1
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Velayutham N, Calderon MU, Alfieri CM, Padula SL, van Leeuwen FN, Scheijen B, Yutzey KE. Btg1 and Btg2 regulate neonatal cardiomyocyte cell cycle arrest. J Mol Cell Cardiol 2023; 179:30-41. [PMID: 37062247 PMCID: PMC10192094 DOI: 10.1016/j.yjmcc.2023.03.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 03/21/2023] [Accepted: 03/29/2023] [Indexed: 04/18/2023]
Abstract
Rodent cardiomyocytes undergo mitotic arrest in the first postnatal week. Here, we investigate the role of transcriptional co-regulator Btg2 (B-cell translocation gene 2) and functionally-similar homolog Btg1 in postnatal cardiomyocyte cell cycling and maturation. Btg1 and Btg2 (Btg1/2) are expressed in neonatal C57BL/6 mouse left ventricles coincident with cardiomyocyte cell cycle arrest. Btg1/2 constitutive double knockout (DKO) mouse hearts exhibit increased pHH3+ mitotic cardiomyocytes compared to Wildtype at postnatal day (P)7, but not at P30. Similarly, neonatal AAV9-mediated Btg1/2 double knockdown (DKD) mouse hearts exhibit increased EdU+ mitotic cardiomyocytes compared to Scramble AAV9-shRNA controls at P7, but not at P14. In neonatal rat ventricular myocyte (NRVM) cultures, siRNA-mediated Btg1/2 single and double knockdown cohorts showed increased EdU+ cardiomyocytes compared to Scramble siRNA controls, without increase in binucleation or nuclear DNA content. RNAseq analyses of Btg1/2-depleted NRVMs support a role for Btg1/2 in inhibiting cell proliferation, and in modulating reactive oxygen species response pathways, implicated in neonatal cardiomyocyte cell cycle arrest. Together, these data identify Btg1 and Btg2 as novel contributing factors in mammalian cardiomyocyte cell cycle arrest after birth.
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Affiliation(s)
- Nivedhitha Velayutham
- Molecular and Developmental Biology Graduate Program, Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH, USA; The Heart Institute, Division of Molecular Cardiovascular Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Maria Uscategui Calderon
- Molecular and Developmental Biology Graduate Program, Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH, USA; The Heart Institute, Division of Molecular Cardiovascular Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Christina M Alfieri
- The Heart Institute, Division of Molecular Cardiovascular Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Stephanie L Padula
- The Heart Institute, Division of Molecular Cardiovascular Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | | | | | - Katherine E Yutzey
- Molecular and Developmental Biology Graduate Program, Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH, USA; The Heart Institute, Division of Molecular Cardiovascular Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA.
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2
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Hoffman MJ, Takizawa A, Jensen ES, Schilling R, Grzybowski M, Geurts AM, Dwinell MR. Btg2 mutation induces renal injury and impairs blood pressure control in female rats. Physiol Genomics 2022; 54:231-241. [PMID: 35503009 DOI: 10.1152/physiolgenomics.00167.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hypertension (HTN) is a complex disease influenced by heritable genetic elements and environmental interactions. Dietary salt is among the most influential modifiable factors contributing to increased blood pressure (BP). It is well established that men and women develop BP impairment in different patterns and a recent emphasis has been placed on identifying mechanisms leading to the differences observed between the sexes in HTN development. The current work reported here builds on an extensive genetic mapping experiment which sought to identify genetic determinants of salt sensitive (SS) HTN using the Dahl SS rat. BTG anti-proliferation factor 2 (Btg2) was previously identified by our group as a candidate gene contributing to SS HTN in female rats. In the current study, Btg2 was mutated using TALEN targeted gene disruption on the SSBN congenic rat background. The Btg2 mutated rats exhibited impaired BP and proteinuria responses to a high salt diet compared to wild type rats. Differences in body weight, mutant pup viability, skeletal morphology, and adult nephron density suggest a potential role for Btg2 in developmental signaling pathways. Subsequent cell cycle gene expression assessment provides several additional signaling pathways that Btg2 may function through during salt handling in the kidney. The expression analysis also identified several potential upstream targets that can be explored to further isolate therapeutic approaches for SS HTN.
