The Role of Asymmetric Dimethylarginine (ADMA) in Endothelial Dysfunction and Cardiovascular Disease

L-Arginine and Nitric Oxide in Vascular Regulation-Experimental Findings in the Context of Blood Donation

This narrative review provides an analysis of the role of nitric oxide (NO) and its precursors, particularly L-arginine, in vascular regulation and health, with an emphasis on findings from our experimental research in animal models. NO serves as a critical mediator of vascular function, contributing to vasodilation, the regulation of blood flow, and the prevention of thrombosis. As a primary precursor of NO, L-arginine is essential for maintaining endothelial integrity, modulating mitochondrial function, and reducing oxidative damage. This review synthesises the data and contextualises these findings within the physiological challenges faced by blood donors, such as repeated blood donation and associated oxidative stress. It examines the effects of L-arginine supplementation on mitochondrial respiration, lipid peroxidation, and microsomal oxidation in different conditions, including differences in age, gender, and dietary interventions. The mechanisms by which L-arginine enhances NO production, improves vascular elasticity, and alleviates endothelial dysfunction caused by reduced NO bioavailability are also investigated. By integrating experimental findings with insights from the existing literature, this review provides a perspective on the potential of L-arginine supplementation to address the specific physiological needs of blood donors. It highlights the importance of personalised nutritional approaches in enhancing donor recovery and vascular resilience. In addition, this review assesses the wider implications of L-arginine supplementation in mitigating oxidative stress and preserving vascular function. The interplay between NO bioavailability, dietary factors, and physiological adaptation in blood donors is highlighted, along with the identification of current knowledge gaps and recommendations for future research. By presenting both original experimental evidence and a critical synthesis of the literature, this article highlights the therapeutic potential of NO precursors, particularly L-arginine, in promoting vascular health in the context of blood donation.

Mechanisms of Homoarginine: Looking Beyond Clinical Outcomes

PURPOSE

Homoarginine (hArg) is an arginine metabolite that has been known for years, but its physiological role in the body remains poorly understood. For instance, it is well known that high hArg concentrations in the blood are protective against several disease states, yet the mechanisms behind these health benefits are unclear. This review compiles what is known about hArg, namely its synthetic pathways, its role in different diseases and conditions, and its proposed mechanisms of action in humans and experimental animals.

FINDINGS

Previous work has identified multiple pathways that control hArg synthesis and degradation in the body. Furthermore, endogenous hArg can modulate the cardiovascular system, with decreased hArg being associated with cardiovascular complications and increased mortality. Studies also suggest that hArg could serve as a diagnostic biomarker for a variety of immune, pancreatic, renal, and hepatic dysfunctions. Finally, in women, hArg concentrations rapidly increase throughout pregnancy and there are suggestions that alterations in hArg could indicate pregnancy complications like pre-eclampsia.

SUMMARY

Homoarginine is an under-appreciated amino acid with potential wide-ranging roles in systemic health, pregnancy, and pathophysiology. Although recent research has focused on its health or disease associations, there is a need for more investigations into understanding the mechanistic pathways by which hArg may operate. This could be aided using metabolomics, which provides a comprehensive approach to correlating multiple metabolites and metabolic pathways with physiological effects. Increasing our knowledge of hArg's roles in the body could pave the way for its routine use as both a diagnostic and therapeutic molecule.

Regulation of nitric oxide generation and consumption

Nitric oxide (NO), originally discovered for its role in cardiovascular function, is a key molecule in physiological processes including metabolism, neurotransmission (including memory, learning, neuroprotection and synaptic plasticity), immunity, reproduction, and much more. NO can be synthesized by the catalytic activity of the enzyme nitric oxide synthase (NOS), which is found biologically in three isoforms, or nonenzymatically based on simple reduction of nitrate and nitrite or by the NO-donor S-nitrosothiol (R-SNO). Importantly, the deficiency of NO has been noted in a wide range of pathologies including cardiovascular disease, cancer, erectile dysfunction, male and female infertility, and mitochondrial disease. While there are several pathways that can lead to a reduction in the bioavailability of NO (i.e., consumption, inhibition, and substrate competition) it is the conclusion of the authors that multiple pathways co-exist in pathological states. This article outlines for the first time the major pathways of NO generation, the importance of NO in health, NO scavenging and enzyme inhibition, and the potential benefits of supplementation.

Assessing the Role of Asymmetric Dimethylarginine in Endothelial Dysfunction: Insights Into Cardiovascular Risk Factors

BACKGROUND AND OBJECTIVE

Asymmetric dimethylarginine (ADMA) exacerbates endothelial dysfunction, which increases the risk of kidney and cardiovascular problems. This study aimed to investigate the association of ADMA levels in patients with type 2 diabetes mellitus (T2DM), including diabetic heart disease and diabetic kidney disease (DKD).

MATERIALS AND METHODS

This was a cross-sectional study conducted in a tertiary hospital, including 136 participants, categorizing them into four groups aged between 18-65 years: normal healthy controls (n=30), diabetes mellitus (DM) group with T2DM patients (n=39), diabetics with coronary artery disease (DCAD) group with T2DM patients with coronary artery disease (CAD) (n=34), and DKD group with T2DM patients with deranged kidney function (n=33). Comprehensive clinical and laboratory assessments were conducted, including ADMA levels quantified via enzyme-linked immunosorbent assay (ELISA) kits.  Results: In the study with 136 participants, 91 were male (66.9%), and averaging 55 years old, hypertension was prevalent in 34 participants (32.1%), more in the DKD group. Exercise adherence was low, especially among diabetic patients, but slightly better in those with complications. Among diabetics, 71 participants (67%) had uncontrolled blood sugar (glycosylated hemoglobin (HbA1c) > 7.0). Dyslipidemia was common in the DCAD group. The DKD group showed significantly low hemoglobin and proteinuria levels. The ADMA levels were significantly raised in diabetes and were maximum in the DCAD group, hence promising for predicting CAD, correlating with HbA1c and dyslipidemia.

CONCLUSION

In summary, our findings underscore the heightened cardiovascular vulnerability in diabetes, particularly in the presence of CAD and deranged kidney function. Endothelial dysfunction emerges as a critical factor, emphasizing the importance of monitoring ADMA levels, which can independently predict worse cardiovascular outcomes. Managing hyperglycemia, hypertension, and dyslipidemia is pivotal for reducing cardiovascular risks in diabetic patients. Further exploration of preventive strategies is warranted.

Metabolomic and lipidomic pathways in aneurysmal subarachnoid hemorrhage

Aneurysmal subarachnoid hemorrhage (aSAH) results in a complex systemic response that is critical to the pathophysiology of late complications and has important effects on outcomes. Omics techniques have expanded our investigational scope and depth into this phenomenon. In particular, metabolomics-the study of small molecules, such as blood products, carbohydrates, amino acids, and lipids-can provide a snapshot of dynamic subcellular processes and thus broaden our understanding of molecular-level pathologic changes that lead to the systemic response after aSAH. Lipids are especially important due to their abundance in the circulating blood and numerous physiological roles. They are comprised of a wide variety of subspecies and are critical for cellular energy metabolism, the integrity of the blood-brain barrier, the formation of cell membranes, and intercellular signaling including neuroinflammation and ferroptosis. In this review, metabolomic and lipidomic pathways associated with aSAH are summarized, centering on key metabolites from each metabolomic domain.

Association of Circulating Neprilysin with BMI, Cardiovascular Health, and Kidney Function in High-Risk Pregnancies: A Pilot Study

BACKGROUND/OBJECTIVES

Inadequate cardiovascular adaptation during pregnancy impairs endothelial function and vascular resistance, contributing to complications such as pre-eclampsia (PE) and gestational hypertension (GH). Neprilysin (NEP), a protease involved in vascular regulation, has been linked to PE, but its role in endothelial function and vascular adaptation remains unclear. This pilot study investigates the associations between soluble neprilysin (sNEP) and markers of vascular and renal function in high-risk pregnancies without PE.

METHODS

Observed parameters were analyzed in 29 high-risk pregnant women across early, mid-, and late pregnancy. sNEP levels were analyzed alongside body mass index (BMI), endothelial dysfunction (ADMA), arterial stiffness (pulse wave velocity, PWV), retinal microvasculature (central retinal arteriolar and venular equivalents, CRAE and CRVE), and kidney function markers. The impact of gestational hypertension (GH) and prior smoking on sNEP levels was also evaluated.

RESULTS

In early and mid-pregnancy, sNEP was inversely associated with BMI. During mid-pregnancy, sNEP showed a positive correlation with CRAE and an inverse correlation with PWV, suggesting reduced arterial stiffness. By late pregnancy, sNEP was positively associated with glomerular filtration rate and inversely correlated with creatinine and protein levels, reflecting improved kidney function. Women with GH exhibited elevated sNEP, while former smokers had lower sNEP levels in early pregnancy.

CONCLUSIONS

These findings suggest that sNEP plays a role in vascular and renal adaption during pregnancy, offering new perspectives on vascular tone regulation in high-risk pregnancies. Further research is needed to clarify these mechanisms and their clinical relevance.

