The role of nucleotides in the immune and gastrointestinal systems: potential clinical applications

The Mechanism of the Selective Antiproliferation Effect of Guanine-Based Biomolecules and Its Compensation

As endogenous biomolecules, guanine, guanine-based nucleosides, and nucleotides are essential for cellular DNA/RNA synthesis, energy metabolism, and signal transduction. However, these biomolecules have been found to have a cell-specific antiproliferation effect at higher concentrations, and the mechanism is unclear. In this study, we demonstrate that guanine deaminase (GDA) is a major factor in determining the cell-type selectivity to the antiproliferation effect of guanine-based biomolecules. GDA catalyzes the deamination of guanine to xanthine, which is an essential part of the guanine degradation pathway. GDA deficient cells could not efficiently remove the excess guanine-based biomolecules. These excess molecules disturb the metabolism of adenine-, cytosine-, and thymine-based nucleotides; subsequently inhibit the DNA synthesis and cell growth; and eventually result in the apoptosis/death of GDA deficient cells. The inhibition of DNA synthesis could be relieved by simultaneous addition of adenine- and cytosine-based nucleosides, and the inhibited DNA synthesis could be restarted by post addition of them, which subsequently reduces the antiproliferation effect of guanine-based biomolecules or even totally restores the cell proliferation. These results provide important information for the development of guanine-based drugs or guanine-rich oligonucleotide drugs, as well as for the safety evaluation of food with a high level of guanine-based compounds.

Responses of broiler chickens to Eimeria challenge when fed a nucleotide-rich yeast extract

Nucleotide-rich yeast extract (YN) was investigated for effects on growth performance, jejunal physiology, and cecal microbial activity in Eimeria-challenged broiler chickens. A total of 360-day-old male chicks (Ross × Ross 708) were placed on floor pens and provided a corn-soybean meal-based diet without or with YN (500 g/MT; n = 12). On d 10, 6 replicates per diet were orally administered with 1 mL of E. acervulina and E. maxima sporulated oocysts and the rest (non-challenged control) were administered with 1 mL of distilled water. On d 15, 5 birds/pen were then necropsied for intestinal lesion scores, histomorphology and cecal digesta pH, short chain fatty acids (SCFA), and microbial community using Illumina Miseq platform. Supplemental YN improved (P = 0.01) Feed conversion ratio (FCR) during the prechallenge phase (d 0 to 10). In the postchallenge period (d 11 to 15), Eimeria depressed (P < 0.05) Body weight gain (BWG) relative to non-challenged birds, whereas YN-fed birds had a higher (P = 0.05) BWG compared to that of non-YN-fed birds. There was an interaction between YN and Eimeria on jejunal villi height (VH) (P = 0.001) and expression of cationic amino acid transporter 1(CAT1) (P = 0.04). Specifically, in the absence of Eimeria, YN-fed birds had a shorter VH (892 vs. 1,020 μm) relative to that of control but longer VH (533 vs. 447 μm) in the presence of Eimeria. With respect to CAT1, YN-fed birds had a higher (1.65 vs. 0.78) expression when subjected to Eimeria than when not challenged. Independently, Eimeria decreased (P < 0.01) the jejunal expression of maltase, Na glucose transporter 1 and occludin genes, ceca digesta abundance of genus Clostridium cluster XlVa and Oscillibacter but increased (P < 0.01) jejunal proliferating cell nuclear antigen and interleukin 10. Interaction between YN and Eimeria was observed for ceca digesta pH (P = 0.04) and total SCFA (P = 0.01) such that YN increased SCFA in the absence of Eimeria but reduced SCFA and increased pH in the presence of Eimeria. In summary, Eimeria impaired performance and gut function and shifted gut microbiome; YN improved performance independently, attenuated Eimeria damage on indices of gut function, and modulated cecal microbiome.

Immunonutrition in Critical Illness: What Is the Role?

Acute illness-associated malnutrition leads to muscle wasting, delayed wound healing, failure to wean from ventilator support, and possibly higher rates of infection and longer hospital stays unless appropriate metabolic support is provided in the form of nutrition therapy. Agreement is still lacking about the value of individual immune-modulating substrates for specific patient populations. However, it has long been agreed that there are 3 primary targets for these substrates: 1) mucosal barrier function, 2) cellular defense function, and 3) local and systemic inflammation. These targets guide the multitude of interventions necessary to stabilize and treat the hypercatabolic intensive care unit patient, including specialized nutrition therapy. The paradigm shift that occurred 30 years ago created a unique role for nutrition as an agent to support host defense mechanisms and prevent infectious complications in the critically ill patient. This overview of immunonutrition will discuss the evidence for its role in critical illness today.

