1
|
Oktem A, Kocyigit P, Tuncalı T, Kahraman U, Ozbolat S. X-linked Dyskeratosis Congenita Case with Mutation 1058C>T(p.Ala353Val) in Dyskerine Gene. Indian J Dermatol 2024; 69:106. [PMID: 38572035 PMCID: PMC10986892 DOI: 10.4103/ijd.ijd_556_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2024] Open
Abstract
Dyskeratosis congenita (DC) is a rare inherited bone marrow failure syndrome and telomere biology disorder, usullay consisting of a triad of oral leucoplakia, dystrophic nails, reticular skin pigmentation. The diagnosis in the majority of cases can be made following all the clinical findings of this triad are established. Here we report 7 years-old boy who had oral leukoplakia and nail abnormality without skin involvement, associated with bone marrow failure diagnosed with X-linked DC due to dyskerin (DKC1) mutation. Our report emphasizes the fact that clinical suspicion can prevent fatal consequences since all manifestations may not always be seen collectively.
Collapse
Affiliation(s)
- Ayse Oktem
- From the Department of Dermatology, Medical Genetics, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Pelin Kocyigit
- From the Department of Dermatology, Medical Genetics, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Timur Tuncalı
- From the Department of Dermatology, Medical Genetics, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Ulviyye Kahraman
- From the Department of Dermatology, Medical Genetics, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Sumeyra Ozbolat
- From the Department of Dermatology, Medical Genetics, Faculty of Medicine, Ankara University, Ankara, Turkey
| |
Collapse
|
2
|
Keszthelyi TM, Tory K. The importance of pseudouridylation: human disorders related to the fifth nucleoside. Biol Futur 2023:10.1007/s42977-023-00158-3. [PMID: 37000312 DOI: 10.1007/s42977-023-00158-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 03/09/2023] [Indexed: 04/01/2023]
Abstract
Pseudouridylation is one of the most abundant RNA modifications in eukaryotes, making pseudouridine known as the "fifth nucleoside." This highly conserved alteration affects all non-coding and coding RNA types. Its role and importance have been increasingly widely researched, especially considering that its absence or damage leads to serious hereditary diseases. Here, we summarize the human genetic disorders described to date that are related to the participants of the pseudouridylation process.
Collapse
Affiliation(s)
| | - Kálmán Tory
- Department of Pediatrics, Semmelweis University, Budapest, Hungary
| |
Collapse
|
3
|
Revy P, Kannengiesser C, Bertuch AA. Genetics of human telomere biology disorders. Nat Rev Genet 2023; 24:86-108. [PMID: 36151328 DOI: 10.1038/s41576-022-00527-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/11/2022] [Indexed: 01/24/2023]
Abstract
Telomeres are specialized nucleoprotein structures at the ends of linear chromosomes that prevent the activation of DNA damage response and repair pathways. Numerous factors localize at telomeres to regulate their length, structure and function, to avert replicative senescence or genome instability and cell death. In humans, Mendelian defects in several of these factors can result in abnormally short or dysfunctional telomeres, causing a group of rare heterogeneous premature-ageing diseases, termed telomeropathies, short-telomere syndromes or telomere biology disorders (TBDs). Here, we review the TBD-causing genes identified so far and describe their main functions associated with telomere biology. We present molecular aspects of TBDs, including genetic anticipation, phenocopy, incomplete penetrance and somatic genetic rescue, which underlie the complexity of these diseases. We also discuss the implications of phenotypic and genetic features of TBDs on fundamental aspects related to human telomere biology, ageing and cancer, as well as on diagnostic, therapeutic and clinical approaches.
Collapse
Affiliation(s)
- Patrick Revy
- INSERM UMR 1163, Laboratory of Genome Dynamics in the Immune System, Equipe Labellisée Ligue Nationale contre le Cancer, Paris, France.
- Université Paris Cité, Imagine Institute, Paris, France.
| | - Caroline Kannengiesser
- APHP Service de Génétique, Hôpital Bichat, Paris, France
- Inserm U1152, Université Paris Cité, Paris, France
| | - Alison A Bertuch
- Departments of Paediatrics and Molecular & Human Genetics, Baylor College of Medicine, Houston, TX, USA
| |
Collapse
|
4
|
Ding D, Gao R, Xue Q, Luan R, Yang J. Genomic Fingerprint Associated with Familial Idiopathic Pulmonary Fibrosis: A Review. Int J Med Sci 2023; 20:329-345. [PMID: 36860670 PMCID: PMC9969503 DOI: 10.7150/ijms.80358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 01/12/2023] [Indexed: 02/04/2023] Open
Abstract
Idiopathic pulmonary fibrosis (IPF) is a severe interstitial lung disease; although the recent introduction of two anti-fibrosis drugs, pirfenidone and Nidanib, have resulted in a significant reduction in lung function decline, IPF is still not curable. Approximately 2-20% of patients with IPF have a family history of the disease, which is considered the strongest risk factor for idiopathic interstitial pneumonia. However, the genetic predispositions of familial IPF (f-IPF), a particular type of IPF, remain largely unknown. Genetics affect the susceptibility and progression of f-IPF. Genomic markers are increasingly being recognized for their contribution to disease prognosis and drug therapy outcomes. Existing data suggest that genomics may help identify individuals at risk for f-IPF, accurately classify patients, elucidate key pathways involved in disease pathogenesis, and ultimately develop more effective targeted therapies. Since several genetic variants associated with the disease have been found in f-IPF, this review systematically summarizes the latest progress in the gene spectrum of the f-IPF population and the underlying mechanisms of f-IPF. The genetic susceptibility variation related to the disease phenotype is also illustrated. This review aims to improve the understanding of the IPF pathogenesis and facilitate his early detection.
Collapse
Affiliation(s)
- Dongyan Ding
- Department of Respiratory Medicine, The Second Hospital of Jilin University, Changchun, China
| | - Rong Gao
- Department of Respiratory Medicine, The Second Hospital of Jilin University, Changchun, China
| | - Qianfei Xue
- Hospital of Jilin University, Changchun, China
| | - Rumei Luan
- Department of Respiratory Medicine, The Second Hospital of Jilin University, Changchun, China
| | - Junling Yang
- Department of Respiratory Medicine, The Second Hospital of Jilin University, Changchun, China
| |
Collapse
|
5
|
Ramos H, Aly MM, Balasubramanian SK. Late Presentation of Dyskeratosis Congenita: Germline Predisposition to Adult-Onset Secondary Acute Myeloid Leukemia. Hematol Rep 2022; 14:294-299. [PMID: 36278519 PMCID: PMC9589946 DOI: 10.3390/hematolrep14040042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 08/12/2022] [Accepted: 09/19/2022] [Indexed: 11/12/2022] Open
Abstract
Classic dyskeratosis congenita is a hereditary disease where the majority of patients present with bone marrow failure and mucocutaneous changes: mainly skin pigmentation, nail dystrophy, oral premalignant leukoplakia, in addition to increased risk for malignancies. A 63-year-old man with a long history of untreated chronic pulmonary disease, a smoker in the past, presented initially with pancytopenia and a clinical diagnosis of myelodysplastic syndrome with excess blasts returned a month later with leukocytosis (WBC 215.9 × 106/μL) and diagnosed with acute myeloid leukemia (AML) with deletion of chromosome 7 and FLT3-TKD mutation. The patient's mother and sister died in their 6th decade from rapidly progressing fulminant pulmonary fibrosis. He had abnormal skin pigmentation and oral leukoplakia on presentation. He was induced with 7 + 3 chemotherapy and started on midostaurin but experienced prolonged cytopenias, complicated by hypoxic acute on chronic respiratory failure requiring intubation and mechanical ventilation. D + 28 and D + 36 bone marrow examination showed trilineage hypoplasia but no blasts, though the D + 28 bone marrow biopsy revealed one metaphase with del (7) that was cleared on D + 35. The constellation of clinical features and strong family history along with del 7 and FLT3-TKD AML with preceding MDS highly suggests a germline predisposition state dyskeratosis congenita. Germline predispositions are often underrecognized as delayed onset conditions leading to AML and may have treatment and preventative implications especially genetic counseling for blood-related family members.
Collapse
Affiliation(s)
- Harry Ramos
- School of Medicine, Wayne State University, Detroit, MI 48201, USA
| | - Mai Mostafa Aly
- Clinical Hematology Unit, Department of Internal Medicine, Assiut University, Assiut 71515, Egypt
| | - Suresh Kumar Balasubramanian
- Department of Oncology, School of Medicine, Wayne State University, Detroit, MI 48201, USA
- Correspondence: ; Tel.: +1-216-925-7323
| |
Collapse
|
6
|
Borziak K, Finkelstein J. X-linked genetic risk factors that promote autoimmunity and dampen remyelination are associated with multiple sclerosis susceptibility. Mult Scler Relat Disord 2022; 66:104065. [PMID: 35905688 DOI: 10.1016/j.msard.2022.104065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 04/14/2022] [Accepted: 07/17/2022] [Indexed: 01/21/2023]
Abstract
BACKGROUND Multiple sclerosis (MS) is a chronic neurodegenerative disease, which has a strong genetic component and is more prevalent in women. MS is caused by an autoimmunity initiated inflammatory response which leads to axon demyelination, followed by axon loss, plaque formation and neurodegeneration. The goal of this article was to explore X-linked genetic factors that are associated with MS susceptibility. METHODS Using UK Biobank microarray, we analyzed the prevalence of alleles on the X chromosome to identify variants potentially involved in MS. Overall, 488,225 patients across 18,857 markers were analyzed using PLINK. RESULTS Our results identify 20 SNPs that are significantly more abundant in persons with MS. The genes associated with these SNPs belong to immunity (LAMP2, AVPR2, MTMR8, F8, BCOR, PORCN, and ELF4) and remyelination (NSDHL, HS6ST2, RBM10, TAZ, and AR) pathways that are potentially of great significance for understanding the onset and progression of multiple sclerosis. We further identified a significant 20-fold increase in incidence of MS cases in women with co-occurrences of SNPs associated with myelination and immunity functions. CONCLUSIONS Our analysis provides novel insights into the roles of X-linked genes in the onset and presentation of multiple sclerosis, identifying 20 SNPs in 14 genes involved primarily in immunity and myelination functions that are significantly more abundant in persons with MS. Our co-occurrence analysis suggests that concurrent disruption of both myelination and immune systems significantly increases the risk of MS onset in women.
