The endothelial cell in health and disease: its function, dysfunction, measurement and therapy

Co-therapy with S1P and heparan sulfate derivatives to restore endothelial glycocalyx and combat pro-atherosclerotic endothelial dysfunction

AIMS

Endothelial cell (EC) glycocalyx (GCX) shedding from disturbed blood flow and chemical factors leads to low-density lipoprotein infiltration, reduced nitric oxide synthesis, vascular dysfunction and atherosclerosis. This study evaluates a therapy combining sphingosine-1-phosphate (S1P) and heparin (heparan sulfate derivative). We hypothesized that heparin/S1P co-treatment repairs mechanically damaged EC GCX in disturbed flow (DF) regions and restores anti-atherosclerotic mechanotransduction to treat cardiovascular disease.

MATERIALS AND METHODS

We used a parallel-plate flow chamber to simulate flow conditions in vitro and a partial carotid ligation mouse model to mimic DF in vivo. Heparin and albumin-bound S1P were administered to assess their reparative effects on the endothelial GCX. Fluorescent staining, confocal microscopy, and ultrasound evaluated endothelial cell function and endothelial-dependent vascular function. Barrier functionality was assessed via macrophage uptake. Heparin/S1P mechanism-of-action insights were gained through fluid dynamics simulations and staining of GCX synthesis enzyme and S1P receptor. Statistical analyses validated the results.

KEY FINDINGS

The in vitro data showed that heparin/S1P therapy improves DF-conditioned ECs by restoring GCX and elevating vasodilator eNOS (endothelial-type nitric oxide synthase) expression. In vivo studies confirmed GCX degradation, vessel inflammation, hyperpermeability, and wall thickening in the mouse model's partially ligated left carotid artery. Heparin/S1P treatment restored GCX thickness and coverage, reduced inflammation and hyperpermeability, and inhibited vessel wall thickening.

SIGNIFICANCE

This work introduces a new approach to regenerating the EC GCX and restoring its function in ECs under DF conditions, offering a groundbreaking solution for preventing cardiovascular diseases like atherosclerosis.

Revisiting experimental models of erectile dysfunction and their value in drug discovery and development

INTRODUCTION

Erectile dysfunction (ED) is a common condition that often signals underlying endothelial dysfunction, although the underlying causative factor(s) are likely complex and multifactorial. Various animal models have been developed to provide a research platform to study ED and served as an important basis for the discovery and subsequent development of novel therapeutic drugs for ED.

AREAS COVERED

The review article provides an overview of various animal models in ED research with an emphasis on important drug target discovery relating to each specific experimental model. The authors highlight translation from basic science research to major preclinical and clinical studies in this evolving field of ED research.

EXPERT OPINION

Animal models simulate the pathological features of various types of ED and clarify their molecular mechanisms. These mechanisms aid in discovering drug targets, while established ED models also provide a basis for validating drug efficacy, safety, and specific action mechanisms. The development of techniques in detection methods, cellular experimental, and omics has a profound impact on disease prediction, model evaluation, and optimization of therapeutic modalities. On this basis, many drug therapies targeting these ED-related mechanisms, especially in the nitric oxide/cyclic guanosine monophosphate pathways have been applied in preclinical studies. However, focusing on drug development for those types of ED where phosphodiesterase 5 inhibitor therapy is limited may be more valuable.

Development of Electrospinning Setup for Vascular Tissue-Engineering Application with Thick-Hierarchical Fiber Alignment

BACKGROUND

Tissue engineering holds promise for vascular repair and regeneration by mimicking the extracellular matrix of blood vessels. However, achieving a functional and thick vascular wall with aligned fiber architecture by electrospinning remains a significant challenge.

METHODS

A novel electrospinning setup was developed that utilizes an auxiliary electrode and a spring. The impact of process parameters on fiber size and morphology was investigated. The structure and functions of the scaffolds were evaluated through material characterization and assessments of cellular biocompatibility.

RESULTS

The new setup enabled controlled deposition of fibers in different designed orientations. The fabricated small-diameter vascular scaffolds consisted of an inner layer of longitudinally oriented fibers and an outer layer of circumferentially oriented fibers (L + C vascular scaffold). Key parameters, including rotational speed, the utilization of the auxiliary electrode, and top-to-collector distance (TCD) significantly influenced fiber orientation. Additionally, voltage, TCD, feed rate, needle size, auxiliary electrode and collector-auxiliary electrode distance affected fiber diameter and distribution. Mechanical advantages and improved surface wettability of L + C vascular scaffold were confirmed through tensile testing and water contact angle. Cellular experiments indicated that L + C vascular scaffold facilitated cell adhesion and proliferation, with human umbilical vein endothelial cells and smooth muscle cells attaching and elongating along the fiber direction of the inner and outer layer, respectively.

CONCLUSION

This study demonstrated the feasibility of fabricating fiber-aligned, thick-walled vascular scaffolds using a modified electrospinning setup. The findings provided insights into how the auxiliary electrode, specific collector influenced fiber deposition, potentially advancing biomimetic vascular scaffold engineering.

Co-Therapy with S1P and Heparan Sulfate Derivatives to Restore Endothelial Glycocalyx and Combat Pro-Atherosclerotic Endothelial Dysfunction

Endothelial cell (EC) glycocalyx (GCX) shedding due to disturbed blood flow and chemical factors leads to low-density lipoprotein infiltration and reduced nitric oxide synthesis, causing vascular dysfunction and atherosclerosis. This study evaluates a novel therapy combining sphingosine-1-phosphate (S1P) and heparin (heparan sulfate derivative). We hypothesized that heparin/S1P would repair mechanically damaged EC GCX in disturbed flow (DF) regions and restore anti-atherosclerotic mechanotransduction function, addressing cardiovascular disease. We used a parallel-plate flow chamber to simulate flow conditions in vitro and a partial carotid ligation mouse model to mimic DF in vivo. Heparin and albumin-bound S1P were administered to assess their reparative effects on the endothelial GCX. Immunocytochemistry, fluorescent staining, confocal microscopy, cellular alignment studies, and ultrasound were performed to evaluate EC function and endothelial-dependent vascular function. Barrier functionality was assessed via macrophage uptake. Heparin/S1P mechanism-of-action insights were gained through fluid dynamics simulations and staining of GCX synthesis enzyme as well as S1P receptor. Statistical analyses validated results. In vitro data showed that heparin/S1P therapy improves the function of DF-conditioned ECs by restoring EC GCX and promoting EC alignment and elevated vasodilator eNOS (endothelial-type nitric oxide synthase) expression. The in vivo studies confirmed GCX degradation, increased vessel inflammation and hyperpermeability, and vessel wall thickening in the partially ligated left carotid artery. Heparin/S1P treatment restored GCX in the left carotid artery, enhancing GCX thickness and coverage of the blood vessel wall. This work advances a new approach to regenerating the EC GCX and restoring its function in ECs under DF conditions.

M. AQM, Wang X, Tuo Y, Liang X, Xie H, He R, Li G. Nesfatin-1 regulates the phenotype transition of cavernous smooth muscle cells by activating PI3K/AKT/mTOR signaling pathway to improve diabetic erectile dysfunction

OBJECTIVE

This study aims to explore the impact of Nesfatin-1 on type 2 diabetic erectile dysfunction (T2DMED) and its underlying mechanism in regulating the phenotypic switching of corpus cavernosum smooth muscle cells (CCSMCs).

METHODS

Twenty-four 4-week-old male C57 wild-type mice were randomly assigned to the control group, model group, and Nesfatin-1 treatment group. Monitoring included body weight, blood glucose levels, and penile cavernous pressure (ICP). Histochemistry and Western blot analyses were conducted to assess the expressions of α-SMA, OPN, and factors related to the PI3K/AKT/mTOR signaling pathway. CCSMCs were categorized into the control group, high glucose and high oleic acid group (GO group), Nesfatin-1 treatment group (GO+N group), sildenafil positive control group (GO+S group), and PI3K inhibitor group (GO+N+E group). Changes in phenotypic markers, cell morphology, and the PI3K/AKT/mTOR signaling pathway were observed in each group.

