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OBJECTIVE@#To assess the efficacy of GelMA hydrogel loaded with bone marrow stem cell-derived exosomes for repairing injured rat knee articular cartilage.@*METHODS@#The supernatant of cultured bone marrow stem cells was subjected to ultracentrifugation separate and extract the exosomes, which were characterized by transmission electron microscopy, particle size analysis and Western blotting of the surface markers. The changes in rheology and electron microscopic features of GelMA hydrogel were examined after loading the exosomes. We assessed exosome release from the hydrogel was detected by BCA protein detection method, and labeled the exosomes with PKH26 red fluorescent dye to observe their phagocytosis by RAW264.7 cells. The effects of the exosomes alone, unloaded hydrogel, and exosome-loaded hydrogel on the polarization of RAW264.7 cells were detected by q-PCR and immunofluorescence assay. We further tested the effect of the exosome-loaded hydrogel on cartilage repair in a Transwell co-culture cell model of RAW264.7 cells and chondrocytes in a rat model of knee cartilage injury using q-PCR and immunofluorescence assay and HE and Masson staining.@*RESULTS@#GelMA hydrogel loaded with exosomes significantly promoted M2-type polarization of RAW264.7 cells (P < 0.05). In the Transwell co-culture model, the exosome-loaded GelMA hydrogel significantly promoted the repair of injured chondrocytes by regulating RAW264.7 cell transformation from M1 to M2 (P < 0.05). HE and Masson staining showed that the exosome-loaded hydrogel obviously promoted cartilage repair in the rat models damage.@*CONCLUSION@#GelMA hydrogel loaded with bone marrow stem cell-derived exosomes can significantly promote the repair of cartilage damage in rats by improving the immune microenvironment.
Subject(s)
Animals , Rats , Bone Marrow Cells , Cartilage , Chondrocytes , Exosomes , Hydrogels/metabolismABSTRACT
Background:Cartilage oligomeric matrix protein (COMP), is an extracellular matrix (ECM) non-collagenous glycoprotein that is mainly localized within the cartilage, and also be found in tendon and synovium.RecentstudiesinwestandAsiaPacificregionhasshownthatCOMP, is a prognostic marker in Rheumatoid arthritis(RA).Objective:To correlate serum COMP levels with disease severity and cartilage destruction in rheumatoid arthritis.Methods:The study was conducted in Department of Pathology and Rheumatology, Ziauddin University Hospital, Karachi from June 2018 to May 2019. Patients were recruited as per American College of Rheumatology (ACR) 2010 classification criteria. The study populationconsists of 88 healthy subjects and 88 RA patients. Sandwich ELISA technique was used to assess serum COMP level. Other inflammatory markers such as erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) antibodies like rheumatoid factor, and anti-cyclic citrullinated protein (anti-CCP) were also assessed. Results were analyzed using SPSS-20 and P-value ≤0.05 was considered as significant.Results: Serum COMP levels were significantly higher in RA patients 51.35ng/ml than controls 21.454ng/ml with significant p value=<0.0001. There was strong positive correlation between COMP level and disease severity in RA patients with moderate as well as high disease activity score (DAS) with significant p value. Serum COMP showed 96% sensitivity and 83% specificity at level of 27.01ng/ml for diagnosis of RA.Conclusions:COMP has significant positive correlation with severity of RA. Serum COMP can be utilized as a biomarker to quantify cartilage destruction in RA patients
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The incidence of cartilage degeneration (osteoarthritis, etc.) is increasing year by year, putting heavy pressure on families and society. It has become a consensus that mesenchymal stem cells can repair damaged cartilage. As the research progresses, more and more evidence indicates that its effects are attributed to the paracrine system, especially the exosomes. Exosomes are a lipid bilayer cystic structure encapsulating biologically active factors such as proteins, lipids, mRNA, and microRNAs (miRNAs/miRs), which can regulate the biological functions of cells. As a signal and carrier for transmitting important information between cells, it plays a very important role in the repair of cartilage degeneration damage. This paper reviews the research of mesenchymal stem cell-derived exosomes carrying miRNAs in the repair of cartilage injury.
