Dietary betaine supplementation in hens modulates hypothalamic expression of cholesterol metabolic genes in F1 cockerels through modification of DNA methylation

Modulation of gene expression in immune-related organs by in ovo stimulation with probiotics and prophybiotics in broiler chickens

In ovo stimulation has been studied intensively as an alternative to antibiotic use in poultry production. We investigated the potential use of a probiotic in combination with a phytobiotic as a prophybiotic for in ovo stimulation and reported its beneficial effects on the gut microbiome of broiler chickens. The current study further investigates the gene expression in the immune-related organs of these chickens to understand the tissue-specific immunomodulatory effects of the treatments. The selected prophybiotic (Leuconostoc mesenteroides with garlic aqueous extract) and its probiotic component alone were injected into ROSS308 chicken eggs on the 12th day of incubation, and gene expression in cecal tonsils, spleen, and liver at 35 days of age was determined using qPCR method. The relative expression of each treatment was compared to the positive control, chickens injected with physiological saline in ovo. The results displayed a downregulation of pro- and anti-inflammatory cytokines in the cecal tonsils of the probiotic group and the liver of the prophybiotic group. The spleen displayed upregulated AVBD1 in both groups and upregulated IL1-β in the probiotic group. The probiotic group displayed increased expression of genes related to metabolism of energy (COX16), protein (mTOR), and lipids (CYP46A1) whereas the prophybiotic group displayed reduced expression of genes related to cholesterol synthesis (SREBP1) and glucose transportation (SLC2A2) in the liver. In conclusion, Leuconostoc mesenteroides differentially modulated gene expression in chickens when administered in ovo in combination with garlic aqueous extract. Further in ovo studies with different prophybiotic combinations are required to optimize the benefits in broiler chickens.

Unravelling the impact of epigenetic mechanisms on offspring growth, production, reproduction and disease susceptibility

Epigenetic mechanisms, such as DNA methylation, histone modifications and non-coding RNA molecules, play a critical role in gene expression and regulation in livestock species, influencing development, reproduction and disease resistance. DNA methylation patterns silence gene expression by blocking transcription factor binding, while histone modifications alter chromatin structure and affect DNA accessibility. Livestock-specific histone modifications contribute to gene expression and genome stability. Non-coding RNAs, including miRNAs, piRNAs, siRNAs, snoRNAs, lncRNAs and circRNAs, regulate gene expression post-transcriptionally. Transgenerational epigenetic inheritance occurs in livestock, with environmental factors impacting epigenetic modifications and phenotypic traits across generations. Epigenetic regulation revealed significant effect on gene expression profiling that can be exploited for various targeted traits like muscle hypertrophy, puberty onset, growth, metabolism, disease resistance and milk production in livestock and poultry breeds. Epigenetic regulation of imprinted genes affects cattle growth and metabolism while epigenetic modifications play a role in disease resistance and mastitis in dairy cattle, as well as milk protein gene regulation during lactation. Nutri-epigenomics research also reveals the influence of maternal nutrition on offspring's epigenetic regulation of metabolic homeostasis in cattle, sheep, goat and poultry. Integrating cyto-genomics approaches enhances understanding of epigenetic mechanisms in livestock breeding, providing insights into chromosomal structure, rearrangements and their impact on gene regulation and phenotypic traits. This review presents potential research areas to enhance production potential and deepen our understanding of epigenetic changes in livestock, offering opportunities for genetic improvement, reproductive management, disease control and milk production in diverse livestock species.

Low Dietary Betaine Intake Is Associated with Increased Blood Cholesterol in Mexican Subjects

BACKGROUND

Betaine, an osmolyte derivative of the metabolite choline and the amino acid glycine, acts as a methyl donor in the conversion of homocysteine to methionine and is involved in the maintenance of adequate lipid metabolism. There is growing evidence for the role of betaine in the development of various lipid-related diseases, including dyslipidemia and cardiovascular risk. This study aimed to analyze associations between betaine intake and blood lipid profiles in Mexican subjects.

