Carbon liberated from CO-releasing molecules attenuates leukocyte infiltration in the small intestine of thermally injured mice.

AIM: To determine whether Carbon (CO) liberated from CO-releasing molecules attenuates leukocyte infiltration in the small intestine of thermally injured mice. METHODS: Thirty-six mice were assigned to four groups. Mice in the sham group (n = 9) were underwent to sham thermal injury; mice in the burn group (n = 9) received 15% total body surface area full-thickness thermal injury; mice in the burn + CORM-2 group (n = 9) were underwent to the same thermal injury with immediate administration of tricarbonyldichlororuthenium (II) dimer CORM-2 (8 mg/kg, i.v.); and mice in the burn+DMSO group (n = 9) were underwent to the same thermal injury with immediate administration of 160 muL bolus injection of 0.5% DMSO/saline. Histological alterations and granulocyte infiltration of the small intestine were assessed. Polymorphonuclear neutrophil (PMN) accumulation (myeloperoxidase assay) was assessed in mice mid-ileum. Activation of nuclear factor (NF)-kappa B, expression levels of intercellular adhesion molecule-1 (ICAM-1) and inducible heme oxygenase in mid-ileum were assessed. RESULTS: Treatment of thermally injured mice with CORM-2 attenuated PMN accumulation and prevented activation of NF-kappa B in the small intestine. This was accompanied by a decrease in the expression of ICAM-1. In parallel, burn-induced granulocyte infiltration in mid-ileum was markedly decreased in the burn mice treated with CORM-2. CONCLUSION: CORM-released CO attenuates leukocyte infiltration in the small intestine of thermally injured mice by interfering with NF-kappa B activation and protein expression of ICAM-1, and therefore suppressing the pro-adhesive phenotype of endothelial cells.

[Molecular mechanism of inhibition of early pulmonary injury and inflammatory response by exogenous carbon monoxide: experiment with mice].

OBJECTIVE: To investigate the effect of determine whether the CO-releasing molecules-liberated CO could attenuate leukocytes sequestration and the inflammatory response in the lung of thermally injured mice. METHODS: Thirty-six C57BL/6 mice were randomly divided into 3 groups: burn group, burned with hot water on the back skin with an area as large as 15% of the total body surface area with the hair shed so as o cause full-thickness thermal injury, CORM-2 group, undergoing the same thermal injury and then receiving intravenous injection of CORM-2 immediately, and sham operation group, undergoing sham thermal injury. Twenty-four hours later the mice were killed. The myeloperoxidase enzyme (MPO) level in lung tissue was detected. Evans blue test and lung wet/dry weight ratio were used to examine the lung edema degree. Bronchoalveolar lavage (BAL) fluid was collected to undergo ELISA to detect the tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta. Activation of nuclear factor (NF)-kappaB was detected with electrophoretic mobility shift assay. The expression level of intercellular adhesion molecule-1, ICAM-1) in the lung was assessed by Western blotting. Whole blood samples were collected from the left ventricles. Serum was isolated and used to stimulated lung endothelial cells for 4 h. Polymorphonuclear neutrophilic leukocytes (PMNs) were isolated from mice bone marrow, labeled with Na(51)CrO(4), cultured, and added with the murine lung endothelial cells (MLECs) stimulated by serums from the mice of the 3 groups so as to measure leukocyte adhesion. RESULTS: The MPO activity of the CORM-2 group was (42 +/- 7) U/g tissue, significantly lower than that of the burn group [(87 +/- 11) U/g tissue, P < 0.05]. The Evans blue extraction level of the CORM-1 group was (53.1 +/- 4.6), not significantly different from that of the burn group [(55.1 +/- 3.8), P > 0.05], however, still significantly higher than that of the sham group [(8.8 +/- 1.3), P < 0.05]. The wet/dry weight ratio of the CORM-2 group was 4.80 +/- 0.11, significantly higher than that of the sham group (3.20 +/- 0.07, P < 0.05), but not significantly different from that of the burn group (4.70 +/- 0.18, P > 0.05). The TNF-alpha and IL-1beta levels of the CORM-2 group were (92 +/- 4) pg/ml and (27.2 +/- 2.9) pg/ml respectively, both significantly higher than those of the sham group [(24 +/- 4) pg/ml and (6.6 +/- 1.0) pg/ml respectively, both P < 0.05], but significantly lower that those of the burn group [(160 +/- 9) pg/ml and (27.2 +/- 2.9) pg/ml respectively, both P < 0.05]. The A value for the lung ICAM-1 protein level of the CORM-1 group was (2.4 +/- 0.4), significantly higher than that of the sham group [(1.4 +/- 0.6)], however, significantly lower than that of the burn group [(3.5 +/- 1.1), P < 0.05]. The lung NF-kappaB activity of the CORM-1 group was significantly lower than that of the burn group. The PMN adhesion to the MLECs stimulated by the CORM-2-treated thermally injured mice serum was (25.4 +/- 5.6)%, significantly lower than that of the burn group [(46.5 +/- 8.5)%, P < 0.05]. Also, CORM-2 markedly decreased the production of inflammatory mediators in BAL fluid without suppressing the permeability of pulmonary microcirculation. CONCLUSION: CORM-released CO attenuates the inflammatory response in the lung of thermally injured mice by decreasing leukocyte sequestration and interfering with NF-kappaB activation, protein expression of ICAM-1, thus suppressing endothelial cells pro-adhesive phenotype.

