Catalpol inhibits HHcy-induced EndMT in endothelial cells by modulating ROS/NF-κB signaling.

BACKGROUND: Hyperhomocysteinemia (HHcy) is an independent risk factor for atherosclerosis (AS). Endothelial mesenchymal transition (EndMT) refers to the process in which endothelial cells lose endothelial cell morphology and characteristic gene expression, and acquire phenotypic characteristics and gene expression related to mesenchymal cells. Numerous studies have confirmed that EndMT is involved in the formation of atherosclerosis. Catalpol is one of the active components of Rehmannia, which has antioxidant, anti-inflammatory, anti-tumor, neuroprotective and other biological activities. Studies have shown that catalpol can reduce atherosclerotic plaque induced by high sugar or fat. However, the effect of catalpol on HHCY-induced EndMT is unclear. METHODS AND RESULTS: In vitro HHcy-treated primary human umbilical vein endothelial cells (HUVECs) were used to construct a cell model, and the antioxidants N-acetylcysteine (NAC) and catalase alcohol were administered. In vivo C57BL/6N mice were given a diet fed with 4.4% high methionine chow to construct a HHcy mice model and were treated with catalpol. The results showed that hhcy could induce morphological transformation of endothelial cells into mesenchymal cells, increase intracellular ROS content, up-regulate α-SMA, N-cadherin, p-p65 protein expression, down-regulate VE-cadherin, CD31 protein expression, induce pathological changes of aortic root endothelium, and increase aortic endothelial ROS content. Catalpol reversed these hhcy induced outcomes. CONCLUSIONS: Catalpol inhibits HHcy-induced EndMT, and the underlying mechanism may be related to the ROS/NF-κB signaling pathway. Catalpol may be a potential drug for the treatment of HHcy-related AS.

N-homocysteinylation of DJ-1 promotes neurodegeneration in Parkinson's disease.

DJ-1, also known as Parkinson's disease protein 7 (Park7), is a multifunctional protein that regulates oxidative stress and mitochondrial function. Dysfunction of DJ-1 is implicated in the pathogenesis of Parkinson's disease (PD). Hyperhomocysteinemia is associated with an increased risk of PD. Here we show that homocysteine thiolactone (HTL), a reactive thioester of homocysteine (Hcy), covalently modifies DJ-1 on the lysine 182 (K182) residue in an age-dependent manner. The N-homocysteinylation (N-hcy) of DJ-1 abolishes its neuroprotective effect against oxidative stress and mitochondrial dysfunction, exacerbating cell toxicity. Blocking the N-hcy of DJ-1 restores its protective effect. These results indicate that the N-hcy of DJ-1 abolishes its neuroprotective effect and promotes the progression of PD. Inhibiting the N-hcy of DJ-1 may exert neuroprotective effect against PD.

Cerebral venous thrombosis associated with hyperhomocysteinemia and iron-deficiency anemia induced by autoimmune gastritis: A case report and literature review.

Cerebral venous thrombosis (CVT) is a rare disease, occurring in 0.5%-1% of all patients with strokes. Systemic and hereditary diseases and traumas are potential causes of CVT. We report a case of CVT and systemic thromboembolism complicated with hyperhomocysteinemia and iron-deficiency anemia caused by autoimmune gastritis. A 47-year-old female patient was admitted to the emergency department due to difficulty in movement, impaired consciousness, and urinary incontinence. Brain computed tomography (CT) and magnetic resonance imaging (MRI) showed bilateral thalamic edema associated with venous sinus thrombosis and embolic cerebral infarction in the deep white matter of the bilateral cerebral hemispheres. In addition, contrast enhanced whole-trunk CT scan showed deep femoral thrombosis and pulmonary artery embolism. She had no medical history of diseases or drug use that may cause thrombosis. Blood test results revealed iron-deficiency anemia and hyperhomocysteinemia, which were determined to be the cause of systemic thromboembolism. The patient tested positive for intrinsic factor antibodies. Moreover, the patient was diagnosed with autoimmune gastritis by gastrointestinal endoscopy. Therapies including anticoagulant and replacement with iron and vitamin B12 were administered. The patient was discharged from the hospital without neurological deficits. A favorable clinical course was achieved with anticoagulant administration and replacement therapy with iron and vitamin B12 for cerebral arteriovenous embolism that developed due to autoimmune gastritis.

