Homocysteine in Neurology: A Possible Contributing Factor to Small Vessel Disease

Correlation analysis and predictive model construction of metabolic syndrome, complete blood count-derived inflammatory markers, and overall burden of cerebral small vessel disease

Background

The high burden of cerebral small vessel disease (CSVD) on neuroimaging is a significant risk factor for stroke, cognitive dysfunction, and emotional disorders. Currently, there is a lack of studies investigating the correlation between metabolic syndrome (MetS), complete blood count-derived inflammatory markers, and total CSVD burden. This study aims to evaluate the total CSVD imaging load using machine learning (ML) algorithms and to explore further the relationship between MetS, complete blood count-derived inflammatory markers, and CSVD load.

Methods

We included CSVD patients from Xijing Hospital (2012-2022). Univariate and lasso regression analyses identified variables linked to CSVD neuroimaging burden. Six ML models predicted CSVD burden based on MetS and inflammatory markers. Model performance was evaluated using ROCauc, PRauc, DCA, and calibration curves. The SHAP method validated model interpretability. The best-performing model was selected to develop a web-based calculator using the Shiny package.

Results

The Logistic regression model outperformed others in predicting CSVD burden. The model incorporated MetS, neutrophil-to-lymphocyte ratio (NLR), homocysteine (Hcy), age, smoking status, cystatin C (CysC), uric acid (UA), and prognostic nutritional index (PNI).

Conclusion

MetS, NLR, Hcy and CSVD high load were positively correlated, and the Logistic regression model could accurately predict the total CSVD load degree.

Study on the metabolic effects of hexavalent chromium [Cr (VI)] on rat astrocytes using un-targeted metabolomics

Introduction: Hexavalent chromium [Cr (VI)] has been identified as a human carcinogen and environmental pollutant capable of affecting multiple systems in the human body. However, the specific mechanisms by which Cr (VI) affects the human nervous system remain unclear. Objective: Following confirmation of Cr (VI)'s toxic effects on rat astrocytes, this study explores the metabolites and associated metabolic pathways of rat astrocytes under different doses of Cr (VI) exposure. Methods: Cell viability was assessed using CCK8 assays, intracellular reactive oxygen species (ROS) levels were measured using DCFH-DA fluorescent probes, intracellular 8-hydroxydeoxyguanosine (8-OHdG) content was determined by Elisa, mitochondrial membrane potential was observed using JC-1 probes, and key metabolites were identified through untargeted metabolomics analysis. Results: With increasing Cr (VI) doses, significant decreases in cell viability were observed in the 4, 8, and 16 mg/L dose groups (p < 0.05). Elevated levels of ROS and 8-OHdG, increased caspase-3 activity, and significant reductions in mitochondrial membrane potential were observed in the 2 and 4 mg/L dose groups (p < 0.05). Untargeted metabolomics analysis revealed Cr (VI)'s impact on key metabolites such as sphingosine and methionine. Enrichment analysis of KEGG pathways highlighted the critical roles of sphingolipid metabolism and the methionine-cysteine cycle in the effects of Cr (VI) on rat astrocytes. Conclusion: Our study underscores the potential neuro-health risks associated with environmental and occupational exposure to Cr (VI) and provides new perspectives and directions for investigating neurotoxic mechanisms.

Unraveling the Hippocampal Molecular and Cellular Alterations behind Tramadol and Tapentadol Neurobehavioral Toxicity

Tramadol and tapentadol are chemically related opioids prescribed for the analgesia of moderate to severe pain. Although safer than classical opioids, they are associated with neurotoxicity and behavioral dysfunction, which arise as a concern, considering their central action and growing misuse and abuse. The hippocampal formation is known to participate in memory and learning processes and has been documented to contribute to opioid dependence. Accordingly, the present study assessed molecular and cellular alterations in the hippocampal formation of Wistar rats intraperitoneally administered with 50 mg/kg tramadol or tapentadol for eight alternate days. Alterations were found in serum hydrogen peroxide, cysteine, homocysteine, and dopamine concentrations upon exposure to one or both opioids, as well as in hippocampal 8-hydroxydeoxyguanosine and gene expression levels of a panel of neurotoxicity, neuroinflammation, and neuromodulation biomarkers, assessed through quantitative real-time polymerase chain reaction (qRT-PCR). Immunohistochemical analysis of hippocampal formation sections showed increased glial fibrillary acidic protein (GFAP) and decreased cluster of differentiation 11b (CD11b) protein expression, suggesting opioid-induced astrogliosis and microgliosis. Collectively, the results emphasize the hippocampal neuromodulator effects of tramadol and tapentadol, with potential behavioral implications, underlining the need to prescribe and use both opioids cautiously.

Study on the Correlation between Hcy and Hs-CRP Levels and Cognitive Function in Patients with Bipolar Disorder and Borderline Personality Disorder

OBJECTIVE

This study aims to explore the correlation and clinical significance of homocysteine and high-sensitivity C-reactive protein levels with cognitive function in patients with bipolar disorder (BD) and borderline personality disorder (BPD).

