Search Results (188)

Introduction: Osteoarthritis (OA), a leading cause of disability among the elderly, is characterized by progressive joint tissue destruction. Fucoidan, a sulfated polysaccharide with known anti-inflammatory and antioxidant properties, has been investigated for its potential to protect against interleukin-1 beta (IL-1β)-induced articular tissue damage. Methods: Human primary chondrocytes and synovial fibroblasts were pre-treated with 100 μg/mL fucoidan before stimulation with 1 ng/mL of IL-1β. The protective effects of fucoidan were assessed by measuring oxidative stress markers and catabolic enzyme levels. These in vitro findings were corroborated using a rat anterior cruciate ligament transection-induced OA model. To explore the underlying mechanisms, particularly the interaction between microRNAs (miRs) and heme oxygenase-1 (HO-1), five candidate miRs were identified in silico and experimentally validated. Luciferase reporter assays were used to confirm direct interactions. Results: Fucoidan exhibited protective effects against IL-1β-induced oxidative stress and catabolic processes in both chondrocytes and synovial fibroblasts, consistent with in vivo observations. Fucoidan treatment restored HO-1 expression while reducing inducible nitric oxide synthase and matrix metalloproteinase levels in IL-1β-stimulated cells. Notably, this study revealed that fucoidan modulates the miR-22/HO-1 pathway, a previously uncharacterized mechanism in OA. Specifically, miR-22 was upregulated by IL-1β and subsequently attenuated by fucoidan. Luciferase reporter assays confirmed a direct interaction between miR-22 and HO-1. Conclusion: The results demonstrate that fucoidan mitigates OA-related oxidative stress in chondrocytes and synovial fibroblasts through the novel modulation of the miR-22/HO-1 axis. The miR-22/HO-1 pathway represents a crucial therapeutic target for OA, and fucoidan may offer a promising therapeutic intervention. Full article

Osteoarthritis (OA) is a leading cause of disability worldwide and is characterized by the gradual degradation of articular cartilage in weight-bearing joints, notably the knees and hips. However, the primary morphological and anatomical determinants of the disease onset and progression remain unclear. This narrative overview examines how variations in cartilage thickness—traditionally viewed as a biomechanical protective feature—can paradoxically compromise metabolic homeostasis during prolonged sedentary behavior. Intriguingly, compelling evidence suggests that despite its superior load-bearing capacity, thicker cartilage faces greater challenges in solute transport, a limitation further exacerbated by the formation of diffusion-resistant boundary layers at the cartilage–fluid interface during immobilization. This phenomenon restricts nutrient influx and impedes waste clearance, leading to the accumulation of catabolic byproducts in deep cartilage zones and accelerated extracellular matrix breakdown, potentially influencing OA pathogenesis. By critically synthesizing current debates on mechanical loading with emerging data on metabolic dysregulation, particularly nutrient diffusion limitations, this analysis underscores the urgent need for targeted investigation of synovial–cartilage interface dynamics and chondrocyte metabolism under low-motion conditions. This study further advocates for strategic research focusing on often-overlooked, silent metabolic imbalances among sedentary populations and recommends early-intervention strategies, such as periodic joint mobilization, ergonomic adaptations, and public-health campaigns, to reduce prolonged sitting, preserve joint function, and guide more effective prevention and management approaches for non-traumatic OA in contemporary contexts. Full article

Osteoarthritis (OA) is a prevalent and debilitating joint disease in older adults with a complex etiology. We investigated the role of SUMOylation, a post-translational modification, in OA pathogenesis, focusing on the mitochondrial chaperone Prohibitin (PHB1) and the cartilage homeostasis transcription factor PITX1. We hypothesized that oxidative stress-induced SUMOylation promotes PHB1 nuclear accumulation, leading to PITX1 downregulation and contributing to OA development. Analysis of cartilage specimens from 27 OA patients and 4 healthy controls revealed an increased nuclear accumulation of PHB1 in OA chondrocytes, accompanied by elevated levels of SUMO-1 and SUMO-2/3. Mechanistically, nuclear PHB1 interacted indirectly with SUMO-1 through a SUMO-interacting motif (SIM), and the deletion of this SIM prevented PHB1 nuclear trapping in OA cells. Furthermore, the SUMO-conjugating enzyme E2 (UBC9) encoded by the UBE2I gene was upregulated in knee OA cartilage, and its overexpression in vitro enhanced PHB1 nuclear accumulation. Consistently, transgenic mice overexpressing the Ube2i gene exhibited increased UBC9 in their knee cartilage, resulting in Pitx1 downregulation and the emergence of an early OA-like phenotype in articular chondrocytes. Our findings uncover a novel role for UBC9-mediated SUMOylation in primary knee and hip OA. This pathway enhances PHB1 nuclear accumulation, contributing to PITX1 repression and subsequent OA development. These results underscore the importance of SUMOylation in OA pathogenesis and suggest potential molecular targets for early diagnosis and therapeutic intervention. Full article

