title: Cyclic strain dominates over microtopography in regulating cytoskeletal and focal adhesion remodeling of human mesenchymal stem cells.
abstract: Human bone marrow-derived mesenchymal stem cell (hMSCs) function depends on chemical factors and also on the physical cues of the microenvironmental niche. Here, this physical microenvironment is recapitulated with controlled modes of mechanical strain applied to substrata containing three-dimensional features in order to analyze the effects on cell morphology, focal adhesion distribution, and gene expression. Ten percentage of strain at 1 Hz is delivered for 48 h to hMSCs cultured on flat surfaces, or on substrata with 15 μm-high microtopographic posts spaced 75 μm apart. Adding strain to microtopography produced stable semicircular focal adhesions, and actin spanning from post to post. Strain dominated over microtopography for expression of genes for the cytoskeleton (caldesmon-1 and calponin 3), cell adhesion (integrin-α2, vinculin, and paxillin), and extracellular matrix remodeling (MMP13) (p<0.05). Overall, attention to external mechanical stimuli is necessary for optimizing the stem cell niche for regenerative medicine.
authors.affiliation: Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60612, USA.
authors.forename: Golnar
authors.initials: G
authors.lastname: Doroudian
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Curtis
authors.forename: Anjulie
authors.initials: A
authors.lastname: Gang
authors.forename: Brenda
authors.initials: B
authors.lastname: Russell
mesh_terms: D002135:Calcium-Binding Proteins / Q000235:genetics; D002148:Calmodulin-Binding Proteins / Q000235:genetics; D002478:Cells, Cultured; D003599:Cytoskeleton / Q000648:ultrastructure*; D022001:Focal Adhesions; D015870:Gene Expression; D006801:Humans; D055595:Mechanical Phenomena; D059630:Mesenchymal Stem Cells / Q000502:physiology* / Q000648:ultrastructure*; D008840:Microfilament Proteins / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D000096985:Calponins
chemical_list: D002135:Calcium-Binding Proteins; D002148:Calmodulin-Binding Proteins; D008840:Microfilament Proteins; D000096985:Calponins