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Mohajer F, Khoradmehr A, Riazalhosseini B, Zendehboudi T, Nabipour I, Baghban N. In vitro detection of marine invertebrate stem cells: utilizing molecular and cellular biology techniques and exploring markers. Front Cell Dev Biol 2024; 12:1440091. [PMID: 39239558 PMCID: PMC11374967 DOI: 10.3389/fcell.2024.1440091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Accepted: 08/07/2024] [Indexed: 09/07/2024] Open
Abstract
Marine invertebrate stem cells (MISCs) represent a distinct category of pluripotent and totipotent cells with remarkable abilities for self-renewal and differentiation into multiple germ layers, akin to their vertebrate counterparts. These unique cells persist throughout an organism's adult life and have been observed in various adult marine invertebrate phyla. MISCs play crucial roles in numerous biological processes, including developmental biology phenomena specific to marine invertebrates, such as senescence, delayed senescence, whole-body regeneration, and asexual reproduction. Furthermore, they serve as valuable models for studying stem cell biology. Despite their significance, information about MISCs remains scarce and scattered in the scientific literature. In this review, we have carefully collected and summarized valuable information about MISC detection by perusing the articles that study and detect MISCs in various marine invertebrate organisms. The review begins by defining MISCs and highlighting their unique features compared to vertebrates. It then discusses the common markers for MISC detection and in vitro techniques employed in invertebrate and vertebrates investigation. This comprehensive review provides researchers and scientists with a cohesive and succinct overview of MISC characteristics, detection methods, and associated biological phenomena in marine invertebrate organisms. We aim to offer a valuable resource to researchers and scientists interested in marine invertebrate stem cells, fostering a better understanding of their broader implications in biology. With ongoing advancements in scientific techniques and the continued exploration of marine invertebrate species, we anticipate that further discoveries will expand our knowledge of MISCs and their broader implications in biology.
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Affiliation(s)
- Fatemeh Mohajer
- Student Research and Technology Committee, Bushehr University of Medical Sciences, Bushehr, Iran
| | - Arezoo Khoradmehr
- The Persian Gulf Marine Biotechnology Research Center, The Persian Gulf Biomedical Sciences Research Institute, Bushehr University of Medical Sciences, Bushehr, Iran
| | - Behnaz Riazalhosseini
- The Pharmacogenomics Laboratory, Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Tuba Zendehboudi
- Student Research and Technology Committee, Bushehr University of Medical Sciences, Bushehr, Iran
| | - Iraj Nabipour
- The Persian Gulf Marine Biotechnology Research Center, The Persian Gulf Biomedical Sciences Research Institute, Bushehr University of Medical Sciences, Bushehr, Iran
| | - Neda Baghban
- Food Control Laboratory, Food and Drug Deputy, Bushehr University of Medical Sciences, Bushehr, Iran
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2
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Shen C, Jiang K, Zhang W, Su B, Wang Z, Chen X, Zheng B, He T. LASSO regression and WGCNA-based telomerase-associated lncRNA signaling predicts clear cell renal cell carcinoma prognosis and immunotherapy response. Aging (Albany NY) 2024; 16:9386-9409. [PMID: 38819232 PMCID: PMC11210217 DOI: 10.18632/aging.205871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Accepted: 04/16/2024] [Indexed: 06/01/2024]
Abstract
OBJECTIVE To investigate whether telomerase-associated lncRNA expression affects the prognosis and anti-tumor immunity of patients with renal clear cell carcinoma (ccRCC). METHODS A series of analyses were performed to establish a prognostic risk model and validate its accuracy. Immune-related analyses were performed to assess further the association between immune status, tumor microenvironment, and prognostic risk models. RESULTS Eight telomerase-associated lncRNAs associated with prognosis were identified and applied to establish a prognostic risk model. Overall survival was higher in the low-risk group. CONCLUSION The established prognostic risk model has a good predictive ability for the prognosis of ccRCC patients and provides a new possible therapeutic target for ccRCC.
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MESH Headings
- Carcinoma, Renal Cell/genetics
- Carcinoma, Renal Cell/immunology
- Carcinoma, Renal Cell/mortality
- Carcinoma, Renal Cell/therapy
- Carcinoma, Renal Cell/metabolism
- RNA, Long Noncoding/genetics
- RNA, Long Noncoding/metabolism
- Humans
- Kidney Neoplasms/genetics
- Kidney Neoplasms/immunology
- Kidney Neoplasms/mortality
- Kidney Neoplasms/therapy
- Telomerase/genetics
- Telomerase/metabolism
- Prognosis
- Immunotherapy/methods
- Gene Expression Regulation, Neoplastic
- Tumor Microenvironment/immunology
- Tumor Microenvironment/genetics
- Biomarkers, Tumor/genetics
- Biomarkers, Tumor/metabolism
- Signal Transduction/genetics
- Male
- Female
- Gene Regulatory Networks
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Affiliation(s)
- Cheng Shen
- Department of Urology, The Second Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, China
- Medical Research Center, The Second Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, China
| | - Kaiyao Jiang
- Department of Urology, The Second Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, China
- Medical Research Center, The Second Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, China
| | - Wei Zhang
- Department of Urology, The Second Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, China
| | - Baohui Su
- Department of Urology, The Second Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, China
- Medical Research Center, The Second Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, China
| | - Zhenyu Wang
- Department of Urology, The Second Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, China
| | - Xinfeng Chen
- Department of Urology, The Second Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, China
| | - Bing Zheng
- Department of Urology, The Second Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, China
| | - Tao He
- Party Committe and Hospital Administration Office, The Second Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, China
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Karimian K, Groot A, Huso V, Kahidi R, Tan KT, Sholes S, Keener R, McDyer JF, Alder JK, Li H, Rechtsteiner A, Greider CW. Human telomere length is chromosome end-specific and conserved across individuals. Science 2024; 384:533-539. [PMID: 38603523 DOI: 10.1126/science.ado0431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Accepted: 03/30/2024] [Indexed: 04/13/2024]
Abstract
Short telomeres cause age-related disease, and long telomeres contribute to cancer; however, the mechanisms regulating telomere length are unclear. We developed a nanopore-based method, which we call Telomere Profiling, to determine telomere length at nearly single-nucleotide resolution. Mapping telomere reads to chromosome ends showed chromosome end-specific length distributions that could differ by more than six kilobases. Examination of telomere lengths in 147 individuals revealed that certain chromosome ends were consistently longer or shorter. The same rank order was found in newborn cord blood, suggesting that telomere length is determined at birth and that chromosome end-specific telomere length differences are maintained as telomeres shorten with age. Telomere Profiling makes precision investigation of telomere length widely accessible for laboratory, clinical, and drug discovery efforts and will allow deeper insights into telomere biology.
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Affiliation(s)
- Kayarash Karimian
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Biochemistry, Cellular and Molecular Biology Graduate Program, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Aljona Groot
- Department of Molecular Cell and Developmental Biology, University of California, Santa Cruz, CA, USA
| | - Vienna Huso
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Biochemistry, Cellular and Molecular Biology Graduate Program, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Ramin Kahidi
- Health Sciences Program, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Kar-Tong Tan
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- Cancer Program, The Broad Institute, Cambridge, MA, USA
| | - Samantha Sholes
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Biochemistry, Cellular and Molecular Biology Graduate Program, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Rebecca Keener
- Biochemistry, Cellular and Molecular Biology Graduate Program, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - John F McDyer
- Pulmonary, Allergy, Critical Care, and Sleep Medicine Division, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jonathan K Alder
- Pulmonary, Allergy, Critical Care, and Sleep Medicine Division, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Heng Li
- Department of Data Sciences, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Biomedical Informatics, Harvard Medical School, Boston, MA, USA
| | - Andreas Rechtsteiner
- Department of Molecular Cell and Developmental Biology, University of California, Santa Cruz, CA, USA
| | - Carol W Greider
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Molecular Cell and Developmental Biology, University of California, Santa Cruz, CA, USA
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Ghanim GE, Sekne Z, Balch S, van Roon AMM, Nguyen THD. 2.7 Å cryo-EM structure of human telomerase H/ACA ribonucleoprotein. Nat Commun 2024; 15:746. [PMID: 38272871 PMCID: PMC10811338 DOI: 10.1038/s41467-024-45002-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 01/03/2024] [Indexed: 01/27/2024] Open
Abstract
Telomerase is a ribonucleoprotein (RNP) enzyme that extends telomeric repeats at eukaryotic chromosome ends to counterbalance telomere loss caused by incomplete genome replication. Human telomerase is comprised of two distinct functional lobes tethered by telomerase RNA (hTR): a catalytic core, responsible for DNA extension; and a Hinge and ACA (H/ACA) box RNP, responsible for telomerase biogenesis. H/ACA RNPs also have a general role in pseudouridylation of spliceosomal and ribosomal RNAs, which is critical for the biogenesis of the spliceosome and ribosome. Much of our structural understanding of eukaryotic H/ACA RNPs comes from structures of the human telomerase H/ACA RNP. Here we report a 2.7 Å cryo-electron microscopy structure of the telomerase H/ACA RNP. The significant improvement in resolution over previous 3.3 Å to 8.2 Å structures allows us to uncover new molecular interactions within the H/ACA RNP. Many disease mutations are mapped to these interaction sites. The structure also reveals unprecedented insights into a region critical for pseudouridylation in canonical H/ACA RNPs. Together, our work advances understanding of telomerase-related disease mutations and the mechanism of pseudouridylation by eukaryotic H/ACA RNPs.
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Affiliation(s)
| | - Zala Sekne
- MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK
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Karimian K, Groot A, Huso V, Kahidi R, Tan KT, Sholes S, Keener R, McDyer JF, Alder JK, Li H, Rechtsteiner A, Greider CW. Human telomere length is chromosome specific and conserved across individuals. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.12.21.572870. [PMID: 38187739 PMCID: PMC10769321 DOI: 10.1101/2023.12.21.572870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Short telomeres cause age-related disease and long telomeres predispose to cancer; however, the mechanisms regulating telomere length are unclear. To probe these mechanisms, we developed a nanopore sequencing method, Telomere Profiling, that is easy to implement, precise, and cost effective with broad applications in research and the clinic. We sequenced telomeres from individuals with short telomere syndromes and found similar telomere lengths to the clinical FlowFISH assay. We mapped telomere reads to specific chromosome end and identified both chromosome end-specific and haplotype-specific telomere length distributions. In the T2T HG002 genome, where the average telomere length is 5kb, we found a remarkable 6kb difference in lengths between some telomeres. Further, we found that specific chromosome ends were consistently shorter or longer than the average length across 147 individuals. The presence of conserved chromosome end-specific telomere lengths suggests there are new paradigms in telomere biology that are yet to be explored. Understanding the mechanisms regulating length will allow deeper insights into telomere biology that can lead to new approaches to disease.