Influence of dietary inosine and vitamin C supplementation on growth, blood chemistry, oxidative stress, innate and adaptive immune responses of red sea bream, Pagrus major juvenile

Both inosine (INO) and vitamin C (l-ascorbic acid, AsA) play important roles in growth performance, feed utilization and health status of fish. Therefore, a 56 days feeding trial was conducted to determine the interactive effects of dietary INO and AsA on growth performance, oxidative status, innate and adaptive immune responses of red sea bream. Fish growth performance and fed utilization parameters were significantly affected by dietary INO supplementation but not by AsA. Fish fed diets with INO at 4 g kg^-1 diet in combination of high and low levels of AsA (3.1 g kg-1 and 9.3 g kg-1) produced the highest growth and feed utilization performances. In terms of growth and feed utilization performances no significant interaction effects were observed between INO and AsA. Dietary INO significantly influenced hematocrit, glucose and glutamyl oxaloacetic transaminase (GOT) content of red sea bream meanwhile AsA also significantly influenced hematocrit, glucose, total cholesterol, blood urea nitrogen (BUN) and glutamic-pyruvate transaminase (GPT) content of the test fish. No significant interaction effects was also observed between INO and AsA on measured hematological parameters. Reactive oxygen metabolites (d-ROMs) significantly influenced by both INO and AsA. Fish fed diet groups D1, D4 and D6 showed best oxidative stress resistance. Only INO was a significant factor on nitro-blue-tetrazolium activity (NBT) and bactericidal activity (BA). Neither INO nor AsA was a significant factor on serum catalase activity (CAT), total serum protein (TSP), peroxidase activity (PA) and lysozyme activity (LA). No significant interaction effects was observed between INO and AsA on measured innate immune parameters. Agglutination antibody titer was significantly influenced by dietary supplementation, after 15 days of vaccination but not in 21 days. In the day 15th fish and diet group D3 and D5 showed significantly higher values compared to diet groups control and D1. INO was the only significant factor of increasing agglutination antibody titer in 15 t h day. While AsA was not a significant factor on agglutination antibody titer values in day 15 t h, there was an interaction between dietary INO and AsA levels. Finally under the experimental conditions, fish fed high INO and low AsA levels (4 g kg^-1 and 0.31 g kg^-1 diet, respectively) showed best growth and feed utilization performance. Simultaneously, low level of INO and high level of AsA (2 g kg^-1 and 0.93 g kg^-1 diet, respectively) improved blood chemistry and immunological parameters. Furthermore, combined use of INO and AsA is possible to improve hemato-immunological responses of red sea bream.

Intestinal Nucleoside Transporters: Function, Expression, and Regulation

The gastrointestinal tract is the absorptive organ for nutrients found in foods after digestion. Nucleosides and, to a lesser extent nucleobases, are the late products of nucleoprotein digestion. These metabolites are absorbed by nucleoside (and nucleobase) transporter (NT) proteins. NTs are differentially distributed along the gastrointestinal tract showing also polarized expression in epithelial cells. Concentrative nucleoside transporters (CNTs) are mainly located at the apical side of enterocytes, whereas equilibrative nucleoside transporters (ENTs) facilitate the basolateral efflux of nucleosides and nucleobases to the bloodstream. Moreover, selected nucleotides and the bioactive nucleoside adenosine act directly on intestinal cells modulating purinergic signaling. NT-polarized insertion is tightly regulated. However, not much is known about the modulation of intestinal NT function in humans, probably due to the lack of appropriate cell models retaining CNT functional expression. Thus, the possibility of nutritional regulation of intestinal NTs has been addressed using animal models. Besides the nutrition-related role of NT proteins, orally administered drugs also need to cross the intestinal barrier, this event being a major determinant of drug bioavailability. In this regard, NT proteins might also play a role in pharmacology, thereby allowing the absorption of nucleoside- and nucleobase-derived drugs. The relative broad selectivity of these membrane transporters also suggests clinically relevant drug-drug interactions when using combined therapies. This review focuses on all these physiological and pharmacological aspects of NT protein biology. © 2017 American Physiological Society. Compr Physiol 8:1003-1017, 2018.

Simultaneous quantification of free amino acids and 5'-nucleotides in shiitake mushrooms by stable isotope labeling-LC-MS/MS analysis

Evaluation of free amino acids (FAAs) and nucleotides in various food matrices has been a widely studied topic in recent years. Here, a fast and efficient strategy for the simultaneous analysis of 20 FAAs and six 5'-nucleotides, using stable isotope labeling-liquid chromatography coupled with tandem mass spectrometry (SIL-LC-MS/MS) is proposed. The method was validated with respect to selectivity, linearity, limits of detection (LOD) and quantification (LOQ), recovery, precision, and stability. LOQs of most FFAs were lower than 1 ng/mL, and 5'-nucleotides were in the range of 5-20 ng/mL. FAAs and 5'-nucleotides in ten shiitake mushrooms from different cultivate areas were further analyzed. Results showed that the contents of cytidine 5'-monophosphate, adenosine 5'-monophosphate, lysine, threonine, arginine were significantly different. Principal component analysis showed clear discrimination of origins, seasons and species. Thus, the proposed method is suitable for the fast discrimination of species and geographical origins of shiitake mushrooms.

Prevention of disease progression in Leishmania infantum-infected dogs with dietary nucleotides and active hexose correlated compound

Background

The prevalence of Leishmania infantum infection in clinically healthy dogs can be several times higher than that of clinical disease in endemic areas. Although treatment is not recommended in dogs with subclinical infection, these animals should be managed to prevent disease progression and parasite transmission to human beings or to other dogs. Dietary nucleotides and active hexose correlated compound (AHCC) have been shown to modulate the immune response. A recent study in dogs with clinical leishmaniosis receiving an initial 28-day course of methylglucamine antimoniate showed that six-month administration of a dietary supplement containing nucleotides plus AHCC achieves similar efficacy to allopurinol. Since the type of immune response plays a key role in the evolution of patients with leishmaniosis, the present study was aimed at evaluating the preventive effect of this supplement in avoiding or delaying disease progression in clinically healthy Leishmania-infected dogs.

