Morphological changes in the mitochondria of bone marrow stromal cells of mice subjected to simulated hypokinesia
Abstract
Bone marrow, which harbors populations of different progenitor cells, in particular osteogenic cells, plays a special role in the development of immobilization-mediated bone disorders. Mitochondria are a vital component in the physiology of these cells. Changes in mitochondrial activity are determined not only by biochemical processes but also by their structural dynamics.
The aim of this study was to quantitatively assess changes in the morphology of mitochondria in a culture of bone marrow stromal cells after exposure to hypokinesia in mice.
Materials and methods. Male ICR mice weighing 23,0 ± 1,5 g were subjected to simulated hypokinesia for 7 days, followed by isolation of bone marrow cells from the femurs. The primary culture was grown under standard conditions on a complete nutrient medium. On day 6, the cells were subcultured and 24 hours later, the morphological assessment of the mitochondria was carried out using the laser scanning confocal fluorescent microscopy (LSCM) technique followed by mathematical processing and analysis of 3D-images.
Results. The total volume and surface area of mitochondria in cells in the «Hypokinesia» group were 4 and 1,73 times smaller, respectively, compared to the «Control» group. In terms of volume, the cells themselves in the «Hypokinesia» group were 3,26 times smaller than in «Control». A quantitative assessment of the morphological differences in the mitochondria was carried out by calculating the ratio of the total surface area of all mitochondria in a cell to their total volume. This parameter in the cells of mice from the «Hypokinesia» group exceeded that in the «Control» by 2,3 times.
Conclusion. After 7 days of restriction of animal mobility, changes in mitochondrial morphology were observed in bone marrow stromal cells. The resulting numerical difference indicates a higher fragmentation or tortuosity of the mitochondrial network in the cells of the «Hypokinesia» group.