METHODS

A total of 212 adults were randomly recruited in the city of Tijuana, Baja California, Mexico. Betaine intake was estimated using Nutritionist Pro software. Body composition and metabolic measurements were obtained by conventional methods. In the total sample, the average intake of betaine was 14.32 mg/d. Individuals were categorized into three groups according to tertiles of betaine consumption: tertile/group 1 (<4.16 mg/d), tertile/group 2 (4.16-12.02 mg/d), and tertile/group 3 (>12.02 mg/d).

RESULTS

Compared to group 3, subjects within group 1 had higher serum levels of total cholesterol (p = 0.001), LDL-c (p = 0.026), and non-HDL-c (p = 0.021). In addition, significant negative Pearson correlations were found between betaine intake and the serum levels of total cholesterol (r = -0.432, 95% CI, -0.684, -0.185, p = 0.001), LDL-c (r = -0.370, 95% CI, -0.606, -0.134, p = 0.002), and non-HDL-c (r = -0.351, 95%CI, -0.604, -0.098, p = 0.007).

CONCLUSIONS

Our results show that a low intake of betaine is associated with elevated blood cholesterol levels in Mexican subjects. On this basis, betaine consumption could be used as an additional dietary measure for cardiovascular care. However, additional studies are required to confirm our results in other Mexican regions as well as in other populations worldwide.

Betaine supplementation alleviates corticosterone-induced hepatic cholesterol accumulation through epigenetic modulation of HMGCR and CYP7A1 genes in laying hens

Excessive corticosterone (CORT) exposure could cause hepatic cholesterol accumulation in chickens and maternal betaine supplementation could decrease hepatic cholesterol deposition through epigenetic modifications in offspring chickens. Nevertheless, it remains uncertain whether providing betaine to laying hens could protect CORT-induced hepatic cholesterol accumulation via epigenetic mechanisms. This study aimed to examine the effects of dietary betaine on plasma and hepatic cholesterol contents, expression of cholesterol metabolic genes, as well as DNA methylation on their promoters in the liver of laying hens exposed to CORT. A total of 72 laying hens at 130 d of age were randomly divided into 3 groups: control (CON), CORT, and CORT+betaine (CORT+BET) groups. The experiment lasted for 35 d. Chickens in CON and CORT groups were fed a basal diet, whereas the CORT+BET group chickens were fed the basal diet supplemented with 0.1% betaine for 35 d. On d 28 of the experiment, chickens in CORT and CORT+BET groups received daily subcutaneous injections of CORT (4.0 mg/kg body weight), whereas the CON group chickens were injected with an equal volume of solvent for 7 d. The results showed that CORT administration led to a significant increase (P < 0.05) in the contents of cholesterol in plasma and liver, associated with activation (P < 0.05) of sterol regulatory element binding transcription factor 2 (SREBP2), 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), lecithin-cholesterol acyltransferase (LCAT) and low-density lipoprotein receptor (LDLR) genes expression, and inhibition of cholesterol-7-alpha hydroxylase (CYP7A1) and sterol 27-hydroxylase (CYP27A1) genes expression in the liver compared to the CON. In contrast, CORT-induced up-regulation of HMGCR mRNA and protein abundances and downregulation of CYP7A1 mRNA and protein abundances were completely normalized (P < 0.05) by betaine supplementation. Besides, CORT injection led to significant hypomethylation (P < 0.05) on HMGCR promoter and hypermethylation (P < 0.05) on CYP7A1 promoter. Moreover, dietary betaine rescued (P < 0.05) CORT-induced changes in methylation status of HMGCR and CYP7A1 genes promoters. These results indicate that dietary betaine addition protects laying hens from CORT-induced hepatic cholesterol accumulation via epigenetic modulation of HMGCR and CYP7A1 genes.