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Affiliation(s)
- Kayarash Karimian
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Biochemistry, Cellular and Molecular Biology Graduate Program, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Aljona Groot
- Department of Molecular Cell and Developmental Biology, University of California, Santa Cruz
| | - Vienna Huso
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Biochemistry, Cellular and Molecular Biology Graduate Program, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | | | - Kar-Tong Tan
- Harvard Medical School, Department of Genetics, Boston, MA
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA
- Broad Institute, Cancer Program, Cambridge, MA
| | - Samantha Sholes
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Biochemistry, Cellular and Molecular Biology Graduate Program, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Present address Merck & Co., 770 Sumneytown Pike, West Point, PA 19486
| | - Rebecca Keener
- Department of Biomedical Engineering, Johns Hopkins University
| | - John F. McDyer
- Pulmonary, Allergy, Critical Care, and Sleep Medicine Division, Department of Medicine, University of Pittsburgh
| | - Jonathan K. Alder
- Pulmonary, Allergy, Critical Care, and Sleep Medicine Division, Department of Medicine, University of Pittsburgh
| | - Heng Li
- Dana-Farber Cancer Institute, Department of Data Sciences, Boston, MA
- Harvard Medical School, Department of Biomedical Informatics, Boston, MA
| | - Andreas Rechtsteiner
- Department of Molecular Cell and Developmental Biology, University of California, Santa Cruz
| | - Carol W. Greider
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Department of Molecular Cell and Developmental Biology, University of California, Santa Cruz
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Özmaldar A, Balta B. Formation and Effects of Upstream DNA-RNA Base Pairing in Telomerase. Chembiochem 2023; 24:e202300501. [PMID: 37743538 DOI: 10.1002/cbic.202300501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 09/04/2023] [Accepted: 09/22/2023] [Indexed: 09/26/2023]
Abstract
Telomere elongation by telomerase consists of two types of translocation: duplex translocation during each repeat synthesis and template translocation at the end of repeat synthesis. Our replica exchange molecular dynamics simulations show that in addition to the Watson-Crick interactions in the active site, templating RNA can also form base pairs with the upstream regions of DNA, mostly with the second upstream DNA repeat with respect to the 3'-end. At the end of the repeat synthesis, dG10-P442 and dG11-N446 hydrogen bonds form. Then, active-site base pairs dissociate one by one, and the RNA bases reanneal with the complementary base on the upstream DNA repeat. For each dissociating base pair a new one forms, thus conserving the number of base pairs during template translocation.
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Affiliation(s)
- Aydın Özmaldar
- Department of Molecular Biology and Genetics, Istanbul Technical University, Maslak, 34469, Istanbul, Turkey
| | - Bülent Balta
- Department of Molecular Biology and Genetics, Istanbul Technical University, Maslak, 34469, Istanbul, Turkey
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Wu P, Gan Q, Zhang X, Yang Y, Xiao Y, She Q, Ni J, Huang Q, Shen Y. The archaeal KEOPS complex possesses a functional Gon7 homolog and has an essential function independent of the cellular t 6A modification level. MLIFE 2023; 2:11-27. [PMID: 38818338 PMCID: PMC10989989 DOI: 10.1002/mlf2.12051] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Accepted: 11/29/2022] [Indexed: 06/01/2024]
Abstract
Kinase, putative Endopeptidase, and Other Proteins of Small size (KEOPS) is a multisubunit protein complex conserved in eukaryotes and archaea. It is composed of Pcc1, Kae1, Bud32, Cgi121, and Gon7 in eukaryotes and is primarily involved in N6-threonylcarbamoyl adenosine (t6A) modification of transfer RNAs (tRNAs). Recently, it was reported that KEOPS participates in homologous recombination (HR) repair in yeast. To characterize the KEOPS in archaea (aKEOPS), we conducted genetic and biochemical analyses of its encoding genes in the hyperthermophilic archaeon Saccharolobus islandicus. We show that aKEOPS also possesses five subunits, Pcc1, Kae1, Bud32, Cgi121, and Pcc1-like (or Gon7-like), just like eukaryotic KEOPS. Pcc1-like has physical interactions with Kae1 and Pcc1 and can mediate the monomerization of the dimeric subcomplex (Kae1-Pcc1-Pcc1-Kae1), suggesting that Pcc1-like is a functional homolog of the eukaryotic Gon7 subunit. Strikingly, none of the genes encoding aKEOPS subunits, including Pcc1 and Pcc1-like, can be deleted in the wild type and in a t6A modification complementary strain named TsaKI, implying that the aKEOPS complex is essential for an additional cellular process in this archaeon. Knock-down of the Cgi121 subunit leads to severe growth retardance in the wild type that is partially rescued in TsaKI. These results suggest that aKEOPS plays an essential role independent of the cellular t6A modification level. In addition, archaeal Cgi121 possesses dsDNA-binding activity that relies on its tRNA 3' CCA tail binding module. Our study clarifies the subunit organization of archaeal KEOPS and suggests an origin of eukaryotic Gon7. The study also reveals a possible link between the function in t6A modification and the additional function, presumably HR.
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Affiliation(s)
- Pengju Wu
- State Key Laboratory of Microbial Technology, CRISPR and Archaea Biology Research Center, Microbial Technology InstituteShandong UniversityQingdaoChina
| | - Qi Gan
- State Key Laboratory of Microbial Technology, CRISPR and Archaea Biology Research Center, Microbial Technology InstituteShandong UniversityQingdaoChina
| | - Xuemei Zhang
- State Key Laboratory of Microbial Technology, CRISPR and Archaea Biology Research Center, Microbial Technology InstituteShandong UniversityQingdaoChina
| | - Yunfeng Yang
- State Key Laboratory of Microbial Technology, CRISPR and Archaea Biology Research Center, Microbial Technology InstituteShandong UniversityQingdaoChina
| | - Yuanxi Xiao
- State Key Laboratory of Microbial Technology, CRISPR and Archaea Biology Research Center, Microbial Technology InstituteShandong UniversityQingdaoChina
| | - Qunxin She
- State Key Laboratory of Microbial Technology, CRISPR and Archaea Biology Research Center, Microbial Technology InstituteShandong UniversityQingdaoChina
| | - Jinfeng Ni
- State Key Laboratory of Microbial Technology, CRISPR and Archaea Biology Research Center, Microbial Technology InstituteShandong UniversityQingdaoChina
| | - Qihong Huang
- State Key Laboratory of Microbial Technology, CRISPR and Archaea Biology Research Center, Microbial Technology InstituteShandong UniversityQingdaoChina
| | - Yulong Shen
- State Key Laboratory of Microbial Technology, CRISPR and Archaea Biology Research Center, Microbial Technology InstituteShandong UniversityQingdaoChina
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Feng J, Tang X, Song L, Zhou Z, Jiang Y, Huang Y. A telomerase regulation-related lncRNA signature predicts prognosis and immunotherapy response for gastric cancer. J Cancer Res Clin Oncol 2023; 149:135-146. [PMID: 36333566 DOI: 10.1007/s00432-022-04456-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2022] [Accepted: 10/27/2022] [Indexed: 11/07/2022]
Abstract
BACKGROUND Telomeres are involved in the development and progression of gastric cancer (GC). However, the association of telomerase regulation-related lncRNAs with prognosis and immunotherapy responsiveness in gastric cancer is unclear. METHODS This study systematically evaluated the relationship between lncRNAs co-expressed with 67 telomerase regulatory genes and gastric cancer prognosis. The risk scores of the samples were calculated based on telomerase regulation-related lncRNAs with prognostic value, and the samples were classified into high-/low-risk groups. The prognostic value of risk groups was then evaluated, a GC prognostic prediction model based on risk groups and clinical characteristics was established, and the prediction accuracy of the model was clarified by receiving operating characteristic (ROC) curves and calibration curves. Finally, the value of risk grouping in GC immunotherapy sensitivity was predicted by comparing MSI status and tumor mutation load between the high- and low-risk groups. RESULTS We identified 13 lncRNAs with prognostic value co-expressed with telomerase regulatory genes and observed that the prognosis of the low-risk group was significantly better than that of the high-risk group. Meanwhile, a GC overall survival (OS) prediction model based on risk grouping and clinical characteristics was developed, and ROC curves and calibration curves confirmed the good predictive ability of the model. In addition, the low-risk group exhibited a higher tumor mutation load and MSI-H, suggesting a possible benefit of immunotherapy. CONCLUSION We found that telomerase regulation-related lncRNAs have prognostic value in GC patients and contribute to the exploration of more effective immunotherapeutic strategies.
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Affiliation(s)
- Jinggao Feng
- Department of Gastrointestinal and Anorectal Surgery, The Central Hospital of Yongzhou, No. 151, Xiaoshui West Road, Lingling District, Yongzhou, 425100, Hunan Province, China.
| | - Xiayu Tang
- Department of Gastrointestinal and Anorectal Surgery, The Central Hospital of Yongzhou, No. 151, Xiaoshui West Road, Lingling District, Yongzhou, 425100, Hunan Province, China
| | - Liusong Song
- Department of Gastrointestinal and Anorectal Surgery, The Central Hospital of Yongzhou, No. 151, Xiaoshui West Road, Lingling District, Yongzhou, 425100, Hunan Province, China
| | - Zhipeng Zhou
- Department of Gastrointestinal and Anorectal Surgery, The Central Hospital of Yongzhou, No. 151, Xiaoshui West Road, Lingling District, Yongzhou, 425100, Hunan Province, China
| | - Yuan Jiang
- Department of Gastrointestinal and Anorectal Surgery, The Central Hospital of Yongzhou, No. 151, Xiaoshui West Road, Lingling District, Yongzhou, 425100, Hunan Province, China
| | - Yao Huang
- Department of Gastrointestinal and Anorectal Surgery, The Central Hospital of Yongzhou, No. 151, Xiaoshui West Road, Lingling District, Yongzhou, 425100, Hunan Province, China
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Pepke ML, Eisenberg DTA. On the comparative biology of mammalian telomeres: Telomere length co-evolves with body mass, lifespan and cancer risk. Mol Ecol 2022; 31:6286-6296. [PMID: 33662151 DOI: 10.1111/mec.15870] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 02/23/2021] [Indexed: 01/31/2023]
Abstract
Telomeres, the short repetitive DNA sequences that cap the ends of linear chromosomes, shorten during cell division and are implicated in senescence in most species. Telomerase can rebuild telomeres but is repressed in many mammals that exhibit replicative senescence, presumably as a tumour suppression mechanism. It is therefore important to understand the co-evolution of telomere biology and life-history traits that has shaped the diversity of senescence patterns across species. Gomes et al. previously produced a large data set on telomere length (TL), telomerase activity, body mass and lifespan among 57 mammal species. We re-analysed their data using the same phylogenetic multiple regressions and with several additional analyses to test the robustness of the findings. We found substantial inconsistencies in our results compared to Gomes et al.'s. Consistent with Gomes et al. we found an inverse association between TL and lifespan. Contrary to the analyses in Gomes et al., we found a generally robust inverse association between TL and mass, and only weak nonrobust evidence for an association between telomerase activity and mass. These results suggest that shorter TL may have been selected for in larger and longer lived species, probably as a mechanism to suppress cancer. We support this hypothesis by showing that longer telomeres predict higher cancer risk across 22 species. Furthermore, we find that domesticated species have longer telomeres. Our results call into question past interpretations of the co-evolution of telomere biology and life-history traits and stress the need for careful attention to model construction.
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Affiliation(s)
- Michael Le Pepke
- Department of Biology, Centre for Biodiversity Dynamics (CBD), Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Dan T A Eisenberg
- Department of Anthropology, University of Washington, Seattle, WA, USA.,Center for Studies in Demography and Ecology, University of Washington, Seattle, WA, USA.,Department of Biology, University of Washington, Seattle, WA, USA
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Hong X, Wang L, Zhang K, Liu J, Liu JP. Molecular Mechanisms of Alveolar Epithelial Stem Cell Senescence and Senescence-Associated Differentiation Disorders in Pulmonary Fibrosis. Cells 2022; 11:877. [PMID: 35269498 PMCID: PMC8909789 DOI: 10.3390/cells11050877] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 03/01/2022] [Accepted: 03/02/2022] [Indexed: 02/04/2023] Open
Abstract
Pulmonary senescence is accelerated by unresolved DNA damage response, underpinning susceptibility to pulmonary fibrosis. Recently it was reported that the SARS-Cov-2 viral infection induces acute pulmonary epithelial senescence followed by fibrosis, although the mechanism remains unclear. Here, we examine roles of alveolar epithelial stem cell senescence and senescence-associated differentiation disorders in pulmonary fibrosis, exploring the mechanisms mediating and preventing pulmonary fibrogenic crisis. Notably, the TGF-β signalling pathway mediates alveolar epithelial stem cell senescence by mechanisms involving suppression of the telomerase reverse transcriptase gene in pulmonary fibrosis. Alternatively, telomere uncapping caused by stress-induced telomeric shelterin protein TPP1 degradation mediates DNA damage response, pulmonary senescence and fibrosis. However, targeted intervention of cellular senescence disrupts pulmonary remodelling and fibrosis by clearing senescent cells using senolytics or preventing senescence using telomere dysfunction inhibitor (TELODIN). Studies indicate that the development of senescence-associated differentiation disorders is reprogrammable and reversible by inhibiting stem cell replicative senescence in pulmonary fibrosis, providing a framework for targeted intervention of the molecular mechanisms of alveolar stem cell senescence and pulmonary fibrosis. Abbreviations: DPS, developmental programmed senescence; IPF, idiopathic pulmonary fibrosis; OIS, oncogene-induced replicative senescence; SADD, senescence-associated differentiation disorder; SALI, senescence-associated low-grade inflammation; SIPS, stress-induced premature senescence; TERC, telomerase RNA component; TERT, telomerase reverse transcriptase; TIFs, telomere dysfunction-induced foci; TIS, therapy-induced senescence; VIS, virus-induced senescence.
