TY - JOUR
T1 - The effect of equiaxial stretching on the osteogenic differentiation and mechanical properties of human adipose stem cells
AU - Virjula, Sanni
AU - Zhao, Feihu
AU - Leivo, Joni
AU - Vanhatupa, Sari
AU - Kreutzer, Joose
AU - Vaughan, Ted J.
AU - Honkala, Anna Maija
AU - Viehrig, Marlitt
AU - Mullen, Conleth A.
AU - Kallio, Pasi
AU - McNamara, Laoise M.
AU - Miettinen, Susanna
N1 - EXT="Zhao, Feihu", INT=tut-bmt,”Viehrig, Marlitt”
PY - 2017
Y1 - 2017
N2 - Although mechanical cues are known to affect stem cell fate and mechanobiology, the significance of such stimuli on the osteogenic differentiation of human adipose stem cells (hASCs) remains unclear. In this study, we investigated the effect of long-term mechanical stimulation on the attachment, osteogenic differentiation and mechanical properties of hASCs. Tailor-made, pneumatic cell stretching devices were used to expose hASCs to cyclic equiaxial stretching in osteogenic medium. Cell attachment and focal adhesions were visualised using immunocytochemical vinculin staining on days 3 and 6, and the proliferation and alkaline phosphatase activity, as a sign of early osteogenic differentiation, were analysed on days 0, 6 and 10. Furthermore, the mechanical properties of hASCs, in terms of apparent Young's modulus and normalised contractility, were obtained using a combination of atomic force microscopy based indentation and computational approaches. Our results indicated that cyclic equiaxial stretching delayed proliferation and promoted osteogenic differentiation of hASCs. Stretching also reduced cell size and intensified focal adhesions and actin cytoskeleton. Moreover, cell stiffening was observed during osteogenic differentiation and especially under mechanical stimulation. These results suggest that cyclic equiaxial stretching modifies cell morphology, focal adhesion formation and mechanical properties of hASCs. This could be exploited to enhance osteogenic differentiation.
AB - Although mechanical cues are known to affect stem cell fate and mechanobiology, the significance of such stimuli on the osteogenic differentiation of human adipose stem cells (hASCs) remains unclear. In this study, we investigated the effect of long-term mechanical stimulation on the attachment, osteogenic differentiation and mechanical properties of hASCs. Tailor-made, pneumatic cell stretching devices were used to expose hASCs to cyclic equiaxial stretching in osteogenic medium. Cell attachment and focal adhesions were visualised using immunocytochemical vinculin staining on days 3 and 6, and the proliferation and alkaline phosphatase activity, as a sign of early osteogenic differentiation, were analysed on days 0, 6 and 10. Furthermore, the mechanical properties of hASCs, in terms of apparent Young's modulus and normalised contractility, were obtained using a combination of atomic force microscopy based indentation and computational approaches. Our results indicated that cyclic equiaxial stretching delayed proliferation and promoted osteogenic differentiation of hASCs. Stretching also reduced cell size and intensified focal adhesions and actin cytoskeleton. Moreover, cell stiffening was observed during osteogenic differentiation and especially under mechanical stimulation. These results suggest that cyclic equiaxial stretching modifies cell morphology, focal adhesion formation and mechanical properties of hASCs. This could be exploited to enhance osteogenic differentiation.
KW - Atomic force microscopy indentation
KW - Dynamic cell culture
KW - Mechanical stimulation
KW - Mesenchymal stem cell
KW - PDMS
KW - mechanobiology
KW - Atomic force microscopy indentation
KW - Dynamic cell culture
KW - Mechanical stimulation
KW - Mesenchymal stem cell
KW - PDMS
KW - mechanobiology
U2 - 10.1016/j.jmbbm.2017.04.016
DO - 10.1016/j.jmbbm.2017.04.016
M3 - Article
AN - SCOPUS:85018593351
SN - 1751-6161
VL - 72
SP - 38
EP - 48
JO - Journal of the Mechanical Behavior of Biomedical Materials
JF - Journal of the Mechanical Behavior of Biomedical Materials
IS - 72
ER -