scholarly journals RNAseq studies reveal distinct transcriptional response to vitamin A deficiency in small intestine versus colon, uncovering novel vitamin A-regulated genes

2019 ◽  
Author(s):  
Zhi Chai ◽  
Yafei Lyu ◽  
Qiuyan Chen ◽  
Cheng-Hsin Wei ◽  
Lindsay M. Snyder ◽  
...  

AbstractVitamin A (VA) deficiency remains prevalent in resource limited countries, affecting over 250 million preschool aged children. Vitamin A deficiency is associated with reduced intestinal barrier function and increased risk of mortality due to mucosal infection. Using Citrobacter rodentium (C. rodentium) infection in mice as a model for diarrheal diseases in humans, previous reports showed reduced pathogen clearance and survival in vitamin A deficient (VAD) mice compared to their vitamin A sufficient (VAS) counterparts.ObjectivesTo characterize and compare the impact of preexisting VA deficiency on gene expression patterns in the small intestine (SI) and the colon, and to discover novel target genes in VA-related biological pathways.MethodsVAD mice were generated by feeding VAD diet to pregnant C57/BL6 dams and their post-weaning offspring. RNAseq were performed using the total mRNAs extracted from SI and colon. Differentially Expressed Gene (DEG), Gene Ontology (GO) enrichment, and Weighted Gene Co-expression Network Analysis (WGCNA) were performed to characterize expression and co-expression patterns.ResultsDEGs compared between VAS and VAD groups detected 49 SI and 94 colon genes. By GO information, SI DEGs were significantly enriched in categories relevant to retinoid metabolic process, molecule binding, and immune function. Immunity related pathways, including “humoral immune response” and “complement activation” were positively associated with VA in SI. Three co-expression modules showed significant correlation with VA status in SI; these modules contained four known retinoic acid targets. In addition, other SI genes of interest (e.g. Mbl2, Cxcl14, and Nr0b2) in these modules were suggested as new candidate genes regulated by VA. Furthermore, our analysis showed that markers of two cell types in SI, mast cells and Tuft cells, were significantly altered by VA status. In colon, “cell division” was the only enriched category and was negatively associated with VA. Thus, comparison of co-expression modules between SI and colon indicated distinct networks under the regulation of dietary VA and suggest that preexisting VAD could have a significant impact on the host response to a variety of disease conditions.

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Zhi Chai ◽  
Yafei Lyu ◽  
Qiuyan Chen ◽  
Cheng-Hsin Wei ◽  
Lindsay Snyder ◽  
...  

Abstract Objectives To characterize and compare the impact of vitamin A (VA) deficiency on gene expression patterns in the small intestine (SI) and the colon, and to discover novel target genes in VA-related biological pathways. Methods vitamin A deficient (VAD) mice were generated by feeding VAD diet to pregnant C57/BL6 dams and their post-weaning offspring. Total mRNA extracted from SI and colon were sequenced using Illumina HiSeq 2500 platform. Differentially Expressed Gene (DEG), Gene Ontology (GO) enrichment, and Weighted Gene Co-expression Network Analysis (WGCNA) were performed to characterize expression patterns and co-expression patterns. Results The comparison between vitamin A sufficient (VAS) and VAD groups detected 49 and 94 DEGs in SI and colon, respectively. According to GO information, DEGs in the SI demonstrated significant enrichment in categories relevant to retinoid metabolic process, molecule binding, and immune function. Immunity related pathways, such as “humoral immune response” and “complement activation,” were positively associated with VA in SI. On the contrary, in colon, “cell division” was the only enriched category and was negatively associated with VA. WGCNA identified modules significantly correlated with VA status in SI and in colon. One of those modules contained five known retinoic acid targets. Therefore we have prioritized the other module members (e.g., Mbl2, Mmp9, Mmp13, Cxcl14 and Pkd1l2) to be investigated as candidate genes regulated by VA. Comparison of co-expression modules between SI and colon indicated distinct VA effects on these two organs. Conclusions The results show that VA deficiency alters the gene expression profiles in SI and colon quite differently. Some immune-related genes (Mbl2, Mmp9, Mmp13, Cxcl14 and Pkd1l2) may be novel targets under the control of VA in SI. Funding Sources NIH training grant and NIH research grant. Supporting Tables, Images and/or Graphs


