Heart laser injury causes localized cardiomyocyte cell death. (A) Whole larva brightfield image of 3 dpf zebrafish with heart region indicated (black square), scale bar = 500 μm. (B) Brightfield images of a 3 dpf larval heart pre-laser injury (left) and 1-min post laser injury (right). The lesion is seen as a thickened and partially collapsed region at the ventricular apex (black arrowhead). (C) Ventricular ejection fraction before injury, and 2 hpi in injured and uninjured larvae. Error bars = SEM, n = 15–20 larvae, experimental n = 3. Unpaired t-test performed between groups where **** p < 0.0001. (D) Epifluorescence images of an uninjured and injured Tg(myl7:GFP) heart. Injury site is marked by a loss of myocardial GFP at the ventricular apex (white dashed line and arrowhead). (E) 3D LSFM image of a TUNEL stained injured Tg(myl7:h2b-GFP) heart at 2 hpi. Injury site is marked by a loss of nuclear myocardial GFP (white arrowhead) bordered by TUNEL positive cells (magenta). Image displayed as a maximum intensity projection (MIP). (F) LSFM single z-plane image of a Tg(myl7:mCherry;nfkb:GFP) ventricle at 2 and 24 hpi following heart injury. White arrowheads indicate loss of myocardial signal at 2 hpi and upregulation of nfkb:GFP in wound-bordering cardiomyocytes at 24 hpi. (G) 3D LSFM image of Tg(nfkb:GFP) ventricular expression at 24 hpi in uninjured and injured larvae (black arrowhead indicates ventricular apex injury site). Image displayed as a MIP (inverse color map). All scale bars = 50 μm unless stated otherwise. V, ventricle; A, atrium; ns, non-significant.
|
