title: Post-translational Activation of Glutamate Cysteine Ligase with Dimercaprol: A NOVEL MECHANISM OF INHIBITING NEUROINFLAMMATIONIN VITRO.
abstract: Neuroinflammation and oxidative stress are hallmarks of various neurological diseases. However, whether and how the redox processes control neuroinflammation is incompletely understood. We hypothesized that increasing cellular glutathione (GSH) levels would inhibit neuroinflammation. A series of thiol compounds were identified to elevate cellular GSH levels by a novel approach (i.e.post-translational activation of glutamate cysteine ligase (GCL), the rate-limiting enzyme in GSH biosynthesis). These small thiol-containing compounds were examined for their ability to increase intracellular GSH levels in a murine microglial cell line (BV2), of which dimercaprol (2,3-dimercapto-1-propanol (DMP)) was found to be the most effective compound. DMP increased GCL activity and decreased LPS-induced production of pro-inflammatory cytokines and inducible nitric-oxide synthase induction in BV2 cells in a concentration-dependent manner. The ability of DMP to elevate GSH levels and attenuate LPS-induced pro-inflammatory cytokine production was inhibited by buthionine sulfoximine, an inhibitor of GCL. DMP increased the expression of GCL holoenzyme without altering the expression of its subunits or Nrf2 target proteins (NQO1 and HO-1), suggesting a post-translational mechanism. DMP attenuated LPS-induced MAPK activation in BV2 cells, suggesting the MAPK pathway as the signaling mechanism underlying the effect of DMP. Finally, the ability of DMP to increase GSH via GCL activation was observed in mixed cerebrocortical cultures and N27 dopaminergic cells. Together, the data demonstrate a novel mechanism of GSH elevation by post-translational activation of GCL. Post-translational activation of GCL offers a novel targeted approach to control inflammation in chronic neuronal disorders associated with impaired adaptive responses.
authors.affiliation: From the Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045 and.
authors.forename: Pallavi B
authors.initials: PB
authors.lastname: McElroy
authors.affiliation: From the Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045 and.
authors.forename: Ashwini
authors.initials: A
authors.lastname: Sri Hari
authors.affiliation: the Department of Medicine, National Jewish Health, Denver, Colorado 80206.
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Day
authors.affiliation: From the Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045 and Manisha.Patel@ucdenver.edu.
authors.forename: Manisha
authors.initials: M
authors.lastname: Patel
mesh_terms: D000818:Animals; D002460:Cell Line; D016207:Cytokines / Q000037:antagonists & inhibitors; D004112:Dimercaprol / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D005721:Glutamate-Cysteine Ligase / Q000187:drug effects / Q000378:metabolism*; D005978:Glutathione / Q000378:metabolism; D007249:Inflammation / Q000517:prevention & control*; D020935:MAP Kinase Signaling System; D051379:Mice; D009420:Nervous System / Q000473:pathology; D010084:Oxidation-Reduction; D051381:Rats; D013438:Sulfhydryl Compounds / Q000378:metabolism
chemical_list: D016207:Cytokines; D013438:Sulfhydryl Compounds; D004112:Dimercaprol; D005721:Glutamate-Cysteine Ligase; D005978:Glutathione
keywords: Glutathione; cytokine; glutamate cysteine ligase; microglia; neurodegeneration; neuroinflammation; oxidative stress; post-translational