Exosomes: Effectual players in rheumatoid arthritis

Natural biomimetic nano-system for drug delivery in the treatment of rheumatoid arthritis: a literature review of the last 5 years

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease characterized primarily by synovitis, leading to the destruction of articular cartilage and bone and ultimately resulting in joint deformity, loss of function, and a significant impact on patients' quality of life. Currently, a combination of anti-rheumatic drugs, hormonal drugs, and biologics is used to mitigate disease progression. However, conventional drug therapy has limited bioavailability, and long-term use often leads to drug resistance and toxic side effects. Therefore, exploring new therapeutic approaches for RA is of great clinical importance. Nanodrug delivery systems offer promising solutions to overcome the limitations of conventional drugs. Among them, liposomes, the first nanodrug delivery system to be approved for clinical application and still widely studied, demonstrate the ability to enhance therapeutic efficacy with fewer adverse effects through passive or active targeting mechanisms. In this review, we provide a review of the research progress on the targeting mechanisms of various natural biomimetic nano-delivery systems in RA therapy. Additionally, we predict the development trends and application prospects of these systems, offering new directions for precision treatment of RA.

Diagnostic, prognostic, and therapeutic potential of exosomal microRNAs in renal cancer

Renal cell carcinoma (RCC) arises from the tubular epithelial cells of the nephron. It has the highest mortality rate among urological cancers. There are no effective therapeutic approaches and no non-invasive biomarkers for diagnosis and follow-up. Thus, suitable novel biomarkers and therapeutic targets are essential for improving RCC diagnosis/prognosis and treatment. Circulating exosomes such as exosomal microRNAs (Exo-miRs) provide non-invasive prognostic/diagnostic biomarkers and valuable therapeutic targets, as they can be easily isolated and quantified and show high sensitivity and specificity. Exosomes secreted by an RCC can exhibit alterations in the miRs' profile that may reflect the cellular origin and (patho)physiological state, as a ''signature'' or ''fingerprint'' of the donor cell. It has been shown that the transportation of renal-specific miRs in exosomes can be rapidly detected and measured, holding great potential as biomarkers in RCC. The present review highlights the studies reporting tumor microenvironment-derived Exo-miRs with therapeutic potential as well as circulating Exo-miRs as potential diagnostic/prognostic biomarkers in patients with RCC.

Identification of serum exosomal miRNA biomarkers for diagnosis of Rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis (RA) is an autoimmune disorder characterized by inflammation-induced joint damage, which can cause lasting disability. Therefore, early diagnosis and treatment of RA are crucial. Herein, we evaluated whether exosomal microRNAs (miRNAs) could be served as promising biomarkers that can accelerate the diagnosis of RA and development of therapies for RA.

METHODS

First, we performed small RNA sequencing to determine the miRNA profiles of serum exosomes within a screening cohort comprised of 18 untreated active RA patients, along with 18 age and gender-matched healthy controls (HCs). Subsequently, the miRNA profiles were then validated in a training cohort consisting of 24 RA patients and 24 HCs by RT-qPCR. Finally, the selected exosomal miRNAs were validated in a larger cohort comprising 108 RA patients and 103 HCs. The diagnostic efficacy of the exosomal miRNAs was evaluated by receiver operating characteristic (ROC) curve analysis. Biological functions of the miRNAs were determined by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses.

RESULTS

Our results first demonstrated a noteworthy upregulation of three candidate miRNAs (miR-885-5p, miR-6894-3p, and miR-1268a) in the RA patients' serum exosomes compared to HCs. The combination of three miRNAs along with anti- citrullinated peptide antibodies (ACPA) exhibited excellent diagnostic accuracy, yielding an area under the curve (AUC) of 0.963 (95 % CI : 0.941-0.984), sensitivity of 87.96 %, and specificity of 93.20 %. Notably, miR-885-5p exhibited remarkable discriminatory capacity by itself in indistinguishing ACPA- negative RA patients from HCs, with an AUC of 0.993 (95 % CI : 0.978-1.000), sensitivity of 96.67 %, and specificity of 100 %. Moreover, the expression of miR-1268a in the assessment of therapeutic effectiveness displayed significant reduction on 29th day of Methotrexate (MTX) treatment in RA patients. This decreased expression paralleled with trends observed in tender 28-joint count (TJC28), swollen 28-joint count (SJC28), and disease activity score with 28-joint count using C-reactive protein (DAS28-CRP), all of which are indicative of RA disease activity. Finally, predictive analysis indicated that, these three exosomal miRNAs target pivotal signaling molecules involved in inflammatory pathways, thereby demonstrating effective modulation of the immune system.

CONCLUSIONS

In this study, we successfully demonstrated the promising potential for serum exosomal miRNAs, particularly miR-885-5p, miR-6894-3p and miR-1268a as biomarkers for early diagnosis and prediction of RA for the first time.

Exosome-mediated delivery of super-repressor IκBα alleviates inflammation and joint damages in rheumatoid arthritis

BACKGROUND

This study aims to investigate the potential anti-inflammatory effects of exosomes engineered to carry super-repressor IκB (Exo-srIκB), an exosome-based NF-κB inhibitor, in the context of RA.

METHODS

Peripheral blood mononuclear cells (PBMCs) and synovial fluid mononuclear cells (SFMCs) were collected from patients diagnosed with RA and treated with Exo-srIκB to test the therapeutic potential. Flow cytometry analysis was performed to assess the production of inflammatory cytokines (IL-17A and GM-CSF) by the cells. ELISA was utilized to measure the levels of TNF-α, IL-17A, IL-6, and GM-CSF. Arthritis was induced in SKG mice by intraperitoneal injection of curdlan. DBA/1 J mice were used in collagen-induced arthritis (CIA) experiments. After the development of arthritis, mice were injected with either Exo-Naïve (control exosome) or Exo-srIκB. Arthritis scores were recorded biweekly, and histological observations of the ankle joint were conducted using H&E and safranin-O staining. Additionally, bone erosion was evaluated using micro-CT imaging.

RESULTS

In the ex vivo study involving human PBMCs and SFMCs, treatment with Exo-srIκB demonstrated a notable reduction in inflammatory cytokines. Furthermore, in both the SKG and CIA models, Exo-srIκB treatment exhibited significant reductions in inflammation, cartilage destruction, and bone erosion within the joint tissues when compared to the Exo-Naive control group. Additionally, the radiographic score assessed through microCT showed a significant decrease compared to the Exo-Naive control group.

CONCLUSION

Overall, these findings suggest that Exo-srIκB possesses anti-inflammatory properties in human RA cells and animal models, making it a promising therapeutic candidate for the treatment of RA.

The Comparative Effects of Schwann Cells and Wharton's Jelly Mesenchymal Stem Cells on the AIM2 Inflammasome Activity in an Experimental Model of Spinal Cord Injury

Inflammasome activation and the consequent release of pro-inflammatory cytokines play a crucial role in the development of sensory/motor deficits following spinal cord injury (SCI). Immunomodulatory activities are exhibited by Schwann cells (SCs) and Wharton's jelly mesenchymal stem cells (WJ-MSCs). In this study, we aimed to compare the effectiveness of these two cell sources in modulating the absent in melanoma 2 (AIM2) inflammasome complex in rats with SCI. The Basso, Beattie, Bresnahan (BBB) test, Nissl staining, and Luxol fast blue (LFB) staining were performed to evaluate locomotor function, neuronal survival, and myelination, respectively. Real-time polymerase chain reaction (RT-PCR), Western blotting, and enzyme-linked immunosorbent assay (ELISA) were employed to analyze the gene and protein expressions of inflammasome components, including AIM2, ASC, caspase-1, interleukin-1β (IL-1β), and IL-18. Both gene and protein expressions of all evaluated factors were decreased after SC or WJ-MSC treatment, with a more pronounced effect observed in the SCs group (P < 0.05). Additionally, SCs promoted neuronal survival and myelination. Moreover, the administration of 3 × 105 cells resulted in motor recovery improvement in both treatment groups (P < 0.05). Although not statistically significant, these effects were more prominent in the SC-treated animals. In conclusion, SC therapy demonstrated greater efficacy in targeting AIM2 inflammasome activation and the associated inflammatory pathway in SCI experiments compared to WJ-MSCs.

