Intestinal growth and morphology is associated with the increase in heat shock protein 70 expression in weaning piglets through supplementation with glutamine

Glutamine alleviated heat stress-induced damage of porcine intestinal epithelium associated with the mitochondrial apoptosis pathway mediated by heat shock protein 70

The present study aimed to investigate the effect of glutamine (Gln) addition on the damage of porcine intestinal epithelial cells (IPEC-J2) induced by heat stress (HS). IPEC-J2 cultured in logarithmic growth period in vitro were firstly exposed to 42 °C for 0.5, 1, 2, 4, 6, 8, 10, 12, and 24 h for cell viability and cultured with 1, 2, 4, 6, 8, or 10 mmol Gln per L of culture media for heat shock protein 70 (HSP70) expression to determine the optimal disposal strategy (HS, 42 °C for 12 h and HSP70 expression, 6 mmol/L Gln treatment for 24 h). Then IPEC-J2 cells were divided into three groups: control group (Con, cultured at 37 °C), HS group (HS, cultured at 42 °C for 12 h), and glutamine group (Gln+HS, cultured at 42 °C for 12 h combined with 6 mmol/L Gln treatment for 24 h). The results showed that HS treatment for 12 h significantly decreased the cell viability of IPEC-J2 (P < 0.05) and 6 mmol/L Gln treatment for 12 h increased HSP70 expression (P < 0.05). HS treatment increased the permeability of IPEC-J2, evidenced by the increased fluorescent yellow flux rates (P < 0.05) and the decreased transepithelial electrical resistance (P < 0.05). Moreover, the downregulated protein expression of occludin, claudin-1, and zonula occludens-1 was observed in HS group (P < 0.05), but Gln addition alleviated the negative effects on permeability and the integrity of intestinal mucosal barrier induced by HS (P < 0.05). In addition, HS resulted in the elevations in HSP70 expression, cell apoptosis, cytoplasmic cytochrome c potential expression, and the protein expressions of apoptosis-related factors (apoptotic protease-activating factor-1, cysteinyl aspartate-specific proteinase-3, and cysteinyl aspartate-specific proteinase-9) (P < 0.05); however, the reductions in mitochondrial membrane potential expression and B-cell lymphoma-2 expression were induced by HS (P < 0.05). But Gln treatment attenuated HS-induced adverse effects mentioned above (P < 0.05). Taken together, Gln treatment exhibited protective effects in protecting IPEC-J2 from cell apoptosis and the damaged integrity of epithelial mucosal barrier induced by HS, which may be associated with the mitochondrial apoptosis pathway mediated by HSP70.

Effects of short-distance transportation on physiological indexes, intestinal morphology, microbial community, and the transcriptome of the jejunum in weaned piglets

Transportation of livestock is unavoidable in animal production. A total of 72 piglets were randomly divided into the CON group and the TSG group, and the piglets in CON group were transported for two hours. The purpose of this study was to determine the effects of short-distance road transportation lasting 2 h on the jejunum of weaned piglets. Our results showed that compared with the control group, there was no impact on the growth performance of piglets in the transport group (P > 0.05). The concentrations of cortisol, heat shock protein (HSP)70, HSP90, C-reactive protein, interleukin (IL)-6, IL-8, IL-12, and interferon-γ and the activity of reactive oxygen species were increased in the jejunum of piglets in the transport group (P < 0.05 compared with the control group). The concentrations of glutathione peroxidase, claudin-1, occludin, and zonula occludens-1 showed no between-group differences (P > 0.05). Regarding intestinal morphology, the transport group showed infiltration of a small amount of lymphocytes into the jejunum mucosa epithelium that was accompanied by edema of the lamina propria, whereas the control group showed no obvious abnormalities. At the genus level, in the transport group, the 16S rRNA sequencing revealed a downward trend in the relative abundance of Lactobacillus and an upward trend in the relative abundance of Muribaculaceae_unclassified. There was also increased mRNA expression of genes associated with inflammation in the transport group, but the genes and pathways related to apoptosis were not activated. In summary, weaned piglets undergoing 2 h of short-distance road transportation showed stress and inflammatory reactions of the jejunum but did not exhibit oxidative damage or activation of the apoptosis pathway of the jejunum. Furthermore, the growth performance of the piglets was not affected by the trip.

