Cardiac fibroblast-derived microRNA passenger strand-enriched exosomes mediate cardiomyocyte hypertrophy

Exosomes based strategies for cardiovascular diseases: Opportunities and challenges

Exosomes, as nanoscale extracellular vesicles (EVs), are secreted by all types of cells to facilitate intercellular communication in living organisms. After being taken up by neighboring or distant cells, exosomes can alter the expression levels of target genes in recipient cells and thereby affect their pathophysiological outcomes depending on payloads encapsulated therein. The functions and mechanisms of exosomes in cardiovascular diseases have attracted much attention in recent years and are thought to have cardioprotective and regenerative potential. This review summarizes the biogenesis and molecular contents of exosomes and details the roles played by exosomes released from various cells in the progression and recovery of cardiovascular disease. The review also discusses the current status of traditional exosomes in cardiovascular tissue engineering and regenerative medicine, pointing out several limitations in their application. It emphasizes that some of the existing emerging industrial or bioengineering technologies are promising to compensate for these shortcomings, and the combined application of exosomes and biomaterials provides an opportunity for mutual enhancement of their performance. The integration of exosome-based cell-free diagnostic and therapeutic options will contribute to the further development of cardiovascular regenerative medicine.

Nicotine Treatment Ameliorates Blood-Brain Barrier Damage After Acute Ischemic Stroke by Regulating Endothelial Scaffolding Protein Pdlim5

Analysis of a National Institutes of Health (NIH) trial shows that cigarette smoking protected tissue plasminogen activator (tPA)-treated patients from hemorrhage transformation (HT); however, the underlying mechanism is not clear. Damage to the integrity of the blood-brain barrier (BBB) is the pathological basis of HT. Here, we investigated the molecular events of BBB damage after acute ischemic stroke (AIS) using in vitro oxygen-glucose deprivation (OGD) and in vivo mice middle cerebral artery occlusion (MCAO) models. Our results showed that the permeability of bEND.3 monolayer endothelial cells was significantly increased after being exposed to OGD for 2 h. Mice were subjected to 90-min ischemia with 45-min reperfusion, and BBB integrity was significantly damaged, accompanied by tight junction protein occludin degradation, downregulation of microRNA-21 (miR-21), transforming growth factor-β (TGF-β), phosphorylated Smad (p-Smad), plasminogen activator inhibitor-1 (PAI-1), and the upregulation of PDZ and LIM domain protein 5 (Pdlim5), an adaptor protein that has been shown to regulate TGF-β-Smad3 pathway. In addition, pretreatment with two-week nicotine significantly reduced AIS-induced BBB damage and its associated protein dysregulation via downregulating Pdlim5. Notably, AIS did not significantly induce BBB damage in Pdlim5 deficit mice, but overexpression of Pdlim5 in the striatum with adeno-associated virus produced BBB damage and associated protein dysregulation which could be ameliorated by two-week nicotine pretreatment. More important, AIS induced a significant miR-21 decrease, and miR-21 mimics treatment decreased AIS-induced BBB damage by decreasing Pdlim5. Together, these results demonstrate that nicotine treatment alleviates the AIS-compromised integrity of BBB by regulating Pdlim5.

Paediatrics congenital heart disease is associated with plasma miRNAs

BACKGROUND

Congenital heart disease (CHD) are the most common malformations from birth. The severity of the different forms of CHD varies extensively from superficial mild lesions with follow-up for decades without any treatment to complex cyanotic malformations requiring urgent surgical intervention. microRNAs have been found to be crucial in cardiac development, giving rise to possible phenotypes in CHD.

OBJECTIVES

We aimed to evaluate the expression of miRNAs in 86 children with CHD and divided into cyanotic and non-cyanotic heart defects and 110 controls.

METHODS

The miRNAs expression of miR-21-5p, miR-155-5p, miR-221-3p, miR-26a-5p, and miR-144-3p were analyzed by RT-qPCR. In addition, the expressions of the miRNAs studied were correlated with the clinical characteristics of both the children and the mothers.

RESULTS

The expression levels of miR-21-5-5p, miR-15-5p5, miR-221-3p, and miR-26-5p significantly differed between CHD and control subjects. Moreover, miR-21-5p levels were higher in patients with cyanotic versus non-cyanotic CHD patients.

CONCLUSION

The expression levels of miRNAs of pediatric patients with CHD could participating in the development of cardiac malformations. Additionally, the high expression of miR-21-5p in cyanotic CHD children may be related to greater severity of illness relative to non-cyanotic CHD.

IMPACT

This study adds to knowledge of the association between microRNAs and congenital heart disease in children. The expression levels of miR-21-5-5p, miR-15-5p5, miR-221-3p, and miR-26-5p of pediatric patients with CHD could be involved in the development and phenotype present in pediatric patients. miR-21-5p may help to discriminate between cyanotic and non-cyanotic CHD. In the future, the miRNAs studied could have applications as clinical biomarkers.

M2 Microglial Extracellular Vesicles Attenuated Blood-brain Barrier Disruption via MiR-23a-5p in Cerebral Ischemic Mice

Protecting the integrity of the blood-brain barrier (BBB) is crucial for maintaining brain homeostasis after ischemic stroke. Previous studies showed that M2 microglial extracellular vesicles (EVs) played a neuroprotective role in cerebral ischemia. However, the role of M2 microglial EVs in maintaining BBB integrity is unclear. Therefore, we explored the mechanisms of M2 microglial EVs in regulating BBB integrity. To identify microglial EVs, we used nanoparticle tracking analysis, transmission electron microscopy, and western blot analysis. Adult male ICR mice were subjected to 90-min middle cerebral artery occlusion (MCAO), followed by the injection of PKH26-labeled M2 microglial EVs via the tail vein. After MCAO, we assessed brain infarct and edema volume, as well as modified neurological severity score. BBB integrity was measured by assessing IgG leakage. The effects of M2 microglial EVs on astrocytes and endothelial cells were also examined. To investigate the molecular mechanisms, we performed RNA sequencing, miR-23a-5p knockdown, and luciferase reporter assays. Our results showed that PKH26-labeled microglial EVs were mainly taken up by neurons and glial cells. M2 microglial EVs treatment decreased brain infarct and edema volume, modified neurological severity score, and IgG leakage, while increasing the ZO-1, occludin, and claudin-5 expression after MCAO. Knockdown of miR-23a-5p reversed these effects. RNA sequencing revealed that the TNF, MMP3 and NFκB signaling pathway involved in regulating BBB integrity. Luciferase reporter assay showed that miR-23a-5p could bind to the 3' UTR of TNF. M2 microglial EVs-derived miR-23a-5p decreased TNF, MMP3 and NFκB p65 expression in astrocytes after oxygen-glucose deprivation, thereby increasing ZO-1 and Claudin-5 expression in bEnd.3 cells. In conclusion, our findings demonstrated that M2 microglial EVs attenuated BBB disruption after cerebral ischemia by delivering miR-23a-5p, which targeted TNF and regulated MMP3 and NFκB p65 expression.

Essential role of Alix in regulating cardiomyocyte exosome biogenesis under physiological and stress conditions

BACKGROUND

Exosomes released by cardiomyocytes are essential mediators of intercellular communications within the heart, and various exosomal proteins and miRNAs are associated with cardiovascular diseases. However, whether the endosomal sorting complex required for transport (ESCRT) and its key component Alix is required for exosome biogenesis within cardiomyocyte remains poorly understood.

METHODS

Super-resolution imaging was performed to investigate the subcellular location of Alix and multivesicular body (MVB) in primary cardiomyocytes. Cardiomyocyte-specific Alix-knockout mice were generated using AAV9/CRISPR/Cas9-mediated in vivo gene editing. A stable Alix-knockdown H9c2 cardiomyocyte line was constructed through lentiviral-mediated delivery of short hairpin RNA. In order to determine the role of Alix in controlling exosome biogenesis, exosomes from cardiomyocyte-specific Alix-knockout mice plasma and Alix-knockdown H9c2 culture medium were isolated and examined by western blot, NTA analysis and transmission electron microscopy. Biochemical and immunofluorescence analysis were performed to determine the role of ESCRT machinery in regulating MVB formation. Lastly, transverse aortic constriction (TAC)-induced cardiac pressure overload model was established to further explore the role of Alix-mediated exosome biogenesis under stress conditions.

