Homocysteine and lipids: S-adenosyl methionine as a key intermediate

The functional roles of S-adenosyl-methionine and S-adenosyl-homocysteine and their involvement in trisomy 21

The one-carbon metabolism pathway is involved in critical human cellular functions such as cell proliferation, mitochondrial respiration, and epigenetic regulation. In the homocysteine-methionine cycle S-adenosyl-methionine (SAM) and S-adenosyl-homocysteine (SAH) are synthetized, and their levels are finely regulated to ensure proper functioning of key enzymes which control cellular growth and differentiation. Here we review the main biological mechanisms involving SAM and SAH and the known related human diseases. It was recently demonstrated that SAM and SAH levels are altered in plasma of subjects with trisomy 21 (T21) but how this metabolic dysregulation influences the clinical manifestation of T21 phenotype has not been previously described. This review aims at providing an overview of the biological mechanisms which are altered in response to changes in the levels of SAM and SAH observed in DS.

Nicotinamide N-methyltransferase (NNMT): a novel therapeutic target for metabolic syndrome

Metabolic syndrome (MetS) represents a constellation of metabolic abnormalities, typified by obesity, hypertension, hyperglycemia, and hyperlipidemia. It stems from intricate dysregulations in metabolic pathways governing energy and substrate metabolism. While comprehending the precise etiological mechanisms of MetS remains challenging, evidence underscores the pivotal roles of aberrations in lipid metabolism and insulin resistance (IR) in its pathogenesis. Notably, nicotinamide N-methyltransferase (NNMT) has recently surfaced as a promising therapeutic target for addressing MetS. Single nucleotide variants in the NNMT gene are significantly correlated with disturbances in energy metabolism, obesity, type 2 diabetes (T2D), hyperlipidemia, and hypertension. Elevated NNMT gene expression is notably observed in the liver and white adipose tissue (WAT) of individuals with diabetic mice, obesity, and rats afflicted with MetS. Knockdown of NNMT elicits heightened energy expenditure in adipose and hepatic tissues, mitigates lipid accumulation, and enhances insulin sensitivity. NNMT catalyzes the methylation of nicotinamide (NAM) using S-adenosyl-methionine (SAM) as the donor methyl group, resulting in the formation of S-adenosyl-l-homocysteine (SAH) and methylnicotinamide (MNAM). This enzymatic process results in the depletion of NAM, a precursor of nicotinamide adenine dinucleotide (NAD+), and the generation of SAH, a precursor of homocysteine (Hcy). Consequently, this cascade leads to reduced NAD+ levels and elevated Hcy levels, implicating NNMT in the pathogenesis of MetS. Moreover, experimental studies employing RNA interference (RNAi) strategies and small molecule inhibitors targeting NNMT have underscored its potential as a therapeutic target for preventing or treating MetS-related diseases. Nonetheless, the precise mechanistic underpinnings remain elusive, and as of yet, clinical trials focusing on NNMT have not been documented. Therefore, further investigations are warranted to elucidate the intricate roles of NNMT in MetS and to develop targeted therapeutic interventions.

Dietary choline intake and colorectal cancer: a cross-sectional study of 2005-2018 NHANES cycles

Background

It remains unclear if choline intake is associated with colorectal cancer. Therefore, we examined data from the National Health and Nutrition Examination Survey (NHANES).

Methods

This cross-sectional study included 32,222 U.S. adults in the 2005-2018 NHANE cycles, among whom 227 reported colorectal cancer. Dietary choline was derived from 24-h recalls. Logistic regression estimated odds of colorectal cancer across increasing intake levels, adjusting for potential confounders.

Results

After adjusting for sociodemographic variables, BMI, alcohol use, smoking status, comorbidities, and dietary factors (energy, fat, fiber, and cholesterol), the odds ratio (OR) for colorectal cancer was 0.86 (95% CI: 0.69-1.06, p = 0.162) per 100 mg higher choline intake. Across increasing quartiles of choline intake, a non-significant inverse trend was observed (Q4 vs. Q1 OR: 0.76, 95%CI: 0.37 ~ 1.55, P-trend = 0.23). Subgroup analyses revealed largely consistent associations, with a significant interaction by hypertension status (P-interaction =0.022).

Conclusion

In this large, nationally representative sample of U.S. adults, higher dietary choline intake was not significantly associated with colorectal cancer odds after adjusting for potential confounders. However, a non-significant inverse trend was observed. Further prospective studies are needed to confirm these findings and elucidate the underlying mechanisms.

A Case Report and Literature Review on Dietary Practices and Megaloblastic Anemia in a Young Female: Unraveling the Impact of Nutrition on Hematological Health

Megaloblastic anemia, stemming from vitamin B12 or folate deficiencies, poses diagnostic challenges due to its diverse clinical presentation. We report a case of a 25-year-old female college student presenting with symptoms indicative of megaloblastic anemia, attributed to her recent adoption of a strict vegetarian and vegan diet. Clinical manifestations included dizziness, palpitations, blurred vision, vertigo, headaches, burning sensations, excessive sweating, mouth ulcers, and unintentional weight loss. Physical examination revealed pale palpebral conjunctiva and sweating on the palms and soles. Laboratory findings confirmed megaloblastic anemia secondary to vitamin B12 deficiency, with elevated mean corpuscular volume (MCV), reticulocyte count, serum methylmalonic acid (MMA), and homocysteine levels. Treatment with intramuscular cyanocobalamin injections and oral vitamin B12 supplementation led to symptomatic improvement and normalization of hematological parameters. This case underscores the crucial role of dietary habits in hematological health. Vegetarian and vegan diets, devoid of animal products rich in vitamin B12, increase the risk of deficiency. Early recognition and management of such deficiencies are imperative to prevent long-term complications. A literature review corroborates the association between vegetarianism/veganism and megaloblastic anemia risk. Healthcare providers should vigilantly assess dietary histories, particularly in patients with hematological abnormalities. Further research is warranted to explore strategies for optimizing nutrient intake in individuals adhering to vegetarian or vegan diets, aiming to mitigate the risk of nutritional deficiencies and associated complications.

Association of serum folic acid levels in response to fasting blood glucose in early pregnancy with the risk of gestational diabetes mellitus: A retrospective cohort study

OBJECTIVE

With increasingly prevalent folic acid consumption in early pregnancy, concerns about its potentially negative effect on maternal metabolism have been raised. Recent findings regarding folic acid levels in the first trimester and the risk of gestational diabetes mellitus have been inconclusive. The aim of this study was to investigate the association of folic acid status in early pregnancy with gestational diabetes mellitus as well as examine whether glucose levels can be modulated by folic acid status during the same first trimester.

METHODS

This was a retrospective cohort study based on 27 128 Chinese pregnant women who registered during their first prenatal visit from January 2015 to December 2019. Serum folic acid and fasting blood glucose concentrations were measured during the 9th to 13th gestational weeks. Binary logistic regression was applied to estimate the odds ratios of gestational diabetes mellitus by using the serum folic acid levels quartiles with adjustment for major confounders. To investigate the potential effect of modifying key risk factors for gestational diabetes mellitus, we established subgroups, in which analyses were stratified by age (<25, 25-29, 30-34, and ≥35 y), parity (nulliparous and parous), prepregnancy body mass index (< 18.5, 18.5-23.9, and ≥ 24 kg/m2), and family history of diabetes (yes and no).

RESULTS

The positive association between maternal folate concentrations and fasting blood glucose was observed: the risk for hyperglycemia was higher in those in the middle (Q3) and higher (Q4) quartiles compared with those in Q1 and Q2. A higher risk for gestational diabetes mellitus was found in hyperglycemia of early pregnant women with high folate concentrations (Q3: odds ratio = 5.63; 95% CI, 4.56-6.95, and Q4: odds ratio = 5.57; 95% CI, 4.68-6.64) compared with normal fasting glucose mothers with folate concentrations in Q1 and Q2 after accounting for multiple covariables. Similar patterns were observed for different subgroups. Restricted cubic spline plots had a positive correlation of serum folic acid level with fasting blood glucose concentration as well as risk of gestational diabetes mellitus in a nonlinear pattern, with 32.5 nmol/L as the cutoff point for folic acid level.

CONCLUSIONS

Our findings underscore the importance of maintaining an appropriate folic acid concentration for preserving a lower risk of gestational diabetes mellitus, especially in women with relatively higher blood glucose in early pregnancy. Additionally, folic acid concentration > 32.5 nmol/L may be considered a risk factor for gestational diabetes mellitus. This research suggested that folic acid levels should be monitored during the first trimester from the first prenatal checkup to prevent adverse effects of excessive folic acid intake.

