Dietary Ribonucleic Acid Suppresses Inflammation of Adipose Tissue and Improves Glucose Intolerance That Is Mediated by Immune Cells in C57BL/6 Mice Fed a High-Fat Diet

Suppression of Ehrlich ascites tumor cell proliferation via G1 arrest induced by dietary nucleic acid-derived nucleosides

The nucleic acids found in food play a crucial role in maintaining various bodily functions. This study investigated the potential anticancer effects of dietary nucleic acids, an area that is still not fully understood. By utilizing an in vivo mouse model and an in vitro cell model, we discovered an anti-proliferative impact of RNA in both systems. DNA exhibited anti-proliferative effects in the mouse model, while this phenomenon wasn't observed in the in vitro cell model using Ehrlich ascites tumor (EAT) cells. Conversely, DNA hydrolysate demonstrated distinct anti-proliferative effects in EAT cells, suggesting that nucleotides or nucleosides generated during nucleic acid digestion act as active constituents. Furthermore, we examined various nucleosides and two sodium-independent equilibrative nucleoside transporter inhibitors (ENTs), identifying guanosine and 2'-deoxyguanosine as pivotal in the anti-proliferative effect. We also found that the anti-proliferation activity with both nucleosides was suppressed by the treatment of dipyridamole, a non-selective inhibitor for ENT1 and ENT2, but not nitrobenzylthioinosine, a low inhibitor for ENT2. The uptake of these compounds into cells is likely facilitated by ENT2. These nucleotides impeded the progression of cancer cells from the G1 phase to the S phase in the cell cycle. Another significant finding is the increased expression of CCAAT/enhancer-binding protein (C/EBPβ) induced by guanosine and 2'-deoxyguanosine. Furthermore, immunostaining revealed that C/EBPβ diffuses into the nucleus, indicating its presence. This suggests that guanosine or 2-deoxyguanosine induces G1 arrest in cancer cells via the activation of C/EBPβ. Encouraged by these promising results, guanosine and 2'-deoxyguanosine show potential applications in cancer prevention.

Perinatal and Early-Life Nutrition, Epigenetics, and Allergy

Epidemiological studies have shown a dramatic increase in the incidence and the prevalence of allergic diseases over the last several decades. Environmental triggers including risk factors (e.g., pollution), the loss of rural living conditions (e.g., farming conditions), and nutritional status (e.g., maternal, breastfeeding) are considered major contributors to this increase. The influences of these environmental factors are thought to be mediated by epigenetic mechanisms which are heritable, reversible, and biologically relevant biochemical modifications of the chromatin carrying the genetic information without changing the nucleotide sequence of the genome. An important feature characterizing epigenetically-mediated processes is the existence of a time frame where the induced effects are the strongest and therefore most crucial. This period between conception, pregnancy, and the first years of life (e.g., first 1000 days) is considered the optimal time for environmental factors, such as nutrition, to exert their beneficial epigenetic effects. In the current review, we discussed the impact of the exposure to bacteria, viruses, parasites, fungal components, microbiome metabolites, and specific nutritional components (e.g., polyunsaturated fatty acids (PUFA), vitamins, plant- and animal-derived microRNAs, breast milk) on the epigenetic patterns related to allergic manifestations. We gave insight into the epigenetic signature of bioactive milk components and the effects of specific nutrition on neonatal T cell development. Several lines of evidence suggest that atypical metabolic reprogramming induced by extrinsic factors such as allergens, viruses, pollutants, diet, or microbiome might drive cellular metabolic dysfunctions and defective immune responses in allergic disease. Therefore, we described the current knowledge on the relationship between immunometabolism and allergy mediated by epigenetic mechanisms. The knowledge as presented will give insight into epigenetic changes and the potential of maternal and post-natal nutrition on the development of allergic disease.

Vitamin A and Retinoic Acid Exhibit Protective Effects on Necrotizing Enterocolitis by Regulating Intestinal Flora and Enhancing the Intestinal Epithelial Barrier

BACKGROUND

Exaggerated inflammation that characterizes necrotizing enterocolitis (NEC) is caused by the invasion of pathogens through an immature intestinal barrier. Vitamin A (VA) and retinoic acid (RA) play important roles in the growth of epithelial tissue and in modulating immune function.

OBJECTIVE

To investigate the roles of VA and RA in the development of NEC.

METHODS

Levels of serum retinol in patients and in a NEC mouse model were detected with high-performance liquid chromatography. Bacterial communities of NEC mice treated with VA or PBS were detected by high-throughput sequencing. In vitro and in vivo, levels of inflammatory factors were measured by ELISA and RT-PCR, and expression levels of claudin-1, occludin, and ZO-1 were detected by Western blotting. Transepithelial electrical resistance (TEER) was measured in Caco-2 cell monolayers.

RESULTS

The level of VA in the NEC patients was lower than in the control patients. In the NEC mice that were treated with VA versus PBS, the proportion of Escherichia-Shigella was lower, while the abundance of Bacteroides was markedly higher. Both in vivo and in vitro, the levels of inflammatory factors were significantly reduced, while the expression levels of claudin-1, occludin, and ZO-1 were increased, after the VA and RA treatments. Meanwhile, TEER was increased and lipopolysaccharide-induced damage was reduced in Caco-2 cell monolayers after RA treatment.

CONCLUSIONS

These results suggest that VA may regulate intestinal flora, alleviate inflammatory reactions, and enhance the intestinal epithelial barrier in NEC. Thus, VA may be an effective drug for providing protection against NEC in newborns.