Epigallocatechin-3-gallate Enhances Cognitive and Memory Performance and Protects Against Brain Injury in Methionine-induced Hyperhomocysteinemia Through Interdependent Molecular Pathways.

Brain injury and cognitive impairment are major health issues associated with neurodegenerative diseases in young and aged persons worldwide. Epigallocatechin-3-gallate (EGCG) was studied for its ability to protect against methionine (Met)-induced brain damage and cognitive dysfunction. Male mice were given Met-supplemented in drinking water to produce hyperhomocysteinemia (HHcy)-induced animals. EGCG was administered daily concurrently with Met by gavage. EGCG attenuated the rise in homocysteine levels in the plasma and the formation of amyloid-ß and tau protein in the brain. Cognitive and memory impairment in HHcy-induced mice were significantly improved by EGCG administration. These results were associated with improvement in glutamate and gamma-aminobutyric acid levels in the brain. EGCG maintained the levels of glutathione and the activity of antioxidant enzymes in the brain. As a result of the reduction of oxidative stress, EGCG protected against DNA damage in Met-treated mice. Moreover, maintaining the redox balance significantly ameliorated neuroinflammation evidenced by the normalization of IL-1ß, IL-6, tumor necrosis factor α, C-reactive protein, and IL-13 in the same animals. The decreases in both oxidative stress and inflammatory cytokines were significantly associated with upregulation of the antiapoptotic Bcl-2 protein and downregulation of the proapoptotic protein Bax, caspases 3 and 9, and p53 compared with Met-treated animals, indicating a diminution of neuronal apoptosis. These effects reflect and explain the improvement in histopathological alterations in the hippocampus of Met-treated mice. In conclusion, the beneficial effects of EGCG may be due to interconnecting pathways, including modulation of redox balance, amelioration of inflammation, and regulation of antiapoptotic proteins.

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 ß-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.

Effects of individualized administration of folic acid on prothrombotic state and vascular endothelial function with H-type hypertension: A double-blinded, randomized clinical cohort study.

BACKGROUND: Hypertension and hyperhomocysteinemia (HHcy) have long been associated with adverse cardiovascular and cerebrovascular health outcomes. This study evaluated the effect of individualized administration of folic acid (FA) on homocysteine (Hcy) levels, prothrombotic state, and blood pressure (BP) in patients with H-type hypertension (combination of HHcy and hypertension). METHODS: In this double-blinded, randomized clinical cohort study, 126 patients with H-type hypertension who were treated at our hospital were randomly divided into treatment and control groups (n = 55 each). The control group was treated with oral levamlodipine besylate tablets 2.5 mg and placebo, once a day (in the morning). The treatment group was first treated with oral levamlodipine besylate 2.5 mg and FA tablets 0.8 mg, once a day (in the morning), for 12 weeks. Then, in a second 12-week phase, the FA dose was adjusted using the methylene tetrahydrofolate reductase C677 polymorphism genotype. The levels of Hcy and coagulation factors, prothrombotic state parameters, BP, and adverse drug reactions were compared between the 2 groups. RESULTS: Pretreatment general patient characteristics, including Hcy levels, were similar between the 2 groups (P > .05). BP and prothrombotic status did not differ before and after the first phase of treatment (P > .05). However, Hcy and endothelin-1 (ET-1) levels decreased, while nitric oxide levels increased significantly in the intervention group (P < .05). In the second phase, after 3 months' treatment with an FA dose adjusted according to methylene tetrahydrofolate reductase C677T genotype, the Hcy and ET-1/NO levels were significantly decreased in the intervention group and were lower than those after the first treatment phase and lower than in the control group (P < .01). BP, D-dimer levels, and fibrinogen scores were significantly lower after the second treatment phase (P < .01). There was no significant difference in the incidence of adverse drug reactions between the 2 groups (P > .05). CONCLUSIONS: Individualized administration of FA tablets can effectively reduce BP, and Hcy and coagulation factor levels, and significantly improve prothrombotic status in patients with H-type hypertension.

The role of B vitamins in stroke prevention.