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Affiliation(s)
- Xiaojing Hong
- Institute of Ageing Research, Hangzhou Normal University School of Medicine, Hangzhou 311121, China; (X.H.); (L.W.); (K.Z.); (J.L.)
| | - Lihui Wang
- Institute of Ageing Research, Hangzhou Normal University School of Medicine, Hangzhou 311121, China; (X.H.); (L.W.); (K.Z.); (J.L.)
| | - Kexiong Zhang
- Institute of Ageing Research, Hangzhou Normal University School of Medicine, Hangzhou 311121, China; (X.H.); (L.W.); (K.Z.); (J.L.)
| | - Jun Liu
- Institute of Ageing Research, Hangzhou Normal University School of Medicine, Hangzhou 311121, China; (X.H.); (L.W.); (K.Z.); (J.L.)
| | - Jun-Ping Liu
- Institute of Ageing Research, Hangzhou Normal University School of Medicine, Hangzhou 311121, China; (X.H.); (L.W.); (K.Z.); (J.L.)
- Department of Immunology and Pathology, Monash University Faculty of Medicine, Prahran, VIC 3181, Australia
- Hudson Institute of Medical Research, Monash University Department of Molecular and Translational Science, Clayton, VIC 3168, Australia
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Poláková E, Albanaz ATS, Zakharova A, Novozhilova TS, Gerasimov ES, Yurchenko V. Ku80 is involved in telomere maintenance but dispensable for genomic stability in Leishmania mexicana. PLoS Negl Trop Dis 2021; 15:e0010041. [PMID: 34965251 PMCID: PMC8716037 DOI: 10.1371/journal.pntd.0010041] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 11/30/2021] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Telomeres are indispensable for genome stability maintenance. They are maintained by the telomere-associated protein complex, which include Ku proteins and a telomerase among others. Here, we investigated a role of Ku80 in Leishmania mexicana. Leishmania is a genus of parasitic protists of the family Trypanosomatidae causing a vector-born disease called leishmaniasis. METHODOLOGY/PRINCIPAL FINDINGS We used the previously established CRISPR/Cas9 system to mediate ablation of Ku80- and Ku70-encoding genes in L. mexicana. Complete knock-outs of both genes were confirmed by Southern blotting, whole-genome Illumina sequencing, and RT-qPCR. Resulting telomeric phenotypes were subsequently investigated using Southern blotting detection of terminal restriction fragments. The genome integrity in the Ku80- deficient cells was further investigated by whole-genome sequencing. Our work revealed that telomeres in the ΔKu80 L. mexicana are elongated compared to those of the wild type. This is a surprising finding considering that in another model trypanosomatid, Trypanosoma brucei, they are shortened upon ablation of the same gene. A telomere elongation phenotype has been documented in other species and associated with a presence of telomerase-independent alternative telomere lengthening pathway. Our results also showed that Ku80 appears to be not involved in genome stability maintenance in L. mexicana. CONCLUSION/SIGNIFICANCE Ablation of the Ku proteins in L. mexicana triggers telomere elongation, but does not have an adverse impact on genome integrity.
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Affiliation(s)
- Ester Poláková
- Life Science Research Centre, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - Amanda T. S. Albanaz
- Life Science Research Centre, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - Alexandra Zakharova
- Life Science Research Centre, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | | | - Evgeny S. Gerasimov
- Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow, Russia
- Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, Russia
| | - Vyacheslav Yurchenko
- Life Science Research Centre, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
- Martsinovsky Institute of Medical Parasitology, Tropical and Vector Borne Diseases, Sechenov University, Moscow, Russia
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12
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Zeid D, Mooney-Leber S, Seemiller LR, Goldberg LR, Gould TJ. Terc Gene Cluster Variants Predict Liver Telomere Length in Mice. Cells 2021; 10:2623. [PMID: 34685603 PMCID: PMC8533930 DOI: 10.3390/cells10102623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 09/19/2021] [Accepted: 09/30/2021] [Indexed: 11/16/2022] Open
Abstract
Variants in a gene cluster upstream-adjacent to TERC on human chromosome 3, which includes genes APRM, LRRC31, LRRC34 and MYNN, have been associated with telomere length in several human populations. Currently, the mechanism by which variants in the TERC gene cluster influence telomere length in humans is unknown. Given the proximity between the TERC gene cluster and TERC (~0.05 Mb) in humans, it is speculated that cluster variants are in linkage disequilibrium with a TERC causal variant. In mice, the Terc gene/Terc gene cluster are also located on chromosome 3; however, the Terc gene cluster is located distantly downstream of Terc (~60 Mb). Here, we initially aim to investigate the interactions between genotype and nicotine exposure on absolute liver telomere length (aTL) in a panel of eight inbred mouse strains. Although we found no significant impact of nicotine on liver aTL, this first experiment identified candidate single nucleotide polymorphisms (SNPs) in the murine Terc gene cluster (within genes Lrrc31, Lrriq4 and Mynn) co-varying with aTL in our panel. In a second experiment, we tested the association of these Terc gene cluster variants with liver aTL in an independent panel of eight inbred mice selected based on candidate SNP genotype. This supported our initial finding that Terc gene cluster polymorphisms impact aTL in mice, consistent with data in human populations. This provides support for mice as a model for telomere dynamics, especially for studying mechanisms underlying the association between Terc cluster variants and telomere length. Finally, these data suggest that mechanisms independent of linkage disequilibrium between the Terc/TERC gene cluster and the Terc/TERC gene mediate the cluster's regulation of telomere length.
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Affiliation(s)
- Dana Zeid
- Department of Biobehavioral Health, Penn State University, University Park, PA 16802, USA; (L.R.S.); (L.R.G.); (T.J.G.)
| | - Sean Mooney-Leber
- Department of Psychology, University of Wisconsin-Stevens Point, Stevens Point, WI 54481, USA;
| | - Laurel R. Seemiller
- Department of Biobehavioral Health, Penn State University, University Park, PA 16802, USA; (L.R.S.); (L.R.G.); (T.J.G.)
| | - Lisa R. Goldberg
- Department of Biobehavioral Health, Penn State University, University Park, PA 16802, USA; (L.R.S.); (L.R.G.); (T.J.G.)
| | - Thomas J. Gould
- Department of Biobehavioral Health, Penn State University, University Park, PA 16802, USA; (L.R.S.); (L.R.G.); (T.J.G.)
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13
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Kordowitzki P. Oxidative Stress Induces Telomere Dysfunction and Shortening in Human Oocytes of Advanced Age Donors. Cells 2021; 10:cells10081866. [PMID: 34440635 PMCID: PMC8391391 DOI: 10.3390/cells10081866] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 07/13/2021] [Accepted: 07/22/2021] [Indexed: 12/12/2022] Open
Abstract
Research from the past decades provided strong evidence that in humans the pool of oocytes starts to decline already before the birth of a female individual, and from menarche to menopause the oocyte is exposed to different environmental stimuli. Since more and more women of the 21st century in developed countries wish to postpone the first pregnancy to their thirties, higher rates of miscarriage and chromosomal non-disjunction might occur. In oocytes of advanced maternal age, meaning above 35 years of age, characteristics such as chromosomal instabilities/abnormalities, spindle defects, decreased mitochondrial function and telomere shortening become more prevalent than in younger counterparts. Telomere attrition belongs to the so-called “hallmarks of aging” which are also relevant for the female germ-line cells. In oocytes, telomeres shorten with advancing maternal age due to the effects of reactive oxygen species and not upon replicative senescence, similar to how it is common in dividing cells.
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Affiliation(s)
- Paweł Kordowitzki
- Institute of Animal Reproduction and Food Research of Polish Academy of Sciences, Tuwima Street 10, 10-243 Olsztyn, Poland
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14
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Petrov N, Lee HS, Liskovykh M, Teulade-Fichou MP, Masumoto H, Earnshaw WC, Pommier Y, Larionov V, Kouprina N. Terpyridine platinum compounds induce telomere dysfunction and chromosome instability in cancer cells. Oncotarget 2021; 12:1444-1456. [PMID: 34316326 PMCID: PMC8310675 DOI: 10.18632/oncotarget.28020] [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: 04/13/2021] [Accepted: 06/22/2021] [Indexed: 11/25/2022] Open
Abstract
Telomerase/telomere-targeting therapy is a potentially promising approach for cancer treatment because even transient telomere dysfunction can induce chromosomal instability (CIN) and may be a barrier to tumor growth. We recently developed a dual-HAC (Human Artificial Chromosome) assay that enables identification and ranking of compounds that induce CIN as a result of telomere dysfunction. This assay is based on the use of two isogenic HT1080 cell lines, one carrying a linear HAC (containing telomeres) and the other carrying a circular HAC (lacking telomeres). Disruption of telomeres in response to drug treatment results in specific destabilization of the linear HAC. Results: In this study, we used the dual-HAC assay for the analysis of the platinum-derived G4 ligand Pt-tpy and five of its derivatives: Pt-cpym, Pt-vpym, Pt-ttpy, Pt(PA)-tpy, and Pt-BisQ. Our analysis revealed four compounds, Pt-tpy, Pt-ttpy, Pt-vpym and Pt-cpym, that induce a specific loss of a linear but not a circular HAC. Increased CIN after treatment by these compounds correlates with the induction of double-stranded breaks (DSBs) predominantly localized at telomeres and reflecting telomere-associated DNA damage. Analysis of the mitotic phenotypes induced by these drugs revealed an elevated rate of chromatin bridges (CBs) in late mitosis and cytokinesis. These terpyridine platinum-derived G4 ligands are promising compounds for cancer treatment.
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Affiliation(s)
- Nikolai Petrov
- Developmental Therapeutics Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Hee-Sheung Lee
- Developmental Therapeutics Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Mikhail Liskovykh
- Developmental Therapeutics Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Marie-Paule Teulade-Fichou
- Chemistry and Modelling for the Biology of Cancer, CNRS UMR 9187-INSERM U1196 Institute Curie, Research Center, Campus University Paris-Saclay, Orsay, France
| | - Hiroshi Masumoto
- Laboratory of Chromosome Engineering, Department of Frontier Research and Development, Kazusa DNA Research Institute, Kisarazu, Chiba 292-0818, Japan
| | - William C Earnshaw
- Wellcome Centre for Cell Biology, School of Biological Sciences, King's Buildings, University of Edinburgh, Max Born Crescent, Edinburgh EH9 3BF, Scotland
| | - Yves Pommier
- Developmental Therapeutics Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Vladimir Larionov
- Developmental Therapeutics Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Natalay Kouprina
- Developmental Therapeutics Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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15
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Subasri M, Shooshtari P, Watson AJ, Betts DH. Analysis of TERT Isoforms across TCGA, GTEx and CCLE Datasets. Cancers (Basel) 2021; 13:cancers13081853. [PMID: 33924498 PMCID: PMC8070023 DOI: 10.3390/cancers13081853] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 04/01/2021] [Accepted: 04/08/2021] [Indexed: 12/14/2022] Open
Abstract
Reactivation of the multi-subunit ribonucleoprotein telomerase is the primary telomere maintenance mechanism in cancer, but it is rate-limited by the enzymatic component, telomerase reverse transcriptase (TERT). While regulatory in nature, TERT alternative splice variant/isoform regulation and functions are not fully elucidated and are further complicated by their highly diverse expression and nature. Our primary objective was to characterize TERT isoform expression across 7887 neoplastic and 2099 normal tissue samples using The Cancer Genome Atlas (TCGA) and the Genotype-Tissue Expression Project (GTEx), respectively. We confirmed the global overexpression and splicing shift towards full-length TERT in neoplastic tissue. Stratifying by tissue type we found uncharacteristic TERT expression in normal brain tissue subtypes. Stratifying by tumor-specific subtypes, we detailed TERT expression differences potentially regulated by subtype-specific molecular characteristics. Focusing on β-deletion splicing regulation, we found the NOVA1 trans-acting factor to mediate alternative splicing in a cancer-dependent manner. Of relevance to future tissue-specific studies, we clustered cancer cell lines with tumors from related origin based on TERT isoform expression patterns. Taken together, our work has reinforced the need for tissue and tumour-specific TERT investigations, provided avenues to do so, and brought to light the current technical limitations of bioinformatic analyses of TERT isoform expression.
