Binwu Ying

Quercetin inhibits IL-1 beta-induced ICAM-1 expression in pulmonary epithelial cell line A549 through the MAPK pathways

Quercetin is a herbal flavonoid derived from various foods of plant origin and widely used as a major constituent of nutritional supplements. Quercetin has been shown to have anti-inflammatory properties and can play a role in anti-inflammatory procedure. Intercellular adhesion molecule-1 (ICAM-1) is one of the important pro-inflammatory factors, especially in early phage of inflammation. However, the mechanisms regulating ICAM-1 expression by quercetin in human A549 cells were still unclear. In this study, the inhibitory effect of quercetin on ICAM-1 expression by interleukin-1 beta (IL-1 beta)-stimulated A549 cells was investigated, and the roles of mitogen-activated protein kinases (MAPK) pathways were explored. Quercetin attenuated IL-1 beta-induced expression of ICAM-1 mRNA and protein in a dose-dependent manner. The experiment suggested that quercetin actively inhibited inhibitory protein of nuclear factor-kappa B (I kappa B) degradation, and nuclear factor-kappa B (NF-kappa B) activity. The c-fos and c-jun, components of activator protein-1 (AP-1), were mediated by MAPK pathways. ERK and p38 were involved in the c-fos mRNA expression, and JNK was involved in the c-jun mRNA expression. The inhibitory effect of quercetin on ICAM-1 expression was mediated by the sequential attenuation of the c-fos and c-jun mRNA expressions. These inhibitory effects were partially inhibited by SB203580, a specific inhibitor of p38 MAPK, but not by PD98059, a specific inhibitors of extracellular signal-regulated kinase (ERK), and SP600125, a specific inhibitor of c-Jun-N-terminal kinase (JNK). Taken together, these results suggest that quercetin negatively modulating ICAM-1 partly dependent on MAPK pathways.

Association of polymorphisms in pre-miRNA with inflammatory biomarkers in rheumatoid arthritis in the Chinese Han population

The aim of this study was to detect the association between 2 single nucleotide polymorphisms (SNPs), rs2910164 G>C and rs3746444 T>C, in pre-miRNA (hsa-mir-146a and hsa-mir-499) and the chronic inflammation in the Chinese Han population with rheumatoid arthritis (RA). Two hundred sixty-two Han Chinese patients with RA were recruited in this study. The SNPs were genotyped by polymerase chain reaction restriction fragment length polymorphism. C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and the plasma concentrations of interleukin (IL)-6, tumor necrosis factor α (TNF-α), and transforming growth factor β1 (TGF-β1) were measured. There was a significant difference in the levels of CRP and ESR among different genotypes in rs3746444 (p = 0.031 and p = 0.047, respectively). The heterozygote CT had significantly higher levels of CRP and ESR compared with homozygotes CC and TT. No significant association was observed between the SNP rs2910164 and the levels of CRP, ESR, IL-6, TNF-α, and TGF-β1 (all p > 0.05). The results of this study provided the first evidence that the SNP rs3746444 in pre-miR-499 could affect the inflammatory reaction in patients with RA. The findings were significant and might contribute to the clinical assessment of inflammatory activity, which in turn may influence therapeutic decision making.

Association Between Two Genetic Variants in miRNA and Primary Liver Cancer Risk in the Chinese Population

MicroRNAs (miRNAs) play an important role in the growth and development of human beings. Single nucleotide polymorphisms (SNPs) within miRNA could change their production or affinity with target genes, thus leading to malignant diseases. This case-control study conducted in Western China aimed to explore the relationship between polymorphisms in miR-146a (rs2910164 G>C) and miR-499 (rs3746444 T>C) and primary liver cancers in the Chinese population. 186 primary liver cancer cases and 483 healthy controls were genotyped using polymerase chain reaction-restriction fragment length polymorphism. No significant differences were observed between distributions of the two SNPs and susceptibility of primary liver cancer or diverse clinicopathologic features. However, we found that patients with genotype CG of the SNP in miR-146a tended to have earlier onset and better liver function than patients with genotype CC (average age: 49.9 vs. 54.9, p=0.038; average Child-Pugh grade: 5.55 vs. 6.15, p=0.021), and further analysis showed that patients who had at least one G allele were diagnosed at an earlier age (average age: 49.6 vs. 54.9, p=0.022) and had better liver function (average Child-Pugh grade:5.60 vs. 6.15, p=0.026). Our data suggested lack of association between the two SNPs and primary liver cancer risk, though, interestingly, the miR-146a SNP may influence the age of onset and Child-Pugh grade.

