Flavocoxid, a dual inhibitor of COX-2 and 5-LOX of natural origin, attenuates the inflammatory response and protects mice from sepsis.

INTRODUCTION: Cecal ligation and puncture (CLP) is an inflammatory condition that leads to multisystemic organ failure. Flavocoxid, a dual inhibitor of cyclooxygenase (COX-2) and 5-lipoxygenase (5-LOX), has been shown in vitro to possess antiinflammatory activity in lipopolysaccharide (LPS)-stimulated rat macrophages by reducing nuclear factor (NF)-κB activity and COX-2, 5-LOX and inducible nitric oxide synthase (iNOS) expression. The aim of this study was to evaluate the effects of flavocoxid in a murine model of CLP-induced polymicrobial sepsis. METHODS: C57BL/6J mice were subjected to CLP or sham operation. In a first set of experiments, an intraperitoneal injection of flavocoxid (20 mg/kg) or vehicle was administered 1 hour after surgery and repeated every 12 hours. Survival rate was monitored every 24 hours throughout 120 hours. Furthermore, additional groups of sham and CLP mice were killed 18 hours after surgical procedures for blood-sample collection and the lung and liver were collected for biomolecular, biochemical and histopathologic studies. RESULTS: COX-2, 5-LOX, tumor necrosis factor-α (TNF-α), interleukin (IL)-6, IL-10, extracellular-regulated-kinase 1/2 (ERK), JunN-terminal kinase (JNK), NF-κB, and ß-arrestin 2 protein expression were evaluated in lung and liver with Western blot analysis. In addition, leukotriene B4 (LTB4), prostaglandin E2 (PGE2), cytokines, and lipoxin A4 serum content were measured with an enzyme-linked immunosorbent assay (ELISA). Flavocoxid administration improved survival, reduced the expression of NF-κB, COX-2, 5-LOX, TNF-α and IL-6 and increased IL-10 production. Moreover, flavocoxid inhibited the mitogen-activated protein kinases (MAPKs) pathway, preserved ß-arrestin 2 expression, reduced blood LTB4, PGE2, TNF-α and IL-6, and increased IL-10 and lipoxin A4 serum levels. The treatment with flavocoxid also protected against the histologic damage induced by CLP and reduced the myeloperoxidase (MPO) activity in the lung and liver. CONCLUSIONS: Flavocoxid protects mice from sepsis, suggesting that this dual inhibitor may represent a promising approach in such a life-threatening condition.

Activation of the cholinergic anti-inflammatory pathway reduces NF-kappab activation, blunts TNF-alpha production, and protects againts splanchic artery occlusion shock.

The cholinergic anti-inflammatory pathway has not yet been studied in splanchnic artery occlusion (SAO) shock. We investigated whether electrical stimulation (STIM) of efferent vagus nerves suppresses the inflammatory cascade in SAO shock. Animals were subjected to clamping of the splanchnic arteries for 45 min, followed by reperfusion. This surgical procedure resulted in an irreversible state of shock (SAO shock). Sham-operated animals were used as controls. Two minutes before the start of reperfusion, rats were subjected to bilateral cervical vagotomy (VGX) or sham surgical procedures. Application of constant voltage pulses to the caudal vagus ends (STIM: 5 V, 2 ms, 6 Hz for 15 min, 5 min after the beginning of reperfusion) increased survival rate (VGX + SAO + Sham STIM = 0% at 4 h of reperfusion; VGX + SAO + STIM = 90% at 4 h of reperfusion), reverted the marked hypotension, inhibited IkappaBalpha liver loss, blunted the augmented nuclear factor-kappaB activity, decreased hepatic tumor necrosis factor (TNF)-alpha mRNA (VGX + SAO + Sham STIM = 1.0 +/- 1.9 TNF-alpha/glyceraldehyde-3-phosphate dehydrogenase ratio; VGX + SAO + STIM = 0.3 +/- 0.2 TNF-alpha/glyceraldehyde-3-phosphate dehydrogenase ratio), reduced plasma TNF-alpha (VGX + SAO + Sham STIM = 118 +/- 19 pg/mL; VGX + SAO + STIM = 39 +/- 8 pg/mL), ameliorated leukopenia, and decreased leukocyte accumulation, as revealed by means of myeloperoxidase activity in the ileum (VGX + SAO + Sham STIM = 7.9 +/- 1 U/g tissue; VGX + SAO + STIM = 3.1 +/- 0.7 U/g tissue) and in the lung (VGX + SAO + Sham STIM = 8.0 +/- 1.0 U/g tissue; VGX + SAO + STIM = 3.2 +/- 0.6 U/g tissue). Chlorisondamine, a nicotinic receptor antagonist, abated the effects of vagal stimulation. Our results show a parasympathetic inhibition of nuclear factor-kappaB and TNF-alpha in SAO shock.

