Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.
Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal.
J Cell Physiol. 2020 Nov;235(11):8486-8494. doi: 10.1002/jcp.29691. Epub 2020 Apr 23.
Estrogen hormones are important for cartilage homeostasis, but nothing is known regarding the expression and role of the membrane G protein-coupled estrogen receptor (GPER), G protein-coupled receptor 30 (GPR30), in adult articular chondrocytes. Using immunohistochemistry of cartilage sections, quantitative real-time polymerase chain reaction and Western blot of chondrocyte extracts, we found that these cells express GPR30. Nonetheless, the pattern of bands detected by two distinct antibodies does not overlap, suggesting that the proteins detected represent partially degraded forms of the receptor. Treatment with GPR30 agonists did not induce Akt or ERK1/2 phosphorylation, two known GPR30-activated signaling pathways, suggesting that GPR30 is not functional in human chondrocytes. Therefore, the protective anti-osteoarthritic role of estrogen hormones in cartilage homeostasis is likely independent of GPR30. This study was performed using human cartilage collected from the distal femoral condyles of multiorgan donors at the Bone and Tissue Bank of the University and Hospital Center of Coimbra.
雌激素对软骨稳态很重要，但目前尚不清楚膜 G 蛋白偶联雌激素受体 (GPER)、G 蛋白偶联受体 30(GPR30) 在成年关节软骨细胞中的表达和作用。通过对软骨切片的免疫组织化学、软骨细胞提取物的实时定量聚合酶链反应和 Western blot 分析，我们发现这些细胞表达 GPR30。然而，两种不同抗体检测到的条带模式并不重叠，表明检测到的蛋白代表受体的部分降解形式。GPR30 激动剂处理并未诱导 Akt 或 ERK1/2 磷酸化，这是两种已知的 GPR30 激活的信号通路，表明 GPR30 在人软骨细胞中不起作用。因此，雌激素对软骨稳态的抗骨关节炎保护作用可能与 GPR30 无关。这项研究使用了来自科英布拉大学和医院中心骨与组织库的多器官供体远端股骨髁的人软骨进行。
