title: Expression of type I collagen and tenascin C is regulated by actin polymerization through MRTF in dedifferentiated chondrocytes.
abstract: This study examined actin regulation of fibroblast matrix genes in dedifferentiated chondrocytes. We demonstrated that dedifferentiated chondrocytes exhibit increased actin polymerization, nuclear localization of myocardin related transcription factor (MRTF), increased type I collagen (col1) and tenascin C (Tnc) gene expression, and decreased Sox9 gene expression. Induction of actin depolymerization by latrunculin treatment or cell rounding, reduced MRTF nuclear localization, repressed col1 and Tnc expression, and increased Sox9 gene expression in dedifferentiated chondrocytes. Treatment of passaged chondrocytes with MRTF inhibitor repressed col1 and Tnc expression, but did not affect Sox9 expression. Our results show that actin polymerization regulates fibroblast matrix gene expression through MRTF in passaged chondrocytes.
authors.affiliation: CIHR-BioEngineering of Skeletal Tissues Team, Mount Sinai Hospital, University of Toronto, Toronto, Canada; Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada; Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, Canada.
authors.forename: Justin
authors.initials: J
authors.lastname: Parreno
authors.affiliation: CIHR-BioEngineering of Skeletal Tissues Team, Mount Sinai Hospital, University of Toronto, Toronto, Canada; Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada.
authors.forename: Sneha
authors.initials: S
authors.lastname: Raju
authors.affiliation: CIHR-BioEngineering of Skeletal Tissues Team, Mount Sinai Hospital, University of Toronto, Toronto, Canada; Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Canada.
authors.forename: Mortah Nabavi
authors.initials: MN
authors.lastname: Niaki
authors.affiliation: CIHR-BioEngineering of Skeletal Tissues Team, Mount Sinai Hospital, University of Toronto, Toronto, Canada; Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada; Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, Canada.
authors.forename: Katarina
authors.initials: K
authors.lastname: Andrejevic
authors.affiliation: CIHR-BioEngineering of Skeletal Tissues Team, Mount Sinai Hospital, University of Toronto, Toronto, Canada; Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada.
authors.forename: Amy
authors.initials: A
authors.lastname: Jiang
authors.affiliation: CIHR-BioEngineering of Skeletal Tissues Team, Mount Sinai Hospital, University of Toronto, Toronto, Canada; Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Canada.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Delve
authors.affiliation: CIHR-BioEngineering of Skeletal Tissues Team, Mount Sinai Hospital, University of Toronto, Toronto, Canada; Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Canada; Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Canada. Electronic address: rkandel@mtsinai.on.ca.
authors.forename: Rita
authors.initials: R
authors.lastname: Kandel
mesh_terms: D000199:Actins / Q000378:metabolism*; D021581:Active Transport, Cell Nucleus; D000813:Anilides / Q000494:pharmacology; D000818:Animals; D001549:Benzamides / Q000494:pharmacology; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology; D002417:Cattle; D054337:Cell Dedifferentiation; D002467:Cell Nucleus / Q000378:metabolism; D019902:Chondrocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D024042:Collagen Type I / Q000235:genetics / Q000378:metabolism*; D058105:Polymerization; D019063:Tenascin / Q000235:genetics / Q000378:metabolism*; D053778:Thiazolidines / Q000494:pharmacology; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D000199:Actins; D000813:Anilides; D001549:Benzamides; D019086:Bridged Bicyclo Compounds, Heterocyclic; C523455:CCG 1423; D024042:Collagen Type I; D019063:Tenascin; D053778:Thiazolidines; D014157:Transcription Factors; C037068:latrunculin B
keywords: Actin; Chondrocyte; Collagen; Dedifferentiation; Myocardin related transcription factor; Tenascin C