The Use of Mesenchymal Stem Cells and their Derived Extracellular Vesicles in Cardiovascular Disease Treatment

Therapeutic Application of Extracellular Vesicles Derived from Mesenchymal Stem Cells in Domestic Animals

Recently, the therapeutic potential of extracellular vesicles (EVs) derived from mesenchymal stem cells (MSCs) has been extensively studied in both human and veterinary medicine. EVs are nano-sized particles containing biological components commonly found in other biological materials. For that reason, EV isolation and characterization are critical to draw precise conclusions during their investigation. Research on EVs within veterinary medicine is still considered in its early phases, yet numerous papers were published in recent years. The conventional adult tissues for deriving MSCs include adipose tissue and bone marrow. Nonetheless, alternative sources such as synovial fluid, endometrium, gingiva, and milk have also been intermittently used. Fetal adnexa are amniotic membrane/fluid, umbilical cord and Wharton's jelly. Cells derived from fetal adnexa exhibit an intermediate state between embryonic and adult cells, demonstrating higher proliferative and differentiative potential and longer telomeres compared to cells from adult tissues. Summarized here are the principal and recent preclinical and clinical studies performed in domestic animals such as horse, cattle, dog and cat. To minimize the use of antibiotics and address the serious issue of antibiotic resistance as a public health concern, they will undoubtedly also be utilized in the future to treat infections in domestic animals. A number of concerns, including large-scale production with standardization of EV separation and characterization techniques, must be resolved for clinical application.

Small extracellular vesicles derived from microRNA-22-3p-overexpressing mesenchymal stem cells protect retinal ganglion cells by regulating MAPK pathway

Glaucoma is the leading cause of irreversible blindness and is characterized by progressive retinal ganglion cell (RGC) loss and retinal nerve fiber layer thinning. Currently, no existing treatment is effective for the preservation of RGCs. MicroRNA-22-3p (miR22) and small extracellular vesicles derived from mesenchymal stem cells (MSC-sEVs) have neuroprotective effects. In this study, we apply miR22-overexpressing MSC-sEVs in an N-methyl-D-aspartic acid (NMDA)-induced RGC injury model to assess their short-term therapeutic effects and explore the underlying mechanisms. We find that mice in the miR22-sEVs-treated group have thicker retinas, fewer apoptotic cells, more reserved RGCs, better retinal function, and lower expression levels of Bax and caspase-3. MiR22-sEVs treatment promotes viability, inhibits apoptosis and inhibits Bax and caspase-3 expression in RGC-5 cells. MiR22 targets mitogen-activated protein kinase kinase kinase 12 to inhibit apoptosis by regulating the mitogen-activated protein kinase (MAPK) signaling pathway. Collectively, our results suggest that miR22-sEVs ameliorate NMDA-induced RGC injury through the inhibition of MAPK signaling pathway-mediated apoptosis, providing a potential therapy for glaucoma and other diseases that involve RGC damage.

Efficacy and safety of mesenchymal stem cell-derived microvesicles in mouse inflammatory arthritis

OBJECTIVE

To determine the effective and safe intravenous doses of mesenchymal stem cells (MSCs)-derived microvesicles (MVs) and to elucidate the possible causes of death in mice receiving high-dose MVs.

METHODS

MVs were isolated from human MSCs by gradient centrifugation. Mice with collagen-induced arthritis were treated with different doses of intravenous MVs or MSCs. Arthritis severity, white blood cell count, and serum C-reactive protein levels were measured. To assess the safety profile of MSCs and MVs, mice were treated with different doses of MSCs and MVs, and LD50 was calculated. Mouse lungs and heart were assessed by live fluorescence imaging, histopathological measurements, and immunohistochemistry to explore the possible causes of death. Serum concentrations of cTnT, cTnI, and CK-MB were determined by ELISA. With the H9C2 cardiomyocyte cell line,  cellular uptake of MVs was observed using confocal microscopy and cell toxicity was assessed by CCK-8 and flow cytometry.

