Dianwu Liu

Lysine 92 Amino Acid Residue of USP46, a Gene Associated with ‘Behavioral Despair’ in Mice, Influences the Deubiquitinating Enzyme Activity

Deubiquitinating enzymes (DUBs) regulate diverse cellular functions by their activity of cleaving ubiquitin from specific protein substrates. Ubiquitin-Specific Protease 46 (USP46) has recently been identified as a quantitative trait gene responsible for immobility in the tail suspension test and forced swimming test in mice. Mice with a lysine codon (Lys 92) deletion in USP46 exhibited loss of ‘behavioral despair’ under inescapable stresses in addition to abnormalities in circadian behavioral rhythms and the GABAergic system. However, whether this deletion affects enzyme activity is unknown. Here we show that USP46 has deubiquitinating enzyme activity detected by USP cleavage assay using GST-Ub52 as a model substrate. Interestingly, compared to wild type, the Lys 92 deletion mutant resulted in a decreased deubiquitinating enzyme activity of 27.04%. We also determined the relative expression levels of Usp46 in rat tissues using real-time RT-PCR. Usp46 mRNA was expressed in various tissues examined including brain, with the highest expression in spleen. In addition, like rat USP46, both human and mouse USP46 are active toward to the model substrate, indicating the USP cleavage assay is a simple method for testing the deubiquitinating enzyme activity of USP46. These results suggest that the Lys 92 deletion of USP46 could influence enzyme activity and thereby provide a molecular clue how the enzyme regulating the pathogenesis of mental illnesses.

Paraoxonase 1 polymorphisms L55M and Q192R were not risk factors for Parkinson's disease: a HuGE review and meta-analysis.

PURPOSE The Paraoxonase 1 (PON1) has been studied as a potential candidate gene for Parkinsons disease risk, but direct evidence from genetic association studies remains inconclusive. We performed a meta-analysis pooling data from all relevant studies in order to determine the effects of two PON 1 polymorphisms (L55M and Q192R) on Parkinsons disease. METHODS We applied a random effects to combine odds ratio (OR) and 95% confidence intervals. Q statistic was used to evaluate the homogeneity, and Eggers test and Funnel plot were used to assess publication bias. In secondary analyses, we examined dominant and recessive models as well. RESULTS Concerning the PON1 L55M polymorphism, we identified 9 eligible studies (a total of 2582 cases and 3997 controls). The random effects pooled OR was OR=1.29, (0.90, 1.84). Concerning the Q192R polymorphism, we identified 7 eligible studies (a total of 2582 cases and 3997 controls). The random effects pooled OR was OR=1.08(0.81, 1.43). Analysis with dominant and recessive genetic models yielded the same inferences as genotype-based comparisons for both of the two polymorphisms. CONCLUSION The results of this meta-analysis suggested that both PON1 L55M and Q192R were not responsible for PD.

HLA-DR polymorphism and primary biliary cirrhosis: evidence from a meta-analysis.

BACKGROUND AND AIMS We undertook this study to review and quantitatively analyze the association between human leukocyte antigen (HLA) DR polymorphisms and susceptibility of primary biliary cirrhosis (PBC). METHODS All relevant publications on the association between HLA-DR polymorphisms and PBC were searched through June 2013. Odds ratios (OR) and confidence intervals (CI) for the comparisons between case and control group were calculated. Statistical analysis was performed using Stata 11.0 software. RESULTS Nineteen articles (or 20 studies including the substudies) were identified. For DR*7 allele, the ORs (95% CIs) were 1.530 (1.310, 1.788), 1.757 (1.285, 2.403) and 1.495 (1.211, 1.845) in overall, Asian and European populations, respectively. For DR*8 alleles, the ORs (95% CIs) were 3.158 (1.822, 5.475), 2.803 (2.420, 3.247) and 3.056 (2.573, 3.629) in Asian, American and European subgroups, respectively. The subgroup analysis for DR*11 and DR*13 showed a significant association in Asian and European population. For DR*12 and *15 alleles, the overall ORs (95% CIs) were 0.551 (0.404, 0.753) and 0.721 (0.607, 0.857). However, in subgroup analysis for DR*12 allele, the association was only found in Asian population. In addition, statistical significance exists in American and European populations in the subgroup analysis for DR*15 allele. CONCLUSION Our meta-analysis suggested that HLA-DR *7 and *8 allele polymorphisms contributed to the susceptibility of PBC, whereas DR*11, *12, *13 and *15 allele polymorphisms are protective factors in certain population.

IL28B rs12980275 variant as a predictor of sustained virologic response to pegylated-interferon and ribavirin in chronic hepatitis C patients: A systematic review and meta-analysis.

