From dysfunction to healing: advances in mitochondrial therapy for Osteoarthritis

Implications of obesity-mediated cellular dysfunction and adipocytokine signaling pathways in the pathogenesis of osteoarthritis

Osteoarthritis (OA) is a degenerative joint disease characterized by cartilage degradation, bone sclerosis, and chronic low-grade inflammation. Aging and injury play key roles in OA pathogenesis by triggering the release of proinflammatory factors from adipose tissue and other sources. Obesity and aging impair the function of endoplasmic reticulum (ER) chaperones, leading to ER stress, protein misfolding, and cellular apoptosis. Obesity also induces mitochondrial dysfunction in OA through oxidative stress and disrupts mitochondrial dynamics, exacerbating chondrocyte damage. These factors contribute to inflammation, matrix imbalance, and chondrocyte apoptosis. Adipocytes, the primary source of adipokines, release inflammatory mediators that affect joint cells. Several adipocytokines have a central role in the regulation of many aspects of inflammation. Adiponectin and leptin are the two most abundant adipocytokines that are strongly associated with OA progression. This literature review suggests that adipokines activate many signaling pathways to exert downstream effects and play significant roles in obesity-induced OA. Understanding this rapidly growing family of mainly adipocyte-derived mediators and obesity-mediated cellular dysfunction may be important in the development of new therapies for obesity-associated OA management.

Targeting p21-Positive Senescent Chondrocytes via IL-6R/JAK2 Inhibition to Alleviate Osteoarthritis

Osteoarthritis (OA) is an age-related degenerative joint disease, prominently influenced by the pro-inflammatory cytokine interleukin-6 (IL-6). Although elevated IL-6 levels in joint fluid are well-documented, the uneven cartilage degeneration observed in knee OA patients suggests additional underlying mechanisms. This study investigates the role of interleukin-6 receptor (IL-6R) in mediating IL-6 signaling and its contribution to OA progression. Here, significantly elevated IL-6R expression is identified in degenerated cartilage of OA patients. Further, in vivo experiments reveal that intra-articular injection of recombinant IL-6R protein or activation of gp130 (Y757F mutation) accelerates OA progression. Conversely, knockout of IL-6R or JAK2, as well as treatment with a JAK inhibitor, alleviates OA symptoms. Mechanistically, chondrocytes derived from degenerative cartilage exhibit impaired nuclear localization of SOX9, a key regulator of cartilage homeostasis. JAK inhibition stabilizes SIRT1, reduces SOX9 acetylation, and thereby facilitates SOX9 nuclear localization, promoting cartilage repair. Additionally, the JAK inhibitor-induced apoptosis in p21-positive senescent cells, and their targeted clearance successfully alleviates OA in p21-3MR mice. In conclusion, these findings reveal a novel mechanism by which inhibiting the IL-6R/JAK2 pathway can alleviate OA. Furthermore, this study proposes targeting p21-positive senescent cells as a new therapeutic strategy for OA.

Potential Chondroprotective Effect of Artemisia annua L. Water Extract on SW1353 Cell

Inflammation plays a critical role in the pathogenesis of osteoarthritis (OA). The objective of this study was to investigate the anti-inflammatory and chondroprotective properties of Artemisia annua L. water extract (AWE) following the induction of inflammation in cartilage cells (SW1353 cell) through the administration of interleukin-1 beta (IL-1β). We demonstrated significant antioxidant activity, as evidenced by elevated total phenolic and flavonoid content, in addition to robust free radical scavenging capacity, as assessed through DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) assays. Its cytotoxic effects were assessed at a concentration of 200 μg/mL, where no cytotoxic signs were observed in SW1353 cells treated with IL-1β; the levels of reactive oxygen species (ROS) were notably reduced in a dose-dependent manner. The principal inflammatory markers, cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS), were significantly diminished by AWE treatment. AWE administration led to a dose-dependent reduction in the expression of key proteins involved in the mitogen-activated protein kinase (MAPK) and nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) signaling pathways, ultimately resulting in a decrease in the release of matrix metalloproteinases (MMPs), specifically MMP-1 and MMP-13, which are known to contribute to cartilage degradation. Additionally, the levels of degraded collagen type II in the cartilage cells were restored. These findings suggest that reducing oxidative stress and inflammation, along with inhibiting activated MAPK and NF-κB signaling pathways, may ameliorate the progression of IL-1β-induced OA. Furthermore, a molecular docking analysis revealed a strong binding affinity of MMP-13, a critical mediator in the pathogenesis of OA. Six compounds were identified in AWE, corroborating its potential antioxidant and anti-inflammatory effects. Therefore, AWE may serve as a potentially useful therapeutic agent against OA by modulating inflammation-related mechanisms.

Recent development of mitochondrial metabolism and dysfunction in osteoarthritis

Osteoarthritis is a degenerative joint disorder characterized by cartilage degradation, synovial inflammation, and altered subchondral bone structure. Recent insights have identified mitochondrial dysfunction as a pivotal factor in OA pathogenesis, contributing to chondrocyte apoptosis, oxidative stress, and extracellular matrix degradation. Disruptions in mitochondrial dynamics, including impaired biogenesis, mitophagy, and metabolic shifts from oxidative phosphorylation to glycolysis, exacerbate cartilage damage by promoting the production of reactive oxygen species and matrix-degrading enzymes such as ADAMTS and MMPs. This review explores the molecular mechanisms underlying mitochondrial dysfunction in OA, emphasizing its role in cartilage homeostasis and inflammation. Furthermore, it highlights emerging therapeutic strategies targeting mitochondrial pathways, including antioxidants, mitophagy enhancers, and metabolic modulators, as potential interventions to mitigate disease progression, which offer promising avenues for advancing personalized and disease-modifying treatments in OA.

About the ozone ability in using adaptive chaos to restore a healthy state in the oxygen-ozone adjunct therapy

The action of ozone in medicine is a subject of interest and lively, controversial debates. Its mechanisms of action are still far from fully understood. However, it is possible that ozone triggers a series of dynamics in living organisms related to chaos, multi-stable phenomena, and oscillatory processes. Ozone may be involved in adaptive chaos. Adaptive chaos in health and the reduction of complexity in pathology are interconnected phenomena that describe the functional dynamics of biological systems. Adaptive chaos refers to a state of controlled, complex, and flexible behaviour exhibited by healthy biological systems. It allows for a dynamic balance between order and unpredictability, enabling the system to respond to various internal and external stimuli. In pathological states, the system loses its adaptive chaos, often becoming either too rigid or overly chaotic. This reduction in complexity limits the ability of the system to respond effectively to stimuli, making it prone to dysfunction. This paper addresses the role of ozone in these scenarios.