Plasma exosomes induced by remote ischaemic preconditioning attenuate myocardial ischaemia/reperfusion injury by transferring miR-24

Role of Exosomes in Cardiovascular Disease: A Key Regulator of Intercellular Communication in Cardiomyocytes

In the cardiovascular system, different types of cardiovascular cells can secrete specific exosomes and participate in the maintenance of cardiovascular function and the occurrence and development of diseases. Exosomes carry biologically active substances such as proteins and nucleic acids from cells of origin and can be used as biomarkers for disease diagnosis and prognosis assessment. In addition, exosome-mediated intercellular communication plays a key role in the occurrence and development of cardiovascular diseases and has become a potential therapeutic target. This article emphasizes the importance of understanding the mechanism of exosomes in cardiovascular diseases and systematically details the current understanding of exosomes as regulators of intercellular communication in cardiomyocytes, providing a basis for future research and therapeutic intervention.

Critical analysis of descriptive microRNA data in the translational research on cardioprotection and cardiac repair: lost in the complexity of bioinformatics

The unsuccessful translation of cardiac regeneration and cardioprotection from animal experiments to clinical applications in humans has raised the question of whether microRNA bioinformatics can narrow the gap between animal and human research outputs. We reviewed the literature for the period between 2000 and 2024 and found 178 microRNAs involved in cardioprotection and cardiac regeneration. On analyzing the orthologs and annotations, as well as downstream regulation, we observed species-specific differences in the diverse regulation of the microRNAs and related genes and transcriptomes, the influence of the experimental setting on the microRNA-guided biological responses, and database-specific bioinformatics results. We concluded that, in addition to reducing the number of in vivo experiments, following the 3R animal experiment rules, the bioinformatics approach allows the prediction of several currently unknown interactions between pathways, coding and non-coding genes, proteins, and downstream regulatory elements. However, a comprehensive analysis of the miRNA-mRNA-protein networks needs a profound bioinformatics and mathematical education and training to appropriately design an experimental study, select the right bioinformatics tool with programming language skills and understand and display the bioinformatics output of the results to translate the research data into clinical practice. In addition, using in-silico approaches, a risk of deviating from the in vivo processes exists, with adverse consequences on the translational research.

Exosomal miR-203 from bone marrow stem cells targets the SOCS3/NF-κB pathway to regulate neuroinflammation in temporal lobe epilepsy

BACKGROUND

Epilepsy is a prevalent chronic neurological disorder affecting 50 million individuals globally, with temporal lobe epilepsy (TLE) being the most common form. Despite advances in antiepileptic drug development, over 30% of patients suffer from drug-resistant epilepsy, which can lead to severe cognitive impairments and adverse psychosocial outcomes.

AIM

To explore the role of bone marrow mesenchymal stem cell (BMSC)-derived exosomal miR-203 in the regulation of neuroinflammation in a mouse model of epilepsy, providing a theoretical basis for the development of targeted microRNA delivery therapies for drug-resistant epilepsy.

METHODS

Adult male C57BL/6 mice were divided into a control group and a TLE model of 30 mice each, and the TLE model group was established by injecting kainic acid. BMSCs were isolated from the mice, and exosomes were purified using ultracentrifugation. Exosomal miR-203 was identified and characterized using high-throughput sequencing and quantitative reverse-transcription polymerase chain reaction. The uptake of exosomes by hippocampal neurons and the subsequent effects on neuroinflammatory markers were assessed using in vitro cell culture models.

RESULTS

Exosomal miR-203 exhibited a significant upregulation in BMSCs derived from epileptic mice. In vitro investigations demonstrated the efficient internalization of these exosomes by hippocampal neurons, resulting in downregulation of suppressor of cytokine signaling 3 expression and activation of the nuclear factor kappaB pathway, ultimately leading to enhanced secretion of pro-inflammatory cytokines.

CONCLUSION

Our study identifies exosomal miR-203 as a key regulator of neuroinflammation in a mouse model of epilepsy. The findings suggest that targeting miR-203 may offer a novel therapeutic strategy for epilepsy by modulating the suppression of cytokine signaling 3/nuclear factor kappaB pathway, thus providing a potential avenue for the development of cell-free therapeutics.

Assessing platelet-derived extracellular vesicles for potential as therapeutic targets in cardiovascular diseases

INTRODUCTION

Cardiovascular disease (CVD) is the leading cause of death worldwide. Platelet-derived extracellular vesicles (PEV) have attracted extensive attention in cardiovascular disease research in recent years because their cargo is involved in a variety of pathophysiological processes, such as thrombosis, immune response, promotion or inhibition of inflammatory response, promotion of angiogenesis as well as cell proliferation and migration.

AREAS COVERED

This review explores the role of PEV in various cardiovascular diseases (such as atherosclerosis, myocardial infarction, ischemia-reperfusion injury, and heart failure), with relation to its molecular cargo (nucleic acids, bioactive lipids, proteins) and aims to provide new insights in the pathophysiologic role of PEV, and methods for preventing and treating cardiovascular diseases based on PEV.

EXPERT OPINION

Studies have shown that the cargo of PEV may be dysregulated during cardiovascular disease and delivery to tissues can result in detrimental pathophysiologic effects. Counteracting this process might have the potential to inhibit inflammation, promote angiogenesis, and inhibit cardiomyocyte death. In addition, PEV have potential as biocompatible and autologous drug carriers. Therefore, better research on the mechanisms how PEV act during cardiovascular disease and could be implemented as a therapeutic will provide new perspectives for the treatment of cardiovascular disease.

CircCHSY1 protects hearts against ischaemia/reperfusion injury by enhancing heme oxygenase 1 expression via miR-24-3p

AIMS

Circular RNAs (circRNAs) are important players involved in a variety of physiological and pathological processes. However, their functions and mechanisms during myocardial ischaemic injury and protection remain largely unknown. We recently found significant alterations of many circRNAs including circCHSY1 following myocardial ischaemia/reperfusion (I/R) injury, whereas their exact functions are unclear. Here, we investigated the roles of circCHSY1 in the acute myocardial I/R injury and the potential mechanisms involved.

METHODS AND RESULTS

The expression of circCHSY1 was detected in cardiomyocytes from mouse, rat, and human embryonic stem cells (hESC-CMs). It was further up-regulated in mouse I/R (30 min/24 h) hearts, oxygen glucose deprivation/reperfusion (OGD/R, 6 h/2 h) primary neonatal rat ventricular cardiomyocytes (NRCMs) and OGD/R (48 h/2 h) hESC-CMs. Adenovirus-mediated circCHSY1 overexpression significantly decreased infarct size and lactate dehydrogenase (LDH) release in mouse I/R hearts. Consistently, circCHSY1 overexpression reduced the LDH release in the OGD/R NRCMs and hESC-CMs, improved cell viability, and preserved mitochondrial function in the OGD/R NRCMs, whereas there were no significant differences in cell viability and LDH release between the OGD/R NRCMs with and without small interfering RNA (siRNA)-mediated circCHSY1 knockdown. Mechanistically, circCHSY1 was detected to bind with miR-24-3p analysed by dual-luciferase assay and RNA pull-down assays. CircCHSY1 overexpression-mediated protective effects on cells and mitochondria in OGD/R NRCMs were reversed by the miR-24-3p mimic. Furthermore, dual-luciferase assay showed that miR-24-3p was directly bound to heme oxygenase 1 (HO1) via its 3'UTR. The protein level of HO1 was down-regulated by miR-24-3p mimic in OGD/R NRCMs but enhanced by the circCHSY1 overexpression in vitro and in vivo. Functionally, the HO1 knockdown by adenovirus in vivo and by siRNA in vitro eliminated cardioprotective effects of circCHSY1 overexpression.

CONCLUSION

CircCHSY1 is up-regulated following myocardial I/R injury. The higher level of circCHSY1 protects I/R hearts and cardiomyocytes. The protection of circCHSY1 is mediated through enhancement of the HO1 level, resulting in preserving mitochondrial homoeostasis via targeting miR-24-3p in cardiomyocytes. These findings suggest circCHSY1 as a protective factor.

