Effect of dietary betaine supplementation on lipogenesis gene expression and CpG methylation of lipoprotein lipase gene in broilers

Role of Vanin-1 Gene Methylation in Fat Synthesis in Goose Liver: Effects of Betaine and 5-Azacytidine Treatments

This study aimed to investigate the mediating effect of vanin-1 (VNN1) and its DNA methylation on the reduction in liver fat synthesis due to the role of betaine and 5-Azacytidine (5-AZA) in geese. Twenty-eight 35-day-old male Jiangnan white geese with similar body weight (BW) and good health conditions were randomized into four groups (seven birds per group). All the birds were housed with the same type of basal diet. The control group was treated with normal saline intraperitoneally (I.P.); the AZA group was treated I.P. with AZA (2 mg/kg); the betaine group was fed with betaine through the diet and treated I.P. with normal saline (1.2 g/kg); the AZA+betaine group was fed with betaine through the diet and treated I.P. with AZA. The results showed that the administration of AZA significantly increased serum levels of total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL), and VNN1 enzyme activity (p < 0.05); additionally, the expression levels of the molecules in various tissues were up-regulated to different extents, such as VNN1, fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC), stearoyl-CoA dehydrogenase (SCD), and sterol regulatory element binding protein (SREBP); in contrast, the treatment of betaine reduced serum TC levels and the S-adenosylmethionine/S-adenosylhomocysteine (SAM/SAH) ratio; furthermore, hepatic DNA methylation in the AZA group was decreased in terms of the VNN1 promoter region. The results demonstrated that the expression of the VNN1 gene was negatively correlated with DNA methylation. This finding verified the key role of VNN1 and its methylation in the inhibition of liver lipid synthesis by betaine and provided a novel molecular mechanism for the regulation of liver lipid metabolism.

Habitual dietary methyl donor's intake and metabolic profile in obese individuals: a cross-sectional study

Considering the role of dietary methyl donor (DMD) in numerous biochemical processes, we hypothesized that DMD could play an important role in metabolic syndrome such as hyperlipidemia, hypertension, insulin resistance, and appetite in obese individuals. This cross-sectional study was conducted on 335 obese people. We collected dietary data using a valid and reliable 147-question Food Frequency Questionnaire (FFQ). Multivariate multinomial logistic regression was used to estimate the odds ratio (OR) and 95% confidence interval (CI) for the association between dietary methyl intake and cardio-metabolic risk factors. After adjusting for confounding variables, individuals at the fourth and third quartile of DMD, were more likely to have lower low-density lipoprotein cholesterol (LDL-C) (OR = 0.968, CI = 0.943-0.994, P = 0.015 and OR = 0.978, CI = 0.957-0.998, P = 0.03 respectively) versus first quartile. Also, total cholesterol (TC) showed a significant decrease in forth quartile of DMD in model III (OR = 0.974, CI = 0.951-0.997, P = 0.029). Current results suggested that, high DMDs' consumption, significantly associated with decreased risk of cardiometabolic risk factors.

Early-life environmental effects on birds: epigenetics and microbiome as mechanisms underlying long-lasting phenotypic changes

Although the long-lasting effects of variation in early-life environment have been well documented across organisms, the underlying causal mechanisms are only recently starting to be unraveled. Yet understanding the underlying mechanisms of long-lasting effects can help us predict how organisms will respond to changing environments. Birds offer a great system in which to study developmental plasticity and its underlying mechanisms owing to the production of large external eggs and variation in developmental trajectories, combined with a long tradition of applied, physiological, ecological and evolutionary research. Epigenetic changes (such as DNA methylation) have been suggested to be a key mechanism mediating long-lasting effects of the early-life environment across taxa. More recently, changes in the early-life gut microbiome have been identified as another potential mediator of developmental plasticity. As a first step in understanding whether these mechanisms contribute to developmental plasticity in birds, this Review summarizes how changes in early-life environment (both prenatal and postnatal) influence epigenetic markers and the gut microbiome. The literature shows how both early-life biotic (such as resources and social environment) and abiotic (thermal environment and various anthropogenic stressors) factors modify epigenetic markers and the gut microbiome in birds, yet data concerning many other environmental factors are limited. The causal links of these modifications to lasting phenotypic changes are still scarce, but changes in the hypothalamic-pituitary-adrenal axis have been identified as one putative pathway. This Review identifies several knowledge gaps, including data on the long-term effects, stability of the molecular changes, and lack of diversity in the systems studied, and provides directions for future research.

Changes in Choline Metabolites and Ceramides in Response to a DASH-Style Diet in Older Adults

This feeding trial evaluated the impact of the Dietary Approaches to Stop Hypertension diet on changes in plasma choline, choline metabolites, and ceramides in obese older adults; 28 adults consumed 3oz (n = 15) or 6oz (n = 13) of beef within a standardized DASH diet for 12 weeks. Plasma choline, betaine, methionine, dimethylglycine (DMG), phosphatidylcholine (PC), lysophosphotidylcholine (LPC), sphingomyelin, trimethylamine-N-oxide (TMAO), L-carnitine, ceramide, and triglycerides were measured in fasted blood samples. Plasma LPC, sphingomyelin, and ceramide species were also quantified. In response to the study diet, with beef intake groups combined, plasma choline decreased by 9.6% (p = 0.012); DMG decreased by 10% (p = 0.042); PC decreased by 51% (p < 0.001); total LPC increased by 281% (p < 0.001); TMAO increased by 26.5% (p < 0.001); total ceramide decreased by 22.1% (p < 0.001); and triglycerides decreased by 18% (p = 0.021). All 20 LPC species measured increased (p < 0.01) with LPC 16:0 having the greatest response. Sphingomyelin 16:0, 18:0, and 18:1 increased (all p < 0.001) by 10.4%, 22.5%, and 24%, respectively. In contrast, we observed that sphingomyelin 24:0 significantly decreased by 10%. Ceramide 22:0 and 24:0 decreased by 27.6% and 10.9% (p < 0.001), respectively, and ceramide 24:1 increased by 36.8% (p = 0.013). Changes in choline and choline metabolites were in association with anthropometric and cardiometabolic outcomes. These findings show the impact of the DASH diet on choline metabolism in older adults and demonstrate the influence of diet to modify circulating LPC, sphingomyelin, and ceramide species.

Integrative analysis of transcriptome and metabolome reveals probiotic effects on cecal metabolism in broilers

BACKGROUND

Probiotics play an important role in the host and have attracted widespread attention as an alternative to antibiotics. Arbor Acres broilers were used in the present experiment and fed different doses of compound probiotics at 1, 5, and 10 g kg^-1 . The effects of compound probiotics on broiler growth performance and cecal transcriptome and metabolome were investigated.

