semapimod and Reperfusion-Injury

Resident macrophages within the tunica muscularis are known to play a crucial role in initiating severe inflammation in response to ischemia reperfusion injury after intestinal transplantation contributing to graft dysmotility, bacterial translocation, and possibly, acute rejection. The p38 mitogen-activated protein kinase is a key player in the signaling of proinflammatory cytokine synthesis in macrophages. Therefore, we investigated the effects of CPSI-2364, an apparent macrophage-specific inhibitor of the p38 mitogen-activated protein kinase pathway in an isogenic intestinal rat transplantation model.. Recipient and donor animals were treated perioperatively with CPSI-2364 (1 mg/kg, intravenously) or vehicle solution. Nontransplanted animals served as control. Animals were killed 30 min, 3 hr, and 18 hr after reperfusion.. CPSI-2364 treatment resulted in significantly less leukocyte infiltration and significantly improved graft motor function (18 hr). Messenger RNA expression of proinflammatory cytokines (interleukin 6) and kinetic active mediators (NO) was reduced by CPSI-2364 in the early phase after transplantation. Histologic evaluation revealed the protective effects of CPSI-2364 treatment by a significantly less destruction of mucosal integrity at all time points. Perioperative treatment with CPSI-2364 improves graft motor function through impaired inflammatory responses to ischemia reperfusion injury by inhibition of proinflammatory cytokines and suppression of nitric oxide production in macrophages.. CPSI-2364 presents as a promising complementary pharmacological approach preventing postoperative dysmotility for clinical intestinal transplantation.

Topics: Administration, Intravenous; Animals; Disease Models, Animal; Graft Rejection; Hydrazones; Interleukin-6; Intestinal Mucosa; Intestine, Small; Macrophages; Nitric Oxide; p38 Mitogen-Activated Protein Kinases; Rats; Rats, Inbred Lew; Reperfusion Injury

Ventilator-induced lung injury (VILI) contributes to the mortality in patients with acute lung injury by increasing inflammation. Recent evidence suggests that stimulation of the cholinergic antiinflammatory pathway may be an attractive way to attenuate inflammatory injury.. To determine the role of vagus nerve signaling in VILI and establish whether stimulation of the vagus reflex can mitigate VILI.. We performed bilateral vagotomy in a mouse model of high-tidal volume-induced lung injury. We performed pharmacological and electrical vagus nerve stimulation in a rat model of VILI following ischemia/reperfusion injury. To determine the contribution of the alpha 7 acetylcholine nicotinic receptor to pulmonary cell injury, we exposed human bronchial epithelial cells to cyclic stretch in the presence of specific agonist or antagonist of the alpha 7 receptor.. Vagotomy exacerbates lung injury from VILI in mice as demonstrated by increased wet-to-dry ratio, infiltration of neutrophils, and increased IL-6. Vagal stimulation attenuates lung injury in rats after ischemia/reperfusion injury ventilated with high-volume strategies. Treatment of both mice and rats with the vagus mimetic drug semapimod resulted in decreased lung injury. Vagotomy also increased pulmonary apoptosis, whereas vagus stimulation (electrical and pharmacological) attenuated VILI-induced apoptosis. In vitro studies suggest that vagus-dependent effects on inflammation and apoptosis are mediated via the α7 nicotinc acetylcholine receptor-dependent effects on cyclic stretch-dependent signaling pathways c-jun N-terminal kinase and tumor necrosis factor receptor superfamily, member 6.. Stimulation of the cholinergic antiinflammatory reflex may represent a promising alternative for the treatment of VILI.

