Novel therapeutic targets for sepsis: regulation of exaggerated inflammatory responses

Scorch processing of rhubarb (Rheum tanguticum Maxim. ex Balf.) pyrolyzed anthraquinone glucosides into aglycones and improved the therapeutic effects on thromboinflammation via regulating the complement and coagulation cascades pathway

ETHNOPHARMACOLOGICAL RELEVANCE

The pathophysiological mechanism of thromboinflammation involves the intricate interplay between the inflammatory responses and coagulation cascades. Rhubarb is frequently used in traditional Chinese medicine to treat thromboinflammatory diseases. The scorched rhubarb (prepared by stir-baking the dried raw rhubarb till it partly turns to charcoal) is believed to possess enhanced blood-cooling and stasis-removing functions compared to the raw rhubarb, thereby augmenting the therapeutic effects on thromboinflammation.

AIM OF THE STUDY

This study aimed to explore the chemical and pharmacological foundations of the scorch processing of rhubarb in order to ensure and enhance the efficacy and safety of the scorched rhubarb for treating thromboinflammatory diseases.

MATERIALS AND METHODS

The dried raw rhubarb pieces were subjected to stir-baking at 180 °C for 10∼80 min to obtain the rhubarbs with varying degrees of scorching. Typical ingredients present in rhubarb pieces and extracts were determined by high-performance liquid chromatography. The therapeutic effects of the raw and scorched rhubarb on thromboinflammation were evaluated using a rat model. Proteomics analysis was employed to screen potential biological pathways associated with thromboinflammation treatment by the raw and scorched rhubarb, which were further verified using a cell model.

RESULTS

Morphological properties indicated that the rhubarb baked at 180 °C for 50 min in this research showed the optimal degree of scorching. Compared to the raw rhubarb, the properly scorched rhubarb exhibited lower levels of anthraquinone glucosides, higher levels of anthraquinone aglycones, superior anti-thromboinflammatory effects, and no purgative side effects. Proteomics analysis revealed that the complement and coagulation cascades pathway played a significant role in mediating the therapeutic effects of the raw and scorched rhubarb on thromboinflammation. Furthermore, it was found that anthraquinone aglycones were more effective than their glucoside counterparts in restoring the impaired vascular endothelial cells as well as regulating the complement and coagulation cascades pathway.

CONCLUSIONS

Proper scorch processing may augment the therapeutic effects of rhubarb on thromboinflammation via relieving inflammation and oxidative stress, repairing vascular endothelial cells, restoring coagulation cascades and blood rheology, and regulating some other biological processes. This may be partly caused by the scorch-induced thermolysis of anthraquinone glucosides into their aglycone counterparts that seemed to perform better in regulating the complement and coagulation cascades pathway.

Bioactive compounds and benefits of by-products of Amazon babassu oil production: potential for dietary supplement, biomedical and food applications

Babassu coconut (Attalea speciosa syn. Orbignya phalerata) contains an oil-rich nut and is primarily found in South America's Amazon region. Future market researchers predict an increase in the babassu oil market from USD 227.7 million in 2022 to USD 347.0 million by 2032, and the yield of babassu oil from babassu-processed waste could reach 90%. Of these, mesocarp flour is an underrated by-product used only for animal feed purposes by local producers. This comprehensive review focuses on advances in knowledge and understanding of phytochemicals from babassu oil by-products considering the mechanisms of action - covering antioxidant, antimicrobial, antiparasitic, anti-inflammatory, antithrombotic, immunomodulatory, and anticancer effects. Babassu coconut fruit contains free fatty acids, (poly)phenols, phytosterols, and triterpenes. Pytochemicals, antiparasitic and antibacterial activities of babassu mesocarp flour were shown, but fungi and viruses can get more attention. Beyond its antioxidant capacity, babassu mesocarp flour showed potential as a dietary food supplement. Aqueous suspensions of mesocarp flour with a higher preference for cancer cells than normal cells and an antithrombotic effect were also identified, probably related to the antioxidant capacity of its secondary metabolites. Mesocarp flour, a starch-rich fraction, is promising for application as biodegradable packaging to improve the oxidative stability of foods. Finally, low-added value fractions can be considered bio-waste/co-products, and their phytochemicals may attract interest for applications in medicine and nutrition. Toxicological concerns, trends, and gaps are discussed for the future of foods and related sciences.

The pathogenesis and potential therapeutic targets in sepsis

Sepsis is defined as "a life-threatening organ dysfunction caused by dysregulated host systemic inflammatory and immune response to infection." At present, sepsis continues to pose a grave healthcare concern worldwide. Despite the use of supportive measures in treating traditional sepsis, such as intravenous fluids, vasoactive substances, and oxygen plus antibiotics to eradicate harmful pathogens, there is an ongoing increase in both the morbidity and mortality associated with sepsis during clinical interventions. Therefore, it is urgent to design specific pharmacologic agents for the treatment of sepsis and convert them into a novel targeted treatment strategy. Herein, we provide an overview of the molecular mechanisms that may be involved in sepsis, such as the inflammatory response, immune dysfunction, complement deactivation, mitochondrial damage, and endoplasmic reticulum stress. Additionally, we highlight important targets involved in sepsis-related regulatory mechanisms, including GSDMD, HMGB1, STING, and SQSTM1, among others. We summarize the latest advancements in potential therapeutic drugs that specifically target these signaling pathways and paramount targets, covering both preclinical studies and clinical trials. In addition, this review provides a detailed description of the crosstalk and function between signaling pathways and vital targets, which provides more opportunities for the clinical development of new treatments for sepsis.

Host and Pathogen-Directed Therapies against Microbial Infections Using Exosome- and Antimicrobial Peptide-derived Stem Cells with a Special look at Pulmonary Infections and Sepsis

Microbial diseases are a great threat to global health and cause considerable mortality and extensive economic losses each year. The medications for treating this group of diseases (antibiotics, antiviral, antifungal drugs, etc.) directly attack the pathogenic agents by recognizing the target molecules. However, it is necessary to note that excessive use of any of these drugs can lead to an increase in microbial resistance and infectious diseases. New therapeutic methods have been studied recently using emerging drugs such as mesenchymal stem cell-derived exosomes (MSC-Exos) and antimicrobial peptides (AMPs), which act based on two completely different strategies against pathogens including Host-Directed Therapy (HDT) and Pathogen-Directed Therapy (PDT), respectively. In the PDT approach, AMPs interact directly with pathogens to interrupt their intrusion, survival, and proliferation. These drugs interact directly with the cell membrane or intracellular components of pathogens and cause the death of pathogens or inhibit their replication. The mechanism of action of MSC-Exos in HDT is based on immunomodulation and regulation, promotion of tissue regeneration, and reduced host toxicity. This review studies the potential of mesenchymal stem cell-derived exosomes/ATPs therapeutic properties against microbial infectious diseases especially pulmonary infections and sepsis.

Surgical Site Infections in Gastroenterological Surgery

Surgical site infections (SSIs) remain one of the most common serious surgical complications and are the second most frequent healthcare-associated infection. Patients with SSIs have a significantly increased postoperative length of hospital stay, hospital expenses, and mortality risk compared with patients without SSIs. The prevention of SSI requires the integration of a range of perioperative measures, and approximately 50% of SSIs are preventable through the implementation of evidence-based preventative strategies. Several international guidelines for SSI prevention are currently available worldwide. However, there is an urgent need for SSI prevention guidelines specific to Japan because of the differences in the healthcare systems of Japan versus western countries. In 2018, the Japan Society for Surgical Infection published SSI prevention guidelines for gastroenterological surgery. Although evidence-based SSI prevention guidelines are now available, it is important to consider the appropriateness of these guidelines depending on the actual conditions in each facility. A systemic inflammatory host response is a hallmark of bacterial infection, including SSI. Therefore, blood inflammatory markers are potentially useful in SSI diagnosis, outcome prediction, and termination of therapeutic intervention. In this review, we describe the current guideline-based perioperative management strategies for SSI prevention, focusing on gastroenterological surgery and the supplemental utility of blood inflammatory markers.

Dexmedetomidine Might Exacerbate Acute Kidney Injury, While Midazolam Might Have a Postconditioning Effect: A Rat Model of Lipopolysaccharide-Induced Acute Kidney Injury

BACKGROUND

The preconditioning effects of dexmedetomidine and propofol on septic acute kidney injury (AKI) have been reported, but the postconditioning effects remain unknown. This study investigated the postconditioning effects of dexmedetomidine, midazolam, and propofol on septic AKI.

