Optimization of Fluorescent Labeling for In Vivo Nanoimaging of Sarcomeres in the Mouse Heart

Figure 2

Effect of collagenase treatment on the expression of -actinin-AcGFP in cardiomyocytes in vivo. (a) Top: confocal image showing uncontracted ventricular myocytes expressed with α-actinin-AcGFP by an ADV injection of 10 μL at 8 × 10¹¹ VP/mL at the center of the LV. The LV surface was pretreated with collagenase. Bar = 20 μm. Middle: enlarged view of the region of interest (indicated by yellow-rectangular region) in the confocal image in Top. Bar = 5 μm. Bottom: FI profile in the yellow-rectangular region in Top. Closed circles, plot profile of the image (raw data). Solid line, data analyzed by the multipeak Gaussian fitting. Length of 9 sarcomeres, 2.18±0.13 μm. (b) Same as in (a) in contracted myocytes in the same animal. Note contraction of all myocytes shown in this image. Length of 9 sarcomeres, 1.80±0.08 μm. P<0.001 compared with the values in (a). In (a) and (b): the Z-disks are numbered in confocal images, and “1” and “10” in FI profiles indicate fitted fluorescence signals for the corresponding Z-disks. Bar = 20 μm. Observed with a 60× lens (exposure time, 28 ms).

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