RESULTS

(1) Nesfatin-1 significantly ameliorated the body size, body weight, blood glucose, glucose tolerance, and insulin resistance in T2DMED mice. (2) Following Nesfatin-1 treatment, the ICP/MSBP ratio and the peak of the ICP curve demonstrated a significant increase. (3) Nesfatin-1 significantly enhanced smooth muscle and reduced collagen fibers in the corpus cavernosum. (4) Nesfatin-1 notably increased α-SMA expression and decreased OPN expression in CCSMCs. (5) Nesfatin-1 elevated PI3K, p-AKT/AKT, and p-mTOR/mTOR levels in penile cavernous tissue.

CONCLUSIONS

Nesfatin-1 not only effectively improves body weight and blood glucose levels in diabetic mice but also enhances erectile function and regulates the phenotypic switching of corpus cavernosum smooth muscle. The potential mechanism involves Nesfatin-1 activating the PI3K/AKT/mTOR signaling pathway to induce the conversion of CCSMCs to a contractile phenotype.

The Role of Endothelial Cell Mitophagy in Age-Related Cardiovascular Diseases

Aging is a major risk factor for cardiovascular diseases (CVD), and mitochondrial autophagy impairment is considered a significant physiological change associated with aging. Endothelial cells play a crucial role in maintaining vascular homeostasis and function, participating in various physiological processes such as regulating vascular tone, coagulation, angiogenesis, and inflammatory responses. As aging progresses, mitochondrial autophagy impairment in endothelial cells worsens, leading to the development of numerous cardiovascular diseases. Therefore, regulating mitochondrial autophagy in endothelial cells is vital for preventing and treating age-related cardiovascular diseases. However, there is currently a lack of systematic reviews in this area. To address this gap, we have written this review to provide new research and therapeutic strategies for managing aging and age-related cardiovascular diseases.

Innovative Treatments to Counteract Endothelial Dysfunction in Chronic Kidney Disease Patients

In chronic kidney disease (CKD) patients, several risk factors contribute to the development of endothelial dysfunction (ED), which can be described as an alteration in the cell structure or in the function of the endothelium. Among the well-known CKD-related risk factors capable of altering the production of endothelium-derived relaxing factors, we include asymmetric dimethylarginine increase, reduced dimethylarginine dimethylamine hydrolase enzyme activity, low-grade chronic systemic inflammation, hyperhomocysteinemia, oxidative stress, insulin resistance, alteration of calcium phosphorus metabolism, and early aging. In this review, we also examined the most important techniques useful for studying ED in humans, which are divided into indirect and direct methods. The direct study of coronary endothelial function is considered the gold standard technique to evaluate if ED is present. In addition to the discussion of the main pharmacological treatments useful to counteract ED in CKD patients (namely sodium-glucose cotransporter 2 inhibitors and mineralocorticoid receptor antagonist), we elucidate innovative non-pharmacological treatments that are successful in accompanying the pharmacological ones. Among them, the most important are the consumption of extra virgin olive oil with high intake of minor polar compounds, adherence to a plant-dominant, low-protein diet (LPD), an adaptive physical activity program and, finally, ketoanalogue administration in combination with the LPD or the very low-protein diet.

Design and Synthesis of P(AAm-co-NaAMPS)-Alginate-Xanthan Hydrogels and the Study of Their Mechanical and Rheological Properties in Artificial Vascular Graft Applications

Cardiovascular diseases (CVDs) are the number one cause of mortality among non-communicable diseases worldwide. Expanded polytetrafluoroethylene (ePTFE) is a widely used material for making artificial vascular grafts to treat CVDs; however, its application in small-diameter vascular grafts is limited by the issues of thrombosis formation and intimal hyperplasia. This paper presents a novel approach that integrates a hydrogel layer on the lumen of ePTFE vascular grafts through mechanical interlocking to efficiently facilitate endothelialization and alleviate thrombosis and restenosis problems. This study investigated how various gel synthesis variables, including N,N'-Methylenebisacrylamide (MBAA), sodium alginate, and calcium sulfate (CaSO4), influence the mechanical and rheological properties of P(AAm-co-NaAMPS)-alginate-xanthan hydrogels intended for vascular graft applications. The findings obtained can provide valuable guidance for crafting hydrogels suitable for artificial vascular graft fabrication. The increased sodium alginate content leads to increased equilibrium swelling ratios, greater viscosity in hydrogel precursor solutions, and reduced transparency. Adding more CaSO4 decreases the swelling ratio of a hydrogel system, which offsets the increased swelling ratio caused by alginate. Increased MBAA in the hydrogel system enhances both the shear modulus and Young's modulus while reducing the transparency of the hydrogel system and the pore size of freeze-dried samples. Overall, Hydrogel (6A12M) with 2.58 mg/mL CaSO4 was the optimal candidate for ePTFE-hydrogel vascular graft applications due to its smallest pore size, highest shear storage modulus and Young's modulus, smallest swelling ratio, and a desirable precursor solution viscosity that facilitates fabrication.

The Role of NRF2 in Cerebrovascular Protection: Implications for Vascular Cognitive Impairment and Dementia (VCID)

Vascular cognitive impairment and dementia (VCID) represents a broad spectrum of cognitive decline secondary to cerebral vascular aging and injury. It is the second most common type of dementia, and the prevalence continues to increase. Nuclear factor erythroid 2-related factor 2 (NRF2) is enriched in the cerebral vasculature and has diverse roles in metabolic balance, mitochondrial stabilization, redox balance, and anti-inflammation. In this review, we first briefly introduce cerebrovascular aging in VCID and the NRF2 pathway. We then extensively discuss the effects of NRF2 activation in cerebrovascular components such as endothelial cells, vascular smooth muscle cells, pericytes, and perivascular macrophages. Finally, we summarize the clinical potential of NRF2 activators in VCID.

Origins and functional differences of blood endothelial cells

The interests in blood endothelial cells arise from their therapeutic potential in vascular repair and regeneration. Our understanding of blood endothelial cells that exist in the circulation has been evolving significantly from the original concept of endothelial progenitor cells. Many studies have uncovered heterogeneities of blood endothelial subtypes where some cells express both endothelial and hematopoietic antigens, and others possess either mature or immature endothelial markers. Due to the lack of definitive cell marker identities, there have been momentums in the field to adopt a technical-oriented labeling system based on the cells' involvement in postnatal neovascularization and cell culture derivatives. Our review streamlines nomenclatures for blood endothelial subtypes and standardizes understanding of their functional differences. Broadly, we will discuss about myeloid angiogenic cells (MACs), endothelial colony-forming cells (ECFCs), blood outgrowth endothelial cells (BOECs) and circulating endothelial cells (CECs). The strategic location of blood endothelial cells confers them essential roles in supporting physiological processes. MACs exert angiogenic effects through paracrine mechanisms, while ECFCs are recruited to sites of vascular injury to participate directly in new vessel formation. BOECs are an in vitro derivative of ECFCs. CECs are shed into the bloodstream from damaged vessels, hence reflective of endothelial dysfunction. With clarity on the functional attributes of blood endothelial subtypes, we present recent advances in their applications in disease modelling, along with serving as biomarkers of vascular tissue homeostasis.

Anti-thrombotic poly(AAm-co-NaAMPS)-xanthan hydrogel-expanded polytetrafluoroethylene (ePTFE) vascular grafts with enhanced endothelialization and hemocompatibility properties

Cardiovascular diseases (CVDs) are the leading cause of death among all non-communicable diseases globally. Although expanded polytetrafluoroethylene (ePTFE) has been widely used for larger-diameter vascular graft transplantation, the persistent thrombus formation and intimal hyperplasia of small-diameter vascular grafts (SDVGs) made of ePTFE to treat severe CVDs remain the biggest challenges due to lack of biocompatibility and endothelium. In this study, bi-layered poly(acrylamide-co-2-Acrylamido-2-methyl-1-propanesulfonic acid sodium)-xanthan hydrogel-ePTFE (poly(AAm-co-NaAMPS)-xanthan hydrogel-ePTFE) vascular grafts capable of promoting endothelialization and prohibiting thrombosis were synthesized and fabricated. While the external ePTFE layer of the vascular grafts provided the mechanical stability, the inner hydrogel layer offered much-needed cytocompatibility, hemocompatibility, and endothelialization functions. The interface morphology between the inner hydrogel layer and the outer ePTFE layer was observed by scanning electron microscope (SEM), which revealed that the hydrogel was well attached to the porous ePTFE through mechanical interlocking. Among all the hydrogel compositions tested with cell culture using human umbilical vein endothelial cells (HUVECs), the hydrogel with the molar ratio of 40:60 (NaAMPS/AAm) composition (i.e., Hydrogel 40:60) exhibited the best endothelialization function, as it produced the largest endothelialization area that was three times more than of that of plain ePTFE on day 14, maintained the highest average cell viability, and had the best cell morphology. Hydrogel 40:60 also showed excellent hemocompatibility, prolonged activated partial thromboplastin time (aPTT), and good mechanical properties. Overall, bi-layered poly(AAm-co-NaAMPS)-xanthan hydrogel-ePTFE vascular grafts with the Hydrogel 40:60 composition could potentially solve the critical challenge of thrombus formation in vascular graft transplantation applications.

