Rho A and the Rho kinase pathway regulate fibroblast contraction: Enhanced contraction in constitutively active Rho A fibroblast cells

• Published in: Biochemical and biophysical research communications 2010-08, Vol.399 (2), p.292-299
• Main Authors: Nobe, Koji, Nobe, Hiromi, Yoshida, Hiroko, Kolodney, Michael S., Paul, Richard J., Honda, Kazuo
• Format: Article
• Language: English
• Subjects: 60 APPLIED LIFE SCIENCES; Animals; CALVES; CELL PROLIFERATION; COLLAGEN; CONTRACTION; FIBERS; Fibroblast; FIBROBLASTS; Fibroblasts - enzymology; Fibroblasts - physiology; HEALING; Isometric Contraction; Mice; NIH 3T3 Cells; Rho A; Rho kinase; rho-Associated Kinases - metabolism; rhoA GTP-Binding Protein - metabolism; TRANSLOCATION; Wound Healing; WOUNDS
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2010.07.074

► Mechanisms of fibroblast cell contraction in collagen matrix. ► Assessed an isometric force development using 3D-reconstituted-fibroblast fiber. ► Constitutively active Rho A induced the over-contraction of fibroblast cells. ► Rho A and Rho kinase pathway has a central role in fibroblast cell contraction. 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.