Efferent vagal fibre stimulation blunts nuclear factor-kappaB activation and protects against hypovolemic hemorrhagic shock.

BACKGROUND: We investigated whether electrical stimulation (STIM) of efferent vagus nerves may suppress nuclear factor (NF)-kappaB activation and the inflammatory cascade in hemorrhagic (Hem) shock. METHODS AND RESULTS: Rats were subjected to bilateral cervical vagotomy (VGX) or sham surgical procedures. Hem shock was induced by intermittent withdrawing of blood until mean arterial pressure stabilized within the range of 35 to 40 mm Hg. Application of constant voltage pulses to the caudal vagus ends (STIM; 5 V, 2 ms, 1 Hz for 12 minutes, 5 minutes after mean arterial pressure stabilization) increased survival time (VGX+Hem+Sham STIM=38+/-3 minutes; VGX+Hem+STIM >180 minutes), reverted the marked hypotension (VGX+Hem+Sham STIM=33+/-3 mm Hg; VGX+Hem+STIM=66+/-5 mm Hg), inhibited IkappaBalpha liver loss, and blunted the augmented NF-kappaB activity, decreased hepatic tumor necrosis factor (TNF)-alpha mRNA (VGX+Hem+Sham STIM=1.42+/-0.5 amount of TNF-alpha m-RNA; VGX+Hem+STIM=0.51+/-0.2 amount of TNF-alpha mRNA), and reduced plasma TNF-alpha (VGX+Hem+Sham STIM=190+/-24 pg/mL; VGX+Hem+STIM=87+/-15 pg/mL). Chlorisondamine, a nicotinic receptor antagonist, abated the effects of vagal stimulation. CONCLUSIONS: Our results show a parasympathetic inhibition of NF-kappaB by which the brain opposes NF-kappaB activation in the liver and modulates the inflammatory response during acute hypovolemic hemorrhagic shock.

Lipid peroxidation inhibition by raxofelast improves angiogenesis and wound healing in experimental burn wounds.

We investigated the effects of raxofelast, a lipid peroxidation inhibitor, in an experimental model of burn wounds. C57BL/6 male mice of 25-30 g were immersed in 80 degrees C water for 10 seconds to achieve a partial-thickness scald burn. Animals received intraperitoneally either raxofelast (20 mg/kg/day for 14 days in 100 microL) or its vehicle alone (100 microL/day for 14 days). On day 14, burn areas were used for measuring conjugated dienes, reduced glutathione levels, histological damage, neoangiogenesis by immunohistochemistry and expression (Western blot) of the specific endothelial marker CD31 as well as quantification of microvessel density, VEGF wound content, endothelial and inducible nitric oxide synthase (eNOS and iNOS) expression and wound nitrite content. Raxofelast decreased tissue conjugated dienes (vehicle 6.1 +/- 1.4 DeltaABS/mg protein; raxofelast 3.7 +/- 0.8 DeltaABS/mg protein), prevented tissue glutathione consumption (vehicle 3.2 +/- 0.9 micromol/g protein; raxofelast 6.7 +/- 1.8 mumol/g protein), increased epithelial proliferation, extracellular matrix maturation, and augmented neoangiogenesis as suggested by the marked increase in microvessel density and by the robust expression of the specific endothelial marker CD31 (vehicle 9.4 +/- 1.1 integrated intensity; raxofelast 14.8 +/- 1.8 integrated intensity). Furthermore, raxofelast enhanced VEGF wound content (vehicle 1.4 +/- 0.4 pg/mg protein; raxofelast 2.4 +/- 0.6 pg/mg protein), caused a marked expression of eNOS (vehicle 16.1 +/- 3 integrated intensity; raxofelast 26.2 +/- 4 integrated intensity) and iNOS (vehicle 9.1 +/- 1.8 integrated intensity; raxofelast 16.2 +/- 3.5 integrated intensity) and increased wound nitrite content. Lipid peroxidation inhibition by raxofelast may be an effective therapeutic approach to improve clinical outcomes after thermal injury.

