S-adenosyl methionine prevents endothelial dysfunction by inducing heme oxygenase-1 in vascular endothelial cells

S-Adenosylmethionine (SAMe) for Central Nervous System Health: A Systematic Review

Background/Objectives: S-adenosylmethionine (SAMe) is a natural compound used to improve mood-related symptoms. Our aim was to determine the efficacy, safety, and optimal dose of SAMe in Central Nervous System (CNS) signs (e.g., mood, behavior). Methods: We conducted a PRISMA-based systematic review by searching PubMed, CINAHL, and Web of Science using MeSH search terms. Articles were independently reviewed by two researchers (with a third resolving conflicts) during title/abstract screening and full-text review. Data were extracted in the same approach, with a quality assessment of included articles. Results: Out of 1881 non-duplicated studies, 36 were included in the review focusing on CNS signs (mood, behavior, sleep). Most studies (n = 32) achieved a 4 or 5 out of 5 points, indicating high study quality. Overall, SAMe was effective in 24 of 36 studies, with adverse events mostly consisting of mild, transient gastrointestinal disturbances. Conclusions: Many patients in these studies did experience improvements in CNS signs from using SAMe alone or in combination with existing therapy. However, future studies are needed to further understand the long-term effects of SAMe in the CNS.

S-adenosyl-L-methionine supplementation alleviates aortic dissection by decreasing inflammatory infiltration

Methionine, an indispensable amino acid crucial for dietary balance, intricately governs metabolic pathways. Disruption in its equilibrium has the potential to heighten homocysteine levels in both plasma and tissues, posing a conceivable risk of inducing inflammation and detriment to the integrity of vascular endothelial cells. The intricate interplay between methionine metabolism, with a specific focus on S-adenosyl-L-methionine (SAM), and the onset of thoracic aortic dissection (TAD) remains enigmatic despite acknowledging the pivotal role of inflammation in this vascular condition. In an established murine model induced by β-aminopropionitrile monofumarate (BAPN), we delved into the repercussions of supplementing with S-adenosyl-L-methionine (SAM) on the progression of TAD. Our observations uncovered a noteworthy improvement in aortic dissection and rupture rates, accompanied by a marked reduction in mortality upon SAM supplementation. Notably, SAM supplementation exhibited a considerable protective effect against BAPN-induced degradation of elastin and the extracellular matrix. Furthermore, SAM supplementation demonstrated a robust inhibitory influence on the infiltration of immune cells, particularly neutrophils and macrophages. It also manifested a notable reduction in the inflammatory polarization of macrophages, evident through diminished accumulation of MHC-IIhigh macrophages and reduced expression of inflammatory cytokines such as IL1β and TNFα in macrophages. Simultaneously, SAM supplementation exerted a suppressive effect on the activation of CD4 + and CD8 + T cells within the aorta. This was evidenced by an elevated proportion of CD44- CD62L + naïve T cells and a concurrent decrease in CD44 + CD62L- effector T cells. In summary, our findings strongly suggest that the supplementation of SAM exhibits remarkable efficacy in alleviating BAPN-induced aortic inflammation, consequently impeding the progression of thoracic aortic dissection.

Plasma metabolomics identifies S-adenosylmethionine as a biomarker and potential therapeutic target for vascular aging in older adult males

