Animal Models Of Osteoarthritis Research Articles

Antioxidant taurine inhibits chondrocyte ferroptosis through upregulation of OGT/Gpx4 signaling in osteoarthritis induced by anterior cruciate ligament transection.

The aim of this study was to investigate the potential molecular mechanisms by which taurine protects against cartilage degeneration. The anterior cruciate ligament transection (ACLT) surgery was used to construct an animal model of osteoarthritis (OA). Metabolomics was used to identify characteristic metabolites in osteoarthritic chondrocytes. Transcriptomics and metabolomics were used to explore potential mechanisms by which the small molecule metabolite taurine protects against inflammatory chondrocyte damage. Cell transfection and small molecule inhibitors/agonists were used to validate the molecular mechanisms by which taurine protects inflammatory chondrocytes in vitro. Finally, adeno-associated virus and small molecule inhibitors/agonists were used to validate the molecular mechanisms by which taurine protects against cartilage degeneration in vivo. Metabolomic assays identified taurine as a possible key metabolic molecule in the progression of OA. Transcriptomics and metabolomics revealed that O-GlcNAc transferase (OGT)-dependent O-GlcNAcylation and Gpx4-dependent ferroptosis may mediate the inflammatory protective effects of taurine on chondrocytes, which was further confirmed by gain and loss of function in vitro. Subsequently, further experiments indicated that the possible existence of a direct binding site for Gpx4 and OGT proteins, which provides evidence for the presence of O-GlcNAc modification of Gpx4 protein. Finnaly, we demonstrated that Gpx4-dependent ferroptosis and OGT-dependent O-GlcNAcylation may be potential mechanisms by which taurine protects against cartilage degeneration in vivo. Antioxidant taurine inhibits chondrocyte ferroptosis through upregulation of OGT/Gpx4 signaling. Supplementation with taurine, a safe nonessential amino acid, may be a potential therapeutic strategy for OA.

ShK-modified UCMSCs Inhibit M1-Like Macrophage Polarization and Alleviate Osteoarthritis Progression via PI3K/Akt Axis.

The potassium channel Kv1.3 plays an important role in regulating immune cell functions in many inflammatory diseases whereas rarely in osteoarthritis (OA). Here, it is demonstrated that the Kv1.3 of macrophages is upregulated in response to LPS stimulation, as well as in human OA synovium samples than non-OA. Administration of Stichodactyla toxin (ShK), a Kv1.3 blocker, significantly inhibited cartilage degeneration and synovial inflammation in animal models of OA in vivo by inhibiting M1 macrophage polarization and reducing the production of inflammatory factors. In this study, a transgenically engineered human umbilical cord mesenchymal stem cell (UCMSC) delivery system is developed that secreted a peptide ShK, a Kv1.3 potassium blocker, into the knee articular cavity. Collectively, the results identified Kv1.3 as a potential therapeutic target for OA and demonstrated the efficacy of using ShK transgenic engineered UCMSCs as a delivery for the peptide in OA treatment.

Quercetin attenuates the symptoms of osteoarthritis in vitro and in vivo by suppressing ferroptosis via activation of AMPK/Nrf2/Gpx4 signaling.

Osteoarthritis (OA) is a common joint disorder involving the cartilage and other joint tissues. Quercetin (QCT) serves a protective role in the development of OA. However, to the best of our knowledge, the regulatory mechanisms of QCT in the progression of OA have not yet been fully elucidated. In order to mimic a model of OA in vitro, IL‑1β was used to stimulate chondrocytes. Furthermore, an in vivo animal model of OA was induced by anterior cruciate ligament transection (ACLT). 5‑Ethynyl‑2'‑deoxyuridine assays, TUNEL assays, ELISAs, western blotting and immunohistochemical assays were conducted to assess the chondroprotective properties of QCT in the development of OA. The results revealed that 100 µM QCT significantly promoted the proliferation, reduced the apoptosis and inflammation, and inhibited the extracellular matrix (ECM) degradation in IL‑1β‑stimulated chondrocytes. Additionally, QCT attenuated the IL‑1β‑induced ferroptosis of chondrocytes, as demonstrated by the reduced lipid reactive oxygen species and Fe2+ levels. Conversely, the inhibitory effects of QCT on the apoptosis and inflammatory responses were reversed by the activation of ferroptosis by erastin in IL‑1β‑stimulated chondrocytes. Furthermore, QCT significantly elevated the level of phosphorylated (p‑)5' AMP‑activated protein kinase (AMPK) and the levels of two negative regulators of ferroptosis [nuclear factor erythroid 2‑related factor 2 (Nrf2) and glutathione peroxidase 4 (Gpx4)] in IL‑1β‑stimulated chondrocytes. The AMPK inhibitor compound C notably reversed the promoting effects of QCT on phosphorylated‑AMPK, Nrf2 and Gpx4 expression in IL‑1β‑stimulated chondrocytes. Additionally, QCT markedly ameliorated the destruction and degradation of articular cartilage, and elevated the p‑AMPK, Nrf2 and Gpx4 levels in the mouse model of ACLT‑induced OA. Overall, the present study demonstrated that QCT inhibited the development of OA by suppressing ferroptosis via the activation of the AMPK/Nrf2/Gpx4 signaling pathway. These findings provide novel insights into the regulatory mechanisms of QCT for the treatment of patients with OA.