2019 ◽  
Vol 20 (7) ◽  
pp. 666-673 ◽  
Author(s):  
Sujuan Ding ◽  
Gang Liu ◽  
Hongmei Jiang ◽  
Jun Fang

The rapid self-renewal of intestinal epithelial cells enhances intestinal function, promotes the nutritional needs of animals and strengthens intestinal barrier function to resist the invasion of foreign pathogens. MicroRNAs (miRNAs) are a class of short-chain, non-coding RNAs that regulate stem cell proliferation and differentiation by down-regulating hundreds of conserved target genes after transcription via seed pairing to the 3' untranslated regions. Numerous studies have shown that miRNAs can improve intestinal function by participating in the proliferation and differentiation of different cell populations in the intestine. In addition, miRNAs also contribute to disease regulation and therefore not only play a vital role in the gastrointestinal disease management but also act as blood or tissue biomarkers of disease. As changes to the levels of miRNAs can change cell fates, miRNA-mediated gene regulation can be used to update therapeutic strategies and approaches to disease treatment.


2015 ◽  
Vol 129 (7) ◽  
pp. 529-531 ◽  
Author(s):  
Neil A. Mabbott

A new study by Man and colleagues provides further insight into the effects of aging on small intestinal barrier function in humans. Here, their findings are briefly summarised and the wider implications discussed.


2018 ◽  
Vol 104 (3) ◽  
pp. 217-226 ◽  
Author(s):  

BackgroundBiannual vitamin A supplementation is a well-established survival tool for preschool children 6 months and older in vitamin A deficient populations but this schedule misses the opportunity to intervene on most young infant deaths. Randomised trials of neonatal vitamin A supplementation (NVAS) in the first few days of life to assess its impact on under 6-month mortality in low/middle-income countries have had varying results.MethodsInvestigators of 11 published randomised placebo-controlled NVAS trials (n=163 567 children) reanalysed their data according to an agreed plan and pooled the primary outcomes of mortality from supplementation through 6 and 12 months of age using random effects models and meta-regression. One investigator withdrew but allowed use of the data.FindingsOverall there was no effect of NVAS on infant survival through 6 (risk ratio (RR) 0.97; 95% CI 0.89 to 1.06) or 12 months of age (RR 1.00; 95% CI 0.93 to 1.08) but results varied by study population characteristics.NVAS significantly reduced 6-month mortality among the trials conducted in Southern Asia (RR 0.87; 95% CI 0.77 to 0.98), in contexts with moderate or severe vitamin A deficiency (defined as 10% or higher proportion of women with serum retinol <0.7 µmol/L or 5% or more women with night blindness) (RR 0.87; 95% CI 0.80 to 0.94), early infant mortality was 30 or more per 1000 live births (RR 0.91; 95% CI 0.85 to 0.98), 75% or more of infant mortality occurred in the first 6 months of life (RR 0.92; 95% CI 0.84 to 1.01), or where >32% mothers had no schooling (RR 0.88; 95% CI 0.80 to 0.96). NVAS did not reduce mortality in the first 6 months of life in trials conducted in Africa, in contexts characterised by a low prevalence of vitamin A deficiency, lower rates of infant mortality and where maternal education was more prevalent. There was a suggestion of increased infant mortality in trials conducted in Africa (RR 1.07; 95% CI 1.00 to 1.15).Individual-level characteristics such as sex, birth weight, gestational age and size, age at dosing, parity, time of breast feeding initiation, maternal education and maternal vitamin A supplementation did not modify the impact of NVAS.ConclusionNVAS reduced infant mortality in South Asia, in contexts where the prevalence of maternal vitamin A deficiency is moderate to severe and early infant mortality is high; but it had no beneficial effect on infant survival in Africa, in contexts where the prevalence of maternal vitamin A deficiency is lower, early infant mortality is low.


2017 ◽  
Vol 13 (10) ◽  
pp. S200-S201
Author(s):  
Anahita Jalilvand ◽  
Andrew Suzo ◽  
Kejal Shah ◽  
Bradley Needleman ◽  
Sabrena Noria

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10502
Author(s):  
Huan Guo ◽  
Xinke Zhao ◽  
Haixiang Su ◽  
Chengxu Ma ◽  
Kai Liu ◽  
...  

