Simvastatin Decreases Nitric Oxide Overproduction and Reverts the Impaired Vascular Responsiveness Induced by Endotoxic Shock in Rats

Vascular leak in sepsis: physiological basis and potential therapeutic advances

Sepsis is a life-threatening condition characterised by endothelial barrier dysfunction and impairment of normal microcirculatory function, resulting in a state of hypoperfusion and tissue oedema. No specific pharmacological therapies are currently used to attenuate microvascular injury. Given the prominent role of endothelial breakdown and microcirculatory dysfunction in sepsis, there is a need for effective strategies to protect the endothelium. In this review we will discuss key mechanisms and putative therapeutic agents relevant to endothelial barrier function.

Prevention of Contrast-Induced Nephropathy After Cardiovascular Catheterization and Intervention With High-Dose Strong Statin Therapy in Japan - The PREVENT CINC-J Study

BACKGROUND

Previous studies have reported that high-dose strong statin therapy reduces the incidence of contrast-induced nephropathy (CIN) in statin naïve patients; however, the efficacy of high-dose strong statins for preventing CIN in real-world clinical practice remains unclear. The aim of this study was to evaluate the efficacy of strong statin therapy in addition to fluid hydration for preventing CIN after cardiovascular catheterization.

METHODS AND RESULTS

This prospective, multicenter, randomized controlled trial included 420 patients with chronic kidney disease who underwent cardiovascular catheterization. They were assigned to receive high-dose pitavastatin (4 mg/day × 4 days) on the day before and of the procedure and 2 days after the procedure (Statin group, n=213) or no pitavastatin (Control group, n=207). Isotonic saline hydration combined with a single bolus of sodium bicarbonate (20 mEq) was scheduled for administration to all patients. In the control group, statin therapy was continued at the same dose as that before randomization. CIN was defined as a ≥0.5 mg/dL increase in serum creatinine or ≥25% above baseline at 48 h after contrast exposure. Before randomization, 83% of study participants were receiving statin treatment. The statin group had a higher incidence of CIN than the control group (3.0% vs. 0%, P=0.01). The 12-month rate of major adverse cardiovascular events was similar between the 2 groups.

CONCLUSIONS

High-dose pitavastatin increases the incidence of CIN in this study population.

Atorvastatin prevents the development of diabetic neuropathic nociception by possible involvement of nitrergic system

AIMS

Diabetic neuropathy has been identified as a common complication caused by diabetes. However, its pathophysiological mechanisms are not fully understood yet. Statins, also known as HMG-CoA reductase inhibitors, alleviate the production of cholesterol. Despite this cholesterol-reducing effect of statins, several reports have demonstrated their beneficial properties in neuropathic pain. In this study, we used streptozotocin (STZ)-induced diabetic model to investigate the possible role of nitric oxide (NO) in the antineuropathic-like effect of atorvastatin.

METHODS

Diabetes was induced by a single injection of STZ. Male rats orally received different doses of atorvastatin for 21 days. To access the neuropathy process, the thermal threshold of rats was assessed using hot plate and tail-flick tests. Moreover, sciatic motor nerve conduction velocity (MNCV) studies were performed. To assess the role of nitric oxide, N(G)-nitro-L-arginine methyl ester (L-NAME), aminoguanidine (AG), and 7-nitroindazole (7NI) were intraperitoneally administered along with some specific doses of atorvastatin.

KEY FINDINGS

Atorvastatin significantly reduced the hyperalgesia in diabetic rats. L-NAME pretreatment with atorvastatin showed the antihyperalgesic effect, suggesting the possible involvement of the NO pathway in atorvastatin protective action. Furthermore, co-administration of atorvastatin with AG and 7NI resulted in a significant increase in pain threshold in diabetic rats.

SIGNIFICANCE

Our results reveal that the atorvastatin protective effect on diabetic neuropathy is mediated at least in a part via the nitric oxide system.

Exploring the pathophysiology of post-sepsis syndrome to identify therapeutic opportunities

Sepsis is a major health problem worldwide. As the number of sepsis cases increases, so does the number of sepsis survivors who suffer from “post-sepsis syndrome” after hospital discharge. This syndrome involves deficits in multiple systems, including the immune, cognitive, psychiatric, cardiovascular, and renal systems. Combined, these detrimental consequences lead to rehospitalizations, poorer quality of life, and increased mortality. Understanding the pathophysiology of these issues is crucial to develop new therapeutic opportunities to improve survival rate and quality of life of sepsis survivors. Such novel strategies include modulating the immune system and addressing mitochondrial dysfunction. A sepsis follow-up clinic may be useful to identify long-term health issues associated with post-sepsis syndrome and evaluate existing and novel strategies to improve the lives of sepsis survivors.

Statins and gastroesophageal reflux disease: A meta-analysis

Background/Objectives

Gastroesophageal reflux disease (GERD) is one of the common gastrointestinal disorders worldwide. Recent epidemiologic studies have suggested that use of statins may lower the risk of GERD although the results from different studies were inconsistent. This systematic review and meta-analysis were conducted with the aim to summarize all available data.

Methods

A systematic literature review was performed using MEDLINE and EMBASE database from inception to December 2017. Cohort, case-control, and cross-sectional studies that compared the risk of GERD among statin users versus nonusers were included. Pooled odds ratio (OR) and 95% confidence interval (CI) were calculated using a random-effect, generic inverse variance method.

Results

A total of 4 studies (1 case control, 1 cohort, and 2 cross-sectional studies) with 14,505 participants met the eligibility criteria and were included in the meta-analysis. The risk of GERD among statin users was numerically lower than nonusers with the pooled OR of 0.89 but the result did not achieve statistical significance (95% CI, 0.60-1.33). The statistical heterogeneity in this study was moderate (I² = 54%).

Conclusions

The current meta-analysis found that the risk of GERD was numerically lower among statin users although the pooled result did not reach statistical significance. Therefore, more studies are still needed to further clarify this potential benefit of statins.