Methods

Forty-six dogs were included in this multicenter, randomized, double-blind, placebo-controlled trial. Dogs received once-daily oral administration of a placebo or a dietary supplement containing nucleotides plus AHCC. Disease progression was monitored throughout the study in both groups. At 0, 60, 180 and 365 days of treatment, clinical signs were evaluated using a validated clinical scoring system, and several analytes were measured from blood, urine, and bone marrow samples.

Results

During the study, a significantly lower (P = 0.047) proportion of dogs changed their clinical status and became sick in the supplement group (3/20; 15%), compared to the placebo group (10/22; 45.5%). ELISA-determined antibody titers were significantly reduced compared to baseline at all time points with the supplement (P < 0.01), but not with the placebo. The mean clinical score of disease severity was significantly lower in the supplement group after 180 days (P = 0.014). No significant differences were observed for the other parameters. The dietary supplement was well tolerated.

Conclusions

Oral administration of nucleotides plus AHCC for 365 days in clinically healthy L. infantum-infected dogs is safe, allows a significant reduction in anti-Leishmania antibodies, and leads to a lower disease progression rate, hence exerting a preventive effect.

New, Immunomodulatory, Oral Nutrition Formula for Use Prior to Surgery in Patients With Head and Neck Cancer: An Exploratory Study

BACKGROUND

The perioperative use of immunomodulatory nutrition formulas in patients with head and neck cancer reduces the number of postoperative infections and the length of hospital stay.

OBJECTIVE

An exploratory, randomized, controlled, blind, clinical trial was designed to examine the effect of the preoperative consumption of a new, immunomodulatory, oral nutrition formula in patients with head and neck cancer.

METHODS

Thirty-eight patients were randomized to receive either 400 mL/d of either the new immunomodulatory formula (IF) or that commonly used in clinical practice (CF) over 10 days prior to surgery. Thirty-three patients completed the study. Compliance, tolerance, the length of hospital stay, the incidence of infections and noninfectious complications before discharge, and the same up to 15 and 30 days after discharge were recorded.

RESULTS

The percentage of patients who developed infections before discharge was significantly lower in the IF than in the CF group (P = .013), as was the number of infections/100 patients/d (P = .035). The length of hospital stay was significantly shorter in the IF group (P = .001). Both formulas were safe and well tolerated. No other differences were detected. These results suggest preoperative consumption of the new formula to be beneficial for patients with neck and head cancer. Further trials are needed to confirm these results and to test the efficacy of the formula in patients with other conditions.

CONCLUSION

The new formula can be safely prescribed as part of the preoperative treatment of patients with head and neck cancer and might reduce the problem of postoperative infection.

Enteral immunonutrition versus enteral nutrition for gastric cancer patients undergoing a total gastrectomy: a systematic review and meta-analysis

Background

Nutrition support is a common means for patients with gastric cancer, especially for those undergoing elective surgery. Recently, enteral immunonutrition (EIN) was increasingly found to be more effective than enteral nutrition (EN) in enhancing the host immunity and eventually improving the prognosis of gastric cancer patients undergoing gastrectomy. However, the results reported were not consistent. This meta-analysis aimed to assess the impact of EIN for patients with GC on biochemical, immune indices and clinical outcomes.

Methods

Four electronical databases (Medline, EMBASE, Scopus and Cochrane library) were used to search articles in peer-reviewed, English-language journals. Mean difference (MD), Relative risk (RR), or standard mean difference (SMD) with 95% confidence interval (CI) were calculated. Heterogeneity was assessed by Cochrane Q and I² statistic combined with corresponding P-value. The analysis was carried out with RevMan 5.3.

Results

Seven studies involving 583 patients were eligible for the pooled analysis. EIN, when beyond a 7-day time-frame post-operatively (D ≥ 7), increased level of CD4⁺ (SMD = 0.99; 95% CI, 0.65–1.33; P < 0.00001), CD4⁺/ CD8⁺ (SMD = 0.34; 95% CI, 0.02–0.67; P = 0.04), the IgM (SMD = 1.15; 95% CI, 0.11–2.20; P = 0.03), the IgG (SMD = 0.98; 95% CI, 0.55–1.42; P < 0.0001), the lymphocyte (SMD = 0.69; 95% CI, 0.32–1.06; P = 0.0003), and the proalbumin (SMD = 0.73; 95% CI, 0.33–1.14; P = 0.0004). However, those increased effects were not obvious within a 7-day time-frame post-operatively (D < 7). The levels of CD8⁺ and other serum proteins except proalbumin were not improved both on D ≥ 7 and D < 7. Clinical outcomes such as systemic inflammatory response syndrone (SIRS) (MD, - 0.89 days; 95% CI, - 1.40 to - 0.39; P = 0.005), and postoperative complications (RR, 0.29; 95% CI, 0.14–0.60; P = 0.001) were significantly reduced in EIN group. Pulmonary infection and length of hospitalization (LHS) were not improved no matter what time after surgery.

Conclusions

EIN was found to improve the cellular immunity, modulate inflammatory reaction and reduce postoperative complication for GC patients undergoing radical gastrointestinal surgery. Exclusion of grey literature and non-English language studies was the key limitation in this study.

