Fig. 9. Model of mechanical communication between contacting myofibroblasts. (A) The -SMA-positive stress fibres (green) of contacting myofibroblasts are connected to the ECM at sites of focal adhesions (FA, grey) and intercellularly at sites of OB-cadherin-type adherens junctions (AJ; light green). MS channels (violet) in the plasma membrane are closed in relaxed cells (inset A) and do not permit entrance of Ca²⁺ ions (orange). Cytoskeleton-mediated or extracellular signalling events trigger a Ca²⁺_[i] transient (indicated by orange cytoplasm). (B) This rise in Ca²⁺_[i] leads to stress fibre contraction of the left cell (indicated by thicker fibres and cell shortening) that is transmitted to the right myofibroblast at sites of adherens junctions. The induced stretch leads to the opening of MS channels (inset B). (C) The resulting influx of Ca²⁺ through open MS channels then triggers a contractile event in the right cell that again feeds back to the left myofibroblast. At this point, the cycle can start again.