Endothelial microvesicles in hypoxic hypoxia diseases

Targeted therapy using engineered extracellular vesicles: principles and strategies for membrane modification

Extracellular vesicles (EVs) are 30-150 nm membrane-bound vesicles naturally secreted by cells and play important roles in intercellular communication by delivering regulatory molecules such as proteins, lipids, nucleic acids and metabolites to recipient cells. As natural nano-carriers, EVs possess desirable properties such as high biocompatibility, biological barrier permeability, low toxicity, and low immunogenicity, making them potential therapeutic delivery vehicles. EVs derived from specific cells have inherent targeting capacity towards specific cell types, which is yet not satisfactory enough for targeted therapy development and needs to be improved. Surface modifications endow EVs with targeting abilities, significantly improving their therapeutic efficiency. Herein, we first briefly introduce the biogenesis, composition, uptake and function of EVs, and review the cargo loading approaches for EVs. Then, we summarize the recent advances in surface engineering strategies of EVs, focusing on the applications of engineered EVs for targeted therapy. Altogether, EVs hold great promise for targeted delivery of various cargos, and targeted modifications show promising effects on multiple diseases.

Long COVID: pathophysiological factors and abnormalities of coagulation

Acute COVID-19 infection is followed by prolonged symptoms in approximately one in ten cases: known as Long COVID. The disease affects ~65 million individuals worldwide. Many pathophysiological processes appear to underlie Long COVID, including viral factors (persistence, reactivation, and bacteriophagic action of SARS CoV-2); host factors (chronic inflammation, metabolic and endocrine dysregulation, immune dysregulation, and autoimmunity); and downstream impacts (tissue damage from the initial infection, tissue hypoxia, host dysbiosis, and autonomic nervous system dysfunction). These mechanisms culminate in the long-term persistence of the disorder characterized by a thrombotic endothelialitis, endothelial inflammation, hyperactivated platelets, and fibrinaloid microclots. These abnormalities of blood vessels and coagulation affect every organ system and represent a unifying pathway for the various symptoms of Long COVID.

Intravenous iron supplementation in heart failure patients induces temporary endothelial dysfunction with release of endothelial microvesicles

Background

Intravenous iron supplementation is an established therapy for patients with heart failure (HF) and concomitant iron deficiency reducing the risk of HF hospitalization. However, concerns persist regarding potential adverse vascular effects, since iron may induce oxidative stress, inflammation, and apoptosis of endothelial cells. To assess endothelial health following ferric carboxymaltose (FCM) administration, we analyzed the profile of circulating endothelial microvesicles (EMVs) and endothelial progenitor cells (EPCs) in a cohort of 23 HF patients using flow cytometry.

Results

Compared to healthy subjects, baseline levels of CD31+/CD41- EMVs were higher and EMVs featured a more apoptotic phenotype in HF patients. Following FCM administration, EMV levels showed a rapid but transient increase and displayed an altered phenotype profile with dominant augmentation of EMVs expressing inducible markers CD62E and CD54, indicating endothelial inflammatory activation and injury. Levels of circulating vasoregenerative CD45lowCD34+KDR+ EPCs were lower in HF patients and FCM application resulted in an early decrease of EPCs followed by substantial mobilization into the circulation after one week. Levels of EMVs and EPCs returned to baseline values within two and four weeks, respectively. HF patients with additional chronic kidney disease showed an elevated EMV/EPC ratio and diminished EPC mobilization, suggesting impaired vascular repair capacity. Providing a mechanistic link, in vitro experiments with cultured endothelial cells revealed that FCM dose-dependently promotes endothelial apoptosis, increases expression of adhesion molecules and CXCL12, and triggers generation of EMVs.

Conclusion

Intravenous iron supplementation with FCM in HF patients induces a biphasic response with initial increased release of CD62E+ and CD54+ enriched EMVs and subsequent mobilization of EPCs, indicating endothelial dysfunction upon FCM and suggesting consecutive engagement of a defense program aimed to reconstitute vascular health.