Progress on Physical Field-Regulated Micro/Nanomotors for Cardiovascular and Cerebrovascular Disease Treatment

Cardiovascular and cerebrovascular diseases (CCVDs) are two major vasculature-related diseases that seriously affect public health worldwide, which can cause serious death and disability. Lack of targeting effect of the traditional CCVD treatment drugs may damage other tissues and organs, thus more specific methods are needed to solve this dilemma. Micro/nanomotors are new materials that can convert external energy into driving force for autonomous movement, which can not only enhance the penetration depth and retention rates, but also increase the contact areas with the lesion sites (such as thrombus and inflammation sites of blood vessels). Physical field-regulated micro/nanomotors using the physical energy sources with deep tissue penetration and controllable performance, such as magnetic field, light, and ultrasound, etc. are considered as the emerging patient-friendly and effective therapeutic tools to overcome the limitations of conventional CCVD treatments. Recent efforts have suggested that physical field-regulated micro/nanomotors on CCVD treatments could simultaneously provide efficient therapeutic effect and intelligent control. In this review, various physical field-driven micro/nanomotors are mainly introduced and their latest advances for CCVDs are highlighted. Last, the remaining challenges and future perspectives regarding the physical field-regulated micro/nanomotors for CCVD treatments are discussed and outlined.

Vasodilating Effects of Antispasmodic Agents and Their Cytotoxicity in Vascular Smooth Muscle Cells and Endothelial Cells-Potential Application in Microsurgery

This study aimed to elucidate the vasodilatory effects and cytotoxicity of various vasodilators used as antispasmodic agents during microsurgical anastomosis. Rat smooth muscle cells (RSMCs) and human coronary artery endothelial cells (HCAECs) were used to investigate the physiological concentrations and cytotoxicity of various vasodilators (lidocaine, papaverine, nitroglycerin, phentolamine, and orciprenaline). Using a wire myograph system, we determined the vasodilatory effects of each drug in rat abdominal aortic sections at the concentration resulting in maximal vasodilation as well as at the surrounding concentrations 10 min after administration. Maximal vasodilation effect 10 min after administration was achieved at the following concentrations: lidocaine, 35 mM; papaverine, 0.18 mM; nitroglycerin, 0.022 mM; phentolamine, 0.11 mM; olprinone, 0.004 mM. The IC₅₀ for lidocaine, papaverine, and nitroglycerin was measured in rat abdominal aortic sections, as well as in RSMCs after 30 min and in HCAECs after 10 min. Phentolamine and olprinone showed no cytotoxicity towards RSMCs or HCAECs. The concentrations of the various drugs required to achieve vasodilation were lower than the reported clinical concentrations. Lidocaine, papaverine, and nitroglycerin showed cytotoxicity, even at lower concentrations than those reported clinically. Phentolamine and olprinone show antispasmodic effects without cytotoxicity, making them useful candidates for local administration as antispasmodics.

Release of 6-nitrodopamine from human popliteal artery and vein

6-Nitrodopamine (6-ND) is a novel catecholamine that is released from human umbilical cord vessels, and it causes vascular relaxation by acting as a dopamine D₂-receptor antagonist. Here it was investigated whether human peripheral vessels obtained from patients who have undergone surgery for leg amputation release 6-ND, and its action in these tissues. Popliteal artery and vein strips present basal release of 6-ND, as measure by liquid chromatography coupled to tandem mass spectrometry. The release was significantly reduced when the tissues were pre-treated with the nitric oxide synthase inhibitor L-NAME (100 μM), or when the endothelium was mechanically removed. In U-46619 (3 nM) pre-contracted rings, 6-ND induced concentration-dependent relaxations (pEC50 8.18 ± 0.05 and 8.40 ± 0.08, in artery and vein rings, respectively). The concentration-dependent relaxations induced by 6-ND were unaffected in tissues pre-treated with L-NAME, but significantly reduced in tissues where the endothelium has been mechanically removed. In U-46619 (3 nM) pre-contracted rings, the selective dopamine D₂ receptor antagonist L-741,626 also caused concentration-dependent relaxations (pEC₅₀ 8.92 ± 0.22 and 8.79 ± 0.19, in artery and vein rings, respectively). The concentration-dependent relaxations induced by L-741,626 were unaffected in tissues pre-treated with L-NAME, but significantly reduced in tissues where the endothelium has been mechanically removed. This is the first demonstration that 6-nitrodopamine is released from human peripheral artery and vein rings. The results also indicate that endothelium-derived dopamine is a major contractile agent in the popliteal artery and vein, and that selective dopamine D₂-receptor antagonists such as 6-ND, may have therapeutic potential in the treatment of human peripheral vascular diseases.

Inflammasomes: a rising star on the horizon of COVID-19 pathophysiology

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a contagious respiratory virus that is the cause of the coronavirus disease 2019 (COVID-19) pandemic which has posed a serious threat to public health. COVID-19 is characterized by a wide spectrum of clinical manifestations, ranging from asymptomatic infection to mild cold-like symptoms, severe pneumonia or even death. Inflammasomes are supramolecular signaling platforms that assemble in response to danger or microbial signals. Upon activation, inflammasomes mediate innate immune defense by favoring the release of proinflammatory cytokines and triggering pyroptotic cell death. Nevertheless, abnormalities in inflammasome functioning can result in a variety of human diseases such as autoimmune disorders and cancer. A growing body of evidence has showed that SARS-CoV-2 infection can induce inflammasome assembly. Dysregulated inflammasome activation and consequent cytokine burst have been associated with COVID-19 severity, alluding to the implication of inflammasomes in COVID-19 pathophysiology. Accordingly, an improved understanding of inflammasome-mediated inflammatory cascades in COVID-19 is essential to uncover the immunological mechanisms of COVID-19 pathology and identify effective therapeutic approaches for this devastating disease. In this review, we summarize the most recent findings on the interplay between SARS-CoV-2 and inflammasomes and the contribution of activated inflammasomes to COVID-19 progression. We dissect the mechanisms involving the inflammasome machinery in COVID-19 immunopathogenesis. In addition, we provide an overview of inflammasome-targeted therapies or antagonists that have potential clinical utility in COVID-19 treatment.

The activation of histone deacetylases 4 prevented endothelial dysfunction: A crucial mechanism of HuangqiGuizhiWuwu Decoction in improving microcirculation dysfunction in diabetes

ETHNOPHARMACOLOGICAL RELEVANCE

The regulation of epigenetic factors is considered a crucial target for solving complex chronic diseases such as cardio-cerebrovascular diseases. HuangqiGuizhiWuwu Decoction (HGWWD), a classic Chinese prescription, is mainly used to treat various vascular diseases. Although our previous studies reported that HGWWD could effectively prevent vascular dysfunction in diabetic rodent models, the precise mechanism is still elusive.

AIM OF THE STUDY

In this study, we investigated the epigenetic mechanisms of modulating the damage of vascular endothelial cells in diabetes by HGWWD.

METHODS

We first analyzed common active components of HGWWD by using HPLC-Q-TOF-MS/MS analysis, and predicted the isoforms of histone deacetylase (HDAC) that can potentially combine the above active components by systems pharmacology. Next, we screened the involvement of specific HDAC isoforms in the protective effect of HGWWD on vascular injury by using pharmacological blockade combined with the evaluation of vascular function in vivo and in vitro.

RESULTS

Firstly, HDAC1, HDAC2, HDAC3, HDAC4, HDAC6, HDAC7, SIRT2, and SIRT3 have been implicated with the possibility of binding to the thirty-one common active components in HGWWD. Furthermore, the protective effect of HGWWD is reversed by both TSA (HDAC inhibitor) and MC1568 (class II HDAC inhibitor) on vascular impairment accompanied by reduced aortic HDAC activity in STZ mice. Finally, inhibition of HDAC4 blocked the protective effect of HGWWD on microvascular and endothelial dysfunction in diabetic mice.

