Molecular insights and therapeutic targets for diabetic endothelial dysfunction

Ammar Y, A. Abu Ali O, Ragab A, Mahfoz AM, Abusaif MS. Fluorinated indeno-quinoxaline bearing thiazole moieties as hypoglycaemic agents targeting α-amylase, and α-glucosidase: synthesis, molecular docking, and ADMET studies

Inhibition of α-glucosidase and α-amylase are key tactics for managing blood glucose levels. Currently, stronger, and more accessible inhibitors are needed to treat diabetes. Indeno[1,2-b] quinoxalines-carrying thiazole hybrids 1-17 were created and described using NMR. All analogues were tested for hypoglycaemic effect against STZ-induced diabetes in mice. Compounds 4, 6, 8, and 16 were the most potent among the synthesised analogues. These hybrids were examined for their effects on plasma insulin, urea, creatinine, GSH, MDA, ALT, AST, and total cholesterol. Moreover, these compounds were tested against α-glucosidase and α-amylase enzymes in vitro. The four hybrids 4, 6, 8, and 16 represented moderate to potent activity with IC50 values 0.982 ± 0.04, to 10.19 ± 0.21 for α-glucosidase inhibition and 17.58 ± 0.74 to 121.6 ± 5.14 μM for α-amylase inhibition when compared to the standard medication acarbose with IC50=0.316 ± 0.02 μM for α-glucosidase inhibition and 31.56 ± 1.33 μM for α-amylase inhibition. Docking studies as well as in silico ADMT were done.

Endothelial KLF11 is a novel protector against diabetic atherosclerosis

BACKGROUND

Atherosclerotic cardiovascular diseases remain the leading cause of mortality in diabetic patients, with endothelial cell (EC) dysfunction serving as the initiating step of atherosclerosis, which is exacerbated in diabetes. Krüppel-like factor 11 (KLF11), known for its missense mutations leading to the development of diabetes in humans, has also been identified as a novel protector of vascular homeostasis. However, its role in diabetic atherosclerosis remains unexplored.

METHODS

Diabetic atherosclerosis was induced in both EC-specific KLF11 transgenic and knockout mice in the Ldlr-/- background by feeding a diabetogenic diet with cholesterol (DDC). Single-cell RNA sequencing (scRNA-seq) was utilized to profile EC dysfunction in diabetic atherosclerosis. Additionally, gain- and loss-of-function experiments were conducted to investigate the role of KLF11 in hyperglycemia-induced endothelial cell dysfunction.

RESULTS

We found that endothelial KLF11 deficiency significantly accelerates atherogenesis under diabetic conditions, whereas KLF11 overexpression remarkably inhibits it. scRNA-seq profiling demonstrates that loss of KLF11 increases endothelial-to-mesenchymal transition (EndMT) during atherogenesis under diabetic conditions. Utilizing gain- and loss-of-function approaches, our in vitro study reveals that KLF11 significantly inhibits EC inflammatory activation and TXNIP-induced EC oxidative stress, as well as Notch1/Snail-mediated EndMT under high glucose exposure.

CONCLUSION

Our study demonstrates that endothelial KLF11 is an endogenous protective factor against diabetic atherosclerosis. These findings indicate that manipulating KLF11 could be a promising approach for developing novel therapies for diabetes-related cardiovascular complications.

Association between early blood glucose dynamic trajectory and mortality for critically ill patients with heart failure: Insights from real-world data

AIMS

This study endeavors to explore the ramifications of early dynamic blood glucose (BG) trajectories within the initial 48 h of intensive care unit (ICU) admission on mortality among critically ill heart failure (HF) patients.

METHODS

The study employed a retrospective observational design, analyzing dynamic BG data of HF patients from the Medical Information Mart for Intensive Care IV database. The BG trajectory subphenotypes were identified using the hierarchical clustering based on the dynamic time-warping algorithm. The primary outcome of the study was 28-day mortality, with secondary outcomes including 180-day and 1-year mortality.

RESULTS

We screened a total of 21,098 HF patients and finally 15,092 patients were included in the study. Our results identified three distinct BG trajectory subphenotypes: increasing (n = 3503), stabilizing (n = 6250), and decreasing (n = 5339). The increasing subphenotype was associated with the highest mortality risk at 28 days, 180 days, and 1 year. The stabilizing and decreasing subphenotypes showed significantly lower mortality risks across all time points, with hazard ratios ranging from 0.85 to 0.88 (P<0.05 for all). Sensitivity analyses confirmed the robustness of these findings after adjusting for various covariates.

CONCLUSIONS

Increasing BG trajectory within 48 h of admission is significantly associated with higher mortality in patients with HF. It is necessary to devote greater attention to the early BG dynamic changes in HF patients to optimize clinical BG management and enhance patient prognosis.

Licorice Extract Isoliquiritigenin Protects Endothelial Function in Type 2 Diabetic Mice

Endothelial dysfunction occurs prior to atherosclerosis, which is an independent predictor of cardiovascular diseases (CVDs). Diabetes mellitus impairs endothelial function by triggering oxidative stress and inflammation in vascular tissues. Isoliquiritigenin (ISL), one of the major bioactive ingredients extracted from licorice, has been reported to inhibit inflammation and oxidative stress. However, the therapeutic effects of ISL on ameliorating type 2 diabetes (T2D)-associated endothelial dysfunction remain unknown. In our animal study, db/db male mice were utilized as a model for T2D-associated endothelial dysfunction, while their counterpart, heterozygote db/m+ male mice, served as the control. Mouse brain microvascular endothelial cells (mBMECs) were used for in vitro experiments. Interleukin-1β (IL-1β) was used to induce endothelial cell dysfunction. ISL significantly reversed the impairment of endothelium-dependent relaxations (EDRs) in db/db mouse aortas. ISL treatment decreased ROS (reactive oxygen species) levels in db/db mice aortic sections and IL-1β-treated endothelial cells. Encouragingly, ISL attenuated the overexpression of pro-inflammatory factors MCP-1, TNF-α, and IL-6 in db/db mouse aortas and IL-1β-impaired endothelial cells. The NOX2 (NADPH oxidase 2) overexpression was inhibited by ISL treatment. Notably, ISL treatment restored the expression levels of IL-10, SOD1, Nrf2, and HO-1 in db/db mouse aortas and IL-1β-impaired endothelial cells. This study illustrates, for the first time, that ISL attenuates endothelial dysfunction in T2D mice, offering new insights into the pharmacological effects of ISL. Our findings demonstrate the potential of ISL as a promising therapeutic agent for the treatment of vascular diseases, paving the way for the further exploration of novel vascular therapies.

Differences Between Brachial-Ankle Pulse Wave Velocity and Lower Leg Circumference Ratio in Patients With and Without Type 2 Diabetes Mellitus

Background Vascular endothelial dysfunction in type 2 diabetes mellitus (T2DM) patients causes atherosclerosis and microvascular damage. This study investigated the relationship between leg circumference and arterial stiffness in patients with T2DM compared to non-T2DM individuals. Methods Data from two studies were combined to form T2DM (T2DM group) and non-T2DM (N group) cohorts. The variables included age, sex, systolic blood pressure (SBP), brachial-ankle pulse wave velocity (ba-PWV), ankle-brachial index, height, weight, maximum leg circumference, lower leg circumference ratio, duration of T2DM, Achilles tendon reflex disorder, and the hemoglobin A1c level. Multiple regression analysis was performed with ba-PWV as the dependent variable and the interaction term between leg circumference ratio and T2DM as the independent variable. The control variables included leg circumference ratio, T2DM, SBP, Achilles tendon reflex disorder, age, and sex. IBM SPSS Statistics for Windows, Version 23.0 (Released 2015; IBM Corp., Armonk, NY, USA) was used for the statistical analysis, with the significance level set to p < 0.05. Results The interaction term between the lower leg circumference ratio and T2DM (β = -0.17, 95% CI: -46.11 to -10.92; p < 0.01) was significantly associated with ba-PWV (AdjR² = 0.51, variance inflation factor <4.12). Simple slope analysis indicated that a decreased lower leg circumference ratio was significantly associated with an increased ba-PWV (β = -0.20, p < 0.05) in the T2DM group. No significant relationship was found in the N group (β = -0.03, p = 0.69). Conclusion A significant interaction was found between the lower leg circumference ratio and T2DM presence, indicating an association between ba-PWV and the leg circumference ratio specific to patients with T2DM. This result suggests that the leg circumference ratio can be substituted for the ba-PWV to evaluate arterial stiffness in T2DM.

Syndecan-1 as a prognostic biomarker in COVID-19 patients: a retrospective study of a Japanese cohort

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has had a profound global impact, with millions of confirmed cases and deaths worldwide. While most cases are mild, a subset progresses to severe respiratory complications and death, with factors such as thromboembolism, age, and underlying health conditions increasing the risk. Vascular endothelial damage has been implicated in severe outcomes, but specific biomarkers remain elusive. This study investigated syndecan-1 (SDC-1), a marker of endothelial damage, as a potential prognostic factor for COVID-19, focusing on the Japanese population, which is known for its aging demographics and high prevalence of comorbidities.

METHODS

A multicenter retrospective study of COVID-19 patients in Fukushima Prefecture in Japan who were admitted between February 2020 and August 2021 was conducted. SDC-1 levels were measured along with other clinical and laboratory parameters. Outcomes including thrombosis, 28-day survival, and disease severity were assessed, and disease severity was categorized according to established guidelines.

RESULTS

SDC-1 levels were correlated with disease severity. Patients who died from COVID-19 had greater SDC-1 levels than survivors, and the area under the receiver operating characteristic curve (AUC) analysis suggested the potential of the SDC-1 level as a predictor of mortality (AUC 0.714). K‒M analysis also revealed a significant difference in survival based on an SDC-1 cutoff of 10.65 ng/mL.

