Examining the Paracrine Effects of Exosomes in Cardiovascular Disease and Repair

Tipifarnib Reduces Extracellular Vesicles and Protects From Heart Failure

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Therapeutic potential of exosomes in spermatogenesis regulation and male infertility

BACKGROUND

Spermatogenesis is a fundamental process crucial for male reproductive health and fertility. Exosomes, small membranous vesicles released by various cell types, have recently garnered attention for their role in intercellular communication.

OBJECTIVE

This review aims to comprehensively explore the role of exosomes in regulating spermatogenesis, focusing on their involvement in testicular development and cell-to-cell communication.

METHODS

A systematic examination of literature was conducted to gather relevant studies elucidating the biogenesis, composition, and functions of exosomes in the context of spermatogenesis.

RESULTS

Exosomes play a pivotal role in orchestrating the complex signaling networks required for proper spermatogenesis. They facilitate the transfer of key regulatory molecules between different cell populations within the testes, including Sertoli cells, Leydig cells, and germ cells.

CONCLUSION

The emerging understanding of exosome-mediated communication sheds light on novel mechanisms underlying spermatogenesis regulation. Further research in this area holds promise for insights into male reproductive health and potential therapeutic interventions.

Insight into the Functional Dynamics and Challenges of Exosomes in Pharmaceutical Innovation and Precision Medicine

Of all the numerous nanosized extracellular vesicles released by a cell, the endosomal-originated exosomes are increasingly recognized as potential therapeutics, owing to their inherent stability, low immunogenicity, and targeted delivery capabilities. This review critically evaluates the transformative potential of exosome-based modalities across pharmaceutical and precision medicine landscapes. Because of their precise targeted biomolecular cargo delivery, exosomes are posited as ideal candidates in drug delivery, enhancing regenerative medicine strategies, and advancing diagnostic technologies. Despite the significant market growth projections of exosome therapy, its utilization is encumbered by substantial scientific and regulatory challenges. These include the lack of universally accepted protocols for exosome isolation and the complexities associated with navigating the regulatory environment, particularly the guidelines set forth by the U.S. Food and Drug Administration (FDA). This review presents a comprehensive overview of current research trajectories aimed at addressing these impediments and discusses prospective advancements that could substantiate the clinical translation of exosomal therapies. By providing a comprehensive analysis of both the capabilities and hurdles inherent to exosome therapeutic applications, this article aims to inform and direct future research paradigms, thereby fostering the integration of exosomal systems into mainstream clinical practice.

MicroRNA Nano-Shuttles: Engineering Extracellular Vesicles as a Cutting-Edge Biotechnology Platform for Clinical Use in Therapeutics

Extracellular vesicles (EVs) are nano-sized, membranous transporters of various active biomolecules with inflicting phenotypic capabilities, that are naturally secreted by almost all cells with a promising vantage point as a potential leading drug delivery platform. The intrinsic characteristics of their low toxicity, superior structural stability, and cargo loading capacity continue to fuel a multitude of research avenues dedicated to loading EVs with therapeutic and diagnostic cargos (pharmaceutical compounds, nucleic acids, proteins, and nanomaterials) in attempts to generate superior natural nanoscale delivery systems for clinical application in therapeutics. In addition to their well-known role in intercellular communication, EVs harbor microRNAs (miRNAs), which can alter the translational potential of receiving cells and thus act as important mediators in numerous biological and pathological processes. To leverage this potential, EVs can be structurally engineered to shuttle therapeutic miRNAs to diseased recipient cells as a potential targeted 'treatment' or 'therapy'. Herein, this review focuses on the therapeutic potential of EV-coupled miRNAs; summarizing the biogenesis, contents, and function of EVs, as well as providing both a comprehensive discussion of current EV loading techniques and an update on miRNA-engineered EVs as a next-generation platform piloting benchtop studies to propel potential clinical translation on the forefront of nanomedicine.

C166 EVs potentiate miR cardiac reprogramming via miR-148a-3p

We have demonstrated that directly reprogramming cardiac fibroblasts into new cardiomyocytes via miR combo improves cardiac function in the infarcted heart. However, major challenges exist with delivery and efficacy. During a screening based approach to improve delivery, we discovered that C166-derived EVs were effective delivery agents for miR combo both in vitro and in vivo. In the latter, EV mediated delivery of miR combo induced significant conversion of cardiac fibroblasts into cardiomyocytes (∼20%), reduced fibrosis and improved cardiac function in a myocardial infarction injury model. When compared to lipid-based transfection, C166 EV mediated delivery of miR combo enhanced reprogramming efficacy. Improved reprogramming efficacy was found to result from a miRNA within the exosome: miR-148a-3p. The target of miR-148a-3p was identified as Mdfic. Over-expression and targeted knockdown studies demonstrated that Mdfic was a repressor of cardiomyocyte specific gene expression. In conclusion, we have demonstrated that C166-derived EVs are an effective method for delivering reprogramming factors to cardiac fibroblasts and we have identified a novel miRNA contained within C166-derived EVs which enhances reprogramming efficacy.

Unraveling the Signaling Dynamics of Small Extracellular Vesicles in Cardiac Diseases

Effective intercellular communication is essential for cellular and tissue balance maintenance and response to challenges. Cellular communication methods involve direct cell contact or the release of biological molecules to cover short and long distances. However, a recent discovery in this communication network is the involvement of extracellular vesicles that host biological contents such as proteins, nucleic acids, and lipids, influencing neighboring cells. These extracellular vesicles are found in body fluids; thus, they are considered as potential disease biomarkers. Cardiovascular diseases are significant contributors to global morbidity and mortality, encompassing conditions such as ischemic heart disease, cardiomyopathies, electrical heart diseases, and heart failure. Recent studies reveal the release of extracellular vesicles by cardiovascular cells, influencing normal cardiac function and structure. However, under pathological conditions, extracellular vesicles composition changes, contributing to the development of cardiovascular diseases. Investigating the loading of molecular cargo in these extracellular vesicles is essential for understanding their role in disease development. This review consolidates the latest insights into the role of extracellular vesicles in diagnosis and prognosis of cardiovascular diseases, exploring the potential applications of extracellular vesicles in personalized therapies, shedding light on the evolving landscape of cardiovascular medicine.

The recent advances in cell delivery approaches, biochemical and engineering procedures of cell therapy applied to coronary heart disease

Cell therapy is an important topic in the field of regeneration medicine that is gaining attention within the scientific community. However, its potential for treatment in coronary heart disease (CHD) has yet to be established. Several various strategies, types of cells, routes of distribution, and supporting procedures have been tried and refined to trigger heart rejuvenation in CHD. However, only a few of them result in a real considerable promise for clinical usage. In this review, we give an update on techniques and clinical studies of cell treatment as used to cure CHD that are now ongoing or have been completed in the previous five years. We also highlight the emerging efficacy of stem cell treatment for CHD. We specifically examine and comment on current breakthroughs in cell treatment applied to CHD, including the most effective types of cells, transport modalities, engineering, and biochemical approaches used in this context. We believe the current review will be helpful for the researcher to distill this information and design future studies to overcome the challenges faced by this revolutionary approach for CHD.

Long Non-Coding RNAs (lncRNAs) in Heart Failure: A Comprehensive Review

Heart failure (HF) is a widespread cardiovascular condition that poses significant risks to a wide spectrum of age groups and leads to terminal illness. Although our understanding of the underlying mechanisms of HF has improved, the available treatments still remain inadequate. Recently, long non-coding RNAs (lncRNAs) have emerged as crucial players in cardiac function, showing possibilities as potential targets for HF therapy. These versatile molecules interact with chromatin, proteins, RNA, and DNA, influencing gene regulation. Notable lncRNAs like Fendrr, Trpm3, and Scarb2 have demonstrated therapeutic potential in HF cases. Additionally, utilizing lncRNAs to forecast survival rates in HF patients and distinguish various cardiac remodeling conditions holds great promise, offering significant benefits in managing cardiovascular disease and addressing its far-reaching societal and economic impacts. This underscores the pivotal role of lncRNAs in the context of HF research and treatment.

