One-to-one relationships between milk miRNA content and protein abundance in neonate duodenum support the potential for milk miRNAs regulating neonate development.

Breast milk plays an essential role for offspring development; however, there lacks evidence of how specific milk components like nucleic acids mechanistically function to regulate neonate development. Previously, we found that maternal high-fat diet (HFD) not only significantly affected mRNA and miRNA content of the secreted milk transcriptome in mice but also affected the duodenal proteome of suckling pups. Here, we hypothesized that nucleic acids differentially expressed in milk of HFD fed dams are related to differentially abundant proteins in offspring duodenum nursed by HFD dams. We tested this hypothesis by analyzing one-to-one relationships in RNA-seq data of milk transcriptomes from control (10% kcal fat) and HFD (60% kcal fat) fed mice and liquid chromatography-tandem mass spectrometry (LC-MS/MS) duodenal proteome data from pups exposed to milk. Ten percent of differentially abundant duodenal proteins between controls and HFD-exposed pups had predicted upregulation or downregulation based on differential milk RNA content. Of these, 76% were targets of upregulated miRNA, and linear regression analysis indicated relationships (p < 0.05) between multiple milk miRNA counts and duodenal protein abundance. Duodenal proteins that were potential targets of milk miRNA enriched Gene Ontology (GO) terms and KEGG pathways related to cytoskeletal structure and neural development, suggesting potential regulation of pup enteric nervous system. One-to-one relationships between milk miRNA content and protein abundance in neonate duodenum support the potential for milk miRNAs regulating neonate development. Identification of milk miRNAs that changed in response to maternal diet will enable design of mechanistic studies that test effects on neonate.

The enteric nervous system undergoes significant chemical and synaptic maturation during adolescence in mice.

Adolescence is a critical period of development. It is very likely that there is significant maturation of the enteric nervous system (ENS) of the gut during this stage of life, especially since there are substantial changes in factors known to influence the ENS including diet and microbiota during this time, but this remains unknown. To examine maturation of the ENS during adolescence, we performed immunohistochemistry using advanced microscopy and analytical methods to compare enteric neurons and glia of the duodenum and colon of mice taken prior to weaning with those of young adult mice. We found significant changes in the architecture of both myenteric and submucosal plexuses and surprisingly found subsets of enteric cells that co-expressed the pan-neuronal marker, Hu, and either glial markers Sox10 or S100ß, not both. About 70% and 35% of all Hu â€‹+ â€‹neurons in the submucous plexus of the young adult duodenum and colon respectively also expressed S100ß. The proportion of Hu+/Sox10 â€‹+ â€‹cells in the duodenal myenteric plexus decreased, while the proportion of Hu+/S100ß+ cells in the colonic submucosal plexus increased during adolescence. In the submucous plexus, there were significant increases in the proportions of vasoactive intestinal peptide+ and choline acetyltransferase â€‹+ â€‹secretomotor neurons, of neurofilament M (NFM)+ neurons in the colon and of calretinin â€‹+ â€‹neurons in the duodenum during adolescence. There were no age-dependent changes in the neurochemistry of various myenteric neuronal subtypes, including those immunoreactive for neuronal nitric oxide synthase (nNOS), Calbindin, Calretinin or NFM. There were significant increases in the somata sizes of Calretinin â€‹+ â€‹submucosal and myenteric neurons, and nNOS â€‹+ â€‹myenteric neurons, and these enteric neurons received significantly more synaptophysin â€‹+ â€‹contacts onto their cell bodies during adolescence. This is the first study showing that enteric neurons and glia in the gut undergo significant changes in their anatomy and chemistry during adolescence. Notably changes in synaptic contacts within the enteric circuitry strongly suggest maturation in gastrointestinal function occurs during this time.

Influence of inclusion level of barley in wheat-based diets and supplementation of carbohydrase on growth performance, nutrient utilisation and gut morphometry in broiler starters.