Detecting the selection signatures in Chinese Duroc,Landrace, Yorkshire, Liangshan, and Qingyu pigs

Here we used two kinds of chips data from 5 pig breeds, Chinese Duroc (DD), Landrace (LL), Yorkshire (YY), Liangshan (LS), and Qingyu pigs (QY) in China to identify genes which show evidence of selection during domestication. Four breed pairs, LS-YY, QY-YY, DD-YY, and LL-YY pair, were performed to detect selection signatures using the Fst method. Then we identified a list of genes that played key roles in domestication and artificial selection. For example, the PTPRM gene was shared in LS-YY, QY-YY, and DD-YY pairs and it regulates a variety of cellular processes including cell growth, differentiation as signaling molecules. The HACD3 gene was shared in QY-YY and DD-YY pairs, and the HACD3 protein is involved in the production of very long-chain fatty acids of different chain lengths. Besides, the MYH11 gene that related to muscle contraction was found in LS-YY and LL-YY pair. These results suggested that genes related to immunity, disease resistance, and metabolism were subjected to strong selection pressure in Chinese domestic pigs in the progress of domestication and evolution; however, genes related to appearance, production performance, and reproduction were undergone strong artificial selection in commercial pig breeds.

Functional Amino Acids in Pigs and Chickens: Implication for Gut Health

In pigs and broiler chickens, the gastrointestinal tract or gut is subjected to many challenges which alter performance, animal health, welfare and livability. Preventive strategies are needed to mitigate the impacts of these challenges on gut health while reducing the need to use antimicrobials. In the first part of the review, we propose a common definition of gut health for pig and chickens relying on four pillars, which correspond to the main functions of the digestive tract: (i) epithelial barrier and digestion, (ii) immune fitness, (iii) microbiota balance and (iv) oxidative stress homeostasis. For each pillar, we describe the most commonly associated indicators. In the second part of the review, we present the potential of functional amino acid supplementation to preserve and improve gut health in piglets and chickens. We highlight that amino acid supplementation strategies, based on their roles as precursors of energy and functional molecules, as signaling molecules and as microbiota modulators can positively contribute to gut health by supporting or restoring its four intertwined pillars. Additional work is still needed in order to determine the effective dose of supplementation and mode of administration that ensure the full benefits of amino acids. For this purpose, synergy between amino acids, effects of amino acid-derived metabolites and differences in the metabolic fate between free and protein-bound amino acids are research topics that need to be furtherly investigated.

Management and Feeding Strategies in Early Life to Increase Piglet Performance and Welfare around Weaning: A Review

The performance of piglets in nurseries may vary depending on body weight, age at weaning, management, and pathogenic load in the pig facilities. The early events in a pig's life are very important and may have long lasting consequences, since growth lag involves a significant cost to the system due to reduced market weights and increased barn occupancy. The present review evidences that there are several strategies that can be used to improve the performance and welfare of pigs at weaning. A complex set of early management and dietary strategies have been explored in sows and suckling piglets for achieving optimum and efficient growth of piglets after weaning. The management strategies studied to improve development and animal welfare include: (1) improving sow housing during gestation, (2) reducing pain during farrowing, (3) facilitating an early and sufficient colostrum intake, (4) promoting an early social interaction between litters, and (5) providing complementary feed during lactation. Dietary strategies for sows and suckling piglets aim to: (1) enhance fetal growth (arginine, folate, betaine, vitamin B12, carnitine, chromium, and zinc), (2) increase colostrum and milk production (DL-methionine, DL-2-hydroxy-4-methylthiobutanoic acid, arginine, L-carnitine, tryptophan, valine, vitamin E, and phytogenic actives), (3) modulate sows' oxidative and inflammation status (polyunsaturated fatty acids, vitamin E, selenium, phytogenic actives, and spray dried plasma), (4) allow early microbial colonization (probiotics), or (5) supply conditionally essential nutrients (nucleotides, glutamate, glutamine, threonine, and tryptophan).