Folic acid and plasma lipids: Interactions and effect of folate supplementation

Dyslipidaemia and hyperhomocysteinemia are known risk factors for cardiovascular disease. While it is evident that optimization of plasma lipid is associated with low risk of cardiovascular disease in the general population, it is not yet fully clear whether reduction of homocysteinemia is associated with an improvement in risk in all subjects. The aim of our narrative review is to highlight eventual effects of folate supplementation on LDL-C levels, LDL-C oxidation and atherosclerosis-related complications. A comprehensive literature search was done in electronic database, including PubMed, Web of Science, Cochrane, and Scopus from inception up to January 2024. Based on the available evidence, epidemiological data, pathophysiological observations and meta-analyses of randomized clinical trials suggest that folic acid supplementation may modestly but significantly improve plasma lipid levels, lipid atherogenicity, and atherosclerosis-related early vascular damage, and that folic acid supplementation may significantly reduce the risk of cerebrovascular disease. Considering the low-cost and high safety profile of folic acid, its long-term supplementation could be considered for dyslypidaemic patients in secondary prevention for cardiovascular disease.

Dietary amino acid patterns and cardiometabolic risk factors among subjects with obesity; a cross-sectional study

BACKGROUND

The prevalence of obesity is a growing global public health concern. Certain dietary amino acids have been shown to have a potential therapeutic role in improving metabolic syndrome parameters and body composition in individuals with obesity. However, some amino acids have been linked to an increased risk of cardiometabolic disorders. This cross-sectional study aims to investigate the association between dietary amino acid patterns and cardiometabolic risk factors in individuals with obesity.

METHODS

This cross-sectional study included 335 participants with obesity (57.9% males and 41.5% females) from Tabriz and Tehran, Iran. The participants were between the ages of 20-50, with a body mass index (BMI) of 30 kg/m2 or higher, and free from certain medical conditions. The study examined participants' general characteristics, conducted anthropometric assessments, dietary assessments, and biochemical assessments. The study also used principal component analysis to identify amino acid intake patterns and determined the association between these patterns and cardiometabolic risk factors in individuals with obesity.

RESULTS

Upon adjusting for potential confounders, the study found that individuals in the third tertiles of pattern 1 and 2 were more likely to have lower LDL levels (OR = 0.99 and 95% CI (0.98-0.99)) for both. Additionally, a significant decrease in total cholesterol was observed in the third tertiles of pattern 2 in model II (OR = 0.99, 95% CI (0.98-0.99)). These findings suggest a potential cardioprotective effect of these amino acid patterns in managing cardiometabolic risk factors in individuals with obesity.

CONCLUSIONS

This study found that two identified amino acid patterns were associated with lower serum LDL and total cholesterol levels, while a third pattern was associated with higher serum triglycerides. The specific amino acids contributing to these patterns highlight the importance of targeted dietary interventions in managing cardiometabolic risk factors in individuals with obesity.

Enhancing Metabolism and Milk Production Performance in Periparturient Dairy Cattle through Rumen-Protected Methionine and Choline Supplementation

For dairy cattle to perform well throughout and following lactations, precise dietary control during the periparturient phase is crucial. The primary issues experienced by periparturient dairy cows include issues like decreased dry matter intake (DMI), a negative energy balance, higher levels of non-esterified fatty acids (NEFA), and the ensuing inferior milk output. Dairy cattle have always been fed a diet high in crude protein (CP) to produce the most milk possible. Despite the vital function that dairy cows play in the conversion of dietary CP into milk, a sizeable percentage of nitrogen is inevitably expelled, which raises serious environmental concerns. To reduce nitrogen emissions and their production, lactating dairy cows must receive less CP supplementation. Supplementing dairy cattle with rumen-protected methionine (RPM) and choline (RPC) has proven to be a successful method for improving their ability to use nitrogen, regulate their metabolism, and produce milk. The detrimental effects of low dietary protein consumption on the milk yield, protein yield, and dry matter intake may be mitigated by these nutritional treatments. In metabolic activities like the synthesis of sulfur-containing amino acids and methylation reactions, RPM and RPC are crucial players. Methionine, a limiting amino acid, affects the production of milk protein and the success of lactation in general. According to the existing data in the literature, methionine supplementation has a favorable impact on the pathways that produce milk. Similarly, choline is essential for DNA methylation, cell membrane stability, and lipid metabolism. Furthermore, RPC supplementation during the transition phase improves dry matter intake, postpartum milk yield, and fat-corrected milk (FCM) production. This review provides comprehensive insights into the roles of RPM and RPC in optimizing nitrogen utilization, metabolism, and enhancing milk production performance in periparturient dairy cattle, offering valuable strategies for sustainable dairy farming practices.

Additive effect between homocysteine and low-density-lipoprotein cholesterol upon incidence of novel carotid plaque formation: data from a Chinese community-based cohort

OBJECTIVE

Homocysteine (HCY) has been associated with carotid plaque in cross-sectional studies, but the prospective relationship between HCY and incident carotid plaque has not been well established. The purpose of this study was to investigate the association between HCY and incidence of novel carotid plaque in a Chinese community-based population without pre-existing carotid atherosclerosis and to assess the additive effect of HCY and low-density lipoprotein cholesterol (LDL-C) on the incidence of novel plaque.

METHODS

At baseline, we measured HCY and other risk factors in subjects aged ≥ 40 years. All participants underwent carotid ultrasound examinations at baseline and after an average of 6.8 years of follow-up. Incidence of plaque was identified if plaque was absent at baseline, but plaque was detected at the end of follow-up. A total of 474 subjects were included in the analysis.

RESULTS

The incidence of novel carotid plaque was 24.47%. Multivariate regression analyses showed that HCY was independently associated with a 1.05-fold-higher likelihood for incident novel plaque (adjusted odds ratio [OR] = 1.05, 95% confidence interval [CI]: 1.01-1.09, P = 0.008). Using tertile 1 and tertile 2 for reference, the top HCY tertile (T3) showed a 2.28-fold-higher likelihood for incident plaque (adjusted OR = 2.28, 95%CI: 1.33-3.93, P = 0.002). The combination of HCY T3 and LDL-C ≥ 3.4 mmol/L had the highest risk for novel plaque formation (adjusted OR = 3.63, 95%CI: 1.67-7.85, P = 0.001) compared to those without either condition. In the LDL-C ≥ 3.4 mmol/L subgroup, HCY was significantly associated with incidence of plaque (adjusted OR = 1.16, 95%CI: 1.04-1.28, P = 0.005, P-interaction = 0.023).

CONCLUSION

In the Chinese community-based population, HCY was independently associated with the incidence of novel carotid plaque. There were additive effect between HCY and LDL-C on the incidence of plaque, the highest risk was observed in individuals with both high HCY levels and LDL-C ≥ 3.4 mmol/L. Our findings suggest that HCY may be a potential target for preventing the incidence of carotid plaque, particularly in individuals with elevated LDL-C levels.

Habitual Tea Consumption Increases the Incidence of Metabolic Syndrome in Middle-Aged and Older Individuals

In middle-aged and elderly individuals, the relationship between tea consumption and incident metabolic syndrome (MetS) is still unclear. Therefore, this study intends to figure out the relationship between tea-drinking frequency and MetS in rural middle-aged and older Chinese residents. In the Northeast China Rural Cardiovascular Health Study, 3632 middle-aged or older individuals (mean age 57 ± 8, 55.2% men) without MetS were included at baseline during 2012–2013 and were followed up on between 2015–2017. Participants showing differential tea consumption frequency were divided into the following classes: non-habitual tea drinkers, occasional tea drinkers, 1–2 times/day drinkers, and ≥3 times/day drinkers. Data showed that non-habitual tea drinking was more common among women. The frequency of tea consumption was higher in ethnic groups other than Han and among singles, as well as in concurrent smokers and drinkers and individuals with primary or lower educational status. The increasing tea consumption was in line with baseline elevations in body mass index, systolic and diastolic blood pressure, high-density lipoprotein cholesterol (HDL-C), and AST/ALT ratio. Multivariate logistic regression analysis confirmed that occasional tea drinking increased the incidence of low HDL-C [OR (95% CI): 1.268 (1.015, 1.584)], high waist circumference [OR (95% CI): 1.336 (1.102, 1.621)], and MetS [OR (95% CI): 1.284 (1.050, 1.570)]. In addition, 1–2 times/day tea drinking increased the cumulative incidence of high TG [OR (95% CI): 1.296 (1.040, 1.616)], high waist circumference [OR (95% CI): 1.296 (1.044, 1.609)] and MetS [OR (95% CI): 1.376 (1.030, 1.760)]. We demonstrated that regular tea consumption is correlated with a greater incidence of metabolic disorders and MetS. Our findings may help clarify the contradictory association reported between tea drinking and MetS development in middle-aged and older residents of rural China.