RESULTS

We discovered 425 differentially expressed genes (DEGs; upregulated: 256; downregulated: 169) in the cecal transcriptome study. These DEGs were assigned to fat metabolic pathways, such as the peroxisome proliferator-activated receptor (PPAR) signaling pathway, according to KEGG analysis. Probiotics downregulated LPL and upregulated PPARα expression in the cecum. In metabolome analysis of the cecum of cecum, we screened 86 differential metabolites and performed KEGG enrichment analysis of these metabolites. The KEGG analysis showed that these differentially expressed metabolites were annotated to nucleotide metabolism-related pathways, such as purine metabolism. In the cecum, probiotics upregulated the content of guanine, AMP, 3'-AMP, adenylosuccinate, deoxyguanosine, and ADP-ribose, whereas they downregulated the content of 5-hydroxyisourate. Comprehensive transcriptome and metabolome analysis revealed that glycolysis, gluconeogenesis, and glycerophospholipid metabolism pathways were jointly enriched in cecum of broilers fed a probiotic-containing diet.

CONCLUSION

This study provides valuable information for studying the regulation and gene metabolism network of probiotics on cecal metabolism in broilers. © 2022 Society of Chemical Industry.

Betaine Promotes Fat Accumulation and Reduces Injury in Landes Goose Hepatocytes by Regulating Multiple Lipid Metabolism Pathways

Betaine is a well-established supplement used in livestock feeding. In our previous study, betaine was shown to result in the redistribution of body fat, a healthier steatosis phenotype, and an increased liver weight and triglyceride storage of the Landes goose liver, which is used for foie-gras production. However, these effects are not found in other species and strains, and the underlying mechanism is unclear. Here, we studied the underpinning molecular mechanisms by developing an in vitro fatty liver cell model using primary Landes goose hepatocytes and a high-glucose culture medium. Oil red-O staining, a mitochondrial membrane potential assay, and a qRT-PCR were used to quantify lipid droplet characteristics, mitochondrial β-oxidation, and fatty acid metabolism-related gene expression, respectively. Our in vitro model successfully simulated steatosis caused by overfeeding. Betaine supplementation resulted in small, well-distributed lipid droplets, consistent with previous experiments in vivo. In addition, mitochondrial membrane potential was restored, and gene expression of fatty acid synthesis genes (e.g., sterol regulatory-element binding protein, diacylglycerol acyltransferase 1 and 2) was lower after betaine supplementation. By contrast, the expression of lipid hydrolysis transfer genes (mitochondrial transfer protein and lipoprotein lipase) was higher. Overall, the results provide a scientific basis and theoretical support for the use of betaine in animal production.

Pre-hatching and post-hatching environmental factors related to epigenetic mechanisms in poultry

Epigenetic modifications are phenotypic changes unrelated to the modification of the DNA sequence. These modifications are essential for regulating cellular differentiation and organism development. In this case, epigenetics controls how the animal's genetic potential is used. The main epigenetic mechanisms are microRNA activity, DNA methylation and histone modification. The literature has repeatedly shown that environmental modulation has a significant influence on the regulation of epigenetic mechanisms in poultry. The aim of this review is to give an overview of the current state of the knowledge in poultry epigenetics in terms of issues relevant to overall poultry production and the improvement of the health status in chickens and other poultry species. One of the main differences between birds and mammals is the stage of embryonic development. The bird's embryo develops outside its mother, so an optimal environment of egg incubation before hatching is crucial for development. It is also the moment when many factors influence the activation of epigenetic mechanisms, i.e., incubation temperature, humidity, light, as well as in ovo treatments. Epigenome of the adult birds, might be modulated by: nutrition, supplementation and treatment, as well as modification of the intestinal microbiota. In addition, the activation of epigenetic mechanisms is influenced by pathogens (i.e., pathogenic bacteria, toxins, viruses and fungi) as well as, the maintenance conditions. Farm animal epigenetics is still a big challenge for scientists. This is a research area with many open questions. Modern methods of epigenetic analysis can serve both in the analysis of biological mechanisms and in the research and applied to production system, poultry health and welfare.

Changes in Plasma Choline and the Betaine-to-Choline Ratio in Response to 6-Month Lifestyle Intervention Are Associated with the Changes of Lipid Profiles and Intestinal Microbiota: The ICAAN Study

Trimethylamine N-oxide (TMAO) and its precursors, including choline, betaine, and L-carnitine, are gut microbiota-related metabolites associated with the risk of obesity. We aimed (1) to comprehensively examine whether the changes in plasma TMAO and its precursors induced by lifestyle intervention are associated with the improvements in plasma metabolic parameters; and (2) to identify the fecal microbiome profiles and nutrient intakes associated with these metabolites and metabolic index. Data from 40 participants (obese children and adolescents) having the plasma metabolites data related to the changes in BMI z-scores after 6-month lifestyle intervention were analyzed. In this study, we observed that choline and the betaine-to-choline ratio (B/C) showed different patterns depending on the changes in BMI z-scores by the response to lifestyle intervention. During the 6 months, an increase in choline and a decrease in B/C were observed in non-responders. We also found that changes in choline and B/C were associated with the improvements in plasma lipid levels. Individuals who showed reduced choline or increased B/C from the baseline to 6 months had a significant decrease in LDL-cholesterol over 6 months compared to those with increased choline or decreased B/C, respectively. In addition, the increase in choline or decrease in B/C was associated with the increase in plasma triglycerides. The distribution of gut microbiota belonging to the Firmicutes, such as Clostridia, Clostridiales, Peptostreptococcaceae, Romboutsia, and Romboutsia timonensis was altered to be lower during the 6 months both as choline decreased and B/C increased. Moreover, the decrease in choline and the increase in B/C were associated with reduced fat intake and increased fiber intake after the 6-month intervention. Finally, lower abundance of Romboutsia showed the association with lower LDL-cholesterol and higher intake of fiber. In summary, we demonstrated that reduced choline and increased B/C by lifestyle intervention were associated with the improvements of LDL-cholesterol and triglycerides, low-fat and high-fiber intakes, and low abundance of Firmicutes. These indicate that changes to circulating choline and B/C could predict individuals' changes in metabolic compositions in response to the lifestyle intervention.

Dietary supplementation of betaine promotes lipolysis by regulating fatty acid metabolism in geese

Supplementation of betaine in the diet appears to regulate fatty acid metabolism and decrease fat deposition. This study aims to identify the effects of dietary supplementation of betaine on zootechnical performance, fatty acid synthesis, abdominal fat deposition, and morphology. Three hundred healthy, male, one-day-old Jiangnan White geese of similar body weight were randomly divided into 5 groups, with 6 replicates per treatment and 10 geese per replicate, and given the following amounts of supplementary betaine: 0 (group A), 600 mg/kg (group B), 1,200 mg/kg (group C), 1,800 mg/kg (group D), or 2,400 mg/kg (group E). Feed intake (FI), body weight (BW), abdominal fat and sebum thickness, clinical blood parameters, hepatic enzyme activity, and abdominal fat morphology were monitored during the experiment. All geese had free access to feed and water throughout the study. Our results indicate that supplementation of betaine increased zootechnical performance at 21 and 42 d of age. The percentage of abdominal fat and sebum thickness of geese at 63 d of age decreased linearly with the addition of betaine (P < 0.05). The triglyceride (TG) and total cholesterol (TCHOL) content of serum decreased with the increased level of betaine when measured at 63 d of age (P<0.05). Hormone sensitive lipase (HSL) increased with the level of betaine (P<0.05). However, dietary betaine appeared to decrease the activity of fatty acid synthase (FAS) in the geese at 42 d and 63 d of age (P<0.05). The percentage of total area of lipid droplet decreased with the increased level of betaine supplementation. In conclusion, dietary supplementation of betaine increased lipolysis and decreased fat deposition in the finishing period of geese via reducing feed intake. However, the precise mode-of-action is yet unclear and warrants further research.