Effect of yeast-derived products and distillers dried grains with solubles (DDGS) on growth performance and local innate immune response of broiler chickens challenged with Clostridium perfringens

This study evaluated the effect of yeast-derived products on growth performance, gut lesion score, intestinal population of Clostridium perfringens, and local innate immunity of broiler chickens challenged with C. perfringens. One-day-old broiler chickens were randomly assigned to eight dietary treatments providing six replicate pens of 55 birds each per treatment. Dietary treatments consisted of Control diets without and with C. perfringens challenge, and diets containing bacitracin methylene disalicylate (BMD, 55 g/tonne), nucleotides (150 g/tonne), yeast cell wall (YCW, 300 g/tonne), and a commercial product Maxi-Gen Plus (1 kg/tonne) fed to chickens challenged with C. perfringens. Diets containing 10% distillers dried grains with solubles without and with C. perfringens challenge were also used. Birds were orally challenged with C. perfringens (10(8) colony-forming units (cfu)/bird) on day 14. On day 21, intestinal samples were collected for gene expression analysis. Pathogen challenge significantly (P < 0.05) impaired feed intake, body weight gain, and feed conversion ratio (FCR) shortly after the challenge (14-21 days). Increased C. perfringens counts and intestinal lesion scores were observed for challenged birds except the BMD-containing diet. Over the entire trial (1-35 days), no difference in growth performance was observed except the BMD diet which improved FCR over the Control, challenged group. Birds receiving nucleotides showed increased expression of toll-like receptors and cytokines interleukin (IL)-4 and IL-18 compared to the Control, challenged group. Expression of macrophage mannose receptor and IL-18 was upregulated in birds receiving YCW. Increased expression of cytokines and receptors involved in innate immunity in broilers receiving nucleotides and YCW suggests the immunomodulatory properties of these products under pathogen challenge conditions.

The benefit of immunonutrition in patients undergoing hepatectomy: a systematic review and meta-analysis

Perioperative immunonutrition in liver resection remains doubtful. A systematic review and meta-analysis was conducted to compare postoperative outcomes between patients undergoing hepatectomy who received perioperative immunonutrition and those who did not.A PubMed, Embase, Cochrane Central Register of Controlled Trials, and Web of Knowledge database search was performed to retrieve all of the randomized controlled trials (RCTs) evaluating the value of perioperative immunonutrition in patients undergoing hepatectomy until the end of September 2016. Data extraction and quality assessment of RCTs were performed in accordance with PRISMA guidelines. The quality of evidence for each postoperative outcome was assessed using the GRADEpro analysis. A random-effects model was used to conduct a meta-analysis with RevMan 5.3.5 software. Eight RCTs including 805 patients (402 with and 403 without immunonutrition) were identified. Immunonutrition, mainly ω-3 fatty acids, significantly reduced the incidence of postoperative total complications (risk ratio [RR] = 0.59; 95% confidence interval [CI], 0.46-0.75; p < 0.0001) and infectious complications (RR = 0.46; 95% CI, 0.32-0.68; p < 0.0001), and shortened the length of hospital stay (standardized mean difference, -0.49; 95% CI, -0.81 to -0.16; p = 0.0004). There was no significant between-group difference in postoperative mortality (RR = 0.46; 95% CI, 0.16-1.31; p = 0.15). Immunonutrition, mainly ω-3 fatty acids, is potentially beneficial in reducing overall and infectious postoperative complications and in shortening the hospital stay for patients undergoing hepatectomy.

"It's a gut feeling" - Escherichia coli biofilm formation in the gastrointestinal tract environment

Escherichia coli can commonly be found, either as a commensal, probiotic or a pathogen, in the human gastrointestinal (GI) tract. Biofilm formation and its regulation is surprisingly variable, although distinct regulatory pattern of red, dry and rough (rdar) biofilm formation arise in certain pathovars and even clones. In the GI tract, environmental conditions, signals from the host and from commensal bacteria contribute to shape E. coli biofilm formation within the multi-faceted multicellular communities in a complex and integrated fashion. Although some major regulatory networks, adhesion factors and extracellular matrix components constituting E. coli biofilms have been recognized, these processes have mainly been characterized in vitro and in the context of interaction of E. coli strains with intestinal epithelial cells. However, direct observation of E. coli cells in situ, and the vast number of genes encoding surface appendages on the core or accessory genome of E. coli suggests the complexity of the biofilm process to be far from being fully understood. In this review, we summarize biofilm formation mechanisms of commensal, probiotic and pathogenic E. coli in the context of the gastrointestinal tract.

Metabolomic profiling of brain from infants who died from Sudden Infant Death Syndrome reveals novel predictive biomarkers

OBJECTIVE

Sudden Infant Death Syndrome (SIDS) is defined as the sudden death of an infant <1 year of age that cannot be explained following a thorough investigation. Currently, no reliable clinical biomarkers are available for the prediction of infants who will die of SIDS.

STUDY DESIGN

This study aimed to profile the medulla oblongata from postmortem human brain from SIDS victims (n=16) and compare their profiles with that of age-matched controls (n=7).

RESULTS

Using LC-Orbitrap-MS, we detected 12 710 features in electrospray ionization positive (ESI+) mode and 8243 in ESI- mode from polar extracts of brain. Five features acquired in ESI+ mode produced a predictive model for SIDS with an area under the receiver operating characteristic curve (AUC) of 1 (confidence interval (CI): 0.995-1) and a predictive power of 97.4%. Three biomarkers acquired in ESI- mode produced a predictive model with an AUC of 0.866 (CI: 0.767-0.942) and a predictive power of 77.6%. We confidently identified 5 of these features (l-(+)-ergothioneine, nicotinic acid, succinic acid, adenosine monophosphate and azelaic acid) and putatively identify another 4 out of the 15 in total.