Hck promotes IL-1β-induced extracellular matrix degradation, inflammation, and apoptosis in osteoarthritis via activation of the JAK-STAT3 signaling pathway

We investigated role of haematopoietic cell kinase (Hck) in osteoarthritis (OA) and to explore the underlying mechanisms driving its effects. An OA animal model was established and after OA induction, rats received intra-articular injections of lentivirus twice a week for four weeks. Rats were divided into four groups: control (healthy rats without OA), OA model (rats with induced OA), OA + Len-si-NC (OA rats treated with a non-targeting control lentivirus), and OA + Len-si-Hck (OA rats treated with lentivirus targeting Hck). Blood samples were collected, and serum cytokine levels were measured using ELISA. Afterward, the rats were sacrificed for histological analysis and TUNEL assay. In vitro, IL-1β-treated human chondrocytes were transfected with Hck, and the effects on cell viability, apoptosis, ECM degradation, and JAK-STAT3 signaling were assessed. Colivelin, a JAK-STAT3 agonist, was used to confirm the pathway’s involvement. Results indicated increased Hck expression in the cartilage tissues of OA rats and in IL-1β-stimulated chondrocytes. Silencing Hck in vivo reduced IL-6 and TNF-α levels, apoptosis, and preserved cartilage structure. In vitro, Hck knockdown in IL-1β-treated chondrocytes resulted in enhanced cell viability, reduced apoptosis, and decreased ECM degradation. Notably, the expression of MMP3 and MMP13 was significantly lowered, while collagen II and aggrecan levels were restored. Additionally, Hck knockdown inhibited JAK-STAT3 activation, which was evident from reduced levels of phosphorylated JAK1 and STAT3. The addition of colivelin reversed these effects, confirming that Hck mediates its effects through the JAK-STAT3 pathway. Overall, our findings indicate that Hck is critical in OA progression by promoting inflammation, apoptosis, and ECM degradation through the JAK-STAT3 signaling pathway activation.

Andrographolide suppresses fibrogenic phenotype of chondrocytes and ameliorates osteoarthritis by regulating miR-137/BMP7 axis

BackgroundPathogenic degeneration of cartilage and the generation of fibrotic cartilage are crucial characteristics linked to the progression of osteoarthritis (OA). The current research aims to explore the potential function of the miR-137/BMP7 pathway in regulating the fibrogenic transition of chondrocytes associated with OA, as well as assess the therapeutic potential of andrographolide. MethodsSamples of cartilage from the knees of patients with OA and individuals without OA were gathered to investigate the expression patterns of miR-137, BMP7, and markers associated with fibrosis. A cell model using primary chondrocytes stimulated with interleukin (IL)-1β was developed to study the involvement of the miR-137/BMP7 axis during the fibrogenic transition of these cells. Additionally, we utilized an animal model of OA in order to assess the beneficial effects of the anti-inflammatory natural compound andrographolide on the fibrogenesis induced by OA in vivo. ResultsElevated levels of fibrogenic and inflammatory factors were linked to decreased miR-137 expression in OA samples. In IL-1β-treated chondrocytes, there was an upregulation of fibrogenic markers alongside a reduction in miR-137 levels. The overexpression of miR-137 inhibited fibrogenesis through the negative regulation of BMP7. Additionally, treatment with andrographolide was effective in attenuating the fibrogenic phenotype in chondrocytes and mitigating OA pathogenesis via modulating the miR-137/BMP7 pathway. ConclusionmiR-137 downregulation and BMP7 overexpression might contribute to the fibrogenic features in OA-related chondrocytes. Andrographolide attenuates fibrogenic phenotype in chondrocytes and alleviates the severity of OA by modulating the miR-137/BMP7 axis.