RESULTS

Intravenous treatment with MSCs and MVs alleviated inflammatory arthritis, while high doses of MSCs and MVs were lethal. Mice receiving a maximum dose of MSCs (0.1 mL of MSCs at 109/mL) died immediately, while mice receiving a maximum dose of MVs (0.1 mL of MVs at 1012/mL) exhibited tears, drooling, tachycardia, shortness of breath, unbalanced rollover, bouncing, circular crawling, mania, and death. Some mice died after exhibiting convulsions and other symptoms. All mice died shortly after injecting the maximum dose of MSCs. Histologically, mice receiving high doses of MSCs frequently developed pulmonary embolism, while those receiving high doses of MVs died of myocardial infarction. Consistently, the serum levels of cTnT, cTnI, and CK-MB were significantly increased in the MVs-treated group (P < 0.05). The LD50 of intravenous MVs was 1.60 × 1012/kg. Further, MVs could enter the cell. High doses of MVs induced cell apoptosis, though low concentrations of MVs induced cell proliferation.

CONCLUSIONS

Appropriate dosages of MVs and MSCs are effective treatments for inflammatory arthritis while MVs and MSCs overdose is unsafe by causing cardiopulmonary complications.

Obesity blunts amelioration of cardiac hypertrophy and fibrosis by human mesenchymal stem/stromal cell-derived extracellular vesicles

Renovascular hypertension (RVH) can induce cardiac damage that is reversible using adipose tissue-derived mesenchymal stromal/stem cells (A-MSCs). However, A-MSCs isolated from patients with obesity are less effective than lean-A-MSC in blunting hypertensive cardiomyopathy in mice with RVH. We tested the hypothesis that this impairment extends to their obese A-MSC-extracellular vesicles (EVs) progeny. MSCs were harvested from the subcutaneous fat of obese and lean human subjects, and their EVs were collected and injected into the aorta of mice 2 wk after renal artery stenosis or sham surgery. Cardiac left ventricular (LV) function was studied with MRI 2 wk later, and myocardial tissue ex vivo. Blood pressure, LV myocardial wall thickness, mass, and fibrosis that were elevated in RVH mice were suppressed only by lean EVs. Hence, human A-MSC-derived lean EVs are more effective than obese EVs in blunting hypertensive cardiac injury in RVH mice. These observations highlight impaired paracrine repair potency of endogenous MSCs in patients with obesity.NEW & NOTEWORTHY Injection of A-MSC-derived EVs harvested from patients who are lean can resolve myocardial injury in mice with experimental renovascular hypertension more effectively than A-MSC-derived EVs from patients with obesity. These observations underscore and might have important ramifications for the self-healing capacity of patients with obesity and for the use of autologous EVs as a regenerative tool.

Mesenchymal Stem Cells: Generalities and Clinical Significance in Feline and Canine Medicine

Mesenchymal stem cells (MSCs) are multipotent cells: they can proliferate like undifferentiated cells and have the ability to differentiate into different types of cells. A considerable amount of research focuses on the potential therapeutic benefits of MSCs, such as cell therapy or tissue regeneration, and MSCs are considered powerful tools in veterinary regenerative medicine. They are the leading type of adult stem cells in clinical trials owing to their immunosuppressive, immunomodulatory, and anti-inflammatory properties, as well as their low teratogenic risk compared with pluripotent stem cells. The present review details the current understanding of the fundamental biology of MSCs. We focus on MSCs' properties and their characteristics with the goal of providing an overview of therapeutic innovations based on MSCs in canines and felines.

