Fig. 3

Mechanical elongation of the RPE induces the expression of angiogenic, inflammatory and EMT genes and proteins. (a) Mechanically stressing the Transwell membrane with our device results in plastic deformation of the membrane with the highest strain occurring in the center of the stressed area. (b-p) Confocal images of three mechanically stress samples (Sample 1: b-f, Sample 2: g-k, Sample 3: l-p) showed that the expression of VEGF (d), IL-6 (i) and IL-8 (n) increased and F-actin structures were disrupted (c, h, m) due to increased mechanical stress. Z-stack images confirm the deformation of the RPE monolayer after adding mechanical stress (f, k, p). qRT-PCR results show increased expression of VEGF isoforms, VEGF121 and VEGF165, HIF-1α, ANG2, IL-6, IL-8, TNF-α and the antiangiogenic factor, PEDF (q). An increase in the expression of EMT genes, VIM and CDH2 and fibrosis gene, FN1, and a decrease in the expression of RPE-specific RPE65 was also observed (r). ELISA results showed increased apical expression of IL-6 and basal expression of VEGF, ANG2, IL-6 and IL-8 (s, t). * p < 0.05 ** p < 0.01. Error bars represent one standard deviation