Human umbilical cord mesenchymal stem cells-derived exosomal microRNA-17-3p ameliorates inflammatory reaction and antioxidant injury of mice with diabetic retinopathy via targeting STAT1

Egg exosome miR-145-5p decreases mitochondrial ROS to protect chicken embryo hepatocytes against apoptosis through targeting MAPK10

BACKGROUND

Higher embryonic mortality, especially in aged breeding hens, is associated with insufficient hepatic functionality in maintaining redox homeostasis. Our previous study demonstrated that egg exosome-derived miRNAs may play a key role in modulating embryonic oxidation-reduction process, whereas the exact function and mechanism were still poorly understood. The present study aimed to investigate the roles of egg exosome miRNAs in maintaining dynamic equilibrium of free radicals and peroxide agents in embryonic liver, as well as demonstrate the specific mechanism using oxidative stress-challenged hepatocytes.

RESULTS

Compared to 36-week-old breeding hens, decreased hatchability and increased embryonic mortality were observed in 65-week-old breeding hens. Meanwhile, the older group showed the increased MDA levels and decreased SOD and GSH-Px activities in embryonic liver, muscle and serum. Embryonic mortality was significantly positively correlated with MDA level and negatively correlated with GSH-Px activity in embryonic liver. In addition, 363 differentially expressed genes (DEGs) were identified in embryonic liver, 13 differentially expressed miRNAs (DE-miRNAs) were identified in egg exosomes. These DEGs and DE-miRNAs were involved in oxidoreductase activity, glutathione metabolic process, MAPK signaling pathway, apoptosis and autophagy. miRNA-mRNA network analysis further found that DEGs targeted by DE-miRNAs were mainly enriched in programmed cell death, such as apoptosis and autophagy. Wherein, MAPK10 with highest MCC and AUC values was significantly related to GSH-Px activity and MDA level, and served as the target gene of miR-145-5p based on dual luciferase reporter experiment and correlation analysis. Bioinformatics analysis found that miR-145-5p/MAPK10 axis might alleviate peroxide generation and apoptosis. In primary hepatocytes of chick embryos, miR-145-5p transfection significantly reversed H2O2-induced mitochondrial ROS increase, MAPK10, BAX and CASP3 overexpression and excessive apoptosis.

CONCLUSION

Exosome miR-145-5p in eggs could target MAPK10 and decrease mitochondrial ROS, attenuating oxidative damage and apoptosis in hepatocytes of chick embryos. These findings may provide new theoretical basis for the improvement of maternal physiological status to maintain embryonic redox homeostasis by nutritional or genetic modifications.

Rekindling Vision: Innovative Strategies for Treating Retinal Degeneration

Retinal degeneration, characterized by the progressive loss of photoreceptors, retinal pigment epithelium cells, and/or ganglion cells, is a leading cause of vision impairment. These diseases are generally classified as inherited (e.g., retinitis pigmentosa, Stargardt disease) or acquired (e.g., age-related macular degeneration, diabetic retinopathy, glaucoma) ocular disorders that can lead to blindness. Available treatment options focus on managing symptoms or slowing disease progression and do not address the underlying causes of these diseases. However, recent advancements in regenerative medicine offer alternative solutions for repairing or protecting degenerated retinal tissue. Stem and progenitor cell therapies have shown great potential to differentiate into various retinal cell types and can be combined with gene editing, extracellular vesicles and exosomes, and bioactive molecules to modulate degenerative cellular pathways. Additionally, gene therapy and neuroprotective molecules play a crucial role in enhancing the efficacy of regenerative approaches. These innovative strategies hold the potential to halt the progression of retinal degenerative disorders, repair or replace damaged cells, and improve visual function, ultimately leading to a better quality of life for those affected.

Extracellular Vesicles and Pregnancy-Related Hypertensive Disorders: A Descriptive Review on the Possible Implications "From Bench to Bedside"

Pregnancy involves extracellular vesicles (EVs) through mechanisms that are poorly understood to date. Furthermore, it is not surprising that EVs may also be involved in the pathophysiology of pre-eclampsia (PE) and gestational hypertension, two clinical conditions with high morbidity and mortality, given their capacity to mediate intracellular communications and regulate inflammation and angiogenesis. We searched major online scientific search engines (PubMed, Google Scholar, Scopus, WES, Embase, etc.) using the terms "Preeclampsia", "Pregnancy", "Hypertension", "Pregnancy-related hypertension", "Extracellular vesicles", "Biomarkers", "Gestation" AND "Obstetrics". Finding potential early biomarkers of risk or illness progression would be essential for the optimum care of expectant mothers with the aforementioned conditions. Nevertheless, none of the various screening assays that have been discovered recently have shown high predictive values. The analysis of EVs in the peripheral blood starting from the first trimester of pregnancy may hold great promise for the possible correlation with gestational hypertension problems and represent a marker of the early stages of the disease. EVs use may be a novel therapeutic approach for the management of various illnesses, as well. In order to define EVs' function in the physiopathology of pregnancy-associated hypertension and PE, as well as their potential as early biomarkers and therapeutic tools, we have compiled the most recent data in this review.

Mesenchymal stem cells and mesenchymal stem cell-derived exosomes: a promising strategy for treating retinal degenerative diseases

Mesenchymal stem cells (MSCs) have emerged as a promising therapeutic strategy in regenerative medicine, demonstrating significant potential for clinical applications. Evidence suggests that MSCs not only exhibit multipotent differentiation potential but also exert critical therapeutic effects in retinal degenerative diseases via robust paracrine mechanisms. MSCs protect retinal cells from degenerative damage by modulating inflammation, inhibiting apoptosis, alleviating oxidative stress, and suppressing cell death pathways. Furthermore, MSCs contribute to retinal structural and functional stability by facilitating vascular remodeling and donating mitochondria to retinal cells. Of particular interest, MSC-derived exosomes have gained widespread attention as a compelling cell-free therapy. Owing to their potent anti-inflammatory, anti-apoptotic, and vascular-stabilizing properties, exosomes show significant promise for the treatment of retinal degenerative diseases.

Exosome's Implications in Age-Related Macular Degeneration

PURPOSE

This study aims to conduct a mini review of published literature concerning the role of exosomes in the field of ophthalmology, with a specific focus on Age-Related Macular Degeneration (AMD).

METHODS

In this study, a comprehensive search was conducted using PubMed and Google Scholar to identify relevant publications. Additionally, trials submitted to clinicaltrials.gov were reviewed to identify further relevant articles. The selected studies specifically focused on the ocular implications of exosomes in Age-Related Macular Degeneration.

RESULTS

Exosomes, small extracellular vesicles measuring less than 200 nm, play a crucial role in cell signaling and are involved in various physiological and pathological processes. Recent research has focused on utilizing exosomes for disease detection and treatment. Studies have investigated the ocular implications of exosomes, particularly in AMD. Exosomes found in aqueous fluid and blood have been examined as potential markers for AMD and as indicators of treatment response. Additionally, research in animal models has indicated the potential of exosomes in preventing AMD, as well as their promise for targeted and efficient drug delivery. This mini review primarily emphasizes the clinical aspects of publications related to AMD, rather than focusing solely on basic science.

CONCLUSIONS

Exosomes have a great potential for understanding Age-related Macular Degeneration and effective and targeted treatment for retinal diseases.

