Sepsis: Current Definition, Pathophysiology, Diagnosis, and Management

Role of corticosteroids in the treatment of critically ill sepsis patients: a meta-analysis review

OBJECTIVE

It was to systematically evaluate the effect of corticosteroids on 28d all-cause mortality (ACM), in-hospital death rate, and ICU death rate in critically ill sepsis patients.

METHODS

PubMed, Embase, and Medline databases were used to screen the published literatures on the therapeutic effect of corticosteroids in the treatment of critically ill sepsis patients. After evaluating the quality of the included literatures, RevMan 5.3 software was used for meta-analysis. 4524 literatures regarding the application of corticosteroids to treat critically ill sepsis patients were preliminarily searched. After screening was carried out, 9 literatures were finally included. 2,850 patients were treated with corticosteroids and 2867 patients were treated with placebo.

RESULTS

The meta-analysis of the effect of corticosteroids versus placebo on 28dACM showed [OR = 0.87, 95% CI 0.78-0.98, Z = 2.22, P = 0.03], P < 0.05; the meta-analysis of the outcome of corticosteroids versus placebo on ICU death rate showed [OR = 0.77, 95% CI 0.63-0.94, Z = 2.60, P = 0.009], P < 0.05; and the meta-analysis of the effect of corticosteroids versus placebo on in-hospital death rate showed [OR = 0.80, 95% CI 0.66-0.96, Z = 2.34, P = 0.002], P < 0.05.

CONCLUSION

In summary, corticosteroids can reduce the death rate of critically ill sepsis patients to a certain extent and have good clinical application value.

The early predictive roles of NLR and NE% in in-hospital mortality of septic patients

Background

This study aimed to retrospectively investigate the early predictive value of inflammation-related parameters in-hospital mortality of septic patients.

Methods

We retrospectively recruited 606 patients from Wuhan Union Hospital from January 2009 to October 2022. The inflammation-related parameters including neutrophil-to-lymphocyte ratio (NLR), neutrophil percentage (NE%), platelet-to-lymphocyte ratio (PLR), and monocyte-to-lymphocyte ratio (MLR) in survivals and non-survivals on day 1, 2, 3 and 7 after hospitalization were collected and analyzed.

Results

NLR and NE% in non-survivals (n = 185) were significantly higher than those in survivals (n = 421). The area under the receiver operating characteristic curve (AUC) of NLR or NE% was 0.880 or 0.852 on day 1, 0.770 or 0.790 on day 2, 0.784 or 0.777 on day 3, and 0.732 or 0.741 on day 7. The optimal cut-off values of NLR or NE% for predicting in-hospital mortality were 10.769 or 87.70% on day 1, 17.544 or 90.69% on day 2, 14.395 or 85.00% on day 3, and 9.105 or 83.93% on day 7. The day 1, 2 and 3 NLR and NE% were significant predictors of in-hospital mortality in the Cox proportional hazards models.

Conclusions

NLR ≥10.769 and NE% ≥ 87.70% could be used early biomarkers for predicting in-hospital mortality of septic patients.

TLR9 Knockdown Alleviates Sepsis via Disruption of MyD88/NF-κB Pathway Activation

Sepsis is a life-threatening organ dysfunction due to dysregulated host response to infection, accompanied by a high rate of mortality worldwide. During sepsis progression, toll-like receptors (TLRs) play essential roles in the aberrant inflammatory response that contributes to sepsis-related mortality. Here, we demonstrated a critical role of TLR9 in the progression of sepsis. A septic mouse model was established by cecal ligation and puncture (CLP), then administered with lentivirus encoding si-TLR9/LY294002. TLR9 protein expression and p65 nuclear translocation level/TLR9 protein positive expression/interaction between TLR9 and myeloid differentiation primary response protein 88 (MyD88) in the cecal tissues were examined by Western blot/immunohistochemistry/co-immunoprecipitation assays. Serum levels of pro-inflammatory factors [e.g., interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α)] as well as bacterial contents in the liver/spleen/mesenteric lymph nodes (MLN) were measured by ELISA and bacterial mobility assay. TLR9 expression was augmented in the cecal tissues, TLR9 and MyD88 interaction was enhanced, nuclear p65 protein level was increased, cytoplasmic p65 protein level was decreased, and the nuclear factor kappa B (NF-κB) pathway was activated in CLP-induced septic mice, while TLR9 knockout protected against CLP-induced sepsis via the MyD88/NF-κB pathway inactivation. Briefly, TLR9 inhibition-mediated protection against CLP-induced sepsis was associated with a reduction in pro-inflammatory cytokine release and a promotion of bacterial clearance via a mechanism involving the MyD88/NF-κB pathway inactivation.

The effects of etomidate on expression of high mobility group box 1 via the nuclear factor kappa B pathway in rat model of sepsis

Etomidate is an anesthetic agent used in hemodynamically unstable patients, but its use has been controversial in septic patients. The response of high-mobility group box 1 (HMGB1), a late-phase lethal cytokine in sepsis, to etomidate has not been reported. This study investigated the effects of etomidate on the expression and release of HMGB1 and the underlying mechanism using a cecal ligation and puncture (CLP) model. Thirty-six male Sprague-Dawley rats were divided into sham, CLP, and Etomi groups. Sepsis was induced in the CLP and Etomi groups, and intravenous etomidate (4 mg/kg) was infused for 40 min immediately after operation in the Etomi group. Serum creatinine, alanine aminotransferase (ALT), tumor necrosis factor (TNF)-α, interleukin (IL)-6, and HMGB1 levels were measured 6 and 24 hours after surgery. Activation of nuclear factor (NF)-ĸB and HMGB1 mRNA expression in the liver, lung, kidney, and ileum tissues were measured, and immunohistochemical staining of HMGB1 was implemented. Increases of the TNF-α level 6 h after CLP and ALT and IL-6 levels 24 h after CLP were significantly inhibited by etomidate treatment. Etomidate treatment also significantly attenuated the increase in serum HMGB1 level at 6 and 24 h after CLP and suppressed the NF-ĸB and HMGB1 mRNA in multiple organs 24 h after CLP. Immunohistochemical staining also revealed that etomidate treatment inhibited HMGB1 expression. Etomidate inhibited the systemic release of HMGB1 and its expression in various organs. The mechanism may be associated with the inhibitory effects of etomidate on pro-inflammatory cytokine release and NF-ĸB activity.

Polypeptide from Moschus Suppresses Lipopolysaccharide-Induced Inflammation by Inhibiting NF-κ B-ROS/NLRP3 Pathway

OBJECTIVE

To examine the anti-inflammatory effects and potential mechanisms of polypeptide from Moschus (PPM) in lipopolysaccharide (LPS)-induced THP-1 macrophages and BALB/c mice.

METHODS

The polypeptide was extracted from Moschus and analyzed by high-performance liquid chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Subsequently, LPS was used to induce inflammation in THP-1 macrophages and BALB/c mice. In LPS-treated or untreated THP-1 macrophages, cell viability was observed by cell counting kit 8 and lactate dehydrogenase release assays; the proinflammatory cytokines and reactive oxygen species (ROS) were measured by enzyme-linked immunosorbent assay and flow cytometry, respectively; and protein and mRNA levels were measured by Western blot and real-time quantitative polymerase chain reaction (qRT-PCR), respectively. In LPS-induced BALB/c mice, the proinflammatory cytokines were measured, and lung histology and cytokines were observed by hematoxylin and eosin (HE) and immunohistochemical (IHC) staining, respectively.

RESULTS

The SDS-PAGE results suggested that the molecular weight of purified PPM was in the range of 10-26 kD. In vitro, PPM reduced the production of interleukin 1β (IL-1β), IL-18, tumor necrosis factor α (TNF-α), IL-6 and ROS in LPS-induced THP-1 macrophages (P<0.01). Western blot analysis demonstrated that PPM inhibited LPS-induced nuclear factor κB (NF-κB) pathway and thioredoxin interacting protein (TXNIP)/nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain containing 3 (NLRP3) inflammasome pathway by reducing protein expression of phospho-NF-κB p65, phospho-inhibitors of NF-κB (Iκ Bs) kinase α/β (IKKα/β), TXNIP, NLRP3, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), and pro-caspase-1 (P<0.05 or P<0.01). In addition, qRT-PCR revealed the inhibitory effects of PPM on the mRNA levels of TXNIP, NLRP3, ASC, and caspase-1 (P<0.05 or P<0.01). Furthermore, in LPS-induced BALB/c mice, PPM reduced TNF-α and IL-6 levels in serum (P<0.05 or P<0.01), decreased IL-1β and IL-18 levels in the lungs (P<0.01) and alleviated pathological injury to the lungs.

CONCLUSION

PPM could attenuate LPS-induced inflammation by inhibiting the NF-κB-ROS/NLRP3 pathway, and may be a novel potential candidate drug for treating inflammation and inflammation-related diseases.