Proteomic and genomic profiling of plasma exosomes from patients with ankylosing spondylitis

INTRODUCTION

Recent advances in understanding the biology of ankylosing spondylitis (AS) using innovative genomic and proteomic approaches offer the opportunity to address current challenges in AS diagnosis and management. Altered expression of genes, microRNAs (miRNAs) or proteins may contribute to immune dysregulation and may play a significant role in the onset and persistence of inflammation in AS. The ability of exosomes to transport miRNAs across cells and alter the phenotype of recipient cells has implicated exosomes in perpetuating inflammation in AS. This study reports the first proteomic and miRNA profiling of plasma-derived exosomes in AS using comprehensive computational biology analysis.

METHODS

Plasma samples from patients with AS and healthy controls (HC) were isolated via ultracentrifugation and subjected to extracellular vesicle flow cytometry analysis to characterise exosome surface markers by a multiplex immunocapture assay. Cytokine profiling of plasma-derived exosomes and cell culture supernatants was performed. Next-generation sequencing was used to identify miRNA populations in exosomes enriched from plasma fractions. CD4+ T cells were sorted, and the frequency and proliferation of CD4+ T-cell subsets were analysed after treatment with AS-exosomes using flow cytometry.

RESULTS

The expression of exosome marker proteins CD63 and CD81 was elevated in the patients with AS compared with HC (q<0.05). Cytokine profiling in plasma-derived AS-exosomes demonstrated downregulation of interleukin (IL)-8 and IL-10 (q<0.05). AS-exosomes cocultured with HC CD4+ T cells induced significant upregulation of IFNα2 and IL-33 (q<0.05). Exosomes from patients with AS inhibited the proliferation of regulatory T cells (Treg), suggesting a mechanism for chronically activated T cells in this disease. Culture of CD4+ T cells from healthy individuals in the presence of AS-exosomes reduced the proliferation of FOXP3+ Treg cells and decreased the frequency of FOXP3+IRF4+ Treg cells. miRNA sequencing identified 24 differentially expressed miRNAs found in circulating exosomes of patients with AS compared with HC; 22 of which were upregulated and 2 were downregulated.

CONCLUSIONS

Individuals with AS have different immunological and genetic profiles, as determined by evaluating the exosomes of these patients. The inhibitory effect of exosomes on Treg in AS suggests a mechanism contributing to chronically activated T cells in this disease.

Gout therapeutics and drug delivery

Gout is a common inflammatory arthritis caused by persistently elevated uric acid levels. With the improvement of people's living standards, the consumption of processed food and the widespread use of drugs that induce elevated uric acid, gout rates are increasing, seriously affecting the human quality of life, and becoming a burden to health systems worldwide. Since the pathological mechanism of gout has been elucidated, there are relatively effective drug treatments in clinical practice. However, due to (bio)pharmaceutical shortcomings of these drugs, such as poor chemical stability and limited ability to target the pathophysiological pathways, traditional drug treatment strategies show low efficacy and safety. In this scenario, drug delivery systems (DDS) design that overcome these drawbacks is urgently called for. In this review, we initially describe the pathological features, the therapeutic targets, and the drugs currently in clinical use and under investigation to treat gout. We also comprehensively summarize recent research efforts utilizing lipid, polymeric and inorganic carriers to develop advanced DDS for improved gout management and therapy.

Proteomics profiling of CD4 + T-cell-derived exosomes from patients with rheumatoid arthritis

OBJECTIVES

Our study profiled the CD4 + T-cell-derived exosomes from patients with rheumatoid arthritis (RA) using proteomics.

METHODS

Proteomic analysis of CD4 + T-cell-derived exosomes was performed by tandem mass tags (TMT) combined with LC-MS/MS. We validated the most significantly upregulated and downregulated proteins using ELISA and WB.

RESULTS

The proteomic results showed that there were 3 upregulated differentially expressed proteins and 31 downregulated differentially expressed proteins in the RA group. The results indicated that dihydropyrimidinase-related protein 3 (DPYSL3) was significantly upregulated in CD4 + T-cell-derived exosomes, whereas proteasome activator complex subunit 1 (PSME1) was significantly downregulated in the RA group. Bioinformatics analysis showed that proteins were enriched in "positive regulation of gene expression", "antigen processing and presentation", "acute-phase response" and "PI3K-AKT signaling" pathways. ELISA verified that compared to the control group, the RA group showed significant upregulation of DPYSL3, and downregulation of PSME1 in CD4 + T-cell-derived exosomes.

CONCLUSIONS

The proteomic analysis results of CD4 + T-cell-derived exosomes from patients with RA suggest that these differentially expressed proteins may be involved in RA pathogenesis. DPYSL3 and PSME1 may become useful biomarkers for RA.

The developing role of extracellular vesicles in autoimmune diseases: special attention to mesenchymal stem cell-derived extracellular vesicles

Autoimmune diseases are complex, chronic inflammatory conditions initiated by the loss of immunological tolerance to self-antigens. Nowadays, there is no effective and useful therapy for autoimmune diseases, and the existing medications have some limitations due to their nonspecific targets and side effects. During the last few decades, it has been established that mesenchymal stem cells (MSCs) have immunomodulatory functions. It is proposed that MSCs can exert an important therapeutic effect on autoimmune disorders. In parallel with these findings, several investigations have shown that MSCs alleviate autoimmune diseases. Intriguingly, the results of studies have demonstrated that the effective roles of MSCs in autoimmune diseases do not depend on direct intercellular communication but on their ability to release a wide spectrum of paracrine mediators such as growth factors, cytokines and extracellular vehicles (EVs). EVs that range from 50 to 5,000 nm were produced by almost any cell type, and these nanoparticles participate in homeostasis and intercellular communication via the transfer of a broad range of biomolecules such as modulatory proteins, nucleic acids (DNA and RNA), lipids, cytokines, and metabolites. EVs derived from MSCs display the exact properties of MSCs and can be safer and more beneficial than their parent cells. In this review, we will discuss the features of MSCs and their EVs, EVs biogenesis, and their cargos, and then we will highlight the existing discoveries on the impacts of EVs from MSCs on autoimmune diseases such as multiple sclerosis, arthritis rheumatic, inflammatory bowel disease, Type 1 diabetes mellitus, systemic lupus erythematosus, autoimmune liver diseases, Sjögren syndrome, and osteoarthritis, suggesting a potential alternative for autoimmune conditions therapy.

Dysregulation of circRNAs in rheumatoid arthritis, with special emphasis on circRNAs secreted by exosomes and the crosstalk between circRNAs and RNA methylations

BACKGROUND

Rheumatoid arthritis (RA) is an autoimmune disease caused by a variety of unknown factors. It mainly occurs in the small joints of hands and feet, leading to cartilage destruction and bone erosion. Various pathologic mechanisms such as exosomes and RNA methylations are involved in the pathogenesis of RA.

METHODS

This work searches PubMed, Web of Science (SCIE) and Science Direct Online (SDOL) databases, it role of abnormally expressed circulating RNAs (circRNAs) in the pathogenesis of RA was summarized. And the relationship between circRNAs and exosomes and methylations.

RESULTS

Both the abnormal expression of circRNAs and the sponge effect of circRNAs on microRNAs (miRNAs) affect the pathogenesis of RA by regulating target genes. CircRNAs affect the proliferation, migration and inflammatory reaction of RA-fibroblast-like synovial cells (FLSs), circRNAs in peripheral blood mononuclear cells (PBMCs) and macrophages also participate in the pathological mechanism of RA (Fig. 1). CircRNAs in exosomes are closely related to the pathogenesis of RA. In addition, exosomal circRNAs and the relationship between circRNAs and RNA methylations are closely related to the pathogenesis of RA.

CONCLUSION

CircRNAs play an important role in the pathogenesis of RA and have the potential to be a new target for the diagnosis and treatment of RA. However, the development of mature circRNAs for clinical application is not a small challenge.

