.,Excellence Center for Medical Genetics, King Chulalongkorn Memorial Hospital, The Thai Red Cross Society, Bangkok 10330, Thailand
| | - Maryann Weis
- Department of Orthopedics and Sports Medicine, University of Washington, Seattle, Washington 98195, USA
| | - Birgit Krabichler
- Division of Human Genetics, Medical University of Innsbruck, Innsbruck 6020, Austria
| | - Chalurmpon Srichomthong
- Center of Excellence for Medical Genetics, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand.,Excellence Center for Medical Genetics, King Chulalongkorn Memorial Hospital, The Thai Red Cross Society, Bangkok 10330, Thailand
| | - Elena N Makareeva
- Section on Physical Biochemistry, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Andreas R Janecke
- Division of Human Genetics, Medical University of Innsbruck, Innsbruck 6020, Austria.,Department of Pediatrics I, Medical University of Innsbruck, Innsbruck 6020, Austria
| | - Sergey Leikin
- Section on Physical Biochemistry, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Benno Röthlisberger
- Center for Laboratory Medicine, Department of Medical Genetics, Kantonsspital Aarau, Aarau 5001, Switzerland
| | - Marianne Rohrbach
- Division of Metabolism, Connective Tissue Unit and Children's Research Center, University Children's Hospital Zurich, Zurich 8032, Switzerland
| | - Ingo Kennerknecht
- Institute of Human Genetics, Westfälische Wilhelms University, Münster 48149, Germany
| | - David R Eyre
- Department of Orthopedics and Sports Medicine, University of Washington, Seattle, Washington 98195, USA
| | - Kanya Suphapeetiporn
- Center of Excellence for Medical Genetics, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand.,Excellence Center for Medical Genetics, King Chulalongkorn Memorial Hospital, The Thai Red Cross Society, Bangkok 10330, Thailand
| | - Cecilia Giunta
- Division of Metabolism, Connective Tissue Unit and Children's Research Center, University Children's Hospital Zurich, Zurich 8032, Switzerland
| | - Joan C Marini
- Section on Heritable Disorders of Bone and Extracellular Matrix, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Vorasuk Shotelersuk
- Center of Excellence for Medical Genetics, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand.,Excellence Center for Medical Genetics, King Chulalongkorn Memorial Hospital, The Thai Red Cross Society, Bangkok 10330, Thailand
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21
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Kawai M, Liu N, Hattori T, Kataoka YH, Takigawa M, Kubota S, Yamamoto T, Ohura K. Sorcin Expression in the Epiphyseal Growth Plates of Mice. J HARD TISSUE BIOL 2016. [DOI: 10.2485/jhtb.25.57] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Mariko Kawai
- Department of Pharmacology, Osaka Dental University
- Department of Oral Morphology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences
| | - Ning Liu
- Department of Oral Morphology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences
- Central Laboratory, The Second Hospital of Jilin University
| | - Takako Hattori
- Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences
| | - Yo-Hei Kataoka
- Department of Oral Morphology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences
| | - Masaharu Takigawa
- Advanced Research Center for Oral and Craniofacial Sciences, Okayama University
| | - Satoshi Kubota
- Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences
| | - Toshio Yamamoto
- Department of Oral Morphology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences
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22
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Gorski JP, Huffman NT, Vallejo J, Brotto L, Chittur SV, Breggia A, Stern A, Huang J, Mo C, Seidah NG, Bonewald L, Brotto M. Deletion of Mbtps1 (Pcsk8, S1p, Ski-1) Gene in Osteocytes Stimulates Soleus Muscle Regeneration and Increased Size and Contractile Force with Age. J Biol Chem 2015; 291:4308-22. [PMID: 26719336 DOI: 10.1074/jbc.m115.686626] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Indexed: 12/28/2022] Open
Abstract
Conditional deletion of Mbtps1 (cKO) protease in bone osteocytes leads to an age-related increase in mass (12%) and in contractile force (30%) in adult slow twitch soleus muscles (SOL) with no effect on fast twitch extensor digitorum longus muscles. Surprisingly, bone from 10-12-month-old cKO animals was indistinguishable from controls in size, density, and morphology except for a 25% increase in stiffness. cKO SOL exhibited increased expression of Pax7, Myog, Myod1, Notch, and Myh3 and 6-fold more centralized nuclei, characteristics of postnatal regenerating muscle, but only in type I myosin heavy chain-expressing cells. Increased expression of gene pathways mediating EGF receptor signaling, circadian exercise, striated muscle contraction, and lipid and carbohydrate oxidative metabolism were also observed in cKO SOL. This muscle phenotype was not observed in 3-month-old mice. Although Mbtps1 mRNA and protein expression was reduced in cKO bone osteocytes, no differences in Mbtps1 or cre recombinase expression were observed in cKO SOL, explaining this age-related phenotype. Understanding bone-muscle cross-talk may provide a fresh and novel approach to prevention and treatment of age-related muscle loss.
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Affiliation(s)
- Jeff P Gorski
- From the Department of Oral and Craniofacial Sciences, University of Missouri-Kansas City Center of Excellence in the Study of Dental and Musculoskeletal Tissues, School of Dentistry,
| | - Nichole T Huffman
- From the Department of Oral and Craniofacial Sciences, University of Missouri-Kansas City Center of Excellence in the Study of Dental and Musculoskeletal Tissues, School of Dentistry
| | - Julian Vallejo
- Muscle Biology Research Group, School of Nursing and Health Studies, and
| | - Leticia Brotto
- Muscle Biology Research Group, School of Nursing and Health Studies, and
| | - Sridar V Chittur
- Center for Functional Genomics, University at Albany, Rensselaer, New York 12144
| | | | - Amber Stern
- School of Computing and Engineering, University of Missouri-Kansas City, Kansas City, Missouri 64108, Engineering Systems, Inc., Charlotte, North Carolina 28277, and
| | - Jian Huang
- Muscle Biology Research Group, School of Nursing and Health Studies, and
| | - Chenglin Mo
- Muscle Biology Research Group, School of Nursing and Health Studies, and
| | - Nabil G Seidah
- Institut de Recherches Cliniques Montreal, Montreal, Quebec H2W IR7, Canada
| | - Lynda Bonewald
- From the Department of Oral and Craniofacial Sciences, University of Missouri-Kansas City Center of Excellence in the Study of Dental and Musculoskeletal Tissues, School of Dentistry
| | - Marco Brotto
- Muscle Biology Research Group, School of Nursing and Health Studies, and
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23
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Kung LHW, Rajpar MH, Preziosi R, Briggs MD, Boot-Handford RP. Increased classical endoplasmic reticulum stress is sufficient to reduce chondrocyte proliferation rate in the growth plate and decrease bone growth. PLoS One 2015; 10:e0117016. [PMID: 25693198 PMCID: PMC4334961 DOI: 10.1371/journal.pone.0117016] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 12/17/2014] [Indexed: 01/14/2023] Open
Abstract
Mutations in genes encoding cartilage oligomeric matrix protein and matrilin-3 cause a spectrum of chondrodysplasias called multiple epiphyseal dysplasia (MED) and pseudoachondroplasia (PSACH). The majority of these diseases feature classical endoplasmic reticulum (ER) stress and activation of the unfolded protein response (UPR) as a result of misfolding of the mutant protein. However, the importance and the pathological contribution of ER stress in the disease pathogenesis are unknown. The aim of this study was to investigate the generic role of ER stress and the UPR in the pathogenesis of these diseases. A transgenic mouse line (ColIITgcog) was generated using the collagen II promoter to drive expression of an ER stress-inducing protein (Tgcog) in chondrocytes. The skeletal and histological phenotypes of these ColIITgcog mice were characterised. The expression and intracellular retention of Tgcog induced ER stress and activated the UPR as characterised by increased BiP expression, phosphorylation of eIF2α and spliced Xbp1. ColIITgcog mice exhibited decreased long bone growth and decreased chondrocyte proliferation rate. However, there was no disruption of chondrocyte morphology or growth plate architecture and perturbations in apoptosis were not apparent. Our data demonstrate that the targeted induction of ER stress in chondrocytes was sufficient to reduce the rate of bone growth, a key clinical feature associated with MED and PSACH, in the absence of any growth plate dysplasia. This study establishes that classical ER stress is a pathogenic factor that contributes to the disease mechanism of MED and PSACH. However, not all the pathological features of MED and PSACH were recapitulated, suggesting that a combination of intra- and extra-cellular factors are likely to be responsible for the disease pathology as a whole.
