S-adenosylhomocysteine induces inflammation through NFkB: A possible role for EZH2 in endothelial cell activation

Zedoarondiol inhibits monocyte adhesion and expression of VCAM and ICAM in endothelial cells induced by oxidative stress

Zedoarondiol, a newly discovered compound derived from the roots of zedoary turmeric, a traditional Chinese herb, has demonstrated potential in reducing inflammation of the vascular endothelium and safeguarding it from harm. Nonetheless, the precise mechanism underlying these effects remains to be elucidated. In this study, we established a model of HUVEC injury induced by hydrogen peroxide. We observed whether Zedoarondiol could reduce the adhesion and transendothelial migration (TEM) of inflammatory cells by inhibiting the expression of VCAM-1 and ICAM-1 in HUVECs. The research findings indicate that utilising Zedoarondiol resulted in a significant reduction in the adhesion rate of THP1 cells to HUVECs, leading to a more condensed cytoskeletal structure. Moreover, Zedoarondiol demonstrated a decrease in NF-κBβ-Ser536 phosphorylation levels in H2O2-stimulated human umbilical vein endothelial cells, resulting in a hindered capacity to bind to target genes like ICAM-1 and VCAM-1, This findings may provide a new pharmacological basis and scientific evidence for Zedoarondiol to slow the atherosclerosis progression by maintaining endothelial function.

Epidrugs in the clinical management of atherosclerosis: Mechanisms, challenges and promises

Atherosclerosis is a complex and multigenic pathology associated with significant epigenetic reprogramming. Traditional factors (age, sex, obesity, hyperglycaemia, dyslipidaemia, hypertension) and non-traditional factors (foetal indices, microbiome alteration, clonal hematopoiesis, air pollution, sleep disorders) induce endothelial dysfunction, resulting in reduced vascular tone and increased vascular permeability, inflammation and shear stress. These factors induce paracrine and autocrine interactions between several cell types, including vascular smooth muscle cells, endothelial cells, monocytes/macrophages, dendritic cells and T cells. Such cellular interactions lead to tissue-specific epigenetic reprogramming regulated by DNA methylation, histone modifications and microRNAs, which manifests in atherosclerosis. Our review outlines epigenetic signatures during atherosclerosis, which are viewed as potential clinical biomarkers that may be adopted as new therapeutic targets. Additionally, we emphasize epigenetic modifiers referred to as 'epidrugs' as potential therapeutic molecules to correct gene expression patterns and restore vascular homeostasis during atherosclerosis. Further, we suggest nanomedicine-based strategies involving the use of epidrugs, which may selectively target cells in the atherosclerotic microenvironment and reduce off-target effects.

SARS-CoV-2 NSP14 MTase activity is critical for inducing canonical NF-κB activation

Upon SARS-CoV-2 infection, patients with severe forms of COVID-19 often suffer from a dysregulated immune response and hyperinflammation. Aberrant expression of cytokines and chemokines is associated with strong activation of the immunoregulatory transcription factor NF-κB, which can be directly induced by the SARS-CoV-2 protein NSP14. Here, we use NSP14 mutants and generated cells with host factor knockouts (KOs) in the NF-κB signaling pathways to characterize the molecular mechanism of NSP14-induced NF-κB activation. We demonstrate that full-length NSP14 requires methyltransferase (MTase) activity to drive NF-κB induction. NSP14 WT, but not an MTase-defective mutant, is poorly expressed and inherent post-translational instability is mediated by proteasomal degradation. Binding of SARS-CoV-2 NSP10 or addition of the co-factor S-adenosylmethionine (SAM) stabilizes NSP14 and augments its potential to activate NF-κB. Using CRISPR/Cas9-engineered KO cells, we demonstrate that NSP14 stimulation of canonical NF-κB activation relies on NF-κB factor p65/RELA downstream of the NEMO/IKK complex, while c-Rel or non-canonical RelB are not required to induce NF-κB transcriptional activity. However, NSP14 overexpression is unable to induce canonical IκB kinase β (IKKβ)/NF-κB signaling and in co-immunoprecipitation assays we do not detect stable associations between NSP14 and NEMO or p65, suggesting that NSP14 activates NF-κB indirectly through its methyltransferase activity. Taken together, our data provide a framework how NSP14 can augment basal NF-κB activation, which may enhance cytokine expression in SARS-CoV-2 infected cells.

Accumulation of endogenous adenosine improves cardiomyocyte metabolism via epigenetic reprogramming in an ischemia-reperfusion model

Adenosine kinase (ADK) plays the major role in cardiac adenosine metabolism, so that inhibition of ADK increases myocardial adenosine levels. While the cardioprotective actions of extracellular adenosine against ischemia/reperfusion (I/R) are well-established, the role of cellular adenosine in protection against I/R remains unknown. Here we investigated the role of cellular adenosine in epigenetic regulation on cardiomyocyte gene expression, glucose metabolism and tolerance to I/R. Evans blue/TTC staining and echocardiography were used to assess the extent of I/R injury in mice. Glucose metabolism was evaluated by positron emission tomography and computed tomography (PET/CT). Methylated DNA immunoprecipitation (MeDIP) and bisulfite sequencing PCR (BSP) were used to evaluate DNA methylation. Lentiviral/adenovirus transduction was used to overexpress DNMT1, and the OSI-906 was administered to inhibit IGF-1. Cardiomyocyte-specific ADK/IGF-1-knockout mice were used for mechanistic experiments.Cardiomyocyte-specific ADK knockout enhanced glucose metabolism and ameliorated myocardial I/R injury in vivo. Mechanistically, ADK deletion caused cellular adenosine accumulation, decreased DNA methyltransferase 1 (DNMT1) expression and caused hypomethylation of multiple metabolic genes, including insulin growth factor 1 (IGF-1). DNMT1 overexpression abrogated these beneficial effects by enhancing apoptosis and decreasing IGF-1 expression. Inhibition of IGF-1 signaling with OSI-906 or genetic knocking down of IGF-1 also abrogated the cardioprotective effects of ADK knockout, revealing the therapeutic potential of increasing IGF-1 expression in attenuating myocardial I/R injury. In conclusion, the present study demonstrated that cardiomyocyte ADK deletion ameliorates myocardial I/R injury via epigenetic upregulation of IGF-1 expression via the cardiomyocyte adenosine/DNMT1/IGF-1 axis.

Identification of methylation-regulated genes modulating microglial phagocytosis in hyperhomocysteinemia-exacerbated Alzheimer's disease

BACKGROUND

Hyperhomocysteinemia (HHcy) has been linked to development of Alzheimer's disease (AD) neuropathologically characterized by the accumulation of amyloid β (Aβ). Microglia (MG) play a crucial role in uptake of Aβ fibrils, and its dysfunction worsens AD. However, the effect of HHcy on MG Aβ phagocytosis remains unstudied.

METHODS

We isolated MG from the cerebrum of HHcy mice with genetic cystathionine-β-synthase deficiency (Cbs-/-) and performed bulk RNA-seq. We performed meta-analysis over transcriptomes of Cbs-/- mouse MG, human and mouse AD MG, MG Aβ phagocytosis model, human AD methylome, and GWAS AD genes.

RESULTS

HHcy and hypomethylation conditions were identified in Cbs-/- mice. Through Cbs-/- MG transcriptome analysis, 353 MG DEGs were identified. Phagosome formation and integrin signaling pathways were found suppressed in Cbs-/- MG. By analyzing MG transcriptomes from 4 AD patient and 7 mouse AD datasets, 409 human and 777 mouse AD MG DEGs were identified, of which 37 were found common in both species. Through further combinatory analysis with transcriptome from MG Aβ phagocytosis model, we identified 130 functional-validated Aβ phagocytic AD MG DEGs (20 in human AD, 110 in mouse AD), which reflected a compensatory activation of Aβ phagocytosis. Interestingly, we identified 14 human Aβ phagocytic AD MG DEGs which represented impaired MG Aβ phagocytosis in human AD. Finally, through a cascade of meta-analysis of transcriptome of AD MG, functional phagocytosis, HHcy MG, and human AD brain methylome dataset, we identified 5 HHcy-suppressed phagocytic AD MG DEGs (Flt1, Calponin 3, Igf1, Cacna2d4, and Celsr) which were reported to regulate MG/MΦ migration and Aβ phagocytosis.

CONCLUSIONS

We established molecular signatures for a compensatory response of Aβ phagocytosis activation in human and mouse AD MG and impaired Aβ phagocytosis in human AD MG. Our discoveries suggested that hypomethylation may modulate HHcy-suppressed MG Aβ phagocytosis in AD.

Epigenetic modulation of Drp1-mediated mitochondrial fission by inhibition of S-adenosylhomocysteine hydrolase promotes vascular senescence and atherosclerosis

AIMS

Vascular senescence, which is closely related to epigenetic regulation, is an early pathological condition in cardiovascular diseases including atherosclerosis. Inhibition of S-adenosylhomocysteine hydrolase (SAHH) and the consequent increase of S-adenosylhomocysteine (SAH), a potent inhibitor of DNA methyltransferase, has been associated with an elevated risk of cardiovascular diseases. This study aimed to investigate whether the inhibition of SAHH accelerates vascular senescence and the development of atherosclerosis.

