Fig. 4

Lung function and remodeling in mice either vitamin D sufficient or deficient, repeatedly infected with NTHi and exposed either to CS or room air for 14 weeks (series 2). Lung function parameters A total lung capacity, TLC and B lung compliance, C chord. mRNA expression of C MMP9/TIMP1 and D MMP12/TIMP1 ratio in lung homogenate relative to RPL27. E Airspace enlargement measured via mean linear intercept. ^$$p < 0.01 (two-way ANOVA, sufficient vs deficient); ⁺p < 0.05, ⁺⁺p < 0.01, (two-way ANOVA, air vs CS); *p < 0.05, **p < 0.01, ***p < 0.001 (Bonferroni post-hoc test). Data are expressed as median ± IQR, with n = 9–15 mice/group