Case report: septic shock after endometrial polypectomy with tissue removal system.

As an emerging surgical technology, tissue removal systems have been widely used in the treatment of endometrial polyps due to its characteristics of less endometrial damage, shorter learning curve and clearer vision of the operative field. There are few cases in the literature reporting serious complications after endometrial polypectomy using tissue removal systems. As known, septic shock is a rare complication following hysteroscopic polypectomy. Now, we present the case of a 23-year-old woman who developed septic shock after polypectomy with tissue removal system. The patient had a history of recurrent vaginitis for more than half a year. Due to endometrial polyps, she was admitted to our hospital and scheduled to undergo hysteroscopic endometrial polypectomy. Three hours after the endometrial polypectomy using the tissue removal system, the patient had shock symptoms such as increased body temperature, decreased blood pressure and increased heart rate. Then, the patient was successfully treated and discharged after anti-infection and anti-shock treatments. The purpose of this case report is to remind clinicians to consider the possibility of serious infection and comprehensively evaluate the risk of infection before choosing hysteroscopic devices for endometrial polyps, especially for patients who choose the mechanical hysteroscopic tissue removal systems. Furthermore, the mechanical hysteroscopic tissue removal systems should be used with caution in patients with previous recurrent vaginitis.

Vagus nerve stimulation attenuates septic shock-induced cardiac injury in rats.

This research aimed to evaluate whether vagus nerve stimulation (VNS) could effectively prevent septic shock-induced cardiac injury in rats and investigate the potential mechanisms. Female Sprague-Dawley rats were divided into the Sham group (sham cecal ligation and puncture [CLP] plus vagal nerve trunk separation), the Vehicle group (CLP plus vagal nerve trunk separation), and the VNS groups (CLP plus vagal nerve trunk separation plus VNS). The left ventricular function was analyzed by echocardiography. Histologic examinations of the cardiac tissues were performed through hematoxylin and eosin staining and TUNEL staining. The Vehicle group had worse cardiac function, higher levels of cardiac injury markers, and enhanced myocardial apoptosis than the Sham group. The rats in the VNS groups had enhanced cardiac function, lower levels of cardiac injury markers, and inhibited myocardial apoptosis than those in the Vehicle group. Elevated interleukin-1beta and tumor necrosis factor-alpha-levels and activated nuclear factor kappa B (NF-kappa-B) signal in septic shock rats were inhibited by the performance of VNS. This study suggests that VNS contributes to the reduction of myocardial apoptosis and improvement of left ventricular function to attenuate septic shock-induced cardiac injury in rats. The performance of VNS inhibits the inflammatory responses in heart tissues via the regulation of NF-kappa-B signal.

Using a multiomics approach to unravel a septic shock specific signature in skeletal muscle.

Sepsis is defined as a dysregulated host response to infection leading to organs failure. Among them, sepsis induces skeletal muscle (SM) alterations that contribute to acquired-weakness in critically ill patients. Proteomics and metabolomics could unravel biological mechanisms in sepsis-related organ dysfunction. Our objective was to characterize a distinctive signature of septic shock in human SM by using an integrative multi-omics approach. Muscle biopsies were obtained as part of a multicenter non-interventional prospective study. Study population included patients in septic shock (S group, with intra-abdominal source of sepsis) and two critically ill control populations: cardiogenic shock (C group) and brain dead (BD group). The proteins and metabolites were extracted and analyzed by High-Performance Liquid Chromatography-coupled to tandem Mass Spectrometry, respectively. Fifty patients were included, 19 for the S group (53% male, 64 ± 17 years, SAPS II 45 ± 14), 12 for the C group (75% male, 63 ± 4 years, SAPS II 43 ± 15), 19 for the BD group (63% male, 58 ± 10 years, SAPS II 58 ± 9). Biopsies were performed in median 3 days [interquartile range 1-4]) after intensive care unit admission. Respectively 31 patients and 40 patients were included in the proteomics and metabolomics analyses of 2264 proteins and 259 annotated metabolites. Enrichment analysis revealed that mitochondrial pathways were significantly decreased in the S group at protein level: oxidative phosphorylation (adjusted p = 0.008); branched chained amino acids degradation (adjusted p = 0.005); citrate cycle (adjusted p = 0.005); ketone body metabolism (adjusted p = 0.003) or fatty acid degradation (adjusted p = 0.008). Metabolic reprogramming was also suggested (i) by the differential abundance of the peroxisome proliferator-activated receptors signaling pathway (adjusted p = 0.007), and (ii) by the accumulation of fatty acids like octanedioic acid dimethyl or hydroxydecanoic. Increased polyamines and depletion of mitochondrial thioredoxin or mitochondrial peroxiredoxin indicated a high level of oxidative stress in the S group. Coordinated alterations in the proteomic and metabolomic profiles reveal a septic shock signature in SM, highlighting a global impairment of mitochondria-related metabolic pathways, the depletion of antioxidant capacities, and a metabolic shift towards lipid accumulation.ClinicalTrial registration: NCT02789995. Date of first registration 03/06/2016.

