Plasma Microvesicles Research Articles

Looking for miRNA from plasma microvesicles differentially expressed in prostate tumors and healthy men

Looking for miRNA from plasma microvesicles differentially expressed in prostate tumors and healthy men

Circulating Extracellular-Vesicle-Incorporated MicroRNAs as Potential Biomarkers for Ischemic Stroke in Patients With Cancer.

This study aimed to evaluate whether extracellular-vesicle-incorporated microRNAs (miRNAs) are potential biomarkers for cancer-related stroke. This cohort study compared patients with active cancer who had embolic stroke of unknown sources (cancer-stroke group) with patients with only cancer, patients with only stroke, and healthy individuals (control groups). The expression profiles of miRNAs encapsulated in plasma exosomes and microvesicles were evaluated using microarray and validated using quantitative real-time polymerase chain reaction. The XENO-QTM miRNA assay technology was used to determine the absolute copy numbers of individual miRNAs in an external validation cohort. This study recruited 220 patients, of which 45 had cancer-stroke, 76 were healthy controls, 39 were cancer controls, and 60 were stroke controls. Three miRNAs (miR-205-5p, miR-645, and miR-646) were specifically incorporated into microvesicles in patients with cancer-related stroke, cancer controls, and stroke controls. The area under the receiver operating characteristic curves of these three miRNAs were 0.7692-0.8510 for the differentiation of patients with cancer-stroke from cancer-controls and 0.8077-0.8846 for the differentiation of patients with cancer-stroke from stroke controls. The levels of several miRNAs were elevated in the plasma exosomes of patients with cancer, but were lower than those in plasma microvesicles. An in vivo study showed that systemic injection of miR-205-5p promoted the development of arterial thrombosis and elevation of D-dimer levels. Stroke due to cancer-related coagulopathy was associated with deregulated expression of miRNAs, particularly microvesicle-incorporated miR-205-5p, miR-645, and miR-646. Further prospective studies of extracellular-vesicle-incorporated miRNAs are required to confirm the diagnostic role of miRNAs in patients with stroke and to screen the roles of miRNAs in patients with cancer.

Bioprotective role of platelet-derived microvesicles in hypothermia: Insight into the differential characteristics of peripheral and splenic platelets

BackgroundMost platelets are present in peripheral blood, but some are stored in the spleen. Because the tissue environments of peripheral blood vessels and the spleen are quite distinct, the properties of platelets present in each may also differ. However, no studies have addressed this difference. We previously reported that hypothermia activates splenic platelets, but not peripheral blood platelets, whose biological significance remains unknown. In this study, we focused on platelet-derived microvesicles (PDMVs) and analyzed their biological significance connected to intrasplenic platelet activation during hypothermia. MethodsC57Bl/6 mice were placed in an environment of −20 °C, and their rectal temperature was decreased to 15 °C to model hypothermia. Platelets and skeletal muscle tissue were collected and analyzed for their interactions. ResultsTranscriptomic changes between splenic and peripheral platelets were greater in hypothermic mice than in normal mice. Electron microscopy and real-time RT-PCR analysis revealed that platelets activated in the spleen by hypothermia internalized transcripts, encoding tissue repairing proteins, into PDMVs and released them into the plasma. Plasma microvesicles from hypothermic mice promoted wound healing in the mouse myoblast cell line C2C12. Skeletal muscles in hypothermic mice were damaged but recovered within 24 h after rewarming. However, splenectomy delayed recovery from skeletal muscle injury after the mice were rewarmed. ConclusionsThese results indicate that PDMVs released from activated platelets in the spleen play an important role in the repair of skeletal muscle damaged by hypothermia.

Bioprotective Role of Platelet-Derived Microvesicles in Hypothermia: Insights from the Differential Characteristics of Peripheral and Splenic Platelets

