Intestinal Alkaline Phosphatase Research Articles

Radiation-induced changes in intestinal and tissue-nonspecific alkaline phosphatase: implications for recovery after radiation therapy

BackgroundExogenous replacement of depleted enterocyte intestinal alkaline phosphatase (IAP) decreases intestinal injury in models of colitis. We determined whether radiation-induced intestinal injury could be mitigated by oral IAP supplementation and the impact on tissue-nonspecific AP. MethodsWAG/RjjCmcr rats (n = 5 per group) received lower hemibody irradiation (13 Gy) followed by daily gavage with phosphate-buffered saline or IAP (40 U/kg/d) for 4 days. Real-time polymerase chain reaction, AP activity, and microbiota analysis were performed on intestine. Lipopolysaccharide and cytokine analysis was performed on serum. Data were expressed as a mean ± SEM with P greater than .05 considered significant. ResultsIntestine of irradiated animals demonstrates lower hemibody irradiation and is associated with upregulation of tissue-nonspecific AP, downregulation of IAP, decreased AP activity, and altered composition of the intestinal microbiome. ConclusionsSupplemental IAP after radiation may be beneficial in mitigating intestinal radiation syndrome as evidenced by improved histologic injury, decreased acute intestinal inflammation, and normalization of intestinal microbiome.

Alkaline Phosphatase, Soluble Extracellular Adenine Nucleotides, and Adenosine Production after Infant Cardiopulmonary Bypass.

RationaleDecreased alkaline phosphatase activity after infant cardiac surgery is associated with increased post-operative cardiovascular support requirements. In adults undergoing coronary artery bypass grafting, alkaline phosphatase infusion may reduce inflammation. Mechanisms underlying these effects have not been explored but may include decreased conversion of extracellular adenine nucleotides to adenosine.Objectives1) Evaluate the association between alkaline phosphatase activity and serum conversion of adenosine monophosphate to adenosine after infant cardiac surgery; 2) assess if inhibition/supplementation of serum alkaline phosphatase modulates this conversion.Methods and ResearchPre/post-bypass serum samples were obtained from 75 infants <4 months of age. Serum conversion of 13C5-adenosine monophosphate to 13C5-adenosine was assessed with/without selective inhibition of alkaline phosphatase and CD73. Low and high concentration 13C5-adenosine monophosphate (simulating normal/stress concentrations) were used. Effects of alkaline phosphatase supplementation on adenosine monophosphate clearance were also assessed. Changes in serum alkaline phosphatase activity were strongly correlated with changes in 13C5-adenosine production with or without CD73 inhibition (r = 0.83; p<0.0001). Serum with low alkaline phosphatase activity (≤80 U/L) generated significantly less 13C5-adenosine, particularly in the presence of high concentration 13C5-adenosine monophosphate (10.4μmol/L vs 12.9μmol/L; p = 0.0004). Inhibition of alkaline phosphatase led to a marked decrease in 13C5-adenosine production (11.9μmol/L vs 2.7μmol/L; p<0.0001). Supplementation with physiologic dose human tissue non-specific alkaline phosphatase or high dose bovine intestinal alkaline phosphatase doubled 13C5-adenosine monophosphate conversion to 13C5-adenosine (p<0.0001).ConclusionsAlkaline phosphatase represents the primary serum ectonucleotidase after infant cardiac surgery and low post-operative alkaline phosphatase activity leads to impaired capacity to clear adenosine monophosphate. AP supplementation improves serum clearance of adenosine monophosphate to adenosine. These findings represent a potential therapeutic mechanism for alkaline phosphatase infusion during cardiac surgery.New and NoteworthyWe identify alkaline phosphatase (AP) as the primary soluble ectonucleotidase in infants undergoing cardiopulmonary bypass and show decreased capacity to clear AMP when AP activity decreases post-bypass. Supplementation of AP ex vivo improves this capacity and may represent the beneficial therapeutic mechanism of AP infusion seen in phase 2 studies.

Effects of dietary live and heat-inactive baker's yeast on growth, gut health, and disease resistance of Nile tilapia under high rearing density.

