Engineered-extracellular vesicles as an optimistic tool for microRNA delivery for osteoarthritis treatment

Endothelial Extracellular Vesicles Enriched in microRNA-34a Predict New-Onset Diabetes in Coronavirus Disease 2019 (COVID-19) Patients: Novel Insights for Long COVID Metabolic Sequelae

Emerging evidence indicates that the relationship between coronavirus disease 2019 (COVID-19) and diabetes is 2-fold: 1) it is known that the presence of diabetes and other metabolic alterations poses a considerably high risk to develop a severe COVID-19; 2) patients who survived a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection have an increased risk of developing new-onset diabetes. However, the mechanisms underlying this association are mostly unknown, and there are no reliable biomarkers to predict the development of new-onset diabetes. In the present study, we demonstrate that a specific microRNA (miR-34a) contained in circulating extracellular vesicles released by endothelial cells reliably predicts the risk of developing new-onset diabetes in COVID-19. This association was independent of age, sex, body mass index (BMI), hypertension, dyslipidemia, smoking status, and D-dimer. SIGNIFICANCE STATEMENT: We demonstrate for the first time that a specific microRNA (miR-34a) contained in circulating extracellular vesicles released by endothelial cells is able to reliably predict the risk of developing diabetes after having contracted coronavirus disease 2019 (COVID-19). This association was independent of age, sex, body mass index (BMI), hypertension, dyslipidemia, smoking status, and D-dimer. Our findings are also relevant when considering the emerging importance of post-acute sequelae of COVID-19, with systemic manifestations observed even months after viral negativization (long COVID).

Co-culture engineering: a promising strategy for production of engineered extracellular vesicle for osteoarthritis treatment

The therapeutic effects of extracellular vesicles (EVs) have been identified as a significant factor in intercellular communication in different disease treatments, including osteoarthritis (OA). Compared to the conventional approaches in treating OA, EV therapy is a non-invasive and cell-free method. However, improving the yield of EVs and their therapeutic effects are the main challenges for clinical applications. In this regard, researchers are using the EV engineering potential to overcome these challenges. New findings suggest that the co-culture strategy as an indirect EV engineering method efficiently increases EV production and quality. The co-culture of mesenchymal stem cells (MSCs) and chondrocytes has improved their chondrogenesis, anti-inflammatory effects, and regenerative properties which are mediated by EVs. Hence, co-culture engineering by considerable systems could be useful in producing engineered EVs for different therapeutic applications. Here, we review various co-culture approaches, including diverse direct and indirect, 2D and 3D cell cultures, as well as static and dynamic systems. Meanwhile, we suggest and discuss the advantages of combined strategies to achieve engineered EVs for OA treatment.

Nanomaterial-based drug delivery of immunomodulatory factors for bone and cartilage tissue engineering

As life expectancy continues to increase, so do disorders related to the musculoskeletal system. Orthopedics-related impairments remain a challenge, with nearly 325 thousand and 120 thousand deaths recorded in 2019. Musculoskeletal system, including bone and cartilage tissue, is a living system in which cells constantly interact with the immune system, which plays a key role in the tissue repair process. An alternative to bridge the gap between these two systems is exploiting nanomaterials, as they have proven to serve as delivery agents of an array of molecules, including immunomodulatory agents (anti-inflammatory drugs, cytokines), as well as having the ability to mimic tissue by their nanoscopic structure and promote tissue repair per se. Therefore, this review outlooks nanomaterials and immunomodulatory factors widely employed in the area of bone and cartilage tissue engineering. Emerging developments in nanomaterials for delivery of immunomodulatory agents for bone and cartilage tissue engineering applications have also been discussed. It can be concluded that latest progress in nanotechnology have enabled to design intricate systems with the ability to deliver biologically active agents, promoting tissue repair and regeneration; thus, nanomaterials studied herein have shown great potential to serve as immunomodulatory agents in the area of tissue engineering.

Immunomodulatory potential of mesenchymal stromal cell-derived extracellular vesicles in chondrocyte inflammation

Introduction

Osteoarthritis (OA) affects a large percentage of the population worldwide. Current surgical and nonsurgical concepts for treating OA only result in symptom-modifying effects. However, there is no disease-modifying therapy available. Extracellular vesicles released by mesenchymal stem/stromal cells (MSC-EV) are promising agents to positively influence joint homeostasis in the osteoarthritic surroundings. This pilot study aimed to investigate the effect of characterized MSC-EVs on chondrogenesis in a 3D chondrocyte inflammation model with the pro-inflammatory cytokine TNFα.