Collapse
Affiliation(s)
- Kirill Borziak
- Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029 United States.
| | - Joseph Finkelstein
- Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029 United States
| |
Collapse
|
7
|
Abstract
Telomere biology was first studied in maize, ciliates, yeast, and mice, and in recent decades, it has informed understanding of common disease mechanisms with broad implications for patient care. Short telomere syndromes are the most prevalent premature aging disorders, with prominent phenotypes affecting the lung and hematopoietic system. Less understood are a newly recognized group of cancer-prone syndromes that are associated with mutations that lengthen telomeres. A large body of new data from Mendelian genetics and epidemiology now provides an opportunity to reconsider paradigms related to the role of telomeres in human aging and cancer, and in some cases, the findings diverge from what was interpreted from model systems. For example, short telomeres have been considered potent drivers of genome instability, but age-associated solid tumors are rare in individuals with short telomere syndromes, and T cell immunodeficiency explains their spectrum. More commonly, short telomeres promote clonal hematopoiesis, including somatic reversion, providing a new leukemogenesis paradigm that is independent of genome instability. Long telomeres, on the other hand, which extend the cellular life span in vitro, are now appreciated to be the most common shared germline risk factor for cancer in population studies. Through this contemporary lens, I revisit here the role of telomeres in human aging, focusing on how short and long telomeres drive cancer evolution but through distinct mechanisms.
Collapse
Affiliation(s)
- Mary Armanios
- Departments of Oncology, Genetic Medicine, Pathology, and Molecular Biology and Genetics; Telomere Center at Johns Hopkins; and Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA;
| |
Collapse
|
8
|
Abstract
Parenchymal lung disease is the fourth leading cause of death in the United States; among the top causes, it continues on the rise. Telomeres and telomerase have historically been linked to cellular processes related to aging and cancer, but surprisingly, in the recent decade genetic discoveries have linked the most apparent manifestations of telomere and telomerase dysfunction in humans to the etiology of lung disease: both idiopathic pulmonary fibrosis (IPF) and emphysema. The short telomere defect is pervasive in a subset of IPF patients, and human IPF is the phenotype most intimately tied to germline defects in telomere maintenance. One-third of families with pulmonary fibrosis carry germline mutations in telomerase or other telomere maintenance genes, and one-half of patients with apparently sporadic IPF have short telomere length. Beyond explaining genetic susceptibility, short telomere length uncovers clinically relevant syndromic extrapulmonary disease, including a T-cell immunodeficiency and a propensity to myeloid malignancies. Recognition of this subset of patients who share a unifying molecular defect has provided a precision medicine paradigm wherein the telomere-mediated lung disease diagnosis provides more prognostic value than histopathology or multidisciplinary evaluation. Here, we critically evaluate this progress, emphasizing how the genetic findings put forth a new pathogenesis paradigm of age-related lung disease that links telomere abnormalities to alveolar stem senescence, remodeling, and defective gas exchange.
Collapse
Affiliation(s)
- Jonathan K. Alder
- Division of Pulmonary and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh PA, United States
| | - Mary Armanios
- Departments of Oncology and Genetic Medicine, Telomere Center at Johns Hopkins, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| |
Collapse
|
9
|
Baptista B, Riscado M, Queiroz J, Pichon C, Sousa F. Non-coding RNAs: Emerging from the discovery to therapeutic applications. Biochem Pharmacol 2021. [DOI: 10.1016/j.bcp.2021.114469 order by 22025--] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/30/2022]
|
10
|
Baptista B, Riscado M, Queiroz JA, Pichon C, Sousa F. Non-coding RNAs: Emerging from the discovery to therapeutic applications. Biochem Pharmacol 2021; 189:114469. [PMID: 33577888 DOI: 10.1016/j.bcp.2021.114469] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 02/03/2021] [Accepted: 02/04/2021] [Indexed: 02/06/2023]
Abstract
The knowledge about non-coding RNAs (ncRNAs) is rapidly increasing with new data continuously emerging, regarding their diverse types, applications, and roles. Particular attention has been given to ncRNA with regulatory functions, which may have a critical role both in biological and pathological conditions. As a result of the diversity of ncRNAs and their ubiquitous involvement in several biologic processes, ncRNA started to be considered in the biomedical field, with immense potential to be exploited either as biomarkers or as therapeutic agents in certain pathologies. Indeed, ncRNA-based therapeutics have been proposed in many disorders and some even reached clinical trials. However, to prepare an RNA product suitable for pharmacological applications, certain criteria must be fulfilled, and it has to be guaranteed RNA purity, stability, and bioactivity. So, in this review, the different types of ncRNAs are identified and characterized, by describing their biogenesis, functions, and applications. A perspective on the main challenges and innovative approaches for the future and broad therapeutic application of RNA is also presented.
Collapse
Affiliation(s)
- B Baptista
- CICS-UBI - Health Sciences Research Centre, University of Beira Interior, Avenida Infante D. Henrique, 6200-506 Covilhã, Portugal
| | - M Riscado
- CICS-UBI - Health Sciences Research Centre, University of Beira Interior, Avenida Infante D. Henrique, 6200-506 Covilhã, Portugal
| | - J A Queiroz
- CICS-UBI - Health Sciences Research Centre, University of Beira Interior, Avenida Infante D. Henrique, 6200-506 Covilhã, Portugal
| | - C Pichon
- Centre de Biophysique Moléculaire (CBM), UPR 4301 CNRS & University of Orléans Orléans, France
| | - F Sousa
- CICS-UBI - Health Sciences Research Centre, University of Beira Interior, Avenida Infante D. Henrique, 6200-506 Covilhã, Portugal.
| |
Collapse
|
11
|
Carrascoso-Rubio C, Zittersteijn HA, Pintado-Berninches L, Fernández-Varas B, Lozano ML, Manguan-Garcia C, Sastre L, Bueren JA, Perona R, Guenechea G. Generation of dyskeratosis congenita-like hematopoietic stem cells through the stable inhibition of DKC1. Stem Cell Res Ther 2021; 12:92. [PMID: 33514435 PMCID: PMC7844988 DOI: 10.1186/s13287-021-02145-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 01/06/2021] [Indexed: 11/23/2022] Open
Abstract
Dyskeratosis congenita (DC) is a rare telomere biology disorder, which results in different clinical manifestations, including severe bone marrow failure. To date, the only curative treatment for the bone marrow failure in DC patients is allogeneic hematopoietic stem cell transplantation. However, due to the toxicity associated to this treatment, improved therapies are recommended for DC patients. Here, we aimed at generating DC-like human hematopoietic stem cells in which the efficacy of innovative therapies could be investigated. Because X-linked DC is the most frequent form of the disease and is associated with an impaired expression of DKC1, we have generated DC-like hematopoietic stem cells based on the stable knock-down of DKC1 in human CD34+ cells with lentiviral vectors encoding for DKC1 short hairpin RNAs. At a molecular level, DKC1-interfered CD34+ cells showed a decreased expression of TERC, as well as a diminished telomerase activity and increased DNA damage, cell senescence, and apoptosis. Moreover, DKC1-interfered human CD34+ cells showed defective clonogenic ability and were incapable of repopulating the hematopoiesis of immunodeficient NSG mice. The development of DC-like hematopoietic stem cells will facilitate the understanding of the molecular and cellular basis of this inherited bone marrow failure syndrome and will serve as a platform to evaluate the efficacy of new hematopoietic therapies for DC.
Collapse
Affiliation(s)
- Carlos Carrascoso-Rubio
- Instituto de Investigaciones Biomédicas Alberto Sols (CSIC/UAM), 28029, Madrid, Spain.,Division of Hematopoietic Innovative Therapies, Centro de Investigaciones Energéticas Medioambientales y Tecnológicas (CIEMAT), Avenida Complutense, 40, 28040, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 28029, Madrid, Spain.,Advanced Therapies Unit, Instituto de Investigación Sanitaria Fundación Jiménez Díaz (IIS-FJD/UAM), 28040, Madrid, Spain
| | - Hidde A Zittersteijn
- Division of Hematopoietic Innovative Therapies, Centro de Investigaciones Energéticas Medioambientales y Tecnológicas (CIEMAT), Avenida Complutense, 40, 28040, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 28029, Madrid, Spain.,Advanced Therapies Unit, Instituto de Investigación Sanitaria Fundación Jiménez Díaz (IIS-FJD/UAM), 28040, Madrid, Spain
| | - Laura Pintado-Berninches
- Instituto de Investigaciones Biomédicas Alberto Sols (CSIC/UAM), 28029, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 28029, Madrid, Spain
| | - Beatriz Fernández-Varas
- Instituto de Investigaciones Biomédicas Alberto Sols (CSIC/UAM), 28029, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 28029, Madrid, Spain
| | - M Luz Lozano
- Division of Hematopoietic Innovative Therapies, Centro de Investigaciones Energéticas Medioambientales y Tecnológicas (CIEMAT), Avenida Complutense, 40, 28040, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 28029, Madrid, Spain.,Advanced Therapies Unit, Instituto de Investigación Sanitaria Fundación Jiménez Díaz (IIS-FJD/UAM), 28040, Madrid, Spain
| | - Cristina Manguan-Garcia
- Instituto de Investigaciones Biomédicas Alberto Sols (CSIC/UAM), 28029, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 28029, Madrid, Spain
| | - Leandro Sastre
- Instituto de Investigaciones Biomédicas Alberto Sols (CSIC/UAM), 28029, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 28029, Madrid, Spain
| | - Juan A Bueren
- Division of Hematopoietic Innovative Therapies, Centro de Investigaciones Energéticas Medioambientales y Tecnológicas (CIEMAT), Avenida Complutense, 40, 28040, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 28029, Madrid, Spain.,Advanced Therapies Unit, Instituto de Investigación Sanitaria Fundación Jiménez Díaz (IIS-FJD/UAM), 28040, Madrid, Spain
| | - Rosario Perona
- Instituto de Investigaciones Biomédicas Alberto Sols (CSIC/UAM), 28029, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 28029, Madrid, Spain
| | - Guillermo Guenechea
- Division of Hematopoietic Innovative Therapies, Centro de Investigaciones Energéticas Medioambientales y Tecnológicas (CIEMAT), Avenida Complutense, 40, 28040, Madrid, Spain. .,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 28029, Madrid, Spain. .,Advanced Therapies Unit, Instituto de Investigación Sanitaria Fundación Jiménez Díaz (IIS-FJD/UAM), 28040, Madrid, Spain.
