Homocysteine - from disease biomarker to disease prevention

Dyes-encapsulated metal-organic cage as fluorescence sensor array for the auxiliary differential diagnosis of MCD and FSGS in early renal disorders

Both minimal change disease (MCD) and focal segmental glomerular sclerosis (FSGS) are the pathological types of primary nephrotic syndrome (PNS) and cannot be readily distinguished owing to their highly similar clinical presentations. Currently, methods for clinical MCD and FSGS diagnosis still rely on invasive renal biopsy which impede rapid and accurate diagnosis for timely treatment management. In this study, a novel diagnostic strategy by introducing the dyes with spironolactone structure into the metal-organic cage to construct three dye@MOCs composites has been developed and employed as fluorescence sensor array for assisting in the auxiliary differential diagnosis of MCD and FSGS based on the distinguishable biothiols in urine. Through the statistical analysis technique for the interpretation of response patterns, the weak fluorescent of dye@MOCs sensor array exhibited unique patterns of fluorescence enhancement when biothiols appeared, forming the unique "off-on" sensor array. Additionally, dye@MOCs sensor array exhibited excellent selectivity and good stability, indicating their potentially actual applications. Outstandingly, as an important example, it was demonstrated for the first time that dye@MOCs sensor array can be applied to the auxiliary differential diagnosis of MCD and FSGS patients based on the differentiable biothiols level in urine using non-invasively methods, potentially avoiding invasive renal biopsy diagnosis and overcoming the limitations of conventional urine examinations, illustrating its potential applications in the auxiliary differential diagnosis and research of related diseases in the forthcoming era. And moreover, this opens new avenues for reliable disease auxiliary diagnosis and differentiation, setting a new benchmark for accuracy and reliability in medical assessments.

Hyperhomocysteinemia is linked to MASLD

BACKGROUND AND AIMS

Homocysteine (Hcy) levels are elevated in different conditions, including cardiovascular diseases (CVD), diabetes, and metabolic-associated steatotic liver disease (MASLD). In this observational retrospective study, we analyzed Hcy levels in a population of 901 outpatients, considering its putative etiological role in MASLD.

METHODS

A total of 901 outpatients underwent physical and biochemical evaluations. Abdominal and carotid ultrasound were performed to assess liver steatosis, carotid intima-media thickness (IMT) and presence of atherosclerotic plaque.

RESULTS

Hyperhomocysteinemia (HHcy) was identified in 140 subjects (16 %). Patients with HHcy showed glucose metabolism impairment (p < 0.001), altered lipid profile (p < 0.001), low Vitamin D levels (p < 0.0001), increased cardiovascular risk (p < 0.001). We then investigated the relationship between Hcy and MASLD (OR=3.6, p < 0.0001), finding that the relationship remained significant also when accounting for confounding variables (age, sex) (OR=3.2, p < 0.0001). Hcy values were significantly higher (p < 0.0001) in patients with MASLD (n = 78, 29.4 ± 10.1μmol/l) compared to those without MASLD (20.4 ± 4.8 1μmol/l). Furthermore, in MASLD patients we found a direct correlation between Hcy level and waist circumference (r = 0.3, p < 0.001) and an inverse correlation with both HDL-c (r=-0.4, p < 0.001) and Vitamin D levels (r=-0.24, p < 0.05).

CONCLUSIONS

Our data suggest an intriguing scenario whereby HHcy is present in patients with MASLD and is associated to lower vitamin D and altered glucose and lipid profile. Thus, considering Hcy levels may help clinicians with the management of patients with increased MASLD risk.

Anesthetics in pathological cerebrovascular conditions

The increasing prevalence of pathological cerebrovascular conditions, including stroke, hypertensive encephalopathy, and chronic disorders, underscores the importance of anesthetic considerations for affected patients. Preserving cerebral oxygenation and blood flow during anesthesia is paramount to prevent neurological deterioration. Furthermore, protecting vulnerable neurons from damage is crucial for optimal outcomes. Recent research suggests that anesthetic agents may provide a potentially therapeutic approach for managing pathological cerebrovascular conditions. Anesthetics target neural mechanisms underlying cerebrovascular dysfunction, thereby modulating neuroinflammation, protecting neurons against ischemic injury, and improving cerebral hemodynamics. However, optimal strategies regarding mechanisms, dosage, and indications remain uncertain. This review aims to clarify the physiological effects, mechanisms of action, and reported neuroprotective benefits of anesthetics in patients with various pathological cerebrovascular conditions. Investigating anesthetic effects in cerebrovascular disease holds promise for developing novel therapeutic strategies.

Hyperhomocysteinemia: Underlying Links to Stroke and Hydrocephalus, with a Focus on Polyphenol-Based Therapeutic Approaches

Hyperhomocysteinemia (HHcy), characterized by elevated homocysteine (HCys) levels, is associated with increased risks of neurovascular diseases such as stroke or hydrocephalus. HHcy promotes oxidative stress, neuroinflammation, and endothelial dysfunction, disrupting the blood-brain barrier and accelerating neurodegeneration. These processes highlight HCys as both a biomarker and a potential therapeutic target in vascular-related neurological disorders. Current research suggests that polyphenols, known for their antioxidant and anti-inflammatory properties, may reduce HCys levels and offer neuroprotection. Polyphenols have demonstrated effectiveness in modulating oxidative stress and inflammatory pathways triggered by HHcy. These compounds may also upregulate enzymatic functions involved in HCys metabolism, thus reducing neurotoxicity. Furthermore, polyphenol-rich diets, like the Mediterranean diet, have been linked to lower HCys levels and a reduced incidence of neurovascular disorders. This review provides an overview of HHcy's role in neurovascular pathologies and examines the therapeutic potential of polyphenols in managing HCys levels and preventing HCys-induced neurovascular damage.

Effect of plasma homocysteine on cardiometabolic multimorbidity among Chinese adults: a population-based and real-world evidence study

Aims

To explore the effect of plasma homocysteine (Hcy) on cardiometabolic multimorbidity (CMM) among Chinses adults.

Methods

This study combined a community-based cross-sectional study with a 1:1 matched case-control study using propensity score method among adults aged over 30 years in six districts randomly selected from Hunan Province, China. We recruited 5,258 people, of whom 4,012 met the study criteria were enrolled. CMM was defined as the coexistence of two or more cardiometabolic diseases, including diabetes, hypertension, coronary heart disease and stroke. The plasma Hcy and other laboratory data was measured by chemical automatic detector. Lifestyles and personal characteristics were collected by a questionnaire. Multivariate models were used to explore the associations. We calculated the attributable risk proportion (ARP) for the association of Hcy with CMM. The dose-response relationship was evaluated using restricted cubic splines method.

Results

Of the 4,012 adults, 436 had CMM, with a population prevalence of 10.9%. In the propensity-score-matched case-control study, 828 (414 cases and 414 controls) were included, and those with high plasma Hcy level (>16.2 μmol/L) had a higher risk of CMM than those with lowest level (<10.4 μmol/L) (adjusted OR = 2.83, 95% CI: 1.84-4.36, p < 0.001), with a multivariate ARP of high level of exposure was 64.66% (95% CI: 46.24-77.06%). The largest effect combination of CMM was the coexisting of diabetes, hypertension and coronary heart disease (adjusted OR = 2.26, 95%CI: 1.43-3.57, p < 0.001). An inverse association and dose-response relationship were observed between CMM and plasma Hcy levels. Notably, we recognized a significant mediation effect by C-reactive protein, total cholesterol, triglyceride and waist circumference, and they mediated approximately 8 ~ 23% of the effect of Hcy on risk of CMM.

Conclusion

Our findings add new evidence to this field that of high level of plasma Hcy was consistently associated with higher risk of CMM among Chinses adults, with the largest effect combination of being coexisting diabetes, hypertension and coronary heart disease. These findings have implications for cardiologists that CMM can be attributable to high level of plasma Hcy, and for decision makers that Hcy has become a public threat that persistently affects cardiovascular health in humans.

Association of maternal folic acid supplementation and offspring MTRR gene polymorphism with congenital heart disease: a hospital-based case-control study in Han population

BACKGROUND

Although many studies shown that the risk of congenital heart disease (CHD) was closely related to genetic and environmental factors, the exact mechanism was still unclear. This study was to assess the association of maternal folic acid supplementation (FAS), the 5-methyltetrahydrofolate-homocysteine methyltransferase reductase (MTRR) gene polymorphisms in offspring and their interaction effects with the risk of CHD and its subtypes.

METHODS

A case-control study was conducted on 595 children with CHD and 605 healthy child controls. The multivariate logistic regression model was used to assess the association of maternal FAS, offspring MTRR gene polymorphisms and their interaction effects with CHD and its subtypes.

RESULTS

This study shown that maternal FAS was significantly associated with a reduced risk of CHD (OR = 0.55, 95%CI: 0.36-0.83) and its subtypes including ASD (OR = 0.25, 95%CI: 0.14-0.45), VSD (OR = 0.42, 95%CI: 0.27-0.64), and CTD (OR = 0.23, 95%CI: 0.09-0.59) in offspring. Offspring MTRR gene polymorphisms at rs162048 (GG vs. AA: OR = 2.05, 95%CI: 1.35-3.13), rs1802059 (AA vs. GG: OR = 5.13, 95%CI: 2.15-12.23; GA vs. GG: OR = 1.81, 95%CI: 1.35-2.43), rs10380 (TT vs. CC: OR = 2.27, 95%CI: 1.20-4.31) and rs1801394 (GG vs. AA: OR = 1.58, 95%CI: 1.02-2.42) were significantly associated with the risk of CHD, and similar results were also found for three subtypes of CHD. Additionally, a statistically significant interaction effect between maternal FAS and offspring MTRR gene polymorphism at rs1802059 was observed (OR = 0.38, 95%CI: 0.15-0.94). Among children who had a variant genotype at rs1802059, the risk of CHD was significantly decreased when their mother used folate for this pregnancy compared with mothers not using folate.