Brachial-ankle pulse wave velocity (baPWV) is a noninvasive index of vascular aging. However, the metabolic profile underlying vascular aging has not yet been fully elucidated. The current study aimed to identify circulating markers of vascular aging as assessed by baPWV and to elucidate its mechanism from a metabolomic perspective in older adults. A total of 60 and 61 Chinese male participants aged ≥80 years were recruited to the metabolome and validation cohorts, respectively. The baPWV of participants was measured using an automatic waveform analyzer. Plasma metabolic profile was investigated using ultra-performance liquid chromatography coupled with triple quadrupole linear ion trap tandem mass spectrometry. Orthogonal partial least squares (OPLS) regression modeling established the association between metabolic profile and baPWV to determine important metabolites predictive of vascular aging. Additionally, an enzyme-linked immunosorbent assay was employed to validate the metabolites in plasma and culture media of vascular smooth muscle cells in vitro. OPLS modeling identified 14 and 22 metabolites inversely and positively associated with baPWV, respectively. These 36 biomarkers were significantly enriched in seven metabolite sets, especially in cysteine and methionine metabolism (p <0.05). Notably, among metabolites involved in cysteine and methionine metabolism, S-adenosylmethionine (SAM) level was inversely related to baPWV, with a significant correlation coefficient in the OPLS model (p <0.05). Furthermore, the relationship between SAM and vascular aging was reconfirmed in an independent cohort and at the cellular level in vitro. SAM was independently associated with baPWV after adjustments for clinical covariates (β = -0.448, p <0.001) in the validation cohort. In summary, plasma metabolomics identified an inverse correlation between SAM and baPWV in older males. SAM has the potential to be a novel biomarker and therapeutic target for vascular aging.

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

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

Betaine Supplementation Attenuates S-Adenosylhomocysteine Hydrolase-Deficiency-Accelerated Atherosclerosis in Apolipoprotein E-Deficient Mice

S-adenosylhomocysteine (SAH) is a risk factor of cardiovascular diseases and atherosclerosis. However, the causal association between SAH and atherosclerosis is still uncertain. In the present study, heterozygous SAH hydrolase (SAHH^+/−) knockout mice were bred with apolipoprotein E-deficient mice to produce ApoE^−/−/SAHH^+/− mice. At 8 weeks of age, these mice were fed on AIN-93G diets added with or without betaine (4 g betaine/100 g diet) for 8 weeks. Compared with ApoE^−/−/SAHH^WT mice, SAHH deficiency caused an accumulation of plasma SAH concentration and a decrease in S-adenosylmethionine (SAM)/SAH ratio as well as plasma homocysteine levels. Betaine supplementation lowered SAH levels and increased SAM/SAH ratio and homocysteine levels in ApoE^−/−/SAHH^+/− mice. Furthermore, SAHH deficiency promoted the development of atherosclerosis, which was reduced by betaine supplementation. The atheroprotective effects of betaine on SAHH-deficiency-promoted atherosclerosis were associated with inhibition of NFκB inflammation signaling pathway and inhibition of proliferation and migration of smooth muscle cells. In conclusion, our results suggest that betaine supplementation lowered plasma SAH levels and protected against SAHH-deficiency-promoted atherosclerosis through repressing inflammation and proliferation and migration of smooth muscle cells.

Epigenetics: key to improve delayed wound healing in type 2 diabetes

Diabetes-related delayed wound healing is a multifactorial, nuanced, and intertwined complication that causes substantial clinical morbidity. The etiology of diabetes and its related microvascular complications is affected by genes, diet, and lifestyle factors. Epigenetic modifications such as DNA methylation, histone modifications, and post-transcriptional RNA regulation (microRNAs) are subsequently recognized as key facilitators of the complicated interaction between genes and the environment. Current research suggests that diabetes-persuaded dysfunction of epigenetic pathways, which results in changed expression of genes in target cells and cause diabetes-related complications including cardiomyopathy, nephropathy, retinopathy, delayed wound healing, etc., which are foremost drivers to diabetes-related adverse outcomes. In this paper, we discuss the role of epigenetic mechanisms in controlling tissue repair, angiogenesis, and expression of growth factors, as well as recent findings that show the alteration of epigenetic events during diabetic wound healing.