METHODS AND RESULTS

The case-control study related to vascular aging showed that increased levels of plasma SAH were positively associated with the risk of vascular aging, with an odds ratio (OR) of 3.90 (95% CI, 1.17-13.02). Elevated pulse wave velocity, impaired endothelium-dependent relaxation response, and increased senescence-associated β-galactosidase staining were observed in the artery of SAHH+/- mice at 32 weeks of age. Additionally, elevated expression of p16, p21, and p53, fission morphology of mitochondria, and over-upregulated expression of Drp1 were observed in vascular endothelial cells with SAHH inhibition in vitro and in vivo. Further downregulation of Drp1 using siRNA or its specific inhibitor, mdivi-1, restored the abnormal mitochondrial morphology and rescued the phenotypes of vascular senescence. Furthermore, inhibition of SAHH in APOE-/- mice promoted vascular senescence and atherosclerosis progression, which was attenuated by mdivi-1 treatment. Mechanistically, hypomethylation over the promoter region of DRP1 and downregulation of DNMT1 were demonstrated with SAHH inhibition in HUVECs.

CONCLUSIONS

SAHH inhibition epigenetically upregulates Drp1 expression through repressing DNA methylation in endothelial cells, leading to vascular senescence and atherosclerosis. These results identify SAHH or SAH as a potential therapeutic target for vascular senescence and cardiovascular diseases.

Early hyperlipidemia triggers metabolomic reprogramming with increased SAH, increased acetyl-CoA-cholesterol synthesis, and decreased glycolysis

To identify metabolomic reprogramming in early hyperlipidemia, unbiased metabolome was screened in four tissues from ApoE-/- mice fed with high fat diet (HFD) for 3 weeks. 30, 122, 67, and 97 metabolites in the aorta, heart, liver, and plasma, respectively, were upregulated. 9 upregulated metabolites were uremic toxins, and 13 metabolites, including palmitate, promoted a trained immunity with increased syntheses of acetyl-CoA and cholesterol, increased S-adenosylhomocysteine (SAH) and hypomethylation and decreased glycolysis. The cross-omics analysis found upregulation of 11 metabolite synthetases in ApoE‾/‾ aorta, which promote ROS, cholesterol biosynthesis, and inflammation. Statistical correlation of 12 upregulated metabolites with 37 gene upregulations in ApoE‾/‾ aorta indicated 9 upregulated new metabolites to be proatherogenic. Antioxidant transcription factor NRF2-/- transcriptome analysis indicated that NRF2 suppresses trained immunity-metabolomic reprogramming. Our results have provided novel insights on metabolomic reprogramming in multiple tissues in early hyperlipidemia oriented toward three co-existed new types of trained immunity.

EZH2 can be used as a therapeutic agent for inhibiting endothelial dysfunction

Enhancer of zeste homolog 2 (EZH2) is a catalytic subunit of polycomb repressor complex 2 and plays important roles in endothelial cell homeostasis. EZH2 functionally methylates lysine 27 of histone H3 and represses gene expression through chromatin compaction. EZH2 mediates the effects of environmental stimuli by regulating endothelial functions, such as angiogenesis, endothelial barrier integrity, inflammatory signaling, and endothelial mesenchymal transition. Numerous studies have been conducted to determine the significance of EZH2 in endothelial function. The aim of this review is to provide a concise summary of the roles EZH2 plays in endothelial function and elucidate its therapeutic potential in cardiovascular diseases.

High homocysteine is associated with idiopathic normal pressure hydrocephalus in deep perforating arteriopathy: a cross-sectional study

BACKGROUND AND OBJECTIVE

The pathogenesis and pathophysiology of idiopathic normal pressure hydrocephalus (iNPH) remain unclear. Homocysteine may reduce the compliance of intracranial arteries and damage the endothelial function of the blood-brain barrier (BBB), which may be the underlying mechanism of iNPH. The overlap cases between deep perforating arteriopathy (DPA) and iNPH were not rare for the shared risk factors. We aimed to investigate the relationship between serum homocysteine and iNPH in DPA.

METHODS

A total of 41 DPA patients with iNPH and 49 DPA patients without iNPH were included. Demographic characteristics, vascular risk factors, laboratory results, and neuroimaging data were collected. Multivariable logistic regression analysis was performed to investigate the relationship between serum homocysteine and iNPH in DPA patients.

RESULTS

Patients with iNPH had significantly higher homocysteine levels than those without iNPH (median, 16.34 mmol/L versus 14.28 mmol/L; P = 0.002). There was no significant difference in CSVD burden scores between patients with iNPH and patients without iNPH. Univariate logistic regression analysis demonstrated that patients with homocysteine levels in the Tertile3 were more likely to have iNPH than those in the Tertile1 (OR, 4.929; 95% CI, 1.612-15.071; P = 0.005). The association remained significant after multivariable adjustment for potential confounders, including age, male, hypertension, diabetes mellitus, atherosclerotic cardiovascular disease (ASCVD) or hypercholesterolemia, and eGFR level.

CONCLUSION

Our study indicated that high serum homocysteine levels were independently associated with iNPH in DPA. However, further research is needed to determine the predictive value of homocysteine and to confirm the underlying mechanism between homocysteine and iNPH.

EZH2 and NF-κB: A context-dependent crosstalk and transcriptional regulation in cancer

Epigenetic modifications regulate critical biological processes that play a pivotal role in the pathogenesis of cancer. Enhancer of Zeste Homolog 2 (EZH2), a subunit of the Polycomb-Repressive Complex 2, catalyzes trimethylation of histone H3 on Lys 27 (H3K27) involved in gene silencing. EZH2 is amplified in human cancers and has roles in regulating several cellular processes, including survival, proliferation, invasion, and self-renewal. Though EZH2 is responsible for gene silencing through its canonical role, it also regulates the transcription of several genes promoting carcinogenesis via its non-canonical role. Constitutive activation of Nuclear Factor-kappaB (NF-κB) plays a crucial role in the development and progression of human malignancies. NF-κB is essential for regulating innate and adaptive immune responses and is one of the most important molecules that increases survival during carcinogenesis. Given the evidence that increased survival and proliferation are essential for tumor development and their association with epigenetic modifications, it seems plausible that EZH2 and NF-κB crosstalk may promote cancer progression. In this review, we expand on how EZH2 and NF-κB regulate cellular responses during cancer and their crosstalk of the canonical and non-canonical roles in a context-dependent manner.

Epigenetic Signatures in Arterial Hypertension: Focus on the Microvasculature

Systemic arterial hypertension (AH) is a multifaceted disease characterized by accelerated vascular aging and high cardiometabolic morbidity and mortality. Despite extensive work in the field, the pathogenesis of AH is still incompletely understood, and its treatment remains challenging. Recent evidence has shown a deep involvement of epigenetic signals in the regulation of transcriptional programs underpinning maladaptive vascular remodeling, sympathetic activation and cardiometabolic alterations, all factors predisposing to AH. After occurring, these epigenetic changes have a long-lasting effect on gene dysregulation and do not seem to be reversible upon intensive treatment or the control of cardiovascular risk factors. Among the factors involved in arterial hypertension, microvascular dysfunction plays a central role. This review will focus on the emerging role of epigenetic changes in hypertensive-related microvascular disease, including the different cell types and tissues (endothelial cells, vascular smooth muscle cells and perivascular adipose tissue) as well as the involvement of mechanical/hemodynamic factors, namely, shear stress.

Effects of four weeks lasting aerobic physical activity on cardiovascular biomarkers, oxidative stress and histomorphometric changes of heart and aorta in rats with experimentally induced hyperhomocysteinemia

The aim of this study was to examine the effects of hyperhomocysteinemia and aerobic physical activity on changes of cardiovascular biomarkers in sera, oxidative stress in cardiac tissue, and histomorphometric parameters of heart and aorta in rats. Experiments were conducted on male Wistar albino rats organized into four groups (n = 10, per group): C (control group): 0.9% NaCl 0.2 mL/day; H (homocysteine group): homocysteine 0.45 µmol/g b.w./day; CPA (control + physical activity group): 0.9% NaCl 0.2 mL/day and a program of physical activity on a treadmill; and HPA (homocysteine + physical activity group) homocysteine 0.45 µmol/g b.w./day and a program of physical activity on a treadmill. Substances were applied subcutaneously twice a day. Lipid peroxidation and relative activity of Mn-superoxide dismutase isoform were significantly higher in active hyperhomocysteinemic rats in comparison to sedentary animals. Atherosclerotic plaques were detected in aorta samples of active hyperhomocysteinemic rats and also, they had increased left ventricle wall and interventricular septum, and transverse diameter of cardiomyocytes compared to sedentary groups. Aerobic physical activity in the condition of hyperhomocysteinemia can lead to increased oxidative stress in cardiac tissue and changes in histomorphometric parameters of the heart and aorta, as well increased lipid parameters and cardiac damage biomarkers in sera of rats.