Morphine-induced microglial immunosuppression via activation of insufficient mitophagy regulated by NLRX1.

BACKGROUND: Chronic morphine exposure induces immunosuppression in the peripheral and central nervous system, resulting in susceptibility of patients to invading pathogens. Mitophagy is a crucial regulator of inflammation, and dysregulated mitophagy may cause immunosuppression, but whether mitophagy is linked with morphine-induced immunosuppression in the brain remains unknown. NLRX1 is the only mitochondrially localized NOD family receptor protein which serves as a critical regulator in immunity and mitophagy activation, but it remains an enigma how NLRX1 functions in the crosstalk between microglial inflammatory defense and mitophagy in the presence of morphine. METHODS: Primary microglia and astrocytes, BV2 and MA cell lines were utilized. Mice were stimulated with repeated morphine treatment to mimic chronic morphine exposure, and activation of mitophagy, lysosomal functions, and inflammation were assayed in specific brain regions and immune organs with or without NLRX1-silencing. RESULTS: Morphine induced microglial mitophagy in a LC3 (microtubule-associated proteins light chain 3)-dependent manner, which was mediated by NLRX1. Contrastingly, morphine impaired lysosomal functions, including generation, acidification and mitophagosome-lysosome fusion, thus leading to insufficient mitophagy activation in microglia. NLRX1-silencing inhibited mitophagy activity and rescued lysosomal functions including generation and acidification in microglia. The NLRX1-mediated incomplete mitophagy in microglial cells contributed to immunosuppression and vulnerability towards pathogenic challenge after morphine treatment. In vivo, NLRX1-mediated microglial mitophagy activation by morphine was mainly located in the murine brain cortex, striatum, and cerebellum, where NLRX1 functioned as a negative immune regulator and facilitated septic shock. Collectively, microglial immune responses to septic shock were amenable to NLRX1 silencing in the brain with morphine treatment. CONCLUSION: Morphine activated insufficient mitophagy in microglia which was regulated by NLRX1, ultimately leading to host immunosuppression and susceptible conditions in the brain.

Mean platelet volume and mean platelet volume to platelet count ratio as predictors of severity and mortality in sepsis.

INTRODUCTION: Sepsis is a public health problem due to its high prevalence and mortality. Mean platelet volume (MPV), a biomarker reported in routine blood counts, has been investigated and shows promise for determining fatal outcomes in septic patients. OBJECTIVE: Evaluate whether the mean platelet volume (MPV) and mean platelet volume-to-platelet count (MPV/P) ratio are predictors of clinical severity and mortality in patients with sepsis. METHODS: A prospective population cohort of 163 patients aged 18-97 years was recruited at the Intensive Care Unit of Pablo Arturo Hospital, Quito, Ecuador from 2017-2019 and followed up for 28 days. Patients were diagnosed with sepsis based on SEPSIS-3 septic shock criteria; in which the MPV and the MPV/P ratio were measured on days 1, 2, and 3. Sequential organ failure assessment (SOFA) score and presence of septic shock assessed clinical severity. Mortality on day 28 was considered the fatal outcome. RESULTS: The average age of the patients was 61,15 years (SD 20,94) and female sex was predominant. MPV cutoff points at days 1, 2 and 3 were >9,45fL, >8,95fL and >8, 85fL; and (MPV/P) ratio >8, 18, >4, 12 y >3, 95, respectively. MPV at days 2 (9,85fL) and 3 (8,55fL) and (MPV/P) ratio at days 1 (4,42), 2 (4,21), and 3 (8,55), were predictors of clinical severity assessed by septic shock, which reached significance in the ROC curves. MPV and (MPV/P) ratio were also predictors of clinical severity determined by SOFA at days 1, 2, and 3, where higher values were observed in non-survivors reaching significance in all categories. MPV and MPV/P ratio at days 1, 2 and 3 were independent predictor factors of mortality using Cox proportional hazards model (HR 2,31; 95% CI 1,36-3,94), (HR 2,11; 95% CI 1,17-3,82), (HR 2,13; 95% CI 1,07-4,21) and (HR 2,38; 95% CI 1,38-4,12), (HR 2,15; 95% CI 1,14-4,06), (HR 4,43; 95% CI, 1,72-11,37) respectively. CONCLUSIONS: MPV and the MPV/P ratio are predictors of clinical severity and mortality in sepsis. The MPV and its coefficient are indicators of the biological behavior of platelets in sepsis. They should be considered as a cost-effective and rapidly available tool that guides the treatment.

