THE EFFECTS OF VIBRATION LOADING ON ADIPOSE STEM CELL VIABILITY, PROLIFERATION AND OSTEOGENIC DIFFERENTIATION
TIRKKONEN, LAURA (2010)
TIRKKONEN, LAURA
2010
Biokemia - Biochemistry
Lääketieteellinen tiedekunta - Faculty of Medicine
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Hyväksymispäivämäärä
2010-06-07
Julkaisun pysyvä osoite on
https://urn.fi/urn:nbn:fi:uta-1-20724
https://urn.fi/urn:nbn:fi:uta-1-20724
Tiivistelmä
Bone is a mechanosensitive tissue capable of adapting its mass and architecture according to the prevailing mechanical loading conditions. For example, high frequency vibration has been shown to increase bone formation in vivo and to enhance metabolism in human osteoblast-like cells in vitro. Therefore it was hypothesized that vibration loading could also stimulate differentiation of adipose stem cells (ASCs) toward osteogenic lineages. ASCs are mesenchymal stem cells (MSCs) capable of differentiating toward osteogenic, adipogenic, myogenic, and chondrogenic lineages in vitro, when treated with appropriate inducing factors. ASCs are under extensive research for the applications of bone tissue engineering. In this study, the effects of vibration loading were studied on human ASCs (hASCs) for the first time.
Human ASCs were cultured using either basic medium (BM) or osteogenic medium (OM) consisting of BM supplemented with 250 µM ascorbic acid 2-phosphate, 5 nM dexamethasone and 10 mM β-glycerophosphate. A specifically designed vibration loading device was used to stimulate hASCs with high frequency (50 and 100 Hz) and high magnitude (3 g) vibration for 3 h per day for 2 weeks, and the effects on attachment, viability, proliferation, alkaline phosphatase activity and mineralization were studied. Control cells were cultured similarly without vibration.
Viability of hASCs was not affected by the vibration loading, but it was observed that cells cultured in BM were detaching more easily under vibration than those cultured in OM. Osteogenic supplements may have increased the secretion of extracellular matrix (ECM) proteins enhancing the attachment of the cells. However, no significant differences were detected in proliferation of stimulated hASCs compared to control cells. In contrast, vibration loading increased ALP activity of hASCs significantly at 14 d time point by both frequencies when cultured in OM. Increase in mineralization was also seen in hASCs vibrated with 100 Hz (OM) at 14 d time point when compared to control.
In conclusion, the vibration loading device designed for this study was able to generate controlled vibrational forces to cells cultured on well plates. Osteogenic culturing conditions were found to be more optimal for vibration loading studies than basic conditions due to enhanced attachment of the cells. As a result, it was found that high magnitude, high frequency vibration combined with osteogenic culture conditions enhanced hASC differentiation towards osteogenic lineages.
Asiasanat:adipose stem cells, osteogenic differentiation, vibration loading
Human ASCs were cultured using either basic medium (BM) or osteogenic medium (OM) consisting of BM supplemented with 250 µM ascorbic acid 2-phosphate, 5 nM dexamethasone and 10 mM β-glycerophosphate. A specifically designed vibration loading device was used to stimulate hASCs with high frequency (50 and 100 Hz) and high magnitude (3 g) vibration for 3 h per day for 2 weeks, and the effects on attachment, viability, proliferation, alkaline phosphatase activity and mineralization were studied. Control cells were cultured similarly without vibration.
Viability of hASCs was not affected by the vibration loading, but it was observed that cells cultured in BM were detaching more easily under vibration than those cultured in OM. Osteogenic supplements may have increased the secretion of extracellular matrix (ECM) proteins enhancing the attachment of the cells. However, no significant differences were detected in proliferation of stimulated hASCs compared to control cells. In contrast, vibration loading increased ALP activity of hASCs significantly at 14 d time point by both frequencies when cultured in OM. Increase in mineralization was also seen in hASCs vibrated with 100 Hz (OM) at 14 d time point when compared to control.
In conclusion, the vibration loading device designed for this study was able to generate controlled vibrational forces to cells cultured on well plates. Osteogenic culturing conditions were found to be more optimal for vibration loading studies than basic conditions due to enhanced attachment of the cells. As a result, it was found that high magnitude, high frequency vibration combined with osteogenic culture conditions enhanced hASC differentiation towards osteogenic lineages.
Asiasanat:adipose stem cells, osteogenic differentiation, vibration loading