Intestinal inflammation induced by dextran sodium sulphate causes liver inflammation and lipid metabolism disfunction in laying hens.

Gut inflammation caused by various factors including microbial infection leads to disorder of absorption of dietary nutrients and decrease in egg production in laying hens. We hypothesized that intestinal inflammation may affect egg production in laying hens through its impact on liver function. Dextran sodium sulphate (DSS) is known to induce intestinal inflammation in mammals, but whether it also induces inflammation in laying hens is not known. The goal of this study was to assess whether oral administration of DSS is a useful model of intestinal inflammation in laying hens and to characterize the effects of intestinal inflammation on egg production using this model. White Leghorn hens (350-day old) were administrated with or without 0.9 g of DSS/kg BW in drinking water for 5 D (n = 8, each). All laid eggs were collected, and their whole and eggshell weights were recorded. Blood was collected every day and used for biochemical analysis. Liver and intestinal tissues (duodenum, jejunum, ileum, cecum, cecal-tonsil, and colon) were collected 1 D after the final treatment. These tissue samples were used for histological analysis and PCR analysis. Oral administration of DSS in laying hens caused 1) histological disintegration of the cecal mucosal epithelium and increased monocyte/macrophage infiltration and IL-1ß, IL-6, CXCLi2, IL-10, and TGFß-4 gene expression; 2) decreased egg production; 3) increased leukocyte infiltration and IL-1ß, CXCLi2, and IL-10 expression in association with a high frequency of lipopolysaccharide-positive cells in the liver; and 4) decreased expression of genes related to lipid synthesis, lipoprotein uptake, and yolk precursor production. These results suggested that oral administration of DSS is a useful method for inducing intestinal inflammation in laying hens, and intestinal inflammation may reduce egg production by disrupting egg yolk precursor production in association with liver inflammation.

Effects of in ovo feeding of L-leucine on amino acids metabolism and heat-shock protein-70, and -90 mRNA expression in heat-exposed chicks.

Recently, we found that in ovo feeding of L-leucine (L-Leu) stimulated the metabolism of lipids and afforded thermotolerance in male Chunky broiler chicks. In this study, we investigated the effects of feeding L-Leu in ovo on the metabolism of amino acids and on the cellular stress response mainly in the central and peripheral tissues in neonatal male broiler chicks and partly in embryonic tissues. Chicks (9 d old) were exposed to high ambient temperature (HT: 35 ± 1°C) or control thermoneutral temperature (CT: 28 ± 1°C) for 180 min. The ambient temperatures were based on our recent reports and the recommendation of the Chunky broiler manual in which 28°C has been suggested as a normal ambient temperature for 5 to 9-d-old broiler chicks. In ovo feeding of L-Leu caused a significant (P < 0.05) decline in diencephalic arginine concentrations but it increased the diencephalic and plasma lysine concentrations when compared with the control chicks under HT. Notably, in ovo feeding of L-Leu significantly (P < 0.05) attenuated the increment of hepatic arginine compared with the control chicks under HT. Interestingly, in ovo feeding of L-Leu significantly (P < 0.05) attenuated the diencephalic gene expression of heat-shock protein (HSP) -70 and -90 in heat-exposed chicks. The gene expressions of mammalian target of rapamycin (mTOR) and its downstream genes (ribosomal protein S6 kinase (S6K1) and eukaryotic initiation factor 4E binding protein 1 (4E-BP1)) in the central and peripheral tissues were not influenced in the chicks under heat stress. We found that the gene expressions of mTOR, S6K1, and 4E-BP1 were significantly (P < 0.05) stimulated only in the embryonic breast muscle, and not in the other embryonic tissues, by in ovo feeding of L-Leu. In conclusion, in ovo feeding of L-Leu caused a change in the metabolism of amino acids in response to heat stress in broiler chicks. Attenuated gene expressions of HSP-70 and -90 under heat stress further suggests that in ovo feeding of L-Leu may afford thermotolerance in broilers.

Intracerebroventricular administration of GABA-A and GABA-B receptor antagonists attenuate feeding and sleeping-like behavior induced by L-pipecolic acid in neonatal chicks.

