Fig. 6

Effects of NMN on endothelial cell dysfunction and death. Conditioned medium collected from RAW264.7 cells stimulated with LPS (LCM) for 24 h was used to simulate septic conditions. Medium from PBS-stimulated RAW264.7 cells served as a control medium (PCM). Mouse cardiac microvascular endothelial cells (MCECs) were exposed to LCM or PCM in the presence of NMN, 3-TYP or a vehicle for 24 h. A Mitochondrial ROS generation was measured in living MCECs by Mito-SOX staining. A representative microphotograph for Mito-SOX staining (red colour) and nuclear staining with Hoechst 33,342 (blue colour) from 3 independent experiments is presented. B Mitochondrial permeability transition pore (mPTP) opening was assessed using Calcein fluorescence dye. Caspase-3 activity (C) and ATP production (D) were determined in cell lysates. The mRNA levels of iNOS (E) and VCAM1 (F) relative to GAPDH were analyzed by real-time PCR. G Monolayer cell permeability was assayed by the leakage of Evans blue dye. Data are mean ± SD from 3–6 different cell cultures. *P < 0.05 vs PCM, †P < 0.05 vs LCM, and #P < 0.05 vs LCM + NMN (One-way ANOVA followed by Newman–Keuls test). H Schematic mechanisms for the protective effects of NMN on septic organ injury