Exosomes in Cardiovascular Diseases: Pathological Potential of Nano-Messenger

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 Vesicle Preparation and Analysis: A State-of-the-Art Review

In recent decades, research on Extracellular Vesicles (EVs) has gained prominence in the life sciences due to their critical roles in both health and disease states, offering promising applications in disease diagnosis, drug delivery, and therapy. However, their inherent heterogeneity and complex origins pose significant challenges to their preparation, analysis, and subsequent clinical application. This review is structured to provide an overview of the biogenesis, composition, and various sources of EVs, thereby laying the groundwork for a detailed discussion of contemporary techniques for their preparation and analysis. Particular focus is given to state-of-the-art technologies that employ both microfluidic and non-microfluidic platforms for EV processing. Furthermore, this discourse extends into innovative approaches that incorporate artificial intelligence and cutting-edge electrochemical sensors, with a particular emphasis on single EV analysis. This review proposes current challenges and outlines prospective avenues for future research. The objective is to motivate researchers to innovate and expand methods for the preparation and analysis of EVs, fully unlocking their biomedical potential.

A brief review on recent advances in diagnostic and therapeutic applications of extracellular vesicles in cardiovascular disease

Extracellular vesicles (EVs) are important mediators of intercellular communication within the cardiovascular system, playing essential roles in physiological homeostasis and contributing to the pathogenesis of various cardiovascular diseases (CVDs). However, their potential as diagnostic biomarkers and therapeutic agents in rare cardiovascular diseases, such as valvular heart disease (VHD) and cardiomyopathies, remains largely unexplored. This review comprehensively emphasizes recent advancements in extracellular vesicle research, explicitly highlighting their growing significance in diagnosing and potentially treating rare cardiovascular diseases, with a particular focus on valvular heart disease and cardiomyopathies. We highlight the potential of extracellular vesicle-based liquid biopsies as non-invasive tools for early disease detection and risk stratification, showcasing specific extracellular vesicle-associated biomarkers (proteins, microRNAs, lipids) with diagnostic and prognostic value. Furthermore, we discussed the therapeutic promise of extracellular vesicles derived from various sources, including stem cells and engineered extracellular vesicles, for cardiac repair and regeneration through their ability to modulate inflammation, promote angiogenesis, and reduce fibrosis. By integrating the findings and addressing critical knowledge gaps, this review aims to stimulate further research and innovation in extracellular vesicle-based diagnostics and therapeutics of cardiovascular disease.

Extracellular vesicles transport RNA between cells: Unraveling their dual role in diagnostics and therapeutics

Modern methods of molecular diagnostics and therapy have revolutionized the field of medicine in recent years by providing more precise and effective tools for detecting and treating diseases. This progress includes a growing exploration of the body's secreted vesicles, known as extracellular vesicles (EVs), for both diagnostic and therapeutic purposes. EVs are a heterogeneous population of lipid bilayer vesicles secreted by almost every cell type studied so far. They are detected in body fluids and conditioned culture media from living cells. EVs play a crucial role in communication between cells and organs, both locally and over long distances. They are recognized for their ability to transport endogenous RNA and proteins between cells, including messenger RNA (mRNA), microRNA (miRNA), misfolded neurodegenerative proteins, and several other biomolecules. This review explores the dual utilization of EVs, serving not only for diagnostic purposes but also as a platform for delivering therapeutic molecules to cells and tissues. Through an exploration of their composition, biogenesis, and selective cargo packaging, we elucidate the intricate mechanisms behind RNA transport between cells via EVs, highlighting their potential use for both diagnostic and therapeutic applications. Finally, it addresses challenges and outlines prospective directions for the clinical utilization of EVs.

EVs-miR-17-5p attenuates the osteogenic differentiation of vascular smooth muscle cells potentially via inhibition of TGF-β signaling under high glucose conditions

Vascular calcification, which is a major complication of diabetes mellitus, is an independent risk factor for cardiovascular disease. Osteogenic differentiation of vascular smooth muscle cells (VSMCs) is one of the key mechanisms underlying vascular calcification. Emerging evidence suggests that macrophage-derived extracellular vesicles (EVs) may be involved in calcification within atherosclerotic plaques in patients with diabetes mellitus. However, the role of macrophage-derived EVs in the progression of vascular calcification is largely unknown. In this study, we investigated whether macrophage-derived EVs contribute to the osteogenic differentiation of VSMCs under high glucose conditions. We isolated EVs that were secreted by murine peritoneal macrophages under normal glucose (EVs-NG) or high glucose (EVs-HG) conditions. miRNA array analysis in EVs from murine macrophages showed that miR-17-5p was significantly increased in EVs-HG compared with EVs-NG. Prediction analysis with miRbase identified transforming growth factor β receptor type II (TGF-β RII) as a potential target of miR-17-5p. EVs-HG as well as miR-17-5p overexpression with lipid nanoparticles inhibited the gene expression of Runx2, and TGF-β RII. Furthermore, we demonstrated that VSMCs transfected with miR-17-5p mimic inhibited calcium deposition. Our findings reveal a novel role of macrophage-derived EVs in the negative regulation of osteogenic differentiation in VSMCs under high glucose conditions.