METHODS

Forty-eight male Wistar rats were intraperitoneally administered lipopolysaccharide (LPS; 8.3 mg kg-1) or normal saline. Twenty-four hours later, rats were allocated to specific anesthetic groups (n=6 each) and exposed for 6 h, as follows: C, control (no anesthetic); D, dexmedetomidine (5 μg kg-1 h-1); M, midazolam (0.6 mg kg-1 h-1); or P, propofol (10 mg kg-1 h-1). Serum creatinine (Cr) and cystatin C (CysC) were measured at the end of anesthesia. Western blot and immunofluorescent analyses of kidney samples were performed.

RESULTS

Among LPS-treated groups, D group showed worsened renal dysfunction (L-C vs L-D: Cr, P=0.002, effect size (η2) =0.83; CysC, P=0.004, η2=0.71), whereas M group showed improved renal function (L-C vs L-M: Cr, P=0.009, η2=0.55). In immunofluorescent analysis of renal tubules, D group showed increased expression of nuclear factor κB (NFκΒ) (L-C vs L-D: NFκΒ, P=0.002, η2=0.75; phospho-NFκΒ, P=0.018, η2=0.66) and inhibitor of κ light polypeptide gene enhancer in B-cell kinase β (IKKβ) (L-C vs L-D: IKKβ, P=0.002, η2=0.59; phospho-IKKα/β, P=0.004, η2=0.59), whereas M group showed decreased NFκB expression (L-C vs L-M: NFκB, P=0.003, η2=0.55; phospho-NFκB, P=0.013, η2=0.46).

CONCLUSIONS

Dexmedetomidine administration might worsen septic AKI, while midazolam might preserve kidney function via the NFκΒ pathway.

The Pathophysiology of Sepsis-Associated AKI

Sepsis-associated AKI is a life-threatening complication that is associated with high morbidity and mortality in patients who are critically ill. Although it is clear early supportive interventions in sepsis reduce mortality, it is less clear that they prevent or ameliorate sepsis-associated AKI. This is likely because specific mechanisms underlying AKI attributable to sepsis are not fully understood. Understanding these mechanisms will form the foundation for the development of strategies for early diagnosis and treatment of sepsis-associated AKI. Here, we summarize recent laboratory and clinical studies, focusing on critical factors in the pathophysiology of sepsis-associated AKI: microcirculatory dysfunction, inflammation, NOD-like receptor protein 3 inflammasome, microRNAs, extracellular vesicles, autophagy and efferocytosis, inflammatory reflex pathway, vitamin D, and metabolic reprogramming. Lastly, identifying these molecular targets and defining clinical subphenotypes will permit precision approaches in the prevention and treatment of sepsis-associated AKI.

lncRNA GMDS‑AS1 upregulates IL‑6, TNF‑α and IL‑1β, and induces apoptosis in human monocytic THP‑1 cells via miR‑96‑5p/caspase 2 signaling

Long non-coding RNA (lncRNA) is considered a crucial modulator of the initiation and progression of several diseases. However, the roles of lncRNA in sepsis have yet to be fully elucidated. Thus, the aim of the present study was to investigate the effects of the lncRNA GDP-mannose 4,6-dehydratase antisense 1 (GMDS-AS1) and its target in order to understand its role in the pathogenesis of sepsis. An in vitro sepsis model was established by lipopolysaccharide (LPS) induction. Reverse transcription-quantitative PCR analysis was applied to detect the expression of inflammatory cytokines and the levels of GMDS-AS1, microRNA (miR)-96-5p and caspase-2 (CASP2). Flow cytometry was used to quantify the rate of apoptosis. In addition, the interaction between miR-96-5p and CASP2 was verified using a luciferase reporter assay. Western blot analysis was performed to assess the protein levels of CASP2 following alterations in GMDS-AS1 and miR-96-5p expression using transfection. The levels of interleukin (IL)-6, tumor necrosis factor-α and IL-1β were increased by LPS treatment in THP-1 cells, whereas miR-96-5p expression was downregulated. miR-96-5p overexpression inhibited LPS-induced inflammatory responses and apoptosis. In addition, GMDS-AS1 expression increased, and upregulation of GMDS-AS1 inhibited, the expression of miR-96-5p in the in vitro sepsis model. Moreover, CASP2 was confirmed to be a direct target of miR-96-5p. Therefore, the lncRNA GMDS-AS1 regulated inflammatory responses and apoptosis by modulating CASP2 and sponging miR-96-5p in LPS-induced THP-1 cells. In summary, the findings of the present study demonstrated that lncRNA GMDS-AS1 could promote the development of sepsis by targeting miR-96-5p/CASP2, indicating that the GMDS-AS1/miR-96-5p/CASP2 axis may be a new therapeutic target and potential research direction for sepsis therapy.

An Antioxidant Enzyme Therapeutic for Sepsis

Sepsis is a systemic inflammatory response syndrome caused by infections that may lead to organ dysfunction with high mortality. With the rapid increase in the aging population and antimicrobial resistance, developing therapeutics for the treatment of sepsis has been an unmet medical need. Excessive production of reactive oxygen species (ROS) during inflammation is associated with the occurrence of sepsis. We report herein a treatment for sepsis based on PEGylated catalase, which can effectively break down hydrogen peroxide, a key component of ROS that is chemically stable and able to diffuse around the tissues and form downstream ROS. PEGylated catalase can effectively regulate the cytokine production by activated leukocytes, suppress the elevated level of AST, ALT, TNF-α, and IL-6 in mice with induced sepsis, and significantly improve the survival rate.

A Potential Role of Vitamin D on Platelet Leukocyte Aggregation and Pathological Events in Sepsis: An Updated Review

Vitamin D deficiency and sepsis are both significant global health problems. Insufficient vitamin D is considered to be a pathogenically relevant factor of sepsis-related deaths; however, a causal relationship has not yet been demonstrated. Recently, vitamin D has been an exciting field of research owing to the identification of vitamin D receptors on many extra skeletal tissues and cells, suggesting an unexpected role on body physiology, beyond its effects on bone homeostasis. However, while the role of vitamin D on bone health is widely understood and has been successfully translated into clinical applications and public health policies, recent evidence supporting its role in other physiological and pathological processes has not been fully established. In sepsis, there is an induction of local intracellular vitamin D activity by most immune cells, including lymphocytes, macrophages, neutrophils, and dendritic cells, as well as vascular endothelial cells, to ensure efficient clearance of infective microorganisms and mediate anti-inflammatory and tolerogenic effects. The literature suggests an association between low vitamin D levels and sepsis, but clinical trials have yielded contradictory results. A greater understanding of this role may improve disease management. This article reviews the available knowledge regarding vitamin D in immune function, emerging literature regarding the association between its deficiency and sepsis, as well as presenting its potential effect on platelet leukocyte aggregations (PLAs), a significant pathology in sepsis. It also summarizes clinical trials involving vitamin D supplementation during critical illness and sepsis and addresses the impact of relevant factors of sepsis pathogenesis on the efficacy of vitamin D supplementation, which could contribute to the reported inconsistencies. Looking ahead, further studies are required to uncover the possible modulatory relationship between vitamin D and sepsis to define better cut-offs for its levels, proper timing of its administration, and the optimum dosage for best management.

Impact of serine protease inhibitor alpha1-antitrypsin on expression of endoplasmic reticulum stress-induced proinflammatory factors in adipocytes

Obesity-induced endoplasmic reticulum (ER) stress contributes to low-grade chronic inflammation in adipose tissue and may cause metabolic disorders such as diabetes mellitus and dyslipidemia. Identification of high serpina A1 (alpha-1 antitrypsin, A1AT) expression in mouse adipose tissue and adipocytes prompted us to explore the role of A1AT in the inflammatory response of adipocytes under ER stress. We aimed to determine the role of A1AT expression in adipocytes with ER stress during regulation of adipocyte homeostasis and inflammation. To this end, we chemically induced ER stress in A1AT small interfering RNA-transfected differentiating adipocytes using thapsigargin. Induction of CCAAT-enhancer-binding protein homologous protein (CHOP), an ER stress marker, by thapsigargin was lower in A1AT-deficient SW872 adipocytes. Thapsigargin or the proinflammatory cytokine tumor necrosis factor (TNF)α increased basal expression of cytokines such as interleukin (IL)-1β and IL-8 in both SW872 and primary omental adipocytes. This thapsigargin- or TNFα-induced expression of proinflammatory genes was increased by A1AT deficiency. These findings indicate that adipose A1AT may suppress the ER stress response to block excessive expression of proinflammatory factors, which suggests that A1AT protects against adipose tissue dysfunction associated with ER stress activation.

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Bip and CHOP expression responded to chemical ER stressor fluctuates in A1AT-silenced adipocytes.

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Chemical ER stressor- and TNFα-induced proinflammatory factor expression is increased by silencing of adipose A1AT expression.