Genetically Engineered Exosomes as a Potential Regulator of Th1 Cells Response in Rheumatoid Arthritis

Background: Rheumatoid arthritis is a long-lasting inflammatory disease that usually involves joints, but it can also affect other organs, including the skin and lungs. In this case, it is important to maintain a balance between beneficial pro-inflammatory activity and harmful overactivation of the T helper cells (Th). We strive to investigate in this study the possibilities for the effect of mesenchymal stem cells (MSCs)-derived exosomes containing miR-146a/miR-155 on the lymphocyte population and function. Methods: Exosomes were isolated from overexpressed miR-146a/miR-155 MSCs for the purpose of this analysis. Splenocytes were isolated from collagen-induced arthritis (CIA) and control mice. It was important to consider the expressions of certain predominant autoimmune-response genes, including T-bet and interferon-γ (IFNγ), by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay. It turned out to be a significant consideration with p < 0.05. Results: The results are expressed in percentages with respect to miR-146a/AntimiR-155 transduced MSC-derived exosomes treatment, which significantly decreased the mRNA expression level of IFNγ in healthy mice (p < 0.05). miR-146a transduced MSC-derived exosomes treatment significantly reduced the mRNA expression level of IFNγ in CIA mice (p < 0.05). It should be noted that the secretion of the pro-inflammatory factor IFNγ in CIA mice was inhibited in almost all groups (p < 0.05). Conclusion: Many research groups have mainly focused on strategies for reducing pro-inflammatory cytokines. This approach was recently suggested and investigated in our research team and suggested that manipulation of MSCs-derived exosomes could minimize pro-inflammatory cytokine production to strike a balance among Th subsets. These approaches tend to appear to achieve better results in the regulation of the immune system by the use of engineered exosomes derived from MSCs. By providing accurate information the reasonably practicable use of exosomes for cell-free therapy can be established.

Deregulation of exosomal miRNAs in rheumatoid arthritis patients

Exosomes are small-diameter endosomal vesicles secreted in all biological fluids and play biological/pathological roles in the cell. These pathological roles are played by exosome's cargo molecules through inter-cellular communication. Exosomal cargo molecules contain proteins and miRNAs. miRNAs are small non-coding RNA fragments involved in the reduction of final protein output by destabilizing or suppressing the translation of target messenger RNA (mRNA). This deregulation of the protein due to miRNAs ultimately accelerates the process of disease pathogenesis. The role of exosomal miRNAs has been investigated in different diseases and the limited number of studies have been published concerning exosomal miRNAs and rheumatoid arthritis (RA). The current study is designed to investigate the role of exosomal miRNAs (miRNA-103a-3p, miRNA-10a-5p, miRNA-204-3p, miRNA-330-3p, and miRNA-19b) in the pathogenesis of RA. Furthermore, the role of selected exosomal miRNAs in RA pathogenesis was further explored by estimating oxidative stress and histone deacetylation in RA patients. In the current study, 306 RA patients and equal numbers of age/gender-matched controls were used. The level of expression of above-mentioned exosomal miRNAs was assessed by performing qRT PCR. Deacetylation and oxidative stress assays were performed to estimate the 8-hydroxydeoxyguanosine (8-OHdG level) and histone deacetylation levels using the Enzyme-linked immunosorbent assay (ELISA). Statistical analysis indicated a significantly downregulated expression of miRNA-103a-3p (p<0.0001), miR-10a-5p (p<0.0001), miR-204-3p (p<0.0001), miR-330-3p (p<0.0001) and miR-19b (p<0.0001) in RA patients compared to controls. Significantly increased levels of 8-OHdG (p<0.0001) and histone deacetylation (p<0.0001) were observed among RA patients compared to controls. Spearman correlation showed a negative correlation between the deregulated exosomal miRNAs and increased oxidative stress and histone deacetylation in RA patients. Receiver operating characteristics (ROC) curve analysis showed a good diagnostic specificity/sensitivity of the above-mentioned exosomal miRNAs among RA patients. These analyses indicated the potential role of deregulated exosomal miRNAs in the initiation of RA by targeting oxidative stress and histone deacetylation processes.

A Bird’s Eye View of Various Cell-Based Biomimetic Nanomedicines for the Treatment of Arthritis

Arthritis is the inflammation and tenderness of the joints because of some metabolic, infectious, or constitutional reasons. Existing arthritis treatments help in controlling the arthritic flares, but more advancement is required to cure arthritis meticulously. Biomimetic nanomedicine represents an exceptional biocompatible treatment to cure arthritis by minimizing the toxic effect and eliminating the boundaries of current therapeutics. Various intracellular and extracellular pathways can be targeted by mimicking the surface, shape, or movement of the biological system to form a bioinspired or biomimetic drug delivery system. Different cell-membrane-coated biomimetic systems, and extracellular-vesicle-based and platelets-based biomimetic systems represent an emerging and efficient class of therapeutics to treat arthritis. The cell membrane from various cells such as RBC, platelets, macrophage cells, and NK cells is isolated and utilized to mimic the biological environment. Extracellular vesicles isolated from arthritis patients can be used as diagnostic tools, and plasma or MSCs-derived extracellular vesicles can be used as a therapeutic target for arthritis. Biomimetic systems guide the nanomedicines to the targeted site by hiding them from the surveillance of the immune system. Nanomedicines can be functionalized using targeted ligand and stimuli-responsive systems to reinforce their efficacy and minimize off-target effects. This review expounds on various biomimetic systems and their functionalization for the therapeutic targets of arthritis treatment, and discusses the challenges for the clinical translation of the biomimetic system.

Exosomes as Rheumatoid Arthritis Diagnostic Biomarkers and Therapeutic Agents

Rheumatoid arthritis (RA) is a chronic inflammatory joint disorder that causes systemic inflammation, autoimmunity, and joint abnormalities that result in permanent disability. Exosomes are nanosized extracellular particles found in mammals (40–100 nm). They are a transporter of lipids, proteins, and genetic material involved in mammalian cell–cell signaling, biological processes, and cell signaling. Exosomes have been identified as playing a role in rheumatoid arthritis-related joint inflammation (RA). Uniquely functioning extracellular vesicles (EVs) are responsible for the transport of autoantigens and mediators between distant cells. In addition, paracrine factors, such as exosomes, modulate the immunomodulatory function of mesenchymal stem cells (MSCs). In addition to transporting genetic information, exosomes convey miRNAs between cells and have been studied as drug delivery vehicles. In animal models, it has been observed that MSCs secrete EVs with immunomodulatory properties, and promising results have been observed in this area. By understanding the diversity of exosomal contents and their corresponding targets, it may be possible to diagnose autoimmune diseases. Exosomes can be employed as diagnostic biomarkers for immunological disorders. We here discuss the most recent findings regarding the diagnostic, prognostic, and therapeutic potential of these nanoparticles in rheumatoid arthritis and provide an overview of the evidence pertaining to the biology of exosomes in RA.

Exosomes derived from human adipose-derived stem cells alleviate hepatic ischemia-reperfusion (I/R) injury through the miR-183/ALOX5 axis

Ischemia-reperfusion (I/R) injury is a crucial factor causing liver injury in the clinic. Recent research has confirmed that human adipose-derived stem cells (ADSCs) can differentiate into functional hepatocytes. However, the mechanism of the effects of ADSCs in the treatment of liver injury remains unclear. The characteristics of ADSCs were first identified, and exosome-derived ADSCs were isolated and characterized. The function and mechanism of action of miR-183 and arachidonate 5-lipoxygenase (ALOX5) were investigated by functional experiments in HL-7702 cells with I/R injury and in I/R rats. Our data disclosed that exosome release from ADSCs induced proliferation and inhibited apoptosis in HL-7702 cells with I/R injury. The effect of miR-183 was similar to that of exosomes derived from ADSCs. In addition, ALOX5, as a target gene of miR-183, was involved in the related functions of miR-183. Moreover, in vivo experiments confirmed that miR-183 and exosomes from ADSCs could improve liver injury in rats and inhibit the MAPK and NF-κB pathways. All of these findings demonstrate that exosomes derived from ADSCs have a significant protective effect on hepatic I/R injury by regulating the miR-183/ALOX5 axis, which might provide a therapeutic strategy for liver injury.

Exosomes: A missing link between chronic systemic inflammation and Alzheimer's disease?