Crucial role of nuclear factor-kappaB in neointimal hyperplasia of the mouse carotid artery after interruption of blood flow.

We used a molecular genetics approach to investigate the role of nuclear factor-kappaB (NF-kappaB) in neointimal hyperplasia induced by flow interruption of carotid artery in mice. Wild type mice (WT mice) and mice rendered deficient in p105, the precursor of p50, one of the components of the multimeric transcription factor NF-kappaB (NF-kappaB knockout mice; KO mice), were subjected to a complete ligation of the left common carotid artery. Morphometric analysis of the structural alteration caused by the disruption of the arterial blood flow was performed 14 days after surgery. Furthermore the expression of intercellular adhesion molecule-1 (ICAM-1) in injured arteries was evaluated 4 days after artery ligation by the means of reverse transcriptase polymerase chain reaction (RT-PCR) and quantification of the ICAM-1 protein levels. In a separate experiment normal mice were randomly assigned to receive a recombinant adeno-associated virus (rAAV) encoding the gene for the NF-kappaB inhibitory protein IkappaBalpha (rAAV-IkappaBalpha), or the beta-galactosidase gene (rAAV-LacZ), both at a dose of 10(11) copies and 2 weeks later were subjected to the complete ligation of the left carotid artery. NF-kappaB activity (studied by means of electrophoretic mobility shift assay-EMSA), IkappaBalpha expression (evaluated by Western blot analysis) ICAM-1 evaluation (RT-PCR and quantification of the protein levels) and a morphometric analysis were evaluated in the injured arteries. Disruption of the arterial blood flow caused a marked neointimal hyperplasia. The mean intimal area was 0.023+/-0.002 mm(2) in wild type mice compared with 0.002+/-0.001 mm(2) in NF-kappaB knockout mice. ICAM-1 expression was 1.7+/-0.8 relative amount of ICAM-1 mRNA in wild type mice compared with 0.4+/-0.06 relative amount of ICAM-1 mRNA in NF-kappaB knockout mice. ICAM-1 protein levels were also significantly reduced in NF-kappaB knockout mice. Injured arteries treated with rAAV-IkappaBalpha had a greater expression of IkappaBalpha and lower NF-kappaB activity, when compared with vessels treated with rAAV-LacZ. Furthermore, ICAM-1 expression was markedly attenuated by the treatment with rAAV-IkappaBalpha (rAAV-LacZ=1.6+/-0.8 relative amount of ICAM-1 mRNA; rAAV-IkappaBalpha=0.55+/-0.04 relative amount of ICAM-1 mRNA). ICAM-1 protein levels were also significantly decreased in rAAV-IkappaBalpha treated mice. Finally the mean intimal area was 0.028+/-0.003 mm(2) in left carotid arteries treated with rAAV-LacZ whereas it was 0.003+/-0.004 mm(2) in vessels treated with rAAV-IkappaBalpha. Our data indicate that NF-kappaB plays a crucial role in neointimal hyperplasia induced by flow cessation in the mouse carotid artery, and in addition suggest that rAAV-mediated gene transfer of IkappaBalpha might represent a novel therapeutic approach to the treatment of restenosis.

Lipid peroxidation inhibition reduces NF-kappaB activation and attenuates cerulein-induced pancreatitis.