Current concepts in the epigenetic regulation of cardiac fibrosis

Cardiac fibrosis is a significant driver of congestive heart failure, a syndrome that continues to affect a growing patient population globally. Cardiac fibrosis results from a constellation of complex processes at the transcription, receptor, and signaling axes levels. Various mediators and signaling cascades, such as the transformation growth factor-beta pathway, have been implicated in the pathophysiology of cardiac tissue fibrosis. Our understanding of these markers and pathways has improved in recent years as more advanced technologies and assays have been developed, allowing for better delineation of the crosstalk between specific factors. There is mounting evidence suggesting that epigenetic modulation plays a pivotal role in the progression of cardiac fibrosis. Transcriptional regulation of key pro- and antifibrotic pathways can accentuate or blunt the rate and extent of fibrosis at the tissue level. Exosomes, micro-RNAs, and long noncoding RNAs all belong to factors that can impact the epigenetic signature in cardiac fibrosis. Herein, we comprehensively review the latest literature about exosomes, their contents, and cardiac fibrosis. In doing so, we highlight the specific transcriptional factors with pro- or antifibrotic properties. We also assimilate the data supporting these mediators' potential utility as diagnostic or prognostic biomarkers. Finally, we offer insight into where further work can be done to fill existing gaps to translate preclinical findings better and improve clinical outcomes.

Tipifarnib Reduces Extracellular Vesicles and Protects From Heart Failure

BACKGROUND

Heart failure (HF) is one of the leading causes of mortality worldwide. Extracellular vesicles, including small extracellular vesicles or exosomes, and their molecular cargo are known to modulate cell-to-cell communication during multiple cardiac diseases. However, the role of systemic extracellular vesicle biogenesis inhibition in HF models is not well documented and remains unclear.

METHODS

We investigated the role of circulating exosomes during cardiac dysfunction and remodeling in a mouse transverse aortic constriction (TAC) model of HF. Importantly, we investigate the efficacy of tipifarnib, a recently identified exosome biogenesis inhibitor that targets the critical proteins (Rab27a [Ras associated binding protein 27a], nSMase2 [neutral sphingomyelinase 2], and Alix [ALG-2-interacting protein X]) involved in exosome biogenesis for this mouse model of HF. In this study, 10-week-old male mice underwent TAC surgery were randomly assigned to groups with and without tipifarnib treatment (10 mg/kg 3 times/wk) and monitored for 8 weeks, and a comprehensive assessment was conducted through performed echocardiographic, histological, and biochemical studies.

RESULTS

TAC significantly elevated circulating plasma exosomes and markedly increased cardiac left ventricular dysfunction, cardiac hypertrophy, and fibrosis. Furthermore, injection of plasma exosomes from TAC mice induced left ventricular dysfunction and cardiomyocyte hypertrophy in uninjured mice without TAC. On the contrary, treatment of tipifarnib in TAC mice reduced circulating exosomes to baseline and remarkably improved left ventricular functions, hypertrophy, and fibrosis. Tipifarnib treatment also drastically altered the miRNA profile of circulating post-TAC exosomes, including miR 331-5p, which was highly downregulated both in TAC circulating exosomes and in TAC cardiac tissue. Mechanistically, miR 331-5p is crucial for inhibiting the fibroblast-to-myofibroblast transition by targeting HOXC8, a critical regulator of fibrosis. Tipifarnib treatment in TAC mice upregulated the expression of miR 331-5p that acts as a potent repressor for one of the fibrotic mechanisms mediated by HOXC8.

CONCLUSIONS

Our study underscores the pathological role of exosomes in HF and fibrosis in response to pressure overload. Tipifarnib-mediated inhibition of exosome biogenesis and cargo sorting may serve as a viable strategy to prevent progressive cardiac remodeling in HF.