H-Type Hypertension among Black South Africans and the Relationship between Homocysteine, Its Genetic Determinants and Estimates of Vascular Function

Elevated homocysteine (Hcy) increases cardiovascular disease (CVD) risk. Our objective was to emphasize Hcy’s contribution in hypertension and CVD management by determining H-type hypertension (hypertension with Hcy ≥ 10 µmol/L) and associations between Hcy, blood pressure (BP) and estimates of vascular function among Black South Africans. We included 1995 adults (63% female). Plasma Hcy and cardiovascular measures (systolic and diastolic BP (SBP, DBP), pulse pressure, heart rate (HR), carotid-radialis pulse wave velocity (cr-PWV), intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1) were quantified. Five Hcy-related polymorphisms (cystathionine β-synthase (CBS 844ins68, T833C, G9276A); methylenetetrahydrofolate reductase (MTHFR C677T) and methionine synthase (MTR A2756G)) were genotyped. Hcy was >10 µmol/L in 41% (n = 762), and of the 47% (n = 951) hypertensives, 45% (n = 425) presented with H-type. Hcy was higher in hypertensives vs. normotensives (9.86 vs. 8.78 µmol/L, p < 0.0001, effect size 0.56) and correlated positively with SBP, DBP, cr-PWV and ICAM-1 (r > 0.19, p < 0.0001). Over Hcy quartiles, SBP, DBP, HR, cr-PWV and ICAM-1 increased progressively (all p-trends ≤ 0.001). In multiple regression models, Hcy contributed to the variance of SBP, DBP, HR, cr-PWV and ICAM-1. H-type hypertensives also had the lowest MTHFR 677 CC frequency (p = 0.03). Hcy is positively and independently associated with markers of vascular function and raised BP.

Plasma inflammatory biomarkers in cerebral small vessel disease: A review

Cerebral small vessel disease (CSVD) is a group of pathological processes affecting small arteries, arterioles, capillaries, and small veins of the brain. It is one of the most common subtypes of cerebrovascular diseases, especially highly prevalent in elderly populations, and is associated with stroke occurrence and recurrence, cognitive impairment, gait disorders, psychological disturbance, and dysuria. Its diagnosis mainly depends on MRI, characterized by recent small subcortical infarcts, lacunes, white matter hyperintensities (WMHs), enlarged perivascular spaces (EPVS), cerebral microbleeds (CMBs), and brain atrophy. While the pathophysiological processes of CSVD are not fully understood at present, inflammation is noticed as playing an important role. Herein, we aimed to review the relationship between plasma inflammatory biomarkers and the MRI features of CSVD, to provide background for further research.

GSK343, an Inhibitor of Enhancer of Zeste Homolog 2, Reduces Glioblastoma Progression through Inflammatory Process Modulation: Focus on Canonical and Non-Canonical NF-κB/IκBα Pathways

Glioblastoma (GB) is a tumor of the central nervous system characterized by high proliferation and invasiveness. The standard treatment for GB includes radiotherapy and chemotherapy; however, new therapies are needed. Particular attention was given to the role of histone methyltransferase enhancer of zeste-homolog-2 (EZH2) in GB. Recently, several EZH2-inhibitors have been developed, particularly GSK343 is well-known to regulate apoptosis and autophagy processes; however, its abilities to modulate canonical/non-canonical NF-κB/IκBα pathways or an immune response in GB have not yet been investigated. Therefore, this study investigated for the first time the effect of GSK343 on canonical/non-canonical NF-κB/IκBα pathways and the immune response, by an in vitro, in vivo and ex vivo model of GB. In vitro results demonstrated that GSK343 treatments 1, 10 and 25 μM significantly reduced GB cell viability, showing the modulation of canonical/non-canonical NF-κB/IκBα pathway activation. In vivo GSK343 reduced subcutaneous tumor mass, regulating canonical/non-canonical NF-κB/IκBα pathway activation and the levels of reactive oxygen species (ROS), malondialdehyde (MDA), and superoxide dismutase (SOD). Ex vivo results confirmed the anti-proliferative effect of GSK343 and also demonstrated its ability to regulate immune response through CXCL9, CXCL10 and CXCL11 expression in GB. Thus, GSK343 could represent a therapeutic strategy to counteract GB progression, thanks to its ability to modulate canonical/non-canonical NF-κB/IκBα pathways and immune response.

Higher S-adenosylhomocysteine and lower ratio of S-adenosylmethionine to S-adenosylhomocysteine were more closely associated with increased risk of subclinical atherosclerosis than homocysteine

Aim

To examine the relationship of C1 metabolites of the methionine cycle with the risk of subclinical atherosclerosis (SA) in the Chinese population.

Methods

A total of 2,991 participants aged 45–75 years old were included for data analyses based on the baseline data of the Guangzhou Nutrition and Health Cohort. Three core serum methionine metabolites including serum S-adenosylmethionine (SAM), S-adenosylhomocysteine (SAH), and homocysteine (Hcy) were measured by UPLC-MS/MS. SA was determined by B-mode ultrasound measured carotid intima-media thickness (CIMT) at the common artery and bifurcation segments. Multivariable logistic and linear regression models were performed to estimate the associations of C1 metabolites of the methionine cycle with SA risk or CIMT.

Results

After controlling for potential cofounders and other C1 metabolites, in comparison with the lowest quartile, participants in the highest quartile had lower risk of SA by 27.6% (OR = 0.724; 95% CI:0.563–0.93, P_trend = 0.007) for SAM and 32.2% (OR = 0.678; 95% CI:0.538–0.855, P_trend < 0.001) for SAM/SAH, while increased SA risk by 27.9% (OR = 1.279; 95% CI: 1.065–1.535, P_trend < 0.001) for SAH. No significant association was observed for Hcy with SA after further adjustment of SAH and SAM. The results of multivariable linear regression showed similar findings. The highest two standardized coefficients were observed for SAH (β = 0.104 for CCA and 0.121 for BIF, P< 0.001) and SAM/SAH (β = −0.071 for CCA and −0.084 for BIF, P< 0.001). Subgroup analyses suggested more evident associations of SAH with SA were observed in participants of higher cardiovascular risk profiles.

Conclusion

Our cross-sectional data showed higher serum SAH, but lower SAM/SAH were independently associated with increased risk of SA among the Chinese middle-aged and elderly population.

Elevated homocysteine levels, white matter abnormalities and cognitive impairment in patients with late-life depression

Background

Cognitive impairment in late−life depression (LLD) is considered to be caused by neurodegenerative changes. Elevated homocysteine (Hcy) levels may be linked to cognitive abnormalities associated with LLD. The important role of white matter (WM) damage in cognitive impairment and pathogenesis in patients with LLD has been widely reported. However, no research has explored the interrelationships of these features in patients with LLD.

Objective

The goal of the study was to examine the interrelationship between Hcy levels, cognition, and variations in WM microstructure detected by diffusion tensor imaging (DTI) in patients with LLD.

Methods

We recruited 89 healthy controls (HCs) and 113 patients with LLD; then, we measured the plasma Hcy levels of participants in both groups. All individuals performed a battery of neuropsychological tests to measure cognitive ability. Seventy-four patients with LLD and 68 HCs experienced a DTI magnetic resonance imaging (MRI) scan.

Results

Patients with LLD showed significantly lower fractional anisotropy (FA) values in the bilateral inferior longitudinal fasciculus than those of healthy participants. Only in LLD patients was Hcy concentration inversely associated to FA values in the forceps minor. Finally, multiple regression analyses showed that an interaction between Hcy levels and FA values in the right cingulum of the cingulate cortex and right inferior longitudinal fasciculus were independent contributors to the executive function of patients with LLD.

Conclusion

Our results highlight the complex interplay between elevated homocysteine levels and WM abnormalities in the pathophysiology of LLD-related cognitive impairment, consistent with the neurodegeneration hypothesis.

Histone Lysine Methylation Modification and Its Role in Vascular Calcification

Histone methylation is an epigenetic change mediated by histone methyltransferase, and has been connected to the beginning and progression of several diseases. The most common ailments that affect the elderly are cardiovascular and cerebrovascular disorders. They are the leading causes of death, and their incidence is linked to vascular calcification (VC). The key mechanism of VC is the transformation of vascular smooth muscle cells (VSMCs) into osteoblast-like phenotypes, which is a highly adjustable process involving a variety of complex pathophysiological processes, such as metabolic abnormalities, apoptosis, oxidative stress and signalling pathways. Many researchers have investigated the mechanism of VC and related targets for the prevention and treatment of cardiovascular and cerebrovascular diseases. Their findings revealed that histone lysine methylation modification may play a key role in the various stages of VC. As a result, a thorough examination of the role and mechanism of lysine methylation modification in physiological and pathological states is critical, not only for identifying specific molecular markers of VC and new therapeutic targets, but also for directing the development of new related drugs. Finally, we provide this review to discover the association between histone methylation modification and VC, as well as diverse approaches with which to investigate the pathophysiology of VC and prospective treatment possibilities.

Inhibition of S-adenosylhomocysteine hydrolase induces endothelial senescence via hTERT downregulation

BACKGROUND AND AIMS

It has been established that endothelial senescence plays a critical role in the development of atherosclerosis. Elevated S-adenosylhomocysteine (SAH) level induced by inhibition of S-adenosylhomocysteine hydrolase (SAHH) is one of the risk factors of atherosclerosis; however, the interplay between endothelial senescence and inhibition of SAHH is largely unknown.

METHODS

Human umbilical vein endothelial cells (HUVECs) after serial passage were used. SAHH-specific inhibitor adenosine dialdehyde (ADA) and SAHH siRNA treated HUVECs and SAHH^+/-mice were used to investigate the effect of SAHH inhibition on endothelial senescence.