CONCLUSIONS

This study underscores the potential value of metabolomics for studying SIDS. Further characterization of the metabolome of postmortem SIDS brains could lead to the identification of potential antemortem biomarkers for novel prevention strategies for SIDS.

What's in the Bottle? A Review of Infant Formulas

Infant formulas are designed to be a substitute for breast milk. Since they are sole source of nutrition for growing and developing infants, they are highly regulated by the government. All ingredients in infant formulas must be considered "generally recognized as safe." Manufacturers are continually modifying their products to make them more like breast milk. Functional ingredients added to infant formula include long-chain polyunsaturated fatty acids, nucleotides, prebiotics, and probiotics. The most common breast milk substitutes are standard cow's milk-based term infant formulas, which include subcategories of organic and breast milk supplementation, and come in standard dilutions of 19 or 20 calories per ounce. In addition to standard cow's milk-based term infant formulas, there is a line of term infant formulas marketed for signs and symptoms of intolerance. These products include modifications in lactose content, partially hydrolyzed protein, added probiotics, or added rice starch. There are also specialized formulas for medical conditions such as prematurity, gastrointestinal disorders, allergy, disorders of fat metabolism, and renal insufficiency. Infants on specialty formulas should be monitored closely by medical professionals. Formulas come in ready-to-feed, liquid concentrate, and powder forms. Each offers advantages and disadvantages. Each step in the formula mixing process or each manipulation required for the feeding is another opportunity to introduce bacteria to the formula. There are guidelines for preparing formula in institutions. Standard dilution and mixing instructions are different for each formula, so individual recipes are needed. Caregivers should also be educated on proper hygiene when preparing formula at home.

Physiological Effects of Nucleotide Supplementation on Resistance Exercise Stress in Men and Women

Nucleotide supplementation can reduce postexercise immunosuppression and hypothalamic-pituitary axis (HPA) axis activation in endurance exercise models. Nucleotide supplementation may aid recovery from other exercise modalities, such as heavy resistance exercise. Thus, the purpose of this investigation was to investigate the effects of nucleotide supplementation on the acute cortisol and immune responses to heavy resistance exercise and its effects on recovery. A double-blinded, crossover, mixed methods design with 10 men and 10 women was used. Each performed an acute heavy resistance exercise protocol (AHREP) after a loading period with a nucleotide or placebo supplement. Before and after the AHREP, and at 24, 48, and 72 hours post, blood samples were analyzed for cortisol, myeloperoxidase (MPO), and absolute neutrophil, lymphocyte, and monocyte counts. Creatine kinase (CK) was analyzed before and 24, 48, and 72 hours after the AHREP. Performance measures, including peak back squat isometric force and peak countermovement jump power were also analyzed. Nucleotide supplementation resulted in significant (p ≤ 0.05) decreases in cortisol and MPO immediately after the AHREP, and significantly lower CK values 24 hours later. The AHREP significantly affected leukocyte counts; however, no treatment effects were observed. Greater isometric force was observed immediately after AHREP and at 24 hours and 48 hours with nucleotide supplementation. Nucleotide supplementation seems to attenuate muscle damage, HPA axis and immune system activation, and performance decrements after heavy resistance exercise.

Can specific nutrients stimulate bowel wound healing?

PURPOSE OF REVIEW

The purpose of review is to provide an overview on specific nutrients which play an important role in bowel wound healing, and to judge the efficacy of supplementation to derive recommendations for clinical practice.

RECENT FINDINGS

Glutamine, arginine, butyrate, ω-3 fatty acids, nucleotides, and several micronutrients are involved in bowel wound healing. However, with regard to clinical trials, the efficacy of supplementation of specific nutrients on bowel wound healing in patients with inflammatory bowel diseases has not been clarified yet. In patients undergoing colon surgery, sufficient evidence exists that the perioperative supply of an enteral immunomodulating formula enriched with arginine, nucleotides, and ω-3 fatty acids may improve intestinal wound healing, considering the lower risk of wound infections, wound dehiscence, and intra-abdominal abscess.

SUMMARY

Even if a range of nutrients are involved in bowel wound healing, only perioperative supply of an enteral immunomodulating formula to cancer patients undergoing colon surgery, can be recommended. Further randomized controlled trials are needed to elucidate the efficacy of individual nutrients on intestinal wound healing.

Dietary effects of adenosine monophosphate to enhance growth, digestibility, innate immune responses and stress resistance of juvenile red sea bream, Pagrus major