CONCLUSIONS

These results prove the key role of HDAC4 in diabetes-induced microvascular dysfunction and underlying epigenetic mechanisms for the protective effect of HGWWD in diabetes.

Development of an In Vitro Blood Vessel Model Using Autologous Endothelial Cells Generated from Footprint-Free hiPSCs to Analyze Interactions of the Endothelium with Blood Cell Components and Vascular Implants

Cardiovascular diseases are the leading cause of death globally. Vascular implants, such as stents, are required to treat arterial stenosis or dilatation. The development of innovative stent materials and coatings, as well as novel preclinical testing strategies, is needed to improve the bio- and hemocompatibility of current stents. In this study, a blood vessel-like polydimethylsiloxane (PDMS) model was established to analyze the interaction of an endothelium with vascular implants, as well as blood-derived cells, in vitro. Using footprint-free human induced pluripotent stem cells (hiPSCs) and subsequent differentiation, functional endothelial cells (ECs) expressing specific markers were generated and used to endothelialize an artificial PDMS lumen. The established model was used to demonstrate the interaction of the created endothelium with blood-derived immune cells, which also allowed for real-time imaging. In addition, a stent was inserted into the endothelialized lumen to analyze the surface endothelialization of stents. In the future, this blood vessel-like model could serve as an in vitro platform to test the influence of vascular implants and coatings on endothelialization and to analyze the interaction of the endothelium with blood cell components.

Role of angiogenic transdifferentiation in vascular recovery

Tissue repair requires the orchestration of multiple processes involving a multiplicity of cellular effectors, signaling pathways, and cell-cell communication. The regeneration of the vasculature is a critical process for tissue repair and involves angiogenesis, adult vasculogenesis, and often arteriogenesis, which processes enable recovery of perfusion to deliver oxygen and nutrients to the repair or rebuild of the tissue. Endothelial cells play a major role in angiogenesis, whereas circulating angiogenic cells (primarily of hematopoietic origin) participate in adult vasculogenesis, and monocytes/macrophages have a defining role in the vascular remodeling that is necessary for arteriogenesis. Tissue fibroblasts participate in tissue repair by proliferating and generating the extracellular matrix as the structural scaffold for tissue regeneration. Heretofore, fibroblasts were not generally believed to be involved in vascular regeneration. However, we provide new data indicating that fibroblasts may undergo angiogenic transdifferentiation, to directly expand the microvasculature. Transdifferentiation of fibroblasts to endothelial cells is initiated by inflammatory signaling which increases DNA accessibility and cellular plasticity. In the environment of under-perfused tissue, the activated fibroblasts with increased DNA accessibility can now respond to angiogenic cytokines, which provide the transcriptional direction to induce fibroblasts to become endothelial cells. Periphery artery disease (PAD) involves the dysregulation of vascular repair and inflammation. Understanding the relationship between inflammation, transdifferentiation, and vascular regeneration may lead to a new therapeutic approach to PAD.

Diosmin and its glycocalyx restorative and anti-inflammatory effects on injured blood vessels

The endothelium, a crucial homeostatic organ, regulates vascular permeability and tone. Under physiological conditions, endothelial stimulation induces vasodilator endothelial nitric oxide (eNO) release and prevents adhesion molecule accessibility and leukocyte adhesion and migration into vessel walls. Endothelium dysfunction is a principal event in cardiovascular disorders, including atherosclerosis. Minimal attention is given to an important endothelial cell structure, the endothelial glycocalyx (GCX), a negatively charged heterogeneous polysaccharide that serves as a protective covering for endothelial cells and enables endothelial cells to transduce mechanical stimuli into various biological and chemical activities. Endothelial GCX shedding thus plays a role in endothelial dysfunction, for example by increasing vascular permeability and decreasing vessel tone. Consequently, there is increasing interest in developing therapies that focus on GCX repair to limit downstream endothelium dysfunction and prevent further downstream cardiovascular events. Here, we present diosmin (3',5,7-trihydroxy-4'-methoxyflavone-7-rhamnoglucoside), a flavone glycoside of diosmetin, which downregulates adhesive molecule expression, decreases inflammation and capillary permeability, and upregulates eNO expression. Due to these pleiotropic effects of diosmin on the vasculature, a possible unidentified mechanism of action is through GCX restoration. We hypothesize that diosmin positively affects GCX integrity along with GCX-related endothelial functions. Our hypothesis was tested in a partial ligation left carotid artery (LCA) mouse model, where the right carotid artery was the control for each mouse. Diosmin (50 mg/kg) was administered daily for 7 days, 72 h after ligation. Within the ligated mice LCAs, diosmin treatment elevated the activated eNO synthase level, inhibited inflammatory cell uptake, decreased vessel wall thickness, increased vessel diameter, and increased GCX coverage of the vessel wall. ELISA showed a decrease in hyaluronan concentration in plasma samples of diosmin-treated mice, signifying reduced GCX shedding. In summary, diosmin supported endothelial GCX integrity, to which we attribute diosmin's preservation of endothelial function as indicated by attenuated expression of inflammatory factors and restored vascular tone.

Managing life-threatening 5-fluorouracil cardiotoxicity

5-Fluorouracil (5-FU), a known cardiotoxin, is the backbone for the treatment of colorectal cancer. It is associated with arrhythmias, myocardial infarction and sudden cardiac death. Most commonly, it is associated with coronary vasospasm secondary to direct toxic effects on vascular endothelium.A woman with metastatic colon cancer, originally treated with a 5-FU infusion as part of the FOLFIRI (Folinic acid, 5-Fluorouracil, Irinotecan) regimen, was unable to tolerate the chemotherapy due to chest pain. She was transitioned from infusional 5-FU to inferior 1-hour bolus 5-FU, in an attempt to minimise cardiotoxicity, but had disease progression. A multidisciplinary decision was made to again trial 5-FU infusion and pretreat with diltiazem. She tolerated chemotherapy without adverse events. A multidisciplinary discussion is recommended for co-management of reversible 5-FU-associated cardiotoxicity. After coronary artery disease (CAD) risk stratification and treatment, empiric treatment with calcium channel blockers and/or nitrates may allow patients with suspected coronary vasospasm, from 5-FU, to continue this vital chemotherapy.

Pendimethalin induces apoptotic cell death through activating ER stress-mediated mitochondrial dysfunction in human umbilical vein endothelial cells

Pendimethalin is globally registered for control of a wide range of weeds in agriculture and home landscaping. Human exposure to pendimethalin can occur by the oral route through food and other sources. Endothelial function is vital to numerous biological processes, and endothelial dysfunction and poor vascular health is associated with increased atherosclerotic events; however, no study has yet investigated the potential effect of pendimethalin on endothelial function and vasculature formation. The objective of the current study is to investigate if pendimethalin may affect the viability and function of vascular endothelial cells. We observed that pendimethalin significantly repressed viability of human endothelial cells, inducing G1 cell cycle arrest and apoptotic/necrotic cell death. Pendimethalin treatment also activated ER stress and autophagy, leading to loss of mitochondrial membrane potential. In addition, pendimethalin impaired the tube forming and migratory abilities of endothelial cells. This study provides previously unrecognized adverse effects of pendimethalin in vascular endothelial cells, mediated by ER stress-induced mitochondrial dysfunction.

A fabric-based multifunctional sensor for the early detection of skin decubitus ulcers

Monitoring biosignals at the skin interface is necessary to suppress the potential for decubitus ulcers in immobile patients confined to bed. We develop conformally contacted, disposable, and breathable fabric-based electronic devices to detect skin impedance, applied pressure, and temperature, simultaneously. Based on the experimental evaluation of the multifunctional sensors, a combination of robust AgNW electrodes, soft ionogel capacitive pressure sensor, and resistive temperature sensor on fabric provides alarmed the initiation of early-stage decubitus ulcers without signal distortion under the external stimulus. For clinical verification, an animal model is established with a pair of magnets to mimic a human decubitus ulcers model in murine in vivo. The evidence of pressure-induced ischemic injury is confirmed with the naked eye and histological and molecular biomarker analyses. Our multifunctional integrated sensor detects the critical time for early-stage decubitus ulcer, establishing a robust correlation with the biophysical parameters of skin ischemia and integrity, including temperature and impedance.

