Influencing the endocrine metabolic regulation of chickens by nutritional factors might provide n... more Influencing the endocrine metabolic regulation of chickens by nutritional factors might provide novel possibilities for improving animal health and productivity. This study was designed to evaluate the impact of dietary cereal type (wheat-based (WB) vs. maize-based (MB) diets), crude protein level (normal (NP) vs. lowered (LP)), and sodium (n-)butyrate (1.5 g/kg diet) supplementation (vs. no butyrate) on the responsiveness of hepatic glucagon receptor (GCGR), insulin receptor beta (IRβ) and mammalian target of rapamycin (mTOR) in the phase of intensive growth of chickens. Liver samples of Ross 308 broiler chickens (Gallus gallus domesticus) were collected on day 21 for quantitative real-time polymerase chain reaction and Western blot analyses. Hepatic GCGR and mTOR gene expressions were up-regulated by WB and LP diet. GCGR and IRβ protein level decreased in groups with butyrate supplementation; however, the quantity of IRβ and mTOR protein increased in WB groups. Based on these data...
Effects of orally applied butyrate bolus on histone me P450 enzyme activity Conclusion: Orally ad... more Effects of orally applied butyrate bolus on histone me P450 enzyme activity Conclusion: Orally added butyrate in bolus could cause in vivo hyperacetylation of the hepatic core histones, Mátis et al. Nutrition & Metabolism 2013, 10:12
Dairy cows mobilize large amounts of body fat during early lactation to overcome negative energy ... more Dairy cows mobilize large amounts of body fat during early lactation to overcome negative energy balance which typically arises in this period. As an adaptation process, adipose tis-sues of cows undergo extensive remodeling during late pregnancy and early lactation. The objective of the present study was to characterize this remodeling to get a better under-standing of adaptation processes in adipose tissues, affected by changing metabolic condi-tions including lipid mobilization and refilling as a function of energy status. This was done by determining adipocyte size in histological sections of subcutaneous and retroperitoneal adipose tissue biopsy samples collected from German Holstein cows at 42 days prepartum, and 1, 21, and 100 days postpartum. Characterization of cell size changes was extended by the analysis of DNA, triacylglycerol, and protein content per gram tissue, and β-actin pro-tein expression in the same samples. In both adipose tissue depots cell size was becoming sm...
Orally applied butyrate as a nutritional supplement has a huge impact on the health of the gastro... more Orally applied butyrate as a nutritional supplement has a huge impact on the health of the gastrointestinal epithelium and the gut microflora. In addition, as an epigenetically active molecule, it can also influence the expression of certain genes. Regarding the results of some in vitro studies, butyrate, absorbed from the intestines and taken to the liver by the portal circulation, may alter the action of hepatic microsomal cytochrome P450 (CYP) enzymes, involved in the biotransformation of xenobiotics, having a remarkable importance in food safety, as well. The authors aimed to study the possible effects of orally applied butyrate on hepatic CYP activity in rats after weaning, also serving as a monogastric mammalian model. Animals were fed with normal pelleted stock diet without or with sodium butyrate (1.5 g/kg diet) for 21 days. As a positive control, a group of rats was treated with intraperitoneal phenobarbital injection. Animals were euthanized on day 21, microsomal fractions were separated from the exsanguinated livers by differential centrifugation. The activity of the most important (VP subfamilies was screened by specific enzyme assays (aminopyrine N-demethylation: CYP2B/3A, testosterone 6 beta-hydroxylation: CYP3A). According to the results, butyrate as a feed supplement did not cause any changes in the drug-metabolising activity of the examined hepatic microsomal CYP enzymes. However, phenobarbital significantly (P<0,05) increased the microsomal CYP2B and CYP3A activity of the liver. These data indicate that the supplementation of the diet with butyrate probably may not have any pharmacokinetic interactions with simultaneously applied xenobiotics in monogastric mammals, so it can be applied safely as a nutritional supplement.
BEVEZETÉS A természeti területek városokká alakítása világszerte gyorsuló ütemben zajlik, e termé... more BEVEZETÉS A természeti területek városokká alakítása világszerte gyorsuló ütemben zajlik, e természetvédelmi szempontból is fontos folyamat egyedi és populáció szintű ökológiai hatásait azonban kevéssé ismerjük. A projektben annak vizsgálatát tűztük ki célul, hogy (i) az élőhelyek urbanizációjával miként változik két alapvető populáció-szabályozó tényező, a táplálékkompetíció és a predációs nyomás intenzitása, (ii) hogyan befolyásolja az urbanizáció a madarak viselkedését, stresszélettanát, egészségi állapotát és szaporodási sikerét, és hogy (iii) a városi és vidéki populációk morfológiai és reprodukciós különbségei környezeti hatásoknak vagy a városi életmódhoz való alkalmazkodás evolúciós következményének tudhatók-e be. A fenti kérdések megválaszolásához viselkedési, élettani és szaporodásbiológiai vizsgálatokat végeztünk szabadon élő és fogságban tartott házi verebeken, amelyek az urbanizációs gradiens különböző pontjairól származtak (vidéki, szuburbán, és városi területekről). Az eredetileg tervezett vizsgálatokat a következő módosításokkal végeztük el. A predációs nyomás és a táplálékkompetíció kísérletes terepi vizsgálatát (Munkaterv 1-2. kísérlet) a tervezett két év helyett egy évben végeztük, mivel a vizsgálatot végző PhD hallgató 2009-ben kilépett a PhD képzésből és a projektből, és tervezett feladatainak befejezésére nem volt módunk. Ehelyett egyrészt egy nem tervezett kísérletet végeztünk, amelyben laboratóriumi körülmények között hasonlítottuk össze a városi és vidéki egyedek predációs kockázatvállalását (Eredmények 1.2. pontja). Másrészt a táplálék-ellátottság és kompetíció vizsgálatához az 1. megfigyelést a tervezettnél nagyobb részletességgel végeztük (1.3. pont). A munkatervhez képest szintén jelentős kiegészítés, hogy két éven keresztül vizsgáltuk vadon élő madarak szaporodási sikerét különböző mértékben urbanizált élőhelyeken (1.5. pont), és a tervezett "common garden" kísérlet mellett egy fiókacserés kísérletet is elvégeztünk a környezeti és genetikai hatások fontosságának összehasonlítására (1.6. pont). A módosítások miatt az eredmények publikálásának gyorsasága elmaradt a tervezettől,
How urbanization aff ects animal populations is in the focus of current ecological research. Exis... more How urbanization aff ects animal populations is in the focus of current ecological research. Existing theory of this topic suggests that the cities' more constant food supplies and lower predation pressure lead to a high proportion of weak competitors in urban populations. To evaluate this hypothesis, we tested whether competitive performance diff ers between diff erently urbanized populations of house sparrows Passer domesticus. We previously showed that wild urban sparrows are smaller and leaner than rural conspecifi cs, and this diff erence persists for months under identical captive conditions. Here we compared several aspects of their competitiveness (fi ghting, scrambling and searching for food) in captive mixed fl ocks of urban and rural birds. We found that sparrows exhibited consistent individual diff erences in competitiveness, but these diff erences were not related either to the degree of urbanization of their original habitats or to their body mass. Moreover, the variance in competitive abilities also did not diff er between birds from more and less urbanized habitats. Th us our results did not support the hypothesis that urbanization shifts population structure towards an overabundance of weak competitors in house sparrows. We discuss possible explanations why sparrow populations may not diff er in competitiveness despite the smaller body mass of urban birds.
