Homocysteine and cardiovascular disease: cause or effect?

Short-chain fatty acids (SCFAs) from gastrointestinal disorders, metabolism, epigenetics, central nervous system to cancer - A mini-review

Short-chain fatty acids (SCFAs), generated through microbial fermentation of dietary fibers and proteins in the gut, play a pivotal role in maintaining intestinal integrity, cellular function, and the immune response. SCFAs, including butyrate, acetate, and propionate, are absorbed in the colon or excreted through feces, contributing to essential physiological processes. Butyrate, a primary energy source for colonocytes, exhibits anti-inflammatory properties and regulates key pathways, such as nuclear factor-κB (NF-κB) inhibition. SCFAs' impact extends beyond the intestines, influencing the gut-brain axis, systemic circulation, and folate metabolism. A decline in colonic SCFAs has been linked to gastrointestinal diseases, emphasizing their clinical relevance, while their effects on immune checkpoints, such as ipilimumab, provide intriguing prospects for cancer therapy. This mini-review explores SCFAs' diverse roles, shedding light on their significance in health and potential implications for disease management. Understanding SCFAs' intricate mechanisms enhances our knowledge of their therapeutic potential and highlights their emerging importance in various physiological contexts.

Tangshen formula improves diabetic nephropathy in STZ-induced diabetes rats fed with hyper-methionine by regulating the methylation status of kidney

BACKGROUND

The objective of this study was to examine and analyze differential methylation profiles in order to investigate the influence of hyper-methioninemia (HM) on the development of diabetic nephropathy (DN). Male Wistar rats, aged eight weeks and weighing 250-300 g, were randomly assigned into four groups: a control group (Healthy, n = 8), streptozocin-induced rats (STZ group, n = 8), HM + STZ group (n = 8), and the Tangshen Formula (TSF) treatment group (TSF group, n = 8). Blood glucose levels and other metabolic indicators were monitored before treatment and at four-week intervals until 12 weeks. Total DNA was extracted from the aforementioned groups, and DNA methylation landscapes were analyzed via reduced representative bisulfite sequencing.

RESULTS

Both the STZ group and HM + STZ group exhibited increased blood glucose levels and urinary albumin/creatinine ratios in comparison with the control group. Notably, the HM + STZ group exhibited a markedly elevated urinary albumin/creatinine ratio (411.90 ± 88.86 mg/g) compared to the STZ group (238.41 ± 62.52 mg/g). TSF-treated rats demonstrated substantial reductions in both blood glucose levels and urinary albumin/creatinine ratios in comparison with the HM + STZ group. In-depth analysis of DNA methylation profiles revealed 797 genes with potential therapeutic effects related to TSF, among which approximately 2.3% had been previously reported as homologous genes.

CONCLUSION

While HM exacerbates DN through altered methylation patterns at specific CpG sites, TSF holds promise as a viable treatment for DN by restoring abnormal methylation levels. The identification of specific genes provides valuable insights into the underlying mechanisms of DN pathogenesis and offers potential therapeutic targets for further investigation.

Non-Conventional Risk Factors: "Fact" or "Fake" in Cardiovascular Disease Prevention?

Cardiovascular diseases (CVDs), such as arterial hypertension, myocardial infarction, stroke, heart failure, atrial fibrillation, etc., still represent the main cause of morbidity and mortality worldwide. They significantly modify the patients' quality of life with a tremendous economic impact. It is well established that cardiovascular risk factors increase the probability of fatal and non-fatal cardiac events. These risk factors are classified into modifiable (smoking, arterial hypertension, hypercholesterolemia, low HDL cholesterol, diabetes, excessive alcohol consumption, high-fat and high-calorie diet, reduced physical activity) and non-modifiable (sex, age, family history, of previous cardiovascular disease). Hence, CVD prevention is based on early identification and management of modifiable risk factors whose impact on the CV outcome is now performed by the use of CV risk assessment models, such as the Framingham Risk Score, Pooled Cohort Equations, or the SCORE2. However, in recent years, emerging, non-traditional factors (metabolic and non-metabolic) seem to significantly affect this assessment. In this article, we aim at defining these emerging factors and describe the potential mechanisms by which they might contribute to the development of CVD.

Association between body fat composition and hyperhomocysteinemia in the analysis of the baseline data of the Northwest China Natural Population Cohort: Ningxia Project (CNC-NX)

The authors conducted an observational study to explore the association between body fat composition and the risk of hyperhomocysteinemia (HHcy) and their combined effect on the risk of developing cardiovascular disease (CVD). Adults aged 18-74 years from the Northwest China Natural Population Cohort: Ningxia Project (CNC-NX) were recruited in this study. Association between body fat composition and HHcy was evaluated by logistic regression model. Restricted cubic spline was used to find nonlinear association. The impact of the interaction between HHcy and body fat composition on CVD was evaluated using the addition interaction model and mediation effect model. In total, 16 419 participants were included in this research. Body fat percentage, visceral fat level, and abdominal fat thickness were positively associated with overall HHcy (p for trend < .001). Adjusted odds ratios (ORs) in quarter 4 were 1.181 (95% CI: 1.062, 1.313), 1.202 (95% CI: 1.085, 1.332), and 1.168 (95% CI: 1.055, 1.293) for body fat percentage, visceral fat level, and abdominal fat thickness, respectively, compared with those in quarter 1. Subgroup analysis indicated age, estimated glomerular filtration rate (eGFR), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), and CVD were the interaction factors of body fat percentage, visceral fat level, abdominal fat thickness with HHcy (all p for interaction < .05). ORs of CVD were higher in participants with HHcy and high body fat. Body fat composition was positively associated with HHcy, indicating that reducing body, abdominal, and visceral fat content may lower the risk of HHcy and CVD.

Catalytic Mechanism of Pyridoxal 5'-Phosphate-Dependent Aminodeoxychorismate Lyase: A Computational QM/MM Study

Aminodeoxychorismate lyase (ADCL) is a kind of pyridoxal-5'-phosphate (PLP)-dependent enzyme that catalyzes the conversion of 4-amino-4-deoxychorismate (ADC) to p-aminobenzoate (PABA), which is a key step for the biosynthesis of folate. To illuminate the reaction details at the atomistic level, an enzyme-substrate reactant model has been constructed, and QM/MM calculations have been performed. Our calculation results reveal that the overall catalytic cycle contains 11 elementary steps, which can be described by three stages, including the transamination reaction of PLP, the release of pyruvate and aromatization of ADC, and the recovery to the initial aldimine. During the reaction, a series of intramolecular proton transfer are involved, which are the key for the C-N bond formation and cleavage as well as the aromatization of the ADC ring. In addition to forming the Schiff base with the pocket residue Lys251 and substrate in the internal aldimine and the external aldimine, respectively, the coenzyme PLP also plays a critical role in the intramolecular proton transfer by employing its hydroxyl oxygen anion and phosphate group. These findings may provide useful information for further understanding the catalytic mechanism of other PLP-dependent enzymes.

Association between Methylene-Tetrahydrofolate Reductase C677T Polymorphism and Human Immunodeficiency Virus Type 1 Infection in Morocco

Human immunodeficiency virus type 1 (HIV-1) infection varies substantially among individuals. One of the factors influencing viral infection is genetic variability. Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism is a genetic factor that has been correlated with different types of pathologies, including HIV-1. The MTHFR gene encodes the MTHFR enzyme, an essential factor in the folate metabolic pathway and in maintaining circulating folate and methionine at constant levels, thus preventing the homocysteine accumulation. Several studies have shown the role of folate on CD4+ T lymphocyte count among HIV-1 subjects. In this case-control study we aimed to determine the association between the MTHFR C677T polymorphism and HIV-1 infection susceptibility, AIDS development, and therapeutic outcome among Moroccans. The C677T polymorphism was genotyped by polymerase chain reaction followed by fragment length polymorphism digestion in 214 participants living with HIV-1 and 318 healthy controls. The results of the study revealed no statistically significant association between MTHFR C677T polymorphism and HIV-1 infection (P > .05). After dividing HIV-1 subjects according to their AIDS status, no significant difference was observed between C677T polymorphism and AIDS development (P > .05). Furthermore, regarding the treatment response outcome, as measured by HIV-1 RNA viral load and CD4+ T cell counts, no statistically significant association was found with MTHFR C677T polymorphism. We conclude that, in the genetic context of the Moroccan population, MTHFR C677T polymorphism does not affect HIV-1 infection susceptibility, AIDS development, or response to treatment. However, more studies should be done to investigate both genetic and nutritional aspects for more conclusive results.

