Rationale for Adjunctive Therapies for Pediatric Sepsis Induced Multiple Organ Failure

Luteolin transforms the polarity of bone marrow-derived macrophages to regulate the cytokine storm

Background

Macrophages are indispensable regulators of inflammatory responses. Macrophage polarisation and their secreted inflammatory factors have an association with the outcome of inflammation. Luteolin, a flavonoid abundant in plants, has anti-inflammatory activity, but whether luteolin can manipulate M1/M2 polarisation of bone marrow-derived macrophages (BMDMs) to suppress inflammation is still unclear. This study aimed to observe the effects of luteolin on the polarity of BMDMs derived from C57BL/6 mice and the expression of inflammatory factors, to explore the mechanism by which luteolin regulates the BMDM polarity.

Methods

M1-polarised BMDMs were induced by lipopolysaccharide (LPS) + interferon (IFN)-γ and M2-polarisation were stimulated with interleukin (IL)-4. BMDM morphology and phagocytosis were observed by laser confocal microscopy; levels of BMDM differentiation and cluster of differentiation (CD)11c or CD206 on the membrane surface were assessed by flow cytometry (FCM); mRNA and protein levels of M1/M2-type inflammatory factors were performed by qPCR and ELISA, respectively; and the expression of p-STAT1 and p-STAT6 protein pathways was detected by Western-blotting.

Results

The isolated mouse bone marrow cells were successfully differentiated into BMDMs, LPS + IFN-γ induced BMDM M1-phenotype polarisation, and IL-4 induced M2-phenotype polarisation. After M1-polarised BMDMs were treated with luteolin, the phagocytosis of M1-polarized BMDMs was reduced, and the M1-type pro-inflammatory factors including IL-6, tumour necrosis factor (TNF)-α, inducible nitric oxide synthase (iNOS), and CD86 were downregulated while the M2-type anti-inflammatory factors including IL-10, IL-13, found in inflammatory zone (FIZZ)1, Arginase (Arg)1 and CD206 were upregulated. Additionally, the expression of M1-type surface marker CD11c decreased. Nevertheless, the M2-type marker CD206 increased; and the levels of inflammatory signalling proteins phosphorylated signal transducer and activator of transcription (p-STAT)1 and p-STAT6 were attenuated and enhanced, respectively.

Conclusions

Our study suggests that luteolin may transform BMDM polarity through p-STAT1/6 to regulate the expression of inflammatory mediators, thereby inhibiting inflammation. Naturally occurring luteolin holds promise as an anti-inflammatory and immunomodulatory agent.

Inhibition of XBP1 Alleviates LPS-Induced Cardiomyocytes Injury by Upregulating XIAP through Suppressing the NF-κB Signaling Pathway

Cardiomyocytes injury caused by sepsis is a complication of common clinical critical illness and an important cause of high mortality in intensive care unit (ICU) patients. Therefore, lipopolysaccharide (LPS)-induced H9c2 cells were used to simulate the cardiomyocytes injury in vitro. The aim of this study was to investigate whether X-box binding protein 1 (XBP1) exacerbated LPS-induced cardiomyocytes injury by downregulating Xlinked inhibitor of apoptosis protein (XIAP) through activating the NF-κB signaling pathway. After transfection or LPS induction, XBP1 expression was detected by RT-qPCR analysis and Western blot analysis. The viability and apoptosis of H9c2 cells was detected by MTT assay and TUNEL assay. The protein expression related to apoptosis and NF-κB signaling pathway was detected by Western blot analysis. The inflammation and oxidative stress in H9c2 cells was evaluated by their commercial kits. Dual-luciferase reporter assay and chromatin immunoprecipitation (CHIP) assay were used to determine the combination of XBP1 and XIAP. As a result, LPS promoted the XBP1 expression in H9c2 cells. XBP1 was combined with XIAP. Inhibition of XBP1 increased viability, and inhibited apoptosis, inflammation, and oxidative stress of LPS-induced H9c2 cells by suppressing the NF-κB signaling pathway, which was partially reversed by the inhibition of XIAP. In conclusion, inhibition of XBP1 alleviates LPS-induced cardiomyocytes injury by upregulating XIAP through suppressing the NF-κB signaling pathway.