Background Butyrate is known as histone deacetylase inhibitor, inducing histone hyperacetylation ... more Background Butyrate is known as histone deacetylase inhibitor, inducing histone hyperacetylation in vitro and playing a predominant role in the epigenetic regulation of gene expression and cell function. We hypothesized that butyrate, endogenously produced by intestinal microbial fermentation or applied as a nutritional supplement, might cause similar in vivo modifications in the chromatin structure of the hepatocytes, influencing the expression of certain genes and therefore modifying the activity of hepatic microsomal drug-metabolizing cytochrome P450 (CYP) enzymes. Methods An animal study was carried out in chicken as a model to investigate the molecular mechanisms of butyrate’s epigenetic actions in the liver. Broiler chicks in the early post-hatch period were treated once daily with orally administered bolus of butyrate following overnight starvation with two different doses (0.25 or 1.25 g/kg body weight per day) for five days. After slaughtering, cell nucleus and microsomal f...
Social behaviour of group-living animals is often influenced by the relatedness of individuals, t... more Social behaviour of group-living animals is often influenced by the relatedness of individuals, thus understanding the genetic structure of groups is important for the interpretation of costs and benefits of social interactions. In this study, we investigated genetic relatedness in feeding aggregations of free-living house sparrows (Passer domesticus) during the nonbreeding season. This species is a frequent model system for studies of social behaviour (e.g. aggression, social foraging), but we lack adequate information on the kin structure of sparrow flocks. During two winters, we ringed and observed sparrows at feeding stations, and used resightings to identify stable flockmembers and to calculate association indices between birds. We genotyped the birds using seven highly polymorphic microsatellite loci, and estimated pairwise relatedness coefficients and relatedness categories (close kin vs. unrelated) by maximum likelihood method. We found that most birds were unrelated to each other in the flocks (mean ± SE relatedness coefficient: 0.06 ± 0.002), although most individuals had at least a few close relatives in their home flock (14.3 ± 0.6% of flock-mates). Pairwise association between individuals was not significantly related to their genetic relatedness. Furthermore, there was no difference between within-flock vs. between-flock relatedness, and birds had similar proportions of close kin within and outside their home flock. Finally, relatedness among members of different flocks was unrelated to the distance between their flocks. Thus, sparrow flocks were not characterized by association of relatives, nevertheless the presence of some close kin may provide opportunity for kin-biased behaviours to evolve.
Journal of Veterinary Pharmacology and Therapeutics, 2014
Butyrate, a commonly applied feed additive in poultry nutrition, can modify the expression of cer... more Butyrate, a commonly applied feed additive in poultry nutrition, can modify the expression of certain genes, including those encoding cytochrome P450 (CYP) enzymes. In comparative in vitro and in vivo experiments, the effect of butyrate on hepatic CYP genes was examined in primary cultures of chicken hepatocytes and in liver samples of chickens collected from animals that had been given butyrate as a feed additive. Moreover, the effect of butyrate on the biotransformation of erythromycin, a marker substance for the activity of enzymes of the CYP3A family, was investigated in vitro and in vivo. Butyrate increased the expression of the avian-specific CYP2H1 both in vitro and in vivo. In contrast, the avian CYP3A37 expression was decreased in hepatocytes following butyrate exposure, but not in the in vivo model. CYP1A was suppressed by butyrate in the in vitro experiments, and overexpressed in vivo in butyrate-fed animals. The concomitant incubation of hepatocytes with butyrate and erythromycin led to an increased CYP2H1 expression and a less pronounced inhibition of CYP3A37. In in vivo pharmacokinetic experiments, butyrate-fed animals given a single i.m. injection of erythromycin, a slower absorption phase (longer T(half-abs) and delayed T(max)) but a rapid elimination phase of this marker substrate was observed. Although these measurable differences were detected in the pharmacokinetics of erythromycin, it is unlikely that a concomitant application of sodium butyrate with erythromycin or other CYP substrates will cause clinically significant feed-drug interaction in chickens.