Circulating exosome-like vesicle and skeletal muscle microRNAs are altered with age and resistance training

The age-related loss of skeletal muscle mass and functionality, known as sarcopenia, is a critical risk factor for morbidity and all-cause mortality. Resistance exercise training (RET) is the primary countermeasure to fight sarcopenia and ageing. Altered intercellular communication is a hallmark of ageing, which is not well elucidated. Circulating extracellular vesicles (EVs), including exosomes, contribute to intercellular communication by delivering microRNAs (miRNAs), which modulate post-translational modifications, and have been shown to be released following exercise. There is little evidence regarding how EVs or EV-miRNAs are altered with age or RET. Therefore, we sought to characterize circulating EVs in young and older individuals, prior to and following a 12-week resistance exercise programme. Plasma EVs were isolated using size exclusion chromatography and ultracentrifugation. We found that ageing reduced circulating expression markers of CD9, and CD81. Using late-passage human myotubes as a model for ageing in vitro, we show significantly lower secreted exosome-like vesicles (ELVs). Further, levels of circulating ELV-miRNAs associated with muscle health were lower in older individuals at baseline but increased following RET to levels comparable to young. Muscle biopsies show similar age-related reductions in miRNA expressions, with largely no effect of training. This is reflected in vitro, where aged myotubes show significantly reduced expression of endogenous and secreted muscle-specific miRNAs (myomiRs). Lastly, proteins associated with ELV and miRNA biogenesis were significantly higher in both older skeletal muscle tissues and aged human myotubes. Together we show that ageing significantly affects ELV and miRNA cargo biogenesis, and release. RET can partially normalize this altered intercellular communication. KEY POINTS: We show that ageing reduces circulating expression of exosome-like vesicle (ELV) markers, CD9 and CD81. Using late-passage human skeletal myotubes as a model of ageing, we show that secreted ELV markers are significantly reduced in vitro. We find circulating ELV miRNAs associated with skeletal muscle health are lower in older individuals but can increase following resistance exercise training (RET). In skeletal muscle, we find altered expression of miRNAs in older individuals, with no effect of RET. Late-passage myotubes also appear to have aberrant production of endogenous myomiRs with lower abundance than youthful counterparts In older skeletal muscle and late-passage myotubes, proteins involved with ELV- and miRNA biogenesis are upregulated.

Human Keratinocytes and Fibroblasts Co-Cultured on Silk Fibroin Scaffolds Exosomally Overrelease Angiogenic and Growth Factors

Objectives: The optimal healing of skin wounds, deep burns, and chronic ulcers is an important clinical problem. Attempts to solve it have been driving the search for skin equivalents based on synthetic or natural polymers. Methods: Consistent with this endeavor, we used regenerated silk fibroin (SF) from Bombyx mori to produce a novel compound scaffold by welding a 3D carded/hydroentangled SF-microfiber-based nonwoven layer (C/H-3D-SFnw; to support dermis engineering) to an electrospun 2D SF nanofiber layer (ESFN; a basal lamina surrogate). Next, we assessed-via scanning electron microscopy, attenuated total reflectance Fourier transform infrared spectroscopy, differential scanning calorimetry, mono- and co-cultures of HaCaT keratinocytes and adult human dermal fibroblasts (HDFs), dsDNA assays, exosome isolation, double-antibody arrays, and angiogenesis assays-whether the C/H-3D-SFnws/ESFNs would allow the reconstitution of a functional human skin analog in vitro. Results: Physical analyses proved that the C/H-3D-SFnws/ESFNs met the requirements for human soft-tissue-like implants. dsDNA assays revealed that co-cultures of HaCaTs (on the 2D ESFN surface) and HDFs (inside the 3D C/H-3D-SFnws) grew more intensely than did the respective monocultures. Double-antibody arrays showed that the CD9⁺/CD81⁺ exosomes isolated from the 14-day pooled growth media of HDF and/or HaCaT mono- or co-cultures conveyed 35 distinct angiogenic/growth factors (AGFs). However, versus monocultures' exosomes, HaCaT/HDF co-cultures' exosomes (i) transported larger amounts of 15 AGFs, i.e., PIGF, ANGPT-1, bFGF, Tie-2, Angiogenin, VEGF-A, VEGF-D, TIMP-1/-2, GRO-α/-β/-γ, IL-1β, IL-6, IL-8, MMP-9, and MCP-1, and (ii) significantly more strongly stimulated human dermal microvascular endothelial cells to migrate and assemble tubes/nodes in vitro. Conclusions: Our results showed that both cell-cell and cell-SF interactions boosted the exosomal release of AGFs from HaCaTs/HDFs co-cultured on C/H-3D-SFnws/ESFNs. Hence, such exosomes are an asset for prospective clinical applications as they advance cell growth and neoangiogenesis and consequently graft take and skin healing. Moreover, this new integument analog could be instrumental in preclinical and translational studies on human skin pathophysiology and regeneration.

Targeting non-coding RNAs in sEVs: The biological functions and potential therapeutic strategy of diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM) is defined as abnormalities in myocardial structure and function in the setting of diabetes and in the absence of cardiovascular diseases, such as coronary artery disease, hypertension, and valvular heart disease. DCM is one of the leading causes of mortality in patients with diabetes. However, the underlying pathogenesis of DCM has not been fully elucidated. Recent studies have revealed that non-coding RNAs (ncRNAs) in small extracellular vesicles (sEVs) are closely associated with DCM and may act as potential diagnostic and therapeutic targets. Here, we introduced the role of sEV-ncRNAs in DCM, summarized the current therapeutic advancements and limitations of sEV-related ncRNAs against DCM, and discussed their potential improvement.

Lipid Nanoparticles Deliver the Therapeutic VEGFA mRNA In Vitro and In Vivo and Transform Extracellular Vesicles for Their Functional Extensions

Lipid nanoparticles (LNPs) are currently used to transport functional mRNAs, such as COVID-19 mRNA vaccines. The delivery of angiogenic molecules, such as therapeutic VEGF-A mRNA, to ischemic tissues for producing new blood vessels is an emerging strategy for the treatment of cardiovascular diseases. Here, the authors deliver VEGF-A mRNA via LNPs and study stoichiometric quantification of their uptake kinetics and how the transport of exogenous LNP-mRNAs between cells is functionally extended by cells' own vehicles called extracellular vesicles (EVs). The results show that cellular uptake of LNPs and their mRNA molecules occurs quickly, and that the translation of exogenously delivered mRNA begins immediately. Following the VEGF-A mRNA delivery to cells via LNPs, a fraction of internalized VEGF-A mRNA is secreted via EVs. The overexpressed VEGF-A mRNA is detected in EVs secreted from three different cell types. Additionally, RNA-Seq analysis reveals that as cells' response to LNP-VEGF-A mRNA treatment, several overexpressed proangiogenic transcripts are packaged into EVs. EVs are further deployed to deliver VEGF-A mRNA in vitro and in vivo. Upon equal amount of VEGF-A mRNA delivery via three EV types or LNPs in vitro, EVs from cardiac progenitor cells are the most efficient in promoting angiogenesis per amount of VEGF-A protein produced. Intravenous administration of luciferase mRNA shows that EVs could distribute translatable mRNA to different organs with the highest amounts of luciferase detected in the liver. Direct injections of VEGF-A mRNA (via EVs or LNPs) into mice heart result in locally produced VEGF-A protein without spillover to liver and circulation. In addition, EVs from cardiac progenitor cells cause minimal production of inflammatory cytokines in cardiac tissue compared with all other treatment types. Collectively, the data demonstrate that LNPs transform EVs as functional extensions to distribute therapeutic mRNA between cells, where EVs deliver this mRNA differently than LNPs.