Circulating endothelial microvesicles and their carried miR-125a-5p: potential biomarkers for ischaemic stroke

Background

Endothelial microvesicles (EMVs) are closely associated with the status of endothelial cells (ECs). Our earlier study has shown that EMVs could exert protective roles in ECs by transferring their carried miR-125a-5p. However, whether circulating EMVs and their carried miR-125a-5p can be used as biomarkers in ischaemic stroke (IS) are remain unknown.

Methods

We recruited 72 subjects with IS, 60 subjects with high stroke risk and 56 age-matched controls. The circulating EMVs and their carried miR-125a-5p (EMV-miR-125a-5p) levels were detected. We used microRNA (miR) array to study expression changes of miRs in plasma EMVs samples of three IS patients and three matched healthy controls. Transient middle cerebral artery occlusion (tMCAO) was used to establish IS mouse model.

Results

EMVs level was obviously elevated in IS patients, with the highest level in acute stage, and was positively related to carotid plaque, carotid intima–media thickness (IMT), National Institutes of Health Stroke Scale (NIHSS), infarct volume. On the contrary, we observed that EMV-miR-125a-5p level was obviously reduced in IS, with the lowest level in acute stage, and was negatively correlated with carotid plaque, IMT, NIHSS scores, infarct volume. EMVs and EMV-miR-125a-5p levels were closely related with large artery atherosclerosis subgroup. Importantly, EMVs and EMV-miR-125a-5p levels could serve as independent risk factors, and receiver operating characteristic curve achieved an area under curve (AUC) of 0.720 and 0.832 for IS, respectively, and elevated to 0.881 after their combination. In IS mouse model, control EMVs or n-EMVs administration could decrease the infarct volume and neurological deficit score, while increase the cerebral blood flow of IS mice compared with vehicle group, while IS EMVs or oxygen and glucose deprivation (OGD)-EMVs administration aggravated the tMCAO induced ischaemic injury. In addition, we observed that OGD EMVmiR-125a-5p could partially ameliorate the OGD EMVs induced brain injury after IS.

Conclusions

These findings demonstrate that circulating EMVs and EMV-miR-125a-5p are closely related with the occurrence, progress, subtypes and severity of IS, and they can serve as innovative biomarkers and therapeutic targets for IS, especially when they are combined.

Long COVID: The Nature of Thrombotic Sequelae Determines the Necessity of Early Anticoagulation

Many discharged COVID-19 patients affected by sequelae experience reduced quality of life leading to an increased burden on the healthcare system, their families and society at large. Possible pathophysiological mechanisms of long COVID include: persistent viral replication, chronic hypoxia and inflammation. Ongoing vascular endothelial damage promotes platelet adhesion and coagulation, resulting in the impairment of various organ functions. Meanwhile, thrombosis will further aggravate vasculitis contributing to further deterioration. Thus, long COVID is essentially a thrombotic sequela. Unfortunately, there is currently no effective treatment for long COVID. This article summarizes the evidence for coagulation abnormalities in long COVID, with a focus on the pathophysiological mechanisms of thrombosis. Extracellular vesicles (EVs) released by various types of cells can carry SARS-CoV-2 through the circulation and attack distant tissues and organs. Furthermore, EVs express tissue factor and phosphatidylserine (PS) which aggravate thrombosis. Given the persistence of the virus, chronic inflammation and endothelial damage are inevitable. Pulmonary structural changes such as hypertension, embolism and fibrosis are common in long COVID. The resulting impaired lung function and chronic hypoxia again aggravates vascular inflammation and coagulation abnormalities. In this article, we also summarize recent research on antithrombotic therapy in COVID-19. There is increasing evidence that early anticoagulation can be effective in improving outcomes. In fact, persistent systemic vascular inflammation and dysfunction caused by thrombosis are key factors driving various complications of long COVID. Early prophylactic anticoagulation can prevent the release of or remove procoagulant substances, thereby protecting the vascular endothelium from damage, reducing thrombotic sequelae, and improving quality of life for long-COVID patients.

