Project description:Carnosine is a bioactive food component with several potential health benefits for humans due to its physiological functions. Dietary supplementation with β-alanine or L-histidine can increase the carnosine content of skeletal muscles in chickens. Dietary supplementation with β-alanine or L-histidine has produced a slow-growing chicken variety with high carnosine content in the breast meat; however, the supplementation with L-histidine alone softens the meat toughness, which may affect consumers’ willingness to buy the meat. Gene expression is a key factor that influences meat quality. Understanding the molecular mechanisms that affect carnosine content and meat toughness would allow the production of more value-added slow-growing chickens. We compared global gene expression in chicken breast muscles with differing carnosine contents and meat toughness produced through dietary supplementation with β-alanine or L-histidine. We identified differentially expressed genes involved in regulating myosin, collagen, intramuscular fat, and calpain—factors that may affect meat tenderness. Pathway enrichment analysis indicated that the insulin-related and adipocytokine signaling pathways were altered by dietary supplementation with β-alanine or L-histidine. These data will be useful for future studies on carnosine content and meat toughness in slow-growing chickens.
Project description:Feeding dams during gestation affects the development of the offspring for their entire life. The objective of the current experiment was to evaluate the changes of the transcriptome in the hypothalamus of the offspring lambs born from dams supplemented with: i) a control diet (without lipids or methionine supplementation), ii) an omega 3 fatty acid supplementation, or iii) a methionine supplementation. The supplementation took place in the last third of gestation and the hypothalamus of male and female offspring was collected after being on a fattening diet for 54 days. Hypothalamus samples were used to extract RNA and analyzed using RNA sequencing. There was an interaction due to sex and methionine supplementation. The pathways that were modified were chromatin structure, developmental processes, and organ morphology. The modification observed on these pathways could explain the sex-by-treatment interaction differences previously observed in growth. There was no sex by omega-3 fatty acid interaction on the hypothalamus transcriptome. Therefore, the sexual dimorphism observed by methionine supplementation may be regulated by the hypothalamus.
Project description:Purpose: The present study was designed to identify both differentially expressed (DE) genes in the liver tissues of fattening Merino lambs and differences in metabolites accumulated in plasma, thus trying to identify modified metabolic pathways as a consequence of milk restriction during the suckling period. Methods: Twenty-four male Merino lambs were assigned to 2 different groups (n=12 per dietary treatment). The first group (ad libitum, ADL) was kept permanently with the dams whereas the other group (restricted, RES) was milk restricted. When they reached 15 kg of live body weight, all the lambs were offered the same complete pelleted diet at the same level to ensure no differences in dry matter intake. All the lambs were slaughtered with 27 kg. For transcriptomic analysis, 4 liver samples representative from each group (8 samples in total) were selected for RNA sequencing methodology (RNA-seq). Results: 38 DE annotated genes were identified by RNA-seq, with 23 DE genes being down-regulated and 15 up-regulated in the liver of RES relative to the ADL group (P < 0.10). In general, those genes and pathways involved in protein synthesis or protease inhibitors were down-regulated in the RES group, whereas those related to proteolytic degradation were up-regultated, thus suggesting a higher catabolism of proteins in these lambs. Contrarily, RES lambs showed over-expression of xenobiotic metabolism pathways, whereas those genes related to β-oxidation of fatty acids were down expressed. Conclusions: According to the data obtained, early feed restriction during the suckling period of Merino lambs promoted long-term effects on hepatic transcriptomic profile and plasma metabolic profile wich might have modified fatty acids metabolism, catabolism of proteins and detoxification of xenobiotics, thus reducing feed efficiency of fattening period.
Project description:Cistus ladanifer L. is a common shrub endemic to the Mediterranean that is highly concentrated in condensed tannins (CT). CT form complexes with dietary protein that resist microbial degradation in the rumen, which enhances dietary protein utilization in ruminant diets. The objective of this study was to evaluate the utilization of CT in the diet of lambs on the proteomes of muscle, hepatic and adipose tissues. Twenty-four white merino ram lambs were divided in three groups (n=8) fed on different diets: control (16% crude protein - CP), reduced protein (12% CP) and reduced protein treated with CT extract. At the end of the trial, lambs were slaughtered and the longissimus lumborum muscle, hepatic and peri-renal adipose tissues sampled. A two-way approach was used for shotgun proteomic analysis: 2D-DIGE (gel-based) and nanoLC-MS (gel-free). In the muscle, control lambs had lower abundance proteins that partake in the glycolysis pathway. With dietary 12 % CP, lambs had higher abundance of Fe-carrying proteins in the hepatic tissue. Lambs with dietary CT had higher abundance of hepatic flavin reductase. In the adipose tissue, control lambs had lower abundance of fatty-acid synthase. In conclusion, CT inclusion influences specific pathways in lamb tissues.