Exosomes are potent mediators of physiological and pathological processes. In Alzheimer's disease and inflammatory disorders, due to exosomes' distinctive ability to cross the blood-brain barrier, a bidirectional communication between the periphery and the central nervous system exists. Since exosomes can carry various biochemical molecules, this review investigates the role of exosomes as possible mediators between chronic systemic inflammatory diseases and Alzheimer's disease. Exosomes carry pro-inflammatory molecules generated in the periphery, travel to the central nervous system, and target glial and neuronal cells. Microglia and astrocytes then become activated, initiating chronic neuroinflammation. As the aging brain is more susceptible to such changes, this state of neuroinflammation can stimulate neuropathologies, impair amyloid-beta clearance capabilities, and generate dysregulated microRNAs that alter the expression of genes critical in Alzheimer's disease pathology. These processes, individually and collectively, become significant risk factors for the development of Alzheimer's disease.

How statin drugs affect exosomes?

Statins reduce serum cholesterol and isoprenoids by the inhibition of cholesterol synthesis in the mevalonate pathway. Exosomes are extracellular vesicles (30-200 nm) released by all cells that regulate cell-to-cell communication in health and disease by transferring functional proteins, metabolites and nucleic acids to recipient cells. There are many reports that show an effect of statins on exosomes, from their production and release to their content and performance. In this review, we have summarized existing data on the impact of statins on the biosynthesis, secretion, content, uptake and function of exosomes.

Vesicular traffic-mediated cell-to-cell signaling at the immune synapse in Ankylosing Spondylitis

The chronic inflammatory disease ankylosing spondylitis (AS) is marked by back discomfort, spinal ankylosis, and extra-articular symptoms. In AS, inflammation is responsible for both pain and spinal ankylosis. However, the processes that sustain chronic inflammation remain unknown. Despite the years of research conducted to decipher the intricacy of AS, little progress has been made in identifying the signaling events that lead to the development of this disease. T cells, an immune cell type that initiates and regulates the body's response to infection, have been established to substantially impact the development of AS. T lymphocytes are regarded as a crucial part of adaptive immunity for the control of the immune system. A highly coordinated interaction involving antigen-presenting cells (APCs) and T cells that regulate T cell activation constitutes an immunological synapse (IS). This first phase leads to the controlled trafficking of receptors and signaling mediators involved in folding endosomes to the cellular interface, which allows the transfer of information from T cells to APCs through IS formation. Discrimination of self and nonself antigen is somatically learned in adaptive immunity. In an autoimmune condition such as AS, there is a disturbance of self/nonself antigen discrimination; available findings imply that the IS plays a preeminent role in the adaptive immune response. In this paper, we provide insights into the genesis of AS by evaluating recent developments in the function of vesicular trafficking in IS formation and the targeted release of exosomes enriched microRNAs (miRNA) at the synaptic region in T cells.

Proteomic profiling of extracellular vesicles in synovial fluid and plasma from Oligoarticular Juvenile Idiopathic Arthritis patients reveals novel immunopathogenic biomarkers

Introduction

New early low-invasive biomarkers are demanded for the management of Oligoarticular Juvenile Idiopathic Arthritis (OJIA), the most common chronic pediatric rheumatic disease in Western countries and a leading cause of disability. A deeper understanding of the molecular basis of OJIA pathophysiology is essential for identifying new biomarkers for earlier disease diagnosis and patient stratification and to guide targeted therapeutic intervention. Proteomic profiling of extracellular vesicles (EVs) released in biological fluids has recently emerged as a minimally invasive approach to elucidate adult arthritis pathogenic mechanisms and identify new biomarkers. However, EV-prot expression and potential as biomarkers in OJIA have not been explored. This study represents the first detailed longitudinal characterization of the EV-proteome in OJIA patients.

Methods

Fourty-five OJIA patients were recruited at disease onset and followed up for 24 months, and protein expression profiling was carried out by liquid chromatography-tandem mass spectrometry in EVs isolated from plasma (PL) and synovial fluid (SF) samples.

Results

We first compared the EV-proteome of SF vs paired PL and identified a panel of EV-prots whose expression was significantly deregulated in SF. Interaction network and GO enrichment analyses performed on deregulated EV-prots through STRING database and ShinyGO webserver revealed enrichment in processes related to cartilage/bone metabolism and inflammation, suggesting their role in OJIA pathogenesis and potential value as early molecular indicators of OJIA development. Comparative analysis of the EV-proteome in PL and SF from OJIA patients vs PL from age/gender-matched control children was then carried out. We detected altered expression of a panel of EV-prots able to differentiate new-onset OJIA patients from control children, potentially representing a disease-associated signature measurable at both the systemic and local levels with diagnostic potential. Deregulated EV-prots were significantly associated with biological processes related to innate immunity, antigen processing and presentation, and cytoskeleton organization. Finally, we ran WGCNA on the SF- and PL-derived EV-prot datasets and identified a few EV-prot modules associated with different clinical parameters stratifying OJIA patients in distinct subgroups.

Discussion

These data provide novel mechanistic insights into OJIA pathophysiology and an important contribution in the search of new candidate molecular biomarkers for the disease.

Research progress on exosomes in podocyte injury associated with diabetic kidney disease

Diabetic kidney disease (DKD), a common cause of end-stage renal disease, is a serious complication that develops with the progression of chronic diabetes. Its main clinical manifestations are persistent proteinuria and/or a progressive decline in the estimated glomerular filtration rate. Podocytes, terminally differentiated glomerular visceral epithelial cells, constitute the glomerular filtration barrier together with the basement membrane and endothelial cells, and the structural and functional barrier integrity is closely related to proteinuria. In recent years, an increasing number of studies have confirmed that podocyte injury is the central target of the occurrence and development of DKD, and research on exosomes in podocyte injury associated with DKD has also made great progress. The aim of this review is to comprehensively describe the potential diagnostic value of exosomes in podocyte injury associated with DKD, analyze the mechanism by which exosomes realize the communication between podocytes and other types of cells and discuss the possibility of exosomes as targeted therapy drug carriers to provide new targets for and insights into delaying the progression of and treating DKD.

Role of exosomes in tumour growth, chemoresistance and immunity: state-of-the-art

Cancer is one of the most lethal diseases, and limited available treatment options contribute to its high mortality rate. Exosomes are considered membrane-bound nanovesicles that include different molecules such as lipids, proteins, and nucleic acids. Virtually most cells could release exosomes via exocytosis in physiological and pathological conditions. Tumour-derived exosomes (TDEs) play essential roles in tumorigenesis, proliferation, progression, metastasis, immune escape, and chemoresistance by transferring functional biological cargos, triggering different autocrine, and paracrine signalling cascades. Due to their antigen-presenting properties, exosomes are widely used as biomarkers and drug carriers and have a prominent role in cancer immunotherapy. They offer various advantages in carrier systems (e.g. in chemotherapy, siRNA, and miRNA), delivery of diagnostic agents owing to their stability, loading of hydrophobic and hydrophilic agents, and drug targeting. Novel exosomes-based carriers can be generated as intelligent systems using various sources and crosslinking chemistry extracellular vesicles (EVs). Exosomes studded with targeting ligands, including peptides, can impart in targeted delivery of cargos to tumour cells. In this review, we comprehensively summarised the important role of tumour-derived exosomes in dictating cancer pathogenesis and resistance to therapy. We have therefore, investigated in further detail the pivotal role of tumour-derived exosomes in targeting various cancer cells and their applications, and prospects in cancer therapy and diagnosis. Additionally, we have implicated the potential utility and significance of tumour exosomes-based nanoparticles as an efficient and novel therapeutic carrier and their applications in treating advanced cancers.

Exosomes derived from fibrinogen-like protein 1-overexpressing bone marrow-derived mesenchymal stem cells ameliorates rheumatoid arthritis

Rheumatoid arthritis (RA) is a most common chronic joint disease belonging to inflammatory autoimmune disease. The aim of this study was to determine the role and mechanism of bone marrow mesenchymal stem cells (BMSCs)-derived exosomes and fibrinogen-like protein 1 (FGL1) overexpression exosomes shuttled by BMSCs (FGL1-Exos) on RA. All of the exosomes were visualized by transmission electron microscope (TEM) and the characteristic proteins were detected by western blot. To investigate the therapeutic effect of FGL1-Exos, RA-FLSs were activated by TNF-α and RA rat model was established by collagen incomplete Freund's adjuvant. Cell viability, apoptosis, inflammation factors, and protein levels were detected by CCK-8, flow cytometry, enzyme-linked immunosorbent assay and western blot, respectively. Hematoxylin and eosin and safranin O staining were used to detect the histopathology changes. Cell apoptosis and FGL1 expression in knee joint were detected by immunofluorescence. The results showed that FGL1-Exos could inhibit the cell viability meanwhile increase the cell apoptosis in RA-FLSs. Meanwhile, FGL1-Exos could effectively suppress the inflammation score, joint destruction, and inflammatory response in RA rat model. FGL1-Exos directly inhibited cell apoptosis of RA-FLSs and RA rat model by suppressing the inflammatory cytokines, specific rheumatoid markers, immunological markers meanwhile meditating the NF-κB pathway. Our results indicate that FGL1 was a therapeutic potential target in RA therapy.