Association of Folic Acid Supplementation, Dietary Folate Intake and Serum Folate Levels with Risk of Gestational Diabetes Mellitus: A Matched Case-Control Study

Periconceptional folate supplementation is prevalent, raising concerns about possible side effects. The aim of this study was to investigate the associations of folic acid supplementation, dietary folate, serum folate with gestational diabetes mellitus (GDM) risk. In this matched case-control study, 81 pregnant women with GDM (cases) and 81 pregnant women with non-GDM (controls) were identified through age difference (≤3 y) and parity (Both primipara or multipara women) matching, and serum folate levels were measured during the GDM screening (24-28 gestational wk). Folic acid supplementation and dietary folate intake from three months prepregnancy through midpregnancy were assessed using a self-reported questionnaire and food frequency questionnaire. Multivariate binary logistic regression models were used to evaluate the association between folate and GDM. After adjusting for confounding factors, we observed that compared with folic acid supplementation dose ≤400 μg/d, pregnancies without folic acid supplementation and supplemental dose >800 μg/d were associated with GDM risk (adjusted odds ratio=7.25, 95% confidence interval: 1.34-39.36; adjusted odds ratio=4.20, 95% confidence interval: 1.03-17.22), while no significant association with a 400-800 μg/d dose of folic acid supplementation and GDM. Compared with folic acid supplementation dose ≤24 wk, pregnancies without folic acid supplementation were associated with GDM risk (adjusted odds ratio=6.70, 95% confidence interval: 1.22-36.77), while no significant association with folic acid supplementation dose >24 wk and GDM. No significant association of dietary folate and serum folate with GDM was found. No or a higher dose of folic acid supplementation would increase GDM risk and a dose of <800 μg/d is the safe dose.

Offspring NAFLD liver phospholipid profiles are differentially programmed by maternal high-fat diet and maternal one carbon supplement

Little is known if and how maternal diet affects the liver phospholipid profiles that contribute to non-alcoholic fatty liver disease (NAFLD) development in offspring. We examined NAFLD phenotypes in male offspring mice of either maternal normal-fat diet (NF group), maternal high-fat diet (HF group), maternal methionine supplement (H1S group), or complete one-carbon supplement (H2S group) added to the maternal HF diet during gestation and lactation. HF offspring displayed worsened NAFLD phenotypes induced by post-weaning HF diet, however, maternal one-carbon supplement prevented such outcome. HF offspring also showed a distinct phospholipid profile from the offspring exposed to H1S or H2S diet. Whole genome bisulfite sequencing (WGBS) analysis further identified five pathways involved in phospholipid metabolism altered by different maternal diet interventions. Furthermore, differential methylated regions (DMRs) on Prkca, Dgkh, Plcb1 and Dgki were identified comparing between HF and NF offspring; most of these DMRs were recovered in H2S offspring. These methylation pattern changes were associated with gene expression changes: HF diet significantly reduced while H1S and H2S diet recovered their levels. Maternal HF diet disrupted offspring phospholipid profiles contributing to worsened hepatic steatosis. The maternal one-carbon supplement prevented such effects, probably through DNA methylation modification.

A diagnostic model for overweight and obesity from untargeted urine metabolomics of soldiers

Soldiers in active military service need optimal physical fitness for successfully carrying out their operations. Therefore, their health status is regularly checked by army doctors. These inspections include physical parameters such as the body-mass index (BMI), functional tests, and biochemical studies. If a medical exam reveals an individual's excess weight, further examinations are made, and corrective actions for weight lowering are initiated. The collection of urine is non-invasive and therefore attractive for frequent metabolic screening. We compared the chemical profiles of urinary samples of 146 normal weight, excess weight, and obese soldiers of the Mexican Army, using untargeted metabolomics with liquid chromatography coupled to high-resolution mass spectrometry (LC-MS). In combination with data mining, statistical and metabolic pathway analyses suggest increased S-adenosyl-L-methionine (SAM) levels and changes of amino acid metabolites as important variables for overfeeding. We will use these potential biomarkers for the ongoing metabolic monitoring of soldiers in active service. In addition, after validation of our results, we will develop biochemical screening tests that are also suitable for civil applications.

The Efficacy of S-Adenosyl Methionine and Probiotic Supplementation on Depression: A Synergistic Approach

Depression is a common and serious health issue affecting around 280 million people around the world. Suicidal ideation more frequently occurs in people with moderate to severe depression. Psychotherapy and pharmacological drugs are the mainstay of available treatment options for depressive disorders. However, pharmacological options do not offer complete cure, especially in moderate to severe depression, and are often seen with a range of adverse events. S-adenosyl methionine (SAMe) supplementation has been widely studied, and an impressive collection of literature published over the last few decades suggests its antidepressant efficacy. Probiotics have gained significant attention due to their wide array of clinical uses, and multiple studies have explored the link between probiotic species and mood disorders. Gut dysbiosis is one of the risk factors in depression by inducing systemic inflammation accompanied by an imbalance in neurotransmitter production. Thus, concomitant administration of probiotics may be an effective treatment strategy in patients with depressed mood, particularly in resistant cases, as these can aid in dysbiosis, possibly resulting in the attenuation of systemic inflammatory processes and the improvement of the therapeutic efficacy of SAMe. The current review highlights the therapeutic roles of SAMe and probiotics in depression, their mechanistic targets, and their possible synergistic effects and may help in the development of food supplements consisting of a combination of SAMe and probiotics with new dosage forms that may improve their bioavailability.

Reversal of Lipid Metabolism Dysregulation by Selenium and Folic Acid Co-Supplementation to Mitigate Pathology in Alzheimer’s Disease

Aberrant lipid metabolism is reported to be closely related to the pathogenesis of neurodegenerative diseases, such as Alzheimer’s disease (AD). Selenium (Se) and folate are two ideal and safe nutritional supplements, whose biological effects include regulating redox and homocysteine (Hcy) homeostasis in vivo. Here, to achieve effective multitarget therapy for AD, we combined Se and folic acid in a co-supplementation regimen (Se-FA) to study the therapeutic potential and exact mechanism in two transgenic mouse models of AD (APP/Tau/PSEN and APP/PS1). In addition to a reduction in Aβ generation and tau hyperphosphorylation, a restoration of synaptic plasticity and cognitive ability was observed in AD mice upon Se-FA administration. Importantly, by using untargeted metabolomics, we found that these improvements were dependent on the modulation of brain lipid metabolism, which may be associated with an antioxidant effect and the promotion of Hcy metabolism. Thus, from mechanism to effects, this study systematically investigated Se-FA as an intervention for AD, providing important mechanistic insights to inform its potential use in clinical trials.

Effects of a 12-week whole-grain or refined wheat intervention on plasma acylcarnitines, bile acids and signaling lipids, and association with liver fat: A post-hoc metabolomics study of a randomized controlled trial

BACKGROUND

We previously showed that whole-grain wheat (WGW) consumption had beneficial effects on liver fat accumulation, as compared to refined wheat (RW). The mechanisms underlying these effects remain unclear.

OBJECTIVE

In this study, we investigated the effects of WGW vs. RW consumption on plasma metabolite levels to explore potential underlying mechanisms of the preventive effect of WGW consumption on liver fat accumulation.

METHODS

Targeted metabolomics of plasma obtained from a concluded 12-week double-blind, randomized controlled trial was performed. Fifty overweight or obese men and women aged 45-70 years with mildly elevated levels of plasma cholesterol were randomized to either 98 g/d of WGW or RW products. Before and after the intervention, a total of 89 fasting plasma metabolite concentrations including acylcarnitines, trimethylamine-N-oxide (TMAO), choline, betaine, bile acids, and signaling lipids were quantified by UPLC-MS/MS. Intrahepatic triglycerides (IHTG) were quantified by ¹H-MRS, and multiple liver markers, including circulating levels of β-hydroxybutyrate, alanine transaminase (ALT), aspartate transaminase (AST), γ-glutamyltransferase (γ-GT), serum amyloid A (SAA), and C-reactive protein, were assessed.

RESULTS

The WGW intervention increased plasma concentrations of four out of 52 signaling lipids-lysophosphatidic acid C18:2, lysophosphatidylethanolamine C18:1 and C18:2, and platelet-activating factor C18:2-and decreased concentrations of the signaling lipid lysophosphatidylglycerol C20:3 as compared to RW intervention, although these results were no longer statistically significant after false discovery rate (FDR) correction. Plasma concentrations of the other metabolites that we quantified were not affected by WGW or RW intervention. Changes in the above-mentioned metabolites were not correlated to change in IHTG upon the intervention.

CONCLUSION

Plasma acylcarnitines, bile acids, and signaling lipids were not robustly affected by the WGW or RW interventions, which makes them less likely candidates to be directly involved in the mechanisms that underlie the protective effect of WGW consumption or detrimental effect of RW consumption on liver fat accumulation.

CLINICAL TRIAL REGISTRATION

[www.ClinicalTrials.gov], identifier [NCT02385149].

Metabolomics and lipidomics in NAFLD: biomarkers and non-invasive diagnostic tests

Nonalcoholic fatty liver disease (NAFLD) is one of the most common liver diseases worldwide and is often associated with aspects of metabolic syndrome. Despite its prevalence and the importance of early diagnosis, there is a lack of robustly validated biomarkers for diagnosis, prognosis and monitoring of disease progression in response to a given treatment. In this Review, we provide an overview of the contribution of metabolomics and lipidomics in clinical studies to identify biomarkers associated with NAFLD and nonalcoholic steatohepatitis (NASH). In addition, we highlight the key metabolic pathways in NAFLD and NASH that have been identified by metabolomics and lipidomics approaches and could potentially be used as biomarkers for non-invasive diagnostic tests. Overall, the studies demonstrated alterations in amino acid metabolism and several aspects of lipid metabolism including circulating fatty acids, triglycerides, phospholipids and bile acids. Although we report several studies that identified potential biomarkers, few have been validated.

