title: Spatial and temporal traction response in human airway smooth muscle cells.
abstract: Tractions that cells exert on their substrates are essential in cell spreading, migration, and contraction. These tractions can be determined by plating the cells on a flexible gel and measuring the deformation of the gel by using fluorescent beads embedded just below the surface of the gel. In this article we describe the image correlation method (ICM) optimized for determining the displacement field of the gel under a contracting cell. For the calculation of the traction field from the displacement field we use the recently developed method of Fourier transform traction cytometry (FTTC). The ICM and FTTC methods are applied to human airway smooth muscle cells during stimulation with the contractile agonist histamine or the relaxing agonist isoproterenol. The overall intensity of the cell contraction (the median traction magnitude, the energy transferred from the cell to the gel, and the net contractile moment) increased after activation with histamine, and decreased after treatment with isoproterenol. Cells exhibited regional differences in the time course of traction during the treatment. Both temporal evolution and magnitude of traction increase induced by histamine varied markedly among different cell protrusions, whereas the nuclear region showed the smallest response. These results suggest that intracellular mediators of cell adhesion and contraction respond to contractile stimuli with different rates and intensities in different regions of the cell.
authors.affiliation: Physiology Program, Harvard School of Public Health, Boston, MA 02115, USA. tolic@nbi.dk
authors.forename: Iva Marija
authors.initials: IM
authors.lastname: Tolić-Nørrelykke
authors.forename: James P
authors.initials: JP
authors.lastname: Butler
authors.forename: Jianxin
authors.initials: J
authors.lastname: Chen
authors.forename: Ning
authors.initials: N
authors.lastname: Wang
mesh_terms: D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D002448:Cell Adhesion / Q000502:physiology; D002478:Cells, Cultured; D003599:Cytoskeleton / Q000187:drug effects / Q000502:physiology; D004734:Energy Metabolism; D005456:Fluorescent Dyes; D005583:Fourier Analysis; D005782:Gels; D006632:Histamine / Q000494:pharmacology; D006801:Humans; D019044:Image Cytometry / Q000379:methods; D007089:Image Enhancement; D007545:Isoproterenol / Q000494:pharmacology; D008863:Microspheres; D009010:Monte Carlo Method; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology*; D009130:Muscle, Smooth / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D013314:Stress, Mechanical; D014132:Trachea / Q000166:cytology*
chemical_list: D000318:Adrenergic beta-Agonists; D005456:Fluorescent Dyes; D005782:Gels; D006632:Histamine; D007545:Isoproterenol