Methods

Bovine articular chondrocytes were expanded and transferred into pellet culture at passage 3. TNFα, human MSC-EV preparations (MSC-EV batches 41.5-EVi1 and 84-EVi), EVs from human platelet lysate (hPL4-EV), or the combination of TNFα and EVs were supplemented. To assess the effect of MSC-EVs in the chondrocyte inflammation model after 14 days, DNA, glycosaminoglycan (GAG), total collagen, IL-6, and NO release were quantified, and gene expression of anabolic (COL-II, aggrecan, COMP, and PRG-4), catabolic (MMP-3, MMP-13, ADAMTS-4 and ADAMTS-5), dedifferentiation (COL-I), hypertrophy (COL-X, VEGF), and inflammatory (IL-8) markers were analyzed; histological evaluation was performed using safranin O/Fast Green staining and immunohistochemistry of COL I and II. For statistical evaluation, nonparametric tests were chosen with a significance level of p < 0.05.

Results

TNFα supplementation resulted in catabolic stimulation with increased levels of NO and IL-6, upregulation of catabolic gene expression, and downregulation of anabolic markers. These findings were supported by a decrease in matrix differentiation (COL-II). Supplementation of EVs resulted in an upregulation of the chondrogenic marker PRG-4. All MSC-EV preparations significantly increased GAG retention per pellet. In contrast, catabolic markers and IL-8 expression were upregulated by 41.5-EVi1. Regarding protein levels, IL-6 and NO release were increased by 41.5-EVi1. Histologic and immunohistochemical evaluations indicated a higher differentiation potential of chondrocytes treated with 84-EVi.

Discussion

MSC-EVs can positively influence chondrocyte matrix production in pro-inflammatory surroundings, but can also stimulate inflammation. In this study MSC-EV 41.5-EVi1 supplementation increased chondrocyte inflammation, whereas MSC-84-EVi supplementation resulted a higher chondrogenic potential of chondrocytes in 3D pellet culture. In summary, the selected MSC-EVs exhibited promising chondrogenic effects indicating their significant potential for the treatment of OA; however, the functional heterogeneity in MSC-EV preparations has to be solved.

Engineered extracellular vesicles as therapeutics of degenerative orthopedic diseases

Degenerative orthopedic diseases, as a global public health problem, have made serious negative impact on patients' quality of life and socio-economic burden. Traditional treatments, including chemical drugs and surgical treatments, have obvious side effects and unsatisfactory efficacy. Therefore, biological therapy has become the focus of researches on degenerative orthopedic diseases. Extracellular vesicles (EVs), with superior properties of immunoregulatory, growth support, and drug delivery capabilities, have emerged as a new cell-free strategy for the treatment of many diseases, including degenerative orthopedic diseases. An increasing number of studies have shown that EVs can be engineered through cargo loading, surface modification, and chemical synthesis to improve efficiency, specificity, and safety. Herein, a comprehensive overview of recent advances in engineering strategies and applications of engineered EVs as well as related researches in degenerative orthopedic diseases, including osteoarthritis (OA), osteoporosis (OP), intervertebral disc degeneration (IDD) and osteonecrosis of the femoral head (ONFH), is provided. In addition, we analyze the potential and challenges of applying engineered EVs to clinical practice.

Role of M2 macrophages-derived extracellular vesicles in IL-1β-stimulated chondrocyte proliferation and inflammatory responses

M2 macrophages-derived extracellular vesicles (M2-EVs) serve as a tool for the delivery of miRNAs and play an anti-inflammatory role in diseases. This study sought to explore the role of (M2-EVs) in the proliferation and inflammatory responses of IL-1β-stimulated chondrocytes. M2 macrophages were induced and characterized, followed by isolation and characterization of M2-EVs. Chondrocytes were treated with 10 ng/mL IL-1β and co-cultured with M2 macrophages transfected with Cy3-labeled miR-370-3p. Cell viability, TNF (tumor necrosis factor)-α, IL(Interleukin)-18, IL-10, miR-370-3p, and sex-determining region Y-related high-mobility-group box transcription factor 11 (SOX11) mRNA were determined via cell counting assay kit, colony formation, ELISA, and qRT-PCR. The binding relationship between miR-370-3p and SOX11 was testified via the dual-luciferase assay. The functional rescue experiment was designed to confirm the role of SOX11. M2-EVs improved chondrocyte viability and colony formation, lowered TNF-α and IL-18, and elevated IL-10. M2-EVs delivered miR-370-3p into chondrocytes to upregulate miR-370-3p. Upregulation of miR-370-3p in M2-EVs enhanced the protective role of M2-EVs in chondrocytes. miR-370-3p inhibited SOX11 transcription. SOX11 overexpression attenuated the protective role of M2-EVs in chondrocytes. Overall, our findings suggested that M2-EVs promote proliferation and suppress inflammatory responses in IL-1β-stimulated chondrocytes via the miR-370-3p/SOX11 axis.