Future Directions in Diabetic Retinopathy Treatment: Stem Cell Therapy, Nanotechnology, and PPARα Modulation

This narrative review focuses on innovative treatment approaches to diabetic retinopathy to meet the urgent demand for advancements in managing both the early and late stages of the disease. Recent studies highlight the potential of adipose stem cells and their secreted factors in mitigating the retinal complications of diabetes, with promising results in improving visual acuity and reducing inflammation and angiogenesis in diabetic retinopathy. However, caution is warranted regarding the safety and long-term therapeutic effects of adipose stem cells transplantation. Bone marrow mesenchymal stem cells can also mitigate retinal damage in diabetic retinopathy. Studies demonstrate that bone marrow mesenchymal stem cells-derived exosomes can suppress the Wnt/β-catenin pathway, reducing oxidative stress, inflammation, and angiogenesis in the diabetic retina, offering promise for future diabetic retinopathy treatments. Nanotechnology has the ability to precisely target the retina and minimize systemic side effects. Nanoparticles and nanocarriers offer improved bioavailability, sustained release of therapeutics, and potential for synergistic effects. They can be a new way of effective treatment and prevention of diabetic retinopathy. Activation and modulation of PPARα as a means for diabetic retinopathy treatment has been widely investigated in recent years and demonstrated promising effects in clinical trials. PPARα activation turned out to be a promising therapeutic method for treating dyslipidemia, inflammation, and insulin sensitivity. The combination of PPARα modulators with small molecules offers an interesting perspective for retinal diseases' therapy.

Therapeutic Efficacy and Promise of Human Umbilical Cord Mesenchymal Stem Cell-Derived Extracellular Vesicles in Aging and Age-Related Disorders

The global issue of aging populations has become increasingly prominent, thus the research and development for anti-aging therapies to assure longevity as well as to ameliorate age-related complications is put high on the agenda. The young humoral milieu has been substantiated to impart youthful characteristics to aged cells or organs. Extracellular vesicles (EVs) are a heterogeneous group of cell-derived membrane-limited structures that serve as couriers of proteins and genetic material to regulate intercellular communication. Of note, EVs appeared to be an indispensable component of young blood in prolonging lifespans, and circulating EVs have been indicated to mediate the beneficial effect of a young milieu on aging. Human umbilical cord mesenchymal stem cell-derived EVs (HUCMSC-EVs), isolated from the youngest adult stem cell source, are speculated to reproduce the function of circulating EVs in young blood and partially revitalize numerous organs in old animals. Robust evidence has suggested HUCMSC-EVs as muti-target therapeutic agents in combating aging and alleviating age-related degenerative disorders. Here, we provide a comprehensive overview of the anti-aging effects of HUCMSC-EVs in brain, heart, vasculature, kidney, muscle, bone, and other organs. Furthermore, we critically discuss the current investigation on engineering strategies of HUCMSC-EVs, intending to unveil their full potential in the field of anti-aging research.

The STAT1-SLC31A1 axis: Potential regulation of cuproptosis in diabetic retinopathy

BACKGROUND

By identifying molecular biological markers linked to cuproptosis in diabetic retinopathy (DR), new pathobiological pathways and more accessible diagnostic markers can be developed.

METHODS

The datasets related to DR were acquired from the Gene Expression Omnibus database, while genes associated with cuproptosis were sourced from previously published compilations. Consensus clustering was conducted to delineate distinct DR subclasses. Feature genes were identified utilizing weighted correlation network analysis (WGCNA). Additionally, two machine-learning algorithms were employed to refine the selection of feature genes. Finally, we conducted preliminary validation experiments to ascertain the involvement of cuproptosis in DR development and the transcriptional regulation of critical genes using both the streptozotocin-induced diabetic mouse model and the high glucose-induced BV2 model.

RESULTS

In the STZ-induced diabetic mouse retinas, a decrease in the expression of cuproptosis signature proteins (FDX1, DLAT, and NDUFS8) suggested the occurrence of cuproptosis in DR. Subsequently, the expression of eight cuproptosis differential genes was validated through the STZ-induced diabetes and oxygen-induced retinopathy (OIR) models, with the key gene SLC31A1 showing upregulation in both models and dataset species. Further analyses, including weighted gene co-expression network analysis, GSVA, and immune infiltration analysis, indicated a close correlation between cuproptosis and microglia function. Additionally, validation in an in vitro model of microglia indicated the occurrence of cuproptosis in microglia under high glucose conditions, alongside abnormal expression of STAT1 with SLC31A1.

CONCLUSION

Our findings suggest that STAT1/SLC31A1 may pave the way for a deeper comprehension of the mechanistic basis of DR and offer potential therapeutic avenues.

Stem Cell-Derived Exosomes: Natural Intercellular Messengers with Versatile Mechanisms for the Treatment of Diabetic Retinopathy

Diabetic retinopathy is one of the complications of diabetes mellitus that occurs in the early stages. It is a disease that has a serious impact, and may lead to blindness when the disease progresses to advanced stages. Currently, treatments for diabetic retinopathy are mainly limited to its advanced stages of the disease, being restricted to a single therapeutic mechanism. Stem cells hold the promise of regenerative therapy and have the potential to comprehensively improve diabetic retinopathy. However, direct stem cell therapy carries some risk of carcinogenesis. Exosomes secreted by stem cells have shown a similar overall improvement in disease as stem cells. Exosomes can carry a number of biologically active materials from donor cells to recipient cells or distant organs, regulating intercellular signaling. Exosomes have shown remarkable efficacy in alleviating oxidative stress, inhibiting inflammatory responses, suppressing angiogenesis, reducing apoptosis and protecting neural tissues. Currently, the experimental literature using stem cell exosomes in the treatment of diabetic retinopathy tends to converge on the above experimental results. With this in mind, we have chosen to explore exosomes in depth from a subtle molecular perspective. We will elaborate on this perspective in this paper and propose to advocate exosome therapy as one promising approach for the treatment of diabetic retinopathy to ameliorate the lesions through multiple mechanisms.

Mesenchymal Stem Cell-Derived Exosomes Attenuate Hepatic Steatosis and Insulin Resistance in Diet-Induced Obese Mice by Activating the FGF21-Adiponectin Axis

Exosomes derived from mesenchymal stem cells have shown promise in treating metabolic disorders, yet their specific mechanisms remain largely unclear. This study investigates the protective effects of exosomes from human umbilical cord Wharton's jelly mesenchymal stem cells (hWJMSCs) against adiposity and insulin resistance in high-fat diet (HFD)-induced obese mice. HFD-fed mice treated with hWJMSC-derived exosomes demonstrated improved gut barrier integrity, which restored immune balance in the liver and adipose tissues by reducing macrophage infiltration and pro-inflammatory cytokine expression. Furthermore, these exosomes normalized lipid metabolism including lipid oxidation and lipogenesis, which alleviate lipotoxicity-induced endoplasmic reticulum (ER) stress, thereby decreasing fat accumulation and chronic tissue inflammation in hepatic and adipose tissues. Notably, hWJMSC-derived exosomes also promoted browning and thermogenic capacity of adipose tissues, which was linked to reduced fibroblast growth factor 21 (FGF21) resistance and increased adiponectin production. This process activated the AMPK-SIRT1-PGC-1α pathway, highlighting the role of the FGF21-adiponectin axis. Our findings elucidate the molecular mechanisms through which hWJMSC-derived exosomes counteract HFD-induced metabolic dysfunctions, supporting their potential as therapeutic agents for metabolic disorders.