1. The influence of barley inclusion level and supplementation of a multi-component non-starch polysaccharide degrading enzyme on performance and nutrient utilisation in broilers was investigated. Normal-starch hulled barley was evaluated with five levels of inclusion (0, 141, 283, 424 and 565 g/kg) in a wheat-based diet and two levels of enzyme supplementation (0 and 150 g/tonne of feed; a 5 × 2 factorial arrangement of 10 dietary treatments). All diets were equivalent in metabolisable energy and digestible amino acid contents. A total of 400, one-d old male broilers (five cages/treatment; eight birds/cage) were used in the experiment.2. Regardless of enzyme supplementation, weight gain (WG) increased up to 283 g/kg of barley and was reduced afterwards (P < 0.01). Increasing levels of barley resulted in greater (P < 0.001) gain per feed (G/F). Enzyme addition increased WG (P < 0.05) and G/F (P < 0.001) at each barley inclusion level.3. Birds fed diets with 0 and 565 g/kg barley showed the lowest and highest (P < 0.001to 0.05) digestibility for all nutrients measured, respectively. Digestibility of all nutrients was improved by enzyme supplementation at each barley inclusion level (P < 0.05). The nitrogen-corrected apparent metabolisable energy improved with increasing inclusion of barley (P < 0.001) and supplemental enzyme (P < 0.01). Increasing inclusion of barley increased the relative weight of gizzard (P < 0.001) and reduced jejunal digesta viscosity (P < 0.001). Supplemental enzyme (P < 0.001) reduced digesta viscosity.4. The optimum inclusion level of barley, with respect to growth performance, was 283 g/kg of diet. Increasing barley inclusion improved nutrient and energy utilisation, possibly through lowered digesta viscosity and better function of the gizzard. Feed efficiency and nutrient and energy utilisation can benefit from carbohydrase supplementation in barley-based diets, regardless of barley inclusion level.

Active ß-Catenin Signaling in the Small Intestine of Humans During Infancy.

BACKGROUND: Wnt-ß-catenin signaling is essential for homeostasis of intestinal stem cells in mice and is thought to promote intestinal crypt fission. AIMS: The aim of this study was to investigate Wnt-ß-catenin signaling in intestinal crypts of human infants. METHODS: Duodenal biopsies from nine infants (mean, range 0.9 years, 0.3-2 years) and 11 adults (mean, range 43 years, 34-71 years) were collected endoscopically. Active ß-catenin signaling was assessed by cytoplasmic and nuclear ß-catenin, nuclear c-Myc, and cytoplasmic Axin-2 expression in the base of crypts. Tissues were stained by an immunoperoxidase staining technique and quantified as pixel energy using cumulative signal analysis. Data were expressed as mean ± SD and significance assessed by Student's t test. RESULTS: Crypt fission was significantly higher in infants compared to adults (16 ± 8.6% versus 0.7 ± 0.6%, respectively, p < 0.0001). Expression of cytoplasmic and nuclear ß-catenin was 1.8-fold (p < 0.0001) and 2.9-fold (p < 0.0001) higher in infants, respectively, while cytoplasmic Axin-2 was 3.1-fold (p < 0.0001) increased in infants. c-Myc expression was not significantly different between infants and adults. Expression was absent in Paneth cells but present in the transit amplifying zone of crypts. Crypt base columnar cells, which were intercalated between Paneth cells, expressed c-Myc. CONCLUSIONS: Wnt-ß-catenin signaling was active in crypt base columnar cells (i.e., intestinal stem cells) in human infants. This signaling could promote crypt fission during infancy. Wnt-ß-catenin signaling likely acts in concert with other pathways to promote postnatal growth.

Dietary chlorogenic acid supplementation affects gut morphology, antioxidant capacity and intestinal selected bacterial populations in weaned piglets.