Effects of Betaine Supplementation on Markers of Metabolic Flexibility, Body Composition, and Anaerobic Performance in Active College-Age Females

Betaine (BET) has shown to be effective in improving body composition and performance, although research in women is lacking. This study investigated the effects of BET supplementation on markers of metabolic flexibility, body composition, and anaerobic performance in college females. Twenty-three active subjects with 21.8 ± 3.0 years of age, 66.6 ± 8.8 kg body mass, 1.6 ± 0.1 m height, and 23.2 ± 5.3% body fat performed a graded exercise test on a cycle ergometer consisting of 4 incremental, 3 min stages for collection of fat and carbohydrate oxidation rates. Three 10 s sprint tests were then completed against a resistance of 7.5% of body mass, separated by 2.5 min of recovery. The study comprised 3 phases: (a) pre-supplementation, (b) randomization to supplement for 2-weeks with either 2.4 g/day BET or placebo (parallel design), and (c) post-supplementation. Repeated-measures analysis of variance were conducted to determine interactions or main effects. There were no group differences for substrate oxidation rates (p > 0.05). Although body composition improved pre-post for both groups (p < 0.05), only the BET group experienced a significant increase in fat free mass (p < 0.01; ∼3%). Further, only the BET group experienced improvements to performance such as a higher mean power output during the final sprint (p = 0.02; ∼3%) and a lower RPE during the final stage of the graded exercise test (p = 0.02). Results from this study suggest BET supplementation may improve body composition and some markers of performance during exercise in collegiate women.

Roles of amino acid derivatives in the regulation of obesity

Obesity is an issue of great concern to people all over the world. It is accompanied by serious complications, leading to reduced quality of life and higher morbidity and mortality. Over the past few years, there has been an explosion in knowledge about the roles of potential therapeutic agents in obesity management. Among them, amino acid (AA) derivatives, such as taurine, glutathione (GSH), betaine, α-ketoglutarate (AKG), β-aminoisobutyric acid (BAIBA), and β-hydroxy-β-methylbutyrate (HMB), have recently gained popularity due to their beneficial effects on the promotion of weight loss and improvement in the lipid profile. The mechanisms of action of these derivatives mainly include inhibiting adipogenesis, increasing lipolysis, promoting brown/beige adipose tissue (BAT) development, and improving glucose metabolism. Therefore, this review summarizes these AA derivatives and the possible mechanisms responsible for their anti-obesity effects. Based on the current findings, these AA derivatives could be potential therapeutic agents for obesity and its related metabolic diseases.

Effects of Aleurone Supplementation on Glucose-Insulin Metabolism and Gut Microbiome in Untrained Healthy Horses

Aleurone, a layer of the bran fraction, is deemed to be responsible for the positive health effects associated with the consumption of whole-grain products. Studies on rodents, pigs, and humans report beneficial effects of aleurone in five main areas: the reduction of oxidative stress, immunomodulatory effects, modulation of energy management, digestive health, and the storage of vitamins and minerals. Our study is the first aleurone supplementation study performed in horses. The aim of this study was to investigate the effect of an increase in the dose levels of aleurone on the postprandial glucose-insulin metabolism and the gut microbiome in untrained healthy horses. Seven adult Standardbred horses were supplemented with four different dose levels of aleurone (50, 100, 200, and 400 g/day for 1 week) by using a Latin square model with a 1-week wash out in between doses. On day 7 of each supplementation week, postprandial blood glucose-insulin was measured and fecal samples were collected. 16S ribosomal RNA (rRNA) gene sequencing was performed and QIIME2 software was used for microbiome analysis. Microbial community function was assessed by using the predictive metagenome analysis tool Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) and using the Metacyc database of metabolic pathways. The relative abundancies of a pathway were analyzed by using analysis of composition of microbiomes (ANCOM) in R. There was a significant dose-dependent increase in the postprandial time to peak of glucose (p = 0.030), a significant delay in the time to peak of insulin (p = 0.025), and a significant decrease in both the insulin peak level (p = 0.049) and insulin area under the curve (AUC) (p = 0.019) with increasing dose levels of aleurone, with a consideration of 200 g being the lowest significant dose. Alpha diversity and beta diversity of the fecal microbiome showed no significant changes. Aleurone significantly decreased the relative abundance of the genera Roseburia, Shuttleworthia, Anaerostipes, Faecalibacter, and Succinovibrionaceae. The most pronounced changes in the relative abundance at phyla level were seen in Firmicutes and Verrucomicrobia (downregulation) and Bacteroidetes and Spirochaetes (upregulation). The PICRUSt analysis shows that aleurone induces a downregulation of the degradation of L-glutamate and taurine and an upregulation of the three consecutive pathways of the phospholipid membrane synthesis of the Archaea domain. The results of this study suggest a multimodal effect of aleurone on glucose-insulin metabolism, which is most likely to be caused by its effect on feed texture and subsequent digestive processing; and a synergistic effect of individual aleurone components on the glucose-insulin metabolism and microbiome composition and function.

Dietary betaine intake is associated with skeletal muscle mass change over 3 years in middle-aged adults: the Guangzhou Nutrition and Health Study

A higher dietary intake or serum concentration of betaine has been associated with greater lean body mass in middle-aged and older adults. However, it remains unknown whether betaine intake is associated with age-related loss of skeletal muscle mass (SMM). We assessed the association between dietary betaine intake and relative changes in SMM after 3 years in middle-aged adults. A total of 1242 participants aged 41-60 years from the Guangzhou Nutrition and Health Study 2011-2013 and 2014-2017 with body composition measurements by dual-energy X-ray absorptiometry were included. A face-to-face questionnaire was used to collect general baseline information. After adjustment for potential confounders, multiple linear regression found that energy-adjusted dietary betaine intake was significantly and positively associated with relative changes (i.e. percentage loss or increase) in SMM of legs, limbs and appendicular skeletal mass index (ASMI) over 3 years of follow-up (β 0·322 (se 0·157), 0·309 (se 0·142) and 0·303 (se 0·145), respectively; P < 0·05). The ANCOVA models revealed that participants in the highest betaine tertile had significantly less loss in SMM of limbs and ASMI and more increase in SMM of legs over 3 years of follow-up, compared with those in the bottom betaine tertile (all Ptrend < 0·05). In conclusion, our findings suggest that elevated higher dietary betaine intake may be associated with less loss of SMM of legs, limbs and ASMI in middle-aged adults.