Preparation and Evaluation of Animal Models of Cardiotoxicity in Antineoplastic Therapy

The continuous development of antineoplastic therapy has significantly reduced the mortality of patients with malignant tumors, but its induced cardiotoxicity has become the primary cause of long-term death in patients with malignant tumors. However, the pathogenesis of cardiotoxicity of antineoplastic therapy is currently unknown, and practical means of prevention and treatment are lacking in clinical practice. Therefore, how to effectively prevent and treat cardiotoxicity while treating tumors is a major challenge. Animal models are important tools for studying cardiotoxicity in antitumor therapy and are of great importance in elucidating pathophysiological mechanisms and developing and evaluating modality drugs. In this paper, we summarize the existing animal models in antitumor therapeutic cardiotoxicity studies and evaluate the models by observing the macroscopic signs, echocardiography, and pathological morphology of the animals, aiming to provide a reference for subsequent experimental development and clinical application.

Circulatory Exosomes from COVID-19 Patients Trigger NLRP3 Inflammasome in Endothelial Cells

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection induces inflammatory response, cytokine storm, venous thromboembolism, coagulopathy, and multiple organ damage. Resting endothelial cells prevent coagulation, control blood flow, and inhibit inflammation. However, it remains unknown how SARS-CoV-2 induces strong molecular signals in distant cells for immunopathogenesis. In this study, we examined the consequence of human endothelial cells, microvascular endothelial cells (HMEC-1), and liver endothelial cells (TMNK-1) to exosomes isolated from plasma of mild or severe COVID-19 patients. We observed a significant induction of NLRP3, caspase-1, and interleukin-1β (IL-1β) mRNA expression in endothelial cells following exposure to exosomes from severe COVID-19 patients compared with that from patients with mild disease or healthy donors. Activation of caspase-1 was noted in the endothelial cell culture medium following exposure to the COVID-19 exosomes. Furthermore, COVID-19 exosomes significantly induced mature IL-1β secretion in both HMEC-1 and TMNK-1 endothelial cell culture medium. Thus, our results demonstrated for the first time that exosomes from COVID-19 plasma trigger NLRP3 inflammasome in endothelial cells of distant organs resulting in IL-1β secretion and inflammatory response. IMPORTANCE Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is a global health problem. Although the vaccine controls infection, understanding the molecular mechanism of pathogenesis will help in developing future therapies. Furthermore, several investigators predicted the involvement of endothelial cell-related inflammation in SARS-CoV-2 infection and using extracellular vesicles as a cargo to carry a drug or vaccine for combating SARS-CoV-2 infection. However, the mechanism by which endothelial cells are inflamed remains unknown. Our present study highlights that exosomes from severe COVID-19 patients can enhance inflammasome activity in distant endothelial cells for augmentation of immunopathogenesis and opens an avenue for developing therapies.

An ApoA-I Mimic Peptide of 4F Promotes SDF-1α Expression in Endothelial Cells Through PI3K/Akt/ERK/HIF-1α Signaling Pathway

Atherosclerosis (AS) seriously impairs the health of human beings and is manifested initially as endothelial cells (ECs) impairment and dysfunction in vascular intima, which can be alleviated through mobilization of endothelial progenitor cells (EPCs) induced by stromal-cell-derived factor-1α (SDF-1α). A strong inverse correlation between HDL and AS has been proposed. The aim of the present work is to investigate whether 4F, an apolipoprotein A-I (apoA-I, major component protein of HDL) mimic peptide, can upregulate SDF-1α in mice and human umbilical vein endothelial cells (HUVECs) and the underlying mechanism. The protein levels of SDF-1α were measured by ELISA assay. Protein levels of HIF-1α, phosphorylated Akt (p-Akt), and phosphorylated ERK (p-ERK) were evaluated by Western blotting analysis. The results show that L-4F significantly upregulates protein levels of HIF-1α, Akt, and ERK, which can be inhibited by the PI3K inhibitor, LY294002, or ERK inhibitor, PD98059, respectively. Particularly, LY294002 can downregulate the levels of p-ERK, while PD98059 cannot suppress that of p-Akt. D-4F can upregulate the levels of HIF, p-Akt, and p-ERK in the abdominal aorta and inferior vena cava from mice. These results suggest that 4F promotes SDF-1α expression in ECs through PI3K/Akt/ERK/HIF-1α signaling pathway.

Paracrine Role of the Endothelium in Metabolic Homeostasis in Health and Nutrient Excess

The vascular endothelium traditionally viewed as a simple physical barrier between the circulation and tissue is now well-established as a key organ mediating whole organism homeostasis by release of a portfolio of anti-inflammatory and pro-inflammatory vasoactive molecules. Healthy endothelium releases anti-inflammatory signaling molecules such as nitric oxide and prostacyclin; in contrast, diseased endothelium secretes pro-inflammatory signals such as reactive oxygen species, endothelin-1 and tumor necrosis factor-alpha (TNFα). Endothelial dysfunction, which has now been identified as a hallmark of different components of the cardiometabolic syndrome including obesity, type 2 diabetes and hypertension, initiates and drives the progression of tissue damage in these disorders. Recently it has become apparent that, in addition to vasoactive molecules, the vascular endothelium has the potential to secrete a diverse range of small molecules and proteins mediating metabolic processes in adipose tissue (AT), liver, skeletal muscle and the pancreas. AT plays a pivotal role in orchestrating whole-body energy homeostasis and AT dysfunction, characterized by local and systemic inflammation, is central to the metabolic complications of obesity. Thus, understanding and targeting the crosstalk between the endothelium and AT may generate novel therapeutic opportunities for the cardiometabolic syndrome. Here, we provide an overview of the role of the endothelial secretome in controlling the function of AT. The endothelial-derived metabolic regulatory factors are grouped and discussed based on their physical properties and their downstream signaling effects. In addition, we focus on the therapeutic potential of these regulatory factors in treating cardiometabolic syndrome, and discuss areas of future study of potential translatable and clinical significance. The vascular endothelium is emerging as an important paracrine/endocrine organ that secretes regulatory factors in response to nutritional and environmental cues. Endothelial dysfunction may result in imbalanced secretion of these regulatory factors and contribute to the progression of AT and whole body metabolic dysfunction. As the vascular endothelium is the first responder to local nutritional changes and adipocyte-derived signals, future work elucidating the changes in the endothelial secretome is crucial to improve our understanding of the pathophysiology of cardiometabolic disease, and in aiding our development of new therapeutic strategies to treat and prevent cardiometabolic syndrome.

Extracorporeal Cardiac Shock Waves Therapy Improves the Function of Endothelial Progenitor Cells After Hypoxia Injury via Activating PI3K/Akt/eNOS Signal Pathway

Background: Extracorporeal cardiac shock waves (ECSW) have great potential in the treatment of coronary heart disease. Endothelial progenitor cells (EPCs) are a class of pluripotent progenitor cells derived from bone marrow or peripheral blood, which have the capacity to migrate to ischemic myocardium and differentiate into mature endothelial cells and play an important role in neovascularization and endothelial repair. In this study, we investigated whether ECSW therapy can improve EPCs dysfunction and apoptosis induced by hypoxia and explored the underlying mechanisms.

Methods: EPCs were separated from ApoE gene knockout rat bone marrow and identified using flow cytometry and fluorescence staining. EPCs were used to produce in vitro hypoxia-injury models which were then divided into six groups: Control, Hypoxia, Hypoxia + ECSW, Hypoxia + LY294002 + ECSW, Hypoxia + MK-2206 + ECSW, and Hypoxia + L-NAME + ECSW. EPCs from the Control, Hypoxia, and Hypoxia + ECSW groups were used in mRNA sequencing reactions. mRNA and protein expression levels were analyzed using qRT-PCR and western blot analysis, respectively. Proliferation, apoptosis, adhesion, migration, and angiogenesis were measured using CCK-8, flow cytometry, gelatin, transwell, and tube formation, respectively. Nitric oxide (NO) levels were measured using an NO assay kit.

Results: Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis showed that differentially expressed genes were enriched in cancer signaling, PI3K-Akt signaling, and Rap1 signaling pathways. We selected differentially expressed genes in the PI3K-Akt signaling pathway and verified them using a series of experiments. The results showed that ECSW therapy (500 shots at 0.09 mJ/mm²) significantly improved proliferation, adhesion, migration, and tube formation abilities of EPCs following hypoxic injury, accompanied by upregulation of p-PI3K, p-Akt, p-eNOS, Bcl-2 protein and NO, PI3K, and Akt mRNA expression, and downregulation of Bax and Caspase3 protein expression. All these effects of ECSW were eliminated using inhibitors specific to PI3K (LY294002), Akt (MK-2206), and eNOS (L-NAME).