METHODS

Patients with BD admitted to our hospital from January 2022 to December 2022 were chosen retrospectively. BPD patients were categorized into comorbidity groups, while those without BPD were assigned to non-comorbidity groups, each consisting of 60 cases. Enzyme-linked immunosorbent assay (ELISA) was utilized to assess serum levels of homocysteine (Hcy) and high-sensitivity C-reactive protein (hs-CRP) in both patient groups. Clinical symptoms were evaluated by the Hamilton Depression Rating Scale (HAMD) and the Young Mania Rating Scale (YMRS). Cognitive function was evaluated and compared using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Pearson correlation analysis was performed on the correlation between patients' serum Hcy and hs-CRP levels and HAMD, YMRS, and RBANS scores.

RESULTS

In the comorbidity group, patients exhibited significantly elevated serum Hcy and hs-CRP levels compared to the non-comorbidity group (p < 0.05). Patients in the comorbidity group displayed higher HAMD and YMRS scores than those in the non-comorbidity group (p < 0.05). Additionally, attention, speech, visual span, immediate memory, and delayed memory in the comorbidity group were notably lower than in the non-comorbidity group (p < 0.05). The speech, visual span, and immediate memory of RBANS in bipolar depressive patients with comorbid BPD were lower than those in bipolar depressive patients without comorbid BPD (p < 0.05), the speech of RBANS in bipolar manic patients with comorbid BPD was lower than those in bipolar manic patients without comorbid BPD (p < 0.05). Pearson correlation analysis showed that the expression of Hcy and hs-CRP in the comorbid group was positively correlated with HAMD and YMRS scores, and negatively correlated with attention, speech, visual span, immediate memory, and delayed memory, and these differences were statistically significant (p < 0.05).

CONCLUSION

High serum Hcy and hs-CRP expression levels may regulate inflammatory responses, aggravating cognitive impairment in patients with BD and BPD. Serum Hcy and hs-CRP expression levels are significantly related to cognitive dysfunction. They are expected to guide the prevention and treatment of BD comorbid BPD patients.

The Metabolic Impact of Nonalcoholic Fatty Liver Disease on Cognitive Dysfunction: A Comprehensive Clinical and Pathophysiological Review

Nonalcoholic fatty liver disease (NAFLD) exponentially affects the global healthcare burden, and it is currently gaining increasing interest in relation to its potential impact on central nervous system (CNS) diseases, especially concerning cognitive deterioration and dementias. Overall, scientific research nowadays extends to different levels, exploring NAFLD's putative proinflammatory mechanism of such dysmetabolic conditions, spreading out from the liver to a multisystemic involvement. The aim of this review is to analyze the most recent scientific literature on cognitive involvement in NAFLD, as well as understand its underlying potential background processes, i.e., neuroinflammation, the role of microbiota in the brain-liver-gut axis, hyperammonemia neurotoxicity, insulin resistance, free fatty acids, and vitamins.

Molecular biomarkers for vascular cognitive impairment and dementia

As disease-specific interventions for dementia are being developed, the ability to identify the underlying pathology and dementia subtypes is increasingly important. Vascular cognitive impairment and dementia (VCID) is the second most common cause of dementia after Alzheimer disease, but progress in identifying molecular biomarkers for accurate diagnosis of VCID has been relatively limited. In this Review, we examine the roles of large and small vessel disease in VCID, considering the underlying pathophysiological processes that lead to vascular brain injury, including atherosclerosis, arteriolosclerosis, ischaemic injury, haemorrhage, hypoperfusion, endothelial dysfunction, blood-brain barrier breakdown, inflammation, oxidative stress, hypoxia, and neuronal and glial degeneration. We consider the key molecules in these processes, including proteins and peptides, metabolites, lipids and circulating RNA, and consider their potential as molecular biomarkers alone and in combination. We also discuss the challenges in translating the promise of these biomarkers into clinical application.

The Role of Methionine-Rich Diet in Unhealthy Cerebrovascular and Brain Aging: Mechanisms and Implications for Cognitive Impairment

As aging societies in the western world face a growing prevalence of vascular cognitive impairment and Alzheimer's disease (AD), understanding their underlying causes and associated risk factors becomes increasingly critical. A salient concern in the western dietary context is the high consumption of methionine-rich foods such as red meat. The present review delves into the impact of this methionine-heavy diet and the resultant hyperhomocysteinemia on accelerated cerebrovascular and brain aging, emphasizing their potential roles in cognitive impairment. Through a comprehensive exploration of existing evidence, a link between high methionine intake and hyperhomocysteinemia and oxidative stress, mitochondrial dysfunction, inflammation, and accelerated epigenetic aging is drawn. Moreover, the microvascular determinants of cognitive deterioration, including endothelial dysfunction, reduced cerebral blood flow, microvascular rarefaction, impaired neurovascular coupling, and blood-brain barrier (BBB) disruption, are explored. The mechanisms by which excessive methionine consumption and hyperhomocysteinemia might drive cerebromicrovascular and brain aging processes are elucidated. By presenting an intricate understanding of the relationships among methionine-rich diets, hyperhomocysteinemia, cerebrovascular and brain aging, and cognitive impairment, avenues for future research and potential therapeutic interventions are suggested.

