FIGURE 5.

The MAP1S deficiency leads to accumulation of autophagosomes in adult mouse cardiomyocytes under nutritive stress. A, MAP1S depletion causes accumulation of GFP-labeled autophagosomes (white dots) in fasted mouse heart tissue. +/+, wild-type mice expressing the transgenic GFP-LC3 marker; −/−, MAP1S-deficient mice expressing GFP-LC3. Images are representative of samples from three pairs of mice. B, quantification of GFP-LC3 labeled autophagosomes is shown. The number, average size, and total area occupied of GFP-LC3 punctate foci in heart tissue sections is the average and S.D. of 10 randomly selected images in a field of 512 pixel × 512 pixels. The significance of differences was determined by Student's t test. C, nutritionally stressed MAP1S-deficient mice accumulate both LC3I and II. GFP-LC3I and II was assessed with anti-LC3 antibody. Bands were quantified and expressed as percent of the GFP-LC3I intensity in unstressed wild-type mouse. The nonspecific band labeled by an asterisk appears in both GFP-LC3-expressing mice and wild-type mice that do not express GFP-LC3 (C, control). Lysates were prepared from the heart tissues of the same mice shown in A.