Secondary Brain Injury After Parenchymal Cerebral Hemorrhage in Humans: The Role of NOX2-Mediated Oxidative Stress and Endothelin-1

Perihematomal hypoperfusion may lead to ischemic damage during intraparenchymal cerebral hemorrhage (ICH), resulting in worse prognosis. We aimed to (1) investigate the relationship between serum biomarkers related to oxidative stress and vasoactive substances and the occurrence of hypoperfusion and ischemic perihematomal lesions in ICH and (2) evaluate their correlation with the volumetric evolution of the hematoma and perihematomal edema. We enrolled 28 patients affected by ICH. Blood samples were collected at three different time points from symptom onset: T0, T1, and T2 (admission, 12-24 h, and 48-72 h, respectively), to measure endothelin-1 (ET-1), nitrites/nitrates (NO), soluble nicotinamide adenine dinucleotide 2 (NOX2)-derived peptide (sNOX2-dp), and asymmetric dimethylarginine (ADMA). Patients underwent brain MRI with perfusion study at T1 and MRI without perfusion at T2. 12 patients had ischemic perihematomal lesions at T1. A higher sNOX2-dp concentration at T0 was observed in patients with ischemic perihematomal lesions compared to those without (p = 0.051) and with a more severe perihematomal edema at T2 (p = 0.011). The ischemic perihematomal lesions development was also associated with an increased hematoma volume (p < 0.005), perilesional edema (p = 0.046), and greater midline shift (p = 0.036). ET-1 values at T1 were inversely correlated with hemorrhage volume at T2 (ρ = -0.717, p = 0.030). NOX2 activation may have a role in the development of ischemic perihematomal lesions. The association between higher ET-1 values and a lower hemorrhage volume could be related to the ET-1 vasoconstriction action on the ruptured vessel wall.

Metabolomic Hallmarks of Obesity and Metabolic Dysfunction-Associated Steatotic Liver Disease

From a detailed review of 90 experimental and clinical metabolomic investigations of obesity and metabolic dysfunction-associated steatotic liver disease (MASLD), we have developed metabolomic hallmarks for both obesity and MASLD. Obesity studies were conducted in mice, rats, and humans, with consensus biomarker groups in plasma/serum being essential and nonessential amino acids, energy metabolites, gut microbiota metabolites, acylcarnitines and lysophosphatidylcholines (LPC), which formed the basis of the six metabolomic hallmarks of obesity. Additionally, mice and rats shared elevated cholesterol, humans and rats shared elevated fatty acids, and humans and mice shared elevated VLDL/LDL, bile acids and phosphatidylcholines (PC). MASLD metabolomic studies had been performed in mice, rats, hamsters, cows, geese, blunt snout breams, zebrafish, and humans, with the biomarker groups in agreement between experimental and clinical investigations being energy metabolites, essential and nonessential amino acids, fatty acids, and bile acids, which lay the foundation of the five metabolomic hallmarks of MASLD. Furthermore, the experimental group had higher LPC/PC and cholesteryl esters, and the clinical group had elevated acylcarnitines, lysophosphatidylethanolamines/phosphatidylethanolamines (LPE/PE), triglycerides/diglycerides, and gut microbiota metabolites. These metabolomic hallmarks aid in the understanding of the metabolic role played by obesity in MASLD development, inform mechanistic studies into underlying disease pathogenesis, and are critical for new metabolite-inspired therapies.

Chronic Viral Reactivation and Associated Host Immune Response and Clinical Outcomes in Acute COVID-19 and Post-Acute Sequelae of COVID-19

Chronic viral infections are ubiquitous in humans, with individuals harboring multiple latent viruses that can reactivate during acute illnesses. Recent studies have suggested that SARS-CoV-2 infection can lead to reactivation of latent viruses such as Epstein-Barr Virus (EBV) and cytomegalovirus (CMV), yet, the extent and impact of viral reactivation in COVID-19 and its effect on the host immune system remain incompletely understood. Here we present a comprehensive multi-omic analysis of viral reactivation of all known chronically infecting viruses in 1,154 hospitalized COVID-19 patients, from the Immunophenotyping Assessment in a COVID-19 Cohort (IMPACC) study, who were followed prospectively for twelve months. We reveal significant reactivation of Herpesviridae, Enteroviridae, and Anelloviridae families during acute stage of COVID-19 (0-40 days post-hospitalization), each exhibiting distinct temporal dynamics. We also show that viral reactivation correlated with COVID-19 severity, demographic characteristics, and clinical outcomes, including mortality. Integration of cytokine profiling, cellular immunophenotyping, metabolomics, transcriptomics, and proteomics demonstrated virus-specific host responses, including elevated pro-inflammatory cytokines (e.g. IL-6, CXCL10, and TNF), increased activated CD4+ and CD8+ T-cells, and upregulation of cellular replication genes, independent of COVID-19 severity and SARS-CoV-2 viral load. Notably, persistent Anelloviridae reactivation during convalescence (≥3 months post-hospitalization) was associated with Post-Acute Sequelae of COVID-19 (PASC) symptoms, particularly physical function and fatigue. Our findings highlight a remarkable prevalence and potential impact of chronic viral reactivation on host responses and clinical outcomes during acute COVID-19 and long term PASC sequelae. Our data provide novel immune, transcriptomic, and metabolomic biomarkers of viral reactivation that may inform novel approaches to prognosticate, prevent, or treat acute COVID-19 and PASC.

SGLT2 inhibition improves coronary flow velocity reserve and contractility: role of glucagon signaling

BACKGROUND

SGLT2 inhibitors, a T2DM medication to lower blood glucose, markedly improve cardiovascular outcomes but the underlying mechanism(s) are not fully understood. SGLT2i's produce a unique metabolic pattern by lowering blood glucose without increasing insulin while increasing ketone body and glucagon levels and reducing body weight. We tested if glucagon signaling contributes to SGLT2i induced improvement in CV function.

METHODS

Cardiac contractility and coronary flow velocity reserve (CFVR) were monitored in ob/ob mice and rhesus monkeys with metabolic syndrome using echocardiography. Metabolic status was characterized by measuring blood ketone levels, glucose tolerance during glucose challenge and Arg and ADMA levels were measured. Baysian models were developed to analyse the data.

RESULTS

Dapagliflozin improved CFVR and contractility, co-application of a glucagon receptor inhibitor (GcgRi) blunted the effect on CFVR but not contractility. Dapagliflozin increased the Arg/ADMA ratio and ketone levels and co-treatment with GcgRi blunted only the Dapagliflozin induced increase in Arg/ADMA ratio but not ketone levels.

CONCLUSIONS

Since GcgRi co-treatment only reduced the Arg/ADMA increase we hypothesize that dapagliflozin via a glucagon-signaling dependent pathway improves vascular function through the NO-signaling pathway leading to improved vascular function. Increase in ketone levels might be a contributing factor in SGLT2i induced contractility increase and does not require glucagon signaling.

Age-Associated Alterations in the Metabolome of Human Vitreous in Bacterial Endophthalmitis

Purpose

Endophthalmitis is a severe inflammatory condition due to intraocular infections that often leads to irreversible blindness. This study aimed to understand the age-dependent metabolic alterations in the vitreous of patients with bacterial endophthalmitis.

Methods

The study included the vitreous metabolome of patients with bacterial endophthalmitis (group 1, n = 15) and uninfected controls (group 2, n = 14), which were further stratified into three groups according to their age: young (0-30 years), middle (31-60 years), and elderly (>60 years). Vitreous samples were subjected to untargeted metabolomic analysis using high-resolution mass spectrometry (HRMS)m and acquired mass spectrometry data were analyzed using MetaboAnalyst 6.0. The altered metabolites with log2FC of ≥2/≤2, P < 0.05, and variable importance in projection > 1 were considered significant.

Results

In a total of 109 endogenous metabolites identified, young and elderly patients with endophthalmitis showed 52 (elevated, 25; reduced, 27; P < 0.05) and 27 (elevated, 19; reduced, 8; P < 0.05) significantly altered metabolites, respectively, compared to their age-matched controls. Additionally, 27 metabolites were differentially expressed in young patients with endophthalmitis compared to the older group. The crucial metabolic pathways dysregulated in the older infected population were de novo purine synthesis and salvage, carnitine, polyamine (spermidine), lipids (prostaglandins), and amino acid (taurine, methionine, histidine) which could possibly be attributed to the increased disease severity and inflammation observed in a clinical setting.

Conclusions

Despite the erratic metabolic changes observed in the younger group infected with endophthalmitis when compared to age-matched controls, dysregulation in the specific pathways such as purine, carnitine, arachidonic acid, and polyamine metabolism could possibly alter the immunological exacerbation observed in the older group.

