Comprehensive in vitro and in vivo investigations of the therapeutic potential of Jeju lava seawater salt in osteoarthritis

Abstract Salts play a crucial role in maintaining human health by regulating fluid levels and supporting various physiological processes. However, conventional seawater-derived salts are associated with microplastic pollution and pose potential health risks. Jeju lava seawater (JLS), sourced exclusively from Jeju Island, has emerged as a unique alternative, free of microplastics and enriched with essential minerals such as magnesium, calcium, zinc, and iron. In this study, we investigated the effects of JLS on osteoarthritis (OA) pathogenesis, focusing on chondrocyte metabolism and OA development. We performed surgical destabilization of the medial meniscus to establish a murine model of OA. We examined the expression of catabolic and anabolic factors in JLS-treated chondrocytes. Our cell viability assay revealed that JLS treatment was not cytotoxic to chondrocytes at concentrations ≤ 0.5%. Additionally, JLS treatment resulted in a concentration-dependent increase in the expression of anabolic factors like aggrecan, SOX9, and COL2A1 while decreasing the expression of catabolic factors such as MMP3, MMP13, ADAMTS4, and ADAMTS5 in the chondrocytes stimulated with pro-inflammatory cytokines. Although not statistically significant compared to the control group, JLS intake slightly attenuated the OARSI score, osteophyte score, synovitis score, subchondral bone thickness, and osteophyte size in the  mouse model of OA. Conclusively, these results suggest that JLS ameliorates OA by positively influencing chondrocyte metabolism, making it a promising therapeutic candidate for OA management

Functional selectivity of insulin receptor revealed by aptamer-trapped receptor structures

Activation of insulin receptor (IR) initiates a cascade of conformational changes and autophosphorylation events. Herein, we determined three structures of IR trapped by aptamers using cryo-electron microscopy. The A62 agonist aptamer selectively activates metabolic signaling. In the absence of insulin, the two A62 aptamer agonists of IR adopt an insulin-accessible arrowhead conformation by mimicking site-1/site-2' insulin coordination. Insulin binding at one site triggers conformational changes in one protomer, but this movement is blocked in the other protomer by A62 at the opposite site. A62 binding captures two unique conformations of IR with a similar stalk arrangement, which underlie Tyr1150 mono-phosphorylation (m-pY1150) and selective activation for metabolic signaling. The A43 aptamer, a positive allosteric modulator, binds at the opposite side of the insulin-binding module, and stabilizes the single insulin-bound IR structure that brings two FnIII-3 regions into closer proximity for full activation. Our results suggest that spatial proximity of the two FnIII-3 ends is important for m-pY1150, but multi-phosphorylation of IR requires additional conformational rearrangement of intracellular domains mediated by coordination between extracellular and transmembrane domains. DNA aptamers can activate insulin receptor as selective agonists or positive allosteric modulators. Here, authors determine structures of the insulin receptor bound to aptamers and provide a basis for the selective activation or allosteric regulation of insulin receptor.11Ysciescopu

GSK5182, 4-Hydroxytamoxifen Analog, a New Potential Therapeutic Drug for Osteoarthritis

Estrogen-related receptors (ERRs) are the first identified orphan nuclear receptors. The ERR family consists of ERRα, ERRβ, and ERRγ, regulating diverse isoform-specific functions. We have reported the importance of ERRγ in osteoarthritis (OA) pathogenesis. However, therapeutic approaches with ERRγ against OA associated with inflammatory mechanisms remain limited. Herein, we examined the therapeutic potential of a small-molecule ERRγ inverse agonist, GSK5182 (4-hydroxytamoxifen analog), in OA, to assess the relationship between ERRγ expression and pro-inflammatory cytokines in mouse articular chondrocyte cultures. ERRγ expression increased following chondrocyte exposure to various pro-inflammatory cytokines, including interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α. Pro-inflammatory cytokines dose-dependently increased ERRγ protein levels. In mouse articular chondrocytes, adenovirus-mediated ERRγ overexpression upregulated matrix metalloproteinase (MMP)-3 and MMP-13, which participate in cartilage destruction during OA. Adenovirus-mediated ERRγ overexpression in mouse knee joints or ERRγ transgenic mice resulted in OA. In mouse joint tissues, genetic ablation of Esrrg obscured experimental OA. These results indicate that ERRγ is involved in OA pathogenesis. In mouse articular chondrocytes, GSK5182 inhibited pro-inflammatory cytokine-induced catabolic factors. Consistent with the in vitro results, GSK5182 significantly reduced cartilage degeneration in ERRγ-overexpressing mice administered intra-articular Ad-Esrrg. Overall, the ERRγ inverse agonist GSK5182 represents a promising therapeutic small molecule for OA