Agri-Food Waste from Apple, Pear, and Sugar Beet as a Source of Protective Bioactive Molecules for Endothelial Dysfunction and Its Major Complications

Endothelial damage is recognized as the initial step that precedes several cardiovascular diseases (CVD), such as atherosclerosis, hypertension, and coronary artery disease. It has been demonstrated that the best treatment for CVD is prevention, and, in the frame of a healthy lifestyle, the consumption of vegetables, rich in bioactive molecules, appears effective at reducing the risk of CVD. In this context, the large amount of agri-food industry waste, considered a global problem due to its environmental and economic impact, represents an unexplored source of bioactive compounds. This review provides a summary regarding the possible exploitation of waste or by-products derived by the processing of three traditional Italian crops-apple, pear, and sugar beet-as a source of bioactive molecules to protect endothelial function. Particular attention has been given to the bioactive chemical profile of these pomaces and their efficacy in various pathological conditions related to endothelial dysfunction. The waste matrices of apple, pear, and sugar beet crops can represent promising starting material for producing "upcycled" products with functional applications, such as the prevention of endothelial dysfunction linked to cardiovascular diseases.

Hyperhomocysteinemia in acute hepatic porphyria (AHP) and implications for treatment with givosiran

INTRODUCTION

Homocysteine is a sulfur-containing amino acid formed in the intermediary metabolism of methionine. Amino acid metabolism and heme biosynthesis pathways are complexly intertwined. Plasma homocysteine elevation, hyperhomocysteinemia (HHcy), has been reported in patients with acute hepatic porphyria (AHP), a family of rare genetic disorders caused by defects in hepatic heme biosynthesis.

AREAS COVERED

This article summarizes published case series in which givosiran, a subcutaneously administered small interfering RNA approved for AHP treatment, appeared to exacerbate dysregulated homocysteine metabolism in patients with AHP. A comprehensive exploratory analysis of ENVISION trial data demonstrated that on a population level, givosiran increased homocysteine but with wide interpatient variations, and there is no proof of correlations between HHcy and changes in efficacy or safety of givosiran.

EXPERT OPINION

The strong correlation and co-increase of homocysteine and methionine suggest that HHcy associated with givosiran is likely attributable to the impaired trans-sulfuration pathway catalyzed by cystathionine β-synthase, which uses vitamin B6 as a cofactor. Data-based consensus supports monitoring total plasma homocysteine and vitamin B6, B12, and folate levels before and during givosiran treatment; supplementing with pyridoxine/vitamin B6 in patients with homocysteine levels >100 μmol/L; and involving patients with homocysteine levels >30 μmol/L in decisions to supplement.

High-Level 5-Methyltetrahydrofolate Bioproduction in Bacillus subtilis by Combining Modular Engineering and Transcriptomics-Guided Global Metabolic Regulation

5-Methyltetrahydrofolate (5-MTHF) is the predominant folate form in human plasma, which has been widely used as a nutraceutical. However, the microbial synthesis of 5-MTHF is currently inefficient, limiting green and sustainable 5-MTHF production. In this study, the Generally Regarded As Safe (GRAS) microorganism Bacillus subtilis was engineered as the 5-MTHF production host. Three precursor supply modules were first optimized by modular engineering for strengthening the supply of guanosine-5-triphosphate (GTP) and p-aminobenzoic acid (pABA). Next, the impact of genome-wide gene expression on 5-MTHF biosynthesis was evaluated using transcriptome analyses, which identified key genes for 5-MTHF production. The effects of potential genes on 5-MTHF synthesis were verified by observing the genes' up-regulated by strong promoter P₅₆₆ and those down-regulated by inhibition through the clustered regularly interspaced short palindromic repeat interference (CRISPRi). Finally, a key gene for improved 5-MTHF biosynthesis, comGC, was integrated into the genome of modular engineered strain B89 for its overexpression and facilitating efficient 5-MTHF synthesis, reaching 3.41 ± 0.10 mg/L with a productivity of 0.21 mg/L/h, which was the highest level achieved by microbial synthesis. The engineered 5-MTHF-producing B. subtilis developed in this work lays the foundation of further enhancing 5-MTHF production by microbial fermentation, which can be used for isolation and purification of 5-MTHF as food and nutraceutical ingredients.

Effects of folate supplementation on recurrence and metabolic status of cervical intraepithelial neoplasia grade 2/3 in overweight and obese women: a randomized double-blind placebo-controlled trial

BACKGROUND AND OBJECTIVE

Inconsistent evidence showed that folate supplementation may be associated with reduced risk of cancer due to improved metabolic profiles and reduced markers of oxidative stress and inflammation. The aim of this investigation was to quantify the effects of folate supplementation on the recurrence and other metabolic factors of women with cervical intraepithelial neoplasia grade 2/3 (CIN2/3).

METHODS

This randomized, double-blind, placebo-controlled clinical trial was performed among 60 overweight/obese women with CIN2/3. Definitive CIN2/3 confirmation was done via biopsy, pathological diagnosis, as well as colposcopy. Participants were randomly assigned to the intervention group to take 5 mg/day folate supplements or placebo group (n = 30 in each group) for 12 weeks.

RESULTS

The results of the current study showed a non-significant decrease in recurrence of CIN2/3 in the folate group in comparison with the placebo group (3.3% vs. 16.7%, P = 0.08). Compared with the placebo, folate supplementation significantly decreased plasma homocysteine (Hcy) levels (P < 0.001), serum insulin values (in the crude model) (P = 0.01), and homeostasis model assessment of insulin resistance (P = 0.01). Also, folate supplementation resulted in a significant improvement in the quantitative insulin sensitivity check index (P = 0.002) and total antioxidant capacity (P = 0.04) and a significant reduction in high-sensitivity C-reactive protein (P = 0.015) in comparison with the placebo group.

CONCLUSIONS

In conclusion, folate supplementation for 12 weeks among overweight/obese women with CIN2/3 showed a non-significant decrease in its recurrence and had beneficial effects on insulin sensitivity, inflammation, and oxidative stress markers.

Probiotic Potential of a Folate-Producing Strain Latilactobacillus sakei LZ217 and Its Modulation Effects on Human Gut Microbiota

Folate is a B-vitamin required for DNA synthesis, methylation, and cellular division, whose deficiencies are associated with various disorders and diseases. Currently, most folic acid used for fortification is synthesized chemically, causing undesirable side effects. However, using folate-producing probiotics is a viable option, which fortify folate in situ and regulate intestinal microbiota. In this study, the folate production potential of newly isolated strains from raw milk was analyzed by microbiological assay. Latilactobacillus sakei LZ217 showed the highest folate production in Folic Acid Assay Broth, 239.70 ± 0.03 ng/μL. The folate produced by LZ217 was identified as 5-methyltetrahydrofolate. LZ217 was tolerant to environmental stresses (temperature, pH, NaCl, and ethanol), and was resistant to gastrointestinal juices. Additionally, the in vitro effects of LZ217 on human gut microbiota were investigated by fecal slurry cultures. 16S rDNA gene sequencing indicated that fermented samples containing LZ217 significantly increased the abundance of phylum Firmicutes and genus Lactobacillus, Faecalibacterium, Ruminococcus 2, Butyricicoccus compared to not containing. Short-chain fatty acids (SCFAs) analysis revealed that LZ217 also increased the production of butyric acid by fermentation. Together, L. sakei LZ217 could be considered as a probiotic candidate to fortify folate and regulate intestinal microecology.

Association between plasma S-adenosylmethionine and risk of mortality in patients with coronary artery disease: A cohort study

BACKGROUND

S-adenosylmethionine (SAM) as methyl donors participates in methylation and is converted into S-adenosylhomocysteine (SAH), which is a precursor of homocysteine. Increased plasma SAH and homocysteine are associated with increased risk of cardiovascular disease. However, the relation of plasma SAM with cardiovascular risk is still unclear.

OBJECTIVES

To determine the relation between plasma SAM and risk of mortality among patients with coronary artery disease (CAD).

