Fig. 6.

Azithromycin affects vacuolar ATPases and impairs the lysosomal pH. a Microarray analysis revealed the engagement of various vacuolar ATPases. Particularly ATP6V1B2 gene expression was increased, which suggests the involvement of lysosomal acidification. b ATP6V1B2 gene expression was significantly upregulated in control and IPF fibroblasts after additional AZT (T + A) compared to TGF-β alone (*p-value ≤0.0, n = 4), although no difference was observed for ATP6V1B2 between controls and IPF-FB. c ATP6V0D2 gene expression was significantly higher upregulated in controls after additional AZT (T + A) compared to IPF (*p-value ≤0.05, n = 4). d A representative histogram of control and IPF treated fibroblasts measured by flow cytometry is shown. Notably, a shift of the lysosomal pH represented by the FITC signal is seen after AZT treatment in both control and IPF fibroblasts and slightly stronger in the IPF fibroblasts. Combined data (n = 4, each) from independent experiments are shown in e AZT in the presence or absence of TGF-β induced a significant increase of the lysosomal pH in both control (n = 4, ****p-value ≤0.0001) and IPF fibroblasts (n = 4, ****p-value ≤0.0001). Lysosomal pH was significantly different between control and IPF fibroblasts after additional AZT (*p-value ≤0.05). All experiments were performed in three independent settings. One-way ANOVA followed by Tukey’s post test was used for statistical analysis