Improvement of cognitive performance by a nutraceutical formulation: Underlying mechanisms revealed by laboratory studies

Cognitive decline, decrease in neuronal function and neuronal loss that accompany normal aging and dementia are the result of multiple mechanisms, many of which involve oxidative stress. Herein, we review these various mechanisms and identify pharmacological and non-pharmacological approaches, including modification of diet, that may reduce the risk and progression of cognitive decline. The optimal degree of neuronal protection is derived by combinations of, rather than individual, compounds. Compounds that provide antioxidant protection are particularly effective at delaying or improving cognitive performance in the early stages of Mild Cognitive Impairment and Alzheimer's disease. Laboratory studies confirm alleviation of oxidative damage in brain tissue. Lifestyle modifications show a degree of efficacy and may augment pharmacological approaches. Unfortunately, oxidative damage and resultant accumulation of biomarkers of neuronal damage can precede cognitive decline by years to decades. This underscores the importance of optimization of dietary enrichment, antioxidant supplementation and other lifestyle modifications during aging even for individuals who are cognitively intact.

Association between homocysteine and obesity: A meta-analysis

According to previous studies of obesity, we found that the association between homocysteine concentrations and obesity was reported controversially. Thus, we carried out this meta-analysis to investigate this association. We searched PubMed, The Cochrane library, and EMBASE database for studies that evaluate the relationship between homocysteine concentrations and obesity from inception to March, 2019. The quality of all included studies was assessed by the Newcastle Ottawa Scale (NOS) and the Agency for Healthcare Research Quality (AHRQ). The RevMan5.3 software and Stata12.0 software were used for conducting all data analyses. Standardized mean differences (SMD) with the corresponding 95% confidence intervals (95% CIs) were used as a measure of effect size to assess the relationship between homocysteine concentrations and obesity through a meta-analysis. The level of significance was set at P < .05. A total of 14 studies were ultimately included in our meta-analysis. Meta-analysis of the 14 studies found remarkable lower homocysteine concentrations in controls than in obese patients (SMD = 0.76, 95% CI = 0.25-1.27, P < .01; I²  = 94% and P < .01 for heterogeneity), regardless of nutritional status, dietary habit, insulin resistance (IR) status, special disease history, history of medicine taken, genetic background, and so on. Homocysteine concentrations in nonobese patients with polycystic ovarian syndrome (PCOS) were lower than obese patients with PCOS (SMD = 0.48, 95% CI = 0.20-0.77, P < .01; I²  = 39% and P = .18 for heterogeneity). The result of our meta-analysis showed that homocysteine concentrations were significantly elevated among obese patients.

Treatment with PCSK9 Inhibitors in Patients with Familial Hypercholesterolemia Lowers Plasma Levels of Platelet-Activating Factor and Its Precursors: A Combined Metabolomic and Lipidomic Approach

INTRODUCTION

Familial hypercholesterolemia (FH) is characterized by extremely high levels of circulating low-density lipoprotein cholesterol (LDL-C) and is caused by mutations of genes involved in LDL-C metabolism, including LDL receptor (LDLR), apolipoprotein B (APOB), or proprotein convertase subtilisin/Kexin type 9 (PCSK9). Accordingly, PCSK9 inhibitors (PCSK9i) are effective in LDL-C reduction. However, no data are available on the pleiotropic effect of PCSK9i. To this end, we performed an untargeted metabolomics approach to gather a global view on changes in metabolic pathways in patients receiving treatment with PCSK9i.

METHODS

Twenty-five FH patients starting treatment with PCSK-9i were evaluated by an untargeted metabolomics approach at baseline (before PCSK9i treatment) and after 12 weeks of treatment.

RESULTS

All the 25 FH subjects enrolled were on maximal tolerated lipid-lowering therapy prior to study entry. After a 12 week treatment with PCSK9i, we observed an expected significant reduction in LDL-cholesterol levels (from 201.0 ± 69.5 mg/dL to 103.0 ± 58.0 mg/dL, p < 0.001). The LDL-C target was achieved in 36% of patients. After peak validation and correction, after 12 weeks of PCSK9i treatment as compared to baseline, we observed increments in creatine (p-value = 0.041), indole (p-value = 0.045), and indoleacrylic acid (p-value= 0.045) concentrations. Conversely, significant decreases in choline (p-value = 0.045) and phosphatidylcholine (p-value < 0.01) together with a reduction in platelet activating factor (p-value = 0.041) were observed.

CONCLUSIONS

Taking advantage of untargeted metabolomics, we first provided evidence of concomitant reductions in inflammation and platelet activation metabolites in FH patients receiving a 12 week treatment with PCSK9i.

Dynamic recovery after acute single fine particulate matter exposure in male mice: Effect on lipid deregulation and cardiovascular alterations

Many studies have linked airborne fine particulate matter (PM2.5) exposure to cardiovascular diseases. We performed a time-series analysis to investigate whether the disruption of lipid metabolism recovered or lasted after acute PM2.5 exposure in mice. Targeted lipidomic analysis showed that four major plasma membrane phospholipids along with cholesterol esters (CE) were significantly altered on 7th post-exposure day (PED7), and the alteration reached a peak on PED14. On PED21, the phosphatidylcholine (PC) decrease was more marked than on PED14, and its resurgence was indirectly linked to triglyceride (TG) increase. Homocysteine (HCY), lactate dehydrogenase (LDH), and α-hydroxybutyrate dehydrogenase (α-HBDH) levels increased but glucose levels decreased markedly in a dose- and time-dependent manner throughout the experimental period. Network analysis showed that the lasting lipid deregulation on PED21 correlated to myocardial markers and glucose interruption, during which high-density lipoprotein cholesterol (HDL-C) decreased. The present data implied that the constructional membrane lipids were initially interrupted by PM2.5, and the subsequent rehabilitation resulted in the deregulation of storage lipids; the parallel myocardial and glucose effects may be enhanced by the lasting HDL-C lipid deregulation on PED21. These myocardial and lipidomic events were early indicators of cardiovascular risk, resulting from subsequent exposure to and accumulation of PM2.5.

Vitamins and non-alcoholic fatty liver disease: A Molecular Insight⋆

The incidence of non-alcoholic fatty liver disease (NAFLD) is rising rapidly across the globe. NAFLD pathogenesis is largely driven by an imbalance in hepatic energy metabolism and at present, there is no approved drug for its treatment. The liver plays a crucial role in micronutrient metabolism and deregulation of this micronutrient metabolism may contribute to the pathogenesis of NAFLD. Vitamins regulate several enzymatic processes in the liver, and derangement in vitamin metabolism is believed to play a critical role in NAFLD progression. The anti-oxidant activities of vitamin C and E have been attributed to mitigate hepatocyte injury, and alterations in the serum levels of vitamin D, vitamin B12 and folate have shown a strong correlation with NAFLD severity. This review aims to highlight the role of these vitamins, which represent promising therapeutic targets for the management of NAFLD.

Methylation as a key regulator of Tau aggregation and neuronal health in Alzheimer's disease

Neurodegenerative diseases like Alzheimer's, Parkinson's and Huntington's disease involves abnormal aggregation and accumulation of toxic proteins aggregates. Post-translational modifications (PTMs) of the causative proteins play an important role in the etiology of disease as they could either slow down or accelerate the disease progression. Alzheimer disease is associated with the aggregation and accumulation of two major protein aggregates-intracellular neurofibrillary tangles made up of microtubule-associated protein Tau and extracellular Amyloid-β plaques. Post-translational modifications are important for the regulation of Tau`s function but an imbalance in PTMs may lead to abnormal Tau function and aggregation. Tau methylation is one of the important PTM of Tau in its physiological state. However, the methylation signature on Tau lysine changes once it acquires pathological aggregated form. Tau methylation can compete with other PTMs such as acetylation and ubiquitination. The state of PTM at these sites determines the fate of Tau protein in terms of its function and stability. The global methylation in neurons, microglia and astrocytes are involved in multiple cellular functions involving their role in epigenetic regulation of gene expression via DNA methylation. Here, we have discussed the effect of methylation on Tau function in a site-specific manner and their cross-talk with other lysine modifications. We have also elaborated the role of methylation in epigenetic aspects and neurodegenerative conditions associated with the imbalance in methylation metabolism affecting global methylation state of cells. Video abstract.