Association between serum choline and betaine concentrations and longitudinal changes of body composition in community-dwelling middle-aged and older Chinese adults

Previous studies suggest that betaine and choline may be beneficial for body composition. However, no longitudinal study has been conducted to illustrate if choline and betaine have long-term effects on changes in body composition. This study aimed to prospectively investigate the association between serum choline and betaine concentrations and 3-year changes in body composition in community-dwelling Chinese adults. This present analysis used data from 1384 women and 554 men aged 40–75 years. Serum concentrations of betaine and choline at baseline were assessed using high-performance liquid chromatography-tandem mass spectrometry. Body composition parameters, i.e., muscle mass (MM), fat mass (FM), and body fat percentage (FM%) were measured using dual-energy X-ray absorptiometry at the first and the second follow-ups. After adjustment for potential cofounders, higher serum choline concentrations were associated with a lower decrease in MM in men (β = 0.022, P = 0.025) and a lower increase in FM and FM% in women with baseline choline concentrations below 21.5 μmol/L (all P for nonlinearity = 0.007); higher serum betaine concentrations were associated with a lower decline in MM and a lower increase in FM and FM% among men whose betaine concentrations were lower than 55 μmol/L (all P for nonlinearity < 0.05). These findings suggest that higher concentrations of serum choline and betaine may be associated with favorable changes in body composition profiles among men and women who have relatively low concentrations, especially in men.

Novelty Higher concentrations of serum choline and betaine were associated with favorable changes in body composition. Such favorable associations were more pronounced in men.

Dietary betaine improves egg-laying rate in hens through hypomethylation and glucocorticoid receptor-mediated activation of hepatic lipogenesis-related genes

In avian species, liver lipid metabolism plays an important role in egg laying performance. Previous studies indicate that betaine supplementation in laying hens improves egg production. However, it remains unclear if betaine improves laying performance by affecting hepatic lipid metabolism and what mechanisms are involved. We fed laying hens a 0.5% betaine-supplemented diet for 4 wks to investigate its effect on hepatic lipids metabolism in vivo and confirmed its mechanism via in vitro experiments using embryonic chicken hepatocytes. Results showed that betaine supplemented diet enhanced laying production by 4.3% compared with normal diet, accompanied with increased liver and plasma triacylglycerol concentrations (P < 0.05) in hens. Simultaneously, key genes involved in hepatic lipid synthesis, such as sterol regulatory element binding protein 1 (SREBP-1), fatty acid synthase, acetyl-CoA carboxylase, and stearoyl-CoA desaturase 1 (SCD1) were markedly upregulated at the mRNA level (P < 0.05). Western blot results showed that SREBP-1 and SCD1 protein levels were also increased (P < 0.05). Moreover, mRNA expression of main apolipoprotein components of yolk-targeted lipoproteins, apolipoprotein B (ApoB) and apolipoprotein-V1 (ApoV1), in addition to microsomal triglyceride transfer proteins, which is closely related to the synthesis and release of very-low density lipoprotein, were also markedly elevated (P < 0.05). Methylated DNA immunoprecipitation combined with PCR detects reduction of methylation levels in certain regions of the above gene promoters. Chromatin immunoprecipitation PCR assays showed increased binding of glucocorticoid receptor (GR) to SREBP1 and ApoB gene promoters. Similar results of ApoV1 gene expression were obtained from cultured hepatocytes treated with betaine. Additionally, betaine increased the expression of GR and some genes involved in methionine cycle in vitro. These results suggest that betaine supplementation could alter the expression of liver lipid synthesis and transport-related genes by modifying the methylation status and GR binding on their promoter and hence promote the synthesis and release of yolk precursor substances in the liver.

Alleviation of infectious-bursal-disease-virus-induced bursal injury by betaine is associated with DNA methylation in IL-6 and interferon regulatory factor 7 promoter

Infectious bursal disease virus (IBDV) often infects young chickens and causes severe immunosuppression and inflammatory injury. Betaine is an antiviral and anti-inflammatory ingredient that may exert functions through epigenetic regulation. However, the effects of betaine on an IBDV-induced bursal injury and their underlying mechanisms have not been investigated. In this study, betaine was supplemented to the drinking water of newly hatched commercial broilers for 3 wk. Afterward, the chickens were infected with the IBDV. After 5 D of infection, the bursal lesions were examined. The mRNA expression levels of IBDV VP2 gene, pro-inflammatory cytokines, and interferons were detected. Furthermore, the 5-methylcytosine level of the CpG island in the promoter region of IL-6 and interferon regulatory factor 7 (IRF7) were determined. The IBDV induced the depletion of lymphocytes and inflammation in the bursal follicles. IBDV infection considerably elevated the mRNA levels of VP2, IL-6, types I (IFNα and IFNβ) and II (IFNγ) interferons, and IRF7. The CpG island methylation in the promoter regions of IL-6 and IRF7 were substantially decreased after IBDV infection. Betaine administration attenuated the IBDV-induced bursal lesions. Meanwhile, the IBDV-induced mRNA expression levels of IL-6, IFNβ, and IRF7 were suppressed by betaine consumption. Furthermore, the hypomethylation effects of IBDV infection to the promoter regions of IL-6 and IRF7 genes were eliminated and relieved by betaine administration. Our results indicated that the IBDV-induced expression levels of IL-6 and IRF7 genes are associated with the suppression of methylation in the promoter region. Betaine administration through drinking water may alleviate the IBDV-induced bursal injury via epigenetic regulation.

Effect of Betaine on Reducing Body Fat-A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Animal studies have shown the beneficial effect of betaine supplementation on reducing body fat, while the data from human studies are controversial and inconsistent. The objective of the present systematic review was to investigate the effects of betaine intervention on treating obesity in humans and quantitatively evaluate the pooled effects based on randomized controlled trials with a meta-analysis. The PubMed and Scopus databases, and the Cochrane Library, were searched up to September 2019. Weighted mean differences were calculated for net changes in obesity-related indices by using a random-effects model. Publication bias was estimated using Begg’s test. Six studies with 195 participants were identified. Betaine supplementation significantly reduced the total body fat mass (−2.53 kg; 95% CI: −3.93, −0.54 kg; I² = 6.6%, P = 0.36) and body fat percentage (−2.44%; 95% CI: −4.20, −0.68%; I² = 0.0%, P = 0.44). No changes were observed regarding body weight (−0.29 kg; 95% CI: −1.48, 0.89 kg; I² = 0.00%, P = 0.99) and body mass index (−0.10 kg/m²; 95% CI: −5.13, 0.31 kg/m²; I² = 0.00%, P = 0.84). The results suggested that dietary betaine supplementation might be an effective approach for reducing body fat.

Low serum choline and high serum betaine levels are associated with favorable components of metabolic syndrome in Newfoundland population

BACKGROUND

We investigated the relationships between serum choline and betaine levels with metabolic syndrome-related indices in the general population of Newfoundland.

METHODS

1081 adults were selected from the CODING study. Serum choline and betaine levels were measured. Major confounding factors were controlled in all analyses.

