Figure 1. NAD⁺ protects mice from lethal bacterial infection and endotoxic shock by dampening systemic inflammation.

(A) Mice were treated with PBS or NAD⁺ prior to administration of a lethal dose of either pathogenic E. coli or lipopolysaccharide (LPS) by intraperitoneal injection. (B) After the death of each animal, lungs, kidney and livers were removed and bacterial load was determined by counting colony-forming unit (CFU). Column plots display mean with standard deviation (n=3). (C) Survival was monitored over 48 hr after bacterial infection and (D) LPS injection of both serotypes (n=6, 3 independent survival experiments). In addition, body temperature was monitored in the kinetics of up to 100 hr. (E) Lungs, kidneys, and livers were removed and IHC was performed for hematoxylin and eosin (H&E) staining. (F) Systemic levels (serum) of IL-6, TNFα, IL-1β, and IL-18 were assessed by ELISA. Column plots display mean with standard deviation (n=5). Statistical significance was determined by using Student’s t-test or one-way ANOVA while survival data were compared using log-rank Mantel-Cox test. Asterisks indicate p-values *=p<0.05, **=p<0.01, and ***=p<0.001, only significant values are shown. All data depicted in this figure are provided as source data.

Figure 1—figure supplement 1. NAD⁺ preserves ileal villi structure and reduces splenic hemorrhage during lipopolysaccharide (LPS)-induced septic shock.

C57BL/6 mice were treated with PBS or NAD⁺ for 2 days prior to administration of a lethal dose of LPS (O55:B5/O111:B4) by intraperitoneal injection. Ileum and spleen were removed after 15 hr and subsequently IHC for hematoxylin and eosin (H&E) staining was performed. All data depicted in this figure are provided as source data.

Figure 1—figure supplement 2. Neutrophils per mm² infiltrating mice: ileum, kidney, lung, and liver in the IHC stains.

C57BL/6 mice were treated with PBS or NAD⁺ for 2 days prior to administration of a lethal dose of lipopolysaccharide (LPS) (O55:B5/O111:B4) by intraperitoneal injection. After a 15 hr interval, the ileums, lungs, kidneys, and livers were extracted and subjected to immunohistochemical staining with hematoxylin and eosin (H&E). Neutrophil quantification was performed subsequent to the immunohistochemical staining in various tissue samples. Notably, in the kidney, lung, and liver tissues, the number of neutrophils was observed to be significantly higher in the PBS-treated mice group as compared to the NAD⁺-treated mice group. Column plots display mean with standard deviation (n=4–5). Statistical significance was determined by using Student’s t-test or one-way ANOVA. Asterisks indicate p-values *=p<0.05, **=p<0.01. All data depicted in this figure are provided as source data.