A porcine enterohepatic co-culture system, with primary hepatocytes as bottom layer and IPEC-J2 e... more A porcine enterohepatic co-culture system, with primary hepatocytes as bottom layer and IPEC-J2 epithelial cells as upper layer, was developed to study the effects of lipopolysaccharides (LPS) on the gene expression profile of pro-inflammatory cytokines (interleukin-8 (IL-8) and tumor necrosis factor-α) and CYP enzymes (CYP1A1, CYP1A2, CYP3A29). The barrier integrity of IPEC-J2 cells was investigated by transepithelial electrical resistance measurements and by fluorescein isothiocyanate-dextran-based test. Basolateral IL-8 production was significantly elevated in LPS-treated IPEC-J2 and primary hepatocyte mono-cultures as well as in the co-culture system, in a dose-independent manner. The LPS-induced changes in the expression of the CYP1A2 and CYP3A29 genes in hepatocyte mono-cultures differed from those in co-culture after LPS treatment on the apical side of the IPEC-J2 cell layer. CYP1A2 was downregulated by the LPS treatment in mono-cultures but upregulated at 10 μg/ml LPS in co-culture; gene expression of CYP3A29 showed no significant LPS-induced change in the hepatocyte mono-culture but was significantly downregulated in co-culture. The newly established co-culture system capable of mimicking enterohepatic interplay in LPS-induced inflammatory responses in vitro can be used in the future for reliable screening of potential anti-inflammatory compounds.
An important cost of sexual and social colour signals may be increased conspicuousness of the ani... more An important cost of sexual and social colour signals may be increased conspicuousness of the animals to visual predators. Although such predation costs have repeatedly been proposed for various ornaments of birds, especially for melanised and depigmented signals with low presumed production costs, tests of this hypothesis are rare and inconclusive. In this study we investigated whether individual variation in plumage ornamentation was associated with predator-related risk-taking behaviour and short-term survival in free-living House Sparrows Passer domesticus. In a large sample of birds we measured three aspects of coloration used in sexual and social signalling: the size of the melanised black throat patch in males, and the area and conspicuousness of the depigmented wing-bar in both sexes. We measured risk-taking by manipulating the distance of feeders from shelters, and recorded individually ringed birds feeding close to and far from shelter. Sparrows seemed to perceive the farther feeders as more risky, as indicated by the shorter time spent and smaller groups feeding far from rather than close to shelter. However, the use of the more risky (farther) feeders was not related to any of the colour traits we measured, suggesting that Sparrows do not adjust their risk-taking behaviour to their ornamentation. Males (the more ornamented sex) did not take less risk than females. Furthermore, we found no evidence that larger throat patches or more ornamented wing-bars reduced the probability of survival. Our findings were robust and consistent across multiple approaches, even when we controlled for several potential confounding effects. These results do not support the suggestion that melanised and depigmented plumage ornaments have significant predation costs in House Sparrows.
The aim of the study was to investigate thein vivoepigenetic influences of dietary butyrate suppl... more The aim of the study was to investigate thein vivoepigenetic influences of dietary butyrate supplementation on the acetylation state of core histones and the activity of drug-metabolising microsomal cytochrome P450 (CYP) enzymes in the liver of broiler chickens in the starter period. One-day-old Ross 308 broilers were fed a starter diet without or with sodium butyrate (1.5 g/kg feed) for 21 days. After slaughtering, nucleus and microsome fractions were isolated from the exsanguinated liver by multi-step differential centrifugation. Histone acetylation level was detected from hepatocyte nuclei by Western blotting, while microsomal CYP activity was examined by specific enzyme assays. Hyperacetylation of hepatic histone H2A at lysine 5 was observed after butyrate supplementation, providing modifications in the epigenetic regulation of cell function. No significant changes could be found in the acetylation state of the other core histones at the acetylation sites examined. Furthermore, ...
Urbanization creates novel environments for wild animals where selection pressures may differ dra... more Urbanization creates novel environments for wild animals where selection pressures may differ drastically from those in natural habitats. Adaptation to urban life involves changes in various traits, including behavior. Behavioral traits often vary consistently among individuals, and these so-called personality traits can be correlated with each other, forming behavioral syndromes. Despite their adaptive significance and potential to act as constraints, little is known about the role of animal personality and behavioral syndromes in animals' adaptation to urban habitats. In this study we tested whether differently urbanized habitats select for different personalities and behavioral syndromes by altering the population mean, interindividual variability, and correlations of personality traits. We captured house sparrows (Passer domesticus) from four different populations along the gradient of urbanization and assessed their behavior in standardized test situations. We found individual consistency in neophobia, risk taking, and activity, constituting three personality axes. On the one hand, urbanization did not consistently affect the mean and variance of these traits, although there were significant differences between some of the populations in food neophobia and risk taking (both in means and variances). On the other hand, both urban and rural birds exhibited a behavioral syndrome including object neophobia, risk taking and activity, whereas food neophobia was part of the syndrome only in rural birds. These results indicate that there are population differences in certain aspects of personality in house sparrows, some of which may be related to habitat urbanization. Our findings suggest that urbanization and/or other population-level habitat differences may not only influence the expression of personality traits but also alter their inter-individual variability and the relationships among them, changing the structure of behavioral syndromes.
The short-chain fatty acid butyrate, either in unprotected or protected form, is widely applied a... more The short-chain fatty acid butyrate, either in unprotected or protected form, is widely applied as a growth-promoting feed additive in poultry nutrition; however, its possible effects on the carcass composition of broilers have not been fully elucidated. Further, lowering dietary crude protein (CP) levels is an important issue in poultry farming, contributing to ecologically beneficial lower nitrogen excretion. The main aims of this study were to test how unprotected and protected forms of butyrate and decreased dietary CP content with essential amino acid (lysine, methionine, threonine, tryptophan) supplementation ("LP-EAA" diet) affect carcass parameters and the chemical composition of muscles in broilers. Ross 308 chickens were randomized to seven groups (n = 10/group) receiving adequate CP-containing (normal protein, "NP") or LP-EAA diets, both supplemented with or without unprotected sodium butyrate, and NP diets with different forms of protected sodium butyrate. Carcass traits were measured, and the chemical composition of pectoral and femoral muscles was analyzed at the age of 6 weeks. Carcass weight was significantly increased by the LP-EAA diet and all protected butyrate types tested, while the relative breast meat yield was significantly higher in LP-EAA than NP groups and in both unprotected and protected butyrate-supplemented chickens compared to controls. The protein content of the femoral muscle was significantly decreased, but its lipid content was significantly elevated by the LP-EAA diet and by all types of butyrate addition. However, no changes were detected in the chemical composition of pectoral muscle. In conclusion, breast meat production can be effectively stimulated by dietary factors, such as by reducing dietary CP content with essential amino acid supplementation and by applying butyrate as a feed additive, while its chemical composition remains unchanged, in contrast to the femoral muscle. The aforementioned nutritional strategies seem to be the proper tools to increase carcass yield and to alter meat composition of broilers, contributing to more efficient poultry meat production.