Emergence of immunosuppressive LOX-1+ PMN-MDSC in septic shock and severe COVID-19 patients with acute respiratory distress syndrome.

Myeloid-derived suppressor cells (MDSC) are a heterogeneous population of immature myeloid cells with immunosuppressive properties. In cancer patients, the expression of lectin-type oxidized LDL receptor 1 (LOX-1) on granulocytic MDSC identifies a subset of MDSC that retains the most potent immunosuppressive properties. The main objective of the present work was to explore the presence of LOX-1+ MDSC in bacterial and viral sepsis. To this end, whole blood LOX-1+ cells were phenotypically, morphologically, and functionally characterized. They were monitored in 39 coronavirus disease-19 (COVID-19, viral sepsis) and 48 septic shock (bacterial sepsis) patients longitudinally sampled five times over a 3 wk period in intensive care units (ICUs). The phenotype, morphology, and immunosuppressive functions of LOX-1+ cells demonstrated that they were polymorphonuclear MDSC. In patients, we observed the significant emergence of LOX-1+ MDSC in both groups. The peak of LOX-1+ MDSC was 1 wk delayed with respect to ICU admission. In COVID-19, their elevation was more pronounced in patients with acute respiratory distress syndrome. The persistence of these cells may contribute to long lasting immunosuppression leaving the patient unable to efficiently resolve infections.

Apelin-13 in septic shock: effective in supporting hemodynamics in sheep but compromised by enzymatic breakdown in patients.

Sepsis is a prevalent life-threatening condition related to a systemic infection, and with unresolved issues including refractory septic shock and organ failures. Endogenously released catecholamines are often inefficient to maintain blood pressure, and low reactivity to exogenous catecholamines with risk of sympathetic overstimulation is well documented in septic shock. In this context, apelinergics are efficient and safe inotrope and vasoregulator in rodents. However, their utility in a larger animal model as well as the limitations with regards to the enzymatic breakdown during sepsis, need to be investigated. The therapeutic potential and degradation of apelinergics in sepsis were tested experimentally and in a cohort of patients. (1) 36 sheep with or without fecal peritonitis-induced septic shock (a large animal experimental design aimed to mimic the human septic shock paradigm) were evaluated for hemodynamic and renal responsiveness to incremental doses of two dominant apelinergics: apelin-13 (APLN-13) or Elabela (ELA), and (2) 52 subjects (33 patients with sepsis/septic shock and 19 healthy volunteers) were investigated for early levels of endogenous apelinergics in the blood, the related enzymatic degradation profile, and data regarding sepsis outcome. APLN-13 was the only one apelinergic which efficiently improved hemodynamics in both healthy and septic sheep. Endogenous apelinergic levels early rose, and specific enzymatic breakdown activities potentially threatened endogenous apelin system reactivity and negatively impacted the outcome in human sepsis. Short-term exogenous APLN-13 infusion is helpful in stabilizing cardiorenal functions in ovine septic shock; however, this ability might be impaired by specific enzymatic systems triggered during the early time course of human sepsis. Strategies to improve resistance of APLN-13 to degradation and/or to overcome sepsis-induced enzymatic breakdown environment should guide future works.

Evaluation of albumin use in a community hospital setting: A retrospective study looking at appropriate use and prescribing patterns.