Conclusion: ECSW exerted a strong repaired effect on EPCs suffering inhibited hypoxia injury by inhibiting cell apoptosis and promoting angiogenesis, mainly through activating the PI3K/Akt/eNOS signaling pathway, which provide new evidence for ECSW therapy in CHD.

Diversity of Lipid Function in Atherogenesis: A Focus on Endothelial Mechanobiology

Atherosclerosis is one of the most important problems in modern medicine. Its high prevalence and social significance determine the need for a better understanding of the mechanisms of the disease's development and progression. Lipid metabolism and its disorders are one of the key links in the pathogenesis of atherosclerosis. Lipids are involved in many processes, including those related to the mechanoreception of endothelial cells. The multifaceted role of lipids in endothelial mechanobiology and mechanisms of atherogenesis are discussed in this review. Endothelium is involved in ensuring adequate vascular hemodynamics, and changes in blood flow characteristics are detected by endothelial cells and affect their structure and function.

Flavonoid Composition and Pharmacological Properties of Elaeis guineensis Jacq. Leaf Extracts: A Systematic Review

The oil palm tree (Elaeis guineensis Jacq.) originates from West and Central Africa, and it is cultivated in Malaysia for its oil-producing fruits. Malaysia is the world’s second largest palm oil producer and the world’s largest exporter to date. Consequently, the Malaysian oil palm industry constantly generates a huge amount of biomass with the major contributor being the leaves. A large percentage of these leaves remain underutilized, making them a promising source of raw materials that can be converted into value-added products. The present review summarizes and discusses the flavonoid composition, total phenolic and flavonoid content, and the in vitro and in vivo pharmacological properties exhibited by the extracts of the leaves of E. guineensis. The purpose of this systematic review is to highlight the potential of valorizing the leaf extracts of the oil palm tree as pharmaceutical and cosmeceutical agents.

Challenges and strategies for in situ endothelialization and long-term lumen patency of vascular grafts

Vascular diseases are the most prevalent cause of ischemic necrosis of tissue and organ, which even result in dysfunction and death. Vascular regeneration or artificial vascular graft, as the conventional treatment modality, has received keen attentions. However, small-diameter (diameter < 4 mm) vascular grafts have a high risk of thrombosis and intimal hyperplasia (IH), which makes long-term lumen patency challengeable. Endothelial cells (ECs) form the inner endothelium layer, and are crucial for anti-coagulation and thrombogenesis. Thus, promoting in situ endothelialization in vascular graft remodeling takes top priority, which requires recruitment of endothelia progenitor cells (EPCs), migration, adhesion, proliferation and activation of EPCs and ECs. Chemotaxis aimed at ligands on EPC surface can be utilized for EPC homing, while nanofibrous structure, biocompatible surface and cell-capturing molecules on graft surface can be applied for cell adhesion. Moreover, cell orientation can be regulated by topography of scaffold, and cell bioactivity can be modulated by growth factors and therapeutic genes. Additionally, surface modification can also reduce thrombogenesis, and some drug release can inhibit IH. Considering the influence of macrophages on ECs and smooth muscle cells (SMCs), scaffolds loaded with drugs that can promote M2 polarization are alternative strategies. In conclusion, the advanced strategies for enhanced long-term lumen patency of vascular grafts are summarized in this review. Strategies for recruitment of EPCs, adhesion, proliferation and activation of EPCs and ECs, anti-thrombogenesis, anti-IH, and immunomodulation are discussed. Ideal vascular grafts with appropriate surface modification, loading and fabrication strategies are required in further studies.

Berries and Their Polyphenols as a Potential Therapy for Coronary Microvascular Dysfunction: A Mini-Review

Ischemia with no obstructive coronary artery disease (INOCA) is a common diagnosis with a higher prevalence in women compared to men. Despite the absence of obstructive coronary artery disease and no structural heart disease, INOCA is associated with major adverse cardiovascular outcomes as well a significant contributor to angina and related disability. A major feature of INOCA is coronary microvascular dysfunction (CMD), which can be detected by non-invasive imaging and invasive coronary physiology assessments in humans. CMD is associated with epicardial endothelial-dependent and -independent dysfunction, diffuse atherosclerosis, and left-ventricular hypertrophy, all of which lead to insufficient blood flow to the myocardium. Inflammatory and oxidative stress signaling, upregulation of the renin-angiotensin-aldosterone system and adrenergic receptor signaling are major drivers of CMD. Treatment of CMD centers around addressing cardiovascular risk factors; however, there are limited treatment options for those who do not respond to traditional anti-anginal therapies. In this review, we highlight the ability of berry-derived polyphenols to modulate those pathways. The evidence supports the need for future clinical trials to investigate the effectiveness of berries and their polyphenols in the treatment of CMD in INOCA patients.

The Potential Role of Creatine in Vascular Health

Creatine is an organic compound, consumed exogenously in the diet and synthesized endogenously via an intricate inter-organ process. Functioning in conjunction with creatine kinase, creatine has long been known for its pivotal role in cellular energy provision and energy shuttling. In addition to the abundance of evidence supporting the ergogenic benefits of creatine supplementation, recent evidence suggests a far broader application for creatine within various myopathies, neurodegenerative diseases, and other pathologies. Furthermore, creatine has been found to exhibit non-energy related properties, contributing as a possible direct and in-direct antioxidant and eliciting anti-inflammatory effects. In spite of the new clinical success of supplemental creatine, there is little scientific insight into the potential effects of creatine on cardiovascular disease (CVD), the leading cause of mortality. Taking into consideration the non-energy related actions of creatine, highlighted in this review, it can be speculated that creatine supplementation may serve as an adjuvant therapy for the management of vascular health in at-risk populations. This review, therefore, not only aims to summarize the current literature surrounding creatine and vascular health, but to also shed light onto the potential mechanisms in which creatine may be able to serve as a beneficial supplement capable of imparting vascular-protective properties and promoting vascular health.

Beta-Arrestins and Receptor Signaling in the Vascular Endothelium

The vascular endothelium is the innermost layer of blood vessels and is a key regulator of vascular tone. Endothelial function is controlled by receptor signaling through G protein-coupled receptors, receptor tyrosine kinases and receptor serine-threonine kinases. The β-arrestins, multifunctional adapter proteins, have the potential to regulate all of these receptor families, although it is unclear as to whether they serve to integrate signaling across all of these different axes. Notably, the β-arrestins have been shown to regulate signaling by a number of receptors important in endothelial function, such as chemokine receptors and receptors for vasoactive substances such as angiotensin II, endothelin-1 and prostaglandins. β-arrestin-mediated signaling pathways have been shown to play central roles in pathways that control vasodilation, cell proliferation, migration, and immune function. At this time, the physiological impact of this signaling has not been studied in detail, but a deeper understanding of it could lead to the development of novel therapies for the treatment of vascular disease.

Validation of semi-automated flow-mediated dilation measurement in healthy volunteers

BACKGROUND

Flow-mediated dilation (FMD) is a non-invasive imaging modality used to measure endothelial function but has significant intra- and inter-observer variability. The use of semi-automated FMD devices could overcome this limitation. We assessed the reproducibility of same-day semi-automated FMD measurements by investigators who received basic training on the correct use of the device.

METHODS

Forty-three healthy volunteers had two brachial artery FMD measurements performed 20 minutes apart using the UNEX EF 38G device, and automated outputs were produced. Images were also manually analysed using edge-detection software. The reproducibility of repeat FMD measurements within individuals was compared for automated and manual readings, and the correlation between analytical techniques was calculated.

RESULTS

Twenty-five percent of scans were of non-diagnostic quality (n = 32). Automated analyses demonstrated sub-optimal reproducibility and measurement variability [intraclass correlation coefficient (ICCC) = 0.334, coefficient of variation (CV) = 45.87%]. In contrast, manually analysed scans had excellent reproducibility and low measurement variance (ICCC = 0.815, CV = 11.40%). FMD values obtained from automated and manual analysis correlated poorly (r = 0.164), whereas resting (r = 0.955) and maximal brachial artery diameters demonstrated excellent correlation (r = 0.867).