The potential mechanisms and treatment effects of stem cell-derived exosomes in cardiac reengineering

Exosomes are extracellular vesicles of diverse compositions that are secreted by numerous cell types. Exosomes contain significant bioactive components, including lipids, proteins, mRNA, and miRNA. Exosomes play an important role in regulating cellular signaling and trafficking under both normal physiological and pathological circumstances. A multitude of factors, including thermal stress, ribosomal stress, endoplasmic reticulum stress, and oxidative stress influence the concentrations of exosomal mRNA, miRNA, proteins, and lipids. It has been stated that exosomes derived from stem cells (SCs) modulate a range of stresses by preventing or fostering cell balance. Exosomes derived from SCs facilitate recovery by facilitating cross-cellular communication via the transmission of information in the form of proteins, lipids, and other components. For this reason, exosomes are used as biomarkers to diagnose a wide variety of diseases. The focus of this review is the bioengineering of artificial exosomal cargoes. This process encompasses the control and transportation of particular exosomal cargoes, including but not limited to small molecules, recombinant proteins, immune modulators, and therapeutic medications. Therapeutic approaches of this nature have the potential to deliver therapeutic medications precisely to the intended site for the cure of a variety of disorders. Notably, our attention has been directed towards the therapeutic implementations of exosomes derived from SCs in the cure of cardiovascular ailments, including but not limited to ischemic heart disease, myocardial infarction, sepsis, heart failure, cardiomyopathy, and cardiac fibrosis. In general, researchers employ two methodologies when it comes to exosomal bioengineering. This review aims to explain the function of exosomes derived from SCs in the regulation of stress and present a novel therapeutic approach for cardiovascular disorders.

Development and Validation of a Mortality Risk Score for Repaired Tetralogy of Fallot

BACKGROUND

Robust risk assessment is crucial for the growing repaired tetralogy of Fallot population at risk of major adverse clinical outcomes; however, current tools are hindered by lack of validation. This study aims to develop and validate a risk prediction model for death in the repaired tetralogy of Fallot population.

METHODS AND RESULTS

Patients with repaired tetralogy of Fallot enrolled in the INDICATOR (International Multicenter Tetralogy of Fallot Registry) cohort with clinical, arrhythmia, cardiac magnetic resonance, and outcome data were included. Patients from London, Amsterdam, and Boston sites were placed in the development cohort; patients from the Toronto site were used for external validation. Multivariable Cox regression was used to evaluate factors associated with time from cardiac magnetic resonance until the primary outcome: all-cause death. Of 1552 eligible patients (n=1221 in development, n=331 in validation; median age at cardiac magnetic resonance 23.4 [interquartile range, 15.6-35.6] years; median follow up 9.5 years), 102 (6.6%) experienced the primary outcome. The multivariable Cox model performed similarly during development (concordance index, 0.83 [95% CI, 0.78-0.88]) and external validation (concordance index, 0.80 [95% CI, 0.71-0.90]) and identified older age at cardiac magnetic resonance, obesity, type of tetralogy of Fallot repair, higher right ventricular end-systolic volume index, and lower biventricular global function index as independent predictors of death. A risk-scoring algorithm dividing patients into low-risk (score ≤4) versus high-risk (score >4) groups was validated to effectively discriminate risk of death (15-year survival of 95% versus 74%, respectively; P<0.001).

CONCLUSIONS

This externally validated mortality risk prediction algorithm can help identify vulnerable patients with repaired tetralogy of Fallot who may benefit from targeted interventions.

Environmental pollutants and exosomes: A new paradigm in environmental health and disease

This study investigates the intricate interplay between environmental pollutants and exosomes, shedding light on a novel paradigm in environmental health and disease. Cellular stress, induced by environmental toxicants or disease, significantly impacts the production and composition of exosomes, crucial mediators of intercellular communication. The heat shock response (HSR) and unfolded protein response (UPR) pathways, activated during cellular stress, profoundly influence exosome generation, cargo sorting, and function, shaping intercellular communication and stress responses. Environmental pollutants, particularly lipophilic ones, directly interact with exosome lipid bilayers, potentially affecting membrane stability, release, and cellular uptake. The study reveals that exposure to environmental contaminants induces significant changes in exosomal proteins, miRNAs, and lipids, impacting cellular function and health. Understanding the impact of environmental pollutants on exosomal cargo holds promise for biomarkers of exposure, enabling non-invasive sample collection and real-time insights into ongoing cellular responses. This research explores the potential of exosomal biomarkers for early detection of health effects, assessing treatment efficacy, and population-wide screening. Overcoming challenges requires advanced isolation techniques, standardized protocols, and machine learning for data analysis. Integration with omics technologies enhances comprehensive molecular analysis, offering a holistic understanding of the complex regulatory network influenced by environmental pollutants. The study underscores the capability of exosomes in circulation as promising biomarkers for assessing environmental exposure and systemic health effects, contributing to advancements in environmental health research and disease prevention.