Chlorogenic acid (CGA), an ester formed between caffeic acid and quinic acid, is one of the most abundant phenolic acids and is widespread in fruits, vegetables, cereals and tuber crops. Therefore, the present study was conducted to test the hypothesis that dietary supplementation with CGA could improve intestinal health and regulate intestinal selected microbiota in weaned piglets. A total of twenty-four piglets (21 d of age) were randomly assigned to one of four groups according to their initial BW and sex and fed a basal diet (control group) or a basal diet containing 250, 500 and 1000 mg kg-1 CGA, respectively. The whole trial lasted for 28 d. Dietary CGA supplementation increased (P < 0.05) the duodenal villous height and villous height : crypt depth ratio, but decreased (P < 0.05) the F/G ratio and duodenal crypt depth when compared with the control group. Meanwhile, an increase (P < 0.05) in the jejunal villous height and in the ileal villous height : crypt depth ratio were also observed in CGA-fed piglets. Supplementation with CGA significantly increased (P < 0.05) the activity of serum GSH-Px and the activities of duodenal GSH-Px and CAT, upregulated (P < 0.05) the expression of OCLN in the duodenum and jejunum, and decreased (P < 0.05) the ileal MDA content when compared to the control group. In addition, an increase (P < 0.05) in the population of Lactobacillus and a decrease (P < 0.05) in the population of Escherichia coli were observed in the colon of pigs fed CGA diets. Furthermore, pigs fed CGA diets had higher (P < 0.05) propionic and butyric acid concentrations in the colon. Altogether, our results provide evidence that dietary CGA is beneficial for preserving intestinal morphological integrity and selectively regulating intestinal microbiota, which can provide a means to improve gut health and growth performance post-weaning.

Iron Promotes Intestinal Development in Neonatal Piglets.

Early nutrition is key to promoting gut growth and education of the immune system. Although iron deficiency anemia has long been recognized as a serious iron disorder, the effects of iron supplementation on gut development are less clear. Therefore, using suckling piglets as the model for iron deficiency, we assessed the impacts of iron supplementation on hematological status, gut development, and immunity improvement. Piglets were parenterally supplied with iron dextran (FeDex, 60 mg Fe/kg) by intramuscular administration on the third day after birth and slaughtered at the age of two days, five days, 10 days, and 20 days. It was expected that iron supplementation with FeDex improved the iron status with higher levels of serum iron, ferritin, transferrin, and iron loading in the liver by regulating the interaction of hepcidin and ferroportin (FPN). FeDex supplementation increased villus length and crypt depth, attenuated the pathological status of the duodenum, and was beneficial to intestinal mucosa. FeDex also influenced the intestinal immune development by stimulating the cytokines' production of the intestine and enhancing the phagocytotic capacity of monocytes. Overall, the present study suggested that iron supplementation helped promote the development of the intestine by improving its morphology, which maintains its mucosal integrity and enhances the expression of immuno-associated factors.

Genomic dissection of conserved transcriptional regulation in intestinal epithelial cells.

The intestinal epithelium serves critical physiologic functions that are shared among all vertebrates. However, it is unknown how the transcriptional regulatory mechanisms underlying these functions have changed over the course of vertebrate evolution. We generated genome-wide mRNA and accessible chromatin data from adult intestinal epithelial cells (IECs) in zebrafish, stickleback, mouse, and human species to determine if conserved IEC functions are achieved through common transcriptional regulation. We found evidence for substantial common regulation and conservation of gene expression regionally along the length of the intestine from fish to mammals and identified a core set of genes comprising a vertebrate IEC signature. We also identified transcriptional start sites and other putative regulatory regions that are differentially accessible in IECs in all 4 species. Although these sites rarely showed sequence conservation from fish to mammals, surprisingly, they drove highly conserved IEC expression in a zebrafish reporter assay. Common putative transcription factor binding sites (TFBS) found at these sites in multiple species indicate that sequence conservation alone is insufficient to identify much of the functionally conserved IEC regulatory information. Among the rare, highly sequence-conserved, IEC-specific regulatory regions, we discovered an ancient enhancer upstream from her6/HES1 that is active in a distinct population of Notch-positive cells in the intestinal epithelium. Together, these results show how combining accessible chromatin and mRNA datasets with TFBS prediction and in vivo reporter assays can reveal tissue-specific regulatory information conserved across 420 million years of vertebrate evolution. We define an IEC transcriptional regulatory network that is shared between fish and mammals and establish an experimental platform for studying how evolutionarily distilled regulatory information commonly controls IEC development and physiology.

Vascular Endothelial Growth Factor (VEGF) Bioavailability Regulates Angiogenesis and Intestinal Stem and Progenitor Cell Proliferation during Postnatal Small Intestinal Development.

