Gene therapy in patient-specific stem cell lines and a preclinical model of retinitis pigmentosa with membrane frizzled-related protein defects

Mol Ther. 2014 Sep;22(9):1688-97. doi: 10.1038/mt.2014.100. Epub 2014 Jun 4.

Abstract

Defects in Membrane Frizzled-related Protein (MFRP) cause autosomal recessive retinitis pigmentosa (RP). MFRP codes for a retinal pigment epithelium (RPE)-specific membrane receptor of unknown function. In patient-specific induced pluripotent stem (iPS)-derived RPE cells, precise levels of MFRP, and its dicistronic partner CTRP5, are critical to the regulation of actin organization. Overexpression of CTRP5 in naïve human RPE cells phenocopied behavior of MFRP-deficient patient RPE (iPS-RPE) cells. AAV8 (Y733F) vector expressing human MFRP rescued the actin disorganization phenotype and restored apical microvilli in patient-specific iPS-RPE cell lines. As a result, AAV-treated MFRP mutant iPS-RPE recovered pigmentation and transepithelial resistance. The efficacy of AAV-mediated gene therapy was also evaluated in Mfrp(rd6)/Mfrp(rd6) mice--an established preclinical model of RP--and long-term improvement in visual function was observed in AAV-Mfrp-treated mice. This report is the first to indicate the successful use of human iPS-RPE cells as a recipient for gene therapy. The observed favorable response to gene therapy in both patient-specific cell lines, and the Mfrp(rd6)/Mfrp(rd6) preclinical model suggests that this form of degeneration caused by MFRP mutations is a potential target for interventional trials.

Publication types

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

MeSH terms

  • Animals
  • Cell Line
  • Collagen / metabolism
  • Dependovirus / genetics
  • Dependovirus / metabolism
  • Disease Models, Animal
  • Female
  • Genetic Therapy
  • Genetic Vectors / administration & dosage
  • Humans
  • Induced Pluripotent Stem Cells / metabolism*
  • Induced Pluripotent Stem Cells / virology
  • Male
  • Membrane Proteins / genetics*
  • Membrane Proteins / metabolism*
  • Mice
  • Mice, Inbred C57BL
  • Middle Aged
  • Phenotype
  • Retinal Pigment Epithelium / cytology*
  • Retinitis Pigmentosa / pathology
  • Retinitis Pigmentosa / therapy*
  • Young Adult

Substances

  • C1QTNF5 protein, human
  • MFRP protein, human
  • Membrane Proteins
  • Collagen