Human Umbilical Cord Mesenchymal Stem Cell-Derived Exosomes Attenuate Myocardial Infarction Injury via miR-24-3p-Promoted M2 Macrophage Polarization

Exosomes derived from human umbilical cord mesenchymal stem cells (UMSC-Exos) have shown encouraging effects in regulating inflammation and attenuating myocardial injury. Macrophages are regulated dynamically in response to environmental cues. However, the underlying mechanisms by which UMSC-Exos regulate macrophage polarization are still not well understood. Herein, it is aimed to explore the effects of UMSC-Exos on macrophage polarization and their roles in cardiac repair after myocardial infarction (MI). These results show that UMSC-Exos improve cardiac function by increasing M2 macrophage polarization and reducing excessive inflammation. RNA-sequencing results identify Plcb3 as a key gene involved in UMSC-Exo-facilitated M2 macrophage polarization. Further bioinformatic analysis identifies exosomal miR-24-3p as a potential effector mediating Plcb3 downregulation in macrophages. Increasing miR-24-3p expression in macrophages effectively enhances M2 macrophage polarization by suppressing Plcb3 expression and NF-κB pathway activation in the inflammatory environment. Furthermore, reducing miR-24-3p expression in UMSC-Exos attenuates the effects of UMSC-Exos on M2 macrophage polarization. This study demonstrates that the cardiac therapeutic effects of UMSC-Exos are at least partially through promoting M2 macrophage polarization in an inflammatory microenvironment. Mechanistically, exosomal miR-24-3p is found to inhibit Plcb3 expression and NF-κB pathway activation to promote M2 macrophage polarization.

Mesenchymal Stromal/Stem Cells and Their Extracellular Vesicles Application in Acute and Chronic Inflammatory Liver Diseases: Emphasizing on the Anti-Fibrotic and Immunomodulatory Mechanisms

Various factors, including viral and bacterial infections, autoimmune responses, diabetes, drugs, alcohol abuse, and fat deposition, can damage liver tissue and impair its function. These factors affect the liver tissue and lead to acute and chronic liver damage, and if left untreated, can eventually lead to cirrhosis, fibrosis, and liver carcinoma. The main treatment for these disorders is liver transplantation. Still, given the few tissue donors, problems with tissue rejection, immunosuppression caused by medications taken while receiving tissue, and the high cost of transplantation, liver transplantation have been limited. Therefore, finding alternative treatments that do not have the mentioned problems is significant. Cell therapy is one of the treatments that has received a lot of attention today. Hepatocytes and mesenchymal stromal/stem cells (MSCs) are used in many patients to treat liver-related diseases. In the meantime, the use of mesenchymal stem cells has been studied more than other cells due to their favourable characteristics and has reduced the need for liver transplantation. These cells increase the regeneration and repair of liver tissue through various mechanisms, including migration to the site of liver injury, differentiation into liver cells, production of extracellular vesicles (EVs), secretion of various growth factors, and regulation of the immune system. Notably, cell therapy is not entirely excellent and has problems such as cell rejection, undesirable differentiation, accumulation in unwanted locations, and potential tumorigenesis. Therefore, the application of MSCs derived EVs, including exosomes, can help treat liver disease and prevent its progression. Exosomes can prevent apoptosis and induce proliferation by transferring different cargos to the target cell. In addition, these vesicles have been shown to transport hepatocyte growth factor (HGF) and can promote the hepatocytes'(one of the most important cells in the liver parenchyma) growths.

A Comparative Study on the Effect of Exosomes Secreted by Mesenchymal Stem Cells Derived from Adipose and Bone Marrow Tissues in the Treatment of Osteoarthritis-Induced Mouse Model

BACKGROUND

Exosomes as extracellular vesicles (EVs) are nanoscale intercellular messengers secreted from cells to deliver biological signals. Today, exosomes have become a new field of research in regenerative medicine and are considered as potential therapies to control inflammation and wound healing and enhance and improve healing in many diseases. Given the global burden of osteoarthritis (OA) as the fastest-growing health condition and one of the major causes of physical disability in the aging population, research to establish EVs as therapeutic products can meet the basic clinical needs in the management of osteoarthritis and provide a therapeutic solution.

OBJECTIVES

The present study is aimed at evaluating the regenerative potentials of the exosomes secreted from adipose and bone marrow tissue-derived mesenchymal stem cells (AD- and BM-MSCs) in ameliorating the symptoms of OA.