Our study explored the dietary effects of adenosine monophosphate (AMP) to enhance growth, digestibility, innate immune responses and stress resistance of juvenile red sea bream. A semi-purified basal diet supplemented with 0% (Control), 0.1% (AMP-0.1), 0.2% (AMP-0.2), 0.4% (AMP-0.4) and 0.8% (AMP-0.8) purified AMP to formulate five experimental diets. Each diet was randomly allocated to triplicate groups of fish (mean initial weight 3.4 g) for 56 days. The results indicated that dietary AMP supplements tended to improve growth performances. One of the best ones was found in diet group AMP-0.2, followed by diet groups AMP-0.1, AMP-0.4 and AMP-0.8. The Apparent digestibility coefficients (dry matter, protein and lipid) also improved by AMP supplementation and the significantly highest dry matter digestibility was observed in diet group AMP-0.2. Fish fed diet groups AMP-0.2 and AMP-0.4 had significantly higher peroxidase and bactericidal activities than fish fed the control diet. Nitro-blue-tetrazolium (NBT) activity was found to be significantly (P < 0.05) greater in fish fed diet groups AMP-0.4 and AMP-0.8. Total serum protein, lysozyme activity and agglutination antibody titer were also increased (P > 0.05) by dietary supplementation. In contrast, catalase activity decreased with AMP supplementation. Moreover, the fish fed AMP supplemented diets had better improvement (P < 0.05) in body lipid contents, condition factor, hematocrit content and glutamyl oxaloacetic transaminase (GOT) level than the control group. Supplementation also improved both freshwater and oxidative stress resistances. Interestingly, the fish fed diet groups AMP-0.2 and AMP-0.4 showed the least oxidative stress condition. Finally it is concluded that, dietary AMP supplementation enhanced the growth, digestibility, immune response and stress resistance of red sea bream. The regression analysis revealed that a dietary AMP supplementation between 0.2 and 0.4% supported weight gain and lysozyme activity as a marker of immune functions for red sea bream, which is also inline with the most of the growth and health performance parameters of fish under present experimental conditions.

Ribosomopathies: how a common root can cause a tree of pathologies

Defects in ribosome biogenesis are associated with a group of diseases called the ribosomopathies, of which Diamond-Blackfan anemia (DBA) is the most studied. Ribosomes are composed of ribosomal proteins (RPs) and ribosomal RNA (rRNA). RPs and multiple other factors are necessary for the processing of pre-rRNA, the assembly of ribosomal subunits, their export to the cytoplasm and for the final assembly of subunits into a ribosome. Haploinsufficiency of certain RPs causes DBA, whereas mutations in other factors cause various other ribosomopathies. Despite the general nature of their underlying defects, the clinical manifestations of ribosomopathies differ. In DBA, for example, red blood cell pathology is especially evident. In addition, individuals with DBA often have malformations of limbs, the face and various organs, and also have an increased risk of cancer. Common features shared among human DBA and animal models have emerged, such as small body size, eye defects, duplication or overgrowth of ectoderm-derived structures, and hematopoietic defects. Phenotypes of ribosomopathies are mediated both by p53-dependent and -independent pathways. The current challenge is to identify differences in response to ribosomal stress that lead to specific tissue defects in various ribosomopathies. Here, we review recent findings in this field, with a particular focus on animal models, and discuss how, in some cases, the different phenotypes of ribosomopathies might arise from differences in the spatiotemporal expression of the affected genes.

Summary: This paper reviews recent data on Diamond Blackfan anemia and discusses them in connection with other ribosomopathies.

Effect of yeast-derived products on systemic innate immune response of broiler chickens following a lipopolysaccharide challenge

This study evaluated the effect of yeast-derived products on growth performance, serum antibody levels, and mRNA gene expression of pattern-recognition receptors, and cytokines in broiler chickens. Two hundred and sixteen one-day-old male broiler chickens (Ross-308) were randomly assigned to six dietary treatments with six replicates (cage) of 6 birds per cage. Dietary treatments consisted of a Control diet without antibiotics (C), and diets containing 11 mg/kg of "virginiamycin", 0.25% of yeast cell wall (YCW), 0.2% of a commercial product "Maxi-Gen Plus" containing processed yeast and nucleotides, 0.05% of nucleotides, or a diet containing 8% of distiller's dried grains with solubles (DDGS). On d 21 post-hatch blood samples were collected from 6 birds per treatment and serum sample were analyzed for antibody levels. After blood sampling, birds were injected intraperitoneally with 3 mg/kg of BW of lipopolysaccharide (LPS). The unchallenged group was fed the Control diet and injected with saline solution. Spleen samples were collected to measure the gene expression of toll-like receptors (TLR)2b, TLR4, and TLR21, macrophage mannose receptor (MMR), and cytokines including interleukin (IL)-12, IL-10, IL-4, IL-6, IL-18, and interferon (IFN)-γ. No significant difference in body weight gain, feed intake, and FCR were observed among treatments. Regarding humoral immunity, the diet supplemented with YCW increased serum immunoglobulin (Ig)A level compared with the antibiotic group; however, serum concentrations of IgG and IgM were not affected by dietary treatments. Relative gene expression of TLR2 and TLR4 was not affected by dietary treatments, whereas the expression of TLR21 and MRR was upregulated in diets containing YCW and DDGS. The diet supplemented with YCW increased the expression of all cytokines, and expression of IFN-γ was upregulated in the DDGS group. However, no significant difference was observed for cytokine gene expression in the antibiotic and nucleotide diets. In conclusion, supplementation of diet with YCW stimulated the systemic innate immune responses of broiler chickens following challenge with LPS.

Should perioperative immunonutrition for elective surgery be the current standard of care?

Postoperative infectious complications are independently associated with increased hospital length of stay (LOS) and cost and contribute to significant inpatient morbidity. Many strategies such as avoidance of long periods of preoperative fasting, re-establishment of oral feeding as early as possible after surgery, metabolic control and early mobilization have been used to either prevent or reduce the incidence of postoperative infections. Despite these efforts, it remains a big challenge to our current healthcare system to mitigate the cost of postoperative morbidity. Furthermore, preoperative nutritional status has also been implicated as an independent risk factor for postoperative morbidity. Perioperative nutritional support using enteral and parenteral routes has been shown to decrease postoperative morbidity, especially in high-risk patients. Recently, the role of immunonutrition (IMN) in postoperative infectious complications has been studied extensively. These substrates have been found to positively modulate postsurgical immunosuppression and inflammatory responses. They have also been shown to be cost-effective by decreasing both tpostoperative infectious complications and hospital LOS. In this review, we discuss the postoperative positive outcomes associated with the use of perioperative IMN, their cost-effectiveness, current guidelines and future clinical implications.

