Fig. 6: Effect of the injection of soluble Trem2 (sTrem2) on the heart of MI mouse.

a Treatment schedule. We made an injectable gelatin hydrogel (GH) mixed with sTrem2 and then injected it at two sites of the peri-infarcted area after MI. PBS and GH alone were also administered to the control groups. Twenty-eight days post-MI, echocardiography, and histological examination were performed to evaluate the effects of sTrem2. b Hematoxylin and eosin (H&E) stained images (upper panel) and Masson’s trichrome (MT) stained images (lower panel) of heart tissues of PBS-, GH-, and sTrem2-GH-treated groups at day 28 post-MI. Severe LV dilation was prominent in the control PBS-treated group, while a significant attenuation of LV remodeling with less infarcted wall thinning was observed in the sTrem2-GH-treated group. Results are representative of three different samples. c M-mode echocardiography images of sham operation (n = 7), PBS- (n = 6), GH- (n = 7), and sTrem2-GH-treated (n = 7) groups at day 28 post-MI. Results are representative of four different samples. d Each bar plot represents the left ventricular ejection fraction (left), fractional shortening (middle), and end-systolic volume (right) of the different groups. One-way ANOVA with two-tailed Dunnett test was used to determine the statistical significance. e Quantification of the infarct size on day 28 post-MI in PBS- (n = 8), GH- (n = 7), and sTrme2-GH- (n = 8) treated mice. One-way ANOVA with two-tailed Dunnett test was used to determine the statistical significance. f Kaplan–Meier survival analysis after MI in sham-operated (n = 5), PBS- (n = 11), GH- (n = 11), sTrem2-GH- (n = 12) treated mice. All of the bar charts are presented as mean ± SEM. Source data for d–f are provided in the Source Data file.