Sepsis: A Review of Advances in Management

CircPTK2-miR-181c-5p-HMGB1: a new regulatory pathway for microglia activation and hippocampal neuronal apoptosis induced by sepsis

BACKGROUND

Circular RNA hsa_circ_0008305 (circPTK2), miR-181c-5p and High mobility group box-1 (HMGB1) had a targeted regulatory relationship through bioinformatics analysis. This study explained the effects of these genes in microglia and sepsis mice.

METHODS

Lipopolysaccharide (LPS) or Cecal Ligation and Puncture (CLP) was used to induce inflammation cell model or sepsis mouse model, as needed. Gene levels were measured by enzyme linked immunosorbent assay (ELISA), quantitative real-time PCR or Western blot, as required. Apoptosis was detected by TUNEL assay, and RNase R was used to test the stability of circPTK2. Targeting relationships between genes were analyzed using bioinformatics analysis and dual luciferase assay. Morris water maze test and mitochondrial membrane potential (MMP) detection were conducted to analyze the effects of genes on cognitive dysfunction of mice.

RESULTS

Lipopolysaccharide induction triggered the release of pro-inflammatory cytokines, the upregulation of HMGB1 and circPTK2, and the downregulation of miR-181c-5p in microglia. Overexpression of HMGB1 enhanced the effect of LPS, while silencing HMGB1 partially counteracted the effect of LPS. Moreover, miR-181c-5p was a target of circPTK2 and bound to HMGB1. MiR-181c-5p mimic partially reversed the functions of LPS and HMGB1 overexpression, reduced the levels of TNF-α, IL-1β, and HMGB1, and inhibited apoptosis. CircPTK2 knockdown had the same effect as miR-181c-5p up-regulation. In vivo, sicircPTK2 improved cognitive function, restored MMP level, inhibited apoptosis, reduced the levels of inflammatory factors and apoptotic factors, and increased the survival rate of CLP-induced mice.

CONCLUSION

Our research reveals that circPTK2 regulates microglia activation and hippocampal neuronal apoptosis induced by sepsis via miR-181c-5p-HMGB1 signaling.

Macrophage-preferable delivery of the leucine-rich repeat domain of NLRX1 ameliorates lethal sepsis by regulating NF-κB and inflammasome signaling activation

Sepsis is an acute systemic inflammatory disease triggered by bacterial infection leading organ dysfunctions that macrophages are responsible for major triggering of systemic inflammation. Treatment options are limited to antibiotics and drugs to manage the symptoms of sepsis, but there are currently no molecular-targeted therapies. Here, we identified a novel macrophage-preferable delivery peptide, C10, which we conjugated to truncated domains of NLRX1 (leucine-rich repeat region (LRR), and nucleotide binding domain (NBD)) to obtain C10-LRR and C10-NBD. Leucine rich amino acid of C10 enables macrophage preferable moieties that efficiently deliver a cargo protein into macrophages in vitro and in vivo. C10-LRR but not C10-NBD significantly improved survival in an LPS-mediated lethal endotoxemia sepsis model. C10-LRR efficiently inhibited IL-6 production in peritoneal macrophages via prevention of IκB degradation and p65 phosphorylation. In addition, C10-LRR negatively regulated IL-1β production by preventing caspase-1 activation with a sustained mitochondrial MAVS level. Finally, co-treatment with anti-TNFα antibody and C10-LRR had a synergistic effect in an LPS-induced sepsis model. Collectively, these findings indicate that C10-LRR could be an effective therapeutic agent to treat systemic inflammation in sepsis by regulating both NF-κB and inflammasome signaling activation.

Association of plasma level of high-mobility group box-1 with necroptosis and sepsis outcomes

The role of high-mobility group box-1 (HMGB1) in outcome prediction in sepsis is controversial. Furthermore, its association with necroptosis, a programmed cell necrosis mechanism, is still unclear. The purpose of this study is to identify the association between the plasma levels of HMGB1 and the severity and clinical outcomes of sepsis, and to examine the correlation between HMGB1 and key executors of necroptosis including receptor-interacting kinase 3 (RIPK3) and mixed lineage kinase domain-like- (MLKL) proteins. Plasma HMGB1, RIPK3, and MLKL levels were measured with the enzyme-linked immunosorbent assay from the derivation cohort of 188 prospectively enrolled, critically-ill patients between April 2014 and December 2016, and from the validation cohort of 77 patients with sepsis between January 2017 and January 2019. In the derivation cohort, the plasma HMGB1 levels of the control (n = 46, 24.5%), sepsis (n = 58, 30.9%), and septic shock (n = 84, 44.7%) groups were significantly increased (P < 0.001). A difference in mortality between high (≥ 5.9 ng/mL) and low (< 5.9 ng/mL) HMGB1 levels was observed up to 90 days (Log-rank test, P = 0.009). There were positive linear correlations of plasma HMGB1 with RIPK3 (R² = 0.61, P < 0.001) and MLKL (R² = 0.7890, P < 0.001). The difference in mortality and correlation of HMGB1 levels with RIPK3 and MLKL were confirmed in the validation cohort. Plasma levels of HMGB1 were associated with the severity and mortality attributed to sepsis. They were correlated with RIPK3 and MLKL, thus suggesting an association of HMGB1 with necroptosis.

Vitamin D and Its Potential Benefit for the COVID-19 Pandemic

Vitamin D is known not only for its importance for bone health but also for its biologic activities on many other organ systems. This is due to the presence of the vitamin D receptor in various types of cells and tissues, including the skin, skeletal muscle, adipose tissue, endocrine pancreas, immune cells, and blood vessels. Experimental studies have shown that vitamin D exerts several actions that are thought to be protective against coronavirus disease (COVID-19) infectivity and severity. These include the immunomodulatory effects on the innate and adaptive immune systems, the regulatory effects on the renin-angiotensin-aldosterone-system in the kidneys and the lungs, and the protective effects against endothelial dysfunction and thrombosis. Prior to the COVID-19 pandemic, studies have shown that vitamin D supplementation is beneficial in protecting against risk of acquiring acute respiratory viral infection and may improve outcomes in sepsis and critically ill patients. There are a growing number of data connecting COVID-19 infectivity and severity with vitamin D status, suggesting a potential benefit of vitamin D supplementation for primary prevention or as an adjunctive treatment of COVID-19. Although the results from most ongoing randomized clinical trials aiming to prove the benefit of vitamin D supplementation for these purposes are still pending, there is no downside to increasing vitamin D intake and having sensible sunlight exposure to maintain serum 25-hydroxyvitamin D at a level of least 30 ng/mL (75 nmol/L) and preferably 40 to 60 ng/mL (100-150 nmol/L) to minimize the risk of COVID-19 infection and its severity.

The potential of FT-IR spectroscopy for improving healthcare in sepsis - An animal model study

Fourier Transform-Infrared (FT-IR) absorption spectroscopy has been used to investigate pathophysiological changes caused by sepsis. Sepsis has been defined as a potentially fatal organic dysfunction caused by a dysregulated host response to infection and can lead a patient to risk of death. This study used samples consisting of the blood plasma of mice which were induced to sepsis state, compared to a healthy group using FT-IR associated with attenuated total reflectance (ATR) spectroscopy. For statistical analysis, principal components analysis (PCA) and linear discriminant analysis (LDA) were applied, independently, to the second derivative spectra of both the fingerprint (900-1800 cm^-1) and the high wavenumber (2800-3100 cm^-1) regions. The technique efficiently differentiated the blood plasma of the two groups, sepsis and healthy mice, the analysis indicating that fatty acids and lipids in the blood samples could be an important biomarker of sepsis.

Skin and sepsis: contribution of dermatology to a rapid diagnosis

In patients who develop sepsis, whether due to primary, secondary or metastatic lesions, the skin is frequently affected. However, there are unresolved aspects regarding the general clinical manifestations in the skin or the prognosis and/or therapeutic implications. The main challenge in the approach to sepsis is its early diagnosis and management. In this review, we address the sepsis-skin relationship and the potential impact of early dermatological intervention on the septic patient through ten basic questions. We found little evidence of the participation of the dermatologist in sepsis alert programs. There are early skin changes that may alert clinicians on a possible sepsis, such as skin mottling or variations in acral skin temperature. In addition, the skin is an accessible and highly cost-effective tissue for etiological studies of some forms of sepsis (e.g., meningococcal purpura) and its involvement defines the prognosis of certain patients (e.g., infective endocarditis).

