Microvesicles-hydrogel breaks the cycle of cellular senescence by improving mitochondrial function to treat osteoarthritis.

BACKGROUND: Osteoarthritis (OA) is an age-related disease characterised by the accumulation of senescent chondrocytes, which drives its pathogenesis and progression. Senescent cells exhibit distinct features, including mitochondrial dysfunction and the excessive accumulation and release of reactive oxygen species (ROS), which are highly correlated and lead to a vicious cycle of increasing senescent cells. Stem cell therapy has proven effective in addressing cellular senescence, however, it still has issues such as immune rejection and ethical concerns. Microvesicles (MVs) constitute the primary mechanism through which stem cell therapy exerts its effects, offering a cell-free approach that circumvents these risks and has excellent anti-ageing potential. Nonetheless, MVs have a short in vivo half-life, and their secretion composition varies considerably under diverse conditions. This study aims to address these issues by constructing a ROS-responsive hydrogel loaded with pre-stimulant MVs. Through responding to ROS levels this hydrogel intelligently releases MVs, and enhancing mitochondrial function in chondrocytes to improving cellular senescence. RESULT: We employed Interferon-gamma (IFN-γ) as a stem cell-specific stimulus to generate IFN-γ-microvesicles (iMVs) with enhanced anti-ageing effects. Simultaneously, we developed a ROS-responsive carrier utilising 3-aminophenylboronic acid (APBA)-modified silk fibroin (SF) and polyvinyl alcohol (PVA). This carrier served to protect MVs, prolong longevity, and facilitate intelligent release. In vitro experiments demonstrated that the Hydrogel@iMVs effectively mitigated cell senescence, improved mitochondrial function, and enhanced cellular antioxidant capacity. In vivo experiments further substantiated the anti-ageing capabilities of the Hydrogel@iMVs. CONCLUSION: The effect of MVs can be significantly enhanced by appropriate pre-stimulation and constructing a suitable carrier. Therefore, we have developed a ROS-responsive hydrogel containing IFN-γ pre-stimulated iMVs to target the characteristics of ageing chondrocytes in OA for therapeutic purposes. Overall, this novel approach effectively improving mitochondrial dysfunction by regulating the balance between mitochondrial fission and fusion, and the accumulation of reactive oxygen species was reduced, finally, alleviates cellular senescence, offering a promising therapeutic strategy for OA.

Bone marrow mesenchymal stem cell-derived exosomal miR-206 promotes osteoblast proliferation and differentiation in osteoarthritis by reducing Elf3.

MicroRNAs (miRNAs) serve as gene silencers involved in essential cell functions. The role of miR-206 and E74-like factor 3 (Elf3) has been identified in osteoarthritis (OA), while the effect of exosomal miR-206 from bone marrow mesenchymal stem cells (BMSCs) in OA remains largely unknown. Thus, we aim to explore the role of exosomal miR-206 from BMSCs in OA with the involvement of Elf3. BMSCs and BMSC-derived exosomes (BMSC-exos) were obtained and identified. OA mouse models were constructed by anterior cruciate ligament transection and then treated with BMSC-exos or BMSC-exos containing miR-206 mimic/inhibitor. The expression of miR-206, Elf3, inflammatory factors, osteocalcin (OCN) and bone morphogenetic protein 2 (BMP2) in mouse femoral tissues was assessed. The pathological changes in mouse femur tissues were observed. The mouse osteoblasts were identified and treated with untransfected or transfected BMSC-exos, and then, the expression of miR-206, Elf3, OCN and BMP2 was determined. The alkaline phosphatase (ALP) activity, calcium deposition level, OCN secretion, proliferation, apoptosis and cell cycle arrest in osteoblasts were measured. MiR-206 was down-regulated while Elf3 was up-regulated in OA animal and cellular models. Exosomal miR-206 ameliorated inflammation and increased expression of OCN and BMP2 in mouse femoral tissues. Moreover, exosomal miR-206 promoted ALP activity, calcium deposition level, OCN secretion and proliferation and inhibited apoptosis in OA osteoblasts. Overexpressed Elf3 reversed miR-206 up-regulation-induced effects on OA osteoblasts. BMSC-derived exosomal miR-206 promotes proliferation and differentiation of osteoblasts in OA by reducing Elf3. Our research may provide novel targets for OA treatment.

