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1.
Mol Nutr Food Res ; 67(14): e2200389, 2023 07.
Article in English | MEDLINE | ID: mdl-37084231

ABSTRACT

SCOPE: High-fat diet (HFD) intake induces gut dysbiosis, inflammation in the peripheral tissues, and a reduction in immunoglobulin A (IgA) coating of gut bacteria, which is related to HFD-induced insulin resistance (IR). This study evaluates the effect of cyclic nigerosylnigerose (CNN), a dietary fiber that prevents gut inflammation and promotes IgA coating of gut bacteria, on the above-mentioned HFD-induced disorders. METHODS AND RESULTS: Balb/c mice are fed an HFD and administered CNN for 20 weeks. CNN administration reduces mesenteric adipose tissue weight, colonic tumor necrosis factor α (TNFα) mRNA expression, and serum endotoxin levels and ameliorates HFD-induced abnormal glucose metabolism. Additionally, CNN administration promotes gut bacteria-specific IgA secretion and alters IgA reactivity to gut bacteria. The alterations of IgA reactivity to specific bacteria such as Erysipelatoclostridium, Escherichia, Faecalibaculum, Lachnospiraceae genera, and Stenotrophomonas are correlated with mesenteric adipose tissue weight, colonic TNFα mRNA expression, serum endotoxin levels, and a homeostasis model assessment for IR. CONCLUSION: CNN-induced alterations in IgA reactivity to gut bacteria may be related to the suppression of HFD-induced fat deposition, colonic inflammation, endotoxemia, and IR. These observations indicate that dietary fiber that modulates IgA reactivity to gut bacteria may be useful in preventing HFD-induced disorders.


Subject(s)
Glucose , Insulin Resistance , Mice , Animals , Immunoglobulin A , Tumor Necrosis Factor-alpha/genetics , Diet, High-Fat/adverse effects , Inflammation , Bacteria , Endotoxins , Dietary Fiber , RNA, Messenger , Mice, Inbred C57BL
2.
Biosci Biotechnol Biochem ; 86(6): 780-791, 2022 May 24.
Article in English | MEDLINE | ID: mdl-35348590

ABSTRACT

Cyclic nigerosylnigerose (CNN) syrup, containing 76% water-soluble dietary fiber, was prepared from starch on an industrial scale, using isoamylase, 6-α-glucosyltransferase, 3-α-isomaltosyltransferase, and cyclodextrin glucanotransferase. CNN syrup has a unique linkage pattern, consisting mainly of α-1,3 and α-1,6 glucoside linkages, and is characterized by its low weight average molecular weight (807) and moderate sweetness (relative sweetness = 25), unlike in well-known dietary fiber materials. The glass transition temperature of CNN is higher than that of the straight chain structures, maltotetraose and maltosyltrehalose. Even when 40% of normally added sucrose was replaced with CNN syrup, sponge cake puffed up sufficiently. The no observed adverse effect level for a single dose of CNN syrup was 0.88 and 0.89 g dry solid/kg body weight for men and women, respectively. The increase in blood glucose and insulin concentrations during consumption of CNN syrup was lower than that of glucose.


Subject(s)
Dietary Fiber , Glucans , Female , Humans , Male , Starch/chemistry , Sucrose
3.
Biosci Biotechnol Biochem ; 85(6): 1485-1491, 2021 May 25.
Article in English | MEDLINE | ID: mdl-33881472

ABSTRACT

Cyclic nigerosylnigerose (CNN) is a cyclic tetrasaccharide with properties distinct from those of other conventional cyclodextrins. We investigated the relative available energy of CNN in healthy humans. CNN digestibility was determined using brush border membrane vesicles from the small intestines of rats. CNN was not hydrolyzed by rat intestinal enzymes. To investigate breath hydrogen excretion, 13 human subjects were included in a double-blind cross-over, randomized, placebo-controlled study. The effects of CNN on hydrogen excretion were compared with those of a typical nondigestible, fermentable fructooligosaccharide (FOS). In the study participants, hydrogen excretion hardly increased upon CNN and was remarkably lower than for FOS. The available energy value was determined using the fermentability based on breath hydrogen excretion and was evaluated as 0 kcal/g for CNN. CNN was hardly metabolized and hence may be used as a low-energy dietary fiber.


