Double Transgenic Mice Crossed GFP-LC3 Transgenic Mice With .ALPHA.MyHC-mCherry-LC3 Transgenic Mice Are a New and Useful Tool to Examine the Role of Autophagy in the Heart

Abstract

Background:The involvement of autophagy in heart disease has been reported. Transgenic mice expressing GFP-LC3 have been a useful tool in detecting autophagosomes systemically. It is difficult to differentiate increased formation of autophagosomes from decreased clearance of autophagosomes in the heart using GFP-LC3 mice. Methods and Results:We generated transgenic mice expressing mCherry-LC3 under αMyHC promoter and crossed the mice with transgenic mice expressing GFP-LC3. The deference of resistance to acidic conditions between GFP and mCherry overcame the limitation. Conclusions:This method is an innovative approach to examine the role of autophagy and to analyze autophagosome maturation in cardiomyocytes. (Circ J 2010; 74: 203 - 206)

Novel In Vivo Tool to Evaluate Autophagic Activity in the Heart

“…14 As with mRFP, mCherry also does not lose fluorescence under acidic conditions in autolysosomes (Figure A). This transgenic mouse enables detection of not only autophagosomes but also autolysosomes.…”

“…14 The chloroquine treatment increased the number of both autophagosomes and autolysosomes. It has been previously reported that autophagic flux can be evaluated in the in vivo heart using MDC and chloroquine, 15 but there remains a possibility of undesirable effects of chloroquine.…”

Autophagy regulation in the development and treatment of breast cancer

“…Atg5 −/− mice are documented as autophagy deficient, and Atg5 −/− ; GFP-LC3 mice show no indication of autophagosome formation [15,90]. Mouse models with systemic mosaic deletion of Atg5 or liverspecific Atg7 −/− develop liver adenomas.…”

Altering Autophagy: Mouse Models of Human Disease

“…A cardiac muscle specific alpha myosin heavy chain (αMyHC) promoter was used to drive expression of a mCherry-LC3 construct. These mice were crossed with the GFP-LC3 model previously described to produce a double reporter which allowed for the monitoring of autophagic flux; autophagosomes were identified by GFP and mCherry co-localized puncta, while autolysosomes were tracked by mCherry-only puncta [3]. Although this model is cardiac-specific, a similar strategy could be used to target other tissues.…”