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Affiliation(s)
- Louise H. W. Kung
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, The University of Manchester, Manchester, United Kingdom
| | - M. Helen Rajpar
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, The University of Manchester, Manchester, United Kingdom
| | - Richard Preziosi
- Environment, Ecology and Evolution Research Group, Faculty of Life Sciences, The University of Manchester, Manchester, United Kingdom
| | - Michael D. Briggs
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Central Parkway, Newcastle Upon Tyne, United Kingdom
| | - Raymond P. Boot-Handford
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, The University of Manchester, Manchester, United Kingdom
- * E-mail:
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24
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Achilleos A, Huffman NT, Marcinkiewicyz E, Seidah NG, Chen Q, Dallas SL, Trainor PA, Gorski JP. MBTPS1/SKI-1/S1P proprotein convertase is required for ECM signaling and axial elongation during somitogenesis and vertebral development†. Hum Mol Genet 2015; 24:2884-98. [PMID: 25652402 DOI: 10.1093/hmg/ddv050] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 02/02/2015] [Indexed: 11/15/2022] Open
Abstract
Caudal regression syndrome (sacral agenesis), which impairs development of the caudal region of the body, occurs with a frequency of about 2 live births per 100 000 newborns although this incidence rises to 1 in 350 infants born to mothers with gestational diabetes. The lower back and limbs can be affected as well as the genitourinary and gastrointestinal tracts. The axial skeleton is formed during embryogenesis through the process of somitogenesis in which the paraxial mesoderm periodically segments into bilateral tissue blocks, called somites. Somites are the precursors of vertebrae and associated muscle, tendons and dorsal dermis. Vertebral anomalies in caudal regression syndrome may arise through perturbation of somitogenesis or, alternatively, could result from defective bone formation and patterning. We discovered that MBTPS1/SKI-1/S1P, which proteolytically activates a class of transmembrane transcription factors, plays a critical role in somitogenesis and the pathogenesis of lumbar/sacral vertebral anomalies. Conditional deletion of Mbtps1 yields a viable mouse with misshapen, fused and reduced number of lumbar and sacral vertebrae, under-developed hind limb bones and a kinky, shortened tail. We show that Mbtps1 is required to (i) maintain the Fgf8 'wavefront' in the presomitic mesoderm that underpins axial elongation, (ii) sustain the Lfng oscillatory 'clock' activity that governs the periodicity of somite formation and (iii) preserve the composition and character of the somitic extracellular matrix containing fibronectin, fibrillin2 and laminin. Based on this spinal phenotype and known functions of MBTPS1, we reason that loss-of-function mutations in Mbtps1 may cause the etiology of caudal regression syndrome.
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Affiliation(s)
| | - Nichole T Huffman
- Department of Oral and Craniofacial Sciences and the UMKC Center of Excellence in the Study of Dental and Musculoskeletal Tissues, Sch. Dentistry, University of Missouri - Kansas City, Kansas City, MO 64108, USA
| | | | - Nabil G Seidah
- Institut de Recherches Cliniques de Montréal, Montreal, Quebec H2W 1R7, Canada and
| | - Qian Chen
- Department of Oral and Craniofacial Sciences and the UMKC Center of Excellence in the Study of Dental and Musculoskeletal Tissues, Sch. Dentistry, University of Missouri - Kansas City, Kansas City, MO 64108, USA
| | - Sarah L Dallas
- Department of Oral and Craniofacial Sciences and the UMKC Center of Excellence in the Study of Dental and Musculoskeletal Tissues, Sch. Dentistry, University of Missouri - Kansas City, Kansas City, MO 64108, USA
| | - Paul A Trainor
- Stowers Institute for Medical Research, Kansas City, MO, USA, Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Jeff P Gorski
- Department of Oral and Craniofacial Sciences and the UMKC Center of Excellence in the Study of Dental and Musculoskeletal Tissues, Sch. Dentistry, University of Missouri - Kansas City, Kansas City, MO 64108, USA,
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25
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Patra D, DeLassus E, Liang G, Sandell LJ. Cartilage-specific ablation of site-1 protease in mice results in the endoplasmic reticulum entrapment of type IIb procollagen and down-regulation of cholesterol and lipid homeostasis. PLoS One 2014; 9:e105674. [PMID: 25147951 PMCID: PMC4141819 DOI: 10.1371/journal.pone.0105674] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Accepted: 07/25/2014] [Indexed: 12/13/2022] Open
Abstract
The proprotein convertase site-1 protease (S1P) converts latent ER-membrane bound transcription factors SREBPs and ATF6 to their active forms. SREBPs are involved in cholesterol and fatty acid homeostasis whereas ATF6 is involved in unfolded protein response pathways (UPR). Cartilage-specific ablation of S1P in mice (S1Pcko) results in abnormal cartilage devoid of type II collagen protein (Col II). S1Pcko mice also lack endochondral bone development. To analyze S1Pcko cartilage we performed double-labeled immunofluorescence studies for matrix proteins that demonstrated that type IIB procollagen is trapped inside the ER in S1Pcko chondrocytes. This retention is specific to type IIB procollagen; other cartilage proteins such as type IIA procollagen, cartilage oligomeric matrix protein (COMP) and aggrecan are not affected. The S1Pcko cartilage thus exhibits COMP-, aggrecan-, and type IIA procollagen-derived matrices but is characterized by the absence of a type IIB procollagen-derived matrix. To understand the molecular reason behind S1Pcko phenotypes we performed genome-wide transcriptional profiling of cartilage isolated from S1Pcko and wild type littermates. While the UPR pathways are unaffected, the SREBPs-directed cholesterol and fatty acid pathways are significantly down-regulated in S1Pcko chondrocytes, with maximal down-regulation of the stearoyl-CoA desaturase-1 (Scd1) gene. However, mouse models that lack Scd1 or exhibit reduction in lipid homeostasis do not suffer from the ER retention of Col II or lack endochondral bone. These studies indicate an indispensable role for S1P in type IIB procollagen trafficking from the ER. This role appears not to be related to lipid pathways or other current known functions of S1P and is likely dependent on additional, yet unknown, S1P substrates in chondrocytes.