A drug-loaded nano chitosan/hyaluronic acid hydrogel system as a cartilage tissue engineering scaffold for drug delivery

Cartilage lesions, especially osteoarthritis (OA), usually arise from aging, trauma, or obesity and require medical intervention due to the damaged site's inflammation and the cartilage tissue's poor self-healing capacity. This study aimed to prepare a drug-loaded nanoparticle hydrogel system with anti-inflammatory and chondroprotective effects to treat OA. First, hyaluronic acid (HA) was oxidized to create aldehyde functional groups and then cross-linked with adipic acid dihydrazide (ADH) to form a hydrogel. Next, chitosan nanoparticles (CS NPs) loaded with an anti-inflammatory molecule (fisetin) and or a chondrogenic and chondroprotective agent (kartogenin) were incorporated into the hyaluronan hydrogel to improve the release profile of the drug and increase its retention time in the joint cavity. Incorporating drug-loaded NPs into the hyaluronan hydrogel provided the hydrogel with controlled release features and improved properties. In addition, the real-time PCR (polymerase chain reaction) results showed that the hyaluronan hydrogel containing both drug-loaded NPs performed better than either constituent alone on an in vitro model of OA. Finally, based on the results of in vitro evaluation, this drug-loaded nanoparticle hydrogel system can be a promising technique for treating OA by rapidly suppressing inflammation and supporting cartilage regeneration and requires further investigation in an animal model of OA. Meanwhile, this study investigated, for the first time, the effect of the simultaneous use of fisetin and kartogenin together with a nano CS/HA hydrogel system to treat OA.

Intra-Articular Injection of Human Umbilical Cord-Derived Mesenchymal Stromal Cells Reduces Radiographic Osteoarthritis in an Ovine Model.

To determine if mesenchymal stromal cells (MSCs) derived from human umbilical cords (hUC) could reduce degeneration developing when injected into the knee of a large animal model of osteoarthritis (OA). Ten million culture-expanded UC-MSCs (pooled from 3 human donors) were injected in 50 μL of tissue culture medium into the left stifle joints of 7 sheep whose medial meniscus was transected 4 weeks previously. Seven other sheep had only 50 μL of medium injected as the no treatment "control" group. After 8 weeks the sheep underwent euthanasia, the joints were excised and examined macroscopically, via x-ray and magnetic resonance imaging (MRI), both via histology for degenerative and inflammatory changes and immunohistochemically to identify any human cells within the joint tissues. Activity monitoring both before meniscus transection and euthanasia was also undertaken. There was a significant reduction in the Kellgren-Lawrence x-ray score for joints injected with hUC-MSCs compared with the control joints. Likewise, macroscopic, MRI, synovitis and OARSI histology scores were all lower (better) in the joints injected with hUC-MSCs than in the control arm, but not significantly. Activity levels and synovitis scores were similar in both groups of animals. hUC-MSCs appear to modify and reduce the development of osteoarthritic changes in the ovine stifle joint after meniscal destabilization, an injury which commonly leads to OA in humans. These results are encouraging for the potential benefit of culture expanded UC-MSCs as an allogeneic cell therapy in patients who may have early OA following a meniscal injury of the knee.

Targeting Long Noncoding RNA H19 in Subchondral Bone Osteocytes and the Alleviation of Cartilage Degradation in Osteoarthritis.

Emerging evidence suggests long noncoding RNA H19 is associated with osteoarthritis (OA) pathology. However, how H19 contributes to OA has not been reported. This study aims to investigate the biologic function of H19 in OA subchondral bone remodeling and OA progression. Clinical joint samples and OA animal models induced by surgical destabilization of the medial meniscus (DMM) were used to verify the causal relationship between osteocyte H19 and OA subchondral bone and cartilage changes. MLO-Y4 osteocyte cells subjected to fluid shear stress were used to verify the mechanism underlying H19-mediated mechanoresponse. Finally, the antisense oligonucleotide (ASO) against H19 was delivered to mice knee joints by magnetic metal-organic framework (MMOF) nanoparticles to develop a site-specific delivery method for targeting osteocyte H19 for OA treatment. Both clinical OA subchondral bone and wildtype mice with DMM-induced OA exhibit aberrant higher subchondral bone mass, with more H19 mice expressing osteocytes. On the contrary, mice with osteocyte-specific deletion of H19 are less vulnerable to DMM-induced OA phenotype. In MLO-Y4 cells, H19-mediated osteocyte mechanoresponse through PI3K/AKT/GSK3signal activation by EZH2-induced H3K27me3 regulation on protein phosphatase 2A inhibition. Targeted inhibition of H19 (using ASO-loaded MMOF) substantially alleviates subchondral bone remodeling and OA phenotype. In summary, our results provide new evidence that the elevated H19 expression in osteocytes may contribute to aberrant subchondral bone remodeling and OA progression. H19 appears to be required for the osteocyte response to mechanical stimulation, and targeting H19 represents a new promising approach for OA treatment.