Simvastatin preparations promote PDGF-BB secretion to repair LPS-induced endothelial injury through the PDGFRβ/PI3K/Akt/IQGAP1 signalling pathway

Endothelial barrier dysfunction is a critical pathophysiological process of sepsis. Impaired endothelial cell migration is one of the main reasons for endothelial dysfunction. Statins may have a protective effect on endothelial barrier function. However, the effect and mechanism of statins on lipopolysaccharide (LPS)‐induced endothelial barrier dysfunction remain unclear. Simvastatin (SV) was loaded in nanostructured lipid carriers to produce SV nanoparticles (SV‐NPs). Normal SV and SV‐NPs were used to treat human umbilical vein vascular endothelial cells (HUVECs) injured by LPS. Barrier function was evaluated by monitoring cell monolayer permeability and transendothelial electrical resistance, and cell migration ability was measured by a wound healing assay. LY294002 and imatinib were used to inhibit the activity of PI3K/Akt and platelet‐derived growth factor receptor (PDGFR) β. IQ‐GTPase‐activating protein 1 (IQGAP1) siRNA was used to knockdown endogenous IQGAP1, which was used to verify the role of the PDGFRβ/PI3K/Akt/IQGAP1 pathway in SV/SV‐NPs‐mediated barrier protection in HUVECs injured by LPS. The results show that SV/SV‐NPs promoted the migration and decreased the permeability of HUVECs treated with LPS, and the efficacy of the SV‐NPs exceeded that of SV significantly. LY294002, imatinib and IQGAP1 siRNA all suppressed the barrier protection of SV/SV‐NPs. SV/SV‐NPs promoted the secretion of platelet‐derived growth factor‐BB (PDGF‐BB) and activated the PDGFRβ/PI3K/Akt/IQGAP1 pathway. SV preparations restored endothelial barrier function by restoring endothelial cell migration, which is involved in the regulation of the PDGFRβ/PI3K/Akt/IQGAP1 pathway and PDGF‐BB secretion. As an appropriate formulation for restoring endothelial dysfunction, SV‐NPs may be more effective than SV.

Meta-analysis of rosuvastatin efficacy in prevention of contrast-induced acute kidney injury

Background

Contrast-induced nephropathy (CIN) is a complication after the intravascular administration of a contrast medium injection. Previous studies have investigated statins as therapy for CIN due to its positive results in the prevention of contrast-induced acute kidney injury (CI-AKI). Nevertheless, the beneficial effects of rosuvastatin pretreatment in preventing CIN in patients with acute coronary syndromes still remain controversial. In this study, we performed a meta-analysis of randomized controlled trials (RCTs) to evaluate the beneficial impact of rosuvastatin in the prevention of CI-AKI in acute coronary syndrome patients.

Methods

PubMed, Embase, and Cochrane library were searched, for RCTs, updated on January 2018. The method was to evaluate rosuvastatin prior to angiography for the prevention of CI-AKI in patients undergoing coronary angiography, of which the main outcome was the incidence of CIN.

Results

A total of five RCTs were included in this analysis. Patients treated with rosuvastatin prior to invasive angiography had a significantly lower incidence of CI-AKI than controls (odds ratio [OR]: 0.53, 95% CI: 0.40–0.71, P<0.0001). Moreover, the subgroup analysis also showed that the benefit of rosuvastatin for patients with chronic kidney disease (OR: 0.49, 95% CI: 0.26–0.92, P=0.03) and diabetes mellitus (OR: 0.56, 95% CI: 0.38–0.83, P=0.004) which was consistent in compared with the respective control groups.

Conclusion

The findings of this meta-analysis suggest that the preoperative rosuvastatin treatment significantly reduces the risk of renal insufficiency of CIN in at-risk patients with chronic kidney disease or diabetes mellitus. Additional studies are needed to identify at-risk patients, provide optimum dose peri-procedural treatment, and reduce the incidence of CIN.

Perioperative Statin Use and Acute Kidney Injury in Patients Undergoing Partial Nephrectomy

BACKGROUND

Statin use is widespread among the general population. Data suggest a potentially beneficial effect of statin therapy on renal function following surgery. The impact of statins on post-partial nephrectomy (PN) renal function is unknown. We hypothesized that perioperative statin use may be associated with reduced rates of acute kidney injury (AKI) in patients undergoing PN.

OBJECTIVES

To evaluate the effect of perioperative statin use on AKI rates in patients undergoing PN.

MATERIALS & METHODS

1,056 patients undergoing PN were identified from a prospectively-maintained institutional renal mass database. Exclusion criteria included lack of preoperative serum creatinine (Cr), concurrent surgeries, and those with baseline Cr <0.4. The binary outcome was AKI, defined using modified Kidney Disease Improving Global Outcomes (KDIGO) criteria. Chi-Square and Cochran-Armitage trend tests were used to evaluate the strength of associations. A multivariate logistic regression model was used to determine predictors of AKI.

RESULTS

Statin use was reported by n = 346 (32.8%) patients at the time of surgery. Univariate analysis demonstrated that statin use was associated with an increased risk of AKI following PN (OR 1.38, CI 1.01-1.88, p = 0.04). On multivariate analysis, statin use was no longer associated with AKI following PN (OR 1.09, CI 0.76-1.56, p = 0.65). Gender, BMI, comorbidity index, hypertension, surgical approach, ischemia temperature/time, and nephrometry "R" score were all independently associated with AKI.

CONCLUSIONS

Perioperative statin use at the time of PN was not associated with rates of post-operative AKI. Prospective studies are needed to elucidate the effects of statins on functional outcomes following PN.

Contrast-Induced Acute Kidney Injury Is Associated With Long-Term Adverse Events in Patients With Acute Coronary syndrome

Contrast-induced acute kidney injury (CI-AKI) is associated with increased mortality, morbidity, and prolonged hospitalization. Patients with acute coronary syndrome (ACS) have a 3-fold higher risk of developing CI-AKI. The aim of our study was to evaluate the predictors of CI-AKI and long-term prognosis in patients with ACS who developed CI-AKI (1083 patients were enrolled). Contrast-induced acute kidney injury was defined as an increase of ≥0.5 mg/dL and/or an increase of ≥25% of pre-percutaneous coronary intervention (PCI) to post-PCI serum creatinine levels within 48 to 72 hours after the procedure. Primary end point was defined as all-cause mortality, myocardial infarction, and cerebrovascular event at long-term follow-up (36 ± 12 months). Contrast-induced acute kidney injury occurred in 178 (16.4%) of the 1083 patients. The primary end points were significantly high in patients with ACS who developed CI-AKI ( P < .001). The occurrence of CI-AKI was identified as an independent predictor of primary end point. Risk of CI-AKI development was more frequently seen in patients with ACS. Also, patients who developed CI-AKI have worse prognosis at long-term follow-up. Additional preventive treatment strategies need to be developed in this group of patients.

Brain Oxidative Stress During Experimental Sepsis Is Attenuated by Simvastatin Administration

During sepsis, brain damage is associated with oxidative stress due to overproduction of reactive oxygen species (ROS). Although there are recent reports about the benefits of statins in experimental sepsis and endotoxemia in peripheral organs, little is known about their effects in the CNS. Here, we investigated the antioxidant properties of simvastatin and its possible neuroprotective role during experimental sepsis. Male Wistar rats (250-300 g) were submitted to cecal ligation and puncture (CLP, n = 34) or remained as non-manipulated (naive, n = 34). Both groups were treated by gavage with simvastatin (20 mg/kg) or an equivalent volume of saline. The animals submitted to CLP were treated 4 days before and 48 h after surgery. One animal group was decapitated and the blood and brain were collected to quantify plasma levels of cytokines and assess astrogliosis and apoptosis in the prefrontal cortex and hippocampus. Another group was perfused with PBS (0.01 M), and the same brain structures were dissected to analyze oxidative damage. The CLP rats treated with simvastatin showed a reduction in nitric oxide (P < 0.05), IL1-β (P < 0.001), IL-6 (P < 0.01), and TBARS levels (P < 0.001) and an increase in catalase activity (P < 0.01), citrate synthase enzyme (P < 0.05), and normalized GSH/GSSG ratio. In addition, the histopathological analysis showed a reduction (P < 0.001) in reactive astrocytes and caspase 3-positive apoptotic cells. The results suggest a possible neuroprotective effect of simvastatin in structures responsible for spatial learning and memory and indicate the need for behavioral studies evaluating the impact on cognitive damage, as frequently seen in patients surviving sepsis.