Effect of Dietary Betaine on Muscle Protein Deposition, Nucleic Acid and Amino Acid Contents, and Proteomes of Broilers

To investigate the effect of betaine supplementation on growth performance, muscle protein deposition, muscle nucleic acid and amino acid contents, and muscle proteome of broilers, 160 one-day-old male partridge shank broiler chickens were randomly divided into 2 groups with 8 replicates of 10 broilers each. Broilers were fed a basal diet alone, or a basal diet supplemented with 1000 mg/kg betaine. Compared with the control group, the betaine group significantly increased (p < 0.05) the broilers average daily gain, the levels of serum insulin-like growth factor-1 (IGF-1), growth hormone (GH), total protein (TP), the contents of muscle absolute protein deposition, RNA, Ser, Glu, Met, and Phe, and the ratio of RNA/DNA, and decreased (p < 0.05) the feed conversion ratio and serum blood urea nitrogen content. Moreover, proteomic analysis revealed 35 differentially abundant proteins (DAPs) in the betaine group compared with the control group, including 27 upregulated proteins and 8 downregulated proteins (p < 0.05). These DAPs were mainly related to cell differentiation, small molecule metabolic process, and tissue development. In conclusion, diets supplemented with 1000 mg/kg betaine improved growth performance and muscle protein deposition of broilers. Increased serum GH, IGF-1, and TP contents, and alterations in muscle nucleic acids, amino acids, and protein abundance levels were involved in this process.

Evaluation of the Genetic Association and Methylation of Immune Response Pathway Genes with the Risk of Chronic Periodontitis in the Uighur Population

Aim: The aim of this study was to explore the possible associations between single nucleotide polymorphisms (SNPs) and DNA methylation levels of seven genes in the inflammatory response pathway with susceptibility to chronic periodontitis (CP) among the Uighur population of the Xinjiang Autonomous Region of China. Methods: A total of 444 eligible subjects (279 CP patients and 165 healthy controls) were enrolled in the study. Genomic DNA was obtained from gingival tissue for genotyping eight SNPs and performing methylation measurements of seven genes. Results: SNP rs2070745 in the formyl peptide receptor 1 (FPR1) gene achieved statistical significance in a standard allelic association analysis for CP (p = 0.02). The frequency of the rs2070745 minor allele G was higher in the cases than in controls (0.367 vs. 0.291). Additionally, rs2070745 was significantly associated with CP under the dominant genetic model (p = 0.03). Using logistic regression analysis, rs2070745 was found to be consistently associated with CP under the additive dominant model, and this association remained significant after covariates were taken into account [odds ratio (OR) = 1.49 (1.09-2.05), p = 0.014; OR = 1.58 (1.04-2.40), p = 0.031, respectively]. No significant gene-gene interactions were identified. Although we did not find a polymorphism in interleukin 6 (IL6) associated with CP in our study, the methylation level of a CpG island region located within the promoter region of IL6 was significantly less in CP patients compared with controls (p < 0.05). Conclusions: The genetic polymorphism rs2070745 in FPR1 and the methylation level of the promoter region of IL6 might be associated with CP in the Uighur population of China.

Interaction between early-life pet exposure and methylation pattern of ADAM33 on allergic rhinitis among children aged 3-6 years in China

Background

Recent research has pointed out the important roles of epigenetic modifications in the development and persistence of allergic rhinitis (AR), especially in relation to DNA methylation of disease-associated genes. We investigated whether AR susceptibility genes were epigenetically regulated, and whether methylation modulation of these genes in response to early-life environment could be a molecular mechanism underlying the risk for AR onset in a cohort of children aged 3–6 years in China.

Methods

Peripheral blood mononuclear cell (PBMC) samples were collected from 130 children patients, aged 3–6 years and diagnosed with AR; and 154 matched controls to detect promoter methylation in 25 AR susceptibility genes with the MethylTarget approach. Methylation levels were compared for each CpG site, each amplified region, and each gene. In addition, the relationship among DNA methylation, early-life environmental risk factors and AR onset were assessed.