BACKGROUND: Vascular endothelial growth factor (VEGF) is a highly conserved, master regulatory molecule required for endothelial cell proliferation, organization, migration and branching morphogenesis. Podocoryne carnea and drosophila, which lack endothelial cells and a vascular system, express VEGF homologs, indicating potential roles beyond angiogenesis and vasculogenesis. The role of VEGF in the development and homeostasis of the postnatal small intestine is unknown. We hypothesized regulating VEGF bioavailability in the postnatal small intestine would exhibit effects beyond the vasculature and influence epithelial cell stem/progenitor populations. METHODS: VEGF mutant mice were created that overexpressed VEGF in the brush border of epithelium via the villin promotor following doxycycline treatment. To decrease VEGF bioavailability, sFlt-1 mutant mice were generated that overexpressed the soluble VEGF receptor sFlt-1 upon doxycycline administration in the intestinal epithelium. Mice were analyzed after 21 days of doxycycline administration. RESULTS: Increased VEGF expression was confirmed by RT-qPCR and ELISA in the intestine of the VEGF mutants compared to littermates. The VEGF mutant duodenum demonstrated increased angiogenesis and vascular leak as compared to littermate controls. The VEGF mutant duodenum revealed taller villi and increased Ki-67-positive cells in the transit-amplifying zone with reduced Lgr5 expression. The duodenum of sFlt-1 mutants revealed shorter villi and longer crypts with reduced proliferation in the transit-amplifying zone, reduced expression of Dll1, Bmp4 and VE-cadherin, and increased expression of Sox9 and EphB2. CONCLUSIONS: Manipulating VEGF bioavailability leads to profound effects on not only the intestinal vasculature, but epithelial stem and progenitor cells in the intestinal crypt. Elucidation of the crosstalk between VEGF signaling in the vasculature, mesenchyme and epithelial stem/progenitor cell populations may direct future cell therapies for intestinal dysfunction or disease.

Effects of dietary supplementation with epidermal growth factor-expressing Saccharomyces cerevisiae on duodenal development in weaned piglets.

The aim of the present study was to assess the effects of dietary supplementation with epidermal growth factor (EGF)-expressing Saccharomyces cerevisiae on duodenal development in weaned piglets. In total, forty piglets weaned at 21-26 d of age were assigned to one of the five groups that were provided basic diet (control group) or diet supplemented with S. cerevisiae expressing either empty-vector (INVSc1(EV) group), tagged EGF (T-EGF) (INVSc1-TE(-) group), extracellular EGF (EE-EGF) (INVSc1-EE(+) group) or intracellular EGF (IE-EGF) (INVSc1-IE(+) group). All treatments were delivered as 60·00 µg/kg body weight EGF/d. On 0, 7, 14 and 21 d, eight piglets per treatment were sacrificed to analyse the morphology, activities and mRNA expressions of digestive enzymes, as well as Ig levels (IgA, IgM, IgG) in duodenal mucosa. The results showed significant improvement on 7, 14 and 21 d, with respect to average daily gain (P<0·05), mucosa morphology (villus height and crypt depth) (P<0·05), Ig levels (P<0·01), activities and mRNA expressions of digestive enzymes (creatine kinase, alkaline phosphatase, lactate dehydrogenase and sucrase) (P<0·05) and the mRNA expression of EGF-receptor (P<0·01) in NVSc1-TE(-), INVSc1-EE(+) and INVSc1-IE(+) groups compared with control and INVSc1(EV) groups. In addition, a trend was observed in which the INVSc1-IE(+) group showed an improvement in Ig levels (0·05

Comparative analysis of the morphology and histochemistry of the duodenum of the coypu (Myocastor coypus bonariensis) during its prenatal and postnatal development.