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A1AT may protect against adipose tissue dysfunction through ER stress activation.

Systemic Chemotherapy is a Promising Treatment Option for Patients with Colonic Stents: A Review

Approximately 10% of patients with colorectal cancer (CRC) develop malignant large bowel obstruction (MLBO) at diagnosis. Furthermore, for 35% of patients with MLBO, curative primary tumor resection is unfeasible because of locally advanced disease and comorbidities. The practice of placing a self-expandable metallic stent (SEMS) has dramatically increased as an effective palliative treatment. Recent advances in systemic chemotherapy for metastatic CRC have significantly contributed to prolonging patients' prognosis and expanding the indications. However, the safety and efficacy of systemic chemotherapy in patients with SEMS have not been established. This review outlines the current status of this relatively new therapeutic strategy and future perspectives. Some reports on this topic have demonstrated that 1) systemic chemotherapy and the addition of molecular targeted agents contribute to prolonged survival in patients with SEMS; 2) delayed SEMS-related complications are a major concern, and this requires strict patient monitoring; however, primary tumor control by chemotherapy might result in decreased complications, especially regarding re-obstruction; and 3) using bevacizumab could be a risk factor for SEMS-related perforation, which may be lethal. Although this relatively new approach for unresectable stage IV obstructive CRC requires a well-planned clinical trial, this therapy could be promising for patients who are unideal candidates for emergency surgery and require immediate systemic chemotherapy.

Isoflurane reduces septic neuron injury by HO‑1‑mediated abatement of inflammation and apoptosis

Sepsis-associated encephalopathy (SAE) frequently occurs in critically ill patients with severe systemic infections. Subanesthetic isoflurane (0.7% ISO) possesses anti-inflammatory, antioxidant and anti-apoptotic properties against a number of human diseases, including brain injury. The activation of heme oxygenase-1 (HO-1) impedes inflammation, oxidation and apoptosis, thus alleviating sepsis-induced brain damage. However, whether 0.7% ISO affords protection against septic neuronal injury involving HO-1 activation is unclear. The present study aimed to investigate the neuroprotective effects of 0.7% ISO and its potential underlying mechanisms in SAE using a mouse model established by cecal ligation and puncture (CLP). The results indicated that the expression and activity of HO-1 in the mouse hippocampus were increased by CLP, and further enhanced by ISO. ISO reduced the death rate, brain water content and blood-brain barrier disruption, but improved the learning and memory functions of CLP-treated mice. ISO significantly decreased the production of pro-inflammatory cytokines and the levels of oxidative indictors in the serum and hippocampus, as well as the number of apoptotic neurons and the expression of pro-apoptotic proteins in the hippocampus. Inversely, anti-inflammatory factors, antioxidative enzymes and anti-apoptotic proteins were markedly increased by ISO administration. However, the neuroprotective effects of ISO were abolished by a HO-1 inhibitor. Overall, these findings suggested that 0.7% ISO alleviated SAE via its anti-inflammatory, antioxidative and anti-apoptotic properties, which involved the activated form of HO-1.

The activation of IL-17 signaling pathway promotes pyroptosis in pneumonia-induced sepsis

Background

Pyroptosis is closely relevant to sepsis. However, the molecular mechanisms of pyroptosis in pneumonia-induced sepsis are still not fully understood. Thus, this study aimed to find the specific molecular pathways associated with pyroptosis and explore their relationship in pneumonia-induced sepsis.

Methods

First, significant signaling pathways related to pneumonia-induced sepsis were screened by bioinformatics analysis based on GSE48080. The peripheral blood samples from patients with pneumonia-induced sepsis and healthy subjects were collected. Pneumonia-induced sepsis rat models were also established. Then, inflammatory response, pyroptosis, and regulatory T cells (Tregs)/T-helper 17 (Th17), Th1/Th2, and M1/M2 cell ratios in pneumonia-induced sepsis were evaluated.

Results

IL-17 signaling pathway was significantly related to pneumonia-induced sepsis by bioinformatics analysis. Compared with healthy groups, the higher of Th17/Treg, Th1/Th2 and M1/M2 cell radios in the patients and sepsis rat model indicated that pneumonia-induced sepsis caused a severe inflammatory response. This result was confirmed by higher levels of pro-inflammatory factors (IL-6, TNF-α, IL-1β, and IL-18) and an inflammation indicator (LDH), as well as pyroptosis occurrence in sepsis. Additionally, the up-regulation of key molecules (HMGB1, RAGE, IL-17A, TRAF6 and NK-κB) in the IL-17 signaling pathway suggested the IL-17 pathway was activated. Moreover, the release of IL-1β and IL-18 and the levels of the molecules (NLRP3, NLRC4, Cleaved caspase-1, and Cleaved GSDMD) associated with caspase-1-dependent pyroptosis were up-regulated in pneumonia-induced sepsis.

Conclusions

As NK-κB activation can promote the development of caspase-1-dependent pyroptosis, these findings suggested that the activation of the IL-17 signaling pathway could promote pyroptosis in pneumonia-induced sepsis.

Blood Galectin-3 Levels Predict Postoperative Complications after Colorectal Cancer Surgery

BACKGROUND

Recent studies suggested that galectin-3 may act as a pro-inflammatory damage-associated molecular pattern. The aim of this study is to investigate the association between blood galectin-3 and postoperative complications (POC) after colorectal cancer (CRC) surgery.

METHODS

Blood samples were taken from 35 patients with CRC before surgery, immediately after surgery, and on postoperative days (POD) 1, 3, 5, and 7. Blood galectin-3 and interleukin-6 levels were measured by commercially available ELISA. Patients were divided into those with (POC group) and without POC (no-POC group).

RESULTS

Significantly higher galectin-3 levels were observed pre- and postoperatively in the POC group (n=10) compared with those of the no-POC group (n=25). Galectin-3 levels on POD1 showed the best predictive potential for POC (cut-off: 3.18 pg/mL, area under the curve: 0.868).

CONCLUSIONS

These results indicate that increased perioperative blood galectin-3 levels may be associated with POC after CRC surgery.

Intravenous Immunoglobulin Attenuates Cecum Ligation and Puncture-Induced Acute Lung Injury by Inhibiting Apoptosis of Alveolar Epithelial Cells

PURPOSE

Intravenous immunoglobulin (IVIG) therapy has been used to treat sepsis, but its mechanisms of action remain unclear. Sepsis causes multiple organ failure, such as acute lung injury (ALI), which involves apoptosis of alveolar epithelial cells. In this study, we hypothesized that IVIG suppresses apoptosis in alveolar epithelial cells and evaluated mortality, cytokine levels, histological changes in the lung, and alveolar epithelial cell apoptosis after IVIG administration, in mice with experimentally induced sepsis.

METHODS

Mice received an injection of vehicle (saline) or immunoglobulin (100 mg/kg or 400 mg/kg) into the tail vein, after which they underwent cecal ligation and puncture. A sham-operated group was used as the normal control. Survival was assessed in all groups after 72 hours. Plasma levels of TNF-α and IL-6, histopathological changes and wet-to-dry ratio in lung, and alveolar epithelial cell apoptosis were evaluated in all groups at 4 hours after surgery.

RESULTS

In the vehicle group, histopathological injury of the lung was severe, and apoptosis of alveolar epithelial cells was significant. Survival and plasma cytokine levels were better in the IVIG treatment groups than in the vehicle group. IVIG 400 mg/kg suppressed apoptosis of alveolar epithelial cells and reduced ALI.

CONCLUSION

IVIG suppressed inflammatory cytokine levels and improved survival. Lung histopathology and alveolar epithelial cell apoptosis were improved by IVIG treatment, in a dose-dependent manner. Suppressing apoptosis in alveolar epithelial cells appears to be a mechanism by which IVIG improves survival.

Muscarinic M1 and M2 receptor subtypes play opposite roles in LPS-induced septic shock

BACKGROUND

To compare pharmacologic effects of pirenzepine and AF-DX116, a selective competitive antagonist for M1 and M2 subtype muscarinic cholinergic receptors (mAChRs), respectively, with atropine, a non-selective competitive antagonist for mAChRs, on Lipopolysaccharide (LPS).

METHODS

Male C57BL/6 mice were used to establish models of LPS-induced experimental endotoxemia. Mice were intraperitoneally injected 10 min prior to LPS injection with control (saline), atropine, pirenzepine and AF-DX116, respectively. Overall survival time was estimated using Kaplan-Meier plots. Inflammatory cytokine tumor necrosis factor-α (TNF-α) was monitored at various intervals after LPS injection and individual reagent administration. Pathological alternations in lungs and liver were analyzed.

