Simvastatin suppresses lung inflammatory response in a rat cardiopulmonary bypass model

Effect of Atorvastatin on PM10-induced Cytokine Production by Human Alveolar Macrophages and Bronchial Epithelial Cells

Exposure to ambient air pollution particles (PM10) has been associated with increased cardiovascular morbidity and mortality. Inhaled pollutants induce a pulmonary and systemic inflammatory response that is thought to exacerbate cardiovascular disease. The 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) have been shown to have anti-inflammatory effects that could contribute to their beneficial effect in cardiovascular disease. The aim of this study is to determine the effects of statins on PM10-induced cytokine production in human bronchial epithelial cells (HBECs) and alveolar macrophages (AMs). Primary HBECs and AMs are obtained from resected human lung. Cells are pretreated with different concentrations of atorvastatin for 24 hours and then exposed to 100 μg/mL urban air pollution particles (EHC-93). Cytokine levels (interleukin-1β, interleukin-8, granulocyte-macrophage colonystimulating factor, interleukin-6, and tumor necrosis factor-α) are measured at messenger RNA and protein levels using real-time polymerase chain reaction and bead-based multiplex immunoassay, respectively. PM10 exposure increases production of these cytokines by both cell types. Atorvastatin attenuates PM10-induced messenger RNA expression and cytokine production by AMs but not by HBECs. It is concluded that statins can modulate the PM10-induced inflammatory response in the lung by reducing mediator production by AMs.

Evaluation of the protective effects of Ganoderma atrum polysaccharide on acrylamide-induced injury in small intestine tissue of rats

This research confirmed the protective effects of Ganoderma atrum polysaccharide (PSG-1) on acrylamide (AA) induced intestinal injury in rats.

Anti-inflammatory effects of Simvastatin in patients with acute intracerebral hemorrhage in an intensive care unit

Intracerebral hemorrhage is one of the most common types of cerebrovascular disease in humans and often causes paralysis, a vegetative state and even death. Patients with acute intracerebral hemorrhage are frequently monitored in intensive care units (ICUs). Spontaneous intracerebral hemorrhage is associated with a higher rate of mortality and morbidity than other intracephalic diseases. The expression levels of inflammatory factors have important roles in inflammatory responses indicative of changes in a patient's condition and are therefore important in the monitoring and treatment of affected patients at the ICU as well as the development of therapeutic strategies for acute cerebral hemorrhage. The present study investigated the anti-inflammatory effects of Simvastatin in patients with acute intracerebral hemorrhage at an ICU, and inflammatory factors and cellular changes were systematically analyzed. The plasma concentrations of inflammatory factors, including interleukin (IL)-4, IL-6, IL-8 and IL-10, were evaluated by ELISAs. The plasma concentrations of inflammatory cellular changes were detected by using flow cytometry. The results demonstrated that after Simvastatin treatment of patients with acute cerebral hemorrhage at the ICU, the plasma concentrations of IL-4, IL-6, IL-8 and IL-10 were downregulated compared with those in placebo-treated controls. In addition, Simvastatin treatment at the ICU decreased lymphocytes, granulocytes and mononuclear cells in patients with acute cerebral hemorrhage. The levels of inflammatory factors were associated with brain edema in patients with acute cerebral hemorrhage treated at the ICU. In addition, the amount of bleeding was reduced in parallel with the inflammatory cell plasma concentration of lymphocytes, granulocytes and mononuclear cells. Importantly, Simvastatin treatment produced beneficial outcomes by improving brain edema and reducing the amount of bleeding. In conclusion, the present study demonstrated the efficacy of Simvastatin in treating acute intracerebral hemorrhage and evidenced the association between inflammatory responses and the progress of affected patients at the ICU, thereby providing insight for applying effective therapies for patients with acute intracerebral hemorrhage.

