An inducible Cre mouse for studying roles of the RPE in retinal physiology and disease

JCI Insight. 2021 May 10;6(9):e146604. doi: 10.1172/jci.insight.146604.

Abstract

The retinal pigment epithelium (RPE) provides vital metabolic support for retinal photoreceptor cells and is an important player in numerous retinal diseases. Gene manipulation in mice using the Cre-LoxP system is an invaluable tool for studying the genetic basis of these retinal diseases. However, existing RPE-targeted Cre mouse lines have critical limitations that restrict their reliability for studies of disease pathogenesis and treatment, including mosaic Cre expression, inducer-independent activity, off-target Cre expression, and intrinsic toxicity. Here, we report the generation and characterization of a knockin mouse line in which a P2A-CreERT2 coding sequence is fused with the native RPE-specific 65 kDa protein (Rpe65) gene for cotranslational expression of CreERT2. Cre+/- mice were able to recombine a stringent Cre reporter allele with more than 99% efficiency and absolute RPE specificity upon tamoxifen induction at both postnatal days (PD) 21 and 50. Tamoxifen-independent Cre activity was negligible at PD64. Moreover, tamoxifen-treated Cre+/- mice displayed no signs of structural or functional retinal pathology up to 4 months of age. Despite weak RPE65 expression from the knockin allele, visual cycle function was normal in Cre+/- mice. These data indicate that Rpe65CreERT2 mice are well suited for studies of gene function and pathophysiology in the RPE.

Keywords: Genetics; Mouse models; Ophthalmology; Retinopathy.

Publication types

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

MeSH terms

  • Animals
  • Disease Models, Animal*
  • Gene Knock-In Techniques
  • Integrases / genetics
  • Mice*
  • Mice, Transgenic
  • Models, Animal*
  • Receptors, Estrogen / genetics*
  • Reproducibility of Results
  • Retinal Diseases / genetics*
  • Retinal Diseases / metabolism
  • Retinal Diseases / physiopathology
  • Retinal Pigment Epithelium / metabolism*
  • Retinal Pigment Epithelium / physiopathology
  • Selective Estrogen Receptor Modulators / pharmacology
  • Tamoxifen / pharmacology
  • cis-trans-Isomerases / genetics*
  • cis-trans-Isomerases / metabolism

Substances

  • Receptors, Estrogen
  • Selective Estrogen Receptor Modulators
  • Tamoxifen
  • Cre recombinase
  • Integrases
  • retinoid isomerohydrolase
  • cis-trans-Isomerases