Genetic study of two single nucleotide polymorphisms within corresponding microRNAs and susceptibility to tuberculosis in a Chinese Tibetan and Han population

MicroRNAs (miRNA) are thought to play important roles in the pathogenesis of diseases. Single nucleotide polymorphisms (SNPs) within miRNAs can change their characteristics via altering their target selection and/or expression, resulting in functional and/or phenotypic changes. We decided to investigate the genetic association with pulmonary tuberculosis with 2 nucleotide variations within corresponding microRNAs regulating the Toll-like receptor (TLR)-mediating signal pathway. MiRNAs potentially regulating the TLR-mediating signal pathway were predicted via bioinformatics. Finally, 2 SNPs, rs2910164 G>C and rs3746444 T>C within miR-146a and miR-499, were selected as candidates in accordance with some criteria. SNPs were genotyped by polymerase chain reaction-restriction fragment length polymorphism and validated by sequencing to demonstrate their association with susceptibility to pulmonary tuberculosis (PTB) in 337 PTB cases and 738 healthy controls, including 318 Tibetan and 757 Han individuals. Bioinformatics databases were searched to support the association between miRNAs and PTB. There was no association between rs3746444 and PTB risk (p = 0.118) in the Han population, but subjects carrying the C allele exhibited decreased PTB risk (odds ratio [OR] = 0.403 [95% confidence interval (95% CI) 0.278-0.583]). However, there was an association between rs3746444 and PTB in the Tibetan population, and individuals carrying the C allele exhibited increased PTB risk (OR = 1.870 [95% CI 1.218-2.871]). A polymorphism (rs2910164 G>C) indicated an association with PTB risk in both Tibetan (p = 0.031) and Han (p = 0.000) populations. However, the role of the G allele of rs2910164, like the C allele in rs3746444, differed in the Tibetan (OR = 1.509, p < 0.05) and Han (OR = 0.575, p < 0.05) groups. This is the first report to suggest that a genetic association with pulmonary tuberculosis with SNPs within the corresponding miRNAs potentially regulates the TLR signal pathway. It is interesting that both the G allele (rs2910164) and the C allele (rs3746444) play different roles in 2 populations. Further functional analysis of the SNP and its impact on mRNA targets is required to confirm the relationship between genotype and phenotype.

Precore Mutation of Hepatitis B Virus May Contribute to Hepatocellular Carcinoma Risk: Evidence from an Updated Meta-Analysis

Background Studies focused on the correlation of mutations in the genome of Hepatitis B Virus (HBV) like Pre-S mutation, Basal Core promoter (BCP), Enhancer II (EnhII), especially Precore mutation, with the risk of hepatocellular carcinoma (HCC) have triggered stiff controversies. With an increasing number of studies in this field recently, we conducted this meta-analysis to appraise the correlations. Methods We searched the commonly used databases both in English and Chinese till February 1st, 2012. Meta-analysis was performed in fixed/random-effects models using STATA 10.0. Publication bias was examined through Eggers test and Beggs funnel plot. Results In total, 85 case-control studies were included involving 16745 HBV-infected patients, of whom 5781 had HCC. Statistically significant correlations were observed in Precore mutation G1896A (OR = 1.46, 95% confidence interval [CI] = 1.15–1.85, POR = 0.002), G1899A (OR = 3.13, 95%CI = 2.38–4.13, POR<0.001) and Pre-S mutation especially Pre-S1 deletion (OR = 2.94, 95%CI = 2.22 to 3.89) and Pre-S2 deletion (OR = 3.02, 95%CI = 2.03 to 4.50). Similar correlation existed between BCP double mutation A1762T/G1764A, T1753V, C1653T and HCC. In subgroup analysis, the Asians, genotype C or HBeAg positive patients with certain above mutations may be more susceptible to HCC. Besides, the mutations like G1896A and BCP double mutation may be associated with the progression of the liver diseases. Conclusions Precore mutation G1896A, G1899A, deletions in Pre-S region as well as the other commonly seen mutations correlated with the increased risk of HCC, especially in Asians and may predict the progression of the liver disease.

Ghrelin inhibit cell apoptosis in pancreatic β cell line HIT-T15 via mitogen-activated protein kinase/phosphoinositide 3-kinase pathways

Ghrelin stimulates growth hormone (GH) release and induces positive energy balances. Previous studies have reported that ghrelin inhibits apoptosis in several cell types but the precise underlying protective mechanisms in pancreatic beta cells are poorly understood. Therefore, we investigated which pathway was related with its anti-apoptotic effect in pancreatic beta cells. Exposure of HIT-T15 cells to ghrelin caused a rapid activation of MAPKs and Akt. Chemical inhibitors of MAPK and PI3K blocked the anti-apoptotic of ghrelin. Ghrelin also stimulated the mitochondrial pathways of apoptosis and it showed increased Bcl-2, decreased Bax, prevention cytochrome c release and inhibition of caspase-3 activation in pancreatic beta cell line HIT-T15. Our findings suggest that ghrelin may act as a survival factor that inhibits the apoptotics pathways, and the MAPKs, AKT pathways could be key roles in the apoptosis of pancreatic beta cells.