DISCUSSION

This study suggested that SDC-1 may serve as a valuable biomarker for assessing COVID-19 severity and predicting mortality within 28 days of hospitalization, particularly in the Japanese population. However, further investigations are required to assess longitudinal changes in SDC-1 levels, validate its predictive value for long-term survival, and consider its applicability to new viral variants.

CONCLUSIONS

SDC-1 is emerging as a potential biomarker for assessing the severity and life expectancy of COVID-19 in the Japanese population, offering promise for improved risk stratification and patient management in the ongoing fight against the virus.

Antioxidant, antidiabetic, and anti-inflammatory activities of flavonoid-rich fractions of Solanum anguivi Lam. fruit: In vitro and ex vivo studies

Diabetes mellitus is a major, rapidly growing endocrine disorder in most countries. The high cost and side effects of conventional drugs for the management of this disease have shifted attention to medicinal plants. Solanum anguivi (S. anguivi) fruits has been reported to be a very good and rich source of polyphenols such as flavonoids, that can be exploited. Flavonoids are plant secondary metabolites widely found in vegetables, fruits and seeds and are known to be of medicinal significance in different range of diseases like diabetes. This study involved in vitro and ex vivo assays on the antioxidant, anti-inflammatory, and antidiabetic properties of flavonoid-rich fractions of S. anguivi fruits. Healthy male Wistar rats (n = 5) weighing 150-180 g were used for ex vivo antioxidant and antidiabetic studies, their liver was exercised for the experiment. The percentage yields of the three flavonoid-rich fractions (Fr. A, B, and C) of S. anguivi fruits obtained from the column chromatographic technique were 15.53 ± 0.75, 11.53 ± 0.80, and 10.17 ± 0.49 mg/g quercetin equivalents. The three fractions (A, B, and C) of S. anguivi fruits significantly scavenged both 2,2-diphenyl-1-picrylhydrazyl (DPPH) with fraction A having the lowest IC50 value (26.14 ± 1.06 μg/ml) compared with fraction B (37.78 ± 5.12 μg/ml) and fraction C (38.24 ± 2.40 μg/ml) when compared with ascorbic acid with the least IC50 value (15.27 ± 0.34 μg/ml). While fraction A (19.61 ± 1.19 μg/ml) scavenged nitric oxide (NO) radicals better than fraction B (22.97 ± 0.55 μg/ml) and fraction C (49.95 ± 6.18 μg/ml). Although ascorbic acid had better scavenging ability than the three fractions (17.23 ± 0.16 μg/ml). The flavonoid-rich fraction A shows better result in inhibiting α-glucosidase with IC50 value of 16.24 μg/ml compared to fraction B (128.04 μg/ml) and fraction C (143.16 μg/ml). For α-amylase, flavonoid-rich fraction A had an IC50 of 31.50 μg/ml compared to B (84.32 μg/ml) and C (145.40 μg/ml). The various controls also showed promising results with acarbose having IC50 of 3.93 μg/mL and 15.66 μg/mL respectively for α-glucosidase and α-amylase. Our findings also showed that FeSO4-induced tissue damage decreased the levels of GSH, SOD, and CAT activities while increasing the levels of MDA. In contrast, following treatment with the three flavonoid fractions of S. anguivi fruits helped to restore these parameters to near-normal levels, by significantly increasing the potential of GSH, SOD, CAT and reducing the levels of MDA which signifies that flavonoid-rich fractions of S. anguivi have great potential to address complications arising from oxidative stress. In addition, the three flavonoid-rich fractions A, B, and C of S. anguivi fruits exhibited ex vivo anti-inflammatory properties via reduced nitric oxide levels in iron-induced oxidative damage. Data obtained from this study shows that the flavonoid-rich fraction of S. anguivi possess anti-diabetic property via inhibition of α-glucosidase and α-amylase and antioxidant property via free radical scavenging. Also, comparing all the fractions, flavonoid-rich fraction A appears to be more potent compared to the fractions B and C. Further research will be needed in isolating and as well applying the fractions in real life situations in the management of diabetes.

Circulating levels of C1q/TNF-α-related protein 6 (CTRP6) in coronary artery disease and its correlation with inflammatory markers

Introduction

Circulating levels of C1q/TNF-α-related protein 6 (CTRP6) is an adipokine that is involved in regulation of glucose and lipid metabolism, inflammation, and insulin sensitivity. However, the exact role of CTRP6 in metabolic processes remains unclear due to conflicting findings. To address current gap, we aimed to investigate the serum levels of CTRP6 in patients with coronary artery disease (CAD) and its association with inflammatory cytokines.

Method

In this case-control study, the serum levels of CTRP6, interlukin-6 (IL-6), tumor necrosis factor- α (TNF-α), adiponectin, and fasting insulin were measured using enzyme-linked immunosorbent assay (ELISA) kits in a total of 176 participants, consisting of 88 CAD patients and 88 control subjects. Additionally, various anthropometric and biochemical measurements were measured and compared between cases and controls.

Results

The present study found that serum levels of CTRP6 were significantly higher in the CAD group (561.3 ± 15.14) compared to the control group (429.3 ± 12.85, p < 0.001). After adjusting for age, sex, and body mass index (BMI), CTRP6 levels were found to be positively associated with the risk of CAD (p < 0.001). Correlation analysis in CAD subjects revealed a positive correlation between CTRP6 levels and BMI, systolic blood pressure (SBP), malondialdehyde (MDA), TNF-α, and IL-6, as well as a negative correlation with creatinine and total anti-oxidant capacity.

Conclusion

The findings of this study provide novel evidence that elevated serum levels of CTRP6 are significantly associated with an increased risk of developing CAD. Moreover, our results indicate a correlation between CTRP6 and various risk factors for atherosclerosis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-024-01415-5.

Activation of heme oxygenase-1 by laminar shear stress ameliorates high glucose-induced endothelial cell and smooth muscle cell dysfunction

High glucose (HG)-induced endothelial cell (EC) and smooth muscle cell (SMC) dysfunction is critical in diabetes-associated atherosclerosis. However, the roles of heme oxygenase-1 (HO-1), a stress-response protein, in hemodynamic force-generated shear stress and HG-induced metabolic stress remain unclear. This investigation examined the cellular effects and mechanisms of HO-1 under physiologically high shear stress (HSS) in HG-treated ECs and adjacent SMCs. We found that exposure of human aortic ECs to HSS significantly increased HO-1 expression; however, this upregulation appeared to be independent of adenosine monophosphate-activated protein kinase, a regulator of HO-1. Furthermore, HSS inhibited the expression of HG-induced intercellular adhesion molecule-1, vascular cell adhesion molecule-1, and reactive oxygen species (ROS) production in ECs. In an EC/SMC co-culture, compared with static conditions, subjecting ECs close to SMCs to HSS and HG significantly suppressed SMC proliferation while increasing the expression of physiological contractile phenotype markers, such as α-smooth muscle actin and serum response factor. Moreover, HSS and HG decreased the expression of vimentin, an atherogenic synthetic phenotypic marker, in SMCs. Transfecting ECs with HO-1-specific small interfering (si)RNA reversed HSS inhibition on HG-induced inflammation and ROS production in ECs. Similarly, reversed HSS inhibition on HG-induced proliferation and synthetic phenotype formation were observed in co-cultured SMCs. Our findings provide insights into the mechanisms underlying EC-SMC interplay during HG-induced metabolic stress. Strategies to promote HSS in the vessel wall, such as continuous exercise, or the development of HO-1 analogs and mimics of the HSS effect, could provide an effective approach for preventing and treating diabetes-related atherosclerotic vascular complications.

Endothelial dysfunction in vascular complications of diabetes: a comprehensive review of mechanisms and implications

Diabetic vascular complications are prevalent and severe among diabetic patients, profoundly affecting both their quality of life and long-term prospects. These complications can be classified into macrovascular and microvascular complications. Under the impact of risk factors such as elevated blood glucose, blood pressure, and cholesterol lipids, the vascular endothelium undergoes endothelial dysfunction, characterized by increased inflammation and oxidative stress, decreased NO biosynthesis, endothelial-mesenchymal transition, senescence, and even cell death. These processes will ultimately lead to macrovascular and microvascular diseases, with macrovascular diseases mainly characterized by atherosclerosis (AS) and microvascular diseases mainly characterized by thickening of the basement membrane. It further indicates a primary contributor to the elevated morbidity and mortality observed in individuals with diabetes. In this review, we will delve into the intricate mechanisms that drive endothelial dysfunction during diabetes progression and its associated vascular complications. Furthermore, we will outline various pharmacotherapies targeting diabetic endothelial dysfunction in the hope of accelerating effective therapeutic drug discovery for early control of diabetes and its vascular complications.

MicroRNA-409-3p/BTG2 signaling axis improves impaired angiogenesis and wound healing in obese mice

Wound healing is facilitated by neoangiogenesis, a complex process that is essential to tissue repair in response to injury. MicroRNAs are small, noncoding RNAs that can regulate the wound healing process including stimulation of impaired angiogenesis that is associated with type-2 diabetes (T2D). Expression of miR-409-3p was significantly increased in the nonhealing skin wounds of patients with T2D compared to the non-wounded normal skin, and in the skin of a murine model with T2D. In response to high glucose, neutralization of miR-409-3p markedly improved EC growth and migration in human umbilical vein endothelial cells (HUVECs), promoted wound closure and angiogenesis as measured by increased CD31 in human skin organoids, while overexpression attenuated EC angiogenic responses. Bulk mRNA-Seq transcriptomic profiling revealed BTG2 as a target of miR-409-3p, where overexpression of miR-409-3p significantly decreased BTG2 mRNA and protein expression. A 3' untranslated region (3'-UTR) luciferase assay of BTG2 revealed decreased luciferase activity with overexpression of miR-409-3p, while inhibition had opposite effects. Mechanistically, in response to high glucose, miR-409-3p deficiency in ECs resulted in increased mTOR phosphorylation, meanwhile BTG-anti-proliferation factor 2 (BTG2) silencing significantly decreased mTOR phosphorylation. Endothelial-specific and tamoxifen-inducible miR-409-3p knockout mice (MiR-409IndECKO ) with hyperglycemia that underwent dorsal skin wounding showed significant improvement of wound closure, increased blood flow, granulation tissue thickness (GTT), and CD31 that correlated with increased BTG2 expression. Taken together, our results show that miR-409-3p is a critical mediator of impaired angiogenesis in diabetic skin wound healing.

