Transcriptomic markers in pediatric septic shock prognosis: an integrative analysis of gene expression profiles.

The goal of this study was to identify potential transcriptomic markers in pediatric septic shock prognosis by an integrative analysis of multiple public microarray datasets. Using the R software and bioconductor packages, we performed a statistical analysis to identify differentially expressed (DE) genes in pediatric septic shock non-survivors, and further performed functional interpretation (enrichment analysis and co-expression network construction) and classification quality evaluation of the DE genes identified. Four microarray datasets (3 training datasets and 1 testing dataset, 252 pediatric patients with septic shock in total) were collected for the integrative analysis. A total of 32 DE genes (18 upregulated genes; 14 downregulated genes) were identified in pediatric septic shock non-survivors. Enrichment analysis revealed that those DE genes were strongly associated with acute inflammatory response to antigenic stimulus, response to yeast, and defense response to bacterium. A support vector machine classifier (non-survivors vs survivors) was also trained based on DE genes. In conclusion, the DE genes identified in this study are suggested as candidate transcriptomic markers for pediatric septic shock prognosis and provide novel insights into the progression of pediatric septic shock.

Transcriptomic markers in pediatric septic shock prognosis: an integrative analysis of gene expression profiles

The goal of this study was to identify potential transcriptomic markers in pediatric septic shock prognosis by an integrative analysis of multiple public microarray datasets. Using the R software and bioconductor packages, we performed a statistical analysis to identify differentially expressed (DE) genes in pediatric septic shock non-survivors, and further performed functional interpretation (enrichment analysis and co-expression network construction) and classification quality evaluation of the DE genes identified. Four microarray datasets (3 training datasets and 1 testing dataset, 252 pediatric patients with septic shock in total) were collected for the integrative analysis. A total of 32 DE genes (18 upregulated genes; 14 downregulated genes) were identified in pediatric septic shock non-survivors. Enrichment analysis revealed that those DE genes were strongly associated with acute inflammatory response to antigenic stimulus, response to yeast, and defense response to bacterium. A support vector machine classifier (non-survivors vs survivors) was also trained based on DE genes. In conclusion, the DE genes identified in this study are suggested as candidate transcriptomic markers for pediatric septic shock prognosis and provide novel insights into the progression of pediatric septic shock.

Hydrostatin-TL1, an Anti-Inflammatory Active Peptide from the Venom Gland of Hydrophis cyanocinctus in the South China Sea.

Tumor necrosis factor (TNF)-α is a pleiotropic cytokine with intense pro-inflammatory and immunomodulatory properties, and anti-TNF-α biologics are effective therapies for various inflammatory diseases such as inflammatory bowel disease (IBD) and sepsis. Snake venom, as a traditional Chinese medicine, has been used in the treatment of inflammatory diseases in China for centuries. In this research, we constructed a venom gland T7 phage display library of the sea snake Hydrophis cyanocinctus to screen bioactive compounds that antagonize TNF-α and identified a novel nine-amino-acid peptide, termed hydrostatin-TL1 (H-TL1). In enzyme-linked immunosorbent assay (ELISA) and surface plasmon resonance (SPR) analyses, H-TL1 inhibited the interaction between TNF-α and TNF receptor 1 (TNFR1). Further, H-TL1 attenuated the cytotoxicity of TNF-α in L929 cells as determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. H-TL1 also decreased the mRNA expression of TNF-α/TNFR1 downstream targets and suppressed the phosphorylation of well-characterized proteins of downstream signal transduction pathways in HEK-293 cells. In vivo data demonstrated that H-TL1 protects animals against dextran sodium sulfate (DSS)-induced acute colitis and lipopolysaccharide (LPS)-induced acute shock. Given its significant anti-inflammatory activity in vitro and in vivo, H-TL1 is a potential peptide for the development of new agents to treat TNF-α-associated inflammatory diseases.

Inhibitory Effect of Three Diketopiperazines from Marine-Derived Bacteria on HMGB1-Induced Septic Responses in Vitro and in Vivo.