Using the Cecal Ligation and Puncture Model of Sepsis to Induce Rats to Multiple Organ Dysfunction

Sepsis is a dysregulated hyperinflammatory disease caused by infection. Sepsis leads to multiple organ dysfunction syndrome (MODS), which is associated with high rates of mortality. The cecal ligation and puncture (CLP) model has been widely used in animals and has become the gold-standard method of replicating features of sepsis in humans. Despite several studies and modified CLP protocols, there are still open questions regarding the multifactorial determinants of its reproducibility and medical significance. In our protocol, which is also aimed at mimicking the sepsis observed in clinical practice, male Wistar rats are submitted to CLP with adequate fluid resuscitation (0.15 M NaCl, 25 ml/kg BW i.p.) immediately after surgery. At 6 h after CLP, additional fluid therapy (0.15 M NaCl, 25 ml/kg BW s.c.) and antibiotic therapy with imipenem-cilastatin (single dose of 14 mg/kg BW s.c.) are administered. The timing of the fluid and antibiotic therapy correspond to the initial care given when patients are admitted to the intensive care unit. This model of sepsis provides a useful platform for simulating human sepsis and could lay the groundwork for the development of new treatments.

OLFM4 polymorphisms predict septic shock survival after major surgery

BACKGROUND

Higher expression of olfactomedin-4 (OLFM4), a gene regulated by nuclear factor-kappa B (NF-κB), has been related to a higher risk of organ failure and death in patients with septic shock. We aimed to evaluate the association between OLFM4 single nucleotide polymorphisms (SNPs) and septic shock-related death in 175 patients who underwent major surgery, as well as its performance in predicting mortality.

MATERIALS AND METHODS

We carried out a retrospective study. A total of seven OLFM4 SNPs were genotyped by Agena Bioscience's MassARRAY platform. Statistical analysis was performed by Kaplan-Meier and Cox regression tests. The diagnostic performance for predicting septic shock-related death was evaluated by the area under the receiver-operating characteristic (AUROC) curve.

RESULTS

Patients with rs17552047 A allele and rs1891944 TT genotype had higher survival than patients with rs17552047 G allele (P-value = .024) and patients with rs1891944 CC/CT genotype (P-value = .038). However, only rs17552047 was associated with a lower risk of death under an additive inheritance model (adjusted hazard ratio [aHR] = 0.44, 95% CI = 0.27-0.71). The multivariate model with the most significant clinical variables (lactate, chronic kidney disease, peritonitis, heart disease and elective surgery) showed an AUROC of 0.776 for predicting septic shock-related death. When we added the OLFM4 rs17552047 SNP to the previous model, the AUROC was 0.811 and was close to reaching significant differences with the previous model (P-value = .065).

CONCLUSION

OLFM4 rs17552047 A allele predicts septic shock survival in patients who underwent major surgery. Furthermore, rs17552047, together with clinical variables, could be useful to predict the outcome of septic shock.

Therapeutic Efficacy of Excretory-Secretory Products of Trichinella spiralis Adult Worms on Sepsis-Induced Acute Lung Injury in a Mouse Model

Acute lung injury (ALI) is a common complication of systemic inflammation or sepsis with high morbidity and mortality. Although many studies have confirmed that helminth-derived proteins had strong immunomodulatory functions and could be used to treat inflammatory diseases, there is no report on the therapeutic effect of excretory-secretory products of Trichinella spiralis adult worms (Ts-AES) on sepsis-induced ALI. In this study, the therapeutic efficacy of Ts-AES on sepsis-induced ALI and the underlying immunological mechanism and the signaling pathway were investigated. The results indicated that after being treated with Ts-AES, the survival rate of mice with CLP-induced sepsis was significantly increased to 50% for 72 hours after CLP surgery compared to PBS control group with all mice died. The sepsis-induced ALI was largely mitigated characterized by reduced inflammation cell infiltration and pathological changes in lung tissue, with decreased lung injury scores and lung wet/dry weight ratio. The therapeutic efficacy of Ts-AES is associated with stimulated Tregs response with increased regulatory cytokines IL-10 and TGF-β and downregulated pro-inflammatory cytokines (TNF-α, IL-6, IL-1β). The expression of HMGB1, TLR2 and MyD88 in lung tissue was inhibited after treatment of Ts-AES. Our results demonstrated that Ts-AES play an important role in immunomodulation and confer a therapeutic effect on sepsis-induced ALI through inhibiting pro-inflammatory cytokines. The activation of Tregs and increased level of regulatory cytokines IL-10 and TGF-β are possibly involved in the immunomodulatory functions of Ts-AES through HMGB1/TLR2/MyD88 signal pathway. The findings suggest Ts-AES is a potential therapeutic agent for prevention and treatment of sepsis-induced ALI and other inflammatory diseases.

Efficacy of alanyl glutamine in nutritional support therapy for patients with sepsis: A protocol for systematic review and meta-analysis

BACKGROUND

Sepsis is a systemic inflammatory response caused by infection, which is a common complication after severe infection, trauma, shock, and surgery, and is also an important factor in inducing septic shock and multiple organ dysfunction syndrome (MODS), and has become one of the important causes of death in critically ill patients. Septic patients with gastrointestinal transport function weakened, are prone to malnutrition, resulting in decreased immune function, thereby affecting the therapeutic effect. Clinical practice shows that the nutritional metabolism and immune response of patients with sepsis can be effectively improved by giving alanyl glutamine nutritional support treatment, but there is no evidence of evidence-based medicine. The study carried out in this protocol aims to evaluate the effectiveness of alanyl glutamine in nutritional support therapy for patients with sepsis.

METHODS

The Cochrane Library, PubMed, Embase, Web of Science, WHO International Clinical Trials Registry Platform, CNKI, CBM, VIP, and Wanfang databases were searched by computer, to retrieve all randomized controlled trials (RCTs) on nutritional support for the treatment of sepsis with alanyl glutamine from the date of database establishment to December 2020. Two researchers independently selected the study, extracted and managed the data. RevMan5.3 software was used to analyze the included literature.

RESULTS

This study observed the changes of serum albumin (ALB), prealbumin (PAB), hemoglobin (Hb), C-reactive protein (CRP), immunoglobulin (IgG, IgA, and IgM), APACHE II score before and after treatment to evaluate the efficacy of alanyl glutamine in nutritional support therapy for patients with sepsis.

CONCLUSION

This study will provide reliable evidence for the application of alanyl glutamine in nutritional support therapy for patients with sepsis.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/VRZPJ.

Immune Resolution Dilemma: Host Antimicrobial Factor S100A8/A9 Modulates Inflammatory Collateral Tissue Damage During Disseminated Fungal Peritonitis

Intra-abdominal infection (peritonitis) is a leading cause of severe disease in surgical intensive care units, as over 70% of patients diagnosed with peritonitis develop septic shock. A critical role of the immune system is to return to homeostasis after combating infection. S100A8/A9 (calprotectin) is an antimicrobial and pro-inflammatory protein complex used as a biomarker for diagnosis of numerous inflammatory disorders. Here we describe the role of S100A8/A9 in inflammatory collateral tissue damage (ICTD). Using a mouse model of disseminated intra-abdominal candidiasis (IAC) in wild-type and S100A8/A9-deficient mice in the presence or absence of S100A9 inhibitor paquinimod, the role of S100A8/A9 during ICTD and fungal clearance were investigated. S100A8/A9-deficient mice developed less ICTD than wild-type mice. Restoration of S100A8/A9 in knockout mice by injection of recombinant protein resulted in increased ICTD and fungal clearance comparable to wild-type levels. Treatment with paquinimod abolished ICTD and S100A9-deficient mice showed increased survival compared to wild-type littermates. The data indicates that S100A8/A9 controls ICTD levels and antimicrobial activity during IAC and that targeting of S100A8/A9 could serve as promising adjunct therapy against this challenging disease.