Is Dietary 2-Oxoglutaric Acid Effective in Accelerating Bone Growth and Development in Experimentally-Induced Intrauterine Growth Retarded Gilts?

Simple Summary

Intrauterine growth restriction (IUGR) is a significant health issue that not only affects infant mortality or term body weight, but may also predispose individuals to a reduced rate of weight gain and the development of numerous diseases later in life. In livestock production, growth restricted (IUGR) animals require more time to reach slaughter weight. In this study, we examined the effects of long-term administration of 2-oxoglutaric acid (2-Ox) to experimentally-induced intrauterine growth retarded gilts.

Abstract

In this study, the effect of long-term 2-oxoglutaric acid (2-Ox) supplementation to experimentally-induced intrauterine growth retarded gilts was examined. Sows were treated with synthetic glucocorticoid (dexamethasone) every second day, during the last 45 days of pregnancy, at a dose of 0.03 mg/kg b.w. At birth, the gilts were randomly divided into two groups: unsupplemented and supplemented with 2-Ox for nine months (0.4 g/kg body weight/day). Oral supplementation of 2-Ox to experimentally-induced intrauterine growth retarded gilts increased body weight at weaning as well as final body weight at the age of nine months, and showed a regenerative effect on bone mineralization and morphology of trabeculae and articular cartilage. The positive effects on bone structure were attributed to the 2-Ox-induced alterations in bone metabolism, as evidenced by the changes in the expression of proteins involved in bone formation and remodeling: osteocalcin (OC), osteoprotegerin (OPG), receptor activator of nuclear factor kappa-Β ligand (RANKL), tissue inhibitor of metalloproteinases 2 (TIMP-2), bone morphogenetic protein 2 (BMP-2), cartilage oligomeric matrix protein (COMP), and vascular endothelial growth factor (VEGF).

Safety and efficacy of l-glutamine produced using Corynebacterium glutamicum NITE BP-02524 for all animal species

Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of l-glutamine (≥ 98.0%) produced by fermentation using a genetically modified strain of Corynebacterium glutamicum (NITE BP-02524). It is intended to be used in feed for all animal species and categories as nutritional additive (amino acid) and as sensory additive (flavouring compound). Viable cells of the production strain and its recombinant DNA were not detected in the additive. l-Glutamine manufactured by fermentation using C. glutamicum NITE BP-02524 does not give rise to any safety concern with regard to the genetic modification of the production strain. The use of l-glutamine produced by fermentation using C. glutamicum NITE BP-02524 in animal nutrition is considered safe for all animal species when applied as a nutritional additive to achieve an adequate amino acid profile in feed and to overcome potential glutamine shortages during critical periods of life. The proposed use level (25 mg/kg feed) when used as sensory additive (flavouring compound) is safe for all animal species. The uses of l-glutamine produced using C. glutamicum NITE BP-02524 as nutritional additive or as flavouring compound are considered safe for the consumer. l-Glutamine produced using C. glutamicum NITE BP-02524 is not toxic by inhalation, is non-irritant to skin and eyes and is not a skin sensitiser. l-Glutamine produced using C. glutamicum NITE BP-02524 is considered safe for the environment. l-glutamine is a non-essential amino acid and it plays a physiological role as such. Recent evidence shows that glutamine may act as conditionally essential amino acid mainly in growing animals and has some specific effects e.g. in improving intestinal development and immune response. This amino acid produced by fermentation using C. glutamicum NITE BP-02524 is regarded as an efficacious source of glutamine for all animal species. For supplemental l-glutamine to be as efficacious in ruminants as in non-ruminants, it would require protection against degradation in the rumen. The use of l-glutamine as sensory additive at 25 mg/kg feed is considered efficacious.