Exosomes mediated fibrogenesis in dilated cardiomyopathy through a MicroRNA pathway

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

Matrix-Bound Nanovesicles: What Are They and What Do They Do?

Over the past 50 years, several different types of extracellular vesicles have been discovered including exosomes, microvesicles, and matrix vesicles. These vesicles are secreted by cells for specific purposes and contain cargo such as microRNA, cytokines, and lipids. A novel extracellular vesicle, the matrix-bound nanovesicle (MBV), has been recently discovered. The MBV is similar to the microvesicle, however, it is attached to the extracellular matrix, instead of being secreted. This review compares MBVs to other types of extracellular vesicles to try and better understand their origin and function. Further, this review will explain various extracellular vesicle isolation methods and how these can be used for MBVs and summarize characterization of MBV cargo such as microRNA, proteins, and lipids. Lastly, we will summarize the effects of MBVs on cells. MBVs are a novel class of extracellular vesicles that hold great promise as a platform for delivery of targeted gene and drug therapeutics.

Edible plant extracellular vesicles: An emerging tool for bioactives delivery

The extracellular vesicles (EVs) in edible food have a typical saucer-like structure and are nanoparticles released by numerous cells. They have different components and interact with other biological samples in diverse ways. Therefore, these nanoparticles could be used to develop bioactives delivery nanoplatforms and anti-inflammatory treatments to meet the stringent demands of current clinical challenges. This review aims to summarize current researches into EVs from edible plants, particularly those that can protect siRNAs or facilitate drug transportation. We will discuss their isolation, characterization and functions, their regulatory effects under various physiological and pathological conditions, and their immune regulation, anti-tumor, regeneration, and anti-inflammatory effects. We also review advances in their potential application as bioactives carriers, and medicinal and edible plants that change their EVs compositions during disease to achieve a therapy propose. It is expected that future research on plant-derived EVs will considerably expand their application.

Exosomes form tunneling nanotubes (TUNTs) in the blood-brain barrier: a nano-anatomical perspective of barrier genesis

The blood-brain barrier (BBB) is a robust interface between the blood and the central nervous system. Barrier type endothelium is able to limit paracellular (PC) movement, relegating molecular flux to the transendothelial pathways of brain endothelial cells (BECs). It is, therefore, apparent that any leakage via the PC shunts would effectively nullify the regulation of molecular flux across the transcellular pathways. The application of higher-resolution scanning electron microscopy (HR-SEM) illuminates the heterogenous, morphological profile that exists on the surface of BEC membranes and the relationship between these ultrastructures during the molecular construction of the PC space between adjacent BECs. In this study developing BEC monolayers were grown on mixed, cellulose esters insert membranes in a bicameral system. BEC monolayers were fixed in 2.5% glutaraldehyde, hydrated, critically dried, and sputter-coated, for imaging utilizing HR-SEM. This study, for the first time, showed membrane-bound exosomes were attached to the plasma membrane surfaces of the BECs. The exosomes were characterized as small membrane-bound, nano-sized exosomes (30–300 nm). Based on their membrane morphology and anatomical structure, exosomes appear to possess two distinct functions, namely: paracrine secretion and nanotube construction between adjacent BECs, during in vitro barrier genesis. The HR-SEM micrographs in conjunction with the Tipifarnib inhibition of exosome formation, suggests that brain capillary endothelial exosomes play a prominent role in the bilateral signaling, which contribute to the regulation of the permeability of the BBB. Given that blood-brain barrier permeability has been implicated in the progression of many neurodegenerative pathologies, the role of these exosomes and TUNTs posits the capacity of these structures to exacerbate neuropathologies that implicate BBB permeability. These findings could lead to the development of novel treatment interventions and moreover, the characterization of BBB exosomes may be a reliable target for identifying therapeutic biomarkers in neurodegenerative disease. Conversely, the presence of BBB exosomes raises a critical enterprise to target the exosome-induced nanotubes as a vehicle for transferring therapeutic treatments across the BBB.

De novo DNA methylation induced by circulating extracellular vesicles from acute coronary syndrome patients

BACKGROUND AND AIMS

DNA methylation is associated with gene silencing, but its clinical role in cardiovascular diseases (CVDs) remains to be elucidated. We hypothesized that extracellular vesicles (EVs) may carry epigenetic changes, showing themselves as a potentially valuable non-invasive diagnostic liquid biopsy. We isolated and characterized circulating EVs of acute coronary syndrome (ACS) patients and assessed their role on DNA methylation in epigenetic modifications.

METHODS

EVs were recovered from plasma of 19 ACS patients and 50 healthy subjects (HS). Flow cytometry, qRT-PCR, and Western blot (WB) were performed to evaluate both intra-vesicular and intra-cellular signals. ShinyGO, PANTHER, and STRING tools were used to perform GO and PPI network analyses.

RESULTS

ACS-derived EVs showed increased levels of DNA methyltransferases (DNMTs) (p<0.001) and Ten-eleven translocation (TET) genes reduction. Specifically, de novo methylation transcripts, as DNMT3A and DNMT3B, were significantly increased in plasma ACS-EVs. DNA methylation analysis on PBMCs from healthy donors treated with HS- and ACS-derived EVs showed an important role of DNMTs carried by EVs. PPI network analysis evidenced that ACS-EVs induced changes in PBMC methylome. In the most enriched subnetwork, the hub gene SRC was connected to NOTCH1, FOXO3, CDC42, IKBKG, RXRA, DGKG, BAIAP2 genes that were showed to have many molecular effects on various cell types into onset of several CVDs. Modulation in gene expression after ACS-EVs treatment was confirmed for SRC, NOTCH1, FOXO3, RXRA, DGKG and BAIAP2 (p<0.05).

CONCLUSIONS

Our data showed an important role for ACS-derived EVs in gene expression modulation through de novo DNA methylation signals, and modulating signalling pathways in target cells.

Circulating Exosome Cargoes Contain Functionally Diverse Cancer Biomarkers: From Biogenesis and Function to Purification and Potential Translational Utility

Although diagnostic and therapeutic treatments of cancer have tremendously improved over the past two decades, the indolent nature of its symptoms has made early detection challenging. Thus, inter-disciplinary (genomic, transcriptomic, proteomic, and lipidomic) research efforts have been focused on the non-invasive identification of unique "silver bullet" cancer biomarkers for the design of ultra-sensitive molecular diagnostic assays. Circulating tumor biomarkers, such as CTCs and ctDNAs, which are released by tumors in the circulation, have already demonstrated their clinical utility for the non-invasive detection of certain solid tumors. Considering that exosomes are actively produced by all cells, including tumor cells, and can be found in the circulation, they have been extensively assessed for their potential as a source of circulating cell-specific biomarkers. Exosomes are particularly appealing because they represent a stable and encapsulated reservoir of active biological compounds that may be useful for the non-invasive detection of cancer. T biogenesis of these extracellular vesicles is profoundly altered during carcinogenesis, but because they harbor unique or uniquely combined surface proteins, cancer biomarker studies have been focused on their purification from biofluids, for the analysis of their RNA, DNA, protein, and lipid cargoes. In this review, we evaluate the biogenesis of normal and cancer exosomes, provide extensive information on the state of the art, the current purification methods, and the technologies employed for genomic, transcriptomic, proteomic, and lipidomic evaluation of their cargoes. Our thorough examination of the literature highlights the current limitations and promising future of exosomes as a liquid biopsy for the identification of circulating tumor biomarkers.