Recombinant human soluble thrombomodulin prevents acute lung injury in a rat cardiopulmonary bypass model

BACKGROUND

Cardiopulmonary bypass (CPB) may induce systemic inflammatory responses causing acute lung injury. Recombinant human soluble thrombomodulin (rTM) is reported to attenuate the secretion of inflammatory cytokines and the high-mobility group box 1 (HMGB1) protein, which is critical in controlling systemic inflammation and apoptosis. We investigated the protective effects of rTM on CPB-induced lung injury in a rat model.

METHODS

Eighteen male Sprague-Dawley rats were divided into 3 groups: sham, control (CPB alone), and rTM (CPB + rTM). CPB was conducted in the control group and the rTM group. A bolus of rTM (3 mg/kg) was administered to the rTM group rats before CPB establishment.

RESULTS

The ratio of partial pressure of arterial oxygen to the fraction of inspired oxygen only dropped markedly from before CPB in the control group (P < .001). Serum tumor necrosis factor α, interleukin (IL) 6, and HMGB1 levels were significantly higher in the control group after CPB. Pathologic study revealed significantly more severe congestion, alveolar hemorrhage, neutrophil accumulation, and edema, and the number of lung cells expressing HMGB1 increased in the control group. The mRNA expression levels of tumor necrosis factor α, IL-6, IL-1β, and HMGB1 in the control group were significantly higher than those in other groups. According to Western blot analysis, nuclear factor-κB p65 in lung tissue was significantly downregulated in the rTM group. The number of apoptotic cells and the protein of cleaved Caspase-3 were reduced in the rTM group.

CONCLUSIONS

These results suggest that rTM prevents acute lung injury through attenuating inflammation and apoptosis during and after CPB in a rat model.

Managing the inflammatory response after cardiopulmonary bypass: review of the studies in animal models

Objective

To review studies performed in animal models that evaluated therapeutic interventions to inflammatory response and microcirculatory changes after cardiopulmonary bypass.

Methods

It was used the search strategy ("Cardiopulmonary Bypass" ^(MeSH)) and ("Microcirculation" ^(MeSH) or "Inflammation" ^(MeSH) or "Inflammation Mediators" ^(MeSH)). Repeated results, human studies, non-English language articles, reviews and studies without control were excluded.

Results

Blood filters, system miniaturization, specific primers regional perfusion, adequate flow and temperature and pharmacological therapies with anticoagulants, vasoactive drugs and anti-inflammatories reduced changes in microcirculation and inflammatory response.

Conclusion

Demonstrated efficacy in animal models establishes a perspective for evaluating these interventions in clinical practice.

Simvastatin combined with antioxidant attenuates the cerebral vascular endothelial inflammatory response in a rat traumatic brain injury

Traumatic brain injury (TBI) leads to important and deleterious neuroinflammation, as evidenced by indicators such as edema, cytokine production, induction of nitric oxide synthase, and leukocyte infiltration. After TBI, cerebral vascular endothelial cells play a crucial role in the pathogenesis of inflammation. In our previous study, we proved that simvastatin could attenuate cerebral vascular endothelial inflammatory response in a rat traumatic brain injury. This purpose of this study was to determine whether simvastatin combined with an antioxidant could produce the same effect or greater and to examine affected surrogate biomarkers for the neuroinflammation after traumatic brain injury in rat. In our study, cortical contusions were induced, and the effect of acute and continuous treatment of simvastatin and vitamin C on behavior and inflammation in adult rats following experimental TBI was evaluated. The results demonstrated that simvastatin combined with an antioxidant could provide neuroprotection and it may be attributed to a dampening of cerebral vascular endothelial inflammatory response.

Simvastatin attenuates neutrophil recruitment in one-lung ventilation model in rats

PURPOSE

To investigate the anti-inflammatory effects of simvastatin in rats undergoing one-lung ventilation (OLV) followed by lung re-expansion.

