[Effect of actomyosin contractility on focal contacts of myofibroblasts and structure of stress fibers].
Myofibroblasts from rat lung were cultivated. These cells in addition to beta- and gamma-cytoplasmic actins, expressed alpha-smooth muscle actin (alpha-SMA) and formed a system of "supermature" focal contacts, which were connected with thick stress-fibers expressing alpha-SMA and myosin II. Reduction of actin-myison contractility by inhibitors BDM and ML-7 lead to stress fiber reorganization, e.g., decrease in their thickness, a selective disappearance of alpha-SMA expression and myosin translocation from bundles to the cytoplasm. Using immunofluorescence, interference-reflection microscopy and morphometry, we have demonstrated that an inhibition of actin-myosin contractility also leads to dispersion of myofibroblastic focal contacts. Phase-contrast and DIC video-enhanced microscopy of live cells showed morphological reorganization at the leading edge after inhibitory treatment. Thus, actin-myosin contractility controls the structure of "supermature" focal contacts of myofibroblasts and alpha-SMA expression in stress fibers.
Dugina
V B
VB
A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Russia.
Aleksandrova
A Iu
AIu
Gabbiani
G
G
Vasil'ev
Iu M
IuM
D000199:Actins / Q000502:physiology; D001381:Azepines / Q000494:pharmacology; D002478:Cells, Cultured; D003931:Diacetyl / Q000031:analogs & derivatives* / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005347:Fibroblasts / Q000502:physiology / Q000648:ultrastructure*; D022001:Focal Adhesions / Q000648:ultrastructure*; D008168:Lung / Q000166:cytology; D018715:Microscopy, Video; D024462:Myosin Type II / Q000502:physiology; D009219:Myosin-Light-Chain Kinase / Q000037:antagonists & inhibitors; D009281:Naphthalenes / Q000494:pharmacology; D022502:Stress Fibers / Q000648:ultrastructure*
D000199:Actins; D001381:Azepines; D004791:Enzyme Inhibitors; D009281:Naphthalenes; C070571:ML 7; C004717:diacetylmonoxime; D009219:Myosin-Light-Chain Kinase; D024462:Myosin Type II; D003931:Diacetyl