Lycopene inhibits IL-1ß-induced inflammation in mouse chondrocytes and mediates murine osteoarthritis.

Osteoarthritis (OA) is a common chronic degenerative condition in the elderly, in which inflammation plays a key role in disease pathology. Lycopene (Lye), a member of the carotenoid family, has been reported to have anti-inflammatory effects. The purpose of this study was to investigate the effect of Lye on the inflammation of chondrocytes and the mouse OA model. Chondrocytes were treated with interleukin (IL)-1ß, and the mouse OA model was induced by the surgical destabilization of the medial meniscus (DMM). The results showed that Lye could inhibit the expression of inflammatory factors and alleviate the degradation of extracellular matrix (ECM). Additionally, Lye could activate the Nrf2/HO-1 pathway and reverse the activations of NF-κB and STAT3 signal pathway induced by IL-1ß, suggesting that its anti-inflammatory effect may be mediated via these pathways. The animal experiments showed that Lye could decrease the Osteoarthritis Research Society International (OARSI) scores of the knee, indicating that it could inhibit the occurrence and development of OA in mouse. Overall, our results indicated that Lye might be used as a novel drug for OA treatment.

Activating Nrf2 signalling alleviates osteoarthritis development by inhibiting inflammasome activation.

Osteoarthritis (OA), which is characterized by proliferation of subchondral bone and the degeneration of articular cartilage, is the most prevalent human arthritis. Nod-like receptor pyrin domain 3 (NLRP3) inflammasome is a hot spot in recent year and has been reported to be associated with OA synovial inflammation. However, there are few studies on NLRP3 inflammasome in chondrocyte. Licochalcone A (Lico A), a compound extracted from Glycyrrhiza species, has various biological effects such as anti-inflammation, anti-apoptotic, anti-cancer and anti-oxidation. In this study, we investigated the protective effect of Lico A on chondrocytes stimulated by lipopolysaccharide (LPS) and surgically induced OA models. In vitro, Lico A could reduce the expression of NLRP3, apoptosis-associated speck-like protein (ASC), Gasdermin D (GSDMD), caspase-1, interleukin-1beta (IL-1ß) and IL-18, which indicated that Lico A attenuates LPS-induced chondrocytes pyroptosis. In addition, Lico A ameliorates the degradation of extracellular matrix (ECM) by enhancing the expression of aggrecan and collagen-II. Meanwhile, we found that Lico A inhibits NLRP3 inflammasome via nuclear factor erythroid-2-related factor 2 (Nrf2)/haeme oxygenase-1(HO-1)/nuclear factor kappa-B (NF-κB) axis. And the Nrf2 small interfering RNA (siRNA) could reverse the anti-pyroptosis effects of Lico A in mouse OA chondrocytes. In vivo, Lico A mitigates progression OA in a mouse model and reduces OA Research Society International (OARSI) scores. Thus, Lico A may have therapeutic potential in OA.

Lubricin-Inspired Nanozymes Reconstruct Cartilage Lubrication System with an "In-Out" Strategy.

