title: Cyclic stretching of soft substrates induces spreading and growth.
abstract: In the body, soft tissues often undergo cycles of stretching and relaxation that may affect cell behaviour without changing matrix rigidity. To determine whether transient forces can substitute for a rigid matrix, we stretched soft pillar arrays. Surprisingly, 1-5% cyclic stretching over a frequency range of 0.01-10 Hz caused spreading and stress fibre formation (optimum 0.1 Hz) that persisted after 4 h of stretching. Similarly, stretching increased cell growth rates on soft pillars comparative to rigid substrates. Of possible factors linked to fibroblast growth, MRTF-A (myocardin-related transcription factor-A) moved to the nucleus in 2 h of cyclic stretching and reversed on cessation; but YAP (Yes-associated protein) moved much later. Knockdown of either MRTF-A or YAP blocked stretch-dependent growth. Thus, we suggest that the repeated pulling from a soft matrix can substitute for a stiff matrix in stimulating spreading, stress fibre formation and growth.
authors.affiliation: Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore.
authors.forename: Yidan
authors.initials: Y
authors.lastname: Cui
authors.affiliation: Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore.
authors.forename: Feroz M
authors.initials: FM
authors.lastname: Hameed
authors.affiliation: Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore.
authors.forename: Bo
authors.initials: B
authors.lastname: Yang
authors.affiliation: Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore.
authors.forename: Kyunghee
authors.initials: K
authors.lastname: Lee
authors.affiliation: Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore.
authors.forename: Catherine Qiurong
authors.initials: CQ
authors.lastname: Pan
authors.affiliation: 1] Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore [2] School of Mechanical Engineering and Department of Global Biomedical Engineering, Sungkyunkwan University, Suwon 440-746, Korea.
authors.forename: Sungsu
authors.initials: S
authors.lastname: Park
authors.affiliation: 1] Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore [2] Department of Biological Sciences, Columbia University, New York, New York 10027, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Sheetz
mesh_terms: D000818:Animals; D018929:Cell Culture Techniques; D048708:Cell Growth Processes; D048430:Cell Shape; D002478:Cells, Cultured; D005347:Fibroblasts / Q000166:cytology / Q000502:physiology*; D051379:Mice; D013314:Stress, Mechanical