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Objective: To investigate the role and mechanism of S100 calcium binding protein B (S100B) in osteoarthritis (OA) cartilage damage repair. Methods: Twenty New Zealand rabbits were randomly divided into control group and model group, with 10 rabbits in each group. Rabbits in the model group were injured by the right knee joint immobilization method to make the artilage injury model, while the control group did not deal with any injury. After 4 weeks, the levels of interleukin-1β (IL-1β) and tumor necrosis factor α (TNF-α) in synovial fluid were detected by ELISA method; the mRNA and protein expressions of S100B, fibroblast growth factor 2 (FGF-2), and FGF receptor 1 (FGFR1) in cartilage tissue were examined by real-time fluorescence quantitative PCR (qRT-PCR) and Western blot assay. Human synovial fibroblasts (SF) were isolated and cultured in vitro. The effects of S100B overexpression and knockdown on the levels of IL-1β and TNF-α (ELISA method) and the expressions of FGF-2 and FGFR1 gene (qRT-PCR) and protein (Western blot) were observed. Moreover, the effects of FGFR1 knockdown in above S100 overexpression system on the levels of IL-1β and TNF-α (ELISA method) and the expressions of FGF-2 and FGFR1 gene (qRT-PCR) and protein (Western blot) were observed. Results: ELISA detection showed that the expressions of IL-1β and TNF-α in the synovial fluid of the model group were significantly higher than those of the control group ( P<0.05); qRT-PCR and Western blot detection showed that the mRNA and protein expressions of S100B, FGF-2, and FGFR1 in cartilage tissue were significantly higher than those of the control group ( P<0.05). Overexpression and knockdown S100 could respectively significantly increase and decrease lipopolysaccharides (LPS) induced IL-1β and TNF-α levels elevation and the mRNA and protein expressions of FGF-2 and FGFR1 ( P<0.05); whereas FGFR1 knockdown could significantly decrease LPS induced IL-1β and TNF-α levels elevation and the mRNA and protein expressions of FGF-2 and FGFR1 ( P<0.05). Conclusion: S100B protein can regulate the inflammatory response of SF and may affect the repair of cartilage damage in OA, and the mechanism may be related to the activation of FGF-2/FGFR1 signaling pathway.
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Hedgehog signaling pathway plays an key role in the process of endochondral bone formation, regulating the proliferation and differentiation of chondrocytes in epiphyseal growth plate. In recent years, it has been found that abnormal expression of Hedgehog signaling pathway-related molecules is involved in a variety of osteoarthropathy. Therefore, studying the relationship between Hedgehog signaling pathway and cartilage damage is of great significance to elucidate the molecular mechanism of osteoarthropathy. In this paper, we focus on the research progress of Hedgehog signaling pathway in chondrocyte proliferation, differentiation, apoptosis and cartilage matrix metabolism, which may provide new insights into mechanism and prevention of osteoarthropathy.
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Articular cartilage injuries caused by traumatic, mechanical and/or by progressive degeneration result in pain, swelling, subsequent loss of joint function and finally osteoarthritis. Due to the peculiar structure of the tissue (no blood supply), chondrocytes, the unique cellular phenotype in cartilage, receive their nutrition through diffusion from the synovial fluid and this limits their intrinsic capacity for healing. The first cellular avenue explored for cartilage repair involved the in situ transplantation of isolated chondrocytes. Latterly, an improved alternative for the above reparative strategy involved the infusion of mesenchymal stem cells (MSC), which in addition to a self-renewal capacity exhibit a differentiation potential to chondrocytes, as well as a capability to produce a vast array of growth factors, cytokines and extracellular matrix compounds involved in cartilage development. In addition to the above and foremost reparative options up till now in use, other therapeutic options have been developed, comprising the design of biomaterial substrates (scaffolds) capable of sustaining MSC attachment, proliferation and differentiation. The implantation of these engineered platforms, closely to the site of cartilage damage, may well facilitate the initiation of an \'in situ' cartilage reparation process. In this mini-review, we examined the timely and conceptual development of several cell-based methods, designed to repair/regenerate a damaged cartilage. In addition to the above described cartilage reparative options, other therapeutic alternatives still in progress are portrayed.