Previously, we reported that mammalian cells, specifically human dermal fibroblasts (HDFs), could be transdifferentiated by lactic acid bacteria (LAB). Later, we observed that HDFs incorporated LAB-derived ribosomes, forming the ribosome-induced cell clusters (RICs) and transdifferentiating into cells derived from all three germ layers. Based on this insight, we hypothesized that incorporating ribosomes into non-mammalian cells could reveal the universality of this mechanism and open the door to commercial applications. Our current study demonstrates that ribosome incorporation can transdifferentiate chick primary muscle-derived cells (CMCs) into adipocytes, osteoblasts, and chondrocytes. Furthermore, the culture medium supernatant from ribosome-incorporated CMCs was found to significantly enhance CMC’s proliferation. RNA-seq analysis revealed that RICs-CMC exhibit increased expression of genes related to multi-lineage cell growth. In addition, we developed a novel technological shift in meat production—the “CulNet System”—which replicates organ interactions within mechanical systems for cell-cultured meat production. While significant efforts are still required to implement this technology in a cost-effective manner, we believe that combining the “CulNet System” with ribosome-incorporated multipotent cells that have prolonged culture capability could substantially improve the scalability and cost-effectiveness of cultured chicken meat production. This report highlights a promising approach for cell-culture-based meat production, offering a sustainable alternative to traditional methods. Full article

Background/Objectives: Natural-origin PN HPT™ (Polynucleotides High Purification Technology) protect and revitalize chondrocytes, synoviocytes, and cartilage with a regenerative medicine perspective following intra-articular injection. This six-month, open-label data collection aimed to validate the benefits documented in previous studies of a single intra-articular injection of a proprietary PN HPT™/HA-based medical device in improving both subjective and objective manifestations of knee osteoarthritis in real-life ambulatory patients of both genders with unilateral or bilateral knee osteoarthritis. Methods: Efficacy and safety assessments, conducted at baseline before a single PN HPT™/HA injection and after three and six months of follow-up, included the Lequesne index and the patient-assessed Numeric Pain Rating Scale (NPRS), which focuses on pain intensity, as primary endpoints. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) was a secondary endpoint. Results: After three and six months, the mean baseline Lequesne index score improved by 43.8% and 51.4%, respectively. Concurrently, the mean NPRS score improvements were 42.2% and 54.7%. Furthermore, 32% of investigators and 15.5% of treated patients deemed optimal the clinical outcomes with no clinical worsening. Conclusions: With some limitations due to the uncontrolled design and relying on subjective rating scales only, the study confirms all previous findings about the benefits of combining PN HPT™ and HA in the same medical device for intra-articular injection in knee osteoarthritis. Full article

Osteoarthritis (OA) is a long-term degenerative condition of the joints, characterized by persistent inflammation, progressive cartilage breakdown, and impaired mitochondrial function. Recent studies have shown that hyperactivation of the mTORC1 pathway and metabolic reprogramming of chondrocytes contribute to disease progression. Nitazoxanide (NTZ), an oral antiparasitic agent approved by the Food and Drug Administration, has shown anti-inflammatory and mitochondrial protective effects in various disease situations; despite this, its application in osteoarthritis has yet to be fully investigated. Here, we assessed the therapeutic efficacy of NTZ using IL-1β-stimulated primary chondrocytes derived from patients with OA. NTZ substantially reduced the expression of proinflammatory cytokines and matrix metalloproteinases, restored mitochondrial membrane potential, and reduced mitochondrial reactive oxygen species levels. NTZ also effectively reversed IL-1β-induced glycolytic metabolic changes by inhibiting glucose uptake and GLUT1 expression. Mechanistically, NTZ inhibited the activation of the mTORC1 pathway and substantially increased AMPK phosphorylation. The siRNA-mediated AMPK knockdown negated NTZ-induced mitochondrial and metabolic improvements, suggesting that AMPK is a key upstream regulator of the protective actions of NTZ. NTZ can, therefore, effectively inhibit inflammatory metabolic reprogramming and mitochondrial dysfunction in OA chondrocytes through AMPK-dependent mTORC1 signaling inhibition, highlighting its potential as a disease-modifying therapy for OA. Full article