A Novel Review of Homocysteine and Pregnancy Complications

Homocysteine (Hct) is a substance produced in the metabolism of methionine. It is an essential type of amino acid gained from the daily diet. Methylenetetrahydrofolate reductase (MTHFR) gene mutation is related to elevated total homocysteine (tHct) expressions, in particular, among women with low folate intake. Hyperhomocysteinemia (HHct) is caused by numerous factors, such as genetic defects, lack of folic acid, vitamin B₆ and B₁₂ deficiency, hypothyroidism, drugs, aging, and renal dysfunction. Increased Hct in peripheral blood may lead to vascular illnesses, coronary artery dysfunction, atherosclerotic changes, and embolic diseases. Compared to nonpregnant women, the Hct level is lower in normal pregnancies. Recent studies have reported that HHct was associated with numerous pregnancy complications, including recurrent pregnancy loss (RPL), preeclampsia (PE), preterm delivery, placental abruption, fetal growth restriction (FGR), and gestational diabetes mellitus (GDM). Besides, it was discovered that neonatal birth weight and maternal Hct levels were negatively correlated. However, a number of these findings lack consistency. In this review, we summarized the metabolic process of Hct in the human body, the levels of Hct in different stages of normal pregnancy reported in previous studies, and the relationship between Hct and pregnancy complications. The work done is helpful for obstetricians to improve the likelihood of a positive outcome during pregnancy complications. Reducing the Hct level with a high dosage of folic acid supplements during the next pregnancy could be helpful for females who have suffered pregnancy complications due to HHct.

Lipid remodeling in response to methionine stress in MDA-MBA-468 triple-negative breast cancer cells

Methionine (Met) is an essential amino acid and critical precursor to the cellular methyl donor S-adenosylmethionine. Unlike nontransformed cells, cancer cells have a unique metabolic requirement for Met and are unable to proliferate in growth media where Met is replaced with its metabolic precursor, homocysteine. This metabolic vulnerability is common among cancer cells regardless of tissue origin and is known as "methionine dependence", "methionine stress sensitivity", or the Hoffman effect. The response of lipids to Met stress, however, is not well-understood. Using mass spectroscopy, label-free vibrational microscopy, and next-generation sequencing, we characterize the response of lipids to Met stress in the triple-negative breast cancer cell line MDA-MB-468 and its Met stress insensitive derivative, MDA-MB-468res-R8. Lipidome analysis identified an immediate, global decrease in lipid abundances with the exception of triglycerides and an increase in lipid droplets in response to Met stress specifically in MDA-MB-468 cells. Furthermore, specific gene expression changes were observed as a secondary response to Met stress in MDA-MB-468, resulting in a downregulation of fatty acid metabolic genes and an upregulation of genes in the unfolded protein response pathway. We conclude that the extensive changes in lipid abundance during Met stress is a direct consequence of the modified metabolic profile previously described in Met stress-sensitive cells. The changes in lipid abundance likely results in changes in membrane composition inducing the unfolded protein response we observe.

Plasma phospholipid dysregulation in patients with cystathionine-β synthase deficiency

BACKGROUND & AIMS

Patients with cystathionine β-synthase deficiency (CBSD) exhibit high circulating levels of homocysteine and enhanced lipid peroxidation. We have characterized the plasma lipidome in CBSD patients and related lipid abnormalities with reactions underlying enhanced homocysteine levels.

METHODS AND RESULTS

Using an ultra-high-performance liquid chromatography-electrospray ionization-quadrupole-time of flight-mass spectrometry method, plasma lipids were determined with an untargeted lipidomics approach in 11 CBSD patients and 11 matched healthy subjects (CTRL). Compared to CTRL, CBSD patients had a higher medium and long-chain polyunsaturated fatty acids (PUFA) content in phosphatidylethanolamine (PE) and lysophosphatidylethanolamine (LPE) species (p < 0.02), and depletion of phosphatidylcholine (PC; p = 0.02) and of lysophosphatidylcholine (LPC; p = 0.003) species containing docosahexaenoic acid (DHA), suggesting impaired phosphatidylethanolamine-N-methyltransferase (PEMT) activity. PEMT converts PE into PC using methyl group by S-adenosylmethionine (SAM) thus converted in S-adenosylhomocysteine (SAH). Whole blood SAM and SAH concentrations by liquid chromatography tandem mass spectrometry were 1.4-fold (p = 0.015) and 5.3-fold (p = 0.003) higher in CBSD patients than in CTRL. A positive correlation between SAM/SAH and PC/PE ratios (r = 0.520; p = 0.019) was found.

CONCLUSIONS

A novel biochemical abnormality in CBSD patients consisting in depletion of PC and LPC species containing DHA and accumulation of PUFA in PE and LPE species is revealed by this lipidomic approach. Changes in plasma SAM and SAH concentrations are associated with such phospholipid dysregulation. Given the key role of DHA in thrombosis prevention, depletion of PC species containing DHA in CBSD patients provides a new direction to understand the poor cardiovascular outcome of patients with homocystinuria.

Epigenetic landscape of stress surfeit disorders: Key role for DNA methylation dynamics

Chronic exposure to stress throughout lifespan alters brain structure and function, inducing a maladaptive response to environmental stimuli, that can contribute to the development of a pathological phenotype. Studies have shown that hypothalamic-pituitary-adrenal (HPA) axis dysfunction is associated with various neuropsychiatric disorders, including major depressive, alcohol use and post-traumatic stress disorders. Downstream actors of the HPA axis, glucocorticoids are critical mediators of the stress response and exert their function through specific receptors, i.e., the glucocorticoid receptor (GR), highly expressed in stress/reward-integrative pathways. GRs are ligand-activated transcription factors that recruit epigenetic actors to regulate gene expression via DNA methylation, altering chromatin structure and thus shaping the response to stress. The dynamic interplay between stress response and epigenetic modifiers suggest DNA methylation plays a key role in the development of stress surfeit disorders.

Low Serum Vitamin B12 Levels Are Associated with Adverse Lipid Profiles in Apparently Healthy Young Saudi Women

An abnormal lipid profile is an independent risk factor for cardiovascular diseases. The relationship between vitamin B12 deficiency and lipid profile is inconclusive, with most studies conducted in unhealthy populations. In this study, we aimed to assess the relationship between serum vitamin B12 levels and lipid profiles in a cross-sectional study that included 341 apparently healthy Saudi women, aged 19-30 years, from different colleges at King Saud University, Saudi Arabia. Sociodemographic, anthropometric, biochemical, and lifestyle data were collected, including diet and physical activity. Serum vitamin B12 deficiency was defined as serum B12 level of <148 pmol/L. The prevalence of vitamin B12 deficiency was approximately 0.6%. Using multivariable linear regression models, serum vitamin B12 levels were found to be inversely associated with total cholesterol (B = -0.26; p < 0.001), low-density lipoprotein cholesterol levels (B = -0.30; p < 0.001), and triglyceride (B = -0.16; p < 0.01) after adjusting for potential confounders, while obesity indices of body mass index, central obesity, and fat percentage showed no association. Therefore, we conclude that low serum vitamin B12 levels are independently associated with abnormal lipid profiles in healthy young Saudi women. Further interventional studies are needed to determine whether improving serum vitamin B12 levels in a healthy population can improve lipid profiles.

Ocimum Sanctum Linn: A Potential Adjunct Therapy for Hyperhomocysteinemia-Induced Vascular Dementia

Vascular dementia (VaD) is well recognized as the second most familiar form of dementia in the aged population. The present study is aimed to investigate the neuroprotective effects of ethanolic extract of leaves of Ocimum sanctum (EEOS) against hyperhomocysteinemia (HHcy)-induced vascular dementia (VaD) in Wistar rats. HHcy was induced by administering L-methionine (1.7 g/kg, p.o) for 4 weeks. Donepezil (0.1 mg/kg, p.o.) and EEOS (100 mg/kg, 200 mg/kg, 400 mg/kg, p.o.) were administered from the 14^th day of L-methionine treatment. The behavioral impairment caused due to HHcy in rats was assessed by the Morris water maze (MWM) and Y-maze tests using a video tracking system. Biochemical estimations and aortic ring assay were also performed followed by a molecular docking analysis of active chemical constituents present in the leaves of Ocimum sanctum Linn. In this study, the EEOS treatment in hyperhomocysteinemic rats has showed significant improvement in spatial learning and working memory performance. The EEOS treatment further increased nitric oxide bioavailability and significantly altered all serum and brain biochemical parameters in a dose-dependent manner. The docking analysis revealed that among all the phytoconstituents of Ocimum sanctum compound (IX), molludistin has showed good inhibitory activity against S-adenosyl homocysteine, thus preventing homocysteine formation and may be responsible for potential effects of EEOS against HHcy-induced VaD. From our results, we conclude that EEOS can be used as a promising adjunct therapy for treatment of HHcy-induced VaD and oxidative stress.