METTL3 achieves lipopolysaccharide-induced myocardial injury via m6A-dependent stabilization of Myh3 mRNA

Septic cardiomyopathy (SCM) was an important pathological component of severe sepsis and septic shock. N6-methyladenosine (m6A) modification was a common RNA modification in both mRNA and non-coding RNAs and was proved to be involved in sepsis and immune disorders. Therefore, the purpose of this study was to investigate the role and mechanism of METTL3 in lipopolysaccharide-induced myocardial injury. We firstly analyzed the expression changes of various m6A-related regulators in human samples in the GSE79962 data and the Receiver Operating Characteristic curve of significantly changed m6A enzymes, showing that METTL3 had a high diagnostic ability in patients with SCM. Western blotting confirmed the high expression of METTL3 in LPS-treated H9C2 cells, which was consistent with the above results in human samples. In vitro and in vivo, the deficiency of METTL3 could improve the cardiac function, cardiac tissue damage, myocardial cell apoptosis and reactive oxygen species levels in LPS-treated H9C2 cells and LPS-induced sepsis rats, respectively. In addition, we obtained 213 differential genes through transcriptome RNA-seq analysis, and conducted GO enrichment analysis and KEGG pathway analysis through DAVID. We also found that the half-life of Myh3 mRNA was significantly reduced after METTL3 deletion and that Myh3 carried several potential m6A modification sites. In conclusion, we found that downregulation of METTL3 reversed LPS-induced myocardial cell and tissue damage and reduced cardiac function, mainly by increasing Myh3 stability. Our study revealed a key role of METTL3-mediated m6A methylation in septic cardiomyopathy, which may offer a potential mechanism for the therapy of septic cardiomyopathy.

Global, regional, and national burden of digestive diseases: findings from the global burden of disease study 2019

Background

The global burden of digestive diseases has been rising in the last 30 years. The rates and trends of incidence, deaths, and disability-adjusted life-years (DALYs) for digestive diseases need to be investigated.

Methods

We extracted the data on overall digestive diseases and by cause between 1990-2019 from the Global Burden of Diseases 2019 website, including the absolute number and the corresponding age-standardized rates of incidence (ASIR), deaths (ASDR), and DALYs (ASDALYs).

Results

Globally, the incident cases, deaths, and DALYs of digestive diseases in 2019 increased by 74.44, 37.85, and 23.46%, respectively, compared with that in 1990, with an increasing ASIR of 0.09%, as well as decreasing ASDR and ASDALYs of 1.38 and 1.32% annually. The sociodemographic index (SDI) of overall digestive diseases showed a slight increase in ASIR from low to middle-low regions. The downtrend in ASDR and ASDALYs was found in all SDI regions. The burden of incidence was higher in females, while the burden of deaths and DALYs was higher in males for the overall digestive diseases and most causes. The estimated annual percentage changes were significantly associated with the baseline ASIR, ASDR, and ASDALYs for the overall digestive diseases, and the negative correlations between ASDR, ASDALYs, and human development index both in 1990 (R = -0.68, R = -0.69) and 2019 (R = -0.71, R = -0.73) were noticed.

Conclusion

The findings indicate that digestive diseases remain a significant public health burden, with substantial variation across countries, sexes, and age groups. Therefore, implementing age, gender, and country-specific policies for early screening and targeted interventions could significantly reduce the global burden of digestive diseases.

A risk nomogram for predicting prolonged intensive care unit stays in patients with chronic obstructive pulmonary disease

Background

Providing intensive care is increasingly expensive, and the aim of this study was to construct a risk column line graph (nomograms)for prolonged length of stay (LOS) in the intensive care unit (ICU) for patients with chronic obstructive pulmonary disease (COPD).

Methods

This study included 4,940 patients, and the data set was randomly divided into training (n = 3,458) and validation (n = 1,482) sets at a 7:3 ratio. First, least absolute shrinkage and selection operator (LASSO) regression analysis was used to optimize variable selection by running a tenfold k-cyclic coordinate descent. Second, a prediction model was constructed using multifactorial logistic regression analysis. Third, the model was validated using receiver operating characteristic (ROC) curves, Hosmer-Lemeshow tests, calibration plots, and decision-curve analysis (DCA), and was further internally validated.

Results

This study selected 11 predictors: sepsis, renal replacement therapy, cerebrovascular disease, respiratory failure, ventilator associated pneumonia, norepinephrine, bronchodilators, invasive mechanical ventilation, electrolytes disorders, Glasgow Coma Scale score and body temperature. The models constructed using these 11 predictors indicated good predictive power, with the areas under the ROC curves being 0.826 (95%CI, 0.809-0.842) and 0.827 (95%CI, 0.802-0.853) in the training and validation sets, respectively. The Hosmer-Lemeshow test indicated a strong agreement between the predicted and observed probabilities in the training (χ² = 8.21, p = 0.413) and validation (χ² = 0.64, p = 0.999) sets. In addition, decision-curve analysis suggested that the model had good clinical validity.

Conclusion

This study has constructed and validated original and dynamic nomograms for prolonged ICU stay in patients with COPD using 11 easily collected parameters. These nomograms can provide useful guidance to medical and nursing practitioners in ICUs and help reduce the disease and economic burdens on patients.

Anti-inflammatory Effect of Low-Intensity Ultrasound in Septic Rats

OBJECTIVE

Sepsis is a severe systemic inflammatory response caused by infection. Here, the spleen region of Sprague-Dawley (SD) rats with sepsis was irradiated with low-intensity ultrasound (LIUS) to explore the regulation of inflammation and its mechanism by LIUS.

METHODS

In this study, 30 rats used for survival analysis were randomly divided into the sham-operated group (Sham, n = 10), the group in which sepsis was induced by cecal ligation and puncture (CLP, n = 10) and the group treated with LIUS immediately after CLP (LIUS, n = 10). The other 120 rats were randomly divided into the aforementioned three groups for detection at each time point. The parameters used in the LIUS group were 200 mW/cm², 0.37 MHz, 20% duty cycle and 20 min, and no ultrasonic energy was produced in the Sham and CLP groups. Seven-day survival rate, histopathology and expression of inflammatory factors and proteins were evaluated in the three groups.

RESULTS

LIUS was able to improve the survival rate of septic SD rats (p < 0.05), significantly inhibit the expression of tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), interleukin 6 (IL-6) and nuclear factor-κB p65 (NF-κB p65) (p < 0.05) and restore the ultrastructure of the spleen.

CONCLUSION

Our study determined that LIUS can relieve spleen damage and alleviate severe cytokine storm to improve survival outcomes in septic SD rats, and its mechanism may be related to the inhibition of the NF-κB signaling pathway by downregulation of IL-1β.

Bazedoxifene attenuates intestinal injury in sepsis by suppressing the NF-κB/NLRP3 signaling pathways

Acute inflammatory injury is the primary cause of sepsis, leading to various organ failures. Bazedoxifene (BAZ) has been proven to have anti-inflammatory effects. However, its effects on sepsis-induced intestinal injury are unclear. Here, we demonstrated the beneficial effects of BAZ on intestinal injury and explored the underlying mechanisms using cecal ligation and perforation (CLP)-mediated sepsis mouse model and in vitro cultured intestinal epithelial MODE-K cells. We found that BAZ elevated the survival rate of septic mice and attenuated CLP-triggered intestinal damage. BAZ inhibited intestinal inflammation and restored the impaired intestinal barriers in CLP mice. The mechanistic study in lipopolysaccharide (LPS)/adenosine triphosphate (ATP)-stimulated MODE-K cells showed that BAZ significantly downregulated the expression of NOD-like receptor protein 3 (NLRP3), interleukin-1β (IL-1β), caspase-1, and gasdermin D (GSDMD), and markedly reduced the phosphorylation of molecules in the nuclear factor kappa B (NF-κB) pathway. Moreover, BAZ prominently rescued the decreased viability of MODE-K cells and reduced lactate dehydrogenase (LDH) release upon LPS/ATP challenge. However, BAZ did not affect the inflammasome assembly, as evidenced by the lack of changes in ASC (apoptosis speck-like protein containing a CARD) speck formation. Our results suggest that BAZ relieves inflammation and intestinal barrier function disruption by suppressing the NF-κB/NLRP3 signaling pathways. Therefore, BAZ is a potential therapeutic candidate for treating intestinal injury in sepsis.

NMDARs antagonist MK801 suppresses LPS-induced apoptosis and mitochondrial dysfunction by regulating subunits of NMDARs via the CaM/CaMKII/ERK pathway

Lipopolysaccharide (LPS) displays a robust immunostimulatory ability upon Toll-like receptor 4 (TLR4) recognition. N-methyl-D-aspartate receptors (NMDARs) are highly compartmentalized in most cells and implicated in various inflammatory disorders. However, the relationship between TLR4 and NMDARs has not been explored deeply. This study aimed to examine the role of NMDARs and its specific inhibitor MK801 in LPS-treated endothelial cell dysfunction and the related mechanism in vivo and in vitro. The results showed that pre-treatment with MK801 significantly decreased LPS-induced cell death, cellular Ca²⁺, cellular reactive oxygen species, and glutamate efflux. Moreover, MK801 restrained LPS-induced mitochondrial dysfunction by regulating mitochondrial membrane potential and mitochondrial Ca²⁺ uptake. The oxygen consumption, basal and maximal respiration rate, and ATP production in LPS-treated HUVECs were reversed by MK801 via regulating ATP synthesis-related protein SDHB2, MTCO1, and ATP5A. The molecular pathway involved in MK801-regulated LPS injury was mediated by phosphorylation of CaMKII and ERK and the expression of MCU, MCUR1, and TLR4. LPS-decreased permeability in HUVECs was improved by MK801 via the Erk/ZO-1/occluding/Cx43 axis. Co-immunoprecipitation assay and western blotting showed three subtypes of NMDARs, NMDAζ1, NMDAε2, and NMDAε4 were bound explicitly to TLR4, suppressed by LPS, and promoted by MK801. Deficiency of NMDAζ1, NMDAε2, or NMDAε4 induced cell apoptosis, Ca²⁺ uptake, ROS production, and decreased basal and maximal respiration rate, and ATP production, suggesting that NMDARs integrity is vital for cell and mitochondrial function. In vivo investigation showed MK801 improved impairment of vascular permeability, especially in the lung and mesentery in LPS-injured mice. Our study displayed a novel mechanism and utilization of MK801 in LPS-induced ECs injury and permeability.

