Human Bone Mesenchymal Stem Cell-Derived Exosomes Inhibit IL-1β-Induced Inflammation in Osteoarthritis Chondrocytes

A call for standardization for secretome and extracellular vesicles in osteoarthritis: results show disease-modifying potential, but protocols are too heterogeneous-a systematic review

The currently available osteoarthritis (OA) treatments offer symptoms' relief without disease-modifying effects. Increasing evidence supports the role of human mesenchymal stem cells (MSCs) to drive beneficial effects provided by their secretome and extracellular vesicles (EVs), which includes trophic and biologically active factors. Aim of this study was to evaluate the in vitro literature to understand the potential of human secretome and EVs for OA treatment and identify trends, gaps, and potential translational challenges. A systematic review was performed on PubMed, Embase, and Web-of-Science, identifying 58 studies. The effects of secretome and EVs were analysed on osteoarthritic cells regarding anabolic, anti-apoptotic/anti-inflammatory and catabolic/pro-inflammatory/degenerative activity, chondroinduction, and immunomodulation. The results showed that MSC-derived EVs elicit an increase in proliferation and migration, reduction of cell death and inflammation, downregulation of catabolic pathways, regulation of immunomodulation, and promotion of anabolic processes in arthritic cells. However, a high heterogeneity in several technical or more applicative aspects emerged. In conclusion, the use of human secretome and EVs as strategy to address OA processes has overall positive effects and disease-modifying potential. However, it is crucial to reduce protocol variability and strive toward a higher standardization, which will be essential for the translation of this promising OA treatment from the in vitro research setting to the clinical practice.

Cinnamaldehyde-Treated Bone Marrow Mesenchymal-Stem-Cell-Derived Exosomes via Aqueous Two-Phase System Attenuate IL-1β-Induced Inflammation and Catabolism via Modulation of Proinflammatory Signaling Pathways

Osteoarthritis (OA) is a degenerative joint disorder that is distinguished by inflammation and chronic cartilage damage. Interleukin-1β (IL-1β) is a proinflammatory cytokine that plays an important role in the catabolic processes that underlie the pathogenesis of OA. In this study, we investigate the therapeutic efficacy of exosomes derived from untreated bone-marrow-derived mesenchymal stem cells (BMMSC-Exo) and those treated with cinnamaldehyde (BMMSC-CA-Exo) for preventing the in vitro catabolic effects of IL-1β on chondrocytes. We stimulated chondrocytes with IL-1β to mimic the inflammatory microenvironment of OA. We then treated these chondrocytes with BMMSC-Exo and BMMSC-CA-Exo isolated via an aqueous two-phase system and evaluated their effects on the key cellular processes using molecular techniques. Our findings revealed that treatment with BMMSC-Exo reduces the catabolic effects of IL-1β on chondrocytes and alleviates inflammation. However, further studies directly comparing treatments with BMMSC-Exo and BMMSC-CA-Exo are needed to determine if CA preconditioning can provide additional anti-inflammatory benefits to the exosomes beyond those of CA preconditioning or treatment with regular BMMSC-Exo. Through a comprehensive molecular analysis, we elucidated the regulatory mechanisms underlying this protective effect. We found a significant downregulation of proinflammatory signaling pathways in exosome-infected chondrocytes, suggesting the potential modulation of the NF-κB and MAPK signaling cascades. Furthermore, our study identified the molecular cargo of BMMSC-Exo and BMMSC-CA-Exo, determining the key molecules, such as anti-inflammatory cytokines and cartilage-associated factors, that may contribute to their acquisition of chondroprotective properties. In summary, BMMSC-Exo and BMMSC-CA-Exo exhibit the potential as therapeutic agents for OA by antagonizing the in vitro catabolic effects of IL-1β on chondrocytes. The regulation of the proinflammatory signaling pathways and bioactive molecules delivered by the exosomes suggests a multifaceted mechanism of action. These findings highlight the need for further investigation into exosome-based therapies for OA and joint-related diseases.

Exosomal noncoding RNA: A potential therapy for retinal vascular diseases

Exosomes are extracellular vesicles that can contain DNA, RNA, proteins, and metabolites. They are secreted by cells and play a regulatory role in various biological responses by mediating cell-to-cell communication. Moreover, exosomes are of interest in developing therapies for retinal vascular disorders because they can deliver various substances to cellular targets. According to recent research, exosomes can be used as a strategy for managing retinal vascular diseases, and they are being investigated for therapeutic purposes in eye conditions, including glaucoma, dry eye syndrome, retinal ischemia, diabetic retinopathy, and age-related macular degeneration. However, the role of exosomal noncoding RNA in retinal vascular diseases is not fully understood. Here, we reviewed the latest research on the biological role of exosomal noncoding RNA in treating retinal vascular diseases. Research has shown that noncoding RNAs, including microRNAs, circular RNAs, and long noncoding RNAs play a significant role in the regulation of retinal vascular diseases. Furthermore, through exosome engineering, the expression of relevant noncoding RNAs in exosomes can be controlled to regulate retinal vascular diseases. Therefore, this review suggests that exosomal noncoding RNA could be considered as a biomarker for diagnosis and as a therapeutic target for treating retinal vascular disease.