| |
Collapse
|
12
|
Alnafakh R, Saretzki G, Midgley A, Flynn J, Kamal AM, Dobson L, Natarajan P, Stringfellow H, Martin-Hirsch P, DeCruze SB, Coupland SE, Hapangama DK. Aberrant Dyskerin Expression Is Related to Proliferation and Poor Survival in Endometrial Cancer. Cancers (Basel) 2021; 13:cancers13020273. [PMID: 33450922 PMCID: PMC7828388 DOI: 10.3390/cancers13020273] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 01/06/2021] [Accepted: 01/08/2021] [Indexed: 12/13/2022] Open
Abstract
Simple Summary Telomeres are the protective caps at the ends of chromosomes, and they are maintained by an enzyme called telomerase. Telomerase activity allows rapid reproduction of the cells (proliferation) of the lining of the womb (endometrium). Telomerase levels are high in cancers in general, including in endometrial cancer. Dyskerin is one of the main components of the telomerase enzyme. While the other main components of telomerase have been studied in endometrial cancer, there are no previous studies on dyskerin in the endometrium. Our study shows that dyskerin levels are significantly lower in endometrial cancer and levels are linked to the survival of women. Experimentally increasing dyskerin protein in endometrial cells in the laboratory reduces the rate of cell proliferation. Consequently, we propose that dyskerin may be a regulator of endometrial cancer cell proliferation, and further studies are required to test if it can be targeted to develop new therapies for endometrial cancer. Abstract Dyskerin is a core-component of the telomerase holo-enzyme, which elongates telomeres. Telomerase is involved in endometrial epithelial cell proliferation. Most endometrial cancers (ECs) have high telomerase activity; however, dyskerin expression in human healthy endometrium or in endometrial pathologies has not been investigated yet. We aimed to examine the expression, prognostic relevance, and functional role of dyskerin in human EC. Endometrial samples from a cohort of 175 women were examined with immunohistochemistry, immunoblotting, and qPCR. The EC cells were transfected with Myc-DDK-DKC1 plasmid and the effect of dyskerin overexpression on EC cell proliferation was assessed by flow cytometry. Human endometrium expresses dyskerin (DKC1) and dyskerin protein levels are significantly reduced in ECs when compared with healthy postmenopausal endometrium. Low dyskerin immunoscores were potentially associated with worse outcomes, suggesting a possible prognostic relevance. Cancer Genome Atlas (TCGA) ECs dataset (n = 589) was also interrogated. The TCGA dataset further confirmed changes in DKC1 expression in EC with prognostic significance. Transient dyskerin overexpression had a negative effect on EC cell proliferation. Our data demonstrates a role for dyskerin in normal endometrium for the first time and confirms aberrant expression with possible prognostic relevance in EC. Interventions aimed at modulating dyskerin levels may provide novel therapeutic options in EC.
Collapse
Affiliation(s)
- Rafah Alnafakh
- Liverpool Women’s Hospital NHS Foundation Trust, Member of Liverpool Health Partners, Liverpool L8 7SS, UK; (R.A.); (L.D.); (P.N.); (S.B.D.)
- Department of Women’s and Children’s Health, Institute of Life Course and Medical Sciences, University of Liverpool, Member of Liverpool Health Partners, Liverpool L8 7SS, UK;
- Department of Pathology, Al-Hilla Teaching Hospital, Babil, Iraq
| | - Gabriele Saretzki
- Biosciences Institute, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne NE4 5PL, UK;
| | - Angela Midgley
- Experimental Arthritis Treatment Centre for Children, Institute in the Park, Department of Women’s and Children’s Health, University of Liverpool, Liverpool L12 2AP, UK;
| | | | - Areege M. Kamal
- Department of Women’s and Children’s Health, Institute of Life Course and Medical Sciences, University of Liverpool, Member of Liverpool Health Partners, Liverpool L8 7SS, UK;
- Pathology Department, Oncology Teaching Hospital, Baghdad Medical City, Baghdad, Iraq
| | - Lucy Dobson
- Liverpool Women’s Hospital NHS Foundation Trust, Member of Liverpool Health Partners, Liverpool L8 7SS, UK; (R.A.); (L.D.); (P.N.); (S.B.D.)
- Department of Women’s and Children’s Health, Institute of Life Course and Medical Sciences, University of Liverpool, Member of Liverpool Health Partners, Liverpool L8 7SS, UK;
| | - Purushothaman Natarajan
- Liverpool Women’s Hospital NHS Foundation Trust, Member of Liverpool Health Partners, Liverpool L8 7SS, UK; (R.A.); (L.D.); (P.N.); (S.B.D.)
- Department of Women’s and Children’s Health, Institute of Life Course and Medical Sciences, University of Liverpool, Member of Liverpool Health Partners, Liverpool L8 7SS, UK;
| | - Helen Stringfellow
- Lancashire Teaching Hospital NHS Trust, Preston PR2 9HT, UK; (H.S.); (P.M.-H.)
| | | | - Shandya B. DeCruze
- Liverpool Women’s Hospital NHS Foundation Trust, Member of Liverpool Health Partners, Liverpool L8 7SS, UK; (R.A.); (L.D.); (P.N.); (S.B.D.)
| | - Sarah E. Coupland
- Molecular and Clinical Cancer Medicine, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L7 8TX, UK;
| | - Dharani K. Hapangama
- Liverpool Women’s Hospital NHS Foundation Trust, Member of Liverpool Health Partners, Liverpool L8 7SS, UK; (R.A.); (L.D.); (P.N.); (S.B.D.)
- Department of Women’s and Children’s Health, Institute of Life Course and Medical Sciences, University of Liverpool, Member of Liverpool Health Partners, Liverpool L8 7SS, UK;
- Correspondence:
| |
Collapse
|
13
|
Israfil A, Israfil N. RETRACTED: Temperament gene inheritance. Meta Gene 2020. [DOI: 10.1016/j.mgene.2020.100728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
|
14
|
Gaysinskaya V, Stanley SE, Adam S, Armanios M. Synonymous Mutation in DKC1 Causes Telomerase RNA Insufficiency Manifesting as Familial Pulmonary Fibrosis. Chest 2020; 158:2449-2457. [PMID: 32710892 DOI: 10.1016/j.chest.2020.07.025] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 07/11/2020] [Accepted: 07/13/2020] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Idiopathic pulmonary fibrosis (IPF) is the most common of short telomere phenotypes. Familial clustering of IPF is common, but the genetic basis remains unknown in more than one-half of cases. We identified a 65-year-old man with familial IPF, short telomere length, and low telomerase RNA levels. He was diagnosed with a short telomere syndrome after developing hematologic complications post-lung transplantation, but no mutations were identified in a clinical testing pipeline. RESEARCH QUESTION What is the molecular basis underlying the familial IPF and low telomerase RNA levels in this patient? STUDY DESIGN AND METHODS We analyzed whole-genome sequence data and performed functional molecular studies on cells derived from the patient and his family. RESULTS We identified a previously unreported synonymous variant c.942G>A p.K314K in DKC1, the gene encoding the dyskerin ribonucleoprotein, which is required for telomerase RNA biogenesis. The mutation created a competing de novo exonic splicing enhancer, and the misspliced product was degraded by nonsense-mediated decay causing an overall dyskerin deficiency in mutation carriers. In silico tools identified other rare silent DKC1 variants that warrant functional evaluation if found in patients with short telomere-mediated disease. INTERPRETATION Our data point to silent mutation in telomere maintenance genes as a mechanism of familial pulmonary fibrosis. In contrast to DKC1 missense mutations, which primarily manifest in children as dyskeratosis congenita, hypomorphic mutations affecting dyskerin levels likely have a predilection to presenting in adults as pulmonary fibrosis.
Collapse
Affiliation(s)
- Valeriya Gaysinskaya
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD; Telomere Center, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Susan E Stanley
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD; Telomere Center, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Soheir Adam
- Department of Medicine, Duke University School of Medicine, Durham, NC
| | - Mary Armanios
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD; Sidney Kimmel Comprehensive Cancer, Johns Hopkins University School of Medicine, Baltimore, MD.
| |
Collapse
|
15
|
MacNeil DE, Lambert-Lanteigne P, Autexier C. N-terminal residues of human dyskerin are required for interactions with telomerase RNA that prevent RNA degradation. Nucleic Acids Res 2019; 47:5368-5380. [PMID: 30931479 PMCID: PMC6547437 DOI: 10.1093/nar/gkz233] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 03/19/2019] [Accepted: 03/25/2019] [Indexed: 12/16/2022] Open
Abstract
The telomerase holoenzyme responsible for maintaining telomeres in vertebrates requires many components in vivo, including dyskerin. Dyskerin binds and regulates the accumulation of the human telomerase RNA, hTR, as well as other non-coding RNAs that share the conserved H/ACA box motif. The precise mechanism by which dyskerin controls hTR levels is unknown, but is evidenced by defective hTR accumulation caused by substitutions in dyskerin, that are observed in the X-linked telomere biology disorder dyskeratosis congenita (X-DC). To understand the role of dyskerin in hTR accumulation, we analyzed X-DC substitutions K39E and K43E in the poorly characterized dyskerin N-terminus, and A353V within the canonical RNA binding domain (the PUA). These variants exhibited impaired binding to hTR and polyadenylated hTR species, while interactions with other H/ACA RNAs appear largely unperturbed by the N-terminal substitutions. hTR accumulation and telomerase activity defects of dyskerin-deficient cells were rescued by wildtype dyskerin but not the variants. hTR 3′ extended or polyadenylated species did not accumulate, suggesting hTR precursor degradation occurs upstream of mature complex assembly in the absence of dyskerin binding. Our findings demonstrate that the dyskerin-hTR interaction mediated by PUA and N-terminal residues of dyskerin is crucial to prevent unchecked hTR degradation.
Collapse
Affiliation(s)
- Deanna E MacNeil
- Jewish General Hospital of McGill University, Lady Davis Institute, Montreal, Quebec H3T 1E2, Canada.,Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada
| | - Patrick Lambert-Lanteigne
- Jewish General Hospital of McGill University, Lady Davis Institute, Montreal, Quebec H3T 1E2, Canada
| | - Chantal Autexier
- Jewish General Hospital of McGill University, Lady Davis Institute, Montreal, Quebec H3T 1E2, Canada.,Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada
| |
Collapse
|
16
|
Integrating Genomics Into Management of Fibrotic Interstitial Lung Disease. Chest 2019; 155:1026-1040. [PMID: 30660786 DOI: 10.1016/j.chest.2018.12.011] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 11/30/2018] [Accepted: 12/20/2018] [Indexed: 12/31/2022] Open
Abstract
Fibrotic interstitial lung diseases (ILDs) have a high mortality rate with an unpredictable disease course and clinical features that frequently overlap. Recent data indicate important roles for genomics in the mechanisms underlying susceptibility and progression of pulmonary fibrosis. The impact of these genomic markers on pharmacotherapy and their contribution to outcomes is increasingly recognized. Interstitial lung abnormalities, frequently considered representative of early ILD, have been consistently associated with the MUC5B promoter polymorphism, a common gene variant. Other rare gene variant mutations, including TERT, TERC, SFTPC, and DKC1, may be present in patients with familial interstitial pneumonia and are frequently associated with a usual interstitial pneumonia pattern of fibrosis. The minor allele of the MUC5B rs35705950 genotype is prevalent in several sporadic forms of ILD, including idiopathic pulmonary fibrosis and chronic hypersensitivity pneumonitis. Gene mutations that characterize familial pulmonary fibrosis may be present in patients with connective tissue disease-related ILD, such as rheumatoid arthritis-ILD. Additionally, shorter telomere lengths and mutations in telomere biology-related genes have been demonstrated in both familial and sporadic ILD, with significant implications for disease progression, lung function, and survival. An improved understanding of the impact of genetic and genomic risk factors on disease progression would better guide personalized therapeutic choices in persons with fibrotic ILD.