Topics: Acute Lung Injury; Animals; Apoptosis; Cells, Cultured; Disease Models, Animal; Electric Stimulation; Humans; Hydrazones; Immunosuppressive Agents; Inflammation Mediators; Interleukin-6; Lung; Male; Mice; Mice, Inbred C57BL; Neuroimmunomodulation; Rats; Rats, Sprague-Dawley; Receptors, Nicotinic; Reperfusion Injury; Vagus Nerve; Ventilator-Induced Lung Injury

Semapimod is an experimental drug that strongly inhibits macrophages and stimulates the cholinergic anti-inflammatory pathway. The aim of this study was to evaluate the effect of semapimod on experimentally-induced acute intestinal ischemia-reperfusion syndrome in rabbits.. The experimental protocol included 16 adult male White New Zealand rabbits divided into two equal groups, A and B. Animals were subjected to 150 min of intestinal ischemia, followed by 30 min of reperfusion. At 30, 90 and 150 min after the onset of ischemia the animals in group A received i.v. placebo (2 mg/kg; Cytokine PharmaSciences Inc, PA, USA) and those of group B received i.v. semapimod (2 mg/kg; Cytokine PharmaSciences Inc, PA, USA). Blood samples were taken for plasma measurements of tumor necrosis factor-a (TNF-a), interleukin 1β (IL-1β) and interleukin 6 (IL-6) at 0, 60, 120 and 180 min after the onset of ischemia. At the same time points, wedge intestinal biopsies were taken for histopathological evaluation of mucosal injury. All data were analyzed by the non-parametric Mann-Whitney test as appropriate. The power effect of Semapimod was evaluated by mixed between-within Anova statistical analysis.. Measurements of TNF-a and IL-1β levels showed significant differences between groups A and B at 120 min (P=0.004 and P=0.003 respectively) and at 180 min (P=0.001 and p<0.005 respectively). IL-6 values were lower in animals of group B but the differences were not significant. Intestinal mucosal injuries were significantly milder in animals of group B at 120 and 180 min. Semapimod minimized intestinal mucosa injury and reduced the systemic inflammatory response during acute intestinal ischemia-reperfusion. Further studies are required to investigate the possible value of semapimod as a new pretreatment modality in acute vascular abdomen.

Topics: Analysis of Variance; Animals; Anti-Inflammatory Agents; Biopsy; Disease Models, Animal; Gastrointestinal Agents; Hydrazones; Inflammation Mediators; Injections, Intravenous; Interleukin-1beta; Interleukin-6; Intestinal Mucosa; Intestines; Male; Mesenteric Vascular Occlusion; Rabbits; Reperfusion Injury; Time Factors; Tumor Necrosis Factor-alpha

Despite the advent of dialysis, survival with acute renal failure when associated with multiorgan failure is poor. The development of lung injury after shock or visceral ischemia has been shown; however, the effects of isolated renal ischemia/reperfusion injury (IRI) on the lungs are unclear. We hypothesized that isolated renal IRI could alter pulmonary vascular permeability (PVP) and that macrophages could be important mediators in this response.. Rats (N = 5 per group) underwent renal ischemia for 30 minutes, followed by reperfusion. Lung vascular permeability was evaluated by quantitation of Evans blue dye extravasation from vascular space to lung parenchyma at 1, 24, 48, or 96 hours after reperfusion. Serum was collected for blood urea nitrogen and creatinine at each time point. To examine the role of the macrophage, the macrophage pacifant CNI-1493, which inhibits the release of macrophage-derived inflammatory products, was administered in a blinded fashion during renal IRI.. PVP was significantly (P < 0.05) increased at 24 hours and peaked at 48 hours after IRI compared with shams as well as baseline levels. PVP after IRI became similar to shams after 96 hours. This correlated with increases in blood urea nitrogen and creatinine at similar time points. At 48 hours, CNI-1493 significantly abrogated the increase in PVP compared with IRI alone. However, CNI-1493 did not alter the course of the acute renal failure. Pulmonary histology demonstrated interstitial edema, alveolar hemorrhage, and red blood cell sludging after renal IRI, which was partially attenuated by CNI-1493.. Increased PVP develops after isolated renal IRI, and macrophage-derived products are mediators in this response. These findings have implications for understanding the mechanisms underlying respiratory dysfunction associated with acute renal failure.

Topics: Animals; Capillary Permeability; Cytokines; Disease Models, Animal; Hydrazones; Kidney; Lung; Lung Injury; Macrophages, Alveolar; Rats; Reperfusion Injury