Fig. 7: Neutrophil gelatinase-associated lipocalin (NGAL) genetic deletion decreased intestinal fibrosis and TGF-β1 pathways in mice with chronic colitis.

Female C57BL/6 NGAL^−/− (n = 13) and DSS (n = 8) underwent 3 cycles of 2% DSS in their drinking water for 7 days, followed by 14 days of regular for both first cycles and 7 days for the third cycle. Control mice received normal drinking water (CT; n = 10). a, b Representative western blot and relative protein level of α-SMA (a, n = 5 for CT, n = 8 for DSS, n = 11 for DSS-NGAL^−/−; ordinary one way ANOVA with Tukey’s multiple comparisons test) and COL1 (b, n = 4 for CT, n = 8 for DSS, n = 10 for DSS-NGAL^−/−; Kruskal-Wallis test with Dunn’s multiple comparisons test) colon. c Hematoxylin-eosin-safran stained tissues in CT, DSS, DSS-NGAL^−/− groups and fibrosis score (n = 5 for CT, n = 7 for DSS, n = 7 for DSS-NGAL^−/−; Kruskal-Wallis test with Dunn’s multiple comparisons test). d Representative gelatine zymography and quantification of colon MMP-9 (n = 5 for CT, n = 7 for DSS, n = 9 for DSS-NGAL^−/−; Kruskal-Wallis test with Dunn’s multiple comparisons test) and MMP-2 (n = 5 for CT, n = 8 for DSS, n = 11 for DSS-NGAL^−/−; Kruskal-Wallis test with Dunn’s multiple comparisons test) activity. e Colonic TGF-β1 level (n = 5 for CT, n = 8 for DSS, n = 11 for DSS-NGAL^−/−; ordinary one-way ANOVA with Tukey’s multiple comparisons test). f Representative western blot and relative protein expression of phospho-SMAD 2/3 (p-SMAD2/SMAD2: n = 5 for CT, n = 7 for DSS, n = 11 for DSS-NGAL^−/−, ordinary one way ANOVA with Tukey’s multiple comparisons test; p-SMAD3/SMAD3: n = 5 for CT, n = 8 for DSS, n = 11 for DSS-NGAL^−/−; Kruskal-Wallis test with Dunn’s multiple comparisons test). Data are presented as mean values +/− SEM.