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RBL2 bi-allelic truncating variants cause severe motor and cognitive impairment without evidence for abnormalities in DNA methylation or telomeric function

Journal of Human Genetics volume 66, pages 1101–1112 (2021)Cite this article

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Abstract

RBL2/p130, a member of the retinoblastoma family of proteins, is a key regulator of cell division and propagates irreversible senescence. RBL2/p130 is also involved in neuronal differentiation and survival, and eliminating Rbl2 in certain mouse strains leads to embryonic lethality accompanied by an abnormal central nervous system (CNS) phenotype. Conflicting reports exist regarding a role of RBL2/p130 in transcriptional regulation of DNA methyltransferases (DNMTs), as well as the control of telomere length. Here we describe the phenotype of three patients carrying bi-allelic RBL2-truncating variants. All presented with infantile hypotonia, severe developmental delay and microcephaly. Malignancies were not reported in carriers or patients. Previous studies carried out on mice and human cultured cells, associated RBL2 loss to DNA methylation and telomere length dysregulation. Here, we investigated whether patient cells lacking RBL2 display related abnormalities. The study of primary patient fibroblasts did not detect abnormalities in expression of DNMTs. Furthermore, methylation levels of whole genome DNA, and specifically of pericentromeric repeats and subtelomeric regions, were unperturbed. RBL2-null fibroblasts show no evidence for abnormal elongation by telomeric recombination. Finally, gradual telomere shortening, and normal onset of senescence were observed following continuous culturing of RBL2-mutated fibroblasts. Thus, this study resolves uncertainties regarding a potential non-redundant role for RBL2 in DNA methylation and telomere length regulation, and indicates that loss of function variants in RBL2 cause a severe autosomal recessive neurodevelopmental disorder in humans.

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References

  1. Claudio PP, Tonini T, Giordano A. The retinoblastoma family: twins or distant cousins? Genome Biol. 2002;3:1–9.

    Article  Google Scholar 

  2. Graña X, Garriga J, Mayol X. Role of the retinoblastoma protein family, pRB, p107 and p130 in the negative control of cell growth. Oncogene. 1998;17:3365–83.

    Article  PubMed  Google Scholar 

  3. Indovina P, Marcelli E, Casini N, Rizzo V, Giordano A. Emerging roles of RB family: new defense mechanisms against tumor progression. J Cell Physiol. 2013;228:525–35.

    Article  CAS  PubMed  Google Scholar 

  4. Fiorentino FP, Symonds CE, MacAluso M, Giordano A. Senescence and p130/Rbl2: a new beginning to the end. Cell Res. 2009;19:1044–51.

    Article  PubMed  Google Scholar 

  5. Vélez-Cruz R, Johnson DG. The retinoblastoma (RB) tumor suppressor: Pushing back against genome instability on multiple fronts. Int J Mol Sci. 2017;18:1776.

    Article  PubMed Central  CAS  Google Scholar 

  6. Popov B, Chang LS, Serikov V. Cell cycle-related transformation of the E2F4-p130 repressor complex. Biochem Biophys Res Commun. 2005;336:762–9.

    Article  CAS  PubMed  Google Scholar 

  7. Hannon G, Demetrick D, Beach D. Isolation of the Rb-related p130 through its interaction with CDK2 and cyclins. Genes Dev. 1993;7:2378–91.

    Article  CAS  PubMed  Google Scholar 

  8. Cobrinik D. Pocket proteins and cell cycle control. Oncogene. 2005;24:2796–809.

    Article  CAS  PubMed  Google Scholar 

  9. Kusek JC, Greene RM, Pisano MM. Expression of the E2F and retinoblastoma families of proteins during neural differentiation. Brain Res Bull. 2001;54:187–98.

    Article  CAS  PubMed  Google Scholar 

  10. Lui DX, Nath N, Chellappan SP, Greene LA. Regulation of neuron survival and death by p130 and associated chromatin modifiers. Genes Dev. 2005;19:719–32.

    Article  CAS  Google Scholar 

  11. Lecouter JE, Kablar B, Whyte PFM, Rudnicki CYMA. Strain-dependent embryonic lethality in mice lacking the retinoblastoma-related p130 gene. Development. 1998;125:4669–79.