CONCLUSIONS

In those of Chinese descent, maternal FAS and offspring MTRR gene polymorphisms are significantly associated with the risk of CHD and its three subtypes. Furthermore, maternal FAS may help to offset some of risks of CHD due to offspring MTRR genetic variants. However, more studies with prospective designs and larger samples are needed to confirm our findings.

TRIAL REGISTRATION

Registration number: ChiCTR1800016635; Registration time: 14/06/2018.

Homocysteine, neurodegenerative biomarkers, and APOE ε4 in neurodegenerative diseases

INTRODUCTION

Elevated plasma homocysteine (Hcy) is associated with an increased risk of developing neurodegenerative diseases; however, its relationship with the apolipoprotein E (APOE) ε4 allele has not been well characterized.

METHODS

Participants clinically diagnosed with Alzheimer's disease or mild cognitive impairment (AD/MCI), frontotemporal dementia, Parkinson's disease, or cerebrovascular disease were stratified by the presence of the APOE ε4 allele. Volumetric magnetic resonance imaging, plasma amyloid/tau/neurodegeneration biomarkers, and cognitive performance were quantified.

RESULTS

Across all diagnostic groups, Hcy was associated with lower brain parenchymal fraction and greater neurofilament light chain in APOE ε4 non-carriers only. In AD/MCI, Hcy was associated with phosphorylated tau 217 in APOE ε4 non-carriers, but not in carriers. Exploratory analyses revealed interactions between Hcy and APOE ε4 on memory and visuospatial function.

DISCUSSION

Hcy may contribute to neurodegeneration depending on the presence of the APOE ε4 allele and specific disease processes. Trials on vitamin B12 supplementation may consider stratifying by APOE genotype. Highlights Homocysteine (Hcy) was associated with neurodegenerative biomarkers across disease groups. Relationships with Hcy were predominantly found in apolipoprotein E (APOE) ε4 non-carriers. In Alzheimer's disease, associations between Hcy and phosphorylated tau 217 were found in APOE ε4 non-carriers only. Significant interactions existed between Hcy and APOE ε4 status on cognition.

Association between serum folate levels and migraine or severe headaches: A nationwide cross-sectional study

Migraine and severe headaches are common neurological disorders with significant societal impact. Previous research indicates a potential link between serum folate levels and migraine occurrence, yet there is a lack of sufficient relevant studies and more are required. This study aimed to determine the association between a severe headache or migraine and serum folate levels in large populations. Using data from the National Health and Nutrition Examination Survey, we conducted a cross-sectional study. Using multivariable logistic regression models, we investigated the association between serum folate and severe headache or migraine. In a subsequent subgroup analysis, several confounding factors were also explored to investigate the association between migraine and serum folate. A total of 13,351 individuals participated in the study, with 2742 reporting severe headache or migraine in the previous 3 months. Serum folate was negatively associated with severe headache or migraine (odds ratio [OR] = 0.5, 95% confidence interval [CI] = 0.28-0.89, P = .018). The stratified analysis revealed this association persisted among female (OR = 0.38, 95% CI = 0.18-0.82, P < .001), individuals aged 20 to 50 years (OR = 0.53, 95% CI = 0.28-0.99, P < .001), and non-Hispanic White participants (OR = 0.38, 95% CI = 0.17-0.87, P < .001). We found that greater levels of serum folate were significantly related to a decreased likelihood of migraine onset, especially among women, young and middle-aged populations, and non-Hispanic White participants. Further research is required to validate and expand upon our results.

The Influence of Atorvastatin Treatment on Homocysteine Metabolism and Oxidative Stress in an Experimental Model of Diabetic Rats

OBJECTIVE

In our experimental study, we evaluated the influence of treatment with atorvastatin on the antioxidant activity of intracellular and extracellular systems factors, homocysteine levels (Hcy), and lipid profiles in obese and diabetic rats.

METHOD

Twenty-one male Wistar rats, aged 6 months, 450-550 g, were allocated into three groups. From the beginning of the study, the first group (G-I, control) received only standard food, while the second and third groups (G II-obese, G III-diabetic) were administered a high-fat diet (HFD) with 2% cholesterol. After 2 weeks of accommodation, the specimens in G-III were injected intraperitoneal (i.p.) streptozotocin (35 mg of body weight, pH 4.5), intervention followed by the onset of type 2 diabetes mellitus. Following confirmation of diabetes onset, the specimens in G III were administered concomitantly with the HFD a daily gavage of atorvastatin 20 mg of body weight/day for 20 days. We measured, at the beginning and the end of the study, the Hcy levels, lipid profile, vitamin B12, B6, folic acid, and various parameters of oxidative stress (OS)-total antioxidant status (TAS), glutathione peroxidase (GPX) and superoxide dismutase (SOD).

RESULTS

After treatment with atorvastatin, the lipid profile in G III significantly improved compared to the other two groups, but enzymatic markers of oxidative stress did not closely parallel this trend. However, after the treatment of statin, we observed an important reduction in Hcy values.

CONCLUSION

Our results demonstrate that treatment with atorvastatin can be used not only for its lipid-lowering properties and antioxidant effects but also to reduce Hcy concentration in this experimental model of diabetic rats. Moreover, atorvastatin therapy improves lipid profiles, reduces inflammation, suppresses oxidation, and decreases Hcy levels, potentially preventing major adverse cardiovascular events.

Vitamin B12 protects necrosis of acinar cells in pancreatic tissues with acute pancreatitis

Pharmacological agents regarding the most optimal treatments of acute pancreatitis remain. One-carbon metabolism nutrients as therapeutic agents in many diseases might be involved in acute pancreatitis. The roles are acquired exploration in acute pancreatitis. We utilized Mendelian randomization to assess the causal impact of folate, homocysteine, and vitamin B12 (VB12) on acute pancreatitis. Wild-type and corresponding genetically modified mouse models were used to verify the genetic correlating findings. A negative association between genetically predicted serum VB12 levels and risks of acute pancreatitis was identified in human population. The transcobalamin receptor (TCblR)/CD320 gene ablation that decreased cellular VB12 uptake and ATP production in pancreatic tissues promoted necrosis, resulting in much severe pathological changes of induced acute pancreatitis in mice. VB12 pretreatment and posttreatment dramatically increased ATP levels in pancreatic tissues and reduced the necrosis, then the elevated levels of amylase in serum, the levels of CK-19, the activity of trypsin, and T lymphocyte infiltration in pancreatic tissues, prevented the pancreatic gross loss and ameliorated histopathological changes of mouse pancreases with induced acute pancreatitis. The results reveal that VB12 is potential as a therapeutic agent to inhibit tissue injuries and adaptive inflammatory responses in the pancreas in patients with acute pancreatitis.

Association Between Orthostatic Hypotension With Coronary Slow Flow in Patients With Chest Pain: A Single Center Experience

BACKGROUND

Orthostatic hypotension (OH) is associated with different cardiovascular diseases, however, the association between OH and coronary slow flow (CSF) has never been evaluated before.

MATERIALS AND METHODS

Chest pain patients who underwent coronary angiography (CAG) and with normal coronary arteries in our department from January 1st, 2022 to August 31st, 2023 were retrospectively enrolled. Patients were divided into the CSF group and the normal blood flow (NBF) group. Relative clinical information, laboratory test results as well as the results of CAG were collected and analyzed. Both uni-variable and multi-variable logistic regression analyses were used to evaluate the association between OH and CSF in these patients.

RESULTS

Four thousand six hundred and twenty-seven patients underwent CAG and 655 patients had normal coronary arteries. In which, sixty-nine patients were diagnosed with CSF while 586 patients were diagnosed with NBF. Uni-variable analysis revealed that higher body weight index, faster heart rate in sitting position, accompanied with chronic kidney disease, did not take Antidiabetic therapy, higher level of aspartate transaminase, uric acid, triglyceride, total cholesterol, ApoB1, low-density lipoprotein cholesterol, homocysteine, B-type natriuretic peptide as well as OH are the risk factors for CSF in these patients. Multi-variable logistic regressing analysis further demonstrated that OH was the independent risk factor for predicting CSF in these patients.

CONCLUSIONS

Our finding suggests OH might be a useful predictor for CSF in patients with chest pain but normal coronary arteries.

The Molecular Bases of Anti-Oxidative and Anti-Inflammatory Properties of Paraoxonase 1

The anti-oxidative and anti-inflammatory properties of high-density lipoprotein (HDL) are thought to be mediated by paraoxonase 1 (PON1), a calcium-dependent hydrolytic enzyme carried on a subfraction of HDL that also carries other anti-oxidative and anti-inflammatory proteins. In humans and mice, low PON1 activity is associated with elevated oxidized lipids and homocysteine (Hcy)-thiolactone, as well as proteins that are modified by these metabolites, which can cause oxidative stress and inflammation. PON1-dependent metabolic changes can lead to atherothrombotic cardiovascular disease, Alzheimer's disease, and cancer. The molecular bases underlying these associations are not fully understood. Biochemical, proteomic, and metabolic studies have significantly expanded our understanding of the mechanisms by which low PON1 leads to disease and high PON1 is protective. The studies discussed in this review highlight the changes in gene expression affecting proteostasis as a cause of the pro-oxidative and pro-inflammatory phenotypes associated with attenuated PON1 activity. Accumulating evidence supports the conclusion that PON1 regulates the expression of anti-oxidative and anti-inflammatory proteins, and that the disruption of these processes leads to disease.

Establishment of a prediction model for venous thromboembolism in patients with acute exacerbation of chronic obstructive pulmonary disease based on serum homocysteine levels and Wells scores: a retrospective cohort study

BACKGROUND

We evaluated the diagnostic value of homocysteine (Hcy) levels combined with the Wells score and established a prediction model for venous thromboembolism (VTE) occurrence in patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPD) based on the Hcy level and the Wells score.