RESULTS

HUVECs exhibited distinct senescence morphology as HUVECs were passaged, together with a decrease in intracellular SAHH expression and an increase in intracellular SAH levels. SAHH inhibition by ADA or SAHH siRNA elevated SA β-gal activity, arrested proliferation, and increased the expression of p16, p21 and p53 in HUVECs and the aortas of mice. In addition, decreased expression of hTERT and reduced occupancy of H3K4me3 over the hTERT promoter region were observed following SAHH inhibition treatment. To further verify the role of hTERT in the endothelial senescence induced by SAHH inhibition, hTERT was overexpressed with a plasmid vector under CMV promoter. hTERT overexpression rescued the senescence phenotypes in endothelial cells induced by SAHH inhibition.

CONCLUSIONS

SAHH inhibition induces endothelial senescence via downregulation of hTERT expression, which is associated with attenuated histone methylation over the hTERT promoter region.

Molecular Signature of Neuroinflammation Induced in Cytokine-Stimulated Human Cortical Spheroids

Crucial in the pathogenesis of neurodegenerative diseases is the process of neuroinflammation that is often linked to the pro-inflammatory cytokines Tumor necrosis factor alpha (TNFα) and Interleukin-1beta (IL-1β). Human cortical spheroids (hCSs) constitute a valuable tool to study the molecular mechanisms underlying neurological diseases in a complex three-dimensional context. We recently designed a protocol to generate hCSs comprising all major brain cell types. Here we stimulate these hCSs for three time periods with TNFα and with IL-1β. Transcriptomic analysis reveals that the main process induced in the TNFα- as well as in the IL-1β-stimulated hCSs is neuroinflammation. Central in the neuroinflammatory response are endothelial cells, microglia and astrocytes, and dysregulated genes encoding cytokines, chemokines and their receptors, and downstream NFκB- and STAT-pathway components. Furthermore, we observe sets of neuroinflammation-related genes that are specifically modulated in the TNFα-stimulated and in the IL-1β-stimulated hCSs. Together, our results help to molecularly understand human neuroinflammation and thus a key mechanism of neurodegeneration.

Metabolomic Profiling of Respiratory Muscles and Lung in Response to Long-Term Controlled Mechanical Ventilation

Critical illness myopathy (CIM) and ventilator-induced diaphragm dysfunction (VIDD) are characterized by severe muscle wasting, muscle paresis, and extubation failure with subsequent increased medical costs and mortality/morbidity rates in intensive care unit (ICU) patients. These negative effects in response to modern critical care have received increasing attention, especially during the current COVID-19 pandemic. Based on experimental and clinical studies from our group, it has been hypothesized that the ventilator-induced lung injury (VILI) and the release of factors systemically play a significant role in the pathogenesis of CIM and VIDD. Our previous experimental/clinical studies have focused on gene/protein expression and the effects on muscle structure and regulation of muscle contraction at the cell and motor protein levels. In the present study, we have extended our interest to alterations at the metabolomic level. An untargeted metabolomics approach was undertaken to study two respiratory muscles (diaphragm and intercostal muscle) and lung tissue in rats exposed to five days controlled mechanical ventilation (CMV). Metabolomic profiles in diaphragm, intercostal muscles and lung tissue were dramatically altered in response to CMV, most metabolites of which belongs to lipids and amino acids. Some metabolites may possess important biofunctions and play essential roles in the metabolic alterations, such as pyruvate, citrate, S-adenosylhomocysteine, alpha-ketoglutarate, glycerol, and cysteine. Metabolic pathway enrichment analysis identified pathway signatures of each tissue, such as decreased metabolites of dipeptides in diaphragm, increased metabolites of branch-chain amino acid metabolism and purine metabolism in intercostals, and increased metabolites of fatty acid metabolism in lung tissue. These metabolite alterations may be associated with an accelerated myofibrillar protein degradation in the two respiratory muscles, an active inflammatory response in all tissues, an attenuated energy production in two respiratory muscles, and enhanced energy production in lung. These results will lay the basis for future clinical studies in ICU patients and hopefully the discovery of biomarkers in early diagnosis and monitoring, as well as the identification of future therapeutic targets.

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.

The Pivotal Immunomodulatory and Anti-Inflammatory Effect of Histone-Lysine N-Methyltransferase in the Glioma Microenvironment: Its Biomarker and Therapy Potentials

Enhancer of zeste homolog 2 (EZH2) is a histone-lysine N-methyltransferase that encrypts a member of the Polycomb group (PcG) family. EZH2 forms a repressive chromatin structure which eventually participates in regulating the development as well as lineage propagation of stem cells and glioma progression. Posttranslational modifications are distinct approaches for the adjusted modification of EZH2 in the development of cancer. The amino acid succession of EZH2 protein makes it appropriate for covalent modifications, like phosphorylation, acetylation, O-GlcNAcylation, methylation, ubiquitination, and sumoylation. The glioma microenvironment is a dynamic component that comprises, besides glioma cells and glioma stem cells, a complex network that comprises diverse cell types like endothelial cells, astrocytes, and microglia as well as stromal components, soluble factors, and the extracellular membrane. EZH2 is well recognized as an essential modulator of cell invasion as well as metastasis in glioma. EZH2 oversecretion was implicated in the malfunction of several fundamental signaling pathways like Wnt/β-catenin signaling, Ras and NF-κB signaling, PI3K/AKT signaling, β-adrenergic receptor signaling, and bone morphogenetic protein as well as NOTCH signaling pathways. EZH2 was more secreted in glioblastoma multiforme than in low-grade gliomas as well as extremely secreted in U251 and U87 human glioma cells. Thus, the blockade of EZH2 expression in glioma could be of therapeutic value for patients with glioma. The suppression of EZH2 gene secretion was capable of reversing temozolomide resistance in patients with glioma. EZH2 is a promising therapeutic as well as prognostic biomarker for the treatment of glioma.

A Hypomethylating Ketogenic Diet in Apolipoprotein E-Deficient Mice: A Pilot Study on Vascular Effects and Specific Epigenetic Changes

Hyperhomocysteneinemia (HHcy) is common in the general population and is a risk factor for atherosclerosis by mechanisms that are still elusive. A hypomethylated status of epigenetically relevant targets may contribute to the vascular toxicity associated with HHcy. Ketogenic diets (KD) are diets with a severely restricted amount of carbohydrates that are being widely used, mainly for weight-loss purposes. However, studies associating nutritional ketosis and HHcy are lacking. This pilot study investigates the effects of mild HHcy induced by nutritional manipulation of the methionine metabolism in the absence of dietary carbohydrates on disease progression and specific epigenetic changes in the apolipoprotein-E deficient (apoE^-/-) mouse model. ApoE^-/- mice were either fed a KD, a diet with the same macronutrient composition but low in methyl donors (low methyl KD, LMKD), or control diet. After 4, 8 or 12 weeks plasma was collected for the quantification of: (1) nutritional ketosis, (i.e., the ketone body beta-hydroxybutyrate using a colorimetric assay); (2) homocysteine by HPLC; (3) the methylating potential S-adenosylmethionine to S-adenosylhomocysteine ratio (AdoHcy/AdoMet) by LC-MS/MS; and (4) the inflammatory cytokine monocyte chemoattractant protein 1 (MCP1) by ELISA. After 12 weeks, aortas were collected to assess: (1) the vascular AdoHcy/AdoMet ratio; (2) the volume of atherosclerotic lesions by high-field magnetic resonance imaging (14T-MRI); and (3) the content of specific epigenetic tags (H3K27me3 and H3K27ac) by immunofluorescence. The results confirmed the presence of nutritional ketosis in KD and LMKD mice but not in the control mice. As expected, mild HHcy was only detected in the LMKD-fed mice. Significantly decreased MCP1 plasma levels and plaque burden were observed in control mice versus the other two groups, together with an increased content of one of the investigated epigenetic tags (H3K27me3) but not of the other (H3K27ac). Moreover, we are unable to detect any significant differences at the p < 0.05 level for MCP1 plasma levels, vascular AdoMet:AdoHcy ratio levels, plaque burden, and specific epigenetic content between the latter two groups. Nevertheless, the systemic methylating index was significantly decreased in LMKD mice versus the other two groups, reinforcing the possibility that the levels of accumulated homocysteine were insufficient to affect vascular transmethylation reactions. Further studies addressing nutritional ketosis in the presence of mild HHcy should use a higher number of animals and are warranted to confirm these preliminary observations.

Kuanxiong Aerosol () in Treatment of Angina Pectoris: A Literature Review and Network Pharmacology

Angina pectoris (AP) is the most common symptom of cardiovascular diseases, which seriously affects the quality of life in cardiovascular patients. Kuanxiong (KX) Aerosol (), a compound preparation that consists of 5 traditional Chinese medicines: Herba Asari , Rhizoma Alpiniae Officinarum, Lignum Santali Albi, Fructus Piperis Longi, and Borneolum, has been used in the treatment of AP for many years, exhibiting a significant curative effect and less side-effect. For the convenience and comprehensive understanding of KX Aerosol, this review systematically summarizes evidence on KX Aerosol in the treatment of AP including the pharmacological effects of its composition, clinical research, animal experiments, and network pharmacology prediction. Meanwhile, we highlight the research limitation of KX Aerosol at present. This review may guide the clinical application of KX Aerosol and further provide a reference for the research of AP.