    Article  CAS  PubMed  Google Scholar 

  12. Brunet T, Radivojkov-Blagojevic M, Lichtner P, Kraus V, Meitinger T, Wagner M. Biallelic loss-of-function variants in RBL2 in siblings with a neurodevelopmental disorder. Ann Clin Transl Neurol. 2020;7:390–6.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  13. Helmbold H, Galderisi U, Bohn W. The switch from pRb/p105 to Rb2/p130 in DNA damage and cellular senescence. J Cell Physiol. 2012;227:508–13.

    Article  CAS  PubMed  Google Scholar 

  14. Benetti R, Gonzalo S, Jaco I, Muñoz P, Gonzalez S, Schoeftner S, et al. A mammalian microRNA cluster controls DNA methylation and telomere recombination via Rbl2-dependent regulation of DNA methyltransferases. Nat Struct Mol Biol. 2008;15:268–79.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  15. Sinkkonen L, Hugenschmidt T, Berninger P, Gaidatzis D, Mohn F, Artus-Revel CG, et al. MicroRNAs control de novo DNA methylation through regulation of transcriptional repressors in mouse embryonic stem cells. Nat Struct Mol Biol. 2008;15:259–67.

    Article  CAS  PubMed  Google Scholar 

  16. Lu F, Stedman W, Yousef M, Renne R, Lieberman PM. Epigenetic regulation of Kaposi’s sarcoma-associated herpesvirus latency by virus-encoded microRNAs that target Rta and the cellular Rbl2-DNMT pathway. J Virol. 2010;84:2697–706.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  17. Smith JA, Ndoye AMN, Geary K, Lisanti MP, Igoucheva O, Daniel R. A role for the Werner syndrome protein in epigenetic inactivation of the pluripotency factor Oct4. Aging Cell. 2010;9:580–91.

    Article  CAS  PubMed  Google Scholar 

  18. Ip J, Canham P, Choo KHA, Inaba Y, Jacobs SA, Kalitsis P, et al. Normal DNA methylation dynamics in DICER1-deficient mouse embryonic stem cells. PLoS Genet. 2012;8:e1002919.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  19. Allsopp RC, Vaziri H, Patterson C, Goldstein S, Younglai EV, Futcher AB, et al. Telomere length predicts replicative capacity of human fibroblasts. Proc Natl Acad Sci USA. 1992;89:10114–8.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  20. Harley CB, Futcher AB, Greider CW. Telomeres shorten during ageing of human fibroblasts. Nature. 1990;345:458–60.

    Article  CAS  PubMed  Google Scholar 

  21. Mathew R, Jia W, Sharma A, Zhao Y, Clarke LE, Cheng X, et al. Robust activation of the human but not mouse telomerase gene during the induction of pluripotency. Faseb J. 2010;24:2702–15.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  22. Shay JW, Wright WE. Role of telomeres and telomerase in cancer. Semin Cancer Biol. 2011;21:349–53.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  23. Henson JD, Neumann AA, Yeager TR, Reddel RR. Alternative lengthening of telomeres in mammalian cells. Oncogene 2002;21:598–610.

    Article  CAS  PubMed  Google Scholar 

  24. Crowe DL, Nguyen DC. Rb and E2F-1 regulate telomerase activity in human cancer cells. Biochim Biophys Acta - Gene Struct Expr. 2001;1518:1–6.

    Article  CAS  Google Scholar 

  25. Won J, Chang S, Oh S, Kim TK. Small-molecule-based identification of dynamic assembly of E2F-pocket protein-histone deacetylase complex for telomerase regulation in human cells. Proc Natl Acad Sci USA. 2004;101:11328–33.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  26. Gizard F, Nomiyama T, Zhao Y, Findeisen HM, Heywood EB, Jones KL, et al. The PPARα/p16INK4a pathway inhibits vascular smooth muscle cell proliferation by repressing cell cycle-dependent telomerase activation. Circ Res. 2008;103:1155–63.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  27. Kong LJ, Meloni AR, Nevins JR. The Rb-related p130 protein controls telomere lengthening through an interaction with a Rad50-interacting protein, RINT-1. Mol Cell. 2006;22:63–71.