RESULTS

Partial correlation and linear regression analysis showed that serum choline levels were positively associated with systolic blood pressure (r: 0.124), serum TG levels (r: 0.132) and negatively correlated with serum glucose levels (r: -0.121) in males (p < 0.01 for all). In females, serum choline levels were positively correlated with serum TG, TC and HDL levels (r: 0.104 to 0.148, p < 0.05 for all). Serum betaine levels were negatively associated with serum TG, TC, LDL and insulin levels, and with atherogenic index and HOMA-IR index in males (r: -0.081 to -0.179, p < 0.05 for all). In females, serum betaine levels were negatively associated with serum TG, hsCRP and insulin levels, and with HOMA-IR index (r: -0.092 to -0.213, p < 0.05 for all). Moreover, subjects with serum choline levels in the highest tertile showed highest serum TG levels and systolic blood pressure in males, and highest serum lipids levels in females. Subjects with the highest serum betaine levels had the lowest serum lipids levels, atherogenic index, IR severity in males, and the lowest serum TG and hsCRP levels, and IR severity in females.

CONCLUSION

Low serum choline and high serum betaine levels are associated with favorable components of metabolic syndrome in general adults.

Effects of dietary supplementation with betaine on muscle growth, muscle amino acid contents and meat quality in Cherry Valley ducks

The effects of dietary betaine supplementation on growth performance, carcass characteristics, muscle amino acid contents, meat quality, antioxidant capacity, myogenic gene expression and mechanistic target of rapamycin (mTOR) signalling pathway in Cherry Valley ducks were evaluated. A total of 720 1-day-old Cherry Valley ducks were randomly distributed into four groups with six replicates of 30 birds for a 42-day feeding trial. Ducks were fed a basal diet supplemented with 0 (control), 250, 500 or 1,000 mg/kg betaine, respectively. Growth performance was not affected by betaine. Incremental levels of betaine linearly (p < 0.05) increased the breast muscle yield and linearly (p < 0.05) decreased the subcutaneous fat thickness and the abdominal fat yield. The contents of methionine, serine, glycine, glutamate and total non-essential amino acid in breast muscle were linearly (p < 0.05) increased by betaine supplementation. With increasing betaine levels, the drip loss and the content of malondialdehyde (MDA) were linearly (p < 0.05) decreased, and the redness of meat (linear p < 0.05), the activities of catalase (CAT) (linear p < 0.05) and total superoxide dismutase (T-SOD) (linear p < 0.05, quadratic p < 0.05) were increased. Moreover, the myogenic differentiation factor 1 (MyoD1) mRNA expression and the mTOR mRNA expression and protein phosporylation were linearly (p < 0.05) up-regulated, and the myostatin (MSTN) mRNA expression was linearly (p < 0.05) down-regulated by betaine supplementation. Overall, this study indicated that betaine supplementation did not affect the growth performance of Cherry Valley ducks, but could linearly increase some amino acid contents in breast muscle, especially glycine, and increase muscle antioxidant activity to improve meat quality. Moreover, betaine supplementation could improve the breast muscle yield by increasing MyoD1 mRNA expression, decreasing MSTN mRNA expression and regulating mTOR signalling pathway.

Betaine improves the growth performance and muscle growth of partridge shank broiler chickens via altering myogenic gene expression and insulin-like growth factor-1 signaling pathway

This study was conducted to investigate the effect of betaine on growth performance, carcass characteristics, myogenic gene expression, and insulin-like growth factor-1 (IGF-1) signaling pathway in partridge shank broiler chickens. A total of 192 one-day-old partridge shank broiler chickens were randomly divided into 4 groups with 6 replicates of 8 chickens for a 52-d feeding trial. Broilers were fed a basal diet supplemented with 0 (control), 250 (B250), 500 (B500), or 1,000 (B1000) mg/kg betaine. Compared with the control group, the B500 and B1000 groups had higher (P < 0.05) body weight gain (BWG), and the B500 group had a lower (P < 0.05) feed/gain ratio (F:G) during the whole trial period. Moreover, the B1000 group increased (P < 0.05) the breast muscle yield and decreased (P < 0.05) relative abdominal fat weight. The mRNA expression of myocyte enhancer factor 2B (MEF2B) and mechanistic target of rapamycin (mTOR) and mTOR phosporylation were higher (P < 0.05) in both breast and thigh muscles in the B500 and B1000 groups than those in the control group. The higher (P < 0.05) concentration and mRNA expression of IGF-1 were also observed in breast muscle in the B500 and B1000 groups. Additionally, the B1000 group up-regulated (P < 0.05) the mRNA level of myogenic differentiation factor 1 (MyoD1) in breast muscle and myogenin (MyoG) in thigh muscle. In conclusion, diets supplemented with 500 or 1,000 mg/kg betaine improved the growth performance of partridge shank broiler chickens during the whole trial period, and the B1000 group significantly improved the breast muscle growth. These improvements might result from increased mRNA expression of MyoD1 and MEF2B in breast muscle and MyoG and MEF2B in thigh muscle, and through alterations in IGF-1/mTOR signaling pathway.

Supplementary outcomes of betaine on economic and productive performance, some biochemical parameters, and lipoprotein lipase gene expression in finishing male broilers

Egypt's population is growing with the biggest hurdle facing the Government is to secure animal protein. Broilers provide quality protein of reasonable price. This study was conducted to investigate the outcomes of dietary organic betaine (betafin S4) on productive, epigenetic make up of lipoprotein lipase gene (LPL) promoter, some blood biochemical, and economic parameters in male broilers at finishing period. Eighty one commercial Arbor Acre Plus males, 21 days old, were randomly allocated to three groups, with three replicates each in battery cages under thermo-neutral environment till 42 days. The examined groups received yellow corn-soy basal diet, supplemented with 0 (G1), 1.5 (G2) and 3.0 g (G3) betaine/kg diet, respectively. The mRNA expression levels of LPL gene were analyzed by real-time quantitative PCR. Methylation pattern on LPL gene promoter was determined by bisulfite sequencing. Doses of betaine statistically (P ≤ .05) improved tested performance parameters; while carcass yield % and abdominal fat deposition did not achieve significant changes. The expression of LPL mRNA showed an inverse relationship with betaine dose, which illustrated as a trend toward increase in G2 and decrease in G3. Regarding serum biochemistry, both treated groups when compared to control group revealed a significant improvement (P ≤ .01) in albumin level, simultaneously, a significant increase (P ≤ .05) was recorded in uric acid and triglyceride levels, additionally, strong positive (P ≤ .01) correlation between betaine dose and previously mentioned parameters was reported. Betaine is recommended in finishing male broilers as production costs were reduced by 3.97%-4.37% per kg, respectively. In conclusion, incorporation of 0.15-0.30% organic betaine to male broilers diets during finishing period improves the growth performances.