While platelets play an important role in hemostasis and blood coagulation, they also contribute to tissue repair. Most platelets are present in peripheral blood, but some are stored in the spleen. Since tissue environments of peripheral blood vessels and the spleen are quite distinctive, the properties of the platelets present in each may also differ. However, no studies have addressed this difference.We have reported that accidental hypothermia activates splenic platelets, but not peripheral blood, whose biological significance is unknown. Accidental hypothermia is an involuntary drop in core body temperature to less than 35°C due to exposure to low environmental temperatures. Shivering, an involuntary small contraction of skeletal muscles throughout the body, is thought to be an automatic defense system against cold, in which skeletal muscles contract to increase heat production. Shivering occurs in muscles throughout the body, so when muscles are damaged by it, the tissue must be repaired by a mechanism that covers the entire body.Platelets, when activated, release microvesicles that encapsulate many bioactive substances. These microvesicles are called platelet-derived microvesicles (PDMV). It is generally believed that when cells take up extracellular vesicles, they are affected by the action of the encapsulated substances. Therefore, we hypothesized that PDMV released by platelet activation in the spleen at hypothermia may be involved in the regeneration of skeletal muscle throughout the body. C57Bl/6 mice were placed in an environment of -20°C and the rectal temperature was lowered to 15°C to model hypothermia. Platelets, PDMV, and skeletal muscle tissue were collected from these mice for analysis.Transcriptomic changes between splenic and peripheral platelets were greater in hypothermic mice than in normal mice. Pathway analysis of these Transcriptomic changes showed alterations related to Wnt signaling, cytoskeletal remodeling, and cell adhesion. Electron microscopy and real-time RT-PCR analysis revealed that platelets activated in the spleen by hypothermia internalize the transcripts involved in tissue repair, such as Wnt3a and Ctnnb1, into PDMV and release them into plasma. Plasma microvesicles from hypothermic mice promoted wound healing in the mouse myoblast cell line C2C12. Skeletal muscles of hypothermic mice were damaged but recovered within 24 hours after rewarming. However, splenectomy delayed recovery from skeletal muscle injury even after the mice were rewarmed.These results indicate that PDMV released from activated platelets in the spleen plays an important role in the repair of skeletal muscle damaged by shivering of hypothermia, suggesting a novel function of the spleen not previously known.

Abstract 15324: The Fontan Circulation Shows Decreased Cell Survival and Oxidative Damage

Introduction: Single ventricle congenital heart disease such as hypoplastic left heart syndrome (HLHS) with a Fontan circulation accounts for the largest group of children hospitalized with circulation failure, with an in-hospital mortality of 20-50%. We sought to (i) evaluate the mechanisms underlying circulation failure and (ii) identify novel therapeutic targets. Methods: Blood was collected from patients with HLHS s/p Fontan and from controls with normal cardiac anatomy and function (N=5/group). Plasma microvesicles (MV) were isolated and proteomics assessed using data independent acquisition mass spectroscopy. Dysregulated proteins with a fold change >1.5 or < -1.5, p<0.05 were evaluated using Ingenuity pathway analysis. Results: Age of Fontan patients vs. controls was 17.04±2 vs. 15.7±2.5, p=0.4; 20% were male in both groups. 60% of Fontan patients were in NYHA class II/III, 40% in NYHA class IV; 80% had Fontan-associated liver disease. Circulating MVs were released from cardiomyocytes, endothelial cells, and hepatocytes based on cell surface markers. Upregulated proteins (N=27) implicated cell death pathways (Solute carrier family 2, Angiotensinogen, CD14); while downregulated proteins (N=88) implicated impaired cell survival (tyrosine-protein kinase Yes, endothelial growth factors). MVs contained mitochondria and endoplasmic reticulum proteins implicating upregulation in reactive oxygen species signaling (catalase A, S100A8) and downregulation in antioxidant enzymes (GPX1, PRDX 5). Conclusion: Circulating MVs from patients with HLHS s/p Fontan are released from the heart, blood vessels, and liver providing a noninvasive signature of organ remodeling. The MV protein cargo implicates heightened cell death, oxidative damage and impaired cell survival, thereby providing insight into the mechanisms of Fontan associated circulation failure. Figure: Decreased Cell Survival and Oxidative Damage in the Fontan Circulation

МикроРНК miR-221 и miR-223 в микровезикулах плазмы крови - перспективные биомаркеры степени тяжести посттромбоэмболического синдрома

В работе представлены результаты исследования микроРНК miR-221 и miR-223 в микровезикулах плазмы крови у пациентов, перенесших тромбоэмболию легочной артерии, а также их взаимосвязь с показателями клинического анализа крови и тяжестью развившихся осложнений. The results of the study of microRNAs miR-221 and miR-223 in blood plasma microvesicles in patients with pulmonary embolism, as well as their relationship with clinical blood test parameters and the severity of complications, were presented.