Homocysteine levels in patients with coronary slow flow phenomenon: A meta-analysis

BACKGROUND

With the development of coronary angiography, more and more attention has been paid to coronary slow flow phenomenon (CSFP). Recent studies have found that the correlation between homocysteine (Hcy) levels and CSFP was contradictory, so we conducted this meta-analysis to investigate the correlation.

METHODS

By March 2022, studies that meet the research requirements were identified by searching multiple databases including Embase, Web of Science, and PubMed. We included studies evaluating the correlation between Hcy levels and CSFP. Random or fixed effect meta-analyses were performed according to heterogeneity among included studies. A leave-out method and subgroup analyses were conducted to determine the source of heterogeneity.

RESULTS

Thirteen studies involving 625 CSFP and 550 subjects were included. After pooling data from each study, Hcy levels were higher in the CSFP groups (standard mean difference [SMD], 1.45; 95% CI, 0.94 to 1.96, P < .00001) than in the control group. In the meta-analysis, there was significant heterogeneity (I2 = 93%), which was further explored through leave-out method and and subgroup analyses. Specifically, pooling data from studies with a mean thrombolysis in myocardial infarction (TIMI) frame count ≥ 46 (SMD, 1.31; 95% CI, 1.00 to 1.63, P < .00001) resulted in no heterogeneity (0%), indicating that the TIMI frame count ≥ 46 was the source of heterogeneity.

CONCLUSIONS

Our study found that elevated Hcy levels are strongly associated with CSFP. More importantly, the association was stronger in CSFP patients with mean TIMI frame count ≥ 46.

Association of serum homocysteine levels with intestinal flora and cognitive function in schizophrenia

Some studies have indicated that elevated homocysteine (Hcy) levels and intestinal flora may be involved in schizophrenia (SZ) cognition pathophysiology. This study was the first to investigate the association among Hcy, intestinal flora and schizophrenia cognition. Here, 140 individuals were divided into two groups: SZ patients (N = 68) and healthy controls (HCs, N = 72). Participant data on serum Hcy levels, intestinal flora and cognitive function evaluation using the MATRICS Consensus Cognitive Battery (MCCB) were collected. Clinical symptoms of patients were evaluated using the Positive and Negative Syndrome Scale. Serum Hcy levels and the incidence of hyperhomocysteinaemia were considerably increased in SZ patients compared with HCs. Hcy levels were significantly negatively associated with verbal learning index scores (r = -0.425, p < 0.001) but positively associated with Eubacterium (r = 0.32, p = 0.007), Lactobacillus (r = 0.32, p = 0.008), Corynebacterium (r = 0.26, p = 0.035), Mogibacterium (r = 0.31, p = 0.01), and Bulleidia (r = 0.31, p = 0.01) in SZ patients. Our findings suggest that serum Hcy levels are associated with cognitive function and intestinal flora in SZ patients. However, the mechanism of the interaction between Hcy and intestinal flora and its effects on cognitive function in SZ patients requires further investigation.

Exploratory analysis of the effect of a controlled lifestyle intervention on inflammatory markers - the Healthy Lifestyle Community Programme (cohort 2)

BACKGROUND

Chronic low-grade inflammation is associated with an increased risk of chronic disease and mortality. The objective of the study was to test the effect of a healthy lifestyle intervention on biomarkers of inflammation (among other risk markers).

METHODS

We conducted a non-randomized controlled trial with mostly middle-aged and elderly participants from the general population in rural northwest Germany (intervention: n = 114; control: n = 87). The intervention consisted of a 1-year lifestyle programme focusing on diet (largely plant-based; strongest emphasis), physical activity, stress management, and social support. High-sensitivity C-reactive protein (hs-CRP) was assessed at baseline, 10 weeks, 6 months, and 1 year. Homocysteine (Hcy) was assessed at baseline, 10 weeks, and 1 year. Adiponectin (Apn) was assessed at baseline and 10 weeks. An exploratory analysis of these inflammatory markers assessing the between-group differences with ANCOVA was conducted.

RESULTS

The 1-year trajectory of hs-CRP was significantly lower in the intervention group compared to control (between-group difference: -0.8 (95% CI -1.2, -0.3) mg/l; p = 0.001; adjusted for baseline). The 1-year trajectory of Hcy was non-significantly higher in the intervention compared to control (between-group difference: 0.2 (95% CI -0.3, 0.7) µmol/l; p = 0.439; adjusted for baseline). From baseline to 10 weeks, Apn decreased significantly more in the intervention group compared to control (between-group difference: -1.6 (95% CI -2.7, -0.5) µg/ml; p = 0.004; adjusted for baseline).

CONCLUSIONS

Our study shows that healthy lifestyle changes can lower hs-CRP and Apn levels and are unlikely to significantly affect Hcy levels within 1 year.

TRIAL REGISTRATION

German Clinical Trials Register (DRKS; reference: DRKS00018775 , registered 12 Sept 2019; retrospectively registered; www.drks.de ).

