Zinc glycinate alleviates LPS-induced inflammation and intestinal barrier disruption in chicken embryos by regulating zinc homeostasis and TLR4/NF-κB pathway.

The effect of an immune challenge induced by a lipopolysaccharide (LPS) exposure on systemic zinc homeostasis and the modulation of zinc glycinate (Zn-Gly) was investigated using a chicken embryo model. 160 Arbor Acres broiler fertilized eggs were randomly divided into 4 groups: CON (control group, injected with saline), LPS (LPS group, injected with 32 µg of LPS saline solution), Zn-Gly (zinc glycinate group, injected with 80 µg of zinc glycinate saline solution) and Zn-Gly+LPS (zinc glycinate and LPS group, injected with the same content of zinc glycinate and LPS saline solution). Each treatment consisted of eight replicates of five eggs each. An in ovo feeding procedure was performed at 17.5 embryonic day and samples were collected after 12 hours. The results showed that Zn-Gly attenuated the effects of LPS challenge-induced upregulation of pro-inflammatory factor interleukin 1ß (IL-1ß) level (P =0.003). The LPS challenge mediated zinc transporter proteins and metallothionein (MT) to regulate systemic zinc homeostasis, with increased expression of the jejunum zinc export gene zinc transporter protein 1 (ZnT-1) and elevated expression of the import genes divalent metal transporter 1 (DMT1), Zrt- and Irt-like protein 3 (Zip3), Zip8 and Zip14 (P < 0.05). A similar trend could be observed for the zinc transporter genes in the liver, which for ZnT-1 mitigated by Zn-Gly supplementation (P =0.01). Liver MT gene expression was downregulated in response to the LPS challenge (P =0.004). These alterations caused by LPS resulted in decreased serum and liver zinc levels and increased small intestinal, muscle and tibial zinc levels. Zn-Gly reversed the elevated expression of the liver zinc finger protein A20 induced by the LPS challenge (P =0.025), while Zn-Gly reduced the gene expression of the pro-inflammatory factors IL-1ß and IL-6, decreased toll-like receptor 4 (TLR4) and nuclear factor kappa-B p65 (NF-κB p65) (P < 0.05). Zn-Gly also alleviated the LPS-induced downregulation of the intestinal barrier gene Claudin-1. Thus, LPS exposure prompted the mobilization of zinc transporter proteins and MT to perform the remodeling of systemic zinc homeostasis, Zn-Gly participated in the regulation of zinc homeostasis and inhibited the production of pro-inflammatory factors through the TLR4/NF-κB pathway, attenuating the inflammatory response and intestinal barrier damage caused by an immune challenge.

Intestinal dysbiosis in nonalcoholic fatty liver disease (NAFLD): focusing on the gut-liver axis.

Nonalcoholic fatty liver disease (NAFLD) is one of the most common chronic liver disorders in humans, partly because it is closely related to metabolic disorders of the liver with increasing prevalence. NAFLD begins with hepatic lipid accumulation, which may cause inflammation and eventually lead to fibrosis in the liver. Numerous studies have demonstrated the close relationship between gut dysfunction (especially the gut microbiota and its metabolites) and the occurrence and progression of NAFLD. The bidirectional communication between the gut and liver, named the gut-liver axis, is mainly mediated by the metabolites derived from both the liver and gut through the biliary tract, portal vein, and systemic circulation. Herein, we review the effects of the gut-liver axis on the pathogenesis of NAFLD. We also comprehensively describe the potential molecular mechanisms from the perspective of the role of liver-derived metabolites and gut-related components in hepatic metabolism and inflammation and gut health, respectively. The study provides insights into the mechanisms underlying current summarizations that support the intricate interactions between a disordered gut and NAFLD and can provide novel strategies to lessen the prevalence and consequence of NAFLD.

Influence of temperature during incubation on the mRNA levels of temperature sensitive ion channels in the brain of broiler chicken embryos.