Aldehyde Dehydrogenase 2 Ameliorates LPS-Induced Acute Kidney Injury through Detoxification of 4-HNE and Suppression of the MAPK Pathway

Lipopolysaccharide (LPS)-induced septic acute kidney injury (AKI) is determined as a devastating organ dysfunction elicited by an inappropriate response to infection with high morbidity and mortality rates. Previous evidence has illustrated an indispensable role of mitochondrial aldehyde dehydrogenase 2 (ALDH2) in the pathogenesis of sepsis-induced multiorgan abnormalities. Specifically, this study investigated the potential role of ALDH2 in sepsis-induced AKI. After LPS administration, we observed a significant decline in renal function, increased inflammatory cytokines, oxidative stress, 4-hydroxy-2-nonenal (4-HNE) accumulation, and apoptosis via MAPK activation in ALDH2^-/- mice; in contrast, pretreatment with Alda-1 (an ALDH2 activator) alleviated the LPS-induced dysfunctions in mice. Moreover, in vitro analysis revealed that ALDH2 overexpression in mouse tubular epithelial cells (mTECs) improved the inflammatory response, oxidative stress, 4-HNE accumulation, and apoptosis via MAPK inhibition, whereas ALDH2 knockdown in mTECs aggravated these parameters via MAPK activation. Therefore, ALDH2 may protect against LPS-induced septic AKI by suppressing 4-HNE/MAPK pathway.

Potential Antioxidant Multitherapy against Complications Occurring in Sepsis

Septic shock currently represents one of the main causes of mortality in critical patient units with an increase in its incidence in recent years, and it is also associated with a high burden of morbidity in surviving patients. Within the pathogenesis of sepsis, oxidative stress plays an important role. The excessive formation of reactive oxygen species (ROS) leads to mitochondrial damage and vasomotor dysfunction that characterizes those patients who fall into septic shock. Currently, despite numerous studies carried out in patients with septic shock of different causes, effective therapies have not yet been developed to reduce the morbidity and mortality associated with this pathology. Despite the contribution of ROS in the pathophysiology of sepsis and septic shock, most studies performed in humans, with antioxidant monotherapies, have not resulted in promising data. Nevertheless, some interventions with compounds such as ascorbate, N-acetylcysteine, and selenium would have a positive effect in reducing the morbidity and mortality associated with this pathology. However, more studies are required to demonstrate the efficacy of these therapies. Taking into account the multifactorial features of the pathophysiology of sepsis, we put forward the hypothesis that a supplementation based on the association of more than one antioxidant compound should result in a synergistic or additive effect, thus improving the beneficial effects of each of them alone, potentially serving as a pharmacological adjunct resource to standard therapy to reduce sepsis complications. Therefore, in this review, it is proposed that the use of combined antioxidant therapies could lead to a better clinical outcome of patients with sepsis or septic shock, given the relevance of oxidative stress in the pathogenesis of this multi-organ dysfunction.

QKI degradation in macrophage by RNF6 protects mice from MRSA infection via enhancing PI3K p110β dependent autophagy

Background

Sepsis is a fatal condition commonly caused by Methicillin-resistant Staphylococcus aureus (MRSA) with a high death rate. Macrophages can protect the host from various microbial pathogens by recognizing and eliminating them. Earlier we found that Quaking (QKI), an RNA binding protein (RBP), was involved in differentiation and polarization of macrophages. However, the role of QKI in sepsis caused by pathogenic microbes, specifically MRSA, is unclear. This study aimed to investigate the role of QKI in regulation of host–pathogen interaction in MRSA-induced sepsis and explored the underlying mechanisms.

Methods

Transmission electron microscope and immunofluorescence were used to observe the autophagy level in macrophages. Real-time PCR and western blot were used to analyzed the expression of mRNA and protein respectively. The potential protein interaction was analyzed by iTRAQ mass spectrometry and Immunoprecipitation. RNA fluorescence in situ hybridization, dual-luciferase reporter assay and RNA immunoprecipitation were used to explore the mechanism of QKI regulating mRNA of PI3K-p110β.

Results

The mRNA level of QKI was aberrantly decreased in monocytes and PBMCs of septic patients with the increasing level of plasma procalcitonin (PCT). Then the mice with myeloid specific knockout of QKI was challenged with MRSA or Cecal Ligation and Puncture (CLP). Mice in these two models displayed higher survival rates and lower bacterial loads. Mechanistically, QKI deletion promoted phagocytosis and autophagic degradation of MRSA via activating p110β (a member of Class IA phosphoinositide 3-kinases) mediated autophagic response. QKI expression in macrophages led to the sequestration of p110β in mRNA processing (P) bodies and translational repression. Upon infection, the direct interaction of RNF6, a RING-type E3 ligase, mediated QKI ubiquitination degradation and facilitated PI3K-p110β related autophagic removal of pathogen. The administration of nanoparticles with QKI specific siRNA significantly protected mice from MRSA infection.

Conclusions

This study disclosed the novel function of QKI in the P body mRNA regulation during infection. QKI degradation in macrophage by RNF6 protects mice from MRSA infection via enhancing PI3K-p110β dependent autophagy. It suggested that QKI may serve as a potential theranostic marker in MRSA-induced sepsis.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13578-022-00865-9.

Deoxyelephantopin alleviates lipopolysaccharide-induced septic lung injury through inhibiting NF-ĸB/STAT3 axis

Sepsis induces multiple organ dysfunction syndromes, such as acute kidney, liver, or lung injury. Septic lung injury is associated with excessive apoptosis and inflammatory responses in hepatocytes. Deoxyelephantopin is a sesquiterpene lactone found in Elephantopus scaber L, and has immunomodulatory, antibacterial, anti-inflammatory, and antifungal properties. The role of deoxyelephantopin in sepsis-associated lung injury was investigated. First, human bronchial epithelial cells (BEAS-2B) and human pulmonary artery endothelial cells (HPAEC) were treated with lipopolysaccharide to induce cytotoxicity. Treatment with lipopolysaccharide reduced cell viability of BEAS-2B and HPAEC, and promoted cell apoptosis through down-regulation of poly (ADP-ribose) polymerase (PARP) and B-cell lymphoma 2 (Bcl-2), and up-regulation of cleaved PARP and B-cell lymphoma-associated X protein (Bax). Second, lipopolysaccharide-treated BEAS-2B and HPAEC were incubated with increasing concentrations of deoxyelephantopin, that is, 1, 5, or 10 μM. Deoxyelephantopin enhanced cell viability and reduced cell apoptosis of lipopolysaccharide-treated BEAS-2B and HPAEC. Third, deoxyelephantopin attenuated lipopolysaccharide-induced decrease of superoxide dismutase and glutathione, and increase of malondialdehyde and myeloperoxidase in BEAS-2B and HPAEC. Moreover, deoxyelephantopin also weakened lipopolysaccharide-induced increase of tumor necrosis factor-α, interleukin (IL)-1β, and IL-6. Finally, deoxyelephantopin decreased protein expression of p-p65 and p-signal transducer and activator of transcription 3 (STAT3) in lipopolysaccharide-treated BEAS-2B and HPAEC. In conclusion, deoxyelephantopin exhibited anti-oxidative and anti-inflammatory effects against lipopolysaccharide-treated BEAS-2B and HPAEC through inactivation of nuclear factor kappa B/STAT3 signaling.

STING signaling sensing of DRP1-dependent mtDNA release in kupffer cells contributes to lipopolysaccharide-induced liver injury in mice

Aberrant pro-inflammatory activation of Kupffer cells (KCs) is strongly involved in the pathogenesis of septic liver injury. Recent evidence indicates the crucial roles of excessive stimulator of interferon genes (STING) signaling activation during sepsis. However, the role of STING signaling in septic liver injury remains unclear. In this study, we demonstrated that STING signaling was markedly activated in KCs isolated from wild type mice after lipopolysaccharide (LPS) treatment. STING deficiency effectively protected liver function, attenuated systemic inflammatory response and decreased mortality in LPS-treated mice, which were aggravated by STING agonist (DMXAA). Importantly, STING signaling activation in KCs contributed to LPS-induced liver injury through promoting hepatocyte death. Mechanistically, STING signaling could be activated by release of mitochondrial DNA (mtDNA) through dynamin-related protein 1 (DRP1)-dependent mitochondrial fission in LPS-treated KCs. Additionally, LPS stimulation enhanced DRP1-dependent mitochondrial ROS production, which promoted the leak of mtDNA into the cytosol and subsequent STING signaling activation in KCs. The in vivo experiments showed that pharmacological inhibition of DRP1 with Mdivi-1 partially prevented the activation of STING signaling in KCs isolated from LPS-challenged mice, as well as alleviated liver injury and inhibited systemic inflammatory response. In summary, our study comprehensively confirmed that STING signaling senses the DRP1-dependent release of mtDNA in KCs and its activation might play a key role in LPS-induced liver injury, which offers new sights and therapeutic targets for management of septic liver injury.

