Endothelial microparticles prevent lipid-induced endothelial damage via Akt/eNOS signaling and reduced oxidative stress

Insight into endothelial cell-derived extracellular vesicles in cardiovascular disease: Molecular mechanisms and Clinical implications

The endothelium is crucial in regulating vascular function. Extracellular vesicles (EVs) serve as membranous structures released by cells to facilitate intercellular communication through the delivery of nucleic acids, lipids, and proteins to recipient cells in an paracrine or endocrine manner. Endothelial cell-derived EVs (EndoEVs) have been identified as both biomarkers and significant contributors to the occurrence and progression of cardiovascular disease (CVD). The impact of EndoEVs on CVD is complex and contingent upon the condition of donor cells, the molecular cargo within EVs, and the characteristics of recipient cells. Consequently, elucidating the underlying molecular mechanisms of EndoEVs is crucial for comprehending their contributions to CVD. Moreover, a thorough understanding of the composition and function of EndoEVs is imperative for their potential clinical utility. This review aims provide an up-to-date overview of EndoEVs in the context of physiology and pathophysiology, as well as to discuss their prospective clinical applications.

Extracellular vesicles and their effect on vascular haemodynamics: a systematic review

Extracellular vesicles (EVs) are released from all cell types studied to date and act as intercellular communicators containing proteins, nucleic acids and lipid cargos. They have been shown to be involved in maintaining homoeostasis as well as playing a role in the development of pathology including hypertension and cardiovascular disease. It is estimated that there is 109-1010 circulating EVs/mL in the plasma of healthy individuals derived from various sources. While the effect of EVs on vascular haemodynamic parameters will be dependent on the details of the model studied, we systematically searched and summarized current literature to find patterns in how exogenously injected EVs affected vascular haemodynamics. Under homoeostatic conditions, evidence from wire and pressure myography data demonstrate that injecting isolated EVs derived from cell types found in blood and blood vessels resulted in the impairment of vasodilation in blood vessels ex vivo. Impaired vasodilation was also observed in rodents receiving intravenous injections of human plasma EVs from cardiovascular diseases including valvular heart disease, acute coronary syndrome, myocardial infarction and end stage renal disease. When EVs were derived from models of metabolic syndromes, such as diabetes, these EVs enhanced vasoconstriction responses in blood vessels ex vivo. There were fewer publications that assessed the effect of EVs in anaesthetised or conscious animals to confirm whether effects on the vasculature observed in ex vivo studies translated into alterations in vascular haemodynamics in vivo. In the available conscious animal studies, the in vivo data did not always align with the ex vivo data. This highlights the importance of in vivo work to determine the effects of EVs on the integrative vascular haemodynamics.

Exploring platelet-derived microvesicles in vascular regeneration: unraveling the intricate mechanisms and molecular mediators

Microvesicles (MVs) serve as biomarkers and transmitters for cell communication and also act as essential contributors to diseases. Platelets release microvesicles when activated voluntarily, making them a significant source. Platelet-derived microvesicles possess a range of characteristics similar to their parent cells and were shown to exert regulatory impacts on vascular and immunological cells. MVs can alter the activity of recipient cells by transferring their internal components. Furthermore, it has been identified that microvesicles derived from platelets possess the ability to exert immunomodulatory effects on different kinds of cells. Recent research has shown that microvesicles have a bidirectional influence of harming and preventing the receptor cells. Nevertheless, the specific characteristics of the active molecules responsible for this phenomenon are still unknown. The primary focus of this review was to explore the mechanism of vascular tissue regeneration and the specific molecules that play a role in mediating various biological effects throughout this process. These molecules exert their effects by influencing autophagy, apoptosis, and inflammatory pathways.

Utilizing Extracellular Vesicles for Eliminating 'Unwanted Molecules': Harnessing Nature's Structures in Modern Therapeutic Strategies

Extracellular vesicles (EVs) are small phospholipid bilayer-bond structures released by diverse cell types into the extracellular environment, maintaining homeostasis of the cell by balancing cellular stress. This article provides a comprehensive overview of extracellular vesicles, their heterogeneity, and diversified roles in cellular processes, emphasizing their importance in the elimination of unwanted molecules. They play a role in regulating oxidative stress, particularly by discarding oxidized toxic molecules. Furthermore, endoplasmic reticulum stress induces the release of EVs, contributing to distinct results, including autophagy or ER stress transmission to following cells. ER stress-induced autophagy is a part of unfolded protein response (UPR) and protects cells from ER stress-related apoptosis. Mitochondrial-derived vesicles (MDVs) also play a role in maintaining homeostasis, as they carry damaged mitochondrial components, thereby preventing inflammation. Moreover, EVs partake in regulating aging-related processes, and therefore they can potentially play a crucial role in anti-aging therapies, including the treatment of age-related diseases such as Alzheimer's disease or cardiovascular conditions. Overall, the purpose of this article is to provide a better understanding of EVs as significant mediators in both physiological and pathological processes, and to shed light on their potential for therapeutic interventions targeting EV-mediated pathways in various pathological conditions, with an emphasis on age-related diseases.

Endothelial exosomes work as a functional mediator to activate macrophages

Introduction

Intercellular communication is essential for almost all physiological and pathological processes. Endothelial cell (EC)-derived exosomes, working as mediators for intercellular information exchange, are involved in the pathophysiological mechanisms of atherosclerosis. However, the effect of inflamed endothelial exosomes on the function of macrophages (Mϕ) is poorly defined. This study aims to unravel how exosomes derived from tumor necrosis factor-α (TNF-α)-stimulated ECs (exo-T) affect Mϕ in vitro.

Methods and results

Exosomes derived from untreated ECs (exo) and exo-T were identified by using TEM, NTA, and western blot, and we observed that PKH67-labeled exo/exo-T were taken up by Mϕ. Exposure to exo-T for 24 h not only skewed Mϕ to the M1 subtype and exacerbated lipid deposition, but also promoted Mϕ apoptosis, while it did not significantly affect Mϕ migration, as detected by RT-qPCR, Dil-ox-LDL uptake assay, flow cytometry, wound healing assay, and transwell assay, respectively. In addition, exo/exo-T-related microRNA-Seq revealed 104 significantly differentially expressed microRNAs (DE-miRNAs). The target genes of DE-miRNAs were mainly enriched functionally in metabolic pathways, MAPK signaling pathway, etc., as determined using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses. We further demonstrated by immunoblotting that exo-T intervention improves the phosphorylation of MAPK/NF-κB-related proteins.

Discussion and conclusion

Collectively, this study reveals that inflamed endothelial exosomes (TNF-α-stimulated EC-derived exosomes) work as a functional mediator to affect Mϕ function and may activate Mϕ through MAPK/NF-κB signaling pathways.

Endothelial-Related Biomarkers in Evaluation of Vascular Function During Progression of Sepsis After Severe Trauma: New Potential Diagnostic Tools in Sepsis

Purpose

This study aimed to investigate the changes in endothelial-related biomarkers and their relationship with the incidence and prognosis of patients with sepsis after severe trauma.

Methods

A total of 37 severe trauma patients admitted to our hospital from Jan. to Dec. 2020 were enrolled in our research. All enrolled patients were divided into the sepsis and the non-sepsis groups. Endothelial progenitor cells (EPCs), circulating endothelial cells (CECs), and endothelial microparticles (EMPs) were detected on admission time; 24-48 hours and 48-72 hours after admission respectively. Demographic data, Acute Physiology, Chronic Health Evaluation (APACHE) II, and Sequential Organ Failure Assessment (SOFA) score were calculated every 24 h of admission to assess the severity of organ dysfunction. Receiver operating characteristic (ROC) curves were drawn to compare the areas under the curve (AUC) of endothelial-related biomarkers for the diagnosis of sepsis.

Results

The incidence rate of sepsis was 45.95% in all patients. The SOFA score in the sepsis group was significantly higher than that in the non-sepsis group (2 points vs 0 points, P<0.01). The number of EPCs, CECs, and EMPs all rose quickly in the early phase after trauma. The number of EPCs was similar in both groups, but the number of CECs and EMPs in the Sepsis Group was much higher than in the non-Sepsis Group (all P<0.01). Logistic regression analysis showed that the occurrence of sepsis was closely related to the expression of 0-24h CECs and 0-24h EMPs. The AUC ROC for CECs in different time periods were 0.815, 0.877, and 0.882, respectively (all P<0.001). The AUC ROC for EMPs in 0-24h was 0.868 (P=0.005).

Conclusion

The expression of EMPs was higher in early severe trauma, and high levels of EMPs were significantly higher in patients with early sepsis and poor prognosis.