In this study, the effects of baker's yeast as probiotics was evaluated in Nile tilapia reared at high density. Juvenile tilapia were distributed to tanks at high density (436fish/m(3)) and fed with basal diet (CK) or diets supplemented with live (LY) or heat-inactivated yeast (HIY). Another group of fish reared at low density (218fish/m(3)) and fed with basal diet was also included (LowCK). After 8 weeks of feeding, growth, feed utilization, gut microvilli morphology, digestive enzymes, and expressions of hsp70 and inflammation-related cytokines in the intestine were assessed. Intestinal microbiota was investigated using 16S rRNA gene pyrosequencing. Fish were challenged with Aeromonas hydrophila to evaluate disease resistance. High rearing density significantly decreased the growth, feed utilization, microvilli length, and disease resistance of fish (CK versus LowCK). Moreover, the intestinal hsp70 expression was increased in fish reared at high density, supporting a stress condition. Compared to CK group, supplementation of live yeast significantly increased gut microvilli length and trypsin activity, decreased intestinal hsp70 expression, and enhanced resistance of fish against A.hydrophila (reflected by reduced intestinal alkaline phosphatase activity 24h post infection). The gut microbiota was not markedly influenced by either rearing density or yeast supplementation. Heat-inactivated yeast (HIY) didn't display the beneficial effects observed in LY except an increase in gut trypsin activity, suggesting the importance of yeast viability and thus secretory metabolites of yeast. In conclusion, live baker's yeast may alleviate the negative effects induced by crowding stress, and has the potential to be used as probiotics for tilapia reared at high density.

Effects of chito-oligosaccharide on intestinal mucosal amino acid profiles and alkaline phosphatase activities, and serum biochemical variables in weaned piglets

The present experiment was conducted to determine the effects of chito-oligosaccharide (COS) on intestinal mucosal amino acid profiles and alkaline phosphatase (ALP) activities, and serum biochemical variables in weaned piglets. A total of 24 piglets (BW=7.82±0.21kg) were weaned at 25 d of age and were blocked by body weight, sex, and litter and randomly assigned to one of two treatments consisting of a basal diet (CON) or the basal diet supplemented with 30mg/kg COS for a 14-d period. Each treatment was assigned to 6 pens (2 piglets/pen) and 6 piglets (3 males and 3 females) were randomly selected from each treatment (1 pigs/pen) for blood and tissue sampling. Dietary supplementation with COS increased (P<0.05) serum IgG and urea nitrogen contents, and tended to increase (P<0.10) serum calcium. The ileal mucosal ALP activity in piglets fed with COS diet were greater (P<0.05) than that in CON piglets. Dietary supplementation with COS increased (P<0.05) the contents of Asn and Cys, and tended to increase (P<0.10) the contents of Asp and Orn in the small intestinal mucosa of weaned piglets. Moreover, the contents of short chain fatty acid (SCFA) in caecal and colonic digesta of weaned piglets were affected (P<0.05) by dietary COS supplementation. There were interactions (P<0.05) between dietary COS and intestinal section for mucosal AA contents and digesta SCFA contents in weaned piglets. In conclusion, the results of the present experiment suggest that dietary supplementation with COS affects intestine and immune functions of weaned piglets.

Development and in vitro evaluation of zeta potential changing self-emulsifying drug delivery systems for enhanced mucus permeation

The aim of this study was the development of zeta potential changing self-emulsifying drug delivery systems (SEDDS). Various cationic surfactants were incorporated into a formulation consisting of 30% Cremophor EL, 30% Capmul MCM, 30% Captex 355 and 10% propylene glycol (w/w). A substrate of intestinal alkaline phosphatase (IAP), 1,2-dipalmitoyl-sn-glycero-3-phosphatidic acid sodium (PA), was thereafter incorporated into SEDDS. Size, zeta potential and polydispersity index were determined. Phosphate release studies were performed using three different models, namely, isolated IAP, Caco-2 cell monolayer and rat intestinal mucosa and the amount of released phosphate was quantified by malachite green assay. Interaction of SEDDS and mucus was investigated regarding surface charges and mucus diffusion studies were performed using rotating tube technique. SEDDS were diluted 1:100 in 100mM HEPES buffer and a negative zeta potential was obtained. By addition of isolated IAP, 15% to 20% phosphate was liberated from SEDDS within 3h and a shift of zeta potential from negative to positive was observed. On Caco-2 cell monolayer and rat intestinal mucosa, 12% and 23% phosphate were released, respectively, from SEDDS diluted 1:1000 in glucose-HEPES buffer. Positively charged droplets were bound to negatively charged mucus resulting in a decrease of zeta potential, whereas negatively charged SEDDS showed no interaction. Furthermore, negatively charged SEDDS diffused faster through mucus layer as higher extent of incorporated Lumogen was present in deeper mucus segments in comparison to positively charged ones. Accordingly, zeta potential changing SEDDS provide an effective mucus permeation combined with higher cellular uptake when droplets reach absorptive epithelium membrane.