RESULTS

A significant proportion of Alix localized to the MVB membrane within cardiomyocytes. Genetic deletion of Alix in murine heart resulted in a reduction of plasma exosome content without affecting cardiac structure or contractile function. Consistently, the downregulation of Alix in H9c2 cardiomyocyte line also suppressed the biogenesis of exosomes. We found the defective ESCRT machinery and suppressed MVB formation upon Alix depletion caused compromised exosome biogenesis. Remarkably, TAC-induced cardiac pressure overload led to increased Alix, MVB levels, and elevated plasma exosome content, which could be totally abolished by Alix deletion.

CONCLUSION

These results establish Alix as an essential and stress-sensitive regulator of cardiac exosome biogenesis and the findings may yield valuable therapeutic implications.

The role of cardiac microenvironment in cardiovascular diseases: implications for therapy

Due to aging populations and changes in lifestyle, cardiovascular diseases including cardiomyopathy, hypertension, and atherosclerosis, are the leading causes of death worldwide. The heart is a complicated organ composed of multicellular types, including cardiomyocytes, fibroblasts, endothelial cells, vascular smooth muscle cells, and immune cells. Cellular specialization and complex interplay between different cell types are crucial for the cardiac tissue homeostasis and coordinated function of the heart. Mounting studies have demonstrated that dysfunctional cells and disordered cardiac microenvironment are closely associated with the pathogenesis of various cardiovascular diseases. In this paper, we discuss the composition and the homeostasis of cardiac tissues, and focus on the role of cardiac environment and underlying molecular mechanisms in various cardiovascular diseases. Besides, we elucidate the novel treatment for cardiovascular diseases, including stem cell therapy and targeted therapy. Clarification of these issues may provide novel insights into the prevention and potential targets for cardiovascular diseases.

Progress in extracellular vesicle homeostasis as it relates to cardiovascular diseases

Extracellular vesicles (EVs) are involved in both physiological and pathological processes in many organ systems and are essential in mediating intercellular communication and maintaining organismal homeostasis. It is helpful to propose new strategies for disease treatment by elucidating the mechanisms of EV release and sorting. An increasing number of studies have shown that there is specific homeostasis in EVs, which is helpful for the human body to carry out physiological activities. In contrast, an EV homeostasis im-balance promotes or accelerates disease onset and development. Alternatively, regulating the quality of EVs can maintain homeostasis and even achieve the purpose of treating conditions. An analysis of the role of EV homeostasis in the onset and development of cardiovascular disease is presented in this review. This article also summarizes the methods that regulate EV homeostasis and their application in cardiovascular diseases. In particular, this study focuses on the connection between EV steady states and the cardiovascular system and the potential value of EVs in treating cardiovascular diseases.

The potential roles of exosomes in pathological cardiomyocyte hypertrophy mechanisms and therapy: A review

Pathological cardiac hypertrophy, characterized by the enlargement of cardiac muscle cells, leads to serious cardiac conditions and stands as a major global health issue. Exosomes, comprising small lipid bilayer vesicles, are produced by various cell types and found in numerous bodily fluids. They play a pivotal role in intercellular communication by transferring bioactive cargos to recipient cells or activating signaling pathways in target cells. Exosomes from cardiomyocytes, endothelial cells, fibroblasts, and stem cells are key in regulating processes like cardiac hypertrophy, cardiomyocyte survival, apoptosis, fibrosis, and angiogenesis within the context of cardiovascular diseases. This review delves into exosomes' roles in pathological cardiac hypertrophy, first elucidating their impact on cell communication and signaling pathways. It then advances to discuss how exosomes affect key hypertrophic processes, including metabolism, fibrosis, oxidative stress, and angiogenesis. The review culminates by evaluating the potential of exosomes as biomarkers and their significance in targeted therapeutic strategies, thus emphasizing their critical role in the pathophysiology and management of cardiac hypertrophy.

Biomarkers of chemotherapy-induced cardiotoxicity: toward precision prevention using extracellular vesicles

Detrimental side effects of drugs like doxorubicin, which can cause cardiotoxicity, pose barriers for preventing cancer progression, or treating cancer early through molecular interception. Extracellular vesicles (EVs) are valued for their potential as biomarkers of human health, chemical and molecular carcinogenesis, and therapeutics to treat disease at the cellular level. EVs are released both during normal growth and in response to toxicity and cellular death, playing key roles in cellular communication. Consequently, EVs may hold promise as precision biomarkers and therapeutics to prevent or offset damaging off-target effects of chemotherapeutics. EVs have promise as biomarkers of impending cardiotoxicity induced by chemotherapies and as cardioprotective therapeutic agents. However, EVs can also mediate cardiotoxic cues, depending on the identity and past events of their parent cells. Understanding how EVs mediate signaling is critical toward implementing EVs as therapeutic agents to mitigate cardiotoxic effects of chemotherapies. For example, it remains unclear how mixtures of EV populations from cells exposed to toxins or undergoing different stages of cell death contribute to signaling across cardiac tissues. Here, we present our perspective on the outlook of EVs as future clinical tools to mitigate chemotherapy-induced cardiotoxicity, both as biomarkers of impending cardiotoxicity and as cardioprotective agents. Also, we discuss how heterogeneous mixtures of EVs and transient exposures to toxicants may add complexity to predicting outcomes of exogenously applied EVs. Elucidating how EV cargo and signaling properties change during dynamic cellular events may aid precision prevention of cardiotoxicity in anticancer treatments and development of safer chemotherapeutics.

Exosome-loaded decellularized tissue: Opening a new window for regenerative medicine

Mesenchymal stem cell-derived exosomes (MSCs-EXO) have received a lot of interest recently as a potential therapeutic tool in regenerative medicine. Extracellular vesicles (EVs) known as exosomes (EXOs) are crucial for cell-cell communication throughout a variety of activities including stress response, aging, angiogenesis, and cell differentiation. Exploration of the potential use of EXOs as essential therapeutic effectors of MSCs to encourage tissue regeneration was motivated by success in the field of regenerative medicine. EXOs have been administered to target tissues using a variety of methods, including direct, intravenous, intraperitoneal injection, oral delivery, and hydrogel-based encapsulation, in various disease models. Despite the significant advances in EXO therapy, various methods are still being researched to optimize the therapeutic applications of these nanoparticles, and it is not completely clear which approach to EXO administration will have the greatest effects. Here, we will review emerging developments in the applications of EXOs loaded into decellularized tissues as therapeutic agents for use in regenerative medicine in various tissues.

Exosomes: current knowledge and future perspectives

Exosomes are membrane-bound micro-vesicles that possess endless therapeutic potential for treatment of numerous pathologies including autoimmune, cardiovascular, ocular, and nervous disorders. Despite considerable knowledge about exosome biogenesis and secretion, still, there is a lack of information regarding exosome uptake by cell types and internal signaling pathways through which these exosomes process cellular response. Exosomes are key components of cell signaling and intercellular communication. In central nervous system (CNS), exosomes can penetrate BBB and maintain homeostasis by myelin sheath regulation and the waste products elimination. Therefore, the current review summarizes role of exosomes and their use as biomarkers in cardiovascular, nervous and ocular disorders. This aspect of exosomes provides positive hope to monitor disease development and enable early diagnosis and treatment optimization. In this review, we have summarized recent findings on physiological and therapeutic effects of exosomes and also attempt to provide insights about stress-preconditioned exosomes and stem cell-derived exosomes.