Integrative pharmacology reveals the mechanisms of Erzhi Pill, a traditional Chinese formulation, against diabetic cardiomyopathy

ETHNOPHARMACOLOGICAL RELEVANCE

Erzhi Pill (EZP) is a traditional Chinese prescription that has marked effects in treating type 2 diabetes mellitus and diabetic nephropathy. However, its underlying pharmacological mechanisms in the treatment of diabetic cardiomyopathy (DCM), remain to be elucidated.

AIM OF THE STUDY

This study aimed to apply an integrative pharmacological strategy to systematically evaluate the pharmacological effects and molecular mechanisms of EZP, and provide a solid theoretical basis for the clinical application of EZP in the treatment of DCM.

MATERIALS AND METHODS

In this study, the potential targets and key pathways of EZP were predicted and validated using network pharmacology and molecular docking, respectively. Changes in cardiac metabolites and major metabolic pathways in rat heart samples were examined using ¹H-nuclear magnetic resonance (NMR) metabolomics. Finally, biochemical analysis was conducted to detect the protein expression levels of key pathways.

RESULTS

We found that EZP decreased fasting blood glucose (FBG), triglycerides (TG), total cholesterol (TC), and low-density lipoprotein (LDL) levels, increased high-density lipoprotein (HDL) levels in the serum, and alleviated the morphological abnormalities of the heart tissue in diabetic rats. Furthermore, EZP effectively restored superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), caspase-3, caspase-8, and caspase-9 activity levels, as well as the levels of reactive oxygen species (ROS), malondialdehyde (MDA), B-cell lymphoma (Bcl)-2, and Bcl-2-associated X protein (Bax) in the heart tissue. Network pharmacology prediction results indicated that the mechanism of EZP in treating DCM was closely related to apoptosis, oxidative stress, and the HIF-1, PI3K-Akt, and FoxO signaling pathways. In addition, ¹H-NMR metabolomics confirmed that EZP primarily regulated both energy metabolism and amino acid metabolism, including the tricarboxylic acid (TCA) cycle, ketone bodies metabolism, glutamine and glutamate metabolism, glycine metabolism, and purine metabolism. Finally, immunohistochemistry results indicated that EZP reduced the expression levels of p-AMPK, p-PI3K, p-Akt, and p-FoxO3a proteins, in the heart tissue of DCM rats.

CONCLUSION

The results confirmed that the overall therapeutic effect of EZP in the DCM rat model is exerted via inhibition of oxidative stress and apoptosis, alongside the regulation of energy metabolism and amino acid metabolism, as well as the AMPK and PI3K/Akt/FoxO3a signaling pathways. This study provides an experimental basis for the use of EZP in DCM treatment.

Endothelial microparticles: A mechanosensitive regulator of vascular homeostasis and injury under shear stress

Hemodynamic shear stress (SS), a frictional force generated by blood flow, regulates vascular homeostasis. High and steady SS maintains physiological function of endothelial cells while low and disturbed SS promotes disturbance of vascular homeostasis and the development of atherosclerosis. Endothelial microparticle (EMP), a vesicular structure shed from endothelial cells, has emerged as a surrogate biomarker of endothelial injury and dysfunction. EMP release is triggered by disturbed SS in addition to multiple inflammatory cytokines. This review systematically summarizes the impact of SS on EMPs and the role of EMPs under SS in modulating vascular homeostasis and injury, including endothelial survival, vasodilation, inflammatory response, vascular permeability, and coagulation system.

Extracellular vesicles in vascular remodeling

Vascular remodeling contributes to the development of a variety of vascular diseases including hypertension and atherosclerosis. Phenotypic transformation of vascular cells, oxidative stress, inflammation and vascular calcification are closely associated with vascular remodeling. Extracellular vesicles (EVs) are naturally released from almost all types of cells and can be detected in nearly all body fluids including blood and urine. EVs affect vascular oxidative stress, inflammation, calcification, and lipid plaque formation; and thereby impact vascular remodeling in a variety of cardiovascular diseases. EVs may be used as biomarkers for diagnosis and prognosis, and therapeutic strategies for vascular remodeling and cardiovascular diseases. This review includes a comprehensive analysis of the roles of EVs in the vascular remodeling in vascular diseases, and the prospects of EVs in the diagnosis and treatment of vascular diseases.

Extracellular vesicle-induced cyclic AMP signaling

Second messenger signaling is required for cellular processes. We previously reported that extracellular vesicles (EVs) from stimulated cultured endothelial cells contain the biochemical second messenger, cAMP. In the current study, we sought to determine whether cAMP-enriched EVs induce second messenger signaling pathways in naïve recipient cells. Our results indicate that cAMP-enriched EVs increase cAMP content sufficient to stimulate PKA activity. The implications of our work are that EVs represent a novel intercellular mechanism for second messenger, specifically cAMP, signaling.

The Endothelium and COVID-19: An Increasingly Clear Link Brief Title: Endotheliopathy in COVID-19

The endothelium has a fundamental role in the cardiovascular complications of coronavirus disease 2019 (COVID-19). Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) particularly affects endothelial cells. The virus binds to the angiotensin-converting enzyme 2 (ACE-2) receptor (present on type 2 alveolar cells, bronchial epithelial cells, and endothelial cells), and induces a cytokine storm. The cytokines tumor necrosis factor alpha, interleukin-1 beta, and interleukin-6 have particular effects on endothelial cells-leading to endothelial dysfunction, endothelial cell death, changes in tight junctions, and vascular hyperpermeability. Under normal conditions, apoptotic endothelial cells are removed into the bloodstream. During COVID-19, however, endothelial cells are detached more rapidly, and do not regenerate as effectively as usual. The loss of the endothelium on the luminal surface abolishes all of the vascular responses mediated by the endothelium and nitric oxide production in particular, which results in greater contractility. Moreover, circulating endothelial cells infected with SARS-CoV-2 act as vectors for viral dissemination by forming clusters that migrate into the circulation and reach distant organs. The cell clusters and the endothelial dysfunction might contribute to the various thromboembolic pathologies observed in COVID-19 by inducing the formation of intravascular microthrombi, as well as by triggering disseminated intravascular coagulation. Here, we review the contributions of endotheliopathy and endothelial-cell-derived extracellular vesicles to the pathogenesis of COVID-19, and discuss therapeutic strategies that target the endothelium in patients with COVID-19.

A κ-OR Agonist Protects the Endothelial Function Impaired by Hyperuricemia Through Regulating the Akt/eNOS Signal Pathway

To investigate the effects of κ-OR agonist on hyperuricemia rats and injured endothelial function, as well as the underlying mechanism. A hyperuricemia model was established on rats. The endothelial protective effects of U50,488H were evaluated and compared to the controlled groups. The protein levels of eNOS, p-eNOS, Akt, and p-Akt were determined using western blot analysis. ELISA was employed to measure the expression of soluble ET-1, ICAM-1, TNF-α, and NO in cell supernatants and rat serum samples. Cell migration and the artery tension were determined by in vitro functional assays. The suppressed production of ET-1, ICAM-1, and NO in the hyperuricemia rats was promoted by the treatment of U50,488H, which was reversed by the co-administration of nor-BNI. P-eNOS/eNOS and p-Akt/Akt were up-regulated by the incubation of serum from hyperuricemia rats, which was down-regulated by the introduction of U50,488H. The vascular tension of vessels incubated with U50,488H was higher than the baseline in the presence of ACh, which was lower than baseline in the presence of SNAP. U50,488H significantly promoted the release of ET-1, ICAM-1, and NO, and inhibited the release of TNF-α from endothelial cells and the migration ability of neutrophils in the presence of hyperuricemia rat serum, which were reversed by the co-incubation with nor-BNI, Akt inhibitor or L-NAME. U50,488H protected the endothelial function impaired by hyperuricemia through regulating the Akt/eNOS signal pathway.