The potential use of mesenchymal stem cells-derived exosomes as microRNAs delivery systems in different diseases

MicroRNAs (miRNAs) are a group of small non-coding RNAs that regulate gene expression by targeting mRNA. Moreover, it has been shown that miRNAs expression are changed in various diseases, such as cancers, autoimmune disease, infectious diseases, and neurodegenerative Diseases. The suppression of miRNA function can be easily attained by utilizing of anti-miRNAs. In contrast, an enhancement in miRNA function can be achieved through the utilization of modified miRNA mimetics. The discovery of appropriate miRNA carriers in the body has become an interesting subject for investigators. Exosomes (EXOs) therapeutic efficiency and safety for transferring different cellular biological components to the recipient cell have attracted significant attention for their capability as miRNA carriers. Mesenchymal stem cells (MSCs) are recognized to generate a wide range of EXOs (MSC-EXOs), showing that MSCs may be effective for EXO generation in a clinically appropriate measure as compared to other cell origins. MSC-EXOs have been widely investigated because of their immune attributes, tumor-homing attributes, and flexible characteristics. In this article, we summarized the features of miRNAs and MSC-EXOs, including production, purification, and miRNA loading methods of MSC-EXOs, and the modification of MSC-EXOs for targeted miRNA delivery in various diseases. Video abstract.

Co-aggregation of MSC/chondrocyte in a dynamic 3D culture elevates the therapeutic effect of secreted extracellular vesicles on osteoarthritis in a rat model

Extracellular vesicles (EVs) have therapeutic effects on osteoarthritis (OA). Some recent strategies could elevate EV's therapeutic properties including cell aggregation, co-culture, and 3D culture. It seems that a combination of these strategies could augment EV production and therapeutic potential. The current study aims to evaluate the quantity of EV yield and the therapeutic effect of EVs harvested from rabbit mesenchymal stem cells (MSCs) aggregates, chondrocyte aggregates, and their co-aggregates in a dynamic 3D culture in a rat osteoarthritis model. MSC and chondrocytes were aggregated and co-aggregated by spinner flasks, and their conditioned medium was collected. EVs were isolated by size exclusion chromatography and characterized in terms of size, morphology and surface markers. The chondrogenic potential of the MSC-ag, Cho-ag and Co-ag EVs on MSC micromass differentiation in chondrogenic media were assessed by qRT-PCR, histological and immunohistochemical analysis. 50 μg of MSC-ag-EVs, Cho-ag-EVs and Co-ag-EVs was injected intra-articularly per knee of OA models established by monoiodoacetate in rats. After 8 weeks follow up, the knee joints were harvested and analyzed by radiographic, histological and immunohistochemical features. MSC/chondrocyte co-aggregation in comparison to MSC or chondrocyte aggregation could increase EV yield during dynamic 3D culture by spinner flasks. Although MSC-ag-, Cho-ag- and Co-ag-derived EVs could induce chondrogenesis similar to transforming growth factor-beta during in vitro study, Co-ag-EV could more effectively prevent OA progression than MSC-ag- and Cho-ag-EVs. Our study demonstrated that EVs harvested from the co-aggregation of MSCs and chondrocytes could be considered as a new therapeutic potential for OA treatment.

Breakthrough of extracellular vesicles in pathogenesis, diagnosis and treatment of osteoarthritis

Osteoarthritis (OA) is a highly prevalent whole-joint disease that causes disability and pain and affects a patient's quality of life. However, currently, there is a lack of effective early diagnosis and treatment. Although stem cells can promote cartilage repair and treat OA, problems such as immune rejection and tumorigenicity persist. Extracellular vesicles (EVs) can transmit genetic information from donor cells and mediate intercellular communication, which is considered a functional paracrine factor of stem cells. Increasing evidences suggest that EVs may play an essential and complex role in the pathogenesis, diagnosis, and treatment of OA. Here, we introduced the role of EVs in OA progression by influencing inflammation, metabolism, and aging. Next, we discussed EVs from the blood, synovial fluid, and joint-related cells for diagnosis. Moreover, we outlined the potential of modified and unmodified EVs and their combination with biomaterials for OA therapy. Finally, we discuss the deficiencies and put forward the prospects and challenges related to the application of EVs in the field of OA.