Exploring New Kingdoms: The Role of Extracellular Vesicles in Oxi-Inflamm-Aging Related to Cardiorenal Syndrome

The incidence of age associated chronic diseases has increased in recent years. Although several diverse causes produce these phenomena, abundant evidence shows that oxidative stress plays a central role. In recent years, numerous studies have focused on elucidating the role of oxidative stress in the development and progression of both aging and chronic diseases, opening the door to the discovery of new underlying mechanisms and signaling pathways. Among them, senolytics and senomorphics, and extracellular vesicles offer new therapeutic strategies to slow the development of aging and its associated chronic diseases by decreasing oxidative stress. In this review, we aim to discuss the role of extracellular vesicles in human cardiorenal syndrome development and their possible role as biomarkers, targets, or vehicles of drugs to treat this syndrome.

LncRNA MALAT1 inhibits hypoxia/reoxygenation-induced human umbilical vein endothelial cell injury via targeting the microRNA-320a/RAC1 axis

Angiogenesis is believed to protect against hypoxia/reoxygenation (H/R)-induced cell injury. MALAT1 and microRNA-320a (miR-320a) are involved in cancer angiogenesis. To investigate the function of the MALAT1/miR-320a axis in H/R-induced cell injury, human umbilical vein endothelial cell (HUVEC) angiogenesis was detected using the Cell Counting Kit-8 (CCK-8), Transwell migration, cell adhesion and tube formation assays. The expression of MALAT1 and miR-320a was revealed by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The direct binding relationship between miR-320a and MALAT1 was detected by RNA immunoprecipitation (RIP) and dual luciferase reporter assays. The data indicated that H/R induces angiogenesis injury and that the expression of MALAT1 was augmented in H/R-stimulated HUVECs. Overexpression of MALAT1 alleviated H/R-stimulated HUVEC dysfunction, whereas silencing of MALAT1 exerted the opposite effects. MALAT1 also reduced miR-320a levels in HUVECs. Overexpression of miR-320a repressed the function of MALAT1 on H/R-stimulated HUVECs, whereas inhibition of miR-320a exerted the opposite effect. Additionally, miR-320a inhibition alleviated H/R-stimulated HUVEC injury via RAC1. Taken together, this investigation concluded that MALAT1 represses H/R-stimulated HUVEC injury by targeting the miR-320a/RAC1 axis.

Microvesicles in plasma reflect coronary flow reserve in patients with cardiovascular disease

High levels of microvesicles (MVs), a type of extracellular vesicles, are detected in several pathological conditions. We investigated the connection between coronary flow reserve (CFR), a prognostic clinical parameter that reflects blood flow in the heart, with levels of MVs and their cargo, from plasma of patients with cardiovascular disease. The PROFLOW study consists of 220 patients with prior myocardial infarction and measured CFR with transthoracic echocardiography. The patients were divided into high and low CFR groups. Plasma MVs were captured with acoustic trapping. Platelet- and endothelial-derived MVs were measured with flow cytometry, and vesicle lysates were analyzed with proteomic panels against cardiovascular biomarkers. Flow cytometry was further applied to identify cellular origin of biomarkers. Our data show a negative correlation between MV concentration and CFR values. Platelet and endothelial MV levels were significantly increased in plasma from the low CFR group. CFR negatively correlates with the levels of several proteomic biomarkers, and the low CFR group exhibited higher concentrations of these proteins in MVs. Focused analysis of one of the MV proteins, B cell activating factor (BAFF), revealed platelet and not leukocyte origin and release upon proinflammatory stimulus. Higher levels of MVs carrying an elevated concentration of proatherogenic proteins circulate in plasma in patients with low CFR, a marker of vascular dysfunction, reduced blood flow, and poor prognosis. Our findings demonstrate a potential clinical value of MVs as biomarkers and possible therapeutic targets against endothelial deterioration.

NEW & NOTEWORTHY We investigated how microvesicles (MVs) from patients with cardiovascular diseases are related to coronary flow reserve (CFR), a clinical parameter reflecting blood flow in the heart. Our results show a negative relationship between CFR and levels of platelet and endothelial MVs. The pattern of MV-enriched cardiovascular biomarkers differs between patients with high and low CFR. Our findings suggest a potential clinical value of MVs as biomarkers of reduced blood flow and proatherogenic status, additional to CFR.