METHODS

Male Wistar rats (n=30) were submitted to 1-h OLV followed by 1-h lung re-expansion. Treated group received simvastatin (40 mg/kg for 21 days) previous to OLV protocol. Control group received no treatment or surgical/ventilation interventions. Measurements of pulmonary myeloperoxidase (MPO) activity, pulmonary protein extravasation, and serum levels of cytokines and C-reactive protein (CRP) were performed.

RESULTS

OLV significantly increased the MPO activity in the collapsed and continuously ventilated lungs (31% and 52% increase, respectively) compared with control (p<0.05). Treatment with simvastatin significantly reduced the MPO activity in the continuously ventilated lung but had no effect on lung edema after OLV. The serum IL-6 and CRP levels were markedly higher in OLV group, but simvastatin treatment failed to affect the production of these inflammatory markers. Serum levels of IL-1β, TNF-α and IL-10 remained below the detection limit in all groups.

CONCLUSIONS

In an experimental one-lung ventilation model pre-operative treatment with simvastatin reduces remote neutrophil infiltration in the continuously ventilated lung. Our findings suggest that simvastatin may be of therapeutic value in OLV-induced pulmonary inflammation deserving clinical investigations.

Mesenteric endothelial dysfunction in a cardiopulmonary bypass rat model: the effect of diabetes

BACKGROUND

Diabetes is a risk factor for perioperative complications after cardiac surgery. We studied its effects on mesenteric endothelial function in a cardiopulmonary bypass (CPB) model.

METHODS

Forty Wistar rats were divided into four groups: sham (D-CPB-), cardiopulmonary bypass (D-CPB+), diabetic (D+CPB-) and diabetic that have undergone CPB (D+CPB+). Two samples of mesenteric artery were used for nitric oxide synthase (NOS) Western blot analysis, and two others for assessing contractile response and endothelium relaxations. Nitrite products and tumour necrosis factor-alpha (TNF-α) were assessed as markers of inflammatory response.

RESULTS

We observed an enhanced contractile response to the α-adrenergic agonist associated with impairment of mesenteric vasorelaxation in D+CPB+ rats. Western immunoblot analysis of D+CPB+ highlighted an additive effect of hyper-expression of inducible NOS. A significantly increased inflammatory response was observed after CPB in diabetic animals.

CONCLUSIONS

This work confirms the potential deleterious impact of diabetes on the mesenteric endothelium during CPB in cardiac surgery.

Statin therapy as prevention against development of acute respiratory distress syndrome: an observational study

OBJECTIVES

The 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors ("statins") have anti-inflammatory properties and are associated with improved outcomes in critically ill patients. We investigated whether previous statin therapy affects outcomes in patients at risk for acute respiratory distress syndrome.

DESIGN

Patients were followed-up for the primary outcome of acute respiratory distress syndrome and secondary outcomes of intensive care unit and 60-day mortality, organ dysfunction, and ventilator-free days in a secondary analysis of a prospective cohort study. Receipt of statin therapy was recorded. Propensity score matching was used to adjust for confounding by indication.

SETTING

Intensive care units at a tertiary care academic medical center.

PATIENTS

Critically ill patients (2,743) with acute respiratory distress syndrome risk factors.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Acute respiratory distress syndrome developed in 738 (26%) patients; 413 patients (15%) received a statin within 24 hrs of intensive care unit admission. Those who had received a statin within 24 hrs had a lower rate of development of acute respiratory distress syndrome (odds ratio 0.56; 95% confidence interval 0.43-0.73; p<.0001). After multivariate adjustment for potential confounders, this association remained significant (odds ratio 0.69; 95% confidence interval 0.51-0.92; p=.01). However, after propensity score matching, the association was not statistically significant (odds ratio 0.79; 95% confidence interval 0.57-1.10; p=.16). Statin use was not associated with reduced acute respiratory distress syndrome mortality, organ dysfunction, or ventilator-free days. Results of the study were presented in accordance with STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) guidelines.

