Phenotypic Screening for Friedreich Ataxia Using Random shRNA Selection

J Biomol Screen. 2015 Oct;20(9):1084-90. doi: 10.1177/1087057115600433. Epub 2015 Aug 18.

Abstract

Friedreich ataxia (FRDA) is an autosomal recessive neuro- and cardio-degenerative disorder for which there are no proven effective treatments. FRDA is caused by decreased expression and/or function of the protein frataxin. Frataxin chaperones iron in the mitochondrial matrix and regulates the iron-sulfur cluster (ISC) assembly complex. ISCs are prosthetic groups critical for the function of the Krebs cycle and the mitochondrial electron transport chain. Decreased expression of frataxin is associated with decreased ISC assembly, mitochondrial iron accumulation, and increased oxidative stress, all of which contribute to mitochondrial dysfunction. In media with beta-hydroxybutyrate (BHB) as carbon source, primary FRDA fibroblasts grow poorly and/or lose viability over several days. We screened a random, short-hairpin-RNA (shRNA)-expressing library in primary FRDA fibroblasts and identified two shRNAs that reverse the growth/viability defect in BHB media. One of these two clones increases frataxin expression in primary FRDA fibroblasts, either as a vector-expressed shRNA or as a transfected short-interfering RNA (siRNA).

Keywords: Friedreich ataxia; library; shRNA; siRNA; therapeutics.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3-Hydroxybutyric Acid / pharmacology
  • Base Sequence
  • Cells, Cultured
  • Culture Media
  • Frataxin
  • Friedreich Ataxia / genetics
  • Friedreich Ataxia / metabolism*
  • Gene Knockdown Techniques*
  • High-Throughput Nucleotide Sequencing
  • High-Throughput Screening Assays
  • Humans
  • Iron-Binding Proteins / genetics
  • Iron-Binding Proteins / metabolism
  • Molecular Sequence Data
  • Phenotype
  • RNA Interference
  • RNA, Small Interfering / genetics*
  • Sequence Analysis, DNA

Substances

  • Culture Media
  • Iron-Binding Proteins
  • RNA, Small Interfering
  • 3-Hydroxybutyric Acid