Subject(s)
Energy Metabolism , Glucans/metabolism , Adult , Breath Tests , Double-Blind Method , Female , Fermentation , Humans , Hydrogen/metabolism , Male
4.
Biosci Biotechnol Biochem ; 85(7): 1746-1752, 2021 Jun 24.
Article in English | MEDLINE | ID: mdl-33913465

ABSTRACT

High-molecular-weight dextrin (WS-1000) was produced from waxy corn starch and enzymatically modified to link glucose by α-1,6 glycosidic bond at the terminal point of the glucose chain, forming MWS-1000. In this study, the physical properties of MWS-1000 were characterized, and the advantages of its use as a food modifier were described. From rheological and calorimetric studies, it was found that MWS-1000 does not undergo retrogradation, but it does not prevent the retrogradation of WS-1000, suggesting that they have no intermolecular interaction in solution. Investigation of the effect of MWS-1000 on the viscoelasticity of gelatinized wheat starch showed that in the linear viscoelastic region, storage modulus decreased and tan δ increased with increase in replaced MWS-1000 content. In addition, it was confirmed that gelatinized starch containing MWS-1000 showed viscoelastic behavior similar to that of commercially available custard cream.


Subject(s)
Dextrins/biosynthesis , Food Technology , Glucosyltransferases/metabolism , Elasticity , Molecular Weight , Starch/chemistry , Viscosity
6.
Biosci Microbiota Food Health ; 39(3): 188-196, 2020.
Article in English | MEDLINE | ID: mdl-32775139

ABSTRACT

Cyclic nigerosylnigerose (CNN) is a cyclic oligosaccharide. Oral administration of CNN promotes immunoglobulin A (IgA) secretion in the gut. IgA is a major antibody secreted into the gut and plays a crucial role in suppressing gut inflammation due to commensal gut microbiota. To investigate the effect of administration of CNN to promote IgA secretion on gut inflammation, experimental colitis was induced with dextran sulfate sodium (DSS) in Balb/c mice after 6 weeks of CNN pre-feeding. The severity of colitis was evaluated based on a disease activity index (DAI), the gene expression of inflammatory cytokines, and a histological examination. The CNN-treated mice with DSS-induced colitis (CNN-DSS group) showed significantly lower DAI scores and mRNA levels of interleukin-1 compared with the CNN-untreated mice with DSS-induced colitis (DSS group). Histological examination of the colon revealed that the pathological score was significantly lower in the CNN-DSS group compared with the DSS group due to the reduced infiltration of immune cells. The number of goblet cells was significantly higher in the CNN-DSS group compared with the DSS group. The IgA concentration and the ratio of microbiota coated with IgA were evaluated in the cecal content. Although there was no difference in the IgA concentration among groups, a higher proportion of cecal microbiota were coated with IgA in the CNN-DSS group compared with that in the DSS group. These results suggest that CNN might preserve goblet cells in the colon and promote IgA coating of gut microbiota, which synergistically ameliorate gut inflammation in mice with DSS-induced colitis.

7.
Nutr J ; 19(1): 68, 2020 07 09.
Article in English | MEDLINE | ID: mdl-32646428

ABSTRACT

BACKGROUND: Trehalose is a natural disaccharide that is widely distributed. A previous study has shown that daily consumption of 10 g of trehalose improves glucose tolerance in individuals with signs of metabolic syndrome. In the present study, we determined whether a lower dose (3.3 g/day) of trehalose improves glucose tolerance in healthy Japanese volunteers. METHODS: This was a randomized, double-blind, placebo-controlled study of healthy Japanese participants (n = 50). Each consumed 3.3 g of trehalose (n = 25) or sucrose (n = 25) daily for 78 days. Their body compositions were assessed following 0, 4, 8, and 12 weeks; and serum biochemical parameters were assayed and oral 75-g glucose tolerance tests were performed at baseline and after 12 weeks. RESULTS: There were similar changes in body composition and serum biochemistry consistent with established seasonal variations in both groups, but there were no differences in any of these parameters between the two groups. However, whereas after 12 weeks of sucrose consumption, the plasma glucose concentration 2 h after a 75-g glucose load was significantly higher than the fasting concentration, after 12 weeks of trehalose consumption the fasting and 2-h plasma glucose concentrations were similar. Furthermore, an analysis of the participants with relatively high postprandial blood glucose showed that the plasma glucose concentration 2 h after a 75-g glucose load was significantly lower in the trehalose group than in the sucrose group. CONCLUSIONS: Our findings suggest that trehalose helps lower postprandial blood glucose in healthy humans with higher postprandial glucose levels within the normal range, and may therefore contribute to the prevention of pathologies that are predisposed to by postprandial hyperglycemia,, even if the daily intake of trehalose is only 3.3 g, an amount that is easily incorporated into a meal. TRIAL REGISTRATION: UMIN, UMIN000033536 . Registered 27 July 2018.