Predictors of non-obstructive coronary slow flow in poorly controlled type 2 diabetes mellitus: a cross-sectional study

BACKGROUND

Coronary slow flow (CSF) can occur due to various factors, such as inflammation, small vessel disease, endothelial dysfunction, and inadequate glucose control. However, the exact pathological mechanisms behind CSF remain incompletely understood. The objective of this study was to identify the risk factors associated with slow coronary flow in individuals with Type 2 Diabetes Mellitus (T2DM) who have non-obstructive coronary artery disease (CAD) and experience CSF.

METHODS

We conducted a prospective cohort study involving 120 patients with T2DM who were referred for invasive coronary angiography due to typical chest pain or inconclusive results from non-invasive tests for myocardial ischemia. Using a 2 × 2 design, we categorized patients into groups based on their glycemic control (adequate or poor) and the presence of CSF (yes or no), defined by a TIMI frame count > 27. All patients had non-obstructive CAD, characterized by diameter stenosis of less than 40%. We identified many variables associated with CSF.

RESULTS

Our investigation revealed no significant differences in age, sex, family history of coronary artery disease, ECG ischemia abnormalities, or echocardiographic (ECHO) data between the groups. In patients with adequate glycemic control, hypertension increased the risk of CSF by 5.33 times, smoking by 3.2 times, while dyslipidemia decreased the risk by 0.142. Additionally, hematocrit increased the risk by 2.3, and the platelet-to-lymphocyte ratio (PLR) increased the risk by 1.053. Among patients with poor glycemic control, hematocrit increased the risk by 2.63, and the Neutrophil-to-Lymphocyte Ratio (NLR) by 24.6. Notably, NLR was positively correlated with glycemic control parameters in T2DM patients with CSF.

CONCLUSIONS

In T2DM patients with CSF, various factors strongly correlate with glycemic control parameters and can be employed to predict the likelihood of CSF. These factors encompass hypertension, smoking, increased body mass index (BMI), elevated platelet count, hematocrit, NLR, PLR, and C-reactive protein (CRP).

TRIAL REGISTRATION

Registry: ZU-IRB (ZU-IRB#9419-3-4-2022), Registered on: 3 April 2022, Email: IRB_123@medicine.zu.edu.eg.

SGLT2 inhibitor improves the prognosis of patients with coronary heart disease and prevents in-stent restenosis

Coronary heart disease is a narrowing or obstruction of the vascular cavity caused by atherosclerosis of the coronary arteries, which leads to myocardial ischemia and hypoxia. At present, percutaneous coronary intervention (PCI) is an effective treatment for coronary atherosclerotic heart disease. Restenosis is the main limiting factor of the long-term success of PCI, and it is also a difficult problem in the field of intervention. Sodium-glucose cotransporter 2 (SGLT2) inhibitor is a new oral glucose-lowering agent used in the treatment of diabetes in recent years. Recent studies have shown that SGLT2 inhibitors can effectively improve the prognosis of patients after PCI and reduce the occurrence of restenosis. This review provides an overview of the clinical studies and mechanisms of SGLT2 inhibitors in the prevention of restenosis, providing a new option for improving the clinical prognosis of patients after PCI.

Protective effect of ellagic acid against high-glucose-induced injury in human umbilical venous endothelial cells

Objective

There is escalating evidence suggesting the beneficial effects of ellagic acid (EA) on the cardiovascular system. The aim of the present study was to investigate the protective effect of EA in human umbilical vein endothelial cells (HUVECs) against high glucose (HG)- induced endothelial dysfunction and to study the potential roles of adropin and nitric oxide (NO) in this regard.

Materials and Methods

The experimental groups consisted of normal and HG (30 mM, 48 hr)-treated HUVECs incubated without or with 5 or 10 μM of EA (6 groups of at least 6 replicates, each). The cell count and viability were studied. Moreover, the markers of the redox state, including malondialdehyde (MDA), the activities of superoxide dismutase (SOD) and catalase enzymes, and ferric reducing anti-oxidant power (FRAP), were assayed. The levels of adropin and eNOS gene expression were also studied using RT-qPCR.

Results

A high concentration of glucose reduced cell count and caused lipid peroxidation, reduced anti-oxidant capacity of the cells, decreased NO levels, and downregulated the expression of NOS3 (encoding eNOS) and ENHO (encoding adropin) genes. Ellagic acid reversed all these effects.

Conclusion

These results suggest a significant protective effect for EA against HG-induced injury in HUVECs. The improved redox state and upregulation of NOS3 and ENHO genes seem to play critical roles in this regard.

Neuraminidase inhibition improves endothelial function in diabetic mice

Neuraminidases cleave sialic acids from glycocalyx structures and plasma neuraminidase activity is elevated in type 2 diabetes (T2D). Therefore, we hypothesize circulating neuraminidase degrades the endothelial glycocalyx and diminishes flow-mediated dilation (FMD), whereas its inhibition restores shear mechanosensation and endothelial function in T2D settings. We found that compared with controls, subjects with T2D have higher plasma neuraminidase activity, reduced plasma nitrite concentrations, and diminished FMD. Ex vivo and in vivo neuraminidase exposure diminished FMD and reduced endothelial glycocalyx presence in mouse arteries. In cultured endothelial cells, neuraminidase reduced glycocalyx coverage. Inhalation of the neuraminidase inhibitor, zanamivir, reduced plasma neuraminidase activity, enhanced endothelial glycocalyx length, and improved FMD in diabetic mice. In humans, a single-arm trial (NCT04867707) of zanamivir inhalation did not reduce plasma neuraminidase activity, improved glycocalyx length, or enhanced FMD. Although zanamivir plasma concentrations in mice reached 225.8 ± 22.0 ng/mL, in humans were only 40.0 ± 7.2 ng/mL. These results highlight the potential of neuraminidase inhibition for ameliorating endothelial dysfunction in T2D and suggest the current Food and Drug Administration-approved inhaled dosage of zanamivir is insufficient to achieve desired outcomes in humans.NEW & NOTEWORTHY This work identifies neuraminidase as a key mediator of endothelial dysfunction in type 2 diabetes that may serve as a biomarker for impaired endothelial function and predictive of development and progression of cardiovascular pathologies associated with type 2 diabetes (T2D). Data show that intervention with the neuraminidase inhibitor zanamivir at effective plasma concentrations may represent a novel pharmacological strategy for restoring the glycocalyx and ameliorating endothelial dysfunction.

Advances in Fabrication Technologies for the Development of Next-Generation Cardiovascular Stents

Coronary artery disease is the most prevalent cardiovascular disease, claiming millions of lives annually around the world. The current treatment includes surgically inserting a tubular construct, called a stent, inside arteries to restore blood flow. However, due to lack of patient-specific design, the commercial products cannot be used with different vessel anatomies. In this review, we have summarized the drawbacks in existing commercial metal stents which face problems of restenosis and inflammatory responses, owing to the development of neointimal hyperplasia. Further, we have highlighted the fabrication of stents using biodegradable polymers, which can circumvent most of the existing limitations. In this regard, we elaborated on the utilization of new fabrication methodologies based on additive manufacturing such as three-dimensional printing to design patient-specific stents. Finally, we have discussed the functionalization of these stent surfaces with suitable bioactive molecules which can prove to enhance their properties in preventing thrombosis and better healing of injured blood vessel lining.

An ischemic area-targeting, peroxynitrite-responsive, biomimetic carbon monoxide nanogenerator for preventing myocardial ischemia-reperfusion injury

Myocardial ischemia-reperfusion (MI/R) injury is common in patients who undergo revascularization therapy for myocardial infarction, often leading to cardiac dysfunction. Carbon monoxide (CO) has emerged as a therapeutic molecule due to its beneficial properties such as anti-inflammatory, anti-apoptotic, and mitochondrial biogenesis-promoting properties. However, its clinical application is limited due to uncontrolled release, potential toxicity, and poor targeting efficiency. To address these limitations, a peroxynitrite (ONOO^-)-triggered CO donor (PCOD585) is utilized to generate a poly (lactic-co-glycolic acid) (PLGA)-based, biomimetic CO nanogenerator (M/PCOD@PLGA) that is coated with the macrophage membrane, which could target to the ischemic area and neutralize proinflammatory cytokines. In the ischemic area, local produced ONOO^- triggers the continuous release of CO from M/PCOD@PLGA, which efficiently ameliorates MI/R injury by clearing harmful ONOO^-, attenuating the inflammatory response, inhibiting cardiomyocyte apoptosis, and promoting mitochondrial biogenesis. This study provides a novel insight into the safe therapeutic use of CO for MI/R injury by utilizing a novel CO donor combined with biomimetic technology. The M/PCOD@PLGA nanogenerator offers targeted delivery of CO to the ischemic area, minimizing potential toxicity and enhancing therapeutic efficacy.

Association between glycated hemoglobin and functional outcomes in patients with intracranial large artery atherosclerotic disease-related acute ischemic stroke: identifying the magic number

Objective

This study aimed to investigate the effect of the glycated hemoglobin A1c (HbA1c) level on the functional outcome (FOC) in patients with intracranial large artery atherosclerotic disease (ICLAD)-related acute ischemic stroke (AIS).