Influence of Growth Hormone and Glutamine on Intestinal Stem Cells: A Narrative Review

Growth hormone (GH) and glutamine (Gln) stimulate the growth of the intestinal mucosa. GH activates the proliferation of intestinal stem cells (ISCs), enhances the formation of crypt organoids, increases ISC stemness markers in the intestinal organoids, and drives the differentiation of ISCs into Paneth cells and enterocytes. Gln enhances the proliferation of ISCs and increases crypt organoid formation; however, it mainly acts on the post-proliferation activity of ISCs to maintain the stability of crypt organoids and the intestinal mucosa, as well as to stimulate the differentiation of ISCs into goblet cells and possibly Paneth cells and enteroendocrine cells. Since GH and Gln have differential effects on ISCs. Their use in combination may have synergistic effects on ISCs. In this review, we summarize the evidence of the actions of GH and/or Gln on crypt cells and ISCs in the literature. Overall, most studies demonstrated that GH and Gln in combination exerted synergistic effects to activate the proliferation of crypt cells and ISCs and enhance crypt organoid formation and mucosal growth. This treatment influenced the proliferation of ISCs to a similar degree as GH treatment alone and the differentiation of ISCs to a similar degree as Gln treatment alone.

Supplementation of diets with glutamine and glutamic acid attenuated the effects of cold stress on intestinal mucosa and performance of weaned piglets

In this study we investigated the effect of glutamine and glutamic acid inclusion in the diet of weaned piglets subjected to cold stress and thermoneutral environment. Sixty-four weaned piglets were assessed from 28 to 65 days of age. A completely randomised design consisting of a 2 × 2 factorial arrangement was tested – environments (thermoneutral and cold stress) and diets (control and L-glutamine + L-glutamic acid (G + GA)). Performance, relative organ weight and carcass yield, and morphology of the intestinal mucosa were assessed. Supplementing the diets with G + GA reduced feed intake under both environments. This was associated with a decline in growth rate for piglets in the thermoneutral environment but not in the cold environment (P &lt; 0.002). Feed efficiency was lower for piglets offered the control diets in the cold environment, but was significantly improved (24.6%) by G + GA supplementation in the cold but not the thermoneutral environment (P &lt; 0.001). G + GA supplementation decreased small intestinal length and altered intestinal morphology with the highest villus/crypt depth ratio observed in piglets offered the G + GA supplemented diet in the cold environment. In summary, glutamine and glutamic acid diets mitigated the effects of cold stress on the intestinal mucosa and performance of weaned piglets.

Glutamine supplementation improves intestinal cell proliferation and stem cell differentiation in weanling mice

BACKGROUND

Intestinal stem cells can be differentiated into absorptive enterocytes and secretory cells, including Paneth cells, goblet cells, and enteroendocrine cells. Glutamine is a primary metabolic fuel of small intestinal enterocytes and is essential for the viability and growth of intestinal cells.

OBJECTIVE

Whether glutamine supplementation affects the differentiation of intestinal stem cells is unknown.

DESIGN

Three-week-old ICR (Institute of Cancer Research) male mice were divided randomly into two groups: 1) mice receiving a basal diet and normal drinking water and 2) mice receiving a basal diet and drinking water supplemented with glutamine. After 2 weeks, the mice were sacrificed to collect the ileum for analysis.

RESULTS

The study found that glutamine supplementation in weanling mice decreases the crypt depth in the ileum, leading to higher ratio of villus to crypt in the ileum, but promotes cell proliferation of intestinal cells and mRNA expression of Lgr5 (leucine-rich repeat-containing g-protein coupled receptor5) in the ileum. Glutamine has no effect on the number of Paneth cells and goblet cells, and the expression of markers for absorptive enterocytes, Paneth cells, goblet cells, and enteroendocrine cells.

CONCLUSION

These findings reveal the beneficial effects of dietary glutamine supplementation to improve intestinal morphology in weanling mammals.