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Heme Oxygenase 1: A Defensive Mediator in Kidney Diseases

The incidence of kidney disease is rising, constituting a significant burden on the healthcare system and making identification of new therapeutic targets increasingly urgent. The heme oxygenase (HO) system performs an important function in the regulation of oxidative stress and inflammation and, via these mechanisms, is thought to play a role in the prevention of non-specific injuries following acute renal failure or resulting from chronic kidney disease. The expression of HO-1 is strongly inducible by a wide range of stimuli in the kidney, consequent to the kidney's filtration role which means HO-1 is exposed to a wide range of endogenous and exogenous molecules, and it has been shown to be protective in a variety of nephropathological animal models. Interestingly, the positive effect of HO-1 occurs in both hemolysis- and rhabdomyolysis-dominated diseases, where the kidney is extensively exposed to heme (a major HO-1 inducer), as well as in non-heme-dependent diseases such as hypertension, diabetic nephropathy or progression to end-stage renal disease. This highlights the complexity of HO-1's functions, which is also illustrated by the fact that, despite the abundance of preclinical data, no drug targeting HO-1 has so far been translated into clinical use. The objective of this review is to assess current knowledge relating HO-1's role in the kidney and its potential interest as a nephroprotection agent. The potential therapeutic openings will be presented, in particular through the identification of clinical trials targeting this enzyme or its products.

Pharmacological correction of endothelial dysfunction using ademethionin and taurine

Introduction: Рharmacological correction of endothelial dysfunction is a urgent problem of modern medicine.

Materials and methods: Endothelial dysfunction was simulated in male rats using the e-NOS inhibitor L-NAME (25 mg/kg/day intraperitoneally, for 7 days). Simulation of ADMA-like preeclampsia was performed by intraperitoneal injection of L-NAME to females in the same doses for 7 days (14-20th days of pregnancy). These pathologies were corrected by administering ademethionine in dose 150 mg/kg and taurine at a dose of 260 mg/kg, as well as their combination at the same doses, intragastrically, through an atraumatic probe, once a day.

Results: In the group with use of taurine at a dose of 260 mg/kg the coefficient of endothelial dysfunction decreased to the level of intact animals. Use of ademethionine at a dose of 150 mg/kg and taurine at a dose of 260 mg/kg combined resulted in the most pronounced endothelioprotective effect on the ADMA-like preeclampsia model. The coefficient of endothelial dysfunction decreased more than when using monotherapy of these drugs. Morphological studies of myocardiocytes showed that the combination of ademethionine at a dose of 150 mg/kg and taurine at a dose of 260 mg/kg prevented an increase in the cross-section of cardiomyocytes.

Discussion: Possibly, ademethionine and taurine have an endothelioprotective effect because of their ability to decrease hyperhomocysteinemia.

Conclusion: The investigated drugs showed pronounced endothelioprotective activity and can be recommended for further pre-clinical studies.

Epigenetic Modification of MicroRNA-200b Contributes to Diabetic Vasculopathy

Hyperglycemia (HG) induces genome-wide cytosine demethylation. Our previous work recognized miR-200b as a critical angiomiR, which must be transiently downregulated to initiate wound angiogenesis. Under HG, miR-200b downregulation is not responsive to injury. Here, we demonstrate that HG may drive vasculopathy by epigenetic modification of a miR promoter. In human microvascular endothelial cells (HMECs), HG also lowered DNA methyltransferases (DNMT-1 and DNMT-3A) and compromised endothelial function as manifested by diminished endothelial nitric oxide (eNOS), lowered LDL uptake, impaired Matrigel tube formation, lower NO production, and compromised VE-cadherin expression. Bisulfite-sequencing documented HG-induced miR-200b promoter hypomethylation in HMECs and diabetic wound-site endothelial cells. In HMECs, HG compromised endothelial function. Methyl donor S-adenosyl-L-methionine (SAM) corrected miR-200b promoter hypomethylaton and rescued endothelial function. In vivo, wound-site administration of SAM to diabetic mice improved wound perfusion by limiting the pathogenic rise of miR-200b. Quantitative stable isotope labeling by amino acids in cell culture (SILAC) proteomics and ingenuity pathway analysis identified HG-induced proteins and principal clusters in HMECs sensitive to the genetic inhibition of miR-200b. This work presents the first evidence of the miR-200b promoter methylation as a critical determinant of diabetic wound angiogenesis.