Markers of Endothelial Dysfunction and Cytokines in High-Risk Pediatric Patients with Severe Sepsis

Derivation, Validation, and Clinical Relevance of a Pediatric Sepsis Phenotype With Persistent Hypoxemia, Encephalopathy, and Shock

OBJECTIVES

Untangling the heterogeneity of sepsis in children and identifying clinically relevant phenotypes could lead to the development of targeted therapies. Our aim was to analyze the organ dysfunction trajectories of children with sepsis-associated multiple organ dysfunction syndrome (MODS) to identify reproducible and clinically relevant sepsis phenotypes and determine if they are associated with heterogeneity of treatment effect (HTE) to common therapies.

DESIGN

Multicenter observational cohort study.

SETTING

Thirteen PICUs in the United States.

PATIENTS

Patients admitted with suspected infections to the PICU between 2012 and 2018.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We used subgraph-augmented nonnegative matrix factorization to identify candidate trajectory-based phenotypes based on the type, severity, and progression of organ dysfunction in the first 72 hours. We analyzed the candidate phenotypes to determine reproducibility as well as prognostic, therapeutic, and biological relevance. Overall, 38,732 children had suspected infection, of which 15,246 (39.4%) had sepsis-associated MODS with an in-hospital mortality of 10.1%. We identified an organ dysfunction trajectory-based phenotype (which we termed persistent hypoxemia, encephalopathy, and shock) that was highly reproducible, had features of systemic inflammation and coagulopathy, and was independently associated with higher mortality. In a propensity score-matched analysis, patients with persistent hypoxemia, encephalopathy, and shock phenotype appeared to have HTE and benefit from adjuvant therapy with hydrocortisone and albumin. When compared with other high-risk clinical syndromes, the persistent hypoxemia, encephalopathy, and shock phenotype only overlapped with 50%-60% of patients with septic shock, moderate-to-severe pediatric acute respiratory distress syndrome, or those in the top tier of organ dysfunction burden, suggesting that it represents a nonsynonymous clinical phenotype of sepsis-associated MODS.

CONCLUSIONS

We derived and validated the persistent hypoxemia, encephalopathy, and shock phenotype, which is highly reproducible, clinically relevant, and associated with HTE to common adjuvant therapies in children with sepsis.

Integrated PERSEVERE and endothelial biomarker risk model predicts death and persistent MODS in pediatric septic shock: a secondary analysis of a prospective observational study

Background

Multiple organ dysfunction syndrome (MODS) is a critical driver of sepsis morbidity and mortality in children. Early identification of those at risk of death and persistent organ dysfunctions is necessary to enrich patients for future trials of sepsis therapeutics. Here, we sought to integrate endothelial and PERSEVERE biomarkers to estimate the composite risk of death or organ dysfunctions on day 7 of septic shock.

Methods

We measured endothelial dysfunction markers from day 1 serum among those with existing PERSEVERE data. TreeNet® classification model was derived incorporating 22 clinical and biological variables to estimate risk. Based on relative variable importance, a simplified 6-biomarker model was developed thereafter.

Results

Among 502 patients, 49 patients died before day 7 and 124 patients had persistence of MODS on day 7 of septic shock. Area under the receiver operator characteristic curve (AUROC) for the newly derived PERSEVEREnce model to predict death or day 7 MODS was 0.93 (0.91–0.95) with a summary AUROC of 0.80 (0.76–0.84) upon tenfold cross-validation. The simplified model, based on IL-8, HSP70, ICAM-1, Angpt2/Tie2, Angpt2/Angpt1, and Thrombomodulin, performed similarly. Interaction between variables—ICAM-1 with IL-8 and Thrombomodulin with Angpt2/Angpt1—contributed to the models’ predictive capabilities. Model performance varied when estimating risk of individual organ dysfunctions with AUROCS ranging from 0.91 to 0.97 and 0.68 to 0.89 in training and test sets, respectively.

Conclusions

The newly derived PERSEVEREnce biomarker model reliably estimates risk of death or persistent organ dysfunctions on day 7 of septic shock. If validated, this tool can be used for prognostic enrichment in future pediatric trials of sepsis therapeutics.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-04070-5.