SPOD2 Microvesicles as biomarkers for the screening of colorectal neoplasm

Abstract Background Colorectal cancer (CRC) is the second cause of cancer death worldwide. Screening for CRC by Faecal Immunochemical Test (FIT) aims to detect early cases before symptoms occur. Yet, the FIT has poor predictive value and low compliance rate. To address this, the role of circulating microvesicles as potential screening tool is a novel approach that warrants prioritised research. Methods In a two-gate diagnostic accuracy study, 35 patients with benign colorectal polyps (BCRP) (n=16) and colorectal cancer (CRC) (n=19) were compared to 17 age-matched healthy controls. Total annexin-V positive microvesicles and sub-populations positive for selected biomarkers relevant to bowel neoplasm were evaluated in patients’ plasma using flow cytometry. Results Total plasma microvesicles, and sub-populations positive for CD31, CD42a, CD31+/CD42a-, EPHB2, ICAM and LGR5 (component factor-1) were able to identify patients with BCRP and CRC with a receiver operator curve (AUC) accuracy of a 100% (95% CI: 100% to 100%) and 95% (95% CI: 88% to 100%) respectively. To identify patients with BCRP, a cut-off point value of component factor-1 ≥761 microvesicles/µL demonstrated a 100% sensitivity, specificity and negative predictive value (NPV) and a 93% positive predictive value (PPV). To identify patients with CRC, a cut-off value of component factor-1 ≥439 microvesicles/µL demonstrated a 100% sensitivity, specificity and NPV and a 65% PPV. CEA+ microvesicles sub-population were significantly (p<0.02) higher in CRC in comparison to BCRP. Conclusion Microvesicles as biomarkers for the early detection of CRC is a simple and effective tool that yields a potential breakthrough in clinical management.

Blood Cell-Derived Microvesicles in Hematological Diseases and beyond.

Microvesicles or ectosomes represent a major type of extracellular vesicles that are formed by outward budding of the plasma membrane. Typically, they are bigger than exosomes but smaller than apoptotic vesicles, although they may overlap with both in size and content. Their release by cells is a means to dispose redundant, damaged, or dangerous material; to repair membrane lesions; and, primarily, to mediate intercellular communication. By participating in these vital activities, microvesicles may impact a wide array of cell processes and, consequently, changes in their concentration or components have been associated with several pathologies. Of note, microvesicles released by leukocytes, red blood cells, and platelets, which constitute the vast majority of plasma microvesicles, change under a plethora of diseases affecting not only the hematological, but also the nervous, cardiovascular, and urinary systems, among others. In fact, there is evidence that microvesicles released by blood cells are significant contributors towards pathophysiological states, having inflammatory and/or coagulation and/or immunomodulatory arms, by either promoting or inhibiting the relative disease phenotypes. Consequently, even though microvesicles are typically considered to have adverse links with disease prognosis, progression, or outcomes, not infrequently, they exert protective roles in the affected cells. Based on these functional relations, microvesicles might represent promising disease biomarkers with diagnostic, monitoring, and therapeutic applications, equally to the more thoroughly studied exosomes. In the current review, we provide a summary of the features of microvesicles released by blood cells and their potential implication in hematological and non-hematological diseases.

Protective roles of seminal plasma exosomes and microvesicles during human sperm cryopreservation

Research questionDo seminal plasma microvesicles and exosomes, as two subtypes of extracellular vesicles, exert cryoprotective properties in sperm cryopreservation? DesignMicrovesicles and exosomes isolated from normozoospermic semen samples (n = 10) by serial ultracentrifugation were determined using scanning electron microscopy, dynamic light scattering and western blot analysis. The interactions between extracellular vesicles and spermatozoa were detected using Dil labelling. Purified spermatozoa from different normozoospermic samples (n = 25) were then treated individually with exosomes or microvesicles for 1 h and subsequently cryopreserved. The effects of extracellular vesicles during cryopreservation were investigated by determining post-thaw sperm motility, morphology, viability, reactive oxygen species (ROS) generation, lipid peroxidation, total antioxidant capacity (TAC), mitochondrial membrane potential (MMP), DNA integrity, and apoptosis rate. ResultsMicrovesicles and exosomes displayed a round-shape morphology, with about 70% of exosomes ranging from 43–144 nm, microvesicles ranging from 144.5–486 nm and both expressed tetraspanin markers. Fluorescence microscopy showed that exosomes and microvesicles absorbed mainly in the sperm head and less frequently in the neck and tail. The post-thawing results indicated that the diluent with exosomes or microvesicles had improved sperm motility (P = 0.007), morphology (P < 0.001) and viability (P < 0.001) compared with untreated samples. The ROS levels decreased significantly (P = 0.001), with a consequent decrease in DNA damage (P = 0.001). The TAC activity (P = 0.001) and MMP levels (P = 0.001) were also significantly improved; levels of malondialdehyde (MDA) (P = 0.62) and apoptosis rate (P = 1.000) remained unchanged. ConclusionSeminal plasma microvesicles and exosomes could protect spermatozoa from cryopreservation chilling injuries.