Clinical, laboratory features and prognosis of children receiving IgM-enriched immunoglobulin (3 days vs. 5 days) as adjuvant treatment for serious infectious disease in pediatric intensive care unit: a retrospective single-center experience (PIGMENT study)

Introduction

Although there are studies about sepsis treatment in different age groups, data on immunoglobulin-M (IgM)-enriched intravenous immunoglobulin use in pediatric intensive care units (PICUs) are limited. The aim of this study was to evaluate the clinical features and prognoses of children receiving IgM-enriched intravenous immunoglobulin to treat sepsis, septic shock, and multi-organ failure.

Method

We extracted data from the medical records of 254 children who received IgM-enriched intravenous immunoglobulin infusion (104 children for 3 days, 150 children for 5 days) in addition to standard treatment between 2010 and 2017.

Results

When the 5-day vs. 3-day IgM-enriched immunoglobulin treatments were compared, the mortality rate was shown to be lower in patients who received the longer duration of treatment (p < .001). Better outcomes were observed among children with septic shock (p < .01).

Conclusion

Our clinical work with 5-days IgM-enriched intravenous immunoglobulin may reveal a survival benefit of this treatment for children with septic shock.

A Multicenter Network Assessment of Three Inflammation Phenotypes in Pediatric Sepsis-Induced Multiple Organ Failure

OBJECTIVES

Ongoing adult sepsis clinical trials are assessing therapies that target three inflammation phenotypes including 1) immunoparalysis associated, 2) thrombotic microangiopathy driven thrombocytopenia associated, and 3) sequential liver failure associated multiple organ failure. These three phenotypes have not been assessed in the pediatric multicenter setting. We tested the hypothesis that these phenotypes are associated with increased macrophage activation syndrome and mortality in pediatric sepsis.

DESIGN

Prospective severe sepsis cohort study comparing children with multiple organ failure and any of these phenotypes to children with multiple organ failure without these phenotypes and children with single organ failure.

SETTING

Nine PICUs in the Eunice Kennedy Shriver National Institutes of Child Health and Human Development Collaborative Pediatric Critical Care Research Network.

PATIENTS

Children with severe sepsis and indwelling arterial or central venous catheters.

INTERVENTIONS

Clinical data collection and twice weekly blood sampling until PICU day 28 or discharge.

MEASUREMENTS AND MAIN RESULTS

Of 401 severe sepsis cases enrolled, 112 (28%) developed single organ failure (0% macrophage activation syndrome 0/112; < 1% mortality 1/112), whereas 289 (72%) developed multiple organ failure (9% macrophage activation syndrome 24/289; 15% mortality 43/289). Overall mortality was higher in children with multiple organ and the phenotypes (24/101 vs 20/300; relative risk, 3.56; 95% CI, 2.06-6.17). Compared to the 188 multiple organ failure patients without these inflammation phenotypes, the 101 multiple organ failure patients with these phenotypes had both increased macrophage activation syndrome (19% vs 3%; relative risk, 7.07; 95% CI, 2.72-18.38) and mortality (24% vs 10%; relative risk, 2.35; 95% CI, 1.35-4.08).

CONCLUSIONS

These three inflammation phenotypes were associated with increased macrophage activation syndrome and mortality in pediatric sepsis-induced multiple organ failure. This study provides an impetus and essential baseline data for planning multicenter clinical trials targeting these inflammation phenotypes in children.