Advances in Extracellular-Vesicles-Based Diagnostic and Therapeutic Approaches for Ocular Diseases

Extracellular vesicles (EVs) are nanoscale membrane vesicles of various sizes that can be secreted by most cells. EVs contain a diverse array of cargo, including RNAs, lipids, proteins, and other molecules with functions of intercellular communication, immune modulation, and regulation of physiological and pathological processes. The biofluids in the eye, including tears, aqueous humor, and vitreous humor, are important sources for EV-based diagnosis of ocular disease. Because the molecular cargos may reflect the biology of their parental cells, EVs in these biofluids, as well as in the blood, have been recognized as promising candidates as biomarkers for early diagnosis of ocular disease. Moreover, EVs have also been used as therapeutics and targeted drug delivery nanocarriers in many ocular disorders because of their low immunogenicity and superior biocompatibility in nature. In this review, we provide an overview of the recent advances in the field of EV-based studies on the diagnosis and therapeutics of ocular disease. We summarized the origins of EVs applied in ocular disease, assessed different methods for EV isolation from ocular biofluid samples, highlighted bioengineering strategies of EVs as drug delivery systems, introduced the latest applications in the diagnosis and treatment of ocular disease, and presented their potential in the current clinical trials. Finally, we briefly discussed the challenges of EV-based studies in ocular disease and some issues of concern for better focusing on clinical translational studies of EVs in the future.

Exosomes and Macrophages: Bidirectional Mutual Regulation in the Treatment of Diabetic Complications

Purpose

The bidirectional regulation of macrophages and exosomes provides a meaningful research direction for the treatment of complications arising from both type 1 and type 2 diabetes mellitus. However, there is currently no comprehensive evaluation of the bidirectional regulatory role of macrophages and exosomes in diabetic complications. In this review, we aim to provide the detailed process of the bidirectional regulation mechanism of macrophages and exosomes, and how macrophage-associated exosomes use this mechanism to make it better applied to clinical practice through biotechnology.

Methods

Therefore, we summarized the bidirectional regulation mechanism of macrophages and exosomes and the application based on the bidirectional regulation mechanism from two aspects of inflammation and insulin resistance.

Results

As key regulators of the immune system, macrophages are crucial in the progression of diabetic complications due to their significant impact on the regulation of cellular metabolism, inflammation, and insulin sensitivity. Furthermore, exosomes, as innovative mediators of intercellular communication, transport miRNAs, proteins, and various bioactive molecules, influencing the occurrence and progression of diabetic complications through the regulation of inflammation and insulin resistance. The bidirectional regulation between macrophages and exosomes provides a promising pathway for the treatment of diabetic complications aimed at regulating the immune response and improving insulin sensitivity.

Conclusions

Understanding the complexity of the interaction between macrophages and exosomes can advance the treatment of diabetic complications and drug development, and bringing more innovative and effective treatment strategies for diabetic complications.

The role of exosome derived miRNAs in inter-cell crosstalk among insulin-related organs in type 2 diabetes mellitus

Exosomes are small extracellular vesicles secreted by almost all cell types, and carry diverse cargo including RNA, and other substances. Recent studies have focused exosomal microRNAs (miRNAs) on various human diseases, including type 2 diabetes mellitus (T2DM) and metabolic syndrome (METS) which accompany the occurrence of insulin resistance. The regulation of insulin signaling has connected with some miRNA expression which play a significant regulatory character in insulin targeted cells or organs, such as fat, muscle, and liver. The miRNAs carried by exosomes, through the circulation in the body fluids, mediate all kinds of physiological and pathological process involved in the human body. Studies have found that exosome derived miRNAs are abnormally expressed and cross-talked with insulin targeted cells or organs to affect insulin pathways. Further investigations of the mechanisms of exosomal miRNAs in T2DM will be valuable for the diagnostic biomarkers and therapeutic targets of T2DM. This review will summarize the molecular mechanism of action of the miRNAs carried by exosomes which are secreted from insulin signaling related cells, and elucidate the pathogenesis of insulin resistance to provide a new strategy for the potential diagnostic biomarkers and therapeutic targets for the type 2 diabetes.

Mechanistic and therapeutic perspectives of non-coding RNA-modulated apoptotic signaling in diabetic retinopathy

Diabetic retinopathy (DR), a significant and vision-endangering complication associated with diabetes mellitus, constitutes a substantial portion of acquired instances of preventable blindness. The progression of DR appears to prominently feature the loss of retinal cells, encompassing neural retinal cells, pericytes, and endothelial cells. Therefore, mitigating the apoptosis of retinal cells in DR could potentially enhance the therapeutic approach for managing the condition by suppressing retinal vascular leakage. Recent advancements have highlighted the crucial regulatory roles played by non-coding RNAs (ncRNAs) in diverse biological processes. Recent advancements have highlighted that non-coding RNAs (ncRNAs), including microRNAs (miRNAs), circular RNAs (circRNAs), and long non-coding RNAs (lncRNAs), act as central regulators in a wide array of biogenesis and biological functions, exerting control over gene expression associated with histogenesis and cellular differentiation within ocular tissues. Abnormal expression and activity of ncRNAs has been linked to the regulation of diverse cellular functions such as apoptosis, and proliferation. This implies a potential involvement of ncRNAs in the development of DR. Notably, ncRNAs and apoptosis exhibit reciprocal regulatory interactions, jointly influencing the destiny of retinal cells. Consequently, a thorough investigation into the complex relationship between apoptosis and ncRNAs is crucial for developing effective therapeutic and preventative strategies for DR. This review provides a fundamental comprehension of the apoptotic signaling pathways associated with DR. It then delves into the mutual relationship between apoptosis and ncRNAs in the context of DR pathogenesis. This study advances our understanding of the pathophysiology of DR and paves the way for the development of novel therapeutic strategies.

Research progress and prospects of benefit-risk assessment methods for umbilical cord mesenchymal stem cell transplantation in the clinical treatment of spinal cord injury

Over the past decade, we have witnessed the development of cell transplantation as a new strategy for repairing spinal cord injury (SCI). However, due to the complexity of the central nervous system (CNS), achieving successful clinical translation remains a significant challenge. Human umbilical cord mesenchymal stem cells (hUMSCs) possess distinct advantages, such as easy collection, lack of ethical concerns, high self-renewal ability, multilineage differentiation potential, and immunomodulatory properties. hUMSCs are promising for regenerating the injured spinal cord to a significant extent. At the same time, for advancing SCI treatment, the appropriate benefit and risk evaluation methods play a pivotal role in determining the clinical applicability of treatment plans. Hence, this study discusses the advantages and risks of hUMSCs in SCI treatment across four dimensions-comprehensive evaluation of motor and sensory function, imaging, electrophysiology, and autonomic nervous system (ANS) function-aiming to improve the rationality of relevant clinical research and the feasibility of clinical translation.