Metabolic Reprogramming of Microglia in Sepsis-Associated Encephalopathy: Insights from Neuroinflammation

Sepsis-associated encephalopathy (SAE) is a diffuse brain dysfunction caused by sepsis that manifests as a range of brain dysfunctions from delirium to coma. It is a relatively common complication of sepsis associated with poor patient prognosis and mortality. The pathogenesis of SAE involves neuroinflammatory responses, neurotransmitter dysfunction, blood-brain barrier (BBB) disruption, abnormal blood flow regulation, etc. Neuroinflammation caused by hyperactivation of microglia is considered to be a key factor in disease development, which can cause a series of chain reactions, including BBB disruption and oxidative stress. Metabolic reprogramming has been found to play a central role in microglial activation and executive functions. In this review, we describe the pivotal role of energy metabolism in microglial activation and functional execution and demonstrate that the regulation of microglial metabolic reprogramming might be crucial in the development of clinical therapeutics for neuroinflammatory diseases like SAE.

Gender difference in association between H-type hypertension and subcortical ischemic vascular disease

Background

Subcortical ischemic vascular disease (SIVD) is a leading cause of vascular dementia. The present study tries to explore not only the gender-specific association between H-type hypertension and SIVD but also the indirect effects of H-type hypertension on cognition through the ischemic brain injury caused by SIVD.

Materials and methods

A total of 601 SIVD patients were included, comprising 322 males and 279 females. H-type hypertension was defined as hypertension accompanied with elevated serum total homocysteine (tHcy) level. The imaging manifestations of ischemic brain injury caused by SIVD were also evaluated, including white matter lesions (WML), lacunar infarction (LI) and brain atrophy (BA). Gender-specific subgroup analyses in association between H-type hypertension and SIVD were conducted, followed by a structural equation model based evaluation of the gender-specific mediating effects of SIVD on the relationship between H-type hypertension and cognition.

Results

For males, there was no noticeable difference in WML, LI and BA scores among control group, isolated hypertension group, isolated high tHcy group, and H-type hypertension group in most brain regions, but significant difference was found in all brain regions for females. Multiple regression analyses showed that H-type hypertension was significantly associated with WML, LI and BA for females, but not for males. For males, H-type hypertension mainly affected cognition through direct effect, while the H-type hypertension effect was mediated by ischemic brain injury caused by SIVD for females.

Conclusion

H-type hypertension was more closely related to SIVD for females than males, suggesting a gender-specific difference in association patterns between H-type hypertension and cognition.

Pathogenesis and research progress in leukoaraiosis

Leukoaraiosis is a common imaging marker of cerebral small vessel disease. In recent years, with the continuous advances in brain imaging technology, the detection rate of leukoaraiosis is higher and its clinical subtypes are gradually gaining attention. Although leukoaraiosis has long been considered an incidental finding with no therapeutic necessity, there is now growing evidence linking it to, among other things, cognitive impairment and a high risk of death after stroke. Due to different research methods, some of the findings are inconsistent and even contradictory. Therefore, a comprehensive and in-depth study of risk factors for leukoaraiosis is of great clinical significance. In this review, we summarize the literature on leukoaraiosis in recent years with the aim of elucidating the disease in terms of various aspects (including pathogenesis, imaging features, and clinical features, etc.).

Homocysteine is related to enlarged perivascular spaces in the brainstem in patients with isolated pontine infarction

Background

Homocysteine is correlated with several imaging features of cerebral small vessel disease including white matter hyperintensities, lacunes, and enlarged perivascular spaces (EPVS) in the basal ganglia. However, little is known about EPVS in the brainstem. This study aimed to investigate the correlation between serum total homocysteine (tHcy) and EPVS in the brainstem in patients with acute isolated pontine infarction.

Methods

Consecutive patients with isolated pontine infarction were retrospectively enrolled. Clinical characteristics and laboratory tests including tHcy were recorded. Imaging markers of cerebral small vessel disease including EPVS in the basal ganglia (BG-EPVS), EPVS in the centrum semiovale, and EPVS in the midbrain or pons (brainstem-EPVS) were assessed using conventional magnetic resonance imaging. The relation between tHcy and EPVS of different parts in the brain was analyzed using univariate and multivariate regression model.

Results

A total of 227 patients were included (mean age 67.10 ± 9.38 years, male sex 58.6%). The frequencies of brainstem-EPVS and moderate to severe BG-EPVS accounted for 40.1% (91/227) and 40.5% (92/227) respectively. After controlling for confounding factors, multivariate logistic regression analyses showed that tHcy was an independent risk factor for both moderate to severe BG-EPVS (P = 0.003, P for trend < 0.001) and the presence of brainstem-EPVS (P < 0.001, P for trend < 0.001) in a dose-dependent manner. Furthermore, multivariate linear regression model indicated that the presence of brainstem-EPVS (β = 0.264, 95% confidence interval = 0.143-0.402, P < 0.001) and the severity of BG-EPVS (β = 0.162, 95% confidence interval = 0.024-0.197, P = 0.013) were positively associated with serum tHcy.

Conclusions

Serum tHcy is correlated with brainstem-EPVS and BG-EPVS dose-dependently. This study may support a contributing role for homocysteine in the pathophysiology of EPVS in the brainstem and the basal ganglia.