The role of microvesicles as biomarkers in the screening of colorectal neoplasm.

BackgroundColorectal cancer (CRC) is the second cause of cancer death worldwide. The role of circulating microvesicles as a screening tool is a novel, yet effective approach that warrants prioritised research.MethodsIn a two‐gate diagnostic accuracy study, 35 patients with benign colorectal polyps (BCRP) (n = 16) and colorectal cancer (CRC) (n = 19) were compared to 17 age‐matched healthy controls. Total annexin‐V positive microvesicles and sub‐populations positive for selected biomarkers relevant to bowel neoplasm were evaluated in patients' plasma using flow cytometry. Statistical methods including factor analysis utilising two component factors were performed to obtain optimal diagnostic accuracy of microvesicles in identifying patients with colorectal neoplasms.ResultsTotal plasma microvesicles, and sub‐populations positive for CD31, CD42a, CD31+/CD42a‐, EPHB2, ICAM and LGR5 (component factor‐1) were able to identify patients with BCRP and CRC with a receiver operator curve (AUC) accuracy of a 100% (95% CI: 100%–100%) and 95% (95% CI: 88%–100%), respectively. To identify patients with BCRP, a cut‐off point value of component factor‐1761 microvesicles/μl demonstrated a 100% sensitivity, specificity and negative predictive value (NPV) and a 93% positive predictive value (PPV). To identify patients with CRC, a cut‐off value of component factor‐1 3439 microvesicles/μl demonstrated a 100% sensitivity, specificity and NPV and a 65% PPV. CEA+ microvesicles sub‐population were significantly (p < 0.02) higher in CRC in comparison to BCRP.ConclusionsMicrovesicles as biomarkers for the early and accurate detection of CRC is a simple and effective tool that yields a potential breakthrough in clinical management.

98 Plasma Extracellular Vesicles Released After Sever Burn Injury Modulate Macrophage Function

IntroductionExtracellular microvesicles (MVs) have emerged as key regulators of immune function across multiple diseases and potential biomarkers. Severe burn injury is a devastating trauma with significant immune dysfunction that results in an ~12% mortality rate due to sepsis-induced organ failure, pneumonia, and other infections. Severe burn causes a biphasic immune response: an early (0-72 hrs) hyper-inflammatory state, with release of pro-inflammatory damage-associated molecular pattern molecules (DAMPs), such as HMGB1, and cytokines (e.g.IL-1b), followed by an immunosuppressive state (1-2 weeks post injury), associated with increased susceptibility to life-threatening infections. We have reported that early after severe burn injury HMGB1 and IL-1b are enriched in plasma microvesicles (MVs), suggesting a role for MVs in post-burn immune activation. Here we tested the impact of MVs isolated after burn injury on phenotypic and functional consequences in vivo and in vitro using adoptive MV transfers.MethodsWe then assessed if the cargo of MVs following burn injury in humans could predict length of hospital stay. MVs isolated early from mice that underwent a 20% total body surface area (TBSA) burn injury (burn MVs) caused similar cytokine responses in naïve mice to those seen in burned mice early after injury. Burn MVs transferred to RAW264.7 macrophages caused similar functional (i.e. cytokine secretion) and genetic changes (measured by NanoStringTM) seen with their associated phase of post-burn immune dysfunction.ResultsBurn MVs isolated early (24h) induced MCP-1, IL-12p70 and IFNg, while MVs isolated later (1 and 2 weeks) blunted RAW proinflammatory responses to bacterial endotoxin (LPS). Unbiased LC-MS / MS proteomic analysis of early EVS (< 72 h post-injury) showed similarities in human and mice.ConclusionsIn our sample of large burn injury, EV SAA1 and CRP correlated with TBSA injury in both sexes and were correlated with length of hospital stay in women.