Methods

This retrospective study enrolled patients with ICLAD-related AIS who were admitted to King Fahd University Hospital between January 2017 and September 2021. Patients were divided into two groups based on the optimal cutoff HbA1c level determined using receiver operating characteristic curve analysis-those with HbA1c ≤6.9% and those with HbA1c >6.9%. Demographic and other clinical characteristics were compared between the two groups using chi-square tests. The association between HbA1c and 90-day FOC was assessed using the chi-square test and odds ratios (ORs). Multivariate analysis was performed to adjust for confounding factors.

Results

A total of 140 patients were included in the analysis. A significant association was observed between the HbA1c level and FOC. Compared to patients with HbA1c ≤6.9%, patients with HbA1c >6.9% were more likely to have an unfavorable FOC [p = <0.001, OR = 2.05, 95% confidence interval (CI) = 1.33-3.14]. The association between HbA1c >6.9% and unfavorable FOC was sustained even after adjusting for confounding factors (p = 0.008) and atherosclerosis risk factors (p = 0.01). HbA1c >6.9% was also associated with higher ORs for in-hospital complications (p = 0.06, OR = 1.34, 95% CI = 1.02-1.77) and mortality (p = 0.07, OR = 1.42, 95% CI = 1.06-1.92) although these associations did not attain significant p-values.

Conclusion

HbA1c >6.9% was significantly associated with unfavorable FOC in ICLAD-related AIS. However, further studies with larger sample sizes are required to verify whether HbA1c is an independent predictor of poor FOC. Nevertheless, targeting HbA1c <7% should be the goal of physicians when managing patients at high risk of ICLAD.

Ameliorating diabetes-associated atherosclerosis and diabetic nephropathy through modulation of soluble guanylate cyclase

Diabetes mellitus (DM) is an independent risk factor for micro- and macrovascular complications such as nephropathy and atherosclerosis respectively, which are the major causes of premature morbidity and mortality in Type 1 and Type 2 diabetic patients. Endothelial dysfunction is the critical first step of vascular disease and is characterized by reduced bioavailability of the essential endothelial vasodilator, nitric oxide (NO), coupled with an elevation in inflammation and oxidative stress. A novel pathway to bolster NO activity is to upregulate soluble guanylate cyclase (sGC), an enzyme responsible for mediating the protective actions of NO. Two classes of sGC modulators exist, activators and stimulators, with differing sensitivity to oxidative stress. In this study, we investigated the therapeutic effects of the sGC stimulator BAY 41-2272 (Bay 41) and the sGC activator BAY 60-2770 (Bay 60) on endpoints of atherosclerosis and renal disease as well as inflammation and oxidative stress in diabetic Apolipoprotein E knockout (ApoE-/-) mice. We hypothesized that under oxidative conditions known to accompany diabetes, sGC activation might be more efficacious than sGC stimulation in limiting diabetic vascular complications. We demonstrate that Bay 60 not only significantly decreased nitrotyrosine staining (P < 0.01) and F4/80 positive cells by 75% (P < 0.05), but it also significantly reduced total plaque area (P < 0.05) and improved endothelial function (P < 0.01). Our data suggest an important anti-atherogenic role for Bay 60 accompanied by reduced oxidative stress and inflammation under diabetic settings. Treatment with the stimulator Bay 41, on the other hand, had minimal effects or caused no changes with respect to cardiovascular or renal pathology. In the kidneys, treatment with Bay 60 significantly lessened urinary albuminuria, mesangial expansion and nitrotyrosine staining under diabetic conditions. In summary, our head-to-head comparator is the first preclinical study to show that a sGC activator is more efficacious than a sGC stimulator for the treatment of diabetes-associated vascular and renal complications.

Impact of Glycemic Control on Coronary Inflammation Evaluated by Computed Tomography Pericoronary Fat Attenuation Index in Patients with Acute Coronary Syndrome

Background

Coronary inflammation causes significantly increased risk of cardiovascular disease (CVD) in diabetic patients. This study investigated the relationship between coronary local inflammation, detected by pericoronary fat attenuation index (FAI), and different blood glucose control levels in low-risk acute coronary syndrome (ACS) patients with or without diabetes.

Methods

A total of 309 patients with low-risk ACS were classified into three groups: non-diabetes, well-regulated diabetes, and poorly regulated diabetes. Pericoronary FAI around the proximal or left anterior descending artery (LAD), left circumflex artery (LCX), and right coronary artery (RCA), were evaluated by coronary computed tomography angiography (CCTA), and systemic inflammatory variables and other biochemical indicators were detected by flow cytometry.

Results

Pericoronary FAI values around the proximal LAD, LCX, and RCA in poorly regulated diabetes were significantly higher than those in well-regulated diabetes and non-diabetes, whereas those in well-regulated diabetes were not statistically different from those in non-diabetes. Further, plasma glycated hemoglobin (HbA1c) level was positively correlated with the pericoronary FAI values in LAD, LCX, and RCA. However, no significantly increased systemic inflammatory mediators were found in diabetic patients with poor glycemic control.

Conclusions

Diabetic patients with poor glycemic control may have higher coronary local inflammation as detected by pericoronary FAI surrounding the three major coronary arteries.

Clinical Trial Registration

NCT05590858.

ETV2 Enhances CXCL5 Secretion from Endothelial Cells, Leading to the Promotion of Vascular Smooth Muscle Cell Migration

Abnormal communication between endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) promotes vascular diseases, including atherogenesis. ETS variant transcription factor 2 (ETV2) plays a substantial role in pathological angiogenesis and the reprogramming of ECs; however, the role of ETV2 in the communication between ECs and VSMCs has not been revealed. To investigate the interactive role of ETV2 in the EC to VSMC phenotype, we first showed that treatment with a conditioned medium from ETV2-overexpressed ECs (Ad-ETV2 CM) significantly increased VSMC migration. The cytokine array showed altered levels of several cytokines in Ad-ETV2 CM compared with those in normal CM. We found that C-X-C motif chemokine 5 (CXCL5) promoted VSMC migration using the Boyden chamber and wound healing assays. In addition, an inhibitor of C-X-C motif chemokine receptor 2 (CXCR2) (the receptor for CXCL5) significantly inhibited this process. Gelatin zymography showed that the activities of matrix metalloproteinase (MMP)-2 and MMP-9 increased in the media of VSMCs treated with Ad-ETV2 CM. Western blotting revealed a positive correlation between Akt/p38/c-Jun phosphorylation and CXCL5 concentration. The inhibition of Akt and p38-c-Jun effectively blocked CXCL5-induced VSMC migration. In conclusion, CXCL5 from ECs induced by ETV2 promotes VSMC migration via MMP upregulation and the activation of Akt and p38/c-Jun.

Relationship between inflammatory markers and coronary slow flow in type 2 diabetic patients

BACKGROUND

Diabetes is a serious and quickly expanding global health problem. Cardiovascular disease is the leading cause of mortality in type 2 diabetes mellitus (T2DM) patients. Coronary slow flow (CSF) is characterised by delayed distal perfusion during coronary angiography with normal coronary arteries. This study aimed to investigate the correlation between CSF and inflammatory markers regarding glycemic status in T2DM.

METHODS

This cross-sectional study included 120 patients who were divided equally into 4 groups according to their glycemic control and presence or absence of coronary slow flow: Group I included patients with T2DM with good glycemic control without CSF; Group II included patients with T2DM with good glycemic control and CSF; Group III included patients with T2DM with poor glycemic control without CSF; and Group IV included patients with T2DM with poor glycemic control and CSF. The neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), C-reactive protein (CRP), platelets, hematocrit, and haemoglobin were also evaluated as risk factors for coronary slow flow.

RESULTS

This study showed that body mass index (BMI), hematocrit level, NLR, and CRP demonstrated a moderate but significant correlation (r = 0.53) with CSF in poorly controlled T2DM. NLR cutoff > 2.1 could predict CSF in poorly controlled T2DM with a modest sensitivity and specificity. A 1.9 increase in HbA1c increases the likelihood of coronary slow flow. Dylipidemia increases the likelihood of coronary slow flow by 0.18 times. Other predictors for coronary slow flow include NLR, PLR, CRP, platelets, hematocrit, and hemoglobin. The effect of the predictors is still statistically significant after being adjusted for glycemic status, age, and sex (p < 0.001).

CONCLUSIONS

Poor glycemic control increases the incidence of CSF. This supports the hypothesis that CSF is related to endothelial dysfunction as poor glycemic control causes endothelial dysfunction due to inflammation.

TRIAL REGISTRATION

ZU-IRB#9419-3-4-2022 Registered 3 April 2022, email.  IRB_123@medicine.zu.edu.eg .

Down-regulation of WWP2 aggravates Type 2 diabetes mellitus-induced vascular endothelial injury through modulating ubiquitination and degradation of DDX3X

BACKGROUND

Endothelial injury caused by Type 2 diabetes mellitus (T2DM) is considered as a mainstay in the pathophysiology of diabetic vascular complications (DVCs). However, the molecular mechanism of T2DM-induced endothelial injury remains largely unknown. Here, we found that endothelial WW domain-containing E3 ubiquitin protein ligase 2 (WWP2) act as a novel regulator for T2DM-induced vascular endothelial injury through modulating ubiquitination and degradation of DEAD-box helicase 3 X-linked (DDX3X).