Elevated plasma levels of homocysteine (Hcy) are a recognized risk factor for stroke. This relationship represents one aspect of the debated `Hcy hypothesis'. Elevated Hcy may be an independent and treatable cause of atherosclerosis and thrombotic vascular diseases. Further observations indicate that proper dietary supplementation with B-vitamins decreases total plasma Hcy concentrations and may be an effective intervention for stroke prevention. Metabolic vitamin B12 deficiency is a nutritional determinant of total Hcy and stroke risk. Genetic factors may link B vitamins with stroke severity due to the impact on Hcy metabolism of polymorphism in the genes coding for methylenetetrahydrofolate reductase, methionine-synthase, methionine synthase reductase, and cystathionine ß-synthase. Several meta-analyses of large randomized controlled trials exist. However, they are not completely in agreement about B vitamins' role, particularly folic acid levels, vitamin B12, and B6, in lowering the homocysteine concentrations in people at high stroke risk. A very complex relationship exists between Hcy and B vitamins, and several factors appear to modify the preventive effects of B vitamins in stroke. This review highlights the regulating factors of the active role of B vitamins active in stroke prevention. Also, inputs for further large, well-designed studies, for specific, particularly sensitive subgroups are given.

The protective mechanism of folic acid on hyperhomocysteinemia-related arterial injury in spontaneously hypertensive rats: Folic acid against arterial inflammation.

BACKGROUND: Hypertension associated with hyperhomocysteinemia (HHcy) is correlated with a high risk of vascular diseases. Studies found that folic acid (FA) supplementation can reduce the risk of cardiovascular and cerebrovascular events. The aim of the present study was to explore the potential mechanisms of FA attenuating HHcy-related arterial injury in spontaneously hypertensive rats (SHRs). METHODS: 24 SHRs were randomized into the control group, the HHcy group, and the HHcy + FA group (8 per group). The SHRs in the HHcy group and the HHcy + FA group were given DL-Hcy intraperitoneally to mimic hypertension associated with HHcy. The SHRs in the HHcy + FA group were given FA by gavage to mimic an FA-fortified diet. The histopathology and immunohistochemistry of rat aorta and carotid artery were analyzed, and the relative expression levels of immune/inflammation and oxidative stress molecules in arterial tissue were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot. RESULTS: FA significantly reduced the expression levels of nuclear factor-κ-gene binding (NF-κB) p65/Rela and interleukin-6 (IL-6) in rat arterial tissues, as well as the levels of plasma HHcy and serum malondialdehyde (MDA) in hypertension associated with HHcy rats (p < 0.05). At the same time, FA significantly increased the serum superoxide dismutase (SOD) level in hypertension associated with HHcy rats, and even the SOD level of the HHcy + FA group was higher than that of the control group (p < 0.05). However, HHcy induced the opposite results of the above indicators in SHRs compared with the control group (p < 0.05). CONCLUSIONS: The arterial protection mechanisms of FA are related to reducing the concentration of HHcy to eliminate the tissue toxicity of HHcy, inhibiting NF-κBp65/Rela/IL-6 pathway molecules to regulate inflammatory response, and promoting the potential anti-oxidative stress pathway molecules to reduce oxidative stress level.

Hyperhomocysteinemia-related serum metabolome alterations not normalized by short-term folic acid treatment.

INTRODUCTION: Hyperhomocysteinemia (HHCys) is an independent risk factor for various diseases such as cardiovascular diseases, Alzheimer's, and cancers. Folate deficiency is one of the significant reasons for HHCys. However, it is not known whether folate deficiency with HHCys is associated with any serum metabolites. OBJECTIVES: Our objective was to identify the metabolic alterations in people having folate deficiency with HHCys and check whether a short-term folic acid therapy could reverse those metabolic changes. METHODS: The study enrolled 34 participants aged between 18 and 40 years having folate deficiency (< 4.6 ng/mL) with HHCys (> 15 µmol/L) and 21 normal healthy individuals. A short-term intervention of oral folic acid (5 mg/day) was done in the HHCys group for 30 days. Untargeted metabolomics analysis of serum was performed in all study subjects before and after the folic acid treatment. Different univariate methods and the multivariable-adjusted linear regression models were employed to determine an association between homocysteine level and metabolite profile. RESULTS: Metabolomics analysis data showed that many metabolites involved in the biochemical pathways of lipid metabolisms such as polyunsaturated fatty acids, glycerolipids, and phospholipids were downregulated in the HHCys group. Short-term oral folic acid therapy significantly reduced their serum homocysteine level. However, the metabolic pathway alterations observed in folate-deficient HHCys-condition were unaltered even after the folic acid treatment. CONCLUSIONS: Our study revealed that people who have a folic acid deficiency with HHCys have an altered metabolite profile related to lipid metabolism, which cannot be reversed by short-term folic acid therapy.