The objective of this study focused on the comparative morphological and histochemical analysis of the duodenum of fetuses, juveniles and adult coypu (Myocastor coypus bonariensis), the major socioeconomic wildlife resource of Argentina. Histological and histochemical procedures for in situ characterization of glycoconjugates (GCs) were used. This study evidenced that fetal mucins differ histochemically in many respects from their adult counterparts. Only in fetuses from 90 days-post coitus (dpc) glycogen-rich sites were observed throughout the duodenal epithelium. The goblet cells appeared from 105 dpc and their secretory content varied considerably after birth. Duodenal glands presented scanty neutral and sulphated GCs in the 30-day juveniles; in adults the proportion of these GCs increased, and carboxylated and sialylated GCs were also observed. The results obtained in this work may be used in future studies to evaluate the effects of diet and intestinal pathologies in the glycosylation pattern of GCs. Also, knowledge of the normal glycoprofile of the duodenum of M. coypus bonariensis during its ontogenetic development may constitute a basis for the study of this organ in other Hystricognathi rodents.

Expression of small intestinal nutrient transporters in embryonic and posthatch turkeys.

Nutrients are absorbed in the small intestine through a variety of transporter proteins, which have not been as well characterized in turkeys as in chickens. The objective of this study was to profile the mRNA expression of amino acid and monosaccharide transporters in the small intestine of male and female turkeys. Jejunum was collected during embryonic development (embryonic d 21 and 24, and d of hatch (DOH)) and duodenum, jejunum, and ileum were collected in a separate experiment during posthatch development (DOH, d 7, 14, 21, and 28). Real-time PCR was used to determine expression of aminopeptidase N (APN), one peptide (PepT1), 6 amino acid (ASCT1, b(o,+)AT, CAT1, EAAT3, LAT1, y(+)LAT2) and 3 monosaccharide (GLUT2, GLUT5, SGLT1) transporters. Data were analyzed by ANOVA using JMP Pro 11.0. APN, b(o,+)AT, PepT1, y(+)LAT2, GLUT5, and SGLT1 showed increased expression from embryonic d 21 and 24 to DOH. During posthatch, all genes except GLUT2 and SGLT1 were expressed greater in females than males. GLUT2 was expressed the same in males as females and SGLT1 was expressed greater in males than females. All basolateral membrane transporters were expressed greater during early development then decreased with age, while the brush border membrane transporters EAAT3, GLUT5, and SGLT1 showed increased expression later in development. Because turkeys showed high-level expression of the anionic amino acid transporter EAAT3, a direct comparison of tissue-specific expression of EAAT3 between chicken and turkey was conducted. The anionic amino acid transporter EAAT3 showed 6-fold greater expression in the ileum of turkeys at d 14 compared to chickens. This new knowledge can be used not only to better formulate turkey diets to accommodate increased glutamate transport, but also to optimize nutrition for both sexes.

The role of mast cell in tissue morphogenesis. Thymus, duodenum, and mammary gland as examples.

Mast cells (MCs) are strategically located at host/environment interfaces like skin, airways, and gastro-intestinal and uro-genital tracts. MCs also populate connective tissues in association with blood and lymphatic vessels and nerves. MCs are absent in avascular tissues, such as mineralized bone, cartilage, and cornea. MCs have various functions and different functional subsets of MCs are encountered in different tissues. However, we do not' know exactly what is the physiological function of MC. Most of these functions are not essential for life, as various MC-deficient strains of mice and rats seems to have normal life spans. In this review article, we have reported and discussed the literature data concerning the role of MCs in tissue morphogenesis, and in particular their role in the development of thymus, duodenum, and mammary gland.

Ontogenic expression of human carboxylesterase-2 and cytochrome P450 3A4 in liver and duodenum: postnatal surge and organ-dependent regulation.

Human carboxylesterase-2 (CES2) and cytochrome P450 3A4 (CYP3A4) are two major drug metabolizing enzymes that play critical roles in hydrolytic and oxidative biotransformation, respectively. They share substrates but may have opposite effect on therapeutic potential such as the metabolism of the anticancer prodrug irinotecan. Both CES2 and CYP3A4 are expressed in the liver and the gastrointestinal tract. This study was conducted to determine whether CES2 and CYP3A4 are expressed under developmental regulation and whether the regulation occurs differentially between the liver and duodenum. A large number of tissues (112) were collected with majority of them from donors at 1-198 days of age. In addition, multi-sampling (liver, duodenum and jejunum) was performed in some donors. The expression was determined at mRNA and protein levels. In the liver, CES2 and CYP3A4 mRNA exhibited a postnatal surge (1 versus 2 months of age) by 2.7 and 29 fold, respectively. CYP3A4 but not CES2 mRNA in certain pediatric groups reached or even exceeded the adult level. The duodenal samples, on the other hand, showed a gene-specific expression pattern at mRNA level. CES2 mRNA increased with age but the opposite was true with CYP3A4 mRNA. The levels of CES2 and CYP3A4 protein, on the other hand, increased with age in both liver and duodenum. The multi-sampling study demonstrated significant correlation of CES2 expression between the duodenum and jejunum. However, neither duodenal nor jejunal expression correlated with hepatic expression of CES2. These findings establish that developmental regulation occurs in a gene and organ-dependent manner.