Mechanosensitive Channel PIEZO1 Senses Shear Force to Induce KLF2/4 Expression via CaMKII/MEKK3/ERK5 Axis in Endothelial Cells

Shear stress exerted by the blood stream modulates endothelial functions through altering gene expression. KLF2 and KLF4, the mechanosensitive transcription factors, are promoted by laminar flow to maintain endothelial homeostasis. However, how the expression of KLF2/4 is regulated by shear stress is poorly understood. Here, we showed that the activation of PIEZO1 upregulates the expression of KLF2/4 in endothelial cells. Mice with endothelial-specific deletion of Piezo1 exhibit reduced KLF2/4 expression in thoracic aorta and pulmonary vascular endothelial cells. Mechanistically, shear stress activates PIEZO1, which results in a calcium influx and subsequently activation of CaMKII. CaMKII interacts with and activates MEKK3 to promote MEKK3/MEK5/ERK5 signaling and ultimately induce the transcription of KLF2/4. Our data provide the molecular insight into how endothelial cells sense and convert mechanical stimuli into a biological response to promote KLF2/4 expression for the maintenance of endothelial function and homeostasis.

A new approach to sepsis treatment by rasagiline: a molecular, biochemical and histopathological study

AIM

We aimed to investigate the effects of rasagiline on acute lung injury that develops in the sepsis model induced with the cecal ligation and puncture in rats.

MAIN METHODS

The rats were separated into the following six groups, Group 1: Sham, Group 2: Sham + Rasagiline 4 mg/kg, Group 3: Sepsis, Group 4: Sepsis + Rasagiline 1 mg/kg, Group 5: Sepsis + Rasagiline 2 mg/kg, Group 6: Sepsis + Rasagiline 4 mg/kg. A total of four holes were opened with a 16-gauge needle through the cecum distal to the point of ligation.

KEY FINDINGS

Rasagiline treatment increased glutathione level and superoxide dismutase activity while decreased the malondialdehyde level after the sepsis. There was a statistically significant improvement in the doses of 2 mg/kg and 4 mg/kg. Rasagiline also increased Tnf-α, IL1β, IL6, NF-κβand HMGB1 gene expressions in dose-dependent at 2 mg/kg and 4 mg/kg doses. In increased doses, rasagiline prevent the development of edema, the formation of inflammation, and hemorrhage.

SIGNIFICANCE

Rasagiline exerts both antioxidant and anti-inflammatory effects on the cecal ligation and puncture induced acute lung injury in rats.

Von Willebrand factor, its cleaving protease (ADAMTS13), and inflammation in young adults: The African-PREDICT study

BACKGROUND

The role of inflammation in the early development of vascular dysfunction remains complex. Interleukin-6 (IL-6) and C-reactive protein (CRP) can cause an acute imbalance in the von Willebrand factor (vWF)-ADAMTS13 interaction, indicating a possible link between markers of haemostasis and low-grade inflammation. To better understand these inter-relationships in the early phases of disease development, we investigated whether vWF and ADAMTS13 associate with the pro-inflammatory markers, IL-6 and CRP in healthy young adults. We considered the role of blood types, sex and race on these relationships.

METHODS

In healthy black and white men and women (n = 1113; 24 ± 5 years; no previous diagnosis or medication use for chronic diseases) we analysed von Willebrand factor antigen (vWF_ag), ADAMTS13, IL-6 and CRP, and grouped blood types as non-O (A, B and AB) and O. Covariates included socioeconomic status, age, estimated glomerular filtration rate, 24-hour systolic blood pressure, waist circumference, glucose, total cholesterol, platelet count, γ-glutamyl transferase and total energy expenditure.

RESULTS

In the total group, vWF_ag was highest in the third tertile of both IL-6 and CRP (p ≤ 0.014), while ADAMTS13 was lowest in the third compared to the first IL-6 tertile (p = 0.006). In multivariate regression, vWF_ag associated positively with IL-6 (Adj R² = 0.169; β = 0.123; p = 0.001) and CRP (Adj R² = 0.163; β=0.094; p = 0.019) in the total group, in the O blood group (all p ≤ 0.051) and white men (all p ≤ 0.035). ADAMTS13 associated negatively with IL-6 (Adj R² = 0.053; β = -0.154; p = 0.015) and CRP (Adj R² = 0.055; β = -0.177; p = 0.009), only in the O blood group.

CONCLUSIONS

Markers of haemostasis associated independently with low-grade inflammation in the O type blood group and white men. An interplay between the haemostatic and inflammatory systems may already exist in young healthy adults and is dependent on blood groups, sex and race. This extends our understanding on the role of inflammation in the early development of vascular dysfunction prior to cardiovascular compromise.

