Extracellular vesicles for treatment of solid organ ischemia-reperfusion injury

Normothermic Ex Vivo Heart Perfusion With Exosomes From Human Umbilical Cord Mesenchymal Stem Cells Improves Graft Function in Donation After Circulatory Death Hearts

BACKGROUND

This study aimed to investigate the cardioprotective effect of exosomes derived from human umbilical cord mesenchymal stem cells on donation after circulatory death (DCD) hearts preserved with normothermic ex vivo heart perfusion (EVHP) in a rat heart transplantation model.

METHODS

Thirty-two male Lewis rats were divided into 2 groups: the control group and the exosome group. The donor-heart rats were subjected to the DCD procedure by suffering a 15-min warm ischemia injury, subsequently preserved with EVHP for 90 min, and then transplanted into recipients via abdominal heterotopic heart transplantation. Vehicle or exosome was added into the perfusate of normothermic EVHP in the control or exosome group. We evaluated left ventricular graft function, myocardial inflammation, and myocardial apoptosis of the donor heart 1.5 h after heart transplantation. Furthermore, we investigate the alternation of myocardial gene expression in the donor hearts between both groups by transcriptome sequencing.

RESULTS

The treatment with exosome significantly enhanced cardiac function through increasing left ventricular developed pressure, dp/dt max , and dp/dt min of DCD hearts at 90 min after heart transplantation compared with the control group. The myocardial cells in the exosome group exhibited an orderly arrangement without obvious edema. Furthermore, exosome added into perfusate in the exosome group significantly attenuated the level of inflammatory response and apoptosis. Transcriptome sequencing and RT-qPCR showed the phosphoinositide 3-kinase/protein kinase B pathway was activated after exosome treatment.

CONCLUSIONS

Normothermic EVHP combined with exosome can be a promising and novel DCD heart preservation strategy, alleviating myocardial ischemia-reperfusion injury in the DCD heart.

Drug delivery strategies for local immunomodulation in transplantation: Bridging the translational gap

Drug delivery strategies for local immunomodulation hold tremendous promise compared to current clinical gold-standard systemic immunosuppression as they could improve the benefit to risk ratio of life-saving or life-enhancing transplants. Such strategies have facilitated prolonged graft survival in animal models at lower drug doses while minimizing off-target effects. Despite the promising outcomes in preclinical animal studies, progression of these strategies to clinical trials has faced challenges. A comprehensive understanding of the translational barriers is a critical first step towards clinical validation of effective immunomodulatory drug delivery protocols proven for safety and tolerability in pre-clinical animal models. This review overviews the current state-of-the-art in local immunomodulatory strategies for transplantation and outlines the key challenges hindering their clinical translation.

Colchicine prevents perioperative myocardial injury in cardiac surgery by inhibiting the formation of neutrophil extracellular traps: evidence from rat models

OBJECTIVES

Colchicine, an anti-inflammatory agent, has been reported to improve myocardial infarction prognosis by inhibiting neutrophil extracellular traps (NETs) release. However, its role in cardiac surgery and the mechanisms behind NETs suppression remain unclear. This study aimed to explore colchicine's cardioprotective effects against perioperative myocardial injury in cardiac surgery, focusing on NETs inhibition as a novel therapeutic strategy.

METHODS

Male Sprague-Dawley rats were pre-treated with colchicine (0.1 mg/kg/day) or CI-amidine (10 mg/kg/day) for 7 days before undergoing cardiopulmonary bypass and myocardial ischaemia/reperfusion injury. The model was created by subjecting the rats to cardiopulmonary bypass and myocardial ischaemia/reperfusion injury. Under 4.0% sevoflurane anaesthesia, cardiopulmonary bypass was initiated by cannulating the tail artery and right atrium, and perfusion was maintained for 4 h. Immunofluorescence detected NETs, and haematoxylin and eosin staining assessed inflammatory cell.

RESULTS

We found colchicine treatment significantly reduced perioperative myocardial injury in rats. Furthermore, we observed a notable elevation of NETs in the myocardial tissue of animal models. Moreover, suppressing peptidylarginine deiminase 4 was found to markedly diminish perioperative myocardial injury in rats. Additionally, colchicine can mitigate the release of NETs by inhibiting peptidylarginine deiminase 4.

CONCLUSIONS

NETs were significantly elevated during the perioperative period of cardiac surgery. Colchicine significantly mitigated myocardial injury in cardiac surgery by inhibiting NETs formation, with peptidylarginine deiminase 4 inhibition being one of its mechanisms.

Transcriptomic Signatures in Lung Allografts and Their Therapeutic Implications

Ex vivo lung perfusion (EVLP) is a well-established method of lung preservation in clinical transplantation. Transcriptomic analyses of cells and tissues uncover gene expression patterns which reveal granular molecular pathways and cellular programs under various conditions. Coupling EVLP and transcriptomics may provide insights into lung allograft physiology at a molecular level with the potential to develop targeted therapies to enhance or repair the donor lung. This review examines the current landscape of transcriptional analysis of lung allografts in the context of state-of-the-art therapeutics that have been developed to optimize lung allograft function.

Immunogenicity of Extracellular Vesicles

Extracellular vesicles (EVs) are promising next-generation therapeutics and drug delivery systems due to demonstrated safety and efficacy in preclinical models and early-stage clinical trials. There is an urgent need to address the immunogenicity of EVs (beyond the apparent lack of immunotoxicity) to advance clinical development. To date, few studies have assessed unintended immunological recognition of EVs. An in-depth understanding of EV-induced immunogenicity and clearance is necessary to develop effective therapeutic strategies, including approaches to mitigate immunological recognition when undesired. This article summarizes various factors involved in the potential immunogenicity of EVs and strategies to reduce immunological recognition for improved therapeutic benefit.