Asymmetric dimethylarginine induces maladaptive function of the blood-brain barrier

Growing body of evidence suggests that cardiovascular risk factor, asymmetric dimethylarginine (ADMA), can be implicated in the pathogenesis of neurodegenerative and psychiatric disorders. In part, ADMA can affect brain health negatively modulating critical functions of the blood-brain barrier (BBB). The precise mechanisms and consequences of ADMA action on the cerebral vasculature remains unexplored. Here, we evaluated ADMA-induced maladaptation of BBB functions by analyzing real time electrical cell-substrate impedance, paracellular permeability, immune-endothelial interactions, and inflammatory cytokines production by primary human brain microvascular endothelial cells (hBMVEC) treated with ADMA. We found that ADMA disrupted physical barrier function as evident by significant decrease in electrical resistance and increase in paracellular permeability of hBMVEC monolayers. Next, ADMA triggered immune-endothelial interactions since adhesion of primary human monocytes and their extravasation across the endothelial monolayer both were significantly elevated upon treatment with ADMA. Increased levels of cell adhesion molecules (VCAM-1 and RANTES), VEGF-A and inflammatory cytokines (IL-1β, TNF-α, IL-6, IL-10, IL-4, IL-2, IL-13, IL-12p70) characterize ADMA-induced hBMVEC dysfunction as inflammatory. Overall, our data suggest that ADMA can impair BBB functions disrupting the endothelial barrier and eliciting neuroinflammatory and neuroimmune responses.

Use of direct oral anticoagulants in patients on chronic hemodialysis: Contemporary appraisal on the role for patients with atrial fibrillation

Atrial fibrillation (AF) is common in patients with chronic kidney disease (CKD) undergoing hemodialysis and in this patient population, management in terms of oral anticoagulation (OAC) presents unique challenges due to the increased risk of both thromboembolic events and bleeding complications. The attributable risk of AF for stroke may differ from patients without CKD, raising the question if OAC is indicated at all. Historically, vitamin K antagonists (VKA) have been the standard treatment for anticoagulation in AF; however, direct oral anticoagulants (DOACs) have emerged as an alternative therapeutic option, whereby data from prospective randomised trials with hemodialysis patients is limited resulting in great variability of practice and guideline recommendations. This review summarizes existing data sources regarding the use and benefit of oral anticoagulation with VKA and DOAC in hemodialysis patients.

Asymmetric Dimethylarginine as a Potential Mediator in the Association between Periodontitis and Cardiovascular Disease: A Systematic Review of Current Evidence

Background: Periodontitis, a chronic inflammatory disease, has been associated with an elevated risk of cardiovascular disease (CVD). Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, has emerged as a potential biomarker linking periodontitis, endothelial dysfunction, and CVD. This systematic review aimed to synthesize the existing evidence on the relationship between ADMA, periodontitis, and CVD, and to evaluate ADMA's potential as a biomarker for periodontal disease progression and its correlation with endothelial dysfunction. Methods: A comprehensive literature search was conducted in PubMed, Scopus, and Web of Science databases from their inception to March 2023. Observational and interventional studies assessing ADMA levels in patients with periodontitis and/or CVD were included. The methodological quality of the included studies was evaluated using the NIH Quality Assessment Tools. Due to the heterogeneity of the included studies, a qualitative synthesis was performed. Results: Cross-sectional studies consistently demonstrated significantly elevated ADMA levels in patients with periodontitis and CVD compared to healthy controls. The prospective cohort study indicated that successful periodontal treatment was associated with a significant reduction in ADMA levels and concomitant improvement in endothelial function. The pilot cohort study reported a significant decrease in ADMA levels following periodontal therapy in patients with chronic kidney disease. However, the randomized controlled trials did not demonstrate significant alterations in ADMA levels or endothelial function subsequent to periodontal treatment in patients with periodontitis alone. Conclusions: Periodontal treatment may effectively reduce ADMA levels and improve endothelial function, particularly in patients with comorbidities. These findings suggest that ADMA is a promising biomarker linking periodontitis, endothelial dysfunction, and CVD. However, the limitations of this study include the small number of studies, heterogeneity in the study designs, and a lack of long-term follow-up data. Further high-quality, longitudinal studies are required to confirm its clinical utility and elucidate the underlying mechanisms of these relationships. The integration of periodontal care into CVD prevention and management strategies warrants consideration, as it may contribute to mitigating the cardiovascular risk associated with periodontitis.

Asymmetric dimethylarginine serum concentration in normal weight and obese CKD patients treated with hemodialysis

INTRODUCTION

Asymmetric dimethylarginine (ADMA), a cardiovascular risk factor, increases in renal failure. The aim of this study was to investigate ADMA levels in normal weight and obese patients on hemodialysis.

METHODS

In this cross-sectional study, 43 normal weight and 43 obese patients on regular hemodialysis were examined. Malnutrition-inflammation score (MIS), anthropometry, circulating ADMA, lipid profiles including triglycerides (TG), total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL) and lipid ratios, glucose homeostasis parameters, blood pressure, and high-sensitivity C-reactive protein (hs-CRP) were assessed.

RESULTS

Serum levels of ADMA were significantly lower in the obese compared to the normal weight patients (10268.2 ± 10092.4 vs. 13765.2 ± 9951.3 ng/l, P = 0.03). At the same time MIS score (6.1 ± 2.4 vs. 10.7 ± 3.2, P < 0.001), systolic blood pressure (119 ± 26.8 vs. 134.2 ± 24.7 mmHg, P = 0.018) and mean arterial pressure (91.3 ± 18.6 vs. 100.9 ± 15.9 mmHg, P = 0.028) were significantly lower in the obese than the normal weight group. Fasting blood glucose (P = 0.045), TG/HDL (P = 0.03), TC/HDL (P = 0.019), and LDL/HDL (P = 0.005) ratios, and hs-CRP (P = 0.015) levels were significantly higher in the obese than in the normal weight group.

CONCLUSION

Circulating ADMA was significantly lower in obese than in normal weight patients on hemodialysis, which was concomitant with lower MIS, indicating a better nutritional inflammatory status, and lower blood pressure.

Oxidative stress and aging: synergies for age related diseases

Aging is characterized by a progressive decline in physiological function and underlies several disabilities, including the increased sensitivity of cells and tissues to undergo pathological oxidative stress. In recent years, efforts have been made to better understand the relationship between age and oxidative stress and further develop therapeutic strategies to minimize the impact of both events on age-related diseases. In this work, we review the impact of the oxidant and antioxidant systems during aging and disease development and discuss the crosstalk of oxidative stress and other aging processes, with a focus on studies conducted in elderly populations.

The protective role of GATA6+ pericardial macrophages in pericardial inflammation

Prior research has suggested that GATA6+ pericardial macrophages may traffic to the myocardium to prevent interstitial fibrosis after myocardial infarction (MI), while subsequent literature claims that they do not. We demonstrate that GATA6+ pericardial macrophages are critical for preventing IL-33 induced pericarditis and attenuate trafficking of inflammatory monocytes and granulocytes to the pericardial cavity after MI. However, absence of GATA6+ macrophages did not affect myocardial inflammation due to MI or coxsackievirus-B3 induced myocarditis, or late-stage cardiac fibrosis and cardiac function post MI. GATA6+ macrophages are significantly less transcriptionally active following stimulation in vitro compared to bone marrow-derived macrophages and do not induce upregulation of inflammatory markers in fibroblasts. This suggests that GATA6+ pericardial macrophages attenuate inflammation through their interactions with surrounding cells. We therefore conclude that GATA6+ pericardial macrophages are critical in modulating pericardial inflammation, but do not play a significant role in controlling myocardial inflammation or fibrosis.

Oral Supplementation with Betaine Powder Ameliorated High Blood Pressure in Spontaneously Hypertensive Rats

Supplementation of betaine is associated with improved cardiac health, potentially due to its function in re-methylation of homocysteine, an independent risk factor for cardiovascular diseases. We investigated the effects of oral betaine supplementation on blood pressure homeostasis in spontaneously hypertensive (SHR) rats and Wistar Kyoto (WKY) rats in an 8 week-feeding trial with control (SHR-con and WKY-con) and 1% betaine supplemented (SHR-b and WKY-b) diets. Systolic, diastolic, and mean blood pressure in the SHR-b group were significantly lower at week 8 (p = 0.013, p = 0.011, p = 0.010, respectively). Furthermore, serum nitric oxide (NO) levels were significantly (p < 0.05) improved in the WKY-b and SHR-b groups, suggesting a healthy endothelial function. Additionally, the serum angiotensin I converting enzyme level in SHR-b rats was also significantly lowered, which may have been another reason for lower blood pressure. A significantly higher non-HDL level in the SHR-b group might reflect enhanced lipid secretion into the circulation in the form of very-low-density lipoprotein (VLDL). Betaine is known for its effect on the synthesis of phosphatidylcholine, a key component of VLDL. However, the long-term net outcomes of both blood pressure lowering and serum lipid increment should be further studied.