Maternal Choline and Betaine Supplementation Modifies the Placental Response to Hyperglycemia in Mice and Human Trophoblasts

Gestational diabetes mellitus (GDM) is characterized by excessive placental fat and glucose transport, resulting in fetal overgrowth. Earlier we demonstrated that maternal choline supplementation normalizes fetal growth in GDM mice at mid-gestation. In this study, we further assess how choline and its oxidation product betaine influence determinants of placental nutrient transport in GDM mice and human trophoblasts. C57BL/6J mice were fed a high-fat (HF) diet 4 weeks prior to and during pregnancy to induce GDM or fed a control normal fat (NF) diet. The HF mice also received 25 mM choline, 85 mM betaine, or control drinking water. We observed that GDM mice had an expanded placental junctional zone with an increased area of glycogen cells, while the thickness of the placental labyrinth zone was decreased at E17.5 compared to NF control mice (p < 0.05). Choline and betaine supplementation alleviated these morphological changes in GDM placentas. In parallel, both choline and betaine supplementation significantly reduced glucose accretion (p < 0.05) in in vitro assays where the human choriocarcinoma BeWo cells were cultured in high (35.5 mM) or normal (5.5 mM) glucose conditions. Expression of angiogenic genes was minimally altered by choline or betaine supplementation in either model. In conclusion, both choline and betaine modified some but not all determinants of placental transport in response to hyperglycemia in mouse and in vitro human cell line models.

Metabolite and gene expression profiles suggest a putative mechanism through which high dietary carbohydrates reduce the content of hepatic betaine in Megalobrama amblycephala

BACKGROUND

High-carbohydrate diets (HCD) are favoured by the aquaculture industry for economic reasons, but they can produce negative impacts on growth and induce hepatic steatosis. We hypothesised that the mechanism behind this is the reduction of hepatic betaine content.

OBJECTIVE

We further explored this mechanism by supplementing betaine (1%) to the diet of a farmed fish Megalobrama amblycephala.

METHODS

Four diet groups were designed: control (CD, 27.11% carbohydrates), high-carbohydrate (HCD, 36.75% carbohydrates), long-term betaine (LBD, 35.64% carbohydrates) and short-term betaine diet (SBD; 12 weeks HCD + 4 weeks LBD). We analysed growth performance, body composition, liver condition, and expression of genes and profiles of metabolites associated with betaine metabolism.

RESULTS

HCD resulted in poorer growth and liver health (compared to CD), whereas LBD improved these parameters (compared to HCD). HCD induced the expression of genes associated with glucose, serine and cystathionine metabolisms, and (non-significantly, p = .20) a betaine-catabolizing enzyme betaine-homocysteine-methyltransferase; and decreased the content of betaine, methionine, S-adenosylhomocysteine and carnitine. Betaine supplementation (LBD) reversed these patterns, and elevated betaine-homocysteine-methyltransferase, S-adenosylmethionine and S-adenosylhomocysteine (all p ≤ .05).

CONCLUSION

We hypothesise that HCD reduced the content of hepatic betaine by enhancing the activity of metabolic pathways from glucose to homocysteine, reflected in increased glycolysis, serine metabolism, cystathionine metabolism and homocysteine remethylation. Long-term dietary betaine supplementation improved the negative impacts of HCD, inculding growth parameters, body composition, liver condition, and betaine metabolism. However, betaine supplementation may have caused a temporary disruption in the metabolic homeostasis.

Factors affecting adipose tissue development in chickens: A review

The intense genetic selection for rapid growth in broilers has resulted in an increase in voluntary feed intake and growth rate, accompanied by increased fat deposition in adipose tissue depots throughout the body. Adipose tissue expansion is a result of the formation of adipocytes (several processes collectively referred to as adipogenesis) and cellular accumulation of triacylglycerols inside lipid droplets. In mammals, different anatomical depots are metabolically distinct. The molecular and cellular mechanisms underlying adipose tissue development have been characterized in mammalian models, whereas information in avian species is scarce. The purpose of this review is to describe factors regulating adipogenesis in chickens, with an emphasis on dietary factors and the broiler. Results from many studies have demonstrated effects of dietary nutrient composition on adipose tissue development and lipid metabolism. Transcription factors, such as peroxisome proliferator-activated receptor γ, CCAAT/enhancer-binding proteins α and β, and sterol regulatory element binding proteins orchestrate a series of cellular events that lead to an increase in activity of fatty acid transport proteins and enzymes that are responsible for triacylglycerol synthesis. Understanding the mechanisms underlying adipose tissue development may provide a practical strategy to affect body composition of the commercial broiler while providing insights on diets that maximize conversion into muscle rather than fat and affect depot-dependent deposition of lipids. Because of the propensity to overeat and become obese, the broiler chicken also represents an attractive biomedical model for eating disorders and obesity in humans.

Higher serum choline and betaine levels are associated with better body composition in male but not female population

Background

Animal studies proved that choline and betaine have beneficial effect on reducing body fat. However, evidence in humans is scarce. We aim to investigate the association between serum choline and betaine levels with body composition in general population.

Methods

This is an observational cross-sectional study performed in 1081 subjects from the CODING (Complex Disease in Newfoundland population: Environment and Genetics) study. Serum choline and betaine levels were measured based on liquid chromatography coupled with tandem mass spectrometry technology. Body composition was measured using dual-energy X-ray absorptiometry following a 12-hour fast. Major confounding factors including age, sex, total calorie intake and physical activity level were controlled in all analyses.

Results

Significantly inverse correlations were found between serum betaine levels and all obesity measurements in males (r ranged from -0.12 to -0.23, and p<0.01 for all) but not in females. Serum choline was negatively associated with total percent body fat (%BF), percent trunk fat (%TF), weight, body mass index (BMI), waist circumference (WC), and waist-to-hip ratio (r ranged from -0.11 to -0.19, and p<0.05 for all) in males and positively associated with weight, BMI and WC (r ranged from 0.09 to 0.10, and p<0.05 for all) in females. The negative associations between serum choline and betaine levels with obesity in males were more profound in those not on any medication than those taking medications. Moreover, obese males had the lowest serum choline and betaine levels, followed by overweight males, and normal weight males having the highest serum choline and betaine levels, especially in those not taking medications (p<0.05). Likewise, subjects with the highest serum levels of both had the lowest obesity indexes, especially those not taking medications.

Conclusions

Higher serum choline and betaine levels were associated with a more favorable body composition (lower body fat and higher lean body mass) in males and the favorable association was more pronounced in non-medication users.

Higher Dietary Choline and Betaine Intakes Are Associated with Better Body Composition in the Adult Population of Newfoundland, Canada

Background

Choline is an essential nutrient and betaine is an osmolyte and methyl donor. Both are important to maintain health including adequate lipid metabolism. Supplementation of dietary choline and betaine increase muscle mass and reduce body fat in animals. However, little data is available regarding the role of dietary choline and betaine on body composition in humans.

Objective

To investigate the association between dietary choline and betaine intakes with body composition in a large population based cross-sectional study.

Design

A total of 3214 subjects from the CODING (Complex Disease in Newfoundland population: Environment and Genetics) study were assessed. Dietary choline and betaine intakes were computed from the Willett Food Frequency questionnaire. Body composition was measured using dual-energy X-ray absorptiometry following a 12-hour fast. Major confounding factors including age, sex, total calorie intake and physical activity level were controlled in all analyses.

