Prognostic value of blood inflammatory parameters for predicting mortality in neonates with sepsis.

BACKGROUND: Neonatal sepsis is a major cause of morbidity and mortality in neonates. The diagnosis of neonatal sepsis has been widely explored using blood inflammatory parameters. However, few researches have focused on the predictive significance of blood inflammation parameters for predicting mortality. This study aimed to evaluate the prognostic value of blood inflammatory parameters, including white blood cell (WBC), neutrophil, lymphocyte, monocyte, platelet and C-reactive protein (CRP) for predicting mortality in neonates with sepsis. METHODS: Neonates with culture-proven sepsis were enrolled in this study. The clinical characteristics and levels of white blood cell, neutrophil, lymphocyte, monocyte, platelet and CRP were recorded. The receiver-operating characteristic (ROC) curve was applied to calculate the area under the curve (AUC) and determine the optimal cutoff values. Multivariable Cox regression model was used to evaluate the independent prognostic significance of variables. Kaplan-Meier curve was used to assess survival. RESULTS: A total of 188 neonates with culture-proven sepsis were included for analysis. The 7-day mortality rate was 11.2 % (21/188) and the 28-day mortality rate was 13.8 % (26/188). The levels of white blood cell, neutrophil, monocyte and platelet in non-survivors were lower than those in survivors (P < 0.05). Platelet yielded higher AUC values than other parameters for predicting mortality with the best cutoff value of 132 × 109/L, followed by WBC with the optimal cutoff value of 6.15 × 109/L. Multivariable Cox regression analysis showed platelet and WBC were independent prognostic factors for predicting mortality. Low platelet group showed lower survival according to Kaplan-Meier method. CONCLUSIONS: In conclusion, the levels of platelet and WBC on the day of sepsis onset are valuable indicators for predicting mortality in neonates with sepsis.

B-Cell-Activating Factor Contributes to Elevation of the Content of Regulatory B Cells in Neonatal Sepsis.

We studied the role of B cell-activating factor (BAFF) in PI3K/AKT/mTOR signaling pathway in promoting proliferation and maintaining survival of regulatory B lymphocytes (Breg) in newborns with sepsis. The peripheral blood samples were collected from preterm neonates (n=40) diagnosed with sepsis on the day of diagnosis and on days 7, 14, and 21 after diagnosis, as well as from the matched preterm neonates without sepsis (n=40; control group). The peripheral blood mononuclear cells and B cells were isolated, cultured, and stimulated with LPS and immunostimulant CpG-oligodeoxynucleotide (CpG-ODN). Proliferation and differentiation of B-cells into CD19+CD24hiCD38hi Breg cells and the role of the PI3K/AKT/mTOR signaling pathway in these processes were studied by flow cytometry, real-time quantitative reverse transcription PCR (qRT-PCR), and Western blotting. BAFF levels in the peripheral blood of neonates with sepsis were significantly increased at one week after diagnosis in parallel with increasing trend of expression of BAFF receptor. When applied with LPS and CpG-ODN, BAFF promoted differentiation of B cells into CD19+CD24hiCD38hi Breg cells. Phosphorylation of 4E-BP1 factor and 70S6K kinase located downstream in PI3K/AKT/mTOR signaling pathway was significantly up-regulated when stimulated with BAFF in combination with LPS and CpG-ODN. Thus, increased level of BAFF activates PI3K/AKT/mTOR signaling pathway and induces in vitro differentiation of peripheral blood B cells into CD19+CD24hiCD38hi Breg cells.

A20 and the noncanonical NF-κB pathway are key regulators of neutrophil recruitment during fetal ontogeny.

Newborns are at high risk of developing neonatal sepsis, particularly if born prematurely. This has been linked to divergent requirements the immune system has to fulfill during intrauterine compared with extrauterine life. By transcriptomic analysis of fetal and adult neutrophils, we shed new light on the molecular mechanisms of neutrophil maturation and functional adaption during fetal ontogeny. We identified an accumulation of differentially regulated genes within the noncanonical NF-κB signaling pathway accompanied by constitutive nuclear localization of RelB and increased surface expression of TNF receptor type II in fetal neutrophils, as well as elevated levels of lymphotoxin α in fetal serum. Furthermore, we found strong upregulation of the negative inflammatory regulator A20 (Tnfaip3) in fetal neutrophils, which was accompanied by pronounced downregulation of the canonical NF-κB pathway. Functionally, overexpressing A20 in Hoxb8 cells led to reduced adhesion of these neutrophil-like cells in a flow chamber system. Conversely, mice with a neutrophil-specific A20 deletion displayed increased inflammation in vivo. Taken together, we have uncovered constitutive activation of the noncanonical NF-κB pathway with concomitant upregulation of A20 in fetal neutrophils. This offers perfect adaption of neutrophil function during intrauterine fetal life but also restricts appropriate immune responses particularly in prematurely born infants.