Umbelliferone prevents isoproterenol-induced myocardial injury by upregulating Nrf2/HO-1 signaling, and attenuating oxidative stress, inflammation, and cell death in rats

The role of oxidative injury and inflammatory response in cardiovascular diseases and heart failure has been well-acknowledged. This study evaluated the protective effect of umbelliferone (UMB), a coumarin with promising radical scavenging and anti-inflammatory activities, on myocardial injury induced by isoproterenol (ISO) in rats. Rats received 50 mg/kg UMB orally for 14 days and 85 mg/kg ISO twice at an interval of 24 h. Administration of ISO elevated serum troponin I, creatine kinase-MB and lactate dehydrogenase, and caused histopathological alterations, including degeneration, fatty vacuolation, myolysis, and atrophy of myocardial fibers. Malondialdehyde (MDA), nitric oxide (NO), nuclear factor-kappaB (NF-κB) p65, tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1β were increased, whereas reduced glutathione (GSH), superoxide dismutase (SOD), and catalase were decreased in ISO-administered rats. UMB effectively ameliorated myocardial injury, alleviated cardiac function markers, MDA, NO, NF-κB p65, and the inflammatory mediators, and enhanced cellular antioxidants. Bax, caspase-3, and 8-OHdG were decreased, and Bcl-2 was increased in ISO-administered rats treated with UMB. In addition, UMB upregulated nuclear factor-erythroid factor 2-related factor 2 (Nrf2) and heme oxygenase (HO)-1 in the heart of ISO-administered rats. In conclusion, UMB can protect the myocardium from oxidative injury, inflammatory response, and cell death induced by ISO by upregulating Nrf2/HO-1 signaling and antioxidants.

Dietary modulation of large extracellular vesicles: the good and the bad for human health

Extracellular vesicles (EVs) encompassing nanovesicles derived from the endosome system and generated by plasmatic membrane shedding are of increasing interest in view of their ability to sustain cell-to-cell communication and the possibility that they could be used as surrogate biomarkers of healthy and unhealthy trajectories. Nutritional strategies have been developed to preserve health, and the impact of these strategies on circulating EVs is arousing growing interest. Data available from published studies are now sufficient for a first integration to better understand the role of EVs in the relationship between diet and health. Thus, this review focuses on human intervention studies investigating the impact of diet or its components on circulating EVs. Because of analytical bias, only large EVs have been assessed so far. The analysis highlights that poor-quality diets with elevated fat and sugar content increase levels of circulating large EVs, and these can be partly counteracted by healthy food or some food micronutrients and bioactive compounds. However, knowledge of the content and the biological functions of these diet-induced EVs is still missing. It is important to address these aspects in new research in order to state if EVs are mediators of the effects of diet on health.

Bitter Gourd Honey Ameliorates Hepatic and Renal Diabetic Complications on Type 2 Diabetes Rat Models by Antioxidant, Anti-Inflammatory, and Anti-Apoptotic Mechanisms

Honey has several pharmacological effects, including anti-diabetic activity. However, the effectiveness of bitter gourd honey (BGH) in the treatment of diabetes mellitus (DM) is unknown. The aim of this study was to determine the antioxidant, anti-inflammatory, and anti-apoptotic properties of BGH on the kidney and liver of a streptozotocin-induced diabetes rat model.

METHODS

A single dose (nicotinamide 110 mg/kg, streptozotocin (STZ) 55 mg/kg, intraperitoneal (i.p.)) was used to induce DM in male rats. For 28 days, normal or diabetic rats were administered 1 g/kg/day and 2 g/kg/day of BGH orally. After the treatment, blood, liver, and kidney samples were collected and analysed for biochemical, histological, and molecular parameters. In addition, liquid chromatography-mass spectrometry (LC-MS) was used to identify the major bioactive components in BGH.

RESULTS

The administration of BGH to diabetic rats resulted in significant reductions in alanine transaminase (ALT),aspartate aminotransferase (AST), creatinine, and urea levels. Diabetic rats treated with BGH showed lesser pathophysiological alterations in the liver and kidney as compared to non-treated control rats. BGH-treated diabetic rats exhibited reduced levels of oxidative stress (MDA levels), inflammatory (MYD88, NFKB, p-NFKB, IKKβ), and apoptotic (caspase-3) markers, as well as higher levels of antioxidant enzymes (SOD, CAT, and GPx) in the liver and kidney. BGH contains many bioactive compounds that may have antioxidative stress, anti-inflammatory, and anti-apoptotic effects.

CONCLUSION

BGH protected the liver and kidney in diabetic rats by reducing oxidative stress, inflammation, and apoptosis-induced damage. As a result, BGH can be used as a potential therapy to ameliorate diabetic complications.

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.

Extracellular Vesicles as Natural Delivery Carriers Regulate Oxidative Stress Under Pathological Conditions

Extracellular vesicles are cellular secretory particles that can be used as natural drug delivery carriers. They have successfully delivered drugs including chemotherapeutics, proteins, and genes to treat various diseases. Oxidative stress is an abnormal physiological phenomenon, and it is associated with nearly all diseases. In this short review, we summarize the regulation of EVs on oxidative stress. There are direct effects and indirect effects on the regulation of oxidative stress through EVs. On the one hand, they can deliver antioxidant substances or oxides to recipient cells, directly relieving or aggravating oxidative stress. On the other hand, regulate factors of oxidative stress-related signaling pathways can be delivered to recipient cells by the mediation of EVs, realizing the indirect regulation of oxidative stress. To the best of our knowledge, however, only endogenous drugs have been delivered by EVs to regulate oxidative stress till now. And the heterogeneity of EVs may complicate the regulation of oxidative stress. Therefore, this short review aims to draw more attention to the EVs-based regulation of oxidative stress, and we hope excellent EVs-based delivery carriers that can deliver exogenous drugs to regulate oxidative stress can be exploited.

Sitagliptin Reduces Endothelial Dysfunction and Apoptosis Induced by High-Fat Diet and Palmitate in Thoracic Aortas and Endothelial Cells via ROS-ER Stress-CHOP Pathway

Macrovascular disease is tightly associated with obesity-induced metabolic syndrome. Sitagliptin (SIT), an orally stable selective inhibitor of Dipeptidyl peptidase-4 (DPP-4), has protective effects on endothelium. However, the mechanisms enabling SIT to exhibit resistance to diet-induced obesity (DIO) related with reactive oxygen species (ROS) and endoplasmic reticulum (ER) stress in the aorta and endothelial cells have not been reported yet. Therefore, the present study was conducted to determine if SIT exerts protective role in the thoracic aortas isolated from the high-fat diet (HFD)-treated rats and palmitate (PA)-treated endothelial cells by alleviating ROS and ER stress. Male Sprague Dawley rats were randomly divided into standard chow diet (SCD), HFD and HFD plus sitagliptin administration (HFD + SIT) groups. The rats of latter two groups were given HFD fodder for 12 weeks, then the HFD + SIT rats were treated with SIT (10 mg/kg/d) by intragastric administration for another 8 weeks. The body mass, vascular tension, serum oxidative stress indices and inflammatory parameters, pathological changes, protein expression of endothelial nitric oxide synthase (eNOS), the genes associated with ER stress and apoptosis in the thoracic aorta were measured. Furthermore, cell proliferation, ROS and the protein expression associated with ER stress (especially CHOP) and apoptosis were assessed in human umbilical vein endothelial cells (HUVECs) incubated with SIT and PA. Compared to the SCD rats, the HFD rats had higher serum lipid levels, decreased vascular tension, increased inflammation, oxidative and ER stress, and apoptosis of endothelial cells. PA promoted ROS generation, ER stress and apoptosis, inhibited cell proliferation in HUVECs. SIT treatment obviously ameliorated apoptosis via alleviating ROS and ER stress in the thoracic aortas isolated from HFD-fed rats and PA-treated HUVECs. The results suggest that SIT improved endothelial function via promoting cell proliferation and alleviating ROS-ER stress-CHOP pathway both in vivo and in vitro.

Endothelial Dysfunction and Inflammatory Markers of Vascular Disease

Vascular diseases are the main reason for morbidity and mortality worldwide. As we know, the earlier phase of vascular diseases is endothelial dysfunction in humans, the endothelial tissues play an important role in inflammation, coagulation, and angiogenesis, via organizing ligand-receptor associations and the various mediators' secretion. We can use many inflammatory non-invasive tests (flowmediated dilatation, epicedial fat thickness, carotid-intima media thickness, arterial stiffness and anklebrachial index) for assessing the endothelial function. In addition, many biomarkers (ischemia modified albumin, pentraxin-3, E-selectin, angiopoietin, endothelial cell specific molecule 1, asymmetrical dimethylarginine, von Willebrand factor, endothelial microparticles and endothelial progenitor cells) can be used to evaluate endothelial dysfunction. We have focused on the relationship between endothelial dysfunction and inflammatory markers of vascular disease in this review.