Physcion, a tetra-substituted 9,10-anthraquinone, prevents homocysteine-induced endothelial dysfunction by activating Ca2+- and Akt-eNOS-NO signaling pathways.

BACKGROUND: Homocysteine (Hcy) induced vascular endothelial dysfunction is known to be closely associated with oxidative stress and impaired NO system. 1,8-Dihydroxy-3-methoxy-6-methylanthracene-9,10-dione (physcion) has been known to has antioxidative and anti-inflammatory properties. PURPOSE: The purpose of the present study was to define the protective effect of physcion on Hcy-induced endothelial dysfunction and its mechanisms involved. STUDY DESIGN AND METHODS: Hyperhomocysteinemia (HHcy) rat model was induced by feeding 3% methionine. A rat thoracic aortic ring model was used to investigate the effects of physcion on Hcy-induced impairment of endothelium-dependent relaxation. Two doses, low (L, 30 mg/kg/day) and high (H, 50 mg/kg/day) of physcion were used in the present study. To construct Hcy-injured human umbilical vein endothelial cells (HUVECs) model, the cells treated with 3 mM Hcy. The effects of physcion on Hcy-induced HUVECs cytotoxicity and apoptosis were studied using MTT and flow cytometry. Confocal analysis was used to determine the levels of intracellular Ca2+. The levels of protein expression of the apoptosis-related markers Bcl-2, Bax, caspase-9/3, and Akt and endothelial nitric oxide synthase (eNOS) were evaluated by western blot. RESULTS: In the HHcy rat model, plasma levels of Hcy and malondialdehyde (MDA) were elevated (20.45 ± 2.42 vs. 4.67 ± 1.94 µM, 9.42 ± 0.48 vs. 3.47 ± 0.59 nM, p < 0.001 for both), whereas superoxide dismutase (SOD) and nitric oxide (NO) levels were decreased (77.11 ± 4.78 vs. 115.02 ± 5.63 U/ml, 44.51 ± 4.45 vs. 64.18 ± 5.34 µM, p < 0.001 and p < 0.01, respectively). However, treatment with physcion significantly reversed these changes (11.82 ± 2.02 vs. 20.45 ± 2.42 µM, 5.97 ± 0.72 vs. 9.42 ± 0.48 nM, 108.75 ± 5.65 vs. 77.11 ± 4.78 U/ml, 58.14 ± 6.02 vs. 44.51 ± 4.45 µM, p < 0.01 for all). Physcion also prevented Hcy-induced impairment of endothelium-dependent relaxation in HHcy rats (1.56 ± 0.06 vs. 15.44 ± 2.53 nM EC50 for ACh vasorelaxation, p < 0.05 vs. HHcy). In Hcy-injured HUVECs, physcion inhibited the impaired viability, apoptosis and reactive oxygen species. Hcy treatment significantly increased the protein phosphorylation levels of p38 (2.26 ± 0.20 vs. 1.00 ± 0.12, p <0.01), ERK (2.11 ± 0.21 vs. 1.00 ± 0.11, p <0.01) and JNK. Moreover, physcion reversed the Hcy-induced apoptosis related parameter changes such as decreased mitochondrial membrane potential (MMP) and Bcl-2/Bax protein ratio, and increased protein expression of caspase-9/3 in HUVECs. Furthermore, the downregulation of Ca2+, Akt, eNOS and NO caused by Hcy were recovered with physcion treatment in HUVECs. CONCLUSION: Physcion prevents Hcy-induced endothelial dysfunction by activating Ca2+- and Akt-eNOS-NO signaling pathways. This study provides the first evidence that physcion might be a candidate agent for the prevention of cardiovascular disease induced by Hcy.

Betaine Supplementation Moderately Increases Total Cholesterol Levels: A Systematic Review and Meta-Analysis.