Nucleotide receptors mediate protection against neonatal sepsis and meningitis caused by alpha-hemolysin expressing Escherichia coli K1.

Neonatal meningitis-associated Escherichia coli (NMEC) is among the leading causes of bacterial meningitis and sepsis in newborn infants. Several virulence factors have been identified as common among NMEC, and have been shown to play an important role in the development of bacteremia and/or meningitis. However, there is significant variability in virulence factor expression between NMEC isolates, and relatively little research has been done to assess the impact of variable virulence factor expression on immune cell activation and the outcome of infection. Here, we investigated the role of NMEC strain-dependent P2X receptor (P2XR) signaling on the outcome of infection in neonatal mice. We found that alpha-hemolysin (HlyA)-expressing NMEC (HlyA+ ) induced robust P2XR-dependent macrophage cell death in vitro, while HlyA- NMEC did not. P2XR-dependent cell death was inflammasome independent, suggesting an uncoupling of P2XR and inflammasome activation in the context of NMEC infection. In vivo inhibition of P2XRs was associated with increased mortality in neonatal mice infected with HlyA+ NMEC, but had no effect on the survival of neonatal mice infected with HlyA- NMEC. Furthermore, we found that P2XR-dependent protection against HlyA+ NMEC in vivo required macrophages, but not neutrophils or NLRP3. Taken together, these data suggest that HlyA+ NMEC activates P2XRs which in turn confers macrophage-dependent protection against infection in neonates. In addition, our findings indicate that strain-dependent virulence factor expression should be taken into account when studying the immune response to NMEC.

Serum miR-34a-5p and miR-199a-3p as new biomarkers of neonatal sepsis.

BACKGROUND: Neonatal sepsis is a serious condition. Recent clinical studies have indicated that microRNAs (miRNAs) are key players in the pathogenesis of sepsis, which could be used as biomarkers for this condition. PATIENTS AND METHODS: A total of 90 neonates with sepsis and 90 healthy neonates were enrolled in this study. qRT-PCR was performed to measure the expression levels of serum miR-34a-5p and miR-199a-3p. RESULTS: miR-34a-5p and miR-199a-3p serum levels were significantly reduced in neonates with sepsis compared with those in healthy neonates (P = 0.006 and P = 0.001, respectively). Significant correlations of miR-34a-5p and miR-199a-3p with each of TLC, RDW, RBS, and C-reactive protein (CRP) as well as SNAPII were observed, indicating their associations with the severity of neonatal sepsis. CONCLUSION: miR-34a-5p and miR-199a-3p may be useful as novel biomarkers in neonatal sepsis and may provide a new direction for its treatment.

Diagnosis of neonatal sepsis: the past, present and future.

Sepsis remains a significant cause of neonatal mortality and morbidity, especially in low- and middle-income countries. Neonatal sepsis presents with nonspecific signs and symptoms that necessitate tests to confirm the diagnosis. Early and accurate diagnosis of infection will improve clinical outcomes and decrease the overuse of antibiotics. Current diagnostic methods rely on conventional culture methods, which is time-consuming, and may delay critical therapeutic decisions. Nonculture-based techniques including molecular methods and mass spectrometry may overcome some of the limitations seen with culture-based techniques. Biomarkers including hematological indices, cell adhesion molecules, interleukins, and acute-phase reactants have been used for the diagnosis of neonatal sepsis. In this review, we examine past and current microbiological techniques, hematological indices, and inflammatory biomarkers that may aid sepsis diagnosis. The search for an ideal biomarker that has adequate diagnostic accuracy early in sepsis is still ongoing. We discuss promising strategies for the future that are being developed and tested that may help us diagnose sepsis early and improve clinical outcomes. IMPACT: Reviews the clinical relevance of currently available diagnostic tests for sepsis. Summarizes the diagnostic accuracy of novel biomarkers for neonatal sepsis. Outlines future strategies including the use of omics technology, personalized medicine, and point of care tests.