Probiotics, gut microbiome, and cardiovascular diseases: An update

Cardiovascular diseases (CVD) are one of the most challenging diseases and many factors have been demonstrated to affect their pathogenesis. One of the major factors that affect CVDs, especially atherosclerosis, is the gut microbiota (GM). Genetics play a key role in linking CVDs with GM, in addition to some environmental factors which can be either beneficial or harmful. The interplay between GM and CVDs is complex due to the numerous mechanisms through which microbial components and their metabolites can influence CVDs. Within this interplay, the immune system plays a major role, mainly based on the immunomodulatory effects of microbial dysbiosis and its resulting metabolites. The resulting modulation of chronic inflammatory processes was found to reduce the severity of CVDs and to maintain cardiovascular health. To better understand the specific roles of GM-related metabolites in this interplay, this review presents an updated perspective on gut metabolites related effects on the cardiovascular system, highlighting the possible benefits of probiotics in therapeutic strategies.

Methods, Mechanisms, and Application Prospects for Enhancing Extracellular Vesicle Uptake

Extracellular vesicles (EVs) are considered to be a new generation of bioinspired nanoscale drug delivery systems due to their low immunogenicity, natural functionality, and excellent biocompatibility. However, limitations such as low uptake efficiency, insufficient production, and inhomogeneous performance undermine their potential. To address these issues, numerous researchers have put forward various methods and applications for enhancing EV uptake in recent decades. In this review, we introduce various methods for the cellular uptake of EVs and summarize recent advances on the methods and mechanisms for enhancing EV uptake. In addition, we provide further understanding regarding enhancing EV uptake and put forward prospects and challenges for the development of EV-based therapy in the future.

Biomimetic nanomaterials in myocardial infarction treatment: Harnessing bionic strategies for advanced therapeutics

Myocardial infarction (MI) and its associated poor prognosis pose significant risks to human health. Nanomaterials hold great potential for the treatment of MI due to their targeted and controlled release properties, particularly biomimetic nanomaterials. The utilization of biomimetic strategies based on extracellular vesicles (EVs) and cell membranes will serve as the guiding principle for the development of nanomaterial therapy in the future. In this review, we present an overview of research progress on various exosomes derived from mesenchymal stem cells, cardiomyocytes, or induced pluripotent stem cells in the context of myocardial infarction (MI) therapy. These exosomes, utilized as cell-free therapies, have demonstrated the ability to enhance the efficacy of reducing the size of the infarcted area and preventing ischaemic reperfusion through mechanisms such as oxidative stress reduction, polarization modulation, fibrosis inhibition, and angiogenesis promotion. Moreover, EVs can exert cardioprotective effects by encapsulating therapeutic agents and can be engineered to specifically target the infarcted myocardium. Furthermore, we discuss the use of cell membranes derived from erythrocytes, stem cells, immune cells and platelets to encapsulate nanomaterials. This approach allows the nanomaterials to camouflage themselves as endogenous substances targeting the region affected by MI, thereby minimizing toxicity and improving biocompatibility. In conclusion, biomimetic nano-delivery systems hold promise as a potentially beneficial technology for MI treatment. This review serves as a valuable reference for the application of biomimetic nanomaterials in MI therapy and aims to expedite the translation of NPs-based MI therapeutic strategies into practical clinical applications.

Non-Coding RNA-Targeted Therapy: A State-of-the-Art Review

The use of non-coding RNAs (ncRNAs) as drug targets is being researched due to their discovery and their role in disease. Targeting ncRNAs, including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), is an attractive approach for treating various diseases, such as cardiovascular disease and cancer. This seminar discusses the current status of ncRNAs as therapeutic targets in different pathological conditions. Regarding miRNA-based drugs, this approach has made significant progress in preclinical and clinical testing for cardiovascular diseases, where the limitations of conventional pharmacotherapy are evident. The challenges of miRNA-based drugs, including specificity, delivery, and tolerability, will be discussed. New approaches to improve their success will be explored. Furthermore, it extensively discusses the potential development of targeted therapies for cardiovascular disease. Finally, this document reports on the recent advances in identifying and characterizing microRNAs, manipulating them, and translating them into clinical applications. It also addresses the challenges and perspectives towards clinical application.

Non-coding RNAs as therapeutic targets and biomarkers in ischaemic heart disease

The adult heart is a complex, multicellular organ that is subjected to a series of regulatory stimuli and circuits and has poor reparative potential. Despite progress in our understanding of disease mechanisms and in the quality of health care, ischaemic heart disease remains the leading cause of death globally, owing to adverse cardiac remodelling, leading to ischaemic cardiomyopathy and heart failure. Therapeutic targets are urgently required for the protection and repair of the ischaemic heart. Moreover, personalized clinical biomarkers are necessary for clinical diagnosis, medical management and to inform the individual response to treatment. Non-coding RNAs (ncRNAs) deeply influence cardiovascular functions and contribute to communication between cells in the cardiac microenvironment and between the heart and other organs. As such, ncRNAs are candidates for translation into clinical practice. However, ncRNA biology has not yet been completely deciphered, given that classes and modes of action have emerged only in the past 5 years. In this Review, we discuss the latest discoveries from basic research on ncRNAs and highlight both the clinical value and the challenges underscoring the translation of these molecules as biomarkers and therapeutic regulators of the processes contributing to the initiation, progression and potentially the prevention or resolution of ischaemic heart disease and heart failure.

Forward genetic screen using a gene-breaking trap approach identifies a novel role of grin2bb-associated RNA transcript (grin2bbART) in zebrafish heart function

LncRNA-based control affects cardiac pathophysiologies like myocardial infarction, coronary artery disease, hypertrophy, and myotonic muscular dystrophy. This study used a gene-break transposon (GBT) to screen zebrafish (Danio rerio) for insertional mutagenesis. We identified three insertional mutants where the GBT captured a cardiac gene. One of the adult viable GBT mutants had bradycardia (heart arrhythmia) and enlarged cardiac chambers or hypertrophy; we named it "bigheart." Bigheart mutant insertion maps to grin2bb or N-methyl D-aspartate receptor (NMDAR2B) gene intron 2 in reverse orientation. Rapid amplification of adjacent cDNA ends analysis suggested a new insertion site transcript in the intron 2 of grin2bb. Analysis of the RNA sequencing of wild-type zebrafish heart chambers revealed a possible new transcript at the insertion site. As this putative lncRNA transcript satisfies the canonical signatures, we called this transcript grin2bb associated RNA transcript (grin2bbART). Using in situ hybridization, we confirmed localized grin2bbART expression in the heart, central nervous system, and muscles in the developing embryos and wild-type adult zebrafish atrium and bulbus arteriosus. The bigheart mutant had reduced Grin2bbART expression. We showed that bigheart gene trap insertion excision reversed cardiac-specific arrhythmia and atrial hypertrophy and restored grin2bbART expression. Morpholino-mediated antisense downregulation of grin2bbART in wild-type zebrafish embryos mimicked bigheart mutants; this suggests grin2bbART is linked to bigheart. Cardiovascular tissues use Grin2bb as a calcium-permeable ion channel. Calcium imaging experiments performed on bigheart mutants indicated calcium mishandling in the heart. The bigheart cardiac transcriptome showed differential expression of calcium homeostasis, cardiac remodeling, and contraction genes. Western blot analysis highlighted Camk2d1 and Hdac1 overexpression. We propose that altered calcium activity due to disruption of grin2bbART, a putative lncRNA in bigheart, altered the Camk2d-Hdac pathway, causing heart arrhythmia and hypertrophy in zebrafish.