Systemic administration of blood-derived exosomes induced by remote ischemic post-conditioning, by delivering a specific cluster of miRNAs, ameliorates ischemic damage and neurological function

MicroRNAs, contained in exosomes or freely circulating in the plasma, might play a pivotal role in the infarct-sparing effect exerted by remote limb ischemic postconditioning (RLIP). The aims of the present study were: (1) To evaluate the effect of pure exosomes isolated from plasma of animals subjected to RLIP systemically administered to ischemic rats; (2) To finely dissect exosomes content in terms of miRNAs; (3) To select those regulatory miRNAs specifically expressed in protective exosomes and to identify molecular pathways involved in their neurobeneficial effects. Circulating exosomes were isolated from blood of animals exposed to RLIP and administered to animals exposed to tMCAO by intracerebroventricular, intraperitoneal or intranasal routes. Exosomal miRNA signature was evaluated by microarray and FISH analysis. Plasmatic exosomes isolated from plasma of RLIP rats attenuated cerebral ischemia reperfusion injury and improved neurological functions until 3 days after ischemia induction. Interestingly, miR-702-3p and miR-423-5p seem to be mainly involved in exosome protective action by modulating NOD1 and NLRP3, two key triggers of neuroinflammation and neuronal death. Collectively, the results of the present work demonstrated that plasma-released exosomes after RLIP may transfer a neuroprotective signal to the brain of ischemic animals, thus representing a potentially translatable therapeutic strategy in stroke.

Exosomes from myoblasts induced by hypoxic preconditioning improved ventricular conduction by increasing Cx43 expression in hypothermia ischemia reperfusion hearts

Myocardial ischemia-reperfusion arrhythmia after cardiac surgery is common and seriously affects quality of life. Remote ischemic preconditioning can reduce the myocardial damage caused by severe ischemia. However, the underlying mechanism is not well understood. This study aimed to investigate the effects of exosomes derived from C2C12 mouse myoblasts after hypoxic preconditioning (HP) on ventricular conduction in hypothermic ischemia-reperfusion hearts. Myocardial ischemia-reperfusion model rats were established using the Langendorff cardiac perfusion system. Exosomes derived from normoxic (ExoA) and hypoxia-preconditioned (ExoB) C2C12 cells were injected into the jugular vein of the model rats. The time to heartbeat restoration, arrhythmia type and duration, and heart rate were recorded after myocardial ischemia-reperfusion. Conduction velocity on the surface of left ventricle was measured using a microelectrode array after 30 min of balanced perfusion, 15 min of reperfusion, and 30 min of reperfusion. Immunohistochemistry and western blotting were performed to determine the distribution and relative expression of connexin 43 (Cx43). ExoB contained more exosomes than ExoA, showing that HP stimulated the release of exosomes. The IR + ExoB group showed faster recovery of ventricular myocardial activity, a lower arrhythmia score, faster conduction velocity, and better electrical conductivity than the IR group. ExoB increased the expression of Cx43 and reduced its lateralization in the ventricular muscle. Our study showed that exosomes induced by hypoxic preconditioning can improve ventricular myocardial conduction and reperfusion arrhythmia in isolated hearts after hypothermic ischemia-reperfusion.

Graphical abstract

Research progress of exosomes from different sources in myocardial ischemia

Ischemic heart disease refers to the imbalance between the supply and demand of myocardial blood; it has various causes and results in a class of clinical diseases characterized by myocardial ischemia (MI). In recent years, the incidence of cardiovascular disease has become higher and higher, and the number of patients with ischemic heart disease has also increased year by year. Traditional treatment methods include drug therapy and surgical treatment, both of which have limitations. The former maybe develop risks of drug resistance and has more significant side effects, while the latter may damage blood vessels and risk infection. At this stage, a new cell-free treatment method needs to be explored. Many research results have shown that exosomes from different cell sources can protect the ischemic myocardium via intercellular action methods, such as promoting angiogenesis, inhibiting myocardial fibrosis, apoptosis and pyroptosis, and providing a new basis for the treatment of MI. In this review, we briefly introduce the formation and consequences of myocardial ischemia and the biology of exosomes, and then focus on the role and mechanism of exosomes from different sources in MI. We also discuss the role and mechanism of exosomes pretreated with Chinese and Western medicines on myocardial ischemia. We also discuss the potential of exosomes as diagnostic markers and therapeutic drug for MI.

Ischemic-Preconditioning Induced Serum Exosomal miR-133a-3p Improved Post-Myocardial Infarction Repair via Targeting LTBP1 and PPP2CA

Background

Ischemic preconditioning-induced serum exosomes (IPC-exo) protected rat heart against myocardial ischemia/reperfusion injury. However, whether IPC-exo regulate replacement fibrosis after myocardial infarction (MI) and the underlying mechanisms remain unclear. MicroRNAs (miRs) are important cargos of exosomes and play an essential role in cardioprotection. We aim to investigate whether IPC-exo regulate post-MI replacement fibrosis by transferring cardioprotective miRs and its action mechanism.

Methods

Exosomes obtained from serum of adult rats in control (Con-exo) and IPC groups were identified and analyzed, subsequently intracardially injected into MI rats following ligation. Their miRs profiles were identified using high-throughput miR sequencing to identify target miRs for bioinformatics analysis. Luciferase reporter assays confirmed target genes of selected miRs. IPC-exo transfected with selected miRs antagomir or NC were intracardially administered to MI rats post-ligation. Cardiac function and degree of replacement fibrosis were detected 4 weeks post-MI.

Results

IPC-exo exerted cardioprotective effects against excessive replacement fibrosis. MiR sequencing and RT-qPCR identified miR-133a-3p as most significantly different between IPC-exo and Con-exo. MiR-133a-3p directly targeted latent transforming growth factor beta binding protein 1 (LTBP1) and protein phosphatase 2, catalytic subunit, alpha isozyme (PPP2CA). KEGG analysis showed that transforming growth factor-β (TGF-β) was one of the most enriched signaling pathways with miR-133a-3p. Comparing to injection of IPC-exo transfected with miR-133a-3p antagomir NC, injecting IPC-exo transfected with miR-133a-3p antagomir abolished protective effects of IPC-exo on declining excessive replacement fibrosis and cardiac function enhancement, while increasing the messenger RNA and protein expression of LTBP1, PPP2CA, and TGF-β1in MI rats.

Conclusion

IPC-exo inhibit excessive replacement fibrosis and improve cardiac function post-MI by transferring miR-133a-3p, the mechanism is associated with directly targeting LTBP1 and PPP2CA, and indirectly regulating TGF-β pathway in rats. Our finding provides potential therapeutic effect of IPC-induced exosomal miR-133a-3p for cardiac repair.

A systematic review of exosomes in remote ischemic conditioning

BACKGROUND

Remote ischemic conditioning (RIC) is considered a promising non-pharmacological therapeutic strategy to mitigate ischemic injury. Although the precise mechanisms of RIC's protective effects remain elusive, existing data suggest that exosomes contribute significantly to these processes through cell-to-cell communication OBJECTIVE: This review aims to elucidate the role of exosomes in RIC-mediated multi-organ protection.

METHODS

We systematically searched multiple databases through October 2023 for preclinical studies evaluating the effect of exosomes in ischemic models using RIC procedures. Key outcomes, such as improved organ function and reduced infarct size, were recorded. Articles were selected and data were extracted by independent pairs of reviewers.

FINDINGS

A total of 16 relevant studies were identified in this review, showing that circulating exosomes derived from the plasma of RIC-treated animals exhibited protective effects akin to those of the RIC procedure itself. Exosome concentrations were measured in eight studies, six of which reported significant increases in the RIC group. Additional findings indicated that RIC might primarily modulate the expression of miRNAs and bioactive molecules delivered by exosomes, rather than directly altering circulating exosome levels. Notably, the expression of 11 distinct exosomal miRNAs was altered after RIC intervention, potentially involving multiple pathways.

CONCLUSION

Exosomes appear to play a pivotal role in the protective effects induced by RIC. Clarifying their function in RIC under different pathological situations represents a grand challenge for future research.

