title: Defining the role of syndecan-4 in mechanotransduction using surface-modification approaches.
abstract: The ability of cells to respond to external mechanical stimulation is a complex and robust process involving a diversity of molecular interactions. Although mechanotransduction has been heavily studied, many questions remain regarding the link between physical stimulation and biochemical response. Of significant interest has been the contribution of the transmembrane proteins involved, and integrins in particular, because of their connectivity to both the extracellular matrix and the cytoskeleton. Here, we demonstrate the existence of a mechanically based initiation molecule, syndecan-4. We first demonstrate the ability of syndecan-4 molecules to support cell attachment and spreading without the direct extracellular binding of integrins. We also examine the distribution of focal adhesion-associated proteins through controlling surface interactions of beads with molecular specificity in binding to living cells. Furthermore, after adhering cells to elastomeric membranes via syndecan-4-specific attachments we mechanically strained the cells via our mechanical stimulation and polymer surface chemical modification approach. We found ERK phosphorylation similar to that shown for mechanotransductive response for integrin-based cell attachments through our elastomeric membrane-based approach and optical magnetic twisting cytometry for syndecan-4. Finally, through the use of cytoskeletal disruption agents, this mechanical signaling was shown to be actin cytoskeleton dependent. We believe that these results will be of interest to a wide range of fields, including mechanotransduction, syndecan biology, and cell-material interactions.
authors.affiliation: Department of Biology, College of the Holy Cross, 1 College Street, Worcester, MA 01610, USA. rbellin@holycross.edu
authors.forename: Robert M
authors.initials: RM
authors.lastname: Bellin
authors.forename: James D
authors.initials: JD
authors.lastname: Kubicek
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Frigault
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Kamien
authors.forename: Robert L
authors.initials: RL
authors.lastname: Steward
authors.forename: Hillary M
authors.initials: HM
authors.lastname: Barnes
authors.forename: Michael B
authors.initials: MB
authors.lastname: Digiacomo
authors.forename: Luke J
authors.initials: LJ
authors.lastname: Duncan
authors.forename: Christina K
authors.initials: CK
authors.lastname: Edgerly
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Morse
authors.forename: Chan Young
authors.initials: CY
authors.lastname: Park
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Fredberg
authors.forename: Chao-Min
authors.initials: CM
authors.lastname: Cheng
authors.forename: Philip R
authors.initials: PR
authors.lastname: LeDuc
mesh_terms: D000818:Animals; D000906:Antibodies; D057005:Bioengineering; D001696:Biomechanical Phenomena; D002448:Cell Adhesion / Q000187:drug effects / Q000502:physiology; D005353:Fibronectins / Q000502:physiology; D016023:Integrins / Q000502:physiology; D020935:MAP Kinase Signaling System; D040542:Mechanotransduction, Cellular / Q000187:drug effects / Q000502:physiology*; D051379:Mice; D008954:Models, Biological; D041681:NIH 3T3 Cells; D011485:Protein Binding; D013499:Surface Properties; D053671:Syndecan-4 / Q000037:antagonists & inhibitors / Q000276:immunology / Q000502:physiology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D000906:Antibodies; D005353:Fibronectins; D016023:Integrins; C508306:Sdc4 protein, mouse; D053671:Syndecan-4; D013755:Tetradecanoylphorbol Acetate