EZH2 inhibitor GSK343 inhibits sepsis-induced intestinal disorders

Enhancer of zeste homolog 2 (EZH2) is positively associated with poor clinical outcomes in a number of aggressive tumors. Recent studies have demonstrated that inhibition of EZH2 also suppressed the inflammatory response during sepsis. The present study aimed to investigate whether an inhibitor of EZH2, GSK343, could protect the intestine against sepsis-induced injury in vivo. Mice underwent cecal ligation and perforation (CLP) to induce sepsis and were assigned into three groups: Sham, CLP and CLP + GSK343. For GSK343 treatment, the septic mice were intravenously injected with GSK343 at 6 h post-CLP. The results indicated that EZH2 was highly expressed while tight junction (TJ) proteins ZO-1, occludin and claudin-1 expression was reduced in the intestinal tissue of mice subjected to CLP compared with the sham group. CLP operation also caused intestinal pathological injury and the production of inflammatory cytokines including TNF-α, IL-1β and IL-6 in both serum and intestinal tissues. Meanwhile, CLP induced cell apoptosis of intestinal tissue based on the increased number of apoptotic cells, reduced expression of Bcl-2 and higher expression of caspase-3 and Bax. However, the presence of GSK343 partially rescued intestinal pathological injury, reduced the level of inflammatory cytokines, repressed cell apoptosis and promoted TJ protein expression. Finally, the decreased number of Paneth cells caused by CLP operation was reversed by GSK343 treatment. In conclusion, the results of the present study demonstrated that GSK343 could protect the intestine against sepsis-induced injury in vivo. Inhibition of EZH2 may provide a therapeutic approach for intestinal dysfunction during sepsis.

Multifunctional lipid-based nanocarriers with antibacterial and anti-inflammatory activities for treating MRSA bacteremia in mice

Background

Bacteremia-induced sepsis is a leading cause of mortality in intensive care units. To control a bacterial infection, an immune response is required, but this response might contribute to organ failure. Kidneys are one of the main organs affected by bacteremia. Combination therapies with antibacterial and anti-inflammatory effects may be beneficial in treating bacteremia. This study aimed to develop nanostructured lipid carriers (NLCs) loaded with ciprofloxacin and rolipram that exert a combination of anti-methicillin-resistant Staphylococcus aureus (MRSA) and anti-inflammatory effects. Retinol was incorporated into the nanoparticles to transport retinol-binding protein 4 (RBP4) to the kidneys, which abundantly express RBP receptors. The NLCs were fabricated by high-shear homogenization and sonication, and neutrophils were used as a model to assess their anti-inflammatory effects. Mice were injected with MRSA to establish a model of bacteremia with organ injury.

Results

The mean nanoparticle size and zeta potential of the NLCs were 171 nm and − 39 mV, respectively. Ciprofloxacin (0.05%, w/v) and rolipram (0.02%) achieved encapsulation percentages of 88% and 96%, respectively, in the nanosystems. The minimum bactericidal concentration of free ciprofloxacin against MRSA increased from 1.95 to 15.63 µg/ml when combined with rolipram, indicating a possible drug-drug interaction that reduced the antibacterial effect. Nanoparticle inclusion promoted the anti-MRSA activity of ciprofloxacin according to time-kill curves. The NLCs were found to be largely internalized into neutrophils and exhibited superior superoxide anion inhibition than free drugs. Retinol incorporation into the nanocarriers facilitated their efficient targeting to the kidneys. The NLCs significantly mitigated MRSA burden and elastase distribution in the organs of MRSA-infected animals, and the greatest inhibition was observed in the kidneys. Bacterial clearance and neutrophil infiltration suppression attenuated the bacteremia-induced cytokine overexpression, leading to an improvement in the survival rate from 22% to 67%.

Conclusions

The dual role of our NLCs endowed them with greater efficacy in treating MRSA bacteremia than that of free drugs.

Association of Plasma Levels of FAS Ligand with Severity and Outcome of Sepsis

INTRODUCTION

Levels of the apoptosis regulator Fas ligand (FasL) are associated with severity of sepsis, but its association with the mortality of sepsis and necroptosis, a regulated cell death mechanism, is not yet clear. We aimed to assess the association of FasL level with outcomes of sepsis and receptor interacting protein kinase-3 (RIPK3), an essential necroptosis mediator, for determining the relationship between FasL and necroptosis.

METHODS

Plasma FasL and RIPK3 levels were measured by ELISA from prospectively enrolled critically-ill adult patients. The best cut-off level of FasL for 28-day mortality prediction was determined by Youden's index. The association between plasma levels of FasL and RIPK3 was assessed by a linear regression method.

RESULTS

Among 188 patients, 58 (30.9%) were diagnosed with sepsis and 84 (44.7%) with septic shock, respectively. Plasma levels of FasL increased in the group order of control, sepsis, and septic shock groups (P for trend < 0.001). For 142 patients with sepsis, organ dysfunction and septic shock were more prevalent in the group with plasma FasL levels that were higher than the best cut-off level. A significant difference in mortality between high and low FasL patients was observed up to 90 days (Log-rank P = 0.013). FasL levels did not significantly change over day 3 and day 7. FasL levels were not correlated with those of RIPK3.

CONCLUSIONS

The plasma level of FasL was associated with severity of sepsis and was predictive of mortality. However, it was not correlated with RIPK3 level.

MAR1 suppresses inflammatory response in LPS-induced RAW 264.7 macrophages and human primary peripheral blood mononuclear cells via the SIRT1/PGC-1α/PPAR-γ pathway

Background

Sepsis is a complex syndrome characterized by a dysregulated inflammatory response to systemic infection and leads to shock, multiple organ failure and death especially if not recognized early and treated promptly. Previous studies have suggested Maresin 1 (MAR1) can alleviate systemic inflammation in sepsis, but its mechanism has not been clarified.

Methods

RAW 264.7 cells and human primary peripheral blood mononuclear cells (hPBMCs) were pretreated with LPS and MAR1. The mRNA expression and supernatant levels of pro-inflammatory cytokines, tumor necrosis factor (TNF-α), interleukin (IL)-1β and IL-6 were evaluated by RT-qPCR and ELISA, respectively. The expression levels of Sirtuin 1 (SIRT1), peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), and Peroxisome proliferator-activated receptor gamma (PPAR-γ) were determined by RT-qPCR and Western blot analysis, respectively.

Results

Our results show that LPS-induced inflammation increased the expression and secretion of proinflammatory cytokines TNF-α, IL-1β and IL-6 and induced suppression of SIRT1, PGC-1α, and PPAR-γ expression, which could be reversed by MAR1. And the effect of MAR1 was eliminated by repression of SIRT1/PPAR-γ and enhanced by PGC-1α overexpression.

Conclusions

MAR1 suppressed inflammatory response in LPS-induced RAW 264.7 macrophages and hPBMCs via the SIRT1/PGC-1α/PPAR-γ pathway.

LncRNA NEAT1 acts as a key regulator of cell apoptosis and inflammatory response by the miR-944/TRIM37 axis in acute lung injury

Acute lung injury (ALI), a common complication of sepsis, is characterized by the impairment and injury of pulmonary function. The nuclear factor kappa-B (NF-κB) pathway is activated in ALI. Tripartite motif-containing 37 (TRIM37) can activate the NF-κB pathway and is closely associated with inflammation. The purpose of our study is to reveal the role of TRIM37 in ALI. The present study revealed that TRIM37 presented high levels in lung tissues of ALI mice, and knockdown of TRIM37 alleviated lipopolysaccharide (LPS)-induced lung injury, inflammatory response, and cell apoptosis in vivo. In addition, knockdown of TRIM37 inhibited the inflammatory response, and cell apoptosis of LPS-treated WI-38 cells. Mechanistically, miR-944 was identified to bind with and negatively regulate TRIM37. Furthermore, NEAT1 was indicated to act as a competitive endogenous RNA to promote TRIM37 expression by sequestering miR-944. Detailly, NEAT1 bound with miR-944, negatively modulated miR-944 expression, and positively modulated TRIM37 expression. The rescue assays suggested that overexpression of TRIM37 rescued the influence of NEAT1 knockdown on cell apoptosis and inflammatory response. Overall, NEAT1 facilitated cell apoptosis and inflammatory response of WI-38 cells by the miR-944/TRIM37 axis in sepsis-induced ALI, implying that NEAT1 may provide a novel insight for the treatment of sepsis-induced ALI.

Transcription factor Sp1 ameliorates sepsis-induced myocardial injury via ZFAS1/Notch signaling in H9C2 cells

PURPOSE

To investigate whether Sp1 can ameliorate sepsis-induced myocardial injury and explore the potential molecular mechanism.