ALDH2 polymorphism and myocardial infarction: From alcohol metabolism to redox regulation

Acute myocardial infarction (AMI) remains a leading cause of death worldwide. Increased formation of reactive oxygen species (ROS) during the early reperfusion phase is thought to trigger lipid peroxidation and disrupt redox homeostasis, leading to myocardial injury. Whilst the mitochondrial enzyme aldehyde dehydrogenase 2 (ALDH2) is chiefly recognised for its central role in ethanol metabolism, substantial experimental evidence suggests an additional cardioprotective role for ALDH2 independent of alcohol intake, which mitigates myocardial injury by detoxifying breakdown products of lipid peroxidation including the reactive aldehydes, malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE). Epidemiological evidence suggests that an ALDH2 mutant variant with reduced activity that is highly prevalent in the East Asian population increases AMI risk. Additional studies have uncovered a strong association between coronary heart disease and this ALDH2 mutant variant. It appears this enzyme polymorphism (in particular, in ALDH2*2/2 carriers) has the potential to have wide-ranging effects on thiol reactivity, redox tone and therefore numerous redox-related signaling processes, resilience of the heart to cope with lifestyle-related and environmental stressors, and the ability of the whole body to achieve redox balance. In this review, we summarize the journey of ALDH2 from a mitochondrial reductase linked to alcohol metabolism, via pre-clinical studies aimed at stimulating ALDH2 activity to reduce myocardial injury to clinical evidence for its protective role in the heart.

Biological resilience in health and disease

All living organisms - from single-celled prokaryotes through to invertebrates and humans - are frequently exposed to numerous challenges during their lifetime, which could damage their molecular and cellular contents and threaten their survival. Nevertheless, these diverse organisms are, on the whole, remarkably resilient to potential threats. Recent years have seen rapid advances in our mechanistic understanding of this emerging phenomenon of biological resilience, which enables cells, tissues and whole organisms to bounce back from challenges or stress. In this At a Glance article, I discuss current knowledge on the diverse molecular mechanisms driving biological resilience across scales, with particular focus on its dynamic and adaptive nature. I highlight emerging evidence that loss of biological resilience could underly numerous pathologies, including age-related frailty and degenerative disease. Finally, I present the multi-disciplinary experimental approaches that are helping to unravel the causal mechanisms of resilience and how this emerging knowledge could be harnessed therapeutically in the clinic.

Human Plasma‐Derived Extracellular Vesicles Protect Against Cerebral Ischemia‐Reperfusion Injury via HSP27 Phosphorylation

Ischemic stroke (IS) has become a serious public health problem, with patients undergoing endovascular treatment experiencing ischemia‐reperfusion (I/R) injury, which exacerbates cerebrovascular diseases. Circulating extracellular vesicles (EVs) have shown potential for treating cerebral I/R injury. In this study, the therapeutic effect of human plasma‐derived EVs and protective mechanisms in cerebral I/R injury is explored. An oxygen‐glucose deprivation/reperfusion (OGD/R) model is used to treat SH‐SY5Y cells in vitro, and an I/R injury model is constructed by transient middle cerebral artery occlusion (tMCAO) in mice. Human plasma‐derived EVs are extracted by size exclusion chromatography. Western blot, Immunofluorescence Staining, and 2,3,5‐Triphenyltetrazolium Chloride (TTC) Staining are employed to observe the effects of EVs on the neuroinflammatory response and infarct volumes in tMCAO mice, while TUNEL Staining, Flow Cytometry, and Western Blot are employed to assess cell apoptosis. Human plasma‐derived EVs alleviated apoptosis in SH‐SY5Y cells under OGD/R stress and exerted a protective effect against brain I/R injury in tMCAO mice. Mechanistically, EVs protected against cerebral I/R injury via HSP27 phosphorylation, and the HSP27 phosphorylation inhibitor KRIBB3 attenuated the anti‐apoptotic effects of EVs. Human plasma‐derived EVs activated the phosphorylation of HSP27, thereby inhibiting cell apoptosis and protecting against cerebral I/R injury.

Delivery-mediated exosomal therapeutics in ischemia-reperfusion injury: advances, mechanisms, and future directions

Ischemia-reperfusion injury (IRI) poses significant challenges across various organ systems, including the heart, brain, and kidneys. Exosomes have shown great potentials and applications in mitigating IRI-induced cell and tissue damage through modulating inflammatory responses, enhancing angiogenesis, and promoting tissue repair. Despite these advances, a more systematic understanding of exosomes from different sources and their biotransport is critical for optimizing therapeutic efficacy and accelerating the clinical adoption of exosomes for IRI therapies. Therefore, this review article overviews the administration routes of exosomes from different sources, such as mesenchymal stem cells and other somatic cells, in the context of IRI treatment. Furthermore, this article covers how the delivered exosomes modulate molecular pathways of recipient cells, aiding in the prevention of cell death and the promotions of regeneration in IRI models. In the end, this article discusses the ongoing research efforts and propose future research directions of exosome-based therapies.

Impact of Wildfires on Cardiovascular Health

Wildfire smoke (WFS) is a mixture of respirable particulate matter, environmental gases, and other hazardous pollutants that originate from the unplanned burning of arid vegetation during wildfires. The increasing size and frequency of recent wildfires has escalated public and occupational health concerns regarding WFS inhalation, by either individuals living nearby and downstream an active fire or wildland firefighters and other workers that face unavoidable exposure because of their profession. In this review, we first synthesize current evidence from environmental, controlled, and interventional human exposure studies, to highlight positive associations between WFS inhalation and cardiovascular morbidity and mortality. Motivated by these findings, we discuss preventative measures and suggest interventions to mitigate the cardiovascular impact of wildfires. We then review animal and cell exposure studies to call attention on the pathophysiological processes that support the deterioration of cardiovascular tissues and organs in response to WFS inhalation. Acknowledging the challenges of integrating evidence across independent sources, we contextualize laboratory-scale exposure approaches according to the biological processes that they model and offer suggestions for ensuring relevance to the human condition. Noting that wildfires are significant contributors to ambient air pollution, we compare the biological responses triggered by WFS to those of other harmful pollutants. We also review evidence for how WFS inhalation may trigger mechanisms that have been proposed as mediators of adverse cardiovascular effects upon exposure to air pollution. We finally conclude by highlighting research areas that demand further consideration. Overall, we aspire for this work to serve as a catalyst for regulatory initiatives to mitigate the adverse cardiovascular effects of WFS inhalation in the community and alleviate the occupational risk in wildland firefighters.

Stem cell therapy for cardiac regeneration: past, present, and future

Cardiac disorders remain the leading cause of mortality worldwide. Current clinical strategies, including drug therapy, surgical interventions, and organ transplantation offer limited benefits to patients without regenerating the damaged myocardium. Over the past decade, stem cell therapy has generated a keen interest owing to its unique self-renewal and immune privileged characteristics. Furthermore, the ability of stem cells to differentiate into specialized cell types, has made them a popular therapeutic tool against various diseases. This comprehensive review provides an overview of therapeutic potential of different types of stem cells in reference to cardiovascular diseases. Furthermore, it sheds light on the advantages and limitations associated with each cell type. An in-depth analysis of the challenges associated with stem cell research and the hurdles for its clinical translation and their possible solutions have also been elaborated upon. It examines the controversies surrounding embryonic stem cells and the emergence of alternative approaches, such as the use of induced pluripotent stem cells for cardiac therapeutic applications. Overall, this review serves as a valuable resource for researchers, clinicians, and policymakers involved in the field of regenerative medicine, guiding the development of safe and effective stem cell-based therapies to revolutionize patient care.

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.

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.

Is Intrinsic Cardioprotection a Laboratory Phenomenon or a Clinically Relevant Tool to Salvage the Failing Heart?

Cardiovascular diseases, especially ischemic heart disease, as a leading cause of heart failure (HF) and mortality, will not reduce over the coming decades despite the progress in pharmacotherapy, interventional cardiology, and surgery. Although patients surviving acute myocardial infarction live longer, alteration of heart function will later lead to HF. Its rising incidence represents a danger, especially among the elderly, with data showing more unfavorable results among females than among males. Experiments revealed an infarct-sparing effect of ischemic "preconditioning" (IPC) as the most robust form of innate cardioprotection based on the heart's adaptation to moderate stress, increasing its resistance to severe insults. However, translation to clinical practice is limited by technical requirements and limited time. Novel forms of adaptive interventions, such as "remote" IPC, have already been applied in patients, albeit with different effectiveness. Cardiac ischemic tolerance can also be increased by other noninvasive approaches, such as adaptation to hypoxia- or exercise-induced preconditioning. Although their molecular mechanisms are not yet fully understood, some noninvasive modalities appear to be promising novel strategies for fighting HF through targeting its numerous mechanisms. In this review, we will discuss the molecular mechanisms of heart injury and repair, as well as interventions that have potential to be used in the treatment of patients.