Current understanding of MSC-derived exosomes in the management of knee osteoarthritis

Mesenchymal stem cell-derived exosomes (MSC-Exos) have been utilized as medicinal agents or as delivery vehicles in cartilage injuries and cartilage-based diseases. Given the ongoing emergence of evidence on the effector mechanisms and methods of the utility of the MSC-Exos in knee osteoarthritis, a comprehensive review of the current evidence is the need of the hour. Hence, in this article, we review the current understanding of the role of MSC-Exos in the management of knee osteoarthritis in view of their classification, characterization, biogenesis, mechanism of action, pathways involved in their therapeutic action, in-vitro evidence on cartilage regeneration, in-vivo evidence in OA knee models and recent advances in using MSC-Exos to better streamline future research from bench to bedside for OA knee.

Extracellular Vesicle-Mediated miR-150-3p Delivery in Joint Homeostasis: A Potential Treatment for Osteoarthritis?

Background: The disruption of joint homeostasis is a critical event during the process of joint injury in osteoarthritis (OA). As regulatory molecules, microRNAs (miRNAs) can be released from secretory cells and delivered to recipient cells through extracellular vesicles (EVs), thereby playing an important role in regulating joint homeostasis. We hypothesized that the fibroblast-like synoviocytes (FLSs) in healthy joints could release EVs enriched in miRNAs that can maintain joint homeostasis by regulating the signal transduction pathways in the joints, whereby the articular cartilage (AC) is protected from degeneration, and OA progression is delayed. Methods: Via high-throughput sequencing and qPCR, we found that miR-150-3p was enriched in the circulating EVs in healthy rats. Next, we established an in vitro cell model in which chondrocytes were cultured with (i) FLSs transfected with miR-150-3p mimics or (ii) EVs released by FLSs (FLS–EVs) inside the healthy synovial membrane (SM). The transportation mechanism from FLSs to chondrocytes was studied using the EV inhibitor GW4869, and the FLSs were transfected with a miR-150-3p mimic or inhibitor. To assess the therapeutic effect of miR-150-3p-carrying EVs (EVs-150) in vivo, healthy FLS-derived EVs (H-FLS–EVs) were injected into the tail vein of rats with OA at various stages of the pathogenesis and evaluated for the progression of OA. Results: The chondrocytes could uptake fluorescent-labeled miR-150-3p mimics and FLS–EVs, and GW4869 suppressed this uptake. The overexpression of miR-150-3p could significantly reduce the concentrations of pro-inflammatory cytokines in the cell culture medium and the expression of the miR-150-3p target T cell receptor-interacting molecule 14 (Trim14), as well as the innate immune-related factors, including nuclear factor kappa B (NF-κB) and interferon-β (IFN-β). Similarly to the in vitro findings, the miR-150-3p level in the serum EVs was significantly upregulated among the EV-treated rats. In the AC of the OA rat model injected with H-FLS–EVs, the joint degeneration was suppressed, and Type II collagen (COLII) and aggrecan (ACAN) were significantly upregulated, whereas the innate immune-related factors Trim14, NF-κB, and IFN-β were downregulated compared with the levels in the untreated OA rats. Notably, the suppression of joint degeneration was more significant when H-FLS–EVs were administered at the early stages of OA rather than the late stages. Conclusion: H-FLS–EVs protect chondrocyte function and maintain joint homeostasis by modulating the innate immune response by suppressing the Trim14/NF-κB/IFNβ axis. These effects are achieved through the EV-mediated transport of miR-150-3p from the FLSs to the chondrocytes. Our findings show that EV-mediated miR-150-3p can be used to suppress OA, thus providing a novel therapeutic strategy. Additionally, the EV-mediated miR-150-3p transport may also serve as a potential biomarker in the diagnosis, treatment, and prognosis of OA.

miR-3960 from Mesenchymal Stem Cell-Derived Extracellular Vesicles Inactivates SDC1/Wnt/β-Catenin Axis to Relieve Chondrocyte Injury in Osteoarthritis by Targeting PHLDA2