Increased lipid peroxidation, enhanced nuclear factor kappa-B (NF-kappaB) activation and augmented tumor necrosis factor-alpha (TNF-alpha) production have been implicated in cerulein-induced pancreatitis. We investigated whether lipid peroxidation inhibition might reduce NF-kappaB activation and the inflammatory response in cerulein-induced pancreatitis. Male Sprague-Dawley rats of 230-250g body weight received administration of cerulein (80 microg/kg s.c. for each of four injections at hourly intervals). A control group received four s.c. injections of 0.9% saline at hourly intervals. Animals were randomized to receive either raxofelast, an inhibitor of lipid peroxidation (20 mg/kg i.p. administered with the first cerulein injection) or its vehicle (1 ml/kg of a 10% DMSO/NaCl solution). All these rats were sacrificed 2 h after the last injection of either cerulein or its vehicle. Raxofelast administration (20 mg/kg i.p. with the first cerulein) significantly reduced malondialdehyde (MDA) levels, an index of lipid peroxidation (CER + DMSO = 3.075 +/- 0.54 micromol/g; CER + raxofelast = 0.693 +/- 0.18 micromol/g; p < 0.001), decreased myeloperoxidase (MPO) activity (CER + DMSO = 22.2 +/- 3.54 mU/g; CER + raxofelast = 9.07 +/- 2.05 mU/g, p < 0.01), increased glutathione levels (GSH) (CER + DMSO = 5.21 +/- 1.79 micromol/g; CER + raxofelast = 15.71 +/- 2.14 micronol/g; p < 0.001), and reduced acinar cell damage evaluated by means of histology and serum levels of both amylase (CER + DMSO = 4063 +/- 707.9 U/l; CER + raxofelast = 1198 +/- 214.4 U/l; p < 0.001), and lipase (CER + DMSO = 1654 +/- 330 U/l; CER + raxofelast = 386 +/- 118.2 U/l; p < 0.001), Furthermore, raxofelast reduced pancreatic NF-kappaB activation and the TNF-alpha mRNA levels and tissue content of mature protein in the pancreas. Indeed, lipid peroxidation inhibition might be considered a potential therapeutic approach to prevent the severe damage in acute pancreatitis.

Protective effects of SP600125 a new inhibitor of c-jun N-terminal kinase (JNK) and extracellular-regulated kinase (ERK1/2) in an experimental model of cerulein-induced pancreatitis.

Extracellular regulated kinases (ERK1/2) and c-Jun N-terminal Kinases (JNK), are generally considered to play a key role in signal transduction pathways activated by a wide range of stimuli. We studied the effects of SP600125, a novel inhibitor of both JNK and ERK1/2, in male C57/BL6 mice given with an hyper-stimulating dose of cerulein (50 microg/kg for each of four injections at hourly intervals) to elicit secretagogue-induced pancreatitis. A control group received four intra-peritoneal injections of 0.9% saline at hourly intervals. Animals were randomized to receive either SP600125 (15 mg/kg i.p. administered 2 h before and 30 min after the first injection of cerulein) or its vehicle (1 ml/kg of a 10% DMSO/NaCl solution). A group of animals was killed 30 minutes after the last cerulein injection to evaluate pancreatic JNK and ERK1/2 activation by Western Blot analysis. Another group was sacrificed 2 hours after the last cerulein injection to evaluate serum lipase and amylase levels, pancreas oedema, pancreatic content of Tumor Necrosis Factor-alpha (TNF-alpha) and Intercellular adhesion molecule-1 (ICAM-1) and the histological alterations. SP600125 inhibited almost totally JNK activation (90%) and partially ERK1/2 activation (45%), reduced the serum lipase and amylase levels and the degree of oedema, blunted the increased pancreatic content of TNF-alpha and ICAM-1 and protected against the histological damage. Our data confirm that both JNK and ERK1/2 activation plays a key role in acute pancreatitis and that SP600125 may represent a potential therapeutic approach to the treatment of patients at high risk of developing this life-threatening condition.

Recombinant human erythropoietin improves angiogenesis and wound healing in experimental burn wounds.