Exosomes as cutting-edge therapeutics in various biomedical applications: An update on engineering, delivery, and preclinical studies

Exosomes are cell-derived nanovesicles, circulating in different body fluids, and acting as an intercellular mechanism. They can be purified from culture media of different cell types and carry an enriched content of various protein and nucleic acid molecules originating from their parental cells. It was indicated that the exosomal cargo can mediate immune responses via many signaling pathways. Over recent years, the therapeutic effects of various exosome types were broadly investigated in many preclinical studies. Herein, we present an update on recent preclinical studies on exosomes as therapeutic and/or delivery agents for various applications. The exosome origin, structural modifications, natural or loaded active ingredients, size, and research outcomes were summarized for various diseases. Overall, the present article provides an overview of the latest exosome research interests and developments to clear the way for the clinical study design and application.

Exosome is involved in liver graft protection after remote ischemia reperfusion conditioning

BACKGROUND

Remote ischemic perconditioning (RIPerC) has been demonstrated to protect grafts from hepatic ischemia-reperfusion injury (IRI). This study investigated the role of exosomes in RIPerC of liver grafts in rats.

METHODS

Twenty-five rats (including 10 donors) were randomly divided into five groups (n = 5 each group): five rats were used as sham-operated controls (Sham), ten rats were for orthotopic liver transplantation (OLT, 5 donors and 5 recipients) and ten rats were for OLT + RIPerC (5 donors and 5 recipients). Liver architecture and function were evaluated.

RESULTS

Compared to the OLT group, the OLT + RIPerC group exhibited significantly improved liver graft histopathology and liver function (P < 0.05). Furthermore, the number of exosomes and the level of P-Akt were increased in the OLT + RIPerC group.

CONCLUSIONS

RIPerC effectively improves graft architecture and function, and this protective effect may be related to the increased number of exosomes. The upregulation of P-Akt may be involved in underlying mechanisms.

Research Progress of Exosomal Non-Coding RNAs in Cardiac Remodeling

Exosomes are vesicles with a size range of 50 to 200 nm and released by different cells, which are essential for the exchange of information between cells. They have attracted a lot of interest from medical researchers. Exosomal non-coding RNAs play an important part in pathological cardiac remodelings, such as cardiomyocyte hypertrophy, cardiomyocyte apoptosis, and cardiac fibrosis. This review summarizes the origins and functions of exosomes, the role of exosomal non-coding RNAs in the process of pathological cardiac remodeling, as well as their theoretical basis for clinical application.

Stem cells derived exosomes and biomaterials to modulate autophagy and mend broken hearts

Autophagy maintains cellular homeostasis and plays a crucial role in managing pathological conditions including ischemic myocardial injury leading to heart failure (HF). Despite treatments, no intervention can replace lost cardiomyocytes. Stem cell therapy offers potential for post-myocardial infarction repair but struggles with poor cell retention due to immune rejection. In the search for effective therapies, stem cell-derived extracellular vesicles (EVs), especially exosomes, have emerged as promising tools. These tiny bioactive molecule carriers play vital roles in intercellular communication and tissue engineering. They offer numerous therapeutic benefits including modulating immune responses, promoting tissue repair, and boosting angiogenesis. Additionally, biomaterials provide a conducive 3D microenvironment for cell, exosome, and biomolecule delivery, and enhance heart muscle strength, making it a comprehensive cardiac repair strategy. In this regard, the current review delves into the intricate application of extracellular vesicles (EVs) and biomaterials for managing autophagy in the heart muscle during cardiac injury. Central to our investigation is the exploration of how these elements interact within the context of cardiac repair and regeneration. Additionally, this review also casts light on the formidable challenges that plague this field, such as the issues of safety, efficacy, controlled delivery, and acceptance of these therapeutic strategies for effective clinical translation. Addressing these challenges is crucial for unlocking the full therapeutic potential of EV and biomaterial-based therapies and ensuring their successful translation from bench to bedside.

Plasma Small Extracellular Vesicle Cardiac miRNA Expression in Patients with Ischemic Heart Failure, Randomized to Percutaneous Intramyocardial Treatment of Adipose Derived Stem Cells or Placebo: Subanalysis of the SCIENCE Study

Small extracellular vesicles (EVs) and their cargo are an important component of cell-to-cell communication in cardiac disease. Allogeneic adipose derived stem cells (ADSCs) are thought to be a potential approach for cardiac regenerative therapy in ischemic heart disease. The SCIENCE study investigated the effect of ADSCs administered via intramyocardial injection on cardiac function in patients with ischemic heart disease. The aim of this substudy, based on samples from 15 patients, was to explore small EV miRNA dynamics after treatment with ADSCs compared to a placebo. Small EVs were isolated at several timepoints after the percutaneous intramyocardial application of ADSCs. No significant effect of ADSC treatment on small EV concentration was detected. After 12 months, the expression of miR-126 decreased significantly in ADSC patients, but not in the placebo-treated group. However, all cardiac miRNAs correlated with plasma cardiac biomarkers. In line with the overall negative results of the SCIENCE study, with the exception of one miR, we did not detect any significant regulation of small EV miRNAs in this patient collective.

Cardiosome-mediated protection in myocardial ischemia

Cardiosomes, exosomes released in cardiospheres by cardiomyocytes and progenitor cells, communicate locally and at a distance from different tissues, promoting beneficial cellular changes. For example, miRNAs have emerged as regulators of intercellular communication via transport by extracellular vesicles in general and cardiosomes specifically. Although cardiosomes are considered biomarkers owing to their immense biomedical application in various clinical fields, their role in cardiovascular diseases remains unclear. This mini-review examines the experimental and clinical evidence for cardiosomes as non-invasive diagnostic, treatment and prognostic tools in acute myocardial infarction, the novelty of which is often lost in medical practice. In addition, we discuss the potential role of cardiosomes in physiologic mechanisms and cell signaling in cardiac conditioning strategies against reperfusion injury.

Transplantation of Exercise-Induced Extracellular Vesicles as a Promising Therapeutic Approach in Ischemic Stroke

Clinical evidence affirms physical exercise is effective in preventive and rehabilitation approaches for ischemic stroke. This sustainable efficacy is independent of cardiovascular risk factors and associates substantial reprogramming in circulating extracellular vesicles (EVs). The intricate journey of pluripotent exercise-induced EVs from parental cells to the whole-body and infiltration to cerebrovascular entity offers several mechanisms to reduce stroke incidence and injury or accelerate the subsequent recovery. This review delineates the potential roles of EVs as prospective effectors of exercise. The candidate miRNA and peptide cargo of exercise-induced EVs with both atheroprotective and neuroprotective characteristics are discussed, along with their presumed targets and pathway interactions. The existing literature provides solid ground to hypothesize that the rich vesicles link exercise to stroke prevention and rehabilitation. However, there are several open questions about the exercise stressors which may optimally regulate EVs kinetic and boost brain mitochondrial adaptations. This review represents a novel perspective on achieving brain fitness against stroke through transplantation of multi-potential EVs generated by multi-parental cells, which is exceptionally reachable in an exercising body.

Endothelial activation impairs the function of small extracellular vesicles

Small extracellular vesicles are nanosized vesicles (30–200 nm) that can ferry proteins, nucleic acids, and lipids between cells and therefore, have significant potential as biomarkers, drug delivery tools or therapeutic agents. SEVs of endothelial origin have been shown to -among other functions-reduce in vitro ischemia/reperfusion (I/R) injury in cardiomyocytes, but whether a pro-inflammatory state of the endothelium impairs the functionality of these SEVs remains to be elucidated. To test this, human umbilical vein endothelial cells cells were treated with TNF-α 10 ng/mL and the expression of the pro-inflammatory parameters VCAM-1, ICAM-1 and eNOS were determined by Western blot. SEVs were isolated from endothelial cells treated with or without TNF-α 10 ng/mL using size exclusion chromatography. The size and concentration of SEVs was measured by Nanoparticle Tracking Analysis. The expression of the surface marker CD81 was determined by immunoassay, whereas their morphology was assessed by electron microscopy. The function of endothelial SEVs was assessed by evaluating their cardioprotective effect in an ex vivo model of global I/R using isolated hearts from adult C57BL/6 mice. Treatment of HUVECs with TNF-α induced the expression of VCAM-1 and ICAM-1, whereas eNOS levels were decreased. TNF-α did not affect the production, size, morphology, or expression of CD81. SEVs significantly reduced the infarct size as compared with untreated mice hearts, but SEVs isolated from TNF-α treated cells were unable to achieve this effect. Therefore, a pro-inflammatory state induced by TNF-α does not alter the production of endothelial SEVs but impairs their function in the setting of I/R injury.