The Multispecies Probiotic Effectively Reduces Homocysteine Concentration in Obese Women: A Randomized Double-Blind Placebo-Controlled Study

Dysregulated metabolism of homocysteine (Hcy) is associated with obesity. Supplementation with probiotics can potentially be a natural therapeutic method for metabolic disorders. The precise mechanism in which microbiota affect Hcy metabolism in obese individuals is still unknown. The aim of this study was to evaluate the effects of a 12-week supplementation with a multispecies probiotic on Hcy levels, oxidative stress, inflammation and lipid profile in obese patients. This randomized double-blind placebo-controlled trial was performed on 50 obese women (aged 45–70 years). Subjects were randomly assigned to take either a multispecies probiotic supplement (n = 25) or placebo (n = 25) for 12 weeks. The probiotic contained nine bacterial strains containing 2.5 × 10⁹ CFU/g. Biochemical and anthropometric measurements were carried out at baseline and after 12 weeks of intervention. At the end of the study, a significant decrease in Hcy, tumor necrosis factor α (TNF-α), total cholesterol (TC), low-density lipoprotein cholesterol (LDL) and triglyceride (TG) levels were observed in the probiotic group. The amelioration of total antioxidant status (TAS) was also observed. The 12-week supplementation of the multispecies probiotic (Ecologic^® BARIER) effectively reduced Hcy concentration, oxidative stress and inflammation, and improved the lipid profile. These multidirectional effects can potentially reduce cardiometabolic risks.

The Link between Homocysteine and Omega-3 Polyunsaturated Fatty Acid: Critical Appraisal and Future Directions

Omega-3 polyunsaturated fatty acids and B vitamins are linked to metabolic and degenerative disorders, such as cardiovascular disease and cognitive decline. In the last two decades, the interplay between B vitamins and omega-3 polyunsaturated fatty acids gained increasing attention. Expression control on enzymes involved in the pathway of homocysteine by polyunsaturated fatty acids has been proposed. The methylation process seems crucial for the metabolism of polyunsaturated fatty acids and their distribution within the body. This review summarizes the available data in humans about the link between homocysteine and omega-3 polyunsaturated fatty acids, with a special focus on the meta-analyses of randomized clinical trials. Even if the paucity of available information about the topic does not allow for definitive conclusions, a synergic action between polyunsaturated fatty acids and B vitamins may play a key role in regulating several metabolic pathways. This element could explain a stronger action on homocysteine levels when omega-3 polyunsaturated fatty acids and B vitamins are supplemented simultaneously. To date, a robust rationale of intervention to prevent metabolic diseases is lacking and could be beneficial for individual health and healthcare policy.

Gene interactions observed with the HDL-c blood lipid, intakes of protein, sugar and biotin in relation to circulating homocysteine concentrations in a group of black South Africans

Background

Elevated homocysteine (Hcy) is associated with several pathologies. Gene–diet interactions related to Hcy might be used to customize dietary advice to reduce disease incidence. To explore this possibility, we investigated interactions between anthropometry, biochemical markers and diet and single-nucleotide polymorphisms (SNPs) in relation to Hcy concentrations. Five SNPs of Hcy-metabolizing enzymes were analyzed in 2010 black South Africans.

Results

Hcy was higher with each additional methylenetetrahydrofolate reductase (MTHFR) C677T minor allele copy, but was lower in methionine synthase (MTR) 2756AA homozygotes than heterozygotes. Individuals harboring cystathionine β synthase (CBS) 833 T/844ins68 had lower Hcy concentrations than others. No interactive effects were observed with any of the anthropometrical markers. MTHFR C677T and CBS T833C/844ins68 homozygote minor allele carriers presented with lower Hcy as high density lipoprotein cholesterol (HDL-c) increased. Hcy concentrations were negatively associated with dietary protein and animal protein intake in the TT and TC genotypes, but positively in the CC genotype of CBS T833C/844ins68. Hcy was markedly higher in TT homozygotes of MTHFR C677T as added sugar intake increased. In CBS T833C/844ins68 major allele carriers, biotin intake was negatively associated with Hcy; but positively in those harboring the homozygous minor allele.

Conclusions

The Hcy–SNP associations are modulated by diet and open up the possibility of invoking dietary interventions to treat hyperhomocysteinemia. Future intervention trials should further explore the observed gene–diet and gene–blood lipid interactions.

The Impact of One Carbon Metabolism on Histone Methylation

The effect of one carbon metabolism on DNA methylation has been well described, bridging nutrition, metabolism, and epigenetics. This modification is mediated by the metabolite S-adenosyl methionine (SAM), which is also the methyl-donating substrate of histone methyltransferases. Therefore, SAM levels that are influenced by several nutrients, enzymes, and metabolic cofactors also have a potential impact on histone methylation. Although this modification plays a major role in chromatin accessibility and subsequently in gene expression in healthy or diseased states, its role in translating nutritional changes in chromatin structure has not been extensively studied. Here, we aim to review the literature of known mechanistic links between histone methylation and the central one carbon metabolism.

Deciphering the Link Between Hyperhomocysteinemia and Ceramide Metabolism in Alzheimer-Type Neurodegeneration

Aging is one of the strongest risk factor for Alzheimer's disease (AD). However, several data suggest that dyslipidemia can either contribute or serve as co-factors in AD appearance. AD could be examined as a metabolic disorder mediated by peripheral insulin resistance. Insulin resistance is associated with dyslipidemia, which results in increased hepatic ceramide generation. Hepatic steatosis induces pro-inflammatory cytokine activation which is mediated by the increased ceramides production. Ceramides levels increased in cells due to perturbation in sphingolipid metabolism and upregulated expression of enzymes involved in ceramide synthesis. Cytotoxic ceramides and related molecules generated in liver promote insulin resistance, traffic through the circulation due to injury or cell death caused by local liver inflammation, and because of their hydrophobic nature, they can cross the blood-brain barrier and thereby exert neurotoxic responses as reducing insulin signaling and increasing pro-inflammatory cytokines. These abnormalities propagate a cascade of neurodegeneration associated with oxidative stress and ceramide generation, which potentiate brain insulin resistance, apoptosis, myelin degeneration, and neuro-inflammation. Therefore, excess of toxic lipids generated in liver can cause neurodegeneration. Elevated homocysteine level is also a risk factor for AD pathology and is narrowly associated with metabolic diseases and non-alcoholic fatty liver disease. The existence of a homocysteine/ceramides signaling pathway suggests that homocysteine toxicity could be partly mediated by intracellular ceramide accumulation due to stimulation of ceramide synthase. In this article, we briefly examined the role of homocysteine and ceramide metabolism linking metabolic diseases and non-alcoholic fatty liver disease to AD. We therefore analyzed the expression of mainly enzymes implicated in ceramide and sphingolipid metabolism and demonstrated deregulation of de novo ceramide biosynthesis and S1P metabolism in liver and brain of hyperhomocysteinemic mice.

Prepregnancy Habitual Intakes of Total, Supplemental, and Food Folate and Risk of Gestational Diabetes Mellitus: A Prospective Cohort Study

OBJECTIVE

To identify novel modifiable risk factors of gestational diabetes mellitus (GDM) by examining the association between prepregnancy habitual folate intake and GDM risk.

RESEARCH DESIGN AND METHODS

The study included 14,553 women in the Nurses' Health Study II who reported at least one singleton pregnancy between the 1991 and 2001 questionnaires. Prepregnancy intakes of total folate, supplemental folate, and food folate were assessed using a food frequency questionnaire administered every 4 years. Incident GDM was ascertained from a self-reported physician diagnosis. Relative risks (RRs) of GDM were estimated using log-binomial models, with adjustment for demographic, lifestyle, and dietary factors.

RESULTS

Over the study follow-up, 824 incident GDM cases were reported among 20,199 pregnancies. Women with adequate total folate intake (≥400 μg/day) had an RR of GDM of 0.83 (95% CI 0.72, 0,95, P = 0.007) compared with women with inadequate intake (<400 μg/day). This association was entirely driven by supplemental folate intake. The RRs of GDM for 1-399, 400-599, and ≥600 μg/day of supplemental folate intake were 0.83, 0.77, and 0.70, respectively, compared with no supplemental folate intake (P _trend = 0.002). The association between supplemental folate intake and GDM risk largely persisted after additional adjustment for intake of multivitamins and other micronutrients, as well as among women who likely planned for the pregnancy.

CONCLUSIONS

Higher habitual intakes of supplemental folate before pregnancy were significantly associated with lower GDM risk. If confirmed, these findings indicate that prepregnancy folic acid supplementation could offer a novel and low-cost avenue to reduce GDM risk.

Impact of maternal BMI and gestational diabetes mellitus on maternal and cord blood metabolome: results from the PREOBE cohort study

AIMS

Maternal obesity and gestational diabetes mellitus (GDM) were frequently reported to be risk factors for obesity and diabetes in offspring. Our goal was to study the impact of maternal prepregnancy BMI (pBMI) and GDM on both maternal and cord blood metabolic profiles.

METHODS

We used LC-MS/MS to measure 201 metabolites comprising phospholipids (PL), amino acids, non-esterified fatty acids (NEFA), organic acids, acyl carnitines (AC), and Krebs cycle metabolites in maternal plasma at delivery and cord plasma obtained from 325 PREOBE study participants.