Exploring the mechanism of tetramethylpyrazine in the treatment of osteoarthritis based on network pharmacology.

Osteoarthritis (OA) is the most common joint disease, which mainly damages articular cartilage and involves the whole joint tissue. It has the characteristics of long course, repeated symptoms and high disability rate, and the incidence trend is gradually increasing. Tetramethylpyrazine (TMP) is the main alkaloid active substance in Ligusticum wallichii, a traditional Chinese medicine, which has the effect of promoting blood circulation and dredging collaterals, and has a good effect on the treatment of early OA, but its molecular mechanism has not been fully clarified so far. Based on network pharmacology, molecular docking simulation and animal experiments, this study explored the target and molecular mechanism of TMP in the treatment of OA. We used PubChem, SwissTargetPrediction, and PharmMapper databases to predict the molecular structure and potential targets of TMP. GeneCards and DisGeNET databases were used to predict the relevant targets of OA. Apply UniProt database to convert targets into unified gene names, and proofread and remove duplicate gene names. The intersection targets of TMP and OA obtained on venny2.1.0 website were submitted to the STRING database to construct a PPI network. CytoScape 3.8.2 software was used to analyze the PPI network and obtain the sub-network modules and 10 key targets. The intersection targets of TMP and OA were analyzed by Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) enrichment using DAVID 6.8 database. The intersecting targets of TMP and OA, the biological process of GO enrichment, and KEGG signaling pathway were imported into Cytoscape 3.8.2 software to construct the TMP-target-pathway network diagram. Use molecular docking technology to simulate the interaction between TMP molecules and key targets, and predict the binding mode and binding ability. Animal models of rabbit knee osteoarthritis were prepared, and magnetic resonance imager (MRI) and fluorescence quantitative PCR (RT-qPCR) were used to observe the effect of TMP in treating OA as well as the expression of key target genes. 585 potential targets of TMP, 3,857 potential targets of OA, and 49 intersecting targets of TMP and OA were obtained. The top 10 key target genes were obtained, in order of ranking: ALB, ESR1, IL10, CAT, F2, MPO, C3, CYP3A4, CYP2C9, ANXA1. GO and KEGG analysis implied that the key targets might act on OA by affecting endothelial cell permeability, peri-articular microcirculatory status, NETs production, activation of complement system and coagulation pathway, regulation of immune function of macrophages and T cells, and substance metabolism pathway in vivo, etc. The molecular mechanism might involve the formation of neutrophil extracellular trap, regulation of the actin cytoskeleton, complement and coagulation cascades, and T cell receptor signaling pathways, etc. Molecular docking simulations showed that the binding energy of IL10 and ANXA1 to TMP was greater than -5Kal/mol, but the other key target proteins showed better binding to TMP, and the binding energy was less than -5kcal/mol. Animal experiments showed that TMP had a significant therapeutic effect on OA. The TMP group had significantly reduced knee joint effusion and bone marrow damage compared to the OA group (p < 0.05). The qRT-PCR results showed that compared with the OA group, the mRNA expression of ESR1, CAT, C3, CYP3A4, CYP2C9, and ANXA1 in the TMP group increased (p < 0.05), while there was no significant difference in mRNA expression of ALB, IL-10, F2, MPO, etc. (p > 0.05). TMP is effective in the treatment of OA, with multi-target and multi-pathway interactions. ESR1, CAT, C3, CYP3A4, CYP2C9, and ANXA1 may be potential targets for TMP treatment of OA. The molecular mechanism mainly involves the formation of neutrophil extracellular trap, regulation of the actin cytoskeleton, complement and coagulation cascades, and T cell receptor signaling pathways, etc.