Genetic Variations in MicroRNA Processing Genes Are Associated with Susceptibility in Depression

MicroRNAs (miRNAs) are new prominent gene expression regulators that have critical roles in neural development by regulating synaptic functions, and miRNA biogenesis may play an important role in psychiatric disorders. Despite emerging evidences demonstrating that single-nucleotide polymorphisms in the miRNA processing genes were associated with cancer and cardiovascular disorders, evidences about association between variants of the genes and depression are lacking. This study aims to find the association between miRNA processing gene variants and depression. We genotyped three polymorphisms from three miRNA processing genes in a case-control study including 314 patients and 252 matched healthy controls. The high-resolution melting method was used to genotype the three loci. Frequencies of genotypes and alleles showed significant difference between patients with depression and healthy controls in DGCR8 rs3757 and AGO1 rs636832. An allele frequency was significantly higher in rs3757 and lower in rs636832, respectively. Variant allele of DGCR8 rs3757 was associated with increased risk of suicidal tendency and improvement response to antidepressant treatment, whereas the variant of AGO1 rs636832 showed decreased risk of suicidal tendency, suicidal behavior, and recurrence. Besides allele frequency showed significant difference when compared patients with remission to controls, no significant differences were found in GEMIN4 rs7813 between patients and healthy controls. DGCR8 rs3757 and AGO1 rs636832 were found to have significant association with depression, and GEMIN4 rs7813 did not affect susceptibility to depression. These observations suggested that miRNA processing polymorphisms may affect depression risk and treatment.

Quercetin attenuates airway inflammation and mucus production induced by cigarette smoke in rats

Mucus hypersecretion is a feature of many chronic airway diseases induced by cigarette smoke (CS), and evidence suggests that the antioxidant and anti-inflammatory flavonoid quercetin may protect against CS-induced respiratory pathology. In this study, the ability of quercetin to protect against CS-induced mucin expression was examined in vivo and in vitro. Quercetin or 0.2% Tween aqueous solution was administered intraperitoneally to rats,which were then exposed to CS for 28 days. Cell counts and pro-inflammatory cytokine levels were measured in bronchoalveolar lavage fluid (BALF). Lung tissue was examined for total glutathione (GSH) and total antioxidant capacity (T-AOC), histopathological lesions, goblet cell hyperplasia, epidermal growth factor receptor (EGFR) phosphorylation and NF-κB pathway activation. To complement these in vitro studies, human airway epithelial NCI-H292 cells were pretreated with quercetin and then exposed to cigarette smoke extract (CSE). Cell lysates were examined for Muc5ac expression, EGFR phosphorylation and NF-κB pathway activation. In vivo, quercetin pretreatment suppressed CS-induced goblet cell hyperplasia, inflammation, oxidative stress, EGFR phosphorylation and NF-κB pathway activation in rat lung. In vitro, quercetin pretreatment attenuated the CSE-induced Muc5ac expression, NF-κB activation and EGFR phosphorylation. Our results suggest that quercetin attenuates CS-induced mucin protein synthesis in rat lung, possibly by inhibiting oxidative stress and inflammation via a mechanism involving NF-κB pathway activation and EGFR phosphorylation. These findings suggest that quercetin has a potential for treating chronic airway diseases.

Association Between Promoter Variants of Interleukin-18 and Schizophrenia in a Han Chinese Population

An increasing amount of evidence suggests that interleukin-18 (IL-18) plays a pivotal role in the pathophysiology of schizophrenia. However, association between single nucleotide polymorphism of IL-18 and the risk of schizophrenia has not been clarified. This study examined whether two promoter polymorphisms -137 G/C (rs187238) and -607 C/A (rs1946518) of IL-18 were associated with schizophrenia and six clinical symptoms (disorder of perception, thought disorder, disturbance of emotion, disorder of behavior and volition, suicide action, and aggressive action) to provide data for screening high-risk Han Chinese individuals. Three hundred seventy-two schizophrenic patients and 353 healthy controls from a Han Chinese population were examined to assess their genotype and allele frequencies of the two promoter polymorphisms of IL-18. The genotype distributions in both patients and controls were within Hardy-Weinberg equilibrium. No significant differences were observed in the genotype or the allele frequencies of the two single-nucleotide polymorphisms between patients and controls. However, genotype frequencies of -607 C/A showed significant differences between patients and controls in the appearance of perception disorder (χ2 = 6.153, p = 0.046). A significant difference was detected in -137 G/C between patients and controls in the appearance of aggressive action (χ2 = 3.909, p = 0.048). In conclusion, IL-18 gene promoter polymorphisms may not contribute to the susceptibility of schizophrenia in a Han Chinese population, but two single-nucleotide polymorphisms, -137 G/C and -607 C/A, may play a role in the development of perception disorder and aggressive action, respectively.

Association of HLA-DP/DQ, STAT4 and IL-28B variants with HBV viral clearance in Tibetans and Uygurs in China

Several genome‐wide association studies have revealed that HLA‐DP/DQ, STAT4 and IL‐28B associated with liver diseases. But because of population heterogeneity, different races would have different causative polymorphisms. Therefore, in this study, we included Chinese Tibetans and Uygurs to examine the roles of these genes on HBV natural clearance.