Prophylactic Treatment With Simvastatin Modulates the Immune Response and Increases Animal Survival Following Lethal Sepsis Infection

Prophylactic use of standardized extract of propolis of Apis mellifera (EPP-AF®) reduces lung inflammation and improves survival in experimental lethal sepsis

ETHNOPHARMACOLOGICAL RELEVANCE

Sepsis poses one of the biggest public health problems, necessitating the search for new therapeutic alternatives. For centuries, propolis has been widely used in folk medicine to treat various inflammatory and infectious diseases. Given its extensive use, it has excellent potential as an adjuvant treatment for patients with sepsis.

OBJECTIVE

This study evaluated prophylactic treatment with standardized propolis extract (EPP-AF®) and followed the prognosis of sepsis induced by ligation and cecal ligation and puncture (CLP).

METHODS

Initially, for survival assessment, Swiss mice were separated into five groups: Sham (false operated), control (PBS), ATB (received antibiotic, 8 mg/kg), P10 (received EPP-AF®, 10 mg/kg), and P100 (received EPP-AF®, 100 mg/kg). The animals received PBS, antibiotic, or EPP-AF® by the subcutaneous route 6 h before the CLP procedure. Animal survival was assessed every 12 h for five days when all of them were euthanized.

RESULTS

We show that the treatment with EPP-AF® significantly increased the life expectancy of animals with sepsis compared to the control group. Interestingly, prophylactic treatment with EPP-AF® showed no effect on the number of colony-forming units in the peritoneum, blood, or lung. However, there was a decrease in cellular influx in the peritoneum. This alteration was unrelated to the number of bone marrow cells or the differential counting of peripheral blood cells. The coagulogram remained unchanged, including the number of platelets and prothrombin time-activated partial thromboplastin time. However, the inflammatory infiltrate and bleeding in the lung tissue were lower in the animals that received EPP-AF®.

CONCLUSION

Thus, it was possible to conclude that prophylactic treatment with EPP-AF® preserved the lung parenchyma, resulting in an increased lifespan of mice with sepsis. It can be a helpful adjuvant in prophylactic treatment with antibiotics in presurgical conditions.

Previous use of statins does not improve the outcome of bloodstream infection after kidney transplantation

Previous studies have suggested that exposure to statins confers a protective effect in bloodstream infection (BSI) due to the anti-inflammatory and immunomodulatory properties attributed to these lipid-lowering drugs. Scarce evidence is available for the solid organ transplant population. Therefore, we compared the time to clinical cure (primary outcome) and the time to fever resolution, new requirement of intensive care unit admission or renal replacement therapy, and 30-day all-cause mortality (secondary outcomes) between kidney transplant (KT) recipients with post-transplant BSI that were receiving or not statin therapy for at least the previous 30 days. We included 80 KT recipients that developed 109 BSI episodes (43 [39.4%] and 66 [60.6%] episodes within the statin and non-statin groups, respectively). The median interval since the initial prescription to BSI was 512 days (interquartile range [IQR]: 172-1388). Most episodes were of urinary source and due to Enterobacterales. There were no differences in the median time to clinical cure in the statin and non-statin groups (3.4 [IQR: 3-6.8] versus 4 [IQR: 2-6] days; p-value = .112). The lack of effect was confirmed by multiple linear regression analysis adjusted for confounding factors (standardized β coefficient = 0.040; p-value = .709). No significant differences were observed for any of the secondary outcomes either. Vital signs and laboratory values at BSI onset and after 72-96 h were similar in both groups. In conclusion, previous statin therapy had no apparent protective effect on the outcome of post-transplant BSI among KT recipients.