Resatovir Combined with Glycyrrhizic Acid Ameliorates Osteoarthritis and Enhances Autophagy in Chondrocytes

Background Osteoarthritis (OA) is a chronic disease worldwide. With resatovir usually used as an inhibitor, resatovir and glycyrrhizic acid have several pharmacological activities. Purpose We intend to explore the mechanism underlying resatovir combined with glycyrrhizic acid in OA. Methods After the establishment of an animal model of OA through anterior cruciate ligament transection and destabilization of the medial meniscus, the rats were subjected to intramuscular injection of resatovir combined with glycyrrhizic acid (60 mg/kg) or 5% glucose (60 mg/kg) every day for 4 weeks. During the progress, the rat movement and the bend score of knees were observed through behavioral studies. Additionally, the SKP2 gene expression and toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB)-related signaling pathways were examined, as apoptosis and autophagy were evaluated by flow cytometry. Results With increased inflammatory cells in the model group, treatment with resatovir combined with glycyrrhizic acid significantly decreased the number of inflammatory cells. Meanwhile, the treatment resulted in decreased SKP2 expression in OA cells when hindering the migration of preosteoclast cells. Interestingly, it was observed that the bend score increased over the treatment with resatovir plus glycyrrhizic acid and TIPPI% declined dramatically. Resatovir treatment enhanced autophagy and apoptosis in OA cells and decreased pP65, P65, and LC3 expression. Conclusion Resatovir combined with glycyrrhizic acid can inhibit the inflammatory response through decreasing SKP2 expression and induce autophagy activation in OA cells through TLR4/NF-κB signaling, thereby attenuating OA progression.

Osteoarthritis early-, mid- and late-stage progression in the rat medial meniscus transection model.

Osteoarthritis is a degenerative disease of synovial joints affecting all tissues, including articular cartilage and subchondral bone. Osteoarthritis animal models can recapitulate aspects of human disease progression and are used to test efficacy of drugs, biomaterials, and cell therapies. The rat medial meniscus transection (MMT) model is a surgically induced posttraumatic osteoarthritis model commonly used for preclinical therapeutic screening. We describe herein, the qualitative and quantitative changes to articular cartilage, subchondral bone, and formation of osteophytes at early-, mid-, and late-stages of osteoarthritis progression. Tibia of MMT-operated animals showed proteoglycan loss and fibrillation along articular cartilage surfaces as early as 3-weeks post-surgery. With contrast-enhanced micro-CT technique, quantitative, 3-dimensional analysis of the tibia showed that the articular cartilage thickened at 3- and 6-weeks post-surgery and decreased at 12-weeks post-surgery. This decreased cartilage thickness corresponded with increased lesions in the articular cartilage that led to its full degradation and exposing the subchondral bone layer. Further, subchondral bone thickening was significant at 6-weeks post-surgery and followed cartilage damage. Osteophytes were found as early as 3-weeks post-surgery and coincided with articular cartilage degradation. Cartilaginous osteophytes preceded mineralization, suggesting endochondral ossification. The rat MMT model has predominantly been used out to 3-weeks, and most studies determined the effect of therapies to delay or prevent the onset of osteoarthritis. We provide evidence that an extension of the rat MMT model out to 6- and 12-weeks more resembled severe phenotypes of human osteoarthritis. Thus, evaluating novel therapeutics at late-stage will be important for eventual clinical translation.

A Histo-Physiological Study of The Effect of Resveratrol on Osteoporosis-Induced in Rats

Using an animal model of D-galactose-induced osteoporosis (OP), the researchers examined the effects of resveratrol supplementation on body weight, alkaline phosphatase (ALP) levels and bone calcin (OC) levels and classified mice randomized into the following groups: Subgroup C (n=10): within 60 days participants will receive 1 ml of distilled water. In the D-galactose group (n=10), osteoporosis will be induced by intraperitoneal administration of 200 mg/kg/day of D-galactose for 60 consecutive days. Group R of 10 subjects will receive a dose of 25 mg/kg of oral resveratrol for 60 days.The DR group of the group of 10 subjects will receive D-galactose 200 mg/kg/day intraperitoneally in for osteoporosis and oral resveratrol at 25 mg/kg/day for 60 days. There was a distinct difference in body weight before and after OP infusion in each group in the study. The D-galactose group (D) showed significantly higher levels of ALP and OC compared with the control group. In contrast, the resveratrol group (R) showed significantly lower levels compared with the control group and the D group. Finally, the group treated with the combination of D-galactose and resveratrol (DR) showed significantly higher levels compared to the control group and the group treated with resveratrol alone (R). the. and more microfractures On the other hand, the resveratrol group (R) had thicker bone trabeculae, reduced intertrabecular space, and fewer microfractures. In addition, a protective effect against D-galactose-induced changes was observed in the resveratrol group, and these effects were dose-dependent The findings suggested resveratrol treatment in an animal model of osteoarthritis induced by D-galactose improved their weight, bone turnover markers (ALP and OC), and histological parameters were dependent on resveratrol levels.