The Role of ncRNAs in Cardiac Infarction and Regeneration

Myocardial infarction is the most prevalent cardiovascular disease worldwide, and it is defined as cardiomyocyte cell death due to a lack of oxygen supply. Such a temporary absence of oxygen supply, or ischemia, leads to extensive cardiomyocyte cell death in the affected myocardium. Notably, reactive oxygen species are generated during the reperfusion process, driving a novel wave of cell death. Consequently, the inflammatory process starts, followed by fibrotic scar formation. Limiting inflammation and resolving the fibrotic scar are essential biological processes with respect to providing a favorable environment for cardiac regeneration that is only achieved in a limited number of species. Distinct inductive signals and transcriptional regulatory factors are key components that modulate cardiac injury and regeneration. Over the last decade, the impact of non-coding RNAs has begun to be addressed in many cellular and pathological processes including myocardial infarction and regeneration. Herein, we provide a state-of-the-art review of the current functional role of diverse non-coding RNAs, particularly microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), in different biological processes involved in cardiac injury as well as in distinct experimental models of cardiac regeneration.

Extracellular Vesicles as Drug Delivery Systems in Organ Transplantation: The Next Frontier

Extracellular vesicles are lipid bilayer-delimited nanoparticles excreted into the extracellular space by all cells. They carry a cargo rich in proteins, lipids and DNA, as well as a full complement of RNA species, which they deliver to recipient cells to induce downstream signalling, and they play a key role in many physiological and pathological processes. There is evidence that native and hybrid EVs may be used as effective drug delivery systems, with their intrinsic ability to protect and deliver a functional cargo by utilising endogenous cellular mechanisms making them attractive as therapeutics. Organ transplantation is the gold standard for treatment for suitable patients with end-stage organ failure. However, significant challenges still remain in organ transplantation; prevention of graft rejection requires heavy immunosuppression and the lack of donor organs results in a failure to meet demand, as manifested by growing waiting lists. Pre-clinical studies have demonstrated the ability of EVs to prevent rejection in transplantation and mitigate ischemia reperfusion injury in several disease models. The findings of this work have made clinical translation of EVs possible, with several clinical trials actively recruiting patients. However, there is much to be uncovered, and it is essential to understand the mechanisms behind the therapeutic benefits of EVs. Machine perfusion of isolated organs provides an unparalleled platform for the investigation of EV biology and the testing of the pharmacokinetic and pharmacodynamic properties of EVs. This review classifies EVs and their biogenesis routes, and discusses the isolation and characterisation methods adopted by the international EV research community, before delving into what is known about EVs as drug delivery systems and why organ transplantation represents an ideal platform for their development as drug delivery systems.

Extracellular Vesicles and Ischemic Cardiovascular Diseases

Characterized by coronary artery obstruction or stenosis, ischemic cardiovascular diseases as advanced stages of coronary heart diseases commonly lead to left ventricular aneurysm, ventricular septal defect, and mitral insufficiency. Extracellular vesicles (EVs) secreted by diverse cells in the body exert roles in cell-cell interactions and intrinsic cellular regulations. With a lipid double-layer membrane and biological components such as DNA, protein, mRNA, microRNAs (miRNA), and siRNA inside, the EVs function as paracrine signaling for the pathophysiology of ischemic cardiovascular diseases and maintenance of the cardiac homeostasis. Unlike stem cell transplantation with the potential tumorigenicity and immunogenicity, the EV-based therapeutic strategy is proposed to satisfy the demand for cardiac repair and regeneration while the circulating EVs detected by a noninvasive approach can act as precious biomarkers. In this chapter, we extensively summarize the cardioprotective functions of native EVs and bioengineered EVs released from stem cells, cardiomyocytes, cardiac progenitor cells (CPCs), endothelial cells, fibroblast, smooth muscle cells, and immune cells. In addition, the potential of EVs as robust molecule biomarkers is discussed for clinical diagnosis of ischemic cardiovascular disease, attributed to the same pathology of EVs as that of their origin. Finally, we highlight EV-based therapy as a biocompatible alternative to direct cell-based therapy for ischemic cardiovascular diseases.

Therapeutics of Extracellular Vesicles in Cardiocerebrovascular and Metabolic Diseases

Extracellular vesicles (EVs) are nanoscale membranous vesicles containing DNA, RNA, lipids, and proteins, which play versatile roles in intercellular communications. EVs are increasingly being recognized as the promising therapeutic agents for many diseases, including cardiocerebrovascular and metabolic diseases, due to their ability to deliver functional and therapeutical molecules. In this chapter, the biological characteristics and functions of EVs are briefly summarized. Importantly, the current state of applying EVs in the prevention and treatment of cardiocerebrovascular and metabolic diseases, including myocardial infarction, atrial fibrillation, myocardial hypertrophy, stroke, diabetes, Alzheimer's disease, fatty liver, obesity, thyroid diseases, and osteoporosis, is discussed. Lastly, the challenges and prospects related to the preclinical and clinical application of EVs receive a particular focus.

Analysis of the Research Hotspot of Exosomes in Cardiovascular Disease: A Bibliometric-based Literature Review

OBJECTIVE

To investigate the current status and development trend of research on exosomes in cardiovascular disease (CVD) using bibliometric analysis and to elucidate trending research topics.

METHODS

Research articles on exosomes in CVD published up to April 2022 were retrieved from the Web of Science database. Data were organized using Microsoft Office Excel 2019. CiteSpace 6.1 and VOSviewer 1.6.18 were used for bibliometric analysis and result visualization.

RESULTS

Overall, 256 original research publications containing 190 fundamental research publications and 66 clinical research publications were included. "Extracellular vesicle" was the most frequent research keyword, followed by "microrna," "apoptosis," and "angiogenesis." Most publications were from China (187, 73.05%), followed by the United States (57, 22.27%), the United Kingdom (7, 2.73%), and Japan (7, 2.73%). A systematic review of the publications revealed that myocardial infarction and stroke were the most popular topics and that exosomes and their contents, such as microRNAs (miRNAs), play positive roles in neuroprotection, inhibition of autophagy and apoptosis, promotion of angiogenesis, and protection of cardiomyocytes.

CONCLUSION

Research on exosomes in CVD has attracted considerable attention, with China having the most published studies. Fundamental research has focused on CVD pathogenesis; exosomes regulate the progression of CVD through biological processes, such as the inflammatory response, autophagy, and apoptosis. Clinical research has focused on biomarkers for CVD; studies on using miRNAs in exosomes as disease markers for diagnosis could become a future trend.

Strategies and challenges for non-viral delivery of non-coding RNAs to the heart

Non-coding RNAs (ncRNAs), such as miRNAs and long non-coding RNAs (lncRNAs) have been reported as regulators of cardiovascular pathophysiology. Their transient effect and diversified mechanisms of action offer a plethora of therapeutic opportunities for cardiovascular diseases (CVDs). However, physicochemical RNA features such as charge, stability, and structural organization hinder efficient on-target cellular delivery. Here, we highlight recent preclinical advances in ncRNA delivery for the cardiovascular system using non-viral approaches. We identify the unmet needs and advance possible solutions towards clinical translation. Finding the optimal delivery vehicle and administration route is vital to improve therapeutic efficacy and safety; however, given the different types of ncRNAs, this may ultimately not be frameable within a one-size-fits-all approach.

