Guangzhou Institute of Traumatic Surgery, Guangzhou Red Cross Hospital, Jinan University, Guangzhou, Guangdong 510220, China.
Department of Orthopaedics, Guangzhou Red Cross Hospital, Jinan University, Guangzhou, Guangdong 510220, China.
Biosci Rep. 2020 Nov 27;40(11). doi: 10.1042/BSR20203107.
Articular cartilage injury or defect is a common disease and is mainly characterized by cartilage degradation because of chondrocyte inflammation. By now, there are no effective drugs and methods to protect articular cartilage from degradation. Icariin (ICA) is a typical flavonoid compound extracted from Epimedii Folium with anti-inflammatory and bone-protective effects. Our previous studies demonstrate that ICA up-regulates HIF-1α expression and glycolysis in chondrocytes and maintains chondrocyte phenotype. As another member of HIFs family, HIF-2α always plays a key role in inflammation. The effect of ICA on HIF-2α is unclear by now. In the present study, we confirmed the findings in our previous study that ICA promoted not only chondrocyte vitality and extracellular matrix (ECM) synthesis, but also the anti-inflammatory effect of ICA. In bone defect mice, ICA inhibited the expressions of NF-κB and HIF-2α. In TNF-α-treated ADTC5 chondrocytes, ICA neutralized the activation of IKK (IKK phosphorylation), the phosphorylation of IkB and NF-κB and the expression of HIF-2α. Furthermore, ICA inhibited the nucleus transfer of NF-κB and the expressions of MMP9 and ADAMTS5, two key targets of NF-κB/HIF-2α signal pathway. Taken together, the present study demonstrated that ICA may increase the vitality of chondrocytes by suppressing the inflammatory injury through the inhibition on NF-κB/HIF-2α signaling pathway. ICA is one effective candidate drug for the treatment of articular cartilage injury.
关节软骨损伤或缺陷是一种常见疾病,主要特征是软骨降解,因为软骨细胞炎症。到目前为止,还没有有效的药物和方法来保护关节软骨免受降解。淫羊藿苷(ICA)是从淫羊藿中提取的一种典型的黄酮类化合物,具有抗炎和护骨作用。我们之前的研究表明,ICA 上调软骨细胞中的 HIF-1α 表达和糖酵解作用,并维持软骨细胞表型。作为 HIFs 家族的另一个成员,HIF-2α 通常在炎症中起关键作用。到目前为止,ICA 对 HIF-2α 的影响还不清楚。在本研究中,我们证实了之前研究中的发现,即 ICA 不仅促进了软骨细胞活力和细胞外基质(ECM)合成,而且还发挥了 ICA 的抗炎作用。在骨缺损小鼠中,ICA 抑制了 NF-κB 和 HIF-2α 的表达。在 TNF-α 处理的 ADTC5 软骨细胞中,ICA 中和了 IKK(IKK 磷酸化)的激活、IkB 和 NF-κB 的磷酸化以及 HIF-2α 的表达。此外,ICA 抑制了 NF-κB 和 MMP9 和 ADAMTS5 的核转移,NF-κB/HIF-2α 信号通路的两个关键靶标。总之,本研究表明,ICA 可能通过抑制 NF-κB/HIF-2α 信号通路抑制炎症损伤来增加软骨细胞的活力。ICA 是治疗关节软骨损伤的一种有效候选药物。