RESULTS

Pirenzepine and atropine pretreatment improved survival rate of LPS-induced septic shock; in contrast, AF-DX116 accelerated death from sepsis. Moreover, TNF-α plasma level was decreased in response to pirenzepine or atropine, whereas increased in response to AF-DX116. Pirenzepine and atropine relieved whereas AF-DX116 accelerated LPS-induced pulmonary and hepatic injury. Pirenzepine reduced proportion of M1 subtype of macrophages, while AF-DX116 promoted polarization of macrophages to M1 subtype. Pirenzepine pretreatment reduced while AF-DX116 enhanced expression of SOCS3 at mRNA level.

CONCLUSIONS

The administration of pirenzepine and atropine may have beneficial effects on septic shock.

Preoperative lymphocyte-to-monocyte ratio predicts postoperative infectious complications after laparoscopic colorectal cancer surgery

BACKGROUND AND AIM

Postoperative infectious complications (POI), which can increase length of hospital stay, medical cost, and worsen overall survival, are a concern in minimally invasive colorectal cancer (CRC) surgeries. Recent reports showed that relatively new inflammation-based score, lymphocyte-to-monocyte ratio (LMR) is an independent predictor of long-term outcomes after CRC surgeries. In this study, LMR was evaluated as a predictor of short-term postoperative outcomes.

PATIENTS AND METHODS

This was a single-institutional retrospective study of 211 consecutive patients who had undergone laparoscopic CRC surgery with primary tumor resection from January 2014 to August 2015 at Nippon Medical School Chiba Hokusoh Hospital. The patients were divided into two groups (no POI; n = 176 and POI; n = 35). The associations between inflammation-based scores, namely neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and LMR, and the occurrence of POI were investigated. Receiving operator characteristic curve analysis was used to determine the cutoff point of preoperative LMR.

RESULTS

Low LMR (cut-off 3.46), long operative time, and smoking were found to be independent predictors of POI in a multivariate analysis (LMR: Odds ratio 5.61, 95% confidence interval 1.98-15.9, P = 0.001). Patients with low LMR also appeared to have more advanced and aggressive tumours.

CONCLUSION

This is the first study to report that the lower LMR is a predictive factor of POI after laparoscopic CRC surgery, and it may provide additional information for treatment decisions to prevent POI.

Recombinant human milk fat globule-EGF factor VIII (rhMFG-E8) as a therapy for sepsis after acute exposure to alcohol

BACKGROUND

Alcohol intake predisposes to infections and sepsis. Alcohol and sepsis inhibit the expression of milk fat globule epidermal growth factor-factor VIII (MFG-E8), a glycoprotein essential for optimal efferocytosis, resulting in the release of proinflammatory molecules and increased sepsis severity. We previously reported that recombinant mouse (rm) MFG-E8 attenuates sepsis-induced organ injury in rats with acute alcohol intoxication. In order to develop a therapy that can be safely used in humans, we have produced recombinant human (rh) MFG-E8 and evaluated its efficacy to ameliorate sepsis after acute exposure to alcohol.

METHODS

We induced acute alcohol intoxication with a bolus injection of alcohol (1.75 g/kg BW) followed by an intravenous infusion of 300 mg/kg/h alcohol for 10 h. Sepsis was then induced by cecal ligation and puncture (CLP). At -10, 0, and 10 h relative to CLP, rats received MFG-E8 or vehicle (albumin) intravenously. Animals were euthanized at 20 h after CLP for blood and tissue collection. Additional groups of animals were used for a survival study.

RESULTS

Compared to vehicle, rhMFG-E8 treatment ameliorated blood levels of proinflammatory cytokines (% improvement: TNF-α 49.8%, IL-6 34.7%) and endotoxin (61.7%), as well as of transaminases (AST 36.2%, ALT 40.1%) and lactate (18.4%). Rats treated with rhMFG-E8 also had a significant histological attenuation of the acute lung injury, as well as a reduction in the number of apoptotic cells in the thymus (43.4%) and cleaved caspase 3 (38.7%) in the spleen. In addition, rhMFG-E8 improved the 10-day sepsis survival rate from 45 to 80% CONCLUSION: rhMFG-E8 significantly ameliorated sepsis in rats with acute alcohol exposure, demonstrating rhMFG-E8's potential to be developed as an effective therapy for sepsis in alcohol abusers.

Preactivated and disaggregated shape-changed platelets protect kidney against from ischemia-reperfusion injury in rat through attenuating inflammation reaction

This study tested the hypothesis that preactivated and disaggregated shape-changed platelet (PreD-SCP) therapy significantly protected rat kidney from ischemia-reperfusion (IR) injury. Adult-male Sprague-Dawley rats (n = 24) were equally categorized into Groups 1 (sham-operated control [SC]), 2 (SC + PreD-SCP), 3 (IR only), and 4 (IR + PreD-SCP). By 72 hr after IR procedure, the circulatory levels of creatinine, blood urine nitrogen and inflammatory biomarkers (interleukin [IL]-6/tumor necrosis factor [TNF]-α), and ratio of urine protein to urine creatinine were significantly higher in Group 3 than in other groups and significantly higher in Group 4 than in Groups 1 and 2, but they showed no different between Groups 1 and 2 (all p < .001). The microscopic findings showed that the expressions of kidney injury score, cellular inflammation (MMP-9/CD14//F4/80), and fibrotic area were identical to the circulatory inflammation, whereas the integrity of podocyte components (ZO-1/synaptopodin/podocin) exhibited an opposite to circulatory inflammation among the four groups (all p < .0001). The protein expressions of inflammatory (TNF-α/IL-1ß/NF-κB/iNOS/TRAF6/MyD88/TLR-4), apoptotic/cell death (mitochondrial Bax/cleaved caspase-3/p-53), oxidized protein, mitogen-activated protein kinase family (p-38/p-JNK/p-c-JUN), and mitochondrial-damaged biomarkers displayed a similar pattern, whereas the antiapoptotic (Bcl-2/Bcl-XL) and integrity of mitochondrial biomarkers followed an opposite trend to circulatory inflammation among the four groups (all p < .001). PreD-SCP therapy effectively protected the kidney against IR injury.

Dexmedetomidine prevents septic myocardial dysfunction in rats via activation of α7nAChR and PI3K/Akt- mediated autophagy

BACKGROUND AND PURPOSE

Dexmedetomidine (Dex) has been shown to elicit cardio-protective effects in sepsis. The aim of this study was to investigate the role of autophagy in the protective effects of Dex and its possible mechanism in vivo and vitro.

EXPERIMENTAL APPROACH

6-8-week-old male Wistar rats were performed cecal ligation puncture (CLP) and administered 0.9% saline (CLP group), 50 μg/kg Dex (Dex group), Dex plus chloroquine (20 mg/kg; Dex + CQ group), or 40 μg/kg methyllycaconitin (Dex + MLA group), or 25 μM LY294002 (Dex + LY294002 group). After study, cardiac histology, cardiac function, level of autophagy, cardiomyocytes apoptosis and inflammatory mediators including protein IL-1β, IL-6, and TNF-α were measured. The LPS induced-H9C2 cardiomyocytes were treated with Dex, Dex + CQ and detected for cell apoptosis, autophagy level and cell cycle.

KEY RESULTS

CLP-induced sepsis resulted in cardiac dysfunction, apoptosis, and inflammatory response. Dex exhibited protective effects on the myocardium by the induction of myocardial autophagy and ameliorated the LPS-induced blockade of autophagic flux in H9C2 cells. CQ was found to significantly inhibit Dex-mediated protection of myocardial apoptosis and inflammation. CLP rats treated with Dex in combination with MLA, an antagonist of α7 nicotinic acetylcholine receptor (α7nAChR), exhibited decreased autophagy and increased inflammation and cell death, identifying α7nAchR was involved in the Dex-mediated pathway. In addition, we found that the PI3K/Akt pathway is involved in Dex-mediated autophagy and convergent with α7nAChR-mediated stimulation of autophagy response.

CONCLUSIONS AND IMPLICATIONS

For the first time, these data indicate that autophagy is central in Dex-mediated cardio-protection in sepsis. These observations provide the foundation for further study, and may serve as the basis for innovative therapeutic strategies against septic myocardial dysfunction.