Human Heart Anoxia and Reperfusion Tissue (HEART) Model for the Rapid Study of Exosome Bound miRNA Expression As Biomarkers for Myocardial Infarction

Current biomarkers for myocardial infarction (MI) diagnosis are typically late markers released upon cell death, incapable of distinguishing between ischemic and reperfusion injury and can be symptoms of other pathologies. Circulating microRNAs (miRNAs) have recently been proposed as alternative biomarkers for MI diagnosis; however, detecting the changes in the human cardiac miRNA profile during MI is extremely difficult. Here, to study the changes in miRNA levels during acute MI, a heart-on-chip model with a cardiac channel, containing human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes in human heart decellularized matrix and collagen, and a vascular channel, containing hiPSC-derived endothelial cells, is developed. This model is exposed to anoxia followed by normoxia to mimic ischemia and reperfusion, respectively. Using a highly sensitive miRNA biosensor that the authors developed, the exact same increase in miR-1, miR-208b, and miR-499 levels in the MI-on-chip and the time-matched human blood plasma samples collected before and after ischemia and reperfusion, is shown. That the surface marker profile of exosomes in the engineered model changes in response to ischemic and reperfusion injury, which can be used as biomarkers to detect MI, is also shown. Hence, the MI-on-chip model developed here can be used in biomarker discovery.

Biomimetic Design of Artificial Hybrid Nanocells for Boosted Vascular Regeneration in Ischemic Tissues

Restoration of sufficient blood supply for the treatment of ischemia remains a significant scientific and clinical challenge. Here, a cell-like nanoparticle delivery technology is introduced that is capable of recapitulating multiple cell functions for the spatiotemporal triggering of vascular regeneration. Specifically, a copper-containing protein is successfully prepared using a recombinant protein scaffold based on a de novo design strategy, which facilitates the timely release of nitric oxide and improved accumulation of particles within ischemic tissues. Through closely mimicking physiological cues, the authors demonstrate the benefits of bioactive factors secreted from hypoxic stem cells on promoting angiogenesis. Following this cell-mimicking manner, artificial hybrid nanosized cells (Hynocell) are constructed by integrating the hypoxic stem cell secretome into nanoparticles with surface coatings of cell membranes fused with copper-containing protein. The Hynocell, hybridized with different cell-derived components, provides synergistic effects on targeting ischemic tissues and promoting vascular regeneration in acute hindlimb ischemia and acute myocardial infarction models. This study offers new insights into the utilization of nanotechnology to potentiate the development of cell-free therapeutics.

Extracellular Vesicles Secreted by Corneal Myofibroblasts Promote Corneal Epithelial Cell Migration

Corneal epithelial wound healing is a multifaceted process that encompasses cell proliferation, migration, and communication from the corneal stroma. Upon corneal injury, bidirectional crosstalk between the epithelium and stroma via extracellular vesicles (EVs) has been reported. However, the mechanisms by which the EVs from human corneal keratocytes (HCKs), fibroblasts (HCFs), and/or myofibroblasts (HCMs) exert their effects on the corneal epithelium remain unclear. In this study, HCK-, HCF-, and HCM-EVs were isolated and characterized, and human corneal epithelial (HCE) cell migration was assessed in a scratch assay following PKH26-labeled HCK-, HCF-, or HCM-EV treatment. HCE cells proliferative and apoptotic activity following EV treatment was assessed. HCF-/HCM-EVs were enriched for CD63, CD81, ITGAV, and THBS1 compared to HCK-EV. All EVs were negative for GM130 and showed minimal differences in biophysical properties. At the proteomic level, we showed HCM-EV with a log >two-fold change in CXCL6, CXCL12, MMP1, and MMP2 expression compared to HCK-/HCF-EVs; these proteins are associated with cellular movement pathways. Upon HCM-EV treatment, HCE cell migration, velocity, and proliferation were significantly increased compared to HCK-/HCF-EVs. This study concludes that the HCM-EV protein cargo influences HCE cell migration and proliferation, and understanding these elements may provide a novel therapeutic avenue for corneal wound healing.

Injection-Free Delivery of MSC-Derived Extracellular Vesicles for Myocardial Infarction Therapeutics

As emerging therapeutic factors, extracellular vesicles (EVs) offer significant potential for myocardial infarction (MI) treatment. Current delivery approaches for EVs involve either intra-myocardial or intravenous injection, where both have inherent limitations for downstream clinical applications such as secondary tissue injury and low delivery efficiency. Herein, an injection-free approach for delivering EVs onto the heart surface to treat MI is proposed. By spraying a mixture of EVs, gelatin methacryloyl (GelMA) precursors, and photoinitiators followed by visible light irradiation for 30 s, EVs are physically entrapped within the GelMA hydrogel network covering the surface of the heart, resulting in an enhanced retention rate. Moreover, EVs are gradually released from the hydrogel network through a combination of diffusion and/or enzymatic degradation of the hydrogel, and they are effectively taken up by the sprayed tissue area. More importantly, the released EVs further migrate deep into myocardium tissue, which exerts an improved therapeutic effect. In an MI-induced mice model, the group treated with EVs-laden GelMA hydrogels shows significant recovery in cardiac function after 4 weeks. The work demonstrates a new strategy for delivering EVs into cardiac tissues for MI treatment in a localized manner with high retention.

Methodologies to Isolate and Purify Clinical Grade Extracellular Vesicles for Medical Applications

The use of extracellular vesicles (EV) in nano drug delivery has been demonstrated in many previous studies. In this study, we discuss the sources of extracellular vesicles, including plant, salivary and urinary sources which are easily available but less sought after compared with blood and tissue. Extensive research in the past decade has established that the breadth of EV applications is wide. However, the efforts on standardizing the isolation and purification methods have not brought us to a point that can match the potential of extracellular vesicles for clinical use. The standardization can open doors for many researchers and clinicians alike to experiment with the proposed clinical uses with lesser concerns regarding untraceable side effects. It can make it easier to identify the mechanism of therapeutic benefits and to track the mechanism of any unforeseen effects observed.

Impact of the Main Cardiovascular Risk Factors on Plasma Extracellular Vesicles and Their Influence on the Heart's Vulnerability to Ischemia-Reperfusion Injury

The majority of cardiovascular deaths are associated with acute coronary syndrome, especially ST-elevation myocardial infarction. Therapeutic reperfusion alone can contribute up to 40 percent of total infarct size following coronary artery occlusion, which is called ischemia-reperfusion injury (IRI). Its size depends on many factors, including the main risk factors of cardiovascular mortality, such as age, sex, systolic blood pressure, smoking, and total cholesterol level as well as obesity, diabetes, and physical effort. Extracellular vesicles (EVs) are membrane-coated particles released by every type of cell, which can carry content that affects the functioning of other tissues. Their role is essential in the communication between healthy and dysfunctional cells. In this article, data on the variability of the content of EVs in patients with the most prevalent cardiovascular risk factors is presented, and their influence on IRI is discussed.

Proteomic basis of modulation of postischemic fibrosis by MSC exosomes

After an ischemic event, there is activation of fibroblasts leading to scar formation. It is critical to limit the profibrotic remodeling and activate the reparative remodeling phase to limit cardiac diastolic dysfunction. Mesenchymal stem cell (MSC) exosomes offer significant protection against ischemia-related systolic dysfunction. Here, we studied if MSC exosomes would offer protection against profibrotic events in mouse hearts subjected to acute ischemia [1 h left coronary artery (LCA) occlusion] or chronic ischemia (7 days LCA occlusion). After acute ischemia, there was activation of inflammatory signals, more in the peri-infarct than in the infarct area, in the saline (vehicle)-treated mice. At the same time, there was expression of cardiac remodeling signals (vimentin, collagens-1 and -3, and fibronectin), more in the infarct area. Treatment with MSC exosomes before LCA ligation suppressed inflammatory signals during acute and chronic ischemia. Furthermore, exosome treatment promoted pro-reparative cardiac extracellular matrix (ECM) remodeling in both infarct and peri-infarct areas by suppressing fibronectin secretion and by modulating collagen secretion to reduce fibrotic scar formation through altered cellular signaling pathways. Proteomics study revealed intense expression of IL-1β and activation of profibrotic signals in the saline-treated hearts and their suppression in MSC exosome-treated hearts. To our knowledge, this is the first report on the infarct and peri-infarct area proteomics of ischemic mice hearts to explain MSC exosome-mediated suppression of scar formation in the ischemic mouse hearts.

