Glucocorticoid receptor nitration leads to enhanced anti-inflammatory effects of novel steroid ligands.
It has recently emerged that posttranslational modification of proteins via nitration of tyrosine residues can alter their function. In this study, we describe that specific nitration of the glucocorticoid receptor (GR) by NCX-1015, a novel NO-donating prednisolone derivative (prednisolone 21-[4'-(nitrooxymethyl)benzoate), results in an enhancement of GR-mediated events. Incubation of PBMC and U937 cells with 1-10 micro M NCX-1015 caused faster activation of GR as assessed by augmented 1) binding to [(3)H]dexamethasone, 2) dissociation from heat shock protein 90, and 3) nuclear translocation. PBMCs treated with NCX-1015 contained GR that had undergone tyrosine nitration. The chemistry facilitating the increase in steroid binding capacity observed with NCX-1015 is specific, because changing the position of the NO-donating group or ubiquitous nitration by addition of an NO donor was unable to mimic this event. In vivo treatment with NCX-1015 provoked GR nitration and faster heat shock protein 90 dissociation as assessed in peritoneal cells. Accordingly, NCX-1015, but not prednisolone or other derivatives, produced a rapid inhibition of the early neutrophil recruitment and mediator generation in a model of peritonitis. In conclusion, we report here for the first time that posttranslational modification of GR by this novel nitrosteroid is associated with its enhanced anti-inflammatory activity.
Paul-Clark
Mark J
MJ
The William Harvey Research Institute, Queen Mary School of Medicine and Dentistry, London, United Kingdom.
Roviezzo
Fiorentina
F
Flower
Roderick J
RJ
Cirino
Giuseppe
G
Soldato
Piero Del
PD
Adcock
Ian M
IM
Perretti
Mauro
M
D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000378:metabolism* / Q000494:pharmacology*; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D003907:Dexamethasone / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D007274:Injections, Intraperitoneal; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000378:metabolism; D008024:Ligands; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D009569:Nitric Oxide / Q000378:metabolism* / Q000502:physiology; D010538:Peritonitis / Q000473:pathology / Q000517:prevention & control; D011239:Prednisolone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000378:metabolism* / Q000494:pharmacology*; D011485:Protein Binding / Q000187:drug effects; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D011965:Receptors, Glucocorticoid / Q000235:genetics / Q000378:metabolism*; D020298:U937 Cells; D015854:Up-Regulation / Q000187:drug effects*
D000893:Anti-Inflammatory Agents; D018841:HSP90 Heat-Shock Proteins; D008024:Ligands; D011965:Receptors, Glucocorticoid; C418962:prednisolone 21-((4'-nitrooxymethyl)benzoate); D009569:Nitric Oxide; D003907:Dexamethasone; D011239:Prednisolone