Unveiling the Role of Exosomes in the Pathophysiology of Sepsis: Insights into Organ Dysfunction and Potential Biomarkers

Extracellular vesicles (EVs) are tools for intercellular communication, mediating molecular transport processes. Emerging studies have revealed that EVs are significantly involved in immune processes, including sepsis. Sepsis, a dysregulated immune response to infection, triggers systemic inflammation and multi-organ dysfunction, posing a life-threatening condition. Although extensive research has been conducted on animals, the complex inflammatory mechanisms that cause sepsis-induced organ failure in humans are still not fully understood. Recent studies have focused on secreted exosomes, which are small extracellular vesicles from various body cells, and have shed light on their involvement in the pathophysiology of sepsis. During sepsis, exosomes undergo changes in content, concentration, and function, which significantly affect the metabolism of endothelia, cardiovascular functions, and coagulation. Investigating the role of exosome content in the pathogenesis of sepsis shows promise for understanding the molecular basis of human sepsis. This review explores the contributions of activated immune cells and diverse body cells' secreted exosomes to vital organ dysfunction in sepsis, providing insights into potential molecular biomarkers for predicting organ failure in septic shock.

The Landscape of Exosomes Biogenesis to Clinical Applications

Exosomes are extracellular vesicles that originate from various cells and mediate intercellular communication, altering the behavior or fate of recipient cells. They carry diverse macromolecules, such as lipids, proteins, carbohydrates, and nucleic acids. Environmental stressors can change the exosomal contents of many cells, making them useful for diagnosing many chronic disorders, especially neurodegenerative, cardiovascular, cancerous, and diabetic diseases. Moreover, exosomes can be engineered as therapeutic agents to modulate disease processes. State-of-art techniques are employed to separate exosomes including ultracentrifugation, size-exclusion chromatography and immunoaffinity. However, modern technologies such as aqueous two-phase system as well as microfluidics are gaining attention in the recent years. The article highlighted the composition, biogenesis, and implications of exosomes, as well as the standard and novel methods for isolating them and applying them as biomarkers and therapeutic cargo carriers.

Exosomes: Methods for Isolation and Characterization in Biological Samples

Exosomes are small lipid bilayer-encapsulated nanosized extracellular vesicles of endosomal origin. Exosomes are secreted by almost all cell types and are a crucial player in intercellular communication. Exosomes transmit cellular information from donor to recipient cells in the form of proteins, lipids, and nucleic acids and influence several physiological and pathological responses. Due to their capacity to carry a variety of cellular cargo, low immunogenicity and cytotoxicity, biocompatibility, and ability to cross the blood-brain barrier, these nanosized vesicles are considered excellent diagnostic tools and drug-delivery vehicles. Despite their tremendous potential, the progress in therapeutic applications of exosomes is hindered by inadequate isolation techniques, poor characterization, and scarcity of specific biomarkers. The current research in the field is focused on overcoming these limitations. In this chapter, we have reviewed conventional exosome isolation and characterization methods and recent advancements, their advantages and limitations, persistent challenges in exosome research, and future directions.

Unraveling the Intricate Roles of Exosomes in Cardiovascular Diseases: A Comprehensive Review of Physiological Significance and Pathological Implications

Exosomes, as potent intercellular communication tools, have garnered significant attention due to their unique cargo-carrying capabilities, which enable them to influence diverse physiological and pathological functions. Extensive research has illuminated the biogenesis, secretion, and functions of exosomes. These vesicles are secreted by cells in different states, exerting either protective or harmful biological functions. Emerging evidence highlights their role in cardiovascular disease (CVD) by mediating comprehensive interactions among diverse cell types. This review delves into the significant impacts of exosomes on CVD under stress and disease conditions, including coronary artery disease (CAD), myocardial infarction, heart failure, and other cardiomyopathies. Focusing on the cellular signaling and mechanisms, we explore how exosomes mediate multifaceted interactions, particularly contributing to endothelial dysfunction, oxidative stress, and apoptosis in CVD pathogenesis. Additionally, exosomes show great promise as biomarkers, reflecting differential expressions of NcRNAs (miRNAs, lncRNAs, and circRNAs), and as therapeutic carriers for targeted CVD treatment. However, the specific regulatory mechanisms governing exosomes in CVD remain incomplete, necessitating further exploration of their characteristics and roles in various CVD-related contexts. This comprehensive review aims to provide novel insights into the biological implications of exosomes in CVD and offer innovative perspectives on the diagnosis and treatment of CVD.