Thermosensation is crucial for the survival of any organism. In animals, changes in brain temperature are detected via sensory neurons, their cell bodies are located in the trigeminal ganglia. Transient receptor potential (TRP) ion channels are the largest temperature sensing family. In mammals, 11 thermoTRPs are known, as in poultry, there are only three. This research further elucidates TRP mRNA expression in the brain of broiler embryo's. Three incubation treatments were conducted on 400 eggs each: the control (C) at 37.6 °C; T1 deviating from C by providing a + 1 °C heat stimuli during embryonic day (ED) 15-20 for 8 h a day; and T2, imposing a + 2 °C heat stimuli. After each heat stimuli, 12 eggs per treatment were taken for blood sampling from the chorioallantoic membrane and brain harvesting. Incubation parameters such has residual yolk (free embryonic) weight, chick quality and hatch percentage were collected. After primer optimization, 22 target genes (13 TRPs and 9 non-TRPs) were measured on mRNA of the brain using a nanofluidic biochip (Fluidigm Corporation). Four target genes (ANO2, TRPV1, SCN5A, TRAAK) have a significant treatment effect - independent of ED. Another four (TRPM8, TRPA1, TRPM2, TRPC3) have a significant treatment effect visible on one or more ED. Heat sensitive channels were increased in T2 and to a lesser degree in T1, which could be part of an acclimatisation process resulting in later life heat tolerance by increased heat sensitivity. T2, however, resulted in a lower hatch weight, quality and hatchability. No hormonal differences were detected.

Maternal dietary resistant starch does not improve piglet's gut and liver metabolism when challenged with a high fat diet.

BACKGROUND: In the past several years, the use of resistant starch (RS) as prebiotic has extensively been studied in pigs, and this mostly in the critical period around weaning. RS is believed to exert beneficial effects on the gastrointestinal tract mainly due to higher levels of short chain fatty acids (SCFAs) and an improved microbiota profile. In this study, sows were fed digestible starch (DS) or RS during late gestation and lactation and the possible maternal effect of RS on the overall health of the progeny was assessed. Since RS is also described to have a positive effect on metabolism, and to investigate a metabolic programming of the progeny, half of the piglets per maternal diet were assigned to a high fat diet from weaning on to 10 weeks after. RESULTS: No bodyweight differences were found between the four experimental piglet groups. The high fat diet did however impact back fat thickness and meat percentage whereas maternal diet did not influence these parameters. The impact of the high fat diet was also reflected in higher levels of serum cholesterol. No major differences in microbiota could be distinguished, although higher levels of SCFA were seen in the colon of piglets born from RS fed sows, and some differences in SCFA production were observed in the caecum, mainly due to piglet diet. RNA-sequencing on liver and colon scrapings revealed minor differences between the maternal diet groups. Merely a handful of genes was differentially expressed between piglets from DS and RS sows, and network analysis showed only one significant cluster of genes in the liver due to the maternal diet that did not point to meaningful biological pathways. However, the high fat diet resulted in liver gene clusters that were significantly correlated with piglet diet, of which one is annotated for lipid metabolic processes. These clusters were not correlated with maternal diet. CONCLUSIONS: There is only a minor impact of maternal dietary RS on the progeny, reflected in SCFA changes. A high fat diet given to the progeny directly evokes metabolic changes in the liver, without any maternal programming by a RS diet.

In vitro prebiotic potential of agricultural by-products on intestinal fermentation, gut barrier and inflammatory status of piglets.