Osteoarthritis (OA) is a serious disease of the articular cartilage characterized by excessive inflammation. Lately, mesenchymal stem cell- (MSC-) derived extracellular vesicles (EVs) have been proposed as a novel strategy for the treatment of OA. We aimed to investigate the effects of EV-encapsulated miR-3960 derived from MSCs on chondrocyte injury in OA. The cartilage tissues from OA patients were collected to experimentally determine expression patterns of miR-3960, PHLDA2, SDC1, and β-catenin. Next, luciferase assay was implemented to testify the binding affinity among miR-3960 and PHLDA2. EVs were isolated from MSCs and cocultured with IL-1β-induced OA chondrocytes. Afterwards, cellular biological behaviors and levels of extracellular matrix- (ECM-) related protein anabolic markers (collagen II and aggrecan), catabolic markers (MMP13 and ADAMTS5), and inflammatory factors (IL-6 and TNF-α) in chondrocytes were assayed upon miR-3960 and/or PHLDA2 gain- or loss-of-function. Finally, the effects of miR-3960 contained in MSC-derived EVs in OA mouse models were also explored. MSCs-EVs could reduce IL-1β-induced inflammatory response and extracellular matrix (ECM) degradation in chondrocytes. miR-3960 expression was downregulated in cartilage tissues of OA patients but enriched in MSC-derived EVs. miR-3960 could target and inhibit PHLDA2, which was positively correlated with SDC1 and Wnt/β-catenin pathway activation. miR-3960 shuttled by MSC-derived EVs protected against apoptosis and ECM degradation in chondrocytes. In vivo experiment also confirmed that miR-3960 alleviated chondrocyte injury in OA. Collectively, MSC-derived EV-loaded miR-3960 downregulated PHLDA2 to inhibit chondrocyte injury via SDC1/Wnt/β-catenin.

Human Umbilical Cord Mesenchymal Stem Cell-Derived Extracellular Vesicles Carrying MicroRNA-181c-5p Promote BMP2-Induced Repair of Cartilage Injury through Inhibition of SMAD7 Expression

The therapy role of mesenchymal stem cell- (MSC-) derived extracellular vesicles (EVs) in cartilage regeneration has been well studied. Herein, we tried to analyze the role of human umbilical cord MSC- (hUCMSC-) EVs carrying microRNA- (miR-) 181c-5p in repair of cartilage injury. After successful isolation of hUCMSCs, the multidirectional differentiation abilities were analyzed. Then, the EVs were isolated and identified. After coculture of PKH26-labled EVs with bone marrow MSCs (BMSCs), the biological behaviors of which were detected. The relationship between the predicted early posttraumatic osteoarthritis-associated miRNA, miR-181c-5p, and SMAD7 was verified. Gain- and loss-of functions were performed for investing the role of miR-181c-5p and SMAD7 in BMP-induced chondrogenesis in vitro and in vivo. hUCMSC-EVs could be internalized by BMSCs and promote the proliferative, migratory, and chondrogenic differentiation potentials of BMSCs. Additionally, miR-181c-5p could target and inhibit SMAD7 expression to promote the bone morphogenic protein 2- (BMP2-) induced proliferative, migratory, and chondrogenic differentiation potentials of BMSCs. Also, overexpression of SMAD7 inhibited the repairing effect of BMP2, and overexpression of BMP2 and miR-181c-5p further promoted the repair of cartilage injury in vivo. Our present study highlighted the repairing effect of hUCMSC-EVs carrying miR-181c-5p on cartilage injury.

The Application of Extracellular Vesicles Mediated miRNAs in Osteoarthritis: Current Knowledge and Perspective

Osteoarthritis (OA) is a whole joint disease characterized by synovitis, cartilage destruction, and subchondral bone sclerosis and cyst. Despite decades’ study, effective treatment is rare for this chronic disease. Extracellular vesicles (EVs), including exosomes, microvesicles, and apoptosis bodies, are nano-sized vesicles with a cargo containing biologically active agents, such as nucleic acids, lipids, and proteins. As a group of short non-coding RNAs, microRNAs (miRNAs) can be delivered by parental cells secreted EVs. Negatively regulate the target mRNAs at the posttranscriptional level and regulate gene expression in recipient cells without modifying gene sequence. Recently, most studies focused on the function of EVs mediated miRNAs in the pathophysiological process of OA. However, all kinds of EVs specific and OA specific factors might influence the administration of EVs-miRNAs, especially the precise quantitative management. As a result, the flourishing of current research about EVs in the laboratory might not promote the relevant clinical transformation in OA treatment. In this review, we reviewed the present application of EVs-miRNAs in the therapeutic of OA and further analyzed the potential factors that might influence its application. Further progress in the quantitative management of EVs-miRNAs would accelerate the clinical transformation of miRNAs enriched EVs in the OA field.

[Application of tetrahedral framework nucleic acids in the treatment of osteoarthritis]

OBJECTIVE

To introduce the characteristics of tetrahedral framework nucleic acids (tFNA), focusing on its application in the treatment of osteoarthritis (OA) and relationship with microRNA (miRNA), and prospect the application of tFNA in the treatment of OA and the new idea of constructing miR-tFNA functional complex to treat OA.