Subject(s)
Insulin , Trehalose , Blood Glucose , Cross-Over Studies , Double-Blind Method , Glucose , Healthy Volunteers , Homeostasis , Humans , Postprandial Period
8.
Nutr Metab (Lond) ; 17: 22, 2020.
Article in English | MEDLINE | ID: mdl-32206077

ABSTRACT

BACKGROUND: Trehalose is a functional disaccharide that has anti-metabolic activities such as suppression of adipocyte hypertrophy in mice and alleviation of impaired glucose tolerance in humans. Trehalase hydrolyzes trehalose in the small intestine into two glucose molecules. In this study, we investigated whether trehalose can suppress adipocyte hypertrophy in mice in the presence or absence of trehalase. METHODS: Trehalase knockout (KO) mice and wild-type (WT) mice were fed a high fat diet (HFD) and administered water with 0.3% (w/v) or without trehalose for 8 weeks. At the end of the experimental period, mesenteric adipose tissues and the small intestine were collected and the adipocyte size and proportion of cytoplasmic lipid droplets (CLDs, %) in jejunum epithelium were measured by image analysis. RESULTS: Trehalose treatment was associated with suppressed adipocyte hypertrophy in both trehalase KO and WT mice. The rate of CLDs in the jejunal epithelium was increased in both trehalase KO and WT mice given water containing trehalose relative to untreated control mice. There was a negative correlation between jejunal epithelial lipid droplet volume and mesenteric adipocyte size. Chylomicron-TG tended to be decreased in both trehalose-treated trehalase KO and WT mice. Addition of trehalose to differentiated Caco-2 cells in vitro increased intracytoplasmic lipid droplets and decreased secretion of the chylomicron marker ApoB-48. Moreover, the jejunal epithelium containing lipid droplets falled into the intestinal lumen, and triglyceride (TG) levels in feces tended to be higher in the KO/HFD/Tre group than in the KO/HFD/Water group. Since then, the accumulation of CLDs has been reported to suppress CM secretion, and along with our results, the effect of trehalose to increase jejunum CLDs may induce adipocyte hypertrophy. CONCLUSIONS: The suppression of adipocyte hypertrophy in the presence and absence of trehalase indicates that trehalose mediates effects prior to being hydrolyzed into glucose. In both trehalase KO and WT mice, trehalose treatment increased the rate of CLDs in jejunal epithelium, reduced chylomicron migration from the intestinal epithelium to the periphery, and suppressed adipocyte hypertrophy. Thus, trehalose ingestion could prevent metabolic syndrome by trapping fat droplets in the intestinal epithelium and suppressing rapid increases in chylomicrons.

9.
Nutr Metab (Lond) ; 16: 45, 2019.
Article in English | MEDLINE | ID: mdl-31346340

ABSTRACT

BACKGROUND: Trehalose is well known as a functional disaccharide with anti-metabolic activities such as suppression of adipocyte hypertrophy in mice and alleviation of impaired glucose tolerance in humans. Recently, a new type of adipocyte beige cells, involved in so-called white adipocyte tissue (WAT) browning, has received much attention as a target for adaptive thermogenesis. To clarify the relationship between adipocyte hypertrophy suppression and beige cells involved in thermogenesis, we examined the effect of trehalose on the changes in beige adipocytes in mice under normal dietary conditions. METHODS: Mice fed a normal diet were administered water containing 0.3% (W/V) trehalose for 16 weeks, 0.3% (W/V) maltose, or water without saccharide (controls). Body temperature and non-fasting blood glucose levels were measured every 3 weeks. After 16 weeks of these treatments, mesenteric and inguinal adipose tissues were collected for measuring adipocyte size, counting the number of UCP1 positive cells by image analysis, and preparing mRNA to analyze beige adipocyte-related gene expression. RESULTS: Mice administered a continuous intake of trehalose exhibited a thermogenic ability as represented by an increase in rectal temperature, which was maintained at a relatively high level from 3 to 9 weeks and was significantly higher at 15 weeks in comparison with that of the maltose group. In addition to the reduced hypertrophy of mesenteric and inguinal adipose tissues, the trehalose group showed a significant increase in the rates of beige adipocytes in each WAT in comparison with those of the maltose and the water groups. Interestingly, a negative correlation was found between the mean cell sizes of adipocytes and the rates of beige adipocytes in the WAT. Furthermore, real-time PCR showed that the expression of Cidea and Ucp1 mRNAs, which are markers for beige adipocytes in the inguinal adipose tissue, increased in the trehalose group. CONCLUSIONS: Continuous administration of trehalose to mice fed a normal diet induced WAT browning accompanied by suppression of white adipocyte hypertrophy, elevated body temperature and decreased blood glucose levels, which resulted in enhancement of energy metabolism. Therefore, we propose trehalose as a new type of thermogenic dietary component to prevent obesity by promoting WAT browning.