Actualités sur le sepsis et le choc septique de l’enfant

L’incidence du sepsis de l’enfant augmente en réanimation pédiatrique. La définition du sepsis et du choc septique de l’enfant est amenée à évoluer à l’instar de celle du choc septique de l’adulte pour détecter les patients nécessitant une prise en charge urgente et spécialisée. La prise en charge d’un patient septique repose sur une oxygénothérapie, une expansion volémique au sérum salé isotonique, une antibiothérapie et un transfert dans un service de réanimation ou de surveillance continue pédiatrique. Le taux et la cinétique d’élimination du lactate plasmatique est un bon critère diagnostic et pronostic qui permet de guider la prise en charge. La présence de plusieurs défaillances d’organes ou une défaillance circulatoire aiguë signe le diagnostic de sepsis encore dit sévère, et leur persistance et/ou la non-correction de l’hypotension artérielle malgré un remplissage vasculaire d’au moins 40 ml/kg définit le choc septique chez l’enfant. Dans ce cas, la correction rapide de l’hypotension artérielle persistante repose sur la noradrénaline initiée sur une voie intraveineuse périphérique dans l’attente d’un accès veineux central. L’échographie cardiaque est un examen clé de l’évaluation hémodynamique du patient, pour guider la poursuite de l’expansion volémique ou détecter une cardiomyopathie septique. Des thérapeutiques additionnelles ont été proposées pour prendre en charge certains patients avec des défaillances d’organes particulières. L’immunomonitorage et la modulation sont un ensemble de techniques qui permettent la recherche et le traitement de certaines complications. La Surviving Sepsis Campaign a permis d’améliorer la prise en charge de ces patients par l’implémentation d’algorithmes de détection et de prise en charge du sepsis de l’enfant. Une révision pédiatrique de cette campagne est attendue prochainement.

Interventions for Pediatric Sepsis and Their Impact on Outcomes: A Brief Review

In the current era, pediatric sepsis remains a public health problem of significant prevalence and impact. With mortality rates practically unchanged over the years, this review hopes to briefly summarize the epidemiology and the current interventions for pediatric sepsis and point towards possible areas of improvement. Most pediatric studies of sepsis are either small, retrospective or observational. Given information technology spreading across country, and a stronger presence of clinical networks, development of multicenter prospective studies over the next decade should enable better treatments for pediatric sepsis, and improved outcomes.

Thrombocytopenia-associated multiple-organ failure (TAMOF): recognition and management

Thrombocytopenia-associated multiple-organ failure (TAMOF) is an increasingly fatal phenomenon that may be associated with sepsis. TAMOF results from immune dysregulation and impaired activity of A Disintegrin And Metalloproteinase with ThromboSpondin type 1 motif, member 13. Early recognition of this premorbid condition and specific management results in a significantly improved outcome. Herein, we report the presentation and management of a 2-year-old child with TAMOF who was successfully treated with plasma exchange and recovered without long-term sequelae.

Tetramethylpyrazine attenuates lipopolysaccharide-induced cardiomyocyte injury via improving mitochondrial function mediated by 14-3-3γ

Lipopolysaccharide (LPS) is one of the many reasons that can cause myocardial injury. Our previous works have demonstrated that 14-3-3γ could protect myocardium against LPS-induced injury. Tetramethylpyrazine (TMP), an alkaloid found in Chinese herbs, exerts myocardial protection in many ways with multiple targets. We hypothesized that the cardioprotection of TMP against LPS-induced injury is attributed to upregulation of 14-3-3γ and improvement of mitochondrial function. To test the hypothesis, we investigated the effects of TMP on LPS-induced injury to cardiomyocytes by determining cell viability, LDH and caspase-3 activities, reactive oxygen species and MMP levels, mPTP openness, and apoptosis rate. The expression of 14-3-3γ and Bcl-2, and the phosphorylation of Bad (S112) were examined by Western blot. LPS-induced injury to cardiomyocytes was attenuated by TMP via upregulating expression of 14-3-3γ, and Bcl-2 on mitochondria, activating Bad (S112) phosphorylation, increasing cell viability and MMP levels, decreasing LDH and caspase-3 activity, reactive oxygen species generation, mPTP opening and apoptosis rate. However, the cardioprotection of TMP was attenuated by pAD/14-3-3γ-shRNA, an adenovirus that knocked down intracellular 14-3-3γ expression. In conclusion, the cardioprotection of TMP against LPS-induced injury was through up-regulating the expression of 14-3-3γ, promoting the translocation of Bcl-2 to mitochondria, and improving the function of mitochondria.