Construction of a viral T2A-peptide based knock-in mouse model for enhanced Cre recombinase activity and fluorescent labeling of podocytes

Kidney Int. 2017 Jun;91(6):1510-1517. doi: 10.1016/j.kint.2016.12.011. Epub 2017 Feb 7.

Abstract

Podocyte injury is a key event in glomerular disease leading to proteinuria and opening the path toward glomerular scarring. As a consequence, glomerular research strives to discover molecular mechanisms and signaling pathways affecting podocyte health. The hNphs2.Cre mouse model has been a valuable tool to manipulate podocyte-specific genes and to label podocytes for lineage tracing and purification. Here we designed a novel podocyte-specific tricistronic Cre mouse model combining codon improved Cre expression and fluorescent cell labeling with mTomato under the control of the endogenous Nphs2 promoter using viral T2A-peptides. Independent expression of endogenous podocin, codon improved Cre, and mTomato was confirmed by immunofluorescence, fluorescent activated cell sorting and protein analyses. Nphs2pod.T2A.ciCre.T2A.mTomato/wild-type mice developed normally and did not show any signs of glomerular disease or off-target effects under basal conditions and in states of disease. Nphs2pod.T2A.ciCre.T2A.mTomato/wild-type-mediated gene recombination was superior to conventional hNphs2.Cre mice-mediated gene recombination. Last, we compared Cre efficiency in a disease model by mating Nphs2pod.T2A.ciCre.T2A.mTomato/wild-type and hNphs2.Cre mice to Phb2fl/fl mice. The podocyte-specific Phb2 knockout by Nphs2pod.T2A.ciCre.T2A.mTomato/wild-type mice resulted in an aggravated glomerular injury as compared to a podocyte-specific Phb2 gene deletion triggered by hNphs2.Cre. Thus, we generated the first tricistronic podocyte mouse model combining enhanced Cre recombinase efficiency and fluorescent labeling in podocytes without the need for additional matings with conventional reporter mouse lines.

Keywords: Cre recombinase; glomerulus; podocyte.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Separation / methods
  • Codon
  • Flow Cytometry
  • Fluorescent Antibody Technique
  • Gene Expression Regulation
  • Gene Knock-In Techniques*
  • Genes, Reporter*
  • Integrases / genetics*
  • Intracellular Signaling Peptides and Proteins / biosynthesis
  • Intracellular Signaling Peptides and Proteins / genetics*
  • Luminescent Proteins / biosynthesis
  • Luminescent Proteins / genetics*
  • Membrane Proteins / biosynthesis
  • Membrane Proteins / genetics*
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Peptides / genetics*
  • Podocytes / metabolism*
  • Promoter Regions, Genetic
  • Time Factors
  • Viral Proteins / genetics*

Substances

  • Codon
  • Intracellular Signaling Peptides and Proteins
  • Luminescent Proteins
  • Membrane Proteins
  • NPHS2 protein
  • Peptides
  • Viral Proteins
  • red fluorescent protein
  • Cre recombinase
  • Integrases