Cytokine Levels in Critically Ill Children With Severe Sepsis and Their Relation With the Severity of Illness and Mortality

OBJECTIVE

To study the baseline cytokine levels and their relation with the severity of illness and mortality in critically ill children with severe sepsis.

DESIGN

Subgroup analysis of a randomized, double-blind, placebo-controlled trial.

SETTING

Pediatric intensive care unit of a tertiary level teaching hospital in India.

PATIENTS

Fifty children with severe sepsis aged 3 months to 12 years.

MATERIAL AND METHODS

Blood was collected at admission for estimation of pro-inflammatory (interleukin 6 [IL-6], IL-12p70, IL-17, and tumor necrotic factor α [TNF-α]) and anti-inflammatory (IL-10 and transforming growth factor β1 [TGF-β1]) cytokines.

PRIMARY OUTCOME

To find out correlation between cytokine levels and severity of illness scores (Pediatric Risk of Mortality [PRISM] III score, Sequential Organ Failure Assessment [SOFA], and Vasoactive-Inotropic Score [VIS]).

SECONDARY OUTCOMES

To compare cytokine levels among survivors and nonsurvivors.

RESULTS

Baseline pro-inflammatory cytokine levels (median [interquartile range]) were IL-6: 189 (35-285) pg/mL, IL-12p: 48 (28-98) pg/mL, IL-17: 240 (133-345) pg/mL, and TNF-α: 296 (198-430) pg/mL; anti-inflammatory cytokine levels were IL-10: 185 (62-395) pg/mL and TGF-β1: 204 (92-290) ng/mL. Pro-inflammatory cytokines showed positive correlation with PRISM III score: IL-6 (Spearman correlation coefficient, ρ = 0.273, P = .06), IL-12 (ρ = 0.367, P = .01), IL-17 (ρ = 0.197, P = .17), and TNF-α (ρ = 0.284, P = .05), and anti-inflammatory cytokines showed negative correlation: IL-10 (ρ = -0.257, P = .09) and TGF-β (ρ = -0.238, P = .11). Both SOFA and VIS also showed weak positive correlation with IL-12 (ρ = 0.32, P = .03 and ρ = 0.31, P = .03, respectively). Among nonsurvivors (n = 5), the levels of all the measured pro-inflammatory cytokines were significantly higher as compared to survivors, IL-6: 359 (251-499) pg/mL versus 157 (97-223) pg/mL, P < .0001, IL-12p70: 167 (133-196) pg/mL versus 66 (30-100) pg/mL, P < .0001, IL-17: 400 (333-563) pg/mL versus 237 (122-318) pg/mL, P = .009, and TNF-α: 409 (355-503) pg/mL versus 330 (198-415) pg/mL, P = .002, respectively.

CONCLUSION

In critically ill children with severe sepsis, pro-inflammatory cytokines (especially IL-12p70) showed a weak positive correlation with severity of illness and were significantly higher among nonsurvivors.

KLF4/Ch25h axis activated by metformin suppresses EndoMT in human umbilical vein endothelial cells

Metformin, an anti-hyperglycemia drug, protected endothelial cells (ECs) from dysfunction while high glucose (HG) caused endothelial dysfunction. Previously, we found that metformin suppressed endothelial-to-mesenchymal transition (EndoMT), a cellular process that promoted endothelial dysfunction. However, the involved mechanism is still unclear. In this study, we found that metformin increased the expression of krüppel-like factor 4 (KLF4) and cholesterol-25-hydroxylase (Ch25h) while HG decreased the expression of KLF4 and Ch25h. In addition, HG promoted EndoMT indicting by the decrease of endothelial maker genes and increase of mesenchymal maker genes. Furthermore, RNA sequence (RNA-seq) data showed that KLF4 suppressed EndoMT. Moreover, we proved that metformin increased Ch25h expression through not only KLF4 but also epigenetic modification including DNA methylation and active histone modification. Lastly, we proved that Ch25h/25 hydroxycholesterol (25 HC)/Liver X receptor α (LXRα) suppressed EndoMT. Altogether, our study demonstrated that KLF4/Ch25h/axis activated by metformin suppressed EndoMT. Therefore, KLF4/Ch25h/axis may be a new potential therapeutic target for endothelial dysfunction diseases.