    Article  CAS  PubMed  Google Scholar 

  28. Yalon M, Gal S, Segev Y, Selig S, Skorecki KL. Sister chromatid separation at human telomeric regions. J Cell Sci. 2004;117:1961–70.

    Article  CAS  PubMed  Google Scholar 

  29. Shinnawi R, Huber I, Maizels L, Shaheen N, Gepstein A, Arbel G, et al. Monitoring human-induced pluripotent stem cell-derived cardiomyocytes with genetically encoded calcium and voltage fluorescent reporters. Stem Cell Rep. 2015;5:582–96.

    Article  CAS  Google Scholar 

  30. Toubiana S, Gagliardi M, Papa M, Manco R, Tzukerman M, Matarazzo MR, et al. Persistent epigenetic memory impedes rescue of the telomeric phenotype in human ICF iPSCs following DNMT3B correction. Elife. 2019;8:e47859.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  31. Dimri GP, Lee X, Basile G, Acosta M, Scott G, Roskelley C, et al. A biomarker that identifies senescent human cells in culture and in aging skin in vivo. Proc Natl Acad Sci USA. 1995;92:9363–7.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  32. Shlush LI, Itzkovitz S, Cohen A, Rutenberg A, Berkovitz R, Yehezkel S, et al. Quantitative digital in situ senescence-associated β-galactosidase assay. BMC Cell Biol. 2011;12:16.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  33. Sagie S, Edni O, Weinberg J, Toubiana S, Kozlovski T, Frostig T, et al. Non-random length distribution of individual telomeres in immunodeficiency, centromeric instability and facial anomalies syndrome, type I. Hum Mol Genet. 2017;26:4244–56.

    Article  CAS  PubMed  Google Scholar 

  34. Toubiana S, Velasco G, Chityat A, Kaindl AM, Hershtig N, Tzur-Gilat A, et al. Subtelomeric methylation distinguishes between subtypes of Immunodeficiency, Centromeric instability and Facial anomalies syndrome. Hum Mol Genet. 2018;27:3568–81.

    Article  CAS  PubMed  Google Scholar 

  35. Yehezkel S, Segev Y, Viegas-Pequignot E, Skorecki K, Selig S. Hypomethylation of subtelomeric regions in ICF syndrome is associated with abnormally short telomeres and enhanced transcription from telomeric regions. Hum Mol Genet. 2008;17:2776–89.

    Article  CAS  PubMed  Google Scholar 

  36. Poon SS, Lansdorp PM. Measurements of telomere length on individual chromosomes by image cytometry. Methods Cell Biol. 2001;64:69–96.

    Article  CAS  PubMed  Google Scholar 

  37. Greenberg MVC, Bourc’his D. The diverse roles of DNA methylation in mammalian development and disease. Nat Rev Mol Cell Biol. 2019;20:590–607.

    Article  CAS  PubMed  Google Scholar 

  38. Saravanaraman P, Selvam M, Ashok C, Srijyothi L, Baluchamy S. De novo methyltransferases: potential players in diseases and new directions for targeted therapy. Biochimie. 2020;176:85–102.

    Article  CAS  PubMed  Google Scholar 

  39. Gonzalo S, García-Cao M, Fraga MF, Schotta G, Peters AH, Cotter SE, et al. Role of the RB1 family in stabilizing histone methylation at constitutive heterochromatin. Nat Cell Biol. 2005;7:420–8.

    Article  CAS  PubMed  Google Scholar 

  40. Okano M, Bell DW, Haber DA, Li E. DNA methyltransferases Dnmt3a and Dnmt3b are essential for de novo methylation and mammalian development. Cell. 1999;99:247–57.

    Article  CAS  PubMed  Google Scholar 

  41. Thoraval D, Asakawa J, Kodaira M, Chang C, Radany E, Kuick R, et al. A methylated human 9-kb repetitive sequence on acrocentric chromosomes is homologous to a subtelomeric repeat in chimpanzees. Proc Natl Acad Sci USA. 1996;93:4442–7.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  42. Dumbović G, Biayna J, Banús J, Samuelsson J, Roth A, Diederichs S, et al. A novel long non-coding RNA from NBL2 pericentromeric macrosatellite forms a perinucleolar aggregate structure in colon cancer. Nucleic Acids Res. 2018;46:5504–24.

