Table1_Epimedin C Alleviates Glucocorticoid-Induced Suppression of Osteogenic Differentiation by Modulating PI3K/AKT/RUNX2 Signaling Pathway.DOCX

Secondary osteoporosis is triggered mostly by glucocorticoid (GC) therapy. Dexamethasone (DEX) was reported to inhibit osteogenic differentiation in zebrafish larvae and MC3T3-E1 cells in prior research. In this research, we primarily examined the protective impacts of epimedin C on the osteogenic inhibition impact of MC3T3-E1 cells and zebrafish larvae mediated by DEX. The findings illustrated no apparent toxicity for MC3T3-E1 cells after administering epimedin C at increasing dosages from 1 to 60 μM and no remarkable proliferation in MC3T3-E1 cells treated using DEX. In MC3T3-E1 cells that had been treated using DEX, we discovered that epimedin C enhanced alkaline phosphatase activities and mineralization. Epimedin C could substantially enhance the protein expression of osterix (OSX), Runt-related transcription factor 2 (RUNX2), and alkaline phosphatase (ALPL) in MC3T3-E1 cells subjected to DEX treatment. Additionally, epimedin C stimulated PI3K and AKT signaling pathways in MC3T3-E1 cells that had been treated using DEX. Furthermore, in a zebrafish larvae model, epimedin C was shown to enhance bone mineralization in DEX-mediated bone impairment. We also found that epimedin C enhanced ALPL activity and mineralization in MC3T3-E1 cells treated using DEX, which may be reversed by PI3K inhibitor (LY294002). LY294002 can also reverse the protective impact of epimedin C on DEX-mediated bone impairment in zebrafish larval. These findings suggested that epimedin C alleviated the suppressive impact of DEX on the osteogenesis of zebrafish larval and MC3T3-E1 cells via triggering the PI3K and AKT signaling pathways. Epimedin C has significant potential in the development of innovative drugs for the treatment of glucocorticoid-mediated osteoporosis.

继发性骨质疏松症主要由糖皮质激素（GC）治疗引发。既往研究表明，地塞米松（DEX）能够抑制斑马鱼幼鱼和MC3T3-E1细胞的成骨分化。在本研究中，我们主要探讨了埃皮美丁C对DEX介导的MC3T3-E1细胞和斑马鱼幼鱼成骨抑制作用的保护性影响。研究结果揭示了在1至60微摩尔递增剂量下给予埃皮美丁C后，对MC3T3-E1细胞无明显毒性，并且DEX处理的MC3T3-E1细胞无显著增殖。在DEX处理的MC3T3-E1细胞中，我们发现埃皮美丁C增强了碱性磷酸酶活性和矿化。埃皮美丁C能够显著提高受DEX处理的MC3T3-E1细胞中成骨素（OSX）、RUNX2转录因子2（RUNX2）和碱性磷酸酶（ALPL）的蛋白质表达。此外，埃皮美丁C刺激了DEX处理的MC3T3-E1细胞中的PI3K和AKT信号通路。进一步地，在DEX介导的骨损伤斑马鱼幼鱼模型中，埃皮美丁C被证明可以增强骨矿化。我们还发现，埃皮美丁C增强了DEX处理的MC3T3-E1细胞中的ALPL活性和矿化，这一效应可能被PI3K抑制剂（LY294002）逆转。LY294002还可以逆转埃皮美丁C对DEX介导的斑马鱼幼鱼骨损伤的保护作用。这些发现表明，埃皮美丁C通过触发PI3K和AKT信号通路减轻了DEX对斑马鱼幼鱼和MC3T3-E1细胞成骨的抑制作用。埃皮美丁C在开发治疗糖皮质激素介导的骨质疏松症的创新药物方面具有显著潜力。