Exploring Intra-Articular Administration of Monoclonal Antibodies as a Novel Approach to Osteoarthritis Treatment: A Systematic Review.

Biological drugs, including monoclonal antibodies, represent a revolutionary strategy in all fields of medicine, offering promising results even in the treatment of osteoarthritis (OA). However, their safety and efficacy have not been fully validated, highlighting the need for in-depth studies. Therefore, we provided a comprehensive systematic review of the intra-articular use of monoclonal antibodies for the treatment of OA in animal models, reflecting ongoing efforts to advance therapeutic strategies and improve patient outcomes. A systematic literature search was conducted in December 2023 following the PRISMA guidelines, using the Web of Science, Google Scholar, and PUBMED databases. Out of a total of 456, 10 articles were included in the study analyzing intra-articular antibodies and focusing on various targets, including vascular endothelial growth factor (VEGF), nerve growth factor (NGF), interleukin 4-10 (IL4-10), tumor necrosis factor α (TNF-α), a disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS5), and matrix metalloproteinase 13 (MMP-13). Most studies administered the antibodies weekly, ranging from 1 to 10 injections. Animal models varied, with mean follow-up periods of 8.9 ± 4.1 weeks. The methods of assessing outcomes, including pain and morpho-functional changes, varied. Some studies reported only morphological and immunohistochemical data, while others included a quantitative analysis of protein expression. In conclusion, monoclonal antibodies represent a promising avenue in the treatment of OA, offering targeted approaches to modulate disease pathways. Further research and clinical trials are needed to validate their safety and efficacy, with the potential to revolutionize the management of OA and reduce reliance on prosthetic interventions.

Comparative transcriptomic analysis of articular cartilage of post-traumatic osteoarthritis models.

Animal models of post-traumatic osteoarthritis (PTOA) recapitulate the pathological changes observed in human PTOA. Here, skeletally mature C57Bl6 mice were subjected to either rapid-onset non-surgical mechanical rupture of the anterior cruciate ligament (ACL) or to surgical destabilisation of the medial meniscus (DMM). Transcriptome profiling of micro-dissected cartilage at day7 or day42 following ACL or DMM procedure, respectively, showed that the two models were comparable and highly correlative. Gene ontology (GO) enrichment analysis identified similarly enriched pathways that were overrepresented by anabolic terms. To address the transcriptome changes more completely in the ACL model, we also performed small RNA sequencing, describing the first microRNA profile of this model. miR-199-5p was amongst the most abundant, yet differentially expressed, microRNAs, and its inhibition in primary human chondrocytes led to a transcriptome response that was comparable to that observed in both human 'OA damaged vs intact cartilage' and murine DMM cartilage datasets. We also experimentally verified CELSR1, GIT1, ECE1 and SOS2 as novel miR-199-5p targets. Together, these data support the use of the ACL rupture model as a non-invasive companion to the DMM model.

Cell‐based therapies have disease‐modifying effects on osteoarthritis in animal models: A systematic review by the ESSKA Orthobiologic Initiative. Part 3: Umbilical cord, placenta, and other sources for cell‐based injectable therapies

AbstractPurposeThis systematic review aimed to investigate in animal models the presence of disease‐modifying effects driven by non‐bone marrow‐derived and non‐adipose‐derived products, with a particular focus on umbilical cord and placenta‐derived cell‐based therapies for the intra‐articular injective treatment of osteoarthritis (OA).MethodsA systematic review was performed on three electronic databases (PubMed, Web of Science and Embase) according to PRISMA guidelines. The results were synthesised to investigate disease‐modifying effects in preclinical animal studies comparing injectable umbilical cord, placenta, and other sources‐derived products with OA controls. The risk of bias was assessed using the SYRCLE tool.ResultsA total of 80 studies were included (2314 animals). Cell therapies were most commonly obtained from the umbilical cord in 33 studies and placenta/amniotic tissue in 18. Cell products were xenogeneic in 61 studies and allogeneic in the remaining 19 studies. Overall, 25/27 (92.6%) of studies on umbilical cord‐derived products documented better results compared to OA controls in at least one of the following outcomes: macroscopic, histological and/or immunohistochemical findings, with 19/22 of studies (83.4%) show positive results at the cartilage level and 4/6 of studies (66.7%) at the synovial level. Placenta‐derived injectable products documented positive results in 13/16 (81.3%) of the studies, 12/15 (80.0%) at the cartilage level, and 2/4 (50.0%) at the synovial level, but 2/16 studies (12.5%) found overall worse results than OA controls. Other sources (embryonic, synovial, peripheral blood, dental pulp, cartilage, meniscus and muscle‐derived products) were investigated in fewer preclinical studies. The risk of bias was low in 42% of items, unclear in 49%, and high in 9% of items.ConclusionInterest in cell‐based injectable therapies for OA treatment is soaring, particularly for alternatives to bone marrow and adipose tissue. While expanded umbilical cord mesenchymal stem cells reported auspicious disease‐modifying effects in preventing OA progression in animal models, placenta/amniotic tissue also reported deleterious effects on OA joints. Lower evidence has been found for other cellular sources such as embryonic, synovial, peripheral blood, dental‐pulp, cartilage, meniscus, and muscle‐derived products.Level of EvidenceLevel II.