The Effect of 3-Week Betaine Supplementation on Blood Biomarkers of Cardiometabolic Health in Young Physically Active Males

Betaine (BET) supplementation decreases homocysteine concentration in plasma, but it may also have an adverse effect on health by increasing blood lipid concentrations, at least in overweight and obese individuals. The aim of this study was to evaluate the effect of BET supplementation on the lipid profile and concentrations of homocysteine, inflammatory cytokines, and liver enzymes in physically active, healthy males. This was a randomized, placebo (PL)-controlled, double-blinded, crossover trial. BET (2.5 or 5.0 g/d) was administered for 21 days. Before and after supplementation with BET or PL, anthropometric measurements and blood were collected in a fasted state. Our results show that BET supplementation significantly decreased homocysteine concentration (from 17.1 ± 4.0 μmol/L before BET to 15.6 ± 3.5 μmol/L after BET, p = 0.009, η² = 0.164). However, the intervention had no effect on total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triacylglycerol, interleukins 1β and 6, and tumour necrosis factor α concentrations, or alanine and aspartate activities. In addition, there were no interactions between the MTHFR genotype and BET dose. In conclusion, BET supplementation may be beneficial for homocysteine concentration in healthy, physically active males, with no detrimental effect on lipid profile.

Cerebral small vessel disease mediates the association between homocysteine and cognitive function

Objective

To investigate the relations of serum total homocysteine (tHcy) with cerebral small vessel disease (CSVD) and cognitive function and evaluate whether CSVD mediates the effect of serum tHcy on cognitive function.

Methods

A total of 1,033 consecutive eligible participants who received serum tHcy, brain magnetic resonance imaging (MRI), and neuropsychological assessment were included in this retrospective study. White matter hyperintensity, lacune, cerebral microbleed, and enlarged perivascular space were evaluated based on brain MRI. We used multivariate binary logistic regression analysis, multivariate ordinal logistic regression analysis, and mediation analyses to assess the relations of serum tHcy with CSVD and cognitive function.

Results

Serum tHcy levels were higher in patients with cognitive impairment than those with no cognitive impairment. Logistic regression analyses showed elevated serum tHcy was associated with cognitive impairment [odds ratio (OR): 10.475; 95% confidence interval (CI): 4.522 to 24.264; p < 0.001] and a higher CSVD burden score (OR: 17.151; 95% CI: 8.785 to 33.921; p < 0.001) after adjusting potential confounders. Compared with the lowest tHcy quartile, the multivariable-adjusted OR of the highest quartile was 4.851 (95% CI: 3.152 to 7.466; p for the trend < 0.001) for cognitive impairment, 3.862 (95% CI: 2.467 to 6.047; p for the trend < 0.001) for a severe CSVD burden score. Mediation analyses showed significant moderating effects (9.3–23.6%) by different imaging markers of CSVD on the association between higher serum tHcy levels and cognitive impairment.

Conclusion

Elevated serum tHcy is associated with cognitive impairment and the development of CSVD. A proportion of the association between elevated serum tHcy and cognitive impairment may be attributed to the presence of different imaging markers of CSVD, especially the severe CSVD burden score.

Nonalcoholic Fatty Liver Disease and Altered Neuropsychological Functions in Patients with Subcortical Vascular Dementia

NAFLD is the most common cause of abnormality in liver function tests. NAFLD is considered a potential cardiovascular risk factor and is linked to cardiovascular risk factors such as obesity, hypertension, type 2 diabetes, and dyslipidemia. Few previous studies have investigated whether NAFLD could be independently associated with cognitive impairment. The current study aims to find a possible role of NAFLD in the development of subcortical vascular dementia (sVaD). We considered NAFLD as a possible independent vascular risk factor or, considering its metabolic role, associated with other commonly accepted sVaD risk factors, i.e., lack of folate, vitamin B12, and vitamin D-OH25, and increased levels of homocysteine. We studied 319 patients diagnosed with sVaD. All patients underwent an abdominal ultrasound examination to classify steatosis into four levels (1-none up to 4-severe). sVaD patients were divided into two groups according to the presence or absence of NAFLD. Our results demonstrated a strong correlation between NAFLD and sVaD. Patients with the two comorbidities had worse neuropsychological outcomes and a worse metabolic profile. We also found a robust relationship between NAFLD and severe vitamin B12, folate, vitamin D hypovitaminosis, and higher hyperhomocysteinemia levels. This way, it is evident that NAFLD contributes to a more severe metabolic pathway. However, the strong relationship with the three parameters (B12, folate and vitamin D, and homocysteinemia) suggests that NAFLD can contribute to a proinflammatory condition.