Hypoxia-preconditioned WJ-MSC spheroid-derived exosomes delivering miR-210 for renal cell restoration in hypoxia-reoxygenation injury

BACKGROUND

Recent advancements in mesenchymal stem cell (MSC) technology have paved the way for innovative treatment options for various diseases. These stem cells play a crucial role in tissue regeneration and repair, releasing local anti-inflammatory and healing signals. However, challenges such as homing issues and tumorigenicity have led to exploring MSC-exosomes as a promising alternative. MSC-exosomes have shown therapeutic potential in conditions like renal ischemia-reperfusion injury, but low production yields hinder their clinical use.

METHODS

To address this limitation, we examined hypoxic preconditioning of Wharton jelly-derived MSCs (WJ-MSCs) 3D-cultured in spheroids on isolated exosome yields and miR-21 expression. We then evaluated their capacity to load miR-210 into HEK-293 cells and mitigate ROS production, consequently enhancing their survival and migration under hypoxia-reoxygenation conditions.

RESULTS

MiR-210 overexpression was significantly induced by optimized culture and preconditioning conditions, which also improved the production yield of exosomes from grown MSCs. The exosomes enriched with miR-210 demonstrated a protective effect by improving survival, reducing apoptosis and ROS accumulation in damaged renal cells, and ultimately promoting cell migration.

CONCLUSION

The present study underscores the possibility of employing advanced techniques to maximize the therapeutic attributes of exosomes produced from WJ-MSC spheroid for improved recovery outcomes in ischemia-reperfusion injuries.

Chemically-Induced Lipoprotein Breakdown for Improved Extracellular Vesicle Purification

Extracellular vesicles (EVs) are nanosized biomolecular packages involved in intercellular communication. EVs are released by all cells, making them broadly applicable as therapeutic, diagnostic, and mechanistic components in (patho)physiology. Sample purity is critical for correctly attributing observed effects to EVs and for maximizing therapeutic and diagnostic performance. Lipoprotein contaminants represent a major challenge for sample purity. Lipoproteins are approximately six orders of magnitude more abundant in the blood circulation and overlap in size, shape, and density with EVs. This study represents the first example of an EV purification method based on the chemically-induced breakdown of lipoproteins. Specifically, a styrene-maleic acid (SMA) copolymer is used to selectively breakdown lipoproteins, enabling subsequent size-based separation of the breakdown products from plasma EVs. The use of the polymer followed by tangential flow filtration or size-exclusion chromatography results in improved EV yield, preservation of EV morphology, increased EV markers, and reduced contaminant markers. SMA-based EV purification enables improved fluorescent labeling, reduces interactions with macrophages, and enhances accuracy, sensitivity, and specificity to detect EV biomarkers, indicating benefits for various downstream applications. In conclusion, SMA is a simple and effective method to improve the purity and yield of plasma-derived EVs, which favorably impacts downstream applications.

CD44-targeted melanin-based nanoplatform for alleviation of ischemia/reperfusion-induced acute kidney injury

Ischemia/reperfusion (I/R)-induced acute kidney injury (AKI) is a serious kidney disease with high morbidity and mortality. However, there is no effective clinical treatment strategy. Herein, we developed a CD44 targeting nanoplatform based on HA-assembled melanin NPs covalently coupled with dexamethasone for I/R-induced AKI therapy by alleviating oxidative/inflammatory- induced damage. The constructed HA-MNP-DXM NPs had good dispersion, stability, and broad-spectrum scavenging capabilities against multiple reactive free radicals. Moreover, the NPs could be efficiently internalized and exhibited antioxidative, anti-inflammatory, and antiapoptotic effects in CoCl2-stimulated renal tubular epithelial NRK-52E cells. Furthermore, the I/R-induced AKI murine model was established to evaluate the in vivo performance of NPs. The results suggested the NPs could specifically target impaired kidneys upon intravenous administration according to NIR-II fluorescence imaging and showed high biosafety. Importantly, the NPs could improve renal function, alleviate oxidative stress and inflammatory reactions, inhibit apoptosis of tubular cells, and restore mitochondrial structure and function, exhibiting excellent therapeutic effects. Further therapeutic mechanism indicated the NPs maintained the cellular/mitochondrial redox balance by modulating the Nrf2 and HO-1 expression. Therefore, the NPs can be a promising therapeutic candidate for the treatment of I/R-induced AKI.

Histone deacetylase 6 deficiency protects the liver against ischemia/reperfusion injury by activating PI3K/AKT/mTOR signaling

Liver transplantation (LT) is the only effective method to treat end-stage liver disease. Hepatic ischemia-reperfusion injury (IRI) continues to limit the prognosis of patients receiving LT. Histone deacetylase 6 (HDAC6) is a unique HDAC member involved in inflammation and apoptosis. However, its role and mechanism in hepatic IRI have not yet been reported. We examined HDAC6 levels in liver tissue from LT patients, mice challenged with liver IRI, and hepatocytes subjected to hypoxia/reoxygenation (H/R). In addition, HDAC6 global-knockout (HDAC6-KO) mice, adeno-associated virus-mediated liver-specific HDAC6 overexpressing (HDAC6-LTG) mice, and their corresponding controls were used to construct hepatic IRI models. Hepatic histology, inflammatory responses, and apoptosis were detected to assess liver injury. The molecular mechanisms of HDAC6 in hepatic IRI were explored in vivo and in vitro. Moreover, the HDAC6-selective inhibitor tubastatin A was used to detect the therapeutic effect of HDAC6 on liver IRI. Together, our results showed that HDAC6 expression was significantly upregulated in liver tissue from LT patients, mice subjected to hepatic I/R surgery, and hepatocytes challenged by hypoxia/reoxygenation (H/R) treatment. Compared with control mice, HDAC6 deficiency mitigated liver IRI by inhibiting inflammatory responses and apoptosis, whereas HDAC6-LTG mice displayed the opposite phenotype. Further molecular experiments show that HDAC6 bound to and deacetylated AKT and HDAC6 deficiency improved liver IRI by activating PI3K/AKT/mTOR signaling. In conclusion, HDAC6 is a key mediator of hepatic IRI that functions to promote inflammation and apoptosis via PI3K/AKT/mTOR signaling. Targeting hepatic HDAC6 inhibition may be a promising approach to attenuate liver IRI.