Prophylactic simvastatin increased survival during endotoxemia and inhibited granulocyte trafficking in a cell-intrinsic manner

Cross sectional studies have shown that statin-users have improved odds of surviving severe sepsis. Meanwhile controlled clinical trials failed to demonstrate improved sepsis survival with acute statin administration following hospitalization. Here, a lethal murine peritoneal lipopolysaccharide (LPS) endotoxemia model was used to assess the efficacy of chronic versus acute simvastatin on survival. Mirroring clinical observations, chronic but not acute treatment with simvastatin significantly increased survival. At a pre-mortality time point in LPS-treated mice, chronic simvastatin suppressed granulocyte trafficking in to the lungs and peritoneum without otherwise suppressing emergency myelopoiesis, myeloid cells in circulation, or inflammatory cytokines. Chronic simvastatin treatment significantly downregulated inflammatory chemokine gene signature in the lungs of LPS-treated mice. Thus, it was unclear if simvastatin was inhibiting granulocyte chemotaxis in a cell intrinsic or extrinsic manner. Adoptive transfer of fluorescently labeled granulocytes from statin and vehicle treated mice into LPS-treated mice showed that simvastatin inhibited lung-granulocyte trafficking in a cell intrinsic manner. Congruent with this, chemotaxis experiments using in vitro macrophages and ex vivo granulocytes demonstrated that simvastatin inhibited chemotaxis in a cell-intrinsic manner. Collectively, chronic but not acute simvastatin treatment improved survival in murine endotoxemia, and this was associated with cell-intrinsic inhibition of granulocyte chemotaxis.

ADAM10-a "multitasker" in sepsis: focus on its posttranslational target

BACKGROUND

Sepsis has a complex pathogenesis in which the uncontrolled systemic inflammatory response triggered by infection leads to vascular barrier disruption, microcirculation dysfunction and multiple organ dysfunction syndrome. Numerous recent studies reveal that a disintegrin and metalloproteinase 10 (ADAM10) acts as a "molecular scissor" playing a pivotal role in the inflammatory response during sepsis by regulating proteolysis by cleaving various membrane protein substrates, including proinflammatory cytokines, cadherins and Notch, which are involved in intercellular communication. ADAM10 can also act as the cellular receptor for Staphylococcus aureus α-toxin, leading to lethal sepsis. However, its substrate-specific modulation and precise targets in sepsis have not yet to be elucidated.

METHODS

We performed a computer-based online search using PubMed and Google Scholar for published articles concerning ADAM10 and sepsis.

CONCLUSIONS

In this review, we focus on the functions of ADAM10 in sepsis-related complex endothelium-immune cell interactions and microcirculation dysfunction through the diversity of its substrates and its enzymatic activity. In addition, we highlight the posttranslational mechanisms of ADAM10 at specific subcellular sites, or in multimolecular complexes, which will provide the insight to intervene in the pathophysiological process of sepsis caused by ADAM10 dysregulation.

Cholesterol accumulation on dendritic cells reverses chronic hepatitis B virus infection-induced dysfunction

Chronic hepatitis B (CHB) infection remains a serious public health problem worldwide; however, the relationship between cholesterol levels and CHB remains unclear. We isolated peripheral blood mononuclear cells from healthy blood donors and CHB patients to analyze free cholesterol levels, lipid raft formation, and cholesterol metabolism-related pathways. Hepatitis B virus (HBV)-carrier mice were generated and used to confirm changes in cholesterol metabolism and cell-surface lipid raft formation in dendritic cells (DCs) in the context of CHB. Additionally, HBV-carrier mice were immunized with a recombinant HBV vaccine (rHBVvac) combined with lipophilic statins and evaluated for vaccine efficacy against HBV. Serum samples were analyzed for HBsAg, anti-HBs, and alanine aminotransferase levels, and liver samples were evaluated for HBV DNA and RNA and HBcAg. CHB reduced free cholesterol levels and suppressed lipid raft formation on DCs in patients with CHB and HBV-carrier mice, whereas administration of lipophilic statins promoted free cholesterol accumulation and restored lipid rafts on DCs accompanied by an enhanced antigen-presentation ability in vitro and in vivo. Cholesterol accumulation on DCs improved the rHBVvac-mediated elimination of serum HBV DNA and intrahepatic HBV DNA, HBV RNA, and HBcAg and promoted the rHBVvac-mediated generation and polyfunctionality of HBV-specific CD11ahi CD8αlo cells, induction of the development of memory responses against HBV reinfection, and seroconversion from HBsAg to anti-HBs. The results demonstrated the important role of cholesterol levels in DC dysfunction during CHB, suggesting that strategies to increase cholesterol accumulation on DCs might enhance therapeutic vaccine efficacy against HBV and support development toward clinical CHB treatment.