Исследование взаимосвязи состава микровезикул крови беременных с последующими плацента-ассоциированными осложнениями

Study Objective: To find the relationship between the levels of mitochondrial signal protein sequences in blood microvesicles of pregnant women and subsequent development of foetal growth retardation syndrome (FGRS), low birth-weight baby, preeclampsia (PE) or foetuses and newborns with normal weight and height. Study Design: Prospective comparative study. Materials and Methods. The microvesicular blood plasma fraction of women with placenta-associated complications in the outcome of previous pregnancies was studied as a risk group for their recurrence (n = 96). The study group was divided into 4 sub-groups: sub-group IА included 32 patients with pregnancies complicated with FGRS; sub-group IB comprised 20 patients with FGRS and PE; sub-group IC included 24 pregnant women, whose newborns were small for gestation age; sub-group ID was 20 pregnant women with a history of placenta-associated complications and abnormal Doppler velocimetry results, whose postnatal weight and height did not differ from normal values. The control group consisted of 20 women with a physiological course of pregnancy. The microvesicular fraction of the peripheral blood of the patients was obtained by differential plasma ultracentrifugation. Protein of the outer membrane of mitochondria (VDAC1), mitochondrial DNA transcription and replication activator (TFAM), recombinant protein of the outer membrane of mitochondria (MFN2), and TAZ protein encoding cardiolipin modelling in oxidative damage were measured by western blot analysis using a monoclonal antibody panel. Study Results. Plasma microvesicles in patients with subsequent placenta-associated complications demonstrated decreased levels of a number of mitochondrial proteins (VDAC1, TFAM, MFN2, OPA1). Levels of these proteins determine successful intercellular signaling on the adequate functional activity of mitochondria, their integrity and normal biogenesis. Conclusion. The obtained results allow to make a conclusion about a pronounced violation of mitochondrial biogenesis in the body of women with intrauterine growth restriction, which probably makes a serious contribution to the development of pathology and its progression. Keywords: foetal growth retardation syndrome, microvesicles, habitual abortion, placental insufficiency, preeclampsia, mitochondria, pregnancy.

Effect of Kidney Transplantation on Accelerated Immunosenescence and Vascular Changes Induced by Chronic Kidney Disease.

Kidney transplantation is the best option for patients with end-stage renal disease. Despite the improvement in cardiovascular burden (leading cause of mortality among patients with chronic kidney disease), cardiovascular adverse outcomes related to the inflammatory process remain a problem. Thus, the aim of the present study was to characterize the immune profile and microvesicles of patients who underwent transplantation. We investigated the lymphocyte phenotype (CD3, CD4, CD8, CD19, and CD56) and monocyte phenotype (CD14, CD16, CD86, and CD54) in peripheral blood, and endothelium-derived microvesicles (annexin V+CD31+CD41–) in plasma of patients with advanced chronic kidney disease (n = 40), patients with transplantation (n = 40), and healthy subjects (n = 18) recruited from the University Hospital “12 de Octubre” (Madrid, Spain). Patients with kidney transplantation had B-cell lymphopenia, an impairment in co-stimulatory (CD86) and adhesion (CD54) molecules in monocytes, and a reduction in endothelium-derived microvesicles in plasma. The correlations between those parameters explained the modifications in the expression of co-stimulatory and adhesion molecules in monocytes caused by changes in lymphocyte populations, as well as the increase in the levels of endothelial-derived microvesicles in plasma caused by changes in lymphocyte and monocytes populations. Immunosuppressive treatment could directly or indirectly induce those changes. Nevertheless, the particular characteristics of these cells may partly explain the persistence of cardiovascular and renal alterations in patients who underwent transplantation, along with the decrease in arteriosclerotic events compared with advanced chronic kidney disease. In conclusion, the expression of adhesion molecules by monocytes and endothelial-derived microvesicles is related to lymphocyte alterations in patients with kidney transplantation.