PURPOSE: Albumin has been shown to be safe and effective in clinical practice for a wide variety of indications. The purpose of this medication use evaluation is to quantify the use of albumin in the community hospital setting based on indication and prescribing department. METHODS: This study is a retrospective, single-center, chart review over a 6-month period of 186 patients aged 18 and older who were treated with IV human albumin 5% or 25% at a single 202-bed community hospital setting from February 1, 2020, to August 1, 2020. A chart review was completed for each patient and the data collected included date of albumin administration, the ordering provider, the specialty of the provider, the indication for albumin as stated in the order, patient notes, crystalloid therapy use prior to albumin, albumin strength, the presence of acute or chronic renal, hepatic or respiratory disorders, and lab values denoting renal and hepatic function. Appropriate albumin use was determined utilizing criteria which included FDA labeled indications, the Surviving Sepsis Campaign, and existing literature. RESULTS: A total of 186 patients received albumin 5% or 25% IV solution at least once during the study period. The study population was 52.2% female, and the average age was 68 years. Of the patients selected for the study, 23 (11.6%) had chronic hepatic disease, and 37 (18.7%) had chronic renal disease. The top indications for which albumin was administered were sepsis or septic shock (25.3%), hypotension or hypovolemia (19.4%), intra-dialytic hypotension (13.4%), fluid support in surgery (10.8%), and nephrosis or nephropathy (10.8%). The departments with highest albumin use during this study period were critical care (41%), nephrology (28%), and surgery (17%). Overall, albumin was used for an appropriate indication in 126 out of 186 patients (67.7%). CONCLUSION: We found that albumin was most utilized for sepsis and septic shock, hypovolemia and hypotension, and intradialytic hypotension in our community hospital setting and it was most frequently ordered by critical care, nephrology, and surgical departments. Further research could determine if this trend is seen in other community hospital settings.

Rho-Proteins and Downstream Pathways as Potential Targets in Sepsis and Septic Shock: What Have We Learned from Basic Research.

Sepsis and septic shock are associated with acute and sustained impairment in the function of the cardiovascular system, kidneys, lungs, liver, and brain, among others. Despite the significant advances in prevention and treatment, sepsis and septic shock sepsis remain global health problems with elevated mortality rates. Rho proteins can interact with a considerable number of targets, directly affecting cellular contractility, actin filament assembly and growing, cell motility and migration, cytoskeleton rearrangement, and actin polymerization, physiological functions that are intensively impaired during inflammatory conditions, such as the one that occurs in sepsis. In the last few decades, Rho proteins and their downstream pathways have been investigated in sepsis-associated experimental models. The most frequently used experimental design included the exposure to bacterial lipopolysaccharide (LPS), in both in vitro and in vivo approaches, but experiments using the cecal ligation and puncture (CLP) model of sepsis have also been performed. The findings described in this review indicate that Rho proteins, mainly RhoA and Rac1, are associated with the development of crucial sepsis-associated dysfunction in different systems and cells, including the endothelium, vessels, and heart. Notably, the data found in the literature suggest that either the inhibition or activation of Rho proteins and associated pathways might be desirable in sepsis and septic shock, accordingly with the cellular system evaluated. This review included the main findings, relevance, and limitations of the current knowledge connecting Rho proteins and sepsis-associated experimental models.

The Secretome Deregulations in a Rat Model of Endotoxemic Shock.

INTRODUCTION: Septic shock is a systemic inflammatory response syndrome associated with organ failures. Earlier clinical diagnosis would be of benefit to a decrease in the mortality rate. However, there is currently a lack of predictive biomarkers. The secretome is the set of proteins secreted by a cell, tissue, or organism at a given time and under certain conditions. The plasma secretome is easily accessible from biological fluids and represents a good opportunity to discover new biomarkers that can be studied with nontargeted "omic" strategies. AIMS: To identify relevant deregulated proteins (DEP) in the secretome of a rat endotoxemic shock model. METHODS: Endotoxemic shock was induced in rats by intravenous injection of lipopolysaccharides (LPS, S. enterica typhi, 0.5 mg/kg) and compared to controls (Ringer Lactate, iv). Under isoflurane anesthesia, carotid cannulation allowed mean arterial blood pressure (MAP) and heart rate (HR) monitoring and blood sampling at different time points (T0 and T50 or T0 and T90, with EDTA and protease inhibitor). Samples were prepared for large-scale tandem mass spectrometry (MS-MS) based on a label-free quantification to allow identification of the proteins deregulated upon endotoxemic conditions. A Gene Ontology (GO) analysis defined several clusters of biological processes (BP) in which the DEP are involved. RESULTS: Ninety minutes after shock induction, the LPS group presents a reduction in MAP (-45%, p < 0.05) and increased lactate levels (+27.5%, p < 0.05) compared to the control group. Proteomic analyses revealed 10 and 33 DEP in the LPS group, respectively, at 50 and 90 minutes after LPS injection. At these time points, GO-BP showed alterations in pathways involved in oxidative stress response and coagulation. CONCLUSION: This study proposes an approach to identify relevant DEP in septic shock and brings new insights into the understanding of the secretome adaptations upon sepsis.