Collapse
|
17
|
Guide snoRNAs: Drivers or Passengers in Human Disease? BIOLOGY 2018; 8:biology8010001. [PMID: 30577491 PMCID: PMC6466398 DOI: 10.3390/biology8010001] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 12/16/2018] [Accepted: 12/18/2018] [Indexed: 01/17/2023]
Abstract
In every domain of life, RNA-protein interactions play a significant role in co- and post-transcriptional modifications and mRNA translation. RNA performs diverse roles inside the cell, and therefore any aberrancy in their function can cause various diseases. During maturation from its primary transcript, RNA undergoes several functionally important post-transcriptional modifications including pseudouridylation and ribose 2′-O-methylation. These modifications play a critical role in the stability of the RNA. In the last few decades, small nucleolar RNAs (snoRNAs) were revealed to be one of the main components to guide these modifications. Due to their active links to the nucleoside modification, deregulation in the snoRNA expressions can cause multiple disorders in humans. Additionally, host genes carrying snoRNA-encoding sequences in their introns also show differential expression in disease. Although few reports support a causal link between snoRNA expression and disease manifestation, this emerging field will have an impact on the way we think about biomarkers or identify novel targets for therapy. This review focuses on the intriguing aspect of snoRNAs that function as a guide in post-transcriptional RNA modification, and regulation of their host genes in human disease.
Collapse
|
18
|
Wagner CL, Hanumanthu VS, Talbot CC, Abraham RS, Hamm D, Gable DL, Kanakry CG, Applegate CD, Siliciano J, Jackson JB, Desiderio S, Alder JK, Luznik L, Armanios M. Short telomere syndromes cause a primary T cell immunodeficiency. J Clin Invest 2018; 128:5222-5234. [PMID: 30179220 DOI: 10.1172/jci120216] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 08/28/2018] [Indexed: 12/13/2022] Open
Abstract
The mechanisms that drive T cell aging are not understood. We report that children and adult telomerase mutation carriers with short telomere length (TL) develop a T cell immunodeficiency that can manifest in the absence of bone marrow failure and causes life-threatening opportunistic infections. Mutation carriers shared T cell-aging phenotypes seen in adults 5 decades older, including depleted naive T cells, increased apoptosis, and restricted T cell repertoire. T cell receptor excision circles (TRECs) were also undetectable or low, suggesting that newborn screening may identify individuals with germline telomere maintenance defects. Telomerase-null mice with short TL showed defects throughout T cell development, including increased apoptosis of stimulated thymocytes, their intrathymic precursors, in addition to depleted hematopoietic reserves. When we examined the transcriptional programs of T cells from telomerase mutation carriers, we found they diverged from older adults with normal TL. Short telomere T cells upregulated DNA damage and intrinsic apoptosis pathways, while older adult T cells upregulated extrinsic apoptosis pathways and programmed cell death 1 (PD-1) expression. T cells from mice with short TL also showed an active DNA-damage response, in contrast with old WT mice, despite their shared propensity to apoptosis. Our data suggest there are TL-dependent and TL-independent mechanisms that differentially contribute to distinct molecular programs of T cell apoptosis with aging.
Collapse
Affiliation(s)
| | | | - C Conover Talbot
- Institute for Basic Biomedical Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Roshini S Abraham
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - David Hamm
- Adaptive Biotechnologies, Seattle, Washington, USA
| | | | | | | | | | | | - Stephen Desiderio
- Institute for Basic Biomedical Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Sidney Kimmel Comprehensive Cancer Center, and.,Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | | | - Leo Luznik
- Department of Oncology and.,Sidney Kimmel Comprehensive Cancer Center, and
| | - Mary Armanios
- Department of Oncology and.,McKusick-Nathans Institute of Genetic Medicine.,Department of Pathology.,Sidney Kimmel Comprehensive Cancer Center, and.,Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| |
Collapse
|
19
|
Merck SJ, Armanios M. Shall we call them "telomere-mediated"? Renaming the idiopathic after the cause is found. Eur Respir J 2018; 48:1556-1558. [PMID: 27903687 DOI: 10.1183/13993003.02115-2016] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 10/28/2016] [Indexed: 01/10/2023]
Affiliation(s)
- Samantha J Merck
- Dept of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Mary Armanios
- Dept of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, USA .,McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| |
Collapse
|
20
|
Abstract
Telomere length (TL) predicts the onset of cellular senescence in vitro but the diagnostic utility of TL measurement in clinical settings is not fully known. We tested the value of TL measurement by flow cytometry and FISH (flowFISH) in patients with mutations in telomerase and telomere maintenance genes. TL had a discrete and reproducible normal range with definable upper and lower boundaries. While TL above the 50th age-adjusted percentile had a 100% negative predictive value for clinically relevant mutations, the lower threshold in mutation carriers was age-dependent, and adult mutation carriers often overlapped with the lowest decile of controls. The extent of telomere shortening correlated with the age at diagnosis as well as the short telomere syndrome phenotype. Extremely short TL caused bone marrow failure and immunodeficiency in children and young adults, while milder defects manifested as pulmonary fibrosis-emphysema in adults. We prospectively examined whether TL altered treatment decisions for newly diagnosed idiopathic bone marrow failure patients and found abnormally short TL enriched for patients with mutations in some inherited bone marrow failure genes, such as RUNX1, in addition to telomerase and telomere maintenance genes. The result was actionable, altering the choice of treatment regimen and/or hematopoietic stem cell donor in one-fourth of the cases (9 of 38, 24%). We conclude that TL measurement by flowFISH, when used for targeted clinical indications and in limited settings, can influence treatment decisions in ways that improve outcome.
Collapse
|
21
|
Stanley SE, Gable DL, Wagner CL, Carlile TM, Hanumanthu VS, Podlevsky JD, Khalil SE, DeZern AE, Rojas-Duran MF, Applegate CD, Alder JK, Parry EM, Gilbert WV, Armanios M. Loss-of-function mutations in the RNA biogenesis factor NAF1 predispose to pulmonary fibrosis-emphysema. Sci Transl Med 2017; 8:351ra107. [PMID: 27510903 DOI: 10.1126/scitranslmed.aaf7837] [Citation(s) in RCA: 147] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2016] [Accepted: 07/14/2016] [Indexed: 12/23/2022]
Abstract
Chronic obstructive pulmonary disease and pulmonary fibrosis have been hypothesized to represent premature aging phenotypes. At times, they cluster in families, but the genetic basis is not understood. We identified rare, frameshift mutations in the gene for nuclear assembly factor 1, NAF1, a box H/ACA RNA biogenesis factor, in pulmonary fibrosis-emphysema patients. The mutations segregated with short telomere length, low telomerase RNA levels, and extrapulmonary manifestations including myelodysplastic syndrome and liver disease. A truncated NAF1 was detected in cells derived from patients, and, in cells in which the frameshift mutation was introduced by genome editing, telomerase RNA levels were reduced. The mutant NAF1 lacked a conserved carboxyl-terminal motif, which we show is required for nuclear localization. To understand the disease mechanism, we used CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 (CRISPR-associated protein-9 nuclease) to generate Naf1(+/-) mice and found that they had half the levels of telomerase RNA. Other box H/ACA RNA levels were also decreased, but rRNA pseudouridylation, which is guided by snoRNAs, was intact. Moreover, first-generation Naf1(+/-) mice showed no evidence of ribosomal pathology. Our data indicate that disease in NAF1 mutation carriers is telomere-mediated; they show that NAF1 haploinsufficiency selectively disturbs telomere length homeostasis by decreasing the levels of telomerase RNA while sparing rRNA pseudouridylation.
Collapse
Affiliation(s)
- Susan E Stanley
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA. Medical Scientist Training Program, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Dustin L Gable
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA. Medical Scientist Training Program, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Christa L Wagner
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Thomas M Carlile
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Vidya Sagar Hanumanthu
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Joshua D Podlevsky
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85277, USA
| | - Sara E Khalil
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Amy E DeZern
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA. Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA. Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Maria F Rojas-Duran
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Carolyn D Applegate
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA. Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA. McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Jonathan K Alder
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Erin M Parry
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA. Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Wendy V Gilbert
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Mary Armanios
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA. Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA. McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
| |
Collapse
|
22
|
Lee M, Roos P, Sharma N, Atalar M, Evans TA, Pellicore MJ, Davis E, Lam ATN, Stanley SE, Khalil SE, Solomon GM, Walker D, Raraigh KS, Vecchio-Pagan B, Armanios M, Cutting GR. Systematic Computational Identification of Variants That Activate Exonic and Intronic Cryptic Splice Sites. Am J Hum Genet 2017; 100:751-765. [PMID: 28475858 DOI: 10.1016/j.ajhg.2017.04.001] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 03/30/2017] [Indexed: 12/30/2022] Open
Abstract
We developed a variant-annotation method that combines sequence-based machine-learning classification with a context-dependent algorithm for selecting splice variants. Our approach is distinctive in that it compares the splice potential of a sequence bearing a variant with the splice potential of the reference sequence. After training, classification accurately identified 168 of 180 (93.3%) canonical splice sites of five genes. The combined method, CryptSplice, identified and correctly predicted the effect of 18 of 21 (86%) known splice-altering variants in CFTR, a well-studied gene whose loss-of-function variants cause cystic fibrosis (CF). Among 1,423 unannotated CFTR disease-associated variants, the method identified 32 potential exonic cryptic splice variants, two of which were experimentally evaluated and confirmed. After complete CFTR sequencing, the method found three cryptic intronic splice variants (one known and two experimentally verified) that completed the molecular diagnosis of CF in 6 of 14 individuals. CryptSplice interrogation of sequence data from six individuals with X-linked dyskeratosis congenita caused by an unknown disease-causing variant in DKC1 identified two splice-altering variants that were experimentally verified. To assess the extent to which disease-associated variants might activate cryptic splicing, we selected 458 pathogenic variants and 348 variants of uncertain significance (VUSs) classified as high confidence from ClinVar. Splice-site activation was predicted for 129 (28%) of the pathogenic variants and 75 (22%) of the VUSs. Our findings suggest that cryptic splice-site activation is more common than previously thought and should be routinely considered for all variants within the transcribed regions of genes.