OBJECTIVE: Erythropoietin interacts with vascular endothelial growth factor (VEGF) and stimulates endothelial cell mitosis and motility; thus it may be of importance in the complex phenomenon of wound healing. The purpose of this study was to investigate the effect of recombinant human erythropoietin (rHuEPO) on experimental burn wounds. DESIGN: Randomized experiment. SETTING: Research laboratory. SUBJECTS: C57BL/6 male mice weighing 25-30 g. INTERVENTIONS: Mice were immersed in 80 degrees C water for 10 secs to achieve a deep-dermal second degree burn. Animals were randomized to receive either rHuEPO (400 units/kg/day for 14 days in 100 microL subcutaneously) or its vehicle alone (100 microl/day distilled water for 14 days subcutaneously). On day 14 the animals were killed. Burn areas were used for histologic examination, evaluation of neoangiogenesis by immunohistochemistry, and expression (Western blot) of the specific endothelial marker CD31 as well as quantification of microvessel density, measurement of VEGF wound content (enzyme-linked immunosorbent assay), expression (Western blot) of endothelial and inducible nitric oxide synthases, and determination of wound nitric oxide (NO) products. MEASUREMENTS AND MAIN RESULTS: rHuEPO increased burn wound reepithelialization and reduced the time to final wound closure. These effects were completely abated by a passive immunization with specific antibodies against erythropoietin. rHuEPO improved healing of burn wound through increased epithelial proliferation, maturation of the extracellular matrix, and angiogenesis. The hematopoietic factor augmented neoangiogenesis as suggested by the marked increase in microvessel density and by the robust expression of the specific endothelial marker CD31. Furthermore, rHuEPO enhanced the wound content of VEGF caused a marked expression of endothelial and inducible nitric oxide synthases and increased wound content of nitric oxide products. CONCLUSIONS: Our study suggests that rHuEPO may be an effective therapeutic approach to improve clinical outcomes after thermal injury.

Attenuated cerulein-induced pancreatitis in nuclear factor-kappaB-deficient mice.

Nuclear factor (NF)-kappaB plays a central role in acute pancreatitis. We studied cerulein (CER)-induced pancreatitis in NF-kappaB knockout (KO) mice. NF-kappaB KO mice and normal control littermate wild-type (WT) mice were given four hyperstimulating doses of cerulein every hour to elicit secreatagogue-induced pancreatitis. Malonildialdehyde activity, glutathione levels, myeloperoxidase activity, TNF-alpha, and NF-kappaB binding activity and its inhibitory protein IkappaBalpha were studied in the pancreas. Furthermore, we measured plasma lipase and amylase and the histological damage. KO mice had reduced malonildialdehyde levels (WT + CER = 4.083 +/- 0.95 micromol/g; KO + CER = 1.513 +/- 0.63 microol/g), decreased myeloperoxidase activity (WT + CER = 19.3 +/- 2.39 mU/g; KO + CER = 10.21 +/- 2.05 mU/g), increased glutathione levels (WT + CER 6.22 +/- 2.46 micromol/g; KO + CER = 15. 516 +/- 2.92 micromol/g), and reduced serum levels of amylase (WT + CER = 2519 +/- 656.9 U/L; KO + CER = 916 +/- 280.4 U/L) and lipase (WT + CER = 1420 +/- 170 U/L; KO + CER = 861 +/- 172. 3 U/L). KO mice showed reduced pancreatic NF-kappaB activation, decreased TNF-alpha tissue content, and reduced histologic alterations. Our data suggest that KO mice have an attenuated cerulein-induced pancreatitis and help to define the possible interaction between NF-kappaB activation and oxidative stress in this deleterious event.

Effect of recombinant adeno-associated virus vector-mediated vascular endothelial growth factor gene transfer on wound healing after burn injury.