Lipid-Enriched Parenteral Nutrition and Bloodstream Infections in Hospitalized Patients: Is It a Real Concern?

Today, few clinicians are still convinced that lipids are sepsis risk factors in patients receiving parenteral nutrition. This dogma is principally based on old literature. This review deals with the most recent literature search that provided up-to-date data over the past ten years. Systematic research was performed on Pubmed, MEDLINE, and Web of Science. The recent evidence does not justify the exclusion of lipid emulsions in patients receiving parenteral nutrition for fear of bloodstream infection risk. Moreover, lipids represent a substantial proportion of the energy source providing essential fatty acids, potentially improving clinical outcomes in patients often malnourished. Understanding the actual risk factors of sepsis during parenteral nutrition is necessary to optimize patient nutritional status and care and avoid essential fatty acid deficiency. There is an urgent need to make updated nutrition training available at all levels of medical education.

High Mobility Group Proteins in Sepsis

Sepsis, a systemic inflammatory response disease, is the most severe complication of infection and a deadly disease. High mobility group proteins (HMGs) are non-histone nuclear proteins binding nucleosomes and regulate chromosome architecture and gene transcription, which act as a potent pro-inflammatory cytokine involved in the delayed endotoxin lethality and systemic inflammatory response. HMGs increase in serum and tissues during infection, especially in sepsis. A growing number of studies have demonstrated HMGs are not only cytokines which can mediate inflammation, but also potential therapeutic targets in sepsis. To reduce sepsis-related mortality, a better understanding of HMGs is essential. In this review, we described the structure and function of HMGs, summarized the definition, epidemiology and pathophysiology of sepsis, and discussed the HMGs-related mechanisms in sepsis from the perspectives of non-coding RNAs (microRNA, long non-coding RNA, circular RNA), programmed cell death (apoptosis, necroptosis and pyroptosis), drugs and other pathophysiological aspects to provide new targets and ideas for the diagnosis and treatment of sepsis.

Non-Coding RNA Networks as Potential Novel Biomarker and Therapeutic Target for Sepsis and Sepsis-Related Multi-Organ Failure

According to “Sepsis-3” consensus, sepsis is a life-threatening clinical syndrome caused by a dysregulated inflammatory host response to infection. A rapid identification of sepsis is mandatory, as the extent of the organ damage triggered by both the pathogen itself and the host’s immune response could abruptly evolve to multiple organ failure and ultimately lead to the death of the patient. The most commonly used therapeutic strategy is to provide hemodynamic and global support to the patient and to rapidly initiate broad-spectrum empiric antibiotic therapy. To date, there is no gold standard diagnostic test that can ascertain the diagnosis of sepsis. Therefore, once sepsis is suspected, the presence of organ dysfunction can be assessed using the Sepsis-related Organ Failure Assessment (SOFA) score, although the diagnosis continues to depend primarily on clinical judgment. Clinicians can now rely on several serum biomarkers for the diagnosis of sepsis (e.g., procalcitonin), and promising new biomarkers have been evaluated, e.g., presepsin and adrenomedullin, although their clinical relevance in the hospital setting is still under discussion. Non-codingRNA, including long non-codingRNAs (lncRNAs), circularRNAs (circRNAs) and microRNAs (miRNAs), take part in a complex chain of events playing a pivotal role in several important regulatory processes in humans. In this narrative review we summarize and then analyze the function of circRNAs-miRNA-mRNA networks as putative novel biomarkers and therapeutic targets for sepsis, focusing only on data collected in clinical settings in humans.

Sepsis and Thrombocytopenia: A Nowadays Problem

Sepsis is a life-threatening organ failure produced by a dysregulated host response to infection that involves 15.6% of hospital mortality. The most common signs and symptoms of sepsis are hypotension, tachypnea, fever, and leukocytosis, whether suspected or confirmed. Including a major one, thrombocytopenia is a sign that is an independent predictor of poor outcomes in patients with sepsis, increasing their mortality rate and their length of stay in the intensive care unit (ICU). So far, the ongoing treatment for this problem is securing the airway, treating hypoxemia, and providing vascular access for hydration, antibiotic delivery, and vasopressors, if needed. This article has reviewed the different possible mechanisms found for sepsis-associated thrombocytopenia, going from the most acknowledged one as decreased platelet production to the potential aftermath of sepsis itself as disseminated intravascular coagulation (DIC). This article has also discussed the future treatment for patients suffering from thrombocytopenia and sepsis, going from phase I and II trials as GI antagonists to the well-known drug aspirin as a possible treatment for this problem.

SP1 Promotes HDAC4 Expression and Inhibits HMGB1 Expression to Reduce Intestinal Barrier Dysfunction, Oxidative Stress, and Inflammatory Response after Sepsis

As a serious and elusive syndrome caused by infection, sepsis causes a high rate of mortality around the world. Our investigation aims at exploring the role and possible mechanism of specificity protein-1 (SP1) in the development of sepsis. A mouse model of sepsis was established by cecal ligation perforation, and a cellular model was stimulated by lipopolysaccharide (LPS), followed by determination of the SP1 expression. It was determined that SP1 was poorly expressed in the intestinal tissues of septic mice and LPS-treated cells. Next, we examined the interactions among SP1, histone deacetylase 4 (HDAC4), and high mobility group box 1 (HMGB1) and found that SP1 bound to the HDAC4 promoter to upregulate its expression, thereby promoting the deacetylation of HMGB1. Meanwhile, gain- or loss-of-function approaches were applied to evaluate the intestinal barrier dysfunction, oxidative stress, and inflammatory response. Overexpression of SP1 or underexpression of HMGB1 was observed to reduce intestinal barrier dysfunction, oxidative stress, and inflammatory injury. Collectively, these experimental data provide evidence reporting that SP1 could promote the HDAC4-mediated HMGB1 deacetylation to reduce intestinal barrier dysfunction, oxidative stress, and inflammatory response induced by sepsis, providing a novel therapeutic target for sepsis prevention and treatment.

Blood long non-coding RNA intersectin 1-2 is highly expressed and links with increased Th17 cells, inflammation, multiple organ dysfunction, and mortality risk in sepsis patients

Background

Long non‐coding RNA intersectin 1–2 (lnc‐ITSN1‐2) exacerbates inflammation and promotes T‐helper (Th) cell differentiation, also serves as a biomarker in critical illness diseases. However, its clinical role in sepsis remains obscure. Hence, the study aimed to explore the relationship of lnc‐ITSN1‐2 with Th cells, inflammation, disease severity, multiple organ dysfunction, and mortality risk in sepsis.

Methods

Peripheral blood mononuclear cells (PBMC) were isolated from 95 sepsis patients and 50 health controls, followed by lnc‐ITSN1‐2 evaluation using RT‐qPCR. PBMC Th1, Th17 cells and their secreted cytokines in serum were detected by flow cytometry and ELISA, respectively.

Results

Lnc‐ITSN1‐2 in sepsis patients was higher than it in health controls (Z = −7.328, p < 0.001). Lnc‐ITSN1‐2 correlated with increased interferon‐gamma (p = 0.009), Th17 cells (p = 0.022), and interleukin‐17A (p = 0.006), but not Th1 cells (p = 0.169) in sepsis patients. Moreover, lnc‐ITSN1‐2 had a positive connection with C‐reactive protein (p = 0.001), acute pathologic and chronic health evaluation (APACHE) II (p = 0.024), and sequential organ failure assessment (SOFA) scores (p = 0.022). Regarding SOFA subscales, lnc‐ITSN1‐2 linked with elevated respiratory system score (p = 0.005), cardiovascular system score (p = 0.007), and renal system score (p = 0.004) but no other subscales. Besides, lnc‐ITSN1‐2 had an increasing trend, but no statistical difference, in septic deaths compared to survivors (Z = −1.852, p = 0.064).

Conclusion

Lnc‐ITSN1‐2 reflects sepsis progression and unfavorable prognosis to some extent, which may serve as a potential biomarker to improve the management of sepsis patients.

Elevated Serum HE4 Concentrations and Risk of Cardiac Complications among Hospitalized Patients with Burns

BACKGROUND

The decrease in effective blood volume after burns is closely related to abnormal heart function.

OBJECTIVE

To investigate whether serum human epididymis protein 4 (HE4), an indicator of early renal injury, contributes to increased risk of cardiac complications in patients with burns.

METHODS

Within 24 hours after hospital admission, clinical condition assessment and biochemical testing in patients with burns were performed. Multivariate analysis was performed by evaluating the relationship between serum HE4 levels and risk of cardiac complications (cardiac insufficiency, arrhythmia, and myocardial infarction) during hospitalization.