Periodontal ligament fibroblast-derived exosomes induced by compressive force promote macrophage M1 polarization via Yes-associated protein

OBJECTIVES

This study aimed to investigate the biological roles and mechanisms of compressive force-stimulated periodontal ligament fibroblasts (PDLFs) on polarization of macrophages DESIGN: PDLFs were stimulated with or without static compressive force, and then conditioned medium, high-molecular weight proteins and low-molecular weight proteins were collected to treat THP-1 macrophages. RT-qPCR and flow cytometric analysis were used to evaluate the polarization of macrophages. Exosomes were isolated by ultracentrifugation method and identified via transmission electron microscopy, western-blot and nano-tracking analysis. The protein level of Yes-Associated Protein (YAP) contained in exosomes was detected by western blot. GW4869 and Verteporfin were used to inhibit exosome secretion and YAP- TEA domain transcription factor (TEAD) interaction respectively.

RESULTS

Exosomes were successfully purified from PDLFs and could be efficiently incorporated into THP-1 macrophages. conditioned medium, HMW proteins and exosomes derived from compressive force-treated PDLFs significantly induce M1 polarization of macrophages. While inhibiting exosomes secretion by GW4869 treatment eliminated the inductive effect. YAP target genes, connective tissue growth factor (CTGF) and cysteine-rich angiogenic inducer 61 (CYR61) were upregulated in macrophages when treated with exosomes derived from compressive force-treated PDLFs (F-Exo). YAP level was elevated in the F-Exo. When macrophages were treated with Verteporfin, expression of YAP target genes and M1 polarization were significantly downregulated.

CONCLUSION

These results suggested that exosomes derived from compressive force-treated PDLFs promoted the M1 polarization of the THP-1 macrophages. The elevated level of YAP in the exosomes may be a critical factor for this response.

Agony of choice: How anesthetics affect the composition and function of extracellular vesicles

The choice of the anesthetic regime is suggested to affect clinical outcomes following major surgery. Propofol was shown to exert beneficial effects on different cancer outcomes, while volatile anesthetics may be favorable in cardiac surgery. Recently, extracellular vesicles (EVs) were discovered as essential signal mediators in physiological and pathophysiological processes including carcinogenesis and metastasis. Furthermore, depending on their cell source, EVs fulfill therapeutic functions. In addition to extracorporally produced EVs, appropriate systemic intervention such as remote ischemic preconditioning (RIPC) is considered to promote endogenous release of therapeutically active EVs to mediate cardioprotective effects. EVs are assembled in cell-type specific manners and the composition of EVs is not only affected by the disease, but also by the applied anesthetic of anesthetized patients. Here, we compare known impacts of anesthetic agents on outcomes in cancer surgery and cardioprotection and link these effects to the composition and therapeutic potential of EVs.

The Application Potential and Advance of Mesenchymal Stem Cell-Derived Exosomes in Myocardial Infarction

Myocardial infarction (MI) is a devastating disease with high morbidity and mortality caused by the irreversible loss of functional cardiomyocytes and heart failure (HF) due to the restricted blood supply. Mesenchymal stem cells (MSCs) have been emerging as lead candidates to treat MI and subsequent HF mainly through secreting multitudinous factors of which exosomes act as the most effective constituent to boost the repair of heart function through carrying noncoding RNAs and proteins. Given the advantages of higher stability in the circulation, lower toxicity, and controllable transplantation dosage, exosomes have been described as a wonderful and promising cell-free treatment method in cardiovascular disease. Nowadays, MSC-derived exosomes have been proposed as a promising therapeutic approach to improve cardiac function and reverse heart remodeling. However, exosomes' lack of modification cannot result in desired therapeutic effect. Hence, optimized exosomes can be developed via various engineering methods such as pharmacological compound preconditioned MSCs, genetically modified MSCs, or miRNA-loaded exosomes and peptide tagged exosomes to improve the targeting and therapeutic effects of exosomes. The biological characteristics, therapeutic potential, and optimizing strategy of exosomes will be described in our review.

Cellular crosstalk in cardioprotection: Where and when do reactive oxygen species play a role?

A well-balanced intercellular communication between the different cells within the heart is vital for the maintenance of cardiac homeostasis and function. Despite remarkable advances on disease management and treatment, acute myocardial infarction remains the major cause of morbidity and mortality worldwide. Gold standard reperfusion strategies, namely primary percutaneous coronary intervention, are crucial to preserve heart function. However, reestablishment of blood flow and oxygen levels to the infarcted area are also associated with an accumulation of reactive oxygen species (ROS), leading to oxidative damage and cardiomyocyte death, a phenomenon termed myocardial reperfusion injury. In addition, ROS signaling has been demonstrated to regulate multiple biological pathways, including cell differentiation and intercellular communication. Given the importance of cell-cell crosstalk in the coordinated response after cell injury, in this review, we will discuss the impact of ROS in the different forms of inter- and intracellular communication, as well as the role of gap junctions, tunneling nanotubes and extracellular vesicles in the propagation of oxidative damage in cardiac diseases, particularly in the context of ischemia/reperfusion injury.

Traditional and Emerging Biomarkers in Asymptomatic Left Ventricular Dysfunction-Promising Non-Coding RNAs and Exosomes as Biomarkers in Early Phases of Cardiac Damage

Heart failure (HF) is one of the major causes of morbidity and mortality worldwide and represents an escalating problem for healthcare systems. The identification of asymptomatic patients with underlying cardiac subclinical disease would create an opportunity for early intervention and prevention of symptomatic HF. Traditional biomarkers are very useful as diagnostic and prognostic tools in the cardiovascular field; however, their application is usually limited to overt cardiac disease. On the other hand, a growing number of studies is investigating the diagnostic and prognostic potential of new biomarkers, such as micro-RNAs (miRNA), long non-coding RNAs, and exosome cargo, because of their involvement in the early phases of cardiac dysfunction. Unfortunately, their use in asymptomatic phases remains a distant goal. The aim of this review is to gather the current knowledge of old and novel biomarkers in the early diagnosis of cardiac dysfunction in asymptomatic individuals.

Multiplexed targeting of miRNA-210 in stem cell-derived extracellular vesicles promotes selective regeneration in ischemic hearts

Extracellular vesicles (EVs) are cell derivatives containing diverse cellular molecules, have various physiological properties and are also present in stem cells used for regenerative therapy. We selected a "multiplexed target" that demonstrates multiple effects on various cardiovascular cells, while functioning as a cargo of EVs. We screened various microRNAs (miRs) and identified miR-210 as a candidate target for survival and angiogenic function. We confirmed the cellular and biological functions of EV-210 (EVs derived from ASC^miR-210) secreted from adipose-derived stem cells (ASCs) transfected with miR-210 (ASC^miR-210). Under hypoxic conditions, we observed that ASC^miR-210 inhibits apoptosis by modulating protein tyrosine phosphatase 1B (PTP1B) and death-associated protein kinase 1 (DAPK1). In hypoxic endothelial cells, EV-210 exerted its angiogenic capacity by inhibiting Ephrin A (EFNA3). Furthermore, EV-210 enhanced cell survival under the control of PTP1B and induced antiapoptotic effects in hypoxic H9c2 cells. In cardiac fibroblasts, the fibrotic ratio was reduced after exposure to EV-210, but EVs derived from ASC^miR-210 did not communicate with fibroblasts. Finally, we observed the functional restoration of the ischemia/reperfusion-injured heart by maintaining the intercommunication of EVs and cardiovascular cells derived from ASC^miR-210. These results suggest that the multiplexed target with ASC^miR-210 is a useful tool for cardiovascular regeneration.