PATIENTS AND METHODS

Clinical information from 914 patients with AECOPD was retrospectively collected in our hospital from June 2020 to October 2023. Receiver operating characteristic curves were plotted to evaluate the diagnostic ability of Hcy concentrations combined with Wells scores and the prediction ability of the model. Univariate and multivariate logistic regressions were used to explore the effects of Hcy levels and the Wells score on VTE occurrence. A nomogram was established for individual risk evaluation.

RESULTS

Hcy levels and Wells scores were significantly greater in the VTE group than in the non-VTE group (P < 0.001). The diagnostic ability of Hcy levels combined with the Wells score was greater than that Hcy levels or the Wells score alone. The AUC of the combined parameters was 0.935, with a sensitivity of 0.864 and a specificity of 0.855. Multivariate logistic regression indicated that elevated Hcy levels (OR:5.17, 95%CI: 3.76-7.09, P < 0.001) and Wells score (OR: 5.26, 95%CI: 3.22-8.59, P < 0.001) were independently associated with the risk of developing VTE in AECOPD patients. Decision curve analysis indicated that the net benefit of the nonadherence prediction nomogram was greater than that of the models adjusted for no or all variables, with a threshold of approximately 0.1-1.0.

CONCLUSIONS

The established prediction model can be used to evaluate an individual's risk of developing VTE on the basis of the Hcy level, Wells score, and clinical parameters. AECOPD patients may benefit from the early intervention based on estimated risk probability.

SDIMMMER: A Proposed Clinical Approach to Optimize Cellular Physiology in Regenerative Medicine

SDIMMMER is an acronym intended for use in both clinical practice and medical research. It facilitates a comprehensive evaluation of a patient's metabolic profile and serves as a mnemonic for the following key assessment areas: Sleep, Diet, Microbiome, Metabolism, Medications, Exams, and Rehabilitation. In the clinical setting, SDIMMMER's primary objective is to monitor and manage the patient's metabolic status, particularly targeting low-grade chronic systemic inflammation, a hallmark of metabolic syndrome (MS). This inflammatory condition is characterized by elevated levels of circulating inflammatory cytokines and increased macrophage infiltration in peripheral tissues. SDIMMMER aims to enhance the effectiveness of ortho biological treatments by elevating growth factor levels, thereby enhancing patient outcomes. Additionally, SDIMMMER emphasizes guiding patients toward positive lifestyle changes to improve overall quality of life and foster a healthier metabolism. SDIMMMER introduces a patient metabolic profile quantification tool comprising 7 domains, totaling 35 items. Additionally, an instructional guide is provided to facilitate the application process. Its versatility spans various clinical and research domains, showcasing its potential to positively influence multiple fields.

Development of a chemiluminescent immunoassay based on magnetic solid phase for quantification of homocysteine in human serum

BACKGROUND

Homocysteine (HCY) is a sulfur-containing amino acid that is an independent or important risk factor for the occurrence of many chronic diseases and is one of the most important indicators for determining health risks. However, existing HCY detection methods do not meet the requirements of clinical diagnosis. Therefore, there is an urgent need to establish new detection methods to meet the needs of clinical detection.

RESULTS

In this study, we used the principle of competitive method to establish a new method for the determination of HCY in human serum using a chemiluminescent enzyme immunoassay in conjunction with a chemiluminescent assay instrument that uses magnetic microparticles as the solid phase of the immunoreaction. The established method achieved satisfactory results in terms of minimum detection limit, specificity, accuracy, and clinical application. The limit of detection was 0.03 ng/mL. The intra-assay coefficient of variation (CV) was 1.94-5.05%, the inter-assay CV was 2.29-6.88%, and the recovery rate was 88.60-93.27%. Cross-reactivity with L-cysteine ranged from 0.0100 to 0.0200 μmol/L, and cross-reactivity with glutathione ranged from 0.0100 to 0.200 μmol/L, all of which were less than the limit of detection (LoD) of this method. The linear factor R of this method was greater than 0.99.

CONCLUSIONS

In summary, the developed method showed a good correlation with the product from Abbott. A total of 996 clinical patients with cardiovascular diseases were evaluated using the method developed in this study.

High Homocysteine-Thiolactone Leads to Reduced MENIN Protein Expression and an Impaired DNA Damage Response: Implications for Neural Tube Defects

DNA damage is associated with hyperhomocysteinemia (HHcy) and neural tube defects (NTDs). Additionally, HHcy is a risk factor for NTDs. Therefore, this study examined whether DNA damage is involved in HHcy-induced NTDs and investigated the underlying pathological mechanisms involved. Embryonic day 9 (E9) mouse neuroectoderm cells (NE4C) and homocysteine-thiolactone (HTL, active metabolite of Hcy)-induced NTD chicken embryos were studied by Western blotting, immunofluorescence. RNA interference or gene overexpression techniques were employed to investigate the impact of Menin expression changes on the DNA damage. Chromatin immunoprecipitation-quantitative polymerase chain reaction was used to investigate the epigenetic regulation of histone modifications. An increase in γH2AX (a DNA damage indicator) was detected in HTL-induced NTD chicken embryos and HTL-treated NE4C, accompanied by dysregulation of phospho-Atr-Chk1-nucleotide excision repair (NER) pathway. Further investigation, based on previous research, revealed that disruption of NER was subject to the epigenetic regulation of low-expressed Menin-H3K4me3. Overexpression of Menin or supplementation with folic acid in HTL-treated NE4C reversed the adverse effects caused by high HTL. Additionally, by overexpressing the Mars gene, we tentatively propose a mechanism whereby HTL regulates Menin expression through H3K79hcy, which subsequently influences H3K4me3 modifications, reflecting an interaction between histone modifications. Finally, in 10 human fetal NTDs with HHcy, we detected a decrease in the expression of Menin-H3K4me3 and disorder in the NER pathway, which to some extent validated our proposed mechanism. The present study demonstrated that the decreased expression of Menin in high HTL downregulated H3K4me3 modifications, further weakening the Atr-Chk1-NER pathway, resulting in the occurrence of NTDs.

Elevated homocysteine is associated with increased rates of epigenetic aging in a population with mild cognitive impairment

Elevated plasma total homocysteine (tHcy) is associated with the development of Alzheimer's disease and other forms of dementia. In this study, we report the relationship between tHcy and epigenetic age in older adults with mild cognitive impairment from the VITACOG study. Epigenetic age and rate of aging (ROA) were assessed using various epigenetic clocks, including those developed by Horvath and Hannum, DNAmPhenoAge, and with a focus on Index, a new principal component-based epigenetic clock that, like DNAmPhenoAge, is trained to predict an individual's "PhenoAge." We identified significant associations between tHcy levels and ROA, suggesting that hyperhomocysteinemic individuals were aging at a faster rate. Moreover, Index revealed a normalization of accelerated epigenetic aging in these individuals following treatment with tHcy-lowering B-vitamins. Our results indicate that elevated tHcy is a risk factor for accelerated epigenetic aging, and this can be ameliorated with B-vitamins. These findings have broad relevance for the sizable proportion of the worldwide population with elevated tHcy.

Homocysteine metabolites impair the PHF8/H4K20me1/mTOR/autophagy pathway by upregulating the expression of histone demethylase PHF8-targeting microRNAs in human vascular endothelial cells and mice

The inability to efficiently metabolize homocysteine (Hcy) due to nutritional and genetic deficiencies, leads to hyperhomocysteinemia (HHcy) and endothelial dysfunction, a hallmark of atherosclerosis which underpins cardiovascular disease (CVD). PHF8 is a histone demethylase that demethylates H4K20me1, which affects the mammalian target of rapamycin (mTOR) signaling and autophagy, processes that play important roles in CVD. PHF8 is regulated by microRNA (miR) such as miR-22-3p and miR-1229-3p. Biochemically, HHcy is characterized by elevated levels of Hcy, Hcy-thiolactone and N-Hcy-protein. Here, we examined the effects of these metabolites on miR-22-3p, miR-1229-3p, and their target PHF8, as well as on the downstream consequences of these effects on H4K20me1, mTOR-, and autophagy-related proteins and mRNAs expression in human umbilical vein endothelial cells (HUVEC). We found that treatments with N-Hcy-protein, Hcy-thiolactone, or Hcy upregulated miR-22-3p and miR-1229-3p, attenuated PHF8 expression, upregulated H4K20me1, mTOR, and phospho-mTOR. Autophagy-related proteins (BECN1, ATG5, ATG7, lipidated LC3-II, and LC3-II/LC3-I ratio) were significantly downregulated by at least one of these metabolites. We also found similar changes in the expression of miR-22-3p, Phf8, mTOR- and autophagy-related proteins/mRNAs in vivo in hearts of Cbs-/- mice, which show severe HHcy and endothelial dysfunction. Treatments with inhibitors of miR-22-3p or miR-1229-3p abrogated the effects of Hcy-thiolactone, N-Hcy-protein, and Hcy on miR expression and on PHF8, H4K20me1, mTOR-, and autophagy-related proteins/mRNAs in HUVEC. Taken together, these findings show that Hcy metabolites upregulate miR-22-3p and miR-1229-3p expression, which then dysregulate the PHF8/H4K20me1/mTOR/autophagy pathway, important for vascular homeostasis.

Novel long noncoding lncARF mediated hyperhomocysteinemia-induced atherosclerosis via autophagy inhibition in foam cells

INTRODUCTION

Homocysteine (Hcy) is well recognized to be an independent risk factor for atherosclerosis. Long non-coding RNAs (lncRNAs) are emerging regulators of pathophysiological processes including atherosclerosis, while the underlying mechanisms of its involvement in Hcy induced-atherosclerosis remain largely unknown.