RESULTS

The number (percentage) of cardiac complications in all included patients with burns was 80 (15.6%). The results of sensitivity analysis suggest that elevated serum HE4 levels were related to higher risk of cardiac complications in patients with sepsis (OR = 2.1; 95% CI, 1.19-3.17; P <.001) and in patients without sepsis (OR = 2.29; 95% CI, 1.33-4.71l; P = .005), respectively, after adjustments for clinical confounding factors were made. Sepsis did not have a modification effect on the association between serum and cardiac complications among these patients. Also, the results of ROC curve analysis showed that serum HE4 levels have good predictive value for predicting cardiac complications in patients with burns (AUC = 0.708; 95% CI, 0.61-0.81; P <.001).

CONCLUSIONS

In the current study, we identified that elevated HE4 levels contributed to increased risk of cardiac complications in the hospital in patients with burns. This novel finding suggests that burn patients with serum HE4 may provide the opportunity to predict cardiac complications before hospital admission.

miR-34b-5p promotes renal cell inflammation and apoptosis by inhibiting aquaporin-2 in sepsis-induced acute kidney injury

OBJECTIVE

This study was designed to uncover the mechanism of miR-34b-5p-mediated aquaporin-2 (AQP2) in sepsis-induced injury using human renal tubular epithelial cells (HK-2).

METHODS

Serum levels of miR-34b-5p, TNF-α, IL-1β, IL-6, serum creatinine (SCr), and blood urea nitrogen (BUN) in septic patients with acute kidney injury (AKI) and healthy controls were detected. Lipopolysaccharide (LPS) was used to induce sepsis in HK-2 cells. LPS-induced HK-2 cells were transfected with miR-34b-5p inhibitor, miR-34b-5p mimic, pcDNA3.1-AQP2, si-AQP2, miR-34b-5p inhibitor + si-NC, or miR-34b-5p inhibitor + si-AQP2. The expressions of miR-34b-5p, AQP2, Bax, Bcl-2, cleaved caspase-3, TNF-α, IL-1β, and IL-6 in HK-2 cells were detected. TUNEL staining revealed the apoptosis of HK-2 cells. Dual-luciferase reporter assay verified the binding between miR-34b-5p and AQP2.

RESULTS

The expression of miR-34b-5p and the inflammatory responses were augmented in septic AKI patients. miR-34b-5p was up-regulated and AQP2 was down-regulated in LPS-induced HK-2 cells. miR-34b-5p inhibition or AQP2 overexpression ameliorated apoptosis and inflammation in LPS-induced HK-2 cells. In contrast, overexpressing miR-34b-5p deteriorated LPS-induced injury in HK-2 cells. AQP2 was a downstream target of miR-34b-5p. AQP2 silencing abolished the suppressive effects of miR-34b-5p inhibition on LPS-induced apoptosis and inflammatory response in HK-2 cells.

CONCLUSION

miR-34b-5p inhibits AQP2 to promote LPS-induced injury in HK-2 cells.

Mechanisms of Immunothrombosis by SARS-CoV-2

SARS-CoV-2 contains certain molecules that are related to the presence of immunothrombosis. Here, we review the pathogen and damage-associated molecular patterns. We also study the imbalance of different molecules participating in immunothrombosis, such as tissue factor, factors of the contact system, histones, and the role of cells, such as endothelial cells, platelets, and neutrophil extracellular traps. Regarding the pathogenetic mechanism, we discuss clinical trials, case-control studies, comparative and translational studies, and observational studies of regulatory or inhibitory molecules, more specifically, extracellular DNA and RNA, histones, sensors for RNA and DNA, as well as heparin and heparinoids. Overall, it appears that a network of cells and molecules identified in this axis is simultaneously but differentially affecting patients at different stages of COVID-19, and this is characterized by endothelial damage, microthrombosis, and inflammation.

Selective Extracellular Signal-Regulated Kinase 1/2 (ERK1/2) Inhibition by the SCH772984 Compound Attenuates In Vitro and In Vivo Inflammatory Responses and Prolongs Survival in Murine Sepsis Models

Sepsis is the leading cause of death in intensive care units worldwide. Current treatments of sepsis are largely supportive and clinical trials using specific pharmacotherapy for sepsis have failed to improve outcomes. Here, we used the lipopolysaccharide (LPS)-stimulated mouse RAW264.7 cell line and AlphaLisa assay for TNFa as a readout to perform a supervised drug repurposing screen for sepsis treatment with compounds targeting epigenetic enzymes, including kinases. We identified the SCH772984 compound, an extracellular signal-regulated kinase (ERK) 1/2 inhibitor, as an effective blocker of TNFa production in vitro. RNA-Seq of the SCH772984-treated RAW264.7 cells at 1, 4, and 24 h time points of LPS challenge followed by functional annotation of differentially expressed genes highlighted the suppression of cellular pathways related to the immune system. SCH772984 treatment improved survival in the LPS-induced lethal endotoxemia and cecal ligation and puncture (CLP) mouse models of sepsis, and reduced plasma levels of Ccl2/Mcp1. Functional analyses of RNA-seq datasets for kidney, lung, liver, and heart tissues from SCH772984-treated animals collected at 6 h and 12 h post-CLP revealed a significant downregulation of pathways related to the immune response and platelets activation but upregulation of the extracellular matrix organization and retinoic acid signaling pathways. Thus, this study defined transcriptome signatures of SCH772984 action in vitro and in vivo, an agent that has the potential to improve sepsis outcome.

Propensity-Score Analysis Reveals that Sex is Not a Prognostic Factor for Mortality in Intensive Care Unit-Admitted Patients with Septic Bacteremia

OBJECTIVE

Men have been considered to have a higher incidence of infectious diseases, with controversy over the possibility that sex could influence the prognosis of the infection. This study aimed to explore this assumption in patients admitted to the intensive care unit (ICU) with septic bacteremia.

METHODS

A retrospective analysis (2006-2017) of septic patients with microbiologically confirmed bacteremia (n=440) was performed. Risk of ICU and in-hospital mortality in males versus females was compared by univariate analysis and a propensity score analysis integrating their clinical characteristics.

RESULTS

Sepsis more frequently occurred in males (80.2% vs 76.1%) as well as in-hospital (48.0% vs 41.3%) and ICU (39.9% vs 36.5%) mortality. Univariate analyses showed that males had a higher Charlson comorbidity index and worse McCabe prognostic score. However, the propensity score in 296 matched patients demonstrated that females had higher risk of both ICU (OR 1.39; 95% CI 0.89-2.19) and in-hospital mortality (OR 1.18; 95% CI 0.77-1.83), but without statistical significance.

CONCLUSION

Males with sepsis had worse clinical characteristics when admitted to the ICU, but sex had no influence on mortality. These data contribute to helping reduce the sex-dependent gap present in healthcare provision.

Immune Intervention in Sepsis

Sepsis is a host immune disorder induced by infection. It can lead to multiple organ dysfunction syndrome (MODS), which has high morbidity and mortality. There has been great progress in the clinical diagnosis and treatment of sepsis, such as improvements in pathogen detection technology, innovations regarding anti-infection drugs, and the development of organ function support. Abnormal immune responses triggered by pathogens, ranging from excessive inflammation to immunosuppression, are recognized to be an important cause of the high mortality rate. However, no drugs have been approved specifically for treating sepsis. Here, we review the recent research progress on immune responses in sepsis to provide a theoretical basis for the treatment of sepsis. Constructing and optimizing a dynamic immune system treatment regimen based on anti-infection treatment, fluid replacement, organ function support, and timely use of immunomodulatory interventions may improve the prognosis of sepsis patients.

ICU-Mortality in Old and Very Old Patients Suffering From Sepsis and Septic Shock

Purpose: Old (>64 years) and very old (>79 years) intensive care patients with sepsis have a high mortality. In the very old, the value of critical care has been questioned. We aimed to compare the mortality, rates of organ support, and the length of stay in old vs. very old patients with sepsis and septic shock in intensive care.

Methods: This analysis included 9,385 patients, from the multi-center eICU Collaborative Research Database, with sepsis; 6184 were old (aged 65–79 years), and 3,201 were very old patients (aged 80 years and older). A multi-level logistic regression analysis was used to fit three sequential regression models for the binary primary outcome of ICU mortality. A sensitivity analysis in septic shock patients (n = 1054) was also conducted.

Results: In the very old patients, the median length of stay was shorter (50 ± 67 vs. 56 ± 72 h; p < 0.001), and the rate of a prolonged ICU stay was lower (>168 h; 9 vs. 12%; p < 0.001) than the old patients. The mortality from sepsis was higher in very old patients (13 vs. 11%; p = 0.005), and after multi-variable adjustment being very old was associated with higher odds for ICU mortality (aOR 1.32, 95% CI 1.09–1.59; p = 0.004). In patients with septic shock, mortality was also higher in the very old patients (38 vs. 36%; aOR 1.50, 95% CI 1.10–2.06; p = 0.01).

Conclusion: Very old ICU-patients suffer from a slightly higher ICU mortality compared with old ICU-patients. However, despite the statistically significant differences in mortality, the clinical relevance of such minor differences seems to be negligible.