Molecular processes mediating hyperhomocysteinemia-induced metabolic reprogramming, redox regulation and growth inhibition in endothelial cells

Hyperhomocysteinemia (HHcy) is an established and potent independent risk factor for degenerative diseases, including cardiovascular disease (CVD), Alzheimer disease, type II diabetes mellitus, and chronic kidney disease. HHcy has been shown to inhibit proliferation and promote inflammatory responses in endothelial cells (EC), and impair endothelial function, a hallmark for vascular injury. However, metabolic processes and molecular mechanisms mediating HHcy-induced endothelial injury remains to be elucidated. This study examined the effects of HHcy on the expression of microRNA (miRNA) and mRNA in human aortic EC treated with a pathophysiologically relevant concentration of homocysteine (Hcy 500 μM). We performed a set of extensive bioinformatics analyses to identify HHcy-altered metabolic and molecular processes. The global functional implications and molecular network were determined by Gene Set Enrichment Analysis (GSEA) followed by Cytoscape analysis. We identified 244 significantly differentially expressed (SDE) mRNA, their relevant functional pathways, and 45 SDE miRNA. HHcy-altered SDE inversely correlated miRNA-mRNA pairs (45 induced/14 reduced mRNA) were discovered and applied to network construction using an experimentally verified database. We established a hypothetical model to describe the biochemical and molecular network with these specified miRNA/mRNA axes, finding: 1) HHcy causes metabolic reprogramming by increasing glucose uptake and oxidation, by glycogen debranching and NAD⁺/CoA synthesis, and by stimulating mitochondrial reactive oxygen species production via NNT/IDH2 suppression-induced NAD⁺/NADP-NADPH/NADP⁺ metabolism disruption; 2) HHcy activates inflammatory responses by activating inflammasome-pyroptosis mainly through ↓miR193b→↑CASP-9 signaling and by inducing IL-1β and adhesion molecules through the ↓miR29c→↑NEDD9 and the ↓miR1256→↑ICAM-1 axes, as well as GPCR and interferon α/β signaling; 3) HHcy promotes cell degradation by the activation of lysosome autophagy and ubiquitin proteasome systems; 4) HHcy causes cell cycle arrest at G1/S and S/G2 transitions, suppresses spindle checkpoint complex and cytokinetic abscission, and suppresses proliferation through ↓miRNA335/↑VASH1 and other axes. These findings are in accordance with our previous studies and add a wealth of heretofore-unexplored molecular and metabolic mechanisms underlying HHcy-induced endothelial injury. This is the first study to consider the effects of HHcy on both global mRNA and miRNA expression changes for mechanism identification. Molecular axes and biochemical processes identified in this study are useful not only for the understanding of mechanisms underlying HHcy-induced endothelial injury, but also for discovering therapeutic targets for CVD in general.

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Identified multiple HHcy-altered metabolic and molecular processes potentially responsible for HHcy-induced endothelial injury via examining global mRNA/miRNA expression changes in Hcy-treated EC and performing comprehensive bioinformatic studies.

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HHcy may activate glucose uptake signaling via the ↓miR148b→↑SLC2A axis.

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HHcy may induce glucose oxidation signaling by switching pyruvate metabolism from lactate synthesis to mitochondrial oxidation via expression changes of ↑MPC1 & ↓LDHB.

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HHcy may disrupt redox homeostasis mostly by suppressing NNT/IDH2-related mt-NADPH/mt-NAD⁺ signaling.

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HHcy may increase FA β-oxidation, glutamine, TCA cycle and OXPHOS signaling.

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HHcy may activate inflammatory signaling via the ↓miR29c→↑NEDD9 and the ↓miR1256→↑ICAM-1 axes.

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HHcy may activate inflammasome/pyroptosis-related signaling by the ↓miR137→↑TLR3, the ↓miR574→↑TRAF5, and the ↓miR193b→↑CASP-9 axes, and induce IL1α/β and CASP-10/7.

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HHcy may induce inflammation signaling via GPCR activation through the ↓miRNA335→↑CXCR4/↑GNA14 axes.

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HHcy may activate molecular degradation process signaling through the ↓miRNA335→↑ASAH1/↑ABCB9 axes.

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HHcy may suppress cell cycle and proliferation through the miR491→↓HMGA2→↓CCNA2/CCNB2, the ↓miR335→↑VASH1, the ↓miR181a→↑PHLDA1, the miR6045→↓CENPH, the miR22→↓PRR11/↓BRCA2, and the miR605/miR497/miR514a→CEP55 axes

Current progress on the mechanisms of hyperhomocysteinemia-induced vascular injury and use of natural polyphenol compounds

Cardiovascular disease is one of the most common diseases in the elderly population, and its incidence has rapidly increased with the prolongation of life expectancy. Hyperhomocysteinemia is an independent risk factor for various cardiovascular diseases, including atherosclerosis, and damage to vascular function plays an initial role in its pathogenesis. This review presents the latest knowledge on the mechanisms of vascular injury caused by hyperhomocysteinemia, including oxidative stress, endoplasmic reticulum stress, protein N-homocysteinization, and epigenetic modification, and discusses the therapeutic targets of natural polyphenols. Studies have shown that natural polyphenols in plants can reduce homocysteine levels and regulate DNA methylation by acting on oxidative stress and endoplasmic reticulum stress-related signaling pathways, thus improving hyperhomocysteinemia-induced vascular injury. Natural polyphenols obtained via daily diet are safer and have more practical significance in the prevention and treatment of chronic diseases than traditional drugs.

Feedback activation of NF-KB signaling leads to adaptive resistance to EZH2 inhibitors in prostate cancer cells

Background

Prostate cancer (PCa) is the most common malignant tumor in developed countries, which has seriously threatened men’s lifestyle and quality of life. The up-regulation of EZH2 is associated with advanced PCa and poor prognosis, making it a promising therapeutic target. However, the EZH2 inhibitors-based treatment is basically ineffective against PCa, which limits its clinical application.

Methods

Microarray data (GSE107779) from LNCaP cells treated with either siRNA against EZH2 or a EZH2 inhibitor EPZ6438 was analyzed by Limma R package. Western blot, real-time PCR and luciferase reporter assays were used to determine the EZH2-SOX9-TNFRSF11A axis and the activity of NF-κB signaling in PCa cells. CCK-8 assay was used to determine the viability of PCa cells following various treatments.

Results

Genetic ablation or pharmacological inhibition of EZH2 leads to feedback activation of NF-κB signaling in PCa cells. EZH2-dependent SOX9 expression regulates the activation of NF-κB signaling. TNFRSF11A, also known as receptor activator of NF-κB (RANK), is a downstream target of SOX9 in PCa cells. SOX9 recognizes two putative SOX9 response elements in the promoter region of TNFRSF11A gene to drive TNFRSF11A expression and downstream NF-κB signaling activation. Suppression of the NF-κB signaling by either TNFRSF11A silencing or BAY11-7082 treatment rendered PCa cells to EZH2 inhibitors.

Conclusion

Collectively, our finding reveals a EZH2-SOX9-TNFRSF11A axis in the regulation of activity of NF-κB signaling in PCa cells and suggests that a combination of EZH2 inhibitors and BAY11-7082 would be an effective approach for the treatment of PCa patients in the future.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-01897-w.

Correlation between total homocysteine and cerebral small vessel disease: A Mendelian randomization study

BACKGROUND AND PURPOSE

Cerebral small vessel disease (CSVD) is a clinical imaging syndrome with diverse etiology. Total homocysteine (HCY) level might increase the risk of myocardial and cerebral infarction by damaging the vascular endothelium. We aimed to explore the correlation between total HCY and CSVD imaging burden, based on Mendelian randomization methods.

METHODS

A total of 1,023 participants of the Shunyi study, a population-based cohort study, were included. Vascular risk factors, total HCY levels and methylenetetrahydrofolate reductase (MTHFR) gene mutations (C677T and A1298C) were examined. CSVD imaging markers, including lacunes, cerebral microbleeds, white matter hyperintensity, enlarged perivascular space and brain parenchymal fraction (BPF) were also assessed.

RESULTS

Mutations of C677T were significantly correlated with increased total HCY levels (CC→TT: β = 0.28, p < 0.0001), while mutations of A1298C were correlated with decreased total HCY levels (AA→AC: β = -0.13, p < 0.0001; AA→CC: β = -0.25, p = 0.004). In the Mendelian randomization study, the C677T genotype was significantly associated with lacunes (CC→CT: odds ratio [OR] 2.76, p = 0.008; CC→TT: OR 2.50, p = 0.018), and the A1298C genotype was significantly correlated with BPF (AA→CC: β = 1.32, p = 0.015). Similarly, in multivariate regression analysis, total HCY levels were significantly correlated with lacunes (OR 2.14, p < 0.0001) and negatively correlated with BPF (β = -0.55, p = 0.004). Age, sex and vascular risk factors were adjusted for.

CONCLUSIONS

Total HCY level was correlated with imaging burden of CSVD, especially with lacunes and brain volume loss. For individuals with risk genetic predisposition, enhanced homocysteine-lowering strategies might be necessary to reduce the risk and progress of CSVD.