OBJECTIVES

The primary aim of this study is to assess the role of lncARF (autophagy-related factor induced by Hcy) in Hcy induced-atherosclerosis and related mechanism.

METHODS

RNA sequencing of foam cells treated with Hcy revealed a novel specific long noncoding RNA called lncARF. Locked nucleic acid gapmeRs-mediated lncARF knockdown was used to explore the role of lncARF both in vivo and in vitro. Mass spectrometry, RNA pull-down and RNA immunoprecipitation (RIP) assays were employed to uncover a mechanistic role of lncARF. Mass array assay and chromatin immunoprecipitation (ChIP) were used to detect the transcriptional activation of lncARF mediated by transcription factor. Clinically, receiver operating characteristic (ROC) curve analysis was used to assess the diagnostic value of lncARF in atherosclerotic patients with hyperhomocysteinemia (HHcy).

RESULTS

We observed that the expression of lncARF was substantially upregulated in atherosclerotic plaques, and knockdown of lncARF decreased the formation of atherosclerotic lesions by promoting autophagy in foam cells. Mechanistically, lncARF physically binds to RRAGD and inhibits its ubiquitination, further activating the PI3K/Akt and MAPK signaling pathways. Moreover, in vitro experiments showed that transcription factor FosB inhibited the binding of DNMT1 at the lncARF promoter, leading to transcriptional activation through DNA hypomethylation. Clinically, lncARF expression was positively correlated with serum Hcy levels, and it could distinguish atherosclerotic patients with HHcy with a high area under the ROC curve, sensitivity and specificity.

CONCLUSIONS

Our study highlights the mechanisms of lncARF in protecting against the development of atherosclerosis involving the epigenetic modifications and RRAGD/PI3K/Akt and RRAGD/MAPK signaling pathways, which may provide novel diagnostic biomarkers to improve atherosclerosis treatment.

Homocysteine, blood pressure and gene-diet interactions in relation to vascular function measures of black South Africans

BACKGROUND AND AIMS

We investigated circulating homocysteine (Hcy), a cardiovascular disease (CVD) risk factor, examining its dietary associations to provide personalized nutrition advice. This study addressed the inadequacy of current dietary interventions to ultimately address the disproportionately high incidence of CVD in Black populations.

METHODS AND RESULTS

Cross-sectional analyses of 1,867 Black individuals of the PURE-SA study allowed the identification of dietary intake and cardiovascular measure interactions on three sub-categories: (1) normal blood pressure (BP), hypertension or Hcy-related hypertension (H-type), (2) low, normal or high Hcy concentrations, and (3) Hcy-related genetic combinations. Favorable body composition, but adverse dietary intake and cardiovascular determinants, were observed in higher Hcy categories. H-types, compared to regular hypertensives, had higher alcohol and lower macronutrient and micronutrient consumption. Inverse associations with carotid-radial pulse wave velocity were evident between monounsaturated fatty acid (FA) consumption and H-type hypertension as well as polyunsaturated FA and CBS883/ins68 TT carriers. Energy intake was positively associated with vascular cell adhesion molecule-1 (VCAM-1) in variant CBST883C/ins68 and CBS9276 GG carriers. VCAM-1 was also positively associated with plant protein intake in CBS9276 GG and MTR2756 AA carriers and negatively with total protein intake and CBS9276 GG carriers. Alcohol intake was positively associated with intercellular adhesion molecule-1 in MTR2756 minor allele carriers.

CONCLUSION

Because Hcy gene-diet interactions are evident, personalized nutrition, by adjusting diets based on genetic profiles (e.g., CBS and MTR variations) and dietary interactions (e.g., FAs and proteins), can enhance cardiovascular outcomes by managing Hcy and related hypertension in genetically susceptible individuals.

Mitigating Traumatic Brain Injury: A Narrative Review of Supplementation and Dietary Protocols

Traumatic brain injuries (TBIs) constitute a significant public health issue and a major source of disability and death in the United States and worldwide. TBIs are strongly associated with high morbidity and mortality rates, resulting in a host of negative health outcomes and long-term complications and placing a heavy financial burden on healthcare systems. One promising avenue for the prevention and treatment of brain injuries is the design of TBI-specific supplementation and dietary protocols centred around nutraceuticals and biochemical compounds whose mechanisms of action have been shown to interfere with, and potentially alleviate, some of the neurophysiological processes triggered by TBI. For example, evidence suggests that creatine monohydrate and omega-3 fatty acids (DHA and EPA) help decrease inflammation, reduce neural damage and maintain adequate energy supply to the brain following injury. Similarly, melatonin supplementation may improve some of the sleep disturbances often experienced post-TBI. The scope of this narrative review is to summarise the available literature on the neuroprotective effects of selected nutrients in the context of TBI-related outcomes and provide an evidence-based overview of supplementation and dietary protocols that may be considered in individuals affected by-or at high risk for-concussion and more severe head traumas. Prophylactic and/or therapeutic compounds under investigation include creatine monohydrate, omega-3 fatty acids, BCAAs, riboflavin, choline, magnesium, berry anthocyanins, Boswellia serrata, enzogenol, N-Acetylcysteine and melatonin. Results from this analysis are also placed in the context of assessing and addressing important health-related and physiological parameters in the peri-impact period such as premorbid nutrient and metabolic health status, blood glucose regulation and thermoregulation following injury, caffeine consumption and sleep behaviours. As clinical evidence in this research field is rapidly emerging, a comprehensive approach including appropriate nutritional interventions has the potential to mitigate some of the physical, neurological, and emotional damage inflicted by TBIs, promote timely and effective recovery, and inform policymakers in the development of prevention strategies.

Homocysteine Thiolactone Detoxifying Enzymes and Alzheimer's Disease

Elevated levels of homocysteine (Hcy) and related metabolites are associated with Alzheimer's disease (AD). Severe hyperhomocysteinemia causes neurological deficits and worsens behavioral and biochemical traits associated with AD. Although Hcy is precluded from entering the Genetic Code by proofreading mechanisms of aminoacyl-tRNA synthetases, and thus is a non-protein amino acid, it can be attached to proteins via an N-homocysteinylation reaction mediated by Hcy-thiolactone. Because N-homocysteinylation is detrimental to a protein's function and biological integrity, Hcy-thiolactone-detoxifying enzymes-PON1, BLMH, BPHL-have evolved. This narrative review provides an account of the biological function of these enzymes and of the consequences of their impairments, leading to the phenotype characteristic of AD. Overall, accumulating evidence discussed in this review supports a hypothesis that Hcy-thiolactone contributes to neurodegeneration associated with a dysregulated Hcy metabolism.

Is serum homocysteine level a biomarker of suicide attempts: A preliminary study

Suicide is a global public health concern, and understanding its multifaceted determinants is crucial for effective prevention. This study was designed to find an answer to the question of whether serum homocysteine level can be a biomarker of suicide attempts. This preliminary study involving 90 participants (45 suicide attempt cases and 45 controls) was conducted at Elazig Fethi Sekin City Hospital. Biochemical analyses were performed to assess serum homocysteine, vitamin B12, and folic acid levels. Statistical analyses, including t-tests, Mann-Whitney U tests, and ROC analysis, were employed to explore differences between groups and assess the diagnostic potential of homocysteine. Elevated homocysteine levels were found in individuals who attempted suicide compared to the control group (p= <0.001). Additionally, lower levels of vitamin B12 (p=<0.001) and folic acid (p=<0.001) were observed in the suicide attempt group. ROC analysis indicated a significant diagnostic potential for homocysteine in predicting suicide attempts (AUC = 0.845, sensitivity = 91%, specificity = 71%). This study establishes a significant association between high homocysteine levels and suicide attempts, accompanied by lower vitamin B12 and folic acid levels. The findings suggest a potential link between disturbances in homocysteine metabolism and suicidal tendencies, urging further research to establish causation and explore therapeutic implications. Consideration of the study's limitations and directions for future research are warranted.

Increased thyroid stimulating hormone (TSH) as a possible risk factor for atherosclerosis in subclinical hypothyroidism

Primary hypothyroidism (PHT) is associated with an increased risk for the development of atherosclerosis (AS) and other cardiovascular disorders. PHT induces atherosclerosis (AS) through the induction of endothelial dysfunction, and insulin resistance (IR). PHT promotes vasoconstriction and the development of hypertension. However, patients with subclinical PHT with normal thyroid hormones (THs) are also at risk for cardiovascular complications. In subclinical PHT, increasing thyroid stimulating hormone (TSH) levels could be one of the causative factors intricate in the progression of cardiovascular complications including AS. Nevertheless, the mechanistic role of PHT in AS has not been fully clarified in relation to increased TSH. Therefore, in this review, we discuss the association between increased TSH and AS, and how increased TSH may be involved in the pathogenesis of AS. In addition, we also discuss how L-thyroxine treatment affects the development of AS.

Serum S-adenosylhomocysteine levels are associated with first stroke in Chinese adults with hypertension

BACKGROUND

The association between S-adenosylhomocysteine (SAH) and stroke has not been confirmed due to the specialized equipment and time requirements necessary for S-adenosylhomocysteine testing. We aimed to explore the association between SAH and stroke.

METHODS

A nested, case-control study drawn from the China Stroke Primary Prevention Trial of rural adults with hypertension, including 557 first stroke cases and 557 matched controls was conducted. Serum SAH was measured by stable-isotope dilution liquid chromatography-tandem mass spectrometry using 4500MD. Multiple conditional logistic regression models were used to evaluate the association between SAH and first stroke.