Collapse
Affiliation(s)
- Melissa Lee
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | | | - Neeraj Sharma
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Melis Atalar
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Taylor A Evans
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Matthew J Pellicore
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Emily Davis
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Anh-Thu N Lam
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Susan E Stanley
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Sara E Khalil
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - George M Solomon
- Division of Pulmonary, Allergy, and Critical Care Medicine, University of Alabama at Birmingham, Birmingham, AL 35233 USA
| | - Doug Walker
- Pediatric Pulmonary Medicine, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Karen S Raraigh
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Briana Vecchio-Pagan
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Mary Armanios
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Garry R Cutting
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| |
Collapse
|
23
|
Walter JE, Armanios M, Shah U, Friedmann AM, Spitzer T, Sharatz SM, Hagen C. CASE RECORDS of the MASSACHUSETTS GENERAL HOSPITAL. Case 41-2015. A 14-Year-Old Boy with Immune and Liver Abnormalities. N Engl J Med 2015; 373:2664-76. [PMID: 26716919 DOI: 10.1056/nejmcpc1408595] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
24
|
Alder JK, Stanley SE, Wagner CL, Hamilton M, Hanumanthu VS, Armanios M. Exome sequencing identifies mutant TINF2 in a family with pulmonary fibrosis. Chest 2015; 147:1361-1368. [PMID: 25539146 DOI: 10.1378/chest.14-1947] [Citation(s) in RCA: 124] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Short telomeres are a common defect in idiopathic pulmonary fibrosis, yet mutations in the telomerase genes account for only a subset of these cases. METHODS We identified a family with pulmonary fibrosis, idiopathic infertility, and short telomeres. RESULTS Exome sequencing of blood-derived DNA revealed two mutations in the telomere-binding protein TINF2. The first was a 15-base-pair deletion encompassing the exon 6 splice acceptor site, and the second was a missense mutation, Thr284Arg. Haplotype analysis indicated both variants fell on the same allele. However, lung-derived DNA showed predominantly the Thr284Arg allele, indicating that the deletion seen in the blood was acquired and may have a protective advantage because it diminished expression of the missense mutation. This mosaicism may represent functional reversion in telomere syndromes similar to that described for Fanconi anemia. No mutations were identified in over 40 uncharacterized pulmonary fibrosis probands suggesting that mutant TINF2 accounts for a small subset of familial cases. However, similar to affected individuals in this family, we identified a history of male and female infertility preceding the onset of pulmonary fibrosis in 11% of TERT and TR mutation carriers (five of 45). CONCLUSIONS Our findings identify TINF2 as a mutant telomere gene in familial pulmonary fibrosis and suggest that infertility may precede the presentation of pulmonary fibrosis in a small subset of adults with telomere syndromes.
Collapse
Affiliation(s)
- Jonathan K Alder
- Department of Oncology and Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD; Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT
| | - Susan E Stanley
- Department of Oncology and Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD; McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Christa L Wagner
- Department of Oncology and Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD; McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Makenzie Hamilton
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT
| | - Vidya Sagar Hanumanthu
- Department of Oncology and Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD; McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Mary Armanios
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD.
| |
Collapse
|
25
|
Glousker G, Touzot F, Revy P, Tzfati Y, Savage SA. Unraveling the pathogenesis of Hoyeraal-Hreidarsson syndrome, a complex telomere biology disorder. Br J Haematol 2015; 170:457-71. [PMID: 25940403 DOI: 10.1111/bjh.13442] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Hoyeraal-Hreidarsson (HH) syndrome is a multisystem genetic disorder characterized by very short telomeres and considered a clinically severe variant of dyskeratosis congenita. The main cause of mortality, usually in early childhood, is bone marrow failure. Mutations in several telomere biology genes have been reported to cause HH in about 60% of the HH patients, but the genetic defects in the rest of the patients are still unknown. Understanding the aetiology of HH and its diverse manifestations is challenging because of the complexity of telomere biology and the multiple telomeric and non-telomeric functions played by telomere-associated proteins in processes such as telomere replication, telomere protection, DNA damage response and ribosome and spliceosome assembly. Here we review the known clinical complications, molecular defects and germline mutations associated with HH, and elucidate possible mechanistic explanations and remaining questions in our understanding of the disease.
Collapse
Affiliation(s)
- Galina Glousker
- Department of Genetics, The Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Fabien Touzot
- INSERM UMR 1163, Laboratory of Genome Dynamics in the Immune System, Paris Descartes - Sorbonne Paris Cité University, Imagine Institute, Paris, France
| | - Patrick Revy
- INSERM UMR 1163, Laboratory of Genome Dynamics in the Immune System, Paris Descartes - Sorbonne Paris Cité University, Imagine Institute, Paris, France
| | - Yehuda Tzfati
- Department of Genetics, The Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Sharon A Savage
- Clinical Genetics Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA
| |
Collapse
|
26
|
Stuart BD, Choi J, Zaidi S, Xing C, Holohan B, Chen R, Choi M, Dharwadkar P, Torres F, Girod CE, Weissler J, Fitzgerald J, Kershaw C, Klesney-Tait J, Mageto Y, Shay JW, Ji W, Bilguvar K, Mane S, Lifton RP, Garcia CK. Exome sequencing links mutations in PARN and RTEL1 with familial pulmonary fibrosis and telomere shortening. Nat Genet 2015; 47:512-7. [PMID: 25848748 PMCID: PMC4414891 DOI: 10.1038/ng.3278] [Citation(s) in RCA: 329] [Impact Index Per Article: 36.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 03/17/2015] [Indexed: 12/16/2022]
Abstract
Idiopathic pulmonary fibrosis (IPF) is an age-related disease featuring progressive lung scarring. To elucidate the molecular basis of IPF, we performed exome sequencing of familial kindreds with pulmonary fibrosis. Gene burden analysis comparing 78 European cases and 2,816 controls implicated PARN, an exoribonuclease with no previous connection to telomere biology or disease, with five new heterozygous damaging mutations in unrelated cases and none in controls (P = 1.3 × 10(-8)); mutations were shared by all affected relatives (odds in favor of linkage = 4,096:1). RTEL1, an established locus for dyskeratosis congenita, harbored significantly more new damaging and missense variants at conserved residues in cases than in controls (P = 1.6 × 10(-6)). PARN and RTEL1 mutation carriers had shortened leukocyte telomere lengths, and we observed epigenetic inheritance of short telomeres in family members. Together, these genes explain ~7% of familial pulmonary fibrosis and strengthen the link between lung fibrosis and telomere dysfunction.
Collapse
Affiliation(s)
- Bridget D. Stuart
- Eugene McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Jungmin Choi
- Department of Genetics, Yale School of Medicine, New Haven, Connecticut, USA
- Howard Hughes Medical Institute, Yale School of Medicine, New Haven, Connecticut, USA
| | - Samir Zaidi
- Department of Genetics, Yale School of Medicine, New Haven, Connecticut, USA
- Howard Hughes Medical Institute, Yale School of Medicine, New Haven, Connecticut, USA
| | - Chao Xing
- Eugene McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Brody Holohan
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Rui Chen
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Mihwa Choi
- Eugene McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Pooja Dharwadkar
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Fernando Torres
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Carlos E. Girod
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Jonathan Weissler
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - John Fitzgerald
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Corey Kershaw
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Julia Klesney-Tait
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Yolanda Mageto
- Department of Internal Medicine, University of Vermont College of Medicine, Burlington, Vermont, USA
| | - Jerry W. Shay
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Weizhen Ji
- Department of Genetics, Yale School of Medicine, New Haven, Connecticut, USA
- Howard Hughes Medical Institute, Yale School of Medicine, New Haven, Connecticut, USA
| | - Kaya Bilguvar
- Department of Genetics, Yale School of Medicine, New Haven, Connecticut, USA
- Yale Center for Genome Analysis, Yale School of Medicine, New Haven, Connecticut, USA
| | - Shrikant Mane
- Department of Genetics, Yale School of Medicine, New Haven, Connecticut, USA
- Yale Center for Genome Analysis, Yale School of Medicine, New Haven, Connecticut, USA
| | - Richard P. Lifton
- Department of Genetics, Yale School of Medicine, New Haven, Connecticut, USA
- Howard Hughes Medical Institute, Yale School of Medicine, New Haven, Connecticut, USA
- Yale Center for Genome Analysis, Yale School of Medicine, New Haven, Connecticut, USA
- Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | - Christine Kim Garcia
- Eugene McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| |
Collapse
|
27
|
Penzo M, Rocchi L, Brugiere S, Carnicelli D, Onofrillo C, Couté Y, Brigotti M, Montanaro L. Human ribosomes from cells with reduced dyskerin levels are intrinsically altered in translation. FASEB J 2015; 29:3472-82. [PMID: 25934701 DOI: 10.1096/fj.15-270991] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 04/21/2015] [Indexed: 12/19/2022]
Abstract
Dyskerin is a pseudouridine (ψ) synthase involved in fundamental cellular processes including uridine modification in rRNA and small nuclear RNA and telomere stabilization. Dyskerin functions are altered in X-linked dyskeratosis congenita (X-DC) and cancer. Dyskerin's role in rRNA pseudouridylation has been suggested to underlie the alterations in mRNA translation described in cells lacking dyskerin function, although relevant direct evidences are currently lacking. Our purpose was to establish definitely whether defective dyskerin function might determine an intrinsic ribosomal defect leading to an altered synthetic activity. Therefore, ribosomes from dyskerin-depleted human cells were purified and 1) added to a controlled reticulocyte cell-free system devoid of ribosomes to study mRNA translation; 2) analyzed for protein contamination and composition by mass spectrometry, 3) analyzed for global pseudouridylation levels. Ribosomes purified from dyskerin-depleted cells showed altered translational fidelity and internal ribosome entry site (IRES)-mediated translation. These ribosomes displayed reduced uridine modification, whereas they were not different in terms of protein contamination or ribosomal protein composition with respect to ribosomes from matched control cells with full dyskerin activity. In conclusion, lack of dyskerin function in human cells induces a defect in rRNA uridine modification, which is sufficient to alter ribosome activity.