METHODS

The embryonic cardiomyocyte cell line H9C2 and primary cultured mouse neonatal cardiomyocytes (CMNCs) were treated with LPS or phosphate-buffered saline (PBS). A mouse model of LPS-induced sepsis was established using male C57BL/6J mice and their cardiomyocytes were collected. Real-time reverse transcription-PCR (qRT-PCR) assay was used to detect the expression levels of Sp1 and ZFAS1 in cardiomyocytes. Western blotting analysis was used to assess the protein expression levels of Sp1, apoptosis-associated proteins and Notch signaling pathway related proteins. Luciferase assay was used to detect the interaction between Sp1 and ZFAS1. Cell transfection was used to generate H9C2 cells with overexpressed or knocked down of Sp1 or ZFAS1. MTT assay and flow cytometry analysis were used to test the cell proliferation and cell apoptosis ratio.

RESULTS

Our data revealed that the expressions of ZFAS1 and Sp1 were significantly reduced in LPS-treated H9C2 cells and primary CMNCs. The downregulation of ZFAS1 and Sp1 were also found in cardiomyocytes obtained from LPS-challenged mice. LPS induced H9C2 cell apoptosis and depressed cell proliferation was ameliorated by ZFAS1 overexpression and aggravated by ZFAS1 knockdown. Mechanistically, Luciferase assay indicated that Sp1 could bind to ZFAS1, and positively regulated ZFAS1 expression. Moreover, Notch signaling pathway participates in H9C2 cell apoptosis mediated by Sp1.

CONCLUSION

The present study demonstrates that Sp1 regulates LPS-induced cardiomyocyte apoptosis via ZFAS1/Notch signaling pathway, which may serve as therapeutic targets for sepsis-induced myocardial injury.

microRNA-27b shuttled by mesenchymal stem cell-derived exosomes prevents sepsis by targeting JMJD3 and downregulating NF-κB signaling pathway

Background

Exosomal microRNAs (miRs) derived from mesenchymal stem cells (MSCs) have been shown to play roles in the pathophysiological processes of sepsis. Moreover, miR-27b is highly enriched in MSC-derived exosomes. Herein, we aimed to investigate the potential role and downstream molecular mechanism of exosomal miR-27b in sepsis.

Methods

Inflammation was induced in bone marrow-derived macrophages (BMDMs) by lipopolysaccharide (LPS), and mice were made septic by cecal ligation and puncture (CLP). The expression pattern of miR-27b in MSC-derived exosomes was characterized using RT-qPCR, and its downstream gene was predicted by in silico analysis. The binding affinity between miR-27b, Jumonji D3 (JMJD3), or nuclear factor κB (NF-κB) was characterized to identify the underlying mechanism. We induced miR-27b overexpression or downregulation, along with silencing of JMJD3 or NF-κB to examine their effects on sepsis. The production of pro-inflammatory cytokines TNF-α, IL-1β, and IL-6 was detected by ELISA.

Results

miR-27b was highly expressed in MSC-derived exosomes. Mechanistic investigations showed that miR-27b targeted JMJD3. miR-27b decreased expression of pro-inflammatory genes by inhibiting the recruitment of JMJD3 and NF-κB at gene promoter region. Through this, MSC-derived exosomal miR-27b diminished production of pro-inflammatory cytokines in LPS-treated BMDMs and septic mice, which could be rescued by upregulation of JMJD3 and NF-κB. Besides, in vitro findings were reproduced by in vivo findings.

Conclusion

These data demonstrated that exosomal miR-27b derived from MSCs inhibited the development of sepsis by downregulating JMJD3 and inactivating the NF-κB signaling pathway.

Prognostic nomogram for 30-day mortality of deep vein thrombosis patients in intensive care unit

Background

We aimed to use the Medical Information Mart for Intensive Care III database to build a nomogram to identify 30-day mortality risk of deep vein thrombosis (DVT) patients in intensive care unit (ICU).

Methods

Stepwise logistic regression and logistic regression with least absolute shrinkage and selection operator (LASSO) were used to fit two prediction models. Bootstrap method was used to perform internal validation.

Results

We obtained baseline data of 535 DVT patients, 91 (17%) of whom died within 30 days. The discriminations of two new models were better than traditional scores. Compared with simplified acute physiology score II (SAPSII), the predictive abilities of two new models were improved (Net reclassification improvement [NRI] > 0; Integrated discrimination improvement [IDI] > 0; P < 0.05). The Brier scores of two new models in training set were 0.091 and 0.108. After internal validation, corrected area under the curves for two models were 0.850 and 0.830, while corrected Brier scores were 0.108 and 0.114. The more concise model was chosen to make the nomogram.

Conclusions

The nomogram developed by logistic regression with LASSO model can provide an accurate prognosis for DVT patients in ICU.

Identification of Potential Diagnostic Gene Targets for Pediatric Sepsis Based on Bioinformatics and Machine Learning

Purpose: To develop a comprehensive differential expression gene profile as well as a prediction model based on the expression analysis of pediatric sepsis specimens. Methods: In this study, compared with control specimens, a total of 708 differentially expressed genes in pediatric sepsis (case-control at a ratio of 1:3) were identified, including 507 up-regulated and 201 down-regulated ones. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of differentially expressed genes indicated the close interaction between neutrophil activation, neutrophil degranulation, hematopoietic cell lineage, Staphylococcus aureus infection, and periodontitis. Meanwhile, the results also suggested a significant difference for 16 kinds of immune cell compositions between two sample sets. The two potential selected biomarkers (MMP and MPO) had been validated in septic children patients by the ELISA method. Conclusion: This study identified two potential hub gene biomarkers and established a differentially expressed genes-based prediction model for pediatric sepsis, which provided a valuable reference for future clinical research.

Extracellular vesicles as regulators of kidney function and disease

Extracellular vesicles (EVs) are small, lipid bilayer-delimited particles of cellular origin that recently gained increasing attention for their potential use as diagnostic biomarkers, and beyond that for their role in intercellular communication and as regulators of homeostatic and disease processes. In acute kidney injury (AKI) and chronic kidney disease (CKD), the potential use of EVs as diagnostic and prognostic markers has been evaluated in a series of clinical studies and contributions to pathophysiologic pathways have been investigated in experimental models. While EV concentrations in biofluids could not distinguish renal patients from healthy subjects or determine disease progression, specific EV subpopulations have been identified that may provide useful diagnostic and prognostic tools in AKI. Specific EV subpopulations are also associated with clinical complications in sepsis-induced AKI and in CKD. Beyond their role as biomarkers, pathophysiologic involvement of EVs has been shown in hemolytic uremic syndrome- and sepsis-induced AKI as well as in cardiovascular complications of CKD. On the other hand, some endogenously formed or therapeutically applied EVs demonstrate protective effects pointing toward their usefulness as emerging treatment strategy in kidney disease.

microRNA-103a-3p confers protection against lipopolysaccharide-induced sepsis and consequent multiple organ dysfunction syndrome by targeting HMGB1

BACKGROUND

Sepsis and subsequent multiple organ dysfunction syndrome (MODS) have high global incidence and mortality rate, imposing tremendous health burden. microRNAs (miRNAs or miRs) are implicated in the pathogenesis of sepsis and MODS. The aim of this study is to explore the potential mechanisms of miR-103a-3p targeted high mobility group box 1 (HMGB1) involvement in the pathogenesis of sepsis complicated with multiple organ dysfunction syndrome (MODS).

METHODS

A mouse sepsis model was induced by lipopolysaccharide (LPS). Bone marrow-derived macrophages were collected and LPS was used to establish a cellular inflammation model. Targeted binding between miR-103a-3p and HMGB1 was verified by a double luciferase assay and their roles in LPS-induced sepsis were further explored using gain-of-function experiments.

RESULTS

miR-103a-3p was decreased while HMGB1 was increased in sepsis. In LPS-induced mouse sepsis models, the downregulation of HMGB1 was found to result in reductions in NO, TNF-α, IL-1β, IL-6, lung myeloperoxidase activity, pulmonary microvascular albumin leakage, serum alanine aminotransferase, aspartate aminotransferase activity, and lung and liver tissue apoptosis. Additionally, decreased HMGB1 blunted the inflammatory response and increased survival rate of modeled mice. Importantly, HMGB1 was confirmed to a target gene of miR-103a-3p. In cellular inflammation models, miR-103a-3p was found to alleviate LPS-induced sepsis and MODS in vitro by decreasing HMGB1.

