Yueqiu Qin

The association of polymorphisms of TLR4 and CD14 genes with susceptibility to sepsis in a Chinese population

BackgroundSepsis is now the leading cause of death in the non-cardiovascular intensive care unit (ICU). Recent research suggests that sepsis is likely to be due to an interaction between genetic and environmental factors. Genetic mutations of toll-like receptor 4 (TLR4) and cluster of differentiation 14 (CD14) genes are involved in the immune and (or) inflammatory response. These may contribute to the susceptibility to sepsis in patients. This study was designed to evaluate whether the TLR4 and cluster CD14 gene polymorphisms are associated with susceptibility to sepsis.MethodsThe single nucleotide polymorphisms (SNPs) of TLR4 (rs10759932, rs11536889, rs7873784, rs12377632, rs1927907, rs1153879) and CD14 (rs2569190 and rs2563298) in patients with sepsis and control subjects in the Guangxi Province were analyzed by using the polymerase chain reaction-single base extension (PCR-SBE) and DNA sequencing methods.ResultsThe rs11536889 polymorphism in TLR4 and rs2563298 polymorphism in CD14 were significantly associated with the risk of sepsis when compared to the control group. The frequencies of rs11536889 and rs2563298 polymorphisms in the group with sepsis were higher than that in the control group (OR = 1.430, 95% CI, 1.032-1.981, P<0.05; OR = 2.454, 95% CI, 1.458-4.130, P<0.05, respectively). Followed up haplotype analysis suggested that there were two haplotypes in which increased risk factors for sepsis were indicated.ConclusionsThe rs11536889 polymorphism in TLR4 and rs2563298 polymorphism in CD14, and two haplotypes were associated with increased susceptibility to sepsis.

Overexpression of Fas and FasL Is Associated with Infectious Complications and Severity of Experimental Severe Acute Pancreatitis by Promoting Apoptosis of Lymphocytes

This study investigated the relationship of Fas and Fas ligand (FasL) expression and apoptosis of lymphocytes in relation to the pathogenic immune response and infectious complications observed in experimental severe acute pancreatitis in mice. Forty male Balb/c mice were randomly divided into control, mild (MAP), and severe acute pancreatitis (SAP) groups. Overexpression of Fas/FasL messenger ribonucleic acid (mRNA) and protein was observed in spleen-derived lymphocytes in SAP (p < 0.01). Apoptosis of these resulted in a depletion of circulating lymphocytes in this group (p < 0.05). A further significant change in the SAP group with infectious complications was observed. A positive relationship was found between the Fas/FasL expression and lymphocyte apoptosis, and negative relationships were observed between Fas/FasL expression and CD4+ and CD19+ lymphocytes and the CD4+/CD8+ ratio in SAP mice (p < 0.01). The results suggest that the overexpression of Fas/FasL is associated with infectious complications and severity of experimental severe acute pancreatitis by promoting apoptosis of lymphocytes.

Investigation of association between IL-8 serum levels and IL8 polymorphisms in Chinese patients with sepsis.

OBJECTIVE To assess the clinical relevance of IL8 gene polymorphisms in patients with sepsis and its association with systemic IL-8 levels. METHODS PCR and DNA sequencing were used to examine the polymorphism of IL8 in 152 patients with sepsis and in 199 healthy volunteers in China. The distribution frequencies of the genotype and allele were compared among different groups. The serum IL-8 was measured by ELISA and analyzed in relation to polymorphisms of IL8. RESULTS The homozygote TT genotype and T allele of rs4073 (genotype: p=0.01, allele: p=0.002), the homozygote CC genotype and C allele (genotype: p=0.03, allele: p=0.003) of rs2227306, homozygote AA genotype and A allele of re1126647 (genotype: p=0.01, allele: p=0.002) were associated with susceptibility to sepsis in males. Serum IL-8 levels were significantly increased in patients with sepsis but showed no correlation with IL8 rs4073, rs2227306 and rs1126647 polymorphisms. CONCLUSIONS The male population carrying the homozygote TT genotype and T allele of rs4073, the homozygote CC genotype and C allele of rs2227306 and homozygote AA genotype and A allele of rs1126647 are more susceptible to sepsis, suggesting there is a protective effect in females carrying these genotypes and alleles respectively. There was no association between rs4073, rs2227306 and rs1126647 polymorphisms and serum levels of IL-8 in patients with sepsis.