MSC-derived small extracellular vesicles mitigate diabetic retinopathy by stabilizing Nrf2 through miR-143-3p-mediated inhibition of neddylation

Diabetic retinopathy (DR) is a highly hazardous and widespread complication of diabetes mellitus (DM). The accumulated reactive oxygen species (ROS) play a central role in DR development. The aim of this research was to examine the impact and mechanisms of mesenchymal stem cell (MSC)-derived small extracellular vesicles (sEV) on regulating ROS and retinal damage in DR. Intravitreal injection of sEV inhibited Cullin3 neddylation, stabilized Nrf2, decreased ROS, reduced retinal inflammation, suppressed Müller gliosis, and mitigated DR. Based on MSC-sEV miRNA sequencing, bioinformatics software, and dual-luciferase reporter assay, miR-143-3p was identified to be the key effector for MSC-sEV's role in regulating neural precursor cell expressed developmentally down-regulated 8 (NEDD8)-mediated neddylation. sEV were able to be internalized by Müller cells. Compared to advanced glycation end-products (AGEs)-induced Müller cells, sEV coculture decreased Cullin3 neddylation, activated Nrf2 signal pathway to combat ROS-induced inflammation. The barrier function of endothelial cells was impaired when endothelial cells were treated with the supernatant of AGEs-induced Müller cells, but was restored when treated with supernatant of AGEs-induced Müller cells cocultured with sEV. The protective effect of sEV was, however, compromised when miR-143-3p was inhibited in sEV. Moreover, the protective efficacy of sEV was diminished when NEDD8 was overexpressed in Müller cells. These findings showed MSC-sEV delivered miR-143-3p to inhibit Cullin3 neddylation, stabilizing Nrf2 to counteract ROS-induced inflammation and reducing vascular leakage. Our findings suggest that MSC-sEV may be a potential nanotherapeutic agent for DR, and that Cullin3 neddylation could be a new target for DR therapy.

Exosomes derived from mesenchymal stem cells in diabetes and diabetic complications

Diabetes, a group of metabolic disorders, constitutes an important global health problem. Diabetes and its complications place a heavy financial strain on both patients and the global healthcare establishment. The lack of effective treatments contributes to this pessimistic situation and negative outlook. Exosomes released from mesenchymal stromal cells (MSCs) have emerged as the most likely new breakthrough and advancement in treating of diabetes and diabetes-associated complication due to its capacity of intercellular communication, modulating the local microenvironment, and regulating cellular processes. In the present review, we briefly outlined the properties of MSCs-derived exosomes, provided a thorough summary of their biological functions and potential uses in diabetes and its related complications.

Investigating the expression level of miR-17-3p, miR-101-3p, miR-335-3p, and miR-296-3p in the peripheral blood of patients with acute myocardial infarction

The role of inflammation has been proven in acute myocardial infarction (AMI) pathogenesis. Due to the effect of NLRP3 gene expression in the inflammation process of MI, we aimed to explore the expression changes and diagnostic power of four inflammation-related miRNAs including miR-17-3p, miR-101-3p, miR-335-3p, miR-296-3p and their potential target, NLRP3, in ST-segment elevation myocardial infarction (STEMI), and non-STEMI (NSTEMI) patients as two major classes of AMI. The expression level of these genes were evaluated in 300 participants equally divided into three groups of STEMI, NSTEMI, and control using quantitative real-time PCR. The expression level of NLRP3 was upregulated in STEMI and NSTEMI patients compared to control subjects. Besides, the expression levels of miR-17-3p, miR-101-3p, and miR-296-3p were significantly downregulated in STEMI and NSTEMI patients compared to controls. The increased expression of NLRP3 had a very strong inverse correlation with miR-17-3p in patients with STEMI and with miR-101-3p in the STEMI and NSTEMI patients. ROC curve analysis showed that the expression level of miR-17-3p had the highest diagnostic power for discrimination between STEMI patients and controls. Remarkably, the combination of all markers resulted in a higher AUC. In summary, there is a significant association between the expression levels of miR-17-3p, miR-101-3p, miR-335-3p, miR-296-3p, and NLRP3 and the incidence of AMI. Although the miR-17-3p expression level has the highest diagnostic power to distinguish between STEMI patients and control subjects, the combination of these miRNAs and NLRP3 could serve as a novel potential diagnostic biomarker of STEMI.

Non-coding RNAs and exosomal non-coding RNAs in diabetic retinopathy: A narrative review

Diabetic retinopathy (DR) is a devastating complication of diabetes, having extensive and resilient effects on those who suffer from it. As yet, the underlying cell mechanisms of this microvascular disorder are largely unclear. Recently, growing evidence suggests that epigenetic mechanisms can be responsible for gene deregulation leading to the alteration of key processes in the development and progression of DR, in addition to the widely recognized pathological mechanisms. It is noteworthy that seemingly unending epigenetic modifications, caused by a prolonged period of hyperglycemia, may be a prominent factor that leads to metabolic memory, and brings epigenetic entities such as non-coding RNA into the equation. Consequently, further investigation is necessary to truly understand this mechanism. Exosomes are responsible for carrying signals from cells close to the vasculature that are participating in abnormal signal transduction to faraway organs and cells by sailing through the bloodstream. These signs indicate metabolic disorders. With the aid of their encased structure, they can store diverse signaling molecules, which then can be dispersed into the blood, urine, and tears. Herein, we summarized various non-coding RNAs (ncRNAs) that are related to DR pathogenesis. Moreover, we highlighted the role of exosomal ncRNAs in this disease.

Small Extracellular Vesicles and Oxidative Pathophysiological Mechanisms in Retinal Degenerative Diseases

This review focuses on the role of small extracellular vesicles in the pathophysiological mechanisms of retinal degenerative diseases. Many of these mechanisms are related to or modulated by the oxidative burden of retinal cells. It has been recently demonstrated that cellular communication in the retina involves extracellular vesicles and that their rate of release and cargo features might be affected by the cellular environment, and in some instances, they might also be mediated by autophagy. The fate of these vesicles is diverse: they could end up in circulation being used as markers, or target neighbor cells modulating gene and protein expression, or eventually, in angiogenesis. Neovascularization in the retina promotes vision loss in diseases such as diabetic retinopathy and age-related macular degeneration. The importance of micro RNAs, either as small extracellular vesicles' cargo or free circulating, in the regulation of retinal angiogenesis is also discussed.

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.

Stem cells as a regenerative medicine approach in treatment of microvascular diabetic complications

Diabetes mellitus (DM) is a chronic metabolic disorder characterized by high blood glucose and is associated with high morbidity and mortality among the diabetic population. Uncontrolled chronic hyperglycaemia causes increased formation and accumulation of different oxidative and nitrosative stress markers, resulting in microvascular and macrovascular complications, which might seriously affect the quality of a patient's life. Conventional treatment strategies are confined to controlling blood glucose by regulating the insulin level and are not involved in attenuating the life-threatening complications of diabetes mellitus. Thus, there is an unmet need to develop a viable treatment strategy that could target the multi-etiological factors involved in the pathogenesis of diabetic complications. Stem cell therapy, a regenerative medicine approach, has been investigated in diabetic complications owing to their unique characteristic features of self-renewal, multilineage differentiation and regeneration potential. The present review is focused on potential therapeutic applications of stem cells in the treatment of microvascular diabetic complications such as nephropathy, retinopathy, and polyneuropathy.