Results

Maternal allergic history (P = 0.0390) and pet exposure (P = 0.0339) were significantly associated with increased AR risk. Differential methylation analyses were successfully performed for 507 CpG sites, 34 amplified regions and 17 genes and significant hypomethylation was observed in the promoter region of ADAM33 in AR patients [multiple test-corrected (FDR) P-value < 0.05]. Spearman correlation analysis revealed that the hypomethylation of ADAM33 was significantly associated with higher eosinophil counts (Spearman’s ρ: − 0.187, P-value = 0.037). According to the results of the multiple regression analysis, after adjusting for cofounders, the interaction of early-life pet exposure with methylation level of ADAM33 increased the risk for AR onset 1.423 times more in children (95% CI = 0.0290–4.109, P-value = 0.005).

Conclusion

This study provides evidence that early-life pet exposure and low methylation level of ADAM33 increase AR risk in children, and the interaction between pet exposure and methylation level of ADAM33 may play an important role in the development of AR.

Impacts of Epigenetic Processes on the Health and Productivity of Livestock

The dynamic changes in the epigenome resulting from the intricate interactions of genetic and environmental factors play crucial roles in individual growth and development. Numerous studies in plants, rodents, and humans have provided evidence of the regulatory roles of epigenetic processes in health and disease. There is increasing pressure to increase livestock production in light of increasing food needs of an expanding human population and environment challenges, but there is limited related epigenetic data on livestock to complement genomic information and support advances in improvement breeding and health management. This review examines the recent discoveries on epigenetic processes due to DNA methylation, histone modification, and chromatin remodeling and their impacts on health and production traits in farm animals, including bovine, swine, sheep, goat, and poultry species. Most of the reports focused on epigenome profiling at the genome-wide or specific genic regions in response to developmental processes, environmental stressors, nutrition, and disease pathogens. The bulk of available data mainly characterized the epigenetic markers in tissues/organs or in relation to traits and detection of epigenetic regulatory mechanisms underlying livestock phenotype diversity. However, available data is inadequate to support gainful exploitation of epigenetic processes for improved animal health and productivity management. Increased research effort, which is vital to elucidate how epigenetic mechanisms affect the health and productivity of livestock, is currently limited due to several factors including lack of adequate analytical tools. In this review, we (1) summarize available evidence of the impacts of epigenetic processes on livestock production and health traits, (2) discuss the application of epigenetics data in livestock production, and (3) present gaps in livestock epigenetics research. Knowledge of the epigenetic factors influencing livestock health and productivity is vital for the management and improvement of livestock productivity.

Impact of Dietary Betaine and Metabolizable Energy Levels on Profiles of Proteins and Lipids, Bioenergetics, Peroxidation and Quality of Meat in Japanese Quail

Three different diets were formulated with three levels of metabolizable energy (ME) (optimum; 2900, restricted; 2800 and low; 2700 kcal ME/kg diet) without or with (0 and 0.15%) betaine supplementation in 2 × 3 factorial design to evaluate the effect of six experimental diets on performance, proteins and lipids profiles, bioenergetics, peroxidation and meat quality of Japanese quail. Therefore, 360 quails allocated into six groups in a 23-day experiment. Dietary betaine and ME levels did not affect the performance, meat energy indices (ATP and AMP) and malondialdehyde (MDA) levels of Japanese quail meat. Dietary betaine and/or ME levels induced significant changes in serum triacylglycerol (TAG), total cholesterols (TC), low-density lipoprotein cholesterol (LDL-c), very low-density lipoprotein cholesterol (VLDL-c), meat total lipids and cholesterol of Japanese quail. Optimum and restricted ME levels reduced total volatile basic nitrogen (TVBN) whereas dietary betaine increased ecosapentaenoic (EPA), docosahexaenoic acids (DHA) and glutamine concentrations in breast meat of Japanese quail. Dietary betaine and low energy diet improved cooking loss, thawing loss (ThL) and water holding capacity (WHC) in breast meat of Japanese quail. Conclusively, dietary betaine improved meat quality of Japanese quail fed diets containing either restricted or low ME by enrichments the meat with omega-3 fatty acids and reduction of lipids levels.