Adelmidrol ameliorates liver ischemia-reperfusion injury through activating Nrf2 signaling pathway

Liver ischemia/reperfusion (I/R) injury commonly occurs after various liver surgeries. Adelmidrol, an N- palmitoylethanolamide analog, has anti-inflammatory, anti-oxidant, and anti-injury properties. To investigate whether adelmidrol could reduce liver I/R injury, we established a mouse of liver I/R injury and an AML12 cell hypoxia-reoxygenation model to perform experiments using multiple indicators. Serum ALT and AST levels, and H&E staining were used to measure liver damage; MDA content, superoxide dismutase and glutathione activities, and dihydroethidium staining were used to measure oxidative stress; mRNA expression levels of tumor necrosis factor-α, interleukin (IL)-1β, IL-6, MCP-1, and Ly6G staining were used to measure inflammatory response; and protein expression of Bax, Bcl-2, C-caspase3, and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling staining were used to measure apoptosis. The experimental results showed that adelmidrol reduced liver I/R injury. In addition, adelmidrol pretreatment elevated AML12 cell activity and reduced I/R-and H/R-induced apoptosis, inflammatory injury, and oxidative stress. ML385, an inhibitor of nuclear factor erythroid2-related factor 2 (Nrf2), reverses liver I/R injury attenuated by adelmidrol. These results suggest that adelmidrol ameliorates liver I/R injury by activating the Nrf2 signaling pathway.

High-throughput analysis of glycan sorting into extracellular vesicles

Extracellular vesicles (EVs) are cell-released vesicles that mediate intercellular communication by transferring bioactive cargo. Protein and RNA sorting into EVs has been extensively assessed, while selective enrichment of glycans in EVs remains less explored. In this study, a mass spectrometry-based approach, glycan node analysis (GNA), was applied to broadly assess the sorting of glycan features into EVs. Two metastatic variants (lung and bone) generated in mouse modes from the MDA-MB-231 human breast cancer cell line were assessed, as these EVs are known to contain distinct organotropic biomolecules. EVs were isolated from conditioned cell culture medium by tangential flow filtration and authenticated by standard techniques. GNA analysis revealed selective enrichment of several glycan features in EVs compared to the originating cells, particularly those associated with binding to the extracellular matrix, which was also observed in EVs from the parental MDA-MB-231 cell line (human pleural metastases). The bone-tropic variant displayed enrichment of distinct EV glycan features compared to the lung-tropic one. Additionally, the metastatic variants generated in mouse models displayed reduced EV glycan sorting compared to the parental metastatic cell line. This study represents the first comprehensive assessment of differences in glycan features between EVs and originating cells and provides evidence that the diversity of EV glycan sorting is reduced upon generation of variant cell lines in mouse models. Future research is likely to uncover novel mechanisms of EV glycan sorting, shed light on glycan features for EV authentication or biomarker purposes, and assess functional roles of the EV glycocode in (patho)physiology.

Extracellular Vesicle and Lipoprotein Interactions

Extracellular vesicles and lipoproteins are lipid-based biological nanoparticles that play important roles in (patho)physiology. Recent evidence suggests that extracellular vesicles and lipoproteins can interact to form functional complexes. Such complexes have been observed in biofluids from healthy human donors and in various in vitro disease models such as breast cancer and hepatitis C infection. Lipoprotein components can also form part of the biomolecular corona that surrounds extracellular vesicles and contributes to biological identity. Potential mechanisms and the functional relevance of extracellular vesicle-lipoprotein complexes remain poorly understood. This Review addresses the current knowledge of the extracellular vesicle-lipoprotein interface while drawing on pre-existing knowledge of liposome interactions with biological nanoparticles. There is an urgent need for further research on the lipoprotein-extracellular vesicle interface, which could return important mechanistic, therapeutic, and diagnostic findings.

Extracellular vesicles in degenerative retinal diseases: A new therapeutic paradigm

Nanoscale extracellular vesicles (EVs), consisting of exomers, exosomes and microvesicles/ectosomes, have been extensively investigated in the last 20 years, although their biological role is still something of a mystery. EVs are involved in the transfer of lipids, nucleic acids and proteins from donor to recipient cells or distant organs as well as regulating cell-cell communication and signaling. Thus, EVs are important in intercellular communication and this is not limited to sister cells, but may also mediate the crosstalk between different cell types even over long distances. EVs play crucial functions in both cellular homeostasis and the pathogenesis of diseases, and since their contents reflect the status of the donor cell, they represent an additional valuable source of information for characterizing complex biological processes. Recent advances in isolation and analytical methods have led to substantial improvements in both characterizing and engineering EVs, leading to their use either as novel biomarkers for disease diagnosis/prognosis or even as novel therapies. Due to their capacity to carry biomolecules, various EV-based therapeutic applications have been devised for several pathological conditions, including eye diseases. In the eye, EVs have been detected in the retina, aqueous humor, vitreous body and also in tears. Experiences with other forms of intraocular drug applications have opened new ways to use EVs in the treatment of retinal diseases. We here provide a comprehensive summary of the main in vitro, in vivo, and ex vivo literature-based studies on EVs' role in ocular physiological and pathological conditions. We have focused on age-related macular degeneration, diabetic retinopathy, glaucoma, which are common eye diseases leading to permanent blindness, if not treated properly. In addition, the putative use of EVs in retinitis pigmentosa and other retinopathies is discussed. Finally, we have reviewed the potential of EVs as therapeutic tools and/or biomarkers in the above-mentioned retinal disorders. Evidence emerging from experimental disease models and human material strongly suggests future diagnostic and/or therapeutic exploitation of these biological agents in various ocular disorders with a good possibility to improve the patient's quality of life.

