Betaine recovers hypothalamic neural injury by inhibiting astrogliosis and inflammation in fructose-fed rats

SCOPE:: Hypothalamic astrogliosis and inflammation cause neural injury, playing a critical role in metabolic syndrome development. This study investigated whether and how fructose caused hypothalamic astrogliosis and inflammation in vivo and in vitro. The inhibitory effects of betaine on hypothalamic neural injury, astrogliosis and inflammation were explored to address its improvement of fructose-induced metabolic syndrome.
METHODS AND RESULTS:: Rats or astrocytes were exposed to fructose and then treated with betaine. Neural injury, proinflammatory markers, toll-like receptor 4/nuclear factor-kappaB (TLR4/NF-kappaB) pathway and histone deacetylases (HDAC3) expression were evaluated. The reduction of pro-opiomelanocortin (POMC) and melanocortin 4 receptor (Mc4R) neurons in fructose-fed rats were ameliorated by betaine. Moreover, fructose induced astrogliosis and proinflammatory cytokines by increasing TLR4, MyD88 and NF-kappaB expression in rat hypothalamus and astrocytes. HDAC3 over-expression preserved the prolonged inflammation in fructose-stimulated astrocytes by regulating nuclear NF-kappaB-dependent transcription. Betaine suppressed TLR4/NF-kappaB pathway activation and HDAC3 expression, contributing to its inhibition of hypothalamic astrogliosis and inflammation in animal and cell models.
CONCLUSION:: These findings suggest that betaine inhibits fructose-caused astrogliosis and inflammation by the suppression of TLR4/NF-kappaB pathway activation and HDAC3 expression to protect against hypothalamic neural injury, which, at least partly, contributes to the improvement on fructose-induced metabolic syndrome.

Li, J.M., et al., Betaine recovers hypothalamic neural injury by inhibiting astrogliosis and inflammation in fructose-fed rats. Mol Nutr Food Res, 2014

Higher serum concentrations of betaine is associated with better profiles of body fat and fat distribution in Chinese adults

Objective: Animal studies have suggested that betaine but not choline may improve body composition, but little evidence is available in humans. We examined the associations of serum concentrations of choline and betaine with body composition and fat distribution in adults.
Methods: This community-based study recruited 1996 adults (W/M: 1380/616) aged 40-75 in urban Guangzhou, China. General information and anthropometric measurements were taken, and serum choline and betaine levels were assessed by HPLC-MS between July 2008 and June 2010. After 3.2 years, 1623 of the 1996 participants were measured for fat mass (FM and %FM) over the total body (TB), trunk, limbs, android (A) and gynoid (G) regions. The %FM ratios of the A/G and the trunk and limbs were determined by dual-energy X-ray absorptiometry (DXA).
Results: Univariate analyses showed that higher serum betaine levels were significantly associated with lower values of adiposity indices, except in the case of the %FM at the gynoid area. After adjusting for potential covariates, similar associations were observed. The mean percentage differences between quartiles 4 and 1 of the serum betaine levels were -4.9% (weight), -4.7% (BMI), -2.5% (WC), -7.9% (TB FM) and -3.4% (TB %FM). The mean differences in the FM and %FM were much more pronounced at the trunk (-10.0% and -4.5%) or android areas (-10.7% and -4.7%) than those at the limbs (-0.8% and -2.3%) or gynoid areas (-0.6% and -1.4%). Such favorable associations were stronger in men than in women. No significant associations between serum choline and the adiposity indices were observed, except in the cases of body weight and BMI.
Conclusions: Greater circulating betaine, but not choline, was dose-dependently associated with better body composition and fat distribution due to a lower fat mass in the trunk regions in this population.

Chen, Y.-m., et al., Higher serum concentrations of betaine rather than choline is associated with better profiles of DXA-derived body fat and fat distribution in Chinese adults. Int J Obes, 2014.

Carnitine, erythritol and betaine may have efficacy in reducing innate inflammation in dry eye disease.