Result

Significantly inverse correlations were found between dietary choline and betaine intakes, with all obesity measurements: total percent body fat (%BF), percent trunk fat (%TF), percent android fat (%AF), percent gynoid fat (%GF) and anthropometrics: weight, body mass index, waist circumference, waist-to-hip ratio in both women and men (r range from -0.13 to -0.47 for choline and -0.09 to -0.26 for betaine, p<0.001 for all). Dietary choline intake had stronger association than betaine. Moreover, obese subjects had the lowest dietary choline and betaine intakes, with overweight subjects in the middle, and normal weight subjects consumed the highest dietary choline and betaine (p<0.001). Vice versa, when subjects were ranked according to dietary choline and betaine intakes, subjects with the highest intake of both had the lowest %TF, %AF, %GF, %BF and highest %LM among the groups in both sexes.

Conclusion

Our findings indicate that high dietary choline and betaine intakes are significantly associated with favorable body composition in humans.

Serum betaine is inversely associated with low lean mass mainly in men in a Chinese middle-aged and elderly community-dwelling population

Previous studies have demonstrated that betaine supplements increase lean body mass in livestock and improve muscle performance in human beings, but evidence for its effect on human lean mass is limited. Our study assessed the association of circulating betaine with lean mass and its composition in Chinese adults. A community-based study was conducted on 1996 Guangzhou residents (weight/mass: 1381/615) aged 50–75 years between 2008 and 2010. An interviewer-administered questionnaire was used to collect general baseline information. Fasting serum betaine was assessed using HPLC-MS. A total of 1590 participants completed the body composition analysis performed using dual-energy X-ray absorptiometry during a mean of 3·2 years of follow-up. After adjustment for age, regression analyses demonstrated a positive association of serum betaine with percentage of lean mass (LM%) of the entire body, trunk and limbs in men (all P<0·05) and LM% of the trunk in women (P=0·016). Each sd increase in serum betaine was associated with increases in LM% of 0·609 (whole body), 0·811 (trunk), 0·422 (limbs), 0·632 (arms) and 0·346 (legs) in men and 0·350 (trunk) in women. Multiple logistic regression analysis revealed that the prevalence of lower LM% decreased by 17 % (whole body) and 14 % (trunk) in women and 23 % (whole body), 28 % (trunk), 22 % (arms) and 26 % (percentage skeletal muscle index) in men with each sd increment in serum betaine. Elevated circulating betaine was associated with a higher LM% and lower prevalence of lower LM% in middle-aged and elderly Chinese adults, particularly men.

Increased fatty acid β-oxidation as a possible mechanism for fat-reducing effect of betaine in broilers

Two hundred and forty 1-day-old male Arbor Acres broiler chickens were randomly assigned to five dietary treatments with six replicates of eight chickens per replicate cage for a 42-day feeding trial. Broiler chickens were fed a basal diet supplemented with 0 (control), 250, 500, 750 or 1000 mg/kg betaine, respectively. Growth performance was not affected by betaine. Incremental levels of betaine decreased the absolute and relative weight of abdominal fat (linear P < 0.05, quadratic P < 0.01), low-density lipoprotein cholesterol (LDL-C), triglyceride (TG) and total cholesterol (TC) (linear P < 0.05), and increased concentration of nonesterified fatty acid (NEFA) (linear P = 0.038, quadratic P = 0.003) in serum of broilers. Moreover, incremental levels of betaine increased linearly (P < 0.05) the proliferator-activated receptor alpha (PPARα), the carnitine palmitoyl transferase-I (CPT-I) and 3-hydroxyacyl-coenzyme A dehydrogenase (HADH) messenger RNA (mRNA) expression, but decreased linearly (P < 0.05) the fatty acid synthase (FAS) and 3-hydroxyl-3-methylglutaryl-CoA (HMGR) mRNA expression in liver of broilers. In conclusion, this study indicated that betaine supplementation did not affect growth performance of broilers, but was effective in reducing abdominal fat deposition in a dose-dependent manner, which was probably caused by combinations of a decrease in fatty acid synthesis and an increase in β-oxidation.

Feeding conditions and breed affect the level of DNA methylation of the mitochondrial uncoupling protein 3 gene in chicken breast muscle

To investigate the effects of feed condition and breed on the level of DNA methylation for the uncoupling protein 3 (UCP3) gene, which is an important candidate gene for regulating intramuscular fat (IMF) content in chicken breast muscle, breast muscle of Daninghe (DNH) and Qingjiaoma (QJM) chickens under scatter-feed and captivity-feed conditions was analyzed. Using RNA sequencing, 47 and 113 candidate genes were determined to be related to feed conditions and breed, respectively, and 7 differentially expressed genes were confirmed by real-time quantitative PCR, including UCP3. The mRNA levels of UCP3 were significantly different between the 2 feed conditions. The DNA region from bp +1700 to +2459 of the UCP3 gene was studied using the bisulfite sequencing method and contained 46 methylation sites and 3 CpG islands. The results showed that the methylation level of this UCP3 region was lower in DNH chickens (0.77% to 0.88%, P = 0.012) and QJM chickens (0.88% to 0.91%, P = 0.20) under scatter-feed conditions than under captivity-feed conditions. The mean methylation level of UCP3 in DNH chickens was lower than that in QJM chickens under scatter-feed conditions (DNH to QJM, 0.77% to 0.88%, P = 0.007), which suggests that breed affects the mean methylation level of UCP3 under scatter-feed conditions. In summary, our findings suggest that feed condition and breed affect the methylation of UCP3 in chicken breast muscle.

Maternal Betaine Supplementation during Gestation Enhances Expression of mtDNA-Encoded Genes through D-Loop DNA Hypomethylation in the Skeletal Muscle of Newborn Piglets

Betaine has been widely used in animal and human nutrition to promote muscle growth and performance, yet it remains unknown whether maternal betaine supplementation during gestation affects the metabolic characteristics of neonatal skeletal muscles. In the present study, feeding sows with betaine-supplemented diets throughout gestation significantly upregulated the expression of mtDNA-encoded OXPHOS genes (p < 0.05), including COX1, COX2, and ND5, in the muscle of newborn piglets, which was associated with enhanced mitochondrial COX enzyme activity (p < 0.05). Concurrently, maternal betaine supplementation increased the plasma betaine concentration and muscle expression of methyl transfer enzymes (p < 0.05), BHMT and GNMT, in offspring piglets. Nevertheless, Dnmt3a was downregulated at the level of both mRNA and protein, which was associated with a hypomethylated mtDNA D-loop region (p < 0.05). These results suggest that maternal betaine supplementation during gestation enhances expression of mtDNA-encoded genes through D-loop DNA hypomethylation in the skeletal muscle of newborn piglets.

Deciphering the therapeutic mechanisms of Xiao-Ke-An in treatment of type 2 diabetes in mice by a Fangjiomics approach

AIM

Xiao-Ke-An (XKA) is a traditional Chinese medicine (TCM) formula for the treatment of type 2 diabetes (T2D), and the effective ingredients and their targets as well as the mechanisms of XKA remain to be elucidated. In this study we investigated the therapeutic mechanisms of XKA in the treatment of T2D in mice using a Fangjiomics approach.