Dexmedetomidine inhibits astrocyte pyroptosis and subsequently protects the brain in in vitro and in vivo models of sepsis

Sepsis is life-threatening and often leads to acute brain damage. Dexmedetomidine, an α₂-adrenoceptor agonist, has been reported to possess neuroprotective effects against various brain injury but underlying mechanisms remain elusive. In this study, in vitro and in vivo models of sepsis were used to explore the effects of dexmedetomidine on the inflammasome activity and its associated glia pyroptosis and neuronal death. In vitro, inflammasome activation and pyroptosis were found in astrocytes following lipopolysaccharide (LPS) exposure. Dexmedetomidine significantly alleviated astrocyte pyroptosis and inhibited histone release induced by LPS. In vivo, LPS treatment in rats promoted caspase-1 immunoreactivity in astrocytes and caused an increase in the release of pro-inflammatory cytokines of IL-1β and IL-18, resulting in neuronal injury, which was attenuated by dexmedetomidine; this neuroprotective effect was abolished by α₂-adrenoceptor antagonist atipamezole. Dexmedetomidine significantly reduced the high mortality rate caused by LPS challenge. Our data demonstrated that dexmedetomidine may protect glia cells via reducing pyroptosis and subsequently protect neurons, all of which may preserve brain function and ultimately improve the outcome in sepsis.

Alpha-7 Nicotinic Receptor-Targeted Cinobufagin Induces Antinociception and Inhibits NF-κB Signaling Pathway in DRG Neurons

Cinobufagin (CBG) has been shown to have antinociceptive properties. Nevertheless, the antinociceptive effect and mechanism of CBG are still unclear. The present study was designed to investigate the antinociceptive effect of CBG in the thermal and chemical pain models and further to explore the molecular target and potential signal pathway. As shown in the hot-plate test, formalin test, and acetic acid writhing test in mice, administration of CBG produced significant antinociceptive activity in a dose-dependent manner, and the antinociceptive effect was blocked by intraperitoneal pretreatment of methyllycaconitine citrate (an α7 nicotinic receptor antagonist) and intrathecal delivery of an α7 nicotinic receptor antagonist siRNA (α7-siRNA). Immunofluorescence demonstrated that the α7 nicotinic receptor and IκB/NF-κB were coexpressed in primary cultured lumbar DRG neurons. In the chemical pain models and primary cultured DRG neurons, Western blot analysis showed that the formation of p-IκB and p-NF-κB was regulated by CBG, and the effect of CBG was inhibited by α7-siRNA, and ELISA analysis indicated that CBG also regulated the expression of inflammatory cytokines through the α7 nicotinic receptor in DRG. These results suggest that CBG may activate an α7 nicotinic receptor, thereby triggering the inhibition of the DRG NF-κB signaling pathway, resulting in an antinociceptive effect in mice.

The Yin and Yang of Tyrosine Kinase Inhibition During Experimental Polymicrobial Sepsis

Neutrophils are the first cells of our immune system to arrive at the site of inflammation. They release cytokines, e.g., chemokines, to attract further immune cells, but also actively start to phagocytose and kill pathogens. In the case of sepsis, this tightly regulated host defense mechanism can become uncontrolled and hyperactive resulting in severe organ damage. Currently, no effective therapy is available to fight sepsis; therefore, novel treatment targets that could prevent excessive inflammatory responses are warranted. Src Family tyrosine Kinases (SFK), a group of tyrosine kinases, have been shown to play a major role in regulating immune cell recruitment and host defense. Leukocytes with SFK depletion display severe spreading and migration defects along with reduced cytokine production. Thus, we investigated the effects of dasatinib, a tyrosine kinase inhibitor, with a strong inhibitory capacity on SFKs during sterile inflammation and polymicrobial sepsis in mice. We found that dasatinib-treated mice displayed diminished leukocyte adhesion and extravasation in tumor necrosis factor-α-stimulated cremaster muscle venules in vivo. In polymicrobial sepsis, sepsis severity, organ damage, and clinical outcome improved in a dose-dependent fashion pointing toward an optimal therapeutic window for dasatinib dosage during polymicrobial sepsis. Dasatinib treatment may, therefore, provide a balanced immune response by preventing an overshooting inflammatory reaction on the one side and bacterial overgrowth on the other side.

Caspase-8 inhibition represses initial human monocyte activation in septic shock model

In septic patients, the onset of septic shock occurs due to the over-activation of monocytes. We tested the therapeutic potential of directly targeting innate immune cell activation to limit the cytokine storm and downstream phases. We initially investigated whether caspase-8 could be an appropriate target given it has recently been shown to be involved in microglial activation. We found that LPS caused a mild increase in caspase-8 activity and that the caspase-8 inhibitor IETD-fmk partially decreased monocyte activation. Furthermore, caspase-8 inhibition induced necroptotic cell death of activated monocytes. Despite inducing necroptosis, caspase-8 inhibition reduced LPS-induced expression and release of IL-1β and IL-10. Thus, blocking monocyte activation has positive effects on both the pro and anti-inflammatory phases of septic shock. We also found that in primary mouse monocytes, caspase-8 inhibition did not reduce LPS-induced activation or induce necroptosis. On the other hand, broad caspase inhibitors, which have already been shown to improve survival in mouse models of sepsis, achieved both. Thus, given that monocyte activation can be regulated in humans via the inhibition of a single caspase, we propose that the therapeutic use of caspase-8 inhibitors could represent a more selective alternative that blocks both phases of septic shock at the source.

Activated Mesenchymal Stem Cells Interact with Antibiotics and Host Innate Immune Responses to Control Chronic Bacterial Infections

Chronic bacterial infections associated with biofilm formation are often difficult to resolve without extended courses of antibiotic therapy. Mesenchymal stem cells (MSC) exert antibacterial activity in vitro and in acute bacterial infection models, but their activity in chronic infection with biofilm models has not been previously investigated. Therefore, we studied the effects of MSC administration in mouse and dog models of chronic infections associated with biofilms. Mice with chronic Staphylococcus aureus implant infections were treated by i.v. administration of activated or non-activated MSC, with or without antibiotic therapy. The most effective treatment protocol was identified as activated MSC co-administered with antibiotic therapy. Activated MSC were found to accumulate in the wound margins several days after i.v. administration. Macrophages in infected tissues assumed an M2 phenotype, compared to untreated infections which contained predominately M1 macrophages. Bacterial killing by MSC was found to be mediated in part by secretion of cathelicidin and was significantly increased by antibiotics. Studies in pet dogs with spontaneous chronic multi drug-resistant wound infections demonstrated clearance of bacteria and wound healing following repeated i.v. administration of activated allogeneic canine MSC. Thus, systemic therapy with activated MSC may be an effective new, non-antimicrobial approach to treatment of chronic, drug-resistant infections.

Milk fat globule-epidermal growth factor-factor VIII attenuates sepsis-induced acute kidney injury

BACKGROUND

Acute kidney injury (AKI) is most commonly caused by sepsis in critically ill patients, and it is associated with high morbidity and mortality. The pathophysiology of sepsis-induced AKI is generally accepted to include direct inflammatory injury, endothelial cell dysfunction, and apoptosis. Milk fat globule-epidermal growth factor-factor VIII (MFG-E8) is a secretory glycoprotein with a known role in the enhancement of apoptotic cell clearance and regulation of inflammation. We hypothesize that administration of recombinant mouse MFG-E8 (rmMFG-E8) can protect mice from kidney injuries caused by sepsis.

METHODS

Sepsis was induced in 8-wk-old male C57BL/6 mice by cecal ligation and puncture (CLP). rmMFG-E8 or phosphate-buffered saline (vehicle) was injected intravenously at a dosage of 20 μg/kg body weight at time of CLP (n = 5-8 mice per group). After 20 h, serum and renal tissue were harvested for various analyses. The renal injury markers blood urea nitrogen (BUN) and creatinine were determined by enzymatic and chemical reactions, respectively. The gene expression analysis was carried out by real-time quantitative polymerase chain reaction.

RESULTS

At 20 h after CLP, serum levels of BUN and creatinine were both significantly increased in the vehicle group compared with the sham group, whereas the mice treated with rmMFG-E8 had a significant reduction in BUN and creatinine levels by 28% and 24.1%, respectively (BUN: 197.7 ± 23.6 versus 142.3 ± 20.7 mg/dL; creatinine: 0.83 ± 0.12 versus 0.63 ± 0.06 mg/dL; P < 0.05). Expressions of novel biomarkers of renal tissue injury neutrophil gelatinase-associated lipocalin and kidney injury molecule-1 were also significantly downregulated by 58.2% and 95%, respectively, after treatment with rmMFG-E8. Proinflammatory cytokine interleukin-6 and tumor necrosis factor-α messenger RNA (mRNA) were significantly reduced by 50.8% and 50.3%, respectively, in rmMFG-E8-treated mice compared with vehicle-treated mice. The mRNA levels of the chemokines keratinocyte chemoattractant and macrophage inhibitory protein-2 were reduced by 85.1% and 78%, respectively, in mice treated with rmMFG-E8 compared with the vehicle mice. In addition, the expression of intercellular cell adhesion molecule-1 and platelet endothelial cell adhesion molecule-1 (PECAM-1/CD31) mRNA was downregulated by 35.6% and 77.8%, respectively, in rmMFG-E8-treated mice compared with the vehicle animals (P < 0.05).

