Low-intensity vibrations normalize adipogenesis-induced morphological and molecular changes of adult mesenchymal stem cells

Abstract

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.

Influence of Low-Magnitude High-Frequency Vibration on Bone Cells and Bone Regeneration

“…To elucidate the effects of vibration, the cells were subjected to a specific vibration regime; however, loading parameters and time schedules varied among the studies (Table 1), but were within the range of 20-90 Hz and <1 g magnitude. It was demonstrated by the majority of studies, that LMHFV induced the expression (Marycz et al, 2016;Baskan et al, 2017). This finding appears to be consistent regardless of the MSC origin or the vibration setting or duration.…”

Mesenchymal Stem Cells: Cell Fate Decision to Osteoblast or Adipocyte and Application in Osteoporosis Treatment

“…In vitro studies have also been conducted to illustrate the effect of vibration on MSCs differentiation and the underlying molecular mechanism. Ozcivici’s group found that 1-week treatment (15 min/day) of LMHF (0.15 g, 90 Hz) vibration promoted osteoblastic differentiation and suppressed adipogenic differentiation of mouse BM-MSCs, showing a significant increase of runx2 and reduction of PPARγ and C/EBPα [ 89 , 90 ]. Chen et al also reported that 0.3 g acoustic vibration at 800 Hz (30 min/day) promoted osteogenic differentiation and suppressed adipogenic differentiation via upregulating runx2 expression and downregulating PPARγ [ 91 ].…”

A glance on the role of actin in osteogenic and adipogenic differentiation of mesenchymal stem cells

“…The exact mechanism underlying the vibration-induced differentiation is not yet clear, and further studies are required to explore this molecular phenomenon [78]. Low-intensity vibration leads to the disruption of actin fibers, which favors adipogenesis in MSC differentiation; however, the exact mechanism is not yet clear [79]. An ultrasound-based method, acoustic tweezing cytometry, also facilitates the formation and contractility of F-actin, which ultimately promotes Yes-associated protein (YAP) translocation, thereby favoring osteogenesis [80].…”