The role of telomere binding molecules for normal and abnormal hematopoiesis

Int J Hematol. 2018 Jun;107(6):646-655. doi: 10.1007/s12185-018-2432-4. Epub 2018 Mar 17.

Abstract

In order to maintain the homeostasis of the hematopoietic system, hematopoietic stem cells (HSCs) need to be maintained while slowly dividing over their lifetime. However, repeated cell divisions lead to the gradual accumulation of DNA damage and ultimately impair HSC function. Since telomeres are particularly fragile when subjected to replication stress, cells have several defense machinery to protect telomeres. Moreover, HSCs must protect their genome against possible DNA damage, while maintaining telomere length. A group of proteins called the shelterin complex are deeply involved in this two-way role, and it is highly resistant to the replication stress to which HSCs are subjected. Most shelterin-deficient experimental models suffer acute cytotoxicity and severe phenotypes, as each shelterin component is essential for telomere protection. The Tin2 point mutant mice show a dyskeratosis congenita (DC) like phenotype, and the Tpp1 deletion impairs the hematopoietic system. POT1/Pot1a is highly expressed in HSCs and contributes to the maintenance of the HSC pool during in vitro culture. Here, we discuss the role of shelterin molecules in HSC regulation and review current understanding of how these are regulated in the maintenance of the HSC pool and the development of hematological disorders.

Keywords: Dyskeratosis congenital; Extra-telomeric function; Hematopoietic stem cell; Pot1; Shelterin.

Publication types

  • Review

MeSH terms

  • Aminopeptidases / genetics
  • Animals
  • Cell Division / genetics
  • DNA Damage
  • Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / genetics
  • Dyskeratosis Congenita
  • Gene Deletion
  • Hematopoiesis / genetics*
  • Hematopoietic Stem Cells* / cytology
  • Hematopoietic Stem Cells* / physiology
  • Mice
  • Mutation
  • Serine Proteases / genetics
  • Shelterin Complex
  • Telomere*
  • Telomere-Binding Proteins / genetics
  • Telomere-Binding Proteins / physiology*
  • Telomeric Repeat Binding Protein 2 / deficiency
  • Telomeric Repeat Binding Protein 2 / physiology*

Substances

  • Acd protein, mouse
  • Shelterin Complex
  • TRF2 protein, mouse
  • Telomere-Binding Proteins
  • Telomeric Repeat Binding Protein 2
  • Tinf2 protein, mouse
  • Serine Proteases
  • Aminopeptidases
  • Dipeptidyl-Peptidases and Tripeptidyl-Peptidases