The inclusion of fibre-rich ingredients in diets is one possible strategy to enhance intestinal fermentation and positively impact gut ecology, barrier and immunity. Nowadays, inulin-type fructans are used as prebiotics in the feed of piglets to manipulate gut ecology for health purposes. Likewise, some by-products could be considered as sustainable and inexpensive ingredients to reduce gut disorders at weaning. In the present study, chicory root and pulp, citrus pulp, rye bran and soya hulls were tested in a three-step in vitro model of the piglet's gastro-intestinal tract combining a pepsin-pancreatin hydrolysis (digestion), a dialysis step using cellulose membranes (absorption) and a colonic batch fermentation (fermentation). The fermentation kinetics, SCFA and microbiota profiles in the fermentation broth were assessed as indicators of prebiotic activity and compared with the ones of inulin. The immunomodulatory effects of fermentation supernatant (FS) were investigated in cultured intestinal porcine epithelial cells (IPEC-J2) by high-throughput quantitative PCR. Chicory root displayed a rapid and extensive fermentation and induced the second highest butyrate ratio after inulin. Citrus pulp demonstrated high acetate ratios and induced elevated Clostridium clusters IV and XIVa levels. Chicory root and pulp FS promoted the intestinal barrier integrity with up-regulated tight and adherens junction gene expressions in comparison with inulin FS. Chicory pulp FS exerted anti-inflammatory effects in cultured IPEC-J2. The novel approach combining an in vitro fermentation model with IPEC-J2 cells highlighted that both chicory root and pulp appear to be promising ingredients and should be considered to promote intestinal health at weaning.

In vitro approach to evaluate the fermentation pattern of inulin-rich food in obese individuals.

Alterations of the gut microbiome have been associated with obesity and metabolic disorders. The gut microbiota can be influenced by the intake of dietary fibres with prebiotic properties, such as inulin-type fructans. The present study tested the hypothesis that obese individuals subjected for 12 weeks to an inulin-enriched v. inulin-poor diet have differential faecal fermentation patterns. The fermentation of cellulose and inulin hydrolysates of six different inulin-rich and inulin-poor vegetables of both groups was analysed in vitro on faecal inocula. The results showed that the microbiota from obese patients who received a fructan-rich diet for 3 weeks produces more gas and total SCFA compared with the microbiota taken from the same individuals before the treatment. Obese individuals fed with a low-fructan diet produce less gas and less SCFA compared with the treated group. The present study highlighted profound changes in microbiota fermentation capacity obtained by prebiotic intervention in obese individuals, which favours the production of specific bioactive metabolites.

Effects of sex and fasting/refeeding on hepatic AMPK signaling in chickens (Gallus gallus).

The alpha-1 isoform of chicken AMPK situates on the Z-chromosome, in contrast, the other isoforms in birds and the mammalian AMPKα1 are located on the autosomes. The present study aimed to investigate the role of hepatic AMPK signaling in adaptation to nutritional status and the potential sex-specific response in chickens. Hepatic genes and proteins were compared between the two sexes immediately after hatching. From 20d of age, chicks from each sex received feed treatments: Control was fed ad libitum; Fasted was starved for 24 h; Refed was fed for 4 h after a 24 h fasting. As a result, hepatic AMPKα1 mRNA level in males was significantly higher at both ages compared to females, due to the presence of Z-chromosomes. However, this did not make this kinase "male-bias" as it was eventually compensated at a translational level, which was not reported in previous studies. The protein levels and activation of AMPKα were even lower in newly-hatched male compared to female chicks, accompanied with a higher FAS and SREBP-1 gene expressions. Accordingly, hepatic G6PC2 mRNA levels in males were significantly lower associated with lower plasma glucose levels after hatching. Fasting activated hepatic AMPK, which in turn inhibited gene expression of GS, FAS and SREBP-1, and stimulated the downstream G6PC2 in both sexes. These changes recovered after refeeding. In conclusion, AMPK plays a role in adaptation to nutritional environment for both sexes. The Z-linked AMPK did not exert a sex-specific signaling, due to a "translational compensation" of AMPKα1.

Overexpression of Soybean-Derived Lunasin in Wheat and Assessment of Its Anti-Proliferative Activity in Colorectal Cancer HT-29 Cells.