Endothelial Extracellular Vesicles: From Keepers of Health to Messengers of Disease

Endothelium has a rich vesicular network that allows the exchange of macromolecules between blood and parenchymal cells. This feature of endothelial cells, along with their polarized secretory machinery, makes them the second major contributor, after platelets, to the particulate secretome in circulation. Extracellular vesicles (EVs) produced by the endothelial cells mirror the remarkable molecular heterogeneity of their parent cells. Cargo molecules carried by EVs were shown to contribute to the physiological functions of endothelium and may support the plasticity and adaptation of endothelial cells in a paracrine manner. Endothelium-derived vesicles can also contribute to the pathogenesis of cardiovascular disease or can serve as prognostic or diagnostic biomarkers. Finally, endothelium-derived EVs can be used as therapeutic tools to target endothelium for drug delivery or target stromal cells via the endothelial cells. In this review we revisit the recent evidence on the heterogeneity and plasticity of endothelial cells and their EVs. We discuss the role of endothelial EVs in the maintenance of vascular homeostasis along with their contributions to endothelial adaptation and dysfunction. Finally, we evaluate the potential of endothelial EVs as disease biomarkers and their leverage as therapeutic tools.

High-density lipoprotein's vascular protective functions in metabolic and cardiovascular disease - could extracellular vesicles be at play?

High-density lipoprotein (HDL) is a circulating complex of lipids and proteins known primarily for its role in reverse cholesterol transport and consequent protection from atheroma. In spite of this, therapies aimed at increasing HDL concentration do not reduce the risk of cardiovascular disease (CVD), and as such focus has shifted towards other HDL functions protective of vascular health - including vasodilatory, anti-inflammatory, antioxidant and anti-thrombotic actions. It has been demonstrated that in disease states such as CVD and conditions of insulin resistance such as Type 2 diabetes mellitus (T2DM), HDL function is impaired owing to changes in the abundance and function of HDL-associated lipids and proteins, resulting in reduced vascular protection. However, the gold standard density ultracentrifugation technique used in the isolation of HDL also co-isolates extracellular vesicles (EVs). EVs are ubiquitous cell-derived particles with lipid bilayers that carry a number of lipids, proteins and DNA/RNA/miRNAs involved in cell-to-cell communication. EVs transfer their bioactive load through interaction with cell surface receptors, membrane fusion and endocytic pathways, and have been implicated in both cardiovascular and metabolic diseases - both as protective and pathogenic mediators. Given that studies using density ultracentrifugation to isolate HDL also co-isolate EVs, biological effects attributed to HDL may be confounded by EVs. We hypothesise that some of HDL's vascular protective functions in cardiovascular and metabolic disease may be mediated by EVs. Elucidating the contribution of EVs to HDL functions will provide better understanding of vascular protection and function in conditions of insulin resistance and potentially provide novel therapeutic targets for such diseases.

Oridonin interferes with simple steatosis of liver cells by regulating autophagy

Oridonin has significant liver-protective effects, but its effect on liver steatosis has not been reported. We investigated the effects of oridonin on liver steatosis by cell cultures. The optimal experimental concentration of oridonin was determined through cytotoxicity experiments. A simple steatosis liver cell model was induced using free fatty acids (FFA). After adding oridonin to the FFA-induced cell model for 24 h, the lipid droplets and triglyceride (TG) content in the cells were measured by Oil Red O staining and TG kits. The expressions of autophagy-related markers (cyclin dependent kinases inhibitor 1a (p21), Beclin-1, microtubule-associated protein light chain 3 (LC3)-I and LC3-II, protein kinase B (AKT), phosphorylated-AKT (p-AKT), AMP-activated protein kinase (AMPK), and phosphorylated-AMPK (p-AMPK)) were detected by Western blot. Based on the results, the cell model was further treated by autophagy inhibitor 3-methyladenine (3-MA) to determine the degree of steatosis and the expressions of autophagy-related factors. Oridonin at a concentration higher than 10 μmol/L caused cytotoxicity to the cells. Adding 10 μmol/L oridonin to the FFA-induced cell model effectively reduced lipid droplets and TG content in the cells. Oridonin up-regulated p21, Beclin-1 and LC3-II expressions, but down-regulated those of p62 and LC3-I. Also, oridonin increased the ratios of LC3-II/LC3-I and p-AMPK/AMPK, but reduced that of p-AKT/AKT. With the addition of 3-MA, the effect of oridonin on reducing steatosis was partially reversed, and the autophagy was inhibited. This study found that oridonin can activate autophagy, thereby preventing simple steatosis of liver cells.

Galangin attenuates diabetic cardiomyopathy through modulating oxidative stress, inflammation and apoptosis in rats

Cardiovascular complications are the leading cause of morbidity in diabetes. Oxidative stress and inflammation are implicated in the development and progression of diabetic cardiomyopathy (DCM). This study explored the cardioprotective effect of galangin (Gal), a natural flavonoid with radical-scavenging and anti-inflammatory activities, in diabetic rats. An experimental diabetic rat model was achieved by a single injection of 50 mg/kg streptozotocin. Gal (15 mg/kg) was administered daily for six weeks and the samples were then collected. Diabetic rats exhibited hyperglycemia, increased glycosylated hemoglobin, triglycerides and cholesterol levels and reduced serum insulin. Serum troponin I, CK-MB and LDH were increased in diabetic rats. Furthermore, hearts of diabetic rats were characterized by elevated malondialdehyde, protein carbonyl, NF-κB p65, TNF-α, IL-1β, iNOS, IL-6, Bax, caspase-3 and 8-Oxo-dG, and decreased superoxide dismutase, catalase, reduced GSH, and Bcl-2. Gal ameliorated hyperglycemia, dyslipidemia, and heart function markers, and prevented histopathological alterations in diabetic rats. In addition, Gal attenuated cardiac oxidative injury, inflammation and apoptosis, and boosted antioxidant defenses. In conclusion, Gal has a protective effect on cardiomyopathy by attenuating hyperglycemia, dyslipidemia, oxidative stress and inflammation in diabetic rats.

Metabolomic approach to characterize the metabolic phenotypes and varied response to ouabain of diffuse large B-cell lymphoma cells

Germinal center B-cell-like (GCB) and activated B-cell-like (ABC) subtype diffuse large B-cell lymphoma (DLBCL) showed differential prognosis. Our results suggested that ouabain induced stronger inhibition of growth in Su-DHL4 (GCB), and it triggered obvious apoptosis in Su-DHL4 rather than in OCI-Ly3 (ABC). Two subtype cell lines also showed distinct metabolic phenotypes involving remarkable enrichment of Ribulose-5-Phosphate, hypoxanthine, and guanine in Su-DHL4 cells. Ouabain disturbed metabolic patterns of both cell lines dose-dependently manifested inhibition of free fatty acids and amino acids metabolism, among which ornithine was further identified as potential quantitative marker. Up-regulated Ribulose-5-Phosphate and NADPH/NADP⁺ level, SOD1, and CAT expression by ouabain enabled OCI-Ly3 cells to resist ROS, while enhanced hypoxanthine and guanine oxidation promoting ROS generation by ouabain, and lowered capacity of scavenging ROS indicated by lowered SOD1 and CAT expression and NADPH/NADP⁺ levels in Su-DHL4 cells made it more vulnerable to apoptosis through caspase 7 pathway.

Aqueous Cichorium intybus L. seed extract may protect against acute palmitate-induced impairment in cultured human umbilical vein endothelial cells by adjusting the Akt/eNOS pathway, ROS: NO ratio and ET-1 concentration

Background

Endothelial dysfunction, which is a vascular response to oxidative stress and inflammation, involves a cascade of downstream events that lead to decreased synthesis of insulin-mediated vasodilator nitric oxide (NO) and increased production of vasoconstrictor protein endothelin-1 (ET-1). NO, and ET-1 production by endothelial cells is regulated by phosphatidylinositol 3-kinase (PI3K)-Akt-eNOS axis and mitogen-activated protein kinase (MAPK) axis of the insulin signaling pathway, respectively.

Methods

After treating the human umbilical vein endothelial cells (HUVECs) with either palmitate complexed with bovine serum albumin (BSA) (abbreviated as PA) or the aqueous Cichorium intybus L. (chicory) seed extract (chicory seed extract, abbreviated as CSE) alone, and simultaneously together (PA + CSE), for 3, 12, and 24 h, we evaluated the capacity of CSE to reestablish the PA-induced imbalance between PI3K/Akt/eNOS and MAPK signaling pathways. The level of oxidative stress was determined by fluorimeter. Insulin-induced levels of NO and ET-1 were measured by Griess and ELISA methods, respectively. Western blotting was used to determine the extent of Akt and eNOS phosphorylation.

Results

Contrary to PA that caused an increase in the reactive oxygen species (ROS) levels and attenuated NO production, CSE readjusted the NO/ROS ratio within 12 h. CSE improved the metabolic arm of the insulin signaling pathway by up-regulating the insulin-stimulated phospho-eNOS Ser1177/total eNOS and phospho-Akt Thr308/total Akt ratios and decreased ET-1 levels.