METHODS

Baseline plasma SAM concentrations were measured in 1553 patients with CAD from the Guangdong Coronary Artery Disease Cohort between October 2008 and December 2011. Proportional hazards Cox analyses were performed to ascertain associations between SAM and risk of all-cause and cardiovascular mortality.

RESULTS

After a median follow-up of 9.2 (IQR: 8.5-10.2) y, of 1553 participants, 321 had died, including 227 deaths from cardiovascular diseases. Patients in the lowest quartile of SAM concentrations had a higher risk of all-cause death (HR, 1.59; 95% CI: 1.14, 2.21) and cardiovascular death (HR, 2.14; 95% CI: 1.41, 3.27) than those in the highest quartile in multivariable adjusted analysis. Each 1-SD decrease in the SAM concentration remained associated with a 42% greater risk of total death (HR, 1.42; 95% CI: 1.23, 1.64) and a 66% higher risk of cardiovascular death (HR, 1.66; 95% CI: 1.37, 2.01) after fully adjusting for other cardiovascular risk factors. Furthermore, each 1-SD decrease in plasma SAM/SAH ratio, as the methylation index, was also inversely associated with the risk of all-cause (HR, 1.80; 95% CI: 1.42, 2.29) and cardiovascular mortality (HR, 1.68; 95% CI: 1.29, 2.19) in fully adjusted analyses.

CONCLUSIONS

Our data show a significant inverse relation between plasma SAM and risk of mortality in patients with CAD after adjustment for homocysteine, SAH, and other cardiovascular disease risk factors.

Multiple roles of haem in cystathionine β-synthase activity: implications for hemin and other therapies of acute hepatic porphyria

The role of haem in the activity of cystathionine β-synthase (CBS) is reviewed and a hypothesis postulating multiple effects of haem on enzyme activity under conditions of haem excess or deficiency is proposed, with implications for some therapies of acute hepatic porphyrias. CBS utilises both haem and pyridoxal 5′-phosphate (PLP) as cofactors. Although haem does not participate directly in the catalytic process, it is vital for PLP binding to the enzyme and potentially also for CBS stability. Haem deficiency can therefore undermine CBS activity by impairing PLP binding and facilitating CBS degradation. Excess haem can also impair CBS activity by inhibiting it via CO resulting from haem induction of haem oxygenase 1 (HO 1), and by induction of a functional vitamin B₆ deficiency following activation of hepatic tryptophan 2,3-dioxygenase (TDO) and subsequent utilisation of PLP by enhanced kynurenine aminotransferase (KAT) and kynureninase (Kynase) activities. CBS inhibition results in accumulation of the cardiovascular risk factor homocysteine (Hcy) and evidence is emerging for plasma Hcy elevation in patients with acute hepatic porphyrias. Decreased CBS activity may also induce a proinflammatory state, inhibit expression of haem oxygenase and activate the extrahepatic kynurenine pathway (KP) thereby further contributing to the Hcy elevation. The hypothesis predicts likely changes in CBS activity and plasma Hcy levels in untreated hepatic porphyria patients and in those receiving hemin or certain gene-based therapies. In the present review, these aspects are discussed, means of testing the hypothesis in preclinical experimental settings and porphyric patients are suggested and potential nutritional and other therapies are proposed.

Using a 3-hydroxyflavone derivative as a fluorescent probe for the indirect determination of aminothiols separated by ion-pair HPLC

Homocysteine, cysteine, cysteinyl-glycine, and glutathione are significant biological aminothiols (ATs) that are marker-molecules in Down syndrome, Alzheimer's disease, or have been implicated as risk factors in atherosclerosis and other vascular diseases, and therefore rapid determination of these molecules is desirable. After reduction of the disulfides, a widely used method utilizes derivatization with ammonium 7-fluorobenzo-2-oxa-1,3-diazole-4-sulfonate (SBD-F) as a fluorogenic probe prior to reversed-phase HPLC separation followed by fluorescence detection. The traditional HPLC determination of ATs is time consuming and economically expensive. We have developed an ion-pair HPLC method coupled with indirect fluorescence detection after post-column reaction with a 2,4-dinitrobenzenesulfonate derivative of a 3-hydroxyflavone. The accuracy, precision, post-column temperature and residence time, and limit-of-detection were evaluated. Sample throughput and reduced sample preparation time of over an hour for the existing methods to less than 20 minutes for the new method is also demonstrated. No statistical differences in HCy, Cys, or Cys-Gly determinations in plasma samples were observed between our method and the traditional HPLC method.

Homocysteine-Lowering Interventions in Chronic Kidney Disease

The incidence of cardiovascular events and mortality is higher in patients with chronic kidney disease (CKD) compared to the general population. Homocysteine (Hcy) appears to be an independent risk factor for cardiovascular diseases in general populations and patients with CKD. Further, hyperhomocysteinemia can cause endothelial damage and increase the activity and production of coagulation factors, and its prevalence among patients with end-stage renal disease is approximately 85%-100%. Most treatments, which lower Hcy levels and have been considered in previous studies, include folic acid, B vitamins, omega-3 fatty acids, and N-acetylcysteine. However, the effect of therapies that can decrease Hcy levels and thus cardiovascular events in these patients is still unclear. The results are conflicting and require further investigation. To guide treatment decisions and improve patient outcomes, multiple databases were searched, including Web of Science, PubMed, and Medline to summarize the available evidence (i.e., clinical trial and meta-analyses) on Hcy-lowering interventions and cardiovascular events.

Curcumin can prevent the loss of sinoatrial node cells in methionine-treated rats: A stereological study

Methionine (MET) rich diets, smoking, coffee and alcohol consumption, low physical activity, and aging are related to high plasma concentrations of homocysteine, which can jeopardize the heart health. Although hyperhomocysteinemia has been considered a recognized risk factor for cardiac dysrhythmia, the structural changes of the conductive system, including Sinoatrial (SA) node of the heart involved in the disorder, have not been completely clarified. Curcumin is the main component of turmeric and has shown some cardioprotective effects. This study aimed to evaluate the effect of curcumin on the structural changes of the SA node in L-MET-treated rats. These alterations were evaluated by means of stereological techniques, namely cavalieri principle for volume estimation and optical disector counting technique for cell counting. Both techniques used two-dimensional images for obtaining three-dimensional parameters. The rats were divided into four groups, including control, MET-treated (1 g/kg/day), curcumin-treated, (100 mg/kg/day), and MET + curcumin. The treatments were performed for 28 days. On the final day, SA nodes were dissected out for stereological investigation. Compared to the control rats, the volume of SA node, total volume of grape-like cell clusters, and number of SA node cells were respectively decreased by 42%, 34%, and 37% in the MET-treated group (p < 0.04). However, collagen density remained constant in all the study groups. Furthermore, treatment with curcumin could protect the SA node from cellular decline in the MET + curcumin group (p < 0.01). It can be concluded that curcumin could prevent the structural changes of the SA node in the rats treated with methionine.

A high methionine and low folate diet alters glucose homeostasis and gut microbiome

Hyperhomocysteinemia (HHcy) is considered as a risk factor for several complications, including cardiovascular and neurological disorders. A high methionine low folate (HMLF) diet chronically causes HHcy by accumulating homocysteine in the systemic circulation. Elevated Hcy level is also associated with the incidence of diabetes mellitus. However, very few studies focus on the impact of HMLF diet on glucose homeostasis, and that on gut microbiome profile. HHcy was induced by feeding C57BL/6 mice a HMLF diet for 8 weeks. The HMLF diet feeding resulted in a progressive body weight loss, and development of slight glucose intolerance and insulin resistance in HHcy mice. Notably, the HMLF diet alters the gut microbiome profile and increases the relative abundance of porphyromonadaceae family of bacteria in HHcy mice. These findings provide new insights into the roles of dysregulated glucose homeostasis and gut flora in the pathogenesis of HHcy-related complications.