Osteoarthritis induced by monosodium iodoacetate model

Objectives: this study aimed to highlight the evolution of the osteoarthritis (OA) model induced by monosodium iodoacetate (MIA) and its collaboration with the knowledge of the pathophysiology of inflammation, hypernociception and cartilage degeneration. Methods: PubMed and Science Direct were used with the descriptors: knee osteoarthritis or osteoarthritis of ankle) and (rat or osteoarthritis induced by monoiodoacetate) and (animal model of osteoarthritis or joint nociception). Studies containing rats, mice, and monoiodoacetate-induced osteoathritis were included. Exclusion criteria were: Animal models of osteoarthritis induced by destabilization; meniscectomy-induced osteoarthritis; non-invasive animal models of osteoarthritis induced by fracture, compression and tibial overload; animal models of osteoarthritis with large animals and models of osteoarthritis by papain or bacterial collagenase. We summarized studies that used MIA to induce knee or ankle OA in rats or mice and the evolution of the inflammatory markers. Results: a total of 38 original manuscripts met the inclusion criteria and were considered in the study. The model of OA induced by MIA is well-established and explored with several methodologies and has been widely used in different species. MIA induces cell death, progressive loss of chondrocytes and histological changes that mimics human OA. Studies with this model demonstrated inflammation, neurogenic hyperalgesia, release of cytokines and matrix metalloproteinases. More recently, molecular biology data confirm the activation of nuclear transcription factors, which modulates the expression of citokines in apoptotic chondrocytes. Conclusion: the MIA-induced OA has been useful in predicting several characteristics for the elucidation of osteoarthritis pathophysiology.

PP2Ac Regulates Autophagy via Mediating mTORC1 and ULK1 During Osteoclastogenesis in the Subchondral Bone of Osteoarthritis.

The molecular mechanism underlying abnormal osteoclastogenesis triggering subchondral bone remodeling in osteoarthritis (OA) is still unclear. Here, single-cell and bulk transcriptomics sequencing analyses are performed on GEO datasets to identify key molecules and validate them using knee joint tissues from OA patients and rat OA models. It is found that the catalytic subunit of protein phosphatase 2A (PP2Ac) is highly expressed during osteoclastogenesis in the early stage of OA and is correlated with autophagy. Knockdown or inhibition of PP2Ac weakened autophagy during osteoclastogenesis. Furthermore, the ULK1 expression of the downstream genes is significantly increased when PP2Ac is knocked down. PP2Ac-mediated autophagy is dependent on ULK1 phosphorylation activity during osteoclastogenesis, which is associated with enhanced dephosphorylation of ULK1 Ser637 residue regulating at the post-translational level. Additionally, mTORC1 inhibition facilitated the expression level of PP2Ac during osteoclastogenesis. In animal OA models, decreasing the expression of PP2Ac ameliorated early OA progression. The findings suggest that PP2Ac is also a promising therapeutic target in early OA.

METTL14-mediated lncRNA-FAS-AS1 promotes osteoarthritis progression by up-regulating ADAM8.