Lubricin, secreted primarily by chondrocytes, plays a critical role in maintaining the function of the cartilage lubrication system. However, both external factors such as friction and internal factors like oxidative stress can disrupt this system, leading to osteoarthritis. Inspired by lubricin, a lubricating nanozyme, that is, Poly-2-acrylamide-2-methylpropanesulfonic acid sodium salt-grafted aminofullerene, is developed to restore the cartilage lubrication system using an "In-Out" strategy. The "Out" aspect involves reducing friction through a combination of hydration lubrication and ball-bearing lubrication. Simultaneously, the "In" aspect aims to mitigate oxidative stress by reducing free radical, increasing autophagy, and improving the mitochondrial respiratory chain. This results in reduced chondrocyte senescence and increased lubricin production, enhancing the natural lubrication ability of cartilage. Transcriptome sequencing and Western blot results demonstrate that it enhances the functionality of mitochondrial respiratory chain complexes I, III, and V, thereby improving mitochondrial function in chondrocytes. In vitro and in vivo experiments show that the lubricating nanozymes reduce cartilage wear, improve chondrocyte senescence, and mitigate oxidative stress damage, thereby mitigating the progression of osteoarthritis. These findings provide novel insights into treating diseases associated with oxidative stress and frictional damage, such as osteoarthritis, and set the stage for future research and development of therapeutic interventions.

LncRNA MEG3 Protects Chondrocytes From IL-1ß-Induced Inflammation via Regulating miR-9-5p/KLF4 Axis.

BACKGROUND: Osteoarthritis (OA) is a chronic degenerative disease of the joints characterized by articular cartilage damage, subchondral bone remodeling, osteophyte formation, and inflammatory changes. This work aims to investigate the protective role of long non-coding RNA (lncRNA) maternally expressed 3 (MEG3) against the apoptosis of chondrocytes. METHODS: Chondrocyte cell lines, CHON-001, and ATDC5 were treated with different doses of interleukin-1ß (IL-1ß) to mimic the inflammatory response during OA pathogenesis. Quantitative real-time polymerase chain reaction was performed to measure MEG3, miR-9-5p, and Krüppel-like factor 4 (KLF4) mRNA expression levels. MEG3 and KLF4 overexpression plasmids, MEG3 shRNA, miR-9-5p mimics, and miR-9-5p inhibitors were transfected into the cells. Cell counting kit-8, wound healing assay, and flow cytometry were conducted to determine cell viability, migration, and apoptotic rate. Dual-luciferase reporter assay was adopted to verify the targeting relationships among MEG3, miR-9-5p, and KLF4. Western blot was used to detect KLF4 protein expression. Enzyme-linked immunosorbent assay was employed to measure the levels of inflammatory factors. RESULTS: MEG3 expression in chondrocytes was down-regulated by the stimulation of IL-1ß, and MEG3 negatively regulated miR-9-5p expression but positively regulated KLF4 expression. MEG3 overexpression strengthened the viability and migration of CHON-001 and ATDC5 cells but restrained the apoptosis and inflammatory response, while MEG3 knockdown had opposite effects. miR-9-5p inhibition or KLF4 overexpression could counteract the effects of MEG3 knockdown on chondrocytes. Besides that, MEG3 was proved to be a molecular sponge for miR-9-5p, and KLF4 was verified as the target of miR-9-5p. CONCLUSION: MEG3 can promote chondrocyte proliferation and migration and inhibit apoptosis and inflammation by sponging miR-9-5p to induce KLF4 expression, which provides a promising therapy target for OA treatment.

The Tight-Rope Technique versus Clavicular Hook Plate for Treatment of Acute Acromioclavicular Joint Dislocation: A Systematic Review and Meta-Analysis.