10.
Nutr J ; 16(1): 9, 2017 Feb 06.
Article in English | MEDLINE | ID: mdl-28166771

ABSTRACT

BACKGROUND: Trehalose is hydrolyzed by a specific intestinal brush-border disaccharidase (trehalase) into two glucose molecules. In animal studies, trehalose has been shown to prevent adipocyte hypertrophy and mitigate insulin resistance in mice fed a high-fat diet. Recently, we found that trehalose improved glucose tolerance in human subjects. However, the underlying metabolic responses after trehalose ingestion in humans are not well understood. Therefore, we examined the glycemic, insulinemic and incretin responses after trehalose ingestion in healthy Japanese volunteers. METHODS: In a crossover study, 20 fasted healthy volunteers consumed 25 g trehalose or glucose in 100 mL water. Blood samples were taken frequently over the following 3 h, and blood glucose, insulin, active gastric inhibitory polypeptide (GIP) and active glucagon-like peptide-1 (GLP-1) levels were measured. RESULTS: Trehalose ingestion did not evoke rapid increases in blood glucose levels, and had a lower stimulatory potency of insulin and active GIP secretion compared with glucose ingestion. Conversely, active GLP-1 showed higher levels from 45 to 180 min after trehalose ingestion as compared with glucose ingestion. Specifically, active GIP secretion, which induces fat accumulation, was markedly lower after trehalose ingestion. CONCLUSIONS: Our findings indicate that trehalose may be a useful saccharide for good health because of properties that do not stimulate rapid increases in blood glucose and excessive secretion of insulin and GIP promoting fat accumulation.


Subject(s)
Blood Glucose/metabolism , Healthy Volunteers , Incretins/blood , Insulin/blood , Trehalose/administration & dosage , Adult , Asian People , Body Mass Index , Cross-Over Studies , Female , Gastric Inhibitory Polypeptide/blood , Glucagon-Like Peptide 1/blood , Humans , Insulin Resistance , Male , Middle Aged , Young Adult
11.
J Nutr Sci Vitaminol (Tokyo) ; 62(6): 380-387, 2016.
Article in English | MEDLINE | ID: mdl-28202842

ABSTRACT

We previously performed animal studies that suggested that trehalose potentially prevents the development of metabolic syndrome in humans. To evaluate this possibility, we examined whether trehalose suppressed the progression of insulin resistance in a placebo-controlled, double-blind trial in 34 subjects with a body mass index (BMI) ≥23. The subjects were divided into two groups and were assigned to ingest either 10 g/d of trehalose or sucrose with meals for 12 wk. During the study, body composition and blood biochemical parameters were measured at week 0, 8, and 12. These parameters were also measured 4 wk after the end of intake to confirm the washout of test substances. In the trehalose group, blood glucose concentrations after a 2-h oral glucose tolerance test significantly decreased following 12 wk of intake in comparison with baseline values (0 wk). When a stratified analysis was performed in the subjects whose percentage of truncal fat approached the high end of the normal range, the change in body weight, waist circumference, and systolic blood pressure were significantly lower in the trehalose group than in the sucrose group. Our data indicated that a daily intake of 10 g of trehalose improved glucose tolerance and progress to insulin resistance. Furthermore, these results suggested that trehalose can potentially reduce the development of metabolic syndrome and associated lifestyle-related diseases, such as type 2 diabetes.


Subject(s)
Diabetes Mellitus, Type 2/prevention & control , Metabolic Syndrome/prevention & control , Trehalose/administration & dosage , Adult , Blood Glucose/metabolism , Body Composition , Body Mass Index , Body Weight , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/drug therapy , Dose-Response Relationship, Drug , Double-Blind Method , Female , Glycated Hemoglobin/metabolism , Humans , Insulin/blood , Insulin Resistance , Life Style , Male , Metabolic Syndrome/blood , Metabolic Syndrome/drug therapy , Middle Aged , Risk Factors , Trehalose/blood , Waist Circumference
12.
J Nutr Sci Vitaminol (Tokyo) ; 59(5): 393-401, 2013.
Article in English | MEDLINE | ID: mdl-24418873

