1
|
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.
Collapse
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
| |
Collapse
|
2
|
Aktas SH, Taskin-Tok T, Al-Khafaji K, Akın-Balı DF. A detailed understanding of the COL10A1 and SOX9 genes interaction based on potentially damaging mutations in gastric cancer using computational techniques. J Biomol Struct Dyn 2022; 40:11533-11544. [PMID: 34380365 DOI: 10.1080/07391102.2021.1960194] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Gastric cancer (GC) has limited effective treatment options and is followed up with biomarkers that have insufficient sensitivity and specificity. Recent studies on Collagen Type X Alpha 1 Chain (COL10A1) show that the COL10A1 gene may be a diagnostic and/or prognostic biomarker for different cancer types. Moreover, its relationship with the Sex determining Region Y (SRY)-related High-Mobility Group (HMG) box (SOX9) gene which is also a transcription factor, was discovered recently, and co-expression of these two genes are associated with the development of GC. However, to the best of our knowledge, there is no study in the literature on how potential damaging mutations in the SOX9 and COL10A1 genes can affect their interactions. The aim of this study is to investigate the interactions of wild-type and potentially damaging mutated structures of COL10A1 and SOX9 genes. Thus, outputs for drug development and therapeutic strategies for GC can be obtained. For this purpose, structure validation and energy minimization analyses as well as docking and binding affinity calculations were performed. As a result, it was found that all investigated mutations (P563S, I588L, T624A, H165R and N110T) increased the binding affinity between the COL10A1-SOX9 complex, especially the N110T and H165R mutants in SOX9. As a conclusion, the N110T and H165R mutants in SOX9 may contribute to tumor progression. Therefore, it is important to consider these mutations for future therapeutic strategies.Communicated by Ramaswamy H. Sarma.
Collapse
Affiliation(s)
- Sedef Hande Aktas
- Vocational School of Health Services, Eskisehir Osmangazi University, Eskisehir, Turkey.,Department of Biotechnology and Biosafety, Graduate School of Natural and Applied Science, Eskisehir Osmangazi University, Eskisehir, Turkey
| | - Tugba Taskin-Tok
- Department of Chemistry, Faculty of Arts and Sciences, Gaziantep University, Gaziantep, Turkey.,Department of Bioinformatics and Computational Biology, Institute of Health Sciences, Gaziantep University, Gaziantep, Turkey
| | - Khattab Al-Khafaji
- Department of Chemistry, Faculty of Arts and Sciences, Gaziantep University, Gaziantep, Turkey
| | | |
Collapse
|
3
|
Liang Q, Lin X, Wu X, Shao Y, Chen C, Dai J, Lu Y, Wu W, Ding Q, Wang X. Unraveling the molecular basis underlying nine putative splice site variants of von Willebrand factor. Hum Mutat 2021; 43:215-227. [PMID: 34882887 DOI: 10.1002/humu.24312] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 11/17/2021] [Accepted: 12/06/2021] [Indexed: 12/15/2022]
Abstract
Approximately 10% of von Willebrand factor (VWF) gene variants are suspected to disrupt messenger RNA (mRNA) processing, the number of which might be underestimated due to the lack of transcript assays. In the present study, we provided a detailed strategy to evaluate the effects of nine putative splice site variants (PSSVs) of VWF on mRNA processing as well as protein properties and establish their genotype-phenotype relationships. Eight of nine PSSVs affected VWF splicing: c.322A>T, c.1534-13_1551delinsCA, and c.8116-2del caused exon skipping; c.221-2A>C, c.323+1G>T, and c.2547-13T>A resulted in the activation of cryptic splice sites; c.2684A>G led to exon skipping and activation of a cryptic splice site; c.2968-14A>G created a new splice site. The remaining c.5171-9del was likely benign. The efficiency of nonsense-mediated mRNA decay (NMD) was much higher in platelets compared to leukocytes, impairing the identification of aberrant transcripts in 4 of 8 PSSVs. The nonsense variant c.322A>T partially impaired mRNA processing, leaking a small amount of correct transcripts with c.322T (p.Arg108*), while the missense variant c.2684A>G totally disrupted normal splicing of VWF, rather than produced mutant protein with the substitution of Gln895Arg. The results of this study would certainly add novel insights into the molecular events behind von Willebrand disease.