From Inflammation to the Onset of Fibrosis through A2A Receptors in Kidneys from Deceased Donors

Pretransplant graft inflammation could be involved in the worse prognosis of deceased donor (DD) kidney transplants. A2A adenosine receptor (A_2AR) can stimulate anti-inflammatory M2 macrophages, leading to fibrosis if injury and inflammation persist. Pre-implantation biopsies of kidney donors (47 DD and 21 living donors (LD)) were used to analyze expression levels and activated intracellular pathways related to inflammatory and pro-fibrotic processes. A_2AR expression and PKA pathway were enhanced in DD kidneys. A_2AR gene expression correlated with TGF-β1 and other profibrotic markers, as well as CD163, C/EBPβ, and Col1A1, which are highly expressed in DD kidneys. TNF-α mRNA levels correlated with profibrotic and anti-inflammatory factors such as TGF-β1 and A_2AR. Experiments with THP-1 cells point to the involvement of the TNF-α/NF-κB pathway in the up-regulation of A_2AR, which induces the M2 phenotype increasing CD163 and TGF-β1 expression. In DD kidneys, the TNF-α/NF-κB pathway could be involved in the increase of A_2AR expression, which would activate the PKA–CREB axis, inducing the macrophage M2 phenotype, TGF-β1 production, and ultimately, fibrosis. Thus, in inflamed DD kidneys, an increase in A_2AR expression is associated with the onset of fibrosis, which may contribute to graft dysfunction and prognostic differences between DD and LD transplants.

Transcriptional Induction of Cystathionine γ-Lyase, a Reactive Sulfur-Producing Enzyme, by Copper Diethyldithiocarbamate in Cultured Vascular Endothelial Cells

As toxic substances can enter the circulating blood and cross endothelial monolayers to reach parenchymal cells in organs, vascular endothelial cells are an important target compartment for such substances. Reactive sulfur species protect cells against oxidative stress and toxic substances, including heavy metals. Reactive sulfur species are produced by enzymes, such as cystathionine γ-lyase (CSE), cystathionine β-synthase, 3-mercaptopyruvate sulfurtransferase, and cysteinyl-tRNA synthetase. However, little is known about the regulatory mechanisms underlying the expression of these enzymes in vascular endothelial cells. Bio-organometallics is a research field that analyzes biological systems using organic-inorganic hybrid molecules (organometallic compounds and metal coordinating compounds) as molecular probes. In the present study, we analyzed intracellular signaling pathways that mediate the expression of reactive sulfur species-producing enzymes in cultured bovine aortic endothelial cells, using copper diethyldithiocarbamate (Cu10). Cu10 selectively upregulated CSE gene expression in vascular endothelial cells independent of cell density. This transcriptional induction of endothelial CSE required both the diethyldithiocarbamate scaffold and the coordinated copper ion. Additionally, the present study revealed that ERK1/2, p38 MAPK, and hypoxia-inducible factor (HIF)-1α/HIF-1β pathways mediate transcriptional induction of endothelial CSE by Cu10. The transcription factors NF-κB, Sp1, and ATF4 were suggested to act in constitutive CSE expression, although the possibility that they are involved in the CSE induction by Cu10 cannot be excluded. The present study used a copper complex as a molecular probe to reveal that the transcription of CSE is regulated by multiple pathways in vascular endothelial cells, including ERK1/2, p38 MAPK, and HIF-1α/HIF-1β. Bio-organometallics appears to be an effective strategy for analyzing the functions of intracellular signaling pathways in vascular endothelial cells.

Food-derived bioactive compounds with anti-aging potential for nutricosmetic and cosmeceutical products

Besides providing essential nutrients for humans, food contains bioactive compounds that exert diverse biological activities such as anti-microbial, anti-cancerogenic, anti-viral, anti-inflammatory and antioxidant. The cosmetic industry is interested in natural bioactive compounds for their use in nutricosmetic and cosmeceutical products. These products aimed to reduce skin aging, inflammation or provide photoprotection against UV radiation. As a result, nutricosmetics and cosmeceuticals are becoming innovative self-care products in the beauty market. These products contain phytochemicals as active compounds obtained from fruits, vegetables, legumes, medicinal herbs and plants with anti-aging potential. This review summarizes the information within the last 5 years related to bioactive compounds present in fruits, vegetables, herbs and spices commonly used for human consumption. Their antioxidant and biological potential for modulating molecular markers involved in the aging process, as well as their mechanism of action. Diverse natural foods and their byproducts could be used as a source of bioactive compounds for developing cosmeceutical and nutricosmetic products.

Cross-tolerance: embryonic heat conditioning induces inflammatory resilience by affecting different layers of epigenetic mechanisms regulating IL6 expression later in life

A stressor can induce resilience in another, different stressor, a phenomenon known as cross-tolerance. To learn if cross-tolerance is governed by epigenetic regulation, we used embryonic heat conditioning (EHC) in chicks, during the development of the hypothalamus, to increase the immunization response. Indeed, EHC induced a lifelong systemic antibody response to immunization, in addition to reduced hypothalamic IL6 inflammatory expression following LPS challenge. Since the outcome of EHC was long-term cross-tolerance with the immune system, we studied possible epigenetic mechanisms. We first analysed the methylation and hydroxymethylation patterns of IL6. We found reduced hydroxymethylation on IL6 intron 1 in the EHC group, a segment enriched with CpGs and NFkB-binding sites. Luciferase assay in cell lines expressing NFkB showed that IL6 intron 1 is indeed an enhancer. ChiP in the same segment against NFkB in the hypothalamus presented reduced binding to IL6 intron 1 in the EHC group, before and during LPS challenge. In parallel, EHC chicks' IL6 intron 1 presented increased H3K27me3, a repressive translational modification mediated by EZH2. This histone modification occurred during embryonic conditioning and persisted later in life. Moreover, we showed reduced expression of miR-26a, which inhibits EZH2 transcription, during conditioning along with increased EZH2 expression. We demonstrate that stress cross-tolerance, which was indicated by EHC-induced inflammatory resilience and displayed by attenuated inflammatory expression of IL6, is regulated by different epigenetic layers.

No Effect of Diet-Induced Mild Hyperhomocysteinemia on Vascular Methylating Capacity, Atherosclerosis Progression, and Specific Histone Methylation

Hyperhomocysteinemia (HHcy) is a risk factor for atherosclerosis through mechanisms which are still incompletely defined. One possible mechanism involves the hypomethylation of the nuclear histone proteins to favor the progression of atherosclerosis. In previous cell studies, hypomethylating stress decreased a specific epigenetic tag (the trimethylation of lysine 27 on histone H3, H3K27me3) to promote endothelial dysfunction and activation, i.e., an atherogenic phenotype. Here, we conducted a pilot study to investigate the impact of mild HHcy on vascular methylating index, atherosclerosis progression and H3K27me3 aortic content in apolipoprotein E-deficient (ApoE ^-/-) mice. In two different sets of experiments, male mice were fed high-fat, low in methyl donors (HFLM), or control (HF) diets for 16 (Study A) or 12 (Study B) weeks. At multiple time points, plasma was collected for (1) quantification of total homocysteine (tHcy) by high-performance liquid chromatography; or (2) the methylation index of S-adenosylmethionine to S-adenosylhomocysteine (SAM:SAH ratio) by liquid chromatography tandem-mass spectrometry; or (3) a panel of inflammatory cytokines previously implicated in atherosclerosis by a multiplex assay. At the end point, aortas were collected and used to assess (1) the methylating index (SAM:SAH ratio); (2) the volume of aortic atherosclerotic plaque assessed by high field magnetic resonance imaging; and (3) the vascular content of H3K27me3 by immunohistochemistry. The results showed that, in both studies, HFLM-fed mice, but not those mice fed control diets, accumulated mildly elevated tHcy plasmatic concentrations. However, the pattern of changes in the inflammatory cytokines did not support a major difference in systemic inflammation between these groups. Accordingly, in both studies, no significant differences were detected for the aortic methylating index, plaque burden, and H3K27me3 vascular content between HF and HFLM-fed mice. Surprisingly however, a decreased plasma SAM: SAH was also observed, suggesting that the plasma compartment does not always reflect the vascular concentrations of these two metabolites, at least in this model. Mild HHcy in vivo was not be sufficient to induce vascular hypomethylating stress or the progression of atherosclerosis, suggesting that only higher accumulations of plasma tHcy will exhibit vascular toxicity and promote specific epigenetic dysregulation.

The Epigenetic Profile of Tumor Endothelial Cells. Effects of Combined Therapy with Antiangiogenic and Epigenetic Drugs on Cancer Progression

Tumors require a constant supply of nutrients to grow which are provided through tumor blood vessels. To metastasize, tumors need a route to enter circulation, that route is also provided by tumor blood vessels. Thus, angiogenesis is necessary for both tumor progression and metastasis. Angiogenesis is tightly regulated by a balance of angiogenic and antiangiogenic factors. Angiogenic factors of the vascular endothelial growth factor (VEGF) family lead to the activation of endothelial cells, proliferation, and neovascularization. Significant VEGF-A upregulation is commonly observed in cancer cells, also due to hypoxic conditions, and activates endothelial cells (ECs) by paracrine signaling stimulating cell migration and proliferation, resulting in tumor-dependent angiogenesis. Conversely, antiangiogenic factors inhibit angiogenesis by suppressing ECs activation. One of the best-known anti-angiogenic factors is thrombospondin-1 (TSP-1). In pathological angiogenesis, the balance shifts towards the proangiogenic factors and an angiogenic switch that promotes tumor angiogenesis. Here, we review the current literature supporting the notion of the existence of two different endothelial lineages: normal endothelial cells (NECs), representing the physiological form of vascular endothelium, and tumor endothelial cells (TECs), which are strongly promoted by the tumor microenvironment and are biologically different from NECs. The angiogenic switch would be also important for the explanation of the differences between NECs and TECs, as angiogenic factors, cytokines and growth factors secreted into the tumor microenvironment may cause genetic instability. In this review, we focus on the epigenetic differences between the two endothelial lineages, which provide a possible window for pharmacological targeting of TECs.

