title: Absence of K-Ras Reduces Proliferation and Migration But Increases Extracellular Matrix Synthesis in Fibroblasts.
abstract: The involvement of Ras-GTPases in the development of renal fibrosis has been addressed in the last decade. We have previously shown that H- and N-Ras isoforms participate in the regulation of fibrosis. Herein, we assessed the role of K-Ras in cellular processes involved in the development of fibrosis: proliferation, migration, and extracellular matrix (ECM) proteins synthesis. K-Ras knockout (KO) mouse embryonic fibroblasts (K-ras(-/-) ) stimulated with transforming growth factor-β1 (TGF-β1) exhibited reduced proliferation and impaired mobility than wild-type fibroblasts. Moreover, an increase on ECM production was observed in K-Ras KO fibroblasts in basal conditions. The absence of K-Ras was accompanied by reduced Ras activation and ERK phosphorylation, and increased AKT phosphorylation, but no differences were observed in TGF-β1-induced Smad signaling. The MEK inhibitor U0126 decreased cell proliferation independently of the presence of K-ras but reduced migration and ECM proteins expression only in wild-type fibroblasts, while the PI3K-AKT inhibitor LY294002 decreased cell proliferation, migration, and ECM synthesis in both types of fibroblasts. Thus, our data unveil that K-Ras and its downstream effector pathways distinctively regulate key biological processes in the development of fibrosis. Moreover, we show that K-Ras may be a crucial mediator in TGF-β1-mediated effects in this cell type. J. Cell. Physiol. 231: 2224-2235, 2016. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Unidad de Fisiopatología Renal y Cardiovascular, Departamento de Fisiología y Farmacología, Instituto "Reina Sofía" de Investigación Nefrológica, Universidad de Salamanca, Salamanca, Spain.|Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain.
authors.forename: José M
authors.initials: JM
authors.lastname: Muñoz-Félix
authors.affiliation: Unidad de Fisiopatología Renal y Cardiovascular, Departamento de Fisiología y Farmacología, Instituto "Reina Sofía" de Investigación Nefrológica, Universidad de Salamanca, Salamanca, Spain.|Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain.
authors.forename: Isabel
authors.initials: I
authors.lastname: Fuentes-Calvo
authors.affiliation: Unidad de Fisiopatología Renal y Cardiovascular, Departamento de Fisiología y Farmacología, Instituto "Reina Sofía" de Investigación Nefrológica, Universidad de Salamanca, Salamanca, Spain.|Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Cuesta
authors.affiliation: Unidad de Fisiopatología Renal y Cardiovascular, Departamento de Fisiología y Farmacología, Instituto "Reina Sofía" de Investigación Nefrológica, Universidad de Salamanca, Salamanca, Spain.|Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain.
authors.forename: Nélida
authors.initials: N
authors.lastname: Eleno
authors.affiliation: Facultad de Medicina, Departamento de Biología Molecular, Instituto de Biomedicina y Biotecnología de Cantabria, Consejo Superior de Investigaciones Científicas-IDICAN-Universidad de Cantabria, Santander, Spain.
authors.forename: Piero
authors.initials: P
authors.lastname: Crespo
authors.affiliation: Unidad de Fisiopatología Renal y Cardiovascular, Departamento de Fisiología y Farmacología, Instituto "Reina Sofía" de Investigación Nefrológica, Universidad de Salamanca, Salamanca, Spain.|Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain.
authors.forename: José M
authors.initials: JM
authors.lastname: López-Novoa
authors.affiliation: Unidad de Fisiopatología Renal y Cardiovascular, Departamento de Fisiología y Farmacología, Instituto "Reina Sofía" de Investigación Nefrológica, Universidad de Salamanca, Salamanca, Spain.|Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain.|Instituto de Estudios de Ciencias de la Salud de Castilla y León (IECSCYL), Unidad de Investigación, Hospital Universitario de Salamanca, Salamanca, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Martínez-Salgado
mesh_terms: D000818:Animals; D002070:Butadienes / Q000494:pharmacology; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D005109:Extracellular Matrix / Q000378:metabolism*; D016326:Extracellular Matrix Proteins / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism*; D005353:Fibronectins / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D009570:Nitriles / Q000494:pharmacology; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010766:Phosphorylation; D016283:Proto-Oncogene Proteins p21(ras) / Q000172:deficiency / Q000378:metabolism*; D015398:Signal Transduction; D053773:Transforming Growth Factor beta1 / Q000378:metabolism
chemical_list: D002070:Butadienes; D016326:Extracellular Matrix Proteins; D005353:Fibronectins; D009570:Nitriles; D019869:Phosphatidylinositol 3-Kinases; D016283:Proto-Oncogene Proteins p21(ras); D053773:Transforming Growth Factor beta1; C113580:U 0126; C495971:Hras protein, mouse