Chronic Heart Failure and Inflammation

As a greater proportion of patients survive their initial cardiac insult, medical systems worldwide are being faced with an ever-growing need to understand the mechanisms behind the pathogenesis of chronic heart failure (HF). There is a wealth of information about the role of inflammatory cells and pathways during acute injury and the reparative processes that are subsequently activated. We discuss the different causes that lead to chronic HF development and how the sum of initial inflammatory and reparative responses only sets the trajectory for disease progression. Unfortunately, comparatively little is known about the contribution of the immune system once the trajectory has been set, and chronic HF has been established—which clinically represents the majority of patients. It is known that chronic HF is associated with circulating inflammatory cytokines that can predict clinical outcomes, yet the causative role inflammation plays in disease progression is not well defined, and the majority of clinical trials that target aspects of inflammation in patients with chronic HF have largely been negative. This review will present what is currently known about inflammation in chronic HF in both humans and animal models as a means to highlight the gap in our knowledge base that requires further examination.

Nitric oxide and fever: immune-to-brain signaling vs. thermogenesis in chicks

Nitric oxide (NO) plays a role in thermogenesis but does not mediate immune-to-brain febrigenic signaling in rats. There are suggestions of a different situation in birds, but the underlying evidence is not compelling. The present study was designed to clarify this matter in 5-day-old chicks challenged with a low or high dose of bacterial LPS. The lower LPS dose (2 μg/kg im) induced fever at 3–5 h postinjection, whereas 100 μg/kg im decreased core body temperature (Tc) (at 1 h) followed by fever (at 4 or 5 h). Plasma nitrate levels increased 4 h after LPS injection, but they were not correlated with the magnitude of fever. The NO synthase inhibitor ( NG-nitro-l-arginine methyl ester, l-NAME; 50 mg/kg im) attenuated the fever induced by either dose of LPS and enhanced the magnitude of the Tc reduction induced by the high dose in chicks at 31–32°C. These effects were associated with suppression of metabolic rate, at least in the case of the high LPS dose. Conversely, the effects of l-NAME on Tc disappeared in chicks maintained at 35–36°C, suggesting that febrigenic signaling was essentially unaffected. Accordingly, the LPS-induced rise in the brain level of PGE2 was not affected by l-NAME. Moreover, l-NAME augmented LPS-induced huddling, which is indicative of compensatory mechanisms to run fever in the face of attenuated thermogenesis. Therefore, as in rats, systemic inhibition of NO synthesis attenuates LPS-induced fever in chicks by affecting thermoeffector activity and not by interfering with immune-to-brain signaling. This may constitute a conserved effect of NO in endotherms.

Oxidative-Nitrosative Stress and Myocardial Dysfunctions in Sepsis: Evidence from the Literature and Postmortem Observations

BACKGROUND

Myocardial depression in sepsis is common, and it is associated with higher mortality. In recent years, the hypothesis that the myocardial dysfunction during sepsis could be mediated by ischemia related to decreased coronary blood flow waned and a complex mechanism was invoked to explain cardiac dysfunction in sepsis. Oxidative stress unbalance is thought to play a critical role in the pathogenesis of cardiac impairment in septic patients.

AIM

In this paper, we review the current literature regarding the pathophysiology of cardiac dysfunction in sepsis, focusing on the possible role of oxidative-nitrosative stress unbalance and mitochondria dysfunction. We discuss these mechanisms within the broad scenario of cardiac involvement in sepsis.

CONCLUSIONS

Findings from the current literature broaden our understanding of the role of oxidative and nitrosative stress unbalance in the pathophysiology of cardiac dysfunction in sepsis, thus contributing to the establishment of a relationship between these settings and the occurrence of oxidative stress. The complex pathogenesis of septic cardiac failure may explain why, despite the therapeutic strategies, sepsis remains a big clinical challenge for effectively managing the disease to minimize mortality, leading to consideration of the potential therapeutic effects of antioxidant agents.

Endothelial nitric oxide synthase in the microcirculation

Endothelial nitric oxide synthase (eNOS, NOS3) is responsible for producing nitric oxide (NO)--a key molecule that can directly (or indirectly) act as a vasodilator and anti-inflammatory mediator. In this review, we examine the structural effects of regulation of the eNOS enzyme, including post-translational modifications and subcellular localization. After production, NO diffuses to surrounding cells with a variety of effects. We focus on the physiological role of NO and NO-derived molecules, including microvascular effects on vessel tone and immune response. Regulation of eNOS and NO action is complicated; we address endogenous and exogenous mechanisms of NO regulation with a discussion of pharmacological agents used in clinical and laboratory settings and a proposed role for eNOS in circulating red blood cells.

The Effects of Statins on Infections after Stroke or Transient Ischemic Attack: A Meta-Analysis

Background

Previous studies have reported that statins can prevent infections, and these findings were ascribed to the anti-inflammatory and immunomodulatory properties of statins. However, the effects of statins on the risk of infection after stroke or transient ischemic attack (TIA) remain controversial. The aim of this study was to evaluate the relationship between statins and the risk of infection after stroke or TIA by means of a meta-analysis.

Methodology and Findings

Studies were found by searching major electronic databases using key terms and restricting the results to studies published in English language and human studies. Pooled odds ratio (OR) for the association between infection and statins were analyzed using Stata software. A total of five studies that included 8,791 stroke or TIA patients (3,269 patients in the statin use group and 5,522 in the placebo group) were eligible and abstracted. Pooled analysis demonstrated that statins did not significantly affect the incidence of infection after stroke or TIA compared with a placebo (OR 0.819, 95% CI 0.582–1.151, I² = 64.2%, p= 0.025). Sensitivity analyses showed that the removal of any single study did not significantly affect the pooled OR. Cumulative meta-analysis showed that the incidence of infection did not vary by publication year. No statistical evidence of publication bias was found among the studies selected, based on the results of Egger’s (p = 1.000) and Begg’s (p = 0.762) tests.

Conclusions

This meta-analysis does not support the hypothesis that statins reduce the risk of infections in stroke or TIA patients.