Role of intestinal alkaline phosphatase in calcium absorption

Role of intestinal alkaline phosphatase in calcium absorption

Charge changing phosphorylated polymers: Proof of in situ mucoadhesive properties

The objective of this study was to design a novel polyethylene glycol (PEG) derivative exhibiting mucus permeating and mucoadhesive properties. Therefore, the enzymatically degradable phosphate ester, phosphotyrosine (Ptyr) was covalently attached to PEG-diamine. The synthesized PEG-Ptyr was studied in terms of enzymatic degradability on Caco 2 cells and by isolated intestinal alkaline phosphatase (IAP). Furthermore, the influence of enzymatic degradation on charge distribution of the polymer as well as on mucus diffusion and mucoadhesion was investigated. Within this study, the phosphate ester in PEG-Ptyr could be cleaved on the cell monolayer and by the isolated IAP, whereby the degradation rate was 10-fold higher utilizing the isolated enzyme. Implementation of negative charges on PEG due to modification with Ptyr led to an increased electrophoretic mobility, which was reduced after enzymatic degradation of the phosphate ester, most likely due to the alterations in charge distribution on the polymeric backbone. Interactions with mucus components were determined within mucus diffusion studies and rheological investigations. Herein, PEG-Ptyr showed a 3-fold lower mucus diffusion, after incubation with IAP. Within rheological investigations, dynamic viscosities increased by the factor of 3, after the phosphate ester in PEG-Ptyr was degraded by IAP. Results obtained within these experiments provided evidence for the in situ mucoadhesive properties of charge changing phosphorylated polymers. The combination of mucus permeating and mucoadhesive features of phosphorylated PEGs could be a highly interesting tool for future applications, such as for coating nanoparticles.

Blood lead levels and markers of renal dysfunction among mechanical workshop workers

The role of lead (Pb) as an environmental cause of nephropathy is difficult to ascertain due to the difficulty to determine clinically its exposure. To assess lead levels and renal function in a group of males working in mechanical workshops. Blood and urine samples were obtained from 100 mechanical workshop workers aged 38 ± 16 years and 95 non-exposed office clerks aged 37 ± 17 years. Blood lead and creatinine levels were determined. In exposed workers, urinary excretion of intestinal alkaline phosphatases (IAP) and N-acetyl-glucosaminidase (NAG) were measured as early markers of renal failure. Blood lead levels were 66.4 ± 43 and 33.6 ± 18 µg/L among mechanical workshop workers and non-exposed controls, respectively, p < 0.01. The figures for serum creatinine were 0.9 ± 0.1 and 0.9 ± 0.1 respectively, p = NS. Among exposed workers urinary excretion of IAP was 0.47 ± 0.6 U/L and of NAG, 0.92 ± 1.1 U/L. There was a positive correlation between blood lead levels and NAG excretion (r = 0.284) and IAP excretion (r = 0.346). Exposed workers had higher blood lead levels and there was a weak positive association between these levels and the urinary excretion of NAG and IAP.

Effects of dietary curcumin supplementation on growth performance, intestinal digestive enzyme activities and antioxidant capacity of crucian carp Carassius auratus