Whey protein isolate decreases murine stomach weight and intestinal length and alters the expression of Wnt signalling-associated genes.

The present study examined the underlying mechanisms by which whey protein isolate (WPI) affects energy balance. C57BL/6J mice were fed a diet containing 10% energy from fat, 70% energy from carbohydrate (35% energy from sucrose) and 20% energy from casein or WPI for 15 weeks. Mice fed with WPI had reduced weight gain, cumulative energy intake and dark-phase VO2 compared with casein-fed mice (P< 0.05); however, WPI intake had no significant effects on body composition, meal size/number, water intake or RER. Plasma levels of insulin, TAG, leptin, glucose and glucagon-like peptide 1 remained unchanged. Notably, the intake of WPI reduced stomach weight and both length and weight of the small intestine (P< 0.05). WPI intake reduced the gastric expression of Wingless/int-1 5a (Wnt5a) (P< 0.01) and frizzled 4 (Fzd4) (P< 0.01), with no change in the expression of receptor tyrosine kinase-like orphan receptor 2 (Ror2) and LDL receptor-related protein 5 (Lrp5). In the ileum, WPI increased the mRNA expression of Wnt5a (P< 0.01) and caused a trend towards an increase in the expression of Fzd4 (P= 0.094), with no change in the expression of Ror2 and Lrp5. These genes were unresponsive in the duodenum. Among the nutrient-responsive genes, WPI specifically reduced ileal mRNA expression of peptide YY (P< 0.01) and fatty acid transporter protein 4 (P< 0.05), and decreased duodenal mRNA expression of the insulin receptor (P= 0.05), with a trend towards a decreased expression of Na-glucose co-transporter 1 (P= 0.07). The effects of WPI on gastrointestinal Wnt signalling may explain how this protein affects gastrointestinal structure and function and, in turn, energy intake and balance.

Apelin's effects on young rat gastrointestinal tract maturation.

Apelin is considered an important gut regulatory peptide with potential physiological roles in gastrointestinal cytoprotection and regulation of food intake and drinking behavior. The aim of this study was to determine the effects of intraperitoneal or intragastric apelin administration on gastric and intestinal epithelial apoptosis, mitosis and DNA repair enzyme 8-oxoguanine (OGG 1/2) expression in young Wistar rats (50±5 g b.wt.). Apelin-13 was intraperitoneally or intragastrically administered twice a day for 10 days (100 nmol/kg b.wt./2×day), and control groups received physiological saline as a placebo. The rats were sacrificed after treatment, and the gastric fundus, duodenum, middle jejunum and colon tissue samples were harvested for immunofluorescence studies. Intragastric administration of apelin-13 increased the apoptotic index in the stomach and colon tissues (P≤0.001) but decreased apoptosis in the duodenum and jejunum (P<0.001); this approach reduced the number of mitotic cells in the jejunum and colon but increased mitoses (P<0.001) in the duodenum. Finally, intragastric apelin-13 increased (P<0.001) OGG 1/2 enzyme expression in the stomach and jejunum and decreased its expression in the colon (P<0.01). However, intraperitoneal apelin-13 injection caused the opposite effect in the same regions of the gastrointestinal tract. In conclusion, apelin inhibits gastrointestinal tissue maturation in young rats, regardless of the administration route. However, further studies are required to clarify the mechanism of apelin action on gastrointestinal tract maturation in young rats.

Loss of Slc26a9 anion transporter alters intestinal electrolyte and HCO3(-) transport and reduces survival in CFTR-deficient mice.