Oxidative Stress and Its Regulation in Diabetic Retinopathy

Diabetic retinopathy is the retinal disease associated with hyperglycemia in patients who suffer from type 1 or type 2 diabetes. It includes maculopathy, involving the central retina and characterized by ischemia and/or edema, and peripheral retinopathy that progresses to a proliferative stage with neovascularization. Approximately 10% of the global population is estimated to suffer from diabetes, and around one in 5 of these individuals have diabetic retinopathy. One of the major effects of hyperglycemia is oxidative stress, the pathological state in which elevated production of reactive oxygen species damages tissues, cells, and macromolecules. The retina is relatively prone to oxidative stress due to its high metabolic activity. This review provides a summary of the role of oxidative stress in diabetic retinopathy, including a description of the retinal cell players and the molecular mechanisms. It discusses pathological processes, including the formation and effects of advanced glycation end-products, the impact of metabolic memory, and involvements of non-coding RNA. The opportunities for the therapeutic blockade of oxidative stress in diabetic retinopathy are also considered.

Exosomal non-coding RNAs in angiogenesis: Functions, mechanisms and potential clinical applications

Exosomes are extracellular vesicles that can be produced by most cells. Exosomes act as important intermediaries in intercellular communication, and participate in a variety of biological activities between cells. Non-coding RNAs (ncRNAs) usually refer to RNAs that do not encode proteins. Although ncRNAs have no protein-coding capacity, they are able to regulate gene expression at multiple levels. Angiogenesis is the formation of new blood vessels from pre-existing vessels, which is an important physiological process. However, abnormal angiogenesis could induce many diseases such as atherosclerosis, diabetic retinopathy and cancer. Many studies have shown that ncRNAs can stably exist in exosomes and play a wide range of physiological and pathological roles including regulation of angiogenesis. In brief, some specific ncRNAs can be enriched in exosomes secreted by cells and absorbed by recipient cells through the exosome pathway, thus activating relevant signaling pathways in target cells and playing a role in regulating angiogenesis. In this review, we describe the physiological and pathological functions of exosomal ncRNAs in angiogenesis, summarize their role in angiogenesis-related diseases, and illustrate potential clinical applications like novel drug therapy strategies and diagnostic markers in exosome research as inspiration for future investigations.

Pathological role of inflammation in ocular disease progress and its targeting by mesenchymal stem cells (MSCs) and their exosome; current status and prospect

Because of their unique capacity for differentiation to a diversity of cell lineages and immunosuppressive properties, mesenchymal stem cells (MSC) are being looked at as a potential new treatment option in ophthalmology. The MSCs derived from all tissue sources possess immunomodulatory attributes through cell-to-cell contact and releasing a myriad of immunomodulatory factors (IL-10, TGF-β, growth-related oncogene (GRO), indoleamine 2,3 dioxygenase (IDO), nitric oxide (NO), interleukin 1 receptor antagonist (IL-1Ra), prostaglandin E2 (PGE2)). Such mediators, in turn, alter both the phenotype and action of all immune cells that serve a pathogenic role in the progression of inflammation in eye diseases. Exosomes from MSCs, as natural nano-particles, contain the majority of the bioactive components of parental MSCs and can easily by-pass all biological barriers to reach the target epithelial and immune cells in the eye without interfering with nearby parenchymal cells, thus having no serious side effects. We outlined the most recent research on the molecular mechanisms underlying the therapeutic benefits of MSC and MSC-exosome in the treatment of inflammatory eye diseases in the current article.

miRNA-Guided Regulation of Mesenchymal Stem Cells Derived from the Umbilical Cord: Paving the Way for Stem-Cell Based Regeneration and Therapy

The human body is an abundant source of multipotent cells primed with unique properties that can be exploited in a multitude of applications and interventions. Mesenchymal stem cells (MSCs) represent a heterogenous population of undifferentiated cells programmed to self-renew and, depending on their origin, differentiate into distinct lineages. Alongside their proven ability to transmigrate toward inflammation sites, the secretion of various factors that participate in tissue regeneration and their immunoregulatory function render MSCs attractive candidates for use in the cytotherapy of a wide spectrum of diseases and conditions, as well as in different aspects of regenerative medicine. In particular, MSCs that can be found in fetal, perinatal, or neonatal tissues possess additional capabilities, including predominant proliferation potential, increased responsiveness to environmental stimuli, and hypoimmunogenicity. Since microRNA (miRNA)-guided gene regulation governs multiple cellular functions, miRNAs are increasingly being studied in the context of driving the differentiation process of MSCs. In the present review, we explore the mechanisms of miRNA-directed differentiation of MSCs, with a special focus on umbilical cord-derived mesenchymal stem cells (UCMSCs), and we identify the most relevant miRNAs and miRNA sets and signatures. Overall, we discuss the potent exploitations of miRNA-driven multi-lineage differentiation and regulation of UCMSCs in regenerative and therapeutic protocols against a range of diseases and/or injuries that will achieve a meaningful clinical impact through maximizing treatment success rates, while lacking severe adverse events.

The molecular mechanism of human stem cell-derived extracellular vesicles in retinal repair and regeneration

Extracellular vesicles (EVs), including microvesicles (MVs) and exosomes, play a critical role in metabolic regulation and intracellular communication. Stem cell-derived EVs are considered to have the potential for regeneration, like stem cells, while simultaneously avoiding the risk of immune rejection or tumour formation. The therapeutic effect of stem cell-derived EVs has been proven in many diseases. However, the molecular mechanism of stem cell-derived EVs in retinal repair and regeneration has not been fully clarified. In this review, we described the biological characteristics of stem cell-derived EVs, summarized the current research on stem cell-derived EV treatment in retinal repair and regeneration, and discussed the potential and challenges of stem cell-derived EVs in translational medicine.

Mesenchymal Stem Cell-Derived Exosomes in Ophthalmology: A Comprehensive Review

Over the past decade, the field of mesenchymal stem cell (MSC) therapy has exhibited rapid growth. Due to their regenerative, reparatory, and immunomodulatory capacities, MSCs have been widely investigated as therapeutic agents in the cell-based treatment of chronic ophthalmic pathologies. However, the applicability of MSC-based therapy is limited by suboptimal biocompatibility, penetration, and delivery to the target ocular tissues. An emerging body of research has elucidated the role of exosomes in the biological functions of MSCs, and that MSC-derived extracellular vesicles (EVs) possess anti-inflammatory, anti-apoptotic, tissue repairing, neuroprotective, and immunomodulatory properties similar to MSCs. The recent advances in MSCs-derived exosomes can serve as solutions to the challenges faced by MSCs-therapy. Due to their nano-dimensions, MSC-derived exosomes can rapidly penetrate biological barriers and reach immune-privileged organs, allowing for efficient delivery of therapeutic factors such as trophic and immunomodulatory agents to ocular tissues that are typically challenging to target by conventional therapy and MSCs transplantation. In addition, the use of EVs minimizes the risks associated with mesenchymal stem cell transplantation. In this literature review, we focus on the studies published between 2017 and 2022, highlighting the characteristics of EVs derived from MSCs and their biological functions in treating anterior and posterior segment ocular diseases. Additionally, we discuss the potential use of EVs in clinical settings. Rapid advancements in regenerative medicine and exosome-based drug delivery, in conjunction with an increased understanding of ocular pathology and pharmacology, hold great promise for the treatment of ocular diseases. The potential of exosome-based therapies is exciting and can revolutionize the way we approach these ocular conditions.