A 105-day feeding trial was carried out to investigate the effects of dietary curcumin (CM) supplementation on growth performance, digestive enzyme activities, and intestinal antioxidant capacity of crucian carp (Carassius auratus). A total of 585 crucian carp with average initial weight of 76.3±0.10g were fed three diets supplemented with 0 (basal group), 1, or 5gkg−1 CM. Fish fed the diet supplemented with 5gkg−1 CM showed significantly higher final body weight (FW), percent weight gain (PWG), and feed efficiency (FE) compares to those fed the basal or 1gkg−1 CM diet (P<0.05). Feed intake and body composition were not significantly different among dietary groups (P>0.05). The hepatopancreas weight, hepatopancreas protein content, intestinal weight, intestinal somatic index, intestine protein content, trypsin and lipase activities in hepatopancreas and intestine, amylase activity in hepatopancreas, Na+, K+-ATPase (NKA), alkaline phosphatase (AKP), gamma-glutamyl transpeptidase (γ-GT), and creatine kinase (CK) activities in intestine were significantly increased with dietary CM supplementation at 5gkg−1 (P<0.05). Fish fed the 5gkg−1 CM diet showed significantly lower malondialdehyde and protein carbonyl contents in the intestine (P<0.05). Superoxide anion and hydroxy radical scavenging ability, glutathione reducase (GR), catalase (CAT), total superoxide dismutase (T-SOD), glutathione peroxidase (GPx), and glutathione-S-transferase (GST) activities, and glutathione (GSH) content in the intestine were significantly increased with increased CM. The relative mRNA expressions of trypsin, lipase, NKA, AKP, γ-GT, CK, SOD1, CAT, GPx, GST, and GR in intestine were significantly up-regulated by dietary CM supplementation at 5gkg−1. These results suggested that dietary CM supplementation increased intestinal antioxidant capacity, digestive and absorptive ability, and promoted fish growth.

Unfolding and inactivation of proteins by counterions in protein-nanoparticles interaction

In this work, the structure and activity of proteins; such as, hen egg lysozyme (HEWL) and calf intestine alkaline phosphatase (CIAP); have been investigated after incubation with surface coated iron oxide nanoparticles (IONPs) in water. IONPs were coated with counterions bound charge-ligands and were named as the charge-ligand counterions iron oxide nanoparticles (CLC-IONPs). The coating was done with tri-lithium citrate (TLC) and tri-potassium citrate (TKC) to have negative surface charge of CLC-IONPs and Li+ and K+, respectively, as counterions. To have positive surface charge, IONPs were coated with cetylpyridinium chloride (CPC) and cetylpyridinium iodide (CPI) having Cl− and I−, respectively, as counterions. The secondary structure of proteins was measured using far ultraviolet circular dichroism (CD) spectroscopy which showed that both proteins were irreversibly unfolded after incubation with CLC-IONPs. The unfolded proteins were seen to be functionally inactive, as confirmed through their activity assays, i.e., HEWL with Escherichia coli (E. coli) and CIAP with para-nitrophenyl phosphate (pNPP). Additionally, we have observed that monomeric hemoglobin (Hb) from radio-resistant insect Chironomus ramosus (ChHb) was also partially unfolded upon interaction with CLC-IONPs. This work clearly shows the role of counterions in protein inactivation via protein-nanoparticles interaction and, therefore, CLC-IONPs could be used for therapeutic purpose.

Dairy products and the French paradox: Could alkaline phosphatases play a role?

The French paradox – high saturated fat consumption but low incidence of cardiovascular disease (CVD) and mortality – is still unresolved and continues to be a matter of debate and controversy. Recently, it was hypothesised that the high consumption of dairy products, and especially cheese by the French population might contribute to the explanation of the French paradox, in addition to the “(red) wine” hypothesis. Most notably this would involve milk bioactive peptides and biomolecules from cheese moulds. Here, we support the “dairy products” hypothesis further by proposing the “alkaline phosphatase” hypothesis. First, intestinal alkaline phosphatase (IAP), a potent endogenous anti-inflammatory enzyme, is directly stimulated by various components of milk (e.g. casein, calcium, lactose and even fat). This enzyme dephosphorylates and thus detoxifies pro-inflammatory microbial components like lipopolysaccharide, making them unable to trigger inflammatory responses and generate chronic low-grade inflammation leading to insulin resistance, glucose intolerance, type-2 diabetes, metabolic syndrome and obesity, known risk factors for CVD. Various vitamins present in high amounts in dairy products (e.g. vitamins A and D; methyl-donors: folate and vitamin B12), and also fermentation products such as butyrate and propionate found e.g. in cheese, all stimulate intestinal alkaline phosphatase. Second, moulded cheeses like Roquefort contain fungi producing an alkaline phosphatase. Third, milk itself contains a tissue nonspecific isoform of alkaline phosphatase that may function as IAP. Milk alkaline phosphatase is present in raw milk and dairy products increasingly consumed in France. It is deactivated by pasteurization but it can partially reactivate after thermal treatment. Experimental consolidation of the “alkaline phosphatase” hypothesis will require further work including: systematic alkaline phosphatase activity measurements in dairy products, live dairy ferments and intestine of model animals. Furthermore, stool residual IAP, a possible early marker of diabetes, should be assayed in human cohorts. If confirmed, this “alkaline phosphatase” hypothesis will highlight the protective effects of milk alkaline phosphatase and promote the consumption of (microbiologically safe) raw milk and dairy products. Microorganisms secreting alkaline phosphatases may be privileged as ferments in dairy products.