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Affiliation(s)
- Matthew J Hoffman
- Genomic Sciences and Precision Medicine Center, Medical College of Wisconsin, Milwaukee, WI, United States.,Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Akiko Takizawa
- Genomic Sciences and Precision Medicine Center, Medical College of Wisconsin, Milwaukee, WI, United States.,Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Eric S Jensen
- Biomedical Research Center, Medical College of Wisconsin, Milwaukee, WI, United States.,Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Rebecca Schilling
- Genomic Sciences and Precision Medicine Center, Medical College of Wisconsin, Milwaukee, WI, United States.,Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Michael Grzybowski
- Genomic Sciences and Precision Medicine Center, Medical College of Wisconsin, Milwaukee, WI, United States.,Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Aron M Geurts
- Genomic Sciences and Precision Medicine Center, Medical College of Wisconsin, Milwaukee, WI, United States.,Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Melinda R Dwinell
- Genomic Sciences and Precision Medicine Center, Medical College of Wisconsin, Milwaukee, WI, United States.,Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, United States
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3
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Suzuki K, Shinohara M, Uno Y, Tashiro Y, Gheni G, Yamamoto M, Fukumori A, Shindo A, Mashimo T, Tomimoto H, Sato N. Deletion of B-cell translocation gene 2 (BTG2) alters the responses of glial cells in white matter to chronic cerebral hypoperfusion. J Neuroinflammation 2021; 18:86. [PMID: 33812385 PMCID: PMC8019185 DOI: 10.1186/s12974-021-02135-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Accepted: 03/19/2021] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Subcortical ischemic vascular dementia, one of the major subtypes of vascular dementia, is characterized by lacunar infarcts and white matter lesions caused by chronic cerebral hypoperfusion. In this study, we used a mouse model of bilateral common carotid artery stenosis (BCAS) to investigate the role of B-cell translocation gene 2 (BTG2), an antiproliferation gene, in the white matter glial response to chronic cerebral hypoperfusion. METHODS Btg2-/- mice and littermate wild-type control mice underwent BCAS or sham operation. Behavior phenotypes were assessed by open-field test and Morris water maze test. Brain tissues were analyzed for the degree of white matter lesions and glial changes. To further confirm the effects of Btg2 deletion on proliferation of glial cells in vitro, BrdU incorporation was investigated in mixed glial cells derived from wild-type and Btg2-/- mice. RESULTS Relative to wild-type mice with or without BCAS, BCAS-treated Btg2-/- mice exhibited elevated spontaneous locomotor activity and poorer spatial learning ability. Although the severities of white matter lesions did not significantly differ between wild-type and Btg2-/- mice after BCAS, the immunoreactivities of GFAP, a marker of astrocytes, and Mac2, a marker of activated microglia and macrophages, in the white matter of the optic tract were higher in BCAS-treated Btg2-/- mice than in BCAS-treated wild-type mice. The expression level of Gfap was also significantly elevated in BCAS-treated Btg2-/- mice. In vitro analysis showed that BrdU incorporation in mixed glial cells in response to inflammatory stimulation associated with cerebral hypoperfusion was higher in Btg2-/- mice than in wild-type mice. CONCLUSION BTG2 negatively regulates glial cell proliferation in response to cerebral hypoperfusion, resulting in behavioral changes.
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Affiliation(s)
- Kaoru Suzuki
- Department of Aging Neurobiology, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, 7-430, Morioka, Obu, Aichi, 474-8511, Japan
| | - Mitsuru Shinohara
- Department of Aging Neurobiology, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, 7-430, Morioka, Obu, Aichi, 474-8511, Japan
- Department of Aging Neurobiology, Graduate School of Medicine, Osaka University, 2-2, Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Yoshihiro Uno
- Institute of Experimental Animal Sciences, Osaka University Medical School, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Yoshitaka Tashiro
- Department of Aging Neurobiology, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, 7-430, Morioka, Obu, Aichi, 474-8511, Japan
| | - Ghupurjan Gheni
- Department of Aging Neurobiology, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, 7-430, Morioka, Obu, Aichi, 474-8511, Japan
| | - Miho Yamamoto
- Department of Aging Neurobiology, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, 7-430, Morioka, Obu, Aichi, 474-8511, Japan
| | - Akio Fukumori
- Department of Aging Neurobiology, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, 7-430, Morioka, Obu, Aichi, 474-8511, Japan
- Department of Aging Neurobiology, Graduate School of Medicine, Osaka University, 2-2, Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Akihiko Shindo
- Department of Neurology, Graduate School of Medicine, Mie University, 174, Edobashi 2-chome, Tsu, Mie, 514-8507, Japan
| | - Tomoji Mashimo
- Institute of Experimental Animal Sciences, Osaka University Medical School, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Hidekazu Tomimoto
- Department of Neurology, Graduate School of Medicine, Mie University, 174, Edobashi 2-chome, Tsu, Mie, 514-8507, Japan
| | - Naoyuki Sato
- Department of Aging Neurobiology, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, 7-430, Morioka, Obu, Aichi, 474-8511, Japan.