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Affiliation(s)
- Mathushan Subasri
- Department of Physiology and Pharmacology, The University of Western Ontario, London, ON N6A 5C1, Canada; (M.S.); (A.J.W.)
| | - Parisa Shooshtari
- Ontario Institute for Cancer Research, Toronto, ON M5G 0A3, Canada;
- Department of Pathology and Laboratory Medicine, The University of Western Ontario, London, ON N6A 5C1, Canada
- Department of Computer Science, The University of Western Ontario, London, ON N6A 5C1, Canada
- The Children’s Health Research Institute—Lawson Health Research Institute, London, ON N6C 2R5, Canada
| | - Andrew J. Watson
- Department of Physiology and Pharmacology, The University of Western Ontario, London, ON N6A 5C1, Canada; (M.S.); (A.J.W.)
- The Children’s Health Research Institute—Lawson Health Research Institute, London, ON N6C 2R5, Canada
- Department of Obstetrics and Gynaecology, The University of Western Ontario, London, ON N6A 5C1, Canada
| | - Dean H. Betts
- Department of Physiology and Pharmacology, The University of Western Ontario, London, ON N6A 5C1, Canada; (M.S.); (A.J.W.)
- The Children’s Health Research Institute—Lawson Health Research Institute, London, ON N6C 2R5, Canada
- Department of Obstetrics and Gynaecology, The University of Western Ontario, London, ON N6A 5C1, Canada
- Correspondence: ; Tel.: +1-519-661-2111 (ext. 83786)
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16
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Stone RC, Aviv A, Paus R. Telomere Dynamics and Telomerase in the Biology of Hair Follicles and their Stem Cells as a Model for Aging Research. J Invest Dermatol 2021; 141:1031-1040. [PMID: 33509633 DOI: 10.1016/j.jid.2020.12.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 11/28/2020] [Accepted: 12/01/2020] [Indexed: 02/06/2023]
Abstract
In this review, we propose that telomere length dynamics play an important but underinvestigated role in the biology of the hair follicle (HF), a prototypic, cyclically remodeled miniorgan that shows an intriguing aging pattern in humans. Whereas the HF pigmentary unit ages quickly, its epithelial stem cell (ESC) component and regenerative capacity are surprisingly aging resistant. Telomerase-deficient mice with short telomeres display an aging phenotype of hair graying and hair loss that is attributed to impaired HF ESC mobilization. Yet, it remains unclear whether the function of telomerase and telomeres in murine HF biology translate to the human system. Therefore, we propose new directions for future telomere research of the human HF. Such research may guide the development of novel treatments for selected disorders of human hair growth or pigmentation (e.g., chemotherapy-induced alopecia, telogen effluvium, androgenetic alopecia, cicatricial alopecia, graying). It might also increase the understanding of the global role of telomeres in aging-related human disease.
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Affiliation(s)
- Rivka C Stone
- Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, Florida, USA.
| | - Abraham Aviv
- The Center of Human Development and Aging, Rutgers New Jersey Medical School, Newark, New Jersey, USA
| | - Ralf Paus
- Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, Florida, USA; Centre for Dermatology Research, University of Manchester, Manchester, United Kingdom; Monasterium Laboratory, Münster, Germany
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17
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Abstract
Telomeres are the ends of linear eukaryotic chromosomes facilitating the resolution of the ‘end replication and protection’ problems, associated with linearity. At the nucleotide level, telomeres typically represent stretches of tandemly arranged telomeric repeats, which vary in length and sequence among different groups of organisms. Recently, a composition of the telomere-associated protein complex has been scrutinized in Trypanosoma brucei. In this work, we subjected proteins from that list to a more detailed bioinformatic analysis and delineated a core set of 20 conserved proteins putatively associated with telomeres in trypanosomatids. Out of these, two proteins (Ku70 and Ku80) are conspicuously missing in representatives of the genus Blastocrithidia, yet telomeres in these species do not appear to be affected. In this work, based on the analysis of a large set of trypanosomatids widely different in their phylogenetic position and life strategies, we demonstrated that telomeres of trypanosomatids are diverse in length, even within groups of closely related species. Our analysis showed that the expression of two proteins predicted to be associated with telomeres (those encoding telomerase and telomere-associated hypothetical protein orthologous to Tb927.6.4330) may directly affect and account for the differences in telomere length within the species of the Leishmania mexicana complex.
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18
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Effects chronic administration of corticosterone and estrogen on HPA axis activity and telomere length in brain areas of female rats. Brain Res 2020; 1750:147152. [PMID: 33049239 DOI: 10.1016/j.brainres.2020.147152] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 10/02/2020] [Accepted: 10/06/2020] [Indexed: 11/20/2022]
Abstract
Chronic stress is related to the acceleration of telomere shortening. Recent work showed a correlation between chronic psychosocial stress and reduced telomere length in certain cells. The exposure of T lymphocytes to cortisol promoted a significant reduction in telomerase activity. Although stress can promote changes in telomere length, whether increased glucocorticoid concentrations alter telomere length in brain tissue cells is unclear. In addition to modulating the activity of the stress system, estrogen also influences telomere length. The objective of this study was to verify whether chronic exposure to glucocorticoids promotes changes in the telomere length of encephalic areas involved in the control of HPA axis activity and whether estrogen affects these changes. Wistar rats were ovariectomized and treated with estradiol cypionate [(50 or 100 μg/kg, subcutaneously)] or oil and 20 mg/kg corticosterone or vehicle (isotonic saline with 2% Tween 80, subcutaneously) for 28 days. On the day after the end of the hormonal treatment, the animals were euthanized for collection of blood, brain and pituitary gland samples. Estrogen modulated the activity of the HPA axis. CRH, AVP and POMC mRNA levels were reduced by estrogen. At least in doses and treatment time used, there was no correlation between effects of exposure to glucocorticoids and estrogen on telomere length in the brain areas of female rats. However, estrogen treatment reduced the telomere length in the central amygdala and dorsal hippocampus, but not in the PVN, indicating a variation of reaction of telomeres for estrogen in different brain areas.
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19
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Karakaya E, Akdur A, Ayvazoğlu Soy E, Moray G, Haberal M. Success Rate of Grafts With Multiple Renal Vessels in 3136 Kidney Transplants. EXP CLIN TRANSPLANT 2020; 19:14-19. [PMID: 32967599 DOI: 10.6002/ect.2020.0339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
OBJECTIVES Multiple renal vessels are often detected in living and deceased organ donors. In the past, transplant with multiple renal vessel grafts has been a contraindication because of high vascular and urological complication rates. However, improvements in vascular reconstruction and anastomosis techniques have allowed graft function to be maintained for many years. Here, we retrospectively evaluated transplant of multiple renal vessel grafts and graft survival and postoperative vascular and urological complications. MATERIALS AND METHODS From November 1975 to July 2020, there were 3136 renal transplants (716 deceased donors, 2420 living donors) performed in our center. There were 2167 living donors and 643 deceased donors with single renal vessel grafts and 253 living donors and 73 deceased donors with multiple renal vessel grafts. For anastomoses, external iliac, internal iliac, common iliac, and inferior epigastric arteries and external iliac veins were used. Cold ischemia time, anastomosis time, postoperative vascular and urological complications, acute tubular necrosis, creatinine clearance, serum creatinine levels, graft rejection episodes, and graft and patient survival rates were evaluated. RESULTS With regard to creatinine clearance, cold ischemia and anastomosis time, acute tubular necrosis, rejection episodes, and 1-, 2-, and 5-year posttransplant serum creatinine levels, there were no significant differences between the groups. Graft survival rates in the single renal vessel group were 92.9% at 1 year posttransplant and 78.3% at 5 years posttransplant; rates in the multiple renal vessel group were 93.1% at 1 year and 79.7% at 5 years. The corresponding patient survival rates were 95.5% (1 year) and 92.9% (5 years) for the single renal vessel group and 96.9% (1 year) and 87.2% (5 years) for the multiple renal vessel group. CONCLUSIONS Improved anastomosis and recon struction techniques have allowed the safe transplant of multiple renal vessel grafts that may remain functional for many years.
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Affiliation(s)
- Emre Karakaya
- From the Department of General Surgery, Baskent University, Ankara, Turkey
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20
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Shubin CB, Greider CW. The role of Rif1 in telomere length regulation is separable from its role in origin firing. eLife 2020; 9:58066. [PMID: 32597753 PMCID: PMC7371424 DOI: 10.7554/elife.58066] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 06/29/2020] [Indexed: 12/25/2022] Open
Abstract
To examine the established link between DNA replication and telomere length, we tested whether firing of telomeric origins would cause telomere lengthening. We found that RIF1 mutants that block Protein Phosphatase 1 (PP1) binding activated telomeric origins but did not elongate telomeres. In a second approach, we found overexpression of ∆N-Dbf4 and Cdc7 increased DDK activity and activated telomeric origins, yet telomere length was unchanged. We tested a third mechanism to activate origins using the sld3-A mcm5-bob1 mutant that de-regulates the pre-replication complex, and again saw no change in telomere length. Finally, we tested whether mutations in RIF1 that cause telomere elongation would affect origin firing. We found that neither rif1-∆1322 nor rif1HOOK affected firing of telomeric origins. We conclude that telomeric origin firing does not cause telomere elongation, and the role of Rif1 in regulating origin firing is separable from its role in regulating telomere length.
