Rapid and highly efficient inducible cardiac gene knockout in adult mice using AAV-mediated expression of Cre recombinase

Cardiovasc Res. 2014 Oct 1;104(1):15-23. doi: 10.1093/cvr/cvu174. Epub 2014 Jul 31.

Abstract

Aims: Inducible gene targeting in mice using the Cre/LoxP system has become a valuable tool to analyse the roles of specific genes in the adult heart. However, the commonly used Myh6-MerCreMer system requires time-consuming breeding schedules and is potentially associated with cardiac side effects, which may result in transient cardiac dysfunction. The aim of our study was to establish a rapid and simple system for cardiac gene inactivation in conditional knockout mice by gene transfer of a Cre recombinase gene using adeno-associated viral vectors of serotype 9 (AAV9).

Methods and results: AAV9 vectors expressing Cre under the control of a human cardiac troponin T promoter (AAV-TnT-Cre) enabled a highly efficient Cre/LoxP switching in cardiomyocytes 2 weeks after injection into 5- to 6-week-old ROSA26-LacZ reporter mice. Recombination efficiency was at least as high as observed with the Myh6-MerCreMer system. No adverse side effects were detected upon application of AAV-TnT-Cre. As proof of principle, we studied AAV-TnT-Cre in a conditional knockout model (Srf-flex1 mice) to deplete the myocardium of the transcription factor serum response factor (SRF). Four weeks after AAV-TnT-Cre injection, a strong decrease in the cardiac expression of SRF mRNA and protein was observed. Furthermore, mice developed a severe cardiac dysfunction with increased interstitial fibrosis in accordance with the central role of SRF for the expression of contractile and calcium trafficking proteins in the heart.

Conclusions: AAV9-mediated expression of Cre is a promising approach for rapid and efficient conditional cardiac gene knockout in adult mice.

Keywords: Adeno-associated virus; Cardiomyopathy; Conditional transgenic mouse; Gene regulation; Serum response factor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cardiomyopathies / genetics
  • Cardiomyopathies / metabolism
  • Cardiomyopathies / pathology
  • Cardiomyopathies / physiopathology
  • Dependovirus / enzymology
  • Dependovirus / genetics*
  • Down-Regulation
  • Fibrosis
  • Gene Knockdown Techniques*
  • Genotype
  • Integrases / biosynthesis
  • Integrases / genetics*
  • Lac Operon
  • Male
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Myocytes, Cardiac / metabolism*
  • Myocytes, Cardiac / pathology
  • Phenotype
  • Promoter Regions, Genetic
  • RNA, Messenger / metabolism
  • RNA, Untranslated / genetics
  • Serum Response Factor / genetics
  • Serum Response Factor / metabolism
  • Time Factors
  • Troponin T / genetics
  • Ventricular Dysfunction, Left / genetics
  • Ventricular Dysfunction, Left / metabolism
  • Ventricular Dysfunction, Left / pathology
  • Ventricular Dysfunction, Left / physiopathology
  • Ventricular Function, Left

Substances

  • Gt(ROSA)26Sor non-coding RNA, mouse
  • RNA, Messenger
  • RNA, Untranslated
  • Serum Response Factor
  • Troponin T
  • Cre recombinase
  • Integrases