Abstract
Carbon monoxide-releasing molecules are emerging as a new class of pharmacological agents that regulate important cellular function by liberating CO in biological systems. Here, we examined the role of carbon monoxide-releasing molecule 3 (CORM-3) in modulating neuroinflammatory responses in BV-2 microglial cells, considering its practical application as a novel therapeutic alternative in the treatment of stroke. BV-2 microglia cells were incubated for 24 h in normoxic conditions with thrombin alone or in combination with interferon-γ to simulate the inflammatory response. Cells were also subjected to 12 h of hypoxia and reoxygenated for 24 h in the presence of thrombin and interferon-γ. In both set of experiments, the anti-inflammatory action of CORM-3 was evaluated by assessing its effect on nitric oxide production (nitrite levels) and tumor necrosis factor (TNF)-α release. CORM-3 (75 μM) did not show any cytotoxicity and markedly attenuated the inflammatory response to thrombin and interferon-γ in normoxia and to a lesser extent in hypoxia as evidenced by a reduction in nitrite levels and TNF-α production. Inactive CORM-3, which does not liberate CO and is used as a negative control, failed to prevent the increase in inflammatory mediators. Blockade of endogenous CO production by tin protoporphyrin-IX did not change the anti-inflammatory activity of CORM-3, suggesting that CO liberated from the compound is responsible for the observed effects. In addition, inhibition of the mitogen-activated protein kinases phosphatidyl inositol 3 kinase and extracellular signal-regulated kinase amplified the anti-inflammatory effect of CORM-3. These results suggest that the anti-inflammatory activity of CORM-3 could be exploited to mitigate microglia activity in stroke and other neuroinflammatory diseases.
Footnotes
-
doi:10.1124/jpet.106.104729.
-
ABBREVIATIONS: iNOS, inducible nitric oxide synthase; ROS, reactive oxygen species; HO, heme oxygenase; CO-RM, carbon monoxide-releasing molecule; CORM-3, tricarbonylchloro(lglycinato)ruthenium (II); SP600125, 1,9-pyrazoloanthrone; iCORM-3, inactivated CORM-3; SB203580, 4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)1H-imidazole; PD98059, 2′-amino-3′-methoxyflavone; LY294002, 2-(4-morpholinyl)-8-phenyl-1(4H)-benzopyran-4-one hydrochloride; TNF, tumor necrosis factor; LDH, lactate dehydrogenase; IFN-γ, interferon-γ; SnPPIX, tin protoporphyrin-IX; MAPK, mitogen-activated protein kinase; PI3K, phosphatidyl inositol 3 kinase; ERK, extracellular signal-regulated kinase; JNK, c-Jun NH2-terminal kinase; Thr, thrombin.
- Received March 16, 2006.
- Accepted June 12, 2006.
- The American Society for Pharmacology and Experimental Therapeutics
JPET articles become freely available 12 months after publication, and remain freely available for 5 years.Non-open access articles that fall outside this five year window are available only to institutional subscribers and current ASPET members, or through the article purchase feature at the bottom of the page.
|