Antifibrotic effects and mechanisms of mesenchymal stem cell-derived exosomes in a systemic sclerosis mouse model: Possible contribution of miR-196b-5p

Exosomal microRNA-Based therapies for skin diseases

Based on engineered cell/exosome technology and various skin-related animal models, exosomal microRNA (miRNA)-based therapies derived from natural exosomes have shown good therapeutic effects on nine skin diseases, including full-thickness skin defects, diabetic ulcers, skin burns, hypertrophic scars, psoriasis, systemic sclerosis, atopic dermatitis, skin aging, and hair loss. Comparative experimental research showed that the therapeutic effect of miRNA-overexpressing exosomes was better than that of their natural exosomes. Using a dual-luciferase reporter assay, the targets of all therapeutic miRNAs in skin cells have been screened and confirmed. For these nine types of skin diseases, a total of 11 animal models and 21 exosomal miRNA-based therapies have been developed. This review provides a detailed description of the animal models, miRNA therapies, disease evaluation indicators, and treatment results of exosomal miRNA therapies, with the aim of providing a reference and guidance for future clinical trials. There is currently no literature on the merits or drawbacks of miRNA therapies compared with standard treatments.

Understanding exosomes: Part 2-Emerging leaders in regenerative medicine

Exosomes are the smallest subset of extracellular signaling vesicles secreted by most cells with the ability to communicate with other tissues and cell types over long distances. Their use in regenerative medicine has gained tremendous momentum recently due to their ability to be utilized as therapeutic options for a wide array of diseases/conditions. Over 5000 publications are currently being published yearly on this topic, and this number is only expected to dramatically increase as novel therapeutic strategies continue to be developed. Today exosomes have been applied in numerous contexts including neurodegenerative disorders (Alzheimer's disease, central nervous system, depression, multiple sclerosis, Parkinson's disease, post-traumatic stress disorders, traumatic brain injury, peripheral nerve injury), damaged organs (heart, kidney, liver, stroke, myocardial infarctions, myocardial infarctions, ovaries), degenerative processes (atherosclerosis, diabetes, hematology disorders, musculoskeletal degeneration, osteoradionecrosis, respiratory disease), infectious diseases (COVID-19, hepatitis), regenerative procedures (antiaging, bone regeneration, cartilage/joint regeneration, osteoarthritis, cutaneous wounds, dental regeneration, dermatology/skin regeneration, erectile dysfunction, hair regrowth, intervertebral disc repair, spinal cord injury, vascular regeneration), and cancer therapy (breast, colorectal, gastric cancer and osteosarcomas), immune function (allergy, autoimmune disorders, immune regulation, inflammatory diseases, lupus, rheumatoid arthritis). This scoping review is a first of its kind aimed at summarizing the extensive regenerative potential of exosomes over a broad range of diseases and disorders.

Mesenchymal stem cell-based therapy for autoimmune-related fibrotic skin diseases-systemic sclerosis and sclerodermatous graft-versus-host disease

BACKGROUND

Systemic sclerosis (SSc) and sclerodermatous graft-versus-host disease (Scl-GVHD)-characterized by similar developmental fibrosis, vascular abnormalities, and innate and adaptive immune response, resulting in severe skin fibrosis at the late stage-are chronic autoimmune diseases of connective tissue. The significant immune system dysfunction, distinguishing autoimmune-related fibrosis from mere skin fibrosis, should be a particular focus of treating autoimmune-related fibrosis. Recent research shows that innovative mesenchymal stem cell (MSC)-based therapy, with the capacities of immune regulation, inflammation suppression, oxidation inhibition, and fibrosis restraint, shows great promise in overcoming the disease.

MAIN BODY

This review of recent studies aims to summarize the therapeutic effect and theoretical mechanisms of MSC-based therapy in treating autoimmune-related fibrotic skin diseases, SSc and Scl-GVHD, providing novel insights and references for further clinical applications. It is noteworthy that the efficacy of MSCs is not reliant on their migration into the skin. Working on the immune system, MSCs can inhibit the chemotaxis and infiltration of immune cells to the skin by down-regulating the expression of skin chemokines and chemokine receptors and reducing the inflammatory and pro-fibrotic mediators. ​Furthermore, to reduce levels of oxidative stress, MSCs may improve vascular abnormalities, and enhance the antioxidant defenses through inducible nitric oxide synthase, thioredoxin 1, as well as other mediators. The oxidative stress environment does not weaken MSCs and may even strengthen certain functions. Regarding fibrosis, MSCs primarily target the transforming growth factor-β signaling pathway to inhibit fibroblast activation. Here, miRNAs may play a critical role in ECM remodeling. Clinical studies have demonstrated the safety of these approaches, though outcomes have varied, possibly owing to the heterogeneity of MSCs, the disorders themselves, and other factors. Nevertheless, the research clearly reveals the immense potential of MSCs in treating autoimmune-related fibrotic skin diseases.