Histone methylation and vascular biology

The vasculature not only transports oxygenated blood, metabolites, and waste products but also serves as a conduit for hormonal communication between distant tissues. Therefore, it is important to maintain homeostasis within the vasculature. Recent studies have greatly expanded our understanding of the regulation of vasculature development and vascular-related diseases at the epigenetic level, including by protein posttranslational modifications, DNA methylation, and noncoding RNAs. Integrating epigenetic mechanisms into the pathophysiologic conceptualization of complex and multifactorial vascular-related diseases may provide promising therapeutic approaches. Several reviews have presented detailed discussions of epigenetic mechanisms not including histone methylation in vascular biology. In this review, we primarily discuss histone methylation in vascular development and maturity, and in vascular diseases.

Metabolic Control over mTOR-Dependent Diapause-like State

Regulation of embryonic diapause, dormancy that interrupts the tight connection between developmental stage and time, is still poorly understood. Here, we characterize the transcriptional and metabolite profiles of mouse diapause embryos and identify unique gene expression and metabolic signatures with activated lipolysis, glycolysis, and metabolic pathways regulated by AMPK. Lipolysis is increased due to mTORC2 repression, increasing fatty acids to support cell survival. We further show that starvation in pre-implantation ICM-derived mouse ESCs induces a reversible dormant state, transcriptionally mimicking the in vivo diapause stage. During starvation, Lkb1, an upstream kinase of AMPK, represses mTOR, which induces a reversible glycolytic and epigenetically H4K16Ac-negative, diapause-like state. Diapause furthermore activates expression of glutamine transporters SLC38A1/2. We show by genetic and small molecule inhibitors that glutamine transporters are essential for the H4K16Ac-negative, diapause state. These data suggest that mTORC1/2 inhibition, regulated by amino acid levels, is causal for diapause metabolism and epigenetic state.

Targeting NF-κB signaling pathway in cancer by dietary polyphenols

Being a transcription factor, NF-κB regulates gene expressions involving cell survival and proliferation, drug resistance, metastasis, and angiogenesis. The activation of NF-κB plays a central role in the development of inflammation and cancer. Thus, the down-regulation of NF-κB may be an exciting target in prevention and treatment of cancer. NF-κB could act as a tumor activator or tumor suppressant decided by the site of action (organ). Polyphenols are widely distributed in plant species, consumption of which have been documented to negatively regulate the NF-κB signaling pathway. They depress the phosphorylation of kinases, inhibit NF-κB translocate into the nucleus as well as interfere interactions between NF-κB and DNA. Through inhibition of NF-κB, polyphenols downregulate inflammatory cascade, induce apoptosis and decrease cell proliferation and metastasis. This review highlights the anticancer effects of polyphenols on the basis of NF-κB signaling pathway regulation.

S-amlodipine improves endothelial dysfunction via the RANK/RANKL/OPG system by regulating microRNA-155 in hypertension

S-amlodipine has been broadly used to treat hypertension, but its protective effects and underlying mechanism remain controversial. The purpose of our study was to investigate the mechanism by which S-amlodipine improves endothelial dysfunction. Specifically, we investigated if S-amlodipine regulates RANK/RANKL/OPG and micro-RNA 155 (miR-155) levels. Spontaneous hypertensive rats (SHR) were randomly divided into two groups: SHR (n = 12) and S-amlodipine (n = 12). We found that left ventricular ejection fraction (LVEF) increased significantly in the S-amlodipine group compared to the SHR group. After 10 weeks of S-amlodipine treatment, tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) levels were significantly lower and eNOS and NO production was significantly higher in the S-amlodipine group compared to the SHR group. In human umbilical vein endothelial cells (HUVECs), miR-155, RANK, and RANKL levels were significantly decreased, while OPG mRNA levels were significantly increased in the S-amlodipine group. HUVECs were transfected with miR-155 mimics or an inhibitor to determine the relationship between miR-155 and RANK/RANKL/OPG and NF-κB signaling. OPG mRNA levels following miR-155 inhibition were significantly higher compared to levels following treatment with miR-155 mimics. S-amlodipine significantly inhibited RANKL expression and NF-κB phosphorylation, and there were no significant differences in response to the NF-κB inhibitor (Bay110785). RANKL expression and NF-κB phosphorylation significantly decreased in the miR-155 inhibitor group. Furthermore, OPG protein expression significantly increased in response to miR-155 inhibition and S-amlodipine treatment (all p < 0.05). Our results indicate that S-amlodipine inhibits inflammation and protects against endothelial dysfunction, likely via regulating the RANK/RANKL/OPG pathway, which appears to be downstream of miR-155.

The Contribution of Homocysteine Metabolism Disruption to Endothelial Dysfunction: State-of-the-Art

Homocysteine (Hcy) is a sulfur-containing non-proteinogenic amino acid formed during the metabolism of the essential amino acid methionine. Hcy is considered a risk factor for atherosclerosis and cardiovascular disease (CVD), but the molecular basis of these associations remains elusive. The impairment of endothelial function, a key initial event in the setting of atherosclerosis and CVD, is recurrently observed in hyperhomocysteinemia (HHcy). Various observations may explain the vascular toxicity associated with HHcy. For instance, Hcy interferes with the production of nitric oxide (NO), a gaseous master regulator of endothelial homeostasis. Moreover, Hcy deregulates the signaling pathways associated with another essential endothelial gasotransmitter: hydrogen sulfide. Hcy also mediates the loss of critical endothelial antioxidant systems and increases the intracellular concentration of reactive oxygen species (ROS) yielding oxidative stress. ROS disturb lipoprotein metabolism, contributing to the growth of atherosclerotic vascular lesions. Moreover, excess Hcy maybe be indirectly incorporated into proteins, a process referred to as protein N-homocysteinylation, inducing vascular damage. Lastly, cellular hypomethylation caused by build-up of S-adenosylhomocysteine (AdoHcy) also contributes to the molecular basis of Hcy-induced vascular toxicity, a mechanism that has merited our attention in particular. AdoHcy is the metabolic precursor of Hcy, which accumulates in the setting of HHcy and is a negative regulator of most cell methyltransferases. In this review, we examine the biosynthesis and catabolism of Hcy and critically revise recent findings linking disruption of this metabolism and endothelial dysfunction, emphasizing the impact of HHcy on endothelial cell methylation status.

The central role of inflammatory signaling in the pathogenesis of myelodysplastic syndromes

In cancer biology, tumor-promoting inflammation and an inflammatory microenvironment play a vital role in disease pathogenesis. In the past decade, aberrant innate immune activation and proinflammatory signaling within the malignant clone and the bone marrow (BM) microenvironment were identified as key pathogenic drivers of myelodysplastic syndromes (MDS). In particular, S100A9-mediated NOD-like receptor protein 3 (NLRP3) inflammasome activation directs an inflammatory, lytic form of cell death termed pyroptosis that underlies many of the hallmark features of the disease. This circuit and accompanying release of other danger-associated molecular patterns expands BM myeloid-derived suppressor cells, creating a feed-forward process propagating inflammasome activation. Furthermore, somatic gene mutations of varied functional classes license the NLRP3 inflammasome to generate a common phenotype with excess reactive oxygen species generation, Wnt/β-catenin-induced proliferation, cation flux-induced cell swelling, and caspase-1 activation. Recent investigations have shown that activation of the NLRP3 inflammasome complex has more broad-reaching importance, particularly as a possible disease-specific biomarker for MDS, and, mechanistically, as a driver of cardiovascular morbidity/mortality in individuals with age-related, clonal hematopoiesis. Recognition of the mechanistic role of aberrant innate immune activation in MDS provides a new perspective for therapeutic development that could usher in a novel class of disease-modifying agents.

Systems Biology Approaches to Redox Metabolism in Stress and Disease States

SIGNIFICANCE

All cellular metabolic processes are tied to the cellular redox environment. Therefore, maintaining redox homeostasis is critically important for normal cell function. Indeed, redox stress contributes to the pathobiology of many human diseases. The cellular redox response system is composed of numerous interconnected components, including free radicals, redox couples, protein thiols, enzymes, metabolites, and transcription factors. Moreover, interactions between and among these factors are regulated in time and space. Owing to their complexity, systems biology approaches to the characterization of the cellular redox response system may provide insights into novel homeostatic mechanisms and methods of therapeutic reprogramming. Recent Advances: The emergence and development of systems biology has brought forth a set of innovative technologies that provide new avenues for studying redox metabolism. This article will review these systems biology approaches and their potential application to the study of redox metabolism in stress and disease states.

CRITICAL ISSUES

Clarifying the scope of biological intermediaries affected by dysregulated redox metabolism requires methods that are suitable for analyzing big datasets as classical methods that do not account for multiple interactions are unlikely to portray the totality of perturbed metabolic systems.