A novel therapeutic strategy for alleviating atrial remodeling by targeting exosomal miRNAs in atrial fibrillation

Atrial fibrillation (AF) is one of the most frequent cardiac arrhythmias, and atrial remodeling is related to the progression of AF. Although several therapeutic approaches have been presented in recent years, the continuously increasing mortality rate suggests that more advanced strategies for treatment are urgently needed. Exosomes regulate pathological processes through intercellular communication mediated by microribonucleic acid (miRNA) in various cardiovascular diseases (CVDs). Exosomal miRNAs associated with signaling pathways have added more complexity to an already complex direct cell-to-cell interaction. Exosome delivery of miRNAs is involved in cardiac regeneration and cardiac protection. Recent studies have found that exosomes play a critical role in the diagnosis and treatment of cardiac fibrosis. By improving exosome stability and modifying surface epitopes, specific pharmaceutical agents can be supplied to improve tropism and targeting to cells and tissues in vivo. Exosomes harboring miRNAs may have clinical utility in cell-free therapeutic approaches and may serve as prognostic and diagnostic biomarkers for AF. Currently, limitations challenge pharmaceutic design, therapeutic utility and in vivo targeted delivery to patients. The aim of this article is to review the developmental features of AF associated with exosomal miRNAs and relate them to underlying mechanisms.

Gut-Derived Exosomes Induce Liver Injury After Intestinal Ischemia/Reperfusion by Promoting Hepatic Macrophage Polarization

Liver injury induced by intestinal ischemia/reperfusion (I/R) is accompanied by the polarization of Kupffer cells, which are specialized macrophages located in the liver. However, the causes of hepatic macrophage polarization after intestinal I/R remain unknown. This study investigated whether gut-derived exosomes contribute to the pathogenesis of liver injury triggered by intestinal I/R in a murine model and explored the underlying mechanisms. Intestinal I/R models were established by temporally clamping the superior mesenteric arteries of mice. Exosomes were isolated from the intestinal tissue of mice that underwent intestinal I/R or sham surgery according to a centrifugation-based protocol. Exosomes were co-cultured with RAW 264.7 macrophages or injected intravenously in mice. Liposomal clodronate was administered intraperitoneally to deplete the macrophages. Macrophage polarization was determined by flow cytometry, immunohistochemistry, and quantitative polymerase chain reaction. Liver injury was assessed by histological morphology and increased serum aspartate aminotransferase and alanine aminotransferase levels. Exosomes from mice intestines subjected to I/R (IR-Exo) promoted macrophage activation in vitro. Intravenous injection of IR-Exo caused hepatic M1 macrophage polarization and led to liver injury in mice. Depleting macrophages ameliorated liver injury caused by intestinal I/R or the injection of IR-Exo. Furthermore, inhibiting exosome release improved intestinal injury, liver function, and survival rates of mice subjected to intestinal I/R. Our study provides evidence that gut-derived exosomes induce liver injury after intestinal I/R by promoting hepatic M1 macrophage polarization. Inhibition of exosome secretion could be a therapeutic target for preventing hepatic impairment after intestinal I/R.

Progress in research on the role of exosomal miRNAs in the diagnosis and treatment of cardiovascular diseases

Cardiovascular diseases are the most common diseases threatening the health of the elderly, and the incidence and mortality rates associated with cardiovascular diseases remain high and are increasing gradually. Studies on the treatment and prevention of cardiovascular diseases are underway. Currently, several research groups are studying the role of exosomes and biomolecules incorporated by exosomes in the prevention, diagnosis, and treatment of clinical diseases, including cardiovascular diseases. Now, based on the results of published studies, this review discusses the characteristics, separation, extraction, and identification of exosomes, specifically the role of exosomal miRNAs in atherosclerosis, myocardial injury and infarction, heart failure, aortic dissection, myocardial fibrosis, ischemic reperfusion, atrial fibrillation, and other diseases. We believe that the observations noted in this article will aid in the prevention, diagnosis, and treatment of cardiovascular diseases.

Extracellular vesicles as a novel photosensitive drug delivery system for enhanced photodynamic therapy

Photodynamic therapy (PDT) is a promising non-invasive therapeutic approach that utilizes photosensitizers (PSs) to generate highly reactive oxygen species (ROS), including singlet oxygen, for removal of targeted cells. PDT has been proven efficacious for the treatment of several diseases, including cancer, cardiovascular disease, inflammatory bowel disease, and diabetic ocular disease. However, the therapeutic efficacy of PDT is limited and often accompanied by side effects, largely due to non-specific delivery of PSs beyond the desired lesion site. Over the past decade, despite various nanoparticular drug delivery systems developed have markedly improved the treatment efficacy while reducing the off-target effects of PSs, concerns over the safety and toxicity of synthetic nanomaterials following intravenous administration are raised. Extracellular vesicles (EVs), a type of nanoparticle released from cells, are emerging as a natural drug delivery system for PSs in light of EV's potentially low immunogenicity and biocompatibility compared with other nanoparticles. This review aims to provide an overview of the research progress in PS delivery systems and propose EVs as an alternative PS delivery system for PDT. Moreover, the challenges and future perspectives of EVs for PS delivery are discussed.

Injectable cartilage matrix hydrogel loaded with cartilage endplate stem cells engineered to release exosomes for non-invasive treatment of intervertebral disc degeneration

Low back pain, mainly caused by intervertebral disc degeneration (IVDD), is a common health problem; however, current surgical treatments are less than satisfactory. Thus, it is essential to develop novel non-invasive surgical methods for IVDD treatment. Here, we describe a therapeutic strategy to inhibit IVDD by injecting hydrogels modified with the extracellular matrix of costal cartilage (ECM-Gels) that are loaded with cartilage endplate stem cells (CESCs). After loaded with CESCs overexpressing Sphk2 (Lenti-Sphk2-CESCs) and injected near the cartilage endplate (CEP) of rats in vivo, ECM-Gels produced Sphk2-engineered exosomes (Lenti-Sphk2-Exos). These exosomes penetrated the annulus fibrosus (AF) and transported Sphk2 into the nucleus pulposus cells (NPCs). Sphk2 activated the phosphatidylinositol 3-kinase (PI3K)/p-AKT pathway as well as the intracellular autophagy of NPCs, ultimately ameliorating IVDD. This study provides a novel and efficient non-invasive combinational strategy for IVDD treatment using injectable ECM-Gels loaded with CESCs that express Sphk2 with sustained release of functional exosomes.

Wildfires and extracellular vesicles: Exosomal MicroRNAs as mediators of cross-tissue cardiopulmonary responses to biomass smoke

INTRODUCTION

Wildfires are a threat to public health world-wide that are growing in intensity and prevalence. The biological mechanisms that elicit wildfire-associated toxicity remain largely unknown. The potential involvement of cross-tissue communication via extracellular vesicles (EVs) is a new mechanism that has yet to be evaluated.

METHODS

Female CD-1 mice were exposed to smoke condensate samples collected from the following biomass burn scenarios: flaming peat; smoldering peat; flaming red oak; and smoldering red oak, representing lab-based simulations of wildfire scenarios. Lung tissue, bronchoalveolar lavage fluid (BALF) samples, peripheral blood, and heart tissues were collected 4 and 24 h post-exposure. Exosome-enriched EVs were isolated from plasma, physically characterized, and profiled for microRNA (miRNA) expression. Pathway-level responses in the lung and heart were evaluated through RNA sequencing and pathway analyses.

RESULTS

Markers of cardiopulmonary tissue injury and inflammation from BALF samples were significantly altered in response to exposures, with the greatest changes occurring from flaming biomass conditions. Plasma EV miRNAs relevant to cardiovascular disease showed exposure-induced expression alterations, including miR-150, miR-183, miR-223-3p, miR-30b, and miR-378a. Lung and heart mRNAs were identified with differential expression enriched for hypoxia and cell stress-related pathways. Flaming red oak exposure induced the greatest transcriptional response in the heart, a large portion of which were predicted as regulated by plasma EV miRNAs, including miRNAs known to regulate hypoxia-induced cardiovascular injury. Many of these miRNAs had published evidence supporting their transfer across tissues. A follow-up analysis of miR-30b showed that it was increased in expression in the heart of exposed mice in the absence of changes to its precursor molecular, pri-miR-30b, suggesting potential transfer from external sources (e.g., plasma).

DISCUSSION

This study posits a potential mechanism through which wildfire exposures induce cardiopulmonary responses, highlighting the role of circulating plasma EVs in intercellular and systems-level communication between tissues.