A high-quality annotated transcriptome of swine peripheral blood

Background

High throughput gene expression profiling assays of peripheral blood are widely used in biomedicine, as well as in animal genetics and physiology research. Accurate, comprehensive, and precise interpretation of such high throughput assays relies on well-characterized reference genomes and/or transcriptomes. However, neither the reference genome nor the peripheral blood transcriptome of the pig have been sufficiently assembled and annotated to support such profiling assays in this emerging biomedical model organism. We aimed to assemble published and novel RNA-seq data to provide a comprehensive, well-annotated blood transcriptome for pigs by integrating a de novo assembly with a genome-guided assembly.

Results

A de novo and a genome-guided transcriptome of porcine whole peripheral blood was assembled with ~162 million pairs of paired-end and ~183 million single-end, trimmed and normalized Illumina RNA-seq reads (~6 billion initial reads from 146 RNA-seq libraries) from five independent studies by using the Trinity and Cufflinks software, respectively. We then removed putative transcripts (PTs) of low confidence from both assemblies and merged the remaining PTs into an integrated transcriptome consisting of 132,928 PTs, with 126,225 (~95%) PTs from the de novo assembly and more than 91% of PTs spliced. In the integrated transcriptome, ~90% and 63% of PTs had significant sequence similarity to sequences in the NCBI NT and NR databases, respectively; 68,754 (~52%) PTs were annotated with 15,965 unique gene ontology (GO) terms; and 7618 PTs annotated with Enzyme Commission codes were assigned to 134 pathways curated by the Kyoto Encyclopedia of Genes and Genomes (KEGG). Full exon-intron junctions of 17,528 PTs were validated by PacBio IsoSeq full-length cDNA reads from 3 other porcine tissues, NCBI pig RefSeq mRNAs and transcripts from Ensembl Sscrofa10.2 annotation. Completeness of the 5’ termini of 37,569 PTs was validated by public cap analysis of gene expression (CAGE) data. By comparison to the Ensembl transcripts, we found that (1) the deduced precursors of 54,402 PTs shared at least one intron or exon with those of 18,437 Ensembl transcripts; (2) 12,262 PTs had both longer 5’ and 3’ termini than their maximally overlapping Ensembl transcripts; and (3) 41,838 spliced PTs were totally missing from the Sscrofa10.2 annotation. Similar results were obtained when the PTs were compared to the pig NCBI RefSeq mRNA collection.

Conclusions

We built, validated and annotated a comprehensive porcine blood transcriptome with significant improvement over the annotation of Ensembl Sscrofa10.2 and the pig NCBI RefSeq mRNAs, and laid a foundation for blood-based high throughput transcriptomic assays in pigs and for advancing annotation of the pig genome.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-017-3863-7) contains supplementary material, which is available to authorized users.

Protective Effects of Hydrolyzed Nucleoproteins from Salmon Milt against Ethanol-Induced Liver Injury in Rats

Dietary nucleotides play a role in maintaining the immune responses of both animals and humans. Oral administration of nucleic acids from salmon milt have physiological functions in the cellular metabolism, proliferation, differentiation, and apoptosis of human small intestinal epithelial cells. In this study, we examined the effects of DNA-rich nucleic acids prepared from salmon milt (DNSM) on the development of liver fibrosis in an in vivo ethanol-carbon tetrachloride cirrhosis model. Plasma aspartate transaminase and alanine transaminase were significantly less active in the DNSM-treated group than in the ethanol plus carbon tetrachloride (CCl₄)-treated group. Collagen accumulation in the liver and hepatic necrosis were observed histologically in ethanol plus CCl₄-treated rats; however, DNSM-treatment fully protected rats against ethanol plus CCl₄-induced liver fibrosis and necrosis. Furthermore, we examined whether DNSM had a preventive effect against alcohol-induced liver injury by regulating the cytochrome p450 2E1 (CYP2E1)-mediated oxidative stress pathway in an in vivo model. In this model, CYP2E1 activity in ethanol plus CCl₄-treated rats increased significantly, but DNSM-treatment suppressed the enzyme's activity and reduced intracellular thiobarbituric acid reactive substances (TBARS) levels. Furthermore, the hepatocytes treated with 100 mM ethanol induced an increase in cell death and were not restored to the control levels when treated with DNSM, suggesting that digestive products of DNSM are effective for the prevention of alcohol-induced liver injury. Deoxyadenosine suppressed the ethanol-induced increase in cell death and increased the activity of alcohol dehydrogenase. These results suggest that DNSM treatment represents a novel tool for the prevention of alcohol-induced liver injury.

The Efficacy of Oral Nutritional Intervention in Malnourished Cancer Patients: a Systemic Review

Cancer is currently a leading cause of deaths worldwide and the number of new cases is growing rapidly in both, developed and developing countries. Nutritional management during and after cancer treatment affects treatment efficacy and patient quality of life (QOL). This review systemically examined the effect of oral nutritional interventions on nutritional and clinical outcomes in cancer patients. We especially focused on outcomes such as nutritional status indices, immune-associated biochemical markers, and QOL assessments to provide insights on the applicability of different outcomes. A total of 28 papers were selected for systematic review. The nutritional composition of oral nutritional supplements (ONS), outcome measures, and efficacy of the oral nutritional interventions were summarized and discussed. Most ONS contain 1 or more functional components in addition to basic nutrients. Each study used various outcome measures and significant efficacy was observed for a limited number of measures. Nutritional status indices, QOL measures, and the duration of hospital stay improved in about 40% of the studies. One or more markers of immune function and inflammatory responses were improved by ONS in 65% of the selected studies. These results suggest that appropriate use of ONS may be an ideal way to improve treatment efficacy; however, additional intervention trials are required to confirm these findings.