PARP-1 inhibitors DPQ and PJ-34 negatively modulate proinflammatory commitment of human glioblastoma cells

Neurochem Res. 2013 Jan;38(1):50-8. doi: 10.1007/s11064-012-0887-x. Epub 2012 Sep 26.

Abstract

Poly(ADP-ribose) polymerases (PARPs) are recognized as key regulators of cell survival or death. PARP-1 is essential to the repair of DNA single-strand breaks via the base excision repair pathway. The enzyme may be overactivated in response to inflammatory cues, thus depleting cellular energy pools and eventually causing cell death. Accordingly, PARP-1 inhibitors, acting by competing with its physiological substrate NAD(+), have been proposed to play a protective role in a wide range of inflammatory and ischemia/reperfusion-associated diseases. Recently, it has also been reported that PARP-1 regulates proinflammatory mediators, including cytokines, chemokines, adhesion molecules, and enzymes (e.g., iNOS). Furthermore, PARP-1 has been shown to act as a coactivator of NF-κB- and other transcription factors implicated in stress/inflammation, as AP-1, Oct-1, SP-1, HIF, and Stat-1. To further substantiate this hypothesis, we tested the biomolecular effects of PARP-1 inhibitors DPQ and PJ-34 on human glioblastoma cells, induced to a proinflammatory state with lipopolysaccharide and Interferon-γ. PARP-1 expression was evaluated by laser scanning confocal microscopy immunofluorescence (LSM); nitrite production, LDH release and cell viability were also determined. LSM of A-172, SNB-19 and CAS-1 cells demonstrated that DPQ and PJ-34 downregulate PARP-1 expression; they also cause a decrease of LDH release and nitrite production, while increasing cell viability. Similar effects were caused in all three cell lines by N-mono-methyl-arginine, a well known iNOS inhibitor, and by L-carnosine and trehalose, two antioxidant molecules. These results demonstrate that, similar to other well characterized drugs, DPQ and PJ-34 reduce cell inflammation and damage that follow PARP-1 overexpression, while they increase cell survival: this suggests their potential exploitation in clinical Medicine.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Inflammatory Agents*
  • Biomarkers / metabolism
  • Brain Neoplasms / pathology*
  • Carnosine / pharmacology
  • Cell Line, Tumor
  • Cell Survival / drug effects
  • Coloring Agents
  • Down-Regulation / drug effects
  • Fluorescent Antibody Technique
  • Glioblastoma / pathology*
  • Humans
  • Isoquinolines / pharmacology*
  • L-Lactate Dehydrogenase / biosynthesis
  • Microscopy, Confocal
  • Nitrites / metabolism
  • Phenanthrenes / pharmacology*
  • Piperidines / pharmacology*
  • Poly (ADP-Ribose) Polymerase-1
  • Poly(ADP-ribose) Polymerase Inhibitors*
  • Tetrazolium Salts
  • Thiazoles
  • Trehalose / pharmacology

Substances

  • Anti-Inflammatory Agents
  • Biomarkers
  • Coloring Agents
  • Isoquinolines
  • N-(oxo-5,6-dihydrophenanthridin-2-yl)-N,N-dimethylacetamide hydrochloride
  • Nitrites
  • Phenanthrenes
  • Piperidines
  • Poly(ADP-ribose) Polymerase Inhibitors
  • Tetrazolium Salts
  • Thiazoles
  • 3,4-dihydro-5-(4-(1-piperidinyl)butoxy)-1(2H)-isoquinolinone
  • Carnosine
  • Trehalose
  • L-Lactate Dehydrogenase
  • PARP1 protein, human
  • Poly (ADP-Ribose) Polymerase-1
  • thiazolyl blue