Bioengineering exosomes for treatment of organ ischemia-reperfusion injury

Ischemia-reperfusion (I/R) injury is a leading cause of death worldwide. It arises from blood reflowing after tissue hypoxia induced by ischemia that causes severe damages due to the accumulation of reactive oxygen species and the activation of inflammatory responses. Exosomes are the smallest members of the extracellular vesicles' family, which originate from nearly all eukaryotic cells. Exosomes have a great potential in the treatment of I/R injury either in native or modified forms. Native exosomes are secreted by different cell types, such as stem cells, and contain components such as specific miRNA molecules with tissue protective properties. On the other hand, exosome bioengineering has recently received increased attention in context of current advances in the purification, manipulation, biological characterization, and pharmacological applications. There are various pre-isolation and post-isolation manipulation approaches that can be utilized to increase the circulation half-life of exosomes or the availability of their bioactive cargos in the target site. In this review, the various therapeutic actions of native exosomes in different I/R injury will be discussed first. Exosome bioengineering approaches will then be explained, including pre- and post-isolation manipulation methods, applicability for delivery of bioactive agents to injured tissue, clinical translation issues, and future perspectives.

New Approaches for Enhancement of the Efficacy of Mesenchymal Stem Cell-Derived Exosomes in Cardiovascular Diseases

Cardiovascular diseases (CVDs) remain a major health concern worldwide, where mesenchymal stem cells (MSCs) therapy gives great promise in their management through their regenerative and paracrine actions. In recent years, many studies have shifted from the use of transplanted stem cells to their secreted exosomes for the management of various CVDs and cardiovascular-related diseases including atherosclerosis, stroke, myocardial infarction, heart failure, peripheral arterial diseases, and pulmonary hypertension. In different models, MSC-derived exosomes have shown beneficial outcomes similar to cell therapy concerning regenerative and neovascular actions in addition to their anti-apoptotic, anti-remodeling, and anti-inflammatory actions. Compared with their parent cells, exosomes have also demonstrated several advantages, including lower immunogenicity and no risk of tumor formation. However, the maintenance of stability and efficacy of exosomes after in vivo transplantation is still a major concern in their clinical application. Recently, new approaches have been developed to enhance their efficacy and stability including their preconditioning before transplantation, use of genetically modified MSC-derived exosomes, or their utilization as a targeted drug delivery system. Herein, we summarized the use of MSC-derived exosomes as therapies in different CVDs in addition to recent advances for the enhancement of their efficacy in these conditions.

Challenges facing the clinical translation of cardioprotection: 35 years after the discovery of ischemic preconditioning

Since coronary reperfusion was introduced into clinical practice in the late 1970s, the further translation of several successful animal experiments on cardioprotection into clinical practice has been disappointing to date. Animal experiments are often performed on young, healthy animals lacking the risk factors, co-morbidities and co-medications characteristic of acute myocardial infarction patients. Many hopes were kindled in 1986 when ischemic preconditioning was discovered. However, it is not yet known how long ischemia can last and what is the best modality for additional cardioprotection through conditioning to obtain benefits. There is a lack of experimental studies on the long-term effects of additional cardioprotection, in addition to the reduction in infarct size; in particular, there is a lack of studies on vessel protection, repair, inflammation, remodeling, and mortality. The reproducibility and robustness of experimental studies are often limited by species differences, the role of co-morbidities, vascular damage, inflammatory processes, and co-medications, which are not adequately considered. In particular, inflammatory processes, including NLRP3 inflammasome, play an important role in the long-term effects. Future studies should focus on interventions/agents with robust preclinical data and should recruit patients who truly have the potential to benefit from further cardioprotection. Here we focus on the main mechanisms and targets of cardioprotection during remote conditioning and their alteration by one of the most common co-morbidities, namely diabetes, in which microvascular lesions and inflammatory processes play extremely important roles.

Aging, sex and NLRP3 inflammasome in cardiac ischaemic disease

Experimentally, many strong cardioprotective treatments have been identified in different animal models of acute ischaemia/reperfusion injury (IRI) and coronary artery disease (CAD). However, the translation of these cardioprotective therapies for the benefit of the patients into the clinical scenario has been very disappointing. The reasons for this lack are certainly multiple. Indeed, many confounding factors we must deal in clinical reality, such as aging, sex and inflammatory processes are neglected in many experiments. Due to the pivotal role of aging, sex and inflammation in determining cardiac ischaemic disease, in this review, we take into account age as a modifier of tolerance to IRI in the two sexes, dissecting aging and myocardial reperfusion injury mechanisms and the sex differences in tolerance to IRI. Then we focus on the role of the gut microbiota and the NLRP3 inflammasome in myocardial IRI and on the possibility to consider NLRP3 inflammasome as a potential target in the treatment of CAD in relationship with age and sex. Finally, we consider the cardioprotective mechanisms and cardioprotective treatments during aging in the two sexes.

Plasma-derived extracellular vesicles transfer microRNA-130a-3p to alleviate myocardial ischemia/reperfusion injury by targeting ATG16L1

Extracellular vesicles (EVs) are implicated in myocardial ischemia/reperfusion (I/R) injury as modulators by shuttling diverse cargoes, including microRNAs (miRNAs). The current study was initiated to unravel the potential involvement of plasma-derived EVs carrying miR-130a-3p on myocardial I/R injury. Rats were induced with moderate endoplasmic reticulum stress, followed by isolation of plasma-derived EVs. Then, an I/R rat model and hypoxia/reoxygenation (H/R) cardiomyoblast model were established to simulate a myocardial I/R injury environment where miR-130a-3p was found to be abundantly expressed. miR-130a-3p was confirmed to target and negatively regulate autophagy-related 16-like 1 (ATG16L1) in cardiomyoblasts. Based on a co-culture system, miR-130a-3p delivered by EVs derived from plasma protected H/R-exposed cardiomyoblasts against H/R-induced excessive cardiomyoblast autophagy, inflammation, and damage, improving cardiac dysfunction as well as myocardial I/R-induced cardiac dysfunction and tissue injury. The mechanism underlying the functional role of EVs-loaded miR-130a-3p was found to be dependent on its targeting relation with ATG16L1. The protective action of EV-carried miR-130a-3p was further re-produced in a rat model serving as in vivo validation as evidenced by improved cardiac function, tissue injury, myocardial fibrosis, and myocardial infarction. Collectively, miR-130a-3p shuttled by plasma-derived EVs was demonstrated to alleviate excessive cardiomyoblast autophagy and improve myocardial I/R injury.

Mesenchymal stem cell-derived exosomal microRNA-182-5p alleviates myocardial ischemia/reperfusion injury by targeting GSDMD in mice

Recent evidence indicates that exosomes derived from mesenchymal stem cells (MSCs) confer protective effects against myocardial ischemia/reperfusion (I/R) injury. Exosomes are carriers of potentially protective endogenous molecules, including microRNAs (miRNAs/miRs). The current study set out to test the effects of transferring miR-182-5p from MSC-derived exosomes into myocardial cells on myocardial I/R injury. First, an I/R mouse model was developed by left anterior descending coronary artery occlusion, and myocardial cells were exposed to hypoxia/reoxygenation (H/R) for in vitro I/R model establishment. Loss- and gain-of-function experiments of miR-182-5p and GSDMD were conducted to explore the effects of miR-182-5p via MSC-derived exosomes on cell pyroptosis and viability. GSDMD was robustly expressed in I/R-injured myocardial tissues and H/R-exposed myocardial cells. GSDMD upregulation promoted H/R-induced myocardial cell pyroptosis and reduced viability, corresponding to increased lactate dehydrogenase release, reactive oxygen species production, and pyroptosis. A luciferase assay demonstrated GSDMD as a target of miR-182-5p. In addition, exosomal miR-182-5p was found to diminish GSDMD-dependent cell pyroptosis and inflammation induced by H/R. Furthermore, MSC-derived exosomes carrying miR-182-5p improved cardiac function and reduced myocardial infarction, accompanied with reduced inflammation and cell pyroptosis in vivo. Taken together, our findings suggest a cardioprotective effect of exosomal miR-182-5p against myocardial I/R injury, shedding light on an attractive therapeutic strategy.