Targeting the Toll-like receptor pathway as a therapeutic strategy for neonatal infection.

Toll-like receptors (TLRs) are crucial transmembrane receptors that form part of the innate immune response. They play a role in the recognition of various microorganisms and their elimination from the host. TLRs have been proposed as vital immunomodulators in the regulation of multiple neonatal stressors that extend beyond infection such as oxidative stress and pain. The immune system is immature at birth and takes some time to become fully established. As such, babies are especially vulnerable to sepsis at this early stage of life. Findings suggest a gestational age-dependent increase in TLR expression. TLRs engage with accessory and adaptor proteins to facilitate recognition of pathogens and their activation of the receptor. TLRs are generally upregulated during infection and promote the transcription and release of proinflammatory cytokines. Several studies report that TLRs are epigenetically modulated by chromatin changes and promoter methylation upon bacterial infection that have long-term influences on immune responses. TLR activation is reported to modulate cardiorespiratory responses during infection and may play a key role in driving homeostatic instability observed during sepsis. Although complex, TLR signaling and downstream pathways are potential therapeutic targets in the treatment of neonatal diseases. By reviewing the expression and function of key Toll-like receptors, we aim to provide an important framework to understand the functional role of these receptors in response to stress and infection in premature infants.

Berberine Attenuates Neonatal Sepsis in Mice By Inhibiting FOXA1 and NF-κB Signal Transduction Via the Induction of MiR-132-3p.

Neonatal sepsis (NS) is a severe syndrome in newborns that is induced by infections, and the initiation and development of NS are closely associated with the function of miRs. In the current study, the effects of berberine, which is a functional component in traditional Chinese medicine (TCM), against NS were assessed by focusing on the interaction of berberine with miR-132-3p-mediated signaling. An NS model was induced using cecal slurry (CS) in vivo and LPS in vitro, and berberine treatment was applies. The changes in survival rate, intestinal structure, and systemic inflammation in mice and the viability, apoptosis, and inflammatory response in intestinal cells were measured. At the molecular level, miR-132-3p levels and the activities of the FOXA1 and NF-κB pathways were analyzed. The data showed that berberine increased the survival rates of CS-induced mice. The intestinal injuries induced by CS were also attenuated by berberine, which was associated with inhibition of the production of systemic IL-6, IL-1ß, and TNF-α. At the molecular level, the expression of miR-132-3p was upregulated, suppressing the expression of FOXA1, p-IκBα, and p65 while inducing the expression of IκBα. The effects of berberine on NS-induced impairments were blocked by the injection of the miR-132-3p antagomir, which exacerbated intestinal injuries, induced systemic inflammation, and reactivated the FOXA1 and NF-κB pathways. The findings in the in vivo model were validated with in vitro assays. Collectively, the findings outlined in the current study indicated that berberine had solid protective effects against NS-induced symptoms in newborn mice, and the effects depended on the upregulation of miR-132-3p.

Up-regulation of BTLA expression in myeloid dendritic cells associated with the treatment outcome of neonatal sepsis.

Dentritic cells (DCs) dysfunction has been verified detrimental for sepsis and B and T lymphocyte attenuator (BTLA) is an immune-regulatory receptor shown to be associated with DCs dysfunction. However, the role of BTLA expression in myeloid DCs (mDCs) in neonatal sepsis is unknown. In the current study, we found BTLA-expressing mDCs were elevated in neonates with sepsis and the BTLA expression level in mDCs was positively correlated to the severity of sepsis. The presence of BTLA negatively regulated the phagocytosis capacity and bactericidal ability of mDCs as well as the maturation markers expression of mDCs. Our data also showed BTLA+mDCs shifted into an anti-inflammatory phenotype with decreased expression of IL-6, TNF-α and IL-12, but increased IL-10. in addition, we found BTLA expression indeedly altered the mDCs allo-stimulatory capacity. Therefore, BTLA expression in mDCs could be a useful predictive marker for neonatal sepsis and targeting BTLA expression in mDCs may be a new therapeutic strategy.

Survival and Pulmonary Injury After Neonatal Sepsis: PD1/PDL1's Contributions to Mouse and Human Immunopathology.