Effects of dietary Lactobacillus plantarum and AHL lactonase on the control of Aeromonas hydrophila infectionin tilapia.

This study addressed the effects of dietary Lactobacillus plantarum or/and N‐acylated homoserine lactonase (AHL lactonase) on controlling Aeromonas hydrophila infection in juvenile hybrid tilapia (Oreochromis niloticus♀ × O. aureus ♂). Fish were fed Lb. plantarum subsp. plantarum strain JCM1149 (108 CFU/g feed) or/and AHL lactonase AIO6 (4 U/g) and were exposed to a chronic challenge of A. hydrophila NJ‐1 (105 cells/mL) for 14 days. Intestinal (foregut) alkaline phosphatase (IAP) activities were evaluated 1 day post challenge to reflect the resistance of fish against A. hydrophila infection. Parallel groups of fish with the same dietary assignments while unchallenged were also included to investigate the effect of dietary Lb. plantarum or/and AIO6 supplementation on gut health of tilapia. The results showed that IAP activity was significantly lower in fish fed with diets supplemented with Lb. plantarum JCM1149 or the combination of Lb. plantarum JCM1149 and AIO6, indicating enhanced resistance against A. hydrophila. Light microscopy and transmission electron microscopy images of foregut revealed damage caused by A. hydrophila NJ‐1, but dietary Lb. plantarum JCM1149 or/and AIO6 significantly alleviated the damages. Compared to the fish immersed in A. hydrophila NJ‐1, dietary Lb. plantarum JCM1149 or AIO6 could maintain the microvilli length in the foregut of tilapia. However, among the unchallenged groups of fish, the microvilli length in the foregut of tilapia fed AIO6 (singly or combination) and the microvilli density of tilapia fed AIO6 (singly) were significantly lower than those of the control, though the microvilli density in the combination treatment was significantly improved. Additionally, the dietary Lb. plantarum JCM1149 could down‐regulate the expression of stress‐related gene in the gut after the acute phase. In conclusion, the dietary Lb. plantarum JCM1149 is recommended to control the A. hydrophila infection in tilapia.

Dietary Lipid Type, Rather Than Total Number of Calories, Alters Outcomes of Enteric Infection in Mice.

Dietary lipids modulate immunity, yet the means by which specific fatty acids affect infectious disease susceptibility remains unclear. Deciphering lipid-induced immunity is critical to understanding the balance required for protecting against pathogens while avoiding chronic inflammatory diseases. To understand how specific lipids alter susceptibility to enteric infection, we fed mice isocaloric, high-fat diets composed of corn oil (rich in n-6 polyunsaturated fatty acids [n-6 PUFAs]), olive oil (rich in monounsaturated fatty acids), or milk fat (rich in saturated fatty acids) with or without fish oil (rich in n-3 PUFAs). After 5 weeks of dietary intervention, mice were challenged with Citrobacter rodentium, and pathological responses were assessed. Olive oil diets resulted in little colonic pathology associated with intestinal alkaline phosphatase, a mucosal defense factor that detoxifies lipopolysaccharide. In contrast, while both corn oil and milk fat diets resulted in inflammation-induced colonic damage, only milk fat induced compensatory protective responses, including short chain fatty acid production. Fish oil combined with milk fat, unlike unsaturated lipid diets, had a protective effect associated with intestinal alkaline phosphatase activity. Overall, these results reveal that dietary lipid type, independent of the total number of calories associated with the dietary lipid, influences the susceptibility to enteric damage and the benefits of fish oil during infection.

