University of California, San Diego School of Medicine, La Jolla.
University of Texas at Austin.
Arthritis Rheumatol. 2016 Jul;68(7):1614-26. doi: 10.1002/art.39608.
Up-regulation of glucose metabolism has been implicated not only in tumor cell growth but also in immune cells upon activation. However, little is known about the metabolite profile in rheumatoid arthritis (RA), particularly in fibroblast-like synoviocytes (FLS). This study was undertaken to evaluate whether changes in glucose metabolism in RA FLS could play a role in inflammation and joint damage.
Synovium and FLS were obtained from patients with RA and patients with osteoarthritis (OA). The rate of glycolysis after stimulation of FLS with lipopolysaccharide and platelet-derived growth factor BB was measured using glycolysis stress test technology. FLS function was evaluated using a glycolysis inhibitor, 2-deoxy-d-glucose (2-DG). After stimulation of the FLS, a migration scratch assay, MTT assay, and enzyme-linked immunosorbent assay were performed to measure the effect of 2-DG on FLS migration, viability of the FLS, and cytokine secretion, respectively. IRDye 800CW 2-DG was used to assess glucose uptake in the arthritic joints and stromal cells of mice after K/BxN mouse serum transfer. The mice were injected daily, intraperitoneally, with 3-bromopyruvate (BrPa; 5 mg/kg) to assess the effect of inhibition of glycolysis in vivo.
Compared to human OA FLS, the balance between glycolysis and oxidative phosphorylation was shifted toward glycolysis in RA FLS. Glucose transporter 1 (GLUT1) messenger RNA (mRNA) expression correlated with baseline functions of the RA FLS. Glucose deprivation or incubation of the FLS with glycolytic inhibitors impaired cytokine secretion and decreased the rate of proliferation and migration of the cells. In a mouse model of inflammatory arthritis, GLUT1 mRNA expression in the synovial lining cells was observed, and increased levels of glucose uptake and glycolytic gene expression were detected in the stromal compartment of the arthritic mouse joints. Inhibition of glycolysis by BrPa, administered in vivo, significantly decreased the severity of arthritis in this mouse model.
Targeting metabolic pathways is a novel approach to understanding the mechanisms of disease. Inhibition of glycolysis may directly modulate synoviocyte-mediated inflammatory functions and could be an effective treatment strategy for arthritis.
葡萄糖代谢的上调不仅与肿瘤细胞的生长有关，而且与激活后的免疫细胞有关。然而，对于类风湿关节炎（RA）中代谢物谱的了解甚少，特别是在成纤维样滑膜细胞（FLS）中。本研究旨在评估 RA FLS 中葡萄糖代谢的变化是否在炎症和关节损伤中起作用。
从 RA 患者和骨关节炎（OA）患者的滑膜和 FLS 中获取。使用糖酵解应激测试技术测量 FLS 在用脂多糖和血小板衍生生长因子 BB 刺激后的糖酵解率。使用糖酵解抑制剂 2-脱氧-D-葡萄糖（2-DG）评估 FLS 的功能。刺激 FLS 后，进行迁移划痕试验、MTT 试验和酶联免疫吸附试验，分别测量 2-DG 对 FLS 迁移、FLS 活力和细胞因子分泌的影响。IRDye 800CW 2-DG 用于评估 K/BxN 小鼠血清转移后关节炎关节和基质细胞中的葡萄糖摄取。每天通过腹腔内注射 3-溴丙酮酸（BrPa；5mg/kg）来评估体内抑制糖酵解的效果。
与人类 OA FLS 相比，RA FLS 中的糖酵解和氧化磷酸化之间的平衡向糖酵解倾斜。葡萄糖转运蛋白 1（GLUT1）信使 RNA（mRNA）表达与 RA FLS 的基线功能相关。葡萄糖剥夺或用糖酵解抑制剂孵育 FLS 会损害细胞因子的分泌并降低细胞的增殖和迁移速度。在炎症性关节炎的小鼠模型中，观察到滑膜衬里细胞中的 GLUT1 mRNA 表达，并在关节炎小鼠关节的基质隔室中检测到葡萄糖摄取和糖酵解基因表达水平的增加。体内给予 BrPa 抑制糖酵解可显著降低该小鼠模型的关节炎严重程度。
靶向代谢途径是理解疾病机制的一种新方法。抑制糖酵解可能直接调节滑膜细胞介导的炎症功能，并且可能是关节炎的有效治疗策略。
