title: Cyclic force upregulates mechano-growth factor and elevates cell proliferation in 3D cultured skeletal myoblasts.
abstract: Mechano-growth factor (MGF), the insulin growth factor- I (IGF-I) splice variant, has drawn an increasing attention in recent years. In this study, using a newly established system, we three-dimensionally (3D) cultured rat skeletal myoblasts and loaded them with cyclic uniaxial tensile strain of different magnitudes or time duration. After that, the cell proliferative index (PI) and mRNA expression of MGF, IGF-IEa and integrin beta1 were assayed. The major findings are: (1) mechanical stimulation induced MGF upregulation commensurate with cell PI elevation both in the 3D and 2D cultured myoblasts, but stronger mechanical force was needed to activate MGF expression in the 3D cultures; (2) MGF but not IGF-IEa was essential for mechano-induced myoblast replication, as IGF-IEa upregulation lagged cell PI elevation; and (3) the time course upregulation of MGF and integrin beta1 was correlated with each other, suggesting they shared a common mechanotransduction pathway.
authors.affiliation: State Key Laboratory of Oral Diseases, West China Stomatology Hospital, Sichuan University, Chengdu, PR China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Li
authors.forename: Zhihe
authors.initials: Z
authors.lastname: Zhao
authors.forename: Jinlin
authors.initials: J
authors.lastname: Song
authors.forename: Yang
authors.initials: Y
authors.lastname: Feng
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Li
authors.forename: Yurong
authors.initials: Y
authors.lastname: Liu
authors.forename: Pu
authors.initials: P
authors.lastname: Yang
mesh_terms: D000818:Animals; D001483:Base Sequence; D001696:Biomechanical Phenomena; D018929:Cell Culture Techniques; D049109:Cell Proliferation; D002478:Cells, Cultured; D017931:DNA Primers / Q000235:genetics; D007334:Insulin-Like Growth Factor I / Q000235:genetics*; D019012:Integrin beta1 / Q000235:genetics; D032448:Myoblasts, Skeletal / Q000166:cytology* / Q000502:physiology*; D020033:Protein Isoforms / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D013314:Stress, Mechanical; D015854:Up-Regulation
chemical_list: D017931:DNA Primers; D019012:Integrin beta1; D020033:Protein Isoforms; D012333:RNA, Messenger; C519382:mechano-growth factor, rat; D007334:Insulin-Like Growth Factor I