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Affiliation(s)
- Calla B Shubin
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, United States.,Biochemistry, Cellular and Molecular Biology Graduate Program, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Carol W Greider
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, United States
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21
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Rollings N, Waye HL, Krohmer RW, Uhrig EJ, Mason RT, Olsson M, Whittington CM, Friesen CR. Sperm telomere length correlates with blood telomeres and body size in red‐sided garter snakes,
Thamnophis sirtalis parietalis. J Zool (1987) 2020. [DOI: 10.1111/jzo.12789] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- N. Rollings
- School of Life and Environmental Sciences University of Sydney Sydney NSW Australia
| | - H. L. Waye
- Division of Science and Mathematics University of Minnesota Morris Morris MN USA
| | - R. W Krohmer
- Department of Biological Sciences Saint Xavier University Chicago IL USA
| | - E. J. Uhrig
- Department of Integrative Biology Oregon State University Corvallis OR USA
| | - R. T. Mason
- Department of Integrative Biology Oregon State University Corvallis OR USA
| | - M. Olsson
- Department of Biological & Environmental Sciences University of Gothenburg Gothenburg Sweden
- School of Earth, Atmospheric and Life Sciences University of Wollongong Wollongong NSW Australia
| | - C. M. Whittington
- School of Life and Environmental Sciences University of Sydney Sydney NSW Australia
| | - C. R. Friesen
- School of Earth, Atmospheric and Life Sciences University of Wollongong Wollongong NSW Australia
- Illawarra Health and Medical Research Institute (IHMRI)University of Wollongong Wollongong NSW Australia
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22
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Kordowitzki P, Hamdi M, Derevyanko A, Rizos D, Blasco M. The effect of rapamycin on bovine oocyte maturation success and metaphase telomere length maintenance. Aging (Albany NY) 2020; 12:7576-7584. [PMID: 32339158 PMCID: PMC7202508 DOI: 10.18632/aging.103126] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 03/30/2020] [Indexed: 12/18/2022]
Abstract
Maternal aging-associated reduction of oocyte viability is a common feature in mammals, but more research is needed to counteract this process. In women, the first aging phenotype appears with a decline in reproductive function, and the follicle number gradually decreases from menarche to menopause. Cows can be used as a model of early human embryonic development and reproductive aging because both species share a very high degree of similarity during follicle selection, cleavage, and blastocyst formation. Recently, it has been proposed that the main driver of aging is the mammalian target of rapamycin (mTOR) signaling rather than reactive oxygen species. Based on these observations, the study aimed to investigate for the first time the possible role of rapamycin on oocyte maturation, embryonic development, and telomere length in the bovine species, as a target for future strategies for female infertility caused by advanced maternal age. The 1nm rapamycin in vitro treatment showed the best results for maturation rates (95.21±4.18%) of oocytes and was considered for further experiments. In conclusion, rapamycin influenced maturation rates of oocytes in a concentration-dependent manner. Our results also suggest a possible link between mTOR, telomere maintenance, and bovine blastocyst formation.
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Affiliation(s)
- Pawel Kordowitzki
- Institute of Animal Reproduction and Food Research of Polish Academy of Sciences, Olsztyn, Poland.,Institute of Veterinary Medicine, Nicolaus Copernicus University, Torun, Poland
| | - Meriem Hamdi
- Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Department of Animal Reproduction, Madrid, Spain
| | - Aksinya Derevyanko
- Telomeres and Telomerase Group, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Dimitrios Rizos
- Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Department of Animal Reproduction, Madrid, Spain
| | - Maria Blasco
- Telomeres and Telomerase Group, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
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23
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Abstract
Conventional approaches to identify a telomere motif in a new genome are laborious and time-intensive. An efficient new methodology based on next-generation sequencing (NGS), de novo sequence repeat finder (SERF) and fluorescence in situ hybridization (FISH) is presented. Unlike existing heuristic approaches, SERF utilizes an exhaustive analysis of raw NGS reads or assembled contigs for rapid de novo detection of conserved tandem repeats representing telomere motifs. SERF was validated using the NGS data from Ipheion uniflorum and Allium cepa with known telomere motifs. The analysis program was then used on NGS data to investigate the telomere motifs in several additional plant species and together with FISH proved to be an efficient approach to identify as yet unknown telomere motifs.
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24
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Rollings N, Friesen CR, Whittington CM, Johansson R, Shine R, Olsson M. Sex- And tissue-specific differences in telomere length in a reptile. Ecol Evol 2019; 9:6211-6219. [PMID: 31236215 PMCID: PMC6580261 DOI: 10.1002/ece3.5164] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 03/19/2019] [Accepted: 03/22/2019] [Indexed: 12/25/2022] Open
Abstract
The usage of telomere length (TL) in blood as a proxy for the TL of other tissues relies on the assumption that telomere dynamics across all tissues are similar. However, telomere attrition can be caused by reactive oxygen species (ROS) which may vary with metabolic rate, which itself varies across organs depending upon the life history strategy of an organism. Thus, we chose to measure the telomeres of various cell types in juvenile painted dragon lizards, Ctenophorus pictus, given their unusual life history strategy. Individuals typically only experience a single mating season. We measured the TL of male and female dragons using qPCR and observed that TL varied with tissue type and sex. Telomeres of blood cells were longer than those of liver, heart, brain, and spleen, and females had longer telomeres than males. Brain telomeres in males were approximately half the length of those in females. Telomeric attrition in the male brain may be due to the need for rapid learning of reproductive tactics (territory patrol and defense, mate-finding). Significant correlations between the TL of tissue types suggest that blood TL may be a useful proxy for the TL of other tissues. Our comparison of organ-specific telomere dynamics, the first in a reptile, suggests that the usage of blood TL as a proxy requires careful consideration of the life history strategy of the organism.
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Affiliation(s)
- Nicky Rollings
- School of Life and Environmental SciencesUniversity of SydneySydneyNew South WalesAustralia
| | | | - Camilla M. Whittington
- School of Life and Environmental SciencesUniversity of SydneySydneyNew South WalesAustralia
- Sydney School of Veterinary ScienceUniversity of SydneySydneyNew South WalesAustralia
| | - Rasmus Johansson
- Department of Biological & Environmental SciencesUniversity of GothenburgGothenburgSweden
| | - Richard Shine
- School of Life and Environmental SciencesUniversity of SydneySydneyNew South WalesAustralia
- Department of Biological SciencesMacquarie UniversitySydneyNew South WalesAustralia
| | - Mats Olsson
- Department of Biological & Environmental SciencesUniversity of GothenburgGothenburgSweden
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Pharmacological inhibition of guanosine triphosphate cyclohydrolase1 elevates tyrosine phosphorylation of caveolin1 and cellular senescence. Eur J Pharmacol 2019; 848:1-10. [PMID: 30690003 DOI: 10.1016/j.ejphar.2019.01.036] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 01/15/2019] [Accepted: 01/18/2019] [Indexed: 01/02/2023]
Abstract
The role of 2,4-diamino-6-hydroxypyrimidine (DAHP), on cellular-senescence remains unclear as differential effects of DAHP have been reported in cardiovascular and cerebrovascular systems. We investigated the effect of pharmacologically-induced guanosine-triphosphate-cyclohydrolase1 (GTPCH1)-inhibition, through DAHP, on cellular-senescence in experimentally-induced diabetic and non-diabetic Wistar rats. Cellular-senescence was evaluated through senescence-associated events, namely, cell-cycle-arrest of peripheral blood mononuclear cells (PBMNCs); myocardial DNA fragmentation, total antioxidant capacity (TAC), telomerase-activity, nicotinamide adenine dinucleotide (NAD+)-content and tyrosine14-phosphorylation of caveolin1 (pY14) in similarly-aged, pubertal Wistar rats with streptozotocin (STZ) and/or DAHP. Oxidative stress (OS) indices such as myocardial biopterin concentrations (tetrahydrobiopterin-BH4 and dihydrobiopterin-BH2) and plasma total nitrite and nitrate (NOx) were determined. DAHP, per se, exhibited distinct senescence; in addition, in STZ+DAHP (the cardiomyopathy model), there was a marked accumulation of cells in G0G1 phase, as evidenced through flow-cytometry analysis, as-well-as fragmented DNA, than the respective controls suggesting the DAHP-mediated onset of senescence in circulating cells and the myocardium, with or without STZ. Concentrations of BH4 and BH2, and NOx were impaired in STZ and/or DAHP, indicating elevated OS in the treatment groups. In the independent treatment groups or the combination treatment, typical senescence indicators including myocardial telomerase-activity, NAD+-content and TAC were significantly reduced, while there was a marked elevation in the concentrations of pY14 as compared to the respective controls, reinforcing the occurrence of senescence in PBMNCs and the myocardium. We postulate that DAHP promotes early onset of cellular-senescence, potentially through OS-mediated cellular events in diabetic or non-diabetic models.
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26
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Insights into Endothelial Progenitor Cells: Origin, Classification, Potentials, and Prospects. Stem Cells Int 2018; 2018:9847015. [PMID: 30581475 PMCID: PMC6276490 DOI: 10.1155/2018/9847015] [Citation(s) in RCA: 128] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 08/27/2018] [Accepted: 09/18/2018] [Indexed: 02/07/2023] Open
Abstract
With the discovery of endothelial progenitor cells (EPCs) in the late 1990s, a paradigm shift in the concept of neoangiogenesis occurred. The identification of circulating EPCs in peripheral blood marked the beginning of a new era with enormous potential in the rapidly transforming regenerative field. Overwhelmed with the revelation, researchers across the globe focused on isolating, defining, and interpreting the role of EPCs in various physiological and pathological conditions. Consequently, controversies emerged regarding the isolation techniques and classification of EPCs. Nevertheless, the potential of using EPCs in tissue engineering as an angiogenic source has been extensively explored. Concomitantly, the impact of EPCs on various diseases, such as diabetes, cancer, and cardiovascular diseases, has been studied. Within the limitations of the current knowledge, this review attempts to delineate the concept of EPCs in a sequential manner from the speculative history to a definitive presence (origin, sources of EPCs, isolation, and identification) and significance of these EPCs. Additionally, this review is aimed at serving as a guide for investigators, identifying potential research gaps, and summarizing our current and future prospects regarding EPCs.
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Leung CW, Fung TT, McEvoy CT, Lin J, Epel ES. Diet Quality Indices and Leukocyte Telomere Length Among Healthy US Adults: Data From the National Health and Nutrition Examination Survey, 1999-2002. Am J Epidemiol 2018; 187:2192-2201. [PMID: 29912268 PMCID: PMC6166208 DOI: 10.1093/aje/kwy124] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 05/31/2018] [Accepted: 06/07/2018] [Indexed: 01/04/2023] Open
Abstract
Aging is the biggest risk factor for the development of chronic diseases. Telomere length may represent one important mechanism by which dietary intake influences risk of age-related diseases; however, it is unknown which diet pattern is most strongly related to telomere length. We compared the relationships between 4 evidence-based diet quality indices and leukocyte telomere length in a nationally representative sample of healthy adults, and the extent to which these associations differed between men and women. Data on 4,758 adults aged 20-65 years with no prior diagnosis of major chronic disease were obtained from the 1999-2002 cycles of the National Health and Nutrition Examination Survey. Diet was assessed using one 24-hour dietary recall. After adjustment for sociodemographic and health characteristics, comparison of the top and bottom quintiles showed that higher Healthy Eating Index 2010 scores (β = 0.065, 95% confidence interval (CI): 0.018, 0.112; P-trend = 0.007), Alternate Healthy Eating Index 2010 scores (β = 0.054, 95% CI: 0.010, 0.097; P-trend = 0.007), Mediterranean Diet scores (β = 0.058, 95% CI: 0.017, 0.098; P-trend = 0.008), and Dietary Approaches to Stop Hypertension (DASH) scores (β = 0.052, 95% CI: 0.014, 0.090; P-trend = 0.007) were each associated with longer telomere length in women. These results may provide insight into the complex associations between optimal nutrition and longevity. Further investigation is needed to understand why associations were not observed in men.
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Affiliation(s)
- Cindy W Leung
- Center for Health and Community, University of California, San Francisco, San Francisco, California
- Department of Nutritional Sciences, School of Public Health, University of Michigan, Ann Arbor, Michigan
| | - Teresa T Fung
- Department of Nutrition, School of Nursing and Health Sciences, Simmons College, Boston, Massachusetts
- Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
| | | | - Jue Lin
- Department of Biochemistry and Biophysics, School of Medicine, University of California, San Francisco, San Francisco, California
| | - Elissa S Epel
- Department of Psychiatry, School of Medicine, University of California, San Francisco, San Francisco, California
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28
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Cheng SB, Davis S, Sharma S. Maternal-fetal cross talk through cell-free fetal DNA, telomere shortening, microchimerism, and inflammation. Am J Reprod Immunol 2018; 79:e12851. [PMID: 29577468 PMCID: PMC5908740 DOI: 10.1111/aji.12851] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Accepted: 02/22/2018] [Indexed: 12/11/2022] Open
Abstract
There exists a strong correlation between unscheduled inflammation at the maternal-fetal interface and the continuum of pregnancy complications. In normal pregnancy, immunological tolerance is established to protect the semi-allogeneic fetus. There has been extensive research on how the immunity, endovascular trophoblast migration, and hormonal nexus are orchestrated during pregnancy at the maternal-fetal interface to program a normal pregnancy outcome. It is not clear what contributes to the plasticity of uterine immune tolerance, fetal survial, and long-term post-partum health of the mother and the offspring. Old and new concepts have reemerged and emerged that include cell-free fetal DNA (cffDNA), telomere shortening, microchimerism involving bidirectional migration of maternal and fetal cells, and pregnancy as a stress factor. The question is how these pathways converge in a gestational age-dependent manner to contribute to the health of the mother and the offspring later in life and respond to an array of inflammatory challenges. In this Review, we provide pertinent discussion on maternal-fetal cross talk through cffDNA, telomere shortening, and microchimerism in the context of inflammatory and anti-inflammatory settings, particularly how these pathways lead to normal and adverse pregnancy outcomes.