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Affiliation(s)
- Debabrata Patra
- Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Elizabeth DeLassus
- Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Guosheng Liang
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Linda J. Sandell
- Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
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26
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Patterson SE, Dealy CN. Mechanisms and models of endoplasmic reticulum stress in chondrodysplasia. Dev Dyn 2014; 243:875-93. [DOI: 10.1002/dvdy.24131] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 03/10/2014] [Accepted: 03/17/2014] [Indexed: 12/14/2022] Open
Affiliation(s)
- Sara E. Patterson
- Center for Regenerative Medicine and Skeletal Development; Department of Reconstructive Sciences; University of Connecticut Health Center; Farmington Connecticut
| | - Caroline N. Dealy
- Center for Regenerative Medicine and Skeletal Development; Department of Reconstructive Sciences; University of Connecticut Health Center; Farmington Connecticut
- Center for Regenerative Medicine and Skeletal Development; Department of Orthopedic Surgery; University of Connecticut Health Center; Farmington Connecticut
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27
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Turpeinen H, Ortutay Z, Pesu M. Genetics of the first seven proprotein convertase enzymes in health and disease. Curr Genomics 2014; 14:453-67. [PMID: 24396277 PMCID: PMC3867721 DOI: 10.2174/1389202911314050010] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Revised: 09/13/2013] [Accepted: 09/14/2013] [Indexed: 12/16/2022] Open
Abstract
Members of the substilisin/kexin like proprotein convertase (PCSK) protease family cleave and convert immature pro-proteins into their biologically active forms. By cleaving for example prohormones, cytokines and cell membrane proteins, PCSKs participate in maintaining the homeostasis in a healthy human body. Conversely, erratic enzymatic function is thought to contribute to the pathogenesis of a wide variety of diseases, including obesity and hypercholestrolemia. The first characterized seven PCSK enzymes (PCSK1-2, FURIN, PCSK4-7) process their substrates at a motif made up of paired basic amino acid residues. This feature results in a variable degree of biochemical redundancy in vitro, and consequently, shared substrate molecules between the different PCSK enzymes. This redundancy has confounded our understanding of the specific biological functions of PCSKs. The physiological roles of these enzymes have been best illustrated by the phenotypes of genetically engineered mice and patients that carry mutations in the PCSK genes. Recent developments in genome-wide methodology have generated a large amount of novel information on the genetics of the first seven proprotein convertases. In this review we summarize the reported genetic alterations and their associated phenotypes.
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Affiliation(s)
- Hannu Turpeinen
- Immunoregulation, Institute of Biomedical Technology, University of Tampere, and BioMediTech, Tampere, Finland
| | - Zsuzsanna Ortutay
- Immunoregulation, Institute of Biomedical Technology, University of Tampere, and BioMediTech, Tampere, Finland
| | - Marko Pesu
- Immunoregulation, Institute of Biomedical Technology, University of Tampere, and BioMediTech, Tampere, Finland; ; Fimlab laboratories, Pirkanmaa Hospital District, Finland
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28
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Neacsu CD, Ko YP, Tagariello A, Røkenes Karlsen K, Neiss WF, Paulsson M, Wagener R. Matrilin-1 is essential for zebrafish development by facilitating collagen II secretion. J Biol Chem 2013; 289:1505-18. [PMID: 24293366 DOI: 10.1074/jbc.m113.529933] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Matrilin-1 is the prototypical member of the matrilin protein family and is highly expressed in cartilage. However, gene targeting of matrilin-1 in mouse did not lead to pronounced phenotypes. Here we used the zebrafish as an alternative model to study matrilin function in vivo. Matrilin-1 displays a multiphasic expression during zebrafish development. In an early phase, with peak expression at about 15 h post-fertilization, matrilin-1 is present throughout the zebrafish embryo with exception of the notochord. Later, when the skeleton develops, matrilin-1 is expressed mainly in cartilage. Morpholino knockdown of matrilin-1 results both in overall growth defects and in disturbances in the formation of the craniofacial cartilage, most prominently loss of collagen II deposition. In fish with mild phenotypes, certain cartilage extracellular matrix components were present, but the tissue did not show features characteristic for cartilage. The cells showed endoplasmic reticulum aberrations but no activation of XBP-1, a marker for endoplasmic reticulum stress. In severe phenotypes nearly all chondrocytes died. During the early expression phase the matrilin-1 knockdown had no effects on cell morphology, but increased cell death was observed. In addition, the broad deposition of collagen II was largely abolished. Interestingly, the early phenotype could be rescued by the co-injection of mRNA coding for the von Willebrand factor C domain of collagen IIα1a, indicating that the functional loss of this domain occurs as a consequence of matrilin-1 deficiency. The results show that matrilin-1 is indispensible for zebrafish cartilage formation and plays a role in the early collagen II-dependent developmental events.
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29
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Turpeinen H, Oksanen A, Kivinen V, Kukkurainen S, Uusimäki A, Rämet M, Parikka M, Hytönen VP, Nykter M, Pesu M. Proprotein convertase subtilisin/kexin type 7 (PCSK7) is essential for the zebrafish development and bioavailability of transforming growth factor β1a (TGFβ1a). J Biol Chem 2013; 288:36610-23. [PMID: 24178295 DOI: 10.1074/jbc.m113.453183] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Proprotein convertase subtilisin/kexin (PCSK) enzymes convert proproteins into bioactive end products. Although other PCSK enzymes are known to be essential for biological processes ranging from cholesterol metabolism to host defense, the in vivo importance of the evolutionarily ancient PCSK7 has remained enigmatic. Here, we quantified the expressions of all pcsk genes during the 1st week of fish development and in several tissues. pcsk7 expression was ubiquitous and evident already during the early development. To compare mammalian and zebrafish PCSK7, we prepared homology models, which demonstrated remarkable structural conservation. When the PCSK7 function in developing larvae was inhibited, we found that PCSK7-deficient fish have defects in various organs, including the brain, eye, and otic vesicle, and these result in mortality within 7 days postfertilization. A genome-wide analysis of PCSK7-dependent gene expression showed that, in addition to developmental processes, several immune system-related pathways are also regulated by PCSK7. Specifically, the PCSK7 contributed to the mRNA expression and proteolytic cleavage of the cytokine TGFβ1a. Consequently, tgfβ1a morphant fish displayed phenotypical similarities with pcsk7 morphants, underscoring the importance of this cytokine in the zebrafish development. Targeting PCSK activity has emerged as a strategy for treating human diseases. Our results suggest that inhibiting PCSK7 might interfere with normal vertebrate development.
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30
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Zhang J, Weng Y, Liu X, Wang J, Zhang W, Kim SH, Zhang H, Li R, Kong Y, Chen X, Shui W, Wang N, Zhao C, Wu N, He Y, Nan G, Chen X, Wen S, Zhang H, Deng F, Wan L, Luu HH, Haydon RC, Shi LL, He TC, Shi Q. Endoplasmic reticulum (ER) stress inducible factor cysteine-rich with EGF-like domains 2 (Creld2) is an important mediator of BMP9-regulated osteogenic differentiation of mesenchymal stem cells. PLoS One 2013; 8:e73086. [PMID: 24019898 PMCID: PMC3760886 DOI: 10.1371/journal.pone.0073086] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2013] [Accepted: 07/15/2013] [Indexed: 01/08/2023] Open
Abstract
Mesenchymal stem cells (MSCs) are multipotent progenitors that can undergo osteogenic differentiation under proper stimuli. We demonstrated that BMP9 is one of the most osteogenic BMPs. However, the molecular mechanism underlying BMP9-initiated osteogenic signaling in MSCs remains unclear. Through gene expression profiling analysis we identified several candidate mediators of BMP9 osteogenic signaling. Here, we focus on one such signaling mediator and investigate the functional role of cysteine-rich with EGF-like domains 2 (Creld2) in BMP9-initiated osteogenic signaling. Creld2 was originally identified as an ER stress-inducible factor localized in the ER-Golgi apparatus. Our genomewide expression profiling analysis indicates that Creld2 is among the top up-regulated genes in BMP9-stimulated MSCs. We confirm that Creld2 is up-regulated by BMP9 in MSCs. ChIP analysis indicates that Smad1/5/8 directly binds to the Creld2 promoter in a BMP9-dependent fashion. Exogenous expression of Creld2 in MSCs potentiates BMP9-induced early and late osteogenic markers, and matrix mineralization. Conversely, silencing Creld2 expression inhibits BMP9-induced osteogenic differentiation. In vivo stem cell implantation assay reveals that exogenous Creld2 promotes BMP9-induced ectopic bone formation and matrix mineralization, whereas silencing Creld2 expression diminishes BMP9-induced bone formation and matrix mineralization. We further show that Creld2 is localized in ER and the ER stress inducers potentiate BMP9-induced osteogenic differentiation. Our results strongly suggest that Creld2 may be directly regulated by BMP9 and ER stress response may play an important role in regulating osteogenic differentiation.
