Fig. 8

High-mobility group box 1 (HMGB1) overexpression in mice infected with AAV9-HMGB1-Luc aggravated increased mucosal injury and inflammation in 5-fluorouracil (FU) induced mucositis model. AAV vectors were packaged into AAV9 capsids. Mice were injected with the indicated AAV vector (5 × 10¹¹ viral genomes/mouse) via intravenous. a In vivo bioluminescence images of an AAV-HMGB1-Luc-infected mouse obtained on day 14, following vector administration. Images were acquired using a Xenogen IVIS imaging system. b Western blot analysis of HMGB1 expression in tongue tissues of AAV9-HMGB1-Luc-infected or AAV9-Mock-Luc-infected mice. HMGB1 protein levels in tongue tissues were increased in AAV9-HMGB1-Luc-infected mice compared with AAV9-Luc mice. c Experimental setup for mice infected with AAV9-HMGB1-Luc or AAV9-Mock-Luc and subsequent mouse model of mucositis. d Tongues from phosphate-buffered saline (PBS)- or 5-FU-treated AAV-Mock or AAV-HMGB1-infected HMGB1 overexpression mice were stained with toluidine blue. Arrow points to surface lesion. e Bar graph shows percentage of toluidine blue-stained surface in each mouse. f Paraffin tissue sections of tongue tissues were stained with terminal deoxynucleotidyl transferase-dUTP nick-end labeling (TUNEL; upper panel), hematoxylin and eosin (middle panel), and Ki67 (lower panel). Original magnification, ×400. g Quantification (mean ± standard deviation (SD)) of the TUNEL-positive cell count in f. h, i Mucosal thickness in mouse dorsal and ventral tongue. j Quantification (mean ± SD) of the Ki67-positive cell count in f. k–m Real-time PCR analysis of nuclear factor-κB (NF-κB), tumor necrosis factor-alpha (TNF-α), and interleukin-1β (IL-1β) cytokines in tongue tissues. Results are representative of two independent experiments (n = 5–8 mice/group). *P < 0.05, **P < 0.01, ***P < 0.001