Anthrax Meningoencephalitis and Intracranial Hemorrhage

The neurological sequelae of Bacillus anthracis infection include a rapidly progressive fulminant meningoencephalitis frequently associated with intracranial hemorrhage, including subarachnoid and intracerebral hemorrhage. Higher mortality than other forms of bacterial meningitis suggests that antimicrobials and cardiopulmonary support alone may be insufficient and that strategies targeting the hemorrhage might improve outcomes. In this review, we describe the toxic role of intracranial hemorrhage in anthrax meningoencephalitis. We first examine the high incidence of intracranial hemorrhage in patients with anthrax meningoencephalitis. We then review common diseases that present with intracranial hemorrhage, including aneurysmal subarachnoid hemorrhage and spontaneous intracerebral hemorrhage, postulating applicability of established and potential neurointensive treatments to the multimodal management of hemorrhagic anthrax meningoencephalitis. Finally, we examine the therapeutic potential of minocycline, an antimicrobial that is effective against B. anthracis and that has been shown in preclinical studies to have neuroprotective properties, which thus might be repurposed for this historically fatal disease.

Topical Simvastatin Improves Lesions of Diffuse Normolipemic Plane Xanthoma by Inhibiting Foam Cell Pyroptosis

Xanthoma pathogenesis is speculated to be associated with oxidized low-density lipoprotein (ox-LDL) deposition, although this remains unclear. Most patients with diffuse plane xanthomas present elevated blood lipid levels, and they benefit from treatment with oral lipid-lowering agents. However, there is no available treatment for diffuse normolipemic plane xanthoma (DNPX). In this study, for the first time, we used a topical simvastatin ointment to treat DNPX in three pediatric patients and observed favorable results. Immunofluorescence staining showed that the pyroptotic pathway was significantly attenuated after topical simvastatin application on the skin lesions of the patients. As ox-LDL deposition was observed in the lesions, we used ox-LDL to build a foam cell model in vitro. In the ox-LDL-induced foam cell formation, simvastatin consistently inhibited pyroptotic activation and inflammation in the macrophages. Additionally, the overexpression of nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) or 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase (HMGCR), the known target of statins, reversed the effects of simvastatin. Moreover, gasdermin D (GSDMD) or HMGCR knockdown inhibited ox-LDL-induced pyroptosis. Furthermore, the immunoprecipitation results confirmed the interaction between NLRP3 and HMGCR, and this interaction was inhibited by simvastatin. In conclusion, we demonstrated that topical application of simvastatin ointment might be a promising treatment for DNPX skin lesions and that this therapeutic effect may be related to pyroptosis inhibition via HMGCR inhibition in foam cells. Moreover, xanthoma pathogenesis might be associated with ox-LDL deposition and inflammation.

Cinnamaldehyde Increases the Survival of Mice Submitted to Sepsis Induced by Extraintestinal Pathogenic Escherichia coli