Enrichment of miR-17-5p enhances the protective effects of EPC-EXs on vascular and skeletal muscle injury in a diabetic hind limb ischemia model

BACKGROUND/AIMS

Diabetes mellitus (DM) is highly susceptible to diabetic hind limb ischemia (DHI). MicroRNA (MiR)-17-5p is downregulated in DM and plays a key role in vascular protection. Endothelial progenitor cell (EPC)-released exosomes (EPC-EXs) contribute to vascular protection and ischemic tissue repair by transferring their contained miRs to target cells. Here, we investigated whether miR-17-5p-enriched EPC-EXs (EPC-EXs^miR-17-5p) had conspicuous effects on protecting vascular and skeletal muscle in DHI in vitro and in vivo.

METHODS

EPCs transfected with scrambled control or miR-17-5p mimics were used to generate EPC-EXs and EPC-EXs^miR-17-5p. Db/db mice were subjected to hind limb ischemia. After the surgery, EPC-EXs and EPC-EXs^miR-17-5p were injected into the gastrocnemius muscle of the hind limb once every 7 days for 3 weeks. Blood flow, microvessel density, capillary angiogenesis, gastrocnemius muscle weight, structure integrity, and apoptosis in the hind limb were assessed. Vascular endothelial cells (ECs) and myoblast cells (C2C12 cells) were subjected to hypoxia plus high glucose (HG) and cocultured with EPC-EXs and EPC-EXs^miR-17-5p. A bioinformatics assay was used to analyze the potential target gene of miR-17-5p, the levels of SPRED1, PI3K, phosphorylated Akt, cleaved caspase-9 and cleaved caspase-3 were measured, and a PI3K inhibitor (LY294002) was used for pathway analysis.

RESULTS

In the DHI mouse model, miR-17-5p was markedly decreased in hind limb vessels and muscle tissues, and infusion of EPC-EXs^miR-17-5p was more effective than EPC-EXs in increasing miR-17-5p levels, blood flow, microvessel density, and capillary angiogenesis, as well as in promoting muscle weight, force production and structural integrity while reducing apoptosis in gastrocnemius muscle. In Hypoxia plus HG-injured ECs and C2C12 cells, we found that EPC-EXs^miR-17-5p could deliver their carried miR-17-5p into target ECs and C2C12 cells and subsequently downregulate the target protein SPRED1 while increasing the levels of PI3K and phosphorylated Akt. EPC-EXs^miR-17-5p were more effective than EPC-EXs in decreasing apoptosis and necrosis while increasing viability, migration, and tube formation in Hypoxia plus HG-injured ECs and in decreasing apoptosis while increasing viability and myotube formation in C2C12 cells. These effects of EPC-EXs^miR-17-5p could be abolished by a PI3K inhibitor (LY294002).

CONCLUSION

Our results suggest that miR-17-5p promotes the beneficial effects of EPC-EXs on DHI by protecting vascular ECs and muscle cell functions.

Extracellular Vesicles as reconfigurable therapeutics for eye diseases: Promises and hurdles

A large number of people worldwide suffer from visual impairment. However, most available therapies rely on impeding the development of a particular eye disorder. Therefore, there is an increasing demand for effective alternative treatments, specifically regenerative therapies. Extracellular vesicles, including exosomes, ectosomes, or microvesicles, are released by cells and play a potential role in regeneration. Following an introduction to EV biogenesis and isolation methods, this integrative review provides an overview of our current knowledge about EVs as a communication paradigm in the eye. Then, we focused on the therapeutic applications of EVs derived from conditioned medium, biological fluid, or tissue and highlighted some recent developments in strategies to boost the innate therapeutic potential of EVs by loading various kinds of drugs or being engineered at the level of producing cells or EVs. Challenges faced in the development of safe and effective translation of EV-based therapy into clinical settings for eye diseases are also discussed to pave the road toward reaching feasible regenerative therapies required for eye-related complications.

Stem cells and diabetic retinopathy: From models to treatment

Diabetic retinopathy is a common yet complex microvascular disease, caused as a complication of diabetes mellitus. Associated with hyperglycemia and subsequent metabolic abnormalities, advanced stages of the disease lead to fibrosis, subsequent visual impairment and blindness. Though clinical postmortems, animal and cell models provide information about the progression and prognosis of diabetic retinopathy, its underlying pathophysiology still needs a better understanding. In addition to it, the loss of pericytes, immature retinal angiogenesis and neuronal apoptosis portray the disease treatment to be challenging. Indulged with cell loss of both vascular and neuronal type cells, novel therapies like cell replacement strategies by various types of stem cells have been sightseen as a possible treatment of the disease. This review provides insight into the pathophysiology of diabetic retinopathy, current models used in modelling the disease, as well as the varied aspects of stem cells in generating three-dimensional retinal models. Further outlook on stem cell therapy and the future directions of stem cell treatment in diabetic retinopathy have also been contemplated.

Extracellular vesicles derived from different sources play various roles in diabetic retinopathy

Extracellular vesicles (EVs) are present in almost all biological fluids and secreted by almost all cell types. A growing number of studies have revealed the potential roles of EVs in the diagnosis and treatment of the diabetic retinopathy (DR). Changes in the quantity and content of EVs may serve as biomarkers of cause or consequence of pathological status of DR, such as inflammation, neovascularization and epithelial-mesenchymal transition. In addition, as natural, safe and efficient drug carrier, EVs have been reported to play important roles in intercellular communication by acting for essential cell-specific information to target cells. In this review, we summarize the roles of EVs, secreted by various types of cells and participated in various biological processes, in the pathogenesis, diagnosis, and treatment of DR.

Extracellular Vesicles and Vascular Inflammation

Vascular inflammation is the most common pathological feature in the pathogenesis of human disease. It is a complex immune process involved with many different types of cells including platelet, monocytes, macrophages, endothelial cells, and others. It is widely accepted that both innate and adaptive immune responses are important for the initiation and progression of vascular inflammation. The cell-cell interaction constitutes an important aspect of those immune responses in the vascular inflammation. Extracellular vesicles (EVs) are nanometer-sized double-layer lipid membrane vesicles released from most types of cells. They have been proved to play critical roles in intercellular communication in the occurrence and development of multisystem diseases. With the advancement of basal medical science, the biological roles of EVs in vascular inflammation have been clearer today. In this chapter, we will summarize the advance progress of extracellular vesicles in regulating vascular inflammation and its potential application in the clinical.

Noncoding RNAs Are Promising Therapeutic Targets for Diabetic Retinopathy: An Updated Review (2017-2022)

Diabetic retinopathy (DR) is the most common complication of diabetes. It is also the main cause of blindness caused by multicellular damage involving retinal endothelial cells, ganglial cells, and pigment epithelial cells in adults worldwide. Currently available drugs for DR do not meet the clinical needs; thus, new therapeutic targets are warranted. Noncoding RNAs (ncRNAs), a new type of biomarkers, have attracted increased attention in recent years owing to their crucial role in the occurrence and development of DR. NcRNAs mainly include microRNAs, long noncoding RNAs, and circular RNAs, all of which regulate gene and protein expression, as well as multiple biological processes in DR. NcRNAs, can regulate the damage caused by various retinal cells; abnormal changes in the aqueous humor, exosomes, blood, tears, and the formation of new blood vessels. This study reviews the different sources of the three ncRNAs-microRNAs, long noncoding RNAs, and circular RNAs-involved in the pathogenesis of DR and the related drug development progress. Overall, this review improves our understanding of the role of ncRNAs in various retinal cells and offers therapeutic directions and targets for DR treatment.