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.

Research progress on the role and mechanism of action of exosomes in autoimmune thyroid disease

Exosomes are widely distributed extracellular vesicles (EVs), which are currently a major research hotspot for researchers based on their wide range of sources, stable membrane structure, low immunogenicity, and containing a variety of biomolecules. A large number of literatures have shown that exosomes and exosome cargoes (especially microRNAs) play an important role in the activation of inflammation, development of tumor, differentiation of cells, regulation of immunity and so on. Studies have found that exosomes can stimulate the immune response of the body and participate in the occurrence and development of various diseases, including autoimmune diseases. Furthermore, the potential of exosomes as therapeutic tools in various diseases has also attracted much attention. Autoimmune thyroid disease (AITD) is one of the most common autoimmune diseases, mainly composed of Graves' disease (GD) and Hashimoto's thyroiditis (HT), which affects the health of many people and has a genetic predisposition, but its pathogenesis is still being explored. Starting from the relevant biological characteristics of exosomes, this review summarizes the current research status of exosomes and the association between exosomes and some diseases, with a focus on the situation of AITD and the potential role of exosomes (including substances in their vesicles) in AITD in combination with the current published literature, aiming to provide new directions for the pathogenesis, diagnosis or therapy of AITD.Supplemental data for this article is available online at.

Extracellular vesicles delivering nuclear factor I/C for hard tissue engineering: Treatment of apical periodontitis and dentin regeneration

Apical periodontitis (AP) causes arrest of tooth root development, which is associated with impaired odontoblastic differentiation of stem cells from apical papilla (SCAPs), but the underlying mechanism remains unclear. Here, we investigated roles of extracellular vesicle (EV) in AP and odontoblastic differentiation of SCAPs, moreover, a novel nuclear factor I/C (NFIC)-encapsulated EV was developed to promote dentin regeneration. We detected a higher expression of EV marker CD63 in inflamed apical papilla, and found that EVs from LPS-stimulated dental pulp cells suppressed odontoblastic differentiation of SCAPs through downregulating NFIC. Furthermore, we successfully constructed the NFIC-encapsulated EV by overexpressing NFIC in HEK293FT cells, which could upregulate cellular NFIC level in SCAPs, promoting the proliferation and migration of SCAPs, as well as dentinogenesis both in vitro and in vivo. Collectively, based on pathological roles of EV in AP, our study provides a novel strategy for dentin regeneration by exploiting EV to deliver NFIC.

The role of exosomal miRNA in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) impacts more than one-third of the population and is linked with other metabolic diseases. The term encompasses a wide spectrum of diseases, from modest steatosis to nonalcoholic steatohepatitis, fibrosis and, ultimately, cirrhosis with the potential for development of hepatocellular carcinoma. Currently, available methods for diagnosing NAFLD are invasive or lack accuracy, and monitoring to determine response to therapeutic interventions is challenging. Exosomes are nano-scaled extracellular vesicles that are secreted by a variety of cells. They convey proteins, mRNA, miRNA, and other bioactive molecules between cells and are involved in an extensive range of biological processes, particularly cell-cell communication. Several reports suggest that exosomes mediate miRNAs and, thus, they have potential clinical utility for diagnosis, prognosis, and therapeutics in liver diseases. In view of the vital role of exosomal microRNA in disease, we here synthesized current knowledge about the biogenesis of exosomal miRNA and exosome-mediated microRNA transfer. We then discuss the potential of exosomal miRNA in diagnosis and therapeutics of NAFLD.

Wu-Teng-Gao External Treatment Improves Th17/Treg Balance in Rheumatoid Arthritis

Rheumatoid arthritis (RA) represents the consequence of an immune response of the body's immune system attacking healthy cells. This chronic inflammatory disorder has complicated pathogenesis. Traditional Chinese medicine (TCM) is well recognized as an effective therapy in treating RA and has been widely applied for centuries. Wu-Teng-Gao (WTG) is used as a representative natural herb formula in RA treatment in China, while its mechanisms are to be fully clarified. The present study attempted to explore mechanisms of WTG on RA treatment in a network pharmacological approach and verified using experiments in vitro. Following the establishment of a rat model of collagen-induced arthritis (CIA), WTG was applied externally on the metapedes of rats. HE staining was subsequently performed to visualize the pathological changes of synovium and bone. Simultaneously, flow cytometry was conducted to detect the cell ratio of T helper 17 (Th17) and Regulatory T cells (Treg) in splenic lymphocytes. Additionally, ELISA, qRT-PCR, and Western blot assays were adopted to determine expressions of RA-related factors in joints and serum. Results of network pharmacological analysis suggested that Th17 cell differentiation might serve as a potential signaling pathway of WTG therapy for RA. Animal experiments demonstrated that WTG ameliorated the articular inflammation and effectively inhibited the destruction of articular cartilage, and decreased Th17 and Treg cell ratios in CIA rats. Furthermore, WTG also greatly suppressed relevant levels of inflammatory cytokines (IL-17, TNF-α, IL-1, and IL-6) and RNAKL, whereas it elevated expressions of anti-inflammatory cytokines IL-10 and TGF-β. Our results confirmed that WTG might improve the imbalance of Th17/Treg cells in CIA animals through differentiation regulation, thus alleviating joint inflammation and bone destruction.

Stem cell-derived and circulating exosomal microRNAs as new potential tools for diabetic nephropathy management

BACKGROUND

Despite major advances in the treatment of diabetic nephropathy (DN) in recent years, it remains the most common cause of end-stage renal disease. An early diagnosis and therapy may slow down the DN progression. Numerous potential biomarkers are currently being researched. Circulating levels of the kidney-released exosomes and biological molecules, which reflect the DN pathology including glomerular and tubular dysfunction as well as mesangial expansion and fibrosis, have shown the potential for predicting the occurrence and progression of DN. Moreover, many experimental therapies are currently being investigated, including stem cell therapy and medications targeting inflammatory, oxidant, or pro-fibrotic pathways activated during the DN progression. The therapeutic potential of stem cells is partly depending on their secretory capacity, particularly exosomal microRNAs (Exo-miRs). In recent years, a growing line of research has shown the participation of Exo-miRs in the pathophysiological processes of DN, which may provide effective therapeutic and biomarker tools for DN treatment.

METHODS

A systematic literature search was performed in MEDLINE, Scopus, and Google Scholar to collect published findings regarding therapeutic stem cell-derived Exo-miRs for DN treatment as well as circulating Exo-miRs as potential DN-associated biomarkers.

FINDINGS

Glomerular mesangial cells and podocytes are the most important culprits in the pathogenesis of DN and, thus, can be considered valuable therapeutic targets. Preclinical investigations have shown that stem cell-derived exosomes can exert beneficial effects in DN by transferring renoprotective miRs to the injured mesangial cells and podocytes. Of note, renoprotective Exo-miR-125a secreted by adipose-derived mesenchymal stem cells can improve the injured mesangial cells, while renoprotective Exo-miRs secreted by adipose-derived stem cells (Exo-miR-486 and Exo-miR-215-5p), human urine-derived stem cells (Exo-miR-16-5p), and bone marrow-derived mesenchymal stem cells (Exo-miR-let-7a) can improve the injured podocytes. On the other hand, clinical investigations have indicated that circulating Exo-miRs isolated from urine or serum hold great potential as promising biomarkers in DN.

