Toxicity and metabolism of 3-bromopyruvate in Caenorhabditis elegans.

In this study, we aimed to evaluate the toxic effects, changes in life span, and expression of various metabolism-related genes in Caenorhabditis elegans, using RNA interference (RNAi) and mutant strains, after 3-bromopyruvate (3-BrPA) treatment. C. elegans was treated with various concentrations of 3-BrPA on nematode growth medium (NGM) plates, and their survival was monitored every 24 h. The expression of genes related to metabolism was measured by the real-time fluorescent quantitative polymerase chain reaction (qPCR). Nematode survival in the presence of 3-BrPA was also studied after silencing three hexokinase (HK) genes. The average life span of C. elegans cultured on NGM with 3-BrPA was shortened to 5.7 d compared with 7.7 d in the control group. hxk-1, hxk-2, and hxk-3 were overexpressed after the treatment with 3-BrPA. After successfully interfering hxk-1, hxk-2, and hxk-3, the 50% lethal concentration (LC50) of all mutant nematodes decreased with 3-BrPA treatment for 24 h compared with that of the control. All the cyp35 genes tested were overexpressed, except cyp-35B3. The induction of cyp-35A1 expression was most obvious. The LC50 values of the mutant strains cyp-35A1, cyp-35A2, cyp-35A4, cyp-35B3, and cyp-35C1 were lower than that of the control. Thus, the toxicity of 3-BrPA is closely related to its effect on hexokinase metabolism in nematodes, and the cyp-35 family plays a key role in the metabolism of 3-BrPA.

Association between TNFA Gene Polymorphisms and Helicobacter pylori Infection: A Meta-Analysis.

BACKGROUND: Several host genetic factors are thought to affect susceptibility to Helicobacter pylori infection-related diseases, including tumor necrosis factor (TNF)-α. Previous studies have evaluated the association between TNFA gene polymorphisms and H. pylori infection, but the results were inconclusive. We conducted this meta-analysis to clarify the association between TNFA polymorphisms and H. pylori infection. METHODS: Published literature within PubMed, Embase, and the Cochrane Library were used in our meta-analysis. Data were analyzed with the Stata13.1 software package using pooled odds ratios (ORs) with 95% confidence intervals (CI). RESULTS: A total of 24 studies were included in our study. The TNFA -308G>A polymorphism was associated with decreasing H. pylori infection (AA vs. AG+GG, OR = 0.64, 95% CI = 0.43-0.97; AA vs. GG, OR = 0.64, 95% CI = 0.43-0.97). A significantly decreased risk was also found for -1031T>C polymorphism (CC vs. CT+TT, OR = 0.61, 95% CI = 0.44-0.84). -863C>A polymorphism was associated with increasing risk of H. pylori infection (AA+AC vs. CC, OR = 1.47, 95% CI = 1.16-1.86; A allele vs. C allele, OR = 1.40, 95% CI = 1.14-1.72). There was no significant association between -857C>T polymorphism and H. pylori infection. When stratified analysis was conducted on H. pylori infection detection methods, -857C>T and -863C>A polymorphisms were associated with H. pylori infection for the non-ELISA subgroup. When stratified for ethnicity or study design, -863C>A significantly increased the risk and -1031T>C decreased the risk for the Asian subgroup and hospital-based subgroup. CONCLUSION: Results of our meta-analysis demonstrate that TNFA -308G>A and -1031 T>C polymorphisms may be protective factors against H. pylori infection, and -863C>A may be a risk factor, especially in Asian populations. Further studies with larger sample sizes are required to validate these results.

The Analysis of Gene Expression on Fertility Decline in Caenorhabditis elegans after the Treatment with 5-Fluorouracil.

BACKGROUND: 5-Fluorouracil could lead to a decline in fertility in Caenorhabditis elegans. The aim of this study was to describe the mechanisms underlying such an altered fertility phenotype and to illustrate the specific genes and pathways that are involved in the related phenotypic changes in C. elegans. METHODS: We isolated total RNA from the samples and used a new method called Digital Gene Expression (DGE), which can rapidly identify genes with altered transcript levels. The random genes were confirmed by real-time RT-PCR. RESULTS: We analyzed the results of two methods to draw conclusions based on a comparison between C. elegans and other harmful parasites. Compared with controls, 1147 genes were up-regulated, and 1067 were down-regulated. Overall, 101 up-regulated genes had a log2 ratio higher than 8, whereas the log2 ratio of 141 down-regulated genes was higher than 8. After mapping to the reference database, 4 pathways were confirmed to be involved in this phenomenon, with statistically significant participation from 19 genes. CONCLUSION: For the first time, the transcript sequence of 5-Fu-treated worms and controls was detected. We found that 4 possible pathways, i.e., ECM-receptor interaction pathway, TGF-beta signaling pathway, Focal adhesion and Hypertrophic cardiomyopathy, may be involved in the number decline in the embryos of C. elegans. Specifically, the ECM-receptor interaction pathway and Focal adhesion may be very important pathways that alter the reproduction of C. elegans.