It has been demonstrated that L-pipecolic acid (L-PA), a major metabolic intermediate of L-lysine (L-Lys) in the mammalian and chicken brain, is involved in the functioning of the GABAergic system. A previous study has shown that intracerebroventricular (i.c.v.) injection of L-PA suppressed feeding and induced sleep-like behavior in neonatal chicks; however, the precise relationship between the GABAergic system and L-PA has not been clarified. In the present study, the role of the GABA-A or GABA-B receptors in the suppression of food intake and induction of sleeping-like behavior by L-PA was investigated. Chicks were injected i.c.v. with the GABA-A antagonist picrotoxin or GABA-B antagonist CGP54626 along with L-PA. Although suppression of food intake by L-PA was restored partially by co-injection with CGP54626, but not picrotoxin, sleep-like behavior induced by L-PA was suppressed significantly by both antagonists. These results suggested that L-PA activated both GABA-A and GABA-B receptors, and GABA-B receptors alone contributed to food intake whereas both receptors contributed to sleep-like behavior.

Intracerebroventricular injection of fusaric acid attenuates the anorexia by glucagon-like peptide-1 in the neonatal chick.

It is known that central injection of glucagon-like peptide-1 (GLP-1) suppresses feeding in rats and chicks, but the systems for GLP-1 are still open with special reference to the chick. The present study was done to determine whether a noradrenergic mechanism contributes to the anorexigenic effect of GLP-1 on the neonatal chick. Central administration of norepinephrine (NE) suppressed food intake with narcolepsy as GLP-1 in chicks. However, in spite of that dopamine (DA) did not affect food intake, coadministration of inhibitor of dopamine-beta-hydroxylase (DBH), fusaric acid (FA), attenuated the suppressive effect of GLP-1 on feeding behavior. It is suggested that there may be the interactive relationships between GLP-1 and noradrenergic system in the neonatal chick.

Crystals of ternary protein-DNA complexes composed of DNA-binding domains of c-Myb or v-Myb, C/EBPalpha or C/EBPbeta and tom-1A promoter fragment.

c-Myb and the C/EBP family are transcriptional regulatory factors that act in concert to regulate the expression of myeloid-specific genes. v-Myb encoded by avian myeloblastosis virus (AMV) is a mutated form of c-Myb that contains point mutations which disrupt the cooperation with C/EBPs. To understand the mechanism of the transcriptional synergy between c-Myb and C/EBPs and the effect of the v-Myb mutations on that synergy, knowledge based on their three-dimensional structures is essential. Crystals of ternary complexes, in which various combinations of the DNA-binding domains of c-Myb or v-Myb and C/EBPalpha or C/EBPbeta are bound to a DNA fragment from tom-1A promoter, were obtained by the vapour-diffusion method. Complete diffraction data sets were obtained from each native crystal and two types of iodine-derivative crystals. A three-wavelength MAD data set was also obtained from a bromine-derivative crystal.

Intracerebroventricular injection of pipecolic acid inhibits food intake and induces sleeping-like behaviors in the neonatal chick.

It has been demonstrated that L-pipecolic acid (L-PA), a major metabolic intermediate of L-Lysine (L-Lys) in the brain, is involved in the functioning of Gamma-aminobutyric acid. In the present work the effect of intracerebroventricular (i.c.v.) administration of L-PA, and its relatives, on food intake and behavior in neonatal chicks was investigated. The i.c.v. injection of 1 mg of L-PA and D-PA significantly inhibited food intake during the 2 h following injection, whereas greater than 2 mg of L-Lys was required to inhibit food intake. In behavioral tests, the i.c.v. injection of L-PA reduced active wakefulness and feeding behavior while inducing sleeping-like behavior in chicks. These results suggest that L-PA has an important role for the regulation of behaviors in the neonatal chick after conversion from L-Lys in the brain.

Feeding responses to several neuropeptide Y receptor agonists in the neonatal chick.

Neuropeptide Y is one of the most potent neuropeptides known to induce feeding in animals, and has been suggested to be a physiological signal for food intake. It has been also reported that intracerebroventricular injection of neuropeptide Y stimulates feeding behavior of the neonatal chick. There are many neuropeptide Y receptor agonists that have not been investigated in feeding response of the neonatal chick. The aim of this study is to elucidate whether central injection of several neuropeptide Y receptor agonists stimulates feeding of the neonatal chick over 2 h. We found that central injections of [Leu(31), Pro(34)]neuropeptide Y, peptide YY, human pancreatic polypeptide and rat pancreatic polypeptide significantly stimulated food intake of neonatal chicks throughout the 2-h post-injection period. Neuropeptide Y-(13-36) significantly stimulated feeding at 30 min, but not thereafter. [D-Trp(32)]neuropeptide Y stimulated feeding at 60 and 120 min, but not 30 min, post-injection. Central administration of rat pancreatic polypeptide, which does not increase food intake in rats, stimulated feeding in chicks. This result reflects structural differences of the neuropeptide Y receptor subtypes and/or differences in mechanisms stimulating feeding behavior between mammals and chickens. In conclusion, neuropeptide Y receptor agonists, except for neuropeptide Y-(13-36), are potent stimulators of food intake in the neonatal chick.