Collapse
Affiliation(s)
- Qian Liang
- Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.,State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Xiaoyi Lin
- Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Xi Wu
- Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Yanyan Shao
- Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Changming Chen
- Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Jing Dai
- Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Yeling Lu
- Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Wenman Wu
- Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.,Collaborative Innovation Center of Hematology, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Qiulan Ding
- Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.,Collaborative Innovation Center of Hematology, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Xuefeng Wang
- Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.,Collaborative Innovation Center of Hematology, Shanghai Jiaotong University School of Medicine, Shanghai, China
| |
Collapse
|
4
|
Wu H, Wang S, Li G, Yao Y, Wang N, Sun X, Fang L, Jiang X, Zhao J, Wang Y, Xu C. Characterization of a novel COL10A1 variant associated with Schmid-type metaphyseal chondrodysplasia and a literature review. Mol Genet Genomic Med 2021; 9:e1668. [PMID: 33764685 PMCID: PMC8172203 DOI: 10.1002/mgg3.1668] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 07/22/2020] [Accepted: 02/19/2021] [Indexed: 12/05/2022] Open
Abstract
Background Schmid‐type metaphyseal chondrodysplasia (SMCD) is a rare autosomal dominant skeletal dysplasia caused by heterozygous mutations in COL10A1, the gene which encodes collagen type X alpha 1 chain. However, its genotype–phenotype relationship has not been fully determined. Subjects and Methods The proband is a 2‐year‐old boy, born of non‐consanguineous Chinese parents. We conducted a systematic analysis of the clinical and radiological characteristics and a follow‐up study of the proband. Whole‐exome sequencing was applied for the genetic analysis, together with bioinformatic analysis of predicted consequences of the identified variant. A homotrimer model was built to visualize the affected region and predict possible outcomes of this variant. Furthermore, a literature review and genotype–phenotype analysis were performed by online searching all cases with SMCD. Results A novel heterozygous variant (NM_000493.4: c.1863_1866delAATG, NP_000484.2: p.(Met622 Thrfs*54)) was identified in COL10A1 gene in the affected child. And it was predicted to be pathogenic by in silico analysis. Protein modeling revealed that the variant was located in the NC1 domain, which was predicted to produce truncated collagen and impair the trimerization of collagen type X alpha 1 chain and combination with molecules in the matrix. Moreover, genotype–phenotype correlation analysis demonstrated that patients with truncating variants or variants in NC1 domain often presented earlier onset and severer symptoms compared with those with non‐truncating or variants in non‐NC1 domains. Conclusion The NC1 domain of COL10A1 was proved to be the hotspot region underlying SMCD, patients with variants in NC1 domain were more likely to present severer manifestations at an earlier age.
Collapse
Affiliation(s)
- Huixiao Wu
- Department of Endocrinology and Metabolism, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China.,Department of Endocrinology and Metabolism, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China.,Institute of Endocrinology, Shandong Academy of Clinical Medicine, Jinan, China.,Shandong Clinical Medical Center of Endocrinology and Metabolism, Jinan, China
| | - Shuping Wang
- Department of Endocrinology and Metabolism, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China.,Department of Endocrinology and Metabolism, Dongying people's Hospital, Dongying, China
| | - Guimei Li
- Department of Pediatric, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Yangyang Yao
- Department of Pediatric Orthopedics, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Ning Wang
- Institute of Endocrinology, Shandong Academy of Clinical Medicine, Jinan, China.,Shandong Clinical Medical Center of Endocrinology and Metabolism, Jinan, China
| | - Xiaoqing Sun
- Institute of Endocrinology, Shandong Academy of Clinical Medicine, Jinan, China.,Shandong Clinical Medical Center of Endocrinology and Metabolism, Jinan, China
| | - Li Fang
- Department of Endocrinology and Metabolism, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China.,Department of Endocrinology and Metabolism, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China.,Institute of Endocrinology, Shandong Academy of Clinical Medicine, Jinan, China.,Shandong Clinical Medical Center of Endocrinology and Metabolism, Jinan, China
| | - Xiuyun Jiang
- Department of Endocrinology and Metabolism, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China.,Department of Endocrinology and Metabolism, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China.,Institute of Endocrinology, Shandong Academy of Clinical Medicine, Jinan, China.,Shandong Clinical Medical Center of Endocrinology and Metabolism, Jinan, China