Continuation of Statin Therapy and Vasopressor Use in Septic Shock

Background: Studies have evaluated the use of statins in sepsis; however, no human studies have explored their effect on vasopressor requirements in septic shock. Objective: The primary objective was to determine the effect of prehospital statin continuation on duration of vasopressor therapy in patients with septic shock. Secondary objectives included maximum and average vasopressor dose and in-hospital mortality. Methods: This was a retrospective, institutional board–approved, observational cohort study in a community teaching hospital; 119 adult intensive care unit (ICU) patients with an ICD-9 code for septic shock and prehospital statin therapy were evaluated. Multivariate analyses were performed to address confounders. Results: Of the 1229 patients screened, 119 (10%) met inclusion criteria; 73 patients (61%) had a statin continued within 24 hours of ICU admission. Crude analysis demonstrated no difference in vasopressor duration in the statin versus no statin group (3.3 vs 4.8 days; P = 0.21). There was no difference in either maximum (17.9 ± 16.1 vs 23.8 ± 21.7 µg/min norepinephrine equivalents [NEQs]; P = 0.1) or average vasopressor dose (9.5 ± 8.4 vs 12.1 ± 11.5 µg/min NEQ; P = 0.17). There was a decrease in mortality in the statin patients (43% vs 67 %; P = 0.05). On adjustment for potential confounders, there was no difference in any outcome, with a persistent trend toward lower mortality in the statin group. Conclusion: Continuation of prehospital statin therapy decreased neither duration nor dose of vasopressors in patients with septic shock but yielded a trend toward decreased mortality.

Atorvastatin reduces endotoxin-induced microvascular inflammation via NOSII

In a lipopolysaccharide (LPS)-induced rat model of sepsis (endotoxaemia), we previously demonstrated that pravastatin reduced microvascular inflammation via increased endothelial nitric oxide synthase III (NOSIII). This study aimed to determine whether atorvastatin, the most commonly used statin for lowering cholesterol, exerted beneficial pleiotropic effects via a similar mechanism. The mesenteric microcirculation of anaesthetised male Wistar rats (308 ± 63 g, n = 54) was prepared for fluorescent intravital microscopy. Over 4 h, animals received intravenous (i.v.) administration of either saline, LPS (150 μg kg(-1) h(-1)) or LPS + atorvastatin (200 μg kg(-1) s.c., 18 and 3 h before LPS), with/without the non-specific NOS inhibitor L-NG-Nitroarginine Methyl Ester (L-NAME) (10 μg kg(-1) h(-1)) or NOSII-specific inhibitor 1400 W (20 μg kg(-1) min(-1)). LPS decreased mean arterial blood pressure (MAP) (4 h, control 113 ± 20 mmHg; LPS 70 ± 23 mmHg), being reversed by atorvastatin (105 ± 3 mmHg) (p < 0.05). LPS also increased macromolecular leak measured after 100 mg kg(-1) of i.v FITC-BSA (arbitrary grey level adjacent to venules), which again was attenuated by atorvastatin (control 1.9 ± 4.0; LPS 12.0 ± 2.4; LPS + atorvastatin 4.5 ± 2.2) (p < 0.05). Furthermore, immunohistochemistry identified that atorvastatin decreased LPS-induced upregulation of endothelial cell NOSII expression, but NOSIII was unchanged in all groups. Atorvastatin improved MAP and reduced microvascular inflammation during endotoxaemia, associated with a reduction of pro-inflammatory NOSII. This differs from previous studies, whereby pravastatin increased expression of NOSIII. Thus preoperative statins have beneficial anti-inflammatory effects during endotoxaemia, but careful consideration must be given to the specific statin being used.

Clinical features and patient management of Lujo hemorrhagic fever

BACKGROUND

In 2008 a nosocomial outbreak of five cases of viral hemorrhagic fever due to a novel arenavirus, Lujo virus, occurred in Johannesburg, South Africa. Lujo virus is only the second pathogenic arenavirus, after Lassa virus, to be recognized in Africa and the first in over 40 years. Because of the remote, resource-poor, and often politically unstable regions where Lassa fever and other viral hemorrhagic fevers typically occur, there have been few opportunities to undertake in-depth study of their clinical manifestations, transmission dynamics, pathogenesis, or response to treatment options typically available in industrialized countries.

METHODS AND FINDINGS

We describe the clinical features of five cases of Lujo hemorrhagic fever and summarize their clinical management, as well as providing additional epidemiologic detail regarding the 2008 outbreak. Illness typically began with the abrupt onset of fever, malaise, headache, and myalgias followed successively by sore throat, chest pain, gastrointestinal symptoms, rash, minor hemorrhage, subconjunctival injection, and neck and facial swelling over the first week of illness. No major hemorrhage was noted. Neurological signs were sometimes seen in the late stages. Shock and multi-organ system failure, often with evidence of disseminated intravascular coagulopathy, ensued in the second week, with death in four of the five cases. Distinctive treatment components of the one surviving patient included rapid commencement of the antiviral drug ribavirin and administration of HMG-CoA reductase inhibitors (statins), N-acetylcysteine, and recombinant factor VIIa.

CONCLUSIONS

Lujo virus causes a clinical syndrome remarkably similar to Lassa fever. Considering the high case-fatality and significant logistical impediments to controlled treatment efficacy trials for viral hemorrhagic fever, it is both logical and ethical to explore the use of the various compounds used in the treatment of the surviving case reported here in future outbreaks. Clinical observations should be systematically recorded to facilitate objective evaluation of treatment efficacy. Due to the risk of secondary transmission, viral hemorrhagic fever precautions should be implemented for all cases of Lujo virus infection, with specialized precautions to protect against aerosols when performing enhanced-risk procedures such as endotracheal intubation.

Effect of High Dose Rosuvastatin Loading before Percutaneous Coronary Intervention on Contrast-Induced Nephropathy

Background and Objectives

Contrast-induced nephropathy (CIN) is associated with increased morbidity and mortality. This observational, non-randomized study evaluated the effect of rosuvastatin loading before percutaneous coronary intervention (PCI) on the incidence of CIN in patients with acute coronary syndrome (ACS).

Subjects and Methods

A total of 824 patients who underwent PCI for ACS were studied (408 patients in the statin group=40 mg rosuvastatin loading before PCI; 416 patients of control group=no statin pretreatment). Serum creatinine concentrations were measured before and 24 and 48 hours after PCI. The primary endpoint was development of CIN defined as an increase in serum creatinine concentration of ≥0.5 mg/dL or ≥25% above baseline within 72 hours after PCI.

Results

The incidence of CIN was significantly lower in the statin group than that in the control group (18.8% vs. 13.5%, p=0.040). The maximum percent changes in serum creatinine and estimated glomerular filtration rate in the statin group within 48 hours were significantly lower than those in the control group (5.84±22.59% vs. 2.43±24.49%, p=0.038; -11.44±14.00 vs. -9.51±13.89, p=0.048, respectively). The effect of rosuvastatin on preventing CIN was greater in the subgroups of patients with diabetes, high-dose contrast medium, multivessel stents, high baseline C-reactive protein, and myocardial infarction. A multivariate analysis revealed that rosuvastatin loading was independently associated with a decreased risk for CIN (odds ratio, 0.64; 95% confidence interval, 0.43-0.95, p=0.026).