CONCLUSIONS

Taken together, our results demonstrated the inhibitory role of miR-103a-3p in sepsis via inhibiting HMGB1 expression.

MicroRNA-96 is downregulated in sepsis neonates and attenuates LPSinduced inflammatory response by inhibiting IL-16 in monocytes

BACKGROUND

Neonatal sepsis (NS) remains one of the leading causes of mortality among newborns. This study found the deregulated microRNA-96 (miR-96) in NS neonates, and aimed to evaluate the clinical significance of miR-96, as well as its effect on LPS-induced inflammatory response in monocytes. In addition, the relationship of interleukin-16 (IL16) and miR-96 was investigated to understand the underlying mechanisms.

METHODS

Expression of miR-96 was examined using real-time quantitative PCR. Monocytes stimulated by LPS was used to mimic excessive inflammation in the pathogenesis of NS. The enzyme-linked immunosorbent assay was applied to evaluate pro-inflammatory cytokines levels. A luciferase reporter assay was used to confirm the interaction between miR-96 and IL16.

RESULTS

Serum miR-96 expression was decreased in NS newborns and had considerable diagnostic value for NS screening. LPS inhibited miR-96 expression in monocytes, and the overexpression of miR-96 could reverse the effects of LPS on the inflammation of monocytes. IL-16 was a target gene of miR-96 and negatively correlated with miR-96 levels in NS neonates. The inhibited inflammatory responses induced by miR-96 overexpression was abolished by the elevated IL-16 in monocytes.

CONCLUSION

All the data reveal that serum decreased miR-96 may serve as a candidate non-invasive biomarker for NS diagnosis. In addition, miR-96 inhibits LPS-induced inflammatory responses by targeting IL-16 in monocytes. The miR96/IL-16 axis may provide novel therapeutic targets for NS treatment.

TLR4 Response to LPS Is Reinforced by Urokinase Receptor

GPI-anchored uPAR is the receptor for the extracellular serine protease urokinase-type plasminogen activator (uPA). Though uPAR role in inflammatory processes is documented, underlying mechanisms are not fully understood. In this study we demonstrate that uPAR is a part of Toll-like receptor 4 (TLR4) interactome. Downregulation of uPAR expression resulted in diminished LPS-induced TLR4 signaling, less activation of NFκB, and decreased secretion of inflammatory mediators in myeloid and non-myeloid cells in vitro. In vivo uPAR−/− mice demonstrated better survival, strongly diminished inflammatory response and better organ functions in cecal ligation and puncture mouse polymicrobial sepsis model. Mechanistically, GPI-uPAR and soluble uPAR colocalized with TLR4 on the cell membrane and interacted with scavenger receptor CD36. Our data show that uPAR can interfere with innate immunity response via TLR4 and this mechanism represents a potentially important target in inflammation and sepsis therapy.

Lipopolysaccharide exposure induces oxidative damage in Caenorhabditis elegans: protective effects of carnosine

Background

The present study was designed to investigate the protective effects and mechanisms of carnosine on lipopolysaccharide (LPS)-induced injury in Caenorhabditis elegans.

Methods

C. elegans individuals were stimulated for 24 h with LPS (100 μg/mL), with or without carnosine (0.1, 1, 10 mM). The survival rates and behaviors were determined. The activities of superoxide dismutase (SOD), glutathione reductase (GR), and catalase (CAT) and levels of malondialdehyde (MDA) and glutathione (GSH) were determined using the respective kits. Reverse transcription polymerase chain reaction (RT-PCR) was performed to validate the differential expression of sod-1, sod-2, sod-3, daf-16, ced-3, ced-9, sek-1, and pmk-1. Western blotting was used to determine the levels of SEK1, p38 mitogen-activated protein kinase (MAPK), cleaved caspase3, and Bcl-2. C. elegans sek-1 (km2) mutants and pmk-1 (km25) mutants were used to elucidate the role of the p38 MAPK signaling pathway.

Results

Carnosine improved the survival of LPS-treated C. elegans and rescued behavioral phenotypes. It also restrained oxidative stress by decreasing MDA levels and increasing SOD, GR, CAT, and GSH levels. RT-PCR results showed that carnosine treatment of wild-type C. elegans up-regulated the mRNA expression of the antioxidant-related genes sod-1, sod-2, sod-3, and daf-16. The expression of the anti-apoptosis-related gene ced-9 and apoptosis-related gene ced-3 was reversed by carnosine. In addition, carnosine treatment significantly decreased cleaved caspase3 levels and increased Bcl-2 levels in LPS-treated C. elegans. Apoptosis in the loss-of-function strains of the p38 MAPK signaling pathway was suppressed under LPS stress; however, the apoptotic effects of LPS were blocked in the sek-1 and pmk-1 mutants. The expression levels of sek-1 and pmk-1 mRNAs were up-regulated by LPS and reversed by carnosine. Finally, the expression of p-p38MAPK and SEK1 was significantly increased by LPS, which was reversed by carnosine.

Conclusion

Carnosine treatment protected against LPS injury by decreasing oxidative stress and inhibiting apoptosis through the p38 MAPK pathway.

Overexpression of miR-451a in sepsis and septic shock patients is involved in the regulation of sepsis-associated cardiac dysfunction and inflammation

The purpose of this study was to investigate the expression and clinical value of microRNA-451a (miR-451a) in septic patients and analyze its effect on sepsis-associated cardiac dysfunction and inflammation response. A rat model of sepsis was constructed by cecal ligation and puncture. The expression of miR-451a was measured by quantitative real-time PCR. Receiver operating characteristic (ROC) analysis was used to assess the diagnostic value of serum miR-451a. The cardiac function and inflammatory responses in septic rats were measured to explore the functional role of miR-451a. Serum expression of miR-451a was increased in septic patients compared with healthy controls, and had the ability to distinguish septic patients from healthy volunteers with a sensitivity and specificity of 87.8% and 81.5%, respectively. Elevated serum miR-451a was associated with sepsis severity, as evidenced by the increased expression of miR-451a in septic shock patients and its correlation with key clinical indicators. Significantly upregulated expression of miR-451a was found in septic patients with cardiac dysfunction, and the knockdown of miR-451a in sepsis rats improved cardiac function and inhibited inflammatory responses. All the data revealed that serum miR-451a serves as a candidate diagnostic biomarker of sepsis and a potential parameter to indicate disease severity. The reduction of miR-451a may mitigate sepsis-induced cardiac dysfunction and inflammatory responses.

Nanotechnological strategies for systemic microbial infections treatment: A review

Systemic infections is one of the major causes of mortality worldwide, and a shortage of drug approaches applied for the rapid and necessary treatment contribute to increase the levels of death in affected patients. Several drug delivery systems based in nanotechnology such as metallic nanoparticles, liposomes, nanoemulsion, microemulsion, polymeric nanoparticles, solid lipid nanoparticles, dendrimers, hydrogels and liquid crystals can contribute in the biological performance of active substances for the treatment of microbial diseases triggered by fungi, bacteria, virus and parasites. In the presentation of these statements, this review article present and demonstrate the effectiveness of these drug delivery systems for the treatment of systemic diseases caused by several microorganisms, through a review of studies on scientific literature worldwide that contributes to better information for the most diverse professionals from the areas of health sciences. The studies demonstrated that the drug delivery systems described can contribute to the therapeutic scenario of these diseases, being classified as safe, active platforms and with therapeutic versatility.

Shenfu injection prevents sepsis-induced myocardial injury by inhibiting mitochondrial apoptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Shenfu injection (SFI) is a well-known Chinese herbal medicine widely used in the treatment of septic shock in China.

AIMS

The aims of this study are to investigate the protective effects of SFI on sepsis-induced myocardial injury in mice and to identify the underlying mechanism of action.

MATERIALS AND METHODS

Seventy-two male C57/B6J mice (5-6 weeks old) were randomly divided into five groups: control (NC), sham sepsis (sham), sepsis (Lipopolysaccharide- LPS), sepsis treated with a low dose SFI, and sepsis treated with a high dose SFI. Sepsis was induced in mice by intraperitoneal injection of LPS. Myocardial tissue samples were collected from different groups at 6 h, 12 h, and 24 h post-LPS injection. Myocardial injury was examined using hematoxylin-eosin (H&E) and TUNEL staining. Western-blot analysis was performed to determine the protein expression of B-cell lymphoma 2 (Bcl-2), BH3 interacting-domain death agonist (Bid), truncated-Bid (t-Bid) and caspase-9 in all the groups. Moreover, the structural changes in the mitochondria of cardiomyocytes were also observed by transmission electron microscopy.

