Dynamic reorientation of cultured cells and stress fibers under mechanical stress from periodic stretching.
Cell lines derived from rat aorta and frog kidney were cultured on elastic membrane, and mechanical stress was given to the cells by stretching the membrane periodically. Cell reorientation oblique to the direction of stretching occurred as a result of the rapid withdrawal of cell periphery located along the direction of stretching and gradual extension of the cell membrane toward the direction oblique to the direction of stretching. Dynamic reorganization of stress fibers in living cells was visualized by labeling stress fibers with TRITC(3)-actin or EGFP-tagged moesin fragments with actin-binding ability. Stress fibers aligned in the direction of stretching disappeared soon after the start of stretching and then obliquely reoriented stress fibers appeared. The stretch-induced reorientation of cultured cells was suppressed by an inhibitor of stretch-activated (SA) cation channels and by a Ca(2+) chelator. However, the rearrangement of stress fibers was not affected by these agents. From these results, we suggest that Ca(2+) influx via SA channels is involved in stretch-induced cell reorientation but stress fiber rearrangement is independent of SA channels. Therefore, cell reorientation does not simply depend on the arrangement of stress fibers but may be controlled by some additional mechanism(s) which is regulated by calcium signaling.
Hayakawa
K
K
Department of Biology, Chiba University, Yayoi-cho, Chiba 263-8522, Japan.
Sato
N
N
Obinata
T
T
D000199:Actins / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology; D002460:Cell Line; D002462:Cell Membrane / Q000502:physiology; D002614:Chelating Agents / Q000494:pharmacology; D005456:Fluorescent Dyes; D005682:Gadolinium / Q000494:pharmacology; D007473:Ion Channels / Q000378:metabolism; D007668:Kidney / Q000166:cytology* / Q000502:physiology; D008567:Membranes, Artificial; D008840:Microfilament Proteins / Q000378:metabolism; D008845:Microinjections; D009131:Muscle, Smooth, Vascular / Q000166:cytology* / Q000378:metabolism; D010507:Periodicity; D051381:Rats; D012235:Rhodamines / Q000737:chemistry; D022502:Stress Fibers / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure*; D013314:Stress, Mechanical; D014982:Xenopus laevis
D000199:Actins; D002614:Chelating Agents; D005456:Fluorescent Dyes; D007473:Ion Channels; D008567:Membranes, Artificial; D008840:Microfilament Proteins; D012235:Rhodamines; C071058:moesin; C009434:tetramethylrhodamine isothiocyanate; D005682:Gadolinium