Figure 1A,B NAD and nicotinamide (NAM) levels in heart of WT (n=5, n=6, respectively), mdx (n=5, n=5, respectively) and mdx/CD38-/- mice (n=6, n=5, respectively). C,D NAD and NAM levels in diaphragm of WT (n=5, n=6, respectively), mdx (n=4, n=5, respectively) and mdx/CD38-/- mice (n=6, n=5, respectively). Data information: Each dot of the graphs represents a mouse and measured in duplicate After normality and variance comparison tests, significance was assessed using: ANOVA followed by Fisher's LSD test; B: Kruskal-Wallis followed by Dunn's test; D: Kruskal-Wallis followed by Mann-Whitney tests; Values are expressed as means ± SEM. Significance: *p<0.05, **p<0.01, ***p<0.001. E,F levels of ADP-ribose (ADPR) (E), cyclic ADP-ribose (cADPR) (F) expressed as nmol/mg protein in heart of WT (n=6), mdx (n=5) and mdx/CD38-/- mice (n=5, n=5, n=6 respectively). Data information: Each dot of the graphs represents a mouse and measured in duplicate After normality and variance comparison tests, significance was assessed using: : ANOVA followed by Fisher's LSD test; Values are expressed as means ± SEM. Significance: *p<0.05, **p<0.01, ***p<0.001. (G) qPCR analysis of mRNA levels of Sterile alpha and Toll/interleukin-1 receptor motif-containing 1 (SARM1) in heart of WT (n=6), mdx (n=5) and mdx/CD38-/- mice (n=5, n=5, n=6 respectively). Data information: Each dot of the graphs represents a mouse and measured in duplicate After normality and variance comparison tests, significance was assessed using: ANOVA followed by Fisher's LSD test; Values are expressed as means ± SEM. Significance: *p<0.05, **p<0.01, ***p<0.001. H,I Levels of ADPR (H), cADPR (I) expressed as nmol/mg protein in diaphragm of WT (n=6), mdx (n=5) and mdx/CD38-/- (n=5) mice. Data information: Each dot of the graphs represents a mouse and measured in duplicate After normality and variance comparison tests, significance was assessed using: ANOVA followed by Fisher's LSD test; ; I: Welch's ANOVA followed by Welch's t-tests Values are expressed as means ± SEM. Significance: *p<0.05, **p<0.01, ***p<0.001. (J) qPCR analysis mRNA levels of SARM1 in diaphragm of WT (n=6), mdx (n=5) and mdx/CD38-/- (n=5) mice. Data information: Each dot of the graphs represents a mouse and measured in duplicate After normality and variance comparison tests, significance was assessed using: J: ANOVA Values are expressed as means ± SEM. Significance: *p<0.05, **p<0.01, ***p<0.001. K, L Western blot analysis of CD38 protein expression in heart (K) and diaphragm (L) of WT (n=5, n=6, respectively) and mdx (n=5) mice. Vinculin is used as housekeeping protein control and the dot plots show the ratio of CD38/vinculin. Data information: Each dot of the graphs represents a value/mouse. After normality and variance comparison tests, significance was assessed using: unpaired Student's t-test; Values are expressed as means ± SEM. Significance: *p<0.05, **p<0.01, ***p<0.001. M, N qPCR analysis of CD38 mRNA levels in heart (M) and diaphragm (N) of WT (n=6) and mdx (n=5) mice. Data information: Each dot of the graphs represents a mouse and measured in duplicate After normality and variance comparison tests, significance was assessed using: M: unpaired Student's t-test; N: unpaired Welch's t-test. Values are expressed as means ± SEM. Significance: *p<0.05, **p<0.01, ***p<0.001.