Slc26a9 is an anion transporter that is strongly expressed in the stomach and lung. Slc26a9 variants were recently found associated with a higher incidence of meconium ileus in cystic fibrosis (CF) infants, raising the question whether Slc26a9 is expressed in the intestine and what its functional role is. Slc26a9 messenger RNA (mRNA) was found highly expressed in the mucosae of the murine and human upper gastrointestinal tract, with an abrupt decrease in expression levels beyond the duodenum. Absence of SLC26a9 expression strongly increased the intestinally related mortality in cystic fibrosis transmembrane conductance regulator (CFTR)-deficient mice. Proximal duodenal JHCO3(-) and fluid secretion were reduced in the absence of Slc26a9 expression. In the proximal duodenum of young Slc26a9 KO mice, the glands and villi/crypts were elongated and proliferation was enhanced. This difference was lost with ageing, as were the alterations in fluid movement, whereas the reduction in JHCO3(-) remained. Laser dissection followed by qPCR suggested Slc26a9 expression to be crypt-predominant in the duodenum. In summary, deletion of Slc26a9 caused bicarbonate secretory and fluid absorptive changes in the proximal duodenal mucosa and increased the postweaning death rates in CFTR-deficient mice. Functional alterations in the duodenum were most prominent at young ages. We assume that the association of meconium ileus and Slc26a9 variants may be related to maldigestion and impaired downstream signaling caused by loss of upper GI tract digestive functions, aggravating the situation of lack of secretion and sticky mucus at the site of obstruction in CF intestine.

Ghrelin receptors in human gastrointestinal tract during prenatal and early postnatal development.

The aim of our study was to investigate the appearance, density and distribution of ghrelin cells and GHS-R1a and GHS-R1b in the human stomach and duodenum during prenatal and early postnatal development. We examined chromogranin-A and ghrelin cells in duodenum, and GHS-R1a and GHS-R1b expression in stomach and duodenum by immunohistochemistry in embryos, fetuses, and infants. Chromogranin-A and ghrelin cells were identified in the duodenum at weeks 10 and 11 of gestation. Ghrelin cells were detected individually or clustered within the base of duodenal crypts and villi during the first trimester, while they were presented separately within the basal and apical parts of crypts and villi during the second and third trimesters. Ghrelin cells were the most numerous during the first (∼11%) and third (∼10%) trimesters of gestation development. GHS-R1a and GHS-R1b were detected at 11 and 16 weeks of gestation, showed the highest level of expression in Brunner's gland and in lower parts of duodenal crypts and villi during the second trimester in antrum, and during the third trimester in corpus and duodenum. Our findings demonstrated for the first time abundant duodenal expression of ghrelin cells and ghrelin receptors during human prenatal development indicating a role of ghrelin in the regulation of growth and differentiation of human gastrointestinal tract.

Coated zinc oxide improves intestinal immunity function and regulates microbiota composition in weaned piglets.

The present study was conducted to test the hypothesis that low concentrations of coated ZnO, as a substitute for a high concentration of ZnO (2250 mg Zn/kg), could improve intestinal immunity function and regulate microbiota composition, thus alleviating the incidence of diarrhoea in weaned piglets. A total of eighty-four cross-bred piglets, weaned at an age of 28 (SEM 1) d, were allocated randomly, on the basis of average initial body weight (7·72 (SEM 0·65) kg), to seven treatment groups as follows: a 250 mg Zn (ZnO)/kg group (low Zn; LZ) and a 2250 mg Zn (ZnO)/kg group (high Zn; HZ) that were offered diets containing ZnO at 250 and 2250 mg Zn/kg, respectively; and five experimental groups in which coated ZnO was added at 250, 380, 570, 760 and 1140 mg Zn/kg basal diet, respectively. The trial lasted 2 weeks. The results indicated that, compared with LZ treatment, supplementation with coated ZnO at 380 or 570 mg Zn/kg reduced (P< 0·05) diarrhoea index, increased (P< 0·05) duodenal villus height and the ratio of villus height:crypt depth, up-regulated (P< 0·05) the gene expression of insulin-like growth factor 1, zonula occludens protein-1, occludin, IL-10 and transforming growth factor ß1, and elevated (P< 0·05) secretory IgA concentration in the jejunal mucosa. Microbiota richness and the Shannon diversity index were also decreased (P< 0·05). Furthermore, piglets in the group fed coated ZnO at 380 or 570 mg Zn/kg did not differ from those in the HZ-fed group in relation to the aforementioned parameters. Collectively, a low concentration of coated ZnO (380 or 570 mg Zn/kg) can alleviate the incidence of diarrhoea by promoting intestinal development, protecting the intestinal mucosal barrier from damage, stimulating the mucosal immune system and regulating the microbiota composition.