Correlation between plasma homocysteine and first myocardial infarction in young patients: Case-control study in Constanta County, Romania

An elevated level of total plasma homocysteine has been associated with a higher risk of atherosclerosis and coronary heart disease. The aim of our research was to study the relation between homocysteine and myocardial infarction (MI) in young patients. We conducted a case-control study in Constanţa County, Romania including 61 patients, divided in two groups. The first group, the MI group, consisted of 28 patients, male (67.9%) and female (32.1%) aged less than 45 years who were consecutively admitted to the Intensive Coronary Care Unit of the Emergency County Hospital of Constanţa from September 1, 2017 to August 31, 2018 (12 months), with an established diagnosis of first acute MI. The second group, the control group, included 33 patients, male (75.8%) and female (24.2%) aged less than 45 years, with cardiovascular risk factors and/or stable angina pectoris that were consecutively addressed for ambulatory cardiac evaluation at the Outpatient Clinic of Emergency County Hospital of Constanţa during the same period. Fasting plasma homocysteine was determined in both groups, within 24 h after MI onset, respectively after first cardiac exam in the controls. High homocysteine was statistically confirmed to be a risk factor in the study group, especially in association with smoking, chronic kidney disease (CKD), and to a lesser extent with diabetes mellitus (DM) and hypertension. Data analysis was performed using IBM SPSS Statistics 23. The procedures used included descriptive statistics, parametric statistical tests (Independent sample t-test), non-parametric statistical tests [Chi-square test of the association, with the evaluation of odds ratio (OR)]; the significance level used in the analysis (P-value) was 0.05. After adjusting for variables, our study results pointed out a strong association between plasma homocysteine and first acute MI among young patients, emphasising plasma homocysteine as a possible risk factor for myocardial infarction.

Sulfur-Containing Amino Acids and Lipid Metabolism

The metabolism of methionine and cysteine in the body tissues determines the concentrations of several metabolites with various biologic activities, including homocysteine, hydrogen sulfide (H2S), taurine, and glutathione. Hyperhomocysteinemia, which is correlated with lower HDL cholesterol in blood in volunteers and animal models, has been associated with an increased risk for cardiovascular diseases. In humans, the relation between methionine intake and hyperhomocysteinemia is dependent on vitamin status (vitamins B-6 and B-12 and folic acid) and on the supply of other amino acids. However, lowering homocysteinemia by itself is not sufficient for decreasing the risk of cardiovascular disease progression. Other compounds related to methionine metabolism have recently been identified as being involved in the risk of atherosclerosis and steatohepatitis. Indeed, the metabolism of sulfur amino acids has an impact on phosphatidylcholine (PC) metabolism, and anomalies in PC synthesis due to global hypomethylation have been associated with disturbances of lipid metabolism. In addition, impairment of H2S synthesis from cysteine favors atherosclerosis and steatosis in animal models. The effects of taurine on lipid metabolism appear heterogeneous depending on the populations of volunteers studied. A decrease in the concentration of intracellular glutathione, a tripeptide involved in redox homeostasis, is implicated in the etiology of cardiovascular diseases and steatosis. Last, supplementation with betaine, a compound that allows remethylation of homocysteine to methionine, decreases basal and methionine-stimulated homocysteinemia; however, it adversely increases plasma total and LDL cholesterol. The study of these metabolites may help determine the range of optimal and safe intakes of methionine and cysteine in dietary proteins and supplements. The amino acid requirement for protein synthesis in different situations and for optimal production of intracellular compounds involved in the regulation of lipid metabolism also needs to be considered for dietary attenuation of atherosclerosis and steatosis risk.

Cystathionine beta synthase regulates mitochondrial dynamics and function in endothelial cells

Mutations in the human cystathionine beta synthase (CBS) gene are known to cause endothelial dysfunction responsible for cardiovascular and neurovascular diseases. CBS is the predominant hydrogen sulfide (H2 S)-producing enzyme in endothelial cells (ECs). Recently, H2 S was shown to attenuate ROS and improve mitochondrial function. Mitochondria are metabolic organelles that actively transform their ultrastructure to mediate their function. Therefore, we questioned whether perturbation of CBS/H2 S activity could drive mitochondrial dysfunction via mitochondrial dynamics in ECs. Here we demonstrate that silencing CBS induces mitochondria fragmentation, attenuates efficient oxidative phosphorylation, and decreases EC function. Mechanistically, CBS silencing significantly elevates ROS production, thereby leading to reduced mitofusin 2 (MFN2) expression, decouple endoplasmic reticulum-mitochondria contacts, increased mitochondria fission, enhanced receptor-mediated mitophagy, and increased EC death. These defects were significantly rescued by the treatment of H2 S donors. Taken together our data highlights a novel signaling axis that mechanistically links CBS with mitochondrial function and ER-mitochondrial tethering and could be considered as a new therapeutic approach for the intervention of EC dysfunction-related pathologies.

Peripheral neuropathy in Parkinson's disease

Peripheral neuropathy (PN) is a common neurological problem defined as a dysfunction of sensory, motor, and autonomic nerves. The presence of peripheral neuropathy has recently been noticed in Parkinson's disease (PD) This comorbidity is concerning as it increases the burden on patients whose motor functions are previously compromised. A comprehensive computer-based literature review utilizing multiple peer-reviewed databases (e.g., Embase, PsycINFO, CINAHL, etc.) was conducted. There is evidence for the utility of robust diagnostic criteria to distinguish between large fiber neuropathy (LFN) and small fiber neuropathy (SFN). Some studies have established links between prolonged L-DOPA exposure and prevalence with increased levels of homocysteine (HCY) and methylmalonic acid (MMA) as pathological underlying mechanisms. PN in PD patients with relatively truncated exposure to L-DOPA therapy may have underlying mutations in the Parkin and MHTFR gene or separate mitochondrial disorders. Vitamin B12 and cobalamin deficiencies have also been implicated as drivers of PN. Accumulation of phosphorylated α-synuclein is another central feature in PN and deems urgent exploration via large cohort studies. Importantly, these underlying mechanisms have been linked to peripheral denervation. This review delves into the potential treatments for PN targeting B12 deficiencies and the use of COMT inhibitors along with other novel approaches. Avenues of research with powerful randomized controlled and long-term cohort studies exploring genetic mechanisms and novel treatment pathways is urgently required to alleviate the burden of disease exerted by PN on PD.

Effects of methionine synthase and methionine synthase reductase polymorphisms on hypertension susceptibility

BACKGROUND

Polymorphisms of methylenetetrahydrofolate reductase (MTHFR) gene are strongly associated with hypertension incidence, although such association is inconsistent among ethnicities studied. However, effects of polymorphisms of other genes related to folate metabolism besides MTHFR on hypertension susceptibility are not well known yet.

OBJECTIVE

The aim of this study was to elucidate whether methionine synthase (MTR) 2756A>G and methionine synthase reductase (MTRR) 66A>G polymorphisms might be associated with risks of hypertension susceptibility in the Korean population.

METHODS

Genotyping of these two polymorphisms was performed for 232 hypertensive patients and 247 unrelated healthy controls using polymerase chain reaction-restriction fragment length polymorphism technique.

RESULTS

In the present study, mutations of MTR 2756A>G and MTRR 66A>G polymorphisms were associated with increased and decreased susceptibility to hypertension, respectively. Allele combinations from these two polymorphisms were also related to hypertension prevalence. When polymorphism data were stratified according to clinical components of hypertension, The G allele of MTR 2756A>G polymorphism was significantly associated with an increased risk of hypertension in subjects with BMI < 26.1 kg/m² (P = 0.004), WC < 87.2 in. (P = 0.021), FBG < 95.5 mg/dL (P = 0.011), triglyceride < 133.5 mg/dL (P = 0.034), and HDL-cholesterol < 52.2 mg/dL (P = 0.036). The G allele of MTRR 66A>G polymorphism was significantly associated with a decreased risk of hypertension in subjects with WC ≥ 87.2 in. (P = 0.029), FBG ≥ 95.5 mg/dL (P = 0.032) and triglyceride ≥ 133.5 mg/dL (P = 0.027).

CONCLUSION

MTR 2756A>G and MTRR 66A>G polymorphisms related to folate metabolism might be genetic markers for risk of hypertension in the Korean population.

High-resolution metabolomics study revealing l-homocysteine sulfinic acid, cysteic acid, and carnitine as novel biomarkers for high acute myocardial infarction risk

BACKGROUND

Identifying changes in serum metabolites before the occurrence of acute myocardial infarction (AMI) is an important approach for finding novel biomarkers of AMI.