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Affiliation(s)
- Jiye Zhang
- Ministry of Education Key Laboratory of Diagnostic Medicine and the Affiliated Hospitals of Chongqing Medical University, Chongqing, China
| | - Yaguang Weng
- Ministry of Education Key Laboratory of Diagnostic Medicine and the Affiliated Hospitals of Chongqing Medical University, Chongqing, China
| | - Xing Liu
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery, The University of Chicago Medical Center, Chicago, Illinois, United States of America
- Stem Cell Biology and Therapy Laboratory of the Key Laboratory for Pediatrics co-designated by Chinese Ministry of Education and Chongqing Bureau of Education, The Children’s Hospital of Chongqing Medical University, Chongqing, China
| | - Jinhua Wang
- Ministry of Education Key Laboratory of Diagnostic Medicine and the Affiliated Hospitals of Chongqing Medical University, Chongqing, China
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery, The University of Chicago Medical Center, Chicago, Illinois, United States of America
| | - Wenwen Zhang
- Ministry of Education Key Laboratory of Diagnostic Medicine and the Affiliated Hospitals of Chongqing Medical University, Chongqing, China
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery, The University of Chicago Medical Center, Chicago, Illinois, United States of America
| | - Stephanie H. Kim
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery, The University of Chicago Medical Center, Chicago, Illinois, United States of America
| | - Hongyu Zhang
- Ministry of Education Key Laboratory of Diagnostic Medicine and the Affiliated Hospitals of Chongqing Medical University, Chongqing, China
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery, The University of Chicago Medical Center, Chicago, Illinois, United States of America
| | - Ruidong Li
- Ministry of Education Key Laboratory of Diagnostic Medicine and the Affiliated Hospitals of Chongqing Medical University, Chongqing, China
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery, The University of Chicago Medical Center, Chicago, Illinois, United States of America
| | - Yuhan Kong
- Ministry of Education Key Laboratory of Diagnostic Medicine and the Affiliated Hospitals of Chongqing Medical University, Chongqing, China
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery, The University of Chicago Medical Center, Chicago, Illinois, United States of America
| | - Xiang Chen
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery, The University of Chicago Medical Center, Chicago, Illinois, United States of America
- Department of Orthopaedic Surgery, The Affiliated Tangdu Hospital of the Fourth Military Medical University, Xi’an, China
| | - Wei Shui
- Ministry of Education Key Laboratory of Diagnostic Medicine and the Affiliated Hospitals of Chongqing Medical University, Chongqing, China
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery, The University of Chicago Medical Center, Chicago, Illinois, United States of America
| | - Ning Wang
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery, The University of Chicago Medical Center, Chicago, Illinois, United States of America
- School of Laboratory Medicine and the Affiliated Southwest Hospital of the Third Military Medical University, Chongqing, China
| | - Chen Zhao
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery, The University of Chicago Medical Center, Chicago, Illinois, United States of America
- School of Laboratory Medicine and the Affiliated Southwest Hospital of the Third Military Medical University, Chongqing, China
| | - Ningning Wu
- Ministry of Education Key Laboratory of Diagnostic Medicine and the Affiliated Hospitals of Chongqing Medical University, Chongqing, China
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery, The University of Chicago Medical Center, Chicago, Illinois, United States of America
| | - Yunfeng He
- Ministry of Education Key Laboratory of Diagnostic Medicine and the Affiliated Hospitals of Chongqing Medical University, Chongqing, China
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery, The University of Chicago Medical Center, Chicago, Illinois, United States of America
| | - Guoxin Nan
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery, The University of Chicago Medical Center, Chicago, Illinois, United States of America
- Stem Cell Biology and Therapy Laboratory of the Key Laboratory for Pediatrics co-designated by Chinese Ministry of Education and Chongqing Bureau of Education, The Children’s Hospital of Chongqing Medical University, Chongqing, China
| | - Xian Chen
- Ministry of Education Key Laboratory of Diagnostic Medicine and the Affiliated Hospitals of Chongqing Medical University, Chongqing, China
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery, The University of Chicago Medical Center, Chicago, Illinois, United States of America
| | - Sheng Wen
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery, The University of Chicago Medical Center, Chicago, Illinois, United States of America
- Stem Cell Biology and Therapy Laboratory of the Key Laboratory for Pediatrics co-designated by Chinese Ministry of Education and Chongqing Bureau of Education, The Children’s Hospital of Chongqing Medical University, Chongqing, China
| | - Hongmei Zhang
- Ministry of Education Key Laboratory of Diagnostic Medicine and the Affiliated Hospitals of Chongqing Medical University, Chongqing, China
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery, The University of Chicago Medical Center, Chicago, Illinois, United States of America
| | - Fang Deng
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery, The University of Chicago Medical Center, Chicago, Illinois, United States of America
- School of Laboratory Medicine and the Affiliated Southwest Hospital of the Third Military Medical University, Chongqing, China
| | - Lihua Wan
- Ministry of Education Key Laboratory of Diagnostic Medicine and the Affiliated Hospitals of Chongqing Medical University, Chongqing, China
| | - Hue H. Luu
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery, The University of Chicago Medical Center, Chicago, Illinois, United States of America
| | - Rex C. Haydon
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery, The University of Chicago Medical Center, Chicago, Illinois, United States of America
| | - Lewis L. Shi
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery, The University of Chicago Medical Center, Chicago, Illinois, United States of America
| | - Tong-Chuan He
- Ministry of Education Key Laboratory of Diagnostic Medicine and the Affiliated Hospitals of Chongqing Medical University, Chongqing, China
- Stem Cell Biology and Therapy Laboratory of the Key Laboratory for Pediatrics co-designated by Chinese Ministry of Education and Chongqing Bureau of Education, The Children’s Hospital of Chongqing Medical University, Chongqing, China
- * E-mail: (TCH); (QS)
| | - Qiong Shi
- Ministry of Education Key Laboratory of Diagnostic Medicine and the Affiliated Hospitals of Chongqing Medical University, Chongqing, China
- * E-mail: (TCH); (QS)
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31
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Inhibition of the prohormone convertase subtilisin-kexin isoenzyme-1 induces apoptosis in human melanoma cells. J Invest Dermatol 2013; 134:168-175. [PMID: 23884247 DOI: 10.1038/jid.2013.282] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 04/29/2013] [Accepted: 05/09/2013] [Indexed: 11/08/2022]
Abstract
Prohormone convertases (PCs) are endoproteases that process many substrates in addition to hormone precursors. Although overexpression of PCs is linked to carcinogenesis in some solid tumors, the role of subtilisin-kexin isoenzyme-1 (SKI-1) in this context is unknown. We show that SKI-1 is constitutively expressed in human pigment cells with higher SKI activity in seven out of eight melanoma cell lines compared with normal melanocytes. SKI-1 immunoreactivity is also detectable in tumor cells of melanoma metastases. Moreover, tissue samples of the latter display higher SKI-1 mRNA levels and activity than normal skin. From various stimuli tested, 12-O-tetradecanoylphorbol-13-acetate and tunicamycin affected SKI-1 expression. Importantly, SKI-1 inhibition by the cell-permeable enzyme inhibitor decanoyl-RRLL-chloromethylketone (dec-RRLL-CMK) not only suppressed proliferation and metabolic activity of melanoma cells in vitro but also reduced tumor growth of melanoma cells injected intracutaneously into immunodeficient mice. Mechanistic studies revealed that dec-RRLL-CMK induces classical apoptosis of melanoma cells in vitro and affects expression of several SKI-1 target genes including activating transcription factor 6 (ATF6). However, ATF6 gene silencing does not result in apoptosis of melanoma cells, suggesting that dec-RRLL-CMK induces cell death in an ATF6-independent manner. Our findings encourage further studies on SKI-1 as a potential target for melanoma therapy.