Recent advances on the Role of Gut Microbiota in the Development of Heart Failure by Mediating Immune Metabolism

The association between gut microbiota and the development of heart failure has become a research hotspot in recent years and the impact of gut microbiota on heart failure has attracted growing interest. From 2006 to 2021, the global research on gut microbiota and heart failure has gradually expanded, indicating a developed and promising research field. There were 40 countries, 196 institutions, and 257 authors involved in the publication on the relationship between gut microbiota and heart failure, respectively. In patients with heart failure, inadequate visceral perfusion leads to ischemia and intestinal edema, which compromise the gut barrier. This subsequently results in the translocation of bacteria and bacterial metabolites into the circulatory system and causes local and systemic inflammatory responses. The gastrointestinal tract contains the largest number of immune cells in the human body and gut microbiota play important roles in the immune system by promoting immune tolerance to symbiotic bacteria. Studies have shown that probiotics can act on gut microorganisms, thereby increasing choline metabolism and reducing plasma TMA and TMAO concentrations, thus inhibiting the development of heart failure. Meanwhile, probiotics induce the production of inflammatory suppressors to maintain gut immune stability and inhibit the progression of heart failure by reducing ventricular remodeling. Here, we review the current understanding of gut microbiota-driven immune dysfunction in experimental and clinical heart failure, as well as the therapeutic interventions that could be used to address these issues.

Predictive biomarkers for the early detection and management of heart failure

Cardiovascular disease (CVD) is a serious public health concern whose incidence has been on a rise and is projected by the World Health Organization to be the leading global cause of mortality by 2030. Heart failure (HF) is a complicated syndrome resulting from various CVDs of heterogeneous etiologies and exhibits varying pathophysiology, including activation of inflammatory signaling cascade, apoptosis, fibrotic pathway, and neuro-humoral system, thereby leading to compromised cardiac function. During this process, several biomolecules involved in the onset and progression of HF are released into circulation. These circulating biomolecules could serve as unique biomarkers for the detection of subclinical changes and can be utilized for monitoring disease severity. Hence, it is imperative to identify these biomarkers to devise an early predictive strategy to stop the deterioration of cardiac function caused by these complex cellular events. Furthermore, measurement of multiple biomarkers allows clinicians to divide HF patients into sub-groups for treatment and management based on early health outcomes. The present article provides a comprehensive overview of current omics platform available for discovering biomarkers for HF management. Some of the existing and novel biomarkers for the early detection of HF with special reference to endothelial biology are also discussed.

Extracellular vesicles in heart failure

Physiologically, extracellular vesicles (EVs) have been implicated as crucial mediators of immune response, cell homeostasis, angiogenesis, cell differentiation and growth, and tissue repair. In heart failure (HF) they may act as regulators of cardiac remodeling, microvascular inflammation, micro environmental changes, tissue fibrosis, atherosclerosis, neovascularization of plaques, endothelial dysfunction, thrombosis, and reciprocal heart-remote organ interaction. The chapter summaries the nomenclature, isolation, detection of EVs, their biologic role and function physiologically as well as in the pathogenesis of HF. Current challenges to the utilization of EVs as diagnostic and predictive biomarkers in HF are also discussed.

Exosomal miR206 Secreted From Growing Muscle Promotes Angiogenic Response in Endothelial Cells

BACKGROUND

Resistance exercise is beneficial in patients with lower extremity arterial disease. Muscle-derived exosomes contain many types of signaling molecules, including microRNAs (miRNAs). Here, we tested the hypothesis that exosomal miRNAs secreted by growing muscles promote an angiogenic response in endothelial cells (ECs).Methods and Results: Skeletal muscle-specific conditional Akt1 transgenic (Akt1-TG) mice, in which skeletal muscle growth can be induced were used as a model of resistance training. Remarkable skeletal muscle growth was observed in mice 2 weeks after gene activation. The protein amount in exosomes secreted by growing muscles did not differ between Akt1-TG and control mice. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway frequency analysis of 4,665 target genes, identified using an miRNA array miRNAs, revealed a significant increase in Akt and its downstream signaling pathway genes. Among the upregulated miRNAs, miR1, miR133, and miR206 were significantly upregulated in the serum of Akt1-TG mice. miR206 was also increased in insulin-like growth factor (IGF)-1-stimulated hypertrophied myotubes. Exogenous supplementation of exosomal miR206 to human umbilical vein ECs promoted angiogenesis, as assessed using the spheroid assay, and increased the expression of angiogenesis-related transcripts.

CONCLUSIONS

Exosomal miR206 is upregulated in the blood of Akt1-TG mice and in IGF-stimulated cultured myotubes. Exogenous supplementation of miR206 promoted an angiogenic response in ECs. Our data suggest that miR206 secreted from growing muscles acts on ECs and promotes angiogenesis.

M2 macrophage-derived exosomal miR-26b-5p regulates macrophage polarization and chondrocyte hypertrophy by targeting TLR3 and COL10A1 to alleviate osteoarthritis

Osteoarthritis (OA) is one of the most prevalent chronic musculoskeletal diseases among the elderly population. In this study, macrophage-derived exosomes were isolated and identified. Exosomes were subjected to microRNA (miRNA) sequencing and bioinformatic analysis, and differentially expressed miRNAs were verified. miR-26b-5p target genes were confirmed through target-site mutation combined with a dual-luciferase reporter assay. The effects of miR-26b-5p on macrophage polarization and chondrocyte hypertrophy were assessed in vitro. miR-26b-5p agomir was applied to mice with OA induced by anterior cruciate ligament transection (ACLT). The therapeutic effects of miR-26b-5p were evaluated via pain behavior experiments and histological observations. In vitro, miR-26b-5p repolarized M1 macrophages to an anti-inflammatory M2 type by targeting the TLR3 signaling pathway. miR-26b-5p could target COL10A1, further inhibiting chondrocyte hypertrophy induced by M1 macrophage-conditioned medium (M1-CM). In vivo, miR-26b-5p agomir ameliorated gait abnormalities and mechanical allodynia in OA mice. miR-26b-5p treatment attenuated synovitis and cartilage degeneration, thereby delaying OA progression. In conclusion, M2 macrophage-derived exosomal miR-26b-5p could protect articular cartilage and ameliorate gait abnormalities in OA mice by targeting TLR3 and COL10A1. miR-26b-5p further affected macrophage polarization and chondrocyte hypertrophy. Thus, this exosomal miR-26b-5p-based strategy might be a potential method for OA treatment.

Downregulation of the CD151 protects the cardiac function by the crosstalk between the endothelial cells and cardiomyocytes via exosomes

BACKGROUND

Heart failure (HF) is the last stage in the progression of various cardiovascular diseases. Although it is documented that CD151 contributes to regulate the myocardial infarction, the function of CD151 on HF and involved mechanisms are still unclear.

METHOD AND RESULTS

In the present study, we found that the recombinant adeno-associated virus (rAAV)-mediated endothelial cell-specific knockdown of CD151-transfected mice improved transverse aortic constriction (TAC)-induced cardiac function, attenuated myocardial hypertrophy and fibrosis, and increased coronary perfusion, whereas overexpression of the CD151 protein aggravated cardiac dysfunction and showed the opposite effects. In vitro, the cardiomyocytes hypertrophy induced by PE were significantly improved, while the proliferation and migration of cardiac fibroblasts (CFs) were significantly reduced, when co-cultured with the CD151-silenced endothelial cells (ECs). To further explore the mechanisms, the exosomes from the CD151-silenced ECs were taken by cardiomyocyte (CMs) and CFs, verified the intercellular communication. And the protective effects of CD151-silenced ECs were inhibited when exosome inhibitor (GW4869) was added. Additionally, a quantitative proteomics method was used to identify potential proteins in CD151-silenced EC exosomes. We found that the suppression of CD151 could regulate the PPAR signaling pathway via exosomes.

CONCLUSION

Our observations suggest that the downregulation of CD151 is an important positive regulator of cardiac function of heart failure, which can regulate exosome-stored proteins to play a role in the cellular interaction on the CMs and CFs. Modulating the exosome levels of ECs by reducing CD151 expression may offer novel therapeutic strategies and targets for HF treatment.

Single-cell transcriptomic profiling of heart reveals ANGPTL4 linking fibroblasts and angiogenesis in heart failure with preserved ejection fraction

INTRODUCTION

Despite the high morbidity and mortality, the effective therapies for heart failure with preserved fraction (HFpEF) are limited as the poor understand of its pathophysiological basis.

OBJECTIVE

This study was aimed to characterize the cellular heterogeneity and potential mechanisms of HFpEF at single-cell resolution.