RESULTS

Several metabolites were associated with pBMI/GDM in both maternal and cord blood (p < 0.05), while others were specific to either blood sources. BMI was positively associated with leucine, isoleucine, and inflammation markers in both mother and offspring, while β-hydroxybutyric acid was positively associated only in cord blood. GDM showed elevated levels of sum of hexoses, a characteristic finding in both maternal and cord blood. Uniquely in cord blood of offspring born to GDM mothers, free carnitine was significantly lower with the same tendency observed for AC, long-chain NEFA, PL, specific Krebs cycle metabolites, and β-oxidation markers.

CONCLUSIONS

Maternal BMI and GDM are associated with maternal and cord blood metabolites supporting the hypothesis of transgenerational cycle of obesity and diabetes.

Genetic polymorphism of methylenetetrahydrofolate reductase is associated with insulin resistance in Egyptian women with polycystic ovary syndrome

BACKGROUND

A common polymorphism (677C to T; Ala to Val) in the methylenetetrahydrofolate reductase (MTHFR) gene is associated with decreased specific MTHFR activity and elevation of homocysteine. The present study aimed to investigate the association between a single nucleotide polymorphism (SNP) in the MTHFR 677C>T gene and insulin resistance in women with polycystic ovary syndrome (PCOS).

METHODS

Two-hundred patients with PCOS were included in this case-control study: 100 patients with insulin resistance and 100 patients without insulin resistance were genotyped by polymerase chain reaction-restriction fragment length polymorphism analysis.

RESULTS

The TT genotype for the MTHFR 677C>T polymorphism was significantly more frequent in PCOS patients with insulin resistance than in PCOS patients without insulin resistance (19% versus 6%, p = 0.002), whereas there was no significant difference between both groups for CT and there was a statistically significant increase in the T allele in PCOS patients with insulin resistance compared to PCOS patients without insulin resistance (p = 0.002, odds ratio = 1.95 and 95% confidence interval = 1. 29-2.93). Regarding the relationship between MTHFR 677C>T genotypes and the characteristics of insulin resistance in PCOS patients, we found that there was no significant difference in age, waist-hip ratio and total testosterone between the different genotypes of the MTHFR 677C>T polymorphism. The mean values for body mass index and the Homeostatic Model Assessment of Insulin Resistance were significantly higher in the TT genotype of MTHFR 677C>T compared to the CC genotype in PCOS patients with insulin resistance (p < 0.001).

CONCLUSIONS

We have demonstrated an association of the MTHFR 677C>T gene polymorphism with insulin resistance in Egyptian women with PCOS.

Hepatic accumulation of S-adenosylmethionine in hamsters with non-alcoholic fatty liver disease associated with metabolic syndrome under selenium and vitamin E deficiency

Progression of non-alcoholic fatty liver disease (NAFLD) in the context of metabolic syndrome (MetS) is only partially explored due to the lack of preclinical models. In order to study the alterations in hepatic metabolism that accompany this condition, we developed a model of MetS accompanied by the onset of steatohepatitis (NASH) by challenging golden hamsters with a high-fat diet low in vitamin E and selenium (HFD), since combined deficiency results in hepatic necroinflammation in rodents. Metabolomics and transcriptomics integrated analyses of livers revealed an unexpected accumulation of hepatic S-Adenosylmethionine (SAM) when compared with healthy livers likely due to diminished methylation reactions and repression of GNMT. SAM plays a key role in the maintenance of cellular homeostasis and cell cycle control. In agreement, analysis of over-represented transcription factors revealed a central role of c-myc and c-Jun pathways accompanied by negative correlations between SAM concentration, MYC expression and AMPK phosphorylation. These findings point to a drift of cell cycle control toward senescence in livers of HFD animals, which could explain the onset of NASH in this model. In contrast, hamsters with NAFLD induced by a conventional high-fat diet did not show SAM accumulation, suggesting a key role of selenium and vitamin E in SAM homeostasis. In conclusion, our results suggest that progression of NAFLD in the context of MetS can take place even in a situation of hepatic SAM excess and that selenium and vitamin E status might be considered in current therapies against NASH based on SAM supplementation.

Attenuation of utero-toxicity, metabolic dysfunction and inflammation by soy protein concentrate in rats exposed to fluoridated water: consequence of hyperlipidemia in parallel with hypohomocysteinemia

Lipid peroxidation and ROS generation are the pathogenesis of chronic fluoride toxicity, and its detrimental effects on human reproduction are noted drastically. The aim of the present study was to elucidate the defensive effects of soy protein concentrate (SPC) against sodium fluoride (NaF)-induced uterine dysfunction at biochemical and histological level. Rats were randomly distributed into four groups as control, NaF-treated (200 ppm), and SPC co-administered groups (20 mg and 40 mg/ 100 g body weight) for 16 days. SPC reversed the toxic effects of NaF. SPC significantly ameliorated the NaF-induced alterations of the antioxidant system in the uterus by decreasing lipid peroxidation products and by increasing antioxidant activities. SPC significantly counteracted the adverse effects of NaF on serum level of lactate dehydrogenase (LDH) and inflammatory markers Interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α) and nuclear factor kappa-B (NF-κB). Our results also explored that lipid profile was meaningfully altered due to NaF and also focused a diminution of circulating homocysteine (Hcy) and altered lipid profiles along with a diminished quantity of serum B₁₂ and B₉. However, both the doses of SPC reverted back serum levels of B₁₂, B₉, and Hcy status in similar fashion along with its corrective action on lipid profile. NaF-treated group exhibited a marked degree of reduction in the weights of ovary and uterus with an alteration of normal tissue histology and significant diminution in serum estradiol (ES) levels without fluctuating uterine estradiol receptor-α (ER-α). However, SPC restored the normal tissue histoarchitecture and also increased the functional efficiency and expression of the ER-α receptor by overturning the ES levels in NaF-treated rats. Moreover, both the doses of SPC were effective against NaF-induced alterations, although 40 mg SPC/100 g body weight had better efficacy in ameliorating the NaF-induced adverse effects on the uterus and ovary.

Identifying mechanisms of regulation to model carbon flux during heat stress and generate testable hypotheses

Understanding biological response to stimuli requires identifying mechanisms that coordinate changes across pathways. One of the promises of multi-omics studies is achieving this level of insight by simultaneously identifying different levels of regulation. However, computational approaches to integrate multiple types of data are lacking. An effective systems biology approach would be one that uses statistical methods to detect signatures of relevant network motifs and then builds metabolic circuits from these components to model shifting regulatory dynamics. For example, transcriptome and metabolome data complement one another in terms of their ability to describe shifts in physiology. Here, we extend a previously described linear-modeling based method used to identify single nucleotide polymorphisms (SNPs) associated with metabolic changes. We apply this strategy to link changes in sulfur, amino acid and lipid production under heat stress by relating ratios of compounds to potential precursors and regulators. This approach provides integration of multi-omics data to link previously described, discrete units of regulation into functional pathways and identifies novel biology relevant to the heat stress response, in addition to generating hypotheses.

Impaired Homocysteine Metabolism Associated with High Plasma Interleukin-17A Levels, a Pro-Atherogenic Marker, in an Endogamous Population of North India

Background

Impaired homocysteine metabolism (IHM; hyperhomocysteinemia) has been linked with many complex disorders like cardiovascular diseases and immunological disturbances. However, studies understanding IHM in light of pro- and anti- atherogeneic markers like Interleukin-17A & -10 (IL-17A & IL-10) and Forkhead box p3 (Foxp3, a master transcription factor) are scarce.

Aim

In our present study, we aimed to understand the relation of IHM with plasma IL-17A and IL-10 levels and Foxp3 mRNA expression in peripheral blood mononuclear cells (PBMCs) from an endogamous population (Jats of Haryana, North India) with high prevalence of IHM without the concurrence of significant adverse cardiovascular outcomes.

Methods

Forty (40) clinically healthy individuals, unrelated up to first cousins, were recruited and were subjected to demographic, physiological and anthropometric profiling, followed by intravenous blood sample collection (fasting) and lipid profiling. Plasma homocysteine levels were estimated and individuals with homocysteine levels ≥ 15umol/L and <15umol/L were categorized as the impaired homocysteine metabolism group (IHM, n=30) and normal homocysteine metabolism group (NHM, n=10) respectively. Plasma folate and vitamin B12 and MTHFR C677T (methylenetetrahydrofolate reductase) polymorphism were detected. Relative mRNA expression of Foxp3 in PBMCs (normalized to 18S) was quantitated using SyBR green technology. Plasma IL-10 & 17 levels were estimated by ELISA assays.

