Fig. 1

Genetic knockdown of LITAF (lipopolysaccharide-induced tumor necrosis factor) increases calcium transients in the heart of zebrafish embryos. Zebrafish hearts from 48 hpf (hours post-fertilization) wild-type (WT) and LITAF morphants (MO) were stained with Fura-2 AM (Fura-2-acetoxymethyl ester) to measure Ca2+ transients. A, Structure of human and zebrafish LITAF with conserved PXY and P(S/T)AP motifs and the hydrophobic region (HR) required for membrane embedding.49 Also indicated are 2 conserved cysteine pairs for coordination of a zinc atom likely required for proper protein folding.49 B, Averaged ventricular Ca2+ transients (amplitudes and baselines) from regions of interest (ROIs) as indicated in the color maps. C, Color maps of Ca2+ transient amplitudes from WT and LITAF morphant hearts. Color code depicts Ca2+ transient amplitudes in fluorescence ratio units (F340/F380). Squares indicate ROIs for measurements averaged in B. D, Mean baseline ratios. E, Mean Ca2+ transient amplitudes. Error bars depict SEM. One-way ANOVA, *P<0.05 for comparisons with WT (n=9 wild-type zebrafish embryos; n=7 LITAF morphants).