CONCLUSION

The application of MSCs presents a promising approach for treating autoimmune-related fibrotic skin diseases: SSc and Scl-GVHD. Therapies involving MSCs and MSC extracellular vesicles have been found to operate through three primary mechanisms: rebalancing the immune and inflammatory disorders, resisting oxidant stress, and inhibiting overactivated fibrosis (including fibroblast activation and ECM remodeling). However, the effectiveness of these interventions requires further validation through extensive clinical investigations, particularly randomized control trials and phase III/IV clinical trials. Additionally, the hypothetical mechanism underlying these therapies could be elucidated through further research.

Exosomal miRNAs in autoimmune skin diseases

Exosomes, bilaterally phospholipid-coated small vesicles, are produced and released by nearly all cells, which comprise diverse biological macromolecules, including proteins, DNA, RNA, and others, that participate in the regulation of their biological functions. An increasing number of studies have revealed that the contents of exosomes, particularly microRNA(miRNA), play a significant role in the pathogenesis of various diseases, including autoimmune skin diseases. MiRNA is a class of single-stranded non-coding RNA molecules that possess approximately 22 nucleotides in length with the capability of binding to the untranslated as well as coding regions of target mRNA to regulate gene expression precisely at the post-transcriptional level. Various exosomal miRNAs have been found to be significantly expressed in some autoimmune skin diseases and involved in the pathogenesis of conditions via regulating the secretion of crucial pathogenic cytokines and the direction of immune cell differentiation. Thus, exosomal miRNAs might be promising biomarkers for monitoring disease progression, relapse and reflection to treatment based on their functions and changes. This review summarized the current studies on exosomal miRNAs in several common autoimmune skin diseases, aiming to dissect the underlying mechanism from a new perspective, seek novel biomarkers for disease monitoring and lay the foundation for developing innovative target therapy in the future.

Advancements in engineered exosomes for wound repair: current research and future perspectives

Wound healing is a complex and prolonged process that remains a significant challenge in clinical practice. Exosomes, a type of nanoscale extracellular vesicles naturally secreted by cells, are endowed with numerous advantageous attributes, including superior biocompatibility, minimal toxicity, and non-specific immunogenicity. These properties render them an exceptionally promising candidate for bioengineering applications. Recent advances have illustrated the potential of exosome therapy in promoting tissue repair. To further augment their therapeutic efficacy, the concept of engineered exosomes has been proposed. These are designed and functionally modifiable exosomes that have been tailored on the attributes of natural exosomes. This comprehensive review delineates various strategies for exosome engineering, placing specific emphasis on studies exploring the application of engineered exosomes for precision therapy in wound healing. Furthermore, this review sheds light on strategies for integrating exosomes with biomaterials to enhance delivery effectiveness. The insights presented herein provide novel perspectives and lay a robust foundation for forthcoming research in the realm of cutaneous wound repair therapies.

Progress in research on mesenchymal stem cells and their extracellular vesicles for treating fibrosis in systemic sclerosis

Systemic sclerosis (SSc) refers to an autoimmune disease characterized by immune dysfunction, vascular endothelial damage, and multi-organ fibrosis. Thus far, this disease is incurable, and its high mortality rate is significantly correlated with fibrotic events. Fibrosis has been confirmed as a difficult clinical treatment area that should be urgently treated in clinical medicine. Mesenchymal stem cells (MSCs) exhibit immunomodulatory, pro-angiogenic, and anti-fibrotic functions. MSCs-derived extracellular vesicles (EVs) have aroused rising interest as a cellular component that retains the functions of MSCs while circumventing the possible adverse effects of MSCs. Moreover, EVs have great potential in treating SSc. In this study, the current research progress on MSCs and their EVs for treating fibrosis in SSc was reviewed, with an aim to provide some reference for future MSCs and their EVs in treating SSc.