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Affiliation(s)
- Shi-Bin Cheng
- Department of Pediatrics, Women and Infants’ Hospital of Rhode Island, Warren Alpert Medical School of Brown University, Providence, RI, USA
| | - Sarah Davis
- Department of Obstetrics and Gynecology, Women and Infants’ Hospital of Rhode Island, Warren Alpert Medical School of Brown University, Providence, RI, USA
| | - Surendra Sharma
- Department of Pediatrics, Women and Infants’ Hospital of Rhode Island, Warren Alpert Medical School of Brown University, Providence, RI, USA
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29
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Sultana Z, Maiti K, Dedman L, Smith R. Is there a role for placental senescence in the genesis of obstetric complications and fetal growth restriction? Am J Obstet Gynecol 2018; 218:S762-S773. [PMID: 29275823 DOI: 10.1016/j.ajog.2017.11.567] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 10/23/2017] [Accepted: 11/08/2017] [Indexed: 12/11/2022]
Abstract
The placenta ages as pregnancy advances, yet its continued function is required for a successful pregnancy outcome. Placental aging is a physiological phenomenon; however, there are some placentas that show signs of aging earlier than others. Premature placental senescence and aging are implicated in a number of adverse pregnancy outcomes, including fetal growth restriction, preeclampsia, spontaneous preterm birth, and intrauterine fetal death. Here we discuss cellular senescence, a state of terminal proliferation arrest, and how senescence is regulated. We also explore the role of physiological placental senescence and how aberrant placental senescence alters placental function, contributing to the pathophysiology of fetal growth restriction, preeclampsia, spontaneous preterm labor/birth, and unexplained fetal death.
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30
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Wang S, Pike AM, Lee SS, Strong MA, Connelly CJ, Greider CW. BRD4 inhibitors block telomere elongation. Nucleic Acids Res 2017; 45:8403-8410. [PMID: 28854735 PMCID: PMC5737673 DOI: 10.1093/nar/gkx561] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 06/22/2017] [Indexed: 12/25/2022] Open
Abstract
Cancer cells maintain telomere length equilibrium to avoid senescence and apoptosis induced by short telomeres, which trigger the DNA damage response. Limiting the potential for telomere maintenance in cancer cells has been long been proposed as a therapeutic target. Using an unbiased shRNA screen targeting known kinases, we identified bromodomain-containing protein 4 (BRD4) as a telomere length regulator. Four independent BRD4 inhibitors blocked telomere elongation, in a dose-dependent manner, in mouse cells overexpressing telomerase. Long-term treatment with BRD4 inhibitors caused telomere shortening in both mouse and human cells, suggesting BRD4 plays a role in telomere maintenance in vivo. Telomerase enzymatic activity was not directly affected by BRD4 inhibition. BRD4 is in clinical trials for a number of cancers, but its effects on telomere maintenance have not been previously investigated.
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Affiliation(s)
- Steven Wang
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.,Cellular and Molecular Medicine Graduate Program, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Alexandra M Pike
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.,Cellular and Molecular Medicine Graduate Program, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Stella S Lee
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Margaret A Strong
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Carla J Connelly
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Carol W Greider
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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31
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Transcription regulation of CDKN1A (p21/CIP1/WAF1) by TRF2 is epigenetically controlled through the REST repressor complex. Sci Rep 2017; 7:11541. [PMID: 28912501 PMCID: PMC5599563 DOI: 10.1038/s41598-017-11177-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 07/20/2017] [Indexed: 12/13/2022] Open
Abstract
We observed extra-telomeric binding of the telomere repeat binding factor TRF2 within the promoter of the cyclin-dependent kinase CDKNIA (p21/CIP1/WAF1). This result in TRF2 induced transcription repression of p21. Interestingly, p21 repression was through engagement of the REST-coREST-LSD1-repressor complex and altered histone marks at the p21 promoter in a TRF2-dependent fashion. Furthermore, mutational analysis shows p21 repression requires interaction of TRF2 with a p21 promoter G-quadruplex. Physiologically, TRF2-mediated p21 repression attenuated drug-induced activation of cellular DNA damage response by evading G2/M arrest in cancer cells. Together these reveal for the first time role of TRF2 in REST- repressor complex mediated transcription repression.
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32
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Eastley N, Ottolini B, Garrido C, Shaw JA, McCulloch TA, Ashford RU, Royle NJ. Telomere maintenance in soft tissue sarcomas. J Clin Pathol 2017; 70:371-377. [PMID: 28183782 PMCID: PMC5484030 DOI: 10.1136/jclinpath-2016-204151] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Accepted: 12/15/2016] [Indexed: 01/27/2023]
Abstract
Soft tissue sarcomas (STS) are a diverse group of heterogeneous malignant tumours derived from mesenchymal tissues. Over 50 different STS subtypes are recognised by WHO, which show a wide range of different biological behaviours and prognoses. At present, clinicians managing this complex group of tumours face several challenges. This is reflected by the relatively poor outcome of patients with STSs compared with many other solid malignant tumours. These include difficulties securing accurate diagnoses, a lack of effective systemic treatments and absence of any sensitive circulating biomarkers to monitor patients throughout their treatment and follow-up. In order to progress STS's cells must evade the usual cellular proliferative checkpoints, and then activate a telomere maintenance mechanism in order to achieve replicative immortality. The purpose of this review is to provide an overview of STS genetics focusing particularly on these mechanisms. We will also highlight some of the key barriers to improving outcome for patients with STS, and hypothesise how a better understanding of these genetic characteristics may impact on future STS management.
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Affiliation(s)
| | - Barbara Ottolini
- Department of Cancer Studies, University of Leicester, Leicester, UK
| | - Carmen Garrido
- Department of Genetics, University of Leicester, Leicester, UK
| | - Jacqueline A Shaw
- Department of Cancer Studies, University of Leicester, Leicester, UK
| | | | | | - Nicola J Royle
- Department of Genetics, University of Leicester, Leicester, UK
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Affiliation(s)
- Christian Bär
- From the Institute of Molecular and Translational Therapeutic Strategies, Hannover Medical School, Germany
| | - Thomas Thum
- From the Institute of Molecular and Translational Therapeutic Strategies, Hannover Medical School, Germany
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Sultana Z, Maiti K, Aitken J, Morris J, Dedman L, Smith R. Oxidative stress, placental ageing-related pathologies and adverse pregnancy outcomes. Am J Reprod Immunol 2017; 77. [PMID: 28240397 DOI: 10.1111/aji.12653] [Citation(s) in RCA: 161] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 01/20/2017] [Indexed: 12/22/2022] Open
Abstract
Oxidative stress (OS), an imbalance between free radical generation and antioxidant defence, is recognized as a key factor in the pathogenesis of adverse pregnancy outcomes. Although OS is a common future of normal pregnancy, persistent, overwhelming OS leads to consumption and decline of antioxidants, affecting placental antioxidant capacity and reducing systems. The accumulation of OS causes damage to lipids, proteins and DNA in the placental tissue that induces a form of accelerated ageing. Premature ageing of the placenta is associated with placental insufficiency that prevents the organ meeting the needs of the foetus, and as a consequence, the viability of the foetus is compromised. This review summarizes the literature regarding the role of OS and premature placental ageing in the pathophysiology of pregnancy complications.
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Affiliation(s)
- Zakia Sultana
- Mothers and Babies Research Centre, Hunter Medical Research Institute, Newcastle, NSW, Australia.,Faculty of Health and Medicine, School of Medicine and Public Health, University of Newcastle, Newcastle, NSW, Australia.,Priority Research Centre for Reproductive Science, University of Newcastle, Newcastle, NSW, Australia
| | - Kaushik Maiti
- Mothers and Babies Research Centre, Hunter Medical Research Institute, Newcastle, NSW, Australia.,Faculty of Health and Medicine, School of Medicine and Public Health, University of Newcastle, Newcastle, NSW, Australia.,Priority Research Centre for Reproductive Science, University of Newcastle, Newcastle, NSW, Australia
| | - John Aitken
- Priority Research Centre for Reproductive Science, University of Newcastle, Newcastle, NSW, Australia
| | - Jonathan Morris
- Kolling Institute, Royal North Shore Hospital, University of Sydney, Sydney, NSW, Australia
| | - Lee Dedman
- Faculty of Science and Information Technology, School of Design, Communication and Information Technology, University of Newcastle, Newcastle, NSW, Australia
| | - Roger Smith
- Mothers and Babies Research Centre, Hunter Medical Research Institute, Newcastle, NSW, Australia.,Faculty of Health and Medicine, School of Medicine and Public Health, University of Newcastle, Newcastle, NSW, Australia.,Priority Research Centre for Reproductive Science, University of Newcastle, Newcastle, NSW, Australia
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35
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Hatakeyama H, Yamazaki H, Nakamura KI, Izumiyama-Shimomura N, Aida J, Suzuki H, Tsuchida S, Matsuura M, Takubo K, Ishikawa N. Telomere attrition and restoration in the normal teleost Oryzias latipes are linked to growth rate and telomerase activity at each life stage. Aging (Albany NY) 2016; 8:62-76. [PMID: 26789258 PMCID: PMC4761714 DOI: 10.18632/aging.100873] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Telomere shortening occurs when cells divide, both in vitro and in vivo. On the other hand, telomerase is able to maintain telomere length in cells by adding TTAGGG repeats to the ends of telomeres. However, the interrelationships existing among telomere length, telomerase activity and growth in vertebrates remain to be clarified. In the present study we measured telomere length (terminal restriction fragment length), telomerase activity and body growth of Oryzias latipes from the embryo stage until senescence. During the rapid growth stage (age 0–7 months), telomeres shortened in parallel with decreasing telomerase activity. Then, during adolescence (age 7 months – 1 year), telomeres lengthened quickly as growth slowed and telomerase activity increased. In the adult stage (age 1–4 years) characterized by little growth, telomerase activity decreased gradually and telomeres shortened. Our data indicate that telomere attrition and restoration are linked to growth and telomerase activity, and suggest that critical loss of telomere homeostasis is associated with mortality in this animal.
