title: Smad3 mediates TGF-beta1-induced collagen gel contraction by human lung fibroblasts.
abstract: Transforming growth factor-beta1 (TGF-beta1) is a key mediator in tissue repair and fibrosis. Using small interference RNA (siRNA), the role of Smad2 and Smad3 in TGF-beta stimulation of human lung fibroblast contraction of collagenous matrix and induction of alpha-SMA and the role of alpha-SMA in contraction were assessed. HFL-1 cells were transfected with Smad2, Smad3 or control-siRNA, and cultured in floating Type I collagen gels +/- -TGF-beta1. TGF-beta1 augmented gel contraction in Smad2-siRNA- and control-siRNA-treated cells, but had no effect in Smad3-siRNA-treated cells. Similarly, TGF-beta1 upregulated alpha-SMA in Smad2-siRNA- and control-siRNA-treated cells, but had no effect on Smad3-siRNA-treated cells. Alpha-SMA-siRNA-treated cells did not contact the collagen gels with or without TGF-beta1, suggesting alpha-SMA is required for gel contraction. Thus, Smad3 mediates TGF-beta1-induced contraction and alpha-SMA induction in human lung fibroblasts. Smad3, therefore, could be a target for blocking contraction of human fibrotic tissue induced by TGF-beta1.
authors.affiliation: Pulmonary and Critical Care Medicine, University of Nebraska Medical Center, Omaha, NE, USA.
authors.forename: Tetsu
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Xiangde
authors.initials: X
authors.lastname: Liu
authors.forename: Fu-Qiang
authors.initials: FQ
authors.lastname: Wen
authors.forename: Tadashi
authors.initials: T
authors.lastname: Kohyama
authors.forename: Lei
authors.initials: L
authors.lastname: Shen
authors.forename: Xing Qi
authors.initials: XQ
authors.lastname: Wang
authors.forename: Mitsuyoshi
authors.initials: M
authors.lastname: Hashimoto
authors.forename: Lijun
authors.initials: L
authors.lastname: Mao
authors.forename: Shinsaku
authors.initials: S
authors.lastname: Togo
authors.forename: Shin
authors.initials: S
authors.lastname: Kawasaki
authors.forename: Hisatoshi
authors.initials: H
authors.lastname: Sugiura
authors.forename: Koichiro
authors.initials: K
authors.lastname: Kamio
authors.forename: Stephen I
authors.initials: SI
authors.lastname: Rennard
mesh_terms: D000199:Actins / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D000818:Animals; D001696:Biomechanical Phenomena; D002460:Cell Line; D024042:Collagen Type I / Q000502:physiology*; D005347:Fibroblasts / Q000378:metabolism / Q000502:physiology*; D005782:Gels; D006801:Humans; D008168:Lung / Q000166:cytology* / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics; D051381:Rats; D051899:Smad2 Protein / Q000235:genetics / Q000502:physiology; D051900:Smad3 Protein / Q000235:genetics / Q000502:physiology*; D016212:Transforming Growth Factor beta / Q000502:physiology*; D053773:Transforming Growth Factor beta1
chemical_list: D000199:Actins; D024042:Collagen Type I; D005782:Gels; D034741:RNA, Small Interfering; D051899:Smad2 Protein; D051900:Smad3 Protein; C508960:TGFB1 protein, human; C508962:Tgfb1 protein, rat; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1