Advances in stem cell therapy for peritoneal fibrosis: from mechanisms to therapeutics

Peritoneal fibrosis (PF) is a pathophysiological condition caused by a variety of pathogenic factors. The most important features of PF are mesothelial-mesenchymal transition and accumulation of activated (myo-)fibroblasts, which hinder effective treatment; thus, it is critical to identify other practical approaches. Recently, stem cell (SC) therapy has been indicated to be a potential strategy for this disease. Increasing evidence suggests that many kinds of SCs alleviate PF mainly by differentiating into mesothelial cells; secreting cytokines and extracellular vesicles; or modulating immune cells, particularly macrophages. However, there are relatively few articles summarizing research in this direction. In this review, we summarize the risk factors for PF and discuss the therapeutic roles of SCs from different sources. In addition, we outline effective approaches and potential mechanisms of SC therapy for PF. We hope that our review of articles in this area will provide further inspiration for research on the use of SCs in PF treatment.

Exosomes from human adipose-derived mesenchymal stem cells attenuate localized scleroderma fibrosis by the let-7a-5p/TGF-βR1/Smad axis

BACKGROUND

Inflammation and fibrosis of the skin are characteristics of localized scleroderma (LS). Emerging evidence has demonstrated that exosomes from human adipose tissue-derived mesenchymal stem cells (ADSC-Exo) could alleviate skin fibrosis.

OBJECTIVE

The impact and potential mechanism of ADSC-Exo on LS fibrosis was examined.

METHODS

ADSC-Exo was isolated and identified. The effects of ADSC-Exo on the abilities of proliferation and migration of LS-derived fibroblasts (LSFs) were assessed by CCK-8 and scratch assays, respectively. qRT-PCR, western blot, and immunofluorescence were conducted to detect LSFs stimulated with ADSC-Exo, ADSC-ExoAnti-let-7a-5p, let-7a-5p mimic/TGF-βR1 shRNA virus, and negative controls. The impact of ADSC-Exo on C57BL/6j LS mice was evaluated by photographic morphology, hematoxylin-eosin (H&E), Masson's trichrome, and immunohistochemical staining.

RESULTS

The verified ADSC-Exo limited the proliferation and migration of LSFs and reduced the expression of COL1, COL3, α-SMA, TGF-βR1, and p-Smad2/ 3 in vitro and in vivo. TGF-βR1 knockdown and let-7a-5p mimic in LSFs reduced the expression of COL1, COL3, α-SMA, and p-Smad2/3. However, compared with the ADSC-ExoNC group, the dermal thickness was increased, collagen arrangement was disordered, and α-SMA and TGF-βR1 levels were increased after exposure to ADSC-ExoAnti-let-7a-5p.

CONCLUSIONS

In this study, it might show that ADSC-Exo may successfully prevent LSF bioactivity, collagen deposition, and myofibroblast trans-differentiation. Additionally, we confirmed that let-7a-5p in ADSC-Exo could directly target TGF-R1 to control the Smad pathway and reduce fibrosis in LSFs. Our work offered a brand-new therapeutic approach and clarified the unique mechanism for the clinical management of LS.

Mesenchymal Stem/Stromal Cell-Based Therapies in Systemic Rheumatic Disease: From Challenges to New Approaches for Overcoming Restrictions

Systemic rheumatic diseases, such as rheumatoid arthritis, systemic lupus erythematosus, and systemic sclerosis, are chronic autoimmune diseases affecting multiple organs and tissues. Despite recent advances in treatment, patients still experience significant morbidity and disability. Mesenchymal stem/stromal cell (MSC)-based therapy is promising for treating systemic rheumatic diseases due to the regenerative and immunomodulatory properties of MSCs. However, several challenges need to be overcome to use MSCs in clinical practice effectively. These challenges include MSC sourcing, characterization, standardization, safety, and efficacy issues. In this review, we provide an overview of the current state of MSC-based therapies in systemic rheumatic diseases, highlighting the challenges and limitations associated with their use. We also discuss emerging strategies and novel approaches that can help overcome the limitations. Finally, we provide insights into the future directions of MSC-based therapies for systemic rheumatic diseases and their potential clinical applications.

Potential angiogenic, immunomodulatory, and antifibrotic effects of mesenchymal stem cell-derived extracellular vesicles in systemic sclerosis

Systemic sclerosis (SSc) is an intricate systemic autoimmune disease with pathological features such as vascular injury, immune dysregulation, and extensive fibrosis of the skin and multiple organs. Treatment options are limited; however, recently, mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have been acknowledged in preclinical and clinical trials as being useful in treating autoimmune diseases and are likely superior to MSCs alone. Recent research has also shown that MSC-EVs can ameliorate SSc and the pathological changes in vasculopathy, immune dysfunction, and fibrosis. This review summarizes the therapeutic effects of MSC-EVs on SSc and the mechanisms that have been discovered to provide a theoretical basis for future studies on the role of MSC-EVs in treating SSc.