Results and Conclusions

None of the physiological, anthropometric and lipid variables were different between the two groups. Foxp3 mRNA expression levels were relatively lower, and plasma IL-10 levels were found to be comparable among IHM and NHM group. However, significantly higher IL-17A levels and relatively high LDL cholesterol levels were present in the IHM group as compared with NHM. Our findings suggest that the Jats of Haryana, North India, exhibiting high levels of homocysteine, might also carry the high IL-17A -pro-atherogenic marker, suggesting an increasing burden of pre-morbid condition. This apparently does not reach to significant mortality/morbidity attributed to the counter action or balancing act of IL-10 (an anti-atherogenic marker). This further suggests environment-influenced epigenetic control mechanisms of the targeted genes in the present population.

PEMT rs12325817 and PCYT1A rs7639752 polymorphisms are associated with betaine but not choline concentrations in pregnant women

Maternal metabolism during gestation may depend on nutrient intake but also on polymorphism of genes encoding enzymes involved in metabolism of different nutrients. Data on choline or carnitine metabolism in pregnant women are scarce. We hypothesized that (1) choline intake in Polish pregnant women is inadequate and (2) choline and carnitine metabolism would differ by genotype and nutritional status of pregnant women. One hundred three healthy Polish women aged 18 to 44 years in the third trimester of pregnancy were enrolled in the study. The average choline, folate, and carnitine intakes were 365 ± 14 mg/d, 1089 ± 859 μg, and 132 ± 8 mg/d, respectively. Most women did not achieve an adequate intake of choline. Average choline, betaine, trimethylamine oxide, l-carnitine, and acetylcarnitine concentrations were 10.64 ± 3.30 μmol/L, 14.43 ± 4.01 μmol/L, 2.01 ± 1.24 μmol/L, 12.73 ± 5.41 μmol/L, and 6.79 ± 3.82 μmol/L, respectively. Approximately 15% lower betaine concentrations were observed in the GG homozygotes of PEMT rs12325817 and in the GG homozygotes of PCYT1A rs7639752 than in the respective minor allele carriers. Birth weight was higher in the G allele homozygotes of the CHDH rs2289205 than in the minor allele carriers: GG: 3398 ± 64 g; GA+AA: 3193 ± 76 g. Our study shows that choline intake in Polish pregnant women is inadequate and that polymorphisms of PEMT rs12325817 and PCYT1A rs7639752 are associated with betaine but not choline concentrations.

The methylenetetrahydrofolate reductase genotype 677CT and non-alcoholic fatty liver disease have a synergistic effect on the increasing homocysteine levels in subjects from Chongqing, China

The methylenetetrahydrofolate reductase (MTHFR) genotypes 677CT and 677TT are associated with elevated serum homocysteine (Hcy) levels by means of lowering the activity of MTHFR, and the increase in serum Hcy may be linked to increased susceptibility to non-alcoholic fatty liver disease (NAFLD). However, there are contradictory reports of the relationship among the MTHFR 677CT gene polymorphism, Hcy, and NAFLD. Therefore, the aim of this study was to identify potential associations and interactions of either Hcy levels or the MTHFR 677CT gene polymorphism with the susceptibility to NAFLD in a Chinese population. The association between the MTHFR 677 CT gene polymorphism and Hcy levels was determined in 243 subjects with NAFLD and 388 healthy subjects without NAFLD using polymerase chain reaction-restriction fragment length polymorphism analysis and high-performance liquid chromatography. In subjects with NAFLD, there was no statistical difference in the genotypic and allelic frequencies of the MTHFR 677 CT gene polymorphism, while serum Hcy levels were significantly higher in subjects with NAFLD. Furthermore, these results strongly suggest that the MTHFR 677CT gene polymorphism and NAFLD have a potential synergistic effect on Hcy elevation, although the MTHFR 677CT gene polymorphism was not correlated with NAFLD in a Chinese population.

Genetically Determined Folate Deficiency Is Associated With Abnormal Hepatic Folate Profiles in the Spontaneously Hypertensive Rat

Increased levels of plasma cysteine are associated with obesity and metabolic disturbances. Our recent genetic analyses in spontaneously hypertensive rats (SHR) revealed a mutated Folr1 (folate receptor 1) as the quantitative trait gene associated with diminished renal Folr1 expression, lower plasma folate levels, hypercysteinemia, hyperhomocysteinemia and metabolic disturbances. To further analyse the effects of the Folr1 gene expression on folate metabolism, we used mass spectrometry to quantify folate profiles in the plasma and liver of an SHR-1 congenic strain, with wild type Folr1 allele on the SHR genetic background, and compared them with the SHR strain. In the plasma, concentration of 5-methyltetrahydrofolate (5mTHF) was significantly higher in SHR-1 congenic rats compared to SHR (60±6 vs. 42±2 nmol/l, P<0.01) and 5mTHF monoglutamate was the predominant form in both strains (>99 % of total folate). In the liver, SHR-1 congenic rats showed a significantly increased level of 5mTHF and decreased concentrations of dihydrofolate (DHF), tetrahydrofolate (THF) and formyl-THF when compared to the SHR strain. We also analysed the extent of folate glutamylation in the liver. Compared with the SHR strain, congenic wild-type Folr1 rats had significantly higher levels of 5mTHF monoglutamate. On the other hand, 5mTHF penta- and hexaglutamates were significantly higher in SHR when compared to SHR-1 rats. This inverse relationship of rat hepatic folate polyglutamate chain length and folate sufficiency was also true for other folate species. These results strongly indicate that the whole body homeostasis of folates is substantially impaired in SHR rats compared to the SHR-1 congenic strain and might be contributing to the associated metabolic disturbances observed in our previous studies.

Metabolic distress in lipid & one carbon metabolic pathway through low vitamin B-12: a population based study from North India

Background

Dyslipidemia and hyper-homocysteinemia are the major independent risk factors of cardio vascular disease. Deficiency of folate and vitamin B-12 are associated with both hyper-homocysteinemia and dyslipidemia. The aim of the study is to evaluate the relationship of homocysteine and its associated dietary determinant levels (Folate and Vitamin B-12) with lipids and obesity parameters (WC, BMI, WHR) in North Indian population.

Methods

The participants were recruited under a major government funded project through household survey covering 15 villages of Haryana, India. Participants were both males and females, between age group 30–65 years, from a north Indian community. Initially 1634 individuals were recruited, of which 1374 were considered for analysis as they were not found to be on any kind of medication for high blood pressure, CAD, diabetes or any other disorder, and had no missing data. 5 mL of intravenous blood sample was collected after obtaining written informed consent from the participants. Homocysteine, folate and vitamin B12 levels were estimated through Immulite 1000 by chemi-luminescence technique. Triglyceride, total cholesterol and HDL-C were estimated by spectrophotometry technique using commercial kits. The values for LDL and VLDL were calculated using Friedwald’s equation. Height, weight, waist circumference (WC), hip circumference (HC) was measured over light clothing. Statistical analysis for data was performed using SPSS 16.0 version.

Results

All the lipid indices, except HDL, showed a trend of negative correlation with homocysteine after controlling for confounders, though not significant. No association was found between obesity (WC, BMI, WHR) and homocysteine in the present study. Vitamin B-12 deficiency was significantly associated with both hyper-homocysteinemia and low HDL. Folate was found to have significantly reduced risk for high TC & LDL.

Conclusions

The “hcy-lipid” hypothesis does not seem to be complementing in the present studied population. The population is vulnerable to severe under-nutrition due to the association of vitamin B-12 with HDL, leading to metabolic disturbance in both the pathways; lipid and one carbon metabolic pathway. Co-factors such as ethnicity, cultural practices, and lifestyle & dietary habits must be considered while making public health policies to control diseases.

Electronic supplementary material

The online version of this article (10.1186/s12944-018-0748-y) contains supplementary material, which is available to authorized users.

Maternal Consumption of Low-Isoflavone Soy Protein Isolate Confers the Increased Predisposition to Alcoholic Liver Injury in Adult Rat Offspring

Offspring of female rats fed either a casein (CAS) diet or a low-isoflavone soy protein isolate (SPI) diet were compared in an animal model of chronic ethanol consumption to investigate whether maternal diet regulates the adaptive responses of offspring to postnatal ethanol exposure and potentially affects the development of liver disease in later life. Female rats were fed either a CAS or an SPI diet before mating, and during pregnancy and lactation. Male offspring from the same litter were pair-fed either a control or ethanol diet for six weeks (CAS/CON, CAS/EtOH, SPI/CON, and SPI/EtOH groups). Serum aminotransferase activities and hepatic inflammatory indicators were higher in the SPI/EtOH group than in the CAS/EtOH group. Ethanol consumption increased serum homocysteine levels, hepatic S-adenosylmethionine:S-adenosylhomocysteine ratio, and hepatic endoplasmic reticulum stress only in offspring of SPI-fed female rats. Total and high-density lipoprotein (HDL) cholesterol levels and mRNA levels of hepatic genes involved in HDL cholesterol assembly were reduced in the SPI group in response to ethanol consumption. In conclusion, offspring of SPI-fed female rats were more susceptible to the later development of alcoholic liver disease than offspring of CAS-fed female rats. Furthermore, maternal SPI consumption altered one-carbon metabolism and cholesterol metabolism of offspring fed an ethanol diet.