Osteoarthritis (OA) is a prevalent degenerative disease. We explored the role and regulatory mechanisms of lncRNA-FAS-AS1 in OA progression. We exposed human immortalized chondrocytes to IL-1β for 24 h to induce an OA cell model. The target molecule levels were assessed using western blot and quantitative real-time PCR (RT-qPCR). Cell viability and apoptosis were measured using CCK-8 and flow cytometry. The m6A modification of FAS-AS1 was determined using MeRIP. We examined the binding relationships between FAS-AS1, Fragile X mental retardation 1 (FMR1), and A disintegrin and metalloproteinase 8 (ADAM8) using RIP and RNA pull-down. The OA animal model was established by separating the medial collateral ligament and medial meniscus. Safranin-O staining and Mankin's scale were employed to evaluate pathological changes within the cartilage. FAS-AS1, METTL14, and ADAM8 were upregulated, and the JAK/STAT3 signaling pathway was activated in OA mice and IL-1β-induced chondrocytes. FAS-AS1 knockdown inhibited extracellular matrix degradation in IL-1β-induced chondrocytes; however, ADAM8 overexpression reversed this effect. FAS-AS1 maintained the stability of ADAM8 mRNA by recruiting FMR1. METTL14 knockdown repressed FAS-AS1 expression in an m6A-dependent manner. FAS-AS1 overexpression reversed the inhibitory effects of METTL14 knockdown on JAK/STAT3 signaling and cartilage damage in the OA model both invitro and invivo. METTL14-mediated FAS-AS1 promotes OA progression through the FMR1/ADAM8/JAK/STAT3 axis.

The cereblon-AMPK (AMP-activated protein kinase) axis in chondrocytes regulates the pathogenesis of osteoarthritis

ObjectiveAMP-activated protein kinase (AMPK) dysregulation is implicated in osteoarthritis (OA), but the mechanisms underlying this dysregulation remain unclear. We investigated the role of cereblon, a substrate-recognition protein within the E3-ligase ubiquitin complex, in AMPK dysregulation and OA pathogenesis. MethodsCereblon expression was examined in human (n=5) and mouse (n=10) OA cartilage. The role of cereblon was investigated through its adenoviral overexpression (n=10) or knockout (KO, n=15) in destabilization of the medial meniscus (DMM)-operated mice. The therapeutic potentials of the chemical cereblon degrader, TD-165, and the AMPK activator, metformin, were assessed through intra-articular (IA) injection to mice (n=15). ResultsImmunostaining revealed that cereblon is upregulated in human and mouse OA cartilage. In DMM model mice, cartilage destruction was exacerbated by overexpression of cereblon in mouse joint tissues (OARSI grade; 1.11 [95% CI: 0.50 to 2.75]), but inhibited in global (-2.50 [95% CI: -3.00 to -1.17]) and chondrocyte-specific (-2.17 [95% CI: -3.14 to -1.06]) cereblon KO mice. The inhibitory effects were more pronounced in mice fed a high-fat diet compared to a regular diet. The degradation of cereblon through IA injection of TD-165 inhibited OA cartilage destruction (-2.47 [95% CI: -3.22 to -1.56]). Mechanistically, cereblon exerts its catabolic effects by negatively modulating AMPK activity within chondrocytes. Consistently, activation of AMPK by IA injection of metformin inhibited posttraumatic OA cartilage destruction (-1.20 ([95% CI: -1.89 to -0.45]). ConclusionsThe cereblon-AMPK axis acts as a catabolic regulator of OA pathogenesis and seems to be a promising therapeutic target in animal models of OA.

Effects of Etanercept on Experimental Osteoarthritis in Rats: Role of Histone Deacetylases.

Mounting evidence suggests that histone deacetylases (HDAC) inhibitors reduce cartilage destruction in animal models of osteoarthritis (OA). Tumor necrosis factor (TNF)-α-blocking treatment for OA may provide effective joint protection by slowing joint damage. To investigate the effects of intraperitoneal administration of etanercept (a TNF-α inhibitor) on OA development in rats and changes in the nociceptive behavior of rats and expression of HDACs, RUNX2, and MMP13 in cartilage. Induction of OA in Wistar rats was accomplished through anterior cruciate ligament transection (ACLT). One or five milligrams (mg) of etanercept was administered intraperitoneally for 5 consecutive weeks after ACLT to the ACLT + etanercept (1 and 5 mg/kg) groups. Nociceptive behavior and changes in knee joint width were analyzed. Cartilage was evaluated histologically and immunohistochemically. ACLT + etanercept significantly improved mechanical allodynia and weight-bearing distribution compared to ACLT alone. In OA rats treated with etanercept, cartilage degeneration and synovitis were significantly less pronounced than those in ACLT rats. OA-affected cartilage also showed reduced expression of HDAC 6, 7, RUNX-2, and MMP-13 in response to etanercept but increased expression of HDAC4. Our study demonstrated that etanercept therapy (1) attenuated the development of OA and synovitis in rats, (2) reduced nociception, and (3) regulated chondrocyte metabolism, possibly by inhibiting cell HDAC6 and HDAC7, RUNX2, and MMP13 and increasing HDAC4 expression. Based on new evidence, etanercept may have therapeutic potential in OA.