Dietary Betaine Addition Promotes Hepatic Cholesterol Synthesis, Bile Acid Conversion, and Export in Rats

It is widely reported how betaine addition regulates lipid metabolism but how betaine affects cholesterol metabolism is still unknown. This study aimed to investigate the role of betaine in hepatic cholesterol metabolism of Sprague-Dawley rats. Rats were randomly allocated to four groups and fed with a basal diet or a high-fat diet with or without 1% betaine. The experiment lasted 28 days. The results showed that dietary betaine supplementation reduced the feed intake of rats with final weight unchanged. Serum low-density-lipoprotein cholesterol was increased with the high-fat diet. The high-fat diet promoted cholesterol synthesis and excretion by enhancing the HMG-CoA reductase and ABCG5/G8, respectively, which lead to a balance of hepatic cholesterol. Rats in betaine groups showed a higher level of hepatic total cholesterol. Dietary betaine addition enhanced cholesterol synthesis as well as conversion of bile acid from cholesterol by increasing the levels of HMGCR and CYP7A1. The high-fat diet decreased the level of bile salt export pump, while dietary betaine addition inhibited this decrease and promoted bile acid efflux and increased total bile acid levels in the intestine. In summary, dietary betaine addition promoted hepatic cholesterol metabolism, including cholesterol synthesis, conversion of bile acids, and bile acid export.

Maternal betaine supplementation decreases hepatic cholesterol deposition in chicken offspring with epigenetic modulation of SREBP2 and CYP7A1 genes

Maternal betaine was reported to regulate offspring hepatic cholesterol metabolism in mammals. However, it is unclear whether and how feeding betaine to laying hens affects hepatic cholesterol metabolism in offspring chickens. Rugao yellow-feathered laying hens (n = 120) were fed basal or 0.5% betaine-supplemented diet for 28 D before the eggs were collected for incubation. Maternal betaine significantly decreased the hepatic cholesterol content (P < 0.05) in offspring chickens. Accordingly, the cholesterol biosynthetic enzymes, sterol regulator element-binding protein 2 (SREBP2) and 3-hydroxy-3-methylglutaryl coenzyme A reductase, were decreased, while cholesterol-7alpha-hydroxylase (CYP7A1), which converts cholesterol to bile acids, was increased at both mRNA and protein levels in betaine-treated offspring chickens. Hepatic mRNA and protein expression of low-density lipoprotein receptor was significantly (P < 0.05) increased, while the mRNA abundance of cholesterol acyltransferase 1 (ACAT1) that mediates cholesterol esterification was significantly (P < 0.05) decreased in the betaine group. Meanwhile, hepatic protein contents of DNA methyltransferases 1 and betaine homocysteine methyltransferase were increased (P < 0.05), which was associated with modifications of CpG methylation on affected cholesterol metabolic genes. Furthermore, the level of CpG methylation on gene promoters was increased (P < 0.05) for sterol regulator element-binding protein 2 and abundance of cholesterol acyltransferase 1 yet decreased (P < 0.05) for cholesterol-7alpha-hydroxylase. These results indicate that maternal betaine supplementation significantly decreases hepatic cholesterol deposition through epigenetic regulation of cholesterol metabolic genes in offspring juvenile chickens.