Conclusions

CSE ameliorated the PA-induced endothelial dysfunction not only by its anti-ROS property but also by selectively enhancing the protective arm and diminishing the injurious arm of insulin signaling pathways.

Edaravone and Acetovanillone Upregulate Nrf2 and PI3K/Akt/mTOR Signaling and Prevent Cyclophosphamide Cardiotoxicity in Rats

Introduction

Cyclophosphamide (CP) causes redox imbalance and its use is associated with marked cardiotoxicity that limits its clinical applications. The present study investigated the protective effects of acetovanillone (AV) and edaravone (ED) against CP-induced oxidative stress and cardiac damage, emphasizing the role of PI3K/Akt/mTOR and Nrf2 signaling.

Materials and Methods

Rats received either AV (100 mg/kg) or ED (20 mg/kg) orally for 10 days and CP (200 mg/kg) on day 7. At day 11, the rats were sacrificed, and samples were collected for analysis.

Results

AV and ED ameliorated serum troponin I, CK-MB, LDH, AST and ALP, and prevented cardiac histological alterations in CP-intoxicated rats. Both treatments decreased cardiac lipid peroxidation and enhanced GSH, SOD and cytoglobin in CP-induced rats. AV and ED downregulated Keap1, whereas increased the expression of PI3K, Akt, mTOR and Nrf2 in the heart of rats received CP. Additionally, the binding modes of AV and ED to Keap1 were pinpointed in silico using molecular docking simulations.

Conclusion

AV and ED prevent CP cardiotoxicity by attenuating oxidative stress and tissue injury, and modulating cytoglobin, and PI3K/Akt/mTOR and Keap1/Nrf2 signaling. Therefore, AV and ED may represent promising agents that can prevent cardiac injury in patients receiving CP.

Calcium Ionophore-Induced Extracellular Vesicles Mediate Cytoprotection against Simulated Ischemia/Reperfusion Injury in Cardiomyocyte-Derived Cell Lines by Inducing Heme Oxygenase 1

Cardioprotection against ischemia/reperfusion injury is still an unmet clinical need. The transient activation of Toll-like receptors (TLRs) has been implicated in cardioprotection, which may be achieved by treatment with blood-derived extracellular vesicles (EVs). However, since the isolation of EVs from blood takes considerable effort, the aim of our study was to establish a cellular model from which cardioprotective EVs can be isolated in a well-reproducible manner. EV release was induced in HEK293 cells with calcium ionophore A23187. EVs were characterized and cytoprotection was assessed in H9c2 and AC16 cell lines. Cardioprotection afforded by EVs and its mechanism were investigated after 16 h simulated ischemia and 2 h reperfusion. The induction of HEK293 cells by calcium ionophore resulted in the release of heterogenous populations of EVs. In H9c2 and AC16 cells, stressEVs induced the downstream signaling of TLR4 and heme oxygenase 1 (HO-1) expression in H9c2 cells. StressEVs decreased necrosis due to simulated ischemia/reperfusion injury in H9c2 and AC16 cells, which was independent of TLR4 induction, but not that of HO-1. Calcium ionophore-induced EVs exert cytoprotection by inducing HO-1 in a TLR4-independent manner.

Targeting Transcription Factor Nrf2 (Nuclear Factor Erythroid 2-Related Factor 2) for the Intervention of Vascular Cognitive Impairment and Dementia

Vascular cognitive impairment and dementia (VCID) is an age-related, mild to severe mental disability due to a broad panel of cerebrovascular disorders. Its pathobiology involves neurovascular dysfunction, blood-brain barrier disruption, white matter damage, microRNAs, oxidative stress, neuroinflammation, and gut microbiota alterations, etc. Nrf2 (Nuclear factor erythroid 2-related factor 2) is the master regulator of redox status and controls the transcription of a panel of antioxidative and anti-inflammatory genes. By interacting with NF-κB (nuclear factor-κB), Nrf2 also fine-tunes the cellular oxidative and inflammatory balance. Aging is associated with Nrf2 dysfunction, and increasing evidence has proved the role of Nrf2 in mitigating the VCID process. Based on VCID pathobiologies and Nrf2 studies from VCID and other brain diseases, we point out several hypothetical Nrf2 targets for VCID management, including restoration of endothelial function and neurovascular coupling, preservation of blood-brain barrier integrity, reduction of amyloidopathy, promoting white matter integrity, and mitigating oxidative stress and neuroinflammation. Collectively, the Nrf2 pathway could be a promising direction for future VCID research. Targeting Nrf2 would shed light on VCID managing strategies.

Overexpression of fibroblast growth factor-21 (FGF-21) protects mesenchymal stem cells against caspase-dependent apoptosis induced by oxidative stress and inflammation

The clinical application of stem cells offers great promise as a potential avenue for therapeutic use in neurodegenerative diseases. However, cell loss after transplantation remains a major challenge, which currently plagues the field. On the basis of our previous findings that fibroblast growth factor 21 (FGF-21) protected neurons from glutamate excitotoxicity and that upregulation of FGF-21 in a rat model of ischemic stroke was associated with neuroprotection, we proposed that overexpression of FGF-21 protects bone marrow-derived mesenchymal stem cells (MSCs) from apoptosis. To test this hypothesis, we examined whether the detrimental effects of apoptosis can be mitigated by the transgenic overexpression of FGF-21 in MSCs. FGF-21 was transduced into MSCs by lentivirus and its overexpression was confirmed by quantitative polymerase chain reaction. Moreover, FGF-21 overexpression did not stimulate the expression of other FGF family members, suggesting it does not activate a positive feedback system. The effects of hydrogen peroxide (H2 O2 ), tumor necrosis factor-α (TNF-α), and staurosporine, known inducers of apoptosis, were evaluated in FGF-21 overexpressing MSCs and mCherry control MSCs. Caspases 3 and 7 activity was markedly and dose-dependently increased by all three stimuli in mCherry MSCs. FGF-21 overexpression robustly suppressed caspase activation induced by H2 O2 and TNF-α, but not staurosporine. Moreover, the assessment of apoptotic morphological changes confirmed the protective effects of FGF-21 overexpression. Taken together, these results provide compelling evidence that FGF-21 plays a crucial role in protecting MSCs from apoptosis induced by oxidative stress and inflammation and merits further investigation as a strategy for enhancing the therapeutic efficacy of stem cell-based therapies.

Circulating microparticles released during dyslipidemia may exert deleterious effects on blood vessels and endothelial function

AIMS

To compare the bioactivity of circulating microparticles (MPs) isolated from dyslipidemic Psammomys obesus (P. obesus) fed a high-energy diet (HED) with those released from healthy P. obesus fed a normal diet (ND).

METHODS

Vascular reactivity of aortic rings was evaluated by myography, after 24 h incubation in the absence or in the presence of circulating MPs isolated, by differential centrifugations, from the plasma of animals subjected to HED (MPs_HED) or ND (MPs_ND) for 12 weeks. Human umbilical vein endothelial cells (HUVECs) were treated for 24 h with MPs_HED or MPs_ND animals and subjected to immunofluorescence staining of caveolin-1 (cav-1), intercellular adhesion molecule-1 (ICAM-1), endothelial nitric oxide synthase (eNOS), F-actin and reactive oxygen species (ROS) detection.

RESULTS

The HED exerted a distinctly pronounced hyperlipidemic effect marked by plasmatic increase of total cholesterol, low-density lipoprotein-cholesterol (LDL-C) and triglyceride (TG). Both MPs_ND and MPs_HED induced a significant reduction of maximal relaxation induced by acetylcholine (ACh). Interestingly, MPs_HED significantly decreased eNOS expression up to ~25% and increased ROS production up to ~75% on in vitro treated HUVECs. Moreover, in HUVECs, MPs_HED significantly decreased cav-1 expression up to ~50% whereas significant increase of ICAM-1 expression by about 2-fold approximately was observed.

CONCLUSION

Our experimental study demonstrated the dual role of MPs on vascular function by modulating endothelial cell function. Furthermore, MPs may be considered as vectors of a bioactive information contributing to inflammation and vascular damage.

Umbelliferone Inhibits Spermatogenic Defects and Testicular Injury in Lead-Intoxicated Rats by Suppressing Oxidative Stress and Inflammation, and Improving Nrf2/HO-1 Signaling

INTRODUCTION

Lead (Pb) is an environmental toxic metal that threatens human health. Umbelliferone (UMB) is a coumarin with known medicinal and protective properties against cytotoxicity. This study explored the ameliorative effect of UMB against Pb-induced testicular toxicity in rats, focusing on steroidogenesis, oxidative stress and inflammation.