METHODS

Single-cell transcriptome analysis was used to evaluate WWP2 expression in vascular endothelial cells of T2DM patients and healthy controls. Endothelial-specific Wwp2 knockout mice were used to investigate the effect of WWP2 on T2DM-induced vascular endothelial injury. In vitro loss- and gain-of-function studies were performed to assess the function of WWP2 on cell proliferation and apoptosis of human umbilical vein endothelial cells. The substrate protein of WWP2 was verified using mass spectrometry, coimmunoprecipitation assays and immunofluorescence assays. The mechanism of WWP2 regulation on substrate protein was investigated by pulse-chase assay and ubiquitination assay.

RESULTS

The expression of WWP2 was significantly down-regulated in vascular endothelial cells during T2DM. Endothelial-specific Wwp2 knockout in mice significantly aggravated T2DM-induced vascular endothelial injury and vascular remodeling after endothelial injury. Our in vitro experiments showed that WWP2 protected against endothelial injury by promoting cell proliferation and inhibiting apoptosis in ECs. Mechanically, we found that WWP2 is down-regulated in high glucose and palmitic acid (HG/PA)-induced ECs due to c-Jun N-terminal kinase (JNK) activation, and uncovered that WWP2 suppresses HG/PA-induced endothelial injury by catalyzing K63-linked polyubiquitination of DDX3X and targeting it for proteasomal degradation.

CONCLUSION

Our studies revealed the key role of endothelial WWP2 and the fundamental importance of the JNK-WWP2-DDX3X regulatory axis in T2DM-induced vascular endothelial injury, suggesting that WWP2 may serve as a new therapeutic target for DVCs.

The beneficial effects of astragaloside IV on ameliorating diabetic kidney disease

Diabetic kidney disease (DKD) has become the major cause of chronic kidney disease or end-stage renal disease. There is still a need for innovative treatment strategies for preventing, arresting, treating, and reversing DKD, and a plethora of scientific evidence has revealed that Chinese herbal monomers can attenuate DKD in multiple ways. Astragaloside IV (AS-IV) is one of the active ingredients of Astragalus membranaceus and was selected as a chemical marker in the Chinese Pharmacopeia for quality control purposes. An increasing amount of studies indicate that AS-IV is a promising novel drug for the treatment of DKD. AS-IV has been shown to improve DKD by combating oxidative stress, attenuating endoplasmic reticulum stress, regulating calcium homeostasis, alleviating inflammation, improving vascular function, improving epithelial to mesenchymal transition and so on. This review briefly summarizes the pathogenesis of DKD, systematically reviews the mechanisms by which AS-IV improves DKD, and aims to facilitate related pharmacological research and development to promote the utilization of Chinese herbal monomers in DKD.

Effect of Low Protein Diet Supplemented with Ketoanalogs on Endothelial Function and Protein-Bound Uremic Toxins in Patients with Chronic Kidney Disease

Studies have demonstrated that a low-protein diet supplemented with ketoanalogs (KAs) could significantly retard progression of renal function in patients with chronic kidney disease (CKD) stages 3-5. However, its effects on endothelial function and serum levels of protein-bound uremic toxins remain elusive. Therefore, this study explored whether a low-protein diet (LPD) supplemented with KAs affects kidney function, endothelial function, and serum uremic toxin levels in a CKD-based cohort. In this retrospective cohort, we enrolled 22 stable CKD stage 3b-4 patients on LPD (0.6-0.8 g/day). Patients were categorized into control (LPD only) and study groups (LPD + KAs 6 tab/day). Serum biochemistry, total/free indoxyl sulfate (TIS/FIS), total/free p-cresyl sulfate (TPCS/FPCS), and flow-mediated dilation (FMD) were measured before and after 6 months of KA supplementation. Before the trial, there were no significant differences in kidney function, FMD, or uremic toxin levels between the control and study groups. When compared with the control group, the paired t-test showed a significant decrease in TIS and FIS (all p < 0.05) and a significant increase in FMD, eGFR, and bicarbonate (all p < 0.05). In multivariate regression analysis, an increase in FMD (p < 0.001) and a decrease in FPCS (p = 0.012) and TIS (p < 0.001) remained persistent findings when adjusted for age, systolic blood pressure (SBP), sodium, albumin, and diastolic blood pressure (DBP). LPD supplemented with KAs significantly preserves kidney function and provides additional benefits on endothelial function and protein-bound uremic toxins in patients with CKD.

Stem cell-derived exosomes from human exfoliated deciduous teeth promote angiogenesis in hyperglycemic-induced human umbilical vein endothelial cells

OBJECTIVE

To investigate the angiogenesis in human umbilical vein endothelial cells (HUVEC) under high glucose concentration, treated with exosomes derived from stem cells from human exfoliated deciduous teeth (SHED).

METHODOLOGY

SHED-derived exosomes were isolated by differential centrifugation and were characterized by nanoparticle tracking analysis, transmission electron microscopy, and flow cytometric assays. We conducted in vitro experiments to examine the angiogenesis in HUVEC under high glucose concentration. Cell Counting Kit-8, migration assay, tube formation assay, quantitative real-time PCR, and immunostaining were performed to study the role of SHED-derived exosomes in cell proliferation, migration, and angiogenic activities.

RESULTS

The characterization confirmed SHED-derived exosomes: size ranged from 60-150 nm with a mode of 134 nm, cup-shaped morphology, and stained positively for CD9, CD63, and CD81. SHED-exosome significantly enhanced the proliferation and migration of high glucose-treated HUVEC. A significant reduction was observed in tube formation and a weak CD31 staining compared to the untreated-hyperglycemic-induced group. Interestingly, exosome treatment improved tube formation qualitatively and demonstrated a significant increase in tube formation in the covered area, total branching points, total tube length, and total loop parameters. Moreover, SHED-exosome upregulates angiogenesis-related factors, including the GATA2 gene and CD31 protein.

CONCLUSIONS

Our data suggest that the use of SHED-derived exosomes potentially increases angiogenesis in HUVEC under hyperglycemic conditions, which includes increased cell proliferation, migration, tubular structures formation, GATA2 gene, and CD31 protein expression. SHED-exosome usage may provide a new treatment strategy for periodontal patients with diabetes mellitus.

Tripeptide IRW Improves AMPK/eNOS Signaling Pathway via Activating ACE2 in the Aorta of High-Fat-Diet-Fed C57BL/6 Mice

This study aims to investigate the effect of tripeptide IRW on the local renin–angiotensin system (RAS), particularly angiotensin-converting enzyme 2 (ACE2), and their association with signaling pathways in the aorta of a high-fat-diet (HFD)-induced insulin-resistant mouse model. C57BL/6 mice were fed HFD (45% of the total calories) for six weeks, and then IRW was added to the diet (45 mg/kg body weight (BW)) for another eight weeks. ACE2 mRNA expression and protein level(s) were increased (p < 0.05), while angiotensin II receptor (AT1R) and angiotensin-converting enzyme (ACE) protein abundance was significantly reduced (p < 0.05) in the aorta of HFD mice treated by IRW. IRW supplementation also improved glucose transporter 4 (GLUT4) abundance (p < 0.05) alongside AMP-activated protein kinase (AMPK) (p < 0.05), Sirtuin 1 (SIRT1) (p < 0.05), and endothelial nitric oxide synthase (eNOS) (p < 0.05) expression. IRW downregulated the levels of endothelin 1 (ET-1) and p38 mitogen-activated protein kinases (p38 MAPK, p < 0.05). Furthermore, the levels of AMPK and eNOS in vascular smooth muscle cells (VSMCs) were significantly reduced in ACE2 knockdown cells treated with or without IRW (p < 0.01). In conclusion, this study provided new evidence of the regulatory role of IRW on the aortic ACE2 against metabolic syndrome (MetS) in an HFD-induced insulin-resistant model.

Reactive Oxygen Species in the Aorta and Perivascular Adipose Tissue Precedes Endothelial Dysfunction in the Aorta of Mice with a High-Fat High-Sucrose Diet and Additional Factors

Metabolic syndrome (Mets) is the major contributor to the onset of metabolic complications, such as hypertension, type 2 diabetes mellitus (DM), dyslipidemia, and non-alcoholic fatty liver disease, resulting in cardiovascular diseases. C57BL/6 mice on a high-fat and high-sucrose diet (HFHSD) are a well-established model of Mets but have minor endothelial dysfunction in isolated aortas without perivascular adipose tissue (PVAT). The purpose of this study was to evaluate the effects of additional factors such as DM, dyslipidemia, and steatohepatitis on endothelial dysfunction in aortas without PVAT. Here, we employed eight-week-old male C57BL/6 mice fed with a normal diet (ND), HFHSD, steatohepatitis choline-deficient HFHSD (HFHSD-SH), and HFHSD containing 1% cholesterol and 0.1% deoxycholic acid (HFHSD-Chol) for 16 weeks. At week 20, some HFHSD-fed mice were treated with streptozocin to develop diabetes (HFHSD-DM). In PVAT-free aortas, the endothelial-dependent relaxation (EDR) did not differ between ND and HFHSD (p = 0.25), but in aortas with PVAT, the EDR of HFHSD-fed mice was impaired compared with ND-fed mice (p = 0.005). HFHSD-DM, HFHSD-SH, and HFHSD-Chol impaired the EDR in aortas without PVAT (p < 0.001, p = 0.019, and p = 0.009 vs. ND, respectively). Furthermore, tempol rescued the EDR in those models. In the Mets model, the EDR is compromised by PVAT, but with the addition of DM, dyslipidemia, and SH, the vessels themselves may result in impaired EDR.