| | - Jiajun Zhao
- Department of Endocrinology and Metabolism, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China.,Department of Endocrinology and Metabolism, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China.,Institute of Endocrinology, Shandong Academy of Clinical Medicine, Jinan, China.,Shandong Clinical Medical Center of Endocrinology and Metabolism, Jinan, China
| | - Yanzhou Wang
- Department of Pediatric Orthopedics, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Chao Xu
- Department of Endocrinology and Metabolism, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China.,Department of Endocrinology and Metabolism, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China.,Institute of Endocrinology, Shandong Academy of Clinical Medicine, Jinan, China.,Shandong Clinical Medical Center of Endocrinology and Metabolism, Jinan, China
| |
Collapse
|
5
|
Identification of two novel COL10A1 heterozygous mutations in two Chinese pedigrees with Schmid-type metaphyseal chondrodysplasia. BMC MEDICAL GENETICS 2019; 20:200. [PMID: 31856751 PMCID: PMC6923838 DOI: 10.1186/s12881-019-0937-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 12/12/2019] [Indexed: 01/11/2023]
Abstract
Background Schmid-type metaphyseal chondrodysplasia (MCDS) is an autosomal dominant disorder caused by COL10A1 mutations, which is characterized by short stature, waddling gait, coxa vara and bowing of the long bones. However, descriptions of the expressivity of MCDS are rare. Methods Two probands and available family members affected with MCDS were subjected to clinical and radiological examination. Genomic DNA of all affected individuals was subjected to whole-exome sequencing, and candidate mutations were verified by Sanger sequencing in all available family members and in 250 healthy donors. A spatial model of the type X collagen (α1) C-terminal noncollagenous (NC1) domain was further constructed. Results We found that the phenotype of affected family members exhibited incomplete dominance. Mutation analysis indicated that there were two novel heterozygous missense mutations, [c.1765 T > A (p.Phe589Ile)] and [c.1846A > G (p.Lys616Glu)] in the COL10A1 gene in family 1 and 2, respectively. The two novel substitution sites were highly conserved and the mutations were predicted to be deleterious by in silico analysis. Furthermore, protein modeling revealed that the two substitutions were located in the NC1 domain of collagen X (α1), which potentially impacted the trimerization of collagen X (α1) and combination with molecules in the pericellular matrix. Conclusion Two novel mutations were identified in the present study, which will facilitate diagnosis of MCDS and further expand the spectrum of the COL10A1 mutations associated with MCDS patients. In addition, our research revealed the phenomenon of incomplete dominance in MCDS.
Collapse
|
6
|
Forouhan M, Sonntag S, Boot-Handford RP. Carbamazepine reduces disease severity in a mouse model of metaphyseal chondrodysplasia type Schmid caused by a premature stop codon (Y632X) in the Col10a1 gene. Hum Mol Genet 2019; 27:3840-3853. [PMID: 30010889 PMCID: PMC6216233 DOI: 10.1093/hmg/ddy253] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 07/03/2018] [Indexed: 12/23/2022] Open
Abstract
Mutations, mostly in the region of the COL10A1 gene encoding the C-terminal non-collagenous domain, cause the dwarfism metaphyseal chondrodysplasia type Schmid (MCDS). In most cases, the disease mechanism involves the misfolding of the mutant protein causing increased endoplasmic reticulum (ER) stress and an unfolded protein response (UPR). However, in an iliac crest biopsy, the COL10A1 p.Y632X mutation was found to produce instability of the mutant mRNA such that little mutant protein may be produced. To investigate the disease mechanism further, a gene-targeted mouse model of the Col10a1 p.Y632X mutation was generated. In this model, the mutant mRNA showed no instability, and in mice heterozygous for the mutation, mutant and wild-type mRNAs were present at equal concentrations. The protein was translated from the mutant allele and retained within the cell, triggering increased ER stress and a UPR. The mutation produced a relatively severe form of MCDS. Nevertheless, treatment of the mice with carbamazepine (CBZ), a drug which stimulates intracellular proteolysis and alleviates ER stress, effectively reduced the disease severity in this model of MCDS caused by a premature stop codon in the Col10a1 gene. Specifically, the drug reduced ER stress in the growth plate, restored growth plate architecture toward the wild-type state, significantly increased bone growth and within 2 weeks of treatment corrected the MCDS-induced hip distortion. These results indicate that CBZ is likely to be effective in ongoing clinical trials against all forms of MCDS whether caused by premature stop codons or substitutions.