Effect of yeast-derived products and distillers dried grains with solubles (DDGS) on antibody-mediated immune response and gene expression of pattern recognition receptors and cytokines in broiler chickens immunized with T-cell dependent antigens

This study evaluated the effect of yeast-derived products on innate and antibody mediated immune response in broiler chickens following immunization with sheep red blood cells (SRBC) and bovine serum albumin (BSA). One-day-old male broiler chickens (Ross-308) were randomly assigned to 6 dietary treatments of 9 replicate cages of 5 birds each per treatment. Dietary treatments consisted of a Control diet without antibiotic, and diets containing 11 mg/kg of virginiamycin, 0.25% of yeast cell wall (YCW), 0.2% of a commercial product Maxi-Gen Plus containing processed yeast and nucleotides, 0.05% of nucleotides, or a diet containing 10% of DDGS. On days 21 and 28 post-hatching, 5 birds per treatment were immunized intramuscularly with both SRBC and BSA. One week after each immunization, blood samples were collected. Serum samples were analyzed by hemagglutination test for antibody response to SRBC, and by ELISA for serum IgM and IgG response to BSA. On d 35, 5 birds per treatment were euthanized and the tissue samples from the cecal tonsils were collected to assess the gene expression of toll-like receptors TLR2b, TLR4, and TLR21, monocyte mannose receptor (MMR), and cytokines IL-10, IL-13, IL-4, IL-12p35, and IFN-γ. The results for gene expression analysis demonstrated that the diet supplemented with YCW increased the expression of TLR2b and T-helper type 2 cytokines IL-10, IL-4, and IL-13 relative to the Control; and the expression of TLR4 and IL-13 was upregulated in the nucleotide-containing diet. However, the diets containing antibiotics or Maxi-Gen Plus downregulated the expression of IFN-γ compared to the control. The primary antibody response to SRBC was not affected by diets. However, the diet containing YCW increased the secondary antibody response to SRBC compared to the antibiotic treatment. Neither primary nor secondary IgG and IgM response against BSA were affected by diets. In conclusion, supplementation of the diet with YCW stimulated Th2 cell-mediated immune response indicating the immunomodulatory activities of these products following immunization with non-inflammatory antigens.

The role of the DNA damage response in zebrafish and cellular models of Diamond Blackfan anemia

Ribosomal biogenesis involves the processing of pre-ribosomal RNA. A deficiency of some ribosomal proteins (RPs) impairs processing and causes Diamond Blackfan anemia (DBA), which is associated with anemia, congenital malformations and cancer. p53 mediates many features of DBA, but the mechanism of p53 activation remains unclear. Another hallmark of DBA is the upregulation of adenosine deaminase (ADA), indicating changes in nucleotide metabolism. In RP-deficient zebrafish, we found activation of both nucleotide catabolism and biosynthesis, which is consistent with the need to break and replace the faulty ribosomal RNA. We also found upregulation of deoxynucleotide triphosphate (dNTP) synthesis - a typical response to replication stress and DNA damage. Both RP-deficient zebrafish and human hematopoietic cells showed activation of the ATR/ATM-CHK1/CHK2/p53 pathway. Other features of RP deficiency included an imbalanced dNTP pool, ATP depletion and AMPK activation. Replication stress and DNA damage in cultured cells in non-DBA models can be decreased by exogenous nucleosides. Therefore, we treated RP-deficient zebrafish embryos with exogenous nucleosides and observed decreased activation of p53 and AMPK, reduced apoptosis, and rescue of hematopoiesis. Our data suggest that the DNA damage response contributes to p53 activation in cellular and zebrafish models of DBA. Furthermore, the rescue of RP-deficient zebrafish with exogenous nucleosides suggests that nucleoside supplements could be beneficial in the treatment of DBA.

Long-term differential changes in mouse intestinal metabolomics after γ and heavy ion radiation exposure

Tissue consequences of radiation exposure are dependent on radiation quality and high linear energy transfer (high-LET) radiation, such as heavy ions in space is known to deposit higher energy in tissues and cause greater damage than low-LET γ radiation. While radiation exposure has been linked to intestinal pathologies, there are very few studies on long-term effects of radiation, fewer involved a therapeutically relevant γ radiation dose, and none explored persistent tissue metabolomic alterations after heavy ion space radiation exposure. Using a metabolomics approach, we report long-term metabolomic markers of radiation injury and perturbation of signaling pathways linked to metabolic alterations in mice after heavy ion or γ radiation exposure. Intestinal tissues (C57BL/6J, female, 6 to 8 wks) were analyzed using ultra performance liquid chromatography coupled with electrospray quadrupole time-of-flight mass spectrometry (UPLC-QToF-MS) two months after 2 Gy γ radiation and results were compared to an equitoxic ⁵⁶Fe (1.6 Gy) radiation dose. The biological relevance of the metabolites was determined using Ingenuity Pathway Analysis, immunoblots, and immunohistochemistry. Metabolic profile analysis showed radiation-type-dependent spatial separation of the groups. Decreased adenine and guanosine and increased inosine and uridine suggested perturbed nucleotide metabolism. While both the radiation types affected amino acid metabolism, the ⁵⁶Fe radiation preferentially altered dipeptide metabolism. Furthermore, ⁵⁶Fe radiation caused upregulation of ‘prostanoid biosynthesis’ and ‘eicosanoid signaling’, which are interlinked events related to cellular inflammation and have implications for nutrient absorption and inflammatory bowel disease during space missions and after radiotherapy. In conclusion, our data showed for the first time that metabolomics can not only be used to distinguish between heavy ion and γ radiation exposures, but also as a radiation-risk assessment tool for intestinal pathologies through identification of biomarkers persisting long after exposure.