The Potential Impact of Animal Science Research on Global Maternal and Child Nutrition and Health: A Landscape Review

High among the challenges facing mankind as the world population rapidly expands toward 9 billion people by 2050 is the technological development and implementation of sustainable agriculture and food systems to supply abundant and wholesome nutrition. In many low-income societies, women and children are the most vulnerable to food insecurity, and it is unequivocal that quality nutrition during the first 1000 d of life postconception can be transformative in establishing a robust, lifelong developmental trajectory. With the desire to catalyze disruptive advancements in global maternal and child health, this landscape review was commissioned by the Bill & Melinda Gates Foundation to examine the nutritional and managerial practices used within the food-animal agricultural system that may have relevance to the challenges faced by global human health. The landscape was categorized into a framework spanning 1) preconception, 2) gestation and pregnancy, 3) lactation and suckling, and 4) postweaning and toddler phases. Twelve key findings are outlined, wherein research within the discipline of animal sciences stands to inform the global health community and in some cases identifies gaps in knowledge in which further research is merited. Notable among the findings were 1) the quantitative importance of essential fatty acid and amino acid nutrition in reproductive health, 2) the suggested application of the ideal protein concept for improving the amino acid nutrition of mothers and children, 3) the prospect of using dietary phytase to improve the bioavailability of trace minerals in plant and vegetable-based diets, and 4) nutritional interventions to mitigate environmental enteropathy. The desired outcome of this review was to identify potential interventions that may be worthy of consideration. Better appreciation of the close linkage between human health, medicine, and agriculture will identify opportunities that will enable faster and more efficient innovations in global maternal and child health.

Microbiota-host interplay at the gut epithelial level, health and nutrition

Growing evidence suggests the implication of the gut microbiota in various facets of health and disease. In this review, the focus is put on microbiota-host molecular cross-talk at the gut epithelial level with special emphasis on two defense systems: intestinal alkaline phosphatase (IAP) and inducible heat shock proteins (iHSPs). Both IAP and iHSPs are induced by various microbial structural components (e.g. lipopolysaccharide, flagellin, CpG DNA motifs), metabolites (e.g. n-butyrate) or secreted signal molecules (e.g., toxins, various peptides, polyphosphate). IAP is produced in the small intestine and secreted into the lumen and in the interior milieu. It detoxifies microbial components by dephosphorylation and, therefore, down-regulates microbe-induced inflammation mainly by inhibiting NF-κB pro-inflammatory pathway in enterocytes. IAP gene expression and enzyme activity are influenced by the gut microbiota. Conversely, IAP controls gut microbiota composition both directly, and indirectly though the detoxification of pro-inflammatory free luminal adenosine triphosphate and inflammation inhibition. Inducible HSPs are expressed by gut epithelial cells in proportion to the microbial load along the gastro-intestinal tract. They are also induced by various microbial components, metabolites and secreted molecules. Whether iHSPs contribute to shape the gut microbiota is presently unknown. Both systems display strong anti-inflammatory and anti-oxidant properties that are protective to the gut and the host. Importantly, epithelial gene expressions and protein concentrations of IAP and iHSPs can be stimulated by probiotics, prebiotics and a large variety of dietary components, including macronutrients (protein and amino acids, especially L-glutamine, fat, fiber), and specific minerals (e.g. calcium) and vitamins (e.g. vitamins K1 and K2). Some food components (e.g. lectins, soybean proteins, various polyphenols) may inhibit or disturb these systems. The general cellular and molecular mechanisms involved in the microbiota-host epithelial crosstalk and subsequent gut protection through IAP and iHSPs are reviewed along with their nutritional modulation. Special emphasis is also given to the pig, an economically important species and valuable biomedical model.