Research progress of exosomes as drug carriers in cancer and inflammation

Extracellular vesicles (EVs) could be produced by most cells and play an important role in disease development. As a subtype of EVs, exosomes exhibit suitable size, rich surface markers and diverse contents, making them more appealing as potential drug carriers. Compared with traditional synthetic nanoparticles, exosomes possess superior biocompatibility and much lower immunogenicity. This work reviewed the most up-to-date research progress of exosomes as carriers for nucleic acids, proteins and small molecule drugs for cancer and inflammation management. The drug loading strategies and potential cellular uptake behaviour of exosomes are highlighted, trying to provide reference for future exosome design and application.

Exosomes as biomarkers and therapeutic delivery for autoimmune diseases: Opportunities and challenges

Exosomes are spherical lipid bilayer vesicles composed of lipids, proteins and nucleic acids that deliver signaling molecules through a vesicular transport system to regulate the function and morphology of target cells, thereby involving in a variety of biological processes, such as cell apoptosis or proliferation, and cytokine production. In the past decades, there are emerging evidence that exosomes play pivotal roles in the pathological mechanisms of several autoimmune diseases (ADs), including rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), type 1 diabetes mellitus (T1DM), Sjogren's syndrome (SS), multiple sclerosis (MS), inflammatory bowel disease (IBD). systemic sclerosis (SSc), etc. Several publications have shown that exosomes are involved in the pathogenesis of ADs mainly through intercellular communication and by influencing the response of immune cells. The level of exosomes and the expression of nucleic acids can reflect the degree of disease progression and are excellent biomarkers for ADs. In addition, exosomes have the potential to be used as drug carriers thanks to their biocompatibility and stability. In this review, we briefly summarized the current researches regarding the biological functions of exosomes in ADs, and provided an insight into the potential of exosomes as biomarkers and therapeutic delivery for these diseases.

Application of extracellular vesicles derived from mesenchymal stem cells as potential therapeutic tools in autoimmune and rheumatic diseases

Mesenchymal stem cells (MSCs) have been proven to have superior potential to be used astherapeutic candidates in various disorders. Nevertheless, the clinical application of these cells have been restricted because of their tumorigenic properties. Increasing evidence has established that the valuable impacts of MSCs are mainly attributable to the paracrine factors including extracellular vesicles (EVs). EVs are nanosized double-layer phospholipid membrane vesicles contain various proteins, lipids and miRNAs which mediate cell-to-cell communications. Due to their inferior immunogenicity and tumorigenicity, as well as easier management, EVs have drawn attention as potential cell-free replacement therapy to MSCs. For that reason, herein, we reviewed the recent findings of researches on different MSC-EVs and their effectiveness in the treatment of several autoimmune and rheumatic diseases including multiple sclerosis, inflammatory bowel disease, rheumatoid arthritis, osteoarthritis, osteoporosis, and systemic lupus erythematosus as well as Sjogren's syndrome, systemic sclerosis and other autoimmune diseases.

The application of mesenchymal stromal cells (MSCs) and their derivative exosome in skin wound healing: a comprehensive review

Recently, mesenchymal stromal cells (MSCs) and also their exosome has become a game-changing tool in the context of tissue engineering and regenerative medicine. MSCs due to their competencies to establish skin cells, such as fibroblast and keratinocyte, and also their unique attribute to suppress inflammation in wound site has attracted increasing attention among scholars. In addition, MSC's other capabilities to induce angiogenesis as a result of secretion of pro-angiogenic factors accompanied with marked anti-fibrotic activities, which mainly mediated by the releases matrix metalloproteinase (MMPs), make them a rational and effective strategy to accelerate wound healing with a small scar. Since the chief healing properties of the MSCs depend on their paracrine effects, it appears that MSCs-derived exosomes also can be an alternative option to support wound healing and skin regeneration as an innovative cell-free approach. Such exosomes convey functional cargos (e.g., growth factor, cytokine, miRNA, etc.) from MSCs to target cells, thereby affecting the recipient skin cells' biological events, such as migration, proliferation, and also secretion of ECM components (e.g., collagen). The main superiorities of exosome therapy over parental MSCs are the diminished risk of tumor formation and also lower immunogenicity. Herein, we deliver an overview of recent in vivo reports rendering the therapeutic benefits of the MSCs-based therapies to ease skin wound healing, and so improving quality of life among patients suffering from such conditions.