Remote ischemic preconditioning protects against cerebral ischemia injury in rats by upregulating miR-204-5p and activating the PINK1/Parkin signaling pathway

Remote ischemic preconditioning (RiPC) is the process where preconditioning ischemia protects the organs against the subsequent index ischemia. RiPC is a protective method for brain damage. This study is to explore the effect and mechanism of RiPC in cerebral ischemia injury in rats through regulation of miR-204-5p/BRD4 expression. Middle cerebral artery occlusion (MCAO) rat model and glucose deprivation (OGD) neuron model were established. The effect of RiPC on neurological deficits, cerebral infarct size, autophagy marker, inflammatory cytokines and apoptosis was evaluated. miR-204-5p expression was analyzed using RT-qPCR, and then downregulated using miR-204-5p antagomir to estimate its effect on MCAO rats. The downstream mechanism of miR-204-5p was explored. RiPC promoted autophagy, reduced cerebral infarct volume and neurological deficit score, and alleviated apoptosis and cerebral ischemia injury in rats, with no significant effects on healthy rat brains. RiPC up-regulated miR-204-5p expression in MCAO rats. miR-204-5p knockdown partially reversed the effect of RiPC. RiPC promoted autophagy in OGD cells, and attenuated inflammation and apoptosis. miR-204-5p targeted BRD4, which partially reversed the effect of miR-204-5p on OGD cells. RiPC activated the PINK1/Parkin pathway via the miR-204-5p/BRD4 axis. In conclusion, RiPC activated the PINK1/Parkin pathway and prevented cerebral ischemia injury by up-regulating miR-204-5p and inhibiting BRD4.

The Role of Plasma Extracellular Vesicles in Remote Ischemic Conditioning and Exercise-Induced Ischemic Tolerance

Ischemic conditioning and exercise have been suggested for protecting against brain ischemia-reperfusion injury. However, the endogenous protective mechanisms stimulated by these interventions remain unclear. Here, in a comprehensive translational study, we investigated the protective role of extracellular vesicles (EVs) released after remote ischemic conditioning (RIC), blood flow restricted resistance exercise (BFRRE), or high-load resistance exercise (HLRE). Blood samples were collected from human participants before and at serial time points after intervention. RIC and BFRRE plasma EVs released early after stimulation improved viability of endothelial cells subjected to oxygen-glucose deprivation. Furthermore, post-RIC EVs accumulated in the ischemic area of a stroke mouse model, and a mean decrease in infarct volume was observed for post-RIC EVs, although not reaching statistical significance. Thus, circulating EVs induced by RIC and BFRRE can mediate protection, but the in vivo and translational effects of conditioned EVs require further experimental verification.

Traditional Chinese Medicine Shen-Yuan-Dan (SYD) Improves Hypoxia-Induced Cardiomyocyte Apoptosis in Neonatal Rats by Upregulating miR-24/Bim Pathway

Background: Acute myocardial infarction (AMI) is the leading cause of malignant arrhythmia, heart failure, and sudden death. However, safe and effective drugs for the treatment of AMI are unavailable to date. The present study aimed to investigate the role of traditional Chinese medicine shen-yuan-dan (SYD) in hypoxia-induced cardiomyocyte apoptosis in neonatal rats. In addition, the study explored the possible mechanism through which SYD could reduce myocardial ischemia apoptosis and regulate the expression of the miR-24/Bim pathway. Methods: Hypoxia-induced neonatal rat cardiomyocytes were used for the experiments. These cardiomyocytes were transfected with an miR-24 mimic and an miR-24 inhibitor and then cocultured with SYD-containing serum. MTT and lactate dehydrogenase (LDH) assays, AnnexinV/PI double staining, flow cytometry, and TUNEL staining were used to determine the cell viability and apoptosis under hypoxic conditions. Furthermore, the expression level of Bim in the hypoxia-induced cardiomyocytes was determined through western blotting and quantitative real-time polymerase chain reaction. Results: After 48 h of hypoxia, LDH and creatine phosphokinase (CPK) activities increased, cell viability decreased, and miR-24 expression upregulated in the cardiomyocytes. SYD alleviated hypoxia-induced cardiomyocyte injury, decreased LDH and CPK activities, increased cell viability, and reduced apoptosis in the neonatal rat cardiomyocytes. Moreover, SYD could upregulate miR-24 expression and downregulate Bim expression. Upregulation of miR-24 expression significantly enhanced the effect of SYD, thereby improving myocardial cell apoptosis. Dual-luciferase reporter assay and western blot analysis confirmed that Bim was a direct target of miR-24. Conclusion: SYD treatment reduces hypoxia-induced myocardial apoptosis by upregulating miR-24 expression. This study provides new insights into the molecular mechanism underlying the therapeutic potential of SYD in promoting the recovery of myocardial function and delaying the incidence of heart failure.

Exosomal miR-17-3p Alleviates Programmed Necrosis in Cardiac Ischemia/Reperfusion Injury by Regulating TIMP3 Expression

Objective

Myocardial ischemia/reperfusion (I/R) injury can aggravate myocardial injury. Programmed necrosis plays a crucial role in this injury. However, the role of exosomal miRNAs in myocardial I/R injury remains unclear. Therefore, this study is aimed at exploring the function and mechanism of exosomal miR-17-3p in myocardial I/R injury.

Methods

The myocardial I/R injury animal model was established in C57BL/6 mice. Exosomes were identified using transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and Western blotting. Programmed necrosis was detected by PI staining. Heart function and myocardial infarct size were evaluated using echocardiography and triphenyl tetrazolium chloride (TTC) staining, respectively. Histopathological changes were visualized by hematoxylin and eosin (H&E) and Masson staining. The regulation of TIMP3 expression by miR-17-3p was verified using a dual-luciferase reporter assay. Lactate dehydrogenase (LDH) and tumor necrosis factor-α (TNF-α) levels were measured by enzyme-linked immunosorbent assays (ELISA). TIMP3 expression was measured by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Western blotting.

Results

We demonstrated that miR-17-3p was significantly downregulated in peripheral blood exosomes after cardiac I/R injury. Further analysis indicated that exosomal miR-17-3p attenuated H₂O₂-induced programmed necrosis in cardiomyocytes in vitro. Moreover, TIMP3 was a target for miR-17-3p. TIMP3 affected H₂O₂-induced programmed necrosis in cardiomyocytes. This effect was modulated by miR-17-3p in vitro. Furthermore, exosomal miR-17-3p greatly alleviated cardiac I/R injury in vivo.

Conclusions

The present study demonstrated that exosomal miR-17-3p alleviated the programmed necrosis associated with cardiac I/R injury by regulating TIMP3 expression. These findings could represent a potential treatment for I/R injury.

Versatile role of miR-24/24-1*/24-2* expression in cancer and other human diseases

MiRNAs (miRs) have been proven to be well-validated therapeutic targets. Emerging evidence has demonstrated that intricate, intrinsic and paradoxical functions of miRs are context-dependent because of their multiple upstream regulators, broad spectrum of downstream molecular targets and distinct expression in various tissues, organs and disease states. Targeted therapy has become an emerging field of research. One key for the development of successful miR-based/targeted therapy is to acquire integrated knowledge of its regulatory network and its association with disease phenotypes to identify critical nodes of the underlying pathogenesis. Herein, we systematically summarized the comprehensive role of miR-24-3p (miR-24), along with its passenger strands miR-24-1-5p* (miR-24-1) and miR-24-2-5p* (miR-24-2), emphasizing their microenvironment, intracellular targets, and associated gene networks and regulatory phenotypes in 18 different cancer types and 13 types of other disorders. MiR-24 targets and regulates numerous genes in various cancer types and enhances the expression of several oncogenes (e.g., cMyc, BCL2 and HIF1), which are challenging in terms of druggability. In contrast, several tumor suppressor proteins (p21 and p53) have been reported to be downregulated by miR-24. MiR-24 also regulates the cell cycle and is associated with numerous cancer hallmarks such as apoptosis, proliferation, metastasis, invasion, angiogenesis, autophagy, drug resistance and other diseases pathogenesis. Overall, miR-24 plays an emerging role in the diagnosis, prognosis and pathobiology of various diseases. MiR-24 is a potential target for targeted therapy in the era of precision medicine, which expands the landscape of targetable macromolecules, including undruggable proteins.