MATERIALS AND METHODS

Rats received lead acetate (50 mg/kg) and UMB (25, 50 or 100 mg/kg) via oral gavage for 4 weeks.

RESULTS

Pb-intoxicated rats exhibited testicular tissue injury and decreased serum levels of LH, FSH and testosterone. The count, viability, motility and normal morphology of the sperms were decreased accompanied with downregulated steroidogenesis markers in Pb-induced group. UMB prevented testicular injury, increased serum levels of LH, FSH and testosterone, upregulated steroidogenesis markers and improved the semen quality. In addition, UMB attenuated oxidative stress and oxidative DNA damage, downregulated the expression of pro-inflammatory mediators and Bax, boosted antioxidant defenses and Bcl-2, and upregulated Nrf2/HO-1 signaling in Pb-intoxicated rats.

CONCLUSION

UMB prevents Pb-induced testicular injury by suppressing oxidative damage, inflammation and cell death, and boosting antioxidant defenses, Nrf2/HO-1 signaling and pituitary-gonadal axis. Thus, UMB may represent a protective and cost-effective agent against Pb testicular toxicity, pending further investigations to elucidate other underlying mechanisms.

Liquid Biopsies: Microvesicles in Cardiovascular Disease

Significance: Circulating microvesicles (cMV) are small (0.1-1 μm) phospholipid-rich blebs released by almost all cell types, and their release increases with cell activation and injury, thus reflecting the state of the cell from which they are originated. Microvesicles (MV) are found in the bloodstream, and they affect the phenotype of recipient cells, after local or systemic circulation, by intercellular transfer of their molecular content. Recent Advances: Several studies suggest the use of cell-specific MV subpopulations as predictive biomarkers for cardiovascular diseases (CVDs) at different stages and degrees of severity. In this review, we describe the state of the art of cMV as noninvasive surrogate biomarkers of vascular injury and dysfunction correlated with poor clinical outcomes in CVD. Critical Issues: Despite the growing body of evidence supporting the importance of cMV as hallmarks of CVD and their utility as biomarkers of CVD, the specific roles of each phenotype of cMV in CVD burden and prognosis still remain to be elucidated and validated in large cohorts. In addition, the development of standardized and reproducible techniques is required to be used as biomarkers for disease progression in the clinical setting. Future Directions: A multipanel approach with specific cMV phenotypes, added to current biomarkers and scores, will undoubtedly provide unique prognostic information to stratify patients for appropriate therapy on the basis of their risk of atherothrombotic disease and will open a new research area as therapeutic targets for CVD. MV will add to the implementation of precision medicine by helping the cellular and molecular characterization of CVD patients.

Curcumin and Selenium Prevent Lipopolysaccharide/Diclofenac-Induced Liver Injury by Suppressing Inflammation and Oxidative Stress

Diclofenac (DCL), an anti-inflammatory drug used to reduce pain and inflammation, ranks in the top causes of drug-induced liver injury. The inflammatory stress induced by inflammagens is implicated in DCL-induced liver injury. Curcumin (CUR) and selenium (Se) possess anti-inflammatory effects; therefore, this study evaluated their protective potential against lipopolysaccharide (LPS)/DCL-induced liver injury. Rats received CUR and/or Se for 7 days followed by a single intravenous administration of LPS 2 h before a single injection of DCL and two other doses of CUR and/or Se 2 and 8 h after DCL. Administration of nontoxic doses of LPS and DCL resulted in liver damage evidenced by the significantly elevated liver function markers in serum. LPS/DCL-induced liver injury was confirmed by histological alterations, increased lipid peroxidation and nitric oxide, and diminished glutathione and superoxide dismutase. CUR and/or Se prevented liver injury, histological alterations, and oxidative stress and boosted antioxidant defenses in LPS/DCL-induced rats. In addition, CUR and/or Se reduced serum C-reactive protein, liver pro-inflammatory cytokines, and the expression of TLR4, NF-κB, JNK, and p38, and upregulated heme oxygenase-1 (HO-1). In conclusion, CUR and/or Se mitigated LPS/DCL-induced liver injury in rats by suppressing TLR4 signaling, inflammation, and oxidative stress and boosting HO-1 and other antioxidants. Therefore, CUR and Se can hinder the progression and severity of liver injury during acute inflammatory episodes.

Concentration of circulating microparticles: a new biomarker of acute heart failure after cardiac surgery with cardiopulmonary bypass

Acute heart failure (AHF) is a severe complication after cardiac surgery with cardiopulmonary bypass (CPB). Although some AHF biomarkers have been used in clinic, they have limitations when applied in the prediction and diagnosis of AHF after cardiac surgery with CPB, and there are still no effective and specific biomarkers. We and other researchers have shown that circulating microparticles (MPs) increased in a variety of cardiovascular diseases. However, whether the concentration of circulating MPs could be a new biomarker for AHF after cardiac surgery remains unknown. Here, 90 patients undergoing cardiac surgery with CPB and 45 healthy subjects were enrolled. Patients were assigned into AHF (n=14) or non-AHF (n=76) group according to the diagnosis criteria of AHF. The concentrations of circulating MPs were determined before, as well as 12 h and 3 days after operation with nanoparticle tracking analysis technique. MPs concentrations in patients before surgery were significantly higher than those of healthy subjects. Plasma levels of MPs were significantly elevated at 12 h after surgery in patients with AHF, but not in those without AHF, and the circulating MPs concentrations at 12 h after surgery were higher in AHF group compared with non-AHF group. Logistic regression analysis indicated that MPs concentration at postoperative 12 h was an independent risk factor for AHF. The area under receiver operating characteristic curve for MPs concentration at postoperative 12 h was 0.81 and the best cut-off value is 5.20×10⁸ particles mL^-1 with a sensitivity of 93% and a specificity of 10%. These data suggested that the concentration of circulating MPs might be a new biomarker for the occurrence of AHF after cardiac surgery with CPB.

Sevoflurane preconditioning inhibits cardiomyocyte injury induced by oxygen‑glucose deprivation by modulating TXNIP

The thioredoxin interaction protein (TXNIP) has been reported to be closely related to cell oxidative stress, apoptosis and inflammation. TXNIP is involved in the regulation of oxidative stress in lung and renal injury. However, it is unclear as to whether it participates in the protective effects of sevoflurane preconditioning in cardiomyocyte injury caused by oxidative stress in ischemia. In the present study, H9c2 cardiomyocytes were cultured with 0, 1.5, 2, 3.5, 5 or 6% sevoflurane for 3 h, followed by exposure to oxygen and glucose deprivation. The results demonstrated that oxygen and glucose deprivation induced an increase in TXNIP expression, lactate dehydrogenase (LDH) release, caspase‑3 activity, reactive oxygen species and malondialdehyde production. Preconditioning of the H9c2 cells with 3.5% sevoflurane suppressed TXNIP expression, LDH leakage, caspase‑3 activity, reactive oxygen species and malondialdehyde production, and it promoted cell viability. TXNIP overexpression reversed the effects of 3.5% sevoflurane preconditioning on caspase‑3 activity, reactive oxygen production and cell viability. Furthermore, TXNIP modulated p27 expression via PKB (protein kinase B/AKT) phosphorylation following preconditioning with 3.5% sevoflurane, and oxygen and glucose deprivation. On the whole these findings indicated that sevoflurane preconditioning protected the H9c2 cells against injury induced by oxygen and glucose deprivation by modulating TXNIP, AKT activation and p27 signaling.

Chicoric acid prevents methotrexate hepatotoxicity via attenuation of oxidative stress and inflammation and up-regulation of PPARγ and Nrf2/HO-1 signaling

Chicoric acid (CA) is a natural antioxidant with promising hepatoprotective activity. We investigated the potential of CA to prevent methotrexate (MTX) hepatotoxicity, pointing to the role of Nrf2/HO-1 signaling and PPARγ. Rats received CA for 15 days and were then injected with MTX at day 16. Blood and tissue samples were collected for analysis at day 19. CA ameliorated liver function markers and mitigated histological alterations in MTX-induced rats. Pre-treatment with CA suppressed reactive oxygen species and lipid peroxidation and enhanced antioxidants in MTX-induced rats. Moreover, CA upregulated hepatic Nrf2, HO-1, NQO-1, and PPARγ, and attenuated inflammation. Consequently, CA inhibited apoptosis by increasing Bcl-2 expression and suppressing Bax, cytochrome c, and caspase-3 in MTX-administered rats. In conclusion, CA prevented oxidative stress, inflammation, and liver injury induced by MTX by activating Nrf2 /HO-1 signaling and PPARγ.