RESULTS

In females, SAH levels were significantly higher in the stroke population than in the control group (16.0 ng/mL vs. 14.6 ng/mL). When SAH was assessed as quartiles, the odds of stroke were 1.78 (95 % CI: 1.02-3.09) in Quartile 2, 1.31 (95 % CI: 0.73-2.33) in Quartile 3, and 1.93 (95 % CI: 1.03-3.62) in Quartile 4, compared to Quartile 1. When Quartiles 2-4 were combined, the adjusted odds ratio of first stroke was 1.64 (95 % CI: 1.03-2.62) compared with Quartile 1. In subgroup analysis, a significant SAH-stroke association was observed in the lower vitamin D3 group (OR = 3.35, 95 % CI:1.72-6.53; P interaction, 0.035). In males, higher levels of SAH were associated with an increased risk of stroke in those under age 60. Compared with the reference group, the adjusted odds ratio of total stroke was 2.40 (95 % CI: 1.02-5.91) in the combined group (Quartile 2-4). In contrast, no significant association between SAH and stroke was found in males aged 60 or older.

CONCLUSIONS

This study reveals that SAH is associated with a higher risk of stroke independently of homocysteine, especially in females. SAH may be a second predictor of stroke in the metabolic pathway of methionine, after homocysteine.

Evaluation of anti-seizure medications and their serum concentration with regard to cardiovascular risk parameters: A cross-sectional study

OBJECTIVE

Epilepsy is a chronic disease that requires long-term monitoring and treatment. It is suspected that there is a interaction between the use of anti-seizure medications and the risk of cardiovascular disease. The aim of the study is to investigate the association between the intake of phenobarbital, carbamazepine and valproic acid and their serum drug concentrations (SDC) with various cardiovascular risk parameters (homocysteine, folic acid, vitamin B12, total cholesterol (TC), triglycerides, high- and low-density lipoprotein (LDL)).

METHODS

This is a cross-sectional study. Data (demographic characteristics and laboratory results) of patients treated for epilepsy in a tertiary care hospital between January 2020 and February 2022 were analyzed retrospectively (n = 2014). Kruskal Wallis, Mann-Whitney U, correlation analysis was used, p < 0.05 was considered statistically significant.

RESULTS

The median age of patients was 15 years (IQR:8-31) and 48.3 % were women. The highest homocysteine level was found in patients receiving valproic acid, but it was not statistically significant. Patients receiving phenobarbital had the highest levels of folic acid and B12 and the lowest levels of total cholesterol and low-density lipoprotein cholesterol, which was statistically significant. In patients receiving carbamazepine, a moderately negative significant association was found between serum drug concentration and folic acid levels and a moderately positive significant association was found between TC and LDL levels.

CONCLUSION

In our study, the majority of patients were children and adolescents. Regular monitoring of drug serum concentrations and metabolic parameters may be useful to select the safest drug in terms of cardiovascular disease risk. Randomized controlled trials on the long-term effects of anti-seizure treatment are needed.

Association of vitamin B12, folate, and homocysteine with COVID-19 severity and mortality: A systematic review and meta-analysis

Objective

We aimed to review the available evidence on the association between vitamin B12, folate, and homocysteine levels with worse outcomes among COVID-19 patients.

Methods

The search was carried out in ten databases simultaneously run on 10 May 2023, without language restrictions. We included cross-sectional, case-control, and cohort studies. The random-effects meta-analysis was performed using the Sidik-Jonkman method and corrected 95% confidence intervals using the truncated Knapp-Hartung standard errors. Standardized mean difference and 95% CI was used as the measure effect size.

Results

Thirteen articles were included in this review (n = 2134). Patients with COVID-19 who did not survive had the highest serum vitamin B12 values (SMD: 1.05; 95% CI: 0.31-1.78; p = 0.01, I2 = 91.22%). In contrast, low serum folate values were associated with patients with severe COVID-19 (SMD: -0.77; 95% CI: -1.35 to -0.19; p = 0.02, I2 = 59.09%). The remaining tested differences did not yield significant results.

Conclusion

Elevated serum levels of vitamin B12 were associated with higher mortality in patients with COVID-19. Severe cases of COVID-19 were associated with low serum folate levels. Future studies should incorporate a larger sample size.

Homocysteine thiolactone and other sulfur-containing amino acid metabolites are associated with fibrin clot properties and the risk of ischemic stroke

Homocysteine (Hcy) and Hcy-thiolactone (HTL) affect fibrin clot properties and are linked to cardiovascular disease. Factors that influence fibrin clot properties and stroke are not fully understood. To study sulfur-containing amino acid metabolites, fibrin clot lysis time (CLT) and maximum absorbance (Absmax) in relation to stroke, we analyzed plasma and urine from 191 stroke patients (45.0% women, age 68 ± 12 years) and 291 healthy individuals (59.7% women, age 50 ± 17 years). Plasma and urinary levels of sulfur-containing amino acid metabolites and fibrin clot properties were significantly different in stroke patients compared to healthy individuals. Fibrin CLT correlated with fibrin Absmax in healthy males (R2 = 0.439, P = 0.000), females (R2 = 0.245, P = 0.000), female stroke patients (R2 = 0.187, P = 0.000), but not in male stroke patients (R2 = 0.008, P = ns). Fibrin CLT correlated with age in healthy females but not males while fibrin Absmax correlated with age in both sexes; these correlations were absent in stroke patients. In multiple regression analysis in stroke patients, plasma (p)CysGly, pMet, and MTHFR A1298C polymorphism were associated with fibrin Absmax, while urinary (u)HTL, uCysGly, and pCysGly were significantly associated with fibrin CLT. In healthy individuals, uHTL and uGSH were significantly associated with fibrin Absmax, while pGSH, and CBS T833C 844ins68 polymorphism were associated with fibrin CLT. In logistic regression, uHTL, uHcy, pCysGly, pGSH, MTHFR C677T polymorphism, and Absmax were independently associated with stroke. Our findings suggest that HTL and other sulfur-containing amino acid metabolites influence fibrin clot properties and the risk of stroke.

A comprehensive review and meta-regression analysis of randomized controlled trials examining the impact of vitamin B12 supplementation on homocysteine levels

CONTEXT

Although some research suggests that vitamin B12 (hereafter, B12) supplements can lower homocysteine (Hcy) levels and treat hyperhomocysteinemia, these results are still ambiguous when B12 is taken as an isolated supplement.

OBJECTIVE

This study sought to determine how existing randomized controlled trials (RCTs) could be used to examine the effects of B12 supplementation on Hcy.

DATA SOURCES

To find pertinent RCTs up to June 2022, databases, including PubMed/Medline, Web of Science, Scopus, Cochrane Library, and Embase, were searched.

DATA EXTRACTION

All selected RCTs investigated the impact of B12 supplements on Hcy. A meta-analysis of the eligible studies was performed using the random-effects model.

DATA ANALYSIS

This review included a total of 21 RCTs (N = 1625 participants). Hcy levels were significantly lower after B12 supplementation compared with the control group (pooled weighted mean difference, -4.15 μmol/L; 95% confidence interval, -4.86, -3.45; P < 0.001), and this reduction was even greater with intervention durations ≥12 weeks and doses >500 µg/d. Furthermore, the effect of B12 supplementation in the form of hydroxocobalamin on the reduction of Hcy level was greater compared with other forms.

CONCLUSION

In conclusion, this meta-analysis shows that B12 supplementation has a positive impact on lowering blood Hcy levels, particularly when administered for a longer period and at a larger dose.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42022364066.

A label-free and washing-free method to detect biological thiols on a personal glucose meter utilizing glucose oxidase-mimicking activity of gold nanoparticles

We herein developed a label-free and washing-free method to detect biological thiols (biothiols) on a personal glucose meter (PGM) utilizing the intrinsic glucose oxidase (GOx)-mimicking activity of gold nanoparticles (AuNPs). By focusing on the fact that this activity could be diminished by target biothiols through their binding onto the AuNP surface, we correlated the concentration of biothiols with that of glucose readily measurable on a PGM and successfully determined cysteine (Cys), homocysteine (Hcy), and glutathione (GSH) down to 0.116, 0.059, and 0.133 μM, respectively, with high specificity against non-target biomolecules. We further demonstrated its practical applicability by reliably detecting target biothiol in heterogeneous human serum. Due to the meritorious features of PGM such as simplicity, portability, and cost-effectiveness, we believe that this work could serve as a powerful platform for biothiol detection in point-of-care settings.

Exploring research hotspots and future directions in neural tube defects field by bibliometric and bioinformatics analysis

Background

Neural tube defects (NTDs) is the most common birth defect of the central nervous system (CNS) which causes the death of almost 88,000 people every year around the world. Much efforts have been made to investigate the reasons that contribute to NTD and explore new ways to for prevention. We trawl the past decade (2013-2022) published records in order to get a worldwide view about NTDs research field.

Methods

7,437 records about NTDs were retrieved from the Web of Science (WOS) database. Tools such as shell scripts, VOSviewer, SCImago Graphica, CiteSpace and PubTator were used for data analysis and visualization.

Results

Over the past decade, the number of publications has maintained an upward trend, except for 2022. The United States is the country with the highest number of publications and also with the closest collaboration with other countries. Baylor College of Medicine has the closest collaboration with other institutions worldwide and also was the most prolific institution. In the field of NTDs, research focuses on molecular mechanisms such as genes and signaling pathways related to folate metabolism, neurogenic diseases caused by neural tube closure disorders such as myelomeningocele and spina bifida, and prevention and treatment such as folate supplementation and surgical procedures. Most NTDs related genes are related to development, cell projection parts, and molecular binding. These genes are mainly concentrated in cancer, Wnt, MAPK, PI3K-Akt and other signaling pathways. The distribution of NTDs related SNPs on chromosomes 1, 3, 5, 11, 14, and 17 are relatively concentrated, which may be associated with high-risk of NTDs.

Conclusion

Bibliometric analysis of the literature on NTDs field provided the current status, hotspots and future directions to some extant. Further bioinformatics analysis expanded our understanding of NTDs-related genes function and revealed some important SNP clusters and loci. This study provided some guidance for further studies. More extensive cooperation and further research are needed to overcome the ongoing challenge in pathogenesis, prevention and treatment of NTDs.