CONCLUSIONS

Statin therapy at the time of intensive care unit admission was not associated with a lower rate of development of acute respiratory distress syndrome after matching for patient propensity to receive statins. Statin therapy was not associated with improvements in acute respiratory distress syndrome mortality, organ failure, or days free from mechanical ventilation.

Cardiopulmonary bypass model in the rat: a new minimal invasive model with a low flow volume

Numerous cardiopulmonary bypass (CPB) models in the rat have already been described, but these models often have an important mortality and differ a lot from human clinical conditions thus making them hardly usable. The CPB model in the rat we describe allows a femoro-femoral support CPB with a low priming volume, minimal surgical approach and excellent peroperative survival. This CPB model in the rat allows evaluating extracorporeal circulation effects.

The preventative role of curcumin on the lung inflammatory response induced by cardiopulmonary bypass in rats

BACKGROUND

Acute lung injury is a frequent complication after cardiopulmonary bypass (CPB). Recent studies have reported that NF-κB plays an important role in the pathogenesis of post-CPB pulmonary dysfunction. Several signaling pathways, including the TLR4 pathway, induce NF-κB leading to an inflammatory response. We designed this study to determine whether or not curcumin inhibits TLR4 and MyD88 protein levels and ameliorates lung inflammatory injury in a rat CPB model.

MATERIALS AND METHODS

Sprague-Dawley rats were randomly divided into the following five groups (n = 12): sham; control (CPB); vehicle; low-dose curcumin (L-Cur); and high-dose curcumin (H-Cur). The percutaneous beating heart CPB model of rat was established. Animals were pretreated with a single intraperitoneal injection of vehicle, L-Cur (50 mg/kg), or H-Cur (200 mg/kg) 2 h prior to CPB. Blood were sampled at various time points, then lung tissues and bronchoalveolar lavage fluid were harvested 24 h after CPB.

RESULTS

CPB induced a marked increase in the concentrations of interleukin-8, tumor necrosis factor-α, and matrix metalloproteinase-9 in plasma, bronchoalveolar lavage fluid, and lung tissues (P < 0.05 versus sham group), whereas curcumin pretreatment reduced these inflammatory markers. Curcumin had effective inhibitory effects on the expression of TLR4, MyD88, and NF-κB in lung tissues 24 h post-CPB (P < 0.05 versus vehicle group). Administration of curcumin remarkably decreased the lung injury score (L-Cur versus vehicle group, P = 0.024; H-Cur versus vehicle group, P = 0.013).

CONCLUSIONS

Curcumin may be an alternative therapy for protecting CPB-induced lung injury by suppressing the expression of inflammatory cytokines. This anti-inflammatory effect of curcumin is partly related to the inhibition of TLR4, MyD88, and NF-κB.

Simvastatin attenuates cardiopulmonary bypass-induced myocardial inflammatory injury in rats by activating peroxisome proliferator-activated receptor γ

Statins have been shown to downregulate the systemic inflammatory response after cardiopulmonary bypass. However, the role of statins as anti-inflammatory agents in heart tissue remains unknown. The aim of this study was to test whether statin pretreatment attenuates local inflammatory cytokines production in heart and to explore whether the underlying mechanism involves peroxisome proliferator-activated receptor (PPAR) γ. A rat model of cardiopulmonary bypass was established. The animals were pretreated with simvastatin 5 mg/kg/day or 10 mg/kg/day for 7 days before operation. The serum concentration and myocardial level of tumor necrosis factor (TNF)-α, interleukin (IL)-6, monocyte chemoattractant protein (MCP)-1 was evaluated by enzyme linked immunosorbent assay. The polymorphonuclear neutrophils accumulation in heart tissue was determined by myeloperoxidase activity assay. The activity of nuclear factor (NF)-κB and PPARγ in the heart was determined by electrophoretic mobility shift assay. The myocardial PPARγ expression was also examined by immunohistochemistry. The systemic and local TNF-α, IL-6 and MCP-1 were all significantly elevated after cardiopulmonary bypass. In contrast, simvastatin pretreatment significantly decreases the serum and myocardial expression level of above cytokines, myocardial myeloperoxidase activity and myocardial NF-κB activity. However, there was an evident increase in the activity and expression of PPARγ. In conclusion, simvastatin pretreatment not only attenuates acute systemic and local inflammatory response induced by cardiopulmonary bypass. The anti-inflammatory effect of simvastatin in myocardium may be partly related to the activation of PPARγ and inhibition of NF-κB.