Scavenger receptor a mediates glycated LDL transcytosis across endothelial cells to promote atherosclerosis

Glycated low-density lipoprotein (G-LDL) is an established proatherosclerotic factor, but the mechanism is not completely understood. In vitro, we evaluated the uptake and transcytosis rates of N-LDL and G-LDL in endothelial cells and the uptake and transcytosis rates of G-LDL were much higher than those of N-LDL. Then, using small interfering RNAs, the receptor mediating G-LDL uptake and transcytosis was screened among eight candidate receptors, and the mechanism of the receptor regulation was thoroughly examined. We discovered that scavenger receptor A (SR-A) knockdown dramatically decreased the uptake and transcytosis rates of G-LDL. Additionally, endothelial cells with overexpressed SR-A had enhanced G-LDL uptake and transcytosis. In vivo, G-LDL was injected in the tail vein of ApoE^-/- mice to investigate whether G-LDL affects atherosclerotic plaque formation. Compared with the injection of N-LDL, the injection of G-LDL accelerated atherosclerotic plaque formation in ApoE^-/- mice, which was ameliorated by endothelial cells specific SR-A knockdown. Together, our results provide the first demonstration that the transcytosis of G-LDL across endothelial cells is much faster than that of N-LDL and SR-A is the major type of receptor responsible for G-LDL binding and transcytosis across endothelial cells.

Structurally diverse polycyclic polyprenylated acylphloroglucinols with protective effect on human vein endothelial cells injured by high-glucose from Hypericum acmosepalum N. Robson

Hyperacmotone A, a polycyclic polyprenylated acylphloroglucinol (PPAP) with an unprecedented skeleton, along with five undescribed congeners and eleven reported ones, was isolated from Hypericum acmosepalum. Hyperacmotone A possesses a unique monocyclic ring skeleton based on a cyclopent-4-ene-1,3-dione acylphloroglucinol core. Their structures were elucidated by extensive analysis of HRESIMS, NMR, biogenetic pathway, and quantum-chemical calculations. In addition, hypercohone G exhibited significant protective effects on high-glucose-injured HUVECs.

Canagliflozin Inhibits Human Endothelial Cell Inflammation through the Induction of Heme Oxygenase-1

Sodium-glucose co-transporter 2 (SGLT2) inhibitors improve cardiovascular outcomes in patients with type 2 diabetes mellitus (T2DM). Studies have also shown that canagliflozin directly acts on endothelial cells (ECs). Since heme oxygenase-1 (HO-1) is an established modulator of EC function, we investigated if canagliflozin regulates the endothelial expression of HO-1, and if this enzyme influences the biological actions of canagliflozin in these cells. Treatment of human ECs with canagliflozin stimulated a concentration- and time-dependent increase in HO-1 that was associated with a significant increase in HO activity. Canagliflozin also evoked a concentration-dependent blockade of EC proliferation, DNA synthesis, and migration that was unaffected by inhibition of HO-1 activity and/or expression. Exposure of ECs to a diabetic environment increased the adhesion of monocytes to ECs, and this was attenuated by canagliflozin. Knockdown of HO-1 reduced the anti-inflammatory effect of canagliflozin which was restored by bilirubin but not carbon monoxide. In conclusion, this study identified canagliflozin as a novel inducer of HO-1 in human ECs. It also found that HO-1-derived bilirubin contributed to the anti-inflammatory action of canagliflozin, but not the anti-proliferative and antimigratory effects of the drug. The ability of canagliflozin to regulate HO-1 expression and EC function may contribute to the clinical profile of the drug.

Preparation of thermo-responsive polymer encapsulated exosomes and its role as a therapeutic agent for blood clot lysis

Tissue plasminogen activators induce enzymatic activation of plasminogen to plasmin that cleaves fibrin strands in blood clots. In the present study, extracellular vesicles such as exosomes from fibrosarcoma cell line HT1080 were utilized as clot-busting agents. These exosomes were being used for clot lysis of whole blood which showed 28% lysis within 10 h, which was comparable to that of the streptokinase (commercial plasmin activator) with no significant difference. These exosomes were able to facilitate the migration of endothelial cells in a scratch wound assay where normalized wound area remaining was 7.5% at 18 h. Also, exosomes aided in attenuation of oxidative stress generated on the cells, thereby maintaining cell viability. These exosomes were further encapsulated in a thermo-responsive polymer for better localized delivery that showed no cytotoxic effects, and sustained delivery was achieved up to a concentration of 117 µg/mL in 25 days, which corresponds to around 65% of the total amount of exosomes added. When a combination of exosomes and thermo-responsive polymer was utilized, the clot lysis activity reached to around 22% in 72 h. Thus, it proves the potential of this combinatorial approach which can be effectively used for thrombus degradation and healing of endothelium lining in damaged blood vessels.

Divergent effect of blood glucose dysregulation on long-term clinical outcome in acute decompensated heart failure: A reappraisal in contemporary practice

BACKGROUND

The prognostic implication of elevated or decreased blood glucose (BG) level in acute decompensated heart failure (ADHF) has been still controversial. Indices of stress hyperglycemia, expressed by the ratio of BG and chronic BG control, has been reported to be associated with poor outcome in different disease population. We sought to assess BG at admission and %ΔBG, an index of BG deviation from estimated average BG calculated from glycated hemoglobin (HbA1c), on the long-term outcome in ADHF patients.

METHODS AND RESULTS

The West Tokyo Heart Failure (WET-HF) Registry is a prospective multicenter registry enrolling consecutive hospitalized ADHF patients. Among the patients (N = 3078, 77 [67-84] years, male 59%), BG at admission discriminated the long-term (1000 days) incidence of ADHF rehospitalization, but not cardiac death. BG at admission showed a U-shape relationship with the long-term incidence of ADHF rehospitalization after adjustment for covariates. Especially, in patients with HbA1c ≥ 6.5%, the lowest quartile showed the highest risk of ADHF rehospitalization. On the contrary, %ΔBG showed U-shape relationship with the long-term incidence of cardiac death after discharge, rather than ADHF rehospitalization after adjustment for covariates. In addition, elevated %ΔBG was associated with the long-term risk of sudden cardiac death (SCD) even after adjustment for covariates.

CONCLUSIONS

For ADHF patients, BG at admission and %ΔBG might be a simple, useful tool for predicting and stratifying long-term risk of cardiac events. Especially, elevated %ΔBG might be an important in predicting hard events such as cardiac death or SCD.

Total White Blood Cell Count is Associated with Arterial Stiffness Among Hypertensive Patients

The association between white blood cell (WBC) count and arterial stiffness in patients with hypertension is not well-documented. We aimed to examine the relationships of total WBC count with arterial stiffness and risk of macrovascular damage in hypertensive patients. A total of 631 hypertensive adults (mean age: 65.6 years) were included in the present study. Arterial stiffness was determined by brachial-ankle pulse wave velocity (baPWV) and ankle-brachial index (ABI). Macrovascular damage was defined as baPWV >1.8 m/s or ABI <.9. The dose-response associations were assessed by multivariate linear or logistic regression models. After multivariate adjustments, we observed a dose-response relationship between increasing total WBC count and arterial stiffness. Participants in the highest tertile of total WBC count showed a significantly elevated baPWV (β = .088; 95% CI: .021, .154; P_trend = .010) and reduced ABI (β = -.027; 95% CI: -.046, -.008; P_trend = .005), as compared with those in the first tertile. The association was similar in different subgroups. In addition, elevated total WBC count was related to a greater risk of macrovascular damage, as indicated by baPWV >1.8 m/s (OR = 1.86; 95% CI: 1.15, 2.99, comparing the extreme tertiles). Our data suggest that elevated total WBC count was related to arterial stiffness among individuals with hypertension.

Role of platelet-derived growth factor c on endothelial dysfunction in cardiovascular diseases

Loss of endothelial function is a common feature to all cardiovascular diseases (CVDs). One of the risk factors associated with the development of CVDs is the hyperglycaemia that occurs in patients with metabolic disorders such as Type 1 and Type 2 diabetes mellitus. Hyperglycaemia causes endothelial dysfunction through increased production of reactive oxygen species (ROS) from different cellular sources leading to oxidative stress. Vascular endothelial growth factor (VEGF) is essential in the stimulation and maintenance of endothelial functional aspects and, although it can mitigate the impact of ROS, VEGF-mediated signalling is partially inhibited in diabetes mellitus. The search for therapeutic strategies that preserve, protect and improve the functions of the endothelium is of great relevance in the investigation of CVDs associated with hyperglycaemia. Platelet-derived growth factor C (PDGF-C) is a peptide with angiogenic properties, independent of VEGF, that stimulates angiogenesis and revascularization of ischemic tissue. In a diabetic mouse model, PDGF-C stimulates mature endothelial cell migration, angiogenesis, endothelial progenitor cell mobilization, and increased neovascularization, and protects blood vessels in a retinal degeneration model activating anti-apoptosis and proliferation signalling pathways in endothelial cells. This review summarizes the information on the damage that high d-glucose causes on endothelial function and the beneficial effects that PDGF-CC could exert in this condition.

Vanadyl sulphate ameliorates biomarkers of endothelial injury and coagulation and thrombosis in a rat model of hyperglycaemia

BACKGROUND

We sought to determine whether the insulin mimicking agent, vanadyl sulphate (Van) can inhibit biomarkers of endothelial injury and coagulation and thrombosis induced by a moderate level of hyperglycaemia.

MATERIAL AND METHODS

Hyperglycaemia was induced in rats by a single injection of streptozotocin (STZ, 50 mg/kg) two weeks after being fed on a high-fat diet (model group). The treatment group started Van (20 mg/kg/day) treatment one-week post STZ injection and continued on Van until being sacrificed at week 10.

RESULTS

Administration of Van to the model group significantly (p < .05) ameliorated dyslipidemia and biomarkers of inflammation (TNF-α, IL-6, and hsCRP) and endothelial injury (E-selectin, P-selectin, sICAM-1, sVCAM-1, and ET-1). Van also significantly inhibited hyperglycaemia-induced blood levels of coagulation (vWF) and thrombosis (PAI-1 and fibrinogen) biomarkers.