ABSTRACT

Our group recently demonstrated that simultaneous administration of trehalose with a high-fat diet (HFD) suppresses adipocyte hypertrophy and mitigates insulin resistance in mice. For the present study, we hypothesized that similar effects of trehalose would be observed in mice with previously-established obesity. Obese mice were fed a HFD and drinking water containing 0.3 or 2.5% (weight/volume) trehalose or distilled water (DW) ad libitum for 8 wk. After 7 wk intake of a HFD and trehalose, fasting serum insulin levels and homeostasis model assessment-insulin resistance (HOMA-IR) in the 0.3% Tre/HFD group were significantly lower than those in the DW/HFD group (p<0.05). After 8 wk of treatment, mesenteric adipocytes in the 0.3% Tre/HFD group showed significantly less hypertrophy than those in the DW/HFD group. Mechanistic analysis indicated that levels of high molecular weight (HMW) adiponectin in the serum of the 0.3% Tre/HFD group were significantly higher than those in the DW/HFD group. The expression levels of insulin receptor substrate-1 (IRS-1) and insulin receptor substrate-2 (IRS-2) messenger RNA (mRNA) in muscle were also significantly increased by trehalose intake. Our data therefore suggest that administration of trehalose to obese mice mitigates insulin resistance by suppressing adipocyte hypertrophy and increasing serum HMW adiponectin, resulting in upregulation of IRS-1, and IRS-2 expression in muscle. These results further suggest that trehalose is a functional saccharide that may be used to prevent the progression of insulin resistance.


Subject(s)
Dietary Supplements , Hyperinsulinism/diet therapy , Insulin Resistance , Intra-Abdominal Fat/pathology , Metabolic Syndrome/prevention & control , Obesity/physiopathology , Trehalose/therapeutic use , Adiponectin/agonists , Adiponectin/blood , Adiponectin/metabolism , Adiposity , Animals , Diet, High-Fat/adverse effects , Female , Gene Expression Regulation , Hyperinsulinism/etiology , Hyperinsulinism/pathology , Hyperinsulinism/physiopathology , Hypertrophy , Insulin Receptor Substrate Proteins/agonists , Insulin Receptor Substrate Proteins/genetics , Insulin Receptor Substrate Proteins/metabolism , Intra-Abdominal Fat/metabolism , Metabolic Syndrome/etiology , Mice , Mice, Inbred C57BL , Muscle, Skeletal/metabolism , Obesity/etiology , Random Allocation , Trehalose/administration & dosage
13.
Nutr Res ; 30(12): 840-8, 2010 Dec.
Article in English | MEDLINE | ID: mdl-21147367

ABSTRACT

Trehalose has been shown to evoke lower insulin secretion than glucose in oral saccharide tolerance tests in humans. Given this hypoinsulinemic effect of trehalose, we hypothesized that trehalose suppresses adipocyte hypertrophy by reducing storage of triglyceride and mitigates insulin resistance in mice fed a high-fat diet (HFD). Mice were fed an HFD and given drinking water containing 2.5% saccharide (glucose [Glc], trehalose [Tre], maltose [Mal], high-fructose corn syrup, or fructose [Fru]) ad libitum. After 7 weeks of HFD and saccharide intake, fasting serum insulin levels in the Tre/HFD group were significantly lower than in the Mal/HFD and Glc/HFD groups (P < .05). Furthermore, the Tre/HFD group showed a significantly suppressed elevation of homeostasis model assessment-insulin resistance compared with the Mal/HFD group (P < .05) and showed a trend toward lower homeostasis model assessment-insulin resistance than the Glc/HFD group. After 8 weeks of feeding, mesenteric adipocyte size in the Tre/HFD group showed significantly less hypertrophy than the Glc/HFD, Mal/HFD, high-fructose corn syrup/HFD, or Fru/HFD group. Analysis of gene expression in mesenteric adipocytes showed that no statistically significant difference in the expression of monocyte chemoattractant protein-1 (MCP-1) messenger RNA (mRNA) was observed between the Tre/HFD group and the distilled water/standard diet group, whereas a significant increase in the MCP-1 mRNA expression was observed in the Glc/HFD, Mal/HFD, Fru/HFD, and distilled water/HFD groups. Thus, our data indicate that trehalose prevents adipocyte hypertrophy and mitigates insulin resistance in HFD-fed mice by reducing insulin secretion and down-regulating mRNA expression of MCP-1. These findings further suggest that trehalose is a functional saccharide that mitigates insulin resistance.