METHODS

Recent studies were extensively reviewed to analyze the mechanism of tFNA and its relationship with OA and miRNA.

RESULTS

tFNA, a new type of new carrier, can not only play an indirect role in the treatment of OA as a small molecular carrier with therapeutic effect, but also play a direct role through the regulation of chondrocytes. It can bind with the miRNA that can regulate OA. The therapeutic effect of constructing tFNA functional complex loaded with miRNA has been verified in various diseases, and tFNA has advantages compared with other vectors.

CONCLUSION

tFNA, a novel framework nucleic acid structure, plays an important role in the treatment of OA. Constructing miR-tFNA functional complex may be an innovative idea in the treatment of OA.

Engineering strategies for customizing extracellular vesicle uptake in a therapeutic context

Extracellular vesicles (EVs) are advanced therapeutic strategies that can be used to efficiently treat diseases. Promising features of EVs include their innate therapeutic properties and ability to be engineered as targeted drug delivery systems. However, regulation of EV uptake is one challenge of EV therapy that must be overcome to achieve an efficient therapeutic outcome. Numerous efforts to improve the factors that affect EV uptake include the selection of a cell source, cell cultivation procedure, extraction and purification methods, storage, and administration routes. Limitations of rapid clearance, targeted delivery, and off-targeting of EVs are current challenges that must be circumvented. EV engineering can potentially overcome these limitations and provide an ideal therapeutic use for EVs. In this paper, we intend to discuss traditional strategies and their limitations, and then review recent advances in EV engineering that can be used to customize and control EV uptake for future clinical applications.

Higher Chondrogenic Potential of Extracellular Vesicles Derived from Mesenchymal Stem Cells Compared to Chondrocytes-EVs In Vitro

The inability of cartilage to self-repair necessitates an effective therapeutic approach to restore damaged tissues. Extracellular vesicles (EVs) are attractive options because of their roles in cellular communication and tissue repair where they regulate the cellular processes of proliferation, differentiation, and recruitment. However, it is a challenge to determine the relevant cell sources for isolation of EVs with high chondrogenic potential. The current study aims to evaluate the chondrogenic potential of EVs derived from chondrocytes (Cho-EV) and mesenchymal stem cells (MSC-EV). The EVs were separately isolated from conditioned media of both rabbit bone marrow MSCs and chondrocyte cultures. The isolated vesicles were assessed in terms of size, morphology, and surface marker expression. The chondrogenic potential of MSCs in the presence of different concentrations of EVs (50, 100, and 150 μg/ml) was evaluated during 21 days, and chondrogenic surface marker expressions were checked by qRT-PCR and histologic assays. The extracted vesicles had a spherical morphology and a size of 44.25 ± 8.89 nm for Cho-EVs and 112.1 ± 10.10 nm for MSC-EVs. Both groups expressed the EV-specific surface markers CD9 and CD81. Higher expression of chondrogenic specified markers, especially collagen type II (COL II), and secretion of glycosaminoglycans (GAGs) and proteoglycans were observed in MSCs treated with 50 and 100 μg/ml MSC-EVs compared to the Cho-EVs. The results from the use of EVs, particularly MSC-EVs, with high chondrogenic ability will provide a basis for developing therapeutic agents for cartilage repair.

Extracellular Vesicles Allow Epigenetic Mechanotransduction between Chondrocytes and Osteoblasts

MicroRNAs (miRNAs) can be transported in extracellular vesicles (EVs) and are qualified as possible messengers for cell–cell communication. In the context of osteoarthritis (OA), miR-221-3p has been shown to have a mechanosensitive and a paracrine function inside cartilage. However, the question remains if EVs with miR-221-3p can act as molecular mechanotransducers between cells of different tissues. Here, we studied the effect of EV-mediated transport in the communication between chondrocytes and osteoblasts in vitro in a rat model. In silico analysis (Targetscan, miRWalk, miRDB) revealed putative targets of miRNA-221-3p (CDKN1B/p27, TIMP-3, Tcf7l2/TCF4, ARNT). Indeed, transfection of miRNA-221-3p in chondrocytes and osteoblasts resulted in regulation of these targets. Coculture experiments of transfected chondrocytes with untransfected osteoblasts not only showed regulation of these target genes in osteoblasts but also inhibition of their bone formation capacity. Direct treatment with chondrocyte-derived EVs validated that chondrocyte-produced extracellular miR-221-3p was responsible for this effect. Altogether, our study provides a novel perspective on a possible communication pathway of a mechanically induced epigenetic signal through EVs. This may be important for processes at the interface of bone and cartilage, such as OA development, physiologic joint homeostasis, growth or fracture healing, as well as for other tissue interfaces with differing biomechanical properties.

