Therapeutic properties of stem cell-derived exosomes in ischemic heart disease

Exosomes and non-coding RNAs: Exploring their roles in human myocardial dysfunction

Myocardial dysfunction, characterized by impaired cardiac muscle function, arises from diverse etiologies, including coronary artery disease, myocardial infarction, cardiomyopathies, hypertension, and valvular heart disease. Recent advancements have highlighted the roles of exosomes and non-coding RNAs in the pathophysiology of myocardial dysfunction. Exosomes are small extracellular vesicles released by cardiac and other cells that facilitate intercellular communication through their molecular cargo, including ncRNAs. ncRNAs are known to play critical roles in gene regulation through diverse mechanisms, impacting oxidative stress, fibrosis, and other factors associated with myocardial dysfunction. Dysregulation of these molecules correlates with disease progression, presenting opportunities for therapeutic interventions. This review explores the mechanistic interplay between exosomes and ncRNAs, underscoring their potential as biomarkers and therapeutic agents in myocardial dysfunction. Emerging evidence supports the use of engineered exosomes and modified ncRNAs to enhance cardiac repair by targeting signaling pathways associated with fibrosis, apoptosis, and angiogenesis. Despite promising preclinical results, delivery, stability, and immunogenicity challenges remain. Further research is needed to optimize clinical translation. Understanding these intricate mechanisms may drive the development of innovative strategies for diagnosing and treating myocardial dysfunction, ultimately improving patient outcomes.

HuMSC-EVs Protect Endothelial Cells Against Hypoxia/Reoxygenation Injury by Inhibiting the Pannexin 1/p38-MAPK Pathway

Vascular endothelial cell dysfunction plays an important role in myocardial ischemia-reperfusion (I/R) injury, and pannexin 1 (Panx1), an ATP-permeable channel, is closely associated with the pathophysiological processes of I/R injury. The purpose of this study was to investigate the protective effects of human umbilical cord mesenchymal stromal cell-derived extracellular vesicles (HuMSC-EVs) and the underlying mechanism in a model of I/R injury. For the cellular model of I/R injury, human umbilical vein endothelial cells (HuVECs) were exposed to hypoxia/reoxygenation (H/R) conditions. The model cells were then treated with HuMSC-EVs, and the effects on cell survival and specific signaling activities were observed. The results showed that after H/R exposure, Panx1 expression and other markers of cellular damage were increased in HuVECs. However, treatment with HuMSC-EVs inhibited the H/R-induced increase in Panx1 expression and improved HuVEC survival. Mechanistically, HuMSC-EVs were found to inhibit the p38 mitogen-activated protein kinase (MAPK)-dependent apoptosis pathway, as evidenced by increased Bcl2 expression and reductions in p38 MAPK phosphorylation, Bax expression, and cleaved-caspase 3 expression. Together our data suggest that HuMSC-EVs alleviate H/R-induced apoptosis among HuVECs by inhibiting activity of the Panx1/p38-MAPK-dependent apoptosis pathway.

Ex Vivo Peptide Decoration Strategies on Stem Cell Surfaces for Augmenting Endothelium Interaction

Ischemic vascular diseases remain leading causes of disability and death. Although various clinical therapies have been tried, reperfusion injury is a major issue, occurring when blood recirculates at the damaged lesion. As an alternative approach, cell-based therapy has emerged. Mesenchymal stem cells (MSCs) are attractive cellular candidates due to their therapeutic capacities, including differentiation, safety, angiogenesis, and tissue repair. However, low levels of receptors/ligands limit targeted migration of stem cells. Thus, it is important to improve homing efficacy of transplanted MSCs toward damaged endothelium. Among various MSC modulations, ex vivo cell surface engineering could effectively augment homing efficiency by decorating MSC surfaces with alternative receptors/ligands, thereby facilitating intercellular interactions with the endothelium. Especially, exogenous decoration of peptides onto stem cell surfaces could provide appropriate functional signaling moieties to achieve sufficient MSC homing. Based on their protein-like functionalities, high modularity in molecular design, and high specific affinities and multivalency to target receptors, peptides could be representative surface-presentable moieties. Moreover, peptides feature a mild synthetic process, enabling precise control of amino acid composition and sequence. Such ex vivo stem cell surface engineering could be achieved primarily by hydrophobic interactions of the cellular bilayer with peptide-conjugated anchor modules and by covalent conjugation between peptides and available compartments in membranes. To this end, this review provides an overview of currently available peptide-mediated, ex vivo stem cell surface engineering strategies for enhancing MSC homing efficiency by facilitating interactions with endothelial cells. Stem cell surface engineering techniques using peptide-based bioconjugates have the potential to revolutionize current vascular disease treatments while addressing their technical limitations.