CONCLUSIONS

Vanadyl sulphate effectively suppresses hyperglycaemia-induced endothelial injury, coagulation and thrombosis, which is associated with the inhibition of inflammation and dyslipidemia.

Identification of Risk Factors for Coronary Artery Disease in Asymptomatic Patients with Type 2 Diabetes Mellitus

BACKGROUND

Patients with diabetes mellitus (DM) are a high-risk group for coronary artery disease (CAD). In the present study, we investigated predictive factors to identify patients at high risk of CAD among asymptomatic patients with type 2 DM based on coronary computed tomographic angiography (CCTA) findings.

METHODS

A single-center prospective study was performed on 452 consecutive patients with type 2 DM who were provided with a weekly hospital-based diabetes education program between 3 October 2015, and 31 March 2020. A total of 161 consecutive asymptomatic patients (male/female: 111/50, age: 57.3 ± 9.3 years) with type 2 DM without any known CAD underwent CCTA. Based on conventional coronary risk factors and non-invasive examination, i.e., measurement of intima-media thickness, subcutaneous and visceral fat area, a stress electrocardiogram test, and the Agatston score, patients with obstructive CAD, CT-verified high-risk plaques (CT-HRP), and optimal revascularization within 90 days were evaluated.

RESULTS

Current smoking (OR, 4.069; 95% C.I., 1.578-10.493, p = 0.0037) and the Agatston score ≥100 (OR, 18.034; 95% C.I., 6.337-51.324, p = 0.0001) were independent predictive factors for obstructive CAD, while current smoking (OR, 5.013; 95% C.I., 1.683-14.931, p = 0.0038) was an independent predictive factor for CT-HRP. Furthermore, insulin treatment (OR, 5.677; 95% C.I., 1.223-26.349, p = 0.0266) was the only predictive factor that correlated with optimal revascularization within 90 days.

CONCLUSIONS

In asymptomatic patients with type 2 DM, current smoking, an Agatston score ≥100, and insulin treatment were independent predictive factors of patients being at high-risk for CAD. However, non-invasive examinations except for Agatston score were not independent predictors of patients being at high risk of CAD.

Old and Novel Therapeutic Approaches in the Management of Hyperglycemia, an Important Risk Factor for Atherosclerosis

Hyperglycemia is considered one of the main risk factors for atherosclerosis, since high glucose levels trigger multiple pathological processes, such as oxidative stress and hyperproduction of pro-inflammatory mediators, leading to endothelial dysfunction. In this context, recently approved drugs, such as glucagon-like-peptide-1 receptor agonists (GLP-1RAs) and sodium-glucose cotransporter-2 inhibitors (SGLT2i), could be considered a powerful tool for to reduce glucose concentration and cardiovascular risk. Interestingly, many patients with type 2 diabetes mellitus (T2DM) and insulin resistance have been found to be deficient in vitamin D. Recent studies pointed out the unfavorable prognostic values of T2DM and vitamin D deficiency in patients with cardiac dysfunction, either when considered individually or together, which shed light on the role of vitamin D in general health status. New evidence suggests that SGLT2i could adversely affect the production of vitamin D, thereby increasing the risk of fractures, which are common in patients with T2DM. Therefore, given the biological effects of vitamin D as an anti-inflammatory mediator and a regulator of endothelial function and calcium equilibrium, these new findings should be taken into consideration as well. The aim of this review is to gather the latest advancements regarding the use of antidiabetic and antiplatelet drugs coupled with vitamin D supplementation to control glucose levels, therefore reducing the risk of coronary artery disease (CAD).

Elevated Glycated Hemoglobin Levels Are Associated With Poor Outcome in Acute Ischemic Stroke

Objective

Admission hyperglycemia is an established risk factor for functional outcome in patients with acute ischemic stroke. However, the association between glycated hemoglobin (HbA1c) and prognosis in patients with acute anterior circulation ischemic stroke (AACIS) remains controversial. This study aimed to explore whether elevated HbA1c levels are associated with functional outcome in AACIS patients.

Participants and Methods

We enrolled patients with AACIS hospitalized in the First Hospital Affiliated to Soochow University from March 2018 to January 2021. Patients were categorized into three groups based on baseline HbA1c: HbA1c ≤ 6.5%, 6.5% < HbA1c ≤ 8.0%, and HbA1c > 8.0%. Ninety-day modified Rankin Scale scores of 0–1 and 0–2 were defined as excellent and favorable functional outcome, respectively. Early neurological improvement was regarded as a reduction in the National Institutes of Health Stroke Scale (NIHSS) score ≥ 4 points compared with that on admission, or an NIHSS score of 0–1 at discharge. The association between HbA1c and clinical outcome in acute ischemic patients was assessed by logistic regression and adjusted for confounding factors. Subgroup analyses by TOAST classification were also conducted.

Results

The study included 326 patients. The proportion with favorable outcome was significantly lower in the HbA1c > 8.0% group than the HbA1c ≤ 6.5% group (30.4 vs. 55.2%; p < 0.01). Binary logistic regression analysis demonstrated that increasing HbA1c levels (as a continuous variable) were associated with reduced functional independence (adjusted OR = 0.739; 95% CI: 0.605–0.904; p = 0.003). In subgroup analyses, higher HbA1c was also associated with favorable outcome in large-artery atherosclerosis (LAA)-type patients (adjusted OR = 0.776; 95% CI: 0.614–0.981; p = 0.034), but not in LAA group.

Conclusions

HbA1c level was an independent predictor of worse functional outcome in patients with AACIS, particularly in those with LAA. For patients with anterior circulation atherosclerosis, strict adherence to a target HbA1c < 6.5% may be required.

Endothelial mineralocorticoid receptor ablation confers protection towards endothelial dysfunction in experimental diabetes in mice

AIM

With diabetes comes a significant risk of macrovascular and microvascular complications. Circulating aldosterone levels increase in patients with diabetes. Aldosterone can directly affect vascular function via activation of the mineralocorticoid receptor (MR). We hypothesized that aldosterone via endothelial MR impairs endothelial function in a murine model of experimental diabetes.

METHOD

Endothelial cell-specific mineralocorticoid receptor knockout MR^flox/flox ; Tie2-Cre mice (ECMR-KO) and wild-type FVB littermates were subjected to an experimental type-1 diabetic model by low dose streptozotocin injections (55mg/kg/day) for five consecutive days. After 10 weeks of diabetes, second-order mesenteric resistance arteries were perfused ex vivo to evaluate vessel contractility and endothelial function. The effect of ex vivo incubation with aldosterone with and without the antagonist, spironolactone was determined.

RESULTS

Diabetic ECMR-KO and wild-type mice had similar, elevated, plasma aldosterone concentration while only diabetic wild-type mice displayed elevated urine albumin excretion and cardiac and kidney hypertrophy at 10 weeks. There were no differences in contraction (Emax and EC₅₀ ) to thromboxane receptor agonist (U46619) and elevated K⁺ between groups. Wild-type diabetic mice showed impaired acetylcholine (ACh)-dependent relaxation, while diabetic ECMR-KO mice had intact ACh-mediated relaxation. Aldosterone incubation ex vivo impaired ACh mediated relaxation and rendered responses similar to diabetic WT arteries. Direct, ex vivo aldosterone effects were absent in ECMR-KO animals. Ex vivo inhibitory effects of aldosterone on endothelial relaxation in arteries from WT were abolished by spironolactone.

CONCLUSION

These findings show that endothelial cell mineralocorticoid receptor activation accounts for diabetes-induced systemic endothelial dysfunction in experimental diabetes and may explain the cardiovascular protection by MR antagonists in diabetes.

The dual role of the hexosamine biosynthetic pathway in cardiac physiology and pathophysiology

The heart is a highly metabolic organ with extensive energy demands and hence relies on numerous fuel substrates including fatty acids and glucose. However, oxidative stress is a natural by-product of metabolism that, in excess, can contribute towards DNA damage and poly-ADP-ribose polymerase activation. This activation inhibits key glycolytic enzymes, subsequently shunting glycolytic intermediates into non-oxidative glucose pathways such as the hexosamine biosynthetic pathway (HBP). In this review we provide evidence supporting the dual role of the HBP, i.e. playing a unique role in cardiac physiology and pathophysiology where acute upregulation confers cardioprotection while chronic activation contributes to the onset and progression of cardio-metabolic diseases such as diabetes, hypertrophy, ischemic heart disease, and heart failure. Thus although the HBP has emerged as a novel therapeutic target for such conditions, proposed interventions need to be applied in a context- and pathology-specific manner to avoid any potential drawbacks of relatively low cardiac HBP activity.

Thermal dysregulation in patients with multiple sclerosis during SARS-CoV-2 infection. The potential therapeutic role of exercise

Thermoregulation is a homeostatic mechanism that is disrupted in some neurological diseases. Patients with multiple sclerosis (MS) are susceptible to increases in body temperature, especially with more severe neurological signs. This condition can become intolerable when these patients suffer febrile infections such as coronavirus disease-2019 (COVID-19). We review the mechanisms of hyperthermia in patients with MS, and they may encounter when infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Finally, the thermoregulatory role and relevant adaptation to regular physical exercise are summarized.