Attenuation of leukocytes sequestration by carbon monoxide-releasing molecules: liberated carbon monoxide in the liver of thermally injured mice.

We sought to determine whether the CO-releasing molecules, ie, liberated CO, attenuates the leukocytes sequestration in the liver of thermally injured mice. Sixty-five mice were assigned to five groups in three respective experiments. In each experiment, mice in sham group (n = 7) and sham + CORM-2 group (n = 7) were underwent sham thermal injury, whereas mice in burn group (n = 7) received 15% TBSA full-thickness thermal injury, mice in burn + CORM-2 group (n = 7) underwent the same thermal injury with the immediate administration of CORM-2 (8 mg/kg intravenously), and mice in burn + DMSO group (n = 7) underwent the same thermal injury with an immediate 160 microl-bolus injection of 0.5% dimethyl sulfoxide/saline. Polymorphonuclear leucocyte (PMN) accumulation (assessed by the myeloperoxidase assay) was assessed in mice liver. Activation of nuclear factor kappa B (NF-kappaB) and the expression levels of ICAM-1 and VCAM-1 in liver were assessed. In an in vitro experiment, sinusoidal endothelial cells (SECs) isolated from the liver of normal mice were stimulated by experimental mice serum (50% v/v) for 4 hours. Subsequently, the adhesion of PMNs to SECs was assessed. In addition, the number and states (rolling or stationary) of leukocytes in liver were observed by intravital microscopy. Treatment of thermally injured mice with CORM-2 attenuated PMN accumulation and prevented activation of NF-kappaB in the liver, which was accompanied by a decrease of the expression of ICAM-1 and VCAM-1. In parallel, PMNs adhesion to SECs stimulated by CORM-2-treated thermally injured mice serum was markedly decreased. Intravital microscopy showed that the stationary leukocytes in thermally injured mice liver were significantly reduced by treatment of CORM-2. CORM-released CO attenuates leukocytes sequestration in the liver of burn mice by interfering with NF-kappaB activation, protein expression of ICAM-1 and VCAM-1, and therefore suppressing endothelial cells proadhesive phenotype.

[The inhibitory effects of extrinsic carbon monoxide-releasing molecules II on inflammatory responses in liver of mice with severe burns].

OBJECTIVE: To investigate the inhibitory effects of extrinsic carbon monoxide-releasing molecules II on inflammatory responses in liver of mice with severe burns and its potential mechanisms. METHODS: Forty-five male C57BL/6 mice were randomly divided into sham (simulation of burn with 37 degrees C warm water), sham + CORM-2 (with 8 mg/kg CORM-2 after the same manipulation as sham group), burn (with 15% TBSA full-thickness burns), burn + CORM-2 (with 8 mg/kg CORM-2 after the same manipulation as burn group), burn + DMSO (with DMSO after the same treatment as burn group) groups,with 9 mice in each group. The serum level of ALT and AST were determined at 24 post-burn hours (PBH), and the level of myeloperoxidase (MPO), nuclear factor (NF) kappaB, intercellular adhesion molecular (ICAM-1), vascular cell adhesion molecular (VCAM-1), as well as adhesion of polymorphonuclear leucocytes to sinusoidal endothelial cells (HSECs) after serum stimulation were detected and assessed at the same time-points. RESULTS: The level of ALT and AST (398 +/- 34,122 +/- 22 ), the activity of MPO and NF-kappaB, the protein level of ICAM-1 and VCAM-1 in burn group were obviously increased when compared with those in sham group and burn + CORM-2 group (P < 0.05 or P < 0.01). Additionally, the adhesion of PMN on HSEC after stimulation of serum in burn group was enhanced, while it was markedly inhibited after stimulation of serum in burn + CORM-2 group (P < 0.05). CONCLUSION: Extrinsic CORM-2 exhibits the ability to inhibit NF-kappaB activity, reduces the hepatic expression of ICAM-1 and VCAM-1, thereby alleviating sequestration of leukocytes after severe burns, so that hepatic inflammatory response is ameliorated, and liver function is improved.