title: Glutaredoxin modulates platelet-derived growth factor-dependent cell signaling by regulating the redox status of low molecular weight protein-tyrosine phosphatase.
abstract: Glutaredoxin (GRX) is a glutathione-disulfide oxidoreductase involved in various cellular functions, including the redox-dependent regulation of certain integral proteins. Here we demonstrated that overexpression of GRX suppressed the proliferation of myocardiac H9c2 cells treated with platelet-derived growth factor (PDGF)-BB. After stimulation with PDGF-BB, the phosphorylation of PDGF receptor (PDGFR) beta was suppressed in GRX gene-transfected cells, compared with controls. Conversely, the phosphorylation was enhanced by depletion of GRX by RNA interference. In this study we focused on the role of low molecular weight protein-tyrosine phosphatase (LMW-PTP) in the dephosphorylation of PDGFRbeta via a redox-dependent mechanism. We found that depletion of LMW-PTP using RNA interference enhanced the PDGF-BB-induced phosphorylation of PDGFRbeta, indicating that LMW-PTP works for PDGFRbeta. The enhancement of the phosphorylation of PDGFRbeta was well correlated with inactivation of LMW-PTP by cellular peroxide generated in the cells stimulated with PDGF-BB. In vitro, with hydrogen peroxide treatment, LMW-PTP showed decreased activity with the concomitant formation of dithiothreitol-reducible oligomers. GRX protected LMW-PTP from hydrogen peroxide-induced oxidation and inactivation in concert with glutathione, NADPH, and glutathione disulfide reductase. This strongly suggests that retention of activity of LMW-PTP by enhanced GRX expression suppresses the proliferation of cells treated with PDGF-BB via enhanced dephosphorylation of PDGFRbeta. Thus, GRX plays an important role in PDGF-BB-dependent cell proliferation by regulating the redox state of LMW-PTP.
authors.affiliation: Department of Biochemistry and Molecular Biology in Disease, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8523, Japan.
authors.forename: Munetake
authors.initials: M
authors.lastname: Kanda
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Ihara
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Murata
authors.forename: Yoshishige
authors.initials: Y
authors.lastname: Urata
authors.forename: Takaaki
authors.initials: T
authors.lastname: Kono
authors.forename: Junji
authors.initials: J
authors.lastname: Yodoi
authors.forename: Shinji
authors.initials: S
authors.lastname: Seto
authors.forename: Katsusuke
authors.initials: K
authors.lastname: Yano
authors.forename: Takahito
authors.initials: T
authors.lastname: Kondo
mesh_terms: D000818:Animals; D002460:Cell Line; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D054477:Glutaredoxins; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008954:Models, Biological; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000502:physiology*; D010982:Platelet-Derived Growth Factor / Q000378:metabolism*; D017027:Protein Tyrosine Phosphatases / Q000737:chemistry*; D034622:RNA Interference; D051381:Rats; D015398:Signal Transduction
chemical_list: C516005:GLRX protein, human; C516007:Glrx protein, rat; D054477:Glutaredoxins; D010982:Platelet-Derived Growth Factor; D006861:Hydrogen Peroxide; D010088:Oxidoreductases; D017027:Protein Tyrosine Phosphatases