Crystallization and preliminary X-ray analyses of quaternary, ternary and binary protein-DNA complexes with involvement of AML1/Runx-1/CBFalpha Runt domain, CBFbeta and the C/EBPbeta bZip region.

Three types of protein-DNA complexes, AML1/Runx-1/CBFalpha(Runt)-CBFbeta-C/EBPbeta(bZip)-DNA (CBFalpha-beta-C/EBPbeta-DNA), AML1/Runx-1/CBFalpha(Runt)-C/EBPbeta(bZip)-DNA (CBFalpha-C/EBPbeta-DNA) and AML1/Runx-1/CBFalpha(Runt)-DNA (CBFalpha-DNA), were crystallized. The crystals were all orthorhombic and belonged to space groups C222(1), P2(1)2(1)2 and P2(1)2(1)2(1), respectively. The resolutions of CBFalpha-beta-C/EBPbeta-DNA and CBFalpha-C/EBPbeta-DNA crystals were both 3 A, while that of the CBFalpha-DNA crystal was 2.65 A. Complete data sets were collected for all of the native crystals, along with MAD and MIR data sets for CBFalpha-beta-C/EBPbeta-DNA. The heavy-atom site was determined using MAD data for a gold derivative of CBFalpha-beta-C/EBPbeta-DNA.

Crystallization and preliminary X-ray analysis of the C/EBPbeta C-terminal region in complex with DNA.

The C-terminal fragment (residues 259-345) of human C/EBPbeta, a basic region leucine zipper transcriptional regulatory factor which includes the minimal DNA-binding domain, was crystallized in complex with a 16 bp DNA fragment from the tom-1 promoter. The crystals were in the form of a parallelepiped belonging to space group C222(1), had unit-cell parameters a = 100.7 (2), b = 113.5 (1), c = 74.4 (1) A and diffracted to a resolution of 2.1 A. Moreover, truncation of nine residues from the C-terminus not conserved among C/EBP family members yielded isomorphous crystals that diffracted to a resolution of 1.8 A or better. Truncation of 14 residues from the N-terminus of the C-terminal fragment produced well shaped crystals in the form of hexagonal bipyramids, however; unfortunately, they were unstable and diffracted poorly.

Structural analyses of DNA recognition by the AML1/Runx-1 Runt domain and its allosteric control by CBFbeta.

The core binding factor (CBF) heterodimeric transcription factors comprised of AML/CBFA/PEBP2alpha/Runx and CBFbeta/PEBP2beta subunits are essential for differentiation of hematopoietic and bone cells, and their mutation is intimately related to the development of acute leukemias and cleidocranial dysplasia. Here, we present the crystal structures of the AML1/Runx-1/CBFalpha(Runt domain)-CBFbeta(core domain)-C/EBPbeta(bZip)-DNA, AML1/Runx-1/CBFalpha(Runt domain)-C/EBPbeta(bZip)-DNA, and AML1/Runx-1/CBFalpha(Runt domain)-DNA complexes. The hydrogen bonding network formed among CBFalpha(Runt domain) and CBFbeta, and CBFalpha(Runt domain) and DNA revealed the allosteric regulation mechanism of CBFalpha(Runt domain)-DNA binding by CBFbeta. The point mutations of CBFalpha related to the aforementioned diseases were also mapped and their effect on DNA binding is discussed.

Relationships between feeding and locomotion behaviors after central administration of CRF in chicks.

The effect of intracerebroventricular injection of corticotropin-releasing factor (CRF) on various behaviors in chicks was determined at 15-min intervals over a 30-min period. Food intake of chicks was significantly decreased, and pecking rhythm was significantly delayed by CRF during the first 15-min post-injection. The similar tendencies were observed in the second 15-min post-injection, but not significantly different. Stepping, as an indicator of locomotion, was not different at 15-min post-injection, but was increased by CRF, thereafter. These results suggest that CRF acts within the central nervous system to decrease food intake and increase locomotion in the chick.