URB597 and Andrographolide Improve Brain Microvascular Endothelial Cell Permeability and Apoptosis by Reducing Oxidative Stress and Inflammation Associated with Activation of Nrf2 Signaling in Oxygen-Glucose Deprivation

Ischemic stroke, a cerebrovascular disease worldwide, triggers a cascade of pathophysiological events, including blood-brain barrier (BBB) breakdown. Brain microvascular endothelial cells (BMECs) play a vital role in maintaining BBB function. The injury of BMECs may worsen neurovascular dysfunction and patients' prognosis. Therefore, uncover the principal molecular mechanisms involved in BBB disruption in stroke becomes pressing. The endocannabinoid system (ECS) has been implicated in increasingly physiological functions, both in neurometabolism and cerebrovascular regulation. Modulating its activities by the fatty acid amide hydrolase (FAAH) shows anti-inflammatory characteristics. Andrographolide (AG), one Chinese herbal ingredient, has also attracted attention for its role in immunomodulatory and as a therapeutic target in BBB disorders. Recently, the FAAH inhibitor URB597 and AG have important regulatory effects on neuronal and vascular cells in ischemia. However, the effects of URB597 and AG on BMEC permeability and apoptosis in oxygen-glucose deprivation (OGD) and the underlying mechanisms remain unclear. To address these issues, cultured BMECs (bEnd.3 cells) were exposed to OGD. The cell viability, permeability, tube formation, and apoptosis were assessed following treatment with URB597, AG, and cotreatment. Mitochondrial membrane potential (MMP), reactive oxygen species (ROS), superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), proinflammatory factors, tight junction (TJ) proteins, and oxidative stress-mediated Nrf2 signaling were also investigated. Results revealed that OGD broke the endothelial barrier, cell viability, MMP, and tube formation, which was reversed by URB597 and AG. OGD-induced enhancement of ROS, MDA, and apoptosis was reduced after drug interventions. URB597 and AG exhibited antioxidant/anti-inflammatory and mitochondrial protective effects by activating Nrf2 signaling. These findings indicated that URB597 and AG protect BMECs against OGD-induced endothelial permeability impairment and apoptosis by reducing mitochondrial oxidative stress and inflammation associated with activation of Nrf2 signaling. URB597 and AG showing the vascular protection may have therapeutic potential for the BBB damage in ischemic cerebrovascular diseases.

Protein S-sulfhydration: Unraveling the prospective of hydrogen sulfide in the brain, vasculature and neurological manifestations

Hydrogen sulfide (H₂S) and hydrogen polysulfides (H₂S_n) are essential regulatory signaling molecules generated by the entire body, including the central nervous system. Researchers have focused on the classical H₂S signaling from the past several decades, whereas the last decade has shown the emergence of H₂S-induced protein S-sulfhydration signaling as a potential therapeutic approach. Cysteine S-persulfidation is a critical paradigm of post-translational modification in the process of H₂S signaling. Additionally, studies have shown the cross-relationship between S-sulfhydration and other cysteine-induced post-translational modifications, namely nitrosylation and carbonylation. In the central nervous system, S-sulfhydration is involved in the cytoprotection through various signaling pathways, viz. inflammatory response, oxidative stress, endoplasmic reticulum stress, atherosclerosis, thrombosis, and angiogenesis. Further, studies have demonstrated H₂S-induced S-sulfhydration in regulating different biological processes, such as mitochondrial integrity, calcium homeostasis, blood-brain permeability, cerebral blood flow, and long-term potentiation. Thus, protein S-sulfhydration becomes a crucial regulatory molecule in cerebrovascular and neurodegenerative diseases. Herein, we first described the generation of intracellular H₂S followed by the application of H₂S in the regulation of cerebral blood flow and blood-brain permeability. Further, we described the involvement of S-sulfhydration in different biological and cellular functions, such as inflammatory response, mitochondrial integrity, calcium imbalance, and oxidative stress. Moreover, we highlighted the importance of S-sulfhydration in cerebrovascular and neurodegenerative diseases.

Association between Homocysteine, Frailty and Biomechanical Response of the CNS in NPH-suspected Patients

Frailty is a geriatric syndrome that combines physiological decline, disruptions of homeostatic mechanisms across multiple physiologic systems and thus, strong vulnerability to further pathological stress. Previously, we provided the first evidence that increased risk of poor health outcomes, as quantified by a frailty index, is associated with an alteration of the central nervous system (CNS) biomechanical response to blood pulsatility. In this study, we explored correlation between fourteen biological parameters, the CNS elastance coefficient and frailty index. We included 60 adults (52-92 years) suspected of normal pressure hydrocephalus (NPH) and presenting with markers of multiple co-existing brain pathologies, including Parkinson disease (PD), Alzheimer disease (AD) and vascular dementia. We showed that the homocysteine (Hcy) level was independently and positively associated with both frailty index and the CNS elastance coefficient (adjusted R² of 10% and 6%). We also demonstrated that creatinine clearance and folate level were independently associated with Hcy level. Based on previous literature results describing the involvement of Hcy in endothelial dysfunction, glial activation and neurodegeneration, we discuss how Hcy could contribute to the altered biomechanical response of the CNS and frailty.