Conclusion

High-dose rosuvastatin loading before PCI was associated with a significantly lower incidence of CIN in patients with ACS.

Effect of induced mild hypothermia on two pro-inflammatory cytokines and oxidative parameters during experimental acute sepsis

This study aimed to determine the effect of induced mild hypothermia (34°C) on the production of two cytokines (interleukin (IL-6) and tumor necrosis factor (TNF)alpha) and reactive nitrogen and oxygen species in plasma and the heart of acutely septic rats. After anesthesia and in conditions of normothermia (38°C) or mild hypothermia (34°C), acute sepsis was induced by cecal ligation and perforation. For each temperature three groups were formed: (1) baseline (blood sample collected at T0 hour), (2) sham (blood sample at T4 hours) and (3) septic (blood sample at T4 hours). At either temperature sepsis induced a significant increase in plasma IL-6, TNF-alpha and HO• concentration, compared with the sham groups (P≤0.016). Compared with the normothermic septic group, septic rats exposed to mild hypothermia showed a mild decrease in TNF-alpha concentration (104±50 pg/ml vs. 215±114 pg/ml; P>0.05) and a significant decrease in IL-6 (1131±402 pg/ml vs. 2494±691 pg/ml, P=0.038). At either temperature sepsis induced no enhancement within the heart of lipoperoxidation (malondialdehyde content) or antioxidant activities (superoxide dismutase and catalase). In conclusion, during acute sepsis, induced mild hypothermia appears to reduce some pro-inflammatory and oxidative responses. This may, in part, explain the beneficial effect of hypothermia on survival duration of septic rats.

Comparing the anti-inflammatory effects of Simvastatin and Rosuvastatin by measuring IL-1β, IL-6 and TNF-α levels using a murinic caecal ligation and puncture induced sepsis model / Compararea efectelor anti-inflamatoare ale Simvastatinei și Rosuvastatinei măsurând nivelele serice ale IL-1β, IL-6 si TNF-α folosind un model de sepsis la șobolan indus prin ligatură și puncție cecală

Background: Sepsis is a systemic host response to an infection which may evolve into severe sepsis and septic shock. It raises many health care related concerns around the world, carrying almost 30% mortality rates and a high financial burden. The disease is characterized by the triggering of some inflammatory pathways that are ultimately proven deleterious to the host organism. Although antibiotics, fluid administration, vasopressor therapy and infectious source control remain the recommended management strategies, emerging scientific data proposes statins as a new line of treatment. These drugs were first introduced in clinical practice for their cholesterol-lowering effect but the inhibition of HMG-CoA reductase and cholesterol biosynthetic pathway exhibits some less studied effects generally referred to as pleiotropic: anti-inflammatory, antithrombotic, immunomodulatory and antioxidant properties. Objective: To asses and compare the anti-inflammatory effect of two statins - Simvastatin and Rosuvastatin - measuring blood levels of IL-1β, IL-6 and TNFα using a previously described murinic model of sepsis. Methods: We compiled four groups (C, n=7; SEP, SV, RV, n=8). Statins were administered in two doses 18 and 3 hours before surgical intervention. Sepsis was induced using the caecal ligation and puncture technique. Blood samples were obtained by venepuncture from each subject in day 1, 4, 7 and 14 (the last samples were obtained by cardiac puncture). Complete blood count, Procalcitonin, IL-1β, IL-6 and TNF-α levels were assessed. Results: White blood cell counts differed across the groups showing a higher count for the septic but untreated group. Procalcitonin reacted in all septic groups but both statin treated groups had lower levels when compared to untreated group. IL-1β levels were higher in the Rosuvastatin treated group. IL-6 levels were more heterogeneously dispersed but higher levels were noticed in the untreated septic group. The Simvastatin treated group had higher levels compared to the Rosuvastatin treated one. TNFα levels were higher in the septic untreated group and in the Rosuvastatin treated one. For the Simvastatin treated subjects, the level of TNFα was similar with the control group. Conclusion: We concluded that both drugs showed anti-inflammatory effects on the murinic CLP-induced sepsis model. Between the two, Simvastatin had greater impact by lowering blood levels of established pro-inflammatory markers.

Molecular contributions to neurovascular unit dysfunctions after brain injuries: lessons for target-specific drug development

The revised 'expanded' neurovascular unit (eNVU) is a physiological and functional unit encompassing endothelial cells, pericytes, smooth muscle cells, astrocytes and neurons. Ischemic stroke and traumatic brain injury are acute brain injuries directly affecting the eNVU with secondary damage, such as blood-brain barrier (BBB) disruption, edema formation and hypoperfusion. BBB dysfunctions are observed at an early postinjury time point, and are associated with eNVU activation of proteases, such as tissue plasminogen activator and matrix metalloproteinases. BBB opening is accompanied by edema formation using astrocytic AQP4 as a key protein regulating water movement. Finally, nitric oxide dysfunction plays a dual role in association with BBB injury and dysregulation of cerebral blood flow. These mechanisms are discussed including all targets of eNVU encompassing endothelium, glial cells and neurons, as well as larger blood vessels with smooth muscle. In fact, the feeding blood vessels should also be considered to treat stroke and traumatic brain injury. This review underlines the importance of the eNVU in drug development aimed at improving clinical outcome after stroke and traumatic brain injury.

Acute kidney injury in statin initiators

PURPOSE

Statins are widely used for preventing cardiovascular disease, yet recent reports suggest an increased risk of acute kidney injury (AKI). We estimated the one-year risk of AKI associated with statin initiation and determined the comparative safety of individual statin formulations.

METHODS

We performed a cohort study in insurance billing data from commercial and Medicare insurance plans in the United States for the years 2000-2010. We identified statin initiators and non-users with histories of medication use and healthcare utilization. AKI diagnosis codes were identified in the one year following the index date. We estimated hazard ratios (HR) and 95% confidence intervals (CI) with adjusted and propensity score (PS)-matched Cox-proportional hazards models. Models were run separately in insurance groups and adjusted for cardiovascular and renal risk factors, markers of healthcare utilization, and other medication use.

RESULTS

We identified 3,905,155 statin initiators and 2,817,621 eligible non-users. The adjusted HR of AKI in statin initiators compared to non-users was: commercial, HR = 1.04 (95% CI: 0.99, 1.09); Medicare, HR = 0.72 (95% CI: 0.70, 0.75). PS-matching yielded: commercial, HR = 0.82 (95% CI: 0.78, 0.87); Medicare, HR = 0.66 (95% CI: 0.63, 0.69). As individual formulations, higher-potency simvastatin was associated with an increased risk of AKI over lower-potency simvastatin in adjusted models: commercial, HR = 1.42 (95% CI: 1.28, 1.58); Medicare, HR = 1.24 (95% CI: 1.15, 1.35).

