Genomic Instability Associated with p53 Knockdown in the Generation of Huntington's Disease Human Induced Pluripotent Stem Cells

PLoS One. 2016 Mar 16;11(3):e0150372. doi: 10.1371/journal.pone.0150372. eCollection 2016.

Abstract

Alterations in DNA damage response and repair have been observed in Huntington's disease (HD). We generated induced pluripotent stem cells (iPSC) from primary dermal fibroblasts of 5 patients with HD and 5 control subjects. A significant fraction of the HD iPSC lines had genomic abnormalities as assessed by karyotype analysis, while none of our control lines had detectable genomic abnormalities. We demonstrate a statistically significant increase in genomic instability in HD cells during reprogramming. We also report a significant association with repeat length and severity of this instability. Our karyotypically normal HD iPSCs also have elevated ATM-p53 signaling as shown by elevated levels of phosphorylated p53 and H2AX, indicating either elevated DNA damage or hypersensitive DNA damage signaling in HD iPSCs. Thus, increased DNA damage responses in the HD genotype is coincidental with the observed chromosomal aberrations. We conclude that the disease causing mutation in HD increases the propensity of chromosomal instability relative to control fibroblasts specifically during reprogramming to a pluripotent state by a commonly used episomal-based method that includes p53 knockdown.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Aged
  • Cells, Cultured
  • DNA Damage
  • Gene Knockdown Techniques*
  • Genomic Instability*
  • Humans
  • Huntington Disease / genetics
  • Huntington Disease / pathology*
  • Induced Pluripotent Stem Cells / pathology*
  • Karyotyping
  • Middle Aged
  • Nucleic Acid Synthesis Inhibitors / pharmacology
  • Signal Transduction / drug effects
  • Tumor Suppressor Protein p53 / genetics*
  • Young Adult
  • Zinostatin / pharmacology

Substances

  • Nucleic Acid Synthesis Inhibitors
  • Tumor Suppressor Protein p53
  • Zinostatin