Evaluation of Schizochytrium meal in microdiets of Pacific white shrimp ( Litopenaeus vannamei ) larvae

A feeding trial was conducted to assess the effects of dietary Schizochytrium meal supplementation on survival, growth performance, activities of digestive enzymes and fatty acid composition in Pacific white shrimp (Litopenaeus vannamei) larvae (initial body weight 4.21 ± 0.10 mg). Four isonitrogenous and isolipidic diets were formulated to contain graded levels of Schizochytrium meal: 0% (S0, the control diet), 2% (S2), 4% (S4) and 6% dry matter (S6). Results showed that there was no significant difference in survival of shrimps among dietary treatments (P > 0.05). Shrimps fed diets with 2% and 4% microalgae meal had significantly higher specific growth rate (SGR) than that of shrimps fed diets with 0% and 6% microalgae meal, and no significant differences were observed between shrimps fed diets with 2% and 4% microalgae meal (P > 0.05). Activity of trypsin in the pancreatic and intestinal segments, and activity of amylase in the pancreatic segments were not significantly affected by dietary microalgae meal levels (P > 0.05). Specific activities of both alkaline phosphatase and leucine-aminopeptidase in intestine and purified brush border membrane of intestine were significantly higher in shrimps fed diet with 2% microalgae meal (P < 0.05). There were no significant differences in C18:2n-6, n-3 fatty acids, n-6fatty acids, PUFA and n-3/n-6 in muscle samples among dietary treatments. C16:1n-7, C18:1n-9, MUFA, C18:3n-3 and C20:5n-3 decreased, however, C20:4n-6 increased in the muscle as dietary microalgae meal level increased. In conclusion, 4% Schizochytrium meal in microdiets of shrimps can improve growth performance and may be a valuable additive in the microdiets of shrimps.

Dairy Milk Components Differentially Affect Gastrointestinal Health Markers in C57Bl/6 Mice

Impaired gastrointestinal health is thought to play a causative role in chronic systemic inflammation leading to disease. The effects of individual protein sources, namely isolated soy protein (ISP), dried whole milk powder (DWMP), milk fat globule membrane (MFGM) or milk protein concentrate (MPC), on intestinal health was studied using 3 cohorts of C57BL/6J mice (n=5/diet group in each cohort) following 13 weeks of test diet feeding. Isocaloric and isonitrogenous diets provided 20% energy as protein, 50% as carbohydrate and 30% energy as fat. MFGM‐fed mice were heaviest (p&lt;0.005); however, growth rates (avg. daily weight gain), feed efficiency and overall gut motility were similar. Global indicators of gut health including FITC‐dextran assessed permeability, plasma endotoxin and plasma cytokines IFN‐γ, IL‐1β, IL‐6, IL‐12p70, MIP‐2 and eotaxin were similar among treatments. Plasma TNF‐α was increased in MPC‐fed mice (p&lt;0.01) over ISP (40‐fold) and DWMP (10‐fold), albeit intestinal gene expression of TNF‐α in MPC‐fed mice (n=5) was 1/3 of that in ISP‐fed mice and reduced compared to all diet groups (p&lt;0.01). IgA concentrations were increased in MFGM‐fed mice (287 μg/mL) over all diet groups (DWMP = 213 μg/mL, MPC = 199 μg/mL, ISP = 162 μg/mL; p&lt;0.0001). Plasma IL‐10 was similar among groups (n=15/diet, p&lt;0.4). Cecal concentrations of acetate, proprionate, isobutyrate, isovalerate, and valerate were similar. Butyrate (μg/g cecal content) was lowest in MPC‐fed mice (p&lt;0.001) but this difference did not persist when expressed as % of total SCFAs; butyrate comprised 16.7% in all diet groups. Acetate:butyrate was lowest in DWMP (5.20), and less (p&lt;0.04) than MPC (9.46), but similar to that of MFGM (6.92) and ISP (5.78). Morphological analysis of intestines, alkaline phosphatase and myeloperoxidase activities and inflammatory gene expressions were measured in a subset of mice (n=5). Villus height in distal small intestine was shortest in ISP‐fed mice (237 μm), greatest in MFGM‐fed mice (305 μm; p&lt;0.000, 28% increase) and 268 μm in DWMP and 280 μm in MPC. Expression of inflammatory marker genes TLR5, NFκB, MyD88, and apoA1 were similar in distal small intestine from all diet groups while TLR4 expression was increased 2‐fold in MFGM compared to ISP (p&lt;0.06, n=5). Myeloperoxidase activity, a marker of neutrophil infiltration, increased &gt;370% in distal colons of ISP‐fed mice (36.3 μU/mL, n=5) compared to dairy‐fed mice (8.76 μU/mL, n = 5; p&lt;0.006). Intestinal alkaline phosphatase did not differ between diet groups (p&lt;0.07). Within the context of a US Dietary Guidelines macronutrient distribution, protein source appears to differentially affect intestinal health markers in C57Bl/6 mice; dairy protein components have distinct nutritional functionalities. Funding provided by National Dairy Council project #1120 administered by Dairy Research Institute.Support or Funding InformationFunding provided by National Dairy Council project #1120 administered by Dairy Research Institute.