Intracerebroventricular injection of mammalian motilin, melanin-concentrating hormone or galanin does not stimulate food intake in neonatal chicks.

1. Several neural peptides are known to stimulate feeding behaviour in mammalian species. The aim of this study was to elucidate whether central injection of mammalian motilin, melanin-concentrating hormone (MCH) or galanin stimulates feeding in the neonatal chick. 2. None of the peptides applied here enhanced the food intake of the chick. 3. It is suggested that motilin, MCH and galanin, at least those of mammalian origin, may not regulate feeding in neonatal chicks, when administered to the central nervous system.

Central bombesin inhibits food intake and the orexigenic effect of neuropeptide Y in the neonatal chick.

It is well known that central injection of bombesin (BN) suppresses feeding in mammalian and avian species, but the anorexigenic effect of central BN are still open with special reference to the chick. The dose response (0, 0.1 and 0.5 microg) of intracerebroventricular (ICV) injection of BN was examined in Experiment 1. ICV injection of BN inhibited food intake in a dose-dependent manner. Experiment 2 was done to determine whether BN interacts with the orexigenic effect of neuropeptide Y (NPY) in the neonatal chick. Central administration of NPY (2.5 microg) greatly enhanced food intake, but co-injection of BN (0.5 microg) suppressed food intake. The dose response of NPY (2.5 microg) co-injected with three levels of BN (0, 0.1 and 0.5 microg) was examined in Experiment 3. ICV injection of BN attenuated the hyperphagia by NPY in a dose-related fashion. It is suggested that central BN may interact with NPY for the regulation of feeding in the neonatal chick.

Central administration of alpha-melanocyte stimulating hormone inhibits fasting- and neuropeptide Y-induced feeding in neonatal chicks.

In the present study, the effect of intracerebroventricular (i.c.v.) administration of alpha-melanocyte stimulating hormone (alpha-MSH) on food intake of neonatal chicks was examined. In experiment 1, i.c. v. injection of alpha-MSH (0.04, 0.2 and 1 microg) significantly inhibited food intake of 3-h fasted chicks in a dose-dependent manner. In experiment 2, alpha-MSH strongly inhibited neuropeptide Y-induced feeding when neuropeptide Y (2.5 microg) and several doses of alpha-MSH were given simultaneously i.c.v. These results suggest that alpha-MSH plays an important role in the regulation of food intake of neonatal chicks.

Brain-derived mast cells could mediate histamine-induced inhibition of food intake in neonatal chicks.

In the present study, the effect of intracerebroventricular (i.c.v.) administration of histamine on food intake of neonatal chicks was examined over 2 h. Histamine (100, 200 or 400 nmol, respectively) was injected in the lateral ventricle of 2-day-old chicks, and cumulative food intakes were measured. i.c.v. injection of histamine significantly inhibited food intake in a dose-dependent manner. In addition, compound 48/80, which causes degranulation of mast cells and release of histamine, or thioperamide, which is an antagonist of the histamine H3 autoreceptor and increases histamine release from histaminergic nerve terminals, was injected i.c.v. to clarify whether mast cell- or neuron-derived histamine in the central nervous system of chicks is essential to the feeding inhibition. Central administration of compound 48/80 inhibited food intake with a dose-dependent manner, but thioperamide had no effect on feeding. An inhibitor of mast cell degranulation, sodium cromoglycate, somewhat attenuated food intake inhibited by compound 48/80. These results suggest that brain-derived mast cells could be a major source of histamine in the inhibition of food intake of neonatal chicks.

Central gastrin inhibits feeding behavior and food passage in neonatal chicks.

The gastrin/cholecystokinin (CCK) family is recognized as the principal family of hormones involved in regulation of the gastrointestinal tract CCK is recognized as a satiety hormone in mammalian species, but it has been suggested that gastrin rather CCK may have an important role in controlling feeding behavior in the neonatal chick through a poorly developed blood brain barrier. So far, however, there is no direct evidence that central gastrin inhibits food intake in neonatal chicks. The aim of this study was to elucidate whether central administration of gastrin 1) inhibits feeding behavior and 2) alters food passage from the crop. The effects of central administration of gastrin on food intake were investigated in experiment 1. Birds (2-day-old) were food-deprived for 3 h and then gastrin or saline was injected intracerebroventricularly. Gastrin strongly inhibited food intake in a dose-dependent fashion for 2 h. Thereafter, the effects of central gastrin on feeding behavior and serum corticosterone concentration were examined in experiment 2. Following central administration of gastrin, food intake was depressed and pecking behavior was inhibited. Serum corticosterone concentration was not altered by central administration of gastrin. The influence of central gastrin on food passage from the crop was investigated in experiment 3. Central administration of gastrin clearly delayed food passage. In conclusion, central gastrin appears to have a strong effect for the satiety and gastrointestinal motility in the neonatal chick.