Inhibitory effects of Ganoderma lucidum spore oil on rheumatoid arthritis in a collagen-induced arthritis mouse model

Holistic healthcare practitioners have now started to focus on specific traditional medicinal mushrooms to treat rheumatoid arthritis (RA). Ganoderma lucidum (GL) is one of the oldest mushrooms that have been used in ancient Chinese medicine to treat inflammatory ailments, including autoimmune diseases such as RA. Spores from this mushroom have specific effects on immunomodulation, aging, and cancer. However, the effect of G. lucidum spores (GLS) on arthritis remains unclear. Therefore, we investigated the effects of GLS oil in a collagen-induced rheumatoid arthritis (CIA) model. Metabolomics analysis revealed that GLS oil contains ten acids, of which oleic acid (52.12%) and linoleic acid (16.77%) predominated. The GLS oil-treated CIA mice had a significantly lower clinical score (p = 0.0384) for RA than the control CIA mice. Moreover, GLS oil reduced CIA-induced cartilage degeneration and synovial membrane inflammation in the knee. The GLS oil group showed significantly reduced knee eosinophilia (p = 0.0056). Immunostaining of neutrophils revealed that neutrophils infiltrated the CIA group; however, infiltrated neutrophils were significantly reduced in the GLS oil group in both the knees (p = 0.0006) and ankles (p = 0.0023). GLS oil treatment substantially suppressed LPS- or TNF-α–induced IL-6 mRNA expression in primary cultured chondrocytes. IL-6 immunohistochemistry results showed that the protein levels of IL-6 were attenuated in the GLS oil group compared to the CIA group. These findings suggest that GLS oil may be useful for the development of RA drugs. Further clinical research is required to identify significant improvements

Innate Immune Response Analysis in Meniscus Xenotransplantation Using Normal and Triple Knockout Jeju Native Pigs

Although allogenic meniscus grafting can be immunologically safe, it causes immune rejection due to an imbalanced tissue supply between donor and recipient. Pigs are anatomically and physiologically similar to adult humans and are, therefore, considered to be advantageous xenotransplantation models. However, immune rejection caused by genetic difference damages the donor tissue and can sometimes cause sudden death. Immune rejection is caused by genes; porcine GGTA1, CMAH, and B4GLANT2 are the most common. In this study, we evaluated immune cells infiltrating the pig meniscus transplanted subcutaneously into BALB/c mice bred for three weeks. We compared the biocompatibility of normal Jeju native black pig (JNP) meniscus with that of triple knockout (TKO) JNP meniscus (α-gal epitope, N-glycolylneuraminic acid (Neu5Gc), and Sd (a) epitope knockout using CRISPR-Cas 9). Mast cells, eosinophils, neutrophils, and macrophages were found to have infiltrated the transplant boundary in the sham (without transplantation), normal (normal JNP), and test (TKO JNP) samples after immunohistochemical analysis. When compared to normal and sham groups, TKO was lower. Cytokine levels did not differ significantly between normal and test groups. Because chronic rejection can occur after meniscus transplantation associated with immune cell infiltration, we propose studies with multiple genetic editing to prevent immune rejection