The nucleosomal protein high-mobility group box-1 (HMGB1), which has recently been established as a late mediator of lethal systemic inflammation, has a relatively wide therapeutic window for pharmacological interventions. Compounds produced by marine-derived microbes have been widely investigated for their potential use as bioactive natural products. Cyclic dipeptides, which are also known as diketopiperazines, are molecules that are frequently found in marine-derived microorganisms. While their pharmacological potential has been well established, their biological activities against septic responses have not yet been reported. Here, three diketopiperazines (1-3) isolated from two strains of marine-derived bacteria were investigated for their potential activities against HMGB1-mediated septic responses. The data showed that 1-3 effectively inhibited the lipopolysaccharide (LPS)-induced release of HMGB1 and suppressed the HMGB1-mediated septic responses, including hyperpermeability, leukocyte adhesion and migration, and cell adhesion molecule expression. In addition, 1-3 inhibited the HMGB1-mediated production of tumor necrosis factor-[Formula: see text] (TNF-[Formula: see text] and interleukin (IL)-6 and the activation of nuclear factor-[Formula: see text]B (NF-[Formula: see text]B) and extracellular signal-regulated kinase (ERK) 1 and ERK2. Collectively, these results indicated that 1-3 might act as potential therapeutic agents for various severe vascular inflammatory diseases through the inhibition of the HMGB1 signaling pathway.

Relationship between iNOS expression and apoptosis in cerebral tissue, and the effect of sini injection in endotoxin shock rats.

OBJECTIVE: To investigate the dynamic changes and relationship of inducible nitric oxide synthase (iNOS) and apoptosis in endotoxin shock rats, as well as the effects of Sini injection. METHODS: In total, 102 Sprague-Dawley (SD) rats were randomly divided into a normal group (n = 6, NG), sham operation group (n = 24, OG), model group (n = 24, MG), dexamethasone group (n = 24, DG), and Sini group (n = 24, SG). The endotoxin shock model was induced by an intravenous injection of lipopolysaccharide (LPS) (8 mg/kg). Rats in the OG, MG, DG, and SG groups were further divided into 4 groups: 1, 2, 3 and 6 h after shock groups (n = 6 per group). iNOS expression was detected by immunohistochemistry. Terminal Deoxynucleotidyl Transferase Mediated Deoxyuridine Triphosphate-biotin Nick End Labeling was employed to measure apoptosis. RESULTS: No iNOS expression was found in the OG group. Compared with the OG group, iNOS expression in the MG group was markedly elevated, reached a peak at 1 h (P < 0.01), decreased at 2 and 3 h, and rebounded at 6 h. Compared with the MG group, iNOS expression decreased significantly in both the DG (P < 0.05) and SG (P < 0.01) groups at 6 h. The number of apoptotic cells in the MG group was markedly increased than that in the NG and OG (P < 0.01) groups, and reached a peak at 6 h. The number of apoptotic cells in the DG group at 1 and 2 h (P < 0.01) and SG group at 2, 3 and 6 h (P < 0.01) decreased when compared with the MG group. CONCLUSION: Sini injection can significantly inhibit NO generation, which decreases apoptosis and subsequently protects the brain from endotoxic shock.

Contribution of iNOS/sGC/PKG pathway, COX-2, CYP4A1, and gp91(phox) to the protective effect of 5,14-HEDGE, a 20-HETE mimetic, against vasodilation, hypotension, tachycardia, and inflammation in a rat model of septic shock.