Smoking has been associated, among other factors, with musculoskeletal disorders. Although there is no consensus about the effects of smoking on osteoarthritis (OA), the increase in TNF-alpha in smokers has been considered an important factor in OA induction or progression. However, studies on the effects of smoking on chondrocytes are lacking. Here we aimed to study the effects of cigarette smoke extract (CSE) associated with a TNF-alpha inhibitor on cell death of primary human chondrocytes derived from osteoarthritic patients. CSE at 10% led to cell death by apoptosis after 48 h of incubation, together with caspase 3/7 activation, decrease in mitochondrial transmembrane potential, ROS production, and improvement in syndercan-1, perlecan, and RUNX2 gene expression. All these effects promoted by CSE were reversed by TNF-alpha inhibitor. Collagen II, F-actin, and SOX9 were also analyzed, and CSE promoted alteration in the expression of these proteins. In conclusion, our results support the clinical impact of smoking on OA development by showing the detrimental action of CSE on osteoarthritis-derived chondrocytes and the protective effects of TNF-alpha inhibitors, reinforcing the importance of this cytokine in the cartilage injury process. Full article

Background/Objectives: The treatment of cartilage damage is an ongoing challenge. Several techniques have been developed to address this problem. Matrix-Induced Autologous Chondrocyte Implantation (MACI) is often referred to as the “gold standard” for cartilage treatment. Numerous long-term outcome studies also have reported favorable results with Autologous Matrix-Induced Chondrogenesis (AMIC). Minced Cartilage Implantation (MCI) is a recently developed arthroscopic method. This technique has demonstrated promising outcomes, with the prospect of longer-term results still under investigation. This study aims to directly compare the patient-reported outcomes of these three techniques over a 2-year follow-up period. Methods: A total of N = 48 patients were included in the retrospective matched pair analysis (n = 16 MACI, n = 16 AMIC, n = 16 MCI). VAS, KOOS-Pain, and KOOS-Symptoms scores served as primary outcomes; the KOOS-ADL and -QOL and the Tegner Activity Scale (TAS) served as secondary outcomes. Results: All three groups did not differ from each other in the primary or secondary outcomes. Pain and function significantly improved from pre-surgery to two years after (VAS: p < 0.000; ES: η² = 0.27; KOOS-Pain: p < 0.000; ES: η² = 0.30; KOOS-Symptoms: p = 0.000; ES: η² = 0.26; KOOS-ADL: p > 0.000; ES: η² = 0.20; KOOS-QOL: p > 0.000; ES: η² = 0.30). There was no significant effect of time on the activity level. Conclusions: All three procedures show good patient-reported outcomes, low complication rates, and long graft longevity in the 2-year follow-up. Therefore, all three methods seem to be equally recommendable for the treatment of cartilage lesions. Full article

Background: Articular chondrocytes are specialized cells in synovial joint cartilage, responsible for maintaining and regenerating the extracellular matrix. Inflammation disrupts the balance between matrix synthesis and degradation, leading to cartilage breakdown. This process, commonly observed in conditions such as osteoarthritis, results in chondrocyte dysfunction and accelerates joint degeneration. Since TRPA1 channels are implicated in inflammatory processes, this study investigates the expression of TRPA1 channels in freshly dissociated rat articular chondrocytes and their modulation by anti-inflammatory agents. Methods: We used the whole-cell patch-clamp method to assess TRPA1 channel expression and modulation. Results: Freshly dissociated chondrocytes exhibit ion currents attributable to TRPA1 channel expression, with higher magnitudes observed in medium-sized cells. These currents decrease over time in primary culture. Treatment with pro-inflammatory agents (IL-1α, IL-1β, and LPS) increases TRPA1′s current magnitude. IL-1β treatment directly induces transient TRPA1 currents. Several signaling components activated during inflammation contribute to the IL-1β-induced enhancement of TRPA1 current density, including IL-1 R1, the adaptor protein MyD88, and the downstream kinases IRAK1 and IRAK4. Conclusions: Our findings demonstrate that healthy rat chondrocytes express functional TRPA1 channels and that inflammatory processes modulate their expression. Full article