[Significance of exosomes in cardiology: heralds of cardioprotection]

Los exosomas tienen un papel clave en la comunicación intercelular. Debido a sus múltiples interacciones, estas estructuras cumplen con el papel de «mensajeros» de forma dinámica, transportando su contenido a células blanco específicas y generando nuevas señales celulares. En este artículo se describen algunas de las proteínas, lípidos y ácidos nucleicos que son transportados por estas vesículas y que se han relacionado con cardioprotección, con la finalidad de proporcionar información y generar interés sobre la relevancia de los exosomas como posibles blancos diagnósticos y terapéuticos.

A critical approach for successful use of circulating microRNAs as biomarkers in cardiovascular diseases: the case of hypertrophic cardiomyopathy

MicroRNAs (miRNAs) are small noncoding RNA molecules that act as major regulators of gene expression at the post-transcriptional level. As the potential applications of miRNAs in the diagnosis and treatment of human diseases have become more evident, many studies of hypertrophic cardiomyopathy (HCM) have focused on the systemic identification and quantification of miRNAs in biofluids and myocardial tissues. HCM is a hereditary cardiomyopathy caused by mutations in genes encoding proteins of the sarcomere. Despite overall improvements in survival, progression to heart failure, stroke, and sudden cardiac death remain prominent features of living with HCM. Several miRNAs have been shown to be promising biomarkers of HCM; however, there are many challenges to ensuring the validity, consistency, and reproducibility of these biomarkers for clinical use. In particular, miRNA testing may be limited by pre-analytical and analytical caveats, making our interpretation of results challenging. Such factors that may affect miRNA testing include sample type selection, hemolysis, platelet activation, and renal dysfunction. Therefore, researchers should be careful when developing appropriate standards for the design of miRNA profiling studies in order to ensure that all results provided are both accurate and reliable. In this review, we discuss the application of miRNAs as biomarkers for HCM.

Exosome-Derived Mediators as Potential Biomarkers for Cardiovascular Diseases: A Network Approach

Cardiovascular diseases (CVDs) are widely recognized as the leading cause of mortality worldwide. Despite the advances in clinical management over the past decades, the underlying pathological mechanisms remain largely unknown. Exosomes have drawn the attention of researchers for their relevance in intercellular communication under both physiological and pathological conditions. These vesicles are suggested as complementary prospective biomarkers of CVDs; however, the role of exosomes in CVDs is still not fully elucidated. Here, we performed a literature search on exosomal biogenesis, characteristics, and functions, as well as the different available exosomal isolation techniques. Moreover, aiming to give new insights into the interaction between exosomes and CVDs, network analysis on the role of exosome-derived mediators in coronary artery disease (CAD) and heart failure (HF) was also performed to incorporate the different sources of information. The upregulated exosomal miRNAs miR-133a, miR-208a, miR-1, miR-499-5p, and miR-30a were described for the early diagnosis of acute myocardial infarction, while the exosome-derived miR-192, miR-194, miR-146a, and miR-92b-5p were considered as potential biomarkers for HF development. In CAD patients, upregulated exosomal proteins, including fibrinogen beta/gamma chain, inter-alpha-trypsin inhibitor heavy chain, and alpha-1 antichymotrypsin, were assessed as putative protein biomarkers. From downregulated proteins in CAD patients, albumin, clusterin, and vitamin D-binding protein were considered relevant to assess prognosis. The Vesiclepedia database included miR-133a of exosomal origin upregulated in patients with CAD and the exosomal miR-192, miR-194, and miR-146a upregulated in patients with HF. Additionally, Vesiclepedia included 5 upregulated and 13 downregulated exosomal proteins in patients in CAD. The non-included miRNAs and proteins have not yet been identified in exosomes and can be proposed for further research. This report highlights the need for further studies focusing on the identification and validation of miRNAs and proteins of exosomal origin as biomarkers of CAD and HF, which will enable, using exosomal biomarkers, the guiding of diagnosis/prognosis in CVDs.

Cellular signaling cross-talk between different cardiac cell populations: an insight into the role of exosomes in the heart diseases and therapy

Exosomes are a subgroup of extracellular bilayer membrane nanovesicles that are enriched in a variety of bioactive lipids, receptors, transcription factors, surface proteins, DNA, and noncoding RNAs. They have been well recognized to play essential roles in mediating intercellular signaling by delivering bioactive molecules from host cells to regulate the physiological processes of recipient cells. In the context of heart diseases, accumulating studies have indicated that exosome-carried cellular proteins and noncoding RNA derived from different types of cardiac cells, including cardiomyocytes, fibroblasts, endothelial cells, immune cells, adipocytes, and resident stem cells, have pivotal roles in cardiac remodeling under disease conditions such as cardiac hypertrophy, diabetic cardiomyopathy, and myocardial infarction. In addition, exosomal contents derived from stem cells have been shown to be beneficial for regenerative potential of the heart. In this review, we discuss current understanding of the role of exosomes in cardiac communication, with a focus on cardiovascular pathophysiology and perspectives for their potential uses as cardiac therapies.

Influence of microRNAs and exosomes in muscle health and diseases

microRNAs are short, (18-22 nt) non-coding RNAs involved in important cellular processes due to their ability to regulate gene expression at the post-transcriptional level. Exosomes are small (50-200 nm) extracellular vesicles, naturally secreted from a variety of living cells and are believed to mediate cell-cell communication through multiple mechanisms, including uptake in destination cells. Circulating microRNAs and exosome-derived microRNAs can have key roles in regulating muscle cell development and differentiation. Several microRNAs are highly expressed in muscle and their regulation is important for myocyte homeostasis. Changes in muscle associated microRNA expression are associated with muscular diseases including muscular dystrophies, inflammatory myopathies, and congenital myopathies. In this review, we aim to highlight the biology of microRNAs and exosomes as well as their roles in muscle health and diseases. We also discuss the potential crosstalk between skeletal and cardiac muscle through exosomes and their contents.

Duchenne muscular dystrophy (DMD) cardiomyocyte-secreted exosomes promote the pathogenesis of DMD-associated cardiomyopathy

Cardiomyopathy is a leading cause of early mortality in Duchenne muscular dystrophy (DMD). There is a need to gain a better understanding of the molecular pathogenesis for the development effective therapies. Exosomes (exo) are secreted vesicles and exert effects via their RNA, lipid and protein cargo. The role of exosomes in disease pathology is unknown. Exosomes derived from stem cells have demonstrated cardioprotection in the murine DMD heart. However, it is unknown how the disease status of the donor cell type influences exosome function. Here, we sought to determine the phenotypic responses of DMD cardiomyocytes (DMD-iCMs) after long-term exposure to DMD cardiac exosomes (DMD-exo). DMD-iCMs were vulnerable to stress, evidenced by production of reactive oxygen species, the mitochondrial membrane potential and cell death levels. Long-term exposure to non-affected exosomes (N-exo) was protective. By contrast, long-term exposure to DMD-exo was not protective, and the response to stress improved with inhibition of DMD-exo secretion in vitro and in vivo The microRNA (miR) cargo, but not exosome surface peptides, was implicated in the pathological effects of DMD-exo. Exosomal surface profiling revealed N-exo peptides associated with PI3K-Akt signaling. Transcriptomic profiling identified unique changes with exposure to either N- or DMD-exo. Furthermore, DMD-exo miR cargo regulated injurious pathways, including p53 and TGF-beta. The findings reveal changes in exosomal cargo between healthy and diseased states, resulting in adverse outcomes. Here, DMD-exo contained miR changes, which promoted the vulnerability of DMD-iCMs to stress. Identification of these molecular changes in exosome cargo and effectual phenotypes might shed new light on processes underlying DMD cardiomyopathy.This article has an associated First Person interview with the first author of the paper.