Nutrigenetics of carotenoid metabolism in the chicken: a polymorphism at the ß,ß-carotene 15,15'-mono-oxygenase 1 (BCMO1) locus affects the response to dietary ß-carotene.

The enzyme ß,ß-carotene-15,15'-mono-oxygenase 1 (BCMO1) is responsible for the symmetrical cleavage of ß-carotene into retinal. We identified a polymorphism in the promoter of the BCMO1 gene, inducing differences in BCMO1 mRNA levels (high in adenines (AA) and low in guanines (GG)) and colour in chicken breast muscle. The present study was designed to test whether this polymorphism could affect the response to dietary ß-carotene. Dietary ß-carotene supplementation did not change the effects of the genotypes on breast muscle properties: BCMO1 mRNA levels were lower and xanthophyll contents higher in GG than in AA chickens. Lower vitamin E levels in the plasma and duodenum, plasma cholesterol levels and body weight were also observed in GG than in AA chickens. In both genotypes, dietary ß-carotene increased vitamin A storage in the liver; however, it reduced numerous parameters such as SCARB1 (scavenger receptor class B type I) in the duodenum, BCMO1 in the liver, vitamin E levels in the plasma and tissues, xanthophyll contents in the pectoralis major muscle and carcass adiposity. However, several diet × genotype interactions were observed. In the GG genotype, dietary ß-carotene increased ISX (intestine-specific homeobox) and decreased BCMO1 mRNA levels in the duodenum, decreased xanthophyll concentrations in the duodenum, liver and plasma, and decreased colour index and HDL-cholesterol concentration in the plasma. Retinol accumulation following dietary ß-carotene supplementation was observed in the duodenum of AA chickens only. Therefore, the negative feedback control on ß-carotene conversion through ISX appears as functional in the duodenum of GG but not of AA chickens. This could result in a higher availability of ß-carotene in the duodenum of GG chickens, reducing the uptake of xanthophylls, liposoluble vitamins and cholesterol.

Intestinal microbiota influence the early postnatal development of the enteric nervous system.

BACKGROUND: Normal gastrointestinal function depends on an intact and coordinated enteric nervous system (ENS). While the ENS is formed during fetal life, plasticity persists in the postnatal period during which the gastrointestinal tract is colonized by bacteria. We tested the hypothesis that colonization of the bowel by intestinal microbiota influences the postnatal development of the ENS. METHODS: The development of the ENS was studied in whole mount preparations of duodenum, jejunum, and ileum of specific pathogen-free (SPF), germ-free (GF), and altered Schaedler flora (ASF) NIH Swiss mice at postnatal day 3 (P3). The frequency and amplitude of circular muscle contractions were measured in intestinal segments using spatiotemporal mapping of video recorded spontaneous contractile activity with and without exposure to lidocaine and N-nitro-L-arginine (NOLA). KEY RESULTS: Immunolabeling with antibodies to PGP9.5 revealed significant abnormalities in the myenteric plexi of GF jejunum and ileum, but not duodenum, characterized by a decrease in nerve density, a decrease in the number of neurons per ganglion, and an increase in the proportion of myenteric nitrergic neurons. Frequency of amplitude of muscle contractions were significantly decreased in the jejunum and ileum of GF mice and were unaffected by exposure to lidocaine, while NOLA enhanced contractile frequency in the GF jejunum and ileum. CONCLUSIONS & INFERENCES: These findings suggest that early exposure to intestinal bacteria is essential for the postnatal development of the ENS in the mid to distal small intestine. Future studies are needed to investigate the mechanisms by which enteric microbiota interact with the developing ENS.