FUTURE DIRECTIONS

Given the diverse redox microenvironments within cells, it will be important to improve the spatial resolution of omic approaches. Futures studies on the integration of multiple systems-based methods and heterogeneous omics data for redox metabolism are required to accelerate the development of the field of redox systems biology. Antioxid. Redox Signal. 29, 953-972.

Role of Nitric Oxide and Hydrogen Sulfide in Ischemic Stroke and the Emergent Epigenetic Underpinnings

Nitric oxide (NO) and hydrogen sulfide (H₂S) are the key gasotransmitters with an imperious role in the maintenance of cerebrovascular homeostasis. A decline in their levels contributes to endothelial dysfunction that portends ischemic stroke (IS) or cerebral ischemia/reperfusion (CI/R). Nevertheless, their exorbitant production during CI/R is associated with exacerbation of cerebrovascular injury in the post-stroke epoch. NO-producing nitric oxide synthases are implicated in IS pathology and their activity is regulated, inter alia, by various post-translational modifications and chromatin-based mechanisms. These account for heterogeneous alterations in NO production in a disease setting like IS. Interestingly, NO per se has been posited as an endogenous epigenetic modulator. Further, there is compelling evidence for an ingenious crosstalk between NO and H₂S in effecting the canonical (direct) and non-canonical (off-target collateral) functions. In this regard, NO-mediated S-nitrosylation and H₂S-mediated S-sulfhydration of specific reactive thiols in an expanding array of target proteins are the principal modalities mediating the all-pervasive influence of NO and H₂S on cell fate in an ischemic brain. An integrated stress response subsuming unfolded protein response and autophagy to cellular stressors like endoplasmic reticulum stress, in part, is entrenched in such signaling modalities that substantiate the role of NO and H₂S in priming the cells for stress response. The precis presented here provides a comprehension on the multifarious actions of NO and H₂S and their epigenetic underpinnings, their crosstalk in maintenance of cerebrovascular homeostasis, and their "Janus bifrons" effect in IS milieu together with plausible therapeutic implications.

Cell‑specific histone modifications in atherosclerosis (Review)

Histone modifications are the key epigenetic mechanisms that have been identified to regulate gene expression in many human diseases. However, in the early developmental stages, such as in utero and the postnatal stages, histone modifications are essential for gene regulation and cell growth. Atherosclerosis represents a classical example of the involvement of different cell types, and their cumulative effects in the development of atheroma and the progression of the disease. Post translational modifications on proteins either induces their functional activity or renders them inactive. Post translational modifications such as methylation or acetylation on histones have been well characterized, and their role in enhancing or inhibiting specific gene expression was clearly elucidated. In the present review article, the critical roles of different histone modifications that occur in atherosclerosis have been summarized. Different histone proteins have been identified to serve a critical role in the development of atherosclerosis. Specifically, histone methylation and histone acetylation in monocytes, macrophages, vascular smooth muscle cells and in endothelial cells during the progression of atherosclerosis, have been well reported. In recent years, different target molecules and genes that regulate histone modifications have been examined for their effects in the treatment of atherosclerosis in animal models and in clinical trials. An increasing body of evidence suggests that these epigenetic changes resulting from DNA methylation and non-coding RNA may also be associated with histone modifications, thereby indicating that novel therapeutic strategies can be developed by targeting these post translational modifications, which may in turn aid in the treatment of atherosclerosis.

Folinic Acid Increases Protein Arginine Methylation in Human Endothelial Cells

Elevated plasma total homocysteine (tHcy) is associated with increased risk of cardiovascular disease, but the mechanisms underlying this association are not completely understood. Cellular hypomethylation has been suggested to be a key pathophysiologic mechanism, since S-adenosylhomocysteine (AdoHcy), the Hcy metabolic precursor and a potent inhibitor of methyltransferase activity, accumulates in the setting of hyperhomocysteinemia. In this study, the impact of folate and methionine on intracellular AdoHcy levels and protein arginine methylation status was studied. Human endothelial cells were incubated with increasing concentrations of folinic acid (FnA), a stable precursor of folate, with or without methionine restriction. The levels of intracellular AdoHcy and AdoMet, tHcy in the cell culture medium, and protein-incorporated methylarginines were evaluated by suitable liquid chromatography techniques. FnA supplementation, with or without methionine restriction, reduced the level of tHcy and did not affect intracellular AdoMet levels. Interestingly, FnA supplementation reduced intracellular AdoHcy levels only in cells grown under methionine restriction. Furthermore, these cells also displayed increased protein arginine methylation status. These observations suggest that folic acid supplementation may enhance cellular methylation capacity under a low methionine status. Our results lead us to hypothesize that the putative benefits of folic acid supplementation in restoring endothelial homeostasis, thus preventing atherothrombotic events, should be reevaluated in subjects under a methionine restriction diet.

Factors associated with smoking cessation success in Lebanon

Objective:

The objective is to assess factors associated with the success rate of smoking cessation among Lebanese smokers in a smoking cessation center.

Methods:

A cross-sectional data study, conducted between March 2014 and March 2016 in an outpatient smoking cessation center with 156 enrolled patients. The patient’s nicotine dependence and motivation to quit smoking were evaluated according to the Fagerstrom Test for Nicotine Dependence and Richmond tests respectively.

Results:

The number of packs smoked per year decreased the odds of smoking cessation success (p=0.004, ORa=0.982, CI 0.97-0.994), while the compliance with the offered treatment increased the odds of success by 7.68 times (p<0.001, ORa=7.68, CI 3.438-17.187). Highly dependent and highly motivated smokers had more success in the quitting process compared to those with a lower dependence and motivation respectively.

Conclusion:

Our findings showed that many factors can influence smoking cessation, an experience described as difficult, most significantly the number of packs per year and compliance with the smoking cessation treatment. Moreover, although these outcomes are not representative of the entire Lebanese population, we believe that health authorities could utilize these results when implementing upcoming smoking cessations programs. All attempts at cessation should have a goal of reducing the number of packs smoked per year to improve the chances of ceasing into the future.

Epigenetically mediated inhibition of S-adenosylhomocysteine hydrolase and the associated dysregulation of 1-carbon metabolism in nonalcoholic steatohepatitis and hepatocellular carcinoma

The substantial rise in the prevalence of nonalcoholic steatohepatitis (NASH), an advanced form of nonalcoholic fatty liver disease, and the strong association between NASH and the development of hepatocellular carcinoma indicate the urgent need for a better understanding of the underlying mechanisms. In the present study, by using the Stelic animal model of NASH and NASH-derived liver carcinogenesis, we investigated the role of the folate-dependent 1-carbon metabolism in the pathogenesis of NASH. We demonstrated that advanced NASH and NASH-related liver carcinogenesis are characterized by a significant dysregulation of 1-carbon homeostasis, with diminished expression of key 1-carbon metabolism genes, especially a marked inhibition of the S-adenosylhomocysteine hydrolase ( Ahcy) gene and an increased level of S-adenosyl-l-homocysteine (SAH). The reduction in Ahcy expression was associated with gene-specific cytosine DNA hypermethylation and enrichment of the gene promoter by trimethylated histone H3 lysine 27 and deacetylated histone H4 lysine 16, 2 main transcription-inhibiting markers. These results indicate that epigenetically mediated inhibition of Ahcy expression may be a driving force in causing SAH elevation and subsequent downstream disturbances in transsulfuration and transmethylation pathways during the development and progression of NASH.-Pogribny, I. P., Dreval, K., Kindrat, I., Melnyk, S., Jimenez, L., de Conti, A., Tryndyak, V., Pogribna, M., Ortega, J. F., James, S. J., Rusyn, I., Beland, F. A. Epigenetically mediated inhibition of S-adenosylhomocysteine hydrolase and the associated dysregulation of 1-carbon metabolism in nonalcoholic steatohepatitis and hepatocellular carcinoma.

Endothelial Aquaporins and Hypomethylation: Potential Implications for Atherosclerosis and Cardiovascular Disease

Aquaporins (AQPs) are transmembrane channels that facilitate water and glycerol permeation through cell membranes. Recently, the water channel AQP1 was suggested to contribute to endothelial homeostasis and cardiovascular health. Less is known about endothelial aquaglyceroporins expression and its implication in cardiovascular disease (CVD). We have previously used cultured human endothelial cells under a hypomethylating environment to study endothelial dysfunction and activation, a phenotype implicated in the establishment of atherosclerosis and CVD. Here, we used the same cell model to investigate aquaporin’s expression and function in healthy or pro-atherogenic phenotype. We first confirmed key features of endothelium dysfunction and activation in our cell model, including an augmented endothelial transmigration under hypomethylation. Subsequently, we found AQP1 and AQP3 to be the most predominant AQPs accounting for water and glycerol fluxes, respectively, in the healthy endothelium. Moreover, endothelial hypomethylation led to decreased levels of AQP1 and impaired water permeability without affecting AQP3 and glycerol permeability. Furthermore, TNF-α treatment-induced AQP1 downregulation suggesting that the inflammatory NF-κB signaling pathway mediates AQP1 transcriptional repression in a pro-atherogenic endothelium, a possibility that warrants further investigation. In conclusion, our results add further support to AQP1 as a candidate player in the setting of endothelial dysfunction and CVD.