Background Radiation exposure of the thorax is associated with a greatly increased risk of cardiac morbidity and mortality even after several decades of advancement in the field. Although many studies have demonstrated the damaging influence of ionizing radiation on cardiac fibroblast (CF) structure and function, myocardial fibrosis, the molecular mechanism behind this damage is not well understood. miR-21, a small microRNA, promotes the activation of CFs, leading to cardiac fibrosis. miR-21 is overexpressed after irradiation; however, the relationship between increased miR-21 and myocardial fibrosis after irradiation is unclear. This study was conducted to investigate gene expression after radiation-induced CF damage and the role of miR-21 in this process in rats. Methods We sequenced irradiated rat CFs and performed weighted correlation network analysis (WGCNA) combined with differentially expressed gene (DEG) analysis to observe the effect on the expression profile of CF genes after radiation. Results DEG analysis showed that the degree of gene changes increased with the radiation dose. WGCNA revealed three module eigengenes (MEs) associated with 8.5-Gy-radiation—the Yellow, Brown, Blue modules. The three module eigengenes were related to apoptosis, G2/M phase, and cell death and S phase, respectively. By blocking with the cardiac fibrosis miRNA miR-21, we found that miR-21 was associated with G2/M blockade in the cell cycle and was mainly involved in regulating extracellular matrix-related genes, including Grem1, Clu, Gdf15, Ccl7, and Cxcl1. Stem-loop quantitative real-time PCR was performed to verify the expression of these genes. Five genes showed higher expression after 8.5 Gy-radiation in CFs. The target genes of miR-21 predicted online were Gdf15 and Rsad2, which showed much higher expression after treatment with antagomir-miR-21 in 8.5-Gy-irradiated CFs. Thus, miR-21 may play the role of fibrosis and G2/M blockade in regulating Grem1, Clu, Gdf15, Ccl7, Cxcl1, and Rsad2 post-irradiation.


Animals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 38 ◽  
Author(s):  
Majid Shakeri ◽  
Jeremy James Cottrell ◽  
Stuart Wilkinson ◽  
Weicheng Zhao ◽  
Hieu Huu Le ◽  
...  

In a 2 × 2 factorial design, 60 male Ross-308 broilers were fed either a control or 1 g/kg betaine diet and housed under thermoneutral (TN) or heat stress (HS) conditions. Broilers were acclimated to diets for 1 week under TN (25 °C), then either kept at TN or HS, where the temperature increased 8 h/day at 33 °C and 16 h/day at 25 °C for up to 10 days. Respiration rate (RR) was measured at four time points, and on each of 1, 2, 3, 7 and 10 days of HS, 12 broilers were injected with 0.5 mg/kg of Evans Blue Dye (EBD) solution to quantify regional changes in tissue damage. Betaine was quantified in tissues, and ileal damage was assessed via morphometry and transepithelial resistance (TER). Heat stress elevated RR (p < 0.001) and resulted in reduced villous height (p = 0.009) and TER (p < 0.001), while dietary betaine lowered RR during HS (p < 0.001), increased betaine distribution into tissues, and improved ileal villous height (p < 0.001) and TER (p = 0.006). Heat stress increased EBD in the muscle and kidney of chickens fed the control diet but not in those receiving betaine. Overall, these data indicate that supplemented betaine is distributed to vital organs and the gastrointestinal tract, where it is associated with improved tolerance of HS. Furthermore, EBD markers help reveal the effects of HS on organs dysfunction.


Author(s):  
Roy Hajjar ◽  
Carole S Richard ◽  
Manuela M Santos

Butyrate is a short-chain fatty acid produced by colonic gut bacteria as a result of fermentation of dietary fibers. In the colon, butyrate is a major energy substrate and contributes to the nutritional support and proliferation of a healthy mucosa. It also promotes the intestinal barrier function by enhancing mucus production and tight junctions. In addition to its pro-proliferative effect in healthy colonocytes, butyrate inhibits the proliferation of cancer cells. The antineoplastic effect of butyrate is associated with the inhibitory effect of butyrate on histone deacetylase (HDAC) enzymes, which promote carcinogenesis. Due to the metabolic shift of cancer cells toward glycolysis, unused butyrate accumulates and inhibits procarcinogenic HDACs. In addition, recent studies suggest that butyrate may improve the healing of colonic tissue after surgery in animal models, specifically at the site of reconnection of colonic ends - anastomosis - after surgical resection. Here, we review current evidence on the impact of butyrate on epithelial integrity and colorectal cancer and present current knowledge on data that support its potential applications in surgical practice.


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