METHODS

KKAy mice feeding on a high-fat diet were used as models of T2D, and were orally treated with XKA (0.75 or 1.5 g · kg(-1) · d(-1)) for 32 d. Microarray mRNA expression data were obtained from the livers of the mice. Differentially expressed genes (DEGs) were identified by reverse rate analysis and ANOVA analysis. The compounds in XKA were identified by LC-MS analysis or collected from TCM databases. The relationships between the compounds and targets were established by combining the DEGs with information derived from mining literature or herb target databases. Relevant pathways were identified through a Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis using WebGestalt.

RESULTS

The compound-target-pathway network based on compounds identified by LC-MS analysis (NCA) included 20 constituent compounds, 46 targets and 36 T2D-related pathways, whereas the compound-target-pathway network based on compounds collected from databases (NCD) consisted of 40 compounds, 68 targets and 21 pathways. In the treatment of T2D, XKA might act mainly by improving carbohydrate and lipid metabolism, as well as ameliorating insulin resistance, inflammation and diabetic vascular complications.

CONCLUSION

The network-based approach reveals complex therapeutic mechanisms of XKA in the treatment of T2D in mice that involve numerous compounds, targets, and signaling pathways.

Folate supplementation modifies CCAAT/enhancer-binding protein α methylation to mediate differentiation of preadipocytes in chickens

Folate, an essential vitamin participating in 1-carbon metabolism leading to a methyl donor function, is a key factor inducing epigenetic changes. This study sought to determine if folate influences the methylation level of cytosine-guanine (CpG) islands in the promoters of critical adipogenic genes in chickens, and how this might affect gene expression and differentiation of preadipocytes in vitro. Preadipocytes were treated with 0 to 16 mg/L of folate during the induction of differentiation, and cell proliferation and lipid accumulation were assessed. The folate supplementation resulted in enhanced cell proliferation and decreased content of lipid per adipocyte at d 6 of differentiation. The effects of folate on relative expression of genes critical for adipocyte differentiation and 1-carbon metabolism were measured by quantitative reverse-transcription PCR. Folate caused a dose-dependent decrease in transcript abundance of peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer-binding protein α (C/EBPα) gene expression, and the downstream enzyme fatty acid synthase; in contrast, expression of DNA (cytosine-5)-methyltransferase and methylenetetrahydrofolate reductase was obviously upregulated at d 6 of differentiation (P < 0.05). The DNA methylation was examined with the bisulfite sequencing PCR method. Overall CpG methylation in the C/EBPα gene promoter region was 21.8% lower (P < 0.05) and the gene's expression was 2.7-fold higher in the absence of folate, compared with cells treated with 16 mg/L of folate, whereas methylation of the PPARγ promoter was not affected. Overall, the results show that folate increased the proliferation of adipocytes but reduced per-cell lipid accumulation, thereby influencing differentiation; it increased expression of genes involved in 1-carbon metabolism resulting in greater methylation of the C/EBPα promoter during differentiation and decreased that gene's expression, perhaps accounting for decreased expression of PPARγ.

Nutritional factors affecting abdominal fat deposition in poultry: a review

The major goals of the poultry industry are to increase the carcass yield and to reduce carcass fatness, mainly the abdominal fat pad. The increase in poultry meat consumption has guided the selection process toward fast-growing broilers with a reduced feed conversion ratio. Intensive selection has led to great improvements in economic traits such as body weight gain, feed efficiency, and breast yield to meet the demands of consumers, but modern commercial chickens exhibit excessive fat accumulation in the abdomen area. However, dietary composition and feeding strategies may offer practical and efficient solutions for reducing body fat deposition in modern poultry strains. Thus, the regulation of lipid metabolism to reduce the abdominal fat content based on dietary composition and feeding strategy, as well as elucidating their effects on the key enzymes associated with lipid metabolism, could facilitate the production of lean meat and help to understand the fat-lowering effects of diet and different feeding strategies.

Nutrition and epigenetics: an interplay of dietary methyl donors, one-carbon metabolism and DNA methylation

DNA methylation is the most extensively studied mechanism of epigenetic gene regulation. Increasing evidence indicates that DNA methylation is labile in response to nutritional and environmental influences. Alterations in DNA methylation profiles can lead to changes in gene expression, resulting in diverse phenotypes with the potential for increased disease risk. The primary methyl donor for DNA methylation is S-adenosylmethionine (SAM), a species generated in the cyclical cellular process called one-carbon metabolism. One-carbon metabolism is catalyzed by several enzymes in the presence of dietary micronutrients, including folate, choline, betaine and other B vitamins. For this reason, nutrition status, particularly micronutrient intake, has been a focal point when investigating epigenetic mechanisms. Although animal evidence linking nutrition and DNA methylation is fairly extensive, epidemiological evidence is less comprehensive. This review serves to integrate studies of the animal in vivo with human epidemiological data pertaining to nutritional regulation of DNA methylation and to further identify areas in which current knowledge is limited.

The expression levels of DNMT3a/3b and their relationship with meat quality in beef cattle

To identify the effects of the expression levels of DNMT3a and DNMT3b, coding the de novo methyltransferases DNMT3a and DNMT3b, on 16 beef carcass and quality traits, 50 beef cattle liver and ribeye muscle tissue samples were collected. Quantitative real-time RT-PCR was employed to quantify the expression level of these two genes, and a basic model included fixed effects of gender, age, and expression level of these two genes was used to analyze live weight; and slaughtering batches and aging days were added when beef carcass traits and beef quality traits were analyzed, respectively. Results showed that transcripts of DNMT3a and DNMT3b were present at significantly higher levels in liver tissue than in muscle tissue, and the expression level of DNMT3a was significantly higher than that of DNMT3b in both tissues. Regression analysis found that the expression levels of DNMT3a and DNMT3b were associated with several beef quality traits, which are important in beef breeding. Findings of the present study suggested that these two genes could significantly contribute to the improvement of beef quality genetically.

Association of A-FABP gene polymorphism in intron 1 with meat quality traits in Junmu No. 1 white swine

This study was designed to investigate the single nucleotide polymorphism (SNP) in intron 1 of the gene A-FABP in 127 Junmu No. 1 white swine using PCR-SSCP. The association between the polymorphism and meat quality traits was also studied. The cloning and sequencing results indicated that the polymorphism of intron 1 was due to a point mutation in position 3481bp of A-FABP, giving 3 genotypes (CC, CD and DD). Association analysis indicated that the polymorphism had a significant effect on marbling (P<0.05). Genotype DD had higher marbling than CD and CC, but the difference between CD and CC was no significant. Polymorphism had a highly significant effect on intramuscular fat (IMF) content (P<0.01). DD was higher than CD, which was higher than CC. No significant conclusions can be drawn regarding other traits. Immunoblot analysis of A-FABP levels was carried out on 3 different genotype individuals. Expression was markedly reduced in DD compared with genotype CC. Thus A-FABP may be a candidate gene or a quantitative trait locus-linked gene associated with meat quality traits.