Highly purified extracellular vesicles from human cardiomyocytes demonstrate preferential uptake by human endothelial cells

Extracellular vesicles (EVs) represent a promising cell-free alternative for treatment of cardiovascular diseases. Nevertheless, the lack of standardised and reproducible isolation methods capable of recovering pure, intact EVs presents a significant obstacle. Additionally, there is significant interest in investigating the interactions of EVs with different cardiac cell types. Here we established a robust technique for the production and isolation of EVs harvested from an enriched (>97% purity) population of human induced pluripotent stem cell (iPSC)-derived cardiomyocytes (CMs) with size exclusion chromatography. Utilizing an advanced fluorescence labelling strategy, we then investigated the interplay of the CM-EVs with the three major cellular components of the myocardium (fibroblasts, cardiomyocytes and endothelial cells) and identified that cardiac endothelial cells show preferential uptake of these EVs. Overall, our findings provide a great opportunity to overcome the translational hurdles associated with the isolation of intact, non-aggregated human iPSC-CM EVs at high purity. Furthermore, understanding in detail the interaction of the secreted EVs with their surrounding cells in the heart may open promising new avenues in the field of EV engineering for targeted delivery in cardiac regeneration.

Recent advances on the roles of LncRNAs in cardiovascular disease

Cardiovascular diseases are a main cause of mortality whose prevalence continues to increase worldwide. Long non-coding RNAs (lncRNAs) regulate a variety of biological processes by modifying and regulating transcription of coding genes, directly binding to proteins and even coding proteins themselves. LncRNAs play key roles in the occurrence and development of myocardial infarction, heart failure, myocardial hypertrophy, arrhythmias and other pathological processes that significantly affect the prognosis and survival of patients with cardiovascular diseases. We here review the latest research on lncRNAs in cardiovascular diseases as a basis to formulate future research on prevention and treatment of cardiovascular diseases.

Experimental limitations of extracellular vesicle-based therapies for the treatment of myocardial infarction

Extracellular vesicles (EVs) are particles secreted by a vast variety of cells and are often recognised to mimic the properties of their parent cell, as such those derived from developmental sources hold promise for the treatment of various diseases including myocardial infarction (MI). Here we review the experimental approaches taken for assessing the therapeutic efficacy of EVs for MI and find overt shortcomings regarding purity of isolated EVs, quantitation, dosing, EV labelling/uptake, route of administration and use of appropriate controls that renders much of the data uninterpretable. Overall, the EV/MI field has suffered from experimental approaches that are not fully standardised or validated. Fundamental improvements in EV study design are required to improve interpretation of efficacy and to ensure reproducibility and comparability across preclinical MI studies.

Extracellular vesicles in cardiovascular diseases

Due to the continued high incidence and mortality rate worldwide, there is still a need to develop new strategies for the prevention, diagnosis and treatment of cardiovascular diseases (CVDs). Proper cardiovascular function depends on the coordinated interplay and communication between cardiomyocytes and noncardiomyocytes. Extracellular vesicles (EVs) are enclosed in a lipid bilayer and represent a significant mechanism for intracellular communication. By containing and transporting various bioactive molecules, such as micro-ribonucleic acids (miRs) and proteins, to target cells, EVs impart favourable, neutral or detrimental effects on recipient cells, such as modulating gene expression, influencing cell phenotype, affecting molecular pathways and mediating biological behaviours. EVs can be released by cardiovascular system-related cells, such as cardiomyocytes, endotheliocytes, fibroblasts, platelets, smooth muscle cells, leucocytes, monocytes and macrophages. EVs containing miRs and proteins regulate a multitude of diverse functions in target cells, maintaining cardiovascular balance and health or inducing pathological changes in CVDs. On the one hand, miRs and proteins transferred by EVs play biological roles in maintaining normal cardiac structure and function under physiological conditions. On the other hand, EVs change the composition of their miR and protein cargoes under pathological conditions, which gives rise to the development of CVDs. Therefore, EVs hold tremendous potential to prevent, diagnose and treat CVDs. The current article reviews the specific functions of EVs in different CVDs.

Small but significant: Insights and new perspectives of exosomes in cardiovascular disease

Cardiovascular diseases (CVDs) are a major health problem worldwide, and health professionals are still actively seeking new and effective approaches for CVDs treatment. Presently, extracellular vesicles, particularly exosomes, have gained its popularity for CVDs treatment because of their function as messengers for inter- and extra-cellular communications to promote cellular functions in cardiovascular system. However, as a newly developed field, researchers are still trying to fully understand the role of exosomes, and their mechanism in mediating cardiac repair process. Therefore, a comprehensive review of this topic can be timely and favourable. In this review, we summarized the basic biogenesis and characterization of exosomes and then further extended the focus on the circulating exosomes in cellular communication and stem cell-derived exosomes in cardiac disease treatment. In addition, we covered interactions between the heart and other organs through exosomes, leading to the diagnostic characteristics of exosomes in CVDs. Future perspectives and limitations of exosomes in CVDs were also discussed with a special focus on exploring the potential delivery routes, targeting the injured tissue and engineering novel exosomes, as well as its potential as one novel target in the metabolism-related puzzle.

Concise Review: Harnessing iPSC-derived Cells for Ischemic Heart Disease Treatment

Ischemic heart disease (IHD) is one of the most common cardiovascular diseases and is the leading cause of death worldwide. Stem cell therapy is a promising strategy to promote cardiac regeneration and myocardial function recovery. Recently, the generation of human induced pluripotent cells (hiPSCs) and their differentiation into cardiomyocytes and vascular cells offer an unprecedented opportunity for the IHD treatment. This review briefly summarizes hiPSCs and their differentiation, and presents the recent advances in hiPSC injection, engineered cardiac patch fabrication, and the application of hiPSC derived extracellular vesicle. Current challenges and further perspectives are also discussed to understand current risks and concerns, identify potential solutions, and direct future clinical trials and applications.

Particle-based artificial three-dimensional stem cell spheroids for revascularization of ischemic diseases

Development of new approaches to biomimetically reconstruct vasculature networks remains challenging in regenerative medicine. We introduce a particle-based artificial stem cell spheroid (ASSP) technology that recapitulates paracrine functions of three-dimensional (3D) SSPs for vasculature regeneration. Specifically, we used a facile method to induce the aggregation of stem cells into 3D spheroids, which benefited from hypoxia microenvironment-driven and enhanced secretion of proangiogenic bioactive factors. Furthermore, we artificially reconstructed 3D spheroids (i.e., ASSP) by integration of SSP-secreted factors into micro-/nanoparticles with cell membrane-derived surface coatings. The easily controllable sizes of the ASSP particles provided superior revascularization effects on the ischemic tissues in hindlimb ischemia models through local administration of ASSP microparticles and in myocardial infarction models via the systemic delivery of ASSP nanoparticles. The strategy offers a promising therapeutic option for ischemic tissue regeneration and addresses issues faced by the bottlenecked development in the delivery of stem cell therapies.

Exosomes: Cell-Free Therapy for Cardiovascular Diseases

Cardiovascular diseases (CVDs) are an important cause of death and disease worldwide. Because injured cardiac tissue cannot be repaired itself, it is urgent to develop other alternate therapies. Stem cells can be differentiated into cardiomyocytes, endothelial cells, and vascular smooth muscle cells for the treatment of CVDs. Therefore, cell therapy has recently been considered a viable treatment option that can significantly improve cardiac function. Nonetheless, implanted stem cells rarely survive in the recipient heart, suggesting that the benefits of stem cell therapy may involve other mechanisms. Exosomes derived from stem cells have a myocardial protection function after myocardial injury, and may be a promising and effective therapy for CVDs. Here, we discuss the application and mechanism of exosomes derived from stem cells in the diagnosis and treatment of CVDs and provide evidence for the application of exosomes in CVDs. Graphical Abstract.