Morbidity and mortality associated with neonatal sepsis remains a healthcare crisis. PD1-/- neonatal mice endured experimental sepsis, in the form of cecal slurry (CS), and showed improved rates of survival compared to wildtype (WT) counterparts. End-organ injury, particularly of the lung, contributes to the devastation set forth by neonatal sepsis. PDL1-/- neonatal mice, in contrast to PD1-/- neonatal mice did not have a significant improvement in survival after CS. Because of this, we focused subsequent studies on the impact of PD1 gene deficiency on lung injury. Here, we observed that at 24 h post-CS (but not at 4 or 12 h) there was a marked increase in pulmonary edema (PE), neutrophil influx, myeloperoxidase (MPO) levels, and cytokine expression sham (Sh) WT mice. Regarding pulmonary endothelial cell (EC) adhesion molecule expression, we observed that Zona occludens-1 (ZO-1) within the cell shifted from a membranous location to a peri-nuclear location after CS in WT murine cultured ECs at 24hrs, but remained membranous among PD1-/- lungs. To expand the scope of this inquiry, we investigated human neonatal lung tissue. We observed that the lungs of human newborns exposed to intrauterine infection had significantly higher numbers of PD1+ cells compared to specimens who died from non-infectious causes. Together, these data suggest that PD1/PDL1, a pathway typically thought to govern adaptive immune processes in adult animals, can modulate the largely innate neonatal pulmonary immune response to experimental septic insult. The potential future significance of this area of study includes that PD1/PDL1 checkpoint proteins may be viable therapeutic targets in the septic neonate.

Utility of volatile organic compounds as a diagnostic tool in preterm infants.

BACKGROUND: Volatile organic compounds (VOCs) are hydrocarbons that originate within different healthy and diseased tissues. VOCs can be secreted into the circulation and then excreted in the urine and faeces. In the lungs, VOCs are locally produced and can be detected in exhaled breath. VOCs can be identified using non-invasive techniques, which make their use in preterm infants safe and desirable. METHODS: A systematic search of the literature in PubMed, Embase and Web of Science was conducted looking for VOCs techniques and diagnostic performance in preterm infants. A total of 50 articles identified with only seven papers were included in the final analysis in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). RESULTS: VOCs could diagnose necrotising enterocolitis up to 4 days before a clinical diagnosis; for late onset sepsis, up to 3 days before; and for bronchopulmonary dysplasia, up to 2 weeks before. In addition to these diagnostic uses, VOCs analysis could also distinguish breastfed from formula-fed preterm neonates in the first month of life. CONCLUSION: VOCs analysis is a non-invasive tool that makes the use in preterm infants of preference. VOCs analytic techniques require more research and consensus between researchers to overcome their limitations. IMPACT: Volatile organic compounds are hydrocarbons that can separate between healthy and diseased states in preterm infants. Biomarker panels developed from volatile organic compounds are potential diagnostic tools. The non-invasive nature of acquiring volatile organic compounds markers make it desirable in the paediatric patients. Research into exact chemical components of the volatile organic compounds can inform about the pathophysiology of disease in preterm infants. More robust longitudinal studies with repeated experiments are required before volatile organic compounds can be applied in clinical practice.

Human milk oligosaccharides and their association with late-onset neonatal sepsis in Peruvian very-low-birth-weight infants.

BACKGROUND: Oligosaccharides are the third most abundant component in human milk. They are a potential protective agent against neonatal sepsis. OBJECTIVES: We aimed to explore the association between human milk oligosaccharides (HMOs) and late-onset sepsis in very-low-birth-weight infants, and to describe the composition and characteristics of HMOs in Peruvian mothers of these infants. METHODS: This is a secondary data analysis of a randomized clinical trial. We conducted a retrospective cohort study of mothers and their very-low-birth-weight (<1500 g) infants with ≥1 milk sample and follow-up data for >30 d. HMOs were measured by high performance liquid chromatography (HPLC). We used factor analysis and the Mantel-Cox test to explore the association between HMOs and late-onset neonatal sepsis. RESULTS: We included 153 mother-infant pairs and 208 milk samples. Overall, the frequency of the secretor phenotype was 93%. Secretors and nonsecretors were defined by the presence and near-absence of α1-2-fucosylated HMOs, respectively. The most abundant oligosaccharides were 2'-fucosyllactose, lacto-N-fucopentaose (LNFP) I, and difucosyllacto-N-tetraose in secretors and lacto-N-tetraose and LNFP II in nonsecretors. Secretors had higher amounts of total oligosaccharides than nonsecretors (11.45 g/L; IQR: 0.773 g/L compared with 8.04 g/L; IQR: 0.449 g/L). Mature milk samples were more diverse in terms of HMOs than colostrum (Simpson's Reciprocal Diversity Index). We found an association of factor 3 in colostrum with a reduced risk of late-onset sepsis (HR: 0.63; 95% CI: 0.41, 0.97). Fucosyl-disialyllacto-N-hexose (FDSLNH) was the only oligosaccharide correlated to factor 3. CONCLUSIONS: These findings suggest that concentrations of different HMOs vary from one individual to another according to their lactation period and secretor status. We also found that FDSLNH might protect infants with very low birth weight from late-onset neonatal sepsis. Confirming this association could prove 1 more mechanism by which human milk protects infants against infections and open the door to clinical applications of HMOs.This trial was registered at clinicaltrials.gov as NCT01525316.