The aim of the present study was to investigate the effects of butyrate as a feed supplement on t... more The aim of the present study was to investigate the effects of butyrate as a feed supplement on the expression of insulin signalling proteins as potent regulators of metabolism and growth in Ross 308 broiler chickens fed maize-or wheatbased diets. Both diets were supplemented with non-protected butyrate (1.5 and 3.0 g/kg of diet, respectively) or with protected butyrate (0.2 g/kg of diet); the diet of the control groups was prepared without any additives (control). On day 42 of life, systemic blood samples were drawn for analyses of glucose and insulin concentrations, and tissue samples (liver, gastrocnemius muscle and subcutaneous adipose tissue) were taken for Western blotting examinations. The expression of key insulin signalling proteins (IRβ, PKCζ and mTOR) was assessed by semiquantitative Western blotting from the tissues mentioned. The type of diet had a remarkable influence on the insulin homeostasis of chickens. The wheat-based diet significantly increased IRβ and mTOR expression in the liver as well as mTOR and PKCζ expression in the adipose tissue when compared to animals kept on a maize-based diet. IRβ expression in the liver was stimulated by the lower dose of non-protected butyrate as well, suggesting the potential of butyrate as a feed additive to affect insulin sensitivity. Based on the results obtained, the present study shows new aspects of nutritional factors by comparing the special effects of butyrate as a feed additive and those of the cereal type, presumably in association with dietary non-starch polysaccharide-(NSP-) driven enteric shortchain fatty acid release including butyrate, influencing insulin homeostasis in chickens. As the tissues of chickens have physiologically lower insulin sensitivity compared to mammals, diet-associated induction of the insulin signalling pathway can be of special importance in improving growth and metabolic health.
This study investigates the metabolic effects of maize-or wheat-based diets with normal (NP) and ... more This study investigates the metabolic effects of maize-or wheat-based diets with normal (NP) and lowered (LP) dietary crude protein level [the latter supplemented with limiting amino acids and sodium (n-)butyrate at 1.5 g/kg diet] at different phases of broiler fattening. Blood samples of Ross 308 broilers were tested at the age of 1, 3 and 6 weeks. Total protein (TP) concentration increased in wheat-based and decreased in LP groups in week 3, while butyrate reduced albumin/ TP ratio in week 1. Uric acid level was elevated by wheat-based diet in week 1 and by wheat-based diet and butyrate in week 3, but decreased in LP groups in weeks 3 and 6. Aspartate aminotransferase activity was increased by wheat-based diet in week 3, and creatine kinase activity was intensified by LP in weeks 3 and 6. Blood glucose level decreased in wheat-based groups in week 3; however, triglyceride concentration was augmented in the same groups in week 3. No change of glucagon-like peptide 1, glucose-dependent insulinotropic polypeptide and insulin concentration was observed. In conclusion, an age-dependent responsiveness of broilers to dietary factors was found, dietary cereal type was a potent modulator of metabolism, and a low crude protein diet supplemented with limiting amino acids might have a beneficial impact on the growth of chickens.
Intestinal cytochrome P450 (CYP) enzymes play key role in the first pass metabolism of orally ing... more Intestinal cytochrome P450 (CYP) enzymes play key role in the first pass metabolism of orally ingested xenobiotics, providing a primary metabolic barrier, being of special importance in maintaining animal health and production. This study was aimed to investigate how intestinal drug-metabolizing CYPs can be modulated by nutritional factors in broiler chicken. We investigated the effects of the natural growth promoter (n-)butyrate of different origin (feed supplementation of protected or non-protected forms and/or inducing caecal microbial production by supporting higher level of dietary non-starch polysaccharides [NSP]) on the activity of duodenal CYPs. To observe the connection between intestinal CYP activity and butyrate concentration, the distribution of differently originated butyrate was also assessed by measuring its concentration in various intestinal segments and different vessels of portal and systemic circulation. Butyrate of different origin showed varying distribution pr...
The influence of butyrate on insulin signaling in chickens was studied because butyrate is produc... more The influence of butyrate on insulin signaling in chickens was studied because butyrate is produced during microbial fermentation in the large intestine of birds and butyrate is widely used as a feed additive in animal production. Ross 308 broiler chickens received a daily intra-ingluvial bolus of sodium butyrate (0.25 g/kg BW) on d 20-24 of life (n = 10). Plasma butyrate concentration increased after receiving oral butyrate treatment (P < 0.001). Oral butyrate application was associated with decreased protein expression of insulin receptor β subunit (IRβ) in liver (P = 0.008) and both abdominal (P = 0.003) and subcutaneous adipose tissue (P < 0.001), but with elevated IRβ expression in muscle (P = 0.045), assessed by Western blotting. The quantity of hepatic phosphatidyl-inositol-3-kinase (PI3K) was reduced in the butyrate-treated group (P = 0.007), further, mammalian target of rapamycin (mTOR) was down-regulated by butyrate in liver (P < 0.001) and subcutaneous adipose ti...
