title: Transient receptor potential vanilloid 2-mediated shear-stress responses in C2C12 myoblasts are regulated by serum and extracellular matrix.
abstract: The developmental sensitivity of skeletal muscle to mechanical forces is unparalleled in other tissues. Calcium entry via reputedly mechanosensitive transient receptor potential (TRP) channel classes has been shown to play an essential role in both the early proliferative stage and subsequent differentiation of skeletal muscle myoblasts, particularly TRP canonical (TRPC) 1 and TRP vanilloid (TRPV) 2. Here we show that C2C12 murine myoblasts respond to fluid flow-induced shear stress with increments in cytosolic calcium that are largely initiated by the mechanosensitive opening of TRPV2 channels. Response to fluid flow was augmented by growth in low extracellular serum concentration (5 vs. 20% fetal bovine serum) by greater than 9-fold and at 18 h in culture, coincident with the greatest TRPV2 channel expression under identical conditions (P < 0.02). Fluid flow responses were also enhanced by substrate functionalization with laminin, rather than with fibronectin, agreeing with previous findings that the gating of TRPV2 is facilitated by laminin. Fluid flow-induced calcium increments were blocked by ruthenium red (27%) and SKF-96365 (38%), whereas they were unaltered by 2-aminoethoxydiphenyl borate, further corroborating that TRPV2 channels play a predominant role in fluid flow mechanosensitivity over that of TRPC1 and TRP melastatin (TRPM) 7.
authors.affiliation: *Department of Biosystems and Science Engineering and Institute for Biomechanics, Eidgenössische Technische Hochschule Zürich, Switzerland; Department of Surgery, Yong Loo Lin School of Medicine, and Department of Physiology, National University of Singapore, Singapore; and National University Hospital Sports Centre, Singapore.
authors.forename: Felix
authors.initials: F
authors.lastname: Kurth
authors.affiliation: *Department of Biosystems and Science Engineering and Institute for Biomechanics, Eidgenössische Technische Hochschule Zürich, Switzerland; Department of Surgery, Yong Loo Lin School of Medicine, and Department of Physiology, National University of Singapore, Singapore; and National University Hospital Sports Centre, Singapore suraf@nus.edu.sg petra.dittrich@bsse.ethz.ch.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Franco-Obregón
authors.affiliation: *Department of Biosystems and Science Engineering and Institute for Biomechanics, Eidgenössische Technische Hochschule Zürich, Switzerland; Department of Surgery, Yong Loo Lin School of Medicine, and Department of Physiology, National University of Singapore, Singapore; and National University Hospital Sports Centre, Singapore.
authors.forename: Marco
authors.initials: M
authors.lastname: Casarosa
authors.affiliation: *Department of Biosystems and Science Engineering and Institute for Biomechanics, Eidgenössische Technische Hochschule Zürich, Switzerland; Department of Surgery, Yong Loo Lin School of Medicine, and Department of Physiology, National University of Singapore, Singapore; and National University Hospital Sports Centre, Singapore.
authors.forename: Simon K
authors.initials: SK
authors.lastname: Küster
authors.affiliation: *Department of Biosystems and Science Engineering and Institute for Biomechanics, Eidgenössische Technische Hochschule Zürich, Switzerland; Department of Surgery, Yong Loo Lin School of Medicine, and Department of Physiology, National University of Singapore, Singapore; and National University Hospital Sports Centre, Singapore.
authors.forename: Karin
authors.initials: K
authors.lastname: Wuertz-Kozak
authors.affiliation: *Department of Biosystems and Science Engineering and Institute for Biomechanics, Eidgenössische Technische Hochschule Zürich, Switzerland; Department of Surgery, Yong Loo Lin School of Medicine, and Department of Physiology, National University of Singapore, Singapore; and National University Hospital Sports Centre, Singapore suraf@nus.edu.sg petra.dittrich@bsse.ethz.ch.
authors.forename: Petra S
authors.initials: PS
authors.lastname: Dittrich
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000096:biosynthesis* / Q000235:genetics; D002417:Cattle; D002460:Cell Line; D005109:Extracellular Matrix / Q000378:metabolism*; D005353:Fibronectins / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D007093:Imidazoles / Q000494:pharmacology; D015640:Ion Channel Gating; D007797:Laminin / Q000378:metabolism; D040542:Mechanotransduction, Cellular; D051379:Mice; D032446:Myoblasts / Q000166:cytology / Q000378:metabolism*; D012430:Ruthenium Red / Q000494:pharmacology; D044967:Serum / Q000378:metabolism; D013312:Stress, Physiological; D050052:TRPC Cation Channels / Q000096:biosynthesis; D050053:TRPM Cation Channels / Q000096:biosynthesis; D050916:TRPV Cation Channels / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D015220:Calcium Channels; D005353:Fibronectins; D007093:Imidazoles; D007797:Laminin; D050052:TRPC Cation Channels; D050053:TRPM Cation Channels; D050916:TRPV Cation Channels; C485717:Trpv2 protein, mouse; C096351:transient receptor potential cation channel, subfamily C, member 1; D012430:Ruthenium Red; C421903:Trpm7 protein, mouse; C063159:1-(2-(3-(4-methoxyphenyl)propoxy)-4-methoxyphenylethyl)-1H-imidazole; D002118:Calcium
keywords: calcium; laminin; mechanotransduction; microfluidics; myogenesis