METHODS

In this prospective cohort study, serum samples obtained from patients at risk of AMI (n = 112) and non-risk controls (n = 89) were tested using high-resolution metabolomics (HRM). Partial least-squares discriminant analysis (PLS-DA), along with univariate analysis using a false discovery rate (FDR) of q = 0.05 were performed to discriminate metabolic profiles and to determine significantly different metabolites between healthy control and AMI risk groups.

RESULTS

PLS-DA significantly separated the AMI risk sera from control sera. The metabolites associated with amino acid biosynthesis, 2-oxocarboxylic acid, tryptophan, and amino sugar and nucleotide sugar metabolism pathways were mainly elevated in patients at risk of AMI. Further validation and quantification by MS/MS showed that tryptophan, carnitine, L-homocysteine sulfinic acid (L-HCSA), and cysteic acid (CA) were upregulated, while L-cysteine and L-cysteine sulfinic acid (L-CSA) were downregulated, specifically among AMI risk sera. Additionally, these discriminant metabolic profiles were not related to hypertension, smoking or alcoholism.

CONCLUSION

In conclusion, detecting upregulated L-HCSA and CA along with carnitine among patients at risk for AMI could serve as promising non-invasive biomarkers for early AMI detection.

Association of MTHFR C677T polymorphism with elevated homocysteine level and disease development in vitiligo

Increasing evidence on the association of MTHFR gene polymorphism and serum homocysteine levels with autoimmune diseases such as vitiligo has made the MTHFR gene a very interesting candidate to be evaluated in different ethnicities and populations. We aimed to evaluate the levels of serum homocysteine and vitamin B12 and their associations with MTHFR C677T polymorphism in the Iranian population. This case-control study included 104 patients with vitiligo and 100 age- and sex-matched healthy control subjects. Serum vitamin B12 and homocysteine levels were measured by a chemiluminescence assay. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis was used for genotyping the polymorphism. The mean serum homocysteine levels were significantly higher in cases than controls and associated with disease activity (p < .001). Furthermore, the homozygous MTHFR C677T variant genotype was associated with vitiligo development (adjusted OR: 3.52, 95% CI: 1.09-11.32, p = .02) and elevated homocysteine level (p < .001). There was no association between serum vitamin B12 levels and the MTHFR C677T genotype. The homozygous variant MTHFR C677T may be considered as a risk factor for both elevated homocysteine levels and the development of vitiligo in the Iranian population. Although these results are not conclusive, they could elucidate the contribution of genetic and immune-mediated inflammatory factors to the pathogenesis of vitiligo.

Genetic biomarkers related to hemarthrosis, inflammation, and cartilage structure in pediatric patients with hemophilic arthropathy

Background

The pathophysiology of hemophilic arthropathy is complex and not completely understood. In this study, we aimed to identify biomarkers that can affect the hemophilic arthropathy severity.

Methods

Fifty patients were analyzed for biomarker frequencies; in 37 patients, articular symptoms were evaluated based on the physical joint examination score, and in 18, it was based on magnetic resonance imaging. Eight polymorphisms, namely FV 1691G>A, FII 20210G>A, MTHFR 677C>T and 1298A>C, TNFα‐308G>A and ‐238G>A, ACAN VNTR, and IL1RN*2‐VNTR were identified.

Results

Patients with the MTHFR 677TT genotype showed a higher number of affected joints (1.83 ± 0.9 vs. 0.55 ± 0.7 for CC; p = .023), whereas those with the MTHFR 1298AC genotype exhibited higher effusion according to two radiologists (0.90 ± 0.31/1.20 ± 0.63 vs. 0.38 ± 0.52/0.50 ± 0.53 for AA genotype; p = .043/0.036, respectively). In addition, patients with the TNFα‐308GA genotype had more subchondral cysts (0.75 ± 0.95 vs. 0.07 ± 0.26 for GG genotype; p = .041).

Conclusions

The distribution of risk genotypes for MTHFR and TNFα‐308GA suggests their association with clinical parameters of hemophilic arthropathy. Cohort studies are essential to verify these associations.

The Role of Nitric Oxide, ADMA, and Homocysteine in The Etiopathogenesis of Preeclampsia-Review

Preeclampsia is a serious, pregnancy-specific, multi-organ disease process of compound aetiology. It affects 3–6% of expecting mothers worldwide and it persists as a leading cause of maternal and foetal morbidity and mortality. In fact, hallmark features of preeclampsia (PE) result from vessel involvement and demonstrate maternal endothelium as a target tissue. Growing evidence suggests that chronic placental hypoperfusion triggers the production and release of certain agents that are responsible for endothelial activation and injury. In this review, we will present the latest findings on the role of nitric oxide, asymmetric dimethylarginine (ADMA), and homocysteine in the etiopathogenesis of preeclampsia and their possible clinical implications.

Impact of β-thalassemia trait carrier state on inflammatory status in patients with newly diagnosed hypertension

BACKGROUND

B-thalassemia carrier state or thalassemia minor confers cardiovascular protection through favorable lipidemic and blood pressure profile. However, its impact on inflammatory status-a common denominator of the above conditions-has not been addressed.

METHODS

We investigated a wide range of inflammatory markers [white blood cell (WBC) count, homocysteine, C-reactive protein (CRP), serum amyloid A (SAA), fibrinogen, plasminogen, fibronectin, plasminogen activator inhibitor-1 (PAI-1), and uric acid] in a large cohort of 15 805 newly diagnosed hypertensive patients (8299 men, 7506 women); 626 of them (4.0%) had thalassemia minor.

RESULTS

The levels of WBC, homocysteine, CRP, SAA, fibrinogen, and PAI-1 were significantly lower in thalassemia minor patients, but not of plasminogen, fibronectin, and uric acid. In multivariate linear regression analyses, the lower values of WBC (<0.001), CRP (<0.001), homocysteine (<0.001), fibrinogen (<0.001), and PAI-1 (0.008), but not of SAA, were independently associated with thalassemia minor. The interaction between thalassemia minor and body mass index had a significant impact only on WBC and CRP (P for the interaction 0.010 and 0.005, respectively), whereas the interaction between thalassemia minor and sex had a significant impact only on fibrinogen (P for the interaction 0.007).

CONCLUSION

Thalassemia minor is followed by a favorable inflammatory profile that may contribute to the overall better cardiovascular health of the carriers.

Folic Acid and Vitamin B12 Administration in CKD, Why Not?

Patients affected by chronic kidney disease (CKD) or end-stage renal disease (ESRD) experience a huge cardiovascular risk and cardiovascular events represent the leading causes of death. Since traditional risk factors cannot fully explain such increased cardiovascular risk, interest in non-traditional risk factors, such as hyperhomocysteinemia and folic acid and vitamin B12 metabolism impairment, is growing. Although elevated homocysteine blood levels are often seen in patients with CKD and ESRD, whether hyperhomocysteinemia represents a reliable cardiovascular and mortality risk marker or a therapeutic target in this population is still unclear. In addition, folic acid and vitamin B12 could not only be mere cofactors in the homocysteine metabolism; they may have a direct action in determining tissue damage and cardiovascular risk. The purpose of this review was to highlight homocysteine, folic acid and vitamin B12 metabolism impairment in CKD and ESRD and to summarize available evidences on hyperhomocysteinemia, folic acid and vitamin B12 as cardiovascular risk markers, therapeutic target and risk factors for CKD progression.

Relationship between Malignant Brain Tumors and Values of Homocysteine, Folic Acid and Vitamin B12

Glioblastoma (GBM) is the most common primary malignant brain tumor in adults. Homocysteine (Hcy) has a detrimental influence on human neurons, considering that human GBM cells undergo cell death already at D,L-Hcy concentrations in culture medium of 50 μM. Th is data demonstrate that Hcy is a potent gliotoxic agent capable of inducing the death of human glial cells already at concentrations reached in brain during hyperhomocysteinemia. The one retrospective study found that the serum vitamin B12 level can be used to predict survival time in metastatic cancer patients including neurological cancer. Cancer risk increases with elevated vitamin B12 level, mostly within the first year of the follow-up period, suggesting that vitamin B12 level could be used as a cancer diagnostic marker. In addition, the relationship between elevated vitamin B12 level and poor cancer survival time has been reported. Previous investigation suggests that the folate supplementation could be used as an adjuvant in antiglioma therapy to limit the low DNA methylation level because this confers a poor prognosis in glioblastoma multiforme patients. Taking into account all presented data, it can be concluded that effect of homocystein, folic acid and vitamin B12 on formation, development and outcome of treatment in patients with carcinoma is very intriguing question, whose response requires additional both experimental and clinical research. There lack of data in the literature on the incidence of elevated levels of Hcy in the blood, as well as the disorders of folic acid and vitamin B12, at malignant tumors of the brain.

