Modulation of Thrombin-Induced Neuroinflammation in BV-2 Microglia by Carbon Monoxide-Releasing Molecule 3

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-␥ 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-␥. 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)-␣ release. CORM-3 (75 M) did not show any cytotoxicity and markedly attenuated the inflammatory response to thrombin and interferon-␥ in normoxia and to a lesser extent in hypoxia as evidenced by a reduction in nitrite levels and TNF-␣ 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.Stroke is the major cause of disabilities in adults, leaving more than half of the survivors dependent on others for everyday activities (Wolfe et al., 2000). It is also a major cause of dementia, depression, epilepsy, and falls (Rothwell et al., 2004). This pathological event is characterized by blockade of blood supply to the brain and consequently oxygen and glucose deprivation, which lead to necrotic cell death and tissue infarct. Rescuing the surrounding partially ischemic penumbra depends on the severity of brain edema, subsequent neuroinflammation, and production of free radicals.Microglia are the main inflammatory-reacting cells in the brain after ischemia (Suk, 2004). They act through redoxsensitive inflammatory enzymes such as inducible nitric oxide synthase (iNOS) and NAD(P)H oxidase, which produce NO, superoxide, peroxynitrite, and other reactive oxygen species (ROS) that mediate their phagocytic ability. Free radicals generated during the inflammatory process can directly damage neurons by interacting with their lipid-rich membranes or by increasing ␣-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid/kainate receptor susceptibility to the toxic effects of glutamate (Zhao et al., 2004).Another important ...

Mitochondrial Quality Control as a Therapeutic Target

“…CORMs also show many of the protective features of authentic CO gas, e.g., suppressing the inflammatory response in glial cells (Bani-Hani et al, 2006), and may therefore offer neuroprotection. The apparent inconsistency of neuroprotection in the literature has caused confusion but may in part reflect the choice of CORM and route of administration.…”

Improved Myocardial Function After Cold Storage With Preservation Solution Supplemented With a Carbon Monoxide–Releasing Molecule (CORM-3)

“…18 -21 These carbon monoxide-releasing molecules (CO-RMs) have been initially demonstrated to protect against myocardial ischemia-reperfusion injury and heart rejection, 19 but more recently their beneficial effects have been extended to inflammatory conditions and drug-induced nephrotoxicity. [22][23][24][25][26] In the context of organ preservation, CO-RMs added to flushing and cold storage solutions have shown protection in kidneys, 27 while ex vivo application of CO gas to University of Wisconsin solutions prevented intestinal cold ischemia-reperfusion injury. 28 In the present study, we investigated the myocardial recovery of isolated hearts after cold ischemic storage in St Thomas cardioplegic solution supplemented with a fast CO-releaser (CORM-3).…”

The Carbon Monoxide-Releasing Molecule Tricarbonyldichlororuthenium(II) Dimer Protects Human Osteoarthritic Chondrocytes and Cartilage from the Catabolic Actions of Interleukin-1β

“…These agents are also able to deliver CO and protect isolated kidneys against cold preservation and ischemia-reperfusion (Sandouka et al, 2006). It is interesting to note that CO-RMs have shown anti-inflammatory effects in some cell lines, including RAW 264.7 macrophages (Sawle et al, 2005), microglia (Bani-Hani et al, 2006), and Caco-2 . In addition, these compounds can modulate leukocyte-endothelial cell interactions (Urquhart et al, 2007).…”