Lunasin is a soybean-derived peptide that exhibits anticancer bioactivity in different cancer cells and has been identified in different plants. However, recent studies revealed through molecular and chemical analyses that lunasin was absent in wheat and other cereals. In this study, the soybean-derived lunasin was cloned into pCAMBIA3300 and we transferred the expression vector into wheat via an Agrobacterium-mediated transformation. The identification of transgenic wheat was detected by polymerase chain reaction, Western blot analysis, and ultra-performance liquid chromatography with tandem mass spectrometry. An enzyme-linked immunosorbent assay showed that lunasin content in transgenic wheat L32-3, L32-6, and L33-1 was 308.63, 436.78, and 349.07 µg/g, respectively, while lunasin was not detected in wild-type wheat. Lunasin enrichment from transgenic wheat displayed an increased anti-proliferative activity compared with peptide enrichment from wild-type wheat in HT-29 cells. Moreover, the results of a real-time quantitative polymerase chain reaction showed a significant elevation in p21, Bax, and caspase-3 expression, while Bcl-2 was significantly downregulated. In conclusion, soybean-derived lunasin was successfully expressed in wheat via Agrobacterium-mediated transformation and may exert anti-proliferative activity by regulating the apoptosis pathway in HT-29 cells, which provides an effective approach to compensate for the absence of lunasin in wheat.

Antihypertensive effect of quinoa protein under simulated gastrointestinal digestion and peptide characterization.

BACKGROUND: Quinoa protein is a potential source of bioactive peptides. Although some studies have demonstrated its angiotensin converting enzyme (ACE) inhibitory properties, research into its in vivo effect on blood-pressure regulation and peptide characterization remains limited. RESULTS: Quinoa protein hydrolyzate (QPH) was prepared by simulated gastrointestinal digestion. QPH lowered the systolic blood pressure (SBP) and diastolic blood pressure (DBP) in spontaneously hypertensive model rats (SHRs) from 2 h to10 h after oral administration, effectively controlling blood pressure in these SHRs. An in vitro study showed that QPH is capable of inhibiting ACE activity. This was attributed to the activity of a number of low-molecular-weight peptides. With relatively high scores predicted by PeptideRanker, three promising bioactive peptides, FHPFPR, NWFPLPR, and NIFRPF, were further studied and their ACE-inhibition effects were confirmed with IC50 values of 34.92, 16.77, and 32.40 µM, respectively. A molecular docking study provided insights into the binding of ACE with peptides, and revealed that the presence of specific amino acids in the peptide sequence (Pro, Phe, and Arg at the C-terminal, and Asn at the N-terminal) could contribute to the interaction between ACE and peptides. CONCLUSION: These results demonstrated the potential of QPH for the management of hypertension, which indicates that it could be a good candidate for inclusion in functional foods to control high blood pressure. © 2020 Society of Chemical Industry.

Alteration in bile acids profile in Large White pigs during chronic heat exposure.

Bile acids (BAs) are critical for cholesterol homeostasis and new roles in metabolism and endocrinology have been demonstrated recently. It remains unknown whether BA metabolism can be affected by heat stress (HS). The objective of this study was to describe the shifts in serum, hepatic and intestinal BA profiles induced by chronic HS. Twenty-seven Large White pigs weighing 40.8 ±â€¯2.7 kg were assigned to one of the three treatments: a control group (CON, 23 °C), a HS group (33 °C), or a pair-fed group (PF, 23 °C and fed the same amount as HS group) for 21 d. The concentrations of taurine-conjugated BAs (TUDCA and THDCA in serum and TCDCA, TUDCA, THDCA and THCA in liver) were decreased in HS and PF pigs. However, in HS pigs, a reduction in taurine-conjugated BAs (TCBA) correlated with decreased liver genes expression of BA synthesis, conjugation and uptake transport. BA regulated-genes (FXR, TGR5 and FGFR4) in HS pigs and TGR5, FGFR4 and KLß in PF pigs were down-regulated in liver. In ileum, total BAs and glycoursodeoxycholic acid concentrations were higher in HS pigs than other groups and PF group, respectively (P < 0.05). TCBA (P = 0.01) and tauroursodeoxycholic acid (P < 0.01) were decreased in PF group. BA transporters (OSTα and MRP3) were up-regulated in HS pigs compared with CON and PF pigs, respectively (P < 0.01). In cecum, ursodeoxycholic acid was higher in HS (P = 0.02) group than CON group. The expression of apical sodium-coupled bile acid transporter (P = 0.04) was lower in HS pigs than CON pigs, while OSTß (P < 0.01) was greater in HS group than PF group. These results suggest that chronic HS suppressed liver activity of synthesis and uptake of TCBA, at least in part, which was independent of reduced feed intake.