Background/Objectives: Osteoarthritis (OA) is one of the most prevalent chronic conditions and significantly contributes to local and global disease burden. Common pharmaceuticals that are used to treat OA cause significant side effects, thus non-pharmaceutical bioactive alternatives have been developed that can impact OA symptoms without severe side-effects. One such alternative is the Red Algae Lithothamnion species (Litho). However, there is little mechanistic knowledge of its potential to effect OA gene expression, and a human in vitro model using commercially available cell lines to test its effectiveness has yet to be developed. Methods: Human osteoblast (hFOB 1.19. CRL-11372) and chondrocyte (C28/I2) cell lines were co-cultured indirectly using transwells. IL1-β was used to induce an inflammatory state and gene expression profiles following treatment were the primary outcome. Conclusions: Results indicated that the model was physiologically relevant, remained viable over at least seven days, untreated or following induction of an inflammatory state while maintaining hFOB 1.19. and C28/I2 cell phenotypic characteristics. Following treatment, Litho reduced the expression of inflammatory and pain associated genes, most notably IL-1β, IL-6, PTGS2 (COX-2) and C1qTNF2 (CTRP2). Confirmatory analysis with droplet digital PCR (ddPCR) revealed that Il-1β induced a significant reduction in C1qTNF2 at 7 days which was ameliorated with Litho treatment. These data present a novel and replicable co-culture model of inflammatory OA that can be used to investigate bioactive nutraceuticals. For the first time, this model demonstrated a reduction in C1qTNF2 expression that was mitigated by Red Algae Lithothamnion species. Full article

Background/Objectives: The consumption of food rich in anthocyanins, a natural pigment found in plants, has been associated with improved joint health. However, systematic efforts to summarise the effects of anthocyanins and their deglycosylated forms, anthocyanidins, in managing osteoarthritis (OA) are lacking. This scoping review aims to comprehensively summarise the current evidence regarding the role of anthocyanins and anthocyanidins in OA management and highlights potential research areas. Methods: A comprehensive literature search was performed using PubMed, Scopus, and Web of Science in January 2025 to look for primary studies published in English, with the main objective of investigating the chondroprotective effects of anthocyanins and anthocyanidins, regardless of their study designs. Results: The seven included studies showed that anthocyanins and anthocyanidins suppressed the activation of inflammatory signalling, upregulated sirtuin-6 (cyanidin only), and autophagy (delphinidin only) in chondrocytes challenged with various stimuli (interleukin-1β, oxidative stress, or advanced glycation products). Anthocyanins also preserved cartilage integrity and increased the pain threshold in animal models of OA. No clinical trial was found in this field, suggesting a translation gap. Conclusions: In conclusion, anthocyanins and anthocyanidins are potential chondroprotective agents, but more investigations are required to overcome the gap in clinical translation. Full article

Osteoarthritis (OA), caused by the long-term use of joints, is a representative degenerative disease in the elderly. However, recently, the age of onset has been decreasing owing to excessive activities among young people in their 20s and 30s. Gynostemma pentaphyllum (Thunb.) Makino (GP), a perennial herb of the Cucurbitaceae family, has been used since the Ming dynasty as a medicinal material to treat various ailments, such as rheumatism, liver disease, and diabetes. In this study, we investigated the anti-arthritic effects of heat-processed Gynostemma pentaphyllum extract (Actiponin (AP)) and its derivatives, damulin A (DA) and damulin B (DB), using in vitro (primary rat chondrocytes and SW1353 cells) and in vivo (destabilization of the medial meniscus (DMM)-induced OA model) systems. Histological analysis results from the in vivo study showed that the group that underwent DMM surgery induced degeneration by the loss of proteoglycan and the destruction of cartilage (OARSI score 14 ± 0.57), whereas the group that received AP daily for 8 weeks maintained an intact condition (OARSI score 5 ± 0.28 at 200 mg/kg, p < 0.001). In addition, cartilage thickness and chondrocytes were reduced in the DMM group, but were restored in the AP-administered group. Furthermore, the von Frey analysis results showed that the pain threshold of the DMM group was considerably low (54.5 g at 8 weeks), whereas that of the AP group was dose-dependently increased (65.5, 69.5, 70.3, and 71.8 at 8 weeks for 30, 50, 100, and 200 mg/kg, respectively). In vitro studies showed that AP, DA, and DB reduced the expression of interleukin-1β alone-induced nitrite; inducible nitric oxide synthase; cyclooxygenase-2; matrix metallopeptidase 1/3/13; and a disintegrin and metalloproteinase with thrombospondin motifs 4/5. They also restored the expression of collagen type II and aggrecan, which are components of the extracellular matrix. The anti-arthritic effects of AP, DA, and DB were confirmed to be mediated by the mitogen-activated protein kinase and nuclear factor kappa-light-chain-enhancer of activated B cell signaling pathways. Collectively, these results suggest that AP is a potential therapeutic agent for mitigating OA progression and chondroprotection. Full article