Advances in injectable hydrogels for radiation-induced heart disease

Radiological heart damage (RIHD) is damage caused by unavoidable irradiation of the heart during chest radiotherapy, with a long latency period and a progressively increasing proportion of delayed cardiac damage due to conventional doses of chest radiotherapy. There is a risk of inducing diseases such as acute/chronic pericarditis, myocarditis, delayed myocardial fibrosis and damage to the cardiac conduction system in humans, which can lead to myocardial infarction or even death in severe cases. This paper details the pathogenesis of RIHD and gives potential targets for treatment at the molecular and cellular level, avoiding the drawbacks of high invasiveness and immune rejection due to drug therapy, medical device implantation and heart transplantation. Injectable hydrogel therapy has emerged as a minimally invasive tissue engineering therapy to provide necessary mechanical support to the infarcted myocardium and to act as a carrier for various bioactive factors and cells to improve the cellular microenvironment in the infarcted area and induce myocardial tissue regeneration. Therefore, this paper combines bioactive factors and cellular therapeutic mechanisms with injectable hydrogels, presents recent advances in the treatment of cardiac injury after RIHD with different injectable gels, and summarizes the therapeutic potential of various types of injectable hydrogels as a potential solution.

Exosomes-Mediated Signaling Pathway: A New Direction for Treatment of Organ Ischemia-Reperfusion Injury

Ischemia reperfusion (I/R) is a common pathological process which occurs mostly in organs like the heart, brain, kidney, and lung. The injury caused by I/R gradually becomes one of the main causes of fatal diseases, which is an urgent clinical problem to be solved. Although great progress has been made in therapeutic methods, including surgical, drug, gene therapy, and transplant therapy for I/R injury, the development of effective methods to cure the injury remains a worldwide challenge. In recent years, exosomes have attracted much attention for their important roles in immune response, antigen presentation, cell migration, cell differentiation, and tumor invasion. Meanwhile, exosomes have been shown to have great potential in the treatment of I/R injury in organs. The study of the exosome-mediated signaling pathway can not only help to reveal the mechanism behind exosomes promoting reperfusion injury recovery, but also provide a theoretical basis for the clinical application of exosomes. Here, we review the research progress in utilizing various exosomes from different cell types to promote the healing of I/R injury, focusing on the classical signaling pathways such as PI3K/Akt, NF-κB, Nrf2, PTEN, Wnt, MAPK, toll-like receptor, and AMPK. The results suggest that exosomes regulate these signaling pathways to reduce oxidative stress, regulate immune responses, decrease the expression of inflammatory cytokines, and promote tissue repair, making exosomes a competitive emerging vector for treating I/R damage in organs.

Stem Cell-Derived Extracellular Vesicles for Cancer Therapy and Tissue Engineering Applications

Recently, stem cells and their secretomes have attracted great attention in biomedical applications, particularly extracellular vesicles (EVs). EVs are secretomes of cells for cell-to-cell communication. They play a role as intercellular messengers as they carry proteins, nucleic acids, lipids, and therapeutic agents. They have also been utilized as drug-delivery vehicles due to their biocompatibility, low immunogenicity, stability, targetability, and engineerable properties. The therapeutic potential of EVs can be further enhanced by surface engineering and modification using functional molecules such as aptamers, peptides, and antibodies. As a consequence, EVs hold great promise as effective delivery vehicles for enhancing treatment efficacy while avoiding side effects. Among various cell types that secrete EVs, stem cells are ideal sources of EVs because stem cells have unique properties such as self-renewal and regenerative potential for transplantation into damaged tissues that can facilitate their regeneration. However, challenges such as immune rejection and ethical considerations remain significant hurdles. Stem cell-derived EVs have been extensively explored as a cell-free approach that bypasses many challenges associated with cell-based therapy in cancer therapy and tissue regeneration. In this review, we summarize and discuss the current knowledge of various types of stem cells as a source of EVs, their engineering, and applications of EVs, focusing on cancer therapy and tissue engineering.

