Page 17 - Physico-Chemical Niche Conditions for Bone Cells

Chapter 1
Figure 1. Schematic diagram of the integrin-cytoskeleton-nucleus extracellular matrix system showing a continuous connection between the ECM, via the cytoskeleton, to the nucleus. The osteoblast/osteocyte niche contains proteoglycans, collagen type 1, and fibronectin, which connects with integrins. The integrins link to the actin cytoskeleton via a complex consisting of the signal transducer adaptor protein paxillin, and structural cytoskeletal proteins talin (a mechanosensitive protein), vinculin, and a-actinin. Integrins might also function together with the intermediate filament cytoskeleton to mediate cell adhesion. Microtubules interact with integrin-containing focal adhesions and modulate adhesion turnover and cellular signaling. A mechanical signal is transmitted from the cytoskeleton to the membrane of the nucleus via nesprins and SUN proteins. ECM: extracellular matrix; FAK: focal adhesion kinase.
Mechanical stimuli are not only transmitted to the nucleus via cytoskeletal filaments, but also to the mitochondria which directly or indirectly connect to the cytoskeletal filaments [49]. External mechanical stimuli affect the mitochondrial structure (shape) and function in
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