CONCLUSIONS

Treatment with rmMFG-E8 reduces renal tissue injury induced by sepsis through inhibiting the production of proinflammatory cytokines and chemokine, as well as through the activation of endothelial cells. Thus, MFG-E8 may have a therapeutic potential for treating AKI induced by sepsis.

Neutrophil derived microparticles increase mortality and the counter-inflammatory response in a murine model of sepsis

Although advances in medical care have significantly improved sepsis survival, sepsis remains the leading cause of death in the ICU. This is likely due to a lack of complete understanding of the pathophysiologic mechanisms that lead to dysfunctional immunity. Neutrophil derived microparticles (NDMPs) have been shown to be the predominant microparticle present at infectious and inflamed foci in human models, however their effect on the immune response to inflammation and infection is sepsis has not been fully elucidated. As NDMPs may be a potential diagnostic and therapeutic target, we sought to determine the impact NDMPs on the immune response to a murine polymicrobial sepsis. We found that peritoneal neutrophil numbers, bacterial loads, and NDMPs were increased in our abdominal sepsis model. When NDMPs were injected into septic mice, we observed increased bacterial load, decreased neutrophil recruitment, increased expression of IL-10 and worsened mortality. Furthermore, the NDMPs express phosphatidylserine and are ingested by F4/80 macrophages via a Tim-4 and MFG-E8 dependent mechanism. Finally, upon treatment, NDMPs decrease macrophage activation, increase IL-10 release and decrease macrophage numbers. Altogether, these data suggest that NDMPs enhance immune dysfunction in sepsis by blunting the function of neutrophils and macrophages, two key cell populations involved in the early immune response to infection. This article is part of a Special Issue entitled: Immune and Metabolic Alterations in Trauma and Sepsis edited by Dr. Raghavan Raju.

A PPARγ AGONIST ENHANCES BACTERIAL CLEARANCE THROUGH NEUTROPHIL EXTRACELLULAR TRAP FORMATION AND IMPROVES SURVIVAL IN SEPSIS

Dysregulation of the inflammatory response against infection contributes to mortality in sepsis. Inflammation provides critical host defense, but it can cause tissue damage, multiple organ failure, and death. Because the nuclear transcription factor peroxisome proliferator-activated receptor γ (PPARγ) exhibits therapeutic potential, we characterized the role of PPARγ in sepsis. We analyzed severity of clinical signs, survival rates, cytokine production, leukocyte influx, and bacterial clearance in a cecal ligation and puncture (CLP) model of sepsis in Swiss mice. The PPARγ agonist rosiglitazone treatment improved clinical status and mortality, while increasing IL-10 production and decreasing TNF-α and IL-6 levels, and peritoneal neutrophil accumulation 24 h after CLP. We noted increased bacterial killing in rosiglitazone treated mice, correlated with increased generation of reactive oxygen species. Polymorphonuclear leukocytes (PMN) incubated with LPS or Escherichia coli and rosiglitazone increased peritoneal neutrophil extracellular trap (NET)-mediated bacterial killing, an effect reversed by the PPARγ antagonist (GW 9662) treatment. Rosiglitazone also enhanced the release of histones by PMN, a surrogate marker of NET formation, effect abolished by GW 9662. Rosiglitazone modulated the inflammatory response and increased bacterial clearance through PPARγ activation and NET formation, combining immunomodulatory and host-dependent anti-bacterial effects and, therefore, warrants further study as a potential therapeutic agent in sepsis.

SirT1 activator represses the transcription of TNF‑α in THP‑1 cells of a sepsis model via deacetylation of H4K16

Sepsis is a systemic inflammatory response resulting from the excessive production of pro-inflammatory cytokines, including tumor necrosis factor (TNF)-α. Sirtuin 1 (SirT1) actively deacetylates histone proteins, and facilitates chromatin compaction and gene silencing. In the present study, a cell model of sepsis, comprising lipopolysaccharide (LPS)-tolerant THP-1 cells, was used to investigate whether the SirT1 activator, resveratrol, repressed the transcription of TNF-α. Chromatin immunoprecipitation and real-time PCR were used to determine the transcription of the TNF-α promoter. The result revealed that the binding of SirT1 to the TNF-α promoter was decreased by LPS stimulation in normal cells. However, in LPS-tolerant cells, nuclear protein levels of SirT1 remained elevated, and LPS stimulation had no significant effect on the binding of SirT1 to the TNF-α promoter. However, the activity of SirT1 was increased and binding of ace-H4K16 to the TNF-α promoter was decreased with resveratrol treatment in the tolerant cells. It was concluded that resveratrol stimulated sirtuin activity in LPS-tolerant THP-1 cells, and repressed TNF-α transcription through the deacetylation of H4K16, without affecting the methylation of H3K9. Resveratrol offers potential as an infective candidate to alleviate inflammation in patients with sepsis.

Functional significance of exosomes applied in sepsis: A novel approach to therapy

The nanoparticles referred as exosomes play an active role in intercellular communication. Their potential positive therapeutic effect in bacterial inflammation and sepsis has been the subject of several studies that have examined the feasibility of exosomes as drug-delivery vehicles. The underlying mechanism of interest involves the selective transport of cellular cargo. Most attention has been focused on the exosome-mediated transport of microRNA and protein. Thus, exosomes are expected to be an important tool in the treatment of inflammatory disease. This review covers the relevant literature, focusing on the relationship between exosomes and sepsis and therapeutic use of exosomes in bacterially mediated inflammation or sepsis. We evaluate exosomes as drug vehicles, including their therapeutic cargo, potential mechanisms of action, choice of donor cells, and routes of administration.

Immunomodulatory and Antimicrobial Activity of Babassu Mesocarp Improves the Survival in Lethal Sepsis

Attalea speciosa syn Orbignya phalerata Mart. (babassu) has been used in the treatment of inflammatory and infectious diseases. Aim of the study. To investigate the antimicrobial and immunological activity of babassu mesocarp extract (EE). Material and Methods. The in vitro antimicrobial activity was evaluated by disk diffusion assay and by determination of the minimum inhibitory concentration (MIC) to Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus (MRSA). The flavonoids and phenolic acids content were determined by chromatography. The in vivo assays were performed in Swiss mice submitted to sepsis by cecal ligation and puncture (CLP). The mice received EE subcutaneously (125 or 250 mg/Kg), 6 hours after the CLP. The number of lymphoid cells was quantified and the cytokines production was determined by ELISA after 12 h. Results. EE was effective as antimicrobial to E. faecalis, S. aureus, and MRSA. EE is rich in phenolic acids, a class of compounds with antimicrobial and immunological activity. An increased survival can be observed in those groups, possibly due to a significant inhibition of TNF-α and IL-6. Conclusions. The EE showed specific antimicrobial activity in vitro and an important antiseptic effect in vivo possibly due to the antimicrobial and immunomodulatory activity.

Protective effect of recombinant Trichinella 53-kDa protein in sepsis and the effect on macrophages

The survival rate of the recombinant Trichinella 53-kDa protein infected by the cecal ligation and puncture (CLP) model of sepsis in rats and the expression difference of macrophages were analyzed. Eighteen clean SD rats were selected for the present study. The rats were divided into the sham operation (n=5), control (n=5) and experimental (n=8) groups. The rats in the sham operation group underwent cecum division and suture with routine therapy for cure. The rats in the control and experimental groups were placed in the CLP model of sepsis in rats. The experimental group was administered recombinant Trichinella 53-kDa protein in advance, and the control group was administered the same dose of placebo. The survival rate of the rats within 6 and 12 h, the macrophage expression ratio, and the differences of the expression levels Th1-type cytokines IFN-γ and tumor necrosis factor (TNF)-α, and the Th2 type cytokines interleukin-4 (IL-4) and IL-13 were analyzed. The survival rate of rats in the experimental group was higher than that of the control group with a statistically significant difference (P<0.05). The expression ratio of the macrophages received from the different handling methods of the rats in the experimental group was higher than that of the control group. The difference was statistically significant (P<0.05). The expression levels of the Th1-type cytokines IFN-γ and TNF-α of the rats in the experimental group was higher than that of the control group, while the expression level of the Th2-type cytokines IL-4 and IL-13 was higher than that of the control group. The difference was statistically significant (P<0.05). In conclusion, recombinant Trichinella 53-kDa protein can increase the survival rate following infection with CLP sepsis, which may be associated with the improvement of the macrophages and the adjustment of the expression of Th2 cytokines.

