RT Journal Article
SR Electronic
T1 Dystrophin and calcium current are decreased in cardiomyocytes expressing Cre enzyme driven by αMHC but not TNT promoter
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 536789
DO 10.1101/536789
A1 Ludovic Gillet
A1 Sabrina Guichard
A1 Maria C. Essers
A1 Jean-Sébastien Rougier
A1 Hugues Abriel
YR 2019
UL http://biorxiv.org/content/early/2019/02/01/536789.abstract
AB Background The Cre/lox system is a potent technology to control gene expression in mouse tissues. However, cardiac alterations following cardiac-specific Cre enzyme expression in non-loxP-flanked genome heart have been reported. Recently, many loxP like sites have been identified in the wild-type mouse genome. Interestingly one of them is localized in the Dmd gene encoding the dystrophin protein known to be crucial for stabilization of cardiac voltage-gated ion channels Nav1.5 and Cav1.2.Aim Here, we studied the potential alteration of dystrophin expression in adult alpha-myosin heavy chain (MHC)-Cre mice, which are extensively used for cardiac-specific recombination, and investigated Troponin T (TNT)-Cre mice as a potential alternative.Methods Cardiac-specific MHC-Cre and TNT-Cre mouse lines expressing Cre recombinase under the control of the cardiac-specific alpha-myosin-heavy chain, and rat cardiac troponin T2 promoter respectively were used. Western blots, quantitative RT-PCR, immunostainings, and patch-clamp experiments were performed to characterize MHC-Cre and TNT-Cre mouse hearts and cardiomyocytes.Results Dystrophin protein level was decreased in hearts from 12-week-old MHC-Cre+ mice compared to MHC-Cre-. Reduction of dystrophin was more pronounced with age. No significant difference was observed between 8-week-old MHC-Cre+ mice and MHC-Cre-. Immunostainings performed on cardiac sections showed reduced dystrophin signal at the lateral membrane of MHC-Cre+ cardiomyocytes. Quantitative RT-PCR showed decreased mRNA levels of Dmd gene encoding dystrophin. Finally, patch-clamp experiments showed a significant decrease in calcium current (ICaL) in adult MHC-Cre+ cardiomyocytes compared to MHC-Cre-. Neither dystrophin nor ICaL was reduced in adult TNT-Cre+ mouse hearts compared to TNT-Cre-.Conclusion In contrary to TNT-Cre+ mice, the sole expression of Cre recombinase can alter the cardiac phenotype of MHC-Cre+ mice. Thus, researchers should include the “Cre-only” condition as control condition when designing experiments with Cre mouse strains.