CONCLUSION

Manually evaluated serial UNEX EF readings have good reproducibility and therefore, the optimal FMD workflow involves manual analyses prior to independent automated interrogation. The high non-diagnostic scan rate is most likely the result of insufficient training and indicates that semi-automatic devices such as UNEX EF should be used by experienced investigators to achieve optimal results.

Liraglutide promotes the angiogenic ability of human umbilical vein endothelial cells through the JAK2/STAT3 signaling pathway

Liraglutide is a glucagon-like peptide-1 receptor (GLP-1R) agonist and incretin mimetic used for the treatment of Type 2 diabetes mellitus. It has also been shown to have a beneficial role in the cardiovascular system. Here, we investigated the mechanism by which liraglutide promotes angiogenesis using human umbilical vein endothelial cells (HUVECs). HUVECs were treated with various concentrations of liraglutide, and assessed by wound healing assay and tube formation assay as measures of angiogenesis. We found that liraglutide at 10 and 100 nmol/L greatly promoted the angiogenic ability of HUVECs. Next, we examined the JAK2/STAT3 signaling pathway and found that liraglutide treatment led to JAK2/STAT3 activation and significant increase in the angiogenic mediator expressions, including vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and endothelial nitric oxide synthase (eNOS) in HUVECs. Treatment with JAK2 inhibitor, AG490, in HUVECs successfully reduced the observed effects of liraglutide. We conclude that liraglutide promotes the angiogenic ability of HUVECs by activating the JAK2/STAT3 signaling pathway and upregulating its downstream factors, VEGF, bFGF and eNOS. Thus, liraglutide may provide ischemic relief for diabetic patients with cardiovascular diseases in addition to glycemic control.

A Brief Overview of lncRNAs in Endothelial Dysfunction-Associated Diseases: From Discovery to Characterization

Long non-coding RNAs (lncRNAs) are a novel class of regulatory RNA molecules and they are involved in many biological processes and disease developments. Several unique features of lncRNAs have been identified, such as tissue-and/or cell-specific expression pattern, which suggest that they could be potential candidates for therapeutic and diagnostic applications. More recently, the scope of lncRNA studies has been extended to endothelial biology research. Many of lncRNAs were found to be critically involved in the regulation of endothelial function and its associated disease progression. An improved understanding of endothelial biology can thus facilitate the discovery of novel biomarkers and therapeutic targets for endothelial dysfunction-associated diseases, such as abnormal angiogenesis, hypertension, diabetes, and atherosclerosis. Nevertheless, the underlying mechanism of lncRNA remains undefined in previous published studies. Therefore, in this review, we aimed to discuss the current methodologies for discovering and investigating the functions of lncRNAs and, in particular, to address the functions of selected lncRNAs in endothelial dysfunction-associated diseases.

Sphingosine-1-Phosphate Improves the Biological Features of Mouse Bone Marrow-Derived EPCs Partially through PI3K/AKT/eNOS/NO Pathway

Sphingosine-1-phosphate (S1P), a bioactive sphingolipid, is recognized as a critical regulator in physiological and pathophysiological processes of atherosclerosis (AS). However, the underlying mechanism remains unclear. As the precursor cells of endothelial cells (ECs), endothelial progenitor cells (EPCs) can prevent AS development through repairing endothelial monolayer impaired by proatherogenic factors. The present study investigated the effects of S1P on the biological features of mouse bone marrow-derived EPCs and the underlying mechanism. The results showed that S1P improved cell viability, adhesion, and nitric oxide (NO) release of EPCs in a bell-shaped manner, and migration and tube formation dose-dependently. The aforementioned beneficial effects of S1P on EPCs could be inhibited by the phosphatidylinositol 3-kinase (PI3K) inhibitor of LY294002 and nitric oxide synthase (NOS) inhibitor of N’-nitro-L-arginine-methyl ester hydrochloride (L-NAME). The inhibitor of LY294002 inhibited S1P-stimulated activation of phosphorylated protein kinase B (AKT) (p-AKT) and endothelial nitric oxide synthase (eNOS) (p-eNOS), and down-regulated the level of eNOS significantly. The results suggest that S1P improves the biological features of EPCs partially through PI3K/AKT/eNOS/NO signaling pathway.

Coronary Artery Vasospasm Induced by 5-fluorouracil: Proposed Mechanisms, Existing Management Options and Future Directions

Cardiovascular disease and cancer are leading contributors to the global disease burden. As a result of cancer therapy-related cardiotoxicities, cardiovascular disease results in significant morbidity and mortality in cancer survivors and patients with active cancer. There is an unmet need for management of cardio-oncology conditions, which is predicted to reach epidemic proportions, and better understanding of their pathophysiology and treatment is urgently required. The proposed mechanisms underlying cardiotoxicity induced by 5-fluorouracil (5-FU) are vascular endothelial damage followed by thrombus formation, ischaemia secondary to coronary artery vasospasm, direct toxicity on myocardium and thrombogenicity. In patients with angina and electrocardiographic evidence of myocardial ischaemia due to chemotherapy-related coronary artery vasospasm, termination of chemotherapy and administration of calcium channel blockers or nitrates can improve ischaemic symptoms. However, coronary artery vasospasm can reoccur with 5-FU re-administration with limited effectiveness of vasodilator prophylaxis observed. While pre-existing coronary artery disease may increase the ischaemic potential of 5-FU, cardiovascular risk factors do not appear to completely predict the development of cardiac complications. Pharmacogenomic studies and genetic profiling may help predict the occurrence and streamline the treatment of 5-FU-induced coronary artery vasospasm. Echocardiographic measures such as the Tei index may help detect subclinical 5-FU cardiotoxicity. Further research is required to explore the cardioprotective effect of agents such as coenzyme complex, GLP-1 analogues and degradation inhibitors on 5-FU-induced coronary artery vasospasm.

Value of flaccid penile ultrasound in screening for arteriogenic impotence: a preliminary prospective study

Background

This prospective study is to evaluate the potential value of sonographic measurements in the flaccid penis for the screening of arteriogenic impotence.

Methods

A consecutive series of 260 Chinese males consulting for sexual dysfunction and 54 controls underwent sonographic examination. The sonographic parameters were correlated with the clinical gold standards, including the international index of erectile function (IIEF) and penile erectile hardness grading scale (EHGS). The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and area under the receiver operating characteristic curve (AUROC) of flaccid peak systolic velocity (PSV) in predicting patients with normal function were analyzed.

Results

The mean cavernous PSV of both sides in the patients with sexual dysfunction ranged from 7.76 to 11.12 cm/sec with a stepwise increase in IIEF and EHGS grading scale (P < .05). The cutoff value of flaccid PSV for the differential diagnosis of grade 4 of IIEF-5 or EHGS was 8.20–8.90 cm/sec, with an AUROC of 0.657–0.724, specificity of 82.96–86.84% and PPV of 95.20–96.60%, respectively.

Conclusions

This simple flaccid PSV measurement is a specific tool for screening arteriogenic impotence.

5-fluorouracil and cardiotoxicity: a review

Fluoropyrimidines such as 5-fluorouracil (5-FU) form the foundation of a wide variety of chemotherapy regimens. 5-FU is in fact the third most commonly used chemotherapeutic agent in the treatment of solid malignancies across the world. As with all chemotherapy, balancing the potential benefits of therapy against the risks of drug-related toxicity is crucial when clinicians and patients make shared decisions about treatment. 5-FU is the second most common chemotherapeutic drug associated with cardiotoxicity after anthracyclines, which can manifest as chest pain, acute coronary syndrome/myocardial infarction or death. Nevertheless a widespread appreciation of 5-FU-related cardiotoxicity and its implications is lacking amongst clinicians. In this review, we outline the incidence, possible risk factors, and likely pathophysiological mechanisms that may account for 5-FU-related cardiotoxicity and also highlight potential management strategies for this poorly understood clinical entity.

Effects of ivabradine on endothelial function, aortic properties and ventricular-arterial coupling in chronic systolic heart failure patients

AIM

Heart rate (HR) is an important prognostic factor in patients affected by chronic heart failure (CHF); ivabradine has been demonstrated to significantly reduce nonfatal myocardial infarction and hospitalization rate for acute heart failure and to improve left ventricular (LV) reverse remodeling, quality of life, exercise capacity, and arterial elastance (Ea) in these patients. We aimed at evaluating the short-term effects of ivabradine on ventricular-arterial coupling (VAC), aortic stiffness, and endothelial function in stable patients with CHF.

