Page 130 - Physico-Chemical Niche Conditions for Bone Cells
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Regulation of bone cell mitochondrial structure and dynamics
filaments, e.g. microtubules and intermediate filaments. PFF did not affect the mean branch length, possibly because the network branches were connected with each other and moved together. On the other hand, it is also possible that the increased and decreased branch number or values of branch length counterbalanced each other.
Mitochondrial network structure interacts directly or indirectly with many subcellular structures including microtubules, intermediate filaments, endoplasmic reticulum, and nucleus [29,31,54,55]. In this study, we showed movement of mitochondria and lack of movement of actin filaments in a bone cell treated by mechanical loading from top view and side view. Our results demonstrated that the mitochondria moved in the direction of loading (quantification) while actin did not (visual inspection). This could indicate that mitochondria movement may be independent of F-actin structure, as they do not move in concert, on the other hand mitochondria may have moved over / along a stable scaffold of F-actin. Future studies using actin filament disruption are needed to address this issue in more detail. During such studies, F-actin network dynamics could be quantified in greater detail, and microtubule and intermediate filament dynamics could be taken into account as well, in an attempt to understand what drives mitochondria dynamics during mechanical loading.
In conclusion, mitochondrial network structure and dynamics in a bone cell are affected by mechanical loading. The mechanosensing and mechanotransduction of mitochondria may contribute to changes in structure and function of a bone cell. Mechanical loading-induced changes in mitochondria may drive signaling pathways of cell function in aging and diseases.
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