Prevention of antibiotic-associated metabolic syndrome in mice by intestinal alkaline phosphatase.

To examine whether co-administration of intestinal alkaline phosphatase (IAP) with antibiotics early in life may have a preventive role against metabolic syndrome (MetS) in mice. A total of 50 mice were allocated to four treatment groups after weaning. Mice were treated with azithromycin (AZT) ± IAP, or with no AZT ± IAP, for three intermittent 7-day cycles. After the last treatment course, the mice were administered a regular chow diet for 5 weeks and subsequently a high-fat diet for 5 weeks. Body weight, food intake, water intake, serum lipids, glucose levels and liver lipids were compared. 16S rRNA gene pyrosequencing was used to determine the differences in microbiome composition. Exposure to AZT early in life rendered mice susceptible to MetS in adulthood. Co-administration of IAP with AZT completely prevented this susceptibility by decreasing total body weight, serum lipids, glucose levels and liver lipids to the levels of control mice. These effects of IAP probably occur as a result of changes in the composition of specific bacterial taxa at the genus and species levels (e.g. members of Anaeroplasma and Parabacteroides). Co-administration of IAP with AZT early in life prevents mice from susceptibility to the later development of MetS. This effect is associated with alterations in the composition of the gut microbiota. IAP may represent a novel treatment against MetS in humans.

Oral antibodies to human intestinal alkaline phosphatase reduce dietary phytate phosphate bioavailability in the presence of dietary 1α-hydroxycholecalciferol

While it is well established that active vitamin D treatment increases dietary phytate phosphate utilization, the mechanism by which intestinal alkaline phosphatase (IAP) participates in phytate phosphate use is less clear. The ability of human IAP (hIAP) oral antibodies to prevent dietary phytate phosphate utilization in the presence of 1α-hydroxycholecalciferol (1α-(OH) D3) in a chick model was investigated. hIAP specific chicken immunoglobulin Y (IgY) antibodies were generated by inoculating laying hens with 17 synthetic peptides derived from the human IAP amino acid sequence and harvesting egg yolk. Western blot analysis showed all antibodies recognized hIAP and 6 of the 8 antibodies selected showed modest inhibition of hIAP activity in vitro (6 to 33% inhibition). In chicks where dietary phosphate was primarily in the form of phytate, 4 selected hIAP antibodies inhibited 1α-(OH) D3-induced increases in blood phosphate, one of which, generated against selected peptide (MFPMGTPD), was as effective as sevelamer hydrochloride in preventing the 1α-(OH) D3-induced increase in blood phosphate, but ineffective in preventing an increase in body weight gain and bone ash induced by 1α-(OH) D3. These studies demonstrated that orally-delivered antibodies to IAP limit dietary phytate-phosphate utilization in chicks treated with 1α-(OH) D3, and implicate IAP as an important host enzyme in increasing phytate phosphate bioavailability in 1α-(OH) D3 fed chicks.

Apple-Derived Pectin Modulates Gut Microbiota, Improves Gut Barrier Function, and Attenuates Metabolic Endotoxemia in Rats with Diet-Induced Obesity.

This study was aimed at determining potential effects of apple-derived pectin on weight gain, gut microbiota, gut barrier and metabolic endotoxemia in rat models of diet-induced obesity. The rats received a standard diet (control; Chow group; n = 8) or a high-fat diet (HFD; n = 32) for eight weeks to induce obesity. The top 50th percentile of weight-gainers were selected as diet induced obese rats. Thereafter, the Chow group continued on chow, and the diet induced obese rats were randomly divided into two groups and received HFD (HF group; n = 8) or pectin-supplemented HFD (HF-P group; n = 8) for six weeks. Compared to the HF group, the HF-P group showed attenuated weight gain (207.38 ± 7.96 g vs. 283.63 ± 10.17 g, p < 0.01) and serum total cholesterol level (1.46 ± 0.13 mmol/L vs. 2.06 ± 0.26 mmol/L, p < 0.01). Compared to the Chow group, the HF group showed a decrease in Bacteroidetes phylum and an increase in Firmicutes phylum, as well as subordinate categories (p < 0.01). These changes were restored to the normal levels in the HF-P group. Furthermore, compared to the HF group, the HF-P group displayed improved intestinal alkaline phosphatase (0.57 ± 0.20 vs. 0.30 ± 0.19, p < 0.05) and claudin 1 (0.76 ± 0.14 vs. 0.55 ± 0.18, p < 0.05) expression, and decreased Toll-like receptor 4 expression in ileal tissue (0.76 ± 0.58 vs. 2.04 ± 0.89, p < 0.01). The HF-P group also showed decreased inflammation (TNFα: 316.13 ± 7.62 EU/mL vs. 355.59 ± 8.10 EU/mL, p < 0.01; IL-6: 51.78 ± 2.35 EU/mL vs. 58.98 ± 2.59 EU/mL, p < 0.01) and metabolic endotoxemia (2.83 ± 0.42 EU/mL vs. 0.68 ± 0.14 EU/mL, p < 0.01). These results suggest that apple-derived pectin could modulate gut microbiota, attenuate metabolic endotoxemia and inflammation, and consequently suppress weight gain and fat accumulation in diet induced obese rats.