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.

Clinical Translation of Extracellular Vesicles

Extracellular vesicles (EVs) occur in a variety of bodily fluids and have gained recent attraction as natural materials due to their bioactive surfaces, internal cargo, and role in intercellular communication. EVs contain various biomolecules, including surface and cytoplasmic proteins; and nucleic acids that are often representative of the originating cells. EVs can transfer content to other cells, a process that is thought to be important for several biological processes, including immune responses, oncogenesis, and angiogenesis. An increased understanding of the underlying mechanisms of EV biogenesis, composition, and function has led to an exponential increase in preclinical and clinical assessment of EVs for biomedical applications, such as diagnostics and drug delivery. Bacterium-derived EV vaccines have been in clinical use for decades and a few EV-based diagnostic assays regulated under Clinical Laboratory Improvement Amendments have been approved for use in single laboratories. Though, EV-based products are yet to receive widespread clinical approval from national regulatory agencies such as the United States Food and Drug Administration (USFDA) and European Medicine Agency (EMA), many are in late-stage clinical trials. This perspective sheds light on the unique characteristics of EVs, highlighting current clinical trends, emerging applications, challenges and future perspectives of EVs in clinical use.

Insight into extracellular vesicles in vascular diseases: intercellular communication role and clinical application potential

BACKGROUND

Cells have been increasingly known to release extracellular vesicles (EVs) to the extracellular environment under physiological and pathological conditions. A plethora of studies have revealed that EVs contain cell-derived biomolecules and are found in circulation, thereby implicating them in molecular trafficking between cells. Furthermore, EVs have an effect on physiological function and disease development and serve as disease biomarkers.

MAIN BODY

Given the close association  between EV circulation and vascular disease, this review aims to provide a brief introduction to EVs, with a specific focus on the EV cargoes participating in pathological mechanisms, diagnosis, engineering, and clinical potential, to highlight the emerging evidence suggesting promising targets in vascular diseases. Despite the expansion of research in this field, some noticeable limitations remain for clinical translational research.

CONCLUSION

This review makes a novel contribution to a summary of recent advances and a perspective on the future of EVs in vascular diseases. Video Abstract.

Lycium barbarum polysaccharide inhibits ischemia-induced autophagy by promoting the biogenesis of neural stem cells-derived extracellular vesicles to enhance the delivery of miR-133a-3p

BACKGROUND

Neural stem cell-derived extracellular vesicles (NSC-EVs) mediated endogenous neurogenesis determines a crucial impact on spontaneous recovery after stroke. Here, we checked the influence of Lycium barbarum polysaccharide (LBP) on the biogenesis of NSC-EVs and then focused on studying mechanisms of LBP in ameliorating ischemic stroke outcome.

METHODS

LBP was prepared to precondition NSCs and isolate EVs. MCAO models and primary NSCs were administrated to evaluate the therapeutic effect. RT-PCR, western blot, flow cytometry, and immunofluorescence techniques were performed to explore the mechanism.

RESULTS

LBP pretreatment increased the production of NSC-EVs and improved the neuroprotective and recovery effects of NSC-EV in ischemic stroke mice. LBP-pretreated NSC-EV in a dose-dependent manner substantially reduced neuronal death compared with NSC-EV. Screening of the signaling cascade involved in the interaction between NSC-EV and neurons revealed that AMPK/mTOR signaling pathway inhibited autophagic activity in neurons receiving either treatment paradigm. NSC-EVs but not EVs collected from NSCs pretreated with the anti-miR-133a-3p oligonucleotide reduced cell death, whereas the anti-oligonucleotide promoted autophagy activity and cell death by modulating AMPK/mTOR signaling in OGD-induced primary neurons.

CONCLUSION

LBP activated AMPK/mTOR signaling pathway by increasing the enrichment and transfer of miR-133a-3p in NSC-EVs to inhibit stroke-induced autophagy activity.

Role of extracellular vesicles in pathogenesis and therapy of renal ischemia-reperfusion injury

Renal ischemia-reperfusion injury (RIRI) is a complex disorder characterized by both intrinsic damage to renal tubular epithelial cells and extrinsic inflammation mediated by cytokines and immune cells. Unfortunately, there is no cure for this devastating condition. Extracellular vesicles (EVs) are nanosized membrane-bound vesicles secreted by various cell types that can transfer bioactive molecules to target cells and modulate their function. EVs have emerged as promising candidates for cell-free therapy of RIRI, owing to their ability to cross biological barriers and deliver protective signals to injured renal cells. In this review, we provide an overview of EVs, focusing on their functional role in RIRI and the signaling messengers responsible for EV-mediated crosstalk between various cell types in renal tissue. We also discuss the renoprotective role of EVs and their use as therapeutic agents for RIRI, highlighting the advantages and challenges encountered in the therapeutic application of EVs in renal disease.

Extracellular vesicles as personalized medicine

Extracellular vesicles (EVs) are released from all cells in the body, forming an important intercellular communication network that contributes to health and disease. The contents of EVs are cell source-specific, inducing distinct signaling responses in recipient cells. The specificity of EVs and their accumulation in fluid spaces that are accessible for liquid biopsies make them highly attractive as potential biomarkers and therapies for disease. The duality of EVs as favorable (therapeutic) or unfavorable (pathological) messengers is context dependent and remains to be fully determined in homeostasis and various disease states. This review describes the use of EVs as biomarkers, drug delivery vehicles, and regenerative therapeutics, highlighting examples involving viral infections, cancer, and neurological diseases. There is growing interest to provide personalized therapy based on individual patient and disease characteristics. Increasing evidence suggests that EV biomarkers and therapeutic approaches are ideal for personalized medicine due to the diversity and multifunctionality of EVs.