Collapse
Affiliation(s)
- Mitra Forouhan
- Wellcome Centre for Cell-Matrix Research, Faculty of Biology, Medicine and Health and Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
| | | | - Raymond P Boot-Handford
- Wellcome Centre for Cell-Matrix Research, Faculty of Biology, Medicine and Health and Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
| |
Collapse
|
7
|
Lejeune F. Nonsense-mediated mRNA decay at the crossroads of many cellular pathways. BMB Rep 2018; 50:175-185. [PMID: 28115040 PMCID: PMC5437961 DOI: 10.5483/bmbrep.2017.50.4.015] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Indexed: 12/22/2022] Open
Abstract
Nonsense-mediated mRNA decay (NMD) is a surveillance mechanism ensuring the fast decay of mRNAs harboring a premature termination codon (PTC). As a quality control mechanism, NMD distinguishes PTCs from normal termination codons in order to degrade PTC-carrying mRNAs only. For this, NMD is connected to various other cell processes which regulate or activate it under specific cell conditions or in response to mutations, mis-regulations, stresses, or particular cell programs. These cell processes and their connections with NMD are the focus of this review, which aims both to illustrate the complexity of the NMD mechanism and its regulation and to highlight the cellular consequences of NMD inhibition.
Collapse
Affiliation(s)
- Fabrice Lejeune
- University Lille, UMR8161 - M3T - Mechanisms of Tumorigenesis and Target Therapies; CNRS, UMR 8161, 3Institut Pasteur de Lille, F-59000 Lille, France
| |
Collapse
|
8
|
Park H, Hong S, Cho SI, Cho TJ, Choi IH, Jin DK, Sohn YB, Park SW, Cho HH, Cheon JE, Kim SY, Kim JY, Park SS, Seong MW. Case of mild Schmid-type metaphyseal chondrodysplasia with novel sequence variation involving an unusual mutational site of the COL10A1 gene. Eur J Med Genet 2015; 58:175-9. [DOI: 10.1016/j.ejmg.2014.12.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 12/04/2014] [Indexed: 10/24/2022]
|
9
|
Lu Y, Qiao L, Lei G, Mira RR, Gu J, Zheng Q. Col10a1 gene expression and chondrocyte hypertrophy during skeletal development and disease. ACTA ACUST UNITED AC 2014. [DOI: 10.1007/s11515-014-1310-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
10
|
Nonsense-mediated decay in genetic disease: friend or foe? MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2014; 762:52-64. [PMID: 25485595 DOI: 10.1016/j.mrrev.2014.05.001] [Citation(s) in RCA: 142] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Revised: 05/02/2014] [Accepted: 05/03/2014] [Indexed: 12/11/2022]
Abstract
Eukaryotic cells utilize various RNA quality control mechanisms to ensure high fidelity of gene expression, thus protecting against the accumulation of nonfunctional RNA and the subsequent production of abnormal peptides. Messenger RNAs (mRNAs) are largely responsible for protein production, and mRNA quality control is particularly important for protecting the cell against the downstream effects of genetic mutations. Nonsense-mediated decay (NMD) is an evolutionarily conserved mRNA quality control system in all eukaryotes that degrades transcripts containing premature termination codons (PTCs). By degrading these aberrant transcripts, NMD acts to prevent the production of truncated proteins that could otherwise harm the cell through various insults, such as dominant negative effects or the ER stress response. Although NMD functions to protect the cell against the deleterious effects of aberrant mRNA, there is a growing body of evidence that mutation-, codon-, gene-, cell-, and tissue-specific differences in NMD efficiency can alter the underlying pathology of genetic disease. In addition, the protective role that NMD plays in genetic disease can undermine current therapeutic strategies aimed at increasing the production of full-length functional protein from genes harboring nonsense mutations. Here, we review the normal function of this RNA surveillance pathway and how it is regulated, provide current evidence for the role that it plays in modulating genetic disease phenotypes, and how NMD can be used as a therapeutic target.