Subject(s)
Adipocytes/drug effects , Chemokine CCL2/metabolism , Dietary Sucrose/administration & dosage , Insulin Resistance/physiology , Insulin/blood , Obesity/physiopathology , Trehalose/pharmacology , Adipocytes/pathology , Animals , Chemokine CCL2/genetics , Dietary Fats/adverse effects , Female , Gene Expression/drug effects , Hypertrophy , Mice , Mice, Inbred C57BL , Obesity/drug therapy , Obesity/metabolism , Obesity/pathology , RNA, Messenger/metabolism , Trehalose/therapeutic use
14.
Biol Pharm Bull ; 32(12): 2022-8, 2009 Dec.
Article in English | MEDLINE | ID: mdl-19952422

ABSTRACT

We examined the hypolipidemic effect of propolis in a mouse obesity model induced by a high fat-diet. C57BL/6N mice were fed a high-fat diet ad libitum and given propolis extract intragastrically at 0 mg/kg (control), 5 mg/kg or 50 mg/kg twice daily for 10 d. Compared with mice in the control group, mice in the propolis extract-administrated groups displayed a reduction in all of the following parameters: body weight gain, weight of visceral adipose tissue, liver and serum triglycerides, cholesterol, and non-esterified fatty acids. Real-time polymerase chain reaction analysis of the liver showed down-regulation of mRNA expression associated with fatty acid biosynthesis, including fatty acid synthase, acetyl-CoA carboxylase alpha, and sterol regulatory element binding protein in the propolis-administrated mice. Subsequently, obese C57BL/6N mice that had been administered a high-fat diet were given propolis extract at 0 mg/kg (control), 2.5 mg/kg or 25 mg/kg for 4 weeks. The propolis extract treated mice showed a decrease in weight gain, a reduction of serum non-esterified fatty acids, and lipid accumulation in the liver. These results suggest that propolis extract prevented and mitigated high-fat diet-induced hyperlipidemia by down-regulating the expression of genes associated with lipid metabolism.


Subject(s)
Apitherapy , Body Weight/drug effects , Dietary Fats/adverse effects , Hyperlipidemias/prevention & control , Obesity/drug therapy , Propolis/therapeutic use , Weight Gain/drug effects , Acetyl-CoA Carboxylase/genetics , Acetyl-CoA Carboxylase/metabolism , Animals , Diet/adverse effects , Dietary Fats/administration & dosage , Down-Regulation , Fatty Acid Synthases/genetics , Fatty Acid Synthases/metabolism , Hyperlipidemias/etiology , Hypolipidemic Agents/pharmacology , Hypolipidemic Agents/therapeutic use , Intra-Abdominal Fat/drug effects , Lipid Metabolism/drug effects , Lipid Metabolism/genetics , Liver/metabolism , Male , Mice , Mice, Inbred C57BL , Propolis/pharmacology , RNA, Messenger/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Sterol Regulatory Element Binding Proteins/genetics , Sterol Regulatory Element Binding Proteins/metabolism
15.
J Biol Chem ; 284(50): 34930-4, 2009 Dec 11.
Article in English | MEDLINE | ID: mdl-19826006

ABSTRACT

Nicotinic acid adenine dinucleotide phosphate (NAADP) is a Ca(2+)-releasing messenger. Biological data suggest that its receptor has two binding sites: one high-affinity locking site and one low-affinity opening site. To directly address the presence and function of these putative binding sites, we synthesized and tested analogues of the NAADP antagonist Ned-19. Ned-19 itself inhibits both NAADP-mediated Ca(2+) release and NAADP binding. A fluorometry bioassay was used to assess NAADP-mediated Ca(2+) release, whereas a radioreceptor assay was used to assess binding to the NAADP receptor (only at the high-affinity site). In Ned-20, the fluorine is para rather than ortho as in Ned-19. Ned-20 does not inhibit NAADP-mediated Ca(2+) release but inhibits NAADP binding. Conversely, Ned-19.4 (a methyl ester of Ned-19) inhibits NAADP-mediated Ca(2+) release but cannot inhibit NAADP binding. Furthermore, Ned-20 prevents the self-desensitization response characteristic of NAADP in sea urchin eggs, confirming that this response is mediated by a high-affinity allosteric site to which NAADP binds in the radioreceptor assay. Collectively, these data provide the first direct evidence for two binding sites (one high- and one low-affinity) on the NAADP receptor.


