Intra-Articular Lactate Dehydrogenase A Inhibitor Oxamate Reduces Experimental Osteoarthritis and Nociception in Rats via Possible Alteration of Glycolysis-Related Protein Expression in Cartilage Tissue

Intra-articular injection of modified citrus pectin and hyaluronate gel induces synergistic effects in treating osteoarthritis

We previously found that modified citrus pectin (MCP), an inhibitor of pro-inflammatory factor Galectin-3 (Gal-3), has significant anti-inflammatory and chondroprotective effects. In this study, a hyaluronate (HA) gel-based sustained release system of MCP (MCP-HA) was developed as an anti-inflammatory agent for chronic inflammation for osteoarthritis (OA) treatment. The MCP-HA gel was injected into the knee joint cavities of OA rabbit models induced by anterior cruciate ligament transection (ACLT) or modified Hulth method once a week for five weeks. We found that MCP-HA could improve the symptoms and signs of OA, protect articular cartilage from degeneration, suppress synovial inflammation, and therefore alleviate OA progression. Proteomic analysis of the synovial fluid obtained from the knee joints of OA rabbits revealed that MCP-HA synergistically regulated the levels of multiple inflammatory mediators and proteins involved in metabolic pathways. Taken together, our results demonstrate that the MCP-HA shows a synergistic effect of HA and MCP by modulating both inflammation and metabolic processes, thereby alleviating OA progression. The MCP-HA sustained release system has promising potential for long-term use in OA treatment.

Sirtuin 1 in osteoarthritis: Perspectives on regulating glucose metabolism

Osteoarthritis (OA) is a degenerative disease characterised by articular cartilage destruction, and its complex aetiology contributes to suboptimal clinical treatment outcomes. A close association exists between glucose metabolism dysregulation and OA pathogenesis. Owing to the unique environment of low oxygen and glucose concentrations, chondrocytes rely heavily on their glycolytic capacity, exhibiting distinct spatiotemporal differences. However, under pathological stimulation, chondrocytes undergo excessive glycolytic activity while mitochondrial respiration and other branches of glucose metabolism are compromised. This metabolic change induces cartilage degeneration by reprogramming the inflammatory responses. Sirtuins, a highly conserved family of nicotinamide adenine dinucleotide (NAD+)-dependent deacetylases, regulate glucose metabolism in response to energy fluctuations in different cellular compartments，alleviating metabolic stress. SIRT1, the most extensively studied sirtuin, participates in maintaining glucose homeostasis in almost all key metabolic tissues. While actively contributing to the OA progression and displaying diverse biological effects in cartilage protection, SIRT1's role in regulating glucose metabolism in chondrocytes has not received sufficient attention. This review focuses on discussing the beneficial role of SIRT1 in OA progression from a metabolic regulation perspective based on elucidating the primary characteristics of chondrocyte glucose metabolism. We also summarise the potential mechanisms and therapeutic strategies targeting SIRT1 in chondrocytes to guide clinical practice and explore novel therapeutic directions.

Glycolysis: an emerging regulator of osteoarthritis

Osteoarthritis (OA) has been a leading cause of disability in the elderly and there remains a lack of effective therapeutic approaches as the mechanisms of pathogenesis and progression have yet to be elucidated. As OA progresses, cellular metabolic profiles and energy production are altered, and emerging metabolic reprogramming highlights the importance of specific metabolic pathways in disease progression. As a crucial part of glucose metabolism, glycolysis bridges metabolic and inflammatory dysfunctions. Moreover, the glycolytic pathway is involved in different areas of metabolism and inflammation, and is associated with a variety of transcription factors. To date, it has not been fully elucidated whether the changes in the glycolytic pathway and its associated key enzymes are associated with the onset or progression of OA. This review summarizes the important role of glycolysis in mediating cellular metabolic reprogramming in OA and its role in inducing tissue inflammation and injury, with the aim of providing further insights into its pathological functions and proposing new targets for the treatment of OA.