Glycan Node Analysis Detects Varying Glycosaminoglycan Levels in Melanoma-Derived Extracellular Vesicles

Extracellular vesicles (EVs) play important roles in (patho)physiological processes by mediating cell communication. Although EVs contain glycans and glycosaminoglycans (GAGs), these biomolecules have been overlooked due to technical challenges in comprehensive glycome analysis coupled with EV isolation. Conventional mass spectrometry (MS)-based methods are restricted to the assessment of N-linked glycans. Therefore, methods to comprehensively analyze all glyco-polymer classes on EVs are urgently needed. In this study, tangential flow filtration-based EV isolation was coupled with glycan node analysis (GNA) as an innovative and robust approach to characterize most major glyco-polymer features of EVs. GNA is a molecularly bottom-up gas chromatography-MS technique that provides unique information that is unobtainable with conventional methods. The results indicate that GNA can identify EV-associated glyco-polymers that would remain undetected with conventional MS methods. Specifically, predictions based on GNA identified a GAG (hyaluronan) with varying abundance on EVs from two different melanoma cell lines. Enzyme-linked immunosorbent assays and enzymatic stripping protocols confirmed the differential abundance of EV-associated hyaluronan. These results lay the framework to explore GNA as a tool to assess major glycan classes on EVs, unveiling the EV glycocode and its biological functions.

Injectable Drug Delivery Systems for Osteoarthritis and Rheumatoid Arthritis

Joint diseases are one of the most common causes of morbidity and disability worldwide. The main diseases that affect joint cartilage are osteoarthritis and rheumatoid arthritis, which require chronic treatment focused on symptomatic relief. Conventional drugs administered through systemic or intra-articular routes have low accumulation and/or retention in articular cartilage, causing dose-limiting toxicities and reduced efficacy. Therefore, there is an urgent need to develop improved strategies for drug delivery, in particular, the use of micro- and nanotechnology-based methods. Encapsulation of therapeutic agents in delivery systems reduces drug efflux from the joint and protects against rapid cellular and enzymatic clearance following intra-articular injection. Consequently, the use of drug delivery systems decreases side effects and increases therapeutic efficacy due to enhanced drug retention in the intra-articular space. Additionally, the frequency of intra-articular administration is reduced, as delivery systems enable sustained drug release. This review summarizes various advanced drug delivery systems, such as nano- and microcarriers, developed for articular cartilage diseases.

Sucrose-based cryoprotective storage of extracellular vesicles

Advancements in extracellular vesicle (EV) studies necessitate the development of optimized storage conditions to ensure preservation of physical and biochemical characteristics. In this study, the most common buffer for EV storage (phosphate-buffered saline/PBS) was compared to a cryoprotective 5% sucrose solution. The size distribution and concentration of EVs from two different sources changed to a greater extent after -80 °C storage in PBS compared to the sucrose solution. Additionally, molecular surface protrusions and transmembrane proteins were more prevalent in EVs stored in the sucrose solution compared to those stored in PBS. This study demonstrates, for the first time, that distinct ring-like molecular complexes and cristae-like folded membranous structures are visible upon EV degradation. Taken together, the size, concentration, molecular surface extensions, and transmembrane proteins of EVs varied substantially based on the buffer used for -80 °C storage, suggesting that biocompatible cryoprotectants, such as sucrose, should be considered for EV studies.

Improving the ischemia-reperfusion injury in vascularized composite allotransplantation: Clinical experience and experimental implications

Long-time ischemia worsening transplant outcomes in vascularized composite allotransplantation (VCA) is often neglected. Ischemia-reperfusion injury (IRI) is an inevitable event that follows reperfusion after a period of cold static storage. The pathophysiological mechanism activates local inflammation, which is a barrier to allograft long-term immune tolerance. The previous publications have not clearly described the relationship between the tissue damage and ischemia time, nor the rejection grade. In this review, we found that the rejection episodes and rejection grade are usually related to the ischemia time, both in clinical and experimental aspects. Moreover, we summarized the potential therapeutic measures to mitigate the ischemia-reperfusion injury. Compare to static preservation, machine perfusion is a promising method that can keep VCA tissue viability and extend preservation time, which is especially beneficial for the expansion of the donor pool and better MHC-matching.

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.

miR-29a-3p in Exosomes from Heme Oxygenase-1 Modified Bone Marrow Mesenchymal Stem Cells Alleviates Steatotic Liver Ischemia-Reperfusion Injury in Rats by Suppressing Ferroptosis via Iron Responsive Element Binding Protein 2