METHODS

An HFpEF mouse model was induced by a high-fat diet with N-nitro-L-arginine methyl ester. Cells from the hearts were subjected to single-cell sequencing. The key protein expression was measured with Immunohistochemistry and immunofluorescence staining.

RESULTS

In HFpEF hearts, myocardial fibroblasts exhibited higher levels of fibrosis. Furthermore, an increased number of fibroblasts differentiated into high-metabolism and high-fibrosis phenotypes. The expression levels of genes encoding certain pro-angiogenic secreted proteins were decreased in the HFpEF group, as confirmed by bulk RNA sequencing. Additionally, the proportion of the endothelial cell (EC) lineages in the HFpEF group was significantly downregulated, with low angiogenesis and high apoptosis phenotypes observed in these EC lineages. Interestingly, the fibroblasts in the HFpEF heart might cross-link with the EC lineages via over-secretion of ANGPTL4, thus displaying an anti-angiogenic function. Immunohistochemistry and immunofluorescence staining then revealed the downregulation of vascular density and upregulation of ANGPTL4 expression in HFpEF hearts. Finally, we predicted ANGPTL4as a potential druggable target using DrugnomeAI.

CONCLUSION

In conclusion, this study comprehensively characterized the angiogenesis impairment in HFpEF hearts at single-cell resolution and proposed that ANGPTL4 secretion by fibroblasts may be a potential mechanism underlying this angiogenic abnormality.

Extracellular vesicles as tools and targets in therapy for diseases

Extracellular vesicles (EVs) are nano-sized, membranous structures secreted into the extracellular space. They exhibit diverse sizes, contents, and surface markers and are ubiquitously released from cells under normal and pathological conditions. Human serum is a rich source of these EVs, though their isolation from serum proteins and non-EV lipid particles poses challenges. These vesicles transport various cellular components such as proteins, mRNAs, miRNAs, DNA, and lipids across distances, influencing numerous physiological and pathological events, including those within the tumor microenvironment (TME). Their pivotal roles in cellular communication make EVs promising candidates for therapeutic agents, drug delivery systems, and disease biomarkers. Especially in cancer diagnostics, EV detection can pave the way for early identification and offers potential as diagnostic biomarkers. Moreover, various EV subtypes are emerging as targeted drug delivery tools, highlighting their potential clinical significance. The need for non-invasive biomarkers to monitor biological processes for diagnostic and therapeutic purposes remains unfulfilled. Tapping into the unique composition of EVs could unlock advanced diagnostic and therapeutic avenues in the future. In this review, we discuss in detail the roles of EVs across various conditions, including cancers (encompassing head and neck, lung, gastric, breast, and hepatocellular carcinoma), neurodegenerative disorders, diabetes, viral infections, autoimmune and renal diseases, emphasizing the potential advancements in molecular diagnostics and drug delivery.

Understanding exosomes: Part 1-Characterization, quantification and isolation techniques

Exosomes are the smallest subset of extracellular signaling vesicles secreted by most cells with a diameter in the range of 30-150 nm. Their use has gained great momentum recently due to their ability to be utilized as diagnostic tools with a vast array of therapeutic applications. Over 5000 publications are currently being published yearly on this topic, and this number is only expected to dramatically increase as novel therapeutic strategies continue to be investigated. This review article first focuses on understanding exosomes, including their cellular origin, biogenesis, function, and characterization. Thereafter, overviews of the quantification methods and isolation techniques are given with discussion over their potential use as novel therapeutics in regenerative medicine.

Programming of cardiac metabolism by miR-15b-5p, a miRNA released in cardiac extracellular vesicles following ischemia-reperfusion injury

OBJECTIVE

We investigated the potential involvement of miRNAs in the developmental programming of cardiovascular diseases (CVD) by maternal obesity.

METHODS

Serum miRNAs were measured in individuals from the Helsinki Birth Cohort (with known maternal body mass index), and a mouse model was used to determine causative effects of maternal obesity during pregnancy and ischemia-reperfusion on offspring cardiac miRNA expression and release.

RESULTS

miR-15b-5p levels were increased in the sera of males born to mothers with higher BMI and in the hearts of adult mice born to obese dams. In an ex-vivo model of perfused mouse hearts, we demonstrated that cardiac tissue releases miR-15b-5p, and that some of the released miR-15b-5p was contained within small extracellular vesicles (EVs). We also demonstrated that release was higher from hearts exposed to maternal obesity following ischaemia/reperfusion. Over-expression of miR-15b-5p in vitro led to loss of outer mitochondrial membrane stability and to repressed fatty acid oxidation in cardiomyocytes.

CONCLUSIONS

These findings suggest that miR-15-b could play a mechanistic role in the dysregulation of cardiac metabolism following exposure to an in utero obesogenic environment and that its release in cardiac EVs following ischaemic damage may be a novel factor contributing to inter-organ communication between the programmed heart and peripheral tissues.

Closer to The Heart: Harnessing the Power of Targeted Extracellular Vesicle Therapies

Extracellular vesicles (EVs) have emerged as novel diagnostic and therapeutic approaches for cardiovascular diseases. EVs derived from various origins exhibit distinct effects on the cardiovascular system. However, the application of native EVs is constrained due to their poor stabilities and limited targeting capabilities. Currently, targeted modification of EVs primarily involves genetic engineering, chemical modification (covalent, non-covalent), cell membrane modification, and biomaterial encapsulation. These techniques enhance the stability, biological activity, target-binding capacity, and controlled release of EVs at specific cells and tissues. The diverse origins of cardioprotective EVs are covered, and the applications of cardiac-targeting EV delivery systems in protecting against cardiovascular diseases are discussed. This review summarizes the current stage of research on the potential of EV-based targeted therapies for addressing cardiovascular disorders.

Exosome regulation of immune response mechanism: Pros and cons in immunotherapy

Due to its multiple features, including the ability to orchestrate remote communication between different tissues, the exosomes are the extracellular vesicles arousing the highest interest in the scientific community. Their size, established as an average of 30-150 nm, allows them to be easily uptaken by most cells. According to the type of cells-derived exosomes, they may carry specific biomolecular cargoes used to reprogram the cells they are interacting with. In certain circumstances, exosomes stimulate the immune response by facilitating or amplifying the release of foreign antigens-killing cells, inflammatory factors, or antibodies (immune activation). Meanwhile, in other cases, they are efficiently used by malignant elements such as cancer cells to mislead the immune recognition mechanism, carrying and transferring their cancerous cargoes to distant healthy cells, thus contributing to antigenic invasion (immune suppression). Exosome dichotomic patterns upon immune system regulation present broad advantages in immunotherapy. Its perfect comprehension, from its early biogenesis to its specific interaction with recipient cells, will promote a significant enhancement of immunotherapy employing molecular biology, nanomedicine, and nanotechnology.

Extracellular vesicles in cardiomyopathies: A narrative review

Extracellular vesicles (EVs) are membrane-bound particles released by all cells under physiological and pathological conditions. EVs constitute a potential tool to unravel cell-specific pathophysiological mechanisms at the root of disease states and retain the potential to act as biomarkers for cardiac diseases. By being able to carry bioactive cargo (such as proteins and miRNAs), EVs harness great potential as accessible "liquid biopsies", given their ability to reflect the state of their cell of origin. Cardiomyopathies encompass a variety of myocardial disorders associated with mechanical, functional and/or electric dysfunction. These diseases exhibit different phenotypes, including inappropriate ventricular hypertrophy, dilatation, scarring, fibro-fatty replacement, dysfunction, and may stem from multiple aetiologies, most often genetic. Thus, the aims of this narrative review are to summarize the current knowledge on EVs and cardiomyopathies (e.g., hypertrophic, dilated and arrhythmogenic), to elucidate the potential role of EVs in the paracrine cell-to-cell communication among cardiac tissue compartments, in aiding the diagnosis of the diverse subtypes of cardiomyopathies in a minimally invasive manner, and finally to address whether certain molecular and phenotypical characteristics of EVs may correlate with cardiomyopathy disease phenotype and severity.