Impact of plasma 5-hydroxyindoleacetic acid, a serotonin metabolite, on clinical outcome in septic shock, and its effect on vascular permeability.

Septic shock is characterized by dysregulated vascular permeability. We hypothesized that the vascular permeability of endothelial cells (ECs) would be regulated by serotonin via serotonin-Rho-associated kinase (ROCK) signaling. We aimed to determine the impact of 5-hydroxyindoleacetic acid (5-HIAA) on septic shock as a novel biomarker. Plasma 5-HIAA levels and disease severity indices were obtained from 47 patients with sepsis. The association between 5-HIAA levels and severity indices was analyzed. Permeability upon serotonin stimulation was determined using human pulmonary microvascular ECs. 5-HIAA were significantly higher in septic shock patients than in patients without shock or healthy controls (p = 0.004). These elevated levels were correlated with severity indexes (SOFA score [p < 0.001], APACHE II [p < 0.001], and PaO2:FiO2 [p = 0.02]), and longitudinally associated with worse clinical outcomes (mechanical ventilation duration [p = 0.009] and ICU duration [p = 0.01]). In the experiment, serotonin increased the permeability of ECs, which was inhibited by the ROCK inhibitor (p < 0.001). Serotonin increases vascular permeability of ECs via ROCK signaling. This suggests a novel mechanism by which serotonin disrupts endothelial barriers via ROCK signaling and causes the pathogenesis of septic shock with a vascular leak. Serotonin serves as a novel biomarker of vascular permeability.

3-Hydroxykynurenine Regulates Lipopolysaccharide-Stimulated IL-6 Production and Protects against Endotoxic Shock in Mice.

Despite advances in our understanding of endotoxic shock, novel therapeutic interventions that can reduce the burden of sepsis remain elusive. Current treatment options are limited, and it is only through refinements in the ways that we deliver supportive care that mortality has fallen over the years. In this study, the role of kynurenine 3-monooxygenase (KMO) in immune regulation was examined in LPS-induced endotoxemia using KMO-/- and KMO+/+ mice treated with the KMO inhibitor Ro61-8048. We showed that LPS-induced or cecal ligation and puncture-induced mortality and hepatic IL-6 production increased in the absence of KMO, possibly involving increased activating transcription factor 4 (ATF4) signaling in hepatic macrophages. Moreover, treatment of septic mice with 3-hydroxykynurenine reduced mortality rates and inflammatory responses regardless of the presence or absence of KMO. According to our results, the administration of 3-hydroxykynurenine as part of the treatment approach for sepsis or as an adjuvant therapy might reduce the overproduction of IL-6, which is responsible for severe endotoxemia, and ultimately improve the survival rates of patients with sepsis.

Alleviation of LPS-Induced Inflammation and Septic Shock by Lactiplantibacillus plantarum K8 Lysates.

We previously showed that Lactiplantibacillus plantarum K8 and its cell wall components have immunoregulatory effects. In this study, we demonstrate that pre-treatment of L. plantarum K8 lysates reduced LPS-induced TNF-α production in THP-1 cells by down-regulating the early signals of mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB). The down-regulation of signals may be caused by the induction of negative regulators involved in toll-like receptor (TLR)-mediated signaling. However, co-treatment with high concentrations of L. plantarum K8 lysates and lipopolysaccharide (LPS) activated the late signaling of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and NF-κB pathways and resulted in the induction of absent in melanoma 2 (AIM2) inflammasome-mediated interleukin (IL)-1ß secretion. Intraperitoneal injection of L. plantarum K8 lysates in LPS-induced endotoxin shock mice alleviated mortality and reduced serum tumor-necrosis factor (TNF)-α, IL-1ß, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels. In addition, the mRNA levels of TNF-α, IL-1ß, and IL-6 decreased in livers from mice injected with L. plantarum K8 followed by LPS. Hematoxylin and eosin (H&E) staining of the liver showed that the cell size was enlarged by LPS injection and slightly reduced by L. plantarum K8 lysate pre-injection followed by LPS injection. Macrophage infiltration of the liver also decreased in response to the combination injection compared with mice injected with only LPS. Taken together, our results show that although L. plantarum K8 lysates differentially regulated the production of LPS-induced inflammatory cytokines in THP-1 cells, the lysates inhibited overall inflammation in mice. Thus, this study suggests that L. plantarum K8 lysates could be developed as a substance that modulates immune homeostasis by regulating inflammation.