Hepatic ischemia-reperfusion injury (IRI) is an inevitable result of liver surgery. Steatotic livers are extremely sensitive to IRI and have worse tolerance. Ferroptosis is considered to be one of the main factors of organ IRI. This study is aimed at exploring the role of ferroptosis in the effect of heme oxygenase-1-modified bone marrow mesenchymal stem cells (HO-1/BMMSCs) on steatotic liver IRI and its mechanism. An IRI model of a steatotic liver and a hypoxia reoxygenation (HR) model of steatotic hepatocytes (SHPs) were established. Rat BMMSCs were extracted and transfected with the Ho1 gene to establish HO-1/BMMSCs, and their exosomes were extracted by ultracentrifugation. Ireb2 was knocked down to verify its role in ferroptosis and cell injury in SHP-HR. Public database screening combined with quantitative real-time reverse transcription PCR identified microRNAs (miRNAs) targeting Ireb2 in HO-1/BMMSCs exosomes. miR-29a-3p mimic and inhibitor were used for functional verification experiments. Liver function, histopathology, terminal deoxynulceotidyl transferase nick-end-labeling staining, cell viability, mitochondrial membrane potential, and cell death were measured to evaluate liver tissue and hepatocyte injury. Ferroptosis was assessed by detecting the levels of IREB2, Fe²⁺, malondialdehyde, glutathione, lipid reactive oxygen species, glutathione peroxidase 4, prostaglandin-endoperoxide synthase 2 mRNA, and mitochondrial morphology. The results revealed that HO-1/BMMSCs improved liver tissue and hepatocyte injury and suppressed ferroptosis in vivo and in vitro. The expression of IREB2 was increased in steatotic liver IRI and SHP-HR. Knocking down Ireb2 reduced the level of Fe²⁺ and inhibited ferroptosis. HO-1/BMMSC exosomes reduced the expression of IREB2 and inhibited ferroptosis and cell damage. Furthermore, we confirmed high levels of miR-29a-3p in HO-1/BMMSCs exosomes. Overexpression of miR-29a-3p downregulated the expression of Ireb2 and inhibited ferroptosis. Downregulation of miR-29a-3p blocked the protective effect of HO-1/BMMSC exosomes on SHP-HR cell injury. In conclusion, ferroptosis plays an important role in HO-1/BMMSC-mediated alleviation of steatotic liver IRI. HO-1/BMMSCs could suppress ferroptosis by targeting Ireb2 via the exosomal transfer of miR-29a-3p.

Ischemic preconditioning-induced protective effect for promoting angiogenesis in renal ischemia-reperfusion injury by regulating miR-376c-3p/HIF-1α/VEGF axis in male rats

OBJECTIVE

Ischemic preconditioning (IPC) is defined as a well-established phenomenon in which brief exposure to sublethal episodes of ischemia and reperfusion induces a tolerance to injurious effects of prolonged ischemia by exploiting intrinsic defence mechanisms. The present study was performed to determine the protective effect of IPC on the rat renal ischemia-reperfusion injury (IRI) via miR-376c-3p/HIF-1α/VEGF axis.

METHODS

In vivo, these male Sprague-Dawley rats were treated by IRI and IPC. Meanwhile, these rats from different treatment groups were also injected subcutaneously with 2 nmol agomir-376c-3p and/or 10 nmol recombinant rat HIF-1α. At 72 h after reperfusion, serum samples were respectively collected for renal function. Besides, kidney tissues were harvested to observe renal morphology changes. Subsequently, the expression levels of CD31, HIF-1α and VEGF in the kidney tissues were measured using immunohistochemical staining, quantitative real-time PCR, as well as Western blotting analysis at the indicated time points after reperfusion. In vitro, HK-2 cells were used to detect the cell activity by CCK-8 and transfection of mir-376c-3p mimic in Hypoxia/Reoxygenation (H/R) group.

RESULTS

In vivo, the pathological changes were significantly relieved in the rats with IPC group, compared to the IRI group. Rats which were treated IPC significantly reduced the levels of blood urea nitrogen (BUN), serum creatinine (Scr) at 24 h after operation, compared to IRI group. After IPC treatment, the expression level of CD31 was obviously decreased, compared to IRI group. A total of differently expressed microRNAs were screened out by microRNA microarray assay in rat renal ischemia tissue, especially showing that miR-376c-3p was selected as the target miRNA. Compared to IRI group, the expression level of miR-376c-3p were obviously higher in IPC-treated group. Double-luciferase reporter assay demonstrated that miR-376c-3p directly targeted HIF-1α. In vitro, IPC significantly increased cell viability of HK-2, and promoted the angiogenesis via up-regulating miR-376c-3p/HIF-1α/VEGF axis. Furthermore, the expression level of HIF-1α was apparently decreased in HK-2 treated with H/R after miR-376c-3p mimic transfection respectively, as well as the increased expression level of VEGF.

CONCLUSIONS

Our study provided a novel insight for investigating the protective effect of IPC on renal IRI. Consequently, miR-376c-3p played an important role in renal IRI by promoting angiogenesis via targeting HIF-1α/VEGF pathway in male rats.

The emerging therapeutic potential of extracellular vesicles in trauma

Traumatic injury is a major cause of morbidity and mortality worldwide, despite significant advances in treatments. Most deaths occur either very early, through massive head trauma/CNS injury or exsanguination (despite advances in transfusion medicine), or later after injury often through multiple organ failure and secondary infection. Extracellular vesicles (EVs) are known to increase in the circulation after trauma and have been used to limited extent as diagnostic and prognostic markers. More intriguingly, EVs are now being investigated as both causes of pathologies post trauma, such as trauma-induced coagulopathy, and as potential treatments. In this review, we highlight what is currently known about the role and effects of EVs in various aspects of trauma, as well as exploring current literature from investigators who have begun to use EVs therapeutically to alter the physiology and pathology of traumatic insults. The potential effectiveness of using EVs therapeutically in trauma is supported by a large number of experimental studies, but there is still some way to go before we understand the complex effects of EVs in what is already a complex disease process.

Effects of Adipose-Derived Biogenic Nanoparticle-Associated microRNA-451a on Toll-like Receptor 4-Induced Cytokines

Extracellular vesicles (EVs) are cell-released nanoparticles that transfer biomolecular content between cells. Among EV-associated biomolecules, microRNAs (miRNAs/miRs) represent one of the most important modulators of signaling pathways in recipient cells. Previous studies have shown that EVs from adipose-derived mesenchymal stromal cells (MSCs) and adipose tissue modulate inflammatory pathways in macrophages. In this study, the effects of miRNAs that are abundant in adipose tissue EVs and other biogenic nanoparticles (BiNPs) were assessed in terms of altering Toll-like receptor 4 (TLR4)-induced cytokines. TLR-4 signaling in macrophages is often triggered by pathogen or damage-induced inflammation and is associated with several diseases. This study demonstrates that miR-451a, which is abundant in adipose tissue BiNPs, suppresses pro-inflammatory cytokines and increases anti-inflammatory cytokines associated with the TLR4 pathway. Therefore, miR-451a may be partially responsible for immunomodulatory effects of adipose tissue-derived BiNPs.

