Prognostic significance of soluble CD25 in patients with sepsis: a prospective observational study.

OBJECTIVES: The diagnosis of sepsis is challenging, the need for sensitive and specific diagnostic and prognostic biomarkers has not been met. Soluble CD25 (sCD25) is a readily available biomarker reported to represent the severity of the disease. This study aimed to assess the association between sCD25 and mortality in patients with sepsis. METHODS: In total, 329 adult patients with sepsis were screened through a prospective, observational study. We investigated the severity scores and sCD25 levels at admission to the intensive care unit (ICU), defined by sepsis (sepsis-3). The prognostic value of sCD25 was assessed using receiver operating characteristic (ROC) curves and binary logistic regression models in predicting unfavourable outcome. The correlations between variables and severity of disease were analysed by Spearman correlation tests. RESULTS: After entering the ICU, the sCD25 level and sequential organ failure assessment (SOFA) score were significantly higher in nonsurvivors than in survivors. The prognostic values estimated by the ROC curves were 0.678 for sCD25 and 0.945 for SOFA score at ICU admission. sCD25 had a modest ability to predict poor outcome. Logistic regression showed that increased levels of sCD25 were independently associated with unfavourable outcome. Spearman correlation tests showed that sCD25 levels were positively correlated with disease severity. CONCLUSIONS: In sepsis patients, increased sCD25 levels were independently associated with poor clinical outcomes. Further research is needed to improve the understanding of the pathophysiology of this relationship.

Differentially expressed miRNAs in sepsis-induced acute kidney injury target oxidative stress and mitochondrial dysfunction pathways.

OBJECTIVE: To identify specific miRNAs involved in sepsis-induced AKI and to explore their targeting pathways. METHODS: The expression profiles of miRNAs in serum from patients with sepsis-induced AKI (n = 6), sepsis-non AKI (n = 6), and healthy volunteers (n = 3) were investigated by microarray assay and validated by quantitative PCR (qPCR). The targets of the differentially expressed miRNAs were predicted by Target Scan, mirbase and Miranda. Then the significant functions and involvement in signaling pathways of gene ontology (GO) and KEGG pathways were analyzed. Furthermore, eight miRNAs were randomly selected out of the differentially expressed miRNAs for further testing by qPCR. RESULTS: qPCR analysis confirmed that the expressions levels of hsa-miR-23a-3p, hsa-miR-4456, hsa-miR-142-5p, hsa-miR-22-3p and hsa-miR-191-5p were significantly lower in patients with sepsis compared with the healthy volunteers, while hsa-miR-4270, hsa-miR-4321, hsa-miR-3165 were higher in the sepsis patients. Statistically, miR-4321; miR-4270 were significantly upregulated in the sepsis-induced AKI compared with sepsis-non AKI, while only miR-4321 significantly overexpressed in the sepsis groups compared with control groups. GO analysis showed that biological processes regulated by the predicted target genes included diverse terms. They were related to kidney development, regulation of nitrogen compound metabolic process, regulation of cellular metabolic process, cellular response to oxidative stress, mitochondrial outer membrane permeabilization, etc. Pathway analysis showed that several significant pathways of the predicted target genes related to oxidative stress. miR-4321 was involved in regulating AKT1, mTOR and NOX5 expression while miR-4270 was involved in regulating PPARGC1A, AKT3, NOX5, PIK3C3, WNT1 expression. Function and pathway analysis highlighted the possible involvement of miRNA-deregulated mRNAs in oxidative stress and mitochondrial dysfunction. CONCLUSION: This study might help to improve understanding of the relationship between serum miRNAs and sepsis-induced AKI, and laid an important foundation for further identification of the potential mechanisms of sepsis-induced AKI and oxidative stress and mitochondrial dysfunction.

Inhibition of TLR4 protects rat islets against lipopolysaccharide-induced dysfunction.