METHOD

In this experimental study, AD- and BM-MSCs were isolated and cultured in the laboratory until passage 3. Finally, these cells' secreted exosomes were isolated from their conditioned medium. Ciprofloxacin-induced OA mouse models underwent intra-articular injection of exosomes from AD-MSCs and BM-MSCs. Finally, the expression levels of collagen I and II, sox9, and aggrecan genes using real-time PCR, histological analysis, and immunohistochemical (IHC) studies were performed.

RESULTS

Real-time PCR data showed that although the expression level of collagen type II was lower in both exosome-treated groups than the normal, but it was significantly increased in comparison with the sham and OA, with higher expression in BM-Exo rather than AD-Exo group. Similarly, the histological staining and IHC results have provided almost identical data, emphasizing on better therapeutic effect of BM-MSCs-exosome than AD-MSCs-exosome.

CONCLUSION

BM-MSCs secreted exosomes in comparison with AD-MSCs could be considered as a better therapeutic option to improve osteoarthritis and exhibit potential as a disease-modifying osteoarthritis cell-free product.

Exosomes of Mesenchymal Stem Cells as a Proper Vehicle for Transfecting miR-145 into the Breast Cancer Cell Line and Its Effect on Metastasis

Background

Despite recent advances in scientific knowledge and clinical practice, management, and treatment of breast cancer, as one of the leading causes of female mortality, breast cancer remains a major burden. Recently, methods employing stem cells and their derivatives, i.e., exosomes, in gene-based therapies hold great promise. Since these natural nanovesicles are able to transmit crucial cellular information which can be engineered to have robust delivery and targeting capacity, they are considered one of the modes of intercellular communication. miR-145, one of the downregulated microRNAs (miRNAs) in various cancers, can regulate tumor cell invasion, metastasis, apoptosis, and proliferation and stem cell differentiation.

Objectives

The aim of this study was to investigate the role of exosomes secreted from adipose tissue-derived mesenchymal stem cells (MSCs) for miR-145 transfection into breast cancer cells in order to weaken their expansion and metastasis.

Methods

Here, we exploited the exosomes from adipose tissue-derived mesenchymal stem cells (MSC-Exo) to deliver miR-145 in the T-47D breast cancer cell line. Lentiviral vectors of miR-145-pLenti-III-enhanced green fluorescent protein (eGFP) and empty pLenti-III-eGFP as the backbone were used to transfect MSCs and T-47D cells. In order to find the efficiency of exosomes as a delivery vehicle, the expression level of some miR-145 target genes, including Rho-Associated Coiled-Coil Containing Protein Kinase 1 (ROCK1), Erb-B2 Receptor Tyrosine Kinase 2 (ERBB2), Matrix Metalloproteinase 9 (MMP9), and Tumor Protein p53 (TP53), was compared in all treatment groups (T-47D cells treated by miR-145-transfected MSCs and their derivatives or their backbone) and control group (untransfected T-47D cells) using real-time PCR.

Results

The obtained data represented the inhibitory effect of miR-145 on apoptosis induction and metastasis in both direct miR-treated groups. However, exosome-mediated delivery caused an improved anticancer property of miR-145.

Conclusion

Restoration of miR-145 using MSC-Exo can be considered a potential novel therapeutic strategy in breast cancer in the future.

Extracellular Vesicles of Mesenchymal Stem Cells: Therapeutic Properties Discovered with Extraordinary Success