Fetal betaine exposure modulates hypothalamic expression of cholesterol metabolic genes in offspring cockerels with modification of promoter DNA methylation

In documents, maternal betaine modulates hypothalamic cholesterol metabolism in chicken posthatchings, but it remains unclear whether this effect can be passed on by generations. In present study, eggs were injected with saline or betaine at 2.5 mg/egg, and the hatchlings (F1) were raised under the same condition until sexual maturation. Both the control group and the betaine group used artificial insemination to collect sperm from their cockerels. Fertilized eggs were incubated, and the hatchlings of the following generation (F2) were raised up to 64 D of age. F2 cockerels in betaine group showed significantly (P < 0.05) lower body weight, which was associated with significantly decreased (P < 0.05) hypothalamic content of total cholesterol and cholesterol ester. Concordantly, hypothalamic expression of cholesterol biosynthetic genes, SREBP2 and HMGCR, were significantly downregulated (P < 0.05), together with cholesterol conversion-related and excretion-related genes, CYP46A1 and ABCA1. These changes coincided with a significant downregulation in mRNA expression of regulatory neuropeptides including brain-derived neurotrophic factor, neuropeptide Y, and corticotropin-releasing hormone. Moreover, genes involved in methyl transfer cycle were also modified. Betaine homocysteine methyltransferase (P < 0.05) was downregulated, yet DNA methyltransferase1 tended to be upregulated (P = 0.06). S-adenosyl methionine/S-adenosylhomocysteine ratio was higher in the hypothalamus of betaine-treated F2 cockerels, which was associated with significantly modified CpG methylation on the promoter of those affected genes. These results suggested that betaine might regulate central cholesterol metabolism and hypothalamic expression of genes related to brain function by altering promoter DNA methylation in F2 cockerels.

Components of the choline oxidation pathway modify the association between the apolipoprotein ε4 gene variant and cognitive decline in patients with dementia

BACKGROUND

Metabolites involved in one-carbon metabolism (OCM) may predict cognitive prognosis in dementia. The link between OCM, apolipoprotein E (APOE), and DNA methylation creates a biologically plausible mechanism of interaction.

AIM

To assess OCM metabolites as predictors of 5-year cognitive prognosis in patients with mild dementia, and in subgroups defined by the APOEε4 allele variant.

METHODS

We followed one-hundred and fifty-two patients with mild dementia (86 with Alzheimer's disease, 66 with Lewy body dementia, including 90 with at least one APOEε4 allele) for 5 years with annual Mini-Mental State Examinations (MMSE). Total homocysteine, methionine, choline, betaine, dimethylglycine, sarcosine, folate, cobalamin and pyridoxal 5'-phoshate were measured in serum at baseline. We used linear mixed models to assess metabolite-MMSE associations, including 3-way interactions between metabolites, time, and APOEε4. False-discovery rate adjusted p-values (Q-values) are reported.

RESULTS

Metabolite concentrations were not different in patients with dementia according to the presence of APOEε4. Overall, serum concentration of total homocysteine was inversely associated with MMSE performance, while betaine was positively associated with MMSE (Q < 0.05), but neither was associated with MMSE decline. Serum concentrations of betaine, dimethylglycine and sarcosine, however, were associated with slower MMSE decline in patients with APOEε4, but with faster MMSE decline in patients without the allele (all 3-way interactions: Q < 0.05).

CONCLUSION

Components of the choline oxidation pathway are associated with a better cognitive prognosis in APOEε4 carriers and a worse cognitive prognosis in non-carriers. Further research investigating targeted metabolic interventions according to APOE allele status is warranted.

Cellular Mechanisms and Epigenetic Changes: Role of Nutrition in Livestock

In the context of physiologic responses that determine the growth, development, and health status of livestock, the role of epigenetics and the underlying cellular mechanisms it affects remain to be fully elucidated. Although recent work has provided evidence that maternal dietary energy level, carbohydrate type, or intestinal supply of methyl donors can elicit molecular changes in tissues of the embryo, fetus, or neonate, there are few data linking epigenetics with biochemical and physiologic outcomes. Therefore, efforts linking the epigenome with physiologic and developmental outcomes offer exciting opportunities for discoveries that can impact efficiency of nutrient use and well-being of livestock.