Reduced Intellectual Ability in Offspring Born from Preeclamptic Mothers: A Prospective Cohort Study

Background

Severe preeclampsia may affect placental development, and high homocysteine (Hcy) levels are linked to intellectual disability. However, the correlation between perinatal Hcy levels and intellectual ability remains unknown in severe preeclampsia-affected offspring.

Objective

We aimed to investigate the intellectual ability in offspring born from preeclamptic mothers and examine the role of prenatal Hcy in the prediction of intellectual disability in preschool-aged offspring.

Methods

The IQ scores were compared between 101 children born to mothers with severe preeclampsia and 202 offsprings born to normotensive mothers. Maternal Hcy levels within 7 days prior to delivery and postnatal cord blood Hcy were measured. The associations of Hcy with IQ scores were evaluated, and the optimal cut-off values for predicting intellectual disability in the offspring were estimated.

Results

The children born to mothers with severe preeclampsia had a greater postnatal cord blood Hcy than those born from normotensive mothers (P < 0.001), and the mothers with severe preeclampsia presented a higher prenatal Hcy (P < 0.001). The children born to mothers with severe preeclampsia had significantly lower IQ scores than those born from normotensive mothers, and a higher Hcy was associated with a lower IQ in preeclampsia-affected offspring. The prevalence of intellectual disability was 2.86 times higher in severe preeclampsia-affected offspring than in children born from normotensive mothers, and the prevalence of low IQ was greater in children born to mothers with severe preeclampsia than in those from normotensive mothers. ROC curve analysis showed that both maternal and cord blood Hcy were predictors of intellectual disability, and the optimal cut-off for predicting intellectual disability was 17.7 and 9.75 μmol/L for maternal and cord blood Hcy.

Conclusion

Perinatal exposure to severe preeclampsia has an adverse effect on postnatal intellectual development, and high maternal and cord blood Hcy may contribute to this association.

Bilberry Supplementation after Myocardial Infarction Decreases Microvesicles in Blood and Affects Endothelial Vesiculation

SCOPE

Diet rich in bilberries is considered cardioprotective, but the mechanisms of action are poorly understood. Cardiovascular disease is characterized by increased proatherogenic status and high levels of circulating microvesicles (MVs). In an open-label study patients with myocardial infarction receive an 8 week dietary supplementation with bilberry extract (BE). The effect of BE on patient MV levels and its influence on endothelial vesiculation in vitro is investigated.

METHODS AND RESULTS

MVs are captured with acoustic trapping and platelet-derived MVs (PMVs), as well as endothelial-derived MVs (EMVs) are quantified with flow cytometry. The in vitro effect of BE on endothelial extracellular vesicle (EV) release is examined using endothelial cells and calcein staining. The mechanisms of BE influence on vesiculation pathways are studied by Western blot and qRT-PCR. Supplementation with BE decreased both PMVs and EMVs. Furthermore, BE reduced endothelial EV release, Akt phosphorylation, and vesiculation-related gene transcription. It also protects the cells from P2X7 -induced EV release and increase in vesiculation-related gene expression.

CONCLUSION

BE supplementation improves the MV profile in patient blood and reduces endothelial vesiculation through several molecular mechanisms related to the P2X7 receptor. The findings provide new insight into the cardioprotective effects of bilberries.

Clinical Characteristics and Outcomes of Patients with Severe COVID-19 and Chronic Obstructive Pulmonary Disease (COPD)

