Department of Biological Sciences, College of Natural Sciences, Kongju National University, Daehakro 56, Gongju, 32588, South Korea.
Eur J Pharmacol. 2019 Nov 15;863:172672. doi: 10.1016/j.ejphar.2019.172672. Epub 2019 Sep 19.
Simvastatin is widely used as a specific inhibitor of 3-hydroxy-3-methyl-glutaryl-CoA reductase to reduce the levels of low-density lipoprotein cholesterol. However, its regulatory mechanism in chondrocyte differentiation is unclear. This study was conducted to evaluate the effects and signalling pathway of simvastatin on chondrocyte differentiation. We found that simvastatin induced chondrocyte differentiation, as confirmed by increased type II collagen expression and induced sulphated proteoglycan synthesis. Western blotting results showed that expression of type II collagen increased 6-fold in a dose-dependent manner compared with that in the control. Further, nuclear/cytosol fraction analysis revealed that simvastatin reduced the expression and translocation of β-catenin into the nucleus from the cytoplasm by approximately 50% compared with that in the control. A luciferase assay using a T cell factor/lymphoid enhancer factor reporter construct was performed to test the transcriptional activity of β-catenin. Simvastatin-induced differentiation was dependent on inactivation of β-catenin, as simvastatin inhibited accumulation of β-catenin, which was characterized by translocation of β-catenin to the nucleus as shown by immunofluorescence staining and the luciferase assay. Prevention of β-catenin degradation by inhibition of the proteasome with z-Leu-Leu-Leu-CHO blocked the increase in type II collagen expression. Simvastatin treatment reduced chondrocyte dedifferentiation induced by retinoic acid or serial monolayer culturing by 50% compared to that in the non-treated cells. Our findings demonstrate that simvastatin increases differentiation of rabbit articular chondrocytes via the β-catenin pathway.
辛伐他汀被广泛用作 3-羟基-3-甲基戊二酰辅酶 A 还原酶的特异性抑制剂，以降低低密度脂蛋白胆固醇水平。然而，其在软骨细胞分化中的调节机制尚不清楚。本研究旨在评估辛伐他汀对软骨细胞分化的影响及其信号通路。我们发现辛伐他汀诱导软骨细胞分化，这一点通过增加 II 型胶原表达和诱导硫酸蛋白聚糖合成得到证实。Western blot 结果显示，与对照组相比，辛伐他汀以剂量依赖的方式使 II 型胶原的表达增加了 6 倍。此外，核/胞浆分馏分析表明，与对照组相比，辛伐他汀使β-连环蛋白的表达和从细胞质向细胞核的易位减少了约 50%。使用 T 细胞因子/淋巴增强因子报告基因构建体进行了荧光素酶测定，以测试β-连环蛋白的转录活性。辛伐他汀诱导的分化依赖于β-连环蛋白的失活，因为辛伐他汀抑制β-连环蛋白的积累，这表现为β-连环蛋白向细胞核易位，如免疫荧光染色和荧光素酶测定所示。通过用 Z-Leu-Leu-Leu-CHO 抑制蛋白酶体来阻止β-连环蛋白降解，阻止了 II 型胶原表达的增加。与未经处理的细胞相比，辛伐他汀处理可将维甲酸或连续单层培养诱导的软骨细胞去分化减少 50%。我们的研究结果表明，辛伐他汀通过β-连环蛋白通路增加兔关节软骨细胞的分化。