Engineered neutrophil apoptotic bodies ameliorate myocardial infarction by promoting macrophage efferocytosis and inflammation resolution

Inflammatory response plays a critical role in myocardial infarction (MI) repair. The neutrophil apoptosis and subsequent macrophage ingestion can result in inflammation resolution and initiate regeneration, while the therapeutic strategy that simulates and enhances this natural process has not been established. Here, we constructed engineered neutrophil apoptotic bodies (eNABs) to simulate natural neutrophil apoptosis, which regulated inflammation response and enhanced MI repair. The eNABs were fabricated by combining natural neutrophil apoptotic body membrane which has excellent inflammation-tropism and immunoregulatory properties, and mesoporous silica nanoparticles loaded with hexyl 5-aminolevulinate hydrochloride (HAL). The eNABs actively targeted to macrophages and the encapsulated HAL simultaneously initiated the biosynthesis pathway of heme to produce anti-inflammatory bilirubin after intracellular release, thereby further enhancing the anti-inflammation effects. In in vivo studies, the eNABs efficiently modulated inflammation responses in the infarcted region to ameliorate cardiac function. This study demonstrates an effective biomimetic construction strategy to regulate macrophage functions for MI repair.

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Construction of engineered neutrophil apoptotic bodies to simulate natural neutrophil apoptosis.

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Engineered neutrophil apoptotic bodies with excellent inflammation-tropism and macrophage-specific targeting capacity.

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Engineered neutrophil apoptotic bodies enhance macrophage efferocytosis and reprogramming for inflammation resolution.

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Engineered neutrophil apoptotic bodies ameliorate myocardial infarction and promote cardiac tissue regeneration after MI.

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.

The non-coding RNA interactome in joint health and disease

Non-coding RNAs have distinct regulatory roles in the pathogenesis of joint diseases including osteoarthritis (OA) and rheumatoid arthritis (RA). As the amount of high-throughput profiling studies and mechanistic investigations of microRNAs, long non-coding RNAs and circular RNAs in joint tissues and biofluids has increased, data have emerged that suggest complex interactions among non-coding RNAs that are often overlooked as critical regulators of gene expression. Identifying these non-coding RNAs and their interactions is useful for understanding both joint health and disease. Non-coding RNAs regulate signalling pathways and biological processes that are important for normal joint development but, when dysregulated, can contribute to disease. The specific expression profiles of non-coding RNAs in various disease states support their roles as promising candidate biomarkers, mediators of pathogenic mechanisms and potential therapeutic targets. This Review synthesizes literature published in the past 2 years on the role of non-coding RNAs in OA and RA with a focus on inflammation, cell death, cell proliferation and extracellular matrix dysregulation. Research to date makes it apparent that 'non-coding' does not mean 'non-essential' and that non-coding RNAs are important parts of a complex interactome that underlies OA and RA.

Mesenchymal Stem Cell-Derived Extracellular Vesicles for Osteoarthritis Treatment: Extracellular Matrix Protection, Chondrocyte and Osteocyte Physiology, Pain and Inflammation Management

Osteoarthritis (OA) is a common degenerative disease that can lead to persistent pain and motion restriction. In the last decade, stem cells, particularly mesenchymal stem cells (MSCs), have been explored as a potential alternative OA therapy due to their regenerative capacity. Furthermore, it has been shown that trophic factors enveloped in extracellular vesicles (EVs), including exosomes, are a crucial aspect of MSC-based treatment for OA. Evidently, EVs derived from different MSC sources might rescue the OA phenotype by targeting many biological processes associated with cartilage extracellular matrix (ECM) degradation and exerting protective effects on different joint cell types. Despite this advancement, different studies employing EV treatment for OA have revealed reverse outcomes depending on the EV cargo, cell source, and pathological condition. Hence, in this review, we aim to summarize and discuss the possible effects of MSC-derived EVs based on recent findings at different stages of OA development, including effects on cartilage ECM, chondrocyte biology, osteocytes and bone homeostasis, inflammation, and pain management. Additionally, we discuss further strategies and technical advances for manipulating EVs to specifically target OA to bring the therapy closer to clinical use.