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  43. Toubiana S, Selig S. Human subtelomeric DNA methylation: regulation and roles in telomere function. Curr Opin Genet Dev. 2020;60:9–16.

    Article  CAS  PubMed  Google Scholar 

  44. Allsopp RC, Chang E, Kashefi-Aazam M, Rogaev EI, Piatyszek MA, Shay JW, et al. Telomere shortening is associated with cell division in vitro and in vivo. Exp Cell Res. 1995;220:194–200.

    Article  CAS  PubMed  Google Scholar 

  45. Chinnam M, Goodrich DW. RB1, development and cancer. Curr Top Dev Biol; 2011;94:129–169.

  46. Yehezkel S, Shaked R, Sagie S, Berkovitz R, Shachar-Bener H, Segev Y, et al. Characterization and rescue of telomeric abnormalities in ICF syndrome type I fibroblasts. Front Oncol. 2013;3:35.

  47. Deng Z, Campbell AE, Lieberman PM. TERRA, CpG methylation and telomere heterochromatin: lessons from ICF syndrome cells. Cell Cycle. 2010;9:69–74.

    Article  CAS  PubMed  Google Scholar 

  48. García-Cao M, Gonzalo S, Dean D, Blasco MA. A role for the Rb family of proteins in controlling telomere length. Nat Genet. 2002;32:415–9.

    Article  PubMed  CAS  Google Scholar 

  49. Chudasama P, Mughal SS, Sanders MA, Hübschmann D, Chung I, Deeg KI, et al. Integrative genomic and transcriptomic analysis of leiomyosarcoma. Nat Commun. 2018;9:144. 1

    Article  PubMed  PubMed Central  CAS  Google Scholar 

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Acknowledgements

We are grateful for the families support and willingness to participate in this research study. We thank Tamar Paperna and Daniel Kornitzer for comments on the manuscript. ST is grateful to The Edmond de Rothschild Foundation (IL) for funding her PhD scholarship. This work was supported by the Israel Science Foundation [grant number 1362/17 to SS]. KW is supported by the Clinical Research Institute at Rambam.

Author information

Author notes

  1. Adi Mory & Hagit Baris Feldman

    Present address: The Genetics Institute, Tel Aviv Sourasky Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel

  2. These authors contributed equally: Sara Selig, Karin Weiss

Authors and Affiliations

  1. Genetic Unit, Ziv Medical Center, Tzfat, Israel

    Nadra Samra & Ilham Morani

  2. Faculty of Medicine, Bar Ilan University, Tzfat, Israel

    Nadra Samra

  3. Department of Genetics and Developmental Biology, The Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel

    Shir Toubiana, Aya Tzur-Gilat, Liran Giladi & Sara Selig

  4. Department of Medical Genetics, University Hospital of North Norway, Tromsø, Norway

    Hilde Yttervik

  5. The Clinical Research Institute at Rambam Health Care Campus, Haifa, Israel

    Chen Itzkovich

  6. Ziv Medical Center, Tzfat, Israel

    Kamal Abu Jabal

  7. Section of Hematology Oncology, Departments of Medicine and Human Genetics, The University of Chicago, Chicago, IL, USA

    John Z. Cao & Lucy A. Godley

  8. The Genetics Institute, Rambam Health Care Campus, Haifa, Israel

    Adi Mory, Hagit Baris Feldman & Karin Weiss

  9. The Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel

    Hagit Baris Feldman & Karin Weiss

  10. Department of Medical Genetics, Telemark Hospital Trust, Skien, Norway

    Kristian Tveten

  11. Laboratory of Molecular Medicine, Rambam Health Care Campus, Haifa, Israel

    Sara Selig

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Correspondence to Sara Selig.

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Samra, N., Toubiana, S., Yttervik, H. et al. RBL2 bi-allelic truncating variants cause severe motor and cognitive impairment without evidence for abnormalities in DNA methylation or telomeric function. J Hum Genet 66, 1101–1112 (2021). https://doi.org/10.1038/s10038-021-00931-z

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