Human umbilical cord mesenchymal stem cells-derived exosomes exert anti-inflammatory effects on osteoarthritis chondrocytes

Inflammation of chondrocytes plays a critical role in the occurrence and development of osteoarthritis (OA). Recent evidence indicated exosomes derived from mesenchymal stem cells (MSCs-Exos) exhibit excellent anti-inflammatory ability in many troublesome inflammatory diseases including OA. In the present study, we aimed to explore the role of human umbilical cord-derived MSCs-Exos (hUC-MSCs-Exos) in treating the inflammation of chondrocytes and its related mechanisms. Ultracentrifugation was applied to isolate hUC-MSCs-Exos from the culture supernatant of hUC-MSCs. Two OA-like in vitro inflammation models of human articular chondrocytes induced with interleukin 1β (IL-1β) and co-incubation with macrophage utilizing transwell cell culture inserts were both used to evaluate the anti-inflammatory effects of hUC-MSCs-Exos. The mRNA sequencing of chondrocytes after treatment and microRNA (miRNA) sequencing of hUC-MSCs-Exos were detected and analyzed for possible mechanism analysis. The results of the study confirmed that hUC-MSCs-Exos had a reversed effect of IL-1β on chondrocytes in the expression of collagen type II alpha 1 (COL2A1) and matrix metalloproteinase 13 (MMP13). The addition of hUC-MSCs-Exos to M1 macrophages in the upper chamber showed down-regulation of IL-1β and tumor necrosis factor α (TNF-α), up-regulation of IL-10 and arginase1 (ARG1), and reversed the gene and protein expression of COL2A1 and MMP13 of the chondrocytes seeded in the lower chamber. The results of this study confirmed the anti-inflammatory effects of hUC-MSCs-Exos in the human articular chondrocytes inflammation model. hUC-MSCs-Exos may be used as a potential cell-free treatment strategy for chondrocyte inflammation in OA.

The emerging role of exosomes in innate immunity, diagnosis and therapy

Exosomes, which are nano-sized transport bio-vehicles, play a pivotal role in maintaining homeostasis by exchanging genetic or metabolic information between different cells. Exosomes can also play a vital role in transferring virulent factors between the host and parasite, thereby regulating host gene expression and the immune interphase. The association of inflammation with disease development and the potential of exosomes to enhance or mitigate inflammatory pathways support the notion that exosomes have the potential to alter the course of a disease. Clinical trials exploring the role of exosomes in cancer, osteoporosis, and renal, neurological, and pulmonary disorders are currently underway. Notably, the information available on the signatory efficacy of exosomes in immune-related disorders remains elusive and sporadic. In this review, we discuss immune cell-derived exosomes and their application in immunotherapy, including those against autoimmune connective tissue diseases. Further, we have elucidated our views on the major issues in immune-related pathophysiological processes. Therefore, the information presented in this review highlights the role of exosomes as promising strategies and clinical tools for immune regulation.

Bone Marrow Mesenchymal Stem Cell Exosome Attenuates Inflammasome-Related Pyroptosis via Delivering circ_003564 to Improve the Recovery of Spinal Cord Injury

Bone marrow mesenchymal stem cell (BMSC) is previously reported to present a certain effect on treating spinal cord injury (SCI), while the underlying mechanism is largely uncovered. Therefore, the current study aimed to investigate the involvement of exosome-delivered circRNA profile in the BMSC's effect on pyroptosis for SCI treatment. H₂O₂ treated rat primary neurons were cultured with normal medium, BMSC, BMSC plus GW4869, and BMSC-derived exosome, respectively, then inflammasome-related pyroptosis markers, and circRNA profiles were detected. Subsequently, circ_003564-knockdown BMSC exosome was transfected into H₂O₂ treated rat primary neurons and NGF-stimulated PC-12 cells. Furthermore, in vivo validation was conducted. BMSC and BMSC-derived exosome both decreased inflammasome-related pyroptosis markers including cleaved caspase-1, GSDMD, NLRP3, IL-1β, and IL-18 in H₂O₂-treated neurons, while exosome-free BMSC (BMSC plus GW4869) did not obviously reduce these factors. Microarray assay revealed that BMSC (vs. exosome-free BMSC) and BMSC-derived exosome (vs. normal medium) greatly regulated circRNA profiles, which were enriched in neuroinflammation pathways (such as neurotrophin, apoptosis, and TNF). Among three functional candidate circRNAs (circ_015525, circ_008876, and circ_003564), circ_003564 was most effective to regulate inflammasome-related pyroptosis. Interestingly, circ_003564-knockdown BMSC exosome showed higher expression of inflammasome-related pyroptosis markers compared to negative-control-knockdown BMSC exosome in H₂O₂ treated primary neurons/NGF-stimulated PC-12 cells. In vivo, BMSC exosome improved the function recovery and decreased tissue injury and inflammasome-related pyroptosis in SCI rats, whose effect was attenuated by circ_003564 knockdown transfection. BMSC exosome attenuates inflammasome-related pyroptosis via delivering circ_003564, contributing to its treatment efficacy for SCI.