Critical review evaluating the pig as a model for human nutritional physiology

The present review examines the pig as a model for physiological studies in human subjects related to nutrient sensing, appetite regulation, gut barrier function, intestinal microbiota and nutritional neuroscience. The nutrient-sensing mechanisms regarding acids (sour), carbohydrates (sweet), glutamic acid (umami) and fatty acids are conserved between humans and pigs. In contrast, pigs show limited perception of high-intensity sweeteners and NaCl and sense a wider array of amino acids than humans. Differences on bitter taste may reflect the adaptation to ecosystems. In relation to appetite regulation, plasma concentrations of cholecystokinin and glucagon-like peptide-1 are similar in pigs and humans, while peptide YY in pigs is ten to twenty times higher and ghrelin two to five times lower than in humans. Pigs are an excellent model for human studies for vagal nerve function related to the hormonal regulation of food intake. Similarly, the study of gut barrier functions reveals conserved defence mechanisms between the two species particularly in functional permeability. However, human data are scant for some of the defence systems and nutritional programming. The pig model has been valuable for studying the changes in human microbiota following nutritional interventions. In particular, the use of human flora-associated pigs is a useful model for infants, but the long-term stability of the implanted human microbiota in pigs remains to be investigated. The similarity of the pig and human brain anatomy and development is paradigmatic. Brain explorations and therapies described in pig, when compared with available human data, highlight their value in nutritional neuroscience, particularly regarding functional neuroimaging techniques.

Developmental expression of STATs, nuclear factor-κB and inflammatory genes in the jejunum of piglets during weaning

The signal transducer and activator of transcription (STAT) proteins play essential roles in apoptosis, proliferation and survival. However, the role of STATs in intestinal inflammation during weaning is unclear. This study aimed to investigate developmental expression of STATs, nuclear factor-κB (NF-κB) and inflammatory genes in the jejunum of piglets during weaning. Thirty-two piglets were weaned at 21d and sacrificed at 0, 1, 7, or 14d (n=8) after weaning. Villus height and the villus height/crypt depth ratio were decreased, whereas crypt depth was increased in the jejunum at 7 and 14d after weaning. In addition, the mRNA levels of interferon-γ (IFN-γ), inducible nitric oxide synthase (iNOS), IL-6, IL-8, IL-12 and IL-22 were increased in the jejunum at 7 and 14d after weaning, whereas transforming growth factor-β (TGF-β), suppressor of cytokine signaling 3 (SCOS3) and arginase-1 was decreased. Neutrophil infiltration was increased in the mucosa of the jejunum after weaning. Moreover, phosphorylation of IκB-α, NF-κB, AKT and STAT-3 was increased. However, the phosphorylation of STAT-1 (at 7 and 14d) and STAT-6 (at 1 and 7d) was suppressed in the jejunum after weaning. Treatment of porcine jejunal epithelial (IPEC-J2) cells with the STAT inhibitors fludarabine, niclosamide and teriflunomide, which inhibit the phosphorylation of STAT-1, STAT-3 and STAT-6, respectively, weakened the defense capacity of these cells against bacterial infection. In conclusion, weaning caused severe inflammation associated with activation of the NF-κB and STAT-3 pathways and suppression of STAT-1 and STAT-6 in the jejunum of piglets.

Alanyl-glutamine supplementation regulates mTOR and ubiquitin proteasome proteolysis signaling pathways in piglets

OBJECTIVE

The aim of the present study was to investigate the effects of the alanyl-glutamine dipeptide (Ala-Gln) or the combination supplementation of free alanine and glutamine (Ala+Gln) on the mammalian target of rapamycin (mTOR) and ubiquitin-proteasome proteolysis (UPP) signaling pathways in piglets.

METHODS

We randomly allocated 180 piglets to three treatments with three replicates of 20 piglets each, fed with diets containing 0.62% Ala, 0.5% Ala-Gln, 0.21% Ala+0.34% Gln, respectively. The duration of the experiment was 28 d.

RESULTS

The results showed that Ala-Gln increased average daily gain of piglets, and decreased the ratio of feed to gain (P < 0.05). Ala-Gln supplementation increased the concentrations of Gln and glutamate and decreased the activity of glutamine synthetase in liver and skeletal muscle (P < 0.05). Ala-Gln increased the expression of glutaminase and glutamate dehydrogenate (P < 0.05). The increased phosphorylation of eIF-4 E binding protein 1 (4E-BP1) and ribosomal protein S6 kinase 1 (S6K1) in Ala-Gln treatment were associated with phosphorylation of the mTOR in liver and skeletal muscle. Ala+Gln did not affect the phosphorylation abundances of mTOR, 4E-BP1, or S6K1 (P > 0.05). Ala-Gln supplementation inhibited the mRNA expressions of MAFbx and MuRF1 in skeletal muscle of piglets (P < 0.05).