We have previously demonstrated that a stable synthetic analog of 20-hydroxyeicosatetraenoic acid (20-HETE), N-[20-hydroxyeicosa-5(Z),14(Z)-dienoyl]glycine (5,14-HEDGE), prevents vascular hyporeactivity, hypotension, tachycardia, and inflammation in rats treated with lipopolysaccharide (LPS) and mortality in endotoxemic mice. These changes were attributed to decreased production of inducible nitric oxide (NO) synthase (iNOS)-derived NO, cyclooxygenase (COX)-2-derived vasodilator prostanoids, and proinflammatory mediators associated with increased cyctochrome P450 (CYP) 4A1-derived 20-HETE and CYP2C23-dependent antiinflammatory mediator formation. The aim of this study was to determine whether decreased expression and activity of iNOS, soluble guanylyl cyclase (sGC), protein kinase G (PKG), COX-2, gp91(phox) (NOX2; a superoxide generating NOX enzyme), and peroxynitrite production associated with increased expression of COX-1 and CYP4A1 and 20-HETE formation in renal and cardiovascular tissues of rats contributes to the effect of 5,14-HEDGE to prevent vasodilation, hypotension, tachycardia, and inflammation in response to systemic administration of LPS. Mean arterial pressure fell by 28mmHg and heart rate rose by 47beats/min in LPS (10mg/kg, i.p.)-treated rats. Administration of LPS also increased mRNA and protein expression of iNOS and COX-2 associated with a decrease in COX-1 and CYP4A1 mRNA and protein expression. Increased NOS activity, iNOS-heat shock protein 90 complex formation (an index for iNOS activity), protein expression of phosphorylated vasodilator stimulated phosphoprotein (an index for PKG activity), gp91(phox), p47(phox) (NOXO2; organizer subunit of gp91(phox)), and nitrotyrosine (an index for peroxynitrite production) as well as cGMP (an index for sGC activity), 6-keto-PGF1α (a stable metabolite PGI2) and PGE2 levels (indexes for COX activity), and nitrotyrosine levels by LPS were also associated with decreased CYP hydroxylase activity as measured by 20-HETE formation from arachidonic acid in renal microsomes of LPS-treated rats. These effects of LPS, except iNOS mRNA and COX-1 protein expression, were prevented by 5,14-HEDGE (30mg/kg, s.c.; 1h after LPS). A competitive antagonist of vasoconstrictor effects of 20-HETE, 20-hydroxyeicosa-6(Z),15(Z)-dienoic acid (30mg/kg, s.c.; 1h after LPS) reversed the effects of 5,14-HEDGE, except iNOS and COX-1 mRNA and protein expression as well as expression of CYP4A1 mRNA. These results suggest that increased CYP4A1 expression and 20-HETE formation associated with suppression of iNOS/sGC/PKG pathway, COX-2, and gp91(phox) participate in the protective effect of 5,14-HEDGE against vasodilation, hypotension, tachycardia, and inflammation in the rat model of septic shock.

Combined administration of anisodamine and neostigmine produces anti-shock effects: involvement of α7 nicotinic acetylcholine receptors.

AIM: To evaluate the anti-effects of anisodamine and neostigmine in animal models of endotoxic and hemorrhagic shock. METHODS: Kunming mice were injected with lipopolysaccharide (LPS 30 mg/kg, ip) to induce endotoxic shock. Anisodamine (12.5, 25, and 50 mg/kg, ip) and neostigmine (12.5, 25, and 50 µg/kg, ip) were administered immediately after LPS injection. Survival rate was monitored, and the serum levels of TNF-α and IL-1ß were analyzed using ELISA assays. The effects of anisodamine and neostigmine were also examined in α7 nicotinic acetylcholine receptor (α7 nAChR) knockout mice with endotoxic shock and in Beagle dogs with hemorrhagic shock. RESULTS: In mice with experimental endotoxemia, combined administration of anisodamine and neostigmine significantly increased the survival rate and decreased the serum levels of inflammatory cytokines, as compared to those produced by either drug alone. The anti-shock effect of combined anisodamine and neostigmine was abolished in α7 nAChR knockout mice. On the other hand, intravenous injection of the combined anisodamine and neostigmine, or the selective α7 nAChR agonist PNU282987 exerted similar anti-shock effects in dogs with hemorrhagic shock. CONCLUSION: The results demonstrate that combined administration of anisodamine and neostigmine produces significant anti-shock effects, which involves activation of α7 nAChRs.

Genetics and genomics in pediatric septic shock.

OBJECTIVES: Pediatric septic shock continues to be an important public health problem. Several investigative groups have applied genetic and genomic approaches as a means of identifying novel pathways and therapeutic targets, discovery of sepsis-related biomarkers, and identification of septic shock subclasses. This review will highlight studies in pediatric sepsis with a focus on gene association studies and genome-wide expression profiling. DATA SOURCES: A summary of published literature involving gene association and expression profiling studies specifically involving pediatric sepsis and septic shock. SUMMARY: Several polymorphisms of genes broadly involved in inflammation, immunity, and coagulation have been linked with susceptibility to sepsis, or outcome of sepsis in children. Many of these studies involve meningococcemia, and the strongest association involves a functional polymorphism of the plasminogen activator inhibitor-1 promoter region and meningococcal sepsis. Expression profiling studies in pediatric septic shock have identified zinc supplementation and inhibition of matrix metalloproteinase-8 activity as potential, novel therapeutic approaches in sepsis. Studies focused on discovery of sepsis-related biomarkers have identified interleukin-8 as a robust outcome biomarker in pediatric septic shock. Additional studies have demonstrated the feasibility and clinical relevance of gene expression-based subclassification of pediatric septic shock. CONCLUSIONS: Pediatric sepsis and septic shock are increasingly being studied by genetic and genomic approaches and the accumulating data hold the promise of enhancing our future approach to this ongoing clinical problem.