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Affiliation(s)
- Hitoshi Hatakeyama
- Department of Comprehensive Education in Veterinary Medicine, Nippon Veterinary and Life Science University, Tokyo 180-8602, Japan.,Research Team for Geriatric Diseases, Tokyo Metropolitan Institute of Gerontology, Tokyo 173-0015, Japan
| | - Hiromi Yamazaki
- Department of Comprehensive Education in Veterinary Medicine, Nippon Veterinary and Life Science University, Tokyo 180-8602, Japan
| | - Ken-Ichi Nakamura
- Research Team for Geriatric Diseases, Tokyo Metropolitan Institute of Gerontology, Tokyo 173-0015, Japan
| | | | - Junko Aida
- Research Team for Geriatric Diseases, Tokyo Metropolitan Institute of Gerontology, Tokyo 173-0015, Japan
| | - Hiroetsu Suzuki
- Department of Basic Veterinary Medicine, Nippon Veterinary and Life Science University, Tokyo 180-8602, Japan
| | - Shuichi Tsuchida
- Department of Comprehensive Education in Veterinary Medicine, Nippon Veterinary and Life Science University, Tokyo 180-8602, Japan
| | - Masaaki Matsuura
- Bioinformatics Group, Genome Center, and Division of Cancer Genomics, Cancer Institute, Japanese Foundation for Cancer Research, Tokyo 135-8550, Japan
| | - Kaiyo Takubo
- Research Team for Geriatric Diseases, Tokyo Metropolitan Institute of Gerontology, Tokyo 173-0015, Japan
| | - Naoshi Ishikawa
- Research Team for Geriatric Diseases, Tokyo Metropolitan Institute of Gerontology, Tokyo 173-0015, Japan
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Abstract
INTRODUCTION Telomerase is a ribonucleoprotein that catalyses the addition of telomeric repeat sequences (having the sequence 5'-TTAGGG-3' in humans) to the ends of chromosomes. Telomerase activity is detected in most types of human tumours, but it is almost undetectable in normal somatic cells. Therefore, telomerase is a promising therapeutic target. To date, the known inhibitors of telomerase include nucleoside analogues, oligonucleotides and G-quadruplex stabilizers. This review highlights recent advances in our understanding of telomerase inhibitors, the relationships between telomerase inhibitors, cancer, and fields such as inflammation. AREAS COVERED This review summarizes new patents published on telomerase inhibitors from 2010 to 2015. EXPERT OPINION The review provides a brief account of the background, development, and on-going issues involving telomerase inhibitors. In particular, this review emphasizes imetelstat (GRN163L) and some typical G-quadruplex stabilizers that participate in telomerase inhibition. Overall, the research scope of antineoplastic is becoming broader and telomerase inhibitors have been shown to be a promising therapeutic target. Therefore, novel antineoplastic agents with greater activity and higher specificity must be developed.
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Affiliation(s)
- Ruo-Jun Man
- a State Key Laboratory of Pharmaceutical Biotechnology , Nanjing University , Nanjing , People's Republic of China.,b Preparatory College Education , Guangxi University for Nationalities , Nanning , People's Republic of China
| | - Long-Wang Chen
- a State Key Laboratory of Pharmaceutical Biotechnology , Nanjing University , Nanjing , People's Republic of China
| | - Hai-Liang Zhu
- a State Key Laboratory of Pharmaceutical Biotechnology , Nanjing University , Nanjing , People's Republic of China
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Biron-Shental T, Sadeh-Mestechkin D, Amiel A. Telomere homeostasis in IUGR placentas - A review. Placenta 2016; 39:21-3. [PMID: 26992670 DOI: 10.1016/j.placenta.2015.11.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 11/13/2015] [Accepted: 11/18/2015] [Indexed: 01/29/2023]
Abstract
Telomeres are nucleoprotein structures located at the termini of chromosomes. They are essential for chromosome stability. Telomeres become shorter due to mitotic cycles and environmental factors. When telomeres are shortened and therefore dysfunctional, cellular senescence occurs and organ dysfunction might develop. During pregnancy, fetal growth restriction secondary to placental insufficiency has been linked to impaired telomere homeostasis in which telomeres are shorter, telomerase is decreased, and compensatory mechanisms of telomere capture are enhanced. These characteristics, along with increased signs of senescence, indicate telomere dysfunction in trophoblasts from placentas affected by intrauterine growth restriction (IUGR). This review summarizes the information currently available regarding telomere homeostasis in trophoblasts from human pregnancies affected by IUGR. Improved understanding of placental physiology might help in the development of treatment options for fetuses with IUGR.
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Affiliation(s)
- Tal Biron-Shental
- Department of Maternal-Fetal Medicine, Meir Medical Center, Kfar Saba, Israel; Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
| | - Dana Sadeh-Mestechkin
- Department of Maternal-Fetal Medicine, Meir Medical Center, Kfar Saba, Israel; Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Aliza Amiel
- Department of Maternal-Fetal Medicine, Meir Medical Center, Kfar Saba, Israel; Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
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Shirgahi Talari F, Bagherzadeh K, Golestanian S, Jarstfer M, Amanlou M. Potent Human Telomerase Inhibitors: Molecular Dynamic Simulations, Multiple Pharmacophore-Based Virtual Screening, and Biochemical Assays. J Chem Inf Model 2015; 55:2596-610. [PMID: 26529120 DOI: 10.1021/acs.jcim.5b00336] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Telomere maintenance is a universal cancer hallmark, and small molecules that disrupt telomere maintenance generally have anticancer properties. Since the vast majority of cancer cells utilize telomerase activity for telomere maintenance, the enzyme has been considered as an anticancer drug target. Recently, rational design of telomerase inhibitors was made possible by the determination of high resolution structures of the catalytic telomerase subunit from a beetle and subsequent molecular modeling of the human telomerase complex. A hybrid strategy including docking, pharmacophore-based virtual screening, and molecular dynamics simulations (MDS) were used to identify new human telomerase inhibitors. Docking methodology was applied to investigate the ssDNA telomeric sequence and two well-known human telomerase inhibitors' (BIBR1532 and MST-312) modes of interactions with hTERT TEN domain. Subsequently molecular dynamic simulations were performed to monitor and compare hTERT TEN domain, TEN-ssDNA, TEN-BIBR1532, TEN-MST-312, and TEN-ssDNA-BIBR1532 behavior in a dynamic environment. Pharmacophore models were generated considering the inhibitors manner in the TEN domain anchor site. These exploratory studies identified several new potent inhibitors whose IC50 values were generated experimentally in a low micromolar range with the aid of biochemical assays, including both the direct telomerase and the telomeric repeat amplification protocol (TRAP) assays. The results suggest that the current models of human telomerase are useful templates for rational inhibitor design.
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Affiliation(s)
- Faezeh Shirgahi Talari
- Department of Medicinal Chemistry, Faculty of Pharmacy and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences , Tehran, 14155-6451, Iran.,Eshelman School of Pharmacy, Division of Chemical Biology and Medicinal Chemistry, University of North Carolina , Chapel Hill, North Carolina 27599, United States
| | - Kowsar Bagherzadeh
- Razi Drug Research Center, Iran University of Medical Sciences , Tehran, 1449614535, Iran
| | - Sahand Golestanian
- Department of Medicinal Chemistry, Faculty of Pharmacy and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences , Tehran, 14155-6451, Iran
| | - Michael Jarstfer
- Eshelman School of Pharmacy, Division of Chemical Biology and Medicinal Chemistry, University of North Carolina , Chapel Hill, North Carolina 27599, United States
| | - Massoud Amanlou
- Department of Medicinal Chemistry, Faculty of Pharmacy and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences , Tehran, 14155-6451, Iran
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39
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Affiliation(s)
- Mary Armanios
- From the Departments of Oncology (M.A.) and Molecular Biology and Genetics (C.W.G.) and the Sidney Kimmel Comprehensive Cancer Center (M.A., C.W.G.), Johns Hopkins University School of Medicine, Baltimore
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Wu S, Ge Y, Huang L, Liu H, Xue Y, Zhao Y. BRG1, the ATPase subunit of SWI/SNF chromatin remodeling complex, interacts with HDAC2 to modulate telomerase expression in human cancer cells. Cell Cycle 2015; 13:2869-78. [PMID: 25486475 DOI: 10.4161/15384101.2014.946834] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Telomerase is often upregulated during initiation and/or progression of human tumors, suggesting that repression of telomerase might inhibit cancer growth or progression. Here, we report that BRG1, the ATPase subunit of the SWI/SNF chromatin remodeling complex, is a general suppressor of hTERT transcription in human cancer cells. While overexpression of BRG1 inhibits hTERT transcription, depletion of BRG1 stimulates transcription of hTERT, leading to higher telomerase activity and longer telomeres. Chromatin-immunoprecipitation assays revealed that BRG1 binds to the transcription start site (TSS) of the hTERT promoter and forms a ternary complex with histone deacetylase 2 (HDAC2). BRG1 remodels chromatin structure to facilitate the action of HDAC2, leading to deacetylation of H3K9ac and H4ac at the TSS and suppression of hTERT transcription. On the other hand, β-catenin binds to the TSS and stimulates hTERT transcription. Thus, BRG1/HDAC2 and β-catenin constitute a manipulative apparatus at the TSS to play opposite but complementary roles in regulating hTERT expression. These results uncover a yin-yang mechanism in modulating hTERT transcription and provide explanation for limited transcription of hTERT in human cancer cells. BRG1/HDAC2 may have a potential as an anti-cancer therapeutic and/or for reactivating cellular proliferative capacity in the context of in vitro tissue engineering.
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Affiliation(s)
- Shu Wu
- a The School of Life Sciences ; Tsinghua University ; Beijing , PR China
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Garbe JC, Vrba L, Sputova K, Fuchs L, Novak P, Brothman AR, Jackson M, Chin K, LaBarge MA, Watts G, Futscher BW, Stampfer MR. Immortalization of normal human mammary epithelial cells in two steps by direct targeting of senescence barriers does not require gross genomic alterations. Cell Cycle 2015; 13:3423-35. [PMID: 25485586 PMCID: PMC4613853 DOI: 10.4161/15384101.2014.954456] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Telomerase reactivation and immortalization are critical for human carcinoma progression. However, little is known about the mechanisms controlling this crucial step, due in part to the paucity of experimentally tractable model systems that can examine human epithelial cell immortalization as it might occur in vivo. We achieved efficient non-clonal immortalization of normal human mammary epithelial cells (HMEC) by directly targeting the 2 main senescence barriers encountered by cultured HMEC. The stress-associated stasis barrier was bypassed using shRNA to p16INK4; replicative senescence due to critically shortened telomeres was bypassed in post-stasis HMEC by c-MYC transduction. Thus, 2 pathologically relevant oncogenic agents are sufficient to immortally transform normal HMEC. The resultant non-clonal immortalized lines exhibited normal karyotypes. Most human carcinomas contain genomically unstable cells, with widespread instability first observed in vivo in pre-malignant stages; in vitro, instability is seen as finite cells with critically shortened telomeres approach replicative senescence. Our results support our hypotheses that: (1) telomere-dysfunction induced genomic instability in pre-malignant finite cells may generate the errors required for telomerase reactivation and immortalization, as well as many additional “passenger” errors carried forward into resulting carcinomas; (2) genomic instability during cancer progression is needed to generate errors that overcome tumor suppressive barriers, but not required per se; bypassing the senescence barriers by direct targeting eliminated a need for genomic errors to generate immortalization. Achieving efficient HMEC immortalization, in the absence of “passenger” genomic errors, should facilitate examination of telomerase regulation during human carcinoma progression, and exploration of agents that could prevent immortalization.
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Key Words
- BaP, benzo(a)pyrene
- CT, cholera toxin
- DDR, DNA damage response
- DMR, differentially methylated regions
- HMEC, human mammary epithelial cells
- OIS, oncogene-induced senescence
- PD, population doublings
- RB, retinoblastoma protein
- TTS, transcription start site
- X, oxytocin
- c-Myc
- carcinogenesis
- genomic instability
- human mammary epithelial cells
- immortalization
- p, passage
- p16INK4a
- p16sh, shRNA to p16INK4A
- senescence
- telomerase
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Affiliation(s)
- James C Garbe
- a Life Sciences Division ; Lawrence Berkeley National Laboratory ; Berkeley , CA USA
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Dvořáčková M, Fojtová M, Fajkus J. Chromatin dynamics of plant telomeres and ribosomal genes. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 83:18-37. [PMID: 25752316 DOI: 10.1111/tpj.12822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 03/03/2015] [Accepted: 03/03/2015] [Indexed: 05/03/2023]
Abstract
Telomeres and genes encoding 45S ribosomal RNA (rDNA) are frequently located adjacent to each other on eukaryotic chromosomes. Although their primary roles are different, they show striking similarities with respect to their features and additional functions. Both genome domains have remarkably dynamic chromatin structures. Both are hypersensitive to dysfunctional histone chaperones, responding at the genomic and epigenomic levels. Both generate non-coding transcripts that, in addition to their epigenetic roles, may induce gross chromosomal rearrangements. Both give rise to chromosomal fragile sites, as their replication is intrinsically problematic. However, at the same time, both are essential for maintenance of genomic stability and integrity. Here we discuss the structural and functional inter-connectivity of telomeres and rDNA, with a focus on recent results obtained in plants.