Circulating extracellular vesicles and rheumatoid arthritis: a proteomic analysis

Circulating extracellular vesicles (EVs) are membrane-bound nanoparticles secreted by most cells for intracellular communication and transportation of biomolecules. EVs carry proteins, lipids, nucleic acids, and receptors that are involved in human physiology and pathology. EV cargo is variable and highly related to the type and state of the cellular origin. Three subtypes of EVs have been identified: exosomes, microvesicles, and apoptotic bodies. Exosomes are the smallest and the most well-studied class of EVs that regulate different biological processes and participate in several diseases, such as cancers and autoimmune diseases. Proteomic analysis of exosomes succeeded in profiling numerous types of proteins involved in disease development and prognosis. In rheumatoid arthritis (RA), exosomes revealed a potential function in joint inflammation. These EVs possess a unique function, as they can transfer specific autoantigens and mediators between distant cells. Current proteomic data demonstrated that exosomes could provide beneficial effects against autoimmunity and exert an immunosuppressive action, particularly in RA. Based on these observations, effective therapeutic strategies have been developed for arthritis and other inflammatory disorders.

TSP1 is the essential domain of SEMA5A involved in pannus formation in rheumatoid arthritis

OBJECTIVE

In this study, we explored the effect of semaphorin5A (SEMA5A) on RA pathogenesis and its specific TSP1 domain on pannus formation.

METHODS

The expression of SEMA5A was detected in the synovium, the fibroblast-like synoviocytes (FLSs) and the SF of RA patients and healthy controls (HCs) by real-time quantitative PCR (q-PCR), immunohistochemistry staining, western blot and ELISA. SEMA5A-mAb intervention was performed to appraise the severity of joints in the CIA model. Transcriptome sequencing and bioinformatics analysis in SEMA5A-transfected FLSs from HCs were performed to screen differentially expressed genes after SEMA5A overexpression. An MTT assay in RA-FLSs, a chicken embryo allantoic membrane experiment and a tube formation experiment were used to clarify the influence of SEMA5A on cell proliferation and angiogenesis. Furthermore, a rescue experiment verified the function of the TSP1 domain of SEMA5A in the progress of RA with Sema5a-/- CIA mice.

RESULTS

The expression of SEMA5A increased in RA compared with that in HCs. Simultaneously, SEMA5A-mAbs significantly attenuated joint injury and the inflammatory response in CIA models. In addition, transcriptome sequencing and angiogenesis-related experiments verified the ability of SEMA5A to promote FLS proliferation and angiogenesis. Moreover, TSP1 was proved to be an essential domain in SEMA5A-induced angiogenesis in vitro. Additionally, rescue of TSP1-deleted SEMA5A failed to reduce the severity of arthritis in a CIA model constructed with Sema5a -/- mice.

CONCLUSION

In summary, upregulation of SEMA5A was first confirmed in pathological lesions of RA patients. Furthermore, treatment with SEMA5A-mAbs attenuated the progress of RA in the CIA model. Moreover, TSP1 was indicated as the key domain of SEMA5A in the promotion of pannus formation in RA.

Role of microRNA Shuttled in Small Extracellular Vesicles Derived From Mesenchymal Stem/Stromal Cells for Osteoarticular Disease Treatment

Osteoarticular diseases (OD), such as rheumatoid arthritis (RA) and osteoarthritis (OA) are chronic autoimmune/inflammatory and age-related diseases that affect the joints and other organs for which the current therapies are not effective. Cell therapy using mesenchymal stem/stromal cells (MSCs) is an alternative treatment due to their immunomodulatory and tissue differentiation capacity. Several experimental studies in numerous diseases have demonstrated the MSCs’ therapeutic effects. However, MSCs have shown heterogeneity, instability of stemness and differentiation capacities, limited homing ability, and various adverse responses such as abnormal differentiation and tumor formation. Recently, acellular therapy based on MSC secreted factors has raised the attention of several studies. It has been shown that molecules embedded in extracellular vesicles (EVs) derived from MSCs, particularly those from the small fraction enriched in exosomes (sEVs), effectively mimic their impact in target cells. The biological effects of sEVs critically depend on their cargo, where sEVs-embedded microRNAs (miRNAs) are particularly relevant due to their crucial role in gene expression regulation. Therefore, in this review, we will focus on the effect of sEVs derived from MSCs and their miRNA cargo on target cells associated with the pathology of RA and OA and their potential therapeutic impact.

Astrocyte-Derived Extracellular Vesicles (ADEVs): Deciphering their Influences in Aging

Astrocytes are an abundant and dynamic glial cell exclusive to the central nervous system (CNS). In the context of injury, inflammation, and/or diseases of the nervous system, astrocyte responses, termed reactive astrogliosis, are a recognized pathological feature across a range of conditions and diseases. However, the impact of reactive astrogliosis is not uniform and varies by context and duration (time). In recent years, extracellular communication between glial cells via extracellular vesicles (EVs) has garnered interest as a process connected with reactive astrogliosis. In this review, we relate recent findings on astrocyte-derived extracellular vesicles (ADEVs) with a focus on factors that can influence the effects of ADEVs and identified age related changes in the function of ADEVs. Additionally, we will discuss the current limitations of existing experimental approaches and identify questions that highlight areas for growth in this field, which will continue to enhance our understanding of ADEVs in age-associated processes.

A Review of the Clinical and Therapeutic Implications of Neuropathic Pain

Understanding neuropathic pain presents several challenges, given the various mechanisms underlying its pathophysiological classification and the lack of suitable tools to assess its diagnosis. Furthermore, the response of this pathology to available drugs is still often unpredictable, leaving the treatment of neuropathic pain still questionable. In addition, the rise of personalized treatments further extends the ramified classification of neuropathic pain. While a few authors have focused on neuropathic pain clustering, by analyzing, for example, the presence of specific TRP channels, others have evaluated the presence of alterations in microRNAs to find tailored therapies. Thus, this review aims to synthesize the available evidence on the topic from a clinical perspective and provide a list of current demonstrations on the treatment of this disease.

The role of extracellular vesicles in rheumatoid arthritis: a systematic review

Rheumatoid arthritis (RA) is a chronic inflammatory disease that carries high social and economic costs and can lead to permanent disability. RA pathogenesis has not been completely elucidated yet. Extracellular vesicles (EVs) are membrane-contained vesicles released by cells playing a role in cell-to-cell communication and they could be involved in different diseases. Evidence on the involvement of EVs in RA is currently inconclusive. Therefore, a systematic review on the role of EVs in RA was performed in order to explore this relationship. This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The research was conducted on PubMed, Scopus, and Embase up to March 5, 2020: 41 studies were analyzed out of 674 screened. The total plasmatic and synovial fluid (SF) EV number seems increased in RA as compared with healthy controls. Both RA plasma and SF contained EVs subpopulations of heterogenous origin, especially derived from platelets and immune system cells. No univocal evidence emerged on miRNA expression and EV content profile within RA patients. EVs showed to enhance pro-inflammatory pathways, such as cytokines and chemokine release and TNF blockade seemed to revert this effect. Our work highlights the requirement to standardize study methodologies in order to make results comparable and draw conclusions that remain, at present, unclear.

Exosomes as a new pain biomarker opportunity

Exosomes are extracellular microvesicles implicated in intercellular communication with ability to transfer cargo molecules, including protein, lipids, and nucleic acids, at both close and distant target sites. It has been shown that exosomes are implicated in physiological and pathological processes. In recent years, the interest on exosomes’ role in many pain states has increased. Their involvements in pain processes have been demonstrated by studies on different chronic pain diseases, both inflammatory and neuropathic, such as osteoarthritis, rheumatoid arthritis, inflammatory bowel diseases, neurodegenerative pathologies, complex regional pain syndrome, and peripheral nerve injury. Animal and clinical studies investigated exosomes-based treatments, showing their ability to improve painful symptoms with fewer side effects, with potential immunoprotective and anti-inflammatory effect. Specific molecular patterns characterize exosomes’ cargo according to the cellular origin, epigenetic modifications, environmental state, and stressor factors. Therefore, the identification of specific cargo’s profile associated to pain states may lead to recognize specific pathological states and to consider the use of exosomes as biomarkers of diseases. Furthermore, exosomes’ ability to transfer information and their presence in many accessible biological fluids suggest a potential use as novel non-invasive therapeutic tools in pain field.