Serum homocysteine is associated with polycystic ovarian syndrome in Jordan

Polycystic ovarian syndrome (PCOS) is a prevalent endocrinopathy among women of a reproductive age. Although not included in the diagnostic criteria, insulin resistance (IR) is a major characteristic of PCOS and may contribute to its development. The exact cause of IR remains unknown but appears to be multifactorial. Changes in the levels of leptin, adiponectin, branched-chain amino acids (BCAAs) and/or homocysteine have been reported in women with PCOS. However, the relative contribution of the aforementioned metabolites to PCOS has not been tested in Jordan. In the present study, 154 women diagnosed with PCOS and 151 normally menstruating women matched by age and body mass index (BMI) were recruited. The levels of leptin, adiponectin, BCAAs, homocysteine and 5-methyltetrahydrofolate (5-MTHF) were measured in the serum of the recruited participants. It was revealed that homocysteine levels were significantly elevated in women with PCOS compared with normally menstruating women (P<0.0001), while 5-MTHF (P=0.024), leptin (P=0.027) and adiponectin (P=0.010) levels were significantly lower. In multivariate analysis, serum homocysteine had the strongest association with PCOS and significantly increased its risk [P<0.0001; odds ratio 1.217; 95% confidence interval (CI) 1.157-1.280]. With an area under the curve of 0.855 (95% CI 0.811-0.898) in receiver operating characteristic analysis, serum homocysteine was determined to be a good predictor for PCOS diagnosis based on Rotterdam guidelines. It was concluded that serum levels of homocysteine are elevated in women with PCOS in Jordan independent of age, BMI, or leptin, adiponectin and BCAAs levels.

Serum homocysteine, folate, and vitamin B12 levels in patients with vitiligo and their potential roles as disease activity biomarkers: A systematic review and meta-analysis

BACKGROUND

Hyperhomocysteinemia and folate and vitamin B₁₂ deficiencies have been reported in patients with vitiligo. Investigating the role of these conditions might shed light on the pathogenesis of vitiligo.

OBJECTIVE

To perform a systematic review and meta-analysis of studies assessing serum homocysteine, folate, and vitamin B₁₂ levels in vitiligo patients.

METHODS

Online databases were searched on May 15, 2018, to identify studies comparing serum homocysteine, folate, and vitamin B₁₂ levels between patients with vitiligo and controls. A random effects model was used.

RESULTS

Twenty-two studies involving a total of 1448 patients with vitiligo were included. Patients with vitiligo had significantly higher serum homocysteine levels (standardized mean difference [SMD] 0.550, 95% confidence interval [CI] 0.262-0.838; I² 87.3%) and lower vitamin B₁₂ levels (SMD -0.430, 95% CI -0.738 to -0.121; I² 85.3%) than controls. Serum folate levels were not significantly different between the 2 groups (SMD -0.240, 95% CI -0.592 to 0.111; I² 85.5%). A subgroup analysis revealed that these findings correlated with disease activity.

LIMITATIONS

The included studies were heterogeneous. Serum homocysteine levels could be influenced by various factors.

CONCLUSION

Patients with vitiligo have higher serum homocysteine levels and lower vitamin B₁₂ levels than individuals without vitiligo.

Changes in total homocysteine levels after acute stroke and recurrence of stroke

It is not known how total homocysteine (tHcy) levels change during the transition from acute stroke to post-stroke convalescence or whether tHcy changes occurring after the acute period are associated with recurrence of cerebro-cardiovascular events. Levels of tHcy were measured during acute ischemia and again after three months. Patients were followed for a median of 18 (range: 12–36) months. A total of 2800 patients who had at least two tHcy measurements were enrolled between February 2012 and June 2014; 2587 patients presented with ischemic stroke and 213 presented with cerebral hemorrhage. During the follow-up period, 220 (7.9%) patients experienced another ischemic event. After adjusting for additional cardiovascular risk factors, patients with the highest levels of tHcy (fourth quartile; >15.5 μmol/L) had a 1.76-fold increased risk of a recurrence (adjusted HR: 1.76, 95%CI: 1.11–3.08) as compared to patients with the lowest levels of tHcy (lowest quartile; ≤9.65 μmol/L). Additional analysis by subgroup indicated that this correlation was only significant for patients with large-artery atherosclerosis ischemia (adjusted HR: 2.00, 95%CI: 1.13–3.55). Elevated tHcy during the convalescent phase of acute stroke was independently associated with an increased risk of recurrent ischemic stroke, especially in those patients with large-vessel atherosclerosis ischemia.

Serum homocysteine, arsenic methylation, and arsenic-induced skin lesion incidence in Bangladesh: A one-carbon metabolism candidate gene study

BACKGROUND

Inorganic arsenic (As) is methylated via one carbon metabolism (OCM) to mono- and dimethylated arsenicals (MMA and DMA), facilitating urinary excretion. Hyperhomocysteinemia (HHcys), a marker of impaired OCM, is a risk factor for As-induced skin lesions, but the influences of single nucleotide polymorphisms (SNPs) in OCM genes on Hcys, As metabolism and skin lesion risk is unclear.

OBJECTIVES

To (i) explore genetic sources of Hcys and the causal role of HHcys in As-induced skin lesion development using OCM genetic proxies for HHcys and (ii) identify OCM SNPs associated with urinary As metabolite proportions and/or skin lesion incidence.

METHODS

We conducted a case-control study nested in the Health Effects of Arsenic Longitudinal Study (HEALS) in Bangladesh which 876 incident skin lesion cases were matched to controls on sex, age, and follow-up time. We measured serum Hcys, urinary As metabolites, and 26 SNPs in 13 OCM genes.

RESULTS

Serum Hcys and urinary %DMA were independently associated with increased and decreased odds of skin lesions, respectively. The T allele of MTHFR 677 C ➔ T (rs1801133) was associated with HHcys, higher %MMA, and lower %DMA, but not with skin lesions. Interactions between SNPs and water As on skin lesion risk were suggestive for three variants: the G allele of MTRR rs1801394 and T allele of FOLR1 rs1540087 were associated with lower odds of skin lesions with lower As (≤50 μg/L), and the T allele of TYMS rs1001761 was associated with higher odds of skin lesions with higher As.

CONCLUSIONS

While HHcys and decreased %DMA were associated with increased risk for skin lesions, and MTHFR 677 C ➔ T was a strong predictor of HHcys, MTHFR 677 C ➔ T was not associated with skin lesion risk. Future studies should explore (i) non-OCM and non-genetic determinants of Hcys and (ii) if genetic findings are replicated in other As-exposed populations, mechanisms by which OCM SNPs may influence the dose-dependent effects of As on skin lesion risk.

Homocysteine and Incident Atrial Fibrillation: The Atherosclerosis Risk in Communities Study and the Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Although many studies have investigated the association of blood homocysteine with major cardiovascular diseases such as coronary heart disease and stroke, research on its association with atrial fibrillation (AF) is scarce.

METHODS

We analysed data from Atherosclerosis Risk in Communities (ARIC) Study (n=492, age 45-64 years) and Multi-Ethnic Study of Atherosclerosis (MESA) (n=6,641, age 45-84 years).

RESULTS

During the 10,106 and 67,613 person-years of follow-up, we identified 85 and 351 AF events in ARIC and MESA, respectively. An age-, sex-, and race-adjusted model showed dose-response relations between plasma homocysteine concentrations and AF incidence in both ARIC and MESA. Further adjustments for other AF risk factors did not change the associations. In the fully adjusted model, a meta-analysis of both studies showed a significant association between homocysteine and AF [hazard ratio (95% confidence interval) per 1 unit increment in log₂(homocysteine), 1.27 (1.01-1.61)]. Individuals with higher levels of all three B vitamins (vitamin B6 and B12, and folate) had a lower risk of AF, but those associations were not statistically significant. In the full ARIC cohort [n=12,686 (2079 AF events)], there was no association between the C₆₇₇T methylenetetrahydrofolate reductase (MTHFR) mutation and AF.