RESULTS

H&E staining revealed structural damage, local necrosis, interstitial edema, inflammatory cell infiltration and vacuolar changes in the myocardial tissue in the sepsis (LPS) group; almost intact myocardial tissue was observed in the high dose SFI group with improvements in interstitial edema and inflammatory cell infiltration. We observed that LPS-induced cardiomyocyte apoptosis was significantly improved with high dose SFI as compared with sepsis (LPS) group (P ˂ 0.05). LPS was found to decrease the protein expression of Bcl-2 and increase the level of Bid, t-Bid and caspase-9. Treatment with SFI significantly increased the Bcl-2 protein expression (P ˂ 0.05) and decreased the protein expression of Bid, t-Bid and caspase-9 as compared with LPS group (P ˂ 0.05). Markedly swollen myocardial mitochondria with partial vacuolation were observed in LPS treated mice while SFI treatment was found to significantly improve the LPS-induced morphological damage of the mitochondria.

CONCLUSION

In conclusion, we demonstrate that SFI protects against sepsis-induced myocardial injury in mice through the suppression of myocardial apoptosis. It upregulates the protein expression of Bcl-2 and downregulates the protein expression of Bid, t-Bid and caspase-9, and alleviates sepsis-induced mitochondrial damage.

LncRNA H19 Inhibits the Progression of Sepsis-Induced Myocardial Injury via Regulation of the miR-93-5p/SORBS2 Axis

Sepsis is an infectious disease that seriously endangers human health. It usually leads to myocardial injury which seriously endangers to the health of human beings. H19 has been confirmed to play key roles in various diseases, including sepsis. However, its function in the progression of sepsis-induced myocardial injury remains largely unknown. H9C2 cells were treated with lipopolysaccharide (LPS) to mimic sepsis-induced myocardial injury in vitro. Cell proliferation and apoptosis were detected by MTT assay and flow cytometry, respectively. In addition, gene and protein expression levels in H9C2 cells were measured by quantitative real-time PCR (qRT-PCR) and Western blotting. The levels of inflammatory cytokines in H9C2 cell supernatants were tested by ELISA. JC-1 staining was performed to observe the mitochondrial membrane potential level in H9C2 cells. H19 and SORBS2 were downregulated in H9C2 cells following LPS treatment, while miR-93-5p was upregulated. Moreover, LPS-induced cell growth inhibition and mitochondrial damage were significantly reversed by overexpression of H19. In addition, H19 upregulation notably suppressed LPS-induced inflammatory responses in H9C2 cells. Moreover, H19 sponged miR-93-5p to promote SORBS2 expression. Overall, H19 suppressed sepsis-induced myocardial injury via regulation of the miR-93-5p/SORBS2 axis. H19 attenuated the development of sepsis-induced myocardial injury in vitro via modulation of the miR-93-5p/SORBS2 axis. Thus, H19 could serve as a potential target for the treatment of sepsis-induced myocardial injury.

Diosmetin alleviates acute kidney injury by promoting the TUG1/Nrf2/HO-1 pathway in sepsis rats

BACKGROUND

We aimed to study the effects and the underlying mechanisms of Diosmetin (DIOS) in rats with sepsis-induced acute kidney injury (AKI).

METHODS

The AKI model in RMCs was induced using LPS, and the cells were then treated with DIOS. Cell viability, apoptosis, inflammatory response, and antioxidant were measured using MTT, Flow cytometry, ELISA, and Lucigenin assay, respectively. The correlation between TUG1 and Nrf2 was confirmed by RNA pull-down and RNA immunoprecipitation. Real-time quantitative PCR and Western blot were performed to detect the expressions of gene and proteins during the development of AKI. The effects of lncRNA-TUG1 silencing and Nrf2 silencing on cell physiological functions were detected. Moreover, a rat sepsis-induced AKI model followed by Hematoxylin & Eosin (H&E) and immunofluorescence staining were performed.

RESULTS

The experimental concentration of DIOS was determined to be 20 μM. After LPS treatment, the activity of RMCs was decreased, the apoptosis rate, inflammation and oxidative stress damage were increased, moreover, the expression of Nrf2/HO-1 signal axis was inhibited and caspase-3 was activated. However, DIOS significantly reversed these effects caused by LPS treatment, and increased the expression of lncRNA-TUG1, but lncRNA-TUG1 silencing effectively reversed the effects of DIOS. In addition, lncRNA-TUG1 was found to interact with Nrf2. Overexpression of TUG1 could reduce the damage of LPS caused to cell physiological functions, which were reversed by siNrf2. Thus, DIOS treatment could improve the physiological and pathological damages of renal tissues in AKI rats.

CONCLUSION

DIOS may reduce sepsis-induced AKI through enhancing the TUG1/Nrf2/HO-1 pathway.

Blocking ADAM17 Function with a Monoclonal Antibody Improves Sepsis Survival in a Murine Model of Polymicrobial Sepsis

Sepsis is the culmination of hyperinflammation and immune suppression in response to severe infection. Neutrophils are critical early responders to bacterial infection but can become highly dysfunctional during sepsis and other inflammatory disorders. The transmembrane protease ADAM17 (a disintegrin and metalloproteinase 17) is expressed by leukocytes and most other cells and has many substrates that regulate inflammation. We have reported that conditional knockout mice lacking ADAM17 in all leukocytes had a survival advantage during sepsis, which was associated with improved neutrophil effector functions. These and other findings indicate aberrant ADAM17 activity during sepsis. For this study, we evaluated for the first time the effects of an ADAM17 function blocking monoclonal antibody (mAb) on the pathogenesis of polymicrobial sepsis. Mice treated with the ADAM17 mAb MEDI3622 prior to sepsis induction exhibited significantly decreased mortality. When the ADAM17 mAb was combined with antibiotic administration, sepsis survival was markedly enhanced compared to either intervention alone, which was associated with a significant reduction in plasma levels of various inflammation-related factors. MEDI3622 and antibiotic administration after sepsis induction also significantly improved survival. Our results indicate that the combination of blocking ADAM17 as an immune modulator and appropriate antibiotics may provide a new therapeutic avenue for sepsis treatment.

Inducible Nitric Oxide Synthase in Circulating Microvesicles: Discovery, Evolution, and Evidence as a Novel Biomarker and the Probable Causative Agent for Sepsis

Background

The sepsis pathology remains an enormous medical problem globally because morbidity and mortality remain unacceptably high in septic patients despite intense research efforts. The economic and societal burden of sepsis makes it the most pressing patient care issue in the United States and worldwide. Sepsis is a dysregulated immune response normally initiated by an infection. The need for an early, accurate, and reliable biomarker test to detect the onset of sepsis and for a targeted sepsis therapy are widely recognized in the biomedical community.

Content

This report reviews the published findings relevant to microvesicle-associated inducible nitric oxide synthase (MV-A iNOS) as a novel plasma biomarker for the onset of sepsis including human clinical studies and animal studies. Plasma iNOS as a standalone test and as one of the components of a novel panel of biomarkers to stage the progression of sepsis are presented and discussed in comparison to other biomarkers and other proposed panels of biomarkers for sepsis.

Summary

The data strongly support the concept that extracellular plasma MV-A iNOS in circulating microvesicles is centrally involved in the initiation of sepsis, and a diagnostic test based upon plasma iNOS can serve as an early pre-symptomatic warning signal for the onset of sepsis. A novel panel of plasma biomarkers comprised of iNOS, pro-IL-18, pro-IL-33, and Reg-1α is proposed as a multianalyte pre-symptomatic method to stage the onset of sepsis for improved prompt data driven patient care.

Update on diagnosis and management of sepsis in cirrhosis: Current advances

Sepsis and septic shock are catastrophic disease entities that portend high mortality in patients with cirrhosis. In cirrhosis, hemodynamic perturbations, immune dysregulation, and persistent systemic inflammation with altered gut microbiota in the background of portal hypertension enhance the risk of infections and resistance to antimicrobials. Patients with cirrhosis develop recurrent life-threatening infections that progress to multiple organ failure. The definition, pathophysiology, and treatment options for sepsis have been ever evolving. In this exhaustive review, we discuss novel advances in the understanding of sepsis, describe current and future biomarkers and scoring systems for sepsis, and delineate newer modalities and adjuvant therapies for the treatment of sepsis from existing literature to extrapolate the same concerning the management of sepsis in cirrhosis. We also provide insights into the role of gut microbiota in initiation and progression of sepsis and finally, propose a treatment algorithm for management of sepsis in patients with cirrhosis.