Collapse
Affiliation(s)
- Marianna Penzo
- *Department of Experimental, Diagnostic, and Specialty Medicine, Alma Mater Studiorum-Università di Bologna, Bologna, Italy; University Grenoble Alpes, Commissariat à l'Énergie Atomique, Institut Régional de Travail Social, and Institut National de la Santé et de la Recherche Médicale, Biologie à Grande Echelle, Grenoble, France
| | - Laura Rocchi
- *Department of Experimental, Diagnostic, and Specialty Medicine, Alma Mater Studiorum-Università di Bologna, Bologna, Italy; University Grenoble Alpes, Commissariat à l'Énergie Atomique, Institut Régional de Travail Social, and Institut National de la Santé et de la Recherche Médicale, Biologie à Grande Echelle, Grenoble, France
| | - Sabine Brugiere
- *Department of Experimental, Diagnostic, and Specialty Medicine, Alma Mater Studiorum-Università di Bologna, Bologna, Italy; University Grenoble Alpes, Commissariat à l'Énergie Atomique, Institut Régional de Travail Social, and Institut National de la Santé et de la Recherche Médicale, Biologie à Grande Echelle, Grenoble, France
| | - Domenica Carnicelli
- *Department of Experimental, Diagnostic, and Specialty Medicine, Alma Mater Studiorum-Università di Bologna, Bologna, Italy; University Grenoble Alpes, Commissariat à l'Énergie Atomique, Institut Régional de Travail Social, and Institut National de la Santé et de la Recherche Médicale, Biologie à Grande Echelle, Grenoble, France
| | - Carmine Onofrillo
- *Department of Experimental, Diagnostic, and Specialty Medicine, Alma Mater Studiorum-Università di Bologna, Bologna, Italy; University Grenoble Alpes, Commissariat à l'Énergie Atomique, Institut Régional de Travail Social, and Institut National de la Santé et de la Recherche Médicale, Biologie à Grande Echelle, Grenoble, France
| | - Yohann Couté
- *Department of Experimental, Diagnostic, and Specialty Medicine, Alma Mater Studiorum-Università di Bologna, Bologna, Italy; University Grenoble Alpes, Commissariat à l'Énergie Atomique, Institut Régional de Travail Social, and Institut National de la Santé et de la Recherche Médicale, Biologie à Grande Echelle, Grenoble, France
| | - Maurizio Brigotti
- *Department of Experimental, Diagnostic, and Specialty Medicine, Alma Mater Studiorum-Università di Bologna, Bologna, Italy; University Grenoble Alpes, Commissariat à l'Énergie Atomique, Institut Régional de Travail Social, and Institut National de la Santé et de la Recherche Médicale, Biologie à Grande Echelle, Grenoble, France
| | - Lorenzo Montanaro
- *Department of Experimental, Diagnostic, and Specialty Medicine, Alma Mater Studiorum-Università di Bologna, Bologna, Italy; University Grenoble Alpes, Commissariat à l'Énergie Atomique, Institut Régional de Travail Social, and Institut National de la Santé et de la Recherche Médicale, Biologie à Grande Echelle, Grenoble, France
| |
Collapse
|
28
|
Loss of Drosophila pseudouridine synthase triggers apoptosis-induced proliferation and promotes cell-nonautonomous EMT. Cell Death Dis 2015; 6:e1705. [PMID: 25811802 PMCID: PMC4385944 DOI: 10.1038/cddis.2015.68] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 02/11/2015] [Accepted: 02/12/2015] [Indexed: 01/12/2023]
Abstract
Many developing tissues display regenerative capability that allows them to compensate cell loss and preserve tissue homeostasis. Because of their remarkable regenerative capability, Drosophila wing discs are extensively used for the study of regenerative phenomena. We thus used the developing wing to investigate the role played in tissue homeostasis by the evolutionarily conserved eukaryotic H/ACA small nucleolar ribonucleoprotein pseudouridine synthase. Here we show that localized depletion of this enzyme can act as an endogenous stimulus capable of triggering apoptosis-induced proliferation, and that context-dependent effects are elicited in different sub-populations of the silenced cells. In fact, some cells undergo apoptosis, whereas those surrounding the apoptotic foci, although identically depleted, overproliferate. This overproliferation correlates with ectopic induction of the Wg and JAK-STAT (Janus kinase-signal transducer and activator of transcription) mitogenic pathways. Expression of a p35 transgene, which blocks the complete execution of the death program and generates the so-called ‘undead cells', amplifies the proliferative response. Pseudouridine synthase depletion also causes loss of apicobasal polarity, disruption of adherens cell junctions and ectopic induction of JNK (c-Jun N-terminal kinase) and Mmp1 (matrix metalloproteinase-1) activity, leading to a significant epithelial reorganization. Unexpectedly, cell-nonautonomous effects, such as epithelial mesenchymal transition in the contiguous unsilenced squamous epithelium, are also promoted. Collectively, these data point out that cell–cell communication and long-range signaling can take a relevant role in the response to pseudouridine synthase decline. Considering that all the affected pathways are highly conserved throughout evolution, it is plausible that the response to pseudouridine synthase depletion has been widely preserved. On this account, our results can add new light on the still unexplained tumor predisposition that characterizes X-linked dyskeratosis, the human disease caused by reduced pseudouridine synthase activity.
Collapse
|
29
|
Angrisani A, Vicidomini R, Turano M, Furia M. Human dyskerin: beyond telomeres. Biol Chem 2014; 395:593-610. [PMID: 24468621 DOI: 10.1515/hsz-2013-0287] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Accepted: 01/24/2014] [Indexed: 12/15/2022]
Abstract
Human dyskerin is an evolutively conserved protein that participates in diverse nuclear complexes: the H/ACA snoRNPs, that control ribosome biogenesis, RNA pseudouridylation, and stability of H/ACA snoRNAs; the scaRNPs, that control pseudouridylation of snRNAs; and the telomerase active holoenzyme, which safeguards telomere integrity. The biological importance of dyskerin is further outlined by the fact that its deficiency causes the X-linked dyskeratosis congenita disease, while its over-expression characterizes several types of cancers and has been proposed as prognostic marker. The role of dyskerin in telomere maintenance has widely been discussed, while its functions as H/ACA sno/scaRNP component has been so far mostly overlooked and represent the main goal of this review. Here we summarize how increasing evidence indicates that the snoRNA/microRNA pathways can be interlaced, and that dyskerin-dependent RNA pseudouridylation represents a flexible mechanism able to modulate RNA function in different ways, including modulation of splicing, change of mRNA coding properties, and selective regulation of IRES-dependent translation. We also propose a speculative model that suggests that the dynamics of pre-assembly and nuclear import of H/ACA RNPs are crucial regulatory steps that can be finely controlled in the cytoplasm in response to developmental, differentiative and stress stimuli.
Collapse
|
30
|
Kropski JA, Mitchell DB, Markin C, Polosukhin VV, Choi L, Johnson JE, Lawson WE, Phillips JA, Cogan JD, Blackwell TS, Loyd JE. A novel dyskerin (DKC1) mutation is associated with familial interstitial pneumonia. Chest 2014; 146:e1-e7. [PMID: 24504062 DOI: 10.1378/chest.13-2224] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Short telomeres are frequently identified in patients with idiopathic pulmonary fibrosis (IPF) and its inherited form, familial interstitial pneumonia (FIP). We identified a kindred with FIP with short telomeres who did not carry a mutation in known FIP genes TERT or hTR . We performed targeted sequencing of other telomere-related genes to identify the genetic basis of FIP in this kindred. The proband was a 69 year-old man with dyspnea, restrictive pulmonary function test results, and reticular changes on high-resolution CT scan. An older male sibling had died from IPF. The proband had markedly shortened telomeres in peripheral blood and undetectably short telomeres in alveolar epithelial cells. Polymerase chain reaction-based sequencing of NOP10 , TINF2 , NHP2 , and DKC1 revealed that both affected siblings shared a novel A to G 1213 transition in DKC1 near the hTR binding domain that is predicted to encode a Thr405Ala amino acid substitution. hTR levels were decreased out of proportion to DKC1 expression in the T405A DKC1 proband, suggesting this mutation destabilizes hTR and impairs telomerase function. This DKC1 variant represents the third telomere-related gene identified as a genetic cause of FIP. Further investigation into the mechanism by which dyskerin contributes to the development of lung fibrosis is warranted.
Collapse
Affiliation(s)
- Jonathan A Kropski
- Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University School of Medicine, Vanderbilt University School of Medicine, Nashville, TN.
| | - Daphne B Mitchell
- Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University School of Medicine, Vanderbilt University School of Medicine, Nashville, TN
| | - Cheryl Markin
- Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University School of Medicine, Vanderbilt University School of Medicine, Nashville, TN
| | - Vasiliy V Polosukhin
- Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University School of Medicine, Vanderbilt University School of Medicine, Nashville, TN
| | - Leena Choi
- Department of Biostatistics, Vanderbilt University School of Medicine, Nashville, TN
| | - Joyce E Johnson
- Department of Pediatrics, Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN
| | - William E Lawson
- Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University School of Medicine, Vanderbilt University School of Medicine, Nashville, TN; Department of Veterans Affairs Medical Center, Vanderbilt University School of Medicine, Nashville, TN
| | - John A Phillips
- Division of Medical Genetics and Genomic Medicine, Vanderbilt University School of Medicine, Nashville, TN; Department of Pediatrics, Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN
| | - Joy D Cogan
- Division of Medical Genetics and Genomic Medicine, Vanderbilt University School of Medicine, Nashville, TN
| | - Timothy S Blackwell
- Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University School of Medicine, Vanderbilt University School of Medicine, Nashville, TN; Department of Veterans Affairs Medical Center, Vanderbilt University School of Medicine, Nashville, TN; Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, TN; Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN
| | - James E Loyd
- Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University School of Medicine, Vanderbilt University School of Medicine, Nashville, TN
| |
Collapse
|
31
|
Fernández García MS, Teruya-Feldstein J. The diagnosis and treatment of dyskeratosis congenita: a review. J Blood Med 2014; 5:157-67. [PMID: 25170286 PMCID: PMC4145822 DOI: 10.2147/jbm.s47437] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Dyskeratosis congenita (DC) is an inherited bone marrow failure (BMF) syndrome characterized by the classic triad of abnormal skin pigmentation, nail dystrophy, and oral leukoplakia. However, patients usually develop BMF and are predisposed to cancer, with increased risk for squamous cell carcinoma and hematolymphoid neoplasms. DC is a disease of defective telomere maintenance and is heterogeneous at the genetic level. It can be inherited in X-linked, autosomal dominant, or autosomal recessive patterns. Mutations in at least ten telomere- and telomerase-associated genes have been described in DC. There are no targeted therapies for DC and patients usually die of BMF due to a deficient renewing capability of hematopoietic stem cells. Allogeneic hematopoietic stem cell transplantation is the only curative treatment for BMF.