- Department of Aging Neurobiology, Graduate School of Medicine, Osaka University, 2-2, Yamadaoka, Suita, Osaka, 565-0871, Japan.
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4
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Goldstein JM, Valido A, Lewandowski JP, Walker RG, Mills MJ, Messemer KA, Besseling P, Lee KH, Wattrus SJ, Cho M, Lee RT, Wagers AJ. Variation in zygotic CRISPR/Cas9 gene editing outcomes generates novel reporter and deletion alleles at the Gdf11 locus. Sci Rep 2019; 9:18613. [PMID: 31819086 PMCID: PMC6901511 DOI: 10.1038/s41598-019-54766-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 11/19/2019] [Indexed: 01/20/2023] Open
Abstract
Recent advances in CRISPR/Cas gene editing technology have significantly expanded the possibilities and accelerated the pace of creating genetically engineered animal models. However, CRISPR/Cas-based strategies designed to precisely edit the genome can often yield unintended outcomes. Here, we report the use of zygotic CRISPR/Cas9 injections to generate a knock-in GFP reporter mouse at the Gdf11 locus. Phenotypic and genomic characterization of founder animals from these injections revealed a subset that contained the correct targeting event and exhibited GFP expression that, within the hematopoietic system, was restricted predominantly to lymphoid cells. Yet, in another subset of founder mice, we detected aberrant integration events at the target site that dramatically and inaccurately shifted hematopoietic GFP expression from the lymphoid to the myeloid lineage. Additionally, we recovered multiple Gdf11 deletion alleles that modified the C-terminus of the GDF11 protein. When bred to homozygosity, most of these alleles recapitulated skeletal phenotypes reported previously for Gdf11 knockout mice, suggesting that these represent null alleles. However, we also recovered one Gdf11 deletion allele that encodes a novel GDF11 variant protein ("GDF11-WE") predicted to contain two additional amino acids (tryptophan (W) and glutamic acid (E)) at the C-terminus of the mature ligand. Unlike the other Gdf11 deletion alleles recovered in this study, homozygosity for the Gdf11WE allele did not phenocopy Gdf11 knockout skeletal phenotypes. Further investigation using in vivo and in vitro approaches demonstrated that GDF11-WE retains substantial physiological function, indicating that GDF11 can tolerate at least some modifications of its C-terminus and providing unexpected insights into its biochemical activities. Altogether, our study confirms that one-step zygotic injections of CRISPR/Cas gene editing complexes provide a quick and powerful tool to generate gene-modified mouse models. Moreover, our findings underscore the critical importance of thorough characterization and validation of any modified alleles generated by CRISPR, as unintended on-target effects that fail to be detected by simple PCR screening can produce substantially altered phenotypic readouts.
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Affiliation(s)
- Jill M Goldstein
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, 02138, USA
- Harvard Stem Cell Institute, Cambridge, MA, 02138, USA
- Paul F. Glenn Center for the Biology of Aging, Harvard Medical School, Boston, MA, 02215, USA
| | - Austin Valido
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Jordan P Lewandowski
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, 02138, USA
- Harvard Stem Cell Institute, Cambridge, MA, 02138, USA
| | - Ryan G Walker
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, 02138, USA
- Harvard Stem Cell Institute, Cambridge, MA, 02138, USA
| | - Melanie J Mills
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, 02138, USA
- Harvard Stem Cell Institute, Cambridge, MA, 02138, USA
| | - Kathleen A Messemer
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, 02138, USA
- Harvard Stem Cell Institute, Cambridge, MA, 02138, USA
- Paul F. Glenn Center for the Biology of Aging, Harvard Medical School, Boston, MA, 02215, USA
| | - Paul Besseling
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, 02138, USA
- Harvard Stem Cell Institute, Cambridge, MA, 02138, USA
| | - Kyu Ha Lee
- Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA
| | - Samuel J Wattrus
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, 02138, USA
- Harvard Stem Cell Institute, Cambridge, MA, 02138, USA
| | - Miook Cho
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, 02138, USA
- Harvard Stem Cell Institute, Cambridge, MA, 02138, USA
- Paul F. Glenn Center for the Biology of Aging, Harvard Medical School, Boston, MA, 02215, USA
| | - Richard T Lee
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, 02138, USA
- Harvard Stem Cell Institute, Cambridge, MA, 02138, USA
| | - Amy J Wagers
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, 02138, USA.