Objective: The efficacy of the tight-rope (TR) technique and clavicular hook plate (CHP) for the treatment of acute acromioclavicular (AC) joint dislocation is controversial. This meta-analysis aimed to evaluate which method is more appropriate for the treatment of acute AC joint dislocation. Methods: We systematically searched the PubMed, EMBASE, Scopus, ISI Web of Science, Chinese VIP Database, and Chinese Wan-Fang databases from inception to January 2018 using the search term "acromioclavicular joint dislocation AND hook plate." All prospective and retrospective controlled trials that had compared functional scores, pain scores, reduction loss rates, coracoclavicular (CC) distances, and complications between TR and CHP for acute AC joint dislocation were identified. A total of 13 of 587 studies with 732 patients were included. TR was preferential to CHP for AC joint dislocation given its higher Constant-Murley score, lower Visual Analog Scale pain score, and comparable reduction loss rate and CC distance. Subgroup analyses of the surgical type of TR did not affect the outcome. Results: The TR technique appears to be associated with better functional recovery and less pain than CHP. In addition, it does not increase the risk of reduction loss, CC distance, or operation time. It is also not associated with other complications except the implant migration, and does not require removal of the internal fixation. Conclusions: Thus, our results indicated that for AC joint dislocation, the TR technique may be preferential.

Inhibiting TLR4 signaling by linarin for preventing inflammatory response in osteoarthritis.

Osteoarthritis (OA) is one of the most common degenerative diseases, ultimately leading to long-term joint pain and severe articular malformation. Controlling local chronic inflammation is a crucial strategy for delaying OA development. Linarin is a natural flavonoid glycoside that is widely available in Compositae, Chrysanthemum indicum and Dendrocalamus and processes protective effects in several animal models. The purpose of our work was to study the protective effect of Linarin for OA. Cellular experiments data showed that Linarin suppressed lipopolysaccharide (LPS)-caused the overproduction of nitric oxide (NO), prostaglandin E2 (PGE2), interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-α) in chondrocyte. In addition, LPS-stimulated expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide nitrate (iNOS) was decreased by Linarin pre-treatment. Together, Linarin prevented the catabiosis of extracellular matrix caused by LPS. For mechanism, Linarin inhibited the formation of Toll-like receptor 4 (TLR4) / myeloid differentiation protein-2 (MD-2) dipolymer complex and subsequently intervened NF-κB activation. Our mouse DMM model further clarified the protection of Linarin in vivo. In summary, our results suggested that Linarin may be a potential effective agent for OA.

The Protective Effect of Luteolin in Glucocorticoid-Induced Osteonecrosis of the Femoral Head.

Glucocorticoid-induced osteonecrosis of the femoral head (GIONFH) is a frequently occurring type of nontraumatic osteonecrosis. A failure of the timely treatment can eventually result in the collapse of the subchondral bone structure. Luteolin (Lut), a compound extracted from Rhizoma Drynariae, is reported to possess multiple pharmacological properties including anticancer, antioxidant, antiapoptosis, and antiinflammatory properties. However, whether Lut has a protective effect on the development of GIONFH remains unclear. In this study, we evaluated the effect of Lut on Dexamethasone (Dex)-induced STAT1/caspase3 pathway in vitro and evaluated GIONFH model in vivo. In vitro, Lut inhibited the upregulation of Dex-induced phospho-STAT1, cleaved caspase9, and cleaved caspase3. In addition, Lut inhibited Dex-induced expression of Bax and cytochrome c and increased the expression of B cell lymphoma-2(Bcl-2). In vivo, Lut decreased the proportion of empty lacunae in rats with GIONFH. Taken together, these findings indicate that Lut may have therapeutic potential in the treatment of GIONFH. Further, this effect might be achieved by suppressing mitochondrial apoptosis of osteoblasts via inhibition of STAT1 activity.

Salvianolic Acid A Has Anti-Osteoarthritis Effect In Vitro and In Vivo.

