title: Poly(ADP-ribose) polymerase-1 is a determining factor in Crm1-mediated nuclear export and retention of p65 NF-kappa B upon TLR4 stimulation.
abstract: The role of NF-kappaB in the expression of inflammatory genes and its participation in the overall inflammatory process of chronic diseases and acute tissue injury are well established. We and others have demonstrated a critical involvement of poly(ADP-ribose) polymerase (PARP)-1 during inflammation, in part, through its relationship with NF-kappaB. However, the mechanism by which PARP-1 affects NF-kappaB activation has been elusive. In this study, we show that PARP-1 inhibition by gene knockout, knockdown, or pharmacologic blockade prevented p65 NF-kappaB nuclear translocation in smooth muscle cells upon TLR4 stimulation, NF-kappaB DNA-binding activity, and subsequent inducible NO synthase and ICAM-1 expression. Such defects were reversed by reconstitution of PARP-1 expression. PARP-1 was dispensable for LPS-induced IkappaBalpha phosphorylation and subsequent degradation but was required for p65 NF-kappaB phosphorylation. A perinuclear p65 NF-kappaB localization in LPS-treated PARP-1(-/-) cells was associated with an export rather an import defect. Indeed, whereas PARP-1 deficiency did not alter expression of importin alpha3 and importin alpha4 and their cytosolic localization, the cytosolic levels of exportin (Crm)-1 were increased. Crm1 inhibition promoted p65 NF-kappaB nuclear accumulation as well as reversed LPS-induced p65 NF-kappaB phosphorylation and inducible NO synthase and ICAM-1 expression. Interestingly, p65 NF-kappaB poly(ADP-ribosyl)ation decreased its interaction with Crm1 in vitro. Pharmacologic inhibition of PARP-1 increased p65 NF-kappaB-Crm1 interaction in LPS-treated smooth muscle cells. These results suggest that p65 NF-kappaB poly(ADP-ribosyl)ation may be a critical determinant for the interaction with Crm1 and its nuclear retention upon TLR4 stimulation. These results provide novel insights into the mechanism by which PARP-1 promotes NF-kappaB nuclear retention, which ultimately can influence NF-kappaB-dependent gene regulation.
authors.affiliation: Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, 1901 Perdido Street, New Orleans, LA 70112, USA. mzerfa@lsuhsc.edu
authors.forename: Mourad
authors.initials: M
authors.lastname: Zerfaoui
authors.forename: Youssef
authors.initials: Y
authors.lastname: Errami
authors.forename: Amarjit S
authors.initials: AS
authors.lastname: Naura
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Hogyoung
authors.initials: H
authors.lastname: Kim
authors.forename: Jihang
authors.initials: J
authors.lastname: Ju
authors.forename: Tao
authors.initials: T
authors.lastname: Liu
authors.forename: Chetan P
authors.initials: CP
authors.lastname: Hans
authors.forename: Jong G
authors.initials: JG
authors.lastname: Kim
authors.forename: Zakaria Y
authors.initials: ZY
authors.lastname: Abd Elmageed
authors.forename: Shahriar
authors.initials: S
authors.lastname: Koochekpour
authors.forename: Andrew
authors.initials: A
authors.lastname: Catling
authors.forename: A Hamid
authors.initials: AH
authors.lastname: Boulares
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000235:genetics / Q000276:immunology; D000818:Animals; D002460:Cell Line; D002467:Cell Nucleus / Q000201:enzymology / Q000276:immunology / Q000378:metabolism*; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000096:biosynthesis; D005786:Gene Expression Regulation / Q000276:immunology; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000096:biosynthesis; D028884:Karyopherins / Q000037:antagonists & inhibitors / Q000502:physiology*; D008070:Lipopolysaccharides / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D032389:Myocytes, Smooth Muscle / Q000201:enzymology / Q000276:immunology / Q000378:metabolism; D000071137:Poly (ADP-Ribose) Polymerase-1; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D011065:Poly(ADP-ribose) Polymerases / Q000172:deficiency / Q000502:physiology*; D018160:Receptors, Cytoplasmic and Nuclear / Q000037:antagonists & inhibitors / Q000502:physiology*; D051197:Toll-Like Receptor 4 / Q000502:physiology*; D051996:Transcription Factor RelA / Q000037:antagonists & inhibitors / Q000378:metabolism* / Q000502:physiology; D000097606:Exportin 1 Protein
chemical_list: D004268:DNA-Binding Proteins; D018799:Intercellular Adhesion Molecule-1; D028884:Karyopherins; D008070:Lipopolysaccharides; D000071137:Poly (ADP-Ribose) Polymerase-1; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D011065:Poly(ADP-ribose) Polymerases; D018160:Receptors, Cytoplasmic and Nuclear; D051197:Toll-Like Receptor 4; D051996:Transcription Factor RelA; D000097606:Exportin 1 Protein; C498144:Rela protein, mouse; C493487:Tlr4 protein, mouse; C499320:PARP1 protein, human