Subject(s)
Carbolines/metabolism , NADP/analogs & derivatives , Piperazines/metabolism , Receptors, Cell Surface/metabolism , Animals , Binding Sites , Biological Assay/methods , Calcium/metabolism , Carbolines/chemistry , Molecular Structure , NADP/antagonists & inhibitors , Oocytes/cytology , Oocytes/metabolism , Piperazines/chemistry , Radioligand Assay , Receptors, Cell Surface/genetics , Sea Urchins
16.
Biosci Biotechnol Biochem ; 73(3): 582-7, 2009 Mar 23.
Article in English | MEDLINE | ID: mdl-19270366

ABSTRACT

Lactosucrose (LS, 4(G)-beta-D-galactosylsucrose) is a non-digestible oligosaccharide, and the consumption of LS selectively increases the proportion of intestinal bifidobacteria. We examined in this study the hypolipidemic potential of LS. An oral triolein tolerance test on rats indicated that LS reduced the elevation of serum triglyceride (TG) and free fatty acids (FFA). Furthermore, LS inhibited the enzymatic digestion of triolein by pancreatic lipase in vitro. NMR spectroscopy showed that LS formed an intermolecular complex with triolein. The long-term consumption of a diet containing 5% LS for 8 weeks significantly decreased the weight of abdominal adipose tissue when compared with that of the control group. Thus, LS may reduce adipose tissue accumulation by inhibiting intestinal lipid absorption via a direct interaction with TG.


Subject(s)
Adipose Tissue/drug effects , Adipose Tissue/metabolism , Intestinal Absorption/drug effects , Lipid Metabolism/drug effects , Trisaccharides/pharmacology , Abdominal Fat/drug effects , Abdominal Fat/metabolism , Animals , Dietary Supplements , Fatty Acids, Nonesterified/blood , Lipase/metabolism , Male , Obesity/prevention & control , Pancreas/enzymology , Rats , Rats, Wistar , Time Factors , Triglycerides/blood , Triolein/metabolism , Trisaccharides/metabolism , Veins/drug effects , Veins/metabolism
17.
Nat Chem Biol ; 5(4): 220-6, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19234453

ABSTRACT

Research into the biological role of the Ca(2+)-releasing second messenger NAADP (nicotinic acid adenine dinucleotide phosphate) has been hampered by a lack of chemical probes. To find new chemical probes for exploring NAADP signaling, we turned to virtual screening, which can evaluate millions of molecules rapidly and inexpensively. We used NAADP as the query ligand to screen the chemical library ZINC for compounds with similar three-dimensional shape and electrostatic properties. We tested the top-ranking hits in a sea urchin egg bioassay and found that one hit, Ned-19, blocks NAADP signaling at nanomolar concentrations. In intact cells, Ned-19 blocked NAADP signaling and fluorescently labeled NAADP receptors. Moreover, we show the utility of Ned-19 as a chemical probe by using it to demonstrate that NAADP is a key causal link between glucose sensing and Ca(2+) increases in mouse pancreatic beta cells.


Subject(s)
NADP/analogs & derivatives , Animals , Carbolines/chemistry , Carbolines/pharmacology , Cyclic ADP-Ribose/pharmacology , Inositol 1,4,5-Trisphosphate/pharmacology , Insulin-Secreting Cells/drug effects , Mice , Models, Molecular , Molecular Structure , NADP/chemistry , NADP/metabolism , Ovum/chemistry , Piperazines/chemistry , Piperazines/pharmacology , Sea Urchins , Small Molecule Libraries
18.
Biosci Biotechnol Biochem ; 71(11): 2766-73, 2007 Nov.
Article in English | MEDLINE | ID: mdl-17986785

ABSTRACT

In this study, we examined the effects of dietary lactosucrose (LS, a non-digestible oligosaccharide) on the IgE response in mice immunized with ovalbumin (OVA)/alum. In addition to IgG1 and IgG2a responses, the anti-OVA IgE response in mice fed LS diets was dose-dependently suppressed, as compared with the control mice, while the serum total IgG levels were comparable. Moreover, dietary LS feeding inhibited antigen-specific IgE and IgG1 productions even after a second immunization. Regarding with cytokine production, when stimulated in vitro with OVA, splenocytes obtained from LS-fed mice produced a similar level of IFN-gamma, and lower levels of IL-4 and IL-5, as compared with the control mice. But IL-10 production by OVA-stimulated splenocytes was augmented in LS-fed mice, suggesting that IL-10 producing cells are responsible for the immunoregulatory effect of LS. Our findings indicate the further possibility that dietary LS supplementation can be used to prevent IgE-mediated allergic diseases.