Hemifacial microsomia (HFM) is a rare congenital craniofacial deformity that significantly impacts the appearance and hearing. The genetic etiology of HFM remains largely unknown, although genetic factors are considered to be primary contributors. We previously identified CTDSP2 as a potential causative gene in HFM cases. Utilizing CRISPR/Cas9, we knocked out ctdsp2 in zebrafish and analyzed the spatiotemporal expression of ctdsp2 and neural crest cell (NCC) markers through in situ hybridization (ISH). Craniofacial cartilage and chondrocyte phenotypes were visualized using Alcian blue and wheat germ agglutinin (WGA) staining. Cell proliferation and apoptosis were assessed via immunofluorescence with PH3 and TUNEL. RNA sequencing was performed on ctdsp2^−/− embryos and control siblings, followed by rescue experiments. Knockout of ctdsp2 in zebrafish resulted in craniofacial defects characteristic of HFM. We observed abnormalities in NCC apoptosis and proliferation in the pharyngeal arches, as well as impaired differentiation of chondrocytes in ctdsp2^−/− embryos. RNA-Seq analysis revealed significantly higher expression of genes in the p53 signaling pathway in mutants. Furthermore, ctdsp2 mRNA injection and tp53 knockout significantly rescued pharyngeal arch cartilage dysplasia. Our findings suggest that ctdsp2 knockout induces zebrafish craniofacial dysplasia, primarily by disrupting pharyngeal chondrocyte differentiation and inhibiting NCC proliferation through p53 signaling pathway activation. Full article

Osteoarthritis (OA) is the most common rheumatologic disease and a major cause of pain and disability in older adults. No efficient treatment is currently available. Mitochondrial dysfunction in chondrocytes drives molecular dysregulation in OA pathogenesis. Recently, mitochondrial transfer to chondrocytes had been described, enabling transplant of mitochondria as a new avenue to modify the OA process, although evidence on its feasibility and safety remains limited.The primary objective of this study was to demonstrate the feasibility and safety of intra-articular mitochondrial transplantation. Mitochondria were isolated from liver using the procedure described by Preble and coworkers combined with magnetic beads coupled to anti-TOM22 antibodies. The organelles obtained were analyzed to determine their purity and viability. The safety and viability of the administration of the isolated mitochondria into articular tissues as well as the integration and distribution of the transplanted mitochondria within joint tissues were analyzed using both in vitro and in vivo models. We established an efficient, reproducible, effective, and rapid protocol for isolating mitochondria from liver. We obtained mitochondria with high viability, yield, and purity. The isolated mitochondria were injected into joint tissue using both in vitro and in vivo models. Functional mitochondria were detected in the extracellular matrix of the cartilage, menisci and synovium. Our results establish a safe and viable protocol for mitochondrial isolation and intra-articular injection. The methodology and findings presented here pave the way for future studies in osteoarthritis models to validate mitochondrial transplantation as a potentially effective treatment for OA. Full article

In the context of bone fractures, the influence of the mechanical environment on the healing outcome is widely accepted, while its influence at the cellular level is still poorly understood. This study explores the influence of mechanical load on naïve mesenchymal stem cell (MSC) differentiation, focusing on hypertrophic chondrocyte differentiation. Unlike primary bone healing, which involves the direct differentiation of MSCs into bone-forming cells, endochondral ossification uses an intermediate cartilage template that remodels into bone. A high-throughput uniaxial bioreactor system (StrainBot) was used to apply varying percentages of strain on naïve MSCs encapsulated in GelMa hydrogels. This research shows that cyclic uniaxial compression alone directs naïve MSCs towards a hypertrophic chondrocyte phenotype. This was demonstrated by increased cell volumes and reduced glycosaminoglycan (GAG) production, along with an elevated expression of hypertrophic markers such as MMP13 and Type X collagen. In contrast, Type II collagen, typically associated with resting chondrocytes, was poorly detected under mechanical loading alone conditions. The addition of chondrogenic factor TGFβ1 in the culture medium altered these outcomes. TGFβ1 induced chondrogenic differentiation, as indicated by higher GAG/DNA production and Type II collagen expression, overshadowing the effect of mechanical loading. This suggests that, under mechanical strain, hypertrophic differentiation is hindered by TGFβ1, while chondrogenesis is promoted. Biochemical analyses further confirmed these findings. Mechanical deformation alone led to a larger cell size and a more rounded cell morphology characteristic of hypertrophic chondrocytes, while lower GAG and proteoglycan production was observed. Immunohistology staining corroborated the gene expression data, showing increased Type X collagen with mechanical strain. Overall, this study indicates that mechanical loading alone drives naïve MSCs towards a hypertrophic chondrocyte differentiation path. These insights underscore the critical role of mechanical forces in MSC differentiation and have significant implications for bone healing, regenerative medicine strategies and rehabilitation protocols. Full article