High ADMA Is Associated with Worse Health Profile in Heart Failure Patients Hospitalized for Episodes of Acute Decompensation

Background and Objectives: episodes of acute decompensation in chronic heart failure (ADHF), a common health problem for the growing elderly population, pose a significant socio-economic burden on the public health systems. Limited knowledge is available on both the endothelial function in and the cardio-metabolic health profile of old adults hospitalized due to ADHF. This study aimed to investigate the connection between asymmetric dimethylarginine (ADMA)-a potent inhibitor of nitric oxide-and key health biomarkers in this category of high-risk patients. Materials and Methods: this pilot study included 83 individuals with a known ADHF history who were admitted to the ICU due to acute cardiac decompensation. Selected cardiovascular, metabolic, haemogram, renal, and liver parameters were measured at admission to the ICU. Key renal function indicators (serum creatinine, sodium, and potassium) were determined again at discharge. These parameters were compared between patients stratified by median ADMA (114 ng/mL). Results: high ADMA patients showed a significantly higher incidence of ischemic cardiomyopathy and longer length of hospital stay compared to those with low ADMA subjects. These individuals exhibited significantly higher urea at admission and creatinine at discharge, indicating poorer renal function. Moreover, their lipid profile was less favorable, with significantly elevated levels of total cholesterol and HDL. However, no significant inter-group differences were observed for the other parameters measured. Conclusions: the present findings disclose multidimensional, adverse ADMA-related changes in the health risk profile of patients with chronic heart failure hospitalized due to recurrent decompensation episodes.

Endothelial Dysfunction as a Key Link between Cardiovascular Disease and Frailty: A Systematic Review

Background: Frailty is increasingly recognized as a significant health concern, particularly due to its association with cardiovascular pathologies. This study aims to examine how vascular endothelial dysfunction, a known premorbid stage in the pathophysiology of cardiovascular diseases, contributes to the link between cardiovascular illness and frailty. Methods: The inclusion criteria allowed us to focus on original clinical research articles published in English between January 2014 and January 2024, which reported quantitative assessments of the relationship between frailty and vascular endothelial dysfunction. Excluded from the study were systematic literature reviews, meta-analyses, editorials, conference articles, theses, methodological articles, and studies using animal or cell culture models. Searches were conducted of electronic databases, including Scopus, ScienceDirect, and Medline, up to 22 January 2024. The risk of bias was assessed using the Joanna Briggs Institute's critical appraisal tools. The methods used to present and synthesize the results involved data extraction and categorization based on biomolecular and clinical findings of endothelial dysfunction. Results: Following the application of the inclusion and exclusion criteria, a total of 29 studies were identified. Vascular endothelial dysfunction was associated with increased frailty phenotypes, and we also identified SGLT-2 inhibitors' potential role as an anti-fragility treatment that affects endothelial dysfunction. This study found that the physical and biomolecular markers of endothelial dysfunction are associated with frailty measures and have predictive value for incident frailty. Furthermore, some studies have shown inflammation to have an impact on endothelial dysfunction and frailty, and an innovative age-related chronic inflammation measure has been proven to predict frailty scores. Conclusions: The current evidence suggests an association between endothelial dysfunction and frailty, highlighting the need for further research to elucidate the underlying mechanisms.

New insight into arginine and tryptophan metabolism in macrophage activation during tuberculosis

Arginine and tryptophan are pivotal in orchestrating cytokine-driven macrophage polarization and immune activation. Specifically, interferon-gamma (IFN-γ) stimulates inducible nitric oxide synthase (iNOS) expression), leading to the conversion of arginine into citrulline and nitric oxide (NO), while Interleukin-4 (IL4) promotes arginase activation, shifting arginine metabolism toward ornithine. Concomitantly, IFN-γ triggers indoleamine 2,3-dioxygenase 1 (IDO1) and Interleukin-4 induced 1 (IL4i1), resulting in the conversion of tryptophan into kynurenine and indole-3-pyruvic acid. These metabolic pathways are tightly regulated by NAD+-dependent sirtuin proteins, with Sirt2 and Sirt5 playing integral roles. In this review, we present novel insights that augment our understanding of the metabolic pathways of arginine and tryptophan following Mycobacterium tuberculosis infection, particularly their relevance in macrophage responses. Additionally, we discuss arginine methylation and demethylation and the role of Sirt2 and Sirt5 in regulating tryptophan metabolism and arginine metabolism, potentially driving macrophage polarization.

The correlation of ADMA with proinflammatory, liver injury and cancer biomarkers in patients with liver dysfunction

Background and Aim

Asymmetric dimethylarginine (ADMA) is an enzyme involved in vascular tone, blood pressure, and platelet activation. Serum ADMA levels are increased in liver diseases such as liver cirrhosis, hepatitis, and acute liver failure. The aim of our study was to assess the correlation of ADMA with proinflammatory, liver injury, and cancer biomarkers in patients with liver dysfunction of various etiologies.

Materials and Methods

We analyzed the demographic and clinical data, including serum ADMA concentration and other biochemical markers such as albumin, platelet count, international normalized ratio, bilirubin, and others in patients with hepatitis, compensated and decompensated liver cirrhosis, and hepatocellular carcinoma. The one-way ANOVA, Student's t-test, Mann-Whitney U test, univariate, and multivariate correlations were performed, and a p-value <0.05 was set as significant.

Results

In n=83 analyzed patients, we observed a negative correlation of ADMA with albumin concentration (p=0.049). We found a negative correlation between ADMA and platelet count in n=31 patients with compensated liver cirrhosis (p=0.022). We observed no significant correlations of ADMA with proinflammatory and cancer biomarkers in patients with hepatitis, compensated and decompensated liver cirrhosis, and hepatocellular carcinoma.

Conclusion

ADMA can potentially be used as a subsidiary marker of disease progression in patients with liver dysfunction. Our research suggests that ADMA cannot be useful in detecting hepatocellular carcinoma (HCC).

New Insights into Endothelial Dysfunction in Cardiometabolic Diseases: Potential Mechanisms and Clinical Implications

The endothelium is a monocellular layer covering the inner surface of blood vessels. It maintains vascular homeostasis regulating vascular tone and permeability and exerts anti-inflammatory, antioxidant, anti-proliferative, and anti-thrombotic functions. When the endothelium is exposed to detrimental stimuli including hyperglycemia, hyperlipidemia, and neurohormonal imbalance, different biological pathways are activated leading to oxidative stress, endothelial dysfunction, increased secretion of adipokines, cytokines, endothelin-1, and fibroblast growth factor, and reduced nitric oxide production, leading eventually to a loss of integrity. Endothelial dysfunction has emerged as a hallmark of dysmetabolic vascular impairment and contributes to detrimental effects on cardiac metabolism and diastolic dysfunction, and to the development of cardiovascular diseases including heart failure. Different biomarkers of endothelial dysfunction have been proposed to predict cardiovascular diseases in order to identify microvascular and macrovascular damage and the development of atherosclerosis, particularly in metabolic disorders. Endothelial dysfunction also plays an important role in the development of severe COVID-19 and cardiovascular complications in dysmetabolic patients after SARS-CoV-2 infection. In this review, we will discuss the biological mechanisms involved in endothelial dysregulation in the context of cardiometabolic diseases as well as the available and promising biomarkers of endothelial dysfunction in clinical practice.

Recombinant soluble form of receptor for advanced glycation end products ameliorates microcirculation impairment and neuroinflammation after subarachnoid hemorrhage

Impaired cerebral microcirculation after subarachnoid hemorrhage (SAH) has been shown to be related to delayed ischemic neurological deficits (DIND). We previously demonstrated the involvement of the receptor for advanced glycation end products (RAGE) in the pathogenesis of SAH related neuronal death. In the present study, we aimed to investigate the therapeutic effects of a recombinant soluble form of RAGE (sRAGE) on microcirculation impairment following SAH. Intrathecal injection of autologous blood in rats, mixed primary astrocyte and microglia cultures exposed to hemolysates and endothelial cells ​(ECs) from human brain microvascular exposed to glia-conditioned medium or SAH patient's CSF were used as experimental SAH models in vivo and in vitro. The results indicated that intrathecal administration of recombinant sRAGE significantly ameliorated the vasoconstriction of cortical arterioles and associated perfusion impairment, brain edema, reduced cell death, endothelial dysfunction, and improved motor performance at 24 and 48 ​h after SAH induction in rats. The in vitro results further showed that recombinant sRAGE significantly reduced astrocyte swelling and microglia activation, in parallel with decreased mRNA expression levels of pro-inflammatory cytokines including interleukin-6 (IL-6) and interleukin-1β (IL-1β) in vitro. Moreover, the in vitro model of SAH-induced p-eNOS and eNOS suppression, along with stress fiber formation in brain microvascular ECs, was effectively reversed by sRAGE treatment and led to a decrease in cleaved-caspase 3 expression. In summary, recombinant sRAGE effectively lessened microcirculation impairment and vascular injury after SAH via the mechanism of anti-inflammation, which may provide a potential therapeutic strategy for SAH.

Serum endocan, asymmetric dimethylarginine and lipid profile in children with familial Mediterranean fever

BACKGROUND

Familial Mediterranean fever (FMF) is a chronic inflammatory disease, and it is thought that subclinical inflammation persists even when there are no attacks, eventually causing endothelial dysfunction (ED) and atherosclerosis. Limited data are available about serum endocan, asymmetric dimethylarginine (ADMA) and lipid profile in children with FMF, so we aimed to evaluate these markers in children with FMF during the attack-free period.

METHODS

A total of 50 patients diagnosed with FMF and 50 age and sex-matched healthy children were recruited. Serum endocan, ADMA and lipid profiles were measured. Also, atherogenic indices (Castelli's risk indices I and II [CRI I and II], atherogenic index of plasma [AIP] and atherogenic coefficient [AC]) were calculated.