CONCLUSION

Taken together, Ala-Gln supplementation improved the growth performance of piglets, enhanced the metabolism of Gln, upregulated protein synthetic signaling in liver and skeletal muscle and decreased protein degradative signaling in muscle of piglets. Moreover, these effects of Ala-Gln were more effective than those of Ala+Gln.

Gut epithelial inducible heat-shock proteins and their modulation by diet and the microbiota

The epidemic of metabolic diseases has raised questions about the interplay between the human diet and the gut and its microbiota. The gut has two vital roles: nutrient absorption and intestinal barrier function. Gut barrier defects are involved in many diseases. Excess energy intake disturbs the gut microbiota and favors body entry of microbial compounds that stimulate chronic metabolic inflammation. In this context, the natural defense mechanisms of gut epithelial cells and the potential to boost them nutritionally warrant further study. One such important defense system is the activation of inducible heat-shock proteins (iHSPs) which protect the gut epithelium against oxidative stress and inflammation. Importantly, various microbial components can induce the expression of iHSPs. This review examines gut epithelial iHSPs as the main targets of microbial signals and nutrients and presents data on diseases involving disturbances of gut epithelial iHSPs. In addition, a broad literature analysis of dietary modulation of gut epithelial iHSPs is provided. Future research aims should include the identification of gut microbes that can optimize gut-protective iHSPs and the evaluation of iHSP-mediated health benefits of nutrients and food components.

Early changes in microbial colonization selectively modulate intestinal enzymes, but not inducible heat shock proteins in young adult Swine

Metabolic diseases and obesity are developing worldwide in a context of plethoric intake of high energy diets. The intestine may play a pivotal role due to diet-induced alterations in microbiota composition and increased permeability to bacterial lipopolysaccharide inducing metabolic inflammation. Early programming of metabolic disorders appearing in later life is also suspected, but data on the intestine are lacking. Therefore, we hypothesized that early disturbances in microbial colonization have short- and long-lasting consequences on selected intestinal components including key digestive enzymes and protective inducible heat shock proteins (HSP). The hypothesis was tested in swine offspring born to control mothers (n = 12) or mothers treated with the antibiotic amoxicillin around parturition (n = 11), and slaughtered serially at 14, 28 and 42 days of age to assess short-term effects. To evaluate long-term consequences, young adult offspring from the same litters were offered a normal or a fat-enriched diet for 4 weeks between 140 and 169 days of age and were then slaughtered. Amoxicillin treatment transiently modified both mother and offspring microbiota. This was associated with early but transient reduction in ileal alkaline phosphatase, HSP70 (but not HSP27) and crypt depth, suggesting a milder or delayed intestinal response to bacteria in offspring born to antibiotic-treated mothers. More importantly, we disclosed long-term consequences of this treatment on jejunal alkaline phosphatase (reduced) and jejunal and ileal dipeptidylpeptidase IV (increased and decreased, respectively) of offspring born to antibiotic-treated dams. Significant interactions between early antibiotic treatment and later diet were observed for jejunal alkaline phosphatase and sucrase. By contrast, inducible HSPs were not affected. In conclusion, our data suggest that early changes in bacterial colonization not only modulate intestinal architecture and function transiently, but also exert site- and sometimes diet-specific long-term effects on key components of intestinal homeostasis.

MicroRNA transcriptome in swine small intestine during weaning stress

MicroRNAs (miRNAs) play important roles in intestinal diseases; however, the role of miRNAs during weaning stress is unknown. In our study, six jejunal small RNA libraries constructed from weaning piglets at 1, 4 and 7 d after weaning (libraries W1, W4 and W7, respectively) and from suckling piglets on the same days as the weaning piglets (libraries S1, S4 and S7, respectively) were sequenced using Solexa high-throughput sequencing technology. Overall, 260 known swine miRNAs and 317 novel candidate miRNA precursors were detected in the six libraries. The results revealed that 16 differentially expressed miRNAs were found between W1 and S1; 98 differentially expressed miRNAs were found between W4 and S4 (ssc-mir-146b had the largest difference); and 22 differentially expressed miRNAs were found between W7 and S7. Sequencing miRNA results were validated using RT-qPCR. Approximately 11,572 miRNA-mRNA interactions corresponding to 3,979 target genes were predicted. The biological analysis further describe that the differentially expressed miRNAs regulated small intestinal metabolisms, stressful responses and immune functions in piglets. Therefore, the small intestine miRNA transcriptome was significantly different between weaning and suckling piglets; the difference varied with the number of days after weaning.