Mesenchymal Stem Cell-Derived Extracellular Vesicles: A Potential Therapy for Diabetes Mellitus and Diabetic Complications

As a novel cell-free strategy, mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) inherit the therapeutic potential of donor cells, and are widely used for the treatment of many diseases. Increasing studies have shown that MSC-EVs transfer various bioactive molecules to create a beneficial microenvironment, thus exerting protective roles in diabetic mellitus (DM) and diabetic complications. To overcome the limitations of natural MSC-EVs such as heterogeneity and insufficient function, several modification methods have been established for constructing engineered MSC-EVs with elevated repairing efficiency. In this review, the PubMed library was searched from inception to August 2022, using a combination of Medical Subject Headings (MeSH) and keywords related to MSC-EVs, DM, and diabetic complications. We provide an overview of the major characteristics of MSC-EVs and summarize the recent advances of MSC-EV-based therapy for hyperglycemia-induced tissue damage with an emphasis on MSC-EV-mediated delivery of functional components. Moreover, the potential applications of engineered MSC-EVs in DM-related diseases therapy are discussed by presenting examples, and the opportunities and challenges for the clinical translation of MSC-EVs, especially engineered MSC-EVs, are evaluated.

A Narrative Review of STAT Proteins in Diabetic Retinopathy: From Mechanisms to Therapeutic Prospects

Diabetic retinopathy (DR), a blinding disease, is one of the high-incidence chronic complications of diabetes. However, the current treatment for DR is mainly based on advanced pathological changes, which cannot reverse pre-existing retinal tissue damage and visual impairment. Signal transducer and activator of transcription (STAT) proteins are essential in DR through early and late stages. They participate in the early stage of DR through multiple mechanisms and have a strong proangiogenic effect in the late stage. Inhibiting STAT proteins activity has also achieved a significant effect in reversing the pathological changes of DR. Thus, STAT proteins are expected to be an effective therapeutic target in the early stage of DR and can make up for inadequate late treatment. This review introduces the structure, signal transduction mode, and biological functions of STAT proteins in detail and focuses on their role in the mechanism of DR. We also summarize the current research on STAT-related biological agents in DR, aiming to provide a theoretical basis for the treatment of DR.

Research progress of extracellular vesicles in type 2 diabetes and its complications

Type 2 diabetes is one of the most common chronic diseases in modern society. However, there is still insufficient research on the pathogenesis, diagnosis and treatment of type 2 diabetes and its complications. Extracellular vesicles are small bilayer vesicles secreted by cells. In recent years, the effect of extracellular vesicles in type 2 diabetes and its complications has aroused extensive attention. The research on the influence of protein and nucleic acids carried by extracellular vesicles secreted by stem cells and inflammatory cells on the pathogenesis of type 2 diabetes and its complications provides new ideas for its diagnosis and treatment. This review focuses on the influence of extracellular vesicles on insulin resistance by regulating inflammation and glucose transporter 4 expression. The second part mainly discusses the research progress and limitations of extracellular vesicles use in treating and diagnosing type 2 diabetes and its complications. This review introduces the current research status of type 2 diabetes and its complications, illustrates the biogenesis of extracellular vesicles, their effect on type 2 diabetes pathogenesis and its complications and their potential as therapeutic tools and diagnostic markers in type 2 diabetes and its complications.

Extracellular vesicles derived from human umbilical cord mesenchymal stem cells relieves diabetic retinopathy through a microRNA-30c-5p-dependent mechanism

AIMS

Extracellular vesicle (EV)-transferred microRNAs (miRNAs) are proved to be potentially therapeutic candidates. Here, we attempted to unveil the role of delivery of miR-30c-5p by human umbilical cord mesenchymal stem cells (hUCMSCs)-derived EVs in diabetic retinopathy (DR).

METHODS

miR-30c-5p and PLCG1 expression in streptozotocin-induced diabetes mellitus (DM) rats and high glucose (HG)-treated human retinal endothelial cells (HRECs) was quantified, followed by analysis on their interaction. EVs were isolated from hUCMSCs and co-cultured with HRECs. Through gain- and loss-of-function assays, the role of hUCMSCs-derived EV containing miR-30c-5p in DR involving PLCG1 and NF-κB pathway was analyzed in vitro and in vivo.

RESULTS

Elevated PLCG1 was found in DM rats and HG-treated HRECs where miR-30c-5p was reduced while increased in hUCMSC-derived EVs. PLCG1 was pinpointed as a target gene of miR-30c-5p, which consequently disrupted the PKC/NF-κB pathway. hUCMSC-derived EVs decreased inflammation reaction by transferring miR-30c-5p in DM rats and HG-treated HRECs. Furthermore, similar changing tendency was observed in HG-treated HRECs induced by overexpressed miR-30c-5p through downregulation of PLCG1 in vivo.

CONCLUSION

Overall, our findings underlined delivery of miR-30c-5p by hUCMSC-derived EVs as a novel suppressor in the inflammatory response following DR.

Engineering of MSC-Derived Exosomes: A Promising Cell-Free Therapy for Osteoarthritis

Osteoarthritis (OA) is characterized by progressive cartilage degeneration with increasing prevalence and unsatisfactory treatment efficacy. Exosomes derived from mesenchymal stem cells play an important role in alleviating OA by promoting cartilage regeneration, inhibiting synovial inflammation and mediating subchondral bone remodeling without the risk of immune rejection and tumorigenesis. However, low yield, weak activity, inefficient targeting ability and unpredictable side effects of natural exosomes have limited their clinical application. At present, various approaches have been applied in exosome engineering to regulate their production and function, such as pretreatment of parental cells, drug loading, genetic engineering and surface modification. Biomaterials have also been proved to facilitate efficient delivery of exosomes and enhance treatment effectiveness. Here, we summarize the current understanding of the biogenesis, isolation and characterization of natural exosomes, and focus on the large-scale production and preparation of engineered exosomes, as well as their therapeutic potential in OA, thus providing novel insights into exploring advanced MSC-derived exosome-based cell-free therapy for the treatment of OA.

The Extracellular MicroRNAs on Inflammation: A Literature Review of Rodent Studies

Inflammation is an indispensable biological process stimulated by infection and injuries. Inflammatory mechanisms related to extracellular vesicles (EVs), which are small membrane structures carrying various molecules, were summarized in this review. Emerging evidence from animal studies has highlighted the role of EVs in modulating inflammatory responses, by transporting various molecules involved in host defense. In this review, we have discussed the role of EV miRNAs in inflammation. Rodent studies associated with extracellular miRNAs in inflammatory diseases, published from 2012 to 2022, were explored from PUBMED, EMBASE, and MEDLINE. A total of 95 studies were reviewed. In summary, EV-associated miRNAs play a key role in various diseases, including organ injury, immune dysfunction, neurological disease, metabolic syndrome, vesicular disease, arthritis, cancer, and other inflammatory diseases. Diverse EV-associated miRNAs regulate inflammasome activation and pro- and anti-inflammatory cytokine levels by targeting genes.