Betaine is used to lower elevated plasma homocysteine levels, which are a risk factor for cardiovascular diseases (CVD). However, some studies have shown that betaine may have a negative effect on blood lipids. Betaine supplementation is becoming more and more common, but the relationship between betaine supplementation and blood lipoprotein levels are unclear. The purpose of the study described here was thus to perform a meta-analysis of randomized placebo-controlled trials on the effects of betaine supplementation at a daily dose of at least 4 g on blood lipids in adults. Six randomized controlled trials published between 2002 and 2018 were identified. All six studies used adult participants supplemented with at least 4 g/d of betaine for six to twenty-four weeks. A meta-analysis was carried out using a random-effects model, and the overall effect size was calculated for changes in plasma total cholesterol (TC), HDL cholesterol, LDL cholesterol, and triglycerides (TG). The pooled estimate of the effects of betaine supplementation compared to placebo on TC was 0.34 mmol/L (95% CI: 0.02, 0.65), p = 0.0352. No significant effect was observed for LDL, HDL, or TG. Supplementation with at least 4 g/d of betaine for a minimum of six weeks may moderately increase plasma TC, which might be important in the context of cardiovascular health.

Folic Acid Supplementation in Patients with Elevated Homocysteine Levels.

INTRODUCTION: Folic acid is the most important dietary determinant of homocysteine (Hcy). Hcy serves as a critical intermediate in methylation reactions. It is created from methionine and either converted back to methionine or transformed into cysteine. This process is aided through several enzymes and three vitamins, folic acid, B12, and B6. Daily supplementation with 0.5-5.0 mg of folic acid typically lowers plasma Hcy levels by approximately 25%. Hyperhomocysteinemia is a known risk factor for coronary artery disease. In this regard, elevated levels of Hcy have been found in a majority of patients with vascular disease. METHODS: A literature review of folic acid supplementation for various disease states including cardiovascular disease was conducted. This article is based on previously conducted studies and does not contain any studies with human participants or animals performed by any of the authors. RESULTS: In this review, we discuss the biochemistry of folic acid, Hcy biosynthesis, Hcy and hydrogen sulfide bioavailability, pathogenesis of hyperhomocysteinemia and its role as a risk factor for disease, and treatment studies with folic acid supplementation in disease states. CONCLUSION: Folic acid supplementation should be recommended to any patient who has an elevated Hcy level, and this level should be measured and treated at an early age, since folic acid is easily obtained and may likely reduce vascular disease and other deleterious pathologic processes in high-risk populations.

Hydrogen Sulfide Alleviates Anxiety, Motor, and Cognitive Dysfunctions in Rats with Maternal Hyperhomocysteinemia via Mitigation of Oxidative Stress.

Hydrogen sulfide (H2S) is endogenously produced from sulfur containing amino acids, including homocysteine and exerts neuroprotective effects. An increase of homocysteine during pregnancy impairs fetal growth and development of the offspring due to severe oxidative stress. We analyzed the effects of the H2S donor-sodium hydrosulfide (NaHS) administered to female rats with hyperhomocysteinemia (hHcy) on behavioral impairments and levels of oxidative stress of their offspring. Rats born from females fed with control or high methionine diet, with or without H2S donor injections were investigated. Rats with maternal hHcy exhibit increased levels of total locomotor activity and anxiety, decreased muscle endurance and motor coordination, abnormalities of fine motor control, as well as reduced spatial memory and learning. Oxidative stress in brain tissues measured by activity of glutathione peroxidases and the level of malondialdehyde was higher in rats with maternal hHcy. Concentrations of H2S and the activity and expression of the H2S generating enzyme-cystathionine-beta synthase-were lower compared to the control group. Administration of the H2S donor to females with hHcy during pregnancy prevented behavioral alterations and oxidative stress of their offspring. The acquisition of behavioral together with biochemical studies will add to our knowledge about homocysteine neurotoxicity and proposes H2S as a potential agent for therapy of hHcy associated disorders.

Evidence-based prevention of Alzheimer's disease: systematic review and meta-analysis of 243 observational prospective studies and 153 randomised controlled trials.