Chondroprotective Effects of 4,5-Dicaffeoylquinic Acid in Osteoarthritis through NF-κB Signaling Inhibition

Osteoarthritis (OA) is characterized by cartilage degradation, inflammation, and pain. The dicaffeoylquinic acid (diCQA) isomer, 4,5-diCQA, exhibits antioxidant activity and various other health-promoting benefits, but its chondroprotective effects have yet to be elucidated. In this study, we aimed to investigate the chondroprotective effects of 4,5-diCQA on OA both in vitro and in vivo. Primary rat chondrocytes were pre-treated with 4,5-diCQA for 1 h before stimulation with interleukin (IL)-1β (5 ng/mL). The accumulation of nitrite, PGE₂, and aggrecan was observed using the Griess reagent and ELISA. The protein levels of iNOS, COX-2, MMP-3, MMP-13, ADMATS-4, MAPKs, and the NF-κB p65 subunit were measured by Western blotting. In vivo, the effects of 4,5-diCQA were evaluated for 2 weeks in a destabilization of the medial meniscus (DMM)-surgery-induced OA rat model. 4,5-diCQA significantly inhibited IL-1β-induced expression of nitrite, iNOS, PGE₂, COX-2, MMP-3, MMP-13, and ADAMTS-4. 4,5-diCQA also decreased the IL-1β-induced degradation of aggrecan. It also suppressed the IL-1β-induced phosphorylation of MAPKs and translocation of the NF-κB p65 subunit to the nucleus. These findings indicate that 4,5-diCQA inhibits DMM-surgery-induced cartilage destruction and proteoglycan loss in vivo. 4,5-diCQA may be a potential therapeutic agent for the alleviation of OA progression. In this study, diclofenac was set to be administered once every two days, but it showed an effect on OA. These results may be used as basic data to suggest a new dosing method for diclofenac.

A single step, centrifuge-free method to harvest bone marrow highly concentrated in mesenchymal stem cells: results of a pilot trial

PURPOSE

The aims of the present study were: (1) to characterize the bone-marrow aspirate (BMA) obtained with a centrifuge-free process, employing a dedicated aspiration device; (2) to test the in vitro efficacy of BMA in a model of cartilage inflammation; and (3) to report the preliminary clinical results in a small cohort of patients affected by knee OA.

METHODS

Ten patients (4 M, 6 W; mean age: 51.9 ± 9.2 yy) affected by mild to moderate unicompartmental knee OA (KL grade 2-3) were treated by intra-articular and subchondral injections of BMA obtained by a centrifuge-free process. To evaluate the effectiveness of the device in harvesting mesenchymal stem cells (MSCs), samples of the obtained BMA were tested by flow cytometry before and after subculture; BMA ability to counteract inflammation was also tested in an in vitro model of cartilage cell inflammation, evaluating the expression of MMP1, MMP3, TGFβ and TIMP-1 by real-time PCR. Patients were also evaluated up to two years' follow-up by using: VAS for pain, IKDC-subjective and KOOS scores.

RESULTS

The laboratory analysis showed that BMSCs accounted for 0.011% of BMA cells, similar to what had been expected in native bone marrow. The paracrine activity of BMA was able to reduce in vitro the catabolic response of human chondrocyte, as shown by the decrease in metalloproteases concentration and increase in anti-inflammatory mediators. Moreover, the clinical evaluation showed significant improvements in all scores adopted, with stable results up to two years.

CONCLUSION

The present data showed the effectiveness of the study device to harvest pure bone marrow with minimal peripheral blood contamination. The relevant content of MSCs resulted in the ability to counteract the catabolic cascade through a paracrine action. The clinical outcomes in patients affected by unicompartmental knee OA were encouraging in terms of pain reduction and functional improvement up to mid-term evaluation.