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32
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Seidah NG, Sadr MS, Chrétien M, Mbikay M. The multifaceted proprotein convertases: their unique, redundant, complementary, and opposite functions. J Biol Chem 2013; 288:21473-81. [PMID: 23775089 DOI: 10.1074/jbc.r113.481549] [Citation(s) in RCA: 139] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The secretory proprotein convertase (PC) family comprises nine members: PC1/3, PC2, furin, PC4, PC5/6, PACE4, PC7, SKI-1/S1P, and PCSK9. The first seven PCs cleave their substrates at single or paired basic residues, and SKI-1/S1P cleaves its substrates at non-basic residues in the Golgi. PCSK9 cleaves itself once, and the secreted inactive protease escorts specific receptors for lysosomal degradation. It regulates the levels of circulating LDL cholesterol and is considered a major therapeutic target in phase III clinical trials. In vivo, PCs exhibit unique and often essential functions during development and/or in adulthood, but certain convertases also exhibit complementary, redundant, or opposite functions.
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Affiliation(s)
- Nabil G Seidah
- Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal (IRCM, affiliated with the University of Montreal), Montreal, Quebec H2W 1R7, Canada.
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33
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Bentovim L, Amarilio R, Zelzer E. HIF1α is a central regulator of collagen hydroxylation and secretion under hypoxia during bone development. Development 2012; 139:4473-83. [PMID: 23095889 DOI: 10.1242/dev.083881] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Collagen production is fundamental for the ontogeny and the phylogeny of all multicellular organisms. It depends on hydroxylation of proline residues, a reaction that uses molecular oxygen as a substrate. This dependency is expected to limit collagen production to oxygenated cells. However, during embryogenesis, cells in different tissues that develop under low oxygen levels must produce this essential protein. In this study, using the growth plate of developing bones as a model system, we identify the transcription factor hypoxia-inducible factor 1 α (HIF1α) as a central component in a mechanism that underlies collagen hydroxylation and secretion by hypoxic cells. We show that Hif1a loss of function in growth plate chondrocytes arrests the secretion of extracellular matrix proteins, including collagen type II. Reduced collagen hydroxylation and endoplasmic reticulum stress induction in Hif1a-depleted cells suggests that HIF1α regulates collagen secretion by mediating its hydroxylation and consequently its folding. We demonstrate in vivo the ability of Hif1α to drive the transcription of collagen prolyl 4-hydroxylase, which catalyzes collagen hydroxylation. We also show that, concurrently, HIF1α maintains cellular levels of oxygen, most likely by controlling the expression of pyruvate dehydrogenase kinase 1, an inhibitor of the tricarboxylic acid cycle. Through this two-armed mechanism, HIF1α acts as a central regulator of collagen production that allows chondrocytes to maintain their function as professional secretory cells in the hypoxic growth plate. As hypoxic conditions occur also during pathological conditions such as cancer, our findings may promote the understanding not only of embryogenesis, but also of pathological processes.
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Affiliation(s)
- Lital Bentovim
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
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Kung LHW, Rajpar MH, Briggs MD, Boot-Handford RP. Hypertrophic chondrocytes have a limited capacity to cope with increases in endoplasmic reticulum stress without triggering the unfolded protein response. J Histochem Cytochem 2012; 60:734-48. [PMID: 22859705 PMCID: PMC3524565 DOI: 10.1369/0022155412458436] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Mutations causing metaphyseal chondrodysplasia type Schmid (MCDS) (e.g., Col10a1p.N617K) induce the pathology by a mechanism involving increased endoplasmic reticulum (ER) stress triggering an unfolded protein response (UPR) in hypertrophic chondrocytes (Rajpar et al. 2009). Here we correlate the expression of mutant protein with the onset of the UPR and disease pathology (hypertrophic zone [HZ] expansion) in MCDS and ColXTgcog mouse lines from E14.5 to E17.5. Embryos homozygous for the Col10a1p.N617K mutation displayed a delayed secretion of mutant collagen X accompanied by a UPR at E14.5, delayed ossification of the primary center at E15.5, and an expanded HZ at E17.5. Heterozygote embryos expressed mutant collagen X from E14.5 but exhibited no evidence of a UPR or an HZ expansion until after E17.5. Embryos positive for the ER stress-inducing ColXTgcog allele expressed Tgcog at E14.5, but the onset of the UPR was not apparent until E15.5 in homozygous and E17.5 in hemizygous embryos. Only homozygous embryos exhibited an HZ expansion at E17.5. The differential onset of the UPR and pathology, dependent on mutation type and gene dosage, indicates that hypertrophic chondrocytes have a latent capacity to deal with ER stress, which must be exceeded to trigger the UPR and HZ expansion.
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Affiliation(s)
- Louise H W Kung
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, The University of Manchester, Manchester, United Kingdom
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Seidah NG, Prat A. The biology and therapeutic targeting of the proprotein convertases. Nat Rev Drug Discov 2012; 11:367-83. [PMID: 22679642 DOI: 10.1038/nrd3699] [Citation(s) in RCA: 588] [Impact Index Per Article: 49.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The mammalian proprotein convertases constitute a family of nine secretory serine proteases that are related to bacterial subtilisin and yeast kexin. Seven of these (proprotein convertase 1 (PC1), PC2, furin, PC4, PC5, paired basic amino acid cleaving enzyme 4 (PACE4) and PC7) activate cellular and pathogenic precursor proteins by cleavage at single or paired basic residues, whereas subtilisin kexin isozyme 1 (SKI-1) and proprotein convertase subtilisin kexin 9 (PCSK9) regulate cholesterol and/or lipid homeostasis via cleavage at non-basic residues or through induced degradation of receptors. Proprotein convertases are now considered to be attractive targets for the development of powerful novel therapeutics. In this Review, we summarize the physiological functions and pathological implications of the proprotein convertases, and discuss proposed strategies to control some of their activities, including their therapeutic application and validation in selected disease states.
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Affiliation(s)
- Nabil G Seidah
- Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal (affiliated to University of Montreal), 110 Pine Ave West, Montreal, Quebec H2W 1R7, Canada.
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Hypopigmentation and maternal-zygotic embryonic lethality caused by a hypomorphic mbtps1 mutation in mice. G3-GENES GENOMES GENETICS 2012; 2:499-504. [PMID: 22540041 PMCID: PMC3337478 DOI: 10.1534/g3.112.002196] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2011] [Accepted: 02/15/2012] [Indexed: 12/28/2022]
Abstract
The site 1 protease, encoded by Mbtps1, mediates the initial cleavage of site 2 protease substrates, including sterol regulatory element binding proteins and CREB/ATF transcription factors. We demonstrate that a hypomorphic mutation of Mbtps1 called woodrat (wrt) caused hypocholesterolemia, as well as progressive hypopigmentation of the coat, that appears to be mechanistically unrelated. Hypopigmentation was rescued by transgenic expression of wild-type Mbtps1, and reciprocal grafting studies showed that normal pigmentation depended upon both cell-intrinsic or paracrine factors, as well as factors that act systemically, both of which are lacking in wrt homozygotes. Mbtps1 exhibited a maternal-zygotic effect characterized by fully penetrant embryonic lethality of maternal-zygotic wrt mutant offspring and partial embryonic lethality (~40%) of zygotic wrt mutant offspring. Mbtps1 is one of two maternal-zygotic effect genes identified in mammals to date. It functions nonredundantly in pigmentation and embryogenesis.