Revealing the regional distribution of soybean lunasin content in China and the effects of climate factors by sampling extensively.

BACKGROUND: Lunasin is a novel therapeutic peptide that was initially isolated from soybean. In this study, we quantified the variations in lunasin content in a total of 413 soybean samples that were collected from four major regions in China and harvested in 2014 and 2015 to reveal the regional distribution of soybean lunasin content in China and the effects of climate factors. RESULTS: The results showed that the cultivar Changmidou 30 collected from Jilin province and harvested in 2015 had the highest lunasin content (3.25 g kg-1 dry seeds). The data from both 2014 and 2015 showed that the lunasin content in soybean collected from northern China was significantly higher (P < 0.05) than that from south China. There was a positive correlation (P < 0.01) between lunasin content and hours of sunshine (HS) as well as diurnal temperature range (DTR); however, there was a negative correlation (P < 0.01) between lunasin content and rainfall (RF). In addition, combined analysis of data from 2014 and 2015 demonstrated that DTR was the dominant factor that affected lunasin content with a direct path-coefficient of 0.301. CONCLUSIONS: These results were anticipated to contribute to guiding the cultivation of soybean with high lunasin content. © 2018 Society of Chemical Industry.

Fermentation capacities of fructan- and pectin-rich by-products and purified fractions via an in vitro piglet faecal model.

BACKGROUND: Dietary strategies such as the inclusion of prebiotics have been suggested for modulating intestinal microbiota. In piglets, this strategy could result in a reduction of post-weaning-associated disorders and the use of antibiotics. To date, mainly purified fractions have been tested for their prebiotic effects at weaning while trials of potential health-promoting effects of products and corresponding by-products remain rare. In this study, fructan- and pectin-based ingredients have been tested in a two-step in vitro model for their fermentation kinetics as well as for their short-chain fatty acid production and microbiota profiles in fermentation broth as indicators for their prebiotic activity. RESULTS: Chicory root, in contrast to chicory pulp, exhibited an extensive and rapid fermentation similar to inulin and oligofructose, although butyrate levels of root and pulp did not reach those of the purified fractions. Chicory pulp showed higher relative levels of Lactobacillus spp., Bifidobacterium spp., Clostridium cluster IV and butyryl-CoA:acetate-CoA transferase gene abundance compared to chicory root. Sugar beet pulp, orange and citrus by-products displayed extensive gas fermentation patterns, equivalent to those of purified pectin, and revealed an elevated butyrate production compared to purified pectin. Moreover, several orange and citrus by-products displayed significantly higher relative levels of Bifidobacterium spp. in comparison to purified pectin. CONCLUSIONS: Chicory root and pulp as well as orange and citrus by-products appear to be promising ingredients for piglet diets for modulating intestinal fermentation for health purposes. © 2019 Society of Chemical Industry.

The effect of Epigallocatechin-3-gallate on small intestinal morphology, antioxidant capacity and anti-inflammatory effect in heat-stressed broilers.