Small Vessel Disease: Ancient Description, Novel Biomarkers

Small vessel disease (SVD) is one of the most frequent pathological conditions which lead to dementia. Biochemical and neuroimaging might help correctly identify the clinical diagnosis of this relevant brain disease. The microvascular alterations which underlie SVD have common origins, similar cognitive outcomes, and common vascular risk factors. Nevertheless, the arteriolosclerosis process, which underlines SVD development, is based on different mechanisms, not all completely understood, which start from a chronic hypoperfusion state and pass through a chronic brain inflammatory condition, inducing a significant endothelium activation and a consequent tissue remodeling action. In a recent review, we focused on the pathophysiology of SVD, which is complex, involving genetic conditions and different co-morbidities (i.e., diabetes, chronic hypoxia condition, and obesity). Currently, many points still remain unclear and discordant. In this paper, we wanted to focus on new biomarkers, which can be the expression of the endothelial dysfunction, or of the oxidative damage, which could be employed as markers of disease progression or for future targets of therapies. Therefore, we described the altered response to the endothelium-derived nitric oxide-vasodilators (ENOV), prostacyclin, C-reactive proteins, and endothelium-derived hyperpolarizing factors (EDHF). At the same time, due to the concomitant endothelial activation and chronic neuroinflammatory status, we described hypoxia-endothelial-related markers, such as HIF 1 alpha, VEGFR2, and neuroglobin, and MMPs. We also described blood–brain barrier disruption biomarkers and imaging techniques, which can also describe perivascular spaces enlargement and dysfunction. More studies should be necessary, in order to implement these results and give them a clinical benefit.

Hyperhomocysteinemia Increases Risk of Metabolic Syndrome and Cardiovascular Death in an Elderly Chinese Community Population of a 7-Year Follow-Up Study

Background

Hyperhomocysteinemia (HHcy) and abdominal obesity are risk factors for metabolic syndrome (MetS) and death from cardiovascular disease (CVD). Recent studies have shown a correlation between HHcy and abdominal obesity, suggesting that they may have a combined effect on the risk of MetS and CVD mortality. However, this suspicion remains to be confirmed, particularly in the elderly population. We explored their combined effects on the risk of MetS and CVD mortality among the community population aged 65 and above in China.

Methods and Results

This prospective study enrolled 3,675 Chinese community residents aged 65 and above in May 2013 with 7-year follow-up of all-cause and CVD mortality. HHcy was defined as the blood homocysteine (Hcy) level >15 μmol/L and abdominal obesity as waist circumference (WC) ≥90 cm for men and ≥80 cm for women (HWC). All participants were grouped into four categories by WC and the blood level of Hcy: NWC (normal WC) /HHcy(–), NWC/HHcy(+), HWC/HHcy(–), and HWC/HHcy(+). The relationship of combined HHcy and abdominal obesity with MetS and metabolic profile was evaluated by logistic regression analysis and the association of combined HHcy and abdominal obesity with CVD and all-cause mortality evaluated by Cox regression analysis. The prevalence of HHcy, abdominal obesity and MetS in elderly Chinese community residents was 40.1, 59.3, and 41.4%, respectively. Using group without HHcy and abdominal obesity [NWC/HHcy(–)] as reference, the participants of other three groups had significantly higher risk of MetS and its component abnormalities, with HWC/HHcy(+) group having the highest risk (OR = 13.52; 95% CI = 8.61–14.55). After a median of 6.94 (±1.48) years follow-up, 454 deaths occurred with 135 CVD deaths. Compared with NWC/HHcy(–) group, the risk of 7-year follow-up CVD mortality (HR = 1.75; 95% CI = 1.02–3.03) and all-cause mortality (HR = 1.23; 95% CI = 1.04–2.18) of HWC/HHcy(+) group increased considerably after adjustment for major MetS and CVD risk factors.

Conclusions

There is high prevalence of HHcy, abdominal obesity, and MetS in the elderly Chinese community population. HHcy increases risk of MetS, CVD, and all-cause mortality, especially in the populations with abdominal obesity.

Precision medicine in secondary prevention of ischemic stroke: how may blood-based biomarkers help in clinical routine? An expert opinion

PURPOSE OF REVIEW

One in eight patients unfortunately suffers a new stroke within 5 years of their first stroke, even today. Research in precision medicine could lead to a more individualized treatment allocation, possibly achieving lower recurrence rates of ischemic stroke. In this narrative review, we aim to discuss potential clinical implementation of several promising candidate blood biomarkers.

RECENT FINDINGS

We discuss specifically some promising blood-based biomarkers, which may improve the identification of underlying causes as well as risk stratification of patients according to their specific cerebrovascular risk factor pattern.

SUMMARY

Multimodal profiling of ischemic stroke patients by means of blood biomarkers, in addition to established clinical and neuroradiological data, may allow in the future a refinement of decision algorithms for treatment allocation in secondary ischemic stroke prevention.

Sitagliptin Attenuates the Cognitive Deficits in L-Methionine-Induced Vascular Dementia in Rats

Vascular dementia (VaD) is the second most prevalent type of dementia characterized by progressive cognitive deficits and is a major risk factor for the development of Alzheimer's disease and other neurodegenerative disorders. This study is aimed at determining the potential neuroprotective effect of sitagliptin (STG) on cognitive deficits in L-methionine-induced VaD in rats and the possible underlying mechanisms. 30 adult male Wistar albino rats were divided equally (n = 10) into three groups: control, VaD, and VaD + STG groups. The cognitive performance of the animals was conducted by open field, elevated plus maze, Y-maze, novel object recognition, and Morris water maze tests. Serum homocysteine, TNF-α, IL-6, IL-10, total cholesterol, and triglycerides levels were assessed together with hippocampal MDA, SOD, and BDNF. Histopathological and immunohistochemical assessments of the thoracic aorta and hippocampus (CA1 region) were also performed. Chronic L-methionine administration impaired memory and learning and induced anxiety. On the other hand, STG protected against cognitive deficits through improving oxidative stress biomarkers, inflammatory mediators, lipid profiles, and hippocampus level of BDNF as well as decreasing caspase-3 and GFAP and increasing Ki-67 immunoreactions in the hippocampus. Also, STG improved the endothelial dysfunction via upregulation of aortic eNOS immunoreaction. STG improved the cognitive deficits of L-methionine-induced VaD by its antioxidant, anti-inflammatory, antiapoptotic, and neurotrophic effects. These findings suggest that STG may be a promising future agent for protection against VaD.