Recombinant Trichinella spiralis 53-kDa protein activates M2 macrophages and attenuates the LPS-induced damage of endotoxemia

Sepsis is a serious clinical condition of excessive systemic immune response to microbial infection. The pro-inflammatory stage of sepsis is generally launched by innate cells such as macrophages. They release inflammatory cytokines, activate other immune cells and cause severe tissue/organ damage. In this study, we have revealed that recombinant Trichinella spiralis (TS) excretory-secretory protein (rTsP53) exhibited anti-inflammatory properties and rescued mice from LPS-induced endotoxemia, which is a common model for sepsis study, potentially through the induction of M2 macrophages. rTsP53 treatment significantly decreased inflammatory cytokines (IL-6, IFN-γ and TNF-α) and increased IL-4, IL-10, IL-13 and TGF-β secretion, both in circulation and in tissues. rTsP53 also induced the activation and infiltration of F4/80(+)CD163(+) macrophages to inflammatory tissues, increased M2 macrophage-related Arg1 and Fizz1 expression, and decreased M1 macrophage-related iNOS expression. PCR array showed that rTsP53 activated several genes that involve the survival of macrophages and also anti-inflammatory genes such as SOCS3. Together, our results show that rTsP53 activates M2 macrophages, which has strong anti-inflammatory potential to prevent LPS-induced lethal sepsis.

Combined Therapy With Adipose-Derived Mesenchymal Stem Cells and Ciprofloxacin Against Acute Urogenital Organ Damage in Rat Sepsis Syndrome Induced by Intrapelvic Injection of Cecal Bacteria

We hypothesized that combined treatment with autologous adipose-derived mesenchymal stem cell (ADMSC) and ciprofloxacin is superior to ciprofloxacin only in reducing sepsis-induced urogenital organ damage and mortality in rat sepsis syndrome (SS) caused by intrapelvic injection of cecal bacteria (1.0 × 10(4) cells per milliliter; total, 5.0 ml). Male Sprague-Dawley rats (n = 60) equally divided into group 1 (sham-control), group 2 (SS), group 3 (SS-ADMSC [5.0 × 10(5) intravenously at 0.5, 6, and 18 hours after sepsis induction]), group 4 (SS-ciprofloxacin [3.0 mg/kg, b.i.d.] for 5 days), and group 5 (SS-ADMSC-ciprofloxacin) were sacrificed by day 5. Mortality rate and creatinine level were highest in group 2 and lowest in group 1 and significantly higher in groups 3 and 4 than those in group 5, but there was no difference between groups 3 and 4 (all p < .005). The kidney injury score, inflammatory biomarker expressions at protein (tumor necrosis factor-1α, nuclear factor-κB, matrix metallopeptidase-9, regulated on activation, normal T-cell expressed and secreted, interleukin-1β) and cellular (CD14+, migratory inhibitor factor positive, CD68+) levels in kidneys and urinary bladder were lowest in group 1 and highest in group 2, higher in group 4 than in groups 3 and 5, and higher in group 3 than in group 5 (all p < .001). Protein expressions of apoptosis (Bax, cleaved caspase 3 and poly[ADP-ribose] polymerase 1, p21 protein [Cdc42/Rac]-activated kinase 2) and oxidative stress (oxidized protein, NADPH oxidase (NOX)-1, NOX-2) in these organs showed an identical pattern compared with that of inflammation in all groups (all p < .001). In conclusion, ADMSC-assisted ciprofloxacin therapy offered an additional benefit by reducing acute urogenital organ damage in rat.

SIGNIFICANCE

Autologous adipose-derived mesenchymal stem cell-assisted ciprofloxacin therapy offered an additional benefit by reducing acute urogenital organ damage in rats.

Precision medicine for the treatment of severe pneumonia in intensive care

Despite advances in its management, community-acquired pneumonia (CAP) remains the most important cause of sepsis-related mortality and the reason for many ICU admissions. Severity assessment is the cornerstone of CAP patient management and the attempts to ensure the best site of care and therapy. Survival depends on a combination of host factors (genetic, age, comorbidities, defenses), pathogens (virulence, serotypes) and drugs. To reduce CAP mortality, early adequate antibiotic therapy is fundamental. The use of combination therapy with a macrolide seems to improve the clinical outcome in the subset of patients with high inflammation due to immunomodulation. Guidelines on antibiotic therapy have been associated with beneficial effects, and studies of newer adjunctive drugs have produced promising results. This paper discusses the current state of knowledge regarding of precision medicine and the treatment of severe CAP patients.

Impact of caspase-8 and PKA in regulating neutrophil-derived microparticle generation

The morbidity and mortality from sepsis continues to remain high despite extensive research into understanding this complex immunologic process. Further, while source control and antibiotic therapy have improved patient outcomes, many immunologically based therapies have fallen short. Microparticles (MPs) are intact vesicles that serve as mediators of intercellular communication as well as markers of inflammation in various disease processes. We have previously demonstrated that MPs can be produced at the infected foci during sepsis, are predominantly of neutrophil derivation (NDMPs) and can modulate immune cells. In this study, we sought to elucidate the molecular mechanisms underlying NDMP generation. Using thioglycolate (TGA) to recruit and activate neutrophils, we first determined that intra-peritoneal TGA increase NDMP accumulation. We next utilized TGA-elicited neutrophils in vitro to investigate signaling intermediates involved in NDMP production, including the intrinsic and extrinsic caspase pathways, cAMP dependent PKA and Epac activation as well as the role myosin light chain kinase (MLCK) as a final mediator of NDMP release. We observed that NDMP generation was dependent on the extrinsic caspase apoptotic pathway (caspase 3 and caspase 8), cAMP activation of PKA but not of Epac, and on activation of MLCK. Altogether, these data contribute to an overall framework depicting the molecular mechanisms that regulate NDMP generation.

Emerging therapeutic targets of sepsis-associated acute kidney injury

Sepsis-associated acute kidney injury (SA-AKI) is linked to high morbidity and mortality. To date, singular approaches to target specific pathways known to contribute to the pathogenesis of SA-AKI have failed. Because of the complexity of the pathogenesis of SA-AKI, a reassessment necessitates integrative approaches to therapeutics of SA-AKI that include general supportive therapies such as the use of vasopressors, fluids, antimicrobials, and target-specific and time-dependent therapeutics. There has been recent progress in our understanding of the pathogenesis and treatment of SA-AKI including the temporal nature of proinflammatory and anti-inflammatory processes. In this review, we discuss the clinical and experimental basis of emerging therapeutic approaches that focus on targeting early proinflammatory and late anti-inflammatory processes, as well as therapeutics that may enhance cellular survival and recovery. Finally, we include ongoing clinical trials in sepsis.

Procalcitonin, MR-Proadrenomedullin, and Cytokines Measurement in Sepsis Diagnosis: Advantages from Test Combination

BACKGROUND

Elevated cytokines levels correlate with sepsis severity and mortality but their role in the diagnosis is controversial, whereas Procalcitonin (PCT) has been largely used. Recently, the mid-regional proadrenomedullin (MR-proADM) has been combined with PCT for diagnosis optimization. In this study the combined measurement of PCT, MR-proADM, and cytokines in patients with sepsis was evaluated.

METHODS

One hundred and four septic patients and 101 controls were enrolled. Receiver operating characteristic (ROC) analysis and multiple logistic regression were used to evaluate applicant markers for sepsis diagnosis. Markers with best Odds Ratio (OR) were combined, and the posttest probability and a composite score were computed.

RESULTS

Based upon ROC curves analysis, PCT, MR-proADM, IL-6, IL-10, TNF-α, and MCP-1 were considered applicant for sepsis diagnosis. Among these PCT, MR-proADM , IL-6, and TNF-α showed the best OR. A better posttest probability was found with the combination of PCT with MR-proADM and PCT with IL-6 or TNF-α compared to the single marker. A composite score of PCT, MR-proADM, and TNF-α showed the best ROC curve in the early diagnosis of sepsis.

CONCLUSION

The combination of PCT with other markers should expedite diagnosis and treatment of sepsis optimizing clinical management.

Milk fat globule-epidermal growth factor-factor VIII downregulates interleukin-17 expression in sepsis by modulating STAT3 activation

BACKGROUND

Milk fat globule-epidermal growth factor-factor VIII (MFG-E8) is a secretory glycoprotein with a known role in inflammation. In sepsis, interleukin (IL)-17 acts as a proinflammatory cytokine to exaggerate systemic inflammation. We hypothesize that MFG-E8 downregulates IL-17 expression in sepsis.

