Strontium ion attenuates osteoarthritis through inhibiting senescence and enhancing autophagy in fibroblast-like synoviocytes

Cross-talk of inflammation and cellular senescence: a new insight into the occurrence and progression of osteoarthritis

Osteoarthritis (OA) poses a significant challenge in orthopedics. Inflammatory pathways are regarded as central mechanisms in the onset and progression of OA. Growing evidence suggests that senescence acts as a mediator in inflammation-induced OA. Given the lack of effective treatments for OA, there is an urgent need for a clearer understanding of its pathogenesis. In this review, we systematically summarize the cross-talk between cellular senescence and inflammation in OA. We begin by focusing on the mechanisms and hallmarks of cellular senescence, summarizing evidence that supports the relationship between cellular senescence and inflammation. We then discuss the mechanisms of interaction between cellular senescence and inflammation, including senescence-associated secretory phenotypes (SASP) and the effects of pro- and anti-inflammatory interventions on cellular senescence. Additionally, we focus on various types of cellular senescence in OA, including senescence in cartilage, subchondral bone, synovium, infrapatellar fat pad, stem cells, and immune cells, elucidating their mechanisms and impacts on OA. Finally, we highlight the potential of therapies targeting senescent cells in OA as a strategy for promoting cartilage regeneration.

Nutritional Strategies for Chronic Craniofacial Pain and Temporomandibular Disorders: Current Clinical and Preclinical Insights

This narrative review provides an overview of current knowledge on the impact of nutritional strategies on chronic craniofacial pain associated with temporomandibular disorders (TMDs). Individuals experiencing painful TMDs alter their dietary habits, avoiding certain foods, possibly due to chewing difficulties, which might lead to nutrient deficiencies. Our literature investigation revealed that the causal links between nutritional changes and craniofacial pain remain unclear. However, clinical and preclinical studies suggest that nutraceuticals, including vitamins, minerals, polyphenols, omega-3 fatty acids, isoprenoids, carotenoids, lectins, polysaccharides, glucosamines, and palmitoylethanolamides, could have beneficial effects on managing TMDs. This is described in 12 clinical and 38 preclinical articles since 2000. Clinical articles discussed the roles of vitamins, minerals, glucosamine, and palmitoylethanolamides. The other nutraceuticals were assessed solely in preclinical studies, using TMD models, mostly craniofacial inflammatory rodents, with 36 of the 38 articles published since 2013. Our investigation indicates that current evidence is insufficient to assess the efficacy of these nutraceuticals. However, the existing data suggest potential for therapeutic intervention in TMDs. Further support from longitudinal and randomized controlled studies and well-designed preclinical investigations is necessary to evaluate the efficacy of each nutraceutical intervention and understand their underlying mechanisms in TMDs.

Non-coding RNAs as regulators of autophagy in chondrocytes: Mechanisms and implications for osteoarthritis

Osteoarthritis (OA) is a chronic degenerative joint disease with multiple causative factors such as aging, mechanical injury, and obesity. Autophagy is a complex dynamic process that is involved in the degradation and modification of intracellular proteins and organelles under different pathophysiological conditions. Autophagy, as a cell survival mechanism under various stress conditions, plays a key role in regulating chondrocyte life cycle metabolism and cellular homeostasis. Non-coding RNAs (ncRNAs) are heterogeneous transcripts that do not possess protein-coding functions, but they can act as effective post-transcriptional and epigenetic regulators of gene and protein expression, thus participating in numerous fundamental biological processes. Increasing evidence suggests that ncRNAs, autophagy, and their crosstalk play crucial roles in OA pathogenesis. Therefore, we summarized the complex role of autophagy in OA chondrocytes and focused on the regulatory role of ncRNAs in OA-associated autophagy to elucidate the complex pathological mechanisms of the ncRNA-autophagy network in the development of OA, thus providing new research targets for the clinical diagnosis and treatment of OA.

Luteolin regulating synthesis and catabolism of osteoarthritis chondrocytes via activating autophagy

Osteoarthritis (OA) is a prevalent bone and joint disease characterized by degeneration. The dysregulation between chondrocyte synthesis and breakdown is a key factor in OA development. Targeting the degenerative changes in cartilage tissue degradation could be a potential treatment approach for OA. Previous research has established a strong link between autophagy and the regulation of chondrocyte functions. Activating autophagy has shown promise in mitigating cartilage tissue degeneration. Currently, osteoarthritis treatment primarily focuses on symptom management, as there is no definitive medication to stop disease progression. Previous studies have demonstrated that luteolin, a flavonoid present in Chinese herbal medicine, can activate autophagy and reduce the expression of MMP1 and ADAMTS-5. This study utilized an in vitro osteoarthritis model with chondrocytes stimulated by IL-1β, treated with varying concentrations of luteolin. Treatment with luteolin notably increased the levels of synthesis factors Aggrecan and Collagen II, while decreasing the levels of decomposition factors MMP-1 and ADAMTS-5. Moreover, inhibition of autophagy by Chloroquine reversed the imbalances in chondrocyte activities induced by IL-1β. In an in vivo model of knee osteoarthritis induced by medial meniscal instability (DMM), luteolin was administered as a therapeutic regimen. After 12 weeks, knee cartilage tissues from mice were analyzed. Immunofluorescence and immunohistochemical staining revealed a decrease in P62 expression and an increase in Beclin-1 in the cartilage tissues. Additionally, cartilage wear in the knee joints of mice was alleviated by safranin O and fast green staining. Our study findings underscore the significant role of luteolin in effectively rebalancing chondrocyte activities disrupted by IL-1β. Our results strongly indicate that luteolin has the potential to be developed as a novel therapeutic agent for the treatment of osteoarthritis, offering promising prospects for future drug development.

WITHDRAWN: The dysregulated autophagy in osteoarthritis: Revisiting molecular profile

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