Abstract MP03: Histone-mediated Platelet Activation And Microvesicle-induced Thrombin Generation In COVID-19

Background: Severe COVID-19 leads to inflammation and coagulopathy with progression to multiple organ failure. Several prothrombotic mechanisms have been proposed, including NETosis with release of citrullinated histones, platelet hyperactivation, and generation of procoagulant microvesicles. Aims: We hypothesized that histones derived from NETosis promote platelet activation and release of microvesicles that mechanistically contribute to thrombin generation and thrombosis in COVID-19. Methods: Platelet poor plasma (PPP) was prepared from 136 COVID-19 patients enrolled in a multicenter randomized clinical trial comparing standard prophylactic dose to intermediate dose enoxaparin in hospitalized patients with COVID-19 (NCT04360824). We also prepared PPP and washed platelets from 53 healthy subjects. We measured citrullinated histone H3 (H3Cit) by ELISA, microvesicles by flow cytometry, and thrombin generation using the Calibrated Automated Thrombogram. Ex vivo platelet adhesion and thrombus growth on collagen was measured in a microfluidic chamber. Results: Compared to healthy subjects, COVID-19 patients had elevated plasma levels of H3Cit and platelet-derived microvesicles. When PPP was triggered with exogenous tissue factor and phospholipids, higher endogenous thrombin potential, peak thrombin, and velocity index were observed in COVID-19 patients compared to healthy subjects. Increased thrombin generation with COVID-19 PPP was evident even when triggered without added phospholipids, suggesting the presence of procoagulant microvesicles in COVID-19 plasma. Enhanced thrombin generation also was observed after transfer of microvesicles isolated from COVID-19 patient plasma to control PPP. Incubation of control platelets with PPP from COVID-19 patients but not healthy subjects caused increased platelet-dependent thrombin generation and larger platelet-thrombi under venous shear stress. These effects of COVID-19 plasma on platelet-dependent thrombin generation and platelet-thrombi formation were inhibited by a histone aptamer. Conclusions: We conclude that histone-mediated platelet activation promotes thrombosis in COVID-19 in part via increased thrombin generation driven by microvesicles.

Small Annexin V-Positive Platelet-Derived Microvesicles Affect Prognosis in Cirrhosis: A Longitudinal Study.

INTRODUCTION:Microvesicles (MVs) with procoagulant properties may favor liver parenchymal extinction, then cirrhosis-related complications and mortality. In a longitudinal cohort of cirrhotic patients, we measured plasma levels of platelet-derived MVs (PMVs), endothelial-derived MVs, and red blood cell–derived MVs, expressing phosphatidylserine (annexin V–positive [AV+]) or not, and evaluated their impact on Model for End-Stage Liver Disease (MELD) score and transplant-free survival.METHODS:MVs were quantified using flow cytometry in plasma from 90 noninfected cirrhotic patients and 10 healthy volunteers matched for age and sex. Impact of plasma microvesicle levels on 6-month transplant-free survival was assessed using log-rank tests and logistic regression.RESULTS:Microvesicle levels, mostly platelet-derived, were 2.5-fold higher in healthy volunteers compared with cirrhotic patients. Circulating small AV+ PMV levels were lower in cirrhotic patients (P = 0.014) and inversely correlated with MELD scores (R = −0.28; P = 0.0065). During 1-year follow-up, 8 patients died and 7 underwent liver transplantation. In the remaining patients, circulating microvesicle levels did not change significantly. Six-month transplant-free survival was lower in patients with low baseline small AV+ PMV levels (72.6% vs 96.2%; P = 0.0007). In multivariate analyses adjusted for age, ascites, esophageal varices, encephalopathy, clinical decompensation, total platelet counts, MELD score, and/or Child-Pugh C stage, patients with lower small AV+ PMV levels had a significant 5- to 8-fold higher risk of 6-month death or liver transplant. Other PMV levels did not impact on survival.DISCUSSION:Decreased circulating small AV+ PMV levels are associated with significantly lower transplant-free survival in cirrhotic patients independently of MELD score and platelet counts.

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.

Extracellular vesicle interplay in cardiovascular pathophysiology.

Extracellular vesicles (EVs) are nanosized lipid bilayer-delimited particles released from cells that mediate intercellular communications and play a pivotal role in various physiological and pathological processes. Subtypes of EVs may include plasma membrane ectosomes or microvesicles and endosomal origin exosomes, although functional distinctions remain unclear. EVs carry cargo proteins, nucleic acids (RNA and DNA), lipids, and metabolites. By presenting or transferring this cargo to recipient cells, EVs can trigger cellular responses. We summarize contemporary understanding of EV biogenesis, composition, and function, with an emphasis on the role of EVs in the cardiovascular system. In addition, we outline the functional relevance of EVs in cardiovascular pathophysiology, further highlighting their potential for diagnostic and therapeutic applications.