Immunometabolism, extracellular vesicles and cardiac injury

Recent evidence from our lab and others suggests that metabolic reprogramming of immune cells drives changes in immune cell phenotypes along the inflammatory-to-reparative spectrum and plays a critical role in mediating the inflammatory responses to cardiac injury (e.g. hypertension, myocardial infarction). However, the factors that drive metabolic reprogramming in immune cells are not fully understood. Extracellular vesicles (EVs) are recognized for their ability to transfer cargo such as microRNAs from remote sites to influence cardiac remodeling. Furthermore, conditions such as obesity and metabolic syndrome, which are implicated in the majority of cardiovascular disease (CVD) cases, can skew production of EVs toward pro-inflammatory phenotypes. In this mini-review, we discuss the mechanisms by which EVs may influence immune cell metabolism during cardiac injury and factors associated with obesity and the metabolic syndrome that can disrupt normal EV function. We also discuss potential sources of cardio-protective and anti-inflammatory EVs, such as brown adipose tissue. Finally, we discuss implications for future therapeutics.

Extracellular vesicles from normal tissues orchestrate the homeostasis of macrophages and attenuate inflammatory injury of sepsis

Extracellular vesicles (EVs) exist throughout our bodies. We recently revealed the important role of intracardiac EVs induced by myocardial ischemia/reperfusion on cardiac injury and dysfunction. However, the role of EVs isolated from normal tissues remains unclear. Here we found that EVs, derived from murine heart, lung, liver and kidney have similar effects on macrophages and regulate the inflammation, chemotaxis, and phagocytosis of macrophages. Interestingly, EV-treated macrophages showed LPS resistance with reduced expressions of inflammatory cytokines and enhanced phagocytic activity. Furthermore, we demonstrated that the protein content in EVs contributed to the activation of inflammation, while the RNA component mainly limited the excessive inflammatory response of macrophages to LPS. The enrichment of miRNAs, including miR-148a-3p, miR-1a-3p and miR-143-3p was confirmed in tissue EVs. These EV-enriched miRNAs contributed to the inflammation remission in LPS induced macrophages through multiple pathways, including STAT3, P65 and SAPK/JNK. Moreover, administration of both EVs and EV-educated macrophages attenuated septic injury and cytokine storm in murine CLP models. Taken together, the present study disclosed that EVs from normal tissues can orchestrate the homeostasis of macrophages and attenuate inflammatory injury of sepsis. Therefore, tissue derived EVs or their derivatives may serve as potential therapeutic strategies in inflammatory diseases.

Aortic calcification accelerates cardiac dysfunction via inducing apoptosis of cardiomyocytes

Vascular calcification (VC) is a known predictor of cardiovascular events in patients with atherosclerosis and chronic renal disease. However, the exact relationship between VC and cardiovascular mortality remains unclear. Herein, we investigated the underlying mechanisms between VC progression, arterial stiffness, and cardiac dysfunction. C57BL/6 mice were administered intraperitoneally vitamin D3 (VD3) at a dosage of 35×104 IU/day for 14 days. At day 42, VC extent, artery elasticity, carotid artery blood flow, aorta pulse propagation velocity, cardiac function, and pathological changes were evaluated. Heart apoptosis was detected using TUNEL and immunohistochemistry staining. In vitro, rat cardiomyocytes H9C2 were exposed to media from calcified rat vascular smooth muscle cells (VSMCs) cultured in calcification medium, and then H9C2 apoptosis and gene expression related to cardiac function were assessed. VD3-treated mice displayed a significant aortic calcification, increased pulse propagation velocity of aortae, and reduced cardiac function. Aortae showed increased calcification and elastolysis, with increased heart apoptosis. Hearts demonstrated higher levels of ANP, BNP, MMP2, and lower levels of bcl2/bax. Moreover, calcified rat VSMC media induced H9C2 apoptosis and upregulated genes expression linked to cardiac dysfunction. Our data provide evidence that VC accelerates cardiac dysfunction, partially by inducing cardiomyocytes apoptosis.

Single-cell transcriptional landscape of long non-coding RNAs orchestrating mouse heart development

Long non-coding RNAs (lncRNAs) comprise the most representative transcriptional units of the mammalian genome. They are associated with organ development linked with the emergence of cardiovascular diseases. We used bioinformatic approaches, machine learning algorithms, systems biology analyses, and statistical techniques to define co-expression modules linked to heart development and cardiovascular diseases. We also uncovered differentially expressed transcripts in subpopulations of cardiomyocytes. Finally, from this work, we were able to identify eight cardiac cell-types; several new coding, lncRNA, and pcRNA markers; two cardiomyocyte subpopulations at four different time points (ventricle E9.5, left ventricle E11.5, right ventricle E14.5 and left atrium P0) that harbored co-expressed gene modules enriched in mitochondrial, heart development and cardiovascular diseases. Our results evidence the role of particular lncRNAs in heart development and highlight the usage of co-expression modular approaches in the cell-type functional definition.

Mesenchymal Stem Cell-Derived Exosomal microRNAs in Cardiac Regeneration

Mesenchymal stem cell (MSC)-based therapy is one of the most promising modalities for cardiac repair. Accumulated evidence suggests that the therapeutic value of MSCs is mainly attributable to exosomes. MSC-derived exosomes (MSC-Exos) replicate the beneficial effects of MSCs by regulating various cellular responses and signaling pathways implicated in cardiac regeneration and repair. miRNAs constitute an important fraction of exosome content and are key contributors to the biological function of MSC-Exo. MSC-Exo carrying specific miRNAs provides anti-apoptotic, anti-inflammatory, anti-fibrotic, and angiogenic effects within the infarcted heart. Studying exosomal miRNAs will provide an important insight into the molecular mechanisms of MSC-Exo in cardiac regeneration and repair. This significant information can help optimize cell-free treatment and overcome the challenges associated with MSC-Exo therapeutic application. In this review, we summarize the characteristics and the potential mechanisms of MSC-derived exosomal miRNAs in cardiac repair and regeneration.

Mechanisms and therapeutic strategies of extracellular vesicles in cardiovascular diseases

Cardiovascular disease (CVD) significantly impacts global society since it is the leading cause of death and disability worldwide, and extracellular vesicle (EV)-based therapies have been extensively investigated. EV delivery is involved in mediating the progression of CVDs and has great potential to be biomarker and therapeutic molecular carrier. Besides, EVs from stem cells and cardiac cells can effectively protect the heart from various pathologic conditions, and then serve as an alternative treatment for CVDs. Moreover, the research of using EVs as delivery carriers of therapeutic molecules, membrane engineering modification of EVs, or combining EVs with biomaterials further improves the application potential of EVs in clinical treatment. However, currently there are only a few articles summarizing the application of EVs in CVDs. This review provides an overview of the role of EVs in the pathogenesis and diagnosis of CVDs. It also focuses on how EVs promote the repair of myocardial injury and therapeutic methods of CVDs. In conclusion, it is of great significance to review the research on the application of EVs in the treatment of CVDs, which lays a foundation for further exploration of the role of EVs, and clarifies the prospect of EVs in the treatment of myocardial injury.

Exosomal Cargo: Pro-angiogeneic, anti-inflammatory, and regenerative effects in ischemic and non-ischemic heart diseases - A comprehensive review

Heart diseases are the primary cause of mortality and morbidity worldwide which inflict a heavy social and economic burden. Among heart diseases, most deaths are due to myocardial infarction (MI) or heart attack, which occurs when a decrement in blood flow to the heart causes injury to cardiac tissue. Despite several available diagnostic, therapeutic, and prognostic approaches, heart disease remains a significant concern. Exosomes are a kind of small extracellular vesicles released by different types of cells that play a part in intercellular communication by transferring bioactive molecules important in regenerative medicine. Many studies have reported the diagnostic, therapeutic, and prognostic role of exosomes in various heart diseases. Herein, we reviewed the roles of exosomes as new emerging agents in various types of heart diseases, including ischemic heart disease, cardiomyopathy, arrhythmia, and valvular disease, focusing on pathogenesis, therapeutic, diagnostic, and prognostic roles in different areas. We have also mentioned different routes of exosome delivery to target tissues, the effects of preconditioning and modification on exosome's capability, exosome production in compliance with good manufacturing practice (GMP), and their ongoing clinical applications in various medical contexts to shed light on possible clinical translation.