Maternal activation of the EGFR prevents translocation of gut-residing pathogenic Escherichia coli in a model of late-onset neonatal sepsis.

Late-onset sepsis (LOS) is a highly consequential complication of preterm birth and is defined by a positive blood culture obtained after 72 h of age. The causative bacteria can be found in patients' intestinal tracts days before dissemination, and cohort studies suggest reduced LOS risk in breastfed preterm infants through unknown mechanisms. Reduced concentrations of epidermal growth factor (EGF) of maternal origin within the intestinal tract of mice correlated to the translocation of a gut-resident human pathogen Escherichia coli, which spreads systemically and caused a rapid, fatal disease in pups. Translocation of Escherichia coli was associated with the formation of colonic goblet cell-associated antigen passages (GAPs), which translocate enteric bacteria across the intestinal epithelium. Thus, maternally derived EGF, and potentially other EGFR ligands, prevents dissemination of a gut-resident pathogen by inhibiting goblet cell-mediated bacterial translocation. Through manipulation of maternally derived EGF and alteration of the earliest gut defenses, we have developed an animal model of pathogen dissemination which recapitulates gut-origin neonatal LOS.

Neutrophil Volume, conductivity and scatter (VCS) as a screening tool in neonatal sepsis.

The initial evaluation of a suspected sepsis in a neonate is always challenging. There are many methods to screen a neonate with suspected sepsis. One of newer method is to assess the changes in neutrophil volume conductivity and scatter. The objective of this study was to establish changes in Neutrophil volume conductivity scatter (VCS) in neonatal sepsis and to determine appropriate cut off levels using receiver operating characteristic (ROC) curves. Neonates with suspected sepsis were evaluated with blood counts, culture and neutrophil VCS parameters. Based on these parameters neonates were classified into sepsis group (Blood culture positive), Probable sepsis group (clinical course consistent with sepsis and positive sepsis screen and negative blood culture), No sepsis group (Clinical course not suggestive of sepsis with negative sepsis screen and blood culture). A total of 304 neonates were included in the study of which 144 were in sepsis group and 160 in no sepsis group respectively. Among the neutrophil VCS parameters there was significant difference between the groups with respect to mean neutrophil volume (MNV) and volume distribution width (VDW) (180 vs 163 vs 150) (p < 0.01). MNV and VDW had good sensitivity (95%, 82%) and specificity (86%, 74%) for diagnosis of sepsis. In conclusion, Neutrophil VCS parameters, especially MNV, can be incorporated with other sepsis screen parameters in diagnosis of neonatal sepsis.

Progranulin as a novel biomarker in diagnosis of early-onset neonatal sepsis.