M1 Macrophages Activate Notch Signalling in Epithelial Cells: Relevance in Crohn's Disease.

The Notch signalling pathway plays an essential role in mucosal regeneration, which constitutes a key goal of Crohn's disease (CD) treatment. Macrophages coordinate tissue repair and several phenotypes have been reported which differ in the expression of surface proteins, cytokines and hypoxia-inducible factors (HIFs). We analysed the role of HIFs in the expression of Notch ligands in macrophages and the relevance of this pathway in mucosal regeneration. Human monocytes and U937-derived macrophages were polarized towards the M1 and M2 phenotypes and the expression levels of HIF-1α, HIF-2α, Jagged 1 (Jag1) and delta-like 4 (Dll4) were evaluated. The effects of macrophages on the expression of hairy and enhancer of split-1 (HES1, the main target of Notch signalling) and intestinal alkaline phosphatase (IAP, enterocyte marker) in epithelial cells in co-culture were also analysed. Phenotype macrophage markers and Notch signalling were evaluated in the mucosa of CD patients. M1 macrophages were associated with HIF-1-dependent induction of Jag1 and Dll4, which increased HES1 protein levels and IAP activity in co-cultured epithelial cells. In the mucosa of CD patients a high percentage of M1 macrophages expressed both HIF-1α and Jag1 while M2 macrophages mainly expressed HIF-2α and we detected a good correlation between the ratio of M1/M2 macrophages and both HES1 and IAP protein levels. M1, but not M2, macrophages are associated with HIF-1-dependent induction of Notch ligands and activation of epithelial Notch signalling pathway. In the mucosa of chronic CD patients, the prevalence of M2 macrophages is associated with diminution of Notch signalling and impaired enterocyte differentiation.

Effect of neonatal β(3)-adrenoceptor agonist CL 316,243 treatment on body fat accumulation and intestinal alkaline phosphatase activity in rats from reduced nests.

The aim of this study was to evaluate the effects of early life administration of β3-adrenoceptor agonist (CL 316,243) on somatic and feeding parameters, obesity development as well as small intestinal enzyme activity in 21- and 40-day-old overfed male Sprague-Dawley rats. To induce postnatal overnutrition, litter size was reduced to 4 pups/litter (small litters, SL); while in normally-nourished groups (NL) the litter size was adjusted to 10 pups/litter. From days 5 to 15, half of the suckling pups from NL and SL groups received CL 316,243 subcutaneously. From 21st to 40th day, in the post-weaning period, both control (NL, SL) and CL 316,243-treated (NL-CL, SL-CL) rats had free access to standard diet and water. Body composition was determined by magnetic resonance imaging, blood pressure was measured using non-invasive tail-cuff, and intestinal alkaline phosphatase (AP) activity was assessed by histochemistry. At 21 and 40 days of age the SL rats showed higher body mass, displayed higher adiposity and had significantly increased duodenal and jejunal AP activity compared with NL animals. On day 21, NL and SL rats treated with CL 316,243 showed significantly less fat deposition and jejunal AP activity than the non-treated controls. In contrast, treatment-related changes in adiposity and AP activity were not observed in 40-day-old NL-CL, SL-CL rats. These results indicate that early pharmacological intervention with CL did not permanently influence physiological processes involved in body weight/fat regulation, which resulted in the development of early-programmed overweight status in SL rats after weaning.