Small Extracellular Microvesicles Mediated Pathological Communications Between Dysfunctional Adipocytes and Cardiomyocytes as a Novel Mechanism Exacerbating Ischemia/Reperfusion Injury in Diabetic Mice

BACKGROUND

Diabetes mellitus exacerbates myocardial ischemia/reperfusion (MI/R) injury by incompletely understood mechanisms. Adipocyte dysfunction contributes to remote organ injury. However, the molecular mechanisms linking dysfunctional adipocytes to increased MI/R injury remain unidentified. The current study attempted to clarify whether and how small extracellular vesicles (sEV) may mediate pathological communication between diabetic adipocytes and cardiomyocytes, exacerbating MI/R injury.

METHODS

Adult male mice were fed a normal or a high-fat diet for 12 weeks. sEV (from diabetic serum, diabetic adipocytes, or high glucose/high lipid-challenged nondiabetic adipocytes) were injected intramyocardially distal of coronary ligation. Animals were subjected to MI/R 48 hours after injection.

RESULTS

Intramyocardial injection of diabetic serum sEV in the nondiabetic heart significantly exacerbated MI/R injury, as evidenced by poorer cardiac function recovery, larger infarct size, and greater cardiomyocyte apoptosis. Similarly, intramyocardial or systemic administration of diabetic adipocyte sEV or high glucose/high lipid-challenged nondiabetic adipocyte sEV significantly exacerbated MI/R injury. Diabetic epididymal fat transplantation significantly increased MI/R injury in nondiabetic mice, whereas administration of a sEV biogenesis inhibitor significantly mitigated MI/R injury in diabetic mice. A mechanistic investigation identified that miR-130b-3p is a common molecule significantly increased in diabetic serum sEV, diabetic adipocyte sEV, and high glucose/high lipid-challenged nondiabetic adipocyte sEV. Mature (but not primary) miR-130b-3p was significantly increased in the diabetic and nondiabetic heart subjected to diabetic sEV injection. Whereas intramyocardial injection of a miR-130b-3p mimic significantly exacerbated MI/R injury in nondiabetic mice, miR-130b-3p inhibitors significantly attenuated MI/R injury in diabetic mice. Molecular studies identified AMPKα1/α2, Birc6, and Ucp3 as direct downstream targets of miR-130b-3p. Overexpression of these molecules (particularly AMPKα2) reversed miR-130b-3p induced proapoptotic/cardiac harmful effect. Finally, miR-130b-3p levels were significantly increased in plasma sEV from patients with type 2 diabetes mellitus. Incubation of cardiomyocytes with diabetic patient sEV significantly exacerbated ischemic injury, an effect blocked by miR-130b-3p inhibitor.

CONCLUSIONS

We demonstrate for the first time that miR-130b-3p enrichment in dysfunctional adipocyte-derived sEV, and its suppression of multiple antiapoptotic/cardioprotective molecules in cardiomyocytes, is a novel mechanism exacerbating MI/R injury in the diabetic heart. Targeting miR-130b-3p mediated pathological communication between dysfunctional adipocytes and cardiomyocytes may be a novel strategy attenuating diabetic exacerbation of MI/R injury.

The Role of Bone-Derived Exosomes in Regulating Skeletal Metabolism and Extraosseous Diseases

Bone-derived exosomes are naturally existing nano-sized extracellular vesicles secreted by various cells, such as bone marrow stromal cells, osteoclasts, osteoblasts, and osteocytes, containing multifarious proteins, lipids, and nucleic acids. Accumulating evidence indicates that bone-derived exosomes are involved in the regulation of skeletal metabolism and extraosseous diseases through modulating intercellular communication and the transfer of materials. Following the development of research, we found that exosomes can be considered as a potential candidate as a drug delivery carrier thanks to its ability to transport molecules into targeted cells with high stability, safety, and efficiency. This review aims to discuss the emerging role of bone-derived exosomes in skeletal metabolism and extraosseous diseases as well as their potential role as candidate biomarkers or for developing new therapeutic strategies.

Extracellular vesicles isolated from patients undergoing remote ischemic preconditioning decrease hypoxia-evoked apoptosis of cardiomyoblasts after isoflurane but not propofol exposure

Remote ischemic preconditioning (RIPC) can evoke cardioprotection following ischemia/reperfusion and this may depend on the anesthetic used. We tested whether 1) extracellular vesicles (EVs) isolated from humans undergoing RIPC protect cardiomyoblasts against hypoxia-induced apoptosis and 2) this effect is altered by cardiomyoblast exposure to isoflurane or propofol. EVs were isolated before and 60 min after RIPC or Sham from ten patients undergoing coronary artery bypass graft surgery with isoflurane anesthesia and quantified by Nanoparticle Tracking Analysis. Following EV-treatment for 6 hours under exposure of isoflurane or propofol, rat H9c2 cardiomyoblasts were cultured for 18 hours in normoxic or hypoxic atmospheres. Apoptosis was detected by flow cytometry. Serum nanoparticle concentrations in patients had increased sixty minutes after RIPC compared to Sham (2.5x10¹¹±4.9x10¹⁰ nanoparticles/ml; Sham: 1.2x10¹¹±2.0x10¹⁰; p = 0.04). Hypoxia increased apoptosis of H9c2 cells (hypoxia: 8.4%±0.6; normoxia: 2.5%±0.1; p<0.0001). RIPC-EVs decreased H9c2 cell apoptosis compared to control (apoptotic ratio: 0.83; p = 0.0429) while Sham-EVs showed no protection (apoptotic ratio: 0.97). Prior isoflurane exposure in vitro even increased protection (RIPC-EVs/control, apoptotic ratio: 0.79; p = 0.0035; Sham-EVs/control, apoptotic ratio:1.04) while propofol (50μM) abrogated protection by RIPC-EVs (RIPC-EVs/control, Apoptotic ratio: 1.01; Sham-EVs/control, apoptotic ratio: 0.94; p = 0.602). Thus, EVs isolated from patients undergoing RIPC under isoflurane anesthesia protect H9c2 cardiomyoblasts against hypoxia-evoked apoptosis and this effect is abrogated by propofol. This supports a role of human RIPC-generated EVs in cardioprotection and underlines propofol as a possible confounder in RIPC-signaling mediated by EVs.

Human induced pluripotent stem cells ameliorate hyperoxia-induced lung injury in a mouse model

Hyperoxia-induced lung injury occurs in neonates on oxygen support due to premature birth, often leading to the development of bronchopulmonary dysplasia. Current treatment options have limited effect. The aim of this study was to determine if human induced pluripotent stem cells (iPSCs) and those differentiated to an alveolar-like phenotype (diPSCs) could repair hyperoxia-induced lung damage in a mouse model. Neonatal C57BL6/J mice were separated into two groups and exposed to 75% oxygen over 6 or 14 days. Cell treatments were instilled intra-orally following removal. Controls included hyperoxia, normoxia, and a vehicle. 7 and 14 days post treatment, lungs were extracted and histomorphometric analysis performed. Gene expression of markers mediating inflammation (Tgfβ1, Nfkb1, and Il-6) were investigated. In addition, exosomes from each cell type were isolated and administered as a cell free alternative. There was a significant difference between the mean linear intercept (MLI) in hyperoxic vs. normoxic lungs prior to treatment. No difference existed between the MLI in iPSC-treated lungs vs. normoxic lungs after 6 and 14 days of hyperoxia. For mice exposed to 6 days of hyperoxia, gene expression in iPSC-treated lungs returned to normal 14 days later. At the same time points, diPSCs were not as effective. Exosomes were also not as effective in reversing hyperoxic lung damage as their cellular counterparts. This study highlights the potential benefit of using iPSCs to repair damaged lung tissue through possible modulation of the inflammatory response, leading to novel therapies for acute hyperoxia-induced lung injury and the prevention of bronchopulmonary dysplasia.