Extracellular Vesicles in chondrogenesis and Cartilage regeneration

Extracellular vesicles (EVs), mainly exosomes and microvesicles, are bilayer lipids containing biologically active information, including nucleic acids and proteins. They are involved in cell communication and signalling, mediating many biological functions including cell growth, migration and proliferation. Recently, EVs have received great attention in the field of tissue engineering and regenerative medicine. Many in vivo and in vitro studies have attempted to evaluate the chondrogenesis potential of these microstructures and their roles in cartilage regeneration. EVs derived from mesenchymal stem cells (MSCs) or chondrocytes have been found to induce chondrocyte proliferation and chondrogenic differentiation of stem cells in vitro. Preclinical studies have shown that exosomes derived from MSCs have promising results in cartilage repair and in cell‐free therapy of osteoarthritis. This review will focus on the in vitro and in vivo chondrogenesis and cartilage regeneration of EVs as well as their potential in the treatment of osteoarthritis.

The Impact of Immune Cell-derived Exosomes on Immune Response Initiation and Immune System Function

Exosomes are small extracellular vesicles that pass genetic material between various cells to modulate or alter their biological function. The role of exosomes is to communicate with the target cell for cell-to-cell communication. Their inherent characteristics of exosomes, such as adhesion molecules, allow targeting specifically to the receiving cell. Exosomes are involved in cell to cell communication in the immune system including antigen presentation, natural killer cells (NK cells) and T cell activation/polarisation, immune suppression and various anti-inflammatory processes. In this review, we have described various functions of exosomes secreted by the immune cells in initiating, activating and modulating immune responses; and highlight the distinct roles of exosomal surface proteins and exosomal cargo. Potential applications of exosomes such as distribution vehicles for immunotherapy are also discussed.

Gut microbiota-microRNA interactions in ankylosing spondylitis

Ankylosing spondylitis (AS) is a chronic autoimmune inflammatory disability that is part of the rheumatic disease group of spondyloarthropathies. AS commonly influences the joints of the axial skeleton. The contributions to AS pathogenesis of genetic susceptibility (particularly HLA-B27 and ERAP-1) and epigenetic modifications, like non-coding RNAs, as well as environmental factors, have been investigated over the last few years. But the fundamental etiology of AS remains elusive to date. The evidence summarized here indicates that in the immunopathogenesis of AS, microRNAs and the gut microbiome perform critical functions. We discuss significant advances in the immunological mechanisms underlying AS and address potential cross-talk between the gut microbiome and host microRNAs. This critical interaction implicates a co-evolutionary symbiotic link between host immunity and the gut microbiome.

Quantification of Circulating Cell Free Mitochondrial DNA in Extracellular Vesicles with PicoGreen™ in Liquid Biopsies: Fast Assessment of Disease/Trauma Severity

The analysis of circulating cell free DNA (ccf-DNA) is an emerging diagnostic tool for the detection and monitoring of tissue injury, disease progression, and potential treatment effects. Currently, most of ccf-DNA in tissue and liquid biopsies is analysed with real-time quantitative PCR (qPCR) that is primer- and template-specific, labour intensive and cost-inefficient. In this report we directly compare the amounts of ccf-DNA in serum of healthy volunteers, and subjects presenting with various stages of lung adenocarcinoma, and survivors of traumatic brain injury using qPCR and quantitative PicoGreen™ fluorescence assay. A significant increase of ccf-DNA in lung adenocarcinoma and traumatic brain injury patients, in comparison to the group of healthy human subjects, was found using both analytical methods. However, the direct correlation between PicoGreen™ fluorescence and qPCR was found only when mitochondrial DNA (mtDNA)-specific primers were used. Further analysis of the location of ccf-DNA indicated that the majority of DNA is located within lumen of extracellular vesicles (EVs) and is easily detected with mtDNA-specific primers. We have concluded that due to the presence of active DNases in the blood, the analysis of DNA within EVs has the potential of providing rapid diagnostic outcomes. Moreover, we speculate that accurate and rapid quantification of ccf-DNA with PicoGreen™ fluorescent probe used as a point of care approach could facilitate immediate assessment and treatment of critically ill patients.

Current Status of Functional Studies on Circular RNAs in Rheumatoid Arthritis and Their Potential Role as Diagnostic Biomarkers

Circular RNAs (circRNAs), a new class of endogenous non-coding RNAs (ncRNAs), are highly stable and exhibit tissue-specific expression. Accumulating evidence has indicated that circRNAs play crucial roles in the development and progression of multiple diseases. Notably, circRNAs, important epigenetic modulators of gene expression in inflammation and autoimmune regulation, have a close association with the pathogenesis of rheumatoid arthritis (RA). RA, one of the most common systemic autoimmune diseases, is characterized by synovial hyperplasia and inflammation, and cartilage and bone destruction. Here, we focus on the roles of circRNAs in macrophage, synovial tissues, fibroblast-like synoviocytes (FLSs), and cartilage tissues in pathogenesis and progression of RA, highlighting the potential of circRNAs in the blood as diagnostic biomarkers, and aiming at providing new insights into the diagnosis and therapy of this disease.

Application of nanomaterials in the treatment of rheumatoid arthritis

Rheumatoid Arthritis (RA) is a chronic autoimmune disease, which mainly causes inflammation of the synovial joints and destruction of cartilage and bone tissue. At present, a variety of clinical drugs have been applied in the treatment of rheumatoid arthritis. With the development of nanotechnology, more and more nano-drugs have been applied in the treatment of rheumatoid arthritis due to the unique physical and chemical properties of nanomaterials. Treatment of RA with nanomaterials can improve bioavailability and selectively target damaged joint tissue. In this review, we summarized the progress of the application of nanomaterials in the treatment of rheumatoid arthritis and also proposed challenges faced by nanomaterials in the treatment of rheumatoid arthritis.

Therapeutic Application of Exosomes in Inflammatory Diseases

Immunomodulation is on the cusp of being an important therapy for treating many diseases, due to the significant role of the immune system in defending the human body. Although the immune system is an essential defense system, overactivity can result in diverse sicknesses such as inflammation and autoimmune disease. Exosomes are emerging as a state-of-the-art therapeutic strategy for treating an overactive immune system. Thus, in this review, we will thoroughly review therapeutic applications of exosomes in various inflammatory and autoimmune diseases. Finally, issues for an outlook to the future of exosomal therapy will be introduced.

Mechanisms underlying low-clinical responses to PD-1/PD-L1 blocking antibodies in immunotherapy of cancer: a key role of exosomal PD-L1

Exosomes, as the main group of extracellular vesicles, are biologically active lipid-bilayer vesicles that are naturally released from different types of normal or tumor cells. These vesicles play an important role in intercellular communication and influence the extracellular environment and the immune system. Emerging evidence demonstrates that cancer-derived exosomes are enriched in immunosuppressive proteins, such as the programmed death-ligand 1 (PD-L1). PD-L1 and its receptor programmed cell death protein 1 (PD-1) are the key immune checkpoint molecules that promote tumor progression via negative regulation of immune responses. PDL-1 is highly expressed on the surface of tumor cells and binds to PD-1 on the surface of activated T cells, leading to suppression of T cells, which consequently enables cancer cells to escape antitumor immunity. Currently, there are several Food and Drug Administration-approved monoclonal antibodies blocking PD-1/PD-L1 interaction, which are clinically used for cancer treatment. However, despite impressive treatment outcomes, some patients show poor response to PD-1/PD-L1 blockade. Of note, tumor-derived exosomes containing PD-L1 can recapitulate the effect of cell-surface PD-L1. There is evidence that reveals a significant association between levels of circulating exosomal PD-L1 and rate of response to anti-PD-1/PD-L1 antibody therapy. The present article reviews the role of exosomal PDL-1 in the therapeutic resistance to anti-PD-1/PD-L1 treatment. Importantly, it is suggested that the removal of exosomal PDL-1 could serve as a therapeutic adjuvant for enhancing the efficacy of anti-PD-1/PD-L1 therapy in patients with cancer.

The Utility of Exosomes in Diagnosis and Therapy of Diabetes Mellitus and Associated Complications

Diabetes mellitus and the associated complications are metabolic diseases with high morbidity that result in poor quality of health and life. The lack of diagnostic methods for early detection results in patients losing the best treatment opportunity. Oral hypoglycemics and exogenous insulin replenishment are currently the most common therapeutic strategies, which only yield temporary glycemic control rather than curing the disease and its complications. Exosomes are nanoparticles containing bioactive molecules reflecting individual physiological status, regulating metabolism, and repairing damaged tissues. They function as biomarkers of diabetes mellitus and diabetic complications. Considering that exosomes are bioactive molecules, can be obtained from body fluid, and have cell-type specificity, in this review, we highlight the multifold effects of exosomes in the pathology and therapy of diabetes mellitus and diabetic complications.