Lipopolysaccharide-Binding Protein Downregulates Fractalkine through Activation of p38 MAPK and NF-κB

Background LBP and fractalkine are known to be involved in the pathogenesis of ARDS. This study investigated the relationship between LBP and fractalkine in LPS-induced A549 cells and rat lung tissue in an ARDS rat model. Methods A549 cells were transfected with LBP or LBP shRNA plasmid DNA or pretreated with SB203580 or SC-514 following LPS treatment. An ARDS rat model was established using LPS with or without LBPK95A, SB203580, or SC-514 treatment. RT-PCR, western blotting, ELISA, immunofluorescence, coimmunoprecipitation, and immunohistochemical staining were used to study the expression of fractalkine and LBP and p38 MAPK and p65 NF-κB activities. Results LPS increased LBP and reduced fractalkine. LBP overexpression further decreased LPS-induced downregulation of fractalkine and p38 MAPK and p65 NF-κB activation; LBP gene silencing, SB203580, and SC-514 suppressed LPS-induced downregulation of fractalkine and p38 MAPK and p65 NF-κB activation in A549 cells. LBP and fractalkine in lung tissue were increased and decreased, respectively, following LPS injection. LBPK95A, SB203580, and SC-514 ameliorated LPS-induced rat lung injury and suppressed LPS-induced downregulation of fractalkine by decreasing phospho-p38 MAPK and p65 NF-κB. Conclusions The results indicate that LBP downregulates fractalkine expression in LPS-induced A549 cells and in an ARDS rat model through activation of p38 MAPK and NF-κB.

Nur77 attenuates endothelin-1 expression via downregulation of NF-κB and p38 MAPK in A549 cells and in an ARDS rat model

Acute respiratory distress syndrome (ARDS) is characterized by inflammatory injury to the alveolar and capillary barriers that results in impaired gas exchange and severe acute respiratory failure. Nuclear orphan receptor Nur77 has emerged as a regulator of gene expression in inflammation, and its role in the pathogenesis of ARDS is not clear. The objective of this study is to investigate the potential role of Nur77 and its underlying mechanism in the regulation of endothelin-1 (ET-1) expression in lipopolysaccharide (LPS)-induced A549 cells and an ARDS rat model. We demonstrate that LPS induced Nur77 expression and nuclear export in A549 cells. Overexpression of Nur77 markedly decreased basal and LPS-induced ET-1 expression in A549 cells, whereas knockdown of Nur77 increased the ET-1 expression. LPS-induced phosphorylation and nuclear translocation of NF-κB and p38 MAPK were blocked by Nur77 overexpression and augmented by Nur77 knockdown in A549 cells. In vivo, LPS induced Nur77 expression in lung in ARDS rats. Pharmacological activation of Nur77 by cytosporone B (CsnB) inhibited ET-1 expression in ARDS rats, decreased LPS-induced phosphorylation of NF-κB and p38 MAPK, and relieved lung, liver, and kidney injury. Pharmacological deactivation of Nur77 by 1,1-bis-(3′-indolyl)-1-(p-hydroxyphenyl)methane (DIM-C-pPhOH, C-DIM8) had no effect on ET-1 expression and lung injury. These results indicated that Nur77 decreases ET-1 expression by suppressing NF-κB and p38 MAPK in LPS-stimulated A549 cells in vitro, and, in an LPS-induced ARDS rat model, CsnB reduced ET-1 expression and lung injury in ARDS rats.