LncRNA THRIL aggravates sepsis-induced acute lung injury by regulating miR-424/ROCK2 axis

Here, we aimed to investigate the role of long noncoding RNA (lncRNA) THRIL in septic-induced acute lung injury. C57BL/6 mice were injected with Adenoviruses (Ad)-shTHRIL or negative control (NC) before caecal ligation and puncture (CLP) operation. MPVECs were transfected with Ad-shTHRIL or NC, followed by lipopolysaccharide (LPS) treatment. MiR-424 and Rho-associated kinase 2 (ROCK2) were predicted and verified as direct targets of THRIL and miR-424, respectively, by using dual-luciferase reporter assay. ROCK2 overexpression vector and shTHRIL were co-transfected into mouse pulmonary microvascular endothelial cells for 24 h before LPS treatment. Our results showed that THRIL was highly expressed in the lung of sepsis mice. CLP triggered severe lung injury and apoptosis in mice, which was abolished by THRIL knockdown. Moreover, CLP treatment visibly increased protein concentration, the number of total cell of neutrophils, and macrophages in bronchoalveolar lavage fluid (BALF). Besides, elevated protein levels of tumor necrosis factor-α, interleukin-1β, and interleukin-6 were observed in both lung and BALF. However, inhibition of THRIL reduced the number of inflammatory cells and the production of pro-inflammatory cytokines in sepsis mouse model. The effect of THRIL on inflammatory response and apoptosis in the lung was confirmed in sepsis cell model. Moreover, mechanistic studies have shown that THRIL up-regulated ROCK2 level through sponging miR-424. Furthermore, ROCK2 overexpression reversed the inhibitory effects of THRIL knockdown on LPS-induced inflammatory response and apoptosis. Overall, in vivo and in vitro results suggested that THRIL accelerates sepsis-induced lung injury by sponging miR-424 and further restoring ROCK2.

CD204-positive monocytes and macrophages ameliorate septic shock by suppressing proinflammatory cytokine production in mice

Sepsis is defined as a life-threatening multiorgan dysfunction caused by dysregulated inflammatory response to infection. It remains the primary cause of death from infection if not diagnosed and treated promptly. Therefore, a better understanding of the mechanism for resolving inflammation is needed. Monocytes and macrophages play a pivotal role not only in the induction but also in the suppression of inflammation. However, a tissue-resident macrophage subset that regulates a hyperinflammatory state during sepsis has not been explored. Here we show that CD204⁺ monocytes and/or macrophages rescued mice from endotoxin-induced septic shock. Serum and tissue proinflammatory cytokine levels were significantly upregulated in the absence of these cells. This study provided evidence that CD204⁺ monocytes and/or macrophages ameliorate septic shock by suppressing proinflammatory cytokine production.

Use of Intravenous Immunoglobulins in Sepsis Therapy-A Clinical View

Sepsis is a life-threatening organ dysfunction, defined by a dysregulated host immune response to infection. During sepsis, the finely tuned system of immunity, inflammation and anti-inflammation is disturbed in a variety of ways. Both pro-inflammatory and anti-inflammatory pathways are upregulated, activation of the coagulation cascade and complement and sepsis-induced lymphopenia occur. Due to the manifold interactions in this network, the use of IgM-enriched intravenous immunoglobulins seems to be a promising therapeutic approach. Unfortunately, there is still a lack of evidence-based data to answer the important questions of appropriate patient populations, optimal timing and dosage of intravenous immunoglobulins. With this review, we aim to provide an overview of the role of immunoglobulins, with emphasis on IgM-enriched formulations, in the therapy of adult patients with sepsis and septic shock.

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.

Circular RNA expression in the lungs of a mouse model of sepsis induced by cecal ligation and puncture

Circular RNAs (circRNAs) are novel endogenous RNAs with vital roles in the pathology of various diseases. However, their role in sepsis-induced lung injury is unknown. In this study, high-throughput gene sequencing was used to analyze the expression profiles of circRNAs in lung specimens of mice grouped by acute lung injury induced by cecal ligation and puncture (CLP) and sham. To identify differentially expressed circRNAs, the left lungs of sham (n = 3) and CLP (n = 3) mice were used for high-throughput sequencing. A total of 919 circRNAs were identified. Of these, 38 circRNAs showed significantly different expression levels between the groups (P < 0.05, fold change ≥2). The levels of 20 circRNAs were up-regulated and those of 18 others were down-regulated. In bioinformatics analysis of the source genes of these circRNAs, the genes were closely associated with the inflammatory response (e.g., the TGF-β, MAPK, Fc gamma R-mediated phagocytic, and VEGF pathways). Eight circRNAs with large intergroup differences, small intragroup differences, and high expression were selected for further validation by qRT-PCR. Two of the eight were significantly different. These two circRNAs were annotated with circRNA/miRNA interaction information downloaded from the TargetScan and miRanda databases and visualized. Our results provide novel insights into the roles of circRNAs in sepsis-induced acute lung injury.

Single-Sampling Strategy vs. Multi-Sampling Strategy for Blood Cultures in Sepsis: A Prospective Non-inferiority Study

Background

Optimal sampling is critical for the performance of blood cultures (BCs). Most guidelines recommend collecting 40 ml of blood, divided between two venipuncture sites, i.e., multi-sampling strategy (MSS). Sampling through a single venipuncture site, i.e., single-sampling strategy (SSS) is easier; however, the diagnostic performance of SSS compared to MSS remains unknown. Thus, we aimed to study if SSS is non-inferior to MSS for detection of pathogenic microorganisms.

Methods

A prospective, paired, non-inferiority design was used. Patients with clinically suspected sepsis admitted to an Emergency Department were included. Six BC bottles were simultaneously collected, consisting of four BC bottles from the first arm and two from the other arm. SSS consisted of BC bottles 1, 2, 3, and 4, and MSS consisted of BC bottles 1, 2, 5, and 6. Samples were incubated in a BacT/ALERT BC system.

Results

The final analysis included 549 episodes. Pathogenic microorganisms were detected in 162 cases (29.5%) with MSS and 160 cases (29.1%) with SSS, yielding an absolute difference of 0.36%, with a 95% confidence interval of -1.33 to 2.06%, which did not exceed the predefined non-inferiority margin of 5%. MSS tended to produce more contaminant growth (7.3% of cases) than SSS (5.3% of cases; p = 0.072).

Conclusion

The study showed that SSS was non-inferior to MSS in detecting pathogenic microorganisms and supports the use of SSS as a routine method.

17β-Estradiol Promotes Trained Immunity in Females Against Sepsis via Regulating Nucleus Translocation of RelB

Sepsis is more common among males than females, and the unequal estrogen levels have been suspected to play a vital role in gender differences. Recently, trained immunity is reported to be a novel strategy for the innate immune system to fight infection. However, it has not been clarified whether β-glucan-induced trained immunity causes different responses to early sepsis between male and female mice. In this study, sepsis was induced in mice by intraperitoneal injection of Escherichia coli (E. coli). The changes of inflammatory cytokines expression, and macrophage polarization in male, female, and ovariectomized C57BL/6 mice in sepsis model were investigated. For in vitro studies, different macrophages were treated with LPS. The function of estradiol (E2) on macrophage cell lines was verified and the mechanism of E2 affecting trained immunity was explored. We demonstrated that β-glucan-induced trained immunity was more resistant to sepsis in female than male mice. Macrophage polarization toward the M1 phenotype, which exhibited enhanced trained immunity, was related to the difference in sepsis resistance between female and male mice. Moreover, ovariectomized (OVX) mice manifested serious sepsis consequences with a weaker trained immunity effect than female mice. Female bone marrow-derived macrophages (BMDMs) were also apt to be polarized to the M1 phenotype in response to trained immunity in vitro. Furthermore, E2 promoted trained immunity in macrophage cell lines J774 and RAW264.7. E2 was also verified to facilitate trained immunity in primary BMDMs from female and male mice. Mechanistically, we found that E2 inhibited the nuclear translocation of RelB, which is a member of non-canonical pathway of NFκB and contributes to macrophage polarization to change the intensity of trained immunity. This study is the first to indicate the role of E2 in the trained immunity induced by β-glucan to protect against E. coli-induced sepsis via the non-canonical NFκB pathway. These results improve our understanding of the molecular mechanisms governing trained immunity in gender differences.

