Defective myelination in an RNA polymerase III mutant leukodystrophic mouse

Emilio Merheb, Min Hui Cui, Juwen C. DuBois, Craig A. Branch, Maria Gulinello, Bridget Shafit-Zagardo, Robyn D. Moir, Ian M. Willis

Research output: Contribution to journalArticlepeer-review

Abstract

RNA polymerase (Pol) III synthesizes abundant short noncoding RNAs that have essential functions in protein synthesis, secretion, and other processes. Despite the ubiquitous functions of these RNAs, mutations in Pol III subunits cause Pol III-related leukodystrophy, an early-onset neurodegenerative disease. The basis of this neural sensitivity and the mechanisms of disease pathogenesis are unknown. Here we show that mice expressing pathogenic mutations in the largest Pol III subunit, Polr3a, specifically in Olig2-expressing cells, have impaired growth and developmental delay, deficits in cognitive, sensory, and fine sensorimotor function, and hypomyelination in multiple regions of the cerebrum and spinal cord. These phenotypes reflect a subset of clinical features seen in patients. In contrast, the gross motor defects and cerebellar hypomyelination that are common features of severely affected patients are absent in the mice, suggesting a relatively mild form of the disease in this conditional model. Our results show that disease pathogenesis in the mice involves defects that reduce both the number of mature myelinating oligodendrocytes and the ability of these cells to produce a myelin sheath of normal thickness. The findings suggest unique sensitivities of oligodendrogenesis and myelination to perturbations of Pol III transcription.

Original languageEnglish (US)
Article numbere2024378118
JournalProceedings of the National Academy of Sciences of the United States of America
Volume118
Issue number40
DOIs
StatePublished - Oct 5 2021

Keywords

  • Hypomyelination
  • Leukodystrophy
  • Oligodendrocyte
  • RNA polymerase III

ASJC Scopus subject areas

  • General

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