BACKGROUND The rapid worldwide spread of the coronavirus disease 2019 (COVID-19) epidemic has placed patients with pre-existing conditions at risk of severe morbidity and mortality. The present study investigated the clinical characteristics and outcomes of patients with severe COVID-19 and chronic obstructive pulmonary disease (COPD). MATERIAL AND METHODS This study enrolled 336 consecutive patients with confirmed severe COVID-19, including 28 diagnosed with COPD, from January 20, 2020, to April 1, 2020. Demographic data, symptoms, laboratory values, comorbidities, and clinical results were measured and compared in survivors and non-survivors. RESULTS Patients with severe COVID-19 and COPD were older than those without COPD. The proportions of men, of patients admitted to the intensive care unit (ICU) and of those requiring invasive ventilation were significantly higher in patients with than without COPD. Leukocyte and neutrophil counts, as well as the concentrations of NT-proBNP, hemoglobin, D-dimer, hsCRP, ferritin, IL-2R, TNF-alpha and procalcitonin were higher, whereas lymphocyte and monocyte counts were lower, in patients with than without COPD. Of the 28 patients with COPD, 22 (78.6%) died, a rate significantly higher than in patients without COPD (36.0%). A comparison of surviving and non-surviving patients with severe COVID-19 and COPD showed that those who died had a longer history of COPD, more fatigue, and a higher ICU occupancy rate, but a shorter average hospital stay, than those who survived. CONCLUSIONS COPD increases the risks of death and negative outcomes in patients with severe COVID-19.

Plasma endothelial microvesicles and their carrying miRNA-155 serve as biomarkers for ischemic stroke

Endothelial microvesicles (EMVs) could reflect the status of endothelial cells (ECs) which are involved in the pathogenesis of ischemic stroke (IS). MiR-155 could regulate EC functions. However, their roles in IS remain unclear. This study aimed to investigate the levels of plasma EMVs and EMVs carrying miRNA-155 (EMVs-miR-155) in IS patients to explore their potential roles as biomarkers. Ninety-three IS patients and 70 controls were recruited in this study. The levels of circulating EMVs and EMVs-miR-155 were detected by fluorescence nanoparticle tracking analysis and quantitative real-time PCR, respectively. The correlations between level of EMVs/EMVs-miR-155 and the onset time, severity, infarct volume, and subtypes of IS were analyzed. The severity and infarct volume were assessed by NIHSS and magnetic resonance imaging, respectively. Multivariate logistic regression analysis was used to investigate the risk factors of IS. The ROC curve and area under ROC curve (AUC) of EMVs and EMVs-miR-155 were determined. The levels of plasma EMVs and EMVs-miR-155 were increased significantly in acute and subacute stages of IS and remained unchanged in chronic stage, and were positively related to the infarct volume and NIHSS scores and were associated with large artery atherosclerosis and cardioembolism subtypes defined by Trial of Org 10 172 in acute stroke treatment (TOAST) classification. Multivariate logistic regression analysis demonstrated that plasma EMVs and EMVs-miR-155 were significant and independent risk factors of IS and their AUC were 0.778 and 0.851, respectively, and increased to 0.892 after combination. Our study suggests that plasma EMVs and EMVs-miR-155 are promising biomarkers for IS. The diagnostic value of EMVs-miR-155 is higher and their combination is the best.

Vesicular Transport of Encapsulated microRNA between Glial and Neuronal Cells

Exosomes (EXs) and extracellular microvesicles (EMVs) represent a diverse assortment of plasma membrane-derived nanovesicles, 30–1000 nm in diameter, released by all cell lineages of the central nervous system (CNS). They are examples of a very active and dynamic form of extracellular communication and the conveyance of biological information transfer essential to maintain homeostatic neurological functions and contain complex molecular cargoes representative of the cytoplasm of their cells of origin. These molecular cargoes include various mixtures of proteins, lipids, proteolipids, cytokines, chemokines, carbohydrates, microRNAs (miRNA) and messenger RNAs (mRNA) and other components, including end-stage neurotoxic and pathogenic metabolic products, such as amyloid beta (Aβ) peptides. Brain microglia, for example, respond to both acute CNS injuries and degenerative diseases with complex reactions via the induction of a pro-inflammatory phenotype, and secrete EXs and EMVs enriched in selective pathogenic microRNAs (miRNAs) such as miRNA-34a, miRNA-125b, miRNA-146a, miRNA-155, and others that are known to promote neuro-inflammation, induce complement activation, disrupt innate–immune signaling and deregulate the expression of neuron-specific phosphoproteins involved in neurotropism and synaptic signaling. This communication will review our current understanding of the trafficking of miRNA-containing EXs and EMVs from astrocytes and “activated pro-inflammatory” microglia to target neurons in neurodegenerative diseases with an emphasis on Alzheimer’s disease wherever possible.

