RhoA Ambivalently Controls Prominent Myofibroblast Characteritics by Involving Distinct Signaling Routes

• Published in: PloS one Vol. 10; no. 10; p. e0137519
• Main Authors: Jatho, Aline, Hartmann, Svenja, Kittana, Naim, Mügge, Felicitas, Wuertz, Christina M, Tiburcy, Malte, Zimmermann, Wolfram-Hubertus, Katschinski, Dörthe M, Lutz, Susanne
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 08.10.2015; Public Library of Science (PLoS)
• Subjects: Acetylation; Actin; Analysis; Animals; Bone morphogenetic proteins; Cancer; Cardiomyocytes; Cardiovascular disease; Cascades; Cell adhesion & migration; Cell growth; Cell Movement - genetics; Cell Movement - physiology; Cell Survival - genetics; Cell Survival - physiology; Cells, Cultured - physiology; Collagen; Connective tissue growth factor; Coronary artery disease; Cytoskeleton; Environmental conditions; Fibroblasts; Fibrosis; Gene expression; Growth factors; Heart; Heart diseases; Immunoglobulins; Kinases; Migration; Muscle contraction; Muscle proteins; Myofibroblasts - metabolism; Pharmacology; Phenotypes; Physiological aspects; Physiology; Polymerase Chain Reaction; Proteins; Rats; Rho-associated kinase; rhoA GTP-Binding Protein - genetics; rhoA GTP-Binding Protein - metabolism; RhoA protein; Signal Transduction - physiology; Signaling; Smooth muscle; Three dimensional models; Transforming growth factors; Tubulin; Viscoelasticity; United Kingdom; Germany
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0137519

RhoA has been shown to be beneficial in cardiac disease models when overexpressed in cardiomyocytes, whereas its role in cardiac fibroblasts (CF) is still poorly understood. During cardiac remodeling CF undergo a transition towards a myofibroblast phenotype thereby showing an increased proliferation and migration rate. Both processes involve the remodeling of the cytoskeleton. Since RhoA is known to be a major regulator of the cytoskeleton, we analyzed its role in CF and its effect on myofibroblast characteristics in 2 D and 3D models. Downregulation of RhoA was shown to strongly affect the actin cytoskeleton. It decreased the myofibroblast marker α-sm-actin, but increased certain fibrosis-associated factors like TGF-β and collagens. Also, the detailed analysis of CTGF expression demonstrated that the outcome of RhoA signaling strongly depends on the involved stimulus. Furthermore, we show that proliferation of myofibroblasts rely on RhoA and tubulin acetylation. In assays accessing three different types of migration, we demonstrate that RhoA/ROCK/Dia1 are important for 2D migration and the repression of RhoA and Dia1 signaling accelerates 3D migration. Finally, we show that a downregulation of RhoA in CF impacts the viscoelastic and contractile properties of engineered tissues. RhoA positively and negatively influences myofibroblast characteristics by differential signaling cascades and depending on environmental conditions. These include gene expression, migration and proliferation. Reduction of RhoA leads to an increased viscoelasticity and a decrease in contractile force in engineered cardiac tissue.