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Abstract
The proprotein convertases (PCs) are secretory mammalian serine proteinases related to bacterial subtilisin-like enzymes. The family of PCs comprises nine members, PC1/3, PC2, furin, PC4, PC5/6, PACE4, PC7, SKI-1/S1P, and PCSK9 (Fig. 3.1). While the first seven PCs cleave after single or paired basic residues, the last two cleave at non-basic residues and the last one PCSK9 only cleaves one substrate, itself, for its activation. The targets and substrates of these convertases are very varied covering many aspects of cellular biology and communication. While it took more than 22 years to begin to identify the first member in 1989-1990, in less than 14 years they were all characterized. So where are we 20 years later in 2011? We have now reached a level of maturity needed to begin to unravel the mechanisms behind the complex physiological functions of these PCs both in health and disease states. We are still far away from comprehensively understanding the various ramifications of their roles and to identify their physiological substrates unequivocally. How do these enzymes function in vivo? Are there other partners to be identified that would modulate their activity and/or cellular localization? Would non-toxic inhibitors/silencers of some PCs provide alternative therapies to control some pathologies and improve human health? Are there human SNPs or mutations in these PCs that correlate with disease, and can these help define the finesses of their functions and/or cellular sorting? The more we know about a given field, the more questions will arise, until we are convinced that we have cornered the important angles. And yet the future may well reserve for us many surprises that may allow new leaps in our understanding of the fascinating biology of these phylogenetically ancient eukaryotic proteases (Fig. 3.2) implicated in health and disease, which traffic through the cells via multiple sorting pathways (Fig. 3.3).
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Affiliation(s)
- Nabil G Seidah
- Biochemical Neuroendocrinology Laboratory, Clinical Research Institute of Montreal, Montreal, QC, Canada H2W 1R7.
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Mechanics of chondrocyte hypertrophy. Biomech Model Mechanobiol 2011; 11:655-64. [DOI: 10.1007/s10237-011-0340-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Accepted: 07/29/2011] [Indexed: 12/20/2022]
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Affiliation(s)
- Jin Ye
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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Marschner K, Kollmann K, Schweizer M, Braulke T, Pohl S. A key enzyme in the biogenesis of lysosomes is a protease that regulates cholesterol metabolism. Science 2011; 333:87-90. [PMID: 21719679 DOI: 10.1126/science.1205677] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Mucolipidosis II is a severe lysosomal storage disorder caused by defects in the α and β subunits of the hexameric N-acetylglucosamine-1-phosphotransferase complex essential for the formation of the mannose 6-phosphate targeting signal on lysosomal enzymes. Cleavage of the membrane-bound α/β-subunit precursor by an unknown protease is required for catalytic activity. Here we found that the α/β-subunit precursor is cleaved by the site-1 protease (S1P) that activates sterol regulatory element-binding proteins in response to cholesterol deprivation. S1P-deficient cells failed to activate the α/β-subunit precursor and exhibited a mucolipidosis II-like phenotype. Thus, S1P functions in the biogenesis of lysosomes, and lipid-independent phenotypes of S1P deficiency may be caused by lysosomal dysfunction.
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Affiliation(s)
- Katrin Marschner
- Department of Biochemistry, Children's Hospital, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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Patra D, DeLassus E, Hayashi S, Sandell LJ. Site-1 protease is essential to growth plate maintenance and is a critical regulator of chondrocyte hypertrophic differentiation in postnatal mice. J Biol Chem 2011; 286:29227-29240. [PMID: 21652717 DOI: 10.1074/jbc.m110.208686] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Site-1 protease (S1P) is a proprotein convertase with essential functions in lipid homeostasis and unfolded protein response pathways. We previously studied a mouse model of cartilage-specific knock-out of S1P in chondroprogenitor cells. These mice exhibited a defective cartilage matrix devoid of type II collagen protein (Col II) and displayed chondrodysplasia with no endochondral bone formation even though the molecular program for endochondral bone development appeared intact. To gain insights into S1P function, we generated and studied a mouse model in which S1P is ablated in postnatal chondrocytes. Postnatal ablation of S1P results in chondrodysplasia. However, unlike early embryonic ablations, the growth plates of these mice exhibit a lack of Ihh, PTHrP-R, and Col10 expression indicating a loss of chondrocyte hypertrophic differentiation and thus disruption of the molecular program required for endochondral bone development. S1P ablation results in rapid growth plate disruption due to intracellular Col II entrapment concomitant with loss of chondrocyte hypertrophy suggesting that these two processes are related. Entrapment of Col II in the chondrocytes of the prospective secondary ossification center precludes its development. Trabecular bone formation is dramatically diminished in the primary spongiosa and is eventually lost. The primary growth plate is eradicated by apoptosis but is gradually replaced by a fully functional new growth plate from progenitor stem cells capable of supporting new bone growth. Our study thus demonstrates that S1P has fundamental roles in the preservation of postnatal growth plate through chondrocyte differentiation and Col II deposition and functions to couple growth plate maturation to trabecular bone development in growing mice.
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Affiliation(s)
- Debabrata Patra
- Department of Orthopaedic Surgery, Washington University School of Medicine at Barnes-Jewish Hospital, St. Louis, Missouri 63110.
| | - Elizabeth DeLassus
- Department of Orthopaedic Surgery, Washington University School of Medicine at Barnes-Jewish Hospital, St. Louis, Missouri 63110
| | - Shinya Hayashi
- Department of Orthopaedic Surgery, Washington University School of Medicine at Barnes-Jewish Hospital, St. Louis, Missouri 63110
| | - Linda J Sandell
- Department of Orthopaedic Surgery, Washington University School of Medicine at Barnes-Jewish Hospital, St. Louis, Missouri 63110; Department of Cell Biology and Physiology, Washington University School of Medicine at Barnes-Jewish Hospital, St. Louis, Missouri 63110.
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Gorski JP. Biomineralization of bone: a fresh view of the roles of non-collagenous proteins. Front Biosci (Landmark Ed) 2011; 16:2598-621. [PMID: 21622198 DOI: 10.2741/3875] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The impact of genetics has dramatically affected our understanding of the functions of non-collagenous proteins. Specifically, mutations and knockouts have defined their cellular spectrum of actions. However, the biochemical mechanisms mediated by non-collagenous proteins in biomineralization remain elusive. It is likely that this understanding will require more focused functional testing at the protein, cell, and tissue level. Although initially viewed as rather redundant and static acidic calcium binding proteins, it is now clear that non-collagenous proteins in mineralizing tissues represent diverse entities capable of forming multiple protein-protein interactions which act in positive and negative ways to regulate the process of bone mineralization. Several new examples from the author's laboratory are provided which illustrate this theme including an apparent activating effect of hydroxyapatite crystals on metalloproteinases. This review emphasizes the view that secreted non-collagenous proteins in mineralizing bone actively participate in the mineralization process and ultimately control where and how much mineral crystal is deposited, as well as determining the quality and biomechanical properties of the mineralized matrix produced.