METHODS

Sepsis was induced in 8-week-old male C57BL/6 mice by cecal ligation and puncture (CLP). Recombinant mouse MFG-E8 (rmMFG-E8) at a dosage of 20 μg/kg body weight or phosphate-buffered saline was concurrently injected. After 10 hours, blood and spleen samples were harvested for analysis. For in vitro studies, splenocytes isolated from healthy mice pretreated with rmMFG-E8 and splenocytes from MFG-E8 knockout (mfge8(-/-)) mice were stimulated with phorbol 12-myristate 13-acetate (PMA) and ionomycin, followed by measurement of IL-17 expression with either quantitative PCR or enzyme-linked immunosorbent assay.

RESULTS

At 10 hours after CLP, rmMFG-E8 inhibited the elevated levels of IL-17 protein in serum by 31%, compared with the vehicle. In the spleen, rmMFG-E8 reduced the upregulated IL-17 mRNA and protein levels by 81% and 51%, respectively. This correlated with a significant reduction in organ injury markers AST and ALT in sepsis after administration of rmMFG-E8. In vitro treatment of splenocytes isolated from healthy mice with rmMFG-E8 showed significant downregulation in PMA/ionomycin-induced IL-17 expression. In contrast, CD4 T-cells from mfge8(-/-) mice showed significant upregulation of IL-17 compared with wild-type mice. The phosphorylated level of signal transducer and activator of transcription 3 (STAT3) was downregulated in spleen tissue of septic mice treated with rmMFG-E8. Conversely, mfge8(-/-) mice showed increased phosphorylated STAT3 compared with wild-type mice after sepsis.

CONCLUSION

Our findings demonstrate MFG-E8-mediated downregulation of IL-17 expression, implicating its potential as a novel therapeutic agent against sepsis.

Improved emergency myelopoiesis and survival in neonatal sepsis by caspase-1/11 ablation

Over one million newborns die annually from sepsis with the highest mortality in premature and low-birthweight infants. The inflammasome plays a central role in the regulation of innate immunity and inflammation, and is presumed to be involved in protective immunity, in large part through the caspase-1-dependent activation of interleukin-1β (IL-1β) and IL-18. Studies in endotoxic shock, however, suggest that endogenous caspase-1 activity and the inflammasome contribute to mortality primarily by promoting excessive systemic inflammatory responses. We examined whether caspase-1 and the inflammasome also regulate neonatal inflammation, host protective immunity and myelopoiesis during polymicrobial sepsis. Neonatal (5-7 days) C57BL/6 and caspase-1/11(-/-) mice underwent a low-lethality caecal slurry model of intra-abdominal sepsis (LD25-45 ). Ablation of caspase-1/11, but not apoptosis-associated speck-like protein containing a CARD domain or nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3), improved neonatal survival following septic challenge compared with wild-type mice (P < 0·001), with decreased concentrations of inflammatory cytokines in the serum and peritoneum. Surprisingly, caspase-1/11(-/-) neonates also exhibited increased bone marrow and splenic haematopoietic stem cell expansion (P < 0·001), and increased concentrations of granulocyte and macrophage colony-stimulating factors in the peritoneum (P < 0·001) after sepsis. Ablation of caspase-1/11 signalling was also associated with increased recruitment of peritoneal macrophages and neutrophils (P < 0·001), increased phagocytosis by neutrophils (P = 0·003), and decreased bacterial colonization (P = 0·02) in the peritoneum. These findings suggest that endogenous caspase-1/11 activity, independent of the NLRP3 inflammasome, not only promotes the magnitude of the inflammatory response, but also suppresses protective immunity in the neonate, so contributing to innate immune dysfunction and poor survival in neonatal sepsis.

The transcription factor GFI1 negatively regulates NLRP3 inflammasome activation in macrophages

Interleukin-1β (IL-1β) secretion downstream of Toll-like receptor (TLR) activation is tightly controlled at the transcriptional and post-translational levels. NLRP3 inflammasome is involved in the maturation of pro-IL-1β, with NLRP3 expression identified as the limiting factor for inflammasome activation. Previously, we had demonstrated that the zinc-finger protein GFI1 inhibits pro-IL-1β transcription. Here, we show that GFI1 inhibits NLRP3 inflammasome activation and IL-1β secretion in macrophages. GFI1 suppressed Nlrp3 transcription via two mechanisms: (1) by binding to the Gli-responsive element 1 (GRE1) in the Nlrp3 promoter; and (2) by antagonizing the nuclear factor-κB (NF-κB) transcriptional activity. Thus, GFI1 negatively regulates TLR-mediated IL-1β production at both transcriptional and post-translational levels.

Revisiting caspases in sepsis

Sepsis is a life-threatening illness that occurs due to an abnormal host immune network which extends through the initial widespread and overwhelming inflammation, and culminates at the late stage of immunosupression. Recently, interest has been shifted toward therapies aimed at reversing the accompanying periods of immune suppression. Studies in experimental animals and critically ill patients have demonstrated that increased apoptosis of lymphoid organs and some parenchymal tissues contributes to this immune suppression, anergy and organ dysfunction. Immediate to the discoveries of the intracellular proteases, caspases for the induction of apoptosis and inflammation, and their striking roles in sepsis have been focused elaborately in a number of original and review articles. Here we revisited the different aspects of caspases in terms of apoptosis, pyroptosis, necroptosis and inflammation and focused their links in sepsis by reviewing several recent findings. In addition, we have documented striking perspectives which not only rewrite the pathophysiology, but also modernize our understanding for developing novel therapeutics against sepsis.

Apoptotic adipose-derived mesenchymal stem cell therapy protects against lung and kidney injury in sepsis syndrome caused by cecal ligation puncture in rats

Introduction

We tested the hypothesis that apoptotic adipose-derived mesenchymal stem cells (A-ADMSC) are superior to healthy (H)-ADMSC in attenuating cecal ligation puncture (CLP)-induced sepsis-mediated lung and kidney injuries.

Methods

Adult male rats divided into group 1 (sham controls), group 2 (CLP), group 3 [CLP + H-ADMSC administered at 0.5, 6, and 18 hours after CLP], and group 4 [CLP + A-ADMSC administered as in group 3] were sacrificed 72 hours after CLP with blood, lung, and kidney collected for studies.

Results

White blood cell (WBC) count, circulating TNF-α and creatinine levels were higher in groups 2 and 3 than in groups 1 and 4 (all P < 0.001). Kidney and lung damage scores were highest in group 2, lowest in group 1, significantly higher in group 3 than in group 4 (all P < 0.0001). Protein expressions of inflammatory (ICAM-1, MMP-9, TNF-α, NF-κB), oxidative, and apoptotic (Bax, caspase-3, PARP) biomarkers were higher in groups 2 and 3 than groups 1 and 4, whereas anti-apoptotic (Bcl-2) and mitochondrial integrity (cytochrome-C) biomarkers were lower in groups 2 and 3 than in groups 1 and 4 (all P < 0.001). Expressions of anti-oxidant biomarkers at protein (GR, GPx, NQO-1, HO-1) and cellular (GR, GPx) levels were highest in group 4 (all P < 0.001). The number of inflammatory cells (CD3+) in lungs and levels of DNA damage marker (γ-H2AX) in kidneys were higher in groups 2 and 3 than in groups 1 and 4 (all P < 0.001).

Conclusions

A-ADMSC therapy was superior to H-ADMSC therapy in protecting major organs from damage in rats with CLP-induced sepsis syndrome.

HS-23, Lonicera japonica extract, attenuates septic injury by suppressing toll-like receptor 4 signaling

ETHNOPHARMACOLOGICAL RELEVANCE

Lonicera japonica Thunberg is a traditional herbal medicine widely used in East Asia as an anti-bacterial, anti-inflammatory, and antiviral agent. This study was designed to investigate the effects of HS-23, ethanol extract of the dried flower buds of Lonicera japonica, in experimental models of sepsis and elucidate the mechanisms of action of HS-23.

MATERIALS AND METHODS

Male ICR mice were intravenously administered HS-23 (20 and 40 mg/kg) for 0 (immediately) and 24 h after cecal ligation and puncture (CLP) for survival tests, and HS-23 (40 mg/kg) immediately after CLP for biochemical assays.

RESULTS

HS-23 improved sepsis-induced mortality, enhanced bacterial clearance, and attenuated multiple organ failure. The mechanisms of action of HS-23 included attenuation of increased toll-like receptor (TLR)4 protein and mRNA expression. HS-23 suppressed sepsis-induced increases in protein expression of myeloid differentiation primary response protein 88, p38 and c-Jun N-terminal kinase in both liver and lung, as well as TIR-domain-containing adapter-inducing interferon-β and interferon regulatory transcription factor 3 protein expression in liver.

CONCLUSION

The results of this study revealed that HS-23 attenuated sepsis through suppression of TLR signaling pathways. Therefore, our findings suggest that HS-23 might be useful as a potential therapeutic agent for treatment of sepsis.