Influencing the endocrine metabolic regulation of chickens by nutritional factors might provide n... more Influencing the endocrine metabolic regulation of chickens by nutritional factors might provide novel possibilities for improving animal health and productivity. This study was designed to evaluate the impact of dietary cereal type (wheat-based (WB) vs. maize-based (MB) diets), crude protein level (normal (NP) vs. lowered (LP)), and sodium (n-)butyrate (1.5 g/kg diet) supplementation (vs. no butyrate) on the responsiveness of hepatic glucagon receptor (GCGR), insulin receptor beta (IRβ) and mammalian target of rapamycin (mTOR) in the phase of intensive growth of chickens. Liver samples of Ross 308 broiler chickens (Gallus gallus domesticus) were collected on day 21 for quantitative real-time polymerase chain reaction and Western blot analyses. Hepatic GCGR and mTOR gene expressions were up-regulated by WB and LP diet. GCGR and IRβ protein level decreased in groups with butyrate supplementation; however, the quantity of IRβ and mTOR protein increased in WB groups. Based on these data...
Effects of orally applied butyrate bolus on histone me P450 enzyme activity Conclusion: Orally ad... more Effects of orally applied butyrate bolus on histone me P450 enzyme activity Conclusion: Orally added butyrate in bolus could cause in vivo hyperacetylation of the hepatic core histones, Mátis et al. Nutrition & Metabolism 2013, 10:12
Dairy cows mobilize large amounts of body fat during early lactation to overcome negative energy ... more Dairy cows mobilize large amounts of body fat during early lactation to overcome negative energy balance which typically arises in this period. As an adaptation process, adipose tis-sues of cows undergo extensive remodeling during late pregnancy and early lactation. The objective of the present study was to characterize this remodeling to get a better under-standing of adaptation processes in adipose tissues, affected by changing metabolic condi-tions including lipid mobilization and refilling as a function of energy status. This was done by determining adipocyte size in histological sections of subcutaneous and retroperitoneal adipose tissue biopsy samples collected from German Holstein cows at 42 days prepartum, and 1, 21, and 100 days postpartum. Characterization of cell size changes was extended by the analysis of DNA, triacylglycerol, and protein content per gram tissue, and β-actin pro-tein expression in the same samples. In both adipose tissue depots cell size was becoming sm...
Orally applied butyrate as a nutritional supplement has a huge impact on the health of the gastro... more Orally applied butyrate as a nutritional supplement has a huge impact on the health of the gastrointestinal epithelium and the gut microflora. In addition, as an epigenetically active molecule, it can also influence the expression of certain genes. Regarding the results of some in vitro studies, butyrate, absorbed from the intestines and taken to the liver by the portal circulation, may alter the action of hepatic microsomal cytochrome P450 (CYP) enzymes, involved in the biotransformation of xenobiotics, having a remarkable importance in food safety, as well. The authors aimed to study the possible effects of orally applied butyrate on hepatic CYP activity in rats after weaning, also serving as a monogastric mammalian model. Animals were fed with normal pelleted stock diet without or with sodium butyrate (1.5 g/kg diet) for 21 days. As a positive control, a group of rats was treated with intraperitoneal phenobarbital injection. Animals were euthanized on day 21, microsomal fractions were separated from the exsanguinated livers by differential centrifugation. The activity of the most important (VP subfamilies was screened by specific enzyme assays (aminopyrine N-demethylation: CYP2B/3A, testosterone 6 beta-hydroxylation: CYP3A). According to the results, butyrate as a feed supplement did not cause any changes in the drug-metabolising activity of the examined hepatic microsomal CYP enzymes. However, phenobarbital significantly (P<0,05) increased the microsomal CYP2B and CYP3A activity of the liver. These data indicate that the supplementation of the diet with butyrate probably may not have any pharmacokinetic interactions with simultaneously applied xenobiotics in monogastric mammals, so it can be applied safely as a nutritional supplement.
BEVEZETÉS A természeti területek városokká alakítása világszerte gyorsuló ütemben zajlik, e termé... more BEVEZETÉS A természeti területek városokká alakítása világszerte gyorsuló ütemben zajlik, e természetvédelmi szempontból is fontos folyamat egyedi és populáció szintű ökológiai hatásait azonban kevéssé ismerjük. A projektben annak vizsgálatát tűztük ki célul, hogy (i) az élőhelyek urbanizációjával miként változik két alapvető populáció-szabályozó tényező, a táplálékkompetíció és a predációs nyomás intenzitása, (ii) hogyan befolyásolja az urbanizáció a madarak viselkedését, stresszélettanát, egészségi állapotát és szaporodási sikerét, és hogy (iii) a városi és vidéki populációk morfológiai és reprodukciós különbségei környezeti hatásoknak vagy a városi életmódhoz való alkalmazkodás evolúciós következményének tudhatók-e be. A fenti kérdések megválaszolásához viselkedési, élettani és szaporodásbiológiai vizsgálatokat végeztünk szabadon élő és fogságban tartott házi verebeken, amelyek az urbanizációs gradiens különböző pontjairól származtak (vidéki, szuburbán, és városi területekről). Az eredetileg tervezett vizsgálatokat a következő módosításokkal végeztük el. A predációs nyomás és a táplálékkompetíció kísérletes terepi vizsgálatát (Munkaterv 1-2. kísérlet) a tervezett két év helyett egy évben végeztük, mivel a vizsgálatot végző PhD hallgató 2009-ben kilépett a PhD képzésből és a projektből, és tervezett feladatainak befejezésére nem volt módunk. Ehelyett egyrészt egy nem tervezett kísérletet végeztünk, amelyben laboratóriumi körülmények között hasonlítottuk össze a városi és vidéki egyedek predációs kockázatvállalását (Eredmények 1.2. pontja). Másrészt a táplálék-ellátottság és kompetíció vizsgálatához az 1. megfigyelést a tervezettnél nagyobb részletességgel végeztük (1.3. pont). A munkatervhez képest szintén jelentős kiegészítés, hogy két éven keresztül vizsgáltuk vadon élő madarak szaporodási sikerét különböző mértékben urbanizált élőhelyeken (1.5. pont), és a tervezett "common garden" kísérlet mellett egy fiókacserés kísérletet is elvégeztünk a környezeti és genetikai hatások fontosságának összehasonlítására (1.6. pont). A módosítások miatt az eredmények publikálásának gyorsasága elmaradt a tervezettől,
How urbanization aff ects animal populations is in the focus of current ecological research. Exis... more How urbanization aff ects animal populations is in the focus of current ecological research. Existing theory of this topic suggests that the cities' more constant food supplies and lower predation pressure lead to a high proportion of weak competitors in urban populations. To evaluate this hypothesis, we tested whether competitive performance diff ers between diff erently urbanized populations of house sparrows Passer domesticus. We previously showed that wild urban sparrows are smaller and leaner than rural conspecifi cs, and this diff erence persists for months under identical captive conditions. Here we compared several aspects of their competitiveness (fi ghting, scrambling and searching for food) in captive mixed fl ocks of urban and rural birds. We found that sparrows exhibited consistent individual diff erences in competitiveness, but these diff erences were not related either to the degree of urbanization of their original habitats or to their body mass. Moreover, the variance in competitive abilities also did not diff er between birds from more and less urbanized habitats. Th us our results did not support the hypothesis that urbanization shifts population structure towards an overabundance of weak competitors in house sparrows. We discuss possible explanations why sparrow populations may not diff er in competitiveness despite the smaller body mass of urban birds.
