title: Reorganization of cytoskeleton and transient activation of Ca2+ channels in mesenchymal stem cells cultured on silicon nanowire arrays.
abstract: Tissue engineering combines biological cells and synthetic materials containing chemical signaling molecules to form scaffolds for tissue regeneration. Mesenchymal stem cells (MSCs) provide an attractive source for tissue engineering due to their versatility of multipotent differentiation. Recently, it has been recognized that both chemical and mechanical stimulations are essential mediators of adhesion and differentiation of MSCs. While significant progress has been made on the understanding of chemical regulatory factors within the extracellular matrix, the effects of mechanical stimulation exerted by nanomaterials on MSCs and the underlying mechanisms are less well-known. The present study showed that the adhesion, proliferation, and differentiation of MSCs cultured on vertically aligned silicon nanowire (SiNW) arrays were significantly different from those on flat silicon wafer and control substrates. The interactions between MSCs and the SiNW arrays caused the stem cells to preferentially differentiate toward osteocytes and chondrocytes but not adipocytes in the absence of supplementary growth factors. Our study demonstrated that Ca(2+) ion channels were transiently activated in MSCs upon mechanical stimulation, which eventually led to activation of Ras/Raf/MEK/ERK signaling cascades to regulate adhesion, proliferation, and differentiation of MSCs. The stretch-mediated transient Ca(2+) ion channel activation and cytoskeleton reorganization during stem cell-nanowire interaction may be early events of lineage-specific potentiation of MSCs in determining the fates of mesenchymal stem cells cultured on microenvironments with specific mechanical properties.
authors.affiliation: Key Laboratory of Biochip Technology, Biotech and Health Centre, Shenzhen Research Institute of City University of Hong Kong , Shenzhen, China.
authors.forename: Dandan
authors.initials: D
authors.lastname: Liu
authors.forename: Changqing
authors.initials: C
authors.lastname: Yi
authors.forename: Kaiqun
authors.initials: K
authors.lastname: Wang
authors.forename: Chi-Chun
authors.initials: CC
authors.lastname: Fong
authors.forename: Zuankai
authors.initials: Z
authors.lastname: Wang
authors.forename: Pik Kwan
authors.initials: PK
authors.lastname: Lo
authors.forename: Dong
authors.initials: D
authors.lastname: Sun
authors.forename: Mengsu
authors.initials: M
authors.lastname: Yang
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology; D015220:Calcium Channels / Q000378:metabolism*; D018929:Cell Culture Techniques; D002454:Cell Differentiation; D002478:Cells, Cultured; D003599:Cytoskeleton / Q000378:metabolism*; D005260:Female; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism; D051379:Mice; D053770:Nanowires / Q000737:chemistry*; D052898:Optical Tweezers; D015398:Signal Transduction; D012825:Silicon / Q000737:chemistry*; D023822:Tissue Engineering
chemical_list: D015220:Calcium Channels; D012825:Silicon