Aldehyde Dehydrogenase 2 Protects Against Lipopolysaccharide-Induced Myocardial Injury by Suppressing Mitophagy

Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. Sepsis-induced circulatory and cardiac dysfunction is associated with high mortality rates. Mitophagy, a specific form of autophagy, is excessively activated in lipopolysaccharide-induced myocardial injury. The present study investigated whether aldehyde dehydrogenase 2 (ALDH2) regulates mitophagy in sepsis-induced myocardial dysfunction. After lipopolysaccharide administration, cardiac dysfunction, inflammatory cell infiltration, biochemical indicators of myocardial cell injury, and cardiomyocyte apoptosis were ameliorated in mice by ALDH2 activation or overexpression. In contrast, cardiac dysfunction and cardiomyocyte apoptosis were exacerbated in mice followed ALDH2 inhibition. Moreover, ALDH2 activation or overexpression regulated mitophagy by suppressing the expression of phosphatase and tensin homolog-induced putative kinase 1 (PINK1)/Parkin, by preventing the accumulation of 4-hydroxy-trans-nonenal. Conversely, ALDH2 inhibition promoted the expression of LC3B by increasing 4-hydroxy-trans-2-nonenal accumulation. Consequently, ALDH2 may protect the heart from lipopolysaccharide-induced injury by suppressing PINK1/Parkin-dependent mitophagy.

Semaphorin 3A contributes to sepsis‑induced immunosuppression by impairing CD4+ T cell anergy

Semaphorin 3A (Sema3A), a member of the Sema family of proteins, appears to serve an important role in sepsis and sepsis‑induced immunosuppression and has been regarded as a crucial regulator involved in cellular immune response. However, the role of Sema3A in CD4+ T cell anergy during sepsis remains to be elucidated. In the present study, the cecal ligation and perforation model and lipopolysaccharide (LPS) were used to simulate sepsis and the role of Sema3A in sepsis‑induced CD4+ T cell anergy was investigated in vivo and in vitro. In vivo, the serum concentration of Sema3A was enhanced and exacerbated sepsis‑induced T cell immunosuppression and multiple organ dysfunction syndromes (MODS). Administration of (‑)‑epigallocatechin‑3‑gallate, an inhibitor of Sema3A, markedly improved sepsis‑induced T cell immunosuppression and MODS. In vitro, both lymphoid and myeloid lineages secreted high concentration of Sema3A in LPS‑induced sepsis, especially in the lymphoid lineage. Inhibition of Sema3A alleviated T cell anergy. The NF‑κB signaling pathway was involved in Sema3A‑mediated autocrine loop aggravating T cell immune dysfunction during LPS‑induced sepsis. Inhibiting Sema3A exerted significant improvement of sepsis‑induced immunosuppression and MODS, which was associated with improvement of CD4+ T cells anergy via regulation of the NF‑κB signaling pathway.

From sepsis to acute respiratory distress syndrome (ARDS): emerging preventive strategies based on molecular and genetic researches

A healthy body activates the immune response to target invading pathogens (i.e. viruses, bacteria, fungi, and parasites) and avoid further systemic infection. The activation of immunological mechanisms includes several components of the immune system, such as innate and acquired immunity. Once any component of the immune response to infections is aberrantly altered or dysregulated, resulting in a failure to clear infection, sepsis will develop through a pro-inflammatory immunological mechanism. Furthermore, the severe inflammatory responses induced by sepsis also increase vascular permeability, leading to acute pulmonary edema and resulting in acute respiratory distress syndrome (ARDS). Apparently, potential for improvement exists in the management of the transition from sepsis to ARDS; thus, this article presents an exhaustive review that highlights the previously unrecognized relationship between sepsis and ARDS and suggests a direction for future therapeutic developments, including plasma and genetic pre-diagnostic strategies and interference with proinflammatory signaling.

Nursing Care of Oncology Patients with Sepsis

OBJECTIVES

This article aims to update nurses on the incidence, diagnosis, and treatment of neutropenic sepsis and septic shock.

DATA SOURCES

A search of electronic databases, including PubMed and CINAHL, and e-books was performed, as was a search of clinically focused and point-of-care resources from the National Cancer Institute and UpToDate until December 2020.

CONCLUSION

Neutropenic sepsis and septic shock are oncological emergencies and can be fatal for patients undergoing anticancer treatment. Prompt and targeted treatment based on clinical signs is necessary to minimize further sequela, including morbidity and mortality.

IMPLICATIONS FOR NURSING PRACTICE

The oncology nurse must possess an understanding of the risk factors, presenting signs, and initial management of a neutropenic fever, sepsis, and septic shock. Early identification and initiation of treatments in patients in sepsis and septic shock will allow the oncology nurse to intervene with speed, skill, and confidence while working within the multidisciplinary team to provide the best outcome based on current evidence.

Plasma levels of glucagon but not GLP-1 are elevated in response to inflammation in humans

OBJECTIVE

Glucagon and glucagon-like peptide-1 (GLP-1) originate from the common precursor, proglucagon, and their plasma concentrations have been reported to be increased during inflammatory conditions. Increased blood glucose levels are frequently observed in septic patients, and therefore we hypothesized that glucagon, but not GLP-1, is increased in individuals with inflammation.

DESIGN

Prospective longitudinal cohort study.

MATERIALS AND METHODS

We measured glucagon and GLP-1 in plasma sampled consecutively in three cohorts consisting of patients with infective endocarditis (n = 16), urosepsis (n = 28) and post-operative inflammation following percutaneous aortic valve implantation or thoracic endovascular aortic repair (n = 5). Correlations between C-reactive protein (CRP), a marker of systemic inflammation, and glucagon and GLP-1 concentrations were investigated. Additionally, glucagon and GLP-1 concentrations were measured after a bolus infusion of lipopolysaccharide (LPS, 1 ng/kg) in nine healthy young males.

RESULTS

Glucagon and CRP were positively and significantly correlated (r = 0.27; P = 0.0003), whereas no significant association between GLP-1 and CRP was found (r = 0.08, P = 0.30). LPS infusion resulted in acute systemic inflammation reflected by increased temperature, pulse, tumor necrosis factor-α (TNFα), interleukin-6 (IL-6) and concomitantly increased concentrations of glucagon (P < 0.05) but not GLP-1.

CONCLUSIONS

Systemic inflammation caused by bacterial infections or developed as a non-infected condition is associated with increased plasma concentration of glucagon, but not GLP-1. Hyperglucagonemia may contribute to the impaired glucose control in patients with systemic inflammatory diseases.

Protective Effect of Mitochondria-Targeted Antioxidants against Inflammatory Response to Lipopolysaccharide Challenge: A Review

Lipopolysaccharide (LPS), the major component of the outer membrane of Gram-negative bacteria, is the most abundant proinflammatory agent. Considerable evidence indicates that LPS challenge inescapably causes oxidative stress and mitochondrial dysfunction, leading to cell and tissue damage. Increased mitochondrial reactive oxygen species (mtROS) generation triggered by LPS is known to play a key role in the progression of the inflammatory response. mtROS at excessive levels impair electron transport chain functioning, reduce the mitochondrial membrane potential, and initiate lipid peroxidation and oxidative damage of mitochondrial proteins and mtDNA. Over the past 20 years, a large number of mitochondria-targeted antioxidants (mito-AOX) of different structures that can accumulate inside mitochondria and scavenge free radicals have been synthesized. Their protective role based on the prevention of oxidative stress and the restoration of mitochondrial function has been demonstrated in a variety of common diseases and pathological states. This paper reviews the current data on the beneficial application of different mito-AOX in animal endotoxemia models, in either in vivo or in vitro experiments. The results presented in our review demonstrate the promising potential of approaches based on mito-AOX in the development of new treatment strategies against Gram-negative infections and LPS per se.

Targeting Neuropilin-1 Suppresses the Stability of CD4+ CD25+ Regulatory T Cells via the NF-κB Signaling Pathway in Sepsis

Neuropilin-1 (Nrp-1) contributes to maintaining the stability of CD4⁺ CD25⁺ regulatory T cells (T_regs). We investigated the impact of Nrp-1 on the stability of CD4⁺ CD25⁺ T_regs, and the underlying signaling pathways, in a model of sepsis. Splenic CD4⁺ CD25⁺ T_regs were either treated with anti-Nrp-1, transfected to silence Nrp-1 and inhibitor of NF-κB kinase subunit beta (IKKβ), or administered ammonium pyrrolidine dithiocarbamate (PDTC), followed by recombinant semaphorin 3A (rSema3A), in a simulation of sepsis. After the creation of a sepsis model in mice, anti-Nrp-1 was administered. The expression of the gene encoding forkhead box protein P-3 foxp3-T_reg-specific demethylated region (foxp3-TSDR), the apoptosis rate, the expression of Foxp-3, cytotoxic T-lymphocyte-associated protein-4 (CTLA-4), and transforming growth factor β1 (TGF-β1), interleukin 10 (IL-10) and TGF-β1 secretion, and the NF-κB signaling activity of CD4⁺ CD25⁺ T_regs were determined. Sepsis simulation with or without rSema3A increased the stability of CD4⁺ CD25⁺ T_regs, including an increase in the expression of Foxp-3, CTLA-4, and TGF-β1, decreases in apoptosis and the methylation of foxp3-TSDR, increases in the secretion of TGF-β1 and IL-10, and an increase in the immunosuppressive effect on CD4⁺ T lymphocytes. Silencing of Nrp-1 or anti-Nrp-1 treatment abrogated lipopolysaccharide (LPS) stimulation with or without an rSema3A-mediated effect. Sepsis simulation increased the DNA-binding activity of NF-κB, as well as the ratios of phosphorylated IKKβ (p-IKKβ) to IKKβ and p-P65 to P65 in vitro and vivo Silencing of IKKβ expression or PDTC treatment suppressed the stability of CD4⁺ CD25⁺ T_regs in LPS-induced sepsis. Weakening Nrp-1 reduced the stability of CD4⁺ CD25⁺ T_regs by regulating the NF-κB signaling pathway; thus, Nrp-1 could be a new target for immunoregulation in sepsis.