Osteoarthritis (OA) is a degenerative disease found in middle-aged and elderly people, which seriously affects their quality of life. The anti-inflammatory and anti-apoptosis pharmacological effects of salvianolic acid A (SAA) have been shown in many studies. In this study, we intended to explore the anti-inflammatory and anti-apoptotic effects of SAA in OA. We evaluated the expression of pro-inflammatory mediators and cartilage matrix catabolic enzymes in chondrocytes by ELISA, Griess reaction, immunofluorescence, and Western blot, which includes nitric oxide (NO), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), prostaglandin E2 (PGE2), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), MMPs (MMP-3, MMP-13), and ADAMTS-5. Bax, Bcl-2, and cleaved caspase-3 were also measured by Western blot methods. The results of this experiment in vitro showed that SAA not only inhibited the production of inflammatory mediators induced by IL-1ß and the loss of cartilage matrix but also reduced the apoptosis of mouse chondrocytes induced by IL-1ß. According to the results of immunofluorescence and Western blot, SAA inhibited the activation of the NF-κB pathway and MAPK pathway. The results of these in vitro experiments revealed for the first time that SAA down-regulated the production of inflammatory mediators and inhibited the apoptosis of mouse chondrocytes and the degradation of extracellular matrix (ECM), which may be attributed to the inhibition of the activation of NF-κB and MAPK signaling pathways. In the in vivo experiments, 45 mice were randomly divided among three groups (the sham group, OA group, and OA + SAA group). The results of animal experiments showed that SAA treatment for eight consecutive weeks inhibited further deterioration of OA. These results demonstrate that SAA plays an active therapeutic role in the development of OA.

Allicin inhibits osteoblast apoptosis and steroid-induced necrosis of femoral head progression by activating the PI3K/AKT pathway.

Steroid-induced avascular necrosis of the femoral head (SANFH) is a major complication of long-term or excessive clinical use of glucocorticoids. Allicin is a classical ingredient extracted from garlic and has many functions such as anti-apoptosis and antibacterial effects. The purpose of this study was to investigate the effect and the mechanism of allicin on apoptosis of osteoblasts induced by dexamethasone (Dex) and SANFH in rats. In vitro, we performed CCK-8, western blotting, TUNEL and other experiments, and the results of these experiments showed that allicin could inhibit the Dex-induced abnormal expression of C-caspase3, C-caspase9, Bax, cytochrome C and Bcl-2 by activating the PI3K/AKT pathway. In vivo, the results of micro-CT, hematoxylin-eosin staining and immunohistochemical analysis suggested that allicin could effectively inhibit the progress of SANFH in rats. In summary, our experiments indicate that allicin is a potential drug for the treatment of SANFH.

The protective effect of myricitrin in osteoarthritis: An in vitro and in vivo study.

Osteoarthritis (OA) is a long-term, chronic, progressive joint condition caused by a pathology characterized by the deterioration of joint cartilage and proliferation of subchondral bone. Myricitrin (Myr) is a flavonoid compound extracted from myrica rubra with potent anti-inflammatory properties, as demonstrated in various studies. However, the mechanisms by which Myr plays a protective role in OA are not completely understood. In this study, the anti-inflammatory properties and potential mechanisms of Myr on mouse chondrocytes treated with interleukin (IL) -1beta (ß) were explored in vitro and the role of Myr in a mouse model of OA in vivo. The production of pro-inflammatory factors, such as IL-6, tumor necrosis factor alpha (TNF-α), prostaglandin E2 (PGE2) and nitric oxide (NO) were assessed by enzyme linked immunosorbent assay (ELISA) and the Griess reaction. Protein expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), Collagen-II, matrix metalloproteinase(MMP)-13, MMP-3, thrombospondin motifs 5(ADAMTS5), inhibitor ofnuclear factor kappa-B (IκB), p-IκB, p65, p-p65, c-jun-terminal kinase (JNK), p-JNK, extracellular regulated protein kinases (ERK), p-ERK, p38 and p-p38 were quantified using Western blot analysis. In the present study, we found that Myr inhibited IL-1ß-induced production of NO and PGE2, expression of MMP-13, MMP-3 and ADAMTS5 and degradation of collagen-II in mouse chondrocytes. Mechanistically, Myr inhibited the activation of mitogen-activated protein kinase (MAPK) and nuclear factor kappa-B (NF-κB) treated with IL-1ß in mouse chondrocytes. In vivo, Myr decreased OA Research Society International (OARSI) scores in a surgically-induced mouse model of OA. These data suggest that Myr could be developed as a potential therapyfor OA.