Intestinal ischemia‑reperfusion induces the release of IL‑17A to regulate cell inflammation, apoptosis and barrier damage

Intestinal ischemia-reperfusion (I/R) injury promotes the release of IL-17A, and previous studies have indicated that TGF-β activated kinase 1 (TAK1) is an important signaling molecule in the regulatory function of IL-17A. The present study aimed to explore the potential effects of IL-17A release in intestinal I/R injury, and to investigate the underlying regulatory mechanisms. Initially, the expression levels of TAK1 and JNK in a hypoxia/reoxygenation model were determined, and the effects of TAK1-knockdown on JNK phosphorylation and the viability, inflammation, apoptosis and barrier function of Caco-2 cells were assessed using Cell Counting Kit-8, reverse transcription-quantitative PCR, TUNEL and transepithelial electrical resistance assays, respectively. Subsequently, an antibody targeting IL-17A was used, and the effects of the IL-17A antibody on the expression levels of TAK1 as well as cell viability, inflammation, apoptosis and barrier function were determined. The results of the present study demonstrated that TAK1-knockdown markedly reduced JNK phosphorylation and improved the levels of cell viability, inflammation, apoptosis and barrier function via the MAPK signaling pathway. In addition, treatment with the IL-17A antibody inhibited the expression of TAK1, and reversed the aforementioned effects of TAK1 on Caco-2 cells. In conclusion, intestinal I/R induces the release of IL-17A to regulate cell viability, inflammation, apoptosis and barrier damage via the TAK1/MAPK signaling pathway.

Extracellular vesicles: mediators of intercellular communication in tissue injury and disease

Intercellular communication is a critical process that ensures cooperation between distinct cell types and maintains homeostasis. EVs, which were initially described as cellular debris and devoid of biological function, are now recognized as key components in cell-cell communication. EVs are known to carry multiple factors derived from their cell of origin, including cytokines and chemokines, active enzymes, metabolites, nucleic acids, and surface molecules, that can alter the behavior of recipient cells. Since the cargo of EVs reflects their parental cells, EVs from damaged and dysfunctional tissue environments offer an abundance of information toward elucidating the molecular mechanisms of various diseases and pathological conditions. In this review, we discuss the most recent findings regarding the role of EVs in the progression of cancer, metabolic disorders, and inflammatory lung diseases given the high prevalence of these conditions worldwide and the important role that intercellular communication between immune, parenchymal, and stromal cells plays in the development of these pathological states. We also consider the clinical applications of EVs, including the possibilities for their use as novel therapeutics. While intercellular communication through extracellular vesicles (EVs) is key for physiological processes and tissue homeostasis, injury and stress result in altered communication patterns in the tissue microenvironment. When left unchecked, EV-mediated interactions between stromal, immune, and parenchymal cells lead to the development of disease states Video Abstract.

Advances in Nanomaterials for Injured Heart Repair

Atherosclerotic cardiovascular disease (ASCVD) is one of the leading causes of mortality worldwide. Because of the limited regenerative capacity of adult myocardium to compensate for the loss of heart tissue after ischemic infarction, scientists have been exploring the possible mechanisms involved in the pathological process of ASCVD and searching for alternative means to regenerate infarcted cardiac tissue. Although numerous studies have pursued innovative solutions for reversing the pathological process of ASCVD and improving the effectiveness of delivering therapeutics, the translation of those advances into downstream clinical applications remains unsatisfactory because of poor safety and low efficacy. Recently, nanomaterials (NMs) have emerged as a promising new strategy to strengthen both the efficacy and safety of ASCVD therapy. Thus, a comprehensive review of NMs used in ASCVD treatment will be useful. This paper presents an overview of the pathophysiological mechanisms of ASCVD and the multifunctional mechanisms of NM-based therapy, including antioxidative, anti-inflammation and antiapoptosis mechanisms. The technological improvements of NM delivery are summarized and the clinical transformations concerning the use of NMs to treat ASCVD are examined. Finally, this paper discusses the challenges and future perspectives of NMs in cardiac regeneration to provide insightful information for health professionals on the latest advancements in nanotechnologies for ASCVD treatment.

Extracellular vesicle therapeutics from plasma and adipose tissue

Extracellular vesicles (EVs) are cell-released lipid-bilayer nanoparticles that contain biologically active cargo involved in physiological and pathological intercellular communication. In recent years, the therapeutic potential of EVs has been explored in various disease models. In particular, mesenchymal stromal cell-derived EVs have been shown to exert anti-inflammatory, anti-oxidant, anti-apoptotic, and pro-angiogenic properties in cardiovascular, metabolic and orthopedic conditions. However, a major drawback of EV-based therapeutics is scale-up issues due to extensive cell culture requirements and inefficient isolation protocols. An emerging alternative approach to time-consuming and costly cell culture expansion is to obtain therapeutic EVs directly from the body, for example, from plasma and adipose tissue. This review discusses isolation methods and therapeutic applications of plasma and adipose tissue-derived EVs, highlighting advantages and disadvantages compared to cell culture-derived ones.