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Affiliation(s)
- Martina Dvořáčková
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Kamenice 5, 62500, Brno, Czech Republic
- Faculty of Science, Masaryk University, Kamenice 5, 62500, Brno, Czech Republic
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 61265, Brno, Czech Republic
| | - Miloslava Fojtová
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Kamenice 5, 62500, Brno, Czech Republic
- Faculty of Science, Masaryk University, Kamenice 5, 62500, Brno, Czech Republic
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 61265, Brno, Czech Republic
| | - Jiří Fajkus
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Kamenice 5, 62500, Brno, Czech Republic
- Faculty of Science, Masaryk University, Kamenice 5, 62500, Brno, Czech Republic
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 61265, Brno, Czech Republic
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Buczkowicz P, Hawkins C. Pathology, Molecular Genetics, and Epigenetics of Diffuse Intrinsic Pontine Glioma. Front Oncol 2015; 5:147. [PMID: 26175967 PMCID: PMC4485076 DOI: 10.3389/fonc.2015.00147] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 06/16/2015] [Indexed: 11/13/2022] Open
Abstract
Diffuse intrinsic pontine glioma (DIPG) is a devastating pediatric brain cancer with no effective therapy. Histological similarity of DIPG to supratentorial high-grade astrocytomas of adults has led to assumptions that these entities possess similar underlying molecular properties and therefore similar therapeutic responses to standard therapies. The failure of all clinical trials in the last 30 years to improve DIPG patient outcome has suggested otherwise. Recent studies employing next-generation sequencing and microarray technologies have provided a breadth of evidence highlighting the unique molecular genetics and epigenetics of this cancer, distinguishing it from both adult and pediatric cerebral high-grade astrocytomas. This review describes the most common molecular genetic and epigenetic signatures of DIPG in the context of molecular subgroups and histopathological diagnosis, including this tumor entity's unique mutational landscape, copy number alterations, and structural variants, as well as epigenetic changes on the global DNA and histone levels. The increased knowledge of DIPG biology and histopathology has opened doors to new diagnostic and therapeutic avenues.
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Affiliation(s)
- Pawel Buczkowicz
- Division of Pathology, The Hospital for Sick Children , Toronto, ON , Canada ; The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children , Toronto, ON , Canada
| | - Cynthia Hawkins
- Division of Pathology, The Hospital for Sick Children , Toronto, ON , Canada ; The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children , Toronto, ON , Canada ; Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto , Toronto, ON , Canada
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Kalathiya U, Padariya M, Baginski M. Molecular Modeling and Evaluation of Novel Dibenzopyrrole Derivatives as Telomerase Inhibitors and Potential Drug for Cancer Therapy. IEEE/ACM TRANSACTIONS ON COMPUTATIONAL BIOLOGY AND BIOINFORMATICS 2014; 11:1196-1207. [PMID: 26357055 DOI: 10.1109/tcbb.2014.2326860] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
During previous years, many studies on synthesis, as well as on anti-tumor, anti-inflammatory and anti-bacterial activities of the pyrazole derivatives have been described. Certain pyrazole derivatives exhibit important pharmacological activities and have proved to be useful template in drug research. Considering importance of pyrazole template, in current work the series of novel inhibitors were designed by replacing central ring of acridine with pyrazole ring. These heterocyclic compounds were proposed as a new potential base for telomerase inhibitors. Obtained dibenzopyrrole structure was used as a novel scaffold structure and extension of inhibitors was done by different functional groups. Docking of newly designed compounds in the telomerase active site (telomerase catalytic subunit TERT) was carried out. All dibenzopyrrole derivatives were evaluated by three docking programs: CDOCKER, Ligandfit docking (Scoring Functions) and AutoDock. Compound C_9g, C_9k and C_9l performed best in comparison to all designed inhibitors during the docking in all methods and in interaction analysis. Introduction of pyrazole and extension of dibenzopyrrole in compounds confirm that such compound may act as potential telomerase inhibitors.
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Wong MS, Wright WE, Shay JW. Alternative splicing regulation of telomerase: a new paradigm? Trends Genet 2014; 30:430-8. [PMID: 25172021 DOI: 10.1016/j.tig.2014.07.006] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 07/30/2014] [Accepted: 07/31/2014] [Indexed: 01/01/2023]
Abstract
Alternative splicing affects approximately 95% of eukaryotic genes, greatly expanding the coding capacity of complex genomes. Although our understanding of alternative splicing has increased rapidly, current knowledge of splicing regulation has largely been derived from studies of highly expressed mRNAs. Telomerase is a key example of a protein that is alternatively spliced, but it is expressed at very low levels and although it is known that misregulation of telomerase splicing is a hallmark of nearly all cancers, the details of this process are unclear. Here we review work showing that hTERT expression is in part regulated by atypical alternative splicing, perhaps due to its exceptionally low expression level. We propose that these differential regulatory mechanisms may be widely applicable to other genes and may provide new opportunities for the development of cancer therapeutics.
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Affiliation(s)
- Mandy S Wong
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX 75390-9039, USA
| | - Woodring E Wright
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX 75390-9039, USA
| | - Jerry W Shay
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX 75390-9039, USA; Center for Excellence in Genomics Medicine Research, King Abdulaziz University, Jeddah, Saudi Arabia.
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Beta human papillomavirus E6 expression inhibits stabilization of p53 and increases tolerance of genomic instability. J Virol 2014; 88:6112-27. [PMID: 24648447 DOI: 10.1128/jvi.03808-13] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
UNLABELLED Infections with the beta genus of human papillomaviruses (β-HPVs) may contribute to the development of nonmelanoma skin cancers. However, β-HPV genomes are found at too low a copy number in tumors for the virus to be necessary for tumor maintenance. Instead, they are hypothesized to destabilize the host genome by allowing the persistence of mutations that can drive tumorigenesis independently of the viral genome. Supporting this premise is our previous finding that the expression of some β-HPV E6 proteins can attenuate p53 signaling in response to DNA damage. We show that β-HPV E6 proteins can prevent the stabilization of p53 in response to two types of genome-destabilizing events, aberrant mitosis and dysregulated centrosome duplication. The inability to stabilize p53 in response to these stimuli allows cells expressing HPV5, HPV8, or HPV38 E6 to remain proliferatively active, leading to further genome deterioration in a proportion of these cells. These phenotypes are lost by the introduction of a mutation into the p300 binding domain of HPV8 E6 or by the transfection of mutated p300 that is resistant to the degradation mediated by HPV5 or HPV8 E6. These findings expand the understanding of the role played by p300 in promoting the faithful resolution of mitotic figures as well as proper centrosome duplication. Finally, we describe a phenomenon by which binucleated cells are resolved via cytokinesis into two cells, each with one nucleus. These data support the hypothesis that β-HPV infections may promote tumorigenesis via genome destabilization. IMPORTANCE The work described in this report provides support for the hypothesis that β-HPV infections may contribute to nonmelanoma skin cancer by increasing the likelihood that tumorigenic mutations are introduced into the host cell's genome. We demonstrate that expression of the E6 proteins from some of these viruses increases the tolerance of two genome-destabilizing events, aberrant cell division and dysregulated centrosome duplication. Typically, these mutagenic occurrences elicit the stabilization of the tumor suppressor p53, which prevents further propagation of cells containing these errors. We show that the expression of β-HPV E6 restricts this stabilization of p53, leading not only to continued cellular proliferation but also to further accumulation of similar mutagenic events. Finally, in addition to supporting a role for β-HPV infections in certain skin cancers, we present studies with a mutated β-HPV E6 protein suggesting that the histone acetyltransferase p300 plays a role in promoting genome stability during replication.
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Ludlow AT, Spangenburg EE, Chin ER, Cheng WH, Roth SM. Telomeres shorten in response to oxidative stress in mouse skeletal muscle fibers. J Gerontol A Biol Sci Med Sci 2014; 69:821-30. [PMID: 24418792 DOI: 10.1093/gerona/glt211] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Aging phenotypes are dictated by myriad cellular changes including telomere shortening. In most tissues, telomere shortening is accelerated during replication if unrepaired oxidative damage to telomere sequences is present. However, the effect of reactive oxygen species exposure on skeletal muscle telomeres is unknown. We sought to determine if oxidative stress shortens telomeres in isolated adult rodent skeletal muscle fibers. Flexor digitorum brevis muscles were dissected from male mice (C57BL/6, long telomere and CAST/Ei, wild-derived, short telomere) and dissociated into single fibers. Fibers were cultured at an oxygen tension of 2%-5% for 5 days in control, hydrogen peroxide (oxidant), or a combination of N-acetylcysteine (antioxidant) and oxidant containing media. Telomere length, telomerase enzyme activity, and protein content of TRF1 and TRF2 were subsequently measured. In both strains, oxidative stress resulted in significant telomere shortening in isolated skeletal muscle fibers, likely by different mechanisms. Telomerase activity was not altered by oxidative stress treatment but was significantly different between strains, with greater telomerase activity in long-telomere-bearing C57BL/6 mice. These results provide important insights into mechanisms by which oxidative stress could shorten skeletal muscle telomeres.
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Affiliation(s)
| | | | - Eva R Chin
- Department of Kinesiology, School of Public Health and
| | - Wen-Hsing Cheng
- Department of Nutrition and Food Science, University of Maryland, College Park. Present address: Department of Food Science, Nutrition and Health Promotion, Mississippi State University
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Telomere reprogramming and maintenance in porcine iPS cells. PLoS One 2013; 8:e74202. [PMID: 24098638 PMCID: PMC3787036 DOI: 10.1371/journal.pone.0074202] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 07/29/2013] [Indexed: 01/12/2023] Open
Abstract
Telomere reprogramming and silencing of exogenous genes have been demonstrated in mouse and human induced pluripotent stem cells (iPS cells). Pigs have the potential to provide xenotransplant for humans, and to model and test human diseases. We investigated the telomere length and maintenance in porcine iPS cells generated and cultured under various conditions. Telomere lengths vary among different porcine iPS cell lines, some with telomere elongation and maintenance, and others telomere shortening. Porcine iPS cells with sufficient telomere length maintenance show the ability to differentiate in vivo by teratoma formation test. IPS cells with short or dysfunctional telomeres exhibit reduced ability to form teratomas. Moreover, insufficient telomerase and incomplete telomere reprogramming and/or maintenance link to sustained activation of exogenous genes in porcine iPS cells. In contrast, porcine iPS cells with reduced expression of exogenous genes or partial exogene silencing exhibit insufficient activation of endogenous pluripotent genes and telomerase genes, accompanied by telomere shortening with increasing passages. Moreover, telomere doublets, telomere sister chromatid exchanges and t-circles that presumably are involved in telomere lengthening by recombination also are found in porcine iPS cells. These data suggest that both telomerase-dependent and telomerase-independent mechanisms are involved in telomere reprogramming during induction and passages of porcine iPS cells, but these are insufficient, resulting in increased telomere damage and shortening, and chromosomal instability. Active exogenes might compensate for insufficient activation of endogenous genes and incomplete telomere reprogramming and maintenance of porcine iPS cells. Further understanding of telomere reprogramming and maintenance may help improve the quality of porcine iPS cells.
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Mitteldorf JJ. Telomere biology: Cancer firewall or aging clock? BIOCHEMISTRY (MOSCOW) 2013; 78:1054-60. [DOI: 10.1134/s0006297913090125] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Telomere shortening in Ph-negative chronic myeloproliferative neoplasms: A biological marker of polycythemia vera and myelofibrosis, regardless of hydroxycarbamide therapy. Exp Hematol 2013; 41:627-34. [DOI: 10.1016/j.exphem.2013.03.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2012] [Revised: 03/17/2013] [Accepted: 03/19/2013] [Indexed: 02/08/2023]
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