A micronutrient supplement modulates homocysteine levels regardless of vitamin B biostatus in elderly subjects

Elevated homocysteine (Hcy) levels (≥15 μmol/L) in the elderly are frequently associated with a higher risk of cardiovascular disease and cognitive decline. Several studies have already shown an Hcy-lowering effect of B vitamin supplementation in cohorts deficient in these nutrients. The aim of this randomized, double-blinded 12-week intervention study was to investigate whether Hcy levels in healthy elderly subjects (75.4±4.5 years, n=133) could be lowered with a micronutrient supplement (i.e., 400 μg folic acid, 100 μg cobalamin). Difference in mean initial Hcy levels between intervention (17.6±7.1 μmol/L, n=65) and placebo group (18.9±6.1 μmol/L, n=68) was not significant. The prevalence of cobalamin and folate deficiency in the total study population was low: 27% had serum-cobalamin levels ≤150 pmol/L, 12% holo-transcobalamin (Holo-TC) levels ≤50 pmol/L, 13% low cobalamin status using the aggregated cobalamin marker 4cB12 and 10% red blood cell (RBC) folate ≤570 nmol/L. Nevertheless, the treated subjects still showed improved cobalamin and folate biostatus (serum cobalamin Δt12-t0: 63±48 pmol/L; Holo-TC Δt12-t0: 17±19 pmol/L; RBC folate Δt12-t0: 326±253 nmol/L) and Hcy levels (Δt12-t0: -3.6±5.7 μmol/L). The effects were statistically significant compared to the placebo group with p=0.005 (serum cobalamin), p=0.021 (Holo-TC), p=0.014 (RBC-folate) and p<0.001 (Hcy). The Hcy-lowering effect was dependent on the initial Hcy levels (p<0.001). Our findings suggest that elevated Hcy levels in elderly subjects can be lowered regardless of the initial cobalamin and folate biostatus.

Plasma levels of hydrogen sulfide and homocysteine correlate with the efficacy of antidepressant agents and serve as potential diagnostic and therapeutic markers

OBJECTIVE

Hydrogen sulfide (H2S) is associated with depressive-like behavior in rodents. We undertook cross-sectional and longitudinal analyses of plasma levels of H2S and its substrate homocysteine (Hcy) in depression and assessed the association of both parameters with psychopathology and cognitive function.

METHODS

Forty-one patients suffering from depression (PSDs) and 48 healthy volunteers were recruited. PSDs were treated for 8 weeks. Analyzable data were collected from all participants for assessment of their psychopathology and cognitive function. Plasma was collected for determination of levels of H2S and Hcy, and data were correlated to determine their potential as plasma biomarkers.

RESULTS

Cross-sectional analyses revealed PSDs to have a low plasma H2S level and high Hcy level. Longitudinal analyses revealed that 8 weeks of treatment reversed the changes in plasma levels of H2S and Hcy in PSDs. Plasma levels of H2S and Hcy were associated with psychopathology and cognitive function in depression. The area under the receiver operating characteristic curve (AUC) for a combination of plasma levels of H2S and Hcy and expression of the TNF gene (i.e., H2S-Hcy-TNF) was 0.848 for diagnosing depression and 0.977 for predicting the efficacy of antidepressant agents.

CONCLUSION

Plasma levels of H2S and Hcy reflect changes in psychopathology and cognitive function in depression and H2S-Hcy-TNF has the potential to diagnose depression and predict the efficacy of antidepressant medications.

Dosage exploration of combined B-vitamin supplementation in stroke prevention: a meta-analysis and systematic review

BACKGROUND

The optimal dosage range for B-vitamin supplementation for stroke prevention has not received sufficient attention.

OBJECTIVE

Our aim was to determine the optimal dosage range of a combination of folic acid, vitamin B12, and vitamin B6 supplementation in stroke prevention.

METHODS

We searched PubMed, the Cochrane Central Register of Controlled Trials, and Embase database for randomized controlled trials published between January 1966 and April 2023, whose participants received B-vitamin supplementation and that reported the number of stroke cases. Relative risk (RR) was used to measure the effect of combined supplementation on risk of stroke using a fixed-effects model. Risk of bias was assessed with the Cochrane risk-of-bias algorithm.

RESULTS

The search identified 14 randomized controlled trials of folic acid combined with vitamin B12 and vitamin B6 supplementation for stroke prevention that included 76,664 participants with 2720 stroke cases. In areas without and with partial folic acid fortification, combined B-vitamin supplementation significantly reduced the risk of stroke by 34% [RR: 0.66; 95% confidence interval (CI): 0.50, 0.86] and 11% (RR: 0.89; 95% CI: 0.79, 1.00), respectively. Further analysis showed that a dosage of folic acid ≤0.8 mg/d and vitamin B12 ≤0.4 mg/d was best for stroke prevention (RR: 0.65; 95% CI: 0.48, 0.86) in these areas. In contrast, no benefit of combined supplementation was found in fortified areas (RR: 1.04; 95% CI: 0.94, 1.16).

CONCLUSIONS

Our meta-analysis found that the folic acid combined with vitamin B12 and vitamin B6 supplementation strategy significantly reduced the risk of stroke in areas without and with partial folic acid fortification. Combined dosages not exceeding 0.8 mg/d for folic acid and 0.4 mg/d for vitamin B12 supplementation may be more effective for populations within these areas. This trial was registered at PROSPERO asCRD42022355077.

Association of Increased Homocysteine Levels with Impaired Folate Metabolism and Vitamin B Deficiency in Early-Onset Multiple Sclerosis

The contents of homocysteine (HCy), cyanocobalamin (vitamin B12), folic acid (vitamin B9), and pyridoxine (vitamin B6) were analyzed and the genotypes of the main gene polymorphisms associated with folate metabolism (C677T and A1298C of the MTHFR gene, A2756G of the MTR gene and A66G of the MTRR gene) were determined in children at the onset of multiple sclerosis (MS) (with disease duration of no more than six months), healthy children under 18 years (control group), healthy adults without neurological pathology, adult patients with MS at the onset of disease, and adult patients with long-term MS. A significant increase in the HCy levels was found in children at the MS onset compared to healthy children of the corresponding age. It was established that the content of HCy in children has a high predictive value. At the same time, an increase in the HCy levels was not accompanied by the deficiency of vitamins B6, B9, and B12 in the blood. The lack of correlation between the laboratory signs of vitamin deficiency and HCy levels may be due to the polymorphic variants of folate cycle genes. An increased HCy level should be considered as a marker of functional disorders of folate metabolism accompanying the development of pathological process in pediatric MS. Our finding can be used to develop new approaches to the prevention of demyelination in children and treatment of pediatric MS.

Association between dietary folate intake and severe headache among adults in the USA: a cross-sectional survey

Folate, also known as vitamin B9, is a water-soluble vitamin. Previous studies on dietary folate intake in severe headache patients were equivocal. Therefore, we conducted a cross-sectional study to elucidate the relationship between folate intake and severe headache. This cross-sectional study used data from participants over 20 years old who participated in the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2004. The diagnosis of severe headache was made through participants' self-report in the NHANES questionnaire section. We performed multivariate logistic regression and restricted cubic spline (RCS) regression to explore the relationship between folate intake and severe headache. A total of 9859 participants took part in the study, 1965 of whom were severe headache patients and the rest were non-severe headache. We found that dietary folate intake was significantly and inversely associated with severe headache. Compared with participants with lower folate intake Q1 (≤ 229·97 ug/d), the adjusted OR values for dietary folate intake and severe headache in Q2 (229·98-337 ug/d), Q3 (337·01-485 ug/d) and Q4 (≥ 485·01 ug/d) were 0·81 (95 % CI: 0·67, 0·98, P = 0·03), 0·93 (95 % CI: 0·77, 1·12, P = 0·41) and 0·63 (95 % CI: 0·49, 0·80, P < 0·001), respectively. For women aged 20-50 years, there was a non-linear association between folate intake and severe headache in the RCS. Women aged 20-50 years should have higher awareness of dietary folate and increase their dietary intake of folate, which may aid in preventing severe headache.

Linking biomarkers with healthy lifestyle outcomes after stroke: Supplementary results of a 12-month randomized controlled trial

BACKGROUND AND AIMS

Participation in a healthy lifestyle intervention such as the Diabetes Prevention Program Group Lifestyle Balance-adapted for stroke (GLB-CVA) may reduce stroke burden. Identifying biomarkers associated with lifestyle changes may enhance an individualized approach to stroke recovery. We investigated metabolic biomarkers related to cardiovascular and neurological function in individuals with stroke in the GLB-CVA study and healthy (non-stroke) individuals.

METHODS AND RESULTS

Participants with chronic (>12 months) stroke were recruited to this wait-list randomized controlled trial if they were overweight (BMI ≥25 kg/m2). Participants were randomized to (1) the GLB-CVA program to complete 22 educational sessions addressing behavioral principals of dietary and physical activity or (2) a 6 month wait-list control (WLC). Biomarkers [Plasma irisin, vascular endothelial growth factor, lipoprotein-associated phospholipase A2 (Lp-PLA2), insulin-like growth factor 1 and brain-derived neurotrophic factor (BDNF)] were collected at baseline, 3, and 6 months. Age-matched healthy individuals were recruited for biomarker assessment. Compared to healthy adults (n = 19), participants with stroke (GLB-CVA = 24; WLC = 24) at baseline had higher tHcy levels (p < 0.001) and lower PLA2 levels (p = 0.016). No statistically significant interactions were observed for any biomarkers between the GLB-CVA and WLC or between people who achieved 5% weight loss and those who did not.

CONCLUSION

Participation in a 6-month healthy lifestyle program did not result in statistically significant changes to select metabolic biomarker levels for our participants with chronic stroke. However, participants with stroke demonstrated a unique biomarker profile compared to age-matched healthy individuals.