MiR-128-3p promotes the progression of deep venous thrombosis through binding SIRT1

OBJECTIVES

This research aimed to study the effect of microRNA-128-3p (miR-128-3p) on deep venous thrombosis (DVT).

METHOD

The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, Transwell chamber method, and flow cytometry technique were used in the cell experiments. Potential interconnection between miR-128-3p and silent information regulator sirtuin 1 (SIRT1) was revealed by luciferase activity. The concentration of miR-128-3p and mRNA SIRT1 was assessed by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The receiver operating characteristic (ROC) curve was used to test the predictive effect of miR-128-3p in DVT.

RESULTS

Decreased miR-128-3p expression was beneficial to cell proliferation and migration and inhibited inflammation, apoptosis, and adhesion of human umbilical vein endothelial cells (HUVECs). The impacts of miR-128-3p on HUVECs were achieved by targeting SIRT1. MiR-128-3p was upregulated in patients with DVT, and it was of great significance in differentiating patients with DVT.

CONCLUSION

Overexpression of miR-128-3p might become a biomarker for patients with DVT.

Therapeutic Potential of EVs: Targeting Cardiovascular Diseases

Due to their different biological functions, extracellular vesicles (EVs) have great potential from a therapeutic point of view. They are released by all cell types, carrying and delivering different kinds of biologically functional cargo. Under pathological events, cells can increase their secretion of EVs and can release different amounts of cargo, thus making EVs great biomarkers as indicators of pathological progression. Moreover, EVs are also known to be able to transport and deliver cargo to different recipient cells, having an important role in cellular communication. Interestingly, EVs have recently been explored as biological alternatives for the delivery of therapeutics, being considered natural drug delivery carriers. Because cardiovascular disorders (CVDs) are the leading cause of death worldwide, in this review, we will discuss the up-to-date knowledge regarding the biophysical properties and biological components of EVs, focusing on myocardial infarction, diabetic cardiomyopathy, and sepsis-induced cardiomyopathy, three very different types of CVDs.

BMSC-derived extracellular vesicles promoted osteogenesis via Axin2 inhibition by delivering MiR-16-5p

Osteoporosis (OP) is a systemic bone disease caused by an imbalance in osteogenesis and osteoclastic resorption. Extracellular vesicles (EVs)-encapsulated miRNAs from bone mesenchymal stem cells (BMSCs) have been reported to participate in osteogenesis. MiR-16-5p is one of the miRNAs that regulates osteogenic differentiation; however, studies have shown that its role in osteogenesis is controversial. Thus, this study aims to investigate the role of miR-16-5p from BMSC-derived extracellular vesicles (EVs) in osteogenic differentiation and uncover the underlying mechanisms. In this study, we used an ovariectomized (OVX) mouse model and an H₂O₂-treated BMSCs model to investigate the effects of BMSC-derived EVs and EV-encapsulated miR-16-5p on OP and the underlying mechanisms. Our results proved that the miR-16-5p level was significantly decreased in H₂O₂-treated BMSCs, bone tissues of OVX mice, and lumbar lamina tissues from osteoporotic women. EVs-encapsulated miR-16-5p from BMSCs could promote osteogenic differentiation. Moreover, the miR-16-5p mimics promoted osteogenic differentiation of H₂O₂-treated BMSCs, and the effects exerted by miR-16-5p were mediated by targeting Axin2, a scaffolding protein of GSK3β that negatively regulates the Wnt/β-catenin signaling pathway. This study provides evidence that EVs-encapsulated miR-16-5p from BMSCs could promote osteogenic differentiation by repressing Axin2.

Small extracellular vesicles from pregnant women with maternal supraphysiological hypercholesterolemia impair endothelial cell function in vitro

Maternal physiological hypercholesterolemia (MPH, maternal total cholesterol (TC) levels at term of pregnancy ≤280 mg/dl) occurs to assure fetal development. Maternal supraphysiological hypercholesterolemia (MSPH, TC levels >280 mg/dl) is a pathological condition associated with maternal, placental, and fetal endothelial dysfunction and early neonatal atherosclerosis development. Small extracellular vesicles (sEVs) are delivered to the extracellular space by different cells, where they modulate cell functions by transporting active signaling molecules, including proteins and miRNA.