Cecal Ligation and Puncture

Cecal ligation and puncture (CLP) is referred to as the "gold standard" rodent model for abdominal sepsis. CLP creates a continuously leaking, polymicrobial infectious focus in the abdomen. The abdominal cavity is opened under general anesthesia and analgesia and the cecum is exposed, ligated underneath the ileocecal valve, and punctured with a needle. A small amount of feces is pressed out through the puncture and the cecum is repositioned into the abdomen, which is then closed with single button sutures and tissue glue. CLP severity can be influenced via the length of the ligated cecum as well as the needle size. Within 24 h, animals develop clinical signs of a systemic bacterial infection. Analgesia, wide range antibiotic treatment, and fluid resuscitation should be administered during the acute phase of sepsis to increase the clinical relevance of the CLP model.

Beyond cells: The extracellular circulating 20S proteasomes

Accumulating evidence arising from numerous clinical studies indicate that assembled and functional 20S proteasome complexes circulate freely in plasma. Elevated levels of this core proteolytic complex have been found in the plasma of patients suffering from blood, skin and solid cancers, autoimmune disorders, trauma and sepsis. Moreover, in various diseases, there is a positive correlation between circulating 20S proteasome (c20S) levels and treatment efficacy and survival rates, suggesting the involvement of this under-studied c20S complex in pathophysiology. However, many aspects of this system remain enigmatic, as we still do not know the origin, biological role or mechanisms of extracellular transport and regulation of c20S proteasomes. In this review, we provide an overview of the current understanding of the c20S proteasome system and discuss the remaining gaps in knowledge.

Association of circulating long non-coding RNA HULC expression with disease risk, inflammatory cytokines, biochemical index levels, severity-assessed scores, and mortality of sepsis

Background

The present study aimed to explore the correlation of long non‐coding RNA highly up‐regulating in liver cancer (lncRNA HULC) with disease risk, inflammatory cytokines, biochemical indexes, disease severity, infective features, and 28‐day mortality of sepsis.

Methods

Totally 174 sepsis patients and 100 controls were enrolled. Peripheral blood samples were collected from sepsis patients after diagnosis and from controls at enrollment, respectively, and further for separation of peripheral blood mononuclear cell (PBMC) and serum samples. PBMC samples were for lncRNA HULC detection, and serum samples were for inflammatory cytokine detection.

Results

LncRNA HULC expression was increased in sepsis patients compared with controls. Moreover, lncRNA HULC was positively associated with TNF‐α, IL‐6, IL‐17, intercellular adhesion molecule 1, vascular cell adhesion molecule 1, serum creatinine, white blood cell, and C‐reactive protein in sepsis patients, but not in controls. Furthermore, in sepsis patients, lncRNA HULC expression was positively correlated with acute physiology and chronic health evaluation II score and sequential organ failure assessment score, but not correlated with primary infection sites or primary infection organisms; meanwhile, lncRNA HULC expression was increased in deaths compared with survivors; subsequent receiver operating characteristic curve indicated that lncRNA HULC presented good value in predicting increased 28‐day mortality (AUC: 0.785, 95% CI: 0.713–0.857), and its independent predictive value for mortality was also verified by multivariate analysis.

Conclusion

LncRNA HULC is correlated with higher disease risk, severity, and inflammation and serves as an independent factor for predicting increased mortality, suggesting its potential in promoting accuracy of prognostic prediction for sepsis management.

Effects of Neurological Disorders on Bone Health

Neurological diseases, particularly in the context of aging, have serious impacts on quality of life and can negatively affect bone health. The brain-bone axis is critically important for skeletal metabolism, sensory innervation, and endocrine cross-talk between these organs. This review discusses current evidence for the cellular and molecular mechanisms by which various neurological disease categories, including autoimmune, developmental, dementia-related, movement, neuromuscular, stroke, trauma, and psychological, impart changes in bone homeostasis and mass, as well as fracture risk. Likewise, how bone may affect neurological function is discussed. Gaining a better understanding of brain-bone interactions, particularly in patients with underlying neurological disorders, may lead to development of novel therapies and discovery of shared risk factors, as well as highlight the need for broad, whole-health clinical approaches toward treatment.

Role of Fractalkine in promoting inflammation in sepsis-induced multiple organ dysfunction

OBJECTIVE

Fractalkine, CX3CL1, is involved in the directional movement of chemokine cells, immune response, inflammatory response, tissue repair, and other processes. However, its role in sepsis is not well known.

METHODS

We measured circulating Fractalkine in adult patients with sepsis. Effects of Fractalkine on the survival, inflammation, tissue injury, and bacterial clearance were assessed using the WT or CX3CL^-/- murine model of cecal ligation and puncture (CLP)-induced sepsis.

RESULTS

Serum Fractalkine concentrations were significantly elevated in adult patients with sepsis compared to healthy adults. Increased Fractalkine correlated positively with the number of blood leukocytes and the level of inflammatory cytokines, including IL-6, IL-1β, IL-17A, IFN-γ, and TNF-α, and correlated negatively with IL-10 in clinical sepsis. Recombinant Fractalkine impaired survival whereas Fractalkine gene knockout or anti-Fractalkine antibody improved survival in the murine model of CLP-induced sepsis. Fractalkine administration increased inflammatory response, evident by higher levels of cytokines (TNF-α, IL-1β, IL-17A, IFN-γ, and IL-6 but not IL-10), and tissue damage (lung, liver, and kidney) in CLP-induced sepsis. Fractalkine reduced bacterial clearance in CLP-induced polymicrobial sepsis by reducing macrophage or neutrophil phagocytosis and intracellular elimination of E. coli.

CONCLUSIONS

Fractalkine aggravates sepsis by increasing inflammation and decreasing bacterial clearance, and is a potential tool for anti-sepsis therapy.

Innate immune receptors in platelets and platelet-leukocyte interactions

Platelets are chief cells in hemostasis. Apart from their hemostatic roles, platelets are major inflammatory effector cells that can influence both innate and adaptive immune responses. Activated platelets have thromboinflammatory functions linking hemostatic and immune responses in several physiological and pathological conditions. Among many ways in which platelets exert these functions, platelet expression of pattern recognition receptors (PRRs), including TLR, Nod-like receptor, and C-type lectin receptor families, plays major roles in sensing and responding to pathogen-associated or damage-associated molecular patterns (PAMPs and DAMPs, respectively). In this review, an increasing body of evidence is compiled showing the participation of platelet innate immune receptors, including PRRs, in infectious diseases, sterile inflammation, and cancer. How platelet recognition of endogenous DAMPs participates in sterile inflammatory diseases and thrombosis is discussed. In addition, platelet recognition of both PAMPs and DAMPs initiates platelet-mediated inflammation and vascular thrombosis in infectious diseases, including viral, bacterial, and parasite infections. The study also focuses on the involvement of innate immune receptors in platelet activation during cancer, and their contribution to tumor microenvironment development and metastasis. Finally, how innate immune receptors participate in platelet communication with leukocytes, modulating leukocyte-mediated inflammation and immune functions, is highlighted. These cell communication processes, including platelet-induced release of neutrophil extracellular traps, platelet Ag presentation to T-cells and platelet modulation of monocyte cytokine secretion are discussed in the context of infectious and sterile diseases of major concern in human health, including cardiovascular diseases, dengue, HIV infection, sepsis, and cancer.

Lipoic Acid and Fish Oil Combination Potentiates Neuroinflammation and Oxidative Stress Regulation and Prevents Cognitive Decline of Rats After Sepsis

Sepsis causes organ dysfunction due to an infection, and it may impact the central nervous system. Neuroinflammation and oxidative stress are related to brain dysfunction after sepsis. Both processes affect microglia activation, neurotrophin production, and long-term cognition. Fish oil (FO) is an anti-inflammatory compound, and lipoic acid (LA) is a universal antioxidant substance. They exert neuroprotective roles when administered alone. We aimed at determining the effect of FO+LA combination on microglia activation and brain dysfunction after sepsis. Microglia cells from neonatal pups were co-treated with lipopolysaccharide (LPS) and FO or LA, alone or combined, for 24 h. Cytokine levels were measured. Wistar rats were subjected to sepsis by cecal ligation and perforation (CLP) and treated orally with FO, LA, or FO+LA. At 24 h after surgery, the hippocampus, prefrontal cortex, and total cortex were obtained and assayed for levels of cytokines, myeloperoxidase (MPO) activity, protein carbonyls, superoxide dismutase (SOD), and catalase (CAT) activity. At 10 days after surgery, brain-derived neurotrophic factor (BDNF) levels were determined and behavioral tests were performed. The combination diminished in vitro levels of pro-inflammatory cytokines. The combination reduced TNF-α in the cortex, IL-1β in the prefrontal cortex, as well as MPO activity, and decreased protein carbonyls formation in all structures. The combination enhanced catalase activity in the prefrontal cortex and hippocampus, elevated BDNF levels in all structures, and prevented behavioral impairment. In summary, the combination was effective in preventing cognitive damage by reducing neuroinflammation and oxidative stress and increasing BDNF levels.