Collapse
|
11
|
Fang Y, Bateman JF, Mercer JF, Lamandé SR. Nonsense-mediated mRNA decay of collagen -emerging complexity in RNA surveillance mechanisms. J Cell Sci 2013; 126:2551-60. [PMID: 23729740 DOI: 10.1242/jcs.120220] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Nonsense-mediated mRNA decay (NMD) is an evolutionarily conserved mRNA surveillance system that degrades mRNA transcripts that harbour a premature translation-termination codon (PTC), thus reducing the synthesis of truncated proteins that would otherwise have deleterious effects. Although extensive research has identified a conserved repertoire of NMD factors, these studies have been performed with a restricted set of genes and gene constructs with relatively few exons. As a consequence, NMD mechanisms are poorly understood for genes with large 3' terminal exons, and the applicability of the current models to large multi-exon genes is not clear. In this Commentary, we present an overview of the current understanding of NMD and discuss how analysis of nonsense mutations in the collagen gene family has provided new mechanistic insights into this process. Although NMD of the collagen genes with numerous small exons is consistent with the widely accepted exon-junction complex (EJC)-dependent model, the degradation of Col10a1 transcripts with nonsense mutations cannot be explained by any of the current NMD models. Col10a1 NMD might represent a fail-safe mechanism for genes that have large 3' terminal exons. Defining the mechanistic complexity of NMD is important to allow us to understand the pathophysiology of the numerous genetic disorders caused by PTC mutations.
Collapse
Affiliation(s)
- Yiwen Fang
- Murdoch Childrens Research Institute, Royal Children's Hospital, Parkville 3052, Australia
| | | | | | | |
Collapse
|
12
|
Huang L, Wilkinson MF. Regulation of nonsense-mediated mRNA decay. WILEY INTERDISCIPLINARY REVIEWS-RNA 2012; 3:807-28. [PMID: 23027648 DOI: 10.1002/wrna.1137] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Nonsense-mediated mRNA decay (NMD) is a highly conserved pathway that was originally identified as a RNA surveillance mechanism that degrades aberrant mRNAs harboring premature termination (nonsense) codons. Recently, it was discovered that NMD also regulates normal gene expression. Genome-wide studies showed that ablation of NMD alters the expression of ∼10% of transcripts in a wide variety of eukaryotes. In general, NMD specifically targets normal transcripts that harbor a stop codon in a premature context. The finding that NMD regulates normal gene expression raises the possibility that NMD itself is subject to regulation. Indeed, recent studies have shown that NMD efficiency varies in different cell types and tissues. NMD is also subject to developmental control in both higher and lower eukaryotic species. Molecular mechanisms have been defined-including those involving microRNAs and other RNA decay pathways-that regulate the magnitude of NMD in some developmental settings. This developmental regulation of NMD appears to have physiological roles, at least in some model systems. In addition to mechanisms that modulate the efficiency of NMD, mechanisms have recently been identified that serve the opposite purpose: to maintain the efficiency of NMD in the face of insults. This 'buffering' is achieved by feedback networks that serve to regulate the stability of NMD factors. The discovery of NMD homeostasis and NMD regulatory mechanisms has important implications for how NMD acts in biological processes and how its magnitude could potentially be manipulated for clinical benefit.
Collapse
Affiliation(s)
- Lulu Huang
- Department of Reproductive Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | | |
Collapse
|
13
|
Cirillo G, Marini R, Ito S, Wakamatsu K, Scianguetta S, Bizzarri C, Romano A, Grandone A, Perrone L, Cappa M, Miraglia Del Giudice E. Lack of red hair phenotype in a North-African obese child homozygous for a novel POMC null mutation: nonsense-mediated decay RNA evaluation and hair pigment chemical analysis. Br J Dermatol 2012; 167:1393-5. [PMID: 22612534 DOI: 10.1111/j.1365-2133.2012.11060.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
14
|