- Harvard Stem Cell Institute, Cambridge, MA, 02138, USA.
- Paul F. Glenn Center for the Biology of Aging, Harvard Medical School, Boston, MA, 02215, USA.
- Section on Islet Cell and Regenerative Biology, Joslin Diabetes Center, Boston, MA, 02215, USA.
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5
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Grigelioniene G, Suzuki HI, Taylan F, Mirzamohammadi F, Borochowitz ZU, Ayturk UM, Tzur S, Horemuzova E, Lindstrand A, Weis MA, Grigelionis G, Hammarsjö A, Marsk E, Nordgren A, Nordenskjöld M, Eyre DR, Warman ML, Nishimura G, Sharp PA, Kobayashi T. Gain-of-function mutation of microRNA-140 in human skeletal dysplasia. Nat Med 2019; 25:583-590. [PMID: 30804514 PMCID: PMC6622181 DOI: 10.1038/s41591-019-0353-2] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 01/11/2019] [Indexed: 02/06/2023]
Abstract
MicroRNAs (miRNAs) are post-transcriptional regulators of gene expression. Heterozygous loss-of-function point mutations of miRNA genes are associated with several human congenital disorders1-5, but neomorphic (gain-of-new-function) mutations in miRNAs due to nucleotide substitutions have not been reported. Here we describe a neomorphic seed region mutation in the chondrocyte-specific, super-enhancer-associated MIR140 gene encoding microRNA-140 (miR-140) in a novel autosomal dominant human skeletal dysplasia. Mice with the corresponding single nucleotide substitution show skeletal abnormalities similar to those of the patients but distinct from those of miR-140-null mice6. This mutant miRNA gene yields abundant mutant miR-140-5p expression without miRNA-processing defects. In chondrocytes, the mutation causes widespread derepression of wild-type miR-140-5p targets and repression of mutant miR-140-5p targets, indicating that the mutation produces both loss-of-function and gain-of-function effects. Furthermore, the mutant miR-140-5p seed competes with the conserved RNA-binding protein Ybx1 for overlapping binding sites. This finding may explain the potent target repression and robust in vivo effect by this mutant miRNA even in the absence of evolutionary selection of miRNA-target RNA interactions, which contributes to the strong regulatory effects of conserved miRNAs7,8. Our study presents the first case of a pathogenic gain-of-function miRNA mutation and provides molecular insight into neomorphic actions of emerging and/or mutant miRNAs.
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Affiliation(s)
- Giedre Grigelioniene
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.,Department of Molecular Medicine and Surgery and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
| | - Hiroshi I Suzuki
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Fulya Taylan
- Department of Molecular Medicine and Surgery and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Fatemeh Mirzamohammadi
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Zvi U Borochowitz
- Rappaport Faculty of Medicine, Technion-Israeli Institute of Technology, Medical Genetics Clinics, Assuta Medical Center, Haifa, Israel
| | - Ugur M Ayturk
- Orthopaedic Research Labs, Department of Orthopaedic Surgery, Boston Children's Hospital, Boston, MA, USA
| | - Shay Tzur
- Laboratory of Molecular Medicine, Rambam Health Care Campus, Haifa, Israel.,Genomic Research Department, Emedgene Technologies, Tel Aviv, Israel
| | - Eva Horemuzova
- Department for Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden.,Pediatric Endocrinology Unit, Karolinska University Hospital, Stockholm, Sweden
| | - Anna Lindstrand
- Department of Molecular Medicine and Surgery and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
| | - Mary Ann Weis
- Department of Orthopedics and Sports Medicine, University of Washington, Seattle, WA, USA
| | - Gintautas Grigelionis
- Department of Molecular Medicine and Surgery and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Anna Hammarsjö
- Department of Molecular Medicine and Surgery and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
| | - Elin Marsk