BACKGROUND: Infections are leading causes of morbidity and mortality in neonates and may also have severe long-term consequences. As early diagnosis of neonatal sepsis improves prognosis, identification of new or complementary biomarkers is of great importance. In this study, we have evaluated the diagnostic value of progranulin (PGRN) in early-onset neonatal sepsis (EOS) and compare its effectiveness with other commonly used biomarkers, such as procalcitonin (PCT) and C-reactive protein (CRP). METHODS: A total of 121 infants with gestational age of >34 weeks admitted with suspected EOS were included in this study. Before initiating therapy, blood samples for whole blood count, CRP, PCT and PGRN were obtained from all neonates. Receiver-operating characteristic (ROC) curve and multivariate logistic regression analyses were performed. RESULTS: Serum PGRN level of infected group was significantly higher than uninfected group (median 47.72 vs. 37.86 ng/ml, respectively; Mann-Whitney p < 0.0001). The ROC area under the curve (AUC) was 0.786 [95% confidence interval (CI) 0.706-0.867; p < 0.0001] for PGRN, 0.699 (95% CI 0.601-0.797; p = 0.0001) for age adjusted PCT, and 0.673 (95% CI 0.573-0.773; p = 0.0007) for CRP. With a cut-off value of 37.89 ng/ml, the diagnostic sensitivity and negative predictive value of PGRN were 94.34% and 91.7%, respectively. PGRN could significantly predict EOS independently of PCT (p < 0.0001), and the combined use of PGRN and PCT could significantly improve diagnostic performance for EOS (0.806; 95% CI 0.73-0.88; p < 0.0001), with a specificity of 89.06% and a positive predictive value of 81.10%. CONCLUSIONS: PGRN may be used as a promising biomarker for the diagnosis of EOS, and the combined use of PGRN and PCT could improve the diagnosis of sepsis.

Immunometabolic approaches to prevent, detect, and treat neonatal sepsis.

The first days of postnatal life are energetically demanding as metabolic functions change dramatically to accommodate drastic environmental and physiologic transitions after birth. It is increasingly appreciated that metabolic pathways are not only crucial for nutrition but also play important roles in regulating inflammation and the host response to infection. Neonatal susceptibility to infection is increased due to a functionally distinct immune response characterized by high reliance on innate immune mechanisms. Interactions between metabolism and the immune response are increasingly recognized, as changes in metabolic pathways drive innate immune cell function and activation and consequently host response to pathogens. Moreover, metabolites, such as acetyl-coenzyme A (acetyl-CoA) and succinate have immunoregulatory properties and serve as cofactors for enzymes involved in epigenetic reprogramming or "training" of innate immune cells after an initial infectious exposure. Highly sensitive metabolomic approaches allow us to define alterations in metabolic signatures as they change during ontogeny and as perturbed by immunization or infection, thereby linking metabolic pathways to immune cell effector functions. Characterizing the ontogeny of immunometabolism will offer new opportunities to prevent, diagnose, and treat neonatal sepsis.

Indole-3-guanylhydrazone hydrochloride mitigates long-term cognitive impairment in a neonatal sepsis model with involvement of MAPK and NFκB pathways.

BACKGROUND: Neonatal sepsis is defined as a systemic inflammatory response caused by a suspected or proven infection, occurring in the first month of life, and remains one of the main causes of morbidity and mortality in newborn and preterm infants. Frequently, survivors of neonatal sepsis have serious long-term cognitive impairment and adverse neurologic outcomes. There is currently no specific drug treatment for sepsis. Indole-3-guanylhydrazone hydrochloride (LQM01) is an aminoguanidine derivative that has been described as an anti-inflammatory, antihypertensive and antioxidant with potential applicability in inflammatory diseases. METHODS: We used a LPS-challenged neonatal sepsis rodent model to investigate the effect of LQM01 on cognitive impairment and anxiety-like behavior in sepsis mice survivors, and examined the possible molecular mechanisms involved. RESULTS: It was found that LQM01 exposure during the neonatal period reduces anxiety-like behavior and cognitive impairment caused by lipopolysaccharides (LPS) in adult life. Additionally, treatment with LQM01 decreased pro-inflammatory cytokine levels and reduced NFκB, COX-2, MAPK and microglia activation in hippocampus of neonatal mice. Furthermore, LQM01 was also able to prevent oxidative damage in hippocampus of neonatal mice and preserve brain barrier integrity. CONCLUSIONS: LQM01 attenuated inflammatory reactions in an LPS-challenged neonatal sepsis mice model through the MAPK and NFκB signaling pathways and microglia activation suppression. All these findings are associated with mitigated cognitive impairment in 70 days-old LQM01 treated-mice. GENERAL SIGNIFICANCE: We revealed the effect of LQM01 as an anti-septic agent, and the role of crucial molecular pathways in mitigating the potential damage caused by neonatal sepsis.

Complement C3a induces axonal hypomyelination in the periventricular white matter through activation of WNT/ß-catenin signal pathway in septic neonatal rats experimentally induced by lipopolysaccharide.