Patronas Y, Horvath A, Greene E, Tsang K, Bimpaki E, Haran M, Nesterova M, Stratakis CA. In vitro studies of novel PRKAR1A mutants that extend the predicted RIα protein sequence into the 3'-untranslated open reading frame: proteasomal degradation leads to RIα haploinsufficiency and Carney complex. J Clin Endocrinol Metab 2012; 97:E496-502. [PMID: 22205709 PMCID: PMC3319211 DOI: 10.1210/jc.2011-2220] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Carney complex (CNC) is a multiple endocrine neoplasia syndrome due to inactivating mutations in the PRKAR1A gene that codes for type Iα regulatory (RIα) subunit of protein kinase A. Most PRKAR1A mutations are subject to nonsense mRNA decay (NMD) and, thus, lead to haploinsufficiency. METHODS AND SETTING Patient phenotyping for CNC features and DNA, RNA, protein, and transfection studies were carried out at a research center. RESULTS We describe in unrelated kindreds with CNC four naturally occurring PRKAR1A mutations (1055del4, 1067del4ins5, 1076delTTins13, and 1142del4) that are predicted to escape NMD because they are located in the last coding exon of the gene. The phenotype of CNC was not different from that in other patients with the condition, although the number of patients was small. Each of the mutations caused a frameshift that led to a new stop codon into the 3' untranslated open reading frame, predicting an elongated protein that, however, was absent in patient-derived cells. After site-directed mutagenesis, in vitro transcription, and cell-free translation experiments, the expected size mutant proteins were present. However, when the mutant constructs were transfected in adrenal (NCI-295), testicular (N-TERA), and embryonic (HEK293) cells and despite the presence of the mutant mRNA, Western blot analysis indicated that there were no longer proteins. The subsequent application of proteasome inhibitors to cells transfected with the mutant constructs led to the detection of the aberrant proteins, although a compound that affects protein folding had no effect. The wild-type protein was also decreased in both patient-derived cells and/or tissues as well as in the in vitro systems used in this study. CONCLUSIONS This was the first demonstration of proteasomal degradation of RIα protein variants leading to PRKAR1A haploinsufficiency and CNC, adding protein surveillance to NMD in the cellular mechanisms overseeing RIα synthesis. In agreement with the molecular data, CNC patients bearing PRKAR1A defects that extend the open reading frame did not have a different phenotype, although this has to be confirmed in a larger number of patients.
Collapse
Affiliation(s)
- Yianna Patronas
- Section on Endocrinology and Genetics, Program on Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Building 10, CRC, Room 1-3330, 10 Center Drive, MSC1103, Bethesda, Maryland 20892, USA
| | | | | | | | | | | | | | | |
Collapse
|
15
|
A novel mutation leading to elongation of the deduced α1(X) chain results in Metaphyseal Chondrodysplasia type Schmid. Clin Chim Acta 2011; 412:1266-9. [DOI: 10.1016/j.cca.2011.03.026] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Accepted: 03/21/2011] [Indexed: 12/24/2022]
|
16
|
Schmid-type metaphyseal chondrodysplasia as the result of a collagen type X defect due to a novel COL10A1 nonsense mutation: A case report of a novel COL10A1 mutation. J Orthop Sci 2011; 16:245-9. [PMID: 21360259 DOI: 10.1007/s00776-011-0021-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Accepted: 04/26/2010] [Indexed: 01/11/2023]
|
17
|
Lee SK, Lee KE, Jeong TS, Hwang YH, Kim S, Hu JCC, Simmer JP, Kim JW. FAM83H mutations cause ADHCAI and alter intracellular protein localization. J Dent Res 2010; 90:377-81. [PMID: 21118793 DOI: 10.1177/0022034510389177] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Mutations in a family with sequence similarity 83 member H (FAM83H) cause autosomal-dominant hypocalcification amelogenesis imperfecta (ADH CAI). All FAM83H ADHCAI-causing mutations terminate translation or shift the reading frame within the specific exon 5 segment that encodes from Ser(287) to Glu(694). Mutations near Glu(694) cause a milder, more localized phenotype. We identified disease-causing FAM83H mutations in two families with ADHCAI: family 1 (g.3115C>T, c.1993 C>T, p.Q665X) and family 2 (g.3151C>T, c.2029 C>T, p.Q677X). We also tested the hypothesis that truncation mutations alter the intracellular localization of FAM83H. Wild-type FAM83H and p.E694X mutant FAM83H fused to green fluorescent protein (GFP) localized in the cytoplasm of HEK293T cells, but the mutant FAM83H proteins (p.R325X, p.W460X, and p.Q677X) fused to GFP localized mainly in the nucleus with slight expression in the cytoplasm. We conclude that nuclear targeting of the truncated FAM83H protein contributes to the severe, generalized enamel phenotype.