Calcitonin Gene-Related Peptide Attenuates LPS-Induced Acute Kidney Injury by Regulating Sirt1

BACKGROUND Acute kidney injury (AKI) caused by sepsis is a very dangerous clinical complication. This study explored the effects of calcitonin gene-related peptides (CGRP) on AKI and its mechanisms. MATERIAL AND METHODS We cultured renal proximal tubular epithelial cells (HK-2 cells) and induced AKI models using LPS. Recombinant human CGRP was used to stimulate HK-2 cells and we detected markers of kidney injury (KIM-1 and NGAL) to determine the protective effect of CGRP on HK-2 cells. In addition, we constructed Sirt1-overexpressing lentivirus and small interfering RNA to increase or decrease Sirt1 expression in HK-2 cells to verify that CGRP protects HK-2 cells by regulating Sirt1. RESULTS After CGRP stimulation of HK-2 cells, LPS-induced HK-2 cell damage was significantly ameliorated, showing a decrease in the expression of KIM-1, NGAL, and inflammatory factors. In addition, Sirt1 was significantly increased in CGRP-stimulated HK-2 cells. After transfection of HK-2 cells with Lenti-Sirt1, inflammation and damage of HK-2 cells were both reduced, indicating that Sirt1 has a protective effect on HK-2 cells and can mediate the protective effect of CGRP on HK-2 cells. Therefore, the protective effect of CGRP on HK-2 cells was also attenuated after reducing Sirt1 in HK-2 cells. Finally, we used CGRP to treat LPS-induced mice and verified the protective effect of CGRP on mouse AKI. CONCLUSIONS CGRP has a significant anti-inflammatory effect. In the treatment of AKI, CGRP can increase the expression of Sirt1 to exert an anti-inflammatory effect and has a good protective effect on LPS-induced HK-2 cells.

Immunologic Effects of Vitamin D on Human Health and Disease

Vitamin D is responsible for regulation of calcium and phosphate metabolism and maintaining a healthy mineralized skeleton. It is also known as an immunomodulatory hormone. Experimental studies have shown that 1,25-dihydroxyvitamin D, the active form of vitamin D, exerts immunologic activities on multiple components of the innate and adaptive immune system as well as endothelial membrane stability. Association between low levels of serum 25-hydroxyvitamin D and increased risk of developing several immune-related diseases and disorders, including psoriasis, type 1 diabetes, multiple sclerosis, rheumatoid arthritis, tuberculosis, sepsis, respiratory infection, and COVID-19, has been observed. Accordingly, a number of clinical trials aiming to determine the efficacy of administration of vitamin D and its metabolites for treatment of these diseases have been conducted with variable outcomes. Interestingly, recent evidence suggests that some individuals might benefit from vitamin D more or less than others as high inter-individual difference in broad gene expression in human peripheral blood mononuclear cells in response to vitamin D supplementation has been observed. Although it is still debatable what level of serum 25-hydroxyvitamin D is optimal, it is advisable to increase vitamin D intake and have sensible sunlight exposure to maintain serum 25-hydroxyvitamin D at least 30 ng/mL (75 nmol/L), and preferably at 40-60 ng/mL (100-150 nmol/L) to achieve the optimal overall health benefits of vitamin D.

Apoptotic cell therapy for cytokine storm associated with acute severe sepsis

Sepsis has no proven pharmacologic treatment other than appropriate antibiotic agents, fluids, vasopressors as needed, and possibly corticosteroids. It is generally initiated mainly by the simultaneous recognition by various components of the innate immune system of either pathogen-associated molecular patterns (PAMPs) or damage-associated molecular patterns (DAMPs). In the current study, we employed the murine cecal ligation and puncture (CLP) model for sepsis to evaluate the effect of post-CLP infusion of apoptotic cells (Allocetra-OTS) on a CLP severe sepsis model. Cardiovascular evaluation, acute kidney injury (AKI), acute liver injury (ALI), and hematological and metabolic function were evaluated. Cytokine and chemokine profiles were measured by Multiplex ELISA and mitochondrial function, and glycolysis by Seahorse. The Murine Sepsis Score (MSS) was used for disease severity definition. CLP mice had low blood pressure, poor cardiac output, and lung dysfunction, as well as AKI, ALI, and thrombocytopenia, which correlated with the MSS and corresponded to a cytokine/chemokine storm. Apoptotic cell administration markedly improved the cytokine and chemokine storm and restored the impaired mitochondrial and glycolytic function in white blood cells leading to increased survival, from 6 to 60% (P < 0.0001), together with a significant improvement in organ dysfunction. We conclude that the deleterious immune response in CLP-induced sepsis can be successfully modified by apoptotic cell infusion.

FDA-approved disulfiram inhibits pyroptosis by blocking gasdermin D pore formation

Cytosolic sensing of pathogens and damage by myeloid and barrier epithelial cells assembles large complexes called inflammasomes, which activate inflammatory caspases to process cytokines (IL-1β) and gasdermin D (GSDMD). Cleaved GSDMD forms membrane pores, leading to cytokine release and inflammatory cell death (pyroptosis). Inhibiting GSDMD is an attractive strategy to curb inflammation. Here we identify disulfiram, a drug for treating alcohol addiction, as an inhibitor of pore formation by GSDMD but not other members of the GSDM family. Disulfiram blocks pyroptosis and cytokine release in cells and lipopolysaccharide-induced septic death in mice. At nanomolar concentration, disulfiram covalently modifies human/mouse Cys191/Cys192 in GSDMD to block pore formation. Disulfiram still allows IL-1β and GSDMD processing, but abrogates pore formation, thereby preventing IL-1β release and pyroptosis. The role of disulfiram in inhibiting GSDMD provides new therapeutic indications for repurposing this safe drug to counteract inflammation, which contributes to many human diseases.

Baicalin suppresses Th1 and Th17 responses and promotes Treg response to ameliorate sepsis-associated pancreatic injury via the RhoA-ROCK pathway

Recent studies have reported that the imbalance of T helper 1 cell (Th1), Th17 and regulatory T cell (Treg) have been confirmed to play a vital role in the development of sepsis and other inflammatory diseases. Baicalin (BA) has anti-inflammatory properties and improves survival in sepsis. We investigated whether baicalin could regulate Th1, Th17 and Treg responses to ameliorate sepsis-associated pancreatic injury through the ras homolog family member A (RhoA)-Rho kinase (ROCK) pathway. The sepsis model was established by using the cecal ligation and puncture (CLP) method. Fifty mice were randomly divided into five groups (n = 10): sham group, model group, low-dose group (BA-L, 100 mg/kg of baicalin), medium-dose group (BA-M, 200 mg/kg of baicalin) and highdose group (BA-H, 300 mg/kg of baicalin). The effects of baicalin on the pancreatic injury, on changes of Th1, Th17 and Treg cells in vivo and in vitro, on RhoA, ROCK1 and signal transducer and activator of transcription (STAT) signaling pathways, and on levels of interferon-γ (IFN-γ), interleukin-17 (IL-17) and IL-10 were examined. Treatment of the CLP mice with baicalin significantly reduced the extent, scope and severity of the pathological changes of sepsis-associated pancreatic injury. Baicalin evidently reduced Th1 and Th17 cells and increased Treg cells in peripheral blood, spleen, pancreatic tissue and significantly inhibited T-box protein expressed in T cells (T-bet), retinoic acid receptor-related orphan receptor γt (RORγt) and increased forkhead/winged helix transcription factor (Foxp3) expressions in the pancreatic tissue. Baicalin reduced the expressions of RhoA, ROCK1, phosphorylated STAT4 (p-STAT4), p-STAT3 and increased the expression of p-STAT5 in peripheral blood, spleen and pancreatic tissue. Baicalin reduced the expressions of IFN-γ and IL-17 and increased the IL-10 in serum and pancreatic tissue. Baicalin is capable of ameliorating sepsis-associated pancreatic injury and regulating Th1, Th17 and Treg responses in sepsis. The present study provided a potential adjunctive therapy for treating pancreatic injury in sepsis, and further study is needed to reveal its deeper mechanisms.