Subject(s)
Dietary Carbohydrates/administration & dosage , Hypersensitivity/prevention & control , Immunoglobulin E/biosynthesis , Immunosuppression Therapy , Trisaccharides/administration & dosage , Adjuvants, Immunologic/administration & dosage , Allergens/immunology , Alum Compounds/administration & dosage , Animals , Antibody Formation/drug effects , Cytokines/metabolism , Hypersensitivity/immunology , Immunization , Immunoglobulin E/blood , Immunoglobulin G/biosynthesis , Immunoglobulin G/blood , Mice , Ovalbumin/immunology , Spleen/drug effects , Spleen/immunology
19.
Biol Pharm Bull ; 29(5): 896-902, 2006 May.
Article in English | MEDLINE | ID: mdl-16651715

ABSTRACT

AgK114 is a newly isolated membrane-associated protein which is expressed on keratinocytes. Its expression is restricted to dermal sheath cells near sebaceous glands in normal skin. However, it is transiently induced by UV exposure or injury stimulation (Tatefuji T. et al., Biol. Pharm. Bull., 27, 1742-1749, 2004). Thus, the expression pattern of AgK114 suggested its potential role in wound healing response. We report here that expression of AgK114 is induced in the initial 24 h at the edge keratinocytes during keratinocyte migration, followed by disappearance once epithelialization is completed in the murine excisional wound model. We also demonstrate that exogenous recombinant mouse AgK114FL promoted wound healing process. Mouse AgK114FL up-regulated pro-matrix-metalloproteinase-9, vascular endothelial growth factor, transforming growth factor-beta, IL-6, and IL-1beta production in the early stage of wound tissue. Moreover, mouse AgK114FL induced the matrix-metalloproteinase-9 activity of wound fibroblasts prepared from impaired skin in the presence of proinflammatory cytokines. These results suggest that the AgK114 participates in the wound response during the healing process, and promotes wound repair.


Subject(s)
Cytokines/biosynthesis , Membrane Glycoproteins/pharmacology , Wound Healing/drug effects , Amino Acid Sequence , Animals , Antibodies, Monoclonal/pharmacology , Blotting, Western , CHO Cells , Cells, Cultured , Cricetinae , Fibroblasts/drug effects , Fibroblasts/enzymology , Immunohistochemistry , In Vitro Techniques , Matrix Metalloproteinase 9/biosynthesis , Mice , Molecular Sequence Data , Recombinant Fusion Proteins/biosynthesis , Skin/injuries , Skin/pathology
20.
In Vivo ; 20(3): 347-51, 2006.
Article in English | MEDLINE | ID: mdl-16724668

ABSTRACT

BACKGROUND: Mouse AgK114 (a glycosylphosphatidylinositol (GPI) anchored membrane-associated protein) expression is found in somatotrophs of the pituitary gland in correlation with the expression of growth hormone. In this study, the effects of AgK114 on the systemic immune response were examined in contact hypersensitivity (CHS) model mice. MATERIALS AND METHODS: AgK114 was intraperitoneally injected into BALB/c mice that were sensitized and challenged with picryl chloride (PiCl). Serum IgE levels and the antigen-specific cytokine production by lymph node (LN) cells were examined. RESULTS: The serum IgE levels in the CHS mice treated with 10 microg/head of AgK114 during the repeated challenge with PiCl were significantly decreased compared with those of the control mice. Moreover, IL-4 production by LN cells in response to 2,4,6-trinitrobenzene-sulfonic acid sodium salt-treated splenocytes was decreased in the AgK114-treated CHS mice compared with that of the control mice. CONCLUSION: Our results suggest that systemic administration of AgK114 exerted immunoregulatory functions on the allergic responses, resulting in the inhibition of IgE production.


Subject(s)
Dermatitis, Allergic Contact/drug therapy , Dermatitis, Allergic Contact/immunology , Glycosylphosphatidylinositols/pharmacology , Picryl Chloride/toxicity , Animals , Antibodies, Monoclonal/metabolism , Chronic Disease , Dermatitis, Allergic Contact/etiology , Dermatitis, Allergic Contact/pathology , Disease Models, Animal , Female , Glycosylphosphatidylinositols/administration & dosage , Glycosylphosphatidylinositols/genetics , Immunoglobulin E/blood , Injections, Intraperitoneal , Injections, Intravenous , Interferon-gamma/analysis , Interleukin-10/analysis , Interleukin-4/analysis , Male , Mice , Mice, Inbred BALB C , Mice, Inbred Strains , Recombinant Proteins/pharmacology , Spleen/cytology , Spleen/drug effects , Trinitrobenzenesulfonic Acid/analogs & derivatives , Trinitrobenzenesulfonic Acid/pharmacology
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