The protective effect of hesperetin in osteoarthritis: an in vitro and in vivo study.

Osteoarthritis (OA), a progressive joint disorder, is principally characterized by the degeneration and destruction of articular cartilage. Previous research studies demonstrated that inflammation and ECM degradation play a major role in OA development. Hesperetin, the aglycone of neohesperidin found in the peel of Citrus aurantium L. (Rutaceae), demonstrated in several studies potential anti-inflammatory activity in a variety of diseases. However, the mechanisms by which hesperetin plays a protective role in osteoarthritis (OA) are not completely understood. In this study, we found the anti-inflammatory effects of hesperetin in the progression of OA in both in vitro and in vivo experiments. In vitro, IL-1ß-induced expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), nitric oxide (NO), tumor necrosis factor alpha (TNF-α), prostaglandin E2 (PGE2), and interleukin-6 (IL-6) were inhibited by hesperetin. Moreover, hesperetin down-regulated the IL-1ß-stimulated matrix metalloproteinase-13 (MMP-13) and thrombospondin motifs 5 (ADAMTS-5) while up-regulating collagen type II and aggrecan. Mechanistically, we revealed that hesperetin suppressed nuclear factor kappa B (NF-κB) signaling by activating the nuclear factor (erythroid-derived 2)-like 2 (Nrf2) in IL-1ß-induced chondrocytes. Hesperetin-induced repression of OA development is shown using a DMM model. Taken together, our findings suggest that hesperetin may be a novel potential therapeutic agent for repressing the development of OA.

Arthroscopic treatment of posterior instability of the shoulder with an associated reverse Hill-Sachs lesion using an iliac bone-block autograft.

Posterior dislocation of the shoulder is often accompanied by an impression fracture in the anterior surface of the humeral head, called a reverse Hill-Sachs injury. This bone defect can engage on the posterior glenoid rim, which can lead to recurrent instability and progressive joint destruction. We describe a new arthroscopic procedure that fills the reverse Hill-Sachs lesion with an iliac bone-block autograft and repairs the posterior articular capsule arthroscopically, which can stabilize the posterior shoulder. It avoids the need to detach the subscapularis tendon and can reduce the risks associated with open procedures. LEVEL OF EVIDENCE: V, technical note.

Troxerutin suppresses the inflammatory response in advanced glycation end-product-administered chondrocytes and attenuates mouse osteoarthritis development.

As a chronic degenerative joint disease, osteoarthritis (OA) is clinically characterized by a high incidence, long-term pain, and limited joint activity but without effective preventative therapy. Troxerutin (Tx) is a natural flavonoid, also called vitamin P4, which is widely present in plants consumed as part of our daily diet, such as cereals, various fruits and vegetables, tea, and coffee, and possesses various biological activities, especially an anti-inflammatory effect. Here, we aimed to investigate the potential chondroprotection of Tx in experimental OA development. In in vitro studies, human chondrocytes were isolated and exposed in advanced glycation end-products (AGEs) to simulate OA development. It was found that Tx pretreatment inhibited the AGE-induced production of pro-inflammatory factors in chondrocytes, such as cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), nitric oxide (NO), prostaglandin E2 (PGE2), tumor necrosis factor alpha (TNF-α), and interleukin-6 (IL-6). Meanwhile, AGE-medicated extracellular matrix (ECM) degradation was decreased in Tx-pretreated chondrocytes. Furthermore, we found that Tx pretreatment suppressed the activation of the nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways in AGE-exposed chondrocytes. In vivo, Tx treatment prevented the narrowing of the joint space, the calcification of cartilage, and the loss of proteoglycans in the mouse OA model. In brief, Tx is considered as a potential therapeutic agent for OA.