IFITM1 expression determines extracellular vesicle uptake in colorectal cancer

The majority of colorectal cancer (CRC) patients carry mutations in the APC gene, which lead to the unregulated activation of the Wnt pathway. Extracellular vesicles (EV) are considered potential therapeutic tools. Although CRC is a genetically heterogeneous disease, the significance of the intra-tumor heterogeneity in EV uptake of CRC cells is not yet known. By using mouse and patient-derived organoids, the currently available best model of capturing cellular heterogeneity, we found that Apc mutation induced the expression of interferon-induced transmembrane protein 1 (Ifitm1), a membrane protein that plays a major role in cellular antiviral responses. Importantly, organoids derived from IFITM1^high CRC cells contained more proliferating cells and they had a markedly reduced uptake of fibroblast EVs as compared to IFITM1^low/- cells. In contrast, there was no difference in the intensity of EV release between CRC subpopulations with high and low IFITM1 levels. Importantly, the difference in cell proliferation between these two subpopulations disappeared in the presence of fibroblast-derived EVs, proving the functional relevance of the enhanced EV uptake by IFITM1^low CRC cells. Furthermore, inactivating IFITM1 resulted in an enhanced EV uptake, highlighting the importance of this molecule in establishing the cellular difference for EV effects. Collectively, we identified CRC cells with functional difference in their EV uptake ability that must be taken into consideration when using EVs as therapeutic tools for targeting cancer cells.

Extracellular vesicles derived from mesenchymal stromal cells mediate endogenous cell growth and migration via the CXCL5 and CXCL6/CXCR2 axes and repair menisci

Background

Mesenchymal stromal cell-derived extracellular vesicles (MSC-EVs) are promising candidates for tissue regeneration therapy. However, the therapeutic efficacy of MSC-EVs for meniscus regeneration is uncertain, and the mechanisms underlying MSC-EV-mediated tissue regeneration have not been fully elucidated. The aims of this study were to evaluate the therapeutic efficacy of intra-articular MSC-EV injection in a meniscus defect model and elucidate the mechanism underlying MSC-EV-mediated tissue regeneration via combined bioinformatic analyses.

Methods

MSC-EVs were isolated from human synovial MSC culture supernatants via ultrafiltration. To evaluate the meniscus regeneration ability, MSC-EVs were injected intra-articularly in the mouse meniscus defect model immediately after meniscus resection and weekly thereafter. After 1 and 3 weeks, their knees were excised for histological and immunohistochemical evaluations. To investigate the mechanisms through which MSC-EVs accelerate meniscus regeneration, cell growth, migration, and chondrogenesis assays were performed using treated and untreated chondrocytes and synovial MSCs with or without MSC-EVs. RNA sequencing assessed the gene expression profile of chondrocytes stimulated by MSC-EVs. Antagonists of the human chemokine CXCR2 receptor (SB265610) were used to determine the role of CXCR2 on chondrocyte cell growth and migration induced by MSC-EVs.

Results

In the meniscus defect model, MSC-EV injection accelerated meniscus regeneration and normalized the morphology and composition of the repaired tissue. MSC-EVs stimulated chondrocyte and synovial MSC cell growth and migration. RNA sequencing revealed that MSC-EVs induced 168 differentially expressed genes in the chondrocytes and significantly upregulated CXCL5 and CXCL6 in chondrocytes and synovial MSCs. Suppression of CXCL5 and CXCL6 and antagonism of the CXCR2 receptor binding CXCL5 and CXCL6 negated the influence of MSC-EVs on chondrocyte cell growth and migration.

Conclusions

Intra-articular MSC-EV administration repaired meniscus defects and augmented chondrocyte and synovial MSC cell growth and migration. Comprehensive transcriptome/RNA sequencing data confirmed that MSC-EVs upregulated CXCL5 and CXCL6 in chondrocytes and mediated the cell growth and migration of these cells via the CXCR2 axis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02481-9.

Efficacy of extracellular vesicles from mesenchymal stem cells on osteoarthritis in animal models: a systematic review and meta-analysis

Background: Some studies have reported results from the use of mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) to treat osteoarthritis (OA). Objective: To evaluate the efficacy of MSC-EVs as a treatment for OA. Data sources: Databases were searched using the terms 'mesenchymal stem cells', 'osteoarthritis' and 'extracellular vesicles.' Study eligibility criteria: Studies performed in animal models utilizing MSC-EVs to treat OA that described the macroscopic evaluation or histological evaluation were included. Study appraisal: The quality of the studies was examined using the CAMARADES quality checklist. Results: MSC-EVs were superior to the placebo in the macroscopic evaluation and histological evaluation. MSC-EVs were more effective in the early stage of OA and once a week was better than multiple times a week. Limitations: The included studies were highly heterogeneous. Conclusion: MSC-EVs may improve the results of macroscopic and histological evaluations of OA.