CONCLUSIONS

As a class, statin initiation was not associated with an increase in AKI. However, higher-potency simvastatin did exhibit an increased AKI risk.

Short-term rosuvastatin therapy for prevention of contrast-induced acute kidney injury in patients with diabetes and chronic kidney disease

OBJECTIVES

This study sought to evaluate the safety and efficacy of rosuvastatin in preventing contrast-induced acute kidney injury (CI-AKI) in patients with diabetes mellitus (DM) and chronic kidney disease (CKD).

BACKGROUND

CI-AKI is an important complication after contrast medium injection. While small studies have shown positive results with statin therapy, the role of statin therapy in prevention of CI-AKI remains unknown.

METHODS

We randomized 2,998 patients with type 2 DM and concomitant CKD who were undergoing coronary/peripheral arterial angiography with or without percutaneous intervention to receive rosuvastatin, 10 mg/day (n = 1,498), for 5 days (2 days before, and 3 days after procedure) or standard-of-care (n = 1,500). Patients' renal function was assessed at baseline, 48 h, and 72 h after exposure to contrast medium. The primary endpoint of the study was the development of CI-AKI, which was defined as an increase in serum creatinine concentration ≥0.5 mg/dl (44.2 μmol/l) or 0.25% above baseline at 72 h after exposure to contrast medium.

RESULTS

Patients randomized to the rosuvastatin group had a significantly lower incidence of CI-AKI than controls (2.3% vs. 3.9%, respectively; p = 0.01). During 30 days' follow-up, the rate of worsening heart failure was significantly lower in the patients treated with rosuvastatin than that in the control group (2.6% vs. 4.3%, respectively; p = 0.02).

CONCLUSIONS

Rosuvastatin significantly reduced the risk of CI-AKI in patients with DM and CKD undergoing arterial contrast medium injection. (Rosuvastatin Prevent Contrast Induced Acute Kidney Injury in Patients With Diabetes [TRACK-D]; NCT00786136).

Effect of statin use on acute kidney injury risk following coronary artery bypass grafting

Acute kidney injury (AKI) is a serious complication of cardiovascular surgery. Although some nonexperimental studies suggest that statin use may reduce postsurgical AKI, methodologic differences in study designs leave uncertainty regarding the reality or magnitude of the effect. The aim of this study was to estimate the effect of preoperative statin initiation on AKI after coronary artery bypass grafting (CABG) using an epidemiologic approach more closely simulating a randomized controlled trial in a large CABG patient population. Health care claims from large, employer-based and Medicare insurance databases for 2000 to 2010 were used. To minimize healthy user bias, patients were identified who underwent nonemergent CABG who either newly initiated a statin <20 days before surgery or were unexposed for ≥200 days before CABG. AKI was identified <15 days after CABG. Multivariate-adjusted risk ratios (RRs) and 95% confidence intervals (CIs) were calculated using Poisson regression. Analyses were repeated using propensity score methods adjusted for clinical and health care utilization variables. A total of 17,077 CABG patients were identified. Post-CABG AKI developed in 3.4% of statin initiators and 6.2% of noninitiators. After adjustment, a protective effect of statin initiation on AKI was observed (RR 0.78, 95% CI 0.63 to 0.96). This effect differed by age, with an RR of 0.91 (95% CI 0.68 to 1.20) for patients aged ≥65 years and an RR of 0.62 (95% CI 0.45 to 0.86) for those aged <65 years, although AKI was more common in the older group (7.7% vs 4.0%). In conclusion, statin initiation immediately before CABG may modestly reduce the risk for postoperative AKI, particularly in younger CABG patients.

"Sit back, observe, and wait." Or is there a pharmacologic preventive treatment for cerebral aneurysms?

Intracranial aneurysms (IA) are a relatively frequent vascular abnormality. The prevailing opinion is that cerebral aneurysmal disease is related to hemodynamic and genetic factors, associated with structural weakness in the arterial wall which was acquired by a specific, often unknown, event. Possibly the trigger moment of aneurysm formation may depend on the dynamic arterial growth, which is closely related to aging/atherosclerosis. In most individuals, an endovascular/microsurgical approach is possible in order to obliterate the IA. However, in a number of patients with an unruptured IA (UIA), the neurosurgeon's decision is to just "sit back, observe, and wait", based on the favorable natural history of some of the UIAs. Furthermore, some individuals need to be kept under close observation since they have a higher chance of developing IA, especially those with at least two affected first-degree relatives with an IA, subjects with polycystic kidney disease, and patients who have undergone an aneurysm intervention. In these examples prophylactic strategies should be adopted, if it is at all possible. The main question is deciding the best option of clinical treatment for these cases, when surgical approach is contraindicated, or for those subjects who are more prone to develop an IA. In the present article, we hypothetically suggest a pharmacologic form of treatment with statins, beta-adrenergic blocker agents, and/or angiotensin-converting-enzyme inhibitor/angiotensin II receptor blockers to inhibit or slow down IA formation, taking into consideration some pathophysiological aspects related to aneurysmal development, such as: hemodynamic stress, arterial wall inflammation, nitric oxide formation, and atheromatous disease.

HMG-CoA Reductase Inhibitors for Prevention and Treatment of Severe Sepsis

HMG-CoA reductase inhibitors, or statins, are among the most commonly prescribed pharmaceuticals in the world, especially among the elderly. The remarkable conjuncture of this fact with the rising incidence of severe sepsis among people over age 65 could prove to be of serendipitous benefit, because numerous actions of the statins make them of potential use in the prevention and treatment of severe sepsis. Severe sepsis continues to be a highly lethal condition, for which there are, as yet, no effective pharmacological treatments, save antibiotics. We explore the biological plausibility of statins as prophylaxis agents and as treatment for severe sepsis and thoroughly review the preclinical and clinical studies that have explored the effects of statins in infected and septic patients. Statins remain only promising treatments for severe sepsis, without convincing evidence that they reduce patient mortality. Ongoing randomized trials may provide conclusive evidence, whether positive or negative.