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Affiliation(s)
- Jeffrey Paul Gorski
- Center of Excellence in the Study of Musculoskeletal and Dental Tissues and Dept. of Oral Biology, Sch. Of Dentistry, Univ. of Missouri-Kansas City, Kansas City, MO 64108, USA.
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In vitro assay for protease activity of proprotein convertase subtilisin kexins (PCSKs): an overall review of existing and new methodologies. Methods Mol Biol 2011; 768:127-53. [PMID: 21805240 DOI: 10.1007/978-1-61779-204-5_6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The mammalian proprotein convertase subtilisin kexins (PCSKs) previously called proprotein or prohormone convertases (PCs) are a family of Ca(+2)-dependent endoproteases in the subtilisin family. These proteolytic enzymes exert their many crucial physiological and biological functions in vivo via their ability to cleave larger inactive precursor proteins into their biologically active mature forms. This event takes place in a highly efficient and selective manner. Such actions of PCSKs either alone or in combination to cleave specific protein bonds are the hallmark events that not only define the normal functions and metabolism of the body but also may lead to a variety of diseases or disorders with associated conditions. These include among others, diabetes, obesity, cancer, cardiovascular diseases, reproduction abnormalities as well as viral bacterial infections. These conditions were the direct consequences of an enhanced level of enzymatic activity of one or more PCSKs except only PCSK9, whose protease activity in relation to its physiological substrate has yet to be characterized. Owing to this finding, a large number of research studies have been exclusively devoted to develop rapid, efficient and reliable in vitro methods for examining the protease activity of these enzymes. Several assays have been developed to monitor PCSK activity and these are widely used in chemical, biochemical, cellular and animal studies. This review will cover various methodologies and protocols that are currently available in the literature for PCSK activity assays. These include liquid phase methods using fluorogenic, chromogenic and intramolecularly quenched fluorescent substrates as well as a newly developed novel solid phase fluorescence method. This review will also highlight the usefulness of these methodologies and finally a comparative analysis has been made to examine their merits and demerits with some key examples.
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Gorski JP, Huffman NT, Chittur S, Midura RJ, Black C, Oxford J, Seidah NG. Inhibition of proprotein convertase SKI-1 blocks transcription of key extracellular matrix genes regulating osteoblastic mineralization. J Biol Chem 2010; 286:1836-49. [PMID: 21075843 DOI: 10.1074/jbc.m110.151647] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mineralization, a characteristic phenotypic property of osteoblastic lineage cells, was blocked by 4-(2-aminoethyl) benzenesulfonyl fluoride hydrochloride (AEBSF) and decanoyl-Arg-Arg-Leu-Leu-chloromethyl ketone (dec-RRLL-cmk), inhibitors of SKI-1 (site 1; subtilisin kexin like-1) protease. Because SKI-1 is required for activation of SREBP and CREB (cAMP-response element-binding protein)/ATF family transcription factors, we tested the effect of these inhibitors on gene expression. AEBSF decreased expression of 140 genes by 1.5-3.0-fold including Phex, Dmp1, COL1A1, COL11A1, and fibronectin. Direct comparison of AEBSF and dec-RRLL-cmk, a more specific SKI-1 inhibitor, demonstrated that expression of Phex, Dmp1, COL11A1, and fibronectin was reduced by both, whereas COL1A2 and HMGCS1 were reduced only by AEBSF. AEBSF and dec-RRLL-cmk decreased the nuclear content of SKI-1-activated forms of transcription factors SREBP-1, SREBP-2, and OASIS. In contrast to AEBSF, the actions of dec-RRLL-cmk represent the sum of its direct actions on SKI-1 and indirect actions on caspase-3. Specifically, dec-RRLL-cmk reduced intracellular caspase-3 activity by blocking the formation of activated 19-kDa caspase-3. Conversely, overexpression of SKI-1-activated SREBP-1a and CREB-H in UMR106-01 osteoblastic cells increased the number of mineralized foci and altered their morphology to yield mineralization nodules, respectively. In summary, SKI-1 regulates the activation of transmembrane transcription factor precursors required for expression of key genes required for mineralization of osteoblastic cultures in vitro and bone formation in vivo. Our results indicate that the differentiated phenotype of osteoblastic cells and possibly osteocytes depends upon the non-apoptotic actions of SKI-1.
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Affiliation(s)
- Jeff P Gorski
- Center of Excellence in the Study of Musculoskeletal and Dental Tissues and Department of Oral Biology, School of Dentistry, University of Missouri-Kansas City, Kansas City, Missouri 64108, USA.
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Tsang KY, Chan D, Bateman JF, Cheah KSE. In vivo cellular adaptation to ER stress: survival strategies with double-edged consequences. J Cell Sci 2010; 123:2145-54. [PMID: 20554893 DOI: 10.1242/jcs.068833] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Disturbances to the balance of protein synthesis, folding and secretion in the endoplasmic reticulum (ER) induce stress and thereby the ER stress signaling (ERSS) response, which alleviates this stress. In this Commentary, we review the emerging idea that ER stress caused by abnormal physiological conditions and/or mutations in genes that encode client proteins of the ER is a key factor underlying different developmental processes and the pathology of diverse diseases, including diabetes, neurodegeneration and skeletal dysplasias. Recent studies in mouse models indicate that the effect of ERSS in vivo and the nature of the cellular strategies induced to ameliorate pathological ER stress are crucial factors in determining cell fate and clinical disease features. Importantly, ERSS can affect cellular proliferation and the differentiation program; cells that survive the stress can become 'reprogrammed' or dysfunctional. These cell-autonomous adaptation strategies can generate a spectrum of context-dependent cellular consequences, ranging from recovery to death. Secondary effects can include altered cell-extracellular-matrix interactions and non-cell-autonomous alteration of paracrine signaling, which contribute to the final phenotypic outcome. Recent reports showing that ER stress can be alleviated by chemical compounds suggest the potential for novel therapeutic approaches.
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Affiliation(s)
- Kwok Yeung Tsang
- Department of Biochemistry and Centre for Reproduction, Development and Growth, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Pokfulam, Hong Kong SAR, China
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Wang Z, Bryan J, Franz C, Havlioglu N, Sandell LJ. Type IIB procollagen NH(2)-propeptide induces death of tumor cells via interaction with integrins alpha(V)beta(3) and alpha(V)beta(5). J Biol Chem 2010; 285:20806-17. [PMID: 20439458 DOI: 10.1074/jbc.m110.118521] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cartilage is resistant to tumor invasion. In the present study, we found that the NH(2)-propeptide of the cartilage-characteristic collagen, type IIB, PIIBNP, is capable of killing tumor cells. The NH(2)-propeptide is liberated into the extracellular matrix prior to deposition of the collagen fibrils. This peptide adheres to and kills cells from chondrosarcoma and cervical and breast cancer cell lines via the integrins alpha(v)beta(5) and alpha(v)beta(3). Adhesion is abrogated by blocking with anti alpha(v)beta(5) and alpha(v)beta(3) antibodies. When alpha(v) is suppressed by small intefering RNA, adhesion and cell killing are blocked. Normal chondrocytes from developing cartilage do not express alpha(v)beta(3) and alpha(v)beta(5) integrins and are thus protected from cell death. Morphological, DNA, and biochemical evidence indicates that the cell death is not by apoptosis but probably by necrosis. In an assay for invasion, PIIBNP reduced the number of cells crossing the membrane. In vivo, in a tumor model for breast cancer, PIIBNP was consistently able to reduce the size of the tumor.