Neuroinflammation is thought to play a pivotal role in the pathogenesis of periventricular white matter (PWM) damage (PWMD) induced by neonatal sepsis. Because the complement cascade is implicated in inflammatory response, this study was carried out to determine whether C3a is involved in PWMD, and, if so, whether it would induce axonal hypomyelination. Furthermore, we explored if C3a would act through its C3a receptor (C3aR) and thence inhibit maturation of oligodendrocyte precursor cells (OPCs) via the WNT/ß-catenin signal pathway. Sprague Dawley (SD) rats aged 1 day were intraperitoneally injected with lipopolysaccharide (LPS) (1 mg/kg). C3a was upregulated in activated microglia and astrocytes in the PWM up to 7 days after LPS injection. Concomitantly, enhanced C3aR expression was observed in NG2+ oligodendrocytes (OLs). Myelin proteins including CNPase, PLP, MBP and MAG were significantly reduced in the PWM of 28-day septic rats. The number of PLP+ and MBP+ cells was markedly decreased. By electron microscopy, myelin sheath thickness was thinner and the average g-ratios were higher. This was coupled with an increase in number of NG2+ cells and decreased number of CC1+ cells. Olig1, Olig2 and SOX10 protein expression was significantly reduced in the PWM after LPS injection. Very strikingly, C3aRa administration for the first 7 days could reverse the above-mentioned pathological alterations in the PWM of septic rats. When incubated with C3a, expression of MBP, CNPase, PLP, MAG, Olig1, Olig2, SOX10 and CC1 in primary cultured OPCs was significantly downregulated as opposed to increased NG2. Moreover, WNT/ß-catenin signaling pathway was found to be implicated in inhibition of OPCs maturation and differentiation induced by C3a in vitro. As a corollary, it is speculated that C3a in the PWM of septic rats is closely associated with the disorder of OPCs differentiation and maturation through WNT/ß-catenin signaling pathway, which would contribute ultimately to axonal hypomyelination.

Recombinant CC16 regulates inflammation, oxidative stress, apoptosis and autophagy via the inhibition of the p38MAPK signaling pathway in the brain of neonatal rats with sepsis.

Sepsis has a high in clinic neonatal mortality. Moreover, a considerable number of children's brains remain affected even after the treatment of sepsis and it often leaves sequelae. Therefore, early intervention for sepsis is of considerable significance. Recent studies have shown that Club cell protein (CC16) is closely related to the p38 mitogen-activated protein kinase (MAPK) signaling pathway, which can regulate inflammation, oxidative stress, apoptosis, and autophagy during sepsis. Thus, we analyzed the neuroprotective effect of recombinant CC16 (rCC16) in a neonatal sepsis rat model. For the first time, we found that the p38MAPK signaling pathway was activated in neonatal brain tissue of rats with sepsis, and the CC16 levels decreased significantly. Secondly, after the rCC16 interference, the occurrence of inflammation, oxidative stress and apoptosis were subsequently reversed, and autophagy was further stimulated. Finally, through further intervention using the p38MAPK signaling pathway inhibitor, SB203580, or its agonist, anisomycin, we confirmed that rCC16 reduced rat mortality and improve general conditions. Simultaneously, it had also neuroprotective effect. Its mechanism could be related to oxidative stress, inflammation, and apoptosis reduced and autophagy activated by rCC16 inhibiting the p38MAPK signaling pathway. Taken together, these findings provide insight into the pathogenesis, prevention, and treatment of sepsis via the activity of rCC16.

Pentraxin 3 as a novel diagnostic marker in neonatal sepsis.

BACKGROUND: Neonatal sepsis is an important cause of morbidity and mortality especially in developing countries. As clinical manifestations of neonatal sepsis are nonspecific, early diagnosis and treatment remain a challenge. Pentraxin 3 (PTX3) is an acute-phase protein secreted by various cells in response to the proinflammatory signals. Our aim was to investigate the diagnostic value of PTX3 in neonatal sepsis. METHODS: We studied 90 neonates; 60 with culture-proven sepsis and 30 healthy neonates as a control group. Serum levels of PTX 3 were measured by ELISA. RESULTS: Neonates with sepsis had significantly higher levels of PTX 3 as compared to controls (p < 0.001). Diagnostic cutoff value of PTX 3 was 5.6 µg/L with a sensitivity of 98.3% and a specificity of 96.7%. PTX 3 was significantly increased in nonsurvivors when compared to survivors (p < 0.001). PTX3 had better sensitivity when compared with CRP. CONCLUSION: PTX 3 could be used as a new biomarker of neonatal sepsis with high sensitivity and specificity.