Endothelial protein C receptor polymorphisms and risk of sepsis in a Chinese population

Objective To examine the potential relationship of EPCR polymorphisms and the risk of sepsis in a Chinese population. Methods Snapshot SNP genotyping assays and DNA sequencing methods were used to detect polymorphisms of the EPCR gene, rs2069948C/T (2532C/T) and rs867186A/G (6936A/G), in 64 patients with sepsis and in 113 controls. Soluble EPCR (sEPCR) was measured by ELISA. Results There were significant differences in the allele and genotype frequencies of EPCR gene rs2069948C/T and allele frequencies of rs867186A/G between male and female patients and controls. Females carrying rs2069948 C/T genotype or T allele and males carrying rs867186 A allele were associated with a significantly increased risk of sepsis. Plasma sEPCR levels of sepsis patients were higher than controls and showed no correlation with EPCR gene polymorphisms. Conclusions EPCR polymorphisms may be associated with increased risk of sepsis, but this has no effect on the release of sEPCR in patients with sepsis.

Inhibition of Lipopolysaccharide-Induced Expression of Fractalkine byMethylprednisolone via NF-Κb in Human Renal Tubular Epithelial Cells

Objective: to study the effect of the glucocorticoid, methylprednisolone (MP), in lipopolysaccharide (LPS)-induced fractalkine (FKN) expression in HK-2 cells and to determine the role of NF-κB in this signaling pathway. Methods: HK-2 cells were stimulated by LPS to set up an in vitro inflammation model. The concentration of FKN in cell culture supernatant was measured by ELISA. FKN and p65 mRNA expression were detected by RT-PCR. FKN, p65 protein expression and the activity of the NF-κB were detected by immunofluorescence staining and western blotting. The effect of MP and SC-514 (a selective and reversible inhibitor of IKK beta) in FKN expression and NF-κB activation induced by LPS were evaluated. Results: LPS induced FKN expression and secretion in HK-2 cells occurred in a time- and dose-dependent manner and correlated with the activation of NF-κB. MP was able to inhibit FKN expression and secretion as well as the NF-κB induced activation of LPS, whereas SC-514 abolished this effect. Conclusions: MP inhibited FKN expression induced by LPS through the NF-κB pathway in human renal tubular epithelial cells in vitro. Use of HK-2 cells to study the renal inflammatory process will allow the further elucidation of the pathways involved in kidney disease.

Upregulated fractalkine levels in Chinese patients with lupus nephritis

Objective: To investigate the expression levels of fractalkine (FKN) mRNA in peripheral blood mononuclear cells (PBMCs) and FKN protein in serum of patients with lupus nephritis (LN) from China, and to evaluate the associations between the expression of FKN and systemic lupus erythematosus disease activity index 2000 (SLEDAI‐2K), anti‐double‐stranded DNA and complement proteins in LN patients. Methods: Real‐time quantitative polymerase chain reaction and enzyme‐linked immunosorbent assay were used to detect the expression levels of FKN mRNA in PBMCs and FKN protein in serum separately from 105 patients with LN and 52 healthy controls. Results: Serum level and mRNA level of FKN were significantly increased in LN patients when compared to controls (P<0.001). Higher FKN levels were found in active LN patients and LN patients with renal damage when compared with inactive LN patients and LN patients without renal damage (P<0.001). Higher serum FKN levels were detected in inactive LN patients in comparison with healthy controls (Z=−7.165, P<0.001). The FKN expression levels were positively correlated with SLEDAI‐2K, and was associated with the presence of autoantibodies and negatively correlated with complement proteins C3 and C4 in LN patients. Conclusions: The results suggest that upregulation of FKN is associated with the pathogenesis and activity of LN in Chinese patients. HIGHLIGHTSRelationship between fractalkine (FKN) expression and lupus nephritis (LN).qPCR and ELISA to detect the expression levels of FKN in LN patients and controls.Serum and mRNA levels of FKN were significantly increased in LN patients.The FKN expression levels were positively correlated with disease activity.The data suggest that up‐regulation of FKN is associated with pathogenesis of LN.