Assessment of the effect of betaine on p16 and c-myc DNA methylation and mRNA expression in a chemical induced rat liver cancer model

<p>Abstract</p> <p>Background</p> <p>The development and progression of liver cancer may involve abnormal changes in DNA methylation, which lead to the activation of certain proto-oncogenes, such as <it>c-myc</it>, as well as the inactivation of certain tumor suppressors, such as <it>p16</it>. Betaine, as an active methyl-donor, maintains normal DNA methylation patterns. However, there are few investigations on the protective effect of betaine in hepatocarcinogenesis.</p> <p>Methods</p> <p>Four groups of rats were given diethylinitrosamine (DEN) and fed with AIN-93G diets supplemented with 0, 10, 20 or 40 g betaine/kg (model, 1%, 2%, and 4% betaine, respectively), while the control group, received no DEN, fed with AIN-93G diet. Eight or 15 weeks later, the expression of <it>p16 </it>and <it>c-myc </it>mRNA was examined by Real-time PCR (Q-PCR). The DNA methylation status within the <it>p16 </it>and <it>c-myc </it>promoter was analyzed using methylation-specific PCR.</p> <p>Results</p> <p>Compared with the model group, numbers and areas of glutathione S-transferase placental form (GST-p)-positive foci were decreased in the livers of the rats treated with betaine (<it>P < 0.05</it>). Although the frequency of <it>p16 </it>promoter methylation in livers of the four DEN-fed groups appeared to increase, there is no difference among these groups after 8 or 15 weeks (<it>P > 0.05</it>). Betaine supplementation attenuated the down-regulation of <it>p16 </it>and inhibited the up-regulation of <it>c-myc </it>induced by DEN in a dose-dependent manner (<it>P </it>< 0.01). Meanwhile, increases in levels of malondialdehyde (MDA) and glutathione S-transferase (GST) in model, 2% and 4% betaine groups were observed (<it>P < 0.05</it>). Finally, enhanced antioxidative capacity (T-AOC) was observed in both the 2% and 4% betaine groups.</p> <p>Conclusion</p> <p>Our data suggest that betaine attenuates DEN-induced damage in rat liver and reverses DEN-induced changes in mRNA levels.</p

Not Available

Not AvailableSeafood contamination with pathogenic Escherichia coli is a significant public health threat in developing countries. In this study, the prevalence of different pathogroups of E. coli was investigated in fresh seafood. A total of 78 samples comprising of finfish (41) and shellfish (37) were analyzed using multiple selective-enrichment-isolation protocols. From all samples, 639 E. coli were isolated and tested for the presence of pathogroup-specific virulence-associated genes by polymerase chain reaction (PCR). Based on the distribution of virulence genes, 118 isolates belonged to enterohemorrhagic E. coli (EHEC) group, 25 to enteropathogenic E. coli (EPEC), 20 to enterotoxigenic E. coli (ETEC), 16 to enteroaggregative E. coli (EAEC) and 1 to enteroinvasive E. coli (EIEC). Fifty-five samples of seafood, 29 finfish and 26 shellfish, were found contaminated with pathogenic E. coli. Among different enrichment broth-selective agar combinations used for the recovery of pathogenic E. coli from seafood, enrichment in Tryptone Phosphate (TP) broth followed by isolation on sorbitol MacConkey (SMAC) agar performed superior to others. The study highlights the importance of using selective isolation and genotyping protocols to identify human pathogenic E. coli in seafood in regions with extensive anthropogenic contamination.Not Availabl

Microsatellites as Agents of Adaptive Change: An RNA-Seq-Based Comparative Study of Transcriptomes from Five Helianthus Species

Mutations that provide environment-dependent selective advantages drive adaptive divergence among species. Many phenotypic differences among related species are more likely to result from gene expression divergence rather than from non-synonymous mutations. In this regard, cis-regulatory mutations play an important part in generating functionally significant variation. Some proposed mechanisms that explore the role of cis-regulatory mutations in gene expression divergence involve microsatellites. Microsatellites exhibit high mutation rates achieved through symmetric or asymmetric mutation processes and are abundant in both coding and non-coding regions in positions that could influence gene function and products. Here we tested the hypothesis that microsatellites contribute to gene expression divergence among species with 50 individuals from five closely related Helianthus species using an RNA-seq approach. Differential expression analyses of the transcriptomes revealed that genes containing microsatellites in non-coding regions (UTRs and introns) are more likely to be differentially expressed among species when compared to genes with microsatellites in the coding regions and transcripts lacking microsatellites. We detected a greater proportion of shared microsatellites in 5′UTRs and coding regions compared to 3′UTRs and non-coding transcripts among Helianthus spp. Furthermore, allele frequency differences measured by pairwise FST at single nucleotide polymorphisms (SNPs), indicate greater genetic divergence in transcripts containing microsatellites compared to those lacking microsatellites. A gene ontology (GO) analysis revealed that microsatellite-containing differentially expressed genes are significantly enriched for GO terms associated with regulation of transcription and transcription factor activity. Collectively, our study provides compelling evidence to support the role of microsatellites in gene expression divergence.Science, Faculty ofNon UBCBotany, Department ofReviewedFacult

γ′ fibrinogen levels as a biomarker of COVID-19 respiratory disease severity

Coronavirus disease 2019 (COVID-19) is characterized by a pro-inflammatory state associated with organ failure, thrombosis, and death. We investigated a novel inflammatory biomarker, γ′ fibrinogen (GPF), in 103 hospitalized patients with COVID-19 and 19 healthy controls. We found significant associations between GPF levels and the severity of COVID-19 as judged by blood oxygen saturation (SpO2). The mean level of GPF in the patients with COVID-19 was significantly higher than in controls (69.8 (95 % CI 64.8–74.8) mg/dL compared with 36.9 (95 % CI 31.4–42.4) mg/dL, p \u3c 0.0001), whereas C-reactive protein (CRP), lactate dehydrogenase (LDH), and total fibrinogen levels were not significantly different between groups. Mean GPF levels were significantly highest in patients with severe COVID-19 (SpO2 ≤ 93 %, GPF 75.2 (95 % CI 68.7–81.8) mg/dL), compared to mild/moderate COVID-19 (SpO2 \u3e 93 %, GPF 62.5 (95 % CI 55.0–70.0) mg/dL, p = 0.01, AUC of 0.68, 95 % CI 0.57–0.78; Youden\u27s index cutpoint 62.9 mg/dL, sensitivity 0.64, specificity 0.63). In contrast, CRP, interleukin-6, ferritin, LDH, D-dimers, and total fibrinogen had weaker associations with COVID-19 disease severity (all ROC curves with lower AUCs). Thus, GPF may be a useful inflammatory marker of COVID-19 respiratory disease severity