This study was to investigate the effects of Epigallocatechin-3-gallate (EGCG) on intestinal morphology, antioxidant capacity and anti-inflammatory response in heat-stressed broiler. A total of 192 2-week-old Arbour Acres broilers chickens were divided into four groups with six replicates per group and eight chickens per replicate: one thermoneutral control group (28°C, group TN), which was fed the basal diet; and three cyclic high-temperature groups (35°C from 7:00 to 19:00 hr; 28°C from 19:00 hr to 7:00 hr, heat stress group), which were fed the basal diet supplementation with EGCG 0 mg/kg (group HS0), 300 mg/kg (group HS300) and 600 mg/kg (group HS600). The gut morphology and intestinal mucosal oxidative stress indicators, as well as intestinal barrier-related gene expression, were analysed. The results showed that compared with group TN, heat stress reduced the villus height (VH), activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD)and catalase (CAT), increased the crypt depth (CD) and malondialdehyde (MDA)content at 21, 28 and 35 days (p < 0.05). After the heat-stressed broilers were supplemented with EGCG, VH, VH/CD (V/C), and the activities of GSH-Px, SOD and CAT were increased, and CD and MDA content were reduced compared with those in group HS0 without EGCG supplementation at 21, 28 and 35 days (p < 0.05). The EGCG supplementation promoted the gene expression of nuclear factor-erythroid 2-related factor 2 (Nrf2), Claudin-1, Mucin 2 (Muc2) and alleviated the nuclear factor-kappa B (NF-κB) and lipopolysaccharide-induced tumour necrosis factor (LITAF) gene expression compared with group HS0 (p < 0.05). Moreover, intestinal morphology was strongly correlated with antioxidant ability and inflammatory response. In conclusion, EGCG alleviated the gut oxidative injury of heat-stressed broilers by enhancing antioxidant capacity and inhibiting inflammatory response.

Characterization of fructans and dietary fibre profiles in raw and steamed vegetables.

Dietary fibre (DF) has many positive effects on human health associated with its functionality in the gastrointestinal tract. These benefits vary according to the type of DF. Vegetables can be a natural source of DF in the diet. However, to provide adequate nutritional advice, the content and profile of their various DF types must be characterised. This study aimed to determine the DF profile of 29 vegetables cultivated in Wallonia (Belgium) and the impact of steaming on these profiles. Using a combination of enzymatic, gravimetric and chromatographic methods, fructans, total dietary fibre (TDF), low- and high-molecular-weight soluble dietary fibre (SDF), and insoluble dietary fibre (IDF) were analysed. Results show that the DF content varies considerably among the 29 investigated vegetable varieties and species, but the influence of steaming is limited to a shift from IDF to high-molecular-weight SDF for 18 of the 29 tested vegetables, while fructans are preserved with not actual reduction in the DP.

Synergistic Effect of Bioactive Anticarcinogens from Soybean on Anti-Proliferative Activity in MDA-MB-231 and MCF-7 Human Breast Cancer Cells In Vitro.

Consumption of soybean products has been implicated in the prevention of breast cancer. This study provides insights into the anti-proliferative activity of 12 anticarcinogens from soybean by single or two-way combination treatment against MCF-7 and MDA-MB-231 human breast cancer cells. Results showed that genistein, daidzein, glycitein, genistin and dainzin showed stronger anti-proliferative activity against MCF-7 cells with EC50 values of 66.98 ± 4.87 µM, 130.14 ± 2.10 µM, 190.67 ± 5.65 µM, 72.82 ± 2.66 µM and 179.21 ± 6.37 µM, respectively. There is a synergistic effect of combination treatment of genistin plus daidzin in MCF-7 cells with combination index at inhibition of 50% (CI50) of 0.89 ± 0.12. Genistein, glycitein, genistin and ß-sitosterol were demonstrated to have a stronger anti-proliferative activity against MDA-MB-231 cells with EC50 values of 93.75 ± 5.15 µM, 142.67 ± 5.88 µM, 127.82 ± 4.70 µM and 196.28 ± 4.45 µM. The synergistic effect was observed in the mixture of genistein plus genistin, genistein plus ß-sitosterol or ß-sitosterol plus genistin with CI50 values of 0.56 ± 0.13, 0.54 ± 0.20 and 0.45 ± 0.12, respectively. These bioactive anticarcinogens were able to inhibit invasion and migration of breast cancer cells and the combination treatments enhanced the inhibitory effect. Regulation of PI3K/Akt/mTORpathway seems to be the main mechanisms involved in the anticancer activity.

Effects of inulin supplementation to piglets in the suckling period on growth performance, postileal microbial and immunological traits in the suckling period and three weeks after weaning.