Effect of parenteral administration of glutamine on autophagy of liver cell and immune responses in weaned calves

The objectives of this study were to determine the effects of an increased jugular supply of L-Gln on post-weaning growth, immune responses, intestinal morphology and autophagy of weaned calves. At 35 days of age, 24 Holstein calves (initial 50 ± 1.5 kg; 35 ± 2 day of age) were randomly allocated to four treatments, and each treatment included five male and one female calves. Holstein calves were assigned to treatments of (i) i.v. infusion of 2 l of 0.85% NaCl, Control group [C]; (ii) i.v. infusion of 8 g/day of L-Gln mixed with 2 l of 0.85% NaCl solution [L]; (iii) i.v. infusion of 16 g/day of L-Gln mixed with 2 l of 0.85% NaCl solution [M]; and (iv) i.v. infusion of 32 g/day of L-Gln mixed with 2 l of 0.85% NaCl [H]; The infusion was 2 h/day for each of 14 consecutive days starting on day 1 after weaning. Feed and water were freely available to all calves. All calves were killed on the 14th day post-weaning for measurements of autophagy of liver cell and intestinal morphology. Gln has no effect on dry matter intake (DMI) and average daily gain (ADG). Gln infusion increased quadratically the abundance of CD4+, monocyte and the ratio of CD4+/CD8+. The urea N, Gln and Glucose in plasma increased linearly with increasing Gln loads. Gln infusion increased quadratically villus height and crypt depth of intestine. The autophagy level of liver cell was improved with the Gln infusion dose increased.

Impairment of cellular immunity is associated with overexpression of heat shock protein 70 in neonatal pigs with intrauterine growth retardation

Neonates with intrauterine growth retardation (IUGR) are susceptible to decreases in cellular immunity. In recent years, a growing body of evidence indicates that Hsp70 may serve as a danger signal to the innate immune system and promote receptor-mediated apoptosis. Using neonatal pigs with IUGR, we investigated immune function of pigs and expression of heat shock protein 70 (Hsp70), nuclear factor-kappa B (NF-κB), and forkhead box O 3a (FoxO3a) in the intestinal tract. Samples from the blood, duodenum, jejunum, and ileum of normal body weight (NBW) piglets and IUGR piglets were collected at day 7 after birth. Furthermore, to test whether Hsp70 is associated with regulation of NF-κB and FoxO3a, Hsp70 was silenced using small RNA interference (siRNA) in IEC-6 cells. Body and intestinal weights were lower in IUGR piglets than in NBW piglets (p < 0.05). Proliferation of peripheral blood lymphocytes was decreased (p < 0.05) in IUGR piglets. Cytokine concentrations (IFN-γ, IL-4, IL-10, IL-1, and IL-8) were lower in serum of IUGR piglets. The levels of IFN-γ and IL-10 were decreased (p < 0.05) in the ileum of IUGR piglets, but IL-4 was increased (p < 0.05). The expressions of Hsp70 and FoxO3a were increased, and NF-κB activity was downregulated in IUGR piglets (p < 0.05). Furthermore, siRNA-mediated Hsp70 downregulation increased NF-κB activity, inhibited expression of FoxO3a, and decreased cell apoptosis. In contrast, overexpression of Hsp70 inhibited NF-κB activation. In conclusion, IUGR impairs immune functions in neonatal pigs. An inefficient immunity in IUGR piglets is associated with overexpression of Hsp70, which impairs NF-κB signaling and upregulates FoxO3a expression.