Figure 1. Cyclic mechanical stretch down-regulates cathelicidin antimicrobial peptide expression.

(A) VA10 cells were stretched for 6 and 24 h. The mRNA expression of cathelicidin antimicrobial peptide (CAMP) was analyzed with q-RT PCR after cell stretching (n = 3, mean ± S.E.). Relative expression levels (y-axis) in static cells were defined with an arbitrary value of ‘1’ and changes relative to this value in stretched samples are represented. (B) VA10 cells were subjected to cyclic stretch for 24 h. Cultured supernatants from stretched cells were used for analysis of secreted cathelicidin (pro-LL-37) protein expression by Western blot. Total protein loading is shown by staining with MemCode blue protein stain. The Western blot is a representative of three independent experiments showing similar results. (C) VA10 cells were stretched for 6 h and 24 h. The cells were then stained with antibody against LL-37 (green) and protein expression was visualized with immunofluorescence confocal microscopy. The cells were counterstained with nuclear stain DAPI (blue). Data is representative of three independent experiments showing similar results. Bar = 40 µm (ns indicates non-significant; p < 0.01, ^∗∗; p < 0.001, ^∗∗∗).