Current Status of Mesenchymal Stem/Stromal Cells for Treatment of Neurological Diseases

Neurological disorders include a wide spectrum of clinical conditions affecting the central and peripheral nervous systems. For these conditions, which affect hundreds of millions of people worldwide, generally limited or no treatments are available, and cell-based therapies have been intensively investigated in preclinical and clinical studies. Among the available cell types, mesenchymal stem/stromal cells (MSCs) have been widely studied but as yet no cell-based treatment exists for neurological disease. We review current knowledge of the therapeutic potential of MSC-based therapies for neurological diseases, as well as possible mechanisms of action that may be explored to hasten the development of new and effective treatments. We also discuss the challenges for culture conditions, quality control, and the development of potency tests, aiming to generate more efficient cell therapy products for neurological disorders.

Biodistribution of Intra-Arterial and Intravenous Delivery of Human Umbilical Cord Mesenchymal Stem Cell-Derived Extracellular Vesicles in a Rat Model to Guide Delivery Strategies for Diabetes Therapies

Umbilical cord mesenchymal stem cell-derived extracellular vesicles (UC-MSC-EVs) have become an emerging strategy for treating various autoimmune and metabolic disorders, particularly diabetes. Delivery of UC-MSC-EVs is essential to ensure optimal efficacy of UC-MSC-EVs. To develop safe and superior EVs-based delivery strategies, we explored nuclear techniques including positron emission tomography (PET) to evaluate the delivery of UC-MSC-EVs in vivo. In this study, human UC-MSC-EVs were first successfully tagged with I-124 to permit PET determination. Intravenous (I.V.) and intra-arterial (I.A.) administration routes of [124I]I-UC-MSC-EVs were compared and evaluated by in vivo PET-CT imaging and ex vivo biodistribution in a non-diabetic Lewis (LEW) rat model. For I.A. administration, [124I]I-UC-MSC-EVs were directly infused into the pancreatic parenchyma via the celiac artery. PET imaging revealed that the predominant uptake occurred in the liver for both injection routes, and further imaging characterized clearance patterns of [124I]I-UC-MSC-EVs. For biodistribution, the uptake (%ID/gram) in the spleen was significantly higher for I.V. administration compared to I.A. administration (1.95 ± 0.03 and 0.43 ± 0.07, respectively). Importantly, the pancreas displayed similar uptake levels between the two modalities (0.20 ± 0.06 for I.V. and 0.24 ± 0.03 for I.A.). Therefore, our initial data revealed that both routes had similar delivery efficiency for [124I]I-UC-MSC-EVs except in the spleen and liver, considering that higher spleen uptake could enhance immunomodulatory application of UC-MSC-EVs. These findings could guide the development of safe and efficacious delivery strategies for UC-MSC-EVs in diabetes therapies, in which a minimally invasive I.V. approach would serve as a better delivery strategy. Further confirmation studies are ongoing.

Noncoding RNAs from tissue-derived small extracellular vesicles: Roles in diabetes and diabetic complications

Diabetes is a systemic disease, and its progression involves multiple organ dysfunction. However, the exact mechanisms underlying pathological progression remain unclear. Small extracellular vesicles (sEVs) mediate physiological and pathological signaling communication between organs and have been shown to have important regulatory roles in diabetes and its complications in recent years. In particular, the majority of studies in the diabetes-related research field have focused on the noncoding RNAs carried by sEVs. Researchers found that noncoding RNA sorting into sEVs is not random but selective. Both tissue origin differences and environmental variations affect the cargo of sEVs. In addition, the function of sEVs differs according to the tissue they derive from; for example, sEVs derived from adipose tissue regulate insulin sensitivity in the periphery, while sEVs derived from bone marrow promote β-cell regeneration. Therefore, understanding the roles of sEVs from different tissues is important for elucidating their molecular mechanisms and is necessary for the application of sEVs as therapeutic agents for diabetes treatment in the future. In this review, we summarized current studies on the mechanisms of noncoding RNA sorting into sEVs, as well as the research progress on the effects of sEVs from different tissue origins and noncoding RNAs in diabetes and diabetic complications. The knowledge of noncoding RNAs in sEVs will help us better understand the role of sEVs in the diabetes progression.

Genetic Modification as a New Approach to Ameliorate the Therapeutic Efficacy of Stem Cells in Diabetic Retinopathy

Over the last decades, the strategy of using stem cells has gained a lot of attention in treating many diseases. Recently, DR was identified as one of the common complications experienced by diabetic patients around the world. The current treatment strategy needs to be addressed since the active progression of DR may lead to permanent blindness. Interestingly, varieties of stem cells have emerged to optimize the therapeutic effects. It is also known that stem cells possess multilineage properties and are capable of differentiating, expanding in vitro and undergoing genetic modification. Moreover, modified stem cells have shown to be an ideal resource to prevent the degenerative disease and exhibit promising effects in conferring the migratory, anti-apoptotic, anti-inflammatory and provide better homing for cells into the damaged tissue or organ as well promoting healing properties. Therefore, the understanding of the functional properties of the stem cells may provide the comprehensive guidance to understand the manipulation of stem cells making them useful for long-term therapeutic applications. Hence in this review the potential use and current challenges of genetically modified stem cells to treat DR will be discussed along with its future perspectives.

Exosomes for diabetes syndrome: ongoing applications and perspective

Diabetes mellitus, ranking the ninth death cause in the world, is a kind of metabolic disease characterized by hyperglycemia. Without timely and effective treatment, many ensuing complications involved with heart,...

The roles of mesenchymal stem cell-derived exosomes in diabetes mellitus and its related complications

Diabetes mellitus is a type of metabolic disease characterized by hyperglycemia, primarily caused by defects in insulin secretion, insulin action, or both. Long-term chronic hyperglycemia can lead to diabetes-related complications, causing damage, dysfunction, and failure of different organs. However, traditional insulin and oral drug therapy can only treat the symptoms but not delay the progressive failure of pancreatic beta cells or prevent the emergence of diabetic complications. Mesenchymal stem cells have received extensive attention due to their strong immunoregulatory functions and regeneration effects. Mesenchymal stem cell-derived exosomes (MSC-Exos) have been proposed as a novel treatment for diabetic patients as they have demonstrated superior efficiency to mesenchymal stem cells. This review summarizes the therapeutic effects, mechanisms, challenges, and future prospects of MSC-Exos in treating diabetes mellitus and its related complications. This review supports the potential use of MSC-Exos in future regenerative medicine to overcome the current difficulties in clinical treatment, particularly in treating diabetes.

Roles and mechanisms of exosomal non-coding RNAs in human health and diseases

Exosomes play a role as mediators of cell-to-cell communication, thus exhibiting pleiotropic activities to homeostasis regulation. Exosomal non-coding RNAs (ncRNAs), mainly microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), are closely related to a variety of biological and functional aspects of human health. When the exosomal ncRNAs undergo tissue-specific changes due to diverse internal or external disorders, they can cause tissue dysfunction, aging, and diseases. In this review, we comprehensively discuss the underlying regulatory mechanisms of exosomes in human diseases. In addition, we explore the current knowledge on the roles of exosomal miRNAs, lncRNAs, and circRNAs in human health and diseases, including cancers, metabolic diseases, neurodegenerative diseases, cardiovascular diseases, autoimmune diseases, and infectious diseases, to determine their potential implication in biomarker identification and therapeutic exploration.