Host-microbe tryptophan partitioning in cardiovascular diseases

The functional interdependencies between the molecular components of a biological process demand for a network medicine platform that integrates systems biology and network science, to explore the interactions among biological components in health and disease. Access to large-scale omics datasets (genomics, transcriptomics, proteomics, metabolomics, metagenomics, phenomics, etc.) has significantly advanced our opportunity along this direction. Studies utilizing these techniques have begun to provide us with a deeper understanding of how the interaction between the intestinal microbes and their host affects the cardiovascular system in health and disease. Within the framework of a multiomics network approach, we highlight here how tryptophan metabolism may orchestrate the host-microbes interaction in cardiovascular diseases and the implications for precision medicine and therapeutics, including nutritional interventions.

Exosomes and their derivatives as biomarkers and therapeutic delivery agents for cardiovascular diseases: Situations and challenges

Microvesicles known as exosomes have a diameter of 40 to 160 nm and are derived from small endosomal membranes. Exosomes have attracted increasing attention over the past ten years in part because they are functional vehicles that can deliver a variety of lipids, proteins, and nucleic acids to the target cells they encounter. Because of this function, exosomes may be used for the diagnosis, prognosis and treatment of many diseases. All throughout the world, cardiovascular diseases (CVDs) continue to be a significant cause of death. Because exosomes are mediators of communication between cells, which contribute to many physiological and pathological aspects, they may aid in improving CVD therapies as biomarkers for diagnosing and predicting CVDs. Many studies demonstrated that exosomes are associated with CVDs, such as coronary artery disease, heart failure, cardiomyopathy and atrial fibrillation. Exosomes participate in the progression or inhibition of these diseases mainly through the contents they deliver. However, the application of exosomes in diferent CVDs is not very mature. So further research is needed in this field.

MicroRNAs in atrial fibrillation target genes in structural remodelling

We aim to elucidate how miRNAs regulate the mRNA signature of atrial fibrillation (AF), to gain mechanistic insight and identify candidate targets for future therapies. We present combined miRNA-mRNA sequencing using atrial tissues of patient without AF (n = 22), with paroxysmal AF (n = 22) and with persistent AF (n = 20). mRNA sequencing previously uncovered upregulated epithelial to mesenchymal transition, endothelial cell proliferation and extracellular matrix remodelling involving glycoproteins and proteoglycans in AF. MiRNA co-sequencing discovered miRNAs regulating the mRNA expression changes. Key downregulated miRNAs included miR-135b-5p, miR-138-5p, miR-200a-3p, miR-200b-3p and miR-31-5p and key upregulated miRNAs were miR-144-3p, miR-15b-3p, miR-182-5p miR-18b-5p, miR-4306 and miR-206. MiRNA expression levels were negatively correlated with the expression levels of a multitude of predicted target genes. Downregulated miRNAs associated with increased gene expression are involved in upregulated epithelial and endothelial cell migration and glycosaminoglycan biosynthesis. In vitro inhibition of miR-135b-5p and miR-138-5p validated an effect of miRNAs on multiple predicted targets. Altogether, the discovered miRNAs may be explored in further functional studies as potential targets for anti-fibrotic therapies in AF.

Exosomes derived from cardiac fibroblasts with angiotensin II stimulation provoke hypertrophy and autophagy inhibition in cardiomyocytes

Although accumulating evidence has revealed that autophagy inhibition contributes to the development of pathological cardiac hypertrophy, the mechanisms leading to declined autophagy activity in the hypertrophic heart remain to be elucidated. Exosomes are known to be important mediators of intercellular communication, and the involvement of exosomes in cardiovascular abnormities has attracted increasing attentions. Cardiac fibroblasts (CFs) are the most abundant cell type in the heart. Here, we investigated the potential role of CFs-derived exosomes in regulating cardiomyocyte hypertrophy and autophagy. Exosomes from rat CFs treated with angiotensin II (Ang II-CFs-exosomes) were collected and characterized. Our experiments showed that these exosomes could induce hypertrophic responses and impair autophagy activity in primary neonatal rat cardiomyocytes (NRCMs). Ang II-CFs-exosomes blocked the autophagic flux of NRCMs via inhibiting the formation of autolysosomes. Moreover, the pro-hypertrophic effects and autophagy inhibition induced by Ang II-CFs-exosomes was validated in mice receiving injection of the exosomes. These findings highlight a novel role of Ang II-CFs-exosomes in suppressing cardiomyocyte autophagy, which may help to better understand the pathogenesis of cardiac hypertrophy.

Advances in Intercellular Communication Mediated by Exosomal ncRNAs in Cardiovascular Disease

Cardiovascular diseases are a leading cause of worldwide mortality, and exosomes have recently gained attention as key mediators of intercellular communication in these diseases. Exosomes are double-layered lipid vesicles that can carry biomolecules such as miRNAs, lncRNAs, and circRNAs, and the content of exosomes is dependent on the cell they originated from. They can be involved in the pathophysiological processes of cardiovascular diseases and hold potential as diagnostic and monitoring tools. Exosomes mediate intercellular communication, stimulate or inhibit the activity of target cells, and affect myocardial hypertrophy, injury and infarction, ventricular remodeling, angiogenesis, and atherosclerosis. Exosomes can be released from various types of cells, including endothelial cells, smooth muscle cells, cardiomyocytes, fibroblasts, platelets, adipocytes, immune cells, and stem cells. In this review, we highlight the communication between different cell-derived exosomes and cardiovascular cells, with a focus on the roles of RNAs. This provides new insights for further exploring targeted therapies in the clinical management of cardiovascular diseases.

Periostin is overexpressed, correlated with fibrosis and differs among grades of cardiomyocyte hypertrophy in myectomy tissue of patients with hypertrophic cardiomyopathy

Periostin, a secreted matricellular protein, has been implicated in cardiac extracellular matrix remodeling and fibrosis. Evidence suggest that periostin stimulates cardiomyocyte hypertrophy. The current study aims to investigate the extent of periostin expression in patients with advanced Hypertrophic Cardiomyopathy (HCM) and its correlation with fibrosis and hallmark histopathological features of the disease. Interventricular septal tissue from thirty-nine HCM patients who underwent myectomy and five controls who died from non-cardiac causes was obtained. Staining with Masson's Trichrome and immunohistochemistry were used to localize fibrosis and periostin respectively. The extent of fibrosis and the expression of periostin were defined as the stained percentage of total tissue area using digital pathology software. Periostin expression was higher in HCM patients compared to controls (p<0.0001), positively correlated with the extent of fibrosis (r = 0.82, p<0.001), positively correlated with maximal interventricular septal thickness (Rho = 0.33, p = 0.04) and negatively correlated with LVEF (r = -0.416, p = 0.009). Periostin was approximately co-localized with fibrosis. Mean periostin expression was lower in patients with mild grade cardiomyocyte hypertrophy compared to those with moderate grade (p = 0.049) and lower in patients with mild grade replacement fibrosis compared to moderate grade (p = 0.036). In conclusion, periostin is overexpressed in advanced HCM, correlated with fibrosis and possibly related to cardiomyocyte hypertrophy.