Collapse
Affiliation(s)
- M Soledad Fernández García
- Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA ; Department of Pathology, Hospital Universitario Central de Asturias, Oviedo, Spain
| | | |
Collapse
|
32
|
Carrillo J, González A, Manguán-García C, Pintado-Berninches L, Perona R. p53 pathway activation by telomere attrition in X-DC primary fibroblasts occurs in the absence of ribosome biogenesis failure and as a consequence of DNA damage. Clin Transl Oncol 2013; 16:529-38. [PMID: 24065372 DOI: 10.1007/s12094-013-1112-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 09/10/2013] [Indexed: 01/04/2023]
Abstract
BACKGROUND Dyskeratosis congenita (DC) is a rare inherited bone marrow failure syndrome with high clinical heterogeneity. Various mutations have been reported in DC patients, affecting genes that code for components of H/ACA ribonucleoproteins, proteins of the telomerase complex and components of the shelterin complex. OBJECTIVES We aim to clarify the role of ribosome biogenesis failure in senescence induction in X-DC since some studies in animal models have reported a decrease in ribosome biogenesis as a major role in the disease. METHODS Dyskerin was depleted in normal human fibroblasts by expressing two DKC1 shRNAs. Common changes in gene expression profile between these dyskerin-depleted cells and X-DC fibroblasts were analyzed. RESULTS Dyskerin depletion induced early activation of the p53 pathway probably secondary to ribosome biogenesis failure. However, the p53 pathway in the fibroblasts from X-DC patients was activated only after an equivalent number of passes to AD-DC fibroblasts, in which telomere attrition in each division rendered shorter telomeres than control fibroblasts. Indeed, no induction of DNA damage was observed in dyskerin-depleted fibroblasts in contrast to X-DC or AD-DC fibroblasts suggesting that DNA damage induced by telomere attrition is responsible for p53 activation in X-DC and AD-DC fibroblasts. Moreover, p53 depletion in senescent DC fibroblasts rescued their proliferative capacity and reverted the morphological changes produced after prolonged culture. CONCLUSIONS Our data indicate that ribosome biogenesis do not seem to play an important role in dyskeratosis congenita, conversely increasing DNA damage and activation of p53 pathway triggered by telomere shortening is the main activator of cell senescence.
Collapse
Affiliation(s)
- J Carrillo
- Instituto de Investigaciones Biomédicas de Madrid CSIC/UAM, IDIPaz (Biomarkers and Experimental Therapeutics Group), C/Arturo Duperier, 4, 28029, Madrid, Spain
| | | | | | | | | |
Collapse
|
33
|
Gómez DLM, Farina HG, Gómez DE. Telomerase regulation: a key to inhibition? (Review). Int J Oncol 2013; 43:1351-6. [PMID: 24042470 DOI: 10.3892/ijo.2013.2104] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Accepted: 07/05/2013] [Indexed: 11/06/2022] Open
Abstract
Telomerase has been recognized as a common factor in most tumor cells, and in turn a distinctive feature with respect to non-malignant cells. This feature has made telomerase a promising target for cancer therapy. Telomerase studies revealed that it is a multi-subunit complex possessing different levels of regulation, including control of expression, phosphorylation state, assembly and transportation to sites of activity. Thus, we emphasize that targeting telomerase expression or activity is not the only way to shorten telomeres, induce cell senescence and apoptosis. Therefore, there are multiple sites capable of allowing the modulation of its enzymatic activity. In the development of strategies based on the regulation of telomerase activity the understanding of the mechanisms regulating their subunits is essential. Based on this, in this review we summarize the current state of knowledge of some regulatory mechanisms of the components of the telomerase complex, and hypothetize their potential therapeutic application against cancer.
Collapse
Affiliation(s)
- Diego L Mengual Gómez
- Laboratory of Molecular Oncology, Science and Technology Department, National University of Quilmes, Buenos Aires, Argentina
| | | | | |
Collapse
|
34
|
Alder JK, Parry EM, Yegnasubramanian S, Wagner CL, Lieblich LM, Auerbach R, Auerbach AD, Wheelan SJ, Armanios M. Telomere phenotypes in females with heterozygous mutations in the dyskeratosis congenita 1 (DKC1) gene. Hum Mutat 2013; 34:1481-5. [PMID: 23946118 DOI: 10.1002/humu.22397] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Accepted: 08/07/2013] [Indexed: 12/28/2022]
Abstract
Dyskeratosis congenita (DC) is a telomere-mediated syndrome defined by mucocutaneous features. The X-linked mode of inheritance accounts for half the cases, and is thought to predominantly manifest in childhood as bone marrow failure. We identified two male probands who presented in the fifth decade with idiopathic pulmonary fibrosis and cancer. Their pedigrees displayed consecutively affected generations. Five of six females (83%) manifested mucocutaneous features of DC, and two had wound-healing complications. No mutations in autosomal dominant telomere genes were present, but exome sequencing revealed novel variants in the X-chromosome DKC1 gene that predicted missense mutations in conserved residues, p.Thr49Ser and p.Pro409Arg. Variants segregated with the telomere phenotype, and affected females were heterozygotes, showing skewed X-inactivation. Telomerase RNA levels were compromised in cells from DKC1 mutation carriers, consistent with their pathogenic role. These findings indicate that females with heterozygous DKC1 mutations may be at increased risk for developing penetrant telomere phenotypes that, at times, may be associated with clinical morbidity.
Collapse
Affiliation(s)
- Jonathan K Alder
- Department of Oncology and Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Simeonova I, Jaber S, Draskovic I, Bardot B, Fang M, Bouarich-Bourimi R, Lejour V, Charbonnier L, Soudais C, Bourdon JC, Huerre M, Londono-Vallejo A, Toledo F. Mutant mice lacking the p53 C-terminal domain model telomere syndromes. Cell Rep 2013; 3:2046-58. [PMID: 23770245 DOI: 10.1016/j.celrep.2013.05.028] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Revised: 04/01/2013] [Accepted: 05/17/2013] [Indexed: 11/29/2022] Open
Abstract
Mutations in p53, although frequent in human cancers, have not been implicated in telomere-related syndromes. Here, we show that homozygous mutant mice expressing p53Δ31, a p53 lacking the C-terminal domain, exhibit increased p53 activity and suffer from aplastic anemia and pulmonary fibrosis, hallmarks of syndromes caused by short telomeres. Indeed, p53Δ31/Δ31 mice had short telomeres and other phenotypic traits associated with the telomere disease dyskeratosis congenita and its severe variant the Hoyeraal-Hreidarsson syndrome. Heterozygous p53+/Δ31 mice were only mildly affected, but decreased levels of Mdm4, a negative regulator of p53, led to a dramatic aggravation of their symptoms. Importantly, several genes involved in telomere metabolism were downregulated in p53Δ31/Δ31 cells, including Dyskerin, Rtel1, and Tinf2, which are mutated in dyskeratosis congenita, and Terf1, which is implicated in aplastic anemia. Together, these data reveal that a truncating mutation can activate p53 and that p53 plays a major role in the regulation of telomere metabolism.
Collapse
Affiliation(s)
- Iva Simeonova
- Genetics of Tumor Suppression, Institut Curie, Centre de Recherche, 26 rue d'Ulm, 75248 Paris Cedex 05, France
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Kropski JA, Lawson WE, Young LR, Blackwell TS. Genetic studies provide clues on the pathogenesis of idiopathic pulmonary fibrosis. Dis Model Mech 2013; 6:9-17. [PMID: 23268535 PMCID: PMC3529334 DOI: 10.1242/dmm.010736] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Idiopathic pulmonary fibrosis (IPF) is a progressive and often fatal lung disease for which there is no known treatment. Although the traditional paradigm of IPF pathogenesis emphasized chronic inflammation as the primary driver of fibrotic remodeling, more recent insights have challenged this view. Linkage analysis and candidate gene approaches have identified four genes that cause the inherited form of IPF, familial interstitial pneumonia (FIP). These four genes encode two surfactant proteins, surfactant protein C (encoded by SFTPC) and surfactant protein A2 (SFTPA2), and two components of the telomerase complex, telomerase reverse transcriptase (TERT) and the RNA component of telomerase (TERC). In this review, we discuss how investigating these mutations, as well as genetic variants identified in other inherited disorders associated with pulmonary fibrosis, are providing new insights into the pathogenesis of common idiopathic interstitial lung diseases, particularly IPF. Studies in this area have highlighted key roles for epithelial cell injury and dysfunction in the development of lung fibrosis. In addition, genetic approaches have uncovered the importance of several processes – including endoplasmic reticulum stress and the unfolded protein response, DNA-damage and -repair pathways, and cellular senescence – that might provide new therapeutic targets in fibrotic lung diseases.
Collapse
Affiliation(s)
- Jonathan A Kropski
- Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
| | | | | | | |
Collapse
|
37
|
Brault ME, Lauzon C, Autexier C. Dyskeratosis congenita mutations in dyskerin SUMOylation consensus sites lead to impaired telomerase RNA accumulation and telomere defects. Hum Mol Genet 2013; 22:3498-507. [PMID: 23660516 DOI: 10.1093/hmg/ddt204] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Mutations in the dyskerin gene (DKC1) cause X-linked dyskeratosis congenita (DC), a rare and fatal premature aging syndrome characterized by defective telomere maintenance. Dyskerin is a highly conserved nucleolar protein, and a component of the human telomerase complex that is essential for human telomerase RNA (hTR) stability. However, its regulation remains poorly understood. Here, we report that dyskerin can be modified by small ubiquitin-like modifiers (SUMOs). We find that human DC-causing mutations in highly conserved dyskerin SUMOylation consensus sites lead to impaired hTR accumulation, telomerase activity and telomere maintenance. Finally, we show that modification of dyskerin by SUMOylation is required for its stability. Our findings provide the first evidence that dyskerin stability is regulated by SUMOylation and that mutations altering dyskerin SUMOylation can lead to defects in telomere maintenance that are characteristics of DC.
Collapse
Affiliation(s)
- Marie Eve Brault
- Bloomfield Centre for Research in Aging, Lady Davis Institute for Medical Research, Jewish General Hospital, 3775 Côte Ste Catherine Road, Montréal, QC H3T 1E2, Canada
| | | | | |
Collapse
|
38
|
Armanios M. Telomeres and age-related disease: how telomere biology informs clinical paradigms. J Clin Invest 2013; 123:996-1002. [PMID: 23454763 DOI: 10.1172/jci66370] [Citation(s) in RCA: 250] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Telomere length shortens with age and predicts the onset of replicative senescence. Recently, short telomeres have been linked to the etiology of degenerative diseases such as idiopathic pulmonary fibrosis, bone marrow failure, and cryptogenic liver cirrhosis. These disorders have recognizable clinical manifestations, and the telomere defect explains their genetics and informs the approach to their treatment. Here, I review how telomere biology has become intimately connected to clinical paradigms both for understanding pathophysiology and for individualizing therapy decisions. I also critically examine nuances of interpreting telomere length measurement in clinical studies.