Simvastatin attenuates ventilator-induced lung injury in mice

INTRODUCTION

Mechanical ventilation (MV) is a life saving intervention in acute respiratory failure without alternative. However, particularly in pre-injured lungs, even protective ventilation strategies may evoke ventilator-induced lung injury (VILI), which is characterized by pulmonary inflammation and vascular leakage. Adjuvant pharmacologic strategies in addition to lung protective ventilation to attenuate VILI are lacking. Simvastatin exhibited anti-inflammatory and endothelial barrier stabilizing properties in vitro and in vivo.

METHODS

Mice were ventilated (12 ml/kg; six hours) and subjected to simvastatin (20 mg/kg) or sham treatment. Pulmonary microvascular leakage, oxygenation, pulmonary and systemic neutrophil and monocyte counts and cytokine release in lung and blood plasma were assessed. Further, lung tissue was analyzed by electron microscopy.

RESULTS

Mechanical ventilation induced VILI, displayed by increased pulmonary microvascular leakage and endothelial injury, pulmonary recruitment of neutrophils and Gr-1high monocytes, and by liberation of inflammatory cytokines in the lungs. Further, VILI associated systemic inflammation characterized by blood leukocytosis and elevated plasma cytokines was observed. Simvastatin treatment limited pulmonary endothelial injury, attenuated pulmonary hyperpermeability, prevented the recruitment of leukocytes to the lung, reduced pulmonary cytokine levels and improved oxygenation in mechanically ventilated mice.

CONCLUSIONS

High-dose simvastatin attenuated VILI in mice by reducing MV-induced pulmonary inflammation and hyperpermeability.

Pretreatment with atorvastatin attenuates lung injury caused by high-stretch mechanical ventilation in an isolated rabbit lung model

OBJECTIVE

We hypothesized that pretreatment with atorvastatin improves alveolar capillary permeability and hemodynamics and, thus, confers protection against lung injury caused by high-stretch mechanical ventilation.

METHODS

Twenty-four isolated sets of normal rabbit lungs were utilized. Treated animals received atorvastatin (20 mg/kg body weight/day by mouth) for 3 days before surgery. Lungs were perfused constantly (300 mL/min) and ventilated for 1 hr with pressure-control ventilation at either 23 (high pressure; resulting in tidal volume approximately 22 mL/kg) or 11 (low pressure; tidal volume approximately 10 mL/kg) cm H2O peak inspiratory pressure and positive end-expiratory pressure of 3 cm H2O. Four groups were examined: high pressure-no statin, high pressure-statin pretreatment, low pressure-no statin, and low pressure-statin pretreatment.

RESULTS

The high-pressure-no statin group sustained more damage than the low-pressure groups. In high-pressure groups, lungs of statin-pretreated vs. no statin-pretreated animals sustained a significantly lower increase in ultrafiltration coefficient (an accurate marker of alveolar capillary permeability; high-pressure-statin pretreatment vs. high-pressure-no statin, -0.013 +/- 0.017 g/min/mm Hg/100g vs. 1.723 +/- 0.495 g/min/mm Hg/100g; p < .001), lower weight gain (i.e., less edema formation; 4.62 +/- 1.50 grams vs. 17.75 +/- 4.71 grams; p = .005), improved hemodynamics (i.e., lower increase in mean pulmonary artery pressure; 0.56 +/- 0.51 mm Hg vs. 5.62 +/- 1.52 mm Hg; p = .04), lower protein concentration in bronchoalveolar lavage fluid (p < .001), and fewer histologic lesions (p = .013). Apoptosis of lung parenchyma cells was not different (p = .97). There was no difference between low-pressure-statin pretreatment and low-pressure-no statin groups regarding these outcomes.