Collapse
Affiliation(s)
- S-K Lee
- Department of Cell and Developmental Biology & Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Korea, 275-1 Yongon-dong, Chongno-gu, Seoul 110-768, Korea
| | | | | | | | | | | | | | | |
Collapse
|
18
|
Mäkitie O, Susic M, Cole WG. Early-onset metaphyseal chondrodysplasia type Schmid associated with a COL10A1 frame-shift mutation and impaired trimerization of wild-type α1(X) protein chains. J Orthop Res 2010; 28:1497-501. [PMID: 20872587 DOI: 10.1002/jor.21161] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Both dominant-negative and haploinsufficiency effects have been proposed in the pathogenesis of metaphyseal chondrodysplasia type Schmid (MCDS) due to nonsense and frame-shift mutations of COL10A1. This study examines these alternative effects. A proband with typical early-onset MCDS was ascertained and COL10A1 sequencing undertaken. The assembly of trimeric collagen X molecules was studied using in vitro coupled transcription and translation of wild-type and mutant α1(X) cDNAs. The proband was heterozygous for a unique COL10A1 mutation, c.1735_1739del5ins22. Mutant protein chains, with the corresponding p.G579fsX611 change, failed to spontaneously trimerize. When wild-type α1(X) chains were translated alone, 57 ± 7% of the chains assembled into stable collagen X trimers. Trimerization of wild-type chains was significantly reduced to 33 ± 6% when translated in 1:1 mixtures with p.G579fsX611 α1(X) chains. The protein assembly assay showed that the mutant chains exerted a dominant-negative effect on collagen X assembly. Previous studies indicate that nonsense-mediated decay, activation of endoplasmic reticulum, and unfolded protein responses as well as altered chondrocyte differentiation are the major determinants of phenotypic severity and age of presentation. We speculate that complete loss of mutant transcripts yields COL10A1 haploinsufficiency and late clinical presentation while incomplete loss of mutant transcripts yields dominant-negative effects with early clinical presentation.
Collapse
Affiliation(s)
- Outi Mäkitie
- Department of Pediatrics, Hospital for Children and Adolescents, University of Helsinki, Helsinki, Finland.
| | | | | |
Collapse
|
19
|
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.
Collapse
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
| | | | | | | |
Collapse
|
20
|
Hyun HK, Lee SK, Lee KE, Kang HY, Kim EJ, Choung PH, Kim JW. Identification of a novel FAM83H mutation and microhardness of an affected molar in autosomal dominant hypocalcified amelogenesis imperfecta. Int Endod J 2009; 42:1039-43. [PMID: 19825039 DOI: 10.1111/j.1365-2591.2009.01617.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIM To determine the underlying molecular genetic aetiology of a family with the hypocalcified form of amelogenesis imperfecta and to investigate the hardness of the enamel and dentine of a known FAM83H mutation. METHODOLOGY Mutational screening of the FAM83H on the basis of candidate gene approach was performed. All exons and exon-intron boundaries was amplified and sequenced. A microhardness test was performed to measure the Vickers microhardness value. RESULTS A novel nonsense mutation (c.1354C>T, p.Q452X) was identified in the last exon of FAM83H, which resulted in soft, uncalcified enamel. The affected enamel was extremely soft (about 17% of the normal control), but the underlying dentine was as hard as the normal control. CONCLUSIONS Mutational analysis revealed a novel mutation in FAM83H gene. Hardness of dentine was not affected by the mutation, whilst the enamel was extremely soft.
Collapse
Affiliation(s)
- H-K Hyun
- Department of Pediatric Dentistry, Dental Research Institute and BK21 Program, School of Dentistry, Seoul National University, Seoul, Korea
| | | | | | | | | | | | | |
Collapse
|
21
|
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.
Collapse
|
22
|
Wright JT, Frazier-Bowers S, Simmons D, Alexander K, Crawford P, Han ST, Hart PS, Hart TC. Phenotypic variation in FAM83H-associated amelogenesis imperfecta. J Dent Res 2009; 88:356-60. [PMID: 19407157 DOI: 10.1177/0022034509333822] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
FAM83H gene mutations are associated with autosomal-dominant hypocalcified amelogenesis imperfecta (ADHCAI), which is typically characterized by enamel having normal thickness and a markedly decreased mineral content. This study tested the hypothesis that there are phenotype and genotype associations in families with FAM83H-associated ADHCAI. Seven families segregating ADHCAI (147 individuals) were evaluated. Phenotyping included clinical, radiographic, histological, and biochemical studies, and genotyping was by mutational analysis. Multiple novel FAM83H mutations were identified, including two 2-bp-deletion mutations, the first non-nonsense mutations identified. Craniofacial deviation from normal was more prevalent in the affected individuals. Affected individuals having truncating FAMH3H mutations of 677 or fewer amino acids presented a generalized ADHCAI phenotype, while those having mutations capable of producing a protein of at least 694 amino acids had a unique and previously unreported phenotype affecting primarily the cervical enamel. This investigation shows that unique phenotypes are associated with specific FAM83H mutations.