AIM

To determine whether sEVs from MSPH women could alter the function of endothelial cells (angiogenesis, endothelial activation and nitric oxide synthesis capacity).

METHODS

This study included 24 Chilean women (12 MPH and 12 MSPH). sEVs were isolated from maternal plasma and characterized by sEV markers (CD9, Alix and HSP70), nanoparticle tracking analysis, transmission electron microscopy, and protein and cholesterol content. The endothelial cell line HMEC-1 was used to determine the uptake of labeled sEVs and the effects of sEVs on cell viability, endothelial tube formation, endothelial cell activation, and endothelial nitric oxide expression and function.

RESULTS

In MSPH women, the plasma concentration of sEVs was increased compared to that in MPH women. MSPH-sEVs were highly taken up by HMEC-1 cells and reduced angiogenic capacity and the expression and activity of eNOS without changing cell viability or endothelial activation.

CONCLUSION

sEVs from MSPH women impair angiogenesis and nitric oxide synthesis in endothelial cells, which could contribute to MSPH-associated endothelial dysfunction.

Frontier Review of the Molecular Mechanisms and Current Approaches of Stem Cell-Derived Exosomes

Exosomes are effective therapeutic vehicles that may transport their substances across cells. They are shown to possess the capacity to affect cell proliferation, migration, anti-apoptosis, anti-scarring, and angiogenesis, via the action of transporting molecular components. Possessing immense potential in regenerative medicine, exosomes, especially stem cell-derived exosomes, have the advantages of low immunogenicity, minimal invasiveness, and broad clinical applicability. Exosome biodistribution and pharmacokinetics may be altered, in response to recent advancements in technology, for the purpose of treating particular illnesses. Yet, prior to clinical application, it is crucial to ascertain the ideal dose and any potential negative consequences of an exosome. This review focuses on the therapeutic potential of stem cell-derived exosomes and further illustrates the molecular mechanisms that underpin their potential in musculoskeletal regeneration, wound healing, female infertility, cardiac recovery, immunomodulation, neurological disease, and metabolic regulation. In addition, we provide a summary of the currently effective techniques for isolating exosomes, and describe the innovations in biomaterials that improve the efficacy of exosome-based treatments. Overall, this paper provides an updated overview of the biological factors found in stem cell-derived exosomes, as well as potential targets for future cell-free therapeutic applications.

Indirect epigenetic testing identifies a diagnostic signature of cardiomyocyte DNA methylation in heart failure

Precision-based molecular phenotyping of heart failure must overcome limited access to cardiac tissue. Although epigenetic alterations have been found to underlie pathological cardiac gene dysregulation, the clinical utility of myocardial epigenomics remains narrow owing to limited clinical access to tissue. Therefore, the current study determined whether patient plasma confers indirect phenotypic, transcriptional, and/or epigenetic alterations to ex vivo cardiomyocytes to mirror the failing human myocardium. Neonatal rat ventricular myocytes (NRVMs) and single-origin human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) and were treated with blood plasma samples from patients with dilated cardiomyopathy (DCM) and donor subjects lacking history of cardiovascular disease. Following plasma treatments, NRVMs and hiPSC-CMs underwent significant hypertrophy relative to non-failing controls, as determined via automated high-content screening. Array-based DNA methylation analysis of plasma-treated hiPSC-CMs and cardiac biopsies uncovered robust, and conserved, alterations in cardiac DNA methylation, from which 100 sites were validated using an independent cohort. Among the CpG sites identified, hypo-methylation of the ATG promoter was identified as a diagnostic marker of HF, wherein cg03800765 methylation (AUC = 0.986, P < 0.0001) was found to out-perform circulating NT-proBNP levels in differentiating heart failure. Taken together, these findings support a novel approach of indirect epigenetic testing in human HF.

Exosomes-Based Nanomedicine for Neurodegenerative Diseases: Current Insights and Future Challenges

Neurodegenerative diseases constitute a group of pathologies whose etiology remains unknown in many cases, and there are no treatments that stop the progression of such diseases. Moreover, the existence of the blood-brain barrier is an impediment to the penetration of exogenous molecules, including those found in many drugs. Exosomes are extracellular vesicles secreted by a wide variety of cells, and their primary functions include intercellular communication, immune responses, human reproduction, and synaptic plasticity. Due to their natural origin and molecular similarities with most cell types, exosomes have emerged as promising therapeutic tools for numerous diseases. Specifically, neurodegenerative diseases have shown to be a potential target for this nanomedicine strategy due to the difficult access to the brain and the strategy's pathophysiological complexity. In this regard, this review explores the most important biological-origin drug delivery systems, innovative isolation methods of exosomes, their physicochemical characterization, drug loading, cutting-edge functionalization strategies to target them within the brain, the latest research studies in neurodegenerative diseases, and the future challenges of exosomes as nanomedicine-based therapeutic tools.