Streptococcal m1 protein triggers farnesyltransferase-dependent formation of CXC chemokines in alveolar macrophages and neutrophil infiltration of the lungs

The M1 serotype of Streptococcus pyogenes plays an important role in streptococcal toxic shock syndrome. Simvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, has been shown to inhibit streptococcal M1 protein-induced acute lung damage, although downstream mechanisms remain elusive. Protein isoprenylation, such as farnesylation and geranylgeranylation, has been suggested to regulate anti-inflammatory effects exerted by statins. Here, we examined the effect of a farnesyltransferase inhibitor (FTI-277) on M1 protein-triggered lung inflammation. Male C57BL/6 mice were treated with FTI-277 prior to M1 protein challenge. Bronchoalveolar fluid and lung tissue were harvested for quantification of neutrophil recruitment, edema, and CXC chemokine formation. Flow cytometry was used to determine Mac-1 expression on neutrophils. The gene expression of CXC chemokines was determined in alveolar macrophages by using quantitative reverse transcription (RT)-PCR. We found that the administration of FTI-277 markedly decreased M1 protein-induced accumulation of neutrophils, edema formation, and tissue damage in the lung. Notably, inhibition of farnesyltransferase abolished M1 protein-evoked production of CXC chemokines in the lung and gene expression of CXC chemokines in alveolar macrophages. Moreover, FTI-277 completely inhibited chemokine-induced neutrophil migration in vitro. However, farnesyltransferase inhibition had no effect on M1 protein-induced expression of Mac-1 on neutrophils. Our findings suggest that farnesyltransferase is a potent regulator of CXC chemokine formation in alveolar macrophages and that inhibition of farnesyltransferase not only reduces neutrophil recruitment but also attenuates acute lung injury provoked by streptococcal M1 protein. We conclude that farnesyltransferase activity is a potential target in order to attenuate acute lung damage in streptococcal infections.

Statins in the critically ill

The use or misuse of statins in critically ill patients recently attracted the attention of intensive care clinicians. Indeed, statins are probably the most common chronic treatment before critical illness and some recent experimental and clinical data demonstrated their beneficial effects during sepsis, acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), or after aneurismal subarachnoidal hemorrhage (aSAH). Due to the heterogeneity of current studies and the lack of well-designed prospective studies, definitive conclusions for systematic and large-scale utilization in intensive care units cannot be drawn from the published evidence. Furthermore, the extent of statins side effects in critically ill patients is still unknown. For the intensive care clinician, it is a matter of individually identifying the patient who can benefit from this therapy according to the current literature. The purpose of this review is to describe the mechanisms of actions of statins and to synthesize the clinical data that underline the relevant effects of statins in the particular setting of critical care, in an attempt to guide the clinician through his daily practice.

Statins and outcomes in patients with bloodstream infection: a propensity-matched analysis

OBJECTIVE

The pleiotropic effects of statins, 3-hydroxy-3 methylglutaryl coenzyme A reductase inhibitor, have been shown to modify inflammatory cell signaling on the immune response to infection. It was postulated that statins may be a good candidate as novel therapeutic agents for the treatment of sepsis. We investigated whether ongoing statin therapy is associated with mortality in patients with bloodstream infection.

DESIGN

A retrospective cohort study.

SETTING

Two tertiary hospitals in Bronx, NY.

PATIENTS

Adult patients in the hospital with bloodstream infection and categorized according to statin therapy as an outpatient or inpatient before bacteremia.

INTERVENTIONS

None.

MEASUREMENT AND MAIN RESULTS

Of 2,139 bacteremic hospitalized patients, 592 (28%) received statins before blood cultures and 677 (32%) died within 90 days. On multivariate adjustment, the association between statin therapy and 90-day all-cause mortality was statistically significant (hazard ratio, 0.78; 95% confidence interval [CI] 0.65-0.94), but statin users and nonusers differed significantly on many baseline clinical factors. Using the propensity score matched analysis to balance the differences between groups, the association was no longer significant (hazard ratio 0.99; 95% CI 0.77-1.25). Multivariate analysis after stratifying by decile in propensity score for statin use demonstrated similar results (hazard ratio 0.86; 95% CI 0.70-1.06). Statin use was not associated with reduced intensive care unit admission (odds ratio [OR], 0.86; 95% CI 0.59-1.26), hospital length of stay (β = -0.8 days; 95% CI -2.2 to 1.7 days), intensive care unit length of stay (β = -0.1 days; 95% CI -3.7 to 3.8 days), or need for mechanical or noninvasive ventilation (OR 1.03; 95% CI 0.70-1.51).

CONCLUSION

After adjusting for the propensity to receive statin therapy, no statistically significant association between statin therapy before bloodstream infection and survival was identified.

Anti-inflammatory effect of simvastatin in an experimental model of spinal cord trauma: involvement of PPAR-α

BACKGROUND

Statins such as simvastatin are inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase used in the prevention of cardiovascular disease. In addition to their cholesterol-lowering activities, statins exert pleiotropic anti-inflammatory effects, which might contribute to their beneficial effects on lipid-unrelated inflammatory diseases. Recently it has been demonstrated that the peroxisome proliferator-activated receptor (PPAR)-α mediates anti-inflammatory effects of simvastatin in vivo models of acute inflammation. Moreover, previous results suggest that PPAR-α plays a role in control of secondary inflammatory process associated with spinal cord injury (SCI).

METHODS

With the aim to characterize the role of PPAR-α in simvastatin activity, we tested the efficacy of simvastatin (10 mg/kg dissolved in saline i.p. 1 h and 6 h after the trauma) in an experimental model of SCI induced in mice by extradural compression of the spinal cord (T6-T7 level) using an aneurysm clip with a closing force of 24 g via a four-level T5-T8 laminectomy, and comparing mice lacking PPAR-α (PPAR-α KO) with wild type (WT) mice. In order to elucidate whether the effects of simvastatin are due to activation of the PPAR-α, we also investigated the effect of a PPAR-α antagonist, GW6471 (1 mg/kg administered i.p. 30 min prior treatment with simvastatin) on the protective effects of on simvastatin.

RESULTS

Results indicate that simvastatin activity is weakened in PPAR-α KO mice, as compared to WT controls. In particular, simvastatin was less effective in PPAR-α KO, compared to WT mice, as evaluated by inhibition of the degree of spinal cord inflammation, neutrophil infiltration, nitrotyrosine formation, pro-inflammmatory cytokine expression, nuclear factor (NF)-κB activation, inducible nitric-oxide synthase (iNOS) expression, and apoptosis. In addition we demonstrated that GW6471 significantly antagonized the effect of the statin and thus abolished the protective effect.

CONCLUSIONS

This study indicates that PPAR-α can contribute to the anti-inflammatory activity of simvastatin in SCI.

Atorvastatin treatment is effective when used in combination with mefloquine in an experimental cerebral malaria murine model

BACKGROUND

One of the major complications of Plasmodium falciparum infection is cerebral malaria (CM), which causes one million deaths worldwide each year, results in long-term neurological sequelae and the treatment for which is only partially effective. Statins are recognized to have an immunomodulatory action, attenuate sepsis and have a neuroprotective effect. Atorvastatin (AVA) has shown in vitro anti-malarial activity and has improved the activity of mefloquine (MQ) and quinine.

METHODS

The efficiency of 40 mg/kg intraperitoneal AVA, alone or in association with MQ, was assessed in an experimental Plasmodium berghei ANKA rodent parasite model of CM and performed according to different therapeutic schemes. The effects on experimental CM were assessed through the evaluation of brain histopathological changes and neuronal apoptosis by TUNEL staining.