Collapse
Affiliation(s)
- J T Wright
- Dept. of Pediatric Dentistry, School of Dentistry, CB #7450 Brauer Hall, UNC Chapel Hill, NC 27599, USA.
| | | | | | | | | | | | | | | |
Collapse
|
23
|
|
24
|
Genetic diseases of connective tissues: cellular and extracellular effects of ECM mutations. Nat Rev Genet 2009; 10:173-83. [PMID: 19204719 DOI: 10.1038/nrg2520] [Citation(s) in RCA: 232] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Tissue-specific extracellular matrices (ECMs) are crucial for normal development and tissue function, and mutations in ECM genes result in a wide range of serious inherited connective tissue disorders. Mutations cause ECM dysfunction by combinations of two mechanisms. First, secretion of the mutated ECM components can be reduced by mutations affecting synthesis or by structural mutations causing cellular retention and/or degradation. Second, secretion of mutant protein can disturb crucial ECM interactions, structure and stability. Moreover, recent experiments suggest that endoplasmic reticulum (ER) stress, caused by mutant misfolded ECM proteins, contributes to the molecular pathology. Targeting ER stress might offer a new therapeutic strategy.
Collapse
|
25
|
Hart PS, Becerik S, Cogulu D, Emingil G, Ozdemir-Ozenen D, Han ST, Sulima PP, Firatli E, Hart TC. Novel FAM83H mutations in Turkish families with autosomal dominant hypocalcified amelogenesis imperfecta. Clin Genet 2009; 75:401-4. [PMID: 19220331 DOI: 10.1111/j.1399-0004.2008.01112.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
26
|
Zetoune AB, Fontanière S, Magnin D, Anczuków O, Buisson M, Zhang CX, Mazoyer S. Comparison of nonsense-mediated mRNA decay efficiency in various murine tissues. BMC Genet 2008; 9:83. [PMID: 19061508 PMCID: PMC2607305 DOI: 10.1186/1471-2156-9-83] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2008] [Accepted: 12/05/2008] [Indexed: 11/26/2022] Open
Abstract
Background The Nonsense-Mediated mRNA Decay (NMD) pathway detects and degrades mRNAs containing premature termination codons, thereby preventing the accumulation of potentially detrimental truncated proteins. Intertissue variation in the efficiency of this mechanism has been suggested, which could have important implications for the understanding of genotype-phenotype correlations in various genetic disorders. However, compelling evidence in favour of this hypothesis is lacking. Here, we have explored this question by measuring the ratio of mutant versus wild-type Men1 transcripts in thirteen tissues from mice carrying a heterozygous truncating mutation in the ubiquitously expressed Men1 gene. Results Significant differences were found between two groups of tissues. The first group, which includes testis, ovary, brain and heart, displays a strong decrease of the nonsense transcript (average ratio of 18% of mutant versus wild-type Men1 transcripts, identical to the value measured in murine embryonic fibroblasts). The second group, comprising lung, intestine and thymus, shows much less pronounced NMD (average ratio of 35%). Importantly, the extent of degradation by NMD does not correlate with the expression level of eleven genes encoding proteins involved in NMD or with the expression level of the Men1 gene. Conclusion Mouse models are an attractive option to evaluate the efficiency of NMD in multiple mammalian tissues and organs, given that it is much easier to obtain these from a mouse than from a single individual carrying a germline truncating mutation. In this study, we have uncovered in the thirteen different murine tissues that we examined up to a two-fold difference in NMD efficiency.
Collapse
Affiliation(s)
- Almoutassem B Zetoune
- Laboratoire de Génétique Moléculaire, Signalisation et Cancer UMR5201 CNRS, Equipe Labellisée par Ligue Nationale contre Cance, Université Lyon 1, Université de Lyon, Faculté de Médecine, Lyon, France.
| | | | | | | | | | | | | |
Collapse
|