Histological changes, lipid metabolism, and oxidative and endoplasmic reticulum stress in the liver of laying hens exposed to cadmium concentrations.

The objective of this study was to determine the effects of cadmium (Cd) on histological changes, lipid metabolism, and oxidative and endoplasmic reticulum (ER) stress in the liver of layers. A total of 480 hens at 38 wk of age were randomly assigned in 5 groups that were fed a basal diet or basal diet supplemented with CdCl2 2.5H2O at 7.5, 15, 30, and 60 mg Cd/kg feed for 9 wk. The results showed that accumulation of Cd was the greatest in the kidney, followed by the liver, pancreas, and lung. Diet contaminated with 30 mg Cd/kg induced antioxidant defenses accompanied by the increase of the activities of antioxidant enzymes in the liver, while dietary supplementation with 60 mg Cd/kg decreased the antioxidant levels significantly (P < 0.05). Immunofluorescence assay showed Cd induced reactive oxygen species production and endoplasmic reticulum stress in hepatocytes. Exposure to 60 mg Cd/kg significantly upregulated the expression of cytochrome C, caspase 3, caspase 9, caspase 7, Grp78, and Chop (P < 0.05). Histopathology and quantitative real-time PCR results presented periportal fibrosis, bile duct hyperplasia, and periportal inflammatory cell infiltration in the liver accompanied by upregulating the expression of tumor necrosis factor-α, IL-6 and IL-10 in the 30- or 60-mg Cd/kg groups. Oil Red O staining and RT-qPCR results showed dietary supplementation with 7.5, 15, and 30 mg Cd/kg promoted the synthesis of lipid droplets and upregulated the expression of fatty acid synthase, while dietary supplementation with 60 mg Cd/kg attenuated the synthesis of lipid droplets and downregulated the expression of acyl-CoA oxidase 1, carnitine palmitoyltransferase-1, and perixisome proliferation-activated receptor α (P < 0.05). Besides, the expression of vitellogenin (VTG) II and microsomal triglyceride transfer protein were upregulated in the 7.5-mg Cd/kg group, and the expressions of apolipoprotein B, vitellogenin II, and apolipoprotein very-low-density lipoprotein-II were downregulated in the 30- and/or 60-mg Cd/kg groups (P < 0.05). Conclusively, although low-dose Cd exposure promoted the synthesis of lipids and lipoproteins in the liver, the increase of Cd exposure could trigger liver injury through inducing oxidative and endoplasmic reticulum stress and negatively affect lipid metabolism and yolk formation in laying hens.

Association between the -607 C > A polymorphism in interleukin-18 gene promoter with gastrointestinal cancer risk: a meta-analysis.

The interleukin-18 (IL-18) gene -607 C/A polymorphism has been reported to be associated with gastrointestinal cancer, but there are conflicting results from previous studies on said topic. Therefore, the aim of this meta-analysis is to derive a more precise estimation of the association between the -607 C/A polymorphism in the IL-18 gene and gastrointestinal cancer risk. Literature searches of PubMed, Google Scholar, and Web of Science databases were carried out in 2015. Five studies were assessed with a total of 1618 cases and 1155 healthy controls. When results from all eligible studies were pooled into the meta-analysis, we found significant association between the IL-18 gene -607 C/A polymorphism and gastrointestinal cancer risk (CC vs AA: OR = 0.93, 95%CI = 0.72- 1.20; CC vs CA: OR = 0.76, 95%CI = 0.62-0.92; dominant model: OR = 1.25, 95%CI = 1.03-1.50; recessive model: OR = 1.09, 95%CI = 0.87-1.37). In the subgroup analysis, significant associations between the -607 C/A polymorphism and gastrointestinal cancer risk were found in esophageal cancer. However, this polymorphism did not appear to have any influence on gastric cancer and colorectal cancer susceptibility. In conclusion, this meta-analysis suggests that the -607 C/A polymorphism in the IL-18 gene may be associated with susceptibility to esophageal cancer. Further studies with large sample sizes are needed to confirm these conclusions.

Critical evaluation of transcription factor Atf2 as a candidate modulator of alcohol preference in mouse and human populations.

In prior work, congenic strains carrying the DBA/2Igb (D2) region of chromosome 2 (Chr2) for alcohol preference were bred onto a C57BL/6Ibg (B6) background and as predicted were found to reduce voluntary consumption. Subsequently, interval-specific congenic recombinant strains (ISCRS) were generated and also tested. These ISCRS strains reduced the quantitative trait loci (QTL) interval to a comparatively small 3.4 Mb region. Here, we have exploited an integrative approach using both murine and human populations to critically evaluate candidate genes within this region. First, we used bioinformatics tools to search for genes relevant to alcohol preference within the QTL region. Second, we searched for single nucleotide polymorphisms (SNPs) within exons of every gene in this region. Third, we conducted follow-up microarray analyses to identify differentially expressed genes between the B6 and ISCRS strains in mice from each group. Fourth, we analyzed correlations between the expression level of candidate genes and phenotypes of alcohol preference in a large family of BXD recombinant inbred strains derived from B6 and D2. Finally, we evaluated SNP segregation in both BXD mouse strains and in humans who were heavy alcohol drinkers or non-drinkers. Among several potential candidate genes in this region, we identified activating transcription factor 2 (Atf2) as the most plausible gene that would influence alcohol preference. However, the candidacy of Atf2 was only weakly supported when we used a genetic network approach and by focused reanalysis of genome-wide association study data from European-American and African-American populations. Thus, we cannot conclude that Atf2 plays a role in the regulation of the QTL of mouse Chr2.