Mesenchymal stem cells (MSCs), the cells distributed in the stromas of the body, are known for various properties including replication, the potential of various differentiations, the immune-related processes including inflammation. About two decades ago, these cells were shown to play relevant roles in the therapy of numerous diseases, dependent on their immune regulation and their release of cytokines and growth factors, with ensuing activation of favorable enzymes and processes. Such discovery induced great increase of their investigation. Soon thereafter, however, it became clear that therapeutic actions of MSCs are risky, accompanied by serious drawbacks and defects. MSC therapy has been therefore reduced to a few diseases, replaced for the others by their extracellular vesicles, the MSC-EVs. The latter vesicles recapitulate most therapeutic actions of MSCs, with equal or even better efficacies and without the serious drawbacks of the parent cells. In addition, MSC-EVs are characterized by many advantages, among which are their heterogeneities dependent on the stromas of origin, the alleviation of cell aging, the regulation of immune responses and inflammation. Here we illustrate the MSC-EV therapeutic effects, largely mediated by specific miRNAs, covering various diseases and pathological processes occurring in the bones, heart and vessels, kidney, and brain. MSC-EVs operate also on the development of cancers and on COVID-19, where they alleviate the organ lesions induced by the virus. Therapy by MSC-EVs can be improved by combination of their innate potential to engineering processes inducing precise targeting and transfer of drugs. The unique properties of MSC-EVs explain their intense studies, carried out with extraordinary success. Although not yet developed to clinical practice, the perspectives for proximal future are encouraging.

The Mystery of Red Blood Cells Extracellular Vesicles in Sleep Apnea with Metabolic Dysfunction

Sleep is very important for overall health and quality of life, while sleep disorder has been associated with several human diseases, namely cardiovascular, metabolic, cognitive, and cancer-related alterations. Obstructive sleep apnea (OSA) is the most common respiratory sleep-disordered breathing, which is caused by the recurrent collapse of the upper airway during sleep. OSA has emerged as a major public health problem and increasing evidence suggests that untreated OSA can lead to the development of various diseases including neurodegenerative diseases. In addition, OSA may lead to decreased blood oxygenation and fragmentation of the sleep cycle. The formation of free radicals or reactive oxygen species (ROS) can emerge and react with nitric oxide (NO) to produce peroxynitrite, thereby diminishing the bioavailability of NO. Hypoxia, the hallmark of OSA, refers to a decline of tissue oxygen saturation and affects several types of cells, playing cell-to-cell communication a vital role in the outcome of this interplay. Red blood cells (RBCs) are considered transporters of oxygen and nutrients to the tissues, and these RBCs are important interorgan communication systems with additional functions, including participation in the control of systemic NO metabolism, redox regulation, blood rheology, and viscosity. RBCs have been shown to induce endothelial dysfunction and increase cardiac injury. The mechanistic links between changes of RBC functional properties and cardiovascular are largely unknown. Extracellular vesicles (EVs) are secreted by most cell types and released in biological fluids both under physiological and pathological conditions. EVs are involved in intercellular communication by transferring complex cargoes including proteins, lipids, and nucleic acids from donor cells to recipient cells. Advancing our knowledge about mechanisms of RBC-EVs formation and their pathophysiological relevance may help to shed light on circulating EVs and to translate their application to clinical practice. We will focus on the potential use of RBC-EVs as valuable diagnostic and prognostic biomarkers and state-specific cargoes, and possibilities as therapeutic vehicles for drug and gene delivery. The use of RBC-EVs as a precision medicine for the diagnosis and treatment of the patient with sleep disorder will improve the prognosis and the quality of life in patients with cardiovascular disease (CVD).

FO-SPR biosensor calibrated with recombinant extracellular vesicles enables specific and sensitive detection directly in complex matrices

Extracellular vesicles (EVs) have drawn huge attention for diagnosing myriad of diseases, including cancer. However, the EV detection and analyses procedures often lack much desired sample standardization. To address this, we used well-characterized recombinant EVs (rEVs) for the first time as a biological reference material in developing a fiber optic surface plasmon resonance (FO-SPR) bioassay. In this context, EV binding on the FO-SPR probes was achieved only with EV-specific antibodies (e.g. anti-CD9 and anti-CD63) but not with non-specific anti-IgG. To increase detection sensitivity, we tested six different combinations of EV-specific antibodies in a sandwich bioassay. Calibration curves were generated with two most effective combinations (anti-CD9/^Banti-CD81 and anti-CD63/^Banti-CD9), resulting in 10³ and 10⁴ times higher sensitivity than the EV concentration in human blood plasma from healthy or cancer patients, respectively. Additionally, by using anti-CD63/^Banti-CD9, we detected rEVs spiked in cell culture medium and HEK293 endogenous EVs in the same matrix without any prior EV purification or enrichment. Lastly, we selectively captured breast cancer cell EVs spiked in blood plasma using anti-EpCAM antibody on the FO-SPR surface. The obtained results combined with FO-SPR real-time monitoring, fast response time and ease of operation, demonstrate its outstanding potential for EV quantification and analysis.

