Rho A and the Rho kinase pathway regulate fibroblast contraction: Enhanced contraction in constitutively active Rho A fibroblast cells.
Fibroblast cells play a central role in the proliferation phase of wound healing processes, contributing to force development. The intracellular signaling pathways regulating this non-muscle contraction are only partially understood. To study the relations between Rho A and contractile responses, constitutively active Rho A (CA-Rho A) fibroblast cells were reconstituted into fibers and the effects of calf serum (CS) on isometric force were studied. CS-induced force in CA-Rho A fibroblast fibers was twice as large as that in wild type (NIH 3T3) fibroblast fibers. During this response, the translocation of Rho A from the cytosol to the membrane was detected by Rho A activity assays and Western blot analysis. Pre-treatment with a Rho specific inhibitor (C3-exoenzyme) suppressed translocation as well as contraction. These results indicate that Rho A activation is essential for fibroblast contraction. The Rho kinase inhibitor (Y27632) inhibited both NIH 3T3 and CA-Rho A fibroblast fiber contractions. Activation of Rho A is thus directly coupled with Rho kinase activity. We conclude that the translocation of Rho A from the cytosol to the membrane and the Rho kinase pathway can regulate wound healing processes mediated by fibroblast contraction.
Nobe
Koji
K
Department of Pharmacology, School of Pharmaceutical Sciences, Showa University, Tokyo, Japan. kojinobe@pharm.showa-u.ac.jp
Nobe
Hiromi
H
Yoshida
Hiroko
H
Kolodney
Michael S
MS
Paul
Richard J
RJ
Honda
Kazuo
K
D000818:Animals; D005347:Fibroblasts / Q000201:enzymology / Q000502:physiology*; D007537:Isometric Contraction; D051379:Mice; D041681:NIH 3T3 Cells; D014945:Wound Healing; D054460:rho-Associated Kinases / Q000378:metabolism*; D020742:rhoA GTP-Binding Protein / Q000378:metabolism*
D054460:rho-Associated Kinases; D020742:rhoA GTP-Binding Protein