Purpose: To explore the effects of osmoprotectants on pro-inflammatory mediator production in primary human corneal epithelial cells (HCECs) exposed to hyperosmotic stress.
Methods: HCECs cultured in iso-osmolar medium (312 mOsM) were switched to hyperosmotic media with or without prior incubation with 2-20 mM of l-carnitine, erythritol or betaine for different time periods. The mRNA expression and protein production of pro-inflammatory markers in HCECs were evaluated by RT-qPCR and ELISA.
Results: Hyperosmolar media significantly stimulated the mRNA and protein expression of pro-inflammatory cytokines, TNF-alpha, IL-1beta and IL-6, and chemokines, IL-8, CCL2 and CCL20 in HCECs in an osmolarity dependent manner. The stimulated expression of these pro-inflammatory mediators was significantly but differentially suppressed by l-carnitine, erythritol or betaine. l-Carnitine displayed the greatest inhibitory effects and down-regulated 54-77% of the stimulated mRNA levels of TNF-alpha (down from 12.3-5.7 fold), IL-1beta (2.2-0.9 fold), IL-6 (7.3-2.9 fold), IL-8 (4.6-2.0 fold), CCL2 (15.3-3.5 fold) and CCL20 (4.1-1.5 fold) in HCECs exposed to 450 mOsM. The stimulated protein production of TNF-alpha, IL-1beta, IL-6 and IL-8 was also significantly suppressed by l-carnitine, erythritol and betaine. l-carnitine suppressed 49-79% of the stimulated protein levels of TNF-alpha (down from 81.3 to 17.4 pg/ml), IL-1beta (56.9-29.2 pg/ml), IL-6 (12.8-4.6 ng/ml) and IL-8 (21.2-10.9 ng/ml) by HCECs exposed to 450 mOsM. Interestingly, hyperosmolarity stimulated increase in mRNA and protein levels of TNF-alpha, IL-1beta and IL-6 were significantly suppressed by a transient receptor potential vanilloid channel type 1 (TRPV1) activation inhibitor capsazepine.
Conclusions: l-carnitine, erythritol and betaine function as osmoprotectants to suppress inflammatory responses via TRPV1 pathway in HCECs exposed to hyperosmotic stress. Osmoprotectants may have efficacy in reducing innate inflammation in dry eye disease.

Hua, X., et al., Effects of l-Carnitine, Erythritol and Betaine on Pro-inflammatory Markers in Primary Human Corneal Epithelial Cells Exposed to Hyperosmotic Stress. Curr Eye Res, 2014: p. 1-11.

Betaine or spinach completely suppress hyperhomocysteinemia induced by GAA supplementation or choline deficiency in rats

Betaine is an important natural component of rich food sources, especially spinach. Rats were fed diets with betaine or spinach powder at the same level of betaine for 10 days to investigate the dose-dependent effects of spinach powder supplementation on hyperhomocysteinemia induced by guanidinoacetic acid (GAA) addition and choline deprivation. The GAA-induced hyperhomocysteinemia in rats fed 25% casein diet (25C) was significantly suppressed by supplementation with betaine or spinach, and it was completely suppressed by taking 11.0% spinach supplementation. The choline deprivation-induced enhancement of plasma homocysteine concentration in rats fed 25% soybean protein diet (25S) was markedly suppressed by 3.82% spinach. Supplementation with betaine or spinach partially prevented the effects of GAA on hepatic concentrations of methionine metabolites. The decrease in activity of betaine-homocysteine S-methyltransferase (BHMT) and cystathionine beta-synthase (CBS) in GAA-induced hyperhomocysteinemia was recovered by supplementation with betaine or spinach. Supplementation with betaine or spinach did not affect BHMT activity, whereas it partially restored CBS activity in choline-deprived 25S. The results indicated that betaine or spinach could completely suppress the hyperhomocysteinemia induced by choline deficiency resulting from stimulating the homocysteine removal by both remethylation and cystathionine formation.

Liu, Y.Q., et al., Suppression effects of betaine-enriched spinach on hyperhomocysteinemia induced by guanidinoacetic Acid and choline deficiency in rats. ScientificWorldJournal, 2014. 2014: p. 904501

Maternal choline concentrations during pregnancy and choline-related genetic variants as risk factors for neural tube defects

BACKGROUND: Low maternal choline intake and blood concentration may be risk factors for having a child with a neural tube defect (NTD); however, the data are inconsistent. This is an important question to resolve because choline, if taken periconceptionally, might add to the protective effect currently being achieved by folic acid.
OBJECTIVE: We examined the relation between NTDs, choline status, and genetic polymorphisms reported to influence de novo choline synthesis to investigate claims that taking choline periconceptionally could reduce NTD rates.
DESIGN: Two study groups of pregnant women were investigated: women who had a current NTD-affected pregnancy (AP; n = 71) and unaffected controls (n = 214) and women who had an NTD in another pregnancy but not in the current pregnancy [nonaffected pregnancy (NAP); n = 98] and unaffected controls (n = 386). Blood samples to measure betaine and total choline concentrations and single nucleotide polymorphisms related to choline metabolism were collected at their first prenatal visit.
RESULTS: Mean (+/-SD) plasma total choline concentrations in the AP (2.8 +/- 1.0 mmol/L) and control (2.9 +/- 0.9 mmol/L) groups did not differ significantly. Betaine concentrations were not significantly different between the 2 groups. Total choline and betaine in the NAP group did not differ from controls. Cases were significantly more likely to have the G allele of phosphatidylethanolamine-N-methyltransferase (PEMT; V175M, +5465 G>A) rs7946 (P = 0.02).
CONCLUSIONS: Our results indicate that maternal betaine and choline concentrations are not strongly associated with NTD risk. The association between PEMT rs7946 and NTDs requires confirmation. The addition of choline to folic acid supplements may not further reduce NTD risk.