Induction of food intake by a noradrenergic system using clonidine and fusaric acid in the neonatal chick.

To clarify noradrenergic systems on food intake of the neonatal chicks, we examined the effects of i.c.v injection of clonidine (CLON), an alpha2-receptor agonist, and fusaric (5-butylpicolinic) acid (FA), a dopamine (DA)-beta-hydroxylase (DBH) inhibitor. Although a high dose (250 ng) of CLON induced a narcoleptic response and reduced food intake, food intake at 30 min post-injection was enhanced by lower doses (25 and 50 ng) of CLON. Central administration of FA (25, 50 and 100 microg) increased food intake in a dose-dependent fashion. It is suggested that feeding behavior is stimulated by low levels of CLON and decreased by further production of norepinephrine (NE), and FA may play the disturbance of sleeping and then enhance food intake.

Intracerebroventricular administration of mouse leptin does not reduce food intake in the chicken.

Recently, it has been suggested that leptin plays an important role in regulation of food intake and metabolism in rats and mice, however, the effect of central administration of leptin on food intake in chicks has not been reported. We have investigated the anorexigenic effect of leptin administered by intracerebroventricular (i.c.v.) injection in chicks using mouse leptin, which shows 97% homology to chicken leptin. Three experiments were conducted. After being deprived of food for 3 h, male broiler chicks were administered leptin by i.c.v. injection at dose levels of 0, 0.2, 1.0 and 5.0 microg (Experiment 1) or 0, 2.5 and 5.0 microg (Experiment 2). The birds were allowed free access to the diet for 2 h (Experiment 1) and 24 h (Experiment 2) after treatment. Male Single Comb White Leghorn chicks were used in Experiment 3 and were treated in the same manner as in Experiment 1. In all experiments, central administration of mouse leptin did not influence food intake in the time periods examined. It appears that either mouse leptin does not bind to the chicken leptin receptor or in the chicken brain the leptin receptor may be absent.

Effects of substitution of N-terminal amino acid of glucagon-like peptide-1 (7-36) amide on food intake of the neonatal chick.

Glucagon-like peptide-1 (GLP-1), a member of glucagon superfamily, is synthesized from a large precursor, preproglucagon, and has been postulated to be a novel incretin. Recently, it was reported that central administration of GLP-1 (7-36) amide decreased food intake in rats and chickens. Generally, the amino acid sequences of the glucagon superfamily members except for gastric inhibitory peptide and growth hormone-releasing factor are identical at N-terminal histidine. It is well known that the GLP-1 receptor is highly specific for GLP-1 and does not bind other peptides of the glucagon superfamily. The aim of this study was to elucidate whether central injection of substituted GLP-1 in which N-terminal histidine of mammalian GLP-1 (7-36) amide was replaced with tyrosine, inhibits food intake in the chick. Intracerebroventricular administration of substituted GLP-1 inhibits food intake in the chick, although the effect of substituted GLP-1 was 11 to 13 fold less than that of mammalian GLP-1 (7-36) amide. These results indicate that N-terminal histidine of GLP-1 (7-36) amide is important for efficacy, but not essential for its bioactivity.

Intracerebroventricular injection of orexins does not stimulate food intake in neonatal chicks.

1. Recently, 2 novel neuropeptides were discovered, both derived from the same precursor by proteolytic processing, which bind and activate 2 closely related orphan G protein-coupled receptors, Named orexin-A and -B (Sakurai et al., 1998). Both stimulate food intake when administered centrally to rats. 2. Our aim was to elucidate whether central injection of mammalian orexin-A or -B stimulates food intake in the chick. 3. Under conditions of free access to food, orexin-A did not alter the food intake of chicks, but cumulative food intake was significantly suppressed by orexin-B. 4. The orexin-B was then administered to chicks deprived of food for 3 h to confirm its suppressive effect. No significant effect of orexin-B on food intake was detected. 5. Central injection of orexin-B did not modify food intake when appetite was stimulated by fasting. 6. Neither of these orexins appears to stimulate feeding in chicks.