COVID-19 and Venous Thromboembolism: From Pathological Mechanisms to Clinical Management

Coronavirus disease 2019 (COVID-19), which is becoming a global pandemic, is caused by SARS-CoV-2 infection. In COVID-19, thrombotic events occur frequently, mainly venous thromboembolism (VTE), which is closely related to disease severity and clinical prognosis. Compared with historical controls, the occurrence of VTE in hospitalized and critical COVID-19 patients is incredibly high. However, the pathophysiology of thrombosis and the best strategies for thrombosis prevention in COVID-19 remain unclear, thus needing further exploration. Virchow’s triad elements have been proposed as important risk factors for thrombotic diseases. Therefore, the three factors outlined by Virchow can also be applied to the formation of venous thrombosis in the COVID-19 setting. A thorough understanding of the complex interactions in these processes is important in the search for effective treatments for COVID-19. In this work, we focus on the pathological mechanisms of VTE in COVID-19 from the aspects of endothelial dysfunction, hypercoagulability, abnormal blood flow. We also discuss the treatment of VTE as well as the ongoing clinical trials of heparin anticoagulant therapy. In addition, according to the pathophysiological mechanism of COVID-19-associated thrombosis, we extended the range of antithrombotic drugs including antiplatelet drugs, antifibrinolytic drugs, and anti-inflammatory drugs, hoping to find effective drug therapy and improve the prognosis of VTE in COVID-19 patients.

Overexpression of E3 ubiquitin ligase Cbl attenuates endothelial dysfunction in diabetes mellitus by inhibiting the JAK2/STAT4 signaling and Runx3-mediated H3K4me3

BACKGROUND

Diabetes mellitus (DM), a most common chronic disease, is featured with impaired endothelial function and bioavailability of nitric oxide (NO), while E3 ubiquitin ligase appears to alleviate endothelial dysfunction as a promising option for DM treatment. Herein, we aimed to determine whether E3 ubiquitin ligase casitas B-lineage lymphoma (Cbl) alleviates endothelial dysfunction in DM rats by JAK2/STAT4 pathway.

METHODS

A rat model of DM was developed through intraperitoneal injection of streptozotocin, followed by collection of aortic tissues to determine the expression of Cbl, JAK2, runt-related transcription factor 3 (Runx3) and STAT4. Human umbilical vein endothelial cells (HUVECs) were cultured in high glucose (HG) condition to induce DM as an in vitro model. With gain- and loss-function method, we assessed the aberrantly expressed Cb1 on endothelial dysfunction, NO production and apoptosis of HUVECs.

RESULTS

Cbl was reduced in DM rat tissues and HG-induced HUVECs, where JAK2, Runx3 and STAT4 were elevated. It was found that overexpression of Cbl alleviated endothelial dysfunction by increasing NO production and restoring vasodilation and suppressing apoptosis of HUVECs. Mechanistically, Cb1 enhanced JAK2 ubiquitination and decreased JAK2 and STAT4 expression, where STAT4 improved Runx3 expression by regulating histone H3 lysine 4 trimethylation level. Overexpression of JAK2 and STAT4, or Runx3 increased apoptosis of HUVECs, abrogating the effect of Cb1 on endothelial function.

CONCLUSION

In conclusion, Cbl alleviates endothelial dysfunction by inactivation of the JAK2/STAT4 pathway and inhibition of Runx3 expression in DM. These evidence might underlie novel Cbl-based treatment against DM in the future.

Relevance of N6-methyladenosine regulators for transcriptome: Implications for development and the cardiovascular system

N6-methyladenosine (m6A) is the most abundant and well-studied internal modification of messenger RNAs among the various RNA modifications in eukaryotic cells. Moreover, it is increasingly recognized to regulate non-coding RNAs. The dynamic and reversible nature of m6A is ensured by the precise and coordinated activity of specific proteins able to insert ("write"), bind ("read") or remove ("erase") the m6A modification from coding and non-coding RNA molecules. Mounting evidence suggests a pivotal role for m6A in prenatal and postnatal development and cardiovascular pathophysiology. In the present review we summarise and discuss the major functions played by m6A RNA methylation and its components particularly referring to the cardiovascular system. We present the methods used to study m6A and the most abundantly methylated RNA molecules. Finally, we highlight the possible involvement of the m6A mark in cardiovascular disease as well as the need for further studies to better describe the mechanisms of action and the potential therapeutic role of this RNA modification.

A GLP-1 analog lowers ER stress and enhances protein folding to ameliorate homocysteine-induced endothelial dysfunction

Hyperhomocysteinemia (HHcy) is an independent risk factor for cardiovascular diseases and increases mortality in type 2 diabetic patients. HHcy induces endoplasmic reticulum (ER) stress and oxidative stress to impair endothelial function. The glucagon-like peptide 1 (GLP-1) analog exendin-4 attenuates endothelial ER stress, but the detailed vasoprotective mechanism remains elusive. The present study investigated the beneficial effects of exendin-4 against HHcy-induced endothelial dysfunction. Exendin-4 pretreatment reversed homocysteine-induced impairment of endothelium-dependent relaxations in C57BL/6 mouse aortae ex vivo. Four weeks subcutaneous injection of exendin-4 restored the impaired endothelial function in both aortae and mesenteric arteries isolated from mice with diet-induced HHcy. Exendin-4 treatment lowered superoxide anion accumulation in the mouse aortae both ex vivo and in vivo. Exendin-4 decreased the expression of ER stress markers (e.g., ATF4, spliced XBP1, and phosphorylated eIF2α) in human umbilical vein endothelial cells (HUVECs), and this change was reversed by cotreatment with compound C (CC) (AMPK inhibitor). Exendin-4 induced phosphorylation of AMPK and endothelial nitric oxide synthase in HUVECs and arteries. Exendin-4 increased the expression of endoplasmic reticulum oxidoreductase (ERO1α), an important ER chaperone in endothelial cells, and this effect was mediated by AMPK activation. Experiments using siRNA-mediated knockdown or adenoviral overexpression revealed that ERO1α mediated the inhibitory effects of exendin-4 on ER stress and superoxide anion production, thus ameliorating HHcy-induced endothelial dysfunction. The present results demonstrate that exendin-4 reduces HHcy-induced ER stress and improves endothelial function through AMPK-dependent ERO1α upregulation in endothelial cells and arteries. AMPK activation promotes the protein folding machinery in endothelial cells to suppress ER stress.

The nexus between redox state and intermediary metabolism

Reactive oxygen species (ROS) are not just a by-product of cellular metabolic processes but act as signalling molecules that regulate both physiological and pathophysiological processes. A close connection exists in cells between redox homeostasis and cellular metabolism. In this review, we describe how intracellular redox state and glycolytic intermediary metabolism are closely coupled. On the one hand, ROS signalling can control glycolytic intermediary metabolism by direct regulation of the activity of key metabolic enzymes and indirect regulation via redox-sensitive transcription factors. On the other hand, metabolic adaptation and reprogramming in response to physiological or pathological stimuli regulate intracellular redox balance, through mechanisms such as the generation of reducing equivalents. We also discuss the impact of these intermediary metabolism-redox circuits in physiological and disease settings across different tissues. A better understanding of the mechanisms regulating these intermediary metabolism-redox circuits will be crucial to the development of novel therapeutic strategies.

Peroxidasin promotes diabetic vascular endothelial dysfunction induced by advanced glycation end products via NOX2/HOCl/Akt/eNOS pathway

Reactive oxygen species (ROS) derived from NADPH oxidases (NOX) plays an essential role in advanced glycation end products (AGEs)-induced diabetic vascular endothelial dysfunction. Peroxidasin (PXDN, VPO1) is one member of peroxidases family that catalyzes hydrogen peroxide (H2O2) to hypochlorous acid (HOCl). This present study aimed to elucidate the role of PXDN in promoting vascular endothelial dysfunction induced by AGEs in diabetes mellitus. We found that, compared to non-diabetic (db/m) mice, PXDN expression was notably increased in db/db mice with impaired endothelium-dependent relaxation. Knockdown of PXDN in vivo through tail vein injection of siRNA restored the impaired endothelium-dependent relaxation function of db/db mice which is accompanied with up-regulation of eNOS Ser1177 phosphorylation and NO production. AGEs significantly elevated expression of PXDN and 3-Cl-Tyr, but decreased phosphorylation of Akt and eNOS and NO release in HUVECs. All these effects induced by AGEs were remarkable alleviated by silencing PXDN with small interfering RNAs. In addition, HOCl treatment alone as well as HOCl added with Akt inhibitor MK2206 inhibited phosphorylation of Akt and eNOS, reducing NO production. More importantly,AGEs-induced up-regulation of PXDN and 3-Cl-Tyr with endothelial dysfunction were transformed by NOX2 silencing and H2O2 scavengers. Thus, these results support the conclusion that PXDN promotes AGEs-induced diabetic vascular endothelial dysfunction by attenuating eNOS phosphorylation at Ser1177 via NOX2/HOCl/Akt pathway.

Effects of Sodium-Glucose Co-Transporter 2 Inhibitors on Vascular Cell Function and Arterial Remodeling

Cardiovascular disease is the leading cause of morbidity and mortality in diabetes. Recent clinical studies indicate that sodium-glucose co-transporter 2 (SGLT2) inhibitors improve cardiovascular outcomes in patients with diabetes. The mechanism underlying the beneficial effect of SGLT2 inhibitors is not completely clear but may involve direct actions on vascular cells. SGLT2 inhibitors increase the bioavailability of endothelium-derived nitric oxide and thereby restore endothelium-dependent vasodilation in diabetes. In addition, SGLT2 inhibitors favorably regulate the proliferation, migration, differentiation, survival, and senescence of endothelial cells (ECs). Moreover, they exert potent antioxidant and anti-inflammatory effects in ECs. SGLT2 inhibitors also inhibit the contraction of vascular smooth muscle cells and block the proliferation and migration of these cells. Furthermore, studies demonstrate that SGLT2 inhibitors prevent postangioplasty restenosis, maladaptive remodeling of the vasculature in pulmonary arterial hypertension, the formation of abdominal aortic aneurysms, and the acceleration of arterial stiffness in diabetes. However, the role of SGLT2 in mediating the vascular actions of these drugs remains to be established as important off-target effects of SGLT2 inhibitors have been identified. Future studies distinguishing drug- versus class-specific effects may optimize the selection of specific SGLT2 inhibitors in patients with distinct cardiovascular pathologies.