RESULTS

Serum endocan, ADMA levels, low-density lipoprotein cholesterol, triglycerides, CRI II and AIP of the FMF patients were significantly higher than controls (p < 0.001). Unlike serum endocan, serum ADMA showed a positive significant correlation with total cholesterol, non-high density lipoprotein cholesterol, CRI I, AIP and AC (p < 0.001, p < 0.001, p = 0.004, p = 0.028, p = 0.004 respectively).

CONCLUSION

Serum ADMA and lipid profile might be used as potential markers for endothelial dysfunction and increased cardiovascular risk in FMF patients.

IMPACT

Theoretically, serum ADMA may affect lipid profiles and serum endocan represents an intriguing biomarker related to inflammation. Coexistence of dyslipidemia represents an additional risk factor that contributes to the onset of early atherosclerosis. A few studies investigated the role of changes in lipid profile and lipid ratios in accelerated atherosclerosis pathogenesis in FMF patients. The relationship between colchicine and lipid profile is contradictory. Although colchicine can cause dyslipidemia, it also has anti-atherosclerosis effects. Elevated ADMA level and atherogenic indices in FMF children reflect their potential role in the early detection of cardiovascular affection in FMF patients.

Strong Association of Metabolic Parameters with ADMA and VCAM-1 in Normo-Weight Subjects with Metabolic Syndrome

Background

Metabolic syndrome (MetS) is a risk factor for cardiovascular disease and is linked to obesity. Subjects with MetS who have normo-weight potentially show higher mortality and morbidity.

Purpose

This study aims to reveal the critical essential metabolic parameters associated with endothelial dysfunction in MetS subjects with normo-weight compared to obese.

Patients and Methods

The study was designed using a case-control approach. Ninety-nine MetS subjects (34 Normo-weight and 65 obese) from the urban population were enrolled in this study. The components of MetS are based on NCEP/ATP III criteria. Asymmetric dimethylarginine (ADMA) and vascular cell adhesion molecule 1 (VCAM-1) as markers for endothelial dysfunction were measured in both groups.

Results

Fasting blood glucose (FBG) levels were higher in the normo-weight group (143.38 ± 79.8 mg/dL) compared to the obese group (120.89 ± 46.5 mg/dL). High-density lipoprotein cholesterol (HDL-c) levels in the normo-weight group were lower (42.82 ± 10.1 mg/dL) compared to obesity (45.74 ± 9.3 mg/dL), while triacylglycerol (TAG) levels were higher in the obese (197.25 ± 110.5 mg/dL) compared to the normo-weight group (167.03 ± 98.4 mg/dL), although the differences were statistically not significant (all p > 0.05). The difference between ADMA and VCAM-1 levels was statistically not significant in both groups. Correlation between MetS components with endothelial dysfunction parameters shows that metabolic parameters correlate strongly. Interestingly, a stronger correlation between FBG and ADMA was observed in normo-weight (r = 0.519) compared to obese groups (r = 0.445). In addition, TAG consistently shows a significant correlation with ADMA and VCAM-1 in normo-weight groups.

Conclusion

Metabolic parameters, especially FBG and TAG, correlate strongly with endothelial dysfunction parameters in normo-weight subjects with metabolic syndrome.

Heparin-Mediated Extracorporeal Low-Density Lipoprotein Precipitation Apheresis for Treating Peripheral Arterial Disease in Patients with Chronic Kidney Disease

Patients with chronic kidney disease (CKD), particularly those with end-stage renal disease (ESRD), have a high prevalence of cardiovascular disease and peripheral arterial disease (PAD). Medical treatment is mainly based on risk factor management, and the surgical approach remains the gold standard treatment in specific conditions. Heparin-mediated extracorporeal low-density lipoprotein precipitation (H.E.L.P.) apheresis is effective in reducing circulating lipoprotein, fibrinogen, inflammatory mediators and procoagulant factors, thereby reducing cardiovascular risk in patients with familial hypercholesterolemia and hypertriglyceridemia. These activities may be effective in reducing symptoms and ischemic vascular lesions even in patients with severe PAD. We reported the application of a treatment protocol with H.E.L.P. apheresis in an ESRD patient with severe PAD without clinical improvement after severe revascularization who was not suitable for further surgical approaches, despite normal LDL cholesterol and lipoprotein (a). The H.E.L.P. protocol was characterized by an intensive first phase with weekly treatments followed by a single session every 10-15 days for 6 months of treatment. The overall clinical condition, foot lesions and walking distance improved significantly after the first 2 months of treatment, and foot amputation was avoided. Here, we review the main pathogenetic mechanisms through which LDL apheresis improves microcirculation and clinical outcomes. Its wider application may represent an optimal therapeutic option for patients unresponsive to standard treatment.

A Set of Possible Markers for Monitoring Heart Failure and Cognitive Impairment Associated: A Review of Literature from the Past 5 Years

BACKGROUND

Heart failure is an epidemiologically relevant disease because of the aging population and widespread lifestyles that promote it. In addition to the acute event, it is possible for the disease to become chronic with periodic flare-ups. It is essential to study pathology from a diagnostic and prognostic point of view and to identify parameters for effective monitoring. In addition, heart failure is associated with multiple comorbidities, including cognitive impairment, which is monitored clinically but not through specific biomarkers in these patients. The purpose of this review is to gather the most recent scientific evidence on a few possible biomarkers previously identified for monitoring heart failure and associated cognitive impairment.

METHODS

We surveyed studies inherent to a set of previously identified markers, evaluating English-language articles from the past five years conducted in adult heart failure patient populations. We used the databases PubMed, Web of Sciences, and Cochrane Library for search studies, and we considered articles published in journals with an impact factor greater than five in the publication year.

RESULTS

Among the biomarkers evaluated, a concordant indication for serial measurements for heart failure monitoring emerged only for interleukin-6. For the other markers, there is still little evidence available, which is interesting but sometimes conflicting. Interesting studies have also emerged for biomarkers of cognitive decline assessed in patients with heart failure, confirming the hypotheses of the increasingly studied heart-brain correlation.

CONCLUSION

Certainly, further studies in large populations are needed to identify effective biomarkers for monitoring heart failure and associated cognitive impairment.

Daily Consumption of Golden Berry (Physalis peruviana) Has Been Shown to Halt the Progression of Insulin Resistance and Obesity in Obese Rats with Metabolic Syndrome

In a study addressing the high risk of chronic diseases in people with diabetes and obesity linked to metabolic syndrome, the impact of a Golden Berry diet was investigated using a diabetic animal model. Obese rats with diabetic characteristics were fed a diet containing five percent Golden Berry for 16 days. This study focused on various parameters including organ weights, expression of metabolic genes, and urinary biomarkers. Post-Golden Berry intake, there was a notable decrease in the body, liver, pancreas, visceral, and subcutaneous adipose tissue weights in these obese, hyperglycemic rats. In contrast, an increase in brown adipose tissue (BAT) cell mass was observed. This diet also resulted in reduced blood glucose levels and normalized plasma biochemical profiles, including cholesterol, triglycerides, LDL, and HDL levels. Additionally, it modulated specific urinary biomarkers, particularly pipe-colic acid, a primary marker for type 2 diabetes. Bioinformatics analysis linked these dietary effects to improved insulin signaling and adipogenesis. Regular consumption of Golden Berry effectively prevented insulin resistance and obesity in rats, underscoring its significant health benefits and the protective role of an antioxidant-rich diet against metabolic syndrome. These findings offer promising insights for future therapeutic strategies to manage and prevent obesity and related chronic diseases.

A metabolomics perspective on 2 years of high-intensity training in horses

The plasma metabolomic profile of elite harness horses subjected to different training programmes was explored. All horses had the same training programme from 1.5 until 2 years of age and then high-intensity training was introduced, with horses divided into high and low training groups. Morning blood samples were collected at 1.5, 2, 2.5 and 3.5 years of age. The plasma was analysed using targeted absolute quantitative analysis and a combination of tandem mass spectrometry, flow-injection analysis and liquid chromatography. Differences between the two training groups were observed at 2 years of age, when 161 metabolites and sums and ratios were lower (e.g. ceramide and several triglycerides) and 51 were higher (e.g. aconitic acid, anserine, sum of PUFA cholesteryl esters and solely ketogenic AAs) in High compared with low horses. The metabolites aconitic acid, anserine, leucine, HArg synthesis and sum of solely ketogenic AAs increased over time, while beta alanine synthesis, ceramides and indole decreased. Therefore high-intensity training promoted adaptations linked to aerobic energy production and amino acid metabolism, and potentially also affected pH-buffering and vascular and insulin responses.

Effect of Yoga-Based Cardiac Rehabilitation Program on Endothelial Function, Oxidative Stress, and Inflammatory Markers in Acute Myocardial Infarction: A Randomized Controlled Trial

Aims

The aim of this study was to evaluate the effects of yoga-based cardiac rehabilitation (Yoga-CaRe) on the endothelial system, oxidative stress, and inflammatory markers in patients with acute myocardial infarction (MI).