METHODS

We evaluated 30 consecutive CHF patients (LVEF≤ 35%, NYHA class II) with sinus rhythm and HR ≥ 70 bpm on optimized pharmacological therapy. All of them underwent both transthoracic echocardiogram to assess aortic elastic properties (aortic distensibility, AD; aortic stiffness index, ASI; systolic aortic strain, SAS) and VAC, and peripheral arterial tonometry to measure endothelial function. Therapy with ivabradine 5 mg bid was added and each patient was evaluated with the same examinations after 4 months.

RESULTS

At the baseline, 73% of patients had impaired VAC and 63% endothelial dysfunction. After 4 months, there was a significant improvement in the VAC value (ΔVAC -0.10 ± 0.18, P = .021), mainly linked to Ea (ΔEa -0.40 ± 0.23 mm Hg/mL; P = .003). All the parameters of aortic elasticity underwent significant improvement (ΔAD 1.82 ± 1.43 cm² × dyn^- ¹, P = .004; ΔASI -4.73 ± 6.07, P = .033; ΔSAS -7.98 ± 4.37%, P = .003). Lastly, we also noted a significant improvement of endothelial function (Δ RHI 0.35 ± 0.35; P < .001). At follow-up 40% of patients had impaired VAC (P = .018) and 33% endothelial dysfunction (P = .038).

CONCLUSION

In patients with CHF adding ivabradine on top to the standard optimized medical therapy, when indicated, seems to improve endothelial function, aortic properties, and VAC.

Roles of Cells from the Arterial Vessel Wall in Atherosclerosis

Atherosclerosis has been identified as a chronic inflammatory disease of the arterial vessel wall. Accumulating evidence indicates that different cells from the tunica intima, media, adventitia, and perivascular adipose tissue not only comprise the intact and normal arterial vessel wall but also participate all in the inflammatory response of atherosclerosis via multiple intricate pathways. For instance, endothelial dysfunction has historically been considered to be the initiator of the development of atherosclerosis. The migration and proliferation of smooth muscle cells also play a pivotal role in the progression of atherosclerosis. Additionally, the fibroblasts from the adventitia and adipocytes from perivascular adipose tissue have received considerable attention given their special functions that contribute to atherosclerosis. In addition, numerous types of cytokines produced by different cells from the arterial vessel wall, including endothelium-derived relaxing factors, endothelium-derived contracting factors, tumor necrosis factors, interleukin, adhesion molecules, interferon, and adventitium-derived relaxing factors, have been implicated in atherosclerosis. Herein, we summarize the possible roles of different cells from the entire arterial vessel wall in the pathogenesis of atherosclerosis.

Treatment response to sildenafil in men with erectile dysfunction relative to concomitant comorbidities and age

AIM

To evaluate treatment response in men with erectile dysfunction (ED) and concomitant comorbidities.

METHODS

Data were pooled from 42 placebo-controlled, flexible-dose sildenafil trials. In most trials, the sildenafil dose was 50 mg, taken ~1 hour before sexual activity but not more than once daily, with adjustment to 100 or 25 mg as needed. The overall population (N=9413) was stratified by age (<45, 46-64, ≥65 years). Treatment response was defined as a minimal clinically important difference (MCID) from baseline in the International Index of Erectile Function-Erectile Function (IIEF-EF) domain score of >2, >5 and >7 for men with mild, moderate and severe ED at baseline, respectively, or an IIEF-EF domain score ≥26 (no ED) at end-point.

RESULTS

In the overall population, treatment response using the IIEF-EF MCID definition was significantly greater (P<.0001) with sildenafil vs placebo in men with no comorbidity (77% vs 33%), cardiovascular disease/hypertension only (71% vs 27%), diabetes only (63% vs 24%) or depression only (78% vs 29%). Using an IIEF-EF score ≥26, treatment response was significantly greater (P<.0001) with sildenafil vs placebo in men with no comorbidity (49% vs 17%), cardiovascular disease/hypertension only (48% vs 12%), diabetes only (40% vs 12%) or depression only (60% vs 17%). With each definition, the treatment response for each age and comorbidity was significantly greater (P≤.0065) with sildenafil vs placebo.

CONCLUSION

The treatment response was significantly greater with sildenafil vs placebo in men with ED and each comorbidity regardless of age.

In situ Endothelialization: Bioengineering Considerations to Translation

Improving patency rates of current cardiovascular implants remains a major challenge. It is widely accepted that regeneration of a healthy endothelium layer on biomaterials could yield the perfect blood-contacting surface. Earlier efforts in pre-seeding endothelial cells in vitro demonstrated success in enhancing patency, but translation to the clinic is largely hampered due to its impracticality. In situ endothelialization, which aims to create biomaterial surfaces capable of self-endothelializing upon implantation, appears to be an extremely promising solution, particularly with the utilization of endothelial progenitor cells (EPCs). Nevertheless, controlling cell behavior in situ using immobilized biomolecules or physical patterning can be complex, thus warranting careful consideration. This review aims to provide valuable insight into the rationale and recent developments in biomaterial strategies to enhance in situ endothelialization. In particular, a discussion on the important bio-/nanoengineering considerations and lessons learnt from clinical trials are presented to aid the future translation of this exciting paradigm.

The glutathione mimic ebselen inhibits oxidative stress but not endoplasmic reticulum stress in endothelial cells

AIMS

Reactive oxygen species are associated with cardiovascular disease, diabetes, and atherosclerosis, yet the use of antioxidants in clinical trials has been ineffective at improving outcomes. In endothelial cells, high-dextrose-induced oxidative stress and endoplasmic reticulum stress promote endothelial dysfunction leading to the recruitment and activation of peripheral blood lymphocytes and the breakdown of barrier function. Ebselen, a glutathione peroxidase 1 (GPX1) mimic, has been shown to improve β-cell function in diabetes and prevent atherosclerosis.

MAIN METHODS

To determine if ebselen inhibits both oxidative stress and endoplasmic reticulum (ER) stress in endothelial cells, we examined its effects in human umbilical vein endothelial cells (HUVEC) and human coronary artery endothelial cells (HCAEC) with and without high-dextrose. Oxidative stress and ER stress were measured by 2-methyl-6-(4-methoxyphenyl)-3,7-dihydroimidazo[1,2-A]pyrazin-3-one hydrochloride chemiluminescence and ER stress alkaline phosphatase assays, respectively. GPX1 over-expression and knockdown were performed by transfecting cells with a GPX1 expression construct or a GPX1-specific siRNA, respectively.

KEY FINDINGS

Ebselen inhibited dextrose-induced oxidative stress but not ER stress in both HUVEC and HCAEC. Ebselen also had no effect on tunicamycin-induced ER stress in HCAEC. Furthermore, augmentation of GPX1 activity directly by sodium selenite supplementation or transfection of a GPX1 expression plasmid decreased dextrose-induced oxidative stress but not ER stress, while GPX1 knockout enhanced oxidative stress but had no effect on ER stress.

SIGNIFICANCE

These results suggest that ebselen targets only oxidative stress but not ER stress.

Vascular endothelial function of patients with stable coronary artery disease

Objectives:

To evaluate vascular endothelial function and contributing factors in coronary heart disease (CHD) patients.

Methods:

One hundred twenty six CHD outpatients were randomly recruited. Reactive hyperemia index (RHI) <1.67 indicates endothelial dysfunction. Correlation between RHI and different biochemical parameters was evaluated.

Results:

RHI in patients receiving statins treatment was significantly higher than patients without statins treatment (P<0.05). RHI in patients with more than 3 risk factors for CHD was also markedly lower than that in patients with ≤2 risk factors (P<0.05). Patients with lesions at several branches of coronary artery had a markedly lower RHI when compared with those with coronary lesions at a single branch (P<0.05). For patients without statins treatment, RHI increased significantly after statins treatment for 1 month (P=0.01). In patients with endothelial dysfunction, FBG, HbA1C, hs-CRP and Hcy were significantly higher than those in patients with normal endothelial function (P<0.05 for all). Smokers with CHD had a remarkably lower RHI when compared with non-smokers (P<0.05).

Conclusions:

Smoking, FBG, HbA1C, Hcy and hs-CRP are significantly associated with endothelial dysfunction. Endothelial dysfunction is also related to the numbers of risk factors for CHD, degree of coronary lesions and statins. Statins treatment may significantly improve the endothelial function of CHD patients.