- Department of Otorhinolaryngology, Karolinska University Hospital, Stockholm, Sweden
| | - Ann Nordgren
- Department of Molecular Medicine and Surgery and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
| | - Magnus Nordenskjöld
- Department of Molecular Medicine and Surgery and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
| | - David R Eyre
- Department of Orthopedics and Sports Medicine, University of Washington, Seattle, WA, USA
| | - Matthew L Warman
- Orthopaedic Research Labs, Department of Orthopaedic Surgery, Boston Children's Hospital, Boston, MA, USA
| | - Gen Nishimura
- Center for Intractable Diseases, Saitama Medical University Hospital, Saitama, Japan
| | - Phillip A Sharp
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA.,Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Tatsuya Kobayashi
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
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6
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Yuniati L, Scheijen B, van der Meer LT, van Leeuwen FN. Tumor suppressors BTG1 and BTG2: Beyond growth control. J Cell Physiol 2018; 234:5379-5389. [PMID: 30350856 PMCID: PMC6587536 DOI: 10.1002/jcp.27407] [Citation(s) in RCA: 135] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 08/22/2018] [Indexed: 01/21/2023]
Abstract
Since the identification of B‐cell translocation gene 1 (BTG1) and BTG2 as antiproliferation genes more than two decades ago, their protein products have been implicated in a variety of cellular processes including cell division, DNA repair, transcriptional regulation and messenger RNA stability. In addition to affecting differentiation during development and in the adult, BTG proteins play an important role in maintaining homeostasis under conditions of cellular stress. Genomic profiling of B‐cell leukemia and lymphoma has put BTG1 and BTG2 in the spotlight, since both genes are frequently deleted or mutated in these malignancies, pointing towards a role as tumor suppressors. Moreover, in solid tumors, reduced expression of BTG1 or BTG2 is often correlated with malignant cell behavior and poor treatment outcome. Recent studies have uncovered novel roles for BTG1 and BTG2 in genotoxic and integrated stress responses, as well as during hematopoiesis. This review summarizes what is currently known about the roles of BTG1 and BTG2 in these and other cellular processes. In addition, we will highlight the molecular mechanisms and biological consequences of BTG1 and BTG2 deregulation during cancer progression and elaborate on the potential clinical implications of these findings.
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Affiliation(s)
- Laurensia Yuniati
- Laboratory of Pediatric Oncology, Radboud Institute for Molecular Life Science, Radboud University Medical Center, Nijmegen, The Netherlands.,Hubrecht Institute-KNAW, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Blanca Scheijen
- Laboratory of Pediatric Oncology, Radboud Institute for Molecular Life Science, Radboud University Medical Center, Nijmegen, The Netherlands.,Department of Pathology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Laurens T van der Meer
- Laboratory of Pediatric Oncology, Radboud Institute for Molecular Life Science, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Frank N van Leeuwen
- Laboratory of Pediatric Oncology, Radboud Institute for Molecular Life Science, Radboud University Medical Center, Nijmegen, The Netherlands
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7