Effects of endothelial progenitor cell therapy on microrna expression profiles in plasma, platelets and platelet-derived microvesicles in atherosclerosis

Background and Aims: The purpose was to investigate the effects of transplantation of endothelial progenitor cells (EPCs) on expressed profiles of miRNAs in plasma, platelets and platelet-derived microvesicles (PMVs) obtained from experimental induced atherosclerosis animal model.

Abstract 16683: Profiling Cardiac Inflammation and Molecular Changes During the Transition of Hypertrophic to Dilated Cardiomyopathy

Introduction: Hypertrophic cardiomyopathy (HCM) is a disease caused primarily by sarcomere gene mutations [like myosin-binding protein C3 ( MYBPC3 )], with several distinct phenotypes. Tissue-level inflammation has been reported in human HCM, tissue-specific neutrophil subsets, and their dysregulation cause inflammatory myopathies, and neutrophil extracellular traps (NETs) are associated with cardiac fibrosis in aged rodents. However, the mechanism(s) responsible for the broad phenotypic variability and changes observed over time transitioning from HCM to dilated cardiomyopathy (DCM) has not yet been elucidated. Objective: To determine the cardiac inflammatory signature of HCM and transition from HCM to DCM and its relationship to fibrosis and ventricular remodeling in an established MYBPC3 ( cMyBP-C t/t ) mouse model. Method and Results: Mixed-gender cMyBP-C +/+ (WT) and mutant mice ( cMyBP-C t/t ) underwent echocardiography and were euthanized at one, two and three months of age (n=8) and blood and hearts were harvested. Echocardiography and histopathology examination confirmed significant heart dysfunction and tissue remodeling in cMyBP-C t/t mice showing cardiac hypertrophy at one month of age (Left ventricular (LV) posterior wall systole 1.20 ±0.39 vs 1.51±0.49 and LV posterior wall diastole 0.96 ±0.22 vs 1.38 ±0.36 mm; * p&lt;0.05 ), and DCM phenotype (LV internal diameter systole 2.40 ±0.41 vs 3.67 ±0.25 and LV internal diameter diastole 3.44 ±0.29 vs 4.30 ±0.39 mm; * p&lt;0.05 ) along with myofibrillar loss and increased cardiac fibrosis at three months. Interestingly, LV dysfunction and hypertrophy resulted in a time-dependent increase in the activation of coagulation, as measured by plasma microvesicle tissue factor activity, thrombin antithrombin, and D-dimer. In silico analysis of RNA-Seq data from 3-months old cMyBP-C t/t mice heart revealed key genes and pathways associated with HCM, DCM, tissue remodeling, renin-angiotensin-aldosterone signaling, fibrosis, apoptosis, NETosis, and inflammation. Conclusions: The transition from HCM to a DCM phenotype involves proinflammatory and profibrotic signaling. Therapies directed at tissue-specific inflammation and NETs may be a novel and impactful strategy for HCM.

Using a lactadherin-immobilized silicon surface for capturing and monitoring plasma microvesicles as a foundation for diagnostic device development

Microvesicles (MVs) are found in several types of body fluids and are promising disease biomarkers and therapeutic targets. This study aimed to develop a novel biofunctionalized surface for binding plasma microvesicles (PMVs) based on a lab-on-a-chip (LOC) approach. A new lactadherin (LACT)-functionalized surface was prepared and examined for monitoring PMVs. Moreover, two different strategies of LACT immobilization on a silicon surface were applied to compare different LACT orientations. A higher PMV to LACT binding efficiency was observed for LACT bonded to an αvβ3 integrin–functionalized surface compared with that for LACT directly bonded to a glutaraldehyde-modified surface. Effective binding of PMVs and its components for both LACT immobilization strategies was confirmed using spectral ellipsometry and time-of-flight secondary ion mass spectrometry methods. The proposed PMV capturing system can be used as a foundation to design novel point-of-care (POC) diagnostic devices to detect and characterize PMVs in clinical samples.Graphical