Fig. 4. TGF-ß₁ mediates flow-induced myofibroblast differentiation. (A) Confocal images showing TGF-ß₁ and -SMA expression in mechanically constrained static (top) and flow conditions, without (middle) and with (bottom) TGF-ß₁ neutralizing antibody (red, f-actin; green, TGF-ß₁; blue, -SMA; arrow indicates flow direction). (B) TGF-ß₁ expression quantification (**P<0.01 using Dunn's test) in fibroblasts under constrained static and interstitial flow conditions for 2 days. Box plot shows 95% confidence intervals with midline showing the median. (C) -SMA expression quantification in normal compared to bioneutralized flow conditions (**P<0.01 using Mann-Whitney test). (D,E) Quantification of cell density in terms of number of cells per mm³ and cell spreading in terms of projected cell area (µm²/cell) (**P<0.01 using Dunnett's test). (F) Alignment and (G) orientation of the cells and matrix fibers under each condition (*P<0.05; **P<0.01 using Dunnett's test). Bar, 200 µm.