CONCLUSIONS

In the prospective population-based ARIC and MESA cohorts, elevated homocysteine was modestly associated with an increased risk of incident AF, but the C6₇₇T MTHFR mutation was not associated with AF risk, suggesting that homocysteine may be a novel risk marker for AF rather than a causal risk factor.

The Protective Effects of Enalapril Maleate and Folic Acid Tablets against Contrast-Induced Nephropathy in Diabetic Rats

Background

Renal vasoconstriction, oxidative stress, endothelial dysfunction, and apoptosis are the major causes of contrast-induced nephropathy (CIN). The aim of this study was to evaluate the protective effects of enalapril maleate and folic acid tablets on CIN in diabetic rats.

Methods

Thirty-two Sprague-Dawley rats were divided into four groups: CIN (C), CIN + enalapril maleate (CE), CIN + folic acid (CF), and CIN + enalapril maleate and folic acid tablets (CEF). CE, CF, and CEF rats were treated orally with enalapril maleate, folic acid, or enalapril maleate and folic acid tablets, respectively, for 5 days. CIN was induced in all groups followed by analyzed biochemical parameters, oxidative stress markers, endothelial dysfunction parameters, renal histopathology, and TUNEL staining.

Results

Serum creatinine, blood urea nitrogen, and malondialdehyde levels were lower in the CEF group than in the C group. Homocysteine, superoxide dismutase, glutathione peroxidase, and nitric oxide levels were higher in the CEF group than in the C group. Histopathology scores and percentage of apoptotic kidney cells in the CEF group were significantly decreased compared with those in the C group.

Conclusions

These results suggest that enalapril maleate and folic acid tablets have a protective effect against CIN in diabetic rats.

Cardiovascular Risk Markers in Hemodialysis Patients

Cardiovascular events are the main cause of death in hemodialysis patients. Nevertheless, acute myocardial infarction may be misdiagnosed in uremic patients, because typical markers have a high rate of false positivity. A recent two-year prospective study showed that predialytic high serum concentrations of troponin T and CK-MB mass were associated with high mortality, cardiac mortality, myocardial infarction and unstable angina (MACEs). We studied 16 uremic patients (13 M; 3 W) on standard HD and 6 patients (4 M; 2 W) on on-line HDF, who had been taking folic acid for at least three months. Patients who suffered from acute or chronic cardiac ischemic disease were excluded. Anthropometric parameters, pre and post-dialytic pH, HCO3 and electrolytes did not differ between the two groups. Kt/V and URR % were lower in conventional HD vs on-line HDF (p<0.04; p<0.04). ORR % was strongly elevated in on-line HDF compared with HD (p<0.005). In conventional HD, ORR % was directly correlated with Kt/V and URR% (r = 0.49, p<0.04; r = 0.48, p<0.04, respectively). Even in on-line HDF ORR % was directly correlated with Kt/V and URR % (r = 0.79, p<0.04; r = 0.76, p<0.05, respectively). Troponin I and CK-MB mass were not significantly different in pre vs post-dialysis, both in standard HD and on-line HDF. Nevertheless, in standard HD postdialytic troponin I correlated with serum sodium concentration (r = 0.93, p < 0.000), potassium (r = 0.67, p < 0.004) and serum chlorine (r = 0.92, p < 0.92, p < 0.000). CK-MB mass showed a correlation with serum chlorine (r = 0.49, p < 0.05). Postdialytic CK-MB mass correlated with serum potassium in on-line HDF (r = 0.83, p < 0.03). Our data suggest that hemodialytic treatments, both standard HD and on-line HDF, do not modify serum troponin I and CK-MB mass. Consequently, we can use these parameters for the diagnostic approach in acute or chronic ischemic heart disease in hemodialysis patients.

A label-free fluorimetric detection of biothiols based on the oxidase-like activity of Ag+ ions

In this work, a label-free and sensitive fluorimetric method has been developed for the detections of biothiols including cysteine (Cys), homocysteine (Hcy), and glutathione (GSH), based on the specific biothiol-induced inhibition of the oxidase-like activity of silver ions (Ag⁺). It is well established that o-phenylenediamine (OPD) can be oxidized by Ag⁺ ions to generate fluorescent 2,3-diaminophenazine (OPDox). The introduction of biothiols would inhibit the oxidation of OPD by Ag⁺ due to the strong coordination between biothiols and Ag⁺. The changes of fluorescence intensities obtained in the Ag⁺-OPD system exhibited good linear correlations in the ranges of 0.50-30.0μM for Cys, 1.0-45.0μM for Hcy and 0.50-40.0μM for GSH. The detection limits (S/N=3) of Cys, Hcy and GSH were 110nM, 200nM and 150nM, respectively. Subsequently, the developed fluorimetric method was successfully applied for the detection of biothiols in human serum.

Predictive abilities of cardiovascular biomarkers to rapid decline of renal function in Chinese community-dwelling population: a 5-year prospective analysis

BACKGROUND

Predictive abilities of cardiovascular biomarkers to renal function decline are more significant in Chinese community-dwelling population without glomerular filtration rate (GFR) below 60 ml/min/1.73m², and long-term prospective study is an optimal choice to explore this problem. Aim of this analysis was to observe this problem during the follow-up of 5 years.

METHODS

In a large medical check-up program in Beijing, there were 948 participants with renal function evaluated at baseline and follow-up of 5 years. Physical examinations were performed by well-trained physicians. Blood samples were analyzed by qualified technicians in central laboratory.

RESULTS

Median rate of renal function decline was 1.46 (0.42-2.91) mL/min/1.73m²/year. Rapid decline of renal function had a prevalence of 23.5% (223 participants). Multivariate linear and Logistic regression analyses confirmed that age, sex, baseline GFR, homocysteine and N-terminal pro B-type natriuretic peptide (NT-proBNP) had independently predictive abilities to renal function decline rate and rapid decline of renal function (p < 0.05 for all). High-sensitivity cardiac troponin T (hs-cTnT), carotid femoral pulse wave velocity and central augmentation index had no statistically independent association with renal function decline rate and rapid decline of renal function (p > 0.05 for all).

CONCLUSIONS

Homocysteine and NT-proBNP rather than hs-cTnT had independently predictive abilities to rapid decline of renal function in Chinese community-dwelling population without GFR below 60 ml/min/1.73m². Baseline GFR was an independent factor predicting the rapid decline of renal function. Arterial stiffness and compliance had no independent effect on rapid decline of renal function. This analysis has a significant implication for public health, and changing the homocysteine and NT-proBNP levels might slow the rapid decline of renal function.

Neopterin as an Effect Modifier of the Cardiovascular Risk Predicted by Total Homocysteine: A Prospective 2-Cohort Study

BACKGROUND

Plasma total homocysteine (tHcy) is related to plasma neopterin, an indicator of interferon-γ-mediated immune activation, and both biomarkers positively predict cardiovascular risk. We examined whether the association between tHcy and subsequent risk of acute myocardial infarction (AMI) was modified by systemic concentrations of neopterin and C-reactive protein among patients with coronary heart disease.

METHODS AND RESULTS

By Cox modeling, we explored the association between tHcy and risk of AMI in 4164 patients with suspected stable angina pectoris. Subgroup analyses were performed according to median levels of neopterin and C-reactive protein. A replication study was performed among 3749 patients with AMI at baseline. Median follow-up was 7.3 and 8.3 years among patients with stable angina pectoris and AMI, respectively. tHcy and neopterin correlated in both cohorts (rs=0.34 and rs=0.30 among stable angina pectoris and AMI patients, respectively, both P<0.001). tHcy predicted AMI in both cohorts, independent of B-vitamin treatment. However, significant risk associations were confined to patients with plasma neopterin above the median (hazard ratios [95% confidence interval] per 1-SD increment of log-transformed tHcy 1.38 [1.26-1.50] and 1.18 [1.10-1.26] among stable angina pectoris and AMI patients, respectively) (Pint<0.005 in both cohorts). Further, adding information on the interaction between tHcy and neopterin improved model discrimination and reclassification. tHcy and C-reactive protein were weakly related, and no effect modification was found by C-reactive protein.