Project description:Folic acid deficiency is common worldwide and is linked to intestinal flora imbalance. The intestinal microbial utilization of folic acid based on model animals faces the challenges of repeatability and individual variability. In this study, we built an in vitro fecal slurry culture model deficient in folic acid. We examined the effects of supplementation with different forms of folic acid (5-methyltetrahydrofolate and non-reduced folic acid) on the modulation of intestinal flora. 16S rDNA gene sequencing showed alpha diversity increased after folic acid supplementation compared to fermentation samples with folic acid deficiency. In the non-reduced folic acid (FA) group, the relative abundance of the Firmicutes phylum dropped to 56.7%, whereas in the 5-methyltetrahydrofolate (MTHF) supplementation group, it grew to 64.9%. Lactobacillus genera became more prevalent, reaching 22.8% and 30.8%, respectively. Additionally, Bifidobacterium and Pedioccus, two common probiotic bacteria, were in higher abundance. Short-chain fatty acids (SCFAs) analysis showed that supplementation with folic acid (non-reduced folic acid, 5-methyltetrahydrofolate) decreased acetic acid and increased the fermentation yield of isobutyric acid. The in vitro fecal slurry culture model developed in this study can be utilized as a human folic acid deficiency model for studying intestinal microbiota and demonstrated that both 5-methyltetrahydrofolate and non-reduced folic acid have effects on the regulation of intestinal microecology.
2024-03-01 | GSE227224 | GEO
Project description:Effects of Diets Types on Performance, Gastrointestinal Microbiome and Metabolome of Fattening Lambs
Project description:Iron is an essential metal for both animals and microbiota, and neonates and infants of humans and animals, in general, are at the risk of iron insufficient. However, excess dietary iron usually causes negative impacts on the host and microbiota. This study aimed to investigate over-loaded dietary iron supplementation on growth performance, the distribution pattern of iron in the gut lumen and the host, intestinal microbiota, and intestine gene expression profile of piglets. Sixty healthy weaning piglets were randomly assigned to six groups: fed with diets supplemented with ferrous sulfate monohydrate at the dose of 50ppm (Fe50 group), 100ppm (Fe100 group), 200ppm (Fe200 group), 500ppm (Fe500 group), and 800ppm (Fe800) for three weeks. The results indicated that increasing iron had no effects on growth performance but increased diarrheal risk and iron deposition in intestinal digesta, tissues of intestine and liver, and serum. High iron also reduced serum iron-binding capacity, apolipoprotein, and immunoglobin A. The RNA-sequencing analysis revealed that iron changed colonic gene expression profile, such as interferon gamma-signal transducer and activator of transcription 2 based anti-virus and bacteria gene network. Increasing iron also shifted cecal and colonic microbiota, such as reducing alpha diversity, Clostridiales and Lactobacillus reuteri, and increasing Lactobacillus and Lactobacillus amylovorus. Collectively, this study demonstrated that high dietary iron increased diarrheal incidence, changed intestinal immune response-associated gene expression, and shifts gut microbiota. The results would enhance our knowledge of iron effects on the gut and microbiome in piglets, and further contribute to understanding these aspects in humans.
Project description:Tumour cells adapt to nutrient deprivation in vivo, yet strategies targeting the nutrient poor microenvironment remain unexplored. We recently found, in melanoma, tumour cells often experience low glutamine levels, which induce histone hypermethylation, promote dedifferentiation, and increase resistance to BRAF inhibitors. These findings raise the possibility that increased glutamine levels can be detrimental to melanoma tumours. Here, we show that dietary glutamine supplementation significantly inhibits melanoma tumour growth, prolongs survival in transgenic mouse model, and increases sensitivity to BRAF targeted inhibitors in both melanoma xenograft and patient-derived xenograft (PDX) models. Notably, metabolomic analysis reveals that dietary uptake of glutamine effectively increases the concentration of glutamine and its downstream metabolite, αKG, in serum and tumours, without increasing biosynthetic intermediates necessary for cell proliferation. Mechanistically, we find that glutamine supplementation uniformly alters the transcriptome and suppresses expression of many melanoma-associated genes. Our data further demonstrate that increase in intra-tumoural αKG concentration, following glutamine supplementation, drives hypomethylation of H3K4me3, thereby suppressing epigenetically-activated oncogenic pathways in melanoma. Therefore, our findings provide important evidence that glutamine supplementation can serve as a potential dietary intervention to block melanoma tumour growth and sensitize tumours to targeted therapy via epigenetic reprogramming.