The aim of this study was to investigate the effect of inulin (IN) supplementation to suckling piglets at and 3 weeks post-weaning. A total of 72 newborn piglets were used. Twenty-four piglets per group received different amounts of IN during the suckling period: (a) CON: no IN; (b) IN-0.5: 0.5 g IN/d on the 1st week, 1 g IN/d on the 2nd week, 1.5 g IN/d on the 3rd week and 2 g IN/d on the 4th week, or (c) IN-0.75: 0.75 g IN/d on the 1st week, 1.5 g IN/d on the 2nd week, 2.25 g IN/d on the 3rd week and 3 g IN/d on the 4th week. Starting at 28 d of age, piglets were weaned and received a post-weaning diet without inulin during the following 3 weeks. At both 28 d and 49 d of age, piglets were euthanised for sampling. Piglets of group IN-0.5 had the highest body weight starting from the 3rd week (p < 0.05), concomitant with the highest villus height and the ratio of villus height/crypt depth in the jejunum and ileum on both sampling days (p < 0.05). At 28 d of age, an increased concentration of propionate, iso-butyrate or total short chain fatty acids was observed between treatment IN-0.5 and the other groups in the caecum or colon (p < 0.05). Moreover, the relative abundance of Escherichia coli (p = 0.05) and Enterobacteriaceae (p = 0.01) in colonic digesta were reduced in IN-0.5-treated piglets, and in both IN-supplemented groups, colonic interleukin-8, tumor necrosis factor-α and toll-like receptor-4 mRNA abundance were decreased compared to the CON group (p < 0.05). However, at 49 d of age, most of these differences disappeared. In conclusion, treatment IN-0.5 improved during the suckling period of piglets development of intestine, but these beneficial effects were not lasting after weaning, when IN supplementation was terminated. Treatment IN-0.75, however, did not display a prebiotic effect.

Alpha-lipoic acid impairs body weight gain of young broiler chicks via modulating peripheral AMPK.

In mammals, the AMP-activated protein kinase (AMPK) pathways in the central and peripheral tissues coordinately integrate inputs from multiple sources to regulate energy balance. The present study was aimed to explore the potential role of hepatic AMPK in the energy homeostasis of broiler chickens. Diets with 0, 0.05% or 0.1% alpha-lipoic acid (α-LA), a known AMPK inhibitor were provided to broiler chicks for 7days. As a result, α-LA supplementation decreased the relative growth rate of broiler chicks. Hepatic AMPKα2 mRNA levels were significantly upregulated by dietary α-LA, in concert with the increased phosphorylated AMPKα protein levels. In addition, hepatic FAS mRNA levels together with the malonyl-CoA to total CoA ester ratio were reduced by α-LA supplementation. Moreover, the hepatic phosphorylated glycogen synthase levels were increased resulting in a markedly decreased hepatic glycogen content. In conclusion, dietary α-LA supplementation decreased the in vivo hepatic glycogenesis and lipogenesis via stimulating hepatic AMPKα mRNA levels and the phosphorylated gene product. The stimulatory effect of α-LA on hepatic AMPK mRNA and pAMPKα protein levels together with our previous observations regarding its inhibitory effect on hypothalamic AMPK may have altered the energy balance and hence impaired body weight gain of broiler chicks.

AMPK is involved in the differential neonatal performance of chicks hatching at different time.

We have recently reported that the hatching time may be in relation to the distinct neonatal performance of female chicks. The present study was aimed to investigate the potential involvement of AMPK, an energy sensor which plays a pivotal role in energy homeostasis, in the distinct performance of the spread of hatching time model. As a result, hypothalamic AMPKα1 isoform gene expression was significantly higher in the late hatcher as compared to that of their early counterparts, whereas the total and phosphorylated levels of AMPKα subunit did not differ between the three hatchers. The hypothalamic orexigenic NPY and AgRP mRNA levels were higher in the late hatchers as compared to the early, and that of the middle hatchers was at an intermediate level. However, the anorexigenic POMC and CRH was also higher expressed in the late hatchers as compared to the early hatchers. In the liver, AMPKα2 mRNA level and the phosphorylation ratio of AMPKα was significantly lower in the late hatchers, as compared to their early counterparts. The hepatic phosphorylated GS levels of the late and middle hatchers were lower than that of their early counterparts. The expression of hepatic FTO gene of the late hatchers was significantly higher than that of their early and middle counterparts. Taken together, AMPK may play a significant role in the different neonatal performance of the spread of hatching time model. The central and peripheral AMPK in late hatchers exhibited a pattern of higher energy intake and lower energy expenditure, which resulted in a faster post-hatch growth.

