Up-regulation of type II collagen gene by 17β-estradiol in articular chondrocytes involves Sp1/3, Sox-9, and estrogen receptor α
Up-regulation of type II collagen gene by 17β-estradiol in articular chondrocytes involves Sp1/3, Sox-9, and estrogen receptor α
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DOI：
10.1007/s00109-014-1195-5
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发表时间：
2014-11-01
影响因子：
4.7
通讯作者：
Galera, Philippe
中科院分区：
文献类型：
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作者：
Maneix, Laure;Servent, Aurelie;Galera, Philippe
绝经后女性雌激素缺乏与骨关节炎 (OA) 之间存在联系，表明 17 β-雌二醇 (17 β-E-2) 可能是软骨稳态的调节剂。在这里，我们证明 17 beta-E-2 通过其受体人雌激素受体 α 66 (hER α 66) 刺激分化和去分化（反映 OA 表型）关节软骨细胞中 II 型胶原蛋白的表达。 hER α 66 的配体依赖性反式激活结构域 (AF-1) 对 II 型胶原基因 (COL2A1) 的反式激活是由 -266/-63-bp 启动子的“GC”结合位点介导的，通过 ER α、Sp1/Sp3、Sox9 和 p300 之间的物理相互作用，如染色质免疫沉淀 (ChIP) 和再染色质免疫沉淀 (Re-ChIP) 中所示原代细胞和去分化细胞的测定。 17 beta-E-2 和 hER α 66 增加了 Sp1/Sp3 和 Sox-9 对 COL2A1 启动子和增强子区域的 DNA 结合活性。此外，Sp1、Sp3 和 Sox-9 小干扰 RNA (siRNA) 阻止 hER α 66 诱导的 COL2A1 反式激活，表明这些因子及其各自的顺式区域是 hER α 66 介导的 COL2A1 上调所必需的。我们的结果强调了 17 beta-E-2 和 hER α 66 调节 Sp1/Sp3 异聚体结合活性并同时参与分别参与软骨细胞分化状态和 COL2A1 转录激活的必需因子 Sox-9 和 p300 的招募的基因组途径。因此，这些新发现对于 OA 软骨组织工程来说可能很有吸引力，因为 17 beta-E-2 可以促进软骨细胞再分化。
The existence of a link between estrogen deprivation and osteoarthritis (OA) in postmenopausal women suggests that 17 beta-estradiol (17 beta-E-2) may be a modulator of cartilage homeostasis. Here, we demonstrate that 17 beta-E-2 stimulates, via its receptor human estrogen receptor alpha 66 (hER alpha 66), type II collagen expression in differentiated and dedifferentiated (reflecting the OA phenotype) articular chondrocytes. Transactivation of type II collagen gene (COL2A1) by ligand-independent transactivation domain (AF-1) of hER alpha 66 was mediated by "GC" binding sites of the -266/-63-bp promoter, through physical interactions between ER alpha, Sp1/Sp3, Sox9, and p300, as demonstrated in chromatin immunoprecipitation (ChIP) and Re-Chromatin Immuno-Precipitation (Re-ChIP) assays in primary and dedifferentiated cells. 17 beta-E-2 and hER alpha 66 increased the DNA-binding activities of Sp1/Sp3 and Sox-9 to both COL2A1 promoter and enhancer regions. Besides, Sp1, Sp3, and Sox-9 small interfering RNAs (siRNAs) prevented hER alpha 66-induced transactivation of COL2A1, suggesting that these factors and their respective cis-regions are required for hER alpha 66-mediated COL2A1 up-regulation. Our results highlight the genomic pathway by which 17 beta-E-2 and hER alpha 66 modulate Sp1/Sp3 heteromer binding activity and simultaneously participate in the recruitment of the essential factors Sox-9 and p300 involved respectively in the chondrocyte-differentiated status and COL2A1 transcriptional activation. These novel findings could therefore be attractive for tissue engineering of cartilage in OA, by the fact that 17 beta-E-2 could promote chondrocyte redifferentiation.