Department of Orthopedics, The First Affiliated Hospital of Anhui Medical University, #218 Jixi Road, Hefei, 230022, China.
Department of Orthopedics, The FuYang Affiliated Hospital of Anhui Medical University, #99 Huangshan Road, FuYang, 236000, China.
Sci Rep. 2022 Jul 13;12(1):11957. doi: 10.1038/s41598-022-16093-7.
Strategies for treating osteoarthritis (OA) have become a research focus because an effective treatment for OA is unavailable. The objective of this study was to explore the effects and underlying mechanisms of glutamine (Gln) in OA. First, the chondrocytes were identified and a standard IL-1β-induced OA model was established. After treatment with Gln or saline, the viability and apoptosis of chondrocytes were evaluated using a CCK-8 assay and flow cytometry analysis, which revealed that Gln can improve the IL-1β-induced OA cells. Meanwhile, Gln can enhance the expression of aggrecan and collagen II, which are protective proteins for articular cartilage. Instead, Gln inhibited the expression of matrix metalloproteinase-1 (MMP-1) and matrix metalloproteinase-13 (MMP-13), which can degrade cartilage. To better understand the underlying mechanisms of Gln in IL-1β-induced chondrocytes, the classical OA pathways of JNK and NF-κB were examined at the protein and mRNA levels using western blot and qRT-PCR analyses. We found that JNK and NF-κB were downregulated gradually depending on the Gln dose and protective and destructive factors changed based on changes of JNK and NF-κB. The effects of high-dose Gln were more effective than low-dose. Moreover, Gln was applied to the animal OA model to check the effects in vivo. The results showed that Gln attenuated cartilage degeneration and decreased OARSI scores, which demonstrated that Gln can improve OA. The experiments showed that Gln can benefit mice with OA by inhibiting the JNK and NF-κB signaling pathways.
治疗骨关节炎 (OA) 的策略已成为研究重点，因为目前尚无有效的 OA 治疗方法。本研究旨在探讨谷氨酰胺 (Gln) 治疗 OA 的作用及机制。首先，鉴定软骨细胞并建立标准的 IL-1β诱导的 OA 模型。用 Gln 或生理盐水处理后，通过 CCK-8 测定和流式细胞术分析评估软骨细胞的活力和凋亡，结果表明 Gln 可以改善 IL-1β诱导的 OA 细胞。同时，Gln 可以增强聚集蛋白聚糖和胶原 II 的表达，这两种蛋白都是关节软骨的保护蛋白。相反，Gln 抑制基质金属蛋白酶-1 (MMP-1) 和基质金属蛋白酶-13 (MMP-13) 的表达，这两种酶可以降解软骨。为了更好地了解 Gln 在 IL-1β诱导的软骨细胞中的作用机制，使用 Western blot 和 qRT-PCR 分析在蛋白和 mRNA 水平上检查了经典的 OA 通路 JNK 和 NF-κB。我们发现 JNK 和 NF-κB 随着 Gln 剂量的增加而逐渐下调，保护和破坏因子根据 JNK 和 NF-κB 的变化而变化。高剂量 Gln 的作用比低剂量更有效。此外，将 Gln 应用于动物 OA 模型以检查体内的作用。结果表明 Gln 可以减轻软骨退变并降低 OARSI 评分，表明 Gln 可以改善 OA。实验表明，通过抑制 JNK 和 NF-κB 信号通路，Gln 可以使 OA 小鼠受益。
