Xiong Liwei
Department of Orthopaedics, Nanchang People's Hospital (The Third Hospital of Nanchang), Nanchang City, Jiangxi Province, China.
Nanchang People's Hospital (The Third Hospital of Nanchang), No. 2, Xiangshan South Road, Nanchang City, Jiangxi Province, 330003, China.
Glycoconj J. 2025 Feb;42(1):41-52. doi: 10.1007/s10719-024-10176-5. Epub 2025 Jan 11.
Reduction of glucose transporter 1 (GLUT1), even deletion, may results in cartilage fibrosis and osteoarthritis. This study aims to investigate the SUMOylation of GLUT1 in osteoarthritis through small ubiquitin-like modifier 1(SUMO1), and explore the role of SUMOylated GLUT1 in glycometabolism, proliferation and apoptosis in chondrocytes. Human chondrocytes were incubated with 10 ng/mL of IL-1β to mimic osteoarthritis in vitro. GLUT1, SUMO1 and Chondrocyte-related genes including COL2A1, MMP13 and ADAMTS4 were evaluated using western blot. Cell viability and cell apoptosis of chondrocytes were measured by cell counting kit-8 assay and flow cytometry, respectively. The changes in glycometabolism were evaluated using extracellular acidification rate (ECAR) and glucose uptake assay. Co-immunoprecipitation (Co-IP) was used to verify the interaction between GLUT1 and SUMO1. The stabilization role of SUMO1 in GLUT1 was determined by cycloheximide assay. IL-1β induced the decrease of GLUT1, cell viability, ECAR, glucose uptake and COL2A1 and the increase of cell apoptosis, MMP13 and ADAMTS4 in chondrocytes. However, overexpression of SUMO1 led to the reduction of cell apoptosis, MMP13 and ADAMTS4 and the elevation of GLUT1, cell viability, ECAR, glucose uptake and COL2A1 in IL-1β-stimulated chondrocytes. There was SUMOylation sites on GLUT1. Intriguingly, SUMO1 was significantly enriched in GLUT1 using Co-IP assay, and stabilized GLUT1 in chondrocytes. SUMO1-mediated SUMOylation is capable of stabilizing GLUT1 to inhibit glycometabilsm disorder and cell apoptosis in IL-1β-stimulated chondrocytes.
葡萄糖转运蛋白1（GLUT1）水平降低甚至缺失可能导致软骨纤维化和骨关节炎。本研究旨在通过小泛素样修饰物1（SUMO1）探讨骨关节炎中GLUT1的SUMO化修饰，并探究SUMO化修饰的GLUT1在软骨细胞糖代谢、增殖和凋亡中的作用。体外将人软骨细胞与10 ng/mL白细胞介素-1β（IL-1β）共同孵育以模拟骨关节炎。采用蛋白质免疫印迹法检测GLUT1、SUMO1以及包括Ⅱ型胶原α1链（COL2A1）、基质金属蛋白酶13（MMP13）和含血小板反应蛋白基序的解聚素样金属蛋白酶4（ADAMTS4）在内的软骨细胞相关基因。分别采用细胞计数试剂盒-8法和流式细胞术检测软骨细胞的活力和凋亡情况。通过细胞外酸化率（ECAR）和葡萄糖摄取试验评估糖代谢变化。采用免疫共沉淀法（Co-IP）验证GLUT1与SUMO1之间的相互作用。用放线菌酮试验确定SUMO1对GLUT1的稳定作用。IL-1β可导致软骨细胞中GLUT1、细胞活力、ECAR、葡萄糖摄取及COL2A1水平降低，细胞凋亡、MMP13及ADAMTS4水平升高。然而，SUMO1过表达可使IL-1β刺激的软骨细胞中细胞凋亡、MMP13及ADAMTS4水平降低，GLUT1、细胞活力、ECAR、葡萄糖摄取及COL2A1水平升高。GLUT1存在SUMO化修饰位点。有趣的是，Co-IP试验显示SUMO1在GLUT1中显著富集，并在软骨细胞中稳定GLUT1。SUMO1介导的SUMO化修饰能够稳定GLUT1，从而抑制IL-1β刺激的软骨细胞中的糖代谢紊乱和细胞凋亡。