Mills, J.L., et al., Maternal choline concentrations during pregnancy and choline-related genetic variants as risk factors for neural tube defects. Am J Clin Nutr, 2014. 100(4): p. 1069-74

Maternal dietary betaine supplementation modifies hepatic expression of cholesterol metabolic genes via epigenetic mechanisms in newborn piglets

To elucidate the effects of maternal dietary betaine supplementation on hepatic expression of cholesterol metabolic genes in newborn piglets and the involved epigenetic mechanisms, we fed gestational sows with control or betaine-supplemented diets (3 g/kg) throughout pregnancy. Neonatal piglets born to betaine-supplemented sows had higher serum methionine concentration and hepatic content of betaine, which was associated with significantly up-regulated hepatic expression of glycine N-methyltransferase. Prenatal betaine exposure increased hepatic cholesterol content and modified the hepatic expression of cholesterol metabolic genes in neonatal piglets. Sterol regulatory element-binding protein 2 was down-regulated at both mRNA and protein levels, while 3-hydroxy-3-methylglutaryl CoA reductase (HMGCR) was down-regulated at the mRNA level, but up-regulated at the protein level, in betaine-exposed piglets. The transcriptional repression of HMGCR was associated with CpG island hypermethylation and higher repressive histone mark H3K27me3 (histone H3 lysine 27 trimethylation) on the promoter, whereas increased HMGCR protein content was associated with significantly decreased expression of miR-497. Furthermore, LDL receptor was significantly down-regulated at both mRNA and protein levels in the liver of betaine-exposed piglets, which was associated with promoter CpG hypermethylation. In addition, the expression of cholesterol-27alpha-hydroxylase (CYP27alpha1) was up-regulated at both mRNA and protein levels, while the expression of cholesterol-7alpha-hydroxylase (CYP7alpha1) was increased at the mRNA level, but unchanged at the protein level associated with increased expression of miR-181. These results indicate that maternal betaine supplementation increases hepatic cholesterol content in neonatal piglets through epigenetic regulations of cholesterol metabolic genes, which involve alterations in DNA and histone methylation and in the expression of microRNA targeting these genes.

Cai, D., et al., Maternal dietary betaine supplementation modifies hepatic expression of cholesterol metabolic genes via epigenetic mechanisms in newborn piglets. Br J Nutr, 2014: p. 1-10

Betaine supplementation in maternal diet modulates the epigenetic regulation of hepatic gluconeogenic genes in neonatal piglets.

In this study, gestational sows were fed control or betaine-supplemented diets (3 g/kg) throughout the pregnancy, and the newborn piglets were used to elucidate whether maternal dietary betaine affected offspring hepatic gluconeogenic genes through epigenetic mechanisms. Neonatal piglets born to betaine-supplemented sows had significantly higher serum and hepatic betaine contents, together with significantly greater expression of methionine metabolic enzymes in the liver. Interestingly, significantly higher serum concentrations of lactic acid and glucogenic amino acids, including serine, glutamate, methionine and histidine, were detected in the piglets born to betaine-supplemented sows, which were coincident with higher hepatic glycogen content and PEPCK1 enzyme activity, as well as greater protein expression of gluconeogenic enzymes, pyruvate carboxylase (PC), cytoplasmic phosphoenolpyruvate carboxykinase (PEPCK1), mitochondrional phosphoenolpyruvate carboxykinase (PEPCK2) and fructose-1, 6-bisphosphatase (FBP1). Moreover, maternal betaine significantly changed the methylation status of both CpGs and histones on the promoter of gluconeogenic genes. The lower PEPCK1 mRNA was associated with DNA hypermethylation and more enriched repression histone mark H3K27me3, while the up-regulated PEPCK2 and FBP1 mRNA was associated with DNA hypomethylation and more enriched activation histone mark H3K4me3. Furthermore, the expression of two miRNAs predicted to target PC and 6 miRNAs predicted to target PEPCK1 was dramatically suppressed in the liver of piglets born to betaine-supplemented sows. Our results provide the first evidence that maternal betaine supplementation affects hepatic gluconeogenic genes expression in newborn piglets through enhanced hepatic methionine metabolism and epigenetic regulations, which involve DNA and histone methylations, and possibly miRNAs-mediated post-transcriptional mechanism.

Cai, D., et al., Betaine supplementation in maternal diet modulates the epigenetic regulation of hepatic gluconeogenic genes in neonatal piglets. PLoS One, 2014. 9(8): p. e105504