Identification of a novel regulatory pathway for PPARα by RNA-seq characterization of the endothelial cell lipid peroxidative injury transcriptome

Endothelial dysfunction caused by endothelial cell injuries is the initiating factor for atherosclerosis (AS), and lipid peroxidative injury is one of a dominant factor for AS pathogenesis. Using RNA-seq, we compared changes in transcriptome expression before and after endothelial cell injury, and found 311 differentially expressed genes (DEGs), of which 258 genes were upregulated and 53 genes were downregulated. The protein–protein interactions (PPIs) between the genes were analysed using the STRING database, and a PPI network of DEGs was constructed. The relationship distributions among these PPIs were analysed by performing network node statistics. We found that in the top 20 DEGs with high connected protein nodes in the PPI network, 16 were upregulated and 4 were downregulated. Gene ontology (GO) functional enrichment analysis and KEGG pathway enrichment analysis on the DEGs were also performed. By comparing the upregulated expressed genes with high connected protein nodes in the PPI network to those related to endothelial cell lipid damage and repair in the GO analysis, we identified seven genes (NOX4, PPARA, CCL2, PDGFB, IL8, VWF, CD36) and verified their expression levels by real-time polymerase chain reaction. The protein interactions between the seven genes were then analysed using the STRING database. The results predicted that CCL2 interacts with NOX4, PPARα, PDGFβ and VWF individually. Thus, we examined the protein expression levels of CCL2, NOX4, PPARα, PDGFβ and VWF, and found that the expression levels of all proteins were significantly upregulated after the lipid peroxidative injury, with CCL2 and PPARα exhibiting the highest expression levels. Therefore, we investigated the interregulatory relationship between CCL2 and PPARα and their roles in the repair of endothelial cell injury. With the help of gene overexpression and knockdown techniques, we discovered that PPARα promotes the repair of endothelial cell injury by upregulating CCL2 expression in human umbilical vein endothelial cells but that CCL2 cannot regulate PPARα expression. Therefore, we believe that PPARα participates in the repair of endothelial cell lipid peroxidative injury through regulating the expression of CCL2.

The role of microvesicles and its active molecules in regulating cellular biology

Cell‐derived microvesicles are membrane vesicles produced by the outward budding of the plasma membrane and released by almost all types of cells. These have been considered as another mechanism of intercellular communication, because they carry active molecules, such as proteins, lipids and nucleic acids. Furthermore, these are present in circulating fluids, such as blood and urine, and are closely correlated to the progression of pathophysiological conditions in many diseases. Recent studies have revealed that microvesicles have a dual effect of damage and protection of receptor cells. However, the nature of the active molecules involved in this effect remains unclear. The present study mainly emphasized the mechanism of microvesicles and the active molecules mediating the different biological effects of receptor cells by affecting autophagy, apoptosis and inflammation pathways. The effective ways of blocking microvesicles and its active molecules in mediating cell damage when microvesicles exert harmful effects were also discussed.

Formononetin Upregulates Nrf2/HO-1 Signaling and Prevents Oxidative Stress, Inflammation, and Kidney Injury in Methotrexate-Induced Rats

Acute kidney injury (AKI) is a serious complication of methotrexate (MTX). This study explored the protective effect of the isoflavone formononetin (FN) against MTX nephrotoxicity with an emphasis on oxidative stress, inflammation, and nuclear factor (erythroid-derived 2)-like 2/heme oxygenase 1 (Nrf2/HO-1) signaling. Rats received FN (10, 20, and 40 mg/kg) for 10 days and a single dose of MTX on day 7. MTX induced kidney injury was characterized by increased serum creatinine and urea, kidney injury molecule-1 (Kim-1), and several histological alterations. FN ameliorated kidney function and inhibited the renal tissue injury induced by MTX. Reactive oxygen species (ROS), lipid peroxidation (LPO), nitric oxide, and 8-Oxo-2′-deoxyguanosine were increased, whereas antioxidant defenses were diminished in the kidney of MTX-administered rats. In addition, MTX upregulated renal iNOS, COX-2, TNF-α, IL-1β, Bax, caspase-9, and caspase-3, and decreased Bcl-2, Nrf2, and HO-1. FN suppressed oxidative stress, LPO, DNA damage, iNOS, COX-2, proinflammatory cytokines, and apoptosis, and boosted Bcl-2, antioxidants, and Nrf2/HO-1 signaling in MTX-administered rats. In conclusion, FN prevents MTX-induced AKI by activating Nrf2/HO-1 signaling and attenuates oxidative damage and inflammation. Thus, FN may represent an effective adjuvant that can prevent MTX nephrotoxicity, pending further mechanistic studies.

Galangin Activates Nrf2 Signaling and Attenuates Oxidative Damage, Inflammation, and Apoptosis in a Rat Model of Cyclophosphamide-Induced Hepatotoxicity

Cyclophosphamide (CP) is a widely used chemotherapeutic agent; however, its clinical application is limited because of its multi-organ toxicity. Galangin (Gal) is a bioactive flavonoid with promising biological activities. This study investigated the hepatoprotective effect of Gal in CP-induced rats. Rats received Gal (15, 30 and 60 mg/kg/day) for 15 days followed by a single dose of CP at day 16. Cyclophosphamide triggered liver injury characterized by elevated serum transaminases, alkaline phosphatase (ALP) and lactate dehydrogenase (LDH), and histopathological manifestations. Increased hepatic reactive oxygen species, malondialdehyde, nitric oxide, and oxidative DNA damage along with declined glutathione and antioxidant enzymes were demonstrated in CP-administered rats. CP provoked hepatic nuclear factor-kappaB (NF-κB) phosphorylation and increased mRNA abundance of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), and tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) both expression and serum levels. Gal prevented CP-induced liver injury, boosted antioxidants and suppressed oxidative stress, DNA damage, NF-κB phosphorylation and pro-inflammatory mediators. Gal diminished Bax and caspase-3, and increased B-cell lymphoma-2 (Bcl-2) in liver of CP-administered rats. In addition, Gal increased peroxisome proliferator-activated receptor gamma (PPARγ) expression and activated hepatic nuclear factor erythroid 2-related factor 2 (Nrf2) signaling showed by the increase in Nrf2, NAD(P)H: quinone acceptor oxidoreductase-1 (NQO-1) and heme oxygenase 1 (HO-1) in CP-administered rats. These findings suggest that Gal prevents CP hepatotoxicity through activation of Nrf2/HO-1 signaling and attenuation of oxidative damage, inflammation and cell death. Therefore, Gal might represent a promising adjuvant therapy to prevent hepatotoxicity in patients on CP treatment.

Endothelial progenitor cell-derived exosomes facilitate vascular endothelial cell repair through shuttling miR-21-5p to modulate Thrombospondin-1 expression

Background: Our previous studies observed that administration of exosomes from endothelial progenitor cells (EPC) facilitated vascular repair in the rat model of balloon injury. However, the molecular events underlying this process remain elusive. Here, we aim to interrogate the key miRNAs within EPC-derived exosomes (EPC-exosomes) responsible for the activation of endothelial cell (EC) repair. Methods: The efficacy of EPC-exosomes in re-endothelialization was examined by Evans Blue dye and histological examination in the rat model of balloon-induced carotid artery injury. The effects of EPC-exosomes on human vascular EC (HUVEC) were also studied by evaluating the effects on growth, migratory and tube formation. To dissect the underlying mechanism, RNA-sequencing assays were performed to determine miRNA abundance in exosomes and mRNA profiles in exosome-treated HUVECs. Meanwhile, in vitro loss of function assays identified an exosomal miRNA and its target gene in EC, which engaged in EPC-exosomes-induced EC repair. Results: Administration of EPC-exosomes potentiated re-endothelialization in the early phase after endothelial damage in the rat carotid artery. The uptake of exogenous EPC-exosomes intensified HUVEC in proliferation rate, migration and tube-forming ability. Integrative analyses of miRNA-mRNA interactions revealed that miR-21-5p was highly enriched in EPC-exosomes and specifically suppressed the expression of an angiogenesis inhibitor Thrombospondin-1 (THBS1) in the recipient EC. The following functional studies demonstrated a fundamental role of miR-21-5p in the pro-angiogenic activities of EPC-exosomes. Conclusions: The present work highlights a critical event for the regulation of EC behavior by EPC-exosomes, which EPC-exosomes may deliver miR-21-5p and inhibit THBS1 expression to promote EC repair.