OBJECTIVE: The purpose of this study was to investigate the effect of recombinant adeno-associated viral (rAAV) vector-mediated human vascular endothelial growth factor (VEGF165) transfer on experimental burn wounds. DESIGN: Randomized experiment. SETTING: Research laboratory. SUBJECTS: C57BL/6 male mice weighing 25-30 g. INTERVENTIONS: Mice were immersed in 80 degrees C water for 10 secs to achieve a partial-thickness scald burn. Animals were randomized to receive at two injection sites on the edge of the burn either 1011 copies of the rAAV-VEGF165 or the vector carrying the control and inert gene beta-galactosidase (rAAV-LacZ). On day 14 the animals were killed. Burn areas were used for histologic examination, evaluation of VEGF expression (immunohistochemistry) and VEGF wound content (enzyme-linked immunosorbent assay), determination of wound nitrite, and measurement of messenger RNA (mRNA) for endothelial and inducible nitric oxide synthase (eNOS and iNOS). MEASUREMENTS AND MAIN RESULTS: rAAV-VEGF165 increased epithelial proliferation, angiogenesis, and maturation of the extracellular matrix. Furthermore, gene transfer enhanced VEGF expression, studied by immunohistochemistry, and the wound content of the mature protein (rAAV-LacZ, 11 +/- 5 pg/wound; rAAV-VEGF165, 104 +/- 7 pg/wound). Moreover, VEGF165 gene transfer increased wound content of nitrate. Finally, rAAV-VEGF165 administration enhanced the messenger RNA for eNOS (rAAV-VEGF165, 1.1 +/- 0.2 relative amount of eNOS mRNA; rAAV-LacZ, 0.66 +/- 0.3 relative amount of eNOS mRNA) and iNOS (rAAV-VEGF165, 0.8 +/- 0.09 relative amount of iNOS mRNA; rAAV-LacZ, 0.45 +/- 0.05 relative amount of iNOS mRNA). CONCLUSION: Our study suggests that rAAV-VEGF gene transfer may be an effective therapeutic approach to improve clinical outcomes after thermal injury.

Gene transfer of IkappaBalpha limits infarct size in a mouse model of myocardial ischemia-reperfusion injury.

Nuclear factor-kappaB (NF-kappaB) plays a central role in myocardial ischemia-reperfusion (MI/R) injury. The inhibitory protein IkappaBalpha prevents its activation. We investigated the effects of adeno-associated viral vector-mediated IkappaBalpha gene transfer in MI/R injury. Male C57BL/6 mice were randomized to receive a recombinant adeno-associated virus (rAAV) encoding the gene for the NF-kappaB inhibitory protein IkappaBalpha (rAAV- IkappaBalpha) or the beta-galactosidase gene (a control and inert gene; rAAV-LacZ), both at a dose of 10(11) copies. Four weeks later anesthetized animals were subjected to total occlusion (45 minutes) of the left main coronary artery followed by 5 hours of reperfusion. MI/R produced a wide infarct size (IF/area-at-risk = 56 +/- 8%; IF/left ventricle = 44 +/- 5%) and tissue neutrophil infiltration, studied by means of elastase activity (area-at-risk = 2.5 +/- 0.4 micro g/gm tissue; infarct area = 2.9 +/- 0.6 micro g/gm tissue). Furthermore MI/R caused peak message for intercellular adhesion molecule-1 (ICAM-1) in the area-at-risk at 3 hours of reperfusion (1.2 +/- 0.4 relative amount of cardiac ICAM-1 mRNA). NF-kappaB activation was evident at 0.5 hours of reperfusion and reached its maximum increase at 2 hours of reperfusion. rAAV-IkappaBalpha injection reduced infarct size (IF/area-at-risk = 19 +/- 3%; IF/left ventricle = 10 +/- 2%; p < 0.001), blocked NF-kappaB activation, diminished cardiac ICAM-1 expression (0.4 +/- 0.02 relative amount of cardiac ICAM-1 mRNA; p < 0.001), and blunted leukocyte accumulation (area-at-risk = 0.6 +/- 0.05 micro g/gm tissue; infarct area = 0.4 +/- 0.02 micro g/gm tissue; p < 0.001). Our data indicate that rAAV-IkappaBalpha may be useful for MI/R gene therapy.