BACKGROUND: Evidence on preventing Alzheimer's disease (AD) is challenging to interpret due to varying study designs with heterogeneous endpoints and credibility. We completed a systematic review and meta-analysis of current evidence with prospective designs to propose evidence-based suggestions on AD prevention. METHODS: Electronic databases and relevant websites were searched from inception to 1 March 2019. Both observational prospective studies (OPSs) and randomised controlled trials (RCTs) were included. The multivariable-adjusted effect estimates were pooled by random-effects models, with credibility assessment according to its risk of bias, inconsistency and imprecision. Levels of evidence and classes of suggestions were summarised. RESULTS: A total of 44 676 reports were identified, and 243 OPSs and 153 RCTs were eligible for analysis after exclusion based on pre-decided criteria, from which 104 modifiable factors and 11 interventions were included in the meta-analyses. Twenty-one suggestions are proposed based on the consolidated evidence, with Class I suggestions targeting 19 factors: 10 with Level A strong evidence (education, cognitive activity, high body mass index in latelife, hyperhomocysteinaemia, depression, stress, diabetes, head trauma, hypertension in midlife and orthostatic hypotension) and 9 with Level B weaker evidence (obesity in midlife, weight loss in late life, physical exercise, smoking, sleep, cerebrovascular disease, frailty, atrial fibrillation and vitamin C). In contrast, two interventions are not recommended: oestrogen replacement therapy (Level A2) and acetylcholinesterase inhibitors (Level B). INTERPRETATION: Evidence-based suggestions are proposed, offering clinicians and stakeholders current guidance for the prevention of AD.

Intracranial High-Grade Stenosis and Hyperhomocysteinemia Presenting as Cortical Subarachnoid Hemorrhage Concomitant with Acute Ischemic Stroke in a Young Man.

BACKGROUND Cortical subarachnoid hemorrhage (cSAH) is a rare clinical presentation with different causes, but rarely happens along with acute ischemic stroke. Intracranial high-grade stenosis originated from brain has been regarded as an unusual cause of cSAH, especially in young adults. CASE REPORT A case of 33-year-old male presented with mild headache and spontaneous left-sided body weakness. Initial brain computed tomography (CT) showed cSAH in the right superior frontal sulcus. Further neuroimaging examinations including magnetic resonance imaging (MRI), digital subtraction angiography (DSA), transesophageal echocardiogram (TEE); in addition, lumbar puncture and blood tests were performed. Diffusion-weighted imaging (DWI) showed an acute infarction in the right frontal lobe and corona radiata of the territory of middle cerebral artery (MCA). The MR angiography (MRA) displayed no flow signal in the right middle cerebral artery M1-segment, while the DSA displayed bloodstream slowness in the right MCA M1-segment which suggested high-grade stenosis of the right MCA. The abnormal laboratory data suggested hyperhomocysteinemia, and excluded causes of thrombosis, infection, or cancer. The mechanism of cSAH may come about in severe atherosclerotic stenosis of MCAs by the broken of expanded tenuous compensatory pial vessels. The patient had good recovered at follow-up. CONCLUSIONS This case demonstrates cSAH with acute ischemic stroke, which is an uncommon complication, in a young adult stroke patient; a high-grade atherosclerotic stenosis of the MCA was identified as the etiology.

Cysteine is a better predictor of coronary artery disease than conventional homocysteine in high-risk subjects under preventive medication.

BACKGROUND AND AIMS: In Portugal, The Azores Archipelago has the highest standardized mortality rate for CAD. Therefore, the aim of this study was to evaluate conventional risk factors, as well as plasma and erythrocyte aminothiol concentration in high-risk Azorean patients undergoing elective coronary angiography and to investigate whether any aminothiol was associated with CAD risk and severity. METHODS AND RESULTS: 174 subjects with symptomatic CAD (age 56±9y; 68% men) submitted to coronary angiography were split into 2 groups: one formed by CAD patients (≥50% stenosis in at least one major coronary vessel) and the other by non-CAD patients (<50% stenosis). Both groups were age-, sex- and BMI-matched. Plasma and erythrocyte aminothiol profiles were evaluated by RP-HPLC/FLD. CAD patients significantly exhibited both higher concentrations of plasma Cys and hypercysteinemia (Cys ≥ 300 µM) prevalence than those in the non-CAD group (261 ± 58 µM vs. 243 ± 56 µM; 22% vs. 10%, respectively). No differences were observed between groups regarding plasma Hcy levels or hyperhomocysteinemia prevalence. After adjustment for several confounders (including Hcy), subjects in the highest quartile of plasma Cys had a 3.31 (95% CI, 1.32-8.30, p = 0.011) fold risk for CAD, compared with those in the lowest quartiles. Furthermore, plasma Cys levels (but not Hcy) tended to increase with the number of stenotic vessels (1VD: 253 ± 64 µM; 2VD: 262 ± 52 µM; 3VD: 279 ± 57 µM, p = 0.129). CONCLUSION: Hypercysteinemia revealed to be a better predictor of CAD than hyperhomocysteinemia. Moreover, plasma Cys showed to be a useful biomarker for CAD both in primary and secondary preventions, seeming to resist better than Hcy to oral medication therapy.