Oxidative stress leads to dysfunction in pancreatic cells, causing a reduction in insulin secretion following exposure to glucose. Toll-like receptor 4 (TLR4) may be activated by exposure to lipopolysaccharide (LPS) stress. TLR4 may mediate the initiation of inflammatory and immune defense responses; however, the importance of the LPS/TLR4 interaction in apoptosis induced by oxidative stress in pancreatic ß cells remains to be elucidated. The present study aimed to investigate the importance of TLR4 during LPS­induced oxidative stress, apoptosis and dysfunction of insulin secretion in isolated islets of rats. LPS­induced stimulation of TLR4 increased the production of reactive oxygen species and promoted apoptosis by upregulating the expression levels of caspase­3, poly ADP ribose polymerase and altering the expression ratio of B­cell lymphoma­2 (Bcl­2)/Bcl­2 associated X protein. Additionally, the insulin secretion of islets cells was reduced. Anti­TLR4 antibody and a knockdown of TLR4 by TLR4­short hairpin RNA were used to inhibit TLR4 activity, which may reverse LPS­induced events. The present study determined that in islets exposed to LPS oxidative stress, dysfunction may be partly mediated via the TLR4 pathway. Inhibition of TLR4 may prevent dysfunction of rat islets due to oxidative stress. The present study revealed that targeting the LPS/TLR4 signaling pathway and antioxidant therapy may be a novel treatment for the severely septic patients with hyperglycemia stress.

Serum uric acid is neuroprotective in Chinese patients with acute ischemic stroke treated with intravenous recombinant tissue plasminogen activator.

BACKGROUND: Exogenous uric acid (UA) is a neuroprotective antioxidant that reinforces the benefits of intravenous recombinant tissue plasminogen activator thrombolysis in animal thromboembolic stroke. However, whether serum uric acid (SUA) also increases the benefits of thrombolysis in Chinese patients with acute ischemic stroke (AIS) has yet to be fully defined. METHODS: A total of 216 consecutive AIS patients of Chinese origin treated with intravenous thrombolysis were enrolled in a prospective stroke registry. Demographic and clinical characteristics, conventional risk factors, important laboratory data, and neurologic course were prospectively recorded. Functional outcomes were assessed with the modified Rankin Scale (mRS) score on day 90 by telephone calls. Receiver operating characteristic curves and binary logistic regression models were used to examine the performance of SUA in predicting excellent outcomes (mRS, 0-1). RESULTS: SUA levels were significantly higher in patients with excellent outcomes than those in patients with poor outcomes (331.46 ± 103.39 versus 277.69 ± 105.62, P = .008). SUA had a modest power for predicting excellent outcomes as suggested by area under the curve of .665 ± .052, P = .003. In multivariate models, increased SUA levels (adjusted odds ratio, 1.005; 95% confidence interval, 1.002-1.009; P = .033) were associated with excellent outcomes independently of the effect of possible confounders. Spearman correlation tests indicated that there was an inverse correlation between SUA levels and stroke severity. CONCLUSIONS: Increased SUA levels are associated with excellent outcomes in Chinese patients with AIS treated with intravenous thrombolysis, giving additional support to administration of exogenous UA as an adjuvant to thrombolysis.

Effects of intermittent high glucose on oxidative stress in endothelial cells.

The objective of this study is to explore the mechanism of oxidative stress induced by intermittent high glucose in porcine iliac endothelial cells (PIECs). The PIECs were exposed to intermittent or constant high glucose for 3 or 6 days, and the mean fluorescent intensity (MFI) was measured via intracellular reactive oxygen species (ROS) captured by flow cytometry. The NADPH oxidase activity was measured by chemiluminescence with lucigenin. Intermittent high glucose induced a greater over-production of ROS than constant high glucose in PIECs; the NADPH oxidase activity was increased under both constant and intermittent high glucose conditions, being more marked in the latter (P < 0.05). In conclusion, intermittent high glucose induced more ROS in PIECs than constant high glucose, this effect seemed to be, at least in part related to the enhanced activation of NADPH oxidase. Glucose fluctuation may be involved in the development of vascular complications.