Several natural products have been investigated for their bactericidal potential, among these, cinnamaldehyde. In this study, we aimed to evaluate the activity of cinnamaldehyde in the treatment of animals with sepsis induced by extraintestinal pathogenic E. coli. Initially, the E. coli F5 was incubated with cinnamaldehyde to evaluate the minimum inhibitory and minimum bactericidal concentration. Animal survival was monitored for five days, and a subset of mice were euthanized after 10 h to evaluate histological, hematological, and immunological parameters, as well as the presence of bacteria in the organs. On the one hand, inoculation of bacterium caused the death of 100% of the animals within 24 h after infection. On the other hand, cinnamaldehyde (60 mg/kg) was able to keep 40% of mice alive after infection. The treatment significantly reduced the levels of cytokines in serum and peritoneum and increased the production of cells in both bone marrow and spleen, as well as lymphocytes at the infection site. Cinnamaldehyde was able to reduce tissue damage by decreasing the deleterious effects for the organism and contributed to the control of the sepsis and survival of animals; therefore, it is a promising candidate for the development of new drugs.

Gasdermin D inhibition prevents multiple organ dysfunction during sepsis by blocking NET formation

Multiple organ dysfunction is the most severe outcome of sepsis progression and is highly correlated with a worse prognosis. Excessive neutrophil extracellular traps (NETs) are critical players in the development of organ failure during sepsis. Therefore, interventions targeting NET release would likely effectively prevent NET-based organ injury associated with this disease. Herein, we demonstrate that the pore-forming protein gasdermin D (GSDMD) is active in neutrophils from septic humans and mice and plays a crucial role in NET release. Inhibition of GSDMD with disulfiram or genic deletion abrogated NET formation, reducing multiple organ dysfunction and sepsis lethality. Mechanistically, we demonstrate that during sepsis, activation of the caspase-11/GSDMD pathway controls NET release by neutrophils during sepsis. In summary, our findings uncover a novel therapeutic use for disulfiram and suggest that GSDMD is a therapeutic target to improve sepsis treatment.

Simvastatin inhibits the inflammation and oxidative stress of human neutrophils in sepsis via autophagy induction

Simvastatin exerts a protective effect during sepsis (SP) in animal models; however, the underlying mechanism is not completely understood, particularly in human SP. Neutrophils are a critical effector in the host inflammatory response to SP. Therefore, the present study aimed to investigate the effect of simvastatin on neutrophils in human SP. Neutrophils were isolated from the peripheral venous blood of adult patients with SP and healthy volunteers (HP). Cell viability was analyzed using the MTT assay. Intracellular reactive oxygen species (ROS) generation and the concentrations of inflammatory mediators were also assessed using flow cytometry and ELISA. The results demonstrated that the cell viability of neutrophils from the SP group was significantly decreased compared with that in the HP group, and that treatment with simvastatin partly reversed the reduced cell viability. Furthermore, simvastatin administration significantly decreased ROS production and the concentrations of TNF‑α and IL‑6, which were significantly increased in neutrophils isolated from the SP group. Simvastatin also enhanced autophagy induction, as indicated by the promotion of the conversion of LC3I to LC3II and the increased expression levels of Beclin 1 in SP neutrophils. Treatment with 3‑methyladenine, an autophagy inhibitor, completely blocked the protective effects of simvastatin on neutrophils from SP, including the effects of simvastatin on the inhibition of inflammation, oxidative stress and improving cell viability. Collectively, the present study provided evidence for the simvastatin‑induced autophagic process of neutrophils involved in human SP, which protects neutrophils and partially attenuates the inflammatory response and oxidative stress. Therefore, the augmentation of neutrophil autophagy may serve as a potential therapeutic target for patients with SP.

Prophylactic simvastatin treatment modulates the immune response and increases survival of mice following induction of lethal sepsis

Objective

To investigate whether and how simvastatin mediates protection from lethal sepsis, using a mouse model.

Methods

Sixty C57BL/6 mice were selected and divided into three groups (“control,” “model,” and “observation”; n = 20 mice per group). Mice in the model and observation groups underwent cecal ligation and puncture; mice in the observation group received simvastatin. After 24 hours of induced sepsis, serum concentrations of IL-6, TNF-α, IL-1, and IL-10 were measured by ELISA. Serum malondialdehyde (MDA) concentrations and serum superoxide dismutase (SOD) activities were quantified by radioimmunoassay.