Methods

A sub-study was conducted in two clinical sites of the Yoga-CaRe trial (a multicenter randomized controlled trial). Participants with acute MI were randomized and allocated to either the Yoga-CaRe program (13 sessions with encouragement to home practice) or enhanced standard care (three educational sessions). Endothelial function, oxidative stress, and inflammatory biomarkers were assessed using biomarkers such as asymmetric dimethylarginine (ADMA), endothelial nitric oxide synthase (eNOS), endothelin-1 (ET-1), E-selectin, P-selectin, vascular cell adhesion molecule (VCAM), intercellular cell-adhesion molecule-1, total nitric oxide concentration (NOx), oxidized low-density lipoprotein (Oxd-LDL), superoxide dismutase, total antioxidant capacity (TAOC), tumor necrosis factor-alpha (TNFα), and C-reactive protein (CRP) at baseline and 12 weeks. Laboratory and statistical analysis were done by staff blinded to group allocation.

Results

Eighty-two patients (of the 110 patients recruited) completed the study. The mean age was 53.1 ± 10.6 and 51.9 ± 10.7 years in enhanced standard care and Yoga-CaRe group, respectively. At 12 weeks, Yoga-CaRe significantly reduced ADMA, ET-1, and ICMA-1 than the enhanced standard care group. Although E-selectin and VCAM at 12 weeks were reduced in both groups, enhanced standard care had a significantly higher reduction than the Yoga-CaRe group. Among markers of oxidative stress, TAOC increased in the Yoga-CaRe group. We found no difference in eNOS, NOx, P-selectin, TNFα, CRP, and Oxd-LDL between the two groups.

Conclusion

Yoga-CaRe improved the endothelial function (through a reduction in ET-1 and modulating adhesion molecules) and enhanced antioxidant capacity.

[Integrative assessment of the effectiveness and safety of outpatient use of Picamilon]

OBJECTIVE

To study the efficacy and safety of the use of the drug Picamilon with various therapy regimens in patients with stage I of chronic cerebral ischemia (CCI).

MATERIAL AND METHODS

Material and methods. An open randomized comparative clinical trial included 44 patients with stage CCI aged 46 to 67 years (average age 55.6±6.76 years). Patients were randomized into two groups, patients of group 1 (n=23) received Picamilon orally in tablets of 50 mg 3 times/day for 60 days; group 2 (n=21) received Picamilon first parenterally at 100 mg i/m for 10 days, then in tablets of 50 mg 3 times/day for 50 days. The total duration of therapy was 60 days. The study included 4 visits (before treatment, 10 days later, 60 days later, 1.5 months after completion of treatment). The dynamics of cognitive status were assessed according to the Montreal Cognitive Function Assessment Scale (MoCA), vegetative disorders on the A.M. Wayne scale, neurological disorders on the A.I. Fedin scale, and sleep quality on the Ya.I. Levin scale. The study of the state of cerebral blood flow (dopplerography of intracranial vessels) and endothelial function (assessment of the level of methylation.

RESULTS

During treatment, in the total sample of patients, there was a positive trend in the results of the MoCA scale, increasing in the delayed period (24.9/26.5/28.3 points, p=0.022 and p<0.001); improvement in sleep quality in 50% of patients by visit 3 and in 84% by visit 4, in the 2nd group the effect occurred in 28% of patients, in the 1st - in 11%, by the end of the study the effect was comparable (p=0.508). Improvement according to Fedin A.I. scale noted in 77% of patients, values decreased from 11.9±8.3 to 6±6.1 points (p<0.0001) and to 2.77±4.43 points by visit 4 (p<0.0001). Normalization of autonomic functions was observed in 29% of patients (p=0.024) without intergroup differences. Picamilon therapy showed high efficacy in terms of clinical outcomes (up to 89%), good tolerability (98% of patients) and a favorable safety profile (less than 8.6% of AEs). The use of Picamilon was accompanied by an increase in the linear velocity of blood flow, a decrease in the thickness of the intima-media complex and the resistance index; a decrease in elevated ADMA concentrations and ADMA/MMA and (ADMA+SDMA)/MMA ratios.

CONCLUSION

The use of Picamilon is effective in patients with stage I CCI, contributes to a significant regression of neurological deficits, cognitive impairment, improved sleep quality and autonomic function; improves vascular endothelial function, reduces the risk of atherosclerosis and cardiovascular complications in patients. The optimal duration of therapy with Picamilon in stage I of chronic cerebral ischemia is 2 months.

All That Glitters Is Not Gold: Assessment of Bee Pollen Supplementation Effects on Gastric Mucosa

The aim of this study was to assess the influence of bee pollen supplementation on the levels of enzymes important for gastric mucosal homeostasis, namely cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and a biomarker-asymmetric dimethylarginine (ADMA)-in the gastric mucosa of Wistar rats. The experimental phase divided the rats into four groups: two control groups, sedentary and active, both not supplemented, and two experimental groups, sedentary and active, supplemented with bee pollen. The results indicated that bee pollen supplementation reduced the levels of COX-1 and elevated iNOS levels, while showing no significant impact on COX-2 levels. These findings do not conclusively support the gastroprotective and anti-inflammatory effects of bee pollen on gastric mucosa. However, the supplementation could have resulted in reduced ADMA levels in the physically active supplemented group. Our study does not unequivocally demonstrate the positive effects of bee pollen supplementation on the gastric mucosa, which may be attributed to the specific metabolism and bioavailability of substances within unprocessed, dried bee pollen. Further research should explore the topic of potential therapeutic applications of bee pollen in gastrointestinal health and its interactions with ADMA signaling pathways.

Advances and Perspectives in Relation to the Molecular Basis of Diabetic Retinopathy-A Review

Diabetes mellitus (DM) is a growing problem nowadays, and diabetic retinopathy (DR) is its predominant complication. Currently, DR diagnosis primarily relies on fundoscopic examination; however, novel biomarkers may facilitate that process and make it widely available. In this current review, we delve into the intricate roles of various factors and mechanisms in DR development, progression, prediction, and their association with therapeutic approaches linked to the underlying pathogenic pathways. Specifically, we focus on advanced glycation end products, vascular endothelial growth factor (VEGF), asymmetric dimethylarginine, endothelin-1, and the epigenetic regulation mediated by microRNAs (miRNAs) in the context of DR.

Association between exposure to arsenic and the risk of cardiovascular disease: Potential role of vascular endothelial injury

In this study, we investigated the risk of cardiovascular disease (CVD) in individuals exposed to arsenic (As) and to identify potential biomarkers. The results revealed that the FRS was positively correlated with the MMA content and MMA% but negatively correlated with the DMA% and SMI, while the AIP index was positively correlated with the DMA, MMA, MMA%, iAs, tAs and As3+ content. In addition, ADMA was positively correlated with MMA and MMA% and negatively correlated with the SMI and DMA%. Regression models showed that ADMA and ICAM1 were positively correlated with CVD risk. Mediation analysis indicated that ADMA and ICAM1 mediated the association between As exposure and CVD risk. In conclusion, the risk of CVD is higher in residents previously exposed As. Endothelial injury appears to mediate the increased risk of As-induced CVD, and both ADMA and ICAM1 may serve as potential biomarkers for the early identification of this process.

Effects of olive oil and flaxseed consumption in a healthy diet on endothelial function, plasma lipids and inflammatory factors of patients with coronary heart disease: a randomized clinical trial

OBJECTIVES

A healthy lifestyle, including a healthy diet has been associated with an improvement in cardiovascular risk factors. The aim of the present study was to assess the effect of olive oil and flaxseed consumption as part of a healthy diet on endothelial function, plasma inflammatory factors, and lipid profile in patients with coronary heart disease (CHD).

METHOD

This randomized nonblinded trial was performed on CHD patients. In the control group, participants received general heart-healthy dietary recommendations while in the intervention group, in addition to these recommendations, the participants consumed 25 ml of olive oil and 30 g of flaxseeds daily for 3 months. At baseline and after 3 months, changes in brachial flow-mediated dilation (FMD), plasma asymmetric dimethyl arginine, interleukin-6 (IL-6), IL-10, high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), and lipids and lipoproteins were measured.

RESULTS

A total of 50 patients finished the trial ( n  = 24 in the intervention and n  = 26 in the control groups). Compared to the control group, consumption of flaxseed and olive oil significantly improved brachial artery FMD%, and reduced plasma IL-6, TNF-α, MCP-1, total cholesterol, and tended to reduce hs-CRP, and non-HDL-cholesterol but the concentration of other study indices were not different between the two groups.

CONCLUSION

Inclusion of olive oil and flaxseed in the diet of CHD patients may contribute to secondary prevention by improving endothelial function and plasma inflammatory factors.

Angiotensin Regulation of Vascular Homeostasis: Exploring the Role of ROS and RAS Blockers

Extensive research has been conducted to elucidate and substantiate the crucial role of the Renin-Angiotensin System (RAS) in the pathogenesis of hypertension, cardiovascular disorders, and renal diseases. Furthermore, the role of oxidative stress in maintaining vascular balance has been well established. It has been observed that many of the cellular effects induced by Angiotensin II (Ang II) are facilitated by reactive oxygen species (ROS) produced by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. In this paper, we present a comprehensive overview of the role of ROS in the physiology of human blood vessels, specifically focusing on its interaction with RAS. Moreover, we delve into the mechanisms by which clinical interventions targeting RAS influence redox signaling in the vascular wall.

