Figure 7. IL-1β regulates cardiac electrical remodelling and cardiac arrhythmias.

(a) Experimental protocol of diabetes induction in WT and IL-1 receptor knock-out mice (IL-1r^−/−). (b) Fasting blood glucose levels at day 60 (c) Corrected QT (QTc) interval duration (n=WT: 10; lL-1r^−/−: 4; WT+DM: 10; IL-1r^−/−+DM: 5). (d) Representative traces of arrhythmic vulnerability test induced by Caff/Dobu showing a normal ECG in IL-1r^−/−+DM mice. (e) Score quantification of arrhythmia incidence and severity (n=WT: 7; lL-1r^−/−: 4; WT+DM: 7; IL-1r^−/−+DM: 5). (f) Experimental protocol for IL-1ra treatment (Anakinra, 10 mg kg⁻¹ i.p./daily/15 consecutive days). (g) Fasting blood glucose levels pre (day 60) and post (day 75) treatment (at least four mice per group). (h) Representative ECG traces highlighting QT interval pre and post treatment with saline or IL-1ra. (i,j) QTc interval values and their per cent variation pre and post treatment (for control reference please check Fig. 6j). (k) Representative ECG traces of WT+DM mice treated with IL-1ra during Caff/Dobu test, showing normal electrical function. (l) Arrhythmia score summary after IL-1ra treatment (n=saline: 6; IL-1ra: 8). The results are expressed as mean±s.e.m. Scatter plot shows values from individual mice, where horizontal bars represent means and error bars, s.e.m. * and ** represents, respectively, P<0.05 and P<0.01 (unpaired t-test). ## represent P<0.01 (Bonferroni's post test following two-way ANOVA).