BACKGROUND AND OBJECTIVE The IL-28B rs12979860 CC and rs8099917 TT genotypes were proved to be predictor for pegylated-interferon (PEG-IFN)/ribavirin (RBV)-treated hepatitis C virus (HCV) patients. However, there were no identical conclusions on rs12980275 polymorphism. Our aim is to perform a meta-analysis in order to determine the association between rs12980275 polymorphism of IL28B and the sustain viral response (SVR) of HCV patients with PEG-IFN/RBV therapy. METHODS Studies were retrieved from PubMed and Chinese China National Knowledge Infrastructure (CNKI). Data were extracted by two investigators and analyzed using Stata 11.0 software. RESULTS Sixteen articles, containing 19 independent studies were included in the analysis. The results showed that patients with AA genotype of rs12980275 achieved higher SVR than patients with AG/GG genotypes. The overall OR (95% CI) was 3.118 (2.146, 4.529). In subgroup analysis by ethnicity, the ORs (95% CIs) were 3.084 (1.454, 6.542) and 2.736 (1.863, 4.018) in Asian and Caucasian population, respectively. Another subgroup analysis by HCV genotype, the ORs (95% CIs) were 3.976 (2.568, 6.158), 1.462 (0.504, 4.240) and 1.489 (0.916, 2.421) in patients with HCV genotype 1/4, mix genotype, and HCV genotype 2/3, respectively. CONCLUSION AA genotype of rs12980275 was a predictive factor for SVR in HCV patients with PEG-IFN/RBV treatment, especially in HCV genotype 1/4.

Genotoxicity Evaluation of Irrigative Wastewater from Shijiazhuang City in China

In the present study, the wastewater sample collected from the Dongming discharging river in Shijiazhuang city was analysed using both chemical analysis and biological assays including the Salmonella mutagenicity test, micronucleus test and single-cell gel electrophoresis. Chemical analysis of the sample was performed using gas chromatography mass spectrometry and inductively coupled plasma mass spectrometry. The Salmonella mutagenicity test was performed on Salmonella typhimurium TA97, TA98, TA100 and TA102 strains with and without S9 mixture. The mice received the wastewater in natura through drinking water at concentrations of 25%, 50%, and 100%. One group of mice was exposed for 2 consecutive days, and the other group of mice was exposed for 15 consecutive days. To establish the levels of primary DNA damage, single-cell gel electrophoresis was performed on treated mouse liver cell. The concentrations of chromium and lead in the sample exceeded the national standard (GB20922-2007) by 0.78 and 0.43-fold, respectively. More than 30 organic compounds were detected, and some of the detected compounds were mutagens, carcinogens and environmental endocrine disrupters. A positive response for Salmonella typhimurium TA98 strain was observed. Mouse exposure via drinking water containing 50% and 100% of wastewater for 15 consecutive days caused a significant increase of MN frequencies in a dose-response manner. Mouse exposure via drinking water containing 50% and 100% of wastewater for 15 consecutive days caused a significant increase of the Olive tail moments in a dose-response manner. All the results indicated that the sample from the Dongming discharging river in Shijiazhuang city exhibited genotoxicity and might pose harmful effects on the local residents.

Evidence from enzymatic and meta-analyses does not support a direct association between USP26 gene variants and male infertility.

Do men who carry mutations in USP26 have an increased risk of infertility? The association between mutations in USP26 gene and male infertility has been studied intensively. However, the results from different groups are controversial. In particular, biological function of the mutant proteins remains to be elucidated. In this study, we conducted a USP cleavage assay and a meta‐analysis of the published literature (up to 31 May 2013) to evaluate the impact of five frequent mutations (NM_031907.1: c.363_364insACA, c.494T>C, c.1423C>T, c.1090C>T, c.1737G>A) on enzymatic activity of the USP26 and to assess the strength of the association between those mutations and male infertility. The USP cleavage assay showed that those mutations do not affect USP26 enzymatic activity. Moreover, the results of meta‐analysis of ten case‐control studies (in total 1716 patients and 2597 controls) revealed no significant association (P > 0.05) between USP26 mutations and male infertility. The pooled ORs were 1.58 (95% CI: 0.81, 3.10) for cluster mutations (c.363_364insACA, c.494T>C, c.1423C>T), 1.60 (95% CI: 0.93, 2.74) for c.1090 C>T and 2.64 (95% CI: 0.97, 7.20) for c.1737 G>A. Evidence from both enzymatic and meta‐analyses does not support a direct association between USP26 variants and male infertility. Further research is necessary to study the biological function of USP26, which may provide clues as to the regulation of androgen receptor signalling.

Mortality analysis on wastewater exposure in Shijiazhuang, Hebei, China, from 2007 to 2011

The study investigated the age-adjusted mortality rate and disease odds among deceased residents living in areas exposed to wastewater and cleanwater from 2007 to 2011, in Shijiazhuang, China. Mortality data for eight villages exposed to wastewater and 16 villages not exposed to wastewater were collected and crosschecked from multiple sources. Overall mean age-adjusted mortality rate for wastewater areas was 798/105 (95 % Confidence Interval (CI) = ± 68), insignificantly higher than the mean mortality rate for cleanwater area, 726/105 (95 % CI = ± 46), p > 0.05. Malignant neoplasms and respiratory mortality and disease odds were higher in wastewater areas than in cleanwater areas, OR = 1.7 (95 % CI = 1.3–2.2, p < 0.01) and OR = 1.9 (95 % CI = 1.1–3.4, p < 0.05), respectively. Wastewater area mortality and disease odds for Lung and Stomach cancers after adjustments were OR = 1.6 (95 % CI = 1.1–2.4, p < 0.05) and OR = 1.8 (95 % CI = 1.2–2.7, p < 0.01), respectively, significantly higher than those of cleanwater areas. There is a possibility that exposure to wastewater might be associated with cancer and respiratory disease mortality. The study recommends that the use of wastewater be limited, discouraged, or discontinued.

