Hypermethylation of 28S ribosomal RNA in β-thalassemia trait carriers

Int J Biol Macromol. 2017 Jan;94(Pt A):728-734. doi: 10.1016/j.ijbiomac.2016.10.039. Epub 2016 Oct 17.

Abstract

Ribosome biogenesis is the process of synthesis of the cellular ribosomes which mediate protein translation. Integral with the ribosomes are four cytoplasmic ribosomal RNAs (rRNAs) which show extensive post-transcriptional modifications including 2'-O-methylation and pseudouridylation. Several hereditary hematologic diseases including Diamond-Blackfan anemia have been shown to be associated with defects in ribosome biogenesis. Thalassemia is the most important hematologic inherited genetic disease worldwide, and this study examined the post-transcriptional ribose methylation status of three specific active sites of the 28S rRNA molecule at positions 1858, 4197 and 4506 of β-thalassemia trait carriers and normal controls. Samples from whole blood and cultured erythroid cells were examined. Results showed that site 4506 was hypermethylated in β-thalassemia trait carriers in both cohorts. Expression of fibrillarin, the ribosomal RNA methyltransferase as well as snoRNAs were additionally quantified by RT-qPCR and evidence of dysregulation was seen. Hemoglobin E trait carriers also showed evidence of dysregulation. These results provide the first evidence that ribosome biogenesis is dysregulated in β-thalassemia trait carriers.

Keywords: Fibrillarin; Ribosome biogenesis; rRNA methylation; β-Thalassemia.

MeSH terms

  • Case-Control Studies
  • Chromosomal Proteins, Non-Histone / genetics
  • Chromosomal Proteins, Non-Histone / metabolism*
  • Gene Expression
  • Hematopoietic Stem Cells / metabolism
  • Hematopoietic Stem Cells / pathology
  • Hemoglobin E / genetics
  • Hemoglobin E / metabolism*
  • Heterozygote
  • Humans
  • Leukocytes, Mononuclear / metabolism
  • Leukocytes, Mononuclear / pathology
  • Methylation
  • Primary Cell Culture
  • Protein Biosynthesis
  • RNA Processing, Post-Transcriptional*
  • RNA, Ribosomal, 28S / genetics
  • RNA, Ribosomal, 28S / metabolism*
  • RNA, Small Nucleolar / genetics
  • RNA, Small Nucleolar / metabolism
  • Ribosomes / genetics
  • Ribosomes / metabolism*
  • Uridine Monophosphate / genetics
  • Uridine Monophosphate / metabolism
  • beta-Thalassemia / genetics
  • beta-Thalassemia / metabolism*
  • beta-Thalassemia / pathology

Substances

  • Chromosomal Proteins, Non-Histone
  • RNA, Ribosomal, 28S
  • RNA, Small Nucleolar
  • fibrillarin
  • pseudouridylic acid
  • Hemoglobin E
  • Uridine Monophosphate