Zebrafish GSDMEb Cleavage-Gated Pyroptosis Drives Septic Acute Kidney Injury In Vivo

The bacteria LPS is one of the leading endotoxins responsible for sepsis; its sensing pathway-induced pyroptosis plays an important role in innate immunity. However, excessive pyroptosis might cause immunological diseases, even multiple organ failure and death by undefined mechanisms. Given that the development of acute kidney injury (AKI) in patients with sepsis causes significant morbidity and mortality, the mechanism of pyroptosis in regulating septic AKI remains unknown. In this study, we establish a zebrafish crispant in vivo analysis model and reveal that both caspy2 and gasdermin Eb (GSDMEb) contribute to lethal LPS-induced septic shock. Meanwhile, the in vitro analysis reveals that caspy2 activation can specifically cleave GSDMEb to release its N terminus to mediate pyroptosis, which functions as GSDMD in mammals. Interestingly, we establish an in vivo propidium iodide-staining method and reveal that the caspy2-GSDMEb signaling cascade is essential for enhancing renal tubular damage during lethal LPS-induced septic shock, whereas administration of the zebrafish-specific GSDMEb-derived peptide inhibitor Ac-FEID-CMK can attenuate mortality and septic AKI in vivo. Moreover, we confirm that either caspase-11 or GSDMD deficiency decreases both inflammatory cytokines and kidney dysfunction enzyme release and prolongs survival in a murine model of septic shock. Taken together, these findings demonstrate an evolutionary executor for pyroptosis in zebrafish and reveal that the pyroptosis of renal tubular cells is a major cause of septic AKI, and also provide an ideal in vivo screening model for potential antisepsis therapeutic strategies.

Combination of Glutamine and Ulinastatin Treatments Greatly Improves Sepsis Outcomes

Background

Sepsis is one of the most dangerous syndromes, has extremely high mortality, and is caused by the body’s extreme responses to an infection. The pathogenesis of sepsis is very complex and remains largely unknown and thus the treatments for sepsis are limited. Here, we evaluated the treatment results of two potential drugs, glutamine and ulinastatin, on sepsis.

Methods

CLP rat model was used to study sepsis. Gastrostomy was performed to deliver the drugs. Flow cytometry was employed to measure CD4 and CD8 levels. May–Grünwald–Giemsa staining was used to count the numbers of monocytes and neutrophils in the blood. ELISA assay was performed to assess the levels of PCT, IL-6, TNFα, and IL-1β.

Results

Sepsis was successfully induced with the standard CLP rat model. Both glutamine and ulinastatin treatments greatly improved the outcomes of sepsis, but the combination of both treatments had the maximum therapeutic effect. Mechanistically, PCT, IL-6, TNFα, and IL-1β levels were significantly diminished following glutamine and ulinastatin treatments, suggesting an inhibition of inflammatory responses. Further, CD4 and CD4/CD8 ratio, and the numbers of monocytes and neutrophils were greatly up-regulated by glutamine and ulinastatin, indicating an enhanced immunity.

Conclusion

Glutamine and ulinastatin treatments largely mitigate sepsis shock by suppressing the inflammatory responses of the body and strengthening the immune system. Combination of these two drugs could serve as a potential treatment for sepsis.

The protective effects of Thalictrum minus L. on lipopolysaccharide-induced acute lung injury

ETHNOPHARMACOLOGICAL RELEVANCE

Thalictrum minus L., a Mongolian folk medicinal plant, was applied for the treatment of bacterial and fungal infection, tuberculosis and lung inflammation.

AIM OF THE STUDY

The present work aims to elucidate the protective effects of Thalictrum minus L.(TML) against lipopolysaccharide (LPS)-induced acute lung injury and the underlying mechanisms.

METHODS

The mice model of acute lung injury was induced by LPS via endotracheal drip, and TML (10, 20, 40 mg/kg) were administered orally 1 h prior to LPS. The efficacy and molecular mechanisms in the presence or absence of TML were investigated.

RESULTS

We demonstrated that treatment with TML aqueous extract protected the mice from acute lung injury induced by LPS administration. TML significantly inhibited weight loss in mice, decreased the lung wet to dry weight (W/D) ratios and attenuated lung histopathological changes, such as infiltration of inflammatory cells and coagulation, pulmonary edema. Furthermore, we found that TML markedly reduced the LPS-induced inflammatory cytokines including tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), decreased nitric oxide (NO), and increased superoxide dismutase (SOD) in bronchoalveolar lavage fluid (BALF), and effectively ameliorated LPS-induced increased total protein, leukocyte and macrophages in BALF. In addition, TML pronouncedly suppressed the activation of the MAPKs p38-NLRP3/caspase-1 and COX2, increased the expression of p-AMPK-Nrf2, and suppressed the expression of KEAP, apoptotic-related protein as well as autophagy.

CONCLUSIONS

These results suggested that TML ameliorated LPS-induced acute lung injury by inhibiting the release of inflammatory cytokines and reducing oxidative damage associated with the MAPKs p38-NLRP3/caspase-1 and COX2 signaling pathways, AMPK-Nrf2/KEAP signaling pathways, as well as apoptosis and autophagy.

Effect of magnesium supplementation on lactate clearance in critically ill patients with severe sepsis: a randomized clinical trial

OBJECTIVES

In this study, changes in lactate clearance following magnesium supplementation were evaluated in critically ill patients with severe sepsis.

METHODS

Fifty-eight patients with severe sepsis were randomly assigned to receive either magnesium (n = 30) or placebo (n = 28). Patients in the magnesium group received intravenous magnesium sulfate to maintain serum magnesium level around 3 mg/dL for 3 days. The placebo group received the same volume of normal saline. Change in lactate clearance was considered primary outcome of the study.

RESULTS

Mean increase in the lactate clearance in the magnesium group was significantly higher than the placebo group on day 2 (27.53% vs. 23.79% respectively, p < 0.001) and day 3 (49.83% vs. 37.02% respectively, p < 0.001). Time to lactate clearance was also significantly shorter in the magnesium group than the placebo group (47.28 ± 20.59 vs. 61.20 ± 24.31 h respectively, p = 0.03). Sepsis-related mortality was not significantly different but median length of ICU stay was significantly shorter in the magnesium group than the placebo group (8 vs. 15 days respectively, p < 0.01).

CONCLUSIONS

Magnesium supplementation increased lactate clearance in critically ill patients with severe sepsis. Optimizing serum magnesium level near the upper limit of the normal range may improve severe sepsis outcomes.

lncRNA MALAT1 Accelerates Skeletal Muscle Cell Apoptosis and Inflammatory Response in Sepsis by Decreasing BRCA1 Expression by Recruiting EZH2

Sepsis is a serious and elusive syndrome caused by infection, which is accompanied by a high mortality worldwide. Recent evidence has documented the regulatory role of long non-coding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) during the inflammatory process, the effects of which in the development of sepsis have become the focus of the current study. An in vivo mouse model and in vitro cell model of sepsis induced by lipopolysaccharide (LPS) were developed. High expression of lncRNA MALAT1 along with low expression of breast cancer susceptibility gene 1 (BRCA1) were identified in septic mice and human skeletal muscle cells of sepsis. Then, lncRNA MALAT1 expression was altered in vivo and in vitro to examine serum levels of inflammatory factors, as well as skeletal muscle cell apoptosis. lncRNA MALAT1 was noted to regulate the expression and export from the nucleus of BRCA1 by recruiting zeste homolog 2 (EZH2) in skeletal muscle cells of sepsis. Silencing lncRNA MALAT1 resulted in reduced serum levels of interleukin (IL)-6, IL-8, and tumor necrosis factor alpha (TNF-α), neutrophil migration, skeletal muscle cell apoptosis, and AKT-1 phosphorylation. Taken together, lncRNA MALAT1 interacting with EZH2 stimulated AKT-1 phosphorylation and decreased BRCA1 expression, consequently aggravating the progression of sepsis, highlighting a promising therapeutic option for sepsis.

Eicosanoids derived from cytochrome P450 pathway of arachidonic acid and inflammatory shock

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. Septic shock, the most common form of vasodilatory shock, is a subset of sepsis in which circulatory and cellular/metabolic abnormalities are severe enough to increase mortality. Inflammatory shock constitutes the hallmark of sepsis, but also a final common pathway of any form of severe long-term tissue hypoperfusion. The pathogenesis of inflammatory shock seems to be due to circulating substances released by pathogens (e.g., bacterial endotoxins) and host immuno-inflammatory responses (e.g., changes in the production of histamine, bradykinin, serotonin, nitric oxide [NO], reactive nitrogen and oxygen species, and arachidonic acid [AA]-derived eicosanoids mainly through NO synthase, cyclooxygenase, and cytochrome P450 [CYP] pathways, and proinflammatory cytokine formation). Therefore, refractory hypotension to vasoconstrictors with end-organ hypoperfusion is a life threatening feature of inflammatory shock. This review summarizes the current knowledge regarding the role of eicosanoids derived from CYP pathway of AA in animal models of inflammatory shock syndromes with an emphasis on septic shock in addition to potential therapeutic strategies targeting specific CYP isoforms responsible for proinflammatory/anti-inflammatory mediator production.