Page 41 - Physico-Chemical Niche Conditions for Bone Cells

experiments may only provide limited clues to the mechanisms of osteocyte mechanotransduction.
Stretch-activated ion channels and an intact glycocalyx are necessary to translate mechanical stimuli into a biochemical response [15]. We studied the interaction between glycocalyx, stretch-activated ion channels, and mechanical loading in C2C12 myoblasts, and found that removal of the glycocalyx eliminated pulsating fluid flow (PFF)-induced NO production, indicating that the glycocalyx is important for mechanosensing [15] (Fig. 2). Moreover, NO production was ablated by blocking stretch-activated ion channels (Fig. 2).
Figure 2. Schematic diagram of an experimental design to study interactions between the glycocalyx and ion channels of a cell in response to PFF. “Before” (pre-loading): With or without glycocalyx degradation and blocking of stretch-activated ion channels. “Treatment”: Glycocalyx degradation and blocking of stretch-activated ion channels. “After”: NO production by C2C12 myoblasts in response to PFF with or without glycocalyx degradation and blocking stretch-activated ion channels. Myoblasts were seeded on a glass slide and cultured for 3 days, during which a glycocalyx was formed [15]. Enzymatic removal of the glycocalyx from the cell surface was done by treatment with hyaluronic acid [15,101]. Stretch-activated ion channels were blocked by gadolinium chloride. Cells were stimulated by 1 h PFF, and NO production was measured after 0, 5, 10, 15, and 30 min [15]. PFF, pulsating fluid flow.
Unpublished results
To mimic the fluid shear stress that osteocytes are subjected to in vivo, we recently investigated the effects of PFF on cellular, cytoskeletal, and nuclear morphology in pre-
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