Novel gene regulatory networks identified in response to nitro-conjugated linoleic acid in human endothelial cells

Endothelial cell (EC) dysfunction is a crucial initiation event in the development of atherosclerosis and is associated with diabetes mellitus, hypertension, and heart failure. Both digestive and oxidative inflammatory conditions lead to the endogenous formation of nitrated derivatives of unsaturated fatty acids (FAs) upon generation of the proximal nitrating species nitrogen dioxide (·NO2) by nitric oxide (·NO) and nitrite-dependent reactions. Nitro-FAs (NO2-FAs) such as nitro-oleic acid (NO2-OA) and nitro-linoleic acid (NO2-LA) potently inhibit inflammation and oxidative stress, regulate cellular functions, and maintain cardiovascular homeostasis. Recently, conjugated linoleic acid (CLA) was identified as the preferential FA substrate of nitration in vivo. However, the functions of nitro-CLA (NO2-CLA) in ECs remain to be explored. In the present study, a distinct transcriptome regulated by NO2-CLA was revealed in primary human coronary artery endothelial cells (HCAECs) through RNA sequencing. Differential gene expression and pathway enrichment analysis identified numerous regulatory networks including those related to the modulation of inflammation, oxidative stress, cell cycle, and hypoxic responses by NO2-CLA, suggesting a diverse impact of NO2-CLA and other electrophilic nitrated FAs on cellular processes. These findings extend the understanding of the protective actions of NO2-CLA in cardiovascular diseases and provide new insight into the underlying mechanisms that mediate the pleiotropic cellular responses to NO2-CLA.

Microvesicles as promising biological tools for diagnosis and therapy

INTRODUCTION

Shed by most cells, in response to a myriad of stimuli, extracellular vesicles (EVs) carry proteins, lipids, and various nucleic acids. EVs encompass diverse subpopulations differing for biogenesis and content. Among these, microvesicles (MVs) derived from plasma membrane, are key regulators of physiopathological cellular processes including cancer, inflammation and infection. This review is unique in that it focuses specifically on the MVs as a mediator of information transfer. In fact, few proteomic studies have rigorously distinguished MVs from exosomes. Areas covered: Aim of this review is to discuss the proteomic analyses of the MVs. Many studies have examined mixed populations containing both exosomes and MVs. We discuss MVs' role in cell-specific interactions. We also show their emerging roles in therapy and diagnosis. Expert commentary: We see MVs as therapeutic tools for potential use in precision medicine. They may also have potential for allowing the identification of new biomarkers. MVs represent an invaluable tool for studying the cell of origin, which they closely represent, but it is critical to build a repository with data from MVs to deepen our understanding of their molecular repertoire and biological functions.

Endothelial microvesicles in hypoxic hypoxia diseases

Hypoxic hypoxia, including abnormally low partial pressure of inhaled oxygen, external respiratory dysfunction-induced respiratory hypoxia and venous blood flow into the arterial blood, is characterized by decreased arterial oxygen partial pressure, resulting in tissue oxygen deficiency. The specific characteristics include reduced arterial oxygen partial pressure and oxygen content. Hypoxic hypoxia diseases (HHDs) have attracted increased attention due to their high morbidity and mortality and mounting evidence showing that hypoxia-induced oxidative stress, coagulation, inflammation and angiogenesis play extremely important roles in the physiological and pathological processes of HHDs-related vascular endothelial injury. Interestingly, endothelial microvesicles (EMVs), which can be induced by hypoxia, hypoxia-induced oxidative stress, coagulation and inflammation in HHDs, have emerged as key mediators of intercellular communication and cellular functions. EMVs shed from activated or apoptotic endothelial cells (ECs) reflect the degree of ECs damage, and elevated EMVs levels are present in several HHDs, including obstructive sleep apnoea syndrome and chronic obstructive pulmonary disease. Furthermore, EMVs have procoagulant, proinflammatory and angiogenic functions that affect the pathological processes of HHDs. This review summarizes the emerging roles of EMVs in the diagnosis, staging, treatment and clinical prognosis of HHDs.