CONCLUSIONS

Among patients with coronary heart disease, tHcy predicted risk of AMI only in subjects with concomitantly elevated plasma neopterin. Our results motivate further research on the relationship between homocysteine metabolism, cellular immune activation, and atherothrombosis.

Role of free fatty acids in endothelial dysfunction

Plasma free fatty acids levels are increased in subjects with obesity and type 2 diabetes, playing detrimental roles in the pathogenesis of atherosclerosis and cardiovascular diseases. Increasing evidence showing that dysfunction of the vascular endothelium, the inner lining of the blood vessels, is the key player in the pathogenesis of atherosclerosis. In this review, we aimed to summarize the roles and the underlying mechanisms using the evidence collected from clinical and experimental studies about free fatty acid-mediated endothelial dysfunction. Because of the multifaceted roles of plasma free fatty acids in mediating endothelial dysfunction, elevated free fatty acid level is now considered as an important link in the onset of endothelial dysfunction due to metabolic syndromes such as diabetes and obesity. Free fatty acid-mediated endothelial dysfunction involves several mechanisms including impaired insulin signaling and nitric oxide production, oxidative stress, inflammation and the activation of the renin-angiotensin system and apoptosis in the endothelial cells. Therefore, targeting the signaling pathways involved in free fatty acid-induced endothelial dysfunction could serve as a preventive approach to protect against the occurrence of endothelial dysfunction and the subsequent complications such as atherosclerosis.

Inducible nitric oxide synthase: Good or bad?

Nitric oxide synthases (NOS) are a family of isoforms responsible for the synthesis of the potent dilator nitric oxide (NO). Expression of inducible NOS (iNOS) occurs in conditions of inflammation, and produces large amounts of NO. In pathological conditions iNOS is regarded as a harmful enzyme and is proposed to be a major contributor to diseases of the cardiovascular system such as atherosclerosis. In this review, we address the notion that iNOS is a detrimental enzyme in disease and discuss its potentially beneficial roles. Additionally, we describe other molecules associated with iNOS in diseases such as atherosclerosis, and current research on therapeutic inhibitors tested to reduced pathology associated with cardiovascular diseases (CVD).

H2S and homocysteine control a novel feedback regulation of cystathionine beta synthase and cystathionine gamma lyase in cardiomyocytes

Hydrogen sulfide (H₂S), a cardioprotective gas, is endogenously produced from homocysteine by cystathionine beta synthase (CBS) and cystathionine gamma lyase (CSE) enzymes. However, effect of H₂S or homocysteine on CBS and CSE expression, and cross-talk between CBS and CSE are unclear. We hypothesize that homocysteine and H₂S regulate CBS and CSE expressions in a dose dependent manner in cardiomyocytes, and CBS deficiency induces cardiac CSE expression. To test the hypothesis, we treated murine atrial HL1 cardiomyocytes with increasing doses of homocysteine or Na₂S/GYY4137, a H₂S donor, and measured the levels of CBS and CSE. We found that homocysteine upregulates CSE but downregulates CBS whereas Na₂S/GYY4137 downregulates CSE but upregulates CBS in a dose-dependent manner. Moreover, the Na₂S-treatment downregulates specificity protein-1 (SP1), an inducer for CSE, and upregulates miR-133a that targets SP1 and inhibits cardiomyocytes hypertrophy. Conversely, in the homocysteine-treated cardiomyocytes, CBS and miR-133a were downregulated and hypertrophy was induced. In vivo studies using CBS+/-, a model for hyperhomocysteinemia, and sibling CBS+/+ control mice revealed that deficiency of CBS upregulates cardiac CSE, plausibly by inducing SP1. In conclusion, we revealed a novel mechanism for H₂S-mediated regulation of homocysteine metabolism in cardiomyocytes, and a negative feedback regulation between CBS and CSE in the heart.

Elevated Plasma Homocysteine Level Increased the Risk of Early Renal Impairment in Acute Ischemic Stroke Patients

Renal insufficiency is associated with the prognosis of acute ischemic stroke (AIS) and homocysteine (Hcy) levels. This study investigated the association between plasma Hcy levels and renal insufficiency in patients with AIS. A total of 987 patients with AIS who had been treated at the First People's Hospital of Foshan between 2011 and 2014 were retrospectively studied. Based on their cystatin C (Cys C) levels, the patients were divided into the normal renal function group (Cys C ≤ 1.25 mg/L) or the renal impairment group (Cys C > 1.25 mg/L). Multivariate regression analysis was applied to reveal the association between hyperhomocysteinemia (HHcy) and renal impairment. The renal impairment group showed more advanced age of onset, higher percentage of prior stroke and hypertension, higher baseline National Institute of Health Stroke Scale score, lower high-density lipoprotein cholesterol levels, and higher Hcy levels compared with the normal renal function group. A multivariate analysis revealed a relationship between early renal impairment and Hcy levels: an increase of Hcy by 1 μmol/L was associated with an increase of 12-18% of the risk of renal impairment among patients with AIS and HHcy. Patients with AIS and HHcy had a 2.42-3.51 fold increase of the risk of renal impairment compared with patients with normal Hcy level (P < 0.001). In conclusion, patients with stroke and HHcy could be more prone to renal impairment.

Homocysteine, Alcoholism, and Its Potential Epigenetic Mechanism

Alcohol is the most socially accepted addictive drug. Alcohol consumption is associated with some health problems such as neurological, cognitive, behavioral deficits, cancer, heart, and liver disease. Mechanisms of alcohol-induced toxicity are presently not yet clear. One of the mechanisms underlying alcohol toxicity has to do with its interaction with amino acid homocysteine (Hcy), which has been linked with brain neurotoxicity. Elevated Hcy impairs with various physiological mechanisms in the body, especially metabolic pathways. Hcy metabolism is predominantly controlled by epigenetic regulation such as DNA methylation, histone modifications, and acetylation. An alteration in these processes leads to epigenetic modification. Therefore, in this review, we summarize the role of Hcy metabolism abnormalities in alcohol-induced toxicity with epigenetic adaptation and their influences on cerebrovascular pathology.

Effects of Ready-to-Eat-Cereals on Key Nutritional and Health Outcomes: A Systematic Review

BACKGROUND

In many countries breakfast cereals are an important component of breakfast. This systematic review assesses the contribution of consumption of ready-to eat cereal (RTEC) to the recommended nutrient intake. Furthermore, the effects of RTEC consumption on key health parameters are investigated as well as health promoting properties of RTEC.

METHOD

The Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE and CINAHL have been searched up till 16th of June 2015. Randomized controlled trials were excluded if RTEC were used during hypocaloric diets, if RTEC were eaten at other times than breakfast and if breakfasts included other products than RTEC, milk and fruit. Observational studies were excluded when "breakfast cereals" were not defined or their definition included cooked cereals. From cross-sectional studies only data concerning energy and nutrient intake as well as micronutrient status were used.

RESULTS

From 4727 identified citations 64 publications met the inclusion criteria of which 32 were cross-sectional studies, eight prospective studies and 24 randomized controlled trials. Consumption of RTEC is associated with a healthier dietary pattern, concerning intake of carbohydrates, dietary fiber, fat and micronutrients, however total sugar intake is higher. Persons consuming RTEC frequently (≥ 5 times/week) have a lower risk of inadequate micronutrient intake especially for vitamin A, calcium, folate, vitamin B 6, magnesium and zinc. Evidence from prospective studies suggests that whole grain RTEC may have beneficial effects on hypertension and type 2 diabetes. Consumption of RTEC with soluble fiber helps to reduce LDL cholesterol in hypercholesterolemic men and RTEC fortified with folate can reduce plasma homocysteine.

DISCUSSION

One of the review's strengths is its thorough ex/inclusion of studies. Limitations are that results of observational studies were based on self-reported data and that many studies were funded by food-industry.

CONCLUSION

Consumption of RTEC, especially of fiber-rich or whole grain RTEC, is implicated with several beneficial nutritional and health outcomes. The effect on body weight, intestinal health and cognitive function needs further evaluation. Of concern is the higher total sugar intake associated with frequent RTEC consumption.