Mesenchymal Stem Cell-Derived Long Noncoding RNAs in Cardiac Injury and Repair

Cardiac injury, such as myocardial infarction and heart failure, remains a significant global health burden. The limited regenerative capacity of the adult heart poses a challenge for restoring its function after injury. Mesenchymal stem cells (MSCs) have emerged as promising candidates for cardiac regeneration due to their ability to differentiate into various cell types and secrete bioactive molecules. In recent years, attention has been given to noncoding RNAs derived from MSCs, particularly long noncoding RNAs (lncRNAs), and their potential role in cardiac injury and repair. LncRNAs are RNA molecules that do not encode proteins but play critical roles in gene regulation and cellular responses including cardiac repair and regeneration. This review focused on MSC-derived lncRNAs and their implications in cardiac regeneration, including their effects on cardiac function, myocardial remodeling, cardiomyocyte injury, and angiogenesis. Understanding the molecular mechanisms of MSC-derived lncRNAs in cardiac injury and repair may contribute to the development of novel therapeutic strategies for treating cardiovascular diseases. However, further research is needed to fully elucidate the potential of MSC-derived lncRNAs and address the challenges in this field.

Advances in Purification, Modification, and Application of Extracellular Vesicles for Novel Clinical Treatments

Extracellular vesicles (EV) are membrane vesicles surrounded by a lipid bilayer membrane and include microvesicles, apoptotic bodies, exosomes, and exomeres. Exosome-encapsulated microRNAs (miRNAs) released from cancer cells are involved in the proliferation and metastasis of tumor cells via angiogenesis. On the other hand, mesenchymal stem cell (MSC) therapy, which is being employed in regenerative medicine owing to the ability of MSCs to differentiate into various cells, is due to humoral factors, including messenger RNA (mRNA), miRNAs, proteins, and lipids, which are encapsulated in exosomes derived from transplanted cells. New treatments that advocate cell-free therapy using MSC-derived exosomes will significantly improve clinical practice. Therefore, using highly purified exosomes that perform their original functions is desirable. In this review, we summarized advances in the purification, modification, and application of EVs as novel strategies to treat some diseases.

Regulation of Extracellular Vesicle-Mediated Immune Responses against Antigen-Specific Presentation

Extracellular vesicles (EVs) produced by various immune cells, including B and T cells, macrophages, dendritic cells (DCs), natural killer (NK) cells, and mast cells, mediate intercellular communication and have attracted much attention owing to the novel delivery system of molecules in vivo. DCs are among the most active exosome-secreting cells of the immune system. EVs produced by cancer cells contain cancer antigens; therefore, the development of vaccine therapy that does not require the identification of cancer antigens using cancer-cell-derived EVs may have significant clinical implications. In this review, we summarise the molecular mechanisms underlying EV-based immune responses and their therapeutic effects on tumour vaccination.

The Role of Angiogenesis and Arteriogenesisin Myocardial Infarction and Coronary Revascularization

Surgical myocardial revascularization is associated with long-term survival benefit in patients with multivessel coronary artery disease. However, the exact biological mechanisms underlying the clinical benefits of myocardial revascularization have not been elucidated yet. Angiogenesis and arteriogenesis biologically leading to vascular collateralization are considered one of the endogenous mechanisms to preserve myocardial viability during ischemia, and the presence of coronary collateralization has been regarded as one of the predictors of long-term survival in patients with coronary artery disease (CAD). Some experimental studies and indirect clinical evidence on chronic CAD confirmed an angiogenetic response induced by myocardial revascularization and suggested that revascularization procedures could constitute an angiogenetic trigger per se. In this review, the clinical and basic science evidence regarding arteriogenesis and angiogenesis in both CAD and coronary revascularization is analyzed with the aim to better elucidate their significance in the clinical arena and potential therapeutic use.