Collapse
Affiliation(s)
- Mary Armanios
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, and McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA.
| |
Collapse
|
39
|
Allenspach EJ, Bellodi C, Jeong D, Kopmar N, Nakamura T, Ochs HD, Ruggero D, Skoda-Smith S, Shimamura A, Torgerson TR. Common variable immunodeficiency as the initial presentation of dyskeratosis congenita. J Allergy Clin Immunol 2013; 132:223-6. [PMID: 23403051 DOI: 10.1016/j.jaci.2012.11.052] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Revised: 10/30/2012] [Accepted: 11/21/2012] [Indexed: 12/17/2022]
|
40
|
Gardano L, Holland L, Oulton R, Le Bihan T, Harrington L. Native gel electrophoresis of human telomerase distinguishes active complexes with or without dyskerin. Nucleic Acids Res 2011; 40:e36. [PMID: 22187156 PMCID: PMC3300002 DOI: 10.1093/nar/gkr1243] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Telomeres, the ends of linear chromosomes, safeguard against genome instability. The enzyme responsible for extension of the telomere 3′ terminus is the ribonucleoprotein telomerase. Whereas telomerase activity can be reconstituted in vitro with only the telomerase RNA (hTR) and telomerase reverse transcriptase (TERT), additional components are required in vivo for enzyme assembly, stability and telomere extension activity. One such associated protein, dyskerin, promotes hTR stability in vivo and is the only component to co-purify with active, endogenous human telomerase. We used oligonucleotide-based affinity purification of hTR followed by native gel electrophoresis and in-gel telomerase activity detection to query the composition of telomerase at different purification stringencies. At low salt concentrations (0.1 M NaCl), affinity-purified telomerase was ‘supershifted’ with an anti-dyskerin antibody, however the association with dyskerin was lost after purification at 0.6 M NaCl, despite the retention of telomerase activity and a comparable yield of hTR. The interaction of purified hTR and dyskerin in vitro displayed a similar salt-sensitive interaction. These results demonstrate that endogenous human telomerase, once assembled and active, does not require dyskerin for catalytic activity. Native gel electrophoresis may prove useful in the characterization of telomerase complexes under various physiological conditions.
Collapse
Affiliation(s)
- Laura Gardano
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3JR, UK
| | | | | | | | | |
Collapse
|
41
|
Abstract
The interstitial lung diseases (ILDs), or diffuse parenchymal lung diseases, are a heterogeneous collection of more than 100 different pulmonary disorders that affect the tissue and spaces surrounding the alveoli. Patients affected by ILD usually present with shortness of breath or cough; for many, there is evidence of pulmonary restriction, decreased diffusion capacity, and radiographic appearance of alveolar and/or reticulonodular infiltrates. This article reviews the inherited ILDs, with a focus on the diseases that may be seen by pulmonologists caring for adult patients. The authors conclude by briefly discussing the utility of genetic testing in this population.
Collapse
Affiliation(s)
- Megan Stuebner Devine
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Eugene McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, TX 75390-8591, USA
| | | |
Collapse
|
42
|
Podlevsky JD, Chen JJL. It all comes together at the ends: telomerase structure, function, and biogenesis. Mutat Res 2011; 730:3-11. [PMID: 22093366 DOI: 10.1016/j.mrfmmm.2011.11.002] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Revised: 10/30/2011] [Accepted: 11/01/2011] [Indexed: 12/18/2022]
Abstract
Telomerase is a reverse transcriptase specialized in the addition of telomeric DNA repeats onto the ends of chromosomes. Telomere extension offsets the loss of telomeric repeats from the failure of DNA polymerases to fully replicate linear chromosome ends. Telomerase functions as a ribonucleoprotein, requiring an integral telomerase RNA (TR) component, in addition to the catalytic telomerase reverse transcriptase (TERT). Extensive studies have identified numerous structural and functional features within the TR and TERT essential for activity. A number of accessory proteins have also been identified with various functions in enzyme biogenesis, localization, and regulation. Understanding the molecular mechanism of telomerase function has significance for the development of therapies for telomere-mediated disorders and cancer. Here we review telomerase structural and functional features, and the techniques for assessing telomerase dysfunction.
Collapse
Affiliation(s)
- Joshua D Podlevsky
- Department of Chemistry & Biochemistry, Arizona State University, Tempe, AZ 85287-1604, USA
| | | |
Collapse
|
43
|
Abstract
Idiopathic pulmonary fibrosis (IPF) is the most common manifestation of telomere-mediated disorders. Germline mutations in the essential telomerase genes, hTERT and hTR, are the causal genetic defect in up to one-sixth of pulmonary fibrosis families. The presence of telomerase mutations in this subset is significant for clinical decisions as affected individuals can develop extra-pulmonary complications related to telomere shortening such as bone marrow failure and cryptogenic liver cirrhosis. There is also evidence that IPF is an ancestral manifestation of autosomal dominant telomere syndromes where, with successive generations, the disease evolves from pulmonary fibrosis into a bone marrow failure-predominant disorder, defining a unique form of genetic anticipation. Here I review the significance of telomere defects for understanding the genetics, disease patterns and pathophysiology of IPF. The importance of this diagnosis for patient care decisions will also be discussed.
Collapse
|
44
|
Alder JK, Guo N, Kembou F, Parry EM, Anderson CJ, Gorgy AI, Walsh MF, Sussan T, Biswal S, Mitzner W, Tuder RM, Armanios M. Telomere length is a determinant of emphysema susceptibility. Am J Respir Crit Care Med 2011; 184:904-12. [PMID: 21757622 PMCID: PMC3208661 DOI: 10.1164/rccm.201103-0520oc] [Citation(s) in RCA: 182] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Accepted: 06/30/2011] [Indexed: 01/14/2023] Open
Abstract
RATIONALE Germline mutations in the enzyme telomerase cause telomere shortening, and have their most common clinical manifestation in age-related lung disease that manifests as idiopathic pulmonary fibrosis. Short telomeres are also a unique heritable trait that is acquired with age. OBJECTIVES We sought to understand the mechanisms by which telomerase deficiency contributes to lung disease. METHODS We studied telomerase null mice with short telomeres. MEASUREMENTS AND MAIN RESULTS Although they have no baseline histologic defects, when mice with short telomeres are exposed to chronic cigarette smoke, in contrast with controls, they develop emphysematous air space enlargement. The emphysema susceptibility did not depend on circulating cell genotype, because mice with short telomeres developed emphysema even when transplanted with wild-type bone marrow. In lung epithelium, cigarette smoke exposure caused additive DNA damage to telomere dysfunction, which limited their proliferative recovery, and coincided with a failure to down-regulate p21, a mediator of cellular senescence, and we show here, a determinant of alveolar epithelial cell cycle progression. We also report early onset of emphysema, in addition to pulmonary fibrosis, in a family with a germline deletion in the Box H domain of the RNA component of telomerase. CONCLUSIONS Our data indicate that short telomeres lower the threshold of cigarette smoke-induced damage, and implicate telomere length as a genetic susceptibility factor in emphysema, potentially contributing to its age-related onset in humans.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | - Thomas Sussan
- Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland; and
| | - Shyam Biswal
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland
- Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland; and
| | - Wayne Mitzner
- Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland; and
| | - Rubin M. Tuder
- Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Denver, Aurora, Colorado
| | - Mary Armanios
- Department of Oncology
- McKusick-Nathans Institute of Genetic Medicine, and the
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland
| |
Collapse
|
45
|
A zebrafish model of dyskeratosis congenita reveals hematopoietic stem cell formation failure resulting from ribosomal protein-mediated p53 stabilization. Blood 2011; 118:5458-65. [PMID: 21921046 DOI: 10.1182/blood-2011-04-351460] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Dyskeratosis congenita (DC) is a bone marrow failure disorder characterized by shortened telomeres, defective stem cell maintenance, and highly heterogeneous phenotypes affecting predominantly tissues that require high rates of turnover. Here we present a mutant zebrafish line with decreased expression of nop10, one of the known H/ACA RNP complex genes with mutations linked to DC. We demonstrate that this nop10 loss results in 18S rRNA processing defects and collapse of the small ribosomal subunit, coupled to stabilization of the p53 tumor suppressor protein through small ribosomal proteins binding to Mdm2. These mutants also display a hematopoietic stem cell deficiency that is reversible on loss of p53 function. However, we detect no changes in telomere length in nop10 mutants. Our data support a model of DC whereupon in early development mutations involved in the H/ACA complex contribute to bone marrow failure through p53 deregulation and loss of initial stem cell numbers while their role in telomere maintenance does not contribute to DC until later in life.
Collapse
|
46
|
Nelson ND, Bertuch AA. Dyskeratosis congenita as a disorder of telomere maintenance. Mutat Res 2011; 730:43-51. [PMID: 21745483 DOI: 10.1016/j.mrfmmm.2011.06.008] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2011] [Revised: 06/16/2011] [Accepted: 06/25/2011] [Indexed: 12/11/2022]
Abstract
Since 1998, there have been great advances in our understanding of the pathogenesis of dyskeratosis congenita (DC), a rare inherited bone marrow failure and cancer predisposition syndrome with prominent mucocutaneous abnormalities and features of premature aging. DC is now characterized molecularly by the presence of short age-adjusted telomeres. Mutations in seven genes have been unequivocally associated with DC, each with a role in telomere length maintenance. These observations, combined with knowledge that progressive telomere shortening can impose a proliferative barrier on dividing cells and contribute to chromosome instability, have led to the understanding that extreme telomere shortening drives the clinical features of DC. However, some of the genes implicated in DC encode proteins that are also components of H/ACA-ribonucleoprotein enzymes, which are responsible for the post-translational modification of ribosomal and spliceosomal RNAs, raising the question whether alterations in these activities play a role in the pathogenesis of DC. In addition, recent reports suggest that some cases of DC may not be characterized by short age-adjusted telomeres. This review will highlight our current knowledge of the telomere length defects in DC and the factors involved in its development.
Collapse
Affiliation(s)
- Nya D Nelson
- Department of Molecular and Human Genetics, Texas Children's Hospital, Houston, TX 77030, USA
| | | |
Collapse
|