The good, the bad and the ugly: the impact of extracellular vesicles on the cardiovascular system

Cardiovascular diseases (CVDs), which encompass a myriad of pathological conditions that affect the heart and/or the blood vessels, remain the major cause of morbidity and mortality worldwide. By transferring a wide variety of bioactive molecules, including proteins and microRNAs (miRNAs), extracellular vesicles (EVs) are recognized as key players in long-range communication across the cardiovascular system. It has been demonstrated that these highly heterogeneous nanosized vesicles participate both in the maintenance of homeostasis of the heart and vessels, and contribute to the pathophysiology of CVDs, thus emerging as promising tools for diagnosis, prognosis and treatment of multiple CVDs. In this review, we highlight the beneficial roles of EV-mediated communication in regulating vascular homeostasis, and inter-organ crosstalk as a potential mechanism controlling systemic metabolic fitness. In addition, the impact of EV secretion in disease development is described, particularly focusing on cardiac remodelling following ischaemia, atherogenesis and atrial fibrillation progression. Finally, we discuss the potential of endogenous and bioengineered EVs as therapeutic tools for CVDs, as well as the suitability of assessing the molecular signature of circulating EVs as a non-invasive predictive marker of CVD onset and progression. This rapidly expanding field of research has established the role of EVs as key conveyors of both cardioprotective and detrimental signals, which might be of relevance in uncovering novel therapeutic targets and biomarkers of CVDs.

Extracellular vesicles and their non-coding RNA cargos: Emerging players in cardiovascular disease

Extracellular vesicles (EVs), including exosomes, microvesicles and apoptotic bodies, have recently received attention as essential mechanisms for cell-to-cell communication in cardiovascular disease. EVs can be released from different types of cells, including endothelial cells, smooth muscle cells, cardiac cells, fibroblasts, platelets, adipocytes, immune cells and stem cells. Non-coding (nc)RNAs as EV cargos have recently been investigated in the cardiovascular system. Up- or downregulated ncRNAs in EVs have been shown to play a crucial role in various cardiovascular diseases. Communication via EV-derived ncRNAs can occur between cells of the same type and between different types of cells involved in the pathophysiology of cardiovascular disease. In the present review, we highlight the important aspects of diverse cell-derived EVs and their ncRNA cargos as disease mediators and potential therapeutic targets in atherosclerosis, coronary artery disease, ischaemic heart disease and cardiac fibrosis. In addition, we summarize the potential of EV-derived ncRNAs in the treatment of cardiovascular disease. Finally, we discuss the different methods for EV isolation and characterization. A better understanding of the specific role of EVs and their ncRNA cargos in the regulation of cardiovascular (dys)function will be of importance for the development of diagnostic and therapeutic tools for cardiovascular disease.

Bone Mesenchymal Stem Cell-Derived Small Extracellular Vesicles Ameliorated Lipopolysaccharide-Induced Lung Injury Via the miR-21-5p/PCSK6 Pathway

Acute lung injury (ALI) is a life-threatening disease that currently lacks a cure. Although stem cell-derived small extracellular vesicles (sEVs) have shown promising effects in the treatment of ALI, their underlying mechanisms and responsible components have yet to be identified. Proprotein convertase subtilisin/kexin type 6 (PCSK6) is a gene involved in inflammation and a potential target of miR-21-5p, a microRNA enriched in stem cell-derived sEVs. The current study investigated the role of PCSK6 in lipopolysaccharide (LPS)-induced ALI and its interaction with miR-21-5p. Notably, our results showed that PCSK6 expression was positively correlated with LPS stimulation. Knockdown of PCSK6 ameliorated LPS-induced inhibition of proliferation and upregulation of permeability in human BEAS-2B cells, whereas PCSK6 overexpression displayed the opposite effects. BEAS-2B cells were able to actively internalize the cocultured bone mesenchymal stem cell (MSC)-derived sEVs (BMSC-sEVs), which alleviated the cell damage caused by LPS. Overexpressing PCSK6, however, eliminated the therapeutic effects of BMSC-sEV coculture. Mechanistically, BMSC-sEVs inhibited PCSK6 expression via the delivery of miR-21-5p, which is directly bound to the PCSK6 gene. Our work provides evidence for the role of PCSK6 in LPS-induced ALI and identified miR-21-5p as a component of BMSC-derived sEVs that suppressed PCSK6 expression and ameliorated LPS-induced cell damage. These results reveal a novel molecular mechanism for ALI pathogenesis and highlight the therapeutic potential of using sEVs released by stem cells to deliver miR-21-5p for ALI treatment.

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.

Exosome-shuttled miR-126 mediates ethanol-induced disruption of neural crest cell-placode cell interaction by targeting SDF1

During embryonic development, 2 populations of multipotent stem cells, cranial neural crest cells (NCCs) and epibranchial placode cells (PCs), are anatomically adjacent to each other. The coordinated migration of NCCs and PCs plays a major role in the morphogenesis of craniofacial skeletons and cranial nerves. It is known that ethanol-induced dysfunction of NCCs and PCs is a key contributor to the defects of craniofacial skeletons and cranial nerves implicated in fetal alcohol spectrum disorder (FASD). However, how ethanol disrupts the coordinated interaction between NCCs and PCs was not elucidated. To fill in this gap, we established a well-designed cell coculture system to investigate the reciprocal interaction between human NCCs (hNCCs) and human PCs (hPCs), and also monitored the migration behavior of NCCs and PCs in zebrafish embryos. We found that ethanol exposure resulted in a disruption of coordinated hNCCs-hPCs interaction, as well as in zebrafish embryos. Treating hNCCs-hPCs with exosomes derived from ethanol-exposed hNCCs (ExoEtOH) mimicked ethanol-induced impairment of hNCCs-hPCs interaction. We also observed that SDF1, a chemoattractant, was downregulated in ethanol-treated hPCs and zebrafish embryos. Meanwhile, miR-126 level in ExoEtOH was significantly higher than that in control exosomes (ExoCon). We further validated that ExoEtOH-encapsulated miR-126 from hNCCs can be transferred to hPCs to suppress SDF1 expression in hPCs. Knockdown of SDF1 replicated ethanol-induced abnormalities either in vitro or in zebrafish embryos. On the contrary, overexpression of SDF1 or inhibiting miR-126 strongly rescued ethanol-induced impairment of hNCCs-hPCs interaction and developmental defects.

The Roles of microRNAs in the Cardiovascular System

The discovery of miRNAs and their role in disease represent a significant breakthrough that has stimulated and propelled research on miRNAs as targets for diagnosis and therapy. Cardiovascular disease is an area where the restrictions of early diagnosis and conventional pharmacotherapy are evident and deserve attention. Therefore, miRNA-based drugs have significant potential for development. Research and its application can make considerable progress, as seen in preclinical and clinical trials. The use of miRNAs is still experimental but has a promising role in diagnosing and predicting a variety of acute coronary syndrome presentations. Its use, either alone or in combination with currently available biomarkers, might be adopted soon, particularly if there is diagnostic ambiguity. In this review, we examine the current understanding of miRNAs as possible targets for diagnosis and treatment in the cardiovascular system. We report on recent advances in recognising and characterising miRNAs with a focus on clinical translation. The latest challenges and perspectives towards clinical application are discussed.

Epigenetic Regulation of Fibroblasts and Crosstalk between Cardiomyocytes and Non-Myocyte Cells in Cardiac Fibrosis

Epigenetic mechanisms and cell crosstalk have been shown to play important roles in the initiation and progression of cardiac fibrosis. This review article aims to provide a thorough overview of the epigenetic mechanisms involved in fibroblast regulation. During fibrosis, fibroblast epigenetic regulation encompasses a multitude of mechanisms, including DNA methylation, histone acetylation and methylation, and chromatin remodeling. These mechanisms regulate the phenotype of fibroblasts and the extracellular matrix composition by modulating gene expression, thereby orchestrating the progression of cardiac fibrosis. Moreover, cardiac fibrosis disrupts normal cardiac function by imposing myocardial mechanical stress and compromising cardiac electrical conduction. This review article also delves into the intricate crosstalk between cardiomyocytes and non-cardiomyocytes in the heart. A comprehensive understanding of the mechanisms governing epigenetic regulation and cell crosstalk in cardiac fibrosis is critical for the development of effective therapeutic strategies. Further research is warranted to unravel the precise molecular mechanisms underpinning these processes and to identify potential therapeutic targets.