title: A carbon monoxide-releasing molecule (CORM-3) attenuates lipopolysaccharide- and interferon-gamma-induced inflammation in microglia.
abstract: The development of carbon monoxide-releasing molecules (CO-RMs) in recent years helped to shed more light on the diverse range of anti-inflammatory and cytoprotective activities of CO gas. In this study, we examined the effect of a ruthenium-based water-soluble CO carrier (CORM-3) on lipopolysaccharide (LPS)- and interferon-gamma (INF-gamma)-induced inflammatory responses in BV-2 microglial cells and explored the possible mechanisms of action. BV-2 microglial cells were stimulated with either LPS or INF-gamma in the presence of CORM-3 and the inflammatory response evaluated by assessing the effect on nitric oxide production (nitrite levels) and tumor necrosis factor-alpha (TNF-alpha) release. Similar experiments were also performed in the presence of inhibitors of guanylate cyclase (ODQ), NO synthase (L-NAME), heme oxygenase activity (tin protoporphyrin IX) or various mitogen-activated protein kinase (MAPK) inhibitors. CORM-3 significantly attenuated the inflammatory response to LPS and INF-gamma as evidenced by a significant reduction (p < 0.001) in nitrite levels and TNF-alpha production (P < 0.05). Such effect was maintained in the presence of ODQ, L-NAME or tin protoporphyrin without showing any cytotoxicity. The use of an inactive form of CORM-3 that does not contain carbonyl groups (Ru(DMSO)(4)Cl(2) failed to inhibit the increase in inflammatory markers suggesting that liberated CO mediates the observed effects. In addition, inhibition of phosphatidylinositol-3-phosphate kinase (PI3K) and extracellular signal-regulated kinase (ERK) pathways seemed to amplify the anti-inflammatory effect of CORM-3, particularly in cells stimulated with INF-gamma. These results suggest that the anti-inflammatory action of CORM-3 could be exploited to mitigate microglia activation in neuro-inflammatory diseases.
authors.affiliation: Vascular Biology Unit, Department of Surgical Research, Northwick Park Institute for Medical Research, Harrow, United Kingdom.
authors.forename: Mohamed G
authors.initials: MG
authors.lastname: Bani-Hani
authors.forename: David
authors.initials: D
authors.lastname: Greenstein
authors.forename: Brian E
authors.initials: BE
authors.lastname: Mann
authors.forename: Colin J
authors.initials: CJ
authors.lastname: Green
authors.forename: Roberto
authors.initials: R
authors.lastname: Motterlini
mesh_terms: D000818:Animals; D002248:Carbon Monoxide / Q000378:metabolism / Q000502:physiology*; D002460:Cell Line; D002470:Cell Survival; D004789:Enzyme Activation; D006162:Guanylate Cyclase / Q000378:metabolism; D006419:Heme Oxygenase (Decyclizing) / Q000378:metabolism; D007249:Inflammation / Q000378:metabolism; D007371:Interferon-gamma / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D017628:Microglia / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D009573:Nitrites / Q000378:metabolism; D009942:Organometallic Compounds / Q000378:metabolism / Q000494:pharmacology*; D000081082:Phosphoinositide-3 Kinase Inhibitors; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D008070:Lipopolysaccharides; D009573:Nitrites; D009942:Organometallic Compounds; D000081082:Phosphoinositide-3 Kinase Inhibitors; D014409:Tumor Necrosis Factor-alpha; C476530:tricarbonylchloro(glycinato)ruthenium(II); D002248:Carbon Monoxide; D007371:Interferon-gamma; D019001:Nitric Oxide Synthase; D006419:Heme Oxygenase (Decyclizing); D020928:Mitogen-Activated Protein Kinases; D006162:Guanylate Cyclase