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Medina-Gomez C, Kemp JP, Trajanoska K, Luan J, Chesi A, Ahluwalia TS, Mook-Kanamori DO, Ham A, Hartwig FP, Evans DS, Joro R, Nedeljkovic I, Zheng HF, Zhu K, Atalay M, Liu CT, Nethander M, Broer L, Porleifsson G, Mullin BH, Handelman SK, Nalls MA, Jessen LE, Heppe DH, Richards JB, Wang C, Chawes B, Schraut KE, Amin N, Wareham N, Karasik D, Van der Velde N, Ikram MA, Zemel BS, Zhou Y, Carlsson CJ, Liu Y, McGuigan FE, Boer CG, Bønnelykke K, Ralston SH, Robbins JA, Walsh JP, Zillikens MC, Langenberg C, Li-Gao R, Williams FM, Harris TB, Akesson K, Jackson RD, Sigurdsson G, den Heijer M, van der Eerden BC, van de Peppel J, Spector TD, Pennell C, Horta BL, Felix JF, Zhao JH, Wilson SG, de Mutsert R, Bisgaard H, Styrkársdóttir U, Jaddoe VW, Orwoll E, Lakka TA, Scott R, Grant SF, Lorentzon M, van Duijn CM, Wilson JF, Stefansson K, Psaty BM, Kiel DP, Ohlsson C, Ntzani E, van Wijnen AJ, Forgetta V, Ghanbari M, Logan JG, Williams GR, Bassett JD, Croucher PI, Evangelou E, Uitterlinden AG, Ackert-Bicknell CL, Tobias JH, Evans DM, Rivadeneira F. Life-Course Genome-wide Association Study Meta-analysis of Total Body BMD and Assessment of Age-Specific Effects. Am J Hum Genet 2018; 102:88-102. [PMID: 29304378 DOI: 10.1016/j.ajhg.2017.12.005] [Citation(s) in RCA: 212] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 11/30/2017] [Indexed: 12/22/2022] Open
Abstract
Bone mineral density (BMD) assessed by DXA is used to evaluate bone health. In children, total body (TB) measurements are commonly used; in older individuals, BMD at the lumbar spine (LS) and femoral neck (FN) is used to diagnose osteoporosis. To date, genetic variants in more than 60 loci have been identified as associated with BMD. To investigate the genetic determinants of TB-BMD variation along the life course and test for age-specific effects, we performed a meta-analysis of 30 genome-wide association studies (GWASs) of TB-BMD including 66,628 individuals overall and divided across five age strata, each spanning 15 years. We identified variants associated with TB-BMD at 80 loci, of which 36 have not been previously identified; overall, they explain approximately 10% of the TB-BMD variance when combining all age groups and influence the risk of fracture. Pathway and enrichment analysis of the association signals showed clustering within gene sets implicated in the regulation of cell growth and SMAD proteins, overexpressed in the musculoskeletal system, and enriched in enhancer and promoter regions. These findings reveal TB-BMD as a relevant trait for genetic studies of osteoporosis, enabling the identification of variants and pathways influencing different bone compartments. Only variants in ESR1 and close proximity to RANKL showed a clear effect dependency on age. This most likely indicates that the majority of genetic variants identified influence BMD early in life and that their effect can be captured throughout the life course.
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8
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Potter EA, Dolgova EV, Proskurina AS, Efremov YR, Minkevich AM, Rozanov AS, Peltek SE, Nikolin VP, Popova NA, Seledtsov IA, Molodtsov VV, Zavyalov EL, Taranov OS, Baiborodin SI, Ostanin AA, Chernykh ER, Kolchanov NA, Bogachev SS. Gene expression profiling of tumor-initiating stem cells from mouse Krebs-2 carcinoma using a novel marker of poorly differentiated cells. Oncotarget 2017; 8:9425-9441. [PMID: 28031533 PMCID: PMC5354742 DOI: 10.18632/oncotarget.14116] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 12/15/2016] [Indexed: 12/18/2022] Open
Abstract
Using the ability of poorly differentiated cells to natively internalize fragments of extracellular double-stranded DNA as a marker, we isolated a tumorigenic subpopulation present in Krebs-2 ascites that demonstrated the features of tumor-inducing cancer stem cells. Having combined TAMRA-labeled DNA probe and the power of RNA-seq technology, we identified a set of 168 genes specifically expressed in TAMRA-positive cells (tumor-initiating stem cells), these genes remaining silent in TAMRA-negative cancer cells. TAMRA+ cells displayed gene expression signatures characteristic of both stem cells and cancer cells. The observed expression differences between TAMRA+ and TAMRA- cells were validated by Real Time PCR. The results obtained corroborated the biological data that TAMRA+ murine Krebs-2 tumor cells are tumor-initiating stem cells. The approach developed can be applied to profile any poorly differentiated cell types that are capable of immanent internalization of double-stranded DNA.