Exosomes mediated fibrogenesis in dilated cardiomyopathy through a MicroRNA pathway

Cardiac fibrosis is a hallmark in late-stage familial dilated cardiomyopathy (DCM) patients, although the underlying mechanism remains elusive. Cardiac exosomes (Exos) have been reported relating to fibrosis in ischemic cardiomyopathy. Thus, we investigated whether Exos secreted from the familial DCM cardiomyocytes could promote fibrogenesis. Using human iPSCs differentiated cardiomyocytes we isolated Exos of angiotensin II stimulation conditioned media from either DCM or control (CTL) cardiomyocytes. Of interest, cultured cardiac fibroblasts had increased fibrogenesis following exposure to DCM-Exos rather than CTL-Exos. Meanwhile, injecting DCM-Exos into mouse hearts enhanced cardiac fibrosis and impaired cardiac function. Mechanistically, we identified the upregulation of miRNA-218-5p in the DCM-Exos as a critical contributor to fibrogenesis. MiRNA-218-5p activated TGF-β signaling via suppression of TNFAIP3, a master inflammation inhibitor. In conclusion, our results illustrate a profibrotic effect of cardiomyocytes-derived Exos that highlights an additional pathogenesis pathway for cardiac fibrosis in DCM.

Extracellular vesicles, the emerging mirrors of brain physiopathology

Extracellular vesicles are secreted by a wide variety of cells, and their primary functions include intercellular communication, immune responses, human reproduction, and synaptic plasticity. Their molecular cargo reflects the physiological processes that their cells of origin are undergoing. Thus, many studies have suggested that extracellular vesicles could be a promising biomarker tool for many diseases, mainly due to their biological relevance and easy accessibility to a broad range of body fluids. Moreover, since their biological composition leads them to cross the blood-brain barrier bidirectionally, growing evidence points to extracellular vesicles as emerging mirrors of brain diseases processes. In this regard, this review explores the biogenesis and biological functions of extracellular vesicles, their role in different physiological and pathological processes, their potential in clinical practice, and the recent outstanding studies about the role of exosomes in major human brain diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), or brain tumors.

Extracellular Vesicles in Amyotrophic Lateral Sclerosis

Amyotrophic Lateral Sclerosis is a progressive neurodegenerative disease and is the most common adult motor neuron disease. The disease pathogenesis is complex with the perturbation of multiple pathways proposed, including mitochondrial dysfunction, RNA processing, glutamate excitotoxicity, endoplasmic reticulum stress, protein homeostasis and endosomal transport/extracellular vesicle (EV) secretion. EVs are nanoscopic membrane-bound particles that are released from cells, involved in the intercellular communication of proteins, lipids and genetic material, and there is increasing evidence of their role in ALS. After discussing the biogenesis of EVs, we review their roles in the propagation of pathological proteins in ALS, such as TDP-43, SOD1 and FUS, and their contribution to disease pathology. We also discuss the ALS related genes which are involved in EV formation and vesicular trafficking, before considering the EV protein and RNA dysregulation found in ALS and how these have been investigated as potential biomarkers. Finally, we highlight the potential use of EVs as therapeutic agents in ALS, in particular EVs derived from mesenchymal stem cells and EVs as drug delivery vectors for potential treatment strategies.

Immune and inflammatory mechanisms of abdominal aortic aneurysm

Abdominal aortic aneurysm (AAA) is a life-threatening cardiovascular disease. Immune-mediated infiltration and a destruction of the aortic wall during AAA development plays significant role in the pathogenesis of this disease. While various immune cells had been found in AAA, the mechanisms of their activation and function are still far from being understood. A better understanding of mechanisms regulating the development of aberrant immune cell activation in AAA is essential for the development of novel preventive and therapeutic approaches. In this review we summarize current knowledge about the role of immune cells in AAA and discuss how pathogenic immune cell activation is regulated in this disease.

