Baskan Oznur, Mese Gulistan, Ozcivici Engin
1 Department of Bioengineering, Izmir Institute of Technology, Izmir, Turkey.
2 Department of Molecular Biology and Genetics, Izmir Institute of Technology, Izmir, Turkey.
Proc Inst Mech Eng H. 2017 Feb;231(2):160-168. doi: 10.1177/0954411916687338. Epub 2017 Jan 10.
Bone marrow mesenchymal stem cells that are committed to adipogenesis were exposed daily to high-frequency low-intensity mechanical vibrations to understand molecular, morphological and ultrastructural adaptations to mechanical signals during adipogenesis. D1-ORL-UVA mouse bone marrow mesenchymal stem cells were cultured with either growth or adipogenic medium for 1 week. Low-intensity vibration signals (15 min/day, 90 Hz, 0.1 g) were applied to one group of adipogenic cells, while the other adipogenic group served as a sham control. Cellular viability, lipid accumulation, ultrastructure and morphology were determined with MTT, Oil-Red-O staining, phalloidin staining and atomic force microscopy. Semiquantitative reverse transcription polymerase chain reaction showed expression profile of the genes responsible for adipogenesis and ultrastructure of cells. Low-intensity vibration signals increased viability of the cells in adipogenic culture that was reduced significantly compared to quiescent controls. Low-intensity vibration signals also normalized the effects of adipogenic condition on cell morphology, including area, perimeter, circularization and actin cytoskeleton. Furthermore, low-intensity vibration signals reduced the expression of some adipogenic markers significantly. Mesenchymal stem cells are sensitive and responsive to mechanical loads, but debilitating conditions such as aging or obesity may steer mesenchymal stem cells toward adipogenesis. Here, daily application of low-intensity vibration signals partially neutralized the effects of adipogenic induction on mesenchymal stem cells, suggesting that these signals may provide an alternative and/or complementary option to reduce fat deposition.
为了解脂肪生成过程中骨髓间充质干细胞对机械信号的分子、形态和超微结构适应性，将定向分化为脂肪细胞的骨髓间充质干细胞每天暴露于高频低强度机械振动中。将D1-ORL-UVA小鼠骨髓间充质干细胞分别在生长培养基或脂肪生成培养基中培养1周。一组脂肪生成细胞施加低强度振动信号（每天15分钟，90赫兹，0.1克），另一组脂肪生成细胞作为假对照。通过MTT、油红O染色、鬼笔环肽染色和原子力显微镜测定细胞活力、脂质积累、超微结构和形态。半定量逆转录聚合酶链反应显示了负责脂肪生成的基因表达谱和细胞超微结构。低强度振动信号增加了脂肪生成培养中细胞的活力，与静止对照相比，细胞活力显著降低。低强度振动信号还使脂肪生成条件对细胞形态的影响正常化，包括面积、周长、圆度和肌动蛋白细胞骨架。此外，低强度振动信号显著降低了一些脂肪生成标志物的表达。间充质干细胞对机械负荷敏感且有反应，但衰老或肥胖等衰弱状况可能会使间充质干细胞向脂肪生成方向发展。在此，每天施加低强度振动信号可部分抵消脂肪生成诱导对间充质干细胞的影响，表明这些信号可能为减少脂肪沉积提供一种替代和/或补充选择。