RESULTS

AVA alone in the therapeutic scheme show no effect on survival, but the prophylactic scheme employing AVA associated with MQ, rather than MQ alone, led to a significant delay in mouse death and had an effect on the onset of CM symptoms and on the level of parasitaemia. Histopathological findings show a correlation between brain lesions and CM onset. A neuronal anti-apoptotic effect of AVA in the AVA + MQ combination was not shown.

CONCLUSIONS

The combination of AVA and MQ therapy led to a significant delay in mouse mortality. There were differences in the incidence, time to cerebral malaria and the level of parasitaemia when the drug combination was administered to mice. When used in combination with MQ, AVA had a relevant effect on the in vivo growth inhibition and clinical outcome of P. berghei ANKA-infected mice.

PPARα mediates the anti-inflammatory effect of simvastatin in an experimental model of zymosan-induced multiple organ failure

BACKGROUND AND PURPOSE

Zymosan-induced non-septic shock is a multi-factorial pathology that involves several organs including the kidneys, liver and lungs. Its complexity and diversity presents a continuing therapeutic challenge. Given their pleiotropic effect, statins could be beneficial in non-septic shock. One of the molecular mechanisms underlying the anti-inflammatory effect of statins involves the peroxisome proliferator-activated receptor (PPAR) α. We used a zymosan-induced non-septic shock experimental model to investigate the role of PPARα in the anti-inflammatory effects of simvastatin.

EXPERIMENTAL APPROACH

Effects of simvastatin (5 or 10 mg·kg(-1) i.p.) were analysed in PPARα knock-out (KO) and PPARα wild type (WT) mice after zymosan or vehicle administration. Organ injury in lung, liver, kidney and intestine was evaluated by immunohistology. PPARα mRNA expression and nuclear factor-κB activation were evaluated in all experimental groups, 18 h after study onset. Cytokine levels were measured in plasma, and nitrite/nitrate in plasma and peritoneal exudate. Nitric oxide synthase, nitrotyrosine and poly ADP-ribose were localized by immunohistochemical methods.

KEY RESULTS

Simvastatin significantly and dose-dependently increased the zymosan-induced expression of PPARα levels in all tissues analysed. It also dose-dependently reduced systemic inflammation and the organ injury induced by zymosan in lung, liver, intestine and kidney. These effects were observed in PPARαWT mice and in PPARαKO mice.

CONCLUSIONS AND IMPLICATIONS

Simvastatin protected against the molecular and cellular damage caused by systemic inflammation in our experimental model. Our results also provide new information regarding the role of PPARα in the anti-inflammatory effects of statins.

Statins in prevention and treatment of severe sepsis and septic shock

Severe sepsis is an infection-induced inflammatory syndrome that can lead to multi-organ dysfunction and continues to be a major cause of morbidity and mortality worldwide. Because numerous cascades are triggered during sepsis, selective blocking of inflammatory mediators may be insufficient to arrest this process, and recent therapeutic approaches have proven controversial. Statins are the most commonly prescribed agents for hypercholesterolaemia and dominate the area of cardiovascular risk reduction. Moreover, these drugs have a variety of actions that are independent of their lipid lowering effect. Such anti-inflammatory, antioxidant, immunomodulatory, and antiapoptotic features have been collectively referred to as pleiotropic effects. By virtue of their pleiotropic effects, statins have also emerged as potentially useful in various critical care areas such as bacteraemia, the early phases of sepsis and septic shock, as well as the management of serious infections. This review outlines current evidence on the use of statins for preventing and treating sepsis.

Simvastatin regulates CXC chemokine formation in streptococcal M1 protein-induced neutrophil infiltration in the lung

Streptococcus pyogenes of the M1 serotype can cause streptococcal toxic shock syndrome and acute lung injury. Statins exert beneficial effects in septic patients although the mechanisms remain elusive. This study examined effects of simvastatin on M1 protein-provoked pulmonary inflammation and tissue injury. Male C57BL/6 mice were pretreated with simvastatin or a CXCR2 antagonist before M1 protein challenge. Bronchoalveolar fluid and lung tissue were harvested for determination of neutrophil infiltration, formation of edema, and CXC chemokines. Flow cytometry was used to determine Mac-1 expression on neutrophils. Gene expression of CXC chemokines was determined in alveolar macrophages by using quantitative RT-PCR. M1 protein challenge caused massive infiltration of neutrophils, edema formation, and production of CXC chemokines in the lung as well as upregulation of Mac-1 on circulating neutrophils. Simvastatin reduced M1 protein-induced infiltration of neutrophils and edema in the lung. In addition, M1 protein-induced Mac-1 expression on neutrophils was abolished by simvastatin. Furthermore, simvastatin markedly decreased pulmonary formation of CXC chemokines and gene expression of CXC chemokines in alveolar macrophages. Moreover, the CXCR2 antagonist reduced M1 protein-induced neutrophil expression of Mac-1 and accumulation of neutrophils as well as edema formation in the lung. These novel findings indicate that simvastatin is a powerful inhibitor of neutrophil infiltration in acute lung damage triggered by streptococcal M1 protein. The inhibitory effect of simvastatin on M1 protein-induced neutrophil recruitment appears related to reduced pulmonary generation of CXC chemokines. Thus, simvastatin may be a useful tool to ameliorate acute lung injury in streptococcal infections.

Simvastatin antagonizes CD40L secretion, CXC chemokine formation, and pulmonary infiltration of neutrophils in abdominal sepsis

Statins have been reported to exert anti-inflammatory actions and protect against septic organ dysfunction. Herein, we hypothesized that simvastatin may attenuate neutrophil activation and lung damage in abdominal sepsis. Male C57BL/6 mice were pretreated with simvastatin (0.5 or 10 mg/kg) before CLP. In separate groups, mice received an anti-CD40L antibody or a CXCR2 antagonist (SB225002) prior to CLP. BALF and lung tissue were harvested for analysis of neutrophil infiltration, as well as edema and CXC chemokine formation. Blood was collected for analysis of Mac-1 and CD40L expression on neutrophils and platelets, as well as soluble CD40L in plasma. Simvastatin decreased CLP-induced neutrophil infiltration and edema formation in the lung. Moreover, Mac-1 expression increased on septic neutrophils, which was significantly attenuated by simvastatin. Inhibition of CD40L reduced CLP-induced up-regulation of Mac-1 on neutrophils. Simvastatin prevented CD40L shedding from the surface of platelets and reduced circulating levels of CD40L in septic mice. CXC chemokine-induced migration of neutrophils in vitro was decreased greatly by simvastatin. Moreover, simvastatin abolished CLP-evoked formation of CXC chemokines in the lung, and a CXCR2 antagonist attenuated pulmonary accumulation of neutrophils. Our data suggest that the inhibitory effect of simvastatin on pulmonary accumulation of neutrophils may be related to a reduction of CD40L secretion into the circulation, as well as a decrease in CXC chemokine formation in the lung. Thus, these protective mechanisms help to explain the beneficial actions exerted by statins, such as simvastatin, in sepsis.