The effect of insulin on plasma glucose concentrations, expression of hepatic glucose transporters and key gluconeogenic enzymes during the perinatal period in broiler chickens.

Chickens have blood glucose concentrations that are twofold higher than those observed in mammals. Moreover, the insulin sensitivity seems to decrease with postnatal age in both broiler and layer chickens. However, little is known about the response of insulin on plasma glucose concentrations and mRNA abundance of hepatic glucose transporters 1, 2, 3, 8, 9 and 12 (GLUT1, 2, 3, 8, 9 and 12) and three regulatory enzymes of the gluconeogenesis, phosphoenolpyruvate carboxykinase 1 and 2 (PCK1 and 2) or fructose-1,6-biphosphatase 1 (FBP1) in chicks during the perinatal period. In the present study, broiler embryos on embryonic day (ED)16, ED18 or newly-hatched broiler chicks were injected intravenously with bovine insulin (1µg/g body weight (BW)) to examine plasma glucose response and changes in hepatic mRNA abundance of the GLUTs, PCK1 and 2 and FBP1. Results were compared with a non-treated control group and a saline-injected sham group. Plasma glucose levels of insulin-treated ED18 embryos recovered faster from their minimum level than those of insulin-treated ED16 embryos or newly-hatched chicks. In addition, at the minimum plasma glucose level seven hours post-injection (PI), hepatic GLUT2, FBP1 and PCK2 mRNA abundance was decreased in insulin-injected embryos, compared to sham and control groups, being most pronounced when insulin injection occurred on ED16.

Reduced protein availability by albumen removal during chicken embryogenesis decreases body weight and induces hormonal changes.

NEW FINDINGS: What is the central question of this study? Prenatal protein undernutrition by albumen removal in an avian model of fetal programming leads to long-term programming effects, but when do these effects first appear and are these programming effects regulated by the same candidate genes as in mammals? What is the main finding and its importance? The present results indicate that prenatal protein undernutrition by albumen removal induces phenotypical and hormonal changes in the early posthatch period, when the mismatch between the prenatal and postnatal environment first arises, but these changes are not accompanied by an altered gene expression of the selected candidate genes. Studies of the chicken offer a unique model for investigation of the direct effects of reduced prenatal protein availability by the partial replacement of albumen with saline in eggs at embryonic day 1 (albumen-deprived group). The results were compared with mock-treated sham chicks and non-treated control chicks. Although no differences in hatch weight were found, body weight and growth were reduced in the albumen-deprived chicks until 3 weeks of age. The feed intake of the albumen-deprived chicks, however, was increased compared with the control (day 13-21) and the sham chicks (day 16-18). In the albumen-deprived chicks, the ratio of thyroxine to 3,5,3'-triiodothyronine in the plasma was increased compared with the control chicks, whereas the plasma corticosterone level was increased only at day 7 compared with both other groups. The plasma glucose concentration and glucose tolerance were not affected by treatment. Several candidate genes previously associated with effects of prenatal protein deprivation in mammals were examined in the liver of newly hatched chicks. Gene expression of glycogen synthase 2, glycogen phosphorylase 1, peroxisome proliferator-activated receptor α and γ and glucocorticoid receptor was not affected by the treatment. In conclusion, reduction of prenatal protein availability led to differences in body weight and influenced hormones involved in metabolism and growth. Gene expression of the selected candidate genes was not altered, in contrast to mammals.