Integrated NMR and MS Analysis of the Plasma Metabolome Reveals Major Changes in One-Carbon, Lipid, and Amino Acid Metabolism in Severe and Fatal Cases of COVID-19

Brazil has the second-highest COVID-19 death rate worldwide, and Rio de Janeiro is among the states with the highest rate in the country. Although vaccine coverage has been achieved, it is anticipated that COVID-19 will transition into an endemic disease. It is concerning that the molecular mechanisms underlying clinical evolution from mild to severe disease, as well as the mechanisms leading to long COVID-19, are not yet fully understood. NMR and MS-based metabolomics were used to identify metabolites associated with COVID-19 pathophysiology and disease outcome. Severe COVID-19 cases (n = 35) were enrolled in two reference centers in Rio de Janeiro within 72 h of ICU admission, alongside 12 non-infected control subjects. COVID-19 patients were grouped into survivors (n = 18) and non-survivors (n = 17). Choline-related metabolites, serine, glycine, and betaine, were reduced in severe COVID-19, indicating dysregulation in methyl donors. Non-survivors had higher levels of creatine/creatinine, 4-hydroxyproline, gluconic acid, and N-acetylserine, indicating liver and kidney dysfunction. Several changes were greater in women; thus, patients' sex should be considered in pandemic surveillance to achieve better disease stratification and improve outcomes. These metabolic alterations may be useful to monitor organ (dys) function and to understand the pathophysiology of acute and possibly post-acute COVID-19 syndromes.

New potential biomarkers for early chronic kidney disease diagnosis in patients with different glucose tolerance status

Background

The purpose of the present study was to investigate the role of oxidative stress, platelet activation, and endocan levels in renal dysfunction in normal glucose tolerance (NGT) patients with 1-h plasma glucose values ≥155 mg/dl (NGT ≥ 155), compared to NGT < 155, impaired glucose tolerance (IGT), and type 2 diabetes mellitus (T2DM) newly diagnosed subjects. We enlisted 233 patients subjected to an oral glucose tolerance test (OGTT).

Materials and methods

The serum levels of platelet activation (glycoprotein VI and sP-selectin), oxidative stress biomarkers (8-isoprostane and Nox-2), and endocan were evaluated using an ELISA test.

Results

Among NGT < 155 patients and the T2DM group, there was a statistically significant increase in 8-isoprostane (p < 0.0001), Nox-2 (p < 0.0001), glycoprotein VI (p < 0.0001), and sP-selectin (p < 0.0001) serum levels. Higher serum endocan levels were found with the worsening of metabolic profile (p < 0.0001); specifically, NGT ≥ 155 patients presented higher serum endocan values when compared to NGT < 155 patients (p < 0.0001). From the multivariate linear regression analysis, 1-h glucose resulted in the major predictor of estimated glomerular filtration rate (e-GFR) justifying 23.6% of its variation (p < 0.0001); 8-isoprostane and Nox-2 added respectively another 6.0% (p < 0.0001) and 3.2% (p = 0.001).

Conclusion

Our study confirmed the link between 1-h post-load glucose ≥155 mg/dl during OGTT and the possible increased risk for chronic kidney disease (CKD) in newly diagnosed patients. The novelty is that we demonstrated a progressive increase in oxidative stress, platelet activation, and serum endocan levels with the worsening of metabolic profile, which becomes evident early during the progression of CKD.

The effects of melatonin against atherosclerosis-induced endothelial dysfunction and inflammation in hypercholesterolemic rats

The aim of this study was to investigate the effects of melatonin on the serum asymmetric dimethylarginine (ADMA) levels and the expressions of vaspin, visfatin, dimethylarginine dimethylaminohydrolase (DDAH), and signal transducer and activator of transcription-3 (STAT-3) for evaluation of endothelial function and inflammation in the hypercholesterolemic rats. Rats were divided into 5 groups: (1) control, (2) hypercholesterolaemia, (3) melatonin administrated concurrently with cholesterol diet, (4) melatonin administrated only last 2 weeks and fed with cholesterol diet, (5) atorvastatin administered only last 2 weeks fed with cholesterol diet. Although an increase was observed in the expressions of visfatin and STAT-3 and the serum ADMA levels, the vaspin and DDAH protein expressions were found to decrease with hypercholesterolemic diets. Melatonin was determined to restore all the parameters to the normal levels. In conclusion, melatonin may have protective and therapeutic effects on hypercholesterolaemia by regulating vaspin, STAT-3, DDAH, and ADMA signalling pathways and create similar effects with atorvastatin.

microRNAs as Biomarkers of Endothelial Dysfunction and Therapeutic Target in the Pathogenesis of Atrial Fibrillation

The pathophysiology of atrial fibrillation (AF) may involve atrial fibrosis/remodeling and dysfunctional endothelial activities. Despite the currently available treatment approaches, the progression of AF, its recurrence rate, and the high mortality risk of related complications underlay the need for more advanced prognostic and therapeutic strategies. There is increasing attention on the molecular mechanisms controlling AF onset and progression points to the complex cell to cell interplay that triggers fibroblasts, immune cells and myofibroblasts, enhancing atrial fibrosis. In this scenario, endothelial cell dysfunction (ED) might play an unexpected but significant role. microRNAs (miRNAs) regulate gene expression at the post-transcriptional level. In the cardiovascular compartment, both free circulating and exosomal miRNAs entail the control of plaque formation, lipid metabolism, inflammation and angiogenesis, cardiomyocyte growth and contractility, and even the maintenance of cardiac rhythm. Abnormal miRNAs levels may indicate the activation state of circulating cells, and thus represent a specific read-out of cardiac tissue changes. Although several unresolved questions still limit their clinical use, the ease of accessibility in biofluids and their prognostic and diagnostic properties make them novel and attractive biomarker candidates in AF. This article summarizes the most recent features of AF associated with miRNAs and relates them to potentially underlying mechanisms.

Endothelial dysfunction due to eNOS uncoupling: molecular mechanisms as potential therapeutic targets

Nitric oxide (NO) is one of the most important molecules released by endothelial cells, and its antiatherogenic properties support cardiovascular homeostasis. Diminished NO bioavailability is a common hallmark of endothelial dysfunction underlying the pathogenesis of the cardiovascular disease. Vascular NO is synthesized by endothelial nitric oxide synthase (eNOS) from the substrate L-arginine (L-Arg), with tetrahydrobiopterin (BH₄) as an essential cofactor. Cardiovascular risk factors such as diabetes, dyslipidemia, hypertension, aging, or smoking increase vascular oxidative stress that strongly affects eNOS activity and leads to eNOS uncoupling. Uncoupled eNOS produces superoxide anion (O₂^-) instead of NO, thus becoming a source of harmful free radicals exacerbating the oxidative stress further. eNOS uncoupling is thought to be one of the major underlying causes of endothelial dysfunction observed in the pathogenesis of vascular diseases. Here, we discuss the main mechanisms of eNOS uncoupling, including oxidative depletion of the critical eNOS cofactor BH₄, deficiency of eNOS substrate L-Arg, or accumulation of its analog asymmetrical dimethylarginine (ADMA), and eNOS S-glutathionylation. Moreover, potential therapeutic approaches that prevent eNOS uncoupling by improving cofactor availability, restoration of L-Arg/ADMA ratio, or modulation of eNOS S-glutathionylation are briefly outlined.

The Relationship of Left Ventricular Diastolic Dysfunction and Asymmetrical Dimethylarginine as a Biomarker of Endothelial Dysfunction with Cardiovascular Risk Assessed by Systematic Coronary Risk Evaluation2 Algorithm and Heart Failure-A Cross-Sectional Study

Background: Cardiovascular (CV) risk factors, causing endothelial dysfunction (ED) and left ventricular diastolic dysfunction (LVDD), contribute to an increased risk of heart failure (HF). The aim of this study was to determine the relationship between the occurrence of LVDD and ED with CV risk assessed by the Systematic Coronary Risk Evaluation2 (SCORE2) algorithm and HF. Methods: In the period from November 2019 to May 2022, a cross-sectional study that included 178 middle-aged adults was conducted. Transthoracic echocardiography (TTE) was used to assess left ventricular (LV) diastolic and systolic function. ED was assessed using the plasma values of asymmetric dimethylarginine (ADMA) and was determined using the ELISA method. Results: The majority of subjects with LVDD grades 2 and 3 had high/very high SCORE2, developed HF and all were taking medication (p < 0.001). They also had significantly lowest plasma ADMA values (p < 0.001). We found that the reduction of ADMA concentration is influenced by certain groups of drugs, or more significantly, by their combinations (p < 0.001). Conclusions: In our study, we confirmed a positive correlation between LVDD, HF and SCORE2 severity. The results showed a negative correlation between the biomarkers of ED, LVDD severity, HF, and SCORE2, which we believe is due to medication effects.