Oxidative stress in acute pulmonary embolism: emerging roles and therapeutic implications

Oxidative stress is an imbalance between the body's reactive oxygen species and antioxidant defense mechanisms. Oxidative stress is involved in the development of several cardiovascular diseases, such as pulmonary hypertension, atherosclerosis, and diabetes mellitus. A growing number of studies have suggested the potential role of oxidative stress in the pathogenesis of pulmonary embolism. Biomarkers of oxidative stress in pulmonary embolism have also been explored, such as matrix metalloproteinases, asymmetric dimethylarginine, and neutrophil/lymphocyte ratio. Here, we comprehensively summarize some oxidative stress mechanisms and biomarkers in the development of acute pulmonary embolism and summarize related treatments based on antioxidant stress to explore effective treatment strategies for acute pulmonary embolism.

Relationships of B12 and Homocysteine with Outcomes in the SURE-PD, SURE-PD3, and STEADY-PDIII Trials

Background

DATATOP was a study of early Parkinson's disease (PD) conducted in the 1980 s, before mandatory folic acid fortification in the United States. Our analysis of its baseline serum samples revealed a geometric mean vitamin B12 of 369 pg/mL and homocysteine (tHcy) of 9.5μmol/l. We also found that low B12 predicted greater worsening of ambulatory capacity (AC) and elevated tHcy (>15μmol/L) predicted greater declines in cognitive function.

Objective

We sought to measure B12 and tHcy in contemporary trial participants with early PD who had not started dopaminergic treatment and to determine whether these analytes were associated with clinical progression.

Methods

We measured B12 and tHcy from baseline and end-of-study blood samples from three recent clinical trials.

Results

Baseline geometric mean B12 levels for these studies ranged from 484- 618 pg/ml and for tHcy ranged from 7.4- 10μmol/L. Use of B12-containing supplements ranged from 41- 61%, and those taking supplements had higher B12 and lower tHcy. Those who began levodopa, but were not taking B12-supplements, had greater end-of-study tHcy. There was no association of baseline tHcy > 15μmol/L with annualized change in Montreal Cognitive Assessment and no association of baseline B12 tertiles with change in AC.

Conclusions

In these longitudinal trials, B12 levels were higher than for DATATOP, due in large part to increased B12-supplement intake, while tHcy levels were similar. Initiation of levodopa was associated with increases of tHcy in those not taking a B12-containing supplement. These smaller studies did not replicate prior findings of low B12 and elevated tHcy with features of progression, possibly due to higher baseline B12.

Blood Homocysteine Levels Mediate the Association Between Blood Lead Levels and Cardiovascular Mortality

Lead is a heavy, toxic metal and its exposure to humans can lead to increased risk of cardiovascular disease development and mortality. Lead exposure has been shown to induce hyperhomocysteinemia (HHCy) which may be a major pathogenic risk for the risk of CVDs. The aim of this study was to investigate whether homocysteine (Hcy) mediates the effect of lead on cardiovascular mortality. A total of 17,915 adults aged ≥ 20 who participated in the National Health and Nutrition Examination Survey (1999 to 2006). Information on mortality was ascertained via probabilistic matching to the death certificates from the National Death Index recorded up to December 31, 2015. Cox proportional hazards regression was performed to assess the association between blood lead levels and mortality. Mediation via Hcy was examined using a logit model. During a mean follow-up of 11.6 years, the incidences of CVD mortality were 0.73, 2.18, 3.03 and 4.94 per 1000 person-years across quarterlies of blood lead levels from low to high. Following multivariable adjustment, blood lead levels were strongly associated with CVD mortality in all mortality models (p-trend < 0.001). This association remained statistically significant after further adjusting for quartiles of homocysteine (model 3; HR 1.38 (95% CI 1.01-1.89) p-trend < 0.001). Furthermore, blood lead levels increased the odds of CVD mortality via homocysteine (indirect effect) (OR 1.42 (95% CI 1.30-1.55)), demonstrating the mediatory effect of homocysteine. This the first study that demonstrates that increased homocysteine mediates nearly half of CVD mortality related to blood lead levels.

Deciphering prognostic indicators in AQP4-IgG-seropositive neuromyelitis optica spectrum disorder: An integrative review of demographic and laboratory factors

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is a group of inflammatory diseases affecting the central nervous system, characterized by optic neuritis and myelitis. The complex nature of NMOSD and varied patient response necessitates personalized treatment and efficient patient stratification strategies.

OBJECTIVE

To provide a comprehensive review of recent advances in clinical and biomarker research related to aquaporin-4 (AQP4)-immunoglobulin G (IgG)-seropositive NMOSD prognosis and identify key areas for future research.

METHODS

A comprehensive review and synthesis of recent literature were conducted, focusing on demographic factors and laboratory investigations.

RESULTS

Demographic factors, such as age, ethnicity, and sex, influence NMOSD prognosis. Key biomarkers for NMOSD prognosis include homocysteine, antinuclear antibodies, neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, thyroid hormone levels, neurofilament light chain levels, and serum glial fibrillary acidic protein might also predict NMOSD attack prognosis.

CONCLUSION

Further investigation is required to understand sex-related disparities and biomarker inconsistencies. Identification and understanding of these factors can aid in the development of personalized therapeutic strategies, thereby improving outcomes for NMOSD patients. Future studies should focus on unifying research design for consistent results.

The Role of Diet in Parkinson's Disease

The aim of this review is to examine the intersection of Parkinson's disease (PD) with nutrition, to identify best nutritional practices based on current evidence, and to identify gaps in the evidence and suggest future directions. Epidemiological work has linked various dietary patterns and food groups to changes in PD risk; however, fewer studies have evaluated the role of various diets, dietary components, and supplements in the management of established PD. There is substantial interest in exploring the role of diet-related interventions in both symptomatic management and potential disease modification. In this paper, we evaluate the utility of several dietary patterns, including the Mediterranean (MeDi), Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND), Alternative Healthy Eating Index (AHEI), vegan/vegetarian, and ketogenic diet in persons with PD. Additionally, we provide an overview of the evidence relating several individual food groups and nutritional supplements to PD risk, symptoms and progression.

Association Between Serum Homocysteine Concentration, Aneurysm Wall Inflammation, and Aneurysm Symptoms in Intracranial Fusiform Aneurysm

RATIONALE AND OBJECTIVES

The pathophysiology of fusiform intracranial aneurysm (FIA) involves inflammatory processes, and homocysteine plays a role in the inflammatory processes in the vessel wall. Moreover, aneurysm wall enhancement (AWE) has emerged as a new imaging biomarker of aneurysm wall inflammatory pathologies. To investigate the pathophysiological mechanisms of aneurysm wall inflammation and FIA instability, we aimed to determine the associations between the homocysteine concentration, AWE, and FIAs' related symptoms.

MATERIALS AND METHODS

We retrospectively reviewed the data of 53 patients with FIA who underwent both high-resolution magnetic resonance imaging and serum homocysteine concentration measurement. FIAs' related symptoms were defined as ischemic stroke or transient ischemic attack, cranial nerve compression, brainstem compression, and acute headache. The contrast ratio of the signal intensity of the aneurysm wall to the pituitary stalk (CRstalk) was used to indicate AWE. Multivariate logistic regression and receiver operating characteristic (ROC) curve analyses were performed to determine how well the independent factors could predict FIAs' related symptoms. Predictors of CRstalk were also investigated. Spearman's correlation coefficient was used to identify the potential associations between these predictors.

RESULTS

Fifty-three patients were included, of whom 23 (43.4%) presented with FIAs' related symptoms. After adjusting for baseline differences in the multivariate logistic regression analysis, the CRstalk (odds ratio [OR]=3.207, P = .023) and homocysteine concentration (OR=1.344, P = .015) independently predicted FIAs' related symptoms. The CRstalk was able to differentiate between FIAs with and without symptoms (area under the ROC curve [AUC]=0.805), with an optimal cutoff value of 0.76. The homocysteine concentration could also differentiate between FIAs with and without symptoms (AUC=0.788), with an optimal cutoff value of 13.13. The combination of the CRstalk and homocysteine concentration had a better ability to identify symptomatic FIAs (AUC=0.857). Male sex (OR=0.536, P = .018), FIAs' related symptoms (OR=1.292, P = .038), and homocysteine concentration (OR=1.254, P = .045) independently predicted the CRstalk.

CONCLUSION

A higher serum homocysteine concentration and greater AWE indicate FIA instability. Serum homocysteine concentration may be a useful biomarker of FIA instability; however, this needs to be verified in future studies.

Association analysis of MTHFR (rs1801133 and rs1801131) and MTRR (rs1801394) gene polymorphisms towards the development of hypertension in the Bai population from Yunnan, China

OBJECTIVE

Hypertension is one of the leading causes of human death and disability. MTHFR and MTRR regulate folate metabolism and are closely linked to hypertension, although the relationship is inconsistent among different ethnic groups. The present study aims to investigate the effects of MTHFR C677T (rs1801133), MTHFR A1298C (rs1801131), and MTRR A66G (rs1801394) polymorphisms on hypertension susceptibility in the Bai nationality of the Yunnan Province, China.

METHODS

This case-control study included 373 hypertensive patients and 240 healthy controls from the Chinese Bai population. The genotyping of MTHFR and MTRR gene polymorphisms was carried out by using the KASP method. The effects of genetic variations of MTHFR and MTRR genes on hypertension risk were evaluated with odds ratios (OR) and 95% confidence intervals (95% CI).