Low doses of folic acid can reduce hyperhomocysteinemia-induced glomerular injury in spontaneously hypertensive rats.

Hypertension associated with hyperhomocysteinemia (HHcy) is associated with a high risk of vascular diseases. However, the mechanisms of HHcy-associated hypertensive renal damage and the efficacy of folic acid (FA) as a treatment have not been fully elucidated. The aim of the present study was to evaluate whether lowering the plasma homocysteine (Hcy) level using different doses of FA can reduce HHcy-associated glomerular injury in spontaneously hypertensive rats (SHRs) and to clarify the potential mechanisms of such effects. SHRs were randomized into a control group, HHcy group, HHcy + low-dose FA (LFA) group, and HHcy + high-dose FA (HFA) group. Compared with the control group, the HHcy group had reduced serum superoxide dismutase and GFR levels and elevated serum malondialdehyde and urinary albumin creatinine ratio levels. Increased extracellular matrix of the glomerulus and an increased glomerular sclerosis index, podocyte foot process effacement and fusion, as well as increased podocyte apoptosis, were observed in the HHcy group compared with the control group; these effects were associated with increased expression of NOX2 and NOX4 and decreased nephrin expression in renal tissue from SHRs with HHcy. HHcy-induced changes were counteracted by LFA and HFA treatment. Apart from lower levels of NOX2 in the HHcy + HFA group, there were no significant differences in other indicators between the HHcy + LFA and HHcy + HFA groups. These results suggest that even at a low dose, FA can reduce plasma Hcy and attenuate HHcy-induced glomerular injury by inhibiting oxidative stress and apoptosis.

Cladribine Treatment Improved Homocysteine Metabolism and Increased Total Serum Antioxidant Activity in Secondary Progressive Multiple Sclerosis Patients.

Hyperhomocysteinemia plays a crucial role in the pathogenesis of many diseases of the central nervous system (CNS). The nervous system is particularly sensitive to high homocysteine (Hcy) level mainly due to its prooxidative and cytotoxic effects. Cladribine, a drug recently registered for the treatment of multiple sclerosis (MS), possesses additionally neuroprotective effects which are independent of its peripheral immunosuppressant action. Accumulating evidence suggests that oxidative stress and homocysteine thiolactone-mediated protein homocysteinylation play a causal role in MS. Both of these processes may be attenuated by paraoxonase 1 (PON1). Therefore, in the present study, we aimed to examine whether the beneficial effects of the drug in MS patients with a secondary progressive (SP) clinical course, treated with cladribine subcutaneously (s.c.), may be related to its ability to modify serum PON1 activity, Hcy concentration, and protein homocysteinylation, as well as to correct total antioxidant status. A total of 118 subjects were enrolled into the study: (1) patients with a SP type of MS, SP-MS (n = 40); (2) patients with a relapsing-remitting (RR) type of MS, RR-MS (n = 30); and (3) healthy people (n = 48). Patients with SP-MS were treated with cladribine. The drug was given in SP-SM patients s.c. six times every 6 weeks up to a total mean cumulative dose of 1.8 mg/kg. PON1 activity was assessed spectrophotometrically. The level of Hcy, homocysteine thiolactone (HTL) attached to plasma proteins (N-Hcy-protein), and antibodies against homocysteinylated proteins was assessed with an enzyme immunoassay. The total antioxidant activity of the serum was assessed with the ferric-reducing activity of plasma (FRAP) method. Basically, there was no difference in PON1 activity between untreated SP-MS, RR-MS, and control subjects. Serum Hcy was significantly higher in RR-MS patients (p < 0.001) and in SP-MS patients (p < 0.01) compared to the control group. The N-Hcy protein level was higher in RR-MS patients (p < 0.05) in comparison to the control group. Moreover, the elevated level of antibodies against homocysteinylated proteins was observed in the serum of patients with SP-MS. The total antioxidant capacity of serum was lower in MS patients vs. the control group (p < 0.001). After cladribine treatment, the activity of PON1 did not change in SP-MS patients, whereas cladribine treatment decreased the level of total Hcy (p < 0.05). Treatment with cladribine increased the total serum antioxidant activity in SP-MS patients (p < 0.01). The Expanded Disability Status Scale (EDSS) score did not change in SP-MS patients. Cladribine treatment in the SP-MS group attenuates hyperhomocysteinemia-induced protein homocysteinylation (n.s.). It also stabilises the neurological condition of SP-MS patients. The stabilisation of a neurological condition observed in SP-MS patients after cladribine treatment may be partially related to its ability to reduce elevated Hcy level and to improve serum antioxidant potential.