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Affiliation(s)
- Zhepeng Wang
- Department of Orthopedic Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, St. Louis, MI 63110, USA
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The unfolded protein response and its relevance to connective tissue diseases. Cell Tissue Res 2009; 339:197-211. [PMID: 19851784 PMCID: PMC2784867 DOI: 10.1007/s00441-009-0877-8] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2009] [Accepted: 09/03/2009] [Indexed: 12/13/2022]
Abstract
The unfolded protein response (UPR) has evolved to counter the stresses that occur in the endoplasmic reticulum (ER) as a result of misfolded proteins. This sophisticated quality control system attempts to restore homeostasis through the action of a number of different pathways that are coordinated in the first instance by the ER stress-senor proteins IRE1, ATF6 and PERK. However, prolonged ER-stress-related UPR can have detrimental effects on cell function and, in the longer term, may induce apoptosis. Connective tissue cells such as fibroblasts, osteoblasts and chondrocytes synthesise and secrete large quantities of proteins and mutations in many of these gene products give rise to heritable disorders of connective tissues. Until recently, these mutant gene products were thought to exert their effect through the assembly of a defective extracellular matrix that ultimately disrupted tissue structure and function. However, it is now becoming clear that ER stress and UPR, because of the expression of a mutant gene product, is not only a feature of, but may be a key mediator in the initiation and progression of a whole range of different connective tissue diseases. This review focuses on ER stress and the UPR that characterises an increasing number of connective tissue diseases and highlights novel therapeutic opportunities that may arise.
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Maisa A, Ströher U, Klenk HD, Garten W, Strecker T. Inhibition of Lassa virus glycoprotein cleavage and multicycle replication by site 1 protease-adapted alpha(1)-antitrypsin variants. PLoS Negl Trop Dis 2009; 3:e446. [PMID: 19488405 PMCID: PMC2685025 DOI: 10.1371/journal.pntd.0000446] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2009] [Accepted: 04/28/2009] [Indexed: 12/02/2022] Open
Abstract
Background Proteolytic processing of the Lassa virus envelope glycoprotein precursor GP-C by the host proprotein convertase site 1 protease (S1P) is a prerequisite for the incorporation of the subunits GP-1 and GP-2 into viral particles and, hence, essential for infectivity and virus spread. Therefore, we tested in this study the concept of using S1P as a target to block efficient virus replication. Methodology/Principal Finding We demonstrate that stable cell lines inducibly expressing S1P-adapted α1-antitrypsin variants inhibit the proteolytic maturation of GP-C. Introduction of the S1P recognition motifs RRIL and RRLL into the reactive center loop of α1-antitrypsin resulted in abrogation of GP-C processing by endogenous S1P to a similar level observed in S1P-deficient cells. Moreover, S1P-specific α1-antitrypsins significantly inhibited replication and spread of a replication-competent recombinant vesicular stomatitis virus expressing the Lassa virus glycoprotein GP as well as authentic Lassa virus. Inhibition of viral replication correlated with the ability of the different α1-antitrypsin variants to inhibit the processing of the Lassa virus glycoprotein precursor. Conclusions/Significance Our data suggest that glycoprotein cleavage by S1P is a promising target for the development of novel anti-arenaviral strategies. The virus family Arenaviridae includes several hemorrhagic fever causing agents such as Lassa, Guanarito, Junin, Machupo, and Sabia virus that pose a major public health concern to the human population in West African and South American countries. Current treatment options to control fatal outcome of disease are limited to the ribonucleoside analogue ribavirin, although its use has some significant limitations. The lack of effective treatment alternatives emphasizes the need for novel antiviral therapeutics to counteract these life-threatening infections. Maturation cleavage of the viral envelope glycoprotein by the host cell proprotein convertase site 1 protease (S1P) is critical for infectious virion production of several pathogenic arenaviruses. This finding makes this protease an attractive target for the development of novel anti-arenaviral therapeutics. We demonstrate here that highly selective S1P-adapted α1-antitrypsins have the potential to efficiently inhibit glycoprotein processing, which resulted in reduced Lassa virus replication. Our findings suggest that S1P should be considered as an antiviral target and that further optimization of modified α1-antitrypsins could lead to potent and specific S1P inhibitors with the potential for treatment of certain viral hemorrhagic fevers.
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Affiliation(s)
- Anna Maisa
- Institut für Virologie, Philipps-Universität Marburg, Marburg, Germany
| | - Ute Ströher
- Molecular Virology & Antiviral Approaches Unit, Special Pathogens Program, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
- Department of Medical Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Hans-Dieter Klenk
- Institut für Virologie, Philipps-Universität Marburg, Marburg, Germany
| | - Wolfgang Garten
- Institut für Virologie, Philipps-Universität Marburg, Marburg, Germany
- * E-mail:
| | - Thomas Strecker
- Institut für Virologie, Philipps-Universität Marburg, Marburg, Germany
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Yang G, Sun Q, Teng Y, Li F, Weng T, Yang X. PTEN deficiency causes dyschondroplasia in mice by enhanced hypoxia-inducible factor 1α signaling and endoplasmic reticulum stress. Development 2008; 135:3587-97. [DOI: 10.1242/dev.028118] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Chondrocytes within the growth plates acclimatize themselves to a variety of stresses that might otherwise disturb cell fate. The tumor suppressor PTEN(phosphatase and tensin homolog deleted from chromosome 10) has been implicated in the maintenance of cell homeostasis. However, the functions of PTEN in regulating chondrocytic adaptation to stresses remain largely unknown. In this study, we have created chondrocyte-specific Pten knockout mice (Ptenco/co;Col2a1-Cre) using the Cre-loxP system. Following AKT activation, Pten mutant mice exhibited dyschondroplasia resembling human enchondroma. Cartilaginous nodules originated from Pten mutant resting chondrocytes that suffered from impaired proliferation and differentiation, and this was coupled with enhanced endoplasmic reticulum (ER) stress. We further found that ER stress in Pten mutant chondrocytes only occurred under hypoxic stress,characterized by an upregulation of unfolded protein response-related genes as well as an engorged and fragmented ER in which collagens were trapped. An upregulation of hypoxia-inducible factor 1α (HIF1α) and downstream targets followed by ER stress induction was also observed in Ptenmutant growth plates and in cultured chondrocytes, suggesting that PI3K/AKT signaling modulates chondrocytic adaptation to hypoxic stress via regulation of the HIF1α pathway. These data demonstrate that PTEN function in chondrocytes is essential for their adaptation to stresses and for the inhibition of dyschondroplasia.
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Affiliation(s)
- Guan Yang
- State Key Laboratory of Proteomics, Genetic Laboratory of Development and Diseases, Institute of Biotechnology, 20 Dongdajie, Beijing 100071,China
| | - Qiang Sun
- State Key Laboratory of Proteomics, Genetic Laboratory of Development and Diseases, Institute of Biotechnology, 20 Dongdajie, Beijing 100071,China
| | - Yan Teng
- State Key Laboratory of Proteomics, Genetic Laboratory of Development and Diseases, Institute of Biotechnology, 20 Dongdajie, Beijing 100071,China
| | - Fangfei Li
- State Key Laboratory of Proteomics, Genetic Laboratory of Development and Diseases, Institute of Biotechnology, 20 Dongdajie, Beijing 100071,China
| | - Tujun Weng
- State Key Laboratory of Proteomics, Genetic Laboratory of Development and Diseases, Institute of Biotechnology, 20 Dongdajie, Beijing 100071,China
| | - Xiao Yang
- State Key Laboratory of Proteomics, Genetic Laboratory of Development and Diseases, Institute of Biotechnology, 20 Dongdajie, Beijing 100071,China
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Patra D, Xing X, Davies S, Bryan J, Franz C, Hunziker EB, Sandell LJ. Site-1 protease is essential for endochondral bone formation in mice. J Exp Med 2007. [DOI: 10.1084/jem20412oia28] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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