Background Butyrate is known as histone deacetylase inhibitor, inducing histone hyperacetylation ... more Background Butyrate is known as histone deacetylase inhibitor, inducing histone hyperacetylation in vitro and playing a predominant role in the epigenetic regulation of gene expression and cell function. We hypothesized that butyrate, endogenously produced by intestinal microbial fermentation or applied as a nutritional supplement, might cause similar in vivo modifications in the chromatin structure of the hepatocytes, influencing the expression of certain genes and therefore modifying the activity of hepatic microsomal drug-metabolizing cytochrome P450 (CYP) enzymes. Methods An animal study was carried out in chicken as a model to investigate the molecular mechanisms of butyrate’s epigenetic actions in the liver. Broiler chicks in the early post-hatch period were treated once daily with orally administered bolus of butyrate following overnight starvation with two different doses (0.25 or 1.25 g/kg body weight per day) for five days. After slaughtering, cell nucleus and microsomal f...
Social behaviour of group-living animals is often influenced by the relatedness of individuals, t... more Social behaviour of group-living animals is often influenced by the relatedness of individuals, thus understanding the genetic structure of groups is important for the interpretation of costs and benefits of social interactions. In this study, we investigated genetic relatedness in feeding aggregations of free-living house sparrows (Passer domesticus) during the nonbreeding season. This species is a frequent model system for studies of social behaviour (e.g. aggression, social foraging), but we lack adequate information on the kin structure of sparrow flocks. During two winters, we ringed and observed sparrows at feeding stations, and used resightings to identify stable flockmembers and to calculate association indices between birds. We genotyped the birds using seven highly polymorphic microsatellite loci, and estimated pairwise relatedness coefficients and relatedness categories (close kin vs. unrelated) by maximum likelihood method. We found that most birds were unrelated to each other in the flocks (mean ± SE relatedness coefficient: 0.06 ± 0.002), although most individuals had at least a few close relatives in their home flock (14.3 ± 0.6% of flock-mates). Pairwise association between individuals was not significantly related to their genetic relatedness. Furthermore, there was no difference between within-flock vs. between-flock relatedness, and birds had similar proportions of close kin within and outside their home flock. Finally, relatedness among members of different flocks was unrelated to the distance between their flocks. Thus, sparrow flocks were not characterized by association of relatives, nevertheless the presence of some close kin may provide opportunity for kin-biased behaviours to evolve.
Journal of Veterinary Pharmacology and Therapeutics, 2014
Butyrate, a commonly applied feed additive in poultry nutrition, can modify the expression of cer... more Butyrate, a commonly applied feed additive in poultry nutrition, can modify the expression of certain genes, including those encoding cytochrome P450 (CYP) enzymes. In comparative in vitro and in vivo experiments, the effect of butyrate on hepatic CYP genes was examined in primary cultures of chicken hepatocytes and in liver samples of chickens collected from animals that had been given butyrate as a feed additive. Moreover, the effect of butyrate on the biotransformation of erythromycin, a marker substance for the activity of enzymes of the CYP3A family, was investigated in vitro and in vivo. Butyrate increased the expression of the avian-specific CYP2H1 both in vitro and in vivo. In contrast, the avian CYP3A37 expression was decreased in hepatocytes following butyrate exposure, but not in the in vivo model. CYP1A was suppressed by butyrate in the in vitro experiments, and overexpressed in vivo in butyrate-fed animals. The concomitant incubation of hepatocytes with butyrate and erythromycin led to an increased CYP2H1 expression and a less pronounced inhibition of CYP3A37. In in vivo pharmacokinetic experiments, butyrate-fed animals given a single i.m. injection of erythromycin, a slower absorption phase (longer T(half-abs) and delayed T(max)) but a rapid elimination phase of this marker substrate was observed. Although these measurable differences were detected in the pharmacokinetics of erythromycin, it is unlikely that a concomitant application of sodium butyrate with erythromycin or other CYP substrates will cause clinically significant feed-drug interaction in chickens.