RESULTS

The present study revealed that the CT and TT genotypes and T allele of MTHFR C677T locus were considerably associated with an increased risk of hypertension. In addition, MTHFR A1298C locus CC genotype could significantly increase the hypertension risk. The T-A and C-C haplotypes of MTHFR C677T and MTHFR A1298C could increase the risk of hypertension. Further stratified analysis by risk rank of folate metabolism indicated that people with poor utilization of folic acid were more prone to develop hypertension. In the hypertension group, the MTHFR C677T polymorphism was significantly associated with fasting blood glucose, fructosamine, apolipoprotein A1, homocysteine, superoxide dismutase, and malondialdehyde levels.

CONCLUSION

Our study suggested that genetic variations of MTHFR C677T and MTHFR A1298C were significantly associated with susceptibility to hypertension in the Bai population from Yunnan, China.

Folate - a scoping review for Nordic Nutrition Recommendations 2023

Folate is an essential micronutrient for normal development and metabolic function, and folate deficiency is associated with an increased risk of cancer, cardiovascular disease, mental dysfuntion and negative pregnancy outcomes. When estimating folate requirements, one must consider different bioavailability and functionality between synthetic folic acid and dietary folate, together with increased needs of folate in women of fertile age, pregnant and lactating women, preterm and small for gestational age weight infants and individuals who are homozygote for the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene polymorphism. In order to achieve an adequate metabolic status based on the metabolic marker total homocysteine, and not merely the absence of clinical signs of folate deficiency, the recommended intake of folate differs according to age, pregnancy and lactation. According to the World Health Organization, a decision limit for folate deficiency in adults is serum folate level below 10 nmol/L, and in women of fertile age a red blood cell folate level below 906 nmol/L in order to prevent neural tube defects. Qualified systematic reviews along with identified relevant literature have been used for this scoping review prepared for the Nordic Nutrition Recommendations 2023.

Late-onset cobalamin C deficiency type in adult with cognitive and behavioral disturbances and significant cortical atrophy and cerebellar damage in the MRI: a case report

Background

Late-onset cobalamin C (cblC) deficiency is associated with a wide range of neurological and psychiatric symptoms, hematological manifestations, anorexia, renal failure, ocular abnormalities, dermatitis, and pancreatitis. However, the neuroimaging characteristics of late-onset cblC deficiency remain insufficiently documented. Common findings include diffuse white matter swelling, varying degrees of severe leukoaraiosis, hydrocephalus, corpus callosum atrophy, and symmetric bilateral basal ganglia lesions. In this report, we present a case of late-onset cblC deficiency in adults presenting with cerebellar ataxia as the primary symptom. The MRI findings revealed bilateral lateral cerebellar hemispheres exhibiting symmetric hyperintensity, primarily observed in diffusion-weighted imaging (DWI), which is a rarely reported imaging change in this context.

Case presentation

Our patient was a male who experienced symptoms starting at the age of 30 years, including unsteady walking, apparent cerebellar ataxia, and cognitive impairment upon nervous system examination. Brain magnetic resonance imaging (MRI) exhibited symmetric hyperintensity in the bilateral lateral cerebellar hemispheres, predominantly manifested in DWI, without any enhancement. Subsequently, significantly elevated blood total homocysteine and urinary methylmalonic acid levels were observed. Genetic analysis confirmed the presence of MMACHC compound heterozygous mutants c.482G > A and c.609G > A, thus confirming the diagnosis of cblC deficiency. These variants were classified as likely pathogenic following the guidelines of the American College of Medical Genetics and Genomics (ACMG) and were verified using Sanger sequencing. Following treatment, the patient experienced improvements in walking ability and cognition, a significant decrease in blood total homocysteine levels, and reversal of the imaging lesions.

In conclusion

Late-onset cblC deficiency presents with diverse clinical and imaging manifestations. Early diagnosis and treatment are crucial in achieving a favorable prognosis. This case serves as a reminder to clinicians not to overlook genetic metabolic disorders, particularly those causing multisite damage, in adult patients with undiagnosed neurological disorders, especially those affecting the cerebellum. Notably, methylmalonic acidemia should be considered within the spectrum of bilateral cerebellar lesions.

The effects of folinic acid and l-methylfolate supplementation on serum total homocysteine levels in healthy adults

BACKGROUND - AIM

Hyperhomocysteinemia is recognized as a risk factor for several diseases and conditions. The aim of this study was to investigate and compare the efficacy of two total homocysteine (tHcy)-lowering treatments including folinic acid or l-methylfolate in healthy Greek adults.

METHODS

Two hundred and seventy-two healthy Greek adults (143 men, 129 women; mean age±SD: 43.0 ± 15.3 years), with serum tHcy levels ≥10 μmol/L received randomized folinic acid ("Folinic acid Group") or l-methylfolate ("l-methylfolate Group") orally for three months. All subjects with serum cobalamin (Cbl) levels <300 pg/mL additionally received 1 mg hydroxycobalamine intramuscularly twice a week for the first month only. Serum folate, Cbl and tHcy levels were determined using immunoassays methods at the beginning and the end of the study period. The MTHFR C677T and MTHFR A1298C gene polymorphisms were genotyped using polymerase chain reaction and reverse hybridization.

RESULTS

At the end of the 3-month intervention period, the levels of serum folate and Cbl increased significantly, whereas the levels of serum tHcy decreased significantly in the two groups. The individuals with MTHFR 677TT genotype had a significantly higher reduction in serum tHcy levels than the individuals with the MTHFR 677CC or MTHFR 677CT genotypes. Although the "Folinic acid Group" had a considerably higher increase in their serum folate levels (but not Cbl) than the "l-methylfolate Group", the reduction of serum tHcy levels between the two groups was not substantially different. The individuals with MTHFR 677CT genotype had a statistically significant higher reduction in serum tHcy levels when supplemented with folinic acid rather than l-methylfolate.

CONCLUSIONS

The administration of folinic acid compared to l-methylfolate caused a higher increase of serum folate levels but no difference in the reduction of serum tHcy levels. The reduction of serum tHcy levels was influenced by the existence of MTHFR C677T and not MTHFR A1298C gene polymorphisms. The individuals with MTHFR 677CT genotype appear to benefit more by folinic acid than l-methylfolate supplementation.

Integrated analysis of the association between methionine cycle and risk of moyamoya disease

OBJECTIVE

The role of methionine (Met) cycle in the pathogenesis and progression of cardiovascular and cerebrovascular diseases has been established, but its association with moyamoya disease (MMD) has rarely been studied. This study aimed to analyze the levels of Met cycle-related metabolites and constructed a risk model to explore its association with the risk of MMD.

METHODS

In this prospective study, a total of 302 adult MMD patients and 88 age-matched healthy individuals were consecutively recruited. The serum levels of Met cycle-related metabolites were quantified by liquid chromatography-mass spectrometry (LC-MS). Participants were randomly divided into training set and testing set at a ratio of 1:1. The training set was used to construct the risk score model by LASSO regression. The association between Met cycle-related risk score and the risk of MMD was analyzed using logistic regression and assessed by ROC curves. The testing set was used for validation.

RESULTS

The levels of methionine sulfoxide and homocysteine were significantly increased, while the levels of betaine and choline were significantly decreased in MMD and its subtypes compared to healthy controls (p < 0.05 for all). The training set was used to construct the risk model and the risk score of each participant has been calculated. After adjusting for potential confounders, the risk score was independently associated with the risk of MMD and its subtypes (p < 0.05 for all). We then divided the participants into low-risk and high-risk groups, the high-risk score was significantly associated with the risk of MMD and its subtypes (p < 0.05 for all). The risk scores were further assessed as tertiles, the highest tertile was significantly associated with a higher risk of MMD and its subtypes compared to the lowest (p < 0.05 for all). The results were validated in the testing set.

CONCLUSION

This study has constructed and validated a risk model based on Met cycle-related metabolites, which was independently associated with the risk of MMD and its subtypes. The findings provided a new perspective on the risk evaluation and prevention of MMD.

Homocysteine metabolites inhibit autophagy, elevate amyloid beta, and induce neuropathy by impairing Phf8/H4K20me1-dependent epigenetic regulation of mTOR in cystathionine β-synthase-deficient mice

The loss of cystathionine β-synthase (CBS), an important homocysteine (Hcy)-metabolizing enzyme or the loss of PHF8, an important histone demethylase participating in epigenetic regulation, causes severe intellectual disability in humans. Similar neuropathies were also observed in Cbs-/- and Phf8-/- mice. How CBS or PHF8 depletion can cause neuropathy was unknown. To answer this question, we examined a possible interaction between PHF8 and CBS using Cbs-/- mouse and neuroblastoma cell models. We quantified gene expression by RT-qPCR and western blotting, mTOR-bound H4K20me1 by chromatin immunoprecipitation (CHIP) assay, and amyloid β (Aβ) by confocal fluorescence microscopy using anti-Aβ antibody. We found significantly reduced expression of Phf8, increased H4K20me1, increased mTOR expression and phosphorylation, and increased App, both on protein and mRNA levels in brains of Cbs-/- mice versus Cbs+/- sibling controls. Autophagy-related Becn1, Atg5, and Atg7 were downregulated while p62, Nfl, and Gfap were upregulated on protein and mRNA levels, suggesting reduced autophagy and increased neurodegeneration in Cbs-/- brains. In mouse neuroblastoma N2a or N2a-APPswe cells, treatments with Hcy-thiolactone, N-Hcy-protein or Hcy, or Cbs gene silencing by RNA interference significantly reduced Phf8 expression and increased total H4K20me1 as well as mTOR promoter-bound H4K20me1. This led to transcriptional mTOR upregulation, autophagy downregulation, and significantly increased APP and Aβ levels. The Phf8 gene silencing increased Aβ, but not APP, levels. Taken together, our findings identify Phf8 as a regulator of Aβ synthesis and suggest that neuropathy of Cbs deficiency is mediated by Hcy metabolites, which transcriptionally dysregulate the Phf8 → H4K20me1 → mTOR → autophagy pathway thereby increasing Aβ accumulation.