Nanotheranostics for the Management of Hepatic Ischemia-Reperfusion Injury

Hepatic ischemia-reperfusion injury (IRI), in which an insufficient oxygen supply followed by reperfusion leads to an inflammatory network and oxidative stress in disease tissue to cause cell death, always occurs after liver transplantations and sections. Although pharmacological treatments favorably prevent or protect the liver against experimental IRI, there have been few successes in clinical applications for patient benefits because of the incomprehension of complicated IRI-induced signaling events as well as short blood circulation time, poor solubility, and severe side reactions of most antioxidants and anti-inflammatory drugs. Nanomaterials can achieve targeted delivery and controllable release of contrast agents and therapeutic drugs in desired hepatic IRI regions for enhanced imaging sensitivity and improved therapeutic effects, emerging as novel alternative approaches for hepatic IRI diagnosis and therapy. In this review, the application of nanotechnology is summarized in the management of hepatic IRI, including nanomaterial-assisted hepatic IRI diagnosis, nanoparticulate systems-mediated remission of reactive oxygen species-induced tissue injury, and nanoparticle-based targeted drug delivery systems for the alleviation of IRI-related inflammation. The current challenges and future perspectives of these nanoenabled strategies for hepatic IRI treatment are also discussed.

A Simple and Quick Method for Loading Proteins in Extracellular Vesicles

Extracellular vesicles (EVs) mediate intercellular transport of biomolecular cargo in the body, making them promising delivery vehicles for bioactive compounds. Genetic engineering of producer cells has enabled encapsulation of therapeutic proteins in EVs. However, genetic engineering approaches can be expensive, time-consuming, and incompatible with certain EV sources, such as human plasma and bovine milk. The goal of this study was to develop a quick, versatile, and simple method for loading proteins in EVs post-isolation. Proteins, including CRISPR associated protein 9 (Cas9), were bound to cationic lipids that were further complexed with MDA-MB-231 cell-derived EVs through passive incubation. Size-exclusion chromatography was used to remove components that were not complexed with EVs. The ability of EVs to mediate intracellular delivery of proteins was compared to conventional methods, such as electroporation and commercial protein transfection reagents. The results indicate that EVs retain native features following protein-loading and obtain similar levels of intracellular protein delivery as conventional methods, but display less toxicity. This method opens up opportunities for rapid exploration of EVs for protein delivery.

Multicenter validation of the liver graft assessment following transplantation (L-GrAFT) score for assessment of early allograft dysfunction

BACKGROUND & AIMS

Early allograft dysfunction (EAD) following liver transplantation (LT) negatively impacts graft and patient outcomes. Previously we reported that the liver graft assessment following transplantation (L-GrAFT₇) risk score was superior to binary EAD or the model for early allograft function (MEAF) score for estimating 3-month graft failure-free survival in a single-center derivation cohort. Herein, we sought to externally validate L-GrAFT₇, and compare its prognostic performance to EAD and MEAF.

METHODS

Accuracies of L-GrAFT₇, EAD, and MEAF were compared in a 3-center US validation cohort (n = 3,201), and a Consortium for Organ Preservation in Europe (COPE) normothermic machine perfusion (NMP) trial cohort (n = 222); characteristics were compared to assess generalizability.

RESULTS

Compared to the derivation cohort, patients in the validation and NMP trial cohort had lower recipient median MELD scores; were less likely to require pretransplant hospitalization, renal replacement therapy or mechanical ventilation; and had superior 1-year overall (90% and 95% vs. 84%) and graft failure-free (88% and 93% vs. 81%) survival, with a lower incidence of 3-month graft failure (7.4% and 4.0% vs. 11.1%; p <0.001 for all comparisons). Despite significant differences in cohort characteristics, L-GrAFT₇ maintained an excellent validation AUROC of 0.78, significantly superior to binary EAD (AUROC 0.68, p = 0.001) and MEAF scores (AUROC 0.72, p <0.001). In post hoc analysis of the COPE NMP trial, the highest tertile of L-GrAFT₇ was significantly associated with time to liver allograft (hazard ratio [HR] 2.17, p = 0.016), Clavien ≥IIIB (HR 2.60, p = 0.034) and ≥IVa (HR 4.99, p = 0.011) complications; post-LT length of hospitalization (p = 0.002); and renal replacement therapy (odds ratio 3.62, p = 0.016).

CONCLUSIONS

We have validated the L-GrAFT₇ risk score as a generalizable, highly accurate, individualized risk assessment of 3-month liver allograft failure that is superior to existing scores. L-GrAFT₇ may standardize grading of early hepatic allograft function and serve as a clinical endpoint in translational studies (www.lgraft.com).

LAY SUMMARY

Early allograft dysfunction negatively affects outcomes following liver transplantation. In independent multicenter US and European cohorts totaling 3,423 patients undergoing liver transplantation, the liver graft assessment following transplantation (L-GrAFT) risk score is validated as a superior measure of early allograft function that accurately discriminates 3-month graft failure-free survival and post-liver transplantation complications.

Brain metastases-derived extracellular vesicles induce binding and aggregation of low-density lipoprotein

BACKGROUND

Cancer cell-derived extracellular vesicles (EVs) have previously been shown to contribute to pre-metastatic niche formation. Specifically, aggressive tumors secrete pro-metastatic EVs that travel in the circulation to distant organs to modulate the microenvironment for future metastatic spread. Previous studies have focused on the interface between pro-metastatic EVs and epithelial/endothelial cells in the pre-metastatic niche. However, EV interactions with circulating components such as low-density lipoprotein (LDL) have been overlooked.

RESULTS

This study demonstrates that EVs derived from brain metastases cells (Br-EVs) and corresponding regular cancer cells (Reg-EVs) display different interactions with LDL. Specifically, Br-EVs trigger LDL aggregation, and the presence of LDL accelerates Br-EV uptake by monocytes, which are key components in the brain metastatic niche.

CONCLUSIONS

Collectively, these data are the first to demonstrate that pro-metastatic EVs display distinct interactions with LDL, which impacts monocyte internalization of EVs.