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Mechanically Stretching Microvascular Smooth Muscle Cells (VSMC) Induces Three‐dimensional Reorganization of Vinculin in Focal Adhesions
Author(s) -
Sun Zhe,
Li Zhaohui,
Huang Shaoxing,
Meininger Gerald A.
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.965.2
Subject(s) - vinculin , focal adhesion , mechanotransduction , extracellular matrix , biophysics , chemistry , adhesion , confocal microscopy , actin , cell adhesion , confocal , cytoskeleton , microbiology and biotechnology , cell , anatomy , biology , biochemistry , optics , physics , organic chemistry
Focal adhesions (FA) are hypothesized to mediate cell mechanotransduction by forming a conduit linking the cytoskeleton with extracellular matrix. This enables transmission of force and biochemical signals across the cell membrane. In order to gain insight into the nature of force transmission within and across the cell, a hybrid system combining confocal and atomic force microscopy (AFM) was used to apply pulling force on the apical cell surface while simultaneously monitoring FA changes at the cell substrate interface. VSMCs were isolated from rat skeletal muscle arterioles (70~100 μm Dia), and were transfected with GFP‐tagged vinculin. The tips of AFM probes were fused with a FN‐coated 5 μm bead. The bead was placed on the VSMC surface (20 min) to form an integrin‐mediated cell adhesion. Controlled pulling force was applied through the bead adhesion site by AFM and the GFP‐vinculin signal at FAs was recorded in time‐lapse by confocal microscopy. Collectively, FAs on any given cell were found to either increase, decrease or remain unchanged in size in response to the AFM pulling force. Also, the directionality of FA movement varied with respect to the site of AFM pulling. These data suggests the transmission of force from the apical surface to the lower cell surface is complex. Further analyses will require knowledge of actin distribution and the forces experienced at individual FA sites. (Supported by NIH HL‐062863 to GAM)