Tanshinones inhibit NLRP3 inflammasome activation by alleviating mitochondrial damage to protect against septic and gouty inflammation.

Tanshinones, the active ingredients derived from the roots of Salvia miltiorrhiza, have been widely used as traditional medicinal herbs for treating human diseases. Although tanshinones showed anti-inflammatory effects in many studies, large knowledge gaps remain regarding their underlying mechanisms. Here, we identified 15 tanshinones that suppressed the activation of NLRP3 inflammasome and studied their structure-activity relationships. Three tanshinones (tanshinone IIA, isocryptotanshinone, and dihydrotanshinone I) reduced mitochondrial reactive-oxygen species production in lipopolysaccharide (LPS)/nigericin-stimulated macrophages and correlated with altered mitochondrial membrane potentials, mitochondria complexes activities, and adenosine triphosphate and protonated-nicotinamide adenine dinucleotide production. The tanshinones may confer mitochondrial protection by promoting autophagy and the AMP-activated protein kinase pathway. Importantly, our findings demonstrate that dihydrotanshinone I improved the survival of mice with LPS shock and ameliorated inflammatory responses in septic and gouty animals. Our results suggest a potential pharmacological mechanism whereby tanshinones can effectively treat inflammatory diseases, such as septic and gouty inflammation.

Lipoxin A4 Restores Septic Renal Function via Blocking Crosstalk Between Inflammation and Premature Senescence.

Acute kidney injury (AKI) occurs in half of patients with septic shock, resulting in unacceptably high mortality. However, effective preventive treatments are still lacking. We hypothesized that pretreatment with lipoxin A4 (LXA4), known to promote inflammation resolution, may attenuate septic AKI via blocking crosstalk between inflammation and cellular senescence. In this study, rats developed AKI following cecal ligation and puncture (CLP), as evidenced by a dynamic increase in serum creatinine, blood urea nitrogen, urinary kidney injury molecule-1, neutrophil gelatinase-associated lipocalin, and pathological injury, accompanied by increased levels of inflammation (IL-6, TNF-α, and HMGB1) and tubular cell senescence. While, on the one hand, inhibition of senescence with rapamycin restored renal function and attenuated septic inflammatory response, on the other hand, LXA4 administration inhibited renal inflammation and tubular epithelial cell senescence after CLP. Ultimately, pretreatment with LXA4 significantly restored renal function and increased the survival rate of rats after CLP. Furthermore, LXA4 inhibited NF-κB-mediated inflammatory response and the p53/p21 senescence pathway in vivo and in vitro. However, the effect was reversed by PPAR-γ siRNA and antagonist. These results indicated that LXA4 exerted its renoprotective effects by blocking the crosstalk between inflammation and premature senescence in a PPAR-γ-dependent manner. Our findings also suggested that premature senescence plays a critical role in septic AKI and that inhibition of the crosstalk between inflammation and premature senescence may represent a new and major mechanism through which LXA4 attenuates septic AKI.

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.

Scoring Sepsis Severity in Mice.

A reliable scoring system that predicts the development of sepsis, septic shock, and death enables comparison of disease severity and treatment outcomes in animal models of sepsis. Mice are used in the majority of preclinical sepsis studies. We describe a murine sepsis score that evaluates seven clinical variables in an experimental mouse model of polymicrobial sepsis.

Targeted Inhibition of FTO Demethylase Protects Mice Against LPS-Induced Septic Shock by Suppressing NLRP3 Inflammasome.