The Correlations Between Serum Hcy Level and Seizures and Cognitive Function in Patients After Stroke

BACKGROUNDS

Post-stroke cognitive dysfunction (PSCI), a set of illnesses ranging from moderate cognitive impairment to dementia, which is one of the most prevalent consequences following a stroke. Homocysteine (Hcy) has been related to a number of neurological and systemic diseases. It's also a known risk factor for cardiovascular disease and systemic atherosclerosis (CVD). The link between Hcy and PSCI, on the other hand, is unknown.

METHODS

Our hospital evaluated 325 patients with acute cerebral infarction between January 1, 2018 and December 1, 2021. There are biological markers and baseline data available. Patients were divided into two groups based on the results of the Montreal Cognitive Assessment (MoCA). The researchers performed logistic regression analysis to find variables that may be linked to PSCI.

RESULTS

HCY levels were significantly higher in PSCI patients than in non-PSCI patients. Age, education, seizure manifestation, and income level were all shown to be independent risk variables for PSCI in a multivariate logistic analysis. Hcy levels in PSCI patients differed considerably between the high and low groups. The high and low Hcy levels groups had significantly varied hypertension histories and urine levels. Hcy levels in PSCI patients differed considerably between the high and low groups. The high and low Hcy levels groups had significantly varied hypertension histories and urine levels.

CONCLUSION

Serum Hcy levels have been linked to PSCI in post-stroke patients, and researchers believe that serum Hcy levels will diminish PSCI.

Folic Acid Treatment for Patients with Vascular Cognitive Impairment: A Systematic Review and Meta-Analysis

BACKGROUND

As the life expectancy of elderly people has drastically increased, the incidence of cardiovascular and cerebrovascular diseases in this population has proportionally grown. Vascular cognitive impairment (VCI) refers to all forms of cognitive disorder associated with cerebrovascular disease. Homocysteine has recently been recognized as a contributor to the pathomechanisms involved in cognitive impairment. B vitamins, such as folic acid, are known to be effective in lowering homocysteine levels.

AIM OF THE STUDY

To evaluate the efficacy of folic acid in patients with VCI.

METHODS

We conducted a systematic review and meta-analysis of research on folic acid treatments for VCI. Only randomized controlled trials studies that compared the efficacy of folic acid to placebo or other interventions were considered, irrespective of publication status, year of publication, and languages. Two independent reviewers searched the Medline via Ovid, EMBASE and Cochrane Central Register of Controlled Trials (Central) journal databases up to July 2021 and independently appraised the included studies. We used mean difference outcome with 95% confidence intervals (CI) to calculate the change of Mini-Mental State Examination (MMSE), cognitive function domain, and concentration of homocysteine.

RESULTS

We found three studies comparing folic acid with placebo and one study comparing folic acid with other interventions. There is only slight evidence that the MMSE score in patients who received Folic Acid increased 0.3 point higher compared to the placebo group after 24 months (95% CI:-0.12-0.37; p=0.31). There is very strong evidence that the concentration of Homocysteine in the Folic Acid group became 6.16 μmol/L lower compared to the placebo group after 6 months (95% CI:2.32-8.21 lower; p<0.001).

CONCLUSIONS

Our review shows the effectiveness of folic acid in lowering plasma homocysteine concentration after 6 months period compared to placebo. However, this effect is not accompanied by improvement in cognitive function.

Emerging role of white matter lesions in cerebrovascular disease

White matter lesions have been implicated in the setting of stroke, dementia, intracerebral haemorrhage, several other cerebrovascular conditions, migraine, various neuroimmunological diseases like multiple sclerosis, disorders of metabolism, mitochondrial diseases and others. While much is understood vis a vis neuroimmunological conditions, our knowledge of the pathophysiology of these lesions, and their role in, and implications to, management of cerebrovascular diseases or stroke, especially in the elderly, are limited. Several clinical assessment tools are available for delineating white matter lesions in clinical practice. However, their incorporation into clinical decision-making and specifically prognosis and management of patients is suboptimal for use in standards of care. This article sought to provide an overview of the current knowledge and recent advances on pathophysiology, as well as clinical and radiological assessment, of white matter lesions with a focus on its development, progression and clinical implications in cerebrovascular diseases. Key indications for clinical practice and recommendations on future areas of research are also discussed. Finally, a conceptual proposal on putative mechanisms underlying pathogenesis of white matter lesions in cerebrovascular disease has been presented. Understanding of pathophysiology of white matter lesions and how they mediate outcomes is important to develop therapeutic strategies.