Maneix L, Beauchef G, Servent A, Wegrowski Y, Maquart F X, Boujrad N, Flouriot G, Pujol J P, Boumediene K, Galéra P, Moslemi S
Laboratory of Extracellular Matrix and Pathology, Faculty of Medicine, IFR 146 ICORE, University of Caener-Low Normandy, Caen, France.
Rheumatology (Oxford). 2008 Mar;47(3):281-8. doi: 10.1093/rheumatology/kem323. Epub 2008 Jan 31.
To investigate the mechanisms by which cytokines and 17beta-oestradiol (17beta-E2) modulate gene expression and activity of uridine diphosphoglucose dehydrogenase (UGDH), a key enzyme of GAG synthesis in articular chondrocytes.
Rabbit articular chondrocytes (RAC) from 3-week-old animals were incubated for 24 h with TGF-beta, insulin like growth factor-I (IGF-I), IL-1beta, IL-6 and 17beta-E2. GAG synthesis was measured by [35S]-sulphate labelling and the expression of the UGDH gene was estimated by both real-time polymerase chain reaction and western blotting, whereas the enzyme activity was assayed by a spectrophotometric procedure. In addition, the transcriptional activity of several UGDH gene promoter constructs was determined in RAC transiently transfected with wild-type or deleted human oestrogen receptor-alpha gene (hER alpha66 or hER alpha46, respectively).
17Beta-E2 and its receptor hER alpha66 enhanced GAG neosynthesis in rabbit articular chondrocytes, as did TGF-beta1 whereas IL-1beta decreased this synthesis. 17Beta-E2 was found to exert positive regulatory effects at mRNA, protein and UGDH activity levels. In addition, the receptor hER alpha66, but not hER alpha46, increased the transcriptional activity of the UGDH gene. In contrast, no clear correlation between transcription, translation and activity of the UGDH was found under the effects of the cytokines studied. However, TGF-beta enhanced the enzyme activity, whereas IL-1beta, IL-6 and IGF-I were without significant effect.
17Beta-E2 enhanced GAG synthesis in chondrocytes via up-regulation of the UGDH gene expression and enzyme activity. These data provide insights into the molecular mechanisms involved in the regulation of the UGDH gene and offer new approaches to investigate its potential alteration in joint diseases.
研究细胞因子和17β-雌二醇（17β-E2）调节关节软骨细胞中糖胺聚糖（GAG）合成关键酶尿苷二磷酸葡萄糖脱氢酶（UGDH）基因表达及活性的机制。
将3周龄动物的兔关节软骨细胞（RAC）分别与转化生长因子-β（TGF-β）、胰岛素样生长因子-I（IGF-I）、白细胞介素-1β（IL-1β）、白细胞介素-6（IL-6）和17β-E2孵育24小时。通过[35S]-硫酸盐标记法检测GAG合成，采用实时聚合酶链反应和蛋白质印迹法评估UGDH基因的表达，并用分光光度法测定酶活性。此外，在分别瞬时转染野生型或缺失型人雌激素受体-α基因（分别为hERα66或hERα46）的RAC中，测定几种UGDH基因启动子构建体的转录活性。
17β-E2及其受体hERα66与TGF-β1一样，可增强兔关节软骨细胞中的GAG新合成，而IL-1β则降低这种合成。发现17β-E2在mRNA、蛋白质和UGDH活性水平上发挥正调控作用。此外，受体hERα66而非hERα46可增加UGDH基因的转录活性。相比之下，在所研究的细胞因子作用下，未发现UGDH转录、翻译和活性之间存在明显相关性。然而，TGF-β可增强酶活性，而IL-1β、IL-6和IGF-I则无显著影响。
17β-E2通过上调UGDH基因表达和酶活性增强软骨细胞中的GAG合成。这些数据为UGDH基因调控的分子机制提供了见解，并为研究其在关节疾病中的潜在改变提供了新方法。
Zotero 插件