Sepsis refers to the systemic inflammatory response syndrome caused by infection. It is a major clinical problem and cause of death for patients in intensive care units worldwide. The Fat mass and obesity-related protein (FTO) is the primary N6-methyladenosine demethylase. However, the role of FTO in the pathogenesis of inflammatory diseases remains unclear. We herein show that nanoparticle-mediated Fto-siRNA delivery or FTO inhibitor entacapone administration dramatically inhibited macrophage activation, reduced the tissue damage and improved survival in a mouse model of LPS-induced endotoxic shock. Importantly, ablation of FTO could inhibit NLRP3 inflammasome through FoxO1/NF-κB signaling in macrophages. In conclusion, FTO is involved in inflammatory response of LPS-induced septic shock and inhibition of FTO is promising for the treatment of septic shock.

Pralidoxime improves the hemodynamics and survival of rats with peritonitis-induced sepsis.

Several studies have suggested that sympathetic overstimulation causes deleterious effects in septic shock. A previous study suggested that pralidoxime exerted a pressor effect through a mechanism unrelated to the sympathetic nervous system; this effect was buffered by the vasodepressor action of pralidoxime mediated through sympathoinhibition. In this study, we explored the effects of pralidoxime on hemodynamics and survival in rats with peritonitis-induced sepsis. This study consisted of two sub-studies: survival and hemodynamic studies. In the survival study, 66 rats, which survived for 10 hours after cecal ligation and puncture (CLP), randomly received saline placebo, pralidoxime, or norepinephrine treatment and were monitored for up to 24 hours. In the hemodynamic study, 44 rats were randomly assigned to sham, CLP-saline placebo, CLP-pralidoxime, or CLP-norepinephrine groups, and hemodynamic measurements were performed using a conductance catheter placed in the left ventricle. In the survival study, 6 (27.2%), 15 (68.1%), and 5 (22.7%) animals survived the entire 24-hour monitoring period in the saline, pralidoxime, and norepinephrine groups, respectively (log-rank test P = 0.006). In the hemodynamic study, pralidoxime but not norepinephrine increased end-diastolic volume (P <0.001), stroke volume (P = 0.002), cardiac output (P = 0.003), mean arterial pressure (P = 0.041), and stroke work (P <0.001). The pressor effect of norepinephrine was short-lived, such that by 60 minutes after the initiation of norepinephrine infusion, it no longer had any significant effect on mean arterial pressure. In addition, norepinephrine significantly increased heart rate (P <0.001) and the ratio of arterial elastance to ventricular end-systolic elastance (P = 0.010), but pralidoxime did not. In conclusion, pralidoxime improved the hemodynamics and 24-hour survival rate in rats with peritonitis-induced sepsis, but norepinephrine did not.

Pin1 Promotes NLRP3 Inflammasome Activation by Phosphorylation of p38 MAPK Pathway in Septic Shock.

Pin1 is the only known peptidyl-prolyl cis-trans isomerase (PPIase) that can specifically recognize and isomerize the phosphorylated Serine/Threonine-Proline (pSer/Thr-Pro) motif, change the conformation of proteins through protein phosphorylation, thus regulate various cellular processes in the body. Pin1 plays an important role in cancer, Alzheimer's disease, and autoimmune diseases. However, the specific mechanism of Pin1 regulation in LPS-induced septic shock is unclear. Here, we found that lack of Pin1 reduced shock mortality and organ damage in mice, and NLRP3 inflammasome activation also was reduced in this process. We further confirmed that Pin1 can affect the expression of NLRP3, ASC, Caspase1, and this process can be regulated through the p38 MAPK pathway. We analyzed that p38 MAPK signaling pathway was highly expressed in septic shock and showed a positive correlation with Pin1 in the Gene Expression Omnibus database. We found that Pin1 could affect the phosphorylation of p38 MAPK, have no obvious difference in extracellular signal-regulated kinases (ERK) and Jun-amino-terminal kinase (JNK) signaling. We further found that Pin1 and p-p38 MAPK interacted, but not directly. In addition, Pin1 deficiency inhibited the cleavage of gasdermin D (GSDMD) and promoted the death of macrophages with LPS treatment, and reduced secretion of inflammatory cytokines including IL-1ß and IL-18. In general, our results suggest that Pin1 regulates the NLRP3 inflammasome activation by p38 MAPK signaling pathway in macrophages. Thus, Pin1 may be a potential target for the treatment of inflammatory diseases such as septic shock.