LncRNA HAND2-AS1 suppressed the growth of triple negative breast cancer via reducing secretion of MSCs derived exosomal miR-106a-5p

Background: Triple-negative breast cancer (TNBC) is a special type of breast cancer, its tumor cell metastasis rate is much higher than other types, and at the same time has a high rate of postoperative recurrence, which significantly threatens the health of women. Thus, it is urgent to explore a new treatment for TNBC.

Results: MiR-106a-5p was up-regulated in TNBC tissues and cells, and was positively correlated with the tumor grade, which indicated poor prognosis in TNBC patients. Mesenchymal stem cells (MSCs) can transport miR-106a-5p into TNBC cells via exosomes. Functional analysis showed exo-miR-106a-5p secreted by MSCs promoted tumor progression in TNBC cells. Furthermore, lncRNA HAND2-AS1 inhibited miR-106a-5p levels, and HAND2-AS1 was decreased in TNBC tissues and cells. Besides, overexpression of HAND2-AS1 reduced the secretion of exo-miR-106a-5p secretion from MSCs, thus suppressed TNBC development.

Conclusion: Our study revealed that HAND2-AS1 inhibited the growth of TNBC, which were mediated by the inhibitory effects of MSC-derived exosomal miR-106a-5p.

miRNA-146a Improves Immunomodulatory Effects of MSC-derived Exosomes in Rheumatoid Arthritis

Background:

Rheumatoid arthritis (RA) is a severe inflammatory joint disorder, and several studies have taken note of the probability that microRNAs (miRNAs) play an important role in RA pathogenesis. MiR-146 and miR-155 arose as primary immune response regulators. Mesenchymal stem cells (MSCs) immunomodulatory function is primarily regulated by paracrine factors, such as exosomes. Exosomes, which serve as carriers of genetic information in cell-to-cell communication, transmit miRNAs between cells and have been studied as vehicles for the delivery of therapeutic molecules.

Aims:

The current research aimed to investigate the therapeutic effect of miR-146a/miR-155 transduced mesenchymal stem cells (MSC)-derived exosomes on the immune response.

Methods:

Here, exosomes were extracted from normal MSCs with over-expressed miR-146a/miR-155; Splenocytes were isolated from collagen-induced arthritis (CIA) and control mice. Expression levels miR-146a and miR-155 were then monitored. Flow cytometry was performed to assess the impact of the exosomes on regulatory T-cell (Treg) levels. Expression of some key autoimmune response genes and their protein products, including retinoic acid-related orphan receptor (ROR)-γt, tumor necrosis factor (TNF)-α, interleukin (IL)-17, -6, -10, and transforming growth factor (TGF)-β in the Splenocytes was determined using both quantitative real-time PCR and ELISA. The results showed that miR-146a was mainly down-regulated in CIA mice. Treatment with MSC-derived exosomes and miR-146a/miR-155-transduced MSC-derived exosomes significantly altered the CIA mice Treg cell levels compared to in control mice.

Results:

Ultimately, such modulation may promote the recovery of appropriate T-cell responses in inflammatory situations such as RA.

Conclusion:

miR-146a-transduced MSC-derived exosomes also increased forkhead box P3 (Fox- P3), TGFβ and IL-10 gene expression in the CIA mice; miR-155 further increased the gene expressions of RORγt, IL-17, and IL-6 in these mice. Based on the findings here, Exosomes appears to promote the direct intracellular transfer of miRNAs between cells and to represent a possible therapeutic strategy for RA. The manipulation of MSC-derived exosomes with anti-inflammatory miRNA may increase Treg cell populations and anti-inflammatory cytokines.

Proteomic analysis of extracellular vesicles reveals an immunogenic cargo in rheumatoid arthritis synovial fluid

Objectives

Extracellular vesicles (EVs) from rheumatoid arthritis (RA) synovial fluid (SF) have been reported to stimulate the release of pro-inflammatory mediators from recipient cells. We recently developed a size exclusion chromatography (SEC)-based method for EV isolation capable of high-quality enrichments from human SF. Here, we employed this method to accurately characterise the SF EV proteome and investigate potential contributions to inflammatory pathways in RA.

Methods

Using our SEC-based approach, SF EVs were purified from the joints of RA patients classified as having high-level (n = 7) or low-level inflammation (n = 5), and from osteoarthritis (OA) patients (n = 5). Protein profiles were characterised by mass spectrometry. Potential contributions of EV proteins to pathological pathways and differences in protein expression between disease groups were investigated.

Results

Synovial fluid EVs were present at higher concentrations in RA joints with high-level inflammation (P-value = 0.004) but were smaller in diameter (P-value = 0.03) than in low-level inflammation. In total, 1058 SF EV proteins were identified by mass spectrometry analysis. Neutrophil and fibroblast markers were overrepresented in all disease groups. Numerous proteins with potential to modulate inflammatory and immunological processes were detected, including nine citrullinated peptides. Forty-five and 135 EV-associated proteins were significantly elevated in RA joints with high-level inflammation than in RA joints with low-level inflammation and OA joints, respectively. Gene ontology analysis revealed significant enrichment for proteins associated with 'neutrophil degranulation' within SF EVs from RA joints with high-level inflammation.

Conclusion

Our results provide new information about SF EVs and insight into how EVs might contribute to the perpetuation of RA.

Therapeutic angiogenesis with exosomal microRNAs: an effectual approach for the treatment of myocardial ischemia

Therapeutic angiogenesis presents a potential approach for treating ischemic heart diseases especially in patients who are not appropriate candidates for traditional approaches of revascularization. This approach acts through inducing the neovascularization or maturation of pre-existing collateral vessels into functional arteries to bypass the blocked arteries and restore perfusion to ischemic myocardium. Successful stimulation of local angiogenesis can be established by the cross talk between stem cells, endothelial cells, and cardiomyocytes, which is mainly mediated by paracrine communication accompanied by secreted exosomes. Exosomes are extracellular vesicles carrying a complex of signaling molecules, such as microRNAs (miRs) that can modulate the function of recipient cells. Such particles have been indicated to exert cardioprotective role through providing signaling cues for angiogenesis, an effect ascribed mainly to their miRs content. Exosomal miRs-mediated therapeutic angiogenesis has been under drastic preclinical and clinical studies. In the current review, it was aimed to summarize pro-angiogenic exosomal miRs released by various cell types mediating angiogenesis, including stem cells, endothelial cells, and cardiomyocytes, which appear to exert a therapeutic effect on the myocardial ischemia. In brief, secreted exosomal miRs including miR-210, miR-23a-3p, miR-424, let-7f, miR-30b, miR-30c, miR-126, miR-21, miR-132, miR-130a-3p, miR-214, miR-378, miR-126, miR-133, and let-7b-5p could protect against myocardial ischemia through inducing cardiac angiogenesis and vascular regeneration resulting in the increase blood flow to ischemic myocardium.

Inducible Polarized Secretion of Exosomes in T and B Lymphocytes

Exosomes are extracellular vesicles (EV) of endosomal origin (multivesicular bodies, MVB) constitutively released by many different eukaryotic cells by fusion of MVB to the plasma membrane. However, inducible exosome secretion controlled by cell surface receptors is restricted to very few cell types and a limited number of cell surface receptors. Among these, exosome secretion is induced in T lymphocytes and B lymphocytes when stimulated at the immune synapse (IS) via T-cell receptors (TCR) and B-cell receptors (BCR), respectively. IS formation by T and B lymphocytes constitutes a crucial event involved in antigen-specific, cellular, and humoral immune responses. Upon IS formation by T and B lymphocytes with antigen-presenting cells (APC), the convergence of MVB towards the microtubule organization center (MTOC), and MTOC polarization to the IS, are involved in polarized exosome secretion at the synaptic cleft. This specialized mechanism provides the immune system with a finely-tuned strategy to increase the specificity and efficiency of crucial secretory effector functions of B and T lymphocytes. As inducible exosome secretion by antigen-receptors is a critical and unique feature of the immune system this review considers the study of the traffic events leading to polarized exosome secretion at the IS and some of their biological consequences.