Effect of gingival mesenchymal stem cell-derived exosomes on inflammatory macrophages in a high-lipid microenvironment

OBJECTIVE

The aim of this study was to examine the effect of gingival mesenchymal stem cells derived exosomes (GMSC-Exos) on lipopolysaccharide/interferon-gamma (LPS/INF-γ)-induced inflammatory macrophages in a high-lipid microenvironment.

MATERIALS AND METHODS

Exosomes were obtained by culturing gingival mesenchymal stem cells (GMSCs) in alpha-MEM with exosome-free fetal bovine serum for 48 h. The control group was produced in vitro by inducing human acute monocytic leukemia cells (THP-1 cells) into naïve macrophages (M0). Inflammatory macrophages (M1) were made by activating M0 macrophages with LPS/IFN-γ. These M1 macrophages were treated with oxidized low-density lipoprotein (ox-LDL) to create the high-lipid group, of which some macrophages were further treated with GMSC-Exos for 24 h to form the GMSC-Exos group. Supernatants were collected, and total RNA were extracted for downstream analysis. The expression of surface markers in macrophages were analyzed by flow cytometry. The lipid accumulation level was assessed by oil red O staining.

RESULTS

Exosomes were successfully isolated from GMSC medium. The GMSC-Exos group showed lower Tumor Necrosis Factor-α (TNF-α), Interleukin-6 (IL-6), Interleukin-1β (IL-1β), and cluster of differentiation 86 (CD86) expression levels than the high-lipid group, and the highest levels of Interleukin-10 (IL-10) among all groups. The GMSC-Exos group showed significant reductions in TNF-α levels than the high-lipid group, and significant escalations in IL-10 levels than the other two groups. Oil red o Staining showed that lipid accumulation in macrophages was inhibited in the GMSC-Exos group.

CONCLUSIONS

GMSC-Exos reduce the release level and expression of inflammatory factors, inhibit lipid accumulation, and promote the polarization of pro-inflammatory macrophages into anti-inflammatory phenotype in a high-lipid microenvironment.

News About the Extracellular Vesicles from Mesenchymal Stem Cells: Functions, Therapy and Protection from COVID-19

This is a Commentary of a review about extracellular vesicles of immune cells published two years ago in Clinical and Experimental Immunology, a prestigious journal of the field. The aim is to establish whether, and to what extent, results in scientific area of the review have been extended and strengthened by innovative findings of considerable interest. The analysis of the recently published results has revealed that in various areas of the review developments have occurred. However, innovative findings have been only about the extracellular vesicles secreted by mesenchymal stem cells, usually indicated as MSC-EVs. Based on these findings, the Commentary has been focused on recent MSC-EVs findings presented in three Sections dealing with 1. recently appeared, relevant functions of the latter vesicles; 2. therapeutic processes developed according well known criteria, however innovative in many respects; and 3. protection of COVID-19 disease patients from organ lesions induced by the specific virus, SARS-CoV-2, during the disease. As everybody knows, the COVID-19 pandemic started at the end of 2019, thus after the publication of the aforementioned review. Data of Section 3 are therefore innovative, of great potential interest also at the clinical level, applied by translational medicine to various organs, from lung to brain, heart, kidney, immune and other cells. In view of its relevance, the author expects that research and medical use of MSC-EV, active at present, will be further developed, acquiring additional relevance in the near future.