title: Cytokines induce protein kinase A-mediated signalling by a redox-dependent mechanism in rat renal mesangial cells.
abstract: Glomerular mesangial cells are smooth muscle cell-like pericytes and are regarded as key players in kidney diseases. In an inflammatory setting, these cells produce high amounts of inflammatory cytokines, chemokines and redox mediators such as reactive oxygen species or nitric oxide (NO). The temporal production of ROS, NO and other redox mediators markedly contributes to the final outcome of inflammatory diseases. Recently, we reported that platelet-derived growth factor forced mesangial cells to activate the regulatory subunit of protein kinase A (PKA RI) by a redox-dependent mechanism but independent from changes in cyclic AMP. This prompted us to further analyze the dimerization of PKA RI and activation of PKA-driven signalling in an inflammatory context. Stimulation of rat mesangial cells with interleukin-1β and tumour necrosis factor-α [2 nM] induced the formation of PKA RI heterodimers in a time-dependent manner. PKA RI dimerization was accompanied with the formation of ROS, NO and peroxynitrite as well as a depletion of reduced glutathione. Furthermore, dimerization of PKA RI was paralleled by enhanced activity of PKA as shown by the phosphorylation of vasodilator-stimulated phosphoprotein (VASP) at serine 157 that was independent of the formation of cyclic AMP. Remarkably, exogenously administered peroxynitrite potently induced dimerization of PKA RI, whereas pharmacologic inhibition of inducible NO synthase (iNOS) and scavenging of peroxynitrite reduced PKA RI dimerization and VASP phosphorylation to control levels thus clearly indicating a causal role for endogenously formed peroxynitrite on PKA signalling. Consequently, the treatment of inflammatory diseases with anti-oxidants or NOS inhibitors may alter PKA activity.
authors.affiliation: Pharmazentrum Frankfurt/ZAFES, Klinikum der Johann Wolfgang Goethe-Universität, Frankfurt am Main, Germany. Electronic address: k.f.beck@em.uni-frankfurt.de.
authors.forename: Karl-Friedrich
authors.initials: KF
authors.lastname: Beck
authors.affiliation: Pharmazentrum Frankfurt/ZAFES, Klinikum der Johann Wolfgang Goethe-Universität, Frankfurt am Main, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Euler
authors.affiliation: Pharmazentrum Frankfurt/ZAFES, Klinikum der Johann Wolfgang Goethe-Universität, Frankfurt am Main, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Eisel
authors.affiliation: Pharmazentrum Frankfurt/ZAFES, Klinikum der Johann Wolfgang Goethe-Universität, Frankfurt am Main, Germany.
authors.forename: Martina
authors.initials: M
authors.lastname: Beck
authors.affiliation: Pharmazentrum Frankfurt/ZAFES, Klinikum der Johann Wolfgang Goethe-Universität, Frankfurt am Main, Germany.
authors.forename: Yvette
authors.initials: Y
authors.lastname: Köhler
authors.affiliation: Institut für Biochemie, Pathobiochemie, Klinikum der Johann Wolfgang Goethe-Universität, Frankfurt am Main, Germany.
authors.forename: Lisa Katharina
authors.initials: LK
authors.lastname: Sha
authors.affiliation: Institut für Biochemie, Pathobiochemie, Klinikum der Johann Wolfgang Goethe-Universität, Frankfurt am Main, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: von Knethen
authors.affiliation: Pharmazentrum Frankfurt/ZAFES, Klinikum der Johann Wolfgang Goethe-Universität, Frankfurt am Main, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Longen
authors.affiliation: Pharmazentrum Frankfurt/ZAFES, Klinikum der Johann Wolfgang Goethe-Universität, Frankfurt am Main, Germany.
authors.forename: Josef
authors.initials: J
authors.lastname: Pfeilschifter
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D017868:Cyclic AMP-Dependent Protein Kinases / Q000096:biosynthesis*; D016207:Cytokines / Q000494:pharmacology*; D004790:Enzyme Induction / Q000187:drug effects / Q000502:physiology; D007668:Kidney / Q000187:drug effects* / Q000201:enzymology*; D050527:Mesangial Cells / Q000187:drug effects* / Q000201:enzymology*; D010084:Oxidation-Reduction / Q000187:drug effects; D051381:Rats; D015398:Signal Transduction / Q000187:drug effects* / Q000502:physiology
chemical_list: D016207:Cytokines; D017868:Cyclic AMP-Dependent Protein Kinases
keywords: Cytokines; FeTMPyP (PubChem CID: 16760420); Iodoacetamid (PubChem CID: 3727); Mesangial cells; N(G)-monomethylarginine (PubChem CID: 1323862); Nitric oxide; PKA; Peroxynitrite; Peroxynitrite (PubChem CID: 104806)