Health outcomes of 100% orange juice and orange flavored beverage: A comparative analysis of gut microbiota and metabolomics in rats

A high intake of sugar-sweetened fruity beverage (FB) is associated with a higher risk of metabolic syndromes, but the health outcome of 100% fruit juice (FJ) intake remains unclear. We aim to reveal health outcomes of diet intervention (FJ or FB) with system profiling via interaction of gut microbiota and metabolomics in a rat (Rattus norvegicus) model. Firstly, the glucose, sucrose, fructose, and bioactive metabolites of FJ and FB were analyzed, and FJ possessed higher sucrose and flavonoids, while FB showed higher glucose and fructose. Secondly, C0 was set as the control group on Day 0, and a 4-week diet invention was performed to control, FJ-intake, and FB-intake groups with normal saline, FJ, and FB, respectively. The results showed that FJ improved alpha diversity and decreased the Firmicutes/Bacteroidota ratio (F/B ratio) of gut microbiota and prevented insulin resistance. However, FB possessed unchanged microbial diversity and enhanced F/B ratio, causing insulin resistance with renal triglyceride accumulation. In summary, FJ, although naturally containing similar amounts of total free sugars as FB, could be a healthier drink choice.

Correlation between lipid-lowering therapy and cerebral microbleeds

OBJECTIVE

To investigate if there is a correlation between lipid-lowering treatment with statins and the occurrence, number, and location of cerebral microbleeds (CMBs) among patients with ischemic cerebrovascular disease (ICVD), and also to compare treatment with atorvastatin and rosuvastatin in terms of the occurrence of CMBs and their differences.

METHODS

In this retrospective study, we included patients who were diagnosed with ICVD and underwent susceptibility weighted imaging (SWI) in a grade A tertiary hospital from October 1, 2014 to October 1, 2022. We collected information on previous statin use, past medical history, clinical test indicators, and imaging data.

RESULTS

We found that out of 522 patients, 310 patients (59.4%) had no CMB and 212 patients (40.6%) had CMBs. There was no statistically significant correlation between prior statin use, the occurrence, and number of CMBs in patients diagnosed with ICVD (P < 0.05). As for the location of CMB, there was a statistically significant correlation between prior statin use and lobar CMBs (P < 0.048). However, there was no statistically significant correlation between the use of atorvastatin and rosuvastatin and the occurrence of CMBs (P > 0.05).

CONCLUSION

There was no independent correlation between previous statin use, and the occurrence, and number of CMBs in patients with ICVD. As for CMBs in different locations, there was a correlation between previous use of statin and lobar CMBs. There was no significant difference between atorvastatin and rosuvastatin in the occurrence of CMBs in patients with ICVD.

Role of ADMA in the pathogenesis of microvascular complications in type 2 diabetes mellitus

Diabetic microangiopathy is a typical and severe problem in diabetics, including diabetic retinopathy, diabetic nephropathy, diabetic neuropathy, and diabetic cardiomyopathy. Patients with type 2 diabetes and diabetic microvascular complications have significantly elevated levels of Asymmetric dimethylarginine (ADMA), which is an endogenous inhibitor of nitric oxide synthase (NOS). ADMA facilitates the occurrence and progression of microvascular complications in type 2 diabetes through its effects on endothelial cell function, oxidative stress damage, inflammation, and fibrosis. This paper reviews the association between ADMA and microvascular complications of diabetes and elucidates the underlying mechanisms by which ADMA contributes to these complications. It provides a new idea and method for the prevention and treatment of microvascular complications in type 2 diabetes.

Homoarginine in the cardiovascular system: Pathophysiology and recent developments

Upcoming experimental and epidemiological data have identified the endogenous non-proteinogenic amino acid L-homoarginine (L-hArg) not only as a novel biomarker for cardiovascular disease but also as being directly involved in the pathogenesis of cardiac dysfunction. The association of low L-hArg levels with adverse cardiovascular events and mortality has proposed the idea of nutritional supplementation to rescue pathways inversely associated with cardiovascular health. Subsequent clinical and experimental studies contributed significantly to our knowledge of potential effects on the cardiorenal axis, acting either as a biomarker or a cardiovascular active agent. In this review article, we provide a comprehensive summary of the L-hArg metabolism, pathophysiological aspects, and current developments in the field of experimental and clinical evidence in favor of protective cardiovascular effects. Establishing a reliable biomarker to identify patients at high risk to die of cardiovascular disease represents one of the main goals for tackling this disease and providing individual therapeutic guidance.

Targeting hydrogen sulfide and nitric oxide to repair cardiovascular injury after trauma

The systemic cardiovascular effects of major trauma, especially neurotrauma, contribute to death and permanent disability in trauma patients and treatments are needed to improve outcomes. In some trauma patients, dysfunction of the autonomic nervous system produces a state of adrenergic overstimulation, causing either a sustained elevation in catecholamines (sympathetic storm) or oscillating bursts of paroxysmal sympathetic hyperactivity. Trauma can also activate innate immune responses that release cytokines and damage-associated molecular patterns into the circulation. This combination of altered autonomic nervous system function and widespread systemic inflammation produces secondary cardiovascular injury, including hypertension, damage to cardiac tissue, vascular endothelial dysfunction, coagulopathy and multiorgan failure. The gasotransmitters nitric oxide (NO) and hydrogen sulfide (H2S) are small gaseous molecules with potent effects on vascular tone regulation. Exogenous NO (inhaled) has potential therapeutic benefit in cardio-cerebrovascular diseases, but limited data suggests potential efficacy in traumatic brain injury (TBI). H2S is a modulator of NO signaling and autonomic nervous system function that has also been used as a drug for cardio-cerebrovascular diseases. The inhaled gases NO and H2S are potential treatments to restore cardio-cerebrovascular function in the post-trauma period.

Asymmetric dimethylarginine and gestational diabetes mellitus: a systematic review and meta-analysis

PURPOSE

Emerging evidence demonstrates that asymmetric dimethylarginine (ADMA) levels are elevated in patients with or at risk of cardiovascular disease (CVD). Since women with gestational diabetes mellitus (GDM) are at high risk of future CVD, we conducted a systematic review and meta-analysis to compare ADMA concentrations between women with and without GDM during pregnancy and postpartum.

METHODS

PubMed, Google Scholar, EMBASE, and CINAHL databases were searched. The review protocol is registered in PROSPERO (CRD42021276796). Study selection, data extraction, and data analyses were performed in accordance with PRISMA guidelines. Random-effects model was used to quantify ADMA levels in the study groups.

RESULTS

Eleven studies provided data on 1148 women. Mean plasma ADMA concentration was 0.04 μmol/L (95% confidence interval (CI) -0.06-0.15) higher in pregnant women with GDM than those without GDM, but no significant difference was observed. In contrast, our meta-analysis demonstrated a significant increase in postpartum mean ADMA concentration (Mean Difference (MD) 0.11 μmol/L; 95% CI 0.05-0.16) among women with previous GDM compared to women without previous GDM.

CONCLUSION

Elevated ADMA levels in GDM may be a CVD risk factor, suggesting that ADMA may be a potential biomarker for early CVD risk prediction in women with GDM.

Tumor cell-derived asymmetric dimethylarginine regulates macrophage functions and polarization

BACKGROUND

Asymmetric dimethylarginine (ADMA), which is significantly elevated in the plasma of cancer patients, is formed via intracellular recycling of methylated proteins and serves as a precursor for resynthesis of arginine. However, the cause of ADMA elevation in cancers and its impact on the regulation of tumor immunity is not known.

METHODS

Three mouse breast cell lines (normal breast epithelial HC11, breast cancer EMT6 and triple negative breast cancer 4T1) and their equivalent 3D stem cell culture were used to analyze the secretion of ADMA using ELISA and their responses to ADMA. Bone marrow-derived macrophages and/or RAW264.7 cells were used to determine the impact of increased extracellular ADMA on macrophage-tumor interactions. Gene/protein expression was analyzed through RNAseq, qPCR and flow cytometry. Protein functional analyses were conducted via fluorescent imaging (arginine uptake, tumor phagocytosis) and enzymatic assay (arginase activity). Cell viability was measured via MTS assay and/or direct cell counting using Countess III FL system.

RESULTS

For macrophages, ADMA impaired proliferation and phagocytosis of tumor cells, and even caused death in cultures incubated without arginine. ADMA also led to an unusual macrophage phenotype, with increased expression of arginase, cd163 and cd206 but decreased expression of il10 and dectin-1. In contrast to the severely negative impacts on macrophages, ADMA had relatively minor effects on proliferation and survival of mouse normal epithelial HC11 cells, mouse breast cancer EMT6 and 4T1 cells, but there was increased expression of the mesenchymal markers, vimentin and snail2, and decreased expression of the epithelial marker, mucin-1 in EMT6 cells. When tumor cells were co-cultured ex vivo with tumor antigen in vivo-primed splenocytes, the tumor cells secreted more ADMA and there were alterations in the tumor cell arginine metabolic landscape, including increased expression of genes involved in arginine uptake, metabolism and methylation, and decreased expression of a gene that is responsible for arginine demethylation. Additionally, interferon-gamma, a cytokine involved in immune challenge, increased secretion of ADMA in tumor cells, a process attenuated by an autophagy inhibitor.

CONCLUSION

Our results suggest initial immune attack promotes autophagy in tumor cells, which then secrete ADMA to manipulate macrophage polarization favoring tumor tolerance.