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Affiliation(s)
- Ekaterina A. Potter
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - Evgenia V. Dolgova
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - Anastasia S. Proskurina
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - Yaroslav R. Efremov
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia
- Novosibirsk State University, Novosibirsk 630090, Russia
| | - Alexandra M. Minkevich
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - Aleksey S. Rozanov
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - Sergey E. Peltek
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - Valeriy P. Nikolin
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - Nelly A. Popova
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia
- Novosibirsk State University, Novosibirsk 630090, Russia
| | | | - Vladimir V. Molodtsov
- Novosibirsk State University, Novosibirsk 630090, Russia
- Softberry Inc., New York 10549, USA
| | - Evgeniy L Zavyalov
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - Oleg S. Taranov
- The State Research Center of Virology and Biotechnology VECTOR, Koltsovo, Novosibirsk 630559, Russia
| | - Sergey I. Baiborodin
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - Alexander A. Ostanin
- Institute of Clinical Immunology, Siberian Branch of the Russian Academy of Medical Sciences, Novosibirsk 630099, Russia
| | - Elena R. Chernykh
- Institute of Clinical Immunology, Siberian Branch of the Russian Academy of Medical Sciences, Novosibirsk 630099, Russia
| | - Nikolay A. Kolchanov
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - Sergey S. Bogachev
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia
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Abstract
This study re-examined the dying process in the interdigital tissue during the formation of free digits in the developing limbs. We demonstrated that the interdigital dying process was associated with cell senescence, as deduced by induction of β-gal activity, mitotic arrest, and transcriptional up-regulation of p21 together with many components of the senescence-associated secretory phenotype. We also found overlapping domains of expression of members of the Btg/Tob gene family of antiproliferative factors in the regressing interdigits. Notably, Btg2 was up-regulated during interdigit remodeling in species with free digits but not in the webbed foot of the duck. We also demonstrate that oxidative stress promoted the expression of Btg2, and that FGF2 and IGF1 which are survival signals for embryonic limb mesenchyme inhibited Btg2 expression. Btg2 overexpression in vivo and in vitro induced all the observed changes during interdigit regression, including oxidative stress, arrest of cell cycle progression, transcriptional regulation of senescence markers, and caspase-mediated apoptosis. Consistent with the central role of p21 on cell senescence, the transcriptional effects induced by overexpression of Btg2 are attenuated by silencing p21. Our findings indicate that cell senescence and apoptosis are complementary processes in the regression of embryonic tissues and share common regulatory signals.
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Abstract
Tgif1 and Tgif2 are transcriptional repressors that inhibit the transcriptional response to transforming growth factor β signaling, and can repress gene expression by direct binding to DNA. Loss of function mutations in TGIF1 are associated with holoprosencephaly (HPE) in humans. In mice, embryos lacking both Tgif1 and Tgif2 fail to complete gastrulation, and conditional double null embryos that survive past gastrulation have HPE and do not survive past mid-gestation. Here we show that in mice of a relatively pure C57BL/6 strain background, loss of Tgif1 alone results in defective axial patterning and altered expression of Hoxc6. The primary defects in Tgif1 null embryos are the presence of extra ribs on the C7 vertebra, consistent with a posterior transformation phenotype. In addition we observed defective cervical vertebrae, primarily C1-C5, in both adult mice and embryos that lacked Tgif1. The combination of Tgif1 and Tgif2 mutations increases the severity and penetrance of the posterior transformation phenotype, without altering the type of defects seen. Similarly, exposure of Tgif1 mutant embryos to retinoic acid at E8.5 increased the severity and penetrance of the Tgif1 phenotype. This suggests that Tgif1 and Tgif2 regulate axial patterning and that reduced TGIF function sensitizes embryos to the effects of retinoic acid.
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The tumor suppressor BTG1 is expressed in the developing digits and regulates skeletogenic differentiation of limb mesodermal progenitors in high density cultures. Cell Tissue Res 2015; 364:299-308. [PMID: 26662056 DOI: 10.1007/s00441-015-2331-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 11/11/2015] [Indexed: 01/07/2023]
Abstract
In the developing limb, differentiation of skeletal progenitors towards distinct connective tissues of the digits is correlated with the establishment of well-defined domains of Btg1 gene expression. Zones of high expression of Btg1 include the earliest digit blastemas, the condensing mesoderm at the tip of the growing digits, the peritendinous mesenchyme, and the chondrocytes around the developing interphalangeal joints. Gain- and loss-of function experiments in micromass cultures of skeletal progenitors reveal a negative influence of Btg1 in cartilage differentiation accompanied by up-regulation of Ccn1, Scleraxis and PTHrP. Previous studies have assigned a role to these factors in the aggregation of progenitors in the digit tips (Ccn1), in the differentiation of tendon blastemas (Scleraxis) and repressing hypertrophic cartilage differentiation (PTHrP). Overexpression of Btg1 up-regulates the expression of retinoic acid and thyroid hormone receptors, but, different from other systems, the influence of BTG1 in connective tissue differentiation appears to be independent of retinoic acid and thyroid hormone signaling.
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