Sublingual nucleotides prolong run time to exhaustion in young physically active men

Although dietary nucleotides have been determined to be required for normal immune function, there is limited direct interventional evidence confirming performance-enhancing effects of sublingual nucleotides in humans. A double-blind, placebo-controlled, randomized trial was conducted to evaluate the effect of sublingual nucleotides (50 mg/day) administered for 14 days in thirty young healthy physically active males, on endurance performance and immune responses. Fasting white blood cell count, natural killer cells (NKC) number, NKC cytotoxic activity, and serum immunoglobulin (IgA, IgM, IgG), and time to exhaustion, peak rate of perceived exertion, peak heart rate, and peak running speed during the exercise test were measured at baseline (day 0) and post-intervention (day 14). Time to exhaustion, as well as serum immunoglobulin A and NKC cytotoxic activity, were significantly higher at day 14 (p < 0.05) in participants supplemented with nucleotides compared with those who consumed placebo. No significant differences in other parameters were observed between groups at post-intervention. No volunteers withdrew before the end of the study nor reported any vexatious side effects of supplementation. The results of the present study suggest that sublingual nucleotides may provide pertinent benefit as both an ergogenic and immunostimulatory additive in active males.

Novel aspects of health promoting compounds in meat

Meat is an integral part of the human diet. Besides essential amino acids and nutritive factors of high quality and availability, meat provides often overlooked components of importance for human health. These are amino acids and bioactive compounds that may be very important in i) preventing muscle wasting diseases, such as in sarcopenia, ii) reducing food and caloric intake to prevent metabolic syndrome, iii) blood pressure homeostasis via ACE-inhibitory components from connective tissue, and iv) maintaining functional gut environment through meat-derived nucleotides and nucleosides. In addition, meat could be an important source of phytanic acid, conjugated linoleic acids and antioxidants. Further, it becomes increasingly apparent that design of in vitro meat will be possible, and that this development may lead to improved health benefits from commercially viable and sustainable meat products.

Analysis of nucleosides and nucleotides in infant formula by liquid chromatography-tandem mass spectrometry

A method for the simultaneous analysis of nucleosides and nucleotides in infant formula using reversed-phase liquid chromatography-tandem mass spectrometry is described. This approach is advantageous for compliance testing of infant formula over other LC-MS methods in which only nucleotides or nucleosides are measured. Following sample dissolution, protein was removed by centrifugal ultrafiltration. Chromatographic analyses were performed using a C18 stationary phase and gradient elution of an ammonium acetate/bicarbonate buffer, mass spectrometric detection and quantitation by a stable isotope-labelled internal standard technique. A single laboratory validation was performed, with spike recoveries of 80.1-112.9% and repeatability relative standard deviations of 1.9-7.2%. Accuracy as bias was demonstrated against reference values for NIST1849a certified reference material. The method has been validated for the analysis of bovine milk-based, soy-based, caprine milk-based and hydrolysed milk protein-based infant formulae.

Tolerance to a new free amino acid-based formula in children with IgE or non-IgE-mediated cow's milk allergy: a randomized controlled clinical trial

Background

Amino acid-based formulas (Aaf) are increasingly used in children with cow’s milk allergy (CMA). To be labeled hypoallergenic these formulas must demonstrate in clinical studies that they don’t provoke reactions in 90% of subjects with confirmed CMA with 95% confidence when given in prospective randomized, double-blind, placebo-controlled challenge (DBPCFC) trials. The majority of available safety data on Aaf derived from patients with IgE-mediated CMA. Considering substantial differences in the immunologic mechanism and clinical presentation of non-IgE-mediated CMA it’s important to investigate the hypoallergenicity of these formulas also in these patients. We prospectively assessed the tolerance to a new commercially available Aaf in children affected by IgE- or non-IgE-mediated CMA.

Methods

Consecutive patients affected by IgE- or non-IgE-mediated CMA, aged ≤ 4 years, were enrolled. DBPCFC was carried out with increasing doses of the new Aaf (Sineall, Humana, Milan, Italy), using validated Aaf as placebo. Faecal concentrations of calprotectin (FC) and eosinophilic cationic protein (ECP) were monitored.

Results

Sixty patients (44 male, 73.3%, median age 37, 95%CI 34.5–39.6 months, IgE-mediated CMA 29, 48.3%) were enrolled. At the diagnosis clinical symptoms were gastrointestinal (46.6%), cutaneous (36.6%), respiratory (23.3%), and systemic (10.0%). After DBPCFC with the new Aaf, no patient presented early or delayed clinical reactions. Faecal concentration of calprotectin and of ECP remained stable after the exposure to the new Aaf.

Conclusions

The new Aaf is well tolerated in children with IgE- or non-IgE-mediated CMA, and it could be used as a safe dietotherapy regimen for children with this condition.

Trial registration

The trial was registered in the ClinicalTrials.gov Protocol Registration System (ID number: NCT01622426).