A porcine enterohepatic co-culture system, with primary hepatocytes as bottom layer and IPEC-J2 e... more A porcine enterohepatic co-culture system, with primary hepatocytes as bottom layer and IPEC-J2 epithelial cells as upper layer, was developed to study the effects of lipopolysaccharides (LPS) on the gene expression profile of pro-inflammatory cytokines (interleukin-8 (IL-8) and tumor necrosis factor-α) and CYP enzymes (CYP1A1, CYP1A2, CYP3A29). The barrier integrity of IPEC-J2 cells was investigated by transepithelial electrical resistance measurements and by fluorescein isothiocyanate-dextran-based test. Basolateral IL-8 production was significantly elevated in LPS-treated IPEC-J2 and primary hepatocyte mono-cultures as well as in the co-culture system, in a dose-independent manner. The LPS-induced changes in the expression of the CYP1A2 and CYP3A29 genes in hepatocyte mono-cultures differed from those in co-culture after LPS treatment on the apical side of the IPEC-J2 cell layer. CYP1A2 was downregulated by the LPS treatment in mono-cultures but upregulated at 10 μg/ml LPS in co-culture; gene expression of CYP3A29 showed no significant LPS-induced change in the hepatocyte mono-culture but was significantly downregulated in co-culture. The newly established co-culture system capable of mimicking enterohepatic interplay in LPS-induced inflammatory responses in vitro can be used in the future for reliable screening of potential anti-inflammatory compounds.
An important cost of sexual and social colour signals may be increased conspicuousness of the ani... more An important cost of sexual and social colour signals may be increased conspicuousness of the animals to visual predators. Although such predation costs have repeatedly been proposed for various ornaments of birds, especially for melanised and depigmented signals with low presumed production costs, tests of this hypothesis are rare and inconclusive. In this study we investigated whether individual variation in plumage ornamentation was associated with predator-related risk-taking behaviour and short-term survival in free-living House Sparrows Passer domesticus. In a large sample of birds we measured three aspects of coloration used in sexual and social signalling: the size of the melanised black throat patch in males, and the area and conspicuousness of the depigmented wing-bar in both sexes. We measured risk-taking by manipulating the distance of feeders from shelters, and recorded individually ringed birds feeding close to and far from shelter. Sparrows seemed to perceive the farther feeders as more risky, as indicated by the shorter time spent and smaller groups feeding far from rather than close to shelter. However, the use of the more risky (farther) feeders was not related to any of the colour traits we measured, suggesting that Sparrows do not adjust their risk-taking behaviour to their ornamentation. Males (the more ornamented sex) did not take less risk than females. Furthermore, we found no evidence that larger throat patches or more ornamented wing-bars reduced the probability of survival. Our findings were robust and consistent across multiple approaches, even when we controlled for several potential confounding effects. These results do not support the suggestion that melanised and depigmented plumage ornaments have significant predation costs in House Sparrows.
The aim of the study was to investigate thein vivoepigenetic influences of dietary butyrate suppl... more The aim of the study was to investigate thein vivoepigenetic influences of dietary butyrate supplementation on the acetylation state of core histones and the activity of drug-metabolising microsomal cytochrome P450 (CYP) enzymes in the liver of broiler chickens in the starter period. One-day-old Ross 308 broilers were fed a starter diet without or with sodium butyrate (1.5 g/kg feed) for 21 days. After slaughtering, nucleus and microsome fractions were isolated from the exsanguinated liver by multi-step differential centrifugation. Histone acetylation level was detected from hepatocyte nuclei by Western blotting, while microsomal CYP activity was examined by specific enzyme assays. Hyperacetylation of hepatic histone H2A at lysine 5 was observed after butyrate supplementation, providing modifications in the epigenetic regulation of cell function. No significant changes could be found in the acetylation state of the other core histones at the acetylation sites examined. Furthermore, ...
Urbanization creates novel environments for wild animals where selection pressures may differ dra... more Urbanization creates novel environments for wild animals where selection pressures may differ drastically from those in natural habitats. Adaptation to urban life involves changes in various traits, including behavior. Behavioral traits often vary consistently among individuals, and these so-called personality traits can be correlated with each other, forming behavioral syndromes. Despite their adaptive significance and potential to act as constraints, little is known about the role of animal personality and behavioral syndromes in animals' adaptation to urban habitats. In this study we tested whether differently urbanized habitats select for different personalities and behavioral syndromes by altering the population mean, interindividual variability, and correlations of personality traits. We captured house sparrows (Passer domesticus) from four different populations along the gradient of urbanization and assessed their behavior in standardized test situations. We found individual consistency in neophobia, risk taking, and activity, constituting three personality axes. On the one hand, urbanization did not consistently affect the mean and variance of these traits, although there were significant differences between some of the populations in food neophobia and risk taking (both in means and variances). On the other hand, both urban and rural birds exhibited a behavioral syndrome including object neophobia, risk taking and activity, whereas food neophobia was part of the syndrome only in rural birds. These results indicate that there are population differences in certain aspects of personality in house sparrows, some of which may be related to habitat urbanization. Our findings suggest that urbanization and/or other population-level habitat differences may not only influence the expression of personality traits but also alter their inter-individual variability and the relationships among them, changing the structure of behavioral syndromes.
The short-chain fatty acid butyrate, either in unprotected or protected form, is widely applied a... more The short-chain fatty acid butyrate, either in unprotected or protected form, is widely applied as a growth-promoting feed additive in poultry nutrition; however, its possible effects on the carcass composition of broilers have not been fully elucidated. Further, lowering dietary crude protein (CP) levels is an important issue in poultry farming, contributing to ecologically beneficial lower nitrogen excretion. The main aims of this study were to test how unprotected and protected forms of butyrate and decreased dietary CP content with essential amino acid (lysine, methionine, threonine, tryptophan) supplementation ("LP-EAA" diet) affect carcass parameters and the chemical composition of muscles in broilers. Ross 308 chickens were randomized to seven groups (n = 10/group) receiving adequate CP-containing (normal protein, "NP") or LP-EAA diets, both supplemented with or without unprotected sodium butyrate, and NP diets with different forms of protected sodium butyrate. Carcass traits were measured, and the chemical composition of pectoral and femoral muscles was analyzed at the age of 6 weeks. Carcass weight was significantly increased by the LP-EAA diet and all protected butyrate types tested, while the relative breast meat yield was significantly higher in LP-EAA than NP groups and in both unprotected and protected butyrate-supplemented chickens compared to controls. The protein content of the femoral muscle was significantly decreased, but its lipid content was significantly elevated by the LP-EAA diet and by all types of butyrate addition. However, no changes were detected in the chemical composition of pectoral muscle. In conclusion, breast meat production can be effectively stimulated by dietary factors, such as by reducing dietary CP content with essential amino acid supplementation and by applying butyrate as a feed additive, while its chemical composition remains unchanged, in contrast to the femoral muscle. The aforementioned nutritional strategies seem to be the proper tools to increase carcass yield and to alter meat composition of broilers, contributing to more efficient poultry meat production.