eRF3b, a Biomarker for Hepatocellular Carcinoma, Influences Cell Cycle and Phosphoralation Status of 4E-BP1

Background Hepatitis B virus (HBV) infection and its sequelae are now recognized as serious problems globally. Our aime is to screen hepatocellular carcinoma (HCC) from chronic hepatitis B (CHB) and identify the characteristics of proteins involved. Methodology/Principal Findings We affinity-purified sample serum with weak cation-exchange (WCX) magnetic beads and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) analysis to search for potential markers. The 4210 Da protein, which differed substantially between HCC and CHB isolates, was later identified to be eukaryotic peptide chain release factor GTP-binding subunit eRF3b. Further research showed that eRF3b/GSPT2 was positively expressed in liver tissues. GSPT2 mRNA was, however differentially expressed in blood. Compared with normal controls, the relative expression of GSPT2/18s rRNA was higher in CHB patients than in patients with either LC or HCC (P = 0.035 for CHB vs. LC; P = 0.020 for CHB vs. HCC). The data of further research showed that eRF3b/GSPT2 promoted the entrance of the HepG2 cells into the S-phase and that one of the substrates of the mTOR kinase, 4E-BP1, was hyperphosphorylated in eRF3b-overexpressing HepG2 cells. Conclusions Overall, the differentially expressed protein eRF3b, which was discovered as a biomarker for HCC, could change the cell cycle and influence the phosphorylation status of 4E-BP1 on Ser65 in HepG2.

Association between PNPLA3 gene polymorphisms and risk of hepatitis B virus-related hepatocellular carcinoma in Han population in China:a case-control study

Abstract Background and aim: Several recent studies showed that the genetic polymorphisms in the PNPLA3 region (rs738408, rs738409, rs2294918, rs2294919 and rs2281135) were with related to various kinds of liver diseases. We analyzed the five single-nucleotide polymorphisms (SNPs) for major HBV outcomes in Han Chinese. Methods: A total of 2410 samples were involved and peripheral blood samples were collected in this study. The SNPs in the PNPLA3 region were genotyped by using Matrix-assisted laser desorption/ionization time of flight mass spectrometry. Results: Our study indicated the clear relationship between the PNPLA3 rs2294918, rs2294919 and HBV-related HCC after control for the effects of sex, drinking and smoking. Health subjects with the PNPLA3 rs2294919 TC genotype would have a 0.605 (95% CI: 0.413, 0.886; p = .010) times lower odds of having HCC, and those with the rs2294918 AG genotype would have a 1.872 (95% CI: 1.256, 2.792; p = .002) times higher odds of having HCC, whereas the values of sex, age, drinking and smoking were fixed. In addition, CA haplotype of the haplotype block of rs738409 and rs2281135 was also associated with HBV-related HCC. Conclusions: Our study suggested that PNPLA3 loci (rs2294918, rs2294919) were associated with HBV-related HCC in Han Chinese.

Correlation between polymorphisms in DNA mismatch repair genes and the risk of primary hepatocellular carcinoma for the Han population in northern China

Abstract Purpose: This study investigated correlations between polymorphisms in DNA mismatch repair (MMR) genes and the risk of primary hepatocellular carcinoma (PHC). Methods. Single nucleotide polymorphisms (SNPs) in the DNA MMR genes MLH3 (rs175080), PMS1 (rs5742933), PMS2 (rs1059060), MSH3 (rs26279), MSH5 (rs1150793, rs2075789) and MSH6 (rs1042821) were detected using the SNaPshot method in 250 PHC cases and in 308 patients without PHC in the Han population in northern China. Results. The AA genotype in MLH3 (rs175080) increased the risk of PHC (odds ratio [OR] = 3.424; 95% confidence interval [CI]: 1.097–10.689). The AG and GG genotypes in MSH3 (rs26279) increased the risk of PHC (OR: 1.644 and 3.300; 95% CI: 1.112–2.428 and 1.765–6.168, respectively). The AA genotype in MSH5 (rs2075789) increased the risk of PHC (OR: 9.229; 95% CI: 1.174–72.535). The CT genotype in MSH6 (rs1042821) reduced the risk of PHC (OR: 0.629; 95% CI: 0.428–0.924). Conclusions. Our study suggests that polymorphisms in MLH3 (rs175080), MSH3 (rs26279), MSH5 (rs2075789) and MSH6 (rs1042821) may be independent risk factors for PHC.