Limb-Bud and Heart (LBH) Upregulation in Cardiomyocytes under Hypoxia Promotes the Activation of Cardiac Fibroblasts via Exosome Secretion

The activation of cardiac fibroblasts (CFs) after myocardial infarction (MI) is essential for post-MI infarct healing, during which the regulation of transforming growth factor beta1 (TGF-β1) signaling is predominant. We have demonstrated that TGF-β1-mediated upregulation of LBH contributes to post-MI CF activation via modulating αB-crystallin (CRYAB), after being upregulated by TGF-β1. In this study, the effect of LBH-CRYAB signaling on the cardiac microenvironment via exosome communication and the corresponding mechanisms were investigated. The upregulation of LBH and CRYAB was verified in both cardiomyocytes (CMs) and CFs in hypoxic, post-MI peri-infarct tissues. CM-derived exosomes were isolated and identified, and LBH distribution was elevated in exosomes derived from LBH-upregulated CMs under hypoxia. Treatment with LBH+ exosomes promoted cellular proliferation, differentiation, and epithelial-mesenchymal transition-like processes in CFs. Additionally, in primary LBH^KO CFs, western blotting showed that LBH knockout partially inhibited TGF-β1-induced CF activation, while LBH-CRYAB signaling affected TGF-β1 expression and secretion through a positive feedback loop. The administration of a Smad3 phosphorylation inhibitor to LBH^KO CFs under TGF-β1 stimulation indicated that Smad3 phosphorylation partially accounted for TGF-β1-induced LBH upregulation. In conclusion, LBH upregulation in CMs in post-MI peri-infarct areas correlated with a hypoxic cardiac microenvironment and led to elevated exosomal LBH levels, promoting the activation of recipient CFs, which brings new insights into the studies and therapeutic strategies of post-MI cardiac repair.

The Big Potential of Small Particles: Lipid-Based Nanoparticles and Exosomes in Vaccination

Some of the most significant medical achievements in recent history are the development of distinct and effective vaccines, and the improvement of the efficacy of previously existing ones, which have contributed to the eradication of many dangerous and life-threatening diseases. Immunization depends on the generation of a physiological memory response and protection against infection. It is therefore crucial that antigens are delivered in an efficient manner, to elicit a robust immune response. The recent approval of COVID-19 vaccines containing lipid nanoparticles encapsulating mRNA demonstrates the broad potential of lipid-based delivery systems. In light of this, the present review article summarizes currently synthesized lipid-based nanoparticles such as liposomes, lipid-nano particles, or cell-derived exosomes.

Extracellular Vesicles in Cardiovascular Diseases: Diagnosis and Therapy

Cardiovascular diseases (CVDs) are the leading cause of global mortality. Therapy of CVDs is still a great challenge since many advanced therapies have been developed. Multiple cell types produce nano-sized extracellular vesicles (EVs), including cardiovascular system-related cells and stem cells. Compelling evidence reveals that EVs are associated with the pathophysiological processes of CVDs. Recently researches focus on the clinical transformation in EVs-based diagnosis, prognosis, therapies, and drug delivery systems. In this review, we firstly discuss the current knowledge about the biophysical properties and biological components of EVs. Secondly, we will focus on the functions of EVs on CVDs, and outline the latest advances of EVs as prognostic and diagnostic biomarkers, and therapeutic agents. Finally, we will introduce the specific application of EVs as a novel drug delivery system and its application in CVDs therapy. Specific attention will be paid to summarize the perspectives, challenges, and applications on EVs’ clinical and industrial transformation.

Non-Exosomal and Exosome-Derived miRNAs as Promising Biomarkers in Canine Mammary Cancer

Canine mammary cancer (CMC), similar to human breast cancer (HBC) in many aspects, is the most common neoplasm associated with significant mortality in female dogs. Due to the limited therapy options, biomarkers are highly desirable for early clinical diagnosis or cancer progression monitoring. Since the discovery of microRNAs (miRNAs or miRs) as post-transcriptional gene regulators, they have become attractive biomarkers in oncological research. Except for intracellular miRNAs and cell-free miRNAs, exosome-derived miRNAs (exomiRs) have drawn much attention in recent years as biomarkers for cancer detection. Analysis of exosomes represents a non-invasive, pain-free, time- and money-saving alternative to conventional tissue biopsy. The purpose of this review is to provide a summary of miRNAs that come from non-exosomal sources (canine mammary tumor, mammary tumor cell lines or canine blood serum) and from exosomes as promising biomarkers of CMC based on the current literature. As is discussed, some of the miRNAs postulated as diagnostic or prognostic biomarkers in CMC were also altered in HBC (such as miR-21, miR-29b, miR-141, miR-429, miR-200c, miR-497, miR-210, miR-96, miR-18a, miR19b, miR-20b, miR-93, miR-101, miR-105a, miR-130a, miR-200c, miR-340, miR-486), which may be considered as potential disease-specific biomarkers in both CMC and HBC.