CONCLUSION

In this model, atorvastatin improves alveolar capillary permeability and hemodynamics and, thus, attenuates lung injury caused by high-stretch mechanical ventilation.

Simvastatin improves wound strength after intestinal anastomosis in the rat

BACKGROUND

Simvastatin is a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor commonly known as a cholesterol-lowering drug with additional pleiotropic effects. Also, it is demonstrated that it prevents postoperative peritoneal adhesions in rat. This study was designed to assess its effects on the healing process of colonic anastomosis.

METHODS

Thirty-two male Wistar albino rats were randomized into two groups and subjected to colonic anastomosis. The study group was treated with simvastatin and the control group received only tap water instead. The rats were killed 3 and 7 days postoperatively. Wound complications, intra-abdominal abscesses, and anastomotic leaks and stenosis were recorded. Four types of assessment were performed: bursting pressure, hydroxyproline content, histopathology, and biochemical analysis.

RESULTS

Compared to the control group, simvastatin-treated rats displayed a higher bursting pressure (p < 0.001) and anastomotic hydroxyproline content (p < 0.05). Simvastatin treatment leads to a significant decrease in malondealdehyde levels (p < 0.05) and increase in paraoxonase activity (p < 0.001) at both time points. Histopathological analysis revealed that simvastatin administration leads to a better anastomotic healing in terms of reepithelialization, decreased granuloma formation, reduced ischemic necrosis, and inflammatory infiltration to muscle layer.

CONCLUSION

Clinically relevant doses of simvastatin do not have a negative impact on colonic anastomosis but improve intestinal wound healing in rats.

Inflammatory lung injury after cardiopulmonary bypass is attenuated by adenosine A(2A) receptor activation

OBJECTIVE

Cardiopulmonary bypass has been shown to exert an inflammatory response within the lung, often resulting in postoperative pulmonary dysfunction. Several studies have shown that adenosine A(2A) receptor activation attenuates lung ischemia-reperfusion injury; however, the effect of adenosine A(2A) receptor activation on cardiopulmonary bypass-induced lung injury has not been studied. We hypothesized that specific adenosine A(2A) receptor activation by ATL313 would attenuate inflammatory lung injury after cardiopulmonary bypass.

METHODS

Adult male Sprague-Dawley rats were randomly divided into 3 groups: 1) SHAM group (underwent cannulation + heparinization only); 2) CONTROL group (underwent 90 minutes of normothermic cardiopulmonary bypass with normal whole-blood priming solution; and 3) ATL group (underwent 90 minutes of normothermic cardiopulmonary bypass with ATL313 added to the normal priming solution).

RESULTS

There was significantly less pulmonary edema and lung injury in the ATL group compared with the CONTROL group. The ATL group had significant reductions in bronchoalveolar lavage interleukin-1, interleukin-6, interferon-gamma, and myeloperoxidase levels compared with the CONTROL group. Similarly, lung tissue interleukin-6, tumor necrosis factor-alpha, and interferon-gamma were significantly decreased in the ATL group compared with the CONTROL group. There was no significant difference between the SHAM and ATL groups in the amount of pulmonary edema, lung injury, or levels of proinflammatory cytokines.

CONCLUSION

The addition of a potent adenosine A(2A) receptor agonist to the normal priming solution before the initiation of cardiopulmonary bypass significantly protects the lung from the inflammatory effects of cardiopulmonary bypass and reduces the amount of lung injury. Adenosine A(2A) receptor agonists could represent a new therapeutic strategy for reducing the potentially devastating consequences of the inflammatory response associated with cardiopulmonary bypass.