Results

The mean duration of survival of mice in the observation group was significantly longer than that of the model group. The serum concentrations of IL-6, TNF-α, IL-1, IL-10, and MDA were significantly higher in the observation group than in the control group. Serum SOD activities were significantly lower in the observation group than in the control group.

Conclusions

Simvastatin can alleviate symptoms of sepsis in mice and improve their rates of survival. The mechanism of action of simvastatin may be mediated by inhibition of the systemic inflammatory response and oxidative stress.

Biotechnological Production of Statins: Metabolic Aspects and Genetic Approaches

Statins are drugs used for people with abnormal lipid levels (hyperlipidemia) and are among the best-selling medications in the United States. Thus, the aspects related to the production of these drugs are of extreme importance for the pharmaceutical industry. Herein, we provide a non-exhaustive review of fungal species used to produce statin and highlighted the major factors affecting the efficacy of this process. The current biotechnological approaches and the advances of a metabolic engineer to improve statins production are also emphasized. The biotechnological production of the main statins (lovastatin, pravastatin and simvastatin) uses different species of filamentous fungi, for example Aspergillus terreus. The statins production is influenced by different types of nutrients available in the medium such as the carbon and nitrogen sources, and several researches have focused their efforts to find the optimal cultivation conditions. Enzymes belonging to Lov class, play essential roles in statin production and have been targeted to genetic manipulations in order to improve the efficiency for Lovastatin and Simvastatin production. For instance, Escherichia coli strains expressing the LovD have been successfully used for lovastatin production. Other examples include the use of iRNA targeting LovF of A. terreus. Therefore, fungi are important allies in the fight against hyperlipidemias. Although many studies have been conducted, investigations on bioprocess optimization (using both native or genetic- modified strains) still necessary.

Statins improve the long-term prognosis in patients who have survived sepsis: A nationwide cohort study in Taiwan (STROBE complaint)

Most patients diagnosed with sepsis died during their first episode, with the long-term survival rate upon post-sepsis discharge being low. Major adverse cardiovascular events and recurrent infections were regarded as the major causes of death. No definite medications had proven to be effective in improving the long-term prognosis. We aimed to examine the benefits of statins on the long-term prognosis of patients who had survived sepsis.Between 1999 and 2013, a total of 220,082 patients who had been hospitalized due to the first episode of sepsis were included, with 134,448 (61.09%) of them surviving to discharge. The surviving patients who were subsequently prescribed statins at a concentration of more than 30 cumulative Defined Daily Doses (cDDDs) during post-sepsis discharge were defined as the users of statin.After a propensity score matching ratio of 1:5, a total of 7356 and 36,780 surviving patients were retrieved for the study (statin users) and comparison cohort (nonstatin users), respectively. The main outcome was to determine the long-term survival rate during post-sepsis discharge.HR with 95% CI was calculated using the Cox regression model to evaluate the effectiveness of statins, with further stratification analyses according to cDDDs.The users of statins had an adjusted HR of 0.29 (95% CI, 0.27-0.31) in their long-term mortality rate when compared with the comparison cohort. For the users of statins with cDDDs of 30-180, 180-365, and >365, the adjusted HRs were 0.32, 0.22, and 0.16, respectively, (95% CI, 0.30-0.34, 0.19-0.26, and 0.12-0.23, respectively), as compared with the nonstatins users (defined as the use of statins <30 cDDDs during post-sepsis discharge), with the P for trend <.0001. In the sensitivity analysis, after excluding the surviving patients who had died between 3 and 6 months after post-sepsis discharge, the adjusted HR for the users of statins remained significant (0.35, 95% CI 0.32-0.37 and 0.42, 95% CI 0.39-0.45, respectively).Statins may have the potential to decrease the long-term mortality of patients who have survived sepsis. However, more evidence, including clinical and laboratory data, is necessary in order to confirm the results of this observational cohort study.Trial registration: CMUH104-REC2-115.