Ameliorative Effect of Beta vulgaris Root Extract on Chlorpyrifos-Induced Oxidative Stress, Inflammation and Liver Injury in Rats

Exposure to organophosphorus insecticides causes several health problems to animals and humans. Red beetroot (RBR) is rich in antioxidant ingredients and possesses a promising hepatoprotective activity. This study evaluated the potential of RBR extract to prevent chlorpyrifos (CPF)-induced liver injury, with an emphasis on oxidative stress, inflammation and apoptosis. Rats received 10 mg/kg CPF and were treated with 300 mg/kg RBR extract for 28 days. CPF caused liver injury evidenced by elevated serum levels of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and bilirubin, along with several histological alterations. Hepatic lipid peroxidation (LPO) and nitric oxide (NO) levels, as well as inducible nitric oxide synthase (iNOS) and pro-inflammatory cytokines were increased in CPF-intoxicated rats. RBR prevented CPF-induced histological alterations, and ameliorated liver function, LPO, NO, iNOS and pro-inflammatory cytokines. RBR boosted glutathione and antioxidant enzymes, and increased Nrf2 expression. In addition, RBR diminished Bax and caspase-3, and increased Bcl-2 expression. In conclusion, RBR prevented CPF-induced liver injury via attenuation of oxidative stress, inflammation and apoptosis. RBR enhanced antioxidant defenses, suggesting that it could be used as a potential therapeutic intervention to minimize CPF hepatotoxicity.

Microvesicles: ROS scavengers and ROS producers

This review analyzes the relationship between microvesicles and reactive oxygen species (ROS). This relationship is bidirectional; on the one hand, the number and content of microvesicles produced by the cells are affected by oxidative stress conditions; on the other hand, microvesicles can directly and/or indirectly modify the ROS content in the extra- as well as the intracellular compartments. In this regard, microvesicles contain a pro-oxidant or antioxidant machinery that may produce or scavenge ROS: direct effect. This mechanism is especially suitable for eliminating ROS in the extracellular compartment. Endothelial microvesicles, in particular, contain a specific and well-developed antioxidant machinery. On the other hand, the molecules included in microvesicles can modify (activate or inhibit) ROS metabolism in their target cells: indirect effect. This can be achieved by the incorporation into the cells of ROS metabolic enzymes included in the microvesicles, or by the regulation of signaling pathways involved in ROS metabolism. Proteins, as well as miRNAs, are involved in this last effect.

Extracellular vesicles in cardiovascular homeostasis and disease

PURPOSE OF REVIEW

Extracellular vesicles have emerged as one of the most important means through which cells interact with each other and the extracellular environment, but extracellular vesicle research remains challenging due to their small size, limited amount of material required for traditional molecular biology assays and inconsistency in the methods of their isolation. The advent of new technologies and standards in the field, however, have led to increased mechanistic insight into extracellular vesicle function. Herein, the latest studies on the role of extracellular vesicles in cardiovascular physiology and disease are discussed.

RECENT FINDINGS

Extracellular vesicles help control cardiovascular homeostasis and remodelling by mediating communication between cells and directing alterations in the extracellular matrix to respond to changes in the environment. The message carried from the parent cell to extracellular space can be intended for both local (within the same tissue) and distal (downstream of blood flow) targets. Pathological cargo loaded within extracellular vesicles could further result in various diseases. On the contrary, new studies indicate that injection of extracellular vesicles obtained from cultured cells into diseased tissues can promote restoration of normal tissue function.

SUMMARY

Extracellular vesicles are an integral part of cell and tissue function, and harnessing the properties inherent to extracellular vesicles may provide a therapeutic strategy to promote tissue regeneration.

Endothelial Microparticles in Uremia: Biomarkers and Potential Therapeutic Targets

Endothelial microparticles (EMPs) are vesicles derived from cell membranes, which contain outsourced phosphatidylserine and express adhesion molecules, such as cadherin, intercellular cell adhesion molecule-1 (ICAM-1), E-selectin, and integrins. EMPs are expressed under physiological conditions and continue circulating in the plasma. However, in pathologic conditions their levels increase, and they assume a pro-inflammatory and pro-coagulant role via interactions with monocytes; these effects are related to the development of atherosclerosis. Chronic kidney dysfunction (CKD) characterizes this dysfunctional scenario through the accumulation of uremic solutes in the circulating plasma, whose toxicity is related to the development of cardiovascular diseases. Therefore, this review aims to discuss the formation of EMPs and their biological effects in the uremic environment. Data from previous research demonstrate that uremic toxins are closely associated with the activation of inflammatory biomarkers, cardiovascular dysfunction processes, and the release of EMPs. The impact of a decrease in circulating EMPs in clinical studies has not yet been evaluated. Thus, whether MPs are biochemical markers and/or therapeutic targets has yet to be established.

RS, Yuan SY. Role of Neutrophil Extracellular Traps and Vesicles in Regulating Vascular Endothelial Permeability

The microvascular endothelium serves as the major barrier that controls the transport of blood constituents across the vessel wall. Barrier leakage occurs during infection or sterile inflammation, allowing plasma fluid and cells to extravasate and accumulate in surrounding tissues, an important pathology underlying a variety of infectious diseases and immune disorders. The leak process is triggered and regulated by bidirectional communications between circulating cells and vascular cells at the blood-vessel interface. While the molecular mechanisms underlying this complex process remain incompletely understood, emerging evidence supports the roles of neutrophil-endothelium interaction and neutrophil-derived products, including neutrophil extracellular traps and vesicles, in the pathogenesis of vascular barrier injury. In this review, we summarize the current knowledge on neutrophil-induced changes in endothelial barrier structures, with a detailed presentation of recently characterized molecular pathways involved in the production and effects of neutrophil extracellular traps and extracellular vesicles. Additionally, we discuss the therapeutic implications of altering neutrophil interactions with the endothelial barrier in treating inflammatory diseases.

Microvesicles from cerebrospinal fluid of patients with Alzheimer's disease display reduced concentrations of tau and APP protein

Microvesicles are small membranous particles generated during cellular activation or stress. The analysis of the content and the surface of microvesicles allow conclusions about the cells they are originating from and the underlying pathology. Therefore, CSF microvesicles have been suggested to be promising targets to monitor the (etio)pathology of neurodegenerative diseases. Microvesicles in the CSF of 15 patients with Alzheimer’s disease and 15 controls were analyzed by flow cytometry regarding the levels of CD3, CD4, CD45, CD64, BACE1, Aβ, APP and tau. The results were replicated in a second cohort comprising 14 patients with Alzheimer’s disease and 9 controls. The levels of tau and APP were reduced in microvesicles of Alzheimer’s disease patients. A significant change was neither observed in the number of microvesicles nor in the expression of the other antigens. Tau and APP in microvesicles separated patients with Alzheimer’s disease from controls with an AUC of 0.84 and 0.89 respectively. We conclude that tau and APP in CSF microvesicles are promising biomarkers which could directly provide information about the Alzheimer pathology on a cellular level.

Sumoylation of PPARγ contributes to vascular endothelium insulin resistance through stabilizing the PPARγ-NcoR complex

Sumoylation of peroxisome proliferator-activated receptor γ (PPARγ) affects its stabilization, sublocalization, and transcriptional activity. However, it remains largely unknown whether PPARγ sumoylation inhibits the transactivation effect, leading to endothelium insulin resistance (IR). To test this possibility, human umbilical vascular endothelial cells (HUVECs) with a 90% confluence were randomly allocated to two batches. One batch was first pretreated with or without vitamin E for 24 hr and the other infected with adenoviruses containing either PIAS1-shRNA (protein inhibitor of activated STAT1-short hairpin RNA) or scramble shRNA. Cells were suffered from high glucose and palmitic acid (PA) exposure for further 48 hr. The levels of PPARγ, p-IKK, IKK, and NcoR (nuclear corepressors) were measured by western blot analysis. The interaction of IKK and PIAS1, as well as the PPARγ sumoylation, were examined by coimmunoprecipitation. The results showed that the exposure of high glucose and PA induced reactive oxygen species (ROS) production and IKK activation in HUVECs, promoting the interaction of IKK and PIAS1 and the sumoylation of PPARγ. However, vitamin E and PIAS1-shRNA partially decreased ROS production and IKK activation induced by high glucose and PA exposure. These data indicate that ROS-IKK-PIAS1 pathway mediates PPARγ sumoylation, leading to endothelium IR via stabilizing PPARγ-NcoR complex. These findings benefit understanding of regulatory networks of insulin signaling, which might provide a potential target to prevent and cure IR-related diseases.