Hyperhomocysteinemia Causes Severe Intraoperative Thrombotic Tendency in Superficial Temporal Artery-middle Cerebral Artery Bypass.

CASE: Two years ago, annual magnetic resonance imaging for unruptured right internal carotid artery aneurysm of a 47-year-old woman detected a cerebral infarct in her right occipital lobe which was unknown etiology and antiplatelet therapy was initiated. She presented with sensory disorder of her left fingers 4 months ago. Infarction in right parieto-occipital cortex and severe stenosis of right middle cerebral artery was revealed. Her laboratory test was normal except remarkably high homocysteine value. Regardless of dual anti-platelet therapy, she suffered from repeated minor stroke and the stenosis was progressing. Therefore, right superficial temporal artery - middle cerebral artery bypass was undertaken. Aspirin and clopidogrel were withdrawn 1 week before the surgery. Two branches were anastomosed with 2 separate frontal M4 branches. Although patency was confirmed immediately after the anastomosis, thrombus formation was revealed after 10 minutes. We needed to perform removal of the thrombus and re-anastomosis twice. Intraoperative administration of aspirin and ozagrel alleviated thrombotic tendency. After surgery, antiplatelet therapy and supplementation with folate and vitamin B were performed. Her postoperative course was uneventful and patency of both anastomoses was confirmed. DISCUSSION: Controversy still exists regarding preoperative antiplatelet therapy before superficial temporal artery-middle cerebral artery bypass, and folates and B6-12 vitamins supplementation for hyperhomocysteinemia. Considering intraoperative thrombo tendency in our case, it is recommended to evaluate the homocysteine level before bypass surgery for intracranial stenosis especially for young patients or patients with unknown etiology. Before bypass surgery of the patient with hyperhomocysteinemia, continuation of perioperative antiplatelet drugs and supplementation with folates and B6-12 vitamins are mandatory.

Memantine Protects From Exacerbation of Ischemic Stroke and Blood Brain Barrier Disruption in Mild But Not Severe Hyperhomocysteinemia.

Background Hyperhomocysteinemia is a risk factor for ischemic stroke; however, a targeted treatment strategy is lacking partly because of limited understanding of the causal role of homocysteine in cerebrovascular pathogenesis. Methods and Results In a genetic model of cystathionine beta synthase (CBS) deficiency, we tested the hypothesis that elevation in plasma total homocysteine exacerbates cerebrovascular injury and that memantine, a N-methyl-D-aspartate receptor antagonist, is protective. Mild or severe elevation in plasma total homocysteine was observed in Cbs+/- (6.1±0.3 µmol/L) or Cbs-/- (309±18 µmol/L) mice versus Cbs+/+ (3.1±0.6 µmol/L) mice. Surprisingly, Cbs-/- and Cbs+/- mice exhibited similar increases in cerebral infarct size following middle cerebral artery ischemia/reperfusion injury, despite the much higher total homocysteine levels in Cbs-/- mice. Likewise, disruption of the blood brain barrier was observed in both Cbs+/- and Cbs-/- mice. Administration of the N-methyl-D-aspartate receptor antagonist memantine protected Cbs+/- but not Cbs-/- mice from cerebral infarction and blood brain barrier disruption. Our data suggest that the differential effect of memantine in Cbs+/- versus Cbs-/- mice may be related to changes in expression of N-methyl-D-aspartate receptor subunits. Cbs-/-, but not Cbs+/- mice had increased expression of NR2B subunit, which is known to be relatively insensitive to homocysteine. Conclusions These data provide experimental evidence that even a mild increase in plasma total homocysteine can exacerbate cerebrovascular injury and suggest that N-methyl-D-aspartate receptor antagonism may represent a strategy to prevent reperfusion injury after acute ischemic stroke in patients with mild hyperhomocysteinemia.