The aim of the present study was to investigate the effects of butyrate as a feed supplement on t... more The aim of the present study was to investigate the effects of butyrate as a feed supplement on the expression of insulin signalling proteins as potent regulators of metabolism and growth in Ross 308 broiler chickens fed maize-or wheatbased diets. Both diets were supplemented with non-protected butyrate (1.5 and 3.0 g/kg of diet, respectively) or with protected butyrate (0.2 g/kg of diet); the diet of the control groups was prepared without any additives (control). On day 42 of life, systemic blood samples were drawn for analyses of glucose and insulin concentrations, and tissue samples (liver, gastrocnemius muscle and subcutaneous adipose tissue) were taken for Western blotting examinations. The expression of key insulin signalling proteins (IRβ, PKCζ and mTOR) was assessed by semiquantitative Western blotting from the tissues mentioned. The type of diet had a remarkable influence on the insulin homeostasis of chickens. The wheat-based diet significantly increased IRβ and mTOR expression in the liver as well as mTOR and PKCζ expression in the adipose tissue when compared to animals kept on a maize-based diet. IRβ expression in the liver was stimulated by the lower dose of non-protected butyrate as well, suggesting the potential of butyrate as a feed additive to affect insulin sensitivity. Based on the results obtained, the present study shows new aspects of nutritional factors by comparing the special effects of butyrate as a feed additive and those of the cereal type, presumably in association with dietary non-starch polysaccharide-(NSP-) driven enteric shortchain fatty acid release including butyrate, influencing insulin homeostasis in chickens. As the tissues of chickens have physiologically lower insulin sensitivity compared to mammals, diet-associated induction of the insulin signalling pathway can be of special importance in improving growth and metabolic health.
This study investigates the metabolic effects of maize-or wheat-based diets with normal (NP) and ... more This study investigates the metabolic effects of maize-or wheat-based diets with normal (NP) and lowered (LP) dietary crude protein level [the latter supplemented with limiting amino acids and sodium (n-)butyrate at 1.5 g/kg diet] at different phases of broiler fattening. Blood samples of Ross 308 broilers were tested at the age of 1, 3 and 6 weeks. Total protein (TP) concentration increased in wheat-based and decreased in LP groups in week 3, while butyrate reduced albumin/ TP ratio in week 1. Uric acid level was elevated by wheat-based diet in week 1 and by wheat-based diet and butyrate in week 3, but decreased in LP groups in weeks 3 and 6. Aspartate aminotransferase activity was increased by wheat-based diet in week 3, and creatine kinase activity was intensified by LP in weeks 3 and 6. Blood glucose level decreased in wheat-based groups in week 3; however, triglyceride concentration was augmented in the same groups in week 3. No change of glucagon-like peptide 1, glucose-dependent insulinotropic polypeptide and insulin concentration was observed. In conclusion, an age-dependent responsiveness of broilers to dietary factors was found, dietary cereal type was a potent modulator of metabolism, and a low crude protein diet supplemented with limiting amino acids might have a beneficial impact on the growth of chickens.
Intestinal cytochrome P450 (CYP) enzymes play key role in the first pass metabolism of orally ing... more Intestinal cytochrome P450 (CYP) enzymes play key role in the first pass metabolism of orally ingested xenobiotics, providing a primary metabolic barrier, being of special importance in maintaining animal health and production. This study was aimed to investigate how intestinal drug-metabolizing CYPs can be modulated by nutritional factors in broiler chicken. We investigated the effects of the natural growth promoter (n-)butyrate of different origin (feed supplementation of protected or non-protected forms and/or inducing caecal microbial production by supporting higher level of dietary non-starch polysaccharides [NSP]) on the activity of duodenal CYPs. To observe the connection between intestinal CYP activity and butyrate concentration, the distribution of differently originated butyrate was also assessed by measuring its concentration in various intestinal segments and different vessels of portal and systemic circulation. Butyrate of different origin showed varying distribution pr...
The influence of butyrate on insulin signaling in chickens was studied because butyrate is produc... more The influence of butyrate on insulin signaling in chickens was studied because butyrate is produced during microbial fermentation in the large intestine of birds and butyrate is widely used as a feed additive in animal production. Ross 308 broiler chickens received a daily intra-ingluvial bolus of sodium butyrate (0.25 g/kg BW) on d 20-24 of life (n = 10). Plasma butyrate concentration increased after receiving oral butyrate treatment (P < 0.001). Oral butyrate application was associated with decreased protein expression of insulin receptor β subunit (IRβ) in liver (P = 0.008) and both abdominal (P = 0.003) and subcutaneous adipose tissue (P < 0.001), but with elevated IRβ expression in muscle (P = 0.045), assessed by Western blotting. The quantity of hepatic phosphatidyl-inositol-3-kinase (PI3K) was reduced in the butyrate-treated group (P = 0.007), further, mammalian target of rapamycin (mTOR) was down-regulated by butyrate in liver (P < 0.001) and subcutaneous adipose ti...
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Papers by Anna Kulcsár